Sample records for bacteriorhodopsin photocycle comparison

  1. Proton transfer and energy coupling in the bacteriorhodopsin photocycle (United States)

    Lanyi, J. K.


    A description of the rate constants and the energetics of the elementary reaction steps of the photocycle of bacteriorhodopsin has been helpful in understanding the mechanism of proton transport in this light-driven pump. The evidence suggests a single unbranched reaction sequence, BR-hv----K in equilibrium with L in equilibrium with M1----M2 in equilibrium with N in equilibrium with O----BR, where coupling to the proton-motive force is at the energetically and mechanistically important M1----M2 step. The consequences of site-specific mutations expressed homologously in Halobacterium halobium have revealed characteristics of the Schiff base deprotonation in the L----M1 reaction, the reorientation of the Schiff base from the extracellular to the cytoplasmic side in the M1----M2 reaction, and the reprotonation of the Schiff base in the M2----N reaction.

  2. Steady-State Characterization of Bacteriorhodopsin-D85N Photocycle (United States)

    Timucin, Dogan A.; Downie, John D.; Norvig, Peter (Technical Monitor)


    An operational characterization of the photocycle of the genetic mutant D85N of bacteriorhodopsin, BR-D85N, is presented. Steady-state bleach spectra and pump-probe absorbance data are obtained with thick hydrated films containing BR-D85N embedded in a gelatin host. Simple two- and three-state models are used to analyze the photocycle dynamics and extract relevant information such as pure-state absorption spectra, photochemical-transition quantum efficiencies, and thermal lifetimes of dominant states appearing in the photocycle, the knowledge of which should aid in the analysis of optical recording and retrieval of data in films incorporating this photochromic material. The remarkable characteristics of this material and their implications from the viewpoint of optical data storage and processing are discussed.

  3. Influence of the charge at D85 on the initial steps in the photocycle of bacteriorhodopsin. (United States)

    Sobotta, Constanze; Braun, Markus; Tittor, Jörg; Oesterhelt, D; Zinth, Wolfgang


    Studies have shown that trans-cis isomerization of retinal is the primary photoreaction in the photocycle of the light-driven proton pump bacteriorhodopsin (BR) from Halobacterium salinarum, as well as in the photocycle of the chloride pump halorhodopsin (HR). The transmembrane proteins HR and BR show extensive structural similarities, but differ in the electrostatic surroundings of the retinal chromophore near the protonated Schiff base. Point mutation of BR of the negatively charged aspartate D85 to a threonine T (D85T) in combination with variation of the pH value and anion concentration is used to study the ultrafast photoisomerization of BR and HR for well-defined electrostatic surroundings of the retinal chromophore. Variations of the pH value and salt concentration allow a switch in the isomerization dynamics of the BR mutant D85T between BR-like and HR-like behaviors. At low salt concentrations or a high pH value (pH 8), the mutant D85T shows a biexponential initial reaction similar to that of HR. The combination of high salt concentration and a low pH value (pH 6) leads to a subpopulation of 25% of the mutant D85T whose stationary and dynamic absorption properties are similar to those of native BR. In this sample, the combination of low pH and high salt concentration reestablishes the electrostatic surroundings originally present in native BR, but only a minor fraction of the D85T molecules have the charge located exactly at the position required for the BR-like fast isomerization reaction. The results suggest that the electrostatics in the native BR protein is optimized by evolution. The accurate location of the fixed charge at the aspartate D85 near the Schiff base in BR is essential for the high efficiency of the primary reaction.

  4. Schiff base switch II precedes the retinal thermal isomerization in the photocycle of bacteriorhodopsin.

    Directory of Open Access Journals (Sweden)

    Ting Wang

    Full Text Available In bacteriorhodopsin, the order of molecular events that control the cytoplasmic or extracellular accessibility of the Schiff bases (SB are not well understood. We use molecular dynamics simulations to study a process involved in the second accessibility switch of SB that occurs after its reprotonation in the N intermediate of the photocycle. We find that once protonated, the SB C15 = NZ bond switches from a cytoplasmic facing (13-cis, 15-anti configuration to an extracellular facing (13-cis, 15-syn configuration on the pico to nanosecond timescale. Significantly, rotation about the retinal's C13 = C14 double bond is not observed. The dynamics of the isomeric state transitions of the protonated SB are strongly influenced by the surrounding charges and dielectric effects of other buried ions, particularly D96 and D212. Our simulations indicate that the thermal isomerization of retinal from 13-cis back to all-trans likely occurs independently from and after the SB C15 = NZ rotation in the N-to-O transition.

  5. The back photoreaction of the M intermediate in the photocycle of bacteriorhodopsin: mechanism and evidence for two M species (United States)

    Druckmann, S.; Friedman, N.; Lanyi, J. K.; Needleman, R.; Ottolenghi, M.; Sheves, M.


    The back photoreaction of the M intermediate in the photocycle of bacteriorhodopsin is investigated both for the native pigment and its D96N mutant. The experimental setup is based on creating the M intermediate by a first pulse, followed by a (blue) laser pulse which drives the back photoreaction of M. Experiments are carried out varying the delay between the two pulses, as well as the temperature over the -25 degrees C-20 degrees C range. It is found that the kinetic patterns of the M back photoreaction change with time after the generation of this intermediate. The data provide independent evidence for the suggestion of a photocycle mechanism based on two distinct M intermediates. They are thus in keeping with the consecutive model of Varo and Lanyi (Biochemistry 30, 5016-5022; 1991), although they cannot exclude other models such as those based on branched or parallel cycles. More generally, we offer a "photochemical" approach to discriminating between intermediate stages in the photocycle which does not depend on spectroscopic and/or kinetic data. While markedly affecting the rate of the M --> N transition in the photocycle, the rate of the thermal step in back photoreaction of M, at both room and low temperatures, is not significantly affected by the D96N mutation. It is proposed that while Asp 96 is the Schiff-base protonating moiety in the M --> N transition, another residue (most probably Asp 85) reprotonates the Schiff base following light absorption by M.

  6. Volume and enthalpy changes of proton transfers in the bacteriorhodopsin photocycle studied by millisecond time-resolved photopressure measurements. (United States)

    Liu, Yan; Edens, Gregory J; Grzymski, Joseph; Mauzerall, David


    The volume and enthalpy changes associated with proton translocation steps during the bacteriorhodopsin (BR) photocycle were determined by time-resolved photopressure measurements. The data at 25 degrees C show a prompt increase in volume followed by two further increases and one decrease to the original state to complete the cycle. These volume changes are decomposed into enthalpy and inherent volume changes. The positive enthalpy changes support the argument for inherent entropy-driven late steps in the BR photocycle [Ort, D. R., and Parson, W. M. (1979) Enthalpy changes during the photochemical cycle of bacteriorhodopsin. Biophys. J. 25, 355-364]. The volume change data can be interpreted by the electrostriction effect as charges are canceled and formed during the proton transfers. A simple glutamic acid-glutamate ion model or a diglutamate-arginine-protonated water charge-delocalized model for the proton-release complex (PRC) fit the data. A conformational change with a large positive volume change is required in the slower rise (M --> N of the optical cycle) step and is reversed in the decay (N --> O --> BR) steps. The large variation in the published values for both the volume and enthalpy changes is greatly ameliorated if the values are presented per absorbed photon instead of per mole of BR. Thus, it is the highly differing assumptions about the quantum or reaction yields that cause the variations in the published results.

  7. Theory and procedures for finding a correct kinetic model for the bacteriorhodopsin photocycle. (United States)

    Hendler, R W; Shrager, R; Bose, S


    In this paper, we present the implementation and results of new methodology based on linear algebra. The theory behind these methods is covered in detail in the Supporting Information, available electronically (Shragerand Hendler). In brief, the methods presented search through all possible forward sequential submodels in order to find candidates that can be used to construct a complete model for the BR-photocycle. The methodology is limited only to forward sequential models. If no such models are compatible with the experimental data,none will be found. The procedures apply objective tests and filters to eliminate possibilities that cannot be correct, thus cutting the total number of candidate sequences to be considered. In the current application,which uses six exponentials, the total sequences were cut from 1950 to 49. The remaining sequences were further screened using known experimental criteria. The approach led to a solution which consists of a pair of sequences, one with 5 exponentials showing BR* f L(f) M(f) N O BR and the other with three exponentials showing BR* L(s) M(s) BR. The deduced complete kinetic model for the BR photocycle is thus either a single photocycle branched at the L intermediate or a pair of two parallel photocycles. Reasons for preferring the parallel photocycles are presented. Synthetic data constructed on the basis of the parallel photocycles were indistinguishable from the experimental data in a number of analytical tests that were applied.

  8. The two consecutive M substates in the photocycle of bacteriorhodopsin are affected specifically by the D85N and D96N residue replacements (United States)

    Zimanyi, L.; Cao, Y.; Chang, M.; Ni, B.; Needleman, R.; Lanyi, J. K.


    The photocycle of the proton pump bacteriorhodopsin contains two consecutive intermediates in which the retinal Schiff base is unprotonated; the reaction between these states, termed M1 and M2, was suggested to be the switch in the proton transport which reorients the Schiff base from D85 on the extracellular side to D96 on the cytoplasmic side (Varo and Lanyi, Biochemistry 30, 5016-5022, 1991). At pH 10 the absorption maxima of both M1 and M2 could be determined in the recombinant D96N protein. We find that M1 absorbs at 411 nm as do M1 and M2 in wild-type bacteriorhodopsin, but M2 absorbs at 404 nm. Thus, in M2 but not M1 the unprotonated Schiff base is affected by the D96N residue replacement. The connectivity of the Schiff base to D96 in the detected M2 state, but not in M1, is thereby established. On the other hand, the photostationary state which develops during illumination of D85N bacteriorhodopsin contains an M state corresponding to M1 with an absorption maximum shifted to 400 nm, suggesting that this species in turn is affected by D85. These results are consistent with the suggestion that M1 and M2 are pre-switch and post-switch states, respectively.

  9. Absorption characteristics of bacteriorhodopsin molecules

    Indian Academy of Sciences (India)

    H K T Kumar; K Appaji Gowda


    The bacteriorhodopsin molecule absorbs light and undergoes a series of structural transformation following a well-defined photocycle. The complex photocycle is transformed to an equivalent level diagram by considering the lifetime of the intermediate states. Assuming that only and states are appreciably populated at any instant of time, the level diagram is further simplified to two-level system. Based on the rate equations for two-level system, an analytic expression for the absorption coefficient of bacteriorhodopsin molecule is derived. It is applied to study the behaviour of absorption coefficient of bacteriorhodopsin film in the visible wavelength region of 514 nm. The dependence of absorption coefficient of bacteriorhodopsin film on the thickness of the film, total number density of active molecules and initial number density of molecules in -state is presented in the graphical form.

  10. Multi-exponentially Photoelectric Response of Bacteriorhodopsin

    Institute of Scientific and Technical Information of China (English)

    姚保利; 徐大纶; 侯洵; 胡坤生; 王敖金


    A thin oriented bacteriorhodopsin (bR) film is deposited on a stainless steel slide by use of the electrophoretic sedimentation method. A junction is made with electrolyte gels having a counterelectrode to construct a bRbased photoelectric detector. The photoelectric response signal to a 10ns laser pulse is measured. A theory on the photoelectric kinetics of bR is developed based on the concept of the charge displacement current and the bR photocycle rate equations. Comparison between the theoretical and experimental results proves that the bR photoelectric response to a short laser pulse is a multi-exponential process. The decay time constants and amplitudes of each exponential component are obtained by data fitting.

  11. Protein changes associated with reprotonation of the Schiff base in the photocycle of Asp96-->Asn bacteriorhodopsin. The MN intermediate with unprotonated Schiff base but N-like protein structure (United States)

    Sasaki, J.; Shichida, Y.; Lanyi, J. K.; Maeda, A.


    The difference Fourier transform infrared spectrum for the N intermediate in the photoreaction of the light-adapted form of bacteriorhodopsin can be recorded at pH 10 at 274 K (Pfefferle, J.-M., Maeda, A., Sasaki, J., and Yoshizawa, T. (1991) Biochemistry 30, 6548-6556). Under these conditions, Asp96-->Asn bacteriorhodopsin gives a photoproduct which shows changes in protein structure similar to those observed in N of wild-type bacteriorhodopsin. However, decreased intensity of the chromophore bands and the single absorbance maximum at about 400 nm indicate that the Schiff base is unprotonated, as in the M intermediate. This photoproduct was named MN. At pH 7, where the supply of proton is not as restricted as at pH 10, Asp96-->Asn bacteriorhodopsin yields N with a protonated Schiff base. The Asn96 residue, which cannot deprotonate as Asp96 in wild-type bacteriorhodopsin, is perturbed upon formation of both MN at pH 10 and N at pH 7. We suggest that the reprotonation of the Schiff base is preceded by a large change in the protein structure including perturbation of the residue at position 96.

  12. Photocycle of Exiguobacterium sibiricum rhodopsin characterized by low-temperature trapping in the IR and time-resolved studies in the visible. (United States)

    Dioumaev, Andrei K; Petrovskaya, Lada E; Wang, Jennifer M; Balashov, Sergei P; Dolgikh, Dmitriy A; Kirpichnikov, Mikhail P; Lanyi, Janos K


    The photocycle of the retinal protein from Exiguobacterium sibiricum, which differs from bacteriorhodopsin in both its primary donor and acceptor, is characterized by visible and infrared spectroscopy. At pH above pKa ~6.5, we find a bacteriorhodopsin-like photocycle, which originates from excitation of the all-trans retinal chromophore with K-, L-, M-, and N-like intermediates. At pH below pKa ~6.5, the M state, which reflects Schiff base deprotonation during proton pumping, is not accumulated. However, using the infrared band at ~1760 cm(-1) as a marker for transient protonation of the primary acceptor, we find that Schiff base deprotonation must have occurred at pH not only above but also below the pKa ~6.5. Thus, the M state is formed but not accumulated for kinetic reasons. Further, chromophore reisomerization from the 13-cis to the all-trans conformation occurs very late in the photocycle. The strongly red-shifted states that dominate the second half of the cycle are produced before the reisomerization step, and by this criterion, they are not O-like but rather N-like states. The assignment of photocycle intermediates enables reevaluation of the photocycle; its specific features are discussed in relation to the general mechanism of proton transport in retinal proteins.

  13. Kinetic vs. Thermodynamic Control of Bacteriorhodopsin Pumping (United States)

    Gunner, Marilyn


    Bacteriorhodopsin is a transmembrane proton pump that converts light energy to a transmembrane electrochemical gradient. Retinal, bound in the center of the protein, absorbs light and isomerizes from the all-trans to 13-cis configuration. A series of conformational changes and proton transfers then restores the structure to the all-trans ground state while pumping one proton from the high pH cell interior to the low pH exterior, saving energy in an electrochemical gradient. Poorly understood gating elements control key steps where incorrect proton transfer would return the protein to the ground state without pumping. The gate's barrier height determines how much the pump leaks. Analysis of high-resolution structures trapped in different intermediates has produced ideas for how bacteriorhodopsin ensures pumping. There are two contrasting strategies, one primarily thermodynamic and the other relying on kinetic control to ensure that protons are moved uphill. With thermodynamic control, residue protonation states always remain in quasi-equilibrium. Relatively slow conformational changes shift the energy landscape modifying site pKas. Residues then change ionization remaining in equilibrium in each metastable intermediate. The sequence of intermediates imparts the directionality to the transfers. Alternatively, the direction of transfer is determined by the accessibility of low energy pathways so is thus is under kinetic control. We will discuss which steps in the bacteriorhodopsin photocycle are under thermodynamic or under kinetic control. The role of three specific conformational changes (retinal isomerization, Arg82 reorientation and Glu194 and 204 separations) on the degree of proton transfer will be described. Supported by NFS MCB 1022208. Carried out with Yifan Song now at the University of Washington Department of Biochemistry.

  14. Trapping the M sub 1 and M sub 2 substrates of bacteriorhodopsin for electron diffraction studies

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, G.A.


    Visible and Fourier transform infrared (FTIR) absorption spectroscopies are used to observe protein conformational changes occuring during the bacteriorhodopsin photocycle. Spectroscopic measurements which define the conditions under which bacteriorhodopsin can be isolated and trapped in two distinct substates of the m intermediate of the photocycle, M{sub 1}, and M{sub 2}, are described. A protocol that can be used for high-resolution electron diffraction studies is presented that will trap glucose-embedded purple membrane in the M{sub 1}and M{sub 2} substates at greater than 90% concentration. It was discovered that glucose alone does not provide a fully hydrated environment for bacteriorhodopsin. Equilibration of glucose-embedded samples at high humidity can result in a physical state that is demonstrably closer to the native, fully hydrated state. An extension of the C-T Model of bacteriorhodopsin functionality (Fodor et al., 1988; Mathies et al., 1991) is proposed based on FTIR results and guided by published spectra from resonance Raman and FTIR work. 105 refs.

  15. Trapping the M{sub 1} and M{sub 2} substrates of bacteriorhodopsin for electron diffraction studies

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, G.A.


    Visible and Fourier transform infrared (FTIR) absorption spectroscopies are used to observe protein conformational changes occuring during the bacteriorhodopsin photocycle. Spectroscopic measurements which define the conditions under which bacteriorhodopsin can be isolated and trapped in two distinct substates of the m intermediate of the photocycle, M{sub 1}, and M{sub 2}, are described. A protocol that can be used for high-resolution electron diffraction studies is presented that will trap glucose-embedded purple membrane in the M{sub 1}and M{sub 2} substates at greater than 90% concentration. It was discovered that glucose alone does not provide a fully hydrated environment for bacteriorhodopsin. Equilibration of glucose-embedded samples at high humidity can result in a physical state that is demonstrably closer to the native, fully hydrated state. An extension of the C-T Model of bacteriorhodopsin functionality (Fodor et al., 1988; Mathies et al., 1991) is proposed based on FTIR results and guided by published spectra from resonance Raman and FTIR work. 105 refs.

  16. Reaction cycle and thermodynamics in bacteriorhodopsin (United States)

    Lanyi, J. K.


    Light causes the all-trans to 13-cis isomerization of the retinal in bacteriorhodopsin; the thermal relaxation leading back to the initial state drives proton transport first via proton transfer between the retinal Schiff base and D85 and then between the Schiff base and D96. The reaction sequence and thermodynamics of this photocycle are described by measuring time-resolved absorption changes with a gated multichannel analyzer between 100 ns and 100 ms, at six temperatures between 5 degrees C and 30 degrees C. Analysis of the energetics of the chromophore reaction sequence is on the basis of a recently proposed model (Varo & Lanyi, Biochemistry 30, 5016-5022, 1991) which consists of a single cycle and many reversible reactions: BR -hv-->KLM1-->M2NO-->BR. The existence of the M1-->M2 reaction, which functions as the switch in the proton transfer, is confirmed by spectroscopic evidence. The calculated thermodynamic parameters indicate that the exchange of free energy between the protein and the protons is at the switch step. Further, a large entropy decrease at this reaction suggests a protein conformation change which will conserve delta G for driving the completion of the reaction cycle. The results provide insights to mechanism and energy coupling in this system, with possible relevance to the general question of how ion pumps function.

  17. Crystallographic structure of the K intermediate of bacteriorhodopsin: conservation of free energy after photoisomerization of the retinal. (United States)

    Schobert, Brigitte; Cupp-Vickery, Jill; Hornak, Viktor; Smith, Steven; Lanyi, Janos


    The K state, an early intermediate of the bacteriorhodopsin photocycle, contains the excess free energy used for light-driven proton transport. The energy gain must reside in or near the photoisomerized retinal, but in what form has long been an open question. We produced the K intermediate in bacteriorhodopsin crystals in a photostationary state at 100K, with 40% yield, and determined its X-ray diffraction structure to 1.43 A resolution. In independent refinements of data from four crystals, the changes are confined mainly to the photoisomerized retinal. The retinal is 13-cis,15-anti, as known from vibrational spectroscopy. The C13=C14 bond is rotated nearly fully to cis from the initial trans configuration, but the C14-C15 and C15=NZ bonds are partially counter-rotated. This strained geometry keeps the direction of the Schiff base N-H bond vector roughly in the extracellular direction, but the angle of its hydrogen bond with water 402, that connects it to the anionic Asp85 and Asp212, is not optimal. Weakening of this hydrogen bond may account for many of the reported features of the infrared spectrum of K, and for its photoelectric signal, as well as the deprotonation of the Schiff base later in the cycle. Importantly, although 13-cis, the retinal does not assume the expected bent shape of this configuration. Comparison of the calculated energy of the increased angle of C12-C13=C14, that allows this distortion, with the earlier reported calorimetric measurement of the enthalpy gain of the K state indicates that a significant part of the excess energy is conserved in the bond strain at C13.

  18. Controlling the pKa of the bacteriorhodopsin Schiff base by use of artificial retinal analogues.



    Artificial bacteriorhodopsin pigments based on synthetic retinal analogues carrying an electron-withdrawing CF3 substituent group were prepared. The effects of CF3 on the spectra, photocycles, and Schiff base pKa values of the pigments were analyzed. A reduction of 5 units in the pKa of the Schiff base is observed when the CF3 substituent is located at the C-13 polyene position, in the vicinity of the protonated Schiff base nitrogen. The results lead to the unambiguous characterization of the...

  19. Optical and electric signals from dried oriented purple membrane of bacteriorhodopsins. (United States)

    Tóth-Boconádi, R; Dér, A; Keszthelyi, L


    All the intermediates of the bacteriorhodopsin photocycle are excitable with light of suitable wavelength. This property might regulate the activity in the cells when they are exposed in the nature to high light intensity. On the other hand this property is involved in many applications. In this study the ground state and M intermediate of dried oriented samples of wild-type bacteriorhodopsin and its mutant D96N were excited with 406 nm laser flashes. Substantial M populations were generated with quasi-continuous illumination. The decay of the absorption of M intermediate had three components: their lifetimes were very different for laser flash and quasi-continuous illuminations in cases of both bacteriorhodopsin species. The optical answer for the excitation of M intermediate had a lifetime of 2.2 ms. Electric signals for M excitation had large fast negative components and small positive components in the 100 μs time domain. The results are expected to have important implications for bioelectronic applications of bacteriorhodopsin.

  20. Electron microscopic observation and rotational diffusion measurement of bacteriorhodopsin in lipid vesicles

    Institute of Scientific and Technical Information of China (English)

    HU; Kunsheng


    [1]Stoeckenius, W.. Bacterial rhodopsins: Evolution of a mechanistic model for the ion pumps, Protein Science, 1999, 8: 447.[2]Ebrey. T. G, Light energy transduction in bacteriorhodopsin, in Thermodynamics of Membranes, Receptors and Channels (ed. Jackson. M.), New York: CRC Press, 1993. 353-387.[3]Lanyi. J. K.. Understanding structure and function in the light-driven proton pump bacteriorhodopsin, J. Struct. Biol., 1998,l24: 164.[4]Quay. S. C., Condie. C. C., Conformational studies of aqueous melittin: Thermodynamic parameters of the monomer-tetramer self-association reaction. Biochemistry, 1983, 22: 695.[5]Habermann. E.. Bee and wasp venoms. Science, 1972, 177: 314.[6]Tosteson. M. T., Holmes. S. J., Razin. M. et al., Melitton lysis of red cells, J. Membr. Biol., 1985, 87: 35.[7]Hu, K. S., Dufton, M. J., Morrison, I. E. G. et al., Cherry interaction of bee venom melittin with bacteriorhodopsin in lipid vesicles: Protein rotational diffusion measurement. Biochem. Biophys. Acta, 1985, 816(2): 358.[8]Shi, H., Hu, K. S., Huang, Y. et al., Effect of melittin on photocycle and photoresponse of purple membrane: sites of interaction between bacteriorhodopsin and melittin, Photochemistry and Photobiology, 1993, 58(3): 413.[9]Jiang. Q. X., Hu, K. S.. Shi. H., Interaction of both melittin and its site-specific mutants with bacteriorhodopsin of Halobacterium halobium: sites of electrostatic interaction on melittin Photochemistry and Photobiology, 1994, 60(2): 175.[10]Doebler, R., Basaran. N.. Goldston H. et al., Effect of protein aggregation into aqueous phase on the binding of membrane proteins to membranes, Biophys. J., 1999, 76: 928.[11]Rehorek, M., Heyn, M. P, Binding of all-trans-retinal to the purple membrane, Evidence for cooperativity and determination of the extinction coefficient, Biochemistry, 1979, 18: 4977.[12]Chen. P. S. Jr.. Toribara, T. Y., Warner, H., Microdetermination of phosphorous, Anal. Chem., t956, 28

  1. Unraveling the mechanism of proton translocation in the extracellular half-channel of bacteriorhodopsin. (United States)

    Ge, Xiaoxia; Gunner, M R


    Bacteriorhodopsin, a light activated protein that creates a proton gradient in halobacteria, has long served as a simple model of proton pumps. Within bacteriorhodopsin, several key sites undergo protonation changes during the photocycle, moving protons from the higher pH cytoplasm to the lower pH extracellular side. The mechanism underlying the long-range proton translocation between the central (the retinal Schiff base SB216, D85, and D212) and exit clusters (E194 and E204) remains elusive. To obtain a dynamic view of the key factors controlling proton translocation, a systematic study using molecular dynamics simulation was performed for eight bacteriorhodopsin models varying in retinal isomer and protonation states of the SB216, D85, D212, and E204. The side-chain orientation of R82 is determined primarily by the protonation states of the residues in the EC. The side-chain reorientation of R82 modulates the hydrogen-bond network and consequently possible pathways of proton transfer. Quantum mechanical intrinsic reaction coordinate calculations of proton-transfer in the methyl guanidinium-hydronium-hydroxide model system show that proton transfer via a guanidinium group requires an initial geometry permitting proton donation and acceptance by the same amine. In all the bacteriorhodopsin models, R82 can form proton wires with both the CC and the EC connected by the same amine. Alternatively, rare proton wires for proton transfer from the CC to the EC without involving R82 were found in an O' state where the proton on D85 is transferred to D212.

  2. A residue substitution near the beta-ionone ring of the retinal affects the M substates of bacteriorhodopsin (United States)

    Varo, G.; Zimanyi, L.; Chang, M.; Ni, B.; Needleman, R.; Lanyi, J. K.


    The switch in the bacteriorhodopsin photocycle, which reorients access of the retinal Schiff base from the extracellular to the cytoplasmic side, was suggested to be an M1----M2 reaction (Varo and Lanyi. 1991. Biochemistry. 30:5008-5015, 5016-5022). Thus, in this light-driven proton pump it is the interconversion of proposed M substates that gives direction to the transport. We find that in monomeric, although not purple membrane-lattice immobilized, D115N bacteriorhodopsin, the absorption maximum of M changes during the photocycle: in the time domain between its rise and decay it shifts 15 nm to the blue relative to the spectrum at earlier times. This large shift strongly supports the existence of two M substates. Since D115 is located near the beta-ionone ring of the retinal, the result raises questions about the possible involvement of the retinal chain or protein residues as far away as 10 A from the Schiff base in the mechanism of the switching reaction.

  3. Influence of the size and protonation state of acidic residue 85 on the absorption spectrum and photoreaction of the bacteriorhodopsin chromophore (United States)

    Lanyi, J. K.; Tittor, J.; Varo, G.; Krippahl, G.; Oesterhelt, D.


    The consequences of replacing Asp-85 with glutamate in bacteriorhodopsin, as expressed in Halobacterium sp. GRB, were investigated. Similarly to the in vitro mutated and in Escherichia coli expressed protein, the chromophore was found to exist as a mixture of blue (absorption maximum 615 nm) and red (532 nm) forms, depending on the pH. However, we found two widely separated pKa values (about 5.4 and 10.4 without added salt), arguing for two blue and two red forms in separate equilibria. Both blue and red forms of the protein are in the two-dimensional crystalline state. A single pKa, such as in the E. coli expressed protein, was observed only after solubilization with detergent. The photocycle of the blue forms was determined at pH 4.0 with 610 nm photoexcitation, and that of the red forms at pH 10.5 and with 520 nm photoexcitation, in the time-range of 100 ns to 1 s. The blue forms produced no M, but a K- and an L-like intermediate, whose spectra and kinetics resembled those of blue wild-type bacteriorhodopsin below pH 3. The red forms produced a K-like intermediate, as well as M and N. Only the red forms transported protons. Specific perturbation of the neighborhood of the Schiff base by the replacement of Asp-85 with glutamate was suggested by (1) the shift and splitting of the pKa for what is presumably the protonation of residue 85, (2) a 36 nm blue-shift in the absorption of the all-trans red chromophore and a 25 nm red-shift of the 13-cis N chromophore, as compared to wild-type bacteriorhodopsin and its N intermediate, and (3) significant acceleration of the deprotonation of the Schiff base at pH 7, but not of its reprotonation and the following steps in the photocycle.

  4. Air-Driven Potassium Iodide-Mediated Oxidative Photocyclization of Stilbene Derivatives. (United States)

    Matsushima, Tomoya; Kobayashi, Sayaka; Watanabe, Soichiro


    A new method has been developed for the potassium iodide-mediated oxidative photocyclization of stilbene derivatives. Compared with conventional iodine-mediated oxidative photocyclization reactions, this new method requires shorter reaction times and affords cyclized products in yields of 45-97%. This reaction proceeds with a catalytic amount of potassium iodide and works in an air-driven manner without the addition of an external scavenger. The radical-mediated oxidative photocyclization of stilbene derivatives using TEMPO was also investigated.

  5. All-Optical Arithmetic and Combinatorial Logic Circuits with High-Q Bacteriorhodopsin Coated Microcavities

    CERN Document Server

    Roy, Sukhdev; Topolancik, Juraj; Vollmer, Frank


    We present designs of all-optical computing circuits, namely, half-full adder/subtractor, de-multiplexer, multiplexer, and an arithmetic unit, based on bacteriorhodopsin (BR) protein coated microcavity switch in a tree architecture. The basic all-optical switch consists of an input infrared (IR) laser beam at 1310 nm in a single mode fiber (SMF-28) switched by a control pulsed laser beam at 532 nm, which triggers the change in the resonance condition on a silica bead coated with BR between two tapered fibers. We show that fast switching of 50 us can be achieved by injecting a blue laser beam at 410 nm that helps in truncating the BR photocycle at the M intermediate state. Realization of all-optical switch with BR coated microcavity switch has been done experimentally. Based on this basic switch configuration, designs of all-optical higher computing circuits have been presented. The design requires 2n-1 switches to realize n bit computation. The proposed designs require less number of switches than terahertz o...

  6. Aspartic acid-96 is the internal proton donor in the reprotonation of the Schiff base of bacteriorhodopsin. (United States)

    Otto, H; Marti, T; Holz, M; Mogi, T; Lindau, M; Khorana, H G; Heyn, M P


    Above pH 8 the decay of the photocycle intermediate M of bacteriorhodopsin splits into two components: the usual millisecond pH-independent component and an additional slower component with a rate constant proportional to the molar concentration of H+, [H+]. In parallel, the charge translocation signal associated with the reprotonation of the Schiff base develops a similar slow component. These observations are explained by a two-step reprotonation mechanism. An internal donor first reprotonates the Schiff base in the decay of M to N and is then reprotonated from the cytoplasm in the N----O transition. The decay rate of N is proportional to [H+]. By postulating a back reaction from N to M, the M decay splits up into two components, with the slower one having the same pH dependence as the decay of N. Photocycle, photovoltage, and pH-indicator experiments with mutants in which aspartic acid-96 is replaced by asparagine or alanine, which we call D96N and D96A, suggest that Asp-96 is the internal proton donor involved in the re-uptake pathway. In both mutants the stoichiometry of proton pumping is the same as in wild type. However, the M decay is monophasic, with the logarithm of the decay time [log (tau)] linearly dependent on pH, suggesting that the internal donor is absent and that the Schiff base is directly reprotonated from the cytoplasm. Like H+, azide increases the M decay rate in D96N. The rate constant is proportional to the azide concentration and can become greater than 100 times greater than in wild type. Thus, azide functions as a mobile proton donor directly reprotonating the Schiff base in a bimolecular reaction. Both the proton and azide effects, which are absent in wild type, indicate that the internal donor is removed and that the reprotonation pathway is different from wild type in these mutants. PMID:2556706

  7. Searching for a photocycle of the cryptochrome photoreceptors. (United States)

    Liu, Bin; Liu, Hongtao; Zhong, Dongping; Lin, Chentao


    The initial photochemistry of plant cryptochromes has been extensively investigated in recent years. It is hypothesized that cryptochrome photoexcitation involves a Trp-triad-dependent photoreduction. According to this hypothesis, cryptochromes in the resting state contain oxidized FAD; light triggers a sequential electron transfer from three tryptophan residues to reduce FAD to a neutral semiquinone (FADH*); FADH* is the presumed signaling state and it is re-oxidized to complete the photocycle. However, this photoreduction hypothesis is currently under debate. An alternative model argues that the initial photochemistry of cryptochromes involves a photolyase-like cyclic electron shuttle without a bona fide redox reaction mediated by the Trp-triad residues, leading to conformational changes, signal propagation, and physiological responses.

  8. Continuous flow photocyclization of stilbenes – scalable synthesis of functionalized phenanthrenes and helicenes

    Directory of Open Access Journals (Sweden)

    Quentin Lefebvre


    Full Text Available A continuous flow oxidative photocyclization of stilbene derivatives has been developed which allows the scalable synthesis of backbone functionalized phenanthrenes and helicenes of various sizes in good yields.

  9. Bacteriorhodopsin: Tunable Optical Nonlinear Magnetic Response

    CERN Document Server

    Bovino, F A; Sibilia, C; Giardina, M; Váró, G; Gergely, C


    We report on a strong and tunable magnetic optical nonlinear response of Bacteriorhodopsin (BR) under "off resonance" femtosecond (fs) pulse excitation, by detecting the polarization map of the noncollinear second harmonic signal of an oriented BR film, as a function of the input beam power. BR is a light-driven proton pump with a unique photochemistry initiated by the all trans retinal chromophore embedded in the protein. An elegant application of this photonic molecular machine has been recently found in the new area of optogenetics, where genetic expression of BR in brain cells conferred a light responsivity to the cells enabling thus specific stimulation of neurons. The observed strong tunable magnetic nonlinear response of BR might trigger promising applications in the emerging area of pairing optogenetics and functional magnetic resonance imaging susceptible to provide an unprecedented complete functional mapping of neural circuits.

  10. Electron microscopic observation and rotational diffusion measurement of bacteriorhodopsin in lipid vesicles

    Institute of Scientific and Technical Information of China (English)


    The morphology of bacteriorhodopsin reconstituted into dimyristoylphosphatidylcholine and egg-phosphatidylcholine vesicles was observed by freeze-fracture electron microscopy. The rotational diffusion of bacteriorhodopsin at different concentrations of melittin was measured by observing flash-induced transient dichroism in dimyristoylphosphatidylcholine vesicles. In the presence of melittin, bacteriorhodopsin molecules in dimyristoylphosphatidylcholine vesicles were aggregated into large particles or patches, and the ability of rotational diffusion of bacteriorhodop sin in vesicles was decreased. This suggests that melittin produces its effect via direct electrostatic interaction with bacteriorhodopsin. Low temperature-induced aggregation of bacteriorhodopsin was also observed in dimyristoylphosphatidylcholine vesicles. Low temperature may cause phase separation. Bacteriorhodopsin was also successfully reconstituted into egg-phosphatidylcholine vesicles, but Iow temperature-induced aggregation of bacteriorhodopsin in dimyristoylphosphati dylcholine cannot appear in egg-phosphatidylcholine vesicles. This suggests that different lipids have different effects on bacteriorhodopsin in vesicles.

  11. Photocycle dynamics of the E149A mutant of cryptochrome 3 from Arabidopsis thaliana. (United States)

    Zirak, P; Penzkofer, A; Moldt, J; Pokorny, R; Batschauer, A; Essen, L-O


    The E149A mutant of the cryDASH member cryptochrome 3 (cry3) from Arabidopsis thaliana was characterized in vitro by optical absorption and emission spectroscopic studies. The mutant protein non-covalently binds the chromophore flavin adenine dinucleotide (FAD). In contrast to the wild-type protein it does not bind N5,N10-methenyl-5,6,7,8-tetrahydrofolate (MTHF). Thus, the photo-dynamics caused by FAD is accessible without the intervening coupling with MTHF. In dark adapted cry3-E149A, FAD is present in the oxidized form (FAD(ox)), semiquinone form (FADH(.)), and anionic hydroquinone form (FAD(red)H(-)). Blue-light photo-excitation of previously unexposed cry3-E149A transfers FAD(ox) to the anionic semiquinone form (FAD()(-)) with a quantum efficiency of about 2% and a back recovery time of about 10s (photocycle I). Prolonged photo-excitation leads to an irreversible protein re-conformation with structure modification of the U-shaped FAD and enabling proton transfer. Thus, a change in the photocycle dynamics occurs with photo-conversion of FAD(ox) to FADH(.), FADH(.) to FAD(red)H(-), and thermal back equilibration in the dark (photocycle II). The photocycle dynamics of cry3-E149A is compared with the photocycle behaviour of wild-type cry3 and other photo-sensory cryptochromes.

  12. Computer-generated holograms recorded in bacteriorhodopsin (United States)

    Guessous, Fouad; Juchem, Thorsten; Hampp, Norbert A.


    Computer-generated holograms (CGH's) of phase modulation type have been designed and fabricated in the biological material Bacteriorhodopsin (BR). BR is a photochromic retinal protein which may be used in optical data storage and security applications. Using the permanent light-inducible refractive index change of BR, we demonstrate that both analog and digital optical data can be stored in this material in a write-once-read-many (WORM) mode. The calculation and the optimization of the phase function of the CGH's have been accomplished with iterative Fourier transform algorithm methods (IFTA) such as error reduction algorithms. In the fabrication procedure the optimized phase functions of the CGH's have been recorded in BR which was coated onto a glass substrate. A direct laser writing process employing the 532 nm line of a cw-Nd:YAG laser was used for recording the CGH as a modulation of the absorption coefficient as well as of the refractive index. The design and fabrication method of the CGHs with a pixel pitch of 20 μm and a total size of 10 mm x 10 mm are presented.

  13. Measurements of photoinduced refractive index changes in bacteriorhodopsin films

    Indian Academy of Sciences (India)

    Ravinder Kumar Banyal; B Raghavendra Prasad


    We report the pump-probe measurements of nonlinear refractive index changes in photochromic bacteriorhodopsin films. The photoinduced absorption is caused by pump beam at 532 nm and the accompanying refractive index changes are studied using a probe beam at 633 nm. The proposed technique is based on a convenient and accurate determination of optical path difference using digital interferometry-based local fringe shift. The results are presented for the wild-type as well as genetically modified D96N variant of the bacteriorhodopsin.

  14. Replacement of aspartic acid-96 by asparagine in bacteriorhodopsin slows both the decay of the M intermediate and the associated proton movement. (United States)

    Holz, M; Drachev, L A; Mogi, T; Otto, H; Kaulen, A D; Heyn, M P; Skulachev, V P; Khorana, H G


    The photocycle, electrical charge translocation, and release and uptake of protons from the aqueous phase and release and uptake of protons from the aqueous phase were investigated for bacteriorhodopsin mutants with aspartic acid-96 replaced by asparagine or glutamic acid. At neutral pH the main effect of the Asp-96----Asn mutation is to slow by 2 orders of magnitude the decay of the M intermediate and the concomitant charge displacement associated with the reprotonation of the Schiff base from the cytoplasmic side of the membrane. The proton uptake measured with the indicator dye pyranine is likewise slowed without affecting the stoichiometry of proton pumping. The corresponding results for the Asp-96----Glu mutant, on the other hand, are very close to those for the wild-type protein. These results provide a kinetic explanation for the fact that at pH 7 and saturating light intensities the steady-state proton pumping is almost abolished in the Asp-96----Asn mutant but is close to normal in the Asp-96----Glu mutant. Thus, the pump is simply turning over much more slowly in the Asp-96----Asn mutant. The time constants of the decay of M and the associated charge translocation increase strongly with increasing pH for the Asp-96----Asn mutant but are virtually pH-independent for the Asp-96----Glu mutant and wild-type bacteriorhodopsin. At pH 5 the M decay of the Asp-96----Asn mutant is as fast as for wild type. These results suggest that Asp-96 serves as an internal proton donor in the proton-uptake pathway from the cytoplasm to the Schiff base. PMID:2648392

  15. Optical CDMA system using bacteriorhodopsin for optical data storage (United States)

    Bae; Yang; Jin; Lee; Park


    An optical CDMA (code division multiple access) system for the optical data storage using bacteriorhodopsin (BR) is reported as an application of the BR materials. The desired signal of multiple input can be recorded and reconstructed by use of orthogonal codes. An experimental setup is proposed and demonstrated.

  16. Aspartic acid substitutions affect proton translocation by bacteriorhodopsin. (United States)

    Mogi, T; Stern, L J; Marti, T; Chao, B H; Khorana, H G


    We have substituted each of the aspartic acid residues in bacteriorhodopsin to determine their possible role in proton translocation by this protein. The aspartic acid residues were replaced by asparagines; in addition, Asp-85, -96, -115, and -112 were changed to glutamic acid and Asp-212 was also replaced by alanine. The mutant bacteriorhodopsin genes were expressed in Escherichia coli and the proteins were purified. The mutant proteins all regenerated bacteriorhodopsin-like chromophores when treated with a detergent-phospholipid mixture and retinal. However, the rates of regeneration of the chromophores and their lambda max varied widely. No support was obtained for the external point charge model for the opsin shift. The Asp-85----Asn mutant showed not detectable proton pumping, the Asp-96----Asn and Asp-212----Glu mutants showed less than 10% and the Asp-115----Glu mutant showed approximately equal to 30% of the normal proton pumping. The implications of these findings for possible mechanisms of proton translocation by bacteriorhodopsin are discussed. PMID:3288985

  17. Energy transfer processes in semiconductor quantum dots: bacteriorhodopsin hybrid system (United States)

    Rakovich, Aliaksandra; Sukhanova, Alyona; Bouchonville, Nicolas; Molinari, Michael; Troyon, Michel; Cohen, Jacques H. M.; Rakovich, Yury; Donegan, John F.; Nabiev, Igor


    The potential impact of nanoscience on energy transfer processes in biomolecules was investigated on the example of a complex between fluorescent semiconductor nanocrystals and photochromic membrane protein. The interactions between colloidal CdTe quantum dots (QDs) and bacteriorhodopsin (bR) protein were studied by a variety of spectroscopic techniques, including integrated and time-resolved fluorescence spectroscopies, zeta potential and size measurement, and fluorescence correlation spectroscopy. QDs' luminescence was found to be strongly modulated by bacteriorhodopsin, but in a controllable way. Decreasing emission lifetimes and blue shifts in QDs' emission at increasing protein concentrations suggest that quenching occurs via Förster resonance energy transfer. On the other hand, concave Stern-Volmer plots and sigmoidal photoluminescence quenching curves imply that the self-assembling of NCs and bR exists, and the number of nanocrystals (NCs) per bacteriorhodopsin contributing to energy transfer can be determined from the inflection points of sigmoidal curves. This number was found to be highly dependent not only on the spectral overlap between NC emission and bR absorption bands, but also on nanocrystal surface charge. These results demonstrate the potential of how inorganic nanoscale materials can be employed to improve the generic molecular functions of biomolecules. The observed interactions between CdTe nanocrystals and bacteriorhodopsin can provide the basis for the development of novel functional materials with unique photonic properties and applications in areas such as all-optical switching, photovoltaics and data storage.

  18. Voltage dependence of proton pumping by bacteriorhodopsin mutants with altered lifetime of the M intermediate.

    Directory of Open Access Journals (Sweden)

    Sven Geibel

    Full Text Available The light-driven proton pump bacteriorhodopsin (BR from Halobacterium salinarum is tightly regulated by the [H(+] gradient and transmembrane potential. BR exhibits optoelectric properties, since spectral changes during the photocycle are kinetically controlled by voltage, which predestines BR for optical storage or processing devices. BR mutants with prolonged lifetime of the blue-shifted M intermediate would be advantageous, but the optoelectric properties of such mutants are still elusive. Using expression in Xenopus oocytes and two-electrode voltage-clamping, we analyzed photocurrents of BR mutants with kinetically destabilized (F171C, F219L or stabilized (D96N, D96G M intermediate in response to green light (to probe H(+ pumping and blue laser flashes (to probe accumulation/decay of M. These mutants have divergent M lifetimes. As for BR-WT, this strictly correlates with the voltage dependence of H(+ pumping. BR-F171C and BR-F219L showed photocurrents similar to BR-WT. Yet, BR-F171C showed a weaker voltage dependence of proton pumping. For both mutants, blue laser flashes applied during and after green-light illumination showed reduced M accumulation and shorter M lifetime. In contrast, BR-D96G and BR-D96N exhibited small photocurrents, with nonlinear current-voltage curves, which increased strongly in the presence of azide. Blue laser flashes showed heavy M accumulation and prolonged M lifetime, which accounts for the strongly reduced H(+ pumping rate. Hyperpolarizing potentials augmented these effects. The combination of M-stabilizing and -destabilizing mutations in BR-D96G/F171C/F219L (BR-tri shows that disruption of the primary proton donor Asp-96 is fatal for BR as a proton pump. Mechanistically, M destabilizing mutations cannot compensate for the disruption of Asp-96. Accordingly, BR-tri and BR-D96G photocurrents were similar. However, BR-tri showed negative blue laser flash-induced currents even without actinic green light, indicating

  19. Incoherent manipulation of the photoactive yellow protein photocycle with dispersed pump-dump-probe spectroscopy.

    NARCIS (Netherlands)

    Larsen, D.S.; van Stokkum, I.H.M.; Vengris, M.; van der Horst, M.A.; de Weerd, F.; Hellingwerf, K.J.; van Grondelle, R.


    Photoactive yellow protein is the protein responsible for initiating the ``blue-light vision¿¿ of Halorhodospira halophila. The dynamical processes responsible for triggering the photoactive yellow protein photocycle have been disentangled with the use of a novel application of dispersed ultrafast p

  20. A novel approach to indoloditerpenes by Nazarov photocyclization: synthesis and biological investigations of terpendole E analogues. (United States)

    Churruca, Fátima; Fousteris, Manolis; Ishikawa, Yuichi; Rekowski, Margarete von Wantoch; Hounsou, Candide; Surrey, Thomas; Giannis, Athanassios


    The application of the Nazarov photocyclization as a mild and efficient method for access to the basic core of novel indoloditerpenoid derivatives is reported. The detailed synthesis of these new analogues of terpendole E, as well as their evaluation as potential inhibitors of KSP, is described.

  1. Kinetic Modeling of the Arabidopsis Cryptochrome Photocycle: FADHo Accumulation Correlates with Biological Activity (United States)

    Procopio, Maria; Link, Justin; Engle, Dorothy; Witczak, Jacques; Ritz, Thorsten; Ahmad, Margaret


    Cryptochromes are flavoprotein photoreceptors with multiple signaling roles during plant de-etiolation and development. Arabidopsis cryptochromes (cry1 and cry2) absorb light through an oxidized flavin (FADox) cofactor which undergoes reduction to both FADH° and FADH− redox states. Since the FADH° redox state has been linked to biological activity, it is important to estimate its concentration formed upon illumination in vivo. Here we model the photocycle of isolated cry1 and cry2 proteins with a three-state kinetic model. Our model fits the experimental data for flavin photoconversion in vitro for both cry1 and cry2, providing calculated quantum yields which are significantly lower in cry1 than for cry2. The model was applied to the cryptochrome photocycle in vivo using biological activity in plants as a readout for FADH° concentration. The fit to the in vivo data provided quantum yields for cry1 and cry2 flavin reduction similar to those obtained in vitro, with decreased cry1 quantum yield as compared to cry2. These results validate our assumption that FADH° concentration correlates with biological activity. This is the first reported attempt at kinetic modeling of the cryptochrome photocycle in relation to macroscopic signaling events in vivo, and thereby provides a theoretical framework to the components of the photocycle that are necessary for cryptochrome response to environmental signals. PMID:27446119

  2. Kinetic Modeling of the Arabidopsis Cryptochrome Photocycle: FADH(o) Accumulation Correlates with Biological Activity. (United States)

    Procopio, Maria; Link, Justin; Engle, Dorothy; Witczak, Jacques; Ritz, Thorsten; Ahmad, Margaret


    Cryptochromes are flavoprotein photoreceptors with multiple signaling roles during plant de-etiolation and development. Arabidopsis cryptochromes (cry1 and cry2) absorb light through an oxidized flavin (FADox) cofactor which undergoes reduction to both FADH° and FADH(-) redox states. Since the FADH° redox state has been linked to biological activity, it is important to estimate its concentration formed upon illumination in vivo. Here we model the photocycle of isolated cry1 and cry2 proteins with a three-state kinetic model. Our model fits the experimental data for flavin photoconversion in vitro for both cry1 and cry2, providing calculated quantum yields which are significantly lower in cry1 than for cry2. The model was applied to the cryptochrome photocycle in vivo using biological activity in plants as a readout for FADH° concentration. The fit to the in vivo data provided quantum yields for cry1 and cry2 flavin reduction similar to those obtained in vitro, with decreased cry1 quantum yield as compared to cry2. These results validate our assumption that FADH° concentration correlates with biological activity. This is the first reported attempt at kinetic modeling of the cryptochrome photocycle in relation to macroscopic signaling events in vivo, and thereby provides a theoretical framework to the components of the photocycle that are necessary for cryptochrome response to environmental signals.

  3. Biological Significance of Photoreceptor Photocycle Length: VIVID Photocycle Governs the Dynamic VIVID-White Collar Complex Pool Mediating Photo-adaptation and Response to Changes in Light Intensity.

    Directory of Open Access Journals (Sweden)

    Arko Dasgupta


    Full Text Available Most organisms on earth sense light through the use of chromophore-bearing photoreceptive proteins with distinct and characteristic photocycle lengths, yet the biological significance of this adduct decay length is neither understood nor has been tested. In the filamentous fungus Neurospora crassa VIVID (VVD is a critical player in the process of photoadaptation, the attenuation of light-induced responses and the ability to maintain photosensitivity in response to changing light intensities. Detailed in vitro analysis of the photochemistry of the blue light sensing, FAD binding, LOV domain of VVD has revealed residues around the site of photo-adduct formation that influence the stability of the adduct state (light state, that is, altering the photocycle length. We have examined the biological significance of VVD photocycle length to photoadaptation and report that a double substitution mutant (vvdI74VI85V, previously shown to have a very fast light to dark state reversion in vitro, shows significantly reduced interaction with the White Collar Complex (WCC resulting in a substantial photoadaptation defect. This reduced interaction impacts photoreceptor transcription factor WHITE COLLAR-1 (WC-1 protein stability when N. crassa is exposed to light: The fast-reverting mutant VVD is unable to form a dynamic VVD-WCC pool of the size required for photoadaptation as assayed both by attenuation of gene expression and the ability to respond to increasing light intensity. Additionally, transcription of the clock gene frequency (frq is sensitive to changing light intensity in a wild-type strain but not in the fast photo-reversion mutant indicating that the establishment of this dynamic VVD-WCC pool is essential in general photobiology and circadian biology. Thus, VVD photocycle length appears sculpted to establish a VVD-WCC reservoir of sufficient size to sustain photoadaptation while maintaining sensitivity to changing light intensity. The great diversity

  4. Solid-state NMR studies of bacteriorhodopsin and the purple membrane

    CERN Document Server

    Mason, A J


    proteins. This technique may prove particularly useful when studying large proteins that are difficult to orient where the MAS lineshapes will remain relatively unaffected in comparison with current static NMR methods. Finally the MAOSS method was extended to the study of the lipid components of the purple membrane and the feasibility of determining structural constraints from phospholipid headgroups was assessed. The potential of using sup 3 sup 1 P NMR to observe qualitative protein-lipid interactions in both the purple membrane and reconstituted membranes containing bovine rhodopsin was also demonstrated. Following the demonstration of a new MAS NMR method for resolving orientational constraints in uni-axially oriented biological membranes (Glaubitz and Watts, 1998), experiments were performed to realise the potential of the new method on large, oriented membrane proteins. Using bacteriorhodopsin in the purple membrane as a paradigm for large membrane proteins, the protein was specifically labelled with de...

  5. Do Cation-π Interactions Exist in Bacteriorhodopsin

    Institute of Scientific and Technical Information of China (English)

    HU Kun-Sheng; WANG Guang-Yu; HE Jin-An


    Metal ions are essential to the structure and physiological functions of bacteriorhodopsin. Experimental evidence suggests the existence of specific cation binding to the negatively charged groups of Asp85 and Asp212 via an electrostatic interaction. However, only using electrostatic force is not enough to explain the role of the metal cations because the carboxylate of Asp85 is well known to be protonated in the M intermediate. Considering the presence of some aromatic amino acid residues in the vicinity of the retinal pocket, the existence of cation-π interactions between the metal cation and aromatic amino acid residues is suggested. Obviously, introduction of this kind of interaction is conducive to understanding the effects of the metal cations and aromatic amino acid residues inside the protein on the structural stability and proton pumping of bacteriorhodopsin.

  6. Illumination-dependent changes in the intrinsic fluorescence of bacteriorhodopsin (United States)

    Bogomolni, R. A.; Stubbs, L.; Lanyi, J. K.


    The paper describes the intrinsic UV fluorescence of bacteriorhodopsin in some detail and determines the changes during the rapid cyclic reaction following light flashes. The results suggest that several tryptophan residues are affected in the protein, among them one or more exposed to aqueous medium. The kinetics of the fluorescence changes coincide closely with events involving the retinal residue during the deprotonation and reprotonation of the Schiff base group.

  7. All-optical logic-gates based on bacteriorhodopsin film

    Institute of Scientific and Technical Information of China (English)

    Chen Gui-Ying; Zhang Chun-Ping; Guo Zong-Xia; Tian Jian-Guo; Zhang Guang-Yin; Song Qi-Wang


    Based on self-diffraction in bacteriorhodopsin (bR) film, we propose all-optical NOT, XOR, half adder and XNOR logic operations. Using the relation between diffraction light and the polarization states of recording beams, we demonstrate NOT and XNOR logic operations. Studying the relation of polarization states among the diffracting, recording and reading beams, we implement XOR logic and half adder operations with three inputs. The methods are simple and practicable.

  8. In vivo absorption spectra of the two stable states of the Euglena photoreceptor photocycle. (United States)

    Barsanti, Laura; Coltelli, Primo; Evangelista, Valtere; Passarelli, Vincenzo; Frassanito, Anna Maria; Vesentini, Nicoletta; Santoro, Fabrizio; Gualtieri, Paolo


    Euglena gracilis possesses a simple but sophisticated light detecting system, consisting of an eyespot formed by carotenoids globules and a photoreceptor. The photoreceptor of Euglena is characterized by optical bistability, with two stable states. In order to provide important and discriminating information on the series of structural changes that Euglena photoreceptive protein(s) undergoes inside the photoreceptor in response to light, we measured the in vivo absorption spectra of the two stable states A and B of photoreceptor photocycle. Data were collected using two different devices, i.e. a microspectrophotometer and a digital microscope. Our results show that the photocycle and the absorption spectra of the photoreceptor possess strong spectroscopic similarities with a rhodopsin-like protein. Moreover, the analysis of the absorption spectra of the two stable states of the photoreceptor and the absorption spectrum of the eyespot suggests an intriguing hypothesis for the orientation of microalgae toward light.

  9. The dark recovery rate in the photocycle of the bacterial photoreceptor YtvA is affected by the cellular environment and by hydration.

    Directory of Open Access Journals (Sweden)

    Francesca Pennacchietti

    Full Text Available We report thermal recovery kinetics of the lit state into the parental dark state, measured for the blue light-sensing photoreceptor YtvA inside overexpressing E. coli and B. subtilis bacterial cells, performed for the wild type and several mutated proteins. Recovery was followed as a recovery of the fluorescence, as this property is only found for the parental but not for the photochemically generated lit state. When cells were deposited onto a microscope glass plate, the observed thermal recovery rate in the photocycle was found ca. ten times faster in comparison to purified YtvA in solution. When the E. coli or B. subtilis colonies were soaked in an isotonic buffer, the dark relaxation became again much slower and was very similar to that observed for YtvA in solution. The observed effects show that rate constants can be tuned by the cellular environment through factors such as hydration.

  10. Spectral Signatures of the Pentagonal Water Cluster in Bacteriorhodopsin

    Energy Technology Data Exchange (ETDEWEB)

    Baer, M; Mathias, G; Kuo, I W; Tobias, D J; Mundy, C J; Marx, D


    The exchange of protons between basic and acidic groups within proteins often involves transient protonation of amino acids and water molecules embedded in the protein matrix. One of the best studied proteins in this respect is Bacteriorohodopsin (BR), which works in the membrane of Halobacterium salinarium as a light-driven proton pump. The pumping process is triggered in the initial bR state by a photon absorption of an all-trans retinylidene chromophore, which is linked via a protonated Schiff base (pRSB) to the sidechain of Lys216. The subsequent photocycle comprises a series of intermediate states J, K, L, M, N and O, which are characterized by conformational and absorbance changes of the chromophore accompanying several elementary proton transfer processes. Upon completion of the photocycle one net proton has been transferred from the cyctoplasmic to the extracellular side against the proton gradient across the membrane. These proton exchange reactions can be monitored by time resolved infrared (IR) spectroscopy of the BR wild type and site specific mutants, which allow the localization of absorbance changes within the protein. Furthermore, these measurements have revealed the fundamental importance of internal water molecules in these processes as supported by recent large-scale QM/MM molecular dynamics studies of anharmonic IR spectra.

  11. Light-Induced Charge Separation and Transfer in Bacteriorhodopsin

    Institute of Scientific and Technical Information of China (English)

    HUANG Yu-Hua; LI Qing-Guo; ZHAO You-Yuan; ZHANG Zhong-Bin; OU-YANG Xiao-Ping; GONG Qin-Gan; CHEN Ling-Bing; LI Fu-Ming; LIU Jian; DING Jian-Dong


    The photo-voltage signals in bacteriorhodopsin(bR) excited by 1064nm pulse laser are different from those by 532 or 355 nm. It shows that the positive and negative photoelectric signals are produced by the motion of the positive and negative charges, respectively, and more energy is needed for producing the positive charges than the negative. The mechanism of light-induced charge generation and charge transfer in bR was studied and analyzed by measuring the photoelectric signals with different impedance of measuring circuit and different pulse-width of 532 nm laser as pump light.

  12. The behaviours of optical novelty filter based on bacteriorhodopsin film

    Institute of Scientific and Technical Information of China (English)

    Chen Gui-Ying; Yuan Yi-Zhe; Liang Xin; Xu Tang; Zhang Chun-Ping; Song Qi-Wang


    The quality of the novelty filter image is investigated at different intensities of the incident blue and yellow beams irradiating a bacteriorhodopsin (bR) film. The relationship between the transmitted blue beams and the incident yellow beams is established. The results show that the contrast of the novelty filter image depends on the lifetime of longest lived photochemical state (M state). These results enable one to identify the direction of a moving object and to improve the quality of the novel filter image by prolonging the lifetime of M state.

  13. Mixed Potential Energy Surfaces of the Ultrafast Isomerization of Retinal in Bacteriorhodopsin

    Directory of Open Access Journals (Sweden)

    Prokhorenko Valentyn I.


    Full Text Available We observe, using electronic two-dimensional photon echo spectroscopy, that the cis and trans potential energy surfaces of the ultrafast isomerization of retinal in bacteriorhodopsin are mixed via the hydrogen out of plane (HOOP mode.

  14. Millitesla magnetic field effects on the photocycle of an animal cryptochrome. (United States)

    Sheppard, Dean M W; Li, Jing; Henbest, Kevin B; Neil, Simon R T; Maeda, Kiminori; Storey, Jonathan; Schleicher, Erik; Biskup, Till; Rodriguez, Ryan; Weber, Stefan; Hore, P J; Timmel, Christiane R; Mackenzie, Stuart R


    Drosophila have been used as model organisms to explore both the biophysical mechanisms of animal magnetoreception and the possibility that weak, low-frequency anthropogenic electromagnetic fields may have biological consequences. In both cases, the presumed receptor is cryptochrome, a protein thought to be responsible for magnetic compass sensing in migratory birds and a variety of magnetic behavioural responses in insects. Here, we demonstrate that photo-induced electron transfer reactions in Drosophila melanogaster cryptochrome are indeed influenced by magnetic fields of a few millitesla. The form of the protein containing flavin and tryptophan radicals shows kinetics that differ markedly from those of closely related members of the cryptochrome-photolyase family. These differences and the magnetic sensitivity of Drosophila cryptochrome are interpreted in terms of the radical pair mechanism and a photocycle involving the recently discovered fourth tryptophan electron donor.

  15. Millitesla magnetic field effects on the photocycle of an animal cryptochrome (United States)

    Sheppard, Dean M. W.; Li, Jing; Henbest, Kevin B.; Neil, Simon R. T.; Maeda, Kiminori; Storey, Jonathan; Schleicher, Erik; Biskup, Till; Rodriguez, Ryan; Weber, Stefan; Hore, P. J.; Timmel, Christiane R.; Mackenzie, Stuart R.


    Drosophila have been used as model organisms to explore both the biophysical mechanisms of animal magnetoreception and the possibility that weak, low-frequency anthropogenic electromagnetic fields may have biological consequences. In both cases, the presumed receptor is cryptochrome, a protein thought to be responsible for magnetic compass sensing in migratory birds and a variety of magnetic behavioural responses in insects. Here, we demonstrate that photo-induced electron transfer reactions in Drosophila melanogaster cryptochrome are indeed influenced by magnetic fields of a few millitesla. The form of the protein containing flavin and tryptophan radicals shows kinetics that differ markedly from those of closely related members of the cryptochrome–photolyase family. These differences and the magnetic sensitivity of Drosophila cryptochrome are interpreted in terms of the radical pair mechanism and a photocycle involving the recently discovered fourth tryptophan electron donor. PMID:28176875

  16. The EF loop in green proteorhodopsin affects conformation and photocycle dynamics. (United States)

    Mehler, Michaela; Scholz, Frank; Ullrich, Sandra J; Mao, Jiafei; Braun, Markus; Brown, Lynda J; Brown, Richard C D; Fiedler, Sarah A; Becker-Baldus, Johanna; Wachtveitl, Josef; Glaubitz, Clemens


    The proteorhodopsin family consists of retinal proteins of marine bacterial origin with optical properties adjusted to their local environments. For green proteorhodopsin, a highly specific mutation in the EF loop, A178R, has been found to cause a surprisingly large redshift of 20 nm despite its distance from the chromophore. Here, we analyze structural and functional consequences of this EF loop mutation by time-resolved optical spectroscopy and solid-state NMR. We found that the primary photoreaction and the formation of the K-like photo intermediate is almost pH-independent and slower compared to the wild-type, whereas the decay of the K-intermediate is accelerated, suggesting structural changes within the counterion complex upon mutation. The photocycle is significantly elongated mainly due to an enlarged lifetime of late photo intermediates. Multidimensional MAS-NMR reveals mutation-induced chemical shift changes propagating from the EF loop to the chromophore binding pocket, whereas dynamic nuclear polarization-enhanced (13)C-double quantum MAS-NMR has been used to probe directly the retinylidene conformation. Our data show a modified interaction network between chromophore, Schiff base, and counterion complex explaining the altered optical and kinetic properties. In particular, the mutation-induced distorted structure in the EF loop weakens interactions, which help reorienting helix F during the reprotonation step explaining the slower photocycle. These data lead to the conclusion that the EF loop plays an important role in proton uptake from the cytoplasm but our data also reveal a clear interaction pathway between the EF loop and retinal binding pocket, which might be an evolutionary conserved communication pathway in retinal proteins.

  17. Structure and function in bacteriorhodopsin: the role of the interhelical loops in the folding and stability of bacteriorhodopsin. (United States)

    Kim, J M; Booth, P J; Allen, S J; Khorana, H G


    Bacteriorhodopsin functions as a light-driven proton pump in Halobacterium salinarium. The functional protein consists of an apoprotein, bacterioopsin, with seven transmembrane alpha helices together with a covalently bound all-trans retinal chromophore. In order to study the role of the interhelical loop conformations in the structure and function of bacteriorhodopsin, we have constructed bacterioopsin genes where each loop is replaced, one at a time, by a peptide linker consisting of Gly-Gly-Ser- repeat sequences, which are believed to have flexible conformations. These mutant proteins have been expressed in Escherichia coli, purified and reconstituted with all-trans retinal in l-alpha-1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)/3-(3-cholamidopropyl)dimethylammonio-1-propane sulfonate (CHAPS)/SDS and l-alpha-1,2-dihexanoylphosphatidylcholine (DHPC)/DMPC/SDS micelles. Wild-type-like chromophore formation was observed in all the mutants containing single loop replacements. In the BC and FG mutants, an additional chromophore band with an absorption band at about 480 nm was observed, which was in equilibrium with the 550 nm, wild-type band. The position of the equilibrium depended on temperature, SDS and relative DMPC concentration. The proton pumping activity of all of the mutants was comparable to that of wild-type bR except for the BC and FG mutants, which had lower activity. All of the loop mutants were more sensitive to denaturation by SDS than the wild-type protein, except the mutant where the DE loop was replaced. These results suggest that a specific conformation of all the loops of bR, except the DE loop, contributes to bR stability and is required for the correct folding and function of the protein. An increase in the relative proportion of DHPC in DHPC/DMPC micelles, which reduces the micelle rigidity and alters the micelle shape, resulted in lower folding yields of all loop mutants except the BC and DE mutants. This effect of micelle rigidity on

  18. Dynamic Behaviour of Self-Diffraction in Bacteriorhodopsin Film

    Institute of Scientific and Technical Information of China (English)

    GUO Zong-Xia; CHEN Gui-Ying; ZHANG Chun-Ping; TIAN Jian-Guo; Q. Wang Song; SHEN Bin; FU Guang-Hua


    @@ We investigate the dependences of the diffraction efficiency of the first order self-diffracted beam in bacteriorhodopsin (bR) films on the illumination time, the intensity and wavelength of the incident light. When the blue light (λ = 488 nm) and low intensity red light (λ = 632.8 nm) are incident on the bR film respectively,the diffraction efficiencies increase from zero to a stable value with the illumination time. When the green light (λ = 533 nm) and high-intensity red light illuminate the bR film respectively, the diffraction efficiencies increase from zero to the maximum and then decrease to a stable value with the illumination time. Rise and decay times are dependent on the intensity and wavelength of the incident light. The maximaldiffraction efficiency of the red light is twice as high as that of the green light. The highest diffraction efficiency of 5.4% is obtained at 633nm.The diffraction efficiency change with the time for the green light is larger than that for the blue and red light.

  19. Transient Fourier holography with bacteriorhodopsin films for breast cancer diagnostics (United States)

    Rao, Devulapalli; Kothapalli, Sri-Rajasekar; Wu, Pengfei; Yelleswarapu, Chandra

    X-ray mammography is the current gold standard for breast cancer screening. Microcalcifications and other features which are helpful to the radiologist for early diagnostics are often buried in the noise generated by the surrounding dense tissue. So image processing techniques are required to enhance these important features to improve the sensitivity of detection. An innovative technique is demonstrated for recording a hologram of the mammogram. It is recorded on a thin polymer film of Bacteriorhodopsin (bR) as photo induced isomerization grating containing the interference pattern between the object beam containing the Fourier spatial frequency components of the mammogram and a reference beam. The hologram contains all the enhanced features of the mammogram. A significant innovation of the technique is that the enhanced components in the processed image can be viewed by the radiologist in time scale. A technician can record the movie and when the radiologist looks at the movie at his convenience, freezing the frame as and when desired, he would see the microcalcifications as the brightest and last long in time. He would also observe lesions with intensity decreasing as their size increases. The same bR film can be used repeatedly for recording holograms with different mammograms. The technique is versatile and a different frequency band can be chosen to be optimized by changing the reference beam intensity. The experimental arrangement can be used for mammograms in screen film or digital format.

  20. Fundamentals of photoelectric effects in molecular electronic thin film devices: applications to bacteriorhodopsin-based devices. (United States)

    Hong, F T


    This tutorial lecture focuses on the fundamental mechanistic aspects of light-induced charge movements in pigment-containing membranes. The topic is relevant to molecular electronics because many prototypes optoelectronic devices are configured as pigment-containing thin films. We use reconstituted bacteriorhodopsin membranes as an example to illustrate the underlying principle of measurements and data interpretation. Bacteriorhodopsin, a light-driven proton pump, is the only protein component in the purple membrane of Halobacterium halobium. It resembles the visual pigment rhodopsin chemically but performs the function of photosynthesis. Bacteriorhodopsin thus offers an unprecedented opportunity for us to compare the visual photoreceptor and the photosynthetic apparatus from a mechanistic point of view. Bacteriorhodopsin, well known for its exceptional chemical and mechanical stability, is also a popular advanced biomaterial for molecular device construction. The tutorial approaches the subject from two angles. First, the fundamental photoelectric properties are exploited for device construction. Second, basic design principles for photosensors and photon energy converters can be elucidated via 'reverse engineering'. The concept of molecular intelligence and the principle of biomimetic science are discussed.

  1. Regiospecific Photocyclization of Mono- and Bis-Styryl-Substituted N-Heterocycles: A Synthesis of DNA-Binding Benzo[c]quinolizinium Derivatives. (United States)

    Aliyeu, Tseimur M; Berdnikova, Daria V; Fedorova, Olga A; Gulakova, Elena N; Stremmel, Christopher; Ihmels, Heiko


    Regiospecific C-N photocyclization of mono- and bis-styryl-substituted N-heterocycles was investigated. We demonstrated that the C-N regiospecificity of the photoinduced electrocyclization is a general feature of ortho-styryl-substituted N-heterocycles comprising one and two nitrogen atoms. This phototransformation provides a straightforward synthesis of the pharmaceutically important benzo[c]quinolizinium cation and its aza-analogues. Noticeably, bis-styryl derivatives undergo only one-fold cyclization with the second styryl fragment remaining uninvolved in the cyclization process. Photocyclization products of monostyryl derivativatives intercalate into calf thymus DNA (ct DNA), whereas photocyclization products of bis-styryl derivativatives possess a mixed binding mechanism with ct DNA. The results can be used for development of novel DNA-targeting chemotherapeutics based on benzo[c]quinolizinium derivatives.

  2. Chromophore dynamics in the PYP photocycle from femtosecond stimulated Raman spectroscopy. (United States)

    Creelman, Mark; Kumauchi, Masato; Hoff, Wouter D; Mathies, Richard A


    Femtosecond stimulated Raman spectroscopy (FSRS) is used to examine the structural dynamics of the para-hydroxycinnamic acid (HCA) chromophore during the first 300 ps of the photoactive yellow protein (PYP) photocycle, as the system transitions from its vertically excited state to the early ground state cis intermediate, I0. A downshift in both the C7═C8 and C1═O stretches upon photoexcitation reveals that the chromophore has shifted to an increasingly quinonic form in the excited state, indicating a charge shift from the phenolate moiety toward the C9═O carbonyl, which continues to increase for 170 fs. In addition, there is a downshift in the C9═O carbonyl out-of-plane vibration on an 800 fs time scale as PYP transitions from its excited state to I0, indicating that weakening of the hydrogen bond with Cys69 and out-of-plane rotation of the C9═O carbonyl are key steps leading to photoproduct formation. HOOP intensity increases on a 3 ps time scale during the formation of I0, signifying distortion about the C7═C8 bond. Once on the I0 surface, the C7═C8 and C1═O stretches blue shift, indicating recovery of charge to the phenolate, while persistent intensity in the HOOP and carbonyl out-of-plane modes reveal HCA to be a cissoid structure with significant distortion about the C7═C8 bond and of C9═O out of the molecular plane.

  3. Quantum yields for the light adaptations in Anabaena sensory rhodopsin and bacteriorhodopsin (United States)

    Wada, Yoichiro; Kawanabe, Akira; Furutani, Yuji; Kandori, Hideki; Ohtani, Hiroyuki


    Archael-type rhodopsin has an all- trans or a 13- cis retinal. The light-induced interconversion between these two forms has been found in Anabaena sensory rhodopsin, even though only the photoreaction from the 13- cis form to the all- trans form exists in bacteriorhodopsin. In this study, we obtained the quantum yields for the 13- cis → all- trans and all- trans → 13- cis reactions of Anabaena sensory rhodopsin (0.24 ± 0.03 and 0.38 ± 0.07, respectively) and concluded that these values were independent of the wavelength of the excitation light as well as bacteriorhodopsin. In other words, no excess energy effects can be found in these reactions.

  4. The 3rd-order nonlinearity of bacteriorhodopsin by four-wave mixing

    Institute of Scientific and Technical Information of China (English)


    The 3rd-order nonlinear optical susceptibility X(3) and the response time of the light-transducing biomolecule bacteriorhodopsin were measured with the four-wave mixing technique and a picosecond frequency-doubled Nd:YAG laser(532nm).The X(3) and the response time measured are 10-9 esu and 20 ps,respectively.The possible mechanism for generating the 3rd-order nonlinear optical susceptibility X(3) and response time were discussed.

  5. Theoretical and experimental analysis of pulse delay in bacteriorhodopsin films by a saturable absorber theory. (United States)

    Blaya, Salvador; Candela, Manuel; Acebal, Pablo; Carretero, Luis; Fimia, Antonio


    Time-delay of transmitted pulses with respect to the incident pulse in bacteriorhodopsin films has been studied without the use of a pump beam. Based on a modified saturable absorber model, analytical expressions of the transmitted pulse have been obtained. As a result, time delay, distortion and fractional delay have been analyzed for sinusoidal pulses with a low background. A good agreement between theory and experiences has been observed.

  6. A molecular movie at 1.8 A resolution displays the photocycle of photoactive yellow protein, a eubacterial blue-light receptor, from nanoseconds to seconds.

    NARCIS (Netherlands)

    Ren, Z.; Perman, B.; Srajer, V.; Teng, T.Y.; Pradervand, C.; Bourgeois, D.; Schotte, F.; Ursby, T.; Kort, R.


    The photocycle of the bacterial blue-light photoreceptor, photoactive yellow protein, was stimulated by illumination of single crystals by a 7 ns laser pulse. The molecular events were recorded at high resolution by time-resolved X-ray Laue diffraction as they evolved in real time, from 1 ns to seco

  7. Crystal structure of Escherichia coli-expressed Haloarcula marismortui bacteriorhodopsin I in the trimeric form.

    Directory of Open Access Journals (Sweden)

    Vitaly Shevchenko

    Full Text Available Bacteriorhodopsins are a large family of seven-helical transmembrane proteins that function as light-driven proton pumps. Here, we present the crystal structure of a new member of the family, Haloarcula marismortui bacteriorhodopsin I (HmBRI D94N mutant, at the resolution of 2.5 Å. While the HmBRI retinal-binding pocket and proton donor site are similar to those of other archaeal proton pumps, its proton release region is extended and contains additional water molecules. The protein's fold is reinforced by three novel inter-helical hydrogen bonds, two of which result from double substitutions relative to Halobacterium salinarum bacteriorhodopsin and other similar proteins. Despite the expression in Escherichia coli and consequent absence of native lipids, the protein assembles as a trimer in crystals. The unique extended loop between the helices D and E of HmBRI makes contacts with the adjacent protomer and appears to stabilize the interface. Many lipidic hydrophobic tail groups are discernible in the membrane region, and their positions are similar to those of archaeal isoprenoid lipids in the crystals of other proton pumps, isolated from native or native-like sources. All these features might explain the HmBRI properties and establish the protein as a novel model for the microbial rhodopsin proton pumping studies.

  8. Crystal structure of Escherichia coli-expressed Haloarcula marismortui bacteriorhodopsin I in the trimeric form. (United States)

    Shevchenko, Vitaly; Gushchin, Ivan; Polovinkin, Vitaly; Round, Ekaterina; Borshchevskiy, Valentin; Utrobin, Petr; Popov, Alexander; Balandin, Taras; Büldt, Georg; Gordeliy, Valentin


    Bacteriorhodopsins are a large family of seven-helical transmembrane proteins that function as light-driven proton pumps. Here, we present the crystal structure of a new member of the family, Haloarcula marismortui bacteriorhodopsin I (HmBRI) D94N mutant, at the resolution of 2.5 Å. While the HmBRI retinal-binding pocket and proton donor site are similar to those of other archaeal proton pumps, its proton release region is extended and contains additional water molecules. The protein's fold is reinforced by three novel inter-helical hydrogen bonds, two of which result from double substitutions relative to Halobacterium salinarum bacteriorhodopsin and other similar proteins. Despite the expression in Escherichia coli and consequent absence of native lipids, the protein assembles as a trimer in crystals. The unique extended loop between the helices D and E of HmBRI makes contacts with the adjacent protomer and appears to stabilize the interface. Many lipidic hydrophobic tail groups are discernible in the membrane region, and their positions are similar to those of archaeal isoprenoid lipids in the crystals of other proton pumps, isolated from native or native-like sources. All these features might explain the HmBRI properties and establish the protein as a novel model for the microbial rhodopsin proton pumping studies.

  9. Femtosecond spectroscopic study of photochromic reactions of bacteriorhodopsin and visual rhodopsin. (United States)

    Feldman, Tatiana B; Smitienko, Olga A; Shelaev, Ivan V; Gostev, Fedor E; Nekrasova, Oksana V; Dolgikh, Dmitriy A; Nadtochenko, Victor A; Kirpichnikov, Mikhail P; Ostrovsky, Mikhail A


    Photochromic ultrafast reactions of bacteriorhodopsin (H. salinarum) and bovine rhodopsin were conducted with a femtosecond two-pump probe pulse setup with the time resolution of 20-25fs. The dynamics of the forward and reverse photochemical reactions for both retinal-containing proteins was compared. It is demonstrated that when retinal-containing proteins are excited by femtosecond pulses, dynamics pattern of the vibrational coherent wave packets in the course of the reaction is different for bacteriorhodopsin and visual rhodopsin. As shown in these studies, the low-frequencies that form a wave packets experimentally observed in the dynamics of primary products formation as a result of retinal photoisomerization have different intensities and are clearer for bovine rhodopsin. Photo-reversible reactions for both retinal proteins were performed from the stage of the relatively stable photointermediates that appear within 3-5ps after the light pulse impact. It is demonstrated that the efficiency of the reverse phototransition K-form→bacteriorhodopsin is almost five-fold higher than that of the Batho-intermediate→visual rhodopsin phototransition. The results obtained indicate that in the course of evolution the intramolecular mechanism of the chromophore-protein interaction in visual rhodopsin becomes more perfect and specific. The decrease in the probability of the reverse chromophore photoisomerization (all-trans→11-cis retinal) in primary photo-induced rhodopsin products causes an increase in the efficiency of the photoreception process.

  10. Two-photon polarization data storage in bacteriorhodopsin films and its potential use in security applications (United States)

    Imhof, Martin; Rhinow, Daniel; Hampp, Norbert


    Bacteriorhodopsin (BR) films allow write-once-read-many recording of polarization data by a two-photon-absorption (TPA) process. The optical changes in BR films induced by the TPA recording were measured and the Müller matrix of a BR film was determined. A potential application of BR films in security technology is shown. Polarization data can be angle-selective retrieved with high signal-to-noise ratio. The BR film does not only carry optical information but serves also as a linear polarizer. This enables that polarization features recorded in BR films may be retrieved by merely using polarized light from a mobile phone display.

  11. Pathways of proton transfer in the light-driven pump bacteriorhodopsin (United States)

    Lanyi, J. K.


    The mechanism of proton transport in the light-driven pump bacteriorhodopsin is beginning to be understood. Light causes the all-trans to 13-cis isomerization of the retinal chromophore. This sets off a sequential and directed series of transient decreases in the pKa's of a) the retinal Schiff base, b) an extracellular proton release complex which includes asp-85, and c) a cytoplasmic proton uptake complex which includes asp-96. The timing of these pKa changes during the photoreaction cycle causes sequential proton transfers which result in the net movement of a proton across the protein, from the cytoplasmic to the extracellular surface.

  12. Photoelectrochemical Properties of Bacteriorhodopsin Langmuir-Blodgett Films on ITO Conductive Electrode

    Institute of Scientific and Technical Information of China (English)

    王建平; 李津如; 陶培德; 李兴长; 江龙


    Langmuir-Blodgett films containing bacteriorhodopsin were deposited on ITO conduc-tive electrodes.A sandwiched photocell with a junction structure of ITO/bR/electrolyte/ITO has beenconstructed,in which the bR LB film was directly put into contact with an aqueous electrolyte immobi-lized in an agar gel.Under visible light irradiation,the photocell produced a transient photocurrent due tothe change of light intensity,which characterized vision imitative material.A photoalarm device based ondifferential responsivity phenomena was fabricated.

  13. Two-photon polarization data storage in bacteriorhodopsin films and its potential use in security applications

    Energy Technology Data Exchange (ETDEWEB)

    Imhof, Martin; Hampp, Norbert, E-mail: [Department of Chemistry, Material Sciences Center, University of Marburg, Hans-Meerwein-Str., D-35032 Marburg (Germany); Rhinow, Daniel [Max-Planck-Institute of Biophysics, Max-von-Laue-Straße 3, D-60438 Frankfurt (Germany)


    Bacteriorhodopsin (BR) films allow write-once-read-many recording of polarization data by a two-photon-absorption (TPA) process. The optical changes in BR films induced by the TPA recording were measured and the Müller matrix of a BR film was determined. A potential application of BR films in security technology is shown. Polarization data can be angle-selective retrieved with high signal-to-noise ratio. The BR film does not only carry optical information but serves also as a linear polarizer. This enables that polarization features recorded in BR films may be retrieved by merely using polarized light from a mobile phone display.

  14. Resonance Raman kinetic spectroscopy of bacteriorhodopsin on the microsecond time scale

    Energy Technology Data Exchange (ETDEWEB)

    Campion, A.; El-Sayed, M.A.; Terner, J.


    Using a rotating disk with a slit of variable width, a continuous wave argon ion laser, and an Optical Multichanel Analyzer for detection, a new technique is reported which should, in principle, be capable of recording resonance Raman spectra with time resolution of 100 ns. The resonance Raman spectra of the intermediates of the photosynthetic cycle of bacteriorhodopsin are recorded on the microsecond time scale. Both the kinetic results and the resonance enhancement profile suggest that deprotonation results in an intermediate preceding bM/sub 412/ that has an optical absorption maximum at a wavelength longer than that of bM/sub 412/.

  15. Enhancement of photoelectric response of bacteriorhodopsin by multilayered WO3 x H2O nanocrystals/PVA membrane. (United States)

    Li, Rui; Hu, Fengping; Bao, Qiaoliang; Bao, Shujuan; Qiao, Yan; Yu, Shucong; Guo, Jun; Li, Chang Ming


    For the first time, a multilayered WO(3) x H(2)O/PVA membrane on bacteriorhodopsin (bR) is constructed to significantly enhance the photoelectric response of bR by the spillover effect of WO(3) x H(2)O nanocrystals, providing great potential in its important applications in bioelectronics and proton exchange membrane fuel cells.

  16. New Nano- and Biotechnological Applications of Bacterial and Animal Photoreceptor Pigments  Bacteriorhodopsin, Rhodopsin and Iodopsin

    Directory of Open Access Journals (Sweden)

    Ignat Ignatov


    Full Text Available This paper views predominately the structure and function of animal and bacterial photoreceptor pigments (rhodopsin, iodopsin, bacteriorhodopsin and new aspects of their nano- and biotechnological usage. On an example of bacteriorhodopsin was described the method of its isolation from purple membranes of photo-organotrophic halobacterium Halobacterium halobium by cellular autolysis by distilled water, processing of bacterial biomass by ultrasound at 22 KHz, alcohol extraction of low and high-weight molecular impurities, cellular RNA, carotenoids and lipids, the solubilization with 0,5 % (w/v SDS-Na and subsequent fractionation by methanol and gel filtration chromatography on Sephadex G-200 Column balanced with 0.09 M Tris-HCl buffer (pH = 6,76 with 0,1 % (w/v SDS-Na and 2,5 mM EDTA. Within the framework of the research the mechanism of color perception by the visual analyzer having the ability to analyze certain ranges of the optical spectrum, as colors was studied along with an analysis of the additive mixing of two colors. It was shown that at the mixing of electromagnetic waves with different wavelengths, the visual analyzer perceive them as separate or average wave length corresponding to mix color.

  17. Studying of Phototransformation of Light Signal by Photoreceptor Pigments - Rhodopsin, Iodopsin and Bacteriorhodopsin

    Directory of Open Access Journals (Sweden)

    Ignat Ignatov


    Full Text Available This review article views predominately the structure and function of animal and bacterial photoreceptor pigments (rhodopsin, iodopsin, bacteriorhodopsin and their aspects of nano- and biotechnological usage. On an example of bacteriorhodopsin is described the method of its isolation from purple membranes of photo-organotrophic halobacterium Halobacterium halobium by cellular autolysis by distilled water, processing of bacterial biomass by ultrasound at 22 KHz, alcohol extraction of low and high-weight molecular impurities, cellular RNA, carotenoids and lipids, the solubilization with 0,5 % (w/v SDS-Na and subsequent fractionation by methanol and gel filtration chromatography on Sephadex G-200 Column balanced with 0.09 M Tris-borate buffer (pH = 8,35 with 0,1 % (w/v SDS-Na and 2,5 mM EDTA. Within the framework of the research the mechanism of color perception by the visual analyzer having the ability to analyze certain ranges of the optical spectrum, as colors was studied along with an analysis of the additive mixing of two colors. It was shown that at the mixing of electromagnetic waves with different wavelengths, the visual analyzer perceive them as separate or average wave length corresponding to mix color.

  18. Excited-state dynamics of bacteriorhodopsin probed by broadband femtosecond fluorescence spectroscopy. (United States)

    Schmidt, B; Sobotta, C; Heinz, B; Laimgruber, S; Braun, M; Gilch, P


    The impact of varying excitation densities (approximately 0.3 to approximately 40 photons per molecule) on the ultrafast fluorescence dynamics of bacteriorhodopsin has been studied in a wide spectral range (630-900 nm). For low excitation densities, the fluorescence dynamics can be approximated biexponentially with time constants of <0.15 and approximately 0.45 ps. The spectrum associated with the fastest time constant peaks at 650 nm, while the 0.45 ps component is most prominent at 750 nm. Superimposed on these kinetics is a shift of the fluorescence maximum with time (dynamic Stokes shift). Higher excitation densities alter the time constants and their amplitudes. These changes are assigned to multi-photon absorptions.

  19. An Approach to Heterologous Expression of Membrane Proteins. The Case of Bacteriorhodopsin. (United States)

    Bratanov, Dmitry; Balandin, Taras; Round, Ekaterina; Shevchenko, Vitaly; Gushchin, Ivan; Polovinkin, Vitaly; Borshchevskiy, Valentin; Gordeliy, Valentin


    Heterologous overexpression of functional membrane proteins is a major bottleneck of structural biology. Bacteriorhodopsin from Halobium salinarum (bR) is a striking example of the difficulties in membrane protein overexpression. We suggest a general approach with a finite number of steps which allows one to localize the underlying problem of poor expression of a membrane protein using bR as an example. Our approach is based on constructing chimeric proteins comprising parts of a protein of interest and complementary parts of a homologous protein demonstrating advantageous expression. This complementary protein approach allowed us to increase bR expression by two orders of magnitude through the introduction of two silent mutations into bR coding DNA. For the first time the high quality crystals of bR expressed in E. Coli were obtained using the produced protein. The crystals obtained with in meso nanovolume crystallization diffracted to 1.67 Å.

  20. An Approach to Heterologous Expression of Membrane Proteins. The Case of Bacteriorhodopsin.

    Directory of Open Access Journals (Sweden)

    Dmitry Bratanov

    Full Text Available Heterologous overexpression of functional membrane proteins is a major bottleneck of structural biology. Bacteriorhodopsin from Halobium salinarum (bR is a striking example of the difficulties in membrane protein overexpression. We suggest a general approach with a finite number of steps which allows one to localize the underlying problem of poor expression of a membrane protein using bR as an example. Our approach is based on constructing chimeric proteins comprising parts of a protein of interest and complementary parts of a homologous protein demonstrating advantageous expression. This complementary protein approach allowed us to increase bR expression by two orders of magnitude through the introduction of two silent mutations into bR coding DNA. For the first time the high quality crystals of bR expressed in E. Coli were obtained using the produced protein. The crystals obtained with in meso nanovolume crystallization diffracted to 1.67 Å.

  1. Calibration of Membrane Viscosity of the Reconstituted Vesicles by Measurement of the Rotational Diffusion of Bacteriorhodopsin

    Institute of Scientific and Technical Information of China (English)

    王敖金; 胡坤生


    Membrane viscosity of the reconstituted vesicles was calibrated by rotational diffusion of bacteriorhodopsin (BR) in dimyristoylphosphatidylcholine (DMPC) and egg phosphatidylcholine (PC) vesicles. Rotational diffusion of BR in the vesicles was measured by flash-induced absorption anisotropy decay. BR was, for the first time, reconstituted successfully into DMPC and egg PC vesicles. From the measurement of flash-induced absorption anisotropy decay of BR, the value of rotational diffusion coefficient D was obtained from each curve fitting by a global fitting procedure and, in turn, membrane viscosity η was estimated from D. The results have shown that membrane viscosity is temperature-dependent. It was decreased as temperature increased, but a transition occurred in the region of the respective phase transition of DMPC and egg PC, respectively. The decrease of η was fast near the phase transition for DMPC and egg PC. Few effects of lipid/BR ratio and glycerol or sucrose in suspension medium on membrane viscosity were found.

  2. An all-optical time-delay relay based n a bacteriorhodopsin film

    Institute of Scientific and Technical Information of China (English)

    Chen Gui-Ying; Xu Xu-Xu; Zhang Chun-Ping; Qi Shen-Wen; Song Qi-Wang


    Using a special property of dynamic complementary-suppression-modulated transmission (DCSMT) in the bacteriorhodopsin (bR) film,we have demonstrated an all-optical time-delay relay.To extend our work,the relationship between the delay time of the all-optical time-delay relay and parameters of a bR film is numerically studied.We show how the delay time changes with the product of concentration and thickness (PCT) of a bR film.Furthermore,the shortest and longest delay times are given for the relay of 'switch off'.The saturable delay time and maximum delaytime of 'switch on' are also given.How the wavelengths (632.8,568,533 and 412 nm) and intensities of the illuminating light influence the delay time is also discussed.The simulation results are useful for optimizing the design of all-optical time-delay relays.

  3. Spatio-temporal study of non-degenerate two-wave mixing in bacteriorhodopsin films. (United States)

    Blaya, Salvador; González, Alejandro; Acebal, Pablo; Carretero, Luis


    A spatio-temporal analysis of non-degenerate two-wave mixing in a saturable absorber, such as bacteriorhodopsin (bR) film, is performed. To do this, a theoretical model describing the temporal variation of the intensities is developed by taking into account the dielectric constant as a function of bR population. A good agreement between theory and experimental measurements is obtained. Thus, the dependence of the optical gain and the main dielectric constant parameters are studied at different intensities and frequencies. As a result, the best intensity-frequency zones where higher coupling is reached are proposed, and it is also demonstrated that non-uniform patterns, which evolve over time as a function of frequency difference, can be observed.

  4. Rigorous analysis of the propagation of sinusoidal pulses in bacteriorhodopsin films. (United States)

    Acebal, Pablo; Blaya, Salvador; Carretero, Luis; Madrigal, R F; Fimia, A


    The propagation of sinusoidal pulses in bacteriorhodopsin films has been theoretically analyzed using a complete study of the photoinduced processes that take into account all the physical parameters, the coupling of rate equations with the energy transfer equation and the temperature change during the experiment. The theoretical approach was compared to experimental data and a good concordance was observed. This theoretical treatment, can be widely applied, i.e when arbitrary pump and/or signal is used or in the case of the pump and signal beams have different wavelengths. Due to we have performed a rigorous analysis, from this treatment the corresponding two level approximation has also been analyzed for these systems.

  5. Development of bacteriorhodopsin analogues and studies of charge separated excited states in the photoprocesses of linear polyenes. (United States)

    Singh, Anil K; Hota, Prasanta K


    Development of bacteriorhodopsin (bR) analogues employing chromophore substitution technique for the purpose of characterizing the binding site of bR and generating bR analogues with novel opto-electronic properties for applications as photoactive element in nanotechnical devices are described. Additionally, the photophysical and photochemical properties of variously substituted diarylpolyenes as models of photobiologically relevant linear polyenes are discussed. The role of charge separated dipolar excited states in the photoprocesses of linear polyenes is highlighted.

  6. Modulation of folding and assembly of the membrane protein bacteriorhodopsin by intermolecular forces within the lipid bilayer. (United States)

    Curran, A R; Templer, R H; Booth, P J


    Three different lipid systems have been developed to investigate the effect of physicochemical forces within the lipid bilayer on the folding of the integral membrane protein bacteriorhodopsin. Each system consists of lipid vesicles containing two lipid species, one with phosphatidylcholine and the other with phosphatidylethanolamine headgroups, but the same hydrocarbon chains: either L-alpha-1, 2-dioleoyl, L-alpha-1,2-dipalmitoleoyl, or L-alpha-1,2-dimyristoyl. Increasing the mole fraction of the phosphatidylethanolamine lipid increases the desire of each monolayer leaflet in the bilayer to curve toward water. This increases the torque tension of such monolayers, when they are constrained to remain flat in the vesicle bilayer. Consequently, the lateral pressure in the hydrocarbon chain region increases, and we have used excimer fluorescence from pyrene-labeled phosphatidylcholine lipids to probe these pressure changes. We show that bacteriorhodopsin regenerates to about 95% yield in vesicles of 100% phosphatidylcholine. The regeneration yield decreases as the mole fraction of the corresponding phosphatidylethanolamine component is increased. The decrease in yield correlates with the increase in lateral pressure which the lipid chains exert on the refolding protein. We suggest that the increase in lipid chain pressure either hinders insertion of the denatured state of bacterioopsin into the bilayer or slows a folding step within the bilayer, to the extent that an intermediate involved in bacteriorhodopsin regeneration is effectively trapped.

  7. Studying proton pumping mechanism of bacteriorhodopsin and cytochrome c oxidase with multi-conformation continuum electrostatics (United States)

    Song, Yifan

    The proton gradient across the biological membrane is important for the biological systems. Bacteriorhodopsin and cytochrome c oxidase convert different energy sources into this gradient. The focus of this thesis is to understand the mechanism of these proteins using computational methods. In bacteriorhodopsin, residue ionization states were calculated in 9 crystal structures trapped in bR, early M and late M states by Multi-Conformation Continuum Electrostatics (MCC). The three groups in the central cluster are ionized in bR structures while a proton has transferred from the SB+ to Asp 85 - in the late M structures matching prior experimental results. The proton release cluster binds one proton in bR structure which is lost to water by pH 8 in late M. Modest changes in intra-protein interactions cause the charge shifts within the clusters. Motions of Arg 82 couple the proton shift in the central cluster to proton release. Changes in the total charge of the two clusters are coupled by direct long-range interactions. Cytochrome c oxidase is a transmembrane proton pump that builds an electrochemical gradient using chemical energy from the reduction of O2. Ionization states of all residues were calculated with MCCE in seven anaerobic oxidase redox states ranging from fully oxidized to fully reduced in Rb. sphaeroides cytochrome c oxidase. At pH 7, only a hydroxide coordinated to CuB shifts its pKa from below 7 to above 7, and so picks up a proton when Heme a3 and CuB are reduced. Glu I-286, Tyr I-288, His I-334 and a second hydroxide on Heme a3 all have pKas above 7. The propionic acids near the BNC are deprotonated with pKas well below 7. This suggests electroneutrality in the BNC is not maintained during the anaerobic reduction. The electrochemical midpoint potential (E m) of Heme a is calculated to shift down when the BNC is reduced, which agrees with prior experiments. If the BNC reduction is electroneutral, then the Heme a Em is independent of the BNC redox state.

  8. Effective atomic numbers and electron densities of bacteriorhodopsin and its comprising amino acids in the energy range 1 keV-100 GeV (United States)

    Ahmadi, Morteza; Lunscher, Nolan; Yeow, John T. W.


    Recently, there has been an interest in fabrication of X-ray sensors based on bacteriorhodopsin, a proton pump protein in cell membrane of Halobacterium salinarium. Therefore, a better understanding of interaction of X-ray photons with bacteriorhodopsin is required. We use WinXCom program to calculate the mass attenuation coefficient of bacteriorhodopsin and its comprising amino acids for photon energies from 1 keV to 100 GeV. These amino acids include alanine, arginine, asparagine, aspartic acid, glutamine, glutamic acid, glycine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, Asx1, Asx2, Glx1 and Glx2. We then use that data to calculate effective atomic number and electron densities for the same range of energy. We also emphasize on two ranges of energies (10-200 keV and 1-20 MeV) in which X-ray imaging and radiotherapy machines work.

  9. Effective atomic numbers and electron densities of bacteriorhodopsin and its comprising amino acids in the energy range 1 keV–100 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadi, Morteza; Lunscher, Nolan [Waterloo Institute for Nanotechnology and Department of Systems Design Engineering, University of Waterloo, 200 University Ave., W., Waterloo, Ontario, Canada N2L 3G1 (Canada); Yeow, John T.W., E-mail: [Waterloo Institute for Nanotechnology and Department of Systems Design Engineering, University of Waterloo, 200 University Ave., W., Waterloo, Ontario, Canada N2L 3G1 (Canada)


    Recently, there has been an interest in fabrication of X-ray sensors based on bacteriorhodopsin, a proton pump protein in cell membrane of Halobacterium salinarium. Therefore, a better understanding of interaction of X-ray photons with bacteriorhodopsin is required. We use WinXCom program to calculate the mass attenuation coefficient of bacteriorhodopsin and its comprising amino acids for photon energies from 1 keV to 100 GeV. These amino acids include alanine, arginine, asparagine, aspartic acid, glutamine, glutamic acid, glycine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, Asx1, Asx2, Glx1 and Glx2. We then use that data to calculate effective atomic number and electron densities for the same range of energy. We also emphasize on two ranges of energies (10–200 keV and 1–20 MeV) in which X-ray imaging and radiotherapy machines work.

  10. Deposition of Bacteriorhodopsin Protein in a Purple Membrane Form on Nitrocellulose Membranes for Enhanced Photoelectric Response

    Directory of Open Access Journals (Sweden)

    Chang-Hoon Nam


    Full Text Available Bacteriorhodopsin protein (bR-based systems are one of the simplest known biological energy converters. The robust chemical, thermal and electrochemical properties of bR have made it an attractive material for photoelectric devices. This study demonstrates the photoelectric response of a dry bR layer deposited on a nitrocellulose membrane with indium tin oxide (ITO electrodes. Light-induced electrical current as well as potential and impedance changes of dried bR film were recorded as the function of illumination. We have also tested bR in solution and found that the electrical properties are strongly dependent on light intensity changing locally proton concentration and thus pH of the solution. Experimental data support the assumption that bR protein on a positively charged nitrocellulose membrane (PNM can be used as highly sensitive photo- and pH detector. Here the bR layer facilitates proton translocation and acts as an ultrafast optoelectric signal transducer. It is therefore useful in applications related to bioelectronics, biosensors, bio-optics devices and current carrying junction devices.

  11. Nanoparticle surface-enhanced Raman scattering of bacteriorhodopsin stabilized by amphipol A8-35. (United States)

    Polovinkin, V; Balandin, T; Volkov, O; Round, E; Borshchevskiy, V; Utrobin, P; von Stetten, D; Royant, A; Willbold, D; Arzumanyan, G; Chupin, V; Popot, J-L; Gordeliy, V


    Surface-enhanced Raman spectroscopy (SERS) has developed dramatically since its discovery in the 1970s, because of its power as an analytical tool for selective sensing of molecules adsorbed onto noble metal nanoparticles (NPs) and nanostructures, including at the single-molecule (SM) level. Despite the high importance of membrane proteins (MPs), SERS application to MPs has not really been studied, due to the great handling difficulties resulting from the amphiphilic nature of MPs. The ability of amphipols (APols) to trap MPs and keep them soluble, stable, and functional opens up onto highly interesting applications for SERS studies, possibly at the SM level. This seems to be feasible since single APol-trapped MPs can fit into gaps between noble metal NPs, or in other gap-containing SERS substrates, whereby the enhancement of Raman scattering signal may be sufficient for SM sensitivity. The goal of the present study is to give a proof of concept of SERS with APol-stabilized MPs, using bacteriorhodopsin (BR) as a model. BR trapped by APol A8-35 remains functional even after partial drying at a low humidity. A dried mixture of silver Lee-Meisel colloid NPs and BR/A8-35 complexes give rise to SERS with an average enhancement factor in excess of 10(2). SERS spectra resemble non-SERS spectra of a dried sample of BR/APol complexes.

  12. Enhanced Photocurrent Generation from Bacteriorhodopsin Photocells Using Grating-Structured Transparent Conductive Oxide Electrodes. (United States)

    Kaji, Takahiro; Kasai, Katsuyuki; Haruyama, Yoshihiro; Yamada, Toshiki; Inoue, Shin-Ichiro; Tominari, Yukihiro; Ueda, Rieko; Terui, Toshifumi; Tanaka, Shukichi; Otomo, Akira


    We fabricated a grating-structured electrode made of indium-doped zinc oxide (IZO) with a high refractive index (approximately 2) for a bacteriorhodopsin (bR) photocell. We investigated the photocurrent characteristics of the bR photocell and demonstrated that the photocurrent values from the bR/IZO electrode with the grating structure with a grating period of 340 nm were more than 3.5-4 times larger than those without the grating structure. The photocurrent enhancement was attributed to the resonance effect due to light coupling to the grating structure as well as the scattering effect based on the experimental results and analysis using the photonic band structure determined using finite-difference time-domain (FDTD) simulations. The refractive index of the bR film in electrolyte solution (1.40) used in the FDTD simulations was estimated by analyzing the extinction peak wavelength of 20-nm gold colloids in the bR film. Our results indicate that the grating- or photonic-crystal-structured transparent conductive oxide (TCO) electrodes can increase the light use efficiency of various bR devices such as artificial photosynthetic devices, solar cells, and light-sensing devices.

  13. Resonant transfer of one- and two-photon excitations in quantum dot-bacteriorhodopsin complexes (United States)

    Krivenkov, V. A.; Samokhvalov, P. S.; Bilan, R. S.; Chistyakov, A. A.; Nabiev, I. R.


    Light-sensitive protein bacteriorhodopsin (BR), which is capable of electrical response upon exposure to light, is a promising material for photovoltaics and optoelectronics. However, the rather narrow absorption spectrum of BR does not allow achieving efficient conversion of the light energy in the blue and infrared spectral regions. This paper summarizes the results of studies showing the possibility of extending the spectral region of the BR function by means of the Förster resonance energy transfer (FRET) from CdSe/ZnS quantum dots (QDs), which have a broad spectrum of one-photon absorption and a large twophoton absorption cross section (TPACS), to BR upon one- and two-photon excitation. In particular, it is shown that, on the basis of QDs and BR-containing purple membranes, it is possible to create electrostatically associated bio-nano hybrid systems in which FRET is implemented. In addition, the large TPACS of QDs, which is two orders of magnitude larger than those of BR and organic dyes, opens up a means for selective two-photon excitation of synthesized bio-nano hybrid complexes. On the basis of the results of this work, the spectral region in which BR converts the light energy into electrical energy can be extended from the UV to near-IR region, creating new opportunities for the use of this material in photovoltaics and optoelectronics.

  14. Deposition of bacteriorhodopsin protein in a purple membrane form on nitrocellulose membranes for enhanced photoelectric response. (United States)

    Kim, Young Jun; Neuzil, Pavel; Nam, Chang-Hoon; Engelhard, Martin


    Bacteriorhodopsin protein (bR)-based systems are one of the simplest known biological energy converters. The robust chemical, thermal and electrochemical properties of bR have made it an attractive material for photoelectric devices. This study demonstrates the photoelectric response of a dry bR layer deposited on a nitrocellulose membrane with indium tin oxide (ITO) electrodes. Light-induced electrical current as well as potential and impedance changes of dried bR film were recorded as the function of illumination. We have also tested bR in solution and found that the electrical properties are strongly dependent on light intensity changing locally proton concentration and thus pH of the solution. Experimental data support the assumption that bR protein on a positively charged nitrocellulose membrane (PNM) can be used as highly sensitive photo- and pH detector. Here the bR layer facilitates proton translocation and acts as an ultrafast optoelectric signal transducer. It is therefore useful in applications related to bioelectronics, biosensors, bio-optics devices and current carrying junction devices.

  15. Photosensory behaviour of a bacteriorhodopsin-deficient mutant, ET-15, of Halobacterium halobium

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrand, E.; Schimz, A. (Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Neurobiologie)


    Halobacterium halobium, strain ET-15, which does not contain detectable amounts of bacteriorhodopsin (BR) shows behavioral responses to UV and yellow-green light. Attractant stimuli, i.e. light-increases in the yellow-green range or light-decreases in the UV, suppress the spontaneous reversals of the swimming direction for a certain time. Repellent stimuli, i.e. light-decreases in the yellow-green range or light-increases in the UV, elicit an additional reversal response after a few seconds. Action spectra of both sensory photosystems, PS 370 and PS 565, were measured with attractant as well as with repellent stimuli. As in BR-containing cells, maximal sensitivity was always found at 370 nm for the UV-system and at 565 nm for the long-wavelength system. Fluence-response curves at 370 and 565 nm obtained with strain ET-15 and with a BR-containing strain show that the sensitivity of both photosystems is not reduced in the absence of BR. It is concluded that BR is required neither for PS 565 nor for PS 370. Instead retinal-containing pigments different from BR have to be assumed to mediate photosensory behavior.

  16. Förster Resonance Energy Transfer between Core/Shell Quantum Dots and Bacteriorhodopsin

    Directory of Open Access Journals (Sweden)

    Mark H. Griep


    Full Text Available An energy transfer relationship between core-shell CdSe/ZnS quantum dots (QDs and the optical protein bacteriorhodopsin (bR is shown, demonstrating a distance-dependent energy transfer with 88.2% and 51.1% of the QD energy being transferred to the bR monomer at separation distances of 3.5 nm and 8.5 nm, respectively. Fluorescence lifetime measurements isolate nonradiative energy transfer, other than optical absorptive mechanisms, with the effective QD excited state lifetime reducing from 18.0 ns to 13.3 ns with bR integration, demonstrating the Förster resonance energy transfer contributes to 26.1% of the transferred QD energy at the 3.5 nm separation distance. The established direct energy transfer mechanism holds the potential to enhance the bR spectral range and sensitivity of energies that the protein can utilize, increasing its subsequent photocurrent generation, a significant potential expansion of the applicability of bR in solar cell, biosensing, biocomputing, optoelectronic, and imaging technologies.

  17. Structural analysis of bacteriorhodopsin solubilized by lipid-like phosphocholine biosurfactants with varying micelle concentrations. (United States)

    Wang, Xiaoqiang; Huang, Haihong; Sun, Chenghao; Huang, Fang


    Surfactants that can provide a more natural substitute for lipid bilayers are important in the purification and in vitro study of membrane proteins. Here we investigate the structural response of a model membrane protein, bacteriorhodopsin (BR), to phosphocholine biosurfactants. Phosphocholine biosurfactants are a type of biomimetic amphiphile that are similar to phospholipids, in which membrane proteins are commonly embedded. Multiple spectroscopic and zeta potential measurements are employed to characterize the conformational change, secondary and tertiary structure, oligomeric status, surface charge distribution and the structural stability of BR solubilized with phosphocholine biosurfactants of varying tail length. The process of phosphocholine micelle formation is found to facilitate the solubilization of BR, and for long-chain phosphocholines, concentrations much higher than their critical micelle concentrations achieve good solubilization. Phosphocholine biosurfactants are shown to be mild compared with the ionic surfactant SDS or CTAB, and tend to preserve membrane protein structure during solubilization, especially at low micelle concentrations, by virtue of their phospholipid-like zwitterionic head groups. The increase of alkyl chain length is shown to obviously enhance the capability of phosphocholine biosurfactants to stabilize BR. The underlying mechanism for the favorable actions of phosphocholine biosurfactant is also discussed.

  18. Charge-controlled assembling of bacteriorhodopsin and semiconductor quantum dots for fluorescence resonance energy transfer-based nanophotonic applications (United States)

    Bouchonville, Nicolas; Molinari, Michael; Sukhanova, Alyona; Artemyev, Mikhail; Oleinikov, Vladimir A.; Troyon, Michel; Nabiev, Igor


    The fluorescence resonance energy transfer (FRET) between quantum dots (QDs) and photochromic protein bacteriorhodopsin within its natural purple membrane (PM) is explored to monitor their assembling. It is shown that the efficiency of FRET may be controlled by variation of the surface charge and thickness of QD organic coating. Atomic force microscopy imaging revealed correlation between the surface charge of QDs and degree of their ordering on the surface of PM. The most FRET-efficient QD-PM complexes have the highest level of QDs ordering, and their assembling design may be further optimized to engineer hybrid materials with advanced biophotonic and photovoltaic properties.

  19. cis-4,4'-stilbenediols. Synthesis from dienestrol, structure, and photocyclization to dihydrophenanthrenes. [Diels-Adler reaction of estrogenic hormone dienestrol with various dienophiles

    Energy Technology Data Exchange (ETDEWEB)

    Maienthal, M. (Food and Drug Administration, Washington, DC); Benson, W.R.; Sheninin, E.B.; Doyle, T.D.; Filipescu, N.


    Diels--Alder cycloaddition reactions between dienestrol or its diacetate and dienophiles maleic anhydride, 4-phenyl-1,2,4-triazoline-3,5-dione, dimethyl maleate, 1,4-naphthoquinone, and tetracyanoethylene yielded adducts representing 4,4'-stilbenediols with obligate cis configuration. These compounds are ideally suited for studying the photochemical conversion of stilbene-like molecules to dihydrophenanthrenes without interference from the trans-stilbene isomers. The structures and stereochemistry of the Diels--Alder adducts were established by detailed interpretation of their NMR and mass spectra. UV irradiation of the synthesized cis-stilbenes caused photocyclization to the respective 4a,4b-dihydrophenanthrenes without interfering side reactions and with quantum yields in excess of 0.85.

  20. Light pulses do not induce c-fos or per1 in the SCN of hamsters that fail to reentrain to the photocycle. (United States)

    Barakat, Monique T; O'Hara, Bruce F; Cao, Vinh H; Larkin, Jennie E; Heller, H Craig; Ruby, Norman F


    Circadian activity rhythms of most Siberian hamsters (Phodopus sungorus sungorus) fail to reentrain to a 5-h phase shift of the light-dark (LD) cycle. Instead, their rhythms free-run at periods close to 25 h despite the continued presence of the LD cycle. This lack of behavioral reentrainment necessarily means that molecular oscillators in the master circadian pacemaker, the SCN, were unable to reentrain as well. The authors tested the hypothesis that a phase shift of the LD cycle rendered the SCN incapable of responding to photic input. Animals were exposed to a 5-h phase delay of the photocycle, and activity rhythms were monitored until a lack of reentrainment was confirmed. Hamsters were then housed in constant darkness for 24 h and administered a 30-min light pulse 2 circadian hours after activity onset. Brains were then removed, and tissue sections containing the SCN were processed for in situ hybridization. Sections were probed with Siberian hamster c-fos and per1 mRNA probes because light rapidly induces these 2 genes in the SCN during subjective night but not at other circadian phases. Light pulses induced robust expression of both genes in all animals that reentrained to the LD cycle, but no expression was observed in any animal that failed to reentrain. None of the animals exhibited an intermediate response. This finding is the first report of acute shift in a photocycle eliminating photosensitivity in the SCN and suggests that a specific pattern of light exposure may desensitize the SCN to subsequent photic input.

  1. Water and carboxyl group environments in the dehydration blueshift of bacteriorhodopsin. (United States)

    Renthal, R; Gracia, N; Regalado, R


    The proton channels of the bacteriorhodopsin (BR) proton pump contain bound water molecules. The channels connect the purple membrane surfaces with the protonated retinal Schiff base at the membrane center. Films of purple membrane equilibrated at low relative humidity display a shift of the 570 nm retinal absorbance maximum to 528 nm, with most of the change occurring below 15% relative humidity. Purple membrane films were dehydrated to defined humidities between about 50 and 4.5% and examined by Fourier transform infrared difference spectroscopy. In spectra of dehydrated-minus-hydrated purple membrane, troughs are observed at 3645 and 3550 cm-1, and peaks are observed at 3665 and 3500 cm-1. We attribute these changes to water dissociation from the proton uptake channel and the resulting changes in hydrogen bonding of water that remains bound. Also, in the carboxylic acid spectral region, a trough was observed at 1742 cm-1 and a peak at 1737 cm-1. The magnitude of the trough to peak difference between 1737 and 1742 cm-1 correlates linearly with the extent of the 528 nm pigment. This suggests that a carboxylic acid group or groups is undergoing a change in environment as a result of dehydration, and that this change is linked to the appearance of the 528 nm pigment. Dehydration difference spectra with BR mutants D96N and D115N show that the 1737-1742 cm-1 change is due to Asp 96 and Asp 115. A possible mechanism is suggested that links dissociation of water in the proton uptake channel to the environmental change at the Schiff base site.

  2. Experimental evidence for secondary protein-chromophore interactions at the Schiff base linkage in bacteriorhodopsin: molecular mechanism for proton pumping

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, A.; Marcus, M.A.; Ehrenberg, B.; Crespi, H.


    Resonance Raman spectroscopy of the retinylidene chromophore in various isotopically labeled membrane environments together with spectra of isotopically labeled model compounds demonstrates that a secondary protein interaction is present at the protonated Schiff base linkage in bacteriorhodopsin. The data indicate that although the interaction is present in all protonated bacteriorhodopsin species it is absent in unprotonated intermediates. Furthermore, kinetic resonance Raman spectroscopy has been used to monitor the dynamics of Schiff base deprotonation as a function of pH. All results are consistent with lysine as the interacting group. A structure for the interaction is proposed in which the interacting protein group in an unprotonated configuration is complexed through the Schiff base proton to the Schiff base nitrogen. These data suggest a molecular mechanism for proton pumping and ion gate molecular regulation. In this mechanism, light causes electron redistribution in the retinylidene chromophore, which results in the deprotonation of an amino acid side chain with pK > 10.2 +- 0.3 (e.g., arginine). This induces subsequent retinal and protein conformational transitions which eventually lower the pK of the Schiff base complex from > 12 before light absorption to 10.2 +- 0.3 in microseconds after photon absorption. Finally, in this low pK state the complex can reprotonate the proton-deficient high pK group generated by light, and the complex is then reprotonated from the opposite side of the membrane.

  3. Studying the Mechanism of Phototransformation of Light Signal by Various Mammal and Bacterial Photoreceptor Pigments  Rhodopsin, Iodopsin and Bacteriorhodopsin

    Directory of Open Access Journals (Sweden)

    Ignat Ignatov


    Full Text Available This review article outlines the structure and function of mammal and bacterial photoreceptor pigments (rhodopsin, iodopsin, bacteriorhodopsin and their aspects of bio-nanotechnological usage. On an example of bacteriorhodopsin is described the method of its isolation from purple membranes of photo-organotrophic halobacterium Halobacterium halobium ET 1001 by cellular autolysis by distilled water, processing of bacterial biomass by ultrasound at 22 KHz, alcohol extraction of low and high-weight molecular impurities, cellular RNA, carotenoids and lipids, the solubilization with 0,5 % (w/v SDS-Na and subsequent fractionation by methanol and gel filtration chromatography on Sephadex G-200 Column balanced with 0,09 M Tris-buffer (pH = 8,35 with 0,1 % (w/v SDS-Na and 2,5 mM EDTA. Within the framework of the research the mechanism of color perception by the visual retina analyzer having the ability to analyze certain ranges of the optical spectrum as colors, was studied along with an analysis of the additive mixing of two or more colors. It was shown that at the mixing of electromagnetic waves with different wavelengths, the visual analyzer perceives them as the separate or average wave length corresponding to the mixing color.

  4. The influence of a transmembrane pH gradient on protonation probabilities of bacteriorhodopsin: the structural basis of the back-pressure effect. (United States)

    Calimet, Nicolas; Ullmann, G Matthias


    Bacteriorhodopsin pumps protons across a membrane using the energy of light. The proton pumping is inhibited when the transmembrane proton gradient that the protein generates becomes larger than four pH units. This phenomenon is known as the back-pressure effect. Here, we investigate the structural basis of this effect by predicting the influence of a transmembrane pH gradient on the titration behavior of bacteriorhodopsin. For this purpose we introduce a method that accounts for a pH gradient in protonation probability calculations. The method considers that in a transmembrane protein, which is exposed to two different aqueous phases, each titratable residue is accessible for protons from one side of the membrane depending on its hydrogen-bond pattern. This method is applied to several ground-state structures of bacteriorhodopsin, which residues already present complicated titration behaviors in the absence of a proton gradient. Our calculations show that a pH gradient across the membrane influences in a non-trivial manner the protonation probabilities of six titratable residues which are known to participate in the proton transfer: D85, D96, D115, E194, E204, and the Schiff base. The residues connected to one side of the membrane are influenced by the pH on the other side because of their long-range electrostatic interactions within the protein. In particular, D115 senses the pH at the cytoplasmic side of the membrane and transmits this information to D85 and the Schiff base. We propose that the strong electrostatic interactions found between D85, D115, and the Schiff base as well as the interplay of their respective protonation states under the influence of a transmembrane pH gradient are responsible for the back-pressure effect on bacteriorhodopsin.

  5. Titration kinetics of Asp-85 in bacteriorhodopsin: exclusion of the retinal pocket as the color-controlling cation binding site. (United States)

    Fu, X; Bressler, S; Ottolenghi, M; Eliash, T; Friedman, N; Sheves, M


    The spectrum (the purple blue transition) and function of the light-driven proton pump bacteriorhodopsin are determined by the state of protonation of the Asp-85 residue located in the vicinity of the retinal chromophore. The titration of Asp-85 is controlled by the binding/unbinding of one or two divalent metal cations (Ca2+ or Mg2+). The location of such metal binding site(s) is approached by studying the kinetics of the cation-induced titration of Asp-85 using metal ions and large molecular cations, such as quaternary ammonium ions, R4N+ (R = Et, Pr, a divalent 'bolaform ion' [Et3N+-(CH2)4-N+Et3] and the 1:3 molecular complex formed between Fe2+ and 1,10-phenanthroline (OP). The basic multi-component kinetic features of the titration, extending from 10(-2) to 10(4) s, are unaffected by the charge and size of the cation. This indicates that cation binding to bR triggers the blue --> purple titration in a fast step, which is not rate-determining. In view of the size of the cations involved, these observations indicate that the cation binding site is in an exposed location on, or close to, the membrane surface. This excludes previous models, which placed the color-controlling Ca2+ ion in the retinal binding pocket.

  6. Role of trimer-trimer interaction of bacteriorhodopsin studied by optical spectroscopy and high-speed atomic force microscopy. (United States)

    Yamashita, Hayato; Inoue, Keiichi; Shibata, Mikihiro; Uchihashi, Takayuki; Sasaki, Jun; Kandori, Hideki; Ando, Toshio


    Bacteriorhodopsin (bR) trimers form a two-dimensional hexagonal lattice in the purple membrane of Halobacterium salinarum. However, the physiological significance of forming the lattice has long been elusive. Here, we study this issue by comparing properties of assembled and non-assembled bR trimers using directed mutagenesis, high-speed atomic force microscopy (HS-AFM), optical spectroscopy, and a proton pumping assay. First, we show that the bonds formed between W12 and F135 amino acid residues are responsible for trimer-trimer association that leads to lattice assembly; the lattice is completely disrupted in both W12I and F135I mutants. HS-AFM imaging reveals that both crystallized D96N and non-crystallized D96N/W12I mutants undergo a large conformational change (i.e., outward E-F loop displacement) upon light-activation. However, lattice disruption significantly reduces the rate of conformational change under continuous light illumination. Nevertheless, the quantum yield of M-state formation, measured by low-temperature UV-visible spectroscopy, and proton pumping efficiency are unaffected by lattice disruption. From these results, we conclude that trimer-trimer association plays essential roles in providing bound retinal with an appropriate environment to maintain its full photo-reactivity and in maintaining the natural photo-reaction pathway.

  7. Recent Advances in the Field of Bionanotechnology: An Insight into Optoelectric Bacteriorhodopsin, Quantum Dots, and Noble Metal Nanoclusters

    Directory of Open Access Journals (Sweden)

    Christopher Knoblauch


    Full Text Available Molecular sensors and molecular electronics are a major component of a recent research area known as bionanotechnology, which merges biology with nanotechnology. This new class of biosensors and bioelectronics has been a subject of intense research over the past decade and has found application in a wide variety of fields. The unique characteristics of these biomolecular transduction systems has been utilized in applications ranging from solar cells and single-electron transistors (SETs to fluorescent sensors capable of sensitive and selective detection of a wide variety of targets, both organic and inorganic. This review will discuss three major systems in the area of molecular sensors and electronics and their application in unique technological innovations. Firstly, the synthesis of optoelectric bacteriorhodopsin (bR and its application in the field of molecular sensors and electronics will be discussed. Next, this article will discuss recent advances in the synthesis and application of semiconductor quantum dots (QDs. Finally, this article will conclude with a review of the new and exciting field of noble metal nanoclusters and their application in the creation of a new class of fluorescent sensors.

  8. Structures of aspartic acid-96 in the L and N intermediates of bacteriorhodopsin: analysis by Fourier transform infrared spectroscopy (United States)

    Maeda, A.; Sasaki, J.; Shichida, Y.; Yoshizawa, T.; Chang, M.; Ni, B.; Needleman, R.; Lanyi, J. K.


    The light-induced difference Fourier transform infrared spectrum between the L or N intermediate minus light-adapted bacteriorhodopsin (BR) was measured in order to examine the protonated states and the changes in the interactions of carboxylic acids of Asp-96 and Asp-115 in these intermediates. Vibrational bands due to the protonated and unprotonated carboxylic acid were identified by isotope shift and band depletion upon substitution of Asp-96 or -115 by asparagine. While the signal due to the deprotonation of Asp-96 was clearly observed in the N intermediate, this residue remained protonated in L. Asp-115 was partially deprotonated in L. The C = O stretching vibration of protonated Asp-96 of L showed almost no shift upon 2H2O substitution, in contrast to the corresponding band of Asp-96 or Asp-115 of BR, which shifted by 9-12 cm-1 under the same conditions. In the model system of acetic acid in organic solvents, such an absence of the shift of the C = O stretching vibration of the protonated carboxylic acid upon 2H2O substitution was seen only when the O-H of acetic acid is hydrogen-bonded. The non-hydrogen-bonded monomer showed the 2H2O-dependent shift. Thus, the O-H bond of Asp-96 enters into hydrogen bonding upon conversion of BR to L. Its increased hydrogen bonding in L is consistent with the observed downshift of the O-H stretching vibration of the carboxylic acid of Asp-96.

  9. pH-Sensitive photoinduced energy transfer from bacteriorhodopsin to single-walled carbon nanotubes in SWNT-bR hybrids. (United States)

    El Hadj, Karim; Bertoncini, Patricia; Chauvet, Olivier


    Energy transfer mechanisms in noncovalently bound bacteriorhodopsin/single-walled carbon nanotube (SWNT) hybrids are investigated using optical absorption and photoluminescence excitation measurements. The morphology of the hybrids was investigated by atomic force microscopy. In this study, proteins are immobilized onto the sidewall of the carbon nanotubes using a sodium cholate suspension-dialysis method that maintains the intrinsic optical and fluorescence properties of both molecules. The hybrids are stable in aqueous solutions for pH ranging from 4.2 to 9 and exhibit photoluminescence properties that are pH-dependent. The study reveals that energy transfer from bacteriorhodopsin to carbon nanotubes takes place. So, at pH higher than 5 and up to 9, the SWNTs absorb the photons emitted by the aromatic residues of the protein, inducing a strong increase in intensity of the E11 emissions of SWNTs through their E33 and E44 excitations. From pH = 4.2 to pH = 5, the protein fluorescence is strongly quenched whatever the emission wavelengths, while additional fluorescence features appear at excitation wavelengths ranging from 660 to 680 nm and at 330 nm. The presence of these features is attributed to a resonance energy transfer mechanism that has an efficiency of 0.94 ± 0.02. More, by increasing the pH of the dispersion, the fluorescence characteristics become those observed at higher pH values and vice versa.

  10. The Improved Method for Isolation of Photochrome Trans-membrane Protein Bacteriorhodopsin from Purple Membranes of Halobacterium Halobacterium Halobium ET 1001

    Directory of Open Access Journals (Sweden)

    Oleg Mosin


    Full Text Available It was developed the improved method for isolation of photochrome trans-membraine protein bacteriorhodopsin (output – 5 mg from 100 g of wet biomass capable to transform light energy to electrochemical energy of generated protons H+ and АТP. The protein was isolated from purple membranes of photo-organotrophic halobacterium Halobacterium halobium ET 1001 by cellular autolysis by distilled water, processing of bacterial biomass by ultrasound at 22 KHz, alcohol extraction of low and high-weight molecular impurities, cellular RNA, carotenoids and lipids, solubilization with 0.5% (w/v SDS-Na, fractionation by MeOH and column gel permeation chromatography (GPC of the final protein on Sephadex G-200 with 0.1% (w/v SDS-Na and 2.5 mM ETDA. The homogeneity of the isolated bacteriorhodopsin was proved by combination of preparative and analytical methods, including elecrtophoresis in 12.5% (w/v PAAG with 0.1% (w/v SDS-Na and regeneration of apomembranes with 13-trans-retinal.

  11. An Observation of Diamond-Shaped Particle Structure in a Soya Phosphatidylcohline and Bacteriorhodopsin Composite Langmuir Blodgett Film Fabricated by Multilayer Molecular Thin Film Method (United States)

    Tsujiuchi, Y.; Makino, Y.

    A composite film of soya phosphatidylcohline (soya PC) and bacteriorhodopsin (BR) was fabricated by the multilayer molecular thin film method using fatty acid and lipid on a quartz substrate. Direct Force Microscopy (DFM), UV absorption spectra and IR absorption spectra of the film were characterized on the detail of surface structure of the film. The DFM data revealed that many rhombus (diamond-shaped) particles were observed in the film. The spectroscopic data exhibited the yield of M-intermediate of BR in the film. On our modelling of molecular configuration indicate that the coexistence of the strong inter-molecular interaction and the strong inter-molecular interaction between BR trimmers attributed to form the particles.

  12. Spectroscopic analysis of the dark relaxation process of a photocycle in a sensor of blue light using FAD (BLUF) protein Slr1694 of the cyanobacterium Synechocystis sp. PCC6803. (United States)

    Hasegawa, Koji; Masuda, Shinji; Ono, Taka-Aki


    Slr1694 is a BLUF (sensor of blue light using flavin adenine dinucleotide) protein and a putative photoreceptor in the cyanobacterium Synechocystis sp. PCC6803. Illumination of Slr1694 induced a signaling light state concurrent with a red shift in the UV-visible absorption of flavin, and formation of the bands from flavin and apo-protein in the light-minus-dark Fourier transform infrared (FTIR) difference spectrum. Replacement of Tyr8 with phenylalanine abolished these changes. The light state relaxed to the ground dark state, during which the FTIR bands decayed monophasically. These bands were classifiable into three groups according to their decay rates. The C4=O stretching bands of a flavin isoalloxazine ring had the highest decay rate, which corresponded to that of the absorption red shift. The result indicated that the hydrogen bonding at C4=O is responsible for the UV-visible red shift, consistent with the results of density functional calculation. All FTIR bands and the red shift decayed at the same slower rate in deuterated Slr1694. These results indicated that the dark relaxation from the light state is limited by proton transfer. In contrast, a constrained light state formed under dehydrated conditions decayed much more slowly with no deuteration effects. A photocycle mechanism involving the proton transfer was proposed.

  13. Vibrational spectroscopy of bacteriorhodopsin mutants: light-driven proton transport involves protonation changes of aspartic acid residues 85, 96, and 212

    Energy Technology Data Exchange (ETDEWEB)

    Braiman, M.S.; Mogi, T.; Marti, T.; Stern, L.J.; Khorana, H.G.; Rothschild, K.J.


    Fourier transform infrared (FTIR) difference spectra have been obtained for the bR----K, bR----L, and bR----M photoreactions in bacteriorhodopsin mutants in which Asp residues 85, 96, 115, and 212 have been replaced by Asn and by Glu. Difference peaks that had previously been attributed to Asp COOH groups on the basis of isotopic labeling were absent or shifted in these mutants. In general, each COOH peak was affected strongly by mutation at only one of the four residues. Thus, it was possible to assign each peak tentatively to a particular Asp. From these assignments, a model for the proton-pumping mechanism of bR is derived, which features proton transfers among Asp-85, -96, and -212, the chromophore Schiff base, and other ionizable groups within the protein. The model can explain the observed COOH peaks in the FTIR difference spectra of bR photointermediates and could also account for other recent results on site-directed mutants of bR.

  14. Identification of Specific Effect of Chloride on the Spectral Properties and Structural Stability of Multiple Extracellular Glutamic Acid Mutants of Bacteriorhodopsin (United States)

    Lazarova, Tzvetana; Mlynarczyk, Krzysztof; Querol, Enric; Tenchov, Boris; Filipek, Slawomir; Padrós, Esteve


    In the present work we combine spectroscopic, DSC and computational approaches to examine the multiple extracellular Glu mutants E204Q/E194Q, E204Q/E194Q/E9Q and E204Q/E194Q/E9Q/E74Q of bacteriorhodopsin by varying solvent ionic strength and composition. Absorption spectroscopy data reveal that the absorption maxima of multiple EC Glu mutants can be tuned by the chloride concentration in the solution. Visible Circular dichroism spectra imply that the specific binding of Cl- can modulate weakened exciton chromophore coupling and reestablish wild type-like bilobe spectral features of the mutants. The DSC data display reappearance of the reversible thermal transition, higher Tm of denaturation and an increase in the enthalpy of unfolding of the mutants in 1 M KCl solutions. Molecular dynamics simulations indicate high affinity binding of Cl- to Arg82 and to Gln204 and Gln194 residues in the mutants. Analysis of the experimental data suggests that simultaneous elimination of the negatively charged side chain of Glu194 and Glu204 is the major cause for mutants’ alterations. Specific Cl- binding efficiently coordinates distorted hydrogen bonding interactions of the EC region and reconstitutes the conformation and structure stability of mutated bR in WT-like fashion. PMID:27657718

  15. Incorporation of the dopamine D2L receptor and bacteriorhodopsin within bicontinuous cubic lipid phases. 2. Relevance to in meso crystallization of integral membrane proteins in novel lipid systems

    Energy Technology Data Exchange (ETDEWEB)

    Conn, Charlotte E.; Darmanin, Connie; Sagnella, Sharon M.; Mulet, Xavier; Greaves, Tamar L.; Varghese, Joseph N.; Drummond, Calum J.


    The dopamine D2 long (D2L) receptor and bacteriorhodopsin (bR), which are integral membraneproteins, have been incorporated within bicontinuous cubic mesophases formed by the lipids anandamide and H-farnesoyl monoethanolamide, which have been specifically investigated by us for use as in mesocrystallization media. We show that the incorporated membraneprotein affects the structure of the cubic phases with the particular effect observed dependent on the geometry of the underlying cubic phase. The results are complementary to those obtained in Part 1 of this series, where we demonstrated that the structural effects observed depend on the structure of the membraneprotein. Importantly protein concentrations commonly used for crystallization can destroy the cubic phase matrix, particularly where there is a large discrepancy between the hydrophilic and the hydrophobic spans of the membraneprotein, and the hydrophilic and hydrophobic domain sizes of the cubic phase.

  16. 化学增强细菌视紫红质膜对高斯光束的自整形%Self-shaping of Gaussian Beam by Chemically Enhanced Bacteriorhodopsin Film

    Institute of Scientific and Technical Information of China (English)

    王勇; 富光华; 等


    A CW Gaussian-beam illuminates a thin film of chemically enhanced bacteriorhodopsin (bR),and then strong self-defocusing of the Gaussian beam passing the bR film will be shown when the ilumination intensity is greater than 220 W/cm2 for the sample used.Owing to this effect,the self-shaping of Gasussian beam can be realized.The analyses show the incidentbeam intensity and the thickness and concentration of the bR film influence the transverse profile of the transmitted beam.%连续激光束照射化学增强的细菌视紫红质膜.当照射强度大于某一定值,光束产生强的自散焦效应.通过这个效应可以实现高斯光束的自整形.本文讨论了入射光以及bR膜的各项参数对透过光束强度的横向轮廓的影响.

  17. Regio-selective detection of dynamic structure of transmembrane alpha-helices as revealed from (13)C NMR spectra of [3-13C]Ala-labeled bacteriorhodopsin in the presence of Mn2+ ion. (United States)

    Tuzi, S; Hasegawa, J; Kawaminami, R; Naito, A; Saitô, H


    13C Nuclear magnetic resonance (NMR) spectra of [3-(13)C]Ala-labeled bacteriorhodopsin (bR) were edited to give rise to regio-selective signals from hydrophobic transmembrane alpha-helices by using NMR relaxation reagent, Mn(2+) ion. As a result of selective suppression of (13)C NMR signals from the surfaces in the presence of Mn(2+) ions, several (13)C NMR signals of Ala residues in the transmembrane alpha-helices were identified on the basis of site-directed mutagenesis without overlaps from (13)C NMR signals of residues located near the bilayer surfaces. The upper bound of the interatomic distances between (13)C nucleus in bR and Mn(2+) ions bound to the hydrophilic surface to cause suppressed peaks by the presence of Mn(2+) ion was estimated as 8.7 A to result in the signal broadening to 100 Hz and consistent with the data based on experimental finding. The Ala C(beta) (13)C NMR peaks corresponding to Ala-51, Ala-53, Ala-81, Ala-84, and Ala-215 located around the extracellular half of the proton channel and Ala-184 located at the kink in the helix F were successfully identified on the basis of (13)C NMR spectra of bR in the presence of Mn(2+) ion and site-directed replacement of Ala by Gly or Val. Utilizing these peaks as probes to observe local structure in the transmembrane alpha-helices, dynamic conformation of the extracellular half of bR at ambient temperature was examined, and the local structures of Ala-215 and 184 were compared with those elucidated at low temperature. Conformational changes in the transmembrane alpha-helices induced in D85N and E204Q and its long-range transmission from the proton release site to the site around the Schiff base in E204Q were also examined.

  18. ESR - a retinal protein with unusual properties from Exiguobacterium sibiricum. (United States)

    Petrovskaya, L E; Balashov, S P; Lukashev, E P; Imasheva, E S; Gushchin, I Yu; Dioumaev, A K; Rubin, A B; Dolgikh, D A; Gordeliy, V I; Lanyi, J K; Kirpichnikov, M P


    This review covers the properties of a retinal protein (ESR) from the psychrotrophic bacterium Exiguobacterium sibiricum that functions as a light-driven proton pump. The presence of a lysine residue at the position corresponding to intramolecular proton donor for the Schiff base represents a unique structural feature of ESR. We have shown that Lys96 successfully facilitates delivery of protons from the cytoplasmic surface to the Schiff base, thus acting as a proton donor in ESR. Since proton uptake during the photocycle precedes Schiff base reprotonation, we conclude that this residue is initially in the uncharged state and acquires a proton for a short time after Schiff base deprotonation and M intermediate formation. Involvement of Lys as a proton donor distinguishes ESR from the related retinal proteins - bacteriorhodopsin (BR), proteorhodopsin (PR), and xanthorhodopsin (XR), in which the donor function is performed by residues with a carboxyl side chain. Like other eubacterial proton pumps (PR and XR), ESR contains a histidine residue interacting with the proton acceptor Asp85. In contrast to PR, this interaction leads to shift of the acceptor's pKa to more acidic pH, thus providing its ability to function over a wide pH range. The presence of a strong H-bond between Asp85 and His57, the structure of the proton-conducting pathways from cytoplasmic surface to the Schiff base and to extracellular surface, and other properties of ESR were demonstrated by solving its three-dimensional structure, which revealed several differences from known structures of BR and XR. The structure of ESR, its photocycle, and proton transfer reactions are discussed in comparison with homologous retinal proteins.

  19. NADAC Comparison (United States)

    U.S. Department of Health & Human Services — The NADAC Weekly Comparison identifies the drug products with current NADAC rates that are replaced with new NADAC rates. Other changes (e.g. NDC additions and...

  20. Introduction of Deuterated Aromatic Amino Acids  [2,3,4,5,6-2H5]phenylalanine, [3,5-2H2]tyrosine and [2,4,5,6,7-2H5]tryptophan into a Molecule of Photochrome Trans-membrane Protein Bacteriorhodopsin

    Directory of Open Access Journals (Sweden)

    Oleg Mosin


    Full Text Available It was carried out the introduction of functionally important deuterated aromatic amino acids  [2,3,4,5,6-2H5]phenylalanine, [3,5-2H2]tyrosine and [2,4,5,6,7-2H5]tryptophan into a molecule of photochrome trans-membrane protein bacteriorhodopsin, synthesized by a photo-organotrophic halobacterium Halobacterium halobium ET 1001. The deuterated protein (output 810 mg was isolated from purple membranes by cellular autolysis by distilled water, processing of bacterial biomass by ultrasound at 22 KHz, alcohol extraction of low and high-weight molecular impurities, cellular RNA, carotenoids and lipids, with the subsequent solubilization of final product with 0,5 % (w/v SDS-Na and fractionation by methanol, gel filtration chromatography on Sephadex G-200, reverse-phase HPLC and EI impact mass-spectrometry of methyl esters of N-Dns-[2H]derivatives of amino acids. Deuterium was detected in all residues of aromatic amino acids. However, the presence in the EI mass spectrum of the BR hydrolysate the peaks [M]+ of semi-deuterated analogues of aromatic amino acids  phenylalanine with [M]+ at m/z = 413418, tyrosine  with [M]+ at m/z = 428430 and tryptophan  with [M]+ at m/z = 453457 with different levels of contributions to the deuterium enrichment of molecules testifies about the conservation of the minor pathways of biosynthesis of aromatic amino acids de novo.

  1. Cost comparisons

    CERN Document Server

    CERN Bulletin


    How much does the LHC cost? And how much does this represent in other currencies? Below we present a table showing some comparisons with the cost of other projects. Looking at the figures, you will see that the cost of the LHC can be likened to that of three skyscrapers, or two seasons of Formula 1 racing! One year's budget of a single large F1 team is comparable to the entire materials cost of the ATLAS or CMS experiments.   Please note that all the figures are rounded for ease of reading.    CHF € $   LHC 4.6 billions 3 billions  4 billions   Space Shuttle Endeavour (NASA) 1.9 billion 1.3 billion 1.7 billion   Hubble Space Telescope (cost at launch – NASA/...

  2. Dimensional comparison theory. (United States)

    Möller, Jens; Marsh, Herb W


    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.

  3. Satisfaction and 'comparison sharing'

    DEFF Research Database (Denmark)

    Amilon, Anna


    the probability of satisfaction. Results show that comparison sharing impacts satisfaction for women, and that those women who share more equally than their peers are more likely to be satisfied, whereas comparison sharing has no influence on satisfaction for men. Also, parents are less likely to be satisfied...

  4. Acquisition of Comparison Constructions (United States)

    Hohaus, Vera; Tiemann, Sonja; Beck, Sigrid


    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…

  5. Role of active site conformational changes in photocycle activation of the AppA BLUF photoreceptor. (United States)

    Goyal, Puja; Hammes-Schiffer, Sharon


    Blue light using flavin adenine dinucleotide (BLUF) proteins are essential for the light regulation of a variety of physiologically important processes and serve as a prototype for photoinduced proton-coupled electron transfer (PCET). Free-energy simulations elucidate the active site conformations in the AppA (activation of photopigment and puc expression) BLUF domain before and following photoexcitation. The free-energy profile for interconversion between conformations with either Trp104 or Met106 closer to the flavin, denoted Trpin/Metout and Trpout/Metin, reveals that both conformations are sampled on the ground state, with the former thermodynamically favorable by ∼3 kcal/mol. These results are consistent with the experimental observation of both conformations. To analyze the proton relay from Tyr21 to the flavin via Gln63, the free-energy profiles for Gln63 rotation were calculated on the ground state, the locally excited state of the flavin, and the charge-transfer state associated with electron transfer from Tyr21 to the flavin. For the Trpin/Metout conformation, the hydrogen-bonding pattern conducive to the proton relay is not thermodynamically favorable on the ground state but becomes more favorable, corresponding to approximately half of the configurations sampled, on the locally excited state. The calculated energy gaps between the locally excited and charge-transfer states suggest that electron transfer from Tyr21 to the flavin is more facile for configurations conducive to proton transfer. When the active site conformation is not conducive to PCET from Tyr21, Trp104 can directly compete with Tyr21 for electron transfer to the flavin through a nonproductive pathway, impeding the signaling efficiency.

  6. Statistical Group Comparison

    CERN Document Server

    Liao, Tim Futing


    An incomparably useful examination of statistical methods for comparisonThe nature of doing science, be it natural or social, inevitably calls for comparison. Statistical methods are at the heart of such comparison, for they not only help us gain understanding of the world around us but often define how our research is to be carried out. The need to compare between groups is best exemplified by experiments, which have clearly defined statistical methods. However, true experiments are not always possible. What complicates the matter more is a great deal of diversity in factors that are not inde

  7. Public opinion: Country comparisons (United States)

    Hopkins, Debbie


    Climate change awareness, risk perception and policy support vary between and within countries. National-scale comparisons can help to explain this variability and be used to develop targeted interventions.

  8. Matrix comparison, Part 2

    DEFF Research Database (Denmark)

    Schneider, Jesper Wiborg; Borlund, Pia


    The present two-part article introduces matrix comparison as a formal means for evaluation purposes in informetric studies such as cocitation analysis. In the first part, the motivation behind introducing matrix comparison to informetric studies, as well as two important issues influencing...... such comparisons, matrix generation, and the composition of proximity measures, are introduced and discussed. In this second part, the authors introduce and thoroughly demonstrate two related matrix comparison techniques the Mantel test and Procrustes analysis, respectively. These techniques can compare...... important. Alternatively, or as a supplement, Procrustes analysis compares the actual ordination results without investigating the underlying proximity measures, by matching two configurations of the same objects in a multidimensional space. An advantage of the Procrustes analysis though, is the graphical...

  9. Model comparison in ANOVA. (United States)

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


    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.

  10. CCF model comparison

    Energy Technology Data Exchange (ETDEWEB)

    Pulkkinen, U. [VTT Industrial Systems (Finland)


    The report describes a simple comparison of two CCF-models, the ECLM, and the Beta-model. The objective of the comparison is to identify differences in the results of the models by applying the models in some simple test data cases. The comparison focuses mainly on theoretical aspects of the above mentioned CCF-models. The properties of the model parameter estimates in the data cases is also discussed. The practical aspects in using and estimating CCFmodels in real PSA context (e.g. the data interpretation, properties of computer tools, the model documentation) are not discussed in the report. Similarly, the qualitative CCF-analyses needed in using the models are not discussed in the report. (au)

  11. Vizualizing Interfirm Comparison

    NARCIS (Netherlands)

    E.M. Vermeulen (Erik); J. Spronk (Jaap); D. van der Wijst (Nico)


    textabstractIn this paper, we present a new way to visualize the results obtained with interfirm comparison. It will be shown how these results can be visualized even if the explanatory variable is explained by more than one firm characteristic. As a result, the new visualization method enables us t

  12. Comparison of OMI NO

    NARCIS (Netherlands)

    Ialongo, Iolanda; Herman, Jay; Krotkov, Nick; Lamsal, Lok; Boersma, Folkert; Hovila, Jari; Tamminen, Johanna


    We present the comparison of satellite-based OMI (Ozone Monitoring Instrument) NO2 products with ground-based observations in Helsinki. OMI NO2 total columns, available from NASA's standard product (SP) and KNMI DOMINO product, are compared with the measurements performed by

  13. Dimensional Comparison Theory

    Directory of Open Access Journals (Sweden)

    Friederike Helm


    Full Text Available Dimensional comparison theory (DCT defines dimensional comparisons as intraindividual comparisons that a person draws between his or her own achievements in two domains or subjects. DCT assumes that dimensional comparisons influence students’ academic self-concepts, causing stronger self-concept differences between subjects perceived as dissimilar, such as math and English, than between subjects perceived as more similar, like math and physics. However, there have been no experimental studies testing the causal effect of perceived subject similarity on domain-specific self-concepts. In the present research, three experimental studies analyzed the effects of experimentally induced higher or lower perceived subject similarity on academic self-concept differences: Study 1 (N = 351, with math and German; Study 2a (N = 148, with math and physics; and Study 2b (N = 161, with English and German, show that, in line with expectations, induced lower perceived subject similarity led to stronger self-concept differences than did higher perceived similarity. Some implications of the results for DCT are discussed.

  14. MCNP and GADRAS Comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Klasky, Marc Louis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Myers, Steven Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); James, Michael R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mayo, Douglas R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    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.

  15. On molecular graph comparison. (United States)

    Melo, Jenny A; Daza, Edgar


    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.

  16. Comparison of galled trees. (United States)

    Cardona, Gabriel; Llabrés, Mercè; Rosselló, Francesc; Valiente, Gabriel


    Galled trees, directed acyclic graphs that model evolutionary histories with isolated hybridization events, have become very popular due to both their biological significance and the existence of polynomial-time algorithms for their reconstruction. In this paper, we establish to which extent several distance measures for the comparison of evolutionary networks are metrics for galled trees, and hence, when they can be safely used to evaluate galled tree reconstruction methods.

  17. Comparison of Power for Multiple Comparison Procedures

    Directory of Open Access Journals (Sweden)

    Robert S. Rodger


    Full Text Available The number of methods for evaluating, and possibly making statistical decisions about, null contrasts - or their small sub-set, multiple comparisons - has grown extensively since the early 1950s. That demonstrates how important the subject is, but most of the growth consists of modest variations of the early methods. This paper examines nine fairly basic procedures, six of which are methods designed to evaluate contrasts chosen post hoc, i.e., after an examination of the test data. Three of these use experimentwise or familywise type 1 error rates (Scheffé 1953, Tukey 1953, Newman-Keuls, 1939 and 1952, two use decision-based type 1 error rates (Duncan 1951 and Rodger 1975a and one (Fisher's LSD 1935 uses a mixture of the two type 1 error rate definitions. The other three methods examined are for evaluating, and possibly deciding about, a limited number of null contrasts that have been chosen independently of the sample data - preferably before the data are collected. One of these (planned t-tests uses decision-based type 1 error rates and the other two (one based on Bonferroni's Inequality 1936, and the other Dunnett's 1964 Many-One procedure use a familywise type 1 error rate. The use of these different type 1 error rate definitionsA creates quite large discrepancies in the capacities of the methods to detect true non-zero effects in the contrasts being evaluated. This article describes those discrepancies in power and, especially, how they are exacerbated by increases in the size of an investigation (i.e., an increase in J, the number of samples being examined. It is also true that the capacity of a multiple contrast procedure to 'unpick' 'true' differences from the sample data is influenced by the type of contrast the procedure permits. For example, multiple range procedures (such as that of Newman-Keuls and that of Duncan permit only comparisons (i.e., two-group differences and that greatly limits their discriminating capacity (which is not

  18. NTP comparison process (United States)

    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. Comparisons and lessons learned

    DEFF Research Database (Denmark)


    Purpose: To create an overview and evaluation of the achievements of the contributions in this book by identifying, summarising and discussing cross-cutting themes and essential learning points across the former chapters. Methodology: Based on a purposeful reading of all chapters comparisons......: The advancement in new knowledge and understanding that this book provides offers a new state of the art which can give inspiration and guidance for cutting edge FM organisations and professionals as well as for advanced teaching and future research. Research limitations: The chapter is based on the contributions...

  20. Long History of IAM Comparisons

    Energy Technology Data Exchange (ETDEWEB)

    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


    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.

  1. Geology orbiter comparison study (United States)

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


    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.

  2. CIRP Interlaboratory Comparison

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Hansen, Hans Nørgaard; Morace, Renata Erica

    An interlaboratory comparison on mechanical and optical coordinate measuring machines (CMMs) was organized by the Centre for Geometrical Metrology (CGM), Department of Manufacturing Engineering and Management (IPL), Technical University of Denmark (DTU) and carried out within Collège International......, USA. A total of 23 CMMs (12 mechanical and 11 optical) were used to measure an optomechanical hole plate designed and manufactured by DTU. A measurement procedure was sent to each participant together with a plate to be measured. The measurement procedure refers to the German DKD guideline, using...... the reversal method with traceability achieved by a comparator measurement. Using the optomechanical hole plate, the measurement procedure can be carried out on optical as well as mechanical measuring machines. Circulation started in March 2003, and was completed in September 2003, whit three optomechanical...

  3. NTF – wind speed comparison

    DEFF Research Database (Denmark)

    Vesth, Allan; Gómez Arranz, Paula

    The report describes measurements carried out on a given turbine. A comparison between wind speed on the met mast and Nacelle Wind speed are made and the results are presented on graphs and in a table. The data used for the comparison are the data that are same as used for the power curve report...

  4. Improving the DGK comparison protocol

    NARCIS (Netherlands)

    Veugen, P.J.M.


    When processing signals in the encrypted domain, homomorphic encryption can be used to enable linear operations on encrypted data. Comparison of encrypted data however requires an additional protocol between the parties and will be relatively expensive. A well-known and frequently used comparison pr

  5. Social Comparison Processes in Organizations (United States)

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


    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,…

  6. Rankings from Fuzzy Pairwise Comparisons

    NARCIS (Netherlands)

    Broek, van den Pim; Noppen, Joost; Mohammadian, M.


    We propose a new method for deriving rankings from fuzzy pairwise comparisons. It is based on the observation that quantification of the uncertainty of the pairwise comparisons should be used to obtain a better crisp ranking, instead of a fuzzified version of the ranking obtained from crisp pairwise

  7. Social Comparison in the Classroom: A Review (United States)

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


    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…

  8. [Anemia: guidelines comparison]. (United States)

    Del Vecchio, Lucia


    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.

  9. International comparisons in mathematics education

    CERN Document Server

    Huntly, Ian; Luna, Eduardo


    This text explores international comparisons in mathematics education and highlights strengths and weaknesses in various systems world-wide, allowing teachers, researchers and academics to compare and contrast different approaches.

  10. Comparisons between China and India

    Institute of Scientific and Technical Information of China (English)



    Comparisons between China and India abound. However, the usual comparisons are based on the GDP growth rates, exports, or FDI etc., and thus have not taken us analytically far. An appreciation of the so far understated dissimilarities between the two economies,especially the social settings in which they work, would not only help in understanding better the nature of profound transformation that the both are going through, but would enhance our theoretical understanding of other developing/transitional economies as well.

  11. Active Ranking using Pairwise Comparisons

    CERN Document Server

    Jamieson, Kevin G


    This paper examines the problem of ranking a collection of objects using pairwise comparisons (rankings of two objects). In general, the ranking of $n$ objects can be identified by standard sorting methods using $n log_2 n$ pairwise comparisons. We are interested in natural situations in which relationships among the objects may allow for ranking using far fewer pairwise comparisons. Specifically, we assume that the objects can be embedded into a $d$-dimensional Euclidean space and that the rankings reflect their relative distances from a common reference point in $R^d$. We show that under this assumption the number of possible rankings grows like $n^{2d}$ and demonstrate an algorithm that can identify a randomly selected ranking using just slightly more than $d log n$ adaptively selected pairwise comparisons, on average. If instead the comparisons are chosen at random, then almost all pairwise comparisons must be made in order to identify any ranking. In addition, we propose a robust, error-tolerant algorith...

  12. Visual comparison for information visualization

    KAUST Repository

    Gleicher, M.


    Data analysis often involves the comparison of complex objects. With the ever increasing amounts and complexity of data, the demand for systems to help with these comparisons is also growing. Increasingly, information visualization tools support such comparisons explicitly, beyond simply allowing a viewer to examine each object individually. In this paper, we argue that the design of information visualizations of complex objects can, and should, be studied in general, that is independently of what those objects are. As a first step in developing this general understanding of comparison, we propose a general taxonomy of visual designs for comparison that groups designs into three basic categories, which can be combined. To clarify the taxonomy and validate its completeness, we provide a survey of work in information visualization related to comparison. Although we find a great diversity of systems and approaches, we see that all designs are assembled from the building blocks of juxtaposition, superposition and explicit encodings. This initial exploration shows the power of our model, and suggests future challenges in developing a general understanding of comparative visualization and facilitating the development of more comparative visualization tools. © The Author(s) 2011.

  13. On the Benefit of Dimensional Comparisons (United States)

    Pohlmann, Britta; Moller, Jens


    People not only use social comparisons to evaluate their abilities, they also engage in dimensional comparisons, comparing their own achievement in different domains. Processes of dimensional comparison have contrasting effects on subject-specific self-concepts: downward dimensional comparisons result in higher self-concept in the…

  14. Social Comparison in the Classroom : A Review

    NARCIS (Netherlands)

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


    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, dimension

  15. Asymmetrical reaction pathways for thermal and photocyclization of 1,3,5-hexatriene to 1,3-cyclohexadiene

    Energy Technology Data Exchange (ETDEWEB)

    Pichko, V.A.; Simkin, B.Ya.; Minkin, V.I.


    The theory of conservation of orbital symmetry in concerted reactions, outlined by Woodward and Hoffman, plays the dominant role in the prediction of the stereospecificity of these reactions both in the ground state and in excited states. Despite the importance of this theory with regard to preference for the conrotatory or dysrotatory pathway of cyclization, quantum chemical calculations of the critical portions of the potential energy surface of the ground and excited states become necessary in understanding the detailed mechanism of both thermal and photochemical transformations. The authors use these calculations to find, in the absence of symmetry, the potential energy surfaces of these states for 1,3,5-hexatriene and analyze the allowed and forbidden reaction pathways in its cyclization.

  16. Ordinal Comparison of Multidimensional Deprivation

    DEFF Research Database (Denmark)

    Sonne-Schmidt, Christoffer Scavenius; Tarp, Finn; Østerdal, Lars Peter

    This paper develops an ordinal method of comparison of multidimensional inequality. In our model, population distribution g is more unequal than f when the distributions have common median and can be obtained from f  by one or more shifts in population density that increase inequality. For our be...... benchmark 2x2 case (i.e. the case of two binary outcome variables), we derive an empirical method for making inequality comparisons. As an illustration, we apply the model to childhood poverty in Mozambique.......This paper develops an ordinal method of comparison of multidimensional inequality. In our model, population distribution g is more unequal than f when the distributions have common median and can be obtained from f  by one or more shifts in population density that increase inequality. For our...

  17. Ordinal Comparison of Multidimensional Deprivation

    DEFF Research Database (Denmark)

    Sonne-Schmidt, Christoffer Scavenius; Tarp, Finn; Østerdal, Lars Peter

    This paper develops an ordinal method of comparison of multidimensional inequality. In our model, population distribution g is more unequal than f when the distributions have common median and can be obtained from f  by one or more shifts in population density that increase inequality. For our be...... benchmark 2x2 case (i.e. the case of two binary outcome variables), we derive an empirical method for making inequality comparisons. As an illustration, we apply the model to childhood poverty in Mozambique....

  18. International Comparisons and Educational Reform. (United States)

    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…

  19. Matrixed business support comparison study.

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, Josh D.


    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.

  20. Homomorphic encryption and secure comparison

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Geisler, Martin; Krøigaard, Mikkel


    We propose a protocol for secure comparison of integers based on homomorphic encryption.We also propose a homomorphic encryption scheme that can be used in our protocol, makes it more efficient than previous solutions, and can also be used as the basis of efficient and general secure Multiparty C...

  1. Cross-National Yardstick Comparisons

    DEFF Research Database (Denmark)

    Hansen, Kasper Møller; Olsen, Asmus Leth; Bech, Michael


    test this proposition using a unique, choice experiment embedded in the 2011 Danish National Election Study. This design allows to contrast cross-national comparisons with more traditional national sociotropic and egotropic concerns. The findings suggest that voters are strongly influenced by cross...... compared to their positive response to cross-national gains—indicating a negativity bias in voters’ preferences....

  2. [Individual difference in making temporal comparisons: development of Temporal Comparison Orientation Scale]. (United States)

    Namikawa, Tsutomu


    This study developed the Temporal Comparison Orientation Scale and investigated its reliability and validity. Study 1 (N = 481) examined the factor structure and correlations with other related scales (self-consciousness scale; revaluation tendency scale; self-esteem scale; depression scale; social comparison orientation scale). The results suggested that the Temporal Comparison Orientation Scale had good reliability and validity. Study 2 examined the relationship between temporal comparison orientation and affect generated by temporal comparisons. The results showed that individuals high in temporal comparison orientation experienced more negative affect after upward and downward comparisons than individuals low in temporal comparison orientation. The possible uses and limitations of the scale were discussed.

  3. Pluralism and Objectivism: Cornerstones for Interpersonal Comparisons

    DEFF Research Database (Denmark)

    Nielsen, Lasse


    comparison, and between a subjectivist and objectivist standard of interpersonal comparison. The paper provides a normative argument for pluralism and objectivism with regard to interpersonal comparison, and it suggests that the Capability Approach as developed by Amartya Sen and Martha Nussbaum fits...

  4. Comparisons of EVD and DVD

    Institute of Scientific and Technical Information of China (English)

    YAN Ming; DAI Jian-hua; HU Guo-rong


    The goal of the Enhanced Versatile Disc (EVD) standard is to define an advanced high definition disc competing with Digital Versatile Disc (DVD). The EVD standard consists of the physical specification, the file system specification, and the specification for audio/video data and Enhanced(x) Audio Coding (ExAC) technology. EVD is an integrated system similar to DVD. Comprehensive comparisons of EVD and DVD are given in this paper. Their key differences include disc formats, file system structures, data structures, audio/video coding, and other issues. Among them,we emphasize on the logic structure of EVD data and its enhanced audio coding method ExAC. We can draw conclusions through these comparisons that EVD is more the advantageous.

  5. High pressure rinsing system comparison

    Energy Technology Data Exchange (ETDEWEB)

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


    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

  6. Comparison of BIOPATH and MARCEN

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, R.A.; Barrdahl, R. [Swedish Radiation Protection Inst., Stockholm (Sweden); Bergstroem, U.; Nordlinder, S. [Studsvik Eco and Safety AB, Nykoeping (Sweden)


    The present report discusses a comparison of two models for assessing the environmental transfer of radionuclides from routine releases to the sea from nuclear power plants: BIOPATH and MARCEN. The purpose of the comparison was to assess the credibility of MARCEN`s predictions of doses to critical groups. BIOPATH, which has previously been validated and compared with other models, was a suitable code for this purpose. The releases from Ringhals during 1993 were used for the comparison. For this scenario BIOPATH and MARCEN predicted the same critical radionuclide/pathway combinations. The observed quantitative disagreement between the models was mainly due to scale differences. The ratio of the mean values predicted by BIOPATH and MARCEN ranged from 0.91 ({sup 60}Co/shellfish) to 2.43 ({sup 137}Cs/fish). The observed differences between the models are small in general, and can be neglected if the predicted doses are one or more orders of magnitude below the dose limits. 8 refs, 12 figs, 9 tabs.

  7. A Model for Light-Driven Proton Pump and Transfer in Bacteriorhodopsin

    Institute of Scientific and Technical Information of China (English)

    黄玉华; 赵有源; 欧阳小平; 李富铭; 丁建东; 李庆国


    A theoretical model was assumed to describe the kinetic processes of light-driven proton pump and motion. The calculation shows that the photovoltage signals are greatly affected by experimental conditions including pulse width of excitation and impedance of measurement system. At the same excitation, only a negative photovoltage signal can be observed with small impedance and both the negative and positive signals can be observed with large impedance. With the same impedance, shorter response time of the pulsed photoelectric signals is responsible for shorter pulsed excitation. All these phenomena are in good agreement with the experimental results.

  8. Comparison of automatic control systems (United States)

    Oppelt, W


    This report deals with a reciprocal comparison of an automatic pressure control, an automatic rpm control, an automatic temperature control, and an automatic directional control. It shows the difference between the "faultproof" regulator and the actual regulator which is subject to faults, and develops this difference as far as possible in a parallel manner with regard to the control systems under consideration. Such as analysis affords, particularly in its extension to the faults of the actual regulator, a deep insight into the mechanism of the regulator process.

  9. The Comparison in Sister Carrie

    Institute of Scientific and Technical Information of China (English)



    本文主要分析小说《嘉莉妹妹》中对比手法的应用。首先对比分析了两种不同的美国社会生活方式——奢华和贫穷,然后主要对比了嘉莉的崛起和霍斯特伍德的衰落。%This article mainly analyzes the comparison in the novel.It firstly compares two different kinds of American social life—luxury and poverty,and then mainly comparatively analyzes Carrie’s rising and Hurstwood’s deterioration.

  10. RISKIND verification and benchmark comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Biwer, B.M.; Arnish, J.J.; Chen, S.Y.; Kamboj, S.


    This report presents verification calculations and benchmark comparisons for RISKIND, a computer code designed to estimate potential radiological consequences and health risks to individuals and the population from exposures associated with the transportation of spent nuclear fuel and other radioactive materials. Spreadsheet calculations were performed to verify the proper operation of the major options and calculational steps in RISKIND. The program is unique in that it combines a variety of well-established models into a comprehensive treatment for assessing risks from the transportation of radioactive materials. Benchmark comparisons with other validated codes that incorporate similar models were also performed. For instance, the external gamma and neutron dose rate curves for a shipping package estimated by RISKIND were compared with those estimated by using the RADTRAN 4 code and NUREG-0170 methodology. Atmospheric dispersion of released material and dose estimates from the GENII and CAP88-PC codes. Verification results have shown the program to be performing its intended function correctly. The benchmark results indicate that the predictions made by RISKIND are within acceptable limits when compared with predictions from similar existing models.

  11. Computational Chemistry Comparison and Benchmark Database (United States)

    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.

  12. The Timing of Social Comparison in Crowds (United States)


    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

  13. 2004■2005 Prices Comparison of Neodymia

    Institute of Scientific and Technical Information of China (English)


    Global NdFeB magnetic materials industry grows at over20% every year, strongly stimulating the production ofneodymia and Nd metal. In 2005, NdFeB in global market is3,000 - 4,000 tons short of supply. Prices comparison ofneodymia at the same period of this year and last year isshown in Table 1.Table 1 2004 2005 Prices Comparison of Neodymia2004■2005 Prices Comparison of Neodymia

  14. The distribution of interlaboratory comparison data

    DEFF Research Database (Denmark)

    Heydorn, Kaj


    The distribution of mutually consistent results from interlaboratory comparisons is expected to be leptokurtic, and readers are warned against accepting conclusions based on simulations assuming normality....

  15. The neural correlates of beauty comparison. (United States)

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


    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.

  16. Text Steganographic Approaches: A Comparison

    Directory of Open Access Journals (Sweden)

    Monika Agarwal


    Full Text Available This paper presents three novel approaches of text steganography. The first approach uses the theme ofmissing letter puzzle where each character of message is hidden by missing one or more letters in a wordof cover. The average Jaro score was found to be 0.95 indicating closer similarity between cover andstego file. The second approach hides a message in a wordlist where ASCII value of embedded characterdetermines length and starting letter of a word. The third approach conceals a message, withoutdegrading cover, by using start and end letter of words of the cover. For enhancing the security of secretmessage, the message is scrambled using one-time pad scheme before being concealed and cipher text isthen concealed in cover. We also present an empirical comparison of the proposed approaches with someof the popular text steganographic approaches and show that our approaches outperform the existingapproaches.

  17. MCNPX Model/Table Comparison

    Energy Technology Data Exchange (ETDEWEB)

    J.S. Hendricks


    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.

  18. Neuroticism and social comparison orientation as moderators of affective responses to social comparison at work

    NARCIS (Netherlands)

    Buunk, Abraham P.; Van der Zee, K.I.; Van Yperen, N.W.


    In a study among 72 nurses, the affective consequences of social comparison were examined and related to neuroticism, (N) and to social comparison orientation (SCO). Participants were confronted with a bogus interview with an upward versus a downward comparison target. Positive affect and identifica

  19. 16 CFR 233.2 - Retail price comparisons; comparable value comparisons. (United States)


    ... 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.... Expressed another way, if a number of the principal retail outlets in the area are regularly selling Brand...

  20. Electrogenic steps of light-driven proton transport in ESR, a retinal protein from Exiguobacterium sibiricum. (United States)

    Siletsky, Sergey A; Mamedov, Mahir D; Lukashev, Evgeniy P; Balashov, Sergei P; Dolgikh, Dmitriy A; Rubin, Andrei B; Kirpichnikov, Mikhail P; Petrovskaya, Lada E


    A retinal protein from Exiguobacterium sibiricum (ESR) functions as a light-driven proton pump. Unlike other proton pumps, it contains Lys96 instead of a usual carboxylic residue in the internal proton donor site. Nevertheless, the reprotonation of the Schiff base occurs fast, indicating that Lys96 facilitates proton transfer from the bulk. In this study we examined kinetics of light-induced transmembrane electrical potential difference, ΔΨ, generated in proteoliposomes reconstituted with ESR. We show that total magnitude of ΔΨ is comparable to that produced by bacteriorhodopsin but its kinetic components and their pH dependence are substantially different. The results are in agreement with the earlier finding that proton uptake precedes reprotonation of the Schiff base in ESR, suggesting that Lys96 is unprotonated in the initial state and gains a proton transiently in the photocycle. The electrogenic phases and the photocycle transitions related to proton transfer from the bulk to the Schiff base are pH dependent. At neutral pH, they occur with τ 0.5ms and 4.5ms. At alkaline pH, the fast component ceases and Schiff base reprotonation slows. At pH8.4, a spectrally silent electrogenic component with τ 0.25ms is detected, which can be attributed to proton transfer from the bulk to Lys96. At pH5.1, the amplitude of ΔΨ decreases 10 fold, reflecting a decreased yield and rate of proton transfer, apparently from protonation of the acceptor (Asp85-His57 pair) in the initial state. The features of the photoelectric potential generation correlate with the ESR structure and proposed mechanism of proton transfer.

  1. Optimal scaling of paired comparison data

    NARCIS (Netherlands)

    van de Velden, M.


    In this paper we consider the analysis of paired comparisons using optimal scaling techniques. In particular, we will, inspired by Guttman's approach for quantifying paired comparisons, formulate a new method to obtain optimal scaling values for the subjects. We will compare our results with those o

  2. Inter laboratory comparison on Industrial Computed Tomography

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo; Larsen, Erik

    The ‘CIA-CT comparison - Inter laboratory comparison on industrial Computed Tomography” is organized by DTU Department of Mechanical Engineering within the Danish project “Centre for Industrial Application of CT scanning - CIA-CT”. The project is co-financed by the Danish Ministry of Science, Tec...

  3. Social comparison and coping with cancer treatment

    NARCIS (Netherlands)

    Van der Zee, K; Buunk, B; Sanderman, R; Botke, G; van den Bergh, F


    In the present study scales were developed as indicators of four social comparison processes of respectively identification with others who are either doing better or worse and contrasting one's situation against the situation of either upward or downward comparison others. In a sample of 112 cancer

  4. The Language of Comparisons: Communicating about Percentages

    Directory of Open Access Journals (Sweden)

    Jessica Polito


    Full Text Available While comparisons between percentages or rates appear frequently in journalism and advertising, and are an essential component of quantitative writing, many students fail to understand precisely what percentages mean, and lack fluency with the language used for comparisons. After reviewing evidence demonstrating this weakness, this experience-based perspective lays out a framework for teaching the language of comparisons in a structured way, and illustrates it with several authentic examples that exemplify mistaken or misleading uses of such numbers. The framework includes three common types of erroneous or misleading quantitative writing: the missing comparison, where a key number is omitted; the apples-to-pineapples comparison, where two subtly incomparable rates are presented; and the implied fallacy, where an invalid quantitative conclusion is left to the reader to infer.

  5. The Current Status of Microscopical Hair Comparisons

    Directory of Open Access Journals (Sweden)

    Walter F. Rowe


    Full Text Available 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.


    Directory of Open Access Journals (Sweden)

    E. Hosseini Koupaie


    Full Text Available The main objective of present work was to compare the overall performances of "moving-bed" and "conventional" sequencing batch reactor. For this purpose, different experimental parameters including COD and dye concentration, turbidity, MLSS concentration, MLVSS/MLSS ratio, sludge volume index (SVI and Oxidation-Reduction Potential (ORP were calculated. One conventional sequencing batch reactor and three moving-bed sequencing batch reactors (MB-SBR were operated in this study. Each MB-SBR was equipped with a type of moving biofilm carrier. The results of dye, COD and turbidity analysis showed that there were no significant differences between the moving-bed and conventional sequencing batch reactors in the matters of effluent quality. A higher fluctuation of MLSS concentration and also higher SVI were observed in moving-bed compared to that of the conventional sequencing batch reactor. Higher ORP values which mean higher oxidation potential were measured in the reactors equipped with the moving carriers in comparison with those measured in the conventional sequencing batch reactor.

  7. RTU Comparison Calculator Enhancement Plan

    Energy Technology Data Exchange (ETDEWEB)

    Miller, James D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Weimin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Katipamula, Srinivas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)


    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.

  8. Distributed Wind Policy Comparison Tool

    Energy Technology Data Exchange (ETDEWEB)



    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.

  9. RTU Comparison Calculator Enhancement Plan

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  10. Inferior or superior : socials comparison in Dutch and Spanish organizations

    NARCIS (Netherlands)

    Carmona Rodriguez, Carmen


    SUMMARY Social comparison is an automatic and daily process through which individuals acquire information about themselves. Since Festinger (1954) postulated his assumptions on social comparison, extensive research has focused on understanding and explaining the social comparison process. In particu

  11. Micro Foundations for International Productivity Comparisons

    NARCIS (Netherlands)

    Gersbach, Hans; Ark, Bart van


    This paper describes the methodology and procedures of international comparisons of productivity levels for twelve manufacturing industries (producing food products, beer, soap and detergents, iron and steel, machine tools, various types of machinery, computers, audio and video equipment, industrial

  12. Educational differences in smoking: international comparison

    NARCIS (Netherlands)

    A.E.J.M. Cavelaars (Adrienne); N.K. Rasmussen; A.E. Kunst (Anton); J.J.M. Geurts (José); R. Crialesi; J.P. Mackenbach (Johan); L. Grotvedt; U. Helmert (Uwe); E. Lahelma; T. Spuhler; O. Lundberg; J. Matheson; M. do Rosario-Giraldes; A. Mielck; E. Regidor (Enrique)


    textabstractOBJECTIVE: To investigate international variations in smoking associated with educational level. DESIGN: International comparison of national health, or similar, surveys. SUBJECTS: Men and women aged 20 to 44 years and 45 to 74 years. SETTING: 12 European co

  13. Medicare Managed Care plan Performance, A Comparison... (United States)

    U.S. Department of Health & Human Services — The study evaluates the performance of Medicare managed care, Medicare Advantage, Plans in comparison to Medicare fee-for-service Plans in three states with...

  14. Adjusted indirect treatment comparisons of bioequivalence studies

    NARCIS (Netherlands)

    Gwaza, L


    Generic medicines are approved by regulatory authorities based on demonstration of bioequivalence with the innovator, however, current regulatory systems do not require direct comparison between all available generics of the same innovator to ensure interchangeability. As such, interchangeability be

  15. Comparison of Russian and IVS intensive series (United States)

    Kurdubov, S. L.


    The article presents results of first comparison the Russian National UT1-UTC estimation program Ru-U and IVS-intensive international campaign. It is shown that the Ru-U sessions are performing with good accuracy and results can be included into international VLBI data processing scheme. Comparison of different distributions shows that the problem of correlation lack between single delay formal errors and UT1 estimations are presented both in Ru-U and IVS-intensive series.

  16. A pathwise comparison result for parallel queues


    Moyal, Pascal


    We introduce the appropriate framework for pathwise comparison of multiple server queues under general stationary ergodic assumptions. We show in what sense it is better to have more servers for a system under FCFS ('First Come, First Served') or equivalently, more queues in a system of parallel queues under the JSW ('Join the Shortest Workload') allocation policy. This comparison result is based on the recursive representation of Kiefer and Wolfowitz, and on a non-mass conservative generaliz...

  17. A Group-Period Phase Comparison Method Based on Equivalent Phase Comparison Frequency

    Institute of Scientific and Technical Information of China (English)

    DU Bao-Qiang; ZHOU Wei; DONG Shao-Feng; ZHOU Hai-Niu


    Based on the principle of equivalent phase comparison frequency, we propose a group-period phase comparison method. This method can be used to reveal the inherent relations between periodic signals and the change laws of the phase difference. If these laws are applied in the processing of the mutual relations between frequency signals, phase comparison can be accomplished without frequency normalization. Experimental results show that the method can enhance the measurement resolution to 10-13/s in the time domain.

  18. Comparison of prokaryotic community structure from Mediterranean and Atlantic saltern concentrator ponds by a metagenomic approach

    Directory of Open Access Journals (Sweden)

    Ana Beatriz eFernández


    Full Text Available We analyzed the prokaryotic community structure of a saltern pond with 21 % total salts located in Isla Cristina, Huelva, Southwest Spain, close to the Atlantic ocean coast. For this purpose, we constructed a metagenome (designated as IC21 obtained by pyrosequencing consisting of 486 Mb with an average read length of 397 bp and compared it with other metagenomic datasets obtained from ponds with 19, 33 and 37 % total salts acquired from Santa Pola marine saltern, located in Alicante, East Spain, on the Mediterranean coast. Although the salinity in IC21 is closer to the pond with 19 % total salts from Santa Pola saltern (designated as SS19, IC21 is more similar at higher taxonomic levels to the pond with 33 % total salts from Santa Pola saltern (designated as SS33, since both are predominated by the phylum Euryarchaeota. However, there are significant differences at lower taxonomic levels where most sequences were related to the genus Halorubrum in IC21 and to Haloquadratum in SS33. Within the Bacteroidetes, the genus Psychroflexus is the most abundant in IC21 while Salinibacter dominates in SS33. Sequences related to bacteriorhodopsins and halorhodopsins correlate with the abundance of Haloquadratum in Santa Pola SS19 to SS33 and of Halorubrum in Isla Cristina IC21 dataset, respectively. Differences in composition might be attributed to local ecological conditions since IC21 showed a decrease in the number of sequences related to the synthesis of compatible solutes and in the utilization of phosphonate.

  19. Vibronic Dynamics of the Ultrafast all-trans to 13-cis Photoisomerization of Retinal in Channelrhodopsin-1. (United States)

    Schnedermann, Christoph; Muders, Vera; Ehrenberg, David; Schlesinger, Ramona; Kukura, Philipp; Heberle, Joachim


    Channelrhodopsins are light-gated ion channels with extensive applications in optogenetics. Channelrhodopsin-1 from Chlamydomonas augustae (CaChR1) exhibits a red-shifted absorption spectrum as compared to Channelrhodopsin-2, which is highly beneficial for optogenetic application. The primary event in the photocycle of CaChR1 involves an isomerization of the protein-bound retinal chromophore. Here, we apply highly time-resolved vibronic spectroscopy to reveal the electronic and structural dynamics associated with the first step of the photocycle of CaChR1. We observe vibrationally coherent formation of the P1 intermediate exhibiting a twisted 13-cis retinal with a 110 ± 7 fs time constant. Comparison with low-temperature resonance Raman spectroscopy of the corresponding trapped photoproduct demonstrates that this rapidly formed P1 intermediate is stable for several hundreds of nanoseconds.

  20. Rankings, Standards, and Competition: Task vs. Scale Comparisons (United States)

    Garcia, Stephen M.; Tor, Avishalom


    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…

  1. The role of comparison motives in the relationship between personality and comparison level choice

    NARCIS (Netherlands)

    Eggens, L.; Hendriks, A. A. J.; Bosker, R. J.; van der Werf, M. P. C.


    This article studied whether the motives for comparison of grades with those of others play a mediating role in the relationship between the Big Five personality traits and the choice of the level of comparison of students. The study was conducted among about 1,500 students in higher education. Of t

  2. Real medical benefit assessed by indirect comparison. (United States)

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


    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.

  3. Inter laboratory comparison on Industrial Computed Tomography

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo

    An interlaboratory comparison on industrial X-ray Computed Tomography (CT) was organized by the Centre for Geometrical Metrology (CGM), Department of Mechanical Engineering, Technical University of Denmark (DTU) and carried out within the project “Centre for Industrial Application of CT scanning...... - CIA-CT”. In the comparison, 27 laboratories from 8 countries were involved, and CT scanned two items selected among common industrial parts: a polymer part and a metal part. Altogether, 27 sets of items were circulated in parallel to the participants. Different measurands are considered, encompassing...... influence from the surrounding wall thickness on the measurement of roundness was documented for the metal item. The comparison shows that CT scanning on small industrial parts, generally speaking, is connected with uncertainties in the range 8-53 μm, as compared to an uncertainty range of 1.5-5.5 μm using...

  4. Evolution of rhodopsin ion pumps in haloarchaea

    Directory of Open Access Journals (Sweden)

    Ford Doolittle W


    Full Text Available Abstract Background The type 1 (microbial rhodopsins are a diverse group of photochemically reactive proteins that display a broad yet patchy distribution among the three domains of life. Recent work indicates that this pattern is likely the result of lateral gene transfer (LGT of rhodopsin genes between major lineages, and even across domain boundaries. Within the lineage in which the microbial rhodopsins were initially discovered, the haloarchaea, a similar patchy distribution is observed. In this initial study, we assess the roles of LGT and gene loss in the evolution of haloarchaeal rhodopsin ion pump genes, using phylogenetics and comparative genomics approaches. Results Mapping presence/absence of rhodopsins onto the phylogeny of the RNA polymerase B' subunit (RpoB' of the haloarchaea supports previous notions that rhodopsins are patchily distributed. The phylogeny for the bacteriorhodopsin (BR protein revealed two discrepancies in comparison to the RpoB' marker, while the halorhodopsin (HR tree showed incongruence to both markers. Comparative analyses of bacteriorhodopsin-linked regions of five haloarchaeal genomes supported relationships observed in the BR tree, and also identified two open reading frames (ORFs that were more frequently linked to the bacteriorhodopsin gene than those genes previously shown to be important to the function and expression of BR. Conclusion The evidence presented here reveals a complex evolutionary history for the haloarchaeal rhodopsins, with both LGT and gene loss contributing to the patchy distribution of rhodopsins within this group. Similarities between the BR and RpoB' phylogenies provide supportive evidence for the presence of bacteriorhodopsin in the last common ancestor of haloarchaea. Furthermore, two loci that we have designated bacterio-opsin associated chaperone (bac and bacterio-opsin associated protein (bap are inferred to have important roles in BR biogenesis based on frequent linkage and co

  5. Key comparison of liquid density standards (United States)

    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


    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 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).

  6. The Analysis of Semantic Comparisons in Translation

    Institute of Scientific and Technical Information of China (English)

    杨晨; 温雪娜


    As you all know,translation is an art that requires a lot of skills.Wide horizon,literature connotation and constant practice make a successful translator.And in translation we have to pay special attention to the semantic comparisons of different languages.This paper probes into the four features of comparisons between Chinese & English vocabulary,that is,coincidence,parallel,vacancy and conflict.At the same time,it explores how to deal with some problems in translation,too.

  7. Go Glocal: Intercultural Comparison of Leadership Ethics

    Directory of Open Access Journals (Sweden)

    Rafael Capurro


    Full Text Available This article deals with basic concepts of leadership based on the research of the French sinologist François Jullien. It addresses particularly the concept of efficacy in Greek thought in comparison with Daoist thought (Zhuangzi. This comparison is particularly relevant because classical Chinese philosophy developed over thousands of years with hardly any influence from the West. The spirit of Daoist strategic thinking is to avoid the trap of particularity by getting the opponent to adapt and keeping oneself open to adaptability. The moral price is a “logic of manipulation”. The shortcomings of this ethic is confronted with the Western quest for ethical principles and values.

  8. Risks of advanced technology - Nuclear: risk comparison

    Energy Technology Data Exchange (ETDEWEB)

    Latarjet, R. (Institut du Radium, Orsay (France))

    The author presents a general definition of the concept of risk and makes a distinction between the various types of risk - the absolute and the relative; the risk for oneself and for others. The quantitative comparison of risks presupposes their ''interchangeability''. In the case of major risks in the long term - or genotoxic risks - there is a certain degree of interchangeability which makes this quantitative comparison possible. It is expressed by the concept of rad-equivalence which the author defines and explains giving as a concrete example the work conducted on ethylene and ethylene oxide.

  9. Ordinal Welfare Comparisons with Multiple Discrete Indicators

    DEFF Research Database (Denmark)

    Arndt, Channing; Distante, Roberta; Hussain, M. Azhar;

    We develop an ordinal method for making welfare comparisons between populations with multidimensional discrete well-being indicators observed at the micro level. The approach assumes that, for each well-being indicator, the levels can be ranked from worse to better; however, no assumptions are ma...... another on the basis of available binary indicators by drawing upon linear programming theory. These approaches are applied to household survey data from Vietnam and Mozambique with a focus on child poverty comparisons over time and between regions....

  10. Comparison on Computed Tomography using industrial items

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo


    In a comparison involving 27 laboratories from 8 countries, measurements on two common industrial items, a polymer part and a metal part, were carried out using X-ray Computed Tomography. All items were measured using coordinate measuring machines before and after circulation, with reference...... measurement uncertainties in the range 1.5–5.5 μm, showing a good stability over the 6 months of the circulation. The comparison has shown that CT measurements on the industrial parts used lie in the range 6–53 μm, with maximum values up to 158 μm....

  11. Comparison of Temperature Loadings of Bridge Girders

    Directory of Open Access Journals (Sweden)

    J. Římal


    Full Text Available This paper compares the effect of temperature changes on the superstructure of bridges, above all the effect of non-uniform temperature. Loadings according to standards ESN 73 6203, ENV 1991-1-5 and DIN 1072 are compared here. The paper shows a short summary of temperature loading according to each standard and shows the comparison of bending moments arisen from these temperature loadings on superstructure made from continuous girder from a steel-concrete box girder with a composite concrete slab. With respect to a variety of design processes, the comparison is made without any coefficient of loading, combination or material. 

  12. The lifetimes of Pharaonis phoborhodopsin signaling states depend on the rates of proton transfers--effects of hydrostatic pressure and stopped flow experiments. (United States)

    Kikukawa, Takashi; Saha, Chabita K; Balashov, Sergei P; Imasheva, Eleonora S; Zaslavsky, Dmitry; Gennis, Robert B; Abe, Takayuki; Kamo, Naoki


    Pharaonis phoborhodopsin (ppR), a negative phototaxis receptor of Natronomonas pharaonis, undergoes photocycle similar to the light-driven proton pump bacteriorhodopsin (BR), but the turnover rate is much slower due to much longer lifetimes of the M and O intermediates. The M decay was shown to become as fast as it is in BR in the L40T/F86D mutant. We examined the effects of hydrostatic pressure on the decay of these intermediates. For BR, pressure decelerated M decay but slightly affected O decay. In contrast, with ppR and with its L40T/F86D mutant, pressure slightly affected M decay but accelerated O decay. Clearly, the pressure-dependent factors for M and O decay are different in BR and ppR. In order to examine the deprotonation of Asp75 in unphotolyzed ppR we performed stopped flow experiments. The pH jump-induced deprotonation of Asp75 occurred with 60 ms, which is at least 20 times slower than deprotonation of the equivalent Asp85 in BR and about 10-fold faster than the O decay of ppR. These data suggest that proton transfer is slowed not only in the cytoplasmic channel but also in the extracellular channel of ppR and that the light-induced structural changes in the O intermediate of ppR additionally decrease this rate.

  13. Lipidic cubic phase injector is a viable crystal delivery system for time-resolved serial crystallography. (United States)

    Nogly, Przemyslaw; Panneels, Valerie; Nelson, Garrett; Gati, Cornelius; Kimura, Tetsunari; Milne, Christopher; Milathianaki, Despina; Kubo, Minoru; Wu, Wenting; Conrad, Chelsie; Coe, Jesse; Bean, Richard; Zhao, Yun; Båth, Petra; Dods, Robert; Harimoorthy, Rajiv; Beyerlein, Kenneth R; Rheinberger, Jan; James, Daniel; DePonte, Daniel; Li, Chufeng; Sala, Leonardo; Williams, Garth J; Hunter, Mark S; Koglin, Jason E; Berntsen, Peter; Nango, Eriko; Iwata, So; Chapman, Henry N; Fromme, Petra; Frank, Matthias; Abela, Rafael; Boutet, Sébastien; Barty, Anton; White, Thomas A; Weierstall, Uwe; Spence, John; Neutze, Richard; Schertler, Gebhard; Standfuss, Jörg


    Serial femtosecond crystallography (SFX) using X-ray free-electron laser sources is an emerging method with considerable potential for time-resolved pump-probe experiments. Here we present a lipidic cubic phase SFX structure of the light-driven proton pump bacteriorhodopsin (bR) to 2.3 Å resolution and a method to investigate protein dynamics with modest sample requirement. Time-resolved SFX (TR-SFX) with a pump-probe delay of 1 ms yields difference Fourier maps compatible with the dark to M state transition of bR. Importantly, the method is very sample efficient and reduces sample consumption to about 1 mg per collected time point. Accumulation of M intermediate within the crystal lattice is confirmed by time-resolved visible absorption spectroscopy. This study provides an important step towards characterizing the complete photocycle dynamics of retinal proteins and demonstrates the feasibility of a sample efficient viscous medium jet for TR-SFX.

  14. Math Comparison. TEA Objectives/COMP. (United States)

    Rainwater, Marian; Owens, Mike

    Presented is a comparison of the Texas Education Agency Essential Objectives for Mathematics and the instructional concepts of the Conceptually Oriented Mathematics Program (COMP). COMP is a management program of 25 levels of mathematics instruction in 10 broad concept areas. Listed are relevant steps, levels, and strands of COMP for each of the…

  15. Comparison in religion: a methodological contribution

    NARCIS (Netherlands)

    Hermans, C.A.M.; Sterkens, C.J.A.


    How do we build theory on religion in cross-religious research? This article deals with four methodological issues in answering this question. What are the goals of cross-religious comparison? What is the object of cross-religious research? What kind of definition of religion is used in cross-religi

  16. Labels Facilitate Infants' Comparison of Action Goals

    NARCIS (Netherlands)

    Gerson, S.A.; Woodward, A.L.


    Understanding the actions of others depends on the insight that these actions are structured by intentional relations. In a number of conceptual domains, comparison with familiar instances has been shown to support children's and adults' ability to discern the relational structure of novel instances

  17. Privacy Preserving Mapping Schemes Supporting Comparison

    NARCIS (Netherlands)

    Tang, Qiang


    To cater to the privacy requirements in cloud computing, we introduce a new primitive, namely Privacy Preserving Mapping (PPM) schemes supporting comparison. An PPM scheme enables a user to map data items into images in such a way that, with a set of images, any entity can determine the $<, =, >$ re

  18. New directions in social comparison research

    NARCIS (Netherlands)

    Buunk, BP; Mussweiler, T


    This article notices that social comparison theory has developed from being a focused theoretical statement on the use of others for self-evaluation into a lively and varied area of research encompassing many different paradigms, approaches and applications. A recent 'renaissance' in social comparis

  19. Ranking health between countries in international comparisons

    DEFF Research Database (Denmark)

    Brønnum-Hansen, Henrik


    Cross-national comparisons and ranking of summary measures of population health sometimes give rise to inconsistent and diverging conclusions. In order to minimise confusion, international comparative studies ought to be based on well-harmonised data with common standards of definitions...

  20. A comparison of Monte Carlo generators

    CERN Document Server

    Golan, Tomasz


    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 $\\pi^+$ two-dimensional energy vs cosine distribution.

  1. The Comparisons between English and Chinese Vowels

    Institute of Scientific and Technical Information of China (English)



    English and Chinese have distinctive pronunciation systems. Usually, this kind of difference poses difficulties to language learners. Throughout the comparison between the two systems, students can get a general knowledge of their differences, which may help them to understand what causes their difficulties during pronunciation.

  2. Interlaboratory comparison of olfactometry in Japan. (United States)

    Higuchi, T; Masuda, J


    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.

  3. On Comparison of Rewriting and skopostheory

    Institute of Scientific and Technical Information of China (English)



    Andrew Lefevere and Hans Vermeer’ are outstanding figures in the history of translation studies.Their theory Rewriting and Skopostheory can be considered as milestone in their study history.This paper makes comparison between two theories with regard to their main features and makes persons-in-the-translation further get a deeper understanding of two theories.

  4. "Units of Comparison" across Languages, across Time (United States)

    Thomas, Margaret


    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. A Comparison between Saussure and Chomsky

    Institute of Scientific and Technical Information of China (English)



    Saussure and Chomsky are two important and influential figures in modern linguistics.Their achievements and contributiom endow them great order to understand their theories more profoundly and look for some.rlationship between them,this paper makes a plain comparison between Saussure and Chomsky based on reviewing their linguistic theories and generalizes some similarities and differences betwcen them.

  6. Comparison of mimo radar concepts: Detection performance

    NARCIS (Netherlands)

    Rossum, W.L. van; Huizing, A.G.


    In this paper, four different array radar concepts are compared: pencil beam, floodlight, monostatic MIMO, and multistatic MIMO. The array radar concepts show an increase in complexity accompanied by an increase in diversity. The comparison between the radar concepts is made by investigating the det

  7. The discovery and comparison of symbolic magnitudes. (United States)

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


    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.

  8. Comparison of energy performance requirements levels

    DEFF Research Database (Denmark)

    Spiekman, Marleen; Thomsen, Kirsten Engelund; Rose, Jørgen;

    the present Dutch requirement level (EPC) of 0,8 with the present Flemish level of E80, it can easily be seen that direct comparison is not possible. The conclusions and recommendations of the study are presented in part A. These constitute the most important result of the project. Part B gives an overview...

  9. Algorithmic parameterization of mixed treatment comparisons

    NARCIS (Netherlands)

    van Valkenhoef, Gert; Tervonen, Tommi; de Brock, Bert; Hillege, Hans


    Mixed Treatment Comparisons (MTCs) enable the simultaneous meta-analysis (data pooling) of networks of clinical trials comparing a parts per thousand yen2 alternative treatments. Inconsistency models are critical in MTC to assess the overall consistency between evidence sources. Only in the absence

  10. Multivariate normative comparisons using an aggregated database (United States)

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


    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

  11. Breaking the carboxyl rule: lysine 96 facilitates reprotonation of the Schiff base in the photocycle of a retinal protein from Exiguobacterium sibiricum. (United States)

    Balashov, Sergei P; Petrovskaya, Lada E; Imasheva, Eleonora S; Lukashev, Evgeniy P; Dioumaev, Andrei K; Wang, Jennifer M; Sychev, Sergey V; Dolgikh, Dmitriy A; Rubin, Andrei B; Kirpichnikov, Mikhail P; Lanyi, Janos K


    A lysine instead of the usual carboxyl group is in place of the internal proton donor to the retinal Schiff base in the light-driven proton pump of Exiguobacterium sibiricum (ESR). The involvement of this lysine in proton transfer is indicated by the finding that its substitution with alanine or other residues slows reprotonation of the Schiff base (decay of the M intermediate) by more than 2 orders of magnitude. In these mutants, the rate constant of the M decay linearly decreases with a decrease in proton concentration, as expected if reprotonation is limited by the uptake of a proton from the bulk. In wild type ESR, M decay is biphasic, and the rate constants are nearly pH-independent between pH 6 and 9. Proton uptake occurs after M formation but before M decay, which is especially evident in D2O and at high pH. Proton uptake is biphasic; the amplitude of the fast phase decreases with a pKa of 8.5 ± 0.3, which reflects the pKa of the donor during proton uptake. Similarly, the fraction of the faster component of M decay decreases and the slower one increases, with a pKa of 8.1 ± 0.2. The data therefore suggest that the reprotonation of the Schiff base in ESR is preceded by transient protonation of an initially unprotonated donor, which is probably the ε-amino group of Lys-96 or a water molecule in its vicinity, and it facilitates proton delivery from the bulk to the reaction center of the protein.

  12. A Photo-Labile Thioether Linkage to Phycoviolobilin Provides the Foundation for the Blue/Green Photocycles in DXCF-Cyanobacteriochromes

    Energy Technology Data Exchange (ETDEWEB)

    Burgie, E. Sethe [Univ. of Wisconsin, Madison, WI (United States); Walker, Joseph M. [Univ. of Wisconsin, Madison, WI (United States); Phillips Jr., George N. [Univ. of Wisconsin, Madison, WI (United States); Rice Univ., Houston, TX (United States); Vierstra, Richard D. [Univ. of Wisconsin, Madison, WI (United States)


    The phytochrome superfamily encompasses a diverse collection of photochromic photoreceptors in plants and microorganisms that employ a covalently linked bilin cradled in a cGMP-phosphodiesterase/adenylyl-cyclase/FhlA (GAF) domain to detect light. Whereas most interconvert between red- and far-red-light-absorbing states, cyanobacteria also express variants called cyanobacteriochromes (CBCRs) that modify bilin absorption to collectively perceive the entire visible spectrum. Here, we present two X-ray crystallographic structures of the GAF domain from the blue/green photochromic CBCR PixJ from Thermosynechococcus elongatus. Moreover, these structures confirm the hypothesis that CBCRs variably manipulate the chromophore π-conjugation system through isomerization and a second thioether linkage, in this case involving the bilin C10 carbon and Cys494 within a DXCF sequence characteristic of blue/green CBCRs. Biochemical studies support a mechanism for photoconversion whereby the second linkage ruptures on route to the green-light-absorbing state. All together, theTePixJ(GAF) models illustrate the remarkable structural and photochemical versatility among phytochromes and CBCRs in driving light perception.

  13. Supplementary comparison EURAMET.L-S22, calibration of gauge blocks by mechanical comparison (United States)

    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


    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 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).

  14. The relationship between social comparison processes and personality

    NARCIS (Netherlands)

    VanderZee, K; Buunk, B; Sanderman, R


    The relationship between social comparison processes and personality was examined in a sample of cancer patients (Study 1) and in a random population sample (Study 2). Previous studies showed that the need for comparison, its affective consequences and the tendency to make self-enhancing comparisons

  15. Affective response to social comparison in the classroom

    NARCIS (Netherlands)

    Buunk, Abraham (Bram); Kuyper, H.; Van der Zee, Y.G.


    In a study among 609 secondary school students, the affective reactions to social comparisons of grades were examined. Overall, the students reported more frequent responses to upward than to downward comparison, more identification than contrast in their comparisons, and more frequent responses imp

  16. The Performance versus Ability Distinction Following Social Comparison Feedback (United States)

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


    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…

  17. Comparison of fast discrete wavelet transform algorithms

    Institute of Scientific and Technical Information of China (English)

    MENG Shu-ping; TIAN Feng-chun; XU Xin


    This paper presents an analysis on and experimental comparison of several typical fast algorithms for discrete wavelet transform (DWT) and their implementation in image compression, particularly the Mallat algorithm, FFT-based algorithm, Short-length based algorithm and Lifting algorithm. The principles, structures and computational complexity of these algorithms are explored in details respectively. The results of the experiments for comparison are consistent to those simulated by MATLAB. It is found that there are limitations in the implementation of DWT. Some algorithms are workable only for special wavelet transform, lacking in generality. Above all, the speed of wavelet transform, as the governing element to the speed of image processing, is in fact the retarding factor for real-time image processing.

  18. A Comparison of Goniophotmetric Measurement Facilities

    DEFF Research Database (Denmark)

    Thorseth, Anders; Lindén, Johannes; Dam-Hansen, Carsten


    In this paper, we present the preliminary results of a comparison between widely different goniophotometric and goniospectroradiometric measurement facilities. The objective of the comparison is to increase consistency and clarify the capabilities among Danish test laboratories. The study will seek...... to find the degree of equivalence between the various facilities and methods. The collected data is compared by using a three-way variation of principal component analysis, which is well suited for modelling large sets of correlated data. This method drastically decreases the number of numerical values...... needed to represent the data. The model shows good agreement with data, while also highlighting the differences between the measurements. We conclude that the method could be useful for comparing large sets of goniophotometric data....

  19. Ontology for Genome Comparison and Genomic Rearrangements

    Directory of Open Access Journals (Sweden)

    Anil Wipat


    Full Text Available 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.

  20. Comparison of Different ECG Signals on MATLAB

    Directory of Open Access Journals (Sweden)

    Rajan Chaudhary


    Full Text Available In this paper we discuss about biomedical engineering and then a brief description of ECG signal. We have generated a new method to compare different arrhythmic heart signals with normal sinus signals at MATLAB. This is making the comparison very easy. ECG is used to measure the rate and regularity of heartbeats, as well as the position and size of the chambers, the existence of any damage to the heart, and the effects of devices or drugs used to regulate the heart, such as a pacemaker. Uttermost ECGs are performed for diagnostic or research purposes on human hearts, but may also be performed on heart of animals, usually for diagnosis of heart abnormalities or research. Result obtained showing that Comparison of Normal (Sinus and Abnormal (arrhythmia ECG signal. Through this method we can compare any type of disordered signal of heart.

  1. Bayesian Model comparison of Higgs couplings

    CERN Document Server

    Bergstrom, Johannes


    We investigate the possibility of contributions from physics beyond the Standard Model (SM) to the Higgs couplings, in the light of the LHC data. The work is performed within an interim framework where the magnitude of the Higgs production and decay rates are rescaled though Higgs coupling scale factors. We perform Bayesian parameter inference on these scale factors, concluding that there is good compatibility with the SM. Furthermore, we carry out Bayesian model comparison on all models where any combination of scale factors can differ from their SM values and find that typically models with fewer free couplings are strongly favoured. We consider the evidence that each coupling individually equals the SM value, making the minimal assumptions on the other couplings. Finally, we make a comparison of the SM against a single "not-SM" model, and find that there is moderate to strong evidence for the SM.

  2. A comparison of goniophotometric measurement facilities

    DEFF Research Database (Denmark)

    Thorseth, Anders; Lindén, Johannes; Dam-Hansen, Carsten


    In this paper, we present the preliminary results of a comparison between widely different goniophotometric and goniospectroradiometric measurement facilities. The objective of the comparison is to increase consistency and clarify the capabilities among Danish test laboratories. The study will seek...... to find the degree of equivalence between the various facilities and methods. The collected data is compared by using a three-way variation of principal component analysis, which is well suited for modelling large sets of correlated data. This method drastically decreases the number of numerical values...... needed to represent the data. The model shows good agreement with data, while also highlighting the differences between the measurements. We conclude that the method could be useful for comparing large sets of goniophotometric data....

  3. Bayesian hypothesis testing for key comparisons (United States)

    Wübbeler, Gerd; Bodnar, Olha; Elster, Clemens


    Unilateral degrees of equivalence are the key result in the analysis of key comparison data and they are used to approve, or disapprove, calibration and measurement capabilities of the participating laboratories. To this end, it is checked whether a degree of equivalence differs significantly from zero. Proceeding in such a way can be viewed as carrying out a classical hypothesis test. We develop a Bayesian counterpart to this approach which has the advantage that it can include prior assessment of the corresponding Consultative Committee about the calibration and measurement capabilities of the participating laboratories. Simple expressions are derived and their implementation is provided in terms of MATLAB® and R programs. The novel procedure is illustrated by its application to two recent key comparisons CCL-K1 and CCM.FF-K4.1.2011.

  4. Ordinal Welfare Comparisons with Multiple Discrete Indicators

    DEFF Research Database (Denmark)

    Arndt, Channing; Distante, Roberta; Hussain, M. Azhar

    We develop an ordinal method for making welfare comparisons between populations with multidimensional discrete well-being indicators observed at the micro level. The approach assumes that, for each well-being indicator, the levels can be ranked from worse to better; however, no assumptions are made...... about relative importance of any dimension nor about complementarity/substitutability relationships between dimensions. The method is based on the concept of multidimensional first order dominance. We introduce a rapid and reliable algorithm for empirically determining whether one population dominates...... another on the basis of available binary indicators by drawing upon linear programming theory. These approaches are applied to household survey data from Vietnam and Mozambique with a focus on child poverty comparisons over time and between regions....

  5. Visual comparison testing of automotive paint simulation (United States)

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


    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.

  6. Supplier Evaluation Process by Pairwise Comparisons

    Directory of Open Access Journals (Sweden)

    Arkadiusz Kawa


    Full Text Available We propose to assess suppliers by using consistency-driven pairwise comparisons for tangible and intangible criteria. The tangible criteria are simpler to compare (e.g., the price of a service is lower than that of another service with identical characteristics. Intangible criteria are more difficult to assess. The proposed model combines assessments of both types of criteria. The main contribution of this paper is the presentation of an extension framework for the selection of suppliers in a procurement process. The final weights are computed from relative pairwise comparisons. For the needs of the paper, surveys were conducted among Polish managers dealing with cooperation with suppliers in their enterprises. The Polish practice and restricted bidding are discussed, too.

  7. Traditional marketing vs. Internet marketing. A comparison


    Varfan, Mona; Shima, Alfa


    Title: Traditional marketing vs. Internet marketing: A comparison Problem: Marketing is an important strategy for businesses and it contains numerous effective tools. Traditional marketing has been in use for many years and nowadays Internet has brought new ways of doing business for companies and that has affected marketing. What are the main differences between Internet marketing and traditional marketing? Which one of the two approaches contains the most used and effective marketing tools ...

  8. BMX bicycles: accident comparison with other models.



    A comparison has been made between BMX bicycle accidents and those occurring when children ride other types of bicycle. The injuries sustained are compared to see if the clinical impressions that BMX are more dangerous, and produce more facial injuries, are correct. This was found not to be true as half the children involved rode BMX bicycles, and the injuries sustained were similar to those occurring to non BMX riders. BMX riders had a lower proportion of serious injuries than riders of raci...

  9. Are all Linear Paired Comparison Models Equivalent (United States)


    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

  10. comparison of english and chinese advertisement slogan

    Institute of Scientific and Technical Information of China (English)



    advertisements in cross-culture communication come from different cultural background.the english and chinese advertisement slogan is a lively and distinctive field.differences of advertising slogan are becoming more important in the context of economic globalization.this paper,from the comparison of chinese and english advertisement slogan,language used in slogans,translation of slogan,mainly from the points of view of cross-culture to analysis the differences of tow language ads slogan.

  11. Comparison of cloud models for Brown Dwarfs

    CERN Document Server

    Helling, Ch; Allard, F; Dehn, M; Hauschildt, P; Homeier, D; Lodders, K; Marley, M; Rietmeijer, F; Tsuji, T; Woitke, P


    A test case comparison is presented for different dust cloud model approaches applied in brown dwarfs and giant gas planets. We aim to achieve more transparency in evaluating the uncertainty inherent to theoretical modelling. We show in how far model results for characteristic dust quantities vary due to different assumptions. We also demonstrate differences in the spectral energy distributions resulting from our individual cloud modelling in 1D substellar atmosphere simulations

  12. Comparison of time to detect definitions


    Dubois, Laurence M.


    Approved for public release; distribution is unlimited This thesis concerns the measurement of times to detect multiple targets. It compares two common definitions of times to detection--interdetection time, and search time to detection--to a relatively new definition called time in field-of-view until detection. This comparison uses the data from the Thermal Pinpoint Test conducted from July to December 1983. Detection time distributions and mean times to detection were studied, lookin...

  13. Explosive Infrasonic Events: Sensor Comparison Experiment (SCE)

    Energy Technology Data Exchange (ETDEWEB)

    Schnurr, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Garces, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rodgers, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)


    SCE (sensor comparison experiment) 1 through 4 consists of a series of four controlled above-ground explosions designed to provide new data for overpressure propagation. Infrasound data were collected by LLNL iPhones and other sensors. Origin times, locations HOB, and yields are not being released at this time and are therefore not included in this report. This preliminary report will be updated as access to additional data changes, or instrument responses are determined.

  14. Comparison of Chinese and American wine culture

    Institute of Scientific and Technical Information of China (English)



    Wine which has a long history in human life and culture is not only a kind of objectively existing material but also a cultural symbol.In this thesis, it will focus on the comparison between Chinese and American wine culture.Four aspects will be included:the origin of wine;the various types of wine;the etiquette of wine drinking;the connection between wine culture and arts and humanities.

  15. Supercomputers and biological sequence comparison algorithms. (United States)

    Core, N G; Edmiston, E W; Saltz, J H; Smith, R M


    Comparison of biological (DNA or protein) sequences provides insight into molecular structure, function, and homology and is increasingly important as the available databases become larger and more numerous. One method of increasing the speed of the calculations is to perform them in parallel. We present the results of initial investigations using two dynamic programming algorithms on the Intel iPSC hypercube and the Connection Machine as well as an inexpensive, heuristically-based algorithm on the Encore Multimax.

  16. ORAM and shutdown PRA comparison study

    Energy Technology Data Exchange (ETDEWEB)

    He, W.G.; Hilsmeier, Todd; Carrier, Tom [PSE and G, Salem, NJ (United States)


    A comparison study between results obtained from an Outage Risk Assessment and Management (ORAM) model and a shutdown Probabilistic Risk Analysis (PRA) model was conducted. The purpose of the study was to provide useful risk information for better outage planning by focusing resources and contingency plans on risk significant configurations. The comparison study used selected configurations from the 8th refueling outage of the Hope Creek Generation Station (HCGS), a Boiling Water Reactor (BWR). A total of Eleven configurations were compared. Three configurations were selected to evaluate the impact of the Service Water System during the early stage of a refueling outage. (There are existing studies suggesting that the designed redundancy of Service Water Systems is needed during the early stage of a shutdown.) Four configurations were selected because they were deemed risk significant by the ORAM analysis. (For configurations deemed risk significant by ORAM results, compensatory actions have been taken and contingency plans have been developed to mitigate potential deviations from the configuration. The shutdown PRA was used to evaluate the necessity and effectiveness of these contingency plans and compensatory actions.) To increase the comparison population, an additional four configurations were randomly selected. Thus, a total of 15 configurations were evaluated by the shutdown PRA, and a total of 11 configurations were studied by the ORAM. (author)

  17. Hydraulic fracture model comparison study: Complete results

    Energy Technology Data Exchange (ETDEWEB)

    Warpinski, N.R. [Sandia National Labs., Albuquerque, NM (United States); Abou-Sayed, I.S. [Mobil Exploration and Production Services (United States); Moschovidis, Z. [Amoco Production Co. (US); Parker, C. [CONOCO (US)


    Large quantities of natural gas exist in low permeability reservoirs throughout the US. Characteristics of these reservoirs, however, make production difficult and often economic and stimulation is required. Because of the diversity of application, hydraulic fracture design models must be able to account for widely varying rock properties, reservoir properties, in situ stresses, fracturing fluids, and proppant loads. As a result, fracture simulation has emerged as a highly complex endeavor that must be able to describe many different physical processes. The objective of this study was to develop a comparative study of hydraulic-fracture simulators in order to provide stimulation engineers with the necessary information to make rational decisions on the type of models most suited for their needs. This report compares the fracture modeling results of twelve different simulators, some of them run in different modes for eight separate design cases. Comparisons of length, width, height, net pressure, maximum width at the wellbore, average width at the wellbore, and average width in the fracture have been made, both for the final geometry and as a function of time. For the models in this study, differences in fracture length, height and width are often greater than a factor of two. In addition, several comparisons of the same model with different options show a large variability in model output depending upon the options chosen. Two comparisons were made of the same model run by different companies; in both cases the agreement was good. 41 refs., 54 figs., 83 tabs.

  18. The politics of comparison in mediated publics

    DEFF Research Database (Denmark)

    Birkbak, Andreas

    these comparative practices are different, or do we focus on how they interlink? I argue that if we want to learn from the comparative work being done with media, the politics of linkages is more interesting. In the paper, I try to demonstrate empirically what is at stake in these politics of comparisons through......News media and social media are often compared in a way that focuses on their contrasts, e.g. as between objective news and passionate opinions – or between a clear-cut public and multiple issue-oriented quasi-publics. If we do not assume such divisions to be pre-given, it becomes possible to study...... how the contrast is enacted through the media’s own comparative practices that produce navigable pluralities of ’news’ or ’opinions’. Paying attention to media as comparative devices thus turns comparative media studies into a comparison of comparisons. Here is a choice: Do we focus on how...

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  20. PROMPT: a protein mapping and comparison tool

    Directory of Open Access Journals (Sweden)

    Frishman Dmitrij


    Full Text Available Abstract Background Comparison of large protein datasets has become a standard task in bioinformatics. Typically researchers wish to know whether one group of proteins is significantly enriched in certain annotation attributes or sequence properties compared to another group, and whether this enrichment is statistically significant. In order to conduct such comparisons it is often required to integrate molecular sequence data and experimental information from disparate incompatible sources. While many specialized programs exist for comparisons of this kind in individual problem domains, such as expression data analysis, no generic software solution capable of addressing a wide spectrum of routine tasks in comparative proteomics is currently available. Results PROMPT is a comprehensive bioinformatics software environment which enables the user to compare arbitrary protein sequence sets, revealing statistically significant differences in their annotation features. It allows automatic retrieval and integration of data from a multitude of molecular biological databases as well as from a custom XML format. Similarity-based mapping of sequence IDs makes it possible to link experimental information obtained from different sources despite discrepancies in gene identifiers and minor sequence variation. PROMPT provides a full set of statistical procedures to address the following four use cases: i comparison of the frequencies of categorical annotations between two sets, ii enrichment of nominal features in one set with respect to another one, iii comparison of numeric distributions, and iv correlation of numeric variables. Analysis results can be visualized in the form of plots and spreadsheets and exported in various formats, including Microsoft Excel. Conclusion PROMPT is a versatile, platform-independent, easily expandable, stand-alone application designed to be a practical workhorse in analysing and mining protein sequences and associated annotation

  1. Comparison of real development levels of countries: Genesis and perspectives

    Directory of Open Access Journals (Sweden)

    Prekajac Zora


    Full Text Available Comparison of levels of development among countries is usually done by reducing values in national currencies with a common denominator, using the official exchange rate. Because of its unreality, the values calculated in this way do not illustrate real relations between compared countries. That brings about the launching of the UN International Comparison Project (latter Programme with two fold aims: developing a method for international comparison of real domestic product which could be applied to a number of very heterogeneous countries, and the comparison of growing number of very different countries. Until now six phases of comparisons are finished. Taking into consideration problems that appeared in the realization of the VI ICP phase as well as quality improvement proposals, a decision has been made to launch a new, global round for 2003-2006. Comparison will cover 150 countries (the widest coverage ever. This will give global character to the comparison, which was the end cause of the ICP.

  2. Physical appearance comparisons in ethnically diverse college women. (United States)

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


    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.


    Directory of Open Access Journals (Sweden)

    Liliana liliana


    Full Text Available In computer graphics applications, to produce realistic images, a method that is often used is ray tracing. Ray tracing does not only model local illumination but also global illumination. Local illumination count ambient, diffuse and specular effects only, but global illumination also count mirroring and transparency. Local illumination count effects from the lamp(s but global illumination count effects from other object(s too. Objects that are usually modeled are primitive objects and mesh objects. The advantage of mesh modeling is various, interesting and real-like shape. Mesh contains many primitive objects like triangle or square (rare. A problem in mesh object modeling is long rendering time. It is because every ray must be checked with a lot of triangle of the mesh. Added by ray from other objects checking, the number of ray that traced will increase. It causes the increasing of rendering time. To solve this problem, in this research, new methods are developed to make the rendering process of mesh object faster. The new methods are angle comparison and distance comparison. These methods are used to reduce the number of ray checking. The rays predicted will not intersect with the mesh, are not checked weather the ray intersects the mesh. With angle comparison, if using small angle to compare, the rendering process will be fast. This method has disadvantage, if the shape of each triangle is big, some triangles will be corrupted. If the angle to compare is bigger, mesh corruption can be avoided but the rendering time will be longer than without comparison. With distance comparison, the rendering time is less than without comparison, and no triangle will be corrupted.

  4. Comparison of properties of digital spectrometer systems. (United States)

    Mazanova, Monika; Dryak, Pavel; Kovar, Petr; Auerbach, Pavel


    We have tested two digital spectrometer systems, the DSP 9660 and Lynx(®) modules, connected to a HPGe detector. Lynx(®) is a fully integrated 32K channel signal analyzer based on digital signal processing techniques, which offers advanced digital stabilization. The model DSP 9660 digitalizes the signal directly at a very high sampling rate. The evaluated properties were integral nonlinearity, differential linearity, channel profiles, resolution and throughput. We found that the DSP system has slightly inferior resolution and throughput in comparison with the Lynx(®) system.

  5. Rooftop Unit Comparison Calculator User Manual

    Energy Technology Data Exchange (ETDEWEB)

    Miller, James D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)


    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.

  6. Comparison of Shallow Survey 2012 Multibeam Datasets (United States)

    Ramirez, T. M.


    The purpose of the Shallow Survey common dataset is a comparison of the different technologies utilized for data acquisition in the shallow survey marine environment. The common dataset consists of a series of surveys conducted over a common area of seabed using a variety of systems. It provides equipment manufacturers the opportunity to showcase their latest systems while giving hydrographic researchers and scientists a chance to test their latest algorithms on the dataset so that rigorous comparisons can be made. Five companies collected data for the Common Dataset in the Wellington Harbor area in New Zealand between May 2010 and May 2011; including Kongsberg, Reson, R2Sonic, GeoAcoustics, and Applied Acoustics. The Wellington harbor and surrounding coastal area was selected since it has a number of well-defined features, including the HMNZS South Seas and HMNZS Wellington wrecks, an armored seawall constructed of Tetrapods and Akmons, aquifers, wharves and marinas. The seabed inside the harbor basin is largely fine-grained sediment, with gravel and reefs around the coast. The area outside the harbor on the southern coast is an active environment, with moving sand and exposed reefs. A marine reserve is also in this area. For consistency between datasets, the coastal research vessel R/V Ikatere and crew were used for all surveys conducted for the common dataset. Using Triton's Perspective processing software multibeam datasets collected for the Shallow Survey were processed for detail analysis. Datasets from each sonar manufacturer were processed using the CUBE algorithm developed by the Center for Coastal and Ocean Mapping/Joint Hydrographic Center (CCOM/JHC). Each dataset was gridded at 0.5 and 1.0 meter resolutions for cross comparison and compliance with International Hydrographic Organization (IHO) requirements. Detailed comparisons were made of equipment specifications (transmit frequency, number of beams, beam width), data density, total uncertainty, and

  7. A comparison of thermal zone aggregation methods

    Energy Technology Data Exchange (ETDEWEB)

    Dobbs, Justin R. [Cornell University; Hencey, Brandon M. [Cornell University


    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.

  8. Intercode comparison of gyrokinetic global electromagnetic modes (United States)

    Görler, T.; Tronko, N.; Hornsby, W. A.; Bottino, A.; Kleiber, R.; Norscini, C.; Grandgirard, V.; Jenko, F.; Sonnendrücker, E.


    Aiming to fill a corresponding lack of sophisticated test cases for global electromagnetic gyrokinetic codes, a new hierarchical benchmark is proposed. Starting from established test sets with adiabatic electrons, fully gyrokinetic electrons, and electrostatic fluctuations are taken into account before finally studying the global electromagnetic micro-instabilities. Results from up to five codes involving representatives from different numerical approaches as particle-in-cell methods, Eulerian and Semi-Lagrangian are shown. By means of spectrally resolved growth rates and frequencies and mode structure comparisons, agreement can be confirmed on ion-gyro-radius scales, thus providing confidence in the correct implementation of the underlying equations.


    Directory of Open Access Journals (Sweden)



    Full Text Available Ship squat is a combined effect of ship’s draft and trim increase due to ship motion in limited navigation conditions. Over time, researchers conducted tests on models and ships to find a mathematical formula that can define squat. Various forms of calculating squat can be found in the literature. Among those most commonly used are of Barrass, Millward, Eryuzlu or ICORELS. This paper presents a comparison between the squat formulas to see the differences between them and which one provides the most satisfactory results. In this respect a cargo ship at different speeds was considered as a model for maximum squat calculations in canal navigation conditions.

  10. Quantum Private Comparison Protocol with Linear Optics (United States)

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


    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.

  11. Comparison of different Fingerprint Compression Techniques

    Directory of Open Access Journals (Sweden)

    Ms.Mansi Kambli


    Full Text Available The important features of wavelet transform and different methods in compression of fingerprint images have been implemented. Image quality is measured objectively using peak signal to noise ratio (PSNR and mean square error (MSE.A comparative study using discrete cosine transform based Joint Photographic Experts Group(JPEG standard , wavelet based basic Set Partitioning in Hierarchical trees(SPIHT and Modified SPIHT is done. The comparison shows that Modified SPIHT offers better compression than basic SPIHT and JPEG. The results will help application developers to choose a good wavelet compression system for their applications.

  12. The interaction between purple membrane and membrane lipid

    Institute of Scientific and Technical Information of China (English)


    Bacteriorhodopsin in purple membrane was reconstituted into different lipid vesicles. The effect of three different lipids on the structure and function of bacteriorhodopsin in lipid vesicles was studied by the observation on freeze-fracture eletron microscopy, the rotational diffusion of bacteriorhodopsin in lipid vesicles, the measurement of absorption spectrum, and the absorbance change with time. For these prepared samples, the results showed that DMPC was the stable lipid environment of bacteriorhodopsin; egg-pc causeed the loss of retinal chromophore of bacteriorhodopsin and it was not reversible change, cholesterol could stabilize the bacteriorhodopsin in lipid environment,but it caused the aggregation of bacteriorhodopsin.

  13. Isolation and characterization of a novel strain of Natrinema containing a bop gene

    Institute of Scientific and Technical Information of China (English)

    XU Xue-wei; WU Min; HUANG Wei-da


    A novel member of extremely halophilic archaea, strain AJ2, was isolated from Ayakekum Lake located in Altun Mountain National Nature Reserve of Xinjiang Uygur Autonomous Region in China. The strain A J2 requires at least 10% (w/v)NaCl and grows 10% to 30% (optimum at 20%). Phylogenetic analysis based on 16S rDNA sequence comparison revealed that strain A J2 clustered to three Natrinema species with less than 97.7% sequence similarities, suggesting A J2 is a novel member of Natrinema. A bacteriorhodopsin-encoding (bop) gene was subsequently detected in the A J2 genome using the polymerase chain reaction technique. The cloning and sequencing of a 401 base pairs fragment indicated the deduced amino acid sequence of bop from A J2 is different from that reported for bacteriorhodopsins. This is the first reported detection of a bop gene in Natrinema.

  14. Individual differences on social comparison : properties of the orientation Spanish scale towards social comparison

    NARCIS (Netherlands)

    Buunk, AP; Belmonte, J; Peiro, JM; Zurriaga, R; Gibbons, FX


    This paper describes the development and the properties of the INCOM-E, the Spanish language version of the INCOM, a measure to assess individual differences in social comparison orientation that was originally developed simultaneously in English and in Dutch. In both Study 1 (including 212 students

  15. Effects of Comparison Question Type and Between Test Stimulation on the Validity of Comparison Question Test (United States)


    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

  16. Comparison of Fast Neutron Detector Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Stange, Sy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mckigney, Edward Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    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.

  17. Multiple comparison analysis testing in ANOVA. (United States)

    McHugh, Mary L


    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.

  18. Comparison of Different Implementations of MFCC

    Institute of Scientific and Technical Information of China (English)

    ZHENG Fang; ZHANG Guoliang; SONG Zhanjiang


    The performance of the Mel-Frequency Cepstrum Coefficients (MFCC) may be affected by (1) the number of filters, (2) the shape of filters, (3) the way in which filters are spaced, and (4) the way in which the power spectrum is warped. In this paper, several comparison experiments are done to find a best implementation. The traditional MFCC calculation excludes the 0th coefficient for the reason that it is regarded as somewhat unreliable. According to the analysis and experiments, the authors find that it can be regarded as the generalized frequency band energy (FBE) and is hence useful, which results in the FBE-MFCC. The authors also propose a better analysis, namely the auto-regressive analysis, on the frame energy,which outperforms its 1st and/or 2nd order differential derivatives. Experiments with the “863”Speech Database show that, compared with the traditional MFCC with its corresponding autoregressive analysis coefficients, the FBE-MFCC and the frame energy with their corresponding auto-regressive analysis coefficients form the best combination, reducing the Chinese syllable error rate (CSER) by about 10%, while the FBE-MFCC with the corresponding auto-regressive analysis coefficients reduces CSER by 2.5%. Comparison experiments are also done with a quite casual Chinese speech database, named Chinese Annotated Spontaneous Speech (CASS)corpus. The FBE-MFCC can reduce the error rate by about 2.9% on an average.

  19. SUPPLEMENTARY COMPARISON: Final report on Supplementary Comparison APMP.M.H-S1 (United States)

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


    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

  20. Final report on CCM key comparison CCM.D-K2: Comparison of liquid density standards (United States)

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


    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

  1. A comparison of packaged piezoactuators for industrial applications (United States)

    Pretorius, Jaco; Hugo, Marius; Spangler, Ronald L., Jr.


    A comparison of different commercially available packaged piezoelectric actuators is presented. The comparisons are based on force, stress and strain performance at similar field densities. A new metric of comparison, based on energy efficiency, is introduced. This paper provides designers with useful information on actuators and actuator performance for industrial applications. The QuickPack and PowerAct actuators remain the only packaged piezoelectric actuators to be produced in high volume and to feature in commercial applications.

  2. PR Personnel and Print Journalists: A Comparison of Professionalism (United States)

    Nayman, Oguz; And Others


    Reports on a comparison of Colorado public relations personnel and newspaper journalists, which focused on demographic characteristics, professional orientation, job satisfaction, and attitude toward professional improvement. (GW)

  3. Comparison of Present SST Gravity Field Models

    Institute of Scientific and Technical Information of China (English)

    LUO Jia; SHI Chuang; ZOU Xiancai; WANG Haihong


    Taking the main land of Europe as the region to be studied, the potential of the new satellite gravity technique: satellite-to-satellite tracking (SST) and improving the accuracy of regional gravity field model with the SST models are investigated. The drawbacks of these models are discussed. With GPM98C as the reference, the gravity anomaly residuals of several other models, the latest SST global gravity field models (EIGEN series and GGM series), were computed and compared. The results of the comparison show that in the selected region, some systematic errors with periodical properties exist in the EIGEN and GGM's S series models in the high degree and order. Some information that was not shown in the classic gravity models is detected in the low and middle degree and order of EIGEN and GGM's S series models. At last, the effective maximum degrees and orders of SST models are suggested.

  4. Illicit drug profiling, reflection on statistical comparisons. (United States)

    Esseiva, Pierre; Gaste, Laeticia; Alvarez, Daniel; Anglada, Frederic


    This paper presents reflexions about statistical considerations on illicit drug profiling and more specifically about the calculation of threshold for determining of the seizure are linked or not. The specific case of heroin and cocaine profiling is presented with the necessary details on the target profiling variables (major alkaloids) selected and the analytical method used. Statistical approach to compare illicit drug seizures is also presented with the introduction of different scenarios dealing with different data pre-treatment or transformation of variables. The main aim consists to demonstrate the influence of data pre-treatment on the statistical outputs. A thorough study of the evolution of the true positive rate (TP) and the false positive rate (FP) in heroin and cocaine comparison is then proposed to investigate this specific topic and to demonstrate that there is no universal approach available and that the calculations have to be revaluate for each new specific application.

  5. Algebraic comparison of partial lists in bioinformatics.

    Directory of Open Access Journals (Sweden)

    Giuseppe Jurman

    Full Text Available The outcome of a functional genomics pipeline is usually a partial list of genomic features, ranked by their relevance in modelling biological phenotype in terms of a classification or regression model. Due to resampling protocols or to a meta-analysis comparison, it is often the case that sets of alternative feature lists (possibly of different lengths are obtained, instead of just one list. Here we introduce a method, based on permutations, for studying the variability between lists ("list stability" in the case of lists of unequal length. We provide algorithms evaluating stability for lists embedded in the full feature set or just limited to the features occurring in the partial lists. The method is demonstrated by finding and comparing gene profiles on a large prostate cancer dataset, consisting of two cohorts of patients from different countries, for a total of 455 samples.

  6. Performance Comparison of Active Queue Management Techniques

    Directory of Open Access Journals (Sweden)

    T. B. Reddy


    Full Text Available Congestion is an important issue which researchers focus on in the Transmission Control Protocol (TCP network environment. To keep the stability of the whole network, congestion control algorithms have been extensively studied. Queue management method employed by the routers is one of the important issues in the congestion control study. Active Queue Management (AQM has been proposed as a router-based mechanism for early detection of congestion inside the network. In this study, we are comparing AQM two popular queue management methods, Random Early Detection (RED and droptail, in different aspects, such as throughput and fairness Index. The comparison results indicate RED performed slightly better with higher throughput and higher fairness Index than droptail. Simulation is done by using Network Simulator (NS2 and the graphs are drawn using X- graph.

  7. A Comparison of Different Machine Transliteration Models

    CERN Document Server

    Choi, K; Oh, J; 10.1613/jair.1999


    Machine transliteration is a method for automatically converting words in one language into phonetically equivalent ones in another language. Machine transliteration plays an important role in natural language applications such as information retrieval and machine translation, especially for handling proper nouns and technical terms. Four machine transliteration models -- grapheme-based transliteration model, phoneme-based transliteration model, hybrid transliteration model, and correspondence-based transliteration model -- have been proposed by several researchers. To date, however, there has been little research on a framework in which multiple transliteration models can operate simultaneously. Furthermore, there has been no comparison of the four models within the same framework and using the same data. We addressed these problems by 1) modeling the four models within the same framework, 2) comparing them under the same conditions, and 3) developing a way to improve machine transliteration through this com...

  8. Comparison of select reference management tools. (United States)

    Zhang, Yingting


    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.

  9. The Frontier Fields Lens Modeling Comparison Project

    CERN Document Server

    Meneghetti, M; Coe, D; Contini, E; De Lucia, G; Giocoli, C; Acebron, A; Borgani, S; Bradac, M; Diego, J M; Hoag, A; Ishigaki, M; Johnson, T L; Jullo, E; Kawamata, R; Lam, D; Limousin, M; Liesenborgs, J; Oguri, M; Sebesta, K; Sharon, K; Williams, L L R; Zitrin, A


    Gravitational lensing by clusters of galaxies offers a powerful probe of their structure and mass distribution. Deriving a lens magnification map for a galaxy cluster is a classic inversion problem and many methods have been developed over the past two decades to solve it. Several research groups have developed techniques independently to map the predominantly dark matter distribution in cluster lenses. While these methods have all provided remarkably high precision mass maps, particularly with exquisite imaging data from the Hubble Space Telescope (HST), the reconstructions themselves have never been directly compared. In this paper, we report the results of comparing various independent lens modeling techniques employed by individual research groups in the community. Here we present for the first time a detailed and robust comparison of methodologies for fidelity, accuracy and precision. For this collaborative exercise, the lens modeling community was provided simulated cluster images -- of two clusters Are...

  10. Thermoeconomic comparison of industrial heat pumps

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt; Markussen, Christen Malte; Reinholdt, L.


    Four natural working fluids in various heat pump cycles are expected to cover the heating range between 50oC and 150°C. The different thermodynamic cycles are the Condensing Vapour, Transcritical and Compression/Absorption. As the considered technologies have significant differences in application......, limitations and design, a generic comparison is used. To establish the optimal individual temperature range of operation, a thermoeconomic evaluation is performed, with heat price as the decision parameter. Each individual heat pump is favourable in specific temperature intervals, which will vary according...... to the temperature lift between sink and source. At temperature lifts below 30°C the entire temperature range is covered. Exceeding this temperature lift, the range of sink temperatures is not completely covered above 125°C. Three of the heat pumps prove very cost competitive when compared to heating with natural...

  11. Insights from Human/Mouse genome comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Pennacchio, Len A.


    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.

  12. Santa Barbara Cluster Comparison Test with DISPH

    CERN Document Server

    Saitoh, Takayuki


    The Santa Barbara cluster comparison project (Frenk et al. Frenk+1999) 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 qu...

  13. Software Testing Method Based on Model Comparison

    Institute of Scientific and Technical Information of China (English)

    XIE Xiao-dong; LU Yan-sheng; MAO Cheng-yin


    A model comparison based software testing method (MCST) is proposed. In this method, the requirements and programs of software under test are transformed into the ones in the same form, and described by the same model describe language (MDL).Then, the requirements are transformed into a specification model and the programs into an implementation model. Thus, the elements and structures of the two models are compared, and the differences between them are obtained. Based on the diffrences, a test suite is generated. Different MDLs can be chosen for the software under test. The usages of two classical MDLs in MCST, the equivalence classes model and the extended finite state machine (EFSM) model, are described with example applications. The results show that the test suites generated by MCST are more efficient and smaller than some other testing methods, such as the path-coverage testing method, the object state diagram testing method, etc.

  14. Comparison of genomic data via statistical distribution. (United States)

    Amiri, Saeid; Dinov, Ivo D


    Sequence comparison has become an essential tool in bioinformatics, because highly homologous sequences usually imply significant functional or structural similarity. Traditional sequence analysis techniques are based on preprocessing and alignment, which facilitate measuring and quantitative characterization of genetic differences, variability and complexity. However, recent developments of next generation and whole genome sequencing technologies give rise to new challenges that are related to measuring similarity and capturing rearrangements of large segments contained in the genome. This work is devoted to illustrating different methods recently introduced for quantifying sequence distances and variability. Most of the alignment-free methods rely on counting words, which are small contiguous fragments of the genome. Our approach considers the locations of nucleotides in the sequences and relies more on appropriate statistical distributions. The results of this technique for comparing sequences, by extracting information and comparing matching fidelity and location regularization information, are very encouraging, specifically to classify mutation sequences.

  15. Wishbone bus Architecture - A Survey and Comparison

    CERN Document Server

    Sharma, Mohandeep; 10.5121/vlsic.2012.3210


    The performance of an on-chip interconnection architecture used for communication between IP cores depends on the efficiency of its bus architecture. Any bus architecture having advantages of faster bus clock speed, extra data transfer cycle, improved bus width and throughput is highly desirable for a low cost, reduced time-to-market and efficient System-on-Chip (SoC). This paper presents a survey of WISHBONE bus architecture and its comparison with three other on-chip bus architectures viz. Advanced Micro controller Bus Architecture (AMBA) by ARM, CoreConnect by IBM and Avalon by Altera. The WISHBONE Bus Architecture by Silicore Corporation appears to be gaining an upper edge over the other three bus architecture types because of its special performance parameters like the use of flexible arbitration scheme and additional data transfer cycle (Read-Modify-Write cycle). Moreover, its IP Cores are available free for use requiring neither any registration nor any agreement or license.

  16. Ozone Profile Comparisons at High Latitudes (United States)

    McPeters, R. D.; Bojkov, B. R.; Deland, M.


    Ozone profiles measured by both satellite and ground based instruments at a site at 67.4 N were compared. The measurements were made during the Sodankyla Total Column Ozone Intercomparison (SAUNA) which was held in Sodankyla, Finland in March-April 2006 in support of Aura validation. Measurements by the NOAA 16 SBUV/2 and the Aura MLS instrument were compared with lidar and sonde profiles measured in Sodankyla. Profiles from the satellite instruments generally agreed with profiles from the ground-based instruments to within about 10%. The total column ozone comparisons showed that SBUV/2 and the Aura OMI instrument agreed well with the double Brewer instruments provided the scenes were carefully matched.

  17. A Comparison of Methods for Cascade Prediction

    CERN Document Server

    Guo, Ruocheng


    Information cascades exist in a wide variety of platforms on Internet. A very important real-world problem is to identify which information cascades can go viral. A system addressing this problem can be used in a variety of applications including public health, marketing and counter-terrorism. As a cascade can be considered as compound of the social network and the time series. However, in related literature where methods for solving the cascade prediction problem were proposed, the experimental settings were often limited to only a single metric for a specific problem formulation. Moreover, little attention was paid to the run time of those methods. In this paper, we first formulate the cascade prediction problem as both classification and regression. Then we compare three categories of cascade prediction methods: centrality based, feature based and point process based. We carry out the comparison through evaluation of the methods by both accuracy metrics and run time. The results show that feature based met...

  18. Comparison of future energy scenarios for Denmark

    DEFF Research Database (Denmark)

    Kwon, Pil Seok; Østergaard, Poul Alberg


    Scenario-making is becoming an important tool in energy policy making and energy systems analyses. This article probes into the making of scenarios for Denmark by presenting a comparison of three future scenarios which narrate 100% renewable energy system for Denmark in 2050; IDA 2050, Climate...... Commission 2050, and CEESA (Coherent Energy and Environmental System Analysis). Generally, although with minor differences, the scenarios suggest the same technological solutions for the future such as expansion of biomass usage and wind power capacity, integration of transport sector into the other energy...... sectors. The methodologies used in two academic scenarios, IDA 2050 and CEESA, are compared. The main differences in the methodologies of IDA 2050 and CEESA are found in the estimation of future biomass potential, transport demand assessment, and a trial to examine future power grid in an electrical...

  19. PhenoBlocks: Phenotype Comparison Visualizations. (United States)

    Glueck, Michael; Hamilton, Peter; Chevalier, Fanny; Breslav, Simon; Khan, Azam; Wigdor, Daniel; Brudno, Michael


    The differential diagnosis of hereditary disorders is a challenging task for clinicians due to the heterogeneity of phenotypes that can be observed in patients. Existing clinical tools are often text-based and do not emphasize consistency, completeness, or granularity of phenotype reporting. This can impede clinical diagnosis and limit their utility to genetics researchers. Herein, we present PhenoBlocks, a novel visual analytics tool that supports the comparison of phenotypes between patients, or between a patient and the hallmark features of a disorder. An informal evaluation of PhenoBlocks with expert clinicians suggested that the visualization effectively guides the process of differential diagnosis and could reinforce the importance of complete, granular phenotypic reporting.


    Directory of Open Access Journals (Sweden)

    R. Roncella


    Full Text Available Automatic orientation of image sequences in close range photogrammetry is becoming more and more important, not least to maintain a degree of competitiveness with other survey techniques, such as laser scanning. The objective of this paper is to compare two Structure from Motion (SFM strategies. The previous strategy has been used at our Department for some years already in a wide range of projects and is based on the Harris operator and the fundamental matrix plus the trifocal tensor estimation to filter out the outliers. While it has in most cases performed satisfactorily, the percentage of accepted matches is generally smaller than expected; sometimes this leads to failure of the successful estimation of the trifocal tensor. The second one has only recently been implemented and is still under testing; it is based on the SURF operator and the 5-point relative orientation algorithm. The paper will show a comparison between the two strategies on a series of test cases.

  1. Dynamic programming algorithms for biological sequence comparison. (United States)

    Pearson, W R; Miller, W


    Efficient dynamic programming algorithms are available for a broad class of protein and DNA sequence comparison problems. These algorithms require computer time proportional to the product of the lengths of the two sequences being compared [O(N2)] but require memory space proportional only to the sum of these lengths [O(N)]. Although the requirement for O(N2) time limits use of the algorithms to the largest computers when searching protein and DNA sequence databases, many other applications of these algorithms, such as calculation of distances for evolutionary trees and comparison of a new sequence to a library of sequence profiles, are well within the capabilities of desktop computers. In particular, the results of library searches with rapid searching programs, such as FASTA or BLAST, should be confirmed by performing a rigorous optimal alignment. Whereas rapid methods do not overlook significant sequence similarities, FASTA limits the number of gaps that can be inserted into an alignment, so that a rigorous alignment may extend the alignment substantially in some cases. BLAST does not allow gaps in the local regions that it reports; a calculation that allows gaps is very likely to extend the alignment substantially. Although a Monte Carlo evaluation of the statistical significance of a similarity score with a rigorous algorithm is much slower than the heuristic approach used by the RDF2 program, the dynamic programming approach should take less than 1 hr on a 386-based PC or desktop Unix workstation. For descriptive purposes, we have limited our discussion to methods for calculating similarity scores and distances that use gap penalties of the form g = rk. Nevertheless, programs for the more general case (g = q+rk) are readily available. Versions of these programs that run either on Unix workstations, IBM-PC class computers, or the Macintosh can be obtained from either of the authors.

  2. Comparison of Two Recent Launch Abort Platforms (United States)

    Dittemore, Gary D.; Harding, Adam


    The development of new and safer manned space vehicles is a top priority at NASA. Recently two different approaches of how to accomplish this mission of keeping astronauts safe was successfully demonstrated. With work already underway on an Apollo-like launch abort system for the Orion Crew Exploration Vehicle (CEV), an alternative design concept named the Max Launch Abort System, or MLAS, was developed as a parallel effort. The Orion system, managed by the Constellation office, is based on the design of a single solid launch abort motor in a tower positioned above the capsule. The MLAS design takes a different approach placing the solid launch abort motor underneath the capsule. This effort was led by the NASA Engineering and Safety Center (NESC). Both escape systems were designed with the Ares I Rocket as the launch vehicle and had the same primary requirement to safely propel a crew module away from any emergency event either on the launch pad or during accent. Beyond these two parameters, there was little else in common between the two projects, except that they both concluded in successful launches that will further promote the development of crew launch abort systems. A comparison of these projects from the standpoint of technical requirements; program management and flight test objectives will be done to highlight the synergistic lessons learned by two engineers who worked on each program. This comparison will demonstrate how the scope of the project architecture and management involvement in innovation should be tailored to meet the specific needs of the system under development.

  3. IMP 8 magnetosheath field comparisons with models

    Directory of Open Access Journals (Sweden)

    Z. Kaymaz

    Full Text Available This study presents cross-sectional vector maps of the magnetic field derived from IMP 8 magnetometer in the magnetosheath at 30 Re behind the Earth. In addition the vector patterns of the magnetosheath field for northward, southward, and east-west interplanetary magnetic field (IMF directions are qualitatively compared with those obtained from the Spreiter-Stahara gas dynamic (GD and Fedder-Lyon magnetohydrodynamic models (MHD. The main purpose is to display the cross-sectional differences in relation to the dayside merging with different IMF directions, allowing the reader to make direct visual comparisons of the vector patterns. It is seen that for east-west IMF directions, the data-based and MHD-based patterns differ noticeably in a similar way from the GD model, presumably reflecting the influence of dayside magnetic merging of the Earth's magnetic field with the y-component of the interplanetary magnetic field. All three northward IMF cross sections show comparable field draping patterns as expected for a closed magnetosphere. For southward IMF case, on the other hand, differences between the three cross-sectional patterns are greater as seen in the field vector sizes and directions, especially closer to the magnetopause where more disturbed magnetospheric conditions are known to be exist. The data comparisons with the MHD and GD models show that the differences result from the magnetic field-flow coupling and that the effects of dayside reconnection are present in IMP 8 magnetic field measurements.

    Keywords. Vector maps · IMP 8 magnetometer · Inter-planetary magnetic fields

  4. Effects of pitch on auditory number comparisons. (United States)

    Campbell, Jamie I D; Scheepers, Florence


    Three experiments investigated interactions between auditory pitch and the numerical quantities represented by spoken English number words. In Experiment 1, participants heard a pair of sequential auditory numbers in the range zero to ten. They pressed a left-side or right-side key to indicate if the second number was lower or higher in numerical value. The vocal pitches of the two numbers either ascended or descended so that pitch change was congruent or incongruent with number change. The error rate was higher when pitch and number were incongruent relative to congruent trials. The distance effect on RT (i.e., slower responses for numerically near than far number pairs) occurred with pitch ascending but not descending. In Experiment 2, to determine if these effects depended on the left/right spatial mapping of responses, participants responded "yes" if the second number was higher and "no" if it was lower. Again, participants made more number comparison errors when number and pitch were incongruent, but there was no distance × pitch order effect. To pursue the latter, in Experiment 3, participants were tested with response buttons assigned left-smaller and right-larger ("normal" spatial mapping) or the reverse mapping. Participants who received normal mapping first presented a distance effect with pitch ascending but not descending as in Experiment 1, whereas participants who received reverse mapping first presented a distance effect with pitch descending but not ascending. We propose that the number and pitch dimensions of stimuli both activated spatial representations and that strategy shifts from quantity comparison to order processing were induced by spatial incongruities.

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

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


    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 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).

  6. Non primary standards SIM force comparison up to 10 kn

    Directory of Open Access Journals (Sweden)

    Claudia Santo


    Full Text Available This force comparison was performed among IDIC (Chile, LATU (Uruguay and CENAM (Mexico, national laboratories within the Interamerican Metrology System (SIM region. Each laboratory used its national standard for the established measuring range. The comparison started in August 2002 and finished in September 2004. This comparison is the second part of a SIM primary standards comparison carried out with the participation of INMETRO (Brazil, INTI (Argentina and SIC (Colombia, having CENAM as pilot laboratory, (SIM comparison number SIM 7.7. This comparison has an overlap with the force steps used in the CIPM Key Comparison CCM.F-K1.a and CCM.F-K1.b., force points 5 kN and 10 kN.The objective of the comparison was to estimate the level of agreement for the realization of the quantity force and the uncertainty associated to its measurement in the range up to 10 kN. Two transducers (load cells were used as transfer standards, to obtain its maximum accuracy, thecomparison range was selected from 4 kN to 10 kN (starting at 40% of the full load cells range. The results obtained by the participating laboratories were in agreement according to the analysis of comparability performed by the normalized error equation and the Youden plot techniques used.

  7. Vulnerability management tools for COTS software - A comparison

    NARCIS (Netherlands)

    Welberg, S.M.


    In this paper, we compare vulnerability management tools in two stages. In the first stage, we perform a global comparison involving thirty tools available in the market. A framework composed of several criteria based on scope and analysis is used for this comparison. From this global view of the to

  8. Comparison of INMARSAT and ATS3 satellite communication

    Energy Technology Data Exchange (ETDEWEB)


    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.

  9. RDV77 VLBA Hardware/Software Correlator Comparisons (United States)

    Gordon, David


    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.

  10. Competitive Behavior: A Manifestation of Motivation for Ability Comparison (United States)

    Conolley, Edward S.; And Others


    Social comparison theory predicts that when the person is uncertain about the level of his ability, he may seek comparison information through competitive behavior. An experiment is reported in which the level of the subject's uncertainty about his competence was manipulated and subsequent measures of his competitive motivation and behavior were…

  11. [Apples with oranges? Comparison of scientometric indicators between fields]. (United States)

    Schubert, András


    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.

  12. International comparisons of road safety using Singular Value Decomposition.

    NARCIS (Netherlands)

    Oppe, S.


    There is a general interest in the comparison of road safety developments in different countries. Comparisons have been made, based on absolute levels of accident or fatality risk or on the rate of change of functions regarding risk, the number of accidents, fatalities or injuries over time. Such co

  13. 30 CFR 206.155 - Accounting for comparison. (United States)


    ... settlement without resorting to processing determined pursuant to § 206.102 of this subpart; or (2) the value... 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...

  14. Task Characteristics and Target Choice in Social Comparison. (United States)

    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…

  15. Social Comparison Information and Judgments about Depression and Seeking Counseling. (United States)

    Strohmer, Douglas C.; And Others


    Used a role playing technique to examine the influence of social comparison on help seeking attitudes in 80 students. Results indicated that subjects who received serious social comparison information reported the highest depression scores and were more willing to seek counseling help. (JAC)

  16. Finding a Comparison Group: Is Online Crowdsourcing a Viable Option? (United States)

    Azzam, Tarek; Jacobson, Miriam R.


    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's MTurk crowdsourcing service to determine their comparability. Study findings indicate…

  17. Tradeoffs Between Branch Mispredictions and Comparisons for Sorting Algorithms

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel


    Branch mispredictions is an important factor affecting the running time in practice. In this paper we consider tradeoffs between the number of branch mispredictions and the number of comparisons for sorting algorithms in the comparison model. We prove that a sorting algorithm using O(dnlog n...

  18. A CFD code comparison of wind turbine wakes

    DEFF Research Database (Denmark)

    Laan, van der, Paul Maarten; Storey, R. C.; Sørensen, Niels N.;


    A comparison is made between the EllipSys3D and SnS CFD codes. Both codes are used to perform Large-Eddy Simulations (LES) of single wind turbine wakes, using the actuator disk method. The comparison shows that both LES models predict similar velocity deficits and stream-wise Reynolds...

  19. Neuroticism and reactions to social comparison information among cancer patients

    NARCIS (Netherlands)

    Van der Zee, K; Buunk, B; Sanderman, R


    In an experimental study neuroticism was examined as a moderator of breast cancer patients' affective reactions to social comparison information about a fellow patient. Fifty-seven women with breast cancer completed Eysenck's Personality Questionnaire and received social comparison information about

  20. The Age and Sex in the Social Comparison Orientation

    NARCIS (Netherlands)

    Alfonso Urzua, M.; Patricia Zuniga, B.; Buunk, Abraham P.


    The Social Comparison Orientation (SCO) is the personal disposition of individuals prone to social comparison. The aim of this study was to analyze the SCO at different ages in men and women. The main hypothesis is that the average is higher in SCO younger age ranges and decreases as age increases.

  1. Universal seeds for cDNA-to-genome comparison

    Directory of Open Access Journals (Sweden)

    Florea Liliana


    Full Text Available Abstract Background To meet the needs of gene annotation for newly sequenced organisms, optimized spaced seeds can be implemented into cross-species sequence alignment programs to accurately align gene sequences to the genome of a related species. So far, seed performance has been tested for comparisons between closely related species, such as human and mouse, or on simulated data. As the number and variety of genomes increases, it becomes desirable to identify a small set of universal seeds that perform optimally or near-optimally on a large range of comparisons. Results Using statistical regression methods, we investigate the sensitivity of seeds, in particular good seeds, between four cDNA-to-genome comparisons at different evolutionary distances (human-dog, human-mouse, human-chicken and human-zebrafish, and identify classes of comparisons that show similar seed behavior and therefore can employ the same seed. In addition, we find that with high confidence good seeds for more distant comparisons perform well on closer comparisons, within 98–99% of the optimal seeds, and thus represent universal good seeds. Conclusion We show for the first time that optimal and near-optimal seeds for distant species-to-species comparisons are more generally applicable to a wide range of comparisons. This finding will be instrumental in developing practical and user-friendly cDNA-to-genome alignment applications, to aid in the annotation of new model organisms.

  2. Design and Comparison Direct Torque Control Techniques for Induction Motors

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Kazmierkowski, Marian P.; Zelechowski, Marcin


    In this paper a comparison of two significant control methods of induction motor are presented. The first one is a classical Direct Torque and Flux Control (DTC) and is compared with a scheme, which uses Space Vector Modulator (DTC-SVM). A comparison in respect to dynamic and steady state...

  3. Affect and identification in social comparison after loss of work

    NARCIS (Netherlands)

    Ybema, J.F.; Buunk, Abraham (Bram); Heesink, J.A.M.


    This study examined the effects of social comparison among 172 individuals who had recently lost their jobs in a collective dismissal of employees. A part of a fictitious interview with another fired person was presented to the participants. This interview contained social comparison information on

  4. Comparison of Blackbodies for Calibration of Infrared Ear Thermometers

    DEFF Research Database (Denmark)

    Pušnik, Igor; Clausen, Sønnik; Favreau, Jacques-Olivier;


    The article presents the results of the EURAMET Project No. 927 “Comparison of blackbodies for calibration of infrared ear thermometers (IRETs)”. The objective of the comparison was to determine the agreement of blackbodies used for the calibration of IRETs among European national laboratories...

  5. Grouped pair-wise comparison for subjective sound quality evaluation

    Institute of Scientific and Technical Information of China (English)

    MAO Dongxing; GAO Yali; YU Wuzhou; WANG Zuomin


    In subjective sound quality pair-wise comparison evaluation, test time grows with square of the number of sound stimulus. For this reason, subjective evaluation of large quantity of stimulus is difficult to carry out with pair-wise comparison method. A grouped pair-wise comparison (GPC) method is proposed to greatly decrease time and difficult of subjective comparison test, in which stimuli in the whole evaluation corpus are divided into N test groups,with reference-link stimuli configured in each group. Derived from subjective results of each group, final results of all stimuli are reconstructed, and their perceptual attributes of sound quality can be analyzed. With car interior noise as example, realization of subjective sound quality evaluation with GPC method is introduced. The results of GPC evaluation are in good agreement with those obtained from paired comparison and semantic differential methods.

  6. MDA based-approach for UML Models Complete Comparison

    CERN Document Server

    Chaouni, Samia Benabdellah; Mouline, Salma


    If a modeling task is distributed, it will frequently be necessary to integrate models developed by different team members. Problems occur in the models integration step and particularly, in the comparison phase of the integration. This issue had been discussed in several domains and various models. However, previous approaches have not correctly handled the semantic comparison. In the current paper, we provide a MDA-based approach for models comparison which aims at comparing UML models. We develop an hybrid approach which takes into account syntactic, semantic and structural comparison aspects. For this purpose, we use the domain ontology as well as other resources such as dictionaries. We propose a decision support system which permits the user to validate (or not) correspondences extracted in the comparison phase. For implementation, we propose an extension of the generic correspondence metamodel AMW in order to transform UML models to the correspondence model.

  7. Final report of supplementary comparison SIM.M.P-S7: Hydraulic pressure comparison from 7 MPa to 70 MPa (United States)

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


    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 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).

  8. A comparison of cosmological hydrodynamic codes (United States)

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


    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

  9. Wishbone Bus Architecture - A Survey and Comparison

    Directory of Open Access Journals (Sweden)

    Mohandeep Sharma


    Full Text Available The performance of an on-chip interconnection architecture used for communication between IP cores depends on the efficiency of its bus architecture. Any bus architecture having advantages of faster bus clock speed, extra data transfer cycle, improved bus width and throughput is highly desirable for a low cost, reduced time-to-market and efficient System-on-Chip (SoC. This paper presents a survey of WISHBONE bus architecture and its comparison with three other on-chip bus architectures viz. Advanced Microcontroller Bus Architecture (AMBA by ARM, CoreConnect by IBM and Avalon by Altera. The WISHBONE Bus Architecture by Silicore Corporation appears to be gaining an upper edge over the other three bus architecture types because of its special performance parameters like the use of flexible arbitration scheme and additional data transfer cycle (Read-Modify-Write cycle. Moreover, its IP Cores are available free for use requiring neither any registration nor any agreement or license.

  10. Experimental comparison of two quantum computing architectures (United States)

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


    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 ( 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

  11. Aerosol Angstrom Absorption Coefficient Comparisons during MILAGRO. (United States)

    Marley, N. A.; Marchany-Rivera, A.; Kelley, K. L.; Mangu, A.; Gaffney, J. S.


    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 (Mexicano de Petroleo (IMP) and CENICA.

  12. Comparison of Spatiotemporal Fusion Models: A Review

    Directory of Open Access Journals (Sweden)

    Bin Chen


    Full Text Available Simultaneously capturing spatial and temporal dynamics is always a challenge for the remote sensing community. Spatiotemporal fusion has gained wide interest in various applications for its superiority in integrating both fine spatial resolution and frequent temporal coverage. Though many advances have been made in spatiotemporal fusion model development and applications in the past decade, a unified comparison among existing fusion models is still limited. In this research, we classify the models into three categories: transformation-based, reconstruction-based, and learning-based models. The objective of this study is to (i compare four fusion models (STARFM, ESTARFM, ISTAFM, and SPSTFM under a one Landsat-MODIS (L-M pair prediction mode and two L-M pair prediction mode using time-series datasets from the Coleambally irrigation area and Poyang Lake wetland; (ii quantitatively assess prediction accuracy considering spatiotemporal comparability, landscape heterogeneity, and model parameter selection; and (iii discuss the advantages and disadvantages of the three categories of spatiotemporal fusion models.

  13. Comparison of Photogrammetric Techniques for Rockfalls Monitoring (United States)

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


    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.

  14. Asteroseismic versus Gaia distances: a first comparison

    CERN Document Server

    De Ridder, J; Eyer, L; Aerts, C


    Context. The Kepler space mission led to a large amount 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 those 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 TGAS catalog 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 as well as on a logarithmic scale. Results. For a sample of 22 dwarf and subgiant solar-like...

  15. Comparison of Polar Cap (PC) index calculations. (United States)

    Stauning, P.


    The Polar Cap (PC) index introduced by Troshichev and Andrezen (1985) is derived from polar magnetic variations and is mainly a measure of the intensity of the transpolar ionospheric currents. These currents relate to the polar cap antisunward ionospheric plasma convection driven by the dawn-dusk electric field, which in turn is generated by the interaction of the solar wind with the Earth's magnetosphere. Coefficients to calculate PCN and PCS index values from polar magnetic variations recorded at Thule and Vostok, respectively, have been derived by several different procedures in the past. The first published set of coefficients for Thule was derived by Vennerstrøm, 1991 and is still in use for calculations of PCN index values by DTU Space. Errors in the program used to calculate index values were corrected in 1999 and again in 2001. In 2005 DMI adopted a unified procedure proposed by Troshichev for calculations of the PCN index. Thus there exists 4 different series of PCN index values. Similarly, at AARI three different sets of coefficients have been used to calculate PCS indices in the past. The presentation discusses the principal differences between the various PC index procedures and provides comparisons between index values derived from the same magnetic data sets using the different procedures. Examples from published papers are examined to illustrate the differences.

  16. Comparison of particulate verification techniques study (United States)

    Rivera, Rachel


    The efficacy of five particulate verification techniques on four types of materials was studied. Statistical Analysis Software/JMP 6.0 was used to create a statistically valid design of experiments. In doing so, 35 witness coupons consisting of the four types of materials being studied, were intentionally contaminated with particulate fallout. Image Analysis was used to characterize the extent of particulate fallout on the coupons and was used to establish a baseline, or basis of comparison, against the five techniques that were studied. The five particulate verification techniques were the Tapelift, the Particulate Solvent Rinse, the GelPak lift, an in-line vacuum filtration probe, and the Infinity Focusing Microscope (IFM). The four types of materials consisted of magnesium flouride (MgF II) coated mirrors, composite coated silver aluminum (CCAg), Z93 and NS43G coated aluminum, and silicon (si) wafers. The vacuum probe was determined to be most effective for Z93, the tapelift or vacuum probe for MgF2, and the GelPak Lift for CCAg and si substrates. A margin of error for each technique, based on experimental data from two experiments, for si wafer substrates, yielded the following: Tapelift - 67%, Solvent Rinse - 58%, GelPak- 26%, Vacuum Probe - 93%, IFM-to be determined.

  17. Energy storage systems - Characteristics and comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, H. [Wind Energy Research Laboratory (WERL), Universite du Quebec a Rimouski, 300 allee des Ursulines, Que. (Canada); Anti Icing Materials International Laboratory (AMIL), Universite du Quebec a Chicoutimi, 555 boulevard de l' Universite, Que. (Canada); Ilinca, A. [Wind Energy Research Laboratory (WERL), Universite du Quebec a Rimouski, 300 allee des Ursulines, Que. (Canada); Perron, J. [Anti Icing Materials International Laboratory (AMIL), Universite du Quebec a Chicoutimi, 555 boulevard de l' Universite, Que. (Canada)


    Electricity generated from renewable sources, which has shown remarkable growth worldwide, can rarely provide immediate response to demand as these sources do not deliver a regular supply easily adjustable to consumption needs. Thus, the growth of this decentralized production means greater network load stability problems and requires energy storage, generally using lead batteries, as a potential solution. However, lead batteries cannot withstand high cycling rates, nor can they store large amounts of energy in a small volume. That is why other types of storage technologies are being developed and implemented. This has led to the emergence of storage as a crucial element in the management of energy from renewable sources, allowing energy to be released into the grid during peak hours when it is more valuable. The work described in this paper highlights the need to store energy in order to strengthen power networks and maintain load levels. There are various types of storage methods, some of which are already in use, while others are still in development. We have taken a look at the main characteristics of the different electricity storage techniques and their field of application (permanent or portable, long- or short-term storage, maximum power required, etc.). These characteristics will serve to make comparisons in order to determine the most appropriate technique for each type of application. (author)

  18. Species comparison of inflammatory cell reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Boncavage-Hennessey, E.M.; Twerdok, L.E. [Geo-Centers, Inc., Frederick, MD (United States); Finch, R.A.; Gardner, H.S. [Army Biomedical Research and Development Lab., Frederick, MD (United States)


    In comparison to the use of rodent models, the use of fish as a potential model to predict immune dysfunction in response to environmental contaminants is a relatively new concept. The development of a fish model for immunotoxicity is possible due to the phylogenetic conservation of many immune functions. The authors have compared mononuclear cell reactivity following in vitro stimulation among five species; Japanese medaka (Oryzias latipes), rainbow trout (Oncorhynchus mykiss), DBA/2 mice, Sprague-Dawley rats and human ML-1 cells. Mononuclear cells were isolated from the rodent bone marrow and from the teleost anterior kidney (the cell population which most closely resembles mammalian hematopoietic tissue). ML-1 cells are a myeloblastic cell line that were differentiated in vitro to monocytes/macrophages. Cell populations were characterized by myeloperoxidase and nonspecific esterase staining characteristic. Reactive oxidant production following in vitro stimulation by phorbol ester was measured using the following methods: reduction of cytochrome c (detection of extracellular superoxide), reduction of nitroblue tetrazolium (detection of intracellular superoxide) and oxidation of phenol red in the presence of horseradish peroxidase (hydrogen peroxide production). In general, teleost cells demonstrated higher superoxide anion production and mammalian cells produced higher quantities of hydrogen peroxide.

  19. Santa Barbara Cluster Comparison Test with DISPH (United States)

    Saitoh, Takayuki R.; Makino, Junichiro


    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.

  20. A Comparison of Simulation Capabilities for Ducts

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William A [ORNL; Smith, Matt K [ORNL; Gu, Lixing [Florida Solar Energy Center (FSEC); New, Joshua Ryan [ORNL


    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.

  1. Cross comparison of rapid mycoplasma detection platforms. (United States)

    Lawrence, Bill; Bashiri, Houman; Dehghani, Houman


    The use of animal and plant derived raw materials in mammalian cell culture processes may provide a possible route of entry for adventitious contaminants such as mycoplasma. Mycoplasma contaminations of cell culture represent a serious challenge to the production of biotechnology derived therapeutics. The slow growing nature of mycoplasma can disguise their infection of cultures since cells may continue to proliferate, though at reduced levels and with lesser output of engineered protein. Rapid identification of mycoplasma contaminated cell cultures and materials enables a faster response time to prevent the spread of the contamination. We describe here the comparison of different mycoplasma detection methods: two nucleic acid-based technologies, the standard mycoplasma culture procedure, and a hybrid culture-quantitative PCR assay. In this study, a cell line infected with two species of mycoplasma was used to compare the different detection methods. Our data demonstrates that the two nucleic acid-based techniques are robust methods for detection of mycoplasma and have similar detection capability. In contrast, no mycoplasma was detected in the standard culture assay or in a hybrid culture-quantitative PCR assay. This shows a potential limitation of the culture assay that relies on the ability of mycoplasma to grow in broth media.

  2. A numerical comparison of sensitivity analysis techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hamby, D.M.


    Engineering and scientific phenomena are often studied with the aid of mathematical models designed to simulate complex physical processes. In the nuclear industry, modeling the movement and consequence of radioactive pollutants is extremely important for environmental protection and facility control. One of the steps in model development is the determination of the parameters most influential on model results. A {open_quotes}sensitivity analysis{close_quotes} of these parameters is not only critical to model validation but also serves to guide future research. A previous manuscript (Hamby) detailed many of the available methods for conducting sensitivity analyses. The current paper is a comparative assessment of several methods for estimating relative parameter sensitivity. Method practicality is based on calculational ease and usefulness of the results. It is the intent of this report to demonstrate calculational rigor and to compare parameter sensitivity rankings resulting from various sensitivity analysis techniques. An atmospheric tritium dosimetry model (Hamby) is used here as an example, but the techniques described can be applied to many different modeling problems. Other investigators (Rose; Dalrymple and Broyd) present comparisons of sensitivity analyses methodologies, but none as comprehensive as the current work.

  3. Species comparison of protein synthesis accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, G.P.; Popp, R.A.; Francis, M.C.; Bradshaw, B.S.; Bailiff, E.G.


    An important force in evolutionary selection may be informational efficiency, which results in a balance between the energy expended to maintain a high level of fidelity and the energy lost from errors or mutations in the production of defective offspring. The accuracy of DNA replication may be limited by the average accuracy of protein synthesis if the major source of enzymes which make copying errors are those that contain errors resulting from the processes of transcription and translation. Since many gene products are involved in transcription and translation the frequency of mutations which might affect protein fidelity is much higher than those affecting DNA copying. Species comparisons were made of the accuracy of protein synthesis to determine if the requirements for accurate protein synthesis were more stringent for long lived mammals. Using the incorporation of isoleucine in hemoglobin chains which contain no genetically coded isoleucine as a test of protein synthesis fidelity no correlation with lifespan was found among rabbit, marmoset, cow, pig, and human protein synthesis fidelity. The purfication techniques required to prepare highly purified protein for analysis and the criteria for purity are described.

  4. Perceptual expertise in forensic facial image comparison. (United States)

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


    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.

  5. Method and apparatus for biological sequence comparison (United States)

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


    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.

  6. Protein sequence comparison and protein evolution

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, W.R. [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Biochemistry


    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. Comparison between analog and digital filters

    Directory of Open Access Journals (Sweden)

    Zoltan Erdei


    Full Text Available Digital signal processing(DSP is one of the most powerful technologies and will model science and engineering in the 21st century. Revolutionary changes have already been made in different areas of research such as communications, medical imaging, radar and sonar technology, high fidelity audio signal reproducing etc. Each of these fields developed a different signal processing technology with its own algorithms, mathematics and technology, Digital filters are used in two general directions: to separate mixed signals and to restore signals that were compromised in different modes. The objective of this paper is to compare some basic digital filters versus analog filters such as low-pass, high-pass, band-pass filters. Scientists and engineers comprehend that, in comparison with analog filters, digital filters can process the same signal in real-time with broader flexibility. This understanding is considered important to instill incentive for engineers to become interested in the field of DSP. The analysis of the results will be made using dedicated libraries in MATLAB and Simulink software, such as the Signal Processing Toolbox.

  8. TLD environmental monitoring: an interlaboratorial comparison

    Energy Technology Data Exchange (ETDEWEB)

    Taam, Ilka H.; Rosa, Rodolfo O. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], E-mail:, E-mail:; Mauricio, Claudia L.P.; Goncalves, Sergio A.; Seda, Rosangela P.G.; Diz, Ricardo [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], E-mail:, E-mail:, E-mail:, E-mail:


    Since 2000, the Thermoluminescent Dosimetry Laboratory of the Instituto de Engenharia Nuclear (LDOS/IEN) measures the environmental, indoor and outdoor air kerma rate at IEN facilities. It uses Harshaw LiF:Mg,Cu,P thermoluminescent detectors (TLD-100H) chips. In order to evaluate its performance, the LDOS/IEN promoted in 2006 a comparison study with the environmental dosimetry system of the Thermoluminescent Dosimetry Laboratory of the Instituto de Radioprotecao e Dosimetria (LDT/IRD). LDT/IRD has more than 30 years experience with environmental TLD measurements. It also participates, since 1977, in the International Intercomparison of Environmental Dosemeters sponsored by the United States Department of Energy (DOE), with good results. In this study, both LDOS/IEN and LDT/IRD environmental dosimeters were placed together on seven different points of IEN facilities and stay there for two months. At the end of this period, the dosimeters were withdrawn and sent to their respective TLD laboratories to be evaluated following their routine procedures. The results indicated that both laboratories were quite in agreement with a correlation factor of about 0.99. (author)

  9. Comparison of bioseparation methods for microgravity experiments (United States)

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


    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.

  10. Comparison between covariant and orthogonal Lyapunov vectors. (United States)

    Yang, Hong-liu; Radons, Günter


    Two sets of vectors, covariant Lyapunov vectors (CLVs) and orthogonal Lyapunov vectors (OLVs), are currently used to characterize the linear stability of chaotic systems. A comparison is made to show their similarity and difference, especially with respect to the influence on hydrodynamic Lyapunov modes (HLMs). Our numerical simulations show that in both Hamiltonian and dissipative systems HLMs formerly detected via OLVs survive if CLVs are used instead. Moreover, the previous classification of two universality classes works for CLVs as well, i.e., the dispersion relation is linear for Hamiltonian systems and quadratic for dissipative systems, respectively. The significance of HLMs changes in different ways for Hamiltonian and dissipative systems with the replacement of OLVs with CLVs. For general dissipative systems with nonhyperbolic dynamics the long-wavelength structure in Lyapunov vectors corresponding to near-zero Lyapunov exponents is strongly reduced if CLVs are used instead, whereas for highly hyperbolic dissipative systems the significance of HLMs is nearly identical for CLVs and OLVs. In contrast the HLM significance of Hamiltonian systems is always comparable for CLVs and OLVs irrespective of hyperbolicity. We also find that in Hamiltonian systems different symmetry relations between conjugate pairs are observed for CLVs and OLVs. Especially, CLVs in a conjugate pair are statistically indistinguishable in consequence of the microreversibility of Hamiltonian systems. Transformation properties of Lyapunov exponents, CLVs, and hyperbolicity under changes of coordinate are discussed in appendices.

  11. Distributed Wind Policy Comparison Tool Guidebook

    Energy Technology Data Exchange (ETDEWEB)


    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.

  12. A plea for neutral comparison studies in computational sciences.

    Directory of Open Access Journals (Sweden)

    Anne-Laure Boulesteix

    Full Text Available In computational science literature including, e.g., bioinformatics, computational statistics or machine learning, most published articles are devoted to the development of "new methods", while comparison studies are generally appreciated by readers but surprisingly given poor consideration by many journals. This paper stresses the importance of neutral comparison studies for the objective evaluation of existing methods and the establishment of standards by drawing parallels with clinical research. The goal of the paper is twofold. Firstly, we present a survey of recent computational papers on supervised classification published in seven high-ranking computational science journals. The aim is to provide an up-to-date picture of current scientific practice with respect to the comparison of methods in both articles presenting new methods and articles focusing on the comparison study itself. Secondly, based on the results of our survey we critically discuss the necessity, impact and limitations of neutral comparison studies in computational sciences. We define three reasonable criteria a comparison study has to fulfill in order to be considered as neutral, and explicate general considerations on the individual components of a "tidy neutral comparison study". R codes for completely replicating our statistical analyses and figures are available from the companion website

  13. Comparison of high-latitude thermospheric meridionalwinds I: optical and radar experimental comparisons

    Directory of Open Access Journals (Sweden)

    E. M. Griffin


    Full Text Available Thermospheric neutral winds at Kiruna, Sweden (67.4°N, 20.4°E are compared using both direct optical Fabry-Perot Interferometer (FPI measurements and those derived from European incoherent scatter radar (EISCAT measurements. This combination of experimental data sets, both covering well over a solar cycle of data, allows for a unique comparison of the thermospheric meridional component of the neutral wind as observed by different experimental techniques. Uniquely in this study the EISCAT measurements are used to provide winds for comparison using two separate techniques: the most popular method based on the work of Salah and Holt (1974 and the Meridional Wind Model (MWM (Miller et al., 1997 application of servo theory. The balance of forces at this location that produces the observed diurnal pattern are investigated using output from the Coupled Thermosphere and Ionosphere (CTIM numerical model. Along with detailed comparisons from short periods the climatological behaviour of the winds have been investigated for seasonal and solar cycle dependence using the experimental techniques. While there are features which are consistent between the 3 techniques, such as the evidence of the equinoctial asymmetry, there are also significant differences between the techniques both in terms of trends and absolute values. It is clear from this and previous studies that the high-latitude representation of the thermospheric neutral winds from the empirical Horizontal Wind Model (HWM, though improved from earlier versions, lacks accuracy in many conditions. The relative merits of each technique are discussed and while none of the techniques provides the perfect data set to address model performance at high-latitude, one or more needs to be included in future HWM reformulations.

    Key words. Meteorology and atmospheric dynamics (thermospheric dynamics, Ionosphere (ionosphere-atmosphere interactions, auroral ionosphere

  14. Final report on supplementary comparison EURAMET.L-S20: Comparison of laser distance measuring instruments (United States)

    Wisniewski, Mariusz; Ramotowski, Zbigniew; Pollinger, Florian; Wedde, Martin; Matus, Michael; Banhidi-Bergendorf, Zita; Stalder, Oliver; Thalmann, Rudolf; Lassila, Antti; Unkuri, Jarkko; Balling, Petr; Hynek, Jaromír; Astrua, Milena; Pisani, Marco; Prieto, Emilio; Karlsson, Helge; Hansrud Kjær, Peter; Flys, Olena; Lillepea, Lauri; Odrats, Indrek; Fíra, Roman; Fodrekova, Anna; Harnosova, Eva; Duta, Alexandru; Teoderescu, Dragos


    The results of the supplementary comparison EURAMET.L-S20 of laser distance measuring instruments (EDMs) are reported. It was the first comparison of EDMs. Four EDMs were circulated among 13 European NMIs. Each EDM was calibrated at a distance of 0.3 m and at regularly spaced intervals every 5 m for a range up to 50 m. The measurements were conducted between 2011 and 2012. The test of the stability of the EDMs showed significant changes in the mean results over timescales of months or even days. The uncertainty of the results mainly comes from the uncertainty due to the reproducibility, and it is difficult to distinguish the part relevant to the laboratories' calibration and measurement capabilities. For the analysis both the deviations from the reference value and the En numbers were calculated. For the evaluation of the reference value, the weighted mean approach has been chosen, although the consistency check failed in many cases. A more complicated procedure for the evaluation of the reference value was proposed, which slightly changes the uncertainty of the reference value. Most results agreed within the claimed uncertainties. Some 4.7% of the results showed some larger deviations. Some participants may have a high percentage of values that are not compliant with their CMC claims due to the influence of the artifact and the estimation of its uncertainty. 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 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).

  15. Lindley-Shannon Information for Comparison of Priors Under Paired Comparisons Model

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam


    Full Text Available One of the main differences between classical statistics and Bayesian statistics is that the latter can utilise prior information in a formal way. This information can be quantified in terms of a probability distribution which is known as the prior distribution. If there is no relevant prior information available then there are ways to derive a 'non-informative' prior distribution. In this study, the informative and non-informative prior distributions for the parameters of the Bradley-Terry model for paired comparison data are compared.

  16. Comparison of Standard and Fast Charging Methods for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Petr Chlebis


    Full Text Available This paper describes a comparison of standard and fast charging methods used in the field of electric vehicles and also comparison of their efficiency in terms of electrical energy consumption. The comparison was performed on three-phase buck converter, which was designed for EV’s fast charging station. The results were obtained by both mathematical and simulation methods. The laboratory model of entire physical application, which will be further used for simulation results verification, is being built in these days.

  17. Stability comparison of two absolute gravimeters: optical versus atomic interferometers

    CERN Document Server

    Gillot, Pierre; Landragin, Arnaud; Santos, Franck Pereira Dos; Merlet, Sébastien


    We report the direct comparison between the stabilities of two mobile absolute gravimeters of different technology: the LNE-SYRTE Cold Atom Gravimeter and FG5X\\#216 of the Universit\\'e du Luxembourg. These instruments rely on two different principles of operation: atomic and optical interferometry. The comparison took place in the Walferdange Underground Laboratory for Geodynamics in Luxembourg, at the beginning of the last International Comparison of Absolute Gravimeters, ICAG-2013. We analyse a 2h10 duration common measurement, and find that the CAG shows better immunity with respect to changes in the level of vibration noise, as well as a slightly better short term stability.

  18. Dynamical Coupling of Intrinsically Disordered Proteins and Their Hydration Water: Comparison with Folded Soluble and Membrane Proteins (United States)

    Gallat, F.-X.; Laganowsky, A.; Wood, K.; Gabel, F.; van Eijck, L.; Wuttke, J.; Moulin, M.; Härtlein, M.; Eisenberg, D.; Colletier, J.-P.; Zaccai, G.; Weik, M.


    Hydration water is vital for various macromolecular biological activities, such as specific ligand recognition, enzyme activity, response to receptor binding, and energy transduction. Without hydration water, proteins would not fold correctly and would lack the conformational flexibility that animates their three-dimensional structures. Motions in globular, soluble proteins are thought to be governed to a certain extent by hydration-water dynamics, yet it is not known whether this relationship holds true for other protein classes in general and whether, in turn, the structural nature of a protein also influences water motions. Here, we provide insight into the coupling between hydration-water dynamics and atomic motions in intrinsically disordered proteins (IDP), a largely unexplored class of proteins that, in contrast to folded proteins, lack a well-defined three-dimensional structure. We investigated the human IDP tau, which is involved in the pathogenic processes accompanying Alzheimer disease. Combining neutron scattering and protein perdeuteration, we found similar atomic mean-square displacements over a large temperature range for the tau protein and its hydration water, indicating intimate coupling between them. This is in contrast to the behavior of folded proteins of similar molecular weight, such as the globular, soluble maltose-binding protein and the membrane protein bacteriorhodopsin, which display moderate to weak coupling, respectively. The extracted mean square displacements also reveal a greater motional flexibility of IDP compared with globular, folded proteins and more restricted water motions on the IDP surface. The results provide evidence that protein and hydration-water motions mutually affect and shape each other, and that there is a gradient of coupling across different protein classes that may play a functional role in macromolecular activity in a cellular context. PMID:22828339

  19. Comparison of several methods for BAP measurement. (United States)

    Nakajima, J; Murata, Y; Sakamoto, M


    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.

  20. A comparison of current prediction imaging programs (United States)

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


    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

  1. Comparison between Major Confined and Eruptive Flares (United States)

    Gopalswamy, N.; Yashiro, S.; Mäkelä, P.; Dennis, B. R.


    Statistical studies have shown that a large fraction of major solar flares (42% M-class and 15% X-class) are not associated with coronal mass ejections (CMEs). The CME-less flares are confined flares as opposed to the eruptive flares associated with CMEs. Confined flares are certainly good particle accelerators as inferred from intense microwave, hard X-ray, and gamma-ray emissions. Note that a single acceleration mechanism operates in confined flares, whereas eruptive flares can have both flare-resident and shock accelerations (the shock acceleration is due to energetic CMEs). In this paper, we report on a statistical study of more than two dozen confined flares with soft X-ray flare size exceeding M5 in comparison with a control sample of eruptive flares with similar soft X-ray flare size. We compare the microwave and X-ray emission characteristics in the two populations; these emissions correspond to sunward energy flow. For a given X-ray flare size, the microwave flux is scattered over a wider range for the eruptive flares when compared to the confined flares. We also compare the metric and longer wavelength radio bursts between the two populations; these emissions correspond to the flow of nonthermal electrons away from the Sun. We find that almost all the confined flares lack metric radio bursts, suggesting that there is very little flow of energy into the interplanetary medium. On the other hand, there is high degree of association between eruptive flares and metric radio bursts. This suggests that in confined flares the accelerated electrons have no access to open magnetic field lines. Finally, we examined the association of EUV waves with the two flare populations. While we find EUV waves in most of the eruptive flares, there was no confined flare with EUV waves. This suggests that CMEs is a necessary condition for the generation of global waves.

  2. Comparisons of Photospheric Convection Cell Characteristics (United States)

    Pesnell, W. D.; Wiliams, P. E.


    Solar convection plays an important role in generating and structuring the solar magnetic field as well as a mechanism responsible for the 11-year solar cycle. The observed phenomena are strongly linked within both observational and physical regimes. Our main focus is the study of supergranulation from SOHO/MDI Dopplergrams. Suites of analysis methods are applied to time-series of Doppler images to quantitatively describe supergranule flow velocities, spatial scales and temporal lifetimes. SOHO/MDI magnetograms also show cellular structures, which trace the clustering of magnetic field lines around supergranule boundaries. These boundaries are extrapolated into the chromosphere where they are observed as a cellular network. We present preliminary results of applying methods similar to those applied to the Dopplergrams for estimating the spatial and temporal characteristics of this network. We extend our study to above the photosphere to the chromosphere where another cellular network is seen. Once again the responsibility lies with supergranulation. Spatial analysis on CaIIK data from the Precision Solar Photometric Telescope (PSPT) provides typical size scales for the network that can be compared to both the magnetogram network and supergranulation itself. Data comparisons over time can be made, notably between Doppler data received during the current (2008) and previous (1996) solar minima. Our provisional findings show that horizontal and radial velocity flows within supergranules are stronger during the current minimum, while the supergranules themselves appear larger during the previous minimum. However, comparable results are found for the 1/e lifetimes derived from each data set. We extend these provisional results by performing statistical analyses both within and between the various data sets.


    Directory of Open Access Journals (Sweden)



    Full Text Available This empirical study aims at finding out how similar and/or different are the future Romanian and Slovenian managers in assessing the importance of organizations social responsibility values. The assumption of the research is that most of most of students in engineering and business will hold middle management position in the near future. The sample consists of 727 undergraduate and graduate students levels from Romania and Slovenia, two former socialist countries. The data has been collected between 2008 and 2009 in the framework of GLOBE student project , using a section of GLOBE III questionnaire, about the importance of CSR related values in critical decisions. The findings concern the similarities and significant differences between: 1 whole Romanian and Slovenian samples; 2 Romanian and Slovenian students in engineering; 3 Romanian and Slovenian students in business. Our findings revealed a trend toward convergence in the importance given to decisions effect on contribution to the economic welfare of the nation and local community, as well as on employees professional growth and development and on environment. The biggest difference between the groups concerns the decisions effect on firm profitability (the Romanians considering this value as more important in critical decisions than the Slovenians. The students in engineering proved to be a more homogeneous group, showing convergence in assessing the importance of eight out of fifteen social responsibility values. The biggest difference concerns the decisions effect on firm profitability (Romanians consider it as having higher importance in critical decisions than the Slovenians. Comparison of students in business revealed convergence in assessing the importance of employees professional growth and development and decisions effect on environment. The biggest positive difference concerns the same value of decisions effect on firm profitability. The Romanians are well behind Slovenians in

  4. Comparison of Methods of Height Anomaly Computation (United States)

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


    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.

  5. Comparison of Electrophysiological Auditory Measures in Fishes. (United States)

    Maruska, Karen P; Sisneros, Joseph A


    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.

  6. Report of the key comparison APMP.QM-K19. APMP comparison on pH measurement of borate buffer (United States)

    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


    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 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. Methodological issues in international comparison of interval breast cancers

    NARCIS (Netherlands)

    Bulliard, Jean-Luc; Sasieni, Peter; Klabunde, Carrie; De Landtsheer, Jean-Pierre; Yankaskas, Bonnie C.; Fracheboud, Jacques


    International comparisons of interval cancers (IC) are important to better understand the relationship between programmes' performance and screening practices. In this respect, differences in (i) definition, (ii) identification and (iii) quantification of IC have received little attention. To examin

  8. A Simple Illustration for the Need of Multiple Comparison Procedures (United States)

    Carter, Rickey E.


    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.

  9. CCM key comparison CCM.D-K4 'Hydrometer' (United States)

    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.


    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

  10. Comparison theorems for neutral stochastic functional differential equations (United States)

    Bai, Xiaoming; Jiang, Jifa


    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.

  11. Operating Reserves and Wind Power Integration: An International Comparison; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    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.


    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.

  12. Characterization and comparison of emissions from rudimentary waste disposal technologies (United States)

    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.

  13. HIRENASD Comparisons of FEM modal frequencies and modeshapes (United States)

    National Aeronautics and Space Administration — Below are frequency comparisons of different models with experiment Note Modeshapes aren't very descriptive for higher modes. There is coupling between them so this...

  14. Radioxenon standards used in laboratory inter-comparisons. (United States)

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


    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.

  15. The Comparison between the Statistical Heuristic Search and A

    Institute of Scientific and Technical Information of China (English)

    张Po; 张铃


    In order to further unravel the principle and performance of the statistical heuristic seach algorithm S A,in this paper,in comparison with A * search,the hypothesis,performance and computational complexity of SA are discussed.

  16. A new phase comparison pilot protection based on wavelet transform

    Institute of Scientific and Technical Information of China (English)

    YANG Ying; TAI Neng-ling; YU Wei-yong


    Current phase comparison based pilot protection had been generally utilized as primary protection of the transmission lines in China from the 1950's to the 1980's. Conventional phase comparison pilot protection has a long phase comparison time, which results in a longer fault-clearing time. This paper proposes a new current phase comparison. pilot protection scheme that is based on non-power frequency fault current component.The phase of the fourth harmonic current of each end of the protected line has been abstracted by utilizing complex wavelet transformation and then compared in order to determine whether the inner fault occurs or not. This way can greatly decrease fault-clearing time and improve performances of this pilot protection when fault occurs under the heavy-load current and asymmetrical operation conditions. Many EMTP simulations have verified theproposed scheme's correctness and effectiveness.

  17. A Comparison of Cross-Sector Cyber Security Standards

    Energy Technology Data Exchange (ETDEWEB)

    Robert P. Evans


    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.

  18. Cylinder expansion test and gas gun experiment comparison

    Energy Technology Data Exchange (ETDEWEB)

    Harrier, Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    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.

  19. Tip studies using CFD and comparison with tip loss models

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver; Johansen, J.


    The flow past a rotating LM8.2 blade equipped with two different tips are computed using CFD. The different tip flows are analysed and a comparison with two different tip loss models is made. Keywords: tip flow, aerodynamics, CFD......The flow past a rotating LM8.2 blade equipped with two different tips are computed using CFD. The different tip flows are analysed and a comparison with two different tip loss models is made. Keywords: tip flow, aerodynamics, CFD...

  20. A Comparison of Techniques for Optimal Infrastructure Restoration (United States)


    models several infrastructure systems as one big system. The “coupled approach” models each infrastructure system with one individual model and uses...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS A COMPARISON OF TECHNIQUES FOR OPTIMAL INFRASTRUCTURE RESTORATION by Carsten Schulze December...01-2014 to 12-19-2014 4. TITLE AND SUBTITLE A COMPARISON OF TECHNIQUES FOR OPTIMAL INFRASTRUCTURE RESTORATION 5. FUNDING NUMBERS 6. AUTHOR(S) Carsten

  1. Comparisons organized by Ionizing Radiation Metrology Laboratory of FTMC, Lithuania. (United States)

    Gudelis, A; Gorina, I


    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).

  2. Massive thin accretion discs: Pt. 3; Comparison with the observations

    Energy Technology Data Exchange (ETDEWEB)

    Laor, A. (Tel Aviv Univ. (Israel). Wise Observatory)


    This paper presents a detailed comparison of theoretical thin accretion disc models with the spectra of 101 bright AGN. The models have been described previously; they take into account all relativistic effects and use an improved approximation for the local spectrum. The comparison is made by fitting the observation with a two-component model, a thin 'bare' accretion disc and an underlying power law. (author).

  3. Comparison of some Phoenix and gusev soil types

    DEFF Research Database (Denmark)

    Walter..[], Goetz; Hviid, S.F.; Madsen, Morten Bo


    The comparison of soil particles at the Phoenix landing site and in Gusev Crater provides clues on their origin and global distribution. Some unusual Phoenix particles are possibly of (more) local origin, as they appear to be absent in Gusev dunes.......The comparison of soil particles at the Phoenix landing site and in Gusev Crater provides clues on their origin and global distribution. Some unusual Phoenix particles are possibly of (more) local origin, as they appear to be absent in Gusev dunes....

  4. Reward Comparison: The Achilles’ heel and hope for addiction


    Grigson, Patricia Sue


    In the words of the late Charles Flaherty, reward comparison is commonplace. Rats and man, it appears, compare all rewards and this capacity likely contributes to our ability to select the most appropriate reward/behavior (food, water, salt, sex), at the most ideal level (e.g., a certain sweetness), at any given time. A second advantage of our predisposition for reward comparison is that the availability of rich alternative rewards can protect against our becoming addicted to any single rewar...

  5. Comparison groups on bills: Automated, personalized energy information

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Maithili; Kempton, Willett; Payne, Christopher


    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.

  6. Changes in latent fingerprint examiners' markup between analysis and comparison. (United States)

    Ulery, Bradford T; Hicklin, R Austin; Roberts, Maria Antonia; Buscaglia, JoAnn


    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%).

  7. Collective violence: comparisons between youths and chimpanzees. (United States)

    Wrangham, Richard W; Wilson, Michael L


    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


    Directory of Open Access Journals (Sweden)

    Somashekhara Reddy


    Full Text Available The purpose of this study is to correlate the findings of Magnetic Resonance Imaging with Arthroscopy in internal derangements of knee and to assess the sensitivity, specificity and accuracy of Magnetic Resonance Imaging in comparison to Arthroscopy. METHODS AND MATERIALS Fifty six patients with history of suspected internal derangement of knee were evaluated prospectively with MRI and correlated with arthroscopy during a one and half a year period from March 2012 to September 2013.1.5 Tesla MRI machine using a closed extremity coil is used. Sequences used in MRI of the knee include Turbo-spin echo (TSE, FFE (Gradient echo and Short Tau Inversion Recovery (STIR sequences in Axial, Sagittal and Coronal planes using a slice thickness of 3 mm with a 0.3 mm slice gap. Arthroscopy of the knee with standard anteromedial and anterolateral portals with the patient in supine position done in all the cases. RESULTS The diagnostic sensitivity, specificity and accuracy of MRI in detecting cruciate ligament and meniscal injuries as compared to Arthroscopy are as follows: Anterior Cruciate Ligament (ACL: 97.29%, 89.47%, 94.64%; Posterior Cruciate Ligament (PCL: 100%, 100%, 100%; Medial Meniscus (MM: 100%, 93.33%, 98.21% and Lateral Meniscus (LM: 93.10, 92.59, 92.85. Most common lesions found were ACL and Medial Meniscal tears (posterior horn of MM being the most common site. SUMMARY AND CONCLUSION  MRI is a useful non-invasive modality having high sensitivity, specificity and accuracy in diagnosing cruciate ligament and meniscal injuries.  MRI should be considered as the first line of investigation in all patients with suspected internal derangements of knee.  MRI being easily available and non-invasive is useful as a pre-operative screening modality, thus improves the quality of diagnostic and therapeutic arthroscopies and further reduces the morbidity.  Arthroscopy is the standard diagnosing tool in all patients with suspected internal

  9. Bilateral comparison of cryogenic radiometers between NPL and UME, linked to the CCPR-S3 supplementary comparison (United States)

    Goodman, T.


    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 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).

  10. SUPPLEMENTARY COMPARISON Final report on EUROMET.L-S19 (EUROMET Project 910): Comparison of squareness measurements (United States)

    Mokros, Jiri


    A bilateral comparison has been undertaken between two European national metrology institutes (NMIs) in the subject field of squareness measurement. Specifically, both NMIs made measurements of a cylindrical squareness standard, made of steel. Both participants made measurements of the internal angles at several positions around the circumference, as well as measurement of the corresponding straightness profiles. The report lists the results obtained by both participants, as well as an analysis of the results and their uncertainties. The results are in good agreement with one another. This bilateral comparison followed the same technical protocol as a previous supplementary comparison (EUROMET.L-S10). 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 The final report has been peer-reviewed and approved for publication by EURAMET, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  11. KEY COMPARISON Final report on APMP international comparison APMP.EM-K9: High voltage AC-DC transfer standards (United States)

    Wei, Yih-Cheng; Yeh, Hsin-Da


    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 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).

  12. Active charge/passive discharge solar heating systems: Thermal analysis and performance comparisons and performance comparisons (United States)

    Swisher, J.


    This type of system combines liquid-cooled solar collector panels with a massive integral storage component that passively heats the building interior by radiation and free convection. The TRNSYS simulation program is used to evaluate system performance and to provide input for the development of a simplified analysis method. This method, which provides monthly calculations of delivered solar energy, is based on Klein's Phi-bar procedure and data from hourly TRNSYS simulations. The method can be applied to systems using a floor slab, a structural wall, or a water tank as the storage component. Important design parameters include collector area and orientation, building heat loss, collector and heat exchanger efficiencies, storage capacity, and storage to room coupling. Performance simulation results are used for comparisons with active and passive solar designs.

  13. New York State 2009 NHTS Comparison Report

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, Frank [ORNL; Reuscher, Tim [Macrosys; Hwang, Ho-Ling [ORNL


    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

  14. Development, comparison, and evaluation of software for radial distortion elimination (United States)

    Papadaki, A. I.; Georgopoulos, A.


    Lately the interest of Computer Vision and Photogrammetry community has been focused on the automation of the processes of identification and elimination of the radial distortion, with the aim to correct the image coordinates and finally to obtain digital images with reliable geometric information. This effort has reached the point of development of commercial or free image processing software, claiming that it can automatically identify and remove the radial distortion from an image. In this paper in depth research has been conducted about the radial distortion and the methods of its identification and elimination. Specifically, it has been attempted to evaluate software as the aforementioned, about its effectiveness, accuracy and applicability on the elimination of the radial distortion from images. For the attainment of the desired aim, four different methods of comparison and evaluation of the performance of the software, with respect to the correction of an image, have been employed. The applied methods are (i) the optical evaluation of the produced digital images, (ii) the subtraction of the images, (iii) the comparison of the curves of the remaining radial distortion in the images and (iv) the comparison of the results from the orientation of an image pair. However, it was really important to have a benchmark for the evaluation, in order to ensure the objectivity and accuracy of the comparison. Therefore, a new reliable algorithm has been developed, which was of known and controllable accuracy. The results of these comparisons are presented and evaluated for their reliability and usefulness.

  15. Development of Fraction Comparison Strategies: A Latent Transition Analysis. (United States)

    Rinne, Luke F; Ye, Ai; Jordan, Nancy C


    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

  16. International Pyroheliometer Comparison 2010 Results from SORCE/TIM (United States)

    Heuerman, K.; Kopp, G.; Harber, D.


    The Eleventh International Pyrheliometer Comparison (IPC-XI), organized by the World Radiation Center (WRC) on behalf of the World Meteorological Organization (WMO), was held 27 September - 15 October 2010 at the Physikalisch-Meteorologisches Observatorium Davos (PMOD/WRC) in Davos Dorf, Switzerland with nearly 100 participants representing approximately 60 countries. This ground-based comparison, held every 5 years, has established a multi-decadal baseline record of solar measurement inter-comparisons with which solar radiometers can be linked to the WRC-maintained World Radiation Reference (WRR) and compared to other current and historical radiometers across the IPC’s multi-decadal time range. A ground-based SOlar Radiation and Climate Experiment (SORCE) Total Irradiance Monitor (TIM) participated in the IPC this year, indirectly linking the on-orbit total solar irradiance (TSI) measurements that NASA’s SORCE mission has been acquiring since 2003 with the IPC record. We report the results of this 3-week inter-comparison and estimate the corrections needed and uncertainties introduced in linking these ground-based relative comparisons to the spaceborne TSI data record.

  17. Nonionic homopolymeric amphipols: application to membrane protein folding, cell-free synthesis, and solution nuclear magnetic resonance. (United States)

    Bazzacco, Paola; Billon-Denis, Emmanuelle; Sharma, K Shivaji; Catoire, Laurent J; Mary, Sophie; Le Bon, Christel; Point, Elodie; Banères, Jean-Louis; Durand, Grégory; Zito, Francesca; Pucci, Bernard; Popot, Jean-Luc


    Nonionic amphipols (NAPols) synthesized by homotelomerization of an amphiphatic monomer are able to keep membrane proteins (MPs) stable and functional in the absence of detergent. Some of their biochemical and biophysical properties and applications have been examined, with particular attention being paid to their complementarity with the classical polyacrylate-based amphipol A8-35. Bacteriorhodopsin (BR) from Halobacterium salinarum and the cytochrome b(6)f complex from Chlamydomonas reinhardtii were found to be in their native state and highly stable following complexation with NAPols. NAPol-trapped BR was shown to undergo its complete photocycle. Because of the pH insensitivity of NAPols, solution nuclear magnetic resonance (NMR) two-dimensional (1)H-(15)N heteronuclear single-quantum coherence spectra of NAPol-trapped outer MP X from Escherichia coli (OmpX) could be recorded at pH 6.8. They present a resolution similar to that of the spectra of OmpX/A8-35 complexes recorded at pH 8.0 and give access to signals from solvent-exposed rapidy exchanging amide protons. Like A8-35, NAPols can be used to fold MPs to their native state as demonstrated here with BR and with the ghrelin G protein-coupled receptor GHS-R1a, thus extending the range of accessible folding conditions. Following NAPol-assisted folding, GHS-R1a bound four of its specific ligands, recruited arrestin-2, and activated binding of GTPγS by the G(αq) protein. Finally, cell-free synthesis of MPs, which is inhibited by A8-35 and sulfonated amphipols, was found to be very efficient in the presence of NAPols. These results open broad new perspectives on the use of amphipols for MP studies.

  18. Follow-up effects of social comparison information on the quality of life of cancer patients : The moderating role of social comparison orientation

    NARCIS (Netherlands)

    Buunk, Abraham P.; Bennenbroek, Femke T. C.; Stiegelis, Heidi E.; van den Bergh, Alfons C. M.; Sanderman, Robbert; Hagedoorn, Mariet


    Objective: To examine how social comparison orientation (SCO) moderates the effects of three types of social comparison information on the global quality of life of cancer patients 2 weeks and 3 months later. Design: Cancer patients (n=226) were provided with social comparison information just prior

  19. Conducting Indirect-Treatment-Comparison and Network-Meta-Analysis Studies : Report of the ISPOR Task Force on Indirect Treatment Comparisons Good Research Practices: Part 2

    NARCIS (Netherlands)

    Hoaglin, David C.; Hawkins, Neil; Jansen, Jeroen P.; Scott, David A.; Itzler, Robbin; Cappelleri, Joseph C.; Boersma, Cornelis; Thompson, David; Larholt, Kay M.; Diaz, Mireya; Barrett, Annabel


    Evidence-based health care decision making requires comparison of all relevant competing interventions. In the absence of randomized controlled trials involving a direct comparison of all treatments of interest, indirect treatment comparisons and network meta-analysis provide useful evidence for jud

  20. Follow-up effects of social comparison information on the quality of life of cancer patients: The moderating role of social comparison orientation

    NARCIS (Netherlands)

    Buunk, A.P.; Bennenbroek, F.T.C.; Stiegelis, H.E.; Bergh, A.C.M. van den; Sanderman, R.; Hagedoorn, M.


    Objective: To examine how social comparison orientation (SCO) moderates the effects of three types of social comparison information on the global quality of life of cancer patients 2 weeks and 3 months later. Design: Cancer patients (n = 226) were provided with social comparison information just pri

  1. Artificial bias typically neglected in comparisons of uncertain atmospheric data (United States)

    Pitkänen, Mikko R. A.; Mikkonen, Santtu; Lehtinen, Kari E. J.; Lipponen, Antti; Arola, Antti


    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.

  2. Two-photon assisted clock comparison to picosecond precision

    CERN Document Server

    Zhang, Shi-Wei; Yao, Yin-Ping; Wan, Ren-Gang; Zhang, Tong-Yi


    We have experimentally demonstrated a clock comparison scheme utilizing time-correlated photon pairs generated from the spontaneous parametric down conversion process of a laser pumped beta-barium borate crystal. The coincidence of two-photon events are analyzed by the cross correlation of the two time stamp sequences. Combining the coarse and fine part of the time differences at different resolutions, a 64 ps precision for clock synchronization has been realized. We also investigate the effects of hardware devices used in the system on the precision of clock comparison. The results indicate that the detector's time jitter and the background noise will degrade the system performance. With this method, comparison and synchronization of two remote clocks could be implemented with a precision at the level of a few tens of picoseconds.

  3. cocor: a comprehensive solution for the statistical comparison of correlations.

    Directory of Open Access Journals (Sweden)

    Birk Diedenhofen

    Full Text Available A valid comparison of the magnitude of two correlations requires researchers to directly contrast the correlations using an appropriate statistical test. In many popular statistics packages, however, tests for the significance of the difference between correlations are missing. To close this gap, we introduce cocor, a free software package for the R programming language. The cocor package covers a broad range of tests including the comparisons of independent and dependent correlations with either overlapping or nonoverlapping variables. The package also includes an implementation of Zou's confidence interval for all of these comparisons. The platform independent cocor package enhances the R statistical computing environment and is available for scripting. Two different graphical user interfaces-a plugin for RKWard and a web interface-make cocor a convenient and user-friendly tool.

  4. The NIH Toolbox Pattern Comparison Processing Speed Test: Normative Data (United States)

    Carlozzi, Noelle E.; Beaumont, Jennifer L.; Tulsky, David S.; Gershon, Richard C.


    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

  5. Price Comparisons on the Internet Based on Computational Intelligence (United States)

    Kim, Jun Woo; Ha, Sung Ho


    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

  6. A socio-economic comparison of green and conventional products

    DEFF Research Database (Denmark)

    Leinikka Dall, Ole; Wenzel, Henrik; Grüttner, Henrik


    This paper presents an environmental and socio-economic comparison of functionally equivalent product pairs: a product (or service) complying with eco-labeling criteria towards a conventional product (or service) within the same product/service group. The comparison comprises product pairs within...... the categories of TV-sets, washing machines, textile services, bookshelves and copy paper. The study included development of a methodology for the environmental and socio-economic comparison as well as the application of the methodology on the selected product groups. The study was funded and published...... by the Danish Environmental Protection Agency 2009-2011 [1]. The definition of product pairs took offset in criteria for environmental labeling schemes as The EU Ecolabel and The Nordic Swan – label. The “green product” meets as a minimum requirement the standards for ecolabeling. The similar “conventional...

  7. Comparison of immunoturbidimetric and immunonephelometric assays for specific proteins. (United States)

    Mali, Bahera; Armbruster, David; Serediak, Ernie; Ottenbreit, Tammy


    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.

  8. BEACON: automated tool for Bacterial GEnome Annotation ComparisON

    KAUST Repository

    Kalkatawi, Manal Matoq Saeed


    Background Genome annotation is one way of summarizing the existing knowledge about genomic characteristics of an organism. There has been an increased interest during the last several decades in computer-based structural and functional genome annotation. Many methods for this purpose have been developed for eukaryotes and prokaryotes. Our study focuses on comparison of functional annotations of prokaryotic genomes. To the best of our knowledge there is no fully automated system for detailed comparison of functional genome annotations generated by different annotation methods (AMs). Results The presence of many AMs and development of new ones introduce needs to: a/ compare different annotations for a single genome, and b/ generate annotation by combining individual ones. To address these issues we developed an Automated Tool for Bacterial GEnome Annotation ComparisON (BEACON) that benefits both AM developers and annotation analysers. BEACON provides detailed comparison of gene function annotations of prokaryotic genomes obtained by different AMs and generates extended annotations through combination of individual ones. For the illustration of BEACON’s utility, we provide a comparison analysis of multiple different annotations generated for four genomes and show on these examples that the extended annotation can increase the number of genes annotated by putative functions up to 27 %, while the number of genes without any function assignment is reduced. Conclusions We developed BEACON, a fast tool for an automated and a systematic comparison of different annotations of single genomes. The extended annotation assigns putative functions to many genes with unknown functions. BEACON is available under GNU General Public License version 3.0 and is accessible at:

  9. Comparison between Agent Development Frameworks : BEE-GENT and JADE

    Directory of Open Access Journals (Sweden)

    Ankit Singh


    Full Text Available Agent-oriented programming is the software paradigm that brings the concepts of artificial intelligence into the realm of distributed systems. Agent-based distributed systems have been used in wide range of applications. This encouraged us to research on different agent development tools. This paper presents a brief introduction of multi-agent development frameworks: BEE-GENT and JADE. Comparison between their architecture, interaction mechanism and implementation are discussed. Based on the comparison, the advantages and limitations of BEE-GENT and JADE are concluded in the end.

  10. Comparison of greedy algorithms for α-decision tree construction

    KAUST Repository

    Alkhalid, Abdulaziz


    A comparison among different heuristics that are used by greedy algorithms which constructs approximate decision trees (α-decision trees) is presented. The comparison is conducted using decision tables based on 24 data sets from UCI Machine Learning Repository [2]. Complexity of decision trees is estimated relative to several cost functions: depth, average depth, number of nodes, number of nonterminal nodes, and number of terminal nodes. Costs of trees built by greedy algorithms are compared with minimum costs calculated by an algorithm based on dynamic programming. The results of experiments assign to each cost function a set of potentially good heuristics that minimize it. © 2011 Springer-Verlag.

  11. An Adaptive Algorithm for Pairwise Comparison-based Preference Measurement

    DEFF Research Database (Denmark)

    Meissner, Martin; Decker, Reinhold; Scholz, Sören W.


    The Pairwise Comparison‐based Preference Measurement (PCPM) approach has been proposed for products featuring a large number of attributes. In the PCPM framework, a static two‐cyclic design is used to reduce the number of pairwise comparisons. However, adaptive questioning routines that maximize...... the information gained from pairwise comparisons promise to further increase the efficiency of this approach. This paper introduces a new adaptive algorithm for PCPM, which accounts for several response errors. The suggested approach is compared with an adaptive algorithm that was proposed for the Analytic...

  12. National Pyranometers comparison of solar thermal labs in Mexico (United States)

    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.


    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.

  13. Mining Knowledge from Result Comparison Between Spatial Clustering Themes

    Institute of Scientific and Technical Information of China (English)

    SHA Zongyao; BIAN Fuling


    This paper introduces some definitions and defines a set of calculating indexes to facilitate the research, and then presents an algorithm to complete the spatial clustering result comparison between different clustering themes. The research shows that some valuable spatial correlation patterns can be further found from the clustering result comparison with multi-themes, based on traditional spatial clustering as the first step. Those patterns can tell us what relations those themes have, and thus will help us have a deeper understanding of the studied spatial entities. An example is also given to demonstrate the principle and process of the method.

  14. Designing experiments and analyzing data a model comparison perspective

    CERN Document Server

    Maxwell, Scott E


    Through this book's unique model comparison approach, students and researchers are introduced to a set of fundamental principles for analyzing data. After seeing how these principles can be applied in simple designs, students are shown how these same principles also apply in more complicated designs. Drs. Maxwell and Delaney believe that the model comparison approach better prepares students to understand the logic behind a general strategy of data analysis appropriate for various designs; and builds a stronger foundation, which allows for the introduction of more complex topics omitt

  15. Efficient and Secure Comparison for On-Line Auctions

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Krøigaard, Mikkel; Geisler, Martin Joakim


    We propose a protocol for secure comparison of integers based on homomorphic encryption. We also propose a homomorphic encryption scheme that can be used in our protocol and makes it more efficient than previous solutions. Our protocol is well-suited for application in on-line auctions, both...... with respect to functionality and performance. It minimizes the amount of information bidders need to send, and for comparison of 16 bit numbers with security based on 1024 bit RSA (executed by two parties), our implementation takes 0.28 seconds including all computation and communication. Using precomputation...

  16. Differential clock comparisons with phase-locked local oscillators

    CERN Document Server

    Hume, David B


    We develop 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 scaling of measurement precision. We present a model for such frequency comparisons and develop numerical simulations of the protocol with realistic noise sources. This provides a route to reduce frequency ratio measurement durations by more than an order of magnitude as clock inaccuracies reach 1x10^-18.

  17. Measuring perinatal health equity and migration indicators for international comparisons. (United States)

    Gagnon, Anita J; Small, Rhonda; Sarasua, Irene; Lang, Carly


    An international research collaboration answered, "Can equity in perinatal health for migrant women be measured for comparison across countries?" In nine countries, perinatal databases were assessed for the availability of equity indicators. Equity data were also sought from women and health records. Optimal sources of data differed depending on the migrant perinatal health equity indicator. Health and migration data, required to capture equity, were often not reported in the same location. Migration indicators other than country of birth were underreported. Perinatal health equity can be measured for international comparisons, although a standardized protocol is required to capture all indicators.

  18. Probing beyond the laser coherence time in optical clock comparisons (United States)

    Hume, David B.; Leibrandt, David R.


    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.

  19. BLAST Ring Image Generator (BRIG: simple prokaryote genome comparisons

    Directory of Open Access Journals (Sweden)

    Beatson Scott A


    Full Text Available Abstract Background Visualisation of genome comparisons is invaluable for helping to determine genotypic differences between closely related prokaryotes. New visualisation and abstraction methods are required in order to improve the validation, interpretation and communication of genome sequence information; especially with the increasing amount of data arising from next-generation sequencing projects. Visualising a prokaryote genome as a circular image has become a powerful means of displaying informative comparisons of one genome to a number of others. Several programs, imaging libraries and internet resources already exist for this purpose, however, most are either limited in the number of comparisons they can show, are unable to adequately utilise draft genome sequence data, or require a knowledge of command-line scripting for implementation. Currently, there is no freely available desktop application that enables users to rapidly visualise comparisons between hundreds of draft or complete genomes in a single image. Results BLAST Ring Image Generator (BRIG can generate images that show multiple prokaryote genome comparisons, without an arbitrary limit on the number of genomes compared. The output image shows similarity between a central reference sequence and other sequences as a set of concentric rings, where BLAST matches are coloured on a sliding scale indicating a defined percentage identity. Images can also include draft genome assembly information to show read coverage, assembly breakpoints and collapsed repeats. In addition, BRIG supports the mapping of unassembled sequencing reads against one or more central reference sequences. Many types of custom data and annotations can be shown using BRIG, making it a versatile approach for visualising a range of genomic comparison data. BRIG is readily accessible to any user, as it assumes no specialist computational knowledge and will perform all required file parsing and BLAST comparisons

  20. Bistatic Reverberation in Shallow Water: Modelling and Data Comparison

    Institute of Scientific and Technical Information of China (English)

    李风华; 刘建军


    Bistatic and monostatic reverberation data were recorded in the 2001 Asian Sea International Acoustic Experiment (ASIAEX). A model based on the normal mode theory has been developed to calculate bistatic bottom reverberation in shallow water and to explain the recorded data. The comparisons between the monostatic and bistatic reverberation data are discussed, and the comparisons between model predictions and measured bistatic reverberation data are also presented. The numerical and experimental results show that the numericalpredictions from the bistatic reverberation model fit the experimental data well, and the long-range bistatic reverberation with a time delay can be approximately expressed by the monostatic reverberation data.

  1. Integration of light and temperature in the regulation of circadian gene expression in Drosophila.

    Directory of Open Access Journals (Sweden)

    Catharine E Boothroyd


    Full Text Available Circadian clocks are aligned to the environment via synchronizing signals, or Zeitgebers, such as daily light and temperature cycles, food availability, and social behavior. In this study, we found that genome-wide expression profiles from temperature-entrained flies show a dramatic difference in the presence or absence of a thermocycle. Whereas transcript levels appear to be modified broadly by changes in temperature, there is a specific set of temperature-entrained circadian mRNA profiles that continue to oscillate in constant conditions. There are marked differences in the biological functions represented by temperature-driven or circadian regulation. The set of temperature-entrained circadian transcripts overlaps significantly with a previously defined set of transcripts oscillating in response to a photocycle. In follow-up studies, all thermocycle-entrained circadian transcript rhythms also responded to light/dark entrainment, whereas some photocycle-entrained rhythms did not respond to temperature entrainment. Transcripts encoding the clock components Period, Timeless, Clock, Vrille, PAR-domain protein 1, and Cryptochrome were all confirmed to be rhythmic after entrainment to a daily thermocycle, although the presence of a thermocycle resulted in an unexpected phase difference between period and timeless expression rhythms at the transcript but not the protein level. Generally, transcripts that exhibit circadian rhythms both in response to thermocycles and photocycles maintained the same mutual phase relationships after entrainment by temperature or light. Comparison of the collective temperature- and light-entrained circadian phases of these transcripts indicates that natural environmental light and temperature cycles cooperatively entrain the circadian clock. This interpretation is further supported by comparative analysis of the circadian phases observed for temperature-entrained and light-entrained circadian locomotor behavior. Taken

  2. [Development of an Excel spreadsheet for meta-analysis of indirect and mixed treatment comparisons]. (United States)

    Tobías, Aurelio; Catalá-López, Ferrán; Roqué, Marta


    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.

  3. Paired comparison product testing when individual preferences are stochastic

    NARCIS (Netherlands)

    B. Wierenga (Berend)


    textabstractThe preference of an individual in a paired comparison product test is stochastic, i.e. the probability p, that he will prefer one of the two alternatives, is not 0 or 1, but lies somewhere between these values. It is shown that the distribution of p, when approximated by a beta distribu

  4. Efficient Multicriteria Protein Structure Comparison on Modern Processor Architectures. (United States)

    Sharma, Anuj; Manolakos, Elias S


    Fast increasing computational demand for all-to-all protein structures comparison (PSC) is a result of three confounding factors: rapidly expanding structural proteomics databases, high computational complexity of pairwise protein comparison algorithms, and the trend in the domain towards using multiple criteria for protein structures comparison (MCPSC) and combining results. We have developed a software framework that exploits many-core and multicore CPUs to implement efficient parallel MCPSC in modern processors based on three popular PSC methods, namely, TMalign, CE, and USM. We evaluate and compare the performance and efficiency of the two parallel MCPSC implementations using Intel's experimental many-core Single-Chip Cloud Computer (SCC) as well as Intel's Core i7 multicore processor. We show that the 48-core SCC is more efficient than the latest generation Core i7, achieving a speedup factor of 42 (efficiency of 0.9), making many-core processors an exciting emerging technology for large-scale structural proteomics. We compare and contrast the performance of the two processors on several datasets and also show that MCPSC outperforms its component methods in grouping related domains, achieving a high F-measure of 0.91 on the benchmark CK34 dataset. The software implementation for protein structure comparison using the three methods and combined MCPSC, along with the developed underlying rckskel algorithmic skeletons library, is available via GitHub.

  5. Efficient Multicriteria Protein Structure Comparison on Modern Processor Architectures

    Directory of Open Access Journals (Sweden)

    Anuj Sharma


    F-measure of 0.91 on the benchmark CK34 dataset. The software implementation for protein structure comparison using the three methods and combined MCPSC, along with the developed underlying rckskel algorithmic skeletons library, is available via GitHub.

  6. Tip Studies using CFD and Comparison with Tip Loss Models

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver


    of the averaged axial induction factor and the normal and tangential loads are compared with those of a standard blade element momentum code using 2D calibrated airfoil data for a wind speed of 9 m s(-1), where the agreement in computed power is good. Further, a comparison with a new tip loss model proposed...

  7. Multidimensional first-order dominance comparisons of population wellbeing

    DEFF Research Database (Denmark)

    Arndt, Thomas Channing; Siersbæk, Nikolaj; Østerdal, Lars Peter Raahave

    In this paper, we convey the concept of first-order dominance (FOD) with particular focus on applications to multidimensional population welfare comparisons. We give an account of the fundamental equivalent definitions of FOD, illustrated with simple numerical examples. An implementable method fo...

  8. Comparison Principles in Nonlinear Mechanics and Their Application

    Institute of Scientific and Technical Information of China (English)

    王照林; 楚天广


    A kind of infinite demensional nonlinear dynamical system described by functional differential equations with finite time delay is investigated in this paper The comparison principles of LRC type are established and applied to the problems of averaging principle and practical stability in terms of two measures for the system with time delay

  9. Commercialising Comparison: Pearson Puts the TLC in Soft Capitalism (United States)

    Hogan, Anna; Sellar, Sam; Lingard, Bob


    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…

  10. Challenges in Using Comparison Data in Child Welfare Evaluations (United States)

    White, Catherine Roller; O'Brien, Kirk; Davis, Cynthia W.; Rogg, Carla; Rudlang-Perman, Kristen; Morgan, Linda Jewell; Houston, Millicent


    Objective: This article describes the evaluation of permanency roundtables, an intervention to help youth in foster care achieve legal permanency and the challenges evaluators faced in finding and using appropriate comparison data. Method: In 2009, permanency roundtables were conducted for 496 children in Georgia, most of whom had spent extended…

  11. Secure comparison protocols in the semi-honest model

    NARCIS (Netherlands)

    Veugen, P.J.M.; Blom, F.; Hoogh, S.J.A. de; Erkin, Z.


    Due to high complexity, comparison protocols with secret inputs have been a bottleneck in the design of privacy-preserving cryptographic protocols. Different solutions based on homomorphic encryption, garbled circuits and secret sharing techniques have been proposed over the last few years, each cla

  12. A Comparison of Deaf and Hearing Children's Reading Comprehension Profiles (United States)

    Kyle, Fiona E.; Cain, Kate


    Purpose: Although deaf children typically exhibit severe delays in reading achievement, there is a paucity of research looking at their text-level comprehension skills. We present a comparison of deaf and normally hearing readers' profiles on a commonly used reading comprehension assessment: the Neale Analysis of Reading Ability II. Methods:…

  13. Conceptual Change through Changing the Process of Comparison (United States)

    Wasmann-Frahm, Astrid


    Classification can serve as a tool for conceptualising ideas about vertebrates. Training enhances classification skills as well as sharpening concepts. The method described in this paper is based on the "hybrid-model" of comparison that proposes two independently working processes: associative and theory-based. The two interact during a…

  14. Rethinking educational comparison under the conditions of globalisation

    DEFF Research Database (Denmark)

    Moutsios, Stavros

    The paper re-considers theoretically educational comparison through a discussion and critique of existing approaches. It starts from the premises that education is a trans-historical institution, since all societies transmit knowledge to their new generations, but also specific to each society...

  15. A flow level capacity comparison of UMTS and HSDPA

    NARCIS (Netherlands)

    Litjens, R.


    Using an operator perspective, we present a flow level capacity comparison of an HSDPA and a typically deployed release ‘99-based UMTS network, both in a qualitative and quantitative sense. The purpose of the qualitative reasoning is to generate a solid intuitive understanding of the HSDPA benefits.

  16. Comparison studies of ozone precursors in Phoenix, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, C.; Guyton, J.; Lee, C.P. [Arizona Dept. of Environmental Quality, Phoenix, AZ (United States); Parmar, S. [Atmospheric Analysis and Consulting Co., Ventura, CA (United States)


    This paper will present the comparison of the ozone precursors monitoring program for Phoenix, Arizona during 1992 and 1993. Specific details and methodologies will be presented involving collection of air samples and analysis of speciated measurements for reactive VOC and carbonyl precursors responsible for ozone formation. Quality control and quality assurance techniques will also be discussed.

  17. Comparison of large networks with sub-sampling strategies (United States)

    Ali, Waqar; Wegner, Anatol E.; Gaunt, Robert E.; Deane, Charlotte M.; Reinert, Gesine


    Networks are routinely used to represent large data sets, making the comparison of networks a tantalizing research question in many areas. Techniques for such analysis vary from simply comparing network summary statistics to sophisticated but computationally expensive alignment-based approaches. Most existing methods either do not generalize well to different types of networks or do not provide a quantitative similarity score between networks. In contrast, alignment-free topology based network similarity scores empower us to analyse large sets of networks containing different types and sizes of data. Netdis is such a score that defines network similarity through the counts of small sub-graphs in the local neighbourhood of all nodes. Here, we introduce a sub-sampling procedure based on neighbourhoods which links naturally with the framework of network comparisons through local neighbourhood comparisons. Our theoretical arguments justify basing the Netdis statistic on a sample of similar-sized neighbourhoods. Our tests on empirical and synthetic datasets indicate that often only 10% of the neighbourhoods of a network suffice for optimal performance, leading to a drastic reduction in computational requirements. The sampling procedure is applicable even when only a small sample of the network is known, and thus provides a novel tool for network comparison of very large and potentially incomplete datasets.


    NARCIS (Netherlands)



    401 men and 475 women completed the Dutch version of the Eysenck Personality Questionnaire. Factor comparisons all exceeded 0.97 so that the factors of Psychoticism, Extraversion, Neuroticism, and Social Desirability are deemed to be identical in the two countries, England and The Netherlands. Sex d

  19. Cross-cultural comparisons of personality : the Netherlands and England

    NARCIS (Netherlands)



    401 men and 475 women completed the Dutch version of the Eysenck Personality Questionnaire. Factor comparisons all exceeded 0.97 so that the factors of Psychoticism, Extraversion, Neuroticism, and Social Desirability are deemed to be identical in the two countries, England and The Netherlands. Sex d

  20. Continuous improvement comparison between Danish and Mexican companies

    DEFF Research Database (Denmark)

    Christiansen, Thomas Bøhm


    comprise such concepts as TQM, Kaizen, Six Sigma and Lean Manufacturing. The paper shows the results of the analysis and a comparison of how and to what degree such tools are used in different places, which allow us to address similarities and dissimilarities of the application. The results are discussed...

  1. InteraqCT Comparison on Assemblies - Technical Protocol

    DEFF Research Database (Denmark)

    Stolfi, Alessandro; De Chiffre, Leonardo


    The InteraqCT comparison on assemblies is as an activity within the Marie Curie ESR Project INTERAQCT - International Network for the Training of Early stage Researchers on Advanced Quality control by Computed Tomography funded by the European Commission's 7th Framework Programme FP7-PEOPLE - Under...

  2. InteraqCT Comparison on Assemblies - Reference Measurements

    DEFF Research Database (Denmark)

    Stolfi, Alessandro; De Chiffre, Leonardo


    The InteraqCT comparison on assemblies is as an activity within the Marie Curie ESR Project INTERAQCT - International Network for the Training of Early stage Researchers on Advanced Quality control by Computed Tomography funded by the European Commission's 7th Framework Programme FP7-PEOPLE - Under...


    Directory of Open Access Journals (Sweden)

    Mandeep Kaur Gulati


    Full Text Available Mobile Ad-hoc Network (MANET is an infrastructure less and decentralized network which need a robust dynamic routing protocol. Many routing protocols for such networks have been proposed so far to find optimized routes from source to the destination and prominent among them are Dynamic Source Routing (DSR, Ad-hoc On Demand Distance Vector (AODV, and Destination-Sequenced Distance Vector (DSDV routing protocols. The performance comparison of these protocols should be considered as the primary step towards the invention of a new routing protocol. This paper presents a performance comparison of proactive and reactive routing protocols DSDV, AODV and DSR based on QoS metrics (packet delivery ratio, average end-to-end delay, throughput, jitter, normalized routing overhead and normalized MAC overhead by using the NS-2 simulator. The performance comparison is conducted by varying mobility speed, number of nodes and data rate. The comparison results show that AODV performs optimally well not the best among all the studied protocols.


    Institute of Scientific and Technical Information of China (English)

    SHI Wei-hui; WANG Yue-peng; SHEN Chun


    The stability about Navier-Stokes equation and Euler equation was brought into comparison. And by taking their typical initial value problem for example, the reason of leading to the difference in stability between Navier-Stokes equation and Euler equation was also analyzed.

  5. Emotional Analysis of Music: A Comparison of Methods

    NARCIS (Netherlands)

    Soleymani, Mohammad; Aljanaki, Anna; Yang, Yi-Hsuan; Caro, Michael N.; Eyben, Florian; Markov, Konstantin; Schuller, Bjorn; Veltkamp, Remco; Weninger, Felix; Wiering, Frans


    Music as a form of art is intentionally composed to be emotionally expressive. The emotional features of music are invaluable for music indexing and recommendation. In this paper we present a cross-comparison of automatic emotional analysis of music. We created a public dataset of Creative Commons l

  6. Modeling Expressed Emotions in Music using Pairwise Comparisons

    DEFF Research Database (Denmark)

    Madsen, Jens; Nielsen, Jens Brehm; Jensen, Bjørn Sand


    We introduce a two-alternative forced-choice experimental paradigm to quantify expressed emotions in music using the two wellknown arousal and valence (AV) dimensions. In order to produce AV scores from the pairwise comparisons and to visualize the locations of excerpts in the AV space, we...

  7. A comparison of coincident GRACE and ICESat data over Antarctica

    NARCIS (Netherlands)

    Gunter, B.; Urban, T.; Riva, R.E.M.; Helsen, M.M.; Harpold, R.; Poole, S.; Nagel, P.; Schutz, B.; Tapley, B.


    In this study, we present a comparison of coincident GRACE and ICESat data over Antarctica. The analysis focused on the secular changes over a 4-year period spanning from 2003 to 2007, using the recently reprocessed and publicly available data sets for both missions. The results show that the two in

  8. The Second Workshop on Lineshape Code Comparison: Isolated Lines

    Directory of Open Access Journals (Sweden)

    Spiros Alexiou


    Full Text Available In this work, we briefly summarize the theoretical aspects of isolated line broadening. We present and discuss test run comparisons from different participating lineshape codes for the 2s-2p transition for LiI, B III and NV.

  9. Student Perceptions and Social Comparisons and Performance Expectancy. (United States)

    Holahan, Carole K.; And Others

    Student self-expectations are believed to exert a powerful influence on performance. Student perceptions and social comparisons during transfer students' (N=1362) first semester in a large state university were examined to determine variables that might be related to the formation of student performance expectations. Subjects completed…

  10. Term Based Comparison Metrics for Controlled and Uncontrolled Indexing Languages (United States)

    Good, B. M.; Tennis, J. T.


    Introduction: We define a collection of metrics for describing and comparing sets of terms in controlled and uncontrolled indexing languages and then show how these metrics can be used to characterize a set of languages spanning folksonomies, ontologies and thesauri. Method: Metrics for term set characterization and comparison were identified and…

  11. Experimental Precision and Variety Comparison Precision in Regional Crop Trials

    Institute of Scientific and Technical Information of China (English)

    KONG Fan-ling; ZHANG Qun-yuan; GE Zhi-nan; YANG Fu-xin; ZHANG De-gui; LIU Wen-xin


    According to the basic concepts of precision and the principles of analysis of variance (ANOVA), precision types for experiments and variety comparison in regional crop trials (RCT) were studied and developed; expected variety comparison precision (EVCP) and realized variety comparison precision (RVCP) and the corresponding statistical indexes of them were proposed. It was explained that experimental precision (EP) and variety comparison precision (VCP) are two kinds of precision of RCT; EP includes error precision and variety mean precision, which can be measured respectively by the coefficient of variation of single observation's error (CVe) and the coefficient of variation of variety mean's error (CVY); VCP includes EVCP and RVCP, which can be measured respectively by the detectable least relative difference (DLRD) and the relative least significant distance (RLSD); EP is an important factor of VCP but not identical to it; RVCP is the realization of EVCP. Besides error, experimental design and GE interaction and ANOVA model affect VCP. Several application examples for these precision indexes were presented, and the precision of regional cotton trials in the Yellow River Valley and the Changjiang Valley were investigated through the historical data of RCTs from 1980 to 1999.

  12. On the extraction of weights from pairwise comparison matrices

    NARCIS (Netherlands)

    Dijkstra, Theo K.


    We study properties of weight extraction methods for pairwise comparison matrices that minimize suitable measures of inconsistency, 'average error gravity' measures, including one that leads to the geometric row means. The measures share essential global properties with the AHP inconsistency measure

  13. A Comparison of Chinese and American Indian (Chumash Medicine

    Directory of Open Access Journals (Sweden)

    James D. Adams


    Full Text Available Chinese and Chumash traditional medical approaches are similar in terms of disease causation, use of acupuncture or healing touch, plants, spiritual and philosophical approaches. This article provides a brief comparison and discussion of Chinese and Chumash traditional medical practices. A table of 66 plants is presented along with Chinese and Chumash uses of each plant. These uses are compared and contrasted.

  14. Sexual harassment in northwest Europe - A cross-cultural comparison

    NARCIS (Netherlands)

    Timmerman, M.C.; Bajema, C.W.


    A substantial body of research addressing the issue of sexual harassment in the workplace has been developed over the past decade. In this article we consider the complexity of cross-cultural comparisons of the incidence rates of sexual harassment and present the results of our research on sexual ha

  15. Informal Supports of Older Adults: A Rural-Urban Comparison. (United States)

    Scott, Jean Pearson; Roberto, Karen A.


    Compared rural and urban older adults on exchanges of assistance and social activities with children and friends. Found that illness prompted more giving and receiving of assistance for rural in comparison to urban informal supports. Rural widows were more actively involved in exchanges of assistance with friend networks than were urban widows.…

  16. Federal Personnel: Federal/Private Sector Pay Comparisons (United States)


    Federal Employees Covered by Social Security, December 1984. ^This finding is based on a comparison of employer cost associated with the various...and gender. Specifically, ’For a further discussion, see Robert Willis, "Wage Determinante : A Survey and ReinterpreteÜori of Human Capital Earnings

  17. Type II Shocks Characteristics: Comparison with associated CMEs and Flares

    CERN Document Server

    Pothitakis, G; Preka-Papadema, P; Moussas, X; Caroubalos, C; Alissandrakis, C E; Hillaris, A; Tsitsipis, P; Kontogeorgos, A; Bougeret, J -L; Dumas, G; 10.1063/1.2347985


    A number of metric (100-650 MHz) typeII bursts was recorded by the ARTEMIS-IV radiospectrograph in the 1998-2000 period; the sample includes both CME driven shocks and shocks originating from flare blasts. We study their characteristics in comparison with characteristics of associated CMEs and flares.

  18. Arima model and exponential smoothing method: A comparison (United States)

    Wan Ahmad, Wan Kamarul Ariffin; Ahmad, Sabri


    This study shows the comparison between Autoregressive Moving Average (ARIMA) model and Exponential Smoothing Method in making a prediction. The comparison is focused on the ability of both methods in making the forecasts with the different number of data sources and the different length of forecasting period. For this purpose, the data from The Price of Crude Palm Oil (RM/tonne), Exchange Rates of Ringgit Malaysia (RM) in comparison to Great Britain Pound (GBP) and also The Price of SMR 20 Rubber Type (cents/kg) with three different time series are used in the comparison process. Then, forecasting accuracy of each model is measured by examinethe prediction error that producedby using Mean Squared Error (MSE), Mean Absolute Percentage Error (MAPE), and Mean Absolute deviation (MAD). The study shows that the ARIMA model can produce a better prediction for the long-term forecasting with limited data sources, butcannot produce a better prediction for time series with a narrow range of one point to another as in the time series for Exchange Rates. On the contrary, Exponential Smoothing Method can produce a better forecasting for Exchange Rates that has a narrow range of one point to another for its time series, while itcannot produce a better prediction for a longer forecasting period.

  19. An Inter-industry comparison of market orientation in Ghana

    DEFF Research Database (Denmark)

    Kuada, John


    The study makes two contributions to the existing knowledge on market orientation. First it extends the insight obtained from previous research on the antecedents of market orientation into the developing country context. Second, it undertakes an inter-industry comparison with the view to determine...... whether the implicit assumption of weak (or non) inter-industry differences in market orientation is tenable...

  20. On the Reliability of Unit Value Ratios in International Comparisons

    NARCIS (Netherlands)

    Timmer, Marcel P.


    In this paper reliability indicators are developed for the Laspeyres and Paasche index type currency conversion factors used in the industry of origin approach to international comparisons of output. Given the fact that these conversion factors are calculated on basis of a sampling technique, sampli

  1. The Comparison of Some Physical and Physiological Parameters of Footballers (United States)

    Ekinci, Ezgi Samar; Beyleroglu, Malik; Ulukan, Hasan; Konuklar, Ercan; Gürkan, Alper Cenk; Erbay, Adem


    In this study, it's to aim for comparison of some physical and physiological parameters of footballers at "The Erenler Sport Team" and "Didim Municipality Sport Team". Thirty volunteers sportsman from each two teams joined to this research. It measured the values of age, weight, length, flexibility, balance, power of left-right…

  2. Comparison of aerosol size distribution in coastal and oceanic environments

    NARCIS (Netherlands)

    Kusmierczyk-Michulec, J.T.; Eijk, A.M.J. van


    The results of applying the empirical orthogonal functions (EOF) method to decomposition and approximation of aerosol size distributions are presented. A comparison was made for two aerosol data sets, representing coastal and oceanic environments. The first data set includes measurements collected a

  3. Effects of Perceptual Variations on Number Comparison Tasks. (United States)

    Kingma, Johannes; Loth, Franciska L.


    Investigates the performance of 502 children ranging in age from four years to six years, ten months, on two-choice and multiple-choice number comparison tasks, and explores the effects of perceptual manipulations of elements in the multiple-choice tasks. (RH)

  4. More 'mapping' in brain mapping: statistical comparison of effects

    DEFF Research Database (Denmark)

    Jernigan, Terry Lynne; Gamst, Anthony C.; Fennema-Notestine, Christine


    , or for that matter of brain structure, are generally constructed using analyses that yield no basis for inferences regarding the spatial nonuniformity of the effects. In the normal analysis path for functional images, for example, there is nowhere a statistical comparison of the observed effect in any voxel relative...

  5. Mathematics Comparison Study = Etude Comporative Portant Sur les Mathematiques. (United States)

    Alberta Dept. of Education, Edmonton. Curriculum Standards Branch.

    At the request of the Council of Ministries of Education, Canada (CMEC), Alberta Learning conducted this Mathematics Comparison Study. The focus of this study is from Kindergarten to Grade 12. All provinces and territories were invited to participate, and only the Quebec region declined. Participating regions were invited to send a representative…

  6. A Comparison of Acculturation Measures among Hispanic/Latino Adolescents (United States)

    Unger, Jennifer B.; Ritt-Olson, Anamara; Wagner, Karla; Soto, Daniel; Baezconde-Garbanati, Lourdes


    Acculturation has been associated with numerous health and social outcomes among Hispanic/Latino adolescents. Various self-report scales have been used to measure acculturation, making comparisons of results across studies difficult. This study administered several commonly-used acculturation scales to 221 Hispanic/Latino 9th grade students in Los…

  7. Comparison of NWP prognosis and local monitoring data from NPPs

    DEFF Research Database (Denmark)

    Astrup, Poul; Mikkelsen, Torben


    For four German nuclear power plant sites and for Risø, the site of the Danish nuclear research reactors now being decommissioned, Numerical Weather Predictions (NWP) of wind speed and direction have been compared to 10 minute averaged local measurements. For the German sites the comparison covers...

  8. Framework for Detailed Comparison of Building Environmental Assessment Tools

    Directory of Open Access Journals (Sweden)

    Ola Eriksson


    Full Text Available Understanding how Building Environmental Assessments Tools (BEATs measure and define “environmental” building is of great interest to many stakeholders, but it is difficult to understand how BEATs relate to each other, as well as to make detailed and systematic tool comparisons. A framework for comparing BEATs is presented in the following which facilitates an understanding and comparison of similarities and differences in terms of structure, content, aggregation, and scope. The framework was tested by comparing three distinctly different assessment tools; LEED-NC v3, Code for Sustainable Homes (CSH, and EcoEffect. Illustrations of the hierarchical structure of the tools gave a clear overview of their structural differences. When using the framework, the analysis showed that all three tools treat issues related to the main assessment categories: Energy and Pollution, Indoor Environment, and Materials and Waste. However, the environmental issues addressed, and the parameters defining the object of study, differ and, subsequently, so do rating, results, categories, issues, input data, aggregation methodology, and weighting. This means that BEATs measure “environmental” building differently and push “environmental” design in different directions. Therefore, tool comparisons are important, and the framework can be used to make these comparisons in a more detailed and systematic way.

  9. Cross-cultural comparison of medicinal floras used against snakebites

    DEFF Research Database (Denmark)

    Molander, Marianne; Saslis-Lagoudakis, C Haris; Jäger, Anna K;


    highlighted families respectively). At the genus level, only Piper (Piperaceae) was recovered as a 'hot' genus in at least two floras. Seven genera were highlighted by both analyses (25-44% of the highlighted genera). CONCLUSIONS: Cross-cultural comparison of medicinal floras used against snakebites appears...


    Institute of Scientific and Technical Information of China (English)


    This paper is devoted to deriving a comparison theorem of solutions to backward doubly stochastic differential equations driven by Brownian motion and backward It-Kunita integral. By the application of this theorem, we give an existence result of the solutions to these equations with continuous coefficients.

  11. Teacher Job Satisfaction and Burnout Viewed through Social Comparisons (United States)

    Kitchel, Tracy; Smith, Amy R.; Henry, Anna L.; Robinson, J. Shane; Lawver, Rebecca G.; Park, Travis D.; Schell, Ashley


    Understanding job satisfaction, stress, and burnout within agricultural education has the potential to impact the profession's future. Studying these factors through the theoretical lens of social comparison takes a cultural approach by investigating how agriculture teachers interact with and compare themselves to others. The purpose of this study…

  12. NREL Pyrheliometer Comparisons: 22 September - 3 October 2008

    Energy Technology Data Exchange (ETDEWEB)

    Stoffel, T.; Reda, I.


    NREL Pyrheliometer Comparisons (NPCs) are held annually at the Solar Radiation Research Laboratory (SRRL) in Golden, Colorado. Open to all pyrheliometer owner/operators, the NPC provides an opportunity to determine the unique WRR transfer factor for each participating pyrheliometer. This paper reports on the results of NPC-2008, which was scheduled from September 22 to October 3, 2008.

  13. Identifying and Comparing Scandinavian Ethnography: Comparisons and Influences (United States)

    Beach, Dennis


    In recent years, there has been a significant growth in the volume of research production in education ethnography in Scandinavia due partly to a regionally financed network. The present article makes some comparisons between Scandinavian and other education research contexts in relation to aspects of general ethnographic design to try to analyse…

  14. Prototype Theory and Classical Theory:An Explanation and Comparison

    Institute of Scientific and Technical Information of China (English)



    This paper discusses two different ways to understand categorization, which are classical theory and prototype theory. There is a deep exploration on how to understand categories, and different theoretical backgrounds of the two categorization the⁃ories. Furthermore, it reviews the limitations and advantages of both theories. And the comparison of the theories gives a clearer angle to understand their similarities and differences.

  15. Comparison and Contrast between First and Second Language Learning (United States)

    Akhter, Javed; Amin, Muhammad; Saeed, Faria; Abdullah, Shumaila; Muhammad, Khair


    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…

  16. Comparison of entropy difference in the cooling process

    Directory of Open Access Journals (Sweden)

    Ríos Cruellas G.


    Full Text Available The aim of this study is to create an overview of the various cooling technologies at room temperature. The energy absorbed during the cooling step is validated through an entropy analysis. The comparison involves vaporization, desorption of H2 of metal hydrides, isothermal expansion, magnetocaloric effect and chemical reaction.

  17. English Grammar Comparison:Descriptive Grammar vs. Prescriptive Grammar

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-wen; LI Yi-an


    English grammar is thought as one of the most important parts in both language learning and teaching. While few peo⁃ple know there is more than one kind of English grammar. This essay provides the features and comparison between two com⁃monly used English grammar, namely descriptive grammar and prescriptive grammar, and assist English teachers to explore further in grammar teaching.

  18. Neuroticism and responses to social comparison among cancer patients

    NARCIS (Netherlands)

    Buunk, Abraham P.; Brakel, Thecla M.; Bennenbroek, Femke T. C.; Stiegelis, Heidi E.; Sanderman, Robbert; Van den Bergh, Alfons C. M.; Hagedoorn, Mariet


    The present study examined how the effects of three audiotapes containig different types of social comparison information on the mood of cancer patients depended on the level of neuroticism. On the procedural tape, a man and woman discussed the process of radiation therapy, on the emotion tape, they

  19. Library Research: A Domain Comparison of Two Library Journals (United States)

    Davies, Karen; Thiele, Jennifer


    Research articles published by the "Community & Junior College Libraries" journal and the "College & Undergraduate Libraries" journal were analyzed to determine their domain. The discussion includes a comparison of past domain studies with the current research. The researchers found the majority of articles (52%) in the…

  20. Comparison of ICD-10 and Gillberg's Criteria for Asperger Syndrome. (United States)

    Leekam, Susan; Libby, Sarah; Wing, Lorna; Gould, Judith; Gillberg, Christopher


    This study compared the ICD-10 criteria for Asperger syndrome with those suggested by Gillberg with 200 children and adults who met ICD-10 criteria for autism. Comparison indicated only three subjects met ICD-10 criteria for Asperger syndrome whereas 91 met Gillberg's criteria. The discrepancy appeared due to the specific "normal development"…

  1. The Santa Barbara Cluster Comparison Project: A Comparison of Cosmological Hydrodynamics Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Frenk, C. S.; White, S. D. M.; Bode, P.; Bond, J. R.; Bryan, G. L.; Cen, R.; Couchman, H. M. P.; Evrard, A. E.; Gnedin, N.; Jenkins, A. (and others)


    We have simulated the formation of an X-ray cluster in a cold dark matter universe using 12 different codes. The codes span the range of numerical techniques and implementations currently in use, including smoothed particle hydrodynamics (SPH) and grid methods with fixed, deformable, or multilevel meshes. The goal of this comparison is to assess the reliability of cosmological gasdynamical simulations of clusters in the simplest astrophysically relevant case, that in which the gas is assumed to be nonradiative. We compare images of the cluster at different epochs, global properties such as mass, temperature and X-ray luminosity, and radial profiles of various dynamical and thermodynamical quantities. On the whole, the agreement among the various simulations is gratifying, although a number of discrepancies exist. Agreement is best for properties of the dark matter and worst for the total X-ray luminosity. Even in this case, simulations that adequately resolve the core radius of the gas distribution predict total X-ray luminosities that agree to within a factor of 2. Other quantities are reproduced to much higher accuracy. For example, the temperature and gas mass fraction within the virial radius agree to within about 10%, and the ratio of specific dark matter kinetic to gas thermal energies agree to within about 5%. Various factors, including differences in the internal timing of the simulations, contribute to the spread in calculated cluster properties. Based on the overall consistency of results, we discuss a number of general properties of the cluster we have modeled. (c) 1999 The American Astronomical Society.

  2. Multicode comparison of selected source-term computer codes

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, O.W.; Parks, C.V.; Renier, J.P.; Roddy, J.W.; Ashline, R.C.; Wilson, W.B.; LaBauve, R.J.


    This report summarizes the results of a study to assess the predictive capabilities of three radionuclide inventory/depletion computer codes, ORIGEN2, ORIGEN-S, and CINDER-2. The task was accomplished through a series of comparisons of their output for several light-water reactor (LWR) models (i.e., verification). Of the five cases chosen, two modeled typical boiling-water reactors (BWR) at burnups of 27.5 and 40 GWd/MTU and two represented typical pressurized-water reactors (PWR) at burnups of 33 and 50 GWd/MTU. In the fifth case, identical input data were used for each of the codes to examine the results of decay only and to show differences in nuclear decay constants and decay heat rates. Comparisons were made for several different characteristics (mass, radioactivity, and decay heat rate) for 52 radionuclides and for nine decay periods ranging from 30 d to 10,000 years. Only fission products and actinides were considered. The results are presented in comparative-ratio tables for each of the characteristics, decay periods, and cases. A brief summary description of each of the codes has been included. Of the more than 21,000 individual comparisons made for the three codes (taken two at a time), nearly half (45%) agreed to within 1%, and an additional 17% fell within the range of 1 to 5%. Approximately 8% of the comparison results disagreed by more than 30%. However, relatively good agreement was obtained for most of the radionuclides that are expected to contribute the greatest impact to waste disposal. Even though some defects have been noted, each of the codes in the comparison appears to produce respectable results. 12 figs., 12 tabs.

  3. Finding faults: analogical comparison supports spatial concept learning in geoscience. (United States)

    Jee, Benjamin D; Uttal, David H; Gentner, Dedre; Manduca, Cathy; Shipley, Thomas F; Sageman, Bradley


    A central issue in education is how to support the spatial thinking involved in learning science, technology, engineering, and mathematics (STEM). We investigated whether and how the cognitive process of analogical comparison supports learning of a basic spatial concept in geoscience, fault. Because of the high variability in the appearance of faults, it may be difficult for students to learn the category-relevant spatial structure. There is abundant evidence that comparing analogous examples can help students gain insight into important category-defining features (Gentner in Cogn Sci 34(5):752-775, 2010). Further, comparing high-similarity pairs can be especially effective at revealing key differences (Sagi et al. 2012). Across three experiments, we tested whether comparison of visually similar contrasting examples would help students learn the fault concept. Our main findings were that participants performed better at identifying faults when they (1) compared contrasting (fault/no fault) cases versus viewing each case separately (Experiment 1), (2) compared similar as opposed to dissimilar contrasting cases early in learning (Experiment 2), and (3) viewed a contrasting pair of schematic block diagrams as opposed to a single block diagram of a fault as part of an instructional text (Experiment 3). These results suggest that comparison of visually similar contrasting cases helped distinguish category-relevant from category-irrelevant features for participants. When such comparisons occurred early in learning, participants were more likely to form an accurate conceptual representation. Thus, analogical comparison of images may provide one powerful way to enhance spatial learning in geoscience and other STEM disciplines.

  4. Does social comparison make a difference? Optimism as a moderator of the relation between comparison level and academic performance

    NARCIS (Netherlands)

    Gibbons, FX; Blanton, H; Gerrard, M; Buunk, B; Eggleston, T


    Previous research has demonstrated that poor academic performance is associated with a downward shift in preferred level of academic comparison level (ACL). The current study assessed the long-term impact of this downward shift on the academic performance of college students and also examined the ex

  5. SUPPLEMENTARY COMPARISON Final report on EUROMET.L-S18 (EUROMET Project 905): Comparison of squareness measurements (United States)

    Mokros, Jiri


    A bilateral comparison has been undertaken between two European national metrology institutes (NMIs) in the subject field of squareness measurement. Specifically, both NMIs made measurements of a rectangular squareness standard, made of granite. Both participants made measurements of the internal angle at a defined position along the measuring faces, as well as measurement of the corresponding straightness profiles on the two adjoining sides. The report lists the results obtained by both participants, as well as an analysis of the results and their uncertainties. The results are in good agreement with one another. This bilateral comparison followed the same technical protocol as a previous supplementary comparison (EUROMET.L-S10). 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 The final report has been peer-reviewed and approved for publication by EURAMET, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  6. Student Tuition Charges: Comparisons, Options, and Implications and An Appendix to Student Tuition Charges: Comparisons, Options, and Implications. (United States)

    Diaz, Porfirio R.

    National and state comparisons of tuition and fee charges, as well as various policy options presented to the New Mexico Commission on Higher Education, are provided. An introduction to tuition and fee calculation is followed by definitions of tuition, required student fees, and student residency status. A study of tuition and fees at New Mexico…

  7. Final report on supplementary comparison COOMET.L-S10: Comparison of length standards for measuring gear parameters (United States)

    Makarevich, V.


    The COOMET Project No 507/BY/10, 'Supplementary comparison of length standards for measuring gear parameters', KCDB Reference COOMET.L-S10, was organized by the COOMET Technical Committee TC 1.5 'Length and Angle'. This comparison started in September 2010 and finished in September 2011. It was piloted by the Belarusian State Institute of Metrology, BelGIM, Minsk, the Republic of Belarus, with VNIIMS (Moscow, Russia) as the other participant. The transfer standard was a gear involute master provided by BelGIM. This standard has two base circle radii of 150 mm and 60 mm, and corresponding profiles on the left and on the right. The involute profile was measured from root towards tip of the tooth. The scanning was performed in automatic mode along the mid-section of the base cylinder over the complete estimation range, with a scanning speed of 2 mm s-1. The software program GEAR PRO involute was used to determine three parameters: the total profile deviation, the profile form deviation and the profile slope deviation. Each participant performed ten measurements for each of two involute profiles with basic circle radius of 150 mm and 60 mm, respectively. The measurement result for each parameter was calculated as a mean value from the ten measurements. The comparison results demonstrate that the measured values are consistent with the stated uncertainties and that the measurement standards under comparison are equivalent. 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 The final report has been peer-reviewed and approved for publication by COOMET, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  8. A comparison of verbal and numerical judgments in the analytic hierarchy process

    NARCIS (Netherlands)

    Huizingh, EKRE; Vrolijk, HCJ


    In the Analytic Hierarchy Process (AHP), decision makers make pairwise comparisons of alternatives and criteria. The AHP allows to make these pairwise comparisons verbally or numerically. Although verbal statements are intuitively attractive for preference elicitation, there is overwhelming evidence

  9. The $K$-groups and the index theory of certain comparison $C^*$-algebras

    CERN Document Server

    Monthubert, Bertrand


    We compute the $K$-theory of comparison $C^*$-algebra associated to a manifold with corners. These comparison algebras are an example of the abstract pseudodifferential algebras introduced by Connes and Moscovici \\cite{M3}. Our calculation is obtained by showing that the comparison algebras are a homomorphic image of a groupoid $C^*$-algebra. We then prove an index theorem with values in the $K$-theory groups of the comparison algebra.

  10. The effect of mindset on assimilative and contrastive social comparison outcomes and body image


    Wanic, Rebekah Amelie


    Social comparisons can alter self-evaluations in multiple ways. Recent research highlights the role of an individual's mindset in moderating these comparison outcomes. Mussweiler's (2003) selective accessibility model (SAM) predicts that initial perceptions of either similarity or dissimilarity with the comparison target will lead to differential outcomes. A similarity mindset is predicted to move self-evaluations in the direction of the comparison target and promote assimilation whereas a di...

  11. Examining a model of dispositional mindfulness, body comparison, and body satisfaction

    NARCIS (Netherlands)

    Dijkstra, Pieternel; Barelds, Dick P. H.


    The present study examined the links between dispositional mindfulness, body comparison, and body satisfaction. It was expected that mindfulness would be associated with less body comparison and more body satisfaction. Two models were tested: one exploring body comparison as a mediator between mindf

  12. Upward and Downward: Social Comparison Processing of Thin Idealized Media Images (United States)

    Tiggemann, Marika; Polivy, Janet


    The present study aimed to investigate the role of social comparison processing in women's responses to thin idealized images. In particular, it was predicted that comparison with the images on the basis of appearance would lead to more negative outcomes than comparison on the basis of intelligence. A sample of 114 women viewed fashion magazine…

  13. Differential Social Comparison Processes in Women with and without Eating Disorder Symptoms (United States)

    Corning, Alexandra F.; Krumm, Angela J.; Smitham, Lora A.


    On the basis of predictions from social comparison theory (L. Festinger, 1954) and informed by findings from the social comparison and eating disorder literatures, hypotheses were tested regarding the social comparison behaviors of women with eating disorder symptoms and their asymptomatic peers. Results indicated differentiating social-cognitive…

  14. Phantom Behavioral Assimilation Effects : Systematic Biases in Social Comparison Choice Studies

    NARCIS (Netherlands)

    Marsh, Herbert W.; Seaton, Marjorie; Kuyper, Hans; Dumas, Florence; Huguet, Pascal; Regner, Isabelle; Buunk, Abraham P.; Monteil, Jean-Marc; Gibbons, Frederick X.


    Consistent with social comparison theory (SCT), Blanton, Buunk, Gibbons, and Kuyper (1999) and Huguet, Dumas, Monteil, and Genestoux (2001) found that students tended to choose comparison targets who slightly outperformed them (i.e., upward comparison choices), and this had a beneficial effect on su

  15. Student distress in clinical workplace learning: differences in social comparison behaviours. (United States)

    Janet Raat, A N; Schönrock-Adema, Johanna; van Hell, E Ally; Kuks, Jan B M; Cohen-Schotanus, Janke


    In medical education, student distress is known to hamper learning and professional development. To address this problem, recent studies aimed at helping students cope with stressful situations. Undergraduate students in clinical practice frequently use experiences of surrounding peers to estimate their abilities to master such challenging situations. This use of the experiences of others, known as social comparison, may affect student distress both positively and negatively. To find characteristics of a beneficial use of social comparison, we examined differences in comparison behaviours between students expressing low and high levels of distress. The participants in our study, response rate 93% (N = 301/321), were all medical students in their first year in clinical practice. They completed the General Health Questionnaire (GHQ-12) to measure distress, and three separate questionnaires to measure: (1) orientation to comparison, (2) motive for comparison, and (3) interpretation of comparison. Differences were analysed using multivariate analysis of variance. Although all students were oriented towards social comparison, the analyses showed that this orientation was less apparent among low-distress students. Besides, the low-distress students were less inclined to use motives indicative for comparisons with peers perceived as performing worse and were less negative in the interpretations of their comparisons. As social comparison is frequently used among all students, we recommend to make them aware of their comparison behaviours and inform them about the pros and cons of the distinguished aspects of the comparison process.

  16. Social comparison : The end of a theory and the emergence of a field

    NARCIS (Netherlands)

    Buunk, Abraham P.; Gibbons, Frederick X.


    The past and current states of research on social comparison are reviewed with regard to a series of major theoretical developments that have occurred in the past 5 decades. These are, in chronological order: (1) classic social comparison theory, (2) fear-affiliation theory, (3) downward comparison

  17. "How Long Was Your Poem?" Social Comparison among Junior High School Students (United States)

    Tholander, Michael


    The present article focuses on in situ social comparison among junior high school students. Rather than studying social comparison as an individual phenomenon in experimental situations, which has been common in previous research, the study analyzes social comparison as a real-life social practice. The results show that the practice of social…

  18. A comparison of ionospheric model predictions with MITHRAS observations (United States)

    Schunk, Robert W.


    MITHRAS is a coordinated multiradar program to study the interactions between the magnetosphere, ionosphere, and thermosphere, as well as the phenomena that result from these interactions. The program is based on a data set acquired by the Chatanika, Millstone Hill, and Eiscat incoherent scatter radars. A large portion of the data is unique in that it was the only time when the radars, well separated in local and magnetic time, simultaneously probed the high latitude ionosphere. Our effect concerned model data comparisons. Specifically, we compared the predictions of our three-dimensional, time dependent model of the high latitude ionosphere with MITHRAS data sets. Of particular interest were the variations of the ionosphere with altitude, latitude, longitude, universal time, season, and magnetic activity. Model data comparisons enabled us to determine the adequacy of our current understanding of high latitude ionosphere dynamics as well as certain magnetosphere ionosphere atmosphere coupling processes.

  19. An Affordability Comparison Tool (ACT) for Space Transportation (United States)

    McCleskey, C. M.; Bollo, T. R.; Garcia, J. L.


    NASA bas recently emphasized the importance of affordability for Commercial Crew Development Program (CCDP), Space Launch Systems (SLS) and Multi-Purpose Crew Vehicle (MPCV). System architects and designers are challenged to come up with architectures and designs that do not bust the budget. This paper describes the Affordability Comparison Tool (ACT) analyzes different systems or architecture configurations for affordability that allows for a comparison of: total life cycle cost; annual recurring costs, affordability figures-of-merit, such as cost per pound, cost per seat, and cost per flight, as well as productivity measures, such as payload throughput. Although ACT is not a deterministic model, the paper develops algorithms and parametric factors that use characteristics of the architectures or systems being compared to produce important system outcomes (figures-of-merit). Example applications of outcome figures-of-merit are also documented to provide the designer with information on the relative affordability and productivity of different space transportation applications.

  20. Skeletal response to simulated weightlessness - A comparison of suspension techniques (United States)

    Wronski, T. J.; Morey-Holton, E. R.


    Comparisons are made of the skeletal response of rats subjected to simulated weightlessness by back or tail suspension. In comparison to pair-fed control rats, back-suspended rats failed to gain weight whereas tail-suspended rats exhibited normal weight gain. Quantitative bone histomorphometry revealed marked skeletal abnormalities in the proximal tibial metaphysis of back-suspended rats. Loss of trabecular bone mass in these animals was due to a combination of depressed longitudinal bone growth, decreased bone formation, and increased bone resorption. In contrast, the proximal tibia of tail-suspended rats was relatively normal by these histologic criteria. However, a significant reduction trabecular bone volume occurred during 2 weeks of tail suspension, possibly due to a transient inhibition of bone formation. The findings indicate that tail suspension may be a more appropriate model for evaluating the effects of simulated weightlessness on skeletal homeostasis.