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Sample records for chlorobium tepidum comparison

  1. The complete genome sequence of Chlorobium tepidum TLS, a photosynthetic, anaerobic, green-sulfur bacterium

    PubMed Central

    Eisen, Jonathan A.; Nelson, Karen E.; Paulsen, Ian T.; Heidelberg, John F.; Wu, Martin; Dodson, Robert J.; Deboy, Robert; Gwinn, Michelle L.; Nelson, William C.; Haft, Daniel H.; Hickey, Erin K.; Peterson, Jeremy D.; Durkin, A. Scott; Kolonay, James L.; Yang, Fan; Holt, Ingeborg; Umayam, Lowell A.; Mason, Tanya; Brenner, Michael; Shea, Terrance P.; Parksey, Debbie; Nierman, William C.; Feldblyum, Tamara V.; Hansen, Cheryl L.; Craven, M. Brook; Radune, Diana; Vamathevan, Jessica; Khouri, Hoda; White, Owen; Gruber, Tanja M.; Ketchum, Karen A.; Venter, J. Craig; Tettelin, Hervé; Bryant, Donald A.; Fraser, Claire M.

    2002-01-01

    The complete genome of the green-sulfur eubacterium Chlorobium tepidum TLS was determined to be a single circular chromosome of 2,154,946 bp. This represents the first genome sequence from the phylum Chlorobia, whose members perform anoxygenic photosynthesis by the reductive tricarboxylic acid cycle. Genome comparisons have identified genes in C. tepidum that are highly conserved among photosynthetic species. Many of these have no assigned function and may play novel roles in photosynthesis or photobiology. Phylogenomic analysis reveals likely duplications of genes involved in biosynthetic pathways for photosynthesis and the metabolism of sulfur and nitrogen as well as strong similarities between metabolic processes in C. tepidum and many Archaeal species. PMID:12093901

  2. Malate dehydrogenase from the mesophile Chlorobium vibrioforme and from the mild thermophile Chlorobium tepidum: molecular cloning, construction of a hybrid, and expression in Escherichia coli.

    PubMed

    Naterstad, K; Lauvrak, V; Sirevåg, R

    1996-12-01

    The genes (mdh) encoding malate dehydrogenase (MDH) from the mesophile Chlorobium vibrioforme and the moderate thermophile C. tepidum were cloned and sequenced, and the complete amino acid sequences were deduced. When the region upstream of mdh was analyzed, a sequence with high homology to an operon encoding ribosomal proteins from Escherichia coli was found. Each mdh gene consists of a 930-bp open reading frame and encodes 310 amino acid residues, corresponding to a subunit weight of 33,200 Da for the dimeric enzyme. The amino acid sequence identity of the two MDHs is 86%. Homology searches using the primary structures of the two MDHs revealed significant sequence similarity to lactate dehydrogenases. A hybrid mdh was constructed from the 3' part of mdh from C. tepidum and the 5' part of mdh from C. vibrioforme. The thermostabilities of the hybrid enzyme and of MDH from C. vibrioforme and C. tepidum were compared.

  3. Ultrafast energy transfer in light-harvesting chlorosomes from the green sulfur bacterium Chlorobium tepidum.

    PubMed

    Savikhin, S; van Noort, P I; Zhu, Y; Lin, S; Blankenship, R E; Struve, W S

    1995-05-15

    Two independent pump-probe techniques were used to study the antenna energy transfer kinetics of intact chlorosomes from the green sulfur bacterium Chlorobium tepidum with femtosecond resolution. The isotropic kinetics revealed by one-color experiments in the BChl c antenna were inhomogeneous with respect to wavelength. Multiexponential analyses of the photobleaching/stimulated emission (PB/SE) decay profiles typically yielded (apart from a approximately 10 fs component that may stem from the initial coherent oscillation) components with lifetimes 1-2 ps and several tens of ps. The largest amplitudes for the latter component occur at 810 nm, the longest wavelength studied. Analyses of most two-color pump-probe profiles with the probe wavelength red-shifted from the pump wavelength yielded no PB/SE rise components. PB/SE components with approximately 1 ps risetime were found in 790 --> 810 and 790 --> 820 nm profiles, in which the probe wavelength is situated well into the BChl a absorption region. A 760 --> 740 nm uphill two-color experiment yielded a PB/SE component with 4-6 ps risetime. Broadband absorption difference spectra of chlorosomes excited at 720 nm (in the blue edge of the 746 nm BChl c Qy band) exhibit approximately 15 nm red-shifting of the PB/SE peak wavelength during the first several hundred fs. Analogous spectra excited at 760 nm (at the red edge) show little dynamic spectral shifting. Our results suggest that inhomogeneous broadening and spectral equilibration play a larger role in the early BChl c antenna kinetics in chlorosomes from C. tepidum than in those from C. aurantiacus, a system studied previously. As in C. aurantiacus, the initial one-color anisotropies r(0) for most BChl c wavelengths are close to 0.4. The corresponding residual anisotropies r(infinity) are typically 0.19-0.25, which is much lower than found in C. aurantiacus (> or = 0.35); the transition moment organization is appreciably less collinear in the BChl c antenna of C

  4. Exciton dynamics in the chlorosomal antennae of the green bacteria Chloroflexus aurantiacus and Chlorobium tepidum.

    PubMed Central

    Prokhorenko, V I; Steensgaard, D B; Holzwarth, A R

    2000-01-01

    The energy transfer processes in isolated chlorosomes from green bacteria Chlorobium tepidum and Chloroflexus aurantiacus have been studied at low temperatures (1.27 K) by two-pulse photon echo and one-color transient absorption techniques with approximately 100 fs resolution. The decay of the coherence in both types of chlorosomes is characterized by four different dephasing times stretching from approximately 100 fs up to 300 ps. The fastest component reflects dephasing that is due to interaction of bacteriochlorophylls with the phonon bath, whereas the other components correspond to dephasing due to different energy transfer processes such as distribution of excitation along the rod-like aggregates, energy exchange between different rods in the chlorosome, and energy transfer to the base plate. As a basis for the interpretation of the excitation dephasing and energy transfer pathways, a superlattice-like structural model is proposed based on recent experimental data and computer modeling of the Bchl c aggregates (1994. Photosynth. Res. 41:225-233.) This model predicts a fine structure of the Q(y) absorption band that is fully supported by the present photon echo data. PMID:11023914

  5. Crystallization and preliminary X-ray studies of ferredoxin-NAD(P){sup +} reductase from Chlorobium tepidum

    SciTech Connect

    Muraki, Norifumi; Seo, Daisuke; Shiba, Tomoo; Sakurai, Takeshi; Kurisu, Genji

    2008-03-01

    Ferredoxin-NAD(P){sup +} reductase from C. tepidum has been overexpressed in E. coli, purified and crystallized. Diffraction data were collected to 2.4 Å resolution. Ferredoxin-NAD(P){sup +} reductase (FNR) is a key enzyme that catalyzes the photoreduction of NAD(P){sup +} to generate NAD(P)H during the final step of the photosynthetic electron-transport chain. FNR from the green sulfur bacterium Chlorobium tepidum is a homodimeric enzyme with a molecular weight of 90 kDa; it shares a high level of amino-acid sequence identity to thioredoxin reductase rather than to conventional plant-type FNRs. In order to understand the structural basis of the ferredoxin-dependency of this unique photosynthetic FNR, C. tepidum FNR has been heterologously expressed, purified and crystallized in two forms. Form I crystals belong to space group C222{sub 1} and contain one dimer in the asymmetric unit, while form II crystals belong to space group P4{sub 1}22 or P4{sub 3}22. Diffraction data were collected from a form I crystal to 2.4 Å resolution on the synchrotron-radiation beamline NW12 at the Photon Factory.

  6. Two exopolyphosphatases with distinct molecular architectures and substrate specificities from the thermophilic green-sulfur bacterium Chlorobium tepidum TLS.

    PubMed

    Albi, Tomás; Serrano, Aurelio

    2014-09-01

    The genome of the thermophilic green-sulfur bacterium Chlorobium tepidum TLS possesses two genes encoding putative exopolyphosphatases (PPX; EC 3.6.1.11), namely CT0099 (ppx1, 993 bp) and CT1713 (ppx2, 1557 bp). The predicted polypeptides of 330 and 518 aa residues are Ppx-GppA phosphatases of different domain architectures - the largest one has an extra C-terminal HD domain - which may represent ancient paralogues. Both ppx genes were cloned and overexpressed in Escherichia coli BL21(DE3). While CtPPX1 was validated as a monomeric enzyme, CtPPX2 was found to be a homodimer. Both PPX homologues were functional, K(+)-stimulated phosphohydrolases, with an absolute requirement for divalent metal cations and a marked preference for Mg(2+). Nevertheless, they exhibited remarkably different catalytic specificities with regard to substrate classes and chain lengths. Even though both enzymes were able to hydrolyse the medium-size polyphosphate (polyP) P13-18 (polyP mix with mean chain length of 13-18 phosphate residues), CtPPX1 clearly reached its highest catalytic efficiency with tripolyphosphate and showed substantial nucleoside triphosphatase (NTPase) activity, while CtPPX2 preferred long-chain polyPs (>300 Pi residues) and did not show any detectable NTPase activity. These catalytic features, taken together with the distinct domain architectures and molecular phylogenies, indicate that the two PPX homologues of Chl. tepidum belong to different Ppx-GppA phosphatase subfamilies that should play specific biochemical roles in nucleotide and polyP metabolisms. In addition, these results provide an example of the remarkable functional plasticity of the Ppx-GppA phosphatases, a family of proteins with relatively simple structures that are widely distributed in the microbial world.

  7. Spectroscopic and functional properties of novel 2[4Fe-4S] cluster-containing ferredoxins from the green sulfur bacterium Chlorobium tepidum.

    PubMed

    Yoon, K S; Bobst, C; Hemann, C F; Hille, R; Tabita, F R

    2001-11-23

    Two distinct ferredoxins, Fd I and Fd II, were isolated and purified to homogeneity from photoautotrophically grown Chlorobium tepidum, a moderately thermophilic green sulfur bacterium that assimilates carbon dioxide by the reductive tricarboxylic acid cycle. Both ferredoxins serve a crucial role as electron donors for reductive carboxylation, catalyzed by a key enzyme of this pathway, pyruvate synthase/pyruvate ferredoxin oxidoreductase. The reduction potentials of Fd I and Fd II were determined by cyclic voltammetry to be -514 and -584 mV, respectively, which are more electronegative than any previously studied Fds in which two [4Fe-4S] clusters display a single transition. Further spectroscopic studies indicated that the CD spectrum of oxidized Fd I closely resembled that of Fd II; however, both spectra appeared to be unique relative to ferredoxins studied previously. Double integration of the EPR signal of the two Fds yielded approximately approximately 2.0 spins per molecule, compatible with the idea that C. tepidum Fd I and Fd II accept 2 electrons upon reduction. These results suggest that the C. tepidum Fd I and Fd II polypeptides each contain two bound [4Fe-4S] clusters. C. tepidum Fd I and Fd II are novel 2[4Fe-4S] Fds, which were shown previously to function as biological electron donors or acceptors for C. tepidum pyruvate synthase/pyruvate ferredoxin oxidoreductase (Yoon, K.-S., Hille, R., Hemann, C. F., and Tabita, F. R. (1999) J. Biol. Chem. 274, 29772-29778). Kinetic measurements indicated that Fd I had approximately 2.3-fold higher affinity than Fd II. The results of amino acid sequence alignments, molecular modeling, oxidation-reduction potentials, and spectral properties strongly indicate that the C. tepidum Fds are chimeras of both clostridial-type and chromatium-type Fds, suggesting that the two Fds are likely intermediates in the evolutional development of 2[4Fe-4S] clusters compared with the well described clostridial and chromatium types.

  8. Parallel electron donation pathways to cytochrome c(z) in the type I homodimeric photosynthetic reaction center complex of Chlorobium tepidum.

    PubMed

    Tsukatani, Yusuke; Azai, Chihiro; Kondo, Toru; Itoh, Shigeru; Oh-Oka, Hirozo

    2008-09-01

    We studied the regulation mechanism of electron donations from menaquinol:cytochrome c oxidoreductase and cytochrome c-554 to the type I homodimeric photosynthetic reaction center complex of the green sulfur bacterium Chlorobium tepidum. We measured flash-induced absorption changes of multiple cytochromes in the membranes prepared from a mutant devoid of cytochrome c-554 or in the reconstituted membranes by exogenously adding cytochrome c-555 purified from Chlorobium limicola. The results indicated that the photo-oxidized cytochrome c(z) bound to the reaction center was rereduced rapidly by cytochrome c-555 as well as by the menaquinol:cytochrome c oxidoreductase and that cytochrome c-555 did not function as a shuttle-like electron carrier between the menaquinol:cytochrome c oxidoreductase and cytochrome c(z). It was also shown that the rereduction rate of cytochrome c(z) by cytochrome c-555 was as high as that by the menaquinol:cytochrome c oxidoreductase. The two electron-transfer pathways linked to sulfur metabolisms seem to function independently to donate electrons to the reaction center.

  9. A ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO)-like protein from Chlorobium tepidum that is involved with sulfur metabolism and the response to oxidative stress.

    PubMed

    Hanson, T E; Tabita, F R

    2001-04-10

    A gene encoding a product with substantial similarity to ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) was identified in the preliminary genome sequence of the green sulfur bacterium Chlorobium tepidum. A highly similar gene was subsequently isolated and sequenced from Chlorobium limicola f.sp. thiosulfatophilum strain Tassajara. Analysis of these amino acid sequences indicated that they lacked several conserved RubisCO active site residues. The Chlorobium RubisCO-like proteins are most closely related to deduced sequences in Bacillus subtilis and Archaeoglobus fulgidus, which also lack some typical RubisCO active site residues. When the C. tepidum gene encoding the RubisCO-like protein was disrupted, the resulting mutant strain displayed a pleiotropic phenotype with defects in photopigment content, photoautotrophic growth and carbon fixation rates, and sulfur metabolism. Most important, the mutant strain showed substantially enhanced accumulation of two oxidative stress proteins. These results indicated that the C. tepidum RubisCO-like protein might be involved in oxidative stress responses and/or sulfur metabolism. This protein might be an evolutional link to bona fide RubisCO and could serve as an important tool to analyze how the RubisCO active site developed.

  10. The crystal structure of ferritin from Chlorobium tepidum reveals a new conformation of the 4-fold channel for this protein family.

    PubMed

    Arenas-Salinas, Mauricio; Townsend, Philip D; Brito, Christian; Marquez, Valeria; Marabolli, Vanessa; Gonzalez-Nilo, Fernando; Matias, Cata; Watt, Richard K; López-Castro, Juan D; Domínguez-Vera, José; Pohl, Ehmke; Yévenes, Alejandro

    2014-11-01

    Ferritins are ubiquitous iron-storage proteins found in all kingdoms of life. They share a common architecture made of 24 subunits of five α-helices. The recombinant Chlorobium tepidum ferritin (rCtFtn) is a structurally interesting protein since sequence alignments with other ferritins show that this protein has a significantly extended C-terminus, which possesses 12 histidine residues as well as several aspartate and glutamic acid residues that are potential metal ion binding residues. We show that the macromolecular assembly of rCtFtn exhibits a cage-like hollow shell consisting of 24 monomers that are related by 4-3-2 symmetry; similar to the assembly of other ferritins. In all ferritins of known structure the short fifth α-helix adopts an acute angle with respect to the four-helix bundle. However, the crystal structure of the rCtFtn presented here shows that this helix adopts a new conformation defining a new assembly of the 4-fold channel of rCtFtn. This conformation allows the arrangement of the C-terminal region into the inner cavity of the protein shell. Furthermore, two Fe(III) ions were found in each ferroxidase center of rCtFtn, with an average FeA-FeB distance of 3 Å; corresponding to a diferric μ-oxo/hydroxo species. This is the first ferritin crystal structure with an isolated di-iron center in an iron-storage ferritin. The crystal structure of rCtFtn and the biochemical results presented here, suggests that rCtFtn presents similar biochemical properties reported for other members of this protein family albeit with distinct structural plasticity.

  11. Functional analysis of three sulfide:quinone oxidoreductase homologs in Chlorobaculum tepidum.

    PubMed

    Chan, Leong-Keat; Morgan-Kiss, Rachael M; Hanson, Thomas E

    2009-02-01

    Sulfide:quinone oxidoreductase (SQR) catalyzes sulfide oxidation during sulfide-dependent chemo- and phototrophic growth in bacteria. The green sulfur bacterium Chlorobaculum tepidum (formerly Chlorobium tepidum) can grow on sulfide as the sole electron donor and sulfur source. C. tepidum contains genes encoding three SQR homologs: CT0117, CT0876, and CT1087. This study examined which, if any, of the SQR homologs possess sulfide-dependent ubiquinone reduction activity and are required for growth on sulfide. In contrast to CT0117 and CT0876, transcripts of CT1087 were detected only when cells actively oxidized sulfide. Mutation of CT0117 or CT1087 in C. tepidum decreased SQR activity in membrane fractions, and the CT1087 mutant could not grow with >or=6 mM sulfide. Mutation of both CT0117 and CT1087 in C. tepidum completely abolished SQR activity, and the double mutant failed to grow with >or=4 mM sulfide. A C-terminal His(6)-tagged CT1087 protein was membrane localized, as was SQR activity. Epitope-tagged CT1087 was detected only when sulfide was actively consumed by cells. Recombinantly produced CT1087 and CT0117 proteins had SQR activity, while CT0876 did not. In summary, we conclude that, under the conditions tested, both CT0117 and CT1087 function as SQR proteins in C. tepidum. CT0876 may support the growth of C. tepidum at low sulfide concentrations, but no evidence was found for SQR activity associated with this protein.

  12. Sorption of metals by Chlorobium spp.

    PubMed

    Garcia-Gil, J; Borrego, C

    1997-12-01

    The capacity of two species of green phototrophic sulfur bacteria, Chlorobium limicola and C. phaeobacteroides, to sorb several metal ions (Mn2+, Fe2+, Ni2+, Cu2+, Zn2+, Cd2+ and Pb2+) has been tested in laboratory batch cultures at increasing concentrations up to 2,000 mumol/l. Except for nickel--which was not sorbed to bacterial cells--the rest of metals tested were bound in a fast and passive process, which was mathematically described by means of Freundlich isotherms models. The sorption capacity of the two species studied were found to be dependent on the metal involved, whereas no differences were observed in the sorption intensity, suggesting that in all cases the sorption process proceeds in a similar way. Further, the comparison of the sorption intensity values as well as the metal recovery index (Ri), for both species, revealed that C. phaeobacteroides was more efficient that C. limicola to attach metal ions. The ecological significance of this ability in the water column of some stratified lakes, where coinciding maxima of ferrous iron and green photosynthetic sulfur bacteria are frequently found, is discussed.

  13. Genetic Manipulation of Carotenoid Biosynthesis in the Green Sulfur Bacterium Chlorobium tepidum†

    PubMed Central

    Frigaard, Niels-Ulrik; Maresca, Julia A.; Yunker, Colleen E.; Jones, A. Daniel; Bryant, Donald A.

    2004-01-01

    The green sulfur bacterium Chlorobium tepidum is a strict anaerobe and an obligate photoautotroph. On the basis of sequence similarity with known enzymes or sequence motifs, nine open reading frames encoding putative enzymes of carotenoid biosynthesis were identified in the genome sequence of C. tepidum, and all nine genes were inactivated. Analysis of the carotenoid composition in the resulting mutants allowed the genes encoding the following six enzymes to be identified: phytoene synthase (crtB/CT1386), phytoene desaturase (crtP/CT0807), ζ-carotene desaturase (crtQ/CT1414), γ-carotene desaturase (crtU/CT0323), carotenoid 1′,2′-hydratase (crtC/CT0301), and carotenoid cis-trans isomerase (crtH/CT0649). Three mutants (CT0180, CT1357, and CT1416 mutants) did not exhibit a discernible phenotype. The carotenoid biosynthetic pathway in C. tepidum is similar to that in cyanobacteria and plants by converting phytoene into lycopene using two plant-like desaturases (CrtP and CrtQ) and a plant-like cis-trans isomerase (CrtH) and thus differs from the pathway known in all other bacteria. In contrast to the situation in cyanobacteria and plants, the construction of a crtB mutant completely lacking carotenoids demonstrates that carotenoids are not essential for photosynthetic growth of green sulfur bacteria. However, the bacteriochlorophyll a contents of mutants lacking colored carotenoids (crtB, crtP, and crtQ mutants) were decreased from that of the wild type, and these mutants exhibited a significant growth rate defect under all light intensities tested. Therefore, colored carotenoids may have both structural and photoprotection roles in green sulfur bacteria. The ability to manipulate the carotenoid composition so dramatically in C. tepidum offers excellent possibilities for studying the roles of carotenoids in the light-harvesting chlorosome antenna and iron-sulfur-type (photosystem I-like) reaction center. The phylogeny of carotenogenic enzymes in green sulfur

  14. High-pressure hole-burning studies of the bacteriochlorophyll a antenna complex from Chlorobium tepidum

    SciTech Connect

    Reddy, N.R.S.; Jankowiak, R.; Small, G.J. |

    1995-10-26

    The dependence of the low-temperature Q{sub y} absorption and nonphotochemical hole-burned spectra of the title complex (also known as the FMO complex) on pressure (<= 700 MPa) is reported. Pressure-induced structural changes of the complex were found to be elastic. The linear pressure shifts at 4.2 K for the principal absorption bands at 805, 814 and 825 nm are -0.08, -0.11, and -0.11 cm{sup -1}/MPa, respectively. Importantly, the 825 and 814 nm absorption profiles (shape, intensity) are independent of pressure. The results establish that, even at the highest values used, pressure has only a weak effect on the pairwise excitonic couplings of the bacteriochlorophyll (BChl) molecules, inhomogeneous broadening, and electron-phonon coupling. The pressure dependence of the Q{sub y} spectrum and zero-phonon holes (ZPH) burned in the 825 nm band can be rationalized in terms of dispersion interactions when BChl occupation numbers for the exciton levels are taken into account. These ZPH, which are assigned to the lowest level at 827 nm, carry a width of 0.6 cm{sup -1} at 4.2 K, which is independent of the pressure at which the hole is burned. This width is ascribed to dephasing, T{sub 2} = 35 ps. Possible mechanisms for the dephasing are considered, and its pressure independence is discussed. 80 refs., 12 figs., 1 tab.

  15. Draft Genome Sequence of the Pelagic Photoferrotroph Chlorobium phaeoferrooxidans

    PubMed Central

    Hahn, Aria S.; Morgan-Lang, Connor; Thompson, Katherine J.; Simister, Rachel L.; Llirós, Marc; Hirst, Martin; Hallam, Steven J.

    2017-01-01

    ABSTRACT Here, we report the draft genome sequence of Chlorobium phaeoferrooxidans, a photoferrotrophic member of the genus Chlorobium in the phylum Chlorobi. This genome sequence provides insight into the metabolic capacity that underpins photoferrotrophy within low-light-adapted pelagic Chlorobi. PMID:28360175

  16. Biological conversion of synthesis gas. [Chlorobium thiosulfatophilum, chlorobium phaeobacteroides, and Rhodospirillum rubrum

    SciTech Connect

    Not Available

    1992-01-06

    The anaerobic bacterium Rhodospirillum rubrum has been chosen for catalysis of the biological water gas shift reaction. Two bacteria, Chlorobium thiosulfatophilum and Chlorobium phaeobacteroides, are being evaluated as candidates for H{sub 2}S conversion to elemental sulfur. Since these latter two organisms both grow and convert H{sub 2}S in batch culture using standard basal medium, the choice of a suitable bacterium must be made in consideration of specific growth and uptake rates. Produced elemental sulfur stability against further oxidation to sulfate, and minimal use of H{sub 2} as a producing agent must also be considered. The effects of temperature on the performance of R. rubrum were evaluated. It was found that the cell concentration was highest at temperatures of 25 and 30{degree}C, and that the specific uptake rate was highest at temperatures of 30, 32 and 34{degree}C. No growth was observed at 37{degree}C. Also, temperature did not affect the yield of H{sub 2} from CO. Thus, R. rubrum may be used for biological rates gas shift at any temperature between 30 and 34{degree}C, although growth is maximized at lower temperatures. Preliminary studies with C. thiosulfatophilum showed rapid utilization of H{sub 2}S from the gas and liquid phases with subsequent production of elemental sulfur. Elemental sulfur production interfered with cell concentrations measurements, although a technique has been developed to rectify this problem.

  17. Conformational heterogeneity of the Roc domains in C. tepidum Roc–COR and implications for human LRRK2 Parkinson mutations

    PubMed Central

    Rudi, Katharina; Ho, Franz Y.; Gilsbach, Bernd K.; Pots, Henderikus; Wittinghofer, Alfred; Kortholt, Arjan; Klare, Johann P.

    2015-01-01

    Ras of complex proteins (Roc) is a Ras-like GTP-binding domain that always occurs in tandem with the C-terminal of Roc (COR) domain and is found in bacteria, plants and animals. Recently, it has been shown that Roco proteins belong to the family of G-proteins activated by nucleotide (nt)-dependent dimerization (GADs). We investigated the RocCOR tandem from the bacteria Chlorobium tepidum with site-directed spin labelling and pulse EPR distance measurements to follow conformational changes during the Roco G-protein cycle. Our results confirm that the COR domains are a stable dimerization device serving as a scaffold for the Roc domains that, in contrast, are structurally heterogeneous and dynamic entities. Contrary to other GAD proteins, we observed only minor structural alterations upon binding and hydrolysis of GTP, indicating significant mechanistic variations within this protein class. Mutations in the most prominent member of the Roco family of proteins, leucine-rich repeat (LRR) kinase 2 (LRRK2), are the most frequent cause of late-onset Parkinson's disease (PD). Using a stable recombinant LRRK2 Roc-COR-kinase fragment we obtained detailed kinetic data for the G-protein cycle. Our data confirmed that dimerization is essential for efficient GTP hydrolysis and PD mutations in the Roc domain result in decreased GTPase activity. Previous data have shown that these LRRK2 PD-mutations are located in the interface between Roc and COR. Importantly, analogous mutations in the conserved C. tepidum Roc/COR interface significantly influence the structure and nt-induced conformational changes of the Roc domains. PMID:26310572

  18. Characterization of ATP citrate lyase from Chlorobium limicola.

    PubMed Central

    Antranikian, G; Herzberg, C; Gottschalk, G

    1982-01-01

    ATP citrate lyase (EC 4.1.3.8) from Chlorobium limicola was partially purified. It was established that the consumption of substrates and the formation of products proceeded stoichiometrically and that citrate cleavage was of the si-type. ADP and oxaloacetate inhibited enzyme activity. Oxaloacetate also inhibited the growth of C. limicola. PMID:7142107

  19. Chlorobium ferrooxidans sp. nov., a phototrophic green sulfur bacterium that oxidizes ferrous iron in coculture with a "Geospirillum" sp. strain.

    PubMed

    Heising, S; Richter, L; Ludwig, W; Schink, B

    1999-08-01

    A green phototrophic bacterium was enriched with ferrous iron as sole electron donor and was isolated in defined coculture with a spirilloid chemoheterotrophic bacterium. The coculture oxidized ferrous iron to ferric iron with stoichiometric formation of cell mass from carbon dioxide. Sulfide, thiosulfate, or elemental sulfur was not used as electron donor in the light. Hydrogen or acetate in the presence of ferrous iron increased the cell yield of the phototrophic partner, and hydrogen could also be used as sole electron source. Complexed ferric iron was slowly reduced to ferrous iron in the dark, with hydrogen as electron source. Similar to Chlorobium limicola, the phototrophic bacterium contained bacteriochlorophyll c and chlorobactene as photosynthetic pigments, and also resembled representatives of this species morphologically. On the basis of 16S rRNA sequence comparisons, this organism clusters with Chlorobium, Prosthecochloris, and Pelodictyon species within the green sulfur bacteria phylum. Since the phototrophic partner in the coculture KoFox is only moderately related to the other members of the cluster, it is proposed as a new species, Chlorobium ferrooxidans. The chemoheterotrophic partner bacterium, strain KoFum, was isolated in pure culture with fumarate as sole substrate. The strain was identified as a member of the epsilon-subclass of the Proteobacteria closely related to "Geospirillum arsenophilum" on the basis of physiological properties and 16S rRNA sequence comparison. The "Geospirillum" strain was present in the coculture only in low numbers. It fermented fumarate, aspartate, malate, or pyruvate to acetate, succinate, and carbon dioxide, and could reduce nitrate to dinitrogen gas. It was not involved in ferrous iron oxidation but possibly provided a thus far unidentified growth factor to the phototrophic partner.

  20. Phylogenetic taxonomy of the family Chlorobiaceae on the basis of 16S rRNA and fmo (Fenna-Matthews-Olson protein) gene sequences.

    PubMed

    Imhoff, Johannes F

    2003-07-01

    A new taxonomy of the green sulfur bacteria is proposed, based on phylogenetic relationships determined using the sequences of the independent 16S rRNA and fmo (Fenna-Matthews-Olson protein) genes, and supported by the DNA G + C content and sequence signatures. Comparison of the traditional classification system for these bacteria with their phylogenetic relationship yielded a confusing picture, because properties used for classification (such as cell morphology, photosynthetic pigments and substrate utilization) do not concur with their phylogeny. Using the genetic information available, strains and species assigned to the genera Chlorobium, Pelodictyon and Prosthecochloris are considered, and the following changes are proposed. Pelodictyon luteolum is transferred to the genus Chlorobium as Chlorobium luteolum comb. nov. Pelodictyon clathratiforme and Pelodictyon phaeoclathratiforme are transferred to the genus Chlorobium and combined into one species, Chlorobium clathratiforme comb. nov. The name Pelodictyon will become a synonym of Chlorobium. Strains known as Chlorobium limicola subsp. thiosulfatophilum that have a low DNA G + C content (52-52.5 mol%) are treated as strains of Chlorobium limicola; those with a high DNA G + C content (58.1 mol%) are transferred to Chlorobaculum gen. nov., as Chlorobaculum thiosulfatiphilum sp. nov. Chlorobium tepidum is transferred to Chlorobaculum tepidum comb. nov., and defined as the type species of the genus Chlorobaculum. Strains assigned to Chlorobium phaeobacteroides, but phylogenetically distant from the type strain of this species, are assigned to Chlorobium limicola and to Chlorobaculum limnaeum sp. nov. Strains known as Chlorobium vibrioforme subsp. thiosulfatophilum are transferred to Chlorobaculum parvum sp. nov. Chlorobium chlorovibrioides is transferred to 'Chlorobaculum chlorovibrioides' comb. nov. The type strain of Chlorobium vibrioforme is phylogenetically related to Prosthecochloris, and is therefore

  1. Characterization of the quinones in purple sulfur bacterium Thermochromatium tepidum.

    PubMed

    Kimura, Yuuka; Kawakami, Tomoaki; Yu, Long-Jiang; Yoshimura, Miku; Kobayashi, Masayuki; Wang-Otomo, Zheng-Yu

    2015-07-08

    Quinone distributions in the thermophilic purple sulfur bacterium Thermochromatium tepidum have been investigated at different levels of the photosynthetic apparatus. Here we show that, on average, the intracytoplasmic membrane contains 18 ubiquinones (UQ) and 4 menaquinones (MQ) per reaction center (RC). About one-third of the quinones are retained in the light-harvesting-reaction center core complex (LH1-RC) with a similar ratio of UQ to MQ. The numbers of quinones essentially remains unchanged during crystallization of the LH1-RC. There are 1-2 UQ and 1 MQ associated with the RC-only complex in the purified solution sample. Our results suggest that a large proportion of the quinones are confined to the core complex and at least five UQs remain invisible in the current LH1-RC crystal structure.

  2. Temperature shift effect on the Chlorobaculum tepidum chlorosomes.

    PubMed

    Tang, Joseph Kuo-Hsiang; Xu, Ying; Muhlmann, Guillermo M; Zare, Farrokh; Khin, Yadana; Tam, Sun W

    2013-05-01

    Chlorobaculum [Cba.] tepidum is known to grow optimally at 48-52 °C and can also be cultured at ambient temperatures. In this paper, we prepared constant temperature, temperature shift, and temperature shift followed by backshift cultures and investigated the intrinsic properties and spectral features of chlorosomes from those cultures using various approaches, including temperature-dependent measurements on circular dichroism (CD), UV-visible, and dynamic light scattering. Our studies indicate that (1) chlorosomes from constant temperature cultures at 50 and 30 °C exhibited more resistance to heat relative to temperature shift cultures; (2) as temperature increases bacteriochlorophyll c (BChl c) in chlorosomes is prone to demetalation, which forms bacteriopheophytin c, and degradation under aerobic conditions. Some BChl c aggregates inside reduced chlorosomes prepared in low-oxygen environments can reform after heat treatments; (3) temperature shift cultures synthesize and incorporate more BChl c homologs with a smaller substituent at C-8 on the chlorin ring and less BChl c homologs with a larger long-chain alcohol at C-17(3) versus constant-temperature cultures. We hypothesize that the long-chain alcohol at C-17(3) (and perhaps together with the substituent at C-8) may account for thermal stability of chlorosomes and the substituent at C-8 may assist self-assembling BChls; and (4) while almost identical absorption spectra are detected, chlorosomes from different growth conditions exhibited differences in the rotational length of the CD signal, and aerobic and reduced chlorosomes also display different Qy CD intensities. Further, chlorosomes exhibited changes of CD features in response to temperature increases. Additionally, we compare temperature-dependent studies for the Cba. tepidum chlorosomes and previous studies for the Chloroflexus aurantiacus chlorosomes. Together, our work provides useful and novel insights on the properties and organization of

  3. Quantitative proteomics of Chlorobaculum tepidum: insights into the sulfur metabolism of a phototrophic green sulfur bacterium.

    PubMed

    Falkenby, Lasse G; Szymanska, Monika; Holkenbrink, Carina; Habicht, Kirsten S; Andersen, Jens S; Miller, Mette; Frigaard, Niels-Ulrik

    2011-10-01

    Chlorobaculum (Cba.) tepidum is a green sulfur bacterium that oxidizes sulfide, elemental sulfur, and thiosulfate for photosynthetic growth. To gain insight into the sulfur metabolism, the proteome of Cba. tepidum cells sampled under different growth conditions has been quantified using a rapid gel-free, filter-aided sample preparation (FASP) protocol with an in-solution isotopic labeling strategy. Among the 2245 proteins predicted from the Cba. tepidum genome, approximately 970 proteins were detected in unlabeled samples, whereas approximately 630-640 proteins were detected in labeled samples comparing two different growth conditions. Wild-type cells growing on thiosulfate had an increased abundance of periplasmic cytochrome c-555 and proteins of the periplasmic thiosulfate-oxidizing SOX enzyme system when compared with cells growing on sulfide. A dsrM mutant of Cba. tepidum, which lacks the dissimilatory sulfite reductase DsrM protein and therefore is unable to oxidize sulfur globules to sulfite, was also investigated. When compared with wild type, the dsrM cells exhibited an increased abundance of DSR enzymes involved in the initial steps of sulfur globule oxidation (DsrABCL) and a decreased abundance of enzymes putatively involved in sulfite oxidation (Sat-AprAB-QmoABC). The results show that Cba. tepidum regulates the cellular levels of enzymes involved in sulfur metabolism and other electron-transferring processes in response to the availability of reduced sulfur compounds.

  4. Final Report - "CO2 Sequestration in Cell Biomass of Chlorobium Thiosulfatophilum"

    SciTech Connect

    James L. Gaddy, PhD; Ching-Whan Ko, PhD

    2009-05-04

    World carbon dioxide emissions from the combustion of fossil fuels have increased at a rate of about 3 percent per year during the last 40 years to over 24 billion tons today. While a number of methods have been proposed and are under study for dealing with the carbon dioxide problem, all have advantages as well as disadvantages which limit their application. The anaerobic bacterium Chlorobium thiosulfatophilum uses hydrogen sulfide and carbon dioxide to produce elemental sulfur and cell biomass. The overall objective of this project is to develop a commercial process for the biological sequestration of carbon dioxide and simultaneous conversion of hydrogen sulfide to elemental sulfur. The Phase I study successfully demonstrated the technical feasibility of utilizing this bacterium for carbon dioxide sequestration and hydrogen sulfide conversion to elemental sulfur by utilizing the bacterium in continuous reactor studies. Phase II studies involved an advanced research and development to develop the engineering and scale-up parameters for commercialization of the technology. Tasks include culture isolation and optimization studies, further continuous reactor studies, light delivery systems, high pressure studies, process scale-up, a market analysis and economic projections. A number of anaerobic and aerobic microorgansims, both non-photosynthetic and photosynthetic, were examined to find those with the fastest rates for detailed study to continuous culture experiments. C. thiosulfatophilum was selected for study to anaerobically produce sulfur and Thiomicrospira crunogena waws selected for study to produce sulfate non-photosynthetically. Optimal conditions for growth, H2S and CO2 comparison, supplying light and separating sulfur were defined. The design and economic projections show that light supply for photosynthetic reactions is far too expensive, even when solar systems are considered. However, the aerobic non-photosynthetic reaction to produce sulfate with T

  5. Energy transfer between antenna complexes in the purple sulfur bacteria Chromatium tepidum and Chromatium vinosum

    NASA Astrophysics Data System (ADS)

    Kennis, John T. M.; Aartsma, Thijs J.; Amesz, Jan

    1995-05-01

    Energy transfer between antenna complexes was studied by means of time resolved absorption spectroscopy in the purple sulfur bacteria Chromatium tepidum and C. vinosum. The first species contains only one peripheral antenna complex, B800-B50, the other one has two, B800-850 and B800-820. Results obtained with chromatophores of C. tepidum indicated two time constants for energy transfer from B800-850 to the core complex, of 10 ps and a smaller one of 30 ps, suggesting non-uniform distances between the peripheral and core complexes. Similar results were obtained with C. vinosum, where time constants of 7 and 30 ps were found. Energy transfer from B800-820 to B800-850 was significantly faster. These results show that the rates of energy transfer from bacteriochlorophyll 850 to the core complex in the purple sulfur bacteria studied are quite similar to those found in purple non-sulfur bacteria. This may seem remarkable in view of the fact that the core antenna in C. tepidum absorbs at the unusually long wavelength of 918 nm, but a calculation indicates that the overlap integral for energy transfer to the core is not dramatically less than in C. vinosum.

  6. The ultrastructure of Chlorobaculum tepidum revealed by cryo-electron tomography.

    PubMed

    Kudryashev, Misha; Aktoudianaki, Aikaterini; Dedoglou, Dimitrios; Stahlberg, Henning; Tsiotis, Georgios

    2014-10-01

    Chlorobaculum (Cba) tepidum is a green sulfur bacterium that oxidizes sulfide, elemental sulfur, and thiosulfate for photosynthetic growth. As other anoxygenic green photosynthetic bacteria, Cba tepidum synthesizes bacteriochlorophylls for the assembly of a large light-harvesting antenna structure, the chlorosome. Chlorosomes are sac-like structures that are connected to the reaction centers in the cytoplasmic membrane through the BChl α-containing Fenna-Matthews-Olson protein. Most components of the photosynthetic machinery are known on a biophysical level, however, the structural integration of light harvesting with charge separation is still not fully understood. Despite over two decades of research, gaps in our understanding of cellular architecture exist. Here we present an in-depth analysis of the cellular architecture of the thermophilic photosynthetic green sulfur bacterium of Cba tepidum by cryo-electron tomography. We examined whole hydrated cells grown under different electron donor conditions. Our results reveal the distribution of chlorosomes in 3D in an unperturbed cell, connecting elements between chlorosomes and the cytoplasmic membrane and the distribution of reaction centers in the cytoplasmic membrane.

  7. Identification of a chondroitin synthase from an unexpected source, the green sulfur bacterium Chlorobium phaeobacteroides.

    PubMed

    Green, Dixy E; DeAngelis, Paul L

    2017-01-19

    Glycosaminoglycans [GAGs] are known to be present in all animals as well as some pathogenic microbes. Chondroitin sulfate is the most abundant GAG in mammals where it has various structural and adhesion roles. The Gram-negative bacteria Pasteurella multocida Type F and Escherichia coli K4 produce extracellular capsules composed of unsulfated chondroitin or a fructosylated chondroitin, respectively. Such polysaccharides that are structurally related to host molecules do not generally provoke a strong antibody response thus are thought to be employed as molecular camouflage during infection. We observed a sequence from the photosynthetic green sulfur bacteria, Chlorobium phaeobacteroides DSM 266, which was very similar (~62% identical) to the open reading frames of the known bi-functional chondroitin synthases (PmCS and KfoC); some segments are strikingly conserved amongst the three proteins. Recombinant E. coli-derived Chlorobium enzyme preparations were found to possess bona fide chondroitin synthase activity in vitro This new catalyst, CpCS, however, has a more promiscuous acceptor usage than the prototypical PmCS, which may be of utility in novel chimeric GAG syntheses. The finding of such a similar chondroitin synthase enzyme in C. phaeobacteroides is unexpected for several reasons including: (a) a free-living non-pathogenic organism should not "need" an animal self molecule for protection, (b) the Proteobacteria and the green sulfur bacterial lineages diverged ~2.5-3 billion years ago, and (c) the ecological niches of these bacteria are not thought to overlap substantially to facilitate horizontal gene transfer. CpCS provides insight into the structure/function relationship of this class of enzymes.

  8. Ab initio calculation of excitonic Hamiltonian of light-harvesting complex LH1 of Thermochromatium tepidum

    NASA Astrophysics Data System (ADS)

    Kozlov, Maxim I.; Poddubnyy, Vladimir V.; Glebov, Ilya O.; Belov, Aleksandr S.; Khokhlov, Daniil V.

    2016-02-01

    The electronic properties of light-harvesting complexes determine the efficiency of energy transfer in photosynthetic antennae. Ab initio calculations of the electronic properties of bacteriochlorophylls (composing the LH1 complex of the purple bacteria Thermochromatium tepidum) were performed. Based on these calculations, the excitonic Hamiltonian of a native cyclic complex and the Hamiltonians of open complexes with several removed bacteriochlorophylls were constructed. Absorption spectra calculated based on these Hamiltonians agree well with the experimental data. We found that the parameters of interaction between the neighboring bacteriochlorophylls are significantly larger than the empirical parameters suggested previously.

  9. In situ high-resolution structure of the baseplate antenna complex in Chlorobaculum tepidum

    PubMed Central

    Nielsen, Jakob Toudahl; Kulminskaya, Natalia V.; Bjerring, Morten; Linnanto, Juha M.; Rätsep, Margus; Pedersen, Marie Østergaard; Lambrev, Petar H.; Dorogi, Márta; Garab, Győző; Thomsen, Karen; Jegerschöld, Caroline; Frigaard, Niels-Ulrik; Lindahl, Martin; Nielsen, Niels Chr.

    2016-01-01

    Photosynthetic antenna systems enable organisms harvesting light and transfer the energy to the photosynthetic reaction centre, where the conversion to chemical energy takes place. One of the most complex antenna systems, the chlorosome, found in the photosynthetic green sulfur bacterium Chlorobaculum (Cba.) tepidum contains a baseplate, which is a scaffolding super-structure, formed by the protein CsmA and bacteriochlorophyll a. Here we present the first high-resolution structure of the CsmA baseplate using intact fully functional, light-harvesting organelles from Cba. tepidum, following a hybrid approach combining five complementary methods: solid-state NMR spectroscopy, cryo-electron microscopy, isotropic and anisotropic circular dichroism and linear dichroism. The structure calculation was facilitated through development of new software, GASyCS for efficient geometry optimization of highly symmetric oligomeric structures. We show that the baseplate is composed of rods of repeated dimers of the strongly amphipathic CsmA with pigments sandwiched within the dimer at the hydrophobic side of the helix. PMID:27534696

  10. In situ high-resolution structure of the baseplate antenna complex in Chlorobaculum tepidum

    NASA Astrophysics Data System (ADS)

    Nielsen, Jakob Toudahl; Kulminskaya, Natalia V.; Bjerring, Morten; Linnanto, Juha M.; Rätsep, Margus; Pedersen, Marie Østergaard; Lambrev, Petar H.; Dorogi, Márta; Garab, Győző; Thomsen, Karen; Jegerschöld, Caroline; Frigaard, Niels-Ulrik; Lindahl, Martin; Nielsen, Niels Chr.

    2016-08-01

    Photosynthetic antenna systems enable organisms harvesting light and transfer the energy to the photosynthetic reaction centre, where the conversion to chemical energy takes place. One of the most complex antenna systems, the chlorosome, found in the photosynthetic green sulfur bacterium Chlorobaculum (Cba.) tepidum contains a baseplate, which is a scaffolding super-structure, formed by the protein CsmA and bacteriochlorophyll a. Here we present the first high-resolution structure of the CsmA baseplate using intact fully functional, light-harvesting organelles from Cba. tepidum, following a hybrid approach combining five complementary methods: solid-state NMR spectroscopy, cryo-electron microscopy, isotropic and anisotropic circular dichroism and linear dichroism. The structure calculation was facilitated through development of new software, GASyCS for efficient geometry optimization of highly symmetric oligomeric structures. We show that the baseplate is composed of rods of repeated dimers of the strongly amphipathic CsmA with pigments sandwiched within the dimer at the hydrophobic side of the helix.

  11. Multiple antioxidant proteins protect Chlorobaculum tepidum against oxygen and reactive oxygen species.

    PubMed

    Li, Hui; Jubelirer, Sara; Garcia Costas, Amaya M; Frigaard, Niels-Ulrik; Bryant, Donald A

    2009-11-01

    The genome of the green sulfur bacterium Chlorobaculum (Cba.) tepidum, a strictly anaerobic photolithoautotroph, is predicted to encode more than ten genes whose products are potentially involved in protection from reactive oxygen species and an oxidative stress response. The encoded proteins include cytochrome bd quinol oxidase, NADH oxidase, rubredoxin oxygen oxidoreductase, several thiol peroxidases, alkyl hydroperoxide reductase, superoxide dismutase, methionine sulfoxide reductase, and rubrerythrin. To test the physiological functions of some of these proteins, ten genes were insertionally inactivated. Wild-type Cba. tepidum cells were very sensitive to oxygen in the light but were remarkably resistant to oxygen in the dark. When wild-type and mutant cells were subjected to air for various times under dark or light condition, significant decreases in viability were detected in most of the mutants relative to wild type. Treatments with hydrogen peroxide (H(2)O(2)), tert-butyl hydroperoxide (t-BOOH) and methyl viologen resulted in more severe effects in most of the mutants than in the wild type. The results demonstrated that these putative antioxidant proteins combine to form an effective defense against oxygen and reactive oxygen species. Reverse-transcriptase polymerase chain reaction studies showed that the genes with functions in oxidative stress protection were constitutively transcribed under anoxic growth conditions.

  12. Insights into the excitonic states of individual chlorosomes from Chlorobaculum tepidum.

    PubMed

    Jendrny, Marc; Aartsma, Thijs J; Köhler, Jürgen

    2014-05-06

    Green-sulfur bacteria have evolved a unique light-harvesting apparatus, the chlorosome, by which it is perfectly adapted to thrive photosynthetically under extremely low light conditions. We have used single-particle, optical spectroscopy to study the structure-function relationship of chlorosomes each of which incorporates hundreds of thousands of self-assembled bacteriochlorophyll (BChl) molecules. The electronically excited states of these molecular assemblies are described as Frenkel excitons whose photophysical properties depend crucially on the mutual arrangement of the pigments. The signature of these Frenkel excitons and its relation to the supramolecular organization of the chlorosome becomes accessible by optical spectroscopy. Because subtle spectral features get obscured by ensemble averaging, we have studied individual chlorosomes from wild-type Chlorobaculum tepidum by polarization-resolved fluorescence-excitation spectroscopy. This approach minimizes the inherent sample heterogeneity and allows us to reveal properties of the exciton states without ensemble averaging. The results are compared with predictions from computer simulations of various models of the supramolecular organization of the BChl monomers. We find that the photophysical properties of individual chlorosomes from wild-type Chlorobaculum tepidum are consistent with a (multiwall) helical arrangement of syn-anti stacked BChl molecules in cylinders and/or spirals of different size.

  13. Chlorobaculum tepidum TLS displays a complex transcriptional response to sulfide addition.

    PubMed

    Eddie, Brian J; Hanson, Thomas E

    2013-01-01

    Chlorobaculum tepidum is a green sulfur bacterium (GSB) that is a model system for phototrophic sulfur oxidation. Despite over 2 decades of research, conspicuous gaps exist in our understanding of its electron donor metabolism and regulation. RNA sequencing (RNA-seq) was used to provide a global picture of the C. tepidum transcriptome during growth on thiosulfate as the sole electron donor and at time points following the addition of sulfide to such a culture. Following sulfide addition, 121 to 150 protein-coding genes displayed significant changes in expression depending upon the time point. These changes included a rapid decrease in expression of thiosulfate and elemental sulfur oxidation genes. Genes and gene loci with increased expression included CT1087, encoding a sulfide:quinone oxidoreductase required for growth in high sulfide concentrations; a polysulfide reductase-like complex operon, psrABC (CT0496 to CT0494); and, surprisingly, a large cluster of genes involved in iron acquisition. Finally, two genes that are conserved as a cassette in anaerobic bacteria and archaea, CT1276 and CT1277, displayed a strong increase in expression. The CT1277 gene product contains a DNA-binding domain, suggesting a role for it in sulfide-dependent gene expression changes.

  14. Chlorobaculum tepidum regulates chlorosome structure and function in response to temperature and electron donor availability.

    PubMed

    Morgan-Kiss, Rachael M; Chan, Leong-Keat; Modla, Shannon; Weber, Timothy S; Warner, Mark; Czymmek, Kirk J; Hanson, Thomas E

    2009-01-01

    Green sulfur bacteria (GSB) rely on the chlorosome, a light-harvesting apparatus comprised almost entirely of self-organizing arrays of bacteriochlorophyll (BChl) molecules, to harvest light energy and pass it to the reaction center. In Chlorobaculum tepidum, over 97% of the total BChl is made up of a mixture of four BChl c homologs in the chlorosome that differ in the number and identity of alkyl side chains attached to the chlorin ring. C. tepidum has been reported to vary the distribution of BChl c homologs with growth light intensity, with the highest degree of BChl c alkylation observed under low-light conditions. Here, we provide evidence that this functional response at the level of the chlorosome can be induced not only by light intensity, but also by temperature and a mutation that prevents phototrophic thiosulfate oxidation. Furthermore, we show that in conjunction with these functional adjustments, the fraction of cellular volume occupied by chlorosomes was altered in response to environmental conditions that perturb the balance between energy absorbed by the light-harvesting apparatus and energy utilized by downstream metabolic reactions.

  15. Excitation Energy Transfer Dynamics and Excited-State Structure in Chlorosomes of Chlorobium phaeobacteroides

    PubMed Central

    Pšenčík, Jakub; Ma, Ying-Zhong; Arellano, Juan B.; Hála, Jan; Gillbro, Tomas

    2003-01-01

    The excited-state relaxation within bacteriochlorophyll (BChl) e and a in chlorosomes of Chlorobium phaeobacteroides has been studied by femtosecond transient absorption spectroscopy at room temperature. Singlet-singlet annihilation was observed to strongly influence both the isotropic and anisotropic decays. Pump intensities in the order of 1011 photons × pulse−1 × cm−2 were required to obtain annihilation-free conditions. The most important consequence of applied very low excitation doses is an observation of a subpicosecond process within the BChl e manifold (∼200–500 fs), manifesting itself as a rise in the red part of the Qy absorption band of the BChl e aggregates. The subsequent decay of the kinetics measured in the BChl e region and the corresponding rise in the baseplate BChl a is not single-exponential, and at least two components are necessary to fit the data, corresponding to several BChl e→BChl a transfer steps. Under annihilation-free conditions, the anisotropic kinetics show a generally slow decay within the BChl e band (10–20 ps) whereas it decays more rapidly in the BChl a region (∼1 ps). Analysis of the experimental data gives a detailed picture of the overall time evolution of the energy relaxation and energy transfer processes within the chlorosome. The results are interpreted within an exciton model based on the proposed structure. PMID:12547796

  16. Triplet excited state spectra and dynamics of carotenoids from the thermophilic purple photosynthetic bacterium Thermochromatium tepidum

    SciTech Connect

    Niedzwiedzki, Dariusz; Kobayashi, Masayuki; Blankenship, R. E.

    2011-01-13

    Light-harvesting complex 2 from the anoxygenic phototrophic purple bacterium Thermochromatium tepidum was purified and studied by steady-state absorption, fluorescence and flash photolysis spectroscopy. Steady-state absorption and fluorescence measurements show that carotenoids play a negligible role as supportive energy donors and transfer excitation to bacteriochlorophyll-a with low energy transfer efficiency of ~30%. HPLC analysis determined that the dominant carotenoids in the complex are rhodopin and spirilloxanthin. Carotenoid excited triplet state formation upon direct (carotenoid) or indirect (bacteriochlorophyll-a Q{sub x} band) excitation shows that carotenoid triplets are mostly localized on spirilloxanthin. In addition, no triplet excitation transfer between carotenoids was observed. Such specific carotenoid composition and spectroscopic results strongly suggest that this organism optimized carotenoid composition in the light-harvesting complex 2 in order to maximize photoprotective capabilities of carotenoids but subsequently drastically suppressed their supporting role in light-harvesting process.

  17. Glycolipid analyses of light-harvesting chlorosomes from envelope protein mutants of Chlorobaculum tepidum.

    PubMed

    Tsukatani, Yusuke; Mizoguchi, Tadashi; Thweatt, Jennifer; Tank, Marcus; Bryant, Donald A; Tamiaki, Hitoshi

    2016-06-01

    Chlorosomes are large and efficient light-harvesting organelles in green photosynthetic bacteria, and they characteristically contain large numbers of bacteriochlorophyll c, d, or e molecules. Self-aggregated bacteriochlorophyll pigments are surrounded by a monolayer envelope membrane comprised of glycolipids and Csm proteins. Here, we analyzed glycolipid compositions of chlorosomes from the green sulfur bacterium Chlorobaculum tepidum mutants lacking one, two, or three Csm proteins by HPLC equipped with an evaporative light-scattering detector. The ratio of monogalactosyldiacylglyceride (MGDG) to rhamnosylgalactosyldiacylglyceride (RGDG) was smaller in chlorosomes from mutants lacking two or three proteins in CsmC/D/H motif family than in chlorosomes from the wild-type, whereas chlorosomes lacking CsmIJ showed relatively less RGDG than MGDG. The results suggest that the CsmC, CsmD, CsmH, and other chlorosome proteins are involved in organizing MGDG and RGDG and thereby affect the size and shape of the chlorosome.

  18. A novel and mild isolation procedure of chlorosomes from the green sulfur bacterium Chlorobaculum tepidum.

    PubMed

    Tokita, Seiji; Shimada, Keizo; Watabe, Kazuyuki; Matsuura, Katsumi; Mimuro, Mamoru

    2011-09-01

    In this article, we developed a new and mild procedure for the isolation of chlorosomes from a green sulfur bacterium Chlorobaculum tepidum. In this procedure, Fenna-Matthews-Olson (FMO) protein was released by long cold treatment (6°C) of cells under the presence of a chaotrope (2 M NaSCN) and 0.6 M sucrose. Chlorosomes were released by an osmotic shock of the cold-treated cells after the formation of spheroplasts without mechanical disruption. Chlorosomes were finally purified by a sucrose step-wise density gradient centrifugation. We obtained two samples with different density (20 and 23% sucrose band, respectively) and compared them by SDS-PAGE, absorption spectroscopy at 80 K, fluorescence and CD spectroscopy at room temperature. Cells whose absorption maximum was longer than 750 nm yielded higher amount of the 20% sucrose fraction than those having an absorption maximum shorter than 750 nm.

  19. Mutational analysis of three bchH paralogs in (bacterio-)chlorophyll biosynthesis in Chlorobaculum tepidum.

    PubMed

    Gomez Maqueo Chew, Aline; Frigaard, Niels-Ulrik; Bryant, Donald A

    2009-07-01

    The first committed step in the biosynthesis of (bacterio-)chlorophyll is the insertion of Mg2+ into protoporphyrin IX by Mg-chelatase. In all known (B)Chl-synthesizing organisms, Mg-chelatase is encoded by three genes that are homologous to bchH, bchD, and bchI of Rhodobacter spp. The genomes of all sequenced strains of green sulfur bacteria (Chlorobi) encode multiple bchH paralogs, and in the genome of Chlorobaculum tepidum, there are three bchH paralogs, denoted CT1295 (bchT), CT1955 (bchS), and CT1957 (bchH). Cba. tepidum mutants lacking one or two of these paralogs were constructed and characterized. All of the mutants lacking only one of these BchH homologs, as well as bchS bchT and bchH bchT double mutants, which can only produce BchH or BchS, respectively, were viable. However, attempts to construct a bchH bchS double mutant, in which only BchT was functional, were consistently unsuccessful. This result suggested that BchT alone is unable to support the minimal (B)Chl synthesis requirements of cells required for viability. The pigment compositions of the various mutant strains varied significantly. The BChl c content of the bchS mutant was only approximately 10% of that of the wild type, and this mutant excreted large amounts of protoporphyrin IX into the growth medium. The observed differences in BChl c production of the mutant strains were consistent with the hypothesis that the three BchH homologs function in end product regulation and/or substrate channeling of intermediates in the BChl c biosynthetic pathway.

  20. Excitation dynamics of two spectral forms of the core complexes from photosynthetic bacterium Thermochromatium tepidum.

    PubMed

    Ma, Fei; Kimura, Yukihiro; Zhao, Xiao-Hui; Wu, Yi-Shi; Wang, Peng; Fu, Li-Min; Wang, Zheng-Yu; Zhang, Jian-Ping

    2008-10-01

    The intact core antenna-reaction center (LH1-RC) core complex of thermophilic photosynthetic bacterium Thermochromatium (Tch.) tepidum is peculiar in its long-wavelength LH1-Q(y) absorption (915 nm). We have attempted comparative studies on the excitation dynamics of bacteriochlorophyll (BChl) and carotenoid (Car) between the intact core complex and the EDTA-treated one with the Q(y) absorption at 889 nm. For both spectral forms, the overall Car-to-BChl excitation energy transfer efficiency is determined to be approximately 20%, which is considerably lower than the reported values, e.g., approximately 35%, for other photosynthetic purple bacteria containing the same kind of Car (spirilloxanthin). The RC trapping time constants are found to be 50 approximately 60 ps (170 approximately 200 ps) for RC in open (closed) state irrespective to the spectral forms and the wavelengths of Q(y) excitation. Despite the low-energy LH1-Q(y) absorption, the RC trapping time are comparable to those reported for other photosynthetic bacteria with normal LH1-Q(y) absorption at 880 nm. Selective excitation to Car results in distinct differences in the Q(y)-bleaching dynamics between the two different spectral forms. This, together with the Car band-shift signals in response to Q(y) excitation, reveals the presence of two major groups of BChls in the LH1 of Tch. tepidum with a spectral heterogeneity of approximately 240 cm(-1), as well as an alteration in BChl-Car geometry in the 889-nm preparation with respect to the native one.

  1. Purification and characterization of the thermostable ribulose-1,5-bisphosphate carboxylase/oxygenase from the thermophilic purple bacterium Chromatium tepidum.

    PubMed

    Heda, G D; Madigan, M T

    1989-09-15

    The Calvin cycle enzyme ribulose-bisphosphate carboxylase/oxygenase has been purified and characterized from the thermophilic and obligately anaerobic purple sulfur bacterium, Chromatium tepidum. The enzyme is an L8S8 carboxylase with a molecular mass near 550 kDa. No evidence for a second form of the enzyme lacking small subunits was obtained. C. tepidum ribulose-bisphosphate carboxylase/oxygenase was stable to heating to temperatures of 60 degrees C and could be readily purified in an active form at room temperature. Both carboxylase and oxygenase activities of this enzyme were Mg2+-dependent and carboxylase activity was sensitive to the effector 6-phosphogluconic acid. The Km for ribulose bisphosphate for the carboxylase activity of the C. tepidum enzyme was substantially higher than that observed in mesophilic Calvin cycle autotrophs. Amino acid composition and immunological analyses of C. tepidum and Chromatium vinosum ribulose-bisphosphate carboxylases showed the enzymes to be highly related despite significant differences in heat stability. It is hypothesized that thermal stability of C. tepidum ribulose-bisphosphate carboxylase/oxygenase is due to differences in primary structure affecting folding patterns in both the large and small subunits and is clearly not the result of any unique quaternary structure of the thermostable enzyme.

  2. Chlorobaculum tepidum Modulates Amino Acid Composition in Response to Energy Availability, as Revealed by a Systematic Exploration of the Energy Landscape of Phototrophic Sulfur Oxidation.

    PubMed

    Levy, Amalie T; Lee, Kelvin H; Hanson, Thomas E

    2016-11-01

    Microbial sulfur metabolism, particularly the formation and consumption of insoluble elemental sulfur (S(0)), is an important biogeochemical engine that has been harnessed for applications ranging from bioleaching and biomining to remediation of waste streams. Chlorobaculum tepidum, a low-light-adapted photoautolithotrophic sulfur-oxidizing bacterium, oxidizes multiple sulfur species and displays a preference for more reduced electron donors: sulfide > S(0) > thiosulfate. To understand this preference in the context of light energy availability, an "energy landscape" of phototrophic sulfur oxidation was constructed by varying electron donor identity, light flux, and culture duration. Biomass and cellular parameters of C. tepidum cultures grown across this landscape were analyzed. From these data, a correction factor for colorimetric protein assays was developed, enabling more accurate biomass measurements for C. tepidum, as well as other organisms. C. tepidum's bulk amino acid composition correlated with energy landscape parameters, including a tendency toward less energetically expensive amino acids under reduced light flux. This correlation, paired with an observation of increased cell size and storage carbon production under electron-rich growth conditions, suggests that C. tepidum has evolved to cope with changing energy availability by tuning its proteome for energetic efficiency and storing compounds for leaner times.

  3. /sup 34/S//sup 32/S fractionation in sulfur cycles catalyzed by anaerobic bacteria. [Chlorobium vibrioforme; Desulfovibrio vulgaris

    SciTech Connect

    Fry, B.; Gest, H.; Hayes, J.M.

    1988-01-01

    Stable isotopic distributions in the sulfur cycle were studied with pure and mixed cultures of the anaerobic bacteria, Chlorobium vibrioforme and Desulfovibrio vulgaris. D. vulgaris and C. vibrioforme can catalyze three reactions constituting a complete anaerobic sulfur cycle: reduction of sulfate to sulfide (D. vulgaris), oxidation of sulfide to elemental sulfur (C. vibrioforme), and oxidation of sulfur to sulfate (C. vibrioforme). In all experiments, the first and last reactions favored concentration of the light /sup 32/S isotope in products (isotopic fractionation factor ..sigma.. = -7.2 and -1.7 per thousand, respectively), whereas oxidation of sulfide favored concentration of the heavy /sup 34/S isotope in products (..sigma.. = +1.7 per thousand). Experimental results and model calculations suggest that elemental sulfur enriched in /sup 34/S versus sulfide may be a biogeochemical marker for the presence of sulfide-oxidizing bacteria in modern and ancient environments.

  4. Measurement of photosynthesis using PAM technology in a purple sulfur bacterium Thermochromatium tepidum (Chromatiaceae).

    PubMed

    Ritchie, Raymond J; Mekjinda, Nutsara

    2015-01-01

    We demonstrate that Blue-diode-based pulse amplitude modulation (PAM) technology can be used to measure the photosynthetic electron transport rate (ETR) of purple sulfur bacteria (Thermochromatium tepidum, Chromatiaceae). Previous studies showed that PAM technology could be used to estimate photosynthesis in purple nonsulfur bacteria and so PAM technology can be used to estimate photosynthesis of both kinds of purple photosynthetic bacteria. The absorptance of Thermochromatium films on glass fiber disks was measured and used to calculate actual ETR. ETR vs Irradiance (P vs E) curves fitted the waiting-in-line model (ETR = (ETRmax × E/Eopt) × exp (1−E/Eopt)). Yield (Y) was only ≈ 0.3–0.4. Thermochromatium saturates at 325 ± 13.8 μmol photons m(−2) s(−1) or ≈15% sunlight and shows photoinhibition at high irradiances. A pond of Thermochromatium would exhibit classic surface inhibition. Photosynthesis is extremely low in the absence of an electron source: ETR increases in the presence of acetate (5 mol m(−3)) provided as an organic carbon source and also increases in the presence of sulfite (3 mol m(−3)) but not sulfide and is only marginally increased by the presence of Fe(2+). Nonphotochemical quenching does occur in Thermochromatium but at very low levels compared to oxygenic photo-organisms or Rhodopseudomonads.

  5. On destabilization of the Fenna-Matthews-Olson complex of Chlorobaculum tepidum.

    PubMed

    Kell, Adam; Acharya, Khem; Blankenship, Robert E; Jankowiak, Ryszard

    2014-06-01

    The Fenna-Matthews-Olson (FMO) complex from the green sulfur bacterium Chlorobaculum tepidum was studied with respect to its stability. We provide a critical assessment of published and recently measured optical spectra. FMO complexes were found to destabilize over time producing spectral shifts, with destabilized samples having significantly higher hole-burning efficiencies; indicating a remodeled protein energy landscape. Observed correlated peak shifts near 825 and 815 nm suggest possible correlated (protein) fluctuations. It is proposed that the value of 35 cm(-1) widely used for reorganization energy (E λ ), which has important implications for the contributions to the coherence rate (Kreisbeck and Kramer 3:2828-2833, 2012), in various modeling studies of two-dimensional electronic spectra is overestimated. We demonstrate that the value of E λ is most likely about 15-22 cm(-1) and suggest that spectra reported in the literature (often measured on different FMO samples) exhibit varied peak positions due to different purification/isolation procedures or destabilization effects.

  6. Chlorobium limicola forma thiosulfatophilum: Biocatalyst in the Production of Sulfur and Organic Carbon from a Gas Stream Containing H2S and CO2

    PubMed Central

    Cork, Douglas J.; Garunas, Ruta; Sajjad, Ashfaq

    1983-01-01

    Chlorobium limicola forma thiosulfatophilum (ATCC 17092) was grown in a 1-liter continuously stirred tank reactor (800-ml liquid volume) at pH 6.8, 30°C, saturated light intensity, and a gas flow rate of 23.6 ml/min from a gas cylinder blend consisting of 3.9 mol% H2S, 9.2 mol% CO2, 86.4 mol% N2, and 0.5 mol% H2. This is the first demonstration of photoautotrophic growth of a Chlorobium sp. on a continuous inorganic gas feed. A significant potential exists for applying this photoautotrophic process to desulfurization and CO2 fixation of gases containing acidic components (H2S and CO2). PMID:16346255

  7. ATR-FTIR detection of metal-sensitive structural changes in the light-harvesting 1 reaction center complex from the thermophilic purple sulfur bacterium Thermochromatium tepidum.

    PubMed

    Li, Yong; Kimura, Yukihiro; Arikawa, Teruhisa; Wang-Otomo, Zheng-Yu; Ohno, Takashi

    2013-12-17

    Thermochromatium tepidum grows at the highest temperature among purple bacteria, and the light-harvesting 1 reaction center (LH1-RC) complex enhances the thermal stability by utilizing Ca(2+), although the molecular mechanism has yet to be resolved. Here, we applied perfusion-induced attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy to highly purified LH1-RC complexes from Tch. tepidum and detected for the first time metal-sensitive fine structural changes involved in the enhanced thermal stability of this complex. The Tch. tepidum LH1-RC complex exhibited Sr(2+)/Ca(2+) ATR-FTIR difference bands that reflect changes in the polypeptide backbones and amino acid residues upon the replacement of native Ca(2+) with Sr(2+). The difference bands also appeared in the following Ca(2+)/Sr(2+) difference spectra with almost identical intensities but inverse signs, demonstrating that the structural changes induced by the metal exchange are fully reversible. In contrast, these ATR-FTIR signals were faintly detected in the mesophilic counterpart Allochromatium vinosum . A comparative analysis using LH1 complexes lacking the RCs strongly indicated that the metal-sensitive bands originate from polypeptide backbones and amino acid residues near the putative Ca(2+)-binding site at the C-terminal region of the Tch. tepidum LH1 complexes. Structural changes induced by Sr(2+) and Ba(2+) substitutions were essentially identical. However, Cd(2+) substitution exhibited unique structural modifications, which may be responsible for the severely deteriorated thermal stability of Cd(2+)-substituted complexes. Possible assignments for the present ATR-FTIR signals and their relation with the molecular mechanism of enhancing the thermal stability of Tch. tepidum LH1-RC proteins are discussed on the basis of the recent structural information on the Ca(2+)-binding site.

  8. In Vitro Enzymatic Activities of Bacteriochlorophyll a Synthase Derived from the Green Sulfur Photosynthetic Bacterium Chlorobaculum tepidum.

    PubMed

    Saga, Yoshitaka; Hirota, Keiya; Harada, Jiro; Tamiaki, Hitoshi

    2015-08-18

    The activity of an enzyme encoded by the CT1610 gene in the green sulfur photosynthetic bacterium Chlorobaculum tepidum, which was annotated as bacteriochlorophyll (BChl) a synthase, BchG (denoted as tepBchG), was examined in vitro using the lysates of Escherichia coli containing the heterologously expressed enzyme. BChl a possessing a geranylgeranyl group at the 17-propionate residue (BChl aGG) was produced from bacteriochlorophyllide (BChlide) a and geranylgeranyl pyrophosphate in the presence of tepBchG. Surprisingly, tepBchG catalyzed the formation of BChl a bearing a farnesyl group (BChl aF) as in the enzymatic production of BChl aGG, indicating loose recognition of isoprenoid pyrophosphates in tepBchG. In contrast to such loose recognition of isoprenoid substrates, BChlide c and chlorophyllide a gave no esterifying product upon being incubated with geranylgeranyl or farnesyl pyrophosphate in the presence of tepBchG. These results confirm that tepBchG undoubtedly acts as the BChl a synthase in Cba. tepidum. The enzymatic activity of tepBchG was higher than that of BchG of Rhodobacter sphaeroides at 45 °C, although the former activity was lower than the latter below 35 °C.

  9. Structural analysis of the homodimeric reaction center complex from the photosynthetic green sulfur bacterium Chlorobaculum tepidum.

    PubMed

    He, Guannan; Zhang, Hao; King, Jeremy D; Blankenship, Robert E

    2014-08-05

    The reaction center (RC) complex of the green sulfur bacterium Chlorobaculum tepidum is composed of the Fenna-Matthews-Olson antenna protein (FMO) and the reaction center core (RCC) complex. The RCC complex has four subunits: PscA, PscB, PscC, and PscD. We studied the FMO/RCC complex by chemically cross-linking the purified sample followed by biochemical and spectroscopic analysis. Blue-native gels showed that there were two types of FMO/RCC complexes, which are consistent with complexes with one copy of FMO per RCC and two copies of FMO per RCC. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the samples after cross-linking showed that all five subunits of the RC can be linked by three different cross-linkers: bissulfosuccinimidyl suberate, disuccinimidyl suberate, and 3,3-dithiobis-sulfosuccinimidyl propionate. The interaction sites of the cross-linked complex were also studied using liquid chromatography coupled to tandem mass spectrometry. The results indicated that FMO, PscB, PscD, and part of PscA are exposed on the cytoplasmic side of the membrane. PscD helps stabilize FMO to the reaction center and may facilitate transfer of the electron from the RC to ferredoxin. The soluble domain of the heme-containing cytochrome subunit PscC and part of the core subunit PscA are located on the periplasmic side of the membrane. There is a close relationship between the periplasmic portions of PscA and PscC, which is needed for the efficient transfer of the electron between PscC and P840.

  10. Ultrafast time-resolved spectroscopy of the light-harvesting complex 2 (LH2) from the photosynthetic bacterium Thermochromatium tepidum

    SciTech Connect

    Niedzwiedzki, Dariusz M.; Fuciman, Marcel; Kobayashi, Masayuki; Frank, Harry A.; Blankenship, Robert E.

    2011-10-08

    The light-harvesting complex 2 from the thermophilic purple bacterium Thermochromatium tepidum was purified and studied by steady-state absorption and fluorescence, sub-nanosecond-time-resolved fluorescence and femtosecond time-resolved transient absorption spectroscopy. The measurements were performed at room temperature and at 10 K. The combination of both ultrafast and steady-state optical spectroscopy methods at ambient and cryogenic temperatures allowed the detailed study of carotenoid (Car)-to-bacteriochlorophyll (BChl) as well BChl-to-BChl excitation energy transfer in the complex. The studies show that the dominant Cars rhodopin (N = 11) and spirilloxanthin (N = 13) do not play a significant role as supportive energy donors for BChl a. This is related with their photophysical properties regulated by long π-electron conjugation. On the other hand, such properties favor some of the Cars, particularly spirilloxanthin (N = 13) to play the role of the direct quencher of the excited singlet state of BChl.

  11. Characterization of chlorophyll pigments in the mutant lacking 8-vinyl reductase of green photosynthetic bacterium Chlorobaculum tepidum.

    PubMed

    Mizoguchi, Tadashi; Harada, Jiro; Tamiaki, Hitoshi

    2012-12-01

    The mutant lacking the enzyme BciA (renamed CT1063), which catalyzed reduction of the 8-vinyl group of a porphyrinoid-type 3,8-divinyl-(proto)chlorophyllide-a [DV-(P)Chlide-a] in the green sulfur bacterium Chlorobaculum (Cba.) tepidum, was reconstructed on the basis of the previous study reported by Chew and Bryant [J. Biol. Chem.2007, 282, 2967-2975]. Cba. tepidum biosynthesizes the following three different types of chlorophylls (Chls) through their common precursory DV-(P)Chlide-a as its photosynthetically active pigments: bacteriochlorophyll(BChl)-c and Chl-a with the partially reduced 17,18-trans-dihydroporphyrin and BChl-a with the further reduced 7,8-trans-17,18-trans-tetrahydroporphyrin. The structures of Chls thus produced were characterized in detail by various spectroscopic techniques. In the mutant, both BChl-c and Chl-a possessing the alkyl group at the 8-position were exclusively replaced by their 8-vinylated derivatives, whereas BChl-a possessed the original 8-ethyl group. The present observations were inconsistent with the previous report. However, it was apparently confirmed that the enzyme BciA was responsible for the reduction of DV-(P)Chlide-a to produce BChl-c and Chl-a. Noteworthily, exclusive accumulation of the reduced (8-ethylated) form of BChl-a, not its 8-vinylated derivative, in the mutant indicates the presence of another enzyme catalyzing the 8-vinyl reduction as yet unidentified or any other reduction mechanism using a known enzyme to yield BChl-a.

  12. The chlorosome of Chlorobaculum tepidum: size, mass and protein composition revealed by electron microscopy, dynamic light scattering and mass spectrometry-driven proteomics.

    PubMed

    Kouyianou, Kalliopi; De Bock, Pieter-Jan; Müller, Shirley A; Nikolaki, Antigoni; Rizos, Apostolos; Krzyžánek, Vladislav; Aktoudianaki, Aikaterini; Vandekerckhove, Joël; Engel, Andreas; Gevaert, Kris; Tsiotis, Georgios

    2011-07-01

    Chlorosomes, the antenna complexes of green bacteria, are unique antenna systems in which pigments are organized in aggregates. Studies on isolated chlorosomes from Chlorobaculum tepidum based on SDS-PAGE, immunoblotting and molecular biology have revealed that they contain ten chlorosomal proteins, but no comprehensive information is available about the protein composition of the entire organelle. To extend these studies, chlorosomes were isolated from C. tepidum using three related and one independent isolation protocol and characterized by absorption spectroscopy, tricine SDS-PAGE, dynamic light scattering (DLS) and electron microscopy. Tricine SDS-PAGE showed the presence of more than 20 proteins with molecular weights ranging between 6 and 70 kDa. The chlorosomes varied in size. Their hydrodynamic radius (R(h) ) ranged from 51 to 75 nm and electron microscopy indicated that they were on average 140 nm wide and 170 nm long. Furthermore, the mass of 184 whole chlorosome organelles determined by scanning transmission electron microscopy ranged from 27 to 237 MDa being on average 88 (±28) MDa. In contrast their mass-per-area was independent of their size, indicating that there is a strict limit to chlorosome thickness. The average protein composition of the C. tepidum chlorosome organelles was obtained by MS/MS-driven proteomics and for the first time a detailed protein catalogue of the isolated chlorosomal proteome is presented. Based on the proteomics results for chlorosomes isolated by different protocols, four proteins that are involved in the electron or ion transport are proposed to be tightly associated with or incorporated into C. tepidum chlorosomes as well as the ten Csm proteins known to date.

  13. A heterogeneous tag-attachment to the homodimeric type 1 photosynthetic reaction center core protein in the green sulfur bacterium Chlorobaculum tepidum.

    PubMed

    Azai, Chihiro; Kim, Kwang; Kondo, Toru; Harada, Jiro; Itoh, Shigeru; Oh-oka, Hirozo

    2011-07-01

    The 6xHis-tag-pscA gene, which was genetically engineered to express N-terminally histidine (His)-tagged PscA, was inserted into a coding region of the recA gene in the green sulfur bacterium Chlorobaculum tepidum (C. tepidum). Although the inactivation of the recA gene strongly suppressed a homologous recombination in C. tepidum genomic DNA, the mutant grew well under normal photosynthetic conditions. The His-tagged reaction center (RC) complex could be obtained simply by Ni(2+)-affinity chromatography after detergent solubilization of chlorosome-containing membranes. The complex consisted of three subunits, PscA, PscB, and PscC, in addition to the Fenna-Matthews-Olson protein, but there was no PscD. Low-temperature EPR spectroscopic studies in combination with transient absorption measurements indicated that the complex contained all intrinsic electron transfer cofactors as detected in the wild-type strain. Furthermore, the LC/MS/MS analysis revealed that the core protein consisted of a mixture of a His-/His-tagged PscA homodimer and a non-/His-tagged PscA heterodimer. The development of the pscA gene duplication method presented here, thus, enables not only a quick and large-scale preparation of the RC complex from C. tepidum but also site-directed mutagenesis experiments on the artificially incorporated 6xHis-tag-pscA gene itself, since the expression of the authentic PscA/PscA homodimeric RC complex could complement any defect in mutated His-tagged PscA. This method would provide an invaluable tool for structural and functional analyses of the homodimeric type 1 RC complex.

  14. Metabolic analysis of Chlorobium chlorochromatii CaD3 reveals clues of the symbiosis in ‘Chlorochromatium aggregatum'.

    PubMed Central

    Cerqueda-García, Daniel; Martínez-Castilla, León P; Falcón, Luisa I; Delaye, Luis

    2014-01-01

    A symbiotic association occurs in ‘Chlorochromatium aggregatum', a phototrophic consortium integrated by two species of phylogenetically distant bacteria composed by the green-sulfur Chlorobium chlorochromatii CaD3 epibiont that surrounds a central β-proteobacterium. The non-motile chlorobia can perform nitrogen and carbon fixation, using sulfide as electron donors for anoxygenic photosynthesis. The consortium can move due to the flagella present in the central β-protobacterium. Although Chl. chlorochromatii CaD3 is never found as free-living bacteria in nature, previous transcriptomic and proteomic studies have revealed that there are differential transcription patterns between the symbiotic and free-living status of Chl. chlorocromatii CaD3 when grown in laboratory conditions. The differences occur mainly in genes encoding the enzymatic reactions involved in nitrogen and amino acid metabolism. We performed a metabolic reconstruction of Chl. chlorochromatii CaD3 and an in silico analysis of its amino acid metabolism using an elementary flux modes approach (EFM). Our study suggests that in symbiosis, Chl. chlorochromatii CaD3 is under limited nitrogen conditions where the GS/GOGAT (glutamine synthetase/glutamate synthetase) pathway is actively assimilating ammonia obtained via N2 fixation. In contrast, when free-living, Chl. chlorochromatii CaD3 is in a condition of nitrogen excess and ammonia is assimilated by the alanine dehydrogenase (AlaDH) pathway. We postulate that ‘Chlorochromatium aggregatum' originated from a parasitic interaction where the N2 fixation capacity of the chlorobia would be enhanced by injection of 2-oxoglutarate from the β-proteobacterium via the periplasm. This consortium would have the advantage of motility, which is fundamental to a phototrophic bacterium, and the syntrophy of nitrogen and carbon sources. PMID:24285361

  15. Metabolic analysis of Chlorobium chlorochromatii CaD3 reveals clues of the symbiosis in 'Chlorochromatium aggregatum'.

    PubMed

    Cerqueda-García, Daniel; Martínez-Castilla, León P; Falcón, Luisa I; Delaye, Luis

    2014-05-01

    A symbiotic association occurs in 'Chlorochromatium aggregatum', a phototrophic consortium integrated by two species of phylogenetically distant bacteria composed by the green-sulfur Chlorobium chlorochromatii CaD3 epibiont that surrounds a central β-proteobacterium. The non-motile chlorobia can perform nitrogen and carbon fixation, using sulfide as electron donors for anoxygenic photosynthesis. The consortium can move due to the flagella present in the central β-protobacterium. Although Chl. chlorochromatii CaD3 is never found as free-living bacteria in nature, previous transcriptomic and proteomic studies have revealed that there are differential transcription patterns between the symbiotic and free-living status of Chl. chlorocromatii CaD3 when grown in laboratory conditions. The differences occur mainly in genes encoding the enzymatic reactions involved in nitrogen and amino acid metabolism. We performed a metabolic reconstruction of Chl. chlorochromatii CaD3 and an in silico analysis of its amino acid metabolism using an elementary flux modes approach (EFM). Our study suggests that in symbiosis, Chl. chlorochromatii CaD3 is under limited nitrogen conditions where the GS/GOGAT (glutamine synthetase/glutamate synthetase) pathway is actively assimilating ammonia obtained via N2 fixation. In contrast, when free-living, Chl. chlorochromatii CaD3 is in a condition of nitrogen excess and ammonia is assimilated by the alanine dehydrogenase (AlaDH) pathway. We postulate that 'Chlorochromatium aggregatum' originated from a parasitic interaction where the N2 fixation capacity of the chlorobia would be enhanced by injection of 2-oxoglutarate from the β-proteobacterium via the periplasm. This consortium would have the advantage of motility, which is fundamental to a phototrophic bacterium, and the syntrophy of nitrogen and carbon sources.

  16. Gene sequencing and characterization of the light-harvesting complex 2 from thermophilic purple sulfur bacterium Thermochromatium tepidum.

    PubMed

    Sekine, Fumie; Horiguchi, Kentaro; Kashino, Yasuhiro; Shimizu, Yuuki; Yu, Long-Jiang; Kobayashi, Masayuki; Wang, Zheng-Yu

    2012-03-01

    In this study, gene sequences coding for the light-harvesting (LH) 2 polypeptides from a thermophilic purple sulfur bacterium Thermochromatium tepidum are reported and characterization of the LH2 complex is described. Three sets of pucBA genes have been identified, and the gene products have been analyzed by electrophoresis and reversed-phase chromatography. The result shows that all of the genes are expressed but the distribution of the expression is not uniform. The gene products undergo post-translational modification, where two of the β-polypeptides appear to be N-terminally methylated. Absorption spectrum of the purified LH2 complex exhibits Q (y) transitions at 800 and 854 nm in dodecyl β-maltopyranoside solution, and the circular dichroism spectrum shows a "molischianum"-like characteristic. No spectral change was observed for the LH2 when the bacterium was cultured under different conditions of light intensity. In lauryl dimethylamine N-oxide (LDAO) solution, significant changes in the absorption spectrum were observed. The B850 peak decreased and blue-shifted with increasing the LDAO concentration, whereas the B800 intensity increased without change in the peak position. The spectral changes can be partially or almost completely reversed by addition of metal ions, and the divalent cations seem to be more effective. The results indicate that ionic interactions may exist between LH2, detergent molecules and metal ions. Possible mechanisms involved in the detergent- and cation-induced spectral changes are discussed.

  17. Alternative Excitonic Structure in the Baseplate (BChl a-CsmA Complex) of the Chlorosome from Chlorobaculum tepidum.

    PubMed

    Kell, Adam; Chen, Jinhai; Jassas, Mahboobe; Tang, Joseph Kuo-Hsiang; Jankowiak, Ryszard

    2015-07-16

    In the photosynthetic green sulfur bacterium Chlorobaculum tepidum, the baseplate mediates excitation energy transfer from the light-harvesting chlorosome to the Fenna-Matthews-Olson (FMO) complex and subsequently toward the reaction center (RC). Literature data suggest that the baseplate is a 2D lattice of BChl a-CsmA dimers. However, recently, it has been proposed, using 2D electronic spectroscopy (2DES) at 77 K, that at least four excitonically coupled BChl a are in close contact within the baseplate structure [ Dostál , J. ; et al., J. Phys. Chem. Lett. 2014 , 5 , 1743 ]. This finding is tested via hole burning (HB) spectroscopy (5 K). Our results indicate that the four excitonic states identified by 2DES likely correspond to contamination of the baseplate with the FMO antenna and possibly the RC. In contrast, HB reveals a different excitonic structure of the baseplate chromophores, where excitation is transferred to a localized trap state near 818 nm via exciton hopping, which leads to emission near 826 nm.

  18. A monogalactosyldiacylglycerol synthase found in the green sulfur bacterium Chlorobaculum tepidum reveals important roles for galactolipids in photosynthesis.

    PubMed

    Masuda, Shinji; Harada, Jiro; Yokono, Makio; Yuzawa, Yuichi; Shimojima, Mie; Murofushi, Kazuhiro; Tanaka, Hironori; Masuda, Hanako; Murakawa, Masato; Haraguchi, Tsuyoshi; Kondo, Maki; Nishimura, Mikio; Yuasa, Hideya; Noguchi, Masato; Oh-Oka, Hirozo; Tanaka, Ayumi; Tamiaki, Hitoshi; Ohta, Hiroyuki

    2011-07-01

    Monogalactosyldiacylglycerol (MGDG), which is conserved in almost all photosynthetic organisms, is the most abundant natural polar lipid on Earth. In plants, MGDG is highly accumulated in the chloroplast membranes and is an important bulk constituent of thylakoid membranes. However, precise functions of MGDG in photosynthesis have not been well understood. Here, we report a novel MGDG synthase from the green sulfur bacterium Chlorobaculum tepidum. This enzyme, MgdA, catalyzes MGDG synthesis using UDP-Gal as a substrate. The gene encoding MgdA was essential for this bacterium; only heterozygous mgdA mutants could be isolated. An mgdA knockdown mutation affected in vivo assembly of bacteriochlorophyll c aggregates, suggesting the involvement of MGDG in the construction of the light-harvesting complex called chlorosome. These results indicate that MGDG biosynthesis has been independently established in each photosynthetic organism to perform photosynthesis under different environmental conditions. We complemented an Arabidopsis thaliana MGDG synthase mutant by heterologous expression of MgdA. The complemented plants showed almost normal levels of MGDG, although they also had abnormal morphological phenotypes, including reduced chlorophyll content, no apical dominance in shoot growth, atypical flower development, and infertility. These observations provide new insights regarding the importance of regulated MGDG synthesis in the physiology of higher plants.

  19. Calcium ions are required for the enhanced thermal stability of the light-harvesting-reaction center core complex from thermophilic purple sulfur bacterium Thermochromatium tepidum.

    PubMed

    Kimura, Yukihiro; Yu, Long-Jiang; Hirano, Yu; Suzuki, Hiroaki; Wang, Zheng-Yu

    2009-01-02

    Thermochromatium tepidum is a thermophilic purple sulfur photosynthetic bacterium collected from the Mammoth Hot Springs, Yellowstone National Park. A previous study showed that the light-harvesting-reaction center core complex (LH1-RC) purified from this bacterium is highly stable at room temperature (Suzuki, H., Hirano, Y., Kimura, Y., Takaichi, S., Kobayashi, M., Miki, K., and Wang, Z.-Y. (2007) Biochim. Biophys. Acta 1767, 1057-1063). In this work, we demonstrate that thermal stability of the Tch. tepidum LH1-RC is much higher than that of its mesophilic counterparts, and the enhanced thermal stability requires Ca2+ as a cofactor. Removal of the Ca2+ from Tch. tepidum LH1-RC resulted in a complex with the same degree of thermal stability as that of the LH1-RCs purified from mesophilic bacteria. The enhanced thermal stability can be restored by addition of Ca2+ to the Ca2+-depleted LH1-RC, and this process is fully reversible. Interchange of the thermal stability between the two forms is accompanied by a shift of the LH1 Qy transition between 915 nm for the native and 880 nm for the Ca2+-depleted LH1-RC. Differential scanning calorimetry measurements reveal that degradation temperature of the native LH1-RC is 15 degrees C higher and the enthalpy change is about 28% larger than the Ca2+-depleted LH1-RC. Substitution of the Ca2+ with other metal cations caused a decrease in thermal stability of an extent depending on the properties of the cations. These results indicate that Ca2+ ions play a dual role in stabilizing the structure of the pigment-membrane protein complex and in altering its spectroscopic properties, and hence provide insight into the adaptive strategy of this photosynthetic organism to survive in extreme environments using natural resources.

  20. The roles of C-terminal residues on the thermal stability and local heme environment of cytochrome c' from the thermophilic purple sulfur bacterium Thermochromatium tepidum.

    PubMed

    Kimura, Yukihiro; Kasuga, Sachiko; Unno, Masashi; Furusawa, Takashi; Osoegawa, Shinsuke; Sasaki, Yuko; Ohno, Takashi; Wang-Otomo, Zheng-Yu

    2015-04-01

    A soluble cytochrome (Cyt) c' from thermophilic purple sulfur photosynthetic bacterium Thermochromatium (Tch.) tepidum exhibits marked thermal tolerance compared with that from the closely related mesophilic counterpart Allochromatium vinosum. Here, we focused on the difference in the C-terminal region of the two Cyts c' and examined the effects of D131 and R129 mutations on the thermal stability and local heme environment of Cyt c' by differential scanning calorimetry (DSC) and resonance Raman (RR) spectroscopy. In the oxidized forms, D131K and D131G mutants exhibited denaturing temperatures significantly lower than that of the recombinant control Cyt c'. In contrast, R129K and R129A mutants denatured at nearly identical temperatures with the control Cyt c', indicating that the C-terminal D131 is an important residue maintaining the enhanced thermal stability of Tch. tepidum Cyt c'. The control Cyt c' and all of the mutants increased their thermal stability upon the reduction. Interestingly, D131K exhibited narrow DSC curves and unusual thermodynamic parameters in both redox states. The RR spectra of the control Cyt c' exhibited characteristic bands at 1,635 and 1,625 cm(-1), ascribed to intermediate spin (IS) and high spin (HS) states, respectively. The IS/HS distribution was differently affected by the D131 and R129 mutations and pH changes. Furthermore, R129 mutants suggested the lowering of their redox potentials. These results strongly indicate that the D131 and R129 residues play significant roles in maintaining the thermal stability and modulating the local heme environment of Tch. tepidum Cyt c'.

  1. Bacteriochlorophyllide c C-8(2) and C-12(1) methyltransferases are essential for adaptation to low light in Chlorobaculum tepidum.

    PubMed

    Gomez Maqueo Chew, Aline; Frigaard, Niels-Ulrik; Bryant, Donald A

    2007-09-01

    Bacteriochlorophyll (BChl) c is the major photosynthetic pigment in the green sulfur bacterium Chlorobaculum tepidum, in which it forms protein-independent aggregates that function in light harvesting. BChls c, d, and e are found only in chlorosome-producing bacteria and are unique among chlorophylls because of methylations that occur at the C-8(2) and C-12(1) carbons. Two genes required for these methylation reactions were identified and designated bchQ (CT1777) and bchR (CT1320). BchQ and BchR are members of the radical S-adenosylmethionine (SAM) protein superfamily; each has sequence motifs to ligate a [4Fe-4S] cluster, and we propose that they catalyze the methyl group transfers. bchQ, bchR, and bchQ bchR mutants of C. tepidum were constructed and characterized. The bchQ mutant produced BChl c that was not methylated at C-8(2), the bchR mutant produced BChl c that was not methylated at C-12(1), and the double mutant produced [8-ethyl, 12-methyl]-BChl c that lacked methylation at both the C-8(2) and C-12(1) positions. Compared to the wild type, the Qy absorption bands for BChl c in the mutant cells were narrower and blue shifted to various extents. All three mutants grew slower and had a lower cellular BChl c content than the wild type, an effect that was especially pronounced at low light intensities. These observations show that the C-8(2) and C-12(1) methylations of BChl c play important roles in the adaptation of C. tepidum to low light intensity. The data additionally suggest that these methylations also directly or indirectly affect the regulation of the BChl c biosynthetic pathway.

  2. Structure and organization of a 25 kbp region of the genome of the photosynthetic green sulfur bacterium Chlorobium vibrioforme containing Mg-chelatase encoding genes.

    PubMed

    Petersen, B L; Møller, M G; Stummann, B M; Henningsen, K W

    1998-01-01

    A region comprising approximately 25 kbp of the genome of the strictly anaerobic and obligate photosynthetic green sulfur bacterium Chlorobium vibrioforme has been mapped, subcloned and partly sequenced. Approximately 15 kbp have been sequenced in it's entirety and three genes with significant homology and feature similarity to the bchI, -D and -H genes and the chlI, -D and -H genes of Rhodobacter and Synechocystis strain PCC6803, respectively, which encode magnesium chelatase subunits, have been identified. Magnesium chelatase catalyzes the insertion of Mg2+ into protoporphyrin IX, and is the first enzyme unique to the (bacterio)chlorophyll specific branch of the porphyrin biosynthetic pathway. The organization of the three Mg-chelatase encoding genes is unique to Chlorobium and suggests that the magnesium chelatase of C. vibrioforme is encoded by a single operon. The analyzed 25 kbp region contains five additional open reading frames, two of which display significant homology and feature similarity to genes encoding lipoamide dehydrogenase and genes with function in purine synthesis, and another three display significant homology to open reading frames with unknown function in distantly related bacteria. Putative E. coli sigma 70-like promoter sequences, ribosome binding sequences and rho-independent transcriptional stop signals within the sequenced 15 kbp region are related to the identified genes and orfs. Southern analysis, restriction mapping and partial sequencing of the remaining ca. 10 kbp of the analyzed 25 kbp region have shown that this part includes the hemA, -C, -D and -B genes (MOBERG and AVISSAR 1994), which encode enzymes with function in the early part of the biosynthetic pathway of porphyrins.

  3. Biosynthesis of bacteriochlorophyll c derivatives possessing chlorine and bromine atoms at the terminus of esterifying chains in the green sulfur bacterium Chlorobaculum tepidum.

    PubMed

    Saga, Yoshitaka; Hayashi, Keisuke; Mizoguchi, Tadashi; Tamiaki, Hitoshi

    2014-07-01

    The green sulfur photosynthetic bacterium Chlorobaculum tepidum newly produced BChl c derivatives possessing a chlorine or bromine atom at the terminus of the esterifying chain in the 17-propionate residue by cultivation with exogenous ω-halo-1-alkanols. The relative ratios of BChl c derivatives esterified with 8-chloro-1-octanol and 10-chloro-1-decanol were estimated to be 26.5% and 33.3% by cultivation with these ω-chloro-1-alkanols at the final concentrations of 300 and 150 μM, respectively. In contrast, smaller amounts of unnatural BChls c esterified with ω-bromo-1-alkanols were biosynthesized than those esterified with ω-chloro-1-alkanols: the ratios of BChl c derivatives esterified with 8-bromo-1-octanol and 10-bromo-1-decanol were 11.3% and 12.2% at the concentrations of 300 and 150 μM, respectively. These indicate that ω-chloro-1-alkanols can be incorporated into bacteriochlorophyllide c more than ω-bromo-1-alkanols in the BChl c biosynthetic pathway. The homolog compositions of the novel BChl c derivatives possessing a halogen atom were analogous to those of coexisting natural BChl c esterified with farnesol. These results demonstrate unique properties of BChl c synthase, BchK, which can utilize unnatural substrates containing halogen in the BChl c biosynthesis of Cba. tepidum.

  4. Biochemical studies of a soxF-encoded monomeric flavoprotein purified from the green sulfur bacterium Chlorobaculum tepidum that stimulates in vitro thiosulfate oxidation.

    PubMed

    Ogawa, Takuro; Furusawa, Toshinari; Shiga, Michiko; Seo, Daisuke; Sakurai, Hidehiro; Inoue, Kazuhito

    2010-01-01

    In the green sulfur bacterium Chlorobaculum tepidum, three sulfur oxidizing enzyme system (Sox) proteins, SoxAXK, SoxYZ, and SoxB (the core TOMES, thiosulfate oxidizing multi-enzyme system) are essential to in vitro thiosulfate oxidation. We purified monomeric flavoprotein SoxF from this bacterium, which had sulfide dehydrogenase activity. SoxF enhanced the thiosulfate oxidation activity of the purified core TOMES with various cytochromes as electron acceptors to different degrees without any change in the affinity for thiosulfate. The apparent reaction rates with 50 microM- C. tepidum cytochrome c-554 were slightly higher than with horse-heart cytochrome c, and the addition of 0.5 microM- SoxF increased the rate by 92%. The rates with 50 microM- horse-heart cytochrome c and 50 muM- horse-heart cytochrome c plus 0.5 muM- cytochrome c-554 were increased by SoxF by 31% and 120% respectively. We conclude that SoxF mediates electron transfer between the components of core TOMES and externally added cytochromes.

  5. Structural Basis for the Unusual Qy Red-Shift and Enhanced Thermostability of the LH1 Complex from Thermochromatium tepidum.

    PubMed

    Yu, Long-Jiang; Kawakami, Tomoaki; Kimura, Yukihiro; Wang-Otomo, Zheng-Yu

    2016-11-29

    While the majority of the core light-harvesting complexes (LH1) in purple photosynthetic bacteria exhibit a Qy absorption band in the range of 870-890 nm, LH1 from the thermophilic bacterium Thermochromatium tepidum displays the Qy band at 915 nm with an enhanced thermostability. These properties are regulated by Ca(2+) ions. Substitution of the Ca(2+) with other divalent metal ions results in a complex with the Qy band blue-shifted to 880-890 nm and a reduced thermostability. Following the recent publication of the structure of the Ca-bound LH1-reaction center (RC) complex [Niwa, S., et al. (2014) Nature 508, 228], we have determined the crystal structures of the Sr- and Ba-substituted LH1-RC complexes with the LH1 Qy band at 888 nm. Sixteen Sr(2+) and Ba(2+) ions are identified in the LH1 complexes. Both Sr(2+) and Ba(2+) are located at the same positions, and these are clearly different from, though close to, the Ca(2+)-binding sites. Conformational rearrangement induced by the substitution is limited to the metal-binding sites. Unlike the Ca-LH1-RC complex, only the α-polypeptides are involved in the Sr and Ba coordinations in LH1. The difference in the thermostability between these complexes can be attributed to the different patterns of the network formed by metal binding. The Sr- and Ba-LH1-RC complexes form a single-ring network by the LH1 α-polypeptides only, in contrast to the double-ring network composed of both α- and β-polypeptides in the Ca-LH1-RC complex. On the basis of the structural information, a combined effect of hydrogen bonding, structural integrity, and charge distribution is considered to influence the spectral properties of the core antenna complex.

  6. Presence of exclusively bacteriochlorophyll-c containing substrain in the culture of green sulfur photosynthetic bacterium Chlorobium vibrioforme strain NCIB 8327 producing bacteriochlorophyll-d.

    PubMed

    Saga, Yoshitaka; Oh-oka, Hirozo; Hayashi, Takashi; Tamiaki, Hitoshi

    2003-12-01

    The light-dependent composition change of light harvesting bacteriochlorophyll(BChl)s in the present culture of a green sulfur photosynthetic bacterium Chlorobium (Chl.) vibrioforme f. sp. thiosulfatophilum strain NCIB 8327 was investigated by visible absorption spectroscopy and HPLC analyses. When the culture was repeatedly grown in liquid media under a low light condition, both the Soret and Qy absorption bands of the in vivo spectrum were shifted to longer wavelengths. Analysis of the extracted pigments by HPLC revealed that the ratio of the amount of BChl-c to that of BChl-d molecules gradually increased during repeated cultivation. In contrast, when the culture grown under a low light intensity was transferred to a high light condition and continued to be grown, the absorption bands were shifted to shorter wavelengths and the ratio of BChls-c/d decreased finally to the almost original value. Colonies were prepared on solid agar media from the liquid culture containing both BChls-c and d, which was grown under a low light intensity. Each colony obtained was found to contain either BChl-c or d, but not both of them. Two types of cells isolated in this study were derived from the same clone, judged from their genetic analyses. The variation of pigment composition in our liquid culture observed here could be ascribed to the difference of growth rates between two substrains containing BChl-c and BChl-d, respectively, depending on light conditions.

  7. The origin of the unusual Qy red shift in LH1-RC complexes from purple bacteria Thermochromatium tepidum as revealed by Stark absorption spectroscopy.

    PubMed

    Ma, Fei; Yu, Long-Jiang; Wang-Otomo, Zheng-Yu; van Grondelle, Rienk

    2015-12-01

    Native LH1-RC of photosynthetic purple bacteria Thermochromatium (Tch.) tepidum, B915, has an ultra-red BChl a Qy absorption. Two blue-shifted complexes obtained by chemical modification, B893 and B882, have increasing full widths at half maximum (FWHM) and decreasing transition dipole oscillator strength. 77K Stark absorption spectroscopy studies were employed for the three complexes, trying to understand the origin of the 915 nm absorption. We found that Tr(∆α) and |∆μ| of both Qy and carotenoid (Car) bands are larger than for other purple bacterial LH complexes reported previously. Moreover, the red shifts of the Qy bands are associated with (1) increasing Tr(∆α) and |∆μ| of the Qy band, (2) the red shift of the Car Stark signal and (3) the increasing |∆μ| of the Car band. Based on the results and the crystal structure, a combined effect of exciton-charge transfer (CT) states mixing, and inhomogeneous narrowing of the BChl a site energy is proposed to be the origin of the 915 nm absorption. CT-exciton state mixing has long been found to be the origin of strong Stark signal in LH1 and special pair, and the more extent of the mixing in Tch. tepidum LH1 is mainly the consequence of the shorter BChl-BChl distances. The less flexible protein structure results in a smaller site energy disorder (inhomogeneous narrowing), which was demonstrated to be able to influence |∆μ| and absorption.

  8. Specific Ca2+-binding motif in the LH1 complex from photosynthetic bacterium Thermochromatium tepidum as revealed by optical spectroscopy and structural modeling.

    PubMed

    Ma, Fei; Kimura, Yukihiro; Yu, Long-Jiang; Wang, Peng; Ai, Xi-Cheng; Wang, Zheng-Yu; Zhang, Jian-Ping

    2009-03-01

    Native and Ca(2+)-depleted light-harvesting-reaction center core complexes (LH1-RC) from the photosynthetic bacterium Thermochromatium (Tch.) tepidum exhibit maximal LH1-Q(y) absorption at 915 and 889 nm, respectively. To understand the structural origins of the spectral variation, we performed spectroscopic and structure modeling investigations. For the 889 nm form of LH1-RC, bacteriochlorophyll a (BChl a) in the native form was found by means of near-infrared Fourier-transform Raman spectroscopy, a higher degree of macrocycle distortion and a stronger hydrogen bond with the beta-Trp(-8) residue. SWISS-MODEL structure modeling suggests the presence of a specific coordination motif of Ca(2+) at the C-terminus of the alpha-subunit of LH1, while MODELLER reveals the tilt of alpha- and beta-polypeptides with reference to the structural template, as well as a change in the concentric orientation of BChl a molecules, both of which may be connected to the long-wavelength LH1-Q(y) absorption of the 915 nm form. The carotenoid spirilloxanthin shows a twisted all-trans configuration in both forms of LH1 as evidenced by the resonance Raman spectroscopic results. With regard to the thermal stability, the 915 nm form was shown by the use of temperature-dependent fluorescence spectroscopy to be approximately 20 K more stable than the 889 nm form, which may be ascribed to the specific Ca(2+)-binding motif of LH1.

  9. The impact of different intensities of green light on the bacteriochlorophyll homologue composition of the Chlorobiaceae Prosthecochloris aestuarii and Chlorobium phaeobacteroides.

    PubMed

    Massé, Astrid; Airs, Ruth L; Keely, Brendan J; de Wit, Rutger

    2004-08-01

    Members of the Chlorobiaceae and Chloroflexaceae are unique among the phototrophic micro-organisms in having a remarkably rich chlorophyll pigment diversity. The physiological regulation of this diversity and its ecological implications are still enigmatic. The bacteriochlorophyll composition of the chlorobiaceae Prosthecochloris aestuarii strain CE 2404 and Chlorobium phaeobacteroides strain UdG 6030 was therefore studied by both HPLC with photodiode array (PDA) detection and liquid chromatography-mass spectrometry (LC-MS). These strains were grown in liquid cultures under green light (480-615 nm) at different light intensities (0.2-55.7 micromol photons m(-2) s(-1)), simulating the irradiance regime at different depths of the water column of deep lakes. The specific growth rates of Ptc. aestuarii under green light achieved a maximum of 0.06 h(-1) at light intensities exceeding 6 micromol photons m(-2) s(-1), lower than the maximum observed under white light (approx. 0.1 h(-1)). The maximal growth rates of Chl. phaeobacteroides under green light were slightly higher (0.07 h(-1)) than observed for Ptc. aestuarii and were achieved at 3.5 and 4.3 micromol photons m(-2) s(-1). LC-MS/MS analysis of pigment extracts revealed most (>90 %) BChl c homologues of Ptc. aestuarii to be esterified with farnesol. The homologues differed in mass by multiples of 14 Da, reflecting different alkyl subsituents at positions C-8 and C-12 on the tetrapyrrole macrocycle. The relative proportions of the individual homologues varied only slightly among different light intensities. The specific content of BChl c was maximal at 3-5 micromol photons m(-2) s(-1) [400+/-150 nmol BChl c (mg protein)(-1)]. In the case of Chl. phaeobacteroides, the specific content of BChl e was maximal at 4.3 micromol photons m(-2) s(-1) [115 nmol BChl e (mg protein)(-1)], and this species was characterized by high carotenoid (isorenieratene) contents. The major BChl e forms were esterified with a range of

  10. Characterization of three homologs of the large subunit of the magnesium chelatase from Chlorobaculum tepidum and interaction with the magnesium protoporphyrin IX methyltransferase.

    PubMed

    Johnson, Ethan T; Schmidt-Dannert, Claudia

    2008-10-10

    Green bacteria synthesize several types of (bacterio)chlorophylls for the assembly of functional photosynthetic reaction centers and antenna complexes. A distinctive feature of green bacteria compared with other photosynthetic microbes is that their genomes contain multiple homologs of the large subunit (BchH) of the magnesium chelatase which is a three-subunit enzyme complex (BchH, BchD, and BchI) that inserts magnesium into protoporphyrin IX as the first committed step of (bacterio)chlorophyll biosynthesis. There is speculation that the additional BchH homologs may regulate the biosynthesis of each type of chlorophyll, although the biochemical properties of the different magnesium chelatase complexes from a single species of green bacteria have not yet been compared. In this study, we investigated the activities of all three chelatase complexes from the green sulfur bacterium Chlorobaculum tepidum and interactions with the next enzyme in the pathway, magnesium protoporphyrin IX methyltransferase (BchM). Although all three chelatase complexes insert magnesium into protoporphyrin IX, the activities range by a factor of 10(5). Further, there are differences in the interactions between the BchH homologs and BchM; two of the subunits increase the methyltransferase activity by 30-60%, and the third decreases it by 30%. Expression of the chelatase complexes alone and together with BchM in Escherichia coli overproducing protoporphyrin IX suggests that the chelatase is the rate-limiting enzyme. We observed that BchM uses protoporphyrin IX without bound metal as a substrate. Our results conflict with expectations generated by previous gene inactivation studies and suggest a complex regulation of chlorophyll biosynthesis in green bacteria.

  11. Calcium ions are involved in the unusual red shift of the light-harvesting 1 Qy transition of the core complex in thermophilic purple sulfur bacterium Thermochromatium tepidum.

    PubMed

    Kimura, Yukihiro; Hirano, Yu; Yu, Long-Jiang; Suzuki, Hiroaki; Kobayashi, Masayuki; Wang, Zheng-Yu

    2008-05-16

    Thermophilic purple sulfur bacterium, Thermochromatium tepidum, can grow at temperatures up to 58 degrees C and exhibits an unusual Qy absorption at 915 nm for the core light-harvesting complex (LH1), an approximately 35-nm red shift from those of its mesophilic counterparts. We demonstrate in this study, using a highly purified LH1-reaction center complex, that the LH1 Qy transition is strongly dependent on metal cations and Ca2+ is involved in the unusual red shift. Removal of the Ca2+ resulted in formation of a species with the LH1 Qy absorption at 880 nm, and addition of the Ca2+ to the 880-nm species recovered the native 915-nm form. Interchange between the two forms is fully reversible. Based on spectroscopic and isothermal titration calorimetry analyses, the Ca2+ binding to the LH1 complex was estimated to occur in a stoichiometric ratio of Ca2+/alphabeta-subunit = 1:1 and the binding constant was in 10(5) m(-1) order of magnitude, which is comparable with those for EF-hand Ca2+-binding proteins. Despite the high affinity, conformational changes in the LH1 complex upon Ca2+ binding were small and occurred slowly, with a typical time constant of approximately 6 min. Replacement of the Ca2+ with other metal cations caused blue shifts of the Qy bands depending on the property of the cations, indicating that the binding site is highly selective. Based on the amino acid sequences of the LH1 complex, possible Ca2+-binding sites are proposed that consist of several acidic amino acid residues near the membrane interfaces of the C-terminal region of the alpha-polypeptide and the N-terminal region of the beta-polypeptide.

  12. Structural variability in wild-type and bchQ bchR mutant chlorosomes of the green sulfur bacterium Chlorobaculum tepidum.

    PubMed

    Ganapathy, Swapna; Oostergetel, Gert T; Reus, Michael; Tsukatani, Yusuke; Gomez Maqueo Chew, Aline; Buda, Francesco; Bryant, Donald A; Holzwarth, Alfred R; de Groot, Huub J M

    2012-06-05

    The self-aggregated state of bacteriochlorophyll (BChl) c molecules in chlorosomes belonging to a bchQ bchR mutant of the green sulfur bacteria Chlorobaculum tepidum, which mostly produces a single 17(2)-farnesyl-(R)-[8-ethyl,12-methyl]BChl c homologue, was characterized by solid-state nuclear magnetic resonance (NMR) spectroscopy and high-resolution electron microscopy. A nearly complete (1)H and (13)C chemical shift assignment was obtained from well-resolved homonuclear (13)C-(13)C and heteronuclear (1)H-(13)C NMR data sets collected from (13)C-enriched chlorosome preparations. Pronounced doubling (1:1) of specific (13)C and (1)H resonances revealed the presence of two distinct and nonequivalent BChl c components, attributed to all syn- and all anti-coordinated parallel stacks, depending on the rotation of the macrocycle with respect to the 3(1)-methyl group. Steric hindrance from the 20-methyl functionality induces structural differences between the syn and anti forms. A weak but significant and reproducible reflection at 1/0.69 nm(-1) in the direction perpendicular to the curvature of cylindrical segments observed with electron microscopy also suggests parallel stacking of BChl c molecules, though the observed lamellar spacing of 2.4 nm suggests weaker packing than for wild-type chlorosomes. We propose that relaxation of the pseudosymmetry observed for the wild type and a related BChl d mutant leads to extended domains of alternating syn and anti stacks in the bchQ bchR chlorosomes. Domains can be joined to form cylinders by helical syn-anti transition trajectories. The phase separation in domains on the cylindrical surface represents a basic mechanism for establishing suprastructural heterogeneity in an otherwise uniform supramolecular scaffolding framework that is well-ordered at the molecular level.

  13. Reconstitution of an active magnesium chelatase enzyme complex from the bchI, -D, and -H gene products of the green sulfur bacterium Chlorobium vibrioforme expressed in Escherichia coli.

    PubMed

    Petersen, B L; Jensen, P E; Gibson, L C; Stummann, B M; Hunter, C N; Henningsen, K W

    1998-02-01

    Magnesium-protoporphyrin chelatase, the first enzyme unique to the (bacterio)chlorophyll-specific branch of the porphyrin biosynthetic pathway, catalyzes the insertion of Mg2+ into protoporphyrin IX. Three genes, designated bchI, -D, and -H, from the strictly anaerobic and obligately phototrophic green sulfur bacterium Chlorobium vibrioforme show a significant level of homology to the magnesium chelatase-encoding genes bchI, -D, and -H and chlI, -D, and -H of Rhodobacter sphaeroides and Synechocystis strain PCC6803, respectively. These three genes were expressed in Escherichia coli; the subsequent purification of overproduced BchI and -H proteins on an Ni2+-agarose affinity column and denaturation of insoluble BchD protein in 6 M urea were required for reconstitution of Mg-chelatase activity in vitro. This work therefore establishes that the magnesium chelatase of C. vibrioforme is similar to the magnesium chelatases of the distantly related bacteria R. sphaeroides and Synechocystis strain PCC6803 with respect to number of subunits and ATP requirement. In addition, reconstitution of an active heterologous magnesium chelatase enzyme complex was obtained by combining the C. vibrioforme BchI and -D proteins and the Synechocystis strain PCC6803 ChlH protein. Furthermore, two versions, with respect to the N-terminal start of the bchI gene product, were expressed in E. coli, yielding ca. 38- and ca. 42-kDa versions of the BchI protein, both of which proved to be active. Western blot analysis of these proteins indicated that two forms of BchI, corresponding to the 38- and the 42-kDa expressed proteins, are also present in C. vibrioforme.

  14. Energy transfer and exciton coupling in isolated B800-850 complexes of the photosynthetic purple sulfur bacterium Choromatium tepidum. The effect of structural symmetry on bacteriochlorophyll excited states

    SciTech Connect

    Kennis, J.T.M.; Streltsov, A.M.; Aartsma, T.J.; Amesz, J.; Nozawa, Tsunenori

    1996-02-08

    Energy transfer and exciton coupling in isolated B800-850 complexes from the purple sulfur bacterium Chromatium tepidum were studied by means of spectrally resolved absorbance difference spectroscopy with a time resolution of 200 fs. Energy transfer from bacteriochlorophyll (BChl) 800 to BChl 850 was found to occur with a time constant of 0.8-0.9 ps. Remarkably, the amplitude of the absorbance changes of BChl 850 was 4 times larger than that of BChl 800. By relating this result to the crystal structure of B800-850 complexes of Rhodopseudomonas acidophila, it was concluded that the spectral properties of BChl 850 are mainly determined by strong exciton interactions between BChl 850 molecules in a circular symmetric arrangement, which lead to concentration of the oscillator strength in a few optically allowed transitions, corresponding to delocalized eigenstates. In BChl 850, a rapid red shift of the bleaching was observed. This relaxation process may be ascribed either to vibrational relaxation or exciton scattering. A similar red shift appears to occur in BChl 800. 26 refs., 5 figs.

  15. Temperature dependent LH1→RC energy transfer in purple bacteria Tch. tepidum with shiftable LH1-Qy band: A natural system to investigate thermally activated energy transfer in photosynthesis.

    PubMed

    Ma, Fei; Yu, Long-Jiang; Wang-Otomo, Zheng-Yu; van Grondelle, Rienk

    2016-04-01

    The native LH1-RC complex of the purple bacterium Thermochromatium (Tch.) tepidum has an ultra-red LH1-Qy absorption at 915nm, which can shift to 893 and 882nm by means of chemical modifications. These unique complexes are a good natural system to investigate the thermally activated energy transfer process, with the donor energies different while the other factors (such as the acceptor energy, special pair at 890nm, and the distance/relative orientation between the donor and acceptor) remain the same. The native B915-RC, B893-RC and B882-RC complexes, as well as the LH1-RC complex of Rhodobacter (Rba.) sphaeroides were studied by temperature-dependent time-resolved absorption spectroscopy. The energy transfer time constants, kET(-1), are 65, 45, 46 and 45ps at room temperature while 225, 58, 85, 33ps at 77K for the B915-RC, B893-RC, B882-RC and Rba. sphaeroides LH1-RC, respectively. The dependences of kET on temperature have different trends. The reorganization energies are determined to be 70, 290, 200 and 45cm(-1), respectively, by fitting kET vs temperature using Marcus equation. The activation energies are 200, 60, 115 and 20cm(-1), respectively. The influences of the structure (the arrangement of the 32 BChl a molecules) on kET are discussed based on these results, to reveal how the B915-RC complex accomplishes its energy transfer function with a large uphill energy of 290cm(-1).

  16. Isolation and structural determination of C8-vinyl-bacteriochlorophyll d from the bciA and bchU double mutant of the green sulfur bacterium Chlorobaculum tepidum.

    PubMed

    Harada, Jiro; Mizoguchi, Tadashi; Nomura, Kota; Tamiaki, Hitoshi

    2014-07-01

    The mutant lacking enzymes BciA and BchU, that catalyzed reduction of the C8-vinyl group and methylation at the C20 position of bacteriochlorophyll (BChl) c, respectively, in the green sulfur bacterium Chlorobaculum tepidum, were constructed. This mutant accumulated C8-vinyl-BChl d derivatives, and a molecular structure of the major pigment was fully characterized by its NMR, mass, and circular dichroism spectra, as well as by chemical modification: (3(1) R)-8-vinyl-12-ethyl-(R[V,E])BChl d was confirmed as a new BChl d species in the cells. In vitro chlorosome-like self-aggregates of this pigment were prepared in an aqueous micellar solution, and formed more rapidly than those of (3(1) R)-8,12-diethyl-(R[E,E])BChl d isolated from the green sulfur bacterium Chlorobaculum parvum NCIB8327d synthesizing BChl d homologs. Their red-shifted Q y absorption bands were almost the same at 761 nm, and the value was larger than those of in vitro self-aggregates of R[E,E]BChl c (737 nm) and R[V,E]BChl c (726 nm), while the monomeric states of the former gave Q y bands at shorter wavelengths than those of the latter. Red shifts by self-aggregation of the two BChl d species were estimated to be 110 nm and much larger than those by BChls c (75 nm for [E,E] and 64 nm for [V,E]).

  17. Biochemistry and control of the reductive tricarboxylic acid pathway of CO2 fixation and physiological role of the Rubis CO-like protein

    SciTech Connect

    Tabita, F. Robert

    2008-12-04

    During the past years of this project we have made progress relative to the two major goals of the proposal: (1) to study the biochemistry and regulation of the reductive TCA cycle of CO2 fixation and (2) to probe the physiological role of a RubisCO-like protein (RLP). Both studies primarily employ the green sulfur bacterium Chlorobium tepidum as well as other photosynthetic bacteria including Rhodospirillum rubrum and Rhodopseudomonas palustris.

  18. Influence of organics and silica on Fe(II) oxidation rates and cell-mineral aggregate formation by the green-sulfur Fe(II)-oxidizing bacterium Chlorobium ferrooxidans KoFox - Implications for Fe(II) oxidation in ancient oceans

    NASA Astrophysics Data System (ADS)

    Gauger, Tina; Byrne, James M.; Konhauser, Kurt O.; Obst, Martin; Crowe, Sean; Kappler, Andreas

    2016-06-01

    Most studies on microbial phototrophic Fe(II) oxidation (photoferrotrophy) have focused on purple bacteria, but recent evidence points to the importance of green-sulfur bacteria (GSB). Their recovery from modern ferruginous environments suggests that these photoferrotrophs can offer insights into how their ancient counterparts grew in Archean oceans at the time of banded iron formation (BIF) deposition. It is unknown, however, how Fe(II) oxidation rates, cell-mineral aggregate formation, and Fe-mineralogy vary under environmental conditions reminiscent of the geological past. To address this, we studied the Fe(II)-oxidizer Chlorobium ferrooxidans KoFox, a GSB living in co-culture with the heterotrophic Geospirillum strain KoFum. We investigated the mineralogy of Fe(III) metabolic products at low/high light intensity, and in the presence of dissolved silica and/or fumarate. Silica and fumarate influenced the crystallinity and particle size of the produced Fe(III) minerals. The presence of silica also enhanced Fe(II) oxidation rates, especially at high light intensities, potentially by lowering Fe(II)-toxicity to the cells. Electron microscopic imaging showed no encrustation of either KoFox or KoFum cells with Fe(III)-minerals, though weak associations were observed suggesting co-sedimentation of Fe(III) with at least some biomass via these aggregates, which could support diagenetic Fe(III)-reduction. Given that GSB are presumably one of the most ancient photosynthetic organisms, and pre-date cyanobacteria, our findings, on the one hand, strengthen arguments for photoferrotrophic activity as a likely mechanism for BIF deposition on a predominantly anoxic early Earth, but, on the other hand, also suggest that preservation of remnants of Fe(II)-oxidizing GSB as microfossils in the rock record is unlikely.

  19. Coherent Control Protocol for Separating Energy-Transfer Pathways in Photosynthetic Complexes by Chiral Multidimensional Signals†

    PubMed Central

    Abramavicius, Darius; Mukamel, Shaul

    2013-01-01

    Adaptive optimizations performed using a genetic algorithm are employed to construct optimal laser pulse configurations that separate spectroscopic features associated with the two main energy-transfer pathways in the third-order nonlinear optical response simulated for the Fenna–Matthews–Olson (FMO) photosynthetic complex from the green sulfur bacterium Chlorobium tepidum. Superpositions of chirality-induced tensor components in both collinear and noncollinear pulse configurations are analyzed. The optimal signals obtained by manipulating the ratios of various 2D spectral peaks reveal detailed information about the excitation dynamics. PMID:21495702

  20. Chirality-Based Signatures of Local Protein Environments in Two-Dimensional Optical Spectroscopy of Two Species Photosynthetic Complexes of Green Sulfur Bacteria: Simulation Study

    PubMed Central

    Voronine, Dmitri V.; Abramavicius, Darius; Mukamel, Shaul

    2008-01-01

    Two-dimensional electronic chirality-induced signals of excitons in the photosynthetic Fenna-Matthews-Olson complex from two species of green sulfur bacteria (Chlorobium tepidum and Prosthecochloris aestuarii) are compared. The spectra are predicted to provide sensitive probes of local protein environment of the constituent bacteriochlorophyll a chromophores and reflect electronic structure variations (site energies and couplings) of the two complexes. Pulse polarization configurations are designed that can separate the coherent and incoherent exciton dynamics contributions to the two-dimensional spectra. PMID:18676650

  1. Specific gene bciD for C7-methyl oxidation in bacteriochlorophyll e biosynthesis of brown-colored green sulfur bacteria.

    PubMed

    Harada, Jiro; Mizoguchi, Tadashi; Satoh, Souichirou; Tsukatani, Yusuke; Yokono, Makio; Noguchi, Masato; Tanaka, Ayumi; Tamiaki, Hitoshi

    2013-01-01

    The gene named bciD, which encodes the enzyme involved in C7-formylation in bacteriochlorophyll e biosynthesis, was found and investigated by insertional inactivation in the brown-colored green sulfur bacterium Chlorobaculum limnaeum (previously called Chlorobium phaeobacteroides). The bciD mutant cells were green in color, and accumulated bacteriochlorophyll c homologs bearing the 7-methyl group, compared to C7-formylated BChl e homologs in the wild type. BChl-c homolog compositions in the mutant were further different from those in Chlorobaculum tepidum which originally produced BChl c: (3(1) S)-8-isobutyl-12-ethyl-BChl c was unusually predominant.

  2. The Diversity of Sulfide Oxidation and Sulfate Reduction Genes Expressed by the Bacterial Communities of the Cariaco Basin, Venezuela

    PubMed Central

    Rodriguez-Mora, Maria J.; Edgcomb, Virginia P.; Taylor, Craig; Scranton, Mary I.; Taylor, Gordon T.; Chistoserdov, Andrei Y.

    2016-01-01

    Qualitative expression of dissimilative sulfite reductase (dsrA), a key gene in sulfate reduction, and sulfide:quinone oxidoreductase (sqr), a key gene in sulfide oxidation was investigated. Neither of the two could be amplified from mRNA retrieved with Niskin bottles but were amplified from mRNA retrieved by the Deep SID. The sqr and sqr-like genes retrieved from the Cariaco Basin were related to the sqr genes from a Bradyrhizobium sp., Methylomicrobium alcaliphilum, Sulfurovum sp. NBC37-1, Sulfurimonas autotrophica, Thiorhodospira sibirica and Chlorobium tepidum. The dsrA gene sequences obtained from the redoxcline of the Cariaco Basin belonged to chemoorganotrophic and chemoautotrophic sulfate and sulfur reducers belonging to the class Deltaproteobacteria (phylum Proteobacteria) and the order Clostridiales (phylum Firmicutes). PMID:27651847

  3. The Diversity of Sulfide Oxidation and Sulfate Reduction Genes Expressed by the Bacterial Communities of the Cariaco Basin, Venezuela.

    PubMed

    Rodriguez-Mora, Maria J; Edgcomb, Virginia P; Taylor, Craig; Scranton, Mary I; Taylor, Gordon T; Chistoserdov, Andrei Y

    2016-01-01

    Qualitative expression of dissimilative sulfite reductase (dsrA), a key gene in sulfate reduction, and sulfide:quinone oxidoreductase (sqr), a key gene in sulfide oxidation was investigated. Neither of the two could be amplified from mRNA retrieved with Niskin bottles but were amplified from mRNA retrieved by the Deep SID. The sqr and sqr-like genes retrieved from the Cariaco Basin were related to the sqr genes from a Bradyrhizobium sp., Methylomicrobium alcaliphilum, Sulfurovum sp. NBC37-1, Sulfurimonas autotrophica, Thiorhodospira sibirica and Chlorobium tepidum. The dsrA gene sequences obtained from the redoxcline of the Cariaco Basin belonged to chemoorganotrophic and chemoautotrophic sulfate and sulfur reducers belonging to the class Deltaproteobacteria (phylum Proteobacteria) and the order Clostridiales (phylum Firmicutes).

  4. Isorenieratene Biosynthesis in Green Sulfur Bacteria Requires the Cooperative Actions of Two Carotenoid Cyclases▿ †

    PubMed Central

    Maresca, Julia A.; Romberger, Steven P.; Bryant, Donald A.

    2008-01-01

    The cyclization of lycopene to γ- or β-carotene is a major branch point in the biosynthesis of carotenoids in photosynthetic bacteria. Four families of carotenoid cyclases are known, and each family includes both mono- and dicyclases, which catalyze the formation of γ- and β-carotene, respectively. Green sulfur bacteria (GSB) synthesize aromatic carotenoids, of which the most commonly occurring types are the monocyclic chlorobactene and the dicyclic isorenieratene. Recently, the cruA gene, encoding a conserved hypothetical protein found in the genomes of all GSB and some cyanobacteria, was identified as a lycopene cyclase. Further genomic analyses have found that all available fully sequenced genomes of GSB encode an ortholog of cruA. Additionally, the genomes of all isorenieratene-producing species of GSB encode a cruA paralog, now named cruB. The cruA gene from the chlorobactene-producing GSB species Chlorobaculum tepidum and both cruA and cruB from the brown-colored, isorenieratene-producing GSB species Chlorobium phaeobacteroides strain DSM 266T were heterologously expressed in lycopene- and neurosporene-producing strains of Escherichia coli, and the cruB gene of Chlorobium clathratiforme strain DSM 5477T was also heterologously expressed in C. tepidum by inserting the gene at the bchU locus. The results show that CruA is probably a lycopene monocyclase in all GSB and that CruB is a γ-carotene cyclase in isorenieratene-producing species. Consequently, the branch point for the synthesis of mono- and dicyclic carotenoids in GSB seems to be the modification of γ-carotene, rather than the cyclization of lycopene as occurs in cyanobacteria. PMID:18676669

  5. Dimensional comparison theory.

    PubMed

    Möller, Jens; Marsh, Herb W

    2013-07-01

    Although social comparison (Festinger, 1954) and temporal comparison (Albert, 1977) theories are well established, dimensional comparison is a largely neglected yet influential process in self-evaluation. Dimensional comparison entails a single individual comparing his or her ability in a (target) domain with his or her ability in a standard domain (e.g., "How good am I in math compared with English?"). This article reviews empirical findings from introspective, path-analytic, and experimental studies on dimensional comparisons, categorized into 3 groups according to whether they address the "why," "with what," or "with what effect" question. As the corresponding research shows, dimensional comparisons are made in everyday life situations. They impact on domain-specific self-evaluations of abilities in both domains: Dimensional comparisons reduce self-concept in the worse off domain and increase self-concept in the better off domain. The motivational basis for dimensional comparisons, their integration with recent social cognitive approaches, and the interdependence of dimensional, temporal, and social comparisons are discussed.

  6. Acquisition of Comparison Constructions

    ERIC Educational Resources Information Center

    Hohaus, Vera; Tiemann, Sonja; Beck, Sigrid

    2014-01-01

    This article presents a study on the time course of the acquisition of comparison constructions. The order in which comparison constructions (comparatives, measure phrases, superlatives, degree questions, etc.) show up in English- and German-learning children's spontaneous speech is quite fixed. It is shown to be insufficiently determined by…

  7. Characterization of an FMO Variant of Chlorobaculum tepidum Carrying Bacteriochlorophyll a Esterified by Geranylgeraniol

    SciTech Connect

    Wen, Jianzhong; Harada, Jiro; Buyle, Kenny; Yuan, Kevin; Tamiaki, Hitoshi; Oh-oka, Hirozo; Loomis, Richard A; Blankenship, R. E.

    2010-06-15

    The Fenna-Matthews-Olson light-harvesting antenna (FMO) protein has been a model system for understanding pigment-protein interactions in the energy transfer process in photosynthesis. All previous studies have utilized wild-type FMO proteins from several species. Here we report the purification and characterization of the first FMO protein variant generated via replacement of the esterifying alcohol at the C-17 propionate residue of bacteriochlorophyll (BChl) a, phytol, with geranylgeraniol, which possesses three more double bonds. The FMO protein still assembles with the modified pigment, but both the whole cell absorption and the biochemical purification indicate that the mutant cells contain a much less mature FMO protein. The gene expression was checked using qRT-PCR, and none of the genes encoding BChl a-binding proteins are strongly regulated at the transcriptional level. The smaller amount of the FMO protein in the mutant cell is probably due to the degradation of the apo-FMO protein at different stages after it does not bind the normal pigment. The absorption, fluorescence, and CD spectra of the purified FMO variant protein are similar to those of the wild-type FMO protein except the conformations of most pigments are more heterogeneous, which broadens the spectral bands. Interestingly, the lowest-energy pigment binding site seems to be unchanged and is the only peak that can be well resolved in 77 K absorption spectra. The excited-state lifetime of the variant FMO protein is unchanged from that of the wild type and shows a temperature-dependent modulation similar to that of the wild type. The variant FMO protein is less thermally stable than the wild type. The assembly of the FMO protein and also the implications of the decreased FMO/chlorosome stoichiometry are discussed in terms of the topology of these two antennas on the cytoplasmic membrane.

  8. Uncertainty and Social Comparison

    ERIC Educational Resources Information Center

    Gruder, Charles L.; And Others

    1975-01-01

    The purpose of the present research was to determine how experimental manipulations of certainty would affect social comparison choices in the paradigm used by Wheeler et al. (1969) and Gruder (1971). (Author)

  9. Theoretical Simulations and Ultrafast Pump-probe Spectroscopy Experiments in Pigment-protein Photosynthetic Complexes

    SciTech Connect

    Buck, D. R.

    2000-09-12

    Theoretical simulations and ultrafast pump-probe laser spectroscopy experiments were used to study photosynthetic pigment-protein complexes and antennae found in green sulfur bacteria such as Prosthecochloris aestuarii, Chloroflexus aurantiacus, and Chlorobium tepidum. The work focused on understanding structure-function relationships in energy transfer processes in these complexes through experiments and trying to model that data as we tested our theoretical assumptions with calculations. Theoretical exciton calculations on tubular pigment aggregates yield electronic absorption spectra that are superimpositions of linear J-aggregate spectra. The electronic spectroscopy of BChl c/d/e antennae in light harvesting chlorosomes from Chloroflexus aurantiacus differs considerably from J-aggregate spectra. Strong symmetry breaking is needed if we hope to simulate the absorption spectra of the BChl c antenna. The theory for simulating absorption difference spectra in strongly coupled photosynthetic antenna is described, first for a relatively simple heterodimer, then for the general N-pigment system. The theory is applied to the Fenna-Matthews-Olson (FMO) BChl a protein trimers from Prosthecochloris aestuarii and then compared with experimental low-temperature absorption difference spectra of FMO trimers from Chlorobium tepidum. Circular dichroism spectra of the FMO trimer are unusually sensitive to diagonal energy disorder. Substantial differences occur between CD spectra in exciton simulations performed with and without realistic inhomogeneous distribution functions for the input pigment diagonal energies. Anisotropic absorption difference spectroscopy measurements are less consistent with 21-pigment trimer simulations than 7-pigment monomer simulations which assume that the laser-prepared states are localized within a subunit of the trimer. Experimental anisotropies from real samples likely arise from statistical averaging over states with diagonal energies shifted by

  10. Redox regulation of energy transfer efficiency in antennas of green photosynthetic bacteria

    NASA Technical Reports Server (NTRS)

    Blankenship, R. E.; Cheng, P.; Causgrove, T. P.; Brune, D. C.; Wang, J.

    1993-01-01

    The efficiency of energy transfer from the peripheral chlorosome antenna structure to the membrane-bound antenna in green sulfur bacteria depends strongly on the redox potential of the medium. The fluorescence spectra and lifetimes indicate that efficient quenching pathways are induced in the chlorosome at high redox potential. The midpoint redox potential for the induction of this effect in isolated chlorosomes from Chlorobium vibrioforme is -146 mV at pH 7 (vs the normal hydrogen electrode), and the observed midpoint potential (n = 1) decreases by 60 mV per pH unit over the pH range 7-10. Extraction of isolated chlorosomes with hexane has little effect on the redox-induced quenching, indicating that the component(s) responsible for this effect are bound and not readily extractable. We have purified and partially characterized the trimeric water-soluble bacteriochlorophyll a-containing protein from the thermophilic green sulfur bacterium Chlorobium tepidum. This protein is located between the chlorosome and the membrane. Fluorescence spectra of the purified protein indicate that it also contains groups that quench excitations at high redox potential. The results indicate that the energy transfer pathway in green sulfur bacteria is regulated by redox potential. This regulation appears to operate in at least two distinct places in the energy transfer pathway, the oligomeric pigments in the interior of the chlorosome and in the bacteriochlorophyll a protein. The regulatory effect may serve to protect the cell against superoxide-induced damage when oxygen is present. By quenching excitations before they reach the reaction center, reduction and subsequent autooxidation of the low potential electron acceptors found in these organisms is avoided.

  11. Modelling the bacterial photosynthetic reaction center. V. Assignment of the electronic transition observed at 2200 cm-1 in the special-pair radical-cation as a second-highest occupied molecular orbital to highest occupied molecular orbital transition

    NASA Astrophysics Data System (ADS)

    Reimers, Jeffrey R.; Shapley, Warwick A.; Hush, Noel S.

    2003-08-01

    Primary charge separation in photoexcited photosynthetic reaction centers produces the radical cation P+ of a bacteriochlorophyll dimer known as the special-pair P. P+ has an intense electronic transition in the vicinity of 1800-5000 cm-1 which is usually assigned to the interchromophore hole-transfer excitation of the dimer radical cation; in principle, this spectrum can give much insight into key steps of the solar-to-electrical energy-conversion process. The extent to which this transition is localized on one-half of the dimer or delocalized over both is of utmost importance; an authoritative deduction of this quantity from purely spectroscopic arguments requires the detailed assignment of the observed high to medium resolution spectra. For reaction centers containing bacteriochlorophylls a or b, a shoulder is observed at 2200 cm-1 on the low-energy side of the main hole-transfer absorption band, a band whose maximum is near 2700 cm-1. Before quantitative analysis of the hole-transfer absorption in these well-studied systems can be attempted, the nature of the processes leading to this shoulder must be determined. We interpret it as arising from an intrachromophore SHOMO to HOMO transition whose intensity arises wholly through vibronic coupling with the hole-transfer band. A range of ab initio and density-functional calculations are performed to estimate the energy of this transition both for monomeric cations and for P+ of Blastochloris viridis, Rhodobacter sphaeroides, Chlorobium limicola, Chlorobium tepidum, Chlamydomonas reinhardtii, Synochocystis S.6803, spinach photosystems I and II, Heliobacillus mobilis, and finally Heliobacterium modesticaldum, with the results found to qualitatively describe the available experimental data. Subsequent papers in this series provide quantitative analyses of the vibronic coupling and complete spectral simulations based on the model developed herein.

  12. Model comparison in ANOVA.

    PubMed

    Rouder, Jeffrey N; Engelhardt, Christopher R; McCabe, Simon; Morey, Richard D

    2016-12-01

    Analysis of variance (ANOVA), the workhorse analysis of experimental designs, consists of F-tests of main effects and interactions. Yet, testing, including traditional ANOVA, has been recently critiqued on a number of theoretical and practical grounds. In light of these critiques, model comparison and model selection serve as an attractive alternative. Model comparison differs from testing in that one can support a null or nested model vis-a-vis a more general alternative by penalizing more flexible models. We argue this ability to support more simple models allows for more nuanced theoretical conclusions than provided by traditional ANOVA F-tests. We provide a model comparison strategy and show how ANOVA models may be reparameterized to better address substantive questions in data analysis.

  13. MCNP and GADRAS Comparisons

    SciTech Connect

    Klasky, Marc Louis; Myers, Steven Charles; James, Michael R.; Mayo, Douglas R.

    2016-04-19

    To facilitate the timely execution of System Threat Reviews (STRs) for DNDO, and also to develop a methodology for performing STRs, LANL performed comparisons of several radiation transport codes (MCNP, GADRAS, and Gamma-Designer) that have been previously utilized to compute radiation signatures. While each of these codes has strengths, it is of paramount interest to determine the limitations of each of the respective codes and also to identify the most time efficient means by which to produce computational results, given the large number of parametric cases that are anticipated in performing STR's. These comparisons serve to identify regions of applicability for each code and provide estimates of uncertainty that may be anticipated. Furthermore, while performing these comparisons, examination of the sensitivity of the results to modeling assumptions was also examined. These investigations serve to enable the creation of the LANL methodology for performing STRs. Given the wide variety of radiation test sources, scenarios, and detectors, LANL calculated comparisons of the following parameters: decay data, multiplicity, device (n,γ) leakages, and radiation transport through representative scenes and shielding. This investigation was performed to understand potential limitations utilizing specific codes for different aspects of the STR challenges.

  14. Comparison of Nursing Roles.

    ERIC Educational Resources Information Center

    Macdonough, Georgia P.

    2001-01-01

    This 1972 paper presents 12 comparisons of the nurse's role in the school versus in the hospital. For example, in the hospital, patients know they are ill and want to get well, while in school patients may not recognize that they need help. In the hospital, the nurse's workload is determined for her, while in school, it is self-determined. (SM)

  15. Fall 2013 International Comparisons

    ERIC Educational Resources Information Center

    Northwest Evaluation Association, 2014

    2014-01-01

    This Fall report is an aggregated statistical analysis of Measures of Academic Progress® (MAP®) data from international schools. The report provides a consistent means of comparisons of specific sub-groups by subject and grade, which allows partners to compare their MAP® results with other schools within their region or membership organization.…

  16. On molecular graph comparison.

    PubMed

    Melo, Jenny A; Daza, Edgar

    2011-06-01

    Since the last half of the nineteenth century, molecular graphs have been present in several branches of chemistry. When used for molecular structure representation, they have been compared after mapping the corresponding graphs into mathematical objects. However, direct molecular comparison of molecular graphs is a research field less explored. The goal of this mini-review is to show some distance and similarity coefficients which were proposed to directly compare molecular graphs or which could be useful to do so.

  17. Retained gas inventory comparison

    SciTech Connect

    BARTON, W.B.

    1999-05-18

    Gas volume data derived from four different analytical methods were collected and analyzed for comparison to volumes originally used in the technical basis for the Basis for Interim Operations (BIO). The original volumes came from Hodgson (1996) listed in the reference section of this document. Hodgson (1996) screened all 177 single and double-shell tanks for the presence of trapped gas in waste via two analytical methods: Surface Level Rise (SLR), and Barometric Pressure Effect (BPE). More recent gas volume projections have been calculated using different analytical techniques along with updates to the parameters used as input to the SLR and BPE models. Gas volumes derived from new analytical instruments include those as measured by the Void Fraction Instrument (VFI) and Retained Gas Sampler (RGS). The results of this comparison demonstrate that the original retained gas volumes of Hodgson (1996) used as a technical basis in developing the BIO were conservative, and were conservative from a safety analysis standpoint. These results represent only comparisons to the original reported volumes using the limited set of newly acquired data that is available.

  18. NTP comparison process

    NASA Astrophysics Data System (ADS)

    Corban, Robert

    The systems engineering process for the concept definition phase of the program involves requirements definition, system definition, and consistent concept definition. The requirements definition process involves obtaining a complete understanding of the system requirements based on customer needs, mission scenarios, and nuclear thermal propulsion (NTP) operating characteristics. A system functional analysis is performed to provide a comprehensive traceability and verification of top-level requirements down to detailed system specifications and provides significant insight into the measures of system effectiveness to be utilized in system evaluation. The second key element in the process is the definition of system concepts to meet the requirements. This part of the process involves engine system and reactor contractor teams to develop alternative NTP system concepts that can be evaluated against specific attributes, as well as a reference configuration against which to compare system benefits and merits. Quality function deployment (QFD), as an excellent tool within Total Quality Management (TQM) techniques, can provide the required structure and provide a link to the voice of the customer in establishing critical system qualities and their relationships. The third element of the process is the consistent performance comparison. The comparison process involves validating developed concept data and quantifying system merits through analysis, computer modeling, simulation, and rapid prototyping of the proposed high risk NTP subsystems. The maximum amount possible of quantitative data will be developed and/or validated to be utilized in the QFD evaluation matrix. If upon evaluation of a new concept or its associated subsystems determine to have substantial merit, those features will be incorporated into the reference configuration for subsequent system definition and comparison efforts.

  19. NTP comparison process

    NASA Technical Reports Server (NTRS)

    Corban, Robert

    1993-01-01

    The systems engineering process for the concept definition phase of the program involves requirements definition, system definition, and consistent concept definition. The requirements definition process involves obtaining a complete understanding of the system requirements based on customer needs, mission scenarios, and nuclear thermal propulsion (NTP) operating characteristics. A system functional analysis is performed to provide a comprehensive traceability and verification of top-level requirements down to detailed system specifications and provides significant insight into the measures of system effectiveness to be utilized in system evaluation. The second key element in the process is the definition of system concepts to meet the requirements. This part of the process involves engine system and reactor contractor teams to develop alternative NTP system concepts that can be evaluated against specific attributes, as well as a reference configuration against which to compare system benefits and merits. Quality function deployment (QFD), as an excellent tool within Total Quality Management (TQM) techniques, can provide the required structure and provide a link to the voice of the customer in establishing critical system qualities and their relationships. The third element of the process is the consistent performance comparison. The comparison process involves validating developed concept data and quantifying system merits through analysis, computer modeling, simulation, and rapid prototyping of the proposed high risk NTP subsystems. The maximum amount possible of quantitative data will be developed and/or validated to be utilized in the QFD evaluation matrix. If upon evaluation of a new concept or its associated subsystems determine to have substantial merit, those features will be incorporated into the reference configuration for subsequent system definition and comparison efforts.

  20. MACPEX Water Measurement Comparison

    NASA Astrophysics Data System (ADS)

    Al-Saadi, J. A.; Thornhill, A.; Alston, E. J.; Chen, G.; Fahey, D. W.; Jensen, E. J.; Mace, G. G.

    2012-12-01

    The Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) airborne field campaign was conducted in March and April 2011 to investigate cirrus cloud properties and the processes that affect their impact on radiation. In pursuit of this goal the NASA WB-57 was outfitted with dozens of in-situ instruments from government and university science teams including a wide range of water instruments. This provided an unprecedented situation to compare eight water instruments on one platform measuring water vapor (CIMS, DLH, HWV, JLH, and ULH), total water (ALIAS and FISH) and ice water content (CLH/IWC) for 14 flight days. Objective and data-driven approaches were applied to analyze the comparison data and to assess the consistency levels between the instruments and instrument uncertainties. The analysis is primarily focused on the upper tropospheric and lower stratospheric conditions, paying particular attention to water levels below 20 ppmv and between 20 - 120 ppmv depending on specific instrument data coverage. To be presented are comparison results suggesting the level of the agreement among the instrument as a function of atmospheric conditions, e.g., temperature and water vapor. Also discussed are some exploratory analyses of instrument precisions.

  1. Photoreduction and reoxidation of the three iron-sulfur clusters of reaction centers of green sulfur bacteria.

    PubMed

    Sétif, P; Seo, D; Sakurai, H

    2001-09-01

    Iron-sulfur clusters are the terminal electron acceptors of the photosynthetic reaction centers of green sulfur bacteria and photosystem I. We have studied electron-transfer reactions involving these clusters in the green sulfur bacterium Chlorobium tepidum, using flash-absorption spectroscopic measurements. We show for the first time that three different clusters, named F(X), F(1), and F(2), can be photoreduced at room temperature during a series of consecutive flashes. The rates of electron escape to exogenous acceptors depend strongly upon the number of reduced clusters. When two or three clusters are reduced, the escape is biphasic, with the fastest phase being 12-14-fold faster than the slowest phase, which is similar to that observed after single reduction. This is explained by assuming that escape involves mostly the second reducible cluster. Evidence is thus provided for a functional asymmetry between the two terminal acceptors F(1) and F(2). From multiple-flash experiments, it was possible to derive the intrinsic recombination rates between P840(+) and reduced iron-sulfur clusters: values of 7, 14, and 59 s(-1) were found after one, two and three electron reduction of the clusters, respectively. The implications of our results for the relative redox potentials of the three clusters are discussed.

  2. Unravelling coherent dynamics and energy dissipation in photosynthetic complexes by 2D spectroscopy.

    PubMed

    Abramavicius, Darius; Voronine, Dmitri V; Mukamel, Shaul

    2008-05-01

    Spectroscopic studies of light harvesting and the subsequent energy conversion in photosynthesis can track quantum dynamics happening on the microscopic level. The Fenna-Matthews-Olson complex of the photosynthetic green sulfur bacteria Chlorobium tepidum is a prototype efficient light-harvesting antenna: it stores the captured photon energy in the form of excitons (collective excitations), which are subsequently converted to chemical energy with almost 100% efficiency. These excitons show an elaborate relaxation pattern involving coherent and incoherent pathways. We make use of the complex chirality and fundamental symmetries of multidimensional optical signals to design new sequences of ultrashort laser pulses that can distinguish between coherent quantum oscillations and incoherent energy dissipation during the exciton relaxation. The cooperative dynamical features, which reflect the coherent nature of excitations, are amplified. The extent of quantum oscillations and their timescales in photosynthesis can be readily extracted from the designed signals, showing that cooperativity is maintained during energy transport in the Fenna-Matthews-Olson complex. The proposed pulse sequences may also be applied to reveal information on the robustness of quantum states in the presence of fluctuating environments in other nanoscopic complexes and devices.

  3. Prediction of the repeat domain structures and impact of parkinsonism-associated variations on structure and function of all functional domains of leucine-rich repeat kinase 2 (LRRK2).

    PubMed

    Mills, Ryan D; Mulhern, Terrence D; Liu, Fei; Culvenor, Janetta G; Cheng, Heung-Chin

    2014-04-01

    Genetic variations of leucine-rich repeat kinase 2 (LRRK2) are the major cause of dominantly inherited Parkinson disease (PD). LRRK2 protein contains seven predicted domains: a tandem Ras-like GTPase (ROC) domain and C-terminal of Roc (COR) domain, a protein kinase domain, and four repeat domains. PD-causative variations arise in all domains, suggesting that aberrant functioning of any domain can contribute to neurotoxic mechanisms of LRRK2. Determination of the three-dimensional structure of LRRK2 is one of the best avenues to decipher its neurotoxic mechanism. However, with the exception of the Roc domain, the three-dimensional structures of the functional domains of LRRK2 have yet to be determined. Based on the known three-dimensional structures of repeat domains of other proteins, the tandem Roc-COR domains of the Chlorobium tepidum Rab family protein, and the kinase domain of the Dictyostelium discoideum Roco4 protein, we predicted (1) the motifs essential for protein-protein interactions in all domains, (2) the motifs critical for catalysis and substrate recognition in the tandem Roc-COR and kinase domains, and (3) the effects of some PD-associated missense variations on the neurotoxic action of LRRK2. Results of our analysis provide a conceptual framework for future investigation into the regulation and the neurotoxic mechanism of LRRK2.

  4. Nonphotochemical Hole-Burning Studies of Energy Transfer Dynamics in Antenna Complexes of Photosynthetic Bacteria

    SciTech Connect

    Matsuzaki, Satoshi

    2001-01-01

    This thesis contains the candidate's original work on excitonic structure and energy transfer dynamics of two bacterial antenna complexes as studied using spectral hole-burning spectroscopy. The general introduction is divided into two chapters (1 and 2). Chapter 1 provides background material on photosynthesis and bacterial antenna complexes with emphasis on the two bacterial antenna systems related to the thesis research. Chapter 2 reviews the underlying principles and mechanism of persistent nonphotochemical hole-burning (NPHB) spectroscopy. Relevant energy transfer theories are also discussed. Chapters 3 and 4 are papers by the candidate that have been published. Chapter 3 describes the application of NPHB spectroscopy to the Fenna-Matthews-Olson (FMO) complex from the green sulfur bacterium Prosthecochloris aestuarii; emphasis is on determination of the low energy vibrational structure that is important for understanding the energy transfer process associated within three lowest energy Qy-states of the complex. The results are compared with those obtained earlier on the FMO complex from Chlorobium tepidum. In Chapter 4, the energy transfer dynamics of the B800 molecules of intact LH2 and B800-deficient LH2 complexes of the purple bacterium Rhodopseudomonas acidophila are compared. New insights on the additional decay channel of the B800 ring of bacteriochlorophyll a (BChl a) molecules are provided. General conclusions are given in Chapter 5.

  5. Unravelling Coherent Dynamics and Energy Dissipation in Photosynthetic Complexes by 2D Spectroscopy

    PubMed Central

    Abramavicius, Darius; Voronine, Dmitri V.; Mukamel, Shaul

    2008-01-01

    Spectroscopic studies of light harvesting and the subsequent energy conversion in photosynthesis can track quantum dynamics happening on the microscopic level. The Fenna-Matthews-Olson complex of the photosynthetic green sulfur bacteria Chlorobium tepidum is a prototype efficient light-harvesting antenna: it stores the captured photon energy in the form of excitons (collective excitations), which are subsequently converted to chemical energy with almost 100% efficiency. These excitons show an elaborate relaxation pattern involving coherent and incoherent pathways. We make use of the complex chirality and fundamental symmetries of multidimensional optical signals to design new sequences of ultrashort laser pulses that can distinguish between coherent quantum oscillations and incoherent energy dissipation during the exciton relaxation. The cooperative dynamical features, which reflect the coherent nature of excitations, are amplified. The extent of quantum oscillations and their timescales in photosynthesis can be readily extracted from the designed signals, showing that cooperativity is maintained during energy transport in the Fenna-Matthews-Olson complex. The proposed pulse sequences may also be applied to reveal information on the robustness of quantum states in the presence of fluctuating environments in other nanoscopic complexes and devices. PMID:18192357

  6. Notes on the Comparison Class

    NASA Astrophysics Data System (ADS)

    Solt, Stephanie

    This paper investigates the role of comparison classes in the semantics of gradable adjectives in the positive form, focusing on the case where the comparison class is expressed overtly via a for-phrase (e.g. John is tall for a jockey). Two central questions are addressed: what information does the comparison class provide, and how is this information integrated compositionally? It is shown that the standard of comparison invoked by the positive form can be analyzed as a range of values whose width is based on the degree of dispersion in the comparison class. Compositionally, the comparison class can be analyzed as an argument of a null positive morpheme (contra Kennedy [13]), in parallel to recent proposals for the superlative (e.g. Heim [9]). The implications of the analysis for the choice between degree- and delineation-based analyses of gradable adjectives are discussed.

  7. Long History of IAM Comparisons

    SciTech Connect

    Smith, Steven J.; Clarke, Leon E.; Edmonds, James A.; Kejun, Jiang; Kriegler, Elmar; Masui, Toshihiko; Riahi, Keywan; Shukla, Priyadarshi R.; Tavoni, Massimo; Van Vuuren, Detlef; Weyant, John

    2015-04-23

    Correspondence to editor: We agree with the editors that the assumptions behind models of all types, including integrated assessment models (IAMs), should be as transparent as possible. The editors were in error, however, when they implied that the IAM community is just “now emulating the efforts of climate researchers by instigating their own model inter-comparison projects (MIPs).” In fact, model comparisons for integrated assessment and climate models followed a remarkably similar trajectory. Early General Circulation Model (GCM) comparison efforts, evolved to the first Atmospheric Model Inter-comparison Project (AMIP), which was initiated in the early 1990s. Atmospheric models evolved to coupled atmosphere-ocean models (AOGCMs) and results from the first Coupled Model Inter-Comparison Project (CMIP1) become available about a decade later. Results of first energy model comparison exercise, conducted under the auspices of the Stanford Energy Modeling Forum, were published in 1977. A summary of the first comparison focused on climate change was published in 1993. As energy models were coupled to simple economic and climate models to form IAMs, the first comparison exercise for IAMs (EMF-14) was initiated in 1994, and IAM comparison exercises have been on-going since this time.

  8. Glovebox decontamination technology comparison

    SciTech Connect

    Quintana, D.M.; Rodriguez, J.B.; Cournoyer, M.E.

    1999-09-26

    Reconfiguration of the CMR Building and TA-55 Plutonium Facility for mission requirements will require the disposal or recycle of 200--300 gloveboxes or open front hoods. These gloveboxes and open front hoods must be decontaminated to meet discharge limits for Low Level Waste. Gloveboxes and open front hoods at CMR have been painted. One of the deliverables on this project is to identify the best method for stripping the paint from large numbers of gloveboxes. Four methods being considered are the following: conventional paint stripping, dry ice pellets, strippable coatings, and high pressure water technology. The advantages of each technology will be discussed. Last, cost comparisons between the technologies will be presented.

  9. Geology orbiter comparison study

    NASA Technical Reports Server (NTRS)

    Cutts, J. A. J.; Blasius, K. R.; Davis, D. R.; Pang, K. D.; Shreve, D. C.

    1977-01-01

    Instrument requirements of planetary geology orbiters were examined with the objective of determining the feasibility of applying standard instrument designs to a host of terrestrial targets. Within the basic discipline area of geochemistry, gamma-ray, X-ray fluorescence, and atomic spectroscopy remote sensing techniques were considered. Within the discipline area of geophysics, the complementary techniques of gravimetry and radar were studied. Experiments using these techniques were analyzed for comparison at the Moon, Mercury, Mars and the Galilean satellites. On the basis of these comparative assessments, the adaptability of each sensing technique was judged as a basic technique for many targets, as a single instrument applied to many targets, as a single instrument used in different mission modes, and as an instrument capability for nongeoscience objectives.

  10. Learning a Network of Comparisons

    ERIC Educational Resources Information Center

    Moeser, Shannon D.; Tarrant, Barbara L.

    1977-01-01

    Using a network of comparisons, B. Hayes-Roth and F. Hayes-Roth found that subjects performed better on adjacent than on nonadjacent comparisons. Results suggested that such networks are processed in a manner fundamentally different from simple linear arrays. Here subjects were required to learn a similar knowledge structure. These results…

  11. Social Comparison Processes in Organizations

    ERIC Educational Resources Information Center

    Greenberg, Jerald; Ashton-James, Claire E.; Ashkanasy, Neal M.

    2007-01-01

    We systematically analyze the role of social comparison processes in organizations. Specifically, we describe how social comparison processes have been used to explain six key areas of organizational inquiry: (1) organizational justice, (2) performance appraisal, (3) virtual work environments, (4) affective behavior in the workplace, (5) stress,…

  12. Social Comparison in the Classroom: A Review

    ERIC Educational Resources Information Center

    Dijkstra, Pieternel; Kuyper, Hans; van der Werf, Greetje; Buunk, Abraham P.; van der Zee, Yvonne G.

    2008-01-01

    This article reviews research conducted on social comparison processes in the classroom since Festinger proposed his theory of social comparison. It covers the theoretical framework of social comparison theory, and it is organized around the following themes: motives for social comparison, dimensions of social comparison, direction of social…

  13. [Anemia: guidelines comparison].

    PubMed

    Del Vecchio, Lucia

    2009-01-01

    The development of recombinant human erythropoietin and its introduction into the market in the late 1980s has significantly improved the quality of life of patients with chronic kidney disease (CKD) and reduced the need for blood transfusions. Starting from a cautious target, a progressive increase in the recommended hemoglobin levels has been observed over the years, in parallel with an increase in the obtained levels. This trend has gone together with the publication of findings of observational studies showing a relationship between the increase in hemoglobin levels and a reduction in the mortality risk, with the conduction of clinical trials testing the effects of complete anemia correction, and with the compilation of guidelines on anemia control in CKD patients by scientific societies and organizations. In the last two years, evidence of a possible increase in the mortality risk in those patients who were randomized to high hemoglobin levels has resulted in a decrease in the upper limit of the recommended Hb target to be obtained with erythropoietin stimulating agents (ESA), and consequently in a narrowing of the target range. Comparison of guidelines on anemia control in CKD patients is an interesting starting point to discuss single recommendations, strengthen their importance, or suggest new topics of research to fill up important gaps in knowledge.

  14. Data storage technology comparisons

    NASA Technical Reports Server (NTRS)

    Katti, Romney R.

    1990-01-01

    The role of data storage and data storage technology is an integral, though conceptually often underestimated, portion of data processing technology. Data storage is important in the mass storage mode in which generated data is buffered for later use. But data storage technology is also important in the data flow mode when data are manipulated and hence required to flow between databases, datasets and processors. This latter mode is commonly associated with memory hierarchies which support computation. VLSI devices can reasonably be defined as electronic circuit devices such as channel and control electronics as well as highly integrated, solid-state devices that are fabricated using thin film deposition technology. VLSI devices in both capacities play an important role in data storage technology. In addition to random access memories (RAM), read-only memories (ROM), and other silicon-based variations such as PROM's, EPROM's, and EEPROM's, integrated devices find their way into a variety of memory technologies which offer significant performance advantages. These memory technologies include magnetic tape, magnetic disk, magneto-optic disk, and vertical Bloch line memory. In this paper, some comparison between selected technologies will be made to demonstrate why more than one memory technology exists today, based for example on access time and storage density at the active bit and system levels.

  15. {sup 129}I interlaboratory comparison

    SciTech Connect

    Roberts, M.L.; Caffee, M.W.; Proctor, L.D.

    1996-05-01

    An interlaboratory comparison exercise for {sup 129}I has been organized and conducted. A total of seven laboratories participated in the exercise to either a full or limited extent. In the comparison, a suite of 11 samples were used. This suite of standards contained both synthetic `standard type` materials(i.e., AgI) and environmental materials. The isotopic {sup 129}I/{sup 127}I ratio of the samples varied from 10{sup -8} to 10{sup -14}. Preliminary results of the comparison are presented.

  16. Comparison of Artificial Compressibility Methods

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Housman, Jeffrey; Kwak, Dochan

    2004-01-01

    Various artificial compressibility methods for calculating the three-dimensional incompressible Navier-Stokes equations are compared. Each method is described and numerical solutions to test problems are conducted. A comparison based on convergence behavior, accuracy, and robustness is given.

  17. Large-Scale Sequence Comparison.

    PubMed

    Lal, Devi; Verma, Mansi

    2017-01-01

    There are millions of sequences deposited in genomic databases, and it is an important task to categorize them according to their structural and functional roles. Sequence comparison is a prerequisite for proper categorization of both DNA and protein sequences, and helps in assigning a putative or hypothetical structure and function to a given sequence. There are various methods available for comparing sequences, alignment being first and foremost for sequences with a small number of base pairs as well as for large-scale genome comparison. Various tools are available for performing pairwise large sequence comparison. The best known tools either perform global alignment or generate local alignments between the two sequences. In this chapter we first provide basic information regarding sequence comparison. This is followed by the description of the PAM and BLOSUM matrices that form the basis of sequence comparison. We also give a practical overview of currently available methods such as BLAST and FASTA, followed by a description and overview of tools available for genome comparison including LAGAN, MumMER, BLASTZ, and AVID.

  18. Jupiter Stratospheric Haze Comparison

    NASA Technical Reports Server (NTRS)

    1996-01-01

    These two views of Jupiter obtained by the imaging system aboard the Galileo spacecraft show evidence of strikingly different stratospheric hazes between the polar regions and low or mid latitudes. The Great Red Spot shows in one mosaic, centered at about 20 degrees South latitude and taken on June 26, 1996 at a range of 1.46 million kilometers. The other mosaic is centered near 50 degrees North latitude, and was taken on November 4, 1996 at a range of 1.60 million kilometers.

    North is at the top in both images. In the Red Spot image, the edge of the planet (limb) runs in a single arc from lower left to upper right, with dark space at lower right. In the polar image, the limb runs in two segments across the top right corner, with dark space at top right. Both images are mosaics; the offset of the individual frames of the mosaic produces the jagged border and the break in the polar limb.

    These are false color images, constructed specifically to reveal cloud elevation differences. Three color channels are used. The red channel is an image taken at a near infrared wavelength where methane in Jupiter's atmosphere is strongly absorbing, and therefore gives no information about deep clouds but reveals high clouds. The green channel is a weaker methane band, and the blue channel is assigned to a wavelength where Jupiter's atmosphere is transparent. Thus red features indicate high hazes. A view near the edge of the planet accentuates the high hazes because of the slanting path of the line of sight.

    The pronounced reddening near the edge of the planet in polar regions indicates a high stratospheric haze. Comparison with the Great Red Spot shows that such a high haze is absent at that latitude. Detailed analysis shows that a stratospheric haze exists at both latitudes but is approximately 50 km higher near the poles. It is likely that the high polar haze is produced by magnetospheric particles, which travel along magnetic field lines and bombard the upper atmosphere

  19. Protein Structure Comparison and Classification

    NASA Astrophysics Data System (ADS)

    Çamoǧlu, Orhan; Singh, Ambuj K.

    The success of genome projects has generated an enormous amount of sequence data. In order to realize the full value of the data, we need to understand its functional role and its evolutionary origin. Sequence comparison methods are incredibly valuable for this task. However, for sequences falling in the twilight zone (usually between 20 and 35% sequence similarity), we need to resort to structural alignment and comparison for a meaningful analysis. Such a structural approach can be used for classification of proteins, isolation of structural motifs, and discovery of drug targets.

  20. NCSL National Measurement Interlaboratory Comparison Database requirements

    SciTech Connect

    WHEELER,JAMES C.; PETTIT,RICHARD B.

    2000-04-20

    With the recent development of an International Comparisons Database which provides worldwide access to measurement comparison data between National Measurement Institutes, there is currently renewed interest in developing a database of comparisons for calibration laboratories within a country. For many years, the National Conference of Standards Laboratories (NCSL), through the Measurement Comparison Programs Committee, has sponsored Interlaboratory Comparisons in a variety of measurement areas. This paper will discuss the need for such a National database which catalogues and maintains Interlaboratory Comparisons data. The paper will also discuss future requirements in this area.

  1. Matrixed business support comparison study.

    SciTech Connect

    Parsons, Josh D.

    2004-11-01

    The Matrixed Business Support Comparison Study reviewed the current matrixed Chief Financial Officer (CFO) division staff models at Sandia National Laboratories. There were two primary drivers of this analysis: (1) the increasing number of financial staff matrixed to mission customers and (2) the desire to further understand the matrix process and the opportunities and challenges it creates.

  2. A comparison of five benchmarks

    NASA Technical Reports Server (NTRS)

    Huss, Janice E.; Pennline, James A.

    1987-01-01

    Five benchmark programs were obtained and run on the NASA Lewis CRAY X-MP/24. A comparison was made between the programs codes and between the methods for calculating performance figures. Several multitasking jobs were run to gain experience in how parallel performance is measured.

  3. International Comparisons and Educational Reform.

    ERIC Educational Resources Information Center

    Purves, Alan C., Ed.

    Increasingly over the past decade there have appeared in the press bar graphs comparing the performance of U.S. students with their counterparts in other countries. Usually these graphs have been accompanied by dire warnings and pointing fingers. The main source of the data on international comparisons has been the International Association for…

  4. Educational Comparisons and the Educator.

    ERIC Educational Resources Information Center

    Simkin, Keith

    This paper examines how educational comparisons might be used by the educational practitioners, and how the educator can contribute to the comparativists' work. Currently, it is argued, a gap exists between comparative educational study and the theory and practice of education. This leads to three areas of need. First, professional comparativists…

  5. Inhibition in Dot Comparison Tasks

    ERIC Educational Resources Information Center

    Clayton, Sarah; Gilmore, Camilla

    2015-01-01

    Dot comparison tasks are commonly used to index an individual's Approximate Number System (ANS) acuity, but the cognitive processes involved in completing these tasks are poorly understood. Here, we investigated how factors including numerosity ratio, set size and visual cues influence task performance. Forty-four children aged 7-9 years completed…

  6. Metric-Free Distributional Comparisons.

    ERIC Educational Resources Information Center

    Haertel, Edward H.; And Others

    Two methods are presented for comparing distributions, such as achievement test score distributions, for distinctly different groups of persons in such a way that the comparison will not be influenced by the particular metric of the test being used. Both methods use percentile scores. One method, attributed to Flanagan, fits a straight line to the…

  7. Group membership and everyday social comparison experiences

    PubMed Central

    SMITH, HEATHER J.; LEACH, COLIN W.

    2006-01-01

    In two everyday experience studies, we examined the degree to which everyday social comparisons are framed by group membership. In the first study, 30 undergraduates attending a public university in the United States completed short questionnaires about their social comparison experiences whenever they were signalled. In the second study, 34 ethnic minority undergraduates from the same university completed similar questionnaires about their social comparison experiences. Across both studies, comparisons in which participants viewed themselves as an ingroup member in comparison to an outgroup comprised less than 10% of the comparison experiences reported by participants. However, minorities in the second study who reported closer identification with their ethnic group reported more comparison experiences in which they mentioned their own or the comparison target's ethnicity. PMID:16691290

  8. Self-Construal and Social Comparison Effects

    ERIC Educational Resources Information Center

    Cheng, Rebecca Wing-yi; Lam, Shui-fong

    2007-01-01

    Background: Social comparison research usually demonstrates that students will have higher self-evaluation in downward comparison but lower self-evaluation in upward comparison. However, the existence of this contrast effect may depend on people's self-construal. The contrast effect may exist only for people with independent self-construal. For…

  9. High pressure rinsing system comparison

    SciTech Connect

    D. Sertore; M. Fusetti; P. Michelato; Carlo Pagani; Toshiyasu Higo; Jin-Seok Hong; K. Saito; G. Ciovati; T. Rothgeb

    2007-06-01

    High pressure rinsing (HPR) is a key process for the surface preparation of high field superconducting cavities. A portable apparatus for the water jet characterization, based on the transferred momentum between the water jet and a load cell, has been used in different laboratories. This apparatus allows to collected quantitative parameters that characterize the HPR water jet. In this paper, we present a quantitative comparison of the different water jet produced by various nozzles routinely used in different laboratories for the HPR process

  10. Comparison of Artificial Compressibility Methods

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Housman, Jeffrey; Kwak, Dochan

    2003-01-01

    Various artificial compressibility methods for calculating three-dimensional, steady and unsteady, laminar and turbulent, incompressible Navier-Stokes equations are compared in this work. Each method is described in detail along with appropriate physical and numerical boundary conditions. Analysis of well-posedness and numerical solutions to test problems for each method are provided. A comparison based on convergence behavior, accuracy, stability and robustness is used to establish the relative positive and negative characteristics of each method.

  11. Comparison of Optimal Thermodynamic Models of the Tricarboxylic Acid Cycle from Heterotrophs, Cyanobacteria, and Green Sulfur Bacteria

    SciTech Connect

    Thomas, Dennis G.; Jaramillo Riveri, Sebastian I.; Baxter, Douglas J.; Cannon, William R.

    2014-12-15

    We have applied a new stochastic simulation approach to predict the metabolite levels, energy flow, and material flux in the different oxidative TCA cycles found in E. coli and Synechococcus sp. PCC 7002, and in the reductive TCA cycle typical of chemolithoautotrophs and phototrophic green sulfur bacteria such as Chlorobaculum tepidum. The simulation approach is based on equations of state and employs an assumption similar to that used in transition state theory. The ability to evaluate the thermodynamics of metabolic pathways allows one to understand the relationship between coupling of energy and material gradients in the environment and the selforganization of stable biological systems, and it is shown that each cycle operates in the direction expected due to its environmental niche. The simulations predict changes in metabolite levels and flux in response to changes in cofactor concentrations that would be hard to predict without an elaborate model based on the law of mass action. In fact, we show that a thermodynamically unfavorable reaction can still have flux in the forward direction when it is part of a reaction network. The ability to predict metabolite levels, energy flow and material flux should be significant for understanding the dynamics of natural systems and for understanding principles for engineering organisms for production of specialty chemicals, such as biofuels.

  12. Comparison of Optimal Thermodynamic Models of the Tricarboxylic Acid Cycle from Heterotrophs, Cyanobacteria, and Green Sulfur Bacteria.

    PubMed

    Thomas, Dennis G; Jaramillo-Riveri, Sebastian; Baxter, Douglas J; Cannon, William R

    2014-12-26

    We have applied a new stochastic simulation approach to predict the metabolite levels, material flux, and thermodynamic profiles of the oxidative TCA cycles found in E. coli and Synechococcus sp. PCC 7002, and in the reductive TCA cycle typical of chemolithoautotrophs and phototrophic green sulfur bacteria such as Chlorobaculum tepidum. The simulation approach is based on modeling states using statistical thermodynamics and employs an assumption similar to that used in transition state theory. The ability to evaluate the thermodynamics of metabolic pathways allows one to understand the relationship between coupling of energy and material gradients in the environment and the self-organization of stable biological systems, and it is shown that each cycle operates in the direction expected due to its environmental niche. The simulations predict changes in metabolite levels and flux in response to changes in cofactor concentrations that would be hard to predict without an elaborate model based on the law of mass action. In fact, we show that a thermodynamically unfavorable reaction can still have flux in the forward direction when it is part of a reaction network. The ability to predict metabolite levels, energy flow, and material flux should be significant for understanding the dynamics of natural systems and for understanding principles for engineering organisms for production of specialty chemicals.

  13. How collective comparisons emerge without individual comparisons of the options.

    PubMed

    Robinson, Elva J H; Feinerman, Ofer; Franks, Nigel R

    2014-07-22

    Collective decisions in animal groups emerge from the actions of individuals who are unlikely to have global information. Comparative assessment of options can be valuable in decision-making. Ant colonies are excellent collective decision-makers, for example when selecting a new nest-site. Here, we test the dependency of this cooperative process on comparisons conducted by individual ants. We presented ant colonies with a choice between new nests: one good and one poor. Using individually radio-tagged ants and an automated system of doors, we manipulated individual-level access to information: ants visiting the good nest were barred from visiting the poor one and vice versa. Thus, no ant could individually compare the available options. Despite this, colonies still emigrated quickly and accurately when comparisons were prevented. Individual-level rules facilitated this behavioural robustness: ants allowed to experience only the poor nest subsequently searched more. Intriguingly, some ants appeared particularly discriminating across emigrations under both treatments, suggesting they had stable, high nest acceptance thresholds. Overall, our results show how a colony of ants, as a cognitive entity, can compare two options that are not both accessible by any individual ant. Our findings illustrate a collective decision process that is robust to differences in individual access to information.

  14. How collective comparisons emerge without individual comparisons of the options

    PubMed Central

    Robinson, Elva J. H.; Feinerman, Ofer; Franks, Nigel R.

    2014-01-01

    Collective decisions in animal groups emerge from the actions of individuals who are unlikely to have global information. Comparative assessment of options can be valuable in decision-making. Ant colonies are excellent collective decision-makers, for example when selecting a new nest-site. Here, we test the dependency of this cooperative process on comparisons conducted by individual ants. We presented ant colonies with a choice between new nests: one good and one poor. Using individually radio-tagged ants and an automated system of doors, we manipulated individual-level access to information: ants visiting the good nest were barred from visiting the poor one and vice versa. Thus, no ant could individually compare the available options. Despite this, colonies still emigrated quickly and accurately when comparisons were prevented. Individual-level rules facilitated this behavioural robustness: ants allowed to experience only the poor nest subsequently searched more. Intriguingly, some ants appeared particularly discriminating across emigrations under both treatments, suggesting they had stable, high nest acceptance thresholds. Overall, our results show how a colony of ants, as a cognitive entity, can compare two options that are not both accessible by any individual ant. Our findings illustrate a collective decision process that is robust to differences in individual access to information. PMID:24920474

  15. Foehn diagnosis and model comparison

    NASA Astrophysics Data System (ADS)

    Duerr, B.; Sprenger, M.; Fuhrer, O.; Burri, K.; Gutermann, T.; Hächler, P.; Neururer, A.; Richner, H.; Werner, R.

    2010-09-01

    The «Alpine Research Group Foehn Rhine Valley - Lake Constance (AGF)» (Arbeitsgemeinschaft Föhnforschung Rheintal-Bodensee) is analysing meteorological parameters and investigating foehn phenomena in the Rhine valley since 1971. Their main goal is to find plausible criteria for reliable foehn forecasts and to deepen our understanding of foehn in the target area. The presentation will focus on two main topics: (a) application of a fully automated foehn diagnosis tool; and (b) comparison of model data (COSMO-2, COSMO-7, VERA, INCA) with measurements in our target area. With respect to (a), the foehn diagnosis tool is applied for different meteorological stations of the Swiss meteorological network (SMN). Although it always uses the same six criteria (relative humidity, wind sector, wind force, gale maximum, difference of potential temperature to SMN site Gütsch and wind sector Gütsch), empirical thresholds have to be determined for each site individually. In doing so, foehn can be objectively detected and automatically identified as such in the most cases. In the second part, referring to (b), the foehn case of the 8th December 2006 is considered. It brought high wind velocities as well as a unusually far-reaching foehn, which was observed even north of Lake Constance. The synoptic- to local-scale dynamics of this foehn case is presented in detail, and the further developments within the framework of COSMO-2 to a high spatial resolution of 2.2 km facilitates the comparison of model forecasts with surface measurements. This comparison will be carried out with several parameters such as wind force, potential temperature and air pressure. Furthermore, the forecasted temporal evolution of foehn will be compared to the foehn's beginning and end detected by the foehn diagnosis tool.

  16. Comparison of ASGARD and UFOCapture

    NASA Technical Reports Server (NTRS)

    Blaauw, Rhiannon C.; Cruse, Katherine S.

    2011-01-01

    The Meteoroid Environment Office is undertaking a comparison between UFOCapture/Analyzer and ASGARD (All Sky and Guided Automatic Realtime Detection). To accomplish this, video output from a Watec video camera on a 17 mm Schneider lens (25 degree field of view) was split and input into the two different meteor detection softwares. The purpose of this study is to compare the sensitivity of the two systems, false alarm rates and trajectory information, among other quantities. The important components of each software will be highlighted and comments made about the detection/rejection algorithms and the amount of user-labor required for each system.

  17. Time comparison via OTS-2

    NASA Technical Reports Server (NTRS)

    Dejong, G.; Kaarls, R.; Kirchner, D.; Ressler, H.

    1982-01-01

    The time comparisons carried out via OTS-2 between the Technical University Graz (Austria) and the Van Swinden Laboratory Delft (Netherlands) are discussed. The method is based on the use of the synchronization pulse in the TV-frame of the daily evening broadcasting of a French TV-program to Northern Africa. Corrections, as a consequence of changes in the position of the satellite coordinates are applied weekly after reception of satellite coordinates. A description of the method is given as well as some of the particular techniques used in both the participating laboratories. Preliminary results are presented.

  18. EXCOMP: an exposure comparison methodology

    SciTech Connect

    Lavender, J.C.; Franklin, A.L.

    1986-01-01

    When designing new facilities or modifying existing facilities that involve radioactive material, handling or processing, an area of concern is the radiological exposure received by facility personnel and the environment. The computerized models that are currently used for exposure evaluations are capable of evaluating only one relationship at a time, i.e., the effects of one source, its strength and location, on one work location. EXCOMP (EXposure COMParison) is a methodology developed for the IBM-PC to evaluate radiological exposures. It is capable of evaluating each identified work location in a facility with respect to each identified source effecting it.

  19. Inverter performance comparison at PVUSA

    SciTech Connect

    Farmer, B.K.; Stolte, W.J.; Reyes, A.B.

    1996-01-01

    The paper is a summary of the Photovoltaics for Utility Scale Applications (PVUSA) Project{close_quote}s experience with procurement, testing, operation and maintenance of photovoltaic (PV) power conditioning units (PCUs) at the PVUSA Davis and Kerman sites. Brief descriptions of each of five different PCU models are included to explain tests and operational characteristics. A comparison of the PCUs{close_quote} performances is presented, and conclusions are offered. Further details are in a forthcoming PVUSA report on PCUs and Power Quality [1]. {copyright} {ital 1996 American Institute of Physics.}

  20. Spore Size Comparison Between Several Bacillus Species

    DTIC Science & Technology

    2005-10-01

    Spore Size Comparison Between Several Bacillus Species Ruben O. Zandomeni1, Joseph E. Fitzgibbon2, Monica Carrera1, Edward Stuebing2, James E...OCT 2005 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Spore Size Comparison Between Several Bacillus Species 5a. CONTRACT...Systematic comparison of the size of B.anthracis spores to size of other Bacillus spores (simulants/surrogates) - all spores produced under the same

  1. Computational Chemistry Comparison and Benchmark Database

    National Institute of Standards and Technology Data Gateway

    SRD 101 NIST Computational Chemistry Comparison and Benchmark Database (Web, free access)   The NIST Computational Chemistry Comparison and Benchmark Database is a collection of experimental and ab initio thermochemical properties for a selected set of molecules. The goals are to provide a benchmark set of molecules for the evaluation of ab initio computational methods and allow the comparison between different ab initio computational methods for the prediction of thermochemical properties.

  2. The Timing of Social Comparison in Crowds

    DTIC Science & Technology

    2009-08-18

    and second, it is inspired by social psychology theory. In particular, the model is based on Social Comparison Theory (SCT) ( Festinger , 1954), a...evaluate its own progress ( Festinger , 1954). This approach, in which the social comparison process is triggered only when the agent is uncertain as to how to...developing a model of social behavior inspired by Festinger’s social comparison theory ( Festinger , 1954). To the best of our knowl- edge, social

  3. European Measurement Comparisons of Environmental Radioactivity

    SciTech Connect

    Waetjen, Uwe

    2008-08-14

    The scheme of European measurement comparisons to verify radioactivity monitoring in the European Union is briefly explained. After a review of comparisons conducted during the years 1990, the approach of IRMM organising these comparisons since 2003 is presented. IRMM is providing comparison samples with a reference value traceable to the SI units and which is fully documented to all participants and national authorities after completion of the comparison. The sample preparation and determination of traceable reference values at IRMM, the sample treatment and measurement in the participating laboratories, as well as the evaluation of comparison results are described in some detail using the example of an air filter comparison. The results of a comparison to determine metabolised {sup 40}K, {sup 90}Sr and {sup 137}Cs in milk powder are presented as well. The necessary improvements in the estimation of measurement uncertainty by the participating laboratories are discussed. The performance of individual laboratories which have participated in at least four comparison exercises over the years is studied in terms of observable trends.

  4. The neural correlates of beauty comparison.

    PubMed

    Kedia, Gayannée; Mussweiler, Thomas; Mullins, Paul; Linden, David E J

    2014-05-01

    Beauty is in the eye of the beholder. How attractive someone is perceived to be depends on the individual or cultural standards to which this person is compared. But although comparisons play a central role in the way people judge the appearance of others, the brain processes underlying attractiveness comparisons remain unknown. In the present experiment, we tested the hypothesis that attractiveness comparisons rely on the same cognitive and neural mechanisms as comparisons of simple nonsocial magnitudes such as size. We recorded brain activity with functional magnetic resonance imaging (fMRI) while participants compared the beauty or height of two women or two dogs. Our data support the hypothesis of a common process underlying these different types of comparisons. First, we demonstrate that the distance effect characteristic of nonsocial comparisons also holds for attractiveness comparisons. Behavioral results indicated, for all our comparisons, longer response times for near than far distances. Second, the neural correlates of these distance effects overlapped in a frontoparietal network known for its involvement in processing simple nonsocial quantities. These results provide evidence for overlapping processes in the comparison of physical attractiveness and nonsocial magnitudes.

  5. Collaborative Comparison of Earthquake Simulators

    NASA Astrophysics Data System (ADS)

    Richards-Dinger, K.; Zielke, O.; Tullis, T. E.; Ward, S. N.; Kaneko, Y.; Shaw, B. E.; Lapusta, N.; Pollitz, F. F.; Morein, G.; Turcotte, D. L.; Robinson, R.; Dieterich, J. H.; Rundle, J. D.; Beeler, N. M.

    2008-12-01

    Earthquake simulators, i.e. computer models in which a series of earthquakes spontaneously occur, are important for understanding earthquake mechanics and earthquake predictability. However, to use earthquake simulators in hazard anaylsis they must show realistic behavior. It is difficult to determine how realistic simulator results are. This is in part because of the complexity of their behavior and the limited database of long sequences of natural earthquakes, especially large ones, against which to compare a simulator's behavior. Due to limits on memory and computation speed it is presently impossible to construct a simulator that simultaneously incorporates everything known about frictional behavior of rock, includes full elastodynamics, and utilizes both small enough elements to properly represent a continuum and enough elements to cover a large geographic area and represent many faults. Consequently, all simulators make compromises. A wide variety of simulators exist, each with different compromises. The effects on the simulator results of these compromises are not currently known. Our goal is to gain a better understanding of the validity of the results of earthquake simulators. This is a joint effort to compare the behavior of our nine independently devised earthquake simulators. We have defined and studied two simple problems. The first checks that each simulator accurately gives the stresses due to slip on a simple vertical strike-slip fault. All simulators satisfactorily passed this test. The second is a comparison of the behavior of a simple strike slip fault, with a simple bi-linear asymmetrically peaked initial stress distribution, and a constant loading rate. The fault constitutive properties have a fixed failure stress, higher than the peak in the initial stress, and a fixed dynamic sliding stress, although models utilizing rate and state friction only approximate this simple description. A series of earthquakes occur in the simulations and the

  6. Comparison of column flotation cells

    SciTech Connect

    Honaker, R.Q.; Mohanty, M.K.; Ho, K.

    1995-08-01

    Six commercial column flotation technologies, i.e., Canadian, Flotaire, Jameson, Microcel, Packed-Column, and Turbo-air, were tested for the treatment of Illinois Basin fine coal and the results from each column compared based on separation performance and throughout capacity. The separation performance achieved by each cell approached and, in some cases, exceeded the ultimate performance predicted by release analysis. A comparison of the test results indicates differences in the selectivity obtained by each flotation column on the basis of both ash and sulfur rejection. This finding may be due to variations in cell hydrodynamics and the ability to support a deep froth phase among the different column cells. In addition, throughput capacity of each cell was found to differ, apparently due to the differences in the bubble-particle attachment environment, bubble size, and bubble population. Variations in the operating characteristics, such as reagent additions, aeration rate and wash water rate, were also noted and summarized in this publication.

  7. Comparison of Hartmann analysis methods.

    PubMed

    Canovas, Carmen; Ribak, Erez N

    2007-04-01

    Analysis of Hartmann-Shack wavefront sensors for the eye is traditionally performed by locating and centroiding the sensor spots. These centroids provide the gradient, which is integrated to yield the ocular aberration. Fourier methods can replace the centroid stage, and Fourier integration can replace the direct integration. The two--demodulation and integration--can be combined to directly retrieve the wavefront, all in the Fourier domain. Now we applied this full Fourier analysis to circular apertures and real images. We performed a comparison between it and previous methods of convolution, interpolation, and Fourier demodulation. We also compared it with a centroid method, which yields the Zernike coefficients of the wavefront. The best performance was achieved for ocular pupils with a small boundary slope or far from the boundary and acceptable results for images missing part of the pupil. The other Fourier analysis methods had much higher tolerance to noncentrosymmetric apertures.

  8. MCNPX Model/Table Comparison

    SciTech Connect

    J.S. Hendricks

    2003-03-03

    MCNPX is a Monte Carlo N-Particle radiation transport code extending the capabilities of MCNP4C. As with MCNP, MCNPX uses nuclear data tables to transport neutrons, photons, and electrons. Unlike MCNP, MCNPX also uses (1) nuclear data tables to transport protons; (2) physics models to transport 30 additional particle types (deuterons, tritons, alphas, pions, muons, etc.); and (3) physics models to transport neutrons and protons when no tabular data are available or when the data are above the energy range (20 to 150 MeV) where the data tables end. MCNPX can mix and match data tables and physics models throughout a problem. For example, MCNPX can model neutron transport in a bismuth germinate (BGO) particle detector by using data tables for bismuth and oxygen and using physics models for germanium. Also, MCNPX can model neutron transport in UO{sub 2}, making the best use of physics models and data tables: below 20 MeV, data tables are used; above 150 MeV, physics models are used; between 20 and 150 MeV, data tables are used for oxygen and models are used for uranium. The mix-and-match capability became available with MCNPX2.5.b (November 2002). For the first time, we present here comparisons that calculate radiation transport in materials with various combinations of data charts and model physics. The physics models are poor at low energies (<150 MeV); thus, data tables should be used when available. Our comparisons demonstrate the importance of the mix-and-match capability and indicate how well physics models work in the absence of data tables.

  9. Initial characterization of the photosynthetic apparatus of "Candidatus Chlorothrix halophila," a filamentous, anoxygenic photoautotroph.

    PubMed

    van de Meene, Allison M L; Le Olson, Tien; Collins, Aaron M; Blankenship, Robert E

    2007-06-01

    "Candidatus Chlorothrix halophila" is a recently described halophilic, filamentous, anoxygenic photoautotroph (J. A. Klappenbach and B. K. Pierson, Arch. Microbiol. 181:17-25, 2004) that was enriched from the hypersaline microbial mats at Guerrero Negro, Mexico. Analysis of the photosynthetic apparatus by negative staining, spectroscopy, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the photosynthetic apparatus in this organism has similarities to the photosynthetic apparatus in both the Chloroflexi and Chlorobi phyla of green photosynthetic bacteria. The chlorosomes were found to be ellipsoidal and of various sizes, characteristics that are comparable to characteristics of chlorosomes in other species of green photosynthetic bacteria. The absorption spectrum of whole cells was dominated by the chlorosome bacteriochlorophyll c (BChl c) peak at 759 nm, with fluorescence emission at 760 nm. A second fluorescence emission band was observed at 870 nm and was tentatively attributed to a membrane-bound antenna complex. Fluorescence emission spectra obtained at 77 K revealed another complex that fluoresced at 820 nm, which probably resulted from the chlorosome baseplate complex. All of these results suggest that BChl c is present in the chlorosomes of "Ca. Chlorothrix halophila," that BChl a is present in the baseplate, and that there is a membrane-bound antenna complex. Analysis of the proteins in the chlorosomes revealed an approximately 6-kDa band, which was found to be related to the BChl c binding protein CsmA found in other green bacteria. Overall, the absorbance and fluorescence spectra of "Ca. Chlorothrix halophila" revealed an interesting mixture of photosynthetic characteristics that seemed to have properties similar to properties of both phyla of green bacteria when they were compared to the photosynthetic characteristics of Chlorobium tepidum and Chloroflexus aurantiacus.

  10. Nonphotochemical Hole-Burning Studies of Energy Transfer Dynamics in Antenna Complexes of Photosynthetic Bacteria

    SciTech Connect

    Matsuzaki, Satoshi

    2001-01-01

    This thesis contains the candidate's original work on excitonic structure and energy transfer dynamics of two bacterial antenna complexes as studied using spectral hole-burning spectroscopy. The general introduction is divided into two chapters (1 and 2). Chapter 1 provides background material on photosynthesis and bacterial antenna complexes with emphasis on the two bacterial antenna systems related to the thesis research. Chapter 2 reviews the underlying principles and mechanism of persistent nonphotochemical hole-burning (NPHB) spectroscopy. Relevant energy transfer theories are also discussed. Chapters 3 and 4 are papers by the candidate that have been published. Chapter 3 describes the application of NPHB spectroscopy to the Fenna-Matthews-Olson (FMO) complex from the green sulfur bacterium Prosthecochloris aestuarii; emphasis is on determination of the low energy vibrational structure that is important for understanding the energy transfer process associated within three lowest energy Qy-states of the complex. The results are compared with those obtained earlier on the FMO complex from Chlorobium tepidum. In Chapter 4, the energy transfer dynamics of the B800 molecules of intact LH2 and B800-deficient LH2 complexes of the purple bacterium Rhodopseudomonas acidophila are compared. New insights on the additional decay channel of the B800 ring of bacteriochlorophylla (BChla) molecules are provided. General conclusions are given in Chapter 5. A version of the hole spectrum simulation program written by the candidate for the FMO complex study (Chapter 3) is included as an appendix. The references for each chapter are given at the end of each chapter.

  11. 16 CFR 233.2 - Retail price comparisons; comparable value comparisons.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Retail price comparisons; comparable value... GUIDES AGAINST DECEPTIVE PRICING § 233.2 Retail price comparisons; comparable value comparisons. (a... higher price must be based upon fact, and not be fictitious or misleading. Whenever an...

  12. Forensic voice comparison and the paradigm shift.

    PubMed

    Morrison, Geoffrey Stewart

    2009-12-01

    We are in the midst of a paradigm shift in the forensic comparison sciences. The new paradigm can be characterised as quantitative data-based implementation of the likelihood-ratio framework with quantitative evaluation of the reliability of results. The new paradigm was widely adopted for DNA profile comparison in the 1990s, and is gradually spreading to other branches of forensic science, including forensic voice comparison. The present paper first describes the new paradigm, then describes the history of its adoption for forensic voice comparison over approximately the last decade. The paradigm shift is incomplete and those working in the new paradigm still represent a minority within the forensic-voice-comparison community.

  13. Comparison of debris flux models

    NASA Astrophysics Data System (ADS)

    Sdunnus, H.; Beltrami, P.; Klinkrad, H.; Matney, M.; Nazarenko, A.; Wegener, P.

    The availability of models to estimate the impact risk from the man-made space debris and the natural meteoroid environment is essential for both, manned and unmanned satellite missions. Various independent tools based on different approaches have been developed in the past years. Due to an increased knowledge of the debris environment and its sources e.g. from improved measurement capabilities, these models could be updated regularly, providing more detailed and more reliable simulations. This paper addresses an in-depth, quantitative comparison of widely distributed debris flux models which were recently updated, namely ESA's MASTER 2001 model, NASA's ORDEM 2000 and the Russian SDPA 2000 model. The comparison was performed in the frame of the work of the 20t h Interagency Debris Coordination (IADC) meeting held in Surrey, UK. ORDEM 2000ORDEM 2000 uses careful empirical estimates of the orbit populations based onthree primary data sources - the US Space Command Catalog, the H ystackaRadar, and the Long Duration Exposure Facility spacecraft returned surfaces.Further data (e.g. HAX and Goldstone radars, impacts on Shuttle windows andradiators, and others) were used to adjust these populations for regions in time,size, and space not covered by the primary data sets. Some interpolation andextrapolation to regions with no data (such as projections into the future) wasprovided by the EVOLVE model. MASTER 2001The ESA MASTER model offers a full three dimensional description of theterrestrial debris distribution reaching from LEO up to the GEO region. Fluxresults relative to an orbiting target or to an inertial volume can be resolved intosource terms, impactor characteristics and orbit, as well as impact velocity anddirection. All relevant debris source terms are considered by the MASTERmodel. For each simulated source, a corresponding debris generation model interms of mass/diameter distribution, additional velocities, and directionalspreading has been developed. A

  14. The current status of microscopical hair comparisons.

    PubMed

    Rowe, W F

    2001-12-08

    Although the microscopical comparison of human hairs has been accepted in courts of law for over a century, recent advances in DNA technology have called this type of forensic examination into question. In a number of cases, post-conviction DNA testing has exonerated defendants who were convicted in part on the results of microscopical hair comparisons. A federal judge has held a Daubert hearing on the microscopical comparison of human hairs and has concluded that this type of examination does not meet the criteria for admission of scientific evidence in federal courts. A review of the available scientific literature on microscopical hair comparisons (including studies conducted by the Royal Canadian Mounted Police and the Federal Bureau of Investigation) leads to three conclusions: (1) microscopical comparisons of human hairs can yield scientifically defensible conclusions that can contribute to criminal investigations and criminal prosecutions, (2) the reliability of microscopical hair comparisons is strongly affected by the training of the forensic hair examiner, (3) forensic hair examiners cannot offer estimates of the probability of a match of a questioned hair with a hair from a randomly selected person. In order for microscopical hair examinations to survive challenges under the U.S. Supreme Court's Daubert decision, hair microscopists must be better trained and undergo frequent proficiency testing. More research on the error rates of microscopical hair comparisons should be undertaken, and guidelines for the permissible interpretations of such comparisons should be established. Until these issues have been addressed and satisfactorily resolved, microscopical hair comparisons should be regarded by law enforcement agencies and courts of law as merely presumptive in nature, and all microscopical hair comparisons should be confirmed by nuclear DNA profiling or mitochondrial DNA sequencing.

  15. Helicity comparison among three magnetographs

    NASA Astrophysics Data System (ADS)

    Xu, Haiqing; Gao, Yu; Zhang, Hongqi; Sakurai, T.; Pevtsov, A. A.; Sokoloff, D.

    We compare vector magnetograms of 228 active regions observed by Solar Magnetic Field Telescope (SMFT) at Huairou (HR) Solar Observing Station and the Solar Flare Telescope (SFT) at Mitaka (MTK) of the National Astronomical Observatory of Japan from 1992 to 2005 and 55 active regions observed by SFT and Haleakala Stokes Polarimeter (HSP) at Mees Solar Observatory, University of Hawaii from 1997 to 2000. Two helicity parameters, current helicity density hc and αff coefficient of linear force free field are calculated. From this comparison we conclude: (1) the mean azimuthal angle differences of transverse fields between HR and MTK data are systematic smaller than that between MTK and Mees data; (2) there are 83.8% of hc and 78.1% of αff for 228 active regions observed at HR and MTK agree in sign, and the Pearson linear correlation coefficient between these two data sets is 0.72 for hc and 0.56 for αff. There are 61.8% of hc and 58.2% of αff for 55 active regions observed at MTK and Mees agree in sign, and the Pearson linear correlation coefficient between these two data sets is 0.34 for hc and 0.31 for αff; (3) there is a basic agreement on time variation of helicity parameters in active regions observed at HR, Mees, and MTK.

  16. Comparison theorems for causal diamonds

    NASA Astrophysics Data System (ADS)

    Berthiere, Clément; Gibbons, Gary; Solodukhin, Sergey N.

    2015-09-01

    We formulate certain inequalities for the geometric quantities characterizing causal diamonds in curved and Minkowski spacetimes. These inequalities involve the redshift factor which, as we show explicitly in the spherically symmetric case, is monotonic in the radial direction, and it takes its maximal value at the center. As a by-product of our discussion we rederive Bishop's inequality without assuming the positivity of the spatial Ricci tensor. We then generalize our considerations to arbitrary, static and not necessarily spherically symmetric, asymptotically flat spacetimes. In the case of spacetimes with a horizon our generalization involves the so-called domain of dependence. The respective volume, expressed in terms of the duration measured by a distant observer compared with the volume of the domain in Minkowski spacetime, exhibits behaviors which differ if d =4 or d >4 . This peculiarity of four dimensions is due to the logarithmic subleading term in the asymptotic expansion of the metric near infinity. In terms of the invariant duration measured by a comoving observer associated with the diamond we establish an inequality which is universal for all d . We suggest some possible applications of our results including comparison theorems for entanglement entropy, causal set theory, and fundamental limits on computation.

  17. Performance Comparison of CGM Systems

    PubMed Central

    Kirchsteiger, Harald; Heinemann, Lutz; Freckmann, Guido; Lodwig, Volker; Schmelzeisen-Redeker, Günther; Schoemaker, Michael; del Re, Luigi

    2015-01-01

    Background: The ongoing progress of continuous glucose monitoring (CGM) systems results in an increasing interest in comparing their performance, in particular in terms of accuracy, that is, matching CGM readings with reference values measured at the same time. Most often accuracy is evaluated by the mean absolute relative difference (MARD). It is frequently overseen that MARD does not only reflect accuracy, but also the study protocol and evaluation procedure, making a cross-study comparison problematic. Methods: We evaluate the effect of several factors on the MARD statistical properties: number of paired reference and CGM values, distribution of the paired values, accuracy of the reference measurement device itself and the time delay between data pairs. All analysis is done using clinical data from 12 patients wearing 6 sensors each. Results: We have found that a few paired points can have a potentially high impact on MARD. Leaving out those points for evaluation thus reduces the MARD. Similarly, accuracy of the reference measurements greatly affects the MARD as numerical and graphical data show. Results also show that a log-normal distribution of the paired references provides a significantly different MARD than, for example, a uniform distribution. Conclusions: MARD is a reasonable parameter to characterize the performance of CGM systems when keeping its limitations in mind. To support clinicians and patients in selecting which CGM system to use in a clinical setting, care should be taken to make MARD more comparable by employing a standardized evaluation procedure. PMID:26330485

  18. Distributed Wind Policy Comparison Tool

    SciTech Connect

    2011-12-01

    Power through Policy: 'Best Practices' for Cost-Effective Distributed Wind is a U.S. Department of Energy (DOE)-funded project to identify distributed wind technology policy best practices and to help policymakers, utilities, advocates, and consumers examine their effectiveness using a pro forma model. Incorporating a customized feed from the Database of State Incentives for Renewables and Efficiency (DSIRE), the Web-based Distributed Wind Policy Comparison Tool (Policy Tool) is designed to assist state, local, and utility officials in understanding the financial impacts of different policy options to help reduce the cost of distributed wind technologies. The Policy Tool can be used to evaluate the ways that a variety of federal and state policies and incentives impact the economics of distributed wind (and subsequently its expected market growth). It also allows policymakers to determine the impact of policy options, addressing market challenges identified in the U.S. DOE’s '20% Wind Energy by 2030' report and helping to meet COE targets.

  19. RTU Comparison Calculator Enhancement Plan

    SciTech Connect

    Miller, James D.; Wang, Weimin; Katipamula, Srinivas

    2014-03-31

    Over the past two years, Department of Energy’s Building Technologies Office (BTO) has been investigating ways to increase the operating efficiency of the packaged rooftop units (RTUs) in the field. First, by issuing a challenge to the RTU manufactures to increase the integrated energy efficiency ratio (IEER) by 60% over the existing ASHRAE 90.1-2010 standard. Second, by evaluating the performance of an advanced RTU controller that reduces the energy consumption by over 40%. BTO has previously also funded development of a RTU comparison calculator (RTUCC). RTUCC is a web-based tool that provides the user a way to compare energy and cost savings for two units with different efficiencies. However, the RTUCC currently cannot compare savings associated with either the RTU Challenge unit or the advanced RTU controls retrofit. Therefore, BTO has asked PNNL to enhance the tool so building owners can compare energy and savings associated with this new class of products. This document provides the details of the enhancements that are required to support estimating energy savings from use of RTU challenge units or advanced controls on existing RTUs.

  20. RTU Comparison Calculator Enhancement Plan

    SciTech Connect

    Miller, James D.; Wang, Weimin; Katipamula, Srinivas

    2015-07-01

    Over the past two years, Department of Energy’s Building Technologies Office (BTO) has been investigating ways to increase the operating efficiency of the packaged rooftop units (RTUs) in the field. First, by issuing a challenge to the RTU manufactures to increase the integrated energy efficiency ratio (IEER) by 60% over the existing ASHRAE 90.1-2010 standard. Second, by evaluating the performance of an advanced RTU controller that reduces the energy consumption by over 40%. BTO has previously also funded development of a RTU comparison calculator (RTUCC). RTUCC is a web-based tool that provides the user a way to compare energy and cost savings for two units with different efficiencies. However, the RTUCC currently cannot compare savings associated with either the RTU Challenge unit or the advanced RTU controls retrofit. Therefore, BTO has asked PNNL to enhance the tool so building owners can compare energy and savings associated with this new class of products. This document provides the details of the enhancements that are required to support estimating energy savings from use of RTU challenge units or advanced controls on existing RTUs.

  1. Attractor comparisons based on density

    SciTech Connect

    Carroll, T. L.

    2015-01-15

    Recognizing a chaotic attractor can be seen as a problem in pattern recognition. Some feature vector must be extracted from the attractor and used to compare to other attractors. The field of machine learning has many methods for extracting feature vectors, including clustering methods, decision trees, support vector machines, and many others. In this work, feature vectors are created by representing the attractor as a density in phase space and creating polynomials based on this density. Density is useful in itself because it is a one dimensional function of phase space position, but representing an attractor as a density is also a way to reduce the size of a large data set before analyzing it with graph theory methods, which can be computationally intensive. The density computation in this paper is also fast to execute. In this paper, as a demonstration of the usefulness of density, the density is used directly to construct phase space polynomials for comparing attractors. Comparisons between attractors could be useful for tracking changes in an experiment when the underlying equations are too complicated for vector field modeling.

  2. An ecological momentary assessment of comparison target as a moderator of the effects of appearance-focused social comparisons.

    PubMed

    Leahey, Tricia M; Crowther, Janis H

    2008-09-01

    This research examined whether comparison target moderates the effects of naturally occurring appearance-focused social comparisons on women's affect, appearance esteem, and dieting thoughts. During daily activities, body-satisfied (BS) women and body-dissatisfied (BD) women recorded their comparison targets and reactions to comparison information. For BS women, upward comparisons with peers were associated with more positive affect (PA) and appearance esteem and less guilt than upward comparisons with media images and downward comparisons with peers were associated with less PA than downward comparisons with media images. For BD women, upward comparisons with peers were associated with more appearance esteem and diet thoughts than upward comparisons with media images and downward comparisons with peers were associated with less PA, appearance esteem, and diet thoughts and more guilt than downward comparisons with media images.

  3. Uav Photogrammetry: Block Triangulation Comparisons

    NASA Astrophysics Data System (ADS)

    Gini, R.; Pagliari, D.; Passoni, D.; Pinto, L.; Sona, G.; Dosso, P.

    2013-08-01

    UAVs systems represent a flexible technology able to collect a big amount of high resolution information, both for metric and interpretation uses. In the frame of experimental tests carried out at Dept. ICA of Politecnico di Milano to validate vector-sensor systems and to assess metric accuracies of images acquired by UAVs, a block of photos taken by a fixed wing system is triangulated with several software. The test field is a rural area included in an Italian Park ("Parco Adda Nord"), useful to study flight and imagery performances on buildings, roads, cultivated and uncultivated vegetation. The UAV SenseFly, equipped with a camera Canon Ixus 220HS, flew autonomously over the area at a height of 130 m yielding a block of 49 images divided in 5 strips. Sixteen pre-signalized Ground Control Points, surveyed in the area through GPS (NRTK survey), allowed the referencing of the block and accuracy analyses. Approximate values for exterior orientation parameters (positions and attitudes) were recorded by the flight control system. The block was processed with several software: Erdas-LPS, EyeDEA (Univ. of Parma), Agisoft Photoscan, Pix4UAV, in assisted or automatic way. Results comparisons are given in terms of differences among digital surface models, differences in orientation parameters and accuracies, when available. Moreover, image and ground point coordinates obtained by the various software were independently used as initial values in a comparative adjustment made by scientific in-house software, which can apply constraints to evaluate the effectiveness of different methods of point extraction and accuracies on ground check points.

  4. STS-134 Launch Composite Video Comparison

    NASA Video Gallery

    A side-by-side comparison video shows a one-camera view of the STS-134 launch (left) with the six-camera composited view (right). Imaging experts funded by the Space Shuttle Program and located at ...

  5. OpenMP Experiences and Comparisons

    NASA Technical Reports Server (NTRS)

    Nelson, Terry; Thigpen, William W. (Technical Monitor)

    2002-01-01

    The document discusses message passage interfaces (MPI), open message passage issues and parallelization. A comparison of the two vector platforms, C90 and SVlex is presented. Sections of the document are written in computer code.

  6. 78 FR 38075 - International Labor Comparisons

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-25

    ... Comparisons (ILC) program adjusted foreign data to a common framework of concepts, definitions, and... Molina, Acting Chief, Division of Management Systems, Bureau of Labor Statistics. BILLING CODE 4510-24-P...

  7. Doctoral Program Selection Using Pairwise Comparisons.

    ERIC Educational Resources Information Center

    Tadisina, Suresh K.; Bhasin, Vijay

    1989-01-01

    The application of a pairwise comparison methodology (Saaty's Analytic Hierarchy Process) to the doctoral program selection process is illustrated. A hierarchy for structuring and facilitating the doctoral program selection decision is described. (Author/MLW)

  8. Rankings, Standards, and Competition: Task vs. Scale Comparisons

    ERIC Educational Resources Information Center

    Garcia, Stephen M.; Tor, Avishalom

    2007-01-01

    Research showing how upward social comparison breeds competitive behavior has so far conflated local comparisons in "task" performance (e.g. a test score) with comparisons on a more general "scale" (i.e. an underlying skill). Using a ranking methodology (Garcia, Tor, & Gonzalez, 2006) to separate task and scale comparisons, Studies 1-2 reveal that…

  9. Differential Item Functioning Detection across Two Methods of Defining Group Comparisons: Pairwise and Composite Group Comparisons

    ERIC Educational Resources Information Center

    Sari, Halil Ibrahim; Huggins, Anne Corinne

    2015-01-01

    This study compares two methods of defining groups for the detection of differential item functioning (DIF): (a) pairwise comparisons and (b) composite group comparisons. We aim to emphasize and empirically support the notion that the choice of pairwise versus composite group definitions in DIF is a reflection of how one defines fairness in DIF…

  10. 16 CFR 233.2 - Retail price comparisons; comparable value comparisons.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... GUIDES AGAINST DECEPTIVE PRICING § 233.2 Retail price comparisons; comparable value comparisons. (a... here would be deceptive, since the price charged by the small suburban outlets would have no real... similar pen, for that price, this advertisement would be deceptive....

  11. 16 CFR 233.2 - Retail price comparisons; comparable value comparisons.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... GUIDES AGAINST DECEPTIVE PRICING § 233.2 Retail price comparisons; comparable value comparisons. (a... here would be deceptive, since the price charged by the small suburban outlets would have no real... similar pen, for that price, this advertisement would be deceptive....

  12. 16 CFR 233.2 - Retail price comparisons; comparable value comparisons.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... GUIDES AGAINST DECEPTIVE PRICING § 233.2 Retail price comparisons; comparable value comparisons. (a... here would be deceptive, since the price charged by the small suburban outlets would have no real... similar pen, for that price, this advertisement would be deceptive....

  13. Comparisons between Intel 386 and i486 microprecessors

    NASA Technical Reports Server (NTRS)

    Liu, Yuan-Kwei

    1989-01-01

    A quick and preliminary comparison is made between the Intel 386 and i486 microprocessors. The following topics are discussed: the i486 key elements, comparison of instruction set architecture, the i486 on-chip cache characteristics, the i486 multiprocessor support, comparison of performance, comparison of power consumption, comparison of radiation hardening potential, and recommendations for the Space Station Freedom (SSF) Data Management System (DMS).

  14. Comparison of Tritium Component Failure Rate Data

    SciTech Connect

    Lee C. Cadwallader

    2004-09-01

    Published failure rate values from the US Tritium Systems Test Assembly, the Japanese Tritium Process Laboratory, the German Tritium Laboratory Karlsruhe, and the Joint European Torus Active Gas Handling System have been compared. This comparison is on a limited set of components, but there is a good variety of data sets in the comparison. The data compared reasonably well. The most reasonable failure rate values are recommended for use on next generation tritium handling system components, such as those in the tritium plant systems for the International Thermonuclear Experimental Reactor and the tritium fuel systems of inertial fusion facilities, such as the US National Ignition Facility. These data and the comparison results are also shared with the International Energy Agency cooperative task on fusion component failure rate data.

  15. Real medical benefit assessed by indirect comparison.

    PubMed

    Falissard, Bruno; Zylberman, Myriam; Cucherat, Michel; Izard, Valérie; Meyer, François

    2009-01-01

    Frequently, in data packages submitted for Marketing Approval to the CHMP, there is a lack of relevant head-to-head comparisons of medicinal products that could enable national authorities responsible for the approval of reimbursement to assess the Added Therapeutic Value (ASMR) of new clinical entities or line extensions of existing therapies.Indirect or mixed treatment comparisons (MTC) are methods stemming from the field of meta-analysis that have been designed to tackle this problem. Adjusted indirect comparisons, meta-regressions, mixed models, Bayesian network analyses pool results of randomised controlled trials (RCTs), enabling a quantitative synthesis.The REAL procedure, recently developed by the HAS (French National Authority for Health), is a mixture of an MTC and effect model based on expert opinions. It is intended to translate the efficacy observed in the trials into effectiveness expected in day-to-day clinical practice in France.

  16. Photon/Electron Benchmarks for Intercode Comparisons

    SciTech Connect

    Hughes, Henry Grady III; Sweezy, Jeremy Ed; Lemaire, Sebastien

    2015-07-21

    The goal of this work was to improve accuracy and efficiency of two Monte-Carlo transport codes (MCNP and DIANE) with an emphasis on γ+electron physics. The approach involved intercode comparisons + measurements for gamma/e- energy deposition in a cylinder with a photon source and different materials (C, Pb) and the bombardment of 15-MeV electrons on thick targets (Al, Be, Pb). Comparisons of the codes DIANE and MCNP6 showed good agreement (differences < 3%) for gamma-electron energy deposition in a 2D cylinder, except for the first 0.1 μm of lead (difference < 10%). Comparisons with measurements showed generally good agreement, often better than 10%; best-performing codes/options are problem-dependent; and single-event discrepancies are in active use in reviewing electron elastic scattering.

  17. A comparison study of hair examination methodologies.

    PubMed

    Kolowski, Jason C; Petraco, Nicholas; Wallace, Margaret M; De Forest, Peter R; Prinz, Mechthild

    2004-11-01

    A study was conducted to investigate the accuracy between two methods of hair analysis: PCR-STR DNA analysis and microscopic comparison analysis. Standard sets of pubic hairs were collected from volunteers, and unknown sets were generated from these samples. Three out of five (60%) of the hairs analyzed produced full DNA profiles that were correctly matched to the standard sets. DNA analysis was inconclusive (partial or no DNA profile) for two out of five (40%) of the samples. In contrast, the microscopic comparison analysis correctly matched four out of five (80%) of the samples to the standard sets but mis-identified one out of five (20%) of the samples. These results reinforce the practice of preliminary microscopic hair examination in narrowing down a set of hairs for DNA analysis. Microscopic comparison analysis is sufficiently reliable to remain a rapid and inexpensive method for forensic hair analysis.

  18. Infrared spectral normal emittance/emissivity comparison

    NASA Astrophysics Data System (ADS)

    Hanssen, L.; Wilthan, B.; Filtz, J.-R.; Hameury, J.; Girard, F.; Battuello, M.; Ishii, J.; Hollandt, J.; Monte, C.

    2016-01-01

    The National Measurement Institutes (NMIs) of the United States, Germany, France, Italy and Japan, have joined in an inter-laboratory comparison of their infrared spectral emittance scales. This action is part of a series of supplementary inter-laboratory comparisons (including thermal conductivity and thermal diffusivity) sponsored by the Consultative Committee on Thermometry (CCT) Task Group on Thermophysical Quantities (TG-ThQ). The objective of this collaborative work is to strengthen the major operative National Measurement Institutes' infrared spectral emittance scales and consequently the consistency of radiative properties measurements carried out worldwide. The comparison has been performed over a spectral range of 2 μm to 14 μm, and a temperature range from 23 °C to 800 °C. Artefacts included in the comparison are potential standards: oxidized Inconel, boron nitride, and silicon carbide. The measurement instrumentation and techniques used for emittance scales are unique for each NMI, including the temperature ranges covered as well as the artefact sizes required. For example, all three common types of spectral instruments are represented: dispersive grating monochromator, Fourier transform and filter-based spectrometers. More than 2000 data points (combinations of material, wavelength and temperature) were compared. Ninety-eight percent (98%) of the data points were in agreement, with differences to weighted mean values less than the expanded uncertainties calculated from the individual NMI uncertainties and uncertainties related to the comparison process. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  19. Key comparison of liquid density standards

    NASA Astrophysics Data System (ADS)

    Buchner, Christian; Zelenka, Zoltan; Kajastie, Heikki; Madec, Tanguy; Wolf, Henning; Vámossy, Csilla; Lorefice, Salvatore; Garberg, Torgunn; Lenard, Elżbieta; Spohr, Isabel; Mares, Gabriela; Spurný, Robert; Lumbreras, Angel; Medina, Nieves; Y Akçadağ, Ümit; Perkin, Michael

    2015-01-01

    Hydrostatic density determination for liquids is mainly performed by laboratories to provide means for calibrating liquid density measuring instruments such as oscillation-type density meters. From 2002 to 2005 the CIPM key comparison CCM.D-K2 'comparison of liquid density standards' was carried out piloted by the PTB. The aim was to compare the results of the density determination by the participating laboratories to support entries to the CMC tables in this sub-field. To provide further laboratories the possibility to support their entries to the CMC tables at the meeting of the EUROMET Working Group on Density in 2007 this comparison was agreed on. BEV (Austria) organized the comparison supported by the PTB (Germany). For the comparison samples of pentadecane, water, tetrachloroethylene and of an oil of high viscosity were measured in the temperature range from 5 °C to 60 °C at atmospheric pressure by hydrostatic weighing. The measurements were completed in 2008. The reference values of the first reports based on the draft of the CCM.D-K2. After the official publication of the CCM.D-K2 the reference values were recalculated and the report was finalised in 2015. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  20. N Reactor RELAP5 model benchmark comparisons

    SciTech Connect

    Fletcher, C.D.; Bolander, M.A.

    1988-02-01

    This report documents work performed at the Idaho National Engineering Laboratory (INEL) in support of Westinghouse Hanford Company safety analyses for the N Reactor. The portion of the work reported here includes comparisons of RELAP5/MOD2-calculated data with measured plant data for: (1) a plant trip reactor transient from full power operation; and (2) a hot dump test performed prior to plant startup. These qualitative comparisons are valuable because they provide an indication of the capabilities of the RELAP5/MOD2 code to simulate operational and blowdonw transients in the N Reactor. 9 refs., 12 figs., 4 tabs.

  1. Parallel mergs sort using comparison matrices. I

    SciTech Connect

    Romm, Y.E.

    1995-05-01

    The topics discussed in this paper are connected with internal merge sorting by a key (in short, M-sorting or M-sort). Originally developed by von Neumann, this is one of the first sorting methods. It still remains one of the fastest, involving Nlog{sub 2}N comparisons. The purpose of our article is to demonstrate the use of comparison matrices (CMs) for merging in M-sort. While preserving the known advantages of the sequential implementation of M-sort. CMs ensure more efficient use of main memory (one of the known weaknesses of M-sort is its large memory requirements) and effective parallelizability.

  2. On relative distortion in fingerprint comparison.

    PubMed

    Kalka, Nathan D; Hicklin, R Austin

    2014-11-01

    When fingerprints are deposited, non-uniform pressure in conjunction with the inherent elasticity of friction ridge skin often causes linear and non-linear distortions in the ridge and valley structure. The effects of these distortions must be considered during analysis of fingerprint images. Even when individual prints are not notably distorted, relative distortion between two prints can have a serious impact on comparison. In this paper we discuss several metrics for quantifying and visualizing linear and non-linear fingerprint deformations, and software tools to assist examiners in accounting for distortion in fingerprint comparisons.

  3. Metrics for comparison of crystallographic maps

    SciTech Connect

    Urzhumtsev, Alexandre; Afonine, Pavel V.; Lunin, Vladimir Y.; Terwilliger, Thomas C.; Adams, Paul D.

    2014-10-01

    Numerical comparison of crystallographic contour maps is used extensively in structure solution and model refinement, analysis and validation. However, traditional metrics such as the map correlation coefficient (map CC, real-space CC or RSCC) sometimes contradict the results of visual assessment of the corresponding maps. This article explains such apparent contradictions and suggests new metrics and tools to compare crystallographic contour maps. The key to the new methods is rank scaling of the Fourier syntheses. The new metrics are complementary to the usual map CC and can be more helpful in map comparison, in particular when only some of their aspects, such as regions of high density, are of interest.

  4. A Comparison of Information System Development Methodologies.

    DTIC Science & Technology

    1987-12-01

    r Dll -ft lU 5? R COMPARISON OF INFORMATION SYSTEM DEYELOPMENT IETHOOOLOGXES(U) AIR FORCE ]NST OF TECH IGHMT-PRTTERSON RFI 0ON SCHOOL OF SYSTEMS AND...DEVELOPMENT METHODOLJOGI ES THESIS Steven D. Branch Captain, USAF AFIT/GI R /LSR/87D-1 ...................i TON STTEM " A Approyed for public relecog4i...AFIT/GIR/LSR/87D- 1 A COMPARISON OF INFORMATION SYSTEM - DEVELOPMENT METHODOLOGIES .> THESIS ’ r ~( D~9ii Captain, USAF% AFIT/GIR/LSR/8?D-1 FE 0

  5. Systematic Comparison of Operating Reserve Methodologies: Preprint

    SciTech Connect

    Ibanez, E.; Krad, I.; Ela, E.

    2014-04-01

    Operating reserve requirements are a key component of modern power systems, and they contribute to maintaining reliable operations with minimum economic impact. No universal method exists for determining reserve requirements, thus there is a need for a thorough study and performance comparison of the different existing methodologies. Increasing penetrations of variable generation (VG) on electric power systems are posed to increase system uncertainty and variability, thus the need for additional reserve also increases. This paper presents background information on operating reserve and its relationship to VG. A consistent comparison of three methodologies to calculate regulating and flexibility reserve in systems with VG is performed.

  6. Comparison of IR and Visible Cloud Imagers

    NASA Astrophysics Data System (ADS)

    Mandeville, W.; McLaughlin, T.; Bygren, S.; Randell, C.

    This paper presents a comparison between the Infrared Cloud Imager (IRCI) used at Ground-based Electro-Optical Deep Space Surveillance (GEODSS) sites and the Visible Cloud Imager (VCI) developed using a COTS all-sky camera. The cloud imagers are used to create exclusion maps for GEODSS observations based on detected cloud locations. Excluding observation attempts in obscured areas of the sky is done to improve the allocation of sensor resources. Estimates are made for atmospheric extinction across the entire sky by comparing known star brightness to measured brightness. Data for the comparison were collected at the GEODSS test site located in Yoder, Colorado for a variety of cloud conditions.

  7. Inner Radiation Belt Data / Model Comparisons

    NASA Astrophysics Data System (ADS)

    Guild, Timothy; O'Brien, Paul; Selesnick, Richard

    We present detailed comparisons of a time-dependent inner radiation belt model with proton observations made by a variety of in-situ spacecraft during solar cycle 23. The recently-developed model (Selesnick et al., 2007) computes proton intensities as a function of time and of the three adiabatic invariants in the inner belt, which we convert to the observable count rate at the location of the satellite by using a nominal instrument response function. These comparisons and initial data-assimilation efforts suggest that the model performance can be improved especially during intervals containing unmodeled processes such as trapped proton losses during geomagnetic storms.

  8. Inner Radiation Belt Data / Model Comparisons

    NASA Astrophysics Data System (ADS)

    Guild, T. B.; O'Brien, T. P.; Selesnick, R.; Looper, M.

    2008-12-01

    We present detailed comparisons of a time-dependent inner radiation belt model with in-situ proton observations made by a variety of spacecraft during solar cycle 23. The recently-developed model (Selesnick et al., 2007) computes proton intensities as a function of time and of the three adiabatic invariants in the inner belt, which we convert to the observable count rate in a detector at the location of the satellite by using instrument response functions. These comparisons and initial data-assimilation efforts suggest that the model performance can be improved especially during injections of solar protons, and at L-shells above 2.

  9. Drift Eliminating Designs for Non-Simultaneous Comparison Calibrations.

    PubMed

    Doiron, Ted

    1993-01-01

    The effects of drift on calibrations carried out by comparison have been studied at the National Institute of Standards and Technology for many years, and a number of strategies have been introduced to combat these effects. One strategy, the use of comparison designs which are inherently immune to linear drift, was developed specifically for mass comparison measurements. These techniques, developed for simultaneous comparisons, are extended to the case of non-simultaneous comparisons, such as gage block calibrations, where each artifact is measured separately, and the comparison is made mathematically from the individual measurements.

  10. Drift Eliminating Designs for Non-Simultaneous Comparison Calibrations

    PubMed Central

    Doiron, Ted

    1993-01-01

    The effects of drift on calibrations carried out by comparison have been studied at the National Institute of Standards and Technology for many years, and a number of strategies have been introduced to combat these effects. One strategy, the use of comparison designs which are inherently immune to linear drift, was developed specifically for mass comparison measurements. These techniques, developed for simultaneous comparisons, are extended to the case of non-simultaneous comparisons, such as gage block calibrations, where each artifact is measured separately, and the comparison is made mathematically from the individual measurements. PMID:28053468

  11. Analysis of Paired Comparison Data Using Mx

    ERIC Educational Resources Information Center

    Tsai, Rung-Ching; Wu, Tsung-Lin

    2004-01-01

    By postulating that the random utilities associated with the choice options follow a multivariate normal distribution, Thurstonian models (Thurstone, 1927) provide a straightforward representation of paired comparison data. The use of Monte Carlo Expectation-Maximization (MCEM) algorithms and limited information approaches have been proposed to…

  12. Comparison of Classical and Quantum Mechanical Uncertainties.

    ERIC Educational Resources Information Center

    Peslak, John, Jr.

    1979-01-01

    Comparisons are made for the particle-in-a-box, the harmonic oscillator, and the one-electron atom. A classical uncertainty principle is derived and compared with its quantum-mechanical counterpart. The results are discussed in terms of the statistical interpretation of the uncertainty principle. (Author/BB)

  13. Measurement of Social Development: An International Comparison

    ERIC Educational Resources Information Center

    Ray, Amal Kanti

    2008-01-01

    PQLI and HDI are the two most popular measures of development, besides per capita income. Over the years, PQLI appears to be not much in use for regional comparisons, especially after the introduction of HDI. While PQLI considers only the physical variables--adult literacy, life expectancy at birth and infant survival rate, HDI has life expectancy…

  14. Multivariate normative comparisons using an aggregated database.

    PubMed

    Agelink van Rentergem, Joost A; Murre, Jaap M J; Huizenga, Hilde M

    2017-01-01

    In multivariate normative comparisons, a patient's profile of test scores is compared to those in a normative sample. Recently, it has been shown that these multivariate normative comparisons enhance the sensitivity of neuropsychological assessment. However, multivariate normative comparisons require multivariate normative data, which are often unavailable. In this paper, we show how a multivariate normative database can be constructed by combining healthy control group data from published neuropsychological studies. We show that three issues should be addressed to construct a multivariate normative database. First, the database may have a multilevel structure, with participants nested within studies. Second, not all tests are administered in every study, so many data may be missing. Third, a patient should be compared to controls of similar age, gender and educational background rather than to the entire normative sample. To address these issues, we propose a multilevel approach for multivariate normative comparisons that accounts for missing data and includes covariates for age, gender and educational background. Simulations show that this approach controls the number of false positives and has high sensitivity to detect genuine deviations from the norm. An empirical example is provided. Implications for other domains than neuropsychology are also discussed. To facilitate broader adoption of these methods, we provide code implementing the entire analysis in the open source software package R.

  15. Reasoning by Analogy in Solving Comparison Problems.

    ERIC Educational Resources Information Center

    English, Lyn D.

    1998-01-01

    Investigates 10-year-old children's abilities to reason by analogy in solving addition and subtraction comparison problems involving unknown compare sets and unknown reference sets. Children responded in a consistent manner to the tasks involving the basic addition problems, indicating substantial relational knowledge of these but responded in an…

  16. Photographic catalog of selected planetary size comparisons

    NASA Technical Reports Server (NTRS)

    Meszaros, S. P.

    1985-01-01

    Photographs taken by NASA spacecraft, and cartographic products based on these photos, are used to illustrate size comparisons of the planets and moons of the solar system. Global views and prominent geographical features are depicted at the same scale, allowing size relationships to be studied visually.

  17. A Comparison of Software Schedule Estimators

    DTIC Science & Technology

    1990-09-01

    and Limitations ............................... 3 II. Literature Review ..................................... 5 Software Development Life Cycle...94 V List of ieu Figure Page 1. An Example Of System Development Reviews And Audits ...... 8 2. Life Cycle Estimate Comparison...missing a measurement that is required to run the model. 4 II. Literature Review The field of software development is of interest to a wide variety of

  18. Planned Contrasts: An Overview of Comparison Methods.

    ERIC Educational Resources Information Center

    Chatham, Kathy

    Contrasts or comparisons can be used to investigate specific differences between means. Contrasts, as explained by B. Thompson (1985, 1994) are coding vectors that mathematically express hypotheses. The most basic categories of contrasts are planned and unplanned. The purpose of this paper is to explain the relative advantages of using planned…

  19. Do Young Children Understand Relative Value Comparisons?

    PubMed Central

    Benenson, Joyce F.; Markovits, Henry; Whitmore, Bjorn; Van, Christophe; Margolius, Sara; Wrangham, Richard W.

    2015-01-01

    Many forms of judgments, such as those used in economic games or measures of social comparison, require understanding relative value, as well as the more complex ability to make comparisons between relative values. To examine whether young children can accurately compare relative values, we presented children 4 to 7 years with simple judgments of relative value in two scenarios. Children then were asked to compare the relative values in the two scenarios. Results show that even the youngest children downgraded evaluations of a reward when another has a larger amount, indicating the ability to make relative value judgments. When asked to compare relative values however, only the oldest children were able to make these comparisons consistently. We then extended this analysis to economic game performance. Specifically, previous results using economic games suggest that younger children are more generous than older ones. We replicate this result, and then show that a simple change in procedure, based on the initial study, is sufficient to change young children’s choices. Our results strongly suggest that conclusions regarding young children’s pro-social motives based on relative value comparisons should be viewed cautiously. PMID:25875949

  20. Research Techniques for Phonetic Comparison of Languages.

    ERIC Educational Resources Information Center

    Delattre, Pierre

    1963-01-01

    This is the first in a series of articles on general phonetic characteristics of American English. Language research techniques of spectrographic analysis, spectrographic synthesis, articulatory motion-picture study, and statistical calculation are briefly described. Thirty-five areas of phonetic difference for comparison of English to Spanish,…

  1. A comparison of Monte Carlo generators

    SciTech Connect

    Golan, Tomasz

    2015-05-15

    A comparison of GENIE, NEUT, NUANCE, and NuWro Monte Carlo neutrino event generators is presented using a set of four observables: protons multiplicity, total visible energy, most energetic proton momentum, and π{sup +} two-dimensional energy vs cosine distribution.

  2. Multivariate normative comparisons using an aggregated database

    PubMed Central

    Murre, Jaap M. J.; Huizenga, Hilde M.

    2017-01-01

    In multivariate normative comparisons, a patient’s profile of test scores is compared to those in a normative sample. Recently, it has been shown that these multivariate normative comparisons enhance the sensitivity of neuropsychological assessment. However, multivariate normative comparisons require multivariate normative data, which are often unavailable. In this paper, we show how a multivariate normative database can be constructed by combining healthy control group data from published neuropsychological studies. We show that three issues should be addressed to construct a multivariate normative database. First, the database may have a multilevel structure, with participants nested within studies. Second, not all tests are administered in every study, so many data may be missing. Third, a patient should be compared to controls of similar age, gender and educational background rather than to the entire normative sample. To address these issues, we propose a multilevel approach for multivariate normative comparisons that accounts for missing data and includes covariates for age, gender and educational background. Simulations show that this approach controls the number of false positives and has high sensitivity to detect genuine deviations from the norm. An empirical example is provided. Implications for other domains than neuropsychology are also discussed. To facilitate broader adoption of these methods, we provide code implementing the entire analysis in the open source software package R. PMID:28267796

  3. Tukey-Like Pairwise Comparisons among Proportions.

    ERIC Educational Resources Information Center

    Williams, Richard H.

    1992-01-01

    A QuickBASIC microcomputer program for conducting Tukey-like pairwise comparisons on "k" independent sample proportions is described. The program can accommodate applications involving equal or unequal sample sizes. Studentized range values are computed and displayed on a computer monitor, each of which represents a simple comparison…

  4. "Units of Comparison" across Languages, across Time

    ERIC Educational Resources Information Center

    Thomas, Margaret

    2009-01-01

    Lardiere's keynote article adverts to a succession of "units of comparison" that have been employed in the study of cross-linguistic differences, including mid-twentieth-century structural patterns, generative grammar's parameters, and (within contemporary Minimalism) features. This commentary expands on the idea of units of cross-linguistic…

  5. Inter-comparison of subglacial hydrological models

    NASA Astrophysics Data System (ADS)

    de Fleurian, Basile; Werder, Mauro

    2016-04-01

    The recent emergence of a number of subglacial hydrological models allows us to obtain theoretical insights on basal processes; for instance on the coupling between water pressure and the sliding of glaciers. In ice-flow models, it is relatively clear what the simulated physics ought to be. Conversely, the physical processes incorporated into subglacial hydrology models are diverse as it is yet unclear which ones are of relevance for a particular setting. An inter-comparison of hydrology models will therefore need a somewhat different approach to the one used in the many ice-flow model inter-comparisons (EISMINT, ISMIP, etc.). Here, we present a set of experiments that will allow the comparison of the behavior of different hydrology models. The design of the benchmark aims at allowing the participation of a wide range of models based on different physical approaches. We aim at evaluating the models with a focus on the effective pressure which has the most impact on the dynamics of glaciers. The aim of this inter-comparison is to provide modellers with the necessary data to make an informed decision on which subglacial hydrology model to use for a particular study.

  6. Interview Design for Ratio Comparison Tasks

    ERIC Educational Resources Information Center

    Alatorre, Silvia; Figueras, Olimpia

    2003-01-01

    In this article, which is part of an ongoing research, a classification is proposed for ratio comparison problems, according to their context, their quantity type, and their numerical structure. Deriving from this classification, an interview protocol was designed, and guidelines for the interpretation of answers into strategies were decided. A…

  7. COMPARISONS AND CONTRASTS AMONG DIFFERENT SCALED ASSESSMENTS

    EPA Science Inventory

    A comparison of a regional (multi-state) and local (multi-county) scale assessment was done to evaluate similarities and differences in the collection, analysis, and interpretation of landscape data. The study areas included EP A Region 3 a11d a sub-region spanning North and Sout...

  8. Interlaboratory comparison of olfactometry in Japan.

    PubMed

    Higuchi, T; Masuda, J

    2004-01-01

    In 2000, 2001, and 2002, interlaboratory comparison of olfactometry was carried out in order to collect basic data for the establishment of a quality control procedure and the determination of quality criteria for the triangular odour bag method. In 2000, interlaboratory comparison was conducted by using a measurement method for samples taken at smoke stacks. On the other hand, the measurement method for samples taken at boundary lines was used for interlaboratory comparison in 2001. A total of seven olfactometry laboratories in Japan participated in each test, and mean values, repeatability standard deviations, reproducibility standard deviations, and standard deviations under intermediate conditions of detection threshold of ethyl acetate were calculated from the results. These values can be used in a quality control process of olfactometry. In 2002, interlaboratory comparison was carried out by using a measurement method for samples taken at smoke stacks. A total of 137 olfactometry laboratories in Japan participated in the test, and 69% of them lay within the permissible range of the odour index.

  9. Cross-Cultural Comparison of Cognitive Consistency.

    ERIC Educational Resources Information Center

    Khokhlov, Nikolai E.; Gonzalez E. John

    1973-01-01

    A comparison of cognitive consistency was conducted across two cultural groups. Forty-five American subjects in Southern California and 45 subjects in Northern Greece responded to a questionnaire written in their native language and which contained three classical paradigms for balance theory. It was hypothesized that significant differences in…

  10. Teaching Creativity: A Comparison of Two Techniques

    ERIC Educational Resources Information Center

    Rosenthal, Doreen A.; And Others

    1977-01-01

    A comparison was made of the effects of a topic-centered lecture and a skill-centered practice session on creativity, as measured by two tests of divergent thinking. Results were interpreted as supporting De Bono's claim that thinking skills are best taught by focusing on techniques which, with practice, can be deliberately applied to a number of…

  11. ABL and BAM Friction Analysis Comparison

    DOE PAGES

    Warner, Kirstin F.; Sandstrom, Mary M.; Brown, Geoffrey W.; ...

    2014-12-29

    Here, the Integrated Data Collection Analysis (IDCA) program has conducted a proficiency study for Small-Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here is a comparison of the Alleghany Ballistic Laboratory (ABL) friction data and Bundesanstalt fur Materialforschung und -prufung (BAM) friction data for 19 HEM and military standard explosives.

  12. Social Comparison of Pay and Inequity Theory.

    ERIC Educational Resources Information Center

    Judd, Ben

    Inequity theory differs from social exchange theory in its analysis of a worker's reaction to pay by asserting that effects on work performance caused by high or low pay are due to social comparison of fairness rather than principles of direct exchange, such as reciprocity and power. The present experiment held piece-rate pay constant at two…

  13. The discovery and comparison of symbolic magnitudes.

    PubMed

    Chen, Dawn; Lu, Hongjing; Holyoak, Keith J

    2014-06-01

    Humans and other primates are able to make relative magnitude comparisons, both with perceptual stimuli and with symbolic inputs that convey magnitude information. Although numerous models of magnitude comparison have been proposed, the basic question of how symbolic magnitudes (e.g., size or intelligence of animals) are derived and represented in memory has received little attention. We argue that symbolic magnitudes often will not correspond directly to elementary features of individual concepts. Rather, magnitudes may be formed in working memory based on computations over more basic features stored in long-term memory. We present a model of how magnitudes can be acquired and compared based on BARTlet, a representationally simpler version of Bayesian Analogy with Relational Transformations (BART; Lu, Chen, & Holyoak, 2012). BARTlet operates on distributions of magnitude variables created by applying dimension-specific weights (learned with the aid of empirical priors derived from pre-categorical comparisons) to more primitive features of objects. The resulting magnitude distributions, formed and maintained in working memory, are sensitive to contextual influences such as the range of stimuli and polarity of the question. By incorporating psychological reference points that control the precision of magnitudes in working memory and applying the tools of signal detection theory, BARTlet is able to account for a wide range of empirical phenomena involving magnitude comparisons, including the symbolic distance effect and the semantic congruity effect. We discuss the role of reference points in cognitive and social decision-making, and implications for the evolution of relational representations.

  14. Cross-Cultural Comparisons: The Validity of Assessment by Indices of Factor Comparison.

    ERIC Educational Resources Information Center

    Eysenck, Hans J.

    1986-01-01

    Considers the cross-cultural consistency of personality inventories, concluding that it is justifiable to use the scale of the Eysenck Personality Questionnaire for comparisons within and between different countries. (Author/LHW)

  15. Supplementary comparison EURAMET.L-S22, calibration of gauge blocks by mechanical comparison

    NASA Astrophysics Data System (ADS)

    Lewis, Andrew; Lillepea, Lauri; Matus, Michael; Prieto, Emilio; Ačko, Bojan; Svendsmark Hansen, Maria; Turner, Paul; Testa, Nicola; Daoud, Anouar; Montassar, Chekir; Švedova, Larisa; Hald, Jan; Gaidamovičiūtė, Lilijana; Bajic, Gordana

    2017-01-01

    In October 2012, the EURAMET Technical Committee for Length, TC-L, decided upon a supplementary comparison on gauge block measurements by mechanical comparison, numbered EURAMET.L-S22, with the Danish Technological Institute (DTI) as the pilot laboratory, assisted by NPL (Andrew Lewis), which would provide a link to CCL-K1. The comparison was registered in February 2013, artefact circulation starts in June 2013 and ended in September 2014. Eight gauge blocks were calibrated using a five point measurement. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  16. Positive identification by X-rays bone trabeculae comparison.

    PubMed

    Quatrehomme, Gérald; Biglia, Elodie; Padovani, Bernard; du Jardin, Philippe; Alunni, Véronique

    2014-12-01

    Positive (certain, absolute) identification of human remains needs a scientific comparison between ante mortem and post-mortem biologic features, as fingerprint, odontological, radiological or DNA comparisons. X-rays comparison has been extensively used, usually comparing some peculiarities such as outlines of the bones, degenerative evolution or pathological conditions. Trabeculae comparisons are sparsely underlined in the forensic literature. We report on a case of decomposed body where fingerprint, DNA and odontological comparisons were not possible. After dissecting the leg and preparing the bones, comparison of ante mortem and postmortem trabeculae led to a positive identification. It was observed that tens of radiolucencies and radiodensities drawn by the trabeculae were useful for comparison, within a very small part of bone. In the case reported here the positive identity could have been assessed only by the comparison of the first metatarsal. The statement of positive identification needs scientific criteria that will be discussed in this article.

  17. 16 CFR 233.1 - Former price comparisons.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... DECEPTIVE PRICING § 233.1 Former price comparisons. (a) One of the most commonly used forms of bargain..., not for the purpose of establishing a fictitious higher price on which a deceptive comparison might...

  18. 16 CFR 233.1 - Former price comparisons.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... DECEPTIVE PRICING § 233.1 Former price comparisons. (a) One of the most commonly used forms of bargain..., not for the purpose of establishing a fictitious higher price on which a deceptive comparison might...

  19. 16 CFR 233.1 - Former price comparisons.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... DECEPTIVE PRICING § 233.1 Former price comparisons. (a) One of the most commonly used forms of bargain..., not for the purpose of establishing a fictitious higher price on which a deceptive comparison might...

  20. 30 CFR 1206.155 - Accounting for comparison.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Accounting for comparison. 1206.155 Section... INTERIOR Natural Resources Revenue PRODUCT VALUATION Federal Gas § 1206.155 Accounting for comparison. (a... with § 1206.152 of this subpart. (b) The requirement for accounting for comparison contained in...

  1. 30 CFR 1206.155 - Accounting for comparison.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Accounting for comparison. 1206.155 Section... RESOURCES REVENUE PRODUCT VALUATION Federal Gas § 1206.155 Accounting for comparison. (a) Except as provided... with § 1206.152 of this subpart. (b) The requirement for accounting for comparison contained in...

  2. 30 CFR 1206.155 - Accounting for comparison.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Accounting for comparison. 1206.155 Section... RESOURCES REVENUE PRODUCT VALUATION Federal Gas § 1206.155 Accounting for comparison. (a) Except as provided... with § 1206.152 of this subpart. (b) The requirement for accounting for comparison contained in...

  3. 30 CFR 1206.155 - Accounting for comparison.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Accounting for comparison. 1206.155 Section... RESOURCES REVENUE PRODUCT VALUATION Federal Gas § 1206.155 Accounting for comparison. (a) Except as provided... with § 1206.152 of this subpart. (b) The requirement for accounting for comparison contained in...

  4. The Performance versus Ability Distinction Following Social Comparison Feedback

    ERIC Educational Resources Information Center

    Buckingham, Justin T.; LeBeau, Lavonia Smith; Klein, William M. P.

    2011-01-01

    Previous research suggests that self-evaluations can be influenced by social comparison feedback. The present study tested whether social comparison feedback has stronger effects on self-evaluations of performance than ability. Participants received social comparison feedback indicating that they had performed above or below average. In addition…

  5. 30 CFR 206.155 - Accounting for comparison.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Accounting for comparison. 206.155 Section 206... MANAGEMENT PRODUCT VALUATION Federal Gas § 206.155 Accounting for comparison. (a) Except as provided in... subpart. (b) The requirement for accounting for comparison contained in the terms of leases will govern...

  6. Comparison versus Contrast: Task Specifics Affect Category Acquisition

    ERIC Educational Resources Information Center

    Ankowski, Amber A.; Vlach, Haley A.; Sandhofer, Catherine M.

    2013-01-01

    A large literature has documented that comparison and contrast lead to better performance in a variety of tasks. However, studies of comparison and contrast present contradictory conclusions as to when and how these processes benefit learners. Across four studies, we examined how the specifics of the comparison and contrast task affect performance…

  7. Learning through Case Comparisons: A Meta-Analytic Review

    ERIC Educational Resources Information Center

    Alfieri, Louis; Nokes-Malach, Timothy J.; Schunn, Christian D.

    2013-01-01

    Over the past 20 years, there has been much research on how people learn from case comparisons. This work has implemented comparison activities in a variety of different ways across a wide range of laboratory and classroom contexts. In an effort to assess the overall effectiveness of case comparisons across this diversity of implementation and…

  8. Social comparison, personal relative deprivation, and materialism.

    PubMed

    Kim, Hyunji; Callan, Mitchell J; Gheorghiu, Ana I; Matthews, William J

    2016-11-23

    Across five studies, we found consistent evidence for the idea that personal relative deprivation (PRD), which refers to resentment stemming from the belief that one is deprived of deserved outcomes compared to others, uniquely contributes to materialism. In Study 1, self-reports of PRD positively predicted materialistic values over and above socioeconomic status, personal power, self-esteem, and emotional uncertainty. The experience of PRD starts with social comparison, and Studies 2 and 3 found that PRD mediated the positive relation between a tendency to make social comparisons of abilities and materialism. In Study 4, participants who learned that they had less (vs. similar) discretionary income than people like them reported a stronger desire for more money relative to donating more to charity. In Study 5, during a windfall-spending task, participants higher in PRD spent more on things they wanted relative to other spending categories (e.g., paying off debts).

  9. Ontology for Genome Comparison and Genomic Rearrangements

    PubMed Central

    Flanagan, Keith; Stevens, Robert; Pocock, Matthew; Lee, Pete

    2004-01-01

    We present an ontology for describing genomes, genome comparisons, their evolution and biological function. This ontology will support the development of novel genome comparison algorithms and aid the community in discussing genomic evolution. It provides a framework for communication about comparative genomics, and a basis upon which further automated analysis can be built. The nomenclature defined by the ontology will foster clearer communication between biologists, and also standardize terms used by data publishers in the results of analysis programs. The overriding aim of this ontology is the facilitation of consistent annotation of genomes through computational methods, rather than human annotators. To this end, the ontology includes definitions that support computer analysis and automated transfer of annotations between genomes, rather than relying upon human mediation. PMID:18629137

  10. Using Dali for structural comparison of proteins.

    PubMed

    Holm, Liisa; Kääriäinen, Sakari; Wilton, Chris; Plewczynski, Dariusz

    2006-07-01

    The Dali program is widely used for carrying out automatic comparisons of protein structures determined by X-ray crystallography or NMR. The most familiar version is the Dali server, which performs a database search comparing a query structure supplied by the user against the database of known structures (PDB) and returns the list of structural neighbors by e-mail. The more recently introduced DaliLite server compares two structures against each other and visualizes the result interactively. The Dali database is a structural classification based on precomputed all-against-all structural similarities within the PDB. The resulting hierarchical classification can be browsed on the Web and is linked to protein sequence classification resources. All Dali resources use an identical algorithm for structure comparison. Users may run Dali using the Web, or the program may be downloaded to be run locally on Linux computers.

  11. Visual comparison testing of automotive paint simulation

    NASA Astrophysics Data System (ADS)

    Meyer, Gary; Fan, Hua-Tzu; Seubert, Christopher; Evey, Curtis; Meseth, Jan; Schnackenberg, Ryan

    2015-03-01

    An experiment was performed to determine whether typical industrial automotive color paint comparisons made using real physical samples could also be carried out using a digital simulation displayed on a calibrated color television monitor. A special light booth, designed to facilitate evaluation of the car paint color with reflectance angle, was employed in both the real and virtual color comparisons. Paint samples were measured using a multi-angle spectrophotometer and were simulated using a commercially available software package. Subjects performed the test quicker using the computer graphic simulation, and results indicate that there is only a small difference between the decisions made using the light booth and the computer monitor. This outcome demonstrates the potential of employing simulations to replace some of the time consuming work with real physical samples that still characterizes material appearance work in industry.

  12. Robot Trajectories Comparison: A Statistical Approach

    PubMed Central

    Ansuategui, A.; Arruti, A.; Susperregi, L.; Yurramendi, Y.; Jauregi, E.; Lazkano, E.; Sierra, B.

    2014-01-01

    The task of planning a collision-free trajectory from a start to a goal position is fundamental for an autonomous mobile robot. Although path planning has been extensively investigated since the beginning of robotics, there is no agreement on how to measure the performance of a motion algorithm. This paper presents a new approach to perform robot trajectories comparison that could be applied to any kind of trajectories and in both simulated and real environments. Given an initial set of features, it automatically selects the most significant ones and performs a statistical comparison using them. Additionally, a graphical data visualization named polygraph which helps to better understand the obtained results is provided. The proposed method has been applied, as an example, to compare two different motion planners, FM2 and WaveFront, using different environments, robots, and local planners. PMID:25525618

  13. 33alloy: comparison between experiment and simulation

    SciTech Connect

    Kramer, M J; Mendelev, M I; Asta, M

    2014-04-22

    We report data on the structure of liquid Al and an Al67Mg33 alloy obtained from state-of-the-art X-ray diffraction experiments and ab initio molecular dynamics (AIMD) simulations. To facilitate a direct comparison between these data, we develop a method to elongate the AIMD pair correlation function in order to obtain reliable AIMD structure factors. The comparison reveals an appreciable level of discrepancy between experimental and AIMD liquid structures, with the latter being consistently more ordered than the former at the same temperature. The discrepancy noted in this study is estimated to have significant implications for simulation-based calculations of liquid transport properties and solid–liquid interface kinetic properties.

  14. Metrics for comparison of crystallographic maps

    DOE PAGES

    Urzhumtsev, Alexandre; Afonine, Pavel V.; Lunin, Vladimir Y.; ...

    2014-10-01

    Numerical comparison of crystallographic contour maps is used extensively in structure solution and model refinement, analysis and validation. However, traditional metrics such as the map correlation coefficient (map CC, real-space CC or RSCC) sometimes contradict the results of visual assessment of the corresponding maps. This article explains such apparent contradictions and suggests new metrics and tools to compare crystallographic contour maps. The key to the new methods is rank scaling of the Fourier syntheses. The new metrics are complementary to the usual map CC and can be more helpful in map comparison, in particular when only some of their aspects,more » such as regions of high density, are of interest.« less

  15. Comparison of fugitive coal dust sizing techniques

    SciTech Connect

    Meyer, J.H.; Lenkevich, M.J.; Davis, E.A.

    1984-10-01

    In conjunction with a field-test program to measure fugitive dust emissions from a rotary railcar dumper, several techniques for particle sizing were compared. The comparison experiments were done at Potomac Electric Power Company's coal-fired generating station at Morgantown, Maryland with support of the Maryland Power Plant Siting Program. Three cascade impactor instruments were compared, including a quartz-crystal microbalance. In addition, two other methods, a 40mm millipore filter operated isokinetically and a rotary arm impactor, were used to obtain particulate samples for optical sizing from calibrated microphotographs. The microphotographs also provided information on coal-particle shape, aggregation, and friability. An aerodynamic particle sizer based on laser velocimetry was also used during one of three comparison tests. Two particle resuspension and sizing methods were attempted but abandoned due to experimental difficulties. Coal particle size and cumulative mass-fraction size distributions for the various sampling techniques were compared.

  16. Inter-species comparisons of carcinogenicity.

    PubMed Central

    Purchase, I. F.

    1980-01-01

    The carcinogenicity of 250 chemicals in 2 species, usually the rat and the mouse, was obtained from the published literature through 3 independent sources. Of the 250 compounds listed, 38% were non-carcinogenic in both rats and mice, and 44% were carcinogenic in both species. A total of 43 compounds had different results in the two species, 21 (8%) being carcinogenic in mice only, 17 (7%) in rats only and 5 (2%) having differing results from other species. A comparison of the major target organs affected by chemicals carcinogenic in both species revealed that 64% of the chemicals studied produced cancer at the same site. This comparison of carcinogenic activity in 2 species suggests that extrapolation from results in a single-animal study to man may be subject to substantial errors. PMID:7387835

  17. Are all Linear Paired Comparison Models Equivalent

    DTIC Science & Technology

    1990-09-01

    Previous authors (Jackson and Fleckenstein 1957, Mosteller 1958, Noether 1960) have found that different models of paired comparisons data lead to simi...ponential distribution with a location parameter (Mosteller 1958, Noether 1960). Formal statements describing the limiting behavior of the gamma...that are not convolu- tion type linear models (the uniform model considered by Smith (1956), Mosteller (1958), Noether (1960)) and other convolution

  18. Comparison of Dam Breach Parameter Estimators

    DTIC Science & Technology

    2008-01-01

    from a large storm in 1975 (CEATI). The dam was constructed of a clay core containing shale. The upstream and downstream fill was homogeneous earth ...Comparison of Dam Breach Parameter Estimators D. Michael Gee1 1 Senior Hydraulic Engineer, Corps of Engineers Hydrologic Engineering...Center, 609 2nd St., Davis, CA 95616; email: michael.gee@usace.army.mil. ABSTRACT Analytical techniques for the estimation of dam breach

  19. An International Comparison of Military Compensation.

    DTIC Science & Technology

    1980-12-01

    for public release; distribution unlimited An International Comparison Of Military Compensation by Myron Clifford Oyloe Major, United States Army B.S...COMPENSATION by Myron Clifford Oyloe Major, United States Army B.S. North Dakota State University, 1967 December 1980 Thesis Advisor: Ragnhild Sohlberg...V) IMyron Clifford /oyloe IMajor, United States Army S. PERFORMING ORG"NI2ATIONMNAME9 AND A0G1RE68 10. PROGRAM ELEMENT. PROJECT. TASK Naval

  20. Comparison of two dissimilar modal identification techniques

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S.; Schenk, Axel; Niedbal, Norbert; Klusowski, Erhard

    1992-01-01

    Recent laboratory results using a refined phase resonance method and the eigensystem realization algorithm on the same test structure are reported. These methods are dissimilar modal identification techniques suitable for future large spacecraft. The theory, application approach, and results obtained for each technique are summarized and compared. Although both methods worked well in this investigation, significant differences occurred in some identified mode shapes. Comparison of independently derived modal parameters provides the means for disclosing such discrepancies in flight projects.

  1. Rocket/Nimbus Sounder Comparison (RNSC)

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The experimental results for radiance and temperature differences in the Wallops Island comparisons indicate that the differences between satellite and rocket systems are of the same order of magnitude as the differences among the various satellite and rocket sounders. The Arcasondes produced usable data to about 50 km, while the Datasondes require design modification. The SIRS and IRIS soundings provided usable data to 30 mb; extension of these soundings was also investigated.

  2. Comparison of US Blast Design Guidance Documents

    DTIC Science & Technology

    2010-07-01

    shear reinforcing steel so that the sum of the concrete and steel shear strengths is equal to the equivalent reaction...rev. 1, SBEDS “calculates the required area of shear reinforcing steel so that the sum of the concrete and steel shear strengths is equal to the...greater than 2-degrees typically have fixed supports. 5 In comparison, SBEDS calculates the direct shear capacity of reinforced concrete

  3. KEY COMPARISON: Final report on CCQM-K69 key comparison: Testosterone glucuronide in human urine

    NASA Astrophysics Data System (ADS)

    Liu, Fong-Ha; Mackay, Lindsey; Murby, John

    2010-01-01

    The CCQM-K69 key comparison of testosterone glucuronide in human urine was organized under the auspices of the CCQM Organic Analysis Working Group (OAWG). The National Measurement Institute Australia (NMIA) acted as the coordinating laboratory for the comparison. The samples distributed for the key comparison were prepared at NMIA with funding from the World Anti-Doping Agency (WADA). WADA granted the approval for this material to be used for the intercomparison provided the distribution and handling of the material were strictly controlled. Three national metrology institutes (NMIs)/designated institutes (DIs) developed reference methods and submitted data for the key comparison along with two other laboratories who participated in the parallel pilot study. A good selection of analytical methods and sample workup procedures was displayed in the results submitted considering the complexities of the matrix involved. The comparability of measurement results was successfully demonstrated by the participating NMIs. Only the key comparison data were used to estimate the key comparison reference value (KCRV), using the arithmetic mean approach. The reported expanded uncertainties for results ranged from 3.7% to 6.7% at the 95% level of confidence and all results agreed within the expanded uncertainty of the KCRV. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  4. Goals and Social Comparisons Promote Walking Behavior.

    PubMed

    Chapman, Gretchen B; Colby, Helen; Convery, Kimberly; Coups, Elliot J

    2016-05-01

    The effectiveness of a pedometer intervention was affected by manipulating the goals given to participants and by providing social comparison feedback about how participants' performance compared with others. In study 1 (n= 148), university staff members received a low, medium, or high walking goal (10%, 50%, or 100% increase over baseline walking). Participants walked 1358 more steps per day (95% confidence interval [CI], 729, 1985), when receiving a high goal than when receiving a medium goal, but a medium goal did not increase walking relative to a low goal (554 more steps; 95% CI, -71,1179). In study 2 (n= 64), participants received individual feedback only or individual plus social comparison feedback. Participants walked 1120 more steps per day (95% CI, 538, 1703) when receiving social comparison feedback than when receiving only individual feedback. Goals and the performance of others act as reference points and influence the effect that pedometer feedback has on walking behavior, illustrating the applicability of the principles of behavioral economics and social psychology to the design of health behavior interventions.

  5. Sequence comparisons via algorithmic mutual information

    SciTech Connect

    Milosavijevic, A.

    1994-12-31

    One of the main problems in DNA and protein sequence comparisons is to decide whether observed similarity of two sequences should be explained by their relatedness or by mere presence of some shared internal structure, e.g., shared internal tandem repeats. The standard methods that are based on statistics or classical information theory can be used to discover either internal structure or mutual sequence similarity, but cannot take into account both. Consequently, currently used methods for sequence comparison employ {open_quotes}masking{close_quotes} techniques that simply eliminate sequences that exhibit internal repetitive structure prior to sequence comparisons. The {open_quotes}masking{close_quotes} approach precludes discovery of homologous sequences of moderate or low complexity, which abound at both DNA and protein levels. As a solution to this problem, we propose a general method that is based on algorithmic information theory and minimal length encoding. We show that algorithmic mutual information factors out the sequence similarity that is due to shared internal structure and thus enables discovery of truly related sequences. We extend the recently developed algorithmic significance method to show that significance depends exponentially on algorithmic mutual information.

  6. Flat parlog: a basis for comparison

    SciTech Connect

    Foster, I.; Taylor, S.

    1987-04-01

    Three similar parallel logic programming languages have been proposed; Parlog, Flat Concurrent Prolog, and Guarded Horn Clauses. Quantitative comparison of the languages has not previously been possible since they employ different execution models and implementation techniques. In order to uncover the effects of semantic differences on efficiency, a common basis is required for experimentation. This paper presents a subset of the language Parlog called Flat Parlog which provides a basis for quantitative comparison. The language combines the directional semantics of Parlog with the simple execution model of Flat Concurrent Prolog. A performance comparison between Flat Parlog and Flat Concurrent Prolog based on new implementations of both languages is presented. These new implementations are identical except for optimizations that are possible by virtue of semantic differences. Benchmark results indicate that Flat Parlog is more efficient; experiments have been able to quantify and explain this performance differential. A detailed description of the abstract machine for Flat Parlog is presented to illustrate the simplicity of the language.

  7. On the role of code comparisons in verification and validation.

    SciTech Connect

    Oberkampf, William Louis; Trucano, Timothy Guy; Pilch, Martin M.

    2003-08-01

    This report presents a perspective on the role of code comparison activities in verification and validation. We formally define the act of code comparison as the Code Comparison Principle (CCP) and investigate its application in both verification and validation. One of our primary conclusions is that the use of code comparisons for validation is improper and dangerous. We also conclude that while code comparisons may be argued to provide a beneficial component in code verification activities, there are higher quality code verification tasks that should take precedence. Finally, we provide a process for application of the CCP that we believe is minimal for achieving benefit in verification processes.

  8. Physical appearance comparisons in ethnically diverse college women.

    PubMed

    Schaefer, Lauren M; Thibodaux, Lia K; Krenik, Daniel; Arnold, Elysse; Thompson, J Kevin

    2015-09-01

    Research demonstrates ethnic differences in rates of body dissatisfaction and disordered eating. Appearance comparison frequency is related to these outcomes, however, research has not examined possible ethnic differences in levels of appearance comparisons nor their relation to body dissatisfaction and disordered eating. The current study examined the frequency of appearance comparisons and the strength of the relationships between appearance comparisons, appearance evaluation, and disordered eating among White, Black, and Hispanic women. Measures of appearance comparison, appearance evaluation, and disordered eating were administered to 895 college women. Compared with White and Hispanic women, Black women reported fewer appearance comparisons, more positive appearance evaluation, and lower levels of disordered eating. Associations between examined variables were generally weaker among Black women. Results suggest that the reduced frequency and impact of appearance comparisons may contribute to more positive appearance evaluation and reduced levels of disordered eating among Black women.

  9. Appearance comparisons styles and eating disordered symptoms in women.

    PubMed

    Lin, Linda; Soby, Meghann

    2016-12-01

    The purpose of this study was to examine the relationship between styles of upward and downward appearance comparisons and eating disordered symptoms in women. Data on upward and downward appearance comparisons, body dissatisfaction, drive for thinness, dietary restraint, and negative body talk were collected from 321 female college students. Results indicated that upward appearance comparisons were linked to higher levels of drive for thinness, body dissatisfaction, dietary restraint, and negative body talk, whereas downward appearance comparisons were linked to higher levels of drive for thinness and dietary restraint, but showed no relationship to body dissatisfaction and negative body talk. There was an interaction effect between upward and downward comparisons and body image variables. Taken together, this study suggests that downward appearance comparison does not buffer the negative effects of upward appearance comparison, and in some cases can increase negative body image outcomes.

  10. KEY COMPARISON: Report on acceleration comparison SIM.AUV.V-K1

    NASA Astrophysics Data System (ADS)

    Evans, David J.; Hornikova, Adriana; Leigh, Stefan D.; Rukhin, Andrew L.; Strawderman, William

    2009-01-01

    The first regional key comparison in vibration conducted under the auspices of the Inter American System of Metrology (SIM) was begun in 1996. The comparison was registered with the International Bureau of Weights and Measures (BIPM) through the Consultative Committee for Acoustics, Ultrasound and Vibration (CCAUV) under the key comparison designation of SIM.AUV.V K1. The national measurement institutes (NMIs) of five countries participating in SIM performed and reported calibrations of one back-to-back and two single-ended accelerometers for this comparison during the time period of 1997 to 1999. The participants in the comparison were: Argentina (INTI), Brazil (INMETRO), Canada (NRC), Mexico (CENAM) and the United States (NIST). Reference Values (RVs) were established for the SIM.AUV.V-K1 comparison using maximum likelihood consensus estimation applied to the summary values of charge sensitivity with the nominal numbers of repeat measurements reported by the participating NMIs. Degrees of equivalence between the results reported by the NMIs and the RVs as well as pairwise degrees of equivalence between the results reported by the NMIs were computed using the uncertainties associated with the results reported by the NMIs and those of the RVs as appropriate. Transformation values were found in order to link the results of SIM.AUV.V-K1 with those of the first international key comparison in vibration conducted under the auspices of the CCAUV during 1999 to 2001 (CCAUV.V-K1). The degrees of equivalence between the NMIs participating in SIM.AUV.V-K1 and those participating in CCAUV.V-K1 were established using linkage values computed from the transformation values. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual

  11. A mathematical framework for protein structure comparison.

    PubMed

    Liu, Wei; Srivastava, Anuj; Zhang, Jinfeng

    2011-02-03

    Comparison of protein structures is important for revealing the evolutionary relationship among proteins, predicting protein functions and predicting protein structures. Many methods have been developed in the past to align two or multiple protein structures. Despite the importance of this problem, rigorous mathematical or statistical frameworks have seldom been pursued for general protein structure comparison. One notable issue in this field is that with many different distances used to measure the similarity between protein structures, none of them are proper distances when protein structures of different sequences are compared. Statistical approaches based on those non-proper distances or similarity scores as random variables are thus not mathematically rigorous. In this work, we develop a mathematical framework for protein structure comparison by treating protein structures as three-dimensional curves. Using an elastic Riemannian metric on spaces of curves, geodesic distance, a proper distance on spaces of curves, can be computed for any two protein structures. In this framework, protein structures can be treated as random variables on the shape manifold, and means and covariance can be computed for populations of protein structures. Furthermore, these moments can be used to build Gaussian-type probability distributions of protein structures for use in hypothesis testing. The covariance of a population of protein structures can reveal the population-specific variations and be helpful in improving structure classification. With curves representing protein structures, the matching is performed using elastic shape analysis of curves, which can effectively model conformational changes and insertions/deletions. We show that our method performs comparably with commonly used methods in protein structure classification on a large manually annotated data set.

  12. Comparison of Ridges on Triton and Europa

    NASA Technical Reports Server (NTRS)

    Prockter, L. M.; Pappalardo, R. .

    2003-01-01

    Triton and Europa each display a variety of ridges and associated troughs. The resemblance of double ridges on these two satellites has been previously noted [R. Kirk, pers. comm.], but as yet, the similarities and differences between these feature types have not been examined in any detail. Triton s ridges, and Europa s, exhibit an evolutionary sequence ranging from isolated troughs, through doublet ridges, to complex ridge swaths [1, 2]. Comparison of ridges on Europa to those on Triton may provide insight into their formation on both satellites, and thereby have implications for the satellites' histories.

  13. A comparison of RISKIND and RADTRAN 4

    SciTech Connect

    Brumburgh, G.P.; Alesso, H.P.

    1993-11-01

    Our objective in this paper is to provide preliminary comparisons between the two computer codes RISKIND and RADTRAN 4. These codes have utility in evaluating radiological consequences during the transportation of radioactive materials. We reviewed the codes to three criteria: (1) the code`s evaluation capability for accident sequences, frequencies, and environmental consequences, (2) the code`s ``user friendliness`` (as well as how much specific technical expertise the user needed to apply to it), and (3) compatibility with other code output or modules.

  14. Local and Global Comparison of Continuous Functions

    SciTech Connect

    Edelsbrunner, H; Harer, J; Natarajan, V; Pascucci, V

    2004-12-16

    We introduce local and global comparison measures for a collection of k {<=} d real-valued smooth functions on a common d-dimensional Riemannian manifold. For k = d = 2 we relate the measures to the set of critical points of one function restricted to the level sets of the other. The definition of the measures extends to piecewise linear functions for which they are easy to compute. The computation of the measures forms the centerpiece of a software tool which we use to study scientific datasets.

  15. A comparison of tests for thyroglobulin antibody

    PubMed Central

    Rawstron, J. R.; Farthing, C. P.

    1962-01-01

    A comparison is made of tests for thyroglobulin antibody, using gel diffusion, electroprecipitin, bentonite flocculation, tanned red cell agglutination, and latex slide agglutination techniques on sera from cases of Hashimoto's disease and other thyroid disorders. Any increase in γ globulin was also noted from the serum electrophoretic pattern. The gel diffusion and electroprecipitin tests are shown to be comparable in their sensitivity, as are the bentonite flocculation and tanned red cell agglutination tests. The flocculation and agglutination tests were oversensitive. The latex slide test in conjunction with the electro-precipitin test is recommended for routine use in the detection of Hashimoto's disease. Images PMID:14490690

  16. Interior structure of neptune: comparison with uranus.

    PubMed

    Hubbard, W B; Nellis, W J; Mitchell, A C; Holmes, N C; Limaye, S S; McCandless, P C

    1991-08-09

    Measurements of rotation rates and gravitational harmonics of Neptune made with the Voyager 2 spacecraft allow tighter constraints on models of the planet's interior. Shock measurements of material that may match the composition of Neptune, the so-calied planetary ;;ice,'' have been carried out to pressures exceeding 200 gigapascals (2 megabars). Comparison of shock data with inferred pressure-density profiles for both Uranus and Neptune shows substantial similarity through most of the mass of both planets. Analysis of the effect of Neptune's strong differential rotation on its gravitational harmonics indicates that differential rotation involves only the outermost few percent of Neptune's mass.

  17. Interior structure of Neptune: Comparison with Uranus

    SciTech Connect

    Hubbard, W.B. ); Nellis, W.J.; Mitchell, A.C.; Holmes, N.C.; McCandless, P.C. ); Limaye, S.S. )

    1991-08-09

    Measurements of rotation rates and gravitational harmonics of Neptune made with the Voyager 2 spacecraft allow tighter constraints on models of the planet's interior. Shock measurements of material that may match the composition of Neptune, the so-called planetary ice, have been carried out to pressures exceeding 200 gigapascals (2 megabars). Comparison of shock data with inferred pressure-density profiles for both Uranus and Neptune shows substantial similarity through most of the mass of both planets. Analysis of the effect of Neptune's strong differential rotation on its gravitational harmonics indicates that differential rotation involves only the outermost few percent of Neptune's mass.

  18. Planetary size comparisons: A photographic study

    NASA Technical Reports Server (NTRS)

    Meszaros, S. P.

    1983-01-01

    Over the past two decades NASA spacecraft missions obtained photographs permitting accurate size measurements of the planets and moons, and their surface features. Planetary global views are displayed at the same scale, in each picture to allow visual size comparisons. Additionally, special geographical features on some of the planets are compared with selected Earth areas, again at the same scale. Artist renderings and estimated sizes are used for worlds not yet reached by spacecraft. Included with each picture is number designation for use in ordering copies of the photos.

  19. Multivariate Lipschitz optimization: Survey and computational comparison

    SciTech Connect

    Hansen, P.; Gourdin, E.; Jaumard, B.

    1994-12-31

    Many methods have been proposed to minimize a multivariate Lipschitz function on a box. They pertain the three approaches: (i) reduction to the univariate case by projection (Pijavskii) or by using a space-filling curve (Strongin); (ii) construction and refinement of a single upper bounding function (Pijavskii, Mladineo, Mayne and Polak, Jaumard Hermann and Ribault, Wood...); (iii) branch and bound with local upper bounding functions (Galperin, Pint{acute e}r, Meewella and Mayne, the present authors). A survey is made, stressing similarities of algorithms, expressed when possible within a unified framework. Moreover, an extensive computational comparison is reported on.

  20. Rooftop Unit Comparison Calculator User Manual

    SciTech Connect

    Miller, James D.

    2015-04-30

    This document serves as a user manual for the Packaged rooftop air conditioners and heat pump units comparison calculator (RTUCC) and is an aggregation of the calculator’s website documentation. Content ranges from new-user guide material like the “Quick Start” to the more technical/algorithmic descriptions of the “Methods Pages.” There is also a section listing all the context-help topics that support the features on the “Controls” page. The appendix has a discussion of the EnergyPlus runs that supported the development of the building-response models.

  1. Numerical comparison between DHF and RHF methods

    NASA Astrophysics Data System (ADS)

    Kobus, J.; Jaskolski, W.

    1987-10-01

    A detailed numerical comparison of the Dirac-Hartree-Fock method and the relativistic Hartree-Fock (RHF) method of Cowan and Griffith (1976) is presented, considering the total energy, the orbital energies, and the one-electron and two-electron integrals. The RHF method is found to yield accurate values of the relativistic transition energies. Using accurate values of the correlation corrections for p-electron and d-electron systems, the usefulness of the RHF method in obtaining relativistic corrections to the differential term energies is demonstrated. Advantages of the method for positron scattering on heavy systems are also pointed out.

  2. A comparison of thermal zone aggregation methods

    SciTech Connect

    Dobbs, Justin R.; Hencey, Brandon M.

    2012-12-10

    The impact of increasing energy prices on building operation budgets has fueled demand for more energy-efficient structures. Existing building energy simulation tools generate an immense amount of data yet comparatively little knowledge. This paper introduces a framework that allows aggregation-based model reduction to operate on geometric building information models. The resulting aggregation sequence provides designers with faster simulations and affords insight into complex multi-scale thermal interactions. A comparison of the trade-off between simulation speed and accuracy for three hierarchical cluster partitioning methods concludes the discussion.

  3. Comparison of erosion and channel characteristics

    USGS Publications Warehouse

    Parker, Gene W.

    1998-01-01

    Erosion was observed at 33 percent of 22,495 bridge sites in nine States. Among sites with erosion, 56 percent were associated with skewed flows, curved channels, or a combination of these two conditions, and at 18 percent of the sites, channels were straight with steep bank angles. The remaining 26 percent are sites with observable erosion at piers or abutments on straight channels. Comparison of the sites with erosion to channel bed-material indicate that 44 percent of the single-span sites had gravel-size or smaller bed material and 70 percent of the multiple-span sites had gravel-size or smaller bed material.

  4. Quantum Private Comparison Protocol with Linear Optics

    NASA Astrophysics Data System (ADS)

    Luo, Qing-bin; Yang, Guo-wu; She, Kun; Li, Xiaoyu

    2016-12-01

    In this paper, we propose an innovative quantum private comparison(QPC) protocol based on partial Bell-state measurement from the view of linear optics, which enabling two parties to compare the equality of their private information with the help of a semi-honest third party. Partial Bell-state measurement has been realized by using only linear optical elements in experimental measurement-device-independent quantum key distribution(MDI-QKD) schemes, which makes us believe that our protocol can be realized in the near future. The security analysis shows that the participants will not leak their private information.

  5. Neuropsychological comparison of children with heavy prenatal alcohol exposure and an IQ-matched comparison group.

    PubMed

    Vaurio, Linnea; Riley, Edward P; Mattson, Sarah N

    2011-05-01

    An objective in current research on children with fetal alcohol spectrum disorders (FASD) is to determine neurobehavioral profiles to identify affected individuals. Deficits observed when children with FASD are compared to typically developing controls may be confounded by lower IQ scores in the subjects with FASD. To determine if prenatal alcohol exposure is associated with neurobehavioral deficits after controlling for IQ differences, multivariate analyses were conducted to compare alcohol-exposed (ALC) subjects to a comparison group closely matched on IQ (IQC). The initial analysis included a broad neuropsychological battery with measures of language, executive function, visual-motor integration, motor ability, and academic achievement. Additional, in depth comparisons focused on visual sustained attention, verbal learning and memory and parent/guardian-reported behavior problems. Group differences (ALC < IQC) were found on verbal learning and parent-rated behavior problems. Group differences were marginally significant (measures within the broad neuropsychological comparison) or not significant (visual attention, retention of verbal material) on the remaining comparisons. Therefore, some deficits (e.g., verbal learning and behavior problems) in children with heavy prenatal alcohol exposure cannot be explained by the lower FSIQ observed in the population. These areas of relative weakness could be useful in distinguishing children with FASD from other children with lowered IQ.

  6. Comparison of State Unemployment Insurance Laws. Comparison Revision, Number 1, August 6, 1978.

    ERIC Educational Resources Information Center

    Employment and Training Administration (DOL), Washington, DC. Unemployment Insurance Service.

    To inform the public about details of the employment security program and how it functions, this comparison of state unemployment insurance laws is presented. The report is based primarily on an analysis of state statutes. It examines state by state the types of workers and employers that are covered under the state law, the methods of financing…

  7. Effects of Comparison Question Type and Between Test Stimulation on the Validity of Comparison Question Test

    DTIC Science & Technology

    2009-09-08

    C. J., & Iacono, W. G. (1989). Psychopathy , threat, and polygraph test accuracy. Journal of Applied Psychology, 74, 347-355. Patrick, C. J... Psychopathy and detection of deception in a prison population. Psychophysiology, 15,121-136. Raskin, D. C, & Honts, C. R. (2002). The comparison question

  8. Alternate Propulsion Subsystem Concepts Tripropellant Comparison Study

    NASA Technical Reports Server (NTRS)

    Levack, Daniel

    1995-01-01

    A study was conducted under MSFC contract NAS8-39210 to compare tripropellant and bipropellant engine configurations for the SSTO mission. The objective was to produce an 'apples-to-apples' comparison to isolate the effects of design implementation, designing company, year of design, or technologies included from the basic tripropellant/bipropellant comparison. Consequently, identical technologies were included (e.g., jet pumps) and the same design groundrules and practices were used. Engine power cycles were examined as were turbomachinery/preburner arrangements for each cycle. The bipropellant approach and two tripropellant approaches were separately optimized in terms of operating parameters: exit pressures, mixture ratios, thrust splits, etc. This briefing presents the results of the study including engine weights for both tripropellant and bipropellant engines; dry vehicle weight performance for a range of engine chamber pressures; discusses the basis for the results; examines vehicle performance due to engine cycles and the margin characteristics of various cycles; and identifies technologies with significant payoffs for this application.

  9. Comparisons of Yield Calculations with Data

    SciTech Connect

    Dugan, G.

    1986-02-01

    Given what is claimed to a reasonably accurate technique for calculating the pbar yield, it is useful to ask for comparisons with the data available from the recent commissioning run. The simplest comparison to make is that of the yield. The number of pbars circulating in the Debuncher was measured many times; the total number of secondaries at IC728 in AP-2 was also measured many times. The ratio of pbars to total flux at IC728 was measured once (Bk. I, p 166); this number was {bar P}/total = 0.032. Typically, the ratio of secondaries at IC728 to protons on target was about 0.0012 (this was about the same number, independent of whether the lens was operated at 600 or 1000 T/m.). Thus, at IC728 we have N{sub P}/N{sub {bar P}} {approx} 1.2 x 10{sup -3} x 3.2 x 10{sup -2} = 3.8 x 10{sup -5} = 38 ppm.

  10. Water gun vs air gun: A comparison

    USGS Publications Warehouse

    Hutchinson, D.R.; Detrick, R. S.

    1984-01-01

    The water gun is a relatively new marine seismic sound source that produces an acoustic signal by an implosive rather than explosive mechanism. A comparison of the source characteristics of two different-sized water guns with those of conventional air guns shows the the water gun signature is cleaner and much shorter than that of a comparable-sized air gun: about 60-100 milliseconds (ms) for an 80-in3. (1.31-liter (I)) water gun compared with several hundred ms for an 80-in3. (1.31-1) air gun. The source spectra of water guns are richer in high frequencies (>200 Hz) than are those of air guns, but they also have less energy than those of air guns at low frequencies. A comparison between water gun and air gun reflection profiles in both shallow (Long Island Sound)-and deep (western Bermuda Rise)-water settings suggests that the water gun offers a good compromise between very high resolution, limited penetration systems (e.g. 3.5-kHz profilers and sparkers) and the large volume air guns and tuned air gun arrays generally used where significant penetration is required. ?? 1984 D. Reidel Publishing Company.

  11. Solar Sail GN and C Model Comparisons

    NASA Technical Reports Server (NTRS)

    Heaton, Andrew F.

    2004-01-01

    The Solar Sail Propulsion project is engaged in an ambitious program to raise the Technology Readiness Level of solar sails and prepare for a validation flight via a series of hardware ground demonstrations and development of a number of high fidelity simulations and models. Guidance, navigation, and control of solar sails is a key part of this effort. The large flexible structure and optical nature of solar sails create a considerable challenge for attitude control, thrust modeling, and navigation. In this paper, we present an overview and comparison of two recently delivered prototype solar sail guidance, navigation, and control software tools currently funded by the Solar Sail Propulsion project. The results of some key test cases are presented. Where possible, we also make comparisons to other software tools. We discuss the implications of the results of these comparative studies to the future direction and scope of development efforts for guidance, navigation and control software for solar sails, including the relationship to hardware test efforts such as the Thrust Vector Control Authority Demonstration.

  12. Comparison of radar data versus rainfall data.

    PubMed

    Espinosa, B; Hromadka, T V; Perez, R

    2015-01-01

    Doppler radar data are increasingly used in rainfall-runoff synthesis studies, perhaps due to radar data availability, among other factors. However, the veracity of the radar data are often a topic of concern. In this paper, three Doppler radar outcomes developed by the United States National Weather Service at three radar sites are examined and compared to actual rain gage data for two separate severe storm events in order to assess accuracy in the published radar estimates of rainfall. Because the subject storms were very intense rainfall events lasting approximately one hour in duration, direct comparisons between the three radar gages themselves can be made, as well as a comparison to rain gage data at a rain gage location subjected to the same storm cells. It is shown that topographic interference with the radar outcomes can be a significant factor leading to differences between radar and rain gage readings, and that care is needed in calibrating radar outcomes using available rain gage data in order to interpolate rainfall estimates between rain gages using the spatial variation observed in the radar readings. The paper establishes and describes•the need for "ground-truthing" of radar data, and•possible errors due to topographic interference.

  13. Comparison of Fast Neutron Detector Technologies

    SciTech Connect

    Stange, Sy; Mckigney, Edward Allen

    2015-02-09

    This report documents the work performed for the Department of Homeland Security Domestic Nuclear Detection O ce as the project Fast Neutron Detection Evaluation under contract HSHQDC-14-X-00022. This study was performed as a follow-on to the project Study of Fast Neutron Signatures and Measurement Techniques for SNM Detection - DNDO CFP11-100 STA-01. That work compared various detector technologies in a portal monitor con guration, focusing on a comparison between a number of fast neutron detection techniques and two standard thermal neutron detection technologies. The conclusions of the earlier work are contained in the report Comparison of Fast Neutron Detector Technologies. This work is designed to address questions raised about assumptions underlying the models built for the earlier project. To that end, liquid scintillators of two di erent sizes{ one a commercial, o -the-shelf (COTS) model of standard dimensions and the other a large, planer module{were characterized at Los Alamos National Laboratory. The results of those measurements were combined with the results of the earlier models to gain a more complete picture of the performance of liquid scintillator as a portal monitor technology.

  14. Data for Room Fire Model Comparisons

    PubMed Central

    Peacock, Richard D.; Davis, Sanford; Babrauskas, Vytenis

    1991-01-01

    With the development of models to predict fire growth and spread in buildings, there has been a concomitant evolution in the measurement and analysis of experimental data in real-scale fires. This report presents the types of analyses that can be used to examine large-scale room fire test data to prepare the data for comparison with zone-based fire models. Five sets of experimental data which can be used to test the limits of a typical two-zone fire model are detailed. A standard set of nomenclature describing the geometry of the building and the quantities measured in each experiment is presented. Availability of ancillary data (such as smaller-scale test results) is included. These descriptions, along with the data (available in computer-readable form) should allow comparisons between the experiment and model predictions. The base of experimental data ranges in complexity from one room tests with individual furniture items to a series of tests conducted in a multiple story hotel equipped with a zoned smoke control system. PMID:28184121

  15. Multiple comparison analysis testing in ANOVA.

    PubMed

    McHugh, Mary L

    2011-01-01

    The Analysis of Variance (ANOVA) test has long been an important tool for researchers conducting studies on multiple experimental groups and one or more control groups. However, ANOVA cannot provide detailed information on differences among the various study groups, or on complex combinations of study groups. To fully understand group differences in an ANOVA, researchers must conduct tests of the differences between particular pairs of experimental and control groups. Tests conducted on subsets of data tested previously in another analysis are called post hoc tests. A class of post hoc tests that provide this type of detailed information for ANOVA results are called "multiple comparison analysis" tests. The most commonly used multiple comparison analysis statistics include the following tests: Tukey, Newman-Keuls, Scheffee, Bonferroni and Dunnett. These statistical tools each have specific uses, advantages and disadvantages. Some are best used for testing theory while others are useful in generating new theory. Selection of the appropriate post hoc test will provide researchers with the most detailed information while limiting Type 1 errors due to alpha inflation.

  16. Storage as a Metric of Catchment Comparison

    USGS Publications Warehouse

    McNamara, J.P.; Tetzlaff, D.; Bishop, K.; Soulsby, C.; Seyfried, M.; Peters, N.E.; Aulenbach, Brent T.; Hooper, R.

    2011-01-01

    The volume of water stored within a catchment, and its partitioning among groundwater, soil moisture, snowpack, vegetation, and surface water are the variables that ultimately characterize the state of the hydrologic system. Accordingly, storage may provide useful metrics for catchment comparison. Unfortunately, measuring and predicting the amount of water present in a catchment is seldom done; tracking the dynamics of these stores is even rarer. Storage moderates fluxes and exerts critical controls on a wide range of hydrologic and biologic functions of a catchment. While understanding runoff generation and other processes by which catchments release water will always be central to hydrologic science, it is equally essential to understand how catchments retain water. We have initiated a catchment comparison exercise to begin assessing the value of viewing catchments from the storage perspective. The exercise is based on existing data from five watersheds, no common experimental design, and no integrated modelling efforts. Rather, storage was estimated independently for each site. This briefing presents some initial results of the exercise, poses questions about the definitions and importance of storage and the storage perspective, and suggests future directions for ongoing activities. ?? 2011 John Wiley & Sons, Ltd.

  17. Quantum Private Comparison via Cavity QED

    NASA Astrophysics Data System (ADS)

    Ye, Tian-Yu

    2017-02-01

    The first quantum private comparison (QPC) protocol via cavity quantum electrodynamics (QED) is proposed in this paper by making full use of the evolution law of atom via cavity QED, where the third party (TP) is allowed to misbehave on his own but cannot conspire with either of the two users. The proposed protocol adopts two-atom product states rather than entangled states as the initial quantum resource, and only needs single-atom measurements for two users. Both the unitary operations and the quantum entanglement swapping operation are not necessary for the proposed protocol. The proposed protocol can compare the equality of one bit from each user in each round comparison with one two-atom product state. The proposed protocol can resist both the outside attack and the participant attack. Particularly, it can prevent TP from knowing two users’ secrets. Furthermore, the qubit efficiency of the proposed protocol is as high as 50%. Supported by the National Natural Science Foundation of China under Grant No. 61402407

  18. Thermal sensation models: a systematic comparison.

    PubMed

    Koelblen, B; Psikuta, A; Bogdan, A; Annaheim, S; Rossi, R M

    2016-08-26

    Thermal sensation models, capable of predicting human's perception of thermal surroundings, are commonly used to assess given indoor conditions. These models differ in many aspects, such as the number and type of input conditions, the range of conditions in which the models can be applied, and the complexity of equations. Moreover, the models are associated with various thermal sensation scales. In this study, a systematic comparison of seven existing thermal sensation models has been performed with regard to exposures including various air temperatures, clothing thermal insulation, and metabolic rate values after a careful investigation of the models' range of applicability. Thermo-physiological data needed as input for some of the models were obtained from a mathematical model for human physiological responses. The comparison showed differences between models' predictions for the analyzed conditions, mostly higher than typical intersubject differences in votes. Therefore, it can be concluded that the choice of model strongly influences the assessment of indoor spaces. The issue of comparing different thermal sensation scales has also been discussed.

  19. Methods for peptide identification by spectral comparison

    PubMed Central

    Liu, Jian; Bell, Alexander W; Bergeron, John JM; Yanofsky, Corey M; Carrillo, Brian; Beaudrie, Christian EH; Kearney, Robert E

    2007-01-01

    Background Tandem mass spectrometry followed by database search is currently the predominant technology for peptide sequencing in shotgun proteomics experiments. Most methods compare experimentally observed spectra to the theoretical spectra predicted from the sequences in protein databases. There is a growing interest, however, in comparing unknown experimental spectra to a library of previously identified spectra. This approach has the advantage of taking into account instrument-dependent factors and peptide-specific differences in fragmentation probabilities. It is also computationally more efficient for high-throughput proteomics studies. Results This paper investigates computational issues related to this spectral comparison approach. Different methods have been empirically evaluated over several large sets of spectra. First, we illustrate that the peak intensities follow a Poisson distribution. This implies that applying a square root transform will optimally stabilize the peak intensity variance. Our results show that the square root did indeed outperform other transforms, resulting in improved accuracy of spectral matching. Second, different measures of spectral similarity were compared, and the results illustrated that the correlation coefficient was most robust. Finally, we examine how to assemble multiple spectra associated with the same peptide to generate a synthetic reference spectrum. Ensemble averaging is shown to provide the best combination of accuracy and efficiency. Conclusion Our results demonstrate that when combined, these methods can boost the sensitivity and specificity of spectral comparison. Therefore they are capable of enhancing and complementing existing tools for consistent and accurate peptide identification. PMID:17227583

  20. Bilateral Comparison in Chemosensory-Mediated Foraging

    NASA Astrophysics Data System (ADS)

    Webster, D. R.; Rahman, S.; Dasi, L. P.

    2000-11-01

    Motivation is drawn from the need to determine the sensory cues that animals such as blue crabs and lobsters use to track chemical odor plumes to locate food or mates. Major steps forward with this difficult problem can only be achieved through an appreciation of the spatial and temporal variation of concentration fields and the information content available to a forager in the plume. Here we discuss the usefulness of bilateral comparison to an animal tracking a turbulent plume. Instantaneous concentration fields of a chemical plume diffusing in a fully-developed turbulent open channel flow are measured using planar laser-induced fluorescence (PLIF). The plume is released iso-kinetically 25 mm above the smooth bed (z+ = 90), thus transport is mainly due to advection and ambient turbulence. A spatial correlation function in the spanwise direction is a dramatic indicator of the relative position of the centerline and distance from the source. The relative direction of the plume centerline can be estimated from an instantaneous bilateral comparison provided the sensors are separated by a distance that is relatively large compared to the spanwise integral length scale based on the spatial correlation function.

  1. Cirrus Parcel Model Comparison Project. Phase 1

    NASA Technical Reports Server (NTRS)

    Lin, Ruei-Fong; Starr, David O'C.; DeMott, Paul J.; Cotton, Richard; Jensen, Eric; Sassen, Kenneth

    2000-01-01

    The Cirrus Parcel Model Comparison (CPMC) is a project of the GEWEX Cloud System Study Working Group on Cirrus Cloud Systems (GCSS WG2). The primary goal of this project is to identify cirrus model sensitivities to the state of our knowledge of nucleation and microphysics. Furthermore, the common ground of the findings may provide guidelines for models with simpler cirrus microphysics modules. We focus on the nucleation regimes of the warm (parcel starting at -40 C and 340 hPa) and cold (-60 C and 170 hPa) cases studied in the GCSS WG2 Idealized Cirrus Model Comparison Project. Nucleation and ice crystal growth were forced through an externally imposed rate of lift and consequent adiabatic cooling. The background haze particles are assumed to be lognormally-distributed H2SO4 particles. Only the homogeneous nucleation mode is allowed to form ice crystals in the HN-ONLY runs; all nucleation modes are switched on in the ALL-MODE runs. Participants were asked to run the HN-lambda-fixed runs by setting lambda = 2 (lambda is further discussed in section 2) or tailoring the nucleation rate calculation in agreement with lambda = 2 (exp 1). The depth of parcel lift (800 m) was set to assure that parcels underwent complete transition through the nucleation regime to a stage of approximate equilibrium between ice mass growth and vapor supplied by the specified updrafts.

  2. Factorial Comparison of Working Memory Models

    PubMed Central

    van den Berg, Ronald; Awh, Edward; Ma, Wei Ji

    2014-01-01

    Three questions have been prominent in the study of visual working memory limitations: (a) What is the nature of mnemonic precision (e.g., quantized or continuous)? (b) How many items are remembered? (c) To what extent do spatial binding errors account for working memory failures? Modeling studies have typically focused on comparing possible answers to a single one of these questions, even though the result of such a comparison might depend on the assumed answers to both others. Here, we consider every possible combination of previously proposed answers to the individual questions. Each model is then a point in a 3-factor model space containing a total of 32 models, of which only 6 have been tested previously. We compare all models on data from 10 delayed-estimation experiments from 6 laboratories (for a total of 164 subjects and 131,452 trials). Consistently across experiments, we find that (a) mnemonic precision is not quantized but continuous and not equal but variable across items and trials; (b) the number of remembered items is likely to be variable across trials, with a mean of 6.4 in the best model (median across subjects); (c) spatial binding errors occur but explain only a small fraction of responses (16.5% at set size 8 in the best model). We find strong evidence against all 6 documented models. Our results demonstrate the value of factorial model comparison in working memory. PMID:24490791

  3. SUPPLEMENTARY COMPARISON: Final report on Supplementary Comparison APMP.M.H-S1

    NASA Astrophysics Data System (ADS)

    Kongkavitool, Rugkanawan; Hattori, Koichiro; Sanh, Vo; Yen, Lim Gin

    2007-01-01

    This report presents the results of supplementary comparison APMP.M.H-S1 among four national metrology institutes (NIMT, NMIJ/AIST, VMI and SPRING). The comparison was carried out during October 2004 to January 2005 in order to determine the capability of the primary Rockwell hardness standard, including standard conditions, of each participant, to confirm the accuracy of Rockwell hardness scale C measurement declared by the participant, which includes the effect of each participant's primary indenter and determine the degrees of equivalence of hardness scale measurement in the range 20 HRC to 60 HRC. Furthermore, the comparison was carried out a by common indenter, which was provided by the pilot institute, in order to determine the measurement capability of the participant's primary machine without the influence of the indenter, as a study of scientific purpose. The pilot institute was the National Institute of Metrology (Thailand), NIMT. There were two sets of artifacts for the comparison. Each set was composed of nine hardness blocks: 20 HRC, 25 HRC, 30 HRC, 35 HRC, 40 HRC, 45 HRC, 50 HRC, 55 HRC, 60 HRC. The verification of the participant's primary Rockwell hardness machine was carried out according to ISO6508-3 before making the measurement. The pilot institute made measurements at the beginning and the end of the comparison in order to monitor the stability of the artifacts. The degree of equivalence of each national primary hardness standard was expressed quantitatively by two terms, the deviation from KCRV and the uncertainty of this deviation at a 95% level of confidence. The En parameter was calculated to express the equivalence between the measurements of participants as well. The degree of equivalence between pairs of participating institutes was expressed by the difference of their deviations from the key comparison reference value and the uncertainty of this difference at the 95% level of confidence. Main text. To reach the main text of this paper

  4. Final report on CCM key comparison CCM.D-K2: Comparison of liquid density standards

    NASA Astrophysics Data System (ADS)

    Bettin, Horst; Jacques, Claude; Zelenka, Zoltán; Fujii, Ken-ichi; Kuramoto, Naoki; Chang, Kyung-Ho; Lee, Yong Jae; Becerra, Luis Omar; Domostroeva, Natalia

    2013-01-01

    The results are presented of the key comparison CCM.D-K2 that covered the density measurements of four liquids: the density of water at 20 °C, of pentadecane at 15 °C, 20 °C, 40 °C and 60°C, of tetrachloroethlyene at 5 °C and 20 °C and of a viscous oil at 20 °C. Seven national metrology institutes measured the densities at atmospheric pressure by hydrostatic weighing of solid density standards in the time interval from 27 April 2004 to 28 June 2004. Since the participants were asked not to include components for a possible drift or inhomogeneity of the liquid in their uncertainty budget, these uncertainty contributions are investigated for the final evaluation of the data. For this purpose, results of stability and homogeneity measurements of the pilot laboratory are used. The participants decided not to include a possible drift of the liquid's density since no significant drift could be detected, and the influence of the drift and its uncertainty are negligible. Similarly, the inhomogeneity of the water and pentadecane samples is not significant and has no influence on the evaluation. Thus, it was neglected. Only the inhomogeneities of tetrachloroethylene and of the viscous oil were significant. Consequently, they were included in the evaluation. With one or two exceptions, the results show good agreement among the participants. Only in the case of water are the results clearly discrepant. The key comparison reference values were calculated by the weighted mean (taking into account a small correlation between two participants) in the case of consistent results. Otherwise the Procedure B of Cox was used. The expanded uncertainties of all reference densities are below 1 × 10-5 in relative terms. This satisfies the needs of all customers who wish to calibrate or check liquid density measuring instruments such as oscillation-type density meters. The comparison fully supports the calibration measurement capabilities table in the BIPM key comparison database

  5. SUPPLEMENTARY COMPARISON: EUROMET.L-S10 Comparison of squareness measurements

    NASA Astrophysics Data System (ADS)

    Mokros, Jiri

    2005-01-01

    The idea of performing a comparison of squareness resulted from the need to review the MRA Appendix C, Category 90° square. At its meeting in October 1999 (in Prague) it was decided upon a first comparison of squareness measurements in the framework of EUROMET, numbered #570, starting in 2000, with the Slovak Institute of Metrology (SMU) as the pilot laboratory. During the preparation stage of the project, it was agreed that it should be submitted as a EUROMET supplementary comparison in the framework of the Mutual Recognition Arrangement (MRA) of the Metre Convention and would boost confidence in calibration and measurement certificates issued by the participating national metrology institutes. The aim of the comparison of squareness measurement was to compare and verify the declared calibration measurement capabilities of participating laboratories and to investigate the effect of systematic influences in the measurement process and their elimination. Eleven NMIs from the EUROMET region carried out this project. Two standards were calibrated: granite squareness standard of rectangular shape, cylindrical squareness standard of steel with marked positions for the profile lines. The following parameters had to be calibrated: granite squareness standard: interior angle γB between two lines AB and AC (envelope - LS regression) fitted through the measured profiles, and/or granite squareness standard: interior angle γLS between two LS regression lines AB and AC fitted through the measured profiles, cylindrical squareness standard: interior angles γ0°, γ90°, γ180°, γ270° between the LS regression line fitted through the measurement profiles at 0°, 90°, 180°, 270° and the envelope plane of the basis (resting on a surface plate), local LS straightness deviation for all measured profiles (2 and 4) of both standards. The results of the comparison are the deviations of profiles and angles measured by the individual NMIs from the reference values. These resulted

  6. Transfer standard uncertainty can cause inconclusive inter-laboratory comparisons

    NASA Astrophysics Data System (ADS)

    Wright, John; Toman, Blaza; Mickan, Bodo; Wübbeler, Gerd; Bodnar, Olha; Elster, Clemens

    2016-12-01

    Inter-laboratory comparisons use the best available transfer standards to check the participants’ uncertainty analyses, identify underestimated uncertainty claims or unknown measurement biases, and improve the global measurement system. For some measurands, instability of the transfer standard can lead to an inconclusive comparison result. If the transfer standard uncertainty is large relative to a participating laboratory’s uncertainty, the commonly used standardized degree of equivalence  ⩽1 criterion does not always correctly assess whether a participant is working within their uncertainty claims. We show comparison results that demonstrate this issue and propose several criteria for assessing a comparison result as passing, failing, or inconclusive. We investigate the behavior of the standardized degree of equivalence and alternative comparison measures for a range of values of the transfer standard uncertainty relative to the individual laboratory uncertainty values. The proposed alternative criteria successfully discerned between passing, failing, and inconclusive comparison results for the cases we examined.

  7. How social neuroscience can inform theories of social comparison.

    PubMed

    Swencionis, Jillian K; Fiske, Susan T

    2014-04-01

    Social comparison pervades our interactions with others, informing us of our standing and motivating improvement, but producing negative emotional and behavioral consequences that can harm relationships and lead to poor health outcomes. Social neuroscience research has begun to illuminate some mechanisms by which status divides lead to interpersonal consequences. This review integrates core findings on the neuroscience of social comparison processes, showing the effects of comparing the self to relevant others on dimensions of competence and warmth. The literature converges to suggest that relative status divides initiate social comparison processes, that upward and downward comparisons initiate pain- and pleasure-related neural responses, and that these responses can predict people׳s kindly or aggressive intentions toward one another. Across different types of comparisons, brain regions involved in mentalizing are also sometimes involved. Along with future work, the research reviewed here may inform efforts to mitigate negative outcomes of constant social comparisons.

  8. Transfer Standard Uncertainty Can Cause Inconclusive Inter-Laboratory Comparisons.

    PubMed

    Wright, John; Toman, Blaza; Mickan, Bodo; Wübbeler, Gerd; Bodnar, Olha; Elster, Clemens

    2016-12-01

    Inter-laboratory comparisons use the best available transfer standards to check the participants' uncertainty analyses, identify underestimated uncertainty claims or unknown measurement biases, and improve the global measurement system. For some measurands, instability of the transfer standard can lead to an inconclusive comparison result. If the transfer standard uncertainty is large relative to a participating laboratory's uncertainty, the commonly used standardized degree of equivalence ≤ 1 criterion does not always correctly assess whether a participant is working within their uncertainty claims. We show comparison results that demonstrate this issue and propose several criteria for assessing a comparison result as passing, failing, or inconclusive. We investigate the behavior of the standardized degree of equivalence and alternative comparison measures for a range of values of the transfer standard uncertainty relative to the individual laboratory uncertainty values. The proposed alternative criteria successfully discerned between passing, failing, and inconclusive comparison results for the cases we examined.

  9. KEY COMPARISON: Key comparison CCQM-K45: Sn in tomato paste: final report

    NASA Astrophysics Data System (ADS)

    Wolff Briche, Céline S. J.; Holcombe, Gill; Sargent, Mike

    2006-01-01

    Key comparison CCQM-K45 was performed to demonstrate and document the capability of interested national metrology institutes in the mass fraction of Sn in a food matrix. This comparison was an activity of the Inorganic Analysis Working Group of the Comité Consultatif pour la Qualité de la Matière and was coordinated by LGC (Teddington, UK). The following laboratories participated in this key comparison (alphabetical order). KRISS (Republic of South Korea) LGC (UK) LNE (France) PTB (Germany) UME (Turkey) Good agreement was observed between the reported results of four of the participants. The other participant did not use any HCl during the sample preparation, which can affect the stability of the tin in solution, and its reported value was lower than for the other participants. It was not included in the calculation of the key comparison reference value with the agreement of the NMI concerned. The reference value was calculated as the arithmetic mean of the reported participants' results (excluding one), and is equal to 227.1 mg kg-1, with an expanded uncertainty of 2.4 mg kg-1 (1.1%). The equivalence statements were calculated on this basis. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  10. Development of a Site Comparison Index: Southeast Upland Forests

    DTIC Science & Technology

    2007-05-01

    ER D C/ CE R L TR -0 7 -1 2 Strategic Environmental Research and Development Program Development of a Site Comparison Index : Southeast...Development of a Site Comparison Index : Southeast Upland Forests Anthony J. Krzysik Prescott College 220 Grove Avenue Prescott, AZ 86301 Harold E...jective site comparison index (SCI), a combination of metrics: soil A- horizon depth, soil compaction, ground cover, canopy cover, basal area, remote

  11. Remote and Ground Truth Spectral Measurement Comparisons

    NASA Technical Reports Server (NTRS)

    Abercromby, Kira Jorgensen; Hamada, Kris; Guyote, Michael; Okada, Jennifer; Barker, Edwin

    2007-01-01

    FORMOSAT III are a set of six research satellites from Taiwan that were launched in April 2006. The satellites are in 800 km, 71 degree inclination orbits and separated by 24 degrees in ascending node. Ground truth spectral measurements were taken of outer surface materials on FORMOSAT III. From those measurements, a computer model was built to predict the spectral reflectance, which included phase angle and orientation of the spacecraft relative to the observer. However, materials exposed to the space environment have exhibited spectral changes including a darkening and a reddening of the spectra. This reddening was seen as an increase in slope of the reflectance as the wavelength increases. Therefore, the model of pristine materials was augmented to include the space weathering effects. Remote data were collected on two of the six FORMOSAT satellites using the 1.6 meter telescope at AMOS (Air Force Maui Optical and Supercomputing) site with the Spica spectrometer. Due to the separation in ascending node, observations were made on whichever one of the six satellites was visible on that specific night. Three nights of data were collected using the red (6000 9500 angstroms) filter and two nights of data were collected using the blue (3200 -6600 angstroms) filter. A comparison of the data showed a good match to the pristine model for the blue filter region. The absorption feature near 5500 angstroms due to the copper colored Kapton multi-layer insulation (MLI) was very apparent in the remote samples and a good fit to the data was seen in both satellites observed. The features in the red filter regime agreed with the pristine model up through 7000 angstroms where the reddening begins and the slope of the remote sample increases. A comparison of the two satellites showed similar features in the red and blue filter regions, i.e. the satellites were aging at the same rate. A comparison of the pristine model to the first month of remote measurements showed the amount by

  12. A comparison of histomorphometric data collection methods.

    PubMed

    Stewart, Marissa C; McCormick, Lara E; Goliath, Jesse R; Sciulli, Paul W; Stout, Sam D

    2013-01-01

    Although many variables that skeletal biologists examine have been standardized, the actual techniques used to collect these data from bone thin sections vary. This project compares different methods of obtaining data (relative cortical area values) for histomorphometric research. One visual and three digital methods of histomorphometric data collection are compared: (i) Merz microscopic eyepiece counting reticule, (ii) flatbed scanner, (iii) overlaying multiple images of a thin section, and (iv) digital SLR camera with macro settings. The discussion includes a comparison of usability factors such as cost, time, user-experience, and ease-of-use, which vary for each method. Values from the different methods are compared using ANOVA tests to evaluate inter-method, inter-observer, and intra-observer variability. Intra-observer error was greater for the microscopic method, although the error values are concomitant with experience. We found no statistically significant differences between the four methods examined, but certain caveats must be addressed when these methods are used.

  13. Insights from Human/Mouse genome comparisons

    SciTech Connect

    Pennacchio, Len A.

    2003-03-30

    Large-scale public genomic sequencing efforts have provided a wealth of vertebrate sequence data poised to provide insights into mammalian biology. These include deep genomic sequence coverage of human, mouse, rat, zebrafish, and two pufferfish (Fugu rubripes and Tetraodon nigroviridis) (Aparicio et al. 2002; Lander et al. 2001; Venter et al. 2001; Waterston et al. 2002). In addition, a high-priority has been placed on determining the genomic sequence of chimpanzee, dog, cow, frog, and chicken (Boguski 2002). While only recently available, whole genome sequence data have provided the unique opportunity to globally compare complete genome contents. Furthermore, the shared evolutionary ancestry of vertebrate species has allowed the development of comparative genomic approaches to identify ancient conserved sequences with functionality. Accordingly, this review focuses on the initial comparison of available mammalian genomes and describes various insights derived from such analysis.

  14. Critical comparison of 3D imaging approaches

    SciTech Connect

    Bennett, C L

    1999-06-03

    Currently three imaging spectrometer architectures, tunable filter, dispersive, and Fourier transform, are viable for imaging the universe in three dimensions. There are domains of greatest utility for each of these architectures. The optimum choice among the various alternative architectures is dependent on the nature of the desired observations, the maturity of the relevant technology, and the character of the backgrounds. The domain appropriate for each of the alternatives is delineated; both for instruments having ideal performance as well as for instrumentation based on currently available technology. The environment and science objectives for the Next Generation Space Telescope will be used as a specific representative case to provide a basis for comparison of the various alternatives.

  15. An Operational Comparison of Lightning Warning Systems.

    NASA Astrophysics Data System (ADS)

    Johnson, R. L.; Janota, D. E.; Hay, J. E.

    1982-05-01

    During the spring-summer of 1979, six lightning warning devices were evaluated in a side-by-side comparison study at three test sites. Stock commercial devices were selected based upon distinct concepts of operation. The devices tested included a sferics counter, a corona point, a radioactive probe, a field mill, an azimuth/range locator and a triangulation locator. The test sites were chosen to provide varied thunderstorm conditions: 1) San Antonio, Texas (cold air advection), 2) Kennedy Space Center, Florida (localized surface heating) and 3) Langmuir Laboratory, New Mexico (orographic effects). The evaluation parameters were advance warning time, time to clear after hazard, alarm reliability, and false alarm and failure to alarm probabilities. The triangulation locator provided the best overall performance; however, all systems indicated a need for improvement in the failure to alarm rate.

  16. Poultry litter toxicity comparison from various bioassays

    SciTech Connect

    Gupta, G.; Kelly, P. )

    1992-01-01

    Poultry litter contains many toxic chemicals including Cu, As, Pb, Cd, Hg, Se and PCBs. Poultry litter leachate has been shown to be more toxic to marine luminescent organisms (Photobacterium phosphoreum) than other farm animal manures. A comparison of toxicity of the poultry litter leachate was undertaken using various bioassays. The EC{sub 50} (or LC{sub 50}) value for the leachate with the Microtox and Daphnia bioassays was 2.9 g/L/ Nitrobacter and Pseudomonas bioassays were not useful in determining the leachate toxicity because of the nutritional properties of the litter. Poultry litter leachate was found to be mutagenic to strains TA 97, TA 98, TA 100 and TA 102 using the Ames Test.

  17. GCSS Idealized Cirrus Model Comparison Project

    NASA Technical Reports Server (NTRS)

    Starr, David OC.; Benedetti, Angela; Boehm, Matt; Brown, Philip R. A.; Gierens, Klaus; Girard, Eric; Giraud, Vincent; Jakob, Christian; Jensen, Eric; Khvorostyanov, Vitaly; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The GCSS Working Group on Cirrus Cloud Systems (WG2) is conducting a systematic comparison and evaluation of cirrus cloud models. This fundamental activity seeks to support the improvement of models used for climate simulation and numerical weather prediction through assessment and improvement of the "process" models underlying parametric treatments of cirrus cloud processes in large-scale models. The WG2 Idealized Cirrus Model Comparison Project is an initial comparison of cirrus cloud simulations by a variety of cloud models for a series of idealized situations with relatively simple initial conditions and forcing. The models (16) represent the state-of-the-art and include 3-dimensional large eddy simulation (LES) models, two-dimensional cloud resolving models (CRMs), and single column model (SCM) versions of GCMs. The model microphysical components are similarly varied, ranging from single-moment bulk (relative humidity) schemes to fully size-resolved (bin) treatments where ice crystal growth is explicitly calculated. Radiative processes are included in the physics package of each model. The baseline simulations include "warm" and "cold" cirrus cases where cloud top initially occurs at about -47C and -66C, respectively. All simulations are for nighttime conditions (no solar radiation) where the cloud is generated in an ice supersaturated layer, about 1 km in depth, with an ice pseudoadiabatic thermal stratification (neutral). Continuing cloud formation is forced via an imposed diabatic cooling representing a 3 cm/s uplift over a 4-hour time span followed by a 2-hour dissipation stage with no cooling. Variations of these baseline cases include no-radiation and stable-thermal-stratification cases. Preliminary results indicated the great importance of ice crystal fallout in determining even the gross cloud characteristics, such as average vertically-integrated ice water path (IWP). Significant inter-model differences were found. Ice water fall speed is directly

  18. Comparison of select reference management tools.

    PubMed

    Zhang, Yingting

    2012-01-01

    Bibliographic management tools have been widely used by researchers to store, organize, and manage their references for research papers, theses, dissertations, journal articles, and other publications. There are a number of reference management tools available. In order for users to decide which tool is best for their needs, it is important to know each tool's strengths and weaknesses. This article compares four reference management tools, one of which is licensed by University of Medicine and Dentistry of New Jersey libraries and the other three are open source and freely available. They were chosen based on their functionality, ease of use, availability to library users, and popularity. These four tools are EndNote/EndNote Web, Zotero, Connotea, and Mendeley Desktop/Mendeley Web. Each tool is analyzed in terms of the following features: accessing, collecting, organizing, collaborating, and citing/formatting. A comparison table is included to summarize the key features of these tools.

  19. Comparison of the Kepler and Eddington Missions

    NASA Technical Reports Server (NTRS)

    Borucki, William J.; DeVincenzi, D. (Technical Monitor)

    2002-01-01

    The Kepler and Eddington missions are spaceborne photometric missions with similar apertures. Both are capable of finding Earth-size extrasolar planets and both can detect p-mode oscillations in stars. The Kepler mission is optimized to find Earth-size planets in the habitability zone of Solar-like stars and does astroseismology only as incidental science. The Eddington mission appears to be optimized for astroseismology. The Kepler design provides a very large field of view, a low measurement cadence, a heliocentric orbit, and a long mission duration. The demand for a large field-of-view results in a Schmidt design with a massive corrector. However, the use of the corrector allows a 105 square degree FOV and thereby provides 15 times the number of stars at a given magnitude than does the optical design used in Eddington. Because Kepler stares at a single FOV throughout the mission, it does much less astroseismology than Eddington. Other comparisons are also discussed.

  20. Comparison of historical documents for writership

    NASA Astrophysics Data System (ADS)

    Ball, Gregory R.; Pu, Danjun; Stritmatter, Roger; Srihari, Sargur N.

    2010-01-01

    Over the last century forensic document science has developed progressively more sophisticated pattern recognition methodologies for ascertaining the authorship of disputed documents. These include advances not only in computer assisted stylometrics, but forensic handwriting analysis. We present a writer verification method and an evaluation of an actual historical document written by an unknown writer. The questioned document is compared against two known handwriting samples of Herman Melville, a 19th century American author who has been hypothesized to be the writer of this document. The comparison led to a high confidence result that the questioned document was written by the same writer as the known documents. Such methodology can be applied to many such questioned documents in historical writing, both in literary and legal fields.

  1. An agreement coefficient for image comparison

    USGS Publications Warehouse

    Ji, L.; Gallo, K.

    2006-01-01

    Combination of datasets acquired from different sensor systems is necessary to construct a long time-series dataset for remotely sensed land-surface variables. Assessment of the agreement of the data derived from various sources is an important issue in understanding the data continuity through the time-series. Some traditional measures, including correlation coefficient, coefficient of determination, mean absolute error, and root mean square error, are not always optimal for evaluating the data agreement. For this reason, we developed a new agreement coefficient for comparing two different images. The agreement coefficient has the following properties: non-dimensional, bounded, symmetric, and distinguishable between systematic and unsystematic differences. The paper provides examples of agreement analyses for hypothetical data and actual remotely sensed data. The results demonstrate that the agreement coefficient does include the above properties, and therefore is a useful tool for image comparison. ?? 2006 American Society for Photogrammetry and Remote Sensing.

  2. Sheared DNA fragment sizing: comparison of techniques.

    PubMed Central

    Ordahl, C P; Johnson, T R; Caplan, A I

    1976-01-01

    DNA fragmented by conventional French press shearing procedures (30,000 lbs/in2) has a number-average fragment size of 230 base pairs. This is considerably smaller than the 450 base pairs typically reported for DNA sheared by this method. Comparison of 5 sizing techniques indicates that sheared DNA fragment size is overestimated by either measurement of velocity sedimentation or Kleinschmidt Electron Microscopic visualization. Both adsorption grid electron microscopic visualization and gel electrophoresis yield the most reliable estimates of the mean size of small DNA fragment populations. In addition, the assessment of fragment size distribution (not possible from sedimentation analysis) potentially allows more critical evaluation of DNA hybridization and reassociation kinetic and measurement parameters. Images PMID:1034292

  3. A Comparison of Digital Signal Extraction Techniques

    SciTech Connect

    Cunningham, M; Dowla, F

    2004-12-28

    We compare the performance of two methods of digital filtering to detect a radioactive source moving past a gamma-ray sensor. The first method is the box-car filter, which is a standard method used in the detection of a moving radioactive source. The second method is the matched filter, which takes into account the variation in the number of photons absorbed in a gamma-ray sensor as a source moves past the sensor. We optimize both methods to detect a source moving at 5, 10, 15 and 20 mph, and the receiver-operator characteristics of the two techniques are plotted for comparison. The improvement of the matched filter over the box car filter is 27% at 5 mph and 22% at 10 mph for a 90% probability of detection and an average hours between false alarms equal to 10.

  4. Historical comparisons of IRI and early ionograms

    NASA Astrophysics Data System (ADS)

    Rice, Donald; Sojka, Jan J.

    2015-04-01

    The IRI2012 provides ionospheric modeling from 1 January 1958 through the present and near future. However, archives of ionogram films exist dating back to the late 1940s, and are potentially valuable for studying long-term trends and change. IRI is very useful for the analysis and interpretation of the films, so Space Environment Corporation (SEC) has modified IRI2012 to extend its operations back to 1 January 1950. This paper describes results from IRI2012 and observations from the Washington DC ionosonde WA938 (38.7°N, -77.1°E) for 1951 (active post-solar maximum) and 1954 (quiet solar minimum). The comparison shows general agreement between the extended IRI2012 and the ionosonde observations. A nighttime enhancement found in IRI results is observed in some ionograms, with modification by atmospheric waves. A significant discrepancy between IRI and observations was found in nighttime 1954 solar minimum results.

  5. Population aging: a comparison among industrialized countries.

    PubMed

    Anderson, G F; Hussey, P S

    2000-01-01

    Increasing longevity and declining fertility rates are shifting the age distribution of populations in industrialized countries toward older age groups. Some countries will experience this demographic shift before others will. In this DataWatch we compare the effects of population aging on health spending, retirement policies, use of long-term care services, workforce composition, and income across eight countries: Australia, Canada, France, Germany, Japan, New Zealand, the United Kingdom, and the United States. International comparisons suggest that the United States is generally well positioned to cope with population aging; however, three areas should be carefully monitored: heavy reliance on private-sector funding of retirement, coverage of pharmaceuticals for the elderly, and a high proportion of private long-term care financing.

  6. Comparison of iohexol with metrizamide in myelography

    SciTech Connect

    Sortland, O.; Nestvold, K.; Kloster, R.; Aandahl, M.H.

    1984-04-01

    Myelography of the lumbar and lower thoracic spine was performed in 46 patients (23 using metrizamide and 23 using iohexol) as a parallel double blind randomized study. Neurological examinations, laboratory testing, and EEG studies were performed before and after myelography, and side effects were recorded. On comparison, adverse reactions were observed in a statistically significant lower number of patients when iohexol was used. The frequency and duration of each single adverse reaction was also lower following use of iohexol, but this was not statistically significant. Three patients had severe reactions following use of metrizamide, and in one patient sharp waves were recorded on EEG. No severe reactions, no mental reactions, and no muscular symptoms were seen following use of iohexol, and the authors consider this contrast medium better tolerated in the subarachnoid space than metrizamide.

  7. Asteroseismic versus Gaia distances: A first comparison

    NASA Astrophysics Data System (ADS)

    De Ridder, J.; Molenberghs, G.; Eyer, L.; Aerts, C.

    2016-10-01

    Context. The Kepler space mission led to a large number of high-precision time series of solar-like oscillators. Using a Bayesian analysis that combines asteroseismic techniques and additional ground-based observations, the mass, radius, luminosity, and distance of these stars can be estimated with good precision. This has given a new impetus to the research field of galactic archeology. Aims: The first data release of the Gaia space mission contains the Tycho-Gaia Astrometric Solution (TGAS) catalogue with parallax estimates for more than 2 million stars, including many of the Kepler targets. Our goal is to make a first proper comparison of asteroseismic and astrometric parallaxes of a selection of dwarfs, subgiants, and red giants observed by Kepler for which asteroseismic distances were published. Methods: We compare asteroseismic and astrometric distances of solar-like pulsators using an appropriate statistical errors-in-variables model on a linear and on a logarithmic scale. Results: For a sample of 22 dwarf and subgiant solar-like oscillators, the TGAS parallaxes considerably improved on the Hipparcos data, yet the excellent agreement between asteroseismic and astrometric distances still holds. For a sample of 938 Kepler pulsating red giants, the TGAS parallaxes are much more uncertain than the asteroseismic ones, making it worthwhile to validate the former with the latter. From errors-in-variables modelling we find a significant discrepancy between the TGAS parallaxes and the asteroseismic values. Conclusions: For the sample of dwarfs and subgiants, the comparison between astrometric and asteroseismic parallaxes does not require a revision of the stellar models on the basis of TGAS. For the sample of red giants, we identify possible causes of the discrepancy, which we will likely be able to resolve with the more precise Gaia parallaxes in the upcoming releases.

  8. Mid-Piacenzian Data-Model Comparison

    NASA Astrophysics Data System (ADS)

    Dowsett, Harry; Robinson, Marci; Haywood, Alan; Valdes, Paul; Salzmann, Ulrich; Hill, Dan; Foley, Kevin; Williams, Mark

    2010-05-01

    The Pliocene Research, Interpretation and Synoptic Mapping (PRISM) Project aims to accurately and comprehensively reconstruct and understand mid-Pliocene climate conditions in order to gain insight into a warmer than present world that may resemble a future climate. PRISM has demonstrated a sustained and dedicated commitment to provide the paleoclimate modeling community with a mid-Piacenzian paleoenvironmental reconstruction of important boundary conditions for use in model initialization and verification. PRISM is presently in its fourth phase as reconstructions are constantly improved, refined and updated to meet this unique goal. A summary of the development of the PRISM data set will be presented. In this presentation we compare the PRISM3D reconstruction to the HadCM3 coupled ocean atmosphere model simulation of mid-Piacenzian climate. While there is overall agreement between data and model, several regions can be highlighted where disagreement is significant and requires further analysis. For example, high latitude warming shown by multiple proxies is not reflected to the same degree in model results. Low latitude warming shown by the model is still difficult to reconcile with faunal data, but the gap between the two results has diminished relative to previous data-model comparisons. The concept of a "permanent El Nino" while evident in mean conditions, is not reflected in further analyses of either model or data. With the recognition that future climate conditions near the end of this century may be somewhat similar to conditions during the mid-Piacenzian, the PRISM reconstruction, coupled with independent paleoclimate proxy data, represents a unique and invaluable tool for paleoclimate and future global change research. Similarly, data-model comparisons such as this one are integral to refining both the data-based reconstructions and the climate models themselves in order to improve confidence in model simulations.

  9. SUPPLEMENTARY COMPARISON: SIM.QM-S1: Bilateral comparison of NIST and CENAM binary gas mixtures

    NASA Astrophysics Data System (ADS)

    Guenther, Frank; Perez-Castorena, Alejandro

    2009-01-01

    Ten compressed gas cylinders from NIST containing binary mixtures with propane, carbon monoxide, carbon dioxide or nitric oxide, all of them with nitrogen balance, were shipped to CENAM for the purpose of bilateral comparison between CENAM and NIST. CENAM utilized its own gravimetrically prepared Primary Reference Materials (PRM) to measure the respective concentrations and reported to NIST. The cylinders were shipped back to NIST for verification of their value. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by SIM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  10. SUPPLEMENTARY COMPARISON Technically enhanced naturally occurring radionuclides (TENORM) in phosphogypsum: Comparison CCRI(II)-S5

    NASA Astrophysics Data System (ADS)

    Shakhashiro, A.; Sansone, U.; Wershofen, H.; Bollhöfer, A.; Kim, C. K.; Kim, C. S.; Korun, M.; Moune, M.; Lee, S. H.; Tarjan, S.

    2010-01-01

    Within the frame of mutual cooperation between the IAEA and the BIPM, the Consultative Committee for Ionizing Radiation Section II—Measurement of Radionuclides accepted an IAEA-organized interlaboratory comparison in 2008 on the determination of technically enhanced naturally occurring radionuclides in phosphogypsum. The study was piloted by the Chemistry Unit at the IAEA's Laboratories in Seibersdorf (Austria). This report presents the methodology applied in conducting this comparison and the results. Activity results for Pb-210, Ra-226, Th-230, U-234, U-235 and U-238 were reported by three national metrology institutes (NMI) and five other expert laboratories or designated institutes. Four different approaches were used to calculate the nominal value of the reported results and associated uncertainties, and the results from each individual participant were evaluated and compared with this nominal reference value. The reported evaluation of the measurement results demonstrated agreement amongst the participating laboratories. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section II, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  11. Regional comparison of absolute gravimeters, EURAMET.M.G-K2 key comparison

    NASA Astrophysics Data System (ADS)

    Pálinkáš, V.; Francis, O.; Val'ko, M.; Kostelecký, J.; Van Camp, M.; Castelein, S.; Bilker-Koivula, M.; Näränen, J.; Lothhammer, A.; Falk, R.; Schilling, M.; Timmen, L.; Iacovone, D.; Baccaro, F.; Germak, A.; Biolcati, E.; Origlia, C.; Greco, F.; Pistorio, A.; De Plaen, R.; Klein, G.; Seil, M.; Radinovic, R.; Reudink, R.; Dykowski, P.; Sȩkowski, M.; Próchniewicz, D.; Szpunar, R.; Mojzeš, M.; Jańk, J.; Papčo, J.; Engfeldt, A.; Olsson, P. A.; Smith, V.; van Westrum, D.; Ellis, B.; Lucero, B.

    2017-01-01

    In the framework of the regional EURAMET.M.G-K2 comparison of absolute gravimeters, 17 gravimeters were compared in November 2015. Four gravimeters were from different NMIs and DIs, they were used to link the regional comparison to the CCM.G.K2 by means of linking converter. Combined least-squares adjustments with weighted constraint was used to determine KCRV. Several pilot solutions are presented and compared with the official solution to demonstrate influences of different approaches (e.g. definition of weights and the constraint) on results of the adjustment. In case of the official solution, all the gravimeters are in equivalence with declared uncertainties. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  12. Using Paired Comparisons to Assess Maslow's Hierarchy of Needs.

    ERIC Educational Resources Information Center

    Strong, Lisa L.; Fiebert, Martin S.

    Past studies which have examined need levels have identified individuals as functioning at specific need levels without an adequate assessment of the intensity of each need or a clear comparison with other need levels. To address these issues, a self-report inventory using a modified paired comparison format was developed to assess need potencies…

  13. Using Comparison to Develop Flexibility for Teaching Algebra

    ERIC Educational Resources Information Center

    Yakes, Christopher; Star, Jon R.

    2011-01-01

    In this paper, we describe a one-day professional development activity for mathematics teachers that promoted the use of comparison as an instructional tool to develop students' flexibility in algebra. Effective use of comparison in mathematics instruction involves using side-by-side presentation of problems and solution methods and subsequent…

  14. Cache-Cache Comparison for Supporting Meaningful Learning

    ERIC Educational Resources Information Center

    Wang, Jingyun; Fujino, Seiji

    2015-01-01

    The paper presents a meaningful discovery learning environment called "cache-cache comparison" for a personalized learning support system. The processing of seeking hidden relations or concepts in "cache-cache comparison" is intended to encourage learners to actively locate new knowledge in their knowledge framework and check…

  15. Comparison of JPL and European Environmental Testing Standards

    NASA Technical Reports Server (NTRS)

    Man, Kin Fung; Forgave, John C.; Hoffman, Alan R.

    2006-01-01

    A comparison of JPL and European environmental testing standards is presented. The contents include: 1) JPL Environmental Testing Documents; 2) Focus of the Comparison; 3) Test Policy; 4) Documentation; 5) Programmatics; 6) Functional Testing; 7) Reporting; 8) Dynamics Test Levels, Durations, & Margins; 9) Thermal Test Levels, Durations, & Margins; and 10) EMC Test Levels, Durations, & Margins.

  16. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Conducting the comparison study. 761.326 Section 761.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC...-liquid PCB Remediation Waste Samples § 761.326 Conducting the comparison study. Extract or analyze...

  17. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Conducting the comparison study. 761.326 Section 761.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC...-liquid PCB Remediation Waste Samples § 761.326 Conducting the comparison study. Extract or analyze...

  18. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Conducting the comparison study. 761.326 Section 761.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC...-liquid PCB Remediation Waste Samples § 761.326 Conducting the comparison study. Extract or analyze...

  19. International Comparisons of Inservice Professional Development. Working Paper Series.

    ERIC Educational Resources Information Center

    Gilford, Dorothy M.

    This report recommends items from international comparative education studies that are related to inservice professional development (IPD) for possible inclusion in the Schools and Staffing Survey of 1999-2000. To justify these recommendations, the value of international comparisons and of state and nation comparisons generally is discussed, along…

  20. Item Response Modeling of Paired Comparison and Ranking Data

    ERIC Educational Resources Information Center

    Maydeu-Olivares, Alberto; Brown, Anna

    2010-01-01

    The comparative format used in ranking and paired comparisons tasks can significantly reduce the impact of uniform response biases typically associated with rating scales. Thurstone's (1927, 1931) model provides a powerful framework for modeling comparative data such as paired comparisons and rankings. Although Thurstonian models are generally…

  1. Finding a Comparison Group: Is Online Crowdsourcing a Viable Option?

    ERIC Educational Resources Information Center

    Azzam, Tarek; Jacobson, Miriam R.

    2013-01-01

    This article explores the viability of online crowdsourcing for creating matched-comparison groups. This exploratory study compares survey results from a randomized control group to survey results from a matched-comparison group created from Amazon.com's MTurk crowdsourcing service to determine their comparability. Study findings indicate…

  2. Group Comparisons of Mathematics Performance from a Cognitive Diagnostic Perspective

    ERIC Educational Resources Information Center

    Chen, Yi-Hsin; Ferron, John M.; Thompson, Marilyn S.; Gorin, Joanna S.; Tatsuoka, Kikumi K.

    2010-01-01

    Traditional comparisons of test score means identify group differences in broad academic areas, but fail to provide substantive description of how the groups differ on the specific cognitive attributes required for success in the academic area. The rule space method (RSM) allows for group comparisons at the cognitive attribute level, which…

  3. General Atomics Pulsed Power Capacitor Comparison Test Report

    DTIC Science & Technology

    2015-07-01

    Comparison Test Report by Richard L Thomas Sensors and Electron Devices Directorate, ARL Approved for public release...REPORT TYPE Final 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE General Atomics Pulsed Power Capacitor Comparison Test Report 5a. CONTRACT

  4. A Note on Multigroup Comparisons Using SAS PROC CALIS

    ERIC Educational Resources Information Center

    Jones-Farmer, L. Allison; Pitts, Jennifer P.; Rainer, R. Kelly

    2008-01-01

    Although SAS PROC CALIS is not designed to perform multigroup comparisons, it is believed that SAS can be "tricked" into doing so for groups of equal size. At present, there are no comprehensive examples of the steps involved in performing a multigroup comparison in SAS. The purpose of this article is to illustrate these steps. We demonstrate…

  5. 16 CFR 233.5 - Miscellaneous price comparisons.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Miscellaneous price comparisons. 233.5 Section 233.5 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES AGAINST DECEPTIVE PRICING § 233.5 Miscellaneous price comparisons. The practices covered in the provisions set...

  6. 16 CFR 233.5 - Miscellaneous price comparisons.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Miscellaneous price comparisons. 233.5 Section 233.5 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES AGAINST DECEPTIVE PRICING § 233.5 Miscellaneous price comparisons. The practices covered in the provisions set...

  7. 16 CFR 233.5 - Miscellaneous price comparisons.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Miscellaneous price comparisons. 233.5 Section 233.5 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES AGAINST DECEPTIVE PRICING § 233.5 Miscellaneous price comparisons. The practices covered in the provisions set...

  8. 16 CFR 233.5 - Miscellaneous price comparisons.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Miscellaneous price comparisons. 233.5 Section 233.5 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES AGAINST DECEPTIVE PRICING § 233.5 Miscellaneous price comparisons. The practices covered in the provisions set...

  9. 16 CFR 233.5 - Miscellaneous price comparisons.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Miscellaneous price comparisons. 233.5 Section 233.5 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES AGAINST DECEPTIVE PRICING § 233.5 Miscellaneous price comparisons. The practices covered in the provisions set...

  10. Selecting Evaluation Comparison Groups: A Cluster Analytic Approach.

    ERIC Educational Resources Information Center

    Davis, Todd Mclin; McLean, James E.

    A persistent problem in the evaluation of field-based projects is the lack of no-treatment comparison groups. Frequently, potential comparison groups are confounded by socioeconomic, racial, or other factors. Among the possible methods for dealing with this problem are various matching procedures, but they are cumbersome to use with multiple…

  11. Model Comparison of Bayesian Semiparametric and Parametric Structural Equation Models

    ERIC Educational Resources Information Center

    Song, Xin-Yuan; Xia, Ye-Mao; Pan, Jun-Hao; Lee, Sik-Yum

    2011-01-01

    Structural equation models have wide applications. One of the most important issues in analyzing structural equation models is model comparison. This article proposes a Bayesian model comparison statistic, namely the "L[subscript nu]"-measure for both semiparametric and parametric structural equation models. For illustration purposes, we consider…

  12. Choosing a Multiple Comparison Procedure Based on Alpha.

    ERIC Educational Resources Information Center

    Barnette, J. Jackson; McLean, James E.

    Four of the most commonly used multiple comparison procedures were compared for pairwise comparisons and relative to control of per-experiment and experimentwise Type I errors when conducted as protected or unprotected tests. The methods are: (1) Dunn-Bonferroni; (2) Dunn-Sidak; (3) Holm's sequentially rejective; and (4) Tukey's honestly…

  13. Numerical Order and Quantity Processing in Number Comparison

    ERIC Educational Resources Information Center

    Turconi, Eva; Campbell, Jamie I. D.; Seron, Xavier

    2006-01-01

    We investigated processing of numerical order information and its relation to mechanisms of numerical quantity processing. In two experiments, performance on a quantity-comparison task (e.g. 2 5; which is larger?) was compared with performance on a relative-order judgment task (e.g. 2 5; ascending or descending order?). The comparison task…

  14. Automatic comparison of striation information on firearm bullets

    NASA Astrophysics Data System (ADS)

    Puente Leon, Fernando; Beyerer, Juergen

    1999-08-01

    This paper deals with an important task within forensic science - the automatic comparison of bullets for the purpose of firearm identification. Bullets bear groove- shaped marks that can be though of as a kind of 'fingerprint' of the firearm on their circumferential surface. To accomplish the comparison task, mainly the fine grooves on the bullet surface are of interests.

  15. Gender Differences in Comparisons and Entitlement: Implications for Comparable Worth.

    ERIC Educational Resources Information Center

    Major, Brenda

    1989-01-01

    Addresses the role of comparison processes in the persistence of the gender wage gap, its toleration by those disadvantaged by it, and resistance to comparable worth as a corrective strategy. Argues that gender segregation and undercompensation for women's jobs leads women to use different comparison standards when evaluating what they deserve.…

  16. [Apples with oranges? Comparison of scientometric indicators between fields].

    PubMed

    Schubert, András

    2016-04-17

    It is well known that all scientometric indicators strongly depend on research fields. Therefore, there is a certain reluctance to make any cross-field comparison of these indicators. The paper reviews the possibilities to normalize the most important scientometric indicators: publication counts, citation rate or h-index, thus making them suitable for cross-field comparison.

  17. Unlimited Capacity Parallel Quantity Comparison of Multiple Integers

    ERIC Educational Resources Information Center

    Blanc-Goldhammer, Daryn R.; Cohen, Dale J.

    2014-01-01

    Research has shown that integer comparison is quick and efficient. This efficiency may be a function of the structure of the integer comparison system. The present study tests whether integers are compared with an unlimited capacity system or a limited capacity system. We tested these models using a visual search task with time delimitation. The…

  18. A Comparison of Gregg Diamond Jubilee and Century 21 Shorthand.

    ERIC Educational Resources Information Center

    Gallion, Leona M.; Kavan, C. Bruce

    A comparison of the components of the Gregg Diamond Jubilee shorthand and Century 21 shorthand systems was studied based on the 2,500 most frequently used words in business and communications. Comparisons were analyzed for the following areas: (1) number of class sessions necessary to teach the theory portion of the system, (2) number of words…

  19. Comparison of INMARSAT and ATS3 satellite communication

    SciTech Connect

    Not Available

    1993-03-29

    There exists a need to provide communication through a satellite- based network which allows a user to communicate from a remote site to a fixed site. This discussion provides a comparison, both technical and financial, between the existing ATS3 satellite system and the commercial INMARSAT system. This comparison identified the limitations of each system to provide various types of communication.

  20. RDV77 VLBA Hardware/Software Correlator Comparisons

    NASA Technical Reports Server (NTRS)

    Gordon, David

    2010-01-01

    Results of a hardware vs. software correlation of the RDV77 session are presented. Group delays are found to agree (WRMS differences) at an average level of 4.2 psec and with a noise floor of 2.5 psec. These RDV77 comparisons agree well with several previous correlator comparison studies.

  1. On-Going Comparison of Advanced Fuel Cycle Options

    SciTech Connect

    Piet, S.J.; Bennett, R.G.; Dixon, B.W.; Herring, J.S.; Shropshire, D.E.; Roth, M.; Smith, J.D.; Finck, P.; Hill, R.; Laidler, J.; Pasamehmetoglu, K.

    2004-10-03

    This paper summarizes the current comprehensive comparison of four major fuel cycle strategies: once-through, thermal recycle, thermal+fast recycle, fast recycle. It then proceeds to summarize comparison of the major technology options for the key elements of the fuel cycle that can implement each of the four strategies - separation processing, transmutation reactors, and fuels.

  2. Learning Radiological Appearances of Diseases: Does Comparison Help?

    ERIC Educational Resources Information Center

    Kok, Ellen M.; de Bruin, Anique B. H.; Robben, Simon G. F.; van Merrienboer, Jeroen J. G.

    2013-01-01

    Comparison learning is a promising approach for learning complex real-life visual tasks. When medical students study radiological appearances of diseases, comparison of images showing diseases with images showing no abnormalities could help them learn to discriminate relevant, disease-related information. Medical students studied 12 diseases on…

  3. Task Characteristics and Target Choice in Social Comparison.

    ERIC Educational Resources Information Center

    Gorenflo, Daniel W.

    Festinger's (1954) theory of social comparison holds that in the absence of objective standards, people use the attitudes or judgments of similar others to determine the correctness of their own positions. More recent studies have suggested, however, that people often prefer dissimilar comparison targets. A study was undertaken to examine the…

  4. Social Comparison of Ability in Blind Children and Adolescents.

    ERIC Educational Resources Information Center

    Morin, Stephen F.; Jones, Reginald L.

    Forty-five blind, school aged subjects (aged 6-18 years) were questioned to determine the influence of age on the choice of the blind as a reference group for social comparison of abilities. To assess the direction of social comparison behavior, each subject was presented with a replication of three questions (which differed in the degree to which…

  5. Optimism, Social Comparisons, and Coping with Vision Loss in Israel

    ERIC Educational Resources Information Center

    Ben-Zur, Hasida; Debi, Zoharit

    2005-01-01

    This study of 90 adults (aged 55?80) who lost their vision assessed their dispositional optimism, social comparisons, coping strategies, and wellbeing. The findings suggest that optimism and positive social comparisons play an important role in stimulating the motivation to cope adaptively with vision loss and that enhancing optimism and social…

  6. KEY COMPARISON: Final report, on-going key comparison BIPM.QM-K1: Ozone at ambient level, comparison with ISCIII, 2007

    NASA Astrophysics Data System (ADS)

    Viallon, Joële; Moussay, Philippe; Wielgosz, Robert; Morillo Gomez, Pilar; Sánchez Blaya, Carmen

    2009-01-01

    As part of the on-going key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of the Instituto de Salud Carlos III (ISCIII) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone mole fraction range of 0 nmol/mol to 500 nmol/mol. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  7. Comparisons of absolute gravimeters (COOMET.M.G-S1)

    NASA Astrophysics Data System (ADS)

    Vinnichenko, Mr Alexander; Germak, Alessandro, Dr

    2017-01-01

    This report describes the results of the RMO supplementary comparison COOMET.M.G-S1 (also known as bilateral comparison COOMET 634/UA/14). The comparison measurements between the two participants NSC 'IM' (pilot laboratory) and INRIM were started in December 2015 and finished in January 2016. Participants of comparisons were conducted at their national standards the measurements of the free fall acceleration in gravimetric point laboratory of absolute gravimetry of INRIM named INRiM.2. Absolute measurements of gravimetric acceleration were conducted by ballistic gravimeters. The agreement between the two participants is good. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  8. Final report of supplementary comparison SIM.M.P-S7: Hydraulic pressure comparison from 7 MPa to 70 MPa

    NASA Astrophysics Data System (ADS)

    Gil Romero, Juan Carlos; Catalina Neira, María; Torres Guzmán, Jorge C.

    2013-01-01

    This report presents the final results of supplementary comparison SIM.M.P-S7 in the field of hydraulic pressure up to 70 MPa, within the PTB-ANDIMET-PLUS project. Seven national pressure reference laboratories participated in this comparison, which started with an opening meeting in November 2011 at the city of Lima; the closing meeting was held at the National Metrology Institute of Colombia INM, at Bogota, on 27-28 November 2012. Each participating laboratory used for the comparison its best hydraulic pressure balance standard in the range from 7 MPa to 70 MPa. The transfer standard for the comparison was a digital manometer DH Instruments Fluke RPM-4 with an accuracy of 0.008% of the reading. The reference laboratory and advisor for the comparison was CENAM, Mexico. The comparison protocol and results analysis was made by the pressure laboratory of National Metrology Institute INM (Colombia) who participated in the comparison as well. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by SIM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  9. A comparison of cosmological hydrodynamic codes

    NASA Technical Reports Server (NTRS)

    Kang, Hyesung; Ostriker, Jeremiah P.; Cen, Renyue; Ryu, Dongsu; Hernquist, Lars; Evrard, August E.; Bryan, Greg L.; Norman, Michael L.

    1994-01-01

    We present a detailed comparison of the simulation results of various hydrodynamic codes. Starting with identical initial conditions based on the cold dark matter scenario for the growth of structure, with parameters h = 0.5 Omega = Omega(sub b) = 1, and sigma(sub 8) = 1, we integrate from redshift z = 20 to z = O to determine the physical state within a representative volume of size L(exp 3) where L = 64 h(exp -1) Mpc. Five indenpendent codes are compared: three of them Eulerian mesh-based and two variants of the smooth particle hydrodynamics 'SPH' Lagrangian approach. The Eulerian codes were run at N(exp 3) = (32(exp 3), 64(exp 3), 128(exp 3), and 256(exp 3)) cells, the SPH codes at N(exp 3) = 32(exp 3) and 64(exp 3) particles. Results were then rebinned to a 16(exp 3) grid with the exception that the rebinned data should converge, by all techniques, to a common and correct result as N approaches infinity. We find that global averages of various physical quantities do, as expected, tend to converge in the rebinned model, but that uncertainites in even primitive quantities such as (T), (rho(exp 2))(exp 1/2) persists at the 3%-17% level achieve comparable and satisfactory accuracy for comparable computer time in their treatment of the high-density, high-temeprature regions as measured in the rebinned data; the variance among the five codes (at highest resolution) for the mean temperature (as weighted by rho(exp 2) is only 4.5%. Examined at high resolution we suspect that the density resolution is better in the SPH codes and the thermal accuracy in low-density regions better in the Eulerian codes. In the low-density, low-temperature regions the SPH codes have poor accuracy due to statiscal effects, and the Jameson code gives the temperatures which are too high, due to overuse of artificial viscosity in these high Mach number regions. Overall the comparison allows us to better estimate errors; it points to ways of improving this current generation ofhydrodynamic

  10. KEY COMPARISON: Key comparison of stainless steel 1 kg mass standards: COOMET.M.M-K1

    NASA Astrophysics Data System (ADS)

    Spurný, Robert; Kolozinska, Irina; Snegov, Viktor; Evsievich, Ludmila; Borys, Michael; Milkamanavičiene, Ilona

    2010-01-01

    The COOMET.M.M-K1 key comparison is an international COOMET comparison of 1 kg stainless steel mass standards, using two travelling artefacts from SMU, Slovakia. Thanks to the participation of the PTB in this comparison, it was made possible to link the results to those of the corresponding CCM key comparison, namely CCM.M-K1, thus adding new values of degrees of equivalence for BelGIM (Belarus), NSC IM (Ukraine), PTB (Germany), SMU (Slovakia), VMT/VMC (Lithuania) and VNIIM (Russia), on the CCM.M-K1 graph of equivalence. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  11. KEY COMPARISON: EURAMET regional key comparison EURAMET.M.FF-K4.b: Volume intercomparison at 20 L

    NASA Astrophysics Data System (ADS)

    Batista, Elsa; Lau, Peter

    2009-01-01

    In the sequence of CIPM key comparisons concerning volume calibrations an interregional comparison CCM.FF-K4 was performed between December 2003 and March 2005 for volume standards of 20 L and 100 mL. The corresponding regional part of this comparison within Europe was performed in 2006 for a 100 mL Gay-Lussac Pycnometer—EUROMET.M.FF-K4 (EUROMET project number 692). It was decided during the EUROMET meeting in Istanbul 2007 to also perform the regional part of this key comparison at 20 L, as EURAMET.M.FF-K4.b (EURAMET project number 1008). This comparison was guided by IPQ (Portugal) with SP (Sweden) acting has the pilot laboratory having taken part in the interregional exercise. Fourteen countries decided to participate in this comparison. One of three 20 L pipettes, 710-04FyV used in the CCM.FF K4, was readjusted by CENAM (Mexico), which initiated this key comparison and produced the transfer standard. The main purpose of this project was to compare the experimental results and uncertainty calculations in calibrating this 20 L pipette and linking the intra-regional European results with the results obtained in the previous inter-regional CIPM key comparison. The results of all laboratories participating in EURAMET project 1008 are presented in this report as well as their equivalence with the reference value of the key comparison CCM.FF-K4. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  12. In Vitro Comparison of Adipokine Export Signals.

    PubMed

    Sharafi, Parisa; Kocaefe, Y Çetin

    2016-01-01

    Mammalian cells are widely used for recombinant protein production in research and biotechnology. Utilization of export signals significantly facilitates production and purification processes. 35 years after the discovery of the mammalian export machinery, there still are obscurities regarding the efficiency of the export signals. The aim of this study was the comparative evaluation of the efficiency of selected export signals using adipocytes as a cell model. Adipocytes have a large capacity for protein secretion including several enzymes, adipokines, and other signaling molecules, providing a valid system for a quantitative evaluation. Constructs that expressed N-terminal fusion export signals were generated to express Enhanced Green Fluorescence Protein (EGFP) as a reporter for quantitative and qualitative evaluation. Furthermore, fluorescent microscopy was used to trace the intracellular traffic of the reporter. The export efficiency of six selected proteins secreted from adipocytes was evaluated. Quantitative comparison of intracellular and exported fractions of the recombinant constructs demonstrated a similar efficiency among the studied sequences with minor variations. The export signal of Retinol Binding Protein (RBP4) exhibited the highest efficiency. This study presents the first quantitative data showing variations among export signals, in adipocytes which will help optimization of recombinant protein distribution.

  13. Method and apparatus for biological sequence comparison

    DOEpatents

    Marr, Thomas G.; Chang, William I-Wei

    1997-01-01

    A method and apparatus for comparing biological sequences from a known source of sequences, with a subject (query) sequence. The apparatus takes as input a set of target similarity levels (such as evolutionary distances in units of PAM), and finds all fragments of known sequences that are similar to the subject sequence at each target similarity level, and are long enough to be statistically significant. The invention device filters out fragments from the known sequences that are too short, or have a lower average similarity to the subject sequence than is required by each target similarity level. The subject sequence is then compared only to the remaining known sequences to find the best matches. The filtering member divides the subject sequence into overlapping blocks, each block being sufficiently large to contain a minimum-length alignment from a known sequence. For each block, the filter member compares the block with every possible short fragment in the known sequences and determines a best match for each comparison. The determined set of short fragment best matches for the block provide an upper threshold on alignment values. Regions of a certain length from the known sequences that have a mean alignment value upper threshold greater than a target unit score are concatenated to form a union. The current block is compared to the union and provides an indication of best local alignment with the subject sequence.

  14. Comparison of Photogrammetric Techniques for Rockfalls Monitoring

    NASA Astrophysics Data System (ADS)

    Buill, Felipe; Amparo Núñez-Andrés, María; Lantada, Nieves; Prades, Albert

    2016-10-01

    The use of Unmanned Aerial Vehicles, UAVs to image capture for monitoring natural hazards has had a major boost for its wide possibilities in the last decade. These are, for example, the studying and monitoring of unstable slopes, glaciers and rocky escarpments. Moreover, to evaluate the risk after a rockfall or debris flow event, for example measuring volume of displaced material, trajectories of blocks or building and/or infrastructure damaged. But the use of these devices requires a specific treatment regarding the studied case and geomatic techniques suitable to get the adequate precision of the movement, size of items or events to study. For each application it is necessary to determine what kind of capture is the most appropriate to obtain an optimal benefit-cost ratio. A comparison of the use of terrestrial photogrammetry, UAV photogrammetry and video from UAV has been done. The best result has been obtained combining techniques aerial and terrestrial since ground points with a best quality can be identified and measured and all the surface has a best image coverage.

  15. VAICo: visual analysis for image comparison.

    PubMed

    Schmidt, Johanna; Gröller, M Eduard; Bruckner, Stefan

    2013-12-01

    Scientists, engineers, and analysts are confronted with ever larger and more complex sets of data, whose analysis poses special challenges. In many situations it is necessary to compare two or more datasets. Hence there is a need for comparative visualization tools to help analyze differences or similarities among datasets. In this paper an approach for comparative visualization for sets of images is presented. Well-established techniques for comparing images frequently place them side-by-side. A major drawback of such approaches is that they do not scale well. Other image comparison methods encode differences in images by abstract parameters like color. In this case information about the underlying image data gets lost. This paper introduces a new method for visualizing differences and similarities in large sets of images which preserves contextual information, but also allows the detailed analysis of subtle variations. Our approach identifies local changes and applies cluster analysis techniques to embed them in a hierarchy. The results of this process are then presented in an interactive web application which allows users to rapidly explore the space of differences and drill-down on particular features. We demonstrate the flexibility of our approach by applying it to multiple distinct domains.

  16. Cephalometric comparison of cesarean and normal births

    PubMed Central

    Goymen, Merve; Topcuoglu, Tolga; Aktan, Ali Murat; Isman, Ozlem

    2016-01-01

    Objective: The aim of this study was to compare cephalometric variables of subjects with normal and cesarean births. Materials and Methods: Ninety age- and gender-matched patients, who were treated in Gaziantep University, Faculty of Dentistry Orthodontics Department were equally divided into normal and cesarean groups according to the birth methods reported by their mothers. To eliminate the negative effects of being different in terms of age and gender among parameters, control, and patient groups were matched in the present study. Pretreatment cephalometrics radiographs were used. Six measurements representing sagittal and vertical relationships were evaluated from pretreatment cephalograms using Dolphin Imaging Orthodontics Software was used in this issue by an orthodontist. Kolmogorov–Smirnov test, Student's t-test, and Mann–Whitney U-test were used for statistical comparisons. Results: A point-nasion-B point angle (ANB) and Wits values were higher in the normal group, while sella-nasion-A point angle, sella-nasion-B point angle, Frankfort horizontal-mandibular plane angle, and gonion-gnathion-SN plane angle values were higher in the cesarean group. However, the groups showed no significant differences (P > 0.05). ANB angle and Wits values showed high correlation. Conclusions: Within the study limitations, the results suggest that the birth method may not have a considerable effect on the development of the craniofacial skeletal system. PMID:27095896

  17. The National Ballistics Imaging Comparison (NBIC) project.

    PubMed

    Song, J; Vorburger, T V; Ballou, S; Thompson, R M; Yen, J; Renegar, T B; Zheng, A; Silver, R M; Ols, M

    2012-03-10

    In response to the guidelines issued by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB-International) to establish traceability and quality assurance in U.S. crime laboratories, a NIST/ATF joint project entitled National Ballistics Imaging Comparison (NBIC) was initialized in 2008. The NBIC project aims to establish a National Traceability and Quality System for ballistics identifications in crime laboratories within the National Integrated Ballistics Information Network (NIBIN) of the U.S. NIST Standard Reference Material (SRM) 2460 bullets and 2461 cartridge cases are used as reference standards. 19 ballistics examiners from 13 U.S. crime laboratories participated in this project. They each performed 24 periodic image acquisitions and correlations of the SRM bullets and cartridge cases over the course of a year, but one examiner only participated in Phase 1 tests of SRM cartridge case. The correlation scores were collected by NIST for statistical analyses, from which control charts and control limits were developed for the proposed Quality System and for promoting future assessments and accreditations for firearm evidence in U.S. forensic laboratories in accordance with the ISO 17025 Standard.

  18. Orion Landing Simulation Eight Soil Model Comparison

    NASA Technical Reports Server (NTRS)

    Mark, Stephen D.

    2009-01-01

    LS-DYNA finite element simulations of a rigid Orion Crew Module (CM) were used to investigate the CM impact behavior on eight different soil models. Ten different landing conditions, characterized by the combination of CM vertical and horizontal velocity, hang angle, and roll angle were simulated on the eight different soils. The CM center of gravity accelerations, pitch angle, kinetic energy, and soil contact forces were the outputs of interest. The simulation results are presented, with comparisons of the CM behavior on the different soils. The soils analyzed in this study can be roughly categorized as soft, medium, or hard, according to the CM accelerations that occur when landing on them. The soft group is comprised of the Carson Sink Wet soil and the Kennedy Space Center (KSC) Low Density Dry Sand. The medium group includes Carson Sink Dry, the KSC High Density In-Situ Moisture Sand and High Density Flooded Sand, and Cuddeback B. The hard soils are Cuddeback A and the Gantry Unwashed Sand. The softer soils were found to produce lower peak accelerations, have more stable pitch behavior, and to be less sensitive to the landing conditions. This investigation found that the Cuddeback A soil produced the highest peak accelerations and worst stability conditions, and that the best landing performance was achieved on the KSC Low Density Dry Sand.

  19. Comparison of Home Retrofit Programs in Wisconsin

    SciTech Connect

    Cunningham, K.; Hannigan, E.

    2013-03-01

    To explore ways to reduce customer barriers and increase home retrofit completions, several different existing home retrofit models have been implemented in the state of Wisconsin. This study compared these programs' performance in terms of savings per home and program cost per home to assess the relative cost-effectiveness of each program design. However, given the many variations in these different programs, it is difficult to establish a fair comparison based on only a small number of metrics. Therefore, the overall purpose of the study is to document these programs' performance in a case study approach to look at general patterns of these metrics and other variables within the context of each program. This information can be used by energy efficiency program administrators and implementers to inform home retrofit program design. Six different program designs offered in Wisconsin for single-family energy efficiency improvements were included in the study. For each program, the research team provided information about the programs' approach and goals, characteristics, achievements and performance. The program models were then compared with performance results -- program cost and energy savings -- to help understand the overall strengths and weaknesses or challenges of each model.

  20. Comparison of Home Retrofit Programs in Wisconsin

    SciTech Connect

    Cunningham, Kerrie; Hannigan, Eileen

    2013-03-01

    To explore ways to reduce customer barriers and increase home retrofit completions, several different existing home retrofit models have been implemented in the state of Wisconsin. This study compared these programs' performance in terms of savings per home and program cost per home to assess the relative cost-effectiveness of each program design. However, given the many variations in these different programs, it is difficult to establish a fair comparison based on only a small number of metrics. Therefore, the overall purpose of the study is to document these programs' performance in a case study approach to look at general patterns of these metrics and other variables within the context of each program. This information can be used by energy efficiency program administrators and implementers to inform home retrofit program design. Six different program designs offered in Wisconsin for single-family energy efficiency improvements were included in the study. For each program, the research team provided information about the programs' approach and goals, characteristics, achievements and performance. The program models were then compared with performance results-program cost and energy savings-to help understand the overall strengths and weaknesses or challenges of each model.

  1. Method and apparatus for biological sequence comparison

    DOEpatents

    Marr, T.G.; Chang, W.I.

    1997-12-23

    A method and apparatus are disclosed for comparing biological sequences from a known source of sequences, with a subject (query) sequence. The apparatus takes as input a set of target similarity levels (such as evolutionary distances in units of PAM), and finds all fragments of known sequences that are similar to the subject sequence at each target similarity level, and are long enough to be statistically significant. The invention device filters out fragments from the known sequences that are too short, or have a lower average similarity to the subject sequence than is required by each target similarity level. The subject sequence is then compared only to the remaining known sequences to find the best matches. The filtering member divides the subject sequence into overlapping blocks, each block being sufficiently large to contain a minimum-length alignment from a known sequence. For each block, the filter member compares the block with every possible short fragment in the known sequences and determines a best match for each comparison. The determined set of short fragment best matches for the block provide an upper threshold on alignment values. Regions of a certain length from the known sequences that have a mean alignment value upper threshold greater than a target unit score are concatenated to form a union. The current block is compared to the union and provides an indication of best local alignment with the subject sequence. 5 figs.

  2. Models comparison for JET polarimeter data

    SciTech Connect

    Mazzotta, C.; Orsitto, F. P.; Giovannozzi, E.; Boboc, A.; Tudisco, O.; Zabeo, L.; Brombin, M.; Murari, A.

    2008-03-12

    A complete comparison between the theory and the measurements in polarimetry was done by using the Far Infrared Polarimeter at JET. More than 300 shots were analyzed, including a wide spectrum of JET scenarios in all critical conditions for polarimetry: high density, high and very low fields, high temperatures.This work is aimed at the demonstration of the robustness of the theoretical models for the JET polarimeter measurements in the perspective of using these models for ITER like plasma scenarios . In this context, an assessment was performed on how the line-integrated plasma density along the central vertical chord of FIR polarimeter could be evaluated using the Cotton-Mouton effect and its possible concrete use to correct fringe jumps of the interferometer.The models considered are: i) the rigorous numerical solution of the Stokes propagation equations, using dielectric tensor evaluated from JET equilibrium and Thomson scattering [1,2]; ii) two types of approximated solutions [2,3] and iii) the Guenther empirical model [4] that considers the mutual effect between Cotton-Mouton and Faraday rotation angle. The model calculations have been compared with polarimeter measurements for the Cotton-Mouton phase shift.The agreement with theory is satisfactory within the limits of experimental errors [3].

  3. Programming Tools: Status, Evaluation, and Comparison

    NASA Technical Reports Server (NTRS)

    Cheng, Doreen Y.; Cooper, D. M. (Technical Monitor)

    1994-01-01

    In this tutorial I will first describe the characteristics of scientific applications and their developers, and describe the computing environment in a typical high-performance computing center. I will define the user requirements for tools that support application portability and present the difficulties to satisfy them. These form the basis of the evaluation and comparison of the tools. I will then describe the tools available in the market and the tools available in the public domain. Specifically, I will describe the tools for converting sequential programs, tools for developing portable new programs, tools for debugging and performance tuning, tools for partitioning and mapping, and tools for managing network of resources. I will introduce the main goals and approaches of the tools, and show main features of a few tools in each category. Meanwhile, I will compare tool usability for real-world application development and compare their different technological approaches. Finally, I will indicate the future directions of the tools in each category.

  4. A comparison of interface tracking methods

    SciTech Connect

    Kothe, D.B.; Rider, W.J.

    1995-03-27

    In this Paper we provide a direct comparison of several important algorithms designed to track fluid interfaces. In the process we propose improved criteria by which these methods are to be judged. We compare and contrast the behavior of the following interface tracking methods: high order monotone capturing schemes, level set methods, volume-of-fluid (VOF) methods, and particle-based (particle-in-cell, or PIC) methods. We compare these methods by first applying a set of standard test problems, then by applying a new set of enhanced problems designed to expose the limitations and weaknesses of each method. We find that the properties of these methods are not adequately assessed until they axe tested with flows having spatial and temporal vorticity gradients. Our results indicate that the particle-based methods are easily the most accurate of those tested. Their practical use, however, is often hampered by their memory and CPU requirements. Particle-based methods employing particles only along interfaces also have difficulty dealing with gross topology changes. Full PIC methods, on the other hand, do not in general have topology restrictions. Following the particle-based methods are VOF volume tracking methods, which are reasonably accurate, physically based, robust, low in cost, and relatively easy to implement. Recent enhancements to the VOF methods using multidimensional interface reconstruction and improved advection provide excellent results on a wide range of test problems.

  5. Santa Barbara Cluster Comparison Test with DISPH

    NASA Astrophysics Data System (ADS)

    Saitoh, Takayuki R.; Makino, Junichiro

    2016-06-01

    The Santa Barbara cluster comparison project revealed that there is a systematic difference between entropy profiles of clusters of galaxies obtained by Eulerian mesh and Lagrangian smoothed particle hydrodynamics (SPH) codes: mesh codes gave a core with a constant entropy, whereas SPH codes did not. One possible reason for this difference is that mesh codes are not Galilean invariant. Another possible reason is the problem of the SPH method, which might give too much “protection” to cold clumps because of the unphysical surface tension induced at contact discontinuities. In this paper, we apply the density-independent formulation of SPH (DISPH), which can handle contact discontinuities accurately, to simulations of a cluster of galaxies and compare the results with those with the standard SPH. We obtained the entropy core when we adopt DISPH. The size of the core is, however, significantly smaller than those obtained with mesh simulations and is comparable to those obtained with quasi-Lagrangian schemes such as “moving mesh” and “mesh free” schemes. We conclude that both the standard SPH without artificial conductivity and Eulerian mesh codes have serious problems even with such an idealized simulation, while DISPH, SPH with artificial conductivity, and quasi-Lagrangian schemes have sufficient capability to deal with it.

  6. Distributed Wind Policy Comparison Tool Guidebook

    SciTech Connect

    Not Available

    2011-11-01

    Power through Policy: 'Best Practices' for Cost-Effective Distributed Wind is a U.S. Department of Energy (DOE)-funded project to identify distributed wind technology policy best practices and to help policymakers, utilities, advocates, and consumers examine their effectiveness using a pro forma model. Incorporating a customized feed from the Database of State Incentives for Renewables and Efficiency (DSIRE), the Web-based Distributed Wind Policy Comparison Tool (Policy Tool) is designed to assist state, local, and utility officials in understanding the financial impacts of different policy options to help reduce the cost of distributed wind technologies. The Policy Tool can be used to evaluate the ways that a variety of federal and state policies and incentives impact the economics of distributed wind (and subsequently its expected market growth). It also allows policymakers to determine the impact of policy options, addressing market challenges identified in the U.S. DOE's '20% Wind Energy by 2030' report and helping to meet COE targets.

  7. Forensic handwriting examiners' expertise for signature comparison.

    PubMed

    Sita, Jodi; Found, Bryan; Rogers, Douglas K

    2002-09-01

    This paper reports on the performance of forensic document examiners (FDEs) in a signature comparison task that was designed to address the issue of expertise. The opinions of FDEs regarding 150 genuine and simulated questioned signatures were compared with a control group of non-examiners' opinions. On the question of expertise, results showed that FDEs were statistically better than the control group at accurately determining the genuineness or non-genuineness of questioned signatures. The FDE group made errors (by calling a genuine signature simulated or by calling a simulated signature genuine) in 3.4% of their opinions while 19.3% of the control group's opinions were erroneous. The FDE group gave significantly more inconclusive opinions than the control group. Analysis of FDEs' responses showed that more correct opinions were expressed regarding simulated signatures and more inconclusive opinions were made on genuine signatures. Further, when the complexity of a signature was taken into account, FDEs made more correct opinions on high complexity signatures than on signatures of lower complexity. There was a wide range of skill amongst FDEs and no significant relationship was found between the number of years FDEs had been practicing and their correct, inconclusive and error rates.

  8. Cost comparisons for SSC magnet dependent systems

    SciTech Connect

    1985-08-15

    An SSC Cost Estimating Task Force was appointed by the SSC Director in May, 1985. The charge to the task force was to perform a detailed review of costs for all superconducting magnet design styles that are under consideration for the SSC. Cost information on five magnet styles was reviewed in detail by the task force members. The basic cost information was developed by participating laboratories and by industry. Details of the procedure and analysis are presented in Chapter III. The purpose of this report is to provide a comparison of all SSC construction project cost information that is dependent on the various magnet styles. It is emphasized that the costs displayed in the tables of this report are not the total costs for an SSC construction project. Only those systems for which costs vary with magnet style are included. In Appendix E, current results are compared with the relevant parts of the 1984 SSC Reference Designs Study (RDS) cost estimate. Following the method used in the RDS, the costs that are developed here are non-site specific. The labor rates utilized are based on a national average for the various labor categories. The Conventional Systems costs for underground structures are derived from an extension of the ``median-site`` model as described in the RDS.

  9. Experimental comparison of two quantum computing architectures

    PubMed Central

    Linke, Norbert M.; Maslov, Dmitri; Roetteler, Martin; Debnath, Shantanu; Figgatt, Caroline; Landsman, Kevin A.; Wright, Kenneth; Monroe, Christopher

    2017-01-01

    We run a selection of algorithms on two state-of-the-art 5-qubit quantum computers that are based on different technology platforms. One is a publicly accessible superconducting transmon device (www.research.ibm.com/ibm-q) with limited connectivity, and the other is a fully connected trapped-ion system. Even though the two systems have different native quantum interactions, both can be programed in a way that is blind to the underlying hardware, thus allowing a comparison of identical quantum algorithms between different physical systems. We show that quantum algorithms and circuits that use more connectivity clearly benefit from a better-connected system of qubits. Although the quantum systems here are not yet large enough to eclipse classical computers, this experiment exposes critical factors of scaling quantum computers, such as qubit connectivity and gate expressivity. In addition, the results suggest that codesigning particular quantum applications with the hardware itself will be paramount in successfully using quantum computers in the future. PMID:28325879

  10. Comparison of fabrication techniques for hollow retroreflectors

    NASA Astrophysics Data System (ADS)

    Preston, Alix; Merkowitz, Stephen

    2014-06-01

    Despite the wide usage of hollow retroreflectors, there is limited literature involving their fabrication techniques and only two documented construction methods could be found. One consists of an adjustable fixture that allows for the independent alignment of each mirror, while the other consists of a modified solid retroreflector that is used as a mandrel. Although both methods were shown to produce hollow retroreflectors with arc second dihedral angle errors, a comparison and analysis of each method could not be found, which makes it difficult to ascertain which method would be better suited to use for precision-aligned retroreflectors. Although epoxy bonding is generally the preferred method to adhere the three mirrors, a relatively new method known as hydroxide-catalysis bonding (HCB) presents several potential advantages over epoxy bonding. HCB has been used to bond several optical components for space-based missions, but has never been applied for construction of hollow retroreflectors. We examine the benefits and limitations of each bonding fixture as well as the present results and analysis of hollow retroreflectors made using both epoxy and HCB techniques.

  11. A Comparison of Simulation Capabilities for Ducts

    SciTech Connect

    Miller, William A.; Smith, Matt K.; Gu, Lixing; New, Joshua Ryan

    2014-11-01

    Typically, the cheapest way to install a central air conditioning system in residential buildings is to place the ductwork in the attic. Energy losses due to duct-attic interactions can be great, but current whole-house models are unable to capture the dynamic multi-mode physics of the interactions. The building industry is notoriously fragmented and unable to devote adequate research resources to solve this problem. Builders are going to continue to put ducts in the attic because floor space is too expensive to closet them within living space, and there are both construction and aesthetic issues with other approaches such as dropped ceilings. Thus, there is a substantial need to publicly document duct losses and the cost of energy used by ducts in attics so that practitioners, builders, homeowners and state and federal code officials can make informed decisions leading to changes in new construction and additional retrofit actions. Thus, the goal of this study is to conduct a comparison of AtticSim and EnergyPlus simulation algorithms to identify specific features for potential inclusion in EnergyPlus that would allow higher-fidelity modeling of HVAC operation and duct transport of conditioned air. It is anticipated that the resulting analysis from these simulation tools will inform energy decisions relating to the role of ducts in future building energy codes and standards.

  12. Comparison of modern icing cloud instruments

    NASA Technical Reports Server (NTRS)

    Takeuchi, D. M.; Jahnsen, L. J.; Callander, S. M.; Humbert, M. C.

    1983-01-01

    Intercomparison tests with Particle Measuring Systems (PMS) were conducted. Cloud liquid water content (LWC) measurements were also taken with a Johnson and Williams (JW) hot-wire device and an icing rate device (Leigh IDS). Tests include varying cloud LWC (0.5 to 5 au gm), cloud median volume diameter (MVD) (15 to 26 microns), temperature (-29 to 20 C), and air speeds (50 to 285 mph). Comparisons were based upon evaluating probe estimates of cloud LWC and median volume diameter for given tunnel settings. Variations of plus or minus 10% and plus or minus 5% in LWC and MVD, respectively, were determined of spray clouds between test made at given tunnel settings (fixed LWC, MVD, and air speed) indicating cloud conditions were highly reproducible. Although LWC measurements from JW and Leigh devices were consistent with tunnel values, individual probe measurements either consistently over or underestimated tunnel values by factors ranging from about 0.2 to 2. Range amounted to a factor of 6 differences between LWC estimates of probes for given cloud conditions. For given cloud conditions, estimates of cloud MVD between probes were within plus or minus 3 microns and 93% of the test cases. Measurements overestimated tunnel values in the range between 10 to 20 microns. The need for improving currently used calibration procedures was indicated. Establishment of test facility (or facilities) such as an icing tunnel where instruments can be calibrated against known cloud standards would be a logical choice.

  13. Detectivity comparison of bolometric optical antennas

    NASA Astrophysics Data System (ADS)

    Cuadrado, Alexander; López-Alonso, José M.; Martínez-Antón, Juan C.; Ezquerro, Jose M.; González, Francisco J.; Alda, Javier

    2015-08-01

    The practical application of optical antennas in detection devices strongly depends on its ability to produce an acceptable signal-to-noise ratio for the given task. It is known that, due to the intrinsic problems arising from its sub-wavelength dimensions, optical antennas produce very small signals. The quality of these signals depends on the involved transduction mechanism. The contribution of different types of noise should be adapted to the transducer and to the signal extraction regime. Once noise is evaluated and measured, the specific detectivity, D*, becomes the parameter of interest when comparing the performance of antenna coupled devices with other detectors. However, this parameter involves some magnitudes that can be defined in several ways for optical antennas. In this contribution we are interested in the evaluation and comparison of D_ values for several bolometric optical antennas working in the infrared and involving two materials. At the same time, some material and geometrical parameters involved in the definition of noise and detectivity will be discussed to analyze the suitability of D_ to properly account for the performance of optical antennas.

  14. Method Comparison (Agreement) Studies: Myths and Rationale

    PubMed Central

    Nimbalkar, Somashekhar M

    2017-01-01

    Unprecedented technological growth in the last quarter of twentieth century has resulted in improved health care and opened new domains of health care research. This technological leap also facilitated the paradigm shift from hospital care to home care through development of ‘point of care’ devices. As early diagnoses and timely referral is a key to health management, these devices play an important role in improving health. Validation of the new technology in different settings is necessary before adopting it to practice. For a binary result like pregnancy test, it is trivial to use statistical tools like sensitivity, specificity etc. For a continuous variable like blood glucose level the analysis is not straightforward. Many of us misinterpret ‘association’ as ‘agreement’. This misinterpretation is reflected in studies which have compared two different technologies. The findings of well conducted studies do not contribute to the evidence base just because of wrong analysis strategy. We delineate on finer nuances of analysis and interpretation of method comparison studies. PMID:28273982

  15. Valuing Science: A Turkish-American comparison

    NASA Astrophysics Data System (ADS)

    Titrek, Osman; Cobern, William W.

    2011-02-01

    The process of modernization began in Turkey under the reform government of Mustafa Kemal Ataturk (1881-1938). Turkey officially became a secular nation seeking to develop a modern economy with modern science and technology and political democracy. Turkey also has long been, and remains, a deeply religious society. Specifically, the practice of Islam is widespread, which raises the important question: whether the path of modernization in Turkey will look more like the American pattern or the European, where the Europeans are much more philosophically secular than the Americans? One way to look at this question is by examining how people value science vis-à-vis other important aspects of society and culture. Hence, our study is a comparative look at Turkish and American opinions about science. The American society, which is certainly a very modern society, is of particular interest in Turkey, given the significant religiosity of the American people, making the American and Turkish societies similar at least on this one significant point. Although we do not have comparable European data at this time, our Turkish-American comparison can be suggestive of whether or not Turkey is likely to follow the American pattern of a highly modernized yet deeply religious society.

  16. Pedestal stability comparison and ITER pedestal prediction

    NASA Astrophysics Data System (ADS)

    Snyder, P. B.; Aiba, N.; Beurskens, M.; Groebner, R. J.; Horton, L. D.; Hubbard, A. E.; Hughes, J. W.; Huysmans, G. T. A.; Kamada, Y.; Kirk, A.; Konz, C.; Leonard, A. W.; Lönnroth, J.; Maggi, C. F.; Maingi, R.; Osborne, T. H.; Oyama, N.; Pankin, A.; Saarelma, S.; Saibene, G.; Terry, J. L.; Urano, H.; Wilson, H. R.

    2009-08-01

    The pressure at the top of the edge transport barrier (or 'pedestal height') strongly impacts fusion performance, while large edge localized modes (ELMs), driven by the free energy in the pedestal region, can constrain material lifetimes. Accurately predicting the pedestal height and ELM behavior in ITER is an essential element of prediction and optimization of fusion performance. Investigation of intermediate wavelength MHD modes (or 'peeling-ballooning' modes) has led to an improved understanding of important constraints on the pedestal height and the mechanism for ELMs. The combination of high-resolution pedestal diagnostics, including substantial recent improvements, and a suite of highly efficient stability codes, has made edge stability analysis routine on several major tokamaks, contributing both to understanding, and to experimental planning and performance optimization. Here we present extensive comparisons of observations to predicted edge stability boundaries on several tokamaks, both for the standard (Type I) ELM regime, and for small ELM and ELM-free regimes. We further discuss a new predictive model for the pedestal height and width (EPED1), developed by self-consistently combining a simple width model with peeling-ballooning stability calculations. This model is tested against experimental measurements, and used in initial predictions of the pedestal height for ITER.

  17. FRET or no FRET: a quantitative comparison.

    PubMed

    Berney, Claude; Danuser, Gaudenz

    2003-06-01

    Fluorescence resonance energy transfer (FRET) is a technique used to measure the interaction between two molecules labeled with two different fluorophores (the donor and the acceptor) by the transfer of energy from the excited donor to the acceptor. In biological applications, this technique has become popular to qualitatively map protein-protein interactions, and in biophysical projects it is used as a quantitative measure for distances between a single donor and acceptor molecule. Numerous approaches can be found in the literature to quantify and map FRET, but the measures they provide are often difficult to interpret. We propose here a quantitative comparison of these methods by using a surface FRET system with controlled amounts of donor and acceptor fluorophores and controlled distances between them. We support the system with a Monte Carlo simulation of FRET, which provides reference values for the FRET efficiency under various experimental conditions. We validate a representative set of FRET efficiencies and indices calculated from the different methods with different experimental settings. Finally, we test their sensitivity and draw conclusions for the preparation of FRET experiments in more complex and less-controlled systems.

  18. Perceptual expertise in forensic facial image comparison

    PubMed Central

    White, David; Phillips, P. Jonathon; Hahn, Carina A.; Hill, Matthew; O'Toole, Alice J.

    2015-01-01

    Forensic facial identification examiners are required to match the identity of faces in images that vary substantially, owing to changes in viewing conditions and in a person's appearance. These identifications affect the course and outcome of criminal investigations and convictions. Despite calls for research on sources of human error in forensic examination, existing scientific knowledge of face matching accuracy is based, almost exclusively, on people without formal training. Here, we administered three challenging face matching tests to a group of forensic examiners with many years' experience of comparing face images for law enforcement and government agencies. Examiners outperformed untrained participants and computer algorithms, thereby providing the first evidence that these examiners are experts at this task. Notably, computationally fusing responses of multiple experts produced near-perfect performance. Results also revealed qualitative differences between expert and non-expert performance. First, examiners' superiority was greatest at longer exposure durations, suggestive of more entailed comparison in forensic examiners. Second, experts were less impaired by image inversion than non-expert students, contrasting with face memory studies that show larger face inversion effects in high performers. We conclude that expertise in matching identity across unfamiliar face images is supported by processes that differ qualitatively from those supporting memory for individual faces. PMID:26336174

  19. Perceptual expertise in forensic facial image comparison.

    PubMed

    White, David; Phillips, P Jonathon; Hahn, Carina A; Hill, Matthew; O'Toole, Alice J

    2015-09-07

    Forensic facial identification examiners are required to match the identity of faces in images that vary substantially, owing to changes in viewing conditions and in a person's appearance. These identifications affect the course and outcome of criminal investigations and convictions. Despite calls for research on sources of human error in forensic examination, existing scientific knowledge of face matching accuracy is based, almost exclusively, on people without formal training. Here, we administered three challenging face matching tests to a group of forensic examiners with many years' experience of comparing face images for law enforcement and government agencies. Examiners outperformed untrained participants and computer algorithms, thereby providing the first evidence that these examiners are experts at this task. Notably, computationally fusing responses of multiple experts produced near-perfect performance. Results also revealed qualitative differences between expert and non-expert performance. First, examiners' superiority was greatest at longer exposure durations, suggestive of more entailed comparison in forensic examiners. Second, experts were less impaired by image inversion than non-expert students, contrasting with face memory studies that show larger face inversion effects in high performers. We conclude that expertise in matching identity across unfamiliar face images is supported by processes that differ qualitatively from those supporting memory for individual faces.

  20. Comparison of surface and satellite gravity data

    NASA Technical Reports Server (NTRS)

    Rapp, R. H.

    1978-01-01

    Satellite derived potential coefficients (GEM 9) are compared to terrestrial gravity data by degree in terms of coefficient differences and in terms of mean anomaly differences. The root mean square undulation difference (to degree 20) was 9 + or - m and the anomaly difference was + or - 7 mgals with GEM 9 commission errors of + or - 1.7 m and + or - 3.8 mgals. The standard deviations of the GEM 9 implied undulations increased from + or - 4 cm at degree 2 to + or - 53 cm at degree 20. The corresponding values implied by a recent (June 1978) terrestrial 5 deg field were + or - 2.53 m and + or - 0.38 m (at degree 20). Comparisons between Geos-3 altimeter derived anomalies and 1 deg X 1 Deg terrestrial data showed that + or - 6-8 mgals is a reasonable accuracy estimate for the altimeter derived anomalies. Anomalies derived from satellite to satellite tracking data indicate an accuracy of about + or - 6 mgals for the recovery of 5 deg equal area blocks.

  1. Comparisons of Prevention Programs for Homeless Youth

    PubMed Central

    Rotheram-Borus, Mary Jane

    2014-01-01

    There are six HIV prevention programs for homeless youth whose efficacy has been or is currently being evaluated: STRIVE, the Community Reinforcement Approach, Strengths-Based Case Management, Ecologically-Based Family Therapy, Street Smart, and AESOP (street outreach access to resources). Programs vary in their underlying framework and theoretical models for understanding homelessness. All programs presume that the youths’ families lack the ability to support their adolescent child. Some programs deemphasize family involvement while others focus on rebuilding connections among family members. The programs either normalize current family conflicts or, alternatively, provide education about the importance of parental monitoring. All programs aim to reduce HIV-related sexual and drug use acts. A coping skills approach is common across programs: Problem-solving skills are specifically addressed in four of the six programs; alternatively, parents in other programs are encouraged to contingently reward their children. Each program also engineers ongoing social support for the families and the youth, either by providing access to needed resources or by substituting a new, supportive relationship for the existing family caretaker. All of the interventions provide access to health and mental health services as basic program resources. A comparison of HIV prevention programs for homeless youth identifies the robust components of each and suggests which programs providers may choose to replicate. PMID:19067164

  2. Spirit on 'Husband Hill,' with 2004 Comparison

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Two Earth years ago, NASA's Mars Exploration Rover Spirit touched down in Gusev Crater. The rover marked its first Mars-year (687 Earth days) anniversary in November 2005. On Nov. 2, 2005, shortly before Spirit's Martian anniversary, the Mars Orbiter Camera on NASA's Mars Global Surveyor acquired an image centered on the rover's location in the 'Columbia Hills.' The location of Spirit on that date is circled on the image on the right. On the left, for comparison, is an image from Jan. 10, 2004, when few dreamed that the Spirit would ever reach the hills from its landing site about three kilometers (two miles) away.

    The newer image has a resolution of about 50 centimeters (1.6 feet) per pixel. North is up; illumination is from the left. The location is near 14.8 degrees south latitude, 184.6 degrees west longitude. Dr. Timothy J. Parker of the Mars Exploration Rover team at NASA's Jet Propulsion Laboratory, Pasadena, Calif., confirmed the location of the rover in the 2005 image. The scale bar is 50 meters (164 feet).

  3. Comparison of Aircraft Icing Growth Assessment Software

    NASA Technical Reports Server (NTRS)

    Wright, William; Potapczuk, Mark G.; Levinson, Laurie H.

    2011-01-01

    A research project is underway to produce computer software that can accurately predict ice growth under any meteorological conditions for any aircraft surface. An extensive comparison of the results in a quantifiable manner against the database of ice shapes that have been generated in the NASA Glenn Icing Research Tunnel (IRT) has been performed, including additional data taken to extend the database in the Super-cooled Large Drop (SLD) regime. The project shows the differences in ice shape between LEWICE 3.2.2, GlennICE, and experimental data. The project addresses the validation of the software against a recent set of ice-shape data in the SLD regime. This validation effort mirrors a similar effort undertaken for previous validations of LEWICE. Those reports quantified the ice accretion prediction capabilities of the LEWICE software. Several ice geometry features were proposed for comparing ice shapes in a quantitative manner. The resulting analysis showed that LEWICE compared well to the available experimental data.

  4. Recent atomic clock comparisons at NIST

    NASA Astrophysics Data System (ADS)

    Lorini, L.; Ashby, N.; Brusch, A.; Diddams, S.; Drullinger, R.; Eason, E.; Fortier, T.; Hastings, P.; Heavner, T.; Hume, D.; Itano, W.; Jefferts, S.; Newbury, N.; Parker, T.; Rosenband, T.; Stalnaker, J.; Swann, W.; Wineland, D.; Bergquist, J.

    2008-10-01

    The record of atomic clock frequency comparisons at NIST over the past half-decade provides one of the tightest constraints of any present-day temporal variations of the fundamental constants. Notably, the 6-year record of increasingly precise measurements of the absolute frequency of the Hg+ single-ion optical clock (using the cesium primary frequency standard NIST-F1) constrains the temporal variation of the fine structure constant α to less than 2 · 10-6yr-1 and offers a Local Position Invariance test in the framework of General Relativity. The most recent measurement of the frequency ratio of the Al+ and Hg+ optical clocks is reported with a fractional frequency uncertainty of ±5.2 · 10-17. The record of such measurements over the last year sensitively tests for a temporal variation of α and constrains dot{α}/α = (-1.6 ± 2.3) . 10^{-17} yr^{-1}, consistent with zero.

  5. Comparison of bioseparation methods for microgravity experiments

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R.; Cohly, Hari H. P.; Rodkey, L. Scott; Barlow, Grant H.; Hymer, Wesley C.

    1988-01-01

    The efficiency of the 1-g version of the continuous-flow electrophoresis (CFE) system flown on Space Shuttle missions is compared with the efficiency of a commercial CFE for separating living cells (human kidney, liver, and pituitary-gland cells and T-lymphocytes). In addition, the CFE system and a reciprocal isoelectric focusing (RIEF) system are compared with respect to protein pyrification efficiency. Correlations were made among electrophoretic mobilities (EPMs), secretory functions of cells, and input sample concentrations. A significant reduction in mean and range EPM was observed when input sample concentrations exceeded a low threshohold. This effect was not observed in microgravity experiments conducted at sample concentrations three times greater than the threshold for the controls. Comparison of CFE and RIEF methods showed that there are apparent advantages for each method depending on the product. For example, RIEF purification of urokinase removed more protein impurities, but focused the enzyme at a pH different than the enzyme's known isoelectric point.

  6. Protein sequence comparison and protein evolution

    SciTech Connect

    Pearson, W.R.

    1995-12-31

    This tutorial was one of eight tutorials selected to be presented at the Third International Conference on Intelligent Systems for Molecular Biology which was held in the United Kingdom from July 16 to 19, 1995. This tutorial examines how the information conserved during the evolution of a protein molecule can be used to infer reliably homology, and thus a shared proteinfold and possibly a shared active site or function. The authors start by reviewing a geological/evolutionary time scale. Next they look at the evolution of several protein families. During the tutorial, these families will be used to demonstrate that homologous protein ancestry can be inferred with confidence. They also examine different modes of protein evolution and consider some hypotheses that have been presented to explain the very earliest events in protein evolution. The next part of the tutorial will examine the technical aspects of protein sequence comparison. Both optimal and heuristic algorithms and their associated parameters that are used to characterize protein sequence similarities are discussed. Perhaps more importantly, they survey the statistics of local similarity scores, and how these statistics can both be used to improve the selectivity of a search and to evaluate the significance of a match. They them examine distantly related members of three protein families, the serine proteases, the glutathione transferases, and the G-protein-coupled receptors (GCRs). Finally, the discuss how sequence similarity can be used to examine internal repeated or mosaic structures in proteins.

  7. Comparisons of some large scientific computers

    NASA Technical Reports Server (NTRS)

    Credeur, K. R.

    1981-01-01

    In 1975, the National Aeronautics and Space Administration (NASA) began studies to assess the technical and economic feasibility of developing a computer having sustained computational speed of one billion floating point operations per second and a working memory of at least 240 million words. Such a powerful computer would allow computational aerodynamics to play a major role in aeronautical design and advanced fluid dynamics research. Based on favorable results from these studies, NASA proceeded with developmental plans. The computer was named the Numerical Aerodynamic Simulator (NAS). To help insure that the estimated cost, schedule, and technical scope were realistic, a brief study was made of past large scientific computers. Large discrepancies between inception and operation in scope, cost, or schedule were studied so that they could be minimized with NASA's proposed new compter. The main computers studied were the ILLIAC IV, STAR 100, Parallel Element Processor Ensemble (PEPE), and Shuttle Mission Simulator (SMS) computer. Comparison data on memory and speed were also obtained on the IBM 650, 704, 7090, 360-50, 360-67, 360-91, and 370-195; the CDC 6400, 6600, 7600, CYBER 203, and CYBER 205; CRAY 1; and the Advanced Scientific Computer (ASC). A few lessons learned conclude the report.

  8. KEY COMPARISON: Key comparison CCQM-K60: Total selenium and selenomethionine in selenised wheat flour

    NASA Astrophysics Data System (ADS)

    Goenaga Infante, Heidi; Sargent, Mike

    2010-01-01

    Key comparison CCQM-K60 was performed to assess the analytical capabilities of national metrology institutes (NMIs) to accurately quantitate the mass fraction of selenomethionine (SeMet) and total selenium (at low mg kg-1 levels) in selenised wheat flour. It was organized by the Inorganic Analysis Working Group (IAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) as a follow-up key comparison to the previous pilot study CCQM-P86 on selenised yeast tablets. LGC Limited (Teddington, UK) and the Institute for National Measurement Standards, National Research Council Canada (NRCC, Ottawa, Canada) acted as the coordinating laboratories. CCQM-K60 was organized in parallel with a pilot study (CCQM-P86.1) involving not only NMIs but also expert laboratories worldwide, thus enabling them to assess their capabilities, discover problems and learn how to modify analytical procedures accordingly. Nine results for total Se and four results for SeMet were reported by the participant NMIs. Methods used for sample preparation were microwave assisted acid digestion for total Se and multiple-step enzymatic hydrolysis and hydrolysis with methanesulfonic acid for SeMet. For total Se, detection techniques included inductively coupled plasma mass spectrometry (ICP-MS) with external calibration, standard additions or isotope dilution analysis (IDMS); instrumental neutron activation analysis (INAA); and graphite furnace atomic absorption spectrometry (GFAAS) with external calibration. For determination of SeMet in the wheat flour sample, the four NMIs relied upon measurements using species-specific IDMS (using 76Se-enriched SeMet) with HPLC-ICP-MS. Eight of the nine participating NMIs reported results for total Se within 3.5% deviation from the key comparison reference value (KCRV). For SeMet, the four participating NMIs reported results within 3.2% deviation from the KCRV. This shows that the performance of the majority of the CCQM-K60 participants was very good

  9. Quantum private comparison with a malicious third party

    NASA Astrophysics Data System (ADS)

    Sun, Zhiwei; Yu, Jianping; Wang, Ping; Xu, Lingling; Wu, Chunhui

    2015-06-01

    In this paper, we will show that quantum private comparison protocol is secure when a malicious third party is presented. The security of the protocol is considered in a cheat-sensitive model, in which the TP is kept honest by the possibility of being caught cheating. Besides, we enhance the privacy of the quantum private comparison protocol, where the participants' inputs and the comparison result can be preserved. Furthermore, in contrast to pervious protocols requiring a large amount of quantum resources, such as entanglement and quantum memory, our protocol is based on BB84 protocol, which is more feasible for practical applications. Finally, we analyze the security of the presented protocol.

  10. A comparison of several GPS data reduction methods

    NASA Technical Reports Server (NTRS)

    Chadsey, H.

    1994-01-01

    For several years, discussions have been ongoing about how to analyze GPS time information in order to get the most accurate and precise time comparison between two locations. Many similar studies were done several years ago before the constellation was dominated by Block II satellites. With the Block II satellites and the use of Selective Availability (S/A), time comparisons have lost some precision and accuracy. This paper presents the results of research that was performed to find not only the best of several time comparison methods, but also to determine to what degree precision and accuracy have declined due to S/A.

  11. Direct Comparison of GPS and VLBI Velocity Estimates

    NASA Technical Reports Server (NTRS)

    Heflin, Michael

    1995-01-01

    Considerable effort has been made to collocate permanent GPS and VLBI sites for comparison. The global GPS solution is derived from daily measurements spanning four years while the VLBI solution is based on monthly measurements spanning more than 10 years. Current WRMS agreement of velocities is 3-5 mm/yr for horizontal rates and 6-10 mm/yr for vertical rates. Comparison of velocities is limited by the time span of GPS data. Positions agree at the level of 1-2 cm and their comparison is limited by the quality of the site ties. Best and worst agreement will be discussed along with possible sources of systematic error.

  12. Comparison of sea snake (Hydrophiidae) neurotoxin to cobra (Naja) neurotoxin.

    PubMed

    Komori, Yumiko; Nagamizu, Masaya; Uchiya, Kei-Ichi; Nikai, Toshiaki; Tu, Anthony T

    2009-12-01

    Both sea snakes and cobras have venoms containing postsynaptic neurotoxins. Comparison of the primary structures indicates many similarities, especially the positions of the four disulfide bonds. However, detailed examination reveals differences in several amino acid residues. Amino acid sequences of sea snake neurotoxins were determined, and then compared to cobra neurotoxins by computer modeling. This allowed for easy comparison of the similarities and differences between the two types of postsynaptic neurotoxins. Comparison of computer models for the toxins of sea snakes and cobra will reveal the three dimensional difference of the toxins much clearer than the amino acid sequence alone.

  13. A comparison of current prediction imaging programs

    PubMed Central

    Smith, J. Dempsey; Thomas, Paul M.; Proffit, William R.

    2013-01-01

    To investigate perceived differences in the ability of current software to simulate the actual outcome of orthognathic surgery, we chose 10 difficult test cases with vertical discrepancies and “retreated” them using the actual surgical changes. Five programs—Dentofacial Planner Plus, Dolphin Imaging, Orthoplan, Quick Ceph Image, and Vistadent—were evaluated, by using both the default result and a refined result created with each program’s enhancement tools. Three panels (orthodontists, oral-maxillofacial surgeons, and laypersons) judged the default images and the retouched simulations by ranking the simulations in side-by-side comparisons and by rating each simulation relative to the actual outcome on a 6-point scale. For the default and retouched images, Dentofacial Planner Plus was judged the best default simulation 79% and 59% of the time, respectively, and its default images received the best (lowest) mean score (2.46) on the 6-point scale. It also scored best (2.26) when the retouched images were compared, but the scores for Dolphin Imaging (2.83) and Quick Ceph (3.03) improved. Retouching had little impact on the scores for the other programs. Although the results show differences in simulation ability, selecting a software package depends on many factors. Performance and ease of use, cost, compatibility, and other features such as image and practice management tools are all important considerations. Users concerned with operating system compatibility and practice management integration might want to consider Dolphin Imaging and Quick Ceph, the programs comprising the second tier. PMID:15127020

  14. Biochemical Comparison of Commercial Selenium Yeast Preparations.

    PubMed

    Fagan, Sheena; Owens, Rebecca; Ward, Patrick; Connolly, Cathal; Doyle, Sean; Murphy, Richard

    2015-08-01

    The trace mineral selenium (Se) is an essential element for human and animal nutrition. The addition of Se to the diet through dietary supplements or fortified food/feed is increasingly common owing to the often sub-optimal content of standard diets of many countries. Se supplements commercially available include the inorganic mineral salts such as sodium selenite or selenate, and organic forms such as Se-enriched yeast. Today, Se yeast is produced by several manufacturers and has become the most widely used source of Se for human supplementation and is also widely employed in animal nutrition where approval in all species has been granted by regulatory bodies such as the European Food Safety Authority (EFSA). Characterisation and comparison of Se-enriched yeast products has traditionally been made by quantifying total selenomethionine (SeMet) content. A disadvantage of this approach, however, is that it does not consider the effects of Se deposition on subsequent digestive availability. In this study, an assessment was made of the water-soluble extracts of commercially available Se-enriched yeast samples for free, peptide-bound and total water-soluble SeMet. Using LC-MS/MS, a total of 62 Se-containing proteins were identified across four Se yeast products, displaying quantitative/qualitative changes in abundance relative to the certified reference material, SELM-1 (P value <0.05; fold change ≥2). Overall, the study indicates that significant differences exist between Se yeast products in terms of SeMet content, Se-containing protein abundance and associated metabolic pathways.

  15. Comparison of several methods for BAP measurement.

    PubMed

    Nakajima, J; Murata, Y; Sakamoto, M

    2006-01-01

    It has been more important for management of water quality to estimate the amount of bioavailable phosphorus (BAP) in suspended solids (SS) entering lakes and estuaries. AGP test or extraction by 0.1 mol l(-1) NaOH (C-BOD) is widely used. Recently, highly bioavailable phosphorus (HBAP) was introduced to indicate a more easily soluble and bioavailable fraction using successive extraction by 0.1 mol l(-1) HCl and 0.1 mol l(-1) NaOH. New biologically measured BAP (B-BAP) using bacterial respiration activity was introduced in this paper. B-BAP was estimated from oxygen uptake rate (OUR), which was measured by a respiratory meter for BOD measurement using a pressure sensor. B-BAP is useful for a rapid and direct measurement of phosphorus bioavailability. B-BAP, HBAP and C-BAP in river SS were measured and compared with each other. The percentages of HBAP and B-BAP to PP were large in the urban river, while the percentage of NaOH-P or C-BAP was large in the rivers flowing in agricultural areas. By comparison with phosphorus fractions in paddy soil and activated sludge it was suggested that SS in the rivers flowing in agricultural areas mainly consisted of clay, silt or sand, while the SS in the urban river consisted of a large percentage of organic particles as well. Phosphorus in SS was suggested to be more easily bioavailable in the urban river than the rivers in agricultural areas. The ratio of C-BAP/B-BAP was large in the rivers in agricultural areas and small in the urban river. As HBAP contents were almost similar to B-BAP contents in the river SS, HBAP can be a suitable index of phosphorus indicating easily and rapidly the bioavailable fraction in SS.

  16. Comparison of Methods of Height Anomaly Computation

    NASA Astrophysics Data System (ADS)

    Mazurova, E.; Lapshin, A.; Menshova, A.

    2012-04-01

    As of today, accurate determination of height anomaly is one of the most difficult problems of geodesy, even with sustainable perfection of mathematical methods, computer possibilities. The most effective methods of height anomaly computation are based on the methods of discrete linear transformations, such as the Fast Fourier Transform (FFT), Short-Time Fourier Transform (STFT), Fast Wavelet Transform (FWT). The main drawback of the classical FFT is weak localization in the time domain. If it is necessary to define the time interval of a frequency presence the STFT is used that allows one to detect the presence of any frequency signal and the interval of its presence. It expands the possibilities of the method in comparison with the classical Fourier Transform. However, subject to Heisenberg's uncertainty principle, it is impossible to tell precisely what frequency signal is present at a given moment of time (it is possible to speak only about the range of frequencies); and it is impossible to tell at what precisely moment of time the frequency signal is present (it is possible to speak only about a time span). A wavelet-transform gives the chance to reduce the influence of the Heisenberg's uncertainty principle on the obtained time-and-frequency representation of the signal. With its help low frequencies have more detailed representation relative to the time, and high frequencies - relative to the frequency. The paper summarizes the results of height anomaly calculations done by the FFT, STFT, FWT methods and represents 3-D models of calculation results. Key words: Fast Fourier Transform(FFT), Short-Time Fourier Transform (STFT), Fast Wavelet Transform(FWT), Heisenberg's uncertainty principle.

  17. Comparison of Electrophysiological Auditory Measures in Fishes.

    PubMed

    Maruska, Karen P; Sisneros, Joseph A

    2016-01-01

    Sounds provide fishes with important information used to mediate behaviors such as predator avoidance, prey detection, and social communication. How we measure auditory capabilities in fishes, therefore, has crucial implications for interpreting how individual species use acoustic information in their natural habitat. Recent analyses have highlighted differences between behavioral and electrophysiologically determined hearing thresholds, but less is known about how physiological measures at different auditory processing levels compare within a single species. Here we provide one of the first comparisons of auditory threshold curves determined by different recording methods in a single fish species, the soniferous Hawaiian sergeant fish Abudefduf abdominalis, and review past studies on representative fish species with tuning curves determined by different methods. The Hawaiian sergeant is a colonial benthic-spawning damselfish (Pomacentridae) that produces low-frequency, low-intensity sounds associated with reproductive and agonistic behaviors. We compared saccular potentials, auditory evoked potentials (AEP), and single neuron recordings from acoustic nuclei of the hindbrain and midbrain torus semicircularis. We found that hearing thresholds were lowest at low frequencies (~75-300 Hz) for all methods, which matches the spectral components of sounds produced by this species. However, thresholds at best frequency determined via single cell recordings were ~15-25 dB lower than those measured by AEP and saccular potential techniques. While none of these physiological techniques gives us a true measure of the auditory "perceptual" abilities of a naturally behaving fish, this study highlights that different methodologies can reveal similar detectable range of frequencies for a given species, but absolute hearing sensitivity may vary considerably.

  18. Report of the key comparison APMP.QM-K19. APMP comparison on pH measurement of borate buffer

    NASA Astrophysics Data System (ADS)

    Hioki, Akiharu; Asakai, Toshiaki; Maksimov, Igor; Suzuki, Toshihiro; Miura, Tsutomu; Obromsook, Krairerk; Tangpaisarnkul, Nongluck; Rodruangthum, Patumporn; Wong, Siu-Kay; Lam, Wai-Hing; Zakaria, Osman; Anuar Mohd. Amin, Khirul; Thanh, Ngo Huy; Máriássy, Michal; Vyskocil, Leos; Hankova, Zuzana; Fisicaro, Paola; Stoica, Daniela; Singh, Nahar; Soni, Daya; Ticona Canaza, Galia; Kutovoy, Viatcheslav; Barbieri Gonzaga, Fabiano; Dias, Júlio Cesar; Vospelova, Alena; Bakovets, Nickolay; Zhanasbayeva, Bibinur

    2015-01-01

    The APMP.QM-K19 was organised by TCQM of APMP to test the abilities of the national metrology institutes in the APMP region to measure a pH value of a borate buffer. This APMP comparison on pH measurement was proposed by the National Metrology Institute of Japan (NMIJ) and the National Institute of Metrology (Thailand) (NIMT) at the APMP-TCQM meeting held 26-27 November 2012. After approval by TCQM, the comparison has been conducted by NMIJ and NIMT. The comparison is a key comparison following CCQM-K19 and CCQM-K19.1. The comparison material was a borate buffer of pH around 9.2 and the measurement temperatures were 15 °C, 25 °C and 37 °C. This is the second APMP key comparison on pH measurement and the fourth APMP comparison on pH measurement following APMP.QM-P06 (two phosphate buffers) in 2004, APMP.QM-P09 (a phthalate buffer) in 2006 and APMP.QM-K9/APMP.QM-P16 (a phosphate buffer) in 2010-2011. The results can be used further by any participant to support its CMC claim at least for a borate buffer. That claim will concern the pH method employed by the participant during this comparison and will cover the used temperature(s) or the full temperature range between 15°C and 37 °C for the participant which measured pH values at the three temperatures. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  19. COMPARISON OF METHODS FOR MEASURING CONCENTRATIONS OF SEMIVOLATILE PARTICULATE MATTER

    EPA Science Inventory

    The paper gives results of a comparison of methods for measuring concentrations of semivolatile particulate matter (PM) from indoor-environment, small, combustion sources. Particle concentration measurements were compared for methods using filters and a small electrostatic precip...

  20. Role and Evaluation of Interlaboratory Comparison Results in Laboratory Accreditation

    NASA Astrophysics Data System (ADS)

    Bode, P.

    2008-08-01

    Participation in interlaboratory comparisons provides laboratories an opportunity for independent assessment of their analytical performance, both in absolute way and in comparison with those by other techniques. However, such comparisons are hindered by differences in the way laboratories participate, e.g. at best measurement capability or under routine conditions. Neutron activation analysis laboratories, determining total mass fractions, often see themselves classified as `outliers' since the majority of other participants employ techniques with incomplete digestion methods. These considerations are discussed in relation to the way results from interlaboratory comparisons are evaluated by accreditation bodies following the requirements of Clause 5.9.1 of the ISO/IEC 17025:2005. The discussion and conclusions come largely forth from experiences in the author's own laboratory.

  1. A Simple Illustration for the Need of Multiple Comparison Procedures

    ERIC Educational Resources Information Center

    Carter, Rickey E.

    2010-01-01

    Statistical adjustments to accommodate multiple comparisons are routinely covered in introductory statistical courses. The fundamental rationale for such adjustments, however, may not be readily understood. This article presents a simple illustration to help remedy this.

  2. A Comparison of Distance Education Competencies Delivered Synchronously and Asynchronously.

    ERIC Educational Resources Information Center

    Dooley, Kim E.; Lindner, James R.; Richards, Lance J.

    2003-01-01

    Comparison of agriculture courses delivered synchronously via interactive television (20 students) and asynchronously via the Web (22 students) showed similar achievement of core distance education competencies: adult learning, technology knowledge, instructional design, communication skills, graphic design, administration) regardless of delivery…

  3. Clinical Comparison of Haloperidol with Chlorpromazine in Mentally Retarded Children

    ERIC Educational Resources Information Center

    LeVann, Leonard J.

    1971-01-01

    In an 8-week double-blind comparison, haloperidol reduced the severity of the target symptoms impulsiveness, hostility, and aggressiveness in significantly more mentally retarded children than did chlorpromazine. (Author)

  4. Comparison of Accreditation Criteria: CBHDP, NLN, and COA Accreditation Criteria.

    ERIC Educational Resources Information Center

    Frels, Lois; Horton, Betty

    1991-01-01

    Presents a detailed comparison of similarities and differences in the accreditation criteria of two nursing accrediting agencies--the National League for Nursing and the Council on Accreditation--as they relate to nurse anesthesiology programs. (JOW)

  5. Table of Comparison of 2012 CDR v 2006 IUR Definitions

    EPA Pesticide Factsheets

    In forming 40 CFR 711, EPA sought to simplify the definition section and remove unnecessary duplication of regulatory terms. This table is a comparison of 2006 IUR Definitions and 2012 CDR Definitions.

  6. Validation Opening Remarks and AIRS-AMST-E Comparisons

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.

    2005-01-01

    Opening remarks to the authors who presented their AIRS validation papers to Journal of Geophysical Research is presented. A general overview of AIRS-AMST-E total water vapor comparisons is also presented.

  7. Comparison Campaign of VLBI Data Analysis Software - First Results

    NASA Technical Reports Server (NTRS)

    Plank, Lucia; Bohm, Johannes; Schuh, Harald

    2010-01-01

    During the development of the Vienna VLBI Software VieVS at the Institute of Geodesy and Geophysics at Vienna University of Technology, a special comparison setup was developed with the goal of easily finding links between deviations of results achieved with different software packages and certain parameters of the observation. The object of comparison is the computed time delay, a value calculated for each observation including all relevant models and corrections that need to be applied in geodetic VLBI analysis. Besides investigating the effects of the various models on the total delay, results of comparisons between VieVS and Occam 6.1 are shown. Using the same methods, a Comparison Campaign of VLBI data analysis software called DeDeCC is about to be launched within the IVS soon.

  8. How Judgments Change Following Comparison of Current and Prior Information.

    PubMed

    Albarracin, Dolores; Wallace, Harry M; Hart, William; Brown, Rick D

    2012-01-01

    Although much observed judgment change is superficial and occurs without considering prior information, other forms of change also occur. Comparison between prior and new information about an issue may trigger change by influencing either or both the perceived strength and direction of the new information. In four experiments, participants formed and reported initial judgments of a policy based on favorable written information about it. Later, these participants read a second passage containing strong favorable or unfavorable information on the policy. Compared to control conditions, subtle and direct prompts to compare the initial and new information led to more judgment change in the direction of a second passage perceived to be strong. Mediation analyses indicated that comparison yielded greater perceived strength of the second passage, which in turn correlated positively with judgment change. Moreover, self-reports of comparison mediated the judgment change resulting from comparison prompts.

  9. How Judgments Change Following Comparison of Current and Prior Information

    PubMed Central

    Albarracin, Dolores; Wallace, Harry M.; Hart, William; Brown, Rick D.

    2013-01-01

    Although much observed judgment change is superficial and occurs without considering prior information, other forms of change also occur. Comparison between prior and new information about an issue may trigger change by influencing either or both the perceived strength and direction of the new information. In four experiments, participants formed and reported initial judgments of a policy based on favorable written information about it. Later, these participants read a second passage containing strong favorable or unfavorable information on the policy. Compared to control conditions, subtle and direct prompts to compare the initial and new information led to more judgment change in the direction of a second passage perceived to be strong. Mediation analyses indicated that comparison yielded greater perceived strength of the second passage, which in turn correlated positively with judgment change. Moreover, self-reports of comparison mediated the judgment change resulting from comparison prompts. PMID:23599557

  10. CCM key comparison CCM.D-K4 'Hydrometer'

    NASA Astrophysics Data System (ADS)

    Lorefice, S.; Becerra, L. O.; Lenard, E.; Lee, Y. J.; Lee, W. G.; Madec, T.; Meury, P. A.; Caceres, J.; Santos, C.; Vamossy, C.; Man, J.; Fen, K.; Toda, K.; Wright, J.; Bettin, H.; Toth, H.

    2016-01-01

    This report presents the comparison philosophy, methodology, analysis and the results of the designed CCM.D-K4 key comparison that covered the calibration of high resolution hydrometers for liquid and alcoholometers in the density range 600 kg/m3 to 2000 kg/m3 at the temperature of 20°C. The main purpose of this comparison was not only to evaluate the degree of equivalence in the calibration of high accuracy hydrometers between NMI participants, but also to link, were it is possible, the results of previous comparisons to Key Comparison Reference Values (KCRVs) of CCM.D-K4. Eleven NMI laboratories took part in the CCM.D-K4 divided in two groups (petals). With the CCM.D-K4 purpose, two similar sets consisting of three hydrometers for liquid density determinations and an alcoholometer were circulated to the NMI participants as a travelling standard in the time interval from January 2011 to April 2012. Twelve Key Comparison Reference Values (KCRVs) for each petal have been obtained at the density values related to the tested density marks of the transfer standards by the results of participants. The KCRVs and corresponding uncertainties were calculated by the weighted mean in the case of consistent results, otherwise the median was used. The degree of equivalence (DoE) with respect to the corresponding KCRV was determined for each participant and, in this particular comparison, the Weighted Least Squares (WLS) method was used to link the individual DoE of each participant by a continuous function. Significant drift of the transfer standards was not detected. This report also gives instructions on calculating pair-wise degrees of equivalence, with the addition of any information on correlations that may be necessary to estimate more accurately as well as the procedure for linking international comparisons to the CCM.D-K4. Finally an example of linkage to the CCM.D-K4 is given by dealing with the results of the bilateral comparison between INRiM and NMIA, which was

  11. Radioxenon standards used in laboratory inter-comparisons.

    PubMed

    Gohla, H; Auer, M; Cassette, Ph; Hague, R K; Lechermann, M; Nadalut, B

    2016-03-01

    Preparation methods for (133)Xe standards of activity concentration and the results of the 2014 (133)Xe laboratory inter-comparison exercise are described. One element of the quality assurance/quality control (QA/QC) program for laboratories of the International Monitoring System (IMS) will be regular inter-comparison exercises. However, until recently, no activity concentration standards for benchmarking were available. Therefore, two (133)Xe activity concentration reference standards were produced independently by Idaho National Laboratory and Seibersdorf Laboratories and used for the 2014 laboratory inter-comparison exercise. The preparation of a complementary (127)Xe activity concentration standard as well as a (127)Xe laboratory inter-comparison exercise suggests (127)Xe as a suitable isotope for QA/QC of remote IMS noble gas stations.

  12. Genuine and drug-induced synesthesia: a comparison.

    PubMed

    Sinke, Christopher; Halpern, John H; Zedler, Markus; Neufeld, Janina; Emrich, Hinderk M; Passie, Torsten

    2012-09-01

    Despite some principal similarities, there is no systematic comparison between the different types of synesthesia (genuine, acquired and drug-induced). This comprehensive review compares the three principal types of synesthesia and focuses on their phenomenological features and their relation to different etiological models. Implications of this comparison for the validity of the different etiological models are discussed. Comparison of the three forms of synesthesia show many more differences than similarities. This is in contrast to their representation in the literature, where they are discussed in many respects as being virtually similar. Noteworthy is the much broader spectrum and intensity with the typical drug-induced synesthesias compared to genuine and acquired synesthesias. A major implication of the phenomenological comparison in regard to the etiological models is that genuine and acquired synesthesias point to morphological substrates, while drug-induced synesthesia appears to be based on functional changes of brain activity.

  13. Comparison theorems for neutral stochastic functional differential equations

    NASA Astrophysics Data System (ADS)

    Bai, Xiaoming; Jiang, Jifa

    2016-05-01

    The comparison theorems under Wu and Freedman's order are proved for neutral stochastic functional differential equations with finite or infinite delay whose drift terms satisfy the quasimonotone condition and diffusion term is the same.

  14. COMPARISON OF ECOLOGICAL COMMUNITIES: THE PROBLEM OF SAMPLE REPRESENTATIVENESS

    EPA Science Inventory

    Obtaining an adequate, representative sample of ecological communities to make taxon richness (TR) or compositional comparisons among sites is a continuing challenge. Sample representativeness literally means the similarity in species composition and relative abundance between a ...

  15. COMPARISON OF BIOLOGICAL COMMUNITIES: THE PROBLEM OF SAMPLE REPRESENTATIVENESS

    EPA Science Inventory

    Obtaining an adequate, representative sample of biological communities or assemblages to make richness or compositional comparisons among sites is a continuing challenge. Traditionally, sample size is based on numbers of replicates or area collected or numbers of individuals enum...

  16. Comparison of marine productivity among Outer Continental Shelf planning areas

    SciTech Connect

    Darnell, R.M.

    1991-04-01

    Continental Shelf Associates was contracted to update and expand an earlier work on a comparison of primary productivity among Outer Continental Shelf (OCS) planning areas. The update consists of four general objectives. This report addresses the fourth objective, the potential to use measures of marine secondary productivity in determining relative rankings of the OCS planning area. Ideally, comparisons of secondary productivity among diverse geographic areas would take an ecosystem perspective. However, there is not enough ecosystem-level understanding to allow a comparison on that basis. The report focuses on individual species and group of species. Zooplankton and benthic communities represent major portions of the marine ecosystems and would be the preferred subjects for comparative studies. At this time comparisons of secondary productivity among planning areas would be difficult with existing databases. It is unlikely this situation will improve in the near future.

  17. Characterization and comparison of emissions from rudimentary waste disposal technologies

    EPA Science Inventory

    Results from 2011 simulation of burn pit emissions and air curtain incinerator emissions, recent developments in methods for open air sampling, comparison of waste energy technologies, current SERDP programs in this area.

  18. Operating Reserves and Wind Power Integration: An International Comparison; Preprint

    SciTech Connect

    Milligan, M.; Donohoo, P.; Lew, D.; Ela, E.; Kirby, B.; Holttinen, H.; Lannoye, E.; Flynn, D.; O'Malley, M.; Miller, N.; Eriksen, P. B.; Gottig, A.; Rawn, B.; Gibescu, M.; Lazaro, E. G.; Robitaille, A.; Kamwa, I.

    2010-10-01

    This paper provides a high-level international comparison of methods and key results from both operating practice and integration analysis, based on an informal International Energy Agency Task 25: Large-scale Wind Integration.

  19. Standard portrait image and image quality assessment: II. Triplet comparison

    NASA Astrophysics Data System (ADS)

    Miyazaki, Keiichi; Kanafusa, Kunihiko; Umemoto, Hiroshi; Takemura, Kazuhiko; Urabe, Hitoshi; Hirai, Keisuke; Ishikawa, Kazuo; Hatada, Toyohiko

    2000-12-01

    We have already proposed a standard portrait for the assessment of preferable skin tone. The present report describes a psycho physical experimental method, i.e., simultaneous triplet comparison that has been developed for the assessment of skin tone by using the portrait and that is characterized not only by a scalability, stability and reproducibility of the resulting scale values, but also by a reduce stress on observers. We have confirmed that the present simultaneous triplet comparison has a degree of scalability and stability almost equivalent to that of paired comparison that is most widely used for similar purposes, and that the stress on observers is about half as much as that of paired comparison.

  20. Comparison of Nutrient Drivers and Response Metrics in Oregon Estuaries

    EPA Science Inventory

    With the goal of assessing sensitivity to nutrient enrichment, we present a cross-estuary comparison of nutrient sources, levels, and biological responses (phytoplankton and macroalgae) for thirteen Oregon estuaries. Nitrogen levels in the upstream portions of the estuaries are ...

  1. A Cross-Sectional Comparison of Army Advertising Attributes

    DTIC Science & Technology

    1990-11-01

    that identifies the needs and characteristics of individuals in the Armys’ prime market , as well as their exposure to Army advertising . One way the Army...U.S. Army Research Institute for the Behavioral and Social Sciences N Research Report 1578 A Cross-Sectional Comparison I of Army Advertising ...62785A 791 2105 H01 11. TITLE (Include Security Classification) A Cross-Sectional Comparison of Army Advertising Attributes 12. PERSONAL AUTHOR(S

  2. Quantum Private Comparison Based on Quantum Search Algorithm

    NASA Astrophysics Data System (ADS)

    Zhang, Wei-Wei; Li, Dan; Song, Ting-Ting; Li, Yan-Bing

    2013-05-01

    We propose two quantum private comparison protocols based on quantum search algorithm with the help of a semi-honest third party. Our protocols utilize the properties of quantum search algorithm, the unitary operations, and the single-particle measurements. The security of our protocols is discussed with respect to both the outsider attack and the participant attack. There is no information leaked about the private information and the comparison result, even the third party cannot know these information.

  3. A quantitative comparison of corrective and perfective maintenance

    NASA Technical Reports Server (NTRS)

    Henry, Joel; Cain, James

    1994-01-01

    This paper presents a quantitative comparison of corrective and perfective software maintenance activities. The comparison utilizes basic data collected throughout the maintenance process. The data collected are extensive and allow the impact of both types of maintenance to be quantitatively evaluated and compared. Basic statistical techniques test relationships between and among process and product data. The results show interesting similarities and important differences in both process and product characteristics.

  4. Comparisons organized by Ionizing Radiation Metrology Laboratory of FTMC, Lithuania.

    PubMed

    Gudelis, A; Gorina, I

    2016-03-01

    The newly established Ionizing Radiation Metrology Laboratory of the National Metrology Institute (FTMC) in Lithuania organized four comparisons in the field of low-level radioactivity measurements in water. For gamma-ray emitters, the activity concentration in the samples was in the range 1-25Bq/kg, while for tritium it was around 2Bq/g. The assigned values of all comparisons were traceable to the primary standards of the Czech Metrology Institute (CMI).

  5. Cylinder expansion test and gas gun experiment comparison

    SciTech Connect

    Harrier, Danielle

    2016-06-30

    This is a summer internship presentation by the Hydro Working Group at Los Alamos National Laboratory (LANL) and goes into detail about their cylinder expansion test and gas gun experiment comparison. Specifically, the gas gun experiment is detailed along with applications, the cylinder expansion test is detailed along with applications, there is a comparison of the methods with pros and cons and limitations listed, the summer project is detailed, and future work is talked about.

  6. A Comparison of Cross-Sector Cyber Security Standards

    SciTech Connect

    Robert P. Evans

    2005-09-01

    This report presents a review and comparison (commonality and differences) of three cross-sector cyber security standards and an internationally recognized information technology standard. The comparison identifies the security areas covered by each standard and reveals where the standards differ in emphasis. By identifying differences in the standards, the user can evaluate which standard best meets their needs. For this report, only cross-sector standards were reviewed.

  7. GODAE Inter-Comparisons in the Tasman and Coral Seas

    DTIC Science & Technology

    2012-08-01

    GODAE inter-comparisons in the Tasman and Coral Seas 11Volume 5 No 2 August 2012 Journal of Operational Oceanography GODAE inter-comparisons in...the Tasman and Coral Seas LEAD AUTHOR’S BIOGRAPHY Peter Oke is a Research Scientist at the Commonwealth Scientific and Industrial Research...compared for the Tasman and Coral Seas , off eastern Australia. Systems considered include those developed in Australia, France, the USA, and the UK

  8. Comparison of Fresh and Aged TNT with Multiwavelength Raman Spectroscopy

    DTIC Science & Technology

    2014-12-04

    Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/6730--14-9572 Comparison of Fresh and Aged TNT with Multiwavelength Raman Spectroscopy...NUMBER OF PAGES 17. LIMITATION OF ABSTRACT Comparison of Fresh and Aged TNT with Multiwavelength Raman Spectroscopy Robert Lunsford, Jacob Grun, and...fresh and aged variants. This is particularly true of UV aging which had the greater effect on the sample of the two aging processes tested

  9. Diagnostic Feature Comparisons for Experimental and Theoretical Gearbox Failures

    DTIC Science & Technology

    2001-04-05

    rotating machinery are S t ....":,C𔃿",ai•" tooth crack /fracture manifested as increases in -,thc t the vibration levels. These vbainlvlca be 16 17 18...borescope images taken during the run. These images, albeit limited in their ability to show tooth crack lengths, will facilitate comparisons between the...area is highlighted in Figure 4 and is labeled "incipient tooth crack ". All comparisons in this paper will focus on this region since the simulations

  10. Neural patterns underlying social comparisons of personal performance

    PubMed Central

    Birg, Robert; Falk, Armin; Weber, Bernd

    2015-01-01

    Humans often evaluate their abilities by comparing their personal performance with that of others. For this process, it is critical whether the comparison turns out in one’s favor or against it. Here, we investigate how social comparisons of performance are encoded and integrated on the neural level. We collected functional magnetic resonance images while subjects answered questions in a knowledge quiz that was related to their profession. After each question, subjects received a feedback about their personal performance, followed by a feedback about the performance of a reference group who had been quizzed beforehand. Based on the subjects’ personal performance, we divided trials in downward and upward comparisons. We found that upward comparisons correlated with activity in the dorsolateral prefrontal cortex and the anterior insula. Downward comparisons were associated with increased activation in the ventral striatum (VS), the medial orbitofrontal cortex and the ventral anterior cingulate cortex (ACC). The extent to which subjects outperformed the reference group modulated the activity in the VS and in the dorsal ACC. We suggest that the co-activation of the VS and the dorsal ACC contributes to the integration of downward comparisons into the evaluation of personal performance. PMID:24948156

  11. Comparison groups on bills: Automated, personalized energy information

    SciTech Connect

    Iyer, Maithili; Kempton, Willett; Payne, Christopher

    2006-07-01

    A program called ``Innovative Billing?? has been developed to provide individualized energy information for a mass audience?the entireresidential customer base of an electric or gas utility. Customers receive a graph on the bill that compares that customer?s consumption with othersimilar customers for the same month. The program aims to stimulate customers to make ef?ciency improvements. To group as many as severalmillion customers into small ``comparison groups??, an automated method must be developed drawing solely from the data available to the utility.This paper develops and applies methods to compare the quality of resulting comparison groups.A data base of 114,000 customers from a utility billing system was used to evaluate Innovative Billing comparison groups, comparing fouralternative criteria: house characteristics (?oor area, housing type, and heating fuel); street; meter read route; billing cycle. Also, customers wereinterviewed to see what forms of comparison graphs made most sense and led to fewest errors of interpretation. We ?nd that good qualitycomparison groups result from using street name, meter book, or multiple house characteristics. Other criteria we tested, such as entire cycle, entiremeter book, or single house characteristics such as ?oor area, resulted in poor quality comparison groups. This analysis provides a basis forchoosing comparison groups based on extensive user testing and statistical analysis. The result is a practical set of guidelines that can be used toimplement realistic, inexpensive innovative billing for the entire customer base of an electric or gas utility.

  12. International comparison CCQM-K76: Sulfur dioxide in nitrogen

    NASA Astrophysics Data System (ADS)

    Guenther, Franklin R.; Kelley, Michael E.; Mitchell, Gerald D.; de Jesús Avila Salas, Manuel; Koelliker Delgado, Jorge; Rangel Murillo, Francisco; Serrano Caballero, Victor M.; Pérez Castorena, Alejandro; Shinji, Uehara; Ciecior, Dariusz; Smarçaro da Cunha, Valnei; Rodrigues Augusto, Cristiane; Cipriano Ribeiro, Claudia; de Lima Fioravante, Andreia; Dias, Florbela; Sang-Hyub, Oh; Macé, Tatiana; Sutour, Christophe; Büki, Tamás; Qiao, Han; Botha, Angelique; Mogale, David M.; Tshilongo, James; Ntsasa, Napo; Mphamo, Tshepiso; Uprichard, Ian; Milton, Martin; Vargha, Gergely; Brookes, Chris; Johri, Prabha; Valkova, Miroslava; Konopelko, Leonid; Kustikov, Yury; Pankratov, V. V.; Rumyantsev, D. V.; Pavlov, M. V.; Gromova, E. V.; van der Veen, Adriaan; van Otterloo, Peter; Wessel, Rob M.

    2011-01-01

    The key comparison CCQM-K76 was designed to test the capabilities of the participants to measure and certify sulfur dioxide in nitrogen, and to provide supporting evidence for the CMCs of these institutes for sulfur dioxide. Also, as sulfur dioxide is designated a core compound, and the 100 µmol/mol concentration is within the designated core compound concentration range, this comparison was also designed to demonstrate core capabilities of institutes which qualify under the rules of the Gas Analysis Working Group. The results of all 16 participants in this key comparison, except for three, are consistent with their key comparisons reference values. The three participants which are outside the KCRV interval are NIM, SMU and NPLI. This comparison may be used to demonstrate core analytical capabilities in accordance with the rules and procedures of the CCQM Gas Analysis Working group. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  13. Hopelessness and social comparison in Turkish adolescent with visual impairment.

    PubMed

    Erol, S; Ergun, A

    2013-04-01

    The purpose of this study was to determine visually impaired adolescents' level of hopelessness and how they perceive of themselves socially compared to other individuals. Another purpose of this study was to look for relationships between hopelessness and social comparison in adolescents with visual impairment. The research population was comprised of 130 students at a secondary school for the visually impaired in Istanbul, Turkey. Our study demonstrated a weak relationship between social comparison and hopelessness (r=-0.46, P < 0.000). The mean hopelessness score for the adolescents with visual impairment was 4.59 ± 3.12 (girls: 4.23 ± 3.10; boys: 4.83 ± 3.11) and social comparison score was 87.50 ± 11.19 (girls: 88.67 ± 11.62; boys: 86.60 ± 10.85). Hopelessness and social comparison were not affected by being blind from birth compared to later or from being a full-time boarding student compared to being a day student. The hopeless (Beck Hopelessness Scale score ≥ 9) adolescents' social comparison scores were found lower than hopeful ones' scores (P < 000). Factors affecting hopelessness and social comparison were feelings about their father, teacher and school.

  14. Changes in latent fingerprint examiners' markup between analysis and comparison.

    PubMed

    Ulery, Bradford T; Hicklin, R Austin; Roberts, Maria Antonia; Buscaglia, JoAnn

    2015-02-01

    After the initial analysis of a latent print, an examiner will sometimes revise the assessment during comparison with an exemplar. Changes between analysis and comparison may indicate that the initial analysis of the latent was inadequate, or that confirmation bias may have affected the comparison. 170 volunteer latent print examiners, each randomly assigned 22 pairs of prints from a pool of 320 total pairs, provided detailed markup documenting their interpretations of the prints and the bases for their comparison conclusions. We describe changes in value assessments and markup of features and clarity. When examiners individualized, they almost always added or deleted minutiae (90.3% of individualizations); every examiner revised at least some markups. For inconclusive and exclusion determinations, changes were less common, and features were added more frequently when the image pair was mated (same source). Even when individualizations were based on eight or fewer corresponding minutiae, in most cases some of those minutiae had been added during comparison. One erroneous individualization was observed: the markup changes were notably extreme, and almost all of the corresponding minutiae had been added during comparison. Latents assessed to be of value for exclusion only (VEO) during analysis were often individualized when compared to a mated exemplar (26%); in our previous work, where examiners were not required to provide markup of features, VEO individualizations were much less common (1.8%).

  15. Intercontinental comparison of caustic ingestion in children

    PubMed Central

    Rafeey, Mandana; Ghojazadeh, Morteza; Mehdizadeh, Amir; Hazrati, Hakimeh

    2015-01-01

    Purpose To investigate the caustic ingestion in children among different continents according to demographic characteristics (core purpose), main symptoms, common caustic agents, signs and symptoms, management, treatment and complications. Methods This systematic review was performed by searching the databases Science Direct, ProQuest, Google Scholar, and PubMed, electronically and manually. We included studies that were published from 1980 to 2013, at University of Medical Sciences of Tabriz, Iran. A strategic search was performed with keywords including caustic, corrosive, ingestion and children, and was limited to articles in English and Persian. Statistical analysis was performed by SPSS ver. 18. Results Of 63 selected articles of caustic ingestion with 9,888 samples, the proportion of Africa was 3 articles (4.8%) and 95 samples (1%), America 9 articles (14.3%) and 305 sample (3%), Asia 29 articles (46%) and 2,780 samples (28.1%), Europe 17 articles (27%) and 3,002 samples (30.4%), and Oceania 5 articles (7.9%) and 3,706 samples (37.5%). The average age was in the Africa 3.07±2.02 years, America 3.17±1.83 years, Asia 3.34±1.58 years, Europe 3.58±2.09 years and Oceania 3.52±2.02 years. Sex distribution was in Africa 76 males (0.91%) and 19 females (0.23%), America 49 males (0.58%) and 41 females (0.49%), Asia 1,575 males (18.76%) and 1,087 females (12.95%), Europe 1,018 males (12.13%) and 823 females (9.8%), and Oceania 1,918 males (22.85%) and 1,788 females (21.3%). Statistical analysis of the data indicated higher consumption in Europe and Oceania in the boys with higher average age of years. Conclusion The comparison of caustic ingestion indicated that the cause substances of caustic ingestion in children are different among continents, therefore prevention strategy and different treatment guidelines among continents will be needed. PMID:26770225

  16. Instrument comparison for Aerosolized Titanium Dioxide

    NASA Astrophysics Data System (ADS)

    Ranpara, Anand

    Recent toxicological studies have shown that the surface area of ultrafine particles (UFP i.e., particles with diameters less than 0.1 micrometer) has a stronger correlation with adverse health effects than does mass of these particles. Ultrafine titanium dioxide (TiO2) particles are widely used in industry, and their use is associated with adverse health outcomes, such as micro vascular dysfunctions and pulmonary damages. The primary aim of this experimental study was to compare a variety of laboratory and industrial hygiene (IH) field study instruments all measuring the same aerosolized TiO2. The study also observed intra-instrument variability between measurements made by two apparently identical devices of the same type of instrument placed side-by-side. The types of instruments studied were (1) DustTrak(TM) DRX, (2) Personal Data RAMs(TM) (PDR), (3) GRIMM, (4) Diffusion charger (DC) and (5) Scanning Mobility Particle Sizer (SMPS). Two devices of each of the four IH field study instrument types were used to measure six levels of mass concentration of fine and ultrafine TiO2 aerosols in controlled chamber tests. Metrics evaluated included real-time mass, active surface area and number/geometric surface area distributions, and off-line gravimetric mass and morphology on filters. DustTrak(TM) DRXs and PDRs were used for mass concentration measurements. DCs were used for active surface area concentration measurements. GRIMMs were used for number concentration measurements. SMPS was used for inter-instrument comparisons of surface area and number concentrations. The results indicated that two apparently identical devices of each DRX and PDR were statistically not different with each other for all the trials of both the sizes of powder (p < 5%). Mean difference between mass concentrations measured by two DustTrak DRX devices was smaller than that measured by two PDR devices. DustTrak DRX measurements were closer to the reference method, gravimetric mass concentration

  17. Worldwide site comparison for submillimetre astronomy

    NASA Astrophysics Data System (ADS)

    Tremblin, P.; Schneider, N.; Minier, V.; Durand, G. Al.; Urban, J.

    2012-12-01

    Aims: The most important limitation for ground-based submillimetre (submm) astronomy is the broad-band absorption of the total water vapour in the atmosphere above an observation site, often expressed as the precipitable water vapour (PWV). A long-term statistic on the PWV is thus mandatory to characterize the quality of an existing or potential site for observational submm-astronomy. In this study we present a three-year statistic (2008-2010) of the PWV for ground-based telescope sites all around the world and for stratospheric altitudes relevant for SOFIA (Stratospheric Observatory for Far-Infrared Astronomy). The submm-transmission is calculated for typical PWVs using an atmospheric model. Methods: We used data from IASI (Infrared Atmospheric Sounding Interferometer) on the Metop-A satellite to retrieve water vapour profiles for each site (11 in total, comprising Antarctica, Chile, Mauna Kea, Greenland, Tibet). The use of a single instrument to make the comparison provides unbiased data with a common calibration method. The profiles are integrated above the mountain/stratospheric altitude to get an estimation of the PWV. We then applied the atmospheric model MOLIERE (Microwave Observation and LIne Estimation and REtrieval) to compute the corresponding atmospheric absorption for wavelengths between 150 μm and 3 mm. Results: We present the absolute PWV values for each site sorted by year and time percentage. The PWV corresponding to the first decile (10%) and the quartiles (25%, 50%, 75%) are calculated and transmission curves between 150 μm and 3 mm for these values are shown. The Antarctic and South-American sites present very good conditions for submillimetre astronomy. The 350 μm and 450 μm atmospheric windows are open all year long, whereas the 200 μm atmospheric window opens reasonably for 25% of the time in Antarctica and the extremely high-altitude sites in Chile. Potential interesting new facilities are Macon in Argentina and Summit in Greenland

  18. Collective violence: comparisons between youths and chimpanzees.

    PubMed

    Wrangham, Richard W; Wilson, Michael L

    2004-12-01

    Patterns of collective violence found among humans include similarities to those seen among chimpanzees. These include participation predominantly by males, an intense personal and group concern with status, variable subgroup composition, defense of group integrity, inter-group fights that include surprise attacks, and a tendency to avoid mass confrontation. Compared to chimpanzee communities, youth gangs tend to be larger, composed of younger individuals, occupying smaller territories and having a more complex organization. Youth gangs also differ from chimpanzee communities as a result of numerous cultural and environmental influences including complex relations with non-gang society. These relations are governed in important ways by such factors as perceived economic and personal constraints, policing, family structure, and levels of poverty, crime, and racism. Nevertheless, the concepts that sociologists use to account for collective violence in youth gangs are somewhat similar to those applied by anthropologists and biologists to chimpanzees. Thus in both cases collective violence is considered to emerge partly because males are highly motivated to gain personal status, which they do by physical violence. In the case of youth gangs, the reasons for the prevalence of physical violence in status competition compared to non-gang society are clearly context-specific, both culturally and historically. By contrast, among chimpanzees the use of physical violence to settle status competition is universal (in the wild and captivity). The use of physical violence in individual status competition therefore has different sources in youth gangs and chimpanzees. Regardless of its origin, however, its combination with an intense concern for status can explain: (1) why individual males form alliances among each other; and hence (2) how such alliances generate social power, closed groups, and a capacity for defense of territory or pre-emptive attacks on rivals. This comparison

  19. A Comparison of High-Voltage Switches

    SciTech Connect

    Chu, K.W.; Scott, G.L.

    1999-02-01

    This report summarizes our work on high-voltage switches during the past few years. With joint funding from the Department of Energy (DOE) and the Department of Defense (DOD), we tested a wide variety of switches to a common standard. This approach permitted meaningful comparisons between disparate switches. Most switches were purchased from commercial sources, though some were experimental devices. For the purposes of this report, we divided the switches into three generic types (gas, vacuum, and semiconductor) and selected data that best illustrates important strengths and weaknesses of each switch type. Test techniques that indicate the state of health of the switches are emphasized. For example, a good indicator of residual gas in a vacuum switch is the systematic variation of the switching delay in response to changes in temperature and/or operating conditions. We believe that the presentation of this kind of information will help engineers to select and to test switches for their particular applications. Our work was limited to switches capable of driving slappers. Also known as exploding-foil initiators, slappers are detonators that initiate a secondary explosive by direct impact with a small piece of matter moving at the detonation velocity (several thousands of meters per second). A slapper is desirable for enhanced safety (no primary explosive), but it also places extra demands on the capacitor-discharge circuit to deliver a fast-rising current pulse (greater than 10 A/ns) of several thousand amperes. The required energy is substantially less than one joule; but this energy is delivered in less than one microsecond, taking the peak power into the megawatt regime. In our study, the switches operated in the 1 kV to 3 kV range and were physically small, roughly 1 cm{sup 3} or less. Although a fuze functions only once in actual use, multiple-shot capability is important for production testing and for research work. For this reason, we restricted this report

  20. Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with ISCIII (December 2014)

    NASA Astrophysics Data System (ADS)

    Viallon, Joële; Moussay, Philippe; Idrees, Faraz; Wielgosz, Robert; Sanchez, Carmen; Morillo Gomez, Pilar

    2015-01-01

    As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of the Instituto de Salud Carlos III (ISCIII) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  1. Bilateral comparison of cryogenic radiometers between NPL and UME, linked to the CCPR-S3 supplementary comparison

    NASA Astrophysics Data System (ADS)

    Goodman, T.

    2016-01-01

    This report presents the results of a bilateral comparison between NPL and UME, which was carried out to establish the unilateral degrees of equivalence for UME with respect to the defined reference value of the CCPR S3 supplementary comparison of cryogenic radiometers using silicon trap detectors as transfer devices. In accordance with the protocol for the CCPR S3 comparison, UME was asked to calibrate a set of NPL supplied silicon trap transfer detectors at a series of laser wavelengths; UME chose to measure at 514.5 nm and 632.8 nm. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  2. Final report, ongoing key comparison BIPM.QM-K1: Ozone at ambient level, comparison with KRISS (March 2012)

    NASA Astrophysics Data System (ADS)

    Viallon, Joële; Moussay, Philippe; Idrees, Faraz; Wielgosz, Robert; Lee, Sangil; Lee, Jae Y.; Woo, Jin C.; Kim, Byung M.

    2012-01-01

    As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of Korea maintained by the Korea Research Institute of Standards and Science (KRISS) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  3. Final report, ongoing key comparison BIPM.QM-K1: Ozone at ambient level, comparison with EMPA (June 2012)

    NASA Astrophysics Data System (ADS)

    Viallon, Joële; Moussay, Philippe; Idrees, Faraz; Wielgosz, Robert; Zellweger, Christoph

    2012-01-01

    As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone standard of the World Meteorological Organisation maintained by the Swiss Federal Laboratories for Materials Testing and Research (EMPA) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  4. Final report, ongoing key comparison BIPM.QM-K1: Ozone at ambient level, comparison with FMI (February 2012)

    NASA Astrophysics Data System (ADS)

    Viallon, Joële; Moussay, Philippe; Idrees, Faraz; Wielgosz, Robert; Walden, Jari; Kuronen, Pirjo

    2012-01-01

    As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of Finland maintained by the Finnish Meteorological Institute (FMI) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  5. Final report on ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with VNIIM (June 2014)

    NASA Astrophysics Data System (ADS)

    Viallon, Joële; Moussay, Philippe; Idrees, Faraz; Wielgosz, Robert; Konopelko, Leonid; Kustikov, Yuri

    2015-01-01

    As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of the D I Mendeleyev Institute for Metrology (VNIIM) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  6. Final report on ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with NIM (July 2014)

    NASA Astrophysics Data System (ADS)

    Viallon, Joële; Moussay, Philippe; Idrees, Faraz; Wielgosz, Robert; Zhou, Zeyi

    2015-01-01

    As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone standard of China maintained by the National Institute of Metrology (NIM) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  7. Final report, ongoing key comparison BIPM.QM-K1: Ozone at ambient level, comparison with LNE (May 2012)

    NASA Astrophysics Data System (ADS)

    Viallon, Joële; Moussay, Philippe; Idrees, Faraz; Wielgosz, Robert; Macé, Tatiana; Couette, Jérome

    2012-01-01

    As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of France maintained by the Laboratoire National de métrologie et d'Essais (LNE) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  8. Final report, ongoing key comparison BIPM.QM-K1: Ozone at ambient level, comparison with UBA (March 2012)

    NASA Astrophysics Data System (ADS)

    Viallon, Joële; Moussay, Philippe; Idrees, Faraz; Wielgosz, Robert; Stummer, Volker; Schinz, Verena

    2012-01-01

    As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of Germany maintained by the Umweltbundesamt (UBA) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  9. KEY COMPARISON Final report on APMP international comparison APMP.EM-K9: High voltage AC-DC transfer standards

    NASA Astrophysics Data System (ADS)

    Wei, Yih-Cheng; Yeh, Hsin-Da

    2010-01-01

    The international key comparison APMP.EM-K9 of AC-DC high voltage transfer standards with 12 participants was carried out from June 2000 to January 2004. This comparison offers the same range and frequencies as BIPM key comparison CCEM-K9, voltages at 500 V and 1000 V, frequency from 1 kHz to 100 kHz. This comparison provides the national metrology institutes (NMIs) of the APMP member economies with an opportunity to link the values of their standards for AC-DC transfer difference to the international reference values. The results of the majority of the participating NMIs show an agreement with the reference value within the associated expanded uncertainty given by the individual NMI. The agreement of the results and the tables of the degree of equivalence of the participants are included. The results have been linked to the key comparison CCEM-K9. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  10. International comparison CCQM-K101: oxygen in nitrogen—a track B comparison and that the matrix contains argon

    NASA Astrophysics Data System (ADS)

    Zhou, Z.; Han, Q.; Wang, D.; Macé, T.; Kipphardt, H.; Maiwald, M.; Tuma, D.; Uehara, S.; Akima, D.; Shimosaka, T.; Jung, J.; Oh, S.-H.; van der Veen, A.; van Wijk, J. I. T.; Ziel, P. R.; Konopelko, L.; Valkova, M.; Mogale, David M.; Botha, A.; Brewer, P.; Murugan, A.; Doval Minnaro, M.; Miller, M.; Guenther, F.; Kelly, M. E.

    2016-01-01

    This key comparison aims to assess the capabilities of the participants to determine the amount-of-substance fraction oxygen in nitrogen. The GAWG has classified this as a track B comparison, due to the unexpected 50 μmol/mol argon mole fraction content of the transfer standards, which effects the achievable performance of some measurement techniques such a GC-TCD. The separation of oxygen and argon is challenging, and not all systems in use are equally well designed for it. As this analytical challenge due to a substantial fraction of argon in the transfer standards became a reality, the Gas Analysis Working Group (GAWG) decided to qualify this key comparison as a regular key comparison and not as a core comparison, which may be used to support calibration and measurement capabilities (CMCs) for oxygen in nitrogen, or for oxygen in nitrogen mixtures containing argon only (see also the section on support to CMCs). Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  11. PWC - PAIRWISE COMPARISON SOFTWARE: SOFTWARE PROGRAM FOR PAIRWISE COMPARISON TASK FOR PSYCHOMETRIC SCALING AND COGNITIVE RESEARCH

    NASA Technical Reports Server (NTRS)

    Ricks, W. R.

    1994-01-01

    PWC is used for pair-wise comparisons in both psychometric scaling techniques and cognitive research. The cognitive tasks and processes of a human operator of automated systems are now prominent considerations when defining system requirements. Recent developments in cognitive research have emphasized the potential utility of psychometric scaling techniques, such as multidimensional scaling, for representing human knowledge and cognitive processing structures. Such techniques involve collecting measurements of stimulus-relatedness from human observers. When data are analyzed using this scaling approach, an n-dimensional representation of the stimuli is produced. This resulting representation is said to describe the subject's cognitive or perceptual view of the stimuli. PWC applies one of the many techniques commonly used to acquire the data necessary for these types of analyses: pair-wise comparisons. PWC administers the task, collects the data from the test subject, and formats the data for analysis. It therefore addresses many of the limitations of the traditional "pen-and-paper" methods. By automating the data collection process, subjects are prevented from going back to check previous responses, the possibility of erroneous data transfer is eliminated, and the burden of the administration and taking of the test is eased. By using randomization, PWC ensures that subjects see the stimuli pairs presented in random order, and that each subject sees pairs in a different random order. PWC is written in Turbo Pascal v6.0 for IBM PC compatible computers running MS-DOS. The program has also been successfully compiled with Turbo Pascal v7.0. A sample executable is provided. PWC requires 30K of RAM for execution. The standard distribution medium for this program is a 5.25 inch 360K MS-DOS format diskette. Two electronic versions of the documentation are included on the diskette: one in ASCII format and one in MS Word for Windows format. PWC was developed in 1993.

  12. Bilateral comparison of an IPRT between KRISS and SIC

    NASA Astrophysics Data System (ADS)

    Yang, I.; Sánchez, C. A.

    2013-09-01

    As a follow-up of a memorandum of understanding signed in 2009 between KRISS of Korea and SIC of Colombia, the two national metrology institutes carried out a bilateral comparison of calibration of an industrial platinum resistance thermometer (IPRT). A protocol that was similar to that of APMP.T-S6 has been agreed and followed in the comparison. The method of the calibration at each laboratory was calibration by comparison against calibrated reference thermometers. The nominal temperatures of the comparison were nine temperatures, including the ice point, between -50 °C and 500 °C. One commercially-available IPRT with α ˜ 0.00385 °C-1 that was prepared by KRISS was calibrated by comparison firstly at KRISS, and then at SIC, and finally at KRISS to assess the drift of the artifact during the comparison. At KRISS, an ice-point bath, three liquid baths and a salt bath were used to provide isothermal environment for the comparison. At SIC, an ice-point bath, two liquid baths and a vertical furnace with a metal equalizing block were used. The claimed uncertainty with k=2 of the calibration at KRISS, excluding the longterm instability and hysteresis of the traveling IPRT, was 30 mK, and that at SIC was 120 mK. The capability of the calibration of the two laboratories from -50 °C to 500 °C showed a good agreement within the claimed uncertainty of the calibration. The largest deviation of the two calibration results was 75 mK at 500 °C.

  13. Automated UMLS-based comparison of medical forms.

    PubMed

    Dugas, Martin; Fritz, Fleur; Krumm, Rainer; Breil, Bernhard

    2013-01-01

    Medical forms are very heterogeneous: on a European scale there are thousands of data items in several hundred different systems. To enable data exchange for clinical care and research purposes there is a need to develop interoperable documentation systems with harmonized forms for data capture. A prerequisite in this harmonization process is comparison of forms. So far--to our knowledge--an automated method for comparison of medical forms is not available. A form contains a list of data items with corresponding medical concepts. An automatic comparison needs data types, item names and especially item with these unique concept codes from medical terminologies. The scope of the proposed method is a comparison of these items by comparing their concept codes (coded in UMLS). Each data item is represented by item name, concept code and value domain. Two items are called identical, if item name, concept code and value domain are the same. Two items are called matching, if only concept code and value domain are the same. Two items are called similar, if their concept codes are the same, but the value domains are different. Based on these definitions an open-source implementation for automated comparison of medical forms in ODM format with UMLS-based semantic annotations was developed. It is available as package compareODM from http://cran.r-project.org. To evaluate this method, it was applied to a set of 7 real medical forms with 285 data items from a large public ODM repository with forms for different medical purposes (research, quality management, routine care). Comparison results were visualized with grid images and dendrograms. Automated comparison of semantically annotated medical forms is feasible. Dendrograms allow a view on clustered similar forms. The approach is scalable for a large set of real medical forms.

  14. Aerosol Angstrom Absorption Coefficient Comparisons during MILAGRO.

    NASA Astrophysics Data System (ADS)

    Marley, N. A.; Marchany-Rivera, A.; Kelley, K. L.; Mangu, A.; Gaffney, J. S.

    2007-12-01

    Measurements of aerosol absorption were obtained as part of the MAX-Mex component of the MILAGRO field campaign at site T0 (Instituto Mexicano de Petroleo in Mexico City) by using a 7-channel aethalometer (Thermo- Anderson) during the month of March, 2006. The absorption measurements obtained in the field at 370, 470, 520, 590, 660, 880, and 950 nm were used to determine the aerosol Angstrom absorption exponents by linear regression. Since, unlike other absorbing aerosol species (e.g. humic like substances, nitrated PAHs), black carbon absorption is relatively constant from the ultraviolet to the infrared with an Angstrom absorption exponent of -1 (1), a comparison of the Angstrom exponents can indicate the presence of aerosol components with an enhanced UV absorption over that expected from BC content alone. The Angstrom exponents determined from the aerosol absorption measurements obtained in the field varied from - 0.7 to - 1.3 during the study and was generally lower in the afternoon than the morning hours, indicating an increase in secondary aerosol formation and photochemically generated UV absorbing species in the afternoon. Twelve-hour integrated samples of fine atmospheric aerosols (<0.1micron) were also collected at site T0 and T1 (Universidad Technologica de Tecamac, State of Mexico) from 5 am to 5 pm (day) and from 5 pm to 5 am (night) during the month of March 2006. Samples were collected on quartz fiber filters with high volume impactor samplers. Continuous absorption spectra of these aerosol samples have been obtained in the laboratory from 280 to 900nm with the use of an integrating sphere coupled to a UV spectrometer (Beckman DU with a Labsphere accessory). The integrating sphere allows the detector to collect and spatially integrate the total radiant flux reflected from the sample and therefore allows for the measurement of absorption on highly reflective or diffusely scattering samples. These continuous spectra have also been used to obtain the

  15. New York State 2009 NHTS Comparison Report

    SciTech Connect

    Southworth, Frank; Reuscher, Tim; Hwang, Ho-Ling

    2012-06-01

    The U.S. Department of Transportation (USDOT) initiated an effort in 1969 to collect detailed data on personal travel, with the most recent surveys being the 1995 Nationwide Personal Transportation Survey (NPTS) and the 2001 and 2009 National Household Travel Surveys (NHTS). The primary objective of these surveys is to collect trip-based data on the nature and characteristics of personal travel so that the relationships between the characteristics of personal travel and the socio-economic and demographic characteristics of the traveler and his/her household can be established. In addition to the number of sample households that the national NPTS/NHTS survey allotted to New York State, NYDOT procured an additional sample of households in the 1995, 2001, and 2009 surveys. The comparisons drawn in this report compare the results from these NYS sampled households to the results from households drawn for the rest of the nation. Many of the differences between NYC counties and others in the state result from the striking differences in private vehicle ownership levels, with less than one in two NYC drivers and only 64% of NYC households owning a vehicle in 2009: versus 9 out of 10 drivers owning a vehicle, and between 1.5 and 2 vehicles owned per household, on the average, in the state's other metro areas. And this situation has changed very little over the past fourteen years covered by the three latest NPTS/NHTS surveys. While households in metro areas outside NYC do not own a vehicle largely due to income constraints, many households in NYC/Manhattan do not own a vehicle by choice. However, the statistics suggest that the mobility of zero-vehicle households in NYC/Manhattan is by no means deterred by the lack of a vehicle. While the private vehicle tripmaking rate of NYC residents was between one half and one third that in the state's other metro areas, and their daily VMT about half that of other metro areas, most of their daily travel needs were met by walking or by

  16. Current Comparison of Advanced Fuel Cycle Options

    SciTech Connect

    Steven J. Piet; B. W. Dixon; A. Goldmann; R. N. Hill; J. J. Jacobson; G. E. Matthern; J. D. Smith; A. M. Yacout

    2006-03-01

    The nuclear fuel cycle includes mining, enrichment, nuclear power plants, recycling (if done), and residual waste disposition. The U.S. Advanced Fuel Cycle Initiative (AFCI) has four program objectives to guide research on how best to glue these pieces together, as follows: waste management, proliferation resistance, energy recovery, and systematic management/economics/safety. We have developed a comprehensive set of metrics to evaluate fuel cycle options against the four program objectives. The current list of metrics is long-term heat, long-term dose, radiotoxicity and weapons usable material. This paper describes the current metrics and initial results from comparisons made using these metrics. The data presented were developed using a combination of “static” calculations and a system dynamic model, DYMOND. In many cases, we examine the same issue both dynamically and statically to determine the robustness of the observations. All analyses are for the U.S. reactor fleet. This work aims to clarify many of the issues being discussed within the AFCI program, including Inert Matrix Fuel (IMF) versus Mixed Oxide (MOX) fuel, single-pass versus multi-pass recycling, thermal versus fast reactors, and the value of separating cesium and strontium. The results from a series of dynamic simulations evaluating these options are included in this report. The model interface includes a few “control knobs” for flying or piloting the fuel cycle system into the future. The results from the simulations show that the future is dark (uncertain) and that the system is sluggish with slow time response times to changes (i.e., what types of reactors are built, what types of fuels are used, and the capacity of separation and fabrication plants). Piloting responsibilities are distributed among utilities, government, and regulators, compounding the challenge of making the entire system work and respond to changing circumstances. We identify four approaches that would increase our

  17. Going back to Donald: how comparisons shape judgmental priming effects.

    PubMed

    Mussweiler, Thomas; Damisch, Lysann

    2008-12-01

    The authors examine how judgmental priming effects are shaped by comparisons. Specifically, they suggest that concept priming involves spontaneous activation of concept-consistent standards, which are then spontaneously compared to the judgmental target. In 6 studies, they used a variety of priming methods (contextual cue, subliminal priming, indirect priming) to test these notions of spontaneous standard activation and spontaneous comparison. Study 1 demonstrates that priming a trait concept activates concept-consistent standards. Study 2 suggests that these activated standards contribute to priming effects. If alternative standards that are not particularly consistent with the primed concept are activated, priming effects diminish. Studies 3-6 show that the magnitude and direction of priming effects depend on the intensity and the type of the engaged comparison. Specifically, Study 3 demonstrates that the magnitude of a priming effect depends on the intensity of comparative processing. Studies 4 through 6 show that the direction of a priming effect (assimilation vs. contrast) depends on whether judges engage in a similarity or dissimilarity testing comparison mechanism--a factor which has been found to shape comparison consequences in other domains. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

  18. COMPARISON FRICTION: EXPERIMENTAL EVIDENCE FROM MEDICARE DRUG PLANS*

    PubMed Central

    Kling, Jeffrey R.; Mullainathan, Sendhil; Shafir, Eldar; Vermeulen, Lee; Wrobel, Marian V.

    2011-01-01

    Consumers need information to compare alternatives for markets to function efficiently. Recognizing this, public policies often pair competition with easy access to comparative information. The implicit assumption is that comparison friction—the wedge between the availability of comparative information and consumers’ use of it—is inconsequential because information is readily available and consumers will access this information and make effective choices. We examine the extent of comparison friction in the market for Medicare Part D prescription drug plans in the United States. In a randomized field experiment, an intervention group received a letter with personalized cost information. That information was readily available for free and widely advertised. However, this additional step—providing the information rather than having consumers actively access it—had an impact. Plan switching was 28 percent in the intervention group, versus 17 percent in the comparison group, and the intervention caused an average decline in predicted consumer cost of about $100 per year among letter recipients—roughly 5 percent of the cost in the comparison group. Our results suggest that comparison friction can be large even when the cost of acquiring information is small, and may be relevant for a wide range of public policies that incorporate consumer choice. PMID:22454838

  19. Comparison of density determination of liquid samples by density meters

    NASA Astrophysics Data System (ADS)

    Vámossy, C.; Davidson, S.; Zelenka, Z.

    2016-01-01

    This project was a European regional bilateral comparison of volume determination of stainless steel standards of 10 g, 20 g, and 200 g and 1 kg carried out under the auspices of EURAMET (project 1356, EURAMET.M.D-S3). The objectives of the present comparison were to check the measurement capabilities of the participants in the field of volume measurements of weights and provide a basis for the calibration measurement capabilities (CMC). BEV (Austria) was the pilot laboratory and the provider of the transfer standards. MKEH was the other participant in the bilateral comparison and NPL collected the measurement data ensuring the impartiality. The objectives of the comparison were achieved. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  20. Development of Fraction Comparison Strategies: A Latent Transition Analysis.

    PubMed

    Rinne, Luke F; Ye, Ai; Jordan, Nancy C

    2017-02-20

    The present study investigated the development of fraction comparison strategies through a longitudinal analysis of children's responses to a fraction comparison task in 4th through 6th grades (N = 394). Participants were asked to choose the larger value for 24 fraction pairs blocked by fraction type. Latent class analysis of performance over item blocks showed that most children initially exhibited a "whole number bias," indicating that larger numbers in numerators and denominators produce larger fraction values. However, some children instead chose fractions with smaller numerators and denominators, demonstrating a partial understanding that smaller numbers can yield larger fractions. Latent transition analysis showed that most children eventually adopted normative comparison strategies. Children who exhibited a partial understanding by choosing fractions with smaller numbers were more likely to adopt normative comparison strategies earlier than those with larger number biases. Controlling for general math achievement and other cognitive abilities, whole number line estimation accuracy predicted the probability of transitioning to normative comparison strategies. Exploratory factor analyses showed that over time, children appeared to increasingly represent fractions as discrete magnitudes when simpler strategies were unavailable. These results support the integrated theory of numerical development, which posits that an understanding of numbers as magnitudes unifies the process of learning whole numbers and fractions. The findings contrast with conceptual change theories, which propose that children must move from a view of numbers as counting units to a new view that accommodates fractions to overcome whole number bias. (PsycINFO Database Record

  1. Development of a Mobile Toolmark Characterization/Comparison System.

    PubMed

    Chumbley, Scott; Zhang, Song; Morris, Max; Spotts, Ryan; Macziewski, Chad

    2017-01-01

    Since the development of the striagraph, various attempts have been made to enhance forensic investigation through the use of measuring and imaging equipment. This study describes the development of a prototype system employing an easy-to-use software interface designed to provide forensic examiners with the ability to measure topography of a toolmarked surface and then conduct various comparisons using a statistical algorithm. Acquisition of the data is carried out using a portable 3D optical profilometer, and comparison of the resulting data files is made using software named "MANTIS" (Mark and Tool Inspection Suite). The system has been tested on laboratory-produced markings that include fully striated marks (e.g., screwdriver markings), quasistriated markings produced by shear-cut pliers, impression marks left by chisels, rifling marks on bullets, and cut marks produced by knives. Using the system, an examiner has the potential to (i) visually compare two toolmarked surfaces in a manner similar to a comparison microscope and (ii) use the quantitative information embedded within the acquired data to obtain an objective statistical comparison of the data files. This study shows that, based on the results from laboratory samples, the system has great potential for aiding examiners in conducting comparisons of toolmarks.

  2. Key comparison CCEM-K7: AC voltage ratio

    NASA Astrophysics Data System (ADS)

    Robinson, Ian; Belliss, Janet; Bryant, Stephen; Sánchez, Antonio; Álvarez, Yolanda; Schweiger, Kurt; Díaz, Carlos; Neira, Miguel; Callegaro, Luca; Lee, Rae Duk; Blanc, Isabelle; Overney, Frederic; He, XiaoBing; Ding, Cheng; Qian, ZhongTai; Waltrip, Bryan; Small, Greig; Fiander, John; Coogan, Peter; Johnson, Heather Leigh; Nakamura, Yasuhiro; Dierikx, Erik; Kishore Saxena, Anil; Saleem, Mohd; Wood, Barry; Ramm, Guenther; Eklund, Gunnar; Turhan, Enis; Semenov, Yuri

    2012-01-01

    We report the results of the international comparison of low-frequency ac voltage ratio: CCEM-K7. The participants made measurements of a unique travelling standard: an inductive voltage divider which provided the 20 ac voltage ratios chosen for the comparison. The nominal ratios chosen were: 0.1 to 0.9, 0.01 and 1/11 to 10/11. Each of the 17 participants measured the in-phase and quadrature components of all 20 ratios at a frequency of 1 kHz, and 7 laboratories made additional, optional, measurements at a frequency of 55 Hz. The report consists of two separate parts: the first part describes the comparison and provides detailed uncertainty budgets for each participant; the second part describes the method used to analyse the results, gives the results of the comparison and tabulates the raw data provided by each participant. Main text. To reach the main text of this paper, click on Final Report (a zip file containing the report as two pdf files: Part 1 and Part 2). Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  3. Artificial bias typically neglected in comparisons of uncertain atmospheric data

    NASA Astrophysics Data System (ADS)

    Pitkänen, Mikko R. A.; Mikkonen, Santtu; Lehtinen, Kari E. J.; Lipponen, Antti; Arola, Antti

    2016-09-01

    Publications in atmospheric sciences typically neglect biases caused by regression dilution (bias of the ordinary least squares line fitting) and regression to the mean (RTM) in comparisons of uncertain data. We use synthetic observations mimicking real atmospheric data to demonstrate how the biases arise from random data uncertainties of measurements, model output, or satellite retrieval products. Further, we provide examples of typical methods of data comparisons that have a tendency to pronounce the biases. The results show, that data uncertainties can significantly bias data comparisons due to regression dilution and RTM, a fact that is known in statistics but disregarded in atmospheric sciences. Thus, we argue that often these biases are widely regarded as measurement or modeling errors, for instance, while they in fact are artificial. It is essential that atmospheric and geoscience communities become aware of and consider these features in research.

  4. Cross-Disciplinary Network Comparison: Matchmaking Between Hairballs

    PubMed Central

    Yan, Koon-Kiu; Wang, Daifeng; Sethi, Anurag; Muir, Paul; Kitchen, Robert; Cheng, Chao; Gerstein, Mark

    2016-01-01

    Biological systems are complex. In particular, the interactions between molecular components often form dense networks that, more often than not, are criticized for being inscrutable ‘hairballs’. We argue that one way of untangling these hairballs is through cross-disciplinary network comparison—leveraging advances in other disciplines to obtain new biological insights. In some cases, such comparisons enable the direct transfer of mathematical formalism between disciplines, precisely describing the abstract associations between entities and allowing us to apply a variety of sophisticated formalisms to biology. In cases where the detailed structure of the network does not permit the transfer of complete formalisms between disciplines, comparison of mechanistic interactions in systems for which we have significant day-to-day experience can provide analogies for interpreting relatively more abstruse biological networks. Here, we illustrate how these comparisons benefit the field with a few specific examples related to network growth, organizational hierarchies, and the evolution of adaptive systems. PMID:27047991

  5. The NIH Toolbox Pattern Comparison Processing Speed Test: Normative Data

    PubMed Central

    Carlozzi, Noelle E.; Beaumont, Jennifer L.; Tulsky, David S.; Gershon, Richard C.

    2015-01-01

    The NIH Toolbox Pattern Comparison Processing Speed Test was developed to assess processing speed. While initial validation work provides preliminary support for this test in both children and adults, more work is needed to ensure dependability and generalizability. Thus, this replication study examines descriptive data (including age effects), test–retest reliability, and construct validity in n = 4,859 participants ages 3–85 years (matched to 2010 census data). Although the Pattern Comparison was not appropriate for all 3 and 4 years old, by ages 5 and 6, more meaningful scores were apparent. There was evidence for convergent and discriminant validity. There was also a moderate practice effect (i.e., increase of 5.5 points) over a 1-week time frame. Pattern Comparison exhibits a number of strengths: it is appropriate for use across the lifespan (ages 5–85), it is short and easy to administer, and there is support for construct validity. PMID:26025230

  6. A comparison of hypersonic vehicle flight and prediction results

    NASA Technical Reports Server (NTRS)

    Iliff, Kenneth W.; Shafer, Mary F.

    1995-01-01

    Aerodynamic and aerothermodynamic comparisons between flight and ground test for four hypersonic vehicles are discussed. The four vehicles are the X-15, the Reentry F, the Sandia Energetic Reentry Vehicle Experiment (SWERVE), and the Space Shuttle. The comparisons are taken from papers published by researchers active in the various programs. Aerodynamic comparisons include reaction control jet interaction on the Space Shuttle. Various forms of heating including catalytic, boundary layer, shock interaction and interference, and vortex impingement are compared. Predictions were significantly exceeded for the heating caused by vortex impingement (on the Space Shuttle OMS pods) and for heating caused by shock interaction and interference on the X-15 and the Space Shuttle. Predictions of boundary-layer state were in error on the X-15, the SWERVE, and the Space Shuttle vehicles.

  7. Price comparisons on the internet based on computational intelligence.

    PubMed

    Kim, Jun Woo; Ha, Sung Ho

    2014-01-01

    Information-intensive Web services such as price comparison sites have recently been gaining popularity. However, most users including novice shoppers have difficulty in browsing such sites because of the massive amount of information gathered and the uncertainty surrounding Web environments. Even conventional price comparison sites face various problems, which suggests the necessity of a new approach to address these problems. Therefore, for this study, an intelligent product search system was developed that enables price comparisons for online shoppers in a more effective manner. In particular, the developed system adopts linguistic price ratings based on fuzzy logic to accommodate user-defined price ranges, and personalizes product recommendations based on linguistic product clusters, which help online shoppers find desired items in a convenient manner.

  8. Comparison of immunoturbidimetric and immunonephelometric assays for specific proteins.

    PubMed

    Mali, Bahera; Armbruster, David; Serediak, Ernie; Ottenbreit, Tammy

    2009-10-01

    Immunoturbidimetric assays for specific proteins are available on "open system" clinical chemistry analyzers. The analytical performance of nine immunoturbidimetric specific protein assays (C3, C4, CRP, Haptoglobin, IgA, IgG, IgM, RF, and Transferrin) was compared to immunonephelometry. Testing was performed on the Abbott ARCHITECT ci8200 and the Dade Behring BNII nephelometer and evaluated for precision, linearity, limit of detection, prozone phenomenon, method comparison, workflow, and proficiency testing survey comparison. Immunoturbidimetric assays performance was satisfactory for total precision, linearity, limit of detection and the prozone effect was not observed. Method comparison was acceptable for the immunoglobulins, CRP and transferrin but less favorable for the other assays, likely due to methodology and antibody specificity differences. Immunourbidimetric specific protein assays allow for efficient test consolidation on a general purpose clinical chemistry analyzer.

  9. Comparison of the NIST and ENEA air kerma standards

    SciTech Connect

    Laitano, R.F.; Toni, M.P.; Lamperti, P.J.

    1998-07-01

    A comparison was made between the National Institute of Standards and Technology (NIST) and Ente per le Nuov Tecnologie l`Energia e l`Ambiente (ENEA) air kerma standards for medium energy x rays and {sup 60}Co gamma rays. The comparison took place at ENEA in June 1994. Two different transfer chambers from NIST were used for the comparison. The measurements were made at radiation qualities similar to those used at the Bureau International des Poids et Mesures (BIPM) (generating voltages of 100 kV, 135 kV, 180 kV and 250 kV, respectively) and with {sup 60}Co gamma radiation. The transfer chamber calibration factors obtained at the NIST and at the ENEA agreed with one another to 0.03% for {sup 60}Co gamma radiation and between 0.1% to 0.8% for the medium energy x-ray beam codes.

  10. Age and forgetfulness: absolute versus comparison decisions about capability.

    PubMed

    Erber, J T; Prager, I G

    1997-01-01

    Perceivers were assigned to one of two decision conditions. In an absolute decision condition, perceivers rated how likely they would be to allow a young or old highly forgetful, slightly forgetful, or nonforgetful target to perform a challenging task. In a comparison decision condition, perceivers rated two targets, one young and one old, who had a similar level of forgetfulness. Separate Decision Type x Target Forgetfulness analyses of variance were conducted on ratings of the two target age groups. Young targets received higher ratings in the comparison than in the absolute condition, whereas old targets were rated the same in the two conditions. There was some preference for young targets in a comparison situation, but it was concluded that forgetfulness was a more important factor than age in perceivers' ratings.

  11. A comparison of hypersonic flight and prediction results

    NASA Technical Reports Server (NTRS)

    Iliff, Kenneth W.; Shafer, Mary F.

    1993-01-01

    Aerodynamic and aerothermodynamic comparisons between flight and ground test for four hypersonic vehicles are discussed. The four vehicles are the X-15, the Reentry F, the Sandia Energetic Reentry Vehicle Experiment (SWERVE), and the Space Shuttle. The comparisons are taken from papers published by researchers active in the various programs. Aerodynamic comparisons include reaction control jet interaction on the Space Shuttle. Various forms of heating including catalytic, boundary layer, shock interaction and interference, and vortex impingement are compared. Predictions were significantly exceeded for the heating caused by vortex impingement (on the Space Shuttle OMS pods) and for heating caused by shock interaction and interference on the X-15 and the Space Shuttle. Predictions of boundary-layer state were in error on the X-15, the SWERVE, and the Space Shuttle vehicles.

  12. MENT reconstruction and potting comparison of a LMFBR fuel bundle

    SciTech Connect

    Betten, P.R.; Tow, D.M.

    1984-01-01

    Since the advent of computer-assisted-tomography (CAT), the CAT techniques have been rapidly expanded to the nuclear industry. A number of investigators have applied these techniques to reconstruct the fuel bundle configuration inside a subassembly with various degrees of resolution; however, there has been little data available on the accuracy of these reconstructions, and no comparisons have been made with the internal structure of actual irradiated subassemblies. Some efforts have utilized pretest mock-ups to calibrate the CAT algorithms, but the resulting mock-up configurations do not necessarily represent an actual subassembly, so an exact comparison has been lacking. The purpose of this paper is to present the results of a comparison between a CAT reconstruction of an irradiated subassembly and the destructive examination of the same subassembly.

  13. Process comparison study. MSFC Center Director's Discretionary Fund (CDDF)

    NASA Astrophysics Data System (ADS)

    Golden, T.; Krawiec, J.

    1992-11-01

    A process comparison study was conducted using four different advanced manufacturing techniques to fabricate a composite solid rocket booster systems tunnel cover. Costs and labor hours were tracked to provide the comparison between the processes. A relative structural comparison of the components is also included. The processes utilized included filament winding, pultrusion, automated tape laying, and thermoplastic thermoforming. The hand layup technique is also compared. Of the four advanced processes evaluated, the thermoformed thermoplastic component resulted in the least total cost. The automated tape laying and filament winding techniques closely followed the thermoplastic component in terms of total cost; and, these techniques show the most promise for high quality components and lower production costs. The pultruded component, with its expensive tooling and material requirements, was by far the most expensive process evaluated, although the results obtained would not be representative of large production runs.

  14. Process comparison study. MSFC Center Director's Discretionary Fund (CDDF)

    NASA Technical Reports Server (NTRS)

    Golden, T.; Krawiec, J.

    1992-01-01

    A process comparison study was conducted using four different advanced manufacturing techniques to fabricate a composite solid rocket booster systems tunnel cover. Costs and labor hours were tracked to provide the comparison between the processes. A relative structural comparison of the components is also included. The processes utilized included filament winding, pultrusion, automated tape laying, and thermoplastic thermoforming. The hand layup technique is also compared. Of the four advanced processes evaluated, the thermoformed thermoplastic component resulted in the least total cost. The automated tape laying and filament winding techniques closely followed the thermoplastic component in terms of total cost; and, these techniques show the most promise for high quality components and lower production costs. The pultruded component, with its expensive tooling and material requirements, was by far the most expensive process evaluated, although the results obtained would not be representative of large production runs.

  15. Surface dependent representations for illumination insensitive image comparison.

    PubMed

    Osadchy, Margarita; Jacobs, David W; Lindenbaum, Michael

    2007-01-01

    We consider the problem of matching images to tell whether they come from the same scene viewed under different lighting conditions. We show that the surface characteristics determine the type of image comparison method that should be used. Previous work has shown the effectiveness of comparing the image gradient direction for surfaces with material properties that change rapidly in one direction. We show analytically that two other widely used methods, normalized correlation of small windows and comparison of multiscale oriented filters, essentially compute the same thing. Then, we show that for surfaces whose properties change more slowly, comparison of the output of whitening filters is most effective. This suggests that a combination of these strategies should be employed to compare general objects. We discuss indications that Gabor jets use such a mixed strategy effectively, and we propose a new mixed strategy. We validate our results on synthetic and real images.

  16. Price Comparisons on the Internet Based on Computational Intelligence

    PubMed Central

    Kim, Jun Woo; Ha, Sung Ho

    2014-01-01

    Information-intensive Web services such as price comparison sites have recently been gaining popularity. However, most users including novice shoppers have difficulty in browsing such sites because of the massive amount of information gathered and the uncertainty surrounding Web environments. Even conventional price comparison sites face various problems, which suggests the necessity of a new approach to address these problems. Therefore, for this study, an intelligent product search system was developed that enables price comparisons for online shoppers in a more effective manner. In particular, the developed system adopts linguistic price ratings based on fuzzy logic to accommodate user-defined price ranges, and personalizes product recommendations based on linguistic product clusters, which help online shoppers find desired items in a convenient manner. PMID:25268901

  17. Development of a mobile toolmark characterization/comparison system [Development of a mobile, automated toolmark characterization/comparison system

    SciTech Connect

    Chumbley, Scott; Zhang, Song; Morris, Max; Spotts, Ryan; Macziewski, Chad

    2016-11-16

    Since the development of the striagraph, various attempts have been made to enhance forensic investigation through the use of measuring and imaging equipment. This study describes the development of a prototype system employing an easy-to-use software interface designed to provide forensic examiners with the ability to measure topography of a toolmarked surface and then conduct various comparisons using a statistical algorithm. Acquisition of the data is carried out using a portable 3D optical profilometer, and comparison of the resulting data files is made using software named “MANTIS” (Mark and Tool Inspection Suite). The system has been tested on laboratory-produced markings that include fully striated marks (e.g., screwdriver markings), quasistriated markings produced by shear-cut pliers, impression marks left by chisels, rifling marks on bullets, and cut marks produced by knives. Using the system, an examiner has the potential to (i) visually compare two toolmarked surfaces in a manner similar to a comparison microscope and (ii) use the quantitative information embedded within the acquired data to obtain an objective statistical comparison of the data files. Finally, this study shows that, based on the results from laboratory samples, the system has great potential for aiding examiners in conducting comparisons of toolmarks.

  18. Development of a mobile toolmark characterization/comparison system [Development of a mobile, automated toolmark characterization/comparison system

    DOE PAGES

    Chumbley, Scott; Zhang, Song; Morris, Max; ...

    2016-11-16

    Since the development of the striagraph, various attempts have been made to enhance forensic investigation through the use of measuring and imaging equipment. This study describes the development of a prototype system employing an easy-to-use software interface designed to provide forensic examiners with the ability to measure topography of a toolmarked surface and then conduct various comparisons using a statistical algorithm. Acquisition of the data is carried out using a portable 3D optical profilometer, and comparison of the resulting data files is made using software named “MANTIS” (Mark and Tool Inspection Suite). The system has been tested on laboratory-produced markingsmore » that include fully striated marks (e.g., screwdriver markings), quasistriated markings produced by shear-cut pliers, impression marks left by chisels, rifling marks on bullets, and cut marks produced by knives. Using the system, an examiner has the potential to (i) visually compare two toolmarked surfaces in a manner similar to a comparison microscope and (ii) use the quantitative information embedded within the acquired data to obtain an objective statistical comparison of the data files. Finally, this study shows that, based on the results from laboratory samples, the system has great potential for aiding examiners in conducting comparisons of toolmarks.« less

  19. MODIS comparisons with northeastern Pacific in situ stratocumulus microphysics

    NASA Astrophysics Data System (ADS)

    Noble, Stephen R.; Hudson, James G.

    2015-08-01

    Vertical sounding measurements within stratocumuli during two aircraft field campaigns, Marine Stratus/stratocumulus Experiment (MASE) and Physics of Stratocumulus Top (POST), are used to validate Moderate Resolution Imaging Spectroradiometer (MODIS) cloud optical thickness (COT), cloud liquid water path (LWP), and cloud effective radius (re). In situ COT, LWP, and re were calculated using 5 m vertically averaged droplet probe measurements of complete vertical cloud penetrations. MODIS COT, LWP, and re 1 km pixels were averaged along these penetrations. COT comparisons in POST showed strong correlations and a near 1:1 relationship. In MASE, comparisons showed strong correlations; however, MODIS COT exceeded in situ COT, likely due to larger temporal differences between MODIS and in situ measurements. LWP comparisons between two cloud probes show good agreement for POST but not MASE, giving confidence to POST data. Both projects provided strong LWP correlations but MODIS exceeded in situ by 14-36%. MODIS in situ re correlations were strong, but MODIS 2.1 µm re exceeded in situ re, which contributed to LWP bias; in POST, MODIS re was 20-30% greater than in situ re. Maximum in situ re near cloud top showed comparisons nearer 1:1. Other MODIS re bands (3.7 µm and 1.6 µm) showed similar comparisons. Temporal differences between MODIS and in situ measurements, airplane speed differences, and cloud probe artifacts were likely causes of weaker MASE correlations. POST COT comparison was best for temporal differences under 20 min. POST data validate MODIS COT but it also implies a positive MODIS re bias that propagates to LWP while still capturing variability.

  20. MODIS comparisons with northeastern Pacific in situ stratocumulus microphysics

    PubMed Central

    Noble, Stephen R.

    2015-01-01

    Abstract Vertical sounding measurements within stratocumuli during two aircraft field campaigns, Marine Stratus/stratocumulus Experiment (MASE) and Physics of Stratocumulus Top (POST), are used to validate Moderate Resolution Imaging Spectroradiometer (MODIS) cloud optical thickness (COT), cloud liquid water path (LWP), and cloud effective radius (r e). In situ COT, LWP, and r e were calculated using 5 m vertically averaged droplet probe measurements of complete vertical cloud penetrations. MODIS COT, LWP, and r e 1 km pixels were averaged along these penetrations. COT comparisons in POST showed strong correlations and a near 1:1 relationship. In MASE, comparisons showed strong correlations; however, MODIS COT exceeded in situ COT, likely due to larger temporal differences between MODIS and in situ measurements. LWP comparisons between two cloud probes show good agreement for POST but not MASE, giving confidence to POST data. Both projects provided strong LWP correlations but MODIS exceeded in situ by 14–36%. MODIS in situ r e correlations were strong, but MODIS 2.1 µm r e exceeded in situ r e, which contributed to LWP bias; in POST, MODIS r e was 20–30% greater than in situ r e. Maximum in situ r e near cloud top showed comparisons nearer 1:1. Other MODIS r e bands (3.7 µm and 1.6 µm) showed similar comparisons. Temporal differences between MODIS and in situ measurements, airplane speed differences, and cloud probe artifacts were likely causes of weaker MASE correlations. POST COT comparison was best for temporal differences under 20 min. POST data validate MODIS COT but it also implies a positive MODIS r e bias that propagates to LWP while still capturing variability. PMID:27708990

  1. International comparison CCQM-K66: Impurity analysis of methane

    NASA Astrophysics Data System (ADS)

    Kato, Kenji; Watanabe, Takuro; Heine, Hans-Joachim; Boissiere, C.; Schulz, G.; Woo, Jin-Chun; Seog Kim, Jin; Hyup Oh, Sang; Bae, Hyun Kil; Du Kim, Yong; Qiao, Han; Guenther, Frank R.; Rhoderick, George C.; Miller, Walter; Smeulders, Damian; Botha, Angelique; Janse van Rensburg, Mellisa; Tshilongo, James; Leshabane, Nompumelelo; Ntsasa, Napo; Milton, Martin J. T.; Vargha, Gergely; Harling, Alice; Konopelko, L. A.; Kustikov, Y. A.; Vasserman, I. I.; Zavyalov, S. V.; Popova, T. A.; Pankratov, V. V.; Pir, M. N.; Maltsev, M. A.; Oudwater, Rutger; Persijn, Stefan; van Wijk, Janneke; Wessel, Rob M.

    2012-01-01

    This key comparison was performed to demonstrate the capability of NMIs to analyse the purity of methane for use as a source gas in the preparation of standard gas mixtures. This capability is an essential requirement for the preparation of accurate standards of natural gas and some other fuels. Since it is difficult to carry out a comparison with individual samples of pure gas, the sample for this comparison was a synthetic mixture of high purity methane with selected added impurities of nitrogen, argon, carbon dioxide and ethane. These mixtures were prepared by a gas company as a batch of 10 cylinders and their homogeneity and stability were evaluated by NMIJ. The KCRVs for the four different analytes in this key comparison are based on a consensus of values reported by participants. The uncertainties in the degrees of equivalence were calculated by combining the reported uncertainties with the homogeneity of the samples and the uncertainty of the KCRV. The results submitted are generally consistent with the KCRV within the estimated uncertainties. Finally, this comparison demonstrates that the analysis of nitrogen, argon, carbon dioxide and ethane in methane at amount fractions of 1 µmol/mol to 5 µmol/mol is generally possible with an uncertainty of 5% to 10%. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  2. CCL: an algorithm for the efficient comparison of clusters

    PubMed Central

    Hundt, R.; Schön, J. C.; Neelamraju, S.; Zagorac, J.; Jansen, M.

    2013-01-01

    The systematic comparison of the atomic structure of solids and clusters has become an important task in crystallography, chemistry, physics and materials science, in particular in the context of structure prediction and structure determination of nanomaterials. In this work, an efficient and robust algorithm for the comparison of cluster structures is presented, which is based on the mapping of the point patterns of the two clusters onto each other. This algorithm has been implemented as the module CCL in the structure visualization and analysis program KPLOT. PMID:23682193

  3. EDECT: An Energy Design, Evaluation, and Comparison Tool.

    DTIC Science & Technology

    1986-01-01

    medium offices and retail stores , and private clinics are envelope dosinant examples. Conversely, system dominant buildings’ major energy loads come from...AD-A17l 261 EDECT: AN ENERGY DESIGN EVALUATION AND COMPARISON TOOL 1/2 (U) AIR FORCE INST OF TECH &RIGHT-PATTERSON AFS OH Wi D ALLEY 1986 RFIT/CI/NR...TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED EDECT: An Energy Design, Evaluation, and TlESIS/I~$ /r/t N Comparison Tool 6. PERFORMING ORG

  4. Review of the 9th NLTE code comparison workshop

    DOE PAGES

    Piron, Robin; Gilleron, Franck; Aglitskiy, Yefim; ...

    2017-02-24

    Here, we review the 9th NLTE code comparison workshop, which was held in the Jussieu campus, Paris, from November 30th to December 4th, 2015. This time, the workshop was mainly focused on a systematic investigation of iron NLTE steady-state kinetics and emissivity, over a broad range of temperature and density. Through these comparisons, topics such as modeling of the dielectronic processes, density effects or the effect of an external radiation field were addressed. The K-shell spectroscopy of iron plasmas was also addressed, notably through the interpretation of tokamak and laser experimental spectra.

  5. National Pyranometers comparison of solar thermal labs in Mexico

    NASA Astrophysics Data System (ADS)

    Castillo-Matadamas, H. A.; Molina-Vazquez, J. C.; Moreno-Quintanar, G.; Fuentes-Toledo, A.; Ortega-Avila, N.; Rodríguez-González, J. M.; Barrón-Mancilla, J. A.; Navarrete-Gonzalez, J. J.

    2017-01-01

    The results of the first national comparison of pyranometers used in testing laboratories of solar water heating are reported. In the comparison carried out at the facilities of Centro Nacional de Metrología (CENAM-México) participated three testing laboratories, a university and CENAM with seven secondary standards and first class pyranometers. The measurement results for all instruments were adequate, considering that the deviations found in all cases for global irradiance measurements greater than 500 W / m2 were in a band of +/- 2.5%, even though pyranometers have different dates of calibration.

  6. Fibre mapping analysis in composite forming: Experimental and numerical comparison

    NASA Astrophysics Data System (ADS)

    Colmars, J.; Rusanov, A.; Ta, A. T.; Naouar, N.; Boisse, P.

    2016-10-01

    The work presented here is part of European project "FibreMap", which aims at the development of an automatic quality control and feedback mechanism to improve draping of carbon fibres on complex parts. The technology that is being developed in the project include a sensor system for robust detection of fibre orientation combined with a robotic system to scan complex parts. This paper focus on a comparison procedure made to compare experimental fibre orientation with finite element simulations results. First comparison results will be shown on a complex part chosen for the project.

  7. Blue Marble Matches: Using Earth for Planetary Comparisons

    NASA Technical Reports Server (NTRS)

    Graff, Paige Valderrama

    2009-01-01

    Goal: This activity is designed to introduce students to geologic processes on Earth and model how scientists use Earth to gain a better understanding of other planetary bodies in the solar system. Objectives: Students will: 1. Identify common descriptor characteristics used by scientists to describe geologic features in images. 2. Identify geologic features and how they form on Earth. 3. Create a list of defining/distinguishing characteristics of geologic features 4. Identify geologic features in images of other planetary bodies. 5. List observations and interpretations about planetary body comparisons. 6. Create summary statements about planetary body comparisons.

  8. Comparison of induced rules based on likelihood estimation

    NASA Astrophysics Data System (ADS)

    Tsumoto, Shusaku

    2002-03-01

    Rule induction methods have been applied to knowledge discovery in databases and data mining, The empirical results obtained show that they are very powerful and that important knowledge has been extracted from datasets. However, comparison and evaluation of rules are based not on statistical evidence but on rather naive indices, such as conditional probabilities and functions of conditional probabilities. In this paper, we introduce two approaches to induced statistical comparison of induced rules. For the statistical evaluation, likelihood ratio test and Fisher's exact test play an important role: likelihood ratio statistic measures statistical information about an information table and it is used to measure the difference between two tables.

  9. Probing beyond the laser coherence time in optical clock comparisons

    NASA Astrophysics Data System (ADS)

    Hume, David B.; Leibrandt, David R.

    2016-03-01

    We develop differential measurement protocols that circumvent the laser noise limit in the stability of optical clock comparisons by synchronous probing of two clocks using phase-locked local oscillators. This allows for probe times longer than the laser coherence time, avoids the Dick effect, and supports Heisenberg-limited measurement precision. We present protocols for such frequency comparisons and develop numerical simulations of the protocols with realistic noise sources. These methods provide a route to reduce frequency ratio measurement durations by more than an order of magnitude.

  10. Preliminary Comparison of Skin Friction Measurements with CFD Predictions

    NASA Technical Reports Server (NTRS)

    Kennelly, Robert A., Jr.; Lawrence, Scott L.; Flamm, Jeffrey D.

    1999-01-01

    The work to be described was performed at the NASA Langley UPWT (4-ft supersonic), test section #2, during 21-24 May 1996. The configuration being tested was the 1.675% Ref H controls model; test conditions were Ma = 2.40, Re = 3 million/ft. This was an exploration of a new technique, and it was not intended to provide definitive comparison of measured and computed skin friction results. It is, however, hoped that the experience gained will make such a rigorous comparison possible in the future.

  11. Comparison of the dental education systems in Korea and Japan.

    PubMed

    Heo, Seok-Mo; Kim, K J; Kawamura, Makoto; Komabayashi, Takashi

    2004-04-01

    In recent years, international relationships in dentistry have grown stronger through journals, books, academies, seminars, researcher exchanges and so forth. Korea and Japan are neighbours in East Asia. However, no comparison of the dental education systems of the two countries has been published. Therefore, the authors have provided the present comparison to promote mutual understanding and to familiarise dentists around the world with dental education in these two countries. The number of dentists, life expectancy at birth, and number of decayed, missing, and filled teeth (DMFT) at age 12 years in Korea and Japan are summarised.

  12. Comparison of CNG and LNG technologies for transportation applications

    SciTech Connect

    Sinor, J.E. Consultants, Inc., Niwot, CO )

    1992-01-01

    This report provides a head-to-head comparison of compressed natural gas (CNG) and liquefied natural gas (LNG) supplied to heavy-duty vehicles. The comparison includes an assessment of the overall efficiency of the fuel delivery system, the cost of the fuel supply system, the efficiency of use in heavy-duty vehicles, and the environmental impact of each technology. The report concludes that there are applications in which CNG will have the advantage, and applications in which LNG will be preferred.

  13. Comparative genomics of green sulfur bacteria.

    PubMed

    Davenport, Colin; Ussery, David W; Tümmler, Burkhard

    2010-06-01

    Eleven completely sequenced Chlorobi genomes were compared in oligonucleotide usage, gene contents, and synteny. The green sulfur bacteria (GSB) are equipped with a core genome that sustains their anoxygenic phototrophic lifestyle by photosynthesis, sulfur oxidation, and CO(2) fixation. Whole-genome gene family and single gene sequence comparisons yielded similar phylogenetic trees of the sequenced chromosomes indicating a concerted vertical evolution of large gene sets. Chromosomal synteny of genes is not preserved in the phylum Chlorobi. The accessory genome is characterized by anomalous oligonucleotide usage and endows the strains with individual features for transport, secretion, cell wall, extracellular constituents, and a few elements of the biosynthetic apparatus. Giant genes are a peculiar feature of the genera Chlorobium and Prosthecochloris. The predicted proteins have a huge molecular weight of 10(6), and are probably instrumental for the bacteria to generate their own intimate (micro)environment.

  14. KEY COMPARISON: BIPM comparison BIPM.RI(II)-K1.Rn-222 of activity measurements of the radionuclide 222Rn

    NASA Astrophysics Data System (ADS)

    Ratel, G.; Michotte, C.; Bochud, F. O.

    2004-01-01

    Since 2001, a national metrology institute, the Institut de Radiophysique Appliquée (IRA), Switzerland, has submitted two samples of known activity of 222Rn to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM). The activities ranged from about 13 kBq to 370 kBq. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by Section II of the Consultative Committee for Ionizing Radiation (CCRI(II)), with comparison identifier BIPM.RI(II)-K1.Rn-222, according to the provisions of the Mutual Recognition Arrangement (MRA).

  15. [Development of an Excel spreadsheet for meta-analysis of indirect and mixed treatment comparisons].

    PubMed

    Tobías, Aurelio; Catalá-López, Ferrán; Roqué, Marta

    2014-01-01

    Meta-analyses in clinical research usually aimed to evaluate treatment efficacy and safety in direct comparison with a unique comparator. Indirect comparisons, using the Bucher's method, can summarize primary data when information from direct comparisons is limited or nonexistent. Mixed comparisons allow combining estimates from direct and indirect comparisons, increasing statistical power. There is a need for simple applications for meta-analysis of indirect and mixed comparisons. These can easily be conducted using a Microsoft Office Excel spreadsheet. We developed a spreadsheet for indirect and mixed effects comparisons of friendly use for clinical researchers interested in systematic reviews, but non-familiarized with the use of more advanced statistical packages. The use of the proposed Excel spreadsheet for indirect and mixed comparisons can be of great use in clinical epidemiology to extend the knowledge provided by traditional meta-analysis when evidence from direct comparisons is limited or nonexistent.

  16. Report on NIM-NMC bilateral comparison: SPRT calibration comparison from -190°C to 420°C

    NASA Astrophysics Data System (ADS)

    Sun, Jianping; Ye, Shaochun; Wang, Li; Zhang, Jintao; Kho, Haoyuan

    2016-01-01

    A bilateral comparison of local realization of the International temperature scale of 1990 (ITS-90) between National Institute of Metrology (NIM) and National Metrology Centre (NMC) was carried out over the temperature range from -190°C to 420°C. It involved six fixed points including the argon triple point, the mercury triple point, the triple point of water, the melting point of gallium, the freezing point of tin and the freezing point of zinc. In 2009, NMC asked NIM to participate in a bilateral comparison to link the NMC results to the Consultative Committee for Thermometry Key comparison 3 (CCT-K3) and facilitate the NMC's Calibration and measurement capabilities (CMCs) submission. This comparison was agreed by NIM and Asia Pacific Metrology Programme (APMP) in 2009, and registered in the Key Comparison Database (KCDB) in 2010 as CCT-K3.2. NMC supplied two 25 Ω fused silica sheath standard platinum resistance thermometers (SPRTs) as traveling standards. One of them was used at the Ga, Sn and Zn fixed points, while the other one was used at the Ar and Hg fixed point. NMC measured them before and after NIM measurement. During the comparison, a criterion for the SPRT was set as the stability at the triple point of water to be less than 0.3 mK. The results for both laboratories are summarized. A proposal for linking the NMC's comparison results to CCT-K3 is presented. The difference between NMC and NIM and the difference between NMC and the CCT-K3 Average Reference Value (ARV) using NIM as a link are reported with expanded uncertainties at each measured fixed point. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  17. Commercialising Comparison: Pearson Puts the TLC in Soft Capitalism

    ERIC Educational Resources Information Center

    Hogan, Anna; Sellar, Sam; Lingard, Bob

    2016-01-01

    This paper provides a critical policy analysis of "The Learning Curve" (TLC) (2012), an initiative developed by the multinational edu-business, Pearson, in conjunction with the Economist Intelligence Unit. "TLC" exemplifies the commercialising of comparison and the efforts of edu-businesses to strategically position themselves…

  18. Comparisons of Interventions for Rumination Maintained by Automatic Reinforcement

    ERIC Educational Resources Information Center

    Sharp, Rebecca A.; Phillips, Katrina J.; Mudford, Oliver C.

    2012-01-01

    The effectiveness of four antecedent treatments for rumination was compared for two individuals with autism, severe intellectual disabilities and long histories (at least 20 years) of rumination. Comparisons of increased meal size, supplemental feedings, fixed-time provision of peanut butter, and liquid rescheduling found liquid rescheduling to be…

  19. Comparison and Contrast between First and Second Language Learning

    ERIC Educational Resources Information Center

    Akhter, Javed; Amin, Muhammad; Saeed, Faria; Abdullah, Shumaila; Muhammad, Khair

    2016-01-01

    This research paper tends to focus on comparison and contrast between first and second language learning. It investigates the different factors that have inhibiting influences on the language learning process of the learners in the two different environments. There are many factors involved in this respect. The age factor is one of the vital…

  20. The APS SASE FEL : modeling and code comparison.

    SciTech Connect

    Biedron, S. G.

    1999-04-20

    A self-amplified spontaneous emission (SASE) free-electron laser (FEL) is under construction at the Advanced Photon Source (APS). Five FEL simulation codes were used in the design phase: GENESIS, GINGER, MEDUSA, RON, and TDA3D. Initial comparisons between each of these independent formulations show good agreement for the parameters of the APS SASE FEL.