Science.gov

Sample records for electron-proton interactions

  1. Electron-proton spectrometer

    NASA Technical Reports Server (NTRS)

    Winckler, J. R.

    1973-01-01

    An electron-proton spectrometer was designed to measure the geomagnetically trapped radiation in a geostationary orbit at 6.6 earth radii in the outer radiation belt. This instrument is to be flown on the Applications Technology Satellite-F (ATS-F). The electron-proton spectrometer consists of two permanent magnet surface barrier detector arrays and associated electronics capable of selecting and detecting electrons in three energy ranges: (1) 30-50 keV, (2) 150-200 keV, and (3) 500 keV and protons in three energy ranges. The electron-proton spectrometer has the capability of measuring the fluxes of electrons and protons in various directions with respect to the magnetic field lines running through the satellite. One magnet detector array system is implemented to scan between EME north and south through west, sampling the directional flux in 15 steps. The other magnet-detector array system is fixed looking toward EME east.

  2. Calculation of effective atomic number and electron density of essential biomolecules for electron, proton, alpha particle and multi-energetic photon interactions

    NASA Astrophysics Data System (ADS)

    Kurudirek, Murat; Onaran, Tayfur

    2015-07-01

    Effective atomic numbers (Zeff) and electron densities (Ne) of some essential biomolecules have been calculated for total electron interaction, total proton interaction and total alpha particle interaction using an interpolation method in the energy region 10 keV-1 GeV. Also, the spectrum weighted Zeff for multi-energetic photons has been calculated using Auto-Zeff program. Biomolecules consist of fatty acids, amino acids, carbohydrates and basic nucleotides of DNA and RNA. Variations of Zeff and Ne with kinetic energy of ionizing charged particles and effective photon energies of heterogeneous sources have been studied for the given materials. Significant variations in Zeff and Ne have been observed through the entire energy region for electron, proton and alpha particle interactions. Non-uniform variation has been observed for protons and alpha particles in low and intermediate energy regions, respectively. The maximum values of Zeff have found to be in higher energies for total electron interaction whereas maximum values have found to be in relatively low energies for total proton and total alpha particle interactions. When it comes to the multi-energetic photon sources, it has to be noted that the highest Zeff values were found at low energy region where photoelectric absorption is the pre-dominant interaction process. The lowest values of Zeff have been shown in biomolecules such as stearic acid, leucine, mannitol and thymine, which have highest H content in their groups. Variation in Ne seems to be more or less the same with the variation in Zeff for the given materials as expected.

  3. Electron/proton spectrometer certification documentation analyses

    NASA Technical Reports Server (NTRS)

    Gleeson, P.

    1972-01-01

    A compilation of analyses generated during the development of the electron-proton spectrometer for the Skylab program is presented. The data documents the analyses required by the electron-proton spectrometer verification plan. The verification plan was generated to satisfy the ancillary hardware requirements of the Apollo Applications program. The certification of the spectrometer requires that various tests, inspections, and analyses be documented, approved, and accepted by reliability and quality control personnel of the spectrometer development program.

  4. Calibration of the electron-proton spectrometer

    NASA Technical Reports Server (NTRS)

    Cash, B. L.

    1972-01-01

    The principal function of the sensor used in the electron-proton spectrometer is to provide a signal which can be used to determine the energy and indicate the type of an incident particle. Two techniques are employed to resolve the particle intensity in different energy regions. The first employs a moderator surrounding each detector to provide a nominal lower limit to the energy of a particle which can be detected. The second technique utilizes a pulse height discriminator to identify those particles entering a detector whose energy is (1) sufficiently high that it exceeds the discriminator level if the particle is stopped in the detector, or (2) sufficiently low that the ionization rate causes the discrimination level to be exceeded for paths through the detector shorter than the particle range.

  5. Preferential positron heating and acceleration by synchrotron maser instabilities in relativistic positron-electron-proton plasmas

    NASA Technical Reports Server (NTRS)

    Hoshino, Masahiro; Arons, Jonathan

    1991-01-01

    A new process of the preferential strong heating of positrons through the ion synchrotron maser instability in positron-electron-proton magnetized plasmas is investigated using particle-in-cell simulations. It is shown that the positrons form a nonthermal power-law-like energy distribution via their gyroresonant interaction with the extraordinary modes emitted by the ions. It is noted that this process may be of significance in connection with the shock excitation of nonthermal synchrotron radiation from astrophysical systems powered by relativistic outflows from compact central objects, e.g., supernova remnants powered by pulsars and jets from active galactic nuclei.

  6. Radiative corrections to polarization observables in electron-proton scattering

    NASA Astrophysics Data System (ADS)

    Borisyuk, Dmitry; Kobushkin, Alexander

    2014-08-01

    We consider radiative corrections to polarization observables in elastic electron-proton scattering, in particular, for the polarization transfer measurements of the proton form factor ratio μGE/GM. The corrections are of two types: two-photon exchange (TPE) and bremsstrahlung (BS); in the present work we pay special attention to the latter. Assuming small missing energy or missing mass cutoff, the correction can be represented in a model-independent form, with both electron and proton radiation taken into account. Numerical calculations show that the contribution of the proton radiation is not negligible. Overall, at high Q2 and energies, the total correction to μGE/GM grows, but is dominated by TPE. At low energies both TPE and BS may be significant; the latter amounts to ˜0.01 for some reasonable cut-off choices.

  7. A coherent analysis of elastic electron-proton scattering data

    NASA Astrophysics Data System (ADS)

    Bernauer, Jan

    2016-09-01

    The extraction of form factors and radii from scattering data is a treacherous business, and it is easy to bias the result with the choice of an unsuitable fit function. In the first part of the talk, I will present our analysis of the Mainz and world data sets, and the checks we have made to ensure that the results are accurate and unbiased. Recently, several authors have reanalyzed the Mainz and world data sets on electron-proton scattering, with the aim to extract the proton charge radius. The results fall into two groups: radii around 0.88 fm and around 0.84 fm, respectively. We find that the latter group typically is affected by various problems, discussed in the second part of the talk.

  8. Electron-proton spectrometer: Summary for critical design review

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The electron-proton spectrometer (EPS) is mounted external to the Skylab module complex on the command service module. It is designed to make a 2 pi omni-directional measurement of electrons and protons which result from solar flares or enhancement of the radiation belts. The EPS data will provide accurate radiation dose information so that uncertain Relative biological effectiveness factors are eliminated by measuring the external particle spectra. Astronaut radiation safety, therefore, can be ensured, as the EPS data can be used to correct or qualify radiation dose measurements recorded by other radiation measuring instrumentation within the Skylab module complex. The EPS has the capability of measuring and extremely wide dynamic radiation dose rate range, approaching 10 to the 7th power. Simultaneously the EPS has the capability to process data from extremely high radiation fields such as might be encountered in the wake of an intense solar flare.

  9. Electron proton two-stream instability at the PSR.

    SciTech Connect

    Macek, R. J.; Browman, A.; Fitzgerald, D.; McCrady, R.; Merrill, F.; Plum, M.; Spickermann, T.; Wang, T. S.; Griffin, J.; Ng, K. Y.; Wildman, D.; Harkay, K.; Kustom, R.; Rosenberg, R.

    2002-02-19

    A strong, fast, transverse instability has long been observed at the Los Alamos Proton Storage Ring (PSR) where it is a limiting factor on peak intensity. Most of the available evidence, based on measurements of the unstable proton beam motion, is consistent with an electron-proton two-stream instability. The need for higher beam intensity at PSR [1] and for future high-intensity, proton drivers has motivated a multi-lab collaboration (LANL, ANL, FNAL, LBNL, BNL, ORNL, and PPPL) to coordinate research on the causes, dynamics and cures for this instability. Important characteristics of the electron cloud were recently measured with retarding field electron analyzers and various collection electrodes. Suppression of the electron cloud formation by TiN coatings has confirmed the importance of secondary emission processes in its generation. New tests of potential controls included dual harmonic rf, damping by higher order multipoles, damping by X,Y coupling and the use of inductive inserts to compensate longitudinal space charge forces. With these controls and higher rf voltage the PSR has accumulated stable beam intensity up to 9.7 {micro}C/pulse (6 x 10{sup 13} protons), which is a 60% increase over the previous maximum.

  10. Strange Quark Contributions to Parity-Violating Asymmetries in the Forward G0 Electron-Proton Scattering Experiment

    SciTech Connect

    David Armstrong; Francois Arvieux; Razmik Asaturyan; Todd Averett; Stephanie Bailey; Guillaume Batigne; Douglas Beck; Elizabeth Beise; Jay Benesch; Louis Bimbot; James Birchall; Angela Biselli; Peter Bosted; Elodie Boukobza; Herbert Breuer; Roger Carlini; R. Carr; Nicholas Chant; Yu-Chiu Chao; Swapan Chattopadhyay; Russell Clark; Silviu Covrig; Anthony Cowley; Daniel Dale; C. Davis; Willie Falk; John Finn; Tony Forest; Gregg Franklin; Christophe Furget; David Gaskell; Joseph Grames; Keith Griffioen; Klaus Grimm; Benoit Guillon; Hayko Guler; Lars Hannelius; R. Hasty; A. Hawthorne Allen; Tanja Horn; Kathleen Johnston; Mark Jones; Peter Kammel; Reza Kazimi; Paul King; Ameya Kolarkar; Elie Korkmaz; Wolfgang Korsch; Serge Kox; Joachim Kuhn; Jeff Lachniet; Lawrence Lee; Jason Lenoble; Eric Liatard; J. Liu; Berenice Loupias; A. Lung; Glen MacLachlan; Dominique Marchand; J.W. Martin; Kenneth McFarlane; Daniella Mckee; Robert McKeown; Fernand Merchez; Hamlet Mkrtchyan; Bryan Moffit; M. Morlet; Itaru Nakagawa; Kazutaka Nakahara; Melissa Nakos; Retief Neveling; Silvia Niccolai; S. Ong; Shelley Page; Vassilios Papavassiliou; Stephen Pate; Sarah Phillips; Mark Pitt; Benard Poelker; Tracy Porcelli; Gilles Quemener; Brian Quinn; William Ramsay; Aamer Rauf; Jean-Sebastien Real; Julie Roche; Philip Roos; Gary Rutledge; Jeffery Secrest; Neven Simicevic; G.R. Smith; Damon Spayde; Samuel Stepanyan; Marcy Stutzman; Vincent Sulkosky; Vardan Tadevosyan; Raphael Tieulent; Jacques Van de Wiele; Willem van Oers; Eric Voutier; William Vulcan; G. Warren; S.P. Wells; Steven Williamson; S.A. Wood; Chen Yan; Junho Yun; Valdis Zeps

    2005-06-01

    We have measured parity-violating asymmetries in elastic electron-proton scattering over the range of momentum transfers 0.12 < Q{sup 2} < 1.0 GeV{sup 2}. These asymmetries, arising from interference of the electromagnetic and neutral weak interactions, are sensitive to strange quark contributions to the currents of the proton. The measurements were made at JLab using a toroidal spectrometer to detect the recoiling protons from a liquid hydrogen target. The results indicate non-zero, Q{sup 2} dependent, strange quark contributions and provide new information beyond that obtained in previous experiments.

  11. Stopping-Power and Range Tables for Electrons, Protons, and Helium Ions

    National Institute of Standards and Technology Data Gateway

    SRD 124 Stopping-Power and Range Tables for Electrons, Protons, and Helium Ions (Web, free access)   The databases ESTAR, PSTAR, and ASTAR calculate stopping-power and range tables for electrons, protons, or helium ions. Stopping-power and range tables can be calculated for electrons in any user-specified material and for protons and helium ions in 74 materials.

  12. Proton radius from electron-proton scattering and chiral perturbation theory

    NASA Astrophysics Data System (ADS)

    Horbatsch, Marko; Hessels, Eric A.; Pineda, Antonio

    2017-03-01

    We determine the root-mean-square proton charge radius, Rp, from a fit to low-Q2 electron-proton elastic-scattering cross-section data with the higher moments fixed (within uncertainties) to the values predicted by chiral perturbation theory. We obtain Rp=0.855 (11 ) fm. This number falls between the value obtained from muonic hydrogen analyses and the CODATA value (based upon atomic hydrogen spectroscopy and electron-proton scattering determinations).

  13. Cooperative electrocatalytic alcohol oxidation with electron-proton-transfer mediators

    NASA Astrophysics Data System (ADS)

    Badalyan, Artavazd; Stahl, Shannon S.

    2016-07-01

    electron-proton-transfer mediators, such as TEMPO, may be used in combination with first-row transition metals, such as copper, to achieve efficient two-electron electrochemical processes, thereby introducing a new concept for the development of non-precious-metal electrocatalysts.

  14. Electron-Proton and High Energy Telescopes for Solar Orbiter

    NASA Astrophysics Data System (ADS)

    Kulkarni, Shrinivasrao R.; Grunau, Jan; Boden, Sebastian; Steinhagen, Jan; Martin, Cesar; Wimmer-Schweingruber, Robert F.; Boettcher, Stephan; Rodríguez-Pacheco, Javier; Seimetz, Lars; Schuster, Bjoern; Kulemzin, Alexander; Wetzel, Moritz; Ravanbakhsh, Ali

    2013-04-01

    The Energetic Particle Detector (EPD) suite for ESA's Solar Orbiter will provide key measurements to address particle acceleration at and near the Sun. The EPD suite consists of five sensors (STEIN, SIS, EPT, LET and HET). The University of Kiel in Germany is responsible for the design, development, and build of EPT and HET which are presented here. The Electron Proton Telescope (EPT) is designed to cleanly separate and measure electrons in the energy range from 20 - 400 keV and protons from 20 - 7000 keV. The Solar Orbiter EPT electron measurements from 20 - 400 keV will cover the gap with some overlap between suprathermal electrons measured by STEIN and high energy electrons measured by HET. The proton measurements from 20 -7000 keV will cover the gap between STEIN and LET. The Electron and Proton Telescope relies on the magnet/foil-technique. The High-Energy Telescope (HET) on ESA's Solar Orbiter mission, will measure electrons from 300 keV up to about 30 MeV, protons from 10 -100 MeV, and heavy ions from ~20 to 200 MeV/nuc. Thus, HET covers the energy range which is of specific interest for studies of the space environment and will perform the measurements needed to understand the origin of high-energy events at the Sun which occasionally accelerate particles to such high energies that they can penetrate the Earth's atmosphere and be measured at ground level (ground-level events). These measurement capabilities are reached by a combination of solid-state detectors and a scintillator calorimeter which allows use of the dE/dx vs. total E technique for particle identification and energy measurement. The upper limits on energy listed above refer to particles (ions) stopping in the scintillator and careful modeling of HET properties will allow discrimination of forward/backward penetrating particles in a wider energy range. Here we present the current development status of EPT-HET units focusing on the test and calibration results obtained with the demonstration

  15. Cooperative electrocatalytic alcohol oxidation with electron-proton-transfer mediators.

    PubMed

    Badalyan, Artavazd; Stahl, Shannon S

    2016-07-21

    electron-proton-transfer mediators, such as TEMPO, may be used in combination with first-row transition metals, such as copper, to achieve efficient two-electron electrochemical processes, thereby introducing a new concept for the development of non-precious-metal electrocatalysts.

  16. Measuring the Weak Charge of the Proton via Elastic Electron-Proton Scattering

    SciTech Connect

    Jones, Donald C.

    2015-10-01

    The Qweak experiment which ran in Hall C at Jefferson Lab in Newport News, VA, and completed data taking in May 2012, measured the weak charge of the proton QpW via elastic electron-proton scattering. Longitudinally polarized electrons were scattered from an unpolarized liquid hydrogen target. The helicity of the electron beam was flipped at approximately 1 kHz between left and right spin states. The Standard Model predicts a small parity-violating asymmetry of scattering rates between right and left helicity states due to the weak interaction. An initial result using 4% of the data was published in October 2013 [1] with a measured parity-violating asymmetry of -279 ± 35(stat) ± 31 (syst) ppb. This asymmetry, along with other data from parity-violating electron scattering experiments, provided the world's first determination of the weak charge of the proton. The weak charge of the proton was found to be pW = 0.064 ± 0.012, in good agreement with the Standard Model prediction of pW(SM) = 0.0708 ± 0.0003[2].

  17. Positron-proton to electron-proton elastic cross section ratios from CLAS

    NASA Astrophysics Data System (ADS)

    Adikaram, Dasuni; Rimal, Dipak; Weinstein, Larry; Raue, Brian

    2014-03-01

    There is a significant discrepancy between the ratio of the electromagnetic form factors of the proton measured by the Rosenbluth and the polarization transfer technique. The most likely explanation of this discrepancy is the inclusion of two-photon exchange (TPE) amplitude contributions to the elastic electron-proton cross section. The CLAS TPE experiment measured the TPE contribution in the wide range of Q2 and ɛ range using a comparison of positron-proton to electron-proton elastic cross sections (R = σ (e+ p) / σ (e- p)). Preliminary results will be presented, along with the estimations of systematic uncertainties. A detailed comparison of new results with previous R measurements and theoretical calculations will be presented. Implications of the CLAS TPE measurements on the elastic electron-proton cross section will be also discussed.

  18. Analysis of approximations used in calculations of radiative corrections to electron-proton scattering cross section

    NASA Astrophysics Data System (ADS)

    Gerasimov, R. E.; Fadin, V. S.

    2015-01-01

    An analysis of approximations used in calculations of radiative corrections to electron-proton scattering cross section is presented. We investigate the difference between the relatively recent Maximon and Tjon result and the Mo and Tsai result, which was used in the analysis of experimental data. We also discuss the proton form factors ratio dependence on the way we take into account radiative corrections.

  19. Test report: Electron-proton spectrometer qualification test unit, qualification test

    NASA Technical Reports Server (NTRS)

    Vincent, D. L.

    1972-01-01

    Qualification tests of the electron-proton spectrometer test unit are presented. The tests conducted were: (1) functional, (2) thermal/vacuum, (3) electromagnetic interference, (4) acoustic, (5) shock, (6) vibration, and (7) humidity. Results of each type of test are presented in the form of data sheets.

  20. A Physical Relationship Between Electron-Proton Temperature Equilibration and Mach Number in Fast Collisionless Shocks

    DTIC Science & Technology

    2007-01-01

    PHYSICAL RELATIONSHIP BETWEEN ELECTRON-PROTON TEMPERATURE EQUILIBRATION AND MACH NUMBER IN FAST COLLISIONLESS SHOCKS Parviz Ghavamian,1 J. Martin Laming,2...neutrals have had little time to equilibrate with electrons and 1 Department of Physics and Astronomy, Johns Hopkins University, Balti- more, MD; parviz

  1. Analysis of approximations used in calculations of radiative corrections to electron-proton scattering cross section

    SciTech Connect

    Gerasimov, R. E. Fadin, V. S.

    2015-01-15

    An analysis of approximations used in calculations of radiative corrections to electron-proton scattering cross section is presented. We investigate the difference between the relatively recent Maximon and Tjon result and the Mo and Tsai result, which was used in the analysis of experimental data. We also discuss the proton form factors ratio dependence on the way we take into account radiative corrections.

  2. Novel QCD Phenomena at Electron-Proton Colliders

    SciTech Connect

    Brodsky, Stanley J.; /SLAC /Durham U., IPPP

    2008-07-25

    I discuss several novel phenomenological features of QCD which are observable in deep inelastic lepton-nucleon and lepton-nucleus scattering. Initial- and final-state interactions from gluon exchange, normally neglected in the parton model, have a profound effect on QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, the diffractive contribution to deep inelastic scattering, and the breakdown of the pQCD Lam-Tung relation in Drell-Yan reactions. Leading-twist diffractive processes in turn lead to nuclear shadowing and non-universal antishadowing--physics not incorporated in the light-front wavefunctions of the nucleus computed in isolation.

  3. Simulation of electron-proton coupling with a Monte Carlo method: application to cytochrome c3 using continuum electrostatics.

    PubMed Central

    Baptista, A M; Martel, P J; Soares, C M

    1999-01-01

    A new method is presented for simulating the simultaneous binding equilibrium of electrons and protons on protein molecules, which makes it possible to study the full equilibrium thermodynamics of redox and protonation processes, including electron-proton coupling. The simulations using this method reflect directly the pH and electrostatic potential of the environment, thus providing a much closer and realistic connection with experimental parameters than do usual methods. By ignoring the full binding equilibrium, calculations usually overlook the twofold effect that binding fluctuations have on the behavior of redox proteins: first, they affect the energy of the system by creating partially occupied sites; second, they affect its entropy by introducing an additional empty/occupied site disorder (here named occupational entropy). The proposed method is applied to cytochrome c3 of Desulfovibrio vulgaris Hildenborough to study its redox properties and electron-proton coupling (redox-Bohr effect), using a continuum electrostatic method based on the linear Poisson-Boltzmann equation. Unlike previous studies using other methods, the full reduction order of the four hemes at physiological pH is successfully predicted. The sites more strongly involved in the redox-Bohr effect are identified by analysis of their titration curves/surfaces and the shifts of their midpoint redox potentials and pKa values. Site-site couplings are analyzed using statistical correlations, a method much more realistic than the usual analysis based on direct interactions. The site found to be more strongly involved in the redox-Bohr effect is propionate D of heme I, in agreement with previous studies; other likely candidates are His67, the N-terminus, and propionate D of heme IV. Even though the present study is limited to equilibrium conditions, the possible role of binding fluctuations in the concerted transfer of protons and electrons under nonequilibrium conditions is also discussed. The

  4. Single-spin asymmetries from two-photon exchange in elastic electron proton scattering

    SciTech Connect

    A.V. Afanasev; N.P. Merenkov

    2005-02-01

    The parity-conserving single-spin beam asymmetry of elastic electron-proton scattering is induced by an absorptive part of the two-photon exchange amplitude. We demonstrate that this asymmetry has logarithmic and double-logarithmic enhancement due to contributions of hard collinear quasi-real photons. An optical theorem is used to evaluate the asymmetry in terms of the total photoproduction cross section on the proton.

  5. Two-Photon Exchange in Elastic Electron-Proton Scattering: A QCD Factorization Approach

    SciTech Connect

    Kivel, Nikolai; Vanderhaeghen, Marc

    2009-08-28

    We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer Q{sup 2}. It is shown that the leading two-photon exchange amplitude behaves as 1/Q{sup 4}, and can be expressed in a model independent way in terms of the leading twist nucleon distribution amplitudes. Using several models for the nucleon distribution amplitudes, we provide estimates for existing data and for ongoing experiments.

  6. A measurement of two-photon exchange in unpolarized elastic electron-proton scattering

    NASA Astrophysics Data System (ADS)

    Yurov, Mikhail

    2016-03-01

    Jefferson Lab experiment E05-017 was designed to study 2-photon exchange contributions to elastic electron-proton scattering over a wide kinematic range. By detecting the scattered proton instead of the electron these measurements will be very sensitive to the ɛ dependence of the cross section and consequently the ratio GE/GM. The goals of the experiment, the experimental technique and the kinematic range will be presented. The analysis sequence and results of the early steps will be outlined.

  7. Test report: Vibration testing of the electron/proton spectrometer structural test unit

    NASA Technical Reports Server (NTRS)

    Vincent, D. L.

    1972-01-01

    The structural test unit of the electron-proton spectrometer was tested to a random vibration spectra and to a sinusoidal resonant search to comply with the requirements of a verification plan for the spectrometer. The test item consisted of mass simulated electronic and printed circuit boards mounted in a flight type electronic housing. The arrangement, center of gravity, and weight were as proposed for flight units.

  8. Two-photon exchange correction in elastic unpolarized electron-proton scattering at small momentum transfer

    NASA Astrophysics Data System (ADS)

    Tomalak, O.; Vanderhaeghen, M.

    2016-01-01

    We evaluate the two-photon exchange (TPE) correction to the unpolarized elastic electron-proton scattering at small momentum transfer Q2 . We account for the inelastic intermediate states approximating the double virtual Compton scattering by the unpolarized forward virtual Compton scattering. The unpolarized proton structure functions are used as input for the numerical evaluation of the inelastic contribution. Our calculation reproduces the leading terms in the Q2 expansion of the TPE correction and goes beyond this approximation by keeping the full Q2 dependence of the proton structure functions. In the range of small momentum transfer, our result is in good agreement with the empirical TPE fit to existing data.

  9. A search for excited fermions in electron-proton collisions at HERA

    NASA Astrophysics Data System (ADS)

    Derrick, M.; Krakauer, D.; Magill, S.; Musgrave, B.; Repond, J.; Schlereth, J.; Stanek, R.; Talaga, R. L.; Thron, J.; Arzarello, F.; Ayad, R.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Bruni, P.; Romeo, G. Cara; Castellini, G.; Chiarini, M.; Cifarelli, L.; Cindolo, F.; Ciralli, F.; Contin, A.; D'Auria, S.; Frasconi, F.; Gialas, I.; Giusti, P.; Iacobucci, G.; Laurenti, G.; Levi, G.; Margotti, A.; Massam, T.; Nania, R.; Nemoz, C.; Palmonari, F.; Polini, A.; Sartorelli, G.; Timellini, R.; Garcia, Y. Zamora; Zichichi, A.; Bargende, A.; Crittenden, J.; Desch, K.; Diekmann, B.; Doeker, T.; Eckart, M.; Feld, L.; Frey, A.; Geerts, M.; Geitz, G.; Grothe, M.; Hartmann, H.; Haun, D.; Heinloth, K.; Hilger, E.; Jakob, H.-P.; Katz, U. F.; Mari, S. M.; Mass, A.; Mengel, S.; Mollen, J.; Paul, E.; Rembser, Ch.; Schattevoy, R.; Schneider, J.-L.; Schramm, D.; Stamm, J.; Wedemeyer, R.; Campbell-Robson, S.; Cassidy, A.; Dyce, N.; Foster, B.; George, S.; Gilmore, R.; Heath, G. P.; Heath, H. F.; Llewellyn, T. J.; Morgado, C. J. S.; Norman, D. J. P.; O'Mara, J. A.; Tapper, R. J.; Wilson, S. S.; Yoshida, R.; Rau, R. R.; Arneodo, M.; Iannotti, L.; Schioppa, M.; Susinno, G.; Bernstein, A.; Caldwell, A.; Parsons, J. A.; Ritz, S.; Sciulli, F.; Straub, P. B.; Wai, L.; Yang, S.; Borzemski, P.; Chwastowski, J.; Eskreys, A.; Piotrzkowski, K.; Zachara, M.; Zawiejski, L.; Adamczyk, L.; Bednarek, B.; Eskreys, K.; Jeleń, K.; Kisielewska, D.; Kowalski, T.; Rulikowska-Zarebska, E.; Suszycki, L.; Zajac, J.; Kedzierski, T.; Kotański, A.; Przybycień, M.; Bauerdick, L. A. T.; Behrens, U.; Bienlein, J. K.; Böttcher, S.; Coldewey, C.; Drews, G.; Flasiński, M.; Gilkinson, D. J.; Göttlicher, P.; Gutjahr, B.; Haas, T.; Hain, W.; Hasell, D.; Heßling, H.; Hultschig, H.; Iga, Y.; Joos, P.; Kasemann, M.; Klanner, R.; Koch, W.; Köpke, L.; Kötz, U.; Kowalski, H.; Kroger, W.; Krüger, J.; Labs, J.; Ladage, A.; Löhr, B.; Löwe, M.; Lüke, D.; Mańczak, O.; Ng, J. S. T.; Nickel, S.; Notz, D.; Ohrenberg, K.; Roco, M.; Rohde, M.; Roldán, J.; Schneekloth, U.; Schulz, W.; Selonke, F.; Stiliaris, E.; Voß, T.; Westphal, D.; Wolf, G.; Youngman, C.; Grabosch, H. J.; Leich, A.; Meyer, A.; Rethfeldt, C.; Schlenstedt, S.; Barbagli, G.; Pelfer, P.; Anzivino, G.; Maccarrone, G.; de Pasquale, S.; Qian, S.; Votano, L.; Bamberger, A.; Freidhof, A.; Poser, T.; Söldner-Rembold, S.; Schroeder, J.; Theisen, G.; Trefzger, T.; Brook, N. H.; Bussey, P. J.; Doyle, A. T.; Fleck, I.; Jamieson, V. A.; Saxon, D. H.; Utley, M. L.; Wilson, A. S.; Dannemann, A.; Holm, U.; Horstmann, D.; Kammerlocher, H.; Krebs, B.; Neumann, T.; Sinkus, R.; Wick, K.; Badura, E.; Burow, B. D.; Fürtjes, A.; Hagge, L.; Lohrmann, E.; Mainusch, J.; Milewski, J.; Nakahata, M.; Pavel, N.; Poelz, G.; Schott, W.; Terron, J.; Zetsche, F.; Bacon, T. C.; Beuselinck, R.; Butterworth, I.; Gallo, E.; Harris, V. L.; Hung, B. H.; Long, K. R.; Miller, D. B.; Morawitz, P. P. O.; Prinias, A.; Sedgbeer, J. K.; Whitfield, A. F.; Mallik, U.; McCliment, E.; Wang, M. Z.; Wang, S. M.; Wu, J. T.; Zhang, Y.; Cloth, P.; Filges, D.; An, S. H.; Hong, S. M.; Nam, S. W.; Park, S. K.; Suh, M. H.; Yon, S. H.; Imlay, R.; Kartik, S.; Kim, H.-J.; McNeil, R. R.; Metcalf, W.; Nadendla, V. K.; Barreiro, F.; Cases, G.; Graciani, R.; Hernández, J. M.; Hervás, L.; Labarga, L.; Del Peso, J.; Puga, J.; de Trocóniz, J. F.; Ikraiam, F.; Mayer, J. K.; Smith, G. R.; Corriveau, F.; Hanna, D. S.; Hartmann, J.; Hung, L. W.; Lim, J. N.; Matthews, C. G.; Patel, P. M.; Sinclair, L. E.; Stairs, D. G.; St. Laurent, M.; Ullmann, R.; Zacek, G.; Bashkirov, V.; Dolgoshein, B. A.; Stifutkin, A.; Bashindzhagyan, G. L.; Ermolov, P. F.; Gladilin, L. K.; Golubkov, Y. A.; Kobrin, V. D.; Kuzmin, V. A.; Proskuryakov, A. S.; Savin, A. A.; Shcheglova, L. M.; Solomin, A. N.; Zotov, N. P.; Bentvelsen, S.; Botje, M.; Chlebana, F.; Dake, A.; Engelen, J.; de Jong, P.; de Kamps, M.; Kooijman, P.; Kruse, A.; O'Dell, V.; Tenner, A.; Tiecke, H.; Verkerke, W.; Vreeswijk, M.; Wiggers, L.; de Wolf, E.; van Woudenberg, R.; Acosta, D.; Bylsma, B.; Durkin, L. S.; Honscheid, K.; Li, C.; Ling, T. Y.; McLean, K. W.; Murray, W. N.; Park, I. H.; Romanowski, T. A.; Seidlein, R.; Bailey, D. S.; Blair, G. A.; Byrne, A.; Cashmore, R. J.; Cooper-Sarkar, A. M.; Daniels, D.; Devenish, R. C. E.; Harnew, N.; Lancaster, M.; Luffman, P. E.; Lindemann, L.; McFall, J.; Nath, C.; Quadt, A.; Uijterwaal, H.; Walczak, R.; Wilson, F. F.; Yip, T.; Abbiendi, G.; Bertolin, A.; Brugnera, R.; Carlin, R.; Dal Corso, F.; de Giorgi, M.; Dosselli, U.; Limentani, S.; Morandin, M.; Posocco, M.; Stanco, L.; Stroili, R.; Voci, C.; Bulmahn, J.; Butterworth, J. M.; Feild, R. G.; Oh, B. Y.; Whitmore, J. J.; D'Agostini, G.; Iori, M.; Marini, G.; Mattioli, M.; Nigro, A.; Tassi, E.; Hart, J. C.; McCubbin, N. A.; Prytz, K.; Shah, T. P.; Short, T. L.; Barberis, E.; Cartiglia, N.; Dubbs, T.; Heusch, C.; van Hook, M.; Hubbard, B.; Lockman, W.; Rahn, J. T.; Sadrozinski, H. F.-W.; Seiden, A.; Biltzinger, J.; Seifert, R. J.; Walenta, A. H.; Zech, G.; Abramowicz, H.; Briskin, G.; Dagan, S.; Levy, A.; Hasegawa, T.; Hazumi, M.; Ishii, T.; Kuze, M.; Mine, S.; Nagasawa, Y.; Nagira, T.; Nakao, M.; Suzuki, I.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Chiba, M.; Hamatsu, R.; Hirose, T.; Homma, K.; Kitamura, S.; Nagayama, S.; Nakamitsu, Y.; Cirio, R.; Costa, M.; Ferrero, M. I.; Lamberti, L.; Maselli, S.; Peroni, C.; Sacchi, R.; Solano, A.; Staiano, A.; Dardo, M.; Bailey, D. C.; Bandyopadhyay, D.; Benard, F.; Brkic, M.; Crombie, M. B.; Gingrich, D. M.; Hartner, G. F.; Joo, K. K.; Levman, G. M.; Martin, J. F.; Orr, R. S.; Sampson, C. R.; Teuscher, R. J.; Catterall, C. D.; Jones, T. W.; Kaziewicz, P. B.; Lane, J. B.; Saunders, R. L.; Shulman, J.; Blankenship, K.; Kochocki, J.; Lu, B.; Mo, L. W.; Bogusz, W.; Charchula, K.; Ciborowski, J.; Gajewski, J.; Grzelak, G.; Kasprazak, M.; Krzyżanowski, M.; Muchorowski, K.; Nowak, R. J.; Pawlak, J. M.; Tymieniecka, T.; Wróblewski, A. K.; Zakrzewski, J. A.; Żarnecki, A. F.; Adamus, M.; Eisenberg, Y.; Glasman, C.; Karshon, U.; Revel, D.; Shapira, A.; Ali, I.; Behrens, B.; Dasu, S.; Fordham, C.; Foudas, C.; Goussiou, A.; Loveless, R. J.; Reeder, D. D.; Silverstein, S.; Smith, W. H.; Tsurugai, T.; Bhadra, S.; Frisken, W. R.; Furutani, K. M.

    1995-12-01

    A search for excited states of the standard model fermions was performed using the ZEUS detector at the HERA electron-proton collider, operating at a centre of mass energy of 296 GeV. In a sample corresponding to an integrated luminosity of 0.55 pb-1, no evidence was found for any resonant state decaying into final states composed of a fermion and a gauge boson. Limits on the coupling strength times branching ratio of excited fermions are presented for masses between 50 GeV and 250 GeV, extending previous search regions significantly.

  10. Effective field theory for large logarithms in radiative corrections to electron proton scattering

    NASA Astrophysics Data System (ADS)

    Hill, Richard J.

    2017-01-01

    Radiative corrections to elastic electron proton scattering are analyzed in effective field theory. A new factorization formula identifies all sources of large logarithms in the limit of large momentum transfer, Q2≫me2. Explicit matching calculations are performed through two-loop order. A renormalization analysis in soft-collinear effective theory is performed to systematically compute and resum large logarithms. Implications for the extraction of charge radii and other observables from scattering data are discussed. The formalism may be applied to other lepton-nucleon scattering and e+e- annihilation processes.

  11. Large Logarithms in the Beam Normal Spin Asymmetry of Elastic Electron--Proton Scattering

    SciTech Connect

    Andrei Afanasev; Mykola Merenkov

    2004-06-01

    We study a parity-conserving single-spin beam asymmetry of elastic electron-proton scattering induced by an absorptive part of the two-photon exchange amplitude. It is demonstrated that excitation of inelastic hadronic intermediate states by the consecutive exchange of two photons leads to logarithmic and double-logarithmic enhancement due to contributions of hard collinear quasi-real photons. The asymmetry at small electron scattering angles is expressed in terms of the total photoproduction cross section on the proton, and is predicted to reach the magnitude of 20-30 parts per million. At these conditions and fixed 4-momentum transfers, the asymmetry is rising logarithmically with increasing electron beam energy, following the high-energy diffractive behavior of total photoproduction cross section on the proton.

  12. End-to-end test of the electron-proton spectrometer

    NASA Technical Reports Server (NTRS)

    Cash, B. L.

    1972-01-01

    A series of end-to-end tests were performed to demonstrate the proper functioning of the complete Electron-Proton Spectrometer (EPS). The purpose of the tests was to provide experimental verification of the design and to provide a complete functional performance check of the instrument from the excitation of the sensors to and including the data processor and equipment test set. Each of the channels of the EPS was exposed to a calibrated beam of energetic particles, and counts were accumulated for a predetermined period of time for each of several energies. The counts were related to the known flux of particles to give a monodirectional response function for each channel. The measured response function of the test unit was compared to the response function determined for the calibration sensors from the data taken from the calibration program.

  13. Measuring the 2{gamma} Exchange Effect in Electron-Proton Scattering at CLAS

    SciTech Connect

    Bennett, Robert Paul

    2011-10-24

    Recent results from experiments at Jefferson Laboratory, Newport News VA, which measure the ratio of the electric to magnetic form factors of the proton, G{sub E}/G{sub M}, have forced us to reexamine the single photon exchange approximation in lepton-proton elastic scattering. Discrepancies between the ratio obtained via the time-tested Rosenbluth separation method and new polarization transfer measurements, which differ by as much as a factor of three, may be resolved by considering the effect of two photon exchange (TPE). Theoretical corrections for the TPE effect are difficult due to the large number of excited nucleon states that can contribute to the process. The TPE effect can, however, be determined directly by measuring the ratio of the positron-proton to electron-proton elastic scattering cross sections, R = {sigma}(e{sup +})/{sigma}(e{sup -}), since the TPE effect changes sign with the charge of the incident particle. The CLAS TPE experiment at Jefferson Laboratory, will determine the effect of two-photon exchange in elastic lepton-proton scattering by precisely measuring the ratio of positron-proton to electron-proton elastic cross sections over a large kinematic range (0.1<{epsilon}<0.96, 0.02{<=}Q{sup 2}{<=}2.0). We will accomplish this by directing the 5.5 GeV primary electron beam, provided by the Continuous Electron Beam Accelerator Facility (CEBAF), onto a set of radiators and converters to produce simultaneous and identical beams of electron and positrons. Acceptance and efficiency concerns are minimized by only considering the ratios of the elastic cross sections and switching polarity of magnets in the beam line and the spectrometer. Guided by the results of a short 2006 test run and extensive GEANT based modeling, new shielding and beam line components were designed to maximize luminosity. The unique experimental design and challenges of the TPE experiment and the projected luminosities will be presented.

  14. Measuring the 2-gamma Exchange Effect in Electron-Proton Scattering at CLAS

    SciTech Connect

    Bennett, Robert

    2011-10-01

    Recent results from experiments at Jefferson Laboratory, Newport News VA, which measure the ratio of the electric to magnetic form factors of the proton, G{sub E}/G{sub M}, have forced us to reexamine the single photon exchange approximation in lepton-proton elastic scattering. Discrepancies between the ratio obtained via the time-tested Rosenbluth separation method and new polarization transfer measurements, which differ by as much as a factor of three, may be resolved by considering the effect of two photon exchange (TPE). Theoretical corrections for the TPE effect are difficult due to the large number of excited nucleon states that can contribute to the process. The TPE effect can, however, be determined directly by measuring the ratio of the positron-proton to electron-proton elastic scattering cross sections, R = {sigma}(e{sup +})/{sigma}(e{sup -}), since the TPE effect changes sign with the charge of the incident particle. The CLAS TPE experiment at Jefferson Laboratory, will determine the effect of two-photon exchange in elastic lepton-proton scattering by precisely measuring the ratio of positron-proton to electron-proton elastic cross sections over a large kinematic range (0.1 < {var_epsilon} < 0.96, 0.02 {le} Q{sup 2} {le} 2.0). We will accomplish this by directing the 5.5 GeV primary electron beam, provided by the Continuous Electron Beam Accelerator Facility (CEBAF), onto a set of radiators and converters to produce simultaneous and identical beams of electron and positrons. Acceptance and efficiency concerns are minimized by only considering the ratios of the elastic cross sections and switching polarity of magnets in the beam line and the spectrometer. Guided by the results of a short 2006 test run and extensive GEANT based modeling, new shielding and beam line components were designed to maximize luminosity. The unique experimental design and challenges of the TPE experiment and the projected luminosities will be presented.

  15. Linear optics correction and observation of electron proton instability in the SNS accumulator ring

    NASA Astrophysics Data System (ADS)

    Liu, Zhengzheng

    The accumulator ring of the Spallation Neutron Source is a high intensity proton storage ring. The choice of its operating tunes is critical. There was a relatively large tune discrepancy ˜ 0.2 between model prediction and real measurement. As a consequence, it was not possible to set the lattice using the model calculation. The orbit response matrix (ORM) method, as programmed in the application code LOCO, was employed to solve the optics discrepancy and calibrate the linear model. Offline study shows that we can attribute most of the tune discrepancy to the errors of quadrupole magnet power supplies, which is up to 2.9%. The results and discussions of proved and potential optics improvement are presented in detail in the thesis. Due to the high intensity of proton beam and the similarity of SNS and PSR, collective instabilities, especially the electron-proton (e-p) instability, pose potential limitations on the peak intensity and therefore become major concerns in the SNS power-up plan. Therefore, although the e-p instability has not emerged in the normal neutron productions yet, we have manipulated the machine setting to observe it in a series of experiments. It shows that, the buncher voltage has little effect on instability threshold and that the instability has a strong dependence on proton bunch shape. Moreover, a potential mitigation of the e-p instability involves the use of a flat top current profile with a short tail. Detailed observation and discussion can be found in the thesis.

  16. Extended Measurement Capabilities of the Electron Proton Helium INstrument aboard SOHO - Understanding single detector count rates

    NASA Astrophysics Data System (ADS)

    Kühl, P.; Banjac, S.; Heber, B.; Labrenz, J.; Müller-Mellin, R.; Terasa, C.

    Forbush (1937) was the first to observe intensity decreases lasting for a few days utilizing ionization chambers. A number of studies on Forbush decreases (FDs) have been performed since then utilizing neutron monitors and space instrumentation. The amplitude of these variations can be as low as a few permil. Therefore intensity measurements need to be of high statistical accuracy. Richardson et al. (1996) suggested therefore to utilize the single counter measurements of the guard counters of the IMP 8 and Helios E6 instruments. Like the above mentioned instruments the Electron Proton Helium INstrument (EPHIN) provides single counting rates. During the extended solar minimum in 2009 its guard detector counted about 25000~counts/minute, allowing to determine intensity variations of less than 2 permil using 30 minute averages. We performed a GEANT 4 simulation of the instrument in order to determine the energy response of all single detectors. It is shown here that their energy thresholds are much lower than the ones of neutron monitors and therefore we developed a criterion that allows to investigate FDs during quiet time periods.

  17. Proton form factors and two-photon exchange in elastic electron-proton scattering

    SciTech Connect

    Nikolenko, D. M.; Arrington, J.; Barkov, L. M.; Vries, H. de; Gauzshtein, V. V.; Golovin, R. A.; Gramolin, A. V.; Dmitriev, V. F.; Zhilich, V. N.; Zevakov, S. A.; Kaminsky, V. V.; Lazarenko, B. A.; Mishnev, S. I.; Muchnoi, N. Yu.; Neufeld, V. V.; Rachek, I. A.; Sadykov, R. Sh.; Stibunov, V. N.; Toporkov, D. K.; Holt, R. J.; and others

    2015-05-15

    Proton electromagnetic form factors are among the most important sources of information about the internal structure of the proton. Two different methods for measuring these form factors, the method proposed by Rosenbluth and the polarization-transfer method, yield contradictory results. It is assumed that this contradiction can be removed upon taking into account the hard part of the contribution of two-photon exchange to the cross section for elastic electron-proton scattering. This contribution can measured experimentally via a precision comparison of the cross sections for the elastic scattering of positrons and electrons on protons. Such a measurement, performed at the VEPP-3 storage ring in Novosibirsk at the beam energies of 1.6 and 1.0 GeV for positron (electron) scattering angles in the ranges of θ{sub e} = 15°–25° and 55°–75° in the first case and in the range of θ{sub e} = 65°–105° in the second case is described in the present article. Preliminary results of this experiment and their comparison with theoretical predictions are described.

  18. Concerted electron-proton transfer in the optical excitation of hydrogen-bonded dyes.

    PubMed

    Westlake, Brittany C; Brennaman, M Kyle; Concepcion, Javier J; Paul, Jared J; Bettis, Stephanie E; Hampton, Shaun D; Miller, Stephen A; Lebedeva, Natalia V; Forbes, Malcolm D E; Moran, Andrew M; Meyer, Thomas J; Papanikolas, John M

    2011-05-24

    The simultaneous, concerted transfer of electrons and protons--electron-proton transfer (EPT)--is an important mechanism utilized in chemistry and biology to avoid high energy intermediates. There are many examples of thermally activated EPT in ground-state reactions and in excited states following photoexcitation and thermal relaxation. Here we report application of ultrafast excitation with absorption and Raman monitoring to detect a photochemically driven EPT process (photo-EPT). In this process, both electrons and protons are transferred during the absorption of a photon. Photo-EPT is induced by intramolecular charge-transfer (ICT) excitation of hydrogen-bonded-base adducts with either a coumarin dye or 4-nitro-4'-biphenylphenol. Femtosecond transient absorption spectral measurements following ICT excitation reveal the appearance of two spectroscopically distinct states having different dynamical signatures. One of these states corresponds to a conventional ICT excited state in which the transferring H(+) is initially associated with the proton donor. Proton transfer to the base (B) then occurs on the picosecond time scale. The other state is an ICT-EPT photoproduct. Upon excitation it forms initially in the nuclear configuration of the ground state by application of the Franck-Condon principle. However, due to the change in electronic configuration induced by the transition, excitation is accompanied by proton transfer with the protonated base formed with a highly elongated (+)H ─ B bond. Coherent Raman spectroscopy confirms the presence of a vibrational mode corresponding to the protonated base in the optically prepared state.

  19. Partonic calculation of the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer

    SciTech Connect

    Y. C. Chen; A. Afanasev; S. J. Brodsky; C. E. Carlson; Marc Vanderhaeghen

    2004-03-01

    We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer through the scattering off a parton in the proton. We relate the process on the nucleon to the generalized parton distributions which also enter in other wide angle scattering processes. We find that when taking the polarization transfer determinations of the form factors as input, adding in the 2 photon correction, does reproduce the Rosenbluth data.

  20. Chemistry as a function of the fine-structure constant and the electron-proton mass ratio

    SciTech Connect

    King, Rollin A.; Siddiqi, Ali; Allen, Wesley D.; Schaefer, Henry F. III

    2010-04-15

    In standard computations in theoretical quantum chemistry the accepted values of the fundamental physical constants are assumed. Alternatively, the tools of computational quantum chemistry can be used to investigate hypothetical chemistry that would result from different values of these constants, given the same physical laws. In this work, the dependence of a variety of basic chemical quantities on the values of the fine-structure constant and the electron-proton mass ratio is explored. In chemistry, the accepted values of both constants may be considered small, in the sense that their increase must be substantial to seriously impact bond energies. It is found that if the fine-structure constant were larger, covalent bonds between light atoms would be weaker, and the dipole moment and hydrogen-bonding ability of water would be reduced. Conversely, an increase in the value of the electron-proton mass ratio increases dissociation energies in molecules such as H{sub 2}, O{sub 2}, and CO{sub 2}. Specifically, a sevenfold increase in the fine-structure constant decreases the strength of the O-H bond in the water molecule by 7 kcal mol{sup -1} while reducing its dipole moment by at least 10%, whereas a 100-fold increase in the electron-proton mass ratio increases the same bond energy by 11 kcal mol{sup -1}.

  1. Concerted electron-proton transfer in the optical excitation of hydrogen-bonded dyes

    SciTech Connect

    Westlake, Brittany C.; Brennaman, Kyle M.; Concepcion, Javier J.; Paul, Jared J.; Bettis, Stephanie E.; Hampton, Shaun D.; Miller, Stephen A.; Lebedeva, Natalia V.; Forbes, Malcolm D. E.; Moran, Andrew M.; Meyer, Thomas J.; Papanikolas, John M.

    2011-05-24

    The simultaneous, concerted transfer of electrons and protons—electron-proton transfer (EPT)—is an important mechanism utilized in chemistry and biology to avoid high energy intermediates. There are many examples of thermally activated EPT in ground-state reactions and in excited states following photoexcitation and thermal relaxation. Here we report application of ultrafast excitation with absorption and Raman monitoring to detect a photochemically driven EPT process (photo-EPT). In this process, both electrons and protons are transferred during the absorption of a photon. Photo-EPT is induced by intramolecular charge-transfer (ICT) excitation of hydrogen-bonded-base adducts with either a coumarin dye or 4-nitro-4'-biphenylphenol. Femtosecond transient absorption spectral measurements following ICT excitation reveal the appearance of two spectroscopically distinct states having different dynamical signatures. One of these states corresponds to a conventional ICT excited state in which the transferring H⁺ is initially associated with the proton donor. Proton transfer to the base (B) then occurs on the picosecond time scale. The other state is an ICT-EPT photoproduct. Upon excitation it forms initially in the nuclear configuration of the ground state by application of the Franck–Condon principle. However, due to the change in electronic configuration induced by the transition, excitation is accompanied by proton transfer with the protonated base formed with a highly elongated ⁺H–B bond. Coherent Raman spectroscopy confirms the presence of a vibrational mode corresponding to the protonated base in the optically prepared state.

  2. The local skin dose conversion coefficients of electrons, protons and alpha particles calculated using the Geant4 code.

    PubMed

    Zhang, Bintuan; Dang, Bingrong; Wang, Zhuanzi; Wei, Wei; Li, Wenjian

    2013-10-01

    The skin tissue-equivalent slab reported in the International Commission on Radiological Protection (ICRP) Publication 116 to calculate the localised skin dose conversion coefficients (LSDCCs) was adopted into the Monte Carlo transport code Geant4. The Geant4 code was then utilised for computation of LSDCCs due to a circular parallel beam of monoenergetic electrons, protons and alpha particles <10 MeV. The computed LSDCCs for both electrons and alpha particles are found to be in good agreement with the results using the MCNPX code of ICRP 116 data. The present work thus validates the LSDCC values for both electrons and alpha particles using the Geant4 code.

  3. Two-Photon-Exchange and {gamma}Z-Exchange Corrections to Parity-Violating Elastic Electron-Proton Scattering

    SciTech Connect

    Zhou Haiqing; Kao Chungwen; Yang Shinnan

    2007-12-31

    Leading electroweak corrections play an important role in precision measurements of the strange form factors. We calculate the two-photon-exchange (TPE) and {gamma}Z-exchange corrections to the parity-violating asymmetry of the elastic electron-proton scattering in a simple hadronic model including the finite size of the proton. We find both can reach a few percent and are comparable in size with the current experimental measurements of strange-quark effects in the proton neutral weak current. The effect of {gamma}Z exchange is in general larger than that of TPE, especially at low momentum transfer Q{sup 2}{<=}1 GeV{sup 2}. Their combined effects on the values of G{sub E}{sup s}+G{sub M}{sup s} extracted in recent experiments can be as large as -40% in certain kinematics.

  4. Recovery of damage in rad-hard MOS devices during and after irradiation by electrons, protons, alphas, and gamma rays

    NASA Technical Reports Server (NTRS)

    Brucker, G. J.; Van Gunten, O.; Stassinopoulos, E. G.; Shapiro, P.; August, L. S.; Jordan, T. M.

    1983-01-01

    This paper reports on the recovery properties of rad-hard MOS devices during and after irradiation by electrons, protons, alphas, and gamma rays. The results indicated that complex recovery properties controlled the damage sensitivities of the tested parts. The results also indicated that damage sensitivities depended on dose rate, total dose, supply bias, gate bias, transistor type, radiation source, and particle energy. The complex nature of these dependencies make interpretation of LSI device performance in space (exposure to entire electron and proton spectra) difficult, if not impossible, without respective ground tests and analyses. Complete recovery of n-channel shifts was observed, in some cases within hours after irradiation, with equilibrium values of threshold voltages greater than their pre-irradiation values. This effect depended on total dose, radiation source, and gate bias during exposure. In contrast, the p-channel shifts recovered only 20 percent within 30 days after irradiation.

  5. Particle production in the Color Glass Condensate: from electron-proton DIS to proton-nucleus collisions

    NASA Astrophysics Data System (ADS)

    Lappi, T.; Mäntysaari, H.

    2014-06-01

    We study single inclusive hadron production in proton-proton and proton-nucleus collisions in the CGC framework. The parameters in the calculation are obtained by fitting electron-proton deep inelastic scattering data. The obtained dipole-proton amplitude is generalized to dipole-nucleus scattering without any additional nuclear parameters other than the Woods-Saxon distribution. We show that it is possible to use an initial condition without an anomalous dimension and still obtain a good description of the HERA inclusive cross section and LHC single particle production measurements. We argue that one must consistently use the proton transverse area as measured by a high virtuality probe in DIS also for the single inclusive cross section in proton-proton and proton-nucleus collisions, and obtain a nuclear modification factor RpA that at midrapidity approaches unity at large momenta and at all energies.

  6. Amplification of Collective Magnetic Fluctuations in Magnetized Bi-Maxwellian Plasmas for Parallel Wave Vectors. I. Electron-Proton Plasma

    NASA Astrophysics Data System (ADS)

    Vafin, S.; Schlickeiser, R.; Yoon, P. H.

    2016-09-01

    The general electromagnetic fluctuation theory is a powerful tool to analyze the magnetic fluctuation spectrum of a plasma. Recent works utilizing this theory for a magnetized non-relativistic isotropic Maxwellian electron-proton plasma have demonstrated that the equilibrium ratio of | δ B| /{B}0 can be as high as 10-12. This value results from the balance between spontaneous emission of fluctuations and their damping, and it is considerably smaller than the observed value | δ B| /{B}0 in the solar wind at 1 au, where {10}-3≲ | δ B| /{B}0≲ {10}-1. In the present manuscript, we consider an anisotropic bi-Maxwellian distribution function to investigate the effect of plasma instabilities on the magnetic field fluctuations. We demonstrate that these instabilities strongly amplify the magnetic field fluctuations and provide a sufficient mechanism to explain the observed value of | δ B| /{B}0 in the solar wind at 1 au.

  7. Contribution of two-boson exchange with {delta}(1232) excitation to parity-violating elastic electron-proton scattering

    SciTech Connect

    Nagata, Keitaro; Kao, C. W.; Zhou Haiqing; Yang Shinnan

    2009-06-15

    We study the leading electroweak corrections in the precision measurement of the strange form factors. Specifically, we calculate the two-boson exchange (TBE), two-photon exchange (TPE) plus {gamma}Z exchange ({gamma}ZE), and corrections with {delta}(1232) excitation to the parity-violating asymmetry of the elastic electron-proton scattering. The interplay between nucleon and {delta} contributions is found to depend strongly on the kinematics, as {delta}{sub {delta}} begins as negligible at backward angles but becomes very large and negative and dominant at forward angles, while {delta}{sub N} always stays positive and decreases monotonically with increasing {epsilon}. The total TBE corrections to the extracted values of G{sub E}{sup s}+{beta}G{sub M}{sup s} in recent experiments of HAPPEX and G0 are, depending on kinematics, found to be large and range between 13% and -75%, but are found to be small in the case of A4 experiments.

  8. Current Theoretical Challenges in Proton-Coupled Electron Transfer: Electron-Proton Nonadiabaticity, Proton Relays, and Ultrafast Dynamics

    SciTech Connect

    Hammes-Schiffer, Sharon

    2011-06-16

    Proton-coupled electron transfer (PCET) reactions play an important role in a wide range of biological and chemical processes. The motions of the electrons, transferring protons, solute nuclei, and solvent nuclei occur on a wide range of timescales and are often strongly coupled. As a result, the theoretical description of these processes requires a combination of quantum and classical methods. This perspective discusses three of the current theoretical challenges in the field of PCET. The first challenge is the calculation of electron-proton nonadiabatic effects, which are significant for these reactions because the hydrogen tunneling is often faster than the electronic transition. The second challenge is the modeling of electron transfer coupled to proton transport along hydrogen-bonded networks. The third challenge is the simulation of the ultrafast dynamics of nonequilibrium photoinduced PCET reactions in solution. Insights provided by theoretical studies may assist in the design of more effective catalysts for energy conversion processes. The proton relay portion of this review is based upon work supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.

  9. Current Theoretical Challenges in Proton-Coupled Electron Transfer: Electron Proton Nonadiabaticity, Proton Relays, and Ultrafast Dynamics

    SciTech Connect

    Hammes-Schiffer, Sharon

    2011-06-16

    Proton-coupled electron transfer (PCET) reactions play an important role in a wide range of biological and chemical processes. The motions of the electrons, transferring protons, solute nuclei, and solvent nuclei occur on a wide range of time scales and are often strongly coupled. As a result, the theoretical description of these processes requires a combination of quantum and classical methods. This Perspective discusses three of the current theoretical challenges in the field of PCET. The first challenge is the calculation of electron proton nonadiabatic effects, which are significant for these reactions because the hydrogen tunneling is often faster than the electronic transition. The second challenge is the modeling of electron transfer coupled to proton transport along hydrogen-bonded networks. The third challenge is the simulation of the ultrafast dynamics of nonequilibrium photoinduced PCET reactions in solution. Insights provided by theoretical studies may assist in the design of more effective catalysts for energy conversion processes. The proton relay portion of this review is based upon work supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.

  10. Dependence of Vibronic Coupling on Molecular Geometry and Environment: Bridging Hydrogen Atom Transfer and Electron-Proton Transfer.

    PubMed

    Harshan, Aparna Karippara; Yu, Tao; Soudackov, Alexander V; Hammes-Schiffer, Sharon

    2015-10-28

    The rate constants for typical concerted proton-coupled electron transfer (PCET) reactions depend on the vibronic coupling between the diabatic reactant and product states. The form of the vibronic coupling is different for electronically adiabatic and nonadiabatic reactions, which are associated with hydrogen atom transfer (HAT) and electron-proton transfer (EPT) mechanisms, respectively. Most PCET rate constant expressions rely on the Condon approximation, which assumes that the vibronic coupling is independent of the nuclear coordinates of the solute and the solvent or protein. Herein we test the Condon approximation for PCET vibronic couplings. The dependence of the vibronic coupling on molecular geometry is investigated for an open and a stacked transition state geometry of the phenoxyl-phenol self-exchange reaction. The calculations indicate that the open geometry is electronically nonadiabatic, corresponding to an EPT mechanism that involves significant electronic charge redistribution, while the stacked geometry is predominantly electronically adiabatic, corresponding primarily to an HAT mechanism. Consequently, a single molecular system can exhibit both HAT and EPT character. The dependence of the vibronic coupling on the solvent or protein configuration is examined for the soybean lipoxygenase enzyme. The calculations indicate that this PCET reaction is electronically nonadiabatic with a vibronic coupling that does not depend significantly on the protein environment. Thus, the Condon approximation is shown to be valid for the solvent and protein nuclear coordinates but invalid for the solute nuclear coordinates in certain PCET systems. These results have significant implications for the calculation of rate constants, as well as mechanistic interpretations, of PCET reactions.

  11. Alternative wavefunction ansatz for including explicit electron-proton correlation in the nuclear-electronic orbital approach

    NASA Astrophysics Data System (ADS)

    Ko, Chaehyuk; Pak, Michael V.; Swalina, Chet; Hammes-Schiffer, Sharon

    2011-08-01

    The nuclear-electronic orbital (NEO) approach treats specified nuclei quantum mechanically on the same level as the electrons with molecular orbital techniques. The explicitly correlated Hartree-Fock (NEO-XCHF) approach was developed to incorporate electron-nucleus dynamical correlation directly into the variational optimization of the nuclear-electronic wavefunction. In the original version of this approach, the Hartree-Fock wavefunction is multiplied by (1 + hat G), where hat G is a geminal operator expressed as a sum of Gaussian type geminal functions that depend on the electron-proton distance. Herein, a new wavefunction ansatz is proposed to avoid the computation of five- and six-particle integrals and to simplify the computation of the lower dimensional integrals involving the geminal functions. In the new ansatz, denoted NEO-XCHF2, the Hartree-Fock wavefunction is multiplied by √ {1 + hat G} rather than (1 + hat G). Although the NEO-XCHF2 ansatz eliminates the integrals that are quadratic in the geminal functions, it introduces terms in the kinetic energy integrals with no known analytical solution. A truncated expansion scheme is devised to approximate these problematic terms. An alternative hybrid approach, in which the kinetic energy terms are calculated with the original NEO-XCHF ansatz and the potential energy terms are calculated with the NEO-XCHF2 ansatz, is also implemented. Applications to a series of model systems with up to four electrons provide validation for the NEO-XCHF2 approach and the treatments of the kinetic energy terms.

  12. Empirical parametrization of the two-photon-exchange effect contributions to the electron-proton elastic scattering cross section

    SciTech Connect

    Qattan, I. A.; Alsaad, A.

    2011-05-15

    The most recent electron-proton elastic scattering data were re-analyzed using an empirical parametrization of the two-photon-exchange (TPE) effect contributions to {sigma}{sub R}. The TPE effect contribution F(Q{sup 2},{epsilon}) was double Taylor series expanded as a polynomial of order n keeping only terms linear in {epsilon} to account for the experimentally observed and verified linearity of the Rosenbluth plots. We fix the ratio R=G{sub Ep}/G{sub Mp} to be that obtained from a fit to the recoil-polarization data and parametrize {sigma}{sub R} first by a three-parameter formula (fit I) and then by a two-parameter formula (fit III). In contrast to previous analyses, the fit parameter G{sub Mp}{sup 2} as obtained from these fits is either smaller or equal to the values obtained from our conventional Rosenbluth fit (fit II) but never larger. The ratio g(Q{sup 2})/G{sub Mp}{sup 2} which represents the ratio of the TPE and one-photon-exchange (OPE) effect contributions to the intercept of {sigma}{sub R} is large and it ranges 3%-88%. The ratio R{sub 1{gamma}x2{gamma}={tau}}f(Q{sup 2})/G{sub Ep}{sup 2} which represents the ratio of the TPE and OPE effect contributions to the slope of {sigma}{sub R} is also large, reaching a value of 12.0-14.4 at Q{sup 2}= 5.25 (GeV/c){sup 2}. The ratio R{sub 1{gamma}x2{gamma}} as obtained from fits I and III is consistent, within error, with those obtained from previous analyses. Our formulas seem to explain the linearity of {sigma}{sub R}. Moreover, our analysis shows that the extracted G{sub Ep}{sup 2} and G{sub Mp}{sup 2} using the conventional Rosenbluth separation method can in fact be broken into the usual OPE and TPE contributions. Therefore, {sigma}{sub R} can in fact be derived under weaker conditions than those imposed by the Born approximation. Our results show that the TPE amplitudes, g(Q{sup 2})/G{sub Mp}{sup 2} and f(Q{sup 2})/G{sub Mp}{sup 2}, are sizable and grow with Q{sup 2} value up to Q{sup 2}{approx}6 (Ge

  13. Beam normal single spin asymmetry in forward angle inelastic electron-proton scattering using the q-weak apparatus

    NASA Astrophysics Data System (ADS)

    Nuruzzaman, FNU

    The Q-weak experiment in Hall-C at the Thomas Jefferson National Accelerator Facility has made the first direct measurement of the weak charge of the proton through the precision measurement of the parity-violating asymmetry in elastic electron-proton scattering at low momentum transfer. There is also a parity conserving Beam Normal Single Spin Asymmetry or transverse asymmetry (Bn) on H2 with a sin(phi)-like dependence due to two-photon exchange. If the size of elastic Bn is a few ppm, then a few percent residual transverse polarization in the beam, combined with small broken azimuthal symmetries in the detector, would require a few ppb correction to the Q-weak data. As part of a program of Bn background studies, we made the first measurement of Bn in the N-to-Delta(1232) transition using the Q-weak apparatus. The final transverse asymmetry, corrected for backgrounds and beam polarization, was found to be Bn = 42.82 +- 2.45 (stat) +- 16.07 (sys) ppm at beam energy Ebeam = 1.155 GeV, scattering angle theta = 8.3 degrees, and missing mass W = 1.2 GeV. Bn from electron-nucleon scattering is a unique tool to study the gamma*DeltaDelta form factors, and this measurement will help to improve the theoretical models on beam normal single spin asymmetry and thereby our understanding of the doubly virtual Compton scattering process. To help correct false asymmetries from beam noise, a beam modulation system was implemented to induce small position, angle, and energy changes at the target to characterize detector response to the beam jitter. Two air-core dipoles separated by ˜10 m were pulsed at a time to produce position and angle changes at the target, for virtually any tune of the beamline. The beam energy was modulated using an SRF cavity. The hardware and associated control instrumentation will be described in this dissertation. Preliminary detector sensitivities were extracted which helped to reduce the width of the measured asymmetry. The beam modulation system has

  14. Beam Normal Single Spin Asymmetry in Forward Angle Inelastic Electron-Proton Scattering using the Q-Weak Apparatus

    SciTech Connect

    ., Nuruzzaman

    2014-12-01

    The Q-weak experiment in Hall-C at the Thomas Jefferson National Accelerator Facility has made the first direct measurement of the weak charge of the proton through the precision measurement of the parity-violating asymmetry in elastic electron-proton scattering at low momentum transfer. There is also a parity conserving Beam Normal Single Spin Asymmetry or transverse asymmetry (B_n) on H_2 with a sin(phi)-like dependence due to two-photon exchange. If the size of elastic B_n is a few ppm, then a few percent residual transverse polarization in the beam, combined with small broken azimuthal symmetries in the detector, would require a few ppb correction to the Q-weak data. As part of a program of B_n background studies, we made the first measurement of B_n in the N-to-Delta(1232) transition using the Q-weak apparatus. The final transverse asymmetry, corrected for backgrounds and beam polarization, was found to be B_n = 42.82 ± 2.45 (stat) ± 16.07 (sys) ppm at beam energy E_beam = 1.155 GeV, scattering angle theta = 8.3 deg, and missing mass W = 1.2 GeV. B_n from electron-nucleon scattering is a unique tool to study the gamma^* Delta Delta form factors, and this measurement will help to improve the theoretical models on beam normal single spin asymmetry and thereby our understanding of the doubly virtual Compton scattering process. To help correct false asymmetries from beam noise, a beam modulation system was implemented to induce small position, angle, and energy changes at the target to characterize detector response to the beam jitter. Two air-core dipoles separated by ~10 m were pulsed at a time to produce position and angle changes at the target, for virtually any tune of the beamline. The beam energy was modulated using an SRF cavity. The hardware and associated control instrumentation will be described in this dissertation. Preliminary detector sensitivities were extracted which helped to reduce the width of the measured asymmetry. The beam modulation system

  15. Investigation of the effective atomic numbers of dosimetric materials for electrons, protons and alpha particles using a direct method in the energy region 10 keV-1 GeV: a comparative study.

    PubMed

    Kurudirek, Murat; Aksakal, Oğuz; Akkuş, Tuba

    2015-11-01

    A direct method has been used for the first time, to compute effective atomic numbers (Z eff) of water, air, human tissues, and some organic and inorganic compounds, for total electron proton and alpha particle interaction in the energy region 10 keV-1 GeV. The obtained values for Z eff were then compared to those obtained using an interpolation procedure. In general, good agreement has been observed for electrons, and the difference (%) in Z eff between the results of the direct and the interpolation method was found to be <10 % for all materials, in the energy range from 10 keV to 1 MeV. More specifically, results of the two methods were found to agree well (Dif. <10 %) for air, calcium fluoride, kapton polyimide film, paraffin wax and plastic scintillator in the entire energy region with respect to the total electron interaction. On the other hand, values for Z eff calculated using both methods for protons and alpha particles generally agree with each other in the high-energy region above 10 MeV.

  16. Measurements of electron-proton elastic cross sections for 0.4 < Q{sup 2} < 5.5 (GeV/c){sup 2}

    SciTech Connect

    M.E. Christy; Abdellah Ahmidouch; Christopher Armstrong; John Arrington; Razmik Asaturyan; Steven Avery; O. Baker; Douglas Beck; Henk Blok; C.W.Bochna; Werner Boeglin; Peter Bosted; Maurice Bouwhuis; Herbert Breuer; D.S.Brown; Antje Bruell; Roger Carlini; Nicholas Chant; Anthony Cochran; Leon Cole; Samuel Danagoulian; Donal Day; James Dunne; Dipangkar Dutta; Rolf Ent; Howard Fenker; B.Fox; Liping Gan; Haiyan Gao; Kenneth Garrow; David Gaskell; Ashot Gasparian; Don Geesaman; Paul Gueye; Mark Harvey; Roy Holt; Xiaodong Jiang; Cynthia Keppel; Edward Kinney; Yongguang Liang; Wolfgang Lorenzon; Allison Lung; Pete Markowitz; J.W.Martin; Kevin McIlhany; Daniella Mckee; David Meekins; M.A.Miller; Richard Milner; Joseph Mitchell; Hamlet Mkrtchyan; Robert Mueller; Alan Nathan; Gabriel Niculescu; Maria-Ioana Niculescu; Thomas O'neill; Vassilios Papavassiliou; Stephen Pate; Buz Piercey; David Potterveld; Ronald Ransome; Joerg Reinhold; E.Rollinde; Philip Roos; Adam Sarty; Reyad Sawafta; Elaine Schulte; Edwin Segbefia; C.Smith; Stepan Stepanyan; Steffen Strauch; Vardan Tadevosyan; Liguang Tang; Raphael Tieulent; Alicia Uzzle; William Vulcan; Stephen Wood; Feng Xiong; Lulin Yuan; Markus Zeier; Benedikt Zihlmann; Vitaliy Ziskin

    2004-01-01

    We report on precision measurements of the elastic cross section for electron-proton scattering performed in Hall C at Jefferson Lab. The measurements were made at 28 unique kinematic settings covering a range in momentum transfer of 0.4 < Q{sup 2} < 5.5 (/rm GeV/c){sup 2}. These measurements represent a significant contribution to the world's cross section data set in the Q{sup 2} range where a large discrepancy currently exists between the ratio of electric to magnetic proton form factors extracted from previous cross section measurements and that recently measured via polarization transfer in Hall A at Jefferson Lab.

  17. Galactic Cosmic Ray Proton Spectra during Solar Cycle 23 and 24 - Measurement Capabilities of the Electron Proton Helium Telescope on Board SOHO

    NASA Astrophysics Data System (ADS)

    Kühl, Patrick; Klassen, Andreas; Gieseler, Jan; Dresing, Nina; Heber, Bernd

    2016-07-01

    The solar modulation of galactic cosmic rays (GCR) can be studied in detail by long term variations of the GCR energy spectrum (e.g. on the scales of a solar cycle). With almost 20 years of data, the Electron Proton Helium INstrument (EPHIN) aboard SOHO is well suited for these kind of investigations. Although the design of the instrument is optimized to measure proton and helium isotope spectra up to 50 MeV/nucleon the capability exist that allow to determine energy spectra between 250 MeV and 1.6 GeV. Therefore we developed a sophisticated inversion method to calculate such proton spectra. The method relies on a GEANT4 Monte Carlo simulation of the instrument and a simplified spacecraft model that calculates the energy response function of EPHIN for electrons, protons and heavier ions. In order to determine the energy spectra the resulting inversion problem is solved numerically. As a result we present galactic cosmic ray spectra from 1995 to 2015. For validation, the derived spectra are compared to AMS, BESS and PAMELA data. Furthermore we discuss the spectra with respect to the solar modulation.

  18. X-ray and TeV Gamma-Ray Emission from Parallel Electron-Positron or Electron-Proton Beams in BL Lac Objects

    NASA Astrophysics Data System (ADS)

    Krawczynski, Henric

    2007-04-01

    In this contribution we discuss models of the X-rays and TeV gamma-ray emission from BL Lac objects based on parallel electron-positron or electron-proton beams that form close to the central black hole owing to the strong electric fields generated by the accretion disk and possibly also by the black hole itself. Fitting the energy spectrum of the BL Lac object Mrk 501, we obtain tight constrains on the beam properties. Launching a sufficiently energetic beam requires rather strong magnetic fields close to the black hole 100-1000 G. However, the model fits imply that the magnetic field in the emission region is only 0.02 G. Thus, the particles are accelerated close to the black hole and propagate a considerable distance before instabilities trigger the dissipation of energy through synchrotron and self-Compton emission. We discuss various approaches to generate enough power to drive the jet and, at the same time, to accelerate particles to 20 TeV energies. Although the parallel beam model has its own problems, it explains some of the long-standing problems that plague models based on Fermi type particle acceleration, like the presence of a very high minimum Lorentz factor of accelerated particles. We conclude with a brief discussion of the implications of the model for the difference between the processes of jet formation in BL Lac type objects and in quasars.

  19. X-Ray and TeV Gamma-Ray Emission from Parallel Electron-Positron or Electron-Proton Beams in BL Lacertae Objects

    NASA Astrophysics Data System (ADS)

    Krawczynski, H.

    2007-04-01

    In this paper we discuss models of the X-ray and TeV γ-ray emission from BL Lac objects based on parallel electron-positron or electron-proton beams that form close to the central black hole, due to the strong electric fields generated by the accretion disk and possibly also by the black hole itself. Fitting the energy spectrum of the BL Lac object Mrk 501, we obtain tight constraints on the beam properties. Launching a sufficiently energetic beam requires rather strong magnetic fields close to the black hole (~100-1000 G). However, the model fits imply that the magnetic field in the emission region is only ~0.02 G. Thus, the particles are accelerated close to the black hole and propagate a considerable distance before instabilities trigger the dissipation of energy through synchrotron and self-Compton emission. We discuss various approaches to generate enough power to drive the jet and, at the same time, to accelerate particles to ~20 TeV energies. Although the parallel beam model has its own problems, it explains some of the long-standing problems that plague models based on Fermi-type particle acceleration, such as the presence of a very high minimum Lorentz factor of accelerated particles. We conclude with a brief discussion of the implications of the model for the difference between the processes of jet formation in BL Lac-type objects and those in quasars.

  20. Geant4 Monte Carlo simulation of energy loss and transmission and ranges for electrons, protons and ions

    NASA Astrophysics Data System (ADS)

    Ivantchenko, Vladimir

    Geant4 is a toolkit for Monte Carlo simulation of particle transport originally developed for applications in high-energy physics with the focus on experiments at the Large Hadron Collider (CERN, Geneva). The transparency and flexibility of the code has spread its use to other fields of research, e.g. radiotherapy and space science. The tool provides possibility to simulate complex geometry, transportation in electric and magnetic fields and variety of physics models of interaction of particles with media. Geant4 has been used for simulation of radiation effects for number of space missions. Recent upgrades of the toolkit released in December 2009 include new model for ion electronic stopping power based on the revised version of ICRU'73 Report increasing accuracy of simulation of ion transport. In the current work we present the status of Geant4 electromagnetic package for simulation of particle energy loss, ranges and transmission. This has a direct implication for simulation of ground testing setups at existing European facilities and for simulation of radiation effects in space. A number of improvements were introduced for electron and proton transport, followed by a thorough validation. It was the aim of the present study to validate the range against reference data from the United States National Institute of Standards and Technologies (NIST) ESTAR, PSTAR and ASTAR databases. We compared Geant4 and NIST ranges of electrons using different Geant4 models. The best agreement was found for Penelope, except at very low energies in heavy materials, where the Standard package gave better results. Geant4 proton ranges in water agreed with NIST within 1 The validation of the new ion model is performed against recent data on Bragg peak position in water. The data from transmission of carbon ions via various absorbers following Bragg peak in water demonstrate that the new Geant4 model significantly improves precision of ion range. The absolute accuracy of ion range

  1. SU-E-J-09: A Monte Carlo Analysis of the Relationship Between Cherenkov Light Emission and Dose for Electrons, Protons, and X-Ray Photons

    SciTech Connect

    Glaser, A; Zhang, R; Gladstone, D; Pogue, B

    2014-06-01

    Purpose: A number of recent studies have proposed that light emitted by the Cherenkov effect may be used for a number of radiation therapy dosimetry applications. Here we investigate the fundamental nature and accuracy of the technique for the first time by using a theoretical and Monte Carlo based analysis. Methods: Using the GEANT4 architecture for medically-oriented simulations (GAMOS) and BEAMnrc for phase space file generation, the light yield, material variability, field size and energy dependence, and overall agreement between the Cherenkov light emission and dose deposition for electron, proton, and flattened, unflattened, and parallel opposed x-ray photon beams was explored. Results: Due to the exponential attenuation of x-ray photons, Cherenkov light emission and dose deposition were identical for monoenergetic pencil beams. However, polyenergetic beams exhibited errors with depth due to beam hardening, with the error being inversely related to beam energy. For finite field sizes, the error with depth was inversely proportional to field size, and lateral errors in the umbra were greater for larger field sizes. For opposed beams, the technique was most accurate due to an averaging out of beam hardening in a single beam. The technique was found to be not suitable for measuring electron beams, except for relative dosimetry of a plane at a single depth. Due to a lack of light emission, the technique was found to be unsuitable for proton beams. Conclusions: The results from this exploratory study suggest that optical dosimetry by the Cherenkov effect may be most applicable to near monoenergetic x-ray photon beams (e.g. Co-60), dynamic IMRT and VMAT plans, as well as narrow beams used for SRT and SRS. For electron beams, the technique would be best suited for superficial dosimetry, and for protons the technique is not applicable due to a lack of light emission. NIH R01CA109558 and R21EB017559.

  2. Interaction-Region Design Options for a Linac-Ring LHeC

    SciTech Connect

    Zimmermann, Frank; Bettoni, Simona; Bruning, Oliver; Holzer, Bernhard; Russenschuck, Stephan; Schulte, Daniel; Tomas, Rogelio; Aksakal, Husnu; Appleby, Robert; Chattopadhyay, Swapan; Korostelev, Maxim; Ciftci, Abbas; Ciftci, Rena; Zengin, Kahraman; Dainton, John; Klein, Max; Eroglu, Emre; Tapan, Ilhan; Kostka, Peter; Litvinenko, Vladimir; Paoloni, Eugenio; /INFN, Pisa /INFN, Bologna /DESY /SLAC

    2012-06-21

    The interaction-region design for a linac-ring electron-proton collider based on the LHC ('LR-LHeC') poses numerous challenges related to collision scheme, synchrotron radiation, aperture, magnet technology, and optics. We report a first assessment and various options.

  3. Annual Cosmic Ray Spectra from 250 MeV up to 1.6 GeV from 1995 - 2014 Measured with the Electron Proton Helium Instrument onboard SOHO

    NASA Astrophysics Data System (ADS)

    Kühl, P.; Gómez-Herrero, R.; Heber, B.

    2016-03-01

    The solar modulation of galactic cosmic rays (GCR) can be studied in detail by examining long-term variations of the GCR energy spectrum ( e.g. on the scales of a solar cycle). With almost 20 years of data, the Electron Proton Helium INstrument (EPHIN) onboard the SOlar and Heliospheric Observatory (SOHO) is well suited for this kind of investigation. Although the design of the instrument is optimised to measure proton and helium isotope spectra up to 50 MeV nucleon^{-1}, the capability exists to determine proton energy spectra from 250 MeV up to above 1.6 GeV. Therefore we developed a sophisticated inversion method to calculate such proton spectra. The method relies on a GEANT4 Monte Carlo simulation of the instrument and a simplified spacecraft model that calculates the energy-response function of EPHIN for electrons, protons, and heavier ions. For validation purposes, proton spectra based on this method are compared to various balloon missions and space instrumentation. As a result we present annual galactic cosmic-ray spectra from 1995 to 2014.

  4. Possibility of measuring Adler angles in charged current single pion neutrino-nucleus interactions

    NASA Astrophysics Data System (ADS)

    Sánchez, F.

    2016-05-01

    Uncertainties in modeling neutrino-nucleus interactions are a major contribution to systematic errors in long-baseline neutrino oscillation experiments. Accurate modeling of neutrino interactions requires additional experimental observables such as the Adler angles which carry information about the polarization of the Δ resonance and the interference with nonresonant single pion production. The Adler angles were measured with limited statistics in bubble chamber neutrino experiments as well as in electron-proton scattering experiments. We discuss the viability of measuring these angles in neutrino interactions with nuclei.

  5. Analysis of Geophysical Data Bases and Models for Spacecraft Interactions.

    DTIC Science & Technology

    1986-10-31

    electrons, protons, ions (major species), and measured dose. - Evaluation of magnetic field models (Delta B Model). - Quasi- static Data Bases, Analysis ...AIB4 889 ANALYSIS OF GEOPHYSICRL DATA BASES AND MODELS FOR 1/3 SPACECRAFT INTERACTIONS(U) RADEX INC CARLISLE MA J N BAS ET AL 31 OCT 86 AFGL-TR-86...1114 11116 MICROCOPY RESOLUTION TEST CHART NATI()NAL BUREAU flE SIANDARD % 43 A oJ P=I -- % AFGL-TR-86-0221 0 00 ANALYSIS OF GEOPHYSICAL DATA BASES

  6. Detection system for electron-proton coincidences in neutron decay

    NASA Astrophysics Data System (ADS)

    Broussard, Leah; Nab Collaboration; Ucnb Collaboration; Tristan Collaboration

    2017-01-01

    By precisely measuring angular correlations in neutron decay, we can perform precise tests of the Standard Model and search for new physics beyond the Standard Model. The upcoming Nab and UCNB experiments will measure the correlations a and b, and B, respectively, in neutron decay. The collaborations have jointly developed a prototype detection system based on thick, large area silicon detectors which meets experimental requirements of 3 keV FWHM energy resolution, rise times of 50 ns, and energy thresholds below 10 keV. We will present results of characterization of the prototype and an update on the development of the final, fully instrumented detection system. We also present a study of very thin deadlayer silicon drift detectors in development by the TRISTAN collaboration, and their possible applicability to neutron decay correlation experiments.

  7. Parity Violation in Forward Angle Elastic Electron-Proton Scattering

    SciTech Connect

    Miller, IV, Grady Wilson

    2001-01-01

    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton at Jefferson Laboratory. The kinematic point (θlab = 12.3 deg. and (Q2) = 0.48 (GeV/c)2) is chosen to provide sensitivity to the strange electric form factor GsE. A 3.36 GeV beam of longitudinally polarized electrons was scattered from protons in a liquid hydrogen target. The scattered flux was detected by a pair of spectrometers which focussed the elastically-scattered electrons onto total-absorption detectors. The detector signals were integrated and digitized by a custom data acquisition system. A feedback system reduced systematic errors by controlling helicity-correlated beam intensity differences at the sub-ppm (part per million) level. The experimental result, A = 14.5 +/- 2.0 (stat) ± 1.1 (syst) ppm, is consistent with the electroweak Standard Model with no additional contributions from strange quarks. In particular, the measurement implies GSE + 0.39 GsM = 0.023 ± 0.040 ± 0.026 (ζGnE), where the last uncertainty is due to the estimated uncertainty in the neutron electric form factor GnE . This result represents the first experimental constraint of the strange electric form factor.

  8. Design of the large hadron electron collider interaction region

    NASA Astrophysics Data System (ADS)

    Cruz-Alaniz, E.; Newton, D.; Tomás, R.; Korostelev, M.

    2015-11-01

    The large hadron electron collider (LHeC) is a proposed upgrade of the Large Hadron Collider (LHC) within the high luminosity LHC (HL-LHC) project, to provide electron-nucleon collisions and explore a new regime of energy and luminosity for deep inelastic scattering. The design of an interaction region for any collider is always a challenging task given that the beams are brought into crossing with the smallest beam sizes in a region where there are tight detector constraints. In this case integrating the LHeC into the existing HL-LHC lattice, to allow simultaneous proton-proton and electron-proton collisions, increases the difficulty of the task. A nominal design was presented in the the LHeC conceptual design report in 2012 featuring an optical configuration that focuses one of the proton beams of the LHC to β*=10 cm in the LHeC interaction point to reach the desired luminosity of L =1033 cm-2 s-1 . This value is achieved with the aid of a new inner triplet of quadrupoles at a distance L*=10 m from the interaction point. However the chromatic beta beating was found intolerable regarding machine protection issues. An advanced chromatic correction scheme was required. This paper explores the feasibility of the extension of a novel optical technique called the achromatic telescopic squeezing scheme and the flexibility of the interaction region design, in order to find the optimal solution that would produce the highest luminosity while controlling the chromaticity, minimizing the synchrotron radiation power and maintaining the dynamic aperture required for stability.

  9. Monoenergetic beams of relativistic electrons from intense laser-plasma interactions.

    PubMed

    Mangles, S P D; Murphy, C D; Najmudin, Z; Thomas, A G R; Collier, J L; Dangor, A E; Divall, E J; Foster, P S; Gallacher, J G; Hooker, C J; Jaroszynski, D A; Langley, A J; Mori, W B; Norreys, P A; Tsung, F S; Viskup, R; Walton, B R; Krushelnick, K

    2004-09-30

    High-power lasers that fit into a university-scale laboratory can now reach focused intensities of more than 10(19) W cm(-2) at high repetition rates. Such lasers are capable of producing beams of energetic electrons, protons and gamma-rays. Relativistic electrons are generated through the breaking of large-amplitude relativistic plasma waves created in the wake of the laser pulse as it propagates through a plasma, or through a direct interaction between the laser field and the electrons in the plasma. However, the electron beams produced from previous laser-plasma experiments have a large energy spread, limiting their use for potential applications. Here we report high-resolution energy measurements of the electron beams produced from intense laser-plasma interactions, showing that--under particular plasma conditions--it is possible to generate beams of relativistic electrons with low divergence and a small energy spread (less than three per cent). The monoenergetic features were observed in the electron energy spectrum for plasma densities just above a threshold required for breaking of the plasma wave. These features were observed consistently in the electron spectrum, although the energy of the beam was observed to vary from shot to shot. If the issue of energy reproducibility can be addressed, it should be possible to generate ultrashort monoenergetic electron bunches of tunable energy, holding great promise for the future development of 'table-top' particle accelerators.

  10. Interacting faults

    NASA Astrophysics Data System (ADS)

    Peacock, D. C. P.; Nixon, C. W.; Rotevatn, A.; Sanderson, D. J.; Zuluaga, L. F.

    2017-04-01

    The way that faults interact with each other controls fault geometries, displacements and strains. Faults rarely occur individually but as sets or networks, with the arrangement of these faults producing a variety of different fault interactions. Fault interactions are characterised in terms of the following: 1) Geometry - the spatial arrangement of the faults. Interacting faults may or may not be geometrically linked (i.e. physically connected), when fault planes share an intersection line. 2) Kinematics - the displacement distributions of the interacting faults and whether the displacement directions are parallel, perpendicular or oblique to the intersection line. Interacting faults may or may not be kinematically linked, where the displacements, stresses and strains of one fault influences those of the other. 3) Displacement and strain in the interaction zone - whether the faults have the same or opposite displacement directions, and if extension or contraction dominates in the acute bisector between the faults. 4) Chronology - the relative ages of the faults. This characterisation scheme is used to suggest a classification for interacting faults. Different types of interaction are illustrated using metre-scale faults from the Mesozoic rocks of Somerset and examples from the literature.

  11. Imagined Interactions

    ERIC Educational Resources Information Center

    Honeycutt, James M.

    2010-01-01

    Social scientists have been studying imagined interactions since the mid-1980s and have measured numerous physiological correlates (Honeycutt, 2010). In this commentary I assess the research reported in Crisp and Turner (May-June 2009) and highlight the underlying mechanisms of imagined interactions that have empirically been laid out across…

  12. Interacting parasites

    USGS Publications Warehouse

    Lafferty, Kevin D.

    2010-01-01

    Parasitism is the most popular life-style on Earth, and many vertebrates host more than one kind of parasite at a time. A common assumption is that parasite species rarely interact, because they often exploit different tissues in a host, and this use of discrete resources limits competition (1). On page 243 of this issue, however, Telfer et al. (2) provide a convincing case of a highly interactive parasite community in voles, and show how infection with one parasite can affect susceptibility to others. If some human parasites are equally interactive, our current, disease-by-disease approach to modeling and treating infectious diseases is inadequate (3).

  13. Strong Interaction

    SciTech Connect

    Karsch, F.; Vogelsang, V.

    2009-09-29

    We will give here an overview of our theory of the strong interactions, Quantum Chromo Dynamics (QCD) and its properties. We will also briefly review the history of the study of the strong interactions, and the discoveries that ultimately led to the formulation of QCD. The strong force is one of the four known fundamental forces in nature, the others being the electromagnetic, the weak and the gravitational force. The strong force, usually referred to by scientists as the 'strong interaction', is relevant at the subatomic level, where it is responsible for the binding of protons and neutrons to atomic nuclei. To do this, it must overcome the electric repulsion between the protons in an atomic nucleus and be the most powerful force over distances of a few fm (1fm=1 femtometer=1 fermi=10{sup -15}m), the typical size of a nucleus. This property gave the strong force its name.

  14. Weak Interactions

    DOE R&D Accomplishments Database

    Lee, T. D.

    1957-06-01

    Experimental results on the non-conservation of parity and charge conservation in weak interactions are reviewed. The two-component theory of the neutrino is discussed. Lepton reactions are examined under the assumption of the law of conservation of leptons and that the neutrino is described by a two- component theory. From the results of this examination, the universal Fermi interactions are analyzed. Although reactions involving the neutrino can be described, the same is not true of reactions which do not involve the lepton, as the discussion of the decay of K mesons and hyperons shows. The question of the invariance of time reversal is next examined. (J.S.R.)

  15. Radiation damage effects by electrons, protons, and neutrons in Si/Li/ detectors.

    NASA Technical Reports Server (NTRS)

    Liu, Y. M.; Coleman, J. A.

    1972-01-01

    The degradation in performance of lithium-compensated silicon nuclear particle detectors induced by irradiation at room temperature with 0.6-MeV and 1.5-MeV electrons, 1.9-MeV protons, and fast neutrons from a plutonium-beryllium source has been investigated. With increasing fluence, the irradiations produced an increase of detector leakage current, noise, capacitance, and a degradation in the performance of the detector as a charged-particle energy spectrometer. Following the irradiations, annealing effects were observed when the detectors were reverse-biased at their recommended operating voltages. Upon removal of bias, a continuous degradation of detector performance characteristics occurred. Detectors which had been damaged by electrons and protons exhibited a stabilization in their characteristics within two weeks after irradiation, whereas detectors damaged by neutrons had a continuous degradation of performance over a period of several months.

  16. Two-Photon Exchange Effects in Elastic Electron-Proton Scattering

    SciTech Connect

    Johnson, Myriam James

    2013-08-01

    Two methods, Rosenbluth separation and polarization transfer, can be used to extract the proton form factor ratio μp GEp/GMp, but they do not yield the same results. It is thought that the disagreement is due to two photon exchange corrections to the differential cross sections. High precision proton Rosenbluth extractions were carried out at 102 kinematics points spanning 16 values of momentum transfer Q2, from 0.40 to 5.76 GeV2. Reduced cross sections were found to 1.1% or better for Q2 less than 3 GeV2 increasing to 4% at 5.76 GeV2 The form factor ratios were determined to 1:5-3% for Q2 < 1.5 GeV2, increasing to 9% by 3 GeV2 and rapidly above. Our data agrees with prior Rosenbluth, improving upon it the 1.0 - 2.0 GeV2 range to conclusively show a separation from polarization transfer where it had not been certain before. In addition, reduced cross sections at each Q2 were tested for nonlinearity in the angular variable. Such a departure from linearity would be a signature of two photon exchange effects, and prior data had not been sufficiently precise to show nonzero curvature. Our data begins to hint at negative curvature but does not yet show a significant departure from zero.

  17. Probing anomalous couplings using di-Higgs production in electron-proton collisions

    NASA Astrophysics Data System (ADS)

    Kumar, Mukesh; Ruan, Xifeng; Islam, Rashidul; Cornell, Alan S.; Klein, Max; Klein, Uta; Mellado, Bruce

    2017-01-01

    A proposed high energy Future Circular Hadron-Electron Collider would provide sufficient energy in a clean environment to probe di-Higgs production. Using this channel we show that the azimuthal angle correlation between the missing transverse energy and the forward jet is a very good probe for the non-standard hhh and hhWW couplings. We give the exclusion limits on these couplings as a function of integrated luminosity at a 95% C.L. using the fiducial cross sections. With appropriate error fitting methodology we find that the Higgs boson self coupling could be measured to be ghhh(1) = 1.00-0.17(0.12)+0.24(0.14) of its expected Standard Model value at √{ s} = 3.5 (5.0) TeV for an ultimate 10 ab-1 of integrated luminosity.

  18. The damage equivalence of electrons, protons, alphas and gamma rays in rad-hard MOS devices

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, E. G.; Van Gunten, O.; Brucker, G. J.; Knudson, A. R.; Jordan, T. M.

    1983-01-01

    This paper reports on a study of damage equivalence in rad-hard MOS devices with 100,000 rads (SiO2) capability. Damage sensitivities for electrons of 1, 2, 3, 5, and 7 MeV, protons of 1, 3, 7, 22, and 40 MeV, 3.4-MeV alphas, and Co-60 gammas were measured and compared. Results indicated that qualitatively the same charge recombination effects occurred in hard oxide devices for doses of 100,000 rads (SiO2) as in soft oxide parts for doses of 1 to 4 krads (SiO2). Consequently, damage equivalency or non-equivalency depended on radiation type and energy. However, recovery effects, both during and after irradiation, controlled relative damage sensitivity and its dependency on total dose, dose rate, supply bias, gate bias, radiation type, and energy. Correction factors can be derived from these data or from similar tests of other hard oxide type, so as to properly evaluate the combined effects of the total space environment.

  19. Transverse Beam Spin Asymmetries in Forward-Angle Elastic Electron-Proton Scattering

    SciTech Connect

    Armstrong, D. S.; Averett, T.; Bailey, S. L.; Finn, J. M.; Griffioen, K. A.; Moffit, B.; Phillips, S. K.; Secrest, J.; Sulkosky, V.; Arvieux, J.; Bimbot, L.; Guler, H.; Lenoble, J.; Marchand, D.; Morlet, M.; Ong, S.; Van de Wiele, J.

    2007-08-31

    We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely polarized 3 GeV electrons from unpolarized protons at Q{sup 2}=0.15, 0.25 (GeV/c){sup 2}. The results are inconsistent with calculations solely using the elastic nucleon intermediate state and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A{sub n} provides a direct probe of the imaginary component of the 2{gamma} exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments.

  20. Effects of Electrons, Protons, and Ultraviolet Radiation on Thermophysical Properties of Polymeric Films

    NASA Technical Reports Server (NTRS)

    Russell, Dennis A.; Connell, John W.; Fogdall, Lawrence B.; Winkler, Werner W.

    2001-01-01

    The response of coated thin polymer films to ultraviolet (UV), electron and proton radiation simultaneously has been evaluated, with selected measurements in situ. Exposure was intended to simulate the electron and proton radiation environment near the Earth-Sun Lagrangian points (LI and L2) for five years and approximately 1000 equivalent solar hours (ESH) UV. These orbital environments are relevant to several potential missions such as the Next Generation Space Telescope and Geomagnetic Storm Warning, both of which may use thin film based structures for a sunshade and solar sail, respectively. The thin film candidates (12.5 micrometers thick) consisted of commercially available materials (Kapton(R) E, HN, Upilex(R) S, CP-1, CP-2, TOR-RC, and TOR-LMBP) that were metalized on one side with vapor deposited aluminum. All of the films are aromatic polyimides, with the exception of TORLMBP, which is a copoly(arylene ether benzimidazole). The films were exposed as second surface mirrors and the effects of the exposure on solar absorptance, thermal emittance, and tensile properties were determined. The in situ changes in solar absorptance from Kapton(R) and Upilex(R) were less than 0. 1, whereas the solar absorptance of TOR and CP films increased by more than 0.3 without saturating. The thermal emittance measurements also showed that the Kapton(R) and Upilex(R) materials increased only 1-2%, but the remaining materials increased 5-8%. Based on tensile property measurements made in air following the test, the failure stress of every type of polymer film decreased as a result of irradiation. The polymers most stable in reflectance, namely Upilex(R) and Kapton(R), were also the strongest in tension before irradiation, and they retained the greatest percentage of tensile strength. The films less stable in reflectance were also weaker in tension, and lost more tensile strength as a result of irradiation. The apparent failure strain (as a percent of original gage length) of every type of polymer film except TOR-RC, decreased as a result of irradiation.

  1. Recent Results from the Relativistic Electron Proton Telescope (REPT) onboard the Van Allen Probes Mission

    NASA Astrophysics Data System (ADS)

    Kanekal, S. G.; Baker, D. N.; Elkington, S. R.; Hoxie, V. C.; Li, X.; Spence, H. E.

    2013-05-01

    We describe recent results from the REPT instruments on board Van Allen Probes mission launched on 30 August 2012. The twin spacecraft comprising the Van Allen probes mission are identically instrumented and carry a comprehensive suite of sensors characterizing magnetospheric charged particle populations, electric and magnetic fields and plasma waves. The REPT instruments comprise a well-shielded silicon solid state detector stack, with a state of the art electronics and measure electrons of ~1.5 to > 20 MeV and protons of ~17 to > 100 MeV. The instruments were commissioned 3 days after launch and continue to provide high quality measurements. We describe the Van Allen probes and the REPT instrument and report on the new and unexpected features of the outer zone electron populations observed by REPT.

  2. Contribution of Δ(1232) to real photon radiative corrections for elastic electron-proton scattering

    NASA Astrophysics Data System (ADS)

    Gerasimov, R. E.; Fadin, V. S.

    2016-12-01

    Here we consider the contribution of the Δ(1232) resonance to the real photon radiative corrections for elastic ep-scattering. The effect is found to be small for past experiments studying the unpolarized cross section, as well as for the recent VEPP-3 experiment investigating two-photon exchange effects by the precision measurement of the {e}+/- p-scattering cross section ratio.

  3. Two-photon exchange contribution to elastic electron-proton scattering

    NASA Astrophysics Data System (ADS)

    Yurov, Mikhail

    2015-04-01

    Two experimental techniques, Rosenbluth separation and recoil polarization transfer, used to extract proton's electromagnetic form factors ratio GE/GM yield markedly different results. Modern theoretical calculations suggest that two-photon exchange might be responsible for the observed discrepancy and that it is epsilon dependent. Jefferson Lab Experiment E05-017 was designed to measure the two-photon exchange contribution over a wide range of ɛ and Q2. In contrast with the conventional Rosenbluth method, E05-017 detected the elastically scattered proton rather than the electron. This approach returns a much more precise extraction of the form factor ratios. After a brief description of the experimental goals and techniques, the current status of the analysis will be presented.

  4. A Physical Relationship Between Electron-Proton Temperature Equilibration and Mach Number in Fast Collisionless Shocks

    NASA Technical Reports Server (NTRS)

    Ghavamian, Parviz; Laming, J. Martin; Rakowski, Cara E.

    2007-01-01

    The analysis of Balmer-dominated optical spectra from nonradiative (adiabatic) SNRs has shown that the ratio of the electron to proton temperature at the blast wave is close to unity at v(s) approximate or smaller than 400 km s(-1) but declines sharply down to the minimum value of m(e) /m(p) dictated by the jump conditions at shock speeds exceeding 2000 km s(-1). We propose a physical model for the heating of electrons and ions in non-cosmic-ray-dominated, strong shocks (v(s) 400 km s(-1)) wherein the electrons are heated by lower hybrid waves immediately ahead of the shock front. These waves arise naturally from the cosmic ray pressure gradient upstream from the shock. Our model predicts a nearly constant level of electron heating over a wide range of shock speeds, producing a relationship (T(e)/T(p))sub 0 proportional to v(-2/s) (proportional to M(-2)) that is fully consistent with the observations.

  5. Unbunched beam electron-proton instability in the PSR and advanced hadron facilities

    SciTech Connect

    Wang, Tai-Sen; Pisent, A.; Neuffer, D.V.

    1989-01-01

    We studied the possibility of the occurrence of transverse instability induced by trapped electrons in unbunched beams in the Proton Storage Ring and the proposed Advance Hadron Facility (AHF) at Los Alamos, as well as in the proposed Kaon Factory at TRIUMF. We found that the e-p instability may be possible for unbunched beams in the PSR but is unlikely to occur in the advanced hadron facilities. 8 refs., 4 figs.

  6. Electron, proton and hydrogen-atom transfers in photosynthetic water oxidation.

    PubMed Central

    Tommos, Cecilia

    2002-01-01

    When photosynthetic organisms developed so that they could use water as an electron source to reduce carbon dioxide, the stage was set for efficient proliferation. Algae and plants spread globally and provided the foundation for our atmosphere and for O(2)-based chemistry in biological systems. Light-driven water oxidation is catalysed by photosystem II, the active site of which contains a redox-active tyrosine denoted Y(Z), a tetramanganese cluster, calcium and chloride. In 1995, Gerald Babcock and co-workers presented the hypothesis that photosynthetic water oxidation occurs as a metallo-radical catalysed process. In this model, the oxidized tyrosine radical is generated by coupled proton/electron transfer and re-reduced by abstracting hydrogen atoms from substrate water or hydroxide-ligated to the manganese cluster. The proposed function of Y(Z) requires proton transfer from the tyrosine site upon oxidation. The oxidation mechanism of Y(Z) in an inhibited and O(2)-evolving photosystem II is discussed. Domino-deprotonation from Y(Z) to the bulk solution is shown to be consistent with a variety of data obtained on metal-depleted samples. Experimental data that suggest that the oxidation of Y(Z) in O(2)-evolving samples is coupled to proton transfer in a hydrogen-bonding network are described. Finally, a dielectric-dependent model for the proton release that is associated with the catalytic cycle of photosystem II is discussed. PMID:12437877

  7. Transverse Beam Spin Asymmetries in Forward-Angle Elastic Electron-Proton Scattering

    SciTech Connect

    David Armstrong; Francois Arvieux; Razmik Asaturyan; Todd Averett; Stephanie Bailey; Guillaume Batigne; Douglas Beck; Elizabeth Beise; Jay Benesch; Louis Bimbot; James Birchall; Angela Biselli; Peter Bosted; Elodie Boukobza; Herbert Breuer; Roger Carlini; Robert Carr; Nicholas Chant; Yu-Chiu Chao; Swapan Chattopadhyay; Russell Clark; Silviu Covrig; Anthony Cowley; Daniel Dale; Charles Davis; Willie Falk; John Finn; Tony Forest; Gregg Franklin; Christophe Furget; David Gaskell; Joseph Grames; Keith Griffioen; Klaus Grimm; Benoit Guillon; Hayko Guler; Lars Hannelius; Richard HASTY; Alice Hawthorne Allen; Tanja Horn; Kathleen Johnston; Mark Jones; Peter Kammel; Reza Kazimi; Paul King; Ameya Kolarkar; Elie Korkmaz; Wolfgang Korsch; Serge Kox; Joachim Kuhn; Jeff Lachniet; Lawrence Lee; Jason Lenoble; Eric Liatard; Jianglai Liu; Berenice Loupias; Allison Lung; Dominique Marchand; Jeffery Martin; Kenneth McFarlane; David McKee; Robert McKeown; Fernand Merchez; Hamlet Mkrtchyan; Bryan Moffit; M. Morlet; Itaru Nakagawa; Kazutaka Nakahara; Retief Neveling; Silvia Niccolai; S. Ong; Shelley Page; Vassilios Papavassiliou; Stephen Pate; Sarah Phillips; Mark Pitt; Benard Poelker; Tracy Porcelli; Gilles Quemener; Brian Quinn; William Ramsay; Aamer Rauf; Jean-Sebastien Real; Julie Roche; Philip Roos; Gary Rutledge; Jeffery Secrest; Neven Simicevic; Gregory Smith; Damon Spayde; Samuel Stepanyan; Marcy Stutzman; Vince Sulkosky; Vincent Sulkosky; Vince Sulkosky; Vincent Sulkosky; Vardan Tadevosyan; Raphael Tieulent; Jacques Van de Wiele; Willem van Oers; Eric Voutier; William Vulcan; Glen Warren; Steven Wells; Steven Williamson; Stephen Wood; Chen Yan; Junho Yun; Valdis Zeps

    2007-08-01

    We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely-polarized 3 GeV electrons from unpolarized protons at Q^2 values of 0.15 and 0.25 (GeV/c)^2 with results of A_n = -4.06 +- 0.99(stat) +- 0.63(syst) and A_n = -4.82 +- 1.87(stat) +- 0.98(syst) ppm. These results are inconsistent with calculations solely using the elastic nucleon intermediate state, and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A_n provides a direct probe of the imaginary component of the two-photon exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments.

  8. Interactive Astronomy.

    ERIC Educational Resources Information Center

    Martin, Jean K.

    1997-01-01

    Presents guiding principles for developing interactive lessons for the World Wide Web. Describes "Amazing Space: Education Online from the Hubble Space Telescope", a program where students study spectacular Hubble Space Telescope images of stars and star-forming regions to learn about the life cycle of stars and the creation of atoms. (JRH)

  9. Interacting Compasses

    ERIC Educational Resources Information Center

    Riveros, Hector G.; Betancourt, Julian

    2009-01-01

    The use of multiple compasses to map and visualize magnetic fields is well-known. The magnetic field exerts a torque on the compasses aligning them along the lines of force. Some science museums show the field of a magnet using a table with many compasses in a closely packed arrangement. However, the very interesting interactions that occur…

  10. [Pharmacokinetic interactions].

    PubMed

    Arazo Garcés, Piedad; de los Santos Gil, Ignacio

    2013-06-01

    Rilpivirine (RPV) is a nonnucleoside reverse transcriptase inhibitor (NNRTI) that has been approved for use in treatment-naïve patients and which has potent antiviral activity. Its adverse effects profile differs from that of first-generation NNRTs. The pharmacological interactions produced by RPV are due to its effects on the CYP450 system; RPV is a substrate and mild inducer of CYP3A4. Moreover, in vitro, RPV inhibits glycoprotein-P. RPV has clinically significant pharmacological interactions, especially with protease inhibitors (except boosted darunavir and lopinavir) and the NNRTIs efavirenz and nevirapine. Coadministration of RPV with drugs that increase gastric pH, such as omeprazole, or those inducing CYP3A4, such as rifampicin, can significantly reduce RPV concentrations and is contraindicated. The concomitant use of RPV with a CYP3A4 inhibitor (such as clarithromycin) can increase RPV concentrations. Administration of PRV with food is recommended to obtain better absorption and adequate plasma values.

  11. Sibling interaction.

    PubMed

    Balsam, Rosemary H

    2013-01-01

    Sibling interactions traditionally were conceived psychoanalytically in "vertical" and parentified oedipal terms and overlooked in their own right, for complicated reasons (Colonna and Newman 1983). Important work has been done to right this, from the 1980s and onward, with conferences and writings. Juliet Mitchell's 2000 and, in particular, her 2003 books, for example, have brought "lateral" sibling relations forcefully to the forefront of insights, especially about sex and violence, with the added interdisciplinary impact of illuminating upheaval in global community interactions as well as having implications for clinicians. A clinical example from the analysis of an adult woman with a ten-years-younger sister will show here how we need both concepts to help us understand complex individual psychic life. The newer "lateral" sibling emphasis, including Mitchell's "Law of the Mother" and "seriality," can be used to inform the older "vertical" take, to enrich the full dimensions of intersubjective oedipal and preoedipal reciprocities that have been foundational in shaping that particular analysand's inner landscape. Some technical recommendations for heightening sensitivity to the import of these dynamics will be offered along the way here, by invoking Hans Loewald's useful metaphor of the analytic situation as theater.

  12. Cosmic Interactions

    NASA Astrophysics Data System (ADS)

    2008-01-01

    An image based on data taken with ESO's Very Large Telescope reveals a triplet of galaxies intertwined in a cosmic dance. ESO PR Photo 02/08 ESO PR Photo 02/08 NGC 7173, 7174, and 7176 The three galaxies, catalogued as NGC 7173 (top), 7174 (bottom right) and 7176 (bottom left), are located 106 million light-years away towards the constellation of Piscis Austrinus (the 'Southern Fish'). NGC 7173 and 7176 are elliptical galaxies, while NGC 7174 is a spiral galaxy with quite disturbed dust lanes and a long, twisted tail. This seems to indicate that the two bottom galaxies - whose combined shape bears some resemblance to that of a sleeping baby - are currently interacting, with NGC 7176 providing fresh material to NGC 7174. Matter present in great quantity around the triplet's members also points to the fact that NGC 7176 and NGC 7173 have interacted in the past. Astronomers have suggested that the three galaxies will finally merge into a giant 'island universe', tens to hundreds of times as massive as our own Milky Way. ESO PR Photo 02/08 ESO PR Photo 02b/08 NGC 7173, 7174, and 7176 The triplet is part of a so-called 'Compact Group', as compiled by Canadian astronomer Paul Hickson in the early 1980s. The group, which is the 90th entry in the catalogue and is therefore known as HCG 90, actually contains four major members. One of them - NGC 7192 - lies above the trio, outside of this image, and is another peculiar spiral galaxy. Compact groups are small, relatively isolated, systems of typically four to ten galaxies in close proximity to one another. Another striking example is Robert's Quartet. Compact groups are excellent laboratories for the study of galaxy interactions and their effects, in particular the formation of stars. As the striking image reveals, there are many other galaxies in the field. Some are distant ones, while others seem to be part of the family. Studies made with other telescopes have indeed revealed that the HCG 90 group contains 16 members

  13. Electroweak interactions

    SciTech Connect

    Bjorken, J.D.

    1980-10-01

    A point of view of the electroweak interaction is presented. It begins phenomenologically and moves in stages toward the conventional gauge theory formalism containing elementary scalar Higgs-fields and then beyond. The purpose in so doing is that the success of the standard SU(2) x U(1) theory in accounting for low energy phenomena need not automatically imply success at high energies. It is deemed unlikely by most theorists that the predicted W/sup + -/ or Z/sup 0/ does not exist or does not have the mass and/or couplings anticipated in the standard model. However, the odds that the standard predictions will work are not 100%. Therefore there is some reason to look at the subject as one would were he forced by a wrong experimental outcome - to go back to fundamentals and ascertain what is the minimal amount of theory necessary to account for the data.

  14. Designing "Interaction": How Do Interaction Design Students Address Interaction?

    ERIC Educational Resources Information Center

    Karlgren, Klas; Ramberg, Robert; Artman, Henrik

    2016-01-01

    Interaction design is usually described as being concerned with interactions with and through artifacts but independent of a specific implementation. Design work has been characterized as a conversation between the designer and the situation and this conversation poses a particular challenge for interaction design as interactions can be elusive…

  15. Cloud Interactions

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 1 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.

    Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.

    This image was acquired during mid-spring near the North Pole. The linear water-ice clouds are now regional in extent and often interact with neighboring cloud system, as seen in this image. The bottom of the image shows how the interaction can destroy the linear nature. While the surface is still visible through most of the clouds, there is evidence that dust is also starting to enter the atmosphere.

    Image information: VIS instrument. Latitude 68.4, Longitude 258.8 East (101.2 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration

  16. Formation et interaction (Teacher Education and Interaction).

    ERIC Educational Resources Information Center

    Bertocchini, Paola; Costanzo, Edwige

    1989-01-01

    Effective interaction is as important in inservice education programs for language teachers as it is in the foreign language classroom. Techniques are described for improving the quality of interaction in teacher workshops through simulation exercises. (MSE)

  17. PIC: Protein Interactions Calculator

    PubMed Central

    Tina, K. G.; Bhadra, R.; Srinivasan, N.

    2007-01-01

    Interactions within a protein structure and interactions between proteins in an assembly are essential considerations in understanding molecular basis of stability and functions of proteins and their complexes. There are several weak and strong interactions that render stability to a protein structure or an assembly. Protein Interactions Calculator (PIC) is a server which, given the coordinate set of 3D structure of a protein or an assembly, computes various interactions such as disulphide bonds, interactions between hydrophobic residues, ionic interactions, hydrogen bonds, aromatic–aromatic interactions, aromatic–sulphur interactions and cation–π interactions within a protein or between proteins in a complex. Interactions are calculated on the basis of standard, published criteria. The identified interactions between residues can be visualized using a RasMol and Jmol interface. The advantage with PIC server is the easy availability of inter-residue interaction calculations in a single site. It also determines the accessible surface area and residue-depth, which is the distance of a residue from the surface of the protein. User can also recognize specific kind of interactions, such as apolar–apolar residue interactions or ionic interactions, that are formed between buried or exposed residues or near the surface or deep inside. PMID:17584791

  18. PIC: Protein Interactions Calculator.

    PubMed

    Tina, K G; Bhadra, R; Srinivasan, N

    2007-07-01

    Interactions within a protein structure and interactions between proteins in an assembly are essential considerations in understanding molecular basis of stability and functions of proteins and their complexes. There are several weak and strong interactions that render stability to a protein structure or an assembly. Protein Interactions Calculator (PIC) is a server which, given the coordinate set of 3D structure of a protein or an assembly, computes various interactions such as disulphide bonds, interactions between hydrophobic residues, ionic interactions, hydrogen bonds, aromatic-aromatic interactions, aromatic-sulphur interactions and cation-pi interactions within a protein or between proteins in a complex. Interactions are calculated on the basis of standard, published criteria. The identified interactions between residues can be visualized using a RasMol and Jmol interface. The advantage with PIC server is the easy availability of inter-residue interaction calculations in a single site. It also determines the accessible surface area and residue-depth, which is the distance of a residue from the surface of the protein. User can also recognize specific kind of interactions, such as apolar-apolar residue interactions or ionic interactions, that are formed between buried or exposed residues or near the surface or deep inside.

  19. Food and Drug Interactions.

    PubMed

    Choi, Jong Hwan; Ko, Chang Mann

    2017-01-01

    Natural foods and vegetal supplements have recently become increasingly popular for their roles in medicine and as staple foods. This has, however, led to the increased risk of interaction between prescribed drugs and the bioactive ingredients contained in these foods. These interactions range from pharmacokinetic interactions (absorption, distribution, metabolism, and excretion influencing blood levels of drugs) to pharmacodynamic interactions (drug effects). In a quantitative respect, these interactions occur mainly during metabolism. In addition to the systemic metabolism that occurs mainly in the liver, recent studies have focused on the metabolism in the gastrointestinal tract endothelium before absorption. Inhibition of metabolism causes an increase in the blood levels of drugs and could have adverse reactions. The food-drug interactions causing increased blood levels of drugs may have beneficial or detrimental therapeutic effects depending on the intensity and predictability of these interactions. It is therefore important to understand the potential interactions between foods and drugs should and the specific outcomes of such interactions.

  20. Interacting dark sector with transversal interaction

    SciTech Connect

    Chimento, Luis P.; Richarte, Martín G.

    2015-03-26

    We investigate the interacting dark sector composed of dark matter, dark energy, and dark radiation for a spatially flat Friedmann-Robertson-Walker (FRW) background by introducing a three-dimensional internal space spanned by the interaction vector Q and solve the source equation for a linear transversal interaction. Then, we explore a realistic model with dark matter coupled to a scalar field plus a decoupled radiation term, analyze the amount of dark energy in the radiation era and find that our model is consistent with the recent measurements of cosmic microwave background anisotropy coming from Planck along with the future constraints achievable by CMBPol experiment.

  1. Gestalt Interactional Groups

    ERIC Educational Resources Information Center

    Harman, Robert L.; Franklin, Richard W.

    1975-01-01

    Gestalt therapy in groups is not limited to individual work in the presence of an audience. Describes several ways to involve gestalt groups interactionally. Interactions described focus on learning by doing and discovering, and are noninterpretive. (Author/EJT)

  2. Computerized Interactive Harness Engineering

    NASA Technical Reports Server (NTRS)

    Billitti, J. W.

    1985-01-01

    Computerized interactive harness engineering program inexpensive, interactive system for learning and using engineering approach to interconnection systems. Basically data-base system that stores information as files of individual connectors and handles wiring information in circuit groups stored as records.

  3. Interactions between magnetohydrodynamical discontinuities

    SciTech Connect

    Dai, W.; Woodward, P.R. )

    1994-11-01

    Interactions between magnetohydrodynamical (MHD) discontinuities are studied through numerical simulations for the set of one-dimensional MHD equations. The interactions include the impact of a shock on a contact discontinuity, the collision of two shocks, and the catchup of a shock over another shock. The shocks involved in the interactions may be very strong. Each shock in an interaction may be either a fast or a slow shock.

  4. Interactivity: A Forgotten Art?

    ERIC Educational Resources Information Center

    Sims, Rod

    1997-01-01

    This paper promotes further discussion and analysis of interactivity in learning environments and contains a classification of interaction types appropriate for consideration in multimedia settings. Through an examination of related factors associated with navigation and control, a matrix of interactive dimensions is proposed. (Author)

  5. Global Interaction in Design

    ERIC Educational Resources Information Center

    Bennett, Audrey Grace

    2010-01-01

    Based on a virtual conference, Glide'08 (Global Interaction in Design Education), that brought international design scholars together online, this special issue expands on the topics of cross-cultural communication and design and the technological affordances that support such interaction. The author discusses the need for global interaction in…

  6. Dynamic Interactive Learning Systems

    ERIC Educational Resources Information Center

    Sabry, Khaled; Barker, Jeff

    2009-01-01

    This paper reviews and discusses the notions of interactivity and dynamicity of learning systems in relation to information technologies and design principles that can contribute to interactive and dynamic learning. It explores the concept of dynamic interactive learning systems based on the emerging generation of information as part of a…

  7. Fine Tuning of Redox Networks on Multiheme Cytochromes from Geobacter sulfurreducens Drives Physiological Electron/Proton Energy Transduction

    PubMed Central

    Morgado, Leonor; Dantas, Joana M.; Bruix, Marta; Londer, Yuri Y.; Salgueiro, Carlos A.

    2012-01-01

    The bacterium Geobacter sulfurreducens (Gs) can grow in the presence of extracellular terminal acceptors, a property that is currently explored to harvest electricity from aquatic sediments and waste organic matter into microbial fuel cells. A family composed of five triheme cytochromes (PpcA-E) was identified in Gs. These cytochromes play a crucial role by bridging the electron transfer from oxidation of cytoplasmic donors to the cell exterior and assisting the reduction of extracellular terminal acceptors. The detailed thermodynamic characterization of such proteins showed that PpcA and PpcD have an important redox-Bohr effect that might implicate these proteins in the e−/H+ coupling mechanisms to sustain cellular growth. The physiological relevance of the redox-Bohr effect in these proteins was studied by determining the fractional contribution of each individual redox-microstate at different pH values. For both proteins, oxidation progresses from a particular protonated microstate to a particular deprotonated one, over specific pH ranges. The preferred e−/H+ transfer pathway established by the selected microstates indicates that both proteins are functionally designed to couple e−/H+ transfer at the physiological pH range for cellular growth. PMID:22899897

  8. New Measurement of Parity Violation in Elastic Electron-Proton Scattering and Implications for Strange Form Factors

    SciTech Connect

    Konrad Aniol; David Armstrong; Todd Averett; Maud Baylac; Etienne Burtin; John Calarco; Gordon Cates; Christian Cavata; Zhengwei Chai; C. Chang; Jian-Ping Chen; Eugene Chudakov; Evaristo Cisbani; Marius Coman; Daniel Dale; Alexandre Deur; Pibero Djawotho; Martin Epstein; Stephanie Escoffier; Lars Ewell; Nicolas Falletto; John Finn; A. Fleck; Bernard Frois; Salvatore Frullani; Juncai Gao; Franco Garibaldi; Ashot Gasparian; G. M. Gerstner; Ronald Gilman; Oleksandr Glamazdin; Javier Gomez; Viktor Gorbenko; Jens-ole Hansen; F. Hersman; Douglas Higinbotham; Richard Holmes; Maurik Holtrop; Thomas Humensky; Sebastien Incerti; Mauro Iodice; Cornelis De Jager; Johann Jardillier; Xiaodong Jiang; Mark Jones; J. Jorda; Christophe Jutier; W. Kahl; James Kelly; Donghee Kim; M. -J. Kim; Minsuk Kim; Ioannis Kominis; Edgar Kooijman; Kevin Kramer; Krishna Kumar; Michael Kuss; John LeRose; Raffaele De Leo; M. Leuschner; David Lhuillier; Meihua Liang; Nilanga Liyanage; R. Lourie; Richard Madey; Sergey Malov; Demetrius Margaziotis; Frederic Marie; Pete Markowitz; Jacques Martino; Peter Mastromarino; Kathy McCormick; Justin McIntyre; Zein-Eddine Meziani; Robert Michaels; Brian Milbrath; Gerald Miller; Joseph Mitchell; Ludyvine Morand; Damien Neyret; Gerassimos Petratos; Roman Pomatsalyuk; John Price; David Prout; Thierry Pussieux; Gilles Quemener; Ronald Ransome; David Relyea; Yves Roblin; Julie Roche; Gary Rutledge; Paul Rutt; Marat Rvachev; Franck Sabatie; Arunava Saha; Paul Souder; Marcus Spradlin; Steffen Strauch; Riad Suleiman; Jeffrey Templon; T. Teresawa; James Thompson; Raphael Tieulent; Luminita Todor; Baris Tonguc; Paul Ulmer; Guido Urciuoli; Branislav Vlahovic; Krishni Wijesooriya; R. Wilson; Bogdan Wojtsekhowski; Rhett Woo; Wang Xu; Imran Younus; C. Zhang

    2001-06-01

    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The result is A = -15.05 +- 0.98(stat) {+-} 0.56(syst) ppm at the kinematic point theta{sub lab} = 12.3 degrees and Q{sup 2} = 0.477 (GeV/c){sup 2}. The measurement implies that the value for the strange form factor (G{sub E}{sup s} + 0.392 G{sub M}{sup s})/(G{sub M}{sup p} {mu}{sub p}) = 0.069 +- 0.056 +- 0.039, where the first error is experimental and the second arises from the uncertainties in electromagnetic form factors. This measurement is the first fixed-target parity violation experiment that used either a ''strained'' GaAs photocathode to produce highly polarized electrons or a Compton polarimeter to continuously monitor the electron beam polarization.

  9. Evolving synergetic interactions

    PubMed Central

    Wu, Bin; Arranz, Jordi; Du, Jinming; Zhou, Da; Traulsen, Arne

    2016-01-01

    Cooperators forgo their own interests to benefit others. This reduces their fitness and thus cooperators are not likely to spread based on natural selection. Nonetheless, cooperation is widespread on every level of biological organization ranging from bacterial communities to human society. Mathematical models can help to explain under which circumstances cooperation evolves. Evolutionary game theory is a powerful mathematical tool to depict the interactions between cooperators and defectors. Classical models typically involve either pairwise interactions between individuals or a linear superposition of these interactions. For interactions within groups, however, synergetic effects may arise: their outcome is not just the sum of its parts. This is because the payoffs via a single group interaction can be different from the sum of any collection of two-player interactions. Assuming that all interactions start from pairs, how can such synergetic multiplayer games emerge from simpler pairwise interactions? Here, we present a mathematical model that captures the transition from pairwise interactions to synergetic multiplayer ones. We assume that different social groups have different breaking rates. We show that non-uniform breaking rates do foster the emergence of synergy, even though individuals always interact in pairs. Our work sheds new light on the mechanisms underlying such synergetic interactions. PMID:27466437

  10. The Interactive Learning Toolkit: supporting interactive classrooms

    NASA Astrophysics Data System (ADS)

    Dutta, S.; McCauley, V.; Mazur, E.

    2004-05-01

    Research-based interactive learning techniques have dramatically improved student understanding. We have created the 'Interactive Learning Toolkit' (ILT), a web-based learning management system, to help implement two such pedagogies: Just in Time Teaching and Peer Instruction. Our main goal in developing this toolkit is to save the instructor time and effort and to use technology to facilitate the interaction between the students and the instructor (and between students themselves). After a brief review of both pedagogies, we will demonstrate the many exciting new features of the ILT. We will show how technology can not only implement, but also supplement and improve these pedagogies. We would like acknowdge grants from NSF and DEAS, Harvard University

  11. [Drug-drug interactions: interactions between xenobiotics].

    PubMed

    Haen, E

    2014-04-01

    Drug-drug interactions (DDI) are a major topic in programs for continuous medical education (CME). Many physicians are afraid of being trapped into charges of malpractice; however, DDI cannot be avoided in many cases. They belong to routine medical practice and it is often impossible to avoid them. Moreover, they do not just occur between drugs but between any kind of foreign substance (xenobiotica), such as food (e.g. grapefruit juice, broccoli, barbecue) as well as legal (e.g. tobacco smoke, caffeine and alcohol) and illegal drugs. Therefore, the medical challenge is not just to avoid any interaction. Instead the physician faces the question of how to proceed with drug treatment in the presence of such interactions. Based on the medical education a physician has to judge first of all whether there is a risk for interactions in the prescription being planned for an individual patient. The classification of interactions proposed in this article (PD1-PD4, PK1-PK3) might help as a sort of check list. For more detailed information the physician can then consult one of the many databases available on the internet, such as PSIAConline (http://www.psiac.de) and MediQ (http://www.mediq.ch). Pharmacokinetic interactions can be easily assessed, monitored and controlled by therapeutic drug monitoring (TDM). Besides these tools it is important to keep in mind that nobody knows everything; even physicians do not know everything. So take pride in asking someone who might help and for this purpose AGATE offers a drug information service AID (http://www.amuep-agate.de). Just good for nothing, without being based on any kind of medical approach are computer programs that judge prescriptions without taking into account a patient's individual peculiarities. In case these types of programs produce red exclamation marks or traffic lights to underline their judgment, they might even work in a contrapuntal way by just eliciting insecurity and fear.

  12. The interactive brain hypothesis

    PubMed Central

    Di Paolo, Ezequiel; De Jaegher, Hanne

    2012-01-01

    Enactive approaches foreground the role of interpersonal interaction in explanations of social understanding. This motivates, in combination with a recent interest in neuroscientific studies involving actual interactions, the question of how interactive processes relate to neural mechanisms involved in social understanding. We introduce the Interactive Brain Hypothesis (IBH) in order to help map the spectrum of possible relations between social interaction and neural processes. The hypothesis states that interactive experience and skills play enabling roles in both the development and current function of social brain mechanisms, even in cases where social understanding happens in the absence of immediate interaction. We examine the plausibility of this hypothesis against developmental and neurobiological evidence and contrast it with the widespread assumption that mindreading is crucial to all social cognition. We describe the elements of social interaction that bear most directly on this hypothesis and discuss the empirical possibilities open to social neuroscience. We propose that the link between coordination dynamics and social understanding can be best grasped by studying transitions between states of coordination. These transitions form part of the self-organization of interaction processes that characterize the dynamics of social engagement. The patterns and synergies of this self-organization help explain how individuals understand each other. Various possibilities for role-taking emerge during interaction, determining a spectrum of participation. This view contrasts sharply with the observational stance that has guided research in social neuroscience until recently. We also introduce the concept of readiness to interact to describe the practices and dispositions that are summoned in situations of social significance (even if not interactive). This latter idea links interactive factors to more classical observational scenarios. PMID:22701412

  13. How Interactive Is the Interactive Whiteboard?

    ERIC Educational Resources Information Center

    Quashie, Valerie

    2009-01-01

    An interactive whiteboard (IWB) is simply a surface onto which a computer screen can be displayed, via a projector. It is touch-sensitive and lets one use a pen like a mouse, controlling the computer from the board itself. Everything that can be displayed on a computer can be displayed onto the whiteboard and, if the computer is linked to speakers…

  14. Food-drug interactions.

    PubMed

    Bushra, Rabia; Aslam, Nousheen; Khan, Arshad Yar

    2011-03-01

    The effect of drug on a person may be different than expected because that drug interacts with another drug the person is taking (drug-drug interaction), food, beverages, dietary supplements the person is consuming (drug-nutrient/food interaction) or another disease the person has (drug-disease interaction). A drug interaction is a situation in which a substance affects the activity of a drug, i.e. the effects are increased or decreased, or they produce a new effect that neither produces on its own. These interactions may occur out of accidental misuse or due to lack of knowledge about the active ingredients involved in the relevant substances. Regarding food-drug interactions physicians and pharmacists recognize that some foods and drugs, when taken simultaneously, can alter the body's ability to utilize a particular food or drug, or cause serious side effects. Clinically significant drug interactions, which pose potential harm to the patient, may result from changes in pharmaceutical, pharmacokinetic, or pharmacodynamic properties. Some may be taken advantage of, to the benefit of patients, but more commonly drug interactions result in adverse drug events. Therefore it is advisable for patients to follow the physician and doctors instructions to obtain maximum benefits with least food-drug interactions. The literature survey was conducted by extracting data from different review and original articles on general or specific drug interactions with food. This review gives information about various interactions between different foods and drugs and will help physicians and pharmacists prescribe drugs cautiously with only suitable food supplement to get maximum benefit for the patient.

  15. Food and Drug Interactions

    PubMed Central

    Choi, Jong Hwan; Ko, Chang Mann

    2017-01-01

    Natural foods and vegetal supplements have recently become increasingly popular for their roles in medicine and as staple foods. This has, however, led to the increased risk of interaction between prescribed drugs and the bioactive ingredients contained in these foods. These interactions range from pharmacokinetic interactions (absorption, distribution, metabolism, and excretion influencing blood levels of drugs) to pharmacodynamic interactions (drug effects). In a quantitative respect, these interactions occur mainly during metabolism. In addition to the systemic metabolism that occurs mainly in the liver, recent studies have focused on the metabolism in the gastrointestinal tract endothelium before absorption. Inhibition of metabolism causes an increase in the blood levels of drugs and could have adverse reactions. The food-drug interactions causing increased blood levels of drugs may have beneficial or detrimental therapeutic effects depending on the intensity and predictability of these interactions. It is therefore important to understand the potential interactions between foods and drugs should and the specific outcomes of such interactions. PMID:28261555

  16. The Science of Interaction

    SciTech Connect

    Pike, William A.; Stasko, John T.; Chang, Remco; O'Connell, Theresa

    2009-09-23

    There is a growing recognition with the visual analytics community that interaction and inquiry are inextricable. It is through the interactive manipulation of a visual interface – the analytic discourse – that knowledge is constructed, tested, refined, and shared. This paper reflects on the interaction challenges raised in the original visual analytics research and development agenda and further explores the relationship between interaction and cognition. It identifies recent exemplars of visual analytics research that have made substantive progress toward the goals of a true science of interaction, which must include theories and testable premises about the most appropriate mechanisms for human-information interaction. Six areas for further work are highlighted as those among the highest priorities for the next five years of visual analytics research: ubiquitous, embodied interaction; capturing user intentionality; knowledge-based interfaces; principles of design and perception; collaboration; and interoperability. Ultimately, the goal of a science of interaction is to support the visual analytics community through the recognition and implementation of best practices in the representation of and interaction with visual displays.

  17. Two interacting Hofstadter butterflies

    SciTech Connect

    Barelli, A.; Bellissard, J.; Jacquod, P.; Shepelyansky, D.L.

    1997-04-01

    The problem of two interacting particles in a quasiperiodic potential is addressed. Using analytical and numerical methods, we explore the spectral properties and eigenstates structure from the weak to the strong interaction case. More precisely, a semiclassical approach based on noncommutative geometry techniques is used to understand the intricate structure of such a spectrum. An interaction induced localization effect is furthermore emphasized. We discuss the application of our results on a two-dimensional model of two particles in a uniform magnetic field with on-site interaction. {copyright} {ital 1997} {ital The American Physical Society}

  18. Gender interactions and success.

    PubMed

    Wiggins, Carla; Peterson, Teri

    2004-01-01

    Does gender by itself, or does gender's interaction with career variables, better explain the difference between women and men's careers in healthcare management? US healthcare managers were surveyed regarding career and personal experiences. Gender was statistically interacted with explanatory variables. Multiple regression with backwards selection systematically removed non-significant variables. All gender interaction variables were non-significant. Much of the literature proposes that work and career factors impact working women differently than working men. We find that while gender alone is a significant predictor of income, it does not significantly interact with other career variables.

  19. Reconceptualizing sex, brain and psychopathology: interaction, interaction, interaction

    PubMed Central

    Joel, D; Yankelevitch-Yahav, R

    2014-01-01

    In recent years there has been a growing recognition of the influence of sex on brain structure and function, and in relation, on the susceptibility, prevalence and response to treatment of psychiatric disorders. Most theories and descriptions of the effects of sex on the brain are dominated by an analogy to the current interpretation of the effects of sex on the reproductive system, according to which sex is a divergence system that exerts a unitary, overriding and serial effect on the form of other systems. We shortly summarize different lines of evidence that contradict aspects of this analogy. The new view that emerges from these data is of sex as a complex system whose different components interact with one another and with other systems to affect body and brain. The paradigm shift that this understanding calls for is from thinking of sex in terms of sexual dimorphism and sex differences, to thinking of sex in terms of its interactions with other factors and processes. Our review of data obtained from animal models of psychopathology clearly reveals the need for such a paradigmatic shift, because in the field of animal behaviour whether a sex difference exists and its direction depend on the interaction of many factors including, species, strain, age, specific test employed and a multitude of environmental factors. We conclude by explaining how the new conceptualization can account for sex differences in psychopathology. Linked Articles This article is part of a themed section on Animal Models in Psychiatry Research. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-20 PMID:24758640

  20. Drug-nutrient interactions.

    PubMed

    Chan, Lingtak-Neander

    2013-07-01

    Drug-nutrient interactions are defined as physical, chemical, physiologic, or pathophysiologic relationships between a drug and a nutrient. The causes of most clinically significant drug-nutrient interactions are usually multifactorial. Failure to identify and properly manage drug-nutrient interactions can lead to very serious consequences and have a negative impact on patient outcomes. Nevertheless, with thorough review and assessment of the patient's history and treatment regimens and a carefully executed management strategy, adverse events associated with drug-nutrient interactions can be prevented. Based on the physiologic sequence of events after a drug or a nutrient has entered the body and the mechanism of interactions, drug-nutrient interactions can be categorized into 4 main types. Each type of interaction can be managed using similar strategies. The existing data that guide the clinical management of most drug-nutrient interactions are mostly anecdotal experience, uncontrolled observations, and opinions, whereas the science in understanding the mechanism of drug-nutrient interactions remains limited. The challenge for researchers and clinicians is to increase both basic and higher level clinical research in this field to bridge the gap between the science and practice. The research should aim to establish a better understanding of the function, regulation, and substrate specificity of the nutrient-related enzymes and transport proteins present in the gastrointestinal tract, as well as assess how the incidence and management of drug-nutrient interactions can be affected by sex, ethnicity, environmental factors, and genetic polymorphisms. This knowledge can help us develop a true personalized medicine approach in the prevention and management of drug-nutrient interactions.

  1. Gauge theories of weak interactions II (Circa 1981-1982 C.E.)

    NASA Astrophysics Data System (ADS)

    Bég, M. A. B.; Sirlin, A.

    1982-08-01

    -new-physics desert in the energy interval 10 2 GeV-10 14GeV. Under the heading “extensions of standard QFD” we consider possible ways of making the desert bloom, which are tied to the canonical methodology; mentioned here are QFD models which survived the discovery in 1978, of parity nonconservation in the electron proton interaction; also mentioned are a few models that did not survive but which appear to be resurrectable by simple adjustment of the Higgs sector. More radical possibilities are considered in the penultimate section, on “generalizations of QFD”, where we present a critical review of recent theoretical speculations about dynamical symmetry breaking, composite models of quarks and leptons and the status of QFD as a fundamental theory. We conclude with a catalogue of unsolved problems and an appraisal of the outlook.

  2. Visualizing Dispersion Interactions

    ERIC Educational Resources Information Center

    Gottschalk, Elinor; Venkataraman, Bhawani

    2014-01-01

    An animation and accompanying activity has been developed to help students visualize how dispersion interactions arise. The animation uses the gecko's ability to walk on vertical surfaces to illustrate how dispersion interactions play a role in macroscale outcomes. Assessment of student learning reveals that students were able to develop…

  3. University-industry interaction

    NASA Technical Reports Server (NTRS)

    Hastings, Daniel E.

    1990-01-01

    It is posited that university industry interaction is highly desirable from the viewpoint of the long term economic development of the country as well as being desirable for the Space Grant Programs. The present and future possible interactions are reviewed for the three university levels namely, undergraduate, graduate, and faculty research.

  4. Interactive Visualization of Dependencies

    ERIC Educational Resources Information Center

    Moreno, Camilo Arango; Bischof, Walter F.; Hoover, H. James

    2012-01-01

    We present an interactive tool for browsing course requisites as a case study of dependency visualization. This tool uses multiple interactive visualizations to allow the user to explore the dependencies between courses. A usability study revealed that the proposed browser provides significant advantages over traditional methods, in terms of…

  5. Storyboarding Multimedia Interactions.

    ERIC Educational Resources Information Center

    Martin, Linda C.

    2000-01-01

    Understanding how to include interactivity when designing multimedia-based training (MBT) storyboards is a major key for a successful MBT. Discusses the basic formats of interactions and when to use each format. Describes how to storyboard and areas to address, including: the display area, prompts, branching, programming and graphics notes,…

  6. Interactive Presentation of Content

    ERIC Educational Resources Information Center

    Magdin, Martin; Turcáni, Milan; Vrábel, Marek

    2009-01-01

    In the paper we discus about design of universal environment for solution of creating effective multimedia applications with accent on the implementation of interactive elements with the possibility of using the adaptive systems (AS). We also discuss about possibilities of offline presentation of this interactive multimedia adaptive animations…

  7. Interactive TV: The Sequel.

    ERIC Educational Resources Information Center

    Brown, Eric

    1998-01-01

    Examines the future of interactive TV where consumers navigate the Internet on their TVs with WebTV set-top boxes. Focuses on competition between cable companies and computer and consumer electronics companies. Highlights nine companies and partnerships developing interactive hardware and services. (PEN)

  8. Normal Shock Vortex Interaction

    DTIC Science & Technology

    2003-03-01

    Figure 9: Breakdown map for normal-shock vortex-interaction. References [1] O. Thomer, W. Schroder and M. Meinke , Numerical Simulation of Normal...and Oblique-Shock Vortex Interaction, ZAMM Band 80, Sub. 1, pp. 181-184, 2000. [2] O. Thomer, E. Krause, W. Schroder and M. Meinke , Computational

  9. Let Social Interaction Flourish

    ERIC Educational Resources Information Center

    Case, Anny Fritzen

    2016-01-01

    The author describes lessons learned--through a high school project that grouped English language learners with native speakers to create a video--about ways to foster respectful, productive interaction among English learners and peers who are native speakers. The potential benefits of students who are just learning English interacting socially…

  10. Elementary particle interactions

    SciTech Connect

    Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Ward, B.F.L.; Close, F.E.; Christophorou, L.G.

    1990-10-01

    This report discusses freon bubble chamber experiments exposed to {mu}{sup +} and neutrinos, photon-proton interactions; shower counter simulations; SLD detectors at the Stanford Linear Collider, and the detectors at the Superconducting Super Collider; elementary particle interactions; physical properties of dielectric materials used in High Energy Physics detectors; and Nuclear Physics. (LSP)

  11. Spacelab user interaction

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The results of the third and final phase of a study undertaken to define means of optimizing the Spacelab experiment data system by interactively manipulating the flow of data were presented. A number of payload applicable interactive techniques and an integrated interaction system for each of two possible payloads are described. These interaction systems have been functionally defined and are accompanied with block diagrams, hardware specifications, software sizing and speed requirements, operational procedures and cost/benefits analysis data for both onboard and ground based system elements. It is shown that accrued benefits are attributable to a reduction in data processing costs obtained by, generally, a considerable reduction in the quantity of data that might otherwise be generated without interaction. One other additional anticipated benefit includes the increased scientific value obtained by the quicker return of all useful data.

  12. Venus: Interaction with Solar Wind

    NASA Astrophysics Data System (ADS)

    Russell, C.; Luhmann, J.; Murdin, P.

    2002-07-01

    The solar wind interaction with VENUS provides the archetypal interaction of a flowing magnetized PLASMA with a PLANETARY IONOSPHERE. Mars interacts with the solar wind in much the same way as does Venus, while the rotating plasma in the Saturnian magnetosphere is believed to interact similarly with its moon, Titan (see SATURN: MAGNETOSPHERE INTERACTION WITH TITAN). The interaction of the Jovian ...

  13. The ADAMS interactive interpreter

    SciTech Connect

    Rietscha, E.R.

    1990-12-17

    The ADAMS (Advanced DAta Management System) project is exploring next generation database technology. Database management does not follow the usual programming paradigm. Instead, the database dictionary provides an additional name space environment that should be interactively created and tested before writing application code. This document describes the implementation and operation of the ADAMS Interpreter, an interactive interface to the ADAMS data dictionary and runtime system. The Interpreter executes individual statements of the ADAMS Interface Language, providing a fast, interactive mechanism to define and access persistent databases. 5 refs.

  14. Cefuroxime antacid interactions.

    PubMed

    Sultana, N; Mubeen, T; Arayne, M S; Ifzal, R

    2001-01-01

    Cefuroxime sodium a second generation semi-synthetic cephalosporin is effective for treating meningitis, lower respiratory tract infections, gonorrhea, bone and joint infections and is approved for surgical prophylaxis. There are number of synergistic and as well as antagonistic drug interactions reported for this antibiotic. Withstanding to gastric irritations caused by this antibiotic, antacids may possibly be co-administered with cefuroxime, which may result in severe adverse drug interaction. The present work describes the effect of magnesium carbonate, magnesium hydroxide, magnesium trisilicate, megaldrate powder, sodium bicarbonate, aluminum oxide and simethicone suspension on the in vitro availability of cefuroxime sodium. The mechanism of interaction between antibiotic and antacids was also studied.

  15. Novel QCD Phenomena at the LHeC

    SciTech Connect

    Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins

    2011-06-22

    The proposed electron-proton/ion collider at CERN, the LHeC, can test fundamental and novel aspects of QCD and electroweak interactions as well as explore physics beyond the standard model over an exceptionally large kinematic range.

  16. Interactive Science on Mars

    NASA Astrophysics Data System (ADS)

    Mercer, C. R.; Landis, G. A.

    2017-02-01

    Swarms of small citizen-driven rovers can conduct Mars surface science missions. Transportation and communication technology needed for human exploration can enable this new interactive science mission architecture.

  17. Chasing Ecological Interactions.

    PubMed

    Jordano, Pedro

    2016-09-01

    Basic research on biodiversity has concentrated on individual species-naming new species, studying distribution patterns, and analyzing their evolutionary relationships. Yet biodiversity is more than a collection of individual species; it is the combination of biological entities and processes that support life on Earth. To understand biodiversity we must catalog it, but we must also assess the ways species interact with other species to provide functional support for the Tree of Life. Ecological interactions may be lost well before the species involved in those interactions go extinct; their ecological functions disappear even though they remain. Here, I address the challenges in studying the functional aspects of species interactions and how basic research is helping us address the fast-paced extinction of species due to human activities.

  18. Atomic & Molecular Interactions

    SciTech Connect

    2002-07-12

    The Gordon Research Conference (GRC) on Atomic & Molecular Interactions was held at Roger Williams University, Bristol, RI. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  19. Interactive Office user's manual

    NASA Technical Reports Server (NTRS)

    Montgomery, Edward E.; Lowers, Benjamin; Nabors, Terri L.

    1990-01-01

    Given here is a user's manual for Interactive Office (IO), an executive office tool for organization and planning, written specifically for Macintosh. IO is a paperless management tool to automate a related group of individuals into one productive system.

  20. Chasing Ecological Interactions

    PubMed Central

    2016-01-01

    Basic research on biodiversity has concentrated on individual species—naming new species, studying distribution patterns, and analyzing their evolutionary relationships. Yet biodiversity is more than a collection of individual species; it is the combination of biological entities and processes that support life on Earth. To understand biodiversity we must catalog it, but we must also assess the ways species interact with other species to provide functional support for the Tree of Life. Ecological interactions may be lost well before the species involved in those interactions go extinct; their ecological functions disappear even though they remain. Here, I address the challenges in studying the functional aspects of species interactions and how basic research is helping us address the fast-paced extinction of species due to human activities. PMID:27631692

  1. Interactive Design Activism

    NASA Astrophysics Data System (ADS)

    Goulev, Petar; Farrer, Joan

    The following sections are included: * Introduction * Computers and Human Well-being * To Fuzzy or Yes (No)! * Interactive Design Activism * Sensing the Sun * Personalised Public Health Advice * Modifying Human Behaviour * Transdisciplinarity, Knowledge Transfer and Multi-domain

  2. Towards interactive narrative medicine.

    PubMed

    Cavazza, Marc; Charles, Fred

    2013-01-01

    Interactive Storytelling technologies have attracted significant interest in the field of simulation and serious gaming for their potential to provide a principled approach to improve user engagement in training scenarios. In this paper, we explore the use of Interactive Storytelling to support Narrative Medicine as a reflective practice. We describe a workflow for the generation of virtual narratives from high-level descriptions of patients' experiences as perceived by physicians, which can help to objectivize such perceptions and support various forms of analysis.

  3. Vortice-propeller interaction

    NASA Astrophysics Data System (ADS)

    Hemon, Alain; Huberson, Serge

    1989-08-01

    The interactions between a ship's propeller blades and the boundary layer created by the ship are investigated. A finite element calculation method based on Navier-Stokes equation is developed. The application of an k-epsilon turbulence model for improving the analysis is considered. The flow azimuthal homogenization hypothesis is applied and leads to an accurate evaluation of the propeller performances. The unsteady effects generated by the interaction between the propeller blades and the vortices are analyzed.

  4. Replicators with Hebb interactions

    NASA Astrophysics Data System (ADS)

    de Oliveira, V. M.

    2003-01-01

    We do an analytical study of the statistical properties of an ecosystem composed of species that are coupled via pairwise interactions that are given by the Hebb rule and have deterministic self-interactions u. In the model each species is characterized by an infinite set of p = αN traits. As one of our main results, we observe that the ecosystem becomes less cooperative as the complexity of species (number of traits) is increased.

  5. Grapefruit and drug interactions.

    PubMed

    2012-12-01

    Since the late 1980s, grapefruit juice has been known to affect the metabolism of certain drugs. Several serious adverse effects involving drug interactions with grapefruit juice have been published in detail. The components of grapefruit juice vary considerably depending on the variety, maturity and origin of the fruit, local climatic conditions, and the manufacturing process. No single component accounts for all observed interactions. Other grapefruit products are also occasionally implicated, including preserves, lyophylised grapefruit juice, powdered whole grapefruit, grapefruit seed extract, and zest. Clinical reports of drug interactions with grapefruit juice are supported by pharmacokinetic studies, each usually involving about 10 healthy volunteers, in which the probable clinical consequences were extrapolated from the observed plasma concentrations. Grapefruit juice inhibits CYP3A4, the cytochrome P450 isoenzyme most often involved in drug metabolism. This increases plasma concentrations of the drugs concerned, creating a risk of overdose and dose-dependent adverse effects. Grapefruit juice also inhibits several other cytochrome P450 isoenzymes, but they are less frequently implicated in interactions with clinical consequences. Drugs interacting with grapefruit and inducing serious clinical consequences (confirmed or very probable) include: immunosuppressants, some statins, benzodiazepines, most calcium channel blockers, indinavir and carbamazepine. There are large inter-individual differences in enzyme efficiency. Along with the variable composition of grapefruit juice, this makes it difficult to predict the magnitude and clinical consequences of drug interactions with grapefruit juice in a given patient. There is increasing evidence that transporter proteins such as organic anion transporters and P-glycoprotein are involved in interactions between drugs and grapefruit juice. In practice, numerous drugs interact with grapefruit juice. Although only a few

  6. PIA: ISOPHOT Interactive Analysis

    NASA Astrophysics Data System (ADS)

    Gabriel, Carlos; Acosta, Jose; Heinrichsen, Ingolf; Skaley, Detlef; Tai, Wai Ming; Morris, Huw; Merluzzi, Paola

    2014-08-01

    ISOPHOT is one of the instruments on board the Infrared Space Observatory (ISO). ISOPHOT Interactive Analysis (PIA) is a scientific and calibration interactive data analysis tool for ISOPHOT data reduction. Written in IDL under Xwindows, PIA offers a full context sensitive graphical interface for retrieving, accessing and analyzing ISOPHOT data. It is available in two nearly identical versions; a general observers version omits the calibration sequences.

  7. Food-drug interactions.

    PubMed

    Schmidt, Lars E; Dalhoff, Kim

    2002-01-01

    Interactions between food and drugs may inadvertently reduce or increase the drug effect. The majority of clinically relevant food-drug interactions are caused by food-induced changes in the bioavailability of the drug. Since the bioavailability and clinical effect of most drugs are correlated, the bioavailability is an important pharmacokinetic effect parameter. However, in order to evaluate the clinical relevance of a food-drug interaction, the impact of food intake on the clinical effect of the drug has to be quantified as well. As a result of quality review in healthcare systems, healthcare providers are increasingly required to develop methods for identifying and preventing adverse food-drug interactions. In this review of original literature, we have tried to provide both pharmacokinetic and clinical effect parameters of clinically relevant food-drug interactions. The most important interactions are those associated with a high risk of treatment failure arising from a significantly reduced bioavailability in the fed state. Such interactions are frequently caused by chelation with components in food (as occurs with alendronic acid, clodronic acid, didanosine, etidronic acid, penicillamine and tetracycline) or dairy products (ciprofloxacin and norfloxacin), or by other direct interactions between the drug and certain food components (avitriptan, indinavir, itraconazole solution, levodopa, melphalan, mercaptopurine and perindopril). In addition, the physiological response to food intake, in particular gastric acid secretion, may reduce the bioavailability of certain drugs (ampicillin, azithromycin capsules, didanosine, erythromycin stearate or enteric coated, and isoniazid). For other drugs, concomitant food intake may result in an increase in drug bioavailability either because of a food-induced increase in drug solubility (albendazole, atovaquone, griseofulvin, isotretinoin, lovastatin, mefloquine, saquinavir and tacrolimus) or because of the secretion of

  8. Beam-Material Interaction

    SciTech Connect

    Mokhov, N. V.; Cerutti, F.

    2016-01-01

    Th is paper is motivated by the growing importance of better understanding of the phenomena and consequences of high-intensity energetic particle beam interactions with accelerator, generic target, and detector components. It reviews the principal physical processes of fast-particle interactions with matter, effects in materials under irradiation, materials response, related to component lifetime and performance, simulation techniques, and methods of mitigating the impact of radiation on the components and environment in challenging current and future applications.

  9. Human-machine interactions

    DOEpatents

    Forsythe, J. Chris; Xavier, Patrick G.; Abbott, Robert G.; Brannon, Nathan G.; Bernard, Michael L.; Speed, Ann E.

    2009-04-28

    Digital technology utilizing a cognitive model based on human naturalistic decision-making processes, including pattern recognition and episodic memory, can reduce the dependency of human-machine interactions on the abilities of a human user and can enable a machine to more closely emulate human-like responses. Such a cognitive model can enable digital technology to use cognitive capacities fundamental to human-like communication and cooperation to interact with humans.

  10. Interactive DIF Generator

    NASA Technical Reports Server (NTRS)

    Preheim, Larry E.; Amy, Laraine; Young, Jimmie D.

    1993-01-01

    Interactive DIF Generator (IDG) computer program serves as utility to generate and manipulate directory interchange format (DIF) files. Creates and updates DIF files, sent to NASA's Master Directory, also referred to as International Global Change Directory at Goddard Space Flight Center. Many government and university data systems use Master Directory to advertise availability of research data. IDG is interactive software tool and requires mouse or trackball to operate. Written in C language.

  11. Flank solar wind interaction

    NASA Technical Reports Server (NTRS)

    Moses, Stewart L.; Greenstadt, Eugene W.; Coroniti, Ferdinand V.

    1994-01-01

    In this report we will summarize the results of the work performed under the 'Flank Solar Wind Interaction' investigation in support of NASA's Space Physics Guest Investigator Program. While this investigation was focused on the interaction of the Earth's magnetosphere with the solar wind as observed by instruments on the International Sun-Earth Explorer (ISEE) 3 spacecraft, it also represents the culmination of decades of research performed by scientists at TRW on the rich phenomenology of collisionless shocks in space.

  12. Interaction with Machine Improvisation

    NASA Astrophysics Data System (ADS)

    Assayag, Gerard; Bloch, George; Cont, Arshia; Dubnov, Shlomo

    We describe two multi-agent architectures for an improvisation oriented musician-machine interaction systems that learn in real time from human performers. The improvisation kernel is based on sequence modeling and statistical learning. We present two frameworks of interaction with this kernel. In the first, the stylistic interaction is guided by a human operator in front of an interactive computer environment. In the second framework, the stylistic interaction is delegated to machine intelligence and therefore, knowledge propagation and decision are taken care of by the computer alone. The first framework involves a hybrid architecture using two popular composition/performance environments, Max and OpenMusic, that are put to work and communicate together, each one handling the process at a different time/memory scale. The second framework shares the same representational schemes with the first but uses an Active Learning architecture based on collaborative, competitive and memory-based learning to handle stylistic interactions. Both systems are capable of processing real-time audio/video as well as MIDI. After discussing the general cognitive background of improvisation practices, the statistical modelling tools and the concurrent agent architecture are presented. Then, an Active Learning scheme is described and considered in terms of using different improvisation regimes for improvisation planning. Finally, we provide more details about the different system implementations and describe several performances with the system.

  13. Sperm-egg interaction.

    PubMed

    Evans, Janice P

    2012-01-01

    A crucial step of fertilization is the sperm-egg interaction that allows the two gametes to fuse and create the zygote. In the mouse, CD9 on the egg and IZUMO1 on the sperm stand out as critical players, as Cd9(-/-) and Izumo1(-/-) mice are healthy but infertile or severely subfertile due to defective sperm-egg interaction. Moreover, work on several nonmammalian organisms has identified some of the most intriguing candidates implicated in sperm-egg interaction. Understanding of gamete membrane interactions is advancing through characterization of in vivo and in vitro fertilization phenotypes, including insights from less robust phenotypes that highlight potential supporting (albeit not absolutely essential) players. An emerging theme is that there are varied roles for gamete molecules that participate in sperm-egg interactions. Such roles include not only functioning as fusogens, or as adhesion molecules for the opposite gamete, but also functioning through interactions in cis with other proteins to regulate membrane order and functionality.

  14. Dike/Drift Interactions

    SciTech Connect

    E. Gaffiney

    2004-11-23

    This report presents and documents the model components and analyses that represent potential processes associated with propagation of a magma-filled crack (dike) migrating upward toward the surface, intersection of the dike with repository drifts, flow of magma in the drifts, and post-magma emplacement effects on repository performance. The processes that describe upward migration of a dike and magma flow down the drift are referred to as the dike intrusion submodel. The post-magma emplacement processes are referred to as the post-intrusion submodel. Collectively, these submodels are referred to as a conceptual model for dike/drift interaction. The model components and analyses of the dike/drift interaction conceptual model provide the technical basis for assessing the potential impacts of an igneous intrusion on repository performance, including those features, events, and processes (FEPs) related to dike/drift interaction (Section 6.1).

  15. Achromatic Interaction Point Design

    SciTech Connect

    Guimei Wang,, Yaroslav Derbenev, S.Alex Bogacz, P. Chevtsov, Andre Afanaciev, Charles Ankenbrandt, Valentin Ivanov, Rolland P. Johnson

    2009-05-01

    Designers of high-luminosity energy-frontier muon colliders must provide strong beam focusing in the interaction regions. However, the construction of a strong, aberration-free beam focus is difficult and space consuming, and long straight sections generate an off-site radiation problem due to muon decay neutrinos that interact as they leave the surface of the earth. Without some way to mitigate the neutrino radiation problem, the maximum c.m. energy of a muon collider will be limited to about 3.5 TeV. A new concept for achromatic low beta design is being developed, in which the interaction region telescope and optical correction elements, are installed in the bending arcs. The concept, formulated analytically, combines space economy, a preventative approach to compensation for aberrations, and a reduction of neutrino flux concentration. An analytical theory for the aberration-free, low beta, spatially compact insertion is being developed.

  16. Interactions of anabolic steroids.

    PubMed

    Kopera, H

    1993-01-01

    Drug-drug interactions, or interference between drugs and other treatments, depend on many factors and are therefore difficult to predict. However, a number are clearly established in the case of anabolic-androgenic steroids. The beneficial interactions between anabolic steroids and radiotherapy or cytostatic drugs respectively are of therapeutic value. Adjuvant treatment with anabolic compounds in patients undergoing radiation and/or cytostatic therapy is beneficial because it can prevent or reduce depression of erythropoiesis, granulopoiesis and thrombopoiesis. It also diminishes protein catabolism, supports recovery, improves the general condition of the patient and minimizes radiation sickness. Potentially adverse interactions with anabolic steroids must be expected in the case of oral anticoagulants and antidiabetic drugs, since sensitivity to each of the latter is increased. This makes it particularly advisable to monitor patients receiving either oral anticoagulants or antidiabetic treatment concurrently with anabolic drugs.

  17. History of Weak Interactions

    DOE R&D Accomplishments Database

    Lee, T. D.

    1970-07-01

    While the phenomenon of beta-decay was discovered near the end of the last century, the notion that the weak interaction forms a separate field of physical forces evolved rather gradually. This became clear only after the experimental discoveries of other weak reactions such as muon-decay, muon-capture, etc., and the theoretical observation that all these reactions can be described by approximately the same coupling constant, thus giving rise to the notion of a universal weak interaction. Only then did one slowly recognize that the weak interaction force forms an independent field, perhaps on the same footing as the gravitational force, the electromagnetic force, and the strong nuclear and sub-nuclear forces.

  18. Propeller/wing interaction

    NASA Technical Reports Server (NTRS)

    Witkowski, David P.; Johnston, Robert T.; Sullivan, John P.

    1989-01-01

    The present experimental investigation of the steady-state and unsteady-state effects due to the interaction between a tractor propeller's wake and a wing employs, in the steady case, wind tunnel measurements at low subsonic speed; results are obtained which demonstrate wing performance response to variations in configuration geometry. Other steady-state results involve the propeller-hub lift and side-force due to the wing's influence on the propeller. The unsteady effects of interaction were studied through flow visualization of propeller-tip vortex distortion over a wing, again using a tractor-propeller configuration.

  19. Solar-terrestrial interactions

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The effects of solar radiation on man's environment are discussed. It is solar radiation that is the basic energy source driving the circulations of the earth's atmosphere and oceans. Solar radiation is responsible for the ionization of the earth's upper atmosphere to form the ionosphere, which is important to our understanding of the magnetosphere and its interaction with the solar wind. The solar wind, which is the continuous (but not steady) flow of the sun's coronal plasma and magnetic field into interplanetary space, plays both an active and passive role in its interaction with the earth's environment.

  20. The new interactive CESAR

    SciTech Connect

    Fox, P.B.; Yatabe, M.

    1987-01-01

    In this report the Nuclear Criticality Safety Analytical Methods Resource Center describes a new interactive version of CESAR, a critical experiments storage and retrieval program available on the Nuclear Criticality Information System (NCIS) database at Lawrence Livermore National Laboratory. The original version of CESAR did not include interactive search capabilities. The CESAR database was developed to provide a convenient, readily accessible means of storing and retrieving code input data for the SCALE Criticality Safety Analytical Sequences and the codes comprising those sequences. The database includes data for both cross section preparation and criticality safety calculations. 3 refs., 1 tab.

  1. Electronically Enhanced Classroom Interaction.

    ERIC Educational Resources Information Center

    Draper, Stephen; Cargill, Julie; Cutts, Quintin

    A design rationale for introducing electronic equipment (a group response system) for student interaction in lecture theaters is presented, linking the instructional design to theory. The effectiveness of the equipment for learning depends mostly on what pedagogic method is employed. Various alternative types are introduced, including: assessment;…

  2. Interactive Tabletops in Education

    ERIC Educational Resources Information Center

    Dillenbourg, Pierre; Evans, Michael

    2011-01-01

    Interactive tabletops are gaining increased attention from CSCL researchers. This paper analyses the relation between this technology and teaching and learning processes. At a global level, one could argue that tabletops convey a socio-constructivist flavor: they support small teams that solve problems by exploring multiple solutions. The…

  3. Teaching with Interactive Multimedia.

    ERIC Educational Resources Information Center

    Hudson, Tim

    Based on the idea that anyone who is interested in making entertaining and informative presentations in educational settings is interested in multimedia, this practical guide offers tips for communication (and other) teachers who want to integrate and program interactive multimedia into their courses. The guide suggests that teachers on limited…

  4. Teleconferencing and Interactive Media.

    ERIC Educational Resources Information Center

    Parker, Lorne A., Comp.; Olgren, Christine H., Comp.

    This publication contains more than 50 papers on the latest developments and applications of interactive media to link distant locations. The contributors, who represent business, government, education, medical, and telecommunications organizations in the United States, Canada, England, and Australia, have had direct experience with the full range…

  5. Designing Interactive Learning Systems.

    ERIC Educational Resources Information Center

    Barker, Philip

    1990-01-01

    Describes multimedia, computer-based interactive learning systems that support various forms of individualized study. Highlights include design models; user interfaces; design guidelines; media utilization paradigms, including hypermedia and learner-controlled models; metaphors and myths; authoring tools; optical media; workstations; four case…

  6. Interactive Genetics Tutorial Project.

    ERIC Educational Resources Information Center

    Wisconsin Univ., Madison. Dept. of Curriculum and Instruction.

    The Interactive Genetics Tutorial (IGT) project and the Intelligent Tutoring System for the IGT project named MENDEL supplement genetics instruction in biology courses by providing students with experience in designing, conducting, and evaluating genetics experiments. The MENDEL software is designed to: (1) simulate genetics experiments that…

  7. Interactive shape metamorphosis

    NASA Technical Reports Server (NTRS)

    Chen, David T.; State, Andrei; Banks, David

    1994-01-01

    A technique for controlled metamorphosis between surfaces in 3-space is described. Well-understood techniques to produce shape metamorphosis between models in a 2D parametric space is applied. The user selects morphable features interactively, and the morphing process executes in real time on a high-performance graphics multicomputer.

  8. Latent Variable Interaction Modeling.

    ERIC Educational Resources Information Center

    Schumacker, Randall E.

    2002-01-01

    Used simulation to study two different approaches to latent variable interaction modeling with continuous observed variables: (1) a LISREL 8.30 program and (2) data analysis through PRELIS2 and SIMPLIS programs. Results show that parameter estimation was similar but standard errors were different. Discusses differences in ease of implementation.…

  9. Interaction Information Retrieval.

    ERIC Educational Resources Information Center

    Dominich, Sandor

    1994-01-01

    Discussion of information retrieval focuses on an Interaction Information Retrieval model in which documents are interconnected; queries and documents are treated in the same way; and retrieval is the result of the interconnection between query and documents. A theoretical mathematical formulation of this type of retrieval is given. (Contains 31…

  10. Interactive Mold House Tour

    EPA Pesticide Factsheets

    Get a quick glimpse of some of the most important ways to protect your home from mold by this interactive tour of the Mold House. Room-by-room, you'll learn about common mold issues and how to address them.

  11. Dimensions of Group Interaction

    ERIC Educational Resources Information Center

    Dawidowicz, Paula

    2008-01-01

    The correlation between positive and negative group interactions and one or another of individuals' attitudes or characteristics--moral development, critical thinking, resilience, and self efficacy--has been examined previously. However, no systemic examination of individuals' development of patterns of these characteristics and those patterns'…

  12. Connectionist Interaction Information Retrieval.

    ERIC Educational Resources Information Center

    Dominich, Sandor

    2003-01-01

    Discussion of connectionist views for adaptive clustering in information retrieval focuses on a connectionist clustering technique and activation spreading-based information retrieval model using the interaction information retrieval method. Presents theoretical as well as simulation results as regards computational complexity and includes…

  13. Magnetosphere-ionosphere interactions

    NASA Technical Reports Server (NTRS)

    Vondrak, R. R.; Chiu, Y. T.; Evans, D. S.; Patterson, V. G.; Romick, G. J.; Stasiewicz, K.

    1979-01-01

    The present understanding of magnetosphere ionosphere interactions is described, and present and future predictive capabilities are assessed. Ionospheric features directly coupled to the magnetosphere to a significant degree are considered, with emphasis given to those phenomena of major interest to forecasters and users.

  14. Data Interactive Publications Revisited

    NASA Astrophysics Data System (ADS)

    Domenico, B.; Weber, W. J.

    2011-12-01

    A few years back, the authors presented examples of online documents that allowed the reader to interact directly with datasets, but there were limitations that restricted the interaction to specific desktop analysis and display tools that were not generally available to all readers of the documents. Recent advances in web service technology and related standards are making it possible to develop systems for publishing online documents that enable readers to access, analyze, and display the data discussed in the publication from the perspective and in the manner from which the author wants it to be represented. By clicking on embedded links, the reader accesses not only the usual textual information in a publication, but also data residing on a local or remote web server as well as a set of processing tools for analyzing and displaying the data. With the option of having the analysis and display processing provided on the server, there are now a broader set of possibilities on the client side where the reader can interact with the data via a thin web client, a rich desktop application, or a mobile platform "app." The presentation will outline the architecture of data interactive publications along with illustrative examples.

  15. Data Interactive Publications

    NASA Astrophysics Data System (ADS)

    Domenico, B.; Weber, J.

    2012-04-01

    For some years now, the authors have developed examples of online documents that allowed the reader to interact directly with datasets, but there were limitations that restricted the interaction to specific desktop analysis and display tools that were not generally available to all readers of the documents. Recent advances in web service technology and related standards are making it possible to develop systems for publishing online documents that enable readers to access, analyze, and display the data discussed in the publication from the perspective and in the manner from which the author wants it to be represented. By clicking on embedded links, the reader accesses not only the usual textual information in a publication, but also data residing on a local or remote web server as well as a set of processing tools for analyzing and displaying the data. With the option of having the analysis and display processing provided on the server (or in the cloud), there are now a broader set of possibilities on the client side where the reader can interact with the data via a thin web client, a rich desktop application, or a mobile platform "app." The presentation will outline the architecture of data interactive publications along with illustrative examples.

  16. Interaction, 1996-1997.

    ERIC Educational Resources Information Center

    Hajdu-Vaughn, Susan, Ed.; Coyle, Barbara, Ed.

    1997-01-01

    This collection includes four quarterly issues of "Interaction," a publication of the Canadian Child Care Federation. Each issue addresses several topics and is arranged in four sections: opinions, practice/pratique, focus/a propos, and news/nouvelles. The opinions section includes letters and editorial/review columns, the practice…

  17. GENIE final state interactions

    SciTech Connect

    Dytman, Steven

    2015-10-15

    Final state interactions are an important component of any neutrino-nucleus Monte Carlo program. GENIE has 2 FSI programs which serve different purposes. Each has fair-good agreement with a wide range of hadron-nucleus data. Recent improvements and planned advancements are described.

  18. Interactions of cosmic superstrings

    SciTech Connect

    Jackson, Mark G.; /Fermilab

    2007-06-01

    We develop methods by which cosmic superstring interactions can be studied in detail. These include the reconnection probability and emission of radiation such as gravitons or small string loops. Loop corrections to these are discussed, as well as relationships to (p; q)-strings. These tools should allow a phenomenological study of string models in anticipation of upcoming experiments sensitive to cosmic string radiation.

  19. Interactive Technology for Education.

    ERIC Educational Resources Information Center

    Brooks, Robert; Perl, Barry

    1991-01-01

    By using the kind of two-way television system envisioned by Buckminster Fuller, school children can learn at their own rates and select interesting topics, thereby continually reinforcing the desire to learn. Today's new interactive video systems, from multimedia encyclopedias to hypermedia combinations, allow students to explore subject matter…

  20. Electron interaction in matter

    NASA Technical Reports Server (NTRS)

    Dance, W. E.; Rainwater, W. J.; Rester, D. H.

    1969-01-01

    Data on the scattering of 1-MeV electrons in aluminum for the case of non-normal incidence, electron-bremsstrahlung cross-sections in thin targets, and the production of bremstrahlung by electron interaction in thick targets, are presented both in tabular and graphic form. These results may interest physicists and radiologists.

  1. Standardizing Interaction Design Education

    ERIC Educational Resources Information Center

    Thomassen, Aukje; Ozcan, Oguzhan

    2010-01-01

    The objective of this paper is to which extend the didactic format of studio-based group-work is applicable for creating a common-ground for Interaction Design Education in European Perspective. The current debate on design education shows us a landscape of different initiatives. So far difficulties have arisen in the area of accreditation and…

  2. Interactive Reflective Logs

    ERIC Educational Resources Information Center

    Deaton, Cynthia Minchew; Deaton, Benjamin E.; Leland, Katina

    2010-01-01

    The authors created an interactive reflective log (IRL) to provide teachers with an opportunity to use a journal approach to record, evaluate, and communicate student understanding of science concepts. Unlike a traditional journal, the IRL incorporates prompts to encourage students to discuss their understanding of science content and science…

  3. Embarrassment in Dyadic Interaction.

    ERIC Educational Resources Information Center

    Edelmann, Robert J.; Hampson, Sarah E.

    1981-01-01

    Subject pairs (N=18) participated in an alternating question-and-answer session at one of two interactional distances utilizing questions which increased in their intimacy content. Results indicated topic intimacy, but not distance, affected the embarrassment potential of the situation. Increases in embarrassment caused changes in nonverbal and…

  4. Tetrel Bonding Interactions.

    PubMed

    Bauzá, Antonio; Mooibroek, Tiddo J; Frontera, Antonio

    2016-02-01

    Tetrel (Tr) bonding is first placed into perspective as a σ-hole bonding interaction with atoms of the Tr family. An sp(3) R4Tr unit has four σ-holes with which a Lewis base can form a complex. We then highlight some inspiring crystal structures where Tr bonding is obvious, followed by an account of our own work. We have shown that Tr bonding is ubiquitous in the solid state and we have highlighted that Tr bonding with carbon is possible when C is placed in the appropriate chemical context. We hope that this account serves as an initial guide and source of inspiration for others wishing to exploit this vastly underexplored interaction.

  5. Interactive design center.

    SciTech Connect

    Pomplun, Alan R. (Sandia National Laboratories, Livermore, CA)

    2005-07-01

    Sandia's advanced computing resources provide researchers, engineers and analysts with the ability to develop and render highly detailed large-scale models and simulations. To take full advantage of these multi-million data point visualizations, display systems with comparable pixel counts are needed. The Interactive Design Center (IDC) is a second generation visualization theater designed to meet this need. The main display integrates twenty-seven projectors in a 9-wide by 3-high array with a total display resolution of more than 35 million pixels. Six individual SmartBoard displays offer interactive capabilities that include on-screen annotation and touch panel control of the facility's display systems. This report details the design, implementation and operation of this innovative facility.

  6. Neutrinophilic nonstandard interactions

    NASA Astrophysics Data System (ADS)

    Farzan, Yasaman; Heeck, Julian

    2016-09-01

    We construct UV-complete models for nonstandard neutrino interactions mediated by a sub-GeV gauge boson Z' coupled to baryon number B or B -L . A flavor-dependent Z' coupling to neutrinos is induced by mixing a U (1 )'-charged Dirac fermion with the active neutrinos, naturally suppressing flavor violation or nonuniversality of the charged leptons to the loop level. We show that these models can give rise to large flavor-conserving as well as flavor-violating nonstandard neutral-current neutrino interactions potentially observable in current or future oscillation experiments such as DUNE without being in conflict with other constraints such as neutrino scattering or lepton-flavor-violating decays. In particular, the LMA-Dark solution to the solar-neutrino anomaly can be obtained for U (1 )B, but not for U (1 )B-L.

  7. Combustor diffuser interaction program

    NASA Technical Reports Server (NTRS)

    Srinivasan, Ram; Thorp, Daniel

    1986-01-01

    Advances in gas turbine engine performance are achieved by using compressor systems with high stage loading and low part count, which result in high exit Mach numbers. The diffuser and combustor systems in such engines should be optimized to reduce system pressure loss and to maximize the engine thrust-to-weight ratio and minimize length. The state-of-the-art combustor-diffuser systems do not meet these requirements. Detailed understanding of the combustor-diffuser flow field interaction is required for designing advanced gas turbine engines. An experimental study of the combustor-diffuser interaction (CDI) is being conducted to obtain data for the evaluation and improvement of analytical models applicable to a wide variety of diffuser designs. The CDI program consists of four technical phases: Literature Search; Baseline Configuration; Parametric Configurations; and Performance Configurations. Phase 2 of the program is in progress.

  8. Interactive optical panel

    DOEpatents

    Veligdan, J.T.

    1995-10-03

    An interactive optical panel assembly includes an optical panel having a plurality of ribbon optical waveguides stacked together with opposite ends thereof defining panel first and second faces. A light source provides an image beam to the panel first face for being channeled through the waveguides and emitted from the panel second face in the form of a viewable light image. A remote device produces a response beam over a discrete selection area of the panel second face for being channeled through at least one of the waveguides toward the panel first face. A light sensor is disposed across a plurality of the waveguides for detecting the response beam therein for providing interactive capability. 10 figs.

  9. Evolution of intrafamilial interactions.

    PubMed Central

    Lynch, M

    1987-01-01

    A theory for the evolution of behavioral interactions among relatives is developed that allows for genetic correlations between the types of behavior that are expressed in different social contexts. Both theoretical and empirical considerations indicate that such genetic constraints will almost certainly be common in natural populations. It is shown that when genetic correlations between elements of social behavior exist, Hamilton's rule inaccurately describes the conditions for evolution by way of kin selection. The direction in which social organization evolves is a delicate function of the genetic covariance structure among behaviors expressed as an offspring, sibling, parent, etc. A change in this covariance structure caused by random genetic drift or by a change in environment for a population exhibiting genotype-environment interaction can cause the population to suddenly cross a threshold into a new selective domain. Consequently, radical changes in social organization may arise between closely related species without any major shift in selective pressures external to the population. Images PMID:3479804

  10. Volcanism-Climate Interactions

    NASA Technical Reports Server (NTRS)

    Walter, Louis S. (Editor); Desilva, Shanaka (Editor)

    1991-01-01

    The range of disciplines in the study of volcanism-climate interactions includes paleoclimate, volcanology, petrology, tectonics, cloud physics and chemistry, and climate and radiation modeling. Questions encountered in understanding the interactions include: the source and evolution of sulfur and sulfur-gaseous species in magmas; their entrainment in volcanic plumes and injection into the stratosphere; their dissipation rates; and their radiative effects. Other issues include modeling and measuring regional and global effects of such large, dense clouds. A broad-range plan of research designed to answer these questions was defined. The plan includes observations of volcanoes, rocks, trees, and ice cores, as well as satellite and aircraft observations of erupting volcanoes and resulting lumes and clouds.

  11. Interactive optical panel

    DOEpatents

    Veligdan, James T.

    1995-10-03

    An interactive optical panel assembly 34 includes an optical panel 10 having a plurality of ribbon optical waveguides 12 stacked together with opposite ends thereof defining panel first and second faces 16, 18. A light source 20 provides an image beam 22 to the panel first face 16 for being channeled through the waveguides 12 and emitted from the panel second face 18 in the form of a viewable light image 24a. A remote device 38 produces a response beam 40 over a discrete selection area 36 of the panel second face 18 for being channeled through at least one of the waveguides 12 toward the panel first face 16. A light sensor 42,50 is disposed across a plurality of the waveguides 12 for detecting the response beam 40 therein for providing interactive capability.

  12. Interactive chemical reactivity exploration.

    PubMed

    Haag, Moritz P; Vaucher, Alain C; Bosson, Maël; Redon, Stéphane; Reiher, Markus

    2014-10-20

    Elucidating chemical reactivity in complex molecular assemblies of a few hundred atoms is, despite the remarkable progress in quantum chemistry, still a major challenge. Black-box search methods to find intermediates and transition-state structures might fail in such situations because of the high-dimensionality of the potential energy surface. Here, we propose the concept of interactive chemical reactivity exploration to effectively introduce the chemist's intuition into the search process. We employ a haptic pointer device with force feedback to allow the operator the direct manipulation of structures in three dimensions along with simultaneous perception of the quantum mechanical response upon structure modification as forces. We elaborate on the details of how such an interactive exploration should proceed and which technical difficulties need to be overcome. All reactivity-exploration concepts developed for this purpose have been implemented in the samson programming environment.

  13. Interactive protein manipulation

    SciTech Connect

    SNCrivelli@lbl.gov

    2003-07-01

    We describe an interactive visualization and modeling program for the creation of protein structures ''from scratch''. The input to our program is an amino acid sequence -decoded from a gene- and a sequence of predicted secondary structure types for each amino acid-provided by external structure prediction programs. Our program can be used in the set-up phase of a protein structure prediction process; the structures created with it serve as input for a subsequent global internal energy minimization, or another method of protein structure prediction. Our program supports basic visualization methods for protein structures, interactive manipulation based on inverse kinematics, and visualization guides to aid a user in creating ''good'' initial structures.

  14. The interactive videodisc.

    PubMed

    Leveridge, L L

    1983-04-01

    Dynamic audiovisual presentations that are interactive due to the use of videodisc systems provide more efficient and effective communication of those elements of medicine best learned by seeing them, than is possible via traditional modes. This is particularly true when externally interfaced electronic data processors are used to automate the process. While magnetic and stylus-type videodisc players can serve in education, it is the optical videodisc that has the greatest educational potential. The AMA has been exploring the capabilities of optical videodisc systems and demonstrating pilot programs that use good principles of audiovisual and computer-assisted instruction in tutorial formats or presented as patient management problems. We are on the threshold of a revolution in communication potentially as significant to education as the one which followed the invention of movable type. Using interactive videodisc programs, designed and produced with skill and care, we can solve some of medical education's most pressing problems.

  15. Interactive digital signal processor

    NASA Technical Reports Server (NTRS)

    Mish, W. H.; Wenger, R. M.; Behannon, K. W.; Byrnes, J. B.

    1982-01-01

    The Interactive Digital Signal Processor (IDSP) is examined. It consists of a set of time series analysis Operators each of which operates on an input file to produce an output file. The operators can be executed in any order that makes sense and recursively, if desired. The operators are the various algorithms used in digital time series analysis work. User written operators can be easily interfaced to the sysatem. The system can be operated both interactively and in batch mode. In IDSP a file can consist of up to n (currently n=8) simultaneous time series. IDSP currently includes over thirty standard operators that range from Fourier transform operations, design and application of digital filters, eigenvalue analysis, to operators that provide graphical output, allow batch operation, editing and display information.

  16. Acousto-Optic Interactions.

    DTIC Science & Technology

    The document reports the results of the experimental and theoretical investigation of acousto - optic interactions in guided wave structure for optical...waves and acoustic surface waves and experimental results of isotropic and anisotropic diffraction in LiNbO3 and quartz. A simple acousto - optic plate...CVD ZnO films on sapphire, which may be needed for the acousto - optic devices in thin films are also included. (Author)

  17. Mesoscale/convective interaction

    NASA Technical Reports Server (NTRS)

    Haines, P. A.; Sun, W. Y.

    1988-01-01

    A novel cumulus parameterization scheme (CPS) has been developed in order to account for mesoscale/convective-scale interaction which considers both the mesoscale and convective scale mass and moisture budgets, under the assumption that the heating rate is a maximum for given environmental conditions. The basis of the CPS is a detailed, quasi-one-dimensional cloud model that calculates mass and moisture fluxes similar to those calculated by the Schlesinger (1978) three-dimensional model.

  18. Interacting warm dark matter

    SciTech Connect

    Cruz, Norman; Palma, Guillermo; Zambrano, David; Avelino, Arturo E-mail: guillermo.palma@usach.cl E-mail: avelino@fisica.ugto.mx

    2013-05-01

    We explore a cosmological model composed by a dark matter fluid interacting with a dark energy fluid. The interaction term has the non-linear λρ{sub m}{sup α}ρ{sub e}{sup β} form, where ρ{sub m} and ρ{sub e} are the energy densities of the dark matter and dark energy, respectively. The parameters α and β are in principle not constrained to take any particular values, and were estimated from observations. We perform an analytical study of the evolution equations, finding the fixed points and their stability properties in order to characterize suitable physical regions in the phase space of the dark matter and dark energy densities. The constants (λ,α,β) as well as w{sub m} and w{sub e} of the EoS of dark matter and dark energy respectively, were estimated using the cosmological observations of the type Ia supernovae and the Hubble expansion rate H(z) data sets. We find that the best estimated values for the free parameters of the model correspond to a warm dark matter interacting with a phantom dark energy component, with a well goodness-of-fit to data. However, using the Bayesian Information Criterion (BIC) we find that this model is overcame by a warm dark matter – phantom dark energy model without interaction, as well as by the ΛCDM model. We find also a large dispersion on the best estimated values of the (λ,α,β) parameters, so even if we are not able to set strong constraints on their values, given the goodness-of-fit to data of the model, we find that a large variety of theirs values are well compatible with the observational data used.

  19. ELEMENTARY PARTICLE INTERACTIONS

    SciTech Connect

    EFREMENKO, YURI; HANDLER, THOMAS; KAMYSHKOV, YURI; SIOPSIS, GEORGE; SPANIER, STEFAN

    2013-07-30

    The High-Energy Elementary Particle Interactions group at UT during the last three years worked on the following directions and projects: Collider-based Particle Physics; Neutrino Physics, particularly participation in “NOνA”, “Double Chooz”, and “KamLAND” neutrino experiments; and Theory, including Scattering amplitudes, Quark-gluon plasma; Holographic cosmology; Holographic superconductors; Charge density waves; Striped superconductors; and Holographic FFLO states.

  20. [Brain-gut interactions].

    PubMed

    Bonaz, B

    2010-08-01

    Our digestive tract has an autonomous functioning but also has a bidirectional relation with our brain known as brain-gut interactions. This communication is mediated by the autonomous nervous system, i.e., the sympathetic and parasympathetic nervous systems, with a mixed afferent and efferent component, and the circumventricular organs located outside the blood-brain barrier. The vagus nerve, known as the principal component of the parasympathetic nervous system, is a mixed nerve composed of 90% afferent fibers, which has physiological roles due to its putative vegetative functions. The vagus nerve has also anti-inflammatory properties both through the hypothalamic pituitary adrenal axis (through its afferents) and the cholinergic anti-inflammatory pathway (through its efferents). The sympathetic nervous system has a classical antagonist effect on the parasympathetic nervous system at the origin of an equilibrated sympathovagal balance in normal conditions. The brain is able to integrate inputs coming from the digestive tract inside a central autonomic network organized around the hypothalamus, limbic system and cerebral cortex (insula, prefrontal, cingulate) and in return to modify the autonomic nervous system and the hypothalamic pituitary adrenal axis in the frame of physiological loops. A dysfunction of these brain-gut interactions, favoured by stress, is most likely involved in the pathophysiology of digestive diseases such as irritable bowel syndrome or even inflammatory bowel diseases. A better knowledge of these brain-gut interactions has therapeutic implications in the domain of pharmacology, neurophysiology, behavioural and cognitive management.

  1. Transactional interactive multimedia banner

    NASA Astrophysics Data System (ADS)

    Shae, Zon-Yin; Wang, Xiping; von Kaenel, Juerg

    2000-05-01

    Advertising in TV broadcasting has shown that multimedia is a very effective means to present merchandise and attract shoppers. This has been applied to the Web by including animated multimedia banner ads on web pages. However, the issues of coupling interactive browsing, shopping, and secure transactions e.g. from inside a multimedia banner, have only recently started to being explored. Currently there is an explosively growing amount of back-end services available (e.g., business to business commerce (B2B), business to consumer (B2C) commerce, and infomercial services) in the Internet. These services are mostly accessible through static HTML web pages at a few specific web portals. In this paper, we will investigate the feasibility of using interactive multimedia banners as pervasive access point for the B2C, B2B, and infomercial services. We present a system architecture that involves a layer of middleware agents functioning as the bridge between the interactive multimedia banners and back-end services.

  2. Bacteria-surface interactions.

    PubMed

    Tuson, Hannah H; Weibel, Douglas B

    2013-05-14

    The interaction of bacteria with surfaces has important implications in a range of areas, including bioenergy, biofouling, biofilm formation, and the infection of plants and animals. Many of the interactions of bacteria with surfaces produce changes in the expression of genes that influence cell morphology and behavior, including genes essential for motility and surface attachment. Despite the attention that these phenotypes have garnered, the bacterial systems used for sensing and responding to surfaces are still not well understood. An understanding of these mechanisms will guide the development of new classes of materials that inhibit and promote cell growth, and complement studies of the physiology of bacteria in contact with surfaces. Recent studies from a range of fields in science and engineering are poised to guide future investigations in this area. This review summarizes recent studies on bacteria-surface interactions, discusses mechanisms of surface sensing and consequences of cell attachment, provides an overview of surfaces that have been used in bacterial studies, and highlights unanswered questions in this field.

  3. Interactive reservoir simulation

    SciTech Connect

    Regtien, J.M.M. Por, G.J.A.; Stiphout, M.T. van; Vlugt, F.F. van der

    1995-12-31

    Shell`s new Modular Reservoir Simulator (MoReS) has been equipped with a comprehensive and versatile user interface called FrontEnd. Apart from providing a user-friendly environment for interactive reservoir simulation, FrontEnd serves a software platform for other dynamic simulation and reservoir-engineering applications. It offers to all supported applications a common user interface, enables the re-use of code and reduces overall maintenance and support costs associated with the embedded applications. Because of its features, FrontEnd facilitates the transfer of research results in the form of operational software to end users. When coupled with MoReS, FrontEnd can be used for pre- and post-processing and interactive simulation. The pre-processing options allow data to be inputted by means of various OSF/Motif widgets containing a spreadsheet, text editors, dialogues and graphical input. The display of the input data as well as the post-processing of all simulation results is made possible by a variety of user-defined plot of tabular (e.g. timestep summary) and array (simulation grid) data. During a simulation user-defined plots can be displayed and edited, allowing a close inspection of the results as they are being calculated. FrontEnd has been equipped with a powerful input command language, which gives the batch user as much flexibility and control over the input as the interactive user.

  4. Pharmacological interactions of vasoconstrictors.

    PubMed

    Gómez-Moreno, Gerardo; Guardia, Javier; Cutando, Antonio; Calvo-Guirado, José Luis

    2009-01-01

    This article is the first of a series on pharmacological interactions involving medicaments commonly prescribed and/or used in odontology: vasoconstrictors in local anaesthetics and anti-inflammatory and anti-microbial analgesics. The necessity for the odontologist to be aware of adverse reactions as a result of the pharmacological interactions is due to the increase in medicament consumption by the general population. There is a demographic change with greater life expectancy and patients have increased chronic health problems and therefore have increased medicament intake. The presence of adrenaline (epinephrine) and other vasoconstrictors in local odontological anaesthetics is beneficial in relation to the duration and depth of anaesthesia and reduces bleeding and systemic toxicity of the local anaesthetic. However, it might produce pharmacological interactions between the injected vasoconstrictors and the local anaesthetic and adrenergic medicament administered exogenically which the odontologist should be aware of, especially because of the risk of consequent adverse reactions. Therefore the importance of conducting a detailed clinical history of the general state of health and include all medicaments, legal as well as illegal, taken by the patient.

  5. Biomolecular Interaction Assay

    SciTech Connect

    Bruckner-Lea, Cindy J.; Brown, L; Holman, David A.; Olson, Lydia; Grate, Jay W.

    2000-12-29

    Understanding the binding interactions of complexes of multiple proteins is an important area of medical research since many biological signaling pathways involve multiple protein complexes. A number of sensor technologies have been adapted to monitoring biomolecular interactions. Acoustic wave devices such as flexural plate wave devices, surface transverse waves, and quartz crystal microbalances detect the mass increase observed upon binding of a solution biomolecule to a surface bound biomolecule. However, these devices will also respond to changes in viscosity, temperature, liquid density, and viscoelastic effects, which may confound the interpretation of observed signals. Nonspecific binding is indistinguishable from specific binding. Several techniques for refractive index sensing, such as planar wave guides and surface plasmon resonance (SPR), can also be used to observe biomolecular interactions localized at a surface. Again, nonspecific binding is indistinguishable from specific binding. In addition, the derivatized surface must be very thin and uniform to obtain adequate sensitivity and reproducibility, and the technique is not suited for monitoring large multiple protein complexes since the measurement sensitivity decreases rapidly with distance from the sensor surface. All of these techniques use planar surfaces that are difficult to prepare and characterize, and must be prepared fresh for each assay.

  6. Bacteria-surface interactions

    PubMed Central

    Tuson, Hannah H.; Weibel, Douglas B.

    2013-01-01

    The interaction of bacteria with surfaces has important implications in a range of areas, including bioenergy, biofouling, biofilm formation, and the infection of plants and animals. Many of the interactions of bacteria with surfaces produce changes in the expression of genes that influence cell morphology and behavior, including genes essential for motility and surface attachment. Despite the attention that these phenotypes have garnered, the bacterial systems used for sensing and responding to surfaces are still not well understood. An understanding of these mechanisms will guide the development of new classes of materials that inhibit and promote cell growth, and complement studies of the physiology of bacteria in contact with surfaces. Recent studies from a range of fields in science and engineering are poised to guide future investigations in this area. This review summarizes recent studies on bacteria-surface interactions, discusses mechanisms of surface sensing and consequences of cell attachment, provides an overview of surfaces that have been used in bacterial studies, and highlights unanswered questions in this field. PMID:23930134

  7. Weakly nonlinear magnetohydrodynamic wave interactions

    SciTech Connect

    Webb, G.M.; Brio, M.; Kruse, M.T.; Zank, G.P.

    1999-06-01

    Equations describing weakly nonlinear magnetohydrodynamic (MHD) wave interactions in one Cartesian space dimension are discussed. For wave propagation in uniform media, the wave interactions of interest consist of: (a) three-wave resonant interactions in which high frequency waves, may evolve on long space and time scales if the wave phases satisfy the resonance conditions; (b) Burgers self-wave steepening for the magnetoacoustic waves, and (c) mean wave field effects, in which a particular wave interacts with the mean wave field of the other waves. For wave propagation in non-uniform media, further linear wave mixing terms appear in the equations. The equations describe four types of resonant triads: slow-fast magnetosonic wave interaction; Alfv{acute e}n-entropy wave interaction; Alfv{acute e}n-magnetosonic wave interaction; and magnetosonic-entropy wave interaction. The formalism is restricted to coherent wave interactions. {copyright} {ital 1999 American Institute of Physics.}

  8. Interactive Learning and "Clickers"

    NASA Astrophysics Data System (ADS)

    Rudolph, Alexander

    2006-12-01

    A growing body of evidence demonstrates that student understanding and retention of key concepts in science can be dramatically improved by using “Interactive Learning” techniques. Interactive learning is a way to get students more actively involved in their own learning than by simple lecture alone. I will focus on one type of interactive learning activity, known as “Think-Pair-Share”. After a brief (10-20 minute) lecture on a topic, students are asked a conceptually challenging multiple-choice question. After they answer, if there is sufficient disagreement, the students discuss the question in small groups after which they answer the same question again. Frequently, the percentage of correct answers goes up, indicating that the active role of speaking and listening, together with peer instruction, has helped students better grasp the concept being tested. If disagreement persists, or if students continue to have questions, a short, class-wide discussion can be held. Clickers provide an excellent means to collect students’ answers to “Think-Pair-Share” questions in real time. Although clickers are not essential, they do provide some advantages over alternatives such as flash cards: answers are completely anonymous (though you as instructor can record individual responses); you can display a histogram of results immediately, either before or after group discussion, providing immediate feedback; by recording the results, you can give students credit for their participation in class. In this talk, I will model “Think-Pair-Share” with the audience using clickers, show results from my classes before and after group discussions, share results of a student survey on “Think-Pair-Share” and clickers, describe other uses of clickers (e.g., taking attendance, surveys, test administration) and highlight some of the pros and cons of clickers v. flashcards.

  9. Intelligently interactive combat simulation

    NASA Astrophysics Data System (ADS)

    Fogel, Lawrence J.; Porto, Vincent W.; Alexander, Steven M.

    2001-09-01

    To be fully effective, combat simulation must include an intelligently interactive enemy... one that can be calibrated. But human operated combat simulations are uncalibratable, for we learn during the engagement, there's no average enemy, and we cannot replicate their culture/personality. Rule-based combat simulations (expert systems) are not interactive. They do not take advantage of unexpected mistakes, learn, innovate, and reflect the changing mission/situation. And it is presumed that the enemy does not have a copy of the rules, that the available experts are good enough, that they know why they did what they did, that their combat experience provides a sufficient sample and that we know how to combine the rules offered by differing experts. Indeed, expert systems become increasingly complex, costly to develop, and brittle. They have face validity but may be misleading. In contrast, intelligently interactive combat simulation is purpose- driven. Each player is given a well-defined mission, reference to the available weapons/platforms, their dynamics, and the sensed environment. Optimal tactics are discovered online and in real-time by simulating phenotypic evolution in fast time. The initial behaviors are generated randomly or include hints. The process then learns without instruction. The Valuated State Space Approach provides a convenient way to represent any purpose/mission. Evolutionary programming searches the domain of possible tactics in a highly efficient manner. Coupled together, these provide a basis for cruise missile mission planning, and for driving tank warfare simulation. This approach is now being explored to benefit Air Force simulations by a shell that can enhance the original simulation.

  10. Visuo-Vestibular Interactions

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Session TA3 includes short reports covering: (1) Vestibulo-Oculomotor Interaction in Long-Term Microgravity; (2) Effects of Weightlessness on the Spatial Orientation of Visually Induced Eye Movements; (3) Adaptive Modification of the Three-Dimensional Vestibulo-Ocular Reflex during Prolonged Microgravity; (4) The Dynamic Change of Brain Potential Related to Selective Attention to Visual Signals from Left and Right Visual Fields; (5) Locomotor Errors Caused by Vestibular Suppression; and (6) A Novel, Image-Based Technique for Three-Dimensional Eye Measurement.

  11. Interactive Classification Technology

    NASA Technical Reports Server (NTRS)

    deBessonet, Cary

    2000-01-01

    The investigators upgraded a knowledge representation language called SL (Symbolic Language) and an automated reasoning system called SMS (Symbolic Manipulation System) to enable the more effective use of the technologies in automated reasoning and interactive classification systems. The overall goals of the project were: 1) the enhancement of the representation language SL to accommodate a wider range of meaning; 2) the development of a default inference scheme to operate over SL notation as it is encoded; and 3) the development of an interpreter for SL that would handle representations of some basic cognitive acts and perspectives.

  12. Human Computer Interaction

    NASA Astrophysics Data System (ADS)

    Bhagwani, Akhilesh; Sengar, Chitransh; Talwaniper, Jyotsna; Sharma, Shaan

    2012-08-01

    The paper basically deals with the study of HCI (Human computer interaction) or BCI(Brain-Computer-Interfaces) Technology that can be used for capturing brain signals and translating them into commands that allow humans to control (just by thinking) devices such as computers, robots, rehabilitation technology and virtual reality environments. The HCI is based as a direct communication pathway between the brain and an external device. BCIs are often aimed at assisting, augmenting, or repairing human cognitive or sensory-motor functions.The paper also deals with many advantages of BCI Technology along with some of its applications and some major drawbacks.

  13. Detection of molecular interactions

    DOEpatents

    Groves, John T [Berkeley, CA; Baksh, Michael M [Fremont, CA; Jaros, Michal [Brno, CH

    2012-02-14

    A method and assay are described for measuring the interaction between a ligand and an analyte. The assay can include a suspension of colloidal particles that are associated with a ligand of interest. The colloidal particles are maintained in the suspension at or near a phase transition state from a condensed phase to a dispersed phase. An analyte to be tested is then added to the suspension. If the analyte binds to the ligand, a phase change occurs to indicate that the binding was successful.

  14. Flank solar wind interaction

    NASA Technical Reports Server (NTRS)

    Moses, Stewart L.; Greenstadt, Eugene W.

    1992-01-01

    This report summarizes the results of the first 12 months of our program to study the interaction of the Earth's magnetosphere with the solar wind on the far flanks of the bow shock. This study employs data from the ISEE-3 spacecraft during its traversals of the Earth's magnetotail and correlative data from spacecraft monitoring the solar wind upstream. Our main effort to date has involved assembling data sets and developing new plotting programs. Two talks were given at the Spring Meeting of the American Geophysical Union describing our initial results from analyzing data from the far flank foreshock and magnetosheath. The following sections summarize our results.

  15. Integrin Cytoplasmic Tail Interactions

    PubMed Central

    2015-01-01

    Integrins are heterodimeric cell surface adhesion receptors essential for multicellular life. They connect cells to the extracellular environment and transduce chemical and mechanical signals to and from the cell. Intracellular proteins that bind the integrin cytoplasmic tail regulate integrin engagement of extracellular ligands as well as integrin localization and trafficking. Cytoplasmic integrin-binding proteins also function downstream of integrins, mediating links to the cytoskeleton and to signaling cascades that impact cell motility, growth, and survival. Here, we review key integrin-interacting proteins and their roles in regulating integrin activity, localization, and signaling. PMID:24467163

  16. Bunyavirus-Vector Interactions

    PubMed Central

    Horne, Kate McElroy; Vanlandingham, Dana L.

    2014-01-01

    The Bunyaviridae family is comprised of more than 350 viruses, of which many within the Hantavirus, Orthobunyavirus, Nairovirus, Tospovirus, and Phlebovirus genera are significant human or agricultural pathogens. The viruses within the Orthobunyavirus, Nairovirus, and Phlebovirus genera are transmitted by hematophagous arthropods, such as mosquitoes, midges, flies, and ticks, and their associated arthropods not only serve as vectors but also as virus reservoirs in many cases. This review presents an overview of several important emerging or re-emerging bunyaviruses and describes what is known about bunyavirus-vector interactions based on epidemiological, ultrastructural, and genetic studies of members of this virus family. PMID:25402172

  17. Imitation, Interaction and Dialogue Using Intensive Interaction: Tea Party Rules

    ERIC Educational Resources Information Center

    Barber, Mark

    2007-01-01

    Intensive Interaction has become widely used when building up communication with children with profound learning difficulties. Often practitioners understand Intensive Interaction to be primarily about imitation and Mark Barber shows how this can be a "mis"understanding that limits the kinds of interactions that can be enjoyed by conversation…

  18. JSPAM: Interacting galaxies modeller

    NASA Astrophysics Data System (ADS)

    Wallin, John F.; Holincheck, Anthony; Harvey, Allen

    2015-11-01

    JSPAM models galaxy collisions using a restricted n-body approach to speed up computation. Instead of using a softened point-mass potential, the software supports a modified version of the three component potential created by Hernquist (1994, ApJS 86, 389). Although spherically symmetric gravitationally potentials and a Gaussian model for the bulge are used to increase computational efficiency, the potential mimics that of a fully consistent n-body model of a galaxy. Dynamical friction has been implemented in the code to improve the accuracy of close approaches between galaxies. Simulations using this code using thousands of particles over the typical interaction times of a galaxy interaction take a few seconds on modern desktop workstations, making it ideal for rapidly prototyping the dynamics of colliding galaxies. Extensive testing of the code has shown that it produces nearly identical tidal features to those from hierarchical tree codes such as Gadget but using a fraction of the computational resources. This code was used in the Galaxy Zoo: Mergers project and is very well suited for automated fitting of galaxy mergers with automated pattern fitting approaches such as genetic algorithms. Java and Fortran versions of the code are available.

  19. Incremental full configuration interaction

    NASA Astrophysics Data System (ADS)

    Zimmerman, Paul M.

    2017-03-01

    The incremental expansion provides a polynomial scaling method for computing electronic correlation energies. This article details a new algorithm and implementation for the incremental expansion of full configuration interaction (FCI), called iFCI. By dividing the problem into n-body interaction terms, accurate correlation energies can be recovered at low n in a highly parallel computation. Additionally, relatively low-cost approximations are possible in iFCI by solving for each incremental energy to within a specified threshold. Herein, systematic tests show that FCI-quality energies can be asymptotically reached for cases where dynamic correlation is dominant as well as where static correlation is vital. To further reduce computational costs and allow iFCI to reach larger systems, a select-CI approach (heat-bath CI) requiring two parameters is incorporated. Finally, iFCI provides the first estimate of FCI energies for hexatriene with a polarized double zeta basis set, which has 32 electrons correlated in 118 orbitals, corresponding to a FCI dimension of over 1038.

  20. Interactive Computer Graphics

    NASA Technical Reports Server (NTRS)

    Kenwright, David

    2000-01-01

    Aerospace data analysis tools that significantly reduce the time and effort needed to analyze large-scale computational fluid dynamics simulations have emerged this year. The current approach for most postprocessing and visualization work is to explore the 3D flow simulations with one of a dozen or so interactive tools. While effective for analyzing small data sets, this approach becomes extremely time consuming when working with data sets larger than one gigabyte. An active area of research this year has been the development of data mining tools that automatically search through gigabyte data sets and extract the salient features with little or no human intervention. With these so-called feature extraction tools, engineers are spared the tedious task of manually exploring huge amounts of data to find the important flow phenomena. The software tools identify features such as vortex cores, shocks, separation and attachment lines, recirculation bubbles, and boundary layers. Some of these features can be extracted in a few seconds; others take minutes to hours on extremely large data sets. The analysis can be performed off-line in a batch process, either during or following the supercomputer simulations. These computations have to be performed only once, because the feature extraction programs search the entire data set and find every occurrence of the phenomena being sought. Because the important questions about the data are being answered automatically, interactivity is less critical than it is with traditional approaches.

  1. Interactive Terascale Particle Visualization

    NASA Technical Reports Server (NTRS)

    Ellsworth, David; Green, Bryan; Moran, Patrick

    2004-01-01

    This paper describes the methods used to produce an interactive visualization of a 2 TB computational fluid dynamics (CFD) data set using particle tracing (streaklines). We use the method introduced by Bruckschen et al. [2001] that pre-computes a large number of particles, stores them on disk using a space-filling curve ordering that minimizes seeks, and then retrieves and displays the particles according to the user's command. We describe how the particle computation can be performed using a PC cluster, how the algorithm can be adapted to work with a multi-block curvilinear mesh, and how the out-of-core visualization can be scaled to 296 billion particles while still achieving interactive performance on PG hardware. Compared to the earlier work, our data set size and total number of particles are an order of magnitude larger. We also describe a new compression technique that allows the lossless compression of the particles by 41% and speeds the particle retrieval by about 30%.

  2. Pharmacokinetic interactions with rifampicin.

    PubMed

    Zilly, W; Breimer, D D; Richter, E

    1977-01-01

    Rifampicin, a potent antituberculosis agent, is frequently combined with other antituberculosis drugs, or with drugs belonging to entirely different classes which may be required during a long period of antituberculous treatment, and therefore has a potential for drug interactions of practical clinical importance. The absorption of rifampicin is markedly decreased when it is simultaneously administered with para-aminosalicylic acid granules, due to adsorption by an excipient, bentonite. Several clinical observations and investigations have indicated that rifampicin itself accelerates the metabolism of various other compounds, including oral anticoagulants, the contraceptive pill, oral hypoglycaemic agents and digitoxin. Rifampicin seems to be a potent inducer of drug metabolism in humans and it causes a proliferation of the smooth endoplasmatic reticulum and an increase of cytochrome P450 content in the liver. It also increases its own rate of desacetylation. However, of the test compounds hexobarbitone and tolbutamide, the metabolic clearance increased 2-to 3-fold following rafampicin treatment, whereas antipyrine clearance was unaltered. This indicates that there is a certain selectivity in the enzyme induction effect of rifampicin, although it reamins unclear which compound will and which will not be affected. Rifampicin may also possibly interfere with hepatic uptake of other compounds, but the clinical significance of this type of interaction has not been clearly demonstrated; On the other hand, oral probenecid significantly increases the serum level of rifampicin, probably due to a similar depression of hepatic uptake.

  3. Time reversal interactive objects

    NASA Astrophysics Data System (ADS)

    Ing, Ros Ki; Quieffin, Nicolas; Catheline, Stefan; Fink, Mathias

    2001-05-01

    Time reversal has shown to be a fruitful concept in nondestructive testing in underwater acoustic or in ultrasonic imaging. In this paper this technique is adapted in the audible range to transform every day objects into tactile sensitive interfaces. A quick historical background is presented in the ultrasonic field and specially in chaotic cavity. In all time reversal experiments, it is demonstrated that a wave field spatially and temporally recorded is able to back propagate to its source. In other words, the field contains all the information on the location of the source. In the interactive experiments, it is shown that touching an object like a window, a table or a world globe generates an acoustic field easily detectable with one or two acoustic sensors. Using the concept of time reversal, the source location is deduced in real time. Then, touching objects at specific locations (virtual switches) is used to activate devices. Such devices are for example lights, stereo volume, or computer software. From a technical point of view, all these interactive experiments just use some computation easily performed with a standard personnel computer.

  4. Neutron Star - Magnetosphere Interactions

    NASA Astrophysics Data System (ADS)

    Ponce, Marcelo; Anderson, Matthew; Lehner, Luis; Liebling, Steven L.; Palenzuela, Carlos

    2012-03-01

    In this work we report results of the interaction of a neutron star magnetosphere in both collapsing and moving scenarios interacting with an ambient magnetic field. In recent works [1,2], it has been shown the important role and realism associated with studies of electromagnetic environments in some particular regimes, such as: ideal-MHD, force-free, and electro-vacuum. Motivated by this and their astrophysical implications for BBH and hybrid BH-NS mergers [3,4], we study the following cases: collapse of a magnetized NS, head-on collision of a BH-NS, and orbiting merger of a BH-NS. Based in the results from our simulations, we draw some relevant conclusions to the production of jets as described within the force-free formalism. [4pt] [1] C.Palenzuela, L.Lehner and S.Liebling, Science 329, 927 (2010).[0pt] [2] C.Palenzuela, T.Garrett, et al., Phys.Rev.D 82, 044045 (2010).[0pt] [3] L.Lehner, C.Palenzuela, et al., 2011.[0pt] [4] S.Liebling, L.Lehner, et al., Phys.Rev.D 81, 124023 (2010).

  5. Cotton and Protein Interactions

    SciTech Connect

    Goheen, Steven C.; Edwards, J. V.; Rayburn, Alfred R.; Gaither, Kari A.; Castro, Nathan J.

    2006-06-30

    The adsorbent properties of important wound fluid proteins and cotton cellulose are reviewed. This review focuses on the adsorption of albumin to cotton-based wound dressings and some chemically modified derivatives targeted for chronic wounds. Adsorption of elastase in the presence of albumin was examined as a model to understand the interactive properties of these wound fluid components with cotton fibers. In the chronic non-healing wound, elastase appears to be over-expressed, and it digests tissue and growth factors, interfering with the normal healing process. Albumin is the most prevalent protein in wound fluid, and in highly to moderately exudative wounds, it may bind significantly to the fibers of wound dressings. Thus, the relative binding properties of both elastase and albumin to wound dressing fibers are of interest in the design of more effective wound dressings. The present work examines the binding of albumin to two different derivatives of cotton, and quantifies the elastase binding to the same derivatives following exposure of albumin to the fiber surface. An HPLC adsorption technique was employed coupled with a colorimetric enzyme assay to quantify the relative binding properties of albumin and elastase to cotton. The results of wound protein binding are discussed in relation to the porosity and surface chemistry interactions of cotton and wound proteins. Studies are directed to understanding the implications of protein adsorption phenomena in terms of fiber-protein models that have implications for rationally designing dressings for chronic wounds.

  6. Strong-interaction nonuniversality

    SciTech Connect

    Volkas, R. R.; Foot, R.; He, X.; Joshi, G. C.

    1989-07-01

    The universal QCD color theory is extended to an SU(3)/sub 1//direct product/SU(3)/sub 2//direct product/SU(3)/sub 3/ gauge theory, where quarks of the /ital i/th generation transform as triplets under SU(3)/sub /ital i// and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements.

  7. Herb-drug interactions.

    PubMed

    Fugh-Berman, A

    2000-01-08

    Concurrent use of herbs may mimic, magnify, or oppose the effect of drugs. Plausible cases of herb-drug interactions include: bleeding when warfarin is combined with ginkgo (Ginkgo biloba), garlic (Allium sativum), dong quai (Angelica sinensis), or danshen (Salvia miltiorrhiza); mild serotonin syndrome in patients who mix St John's wort (Hypericum perforatum) with serotonin-reuptake inhibitors; decreased bioavailability of digoxin, theophylline, cyclosporin, and phenprocoumon when these drugs are combined with St John's wort; induction of mania in depressed patients who mix antidepressants and Panax ginseng; exacerbation of extrapyramidal effects with neuroleptic drugs and betel nut (Areca catechu); increased risk of hypertension when tricyclic antidepressants are combined with yohimbine (Pausinystalia yohimbe); potentiation of oral and topical corticosteroids by liquorice (Glycyrrhiza glabra); decreased blood concentrations of prednisolone when taken with the Chinese herbal product xaio chai hu tang (sho-salko-to); and decreased concentrations of phenytoin when combined with the Ayurvedic syrup shankhapushpi. Anthranoid-containing plants (including senna [Cassia senna] and cascara [Rhamnus purshiana]) and soluble fibres (including guar gum and psyllium) can decrease the absorption of drugs. Many reports of herb-drug interactions are sketchy and lack laboratory analysis of suspect preparations. Health-care practitioners should caution patients against mixing herbs and pharmaceutical drugs.

  8. Relationality and social interaction.

    PubMed

    Bottero, Wendy

    2009-06-01

    This paper explores Bourdieu's account of a relational social space, and his relative neglect of social interaction within this framework. Bourdieu includes social capital as one of the key relational elements of his social space, but says much less about it than economic or cultural capital, and levels of social capital are rarely measured in his work. Bourdieu is reluctant to focus on the content of social networks as part of his rejection of substantialist thinking. The neglect of substantive networks creates problems for Bourdieu's framework, because many of Bourdieu's core concepts rest upon assumptions about their interactional properties (in particular, the prevalence of homophilous differential association) which are left unexamined. It is argued here that Bourdieu's neglect of the substance of social networks is related to the criticisms that Bourdieu's framework often encounters, and that this neglect bears re-examination, since it is helpful to think of the ways in which differentiated social networks contribute to the development of habitus, help form fields, and so constitute the intersubjective social relations within which sociality, and practice more generally, occur.

  9. Charged Dust Aggregate Interactions

    NASA Astrophysics Data System (ADS)

    Matthews, Lorin; Hyde, Truell

    2015-11-01

    A proper understanding of the behavior of dust particle aggregates immersed in a complex plasma first requires a knowledge of the basic properties of the system. Among the most important of these are the net electrostatic charge and higher multipole moments on the dust aggregate as well as the manner in which the aggregate interacts with the local electrostatic fields. The formation of elongated, fractal-like aggregates levitating in the sheath electric field of a weakly ionized RF generated plasma discharge has recently been observed experimentally. The resulting data has shown that as aggregates approach one another, they can both accelerate and rotate. At equilibrium, aggregates are observed to levitate with regular spacing, rotating about their long axis aligned parallel to the sheath electric field. Since gas drag tends to slow any such rotation, energy must be constantly fed into the system in order to sustain it. A numerical model designed to analyze this motion provides both the electrostatic charge and higher multipole moments of the aggregate while including the forces due to thermophoresis, neutral gas drag, and the ion wakefield. This model will be used to investigate the ambient conditions leading to the observed interactions. This research is funded by NSF Grant 1414523.

  10. Cephradine antacids interaction studies.

    PubMed

    Arayne, M Saeed; Sultana, Najma; Afzal, M

    2007-07-01

    The present work comprises of interaction studies of cephradine with antacids. Cephradine is included among the first generation cephalosporin, which is active against a wide range of Gram positive and Gram-negative bacteria including penicillinase-producing staphylococci. Since the presence of complexing ligand may affect the bioavailability of a drug in blood or tissues, therefore, in order to study the probable interaction of cephradine with antacids all the reaction conditions were simulated to natural environments. Antacids are commonly used in patients complaining of GI irritations. The behavior of cephradine in presence of seven antacids i.e., simethicone, magaldrate, magnesium carbonate, magnesium hydroxide, magnesium trisilicate, sodium bicarbonate and aluminium hydroxide was studied by using standard dissolution apparatus. Cephradine was monitored both by UV and by high performance liquid chromatography. The results revealed that antacids containing polyvalent cations retarded the in vitro availability of cephradine. Moreover, these studies indicated that cephradine was strongly adsorbed on antacids; magnesium trisilicate and simeco tablets (powdered) exhibited relatively higher adsorption capacities.

  11. Mediated Discourse and Social Interaction.

    ERIC Educational Resources Information Center

    Scollon, Ron

    1999-01-01

    Suggests that future research in language and social interaction should (1) focus on studies of media or mediated discourse as forms of social interaction as one broad group; and (2) engage in the flow of postmodernist discourse. (Author/VWL)

  12. Expanding the Interaction Equivalency Theorem

    ERIC Educational Resources Information Center

    Rodriguez, Brenda Cecilia Padilla; Armellini, Alejandro

    2015-01-01

    Although interaction is recognised as a key element for learning, its incorporation in online courses can be challenging. The interaction equivalency theorem provides guidelines: Meaningful learning can be supported as long as one of three types of interactions (learner-content, learner-teacher and learner-learner) is present at a high level. This…

  13. How Interactive Is Your Whiteboard?

    ERIC Educational Resources Information Center

    Tanner, Howard; Jones, Sonia

    2007-01-01

    In this article, the authors question the assumption that interactive whiteboards (IWBs) automatically lead to interactive teaching. The authors contend that although IWBs have features that offer great potential for the development of highly interactive teaching approaches, it may be the case that teachers must have made the transition from…

  14. Bunyavirus-vector interactions.

    PubMed

    Beaty, B J; Bishop, D H

    1988-06-01

    Recent advances in the genetics and molecular biology of bunyaviruses have been applied to understanding bunyavirus-vector interactions. Such approaches have revealed which virus gene and gene products are important in establishing infections in vectors and in transmission of viruses. However, much more information is required to understand the molecular mechanisms of persistent infections of vectors which are lifelong but apparently exert no untoward effect. In fact, it seems remarkable that LAC viral antigen can be detected in almost every cell in an ovarian follicle, yet no untoward effect on fecundity and no teratology is seen. Similarly the lifelong infection of the vector would seem to provide ample opportunity for bunyavirus evolution by genetic drift and, under the appropriate circumstances, by segment reassortment. The potential for bunyavirus evolution by segment reassortment in vectors certainly exists. For example the Group C viruses in a small forest in Brazil seem to constitute a gene pool, with the 6 viruses related alternately by HI/NT and CF reactions, which assay respectively M RNA and S RNA gene products (Casals and Whitman, 1960; Shope and Causey, 1962). Direct evidence for naturally occurring reassortant bunyaviruses has also been obtained. Oligonucleotide fingerprint analyses of field isolates of LAC virus and members of the Patois serogroup of bunyaviruses have demonstrated that reassortment does occur in nature (El Said et al., 1979; Klimas et al., 1981; Ushijima et al., 1981). Determination of the genotypic frequencies of viruses selected by the biological interactions of viruses and vectors after dual infection and segment reassortment is an important issue. Should a virus result that efficiently interacts with alternate vector species, the virus could be expressed in different circumstances with serious epidemiologic consequences. Dual infection of vectors with different viruses is not unlikely, because many bunyaviruses are sympatric in

  15. Human-Robot Interaction

    NASA Technical Reports Server (NTRS)

    Sandor, Aniko; Cross, E. Vincent, II; Chang, Mai Lee

    2015-01-01

    Human-robot interaction (HRI) is a discipline investigating the factors affecting the interactions between humans and robots. It is important to evaluate how the design of interfaces affect the human's ability to perform tasks effectively and efficiently when working with a robot. By understanding the effects of interface design on human performance, workload, and situation awareness, interfaces can be developed to appropriately support the human in performing tasks with minimal errors and with appropriate interaction time and effort. Thus, the results of research on human-robot interfaces have direct implications for the design of robotic systems. For efficient and effective remote navigation of a rover, a human operator needs to be aware of the robot's environment. However, during teleoperation, operators may get information about the environment only through a robot's front-mounted camera causing a keyhole effect. The keyhole effect reduces situation awareness which may manifest in navigation issues such as higher number of collisions, missing critical aspects of the environment, or reduced speed. One way to compensate for the keyhole effect and the ambiguities operators experience when they teleoperate a robot is adding multiple cameras and including the robot chassis in the camera view. Augmented reality, such as overlays, can also enhance the way a person sees objects in the environment or in camera views by making them more visible. Scenes can be augmented with integrated telemetry, procedures, or map information. Furthermore, the addition of an exocentric (i.e., third-person) field of view from a camera placed in the robot's environment may provide operators with the additional information needed to gain spatial awareness of the robot. Two research studies investigated possible mitigation approaches to address the keyhole effect: 1) combining the inclusion of the robot chassis in the camera view with augmented reality overlays, and 2) modifying the camera

  16. IDG - INTERACTIVE DIF GENERATOR

    NASA Technical Reports Server (NTRS)

    Preheim, L. E.

    1994-01-01

    The Interactive DIF Generator (IDG) utility is a tool used to generate and manipulate Directory Interchange Format files (DIF). Its purpose as a specialized text editor is to create and update DIF files which can be sent to NASA's Master Directory, also referred to as the International Global Change Directory at Goddard. Many government and university data systems use the Master Directory to advertise the availability of research data. The IDG interface consists of a set of four windows: (1) the IDG main window; (2) a text editing window; (3) a text formatting and validation window; and (4) a file viewing window. The IDG main window starts up the other windows and contains a list of valid keywords. The keywords are loaded from a user-designated file and selected keywords can be copied into any active editing window. Once activated, the editing window designates the file to be edited. Upon switching from the editing window to the formatting and validation window, the user has options for making simple changes to one or more files such as inserting tabs, aligning fields, and indenting groups. The viewing window is a scrollable read-only window that allows fast viewing of any text file. IDG is an interactive tool and requires a mouse or a trackball to operate. IDG uses the X Window System to build and manage its interactive forms, and also uses the Motif widget set and runs under Sun UNIX. IDG is written in C-language for Sun computers running SunOS. This package requires the X Window System, Version 11 Revision 4, with OSF/Motif 1.1. IDG requires 1.8Mb of hard disk space. The standard distribution medium for IDG is a .25 inch streaming magnetic tape cartridge in UNIX tar format. It is also available on a 3.5 inch diskette in UNIX tar format. The program was developed in 1991 and is a copyrighted work with all copyright vested in NASA. SunOS is a trademark of Sun Microsystems, Inc. X Window System is a trademark of Massachusetts Institute of Technology. OSF/Motif is a

  17. Synchronization and hydrodynamic interactions

    NASA Astrophysics Data System (ADS)

    Powers, Thomas; Qian, Bian; Breuer, Kenneth

    2008-03-01

    Cilia and flagella commonly beat in a coordinated manner. Examples include the flagella that Volvox colonies use to move, the cilia that sweep foreign particles up out of the human airway, and the nodal cilia that set up the flow that determines the left-right axis in developing vertebrate embryos. In this talk we present an experimental study of how hydrodynamic interactions can lead to coordination in a simple idealized system: two nearby paddles driven with fixed torques in a highly viscous fluid. The paddles attain a synchronized state in which they rotate together with a phase difference of 90 degrees. We discuss how synchronization depends on system parameters and present numerical calculations using the method of regularized stokeslets.

  18. Interacting neural networks

    NASA Astrophysics Data System (ADS)

    Metzler, R.; Kinzel, W.; Kanter, I.

    2000-08-01

    Several scenarios of interacting neural networks which are trained either in an identical or in a competitive way are solved analytically. In the case of identical training each perceptron receives the output of its neighbor. The symmetry of the stationary state as well as the sensitivity to the used training algorithm are investigated. Two competitive perceptrons trained on mutually exclusive learning aims and a perceptron which is trained on the opposite of its own output are examined analytically. An ensemble of competitive perceptrons is used as decision-making algorithms in a model of a closed market (El Farol Bar problem or the Minority Game. In this game, a set of agents who have to make a binary decision is considered.); each network is trained on the history of minority decisions. This ensemble of perceptrons relaxes to a stationary state whose performance can be better than random.

  19. Interactive molecular dynamics

    NASA Astrophysics Data System (ADS)

    Schroeder, Daniel V.

    2015-03-01

    Physics students now have access to interactive molecular dynamics simulations that can model and animate the motions of hundreds of particles, such as noble gas atoms, that attract each other weakly at short distances but repel strongly when pressed together. Using these simulations, students can develop an understanding of forces and motions at the molecular scale, nonideal fluids, phases of matter, thermal equilibrium, nonequilibrium states, the Boltzmann distribution, the arrow of time, and much more. This article summarizes the basic features and capabilities of such a simulation, presents a variety of student exercises using it at the introductory and intermediate levels, and describes some enhancements that can further extend its uses. A working simulation code, in html5 and javascript for running within any modern Web browser, is provided as an online supplement.

  20. Fluid structure interaction

    NASA Astrophysics Data System (ADS)

    Komatsu, K.

    A few nonflow field problems are considered, taking into account mainly fluid-shell dynamic interaction and fluid-solid impact. Fluid-shell systems are used as models for sloshing and POGO (structure-propulsion coupling oscillation) in liquid rockets, floating lids of oil tanks, large tanks containing fluid, nuclear containment vessels, and head injury studies in biomechanics. The study of structure-water impact finds applications in the problems associated with water landings of reentry vehicles, water entry of torpedoes, and slamming of ships in heavy seas. At least three different methods can be used in handling wet structures. Attention is given to the method which treats fluid by boundary elements and structure by finite elements.

  1. Critical Density Interaction Studies

    SciTech Connect

    Young, P; Baldis, H A; Cheung, P; Rozmus, W; Kruer, W; Wilks, S; Crowley, S; Mori, W; Hansen, C

    2001-02-14

    Experiments have been performed to study the propagation of intense laser pulses to high plasma densities. The issue of self-focusing and filamentation of the laser pulse as well as developing predictive capability of absorption processes and x-ray conversion efficiencies is important for numerous programs at the Laboratory, particularly Laser Program (Fast Ignitor and direct-drive ICF) and D&NT (radiography, high energy backlighters and laser cutting). Processes such as resonance absorption, profile modification, linear mode conversion, filamentation and stimulated Brillouin scattering can occur near the critical density and can have important effects on the coupling of laser light to solid targets. A combination of experiments have been used to study the propagation of laser light to high plasma densities and the interaction physics of intense laser pulses with solid targets. Nonparaxial fluid codes to study nonstationary behavior of filamentation and stimulated Brillouin scattering at high densities have also been developed as part of this project.

  2. Parvovirus glycan interactions.

    PubMed

    Huang, Lin-Ya; Halder, Sujata; Agbandje-McKenna, Mavis

    2014-08-01

    Members of the Parvoviridae utilize glycan receptors for cellular attachment and subsequent interactions determine transduction efficiency or pathogenic outcome. This review focuses on the identity of the glycan receptors utilized, their capsid binding footprints, and a discussion of the overlap of these sites with tropism, transduction, and pathogenicity determinants. Despite high sequence diversity between the different genera, most parvoviruses bind to negatively charged glycans, such as sialic acid and heparan sulfate, abundant on cell surface membranes. The capsid structure of these viruses exhibit high structural homology enabling common regions to be utilized for glycan binding. At the same time the sequence diversity at the common footprints allows for binding of different glycans or differential binding of the same glycan.

  3. Three dimensional interactive display

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2005-01-01

    A three-dimensional (3-D) interactive display and method of forming the same, includes a transparent capaciflector (TC) camera formed on a transparent shield layer on the screen surface. A first dielectric layer is formed on the shield layer. A first wire layer is formed on the first dielectric layer. A second dielectric layer is formed on the first wire layer. A second wire layer is formed on the second dielectric layer. Wires on the first wire layer and second wire layer are grouped into groups of parallel wires with a turnaround at one end of each group and a sensor pad at the opposite end. An operational amplifier is connected to each of the sensor pads and the shield pad biases the pads and receives a signal from connected sensor pads in response to intrusion of a probe. The signal is proportional to probe location with respect to the monitor screen.

  4. Interactive TV Narrativity

    NASA Astrophysics Data System (ADS)

    Ursu, Marian F.

    Looking back over the past 25 years, the impressive developments in information and communication technologies generated a booming popularity of the new forms of media consumption that allow for interactivity and mobility, such as Web information and entertainment and games. This was and still is particularly evident within the younger generation, who are the most avid adopters of both new technologies and new forms of media consumption (Schadler 2006; KPMG 2007). When asked, in 2006, which device they could not live without, 37% mentioned their PC, 26% their mobile phone, whereas only 17% mentioned their TVs (Schadler 2006); and all these were before the launch of products such as the iPhone, which offer increasing flexibility and mobility of the media experiences.

  5. Universality in string interactions

    NASA Astrophysics Data System (ADS)

    Huang, Yu-tin; Schlotterer, Oliver; Wen, Congkao

    2016-09-01

    In this note, we provide evidence for universality in the low-energy expansion of tree-level string interactions. More precisely, in the α'-expansion of tree-level scattering amplitudes, we conjecture that the leading transcendental coefficient at each order in α' is universal for all perturbative string theories. We have checked this universality up to seven points and trace its origin to the ability to restructure the disk integrals of open bosonic string into those of the superstring. The accompanying kinematic functions have the same low-energy limit and do not introduce any transcendental numbers in their α'-corrections. Universality in the closed-string sector then follows from KLT-relations.

  6. Drugging Membrane Protein Interactions

    PubMed Central

    Yin, Hang; Flynn, Aaron D.

    2016-01-01

    The majority of therapeutics target membrane proteins, accessible on the surface of cells, to alter cellular signaling. Cells use membrane proteins to transduce signals into cells, transport ions and molecules, bind the cell to a surface or substrate, and catalyze reactions. Newly devised technologies allow us to drug conventionally “undruggable” regions of membrane proteins, enabling modulation of protein–protein, protein–lipid, and protein–nucleic acid interactions. In this review, we survey the state of the art in high-throughput screening and rational design in drug discovery, and we evaluate the advances in biological understanding and technological capacity that will drive pharmacotherapy forward against unorthodox membrane protein targets. PMID:26863923

  7. Tracking protein aggregate interactions

    PubMed Central

    Bartz, Jason C; Nilsson, K Peter R

    2011-01-01

    Amyloid fibrils share a structural motif consisting of highly ordered β-sheets aligned perpendicular to the fibril axis.1, 2 At each fibril end, β-sheets provide a template for recruiting and converting monomers.3 Different amyloid fibrils often co-occur in the same individual, yet whether a protein aggregate aids or inhibits the assembly of a heterologous protein is unclear. In prion disease, diverse prion aggregate structures, known as strains, are thought to be the basis of disparate disease phenotypes in the same species expressing identical prion protein sequences.4–7 Here we explore the interactions reported to occur when two distinct prion strains occur together in the central nervous system. PMID:21597336

  8. Glycosaminoglycan-lipoprotein interaction.

    PubMed

    Olsson, U; Ostergren-Lundén, G; Moses, J

    2001-10-01

    Glycosaminoglycans (GAGs) bound to various proteoglycans (PGs) present in the cardiovascular system have been proposed to perform a wide range of functions. These include conferring viscoelastic properties; interacting with and modulating growth factors and enzymes; and as receptors and co-receptors in lipoprotein metabolism. Binding of apoB-100 lipoproteins, particularly low density lipoproteins (LDL), to GAGs of extracellular matrix PGs in arteries has been proposed to be an initiating event in development of atherosclerosis. This study was initiated with the aim of getting an overview of the binding patterns of different lipoprotein subclasses with individual GAG categories. We thus evaluated the interaction of lipoproteins with GAGs commonly found in the cardiovascular system using a gel mobility-shift assay developed for this purpose. The same procedure was used to measure lipoproteins binding to metabolically [(35)S]-labeled whole PGs prepared from three cell types, arterial smooth muscle cells, THP-1 macrophages and from HepG2 cells. The effect of GAG composition on PGs on lipoprotein binding was evaluated by enzymatic degradation of the carbohydrate chains. Heparan sulfate was found to bind beta very low density lipoproteins (beta-VLDL) and a chylomicron remnant model (beta-VLDL+apoE), but not LDL. Dermatan sulfate was found to bind LDL, but not beta-VLDL or the chylomicron remnant model. Chondroitin sulfate and heparin were found to bind all lipoproteins tested (LDL, beta-VLDL and beta-VLDL+apoE) although with different affinities. We can conclude that each lipoprotein subclass tested binds a specific assortment of the GAGs tested. The observations made contribute to the understanding of new and complex mechanisms by which carbohydrate and lipid metabolism may be linked.

  9. Polymer-Nucleic Acid Interactions.

    PubMed

    Shen, Zhuang-Lin; Xia, Yi-Qi; Yang, Qiu-Song; Tian, Wen-de; Chen, Kang; Ma, Yu-Qiang

    2017-04-01

    Gene therapy is an important therapeutic strategy in the treatment of a wide range of genetic disorders. Polymers forming stable complexes with nucleic acids (NAs) are non-viral gene carriers. The self-assembly of polymers and nucleic acids is typically a complex process that involves many types of interaction at different scales. Electrostatic interaction, hydrophobic interaction, and hydrogen bonds are three important and prevalent interactions in the polymer/nucleic acid system. Electrostatic interactions and hydrogen bonds are the main driving forces for the condensation of nucleic acids, while hydrophobic interactions play a significant role in the cellular uptake and endosomal escape of polymer-nucleic acid complexes. To design high-efficiency polymer candidates for the DNA and siRNA delivery, it is necessary to have a detailed understanding of the interactions between them in solution. In this chapter, we survey the roles of the three important interactions between polymers and nucleic acids during the formation of polyplexes and summarize recent understandings of the linear polyelectrolyte-NA interactions and dendrimer-NA interactions. We also review recent progress optimizing the gene delivery system by tuning these interactions.

  10. Developing a general interaction potential for hydrophobic and hydrophilic interactions.

    PubMed

    Donaldson, Stephen H; Røyne, Anja; Kristiansen, Kai; Rapp, Michael V; Das, Saurabh; Gebbie, Matthew A; Lee, Dong Woog; Stock, Philipp; Valtiner, Markus; Israelachvili, Jacob

    2015-02-24

    We review direct force measurements on a broad class of hydrophobic and hydrophilic surfaces. These measurements have enabled the development of a general interaction potential per unit area, W(D) = -2γ(i)Hy exp(-D/D(H)) in terms of a nondimensional Hydra parameter, Hy, that applies to both hydrophobic and hydrophilic interactions between extended surfaces. This potential allows one to quantitatively account for additional attractions and repulsions not included in the well-known combination of electrostatic double layer and van der Waals theories, the so-called Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The interaction energy is exponentially decaying with decay length D(H) ≈ 0.3-2 nm for both hydrophobic and hydrophilic interactions, with the exact value of D(H) depending on the precise system and conditions. The pre-exponential factor depends on the interfacial tension, γ(i), of the interacting surfaces and Hy. For Hy > 0, the interaction potential describes interactions between partially hydrophobic surfaces, with the maximum hydrophobic interaction (i.e., two fully hydrophobic surfaces) corresponding to Hy = 1. Hydrophobic interactions between hydrophobic monolayer surfaces measured with the surface forces apparatus (SFA) are shown to be well described by the proposed interaction potential. The potential becomes repulsive for Hy < 0, corresponding to partially hydrophilic (hydrated) interfaces. Hydrated surfaces such as mica, silica, and lipid bilayers are discussed and reviewed in the context of the values of Hy appropriate for each system.

  11. Discovering interacting domains and motifs in protein-protein interactions.

    PubMed

    Hugo, Willy; Sung, Wing-Kin; Ng, See-Kiong

    2013-01-01

    Many important biological processes, such as the signaling pathways, require protein-protein interactions (PPIs) that are designed for fast response to stimuli. These interactions are usually transient, easily formed, and disrupted, yet specific. Many of these transient interactions involve the binding of a protein domain to a short stretch (3-10) of amino acid residues, which can be characterized by a sequence pattern, i.e., a short linear motif (SLiM). We call these interacting domains and motifs domain-SLiM interactions. Existing methods have focused on discovering SLiMs in the interacting proteins' sequence data. With the recent increase in protein structures, we have a new opportunity to detect SLiMs directly from the proteins' 3D structures instead of their linear sequences. In this chapter, we describe a computational method called SLiMDIet to directly detect SLiMs on domain interfaces extracted from 3D structures of PPIs. SLiMDIet comprises two steps: (1) interaction interfaces belonging to the same domain are extracted and grouped together using structural clustering and (2) the extracted interaction interfaces in each cluster are structurally aligned to extract the corresponding SLiM. Using SLiMDIet, de novo SLiMs interacting with protein domains can be computationally detected from structurally clustered domain-SLiM interactions for PFAM domains which have available 3D structures in the PDB database.

  12. Interactive Projector as an Interactive Teaching Tool in the Classroom: Evaluating Teaching Efficiency and Interactivity

    ERIC Educational Resources Information Center

    Liu, Li-Ying; Cheng, Meng-Tzu

    2015-01-01

    This study reports on a measurement that is used to investigate interactivity in the classrooms and examines the impact of integrating the interactive projector into middle school science classes on classroom interactivity and students' biology learning. A total of 126 7th grade Taiwanese students were involved in the study and quasi-experimental…

  13. Arc electrode interaction study

    NASA Technical Reports Server (NTRS)

    Zhou, X.; Berns, D.; Heberlein, J.

    1994-01-01

    The project consisted of two parts: (1) the cathode interaction studies which were a continuation of previous work and had the objective of increasing our understanding of the microscopic phenomena controlling cathode erosion in arc jet thrusters, and (2) the studies of the anode attachment in arc jet thrusters. The cathode interaction studies consisted of (1) a continuation of some modeling work in which the previously derived model for the cathode heating was applied to some specific gases and electrode materials, and (2) experimental work in which various diagnostics was applied to the cathode. The specific diagnostics used were observation of the cathode tip during arcing using a Laser Strobe Video system in conjunction with a tele-microscope, a monochromator with an optical multichannel analyzer for the determination of the cathode temperature distribution, and various ex situ materials analysis methods. The emphasis of our effort was shifted to the cathode materials analysis because a parallel project was in place during the second half of 1993 with a visiting scientist pursuing arc electrode materials studies. As a consequence, the diagnostic investigations of the arc in front of the cathode had to be postponed to the first half of 1994, and we are presently preparing these measurements. The results of last year's study showed some unexpected effects influencing the cathode erosion behavior, such as increased erosion away from the cathode tip, and our understanding of these effects should improve our ability to control cathode erosion. The arc jet anode attachment studies concentrated on diagnostics of the instabilities in subsonic anode attachment arc jet thrusters, and were supplemental measurements to work which was performed by one of the authors who spent the summer as an intern at NASA Lewis Research Center. A summary of the results obtained during the internship are included because they formed an integral part of the study. Two tasks for 1994, the

  14. Electron Interactions in Graphene

    NASA Astrophysics Data System (ADS)

    Kim, Philip

    2011-03-01

    Electrons confined in two dimensions (2D) can exhibit strongly correlated states. Recent experimental discovery of integer and fractional quantum Hall effect in graphene amplified interest in correlated 2D electronic systems, owning to presence of the unusual topological phase associated with zero effective mass of charge carriers. In this talk, we will discuss the role of the many-body effects due to the electron-electron interaction in graphene manifested in electron transport phenomena. In particular, we will discuss the nature unusual spontaneous symmetry breaking Landau levels graphene under the extreme quantum condition, the appearance of unique low density insulating states and fractional quantum Hall states. Employing extremely high quality samples obtained by suspending graphene and graphene on atomically flat defect free insulating substrate such as hexa-bron nitride, we now investigate various broken symmetry states under high magnetic field. The nature of these broken symmetry state can be explained generally considering underlying SU(4) symmetry in the single particle level of the Landau levels.

  15. Atmospheric Ball Plasma Interactions

    NASA Astrophysics Data System (ADS)

    Wurden, C. J. V.; Wurden, G. A.

    2008-11-01

    Free-floating atmospheric pressure copper hydroxyl ball plasmas have been studied in air and helium atmospheres, using still and high speed photography (up to 20,000 fps), collimated photodiodes, and spectroscopy. A fine boundary layer between the greenish Cu-OH cloud, and the air, is orange in color. However, when the discharge is initiated into a helium atmosphere, the boundary layer is no longer visible, suggesting that the visible boundary was caused by interactions with oxygen. We have studied scaling of the 10-cm diameter ball plasmas with both the size of the water bucket, and the applied discharge voltage, over the range of 500-5000 volts. When looking at the initial spider-leg breakdown above the water surface, the ratio of H-alpha to H-beta lines suggests a temperature of ˜0.3 eV. This is also consistent with the presence of molecular lines of OH, and perhaps CuOH2 in the rising cloud. The cloud is affected by, but can penetrate through an aluminum window screen mesh.

  16. "Interactive Classification Technology"

    NASA Technical Reports Server (NTRS)

    deBessonet, Cary

    1999-01-01

    The investigators are upgrading a knowledge representation language called SL (Symbolic Language) and an automated reasoning system called SMS (Symbolic Manipulation System) to enable the technologies to be used in automated reasoning and interactive classification systems. The overall goals of the project are: a) the enhancement of the representation language SL to accommodate multiple perspectives and a wider range of meaning; b) the development of a sufficient set of operators to enable the interpreter of SL to handle representations of basic cognitive acts; and c) the development of a default inference scheme to operate over SL notation as it is encoded. As to particular goals the first-year work plan focused on inferencing and.representation issues, including: 1) the development of higher level cognitive/ classification functions and conceptual models for use in inferencing and decision making; 2) the specification of a more detailed scheme of defaults and the enrichment of SL notation to accommodate the scheme; and 3) the adoption of additional perspectives for inferencing.

  17. SEEPAGE/BACKFILL INTERACTIONS

    SciTech Connect

    P. Mariner

    2000-04-14

    As directed by written development plan (CRWMS M&O 1999a), a sub-model of seepage/backfill interactions is developed and presented in this document to support the Engineered Barrier System (EBS) Physical and Chemical Environment Model. The purpose of this analysis is to assist Performance Assessment Operations (PAO) and the Engineered Barrier Performance Department in modeling the geochemical environment within a repository drift. In this analysis, a conceptual model is developed to provide PAO a more detailed and complete in-drift geochemical model abstraction and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near Field Environment (NFE) Revision 2 (NRC 1999). The development plan calls for a sub-model that evaluates the effect on water chemistry of chemical reactions between water that enters the drift and backfill materials in the drift. The development plan specifically requests an evaluation of the following important chemical reaction processes: dissolution-precipitation, aqueous complexation, and oxidation-reduction. The development plan also requests the evaluation of the effects of varying seepage and drainage fluxes, varying temperature, and varying evaporation and condensation fluxes. Many of these effects are evaluated in a separate Analysis/Model Report (AMR), ''Precipitates Salts Analysis AMR'' (CRWMS M&O 2000), so the results of that AMR are referenced throughout this AMR.

  18. Hydrogen interactions with metals

    NASA Technical Reports Server (NTRS)

    Mclellan, R. B.; Harkins, C. G.

    1975-01-01

    Review of the literature on the nature and extent of hydrogen interactions with metals and the role of hydrogen in metal failure. The classification of hydrogen-containing systems is discussed, including such categories as covalent hydrides, volatile hydrides, polymeric hydrides, and transition metal hydride complexes. The use of electronegativity as a correlating parameter in determining hydride type is evaluated. A detailed study is made of the thermodynamics of metal-hydrogen systems, touching upon such aspects as hydrogen solubility, the positions occupied by hydrogen atoms within the solvent metal lattice, the derivation of thermodynamic functions of solid solutions from solubility data, and the construction of statistical models for hydrogen-metal solutions. A number of theories of hydrogen-metal bonding are reviewed, including the rigid-band model, the screened-proton model, and an approach employing the augmented plane wave method to solve the one-electron energy band problem. Finally, the mechanism of hydrogen embrittlement is investigated on the basis of literature data concerning stress effects and the kinetics of hydrogen transport to critical sites.

  19. Influenza-Sediment Interactions

    NASA Astrophysics Data System (ADS)

    Trusiak, A.; Block, K. A.; Katz, A.; Gottlieb, P.; Alimova, A.; Galarza, J.; Wei, H.; Steiner, J. C.

    2013-12-01

    A typical water fowl can secrete 1012 influenza virions per day. Therefore it is not unexpected that influenza virions interact with sediments in the water column. The influence of sediments on avian influenza virions is not known. With the threat of avian influenza emerging into the human population, it is crucial to understand virus survivability and residence time in a body of water. Influenza and clay sediments are colloidal particles and thus aggregate as explained by DLVO (Derjaguin & Landau, Verwey & Overbeek) theory. Of great importance is an understanding of the types of particulate or macromolecular components that bind the virus particles, and whether the virus remains biologically active. We present results of hetero-aggregation and transmission electron microscopy experiments performed with influenza A/PR8/38. Influenza particles are suspended with sediment and minimal nutrients for several days, after which the components are evaluated to determine influenza concentration and survivability. Transmission electron microscopy results are reported on the influenza-sediment aggregates to elucidate structure and morphology of the components.

  20. The many faces of interaction.

    PubMed

    Reynolds, P A; Mason, R; Harper, J

    2008-05-24

    During the process of learning teachers and/or students interact with each other on a personal level. However, in e-learning the process is achieved through the intermediary of an information and communication technology (ICT) system or service. Descriptions of these ICT-human interface devices are given in this paper. Successful interaction depends not just on personal relationships, but also on understanding and the ability to use computers and communications equipment effectively. Interactivity, when using ICT, may as a result be different from that in a traditional classroom. The computer is the main man-machine interface and modulates people's ability to interact. Newer, mobile technology will extend the ability to interact in terms of time and place, as is illustrated by the use of portable digital assistants for dental teaching in clinics. The paper concludes that it is very important that both teachers and students should understand how to interact optimally with current and future ICT systems and devices.

  1. Interaction Models for Functional Regression

    PubMed Central

    USSET, JOSEPH; STAICU, ANA-MARIA; MAITY, ARNAB

    2015-01-01

    A functional regression model with a scalar response and multiple functional predictors is proposed that accommodates two-way interactions in addition to their main effects. The proposed estimation procedure models the main effects using penalized regression splines, and the interaction effect by a tensor product basis. Extensions to generalized linear models and data observed on sparse grids or with measurement error are presented. A hypothesis testing procedure for the functional interaction effect is described. The proposed method can be easily implemented through existing software. Numerical studies show that fitting an additive model in the presence of interaction leads to both poor estimation performance and lost prediction power, while fitting an interaction model where there is in fact no interaction leads to negligible losses. The methodology is illustrated on the AneuRisk65 study data. PMID:26744549

  2. Interactive Raytracing: The nirt Command

    DTIC Science & Technology

    2009-04-01

    Interactive Raytracing : The nirt Command by Clifford Yapp ARL-CR-624 April 2009 prepared by Quantum Research...Laboratory Aberdeen Proving Ground, MD 21005-5068 ARL-CR-624 April 2009 Interactive Raytracing : The nirt Command Clifford Yapp Quantum...DATES COVERED (From - To) June 2008–October 2008 4. TITLE AND SUBTITLE Interactive Raytracing : The nirt Command 5a. CONTRACT NUMBER W911QX-06-F

  3. Interactions between Chemokines

    PubMed Central

    Cook, Anna; Hippensteel, Randi; Shimizu, Saori; Nicolai, Jaclyn; Fatatis, Alessandro; Meucci, Olimpia

    2010-01-01

    The soluble form of the chemokine fractalkine/CX3CL1 regulates microglia activation in the central nervous system (CNS), ultimately affecting neuronal survival. This study aims to determine whether CXCL12, another chemokine constitutively expressed in the CNS (known as stromal cell-derived factor 1; SDF-1), regulates cleavage of fractalkine from neurons. To this end, ELISA was used to measure protein levels of soluble fractalkine in the medium of rat neuronal cultures exposed to SDF-1. Gene arrays, quantitative RT-PCR, and Western blot were used to measure overall fractalkine expression in neurons. The data show that the rate of fractalkine shedding in healthy cultures positively correlates with in vitro differentiation and survival. In analogy to non-neuronal cells, metalloproteinases (ADAM10/17) are involved in cleavage of neuronal fractalkine as indicated by studies with pharmacologic inhibitors. Moreover, treatment of the neuronal cultures with SDF-1 stimulates expression of the inducible metalloproteinase ADAM17 and increases soluble fractalkine content in culture medium. The effect of SDF-1 is blocked by an inhibitor of both ADAM10 and -17, but only partially affected by a more specific inhibitor of ADAM10. In addition, SDF-1 also up-regulates expression of the fractalkine gene. Conversely, exposure of neurons to an excitotoxic stimulus (i.e. NMDA) inhibits α-secretase activity and markedly diminishes soluble fractalkine levels, leading to cell death. These results, along with previous findings on the neuroprotective role of both SDF-1 and fractalkine, suggest that this novel interaction between the two chemokines may contribute to in vivo regulation of neuronal survival by modulating microglial neurotoxic properties. PMID:20124406

  4. Studies on Strong Interactions

    NASA Astrophysics Data System (ADS)

    Coriano, Claudio

    Five studies, four in Quantum field theory and one in fermionic molecular dynamics are presented. In the first study, introduced in chapter one and developed in chapter two of this dissertation, we formulate an extension of QCD sum rules to Compton scattering of the pion at intermediate energy. The chapter is based on the research paper Fixed angle pion Compton scattering and QCD sum rules by Prof. George Sterman and the author, which has been submitted for publication as a regular article. In chapter 3 we discuss the relation between traditional bosonic exchange models of nuclear strong interaction and soliton models, in the particular case of the sine-Gordon model. The chapter is based on the research paper "Scattering in soliton models and bosonic exchange descriptions", by R. R. Parwani, H. Yamagishi, I. Zahed and the author, and is published in Phys. Rev. D 45 (1992), 2542. A preprint of this paper (Preprint 1) has been included as an Appendix to the Chapter. In Chapter 4 we discuss aspects of the propagation of quantized fields in classical backgrounds, using the light-cone expansion of the propagator. The chapter is based on the research papers "Electrodynamics in the presence of an axion", published by the author in Modern Physics Letters A 7 (1992), 1253, and on the paper "Singularity of Green's function and the effective action in massive Yang Mills theories, by Prof. H. Yamagishi and the author. This last paper is published in Physical Review D 41 (1990), 3226 and its reprint appears in the final part of the Chapter (Reprint 1). In chapter 5, entitled "On the time dependent Rayleigh-Ritz equations", we discuss aspects of the variational approach to fermionic molecular dynamics. This investigation by R. Parwani, H. Yamagishi and the author has been published in Nucl. Physics A 522 (1991), 591. A preprint of this research paper has been inserted in the final part of the Chapter (Preprint 2).

  5. Nutrition and parasite interaction.

    PubMed

    Coop, R L; Holmes, P H

    1996-01-01

    This overview focuses on the interaction between nutritional status and gastrointestinal nematode infection in ruminants and considers: (i) the influence of the parasite on host metabolism; and (ii) the effect of host nutrition on the establishment and survival of parasite populations, the development of the host-immune response and the pathophysiology of infection. Gastrointestinal nematodes reduce voluntary feed intake and efficiency of feed utilisation, a key feature being an increased endogenous loss of protein into the gastrointestinal tract. Overall there is movement of protein from productive processes into repair of the gastrointestinal tract, synthesis of plasma proteins and mucoprotein production. Although reduction in feed intake is a major factor contributing to the reduced performance of parasitised ruminants, the underlying mechanisms of the anorexia are poorly understood. Supplementation of the diet with additional protein does not appear to affect initial establishment of nematode infections but the pathophysiological consequences are generally more severe on lower planes of protein nutrition. The main effect of protein supplementation is to increase the rate of acquisition of immunity and increase resistance to reinfection and this has been associated with an enhanced cellular immune response in the gastrointestinal mucosa. The unresponsiveness of the young lamb can be improved by dietary protein supplementation. Recent trials have shown that growing sheep offered a free choice between a low and a high protein ration are able to modify their diet selection in order to alleviate the increase in protein requirements which result from gastrointestinal nematode infection. Studies on the influence of nutrition on the expression of genotype have shown that the benefits of a superior genotype are not lost on a low protein diet whereas a high protein diet can partially emeliorate the disadvantages of an inferior genotype. In addition to dietary protein

  6. RIBOSOME-MEMBRANE INTERACTION

    PubMed Central

    Adelman, M. R.; Sabatini, David D.; Blobel, Günter

    1973-01-01

    In a medium of high ionic strength, rat liver rough microsomes can be nondestructively disassembled into ribosomes and stripped membranes if nascent polypeptides are discharged from the bound ribosomes by reaction with puromycin. At 750 mM KCl, 5 mM MgCl2, 50 mM Tris·HCl, pH 7 5, up to 85% of all bound ribosomes are released from the membranes after incubation at room temperature with 1 mM puromycin. The ribosomes are released as subunits which are active in peptide synthesis if programmed with polyuridylic acid. The ribosome-denuded, or stripped, rough microsomes (RM) can be recovered as intact, essentially unaltered membranous vesicles Judging from the incorporation of [3H]puromycin into hot acid-insoluble material and from the release of [3H]leucine-labeled nascent polypeptide chains from bound ribosomes, puromycin coupling occurs almost as well at low (25–100 mM) as at high (500–1000 mM) KCl concentrations. Since puromycin-dependent ribosome release only occurs at high ionic strength, it appears that ribosomes are bound to membranes via two types of interactions: a direct one between the membrane and the large ribosomal subunit (labile at high KCl concentration) and an indirect one in which the nascent chain anchors the ribosome to the membrane (puromycin labile). The nascent chains of ribosomes specifically released by puromycin remain tightly associated with the stripped membranes. Some membrane-bound ribosomes (up to 40%) can be nondestructively released in high ionic strength media without puromycin; these appear to consist of a mixture of inactive ribosomes and ribosomes containing relatively short nascent chains. A fraction (∼15%) of the bound ribosomes can only be released from membranes by exposure of RM to ionic conditions which cause extensive unfolding of ribosomal subunits, the nature and significance of these ribosomes is not clear. PMID:4682341

  7. Theoretical studies of molecular interactions

    SciTech Connect

    Lester, W.A. Jr.

    1993-12-01

    This research program is directed at extending fundamental knowledge of atoms and molecules including their electronic structure, mutual interaction, collision dynamics, and interaction with radiation. The approach combines the use of ab initio methods--Hartree-Fock (HF) multiconfiguration HF, configuration interaction, and the recently developed quantum Monte Carlo (MC)--to describe electronic structure, intermolecular interactions, and other properties, with various methods of characterizing inelastic and reaction collision processes, and photodissociation dynamics. Present activity is focused on the development and application of the QMC method, surface catalyzed reactions, and reorientation cross sections.

  8. Structural interaction with control systems

    NASA Technical Reports Server (NTRS)

    Noll, R. B.; Zvara, J.

    1971-01-01

    A monograph which assesses the state of the art of space vehicle design and development is presented. The monograph presents criteria and recommended practices for determining the structural data and a mathematical structural model of the vehicle needed for accurate prediction of structure and control-system interaction; for design to minimize undesirable interactions between the structure and the control system; and for determining techniques to achieve the maximum desirable interactions and associated structural design benefits. All space vehicles are treated, including launch vehicles, spacecraft, and entry vehicles. Important structural characteristics which affect the structural model used for structural and control-system interaction analysis are given.

  9. Imaging van der Waals Interactions.

    PubMed

    Han, Zhumin; Wei, Xinyuan; Xu, Chen; Chiang, Chi-Lun; Zhang, Yanxing; Wu, Ruqian; Ho, W

    2016-12-15

    The van der Waals interactions are responsible for a large diversity of structures and functions in chemistry, biology, and materials. Discussion of van der Waals interactions has focused on the attractive potential energy that varies as the inverse power of the distance between the two interacting partners. The origin of the attractive force is widely discussed as being due to the correlated fluctuations of electron charges that lead to instantaneous dipole-induced dipole attractions. Here, we use the inelastic tunneling probe to image the potential energy surface associated with the van der Waals interactions of xenon atoms.

  10. Interactive TV on parliament session

    NASA Astrophysics Data System (ADS)

    Royer, J.; Nguyen, H.; Martinot, O.; Preda, M.; Preteux, F.; Zaharia, T.

    2007-09-01

    This paper introduces a new interactive mobile TV application related to parliament session. This application aims to provide additional information to mobile TV users by inserting automatically and in real-time interactive contents (complementary information, subject of the current session...) into original TV program, using MPEG-4 streaming video and extra real time information (news, events, databases... from RSS streams, Internet links...). Here, we propose an architecture based on plug-in multimedia analyzers to generate the contextual description of the media and on an interactive scene generator to dynamically create related interactive scenes. Description is implemented according to the MPEG-7 standard.

  11. [Antibiotics: drug and food interactions].

    PubMed

    Hodel, M; Genné, D

    2009-10-07

    Antibiotics are widely prescribed in medical practice. Many of them induce or are subject to interactions that may diminish their anti-infectious efficiency or elicit toxic effects. Food intake can influence the effectiveness of an antibiotic. Certain antibiotics can lower the effectiveness of oral contraception. Oral anticoagulation can be influenced to a great extent by antibiotics and controls are necessary. Interactions are also possible via enzymatic induction or inhibition of cytochromes. The use of an interaction list with substrates of cytochromes enables to anticipate. Every new prescription should consider a possible drug or food interaction.

  12. Plasma interactions with large spacecraft

    NASA Technical Reports Server (NTRS)

    Sagalyn, Rita C.; Maynard, Nelson C.

    1986-01-01

    Space is playing a rapidly expanding role in the conduct of the Air Force mission. Larger, more complex, high-power space platforms are planned and military astronauts will provide a new capability in spacecraft servicing. Interactions of operational satellites with the environment have been shown to degrade space sensors and electronics and to constrain systems operations. The environmental interaction effects grow nonlinearly with increasing size and power. Quantification of the interactions and development of mitigation techniques for systems-limiting interactions is essential to the success of future Air Force space operations.

  13. Self-interacting dark matter

    SciTech Connect

    Tulin, Sean

    2014-06-24

    The particle physics nature of dark matter (DM) can leave an imprint on the structure of Universe. If DM has a sizable cross section for self-interactions (much larger than the typical weak scale cross section), this can affect the density profiles of DM halos. Moreover, there exist long-standing discrepancies on small scales between astrophysical observations and predictions from N-body simulations of collisionless DM, which suggests that DM may be self-interacting. Here, we review these discrepancies, we discuss the particle physics implications of self-interacting DM, and we show that DM self-interactions have interesting implications for direct and indirect detection searches.

  14. RKKY interaction in bilayer graphene

    NASA Astrophysics Data System (ADS)

    Mohammadi, Yawar; Moradian, Rostam

    2015-12-01

    We study the RKKY interaction between two magnetic impurities located on the same layer (intralayer case) or on different layers (interlayer case) in undoped bilayer graphene (BLG) in the four-bands model, by directly calculating the Green functions in the eigenvalues and eigenvectors representation. Our results show that both intra- and interlayer RKKY interactions between two magnetic impurities located on the same (opposite) sublattice are always ferromagnetic (antiferromagnetic). Furthermore we find unusual long-distance decay of the RKKY interaction in BLG. The intralyer RKKY interactions between two magnetic impurities located on the same sublattice, J AnAn(R) and J BnBn(R), decay closely as 1 /R6 and 1 /R2 at large impurity distances respectively, but when they are located on opposite sublattices the RKKY interactions exhibit 1 /R4 decays approximately. In the interlayer case, the RKKY interactions between two magnetic impurities located on the same sublattice show a decay close to 1 /R4 at large impurity distances, but if two magnetic impurities be on opposite sublattices the RKKY interactions, J A1B2(R) and J B1A2(R), decay closely as 1 /R6 and 1 /R2 respectively. Both intra- and interlayer RKKY interactions have anisotropic oscillatory factors which for intralayer case is equal to that for single layer graphene (SLG). Our results at weak and strong interlayer coupling limits reduce to the RKKY interaction of SLG and that of BLG in the two-bands approximation respectively.

  15. INCA- INTERACTIVE CONTROLS ANALYSIS

    NASA Technical Reports Server (NTRS)

    Bauer, F. H.

    1994-01-01

    The Interactive Controls Analysis (INCA) program was developed to provide a user friendly environment for the design and analysis of linear control systems, primarily feedback control systems. INCA is designed for use with both small and large order systems. Using the interactive graphics capability, the INCA user can quickly plot a root locus, frequency response, or time response of either a continuous time system or a sampled data system. The system configuration and parameters can be easily changed, allowing the INCA user to design compensation networks and perform sensitivity analysis in a very convenient manner. A journal file capability is included. This stores an entire sequence of commands, generated during an INCA session into a file which can be accessed later. Also included in INCA are a context-sensitive help library, a screen editor, and plot windows. INCA is robust to VAX-specific overflow problems. The transfer function is the basic unit of INCA. Transfer functions are automatically saved and are available to the INCA user at any time. A powerful, user friendly transfer function manipulation and editing capability is built into the INCA program. The user can do all transfer function manipulations and plotting without leaving INCA, although provisions are made to input transfer functions from data files. By using a small set of commands, the user may compute and edit transfer functions, and then examine these functions by using the ROOT_LOCUS, FREQUENCY_RESPONSE, and TIME_RESPONSE capabilities. Basic input data, including gains, are handled as single-input single-output transfer functions. These functions can be developed using the function editor or by using FORTRAN- like arithmetic expressions. In addition to the arithmetic functions, special functions are available to 1) compute step, ramp, and sinusoid functions, 2) compute closed loop transfer functions, 3) convert from S plane to Z plane with optional advanced Z transform, and 4) convert from Z

  16. Interactions among the Imagination, Expertise Reversal, and Element Interactivity Effects

    ERIC Educational Resources Information Center

    Leahy, Wayne; Sweller, John

    2005-01-01

    Interactions among the imagination, expertise reversal, and element interactivity effects were investigated in 2 experiments. In Experiment 1, less knowledgeable primary school students learning to use a bus timetable produced better performance under study than imagination conditions, but an increase in their experience reversed the result,…

  17. Why Interactivity Works: Interactive Priming of Mental Rotation

    ERIC Educational Resources Information Center

    Smith, Glenn Gordon; Olkun, Sinan

    2005-01-01

    This study has important implications for microworlds such as Logo, HyperGami, and Newton's World, which use interaction to learn spatial mental models for science, math, geometry, etc. This study tested the hypothesis that interactively rotating (dragging) virtual shapes primes mental rotation. The independent variable was observation vs.…

  18. Josef Alber's "Interaction of Color": From Print to Interactive Multimedia.

    ERIC Educational Resources Information Center

    Whiteley, Jerry; Roberts, Joseph

    1990-01-01

    Describes the development of interactive, multimedia courseware based on Josef Alber's book, "Interaction of Color." Alber's ideas and teachings on the perceptions of color are explained, and steps involving computer graphics, hardware, and software that resulted in the use of CD-ROM and videodisc with an Apple Macintosh II are detailed.…

  19. Interact - Access to the Arctic

    NASA Astrophysics Data System (ADS)

    Johansson, M.; Callaghan, T. V.

    2013-12-01

    INTERACT is currently a network of 50 terrestrial research stations from all Arctic countries, but is still growing. The network was inaugurated in January 2011 when it received an EU 7th Framework award. INTERACT's main objective is to build capacity for identifying, understanding, predicting and responding to diverse environmental changes throughout the wide environmental and land-use envelopes of the Arctic. Implicit in this objective is the task to build capacity for monitoring, research, education and outreach. INTERACT is increasing access to the Arctic: 20 INTERACT research stations in Europe and Russia are offering Transnational Access and so far, 5600 person-days of access have been granted from the total of 10,000 offered. An INTERACT Station Managers' Forum facilitates a dialogue among station managers on subjects such as best practice in station management and standardised monitoring. The Station Managers' Forum has produced a unique 'one-stop-shop' for information from 45 research stations in an informative and attractive Station Catalogue that is available in hard copy and on the INTERACT web site (www.eu-interact.org). INTERACT also includes three joint research activities that are improving monitoring in remote, harsh environments and are making data capture and dissemination more efficient. Already, new equipment for measuring feedbacks from the land surface to the climate system has been installed at several locations, while best practices for sensor networking have been established. INTERACT networks with most of the high-level Arctic organisations: it includes AMAP and WWF as partners, is endorsed by IASC and CBMP, has signed MoUs with ISAC and the University of the Arctic, is a task within SAON, and contributes to the Cold Region community within GEO/GEOSS. INTERACT welcomes other interactions.

  20. Interactions between Diatoms and Bacteria

    PubMed Central

    Amin, Shady A.; Parker, Micaela S.

    2012-01-01

    Summary: Diatoms and bacteria have cooccurred in common habitats for hundreds of millions of years, thus fostering specific associations and interactions with global biogeochemical consequences. Diatoms are responsible for one-fifth of the photosynthesis on Earth, while bacteria remineralize a large portion of this fixed carbon in the oceans. Through their coexistence, diatoms and bacteria cycle nutrients between oxidized and reduced states, impacting bioavailability and ultimately feeding higher trophic levels. Here we present an overview of how diatoms and bacteria interact and the implications of these interactions. We emphasize that heterotrophic bacteria in the oceans that are consistently associated with diatoms are confined to two phyla. These consistent bacterial associations result from encounter mechanisms that occur within a microscale environment surrounding a diatom cell. We review signaling mechanisms that occur in this microenvironment to pave the way for specific interactions. Finally, we discuss known interactions between diatoms and bacteria and exciting new directions and research opportunities in this field. Throughout the review, we emphasize new technological advances that will help in the discovery of new interactions. Deciphering the languages of diatoms and bacteria and how they interact will inform our understanding of the role these organisms have in shaping the ocean and how these interactions may change in future oceans. PMID:22933565

  1. Gaming Redefines Interactivity for Learning

    ERIC Educational Resources Information Center

    DeKanter, Nick

    2005-01-01

    The new definition of interactivity has as its focal point the skills of people, not the capabilities of the technology. The goal is to enhance the interaction between people and the learning that can only occur among curious and motivated individuals working together. The social nature of people, the increasing capabilities of technology and the…

  2. Speculations on Design Team Interactions.

    ERIC Educational Resources Information Center

    Hedberg, John; Sims, Rod

    2001-01-01

    Discussion of the design of effective learning environments focuses on design team interactions. Topics include designer intention and instructor implementation; technology tools and their use; instructional design processes, including computer interfaces and interaction possibilities; learner as actor; multimedia; and interpersonal communication.…

  3. Interactive Cultural Cultivating in FLT

    ERIC Educational Resources Information Center

    Yang, Youwen

    2010-01-01

    Culture cultivating in foreign language teaching (FLT) is usually conducted through factual introductions in the form of articles, books, seminars, lectures or workshops. This approach regards L2 learners as passive receivers of cultural knowledge without their interaction involved. This paper aims at raising an interactive approach to develop L2…

  4. Assessing Preference for Social Interactions

    ERIC Educational Resources Information Center

    Clay, Casey J.; Samaha, Andrew L.; Bloom, Sarah E.; Bogoev, Bistra K.; Boyle, Megan A.

    2013-01-01

    We examined a procedure to assess preference for social interactions in individuals with intellectual and developmental disabilities. Preferences were identified in five individuals using a paired-choice procedure in which participants approached therapists who provided different forms of social interactions. A subsequent tracking test showed that…

  5. Results-Based Interaction Design

    ERIC Educational Resources Information Center

    Weiss, Meredith

    2008-01-01

    Interaction design is a user-centered approach to development in which users and their goals are the driving force behind a project's design. Interaction design principles are fundamental to the design and implementation of effective websites, but they are not sufficient. This article argues that, to reach its full potential, a website should also…

  6. Interactive Flow in Exercise Pedagogy

    ERIC Educational Resources Information Center

    Lloyd, Rebecca; Smith, Stephen

    2006-01-01

    A phenomenology of the bodily experience of interactive flow adds to Csikszentmihalyi's flow theory. Whereas Csikszentmihalyi attended to teachers' and students' experiences of flow separately, this inquiry explores flow through three water-inspired layers of physical interaction between fitness professionals and their clients. Teaching fitness is…

  7. Interactions between diatoms and bacteria.

    PubMed

    Amin, Shady A; Parker, Micaela S; Armbrust, E Virginia

    2012-09-01

    Diatoms and bacteria have cooccurred in common habitats for hundreds of millions of years, thus fostering specific associations and interactions with global biogeochemical consequences. Diatoms are responsible for one-fifth of the photosynthesis on Earth, while bacteria remineralize a large portion of this fixed carbon in the oceans. Through their coexistence, diatoms and bacteria cycle nutrients between oxidized and reduced states, impacting bioavailability and ultimately feeding higher trophic levels. Here we present an overview of how diatoms and bacteria interact and the implications of these interactions. We emphasize that heterotrophic bacteria in the oceans that are consistently associated with diatoms are confined to two phyla. These consistent bacterial associations result from encounter mechanisms that occur within a microscale environment surrounding a diatom cell. We review signaling mechanisms that occur in this microenvironment to pave the way for specific interactions. Finally, we discuss known interactions between diatoms and bacteria and exciting new directions and research opportunities in this field. Throughout the review, we emphasize new technological advances that will help in the discovery of new interactions. Deciphering the languages of diatoms and bacteria and how they interact will inform our understanding of the role these organisms have in shaping the ocean and how these interactions may change in future oceans.

  8. Strong interactions in air showers

    SciTech Connect

    Dietrich, Dennis D.

    2015-03-02

    We study the role new gauge interactions in extensions of the standard model play in air showers initiated by ultrahigh-energy cosmic rays. Hadron-hadron events remain dominated by quantum chromodynamics, while projectiles and/or targets from beyond the standard model permit us to see qualitative differences arising due to the new interactions.

  9. Environmental Interactions Working Group Report

    NASA Technical Reports Server (NTRS)

    Stevens, N. J.; Wiskerchen, M.

    1984-01-01

    Interactions between spacecraft systems and the space charged particle environment are reviewed and recommendations are presented for both near-term and far-term research considerations. Transient environment models, large space structures, solar and nuclear power systems/environment interactions, single event upsets, material degradation, and planetary missions are addressed.

  10. The Power of Interactive Whiteboards.

    ERIC Educational Resources Information Center

    Ekhaml, Leticia

    2002-01-01

    Describes the use of interactive whiteboards, a new type of instructional presentation technology that allows users to control computer applications from the board. Highlights include vendors; multimedia online instruction; rear-projection models; examples of classroom uses; contests and opportunities for schools to obtain interactive whiteboards;…

  11. The Wonders of Interactive Whiteboards

    ERIC Educational Resources Information Center

    Starkman, Neal

    2006-01-01

    This article discusses the advantages of using interactive whiteboards in the classroom. Developed by Smart Technologies, the Smart Board is one of several interactive whiteboards on the market today. Through Smart Board, starters can write, erase, and perform mouse functions with their finger, a pen, or anything with a maneuverable, firm surface.…

  12. Mental Models in Social Interaction

    ERIC Educational Resources Information Center

    Fernandez-Berrocal, Pablo; Santamaria, Carlos

    2006-01-01

    In this study, the authors introduce a new way to analyze cognitive change during social interactions, based on the mental model theory of reasoning. From this approach, cognitive performance can be improved for solving problems that require multiple models when participants in a social interaction group maintain qualitatively different models of…

  13. Distinguishing Ordinal and Disordinal Interactions

    ERIC Educational Resources Information Center

    Widaman, Keith F.; Helm, Jonathan L.; Castro-Schilo, Laura; Pluess, Michael; Stallings, Michael C.; Belsky, Jay

    2012-01-01

    Re-parameterized regression models may enable tests of crucial theoretical predictions involving interactive effects of predictors that cannot be tested directly using standard approaches. First, we present a re-parameterized regression model for the Linear x Linear interaction of 2 quantitative predictors that yields point and interval estimates…

  14. Perceived Attractiveness and Classroom Interactions

    ERIC Educational Resources Information Center

    Algozzine, Bob

    1977-01-01

    Adams and Cohen (1974) demonstrated that facial attractiveness was a salient factor in differential student-teacher interactions. This research investigates further the interaction between teachers and children perceived to be attractive or unattractive by those teachers. It was hypothesized that attractive children would exhibit more "positive,"…

  15. Designing Interactive Online Nursing Courses

    ERIC Educational Resources Information Center

    Jain, Smita; Jain, Pawan

    2015-01-01

    This study empirically tests the relation between the instructional design elements and the overall meaningful interactions among online students. Eighteen online graduate nursing courses are analyzed using bivariate and multivariate analysis techniques. Findings suggest that the quantity of meaningful interaction among learners can be improved by…

  16. Scattering calculations and confining interactions

    NASA Technical Reports Server (NTRS)

    Buck, Warren W.; Maung, Khin M.

    1993-01-01

    Most of the research work performed under this grant were concerned with strong interaction processes ranging from kaon-nucleon interaction to proton-nucleus scattering calculations. Research performed under this grant can be categorized into three groups: (1) parametrization of fundamental interactions, (2) development of formal theory, and (3) calculations based upon the first two. Parametrizations of certain fundamental interactions, such as kaon-nucleon interaction, for example, were necessary because kaon-nucleon scattering amplitude was needed to perform kaon-nucleus scattering calculations. It was possible to calculate kaon-nucleon amplitudes from the first principle, but it was unnecessary for the purpose of the project. Similar work was also done for example for anti-protons and anti-nuclei. Formal developments to some extent were also pursued so that consistent calculations can be done.

  17. Emotional intelligence and social interaction.

    PubMed

    Lopes, Paulo N; Brackett, Marc A; Nezlek, John B; Schütz, Astrid; Sellin, Ina; Salovey, Peter

    2004-08-01

    Two studies found positive relationships between the ability to manage emotions and the quality of social interactions, supporting the predictive and incremental validity of an ability measure of emotional intelligence, the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). In a sample of 118 American college students (Study 1), higher scores on the managing emotions subscale of the MSCEIT were positively related to the quality of interactions with friends, evaluated separately by participants and two friends. In a diary study of social interaction with 103 German college students (Study 2), managing emotions scores were positively related to the perceived quality of interactions with opposite sex individuals. Scores on this subscale were also positively related to perceived success in impression management in social interactions with individuals of the opposite sex. In both studies, the main findings remained statistically significant after controlling for Big Five personality traits.

  18. Hyperfine interaction in hydrogenated graphene

    NASA Astrophysics Data System (ADS)

    Garcia, Noel; Melle, Manuel; Fernandez-Rossier, Joaquin

    We study the hyperfine interaction of Hydrogen chemisorbed in graphene nanostructures with a gap in their spectrum, such as islands and ribbons. Chemisorption of Hydrogen on graphene results in a bound in-gap state that hosts a single electron localized around the adatom. Using both density functional theory and a four-orbital tight-binding model we study the hyperfine interaction between the hydrogen nuclear spin and the conduction electrons in graphene. We find that the strength of the hyperfine interaction decreases for larger nanostructures for which the energy gap is smaller. We then compare the results of the hyperfine interaction for large nanostructures with those of graphene 2D crystal with a periodic arrangement of chemisorbed Hydrogen atoms, obtaining very similar results. The magnitude of the hyperfine interaction is about 150 MHz, in line with that of Si:P. We acknowledge financial support by Marie-Curie-ITN 607904-SPINOGRAPH.

  19. Electrostatic interactions in molecular materials

    NASA Astrophysics Data System (ADS)

    Painelli, Anna; Terenziani, Francesca

    2004-03-01

    Non-additive collective behavior appears in molecular materials as a result of intermolecular interactions. We present a model for interacting polar and polarizable molecules that applies to different supramolecular architectures of donor-π-acceptor molecules. We follow a bottom-up modeling strategy: the detailed analysis of spectroscopic data of solvated molecules leads to the definition of a simple two-state model for the molecular units. Classical electrostatic interactions are then introduced to model molecular clusters. The molecular properties are strickingly affected by supramolecular interactions, as demonstrated by spectroscopic studies. Brand new phenomena, like phase transitions and multielectron transfer, with no counterpart at the molecular level are observed as direct consequences of electrostatic intermolecular interactions.

  20. Interactive computer code for dynamic and soil structure interaction analysis

    SciTech Connect

    Mulliken, J.S.

    1995-12-01

    A new interactive computer code is presented in this paper for dynamic and soil-structure interaction (SSI) analyses. The computer program FETA (Finite Element Transient Analysis) is a self contained interactive graphics environment for IBM-PC`s that is used for the development of structural and soil models as well as post-processing dynamic analysis output. Full 3-D isometric views of the soil-structure system, animation of displacements, frequency and time domain responses at nodes, and response spectra are all graphically available simply by pointing and clicking with a mouse. FETA`s finite element solver performs 2-D and 3-D frequency and time domain soil-structure interaction analyses. The solver can be directly accessed from the graphical interface on a PC, or run on a number of other computer platforms.

  1. Adverse food-drug interactions.

    PubMed

    de Boer, Alie; van Hunsel, Florence; Bast, Aalt

    2015-12-01

    Food supplements and herbal products are increasingly popular amongst consumers. This leads to increased risks of interactions between prescribed drugs and these products containing bioactive ingredients. From 1991 up to 2014, 55 cases of suspected adverse drug reactions due to concomitant intake of health-enhancing products and drugs were reported to Lareb, the Netherlands Pharmacovigilance Centre. An overview of these suspected interactions is presented and their potential mechanisms of action are described. Mainly during the metabolism of xenobiotics and due to the pharmacodynamics effects interactions seem to occur, which may result in adverse drug reactions. Where legislation is seen to distinct food and medicine, legislation concerning these different bioactive products is less clear-cut. This can only be resolved by increasing the molecular knowledge on bioactive substances and their potential interactions. Thereby potential interactions can be better understood and prevented on an individual level. By considering the dietary pattern and use of bioactive substances with prescribed medication, both health professionals and consumers will be increasingly aware of interactions and these interactive adverse effects can be prevented.

  2. Additive interaction between heterogeneous environmental ...

    EPA Pesticide Factsheets

    BACKGROUND Environmental exposures often occur in tandem; however, epidemiological research often focuses on singular exposures. Statistical interactions among broad, well-characterized environmental domains have not yet been evaluated in association with health. We address this gap by conducting a county-level cross-sectional analysis of interactions between Environmental Quality Index (EQI) domain indices on preterm birth in the Unites States from 2000-2005.METHODS: The EQI, a county-level index constructed for the 2000-2005 time period, was constructed from five domain-specific indices (air, water, land, built and sociodemographic) using principal component analyses. County-level preterm birth rates (n=3141) were estimated using live births from the National Center for Health Statistics. Linear regression was used to estimate prevalence differences (PD) and 95% confidence intervals (CI) comparing worse environmental quality to the better quality for each model for a) each individual domain main effect b) the interaction contrast and c) the two main effects plus interaction effect (i.e. the “net effect”) to show departure from additive interaction for the all U.S counties. Analyses were also performed for subgroupings by four urban/rural strata. RESULTS: We found the suggestion of antagonistic interactions but no synergism, along with several purely additive (i.e., no interaction) associations. In the non-stratified model, we observed antagonistic interac

  3. Haldane relation for interacting dimers

    NASA Astrophysics Data System (ADS)

    Giuliani, Alessandro; Mastropietro, Vieri; Lucio Toninelli, Fabio

    2017-03-01

    We consider a model of weakly interacting close-packed dimers on the two-dimensional square lattice. In a previous paper, we computed both the multi-point dimer correlations, which display non-trivial critical exponents, continuously varying with the interaction strength; and the height fluctuations, which, after proper coarse graining and rescaling, converge to a massless Gaussian field with a suitable interaction-dependent pre-factor (‘amplitude’). In this paper, we prove the identity between the critical exponent of the two-point dimer correlation and the amplitude of this massless Gaussian field. This identity is the restatement, in the context of interacting dimers, of one of the Haldane universality relations, part of his Luttinger-liquid conjecture, originally formulated in the context of one-dimensional interacting Fermi systems. Its validity is a strong confirmation of the effective massless Gaussian field description of the interacting dimer model, which was proposed on the basis of formal bosonization arguments. We also conjecture that a certain discrete curve defined at the lattice level via the Temperley bijection converges in the scaling limit to an SLE κ process, with κ depending non-trivially on the interaction and related in a simple way to the amplitude of the limiting Gaussian field.

  4. A 3% Measurement of the Beam Normal Single Spin Asymmetry in Forward Angle Elastic Electron-Proton Scattering using the Qweak Setup

    SciTech Connect

    Waidyawansa, Dinayadura Buddhini

    2013-08-01

    The beam normal single spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable of the imaginary part of the two-photon exchange process. Moreover, it is a potential source of false asymmetry in parity violating electron scattering experiments. The Q{sub weak} experiment uses parity violating electron scattering to make a direct measurement of the weak charge of the proton. The targeted 4% measurement of the weak charge of the proton probes for parity violating new physics beyond the Standard Model. The beam normal single spin asymmetry at Q{sub weak} kinematics is at least three orders of magnitude larger than 5 ppb precision of the parity violating asymmetry. To better understand this parity conserving background, the Q{sub weak} Collaboration has performed elastic scattering measurements with fully transversely polarized electron beam on the proton and aluminum. This dissertation presents the analysis of the 3% measurement (1.3% statistical and 2.6% systematic) of beam normal single spin asymmetry in electronproton scattering at a Q2 of 0.025 (GeV/c)2. It is the most precise existing measurement of beam normal single spin asymmetry available at the time. A measurement of this precision helps to improve the theoretical models on beam normal single spin asymmetry and thereby our understanding of the doubly virtual Compton scattering process.

  5. Recovery of Electron/Proton Radiation-Induced Defects in n+p AlInGaP Solar Cell by Minority-Carrier Injection Annealing

    NASA Technical Reports Server (NTRS)

    Lee, H. S.; Yamaguchi, M.; Elkins-Daukes, N. J.; Khan, A.; Takamoto, T.; Imaizumi, M.; Ohshima, T.; Itoh, H.

    2007-01-01

    A high efficient In0.48Ga0.52P/In0.01Ga0.99As/Ge triple junction solar cell has been developed for application in space and terrestrial concentrator PV system [1-3]. Recently, a high conversion efficiency of 31.5% (AM1.5G) has been obtained in InGaP/(In)GaAs/Ge triple junction solar cell, and as a new top cell material of triple junction cells, (Al)InGaP [1] has been proposed to improve the open-circuit voltage (Voc) because it shows a higher Voc of 1.5V while maintaining the same short-circuit current (ISC) as a conventional InGaP top cell under AM1.5G conditions as seen in figure 1 (a). Moreover, the spectral response of 1.96eV AlInGaP cell with a thickness of 2.5..m shows a higher response in the long wavelength region, compared with that of 1.87eV InGaP cell with 0.6..m thickness, as shown in figure 1 (b). Its development will realize next generation multijunction (MJ) solar cells such as a lattice mismatched AlInGaP/InGaAs/Ge 3-junction and lattice matched AlInGaP/GaAs/InGaAsN/Ge 4-junction solar cells. Figure 2 shows the super high-efficiency MJ solar cell structures and wide band spectral response by MJ solar cells under AM1.5G conditions. For realizing high efficient MJ space solar cells, the higher radiation-resistance under the electron or proton irradiation is required. The irradiation studies for a conventional top cell InGaP have been widely done [4-6], but little irradiation work has been performed on AlInGaP solar cells. Recently, we made the first reports of 1 MeV electron or 30 keV proton irradiation effects on AlInGaP solar cells, and evaluated the defects generated by the irradiation [7,8]. The present study describes the recovery of 1 MeV electron / 30 keV proton irradiation-induced defects in n+p- AlInGaP solar cells by minority-carrier injection enhanced annealing or isochronal annealing. The origins of irradiation-induced defects observed by deep level transient spectroscopy (DLTS) measurements are discussed.

  6. INSTRUMENTS AND METHODS OF INVESTIGATION: Electron-proton separation in calorimetry experiments directly measuring the composition and energy spectrum of cosmic rays

    NASA Astrophysics Data System (ADS)

    Voronov, Sergei A.; Borisov, Stanislav V.; Karelin, Aleksandr V.

    2009-09-01

    Calorimetric particle detectors that play an important role in high-energy cosmic-ray balloon and satellite experiments not only have the major task of measuring energy but also face the problem of identifying electrons and protons. This problem is usually solved by measuring the longitudinal and traverse shower profiles and the total energy release in the calorimeter, using the fact that electromagnetic and hadronic showers differ in their spatial and energy distributions. In this paper, electron and proton identification methods for different types of calorimeters used in cosmic-ray balloon- and satellite-borne experiments are discussed.

  7. Next-to-leading-order QCD corrections to jet cross sections and jet rates in deeply inelastic electron-proton scattering

    SciTech Connect

    Graudenz, D. )

    1994-04-01

    Jet cross sections in deeply inelastic scattering in the case of transverse photon exchange for the production of (1+1) and (2+1) jets are calculated in next-to-leading-order QCD (here the +1'' stands for the target remnant jet, which is included in the jet definition). The jet definition scheme is based on a modified JADE cluster algorithm. The calculation of the (2+1) jet cross section is described in detail. Results for the virtual corrections as well as for the real initial- and final-state corrections are given explicitly. Numerical results are stated for jet cross sections as well as for the ratio [sigma][sub (2+1) jet]/[sigma][sub tot] that can be expected at E665 and DESY HERA. Furthermore the scale ambiguity of the calculated jet cross sections is studied and different parton density parametrizations are compared.

  8. Hidden interaction in SBO galaxies

    NASA Technical Reports Server (NTRS)

    Galletta, G.; Bettoni, D.; Oosterloo, T.; Fasano, G.

    1990-01-01

    Galaxies, like plants, show a large variety of grafts: an individual of some type connects physically with a neighborhood of same or different type. The effects of these interactions between galaxies have a broad range of morphologies depending, among other quantities, on the distance of the closest approach between systems and the relative size of the two galaxies. A sketch of the possible situations is shown in tabular form. This botanical classification is just indicative, because the effects of interactions can be notable also at relatively large separations, when additional conditions are met, as for example low density of the interacting systems or the presence of intra-cluster gas. In spite of the large variety of encounters and effects, in the literature the same terms are often used to refer to different types of interactions. Analysis indicates that only few of the situations show evident signs of interaction. They appear to be most relevant when the size of the two galaxies is comparable. Bridges and tails, like the well known case of NGC 4038/39, the Antennae, are only observed for a very low percentage of all galaxies (approx. 0.38 percent, Arp and Madore 1977). In most cases of gravitational bond between two galaxies, the effects of interactions are not relevant or evident. For instance, the detection of stellar shells (Malin and Carter 1983), which have been attributed to the accretion of gas stripped from another galaxy or to the capture and disruption of a small stellar system (Quinn 1984), requires particular observing and reduction techniques. Besides these difficulties of detection, time plays an important role in erasing, within a massive galaxy, the effects of interactions with smaller objects. This can happen on a timescale shorter than the Hubble time, so the number of systems now showing signs of interaction suggests lower limits to the true frequency of interactions in the life-time of a stellar system.

  9. Aligned interactions in cosmic rays

    NASA Astrophysics Data System (ADS)

    Kempa, J.

    2015-12-01

    The first clean Centauro was found in cosmic rays years many ago at Mt Chacaltaya experiment. Since that time, many people have tried to find this type of interaction, both in cosmic rays and at accelerators. But no one has found a clean cases of this type of interaction.It happened finally in the last exposure of emulsion at Mt Chacaltaya where the second clean Centauro has been found. The experimental data for both the Centauros and STRANA will be presented and discussed in this paper. We also present our comments to the intriguing question of the existence of a type of nuclear interactions at high energy with alignment.

  10. Aligned interactions in cosmic rays

    SciTech Connect

    Kempa, J.

    2015-12-15

    The first clean Centauro was found in cosmic rays years many ago at Mt Chacaltaya experiment. Since that time, many people have tried to find this type of interaction, both in cosmic rays and at accelerators. But no one has found a clean cases of this type of interaction.It happened finally in the last exposure of emulsion at Mt Chacaltaya where the second clean Centauro has been found. The experimental data for both the Centauros and STRANA will be presented and discussed in this paper. We also present our comments to the intriguing question of the existence of a type of nuclear interactions at high energy with alignment.

  11. Invariants of 4-wave interactions

    NASA Astrophysics Data System (ADS)

    Balk, A.; Ferapontov, E.

    1993-05-01

    We give a complete description of one-dimensional 4-wave resonance interactions in which some extra quantities (besides momentum, energy, number of quasiparticles) are conserved. In this way we obtain new consideration laws for the kinetic equations for waves. In particular, we consider waves in optical fibers, the system of four resonantly interacting wave packets, long wave interactions of annihilation-creation type, various wave systems with quadratic dispersion laws. The results can be important for various problems concerning nonlinear wave dynamics, e.g. for nonlinear optics of waveguides.

  12. Generalized interactions supported on hypersurfaces

    NASA Astrophysics Data System (ADS)

    Exner, Pavel; Rohleder, Jonathan

    2016-04-01

    We analyze a family of singular Schrödinger operators with local singular interactions supported by a hypersurface Σ ⊂ ℝn, n ≥ 2, being the boundary of a Lipschitz domain, bounded or unbounded, not necessarily connected. At each point of Σ the interaction is characterized by four real parameters, the earlier studied case of δ- and δ'-interactions being particular cases. We discuss spectral properties of these operators and derive operator inequalities between those referring to the same hypersurface but different couplings and describe their implications for spectral properties.

  13. Research in interactive scene analysis

    NASA Technical Reports Server (NTRS)

    Tenenbaum, J. M.; Barrow, H. G.; Weyl, S. A.

    1976-01-01

    Cooperative (man-machine) scene analysis techniques were developed whereby humans can provide a computer with guidance when completely automated processing is infeasible. An interactive approach promises significant near-term payoffs in analyzing various types of high volume satellite imagery, as well as vehicle-based imagery used in robot planetary exploration. This report summarizes the work accomplished over the duration of the project and describes in detail three major accomplishments: (1) the interactive design of texture classifiers; (2) a new approach for integrating the segmentation and interpretation phases of scene analysis; and (3) the application of interactive scene analysis techniques to cartography.

  14. Neutral-current weak interactions at an EIC

    NASA Astrophysics Data System (ADS)

    Zhao, Y. X.; Deshpande, A.; Huang, J.; Kumar, K. S.; Riordan, S.

    2017-03-01

    A simulation study of measurements of neutral current structure functions of the nucleon at the future high-energy and high-luminosity polarized electron-ion collider (EIC) is presented. A new series of γ- Z interference structure functions, F1^{γ Z}, F3^{γ Z}, g1^{γ Z}, g5^{γ Z} become accessible via parity-violating asymmetries in polarized electron-nucleon deep inelastic scattering (DIS). Within the context of the quark-parton model, they provide a unique and, in some cases, yet-unmeasured combination of unpolarized and polarized parton distribution functions. The uncertainty projections for these structure functions using electron-proton collisions are considered for various EIC beam energy configurations. Also presented are uncertainty projections for measurements of the weak mixing angle sin2 θW using electron-deuteron collisions which cover a much higher Q2 than that accessible in fixed target measurements. QED and QCD radiative corrections and effects of detector smearing are included with the calculations.

  15. Vehicle environment interactions - An overview

    NASA Technical Reports Server (NTRS)

    Raitt, W. J.

    1988-01-01

    The advent of Space Shuttle Orbital operations utilizing science and technology payloads has led to a renewal of interest of vehicle-environmental interactions in low earth orbit. The first science payload on STS-3 showed an interaction on the surface of the Orbiter which, although it had been detected earlier on unmanned spacecraft, quickened interest in the possible impact of this phenomena on future missions. Subsequent flights have yielded data on a wide variety of interaction phenomena resulting from the large size of the Orbiter and its outgassing characteristics. These drivers have given rise to modifications in the neutral gas and plasma environments of the Space Shuttle Orbiter. The physics of the interactions result in the generation of disturbed wave fields, optical emissions and particle distributions in the vicinity of the Orbiter. In this overview, the present observations, suggested interpretations and open questions will be addressed.

  16. An interacting adiabatic quantum motor

    NASA Astrophysics Data System (ADS)

    Viola Kusminskiy, Silvia; Bruch, Anton; von Oppen, Felix

    We consider the effect of electron-electron interactions on the performance of an adiabatic quantum motor based on a Thouless pump operating in reverse. We model such a device by electrons in a 1d wire coupled to a slowly moving periodic potential associated with the classical mechanical degree of freedom of the motor. This periodic degree of freedom is set into motion by a bias voltage applied to the 1d electron channel. We investigate the Thouless motor with interacting leads modeled as Luttinger liquids. We show that interactions enhance the energy gap opened by the periodic potential and thus the robustness of the Thouless motor against variations in the chemical potential. We show that the motor degree of freedom can be described as a mobile impurity in a Luttinger liquid obeying Langevin dynamics with renormalized coefficients due to interactions, for which we give explicit expressions.

  17. Interaction energy of nonidentical atoms

    NASA Astrophysics Data System (ADS)

    Berman, P. R.

    2015-04-01

    There are different results in the literature for the interaction energy of two separated nonidentical atoms in the case when one of the atoms is prepared in an excited state. Moreover, there are different ways to define this interaction energy. If the interaction energy is defined as a shift in the energy of the initial state of the combined atomic system, it is possible to carry out a time-dependent calculation that provides an unambiguous method for obtaining this shift. The time-dependent calculations lead to an interaction energy that is an oscillatory function of the interatomic separation, in contrast to the nonoscillatory behavior that is predicted using an alternative theory based on time-independent perturbation theory.

  18. Bibliotherapy--The Interactive Process.

    ERIC Educational Resources Information Center

    Hynes, Arleen McCarty

    1987-01-01

    Discusses the similarities between what librarians call activity bibliotherapy and psychotherapists call poetry therapy, and the need for cooperation between these professions. The interactive aspects of bibliotherapy and the need for professional training in this process are emphasized. (CLB)

  19. Weak interactions and presupernova evolution

    SciTech Connect

    Aufderheide, M.B. State Univ. of New York . Dept. of Physics)

    1991-02-19

    The role of weak interactions, particularly electron capture and {beta}{sup {minus}} decay, in presupernova evolution is discussed. The present uncertainty in these rates is examined and the possibility of improving the situation is addressed. 12 refs., 4 figs.

  20. Revealing Non-Covalent Interactions

    PubMed Central

    Johnson, Erin R.; Keinan, Shahar; Mori-Sánchez, Paula; Contreras-García, Julia; Cohen, Aron J.; Yang, Weitao

    2010-01-01

    Molecular structure does not easily identify the intricate non-covalent interactions that govern many areas of biology and chemistry, including design of new materials and drugs. We develop an approach to detect non-covalent interactions in real space, based on the electron density and its derivatives. Our approach reveals underlying chemistry that compliments the covalent structure. It provides a rich representation of van der Waals interactions, hydrogen bonds, and steric repulsion in small molecules, molecular complexes, and solids. Most importantly, the method, requiring only knowledge of the atomic coordinates, is efficient and applicable to large systems, such as proteins or DNA. Across these applications, a view of non-bonded interactions emerges as continuous surfaces rather than close contacts between atom pairs, offering rich insight into the design of new and improved ligands. PMID:20394428

  1. Rotational ratchets with dipolar interactions.

    PubMed

    Jäger, Sebastian; Klapp, Sabine H L

    2012-12-01

    We report results from a computer simulation study on the rotational ratchet effect in systems of magnetic particles interacting via dipolar interactions. The ratchet effect consists of directed rotations of the particles in an oscillating magnetic field, which lacks a net rotating component. Our investigations are based on Brownian dynamics simulations of such many-particle systems. We investigate the influence of both the random and deterministic contributions to the equations of motion on the ratchet effect. As a main result, we show that dipolar interactions can have an enhancing as well as a dampening effect on the ratchet behavior depending on the dipolar coupling strength of the system under consideration. The enhancement is shown to be caused by an increase in the effective field on a particle generated by neighboring magnetic particles, while the dampening is due to restricted rotational motion in the effective field. Moreover, we find a nontrivial influence of the short-range, repulsive interaction between the particles.

  2. Examples of Dietary Supplement Interactions

    MedlinePlus

    ... is absorbed by the body.Supplement: Saw PalmettoPossible drug-supplement interaction with:Birth control pills. Can decrease effects of estrogen in the body, which can reduce the effectiveness of birth control ...

  3. Creep-Fatigue Interaction Testing

    NASA Technical Reports Server (NTRS)

    Halford, Gary R.

    2001-01-01

    Fatigue fives in metals are nominally time independent below 0.5 T(sub Melt). At higher temperatures, fatigue lives are altered due to time-dependent, thermally activated creep. Conversely, creep rates are altered by super. imposed fatigue loading. Creep and fatigue generally interact synergistically to reduce material lifetime. Their interaction, therefore, is of importance to structural durability of high-temperature structures such as nuclear reactors, reusable rocket engines, gas turbine engines, terrestrial steam turbines, pressure vessel and piping components, casting dies, molds for plastics, and pollution control devices. Safety and lifecycle costs force designers to quantify these interactions. Analytical and experimental approaches to creep-fatigue began in the era following World War II. In this article experimental and life prediction approaches are reviewed for assessing creep-fatigue interactions of metallic materials. Mechanistic models are also discussed briefly.

  4. Intrapersonal Communication and Imagined Interactions.

    ERIC Educational Resources Information Center

    Honeycutt, James M.; And Others

    "Imagined interactions," which refer to a cognitive process whereby individuals imagine themselves having conversations with significant others, captures a dimension of intrapersonal communication barely understood by communication researchers. To examine this multifunctional concept, a study considered the role of "imagined…

  5. Refining Interaction Designs through Simplicity

    NASA Astrophysics Data System (ADS)

    Muñoz, Pablo; Giner, Pau; Pelechano, Vicente

    With more and more devices in our surroundings, users increasingly-consume applications and digital services which compete for their attention. Therefore, users appreciate simplicity when they interact with them because a less intrusive interaction allows users focus on the task at hand. This work relates an approach based on the concept of simplicity. We propose an iterative interaction design process in which we include a new role. This role is only in charge of providing simplified solutions from original designs. Moreover, we put on practice our proposal in a case study in which we design an application to support mobile workflows. We relate our experience and how new ideas were produced towards the definition of refactored interactions by means of the key of Simplicity.

  6. Fluctuations and interactions in microemulsions

    SciTech Connect

    Menes, R.; Safran, S.A.; Strey, R.

    1995-12-01

    We review the properties of microemulsions as described by an interfacial model which focuses upon the deformations of the surfactant monolayer separating mesoscopic water and oil domains. In some cases, the interfacial shape is well defined, resulting in a globular phase, while in others, the interface is strongly affected by thermal fluctuations, resulting in a random, sponge-like structure. In the globular phase, interactions between globules can result in phase coexistence comparable to those observed in polymeric systems. Recent experiments indicate that these interactions can result in closed-loop coexistence regions in the isothermal, concentration phase diagram. We propose a mechanism for this reentrant phase separation based on the combined effects of a shape transition and attractive interactions. Long cylindrical globules can phase separate at relatively low interglobular attractions. A transformation from elongated globules to compact spherical drops alters the balance between the entropy and the effective interglobule interactions, leading to the remixing of the globular system.

  7. InterAction Database (IADB)

    Cancer.gov

    The InterAction Database includes demographic and prescription information for more than 500,000 patients in the northern and middle Netherlands and has been integrated with other systems to enhance data collection and analysis.

  8. Spacecraft Environmental Interactions Technology, 1983

    NASA Technical Reports Server (NTRS)

    1985-01-01

    State of the art of environment interactions dealing with low-Earth-orbit plasmas; high-voltage systems; spacecraft charging; materials effects; and direction of future programs are contained in over 50 papers.

  9. Increasing Positive Interactive Classroom Behavior

    ERIC Educational Resources Information Center

    Kotcher, Elaine; Doremus, Richard R.

    1973-01-01

    The question examined in this study was as follows: do teachers increase their positive classroom interactive behaviors as a result of training in systematic classroom observation techniques? (Authors/JA)

  10. NP_PAH_interaction dataset

    EPA Pesticide Factsheets

    Concentrations of different polyaromatic hydrocarbons in water before and after interaction with nanomaterials. The results show the capacity of engineer nanomaterials for adsorbing different organic pollutants. This dataset is associated with the following publication:Sahle-Demessie, E., A. Zhao, C. Han, B. Hann, and H. Grecsek. Interaction of engineered nanomaterials with hydrophobic organic pollutants.. Journal of Nanotechnology. Hindawi Publishing Corporation, New York, NY, USA, 27(28): 284003, (2016).

  11. Dynamic interactions in neural networks

    SciTech Connect

    Arbib, M.A. ); Amari, S. )

    1989-01-01

    The study of neural networks is enjoying a great renaissance, both in computational neuroscience, the development of information processing models of living brains, and in neural computing, the use of neurally inspired concepts in the construction of intelligent machines. This volume presents models and data on the dynamic interactions occurring in the brain, and exhibits the dynamic interactions between research in computational neuroscience and in neural computing. The authors present current research, future trends and open problems.

  12. Multipurpose interactive NASA information system

    NASA Technical Reports Server (NTRS)

    Hill, J. M.; Keefer, R. L.; Sanders, D. R.; Seitz, R. N.

    1979-01-01

    Multipurpose Interactive NASA Information System (MINIS) is data management system capable of retrieving descriptive data from LANDSAT photos. General enough to be used with other user-defined data bases, interactive data management and information retrieval system was especially developed for small and medium-sized computers. It uses free-form data base that allows one to create entirely new and different data bases and to control format of output products.

  13. Interactional Psychology and Organizational Behavior.

    DTIC Science & Technology

    1982-02-01

    7 A0-A113 1132 MI1CHIGAN STATE UNIV EAST LANSING DEPT OF PSYCHOLOGY F/6 5/10 INTERACTIONAL PSYCHOLOGY AND ORGANIZATIONAL BEHA VIOR. (U) FEB 82 8...j INTERACTIONAL PSYCHOLOGY AND ORGANIZATIONAL BEHAVIOR Benjamin Schneider Research Report No. 82.1 February 1982 The writing of this paper was...supported in part by the Organizational Effectiveness Research Programs, Psychological Sciences Division, Office of Naval Research under Contract No. N00014

  14. Natural interaction for unmanned systems

    NASA Astrophysics Data System (ADS)

    Taylor, Glenn; Purman, Ben; Schermerhorn, Paul; Garcia-Sampedro, Guillermo; Lanting, Matt; Quist, Michael; Kawatsu, Chris

    2015-05-01

    Military unmanned systems today are typically controlled by two methods: tele-operation or menu-based, search-andclick interfaces. Both approaches require the operator's constant vigilance: tele-operation requires constant input to drive the vehicle inch by inch; a menu-based interface requires eyes on the screen in order to search through alternatives and select the right menu item. In both cases, operators spend most of their time and attention driving and minding the unmanned systems rather than on being a warfighter. With these approaches, the platform and interface become more of a burden than a benefit. The availability of inexpensive sensor systems in products such as Microsoft Kinect™ or Nintendo Wii™ has resulted in new ways of interacting with computing systems, but new sensors alone are not enough. Developing useful and usable human-system interfaces requires understanding users and interaction in context: not just what new sensors afford in terms of interaction, but how users want to interact with these systems, for what purpose, and how sensors might enable those interactions. Additionally, the system needs to reliably make sense of the user's inputs in context, translate that interpretation into commands for the unmanned system, and give feedback to the user. In this paper, we describe an example natural interface for unmanned systems, called the Smart Interaction Device (SID), which enables natural two-way interaction with unmanned systems including the use of speech, sketch, and gestures. We present a few example applications SID to different types of unmanned systems and different kinds of interactions.

  15. Interactive Astronomical Data Analysis Facility

    NASA Technical Reports Server (NTRS)

    Klinglesmith, D. A., III

    1980-01-01

    A description is given of the Interactive Astronomical Data Analysis Facility (IADAF) which performs interactive analysis of astronomical data for resident and visiting scientists. The facilities include a Grant measuring engine, a PDS 1010A microdensitometer, a COMTAL image display system and a PDP 11/40 computer system. Both hardware and software systems are examined, including a description of thirteen overlay programs. Some uses of the IADAF are indicated.

  16. Technology Adoption: an Interaction Perspective

    NASA Astrophysics Data System (ADS)

    Sitorus, Hotna M.; Govindaraju, Rajesri; Wiratmadja, I. I.; Sudirman, Iman

    2016-02-01

    The success of a new technology depends on how well it is accepted by its intended users. Many technologies face the problem of low adoption rate, despite the benefits. An understanding of what makes people accept or reject a new technology can help speed up the adoption rate. This paper presents a framework for technology adoption based on an interactive perspective, resulting from a literature study on technology adoption. In studying technology adoption, it is necessary to consider the interactions among elements involved in the system, for these interactions may generate new characteristics or new relationships. The interactions among elements in a system adoption have not received sufficient consideration in previous studies of technology adoption. Based on the proposed interaction perspective, technology adoption is elaborated by examining interactions among the individual (i.e. the user or prospective user), the technology, the task and the environment. The framework is formulated by adopting several theories, including Perceived Characteristics of Innovating, Diffusion of Innovation Theory, Technology Acceptance Model, Task-Technology Fit and usability theory. The proposed framework is illustrated in the context of mobile banking adoption. It is aimed to offer a better understanding of determinants of technology adoption in various contexts, including technology in manufacturing systems.

  17. Interactions of Amelogenin with Phospholipids

    PubMed Central

    Lokappa, Sowmya Bekshe; Chandrababu, Karthik Balakrishna; Dutta, Kaushik; Perovic, Iva; Evans, John Spencer; Moradian-Oldak, Janet

    2015-01-01

    Amelogenin protein has the potential to interact with other enamel matrix proteins, mineral and cell surfaces. We investigated the interactions of recombinant amelogenin rP172 with small unilamellar vesicles as model membranes, towards the goal of understanding the mechanisms of amelogenin-cell interactions during amelogenesis. Dynamic light scattering (DLS), fluorescence spectroscopy, circular dichroism (CD) and nuclear magnetic resonance (NMR) were used. In the presence of phospholipid vesicles, a blue shift in the Trp fluorescence emission maxima of rP172 was observed (~334 nm) and the Trp residues of rP172 were inaccessible to the aqueous quencher acrylamide. Though in DLS studies we cannot exclude the possibility of fusion of liposomes as the result of amelogenin addition, NMR and CD studies revealed a disorder-order transition of rP172 in a model membrane environment. Strong FRET from Trp in rP172 to DNS–bound-phospholipid was observed, and fluorescence polarization studies indicated that rP172 interacted with the hydrophobic core region of model membranes. Our data suggest that amelogenin has ability to interact with phospholipids and that such interactions may play key roles in enamel biomineralization as well as reported amelogenin signaling activities. PMID:25298002

  18. Warfarin interactions with medicinal herbs.

    PubMed

    Milić, Natasa; Milosević, Natasa; Golocorbin Kon, Svetlana; Bozić, Teodora; Abenavoli, Ludovico; Borrelli, Francesca

    2014-08-01

    Recognition of the adverse effects of medicinal herbs is not routine and the reports on such effects are even less frequent in clinical practice. Potential herb-drug interactions are of a major safety concern, especially for drugs with narrow therapeutic indices like warfarin, which can lead to severe adverse reactions that are sometimes life-threatening. The interactions between warfarin and medicinal herbs described in the literature have been summarized in this paper relying on Medline database (via PubMed) using the key words: warfarin, herbal supplements and interactions. The references on the analyzed literature have been investigated in order to collect the existing data. The case reports with severe adverse effects such as spontaneous postoperative bleeding, formation of hematomas, hematemesis, melena, thrombosis, subarachnoid hemorrhage and/or subdural hematomas after concomitant use of warfarin and the medicinal herbs: Panax ginseng, Hypericum perforatum, Salvia milthiorizza, Gingko biloba, Serenoa repens, Angelica sinensis, Vaccinium species, Allium sativum, Zingiber officinale, Tanacetum parthenium, Lucium barbarum, Matricaria chamomilla, Boswellia serrata and Camellia sinensis have been estimated. Some of the interactions between warfarin and medicinal herbs have been well assessed proving that they are closely-dependent. The interactions between warfarin and medicinal herbs, not generally reported in previous reviews, are presented in our review. The health professionals who are involved in treating the patients are expected to be fully informed about the interactions between warfarin and medicinal herbs in order to minimize the health risks of the patients.

  19. Measurement of interaction between antiprotons

    DOE PAGES

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

    2015-11-04

    In this paper, one of the primary goals of nuclear physics is to understand the force between nucleons, which is a necessary step for understanding the structure of nuclei and how nuclei interact with each other. Rutherford discovered the atomic nucleus in 1911, and the large body of knowledge about the nuclear force that has since been acquired was derived from studies made on nucleons or nuclei. Although antinuclei up to antihelium-4 have been discovered and their masses measured, little is known directly about the nuclear force between antinucleons. Here, we study antiproton pair correlations among data collected by themore » STAR experiment at the Relativistic Heavy Ion Collider (RHIC), where gold ions are collided with a centre-of-mass energy of 200 gigaelectronvolts per nucleon pair. Antiprotons are abundantly produced in such collisions, thus making it feasible to study details of the antiproton–antiproton interaction. By applying a technique similar to Hanbury Brown and Twiss intensity interferometry, we show that the force between two antiprotons is attractive. In addition, we report two key parameters that characterize the corresponding strong interaction: the scattering length and the effective range of the interaction. Our measured parameters are consistent within errors with the corresponding values for proton–proton interactions. Our results provide direct information on the interaction between two antiprotons, one of the simplest systems of antinucleons, and so are fundamental to understanding the structure of more-complex antinuclei and their properties.« less

  20. Measurement of interaction between antiprotons

    NASA Astrophysics Data System (ADS)

    The Star Collaboration; Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de La Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; de Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Klein, S.; Kochenda, L.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, Z. M.; Li, Y.; Li, W.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R.; Ma, Y. G.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, M. K.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, Z.; Sun, X. M.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Y.; Wang, Y.; Wang, F.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Y. F.; Xu, Q. H.; Xu, H.; Xu, N.; Xu, Z.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Z.; Zhang, J.; Zhang, S.; Zhang, X. P.; Zhang, J.; Zhang, Y.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.

    2015-11-01

    One of the primary goals of nuclear physics is to understand the force between nucleons, which is a necessary step for understanding the structure of nuclei and how nuclei interact with each other. Rutherford discovered the atomic nucleus in 1911, and the large body of knowledge about the nuclear force that has since been acquired was derived from studies made on nucleons or nuclei. Although antinuclei up to antihelium-4 have been discovered and their masses measured, little is known directly about the nuclear force between antinucleons. Here, we study antiproton pair correlations among data collected by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC), where gold ions are collided with a centre-of-mass energy of 200 gigaelectronvolts per nucleon pair. Antiprotons are abundantly produced in such collisions, thus making it feasible to study details of the antiproton-antiproton interaction. By applying a technique similar to Hanbury Brown and Twiss intensity interferometry, we show that the force between two antiprotons is attractive. In addition, we report two key parameters that characterize the corresponding strong interaction: the scattering length and the effective range of the interaction. Our measured parameters are consistent within errors with the corresponding values for proton-proton interactions. Our results provide direct information on the interaction between two antiprotons, one of the simplest systems of antinucleons, and so are fundamental to understanding the structure of more-complex antinuclei and their properties.

  1. Interactions of amelogenin with phospholipids

    SciTech Connect

    Bekshe Lokappa, Sowmya; Chandrababu, Karthik Balakrishna; Dutta, Kaushik; Perovic, Iva; Evans, John Spencer; Moradian-Oldak, Janet

    2014-11-22

    Amelogenin protein has the potential to interact with other enamel matrix proteins, mineral, and cell surfaces. In this paper, we investigated the interactions of recombinant amelogenin rP172 with small unilamellar vesicles as model membranes, toward the goal of understanding the mechanisms of amelogenin–cell interactions during amelogenesis. Dynamic light scattering (DLS), fluorescence spectroscopy, circular dichroism (CD), and nuclear magnetic resonance (NMR) were used. In the presence of phospholipid vesicles, a blue shift in the Trp fluorescence emission maxima of rP172 was observed (~334 nm) and the Trp residues of rP172 were inaccessible to the aqueous quencher acrylamide. DLS studies indicated complexation of rP172 and phospholipids, although the possibility of fusion of phospholipids following amelogenin addition cannot be ruled out. NMR and CD studies revealed a disorder–order transition of rP172 in a model membrane environment. Strong fluorescence resonance energy transfer from Trp in rP172 to DNS-bound-phospholipid was observed, and fluorescence polarization studies indicated that rP172 interacted with the hydrophobic core region of model membranes. Finally, our data suggest that amelogenin has ability to interact with phospholipids and that such interactions may play key roles in enamel biomineralization as well as reported amelogenin signaling activities.

  2. Interactions of amelogenin with phospholipids

    DOE PAGES

    Bekshe Lokappa, Sowmya; Chandrababu, Karthik Balakrishna; Dutta, Kaushik; ...

    2014-11-22

    Amelogenin protein has the potential to interact with other enamel matrix proteins, mineral, and cell surfaces. In this paper, we investigated the interactions of recombinant amelogenin rP172 with small unilamellar vesicles as model membranes, toward the goal of understanding the mechanisms of amelogenin–cell interactions during amelogenesis. Dynamic light scattering (DLS), fluorescence spectroscopy, circular dichroism (CD), and nuclear magnetic resonance (NMR) were used. In the presence of phospholipid vesicles, a blue shift in the Trp fluorescence emission maxima of rP172 was observed (~334 nm) and the Trp residues of rP172 were inaccessible to the aqueous quencher acrylamide. DLS studies indicated complexationmore » of rP172 and phospholipids, although the possibility of fusion of phospholipids following amelogenin addition cannot be ruled out. NMR and CD studies revealed a disorder–order transition of rP172 in a model membrane environment. Strong fluorescence resonance energy transfer from Trp in rP172 to DNS-bound-phospholipid was observed, and fluorescence polarization studies indicated that rP172 interacted with the hydrophobic core region of model membranes. Finally, our data suggest that amelogenin has ability to interact with phospholipids and that such interactions may play key roles in enamel biomineralization as well as reported amelogenin signaling activities.« less

  3. Measurement of interaction between antiprotons

    SciTech Connect

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Klein, S.; Kochenda, L.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, Z. M.; Li, Y.; Li, W.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R.; Ma, Y. G.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, M. K.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, Z.; Sun, X. M.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Y.; Wang, Y.; Wang, F.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Y. F.; Xu, Q. H.; Xu, H.; Xu, N.; Xu, Z.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I. -K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Z.; Zhang, J.; Zhang, S.; Zhang, X. P.; Zhang, J.; Zhang, Y.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.

    2015-11-04

    In this paper, one of the primary goals of nuclear physics is to understand the force between nucleons, which is a necessary step for understanding the structure of nuclei and how nuclei interact with each other. Rutherford discovered the atomic nucleus in 1911, and the large body of knowledge about the nuclear force that has since been acquired was derived from studies made on nucleons or nuclei. Although antinuclei up to antihelium-4 have been discovered and their masses measured, little is known directly about the nuclear force between antinucleons. Here, we study antiproton pair correlations among data collected by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC), where gold ions are collided with a centre-of-mass energy of 200 gigaelectronvolts per nucleon pair. Antiprotons are abundantly produced in such collisions, thus making it feasible to study details of the antiproton–antiproton interaction. By applying a technique similar to Hanbury Brown and Twiss intensity interferometry, we show that the force between two antiprotons is attractive. In addition, we report two key parameters that characterize the corresponding strong interaction: the scattering length and the effective range of the interaction. Our measured parameters are consistent within errors with the corresponding values for proton–proton interactions. Our results provide direct information on the interaction between two antiprotons, one of the simplest systems of antinucleons, and so are fundamental to understanding the structure of more-complex antinuclei and their properties.

  4. Environmental interactions in space exploration: Environmental interactions working group

    NASA Technical Reports Server (NTRS)

    Kolecki, Joseph C.; Hillard, G. Barry

    1992-01-01

    With the advent of the Space Exploration Initiative, the possibility of designing and using systems on scales heretofore unattempted presents exciting new challenges in systems design and space science. The environments addressed by the Space Exploration Initiative include the surfaces of the Moon and Mars, as well as the varied plasma and field environments which will be encountered by humans and cargo enroute to these destinations. Systems designers will need to understand environmental interactions and be able to model these mechanisms from the earliest conceptual design stages through design completion. To the end of understanding environmental interactions and establishing robotic precursor mission requirements, an Environmental Interactions Working Group was established as part of the Robotic Missions Working Group. The working group is described, and its current activities are updated.

  5. Information capacity of specific interactions

    PubMed Central

    Huntley, Miriam H.; Murugan, Arvind; Brenner, Michael P.

    2016-01-01

    Specific interactions are a hallmark feature of self-assembly and signal-processing systems in both synthetic and biological settings. Specificity between components may arise from a wide variety of physical and chemical mechanisms in diverse contexts, from DNA hybridization to shape-sensitive depletion interactions. Despite this diversity, all systems that rely on interaction specificity operate under the constraint that increasing the number of distinct components inevitably increases off-target binding. Here we introduce “capacity,” the maximal information encodable using specific interactions, to compare specificity across diverse experimental systems and to compute how specificity changes with physical parameters. Using this framework, we find that “shape” coding of interactions has higher capacity than chemical (“color”) coding because the strength of off-target binding is strongly sublinear in binding-site size for shapes while being linear for colors. We also find that different specificity mechanisms, such as shape and color, can be combined in a synergistic manner, giving a capacity greater than the sum of the parts. PMID:27155013

  6. Drug interactions and the statins

    PubMed Central

    Herman, R J

    1999-01-01

    Drug interactions commonly occur in patients receiving treatment with multiple medications. Most interactions remain unrecognized because drugs, in general, have a wide margin of safety or because the extent of change in drug levels is small when compared with the variation normally seen in clinical therapy. All drug interactions have a pharmacokinetic or pharmacodynamic basis and are predictable given an understanding of the pharmacology of the drugs involved. Drugs most liable to pose problems are those having concentration-dependent toxicity within, or close to, the therapeutic range; those with steep dose-response curves; those having high first-pass metabolism or those with a single, inhibitable route of elimination. Knowing which drugs possess these intrinsic characteristics, together with a knowledge of hepatic P-450 metabolism and common enzyme-inducing and enzyme-inhibiting drugs, can greatly assist physicians in predicting interactions that may be clinically relevant. This article reviews the pharmacology of drug interactions that can occur with hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) to illustrate the scope of the problem and the ways in which physicians may manage this important therapeutic class of drugs. PMID:10584091

  7. Field Theory of Fundamental Interactions

    NASA Astrophysics Data System (ADS)

    Wang, Shouhong; Ma, Tian

    2017-01-01

    First, we present two basic principles, the principle of interaction dynamics (PID) and the principle of representation invariance (PRI). Intuitively, PID takes the variation of the action under energy-momentum conservation constraint. We show that the PID is the requirement of the presence of dark matter and dark energy, the Higgs field and the quark confinement. PRI requires that the SU(N) gauge theory be independent of representations of SU(N). It is clear that PRI is the logic requirement of any gauge theory. With PRI, we demonstrate that the coupling constants for the strong and the weak interactions are the main sources of these two interactions, reminiscent of the electric charge. Second, we emphasize that symmetry principles-the principle of general relativity and the principle of Lorentz invariance and gauge invariance-together with the simplicity of laws of nature, dictate the actions for the four fundamental interactions. Finally, we show that the PID and the PRI, together with the symmetry principles give rise to a unified field model for the fundamental interactions, which is consistent with current experimental observations and offers some new physical predictions. The research is supported in part by the National Science Foundation (NSF) grant DMS-1515024, and by the Office of Naval Research (ONR) grant N00014-15-1-2662.

  8. Motor interference in interactive contexts

    PubMed Central

    Chinellato, Eris; Castiello, Umberto; Sartori, Luisa

    2015-01-01

    Action observation and execution share overlapping neural substrates, so that simultaneous activation by observation and execution modulates motor performance. Previous literature on simple prehension tasks has revealed that motor influence can be two-sided: facilitation for observed and performed congruent actions and interference for incongruent actions. But little is known of the specific modulations of motor performance in complex forms of interaction. Is it possible that the very same observed movement can lead either to interference or facilitation effects on a temporally overlapping congruent executed action, depending on the context? To answer this question participants were asked to perform a reach-to-grasp movement adopting a precision grip (PG) while: (i) observing a fixation cross, (ii) observing an actor performing a PG with interactive purposes, (iii) observing an actor performing a PG without interactive purposes. In particular, in the interactive condition the actor was shown trying to pour some sugar on a large cup located out of her reach but close to the participant watching the video, thus eliciting in reaction a complementary whole-hand grasp. Notably, fine-grained kinematic analysis for this condition revealed a specific delay in the grasping and reaching components and an increased trajectory deviation despite the observed and executed movement’s congruency. Moreover, early peaks of trajectory deviation seem to indicate that socially relevant stimuli are acknowledged by the motor system very early. These data suggest that interactive contexts can determine a prompt modulation of stimulus–response compatibility effects. PMID:26113835

  9. Platelet interaction with polymerizing fibrin.

    PubMed

    Niewiarowski, S; Regoeczi, E; Stewart, G J; Senyl, A F; Mustard, J F

    1972-03-01

    Interaction of washed pig, rabbit, or human platelets with fibrinogen was studied during its transition to fibrin using photometric, isotopic, and electron microscopic techniques. Untreated fibrinogen and fully polymerized fibrin had no detectable effect on platelets. Fibrinogen, incubated with low concentrations of reptilase or thrombin, formed intermediate products which readily became associated with platelets and caused their aggregation. Neutralization of the thrombin did not prevent this interaction. In the absence of fibrinogen, reptilase did not affect platelets. The interaction of polymerizing fibrin with platelets was accompanied by small losses of platelet constituents (serotonin, adenine nucleotides, platelet factor 4, and lactic dehydrogenase). This loss did not appear to be the result of the platelet release reaction. Inhibitors of the release reaction or of adenosine diphosphate (ADP)-induced aggregation did not prevent the interaction of platelets with polymerizing fibrin. Apyrase or prostaglandin E(1) (PGE(1)) reduced the extent of platelet aggregation by polymerizing fibrin, but the amount of protein associated with platelets was slightly increased. The interaction of polymerizing fibrin with platelets was completely inhibited by ethylenediaminetetraacetate (EDTA) or ethylene glycol bis (beta-aminoethyl ether) N, N,N',N'-tetraacetic acid (EGTA).Fibers formed in solutions of polymerizing fibrin were larger in the presence than in the absence of washed platelets, suggesting that platelets affect fibrin polymerization. The adherence of platelets to polymerizing fibrin may be responsible for the establishment of links between platelets and fibrin in hemostatic plugs and thrombi.

  10. Intermolecular interactions in solid benzene.

    PubMed

    Kearley, G J; Johnson, M R; Tomkinson, J

    2006-01-28

    The lattice dynamics and molecular vibrations of benzene and deuterated benzene crystals are calculated from force constants derived from density-functional theory (DFT) calculations and compared with measured inelastic neutron-scattering spectra. A very small change (0.5%) in lattice parameter is required to obtain real lattice-mode frequencies across the Brillouin zone. There is a strong coupling between wagging and breathing modes away from the zone center. This coupling and sensitivity to cell size arises from two basic interactions. Firstly, comparatively strong interactions that hold the benzene molecules together in layers. These include an intermolecular interaction in which H atoms of one molecule link to the center of the aromatic ring of a neighboring molecule. The layers are held to each other by weaker interactions, which also have components that hold molecules together within a layer. Small changes in the lattice parameters change this second type of interaction and account for the changes to the lattice dynamics. The calculations also reveal a small auxetic effect in that elongation of the crystal along the b axis leads to an increase in internal pressure in the ac plane, that is, elongation in the b direction induces expansion in the a and c directions.

  11. HIV Treatment: What is a Drug Interaction?

    MedlinePlus

    ... HIV Treatment Services HIV Treatment What is a Drug Interaction? (Last updated 3/13/2017; last reviewed ... taking or plan to take. What is a drug interaction? A drug interaction is a reaction between ...

  12. Bacterial Communities: Interactions to Scale

    PubMed Central

    Stubbendieck, Reed M.; Vargas-Bautista, Carol; Straight, Paul D.

    2016-01-01

    In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities. PMID:27551280

  13. Stacking interactions and DNA intercalation

    SciTech Connect

    Li, Dr. Shen; Cooper, Valentino R; Thonhauser, Prof. Timo; Lundqvist, Prof. Bengt I.; Langreth, David C.

    2009-01-01

    The relationship between stacking interactions and the intercalation of proflavine and ellipticine within DNA is investigated using a nonempirical van der Waals density functional for the correlation energy. Our results, employing a binary stack model, highlight fundamental, qualitative differences between base-pair base-pair interactions and that of the stacked intercalator base pair system. Most notable result is the paucity of torque which so distinctively defines the Twist of DNA. Surprisingly, this model, when combined with a constraint on the twist of the surrounding base-pair steps to match the observed unwinding of the sugar-phosphate backbone, was sufficient for explaining the experimentally observed proflavine intercalator configuration. Our extensive mapping of the potential energy surface of base-pair intercalator interactions can provide valuable information for future nonempirical studies of DNA intercalation dynamics.

  14. Quantum simulation with interacting photons

    NASA Astrophysics Data System (ADS)

    Hartmann, Michael J.

    2016-10-01

    Enhancing optical nonlinearities so that they become appreciable on the single photon level and lead to nonclassical light fields has been a central objective in quantum optics for many years. After this has been achieved in individual micro-cavities representing an effectively zero-dimensional volume, this line of research has shifted its focus towards engineering devices where such strong optical nonlinearities simultaneously occur in extended volumes of multiple nodes of a network. Recent technological progress in several experimental platforms now opens the possibility to employ the systems of strongly interacting photons, these give rise to as quantum simulators. Here we review the recent development and current status of this research direction for theory and experiment. Addressing both, optical photons interacting with atoms and microwave photons in networks of superconducting circuits, we focus on analogue quantum simulations in scenarios where effective photon-photon interactions exceed dissipative processes in the considered platforms.

  15. Interactive autonomy and robotic skills

    NASA Technical Reports Server (NTRS)

    Kellner, A.; Maediger, B.

    1994-01-01

    Current concepts of robot-supported operations for space laboratories (payload servicing, inspection, repair, and ORU exchange) are mainly based on the concept of 'interactive autonomy' which implies autonomous behavior of the robot according to predefined timelines, predefined sequences of elementary robot operations and within predefined world models supplying geometrical and other information for parameter instantiation on the one hand, and the ability to override and change the predefined course of activities by human intervention on the other hand. Although in principle a very powerful and useful concept, in practice the confinement of the robot to the abstract world models and predefined activities appears to reduce the robot's stability within real world uncertainties and its applicability to non-predefined parts of the world, calling for frequent corrective interaction by the operator, which in itself may be tedious and time-consuming. Methods are presented to improve this situation by incorporating 'robotic skills' into the concept of interactive autonomy.

  16. Global forcing and regional interactions

    USGS Publications Warehouse

    1992-01-01

    The Climate System Modeling Program (CSMP) sponsored a “Global Forcing and Regional Interaction Workshop” from October 21 to 23, 1991, at Colorado State University's Pingree Park campus, to evaluate the relationship between global climate forcing and the response of the land surface on a regional scale. The general aim of the workshop was to develop specific action plans and preliminary science research strategies for regional-global interactions. Each participant was invited to identify tractable, high pay-off science issues related to global forcing and regional interactions. The workshop, with twenty-six participants about evenly split between atmospheric scientists, hydrologists, and ecologists, was also designed to facilitate a network of collaborators to prepare multidisciplinary research proposals. Discussion also focused on regional climate over the last 200 years and included the influence of atmosphere-land surface processes on natural climate variability. Several major recommendations were made on topics discussed.

  17. Fluctuating hyperfine interactions: computational implementation

    NASA Astrophysics Data System (ADS)

    Zacate, M. O.; Evenson, W. E.

    2010-04-01

    A library of computational routines has been created to assist in the analysis of stochastic models of hyperfine interactions. We call this library the stochastic hyperfine interactions modeling library (SHIML). It provides routines written in the C programming language that (1) read a text description of a model for fluctuating hyperfine fields, (2) set up the Blume matrix, upon which the evolution operator of the system depends, and (3) find the eigenvalues and eigenvectors of the Blume matrix so that theoretical spectra of experimental hyperfine interaction measurements can be calculated. Example model calculations are included in the SHIML package to illustrate its use and to generate perturbed angular correlation spectra for the special case of polycrystalline samples when anisotropy terms of higher order than A22 can be neglected.

  18. Studies of food drug interactions.

    PubMed

    Aman, Syed Faisal; Hassan, Fouzia; Naqvi, Baqar S; Hasan, Syed Muhammmad Farid

    2010-07-01

    Medicines can treat and alleviate many diseases provided that they must be taken properly to ensure that they are safe and useful. One issue related with the medicines is that whether to take on empty stomach or with food. The present work gives information regarding food-drug interactions that were studied by collecting seventy five prescriptions from various hospitals. In most of the collected prescriptions, food-drug interactions were detected using the literature available. It was also found that only few studies have been carried out so far on the effect of food on drug disposition in the Asian population. Thus more studies on food-drug interactions particularly in the local population is recommended in order to determine the effect of food and food components on drug disposition and to the kinetics of the drugs which has not yet well highlighted in this part of the world.

  19. Interactions between comoving magnetic microswimmers.

    PubMed

    Keaveny, Eric E; Maxey, Martin R

    2008-04-01

    The artificial microswimmer [R. Dreyfus, Nature (London) 437, 862 (2005)] whose mechanism of propulsion is the magnetically driven undulation of a flagellum-like tail composed of chemically linked paramagnetic beads can be used as a physical model with which to study low-Reynolds-number swimming. Understanding how such swimmers interact provides insight into the related problem of quantifying the hydrodynamic interactions between microorganisms. In this study, particle-based numerical simulations are conducted of two comoving artificial swimmers. The resulting swimming speeds are determined over a range of separations for swimmers driven by planar and rotational magnetic fields. The far-field hydrodynamic interactions are analyzed and found to decay as h(-2) where h is the separation distance. Additionally, the role of the interswimmer magnetic forces is determined.

  20. Hadronization processes in neutrino interactions

    SciTech Connect

    Katori, Teppei; Mandalia, Shivesh

    2015-10-15

    Next generation neutrino oscillation experiments utilize details of hadronic final states to improve the precision of neutrino interaction measurements. The hadronic system was often neglected or poorly modelled in the past, but they have significant effects on high precision neutrino oscillation and cross-section measurements. Among the physics of hadronic systems in neutrino interactions, the hadronization model controls multiplicities and kinematics of final state hadrons from the primary interaction vertex. For relatively high invariant mass events, many neutrino experiments rely on the PYTHIA program. Here, we show a possible improvement of this process in neutrino event generators, by utilizing expertise from the HERMES experiment. Finally, we estimate the impact on the systematics of hadronization models for neutrino mass hierarchy analysis using atmospheric neutrinos such as the PINGU experiment.

  1. Hairpin Vortices: Autogeneration and Interaction

    NASA Astrophysics Data System (ADS)

    Sabatino, Daniel; Maharjan, Rijan; Sanders, Andrew

    2013-11-01

    The regeneration of hairpin vortices is examined in a free-surface water channel where vortices are artificially generated by means of injection in a laminar boundary layer. The process is visualized with dye and hydrogen bubble-wire techniques. The strength of an isolated hairpin required to begin the autogeneration process is established by means of PIV measurements on the symmetry plane. Because hairpins are in close proximity in a fully-turbulent boundary layer, two hairpins are generated at different streamwise locations and allowed to interact at different stages of development. The relative position, strength and maturity of the interacting hairpins that generate secondary vortices are examined. The morphology of the generation process and of the resulting secondary hairpin for both the isolated and interacting cases are discussed and compared to previous work. Supported by the National Science Foundation under Grant CBET-1040236.

  2. Atmospheric-wake vortex interactions

    NASA Technical Reports Server (NTRS)

    Bilanin, A. J.; Hirsh, J. E.; Teske, M. E.; Hecht, A. M.

    1978-01-01

    The interactions of a vortex wake with a turbulent stratified atmosphere are investigated with the computer code WAKE. It is shown that atmospheric shear, turbulence, and stratification can provide the dominant mechanisms by which vortex wakes decay. Computations included the interaction of a vortex wake with a viscous ground plane. The observed phenomenon of vortex bounce is explained in terms of secondary vorticity produced on the ground. This vorticity is swept off the ground and advected about the vortex pair, thereby altering the classic hyperbolic trajectory. The phenomenon of the solitary vortex is explained as an interaction of a vortex with crosswind shear. Here, the vortex having the sign opposite that of the sign of the vorticity in the shear is dispersed by a convective instability. This instability results in the rapid production of turbulence which in turn disperses the smoke marking the vortex.

  3. The nitrogen cycle: Atmosphere interactions

    NASA Technical Reports Server (NTRS)

    Levine, J. S.

    1984-01-01

    Atmospheric interactions involving the nitrogen species are varied and complex. These interactions include photochemical reactions, initiated by the absorption of solar photons and chemical kinetic reactions, which involve both homogeneous (gas-to-gas reactions) and heterogeneous (gas-to-particle) reactions. Another important atmospheric interaction is the production of nitrogen oxides by atmospheric lightning. The nitrogen cycle strongly couples the biosphere and atmosphere. Many nitrogen species are produced by biogenic processes. Once in the atmosphere nitrogen oxides are photochemically and chemically transformed to nitrates, which are returned to the biosphere via precipitation, dry deposition and aerosols to close the biosphere-atmosphere nitrogen cycle. The sources, sinks and photochemistry/chemistry of the nitrogen species; atmospheric nitrogen species; souces and sinks of nitrous oxide; sources; sinks and photochemistry/chemistry of ammonia; seasonal variation of the vertical distribution of ammonia in the troposphere; surface and atmospheric sources of the nitrogen species, and seasonal variation of ground level ammonia are summarized.

  4. Dispersive interactions in graphitic nanostructures

    NASA Astrophysics Data System (ADS)

    Woods, L. M.; Popescu, A.; Drosdoff, D.; Bondarev, I. V.

    2013-02-01

    The Casimir interaction between graphitic nanostructures, such as carbon nanotubes and graphene sheets, is investigated at the quantum mechanical limit (T = 0 K) using a quantum electrodynamical approach for absorbing and dispersive media. It is found that the nanotube/nanotube interaction in a double wall carbon nanotube configuration is profoundly affected by the collective low frequency excitations of individual nanotubes. It is shown that pronounced, low frequency peaks in the nanotube electron energy loss spectra are a main factor contributing to the strength of the intertube attraction. The graphene/graphene force is also investigated. It is obtained that the graphene optical transparency is the main reason for the reduced attraction as compared to the one for perfect metals. This study presents a unified approach for electromagnetic interactions in graphitic nanostructures, which is able to account for their unique electronic and response properties and geometry configurations.

  5. Adolescent girls' parasocial interactions with media figures.

    PubMed

    Theran, Sally A; Newberg, Emily M; Gleason, Tracy R

    2010-01-01

    We examined aspects of adolescent girls' parasocial interactions in the context of typical development. Parasocial interactions are defined as symbolic, one-sided quasi-interactions between a viewer and a media figure. In total, 107 adolescent girls were examined; 94% reported engaging in parasocial interactions to some degree. Preoccupied attachment style predicted the degree of involvement in and emotional intensity of parasocial interactions. Results suggest that parasocial interactions are characteristic of girls with preoccupied attachment, but are also part of normative development.

  6. Interactional Feedback in Naturalistic Interaction between L2 English Learners

    ERIC Educational Resources Information Center

    Ranaweera, Mahishi

    2015-01-01

    Theoretical and empirical data support that the feedback given in small group activities promote second language acquisition. There are many studies that have examined the impact of interaction on second language acquisition in controlled language situations. This study examines the small group activity "conversation partner" in order to…

  7. PCorral--interactive mining of protein interactions from MEDLINE.

    PubMed

    Li, Chen; Jimeno-Yepes, Antonio; Arregui, Miguel; Kirsch, Harald; Rebholz-Schuhmann, Dietrich

    2013-01-01

    The extraction of information from the scientific literature is a complex task-for researchers doing manual curation and for automatic text processing solutions. The identification of protein-protein interactions (PPIs) requires the extraction of protein named entities and their relations. Semi-automatic interactive support is one approach to combine both solutions for efficient working processes to generate reliable database content. In principle, the extraction of PPIs can be achieved with different methods that can be combined to deliver high precision and/or high recall results in different combinations at the same time. Interactive use can be achieved, if the analytical methods are fast enough to process the retrieved documents. PCorral provides interactive mining of PPIs from the scientific literature allowing curators to skim MEDLINE for PPIs at low overheads. The keyword query to PCorral steers the selection of documents, and the subsequent text analysis generates high recall and high precision results for the curator. The underlying components of PCorral process the documents on-the-fly and are available, as well, as web service from the Whatizit infrastructure. The human interface summarizes the identified PPI results, and the involved entities are linked to relevant resources and databases. Altogether, PCorral serves curator at both the beginning and the end of the curation workflow for information retrieval and information extraction. Database URL: http://www.ebi.ac.uk/Rebholz-srv/pcorral.

  8. Interactive Whiteboards: Do Teachers Really Use Them Interactively?

    ERIC Educational Resources Information Center

    Tatli, Cemal; Kiliç, Eylem

    2016-01-01

    The aim of this quantitative study is to examine high school teachers' use of specific features of interactive whiteboards (IWBs). During the 2012-2013 academic school year, 535 teachers in pilot schools from 10 provinces under the FATIH Project (Movement of Enhancing Opportunities and Improving Technology) participated. Data were collected…

  9. Light and noise pollution interact to disrupt interspecific interactions.

    PubMed

    McMahon, Taegan A; Rohr, Jason R; Bernal, Ximena E

    2017-02-07

    Studies on the consequences of urbanization often examine the effects of light, noise, and heat pollution independently on isolated species providing a limited understanding of how these combined stressors affect species interactions. Here, we investigate how these factors interact to affect parasitic frog-biting midges (Corethrella spp.) and their túngara frog (Engystomops pustulosus) hosts. A survey of túngara frog calling sites revealed that frog abundance was not significantly correlated with urbanization, light, noise, or temperature. In contrast, frog-biting midges were sensitive to light pollution and noise pollution. Increased light intensity significantly reduced midge abundance at low noise levels. At high noise intensity, there were no midges regardless of light level. Two field experiments controlling light and noise levels to examine attraction of the midges to their host and their feeding behavior confirmed the causality of these field patterns. These findings demonstrate that both light and noise pollution disrupt this host-parasite interaction and highlight the importance of considering interactions among species and types of pollutants to accurately assess the impacts of urbanization on ecological communities. This article is protected by copyright. All rights reserved.

  10. Participant Interaction in Asynchronous Learning Environments: Evaluating Interaction Analysis Methods

    ERIC Educational Resources Information Center

    Blanchette, Judith

    2012-01-01

    The purpose of this empirical study was to determine the extent to which three different objective analytical methods--sequence analysis, surface cohesion analysis, and lexical cohesion analysis--can most accurately identify specific characteristics of online interaction. Statistically significant differences were found in all points of…

  11. Anesthetics interacting with lipid rafts.

    PubMed

    Bandeiras, Cátia; Serro, Ana Paula; Luzyanin, Konstantin; Fernandes, Anabela; Saramago, Benilde

    2013-01-23

    The exact mechanism by which anesthetics induce cell membrane-mediated modifications is still an open question. Although the fluidization effect of the anesthetic molecules on the cellular membrane is widely recognized, it is not known if anesthetics show any preference for specific membrane domains, namely the lipid rafts. The importance of these membrane micro-domains derives from the fact that they have been associated with cell signaling pathways, as well as with specific drug interactions. The objective of this work is to contribute for the elucidation of this question through the comparison of the anesthetic interactions with membranes of various lipid compositions. Liposomes prepared with an equimolar mixture of POPC, sphingomyelin and cholesterol, were chosen as models for lipid rafts. The interactions of these liposomes with two local anesthetics, tetracaine and lidocaine, and one general anesthetic, propofol, were studied. The effect of cholesterol was investigated by comparing anesthetic interactions with POPC/SM liposomes and POPC/SM/CHOL liposomes. The following experimental techniques were used: quartz crystal microbalance with dissipation, differential scanning calorimetry and phosphorus nuclear magnetic resonance. Although the liposomes investigated by the different techniques are not in the same conditions, it is possible to assemble the information obtained from all experimental techniques employed to reach a general conclusion. Tetracaine interacts more with raftlike domains, lidocaine induces stronger modifications on POPC/SM liposomes and the results for propofol are not fully conclusive but it seems to be the least prone to lipid interactions. The results were compared with those obtained with DMPC-containing liposomes, reported in a previous work.

  12. Generalized interaction-free evolutions

    NASA Astrophysics Data System (ADS)

    Militello, Benedetto; Chruściński, Dariusz; Messina, Antonino; NaleŻyty, Paweł; Napoli, Anna

    2016-02-01

    A thorough analysis of the evolutions of bipartite systems characterized by the "effective absence" of interaction between the two subsystems is reported. First, the connection between the concepts underlying interaction-free evolutions (IFE) and decoherence-free subspaces (DFS) is explored, showing intricate relations between these concepts. Second, starting from this analysis and inspired by a generalization of DFS already known in the literature, we introduce the notion of generalized IFE (GIFE), also providing a useful characterization that allows one to develop a general scheme for finding GIFE states.

  13. Models of dyadic social interaction.

    PubMed Central

    Griffin, Dale; Gonzalez, Richard

    2003-01-01

    We discuss the logic of research designs for dyadic interaction and present statistical models with parameters that are tied to psychologically relevant constructs. Building on Karl Pearson's classic nineteenth-century statistical analysis of within-organism similarity, we describe several approaches to indexing dyadic interdependence and provide graphical methods for visualizing dyadic data. We also describe several statistical and conceptual solutions to the 'levels of analytic' problem in analysing dyadic data. These analytic strategies allow the researcher to examine and measure psychological questions of interdependence and social influence. We provide illustrative data from casually interacting and romantic dyads. PMID:12689382

  14. Interaction of two dielectric macroparticles

    SciTech Connect

    Munirov, V. R.; Filippov, A. V.

    2013-11-15

    The electrostatic interaction of two charged dielectric spherical particles with a nonuniform freecharge distribution over their surfaces in an external homogeneous electric field is considered. An exact solution for the electric field potential is obtained, and an analytical expression for the interaction force between these two particles is found. The case of a uniform free-charge distribution is considered in detail, and the region of parameters in the plane “the ratio of the radii vs. the ratio of the charges,” where repulsion between two like-charged particles turns into attraction as the interparticle distance decreases is established.

  15. Orbital, Rotational, and Climatic Interactions

    NASA Technical Reports Server (NTRS)

    Bills, Bruce G. (Editor)

    1992-01-01

    The report of an international meeting on the topic of Orbital, Rotational, and Climatic Interactions, which was held 9-11 Jul. 1991 at the Johns Hopkins University is presented. The meeting was attended by 22 researchers working on various aspects of orbital and rotational dynamics, paleoclimate data analysis and modeling, solid-Earth deformation studies, and paleomagnetic analyses. The primary objective of the workshop was to arrive at a better understanding of the interactions between the orbital, rotational, and climatic variations of the Earth. This report contains a brief introduction and 14 contributed papers which cover most of the topics discussed at the meeting.

  16. Cosmology and the weak interaction

    NASA Technical Reports Server (NTRS)

    Schramm, David N.

    1989-01-01

    The weak interaction plays a critical role in modern Big Bang cosmology. Two of its most publicized comological connections are emphasized: big bang nucleosynthesis and dark matter. The first of these is connected to the cosmological prediction of neutrine flavors, N(sub nu) is approximately 3 which in now being confirmed. The second is interrelated to the whole problem of galacty and structure formation in the universe. The role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure is demonstrated.

  17. Cosmology and the weak interaction

    SciTech Connect

    Schramm, D.N. ):)

    1989-12-01

    The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N{sub {nu}} {approximately} 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs.

  18. Connecting interacting galaxies with manifolds

    NASA Astrophysics Data System (ADS)

    Romero-Gomez, M.; Athanassoula, E.

    2017-03-01

    It is well known that the interaction between two disk galaxies generates tidal spiral arms and a connection in the form of a bridge. Here we address the question of the formation of tidal arms and bridges from a dynamical point of view. We model the bridges and tails observed in interacting galaxies using the invariant manifolds associated to the Lyapunov orbits of the Lagrangian points of the galactic system, when the two galaxies are considered as two point masses in a circular orbit.

  19. Multi-shell effective interactions

    NASA Astrophysics Data System (ADS)

    Tsunoda, Naofumi; Takayanagi, Kazuo; Hjorth-Jensen, Morten; Otsuka, Takaharu

    2014-02-01

    Background: Effective interactions, either derived from microscopic theories or based on fitting selected properties of nuclei in specific mass regions, are widely used inputs to shell-model studies of nuclei. The commonly used unperturbed basis functions are given by the harmonic oscillator. Until recently, most shell-model calculations have been confined to a single oscillator shell like the sd shell or the pf shell. Recent interest in nuclei away from the stability line requires, however, larger shell-model spaces. Because the derivation of microscopic effective interactions has been limited to degenerate models spaces, there are both conceptual and practical limits to present shell-model calculations that utilize such interactions. Purpose: The aim of this work is to present a novel microscopic method to calculate effective nucleon-nucleon interactions for the nuclear shell model. Its main difference from existing theories is that it can be applied not only to degenerate model spaces but also to nondegenerate model spaces. This has important consequences, in particular for intershell matrix elements of effective interactions. Methods: The formalism is presented in the form of a many-body perturbation theory based on the recently developed extended Kuo-Krenciglowa method. Our method enables us to microscopically construct effective interactions not only in one oscillator shell but also for several oscillator shells. Results: We present numerical results using effective interactions within (i) a single oscillator shell (a so-called degenerate model space) like the sd shell or the pf shell and (ii) two major shells (nondegenerate model space) like the sdf7p3 shell or the pfg9 shell. We also present energy levels of several nuclei that have two valence nucleons on top of a given closed-shell core. Conclusions: Our results show that the present method works excellently in shell-model spaces that comprise several oscillator shells, as well as in a single oscillator

  20. Interactive real time flow simulations

    NASA Technical Reports Server (NTRS)

    Sadrehaghighi, I.; Tiwari, S. N.

    1990-01-01

    An interactive real time flow simulation technique is developed for an unsteady channel flow. A finite-volume algorithm in conjunction with a Runge-Kutta time stepping scheme was developed for two-dimensional Euler equations. A global time step was used to accelerate convergence of steady-state calculations. A raster image generation routine was developed for high speed image transmission which allows the user to have direct interaction with the solution development. In addition to theory and results, the hardware and software requirements are discussed.

  1. Exaggerated Claims for Interactive Stories

    NASA Astrophysics Data System (ADS)

    Thue, David; Bulitko, Vadim; Spetch, Marcia; Webb, Michael

    As advertising becomes more crucial to video games' success, developers risk promoting their products beyond the features that they can actually include. For features of interactive storytelling, the effects of making such exaggerations are not well known, as reports from industry have been anecdotal at best. In this paper, we explore the effects of making exaggerated claims for interactive stories, in the context of the theory of advertising. Results from a human user study show that female players find linear and branching stories to be significantly less enjoyable when they are advertised with exaggerated claims.

  2. Macrophage Cryptococcus interactions: an update

    PubMed Central

    Mansour, Michael K.; Reedy, Jennifer L.; Tam, Jenny M.; Vyas, Jatin M.

    2014-01-01

    Cryptococcus species are fungal pathogens that are a leading cause of mortality. Initial inoculation is through the pulmonary route and, if disseminated, results in severe invasive infection including meningoencephalitis. Macrophages are the dominant phagocytic cell that interacts with Cryptococcus. Emerging theories suggest that Cryptococcus microevolution in macrophages is linked to survival and virulence within the host. In addition, Cryptococcus elaborates virulence factors as well as usurps host machinery to establish macrophage activation states that are permissive to intracellular survival and replication. In this review, we provide an update of the recent findings pertaining to macrophage interaction with Cryptococcus and focus on new avenues for biomedical research. PMID:24660045

  3. Dynamics of convective scale interaction

    NASA Technical Reports Server (NTRS)

    Purdom, James F. W.; Sinclair, Peter C.

    1988-01-01

    Several of the mesoscale dynamic and thermodynamic aspects of convective scale interaction are examined. An explanation of how sounding data can be coupled with satellite observed cumulus development in the warm sector and the arc cloud line's time evolution to develop a short range forecast of expected convective intensity along an arc cloud line. The formative, mature and dissipating stages of the arc cloud line life cycle are discussed. Specific properties of convective scale interaction are presented and the relationship between arc cloud lines and tornado producing thunderstorms is considered.

  4. Interaction of caldesmon with phospholipids.

    PubMed Central

    Czuryło, E A; Zborowski, J; Dabrowska, R

    1993-01-01

    The interaction of caldesmon with liposomes composed of various phospholipids has been examined by tryptophan fluorescence spectroscopy. The results indicate that caldesmon makes its strongest complex with phosphatidylserine (PS) vesicles (Kass. = 1.45 x 10(5) M-1). Both electrostatic and hydrophobic interactions contribute to the stability of this complex. The site for strong binding of PS seems to be located in the N-terminal part of the 34 kDa C-terminal fragment of caldesmon. Binding of PS at this site results in displacement of calmodulin from its complex with caldesmon. Images Figure 4 PMID:8484721

  5. Elementary Particles and Weak Interactions

    DOE R&D Accomplishments Database

    Lee, T. D.; Yang, C. N.

    1957-01-01

    Some general patterns of interactions between various elementary particles are reviewed and some general questions concerning the symmetry properties of these particles are studied. Topics are included on the theta-tau puzzle, experimental limits on the validity of parity conservation, some general discussions on the consequences due to possible non-invariance under P, C, and T, various possible experimental tests on invariance under P, C, and T, a two-component theory of the neutrino, a possible law of conservation of leptons and the universal Fermi interactions, and time reversal invariance and Mach's principle. (M.H.R.)

  6. Climate Change and Disturbance Interactions

    NASA Astrophysics Data System (ADS)

    McKenzie, Don; Allen, Craig D.

    2007-05-01

    Workshop on Climate Change and Disturbance Interactions in Western North America, Tucson, Ariz., 12-15 February 2007 Warming temperatures across western North America, coupled with increased drought, are expected to exacerbate disturbance regimes, particularly wildfires, insect outbreaks, and invasions of exotic species. Many ecologists and resource managers expect ecosystems to change more rapidly from disturbance effects than from the effects of a changing climate by itself. A particular challenge is to understand the interactions among disturbance regimes; for example, how will massive outbreaks of bark beetles, which kill drought-stressed trees by feeding on cambial tissues, increase the potential for large severe wildfires in a warming climate?

  7. Electron spin from self interaction

    SciTech Connect

    Spavieri, G. |

    1992-06-01

    The author explores the possibility that the electron self-interaction is the origin of the spin and of the radiative effects of QED. The electron is conceived as a charged, massless, point particle with a quantum or stochastic, internal motion about its center of mass and bound by a self-interaction potential. The hydrodynamic equations of motion describing the electron in its center of mass frame are related to non-Markovian stochastic equations recently used to derive the Schroedinger equation. By averaging over this stochastic internal motion and identifying the energy with the rest mass energy, the angular momentum exhibits properties characteristic of spin. The electromagnetic self-interactions added to the Hamiltonian of the particle correct the g factor to yield the anomalous value (g{minus}2)/2 {approx} 1159.7(2.3) X 10{sup {minus}6} in agreement with experiment. Calculations of other {open_quotes}radiative{close_quotes} effects including the Lamb shift are presented. The results obtained are finite and suggest that the QED corrections attributed to radiative effects could be obtained classically, i.e., without second quantization and renormalization, by complementing the Dirac theory with this self-interaction mechanism. The g factor dependence on the external magnetic field of this and other spin models is compared with that of QED, showing that these theories can be tested by the present precision measurements of the g factor. 33 refs., 2 tabs.

  8. Microcomputer Applications in Interaction Analysis.

    ERIC Educational Resources Information Center

    Wadham, Rex A.

    The Timed Interval Categorical Observation Recorder (TICOR), a portable, battery powered microcomputer designed to automate the collection of sequential and simultaneous behavioral observations and their associated durations, was developed to overcome problems in gathering subtle interaction analysis data characterized by sequential flow of…

  9. Wave/current interaction model

    NASA Technical Reports Server (NTRS)

    Liu, A. K.

    1988-01-01

    The wave-current interaction for the application to remote sensing data via numerical simulations and data comparison is modelled. Using the field data of surface current shear, wind condition and ambient wave spectrum, the numerical simulations of directional wave spectrum evolution were used to interpret and to compare with the aircraft data from Radar Ocean Wave Spectrometer (ROWS) and Surface Contour Radar (SCR) across the front during Frontal Air Sea Interaction Experiment (FASINEX). The wave-ice interaction was inspired by the observation of large amplitude waves hundreds of kms inside the ice pack in the Weddell Sea, resulting in breakup of the ice pack. The developed analysis of processes includes the refraction of waves at the pack edge, the effects of pack compression on wave propagation, wave train stability and buckling stability in the ice pack. Sources of pack compression and interaction between wave momentum and pack compression are investigated. Viscous camping of propagating waves in the marginal ice zone are also studied. The analysis suggests an explanation for the change in wave dispersion observed from the ship and the sequence of processes that cause ice pack breakup, pressure ridge formation and the formation of open bands of water.

  10. Interactive Video Disc Orientation Documentation.

    ERIC Educational Resources Information Center

    Frost, William J.; And Others

    This report provides the documentation for a proposed interactive videodisk to be produced for use in orienting freshman students to the Harvey A. Andruss Library of Bloomsburg University (Pennsylvania). A rationale for the project and a plan of action are followed by a production time line and tentative program outline. An outline of the library…

  11. Inelastic final-state interaction

    SciTech Connect

    Suzuki, Mahiko

    2008-03-01

    The final-state interaction in multichannel decay processes is systematically studied in the hadronic picture with application to B decay in mind. Since the final-state interaction is intrinsically interwoven with the decay interaction in this case, no simple phase theorem like ''Watson's theorem'' holds for experimentally observed final states. We first solve exactly the two-channel problem as a toy model in order to clarify the issues. The constraints of the two-channel approximation turns out to be too stringent for most B decay modes, but realistic multichannel problems are too complex for useful quantitative analysis at present. To alleviate the stringent constraints of the two-body problem and to cope with complexity beyond it, we introduce a method of approximation that is applicable to the case where one prominent inelastic channel dominates over all others. We illustrate this approximation method with the amplitude of the decay B{yields}K{pi} fed by the intermediate states of a charmed-meson pair. Even with our approximation we need more accurate information of strong interactions than we have now. Nonetheless we are able to obtain some insight in the issue and draw useful conclusions on general features on the strong phases.

  12. Inelastic final-state interaction

    NASA Astrophysics Data System (ADS)

    Suzuki, Mahiko

    2008-03-01

    The final-state interaction in multichannel decay processes is systematically studied in the hadronic picture with application to B decay in mind. Since the final-state interaction is intrinsically interwoven with the decay interaction in this case, no simple phase theorem like “Watson’s theorem” holds for experimentally observed final states. We first solve exactly the two-channel problem as a toy model in order to clarify the issues. The constraints of the two-channel approximation turns out to be too stringent for most B decay modes, but realistic multichannel problems are too complex for useful quantitative analysis at present. To alleviate the stringent constraints of the two-body problem and to cope with complexity beyond it, we introduce a method of approximation that is applicable to the case where one prominent inelastic channel dominates over all others. We illustrate this approximation method with the amplitude of the decay B→Kπ fed by the intermediate states of a charmed-meson pair. Even with our approximation we need more accurate information of strong interactions than we have now. Nonetheless we are able to obtain some insight in the issue and draw useful conclusions on general features on the strong phases.

  13. Increasing Positive Interactive Classroom Behavior.

    ERIC Educational Resources Information Center

    Kotcher, Elaine; Doremus, Richard R.

    During the spring of 1972 training workshops for 88 elementary and secondary teachers of the Great Neck Public Schools held to examine four hypotheses: 1) workshops in training teachers to observe classroom behavior would significantly increase these same teachers' positive classroom interactive behaviors consisting of teacher, pupil-pupil,…

  14. Education, Interaction, and Social Change.

    ERIC Educational Resources Information Center

    Hodgkinson, Harold L.

    This book examines the interaction of education and other elements in our culture. The social system of education is seen as similar to that of such other formal social institutions as business. Moreover, an understanding of the role and function of education can be achieved through an application of social science theory and research findings.…

  15. Gendered Language in Interactive Discourse

    ERIC Educational Resources Information Center

    Hussey, Karen A.; Katz, Albert N.; Leith, Scott A.

    2015-01-01

    Over two studies, we examined the nature of gendered language in interactive discourse. In the first study, we analyzed gendered language from a chat corpus to see whether tokens of gendered language proposed in the gender-as-culture hypothesis (Maltz and Borker in "Language and social identity." Cambridge University Press, Cambridge, pp…

  16. Interaction of Nanoparticles with Biofilms

    EPA Science Inventory

    In this work we have studied the interaction and adsorption of engineered nanoparticles such as TiO2, ZnO, CeO2 , and carbon nanotubes with biofilms. Biofilm is an extracellular polymeric substance coating comprised of living material and it is an aggregation of bacteria, algae, ...

  17. Social Interactions in Online Gaming

    ERIC Educational Resources Information Center

    Griffiths, Mark; Hussain, Zaheer; Grüsser, Sabine M.; Thalemann, Ralf; Cole, Helena; Davies, Mark N. O.; Chappell, Darren

    2011-01-01

    This paper briefly overviews five studies examining massively multiplayer online role-playing games (MMORPGs). The first study surveyed 540 gamers and showed that the social aspects of the game were the most important factor for many gamers. The second study explored the social interactions of 912 MMORPG players and showed they created strong…

  18. Interaction quenches of Fermi gases

    SciTech Connect

    Uhrig, Goetz S.

    2009-12-15

    It is shown that the jump in the momentum distribution of Fermi gases evolves smoothly for small and intermediate times once an interaction between the fermions is suddenly switched on. The jump does not vanish abruptly. The loci in momentum space where the jumps occur are those of the noninteracting Fermi sea. No relaxation of the Fermi surface geometry takes place.

  19. Interactive Whiteboards in Japanese Education

    ERIC Educational Resources Information Center

    Liversidge, Gordon

    2013-01-01

    The use of interactive whiteboards (IWBs) is widespread in the United Kingdom, Australia, and to some extent in the United States and Canada. However, this potentially learning enhancing technology has been adopted very little in Japan at any level of education, apart from some international schools. Furthermore, one of the world's two leading IWB…

  20. Nonlinear Optical Interactions in Semiconductors

    DTIC Science & Technology

    1984-03-16

    aU internal audits for TACAN Corporation. 7 V. Coupling A, C. N. R. S., Physique du Solide et Energie Solaire We have an ongoing interaction with Dr...underway at TACAN Corporation. We regularly discuss optical pumping and four - wave parametric mixing in multiple quantum well material and plan to

  1. Interactive publications: creation and usage

    NASA Astrophysics Data System (ADS)

    Thoma, George R.; Ford, Glenn; Chung, Michael; Vasudevan, Kirankumar; Antani, Sameer

    2006-02-01

    As envisioned here, an "interactive publication" has similarities to multimedia documents that have been in existence for a decade or more, but possesses specific differentiating characteristics. In common usage, the latter refers to online entities that, in addition to text, consist of files of images and video clips residing separately in databases, rarely providing immediate context to the document text. While an interactive publication has many media objects as does the "traditional" multimedia document, it is a self-contained document, either as a single file with media files embedded within it, or as a "folder" containing tightly linked media files. The main characteristic that differentiates an interactive publication from a traditional multimedia document is that the reader would be able to reuse the media content for analysis and presentation, and to check the underlying data and possibly derive alternative conclusions leading, for example, to more in-depth peer reviews. We have created prototype publications containing paginated text and several media types encountered in the biomedical literature: 3D animations of anatomic structures; graphs, charts and tabular data; cell development images (video sequences); and clinical images such as CT, MRI and ultrasound in the DICOM format. This paper presents developments to date including: a tool to convert static tables or graphs into interactive entities, authoring procedures followed to create prototypes, and advantages and drawbacks of each of these platforms. It also outlines future work including meeting the challenge of network distribution for these large files.

  2. AIP and its interacting partners.

    PubMed

    Trivellin, Giampaolo; Korbonits, Márta

    2011-08-01

    Germline mutations in the aryl hydrocarbon receptor-interacting protein gene (AIP) predispose to young-onset pituitary tumours, most often to GH- or prolactin-secreting adenomas, and most of these patients belong to familial isolated pituitary adenoma families. The molecular pathway initiated by the loss-of-function AIP mutations leading to pituitary tumour formation is unknown. AIP, a co-chaperone of heat-shock protein 90 and various nuclear receptors, belongs to the family of tetratricopeptide repeat (TPR)-containing proteins. It has three antiparallel α-helix motifs (TPR domains) that mediate the interaction of AIP with most of its partners. In this review, we summarise the known interactions of AIP described so far. The identification of AIP partners and the understanding of how AIP interacts with these proteins might help to explain the specific phenotype of the families with heterozygous AIP mutations, to gain deeper insight into the pathological process of pituitary tumour formation and to identify novel drug targets.

  3. Work Cognitions in Multicultural Interaction.

    ERIC Educational Resources Information Center

    Holt, John; Keats, Daphne M.

    1992-01-01

    Investigates the influence of ethnic cultural background and multicultural interaction for 120 males drawn from Aboriginal, Anglo-Saxon, Chinese, and Lebanese cultural communities in Australia. Responses to the Work Cognitions Questionnaire reveal differences in the structure of achievement goals and work values for the 4 groups of 30 subjects…

  4. Child Characteristics by Model Interactions.

    ERIC Educational Resources Information Center

    Featherstone, Helen J.

    Data from the 1969-70 and 1970-71 Head Start Planned Variation (HSPV)Study were used to examine program-child interactions. An effort was made to determine whether different preschool programs have different cognitive effects on different types of children. Seven hypotheses for the analysis of the data were generated from the results of the HSPV…

  5. TROPIX plasma interactions group report

    NASA Technical Reports Server (NTRS)

    Herr, Joel L.; Chock, Ricaurte

    1993-01-01

    The purpose is to summarize the spacecraft charging analysis conducted by the plasma interactions group during the period from April 1993 to July 1993, on the proposed TROPIX spacecraft, and to make design recommendations which will limit the detrimental effects introduced by spacecraft charging. The recommendations were presented to the TROPIX study team at a Technical Review meeting held on 15 July 1993.

  6. Modeling Interactions in Small Groups

    ERIC Educational Resources Information Center

    Heise, David R.

    2013-01-01

    A new theory of interaction within small groups posits that group members initiate actions when tension mounts between the affective meanings of their situational identities and impressions produced by recent events. Actors choose partners and behaviors so as to reduce the tensions. A computer model based on this theory, incorporating reciprocal…

  7. Interaction of Radiation with Matter

    SciTech Connect

    Rickards, J.

    2010-09-10

    A flash introductory course in the interaction of ionizing radiation with matter is presented for students starting out in nuclear physics, medical applications of radiation, materials modification, radiation damage, detectors, materials analysis, radiation protection, and other applications. Emphasis is on defining basic concepts and on a simple visualization of ideas for practical applications, rather than on completeness or rigor.

  8. Activities for an Interactive Classroom.

    ERIC Educational Resources Information Center

    Golub, Jeffrey N.

    Focusing particularly on student writing, this book describes the principles of an interactive classroom and presents specific activities which adhere to those principles. Acknowledging that such classrooms require that the students feel comfortable with each other, the book details several activities that help to build a positive classroom…

  9. Nonverbal Behavior in Tutoring Interactions.

    ERIC Educational Resources Information Center

    Feldman, Robert S.

    This document reports on a series of studies carried out concerning nonverbal behavior in peer tutoring interactions. The first study examined the encoding (enactment) of nonverbal behavior in a tutoring situation. Results clearly indicated that the tutor's nonverbal behavior was affected by the performance of the tutee. The question of whether or…

  10. Affect Control in International Interactions

    ERIC Educational Resources Information Center

    Heise, David R.; Lerner, Steven J.

    2006-01-01

    This research tests the proposition that national leaders generate international interactions in the process of maintaining sentiments about nations and international actions. The analysis deals with 1,934 international incidents in which one of 25 Middle Eastern nations responded twice within four weeks to an instigation by another of the 25…

  11. Interactive Multimedia: Practice and Promise.

    ERIC Educational Resources Information Center

    Latchem, Colin, Ed.; And Others

    This book describes developments in interactive multimedia (IMM) in the early 1990s. Its aim is to provide educators, students, trainers, librarians, managers, and practitioners with an overview, not only of the directions and uses of the technology, but also of the research foundations and educational and contextual issues that need to be…

  12. Demonstration of Data Interactive Publications

    NASA Astrophysics Data System (ADS)

    Domenico, B.; Weber, J.

    2012-04-01

    This is a demonstration version of the talk given in session ESSI2.4 "Full lifecycle of data." For some years now, the authors have developed examples of online documents that allowed the reader to interact directly with datasets, but there were limitations that restricted the interaction to specific desktop analysis and display tools that were not generally available to all readers of the documents. Recent advances in web service technology and related standards are making it possible to develop systems for publishing online documents that enable readers to access, analyze, and display the data discussed in the publication from the perspective and in the manner from which the author wants it to be represented. By clicking on embedded links, the reader accesses not only the usual textual information in a publication, but also data residing on a local or remote web server as well as a set of processing tools for analyzing and displaying the data. With the option of having the analysis and display processing provided on the server (or in the cloud), there are now a broader set of possibilities on the client side where the reader can interact with the data via a thin web client, a rich desktop application, or a mobile platform "app." The presentation will outline the architecture of data interactive publications along with illustrative examples.

  13. Students and the Interactive Whiteboard

    ERIC Educational Resources Information Center

    Biró, Piroska

    2011-01-01

    The spread of Interactive Whiteboards in Hungary has made students more curious, interested and motivated. The new digital generation claims reform and besides the traditional education they need digital material, extra knowledge since it is much easier to access extra information in connection with a particular curriculum. They spend a lot of…

  14. JSC interactive basic accounting system

    NASA Technical Reports Server (NTRS)

    Spitzer, J. F.

    1978-01-01

    Design concepts for an interactive basic accounting system (IBAS) are considered in terms of selecting the design option which provides the best response at the lowest cost. Modeling the IBAS workload and applying this workload to a U1108 EXEC 8 based system using both a simulation model and the real system is discussed.

  15. Learning with Interactive Graphical Representations.

    ERIC Educational Resources Information Center

    Saljo, Roger, Ed.

    1999-01-01

    The seven articles of this theme issue deal with the use of computer-based interactive graphical representations. Studying their use will bring answers to users of static graphics in traditional paper-based media and those who plan instruction using graphical representations that allow semantically direct manipulation. (SLD)

  16. Inelastic final-state interaction

    SciTech Connect

    Suzuki, Mahiko; Suzuki, Mahiko

    2007-10-29

    The final-state interaction in multichannel decay processes is systematically studied with application to B decay in mind. Since the final-state interaction is intrinsically interwoven with the decay interaction in this case, no simple phase theorem like"Watson's theorem" holds for experimentally observed final states. We first examine in detail the two-channel problem as a toy-model to clarify the issues and to remedy common mistakes made in earlier literature. Realistic multichannel problems are too challenging for quantitative analysis. To cope with mathematical complexity, we introduce a method of approximation that is applicable to the case where one prominent inelastic channel dominates over all others. We illustrate this approximation method in the amplitude of the decay B to pi K fed by the intermediate states of a charmed meson pair. Even with our approximation we need more accurate information of strong interactions than we have now. Nonetheless we are able to obtain some insight in the issue and draw useful conclusions on general features on the strong phases.

  17. Seven Statements on Interactive Video.

    ERIC Educational Resources Information Center

    Gastkemper, F.

    This paper is concerned with the educational significance of interactive video. To clarify this, seven basic educational concepts are reviewed: (1) education and training are organized forms of learning; (2) goals and objectives can be grouped into the cognitive, affective, and psychomotor domains of learning; (3) education refers to learning…

  18. Literary Gaps Invite Creative Interaction.

    ERIC Educational Resources Information Center

    Watson, Jerry J.

    Literary gaps were identified by Wolfgang Iser in 1974 as "vacant pages" that invite the reader to reflect and enter into the text thereby motivating students to experience the text as reality. Arthur Applebee, in 1979, identified three categories to distinguish children's types of interaction with stories: (1) the complexity of literary…

  19. [Drug interactions and the elderly].

    PubMed

    Le Jeunne, C; Hugues, F C

    1995-01-01

    Elderly people are particularly at risk for drug interactions, for several reasons. They are the part of the population who consume the most drugs: over 75 years the mean number of drugs on a prescription is 5.6. As they suffer from various associated diseases, they see several medical specialists, each of them adding a new prescription to the others. Self-prescriptions complicate the problem because they are rarely mentioned. Changes in pharmacokinetics in the elderly tend to increase blood concentrations of drugs. Elderly people suffer from altered homeostatic mechanisms to compensate for adverse drug effects. As a whole, such individuals are more exposed to the side effects of drugs. The drugs most often involved in these interactions are diuretics, non-steroidal anti-inflammatory drugs, benzodiazepines, antiarrhythmics, cardiac glycosides, antihypertensive drugs, oral antidiabetics and antalgics. The clinical accidents most often occurring with these drug interactions are: malaise, orthostatic hypotension, loss of conciousness, amnesia, confusion, renal insufficiency, digestive problems. Since elderly people are less likely to recover easily, this problem of drug interaction should be looked for systematically.

  20. Early Mother-Child Interaction.

    ERIC Educational Resources Information Center

    d'Agostino, Micheline

    1986-01-01

    This journal issue presents an overview of mother-child interaction during the first year of the child's life. Contents of the first section, which concern the development of the mother-child relationship, focus on the concept of the maternal instinct, mother and child during intrauterine life, birth of the child, the postnatal period (including…

  1. Grid Interaction Technical Team Roadmap

    SciTech Connect

    2013-06-01

    The mission of the Grid Interaction Technical Team (GITT) is to support a transition scenario to large scale grid-connected vehicle charging with transformational technology, proof of concept and information dissemination. The GITT facilitates technical coordination and collaboration between vehicle-grid connectivity and communication activities among U.S. DRIVE government and industry partners.

  2. Predicting Deviancy in Family Interaction.

    ERIC Educational Resources Information Center

    Karpowitz, Dennis H.

    Should a stimulus be defined as the single event immediately preceding a response (simple stimulus) or as a constellation of antecedents representing several preceding events (complex stimulus)? Sixty-eight families with a child between four and eight years of age were observed, and family interactions coded in the naturalistic setting of the…

  3. Interactive Cable Television. Final Report.

    ERIC Educational Resources Information Center

    Active Learning Systems, Inc., Minneapolis, MN.

    This report describes an interactive video system developed by Active Learning Systems which utilizes a cable television (TV) network as its delivery system to transmit computer literacy lessons to high school and college students. The system consists of an IBM PC, Pioneer LDV 4000 videodisc player, and Whitney Supercircuit set up at the head end…

  4. Interactive Television and Distance Learning.

    ERIC Educational Resources Information Center

    Rees, Fred J.; Downs, Dennis A.

    1995-01-01

    Describes the origins and operations of the Iowa Communications Network, an interactive distance learning program. Presents several examples of how the network can benefit music educators in college and K-12 institutions. Maintains that the system can be a model for similar distance music education networks. (CFR)

  5. Suicidal Behavior and Marital Interaction.

    ERIC Educational Resources Information Center

    Berman, Alan L.; And Others

    1992-01-01

    Presents two cases chosen to draw attention to marital and developmental dynamics of suicidal behavior. Both case vignettes are based on individual interviews with suicidal persons and their spouses during the suicidal person's psychiatric hospitalization, and both include observations of the marital interaction. Case vignettes are followed by…

  6. Classroom Interaction and Language Output

    ERIC Educational Resources Information Center

    Wang, Qiaoying; Castro, Carolyn D.

    2010-01-01

    This study investigates the effects of classroom interactions between a) students and students and b) students and teachers on the learning of English passivization by L1 Chinese adult learners of English as a foreign language during the language input and output treatments. In phase 1, both groups were asked to read and underline the input…

  7. Interaction in Distance Nursing Education

    ERIC Educational Resources Information Center

    Boz Yuksekdag, Belgin

    2012-01-01

    The purpose of this study is to determine psychiatry nurses' attitudes toward the interactions in distance nursing education, and also scrunize their attitudes based on demographics and computer/Internet usage. The comparative relational scanning model is the method of this study. The research data were collected through "The Scale of Attitudes of…

  8. Effective interactions between fluid membranes

    NASA Astrophysics Data System (ADS)

    Lu, Bing-Sui; Podgornik, Rudolf

    2015-08-01

    A self-consistent theory is proposed for the general problem of interacting undulating fluid membranes subject to the constraint that they do not interpenetrate. We implement the steric constraint via an exact functional integral representation and, through the use of a saddle-point approximation, transform it into a novel effective steric potential. The steric potential is found to consist of two contributions: one generated by zero-mode fluctuations of the membranes and the other by thermal bending fluctuations. For membranes of cross-sectional area S , we find that the bending fluctuation part scales with the intermembrane separation d as d-2 for d ≪√{S } but crosses over to d-4 scaling for d ≫√{S } , whereas the zero-mode part of the steric potential always scales as d-2. For membranes interacting exclusively via the steric potential, we obtain closed-form expressions for the effective interaction potential and for the rms undulation amplitude σ , which becomes small at low temperatures T and/or large bending stiffnesses κ . Moreover, σ scales as d for d ≪√{S } but saturates at √{kBT S /κ } for d ≫√{S } . In addition, using variational Gaussian theory, we apply our self-consistent treatment to study intermembrane interactions subject to different types of potentials: (i) the Moreira-Netz potential for a pair of strongly charged membranes with an intervening solution of multivalent counterions, (ii) an attractive square well, (iii) the Morse potential, and (iv) a combination of hydration and van der Waals interactions.

  9. Molecular interactions between desmosomal cadherins.

    PubMed Central

    Syed, Shabih-e-Hassnain; Trinnaman, Brian; Martin, Stephen; Major, Sarah; Hutchinson, Jon; Magee, Anthony I

    2002-01-01

    Desmocollins (Dscs) and desmogleins (Dsgs) are cell-adhesion molecules involved in the formation of desmosome cell-cell junctions and share structural similarities to classical cadherins such as E-cadherin. In order to identify and provide quantitative information on the types of protein-protein interactions displayed by the type 2 isoforms and investigate the role of Ca(2+) in this process, we have developed an Escherichia coli expression system to generate recombinant proteins containing the first two extracellular domains, namely Dsg2(1-2) and Dsc2(1-2). Analytical ultracentrifugation, chemical cross-linking, CD, fluorescence and BIAcore have been used to provide the first direct evidence of Ca(2+) binding to desmosomal cadherins. These studies suggest that Dsc2(1-2) not only exhibits homophilic interactions in solution, but can also form heterophilic interactions with Dsg2(1-2). The latter, on the other hand, shows much weaker homophilic association. Our results further demonstrate that heterophilic interactions are Ca(2+)-dependent, whereas the Ca(2+)-dependence of homophilic association is less clear. Our data indicate that the functional properties of Dsc2(1-2) are more similar to those of classical cadherins, consistent with the observation that Dsc shares a higher level of sequence homology with classical cadherins than does Dsg. In addition to corroborating the conclusions of previously reported transfection studies which suggest the formation of lateral heterodimers and homodimers, our results also provide direct quantitative information on the strength of these interactions which are essential for understanding the adhesion mechanism. PMID:11853539

  10. Spectra, composition, and interactions of nuclei with magnet interaction chambers

    NASA Technical Reports Server (NTRS)

    Parneil, T. A.; Derrickson, J. H.; Fountain, W. F.; Roberts, F. E.; Tabuki, T.; Watts, J. W.; Burnett, T. H.; Cherry, M. C.; Dake, S.; Fuki, M.

    1990-01-01

    Emulsion chambers will be flown in the Astromag Facility to measure the cosmic ray composition and spectra to 10 exp 15 eV total energy and to definitively study the characteristics of nucleus-nucleus interactions above 10 exp 12 eV/n. Two configurations of emulsion chambers will be flown in the SCIN/MAGIC experiment. One chamber has an emulsion target and a calorimeter similar to those recently flown on balloons for composition and spectra measurements. The other has an identical calorimeter and a low-density target section optimized for performing rigidity measurements on charged particles produced in interactions. The transverse momenta of charged and neutral mesons, direct hadronic pairs from resonance decays and interference effects, and possible charge clustering in high-density states of matter will be studied.

  11. The Interaction Hypothesis: A Critical Evaluation.

    ERIC Educational Resources Information Center

    Ellis, Rod

    The oral interaction hypothesis, proposed by Long and investigated by Pica, in second language (L2) acquisition is critiqued. The interaction hypothesis advances two major claims about the role of interaction in L2 acquisition: (1) comprehensible input is necessary for L2 acquisition; and (2) modifications to the interactional structure of…

  12. Perturbation analyses of intermolecular interactions

    NASA Astrophysics Data System (ADS)

    Koyama, Yohei M.; Kobayashi, Tetsuya J.; Ueda, Hiroki R.

    2011-08-01

    Conformational fluctuations of a protein molecule are important to its function, and it is known that environmental molecules, such as water molecules, ions, and ligand molecules, significantly affect the function by changing the conformational fluctuations. However, it is difficult to systematically understand the role of environmental molecules because intermolecular interactions related to the conformational fluctuations are complicated. To identify important intermolecular interactions with regard to the conformational fluctuations, we develop herein (i) distance-independent and (ii) distance-dependent perturbation analyses of the intermolecular interactions. We show that these perturbation analyses can be realized by performing (i) a principal component analysis using conditional expectations of truncated and shifted intermolecular potential energy terms and (ii) a functional principal component analysis using products of intermolecular forces and conditional cumulative densities. We refer to these analyses as intermolecular perturbation analysis (IPA) and distance-dependent intermolecular perturbation analysis (DIPA), respectively. For comparison of the IPA and the DIPA, we apply them to the alanine dipeptide isomerization in explicit water. Although the first IPA principal components discriminate two states (the α state and PPII (polyproline II) + β states) for larger cutoff length, the separation between the PPII state and the β state is unclear in the second IPA principal components. On the other hand, in the large cutoff value, DIPA eigenvalues converge faster than that for IPA and the top two DIPA principal components clearly identify the three states. By using the DIPA biplot, the contributions of the dipeptide-water interactions to each state are analyzed systematically. Since the DIPA improves the state identification and the convergence rate with retaining distance information, we conclude that the DIPA is a more practical method compared with the

  13. IRAS study of interacting galaxies

    NASA Astrophysics Data System (ADS)

    Allam, S.

    1998-04-01

    Interacting galaxies are ideal laboratories for studying the influence of gravitational forces on galaxies. From theoretical and observational studies, we know how sensitive galaxies are to tidal interaction, from the formation of tidal tails, bridges, bursts of star formation up to a complete merging of the galaxies. The Far Infrared (FIR) properties of interacting galaxies give information on the dynamical and physical properties of these systems. Several earlier studies using the IRAS point source catalogue (IPSC) and IRAS Faint Source Survey (FSS), showed that the FIR emission from interacting/merging galaxies is enhanced with respect to isolated non-interacting galaxies; moreover, that high density environments have more influence in producing enhanced FIR emission over isolated interacting systems. In general the ratio of FIR to optical luminosity in interacting systems was found to be enhanced. It is regarded as an increased star formation (SF) rate in these systems. Later on, due to the rather high IPSC detection threshold, and its low resolution, several contradictory results have been reported. In this thesis the FIR emission from interacting galaxies is studied by using the high resolution IRAS software introduced by Bontekoe et al. (1994). This soft ware package uses a Maximum Entropy method (hereafter MaxEnt). The MaxEnt formulation is rooted in Bayesian probability theory. The raw IRAS data contains the Point Spread Function (PSF) of both the telescope mirror (60 cm --> 1 arcmin at 60 μm) and the PSF of the detectors (≃ 5 arcmin). Since there is much redundancy in the data, the MaxEnt routine can be used to remove the 5 arcmin PSF from the detectors. For many interacting galaxies this is enough to resolve them. The size of the images was chosen such that the objects could be studied including their surroundings. The absolute position calibration and flux estimates for the MaxEnt images are described in Allam et al. (1996). Because of the high

  14. Interactions between uniformly magnetized spheres

    NASA Astrophysics Data System (ADS)

    Edwards, Boyd F.; Riffe, D. M.; Ji, Jeong-Young; Booth, William A.

    2017-02-01

    We use simple symmetry arguments suitable for undergraduate students to demonstrate that the magnetic energy, forces, and torques between two uniformly magnetized spheres are identical to those between two point magnetic dipoles. These arguments exploit the equivalence of the field outside of a uniformly magnetized sphere with that of a point magnetic dipole, and pertain to spheres of arbitrary sizes, positions, and magnetizations. The point dipole/sphere equivalence for magnetic interactions may be useful in teaching and research, where dipolar approximations for uniformly magnetized spheres can now be considered to be exact. The work was originally motivated by interest in the interactions between collections of small neodymium magnetic spheres used as desk toys.

  15. Astronomy education through interactive materials

    NASA Astrophysics Data System (ADS)

    Voelzke, Marcos Rincon; Antunes de Macêdo, Josué

    2015-08-01

    This study presents results of a survey conducted at the Federal Institution of Education, Science and Technology in the North of Minas Gerais (IFNMG), and aimed to investigate the potentialities of the use of interactive materials in the teaching of astronomy. An advanced training course with involved learning activities about basic concepts of astronomy was offered to thirty-two Licenciate students in Physics, Mathematics and Biological Sciences, using the mixed methodology, combined with the three pedagogical moments. Among other aspects, the viability of the use of resources was noticed, involving digital technologies and interactive materials on teaching of astronomy, which may contribute to the broadening of methodological options for future teachers and meet their training needs.

  16. Water-power lifeline interaction

    SciTech Connect

    Lau, B.; Eidinger, J.M.

    1995-12-31

    The interaction of water and power lifelines is described in three modes of operation: normal, fire and earthquake. Case study applications will be taken from large water and electric lifelines serving the greater San Francisco Bay Area operated by East Bay Municipal Utility District (water) and Pacific Gas and Electric (electricity). Two emergency events are examined: the recent 1991 Oakland Hills firestorm and a future Hayward Magnitude 7 earthquake. Both the water and electric lifelines have limitations under these emergencies that will hamper provision of lifeline services to end users of water and electricity. A model is presented to deal with the interactions between these utilities. By using this model, the water utility can plan for a reasonable number of backup power/pumping units to deal with these types of emergency events.

  17. Multiplicities in high energy interactions

    SciTech Connect

    Derrick, M.

    1985-05-13

    This paper reviews the data on multiplicities in high energy interactions. Results from e/sup +/e/sup -/ annihilation, from neutrino interactions, and from hadronic collisions, both diffractive and nondiffractive, are compared and contrasted. The energy dependence of the mean charged multiplicity, , as well as the rapidity density at Y = 0 are presented. For hadronic collisions, the data on neutral pion production shows a strong correlation with . The heavy particle fractions increase with ..sqrt..s up to the highest energies. The charged particle multiplicity distributions for each type of reaction show a scaling behavior when expressed in terms of the mean. Attempts to understand this behavior, which was first predicted by Koba, Nielsen, and Olesen, are discussed. The multiplicity correlations and the energy variation of the shape of the KNO scaling distribution provide important constraints on models. Some extrapolations to the energies of the Superconducting Super Collider are made. 51 refs., 27 figs.

  18. Arabidopsis thaliana—Aphid Interaction

    PubMed Central

    Louis, Joe; Singh, Vijay; Shah, Jyoti

    2012-01-01

    Aphids are important pests of plants that use their stylets to tap into the sieve elements to consume phloem sap. Besides the removal of photosynthates, aphid infestation also alters source-sink patterns. Most aphids also vector viral diseases. In this chapter, we will summarize on recent significant findings in plant-aphid interaction, and how studies involving Arabidopsis thaliana and Myzus persicae (Sülzer), more commonly known as the green peach aphid (GPA), are beginning to provide important insights into the molecular basis of plant defense and susceptibility to aphids. The recent demonstration that expression of dsRNA in Arabidopsis can be used to silence expression of genes in GPA has further expanded the utility of Arabidopsis for evaluating the contribution of the aphid genome-encoded proteins to this interaction. PMID:22666177

  19. Extraterrestrial Studies Using Nuclear Interactions

    NASA Technical Reports Server (NTRS)

    Reedy, Robert C.

    2003-01-01

    Cosmogenic nuclides were used to study the recent histories of the aubrite Norton County and the pallasite Brenham using calculated production rates. Calculations were done of the rates for making cosmogenic noble-gas isotopes in the Jovian satellite Europa by the interactions of galactic cosmic rays and especially trapped Jovian protons. Cross sections for the production of cosmogenic nuclides were reported and plans made to measure additional cross sections. A new code, MCNPX, was used to numerically simulate the interactions of cosmic rays with matter and the subsequent production of cosmogenic nuclides. A review was written about studies of extraterrestrial matter using cosmogenic radionuclides. Several other projects were done. Results are reviewed here with references to my recent publications for details.

  20. Solar Interactions on Spiral Petroglyphs

    NASA Astrophysics Data System (ADS)

    Davis, Brian F.; Preston, Robert A.

    2003-11-01

    Like most prehistoric cultures, the ancestors of the native Puebloan people of the Southwest were aware of the yearly cycle of the sun. This and other natural phenomena are fundamental for interpreting their world view, religion, and art. Some researchers have argued that rock art, particularly petroglyphs, displays this focus on the natural world through the distinctive interplay of sunlight on these carvings. However, the question of whether or not these interactions occur by intention or chance has hampered the acceptance of this evidence by the archaeological community. To address this question we have performed a detailed study of a complete sample of over 100 spiral petroglyphs within a limited area (less than 20 km^2) of central New Mexico. We have examined this sample on both solstices and equinoxes, and have observed well-defined and consistent sunlight interactions on about 80This work clearly demonstrates the reality and profusion of this ancient cultural tradition. Several examples will be presented.

  1. The Interaction-Activity Connection

    NASA Technical Reports Server (NTRS)

    Borne, Kirk D.

    1996-01-01

    A review is presented of the numerous studies that have been undertaken to investigate the likely interaction-activity connection among galaxies. Both observational evidence and theoretical supporting models are reviewed. Some specific examples of "interactive" galaxies from the author's own research are presented: (a) the collision-induced AGN (Active Galactic Nuclei) activity in the radio jet source 3C278; and (b) the collision-induced starburst activity in the spectacular "Cartwheel" ring galaxy. Some comments are offered concerning some of the more promising theoretical investigations that are now taking place. A few words of warning are also offered about the possible misinterpretation of putative collision-induced morphologies among some galaxy samples.

  2. Interactive displays in medical art

    NASA Technical Reports Server (NTRS)

    Mcconathy, Deirdre Alla; Doyle, Michael

    1989-01-01

    Medical illustration is a field of visual communication with a long history. Traditional medical illustrations are static, 2-D, printed images; highly realistic depictions of the gross morphology of anatomical structures. Today medicine requires the visualization of structures and processes that have never before been seen. Complex 3-D spatial relationships require interpretation from 2-D diagnostic imagery. Pictures that move in real time have become clinical and research tools for physicians. Medical illustrators are involved with the development of interactive visual displays for three different, but not discrete, functions: as educational materials, as clinical and research tools, and as data bases of standard imagery used to produce visuals. The production of interactive displays in the medical arts is examined.

  3. Stochastic hyperfine interactions modeling library

    NASA Astrophysics Data System (ADS)

    Zacate, Matthew O.; Evenson, William E.

    2011-04-01

    The stochastic hyperfine interactions modeling library (SHIML) provides a set of routines to assist in the development and application of stochastic models of hyperfine interactions. The library provides routines written in the C programming language that (1) read a text description of a model for fluctuating hyperfine fields, (2) set up the Blume matrix, upon which the evolution operator of the system depends, and (3) find the eigenvalues and eigenvectors of the Blume matrix so that theoretical spectra of experimental techniques that measure hyperfine interactions can be calculated. The optimized vector and matrix operations of the BLAS and LAPACK libraries are utilized; however, there was a need to develop supplementary code to find an orthonormal set of (left and right) eigenvectors of complex, non-Hermitian matrices. In addition, example code is provided to illustrate the use of SHIML to generate perturbed angular correlation spectra for the special case of polycrystalline samples when anisotropy terms of higher order than A can be neglected. Program summaryProgram title: SHIML Catalogue identifier: AEIF_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIF_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU GPL 3 No. of lines in distributed program, including test data, etc.: 8224 No. of bytes in distributed program, including test data, etc.: 312 348 Distribution format: tar.gz Programming language: C Computer: Any Operating system: LINUX, OS X RAM: Varies Classification: 7.4 External routines: TAPP [1], BLAS [2], a C-interface to BLAS [3], and LAPACK [4] Nature of problem: In condensed matter systems, hyperfine methods such as nuclear magnetic resonance (NMR), Mössbauer effect (ME), muon spin rotation (μSR), and perturbed angular correlation spectroscopy (PAC) measure electronic and magnetic structure within Angstroms of nuclear probes through the hyperfine interaction. When

  4. An interactive region merging method

    NASA Astrophysics Data System (ADS)

    Wu, Rongteng

    2011-11-01

    The paper presents a novel region merging method based on the interactive information from users. An image firstly is partitioned into homogeneous regions by using an initial segmentation and the regions will be label by taking an interactive scheme. In this scheme, the users only roughly specify the position and main features of the object and background, then any region will belong to non-label region or label region i.e. object or background. A similarity rule is used to guide the merging process with the help of the users' markers. And then the object of interest is extracted from the image. Experiment results show that the proposed method is efficient for us to extract the object of interest from the complex background.

  5. Interactive Learning During Solar Maximum

    NASA Technical Reports Server (NTRS)

    Ashour-Abdalla, Maha; Curtis, Steven (Technical Monitor)

    2001-01-01

    The goal of this project is to develop and distribute e-educational material for space science during times of solar activity that emphasizes underlying basic science principles of solar disturbances and their effects on Earth. This includes materials such as simulations, animations, group projects and other on-line materials to be used by students either in high school or at the introductory college level. The on-line delivery tool originally intended to be used is known as Interactive Multimedia Education at a Distance (IMED), which is a web-based software system used at UCLA for interactive distance learning. IMED is a password controlled system that allows students to access text, images, bulletin boards, chat rooms, animation, simulations and individual student web sites to study science and to collaborate on group projects.

  6. Bragg interactions in periodic media

    NASA Technical Reports Server (NTRS)

    Jaggard, D. L.

    1976-01-01

    The interaction of electromagnetic waves of wavelength lambda with periodic structures of spatial period lambda are studied. The emphasis of the work is on Bragg interactions where lambda approximately equal to 2 lambda/N and the Bragg order N takes on the values 1, 2,.... An extended coupled waves (ECW) theory is developed for the case N greater or equal to 2 and the results of the theory are found to compare favorably with the exact results of Floquet theory. Numerous numerical results are displayed as Brillouin diagrams for the first few Bragg orders. Moreover, explicit expressions for coupling coefficients, bandgap shifts and bandgap widths are derived for singly periodic media. Particular note is taken of phase speeding effects.

  7. Golgi: Interactive Online Brain Mapping

    PubMed Central

    Brown, Ramsay A.; Swanson, Larry W.

    2015-01-01

    Golgi (http://www.usegolgi.com) is a prototype interactive brain map of the rat brain that helps researchers intuitively interact with neuroanatomy, connectomics, and cellular and chemical architecture. The flood of “-omic” data urges new ways to help researchers connect discrete findings to the larger context of the nervous system. Here we explore Golgi’s underlying reasoning and techniques and how our design decisions balance the constraints of building both a scientifically useful and usable tool. We demonstrate how Golgi can enhance connectomic literature searches with a case study investigating a thalamocortical circuit involving the Nucleus Accumbens and we explore Golgi’s potential and future directions for growth in systems neuroscience and connectomics. PMID:26635596

  8. Interaction theory of mammalian mitochondria.

    PubMed

    Nakada, K; Inoue, K; Hayashi, J

    2001-11-09

    We generated mice with deletion mutant mtDNA by its introduction from somatic cells into mouse zygotes. Expressions of disease phenotypes are limited to tissues expressing mitochondrial dysfunction. Considering that all these mice share the same nuclear background, these observations suggest that accumulation of the mutant mtDNA and resultant expressions of mitochondrial dysfunction are responsible for expression of disease phenotypes. On the other hand, mitochondrial dysfunction and expression of clinical abnormalities were not observed until the mutant mtDNA accumulated predominantly. This protection is due to the presence of extensive and continuous interaction between exogenous mitochondria from cybrids and recipient mitochondria from embryos. Thus, we would like to propose a new hypothesis on mitochondrial biogenesis, interaction theory of mitochondria: mammalian mitochondria exchange genetic contents, and thus lost the individuality and function as a single dynamic cellular unit.

  9. Unified theory of effective interaction

    NASA Astrophysics Data System (ADS)

    Takayanagi, Kazuo

    2016-09-01

    We present a unified description of effective interaction theories in both algebraic and graphic representations. In our previous work, we have presented the Rayleigh-Schrödinger and Bloch perturbation theories in a unified fashion by introducing the main frame expansion of the effective interaction. In this work, we start also from the main frame expansion, and present various nonperturbative theories in a coherent manner, which include generalizations of the Brandow, Brillouin-Wigner, and Bloch-Horowitz theories on the formal side, and the extended Krenciglowa-Kuo and the extended Lee-Suzuki methods on the practical side. We thus establish a coherent and comprehensive description of both perturbative and nonperturbative theories on the basis of the main frame expansion.

  10. Image reproduction with interactive graphics

    NASA Technical Reports Server (NTRS)

    Buckner, J. D.; Council, H. W.; Edwards, T. R.

    1974-01-01

    Software application or development in optical image digital data processing requires a fast, good quality, yet inexpensive hard copy of processed images. To achieve this, a Cambo camera with an f 2.8/150-mm Xenotar lens in a Copal shutter having a Graflok back for 4 x 5 Polaroid type 57 pack-film has been interfaced to an existing Adage, AGT-30/Electro-Mechanical Research, EMR 6050 graphic computer system. Time-lapse photography in conjunction with a log to linear voltage transformation has resulted in an interactive system capable of producing a hard copy in 54 sec. The interactive aspect of the system lies in a Tektronix 4002 graphic computer terminal and its associated hard copy unit.

  11. Research in interactive scene analysis

    NASA Technical Reports Server (NTRS)

    Tenenbaum, J. M.; Garvey, T. D.; Weyl, S. A.; Wolf, H. C.

    1975-01-01

    An interactive scene interpretation system (ISIS) was developed as a tool for constructing and experimenting with man-machine and automatic scene analysis methods tailored for particular image domains. A recently developed region analysis subsystem based on the paradigm of Brice and Fennema is described. Using this subsystem a series of experiments was conducted to determine good criteria for initially partitioning a scene into atomic regions and for merging these regions into a final partition of the scene along object boundaries. Semantic (problem-dependent) knowledge is essential for complete, correct partitions of complex real-world scenes. An interactive approach to semantic scene segmentation was developed and demonstrated on both landscape and indoor scenes. This approach provides a reasonable methodology for segmenting scenes that cannot be processed completely automatically, and is a promising basis for a future automatic system. A program is described that can automatically generate strategies for finding specific objects in a scene based on manually designated pictorial examples.

  12. OVERFLOW-Interaction with Industry

    NASA Technical Reports Server (NTRS)

    Buning, Pieter G.; George, Michael W. (Technical Monitor)

    1996-01-01

    A Navier-Stokes flow solver, OVERFLOW, has been developed by researchers at NASA Ames Research Center to use overset (Chimera) grids to simulate the flow about complex aerodynamic shapes. Primary customers of the OVERFLOW flow solver and related software include McDonnell Douglas and Boeing, as well as the NASA Focused Programs for Advanced Subsonic Technology (AST) and High Speed Research (HSR). Code development has focused on customer issues, including improving code performance, ability to run on workstation clusters and the NAS SP2, and direct interaction with industry on accuracy assessment and validation. Significant interaction with NAS has produced a capability tailored to the Ames computing environment, and code contributions have come from a wide range of sources, both within and outside Ames.

  13. Pellet interaction with runaway electrons

    SciTech Connect

    James, A. N.; Hollmann, E. M.; Yu, J.H.; Austin, M. E.; Commaux, Nicolas JC; Evans, T.E.; Humphrey, D. A.; Jernigan, T. C.; Parks, P. B.; Putvinski, S.; Strait, E. J.; Tynan, G. R.; Wesley, J. C.

    2011-01-01

    We describe results from recent experiments studying interaction of solid polystyrene pellets with a runaway electron current channel generated after cryogenic argon pellet rapid shutdown of DIII-D. Fast camera imaging shows the pellet trajectory and continuum emission from the subsequent explosion, with geometric calibration providing detailed explosion analysis and runaway energy. Electron cyclotron emission also occurs, associated with knock-on electrons broken free from the pellet by RE which then accelerate and runaway, and also with a short lived hot plasma blown off the pellet surface. In addition, we compare heating and explosion times from observations and a model of pellet heating and breakdown by runaway interaction. (C) 2011 Elsevier B.V. All rights reserved

  14. Improved productivity through interactive communication

    NASA Technical Reports Server (NTRS)

    Marino, P. P.

    1985-01-01

    New methods and approaches are being tried and evaluated with the goal of increasing productivity and quality. The underlying concept in all of these approaches, methods or processes is that people require interactive communication to maximize the organization's strengths and minimize impediments to productivity improvement. This paper examines Bendix Field Engineering Corporation's organizational structure and experiences with employee involvement programs. The paper focuses on methods Bendix developed and implemented to open lines of communication throughout the organization. The Bendix approach to productivity and quality enhancement shows that interactive communication is critical to the successful implementation of any productivity improvement program. The paper concludes with an examination of the Bendix methodologies which can be adopted by any corporation in any industry.

  15. The interactive surrogate travel system.

    PubMed

    Nakajima, I; Ichimura, A; Juzoji, H; Mugita, K

    1999-01-01

    The Interactive Surrogate Travel (IST) system is based on the super-miniaturized system of virtual technology, Cave Automatic Virtual Environment (CAVE). Using bilateral virtual reality (VR-to-VR) communications, IST enables the testing of subjects via interactive communications. It appears that IST will find practical applications in the near future. We examined the utility of IST in medical treatment and psychiatric tests. Psychiatric symptoms reflect human pathos, which in turn are greatly influenced by culture. If these culture-bound symptoms can be adequately communicated between providers and clients of different cultures, we can develop effective telepsychiatric services across different societies and cultures. IST requires high-speed transmission and gigabyte circuits. A pilot project tested the utility of IST (through the use of optical fiber communications on earth) as a basis for experiments via the Gigabit satellite, to be launched in the year 2002.

  16. Rotor blade vortex interaction noise

    NASA Astrophysics Data System (ADS)

    Yu, Yung H.

    2000-02-01

    Blade-vortex interaction noise-generated by helicopter main rotor blades is one of the most severe noise problems and is very important both in military applications and community acceptance of rotorcraft. Research over the decades has substantially improved physical understanding of noise-generating mechanisms, and various design concepts have been investigated to control noise radiation using advanced blade planform shapes and active blade control techniques. The important parameters to control rotor blade-vortex interaction noise and vibration have been identified: blade tip vortex structures and its trajectory, blade aeroelastic deformation, and airloads. Several blade tip design concepts have been investigated for diffusing tip vortices and also for reducing noise. However, these tip shapes have not been able to substantially reduce blade-vortex interaction noise without degradation of rotor performance. Meanwhile, blade root control techniques, such as higher-harmonic pitch control (HHC) and individual blade control (IBC) concepts, have been extensively investigated for noise and vibration reduction. The HHC technique has proved the substantial blade-vortex interaction noise reduction, up to 6 dB, while vibration and low-frequency noise have been increased. Tests with IBC techniques have shown the simultaneous reduction of rotor noise and vibratory loads with 2/rev pitch control inputs. Recently, active blade control concepts with smart structures have been investigated with the emphasis on active blade twist and trailing edge flap. Smart structures technologies are very promising, but further advancements are needed to meet all the requirements of rotorcraft applications in frequency, force, and displacement.

  17. Polyelectrolytes and Their Biological Interactions

    PubMed Central

    Katchalsky, A.

    1964-01-01

    Polyelectrolytes are water-soluble electrically charged polymers. Their properties are determined by the interplay of the electrical forces, the Brownian motion of the macromolecular chain, and intermolecular Van der Waals forces. Charged polyacids or polybases are stretched by the electrostatic forces, as evidenced by increase in solution viscosity, or by the stretching of polyelectrolyte gels. The electrical field of the polyions is neutralized by a dense atmosphere of counter-ions. The counter-ion attraction to the polyions is expressed by a reduction of the osmotic activity of the polyion—the osmotic pressure being only 15 to 20 per cent of the ideal in highly charged polyelectrolytes neutralized by monovalent counter-ions, and as low as 1 to 3 per cent of the ideal for polyvalent counter-ions. Since the ionic atmosphere is only slightly dependent on added low molecular salt, the osmotic pressure of polyelectrolyte salt mixtures is approximately equal to the sum of the osmotic pressure of polyelectrolyte and salt alone. Acidic and basic polyelectrolytes interact electrostatically with precipitation at the point of polymeric electroneutrality. At higher salt concentrations the interaction is inhibited by the screening of polymeric fixed charges. The importance of these interactions in enzymatic processes is discussed. The electrical double layer is polarizable as may be deduced from dielectric and conductometric studies. The polarizability leads to strong dipole formation in an electrical field. These macromolecular dipoles may play a role in the adsorption of polyelectrolytes on charged surfaces. The final part of the paper is devoted to interactions of polyelectrolytes with cell membranes and the gluing of cells to higher aggregates by charged biocolloids. ImagesFigure 17Figure 18Figure 19Figure 20 PMID:14104085

  18. Host-Pathogen Coupled Interactions

    DTIC Science & Technology

    2015-01-04

    AFRL- RH -WP-TP-2015-0012 Host-Pathogen Coupled Interactions Peter J. Robinson C. Eric Hack Jeffery M...them. Qualified requestors may obtain copies of this report from the Defense Technical Information Center (DTIC) (http://www.dtic.mil). (AFRL- RH ...Branch Wright-Patterson AFB OH 45433-5707 10. SPONSOR/MONITOR’S ACRONYM(S) 711 HPW/RHDJ 11. SPONSORING/MONITORING AGENCY REPORT NUMBER AFRL- RH -WP

  19. Galaxy Interaction in Overdense Environments

    NASA Astrophysics Data System (ADS)

    Holman, Derek; Hung, Chao-Ling

    2017-01-01

    Examining protoclusters is an important method for developing our understanding of the formation and evolution of large galaxy clusters found in the local universe. Many of the z≈2-3 protoclusters contain overdensities of dusty star-forming galaxies (DSFG) which have stellar formation rates greater than 100 Msun/year. Due to the short depletion time (≈100Myr) of molecular gas in the DSFGs contained in these protoclusters, the assembly of protoclusters is believed to be a rapid and occasional process. One possible mechanism for this rapid assembly is an enhanced frequency of interaction between galaxies. We analyzed one of these protoclusters at z= 2.1 to determine if the frequency of mergers is affected by the overdense environment. Previous works have shown that galaxies may interact more frequently in overdense environments but do not provide adequate significance to confirm this connection. Using the COSMOS2015 catalog, galaxies in the protocluster are evaluated with the following criteria for merger candidates: existence of neighboring galaxies in a 10-30 kpc radius, agreement of photometric redshift with neighbor(s) within 1σ, and stellar mass ratio calculation for merger candidates in terms of minor mergers (>4:1) and major mergers (1:1 - 4:1). Our analysis confirms that interacting galaxies are found more frequently in overdense environments (δ > 0.5). Based on further analysis using spectroscopic redshifts from the ZFIRE Survey to evaluate the uncertainty present by using the photometric redshifts, we find that σΔ/(1+z_s) = 0.05 for the photometric redshifts from z= 1.50 to z= 2.50. In the future it will be helpful to analyze mergers in other stages of interaction to see if the enhanced merger frequency is still evident.

  20. Strongly interacting parton matter equilibration

    SciTech Connect

    Ozvenchuk, V.; Linnyk, O.; Bratkovskaya, E.; Gorenstein, M.; Cassing, W.

    2012-07-15

    We study the kinetic and chemical equilibration in 'infinite' parton matter within the Parton-Hadron-String Dynamics transport approach. The 'infinite' matter is simulated within a cubic box with periodic boundary conditions initialized at different energy densities. Particle abundances, kinetic energy distributions, and the detailed balance of the off-shell quarks and gluons in the strongly-interacting quarkgluon plasma are addressed and discussed.

  1. Terahertz Technology and Molecular Interactions

    DTIC Science & Technology

    2010-12-16

    fingerprint, as the concentration of the target gas is increased from zero at some concentration the identification statistics rapidly change from ran...REPORT THz Technology and Molecular Interactions 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: The purpose of this project was to explore opportunities...development of compact solid state point sensors for chemical identification with ‘absolute’ specificity, (2) studies of the phenomenology that underlies

  2. Situational simulations in interactive video

    SciTech Connect

    Smith, L.J.

    1991-07-01

    The Westinghouse Hanford Company Advanced Training Technologies section is using situational simulations in several Interactive Video training courses. Two applications of situational simulations will be discussed. In the first, used in the Hanford General Employee Training course, the student evaluates employee's actions in simulations of possible workplace situations. In the second, used in the Criticality Safety course, students must follow well-defined procedures to complete tasks. Design and incorporation of situational simulations will be discussed. 3 refs.

  3. Strongly interacting parton matter equilibration

    NASA Astrophysics Data System (ADS)

    Ozvenchuk, V.; Linnyk, O.; Bratkovskaya, E.; Gorenstein, M.; Cassing, W.

    2012-07-01

    We study the kinetic and chemical equilibration in "infinite" parton matter within the Parton-Hadron-String Dynamics transport approach. The "infinite" matter is simulated within a cubic box with periodic boundary conditions initialized at different energy densities. Particle abundances, kinetic energy distributions, and the detailed balance of the off-shell quarks and gluons in the strongly-interacting quarkgluon plasma are addressed and discussed.

  4. Interactive Image Analysis System Design,

    DTIC Science & Technology

    1982-12-01

    This report describes a design for an interactive image analysis system (IIAS), which implements terrain data extraction techniques. The design... analysis system. Additionally, the system is fully capable of supporting many generic types of image analysis and data processing, and is modularly...employs commercially available, state of the art minicomputers and image display devices with proven software to achieve a cost effective, reliable image

  5. Electron interactions with polar molecules

    SciTech Connect

    Garrett, W.R.

    1981-01-01

    A description is given of a number of the features of discrete and continuous spectra of electrons interacting with polar molecules. Attention is focused on the extent to which theoretical predictions concerning cross sections, resonances, and bound states are strongly influenced by the various approximations that are so ubiquitous in the treatment of such problems. Similarly, threshold scattering and photodetachment processes are examined for the case of weakly bound dipole states whose higher members overlap the continuum.

  6. Interactive cutting path analysis programs

    NASA Technical Reports Server (NTRS)

    Weiner, J. M.; Williams, D. S.; Colley, S. R.

    1975-01-01

    The operation of numerically controlled machine tools is interactively simulated. Four programs were developed to graphically display the cutting paths for a Monarch lathe, Cintimatic mill, Strippit sheet metal punch, and the wiring path for a Standard wire wrap machine. These programs are run on a IMLAC PDS-ID graphic display system under the DOS-3 disk operating system. The cutting path analysis programs accept input via both paper tape and disk file.

  7. Clinical nutrition and drug interactions

    PubMed Central

    Ekincioğlu, Aygin Bayraktar; Demirkan, Kutay

    2013-01-01

    A drug’s plasma level, pharmacological effects or side effects, elimination, physicochemical properties or stability could be changed by interactions of drug-drug or drug-nutrition products in patients who receive enteral or parenteral nutritional support. As a result, patients might experience ineffective outcomes or unexpected effects of therapy (such as drug toxicity, embolism). Stability or incompatibility problems between parenteral nutrition admixtures and drugs might lead to alterations in expected therapeutic responses from drug and/or parenteral nutrition, occlusion in venous catheter or symptoms or mortality due to infusion of composed particles. Compatibilities between parenteral nutrition and drugs are not always guaranteed in clinical practice. Although the list of compatibility or incompatibilities of drugs are published for the use of clinicians in their practices, factors such as composition of parenteral nutrition admixture, drug concentration, contact time in catheter, temperature of the environment and exposure to light could change the status of compatibilities between drugs and nutrition admixtures. There could be substantial clinical changes occurring in the patient’s nutritional status and pharmacological effects of drugs due to interactions between enteral nutrition and drugs. Drug toxicity and ineffective nutritional support might occur as a result of those predictable interactions. Although administration of drugs via feeding tube is a complex and problematic route for drug usage, it is possible to minimise the risk of tube occlusion, decreased effects of drug and drug toxicity by using an appropriate technique. Therefore, it is important to consider pharmacological dosage forms of drugs while administering drugs via a feeding tube. In conclusion, since the pharmacists are well-experienced and more knowledgeable professionals in drugs and drug usage compared to other healthcare providers, it is suggested that provision of information

  8. Curvature Interaction in Collective Space

    NASA Astrophysics Data System (ADS)

    Herrmann, Richard

    2012-12-01

    For the Riemannian space, built from the collective coordinates used within nuclear models, an additional interaction with the metric is investigated, using the collective equivalent to Einstein's curvature scalar. The coupling strength is determined using a fit with the AME2003 ground state masses. An extended finite-range droplet model including curvature is introduced, which generates significant improvements for light nuclei and nuclei in the trans-fermium region.

  9. Acoustoelasticity. [sound-structure interaction

    NASA Technical Reports Server (NTRS)

    Dowell, E. H.

    1977-01-01

    Sound or pressure variations inside bounded enclosures are investigated. Mathematical models are given for determining: (1) the interaction between the sound pressure field and the flexible wall of a Helmholtz resonator; (2) coupled fluid-structural motion of an acoustic cavity with a flexible and/or absorbing wall; (3) acoustic natural modes in multiple connected cavities; and (4) the forced response of a cavity with a flexible and/or absorbing wall. Numerical results are discussed.

  10. Insights into electromagnetic interaction mechanisms.

    PubMed

    Goodman, Reba; Blank, Martin

    2002-07-01

    Low frequency (< 300 Hz) electromagnetic (EM) fields induce biological changes that include effects ranging from increased enzyme reaction rates to increased transcript levels for specific genes. The induction of stress gene HSP70 expression by exposure to EM fields provides insight into how EM fields interact with cells and tissues. Insights into the mechanism(s) are also provided by examination of the interaction of EM fields with moving charges and their influence on enzyme reaction rates in cell-free systems. Biological studies with in vitro model systems have focused, in general, on the nature of the signal transduction pathways involved in response to EM fields. It is likely, however, that EM fields also interact directly with electrons in DNA to stimulate biosynthesis. Identification of an EM field-sensitive DNA sequence in the heat shock 70 (HSP70) promoter, points to the application of EM fields in two biomedical applications: cytoprotection and gene therapy. EM field induction of the stress protein hsp70 may also provide a useful biomarker for establishing a science-based safety standard for the design of cell phones and their transmission towers.

  11. Aeolotopic interactions of globular proteins

    PubMed Central

    Lomakin, Aleksey; Asherie, Neer; Benedek, George B.

    1999-01-01

    Protein crystallization, aggregation, liquid–liquid phase separation, and self-assembly are important in protein structure determination in the industrial processing of proteins and in the inhibition of protein condensation diseases. To fully describe such phase transformations in globular protein solutions, it is necessary to account for the strong spatial variation of the interactions on the protein surface. One difficulty is that each globular protein has its own unique surface, which is crucial for its biological function. However, the similarities amongst the macroscopic properties of different protein solutions suggest that there may exist a generic model that is capable of describing the nonuniform interactions between globular proteins. In this paper we present such a model, which includes the short-range interactions that vary from place to place on the surface of the protein. We show that this aeolotopic model [from the Greek aiolos (“variable”) and topos (“place”)] describes the phase diagram of globular proteins and provides insight into protein aggregation and crystallization. PMID:10449715

  12. Kawaii/Cute Interactive Media

    NASA Astrophysics Data System (ADS)

    Cheok, Adrian David

    Cuteness in interactive systems is a relatively new development, yet having its roots in the aesthetics of many historical and cultural elements. Symbols of cuteness abound in nature as in the creatures of neotenous proportions; drawing in the care and concern of the parent and the care from a protector. We provide an in depth look at the role of cuteness in interactive systems beginning with a history. We particularly focus on the Japanese culture of Kawaii, which has made a large impact around the world, especially in entertainment, fashion, and animation. We then take the approach of defining cuteness in contemporary popular perception. User studies are presented offering an in-depth understanding of key perceptual elements which are identified as cute. This knowledge provides for the possibility to create a cute filter which can transform inputs and automatically create more cute outputs. The development of cute social computing and entertainment projects are discussed as well, providing an insight into the next generation of interactive systems which bring happiness and comfort to users of all ages and cultures through the soft power of cute.

  13. Weak interactions at the SSC

    SciTech Connect

    Chanowitz, M.S.

    1986-03-01

    Prospects for the study of standard model weak interactions at the SSC are reviewed, with emphasis on the unique capability of the SSC to study the mechanism of electroweak symmetry breaking whether the associated new quanta are at the TeV scale or higher. Symmetry breaking by the minimal Higgs mechanism and by related strong interaction dynamical variants is summarized. A set of measurements is outlined that would calibrate the proton structure functions and the backgrounds to new physics. The ability to measure the three weak gauge boson vertex is found to complement LEP II, with measurements extending to larger Q/sup 2/ at a comparable statistical level in detectable decays. B factory physics is briefly reviewed as one example of a possible broad program of high statistics studies of sub-TeV scale phenomena. The largest section of the talk is devoted to the possible manifestations of symmetry breaking in the WW and ZZ production cross sections. Some new results are presented bearing on the ability to detect high mass WW and ZZ pairs. The principal conclusion is that although nonstandard model scenarios are typically more forgiving, the capability to study symmetry breaking in the standard model (and in related strong interaction dynamical variants) requires achieving the SSC design goals of ..sqrt.. s,L = 40Tev, 10/sup 33/cm/sup -2/sec/sup -1/. 28 refs., 5 figs.

  14. Cyclosporine and herbal supplement interactions.

    PubMed

    Colombo, D; Lunardon, L; Bellia, G

    2014-01-01

    Cyclosporine (CyA) is a well-known immunosuppressant with a narrow therapeutic window. Its bioavailability is affected by many other traditional drugs and herbal extracts. Cytochrome P-450 isoenzymes CYP3A4 and CYP3A5 and protein P-glycoprotein (P-gp) are involved in CyA bioavailability. Interactions of CyA with herbal extracts are not well known, but, given their increased concomitant use, it is important to know which extracts, many of which are commonly self-prescribed, can affect CyA blood concentrations. Decreased CyA blood concentration has been shown with St John's wort in case reports and, in vivo animal studies, with ginger, liquorice, scutellariae radix, and quercetin. Increased CyA concentration has been reported in patients with grapefruit juice, chamomile, or berberine, and with cannabidiol or resveratrol in animal studies. Effects of Echinacea and Serenoa repens on CyA levels have not been shown consistently, but concomitant use should be avoided. Although findings from animal studies cannot be directly translated into humans, avoiding concomitant use of herbal extracts is prudent until human clinical studies have ruled out any possible interaction. Clinicians should interview their patients carefully about their use of herbal supplements before CyA administration, and those receiving CyA should be warned about possible interactions between herbal preparations and CyA.

  15. Cyclosporine and Herbal Supplement Interactions

    PubMed Central

    Colombo, D.; Lunardon, L.; Bellia, G.

    2014-01-01

    Cyclosporine (CyA) is a well-known immunosuppressant with a narrow therapeutic window. Its bioavailability is affected by many other traditional drugs and herbal extracts. Cytochrome P-450 isoenzymes CYP3A4 and CYP3A5 and protein P-glycoprotein (P-gp) are involved in CyA bioavailability. Interactions of CyA with herbal extracts are not well known, but, given their increased concomitant use, it is important to know which extracts, many of which are commonly self-prescribed, can affect CyA blood concentrations. Decreased CyA blood concentration has been shown with St John's wort in case reports and, in vivo animal studies, with ginger, liquorice, scutellariae radix, and quercetin. Increased CyA concentration has been reported in patients with grapefruit juice, chamomile, or berberine, and with cannabidiol or resveratrol in animal studies. Effects of Echinacea and Serenoa repens on CyA levels have not been shown consistently, but concomitant use should be avoided. Although findings from animal studies cannot be directly translated into humans, avoiding concomitant use of herbal extracts is prudent until human clinical studies have ruled out any possible interaction. Clinicians should interview their patients carefully about their use of herbal supplements before CyA administration, and those receiving CyA should be warned about possible interactions between herbal preparations and CyA. PMID:24527031

  16. Meteoroid-bumper interactions program

    NASA Technical Reports Server (NTRS)

    Gough, P. S.

    1970-01-01

    An investigation has been made of the interaction of meteoroids with shielded structures. The interaction has been simulated by the impact of Lexan cylinders onto lead shields in order to provide the vaporous debris believed to be created by meteoroid impact on a space vehicle. Shock compression data for Lexan was determined. This, in combination with the known shock compression data for the lead shield, has permitted the definition of the initial high pressure states in the impacted projectile and shield. The debris from such impact events has been permitted to interact with aluminum main walls. The walls were chosen to be sufficiently large to be effectively infinite in diameter compared to the loaded area. The thickness of the wall and the spacing from the shield were varied to determine the effect of these parameters. In addition, the effect of having a body of water behind the wall has been assessed. Measurements of the stagnation pressure in the debris cloud have been made and correlated with the response of the main wall.

  17. Probing protein-sugar interactions.

    PubMed

    Ebel, C; Eisenberg, H; Ghirlando, R

    2000-01-01

    We have investigated the partial specific volumes (2) (ml/g), hydration, and cosolvent interactions of rabbit muscle aldolase by equilibrium sedimentation in the analytical ultracentrifuge and by direct density increment (partial differential/partial differentialc(2))(mu) measurements over a range of sugar concentrations and temperature. In a series of sugars increasing in size, glucose, sucrose, raffinose, and alpha-cyclodextrin, (partial differential/ partial differentialc(2))(mu) decreases linearly with the solvent density rho(0). These sugar cosolvents do not interact with the protein; however, the interaction parameter B(1) (g water/g protein) mildly increases with increasing sugar size. The experimental B(1) values are smaller than values calculated by excluded volume (rolling ball) considerations. B(1) relates to hydration in this and in other instances studied. It decreases with increasing temperature, leading to an increase in (2) due to reduced water of hydration electrostriction. The density increments (partial differential/ partial differentialc(2))(mu), however, decrease in concave up form in the case of glycerol and in concave down form for trehalose, leading to more complex behavior in the case of carbohydrates playing a biological role as osmolytes and antifreeze agents. A critical discussion, based on the thermodynamics of multicomponent solutions, is presented.

  18. PREFACE: Cell-substrate interactions Cell-substrate interactions

    NASA Astrophysics Data System (ADS)

    Gardel, Margaret; Schwarz, Ulrich

    2010-05-01

    One of the most striking achievements of evolution is the ability to build cellular systems that are both robust and dynamic. Taken by themselves, both properties are obvious requirements: robustness reflects the fact that cells are there to survive, and dynamics is required to adapt to changing environments. However, it is by no means trivial to understand how these two requirements can be implemented simultaneously in a physical system. The long and difficult quest to build adaptive materials is testimony to the inherent difficulty of this goal. Here materials science can learn a lot from nature, because cellular systems show that robustness and dynamics can be achieved in a synergetic fashion. For example, the capabilities of tissues to repair and regenerate are still unsurpassed in the world of synthetic materials. One of the most important aspects of the way biological cells adapt to their environment is their adhesive interaction with the substrate. Numerous aspects of the physiology of metazoan cells, including survival, proliferation, differentiation and migration, require the formation of adhesions to the cell substrate, typically an extracellular matrix protein. Adhesions guide these diverse processes both by mediating force transmission from the cell to the substrate and by controlling biochemical signaling pathways. While the study of cell-substrate adhesions is a mature field in cell biology, a quantitative biophysical understanding of how the interactions of the individual molecular components give rise to the rich dynamics and mechanical behaviors observed for cell-substrate adhesions has started to emerge only over the last decade or so. The recent growth of research activities on cell-substrate interactions was strongly driven by the introduction of new physical techniques for surface engineering into traditional cell biological work with cell culture. For example, microcontact printing of adhesive patterns was used to show that cell fate depends

  19. Resonant and secular orbital interactions

    NASA Astrophysics Data System (ADS)

    Zhang, Ke

    In stable solar systems, planets remain in nearly elliptical orbits around their stars. Over longer timescales, however, their orbital shapes and sizes change due to mutual gravitational perturbations. Orbits of satellites around a planet vary for the same reason. Because of their interactions, the orbits of planets and satellites today are different from what they were earlier. In order to determine their original orbits, which are critical constraints on formation theories, it is crucial to understand how orbits evolve over the age of the Solar System. Depending on their timescale, we classify orbital interactions as either short-term (orbital resonances) or long-term (secular evolution). My work involves examples of both interaction types. Resonant history of the small Neptunian satellites. In satellite systems, tidal migration brings satellite orbits in and out of resonances. During a resonance passage, satellite orbits change dramatically in a very short period of time. We investigate the resonant history of the six small Neptunian moons. In this unique system, the exotic orbit of the large captured Triton (with a circular, retrograde, and highly tilted orbit) influences the resonances among the small satellites very strongly. We derive an analytical framework which can be applied to Neptune's satellites and to similar systems. Our numerical simulations explain the current orbital tilts of the small satellites as well as constrain key physical parameters of both Neptune and its moons. Secular orbital interactions during eccentricity damping. Long-term periodic changes of orbital shape and orientation occur when two or more planets orbit the same star. The variations of orbital elements are superpositions of the same number of fundamental modes as the number of planets in the system. We investigate how this effect interacts with other perturbations imposed by external disturbances, such as the tides and relativistic effects. Through analytical studies of a

  20. Bidimensional spectroscopy of interacting galaxies

    NASA Astrophysics Data System (ADS)

    Chatzichristou, E. T.

    We have undertaken a program of studying the central few kpc regions of interacting/merger candidates, that were specifically chosen to have a range of nuclear activity, IR properties and strength of interaction. Here we present data obtained using the integral field spectrograph ARGUS, on the CFHT for few of these objects. Unlike slit spectroscopy, these data provide a direct two-dimensional picture of the wavelength-dependant emission and absorption line properties of these galaxies. The main conclusions are: (1) Mkn 789 is a recent merger product, undergoing a strong burst of star formation, while the older stellar component did not have yet the time to relax. It has no compact nuclear structure and its strong star formation powers a large scale outflow ("superwind"), which gives characteristic multiple profiles. Mkn 463 on the other hand, appears at an intermediate merging stage where at least one of its two visible nuclei had time to become activated, showing a Seyfert-like spectrum. The distinct kinematic feature here is a strongly blueshifted component that is interpreted in terms of bowshocks driven by a radio jet into the ambient gas. (2) UGC 3995 is the brightest member of a pair of interacting spirals, has a low-ionization, Seyfert-like spectrum. The velocity field is smooth, characteristic of a retrogradely rotating disk, but we find rotation of the kinematic axis with wavelength, that correspond to isophotal distortions and an obvious line profile substructure. It seems that this is a distinct kinematic feature in Seyfert-like nuclei independently of their interaction stage, indicating radial gas motions that might be related to the activation of the central engine. (3) Both mergers (Mkn 463, Mkn 789) have higher IR activity, as expressed by the LFIR excess and "warm" far-IR colours, among the objects in our sample. This seems to be independent of the nature of the central engine. On the other hand, the 25 microns characteristic excess emission of

  1. Research in elementary particle physics. [Ohio State Univ. , Columbus

    SciTech Connect

    Not Available

    1992-01-01

    Experimental and theoretical work on high energy physics is reviewed. Included are preparations to study high-energy electron-proton interactions at HERA, light-cone QCD, decays of charm and beauty particles, neutrino oscillation, electron-positron interactions at CLEO II, detector development, and astrophysics and cosmology.

  2. Research in elementary particle physics. Annual report, January 1--October 31, 1992

    SciTech Connect

    Not Available

    1992-11-01

    Experimental and theoretical work on high energy physics is reviewed. Included are preparations to study high-energy electron-proton interactions at HERA, light-cone QCD, decays of charm and beauty particles, neutrino oscillation, electron-positron interactions at CLEO II, detector development, and astrophysics and cosmology.

  3. Interacting Korteweg-de Vries Equations and Attractive Soliton Interaction

    NASA Astrophysics Data System (ADS)

    Yoneyama, T.

    1984-12-01

    By a physically natural way, the Korteweg-de Vries (KdV) equation is extended to obtain textit{interacting} (Int) KdV equations. They can also be regarded as results of a decoupling of the original KdV equation. By introducing textit{new operators}, solutions of the Int KdV equations are obtained starting with the exact KdV N-soliton solution. The KdV N-soliton solution is decomposed into a textit{simple sum} of the solutions of the Int KdV equations, each of which is regarded as a soliton suffering much deformation when another soliton (other solitons) comes near in space. These single solitons as textit{classical waves} interact textit{attractively} and eventually become apart in space textit{without} losing their identities. The relation to the inverse scattering method is also discussed in detail. Further, ``partical'' Lax forms corresponding to the Int KdV equations are shown.

  4. Predator vs aliens: bacteria interactions with Acanthamoeba.

    PubMed

    Khan, Naveed Ahmed; Siddiqui, Ruqaiyyah

    2014-06-01

    By interactions with other microbes, free-living amoebae play a significant role in microbiology, environmental biology, physiology, cellular interactions, ecology and evolution. Here, we discuss astonishing interactions of bacteria and amoebae, in the light of evolution and functional aspects impacting human health. In favourable environmental conditions, the interaction of Acanthamoeba with non-virulent bacteria results in lysis of the bacteria. However, the interaction with weak-virulent bacteria results in a symbiotic relationship or amoebal lysis may occur. The microbial survival of amoebae in harsh environments, ability to interact with bacteria, and their ability to aid transmission to susceptible hosts is of great concern to human, animal and ecosystem health.

  5. Interactive modeling of storm impact

    NASA Astrophysics Data System (ADS)

    van Rooijen, A.; Baart, F.; Roelvink, J. A.; Donchyts, G.; Scheel, F.; de Boer, W.

    2014-12-01

    In the past decades the impact of storms on the coastal zone has increasingly drawn the attention of policy makers and coastal planners, engineers and researchers. The mean reason for this interest is the high density of the world's population living near the ocean, in combination with climate change. Due to sea level rise and extremer weather conditions, many of the world's coastlines are becoming more vulnerable to the potential of flooding. Currently it is common practice to predict storm impact using physics-based numerical models. The numerical model utilizes several inputs (e.g. bathymetry, waves, surge) to calculate the impact on the coastline. Traditionally, the numerical modeller takes the following three steps: schematization/model setup, running and post-processing. This process generally has a total feedback time in the order of hours to days, and is suitable for so-called confirmatory modelling.However, often models are applied as an exploratory tool, in which the effect of e.g. different hydraulic conditions, or measures is investigated. The above described traditional work flow is not the most efficient method for exploratory modelling. Interactive modelling lets users adjust a simulation while running. For models typically used for storm impact studies (e.g. XBeach, Delft3D, D-Flow FM), the user can for instance change the storm surge level, wave conditions, or add a measure such as a nourishment or a seawall. The model will take the adjustments into account immediately, and will directly compute the effect. Using this method, tools can be developed in which stakeholders (e.g. coastal planners, policy makers) are in control and together evaluate ideas by interacting with the model. Here we will show initial results for interactive modelling with a storm impact model.

  6. Hierarchical modeling of protein interactions.

    PubMed

    Kurcinski, Mateusz; Kolinski, Andrzej

    2007-07-01

    A novel approach to hierarchical peptide-protein and protein-protein docking is described and evaluated. Modeling procedure starts from a reduced space representation of proteins and peptides. Polypeptide chains are represented by strings of alpha-carbon beads restricted to a fine-mesh cubic lattice. Side chains are represented by up to two centers of interactions, corresponding to beta-carbons and the centers of mass of the remaining portions of the side groups, respectively. Additional pseudoatoms are located in the centers of the virtual bonds connecting consecutive alpha carbons. These pseudoatoms support a model of main-chain hydrogen bonds. Docking starts from a collection of random configurations of modeled molecules. Interacting molecules are flexible; however, higher accuracy models are obtained when the conformational freedom of one (the larger one) of the assembling molecules is limited by a set of weak distance restraints extracted from the experimental (or theoretically predicted) structures. Sampling is done by means of Replica Exchange Monte Carlo method. Afterwards, the set of obtained structures is subject to a hierarchical clustering. Then, the centroids of the resulting clusters are used as scaffolds for the reconstruction of the atomic details. Finally, the all-atom models are energy minimized and scored using classical tools of molecular mechanics. The method is tested on a set of macromolecular assemblies consisting of proteins and peptides. It is demonstrated that the proposed approach to the flexible docking could be successfully applied to prediction of protein-peptide and protein-protein interactions. The obtained models are almost always qualitatively correct, although usually of relatively low (or moderate) resolution. In spite of this limitation, the proposed method opens new possibilities of computational studies of macromolecular recognition and mechanisms of assembly of macromolecular complexes.

  7. Interactive 3D Mars Visualization

    NASA Technical Reports Server (NTRS)

    Powell, Mark W.

    2012-01-01

    The Interactive 3D Mars Visualization system provides high-performance, immersive visualization of satellite and surface vehicle imagery of Mars. The software can be used in mission operations to provide the most accurate position information for the Mars rovers to date. When integrated into the mission data pipeline, this system allows mission planners to view the location of the rover on Mars to 0.01-meter accuracy with respect to satellite imagery, with dynamic updates to incorporate the latest position information. Given this information so early in the planning process, rover drivers are able to plan more accurate drive activities for the rover than ever before, increasing the execution of science activities significantly. Scientifically, this 3D mapping information puts all of the science analyses to date into geologic context on a daily basis instead of weeks or months, as was the norm prior to this contribution. This allows the science planners to judge the efficacy of their previously executed science observations much more efficiently, and achieve greater science return as a result. The Interactive 3D Mars surface view is a Mars terrain browsing software interface that encompasses the entire region of exploration for a Mars surface exploration mission. The view is interactive, allowing the user to pan in any direction by clicking and dragging, or to zoom in or out by scrolling the mouse or touchpad. This set currently includes tools for selecting a point of interest, and a ruler tool for displaying the distance between and positions of two points of interest. The mapping information can be harvested and shared through ubiquitous online mapping tools like Google Mars, NASA WorldWind, and Worldwide Telescope.

  8. Effective Interactions for Light Nuclei

    NASA Astrophysics Data System (ADS)

    Caldwell, Bryan R.

    The G-matrix technique in which one is able to easily calculate ground and excited states of many-body systems is used to calculate the ground state energies and some excited levels of ^3H and ^4He. Energy independent effective interactions are obtained for these nuclei using the technique of Suzuki and Lee which requires the G-matrix and its derivatives with respect to starting energy. It is found that accurate energy derivatives of the G-matrix are necessary to obtain energy independence and thus analytic expressions are presented for these derivatives in both center-of-mass/relative and shell model coordinate systems. Several rules of thumb are given pertaining to the convergence criteria in both coordinate systems. Further, since the G-matrix includes only intra -channel two-body correlations outside the active space, we explore the effect on the binding energies when the active space is enlarged to include several major shells. By enlarging the active space, we hope to include the most important many-body correlations explicitly. It is found that when the active space includes more than 2 major shells, the effective interaction is well approximated by the G-matrix. Our results essentially agree with exact Faddeev calculations for ^3 H but underbind by about.5 MeV in ^4 He as compared to exact Yabukovsky and Green function Monte Carlo calculations. A possible reason for this underbinding, the inclusion of unlinked diagrams in the energy expansion, is studied. The energy independent G-matrix technique is then applied to the p-shell (^5He, ^6Li and ^7Li) where the active space includes all excitations up to 2 hbaromega. Zero, one, two and three -body effective interactions are extracted and it is found that a schematic two-parameter three-body potential can be used to approximate the effective three-body potential that results from the truncation of the active space.

  9. Fashion, Cooperation, and Social Interactions

    PubMed Central

    Cao, Zhigang; Gao, Haoyu; Qu, Xinglong; Yang, Mingmin; Yang, Xiaoguang

    2013-01-01

    Fashion plays such a crucial rule in the evolution of culture and society that it is regarded as a second nature to the human being. Also, its impact on economy is quite nontrivial. On what is fashionable, interestingly, there are two viewpoints that are both extremely widespread but almost opposite: conformists think that what is popular is fashionable, while rebels believe that being different is the essence. Fashion color is fashionable in the first sense, and Lady Gaga in the second. We investigate a model where the population consists of the afore-mentioned two groups of people that are located on social networks (a spatial cellular automata network and small-world networks). This model captures two fundamental kinds of social interactions (coordination and anti-coordination) simultaneously, and also has its own interest to game theory: it is a hybrid model of pure competition and pure cooperation. This is true because when a conformist meets a rebel, they play the zero sum matching pennies game, which is pure competition. When two conformists (rebels) meet, they play the (anti-) coordination game, which is pure cooperation. Simulation shows that simple social interactions greatly promote cooperation: in most cases people can reach an extraordinarily high level of cooperation, through a selfish, myopic, naive, and local interacting dynamic (the best response dynamic). We find that degree of synchronization also plays a critical role, but mostly on the negative side. Four indices, namely cooperation degree, average satisfaction degree, equilibrium ratio and complete ratio, are defined and applied to measure people’s cooperation levels from various angles. Phase transition, as well as emergence of many interesting geographic patterns in the cellular automata network, is also observed. PMID:23382799

  10. Fashion, cooperation, and social interactions.

    PubMed

    Cao, Zhigang; Gao, Haoyu; Qu, Xinglong; Yang, Mingmin; Yang, Xiaoguang

    2013-01-01

    Fashion plays such a crucial rule in the evolution of culture and society that it is regarded as a second nature to the human being. Also, its impact on economy is quite nontrivial. On what is fashionable, interestingly, there are two viewpoints that are both extremely widespread but almost opposite: conformists think that what is popular is fashionable, while rebels believe that being different is the essence. Fashion color is fashionable in the first sense, and Lady Gaga in the second. We investigate a model where the population consists of the afore-mentioned two groups of people that are located on social networks (a spatial cellular automata network and small-world networks). This model captures two fundamental kinds of social interactions (coordination and anti-coordination) simultaneously, and also has its own interest to game theory: it is a hybrid model of pure competition and pure cooperation. This is true because when a conformist meets a rebel, they play the zero sum matching pennies game, which is pure competition. When two conformists (rebels) meet, they play the (anti-) coordination game, which is pure cooperation. Simulation shows that simple social interactions greatly promote cooperation: in most cases people can reach an extraordinarily high level of cooperation, through a selfish, myopic, naive, and local interacting dynamic (the best response dynamic). We find that degree of synchronization also plays a critical role, but mostly on the negative side. Four indices, namely cooperation degree, average satisfaction degree, equilibrium ratio and complete ratio, are defined and applied to measure people's cooperation levels from various angles. Phase transition, as well as emergence of many interesting geographic patterns in the cellular automata network, is also observed.

  11. Detecting weakly interacting massive particles.

    NASA Astrophysics Data System (ADS)

    Drukier, A. K.; Gelmini, G. B.

    The growing synergy between astrophysics, particle physics, and low background experiments strengthens the possibility of detecting astrophysical non-baryonic matter. The idea of direct detection is that an incident, massive weakly interacting particle could collide with a nucleus and transfer an energy that could be measured. The present low levels of background achieved by the PNL/USC Ge detector represent a new technology which yields interesting bounds on Galactic cold dark matter and on light bosons emitted from the Sun. Further improvements require the development of cryogenic detectors. The authors analyse the practicality of such detectors, their optimalization and background suppression using the "annual modulation effect".

  12. The joy of interactive modeling

    NASA Astrophysics Data System (ADS)

    Donchyts, Gennadii; Baart, Fedor; van Dam, Arthur; Jagers, Bert

    2013-04-01

    The conventional way of working with hydrodynamical models usually consists of the following steps: 1) define a schematization (e.g., in a graphical user interface, or by editing input files) 2) run model from start to end 3) visualize results 4) repeat any of the previous steps. This cycle commonly takes up from hours to several days. What if we can make this happen instantly? As most of the research done using numerical models is in fact qualitative and exploratory (Oreskes et al., 1994), why not use these models as such? How can we adapt models so that we can edit model input, run and visualize results at the same time? More and more, interactive models become available as online apps, mainly for demonstration and educational purposes. These models often simplify the physics behind flows and run on simplified model geometries, particularly when compared with state-of-the-art scientific simulation packages. Here we show how the aforementioned conventional standalone models ("static, run once") can be transformed into interactive models. The basic concepts behind turning existing (conventional) model engines into interactive engines are the following. The engine does not run the model from start to end, but is always available in memory, and can be fed by new boundary conditions, or state changes at any time. The model can be run continuously, per step, or up to a specified time. The Hollywood principle dictates how the model engine is instructed from 'outside', instead of the model engine taking all necessary actions on its own initiative. The underlying techniques that facilitate these concepts are introspection of the computation engine, which exposes its state variables, and control functions, e.g. for time stepping, via a standardized interface, such as BMI (Peckam et. al., 2012). In this work we have used a shallow water flow model engine D-Flow Flexible Mesh. The model was converted from executable to a library, and coupled to the graphical modelling

  13. The hyperon-nucleon interaction

    NASA Astrophysics Data System (ADS)

    Haidenbauer, J.

    2007-11-01

    Results of two recent hyperon-nucleon interaction potentials, both developed by the Bonn-Jülich group, are presented that are derived either in the conventional meson-exchange picture or within leading order chiral effective field theory. The chiral potential consists of one-pseudoscalar-meson exchanges and non-derivative four-baryon contact terms. The most salient feature of the new meson-exchange hyperon-nucleon model is that the contributions in the scalar-isoscalar (σ) and vector-isovector (ρ) exchange channels are constrained by a microscopic model of correlated ππ and KK¯ exchange.

  14. Interactive computerized air combat opponent

    NASA Technical Reports Server (NTRS)

    Hankins, W. W., III

    1976-01-01

    A computer program developed to fly interactive one-on-one simulated air combat maneuvers against human pilots is described. The program which is called Adaptive Maneuvering Logic (AML), is being used in the National Aeronautics and Space Administration (NASA) Langley Research Center's Differential Maneuvering Simulator. The basic control logic evaluates the relative states of the two aircraft and reacts by choosing the best of several elemental maneuvers. Pilot comments and results obtained when the computer was flown against combat-qualified fighter pilots indicate that the program performs realistic maneuvers and offers a very competitive standard pilot.

  15. Multigraph: Reusable Interactive Data Graphs

    NASA Astrophysics Data System (ADS)

    Phillips, M. B.

    2010-12-01

    There are surprisingly few good software tools available for presenting time series data on the internet. The most common practice is to use a desktop program such as Excel or Matlab to save a graph as an image which can be included in a web page like any other image. This disconnects the graph from the data in a way that makes updating a graph with new data a cumbersome manual process, and it limits the user to one particular view of the data. The Multigraph project defines an XML format for describing interactive data graphs, and software tools for creating and rendering those graphs in web pages and other internet connected applications. Viewing a Multigraph graph is extremely simple and intuitive, and requires no instructions; the user can pan and zoom by clicking and dragging, in a familiar "Google Maps" kind of way. Creating a new graph for inclusion in a web page involves writing a simple XML configuration file. Multigraph can read data in a variety of formats, and can display data from a web service, allowing users to "surf" through large data sets, downloading only those the parts of the data that are needed for display. The Multigraph XML format, or "MUGL" for short, provides a concise description of the visual properties of a graph, such as axes, plot styles, data sources, labels, etc, as well as interactivity properties such as how and whether the user can pan or zoom along each axis. Multigraph reads a file in this format, draws the described graph, and allows the user to interact with it. Multigraph software currently includes a Flash application for embedding graphs in web pages, a Flex component for embedding graphs in larger Flex/Flash applications, and a plugin for creating graphs in the WordPress content management system. Plans for the future include a Java version for desktop viewing and editing, a command line version for batch and server side rendering, and possibly Android and iPhone versions. Multigraph is currently in use on several web

  16. QCD inequalities for hadron interactions.

    PubMed

    Detmold, William

    2015-06-05

    We derive generalizations of the Weingarten-Witten QCD mass inequalities for particular multihadron systems. For systems of any number of identical pseudoscalar mesons of maximal isospin, these inequalities prove that near threshold interactions between the constituent mesons must be repulsive and that no bound states can form in these channels. Similar constraints in less symmetric systems are also extracted. These results are compatible with experimental results (where known) and recent lattice QCD calculations, and also lead to a more stringent bound on the nucleon mass than previously derived, m_{N}≥3/2m_{π}.

  17. Interactive image-guided neurosurgery.

    PubMed

    Galloway, R L; Maciunas, R J; Edwards, C A

    1992-12-01

    Interactive image-guided (IIG) surgery involves the synchronal display of the tip of a surgical device on preoperative scans. This display allows the surgeon to locate the present surgical position relative to the final site of surgical interest. We have developed a technique for IIG surgery device based on a six-degree-of-freedom articulated arm. Design accuracy for the arm is less than 0.1 mm and the present implementation has a submillimetric accuracy. The display can show the surgical position on any tomographic image set with simultaneous display on up to three image sets. Laboratory results and clinical applications are discussed.

  18. Supporting collaborative computing and interaction

    SciTech Connect

    Agarwal, Deborah; McParland, Charles; Perry, Marcia

    2002-05-22

    To enable collaboration on the daily tasks involved in scientific research, collaborative frameworks should provide lightweight and ubiquitous components that support a wide variety of interaction modes. We envision a collaborative environment as one that provides a persistent space within which participants can locate each other, exchange synchronous and asynchronous messages, share documents and applications, share workflow, and hold videoconferences. We are developing the Pervasive Collaborative Computing Environment (PCCE) as such an environment. The PCCE will provide integrated tools to support shared computing and task control and monitoring. This paper describes the PCCE and the rationale for its design.

  19. Capillary interactions in Pickering emulsions

    NASA Astrophysics Data System (ADS)

    Guzowski, J.; Tasinkevych, M.; Dietrich, S.

    2011-09-01

    The effective capillary interaction potentials for small colloidal particles trapped at the surface of liquid droplets are calculated analytically. Pair potentials between capillary monopoles and dipoles, corresponding to particles floating on a droplet with a fixed center of mass and subjected to external forces and torques, respectively, exhibit a repulsion at large angular separations and an attraction at smaller separations, with the latter resembling the typical behavior for flat interfaces. This change of character is not observed for quadrupoles, corresponding to free particles on a mechanically isolated droplet. The analytical results are compared with the numerical minimization of the surface free energy of the droplet in the presence of spherical or ellipsoidal particles.

  20. Interacting particle systems on graphs

    NASA Astrophysics Data System (ADS)

    Sood, Vishal

    In this dissertation, the dynamics of socially or biologically interacting populations are investigated. The individual members of the population are treated as particles that interact via links on a social or biological network represented as a graph. The effect of the structure of the graph on the properties of the interacting particle system is studied using statistical physics techniques. In the first chapter, the central concepts of graph theory and social and biological networks are presented. Next, interacting particle systems that are drawn from physics, mathematics and biology are discussed in the second chapter. In the third chapter, the random walk on a graph is studied. The mean time for a random walk to traverse between two arbitrary sites of a random graph is evaluated. Using an effective medium approximation it is found that the mean first-passage time between pairs of sites, as well as all moments of this first-passage time, are insensitive to the density of links in the graph. The inverse of the mean-first passage time varies non-monotonically with the density of links near the percolation transition of the random graph. Much of the behavior can be understood by simple heuristic arguments. Evolutionary dynamics, by which mutants overspread an otherwise uniform population on heterogeneous graphs, are studied in the fourth chapter. Such a process underlies' epidemic propagation, emergence of fads, social cooperation or invasion of an ecological niche by a new species. The first part of this chapter is devoted to neutral dynamics, in which the mutant genotype does not have a selective advantage over the resident genotype. The time to extinction of one of the two genotypes is derived. In the second part of this chapter, selective advantage or fitness is introduced such that the mutant genotype has a higher birth rate or a lower death rate. This selective advantage leads to a dynamical competition in which selection dominates for large populations