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Sample records for chimera 4pi detector

  1. Particle identification method in the CsI(Tl) scintillator used for the CHIMERA 4 pi detector

    CERN Document Server

    Alderighi, M; Basssini, R; Berceanu, I; Blicharska, J; Boiano, C; Borderie, B; Bougault, R; Bruno, M; Cali, C; Cardella, G; Cavallaro, S; D'Agostino, M; D'andrea, M; Dayras, R; De Filippo, E; Fichera, F; Geraci, E; Giustolisi, F; Grzeszczuk, A; Guardone, N; Guazzoni, P; Guinet, D; Iacono-Manno, M; Kowalski, S; La Guidara, E; Lanchais, A L; Lanzalone, G; Lanzanò, G; Le Neindre, N; Li, S; Maiolino, C; Majka, Z; Manfredi, G; Nicotra, D; Paduszynski, T; Pagano, A; Papa, M; Petrovici, C M; Piasecki, E; Pirrone, S; Politi, G; Pop, A; Porto, F; Rivet, M F; Rosato, E; Sacca, G; Sechi, G; Simion, V; Sperduto, M L; Steckmeyer, J C; Trifiró, A; Trimarchi, M; Urso, S; Vannini, G; Vigilante, M; Wilczynski, J; Wu, H; Xiao, Z; Zetta, L; Zipper, W

    2002-01-01

    The charged particle identification obtained by the analysis of signals coming from the CsI(Tl) detectors of the CHIMERA 4 pi heavy-ion detector is presented. A simple double-gate integration method, with the use of the cyclotron radiofrequency as reference time, results in low thresholds for isotopic particle identification. The dependence of the identification quality on the gate generation timing is discussed. Isotopic identification of light ions up to Beryllium is clearly seen. For the first time also the identification of Z=5 particles is observed. The identification of neutrons interacting with CsI(Tl) by (n,alpha) and (n,gamma) reactions is also discussed.

  2. Experimental effects on dynamics and thermodynamics in nuclear reactions on the symmetry energy as seen by the CHIMERA 4$\\pi$ detector

    CERN Document Server

    De Filippo, E

    2013-01-01

    Heavy ion collisions have been widely used in the last decade to constraint the parameterizations of the symmetry energy term of nuclear equation of state (EOS) for asymmetric nuclear matter as a function of baryonic density. In the Fermi energy domain one is faced with variations of the density within a narrow range of values around the saturation density $\\rho_0$=0.16 fm$^{-3}$ down towards sub-saturation densities. The experimental observables which are sensitive to the symmetry energy are constructed starting from the detected light particles, clusters and heavy fragments that, in heavy ion collisions, are generally produced by different emission mechanisms at different stages and time scales of the reaction. In this review the effects of dynamics and thermodynamics on the symmetry energy in nuclear reactions are discussed and characterized using an overview of the data taken so far with the CHIMERA multi-detector array.

  3. A 4[pi] charged-particle detector array for light-ion-induced nuclear fragmentation studies

    Energy Technology Data Exchange (ETDEWEB)

    Kwiatkowski, K. (Departments of Chemistry and Physics and IUCF, Indiana University, Bloomington, IN 47405 (United States)); Alexander, A. (Departments of Chemistry and Physics and IUCF, Indiana University, Bloomington, IN 47405 (United States)); Bracken, D.S. (Departments of Chemistry and Physics and IUCF, Indiana University, Bloomington, IN 47405 (United States)); Brzychczyk, J. (Departments of Chemistry and Physics and IUCF, Indiana University, Bloomington, IN 47405 (United States)); Dorsett, J. (Departments of Chemistry and Physics and IUCF, Indiana University, Bloomington, IN 47405 (United States)); Ensman, R. (Departments of Chemistry and Physics and IUCF, Indiana University, Bloomington, IN 47405 (United States)); Foxford, E.R. (Departments of Chemistry and Physics and IUCF, Indiana University, Bloomington, IN 47405 (United States)); Hamilton, T. (Departments of Chemistry and Physics and IUCF, Indiana University, Bloomington, IN 47405 (United States)); Komisarcik, K. (Dep

    1994-12-30

    Operating characteristics of the Indiana Silicon Sphere 4[pi] detector array are outlined. The detector geometry is spherical, with 90 telescopes in the forward hemisphere and 72 at backward angles, covering a total solid angle of 74% of 4[pi]. Each telescope consists of a simple gas-ion chamber, operated with C[sub 3]F[sub 8] gas, followed by a 0.5 mm thick ion-implanted silicon detector and a 28 mm CsI(Tl) crystal, readout by a photodiode. Custom-built bias supplies and NIM preamp/shaper modules were used in conjunction with commercial CFD, TDC and ADC CAMAC units. ((orig.))

  4. Hot nuclei studies with a 4PI-neutron detector

    International Nuclear Information System (INIS)

    When studying the behavior of hot nuclei, the challenge is twofold: how are they formed in nucleus-nucleus collisions and how do they decay. Systematic studies have been undertaken at GANIL by bombarding heavy targets (Au, Th) with intermediate energy projectiles (27, 35, 44 and 77 MeV/u Ar and 32 MeV/u Kr). For such neutron rich systems the thermalized energy can be roughly evaluated simply by measuring the multiplicity of evaporated neutrons using a 4 π, Gd loaded, liquid scintillator detector. The influence of the bombarding energy and projectile mass on the energy dissipation has been investigated for different exit channels and special emphasis has been put in the study of the most dissipative collisions. The thermal energy, derived by summing the energy removed by both evaporated neutrons and light charged particles is shown to saturate at E* ≅ 650 MeV in the Ar induced reactions between 27 and 77 MeV/u, in good consistency with the predictions of semi-classical Landau-Vlasov calculations

  5. DANCE : a 4[pi] barium fluoride detector for measuring neutron capture on unstable nuclei /.

    Energy Technology Data Exchange (ETDEWEB)

    Ullmann, J. L. (John L.); Haight, Robert C.; Hunt, L. F. (Lloyd F.); Reifarth, R. (Rene); Rundberg, R. S. (Robert S.); Bredeweg, T. A. (Todd A); Fowler, Malcolm M.; Miller, G. G. (Geoffrey G.); Heil, M.; Käppeler, F. (Franz); Chamberlin, E. P. (Edwin P.)

    2002-01-01

    Measurements of neutron capture on unstable nuclei are important for studies of s-process nucleosynthesis, nuclear waste transmutation, and stewardship science. A 160-element, 4{pi} barium fluoride detector array, and associated neutron flight path, is being constructed to make capture measurements at the moderated neutron spallation source at LANSCE. Measurements can be made on as little as 1 mg of sample material over energies from near thermal to near 100 keV. The design of the DANCE array is described and neutron flux measurements from flight path commissioning are shown. The array is expected to be complete by the end of 2002.

  6. The Indiana silicon sphere 4{pi} charged-particle detector array

    Energy Technology Data Exchange (ETDEWEB)

    Kwiatkowski, K. [Indiana Univ., Bloomington, IN (United States). Dept. of Chem. and Phys. and IUCF; Bracken, D.S. [Indiana Univ., Bloomington, IN (United States). Dept. of Chem. and Phys. and IUCF; Morley, K.B. [Indiana Univ., Bloomington, IN (United States). Dept. of Chem. and Phys. and IUCF; Brzychczyk, J. [Indiana Univ., Bloomington, IN (United States). Dept. of Chem. and Phys. and IUCF; Renshaw Foxford, E. [Indiana Univ., Bloomington, IN (United States). Dept. of Chem. and Phys. and IUCF; Komisarcik, K. [Indiana Univ., Bloomington, IN (United States). Dept. of Chem. and Phys. and IUCF; Viola, V.E. [Indiana Univ., Bloomington, IN (United States). Dept. of Chem. and Phys. and IUCF; Yoder, N.R. [Indiana Univ., Bloomington, IN (United States). Dept. of Chem. and Phys. and IUCF; Dorsett, J. [Department of Chemistry Technical Services, Indiana University, Bloomington, IN 47405 (United States); Poehlman, J. [Department of Chemistry Technical Services, Indiana University, Bloomington, IN 47405 (United States); Madden, N. [Consultant, Livermore, CA (United States); Ottarson, J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States)

    1995-06-15

    A low threshold charged particle detector array for the study of fragmentation processes in light-ion-induced reactions has been constructed and successfully implemented at the IUCF and Saturne II accelerators. The array consists of 162-triple-element detector telescopes mounted in a spherical geometry and covering 74% of 4{pi} in solid angle. Telescope elements are composed of (1) an axial-field gas ionization chamber operated with C{sub 3}F{sub 8} gas; (2) a 0.5 mm thick passivated silicon detector, and (3) a 2.8 cm thick CsI(Tl) scintillation crystal with photodiode readout. Discrete element identification is obtained for ejectiles up to Z similar 16 over the dynamic range 0.7{<=}E/A{<=}95 MeV/nucleon. Isotopes are also distinguished for H, He, Li and Be ejectiles with 8< or {approx}E/A< or {approx}95 MeV. Custom-designed electronics are employed for bias supplies and linear signal processing. Data are acquired via a CAMAC/VME/Ethernet system. (orig.).

  7. 4$\\pi$ detector for study of Zeno effect using 220Rn -> 216Po alpha->alpha correlated chains

    CERN Document Server

    Nadderd, L; Subotic, K; Polyakov, A N; Lobanov, Y V; Rykhlyuk, A V

    2015-01-01

    First test of the 4pi detector for study of exponential law of radioactive decay and possibility of observation of Zeno effect [1-3], measuring the mean life of 216Po is presented. This detector consists of two surface-barrier n-Si(Au) detectors placed in the close contact ( 4T1/2. Both, the data acquisition system and the vacuum chamber design are presented in brief.

  8. The Crystal Barrel: Meson Spectroscopy at LEAR with a 4$\\pi$ Detector

    CERN Multimedia

    2002-01-01

    % PS197 \\\\ \\\\The Crystal Barrel is a 4$\\pi$ spectrometer designed to provide complete and precise information on practically every final state produced in $\\bar{p} p $ and $\\bar{p}d $ annihilations at low energy and to collect high statistics data samples. Selective triggers can be applied when necessary. \\\\ \\\\The physics goal is to identify all light mesons in the mass range from 0.14 to 2.3~GeV/c$^{2}$, to determine their quantum numbers and decay properties and to study the annihilation dynamics. The main interest is to find the glueball and hybrid degrees of freedom predicted in the framework of Quantum Chromodynamics. \\\\ \\\\\

  9. Use of fragmentation beams at LNS with CHIMERA detector

    OpenAIRE

    Gianí R.; Francalanza L.; DeFilippo E.; Chatterjiee M.B.; Buscemi M.; Berceanu I.; Auditore L.; Anzalone A.; Amorini F.; Agodi C.; Acosta L.; Cardella G.; Grassi L.; La Guidara E.; Lanzalone G.

    2012-01-01

    The recent intensity upgrade of the LNS fragmentation beam is discussed. The available beams, the tagging procedures and details on the beam quality are reported. The experimental program started with the CHIMERA detector using such beams is also discussed with preliminary results and future perspectives.

  10. Use of fragmentation beams at LNS with CHIMERA detector

    Directory of Open Access Journals (Sweden)

    Gianí R.

    2012-07-01

    Full Text Available The recent intensity upgrade of the LNS fragmentation beam is discussed. The available beams, the tagging procedures and details on the beam quality are reported. The experimental program started with the CHIMERA detector using such beams is also discussed with preliminary results and future perspectives.

  11. Nuclear Fragmentation Induced by Relativistic Projectiles Studied in the 4$\\pi$ Configuration of Plastic Track Detectors

    CERN Multimedia

    2002-01-01

    % EMU19 \\\\ \\\\ The collisions of heavy ions at relativistic energies have been studied to explore a number of questions related with hot and dense nuclear matter in order to extend our knowledge of nuclear equation-of-state. There are other aspects of these interactions which are studied to expound the process of projectile and/or target disintegrations. The disintegrations in question could be simply binary fissions or more complex processes leading to spallation or complete fragmentation. These important aspects of nuclear reactions are prone to investigations with nuclear track detectors. \\\\ \\\\One of the comparatively new track detector materials, CR-39, is sensitive enough to record particles of Z~$\\geq$~6 with almost 100\\% efficiency up to highly relativistic energies. The wide angle acceptance and exclusive measurements possible with plastic track detectors offer an opportunity to use them in a variety of situations in which high energy charged fragments are produced. The off-line nature of measuring tra...

  12. Using CHIMERA detector at LNS for gamma-particle coincidences

    Directory of Open Access Journals (Sweden)

    Cardella G.

    2016-01-01

    Full Text Available We have recently evaluated the quality of γ-ray angular distributions that can be extracted in particle-gamma coincidence measurements using the CHIMERA detector at LNS. γ-rays have been detected using the CsI(Tl detectors of the spherical part of the CHIMERA array. Very clean γ-rays angular distributions were extracted in reactions induced by different stable beams impinging on 12C thin targets. The results evidenced an effect of projectile spin flip on the γ-rays angular distributions. γ-particle coincidence measurements were also performed in reactions induced by neutron rich exotic beams produced through in-flight fragmentation at LNS. In recent experiments also the Farcos array was used to improve energy and angular resolution measurements of the detected charged particles. Results obtained with both stable and radioactive beams are reported.

  13. Using CHIMERA detector at LNS for gamma-particle coincidences

    Science.gov (United States)

    Cardella, G.; Acosta, L.; Auditore, L.; Chatterjiee, M. B.; Castoldi, A.; De Filippo, E.; Dell'Aquila, D.; De Luca, S.; Gnoffo, B.; Guazzoni, C.; Francalanza, L.; Lanzalone, G.; Lombardo, I.; Martorana, N.; Norella, S.; Pagano, A.; Pagano, E. V.; Papa, M.; Pirrone, S.; Politi, G.; Quattrocchi, L.; Rizzo, F.; Russotto, P.; Trifirò, A.; Trimarchi, M.; Verde, G.; Vigilante, M.

    2016-05-01

    We have recently evaluated the quality of γ-ray angular distributions that can be extracted in particle-gamma coincidence measurements using the CHIMERA detector at LNS. γ-rays have been detected using the CsI(Tl) detectors of the spherical part of the CHIMERA array. Very clean γ-rays angular distributions were extracted in reactions induced by different stable beams impinging on 12C thin targets. The results evidenced an effect of projectile spin flip on the γ-rays angular distributions. γ-particle coincidence measurements were also performed in reactions induced by neutron rich exotic beams produced through in-flight fragmentation at LNS. In recent experiments also the Farcos array was used to improve energy and angular resolution measurements of the detected charged particles. Results obtained with both stable and radioactive beams are reported.

  14. $\\bar{p}$-Induced Fission Studies with Plastic Track Detectors Using 4$\\pi$-Geometry

    CERN Multimedia

    2002-01-01

    % EMU20 \\\\ \\\\ The annihilation of a stopped antiproton on the surface of a target nucleus produces on the average five pions with a mean energy of 230~MeV. The high excitation of the nuclei with low angular momentum transfer can also be achieved by direct pion-nucleus interactions. The fission probabilities of highly excited nuclei can be explained on the basis of high energy limit of statistical theory. Previously the binary fission and higher multiplicity break-up of various nuclei caused by the absorption of pions has been studied by our group. The mechanism of nuclear excitation may still be the same when an antiproton annihilates in a nucleus and produces pions. It would be interesting to see whether the $\\bar{p}$ annihilation produces high enough excitation energies for nuclear phase-transition to take place. If so, then the fragmentation would overwhelm binary and ternary fission process. \\\\ \\\\The use of a highly sensitive plastic detector, CR-39, was made by our group in a number of studies involving ...

  15. Heavy Ion Physics at Low, Intermediate and Relativistic Energies Using 4PI Detectors - Proceedings of the International Research Workshop

    Science.gov (United States)

    Petrovici, M.; Sandulescu, A.; Pelte, D.; Stöcker, H.; Randrup, J.

    1997-10-01

    The Table of Contents for the full book PDF is as follows: * Preface * Neutronless Fragmentation in the Spontaneous Fission of 252Cf * Cnoidal Waves as Solutions of the Nonlinear Liquid Drop Model * Thermalization Time-Scale of the Giant Quadrupole Resonance * Application of Lindblad Theory to Problems of Nuclear Dissipation * Microcanonical Approach for Investigating the Decay of Highly Excited Nuclei * Particle Stable Semiclassical Simulation of a Nucleus for High-Energy Heavy-Ion Collisions * Decay Study of Hot Nuclei Below the Multifragmentation Threshold with the FOBOS Detector at Dubna * 4π Experiments with MEDEA * Thermodynamical Properties and Deexcitation of Sources Involved in Collisions Between Light Nuclei Around 100 AMeV Incident Energy * Dynamics of Nucleus-Nucleus Collisions Up to 100 MeV/u and the Caloric Curve * Multifragmentation and the Search for the Liquid-Gas Phase Transition in Nuclear Matter * Multifragmentation Studies at Intermediate Energies with the New 4π Detector CHIMERA * Nuclear Matter Flow Studies at GANIL using NAUTILUS * Transverse and Radial Flow in Intermediate Energy Nucleus-Nucleus Collisions * Fragment Flow in Au+Au Collisions * Limits of Energy Equilibration in Central Au on Au Collisions in the Projectile Energy Range from 150 AMeV to 1050 AMeV * System Dependence of Event Shapes, Radial Flow and Fragment Production in Central Collision of Ni+Ni, Xe+CsI and Au+Au at 250 AMeV * Out-of-Plane Emission of Nuclear Matter in Heavy Ion Collisions Between 150 and 800 AMeV * Flow and Spectra for Light Fragments from Au+Au Collisions in the EOS TPC * Transition from In-Plane to Out-of-Plane Emission in Heavy Ion Collisions * Collective Expansion of Hot and Compressed Nuclear Matter * Collective Flow in Central Au+Au Collisions at E~1 AGeV * Proton-Proton Correlations in Central Collisions of Ni+Ni at 1.93 AGeV and the Space-Time Extent of the Emission Source * Compression and Expansion in Central Collisions * Pion Production at SIS

  16. CHIMERA: a 4π detector array for heavy ion reaction studies at intermediate energy. Survey and status of the project

    International Nuclear Information System (INIS)

    CHIMERA is a multi-element detector array made of 1192 Si-CsI telescopes covering the 94% of the whole solid angle that is planned to fully operate in 1998 by using the Super conducing Cyclotron beams at the LNS of Catania. Besides the usual charge identification, due to simultaneous TOF measurements, CHIMERA allows a mass identification. The high granularity reduces drastically the multiple firing and make it possible to perform an event by event analysis as required in multifragmentation process studies. The authors will discuss some results of simulations concerning the problem of the complete event reconstruction, in connection with the specific performances of the detector

  17. Fragmentation studies with the CHIMERA detector at LNS in Catania: recent progress

    Science.gov (United States)

    Pagano, A.; Alderighi, M.; Amorini, F.; Anzalone, A.; Arena, L.; Auditore, L.; Baran, V.; Bartolucci, M.; Berceanu, I.; Blicharska, J.; Brzychczyk, J.; Bonasera, A.; Borderie, B.; Bougault, R.; Bruno, M.; Cardella, G.; Cavallaro, S.; Chatterjee, M. B.; Chbihi, A.; Cibor, J.; Colonna, M.; D'Agostino, M.; Dayras, R.; De Filippo, E.; Di Toro, M.; Gawlikowicz, W.; Geraci, E.; Giustolisi, F.; Grzeszczuk, A.; Guazzoni, P.; Guinet, D.; Iacono-Manno, M.; Kowalski, S.; La Guidara, E.; Lanzano, G.; Lanzalone, G.; Le Neindre, N.; Li, S.; Lo Nigro, S.; Maiolino, C.; Majka, Z.; Manfredi, G.; Paduszynski, T.; Papa, M.; Petrovici, M.; Piasecki, E.; Pirrone, S.; Planeta, R.; Politi, G.; Pop, A.; Porto, F.; Rivet, M. F.; Rosato, E.; Rizzo, F.; Russo, S.; Russotto, P.; Sassi, M.; Sechi, G.; Simion, V.; Siwek-Wilczynska, K.; Skwira, I.; Sperduto, M. L.; Steckmeyer, J. C.; Swiderski, L.; Trifiro`, A.; Trimarchi, M.; Vannini, G.; Vigilante, M.; Wieleczko, J. P.; Wilczynski, J.; Wu, H.; Xiao, Z.; Zetta, L.; Zipper, W.

    2004-04-01

    The new detector CHIMERA, in its final 4π configuration, has been installed at Laboratori Nazionali del Sud (LNS) in Catania in January 2003. Beams of different energies ranging from protons to Au ions were delivered by the Tandem and the Super Conducting Cyclotron for nuclear reaction studies, in agreement with the approval of the Scientific Advisory Committee of LNS. Recent experimental results confirm very low energy thresholds of the trigger (below 0.5 MeV/nucleon), ensured within a wide dynamical range. Good characteristics of identification of light charged particles and heavy fragments have been obtained by using three detection techniques: Δ E-E, Δ E-time of flight, and the Pulse-Shape discrimination method. We present results of recent analysis concerning the production of intermediate mass fragments (IMF) in semi-peripheral collisions. Our results combined with theoretical Boltzmann-Nordheim-Vlasov simulations clearly demonstrate the presence of very fast processes of IMF production in the overlapping region of the target and projectile nuclei during re-separation, i.e. in the time scale comparable with the collision time. Evidence for slower, sequential-like production of IMF's is also shown.

  18. A 4$\\pi$ Solid Angle Detector for the SPS used as a Proton-Antiproton Collider at a Centre of Mass Energy of 540 GeV

    CERN Multimedia

    2002-01-01

    In the first phase of operation of the UA1 experiment, 700 $ nb ^- ^{1} $ of integrated luminosity were accumulated at the Sp$\\bar{p}$S collider up to the end of 1985. Published results include first observation and measurements of W and Z bosons, significant limits on the top quark, heavy lepton and supersymmetric particle masses, observation of $ B \\bar{B} $ mixing, studies of b~quark production and tests of QCD using jet, intermediate boson and photon production.\\\\ \\\\ For the second phase of operation the following items were upgraded for the high luminosity 1988 and 1989 collider runs: the muon detection system was improved by extra iron shielding, partly magnetised and instrumented with Iarocci tubes; the data acquisition system was redesigned using VME to prov speed and second level trigger capacity followed by a farm of 318E emulators for on-line event reconstruction and selection; the central detector was equipped with a laser calibration system. A total of 5 $ pb ^- ^{1} $ of mainly muon-triggered da...

  19. A VMEbus interface for multi-detector trigger and control system

    CERN Document Server

    Gong Pei Rong; Litroco, P

    2002-01-01

    MUSE (MUltiplicity SElector) is the trigger and control system of CHIMERA, a 4 pi charged particles detector. Initialization of MUSE can be performed via VMEbus. The author describes the design of VMEbus interface and functional module in MUSE, and briefs an application of MUSE

  20. Controlling chimeras

    OpenAIRE

    Bick, Christian; Martens, Erik Andreas

    2015-01-01

    Coupled phase oscillators model a variety of dynamical phenomena in nature and technological applications. Non-local coupling gives rise to chimera states which are characterized by a distinct part of phase-synchronized oscillators while the remaining ones move incoherently. Here, we apply the idea of control to chimera states: using gradient dynamics to exploit drift of a chimera, it will attain any desired target position. Through control, chimera states become functionally relevant; for ex...

  1. Controlling chimeras

    Science.gov (United States)

    Bick, Christian; Martens, Erik A.

    2015-03-01

    Coupled phase oscillators model a variety of dynamical phenomena in nature and technological applications. Non-local coupling gives rise to chimera states which are characterized by a distinct part of phase-synchronized oscillators while the remaining ones move incoherently. Here, we apply the idea of control to chimera states: using gradient dynamics to exploit drift of a chimera, it will attain any desired target position. Through control, chimera states become functionally relevant; for example, the controlled position of localized synchrony may encode information and perform computations. Since functional aspects are crucial in (neuro-)biology and technology, the localized synchronization of a chimera state becomes accessible to develop novel applications. Based on gradient dynamics, our control strategy applies to any suitable observable and can be generalized to arbitrary dimensions. Thus, the applicability of chimera control goes beyond chimera states in non-locally coupled systems.

  2. 4. pi beta. -. gamma. coincidence system with minimally broadened pulses

    Energy Technology Data Exchange (ETDEWEB)

    Gehrke, R.J.; Johnson, L.O. (Idaho National Engineering Lab., Idaho Falls (USA))

    1982-12-15

    The performance characteristics of a new type 4..pi.. ..beta..-..gamma.. coincidence system have been measured. In contrast with the conventional 4..pi.. ..beta..-..gamma.. circuitry, which is based on a fixed pulse width (approx.= 2 ..mu..s) and a non-extendable dead time, the pulse processing circuitry in this new system is based on a minimally broadened pulse (i.e., as narrow as 0.25 ..mu..s). In this system each pulse has a different pulse width, so that the dead times for the ..beta..- and ..gamma..-ray detectors are determined by summing the measured dead time attributed by each pulse in each channel. The ..beta..-..gamma.. coincidences are defined with an overlap coincidence circuit. This system is shown to be much less sensitive to mismatch in the coincidence timing than is the conventional system. In spite of the narrower pulse widths, no spurious ..beta.. pulses are observed when the 4..pi.. proportional counter is operated near the center of its plateau. Disintegration rates were measured for calibrated sources with strength up to approx.= 10/sup 6/ Bq. These data indicate that with this new system the disintegration rates of very intense sources (approx.= 10/sup 6/ Bq) and moderately intense sources (< 10/sup 5/ Bq) can be determined with accuracies of approx.= 4% and <= 0.1%, respectively.

  3. Particle gamma correlations in 12C measured with the CsI(Tl) based detector array CHIMERA

    Science.gov (United States)

    Cardella, G.; Acosta, L.; Amorini, F.; Auditore, L.; Berceanu, I.; Castoldi, A.; De Filippo, E.; Dell`Aquila, D.; Francalanza, L.; Gnoffo, B.; Guazzoni, C.; Lanzalone, G.; Lombardo, I.; Minniti, T.; Morgana, E.; Norella, S.; Pagano, A.; Pagano, E. V.; Papa, M.; Pirrone, S.; Politi, G.; Pop, A.; Quattrocchi, L.; Rizzo, F.; Rosato, E.; Russotto, P.; Trifirò, A.; Trimarchi, M.; Verde, G.; Vigilante, M.

    2015-11-01

    The gamma decay of the first excited 4.44 MeV 2+level of 12C, populated by inelastic scattering of proton and 16O beams at various energies was studied in order to test γ-ray detection efficiency and the quality of angular distribution information given by the CsI(Tl) detectors of the 4π CHIMERA array. The γ-decay was measured in coincidence with ejectile scattered particles in an approximately 4π geometry allowing to extract the angular distribution in the reference frame of recoiling 12C target. The typical sin2 (2θ) behavior of angular distribution was observed in the case of 16O beam. Besides that, for the proton beam, in order to explain the observed distribution, the addition of an incoherent flat contribution was required. This latter is the effect of proton spin flip events allowing the population of M=±1 magnetic substates, that is not possible in reactions induced by 16O beam. A comparison with previously collected data, obtained measuring only in and out of plane proton-γ-ray coincidences, confirms the good quality of the angular distribution information given by the apparatus. Possible applications with radioactive beams are outlined.

  4. Particle gamma correlations in {sup 12}C measured with the CsI(Tl) based detector array CHIMERA

    Energy Technology Data Exchange (ETDEWEB)

    Cardella, G., E-mail: cardella@ct.infn.it [INFN - Sezione di Catania, Via S. Sofia, 95123 Catania (Italy); Acosta, L. [INFN - Sezione di Catania, Via S. Sofia, 95123 Catania (Italy); Amorini, F. [INFN - Laboratori Nazionali del Sud, Via S. Sofia, Catania (Italy); Auditore, L. [INFN Gruppo collegato di Messina and Dip. di Fisica e Scienze della Terra, Università di Messina (Italy); Berceanu, I. [Institute for Physics and Nuclear Engineering, Bucharest (Romania); Castoldi, A. [INFN Sezione di Milano e Politecnico Milano (Italy); De Filippo, E. [INFN - Sezione di Catania, Via S. Sofia, 95123 Catania (Italy); Dell' Aquila, D. [Dipartimento di scienze Fisiche, Università Federico II and INFN Sezione di Napoli (Italy); Francalanza, L. [INFN - Laboratori Nazionali del Sud, Via S. Sofia, Catania (Italy); Dip. di Fisica e Astronomia, Università di Catania, Via S. Sofia, Catania (Italy); Gnoffo, B. [INFN - Sezione di Catania, Via S. Sofia, 95123 Catania (Italy); Guazzoni, C. [INFN Sezione di Milano e Politecnico Milano (Italy); Lanzalone, G. [INFN - Laboratori Nazionali del Sud, Via S. Sofia, Catania (Italy); Facoltà di Ingegneria e Architettura, Università Kore, Enna (Italy); Lombardo, I. [Dipartimento di scienze Fisiche, Università Federico II and INFN Sezione di Napoli (Italy); Minniti, T.; Morgana, E.; Norella, S. [INFN Gruppo collegato di Messina and Dip. di Fisica e Scienze della Terra, Università di Messina (Italy); Pagano, A. [INFN - Sezione di Catania, Via S. Sofia, 95123 Catania (Italy); Pagano, E.V. [INFN - Laboratori Nazionali del Sud, Via S. Sofia, Catania (Italy); Dip. di Fisica e Astronomia, Università di Catania, Via S. Sofia, Catania (Italy); Papa, M.; Pirrone, S. [INFN - Sezione di Catania, Via S. Sofia, 95123 Catania (Italy); and others

    2015-11-01

    The gamma decay of the first excited 4.44 MeV 2+level of {sup 12}C, populated by inelastic scattering of proton and {sup 16}O beams at various energies was studied in order to test γ-ray detection efficiency and the quality of angular distribution information given by the CsI(Tl) detectors of the 4π CHIMERA array. The γ-decay was measured in coincidence with ejectile scattered particles in an approximately 4π geometry allowing to extract the angular distribution in the reference frame of recoiling {sup 12}C target. The typical sin{sup 2} (2θ) behavior of angular distribution was observed in the case of {sup 16}O beam. Besides that, for the proton beam, in order to explain the observed distribution, the addition of an incoherent flat contribution was required. This latter is the effect of proton spin flip events allowing the population of M=±1 magnetic substates, that is not possible in reactions induced by {sup 16}O beam. A comparison with previously collected data, obtained measuring only in and out of plane proton-γ-ray coincidences, confirms the good quality of the angular distribution information given by the apparatus. Possible applications with radioactive beams are outlined.

  5. 4. pi. physics with the plastic ball

    Energy Technology Data Exchange (ETDEWEB)

    Gutbrod, H.H.; Loehner, H.; Poskanzer, A.M.; Renner, T.; Riedesel, H.; Ritter, H.G.; Warwick, A.; Weik, F.; Wieman, H.

    1982-10-01

    4 ..pi.. data taken with the Plastic Ball show that cluster production in relativistic nuclear collisions depends on both the size of the participant volume and the finite size of the cluster. The measurement of the degree of thermalization and the search for collective flow will permit the study of the applicability of macroscopic concepts such as temperature and density.

  6. INDRA, a 4{pi} charged product detection array at GANIL

    Energy Technology Data Exchange (ETDEWEB)

    Pouthas, J.; Plagnol, E.; Saint-Laurent, F.; Auger, G.; Benkirane, A.; Benlliure, J.; Bourgault, P.; Chbihi, A.; Clerc, T.; Copinet, N.; Huguet, Y.; Le Guay, M.; Martina, L.; Olivier, L.; Piquet, B.; Raine, B.; Ropert, J.; Spitaels, C.; Tripon, M.; Vallerand, P.; Wieleczko, J.P.; Wittwer, G. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Borderie, B.; Rivet, M.F.; Bacri, C.O.; Barbey, S.; Barbier, A.; Box, P.; Bzyl, R.; Charlet, D.; Engrand, M.; Lelong, P.; Pierre, S.; Richard, A.; Stab, L.; Sznajderman, D.; Tassan-Got, L.; Volkov, P. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Dayras, R.; Berthier, B.; Bougamont, E.; Cahan, B.; Cassagnou, Y.; Charvet, J.L.; Legrain, R.; Mazur, C.; Passerieux, J.P.; Pollacco, E.C.; Volant, C. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee; Steckmeyer, J.C.; Cussol, D.; Gautier, J.M.; Laville, J.L.; Le Botlan, P.; Leconte, A.; Mosrin, P.; Tillier, J. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; Jouniaux, O.; Plaige, E. [Paris-11 Univ., 91 - Orsay (France). Lab. de l`Accelerateur Lineaire

    1994-12-31

    INDRA, a new and innovative highly segmented detector for light charged particles and fragments is described. It covers geometrically 90% of the 4{pi} solid angle and has very low detection thresholds. The detector, operated under vacuum, is axially symmetric and segmented in 336 independent cells allowing efficient detection of high multiplicity events. Nucleus identification down to very low energy threshold ({approx_equal} 1 A.MeV) is achieved by using ionization chambers operated with low pressure C{sub 3}F{sub 8} gas. Residual energies are measured by a combination of silicon (300 {mu}m thick) and cesium iodide (5 to 14 cm in length) detectors. Very forward angles are covered by fast counting phoswich scintillators (NE102/NE115). Charge resolution up to Z=50 is achieved on a large energy dynamic range (5000 to 1 for silicon detectors). Isotopic separation is obtained up to Z=3. The treatment of the signals is performed through specifically designed and highly integrated modules, most of which are in the new VXIbus standard. Full remote control of parameter settings, including visualization of signals, is thus allowed. The detector is continuously monitored with a laser source and electronic pulsers and is found stable over several days. Energy calibration procedures, making use of specific detectors and the ability of the GANIL accelerator to deliver secondary beams, have been developed. First experiments were performed in the spring of 1993. (authors). 49 refs., 25 figs., 3 tabs.

  7. The 4 Pi Sky Transient Alerts Hub

    CERN Document Server

    Staley, Tim D

    2016-01-01

    We introduce the 4 Pi Sky 'hub', a collection of open data-services and underlying software packages built for rapid, fully automated reporting and response to astronomical transient alerts. These packages build on the mature 'VOEvent' standardized message-format, and aim to provide a decentralized and open infrastructure for handling transient alerts. In particular we draw attention to the initial release of voeventdb, an archive and remote-query service that allows astronomers to make historical queries about transient alerts. By employing spatial filters and web-of-citation lookups, voeventdb enables cross-matching of transient alerts to bring together data from multiple sources, as well as providing a point of reference when planning new follow-up campaigns. We also highlight the recent addition of optical-transient feeds from the ASASSN and GAIA projects to our VOEvent distribution stream. Both the source-code and deployment-scripts which implement these services are freely available and permissively lic...

  8. Experimental effects of dynamics and thermodynamics in nuclear reactions on the symmetry energy as seen by the CHIMERA 4 π detector

    Energy Technology Data Exchange (ETDEWEB)

    De Filippo, E.; Pagano, A. [INFN, Catania (Italy)

    2014-02-15

    Heavy-ion collisions have been widely used in the last decade to constrain the parameterizations of the symmetry energy term of the nuclear equation of state (EOS) for asymmetric nuclear matter as a function of baryonic density. In the Fermi energy domain one is faced with variations of the density within a narrow range of values around the saturation density ρ{sub 0}=0.16 fm{sup -3} down towards sub-saturation densities. The experimental observables which are sensitive to the symmetry energy are constructed starting from the detected light particles, clusters and heavy fragments that, in heavy-ion collisions, are generally produced by different emission mechanisms at different stages and time scales of the reaction. In this review the effects of dynamics and thermodynamics on the symmetry energy in nuclear reactions are discussed and characterized using an overview of the data taken so far with the CHIMERA multi detector array. (orig.)

  9. Application of PGNAA for bulk coal samples in a 4pi geometry

    Energy Technology Data Exchange (ETDEWEB)

    Borsaru, M.; Jecny, Z. [CSIRO, Kenmore, Qld. (Australia). Exploration and Mining

    2001-07-01

    The paper describes a 4 pi geometry bulk coal analyser using the Prompt gamma neutron activation analysis (PGNAA) technique that was tested in the laboratory. The volume of the bulk samples was 270 litres. A 1.5 {mu}g Cf-252 neutron source and a 75 mm x 35 mm diameter EGO detector were used for the measurements. The ash, Fe, Si and Al content of coal were determined with good accuracy.

  10. Application of PGNAA for bulk coal samples in a 4{pi} geometry

    Energy Technology Data Exchange (ETDEWEB)

    Borsaru, M.; Jecny, Z

    2001-03-01

    A 4{pi} geometry bulk coal analyser using the Prompt gamma neutron activation analysis (PGNAA) technique was tested in the laboratory. The volume of the bulk samples was 270 litres. A 1.5 {mu}g {sup 252}Cf neutron source and a 75 mm x 35 mm dia BGO detector were used for the measurements. The ash, Fe, Si and Al content of coal were determined with good accuracy.

  11. Application of PGNAA for bulk coal samples in a 4pi geometry.

    Science.gov (United States)

    Borsaru, M; Jecny, Z

    2001-03-01

    A 4pi geometry bulk coal analyser using the Prompt gamma neutron activation analysis (PGNAA) technique was tested in the laboratory. The volume of the bulk samples was 270 litres. A 1.5 microg 252Cf neutron source and a 75 mm x 35 mm dia BGO detector were used for the measurements. The ash, Fe, Si and Al content of coal were determined with good accuracy. PMID:11214889

  12. Recent results of CHIMERA activity

    Directory of Open Access Journals (Sweden)

    Pagano A.

    2012-07-01

    Full Text Available The experimental activity of CHIMERA in recent years has been characterized by a steady progress in the detection technique and data analysis. Since 2008 the detector system benefits of new implementations: a new reaction chamber, a new charged particle identification in silicon detector made by an extended pulse shape method and an efficient system for the identification of exotic beams produced by projectile-like fragmentation (In-flight method. These implementations appear to be promising tools in view of further exclusive experiments in the field of isospin physics. The coupling of CHIMERA with other equipments (such as interferometers and highly segmented arrays, magnetic elements, neutron detectors, etc. is also envisaged in order to extend the studies of the reaction mechanism in heavy ion physics.

  13. Optimization of a coincidence system using plastic scintillators in 4pi geometry.

    Science.gov (United States)

    Dias, M S; Piuvezam-Filho, H; Koskinas, M F

    2008-01-01

    Improvements recently developed at the Nuclear Metrology Laboratory of IPEN-CNEN/SP in São Paulo were performed in order to increase the detector efficiency of a 4pibeta-gamma coincidence primary system using plastic scintillators in 4pi geometry. Measurements were undertaken and compared to the original system and Monte Carlo simulations of the extrapolation curves were calculated for this new system and compared to experimental results. For this purpose, the code Penelope was applied for calculating response functions for each detector and the code Esquema, developed at LMN, was used for simulating the decay scheme processes.

  14. Characterisation of fragments emission by azimuthal correlations using 4{pi} AMPHORA detector: study of {sup 32}S + {sup 58}Ni and {sup nat}Ag at 38 MeV per nucleon; Caracterisation de l`emission de fragments par correlations azimutales avec le detecteur 4{pi} AMPHORA: etude des systemes {sup 32}S+{sup 58}Ni et {sup nat}Ag a 38 MeV par nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Benchekroun, D.

    1994-05-01

    The first part of this work reports on designing and testing a detector made of a gas proportional counter coupled to a CsI(TI) crystal. It is shown that a good identification of fragments of charge ranging from 3 to 20 is achieved. The energy threshold is lower than in the case of a conventional plastic - CsI(TI) phoswich detector. The second part is devoted to the study of complex fragment production in the {sup 32}S + {sup nat}Ag and {sup 32}S + {sup 58}Ni reactions using the multidetector array AMPHORA. The total multiplicity of charged particles has been used as a criterion of centrally of the collision. The evaluation of the characteristics of fragment emission has thus been studied from peripheral to central collisions. In the case of the most violet collisions the data infer that a rotating hot source has been formed (excitation energy of the order of 500 MeV). It is demonstrated that this sources de-excites through emission of a long chain of fragments and particles. The analysis of the azimuthal correlations of fragments with the evaporation code MODGAN confirmed the hypothesis of such a source. That hot source should rotate with an angular momentum up to 120 h and the emission times would be of the order of 10{sup -21} s. (author). 80 refs.

  15. Detection of polarization from the E^4\\Pi-A^4\\Pi system of FeH in sunspot spectra

    CERN Document Server

    Ramos, A A; Collados, M

    2004-01-01

    Here we report the first detection of polarization signals induced by the Zeeman effect in spectral lines of the E^4\\Pi-A^4\\Pi system of FeH located around 1.6 $\\mu$m. Motivated by the tentative detection of this band in the intensity spectrum of late-type dwarfs, we have investigated the full Stokes sunspot spectrum finding circular and linear polarization signatures that we associate with the FeH lines of the E^4\\Pi-A^4\\Pi band system. We investigate the Zeeman effect in these molecular transitions pointing out that in Hund's case (a) coupling the effective Land\\'e factors are never negative. For this reason, the fact that our spectropolarimetric observations indicate that the Land\\'e factors of pairs of FeH lines have opposite signs, prompt us to conclude that the E^4\\Pi-A^4\\Pi system must be in intermediate angular momentum coupling between Hund's cases (a) and (b). We emphasize that theoretical and/or laboratory investigations of this molecular system are urgently needed for exploiting its promising diag...

  16. Absolute measurement of {beta} emitters with a 4 {pi} counter; Mesure absolue des emetteurs {beta} au compteur 4 {pi}

    Energy Technology Data Exchange (ETDEWEB)

    Le Gallic, Y. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-06-15

    The object of this work is to investigate the conditions under which the activity of {beta}-emitting radionuclides may be measured with a maximum of precision, and as a result to study the relevant corrections. The various problems relating to activity measurements with a 4 {pi} counter have been examined successively: - comparison of 4 {pi}, GM and proportional counters; - study of the preparation of sources; - corrections on the counting of sources; - self-absorption; - correction for absorption. The precision obtained on these measurements varies from 1.2 to 3 per cent, with the result that the 4 {pi} counter can be considered a very satisfactory calibration instrument. (author) [French] Le but de ce travail est de rechercher les conditions permettant d'obtenir avec le maximum de precision, la mesure de l'activite des radionuclides se desintegrant par emission et par consequent d'etudier les corrections qui s'y rapportent. Nous avons examine successivement les differents problemes se rapportant aux mesures d'activite au compteur 4 {pi}: - Comparaison des compteurs 4 {pi}, GM et proportionnel; - etude de la preparation des sources; - corrections sur la numeration des sources; - auto-absorption; - correction d'absorption. La precision obtenue dans ces mesures, variant de 1,2 a 3 pour cent, on peut donc considerer le compteur 4 {pi} comme un instrument d'etalonnage tres satisfaisant. (auteur)

  17. Self-propelled Chimeras

    OpenAIRE

    Kruk, Nikita; Maistrenko, Yuri; Wenzel, Nicolas; Koeppl, Heinz

    2015-01-01

    We report the appearance of chimera states in a minimal extension of the classical Vicsek model for collective motion of self-propelled particle systems. Inspired by earlier works on chimera states in the Kuramoto model, we introduce a phase lag parameter in the particle alignment dynamics. Compared to the oscillatory networks with fixed site positions, the self-propelled particle systems can give rise to distinct forms of chimeras resembling moving flocks through an incoherent surrounding, f...

  18. Amplitude mediated chimera states

    OpenAIRE

    Sethia, Gautam C.; Sen, Abhijit; Johnston, George L.

    2013-01-01

    We investigate the possibility of obtaining chimera state solutions of the non-local Complex Ginzburg-Landau Equation (NLCGLE) in the strong coupling limit when it is important to retain amplitude variations. Our numerical studies reveal the existence of a variety of amplitude mediated chimera states (including stationary and non-stationary two cluster chimera states), that display intermittent emergence and decay of amplitude dips in their phase incoherent regions. The existence regions of t...

  19. Quantum chimera states

    Science.gov (United States)

    Viennot, David; Aubourg, Lucile

    2016-02-01

    We study a theoretical model of closed quasi-hermitian chain of spins which exhibits quantum analogues of chimera states, i.e. long life classical states for which a part of an oscillator chain presents an ordered dynamics whereas another part presents a disordered dynamics. For the quantum analogue, the chimera behaviour deals with the entanglement between the spins of the chain. We discuss the entanglement properties, quantum chaos, quantum disorder and semi-classical similarity of our quantum chimera system. The quantum chimera concept is novel and induces new perspectives concerning the entanglement of multipartite systems.

  20. Gargoyles, Grotesques, & Chimeras

    Science.gov (United States)

    Wilbert, Nancy Corrigan

    2010-01-01

    Gargoyles, grotesques, and chimeras are scary, mythical (and sometimes humorous) creatures that have functional, decorative, and spiritual significance in medieval architecture. In this article, the author describes how her ceramics students created contemporary versions of gargoyles, chimeras, and grotesque faces. (Contains 1 online resource.)

  1. VizieR Online Data Catalog: HI4PI spectra and column density maps (HI4PI team+, 2016)

    Science.gov (United States)

    Hi4PI Collaboration; Ben Bekhti, N.; Floeer, L.; Keller, R.; Kerp, J.; Lenz, D.; Winkel, B.; Bailin, J.; Calabretta, M. R.; Dedes, L.; Ford, H. A.; Gibson, B. K.; Haud, U.; Janowiecki, S.; Kalberla, P. M. W.; Lockman, F. J.; McClure-Griffiths, N. M.; Murphy, T.; Nakanishi, H.; Pisano, D. J.; Staveley-Smith, L.

    2016-09-01

    The HI4PI data release comprises 21-cm neutral atomic hydrogen data of the Milky Way (-600km/s0°; -470km/sHI4PI covers the full 4-pi sky. Spectral data is provided in three forms: (1) Standard FITS data cubes, for the full sky in both, Equatorial (J2000) and Galactic coordinates, each in four different map projections, AIT, CAR, MOL, and SFL; see world-coordinate-system, WCS, references: Greisen & Calabretta, 2002A&A...395.1061G, Calabretta & Greisen, 2002A&A...395.1077C, Greisen et al., 2006A&A...446..747G (2) Smaller FITS data cubes, each having a size of about 20x20 sq.deg. For convenience, we provide four different map projections, CAR, SFL, SIN, and TAN (again see WCS references). Note, size in longitude is 20° in absolute coordinates for CAR projection, and 20° true-angular size for SFL, SIN, and TAN projections. Again, Equatorial and Galactic coordinate systems are provided. (3) FITS binary tables containing lists of spectra sampled on a HealPIX grid (nside=1024, Galactic coordinates, Ring indexing scheme, Gorski et al., 2005ApJ...622..759G). To make handling of the data easier, the table is split into smaller files. Each of these contains spectra belonging to one of the 192 base/parent pixels of the nside=4 pixelization. For convenience, the binary tables also contain EQ2000 and Galactic coordinate positions for each individual spectrum, as well as the associated HealPIX index. Furthermore, we provide the full-sky HI column density distribution, both, in a (1) HealPIX-grid binary table (nside=1024, Galactic coordinates, Ring indexing scheme), and (2) Standard FITS 2D images in four map projections, AIT, CAR, MOL, and SFL. Various velocity intervals were applied to calculate NHI. Equatorial and Galactic coordinate systems are provided. (16 data files).

  2. Chimera states in bursting neurons

    OpenAIRE

    Bera, Bidesh K.; Ghosh, Dibakar; Lakshmanan, M.

    2015-01-01

    We study the existence of chimera states in pulse-coupled networks of bursting Hindmarsh-Rose neurons with nonlocal, global and local (nearest neighbor) couplings. Through a linear stability analysis, we discuss the behavior of stability function in the incoherent (i.e. disorder), coherent, chimera and multi-chimera states. Surprisingly, we find that chimera and multi-chimera states occur even using local nearest neighbor interaction in a network of identical bursting neurons alone. This is i...

  3. High rate 4. pi. beta. -. gamma. coincidence counting system

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, L.O.; Gehrke, R.J.

    1978-01-01

    A high count rate 4..pi.. ..beta..-..gamma.. coincidence counting system for the determination of absolute disintegration rates of short half-life radionuclides is described. With this system the dead time per pulse is minimized by not stretching any pulses beyond the width necessary to satisfy overlap coincidence requirements. The equations used to correct for the ..beta.., ..gamma.., and coincidence channel dead times and for accidental coincidences are presented but not rigorously developed. Experimental results are presented for a decaying source of /sup 56/Mn initially at 2 x 10/sup 6/ d/s and a set of /sup 60/Co sources of accurately known source strengths varying from 10/sup 3/ to 2 x 10/sup 6/ d/s. A check of the accidental coincidence equation for the case of two independent sources with varying source strengths is presented.

  4. Chimeras and human dignity.

    Science.gov (United States)

    de Melo-Martín, Inmaculada

    2008-12-01

    Discussions about whether new biomedical technologies threaten or violate human dignity are now common. Indeed, appeals to human dignity have played a central role in national and international debates about whether to allow particular kinds of biomedical investigations. The focus of this paper is on chimera research. I argue here that both those who claim that particular types of human-nonhuman chimera research threaten human dignity and those who argue that such threat does not exist fail to make their case. I first introduce some of the arguments that have been offered supporting the claim that the creation of certain sorts of chimeras threatens or violates human dignity. I next present opponents' assessments of such arguments. Finally I critically analyze both the critics' and the supporters' claims about whether chimera research threatens human dignity.

  5. Quantum chimera states

    OpenAIRE

    Viennot, David; Aubourg, Lucile

    2014-01-01

    We study a theoretical model of closed quasi-hermitian chain of spins which exhibits quantum analogues of chimera states, i.e. long life classical states for which a part of an oscillator chain presents an ordered dynamics whereas another part presents a disordered chaotic dynamics. For the quantum analogue, the chimera behavior deals with the entanglement between the spins of the chain. We discuss the entanglement properties, quantum chaos, quantum disorder and semi-classical similarity of o...

  6. Search for B0 -> rho0rho0 and Non-Resonant B0 -> 4pi Decays

    CERN Document Server

    Abe, K; Arinstein, K; Aso, T; Aulchenko, V; Aushev, T; Aziz, T; Bahinipati, S; Bakich, A M; Balagura, V; Ban, Y; Banerjee, S; Barberio, E; Bay, A; Bedny, I; Belous, K S; Bhardwaj, V; Bitenc, U; Blyth, S; Bondar, A; Bozek, A; Bracko, M; Brodzicka, J; Browder, T E; Chang, M C; Chang, P; Chao, Y; Chen, A; Chen, K F; Chen, W T; Cheon, B G; Chiang, C C; Chistov, R; Cho, I S; Choi, S K; Choi, Y; Choi, Y K; Cole, S; Dalseno, J; Danilov, M; Das, A; Dash, M; Dragic, J; Drutskoy, A; Eidelman, S; Epifanov, D; Fratina, S; Fujii, H; Fujikawa, M; Gabyshev, N; Garmash, A; Go, A; Gokhroo, G; Goldenzweig, P; Golob, B; Grosse-Perdekamp, M; Guler, H; Ha, H; Haba, J; Hara, K; Hara, T; Hasegawa, Y; Hastings, N C; Hayasaka, K; Hayashii, H; Hazumi, M; Heffernan, D; Higuchi, T; Hinz, L; Hoedlmoser, H; Hokuue, T; Horii, Y; Hoshi, Y; Hoshina, K; Hou, S; Hou, W S; Hsiung, Y B; Hyun, H J; Igarashi, Y; Iijima, T; Ikado, K; Inami, K; Ishikawa, A; Ishino, H; Itoh, R; Iwabuchi, M; Iwasaki, M; Iwasaki, Y; Jacoby, C; Joshi, N J; Kaga, M; Kah, D H; Kaji, H; Kajiwara, S; Kakuno, H; Kang, J H; Kapusta, P; Kataoka, S U; Katayama, N; Kawai, H; Kawasaki, T; Kibayashi, A; Kichimi, H; Kim, H J; Kim, H O; Kim, J H; Kim, S K; Kim, Y J; Kinoshita, K; Korpar, S; Kozakai, Y; Krizan, P; Krokovny, P; Kumar, R; Kurihara, E; Kusaka, A; Kuzmin, A; Kwon, Y J; Lange, J S; Leder, G; Lee, J; Lee, J S; Lee, M J; Lee, S E; Lesiak, T; Li, J; Limosani, A; Lin, S W; Liu, Y; Liventsev, D; MacNaughton, J; Majumder, G; Mandl, F; Marlow, D; Matsumura, T; Matyja, A; McOnie, S; Medvedeva, T; Mikami, Y; Mitaroff, W A; Miyabayashi, K; Miyake, H; Miyata, H; Miyazaki, Y; Mizuk, R; Moloney, G R; Mori, T; Müller, J; Murakami, A; Nagamine, T; Nagasaka, Y; Nakahama, Y; Nakamura, I; Nakano, E; Nakao, M; Nakayama, H; Nakazawa, H; Natkaniec, Z; Neichi, K; Nishida, S; Nishimura, K; Nishio, Y; Nishizawa, I; Nitoh, O; Noguchi, S; Nozaki, T; Ogawa, A; Ogawa, S; Ohshima, T; Okuno, S; Olsen, S L; Ono, S; Ostrowicz, W; Ozaki, H; Pakhlov, P; Pakhlova, G; Palka, H; Park, C W; Park, H; Park, K S; Parslow, N; Peak, L S; Pernicka, M; Pestotnik, R; Peters, M; Piilonen, L E; Poluektov, A; Rorie, J; Rózanska, M; Sahoo, H; Sakai, Y; Sakamoto, H; Sakaue, H; Sarangi, T R; Satoyama, N; Sayeed, K; Schietinger, T; Schneider, O; Schonmeier, P; Schümann, J; Schwanda, C; Schwartz, A J; Seidl, R; Sekiya, A; Senyo, K; Sevior, M E; Shang, L; Shapkin, M; Shen, C P; Shibuya, H; Shinomiya, S; Shiu, J G; Shwartz, B; Singh, J B; Sokolov, A; Solovieva, E; Somov, A; Stanic, S; Staric, M; Stypula, J; Sugiyama, A; Sumisawa, K; Sumiyoshi, T; Suzuki, S; Suzuki, S Y; Tajima, O; Takasaki, F; Tamai, K; Tamura, N; Tanaka, M; Taniguchi, N; Taylor, G N; Teramoto, Y; Tikhomirov, I; Trabelsi, K; Tse, Y F; Tsuboyama, T; Uchida, K; Uchida, Y; Uehara, S; Ueno, K; Uglov, T; Unno, Y; Uno, S; Urquijo, P; Ushiroda, Y; Usov, Yu; Varner, G; Varvell, K E; Vervink, K; Villa, S; Vinokurova, A; Wang, C C; Wang, C H; Wang, J; Wang, M Z; Wang, P; Wang, X L; Watanabe, M; Watanabe, Y; Wedd, R; Wicht, J; Widhalm, L; Wiechczynski, J; Won, E; Yabsley, B D; Yamaguchi, A; Yamamoto, H; Yamaoka, M; Yamashita, Y; Yamauchi, M; Yuan, C Z; Yusa, Y; Zhang, C C; Zhang, L M; Zhang, Z P; Zhilich, V; Zhulanov, V; Zupanc, A; Zwahlen, N

    2007-01-01

    We search for the decay B0 -> rho0rho0 and other possible charmless modes with a pi+pi-pi+pi- final state, including B0 -> rho0f0(980), B0 -> f0(980)f0(980), B0 -> f0(980)pipi, B0 -> rho0pipi and non-resonant B0 -> 4pi. These results are obtained from a data sample containing 520 x 10^6 BBar pairs collected by the Belle detector at the KEKB asymmetric-energy e+e- collider. We measure a branching fraction of (0.9 +/- 0.4^{+0.3}_{-0.4}) x 10^{-6}, or B(B0 -> rho0rho0) 4pi decay to be (10.2 +/- 4.7^{+2.3}_{-1.5}) x 10^{-6} with 2.1\\sigma significance, and set the 90% confidence level upper limit B(B0 -> 4pi) rho0f0(980), B0 -> f0(980)f0(980), B0 -> f0(980)pipi and B0 -> rho0pipi, no significant signals are observed and upper limits on the branching fractions are set.

  7. Amplitude chimeras and chimera death in dynamical networks

    Science.gov (United States)

    Zakharova, Anna; Kapeller, Marie; Schöll, Eckehard

    2016-06-01

    We find chimera states with respect to amplitude dynamics in a network of Stuart- Landau oscillators. These partially coherent and partially incoherent spatio-temporal patterns appear due to the interplay of nonlocal network topology and symmetry-breaking coupling. As the coupling range is increased, the oscillations are quenched, amplitude chimeras disappear and the network enters a symmetry-breaking stationary state. This particular regime is a novel pattern which we call chimera death. It is characterized by the coexistence of spatially coherent and incoherent inhomogeneous steady states and therefore combines the features of chimera state and oscillation death. Additionally, we show two different transition scenarios from amplitude chimera to chimera death. Moreover, for amplitude chimeras we uncover the mechanism of transition towards in-phase synchronized regime and discuss the role of initial conditions.

  8. Quantum signatures of chimera states

    Science.gov (United States)

    Bastidas, V. M.; Omelchenko, I.; Zakharova, A.; Schöll, E.; Brandes, T.

    2015-12-01

    Chimera states are complex spatiotemporal patterns in networks of identical oscillators, characterized by the coexistence of synchronized and desynchronized dynamics. Here we propose to extend the phenomenon of chimera states to the quantum regime, and uncover intriguing quantum signatures of these states. We calculate the quantum fluctuations about semiclassical trajectories and demonstrate that chimera states in the quantum regime can be characterized by bosonic squeezing, weighted quantum correlations, and measures of mutual information. Our findings reveal the relation of chimera states to quantum information theory, and give promising directions for experimental realization of chimera states in quantum systems.

  9. Chimera: Experiencing Language Arts.

    Science.gov (United States)

    Paul, Rebecca K.

    1991-01-01

    Describes the production of a dramatic musical, Chimera: A Journey to Redoubtia, at Chapman Elementary School in Anchor Point, Alaska. Student participation in the project, and students' rewards from participation, are detailed. Benefits of the integration of dramatics into the language arts curriculum are listed. (BB)

  10. Chimera and globally clustered chimera: Impact of time delay

    OpenAIRE

    Sheeba, Jane H.; Chandrasekar, V. K.; Lakshmanan, M.

    2010-01-01

    Following a short report of our preliminary results [Phys. Rev. E 79, 055203(R) (2009)], we present a more detailed study of the effects of coupling delay in diffusively coupled phase oscillator populations. We find that coupling delay induces chimera and globally clustered chimera (GCC) states in delay coupled populations. We show the existence of multi-clustered states that act as link between the chimera and the GCC states. A stable GCC state goes through a variety of GCC states, namely pe...

  11. Amplitude chimeras and chimera death in dynamical networks

    OpenAIRE

    Zakharova, Anna; Kapeller, Marie; Schöll, Eckehard

    2015-01-01

    We find chimera states with respect to amplitude dynamics in a network of Stuart-Landau oscillators. These partially coherent and partially incoherent spatio-temporal patterns appear due to the interplay of nonlocal network topology and symmetry-breaking coupling. As the coupling range is increased, the oscillations are quenched, amplitude chimeras disappear and the network enters a symmetry-breaking stationary state. This particular regime is a novel pattern which we call chimera death. It i...

  12. Chimera states in bursting neurons

    Science.gov (United States)

    Bera, Bidesh K.; Ghosh, Dibakar; Lakshmanan, M.

    2016-01-01

    We study the existence of chimera states in pulse-coupled networks of bursting Hindmarsh-Rose neurons with nonlocal, global, and local (nearest neighbor) couplings. Through a linear stability analysis, we discuss the behavior of the stability function in the incoherent (i.e., disorder), coherent, chimera, and multichimera states. Surprisingly, we find that chimera and multichimera states occur even using local nearest neighbor interaction in a network of identical bursting neurons alone. This is in contrast with the existence of chimera states in populations of nonlocally or globally coupled oscillators. A chemical synaptic coupling function is used which plays a key role in the emergence of chimera states in bursting neurons. The existence of chimera, multichimera, coherent, and disordered states is confirmed by means of the recently introduced statistical measures and mean phase velocity.

  13. Cellular automaton for chimera states

    OpenAIRE

    García-Morales, Vladimir

    2016-01-01

    A minimalistic model for chimera states is presented. The model is a cellular automaton (CA) which depends on only one adjustable parameter, the range of the nonlocal coupling, and is built from elementary cellular automata and the majority (voting) rule. This suggests the universality of chimera-like behavior from a new point of view: Already simple CA rules based on the majority rule exhibit this behavior. After a short transient, we find chimera states for arbitrary initial conditions, the...

  14. Quantum signatures of Chimera states

    OpenAIRE

    Bastidas, V. M.; Omelchenko, I.; ZAKHAROVA, A.; Schöll, E.; Brandes, T.

    2015-01-01

    Chimera states are complex spatiotemporal patterns in networks of identical oscillators, characterized by the coexistence of synchronized and desynchronized dynamics. Here we propose to extend the phenomenon of chimera states to the quantum regime, and uncover intriguing quantum signatures of these states. We calculate the quantum fluctuations about semiclassical trajectories and demonstrate that chimera states in the quantum regime can be characterized by bosonic squeezing, weighted quantum ...

  15. Chimera and other fertilization errors.

    Science.gov (United States)

    Malan, V; Vekemans, M; Turleau, C

    2006-11-01

    The finding of a mixture of 46,XX and 46,XY cells in an individual has been rarely reported in literature. It usually results in individuals with ambiguous genitalia. Approximately 10% of true human hermaphrodites show this type of karyotype. However, the underlying mechanisms are poorly understood. It may be the result of mosaicism or chimerism. By definition, a chimera is produced by the fusion of two different zygotes in a single embryo, while a mosaic contains genetically different cells issued from a single zygote. Several mechanisms are involved in the production of chimera. Stricto sensu, chimerism occurs from the post-zygotic fusion of two distinct embryos leading to a tetragametic chimera. In addition, there are other entities, which are also referred to as chimera: parthenogenetic chimera and chimera resulting from fertilization of the second polar body. Furthermore, a particular type of chimera called 'androgenetic chimera' recently described in fetuses with placental mesenchymal dysplasia and in rare patients with Beckwith-Wiedemann syndrome is discussed. Strategies to study mechanisms leading to the production of chimera and mosaics are also proposed.

  16. Chimera Grid Tools

    Science.gov (United States)

    Chan, William M.; Rogers, Stuart E.; Nash, Steven M.; Buning, Pieter G.; Meakin, Robert

    2005-01-01

    Chimera Grid Tools (CGT) is a software package for performing computational fluid dynamics (CFD) analysis utilizing the Chimera-overset-grid method. For modeling flows with viscosity about geometrically complex bodies in relative motion, the Chimera-overset-grid method is among the most computationally cost-effective methods for obtaining accurate aerodynamic results. CGT contains a large collection of tools for generating overset grids, preparing inputs for computer programs that solve equations of flow on the grids, and post-processing of flow-solution data. The tools in CGT include grid editing tools, surface-grid-generation tools, volume-grid-generation tools, utility scripts, configuration scripts, and tools for post-processing (including generation of animated images of flows and calculating forces and moments exerted on affected bodies). One of the tools, denoted OVERGRID, is a graphical user interface (GUI) that serves to visualize the grids and flow solutions and provides central access to many other tools. The GUI facilitates the generation of grids for a new flow-field configuration. Scripts that follow the grid generation process can then be constructed to mostly automate grid generation for similar configurations. CGT is designed for use in conjunction with a computer-aided-design program that provides the geometry description of the bodies, and a flow-solver program.

  17. Emergence of multicluster chimera states

    Science.gov (United States)

    Yao, Nan; Huang, Zi-Gang; Grebogi, Celso; Lai, Ying-Cheng

    2015-09-01

    A remarkable phenomenon in spatiotemporal dynamical systems is chimera state, where the structurally and dynamically identical oscillators in a coupled networked system spontaneously break into two groups, one exhibiting coherent motion and another incoherent. This phenomenon was typically studied in the setting of non-local coupling configurations. We ask what can happen to chimera states under systematic changes to the network structure when links are removed from the network in an orderly fashion but the local coupling topology remains invariant with respect to an index shift. We find the emergence of multicluster chimera states. Remarkably, as a parameter characterizing the amount of link removal is increased, chimera states of distinct numbers of clusters emerge and persist in different parameter regions. We develop a phenomenological theory, based on enhanced or reduced interactions among oscillators in different spatial groups, to explain why chimera states of certain numbers of clusters occur in certain parameter regions. The theoretical prediction agrees well with numerics.

  18. Immune tolerance in radiation chimeras

    International Nuclear Information System (INIS)

    Establishment of immune tolerance in radiation chimeras and the mechanism of maintaining it were discussed from certain points. Semiallogeneic radiation chimeras are mostly of long-living, and the hematopoietic organ of this individual consists mainly of the cells derived from the marrow donor, i. e., F1-type cells. F1-type lymphocytes can distinguish parental strain cells from themselves. In these chimeras, a F1-skin graft maintains to be fresh as long as the host is alive, showing immune tolerance effective through its life. In establishment and maintenance of this immune tolerance, the suppressing mechanism of host-type or F1-type seems to be involved. The allogeneic radiation chimera has very poor long-survival rate compared with that of the semiallogeneic radiation chimera. To raise this survival rate, efforts are now being made from the immunological point of view. (Ueda, J.)

  19. Recurrence quantification analysis of chimera states

    Energy Technology Data Exchange (ETDEWEB)

    Santos, M.S. [Pós-Graduação em Ciências/Física, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR (Brazil); Szezech, J.D., E-mail: jdanilo@gmail.com [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR (Brazil); Batista, A.M., E-mail: antoniomarcosbatista@gmail.com [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR (Brazil); Caldas, I.L. [Instituto de Física, Universidade de São Paulo, 05315-970, São Paulo, SP (Brazil); Viana, R.L.; Lopes, S.R. [Departamento de Física, Universidade Federal do Paraná, 81531-990, Curitiba, PR (Brazil)

    2015-10-02

    Chimera states, characterised by coexistence of coherence and incoherence in coupled dynamical systems, have been found in various physical systems, such as mechanical oscillator networks and Josephson-junction arrays. We used recurrence plots to provide graphical representations of recurrent patterns and identify chimera states. Moreover, we show that recurrence plots can be used as a diagnostic of chimera states and also to identify the chimera collapse. - Highlights: • Chimera states have been found in various physical systems. • Recurrence plots is a graphical method useful to locate recurring patterns. • We used recurrence plots to identify the chimera states. • We show also the recurrence plots can identify the chimera collapse.

  20. Recurrence quantification analysis of chimera states

    International Nuclear Information System (INIS)

    Chimera states, characterised by coexistence of coherence and incoherence in coupled dynamical systems, have been found in various physical systems, such as mechanical oscillator networks and Josephson-junction arrays. We used recurrence plots to provide graphical representations of recurrent patterns and identify chimera states. Moreover, we show that recurrence plots can be used as a diagnostic of chimera states and also to identify the chimera collapse. - Highlights: • Chimera states have been found in various physical systems. • Recurrence plots is a graphical method useful to locate recurring patterns. • We used recurrence plots to identify the chimera states. • We show also the recurrence plots can identify the chimera collapse

  1. Cellular automaton for chimera states

    Science.gov (United States)

    García-Morales, Vladimir

    2016-04-01

    A minimalistic model for chimera states is presented. The model is a cellular automaton (CA) which depends on only one adjustable parameter, the range of the nonlocal coupling, and is built from elementary cellular automata and the majority (voting) rule. This suggests the universality of chimera-like behavior from a new point of view: Already simple CA rules based on the majority rule exhibit this behavior. After a short transient, we find chimera states for arbitrary initial conditions, the system spontaneously splitting into stable domains separated by static boundaries, some synchronously oscillating and the others incoherent. When the coupling range is local, nontrivial coherent structures with different periodicities are formed.

  2. Focusing characteristics of a 4$\\pi$ parabolic mirror light-matter interface

    CERN Document Server

    Alber, Lucas; Bader, Marianne; Mantel, Klaus; Sondermann, Markus; Leuchs, Gerd

    2016-01-01

    Focusing with a 4$\\pi$ parabolic mirror allows for concentrating light from nearly the complete solid angle. So far, this idea could not be exploited to enable diffraction limited focusing from more than half solid angle. We present the focusing properties of a 4$\\pi$ parabolic mirror experimentally characterized with a single $^{174}$Yb$^{+}$ ion as a mobile point scatterer. The ion is trapped in a vacuum environment with a movable high optical access Paul trap. We demonstrate an effective focal spot size of 209 nm in lateral and 551 nm in axial direction. Such tight focusing allows us to build an efficient light-matter interface. Our findings agree with numerical simulations incorporating a finite ion temperature and interferometrically measured wavefront aberrations induced by the parabolic mirror. We point at further technological improvements and discuss the general scope of applications of a 4$\\pi$ parabolic mirror.

  3. Enstore with Chimera namespace provider

    International Nuclear Information System (INIS)

    Enstore is a mass storage system developed by Fermilab that provides distributed access and management of data stored on tapes. It uses a namespace service, PNFS, developed by DESY to provide a filesystem-like view of the stored data. PNFS is a legacy product and is being replaced by a new implementation, called Chimera, which is also developed by DESY. Chimera offers multiple advantages over PNFS in terms of performance and functionality. The Enstore client component, encp, has been modified to work with Chimera, as well as with any other namespace provider. We performed high load end-to-end acceptance test of Enstore with the Chimera namespace. This paper describes the modifications to Enstore, the test procedure and the results of the acceptance testing.

  4. Monte Carlo simulation to positron emitter standardized by means of 4{pi}{beta}-{gamma} coincidence system-Application to {sup 22}Na

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Mauro S., E-mail: msdias@ipen.b [Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP, Centro do Reator de Pesquisas - CRPq, C.P. 11049, Pinheiros, 05422-970 Sao Paulo, SP (Brazil); Tongu, Margareth L.O.; Takeda, Mauro N.; Koskinas, Marina F. [Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP, Centro do Reator de Pesquisas - CRPq, C.P. 11049, Pinheiros, 05422-970 Sao Paulo, SP (Brazil)

    2010-07-15

    The present work describes the methodology for predicting the behavior of extrapolation curves obtained in radionuclide standardization by 4{pi}{beta}-{gamma} coincidence measurements, applied to {sup 22}Na, developed at the Laboratorio de Metrologia Nuclear of IPEN-CNEN/SP (LMN-Nuclear Metrology Laboratory). The LMN system consists of a proportional counter (PC) in 4{pi} geometry coupled to a single or a pair of NaI(Tl) scintillation crystals. Two standardization techniques were used: the Sum-Peak and the Nuclear-Peak methods. The theoretical response functions of each detector have been calculated using the MCNPX Monte Carlo code. The code ESQUEMA, developed at LMN, has been used for calculating the extrapolation curve in the 4{pi}{beta}-{gamma} coincidence experiment. Modifications were performed in order to include response tables for positrons and coincidences with annihilation photons. From the calibration results it was possible to extract both the activity value and the positron emission probability per decay. The latter was compared with results from the literature.

  5. Emergence of multicluster chimera states

    OpenAIRE

    Nan Yao; Zi-Gang Huang; Celso Grebogi; Ying-Cheng Lai

    2015-01-01

    A remarkable phenomenon in spatiotemporal dynamical systems is chimera state, where the structurally and dynamically identical oscillators in a coupled networked system spontaneously break into two groups, one exhibiting coherent motion and another incoherent. This phenomenon was typically studied in the setting of non-local coupling configurations. We ask what can happen to chimera states under systematic changes to the network structure when links are removed from the network in an orderly ...

  6. Chimera states in Star Networks

    OpenAIRE

    Meena, Chandrakala; Murali, K.; Sinha, Sudeshna

    2015-01-01

    We consider star networks of chaotic oscillators, with all end-nodes connected only to the central hub node, under diffusive coupling, conjugate coupling and mean-field type coupling. We observe the existence of chimeras in the end-nodes, which are identical in terms of the coupling environment and dynamical equations. Namely, the symmetry of the end-nodes is broken and co-existing groups with different synchronization features and attractor geometries emerge. Surprisingly, such chimera state...

  7. Chimera order in spin systems

    OpenAIRE

    Singh, Rajeev; Dasgupta, Subinay; Sinha, Sitabhra

    2010-01-01

    Homogeneous populations of oscillators have recently been shown to exhibit stable coexistence of coherent and incoherent regions. Generalizing the concept of chimera states to the context of order-disorder transition in systems at thermal equilibrium, we show analytically that such complex ordering can appear in a system of Ising spins, possibly the simplest physical system exhibiting this phenomenon. We also show numerically the existence of chimera ordering in 3-dimensional spin systems tha...

  8. Chimera States for Coupled Oscillators

    OpenAIRE

    Abrams, Daniel M.; Strogatz, Steven H.

    2004-01-01

    Arrays of identical oscillators can display a remarkable spatiotemporal pattern in which phase-locked oscillators coexist with drifting ones. Discovered two years ago, such "chimera states" are believed to be impossible for locally or globally coupled systems; they are peculiar to the intermediate case of nonlocal coupling. Here we present an exact solution for this state, for a ring of phase oscillators coupled by a cosine kernel. We show that the stable chimera state bifurcates from a spati...

  9. A classification scheme for chimera states

    Science.gov (United States)

    Kemeth, Felix P.; Haugland, Sindre W.; Schmidt, Lennart; Kevrekidis, Ioannis G.; Krischer, Katharina

    2016-09-01

    We present a universal characterization scheme for chimera states applicable to both numerical and experimental data sets. The scheme is based on two correlation measures that enable a meaningful definition of chimera states as well as their classification into three categories: stationary, turbulent, and breathing. In addition, these categories can be further subdivided according to the time-stationarity of these two measures. We demonstrate that this approach is both consistent with previously recognized chimera states and enables us to classify states as chimeras which have not been categorized as such before. Furthermore, the scheme allows for a qualitative and quantitative comparison of experimental chimeras with chimeras obtained through numerical simulations.

  10. HI4PI: A full-sky HI survey based on EBHIS and GASS

    CERN Document Server

    Bekhti, N Ben; Keller, R; Kerp, J; Lenz, D; Winkel, B; Bailin, J; Calabretta, M R; Dedes, L; Ford, H A; Gibson, B K; Haud, U; Janowiecki, S; Kalberla, P M W; Lockman, F J; McClure-Griffiths, N M; Murphy, T; Nakanishi, H; Pisano, D J; Staveley-Smith, L

    2016-01-01

    Measurement of the Galactic neutral atomic hydrogen (HI) column density, NHI, and brightness temperatures, Tb, is of high scientific value for a broad range of astrophysical disciplines. In the past two decades, one of the most-used legacy HI datasets has been the Leiden/Argentine/Bonn Survey (LAB). We release the HI 4$\\pi$ survey (HI4PI), an all-sky database of Galactic HI, which supersedes the LAB survey. The HI4PI survey is based on data from the recently completed first coverage of the Effelsberg-Bonn HI Survey (EBHIS) and from the third revision of the Galactic All-Sky Survey (GASS). EBHIS and GASS share similar angular resolution and match well in sensitivity. Combined, they are ideally suited to be a successor to LAB. The new HI4PI survey outperforms the LAB in angular resolution (16.2', FWHM) and sensitivity (RMS: 43 mK). Moreover, it has full spatial sampling and thus overcomes a major drawback of LAB, which severely undersamples the sky. We publish all-sky column density maps of the neutral atomic h...

  11. Measurement of electro-sprayed 238 and 239+240 plutonium isotopes using 4{pi}-alpha spectrometry. Application to environmental samples; Spectrometrie alpha 4{pi} de sources d'actinides realisees par electronebulisation. Developpement et optimisation d'un protocole applique au mesurage des isotopes 238 et 239+240 du plutonium dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Charmoille-Roblot, M. [CEA/Fontenay-aux-Roses, Dept. de Protection de l' Environnement (DPRE), 92 (France)]|[Paris-11 Univ., 91 - Orsay (France)

    1999-07-01

    A new protocol for plutonium deposition using the electro-spray technique coupled with 4{pi}-{alpha} spectrometry is proposed to improve the detection limit, shorten the counting time. In order to increase the detection efficiency, it was proposed to measure 238 and 239+240 plutonium isotopes electro-sprayed deposit simultaneously on both sides of the source support, that must be as transparent as possible to alpha-emissions, in a two-alpha detectors chamber. A radiochemical protocol was adapted to electro-spray constraints and a very thin carbon foil was selected for 4{pi} -alpha spectrometry. The method was applied to a batch of sediment samples and gave the same results as an electrodeposited source measured using conventional alpha spectrometry with a 25 % gain on counting time and 10 % on plutonium 238 detection limit. Validation and application of the technique have been made on reference samples. (author)

  12. Chimera and globally clustered chimera: Impact of time delay

    CERN Document Server

    Sheeba, Jane H; Lakshmanan, M

    2010-01-01

    Following a short report of our preliminary results [Phys. Rev. E 79, 055203(R) (2009)], we present a more detailed study of the effects of coupling delay in diffusively coupled phase oscillator populations. We find that coupling delay induces chimera and globally clustered chimera (GCC) states in delay coupled populations. We show the existence of multi-clustered states that act as link between the chimera and the GCC states. A stable GCC state goes through a variety of GCC states, namely periodic, aperiodic, long-- and short--period breathers and becomes unstable GCC leading to global synchronization in the system, on increasing time delay. We provide numerical evidence and theoretical explanations for the above results and discuss possible applications of the observed phenomena.

  13. Recurrence quantification analysis of chimera states

    Science.gov (United States)

    Santos, M. S.; Szezech, J. D.; Batista, A. M.; Caldas, I. L.; Viana, R. L.; Lopes, S. R.

    2015-10-01

    Chimera states, characterised by coexistence of coherence and incoherence in coupled dynamical systems, have been found in various physical systems, such as mechanical oscillator networks and Josephson-junction arrays. We used recurrence plots to provide graphical representations of recurrent patterns and identify chimera states. Moreover, we show that recurrence plots can be used as a diagnostic of chimera states and also to identify the chimera collapse.

  14. Emergence of chimera in multiplex network

    OpenAIRE

    Ghosh, Saptarshi; Jalan, Sarika

    2015-01-01

    Chimera is a relatively new emerging phenomenon where coexistence of synchronous and asynchronous state is observed in symmetrically coupled dynamical units. We report observation of the chimera state in multiplex networks where individual layer is represented by 1-d lattice with non-local interactions. While, multiplexing does not change the type of the chimera state and retains the multi-chimera state displayed by the isolated networks, it changes the regions of the incoherence. We investig...

  15. Chimera states in three dimensions

    Science.gov (United States)

    Maistrenko, Yuri; Sudakov, Oleksandr; Osiv, Oleksiy; Maistrenko, Volodymyr

    2015-07-01

    The chimera state is a recently discovered dynamical phenomenon in arrays of nonlocally coupled oscillators, that displays a self-organized spatial pattern of coexisting coherence and incoherence. In this paper, the first evidence of three-dimensional chimera states is reported for the Kuramoto model of phase oscillators in 3D grid topology with periodic boundary conditions. Systematic analysis of the dependence of the spatiotemporal dynamics on the range and strength of coupling shows that there are two principal classes of the chimera patterns which exist in large domains of the parameter space: (I) oscillating and (II) spirally rotating. Characteristic examples from the first class include coherent as well as incoherent balls, tubes, crosses, and layers in incoherent or coherent surrounding; the second class includes scroll waves with incoherent, randomized rolls of different modality and dynamics. Numerical simulations started from various initial conditions indicate that the states are stable over the integration time. Videos of the dynamics of the chimera states are presented in supplementary material. It is concluded that three-dimensional chimera states, which are novel spatiotemporal patterns involving the coexistence of coherent and incoherent domains, can represent one of the inherent features of nature.

  16. Standardization of 56Co had been carried out using 4 pi beta-gamma coincidence methods

    International Nuclear Information System (INIS)

    Standardization of exp.56 Co had been carried out using 4 pi beta-gamma coincidence methods. The radionuclide use for calibration of nuclear instruments on range of energy over 1500 keV. The exp.56 Co had been produced by irradiation of proton by using a cyclotron with 15 MeV of energy and 300 mb of cross-section to natural iron target (99,5% of purity) at the Institute for Nuclear Study, University of Tokyo. Source preparation had been done by gravimetry method after the irradiated source was dissolved in 8N HCI solution. The disintegration rate had been measured using 4 pi beta-gamma coincidence apparatus, where the gamm gets sets on 511 and 847 keV gamma-rays. The result measurement is fairly good with the specific activity is 3078 n 15 Bq/mg

  17. First measurement of F_+^{4\\pi} in D ->4\\pi decays and a new method for measuring CPV in charm decays

    CERN Document Server

    Malde, Sneha

    2015-01-01

    A first measurement of \\fplus, the \\CP-even content of the decay D->4pi using decays of $\\psi(3770)$ to quantum correlated $D\\bar{D}$ decays collected by the CLEO-c experiment is presented. The measured value is \\fplus=$0.737 \\pm 0.028$. This relatively high value makes the decay mode particularly suitable for both measurements of the CKM angle $\\gamma$ and charm \\CP-violation in a model independent way. This novel approach to studying indirect \\CP-violation in charm decays is based on the time-dependent inclusive analysis of multi body self-conjugate states. These final states can be used to determine the indirect CP-violating observable $A_{\\Gamma}$ and the mixing observable $y_{CP}$ provided that $F_+$ is known. This approach can yield significantly improved sensitivity compared with the conventional method that relies on decays to \\CP~eigenstates.

  18. HI4PI: A full-sky H I survey based on EBHIS and GASS

    Science.gov (United States)

    HI4PI Collaboration; Ben Bekhti, N.; Flöer, L.; Keller, R.; Kerp, J.; Lenz, D.; Winkel, B.; Bailin, J.; Calabretta, M. R.; Dedes, L.; Ford, H. A.; Gibson, B. K.; Haud, U.; Janowiecki, S.; Kalberla, P. M. W.; Lockman, F. J.; McClure-Griffiths, N. M.; Murphy, T.; Nakanishi, H.; Pisano, D. J.; Staveley-Smith, L.

    2016-10-01

    Context. Measurement of the Galactic neutral atomic hydrogen (H I) column density, NH I, and brightness temperatures, TB, is of high scientific value for a broad range of astrophysical disciplines. In the past two decades, one of the most-used legacy H I datasets has been the Leiden/Argentine/Bonn Survey (LAB). Aims: We release the H I 4π survey (HI4PI), an all-sky database of Galactic H I, which supersedes the LAB survey. Methods: The HI4PI survey is based on data from the recently completed first coverage of the Effelsberg-Bonn H I Survey (EBHIS) and from the third revision of the Galactic All-Sky Survey (GASS). EBHIS and GASS share similar angular resolution and match well in sensitivity. Combined, they are ideally suited to be a successor to LAB. Results: The new HI4PI survey outperforms the LAB in angular resolution (ϑFWHM = 16´´.2) and sensitivity (σrms = 43 mK). Moreover, it has full spatial sampling and thus overcomes a major drawback of LAB, which severely undersamples the sky. We publish all-sky column density maps of the neutral atomic hydrogen in the Milky Way, along with full spectroscopic data, in several map projections including HEALPix. HI4PI datasets are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/594/A116

  19. Renormalization group flow equations from the 4PI equations of motion

    CERN Document Server

    Carrington, M E

    2013-01-01

    The 4PI effective action provides a a hierarchy of integral equations which have the form of Bethe-Salpeter equations. The vertex functions obtained from these equations can be used to truncate the exact renormalization group flow equations. This truncation has the property that the flow is a total derivative with respect to the flow parameter and is equivalent to solving the nPI equations of motion. This result establishes a direct connection between two non-perturbative methods.

  20. Ethical considerations in chimera research.

    Science.gov (United States)

    Hermerén, Göran

    2015-01-01

    The development of human pluripotent stem cells has opened up the possibility to analyse the function of human cells and tissues in animal hosts, thus generating chimeras. Although such lines of research have great potential for both basic and translational science, they also raise unique ethical issues that must be considered.

  1. Idealised hydrodynamic simulations of turbulent oxygen-burning shell convection in 4{\\pi} geometry

    OpenAIRE

    Jones, Samuel; Andrassy, Robert; Sandalski, Stou; Davis, Austin; Woodward, Paul; Herwig, Falk

    2016-01-01

    This work investigates the properties of convection in stars with particular emphasis on entrainment across the upper convective boundary (CB). Idealised simulations of turbulent convection in the O-burning shell of a massive star are performed in $4\\pi$ geometry on $768^3$ and $1536^3$ grids, driven by a representative heating rate. A heating series is also performed on the $768^3$ grid. The $1536^3$ simulation exhibits an entrainment rate at the upper CB of $1.33\\times10^{-6}~M_\\odot~\\mathr...

  2. Tweezers for Chimeras in Small Networks

    Science.gov (United States)

    Omelchenko, Iryna; Omel'chenko, Oleh E.; Zakharova, Anna; Wolfrum, Matthias; Schöll, Eckehard

    2016-03-01

    We propose a control scheme which can stabilize and fix the position of chimera states in small networks. Chimeras consist of coexisting domains of spatially coherent and incoherent dynamics in systems of nonlocally coupled identical oscillators. Chimera states are generally difficult to observe in small networks due to their short lifetime and erratic drifting of the spatial position of the incoherent domain. The control scheme, like a tweezer, might be useful in experiments, where usually only small networks can be realized.

  3. Chimera patterns under the impact of noise

    OpenAIRE

    Loos, Sarah A. M.; Claussen, Jens Christian; Schöll, Eckehard; Zakharova, Anna

    2015-01-01

    We investigate two types of chimera states, i.e., patterns consisting of coexisting spatially separated domains with coherent and incoherent dynamics, in ring networks of Stuart-Landau oscillators with symmetry-breaking coupling, under the influence of noise. Amplitude chimeras are characterized by temporally periodic dynamics throughout the whole network, but spatially incoherent behavior with respect to the amplitudes in a part of the system; they are long-living transients. Chimera death s...

  4. Enhancing UCSF Chimera through web services

    OpenAIRE

    Huang, CC; Meng, EC; Morris, JH; Pettersen, EF; Ferrin, TE

    2014-01-01

    Integrating access to web services with desktop applications allows for an expanded set of application features, including performing computationally intensive tasks and convenient searches of databases. We describe how we have enhanced UCSF Chimera (http://www.rbvi.ucsf.edu/chimera/), a program for the interactive visualization and analysis of molecular structures and related data, through the addition of several web services (http://www.rbvi.ucsf.edu/chimera/ docs/webservices.html). By stre...

  5. A Tweezer for Chimeras in Small Networks

    OpenAIRE

    Omelchenko, Iryna; Omel'chenko, Oleh E.; Zakharova, Anna; Wolfrum, Matthias; Schoell, Eckehard

    2015-01-01

    We propose a control scheme which can stabilize and fix the position of chimera states in small networks. Chimeras consist of coexisting domains of spatially coherent and incoherent dynamics in systems of nonlocally coupled identical oscillators. Chimera states are generally difficult to observe in small networks due to their short lifetime and erratic drifting of the spatial position of the incoherent domain. The control scheme, like a tweezer, might be useful in experiments, where usually o...

  6. Pinning control of chimera states

    Science.gov (United States)

    Gambuzza, Lucia Valentina; Frasca, Mattia

    2016-08-01

    The position of the coherent and incoherent domain of a chimera state in a ring of nonlocally coupled oscillators is strongly influenced by the initial conditions, making nontrivial the problem of confining them in a specific region of the structure. In this paper we propose the use of spatial pinning to induce a chimera state where the nodes belonging to one domain, either the coherent or the incoherent, are fixed by the control action. We design two different techniques according to the dynamics to be forced in the region of pinned nodes, and validate them on FitzHugh-Nagumo and Kuramoto oscillators. Furthermore, we introduce a suitable strategy to deal with the effects of finite size in small structures.

  7. Pinning control of chimera states.

    Science.gov (United States)

    Gambuzza, Lucia Valentina; Frasca, Mattia

    2016-08-01

    The position of the coherent and incoherent domain of a chimera state in a ring of nonlocally coupled oscillators is strongly influenced by the initial conditions, making nontrivial the problem of confining them in a specific region of the structure. In this paper we propose the use of spatial pinning to induce a chimera state where the nodes belonging to one domain, either the coherent or the incoherent, are fixed by the control action. We design two different techniques according to the dynamics to be forced in the region of pinned nodes, and validate them on FitzHugh-Nagumo and Kuramoto oscillators. Furthermore, we introduce a suitable strategy to deal with the effects of finite size in small structures. PMID:27627316

  8. 4{pi} studies of the 1.8-4.8 GeV {sup 3}He+{sup nat}Ag, {sup 197}Au reactions. I. Energy deposition

    Energy Technology Data Exchange (ETDEWEB)

    Morley, K.B.; Kwiatkowski, K.; Bracken, D.S.; Renshaw Foxford, E. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry; Legrain, R.; Pollacco, E.C.; Volant, C. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee; Korteling, R.G. [Simon Fraser Univ., Burnaby, BC (Canada). Dept. of Chemistry; Breuer, H. [Maryland Univ., College Park, MD (United States). Dept. of Physics; Brzychczyk, J. [Jagellonian Univ., Krakow (Poland). Inst. of Physics

    1996-01-01

    The 4{pi} detector ISiS has been used to measure light-charged particles and intermediate-mass-fragments emitted in the 1.8-4.8 GeV {sup 3}He+{sup nat}Ag, {sup 197}Au reactions. Ejectile multiplicity and total event kinetic energy distribution scale systematically with projectile energy and target mass, except for the {sup nat}Ag target at 3.6 and 4.8 GeV. For this system, a saturation in deposition energy is indicated by the data, suggesting the upper projectile energy for stopping has been reached. Maximum deposition energies of {approx}950 MeV for the {sup nat}Ag target and {approx}1600 MeV for the {sup 197}Au target are inferred from the data. Comparison of the experimental distributions with intranuclear cascade predictions shows qualitative agreement. (author). Submitted to Physical Review, C (US); 46 refs.

  9. Chimera patterns under the impact of noise

    Science.gov (United States)

    Loos, Sarah A. M.; Claussen, Jens Christian; Schöll, Eckehard; Zakharova, Anna

    2016-01-01

    We investigate two types of chimera states, patterns consisting of coexisting spatially separated domains with coherent and incoherent dynamics, in ring networks of Stuart-Landau oscillators with symmetry-breaking coupling, under the influence of noise. Amplitude chimeras are characterized by temporally periodic dynamics throughout the whole network, but spatially incoherent behavior with respect to the amplitudes in a part of the system; they are long-living transients. Chimera death states generalize chimeras to stationary inhomogeneous patterns (oscillation death), which combine spatially coherent and incoherent domains. We analyze the impact of random perturbations, addressing the question of robustness of chimera states in the presence of white noise. We further consider the effect of symmetries applied to random initial conditions.

  10. The smallest chimera state for coupled pendula

    Science.gov (United States)

    Wojewoda, Jerzy; Czolczynski, Krzysztof; Maistrenko, Yuri; Kapitaniak, Tomasz

    2016-01-01

    Chimera states in the systems of coupled identical oscillators are spatiotemporal patterns in which different groups of oscillators can exhibit coexisting synchronous and incoherent behaviors despite homogeneous coupling. Although these states are typically observed in large ensembles of oscillators, recently it has been suggested that chimera states may occur in the systems with small numbers of oscillators. Here, considering three coupled pendula showing chaotic behavior, we find the pattern of the smallest chimera state, which is characterized by the coexistence of two synchronized and one incoherent oscillator. We show that this chimera state can be observed in simple experiments with mechanical oscillators, which are controlled by elementary dynamical equations derived from Newton’s laws. Our finding suggests that chimera states are observable in small networks relevant to various real-world systems. PMID:27713483

  11. Imperfect chimera states for coupled pendula.

    Science.gov (United States)

    Kapitaniak, Tomasz; Kuzma, Patrycja; Wojewoda, Jerzy; Czolczynski, Krzysztof; Maistrenko, Yuri

    2014-01-01

    The phenomenon of chimera states in the systems of coupled, identical oscillators has attracted a great deal of recent theoretical and experimental interest. In such a state, different groups of oscillators can exhibit coexisting synchronous and incoherent behaviors despite homogeneous coupling. Here, considering the coupled pendula, we find another pattern, the so-called imperfect chimera state, which is characterized by a certain number of oscillators which escape from the synchronized chimera's cluster or behave differently than most of uncorrelated pendula. The escaped elements oscillate with different average frequencies (Poincare rotation number). We show that imperfect chimera can be realized in simple experiments with mechanical oscillators, namely Huygens clock. The mathematical model of our experiment shows that the observed chimera states are controlled by elementary dynamical equations derived from Newton's laws that are ubiquitous in many physical and engineering systems.

  12. Simultaneous measurement of (n, {gamma}) and (n, fission) cross sections with the DANCE 4{pi} BaF{sub 2} array

    Energy Technology Data Exchange (ETDEWEB)

    Bredeweg, T.A. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)]. E-mail: toddb@lanl.gov; Fowler, M.M. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Becker, J.A. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Bond, E.M. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Chadwick, M.B. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Clement, R.R.C. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Esch, E.-I. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Ethvignot, T. [CEA-DAM, BP 12, 91680 Bruyeres-le-Chatel (France); Granier, T. [CEA-DAM, BP 12, 91680 Bruyeres-le-Chatel (France); Jandel, M. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Macri, R.A. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); O' Donnell, J.M. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Reifarth, R. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Rundberg, R.S. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Ullmann, J.L. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Vieira, D.J. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Wilhelmy, J.B. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Wouters, J.M. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Wu, C.Y. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2007-08-15

    We have recently begun a program of high precision measurements of Key production and destruction reactions of important radiochemical diagnostic isotopes, including several isotopes of uranium, plutonium and americium. The detector for advanced neutron capture experiments (DANCE), a 4{pi} BaF{sub 2} array located at the Los Alamos Neutron Science Center, will be used to measure the neutron capture cross sections for most of the isotopes of interest. However, neutron capture measurements on many of the actinides are complicated by the presence of prompt {gamma}-rays arising from low energy neutron-induced fission, which competes with neutron capture to varying degrees. Previous measurements of {sup 235}U using the DANCE array have shown that we can partially resolve capture from fission events based on total {gamma}-ray calorimetry (i.e. total {gamma}-ray energy versus {gamma}-ray multiplicity). The addition of a dedicated fission-tagging detector to the DANCE array has greatly improved our ability to separate these two competing processes. In addition to higher quality neutron capture data, the addition of a fission-tagging detector offers a means to determine the capture-to-fission ratio ({sigma} {sub {gamma}}/{sigma} {sub f}) in a single measurement, which should reduce the effect of systematic uncertainties. We are currently using a dual parallel-plate avalanche counter (PPAC) with the target material electro-deposited directly on the center cathode foil. This design provides a high efficiency for detecting fission fragments and allows loading of pre-assembled target/detector assemblies into the neutron beam line at DANCE. Results from tests of the fission-tag detector, as well as preliminary results from measurements on {sup 235}U and {sup 252}Cf that utilized the fission-tag detector will be presented.

  13. Secondary Disease in Radiation Chimeras

    International Nuclear Information System (INIS)

    A review of research dealing directly or indirectly with the development of bidirectional tolerance in radiation chimeras has been made, emphasizing some of the contemporary research on this subject in Oak Ridge and Knoxville. By controlling such factors as cell dose, age of donor animal and day of cell injection, it was possible to achieve bidirectional tolerance. Attempts to reduce bidirectional tolerance in favour of increasing the graft-versus-host reaction were less successful. Hypoxic caging demonstrated a new approach to achieving bidirectional tolerance through physiological competition for growth. Graft-versus-host reactions have a lower growth priority than marrow regeneration or erythropoietic hyperplasia. Study of pathologic processes, immunologic capability and the-biochemical lesions in radiation chimeras all lead to new ideas that involve bidirectional tolerance. The investigations on dose rate in radiation suppression of the immune response and on LD50 (30- to 90-day)values after injection of different numbers of marrow cells all have a bearing on control of the host-versus-graft response and therefore are important in understanding bidirectional tolerance. (author)

  14. Different kinds of chimera death states in nonlocally coupled oscillators

    OpenAIRE

    Premalatha, K.; Chandrasekar, V. K.; Senthilvelan, M.; Lakshmanan, M.

    2015-01-01

    We investigate the significance of nonisochronicity parameter in a network of nonlocally coupled Stuart-Landau oscillators with symmetry breaking form. We observe that the presence of nonisochronicity parameter leads to structural changes in the chimera death region while varying the strength of the interaction. This gives rise to the existence of different types of chimera death states such as multi-chimera death state, type-I periodic chimera death (PCD) state and, type-II periodic chimera ...

  15. Solvable model for chimera states of coupled oscillators.

    Science.gov (United States)

    Abrams, Daniel M; Mirollo, Rennie; Strogatz, Steven H; Wiley, Daniel A

    2008-08-22

    Networks of identical, symmetrically coupled oscillators can spontaneously split into synchronized and desynchronized subpopulations. Such chimera states were discovered in 2002, but are not well understood theoretically. Here we obtain the first exact results about the stability, dynamics, and bifurcations of chimera states by analyzing a minimal model consisting of two interacting populations of oscillators. Along with a completely synchronous state, the system displays stable chimeras, breathing chimeras, and saddle-node, Hopf, and homoclinic bifurcations of chimeras.

  16. Emergence of Chimera in Multiplex Network

    Science.gov (United States)

    Ghosh, Saptarshi; Jalan, Sarika

    2016-06-01

    Chimera is a relatively new emerging phenomenon where coexistence of synchronous and asynchronous states is observed in symmetrically coupled dynamical units. We report the observation of the chimera state in multiplex networks where individual layer is represented by 1-d lattice with nonlocal interactions. While, multiplexing does not change the type of the chimera state and retains the multi-chimera state displayed by the isolated networks, it changes the regions of the incoherence. We investigate the emergence of coherent-incoherent bifurcation upon varying the control parameters, namely, the coupling strength and the network size. Additionally, we investigate the effect of initial condition on the dynamics of the chimera state. Using a measure based on the differences between the neighboring nodes which distinguishes smooth and nonsmooth spatial profiles, we find the critical coupling strength for the transition to the chimera state. Observing chimera in a multiplex network with one-to-one inter layer coupling is important to gain insight to many real world complex systems which inherently posses multilayer architecture.

  17. Chimeras in networks with purely local coupling

    Science.gov (United States)

    Laing, Carlo R.

    2015-11-01

    Chimera states in spatially extended networks of oscillators have some oscillators synchronized while the remainder are asynchronous. These states have primarily been studied in networks with nonlocal coupling, and more recently in networks with global coupling. Here, we present three networks with only local coupling (diffusive, to nearest neighbors) which are numerically found to support chimera states. One of the networks is analyzed using a self-consistency argument in the continuum limit, and this is used to find the boundaries of existence of a chimera state in parameter space.

  18. Measurement of differential (n,x{alpha}) cross section using 4{pi} gridded ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Sanami, Toshiya; Baba, Mamoru; Matsuyama, Shigeo; Kiyosumi, Takehide; Nauchi, Yasushi; Saito, Keiichiro; Hirakawa, Naohiro [Tohoku Univ., Sendai (Japan). Faculty of Engineering; Kawano, Toshihiko

    1997-03-01

    We carried out the measurements of high resolution {alpha} emission spectra of {sup 58}Ni and {sup nat}Ni between 4.5 and 6.5 MeV, and {sup 12}C(n,x{alpha}) cross section using a 4{pi} gridded ionization chamber. In Ni measurement, overall energy resolution was improved to around 200 keV by optimizing a sample thickness and a neutron source width. Measured alpha spectra showed separate peaks corresponding to the ground and low-lying excited states of the residual nucleus ({sup 55}Fe). These results were compared with another direct measurement and statistical model calculations. In {sup 12}C measurement, GIC was applied for (n,x{alpha}) reactions of light nuclei. This application is difficult to (n,x{alpha}) cross sections of light nuclei, because of the influences of large recoil energy and multi-body break-up. We developed new methods which eliminate the effects of recoil nuclei and multi-body break-up and applied them to {sup 12}C(n,x{alpha}) reaction at En=14.1 MeV. In our experiment, the {sup 12}C(n,{alpha}{sub 0}){sup 9}Be angular differential cross section and {sup 12}C(n,n`3{alpha}) cross section were obtained. (author)

  19. Idealised hydrodynamic simulations of turbulent oxygen-burning shell convection in 4{\\pi} geometry

    CERN Document Server

    Jones, Samuel; Sandalski, Stou; Davis, Austin; Woodward, Paul; Herwig, Falk

    2016-01-01

    This work investigates the properties of convection in stars with particular emphasis on entrainment across the upper convective boundary (CB). Idealised simulations of turbulent convection in the O-burning shell of a massive star are performed in $4\\pi$ geometry on $768^3$ and $1536^3$ grids, driven by a representative heating rate. A heating series is also performed on the $768^3$ grid. The $1536^3$ simulation exhibits an entrainment rate at the upper CB of $1.33\\times10^{-6}~M_\\odot~\\mathrm{s}^{-1}$. The $768^3$ simulation with the same heating rate agrees within 17%. The entrainment rate at the upper convective boundary is found to scale linearly with the driving luminosity and with the cube of the shear velocity at the upper boundary, while the radial RMS fluid velocity scales with the cube root of the driving luminosity, as expected. The mixing is analysed in a 1D diffusion framework, resulting in a simple model for CB mixing. The analysis confirms previous findings that limiting the MLT mixing length t...

  20. Aberration control in 4Pi nanoscopy: definitions, properties, and applications (Conference Presentation)

    Science.gov (United States)

    Hao, Xiang; Allgeyer, Edward S.; Velasco, Mary Grace M.; Booth, Martin J.; Bewersdorf, Joerg

    2016-03-01

    The development of fluorescence microscopy, which allows live-cell imaging with high labeling specificity, has made the visualization of cellular architecture routine. However, for centuries, the spatial resolution of optical microscopy was fundamentally limited by diffraction. The past two decades have seen a revolution in far-field optical nanoscopy (or "super-resolution" microscopy). The best 3D resolution is achieved by optical nanoscopes like the isoSTED or the iPALM/4Pi-SMS, which utilize two opposing objective lenses in a coherent manner. These system are, however, also more complex and the required interference conditions demand precise aberration control. Our research involves developing novel adaptive optics techniques that enable high spatial and temporal resolution imaging for biological applications. In this talk, we will discuss how adaptive optics can enhance dual-objective lens nanoscopes. We will demonstrate how adaptive optics devices provide unprecedented freedom to manipulate the light field in isoSTED nanoscopy, allow to realize automatic beam alignment, suppress the inherent side-lobes of the point-spread function, and dynamically compensate for sample-induced aberrations. We will present both the theoretical groundwork and the experimental confirmations.

  1. Twisted chimera states and multicore spiral chimera states on a two-dimensional torus

    Science.gov (United States)

    Xie, Jianbo; Knobloch, Edgar; Kao, Hsien-Ching

    2015-10-01

    Chimera states consisting of domains of coherently and incoherently oscillating oscillators in a two-dimensional periodic array of nonlocally coupled phase oscillators are studied. In addition to the one-dimensional chimera states familiar from one spatial dimension, two-dimensional structures termed twisted chimera states and spiral wave chimera states are identified in simulations. The properties of many of these states, including stability, are determined using an evolution equation for a complex order parameter and are found to be in agreement with the simulations.

  2. Arrangement of a 4Pi microscope for reducing the confocal detection volume with two-photon excitation

    CERN Document Server

    Sandeau, N

    2006-01-01

    The main advantage of two-photon fluorescence confocal microscopy is the low absorption obtained with live tissues at the wavelengths of operation. However, the resolution of two-photon fluorescence confocal microscopes is lower than in the case of one-photon excitation. The 4Pi microscope type C working in two-photon regime, in which the excitation beams are coherently superimposed and, simultaneously, the emitted beams are also coherently added, has shown to be a good solution for increasing the resolution along the optical axis and for reducing the amplitude of the side lobes of the point spread function. However, the resolution in the transverse plane is poorer than in the case of one-photon excitation due to the larger wavelength involved in the two-photon fluorescence process. In this paper we show that a particular arrangement of the 4Pi microscope, referenced as 4Pi0 microscope, is a solution for obtaining a lateral resolution in the two-photon regime similar or even better to that obtained with 4Pi m...

  3. Chimeras

    OpenAIRE

    Huther, Constanze

    2009-01-01

    What types of human-animal interspecific entities are used in biomedical research? Is creating such entities morally wrong? And what do interspecifics tell us about the moral significance of species? This thesis offers an introduction to the field of human-animal interspecifics from a bioethical perspective, with a special focus on the question of speciesism.

  4. Generation of axolotl hematopoietic chimeras

    Directory of Open Access Journals (Sweden)

    David Lopez

    2015-02-01

    Full Text Available Wound repair is an extremely complex process that requires precise coordination between various cell types including immune cells.  Unfortunately, in mammals this usually results in scar formation instead of restoration of the original fully functional tissue, otherwise known as regeneration.  Various animal models like frogs and salamanders are currently being studied to determine the intracellular and intercellular pathways, controlled by gene expression, that elicit cell proliferation, differentiation, and migration of cells during regenerative healing.  Now, the necessary genetic tools to map regenerative pathways are becoming available for the axolotl salamander, thus allowing comparative studies between scarring and regeneration.  Here, we describe in detail three methods to produce axolotl hematopoietic cell-tagged chimeras for the study of hematopoiesis and regeneration.

  5. Transferring morality to human-nonhuman chimeras.

    Science.gov (United States)

    Piotrowska, Monika

    2014-01-01

    Human-nonhuman chimeras have been the focus of ethical controversies for more than a decade, yet some related issues remain unaddressed. For example, little has been said about the relationship between the origin of transferred cells and the morally relevant capacities to which they may give rise. Consider, for example, a developing mouse fetus that receives a brain stem cell transplant from a human and another that receives a brain stem cell transplant from a dolphin. If both chimeras acquire morally relevant capacities as a result of transplantation, and if those capacities are indistinguishable, should the difference in cell origin matter to how we classify these creatures? I argue that if morally relevant capacities are easy to detect, cell origin is irrelevant to how the chimera ought to be treated. However, if such capacities are hard to detect, cell origin should play a role in considerations about how to treat the chimera.

  6. HIRENASD Chimera medium-size grid

    Data.gov (United States)

    National Aeronautics and Space Administration — Chimera medium-size grid for HIRENASD. Two files, fort.501 for grid for wing, fuselage, and 'world' zones, fort.503 for collar zone. File format is plot3d,...

  7. Allogeneic radiation chimeras induced in SPF mice

    International Nuclear Information System (INIS)

    During the past two decades much has been learned concerning the immunobiology of bone marrow chimeras induced in experimental animals as well as in man. However, from the basic as well as clinical points of view, there still remain many unsolved questions yet to be resolved. In this presentation, we discussed some of our recent results on the immunobiology of radiation chimeras induced in specific-pathogen-free (SPF) mice. These included the following: (a) contribution of graft versus host reaction (GVHR) as well non- GVHR mediated immunologic mechanism(s) to the expression of immunologic dysfunctions observed in allogeneic and certain semiallogeneic chimeras, (b) existence of immunoregulatory mechanism as a basis for the apparent lack of immunologic reactivity (tolerance) to the host- as well as to the donor-type alloantigens in situ in successful allogeneic bone marrow chimeras, and (c) the effect of microflora of the environment on the stability of such immunoregulatory mechanisms and its possible mechanism of action. (auth.)

  8. Chimera States in Mechanical Oscillator Networks

    CERN Document Server

    Martens, Erik Andreas; Fourrière, Antoine; Hallatschek, Oskar

    2013-01-01

    The synchronization of coupled oscillators is a fascinating manifestation of self-organization that nature employs to orchestrate essential processes of life, such as the beating of the heart. While it was long thought that synchrony or disorder were mutually exclusive steady states for a network of identical oscillators, numerous theoretical studies in recent years revealed the intriguing possibility of 'chimera states', in which the symmetry of the oscillator population is broken into a synchronous and an asynchronous part. However, a striking lack of empirical evidence raises the question of whether chimeras are indeed characteristic to natural systems. This calls for a palpable realization of chimera states without any fine-tuning, from which physical mechanisms underlying their emergence can be uncovered. Here, we devise a simple experiment with mechanical oscillators coupled in a hierarchical network to show that chimeras emerge naturally from a competition between two antagonistic synchronization patte...

  9. A classification scheme for chimera states

    OpenAIRE

    Kemeth, Felix P.; Haugland, Sindre W.; Schmidt, Lennart; Kevrekidis, Ioannis G.; Krischer, Katharina

    2016-01-01

    We present a universal characterization scheme for chimera states applicable to both numerical and experimental data sets. The scheme is based on two correlation measures that enable a meaningful definition of chimera states as well as their classification into three categories: stationary, turbulent and breathing. In addition, these categories can be further subdivided according to the time-stationarity of these two measures. We demonstrate that this approach both is consistent with previous...

  10. Chimeras in networks with purely local coupling

    OpenAIRE

    Laing, Carlo R.

    2015-01-01

    Chimera states in spatially extended networks of oscillators have some oscillators synchronised while the remainder are asynchronous. These states have primarily been studied in networks with nonlocal coupling, and more recently in networks with global coupling. Here we present three networks with only local coupling (diffusive, to nearest neighbours) which are numerically found to support chimera states. One of the networks is analysed using a self-consistency argument in the continuum limit...

  11. Chimera Death: Symmetry Breaking in Dynamical Networks

    OpenAIRE

    Zakharova, Anna; Kapeller, Marie; Schöll, Eckehard

    2014-01-01

    For a network of generic oscillators with nonlocal topology and symmetry-breaking coupling we establish novel partially coherent inhomogeneous spatial patterns, which combine the features of chimera states (coexisting incongruous coherent and incoherent domains) and oscillation death (oscillation suppression), which we call chimera death. We show that due to the interplay of nonlocality and breaking of rotational symmetry by the coupling two distinct scenarios from oscillatory behavior to a s...

  12. Preparation and properties of thin films used in activity determinations with a 4 {pi} counter; Preparation et proprietes des films minces utilises dans les determinations d'activite au compteur 4 {pi}

    Energy Technology Data Exchange (ETDEWEB)

    Jannez, M.; Le Gallic, Y.; Thenard, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Comparative study of various methods of preparing thin films, for use as source holders in the 4 {pi} counter, and of measuring their thickness. Comparative study of various properties: mechanical resistance; heat resistance; ageing; resistance of rhodopas, polystyrene, formvar and cellulose acetate films to the action of various chemical agents. (author) [French] Etude comparee de divers procedes de preparation de films minces, destines a etre utilises comme supports de sources dans le compteur 4 {pi} et de la mesure de leur epaisseur. Etude comparee de diverses proprietes: resistance mecanique; resistance a la chaleur; vieillissement; resistance a l'action de divers agents chimiques de films de rhodopas, polystyrene, formvar et acetate de cellulose. (auteur)

  13. Study of a 4{pi}{beta}-{gamma} coincidence system for absolute radionuclide activity measurement using plastic scintillators; Estudo de um sistema de coincidencias 4{pi}{beta}-{gamma} para a medida absoluta de atividade de radionuclideos empregando cintiladores plasticos

    Energy Technology Data Exchange (ETDEWEB)

    Piuvezam Filho, Helio

    2007-07-01

    The present work was intended to study a coincidence system 4{pi}(PS){beta}-{gamma} for absolute activity measurement using plastic scintillators in 4{pi} geometry. Along with experiments on the coincidence system, simulations were also performed applying the Monte Carlo Method, by means of codes PENELOPE and ESQUEMA. These simulations were performed in order to calculate the extrapolation curve of the coincidence system 4{pi}(PS){beta}-{gamma} and compare it to experimental data. A new geometry was proposed to the coincidence system adding up a second photomultiplier tube to the previous system for improving light collection from the plastic scintillator, as this system presented limitations in the minimum detected energy due to the presence of electronic noise and low gain. The results show that an improvement in the signal-to-noise ratio was obtained, as well as in the minimum detected energy. Moreover, there was an increase in the detection efficiency. With these modifications, it is now possible to calibrate radionuclides which emit low energy electrons or X-rays, increasing the number of radionuclides that can be standardized with this type of system.(author)

  14. Primary 4{pi}{beta}-{gamma} coincidence system for standardization of radionuclides by means of plastic scintillators; Sistema primario por coincidencias 4{pi}{beta}-{gamma} para a padronizacao de radionuclideos empregando cintiladores plasticos

    Energy Technology Data Exchange (ETDEWEB)

    Baccarelli, Aida Maria

    2003-07-01

    The present work describes a 4{pi}({alpha},{beta})-{gamma} coincidence system for absolute measurement of radionuclide activity using a plastic scintillator in 4{pi} geometry for charged particles detection and a Nal (Tl) crystal for gamma-ray detection. Several shapes and dimensions of the plastic scintillator have been tried in order to obtain the best system configuration. Radionuclides which decay by alpha emission, {beta}{sup -}, {beta}{sup +} and electron capture have been standardized. The results showed excellent agreement with other conventional primary system which makes use of a 4{pi} proportional counter for X-ray and charged particle detection. The system developed in the present work have some advantages when compared with the conventional systems, namely; it does not need metal coating on the films used as radioactive source holders. When compared to liquid scintillators, is showed the advantage of not needing to be kept in dark for more than 24 h to allow phosphorescence decay of ambient light. Therefore it can be set to count immediately after the sources are placed inside of it. (author)

  15. Imperfect traveling chimera states induced by local synaptic gradient coupling.

    Science.gov (United States)

    Bera, Bidesh K; Ghosh, Dibakar; Banerjee, Tanmoy

    2016-07-01

    In this paper, we report the occurrence of chimera patterns in a network of neuronal oscillators, which are coupled through local, synaptic gradient coupling. We discover a new chimera pattern, namely the imperfect traveling chimera state, where the incoherent traveling domain spreads into the coherent domain of the network. Remarkably, we also find that chimera states arise even for one-way local coupling, which is in contrast to the earlier belief that only nonlocal, global, or nearest-neighbor local coupling can give rise to chimera state; this find further relaxes the essential connectivity requirement of getting a chimera state. We choose a network of identical bursting Hindmarsh-Rose neuronal oscillators, and we show that depending upon the relative strength of the synaptic and gradient coupling, several chimera patterns emerge. We map all the spatiotemporal behaviors in parameter space and identify the transitions among several chimera patterns, an in-phase synchronized state, and a global amplitude death state. PMID:27575131

  16. Imperfect traveling chimera states induced by local synaptic gradient coupling

    Science.gov (United States)

    Bera, Bidesh K.; Ghosh, Dibakar; Banerjee, Tanmoy

    2016-07-01

    In this paper, we report the occurrence of chimera patterns in a network of neuronal oscillators, which are coupled through local, synaptic gradient coupling. We discover a new chimera pattern, namely the imperfect traveling chimera state, where the incoherent traveling domain spreads into the coherent domain of the network. Remarkably, we also find that chimera states arise even for one-way local coupling, which is in contrast to the earlier belief that only nonlocal, global, or nearest-neighbor local coupling can give rise to chimera state; this find further relaxes the essential connectivity requirement of getting a chimera state. We choose a network of identical bursting Hindmarsh-Rose neuronal oscillators, and we show that depending upon the relative strength of the synaptic and gradient coupling, several chimera patterns emerge. We map all the spatiotemporal behaviors in parameter space and identify the transitions among several chimera patterns, an in-phase synchronized state, and a global amplitude death state.

  17. Preliminary study for the detection of neutrons in heavy-ion collisions with charged particle detectors

    OpenAIRE

    Auditore L.; Pagano A.; Russotto P.

    2015-01-01

    At Laboratori Nazionali del Sud (LNS) the CHIMERA 4π multidetector has been designed and setup to detect charged particles emitted in heavy ion collisions at intermediate energies. Properties and performances of CHIMERA have been widely demonstrated by published results obtained in the performed experiments. Moreover, in recent years, a new charged particle detector (ChPD) for correlation studies (FARCOS) has been designed, and recently a first prototype has been coupled to CHIMERA, in order ...

  18. Chimera states on the surface of a sphere

    OpenAIRE

    Panaggio, Mark J; Abrams, Daniel M.

    2014-01-01

    A chimera state is a spatiotemporal pattern in which a network of identical coupled oscillators exhibits coexisting regions of asynchronous and synchronous oscillation. Two distinct classes of chimera states have been shown to exist: "spots" and "spirals." Here we study coupled oscillators on the surface of a sphere, a single system in which both spot and spiral chimera states appear. We present an analysis of the birth and death of spiral chimera states and show that although they coexist wi...

  19. Imperfect traveling chimera states induced by local synaptic gradient coupling

    OpenAIRE

    Bera, Bidesh K.; Ghosh, Dibakar; Banerjee, Tanmoy

    2016-01-01

    In this paper we report the occurrence of chimera patterns in a network of neuronal oscillators, which are coupled through {\\it local}, synaptic {\\it gradient} coupling. We discover a new chimera pattern, namely the {\\it imperfect traveling chimera} where the incoherent traveling domain spreads into the coherent domain of the network. Remarkably, we also find that chimera states arise even for {\\it one-way} local coupling, which is in contrast to the earlier belief that only nonlocal, global ...

  20. Chimera states: The natural link between coherence and incoherence

    OpenAIRE

    Omel'chenko, O.; Maistrenko, Yu.; Tass, P. A.

    2008-01-01

    Chimera states are remarkable spatiotemporal patterns in which coherence coexists with incoherence. As yet, chimera states have been considered as nongeneric, since they emerge only for particular initial conditions. In contrast, we show here that in a network of globally coupled oscillators delayed feedback stimulation with realistic (i.e., spatially decaying) stimulation profile generically induces chimera states. Intriguingly, a bifurcation analysis reveals that these chimera states are th...

  1. Persistent chimera states in nonlocally coupled phase oscillators

    OpenAIRE

    Suda, Yusuke; Okuda, Koji

    2015-01-01

    Chimera states in the systems of nonlocally coupled phase oscillators are considered stable in the continuous limit of spatially distributed oscillators. However, it is reported that in the numerical simulations without taking such limit, chimera states are chaotic transient and finally collapse into the completely synchronous solution. In this paper, we numerically study chimera states by using the coupling function different from the previous studies and obtain the result that chimera state...

  2. Antibody responses in allogeneic radiation chimeras

    International Nuclear Information System (INIS)

    The construction of long-lived allogeneic radiation chimeras, free of graft-versus-host disease, has been achieved using serologic elimination of Thy 1+ cells from donor bone marrow. Humoral immune function was not restored in these animals as evidenced by lack of primary antibody responses to a T cell-dependent antigen, namely, sheep erythrocytes (SRBC) both in vivo and in vitro. No evidence for a suppressor cell-mediated mechanism was found. Using separated chimera spleen cell populations and specific helper cell soluble mediators, the functional capabilities of chimera B cells, T cells, and macrophages were assessed. These findings suggested that the failure of chimeras to produce antibody is not the result of impaired B cell, T cell, or macrophage function, but rather, that it is due to ineffective cellular interactions. Physiologic cellular interactions depend upon the sharing of major histocompatibility complex (MHC) determinants between interacting cells. However, the self-recognition repertoire of developing T cells may be influenced by the environment which these cells differentiate such that they learn to recognize host MHC determinants as self. These findings support the interpretation that the immunologic hyporeactivity of allogeneic bone marrow chimeras reflects the role of the host environment in restricting the interactive capabilities of donor-derived cells

  3. Chimera states in mechanical oscillator networks.

    Science.gov (United States)

    Martens, Erik Andreas; Thutupalli, Shashi; Fourrière, Antoine; Hallatschek, Oskar

    2013-06-25

    The synchronization of coupled oscillators is a fascinating manifestation of self-organization that nature uses to orchestrate essential processes of life, such as the beating of the heart. Although it was long thought that synchrony and disorder were mutually exclusive steady states for a network of identical oscillators, numerous theoretical studies in recent years have revealed the intriguing possibility of "chimera states," in which the symmetry of the oscillator population is broken into a synchronous part and an asynchronous part. However, a striking lack of empirical evidence raises the question of whether chimeras are indeed characteristic of natural systems. This calls for a palpable realization of chimera states without any fine-tuning, from which physical mechanisms underlying their emergence can be uncovered. Here, we devise a simple experiment with mechanical oscillators coupled in a hierarchical network to show that chimeras emerge naturally from a competition between two antagonistic synchronization patterns. We identify a wide spectrum of complex states, encompassing and extending the set of previously described chimeras. Our mathematical model shows that the self-organization observed in our experiments is controlled by elementary dynamical equations from mechanics that are ubiquitous in many natural and technological systems. The symmetry-breaking mechanism revealed by our experiments may thus be prevalent in systems exhibiting collective behavior, such as power grids, optomechanical crystals, or cells communicating via quorum sensing in microbial populations.

  4. Present status of the Chimera-Isospin experiment

    International Nuclear Information System (INIS)

    The CHIMERA detector was designed to significantly contribute to multifragmentation studies in the field of heavy ion collisions at intermediate energies. The device has been used at 'Laboratori Nazionali del Sud' (LNS) in Catania (Italy) to study different aspects of the relevant nuclear reaction mechanism, in two different campaigns: the first one in 2000, by using the forward part (1 - 30 degrees) of the device, and the second one in 2003, by using the 4π geometry. The experimental results have confirmed the capability of the apparatus for good isotopic identification of light charged particles and light fragments (3< Z<10) in a wide angular detection range. The data analysis relative to the first 2000 campaign (REVERSE) is presently aimed to disentangle dynamical and equilibrium emission components in multifragmentation reactions and to learn more about the role of the isospin degree of freedom in asymmetric nuclear matter. Reduction of the data of the second campaign is still in progress. (authors)

  5. Turbulent chimeras in large semiconductor laser arrays

    CERN Document Server

    Shena, Joniald; Kovanis, Vassilios; Tsironis, George P

    2016-01-01

    Semiconductor laser arrays have been investigated experimentally and theoretically from the viewpoint of temporal and spatial coherence for the past forty years. In this work, we are focusing on a rather novel complex collective behavior, namely chimera states, where synchronized clusters of emitters coexist with unsynchronized ones. For the first time, we find such states exist in large diode arrays based on quantum well gain media with nearest-neighbor interactions. The crucial parameters are the evanescent coupling strength and the relative optical frequency detuning between the emitters of the array. By employing a recently proposed figure of merit for classifying chimera states, we provide quantitative and qualitative evidence for the observed dynamics. The corresponding chimeras are identified as turbulent according to the irregular temporal behavior of the classification measure. Such studies may be the springboard for designing next generation photonic emitters providing on demand diverse waveforms.

  6. Basins of attraction for chimera states

    Science.gov (United States)

    Martens, Erik A.; Panaggio, Mark J.; Abrams, Daniel M.

    2016-02-01

    Chimera states—curious symmetry-broken states in systems of identical coupled oscillators—typically occur only for certain initial conditions. Here we analyze their basins of attraction in a simple system comprised of two populations. Using perturbative analysis and numerical simulation we evaluate asymptotic states and associated destination maps, and demonstrate that basins form a complex twisting structure in phase space. Understanding the basins’ precise nature may help in the development of control methods to switch between chimera patterns, with possible technological and neural system applications.

  7. Chimera states: limits and open questions

    Science.gov (United States)

    Abrams, Daniel; Panaggio, Mark

    2015-03-01

    ``Chimera states'' are surprising patterns that can be found in systems of identical coupled oscillators, where synchrony and incoherence seem to stably coexist in a spatially asymmetrical state. The existence and stability of chimera states in a variety of settings relevant to real-world systems remains an active topic of research. Here I summarize what is known and present preliminary results for interesting limits including small and large-N, small and large coupling lag, as well as near-local and near-global coupling.

  8. α-Peptide/ß-Peptoid Chimeras

    DEFF Research Database (Denmark)

    Olsen, Christian Adam; Bonke, Gitte; Vedel, Line;

    2007-01-01

    We describe the synthesis and characterization of the first generation of oligomers consisting of alternating repeats of a-amino acids and chiral N-alkyl-ß-alanine (ß-peptoid) residues. These chimeras are stable toward proteolysis, non-hemolytic, and possess antibacterial activity comparable to...... well-known antimicrobial agents. Moreover, the chimeras exhibit length-dependent, concentration-dependent, solvent-dependent, and ion-strength-dependent ellipticity, indicating the presence of a secondary structure in solution. Thus, a-peptide/ß-peptoid oligomers represent a promising novel...

  9. Basins of Attraction for Chimera States

    DEFF Research Database (Denmark)

    Martens, Erik Andreas; Panaggio, Mark; Abrams, Daniel

    2016-01-01

    Chimera states---curious symmetry-broken states in systems of identical coupled oscillators---typically occur only for certain initial conditions. Here we analyze their basins of attraction in a simple system comprised of two populations. Using perturbative analysis and numerical simulation we...... evaluate asymptotic states and associated destination maps, and demonstrate that basins form a complex twisting structure in phase space. Understanding the basins' precise nature may help in the development of control methods to switch between chimera patterns, with possible technological and neural system...

  10. Chimera states in mechanical oscillator networks

    DEFF Research Database (Denmark)

    Martens, Erik Andreas; Thutupalli, Shashi; Fourrière, Antoine;

    2013-01-01

    of whether chimeras are indeed characteristic of natural systems. This calls for a palpable realization of chimera states without any fine-tuning, from which physical mechanisms underlying their emergence can be uncovered. Here, we devise a simple experiment with mechanical oscillators coupled...... in our experiments is controlled by elementary dynamical equations from mechanics that are ubiquitous in many natural and technological systems. The symmetry-breaking mechanism revealed by our experiments may thus be prevalent in systems exhibiting collective behavior, such as power grids, optomechanical...

  11. Persistent chimera states in nonlocally coupled phase oscillators

    Science.gov (United States)

    Suda, Yusuke; Okuda, Koji

    2015-12-01

    Chimera states in the systems of nonlocally coupled phase oscillators are considered stable in the continuous limit of spatially distributed oscillators. However, it is reported that in the numerical simulations without taking such limit, chimera states are chaotic transient and finally collapse into the completely synchronous solution. In this Rapid Communication, we numerically study chimera states by using the coupling function different from the previous studies and obtain the result that chimera states can be stable even without taking the continuous limit, which we call the persistent chimera state.

  12. Persistent chimera states in nonlocally coupled phase oscillators.

    Science.gov (United States)

    Suda, Yusuke; Okuda, Koji

    2015-12-01

    Chimera states in the systems of nonlocally coupled phase oscillators are considered stable in the continuous limit of spatially distributed oscillators. However, it is reported that in the numerical simulations without taking such limit, chimera states are chaotic transient and finally collapse into the completely synchronous solution. In this Rapid Communication, we numerically study chimera states by using the coupling function different from the previous studies and obtain the result that chimera states can be stable even without taking the continuous limit, which we call the persistent chimera state.

  13. Chimera states on the surface of a sphere.

    Science.gov (United States)

    Panaggio, Mark J; Abrams, Daniel M

    2015-02-01

    A chimera state is a spatiotemporal pattern in which a network of identical coupled oscillators exhibits coexisting regions of asynchronous and synchronous oscillation. Two distinct classes of chimera states have been shown to exist: "spots" and "spirals." Here we study coupled oscillators on the surface of a sphere, a single system in which both spot and spiral chimera states appear. We present an analysis of the birth and death of spiral chimera states and show that although they coexist with spot chimeras, they are stable in disjoint regions of parameter space.

  14. Recent actinide nuclear data efforts with the DANCE 4{pi} BaF{sub 2} array

    Energy Technology Data Exchange (ETDEWEB)

    Bredeweg, T.A.; Bond, E.M.; Couture, A.J.; Fitzpatrick, J.R.; Haight, R.C.; Hill, T.S.; Jandel, M.; O' Donnell, J.M.; Reifarth, R.; Rundberg, R.S.; Slemmons, A.K.; Tovesson, F.K.; Ullmann, J.L.; Vieira, D.J.; Wilhelmy, J.B.; Fowler, M.M.; Wouters, J.M. [Los Alamos National Laboratory, Los Alamos, NM (United States); Agvaanluvsan, U.; Becker, J.A.; Macri, R.A.; Parker, W.E.; Wilk, P.A.; Wu, C.Y. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Ethvignot, T.; Granier, T. [CEA Bruyeres-le-Chatel, 91 (France)

    2008-07-01

    Much of the recent work in the DANCE collaboration has focused on nuclides of interest to stockpile stewardship, attribution science and the advanced fuel cycle initiative. As an example, we have recently begun a program to produce high precision measurements of the key production and destruction reactions of important nuclear fuel elements and radiochemical diagnostic isotopes. The neutron capture targets that have been fielded under this program include several isotopes of uranium, plutonium and americium. However, neutron capture measurements on many of the actinides are complicated by the presence of {gamma}-rays arising from low energy neutron-induced fission. To overcome this difficulty we have designed and implemented a dual parallel-plate avalanche counter fission-tagging detector. This design provides a high efficiency for detecting fission fragments and is self-contained to allow loading of pre-assembled target/detector assemblies into the neutron beam line at DANCE. Neutron capture measurements have been performed on {sup 234,235,236}U. The results for {sup 236}U are consistent with the Endf/B-6 evaluation while the results for {sup 234}U are as much as 20% lower than the Endf/B-6 evaluation in the keV region. The DANCE results for {sup 234}U(n,{gamma}) have been incorporated into the Endf/B-7 evaluation. Planned measurements on {sup 238,239}Pu are also discussed.

  15. Basins of Attraction for Chimera States

    DEFF Research Database (Denmark)

    Martens, Erik Andreas; Panaggio, Mark; Abrams, Daniel

    2016-01-01

    Chimera states---curious symmetry-broken states in systems of identical coupled oscillators---typically occur only for certain initial conditions. Here we analyze their basins of attraction in a simple system comprised of two populations. Using perturbative analysis and numerical simulation we...

  16. CHIMERA Multidetector at Laboratori Nazionali del Sud

    International Nuclear Information System (INIS)

    The installation of CHIMERA multidetector, designed in order to study central collisions in heavy ion reactions at intermediate energy, is going on at LNS and the first experiment with the forward part (688 telescopes) is running since May 1999. The aim of this contribution is to present the status of the project

  17. 4{\\pi}{\\beta} (LS)-{\\gamma} (HPGe) Digital Coincidence System Based on Synchronous High-Speed Multichannel Data Acquisition

    CERN Document Server

    Chen, Jifeng; Liang, Juncheng; Liu, Jiacheng

    2015-01-01

    A dedicated 4{\\pi}{\\beta} (LS)-{\\gamma} (HPGe)digital coincidence system has been developed in this work, which includes five acquisition channels. Three analog-to-digital converter (ADC) acquisition channels with an acquisition resolution of 8 bits and acquisition rate of 1GSPS (sample per second) are utilized to collect the signals from three Photo multiplier tubes (PMTs) which are adopted to detect {\\beta} decay, and two acquisition channels with an acquisition resolution of 16 bits and acquisition rate of 50MSPS are utilized to collect the signals from high-purity germanium (HPGe) which are adopted to detect {\\gamma} decay. In order to increase the accuracy of the coincidence system, all the five acquisition channels are synchronous within 500ps. The data collected by the five acquisition channels will be transmitted to the host PC through PCI bus and saved as a file. Off-line software is applied for the 4{\\pi}{\\beta} (LS)-{\\gamma} (HPGe) coincidence and data analysis as needed in practical application. W...

  18. Clustered chimera states in systems of type-I excitability

    International Nuclear Information System (INIS)

    The chimera state is a fascinating phenomenon of coexisting synchronized and desynchronized behaviour that was discovered in networks of nonlocally coupled identical phase oscillators over ten years ago. Since then, chimeras have been found in numerous theoretical and experimental studies and more recently in models of neuronal dynamics as well. In this work, we consider a generic model for a saddle-node bifurcation on a limit cycle representative of neural excitability type I. We obtain chimera states with multiple coherent regions (clustered chimeras/multi-chimeras) depending on the distance from the excitability threshold, the range of nonlocal coupling and the coupling strength. A detailed stability diagram for these chimera states and other interesting coexisting patterns (like traveling waves) is presented. (paper)

  19. Weak chimeras in minimal networks of coupled phase oscillators

    OpenAIRE

    Ashwin, Peter; Burylko, Oleksandr

    2014-01-01

    We suggest a definition for a type of chimera state that appears in networks of indistinguishable phase oscillators. Defining a "weak chimera" as a type of invariant set showing partial frequency synchronization, we show that this means they cannot appear in phase oscillator networks that are either globally coupled or too small. We exhibit various networks of four, six and ten indistinguishable oscillators where weak chimeras exist with various dynamics and stabilities. We examine the role o...

  20. Chimera Ising Walls in Forced Nonlocally Coupled Oscillators

    OpenAIRE

    Kawamura, Yoji

    2007-01-01

    Nonlocally coupled oscillator systems can exhibit an exotic spatiotemporal structure called chimera, where the system splits into two groups of oscillators with sharp boundaries, one of which is phase-locked and the other is phase-randomized. Two examples of the chimera states are known: the first one appears in a ring of phase oscillators, and the second one is associated with the two-dimensional rotating spiral waves. In this article, we report yet another example of the chimera state that ...

  1. Self-Emerging and Turbulent Chimeras in Oscillator Chains

    OpenAIRE

    Bordyugov, G.; Pikovsky, A.; Rosenblum, M.

    2010-01-01

    We report on a self-emerging chimera state in a homogeneous chain of nonlocally and nonlinearly coupled oscillators. This chimera, i.e. a state with coexisting regions of complete and partial synchrony, emerges via a supercritical bifurcation from a homogeneous state and thus does not require preparation of special initial conditions. We develop a theory of chimera basing on the equations for the local complex order parameter in the Ott-Antonsen approximation. Applying a numerical linear stab...

  2. Nonspecific suppressor elements in murine allogeneic radiation chimeras

    International Nuclear Information System (INIS)

    Spleen cells from long-term mouse allogeneic radiation chimeras were tested for their ability to modulate the graft-versus-host (GVH) or plaque-forming cell (PFC) response of normal lymphocytes transplanted in lethally x-irradiated recipients. In vivo GVH proliferation of normal lymphocytes (syngeneic to donor cells of the chimera) against antigens of host-type in which the chimeric state had been established was reduced by chimera cells. Inhibition varied, some chimeras suppressing GVH more than others and a few not suppressing at all. The suppressive effect was abrogated if the chimera cells were treated with anti-THETA; treatment with anti-IgM did not eliminate this activity. When mixtures of normal donor lymphocytes and chimera cells were given to irradiated recipients genetically different from host or donor, reduction of donor cell GVH also occurred. Further, chimera cells reduced the GVH activity of normal host cells in irradiated recipients differing from the host at one H-2 locus and from the donor at minor histocompatibility loci. The modulating effect of spleen cells from chimeras on the PFC response by normal lymphocytes also varied. Six chimeras induced a 25 to 90% suppression, two enhanced the response, and one showed no effect. Where suppression occurred, treatment of chimera cells with anti-THETA most often, but not always, restored PFC production. Our results show that the suppressive action of splenic lymphoid cells by chimeras is highly nonspecific and variable in expression. We suggest that tolerance in chimeras may be mediated by nonspecific suppressor elements leading to unresponsiveness to a variety of antigens including SRBC

  3. Chimera: a Bioconductor package for secondary analysis of fusion products.

    OpenAIRE

    Beccuti, Marco; Carrara, Matteo; Cordero, Francesca; Lazzarato, Fulvio; Donatelli, Susanna; Nadalin, Francesca; Policriti, Alberto; Calogero, Raffaele A.

    2014-01-01

    Summary: Chimera is a Bioconductor package that organizes, annotates, analyses and validates fusions reported by different fusion detection tools; current implementation can deal with output from bellerophontes, chimeraScan, deFuse, fusionCatcher, FusionFinder, FusionHunter, FusionMap, mapSplice, Rsubread, tophat-fusion and STAR. The core of Chimera is a fusion data structure that can store fusion events detected with any of the aforementioned tools. Fusions are then easily manipulated with s...

  4. Clustered Chimera States in Systems of Type-I Excitability

    OpenAIRE

    Vüllings, Andrea; Hizanidis, Johanne; Omelchenko, Iryna; Hövel, Philipp

    2014-01-01

    Chimera is a fascinating phenomenon of coexisting synchronized and desynchronized behaviour that was discovered in networks of nonlocally coupled identical phase oscillators over ten years ago. Since then, chimeras were found in numerous theoretical and experimental studies and more recently in models of neuronal dynamics as well. In this work, we consider a generic model for a saddle-node bifurcation on a limit cycle representative for neural excitability type I. We obtain chimera states wit...

  5. Chimera states in hierarchical networks of Van der Pol oscillators

    OpenAIRE

    Ulonska, Stefan; Omelchenko, Iryna; Zakharova, Anna; Schoell, Eckehard

    2016-01-01

    Chimera states are complex spatio-temporal patterns that consist of coexisting domains of coherent and incoherent dynamics. We analyse chimera states in networks of Van der Pol oscillators with hierarchical coupling topology. We investigate the stepwise transition from a nonlocal to a hierarchical topology, and propose the network clustering coefficient as a measure to establish a link between the existence of chimera states and the compactness of the initial base pattern of a hierarchical to...

  6. Application of Monte Carlo method in study of the padronization for radionuclides with complex disintegration scheme in 4{pi}{beta}-{gamma} coincidence System; Aplicacao do metodo de Monte Carlo no estudo da padronizacao de radionuclideos com esquema de desintegracao complexos em sistema de coincidencias 4{pi}{beta}-{gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Mauro Noriaki

    2006-07-01

    The present work described a new methodology for modelling the behaviour of the activity in a 4{pi}{beta}-{gamma} coincidence system. The detection efficiency for electrons in the proportional counter and gamma radiation in the NaI(Tl) detector was calculated using the Monte Carlo program MCNP4C. Another Monte Carlo code was developed which follows the path in the disintegration scheme from the initial state of the precursor radionuclide, until the ground state of the daughter nucleus. Every step of the disintegration scheme is sorted by random numbers taking into account the probabilities of all {beta}{sup -} branches, electronic capture branches, transitions probabilities and internal conversion coefficients. Once the final state was reached beta, electronic capture events and gamma transitions are accounted for the three spectra: beta, gamma and coincidence variation in the beta efficiency was performed simulating energy cut off or use of absorbers (Collodion). The selected radionuclides for simulation were: {sup 134}Cs, {sup 72}Ga which disintegrate by {beta}{sup -} transition, {sup 133}Ba which disintegrates by electronic capture and {sup 35}S which is a beta pure emitter. For the latter, the Efficiency Tracing technique was simulated. The extrapolation curves obtained by Monte Carlo were filled by the Least Square Method with the experimental points and the results were compared to the Linear Extrapolation method. (author)

  7. 4{pi} studies of the 1.8{endash}4.8 GeV {sup 3}He+{sup nat}Ag, {sup 197}Au reactions. II. Multifragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Renshaw Foxford, E.; Kwiatkowski, K.; Bracken, D.S.; Morley, K.B.; Viola, V.E.; Yoder, N.R. [Departments of Chemistry and Physics and Indiana University Cyclotron Facility, Indiana University, Bloomington, Indiana 47405 (United States); Volant, C.; Pollacco, E.C.; Legrain, R. [Commissariat a l`Energie Atomique, DAPNIA Service de Physique Nucleaire, C. E. Saclay, 91191 Gif-sur-Yvette, Cedex (France); Korteling, R.G. [Department of Chemistry, Simon Fraser University, Burnaby, British Columbia (Canada); Friedman, W.A. [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Brzychczyk, J. [Institute of Physics, Jagiellonian University, 30-059 Krakow (Poland); Breuer, H. [Department of Physics, University of Maryland, College Park, Maryland 20742 (United States)

    1996-08-01

    Multifragmentation of {sup nat}Ag and {sup 197}Au nuclei induced by 1.8{endash}4.8 GeV {sup 3}He ions has been studied with the Indiana Silicon Sphere 4{pi} detector array. Rapidity, moving source, and sphericity-coplanarity analyses are consistent with near-simultaneous emission from a source in approximate kinetic equilibrium. For the most dissipative collisions, the spectral peaks are broadened and shifted to very low energies, indicative of emission from an extended nuclear system with {rho}/{rho}{sub 0}{approximately}1/3. Predictions of an intranuclear cascade/expanding, emitting source model compare well with experimental multiplicity distributions and the evolution of fragment spectral shapes. {copyright} {ital 1996 The American Physical Society.}

  8. Intermittent chaotic chimeras for coupled rotators.

    Science.gov (United States)

    Olmi, Simona; Martens, Erik A; Thutupalli, Shashi; Torcini, Alessandro

    2015-09-01

    Two symmetrically coupled populations of N oscillators with inertia m display chaotic solutions with broken symmetry similar to experimental observations with mechanical pendulums. In particular, we report evidence of intermittent chaotic chimeras, where one population is synchronized and the other jumps erratically between laminar and turbulent phases. These states have finite lifetimes diverging as a power law with N and m. Lyapunov analyses reveal chaotic properties in quantitative agreement with theoretical predictions for globally coupled dissipative systems.

  9. Chimera states: The Existence Criteria Revisited

    OpenAIRE

    Sethia, Gautam C.; Sen, Abhijit

    2013-01-01

    Chimera states, representing a spontaneous break-up of a population of identical oscillators that are identically coupled, into sub-populations displaying synchronized and desynchronized behavior, have traditionally been found to exist in weakly coupled systems and with some form of nonlocal coupling between the oscillators. Here we show that neither the weak-coupling approximation nor nonlocal coupling are essential conditions for their existence. We obtain for the first time amplitude-media...

  10. A New Approximate Chimera Donor Cell Search Algorithm

    Science.gov (United States)

    Holst, Terry L.; Nixon, David (Technical Monitor)

    1998-01-01

    The objectives of this study were to develop chimera-based full potential methodology which is compatible with overflow (Euler/Navier-Stokes) chimera flow solver and to develop a fast donor cell search algorithm that is compatible with the chimera full potential approach. Results of this work included presenting a new donor cell search algorithm suitable for use with a chimera-based full potential solver. This algorithm was found to be extremely fast and simple producing donor cells as fast as 60,000 per second.

  11. Chimera states in spatiotemporal systems: Theory and Applications

    Science.gov (United States)

    Yao, Nan; Zheng, Zhigang

    2016-03-01

    In this paper, we propose a retrospective and summary on recent studies of chimera states. Chimera states demonstrate striking inhomogeneous spatiotemporal patterns emerging in homogeneous systems through unexpected spontaneous symmetry breaking, where the consequent spatiotemporal patterns are composed of both coherence and incoherence domains, respectively characterized by the synchronized and desynchronized motions of oscillators. Since the discovery of chimera states by Kuramoto and others, this striking collective behavior has attracted a great deal of research interest in the community of physics and related interdisciplinary fields from both theoretical and experimental viewpoints. In recent works exploring chimera states, rich phenomena such as the spiral wave chimera, multiple cluster chimera, amplitude chimera were observed from various types of model systems. Theoretical framework by means of self-consistency approach and Ott-Antonsen approach were proposed for further understanding to this symmetry-breaking-induced behavior. The stability and robustness of chimera states were also discussed. More importantly, experiments ranging from optical, chemical to mechanical designs successfully approve the existence of chimera states.

  12. Coherence-Resonance Chimeras in a Network of Excitable Elements

    Science.gov (United States)

    Semenova, Nadezhda; Zakharova, Anna; Anishchenko, Vadim; Schöll, Eckehard

    2016-07-01

    We demonstrate that chimera behavior can be observed in nonlocally coupled networks of excitable systems in the presence of noise. This phenomenon is distinct from classical chimeras, which occur in deterministic oscillatory systems, and it combines temporal features of coherence resonance, i.e., the constructive role of noise, and spatial properties of chimera states, i.e., the coexistence of spatially coherent and incoherent domains in a network of identical elements. Coherence-resonance chimeras are associated with alternating switching of the location of coherent and incoherent domains, which might be relevant in neuronal networks.

  13. Computing Flows Using Chimera and Unstructured Grids

    Science.gov (United States)

    Liou, Meng-Sing; Zheng, Yao

    2006-01-01

    DRAGONFLOW is a computer program that solves the Navier-Stokes equations of flows in complexly shaped three-dimensional regions discretized by use of a direct replacement of arbitrary grid overlapping by nonstructured (DRAGON) grid. A DRAGON grid (see figure) is a combination of a chimera grid (a composite of structured subgrids) and a collection of unstructured subgrids. DRAGONFLOW incorporates modified versions of two prior Navier-Stokes-equation-solving programs: OVERFLOW, which is designed to solve on chimera grids; and USM3D, which is used to solve on unstructured grids. A master module controls the invocation of individual modules in the libraries. At each time step of a simulated flow, DRAGONFLOW is invoked on the chimera portion of the DRAGON grid in alternation with USM3D, which is invoked on the unstructured subgrids of the DRAGON grid. The USM3D and OVERFLOW modules then immediately exchange their solutions and other data. As a result, USM3D and OVERFLOW are coupled seamlessly.

  14. Optimized 4 pi spherical shell depleted uranium-water shield weights for 200 to 550-megawatt reactors

    Science.gov (United States)

    Wohl, M. L.; Celnik, J.; Schamberger, R. D.

    1972-01-01

    Optimization calculations to determine minimum 4 pi spherical-shell weights were performed at 200-, 375-, and 550-megawatt-thermal reactor power levels. Monte Carlo analyses were performed for a reactor power level corresponding to 375 megawatts. Power densities for the spherical reactor model used varied from 64.2 to 256 watts per cubic centimeter. The dose rate constraint in the optimization calculations was 0.25 mrem per hour at 9.14 meters from the reactor center. The resulting shield weights were correlated with the reactor power levels and power densities by a regression analysis. The optimum shield weight for a 375-megawatt, 160-watt-per-cubic-centimeter reactor was 202,000 kilograms.

  15. Mean-field-diffusion-induced chimera death state

    Science.gov (United States)

    Banerjee, Tanmoy

    2015-06-01

    Recently a novel dynamical state, called the chimera death, has been discovered in a network of nonlocally coupled identical oscillators (Zakharova A., Kapeller M. and Schöll E., Phys. Rev. Lett., 112 (2014) 154101), which is defined as the coexistence of spatially coherent and incoherent oscillation death state. This state arises due to the interplay of nonlocality and symmetry breaking and thus it bridges the gap between two important dynamical states, namely the chimera and oscillation death. In this paper we show that the chimera death can be induced in a network of generic identical oscillators with mean-field diffusive coupling and thus we establish that a nonlocal coupling is not essential to obtain chimera death. We identify a new transition route to the chimera death state, namely the transition from in-phase synchronized oscillation to chimera death via global amplitude death state. We ascribe the occurrence of chimera death to the bifurcation structure of the network in the limiting condition and show that multi-cluster chimera death states can be achieved by a proper choice of initial conditions.

  16. Metaphysical and ethical perspectives on creating animal-human chimeras.

    Science.gov (United States)

    Eberl, Jason T; Ballard, Rebecca A

    2009-10-01

    This paper addresses several questions related to the nature, production, and use of animal-human (a-h) chimeras. At the heart of the issue is whether certain types of a-h chimeras should be brought into existence, and, if they are, how we should treat such creatures. In our current research environment, we recognize a dichotomy between research involving nonhuman animal subjects and research involving human subjects, and the classification of a research protocol into one of these categories will trigger different ethical standards as to the moral permissibility of the research in question. Are a-h chimeras entitled to the more restrictive and protective ethical standards applied to human research subjects? We elucidate an Aristotelian-Thomistic metaphysical framework in which to argue how such chimeras ought to be defined ontologically. We then examine when the creation of, and experimentation upon, certain types of a-h chimeras may be morally permissible.

  17. Implementing real-time robotic systems using CHIMERA II

    Science.gov (United States)

    Stewart, David B.; Schmitz, Donald E.; Khosla, Pradeep K.

    1990-01-01

    A description is given of the CHIMERA II programming environment and operating system, which was developed for implementing real-time robotic systems. Sensor-based robotic systems contain both general- and special-purpose hardware, and thus the development of applications tends to be a time-consuming task. The CHIMERA II environment is designed to reduce the development time by providing a convenient software interface between the hardware and the user. CHIMERA II supports flexible hardware configurations which are based on one or more VME-backplanes. All communication across multiple processors is transparent to the user through an extensive set of interprocessor communication primitives. CHIMERA II also provides a high-performance real-time kernel which supports both deadline and highest-priority-first scheduling. The flexibility of CHIMERA II allows hierarchical models for robot control, such as NASREM, to be implemented with minimal programming time and effort.

  18. Spiral wave chimeras in locally coupled oscillator systems

    Science.gov (United States)

    Li, Bing-Wei; Dierckx, Hans

    2016-02-01

    The recently discovered chimera state involves the coexistence of synchronized and desynchronized states for a group of identical oscillators. In this work, we show the existence of (inwardly) rotating spiral wave chimeras in the three-component reaction-diffusion systems where each element is locally coupled by diffusion. A transition from spiral waves with the smooth core to spiral wave chimeras is found as we change the local dynamics of the system or as we gradually increase the diffusion coefficient of the activator. Our findings on the spiral wave chimera in the reaction-diffusion systems suggest that spiral chimera states may be found in chemical and biological systems that can be modeled by a large population of oscillators indirectly coupled via a diffusive environment.

  19. Nonlinearity of local dynamics promotes multi-chimeras.

    Science.gov (United States)

    Omelchenko, Iryna; Zakharova, Anna; Hövel, Philipp; Siebert, Julien; Schöll, Eckehard

    2015-08-01

    Chimera states are complex spatio-temporal patterns in which domains of synchronous and asynchronous dynamics coexist in coupled systems of oscillators. We examine how the character of the individual elements influences chimera states by studying networks of nonlocally coupled Van der Pol oscillators. Varying the bifurcation parameter of the Van der Pol system, we can interpolate between regular sinusoidal and strongly nonlinear relaxation oscillations and demonstrate that more pronounced nonlinearity induces multi-chimera states with multiple incoherent domains. We show that the stability regimes for multi-chimera states and the mean phase velocity profiles of the oscillators change significantly as the nonlinearity becomes stronger. Furthermore, we reveal the influence of time delay on chimera patterns.

  20. Spiral wave chimeras in locally coupled oscillator systems.

    Science.gov (United States)

    Li, Bing-Wei; Dierckx, Hans

    2016-02-01

    The recently discovered chimera state involves the coexistence of synchronized and desynchronized states for a group of identical oscillators. In this work, we show the existence of (inwardly) rotating spiral wave chimeras in the three-component reaction-diffusion systems where each element is locally coupled by diffusion. A transition from spiral waves with the smooth core to spiral wave chimeras is found as we change the local dynamics of the system or as we gradually increase the diffusion coefficient of the activator. Our findings on the spiral wave chimera in the reaction-diffusion systems suggest that spiral chimera states may be found in chemical and biological systems that can be modeled by a large population of oscillators indirectly coupled via a diffusive environment. PMID:26986275

  1. A 3-D chimera grid embedding technique

    Science.gov (United States)

    Benek, J. A.; Buning, P. G.; Steger, J. L.

    1985-01-01

    A three-dimensional (3-D) chimera grid-embedding technique is described. The technique simplifies the construction of computational grids about complex geometries. The method subdivides the physical domain into regions which can accommodate easily generated grids. Communication among the grids is accomplished by interpolation of the dependent variables at grid boundaries. The procedures for constructing the composite mesh and the associated data structures are described. The method is demonstrated by solution of the Euler equations for the transonic flow about a wing/body, wing/body/tail, and a configuration of three ellipsoidal bodies.

  2. 77 FR 65602 - Chimera Energy Corporation; Order of Suspension of Trading

    Science.gov (United States)

    2012-10-29

    ... COMMISSION Chimera Energy Corporation; Order of Suspension of Trading October 25, 2012. It appears to the... securities of Chimera Energy Corporation (``Chimera'') because of questions regarding the accuracy of statements by Chimera in press releases to investors concerning, among other things, the company's...

  3. Immunologic studies of canine bone marrow chimeras

    International Nuclear Information System (INIS)

    When prospective male or female recipients from the Cooperstown colony were exposed to supralethal total body irradiation and were reconstituted with bone marrow obtained from genotypically DL-A-identical littermate or nonlittermate donors such treatment resulted, in regularly reproducible fashion, in the establishment of a long-term state of chimerism with no evidence of graft-versus-host disease in any of the recipients. The resulting chimeras have survived thus far for 882-1466 days, with donor red cell antigen and leukocyte sex marker evidence of the persistence of chimerism. Subsequent challenge of the chimeras with renal and skin allografts obtained from the specific donor of marrow resulted in the long-term survival of such transplants without any evidence of rejection for 833--1402 days. Skin allografts obtained from other dogs were, however, accorded first-set rejection times. Recent studies indicate that the state of allogeneic unresponsiveness produced by supralethal total body irradiation and bone marrow transplantation also extends to other organs from the donor of marrow, including heart, liver, pancreas and duodenum, and lung

  4. Chimera states in purely local delay-coupled oscillators

    Science.gov (United States)

    Bera, Bidesh K.; Ghosh, Dibakar

    2016-05-01

    We study the existence of chimera states in a network of locally coupled chaotic and limit-cycle oscillators. The necessary condition for chimera state in purely local coupled oscillators is discussed. At first, we numerically observe the existence of chimera or multichimera states in the locally coupled Hindmarsh-Rose neuron model. We find that delay time in the nonlinear local coupling reduces the domain of the coherent island in the parameter space of the synaptic coupling strength and time delay, and thus the coherent region can be completely eliminated once the time delay exceeds a certain threshold. We then consider another form of nonlinearity in the local coupling, and the existence of chimera states is observed in the time-delayed Mackey-Glass system and in a Van der Pol oscillator. We also discuss the effect of time delay in local coupling for the existence of chimera states in Mackey-Glass systems. The nonlinearity present in the coupling function plays a key role in the emergence of chimera or multichimera states. A phase diagram for the chimera state is identified over a wide parameter space.

  5. Different kinds of chimera death states in nonlocally coupled oscillators

    Science.gov (United States)

    Premalatha, K.; Chandrasekar, V. K.; Senthilvelan, M.; Lakshmanan, M.

    2016-05-01

    We investigate the significance of nonisochronicity parameter in a network of nonlocally coupled Stuart-Landau oscillators with symmetry breaking form. We observe that the presence of nonisochronicity parameter leads to structural changes in the chimera death region while varying the strength of the interaction. This gives rise to the existence of different types of chimera death states such as multichimera death state, type I periodic chimera death (PCD) state, and type II periodic chimera death state. We also find that the number of periodic domains in both types of PCD states decreases exponentially with an increase of coupling range and obeys a power law under nonlocal coupling. Additionally, we also analyze the structural changes of chimera death states by reducing the system of dynamical equations to a phase model through the phase reduction. We also briefly study the role of nonisochronicity parameter on chimera states, where the existence of a multichimera state with respect to the coupling range is pointed out. Moreover, we also analyze the robustness of the chimera death state to perturbations in the natural frequencies of the oscillators.

  6. Multi-headed chimera states in coupled pendula

    Science.gov (United States)

    Jaros, P.; Borkowski, L.; Witkowski, B.; Czolczynski, K.; Kapitaniak, T.

    2015-07-01

    We discuss the occurrence of the chimera states in the network of coupled, excited by the clock's mechanisms pendula. We find the patterns of multi-headed chimera states in which pendula clustered in different heads behave differently (oscillate with different frequencies) and create different types of synchronous states (complete or phase synchronization). The mathematical model of the network shows that the observed chimera states are controlled by elementary dynamical equations derived from the Newton's laws that are ubiquitous in many physical and engineering systems.

  7. Fast clique minor generation in Chimera qubit connectivity graphs

    OpenAIRE

    Boothby, Tomas; King, Andrew D.; Roy, Aidan

    2015-01-01

    The current generation of D-Wave quantum annealing processor is designed to minimize the energy of an Ising spin configuration whose pairwise interactions lie on the edges of a {\\em Chimera} graph $\\mathcal C_{M,N,L}$. In order to solve an Ising spin problem with arbitrary pairwise interaction structure, the corresponding graph must be minor-embedded into a Chimera graph. We define a combinatorial class of {\\em native clique minors} in Chimera graphs with vertex images of uniform, near minima...

  8. Chimera states in coupled sine-circle map lattices

    OpenAIRE

    Nayak, Chitra R.; Gupte, Neelima

    2010-01-01

    Systems of coupled oscillators have been seen to exhibit chimera states, i.e. states where the system splits into two groups where one group is phase locked and the other is phase randomized. In this work, we report the existence of chimera states in a system of two interacting populations of sine circle maps. This system also exhibits the clustered chimera behavior seen earlier in delay coupled systems. Rich spatio-temporal behavior is seen in different regimes of the phase diagram.We carry ...

  9. Bistable Chimera Attractors on a Triangular Network of Oscillator Populations

    DEFF Research Database (Denmark)

    Martens, Erik Andreas

    2010-01-01

    We study a triangular network of three populations of coupled phase oscillators with identical frequencies. The populations interact nonlocally, in the sense that all oscillators are coupled to one another, but more weakly to those in neighboring populations than to those in their own population....... This triangular network is the simplest discretization of a continuous ring of oscillators. Yet it displays an unexpectedly different behavior: in contrast to the lone stable chimera observed in continuous rings of oscillators, we find that this system exhibits two coexisting stable chimeras. Both chimeras are...

  10. Grid adaptation using chimera composite overlapping meshes

    Science.gov (United States)

    Kao, Kai-Hsiung; Liou, Meng-Sing; Chow, Chuen-Yen

    1994-01-01

    The objective of this paper is to perform grid adaptation using composite overlapping meshes in regions of large gradient to accurately capture the salient features during computation. The chimera grid scheme, a multiple overset mesh technique, is used in combination with a Navier-Stokes solver. The numerical solution is first converged to a steady state based on an initial coarse mesh. Solution-adaptive enhancement is then performed by using a secondary fine grid system which oversets on top of the base grid in the high-gradient region, but without requiring the mesh boundaries to join in any special way. Communications through boundary interfaces between those separated grids are carried out using trilinear interpolation. Application to the Euler equations for shock reflections and to shock wave/boundary layer interaction problem are tested. With the present method, the salient features are well-resolved.

  11. Grid adaption using Chimera composite overlapping meshes

    Science.gov (United States)

    Kao, Kai-Hsiung; Liou, Meng-Sing; Chow, Chuen-Yen

    1993-01-01

    The objective of this paper is to perform grid adaptation using composite over-lapping meshes in regions of large gradient to capture the salient features accurately during computation. The Chimera grid scheme, a multiple overset mesh technique, is used in combination with a Navier-Stokes solver. The numerical solution is first converged to a steady state based on an initial coarse mesh. Solution-adaptive enhancement is then performed by using a secondary fine grid system which oversets on top of the base grid in the high-gradient region, but without requiring the mesh boundaries to join in any special way. Communications through boundary interfaces between those separated grids are carried out using tri-linear interpolation. Applications to the Euler equations for shock reflections and to a shock wave/boundary layer interaction problem are tested. With the present method, the salient features are well resolved.

  12. Solvable Model of Spiral Wave Chimeras

    DEFF Research Database (Denmark)

    Martens, Erik Andreas; Laing, Carlo R.; Strogatz, Steven H.

    2010-01-01

    Spiral waves are ubiquitous in two-dimensional systems of chemical or biological oscillators coupled locally by diffusion. At the center of such spirals is a phase singularity, a topological defect where the oscillator amplitude drops to zero. But if the coupling is nonlocal, a new kind of spiral...... can occur, with a circular core consisting of desynchronized oscillators running at full amplitude. Here, we provide the first analytical description of such a spiral wave chimera and use perturbation theory to calculate its rotation speed and the size of its incoherent core.......Spiral waves are ubiquitous in two-dimensional systems of chemical or biological oscillators coupled locally by diffusion. At the center of such spirals is a phase singularity, a topological defect where the oscillator amplitude drops to zero. But if the coupling is nonlocal, a new kind of spiral...

  13. Controlling chimera states: The influence of excitable units

    Science.gov (United States)

    Isele, Thomas; Hizanidis, Johanne; Provata, Astero; Hövel, Philipp

    2016-02-01

    We explore the influence of a block of excitable units on the existence and behavior of chimera states in a nonlocally coupled ring-network of FitzHugh-Nagumo elements. The FitzHugh-Nagumo system, a paradigmatic model in many fields from neuroscience to chemical pattern formation and nonlinear electronics, exhibits oscillatory or excitable behavior depending on the values of its parameters. Until now, chimera states have been studied in networks of coupled oscillatory FitzHugh-Nagumo elements. In the present work, we find that introducing a block of excitable units into the network may lead to several interesting effects. It allows for controlling the position of a chimera state as well as for generating a chimera state directly from the synchronous state.

  14. Fast clique minor generation in Chimera qubit connectivity graphs

    Science.gov (United States)

    Boothby, Tomas; King, Andrew D.; Roy, Aidan

    2016-01-01

    The current generation of D-Wave quantum annealing processor is designed to minimize the energy of an Ising spin configuration whose pairwise interactions lie on the edges of a Chimera graph C_{M,N,L}. In order to solve an Ising spin problem with arbitrary pairwise interaction structure, the corresponding graph must be minor-embedded into a Chimera graph. We define a combinatorial class of native clique minors in Chimera graphs with vertex images of uniform, near minimal size and provide a polynomial-time algorithm that finds a maximum native clique minor in a given induced subgraph of a Chimera graph. These minors allow improvement over recent work and have immediate practical applications in the field of quantum annealing.

  15. Chimera states and excitation waves in networks with complex topologies

    Science.gov (United States)

    Schöll, Eckehard

    2016-06-01

    Chimera patterns, which consist of coexisting spatial domains of coherent (synchronized) and incoherent (desyn- chronized) dynamics are studied in networks of FitzHugh-Nagumo systems with complex topologies. To test the robustness of chimera patterns with respect to changes in the structure of the network, we study the following network topologies: Regular ring topology with R nearest neigbors coupled to each side, small-world topology with additional long-range random links, and a hierarchical geometry in the connectivity matrix. We find that chimera states are generally robust with respect to these perturbations, but qualitative changes of the chimera patterns in form of nested coherent and incoherent regions can be induced by a hierarchical topology. The suppression of propagating excitation waves by a small-world topology is also reviewed.

  16. Clustered chimera states in delay coupled oscillator systems

    OpenAIRE

    Sethia, Gautam C.; Sen, Abhijit; Atay, Fatihcan M

    2008-01-01

    We investigate "chimera" states in a ring of identical phase oscillators coupled in a time-delayed and spatially non-local fashion. We find novel "clustered chimera" states that have spatially distributed phase coherence separated by incoherence with adjacent coherent regions in anti-phase. The existence of such time-delay induced phase clustering is further supported through solutions of a generalized functional self-consistency equation of the mean field. Our results highlight an additional...

  17. Chimera patterns in the Kuramoto-Battogtokh model

    OpenAIRE

    Smirnov, L.A.; Osipov, G. V.; Pikovsky, A.

    2016-01-01

    Kuramoto and Battogtokh [Nonlinear Phenom. Complex Syst. 5, 380 (2002)] discovered chimera states represented by stable coexisting synchrony and asynchrony domains in a lattice of coupled oscillators. After reformulation in terms of local order parameter, the problem can be reduced to partial differential equations. We find uniformly rotating periodic in space chimera patterns as solutions of a reversible ordinary differential equation, and demonstrate a plethora of such states. In the limit ...

  18. Robustness of chimera states in complex dynamical systems

    OpenAIRE

    Nan Yao; Zi-Gang Huang; Ying-Cheng Lai; Zhi-Gang Zheng

    2013-01-01

    The remarkable phenomenon of chimera state in systems of non-locally coupled, identical oscillators has attracted a great deal of recent theoretical and experimental interests. In such a state, different groups of oscillators can exhibit characteristically distinct types of dynamical behaviors, in spite of identity of the oscillators. But how robust are chimera states against random perturbations to the structure of the underlying network? We address this fundamental issue by studying the eff...

  19. Controlling Chimera States - The influence of excitable units

    OpenAIRE

    Isele, Thomas; Hizanidis, Johanne; Provata, Astero; Hövel, Philipp

    2015-01-01

    We explore the influence of a block of excitable units on the existence and behavior of chimera states in a nonlocally coupled ring-network of FitzHugh-Nagumo elements. The FitzHugh-Nagumo system, a paradigmatic model in many fields from neuroscience to chemical pattern formation and nonlinear electronics, exhibits oscillatory or excitable behavior depending on the values of its parameters. Until now, chimera states have been studied in networks of coupled oscillatory FitzHugh-Nagumo elements...

  20. Self-organized alternating chimera states in oscillatory media

    OpenAIRE

    Haugland, Sindre W.; Schmidt, Lennart; Krischer, Katharina

    2014-01-01

    Oscillatory media can exhibit the coexistence of synchronized and desynchronized regions, so-called chimera states, for uniform parameters and symmetrical coupling. In a phase-balanced chimera state, where the totals of synchronized and desynchronized regions, respectively, are of the same size, the symmetry of the system predicts that interchanging both phases still gives a solution to the underlying equations. We observe this kind of interchange as a self-emerging phenomenon in an oscillato...

  1. Chimera death induced by the mean-field diffusive coupling

    OpenAIRE

    Banerjee, Tanmoy

    2014-01-01

    Recently a novel dynamical state, called the {\\it chimera death}, is discovered in a network of non locally coupled identical oscillators [A. Zakharova, M. Kapeller, and E. Sch\\"oll, Phy.Rev.Lett. 112, 154101 (2014)], which is defined as the coexistence of spatially coherent and incoherent oscillation death state. This state arises due to the interplay of non locality and symmetry breaking and thus bridges the gap between two important dynamical states, namely the chimera and oscillation deat...

  2. Nonlinearity of local dynamics promotes multi-chimeras

    OpenAIRE

    Omelchenko, Iryna; Zakharova, Anna; Hoevel, Philipp; Siebert, Julien; Schoell, Eckehard

    2015-01-01

    Chimera states are complex spatio-temporal patterns in which domains of synchronous and asynchronous dynamics coexist in coupled systems of oscillators. We examine how the character of the individual elements influences chimera states by studying networks of nonlocally coupled Van der Pol oscillators. Varying the bifurcation parameter of the Van der Pol system, we can interpolate between regular sinusoidal and strongly nonlinear relaxation oscillations, and demonstrate that more pronounced no...

  3. Chimera in a neuronal network model of the cat brain

    OpenAIRE

    Santos, M. S.; Szezech Jr., J. D.; Borges, F. S.; Iarosz, K. C.; Caldas, I. L.; Batista, A. M.; Viana, R. L.; Kurths, J.

    2016-01-01

    Neuronal systems have been modeled by complex networks in different description levels. Recently, it has been verified that networks can simultaneously exhibit one coherent and other incoherent domain, known as chimera states. In this work, we study the existence of chimera states in a network considering the connectivity matrix based on the cat cerebral cortex. The cerebral cortex of the cat can be separated in 65 cortical areas organised into the four cognitive regions: visual, auditory, so...

  4. Phase-flip chimera induced by environmental nonlocal coupling.

    Science.gov (United States)

    Chandrasekar, V K; Gopal, R; Senthilkumar, D V; Lakshmanan, M

    2016-07-01

    We report the emergence of a collective dynamical state, namely, the phase-flip chimera, from an ensemble of identical nonlinear oscillators that are coupled indirectly via the dynamical variables from a common environment, which in turn are nonlocally coupled. The phase-flip chimera is characterized by the coexistence of two adjacent out-of-phase synchronized coherent domains interspersed by an incoherent domain, in which the nearby oscillators are in out-of-phase synchronized states. Attractors of the coherent domains are either from the same or from different basins of attractions, depending on whether they are periodic or chaotic. The conventional chimera precedes the phase-flip chimera in general. Further, the phase-flip chimera emerges after the completely synchronized evolution of the ensemble, in contrast to conventional chimeras, which emerge as an intermediate state between completely incoherent and coherent states. We have also characterized the observed dynamical transitions using the strength of incoherence, probability distribution of the correlation coefficient, and framework of the master stability function. PMID:27575124

  5. The costs and benefits of being a chimera.

    Science.gov (United States)

    Foster, Kevin R; Fortunato, Angelo; Strassmann, Joan E; Queller, David C

    2002-11-22

    Most multicellular organisms are uniclonal. This is hypothesized to be because uniclonal organisms function better than chimeras (non-clonal organisms), owing to reduced levels of internal genetic conflict. We tested this idea using the social amoeba or slime mold Dictyostelium discoideum. When starving, the normally solitary amoebae aggregate to form a differentiated multicellular slug that migrates towards light and forms a fruiting body, facilitating the dispersal of spores. We added 10(7) amoebae to Petri plates containing 1, 2, 5 or 10 clones mixed together. We found an intrinsic cost to chimerism: chimeric slugs moved significantly less far than uniclonal slugs of the same size. However, in nature, joining with other clones to form a chimera should increase slug size, and larger slugs travel further. We incorporated this size effect into a second experiment by giving chimeras more cells than single clones (single clones had 10(6) cells, two-clone chimeras had 2 x 10(6) cells and so on). The uniclonal treatments then simulated a clone in a mixture that refuses to form chimeras. In this experiment, chimeras moved significantly further than the uniclonal slugs, in spite of the intrinsic cost. Thus, chimerism is costly, which may be why it evolves so seldom, but in D. discoideum the benefits of large size appear to compensate. PMID:12495504

  6. Phase-flip chimera induced by environmental nonlocal coupling

    Science.gov (United States)

    Chandrasekar, V. K.; Gopal, R.; Senthilkumar, D. V.; Lakshmanan, M.

    2016-07-01

    We report the emergence of a collective dynamical state, namely, the phase-flip chimera, from an ensemble of identical nonlinear oscillators that are coupled indirectly via the dynamical variables from a common environment, which in turn are nonlocally coupled. The phase-flip chimera is characterized by the coexistence of two adjacent out-of-phase synchronized coherent domains interspersed by an incoherent domain, in which the nearby oscillators are in out-of-phase synchronized states. Attractors of the coherent domains are either from the same or from different basins of attractions, depending on whether they are periodic or chaotic. The conventional chimera precedes the phase-flip chimera in general. Further, the phase-flip chimera emerges after the completely synchronized evolution of the ensemble, in contrast to conventional chimeras, which emerge as an intermediate state between completely incoherent and coherent states. We have also characterized the observed dynamical transitions using the strength of incoherence, probability distribution of the correlation coefficient, and framework of the master stability function.

  7. 4{pi} studies of the 1.8{endash}4.8 GeV {sup 3}He+{sup nat}Ag, {sup 197}Au reactions. I. Energy deposition

    Energy Technology Data Exchange (ETDEWEB)

    Morley, K.B.; Kwiatkowski, K.; Bracken, D.S.; Renshaw Foxford, E.; Viola, V.E.; Woo, L.W.; Yoder, N.R. [Departments of Chemistry and Physics and Indiana University Cyclotron Facility, Indiana University, Bloomington, Indiana 47405 (United States); Legrain, R.; Pollacco, E.C.; Volant, C. [Commissariat a l`Energie Atomique, DAPNIA Service de Physique Nucleaire, C.E. Saclay, 91191 Gir-sur-Yvette Cedex (France); Korteling, R.G. [Department of Chemistry, Simon Fraser University, Burnaby, British Columbia (Canada); Breuer, H. [University of Maryland, College Park, Maryland 20742 (United States); Brzychczyk, J. [Institute of Physics, Jagiellonian University, 30-059 Krakow (Poland)

    1996-08-01

    The Indiana Silicon Sphere 4{pi} detector has been used to measure light-charged particles and intermediate-mass fragments (IMFs) emitted in the 18{endash}4.8 GeV {sup 3}He+{sup nat}Ag, {sup 197}Au reactions. Ejectile multiplicity and total event kinetic energy distributions scale systematically with projectile energy and target mass, except for the {sup nat}Ag target at 3.6 and 4.8 GeV. For this system, a saturation in deposition energy is indicated by the data, suggesting the upper projectile energy for stopping has been reached. Maximum deposition energies of {approximately}950 MeV for the {sup nat}Ag target and {approximately}1600 MeV for the {sup 197}Au target are inferred from the data. The results also demonstrate the importance of accounting for fast cascade processes in defining the excitation energy of the targetlike residue. Correlations between various observables and the average IMF multiplicity indicate that the total thermal energy and total observed charge provide useful gauges of the excitation energy of the fragmenting system. Comparison of the experimental distributions with intranuclear cascade predictions shows qualitative agreement. {copyright} {ital 1996 The American Physical Society.}

  8. A gamma-ray detector array for joint spectroscopy experiments at the JAERI tandem-booster facility

    CERN Document Server

    Furuno, K; Komatsubara, T; Furutaka, K; Hayakawa, T; Kidera, M; Hatsukawa, Y; Matsuda, M; Mitarai, S; Shizuma, T; Saitoh, T R; Hashimoto, N; Kusakari, H; Sugawara, M; Morikawa, T

    1999-01-01

    A compact array for gamma-ray spectroscopy developed for the joint experiment at the Japan Atomic Energy Research Institute is described. It consists of an array of 11 Compton suppressed Ge detectors, a 4 pi silicon detector array for charged particle measurements, a position-sensitive silicon detector for experiments on Coulomb excitation and a conversion-electron spectrometer. The details of the detectors and new experimental results obtained with the compact array are also described.

  9. Modeling Quark Gluon Plasma Using CHIMERA

    CERN Document Server

    Abelev, Betty B I

    2011-01-01

    We attempt to model Quark Gluon Plasma (QGP) evolution from the initial Heavy Ion collision to the final hadronic gas state by combining the Glauber model initial state conditions with eccentricity fluctuations, pre-equilibrium flow, UVH2+1 viscous hydrodynamics with lattice QCD Equation of State (EoS), a modified Cooper-Frye freeze-out and the UrQMD hadronic cascade. We then evaluate the model parameters using a comprehensive analytical framework which together with the described model we call CHIMERA. Within our framework, the initial state parameters, such as the initial temperature (T$_{\\mathrm{init}}$), presence or absence of initial flow, viscosity over entropy density ($\\eta$/s) and different Equations of State (EoS), are varied and then compared simultaneously to several experimental data observables: HBT radii, particle spectra and particle flow. $\\chi^2$/nds values from comparison to the experimental data for each set of initial parameters will then used to find the optimal description of the QGP wi...

  10. Allogeneic radiation chimeras: long-term studies

    International Nuclear Information System (INIS)

    Lethally irradiated mice protected with allogeneic fetal liver cells or with syngeneic or allogeneic marrow and spleen cells treated with antisera to mouse immunoglobulins or to the T cell-associated 0 antigen and their controls were observed for up to 750 days. The best survival rates were found in the large groups given syngeneic marrow and spleen or allogeneic fetal liver cells (70-85 percent 700-day survival); in contrast, 43 percent of the group injected with allogeneic cells treated with anti-0 serum and 19 percent of those given antimmunoglobulin-treated cells were alive 700 days postradiation. Pulmonary infection was the most frequent cause of death of long-term survivors in all groups. Tumor incidence was increased in recipients of allogeneic cells (13 percent versus 4 percent among syngeneic chimeras), but the renal pathology seen in these groups was no greater than that noted in the syngeneic controls. Beginning 600 days after irradiation, mice from experimental and control groups were killed and their spleens were cultured with thymus-dependent antigens and the mitogens concanavalin Λ and lipopolysaccharide, Escherichia coli. The most frequent finding in all groups was mild to moderate impairment of T cell-dependent responses. (U.S.)

  11. Model bridging chimera state and explosive synchronization

    Science.gov (United States)

    Zhang, Xiyun; Bi, Hongjie; Guan, Shuguang; Liu, Jinming; Liu, Zonghua

    2016-07-01

    Global synchronization and partial synchronization are the two distinctive forms of synchronization in coupled oscillators and have been well studied in recent decades. Recent attention on synchronization is focused on the chimera state (CS) and explosive synchronization (ES), but little attention has been paid to their relationship. Here we study this topic by presenting a model to bridge these two phenomena, which consists of two groups of coupled oscillators, and its coupling strength is adaptively controlled by a local order parameter. We find that this model displays either CS or ES in two limits. In between the two limits, this model exhibits both CS and ES, where CS can be observed for a fixed coupling strength and ES appears when the coupling is increased adiabatically. Moreover, we show both theoretically and numerically that there are a variety of CS basin patterns for the case of identical oscillators, depending on the distributions of both the initial order parameters and the initial average phases. This model suggests a way to easily observe CS, in contrast to other models having some (weak or strong) dependence on initial conditions.

  12. Amplitude-phase coupling drives chimera states in globally coupled laser networks

    OpenAIRE

    Böhm, Fabian; Zakharova, Anna; Schöll, Eckehard; Lüdge, Kathy

    2014-01-01

    For a globally coupled network of semiconductor lasers with delayed optical feedback, we demonstrate the existence of chimera states. The domains of coherence and incoherence that are typical for chimera states are found to exist for the amplitude, phase, and inversion of the coupled lasers. These chimera states defy several of the previously established existence criteria. While chimera states in phase oscillators generally demand nonlocal coupling, large system sizes, and specially prepared...

  13. Deterministic and stochastic control of chimera states in delayed feedback oscillator

    Science.gov (United States)

    Semenov, V.; Zakharova, A.; Maistrenko, Y.; Schöll, E.

    2016-06-01

    Chimera states, characterized by the coexistence of regular and chaotic dynamics, are found in a nonlinear oscillator model with negative time-delayed feedback. The control of these chimera states by external periodic forcing is demonstrated by numerical simulations. Both deterministic and stochastic external periodic forcing are considered. It is shown that multi-cluster chimeras can be achieved by adjusting the external forcing frequency to appropriate resonance conditions. The constructive role of noise in the formation of a chimera states is shown.

  14. Experimental study of jittering chimeras in a ring of excitable units

    Science.gov (United States)

    Klinshov, Vladimir; Shchapin, Dmitry; Lücken, Leonhard; Yanchuk, Serhiy; Nekorkin, Vladimir

    2016-06-01

    A new type of chimera-like regime is reported that we call "jittering chimera". The regime is observed in a ring of excitable units in which the excitation is invoked by an oscillator included into the ring. The jittering chimera is characterized by the presence of two domains, one with regular spiking and the other with irregular. A method to set and control desired chimera states in a physically implemented electronic circuit is developed.

  15. Chimera states in coupled Kuramoto oscillators with inertia

    Energy Technology Data Exchange (ETDEWEB)

    Olmi, Simona, E-mail: simona.olmi@fi.isc.cnr.it [CNR - Consiglio Nazionale delle Ricerche - Istituto dei Sistemi Complessi, via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy); INFN Sez. Firenze, via Sansone, 1 - I-50019 Sesto Fiorentino (Italy)

    2015-12-15

    The dynamics of two symmetrically coupled populations of rotators is studied for different values of the inertia. The system is characterized by different types of solutions, which all coexist with the fully synchronized state. At small inertia, the system is no more chaotic and one observes mainly quasi-periodic chimeras, while the usual (stationary) chimera state is not anymore observable. At large inertia, one observes two different kind of chaotic solutions with broken symmetry: the intermittent chaotic chimera, characterized by a synchronized population and a population displaying a turbulent behaviour, and a second state where the two populations are both chaotic but whose dynamics adhere to two different macroscopic attractors. The intermittent chaotic chimeras are characterized by a finite life-time, whose duration increases as a power-law with the system size and the inertia value. Moreover, the chaotic population exhibits clear intermittent behavior, displaying a laminar phase where the two populations tend to synchronize, and a turbulent phase where the macroscopic motion of one population is definitely erratic. In the thermodynamic limit, these states survive for infinite time and the laminar regimes tends to disappear, thus giving rise to stationary chaotic solutions with broken symmetry contrary to what observed for chaotic chimeras on a ring geometry.

  16. Chimera states in coupled Kuramoto oscillators with inertia

    Science.gov (United States)

    Olmi, Simona

    2015-12-01

    The dynamics of two symmetrically coupled populations of rotators is studied for different values of the inertia. The system is characterized by different types of solutions, which all coexist with the fully synchronized state. At small inertia, the system is no more chaotic and one observes mainly quasi-periodic chimeras, while the usual (stationary) chimera state is not anymore observable. At large inertia, one observes two different kind of chaotic solutions with broken symmetry: the intermittent chaotic chimera, characterized by a synchronized population and a population displaying a turbulent behaviour, and a second state where the two populations are both chaotic but whose dynamics adhere to two different macroscopic attractors. The intermittent chaotic chimeras are characterized by a finite life-time, whose duration increases as a power-law with the system size and the inertia value. Moreover, the chaotic population exhibits clear intermittent behavior, displaying a laminar phase where the two populations tend to synchronize, and a turbulent phase where the macroscopic motion of one population is definitely erratic. In the thermodynamic limit, these states survive for infinite time and the laminar regimes tends to disappear, thus giving rise to stationary chaotic solutions with broken symmetry contrary to what observed for chaotic chimeras on a ring geometry.

  17. Chimera states in coupled Kuramoto oscillators with inertia

    International Nuclear Information System (INIS)

    The dynamics of two symmetrically coupled populations of rotators is studied for different values of the inertia. The system is characterized by different types of solutions, which all coexist with the fully synchronized state. At small inertia, the system is no more chaotic and one observes mainly quasi-periodic chimeras, while the usual (stationary) chimera state is not anymore observable. At large inertia, one observes two different kind of chaotic solutions with broken symmetry: the intermittent chaotic chimera, characterized by a synchronized population and a population displaying a turbulent behaviour, and a second state where the two populations are both chaotic but whose dynamics adhere to two different macroscopic attractors. The intermittent chaotic chimeras are characterized by a finite life-time, whose duration increases as a power-law with the system size and the inertia value. Moreover, the chaotic population exhibits clear intermittent behavior, displaying a laminar phase where the two populations tend to synchronize, and a turbulent phase where the macroscopic motion of one population is definitely erratic. In the thermodynamic limit, these states survive for infinite time and the laminar regimes tends to disappear, thus giving rise to stationary chaotic solutions with broken symmetry contrary to what observed for chaotic chimeras on a ring geometry

  18. Multi-chimera states in the Leaky Integrate-and-Fire model

    OpenAIRE

    Tsigkri-DeSmedt, N. D.; Hizanidis, J.; Hoevel, P.; A. Provata

    2015-01-01

    We study the dynamics of identical leaky integrate-and-fire neurons with symmetric non-local coupling. Upon varying control parameters (coupling strength, coupling range, refractory period) we investigate the system's behaviour and highlight the formation of chimera states. We show that the introduction of a refractory period enlarges the parameter region where chimera states appear and affects the chimera multiplicity.

  19. Chimera-type states induced by local coupling

    Science.gov (United States)

    Clerc, M. G.; Coulibaly, S.; Ferré, M. A.; García-Ñustes, M. A.; Rojas, R. G.

    2016-05-01

    Coupled oscillators can exhibit complex self-organization behavior such as phase turbulence, spatiotemporal intermittency, and chimera states. The latter corresponds to a coexistence of coherent and incoherent states apparently promoted by nonlocal or global coupling. Here we investigate the existence, stability properties, and bifurcation diagram of chimera-type states in a system with local coupling without different time scales. Based on a model of a chain of nonlinear oscillators coupled to adjacent neighbors, we identify the required attributes to observe these states: local coupling and bistability between a stationary and an oscillatory state close to a homoclinic bifurcation. The local coupling prevents the incoherent state from invading the coherent one, allowing concurrently the existence of a family of chimera states, which are organized by a homoclinic snaking bifurcation diagram.

  20. Chimeras in locally coupled SQUIDs: Lions, goats and snakes

    CERN Document Server

    Hizanidis, J; Tsironis, G P

    2016-01-01

    We report on the emergence of robust multi-clustered chimera states in a dissipative-driven system of symmetrically and locally coupled identical SQUID oscillators. The "snake-like" resonance curve of the single SQUID (Superconducting QUantum Interference Device) is the key to the formation of the chimera states and is responsible for the extreme multistability exhibited by the coupled system that leads to attractor crowding at the geometrical resonance frequency. Until now, chimera states were mostly believed to exist for nonlocal coupling. Our findings provide theoretical evidence that nearest neighbor interactions is indeed capable of supporting such states in a wide parameter range. SQUID metamaterials are the subject of intense experimental investigations and we are highly confident that the complex dynamics demonstrated in this manuscript can be confirmed in the laboratory.

  1. Chimera-like states in modular neural networks

    CERN Document Server

    Hizanidis, Johanne; Zamora-López, Gorka; Díaz-Guilera, Albert; Antonopoulos, Chris G

    2016-01-01

    Chimera states, namely the coexistence of coherent and incoherent behavior, were previously analyzed in complex networks. However, they have not been extensively studied in modular networks. Here, we consider the neural network of the \\textit{C.elegans} soil worm, organized into six interconnected communities, where neurons obey chaotic bursting dynamics. Neurons are assumed to be connected with electrical synapses within their communities and with chemical synapses across them. As our numerical simulations reveal, the coaction of these two types of coupling can shape the dynamics in such a way that chimera-like states can happen. They consist of a fraction of synchronized neurons which belong to the larger communities, and a fraction of desynchronized neurons which are part of smaller communities. In addition to the Kuramoto order parameter $\\rho$, we also employ other measures of coherence, such as the chimera-like $\\chi$ and metastability $\\lambda$ indices, which quantify the degree of synchronization amon...

  2. Chimera States in Two Populations with Heterogeneous Phase-lag

    DEFF Research Database (Denmark)

    Martens, Erik Andreas

    2016-01-01

    The simplest network of coupled phase-oscillators exhibiting chimera states is given by two populations with disparate intra- and inter-population coupling strengths. We explore the effects of heterogeneous coupling phase-lags between the two populations. Such heterogeneity arises naturally......, we identify the bifurcations through which chimera and desynchronized states emerge. Stable chimera states and desynchronized solutions, which do not arise for homogeneous phase-lag parameters, emerge as a result of competition between synchronized in-phase, anti-phase equilibria, and fully...... incoherent states when the phase-lags are near ±π/2 (cosine coupling). These findings elucidate previous experimental results involving a network of mechanical oscillators and provide further insight into the breakdown of synchrony in biological systems....

  3. Chimera states and synchronization in magnetically driven SQUID metamaterials

    Science.gov (United States)

    Hizanidis, J.; Lazarides, N.; Neofotistos, G.; Tsironis, G. P.

    2016-09-01

    One-dimensional arrays of Superconducting QUantum Interference Devices (SQUIDs) form magnetic metamaterials exhibiting extraordinary properties, including tunability, dynamic multistability, negative magnetic permeability, and broadband transparency. The SQUIDs in a metamaterial interact through non-local, magnetic dipole-dipole forces, that makes it possible for multiheaded chimera states and coexisting patterns, including solitary states, to appear. The spontaneous emergence of chimera states and the role of multistability is demonstrated numerically for a SQUID metamaterial driven by an alternating magnetic field. The spatial synchronization and temporal complexity are discussed and the parameter space for the global synchronization reveals the areas of coherence-incoherence transition. Given that both one- and two-dimensional SQUID metamaterials have been already fabricated and investigated in the lab, the presence of a chimera state could in principle be detected with presently available experimental set-ups.

  4. Robust chimera states in SQUID metamaterials with local interactions

    Science.gov (United States)

    Hizanidis, J.; Lazarides, N.; Tsironis, G. P.

    2016-09-01

    We report on the emergence of robust multiclustered chimera states in a dissipative-driven system of symmetrically and locally coupled identical superconducting quantum interference device (SQUID) oscillators. The "snakelike" resonance curve of the single SQUID is the key to the formation of the chimera states and is responsible for the extreme multistability exhibited by the coupled system that leads to attractor crowding at the geometrical resonance (inductive-capacitive) frequency. Until now, chimera states were mostly believed to exist for nonlocal coupling. Our findings provide theoretical evidence that nearest-neighbor interactions are indeed capable of supporting such states in a wide parameter range. SQUID metamaterials are the subject of intense experimental investigations, and we are highly confident that the complex dynamics demonstrated in this paper can be confirmed in the laboratory.

  5. Delayed-feedback chimera states: Forced multiclusters and stochastic resonance

    Science.gov (United States)

    Semenov, V.; Zakharova, A.; Maistrenko, Y.; Schöll, E.

    2016-07-01

    A nonlinear oscillator model with negative time-delayed feedback is studied numerically under external deterministic and stochastic forcing. It is found that in the unforced system complex partial synchronization patterns like chimera states as well as salt-and-pepper-like solitary states arise on the route from regular dynamics to spatio-temporal chaos. The control of the dynamics by external periodic forcing is demonstrated by numerical simulations. It is shown that one-cluster and multi-cluster chimeras can be achieved by adjusting the external forcing frequency to appropriate resonance conditions. If a stochastic component is superimposed to the deterministic external forcing, chimera states can be induced in a way similar to stochastic resonance, they appear, therefore, in regimes where they do not exist without noise.

  6. Existence of Chimera State on Two Parallel Circles

    Science.gov (United States)

    Lin, Larry; Yang, Pei-Kun

    2016-06-01

    A nonlocal coupling system with oscillators on two parallel circles can evolve into a chimera state for suitable values of the parameters α and β. The parameter β is the distance between the circles and affects the phase-locked areas of the chimera state. The Kuramoto theory successfully describes whether and where the oscillators are phase-locked or drifting. The position difference ΔX describes the displacement of phase-locked areas between the circles. The dynamics of the model with four oscillators also show similar phenomena. The position difference ΔX results from the arrangement of oscillators on the two parallel circles.

  7. Progress in Grid Generation: From Chimera to DRAGON Grids

    Science.gov (United States)

    Liou, Meng-Sing; Kao, Kai-Hsiung

    1994-01-01

    Hybrid grids, composed of structured and unstructured grids, combines the best features of both. The chimera method is a major stepstone toward a hybrid grid from which the present approach is evolved. The chimera grid composes a set of overlapped structured grids which are independently generated and body-fitted, yielding a high quality grid readily accessible for efficient solution schemes. The chimera method has been shown to be efficient to generate a grid about complex geometries and has been demonstrated to deliver accurate aerodynamic prediction of complex flows. While its geometrical flexibility is attractive, interpolation of data in the overlapped regions - which in today's practice in 3D is done in a nonconservative fashion, is not. In the present paper we propose a hybrid grid scheme that maximizes the advantages of the chimera scheme and adapts the strengths of the unstructured grid while at the same time keeps its weaknesses minimal. Like the chimera method, we first divide up the physical domain by a set of structured body-fitted grids which are separately generated and overlaid throughout a complex configuration. To eliminate any pure data manipulation which does not necessarily follow governing equations, we use non-structured grids only to directly replace the region of the arbitrarily overlapped grids. This new adaptation to the chimera thinking is coined the DRAGON grid. The nonstructured grid region sandwiched between the structured grids is limited in size, resulting in only a small increase in memory and computational effort. The DRAGON method has three important advantages: (1) preserving strengths of the chimera grid; (2) eliminating difficulties sometimes encountered in the chimera scheme, such as the orphan points and bad quality of interpolation stencils; and (3) making grid communication in a fully conservative and consistent manner insofar as the governing equations are concerned. To demonstrate its use, the governing equations are

  8. Mechanisms of tolerance in murine radiation bone marrow chimeras. II. Absence of nonspecific suppression in mature chimeras

    International Nuclear Information System (INIS)

    Spleen cells from a series of allogeneic bone marrow chimeras were sensitized in vitro with stimulator cells from major histocompatibility complex recombinant strains of mice. The combinations were chosen such that both tolerated (host or donor) and nontolerated (third-party) antigens were present on the same stimulator cells in order to determine whether the tolerated host antigens might elicit nonspecific suppressor mechanisms affecting the cell-mediated lympholysis (CML) response to the nontolerated antigens. No evidence for such nonspecific suppression was obtained in several types of assays. Therefore, if suppressor mechanisms exist that mediate such tolerance in mature allogeneic chimeras then these mechanisms must be highly antigen-specific

  9. Characterization of host lymphoid cells in antibody-facilitated bone marrow chimeras

    International Nuclear Information System (INIS)

    The authors have produced stable murine antibody-facilitated (AF) chimeras by the simultaneous injection of P1 bone marrow cells and anti-P2 monoclonal antibody into normal (unirradiated) adult (P1 X P2)F1 recipients. These AF chimeras are healthy, long-lived, and exhibit no overt signs of graft-versus-host disease. They are immunocompetent and tolerant of host, P2-encoded alloantigens. Donor cell engraftment and takeover, monitored by glucosephosphate isomerase isozyme patterns, is usually complete (greater than 95%) in the peripheral blood, bone marrow, and hemopoietic stem cell compartments of long-term (greater than 3 months posttransplantation) AF chimeras. The authors report here, however, that splenic, lymph node, and thymic leukocytes of AF chimeras represent donor/host chimeric populations. Spleen cell populations of AF chimeras exhibit substantial chimera-to-chimera variation in the preponderant residual host cell type(s) present. Interpretations of the implications of these findings are discussed

  10. Selection and integration of a network of parallel processors in the real time acquisition system of the 4{pi} DIAMANT multidetector: modeling, realization and evaluation of the software installed on this network; Choix et integration d`un reseau de processeurs paralleles dans le systeme d`acquisition temps reel du multidetecteur 4{pi} DIAMANT: modelisation, realisation et evaluation du logiciel implante sur ce reseau

    Energy Technology Data Exchange (ETDEWEB)

    Guirande, F. [Ecole Doctorale des Sciences Physiques et de l`Ingenieur, Bordeaux-1 Univ., 33 (France)

    1997-07-11

    The increase in sensitivity of 4{pi} arrays such as EUROBALL or DIAMANT has led to an increase in the data flow rate into the data acquisition system. If at the electronic level, the data flow has been distributed onto several data acquisition buses, it is necessary in the data processing system to increase the processing power. This work regards the modelling and implementation of the software allocated onto an architecture of parallel processors. Object analysis and formal methods were used, benchmark and evolution in the future of this architecture are presented. The thesis consists of two parts. Part A, devoted to `Nuclear Spectroscopy with 4 {pi} multidetectors`, contains a first chapter entitled `The Physics of 4{pi} multidetectors` and a second chapter entitled `Integral architecture of 4{pi} multidetectors`. Part B, devoted to `Parallel acquisition system of DIAMANT` contains three chapters entitled `Material architecture`, `Software architecture` and `Validation and Performances`. Four appendices and a term glossary close this work. (author) 58 refs.

  11. Chimera: construction of chimeric sequences for phylogenetic analysis

    NARCIS (Netherlands)

    Leunissen, J.A.M.

    2003-01-01

    Chimera allows the construction of chimeric protein or nucleic acid sequence files by concatenating sequences from two or more sequence files in PHYLIP formats. It allows the user to interactively select genes and species from the input files. The concatenated result is stored to one single output f

  12. CHIMERA CBRN protective suit. Advanced embodiment design. Final report

    NARCIS (Netherlands)

    Bogerd, C.P.; Smit, B. de; Olarte, C.; Kane, G.; Bie, M. de; Megen, X. van; Schenk, J.; Hooop, J. de

    2015-01-01

    The Chimera project started of with the following design challenge: Designing a switchable CBRN (chemical, biological, radiological, nuclear) protective suit for soldiers, one phase being a regular work state and the other phase being a protective state to enable the soldier to get away from the tox

  13. What’s Wrong with Human/Nonhuman Chimera Research?

    Science.gov (United States)

    Hyun, Insoo

    2016-01-01

    The National Institutes of Health (NIH) is poised to lift its funding moratorium on research involving chimeric human/nonhuman embryos, pending further consideration by an NIH steering committee. The kinds of ethical concerns that seem to underlie this research and chimera research more generally can be adequately addressed. PMID:27574863

  14. Resistance to BN myelogenous leukemia in rat radiation chimeras

    International Nuclear Information System (INIS)

    Lewis → LBNFl rat radiation chimeras showed marked resistance to transplanted BN myelogenous leukemia when compared to naive LBNFl, LBNFl → LBNFl, or BN → LBNFl. This occurred in the absence of overt graft versus host disease or of anti-BN response in mixed lymphocyte culture. Bone marrow specific antigens may serve as the target of the resistance mechanism. (author)

  15. Chimera states in two populations with heterogeneous phase-lag

    Science.gov (United States)

    Martens, Erik A.; Bick, Christian; Panaggio, Mark J.

    2016-09-01

    The simplest network of coupled phase-oscillators exhibiting chimera states is given by two populations with disparate intra- and inter-population coupling strengths. We explore the effects of heterogeneous coupling phase-lags between the two populations. Such heterogeneity arises naturally in various settings, for example, as an approximation to transmission delays, excitatory-inhibitory interactions, or as amplitude and phase responses of oscillators with electrical or mechanical coupling. We find that breaking the phase-lag symmetry results in a variety of states with uniform and non-uniform synchronization, including in-phase and anti-phase synchrony, full incoherence (splay state), chimera states with phase separation of 0 or π between populations, and states where both populations remain desynchronized. These desynchronized states exhibit stable, oscillatory, and even chaotic dynamics. Moreover, we identify the bifurcations through which chimeras emerge. Stable chimera states and desynchronized solutions, which do not arise for homogeneous phase-lag parameters, emerge as a result of competition between synchronized in-phase, anti-phase equilibria, and fully incoherent states when the phase-lags are near ± /π 2 (cosine coupling). These findings elucidate previous experimental results involving a network of mechanical oscillators and provide further insight into the breakdown of synchrony in biological systems.

  16. Detector problems at the SSC

    Energy Technology Data Exchange (ETDEWEB)

    Wojcicki, S.G.

    1985-02-01

    During the last couple of years there has been considerable concern expressed among the US high energy community as to whether detector limitations would prevent one from being able to fully exploit a luminosity of 10/sup 33/ cm/sup -2/ sec/sup -1/ at a hadron-hadron high energy collider. As a result of these concerns, a considerable amount of work has been done recently in trying to understand the nature of potential difficulties and the required R and D that needs to be performed. A lot of this work has been summarized in the 1984 DPF Summer Study at Snowmass. This paper attempts to review some of these results. This work is limited to the discussion of detector problems associated with the study of high energy hadron-hadron collisions. We shall start with the discussion of the desirable features of the detectors and of the SSC environment in which they will have to work. After a brief discussion of the model 4..pi.. detectors, we shall discuss specific detector aspects: lepton identification, tracking, calorimetry and computing and triggering. We shall end with some remarks about possible future course of events. 15 refs., 10 figs.

  17. Amplitude-phase coupling drives chimera states in globally coupled laser networks

    Science.gov (United States)

    Böhm, Fabian; Zakharova, Anna; Schöll, Eckehard; Lüdge, Kathy

    2015-04-01

    For a globally coupled network of semiconductor lasers with delayed optical feedback, we demonstrate the existence of chimera states. The domains of coherence and incoherence that are typical for chimera states are found to exist for the amplitude, phase, and inversion of the coupled lasers. These chimera states defy several of the previously established existence criteria. While chimera states in phase oscillators generally demand nonlocal coupling, large system sizes, and specially prepared initial conditions, we find chimera states that are stable for global coupling in a network of only four coupled lasers for random initial conditions. The existence is linked to a regime of multistability between the synchronous steady state and asynchronous periodic solutions. We show that amplitude-phase coupling, a concept common in different fields, is necessary for the formation of the chimera states.

  18. Amplitude-phase coupling drives chimera states in globally coupled laser networks

    CERN Document Server

    Böhm, Fabian; Schöll, Eckehard; Lüdge, Kathy

    2014-01-01

    For a globally coupled network of semiconductor lasers with delayed optical feedback, we demonstrate the existence of chimera states. The domains of coherence and incoherence that are typical for chimera states are found to exist for the amplitude, phase, and inversion of the coupled lasers. These chimera states defy several of the previously established existence criteria. While chimera states in phase oscillators generally demand nonlocal coupling, large system sizes, and specially prepared initial conditions, we find chimera states that are stable for global coupling in a network of only four coupled lasers for random initial conditions. The existence is linked to a regime of multistability between the synchronous steady state and asynchronous periodic solutions. We show that amplitude-phase coupling, a concept common in different fields, is necessary for the formation of the chimera states.

  19. The oscillating two-cluster chimera state in non-locally coupled phase oscillators

    OpenAIRE

    Zhu, Yun; Li, Yuting; ZHANG, MEI; Yang, Junzhong

    2011-01-01

    We investigate an array of identical phase oscillators non-locally coupled without time delay, and find that chimera state with two coherent clusters exists which is only reported in delay-coupled systems previously. Moreover, we find that the chimera state is not stationary for any finite number of oscillators. The existence of the two-cluster chimera state and its time-dependent behaviors for finite number of oscillators are confirmed by the theoretical analysis based on the self-consistenc...

  20. Chimera states in networks of nonlocally coupled Hindmarsh-Rose neuron models

    OpenAIRE

    Hizanidis, Johanne; Kanas, Vasilis; Bezerianos, Anastasios; Bountis, Tassos

    2013-01-01

    We have identified the occurrence of chimera states for various coupling schemes in networks of two-dimensional and three-dimensional Hindmarsh-Rose oscillators, which represent realistic models of neuronal ensembles. This result, together with recent studies on multiple chimera states in nonlocally coupled FitzHugh-Nagumo oscillators, provide strong evidence that the phenomenon of chimeras may indeed be relevant in neuroscience applications. Moreover, our work verifies the existence of chime...

  1. Metastable Chimera States in Community-Structured Oscillator Networks

    CERN Document Server

    Shanahan, Murray

    2010-01-01

    A system of symmetrically coupled identical oscillators with phase lag is presented, which is capable of generating a large repertoire of transient (metastable) "chimera" states in which synchronisation and desynchronisation co-exist. The oscillators are organised into communities, such that each oscillator is connected to all its peers in the same community and to a subset of the oscillators in other communities. Measures are introduced for quantifying metastability, the prevalence of chimera states, and the variety of such states a system generates. By simulation, it is shown that each of these measures is maximised when the phase lag of the model is close, but not equal, to pi/2. The relevance of the model to a number of fields is briefly discussed, with particular emphasis on brain dynamics.

  2. Origin of hemopoietic stromal progenitor cells in chimeras

    International Nuclear Information System (INIS)

    Intravenously injected bone marrow cells do not participate in the regeneration of hemopoietic stromal progenitors in irradiated mice, nor in the curetted parts of the recipient's marrow. The hemopoietic stromal progenitors in allogeneic chimeras are of recipient origin. The adherent cell layer (ACL) of long-term cultures of allogeneic chimera bone marrow contains only recipient hemopoietic stromal progenitors. However, in ectopic hemopoietic foci produced by marrow implantation under the renal capsule and repopulated by the recipient hemopoietic cells after irradiation and reconstitution by syngeneic hemopoietic cells, the stromal progenitors were of implant donor origin, as were stromal progenitors of the ACL in long-term cultures of hemopoietic cells from ectopic foci. Our results confirm that the stromal and hemopoietic progenitors differ in origin and that hemopoietic stromal progenitors are not transplantable by the intravenous route in mice

  3. Tolerance, immunocompetence, and secondary disease in fully allogeneic radiation chimeras

    International Nuclear Information System (INIS)

    The aim of this study was to ascertain the extent to which secondary disease and mortality in fully allogeneic chimeras (C57BL leads to CBA) is caused (if at all) by a delayed graft-versus-host reaction. Adult CBA males were thymectomized, irradiated, and reconstituted with T-lymphocyte-depleted C57BL or CBA bone marrow cells (BMC), followed three weeks after irradiation by implantation under the kidney capsule of thymic lobes from C57BL or CBA fetal or adult donors. These mice were observed for the development of secondary disease for periods in excess of 250 days, and they were examined at 5 weeks or 4 months for T lymphocyte reactivity and tolerance to alloantigens, using the cell-mediated lympholysis assay (CML). The following results were obtained. First, removal of T lymphocytes with anti-Thy 1 antibody and complement from allogeneic bone marrow did not prevent wasting and eventual death, although it prolonged the lifespan of mice substantially. Second, T lymphocytes generated from bone marrow-derived precursor cells became tolerant of the histocompatibility antigens of the thymus donor strain but remained normally reactive to third-party antigens. Third, allogeneic radiation chimeras did not survive as well as animals reconstituted with syngeneic cells, even when they were demonstrably tolerant in CML. Fourth, C57BL BMC maturing in a CBA host equipped with a C57BL thymus graft did not become tolerant of host antigens, indicating that extra-thymic tolerance does not occur in fully allogeneic--as opposed to semiallogeneic--chimeras. It is argued that the function of B lymphocytes and/or accessory cells is impaired in fully allogeneic radiation chimeras, and that the mortality observed was directly related to the resulting immunodeficiency. The relevance of the results described in this paper to clinical bone marrow transplantation is discussed

  4. Icing modelling in NSMB with chimera overset grids

    Energy Technology Data Exchange (ETDEWEB)

    Pena, D. [Ècole Polytechnique de Montréal (Canada); ICUBE, Strasbourg University (France); Deloze, T.; Laurendeau, E. [Ècole Polytechnique de Montréal (Canada); Hoarau, Y. [ICUBE, Strasbourg University (France)

    2015-03-10

    In aerospace Engineering, the accurate simulation of ice accretion is a key element to increase flight safety and avoid accidents related to icing effects. The icing code developed in the NSMB solver is based on an Eulerian formulation for droplets tracking, an iterative Messinger model using a modified water runback scheme for ice thickness calculation and mesh deformation to track the ice/air interface through time. The whole process is parallelized with MPI and applied with chimera grids.

  5. The costs and benefits of being a chimera.

    OpenAIRE

    Foster, Kevin R.; Fortunato, Angelo; Strassmann, Joan E.; Queller, David C

    2002-01-01

    Most multicellular organisms are uniclonal. This is hypothesized to be because uniclonal organisms function better than chimeras (non-clonal organisms), owing to reduced levels of internal genetic conflict. We tested this idea using the social amoeba or slime mold Dictyostelium discoideum. When starving, the normally solitary amoebae aggregate to form a differentiated multicellular slug that migrates towards light and forms a fruiting body, facilitating the dispersal of spores. We added 10(7)...

  6. Deficiency in early development of the thymus-dependent cells in irradiation chimeras attributable to recipient's environment

    International Nuclear Information System (INIS)

    Bone marrow chimeras were prepared using reciprocal combinations of AKR and C3H mice. When C3H mice were recipients, the number of thymocytes recoverable from such chimeras (C3H recipient chimeras) was small as compared with that from chimeras for which AKR mice were used as recipients (AKR recipient chimeras) regardless of donor strain. The thymocytes from C3H recipient chimeras showed a profound deficiency in generating proliferative responses to stimulation by anti-CD3 mAb (2C11) or anti-TCR (alpha, beta) mAb (H57-597), even though the expression of CD3 and TCR molecules fell within the same range as that in AKR recipient chimeras. Furthermore, after stimulation with immobilized 2C11, the proportion of IL-2R+ cells in the thymocytes from C3H recipient chimeras was much less than that in AKR recipient chimeras. However, no significant difference in proliferative responses to 2C11 plus PMA, in influx of Ca2+ after stimulation with 2C11 or IL-2 production in response to 2C11 plus PMA or PMA plus A23187 was demonstrated between C3H and AKR recipient chimeras. These findings suggest that the thymocytes from C3H recipient chimeras have a deficiency in the signal transduction system as compared with chimeras for which AKR mice are the recipients. The thymic stromal component involved in this difference in the C3H recipient chimeras is discussed

  7. Chimeras, moral status, and public policy: implications of the abortion debate for public policy on human/nonhuman chimera research.

    Science.gov (United States)

    Streiffer, Robert

    2010-01-01

    Researchers are increasingly interested in creating chimeras by transplanting human embryonic stem cells (hESCs) into animals early in development. One concern is that such research could confer upon an animal the moral status of a normal human adult but then impermissibly fail to accord it the protections it merits in virtue of its enhanced moral status. Understanding the public policy implications of this ethical conclusion, though, is complicated by the fact that claims about moral status cannot play an unfettered role in public policy. Arguments like those employed in the abortion debate for the conclusion that abortion should be legally permissible even if abortion is not morally permissible also support, to a more limited degree, a liberal policy on hESC research involving the creation of chimeras.

  8. Chimeras, moral status, and public policy: implications of the abortion debate for public policy on human/nonhuman chimera research.

    Science.gov (United States)

    Streiffer, Robert

    2010-01-01

    Researchers are increasingly interested in creating chimeras by transplanting human embryonic stem cells (hESCs) into animals early in development. One concern is that such research could confer upon an animal the moral status of a normal human adult but then impermissibly fail to accord it the protections it merits in virtue of its enhanced moral status. Understanding the public policy implications of this ethical conclusion, though, is complicated by the fact that claims about moral status cannot play an unfettered role in public policy. Arguments like those employed in the abortion debate for the conclusion that abortion should be legally permissible even if abortion is not morally permissible also support, to a more limited degree, a liberal policy on hESC research involving the creation of chimeras. PMID:20579247

  9. CHIMERA: a wide-field, multi-colour, high-speed photometer at the prime focus of the Hale telescope

    Science.gov (United States)

    Harding, L. K.; Hallinan, G.; Milburn, J.; Gardner, P.; Konidaris, N.; Singh, N.; Shao, M.; Sandhu, J.; Kyne, G.; Schlichting, H. E.

    2016-04-01

    The Caltech HIgh-speed Multi-colour camERA (CHIMERA) is a new instrument that has been developed for use at the prime focus of the Hale 200-inch telescope. Simultaneous optical imaging in two bands is enabled by a dichroic beam splitter centred at 567 nm, with Sloan u' and g' bands available on the blue arm and Sloan r', i' and z_s bands available on the red arm. Additional narrow-band filters will also become available as required. An electron multiplying CCD (EMCCD) detector is employed for both optical channels, each capable of simultaneously delivering sub-electron effective read noise under multiplication gain and frame rates of up to 26 fps full frame (several 1000 fps windowed), over a fully corrected 5 × 5 arcmin field of view. CHIMERA was primarily developed to enable the characterization of the size distribution of sub-km Kuiper Belt Objects via stellar occultation, a science case that motivates the frame-rate, the simultaneous multi-colour imaging and the wide field of view of the instrument. In addition, it also has unique capability in the detection of faint near-Earth asteroids and will be used for the monitoring of short-duration transient and periodic sources, particularly those discovered by the intermediate Palomar Transient Factory (iPTF), and the upcoming Zwicky Transient Facility (ZTF).

  10. CHIMERA: a wide-field, multi-color, high-speed photometer at the prime focus of the Hale telescope

    CERN Document Server

    Harding, Leon K; Milburn, Jennifer; Gardner, Paul; Konidaris, Nick; Singh, Navtej; Shao, Michael; Sandhu, Jagmit; Kyne, Gillian; Schlichting, Hilke E

    2016-01-01

    The Caltech HIgh-speed Multi-color camERA (CHIMERA) is a new instrument that has been developed for use at the prime focus of the Hale 200-inch telescope. Simultaneous optical imaging in two bands is enabled by a dichroic beam splitter centered at 567 nm, with Sloan u' and g' bands available on the blue arm and Sloan r', i' and z_s' bands available on the red arm. Additional narrow-band filters will also become available as required. An Electron Multiplying CCD (EMCCD) detector is employed for both optical channels, each capable of simultaneously delivering sub-electron effective read noise under multiplication gain and frame rates of up to 26 fps full frame (several 1000 fps windowed), over a fully corrected 5 x 5 arcmin field of view. CHIMERA was primarily developed to enable the characterization of the size distribution of sub-km Kuiper Belt Objects via stellar occultation, a science case that motivates the frame-rate, the simultaneous multi-color imaging and the wide field of view of the instrument. In ad...

  11. Preliminary study for the detection of neutrons in heavy-ion collisions with charged particle detectors

    Directory of Open Access Journals (Sweden)

    Auditore L.

    2015-01-01

    Full Text Available At Laboratori Nazionali del Sud (LNS the CHIMERA 4π multidetector has been designed and setup to detect charged particles emitted in heavy ion collisions at intermediate energies. Properties and performances of CHIMERA have been widely demonstrated by published results obtained in the performed experiments. Moreover, in recent years, a new charged particle detector (ChPD for correlation studies (FARCOS has been designed, and recently a first prototype has been coupled to CHIMERA, in order to test performances in view of correlation measurements in coincidence with 4π detectors. Simultaneous neutrons and charged particles detection in heavy ion collisions represents an important experimental progress for future experiments to be performed with both stable and exotic nuclei. In order to investigate about this possibility, simple Monte Carlo simulations have been performed. Preliminary simulations have been carried out by means of MCNPX transport code to evaluate the perturbation effects, including cross-talk and time response, induced in CHIMERA and/or FARCOS Si-CsI(Tl telescopes on (typical 20MeV neutron signals coming froma typical reaction in heavy ion collisions at the Fermi energy. Moreover, first data analysis results of the INKIISSY experiment indicates sizable probability to detect neutrons by properly shadowing CHIMERA Si-CsI(Tl telescopes. Analysis is still in progress.

  12. A VMEbus interface for multi-detector trigger and control system

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    MUSE (MUltiplicity SElector) is the trigger and control system of CHIMERA, a 4π charged particles detector. Initialization of MUSE can be performed via VMEbus. This paper describes the design of VMEbus interface and functional module in MUSE, and briefs an application of MUSE.

  13. A VMEbus interface for multi-detector trigger and control system

    International Nuclear Information System (INIS)

    MUSE (MUltiplicity SElector) is the trigger and control system of CHIMERA, a 4π charged particles detector. Initialization of MUSE can be performed via VMEbus. The author describes the design of VMEbus interface and functional module in MUSE, and briefs an application of MUSE

  14. Bio-inspired Silicification of Silica-binding Peptide-Silk Protein Chimeras: Comparison of Chemically and Genetically Produced Proteins

    OpenAIRE

    Canabady-Rochelle, Laetitia L.S.; Belton, David J.; Deschaume, Olivier; Currie, Heather A.; Kaplan, David L; Perry, Carole C.

    2012-01-01

    Novel protein chimeras constituted of ‘silk’ and a silica-binding peptide (KSLSRHDHIHHH) were synthesized by genetic or chemical approaches and their influence on silica-silk based chimera composite formation evaluated. Genetic chimeras were constructed from 6 or 15 repeats of the 32 amino acid consensus sequence of Nephila clavipes spider silk ([SGRGGLGGQG AGAAAAAGGA GQGGYGGLGSQG]n) to which one silica binding peptide was fused at the N terminus. For the chemical chimera, 25 equivalents of t...

  15. MicroRNA-7 inhibits the stemness of prostate cancer stem-like cells and tumorigenesis by repressing KLF4/PI3K/Akt/p21 pathway.

    Science.gov (United States)

    Chang, Yun-Li; Zhou, Pei-Jie; Wei, Lianzi; Li, Wang; Ji, Zhongzhong; Fang, Yu-Xiang; Gao, Wei-Qiang

    2015-09-15

    Up to now, the molecular mechanisms underlying the stemness of prostate cancer stem cells (PCSCs) are still poorly understood. In this study, we demonstrated that microRNA-7 (miR-7) appears to be a novel tumor-suppressor miRNA, which abrogates the stemness of PCSCs and inhibits prostate tumorigenesis by suppressing a key stemness factor KLF4. MicroRNA-7 is down-regulated in prostate cancer cells compared to non-tumorigenic prostate epithelial cells. Restoration of miR-7 suppresses the expression of the stemness factor KLF4 in PCSCs and inhibits prostate tumorigenesis both in vitro and in vivo. Interestingly, the suppression of the stemness of PCSCs by miR-7 is sustained for generations in xenografts. Analysis of clinical samples also revealed a negative correlation between miR-7 expression and prostate tumor progression. Mechanistically, overexpression of miR-7 may lead to a cell cycle arrest but not apoptosis, which seems achieved via suppressing the KLF4/PI3K/Akt/p21 pathway. This study identifies miR-7 as a suppressor of PCSCs' stemness and implicates its potential application for PCa therapy.

  16. Characteristic distribution of finite-time Lyapunov exponents for chimera states

    Science.gov (United States)

    Botha, André E.

    2016-07-01

    Our fascination with chimera states stems partially from the somewhat paradoxical, yet fundamental trait of identical, and identically coupled, oscillators to split into spatially separated, coherently and incoherently oscillating groups. While the list of systems for which various types of chimeras have already been detected continues to grow, there is a corresponding increase in the number of mathematical analyses aimed at elucidating the fundamental reasons for this surprising behaviour. Based on the model systems, there are strong indications that chimera states may generally be ubiquitous in naturally occurring systems containing large numbers of coupled oscillators – certain biological systems and high-Tc superconducting materials, for example. In this work we suggest a new way of detecting and characterising chimera states. Specifically, it is shown that the probability densities of finite-time Lyapunov exponents, corresponding to chimera states, have a definite characteristic shape. Such distributions could be used as signatures of chimera states, particularly in systems for which the phases of all the oscillators cannot be measured directly. For such cases, we suggest that chimera states could perhaps be detected by reconstructing the characteristic distribution via standard embedding techniques, thus making it possible to detect chimera states in systems where they could otherwise exist unnoticed.

  17. Advances in Chimera Grid Tools for Multi-Body Dynamics Simulations and Script Creation

    Science.gov (United States)

    Chan, William M.

    2004-01-01

    This viewgraph presentation contains information about (1) Framework for multi-body dynamics - Geometry Manipulation Protocol (GMP), (2) Simulation procedure using Chimera Grid Tools (CGT) and OVERFLOW-2 (3) Further recent developments in Chimera Grid Tools OVERGRID, Grid modules, Script library and (4) Future work.

  18. Characteristic distribution of finite-time Lyapunov exponents for chimera states.

    Science.gov (United States)

    Botha, André E

    2016-01-01

    Our fascination with chimera states stems partially from the somewhat paradoxical, yet fundamental trait of identical, and identically coupled, oscillators to split into spatially separated, coherently and incoherently oscillating groups. While the list of systems for which various types of chimeras have already been detected continues to grow, there is a corresponding increase in the number of mathematical analyses aimed at elucidating the fundamental reasons for this surprising behaviour. Based on the model systems, there are strong indications that chimera states may generally be ubiquitous in naturally occurring systems containing large numbers of coupled oscillators - certain biological systems and high-Tc superconducting materials, for example. In this work we suggest a new way of detecting and characterising chimera states. Specifically, it is shown that the probability densities of finite-time Lyapunov exponents, corresponding to chimera states, have a definite characteristic shape. Such distributions could be used as signatures of chimera states, particularly in systems for which the phases of all the oscillators cannot be measured directly. For such cases, we suggest that chimera states could perhaps be detected by reconstructing the characteristic distribution via standard embedding techniques, thus making it possible to detect chimera states in systems where they could otherwise exist unnoticed. PMID:27374473

  19. Mechanisms of tolerance in murine radiation bone marrow chimeras. I. Nonspecific suppression of alloreactivity by spleen cells from early, but not late, chimeras

    International Nuclear Information System (INIS)

    Allogeneic chimeras were prepared using lethally irradiated B6 hosts and untreated marrow from exsanguinated BALB/c donors. For about two months after reconstitution, chimeras had very weak antihost cell-mediated lymphocytotoxicity (CML) reactivity and little third-party alloreactivity. During this time a cell population capable of suppressing CML reactivity against both host and third-party alloantigens (i.e., antigen-nonspecific) was demonstrated in chimera spleens by in vitro mixing experiments. The putative suppressor cells were Thy-1-negative and radiation-sensitive. Subsequently, mature chimeras showed host tolerance and strong third-party alloreactivity. At this point suppressor mechanisms could no longer be demonstrated. These data are consistent with a clonal elimination hypothesis in that they do not provide evidence to indicate that maintenance of specific immune tolerance is mediated by an active suppressor mechanism

  20. Ethical aspects of creating human-nonhuman chimeras capable of human gamete production and human pregnancy.

    Science.gov (United States)

    Palacios-González, César

    2015-01-01

    In this paper I explore some of the moral issues that could emerge from the creation of human-nonhuman chimeras (HNH-chimeras) capable of human gamete production and human pregnancy. First I explore whether there is a cogent argument against the creation of HNH-chimeras that could produce human gametes. I conclude that so far there is none, and that in fact there is at least one good moral reason for producing such types of creatures. Afterwards I explore some of the moral problems that could emerge from the fact that a HNH-chimera could become pregnant with a human conceptus. I focus on two sets of problems: problems that would arise by virtue of the fact that a human is gestated by a nonhuman creature, and problems that would emerge from the fact that such pregnancies could affect the health of the HNH-chimera.

  1. Infusion of donor lymphocytes into stable canine radiation chimeras: implications for mechanism of transplantation tolerance

    International Nuclear Information System (INIS)

    Canine radiation chimeras were used to investigate further mechanism(s) responsible for maintaining the stable chimeric state. In an attempt to elucidate the nature of this postulated active mechanism, the cytotoxicity of donor lymphocytes for fibroblasts of the chimera and the presence or absence of serum-blocking factors were assessed in vitro by using a cellular inhibition (CI) assay. The presence of serum-blocking factors did not protect against the development of significant GVHD in two chimeras (fatal in one). GVHD did not occur in four other chimeras after infusion of cytotoxic donor lymphocytes despite the absence of serum-blocking factors. These and previous results suggest that serum-blocking factors are not the mechanism suppressing the development of GVHD in canine radiation chimeras, and raise the possibility that a suppressor cell population may be responsible for preventing GVHD

  2. Chaotic weak chimeras and their persistence in coupled populations of phase oscillators

    Science.gov (United States)

    Bick, Christian; Ashwin, Peter

    2016-05-01

    Nontrivial collective behavior may emerge from the interactive dynamics of many oscillatory units. Chimera states are chaotic patterns of spatially localized coherent and incoherent oscillations. The recently-introduced notion of a weak chimera gives a rigorously testable characterization of chimera states for finite-dimensional phase oscillator networks. In this paper we give some persistence results for dynamically invariant sets under perturbations and apply them to coupled populations of phase oscillators with generalized coupling. In contrast to the weak chimeras with nonpositive maximal Lyapunov exponents constructed so far, we show that weak chimeras that are chaotic can exist in the limit of vanishing coupling between coupled populations of phase oscillators. We present numerical evidence that positive Lyapunov exponents can persist for a positive measure set of this inter-population coupling strength.

  3. Experimental observation of chimera and cluster states in a minimal globally coupled network

    Science.gov (United States)

    Hart, Joseph D.; Bansal, Kanika; Murphy, Thomas E.; Roy, Rajarshi

    2016-09-01

    A "chimera state" is a dynamical pattern that occurs in a network of coupled identical oscillators when the symmetry of the oscillator population is broken into synchronous and asynchronous parts. We report the experimental observation of chimera and cluster states in a network of four globally coupled chaotic opto-electronic oscillators. This is the minimal network that can support chimera states, and our study provides new insight into the fundamental mechanisms underlying their formation. We use a unified approach to determine the stability of all the observed partially synchronous patterns, highlighting the close relationship between chimera and cluster states as belonging to the broader phenomenon of partial synchronization. Our approach is general in terms of network size and connectivity. We also find that chimera states often appear in regions of multistability between global, cluster, and desynchronized states.

  4. CHICO, a heavy ion detector for Gammasphere

    CERN Document Server

    Simon, M W; Wu, C Y; Gray, R W; Teng, R; Long, C

    2000-01-01

    A 4 pi position-sensitive heavy-ion detector system, CHICO, has been developed primarily for use in conjunction with the 4 pi gamma-ray facility, Gammasphere. The CHICO detector comprises an array of 20 Parallel Plate Avalanche Counters (PPACs) covering 12 deg.

  5. Silicon detectors

    International Nuclear Information System (INIS)

    The status and recent progress of silicon detectors for high energy physics is reviewed. Emphasis is put on detectors with high spatial resolution and the use of silicon detectors in calorimeters. (orig.)

  6. A chimera embryo assay reveals a decrease in embryonic cellular proliferation induced by sperm from X-irradiated male mice

    International Nuclear Information System (INIS)

    Male mice were divided into three experimental groups and a control group. Mice in the experimental groups received one of three doses of acute X irradiation (1.73, 0.29, and 0.05 Gy) and together with the control unirradiated mice were then mated weekly to unirradiated female mice for a 9-week experimental period. Embryos were recovered from the weekly matings at the four-cell stage and examined by the chimera assay for proliferative disadvantage. Aggregation chimeras were constructed of embryos from female mice mated to irradiated males (experimental embryos) and embryos from females mated to unexposed males (control embryos) and contained either one experimental embryo and one control embryo (heterologous chimera) or two control embryos (control chimera). The control embryo in heterologous chimeras and either embryo in control chimeras were prelabeled with the vital dye fluorescein isothiocyanate (FITC), and the chimeras were cultured for 40 h and viewed under phase-contrast and epifluorescence microscopy to obtain total embryo cell number and the cellular contribution from the FITC-labeled embryo. Experimental and control embryos that were cultured singly were also examined for embryo cell number at the end of the 40-h culture period. In control chimeras, the mean ratio of the unlabeled cells:total chimera cell number (henceforth referred to as ''mean ratio'') was 0.50 with little or no weekly variation over the 9-week experimental period. During Weeks 4-7, the mean ratios of heterologous chimeras differed significantly from the mean ratio of control chimeras with the greatest differences occurring during Week 7 (0.41 for chimeras of 0.05 Gy dose group, 0.40 for chimeras of the 0.29 Gy dose group, and 0.17 for chimeras of the 1.73 Gy dose group)

  7. Chimera states in a Hodgkin-Huxley model of thermally sensitive neurons

    Science.gov (United States)

    Glaze, Tera A.; Lewis, Scott; Bahar, Sonya

    2016-08-01

    Chimera states occur when identically coupled groups of nonlinear oscillators exhibit radically different dynamics, with one group exhibiting synchronized oscillations and the other desynchronized behavior. This dynamical phenomenon has recently been studied in computational models and demonstrated experimentally in mechanical, optical, and chemical systems. The theoretical basis of these states is currently under active investigation. Chimera behavior is of particular relevance in the context of neural synchronization, given the phenomenon of unihemispheric sleep and the recent observation of asymmetric sleep in human patients with sleep apnea. The similarity of neural chimera states to neural "bump" states, which have been suggested as a model for working memory and visual orientation tuning in the cortex, adds to their interest as objects of study. Chimera states have been demonstrated in the FitzHugh-Nagumo model of excitable cells and in the Hindmarsh-Rose neural model. Here, we demonstrate chimera states and chimera-like behaviors in a Hodgkin-Huxley-type model of thermally sensitive neurons both in a system with Abrams-Strogatz (mean field) coupling and in a system with Kuramoto (distance-dependent) coupling. We map the regions of parameter space for which chimera behavior occurs in each of the two coupling schemes.

  8. MODELS FOR MOUSE CHIMERA PRODUCTION: AGGREGATION OF ES CELLS WITH CLEAVAGE STAGE EMBRYOS

    Directory of Open Access Journals (Sweden)

    STANCA CLAUDIA

    2007-01-01

    Full Text Available In a mutant ES cells↔ wild-type embryo chimera, ES cells behave more like epiblastcells. They can contribute to the primitive ectoderm layers, which give rise to all theembryonic tissues and some extraembryonic tissues (Beddington and Robertson,1989, but not to trophectoderm or primitive endoderm. Using transgenic ES celllines, aggregated with cleavage stage host embryo, ES cells can integrate randomlyin the embryo proper. If they will be take part in the formation of ICM (inner cellmass, it will be possible to obtain germline chimera animals. To generate ES cells↔ cleavage stage host embryo chimeras, we used (CD-1 mice as donors of hostembryos as well as recipients of manipulated embryos. For chimera production, weused fluorescent-labeled ES cell line (CD1/EGFP, because in this case we canfollow the fate of ES cells during the embryonic development. We produced thechimers using “aggregation chimera technique”. 8 cells stage zona pellucida free,mouse embryos were aggregated in an aggregation plates, with a clump of ES cells(10 – 15 cells. The chimera embryos were cultivated for 24 hours in the incubator(at 37 °C, 5% CO2 in air. The chimera blastocysts resulted after cultivation, weretransferred to the uterus of the 2.5-dpc pseudo pregnant females.

  9. Performance of the GRETA prototype detectors

    CERN Document Server

    Vetter, K; Lee, I Y; Clark, R M; Cromaz, M; Deleplanque, M A; Diamond, R M; Fallon, P; Lane, G J; Macchiavelli, A O; Maier, M R; Stephens, F S; Svensson, C E; Yaver, H

    2000-01-01

    A working, two-dimensionally segmented Ge detector is one of the crucial elements in the development of GRETA - a next-generation 4 pi germanium detector array that uses three-dimensional positions and energies to of individual interactions of gamma rays in the detector to reconstruct the full energies and direction vectors of the individual gamma rays by employing tracking algorithms. The three-dimensional position and the energy of interactions will be determined by using a two-dimensionally segmented Ge detector along with pulse-shape analysis of the signals. The current prototype is a 36-fold segmented HP-Ge detector in a closed-ended coaxial geometry. Preamplifiers with a compact design, low noise, and very good response properties have been built and implemented. An integrated noise level of about 5 keV has been measured for the segment channels. The average energy resolution of this detector was measured to be 1.14 and 1.93 keV at 60 and 1332 keV, respectively. Using pulse-shape analysis, a three-dimen...

  10. Protein-DNA chimeras: synthesis of two-arm chimeras and non-mechanical effects of the DNA spring

    International Nuclear Information System (INIS)

    DNA molecular springs have recently been used to control the activity of enzymes and ribozymes. In this approach, the mechanical stress exerted by the molecular spring alters the enzyme's conformation and thus the enzymatic activity. Here we describe a method alternative to our previous one to attach DNA molecular springs to proteins, where two separate DNA 'arms' are coupled to the protein and subsequently ligated. We report certain non-mechanical effects associated with the DNA spring observed in some chimeras with specific DNA sequences and the nucleotide binding enzyme guanylate kinase. If a ssDNA 'arm' is attached to the protein by one end only, we find that in some cases (depending on the DNA sequence and attachment point on the protein's surface) the unhybridized DNA arm inhibits the enzyme, while hybridization of the DNA arm leads to an apparent activation of the enzyme. One interpretation is that, in these cases, hybridization of the DNA arm removes it from the vicinity of the active site of the enzyme. We show how mechanical and non-mechanical effects of the DNA spring can be distinguished. This is important if one wants to use the protein-DNA chimeras to quantitatively study the response of the enzyme to mechanical perturbations.

  11. Immune responsiveness and incidence of reticulum cell sarcoma in long-term syngeneic radiation chimeras

    International Nuclear Information System (INIS)

    Long-term syngeneic radiation chimeras displayed a very low incidence of reticulum cell sarcoma as compared with control mice. Immune reactivity of these animals was studied in vivo by anti-dinitrophenyl antibody titer and affinity and in vitro by mitotic responsiveness to phytohemagglutinin, concanavalin A and lipopolysaccharide. Antibody titer and affinity as well as the response to T lectins were found to be increased in chimeras. These results were attributed to increased function of mature T2 cells, which could explain the reduced incidence of reticulum cell sarcoma in chimeras

  12. Developments in large gamma-ray detector arrays

    CERN Document Server

    Lee, I Y; Vetter, K

    2003-01-01

    Gamma-ray spectroscopy was revolutionized with the introduction of high energy-resolution semiconductor germanium (Ge) detectors in the early 1960s. This led to the large increase in sensitivity realized by today's arrays of Compton-suppressed Ge detectors. A still larger increase in sensitivity is expected by implementing the new concept of tracking. A tracking array consists of highly segmented Ge detectors (that can cover the full 4 pi solid-angle) in which gamma rays will be identified by measuring and tracking every gamma ray interaction. This article reviews the physics motivation for such detectors and the development of the new technologies involved. The concept of tracking is explained using the example of a proposed array called gamma-ray energy tracking array (GRETA).

  13. Contribution to data acquisition software of Eurogram and Diamant multi detectors in an Unix/VXWorks environment; Contribution aux logiciels d`acquisition de donnees des multidetecteurs Eurogam et Diamant dans un environnement reparti Unix/VXWorks

    Energy Technology Data Exchange (ETDEWEB)

    Diarra, C.

    1994-06-01

    Questions on nuclear matter, need to have new performant equipments. Eurogram is a 4 PI gamma radiations multi detector and a precious tool in gamma spectroscopy, but it is necessary to use a charged particles detector and in this aim Diamant is an Eurogram partner. These two multi detectors needed special software data acquisition systems. The whole of acquisition control and management is based on sun stations with unix system. 56 figs., 64 refs.

  14. On applications of chimera grid schemes to store separation

    Science.gov (United States)

    Cougherty, F. C.; Benek, J. A.; Steger, J. L.

    1985-01-01

    A finite difference scheme which uses multiple overset meshes to simulate the aerodynamics of aircraft/store interaction and store separation is described. In this chimera, or multiple mesh, scheme, a complex configuration is mapped using a major grid about the main component of the configuration, and minor overset meshes are used to map each additional component such as a store. As a first step in modeling the aerodynamics of store separation, two dimensional inviscid flow calculations were carried out in which one of the minor meshes is allowed to move with respect to the major grid. Solutions of calibrated two dimensional problems indicate that allowing one mesh to move with respect to another does not adversely affect the time accuracy of an unsteady solution. Steady, inviscid three dimensional computations demonstrate the capability to simulate complex configurations, including closely packed multiple bodies.

  15. Linked and knotted chimera filaments in oscillatory systems

    Science.gov (United States)

    Lau, Hon Wai; Davidsen, Jörn

    2016-07-01

    While the existence of stable knotted and linked vortex lines has been established in many experimental and theoretical systems, their existence in oscillatory systems and systems with nonlocal coupling has remained elusive. Here, we present strong numerical evidence that stable knots and links such as trefoils and Hopf links do exist in simple, complex, and chaotic oscillatory systems if the coupling between the oscillators is neither too short ranged nor too long ranged. In this case, effective repulsive forces between vortex lines in knotted and linked structures stabilize curvature-driven shrinkage observed for single vortex rings. In contrast to real fluids and excitable media, the vortex lines correspond to scroll wave chimeras [synchronized scroll waves with spatially extended (tubelike) unsynchronized filaments], a prime example of spontaneous synchrony breaking in systems of identical oscillators. In the case of complex oscillatory systems, this leads to a topological superstructure combining knotted filaments and synchronization defect sheets.

  16. Linked and knotted chimera filaments in oscillatory systems.

    Science.gov (United States)

    Lau, Hon Wai; Davidsen, Jörn

    2016-07-01

    While the existence of stable knotted and linked vortex lines has been established in many experimental and theoretical systems, their existence in oscillatory systems and systems with nonlocal coupling has remained elusive. Here, we present strong numerical evidence that stable knots and links such as trefoils and Hopf links do exist in simple, complex, and chaotic oscillatory systems if the coupling between the oscillators is neither too short ranged nor too long ranged. In this case, effective repulsive forces between vortex lines in knotted and linked structures stabilize curvature-driven shrinkage observed for single vortex rings. In contrast to real fluids and excitable media, the vortex lines correspond to scroll wave chimeras [synchronized scroll waves with spatially extended (tubelike) unsynchronized filaments], a prime example of spontaneous synchrony breaking in systems of identical oscillators. In the case of complex oscillatory systems, this leads to a topological superstructure combining knotted filaments and synchronization defect sheets.

  17. Chimera states in systems of nonlocal nonidentical phase-coupled oscillators

    Science.gov (United States)

    Xie, Jianbo; Kao, Hsien-Ching; Knobloch, Edgar

    2015-03-01

    Chimera states consisting of domains of coherently and incoherently oscillating nonlocally coupled phase oscillators in systems with spatial inhomogeneity are studied. The inhomogeneity is introduced through the dependence of the oscillator frequency on its location. Two types of spatial inhomogeneity, localized and spatially periodic, are considered and their effects on the existence and properties of multicluster and traveling chimera states are explored. The inhomogeneity is found to break up splay states, to pin the chimera states to specific locations, and to trap traveling chimeras. Many of these states can be studied by constructing an evolution equation for a complex order parameter. Solutions of this equation are in good agreement with the results of numerical simulations.

  18. Studies on the mechanism of stable graft--host tolerance in canine and human radiation chimeras

    International Nuclear Information System (INIS)

    In studies with dogs, marrow donors were immunized against their chimeras by repeated skin grafts which they rejected. Lymphocytes from chimeras and donors were tested for cell inhibition by exposure to skin fibroblasts from chimeras and donors. Results were not compatible with the concept that tolerance in radiation chimeras is maintained by serum-blocking factors. They provide circumstantial evidence against the possibility that the stable chimeric state is the result of the deletion of a close or inactivation of donor lymphocytes specifically responsive for host antigens. They are most consistent with the possibility that a suppressor-cell population is responsible for the maintenance of tolerance. Human recipients of marrow transplants were tested with the cell inhibition assay. Although the incidence of positive cell inhibition and blocking was somewhat higher than in the dog, results were not compatible with the concept that serum blocking is the sole mechanism for maintaining the stable chimeric state in human patients

  19. Status of T- and B-cell cooperation in radiation chimeras: evidence for a suppressor effect

    International Nuclear Information System (INIS)

    Absolute tolerance may not be in operation in the allogeneic bone marrow chimera, but rather a dynamic state involving interaction not only between the donor and host but also among the donor-lymphoid cells themselves may exist. Whether this observation made in one allogeneic chimera, CD2F1→ C3BF1, will be true for other chimeras (different strain combinations, species) remains to be shown. Thus, the tempo, mode, and requirement for the generation of suppressor T cells are factors that may vary for any specific allogeneic bone marrow transplant. Finally, the manner and degree to which the tolerance-inducing mechanism may affect T- and B-cell functions of the chimera with respect to third-party antigens are yet to be determined

  20. Chimera states in networks of phase oscillators: The case of two small populations

    Science.gov (United States)

    Panaggio, Mark J.; Abrams, Daniel M.; Ashwin, Peter; Laing, Carlo R.

    2016-01-01

    Chimera states are dynamical patterns in networks of coupled oscillators in which regions of synchronous and asynchronous oscillation coexist. Although these states are typically observed in large ensembles of oscillators and analyzed in the continuum limit, chimeras may also occur in systems with finite (and small) numbers of oscillators. Focusing on networks of 2 N phase oscillators that are organized in two groups, we find that chimera states, corresponding to attracting periodic orbits, appear with as few as two oscillators per group and demonstrate that for N >2 the bifurcations that create them are analogous to those observed in the continuum limit. These findings suggest that chimeras, which bear striking similarities to dynamical patterns in nature, are observable and robust in small networks that are relevant to a variety of real-world systems.

  1. Chimera states in networks of phase oscillators: The case of two small populations.

    Science.gov (United States)

    Panaggio, Mark J; Abrams, Daniel M; Ashwin, Peter; Laing, Carlo R

    2016-01-01

    Chimera states are dynamical patterns in networks of coupled oscillators in which regions of synchronous and asynchronous oscillation coexist. Although these states are typically observed in large ensembles of oscillators and analyzed in the continuum limit, chimeras may also occur in systems with finite (and small) numbers of oscillators. Focusing on networks of 2N phase oscillators that are organized in two groups, we find that chimera states, corresponding to attracting periodic orbits, appear with as few as two oscillators per group and demonstrate that for N>2 the bifurcations that create them are analogous to those observed in the continuum limit. These findings suggest that chimeras, which bear striking similarities to dynamical patterns in nature, are observable and robust in small networks that are relevant to a variety of real-world systems.

  2. Laser Chimeras as a paradigm for multi-stable patterns in complex systems

    CERN Document Server

    Larger, Laurent; Maistrenko, Yuri

    2014-01-01

    Chimera is a rich and fascinating class of self-organized solutions developed in high dimensional networks having non-local and symmetry breaking coupling features. Its accurate understanding is expected to bring important insight in many phenomena observed in complex spatio-temporal dynamics, from living systems, brain operation principles, and even turbulence in hydrodynamics. In this article we report on a powerful and highly controllable experiment based on optoelectronic delayed feedback applied to a wavelength tunable semiconductor laser, with which a wide variety of Chimera patterns can be accurately investigated and interpreted. We uncover a cascade of higher order Chimeras as a pattern transition from N to N - 1 clusters of chaoticity. Finally, we follow visually, as the gain increases, how Chimera is gradually destroyed on the way to apparent turbulence-like system behaviour.

  3. Effect of glycyrrhizin on pseudomonal skin infections in human-mouse chimeras.

    Science.gov (United States)

    Yoshida, Shohei; Lee, Jong O; Nakamura, Kiwamu; Suzuki, Sumihiro; Hendon, David N; Kobayashi, Makiko; Suzuki, Fujio

    2014-01-01

    In our previous studies, peripheral blood lineage(-)CD34(+)CD31(+) cells (CD31(+) IMC) appearing in severely burned patients have been characterized as inhibitor cells for the production of β-defensins (HBDs) by human epidermal keratinocytes (NHEK). In this study, the effect of glycyrrhizin on pseudomonal skin infections was studied in a chimera model of thermal injury. Two different chimera models were utilized. Patient chimeras were created in murine antimicrobial peptide-depleted NOD-SCID IL-2rγ(null) mice that were grafted with unburned skin tissues of severely burned patients and inoculated with the same patient peripheral blood CD31(+) IMC. Patient chimera substitutes were created in the same mice that were grafted with NHEK and inoculated with experimentally induced CD31(+) IMC. In the results, both groups of chimeras treated with glycyrrhizin resisted a 20 LD50 dose of P. aeruginosa skin infection, while all chimeras in both groups treated with saline died within 3 days of the infection. Human antimicrobial peptides were detected from the grafted site tissues of both groups of chimeras treated with glycyrrhizin, while the peptides were not detected in the same area tissues of controls. HBD-1 was produced by keratinocytes in transwell-cultures performed with CD31(+) IMC and glycyrrhizin. Also, inhibitors (IL-10 and CCL2) of HBD-1 production by keratinocytes were not detected in cultures of patient CD31(+) IMC treated with glycyrrhizin. These results indicate that sepsis stemming from pseudomonal grafted site infections in a chimera model of burn injury is controllable by glycyrrhizin. Impaired antimicrobial peptide production at the infection site of severely burned patients may be restored after treatment with glycyrrhizin. PMID:24497916

  4. Chimera states: Coexistence of coherence and incoherence in networks of coupled oscillators

    OpenAIRE

    Panaggio, Mark J; Abrams, Daniel M.

    2014-01-01

    A chimera state is a spatio-temporal pattern in a network of identical coupled oscillators in which synchronous and asynchronous oscillation coexist. This state of broken symmetry, which usually coexists with a stable spatially symmetric state, has intrigued the nonlinear dynamics community since its discovery in the early 2000s. Recent experiments have led to increasing interest in the origin and dynamics of these states. Here we review the history of research on chimera states and highlight...

  5. Chimera states in systems of nonlocal nonidentical phase-coupled oscillators

    OpenAIRE

    Xie, Jianbo; Kao, Hsien-Ching; Knobloch, Edgar

    2015-01-01

    Chimera states consisting of domains of coherently and incoherently oscillating nonlocally-coupled phase oscillators in systems with spatial inhomogeneity are studied. The inhomogeneity is introduced through the dependence of the oscillator frequency on its location. Two types of spatial inhomogeneity, localized and spatially periodic, are considered and their effects on the existence and properties of multi-cluster and traveling chimera states are explored. The inhomogeneity is found to brea...

  6. Clustering as a prerequisite for chimera states in globally coupled systems

    OpenAIRE

    Schmidt, Lennart; Krischer, Katharina

    2014-01-01

    The coexistence of coherently and incoherently oscillating parts in a system of identical oscillators with symmetrical coupling, i.e., a chimera state, is even observable with uniform global coupling. We address the question of the prerequisites for these states to occur in globally coupled systems. By analyzing two different types of chimera states found for nonlinear global coupling, we show that a clustering mechanism to split the ensemble into two groups is needed as a first step. In fact...

  7. When Nonlocal Coupling Between Oscillators Becomes Stronger: Patched Synchrony or Multi-Chimera States

    OpenAIRE

    Omelchenko, Iryna; Omel'chenko, Oleh E.; Hövel, Philipp; Schöll, Eckehard

    2012-01-01

    Systems of nonlocally coupled oscillators can exhibit complex spatio-temporal patterns, called chimera states, which consist of coexisting domains of spatially coherent (synchronized) and incoherent dynamics. We report on a novel form of these states, found in a widely used model of a limit-cycle oscillator if one goes beyond the limit of weak coupling typical for phase oscillators. Then patches of synchronized dynamics appear within the incoherent domain giving rise to a multi-chimera state....

  8. Cascades of Multi-headed Chimera States for Coupled Phase Oscillators

    OpenAIRE

    Maistrenko, Yuri L.; Vasylenko, Anna; Sudakov, Oleksandr; Levchenko, Roman; Maistrenko, Volodymyr L.

    2014-01-01

    Chimera state is a recently discovered dynamical phenomenon in arrays of nonlocally coupled oscillators, that displays a self-organized spatial pattern of co-existing coherence and incoherence. We discuss the appearance of the chimera states in networks of phase oscillators with attractive and with repulsive interactions, i.e. when the coupling respectively favors synchronization or works against it. By systematically analyzing the dependence of the spatiotemporal dynamics on the level of cou...

  9. TCP: a tool for designing chimera proteins based on the tertiary structure information

    OpenAIRE

    Nishida Reina; Yoneya Takashi

    2009-01-01

    Abstract Background Chimera proteins are widely used for the analysis of the protein-protein interaction region. One of the major issues is the epitope analysis of the monoclonal antibody. In the analysis, a continuous portion of an antigen is sequentially substituted into a different sequence. This method works well for an antibody recognizing a linear epitope, but not for that recognizing a discontinuous epitope. Although the designing the chimera proteins based on the tertiary structure in...

  10. Characteristic distribution of finite-time Lyapunov exponents for chimera states

    OpenAIRE

    André E. Botha

    2016-01-01

    Our fascination with chimera states stems partially from the somewhat paradoxical, yet fundamental trait of identical, and identically coupled, oscillators to split into spatially separated, coherently and incoherently oscillating groups. While the list of systems for which various types of chimeras have already been detected continues to grow, there is a corresponding increase in the number of mathematical analyses aimed at elucidating the fundamental reasons for this surprising behaviour. B...

  11. Application of a Chimera Full Potential Algorithm for Solving Aerodynamic Problems

    Science.gov (United States)

    Holst, Terry L.; Kwak, Dochan (Technical Monitor)

    1997-01-01

    A numerical scheme utilizing a chimera zonal grid approach for solving the three dimensional full potential equation is described. Special emphasis is placed on describing the spatial differencing algorithm around the chimera interface. Results from two spatial discretization variations are presented; one using a hybrid first-order/second-order-accurate scheme and the second using a fully second-order-accurate scheme. The presentation is highlighted with a number of transonic wing flow field computations.

  12. Observation and characterization of chimera states in coupled dynamical systems with nonlocal coupling

    OpenAIRE

    Gopal, R; Chandrasekar, V. K.; Venkatesan, A.; Lakshmanan, M.

    2014-01-01

    By developing the concepts of strength of incoherence and discontinuity measure, we show that a distinct quantitative characterization of chimera and multichimera states which occur in networks of coupled nonlinear dynamical systems admitting nonlocal interactions of finite radius can be made. These measures also clearly distinguish between chimera or multichimera states (both stable and breathing types) and coherent and incoherent as well as cluster states....

  13. Chimera-like states in an ensemble of globally coupled oscillators

    OpenAIRE

    Yeldesbay, Azamat; Pikovsky, Arkady; Rosenblum, Michael

    2014-01-01

    We demonstrate emergence of a complex state in a homogeneous ensemble of globally coupled identical oscillators, reminiscent of chimera states in locally coupled oscillator lattices. In this regime some part of the ensemble forms a regularly evolving cluster, while all other units irregularly oscillate and remain asynchronous. We argue that chimera emerges because of effective bistability which dynamically appears in the originally monostable system due to internal delayed feedback in individ...

  14. Robustness of chimera states for coupled FitzHugh-Nagumo oscillators

    OpenAIRE

    Omelchenko, Iryna; Provata, Astero; Hizanidis, Johanne; Schoell, Eckehard; Hoevel, Philipp

    2014-01-01

    Chimera states are complex spatio-temporal patterns that consist of coexisting domains of spatially coherent and incoherent dynamics. This counterintuitive phenomenon was first observed in systems of identical oscillators with symmetric coupling topology. Can one overcome these limitations? To address this question, we discuss the robustness of chimera states in networks of FitzHugh-Nagumo oscillators. Considering networks of inhomogeneous elements with regular coupling topology, and networks...

  15. Greengenes: Chimera-checked 16S rRNA gene database and workbenchcompatible in ARB

    Energy Technology Data Exchange (ETDEWEB)

    DeSantis, T.Z.; Hugenholtz, P.; Larsen, N.; Rojas, M.; Brodie,E.L; Keller, K.; Huber, T.; Dalevi, D.; Hu, P.; Andersen, G.L.

    2006-02-01

    A 16S rRNA gene database (http://greengenes.lbl.gov) addresses limitations of public repositories by providing chimera-screening, standard alignments and taxonomic classification using multiple published taxonomies. It was revealed that incongruent taxonomic nomenclature exists among curators even at the phylum-level. Putative chimeras were identified in 3% of environmental sequences and 0.2% of records derived from isolates. Environmental sequences were classified into 100 phylum-level lineages within the Archaea and Bacteria.

  16. Effect of glycyrrhizin on pseudomonal skin infections in human-mouse chimeras.

    Directory of Open Access Journals (Sweden)

    Shohei Yoshida

    Full Text Available In our previous studies, peripheral blood lineage(-CD34(+CD31(+ cells (CD31(+ IMC appearing in severely burned patients have been characterized as inhibitor cells for the production of β-defensins (HBDs by human epidermal keratinocytes (NHEK. In this study, the effect of glycyrrhizin on pseudomonal skin infections was studied in a chimera model of thermal injury. Two different chimera models were utilized. Patient chimeras were created in murine antimicrobial peptide-depleted NOD-SCID IL-2rγ(null mice that were grafted with unburned skin tissues of severely burned patients and inoculated with the same patient peripheral blood CD31(+ IMC. Patient chimera substitutes were created in the same mice that were grafted with NHEK and inoculated with experimentally induced CD31(+ IMC. In the results, both groups of chimeras treated with glycyrrhizin resisted a 20 LD50 dose of P. aeruginosa skin infection, while all chimeras in both groups treated with saline died within 3 days of the infection. Human antimicrobial peptides were detected from the grafted site tissues of both groups of chimeras treated with glycyrrhizin, while the peptides were not detected in the same area tissues of controls. HBD-1 was produced by keratinocytes in transwell-cultures performed with CD31(+ IMC and glycyrrhizin. Also, inhibitors (IL-10 and CCL2 of HBD-1 production by keratinocytes were not detected in cultures of patient CD31(+ IMC treated with glycyrrhizin. These results indicate that sepsis stemming from pseudomonal grafted site infections in a chimera model of burn injury is controllable by glycyrrhizin. Impaired antimicrobial peptide production at the infection site of severely burned patients may be restored after treatment with glycyrrhizin.

  17. Cell surface appearance of unexpected host MHC determinants on thymocytes from radiation bone marrow chimeras

    International Nuclear Information System (INIS)

    The phenotypic appearance of cell surface antigens on murine thymocytes from long-term radiation bone marrow chimeras was analyzed using indirect immunofluorescence and flow microfluorometry. Cells maturing in the thymi of these mice were typed for MHC (Kk, I-Ak, H-2b, Kb, and Ib) and non-MHC (Lty 1, Ly 9, and TL) determinants. All cells were of donor origin as determined by non-MHC (Ly) phenotype in P1 leads to P2, P1 x P2 leads to P1, and P1 leads to P2 radiation chimeras. In contrast, the MHC phenotypes of these thymocytes were markedly affected by the host environment. Specifically, H-2 and I-A determinants of both parental phenotypes were detected on thymocytes from P1 leads to P1 x P2 chimeras; I-A determinants of host phenotype were present, whereas I-A determinants of donor phenotype were reduced on thymocytes from P1 x P2 leads to P1 chimeras; and thymocytes from P1 leads to P2 chimeras possessed H-2 and I-A determinants of host phenotype but showed reduction of donor I-A phenotype determinants. The appearance of host cell surface H-2 and I-A determinants on thymocytes from chimeras closely parallels the functional recognition of MHC determinants by T cells from chimeric mice and thus may be significantly related to the development of the self-recognition repertoire by maturing T cells

  18. TCP: a tool for designing chimera proteins based on the tertiary structure information

    Directory of Open Access Journals (Sweden)

    Nishida Reina

    2009-01-01

    Full Text Available Abstract Background Chimera proteins are widely used for the analysis of the protein-protein interaction region. One of the major issues is the epitope analysis of the monoclonal antibody. In the analysis, a continuous portion of an antigen is sequentially substituted into a different sequence. This method works well for an antibody recognizing a linear epitope, but not for that recognizing a discontinuous epitope. Although the designing the chimera proteins based on the tertiary structure information is required in such situations, there is no appropriate tool so far. Results In light of the problem, we developed a tool named TCP (standing for a Tool for designing Chimera Proteins, which extracts some sets of mutually orthogonal cutting surfaces for designing chimera proteins using a genetic algorithm. TCP can also incorporate and consider the solvent accessible surface area information calculated by a DSSP program. The test results of our method indicate that the TCP is robust and applicable to various shapes of proteins. Conclusion We developed TCP, a tool for designing chimera proteins based on the tertiary structure information. TCP is robust and possesses several favourable features, and we believe it is a useful tool for designing chimera proteins. TCP is freely available as an additional file of this manuscript for academic and non-profit organization.

  19. Four-cluster chimera state in non-locally coupled phase oscillator systems with an external potential

    International Nuclear Information System (INIS)

    Dynamics of a one-dimensional array of non-locally coupled Kuramoto phase oscillators with an external potential is studied. A four-cluster chimera state is observed for the moderate strength of the external potential. Different from the clustered chimera states studied before, the instantaneous frequencies of the oscillators in a synchronized cluster are different in the presence of the external potential. As the strength of the external potential increases, a bifurcation from the two-cluster chimera state to the four-cluster chimera states can be found. These phenomena are well predicted analytically with the help of the Ott—Antonsen ansatz. (general)

  20. Infrared detectors

    CERN Document Server

    Rogalski, Antonio

    2010-01-01

    This second edition is fully revised and reorganized, with new chapters concerning third generation and quantum dot detectors, THz detectors, cantilever and antenna coupled detectors, and information on radiometry and IR optics materials. Part IV concerning focal plane arrays is significantly expanded. This book, resembling an encyclopedia of IR detectors, is well illustrated and contains many original references … a really comprehensive book.-F. Sizov, Institute of Semiconductor Physics, National Academy of Sciences, Kiev, Ukraine

  1. A new detector for low P[sub 1] physics

    Energy Technology Data Exchange (ETDEWEB)

    Da Via, C.; Mondardini, M.R.; Orear, J. (Lab. of Nuclear Studies, Univ. Ithaca, NY (United States)); DeSalvo, R. (CERN, LAA, Geneva (Switzerland)); Lundin, M. (Lab. of Nuclear Studies, Univ. Ithaca, NY (United States) World Lab., Lausanne (Switzerland)); Shimizu, T.; Shinji, O. (Kurary International Corp., Tokyo (Japan))

    1992-12-01

    Elastic pp (or panti p) scattering at microradian angles provides a measurement of the total pp (or panti p) cross section, the slope of the elastic scattering cross section with t (the square of the momentum transfer) and the ratio of real to imaginary scattering amplitudes, as well as an absolute luminosity calibration. A detector is proposed which can measure elastic scattering and small angle processes which are usually missed by a typical 4[pi] detector. The detector consists of a bundle of scintillating fibers. Images from these fibers are transported via glass fiber optics and intensified with two proximity focused image intensifiers. Images are then reduced via an image taper and read out with a charge coupled device (CCD). (orig.).

  2. CXCR4-PI3KⅢ-自噬轴与结肠癌LoVo细胞转移潜能相关性研究%Relationship of CXCR4-PI3KⅢ-autophagy axis and LoVo cell migration and invasion

    Institute of Scientific and Technical Information of China (English)

    王天宝; 石汉平; 韩方海; 董文广

    2013-01-01

    目的:探讨调控CXCR4-PI3KⅢ-自噬轴对结直肠癌LoVo细胞迁移和侵袭能力的影响.方法:实验分为正常LoVo细胞组、介导CXCR4-RNAi慢病毒转染LoVo细胞组(CXCR4-RNAi组)和无意义慢病毒转染LoVo细胞组(NC组).采用Q-PCR检测PI3KⅢmRNA表达,蛋白质印迹法检测PI3KⅢ、LC3-Ⅱ及Beclin l的表达,激光共聚焦显微镜观察绿色荧光颗粒,透射电镜观察自噬溶酶体,Transwell小室评价LoVo细胞迁移与侵袭能力.结果:PI3KⅢmRNA表达量正常LoVo细胞组为1.09±0.11,NC组为1.07±0.25,CXCR4-RNAi组为0.86±0.06.PI3KⅢ相对表达量CXCR4-RNAi组为0.227±0.023,低于正常LoVo细胞组的0.607±0.012(P<0.001)和NC组的0.667±0.040(P<0.001),正常LoVo细胞组和NC组差异无统计学意义,P=0.310.LC3-Ⅱ相对表达量CXCR4-RNAi组为0.083±0.012,低于正常LoVo细胞组的0.233±0.015(P<0.001)和NC组的0.253±0.020(P<0.001),正常LoVo细胞组和NC组差异无统计学意义,P=0.184.Beclin 1相对表达量CXCR4-RNAi组为0.207±0.012,低于正常LoVo细胞组的0.440±0.053(P=0.134)和NC组的0.650±0.252,P=0.011.绿色荧光颗粒和自噬溶酶体数量正常LoVo细胞组和NC组明显多于CXCR4-RNAi组.CXCR4-RNAi组迁移实验细胞计数(87.7±9.1)低于正常LoVo细胞组的126.3±4.9(P=0.009)和NC组的115.0±18.7(P=0.035).CXCR4-RNAi组侵袭实验细胞计数(88.7±10.5)低于正常LoVo细胞组的109.7±4.7 (P=0.019)和NC组的107.7±8.1,P=0.029.结论:CXCR4 PI3KⅢ自噬轴可调控结肠癌Lo-Vo细胞自噬状态,影响肿瘤细胞迁移和浸润,可能是恶性肿瘤浸润转移的机制之一.

  3. Immune competence of splenic lymphocytes following graft-vs-host disease in mouse allogeneic radiation chimeras

    International Nuclear Information System (INIS)

    The abnormal immune response of long-term mouse allogeneic chimeras is reflected by qualitative deficiencies in either T or B lymphocytes. The present study was undertaken to determine if a relationship existed between the severity of graft-vs-host disease (GVHD) that these animals had experienced and a functional defect in either the T or B cell population. The in vitro PFC response of chimera spleen cells to sheep red blood cells (SRBC) was evaluated in the presence of normal T or B lymphocytes 4 to 8 months after marrow transplantation and well beyond the GVHD period. In an analysis of several different allogeneic radiation chimeras, our results showed no relationship between the severity of GVHD experienced and the immunologic capacity of either T or B cells. Thus, different chimera combinations showing similar degrees of GVHD were functionally deficient in one or the other of these two cells types or both with no apparent predilection for abnormality in either population. In examining the quantitative in vitro PFC response to sheep RBC by spleen cells from individual chimeras, we found that the number of PFC formed was related to the severity of GVHD experienced by that animal. A general relationship between severity of GVHD and PFC capacity may also exist between chimeras of different genetic combinations. However, this relationship is not precise since gross exceptions occur. Our results, although documenting further the qualitative abnormalities in T and/or B lymphocytes of radiation chimeras, do not reveal the factor or mechanisms by which these cells are made unresponsive. It is suggested that the tolerance-inducing mechanism of these animals, whether it be humoral blocking factors or suppressor cells, is in some way interfering with the collaboration of T and B cells for antibody production

  4. Human-animal chimeras for vaccine development: an endangered species or opportunity for the developing world?

    Directory of Open Access Journals (Sweden)

    Daar Abdallah S

    2010-05-01

    Full Text Available Abstract Background In recent years, the field of vaccines for diseases such as Human Immunodeficiency Virus (HIV which take a heavy toll in developing countries has faced major failures. This has led to a call for more basic science research, and development as well as evaluation of new vaccine candidates. Human-animal chimeras, developed with a 'humanized' immune system could be useful to study infectious diseases, including many neglected diseases. These would also serve as an important tool for the efficient testing of new vaccine candidates to streamline promising candidates for further trials in humans. However, developing human-animal chimeras has proved to be controversial. Discussion Development of human-animal chimeras for vaccine development has been slowed down because of opposition by some philosophers, ethicists and policy makers in the west-they question the moral status of such animals, and also express discomfort about transgression of species barriers. Such opposition often uses a contemporary western world view as a reference point. Human-animal chimeras are often being created for diseases which cause significantly higher morbidity and mortality in the developing world as compared to the developed world. We argue in our commentary that given this high disease burden, we should look at socio-cultural perspectives on human-animal chimera like beings in the developing world. On examination, it's clear that such beings have been part of mythology and cultural descriptions in many countries in the developing world. Summary To ensure that important research on diseases afflicting millions like malaria, HIV, Hepatitis-C and dengue continues to progress, we recommend supporting human-animal chimera research for vaccine development in developing countries (especially China and India which have growing technical expertise in the area. The negative perceptions in some parts of the west about human-animal chimeras can be used as an

  5. Black Box Chimera Check (B2C2): a Windows-Based Software for Batch Depletion of Chimeras from Bacterial 16S rRNA Gene Datasets.

    Science.gov (United States)

    Gontcharova, Viktoria; Youn, Eunseog; Wolcott, Randall D; Hollister, Emily B; Gentry, Terry J; Dowd, Scot E

    2010-01-01

    The existing chimera detection programs are not specifically designed for "next generation" sequence data. Technologies like Roche 454 FLX and Titanium have been adapted over the past years especially with the introduction of bacterial tag-encoded FLX/Titanium amplicon pyrosequencing methodologies to produce over one million 250-600 bp 16S rRNA gene reads that need to be depleted of chimeras prior to downstream analysis. Meeting the needs of basic scientists who are venturing into high-throughput microbial diversity studies such as those based upon pyrosequencing and specifically providing a solution for Windows users, the B2C2 software is designed to be able to accept files containing large multi-FASTA formatted sequences and screen for possible chimeras in a high throughput fashion. The graphical user interface (GUI) is also able to batch process multiple files. When compared to popular chimera screening software the B2C2 performed as well or better while dramatically decreasing the amount of time required generating and screening results. Even average computer users are able to interact with the Windows .Net GUI-based application and define the stringency to which the analysis should be done. B2C2 may be downloaded from http://www.researchandtesting.com/B2C2. PMID:21339894

  6. DNA immunization with plasmids expressing hCGbeta-chimeras.

    Science.gov (United States)

    Terrazzini, Nadia; Hannesdóttir, Sólveig; Delves, Peter J; Lund, Torben

    2004-06-01

    Human chorionic gonadotropin has been used as an anti-fertility vaccine and as a target for cancer immunotherapy. We have explored the use of DNA immunization with the aim of improving the immunogenicity of this hormone. Stimulating the muscle with electric pulses following intramuscular injection of plasmids expressing hCGbeta resulted in higher levels of human chorionic gonadotropin (hCG)-specific antibodies, which could be further enhanced following a protein boost with hCG mixed with adjuvant. DNA vaccines encoding a membrane attached or a secreted form of hCGbeta produced similar-albeit relatively modest-antibody responses. Providing hCGbeta with additional T cell help by vaccinating with a plasmid encoding a hCGbeta-hFc fusion protein did not further increase the antibody levels in the immunized animals. However, immunization of mice with a construct encoding hCGbeta fused to C3d(3) produced significantly lower antibody levels relative to mice immunized with the hCGbeta-alone expression plasmid, even though the hCGbeta-C3d(3) chimera was expected to facilitate cross-linking of the antigen-specific B-cell receptor and CR2 thereby lowering the threshold of activation. Thus the limiting factor determining the antibody levels following hCGbeta immunization, at least for DNA immunization, is related to the amount of protein available rather than the form of protein produced or lack of T cell epitopes. PMID:15149771

  7. Generation of an adenovirus-parvovirus chimera with enhanced oncolytic potential.

    Science.gov (United States)

    El-Andaloussi, Nazim; Bonifati, Serena; Kaufmann, Johanna K; Mailly, Laurent; Daeffler, Laurent; Deryckère, François; Nettelbeck, Dirk M; Rommelaere, Jean; Marchini, Antonio

    2012-10-01

    In this study, our goal was to generate a chimeric adenovirus-parvovirus (Ad-PV) vector that combines the high-titer and efficient gene transfer of adenovirus with the anticancer potential of rodent parvovirus. To this end, the entire oncolytic PV genome was inserted into a replication-defective E1- and E3-deleted Ad5 vector genome. As we found that parvoviral NS expression inhibited Ad-PV chimera production, we engineered the parvoviral P4 early promoter, which governs NS expression, by inserting into its sequence tetracycline operator elements. As a result of these modifications, P4-driven expression was blocked in the packaging T-REx-293 cells, which constitutively express the tetracycline repressor, allowing high-yield chimera production. The chimera effectively delivered the PV genome into cancer cells, from which fully infectious replication-competent parvovirus particles were generated. Remarkably, the Ad-PV chimera exerted stronger cytotoxic activities against various cancer cell lines, compared with the PV and Ad parental viruses, while being still innocuous to a panel of tested healthy primary human cells. This Ad-PV chimera represents a novel versatile anticancer agent which can be subjected to further genetic manipulations in order to reinforce its enhanced oncolytic capacity through arming with transgenes or retargeting into tumor cells.

  8. Title: Chimeras in small, globally coupled networks: Experiments and stability analysis

    Science.gov (United States)

    Hart, Joseph D.; Bansal, Kanika; Murphy, Thomas E.; Roy, Rajarshi

    Since the initial observation of chimera states, there has been much discussion of the conditions under which these states emerge. The emphasis thus far has mainly been to analyze large networks of coupled oscillators; however, recent studies have begun to focus on the opposite limit: what is the smallest system of coupled oscillators in which chimeras can exist? We experimentally observe chimeras and other partially synchronous patterns in a network of four globally-coupled chaotic opto-electronic oscillators. By examining the equations of motion, we demonstrate that symmetries in the network topology allow a variety of synchronous states to exist, including cluster synchronous states and a chimera state. Using the group theoretical approach recently developed for analyzing cluster synchronization, we show how to derive the variational equations for these synchronous patterns and calculate their linear stability. The stability analysis gives good agreement with our experimental results. Both experiments and simulations suggest that these chimera states often appear in regions of multistability between global, cluster, and desynchronized states.

  9. Chimera and phase-cluster states in populations of coupled chemical oscillators

    Science.gov (United States)

    Tinsley, Mark R.; Nkomo, Simbarashe; Showalter, Kenneth

    2012-09-01

    Populations of coupled oscillators may exhibit two coexisting subpopulations, one with synchronized oscillations and the other with unsynchronized oscillations, even though all of the oscillators are coupled to each other in an equivalent manner. This phenomenon, discovered about ten years ago in theoretical studies, was then further characterized and named the chimera state after the Greek mythological creature made up of different animals. The highly counterintuitive coexistence of coherent and incoherent oscillations in populations of identical oscillators, each with an equivalent coupling structure, inspired great interest and a flurry of theoretical activity. Here we report on experimental studies of chimera states and their relation to other synchronization states in populations of coupled chemical oscillators. Our experiments with coupled Belousov-Zhabotinsky oscillators and corresponding simulations reveal chimera behaviour that differs significantly from the behaviour found in theoretical studies of phase-oscillator models.

  10. Allogeneic unresponsiveness to orthotopic cardiac transplants in DL-A-identical radiation chimeras

    International Nuclear Information System (INIS)

    Nine Cooperstown beagles of known DL-A genotypes were exposed to supralethal total-body irradiation and received bone-marrow allografts from DL-A-identical donors. Four to 5 months later, the resulting chimeras received orthotopic cardiac allografts from their corresponding donors of marrow. Six chimeras died of operative complications in the immediate postoperative period. The other 3 chimeras survived from 173 to 547 days; 1 dog died at 173 days as a result of right-sided heart failure, secondary to stenosis at the site of the pulmonary artery anastomosis. The other two recipients continue to be active and healthy at 545 and 547 days. The results indicate that dogs can be rendered specifically tolerant to orthotopic cardiac allografts by supralethal total-body irradiation and the transplantation of marrow obtained from the prospective allograft donor

  11. A Multitier System for the Verification, Visualization and Management of CHIMERA

    International Nuclear Information System (INIS)

    CHIMERA is a multi-dimensional radiation hydrodynamics code designed to study core-collapse supernovae. The code is made up of three essentially independent parts: a hydrodynamics module, a nuclear burning module, and a neutrino transport solver combined within an operator-split approach. Given CHIMERA's complexity and pace of ongoing development, a new support system, Bellerophon, has been designed and implemented to perform automated verification, visualization and management tasks while integrating with other workflow systems utilized by CHIMERA's development group. In order to achieve these goals, a multitier approach has been adopted. By integrating supercomputing platforms, visualization clusters, a dedicated web server and a client-side desktop application, this system attempts to provide an encapsulated, end-to-end solution to these needs.

  12. Experimental investigation of chimera states with quiescent and synchronous domains in coupled electronic oscillators.

    Science.gov (United States)

    Gambuzza, Lucia Valentina; Buscarino, Arturo; Chessari, Sergio; Fortuna, Luigi; Meucci, Riccardo; Frasca, Mattia

    2014-09-01

    Chimera states, that is, dynamical regimes characterized by the existence of a symmetry-broken solution where a coherent domain and an incoherent one coexist, have been theoretically demonstrated and numerically found in networks of homogeneously coupled identical oscillators. In this work we experimentally investigate the behavior of a closed and an open chain of electronic circuits with neuron-like spiking dynamics and first neighbor connections. Experimental results show the onset of a regime that we call chimera states with quiescent and synchronous domains, where synchronization coexists with spatially patterned oscillation death. The whole experimental bifurcation scenario, showing how disordered states, synchronization, chimera states with quiescent and synchronous domains, and oscillatory death states emerge as coupling is varied, is presented.

  13. The Chimera II Real-Time Operating System for advanced sensor-based control applications

    Science.gov (United States)

    Stewart, David B.; Schmitz, Donald E.; Khosla, Pradeep K.

    1992-01-01

    Attention is given to the Chimera II Real-Time Operating System, which has been developed for advanced sensor-based control applications. The Chimera II provides a high-performance real-time kernel and a variety of IPC features. The hardware platform required to run Chimera II consists of commercially available hardware, and allows custom hardware to be easily integrated. The design allows it to be used with almost any type of VMEbus-based processors and devices. It allows radially differing hardware to be programmed using a common system, thus providing a first and necessary step towards the standardization of reconfigurable systems that results in a reduction of development time and cost.

  14. Chimera states in a population of identical oscillators under planar cross-coupling

    Indian Academy of Sciences (India)

    C R Hens; A Mishra; P K Roy; A Sen; S K Dana

    2015-02-01

    We report the existence of chimera states in an assembly of identical nonlinear oscillators that are globally linked to each other in a simple planar cross-coupled form. The rotational symmetry breaking of the coupling term appears to be responsible for the emergence of these collective states that display a characteristic coexistence of coherent and incoherent behaviour. The finding, observed in both a collection of van der Pol oscillators and chaotic Rössler oscillators, further simplifies the existence criterion for chimeras, thereby broadens the range of their applicability to real-world situations.

  15. Marginal chimera state at cross-frequency locking of pulse-coupled neural networks

    Science.gov (United States)

    Bolotov, M. I.; Osipov, G. V.; Pikovsky, A.

    2016-03-01

    We consider two coupled populations of leaky integrate-and-fire neurons. Depending on the coupling strength, mean fields generated by these populations can have incommensurate frequencies or become frequency locked. In the observed 2:1 locking state of the mean fields, individual neurons in one population are asynchronous with the mean fields, while in another population they have the same frequency as the mean field. These synchronous neurons form a chimera state, where part of them build a fully synchronized cluster, while other remain scattered. We explain this chimera as a marginal one, caused by a self-organized neutral dynamics of the effective circle map.

  16. In vitro induction of mutation and separation of chimeras in Gerbera jamesonii

    International Nuclear Information System (INIS)

    Using ex vitro leaves as objects to be irradiated and to induce variation in sixteen Gerbera jamesonii cultivars, reproduced from adventitious buds, resulted in obtaining the mutants which inflorescence color was uniformly changed and which newly acquired traits recurred in the second generation of plants reproduced vegetatively from the isolated shoot tips. However, chimeras appeared among the vM1 plants exposed to various doses of gamma rays (5-25 Gy and they constituted almost half of the mutated plants. A further propagation of chimeras from leaf explants forming adventitious shoots significantly increased the number of solid mutants with uniformly changed inflorescence color in the vM1 generation. (author)

  17. Induction of chlorophyll chimeras and chlorophyll mutations in mungbean (Vigna radiata) cv. T44

    International Nuclear Information System (INIS)

    Uniform and healthy seeds of mungbean (Vigna radiata) cv. T44 were exposed to varying doses of gamma rays, ethyl methane sulphonate (EMS) and combination treatment of gamma rays with EMS. The data were recorded for seed germination, plant survival, frequency and spectrum of chlorophyll chimeras in M1 and chlorophyll mutations in M2 generation. Among all, the combination treatments were found most effective for inducing chlorophyll chimeras and chlorophyll mutations than the gamma rays or EMS alone. Of the mutants under reference, the albino, xantha and chlorina showed monogenic recessive while viridis exhibited digenic recessive inheritance. (author). 8 refs., 2 tabs

  18. Hemopoietic precursor-cells in radiation chimeras restored by bone marrow of adult thymectomized mice

    International Nuclear Information System (INIS)

    Radioprotective capacity of bone marrow CFUs of adult thymectomized mice was studied. Lethaly irradiated mice were inoculated with bone marrow of mice thymectomized 8-11 months before. The colony forming capacity and proliferative rate of CFUs were studied 1-7.5 months after obtaining the radiation chimeras. It has been shown that proliferative capacity of bone marrow of adult thymectomized mice was reduced in comparison with that of normal animals. We also found that the content of CFUs in bone of those chimeras was reduced later - after 7.5 months. In this period (1-7.5 months) the cellularity of bone marrow did not change

  19. Application of Chimera Grid Scheme to Combustor Flowfields at all Speeds

    Science.gov (United States)

    Yungster, Shaye; Chen, Kuo-Huey

    1997-01-01

    A CFD method for solving combustor flowfields at all speeds on complex configurations is presented. The approach is based on the ALLSPD-3D code which uses the compressible formulation of the flow equations including real gas effects, nonequilibrium chemistry and spray combustion. To facilitate the analysis of complex geometries, the chimera grid method is utilized. To the best of our knowledge, this is the first application of the chimera scheme to reacting flows. In order to evaluate the effectiveness of this numerical approach, several benchmark calculations of subsonic flows are presented. These include steady and unsteady flows, and bluff-body stabilized spray and premixed combustion flames.

  20. A PTAS for the Classical Ising Spin Glass Problem on the Chimera Graph Structure

    OpenAIRE

    Saket, Rishi

    2013-01-01

    We present a polynomial time approximation scheme (PTAS) for the minimum value of the classical Ising Hamiltonian with linear terms on the Chimera graph structure as defined in the recent work of McGeoch and Wang. The result follows from a direct application of the techniques used by Bansal, Bravyi and Terhal who gave a PTAS for the same problem on planar and, in particular, grid graphs. We also show that on Chimera graphs, the trivial lower bound is within a constant factor of the optimum.

  1. SLC45A3-ELK4 Chimera in Prostate Cancer: Spotlight on Cis-Splicing

    OpenAIRE

    Kumar-Sinha, Chandan; Kalyana-Sundaram, Shanker; Chinnaiyan, Arul M.

    2012-01-01

    Using a series of detailed experiments, Zhang et al establish that the prostate cancer RNA chimera SLC45A3-ELK4 is generated by cis-splicing between the two adjacent genes and does not involve DNA rearrangements or trans-splicing. The chimera expression is induced by androgen treatment likely by overcoming the read-through block imposed by the intergenic CCCTC-insulators bound by CTCF repressor protein. The chimeric transcript, but not wild type ELK4, is shown to augment prostate cancer cell ...

  2. Chimera states: coexistence of coherence and incoherence in networks of coupled oscillators

    Science.gov (United States)

    Panaggio, Mark J.; Abrams, Daniel M.

    2015-03-01

    A chimera state is a spatio-temporal pattern in a network of identical coupled oscillators in which synchronous and asynchronous oscillation coexist. This state of broken symmetry, which usually coexists with a stable spatially symmetric state, has intrigued the nonlinear dynamics community since its discovery in the early 2000s. Recent experiments have led to increasing interest in the origin and dynamics of these states. Here we review the history of research on chimera states and highlight major advances in understanding their behaviour.

  3. Optical Detectors

    Science.gov (United States)

    Tabbert, Bernd; Goushcha, Alexander

    Optical detectors are applied in all fields of human activities from basic research to commercial applications in communication, automotive, medical imaging, homeland security, and other fields. The processes of light interaction with matter described in other chapters of this handbook form the basis for understanding the optical detectors physics and device properties.

  4. Antiviral T cell competence and restriction specificity of mixed allogeneic (P1 + P2----P1) irradiation chimeras

    International Nuclear Information System (INIS)

    Mixed irradiation bone marrow chimeras were prepared by reconstituting lethally irradiated C57BL/10 (B10) or B10.D2 mice with T cell-depleted bone marrow cells of B10 plus B10.D2 origin. These chimeras were healthy and survived well under conventional housing conditions and after experimental laboratory infections. Of a total of 17 chimeras tested, 2 died spontaneously or from the injected virus. Twelve of fifteen chimeras mounted a measurable cytotoxic T cell response to virus. Despite approximately equal percentages of B10 and B10.D2 lymphocytes in chimeras, cytotoxic T cell responses to vaccinia virus and lymphocytic choriomeningitis virus were mediated variably by either syngeneic or allogeneic donor lymphocytes; thus the H-2 type of effector T cells frequently did not correspond to the 50:50 distribution of spleen or peripheral blood lymphocytes. Cytotoxic responses were restricted exclusively to recipient H-2 type. All mixed chimeras examined were able to mount a good IgG response to vesicular stomatitis virus. These results confirm previous data suggesting that such mixed chimeras are healthy and immunocompetent and demonstrate strict recipient-determined restriction specificity of effector T cells; they also suggest that if T help is necessary for induction of virus-specific cytotoxic T cells, it does not require host-restricted interactions between helper T cells and precursor cytotoxic T cells

  5. "American Chimera: The Ever-Present Domination of Whiteness, Patriarchy, and Capitalism…A Parable"

    Science.gov (United States)

    Montoya, Roberto; Matias, Cheryl E.; Nishi, Naomi W. M.; Sarcedo, Geneva L.

    2016-01-01

    In Greek mythology, the Chimera is a fire-breathing monster with three heads: one of a lion, one of a horned goat, and one of a powerful dragon. Of similar construction is the presence of three structures in US society, whiteness, patriarchy, and capitalism, which are overwhelmingly represented, valued, and espoused when examining areas of…

  6. Application of the Chimera overlapped grid scheme to simulation of Space Shuttle ascent flows

    Science.gov (United States)

    Buning, Pieter G.; Parks, Steven J.; Chan, William M.; Renze, Kevin J.

    1992-01-01

    Several issues relating to the application of Chimera overlapped grids to complex geometries and flowfields are discussed. These include the addition of geometric components with different grid topologies, gridding for intersecting pieces of geometry, and turbulence modeling in grid overlap regions. Sample results are presented for transonic flow about the Space Shuttle launch vehicle. Comparisons with wind tunnel and flight measured pressures are shown.

  7. Influence of Lymphopoiesis Control Mechanisms on the Recovery of Immune Capacities in Isogenic Radiation Chimeras

    International Nuclear Information System (INIS)

    The capacities of cells belonging either to foetal liver or to adult bone marrow or spleen are extremely different as far as the production of immunologically competent cells (ICC) by isogenic chimeras is concerned. The study of thymectomized radiation chimeras by the Simonsen test and the Jern technique shows that it is only the spleen or the lymph nodes which are able to bring ICC to a thymectomized animal; the bone marrow and the foetal liver carry only precursor cells which cannot be transformed into ICC when the recipient lacks its thymus. Furthermore, the functional ICC brought to these animals by the spleen cell suspensions have limited life span, not exceeding 300- 400 days. It must also be stressed that the thymectomized isogenic chimeras treated by bone marrow or foetal liver, although they display no immune reactivity, have an increased production of immunoglobulins. Therefore it seems that in this case there is no regulation of the production, differentiation and maturation of ICC. However, a control of the production and/or reactivity of ICC does exist in non-thymectomized radiation chimeras. This can be shown by the Simonsen test and the Jern technique for the primary reactions and by the study of homologous tumour graft rejection for the second-set reaction. This regulatory activity could be mediated either through a feed-back mechanism acting on ICC production or through a more complex process involving an interaction between antigens and cells. (author)

  8. Thoughts on the chimera method of simulation of three-dimensional viscous flow

    Science.gov (United States)

    Steger, Joseph L.

    1991-01-01

    The chimera overset grid is reviewed and discussed relative to other procedures for simulating flow about complex configurations. It is argued that while more refinement of the technique is needed, current schemes are competitive to unstructured grid schemes and should ultimately prove more useful.

  9. The Chimera Method of Simulation for Unsteady Three-Dimensional Viscous Flow

    Science.gov (United States)

    Meakin, Robert L.

    1996-01-01

    The Chimera overset grid method is reviewed and discussed in the context of a method of solution and analysis of unsteady three-dimensional viscous flows. The state of maturity of the various pieces of support software required to use the approach is discussed. A variety of recent applications of the method is presented. Current limitations of the approach are defined.

  10. Studies on the mechanism of the self restriction of T cell responses in radiation chimeras

    International Nuclear Information System (INIS)

    Recent experiments with murine radiation chimeras have shown that F1 T cells that mature in an H-2 homozygous thymus, as is the case in [F1 → Parent 1] chimeras, are restricted to recognizing foreign antigen in the context of Parent 1 H-2 antigens. Conflicting results on the stringency of self H-2 restriction of T cells from normal mice have suggested that the thymic restriction in chimeras may be due to active suppression of parent 2-restricted T cell clones. We have therefore conducted 3 sets of experiments to test for suppression of maturing T cells that could mediate thymic tutoring of H-2-restriction specificity in chimeras. In 2 sets of experiments, we found no evidence that suppressor cells could be exported from 1 thymus and act either intrathymically on thymocytes in a 2nd thymus or extrathymically on recent thymic emigrants. We believe current data support a role for the thymus in positive as well as negative selection of maturing thymocytes on the basis of self recognition, in the absence of any suppression. Our results do not support the concept that suppression is responsible for the difference in the degree of self preference in the T cells of chimeric mice relative to cell populations obtained from neonatally tolerant mice or from normal mice after acute negative selection

  11. Analysis of the hormone-binding domain of steroid receptors using chimeras generated by homologous recombination

    International Nuclear Information System (INIS)

    The glucocorticoid receptor and the mineralocorticoid receptor are members of the steroid receptor family that exhibit ligand cross-reactivity. Specificity of steroid receptor action is investigated in the present work by the construction and characterization of chimeras between the glucocorticoid receptor and the mineralocorticoid receptor. We used an innovative approach to make novel steroid receptor proteins in vivo that in general, contrary to our expectations, show increased ligand specificity compared to the parental receptors. We describe a receptor that is specific for the potent synthetic glucocorticoid triamcinolone acetonide and does not bind aldosterone. A further set of chimeras has an increased ability to discriminate between ligands, responding potently to mineralocorticoids and only very weakly to synthetic glucocorticoids. A chimera with the fusion site in the hinge highlights the importance of the region between the DNA-binding and the hormone-binding domains since, unlike both the glucocorticoid and mineralocorticoid receptors, it only responds to mineralocorticoids. One chimera has reduced specificity in that it acts as a general corticoid receptor, responding to glucocorticoids and mineralocorticoids with similar potency and efficacy. Our data suggest that regions of the glucocorticoid and mineralocorticoid receptor hormone-binding domains are functionally non-reciprocal. We present transcriptional, hormone-binding, and structure-modeling evidence that suggests that receptor-specific interactions within and across domains mediate aspects of specificity in transcriptional responses to steroids

  12. Construction of RNA-Quantum Dot Chimera for Nanoscale Resistive Biomemory Application.

    Science.gov (United States)

    Lee, Taek; Yagati, Ajay Kumar; Pi, Fengmei; Sharma, Ashwani; Choi, Jeong-Woo; Guo, Peixuan

    2015-07-28

    RNA nanotechnology offers advantages to construct thermally and chemically stable nanoparticles with well-defined shape and structure. Here we report the development of an RNA-QD (quantum dot) chimera for resistive biomolecular memory application. Each QD holds two copies of the pRNA three-way junction (pRNA-3WJ) of the bacteriophage phi29 DNA packaging motor. The fixed quantity of two RNAs per QD was achieved by immobilizing the pRNA-3WJ with a Sephadex aptamer for resin binding. Two thiolated pRNA-3WJ serve as two feet of the chimera that stand on the gold plate. The RNA nanostructure served as both an insulator and a mediator to provide defined distance between the QD and gold. Immobilization of the chimera nanoparticle was confirmed with scanning tunneling microscopy. As revealed by scanning tunneling spectroscopy, the conjugated pRNA-3WJ-QD chimera exhibited an excellent electrical bistability signal for biomolecular memory function, demonstrating great potential for the development of resistive biomolecular memory and a nano-bio-inspired electronic device for information processing and computing. PMID:26135474

  13. Incoherent chimera and glassy states in coupled oscillators with frustrated interactions

    Science.gov (United States)

    Choe, Chol-Ung; Ri, Ji-Song; Kim, Ryong-Son

    2016-09-01

    We suggest a site disorder model that describes the population of identical oscillators with quenched random interactions for both the coupling strength and coupling phase. We obtain the reduced equations for the suborder parameters, on the basis of Ott-Antonsen ansatz theory, and present a complete bifurcation analysis of the reduced system. New effects include the appearance of the incoherent chimera and glassy state, both of which are caused by heterogeneity of the coupling phases. In the incoherent chimera state, the system displays an exotic symmetry-breaking behavior in spite of the apparent structural symmetry where the oscillators for both of the two subpopulations are in a frustrated state, while the phase distribution for each subpopulation approaches a steady state that differs from each other. When the incoherent chimera undergoes Hopf bifurcation, the system displays a breathing incoherent chimera. The glassy state that occurs on a surface of three-dimensional parameter space exhibits a continuum of metastable states with zero value of the global order parameter. Explicit formulas are derived for the system's Hopf, saddle-node, and transcritical bifurcation curves, as well as the codimension-2 crossing points, including the Takens-Bogdanov point.

  14. MS Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Koppenaal, David W.; Barinaga, Charles J.; Denton, M Bonner B.; Sperline, Roger P.; Hieftje, Gary M.; Schilling, G. D.; Andrade, Francisco J.; Barnes IV., James H.

    2005-11-01

    Good eyesight is often taken for granted, a situation that everyone appreciates once vision begins to fade with age. New eyeglasses or contact lenses are traditional ways to improve vision, but recent new technology, i.e. LASIK laser eye surgery, provides a new and exciting means for marked vision restoration and improvement. In mass spectrometry, detectors are the 'eyes' of the MS instrument. These 'eyes' have also been taken for granted. New detectors and new technologies are likewise needed to correct, improve, and extend ion detection and hence, our 'chemical vision'. The purpose of this report is to review and assess current MS detector technology and to provide a glimpse towards future detector technologies. It is hoped that the report will also serve to motivate interest, prompt ideas, and inspire new visions for ion detection research.

  15. Development and construction of a detector array for ({gamma},n) experiments at NEPTUN

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Vanessa; Loeher, Bastian; Pietralla, Norbert; Schnorrenberger, Linda; Savran, Deniz; Sonnabend, Kerstin [Institut fuer Kernphysik, Technische Universitaet, Darmstadt (Germany)

    2009-07-01

    The low-energy photon tagger NEPTUN has been built at the superconducting electron accelerator S-DALINAC at TU Darmstadt. This spectrometer generates a tagged photon beam in an energy range between 6 MeV< E{sub {gamma}}<20 MeV. For ({gamma},n) experiments a neutron detector array will be designed in a 4{pi}-geometry consisting of 17 detectors. Each detector contains liquid scintillators so that pulse shape discrimination methods can be applied. Four of the detectors are in addition loaded with 5% {sup 10}B to further discriminate between neutrons and photons via the capture reaction {sup 10}B(n,{alpha}){sup 7}Li. The special conditions, as well as initial developments and construction work is shown. Furthermore, first experiments and efficiency measurements are presented.

  16. Standardisation of sup 9 sup 0 Sr, sup 6 sup 3 Ni and sup 5 sup 5 Fe by the 4 pi beta liquid scintillation spectrometry method with sup 3 H-standard efficiency tracing

    CERN Document Server

    Ceccatelli, A

    1999-01-01

    The 4 pi beta efficiency tracing liquid scintillation spectrometry method was applied with success, at ENEA, to the activity measurement of pure beta-emitters ( sup 9 sup 0 Sr and sup 6 sup 3 Ni) and electron-capturing nuclides ( sup 5 sup 5 Fe), using sup 3 H as tracer nuclide. The agreement of these measurements in comparison to other national metrology institutes was checked by means of two comparisons, carried out in 1996-1997. Furthermore a study of the stability of the prepared sources was performed and the dependence of the measured activity concentration on the quenching level was analysed. The radionuclides were standardised to a combined standard uncertainty of 0.14% for sup 9 sup 0 Sr, 0.55% for sup 6 sup 3 Ni and 1.18% for sup 5 sup 5 Fe.

  17. Embryonic stem cells contribute to mouse chimeras in the absence of detectable cell fusion.

    Science.gov (United States)

    Kidder, Benjamin L; Oseth, Leann; Miller, Shanna; Hirsch, Betsy; Verfaillie, Catherine; Coucouvanis, Electra

    2008-06-01

    Embryonic stem (ES) cells are capable of differentiating into all embryonic and adult cell types following mouse chimera production. Although injection of diploid ES cells into tetraploid blastocysts suggests that tetraploid cells have a selective disadvantage in the developing embryo, tetraploid hybrid cells, formed by cell fusion between ES cells and somatic cells, have been reported to contribute to mouse chimeras. In addition, other examples of apparent stem cell plasticity have recently been shown to be the result of cell fusion. Here we investigate whether ES cells contribute to mouse chimeras through a cell fusion mechanism. Fluorescence in situ hybridization (FISH) analysis for X and Y chromosomes was performed on dissociated tissues from embryonic, neonatal, and adult wild-type, and chimeric mice to follow the ploidy distributions of cells from various tissues. FISH analysis showed that the ploidy distributions in dissociated tissues, notably the tetraploid cell number, did not differ between chimeric and wild-type tissues. To address the possibility that early cell fusion events are hidden by subsequent reductive divisions or other changes in cell ploidy, we injected Z/EG (lacZ/EGFP) ES cells into ACTB-cre blastocysts. Recombination can only occur as the result of cell fusion, and the recombined allele should persist through any subsequent changes in cell ploidy. We did not detect evidence of fusion in embryonic chimeras either by direct fluorescence microscopy for GFP or by PCR amplification of the recombined Z/EG locus on genomic DNA from ACTB-cre::Z/EG chimeric embryos. Our results argue strongly against cell fusion as a mechanism by which ES cells contribute to chimeras.

  18. New digital techniques applied to A and Z identification using pulse shape discrimination of silicon detector current signals

    Energy Technology Data Exchange (ETDEWEB)

    Barlini, S. [LPC Caen, ENSICAEN, University of Caen, CNRS/IN2P3, Caen (France)], E-mail: barlini@fi.infn.it; Bougault, R.; Laborie, Ph.; Lopez, O.; Mercier, D. [LPC Caen, ENSICAEN, University of Caen, CNRS/IN2P3, Caen (France); Parlog, M. [LPC Caen, ENSICAEN, University of Caen, CNRS/IN2P3, Caen (France); NIPNE, RO-76900 Bucharest (Romania); Tamain, B.; Vient, E. [LPC Caen, ENSICAEN, University of Caen, CNRS/IN2P3, Caen (France); Chevallier, E.; Chbihi, A.; Jacquot, B. [GANIL, CEA/DSM-CNRS/IN2P3, Caen (France); Kravchuk, V.L. [INFN-LNL, I-35020 Legnaro, Padova (Italy)

    2009-03-11

    Extending pulse shape discrimination (PSD) to digitized signals is one of the most promising methods to identify particles stopped in a detector. Using the CIME accelerator in the GANIL laboratory, a measurement campaign was done to collect data corresponding to different charges, masses and energies of implanted ions. These data are used to develop an algorithm capable to discriminate the different particles both in mass and charge. In this experiment, a 300{mu}m n-TD reverse mounted Si detector was used. These studies on PSD are part of the FAZIA R and D, a research and development project aiming at building a new 4{pi} array for isospin nuclear physics.

  19. Photon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Va`vra, J.

    1995-10-01

    J. Seguinot and T. Ypsilantis have recently described the theory and history of Ring Imaging Cherenkov (RICH) detectors. In this paper, I will expand on these excellent review papers, by covering the various photon detector designs in greater detail, and by including discussion of mistakes made, and detector problems encountered, along the way. Photon detectors are among the most difficult devices used in physics experiments, because they must achieve high efficiency for photon transport and for the detection of single photo-electrons. For gaseous devices, this requires the correct choice of gas gain in order to prevent breakdown and wire aging, together with the use of low noise electronics having the maximum possible amplification. In addition, the detector must be constructed of materials which resist corrosion due to photosensitive materials such as, the detector enclosure must be tightly sealed in order to prevent oxygen leaks, etc. The most critical step is the selection of the photocathode material. Typically, a choice must be made between a solid (CsI) or gaseous photocathode (TMAE, TEA). A conservative approach favors a gaseous photocathode, since it is continuously being replaced by flushing, and permits the photon detectors to be easily serviced (the air sensitive photocathode can be removed at any time). In addition, it can be argued that we now know how to handle TMAE, which, as is generally accepted, is the best photocathode material available as far as quantum efficiency is concerned. However, it is a very fragile molecule, and therefore its use may result in relatively fast wire aging. A possible alternative is TEA, which, in the early days, was rejected because it requires expensive CaF{sub 2} windows, which could be contaminated easily in the region of 8.3 eV and thus lose their UV transmission.

  20. Photon detectors

    International Nuclear Information System (INIS)

    J. Seguinot and T. Ypsilantis have recently described the theory and history of Ring Imaging Cherenkov (RICH) detectors. In this paper, I will expand on these excellent review papers, by covering the various photon detector designs in greater detail, and by including discussion of mistakes made, and detector problems encountered, along the way. Photon detectors are among the most difficult devices used in physics experiments, because they must achieve high efficiency for photon transport and for the detection of single photo-electrons. For gaseous devices, this requires the correct choice of gas gain in order to prevent breakdown and wire aging, together with the use of low noise electronics having the maximum possible amplification. In addition, the detector must be constructed of materials which resist corrosion due to photosensitive materials such as, the detector enclosure must be tightly sealed in order to prevent oxygen leaks, etc. The most critical step is the selection of the photocathode material. Typically, a choice must be made between a solid (CsI) or gaseous photocathode (TMAE, TEA). A conservative approach favors a gaseous photocathode, since it is continuously being replaced by flushing, and permits the photon detectors to be easily serviced (the air sensitive photocathode can be removed at any time). In addition, it can be argued that we now know how to handle TMAE, which, as is generally accepted, is the best photocathode material available as far as quantum efficiency is concerned. However, it is a very fragile molecule, and therefore its use may result in relatively fast wire aging. A possible alternative is TEA, which, in the early days, was rejected because it requires expensive CaF2 windows, which could be contaminated easily in the region of 8.3 eV and thus lose their UV transmission

  1. Pixel detectors

    CERN Document Server

    Passmore, M S

    2001-01-01

    positions on the detector. The loss of secondary electrons follows the profile of the detector and increases with higher energy ions. studies of the spatial resolution predict a value of 5.3 lp/mm. The image noise in photon counting systems is investigated theoretically and experimentally and is shown to be given by Poisson statistics. The rate capability of the LAD1 was measured to be 250 kHz per pixel. Theoretical and experimental studies of the difference in contrast for ideal charge integrating and photon counting imaging systems were carried out. It is shown that the contrast differs and that for the conventional definition (contrast = (background - signal)/background) the photon counting device will, in some cases, always give a better contrast than the integrating system. Simulations in MEDICI are combined with analytical calculations to investigate charge collection efficiencies (CCE) in semiconductor detectors. Different pixel sizes and biasing conditions are considered. The results show charge shari...

  2. Calorimeter detectors

    CERN Document Server

    de Barbaro, P; The ATLAS collaboration

    2013-01-01

    Although the instantaneous and integrated luminosity in HL-LHC will be far higher than the LHC detectors were originally designed for, the Barrel calorimeters of the four experiments are expected to continue to perform well  throughout the Phase II program. The conditions for the End-Cap calorimeters are far more challenging and whilst some detectors will require relatively modest changes, others require far more substantial upgrades. We present the results of longevity and performance studies for the calorimeter systems of the four main LHC experiments and outline the upgrade options under consideration. We include a discussion of the R&D required to make the final technology choices for the upgraded detectors.

  3. MAMA Detector

    Science.gov (United States)

    Bowyer, Stuart

    1998-01-01

    Work carried out under this grant led to fundamental discoveries and over one hundred publications in the scientific literature. Fundamental developments in instrumentation were made including all the instrumentation on the EUVE satellite, the invention of a whole new type of grazing instrument spectrometer and the development of fundamentally new photon counting detectors including the Wedge and Strip used on EUVE and many other missions and the Time Delay detector used on OREFUS and FUSE. The Wedge and Strip and Time Delay detectors were developed under this grant for less than two million dollars and have been used in numerous missions most recently for the FUSE mission. In addition, a fundamentally new type of diffuse spectrometer has been developed under this grant which has been used in instrumentation on the MMSAT spacecraft and the Lewis spacecraft. Plans are underway to use this instrumentation on several other missions as well.

  4. Bioinspired silicification of silica-binding peptide-silk protein chimeras: comparison of chemically and genetically produced proteins.

    Science.gov (United States)

    Canabady-Rochelle, Laetitia L S; Belton, David J; Deschaume, Olivier; Currie, Heather A; Kaplan, David L; Perry, Carole C

    2012-03-12

    Novel protein chimeras constituted of "silk" and a silica-binding peptide (KSLSRHDHIHHH) were synthesized by genetic or chemical approaches and their influence on silica-silk based chimera composite formation evaluated. Genetic chimeras were constructed from 6 or 15 repeats of the 32 amino acid consensus sequence of Nephila clavipes spider silk ([SGRGGLGGQG AGAAAAAGGA GQGGYGGLGSQG](n)) to which one silica binding peptide was fused at the N terminus. For the chemical chimera, 28 equiv of the silica binding peptide were chemically coupled to natural Bombyx mori silk after modification of tyrosine groups by diazonium coupling and EDC/NHS activation of all acid groups. After silica formation under mild, biomaterial-compatible conditions, the effect of peptide addition on the properties of the silk and chimeric silk-silica composite materials was explored. The composite biomaterial properties could be related to the extent of silica condensation and to the higher number of silica binding sites in the chemical chimera as compared with the genetically derived variants. In all cases, the structure of the protein/chimera in solution dictated the type of composite structure that formed with the silica deposition process having little effect on the secondary structural composition of the silk-based materials. Similarly to our study of genetic silk based chimeras containing the R5 peptide (SSKKSGSYSGSKGSKRRIL), the role of the chimeras (genetic and chemical) used in the present study resided more in aggregation and scaffolding than in the catalysis of condensation. The variables of peptide identity, silk construct (number of consensus repeats or silk source), and approach to synthesis (genetic or chemical) can be used to "tune" the properties of the composite materials formed and is a general approach that can be used to prepare a range of materials for biomedical and sensor-based applications. PMID:22229696

  5. Assay using embryo aggregation chimeras for the detection of nonlethal changes in X-irradiated mouse preimplantation embryos

    International Nuclear Information System (INIS)

    We have developed a short-term in vitro assay for the detection of sublethal effects produced by very low levels of ionizing radiation. The assay utilizes mouse embryo aggregation chimeras consisting of one irradiated embryo paired with an unirradiated embryo whose blastomeres have been labeled with fluorescein isothiocyanate (FITC). X irradiation (from 0.05 to 2 Gy) and chimera construction were performed with four-cell stage embryos, and the chimeras were cultured for 40 h to the morula stage. The morulae were partially dissociated with calcium-free culture medium and viewed under phase contrast and epifluorescence microscopy to obtain total embryo cell number and the cellular contribution of irradiated (unlabeled) and control (FITC labeled) embryos per chimera. In chimeras where neither embryo was irradiated, the ratio of the unlabeled blastomeres to the total number of blastomeres per chimera embryo was 0.50 (17.8 +/- 5.6 cells per unlabeled embryo and 17.4 +/- 5.5 cells per FITC-labeled partner embryo). However, in chimeras formed after the unlabeled embryos were irradiated with as little as 0.05 Gy, the ratio of unlabeled blastomeres to the total number of blastomeres per chimera embryo was 0.43 (P less than 0.01). The apparent decreases in cell proliferation were not observed in irradiated embryos that were merely cocultured with control embryos, regardless of whether the embryos were zona enclosed or zona free. We conclude that very low levels of radiation induce sublethal changes in cleaving embryos that are expressed as a proliferative disadvantage within two cell cycles when irradiated embryos are in direct cell-to-cell contact with unirradiated embryos

  6. Differential identification of ID sequence of DNA in cells of rats, mouse, and rat-mouse radiation chimeras

    International Nuclear Information System (INIS)

    It is shown that ID-sequence can be used for identification of donor cells of rat-mouse radiation chimeras. The fact of intensive binding of labelled probe with cytoplasmic cell components of neutrophilic series of differentiation is noted. Trace were observed at that both for rats and radiation chimeras, and some times-for mice. The reasons of observed phenomenon are interesting from the viewpoint of working out techniques and characterizing functional peculiarities of cells of different lines and differentiation stages

  7. BES detector

    International Nuclear Information System (INIS)

    The Beijing Spectrometer (BES) is a general purpose solenoidal detector at the Beijing Electron Positron Collider (BEPC). It is designed to study exclusive final states in e+e- annihilations at the center of mass energy from 3.0 to 5.6 GeV. This requires large solid angle coverage combined with good charged particle momentum resolution, good particle identification and high photon detection efficiency at low energies. In this paper we describe the construction and the performance of BES detector. (orig.)

  8. The ALEPH Detector (Apparatus for LEp PHysics)

    CERN Multimedia

    2002-01-01

    ALEPH is a 4$\\pi$ detector designed to give as much detailed information as possible about the complex events produced in high energy $\\mathrm{e}^+\\mathrm{e}^-$ collisions. A superconducting coil 5 metres in diameter and 6 metres long produces a 1.5 Tesla field in the beam direction. Particle detection is accomplished in layers, with each layer performing a particular function.\\\\ \\\\A high resolution vertex detector layers of silicon with double-sided readout provides $r$, $\\phi$ and $z$ coordinates and identifies decay vertices of tau leptons, charm and beauty hadrons. \\\\ \\\\The Inner Tracking Chamber (ITC) is a cylindrical drift chamber with eight axial layers. It gives a high spatial resolution and good track separation, and is also an essential part of the trigger system.\\\\ \\\\The Time Projection Chamber (TPC), 3.6 metres in diameter and 4.4 metres long, measures track momenta and directions. It also provides up to 338 energy loss measurements per track for particle identification. The momentum resolution of...

  9. H-2 restriction of the T cell response to chemically induced tumors: evidence from F1 → parent chimeras

    International Nuclear Information System (INIS)

    It has been well established that T cells that react to tumor antigen on virus-induced tumors must share H-2D or H-2K specificities with the tumor. It has been impossible to perform similar studies with chemically induced tumors because each chemically induced tumor expresses a unique tumor antigen that cannot be studied in association with other H-2 types. This study provies evidence that H-2 recognition is also necessary for recognition of chemically induced tumors. We have found that F1 → parent chimeras preferentially recognize chemically induced tumors of parental H-2 type. C3H/HeJ and C57BL/6 mice were lethally irradiated and restored with (C3H x C57BL/6) F1 hybrid bone marrow. The F1 → C3H chimera but not the F1 → C57BL/6 chimera was able to respond to a C3H fibrosarcoma in mixed lymphocyte-tumor cell culture and also to neutralize the tumor in an in vivo tumor neutralization assay. On the other hand, the F1 → C57BL/6 chimera but not the F1 → C3H chimera was able to kill the C57BL/6 lymphoma EL4 in an in vitro cytotoxicity assay. Both chimeras were tolerant to C3H and C57BL/6 alloantigens but could respond normally to Con A and to BALB/c spleen cells in mixed lymphocyte cultures and cytotoxicity assay

  10. Chronic graft-versus-host disease in the rat radiation chimera: I. clinical features, hematology, histology, and immunopathology in long-term chimeras

    Energy Technology Data Exchange (ETDEWEB)

    Beschorner, W.E.; Tutschka, P.J.; Santos, G.W.

    1982-04-01

    The clinical features, pathology, and immunopathology of chronic graft-versus-host disease (GVHD) developing in the long-term rat radiation chimera are described. At 6 to 12 months post-transplant, the previously stable ACI/LEW chimeras developed patchy to diffuse severe hair loss and thickened skin folds, and had microscopic features resembling scleroderma, Sjogren's syndrome, and chronic hepatitis. Skin histology showed dermal inflammation and acanthosis with atrophy of the appendages, with progression to dermal sclerosis. The liver revealed chronic hepatitis with bile duct injury and proliferation and periportal piecemeal necrosis. The tongue had considerable submucosal inflammation, muscular necrosis, and atrophy and arteritis. The serous salivary glands, lacrimal glands, and bronchi had lymphocytic inflammation and injury to duct, acinar, and mucosal columnar epithelium. The thymus had lymphocyte depletion of the medulla with prominent epithelium. The spleen and lymph nodes had poorly developed germinal centers but increased numbers of plasma cells. IgM was observed along the basement membrane and around the basal cells of the skin and tongue and along the basement membrane of the bile ducts. IgM was present also in the arteries of the tongue. Immunoglobulins eluted from the skin, cross-reacted with the bile duct epithelium and usually with both ACI and Lewis skin. Increased titers of speckled antinuclear antibodies were present in the serum of rats with chronic (GVHD). Chronic GVHD in the long-term rat radiation chimera is very similar to human chronic GVHD and is a potentially excellent model for autoimmune disorders including scleroderma, Sjorgren's syndrome, and chronic hepatitis.

  11. Chronic graft-versus-host disease in the rat radiation chimera: I. clinical features, hematology, histology, and immunopathology in long-term chimeras

    International Nuclear Information System (INIS)

    The clinical features, pathology, and immunopathology of chronic graft-versus-host disease (GVHD) developing in the long-term rat radiation chimera are described. At 6 to 12 months post-transplant, the previously stable ACI/LEW chimeras developed patchy to diffuse severe hair loss and thickened skin folds, and had microscopic features resembling scleroderma, Sjogren's syndrome, and chronic hepatitis. Skin histology showed dermal inflammation and acanthosis with atrophy of the appendages, with progression to dermal sclerosis. The liver revealed chronic hepatitis with bile duct injury and proliferation and periportal piecemeal necrosis. The tongue had considerable submucosal inflammation, muscular necrosis, and atrophy and arteritis. The serous salivary glands, lacrimal glands, and bronchi had lymphocytic inflammation and injury to duct, acinar, and mucosal columnar epithelium. The thymus had lymphocyte depletion of the medulla with prominent epithelium. The spleen and lymph nodes had poorly developed germinal centers but increased numbers of plasma cells. IgM was observed along the basement membrane and around the basal cells of the skin and tongue and along the basement membrane of the bile ducts. IgM was present also in the arteries of the tongue. Immunoglobulins eluted from the skin, cross-reacted with the bile duct epithelium and usually with both ACI and Lewis skin. Increased titers of speckled antinuclear antibodies were present in the serum of rats with chronic (GVHD). Chronic GVHD in the long-term rat radiation chimera is very similar to human chronic GVHD and is a potentially excellent model for autoimmune disorders including scleroderma, Sjorgren's syndrome, and chronic hepatitis

  12. Navier-Stokes calculations on multi-element airfoils using a chimera-based solver

    Science.gov (United States)

    Jasper, Donald W.; Agrawal, Shreekant; Robinson, Brian A.

    1993-01-01

    A study of Navier-Stokes calculations of flows about multielement airfoils using a chimera grid approach is presented. The chimera approach utilizes structured, overlapped grids which allow great flexibility of grid arrangement and simplifies grid generation. Calculations are made for two-, three-, and four-element airfoils, and modeling of the effect of gap distance between elements is demonstrated for a two element case. Solutions are obtained using the thin-layer form of the Reynolds averaged Navier-Stokes equations with turbulence closure provided by the Baldwin-Lomax algebraic model or the Baldwin-Barth one equation model. The Baldwin-Barth turbulence model is shown to provide better agreement with experimental data and to dramatically improve convergence rates for some cases. Recently developed, improved farfield boundary conditions are incorporated into the solver for greater efficiency. Computed results show good comparison with experimental data which include aerodynamic forces, surface pressures, and boundary layer velocity profiles.

  13. The Chimera Scheme: Approximate Waveforms for Extreme-Mass-Ratio Inspirals

    CERN Document Server

    Sopuerta, Carlos F

    2011-01-01

    We introduce the Chimera scheme, a new framework to model the dynamics of generic extreme mass-ratio inspirals (stellar compact objects spiraling into a spinning super-massive black hole) and to produce the gravitational waveforms that describe the gravitational wave emission of these systems. The Chimera scheme combines techniques from black hole perturbation theory and post-Minkowskian theory. The orbital evolution is approximated as a sequence of osculating geodesics that shrink due to the stellar compact object's self-acceleration. Lacking a general prescription for this self-force, we here approximate it locally in time via a post-Minkowskian expansion. The orbital evolution is thus equivalent to evolving the geodesic equations with time-dependent orbital elements, as dictated by this post-Minkowskian radiation-reaction prescription. Gravitational radiation is modeled via a multipolar expansion in post-Minkowskian theory, here taken up to mass hexadecapole and current octopole order. To complete the sche...

  14. Enhanced antibody affinity in sublethally irradiated mice and bone marrow chimeras

    International Nuclear Information System (INIS)

    Sublethally irradiated mice primed with dinitrophenyl (Dnp)-keyhole limpet hemocyanin immediately after irradiation or 30 days later and subsequently boosted with a second injection of antigen displayed a secondary response to Dnp characterized by antibody affinity greater than that in unirradiated controls. Also, in radiation chimeras primed with Dnp-keyhole limpet hemocyanin 120 days after syngeneic or allogeneic bone marrow transplantation the antibodies against Dnp produced after boosting were of higher affinity than the antibodies raised in normal mice. These findings are tentatively attributed to lack of suppressor thymus-derived lymphocytes (T cells) in sublethally irradiated mice and bone marrow chimeras, in which the enhanced ability to produce antibodies of high affinity may compensate for quantitative defects of the immune system

  15. On the application of Chimera/unstructured hybrid grids for conjugate heat transfer

    Science.gov (United States)

    Kao, Kai-Hsiung; Liou, Meng-Sing

    1995-01-01

    A hybrid grid system that combines the Chimera overset grid scheme and an unstructured grid method is developed to study fluid flow and heat transfer problems. With the proposed method, the solid structural region, in which only the heat conduction is considered, can be easily represented using an unstructured grid method. As for the fluid flow region external to the solid material, the Chimera overset grid scheme has been shown to be very flexible and efficient in resolving complex configurations. The numerical analyses require the flow field solution and material thermal response to be obtained simultaneously. A continuous transfer of temperature and heat flux is specified at the interface, which connects the solid structure and the fluid flow as an integral system. Numerical results are compared with analytical and experimental data for a flat plate and a C3X cooled turbine cascade. A simplified drum-disk system is also simulated to show the effectiveness of this hybrid grid system.

  16. Chimera states in population dynamics: Networks with fragmented and hierarchical connectivities

    Science.gov (United States)

    Hizanidis, Johanne; Panagakou, Evangelia; Omelchenko, Iryna; Schöll, Eckehard; Hövel, Philipp; Provata, Astero

    2015-07-01

    We study numerically the development of chimera states in networks of nonlocally coupled oscillators whose limit cycles emerge from a Hopf bifurcation. This dynamical system is inspired from population dynamics and consists of three interacting species in cyclic reactions. The complexity of the dynamics arises from the presence of a limit cycle and four fixed points. When the bifurcation parameter increases away from the Hopf bifurcation the trajectory approaches the heteroclinic invariant manifolds of the fixed points producing spikes, followed by long resting periods. We observe chimera states in this spiking regime as a coexistence of coherence (synchronization) and incoherence (desynchronization) in a one-dimensional ring with nonlocal coupling and demonstrate that their multiplicity depends on both the system and the coupling parameters. We also show that hierarchical (fractal) coupling topologies induce traveling multichimera states. The speed of motion of the coherent and incoherent parts along the ring is computed through the Fourier spectra of the corresponding dynamics.

  17. Suppressor cells in transplantation tolerance: the mechanisms of tolerance in radiation chimeras

    International Nuclear Information System (INIS)

    Histoincompatible-complete radiation chimeras, after resolving acute graft-vs-host (GVHD), establish specific tolerance to host and donor alloantigens. This tolerance can be perturbed with immunosuppressive agents and infusions of small numbers of donor-type cells with infusions of massive numbers of donor-type cells, or with infusions of a small number of donor-type cells, that were sensitized against host antigens prior to transfer. These chimeras possess T lymphocytes in the spleen that specifically suppress donor to host mixed lymphocyte reactions and adoptively transfer suppression of GVHD to secondary hosts. Nylon-wool fractionation of chimeric spleen cells restores the response of chimeric lymphocytes to host alloantigens, suggesting that transplantation tolerance is not attributable to clonal deletion but the activity of nylon-wool-adherent T suppressor spleen cells

  18. Suppressor cells in transplantation tolerance II. Maturation of suppressor cells in the bone marrow chimera

    International Nuclear Information System (INIS)

    Histoincompatible bone marrow allografts were established in lethally irradiated rats. At various times after transplantation, the spleen cells were harvested, subjected to mixed lymphocyte cultures, and assayed for suppressor cells in vitro and in vivo by adoptive transfer studies. Alloantigen-nonspecific suppressor cells appeared in the chimera at 40 days after grafting, coinciding with the resolution of graft-versus-host disease (GVHD). At 250 days the nonspecific suppressor cells were replaced by suppressor cells specifically suppressing donor-versus-host alloantigen responses. At 720 days suppressor cells could no longer be identified by in vitro methods but were identified by in vivo adoptive transfer of transplantation tolerance. After injection of host-type antigen into chimeras, the suppressor cells could be again demonstrated by in vitro methods

  19. Suppressor cells in transplantation tolerance. II. maturation of suppressor cells in the bone marrow chimera

    International Nuclear Information System (INIS)

    Histoincompatible bone marrow allografts were established in lethally irradiated rats. At various times after transplantation, the spleen cells were harvested, subjected to mixed lymphocyte cultures, and assayed for suppressor cells in vitro and in vivo by adoptive transfer studies. Alloantigen-nonspecific suppressor cells appeared in the chimera at 40 days after grafting, coinciding with the resolution of graft-versus-host disease (GVHD). At 250 days the nonspecific suppressor cells were replaced by suppressor cells specifically suppressing donor-versus-host alloantigen responses. At 720 days suppressor cells could no longer be identified by in vitro methods but were identified by in vivo adoptive transfer of transplantation tolerance. After injection of host-type antigen into chimeras, the suppressor cells could be again demonstrated by in vitro methods

  20. Numerical solution of the full potential equation using a chimera grid approach

    Science.gov (United States)

    Holst, Terry L.

    1995-01-01

    A numerical scheme utilizing a chimera zonal grid approach for solving the full potential equation in two spatial dimensions is described. Within each grid zone a fully-implicit approximate factorization scheme is used to advance the solution one interaction. This is followed by the explicit advance of all common zonal grid boundaries using a bilinear interpolation of the velocity potential. The presentation is highlighted with numerical results simulating the flow about a two-dimensional, nonlifting, circular cylinder. For this problem, the flow domain is divided into two parts: an inner portion covered by a polar grid and an outer portion covered by a Cartesian grid. Both incompressible and compressible (transonic) flow solutions are included. Comparisons made with an analytic solution as well as single grid results indicate that the chimera zonal grid approach is a viable technique for solving the full potential equation.

  1. Chimera patterns induced by distance-dependent power-law coupling in ecological networks

    Science.gov (United States)

    Banerjee, Tanmoy; Dutta, Partha Sharathi; Zakharova, Anna; Schöll, Eckehard

    2016-09-01

    This paper reports the occurrence of several chimera patterns and the associated transitions among them in a network of coupled oscillators, which are connected by a long-range interaction that obeys a distance-dependent power law. This type of interaction is common in physics and biology and constitutes a general form of coupling scheme, where by tuning the power-law exponent of the long-range interaction the coupling topology can be varied from local via nonlocal to global coupling. To explore the effect of the power-law coupling on collective dynamics, we consider a network consisting of a realistic ecological model of oscillating populations, namely the Rosenzweig-MacArthur model, and show that the variation of the power-law exponent mediates transitions between spatial synchrony and various chimera patterns. We map the possible spatiotemporal states and their scenarios that arise due to the interplay between the coupling strength and the power-law exponent.

  2. Capturing the Chimera: Ideology and Persuasion in the Rhetoric of Soulforce

    OpenAIRE

    Null, Matthew Todd

    2008-01-01

    Capturing the Chimera: Ideology and Persuasion in the Rhetoric of Soulforce Matthew Todd Null (ABSTRACT) For more than half a century, gay rights organizations have sought cultural and political equality for lesbian, gay, bisexual, and transgender individuals in society. The organization Soulforce continues that legacy, but from a distinctive perspective. Soulforce, has positioned itself in a unique playing field by speaking directly to religious leaders and organizations in ...

  3. Application of a chimera technique to the computation of subsonic and transonic bi-airfoil flows

    OpenAIRE

    Yagua, L.C.Q.; Koren, Barry

    2004-01-01

    This paper describes the application of a composite overset-grid technique to flow computations around a two-dimensional bi-plane. The flow is described by the steady, 2D, compressible Euler equations of gas dynamics. The discretization method used is a central finite-difference method with artificial dissipation. The overset-grid technique is of chimera-type and the bi-plane a bi-NACA0012 airfoil.

  4. MODELS FOR MOUSE CHIMERA PRODUCTION: AGGREGATION OF ES CELLS WITH CLEAVAGE STAGE EMBRYOS

    OpenAIRE

    CLAUDIA STANCA; V.B. CÂRSTEA; DANIELA ILIE; ELEN GOCZA; I. VINTILĂ

    2007-01-01

    In a mutant ES cells↔ wild-type embryo chimera, ES cells behave more like epiblastcells. They can contribute to the primitive ectoderm layers, which give rise to all theembryonic tissues and some extraembryonic tissues (Beddington and Robertson,1989), but not to trophectoderm or primitive endoderm. Using transgenic ES celllines, aggregated with cleavage stage host embryo, ES cells can integrate randomlyin the embryo proper. If they will be take part in the formation of ICM (inner cellmass), i...

  5. SummonChimera infers integrated viral genomes with nucleotide precision from NGS data

    OpenAIRE

    Katz, Joshua P.; Pipas, James M.

    2014-01-01

    Background Viral integration into a host genome is defined by two chimeric junctions that join viral and host DNA. Recently, computational tools have been developed that utilize NGS data to detect chimeric junctions. These methods identify individual viral-host junctions but do not associate chimeric pairs as an integration event. Without knowing the chimeric boundaries of an integration, its genetic content cannot be determined. Results Summonchimera is a Perl program that associates chimera...

  6. Does hyperbolicity impede emergence of chimera states in networks of nonlocally coupled chaotic oscillators?

    Science.gov (United States)

    Semenova, N.; Zakharova, A.; Schöll, E.; Anishchenko, V.

    2015-11-01

    We analyze nonlocally coupled networks of identical chaotic oscillators with either time-discrete or time-continuous dynamics (Henon map, Lozi map, Lorenz system). We hypothesize that chimera states, in which spatial domains of coherent (synchronous) and incoherent (desynchronized) dynamics coexist, can be obtained only in networks of oscillators with nonhyperbolic chaotic attractors and cannot be found in networks of systems with hyperbolic chaotic attractors. This hypothesis is supported by analytical results and numerical simulations for hyperbolic and nonhyperbolic cases.

  7. Histogenesis of mouse sarcomas induced by implantation of polyvinyl chloride film in radiation chimeras

    International Nuclear Information System (INIS)

    Sarcomas were induced in CBA/CBA-T6T6 mouse radiation chimeras by implantation of polyvinyl chloride film subcutaneously 13 months after irradiation and injection of donor's bone marrow. Of the 12 tumors studied 11 had the recipient's karyotype and one the donor's. The formation of connective-tissue cells from bone-marrow precursors thus, evidently does not play an essential role in the histogenesis of sarcomas induced by plastics

  8. Earthquake sequencing: chimera states with Kuramoto model dynamics on directed graphs

    Science.gov (United States)

    Vasudevan, K.; Cavers, M.; Ware, A.

    2015-09-01

    Earthquake sequencing studies allow us to investigate empirical relationships among spatio-temporal parameters describing the complexity of earthquake properties. We have recently studied the relevance of Markov chain models to draw information from global earthquake catalogues. In these studies, we considered directed graphs as graph theoretic representations of the Markov chain model and analyzed their properties. Here, we look at earthquake sequencing itself as a directed graph. In general, earthquakes are occurrences resulting from significant stress interactions among faults. As a result, stress-field fluctuations evolve continuously. We propose that they are akin to the dynamics of the collective behavior of weakly coupled non-linear oscillators. Since mapping of global stress-field fluctuations in real time at all scales is an impossible task, we consider an earthquake zone as a proxy for a collection of weakly coupled oscillators, the dynamics of which would be appropriate for the ubiquitous Kuramoto model. In the present work, we apply the Kuramoto model with phase lag to the non-linear dynamics on a directed graph of a sequence of earthquakes. For directed graphs with certain properties, the Kuramoto model yields synchronization, and inclusion of non-local effects evokes the occurrence of chimera states or the co-existence of synchronous and asynchronous behavior of oscillators. In this paper, we show how we build the directed graphs derived from global seismicity data. Then, we present conditions under which chimera states could occur and, subsequently, point out the role of the Kuramoto model in understanding the evolution of synchronous and asynchronous regions. We surmise that one implication of the emergence of chimera states will lead to investigation of the present and other mathematical models in detail to generate global chimera-state maps similar to global seismicity maps for earthquake forecasting studies.

  9. Mass and charge identification of fragments detected with the Chimera Silicon-CsI(Tl) telescopes

    CERN Document Server

    Le Neindre, N

    2002-01-01

    Mass and charge identification of charged products detected with Silicon-CsI(Tl) telescopes of the Chimera apparatus is presented. An identification function, based on the Bethe-Bloch formula, is used to fit empirical correlation between Delta E and E ADC readings, in order to determine, event by event, the atomic and mass numbers of the detected charged reaction products prior to energy calibration.

  10. Chimera patterns induced by distance-dependent power-law coupling in ecological networks

    OpenAIRE

    Banerjee, Tanmoy; Dutta, Partha Sharathi; Zakharova, Anna; Schoell, Eckehard

    2016-01-01

    This paper reports the occurrence of several chimera patterns and the associated transitions among them in a network of coupled oscillators, which are connected by a long range interaction that obeys a distance-dependent power law. This type of interaction is common in physics and biology and constitutes a general form of coupling scheme, where by tuning the power-law exponent of the long range interaction the coupling topology can be varied from local via nonlocal to global coupling. To expl...

  11. Chimera states in population dynamics: networks with fragmented and hierarchical connectivities

    OpenAIRE

    Hizanidis, Johanne; Panagakou, Evangelia; Omelchenko, Iryna; Schoell, Eckehard; Hoevel, Philipp; Provata, Astero

    2015-01-01

    We study numerically the development of chimera states in networks of nonlocally coupled oscillators whose limit cycles emerge from a Hopf bifurcation. This dynamical system is inspired from population dynamics and consists of three interacting species in cyclic reactions. The complexity of the dynamics arises from the presence of a limit cycle and four fixed points. When the bifurcation parameter increases away from the Hopf bifurcation the trajectory approaches the heteroclinic invariant ma...

  12. Impact of hyperbolicity on chimera states in ensembles of nonlocally coupled chaotic oscillators

    Science.gov (United States)

    Semenova, N.; Zakharova, A.; Schöll, E.; Anishchenko, V.

    2016-06-01

    In this work we analyse nonlocally coupled networks of identical chaotic oscillators. We study both time-discrete and time-continuous systems (Henon map, Lozi map, Lorenz system). We hypothesize that chimera states, in which spatial domains of coherent (synchronous) and incoherent (desynchronized) dynamics coexist, can be obtained only in networks of chaotic non-hyperbolic systems and cannot be found in networks of hyperbolic systems. This hypothesis is supported by numerical simulations for hyperbolic and non-hyperbolic cases.

  13. Fast and reliable production, purification and characterization of heat-stable, bifunctional enzyme chimeras.

    Science.gov (United States)

    Neddersen, Mara; Elleuche, Skander

    2015-12-01

    Degradation of complex plant biomass demands a fine-regulated portfolio of glycoside hydrolases. The LE (LguI/Eco81I)-cloning approach was used to produce two enzyme chimeras CB and BC composed of an endoglucanase Cel5A (C) from the extreme thermophilic bacterium Fervidobacterium gondwanense and an archaeal β-glucosidase Bgl1 (B) derived from a hydrothermal spring metagenome. Recombinant chimeras and parental enzymes were produced in Escherichia coli and purified using a two-step affinity chromatography approach. Enzymatic properties revealed that both chimeras closely resemble the parental enzymes and physical mixtures, but Cel5A displayed lower temperature tolerance at 100°C when fused to Bgl1 independent of the conformational order. Moreover, the determination of enzymatic performances resulted in the detection of additive effects in case of BC fusion chimera. Kinetic measurements in combination with HPLC-mediated product analyses and site-directed mutation constructs indicated that Cel5A was strongly impaired when fused at the N-terminus, while activity was reduced to a slighter extend as C-terminal fusion partner. In contrast to these results, catalytic activity of Bgl1 at the N-terminus was improved 1.2-fold, effectively counteracting the slightly reduced activity of Cel5A by converting cellobiose into glucose. In addition, cellobiose exhibited inhibitory effects on Cel5A, resulting in a higher yield of cellobiose and glucose by application of an enzyme mixture (53.1%) compared to cellobiose produced from endoglucanase alone (10.9%). However, the overall release of cellobiose and glucose was even increased by catalytic action of BC (59.2%). These results indicate possible advantages of easily produced bifunctional fusion enzymes for the improved conversion of complex polysaccharide plant materials.

  14. EXAMINATION OF THE GERM CELL CHIMERA FORMING POTENTIAL OF MOUSE EMBRYONIC STEM CELLS

    Directory of Open Access Journals (Sweden)

    CÂRSTEA V. B

    2007-01-01

    Full Text Available The aim of this study was to examine the factors, which influence the chimeraforming potential of mouse embryonic stem cells (ES cells. In our work, we examinethe chimera producing ability of R1 and R1/E mouse ES cell lines. We found that thepassage number affects chimera-forming capability of the ES cells. With theincreasing of the passage number, it could be getting less chimera animal, and onlythe R1/E ES cell line derived cells could contribute to the germ cells. At first, wecompared the marker of pluripotency using immunostaining and RT PCR, but wecould not find any difference between the R1 and R1/E cell in this way. Atchromosome analysis, we found, that the number of aneuploid cells, in R1 ES cellline, dramatically increased after 10 passages. We thought that the reason is thatduring the cell division Y chromosome could not arrange correctly between the twonewly derived progeny cells. To prove our conception, we made X and YchromosomeFISH analyses. We found, that the aneuploid R1 and R1/E ES cellscontain only one X and one Y chromosome, so not the loss of Y chromosome causethe problem at the germ cell formation. At last, we made the karyotypeanalysis of R1 and R1/E ES cells at different passages. The karyotype analysisdemonstrated that in the case of R1 ES cell line, the 41 and 42-chromosomecontaining cells hold trisomy. With the increasing of the passages number, thenumber of trisomy containing aneuploid cells increased. The aneuploid ES cells cancontribute to the different tissuses of chimera animals, but cannot form viable germcells.

  15. EXAMINATION OF THE GERM CELL CHIMERA FORMING POTENTIAL OF MOUSE EMBRYONIC STEM CELLS

    Directory of Open Access Journals (Sweden)

    V.B. CÂRSTEA

    2013-12-01

    Full Text Available The aim of this study was to examine the factors, which influence the chimeraforming potential of mouse embryonic stem cells (ES cells. In our work, we examinethe chimera producing ability of R1 and R1/E mouse ES cell lines. We found that thepassage number affects chimera-forming capability of the ES cells. With theincreasing of the passage number, it could be getting less chimera animal, and onlythe R1/E ES cell line derived cells could contribute to the germ cells. At first, wecompared the marker of pluripotency using immunostaining and RT PCR, but wecould not find any difference between the R1 and R1/E cell in this way. Atchromosome analysis, we found, that the number of aneuploid cells, in R1 ES cellline, dramatically increased after 10 passages. We thought that the reason is thatduring the cell division Y chromosome could not arrange correctly between the twonewly derived progeny cells. To prove our conception, we made X and YchromosomeFISH analyses. We found, that the aneuploid R1 and R1/E ES cellscontain only one X and one Y chromosome, so not the loss of Y chromosome causethe problem at the germ cell formation. At last, we made the karyotypeanalysis of R1 and R1/E ES cells at different passages. The karyotype analysisdemonstrated that in the case of R1 ES cell line, the 41 and 42-chromosomecontaining cells hold trisomy. With the increasing of the passages number, thenumber of trisomy containing aneuploid cells increased. The aneuploid ES cells cancontribute to the different tissuses of chimera animals, but cannot form viable germcells.

  16. Mass and charge identification of fragments detected with the Chimera Silicon-CsI(Tl) telescopes

    OpenAIRE

    Neindre, N. Le; collaboration, for REVERSE

    2001-01-01

    Mass and charge identification of charged products detected with Silicon-CsI(Tl) telescopes of the Chimera apparatus is presented. An identification function, based on the Bethe-Bloch formula, is used to fit empirical correlation between Delta E and E ADC readings, in order to determine, event by event, the atomic and mass numbers of the detected charged reaction products prior to energy calibration.

  17. Mass and charge identification of fragments detected with the Chimera Silicon-CsI(Tl) telescopes

    Science.gov (United States)

    Le Neindre, N.; Alderighi, M.; Anzalone, A.; Barnà, R.; Bartolucci, M.; Berceanu, I.; Borderie, B.; Bougault, R.; Bruno, M.; Cardella, G.; Cavallaro, S.; D'Agostino, M.; Dayras, R.; de Filippo, E.; de Pasquale, D.; Geraci, E.; Giustolisi, F.; Grzeszczuk, A.; Guazzoni, P.; Guinet, D.; Iacono-Manno, M.; Italiano, A.; Kowalski, S.; Lanchais, A.; Lanzanó, G.; Lanzalone, G.; Li, S.; Lo Nigro, S.; Maiolino, C.; Manfredi, G.; Moisa, D.; Pagano, A.; Papa, M.; Paduszynski, T.; Petrovici, M.; Piasecki, E.; Pirrone, S.; Politi, G.; Pop, A.; Porto, F.; Rivet, M. F.; Rosato, E.; Russo, S.; Sambataro, S.; Sechi, G.; Simion, V.; Sperduto, M. L.; Steckmeyer, J. C.; Sutera, C.; Trifirò, A.; Tassan-Got, L.; Trimarchi, M.; Vannini, G.; Vigilante, M.; Wilczynski, J.; Wu, H.; Xiao, Z.; Zetta, L.; Zipper, W.

    2002-09-01

    Mass and charge identification of charged products detected with Silicon-CsI(Tl) telescopes of the Chimera apparatus are presented. An identification function, based on the Bethe-Bloch formula, is used to fit empirical correlations between ΔE and E ADC readings, in order to determine, event by event, the atomic and mass numbers of the detected charged reaction products prior to energy calibration.

  18. Human-animal chimeras for vaccine development: an endangered species or opportunity for the developing world?

    OpenAIRE

    Daar Abdallah S; Singer Peter A; Bhan Anant

    2010-01-01

    Abstract Background In recent years, the field of vaccines for diseases such as Human Immunodeficiency Virus (HIV) which take a heavy toll in developing countries has faced major failures. This has led to a call for more basic science research, and development as well as evaluation of new vaccine candidates. Human-animal chimeras, developed with a 'humanized' immune system could be useful to study infectious diseases, including many neglected diseases. These would also serve as an important t...

  19. Proposal of Readout Electronics for CSNS-WNS BaF2 Detector

    CERN Document Server

    Zhang, Deliang; Wang, Qi; He, Bing; Zhang, Yaxi; Qi, Xincheng; Yu, Tao; An, Qi

    2016-01-01

    BaF2 (Barium fluoride) detector is one of the experiment facilities at the under construction CSNS-WNS (White Neutron Source at China Spallation Neutron Source). It is designed for precisely measuring (n,gamma) cross section with total 92 crystal elements and completely 4 pi steradian coverage. In this proposal for readout electronics, waveform digitizing technique with 1GSps sampling rate and 12-bit resolution is adopted to precisely capture the detector signal. To solve the problem of massive data readout and processing, the readout electronics system is designed into a distributed architecture with 4 PXIe crates. The digitized detector's signal is concentrated to PXIe crate controller through PCIe bus on backplane and transmitted to data acquisition system over Gigabit Ethernet in parallel. Besides, clock and trigger can be fanned out synchronously to each electronic channel over a high-precision distributing network. Test results showed that the prototype of the readout electronics system achieved good pe...

  20. Human-animal chimera: a neuro driven discussion? Comparison of three leading European research countries.

    Science.gov (United States)

    Cabrera Trujillo, Laura Yenisa; Engel-Glatter, Sabrina

    2015-06-01

    Research with human-animal chimera raises a number of ethical concerns, especially when neural stem cells are transplanted into the brains of non-human primates (NHPs). Besides animal welfare concerns and ethical issues associated with the use of embryonic stem cells, the research is also regarded as controversial from the standpoint of NHPs developing cognitive or behavioural capabilities that are regarded as "unique" to humans. However, scientists are urging to test new therapeutic approaches for neurological diseases in primate models as they better mimic human physiology than all current animal models. As a response, various countries have issued reports on the topic. Our paper summarizes the ethical issues raised by research with human-animal brain chimeras and compares the relevant regulatory instruments and different recommendations issued in national reports from three important European research nations: Germany, Switzerland and the United Kingdom. We assess and discuss the focus and priorities set by the different reports, review various reasons for and perspectives on the importance of the brain in chimera research, and identify critical points in the reports that warrant further specification and debate.

  1. Chimeras of Delta6-fatty acid and Delta8-sphingolipid desaturases.

    Science.gov (United States)

    Libisch, B; Michaelson, L V; Lewis, M J; Shewry, P R; Napier, J A

    2000-12-29

    The Borago officinalis Delta6 fatty acid desaturase (Boofd6) shares 58% identity in its amino acid sequence with Boofd8, a Delta8 sphingolipid desaturase from the same plant species. In order to localise the distinct catalytic properties of Boofd6 and Boofd8 to individual regions within them, a set of chimeras of these two enzymes were constructed and expressed in yeast. Chimera 2 is different from the other chimeras and Boofd6 in that it did not have any detectable desaturase activity on 18 carbon fatty acids. However, it desaturated C16 palmitoleic and C14 myristoleic acid, and the conversion rate for the later one was more than three times higher than that of Boofd6. These results suggest that the predicted membrane helices 1 and 2 of Boofd6 are involved in forming the substrate-binding site. This site appears to place constraints on the chain length of fatty acid substrates, which is similar to hydrophobic substrate binding pockets. PMID:11162428

  2. Chimera grids in the simulation of three-dimensional flowfields in turbine-blade-coolant passages

    Science.gov (United States)

    Stephens, M. A.; Rimlinger, M. J.; Shih, T. I.-P.; Civinskas, K. C.

    1993-01-01

    When computing flows inside geometrically complex turbine-blade coolant passages, the structure of the grid system used can affect significantly the overall time and cost required to obtain solutions. This paper addresses this issue while evaluating and developing computational tools for the design and analysis of coolant-passages, and is divided into two parts. In the first part, the various types of structured and unstructured grids are compared in relation to their ability to provide solutions in a timely and cost-effective manner. This comparison shows that the overlapping structured grids, known as Chimera grids, can rival and in some instances exceed the cost-effectiveness of unstructured grids in terms of both the man hours needed to generate grids and the amount of computer memory and CPU time needed to obtain solutions. In the second part, a computational tool utilizing Chimera grids was used to compute the flow and heat transfer in two different turbine-blade coolant passages that contain baffles and numerous pin fins. These computations showed the versatility and flexibility offered by Chimera grids.

  3. Allogeneic radiation chimeras respond to TNP-modified donor and host targets

    International Nuclear Information System (INIS)

    Tolerance to major histocompatibility antigens as well as the ability to mount a cytotoxic response to hapten-modified cells of bone marrow donor and host origin was studied in allogeneic radiation chimeras. Lethally irradiated (C57BL/6 x DBA/2)F1 hosts reconstituted with anti-Thy 1.2 + C-treated bone marrow from (C57BL/6 x CBA)F1 mice showed tolerance to the MHC antigens of the three parental strains as measured by MLC and CML assay. The chimeras responded normally to unrelated allogeneic cells. Chimeric animals generated a cytotoxic response to hapten-modified cells of both donor (CBA) and host (DBA/2) haplotypes, as well as to C57BL/6, demonstrating that tolerance to the hapten-presenting host haplotype is sufficient to allow a cytotoxic antihapten response, and that processing through a semiallogeneic host environment does not affect the ability to generate a response to hapten in conjunction with self-determinants. Chimeras failed to mount a cytotoxic response to hapten presented on nontolerated allogeneic spleen cells

  4. Pichia pastoris as a host for secretion of toxic saporin chimeras.

    Science.gov (United States)

    Lombardi, Alessio; Bursomanno, Sara; Lopardo, Teresa; Traini, Roberta; Colombatti, Marco; Ippoliti, Rodolfo; Flavell, David J; Flavell, Sopsamorn U; Ceriotti, Aldo; Fabbrini, Maria Serena

    2010-01-01

    Most of the targeting moieties, such as antibody fragments or growth factor domains, used to construct targeted toxins for anticancer therapy derive from secretory proteins. These normally fold in the oxidative environment of the endoplasmic reticulum, and hence their folding in bacterial cells can be quite inefficient. For instance, only low amounts of properly folded antimetastatic chimera constituted by the amino-terminal fragment of human urokinase (ATF) fused to the plant ribosome-inactivating protein saporin could be recovered. ATF-saporin was instead secreted efficiently when expressed in eukaryotic cells protected from autointoxication with neutralizing anti-saporin antibodies. Pichia pastoris is a microbial eukaryotic host where these domains can fold into a transport-competent conformation and reach the extracellular medium. We show here that despite some host toxicity codon-usage optimization greatly increased the expression levels of active saporin but not those of an active-site mutant SAP-KQ in GS115 (his4) strain. The lack of any toxicity associated with expression of the latter confirmed that toxicity is due to saporin catalytic activity. Nevertheless, GS115 (his4) cells in flask culture secreted 3.5 mg/L of a histidine-tagged ATF-saporin chimera showing an IC(50) of 6 x 10(-11) M against U937 cells, thus demonstrating the suitability of this expression platform for secretion of toxic saporin-based chimeras. PMID:19786581

  5. Flexible and rapid construction of viral chimeras applied to hepatitis C virus.

    Science.gov (United States)

    McClure, C Patrick; Urbanowicz, Richard A; King, Barnabas J; Cano-Crespo, Sara; Tarr, Alexander W; Ball, Jonathan K

    2016-09-01

    A novel and broadly applicable strategy combining site-directed mutagenesis and DNA assembly for constructing seamless viral chimeras is described using hepatitis C virus (HCV) as an exemplar. Full-length HCV genomic cloning cassettes, which contained flexibly situated restriction endonuclease sites, were prepared via a single, site-directed mutagenesis reaction and digested to receive PCR-amplified virus envelope genes by In-Fusion cloning. Using this method, we were able to construct gene-shuttle cassettes for generation of cell culture-infectious JFH-1-based chimeras containing genotype 1-3 E1E2 genes. Importantly, using this method we also show that E1E2 clones that were not able to support cell entry in the HCV pseudoparticle assay did confer entry when shuttled into the chimeric cell culture chimera system. This method can be easily applied to other genes of study and other viruses and, as such, will greatly simplify reverse genetics studies of variable viruses.

  6. Design of hyperthermophilic lipase chimeras by key motif-directed recombination.

    Science.gov (United States)

    Zhou, Xiaoli; Gao, Le; Yang, Guangyu; Liu, Donglai; Bai, Aixi; Li, Binchun; Deng, Zixin; Feng, Yan

    2015-02-01

    Recombination of diverse natural evolved domains within a superfamily offers greater opportunity for enzyme function leaps. How to recombine protein modules from distant parents with less disruption in cross-interfaces is a challenging issue. Here, we identified the existence of a key motif, the sequence VVSVN(D)YR, within a structural motif ψ loop in the α/β-hydrolase fold superfamily, by using a MEME server and the PROMOTIF program. To obtain thermostable lipase-like enzymes, two chimeras were engineered at the key motif regions through recombination of domains from a mesophilic lipase and a hyperthermophilic esterase/peptidase with amino acid identity less than 21 %. The chimeras retained the desirable substrate preference of their mesophilic parent and exhibited more than 100-fold increased thermostability at 50 °C. Through site-directed mutation, we further improved activity of the chimera by 4.6-fold. The recombination strategy presented here enables the creation of novel catalysts. PMID:25530200

  7. Neutron detector

    Science.gov (United States)

    Stephan, Andrew C.; Jardret; Vincent D.

    2011-04-05

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  8. Histopathological changes in exocrine glands of murine transplantation chimeras. II: Sjögren's syndrome-like exocrinopathy in mice without lupus nephritis. A model of primary Sjögren's syndrome

    DEFF Research Database (Denmark)

    Ussing, Anne Phaff; Prause, J.U.; Sørensen, Inger;

    1992-01-01

    Autoimmune disease, primary Sjögren's syndrome, transplantation chimeras, experimental model, exocrinopathy, inbred mouse strains......Autoimmune disease, primary Sjögren's syndrome, transplantation chimeras, experimental model, exocrinopathy, inbred mouse strains...

  9. Sequential analysis of the virus-immune responder characteristics of thymocytes from F1→parent radiation chimeras

    International Nuclear Information System (INIS)

    The virus-immune responder characteristics of thymocytes, spleen and lymph node (LN) cells from (P1 x P2)F1→P1 radiation chimeras have been examined sequentially at weekly intervals. Adoptively-transferred thymocytes generate strong cytotoxic thymus-derived lymphocyte (CTL) responses from 28 to 100 days after reconstitution with bone marrow, which are almost invariably restricted to recognition of virus presented in the context of P1. This pattern of H-2 restriction is also maintained for spleen and LN cells from the [(H-2sup(kxd)F1→H-2sup(k)] and [(H-2sup(kxb)F1→H-2sup(k)] combinations but there is random emergence of reactivity to H-2sup(k)+virus for peripheral lymphoid cells from [(H-2sup(kxb)F1→H-2sup(b)] chimeras. Treatment of established [(P1xP2)]F1→P1] chimeras with a low dose of cyclophosphamide (Cy) did not lead to the emergence of significant CTL effector function for P2 + virus. Also, administration of a large dose of Cy prior to irradiation of the chimera recipients did not modify the H-2 restriction profile of the chimera, though the level of CTL responsiveness associated with the appropriate H-2 type was apparently enhanced. (Auth.)

  10. Bacterial membrane activity of a-peptide/b-peptoid chimeras: Influence of amino acid composition and chain length on the activity against different bacterial strains

    DEFF Research Database (Denmark)

    Hein-Kristensen, Line; Knapp, Kolja M; Franzyk, Henrik;

    2011-01-01

    acid only had a minor effect on MIC values, whereas chain length had a profound influence on activity. All chimeras were less active against Serratia marcescens (MICs above 46 μM). The chimeras were bactericidal and induced leakage of ATP from Staphylococcus aureus and S. marcescens with similar time...... of onset and reduction in the number of viable cells. EDTA pre-treatment of S. marcescens and E. coli followed by treatment with chimeras resulted in pronounced killing indicating that disintegration of the Gram-negative outer membrane eliminated innate differences in susceptibility. Chimera chain length...... of the bacterial cell envelope, and the outer membrane may act as a barrier in Gram-negative bacteria. The tolerance of S. marcescens to chimeras may be due to differences in the composition of the lipopolysaccharide layer also responsible for its resistance to polymyxin B....

  11. Improvements in the in-beam {gamma}-ray spectroscopy provided by an ancillary detector coupled to a Ge {gamma}-spectrometer: the DIAMANT-EUROGAM II example

    Energy Technology Data Exchange (ETDEWEB)

    Scheurer, J.N. [Bordeaux-1 Univ., 33 - Gradignan (France). Centre d`Etudes Nucleaires; Aiche, M. [Bordeaux-1 Univ., 33 - Gradignan (France). Centre d`Etudes Nucleaires; Aleonard, M.M. [Bordeaux-1 Univ., 33 - Gradignan (France). Centre d`Etudes Nucleaires; Barreau, G. [Bordeaux-1 Univ., 33 - Gradignan (France). Centre d`Etudes Nucleaires; Bourgine, F. [Bordeaux-1 Univ., 33 - Gradignan (France). Centre d`Etudes Nucleaires; Boivin, D. [Bordeaux-1 Univ., 33 - Gradignan (France). Centre d`Etudes Nucleaires; Cabaussel, D. [Bordeaux-1 Univ., 33 - Gradignan (France). Centre d`Etudes Nucleaires; Chemin, J.F. [Bordeaux-1 Univ., 33 -Gradignan (France). Centre d`Etudes Nucleaires; Doan, T.P. [Bordeaux-1 Univ., 33 -Gradignan (France). Centre d`Etudes Nucleaires; Goudour, J.P. [Bordeaux-1 Univ., 33 - Gradignan (France). Centre d`Etudes Nucleaires; Harston, M. [Bordeaux-1 Univ., 33 - Gradignan (France). Centre d`Etudes Nucleaires; Brondi, A. [Istituto Nazionale di Fisica Nucleare, Naples (Italy)]|[Naples Univ. (Italy). Dipt. di Scienze Fisiche; La Rana, G. [Istituto Nazionale di Fisica Nucleare, Naples (Italy)]|[Naples Univ. (Italy). Dipt. di Scienze Fisiche; Moro, R. [Istituto Nazionale di Fisica Nucleare, Naples (Italy)]|[Naples Univ. (Italy). Dipt. di Scienze Fisiche; Vardaci, E. [Istituto Nazionale di Fisica Nucleare, Naples (Italy)]|[Naples Univ. (Italy). Dipt. di Scienze Fisiche; Curien, D. [CRN-IN2P3, Strasbourg (France)

    1997-02-01

    For the first time the 4{pi} {gamma}-ray spectrometer EUROGAM II has been coupled to a 4{pi} light charged particle detector array, DIAMANT, during a test experiment on the reaction {sup 32}S + {sup 58}Ni at 120 MeV beam energy. A very large improvement in the peak-to-background ratio of the {gamma}-spectra has been found when EUROGAM II is triggered by DIAMANT to select an exit channel. A simple algebra has been developed which provides theoretical estimates in good agreement with these experimental results. It is demonstrated that, depending on both the {gamma}-spectrometer and ancillary detector performances, much better peak-to-background can be obtained by such a coupling. For the same peak-to-background ratio, the use of an ancillary detector allows for a lower {gamma}-ray coincidence level and therefore improves the statistics. Ways to select the most appropriate ancillary detector are given. The ability of the ancillary detector to provide a total Doppler shift correction is crucial for the improvement of the peak-to-background ratio. (orig.).

  12. Phenotypic characterization of early events of thymus repopulation in radiation bone marrow chimeras

    International Nuclear Information System (INIS)

    The phenotype of murine thymocytes repopulating the thymus of radiation bone marrow chimeras shortly after irradiation and bone marrow reconstitution was analyzed by immunofluorescence and flow microfluorometry. Thymuses in these chimeras, while essentially devoid of lymphoid cells at day 7, were repopulated by days 10 to 12 after irradiation. It was found that this initial repopulation arose from a radioresistant intrathymic precursor that expanded to an almost complete complement of host-type thymocytes. However, these host-derived thymocytes were unusual in that they were relatively deficient in Lyt 1+2- and peanut agglutinin ''dull'' cells as compared with normal thymocytes. Donor bone-marrow-derived cells first appeared in the irradiated chimeric thymuses between days 12 and 15 after irradiation and bone marrow transfer. By day 19, chimeric thymuses contained more than 98% donor cells. This course was identical for three chimeric combinations, each made across different genetic barriers. In contrast to the cells that populate the fetal thymus during normal ontogeny, the first donor bone-marrow-derived cells that can be detected within the irradiated chimeric thymuses already expressed phenotypically normal adult T cell subpopulations in that they contained significant numbers both of Lyt 1+2- and of Lyt 1+2+ thymocytes. Thus, the Lyt phenotype of donor cells that initially repopulate an adult thymus after irradiation is markedly different from the Lyt phenotype of cells that initially populate the fetal thymus. The differences between adult and fetal thymic development that are observed in radiation bone marrow chimeras may be important in our understanding of T cell differentiation in these animals

  13. Anti-bacterial immunity to Listeria monocytogenes in allogeneic bone marrow chimera in mice

    International Nuclear Information System (INIS)

    Protection and delayed-type hypersensitivity (DTH) to the facultative intracellular bacterium Listeria monocytogenes (L.m.) were studied in allogeneic and syngeneic bone marrow chimeras. Lethally irradiated AKR (H-2k) mice were successfully reconstituted with marrow cells from C57BL/10 (B10) (H-2b), B10 H-2-recombinant strains or syngeneic mice. Irradiated AKR mice reconstituted with marrow cells from H-2-compatible B10.BR mice, [BR----AKR], as well as syngeneic marrow cells, [AKR----AKR], showed a normal level of responsiveness to the challenge stimulation with the listeria antigens when DTH was evaluated by footpad reactions. These mice also showed vigorous activities in acquired resistance to the L.m. By contrast, chimeric mice that had total or partial histoincompatibility at the H-2 determinants between donor and recipient, [B10----AKR], [B10.AQR----AKR], [B10.A(4R)----AKR], or [B10.A(5R)----AKR], were almost completely unresponsive in DTH and antibacterial immunity. However, when [B10----AKR] H-2-incompatible chimeras had been immunized with killed L.m. before challenge with live L.m., these mice manifested considerable DTH and resistance to L.m. These observations suggest that compatibility at the entire MHC between donor and recipient is required for bone marrow chimeras to be able to manifest DTH and protection against L.m. after a short-term immunization schedule. However, this requirement is overcome by a preceding or more prolonged period of immunization with L.m. antigens. These antigens, together with marrow-derived antigen-presenting cells, can then stimulate and expand cell populations that are restricted to the MHC (H-2) products of the donor type

  14. Plasmodium vivax Promiscuous T-Helper Epitopes Defined and Evaluated as Linear Peptide Chimera Immunogens

    Science.gov (United States)

    Caro-Aguilar, Ivette; Rodríguez, Alexandra; Calvo-Calle, J. Mauricio; Guzmán, Fanny; De la Vega, Patricia; Elkin Patarroyo, Manuel; Galinski, Mary R.; Moreno, Alberto

    2002-01-01

    Clinical trials of malaria vaccines have confirmed that parasite-derived T-cell epitopes are required to elicit consistent and long-lasting immune responses. We report here the identification and functional characterization of six T-cell epitopes that are present in the merozoite surface protein-1 of Plasmodium vivax (PvMSP-1) and bind promiscuously to four different HLA-DRB1∗ alleles. Each of these peptides induced lymphoproliferative responses in cells from individuals with previous P. vivax infections. Furthermore, linear-peptide chimeras containing the promiscuous PvMSP-1 T-cell epitopes, synthesized in tandem with the Plasmodium falciparum immunodominant circumsporozoite protein (CSP) B-cell epitope, induced high specific antibody titers, cytokine production, long-lasting immune responses, and immunoglobulin G isotype class switching in BALB/c mice. A linear-peptide chimera containing an allele-restricted P. falciparum T-cell epitope with the CSP B-cell epitope was not effective. Two out of the six promiscuous T-cell epitopes exhibiting the highest anti-peptide response also contain B-cell epitopes. Antisera generated against these B-cell epitopes recognize P. vivax merozoites in immunofluorescence assays. Importantly, the anti-peptide antibodies generated to the CSP B-cell epitope inhibited the invasion of P. falciparum sporozoites into human hepatocytes. These data and the simplicity of design of the chimeric constructs highlight the potential of multimeric, multistage, and multispecies linear-peptide chimeras containing parasite promiscuous T-cell epitopes for malaria vaccine development. PMID:12065487

  15. Commentary on 'The arms of the chimeras' by Béatrice Ithier.

    Science.gov (United States)

    Abram, Jan

    2016-04-01

    In this Commentary I will first of all summarise my understanding of the proposal set out by Béatrice Ithier concerning her concept of the 'chimera'. The main part of my essay will focus on Ithier's claim that her concept of the chimera could be described as a 'mental squiggle' because it corresponds to Winnicott's work illustrated in his book 'Therapeutic Consultations' (1971). At the core of Ithier's chimera is the notion of a traumatic link between analyst and patient, which is the reason she enlists the work of Winnicott. I will argue, however, that Ithier's claim is based on a misperception of the theory that underpins Winnicott's therapeutic consultations because, different from Ithier's clinical examples of work with traumatised patients, Winnicott is careful to select cases who are from an 'average expectable environment' i.e. a good enough family. Moreover, Winnicott does not refer to any traumatic affinity with his patients, or to experiencing a quasi-hallucinatory state of mind during the course of the consultations. These aspects are not incorporated into his theory. In contrast (to the concept Ithier attempts to advance), Winnicott's squiggle game constitutes an application of psychoanalysis intended as a diagnostic consultation. In that sense Winnicott's therapeutic consultations are comparable with the ordinary everyday work between analyst and analysand in a psychoanalytic treatment. My Commentary concludes with a question concerning the distinction between the ordinary countertransference in working with patients who are thinking symbolically in contrast to an extraordinary countertransference that I suggest is more likely to arise with patients who are traumatised and thus functioning at a borderline or psychotic level. PMID:27112824

  16. Formation of germline chimera Gaok chicken used circulation primordial germ cells (circulation PGCs fresh and thawed

    Directory of Open Access Journals (Sweden)

    Kostaman T

    2014-03-01

    Full Text Available Formation of germline chimeras by transfer of chicken primordial germ cells (PGCs is one of the effective techniques for preservation and regeneration of genetic resources in chickens. This study attempted to form germline chimeras of Gaok chicken buy purifying circulated PGCs of donor embryo before it is transferred to the recipient (White Leghorn chickens=WL and studied the ability of recipient embryo on survival in incubators, and hatchability. This study used 200 fertile eggs of Gaok and 90 fertile WL breed all of the eggs was incubated at 380C and 60% humidity in a portable incubator. PGCs-circulation of the blood collected Gaok embryos at stage 14-16 were taken from the dorsal aorta, and then purified by centrifugation method using nycodenz. PGCs-circulation results further purification frozen in liquid nitrogen before being transferred to the recipient embryo. The results showed that for the development of embryos transferred to the fresh circulation of PGCs-circulation as many as 25 cells can survive up to day 14, while one of the transferred of 50 and 100 cells into recipient embryos was hatched (10%. On the contrari recipient embryos that are transferred to the frozen PGCs-circulation the embryos development was shorter, and only survived until day 10th (treatment 25 cells, day 14th (treatment of 50 cells and day 17th (treatment of 100 cells. It is concluded that the amount of PGCs-circulation embryos transferred to the recipient is one factor that influence the success of the development germline chimeras.

  17. Explosive synchronization in clustered scale-free networks: Revealing the existence of chimera state

    Science.gov (United States)

    Berec, V.

    2016-02-01

    The collective dynamics of Kuramoto oscillators with a positive correlation between the incoherent and fully coherent domains in clustered scale-free networks is studied. Emergence of chimera states for the onsets of explosive synchronization transition is observed during an intermediate coupling regime when degree-frequency correlation is established for the hubs with the highest degrees. Diagnostic of the abrupt synchronization is revealed by the intrinsic spectral properties of the network graph Laplacian encoded in the heterogeneous phase space manifold, through extensive analytical investigation, presenting realistic MC simulations of nonlocal interactions in discrete time dynamics evolving on the network.

  18. Multitasking for flows about multiple body configurations using the chimera grid scheme

    Science.gov (United States)

    Dougherty, F. C.; Morgan, R. L.

    1987-01-01

    The multitasking of a finite-difference scheme using multiple overset meshes is described. In this chimera, or multiple overset mesh approach, a multiple body configuration is mapped using a major grid about the main component of the configuration, with minor overset meshes used to map each additional component. This type of code is well suited to multitasking. Both steady and unsteady two dimensional computations are run on parallel processors on a CRAY-X/MP 48, usually with one mesh per processor. Flow field results are compared with single processor results to demonstrate the feasibility of running multiple mesh codes on parallel processors and to show the increase in efficiency.

  19. Transfer of experimental allergic encephalomyelitis to bone marrow chimeras. Endothelial cells are not a restricting element

    International Nuclear Information System (INIS)

    The adoptive transfer of clinical and histopathologic signs of experimental allergic encephalomyelitis (EAE) requires MHC compatibility between cell donor and cell recipient. The results of adoptive transfer studies using F1 to parent bone marrow chimeras as recipients of parental-derived BP-sensitive spleen cells indicate that this restriction is not expressed at the level of the endothelial cell but is confined to the cells of bone marrow derivation. Furthermore, these results indicate that the development of EAE is not dependent on the activity of MHC-restricted cytotoxic cells

  20. Self-renewal of pulmonary alveolar macrophages: evidence from radiation chimera studies

    International Nuclear Information System (INIS)

    Radiation-induced chimeric mice were used to study the origin of pulmonary alveolar macrophages. Unlike in other studies, these radiation chimeras were prepared by using a special fractionated irradiation regimen to minimize the killing of alveolar macrophage colony-forming cells, putative local stem cells. For this study CBA mice with or without T6 chromosome marker were used. Under this experimental condition, the majority of alveolar macrophages in mitosis are of host origin even after 45 weeks. These data suggest that alveolar macrophages are a self-renewing population under normal steady-state conditions

  1. Core Collapse Supernovae using CHIMERA: Gravitational Radiation from Non-Rotating Progenitors

    CERN Document Server

    Yakunin, Konstantin; Mezzacappa, Anthony; Bruenn, Stephen W; Lee, Ching-Tsai; Chertkow, Merek A; Hix, W Raphael; Blondin, John M; Lentz, Eric J; Messer, O E Bronson; Yoshida, Shin

    2010-01-01

    The CHIMERA code is a multi-dimensional multi-physics engine dedicated primarily to the simulation of core collapse supernova explosions. One of the most important aspects of these explosions is their capacity to produce gravitational radiation that is detectable by Earth-based laser-interferometric gravitational wave observatories such as LIGO and VIRGO. We present here preliminary gravitational signatures of two-dimensional models with non-rotating progenitors. These simulations exhibit explosions, which are followed for more than half a second after stellar core bounce.

  2. Resistance to infection with Eimeria vermiformis in mouse radiation chimeras is determined by donor bone-marrow cells

    International Nuclear Information System (INIS)

    The course of infection with Eimeria vermiformis was determined in BALB/b, BALB/c, and C57BL/10ScSn (B10) mice and in radiation chimeras prepared from the H-2-compatible BALB/b and B10 mice. The BALB strains, irrespective of H-2 haplotype, were resistant, the B10 mice were susceptible, and in the chimeras infection was characterized by the genotype of the donated bone-marrow cells and not by the phenotype of the recipient. Thus, the genetic control of relative resistance or susceptibility to infection with this parasite is expressed through bone-marrow-derived cells

  3. CLIC Detector Power Requirements

    CERN Document Server

    Gaddi, A

    2013-01-01

    An estimate for the CLIC detector power requirements is outlined starting from the available data on power consumptions of the four LHC experiments and considering the differences between a typical LHC Detector (CMS) and the CLIC baseline detector concept. In particular the impact of the power pulsing scheme for the CLIC Detector electronics on the overall detector consumption is considered. The document will be updated with the requirements of the sub-detector electronics once they are more defined.

  4. The HERMES Recoil Detector

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Weilin [II. Physikalisches Institut, JLU Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany)

    2008-07-01

    The HERMES Collaboration at HERA constructed and installed a new Recoil Detector to upgrade the existed spectrometer. This detector is designed to measure recoil protons in hard exclusive processes which provide access to the orbital angular momentum of quarks. The Recoil Detector consists of a silicon detector surrounding the target cell inside the beam vacuum, a scintillating fiber tracker and a photon detector. All three detectors are located inside a solenoidal magnet which provides a 1 T longitudinal magnetic field. The Recoil Detector was installed in January 2006 and data taking lasted until the end of HERA operation in June 2007. Results on the detector performance will be presented here.

  5. Improved germanium well detectors

    International Nuclear Information System (INIS)

    Germanium well detectors with metal surface barrier contact are comparable for general use with conventional germanium coaxial detectors. They offer very high sensitivity, the highest presently available

  6. MUON DETECTOR

    CERN Multimedia

    F. Gasparini

    DT As announced in the previous Bulletin MU DT completed the installation of the vertical chambers of barrel wheels 0, +1 and +2. 242 DT and RPC stations are now installed in the negative barrel wheels. The missing 8 (4 in YB-1 and 4 in YB-2) chambers can be installed only after the lowering of the two wheels into the UX cavern, which is planned for the last quarter of the year. Cabling on the surface of the negative wheels was finished in May after some difficulties with RPC cables. The next step was to begin the final commissioning of the wheels with the final trigger and readout electronics. Priority was giv¬en to YB0 in order to check everything before the chambers were covered by cables and services of the inner detectors. Commissioning is not easy since it requires both activity on the central and positive wheels underground, as well as on the negative wheels still on the surface. The DT community is requested to commission the negative wheels on surface to cope with a possible lack of time a...

  7. Inherited effects from irradiated mouse immature oocytes detected in aggregation embryo chimeras

    International Nuclear Information System (INIS)

    Data obtained using the mouse-preimplantation-embryo-chimera assay are presented that show a transmitted effect following low-dose irradiation of immature oocytes in vivo. Six-week-old female mice were irradiated using 137Cs-γ-rays (0.05 Gy, 0.15 Gy, and unexposed controls). At 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 weeks post exposure, the mice were mated and aggregation chimeras made from the 4-cell embryos. Three independent experiments have now been carried out, all showing a significant embryonic cell-proliferation disadvantage of the embryos obtained from the females treated 7 weeks previously, i.e., embryos from oocytes that were immature at the time of radiation exposure. No effect was detected at 1-6 weeks when embryos were obtained from maturing oocytes. Also, the effect was not seen at 8, 9, 10, 11, and 12 weeks post exposure. The implications of these results are discussed in the light of previous studies on mouse oocytes

  8. Survival of allografts from bone marrow donors in temporary dog radiation chimeras

    International Nuclear Information System (INIS)

    Complete radiation chimeras accept indefinitely a skin or a kidney graft from the bone marrow (BM) donor. The advantages of this method of inducing graft acceptance are that it does not require the use of toxic post-operative immunosuppressive agents and that the immune reactivity against antigens other than the ones carried by the BM donor remains intact. The disadvantages of this approach are that supralethal total body irradiation (TBI) causes toxicity and that allogeneic BM cells can cause lethal Graft versus Host reactions. Attempts were made to diminish the significance of these disadvantages by using lower dose TBI and giving fewer BM cells. It is shown that, in dogs, 7.5 Gy TBI followed by 4 X 108 BM cells.kg-1 body weight of a DLA identical sibling leads to the development of complete radiation chimeras. The exclusive presence of donor type haemopoiesis can be demonstrated by determinations of 'informative' genetic markers, i.e., markers that show different genotypes in donor and recipient. (Auth.)

  9. Characteristics of macrophages in irradiation chimeras in mice reconstituted with allogeneic bone marrow cells

    International Nuclear Information System (INIS)

    Biological and immunological characteristics of the reticuloendothelial system of irradiation bone marrow chimeric mice and macrophages collected from various tissue sources of the mice were studied. The chimeras showed comparable activities in carbon clearance to those of normal donor or recipient mice. The macrophages from spleen, lymph node, bone marrow, peripheral blood, liver, peritoneal cavity, and lung were demonstrated to be of donor marrow origin. They showed almost the same enzyme activities and phagocytic capability of sheep erythrocytes (SRBC, E), SRBC sensitized with anti-SRBC IgG (EA), and SRBC sensitized with anti-SRBC IgM and coated with complement (EAC) as those of normal mice. Proportions of Fc receptor and complement receptor-positive cells are also in normal range. In addition, the antigen-presenting capability of the chimeric macrophages for in vitro primary antibody response to SRBC was intact. These observations suggest that the reticuloendothelial system and macrophages of allogeneic bone marrow chimeras where donor and recipient differ at the major histocompatibility complex have no defect so far as could be ascertained by the present study

  10. Ethical questions concerning research on human embryos, embryonic stem cells and chimeras.

    Science.gov (United States)

    Bobbert, Monika

    2006-12-01

    Research using human embryos and embryonic stem cells is viewed as important for various reasons. Apart from questions concerning legal regulations, numerous ethical objections are raised pertaining to the use of surplus embryos from reproductive medicine as well as the creation of embryos and stem cells through cloning. In the hopes of avoiding ethical problems, alternatives have been proposed including the extraction of egg cells from "dead" embryos derived from in vitro fertilization procedures, the extraction of pluripotent stem cells from blastocysts, technologies such as "altered nuclear transfer" (ANT) and "oocyte-assisted reprogramming" (ANT-OAR) as well as parthenogenesis. Initial ethical assessments show that certain questions pertaining to such strategies have remained unanswered. Furthermore, with the help of new or more differentiated biotechnological procedures, it is possible to create chimeras and hybrids in which human and non-human cells are combined. Human-animal chimeras, in which gametes or embryonic tissue have been mixed with embryonic or adult stem cells, demonstrate a different "quality" and "degree of penetration" from those produced in previous experiments. Not only does this have consequences regarding questions of patentability, this situation also raises fundamental questions concerning the human being's self image, the concept of person, identity and species and the moral rights and duties that are connected with such concepts. There is a need for legal regulation, on the national as well as the international level.

  11. Proteomic Analysis Reveals the Leaf Color Regulation Mechanism in Chimera Hosta "Gold Standard" Leaves.

    Science.gov (United States)

    Yu, Juanjuan; Zhang, Jinzheng; Zhao, Qi; Liu, Yuelu; Chen, Sixue; Guo, Hongliang; Shi, Lei; Dai, Shaojun

    2016-01-01

    Leaf color change of variegated leaves from chimera species is regulated by fine-tuned molecular mechanisms. Hosta "Gold Standard" is a typical chimera Hosta species with golden-green variegated leaves, which is an ideal material to investigate the molecular mechanisms of leaf variegation. In this study, the margin and center regions of young and mature leaves from Hosta "Gold Standard", as well as the leaves from plants after excess nitrogen fertilization were studied using physiological and comparative proteomic approaches. We identified 31 differentially expressed proteins in various regions and development stages of variegated leaves. Some of them may be related to the leaf color regulation in Hosta "Gold Standard". For example, cytosolic glutamine synthetase (GS1), heat shock protein 70 (Hsp70), and chloroplastic elongation factor G (cpEF-G) were involved in pigment-related nitrogen synthesis as well as protein synthesis and processing. By integrating the proteomics data with physiological results, we revealed the metabolic patterns of nitrogen metabolism, photosynthesis, energy supply, as well as chloroplast protein synthesis, import and processing in various leaf regions at different development stages. Additionally, chloroplast-localized proteoforms involved in nitrogen metabolism, photosynthesis and protein processing implied that post-translational modifications were crucial for leaf color regulation. These results provide new clues toward understanding the mechanisms of leaf color regulation in variegated leaves. PMID:27005614

  12. Proteomic Analysis Reveals the Leaf Color Regulation Mechanism in Chimera Hosta “Gold Standard” Leaves

    Directory of Open Access Journals (Sweden)

    Juanjuan Yu

    2016-03-01

    Full Text Available Leaf color change of variegated leaves from chimera species is regulated by fine-tuned molecular mechanisms. Hosta “Gold Standard” is a typical chimera Hosta species with golden-green variegated leaves, which is an ideal material to investigate the molecular mechanisms of leaf variegation. In this study, the margin and center regions of young and mature leaves from Hosta “Gold Standard”, as well as the leaves from plants after excess nitrogen fertilization were studied using physiological and comparative proteomic approaches. We identified 31 differentially expressed proteins in various regions and development stages of variegated leaves. Some of them may be related to the leaf color regulation in Hosta “Gold Standard”. For example, cytosolic glutamine synthetase (GS1, heat shock protein 70 (Hsp70, and chloroplastic elongation factor G (cpEF-G were involved in pigment-related nitrogen synthesis as well as protein synthesis and processing. By integrating the proteomics data with physiological results, we revealed the metabolic patterns of nitrogen metabolism, photosynthesis, energy supply, as well as chloroplast protein synthesis, import and processing in various leaf regions at different development stages. Additionally, chloroplast-localized proteoforms involved in nitrogen metabolism, photosynthesis and protein processing implied that post-translational modifications were crucial for leaf color regulation. These results provide new clues toward understanding the mechanisms of leaf color regulation in variegated leaves.

  13. Proteomic Analysis Reveals the Leaf Color Regulation Mechanism in Chimera Hosta “Gold Standard” Leaves

    Science.gov (United States)

    Yu, Juanjuan; Zhang, Jinzheng; Zhao, Qi; Liu, Yuelu; Chen, Sixue; Guo, Hongliang; Shi, Lei; Dai, Shaojun

    2016-01-01

    Leaf color change of variegated leaves from chimera species is regulated by fine-tuned molecular mechanisms. Hosta “Gold Standard” is a typical chimera Hosta species with golden-green variegated leaves, which is an ideal material to investigate the molecular mechanisms of leaf variegation. In this study, the margin and center regions of young and mature leaves from Hosta “Gold Standard”, as well as the leaves from plants after excess nitrogen fertilization were studied using physiological and comparative proteomic approaches. We identified 31 differentially expressed proteins in various regions and development stages of variegated leaves. Some of them may be related to the leaf color regulation in Hosta “Gold Standard”. For example, cytosolic glutamine synthetase (GS1), heat shock protein 70 (Hsp70), and chloroplastic elongation factor G (cpEF-G) were involved in pigment-related nitrogen synthesis as well as protein synthesis and processing. By integrating the proteomics data with physiological results, we revealed the metabolic patterns of nitrogen metabolism, photosynthesis, energy supply, as well as chloroplast protein synthesis, import and processing in various leaf regions at different development stages. Additionally, chloroplast-localized proteoforms involved in nitrogen metabolism, photosynthesis and protein processing implied that post-translational modifications were crucial for leaf color regulation. These results provide new clues toward understanding the mechanisms of leaf color regulation in variegated leaves. PMID:27005614

  14. Optimization of three-dimensional imaging on in vitro produced porcine blastocysts and chimeras for stem cell testing

    DEFF Research Database (Denmark)

    Secher, Jan Ole Bertelsen; Freude, Kristine; Li, Rong;

    2015-01-01

    is relevant for testing of presumed pluripotent stem cells. The gold standard for pluripotent stem cells is to test if the cells are capable of contributing to germline chimeras. Differential staining can be used to evaluate the possibility of chimeric contribution; if the cells are located in the...

  15. Chronic graft-versus-host disease in the rat radiation chimera. III. Immunology and immunopathology in rapidly induced models

    International Nuclear Information System (INIS)

    Although chronic graft-versus-host disease (GVHD) frequently develops in the long-term rat radiation chimera, we present three additional models in which a histologically similar disease is rapidly induced. These include adoptive transfer of spleen and bone marrow from rats with spontaneous chronic GVHD into lethally irradiated rats of the primary host strain; sublethal irradiation of stable chimeras followed by a booster transplant; and transfer of spleen cells of chimeras recovering from acute GVHD into second-party (primary recipient strain) or third-party hosts. Some immunopathologic and immune abnormalities associated with spontaneous chronic GVHD were not observed in one or more of the induced models. Thus, IgM deposition in the skin, antinuclear antibodies, and vasculitis appear to be paraphenomena. On the other hand, lymphoid hypocellularity of the thymic medulla, immaturity of splenic follicles, and nonspecific suppressor cells were consistently present in the long term chimeras, and in all models. These abnormalities therefore may be pathogenetically important, or closely related to the development of chronic GVHD

  16. Thymectomized, irradiated, and bone marrow-reconstituted chimeras have normal cytolytic T lymphocyte precursors but a defect in lymphokine production

    International Nuclear Information System (INIS)

    A model system has been developed to study extrathymic T cell differentiation; mice have been thymectomized, lethally irradiated, and reconstituted with bone marrow cells depleted of Thy-1+ cells. After 8 wk, the spleen cells of these athymic, bone marrow-reconstituted chimeras contain Thy-1+ precytolytic T lymphocytes (CTL) that are able to respond to antigen only if supernatant from Con A-activated T cells is added to culture. The phenotype of these pre-CTL is similar to that of thymocytes, suggesting that they may be immature T cells. Initial evaluation of the CTL repertoire of these athymic mice demonstrated that the CTL generated to trinitrophenyl-modified syngeneic cells are H-2-restricted, and that the CTL generated to alloantigens have many of the cross-reactivities observed in normal mice but not in nude mice. In this report, the authors demonstrate a helper T cell defect in these thymectomized chimeras. These chimeras lack an Ly-1+ helper cell required for thymocytes to differentiate to CTL. Further studies revealed that when spleen cells from these thymectomized chimeras were stimulated with Con A, they produced normal levels of interleukin 2. However, these splenocytes were defective in the production of another factor needed for CTL differentiation

  17. Generating Porcine Chimeras Using Inner Cell Mass Cells and Parthenogenetic Preimplantation Embryos

    Science.gov (United States)

    Nakano, Kazuaki; Watanabe, Masahito; Matsunari, Hitomi; Matsuda, Taisuke; Honda, Kasumi; Maehara, Miki; Kanai, Takahiro; Hayashida, Gota; Kobayashi, Mirina; Kuramoto, Momoko; Arai, Yoshikazu; Umeyama, Kazuhiro; Fujishiro, Shuh-hei; Mizukami, Yoshihisa; Nagaya, Masaki; Hanazono, Yutaka; Nagashima, Hiroshi

    2013-01-01

    Background The development and validation of stem cell therapies using induced pluripotent stem (iPS) cells can be optimized through translational research using pigs as large animal models, because pigs have the closest characteristics to humans among non-primate animals. As the recent investigations have been heading for establishment of the human iPS cells with naïve type characteristics, it is an indispensable challenge to develop naïve type porcine iPS cells. The pluripotency of the porcine iPS cells can be evaluated using their abilities to form chimeras. Here, we describe a simple aggregation method using parthenogenetic host embryos that offers a reliable and effective means of determining the chimera formation ability of pluripotent porcine cells. Methodology/Significant Principal Findings In this study, we show that a high yield of chimeric blastocysts can be achieved by aggregating the inner cell mass (ICM) from porcine blastocysts with parthenogenetic porcine embryos. ICMs cultured with morulae or 4–8 cell-stage parthenogenetic embryos derived from in vitro-matured (IVM) oocytes can aggregate to form chimeric blastocysts that can develop into chimeric fetuses after transfer. The rate of production of chimeric blastocysts after aggregation with host morulae (20/24, 83.3%) was similar to that after the injection of ICMs into morulae (24/29, 82.8%). We also found that 4–8 cell-stage embryos could be used; chimeric blastocysts were produced with a similar efficiency (17/26, 65.4%). After transfer into recipients, these blastocysts yielded chimeric fetuses at frequencies of 36.0% and 13.6%, respectively. Conclusion/Significance Our findings indicate that the aggregation method using parthenogenetic morulae or 4–8 cell-stage embryos offers a highly reproducible approach for producing chimeric fetuses from porcine pluripotent cells. This method provides a practical and highly accurate system for evaluating pluripotency of undifferentiated cells, such

  18. THE KEY TO THE TREASURE IS THE TREASURE: BARTH’S METAFICTION IN CHIMERA

    Directory of Open Access Journals (Sweden)

    Katarina Drzajic

    2014-11-01

    Full Text Available John Barth, one of the most prominent postmodern authors, is famous for his creative literary games: while his favorite tool, metafiction, is at times hard to comprehend, he is almost always both the writer and a character of his stories. “Everyone is necessarily the hero of his own life story,” he said, thus confirming the quite loose difference between reality and fiction in post-modernism. Bearing in mind that the story within a story is a common characteristic of his work, in this paper we shall analyze the most interesting points at which we encounter this phenomenon an d discover what actually represents the treasure in one of his most perplexing, yet incredibly captivating novels, Chimera.

  19. Two- and three-dimensional simulations of core-collapse supernovae with CHIMERA

    CERN Document Server

    Lentz, Eric J; Harris, J Austin; Chertkow, Merek Austin; Hix, W Raphael; Mezzacappa, Anthony; Messer, O E Bronson; Bondin, John M; Marronetti, Pedro; Mauney, Christopher M; Yakunin, Konstantin N

    2013-01-01

    Ascertaining the core-collapse supernova mechanism is a complex, and yet unsolved, problem dependent on the interaction of general relativity, hydrodynamics, neutrino transport, neutrino-matter interactions, and nuclear equations of state and reaction kinetics. Ab initio modeling of core-collapse supernovae and their nucleosynthetic outcomes requires care in the coupling and approximations of the physical components. We have built our multi-physics CHIMERA code for supernova modeling in 1-, 2-, and 3-D, using ray-by-ray neutrino transport, approximate general relativity, and detailed neutrino and nuclear physics. We discuss some early results from our current series of exploding 2D simulations and our work to perform computationally tractable simulations in 3D using the "Yin-Yang" grid.

  20. Approximate Waveforms for Extreme-Mass-Ratio Inspirals: The Chimera Scheme

    CERN Document Server

    Sopuerta, Carlos F

    2012-01-01

    We describe a new kludge scheme to model the dynamics of generic extreme-mass-ratio inspirals (EMRIs; stellar compact objects spiraling into a spinning supermassive black hole) and their gravitational-wave emission. The Chimera scheme is a hybrid method that combines tools from different approximation techniques in General Relativity: (i) A multipolar, post-Minkowskian expansion for the far-zone metric perturbation (the gravitational waveforms) and for the local prescription of the self-force; (ii) a post-Newtonian expansion for the computation of the multipole moments in terms of the trajectories; and (iii) a BH perturbation theory expansion when treating the trajectories as a sequence of self-adjusting Kerr geodesics. The EMRI trajectory is made out of Kerr geodesic fragments joined via the method of osculating elements as dictated by the multipolar post-Minkowskian radiation-reaction prescription. We implemented the proper coordinate mapping between Boyer-Lindquist coordinates, associated with the Kerr geo...

  1. Chimera distribution amplitudes for the pion and the longitudinally polarized ρ-meson

    Science.gov (United States)

    Stefanis, N. G.; Pimikov, A. V.

    2016-01-01

    Using QCD sum rules with nonlocal condensates, we show that the distribution amplitude of the longitudinally polarized ρ-meson may have a shorttailed platykurtic profile in close analogy to our recently proposed platykurtic distribution amplitude for the pion. Such a chimera distribution de facto amalgamates the broad unimodal profile of the distribution amplitude, obtained with a Dyson-Schwinger equations-based computational scheme, with the suppressed tails characterizing the bimodal distribution amplitudes derived from QCD sum rules with nonlocal condensates. We argue that pattern formation, emerging from the collective synchronization of coupled oscillators, can provide a single theoretical scaffolding to study unimodal and bimodal distribution amplitudes of light mesons without recourse to particular computational schemes and the reasons for them.

  2. Development of a large scale Chimera grid system for the Space Shuttle Launch Vehicle

    Science.gov (United States)

    Pearce, Daniel G.; Stanley, Scott A.; Martin, Fred W., Jr.; Gomez, Ray J.; Le Beau, Gerald J.; Buning, Pieter G.; Chan, William M.; Chiu, Ing-Tsau; Wulf, Armin; Akdag, Vedat

    1993-01-01

    The application of CFD techniques to large problems has dictated the need for large team efforts. This paper offers an opportunity to examine the motivations, goals, needs, problems, as well as the methods, tools, and constraints that defined NASA's development of a 111 grid/16 million point grid system model for the Space Shuttle Launch Vehicle. The Chimera approach used for domain decomposition encouraged separation of the complex geometry into several major components each of which was modeled by an autonomous team. ICEM-CFD, a CAD based grid generation package, simplified the geometry and grid topology definition by provoding mature CAD tools and patch independent meshing. The resulting grid system has, on average, a four inch resolution along the surface.

  3. Mechanisms of Core-Collapse Supernovae & Simulation Results from the CHIMERA Code

    CERN Document Server

    Bruenn, S W; Hix, W R; Blondin, J M; Marronetti, P; Messer, O E B; Dirk, C J; Yoshida, S

    2010-01-01

    Unraveling the mechanism for core-collapse supernova explosions is an outstanding computational challenge and the problem remains essentially unsolved despite more than four decades of effort. However, much progress in realistic modeling has occurred recently through the availability of multi-teraflop machines and the increasing sophistication of supernova codes. These improvements have led to some key insights which may clarify the picture in the not too distant future. Here we briefly review the current status of the three explosion mechanisms (acoustic, MHD, and neutrino heating) that are currently under active investigation, concentrating on the neutrino heating mechanism as the one most likely responsible for producing explosions from progenitors in the mass range ~10 to ~25 solar masses. We then briefly describe the CHIMERA code, a supernova code we have developed to simulate core-collapse supernovae in 1, 2, and 3 spatial dimensions. We finally describe the results of an ongoing suite of 2D simulations...

  4. Novel type of chimera spiral waves arising from decoupling of a diffusible component

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Xiaodong; Yang, Tao; Liu, Yang; Zhao, Yuemin; Gao, Qingyu, E-mail: epstein@brandeis.edu, E-mail: gaoqy@cumt.edu.cn [College of Chemical Engineering, China University of Mining and Technology, Xuzhou 221008 (China); Epstein, Irving R., E-mail: epstein@brandeis.edu, E-mail: gaoqy@cumt.edu.cn [Department of Chemistry and Volen Center for Complex Systems, MS 015, Brandeis University, Waltham, Massachusetts 02454-9110 (United States)

    2014-07-14

    Spiral waves composed of coherent traveling waves surrounding a core containing stochastically distributed stationary areas are found in numerical simulations of a three-variable reaction-diffusion system with one diffusible species. In the spiral core, diffusion of this component (w) mediates transitions between dynamic states of the subsystem formed by the other two components, whose dynamics is more rapid than that of w. Diffusive coupling between adjacent sites can be “on” or “off” depending on the subsystem state. The incoherent structures in the spiral core are produced by this decoupling of the slow diffusive component from the fast non-diffusing subsystem. The phase diagram reveals that the region of incoherent behavior in chimera spirals grows drastically, leading to modulation and breakup of the spirals, in the transition zones between 1{sup n-1} and 1{sup n} local mixed-mode oscillations.

  5. Two- and three-dimensional simulations of core-collapse supernovae with CHIMERA

    Energy Technology Data Exchange (ETDEWEB)

    Lentz, Eric J [ORNL; Bruenn, S. W. [Florida Atlantic University, Boca Raton; Harris, James A [ORNL; Chertkow, Merek A [ORNL; Hix, William Raphael [ORNL; Mezzacappa, Anthony [ORNL; Messer, Bronson [ORNL; Blondin, J. M. [North Carolina State University; Marronetti, Pedro [Florida Atlantic University, Boca Raton; Mauney, Christopher M [ORNL; Yakunin, Konstantin [Florida Atlantic University, Boca Raton

    2012-01-01

    Ascertaining the core-collapse supernova mechanism is a complex, and yet unsolved, problem dependent on the interaction of general relativity, hydrodynamics, neutrino transport, neutrino-matter interactions, and nuclear equations of state and reaction kinetics. Ab initio modeling of core-collapse supernovae and their nucleosynthetic outcomes requires care in the coupling and approximations of the physical components. We have built our multi-physics CHIMERA code for supernova modeling in 1-, 2-, and 3-D, using ray-by-ray neutrino transport, approximate general relativity, and detailed neutrino and nuclear physics. We discuss some early results from our current series of exploding 2D simulations and our work to perform computationally tractable simulations in 3D using the ``Yin--Yang'' grid.

  6. 2D and 3D Core-Collapse Supernovae Simulation Results Obtained with the CHIMERA Code

    CERN Document Server

    Bruenn, S W; Hix, W R; Blondin, J M; Marronetti, P; Messer, O E B; Dirk, C J; Yoshida, S

    2010-01-01

    Much progress in realistic modeling of core-collapse supernovae has occurred recently through the availability of multi-teraflop machines and the increasing sophistication of supernova codes. These improvements are enabling simulations with enough realism that the explosion mechanism, long a mystery, may soon be delineated. We briefly describe the CHIMERA code, a supernova code we have developed to simulate core-collapse supernovae in 1, 2, and 3 spatial dimensions. We then describe the results of an ongoing suite of 2D simulations initiated from a 12, 15, 20, and 25 solar mass progenitor. These have all exhibited explosions and are currently in the expanding phase with the shock at between 5,000 and 20,000 km. We also briefly describe an ongoing simulation in 3 spatial dimensions initiated from the 15 solar mass progenitor.

  7. The determination of lymphoid cell chimerism using peripheral blood lymphocytes from murine bone marrow chimeras

    International Nuclear Information System (INIS)

    A simple, rapid and accurate method was devised for determining lymphoid cell chimerism in bone marrow-reconstituted mice. Chimeras were produced by reconstituting lethally irradiated mice with semi-allogeneic bone marrow cells. Lymphocytes from the peripheral blood of individual chimeric mice were purified by sedimentation in dextran solution and differential flotation in Ficoll-Hypaque gradients. From 250-500 μl of blood, 1-7 x 105 cells were routinely obtained. The extent of chimerism was determined serologically by using peripheral blood lymphocytes as target cells in a dye exclusion microcytotoxicity assay. Using this new technique, approximately 80% of the reconstituted mice were found to be repopulated with lymphocytes of the donor type. (Auth.)

  8. CHIMERA II - A real-time multiprocessing environment for sensor-based robot control

    Science.gov (United States)

    Stewart, David B.; Schmitz, Donald E.; Khosla, Pradeep K.

    1989-01-01

    A multiprocessing environment for a wide variety of sensor-based robot system, providing the flexibility, performance, and UNIX-compatible interface needed for fast development of real-time code is addressed. The requirements imposed on the design of a programming environment for sensor-based robotic control is outlined. The details of the current hardware configuration are presented, along with the details of the CHIMERA II software. Emphasis is placed on the kernel, low-level interboard communication, user interface, extended file system, user-definable and dynamically selectable real-time schedulers, remote process synchronization, and generalized interprocess communication. A possible implementation of a hierarchical control model, the NASA/NBS standard reference model for telerobot control system is demonstrated.

  9. Chimera distribution amplitudes for the pion and the longitudinally polarized $\\rho$-meson

    CERN Document Server

    Stefanis, N G

    2016-01-01

    Using QCD sum rules with nonlocal condensates, we show that the distribution amplitude of the longitudinally polarized $\\rho$-meson may have a shorttailed platykurtic profile in close analogy to our recently proposed platykurtic distribution amplitude for the pion. Such a chimera distribution de facto amalgamates the broad unimodal profile of the distribution amplitude, obtained with a Dyson-Schwinger equations-based computational scheme, with the suppressed tails characterizing the bimodal distribution amplitudes derived from QCD sum rules with nonlocal condensates. We argue that pattern formation, emerging from the collective synchronization of coupled oscillators, can provide a single theoretical scaffolding to study unimodal and bimodal distribution amplitudes of light mesons without recourse to particular computational schemes and the reasons for them.

  10. Monsters, dreams and madness: Commentary on 'The arms of the chimeras'.

    Science.gov (United States)

    Reis, Bruce

    2016-04-01

    Considering Freudian and Post-Freudian approaches to the intersubjective Beatrice Ithier puts the work of Michel de M'Uzan and Thomas Ogden in comparison. To this comparison I add a consideration of the work of Christopher Bollas. The highly creative clinical approaches these three theorists take is shown to be informed by their elaborations of the Freudian notion of unconscious communication and by new approaches to the issue of identity. Attention is paid to differentiating traumatic from fanciful chimeras; and to the experience of the analyst undergoing the sorts of transformations requisite to entering this psychic space marked by fluid exchanges of being and becoming, wherein analyst becomes patient, new subjects are created through shared dreams, and through which monsters appear.

  11. Monsters, dreams and madness: Commentary on 'The arms of the chimeras'.

    Science.gov (United States)

    Reis, Bruce

    2016-04-01

    Considering Freudian and Post-Freudian approaches to the intersubjective Beatrice Ithier puts the work of Michel de M'Uzan and Thomas Ogden in comparison. To this comparison I add a consideration of the work of Christopher Bollas. The highly creative clinical approaches these three theorists take is shown to be informed by their elaborations of the Freudian notion of unconscious communication and by new approaches to the issue of identity. Attention is paid to differentiating traumatic from fanciful chimeras; and to the experience of the analyst undergoing the sorts of transformations requisite to entering this psychic space marked by fluid exchanges of being and becoming, wherein analyst becomes patient, new subjects are created through shared dreams, and through which monsters appear. PMID:26996388

  12. TRAPS, CHIMERAS AND PATHWAYS: THREE APPROACHES OF ART IN CONTEMPORARY ANTHROPOLOGY

    Directory of Open Access Journals (Sweden)

    André Demarchi

    2009-12-01

    Full Text Available Based upon the concepts of traps, chimera and pathways proposed by Alfred Gell, Carlo Severi and Els Lagrou respectively, this bibliographic essay presents the characteristics, similarities and specificities of three approaches on art in contemporary anthropology. The work focuses on the ruptures created by these approaches, concerning the symbolic analysis that has long dominated the anthropological art studies. Breaking away from the conception of art as a symbolic language, the studies we analyzed emphasized, in different ways, the cognitive action of art in native contexts, privileging categories such as agency, efficacy, counter-intuitiveness, and presentification. In the conclusion, we demonstrate how these categories are applied to Amerindian Art through the work of Els Lagrou on Cashinahua Art.

  13. Proposal for a new detector for small-p{sub t} physics

    Energy Technology Data Exchange (ETDEWEB)

    Da Via`, C.; Mondardini, M.R.; Orear, J. [Cornell Univ., Ithaca, NY (United States); DeSalvo, R. [CERN/LAA, Geneva (Switzerland)

    1992-12-31

    Elastic pp (or pp{sup {minus}}) scattering at microradian angles provides an absolute luminosity calibration as well as a measurement of the total pp (or pp{sup {minus}}) cross section, the slope of the elastic scattering cross section versus t (the square of the momentum transfer) and the ratio of real to imaginary scattering amplitudes. A detector is proposed which, given favorable beam design, can measure small angle elastic scattering into the Coulomb region, large angle elastic scattering, single diffraction dissociation and other small angle processes which would be missed by a typical 4{pi} detector. The proposed detector is made out of a scintillating fibers bundle. Light from these fibers is transported via fiber optics and read out with 2 Image Intensifiers and a Charge-Coupled Device (CCD). The active part of the detector is placed directly in the vacuum of the beam pipe and is moved by a high precision mechanism. Two couples of such detectors (symmetric in the horizontal or vertical plane) would be positioned along the beam pipe at symmetric positions respect to the interaction point.

  14. Adaptive differentiation of H-2- and Igh-restricted B lymphocyte in tetraparental bone marrow chimera

    International Nuclear Information System (INIS)

    Immunization of BALB/c mice with MOPC-104E myeloma protein induced idiotype-specific enhancing B cells that acted on anti-dextran antibody producing B cells. The enhancing cells have the surface phenotype of B cells. With the use of several H-2 or Igh congenic mice, it was found that the cooperation among B cells was controlled by both the major histocompatibility complex (MHC) and Igh. The capability to generate enhancing B cell activity was analyzed by using tetraparental bone marrow chimeras. (C57BL/6 X BALB/c)F1 mice, for example, were lethally irradiated and were reconstituted with C57BL/6 and BALB/c bone marrow cells. Nine to 12 wk after the reconstitution, the chimeras were immunized with the myeloma protein and were tested for their enhancing B cell activity. After the removal of C57BL/6 origin cells by treatment with anti-H-2b + complement, residual cells exhibited enhancing B cell activity on BALB.B, as well as BALB/c antidextran antibody response. This indicates that the generation of H-2-restricted, idiotype-specific enhancing B cell activity differentiated adaptively so as to recognize foreign MHC as self under chimeric conditions. On the other hand, splenic B cells treated with anti-H-2d + complement did not enhance the responses of BALB/c or BALB.B. Even in a chimeric environment, the B cells of C57BL/6 origin could not obtain the ability to generate enhancing B cell activity upon immunization of the idiotype. The results described here, taken in conjunction with our previous studies, suggest that the Ig heavy chain gene(s) predominantly control the Igh restriction properties of enhancing B cells, and the capability of MHC recognition by B cells is selected under chimeric conditions

  15. Chimera States in Earthquake Sequencing: Preliminary Results from Global Seismic Records

    Science.gov (United States)

    Vasudevan, Kris; Cavers, Michael S.

    2015-04-01

    Earthquakes are occurrences resulting from significant stress-field alterations among faults. In general, spatio-temporal stress-field fluctuations are complex. They evolve continuously. We propose that they are akin to the dynamics of the collective behaviour of weakly-coupled non-linear "oscillators". Here, an oscillation refers to a fault-system reaching a threshold value for an earthquake occurrence at a given time and then, falling into a quiescence period during which the stress-build-up reoccurs in a prescribed manner. The duration of the quiescence period varies from one fault system to the other, depending on the forces behind it. Since mapping of global stress-field fluctuations in real time at all scales is an impossible task, we consider an earthquake zone as a proxy for a collection of weakly-coupled oscillators the dynamics of which would befit the ubiquitous Kuramoto model. In the present work, we apply the Kuramoto model to understand the non-linear dynamics on a directed graph of a sequence of global earthquakes. For directed graphs with certain properties, the Kuramoto model yields either synchronization or asynchronization. Inclusion of non-local effects evokes the occurrence of chimera states or the co-existence of synchronous and asynchronous behaviour of oscillators. In this presentation, we show how we build the model for directed graphs derived from global seismicity data. Then, we present conditions under which chimera states could occur and subsequently, point out the role of Kuramoto model in understanding the evolution of synchronous and asynchronous regions. We interpret our results with the spectral properties of directed graphs.

  16. Earthquake sequencing: Chimera states with Kuramoto model dynamics on directed graphs

    Directory of Open Access Journals (Sweden)

    K. Vasudevan

    2015-02-01

    Full Text Available Earthquake sequencing studies allow us to investigate empirical relationships among spatio-temporal parameters describing the complexity of earthquake properties. We have recently studied the relevance of Markov chain models to draw information from global earthquake catalogues. In these studies, we considered directed graphs as graph theoretic representations of the Markov chain model, and analyzed their properties. Here, we look at earthquake sequencing itself as a directed graph. In general, earthquakes are occurrences resulting from significant stress-interactions among faults. As a result, stress-field fluctuations evolve continuously. We propose that they are akin to the dynamics of the collective behaviour of weakly-coupled non-linear oscillators. Since mapping of global stress-field fluctuations in real time at all scales is an impossible task, we consider an earthquake zone as a proxy for a collection of weakly-coupled oscillators, the dynamics of which would be appropriate for the ubiquitous Kuramoto model. In the present work, we apply the Kuramoto model to the non-linear dynamics on a directed graph of a sequence of earthquakes. For directed graphs with certain properties, the Kuramoto model yields synchronization, and inclusion of non-local effects evokes the occurrence of chimera states or the co-existence of synchronous and asynchronous behaviour of oscillators. In this paper, we show how we build the directed graphs derived from global seismicity data. Then, we present conditions under which chimera states could occur and subsequently, point out the role of Kuramoto model in understanding the evolution of synchronous and asynchronous regions.

  17. Cross-reactivity of hypervariable region 1 chimera of hepatitis C virus

    Institute of Scientific and Technical Information of China (English)

    Bing-Shui Xiu; Shi-Gan Ling; Xiao-Guo Song; He-Qiu Zhang; Kun Chen; Cui-Xia Zhu

    2003-01-01

    AIM: To analyze the amino acid sequences of hypervariable region 1 (HVR1) of HCV isolates in China and to construct a combinatorial chimeric HVR1 protein having a very broad high cross-reactivity. METHODS: All of the published HVR1 sequences from China were collected and processed with a computer program.Several representative HVR1's sequences were formulated based on a consensus profile and homology within certain subdivision. A few reported HVR1 mimotope sequences were also included for a broader representation. All of them were cloned and expressed in E.coli. The cross-reactivity of the purified recombinant HVR1 antigens was tested by ELISA with a panel of sera from HCV infected patients in China.Some of them were further ligated together to form a combinatorial HVR1 chimera. RESULTS: Altogether 12 HVR1s were selected and expressed in E. coli and purified to homogeneity. All of these purified antigens showed some cross-reactivity with sera in a 27 HCV positive panel. Recombinant HVR1s of No. 1, 2, 4, and 8# showing broad cross-reactivities and complementarity with each other, were selected for the ligation elements. The chimera containing these 4 HVR1s was highly expressed in E. coli. The purified chimeric antigen could react not only with all the HCV antibody positive sera in the panel but also with 90/91 sera of HCV -infected patients. CONCLUSION: The chimeric antigen was shown to have a broad cross-reactivity. It may be helpful for solving the problem caused by high variability of HCV, and in the efforts for a novel vaccine against the virus.

  18. Pharmacological characterisation of α6β4* nicotinic acetylcholine receptors assembled from three different α6/α3 subunit chimeras in tsA201 cells

    DEFF Research Database (Denmark)

    Jensen, Anne Bjørnskov; Hoestgaard-Jensen, Kirsten; Jensen, Anders A.

    2014-01-01

    by their inefficient functional expression in vitro. In the present study we have characterized and compared the pharmacological properties displayed by α6β4 and α6β4β3 nicotinic acetylcholine receptors assembled in tsA201 cells from the classical α6/α3 chimera (C1) and two novel α6/α3 chimeras (C6F223L and C16F223L...

  19. GADRAS Detector Response Function.

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Dean J.; Harding, Lee; Thoreson, Gregory G; Horne, Steven M.

    2014-11-01

    The Gamma Detector Response and Analysis Software (GADRAS) applies a Detector Response Function (DRF) to compute the output of gamma-ray and neutron detectors when they are exposed to radiation sources. The DRF is fundamental to the ability to perform forward calculations (i.e., computation of the response of a detector to a known source), as well as the ability to analyze spectra to deduce the types and quantities of radioactive material to which the detectors are exposed. This document describes how gamma-ray spectra are computed and the significance of response function parameters that define characteristics of particular detectors.

  20. The MINOS Detectors

    CERN Document Server

    Grashorn, A H E W

    2005-01-01

    The Main Injector Neutrino Oscillation Search (MINOS) experiment's primary goal is the precision measurement of the neutrino oscillation parameters in the atmospheric neutrino sector. This long-baseline experiment uses Fermilab's NuMI beam, measured with a Near Detector at Fermilab, and again 735 km later using a Far Detector in the Soudan Mine Underground Lab in northern Minnesota. The detectors are magnetized iron/scintillator calorimeters. The Far Detector has been operational for cosmic ray and atmospheric neutrino data from July of 2003, the Near Detector from September 2004, and the NuMI beam started in early 2005. This poster presents details of the two detectors.

  1. The TALE Tower Detector

    Science.gov (United States)

    Bergman, D. R.

    The TA Low Energy Extension will include a Tower FluorescenceDetector. Extensive air showers at the lowest usful energies for fluorescence detectors will in general be close to the detector. This requires viewing all elevation angles to be able to reconstruct showers. The TALE Tower Detector, operating in conjunction with other TALE detectors will view elevation angles up to above 70 degrees, with an azimuthal coverage of about 90 degrees. Results from a prototype mirror operated in conjunction with the HiRes detector will also be presented.

  2. Interspecies chimera between primate embryonic stem cells and mouse embryos: Monkey ESCs engraft into mouse embryos, but not post-implantation fetuses

    Science.gov (United States)

    Simerly, Calvin; McFarland, Dave; Castro, Carlos; Lin, Chih-Cheng; Redinger, Carrie; Jacoby, Ethan; Mich-Basso, Jocelyn; Orwig, Kyle; Mills, Parker; Ahrens, Eric; Navara, Chris; Schatten, Gerald

    2016-01-01

    Unequivocal evidence for pluripotency in which embryonic stem cells contribute to chimeric offspring has yet to be demonstrated in human or nonhuman primates (NHPs). Here, rhesus and baboons ESCs were investigated in interspecific mouse chimera generated by aggregation or blastocyst injection. Aggregation chimera produced mouse blastocysts with GFP-nhpESCs at the inner cell mass (ICM), and embryo transfers (ETs) generated dimly-fluorescencing abnormal fetuses. Direct injection of GFP-nhpESCs into blastocysts produced normal non-GFP-fluorescencing fetuses. Injected chimera showed >70% loss of GFP-nhpESCs after 21 h culture. Outgrowths of all chimeric blastocysts established distinct but separate mouse- and NHP-ESC colonies. Extensive endogenous autofluorescence compromised anti-GFP detection and PCR analysis did not detect nhpESCs in fetuses. NhpESCs localize to the ICM in chimera and generate pregnancies. Because primate ESCs do not engraft post-implantation, and also because endogenous autofluorescence results in misleading positive signals, interspecific chimera assays for pluripotency with primate stem cells is unreliable with the currently available ESCs. Testing primate ESCs reprogrammed into even more naïve states in these inter-specific chimera assays will be an important future endeavor. PMID:21543277

  3. Restricted antibody formation to sheep erythrocytes of allogeneic bone marrow chimeras histoincompatible at the K end of the H-2 complex

    International Nuclear Information System (INIS)

    Employing a new method for allogeneic bone marrow transplantation, irradiation chimeras constructed from various combinations of marrow cells from B10 H-2 recombinant mice and AKR recipients were prepared. Though these chimeras had well-developed populations of T and B cells, they showed strikingly different patterns of responses in the primary antibody formation to sheep erythrocytes (SRBC), a T dependent antigen. These are (a) AKR mice treated with C57BL/10 cells, [B10 leads to AKR] fully H-2 incompatible, and AKR mice treated with B10.A (5R) cells, [5R leads to AKR] I-J,E compatible chimeras that were almost completely unresponsive to SRBC; (b) AKR mice treated with B10.BR cells [BR leads to AKR] fully H-2 compatible, and AKR mice treated with B10 AKM cells, [AKM leads to AKR] chimeras where donor and recipient differed only at H-2D, showed the same number of plaque-forming cells (PFC) as B10 control mice; (c) AKR mice treated with B10.A cells, [B10 leads to AKR] chimeras, where donor and recipient were matched at H-2K-I-E region, showed about one-half the number of PFC as the control mice. From these results we conclude that in allogeneic bone marrow chimeras primary antibody response to T-dependent antigen, such as SRBC, is generated when at least the K end of the H-2 complex is compatible between donor and recipient

  4. Functional clonal deletion versus suppressor cell-induced transplantation tolerance in chimeras prepared with a short course of total-lymphoid irradiation

    International Nuclear Information System (INIS)

    Allogeneic bone marrow (BM) chimeras induced by infusion of BM cells into recipients conditioned with total lymphoid irradiation (TLI) were shown to develop humoral and cell-mediated tolerance to host and donor-type alloantigens by a number of in vitro and in vivo assays. Spleen cells of tolerant chimeras exhibited suppressive activity of mixed lymphocyte reaction (MLR). MLR suppression was not abrogated by depletion of Lyt-2 cells, and neither could Lyt-2-positive cells sorted from the spleens of tolerant chimeras suppress MLR or attenuate graft-versus-host reactivity in vivo. Likewise, specifically unresponsive spleen cells obtained from chimeras could not be induced to respond in MLR against tolerizing host-type cells following depletion of Lyt-2 or passage through a nylon-wool column. Tolerance of chimera spleen cells to host alloantigens, best documented by permanent survival of donor-type skin allografts, could be adoptively transferred into syngeneic recipients treated by heavy irradiation but not into untreated or mildly irradiated recipients. Adoptive transfer of tolerance seemed to be associated with experimental conditions favoring engraftment of tolerant cells rather than suppression of host reactivity. We speculate that although host and/or donor-derived suppressor cells may be operating in reducing the pool of specific alloreactive clones by blocking cell proliferation in response to allogeneic challenge, the final outcome in tolerant chimeras is actual or functional deletion of alloreactive clones

  5. Drift Chambers detectors; Detectores de deriva

    Energy Technology Data Exchange (ETDEWEB)

    Duran, I.; Martinez laso, L.

    1989-07-01

    We present here a review of High Energy Physics detectors based on drift chambers. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysed, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author) 115 refs.

  6. Tin Can Radiation Detector.

    Science.gov (United States)

    Crull, John L.

    1986-01-01

    Provides instructions for making tin can radiation detectors from empty aluminum cans, aluminum foil, clear plastic, copper wire, silica gel, and fine, unwaxed dental floss put together with tape or glue. Also provides suggestions for activities using the detectors. (JN)

  7. Forward tracking detectors

    Indian Academy of Sciences (India)

    Klaus Mönig

    2007-11-01

    Forward tracking is an essential part of a detector at the international linear collider (ILC). The requirements for forward tracking are explained and the proposed solutions in the detector concepts are shown.

  8. Early dominance of irradiated host cells in the responder profiles of thymocytes from P → F1 radiation chimeras

    International Nuclear Information System (INIS)

    The number of cells in the thymus of radiation (1000 rad) chimeras increases approximately 10-fold between 7 and 14 days after reconstitution with bone marrow. At least 50% of the cells in thymus on day 14 are of host origin and respond to virus presented in the context of both H-2/sup k/ and H-2/sup b/ when primed in irradiated, virus-infected (b x k)F1 recipients. Strong CTL responses can be generated from thymocytes of donor origin on day 21. All evidence of a significant host thymocyte component has disappeared by day 28. The responsiveness of 14-day thymocytes is not abrogated by pretreatment of the mice used to make the chimeras with anti-thymocyte serum or by using doses of irradiation as high as 1200 rads to eliminate host components

  9. Dominance and persistence of donor marrow in long-lived allogeneic radiation chimeras obtained with unmanipulated bone marrow

    International Nuclear Information System (INIS)

    Allogeneic, H-2-incompatible irradiation chimeras (H-2sup(d) → H-2sup(b)) constructed with normal, unmanipulated bone marrow and with marrow-derived factors live long and do not manifest a GvH disease. Their response to primary immunization is deficient but their alloreactivity is normal. This chimeric allotolerance cannot be passively transferred from chimeric donors to normal irradiated recipients. Passive transfer of both donor- or recipient-type immuno-competent T-cells into the chimeric mice does not lead to syngeneic reconstitution, rejection of the engrafted marrow or GvH disease, and the mice maintain permanently their chimerism. This new model demonstrates that chimerism is not eradicable in long-lived chimeras reconstituted with unmanipulated bone marrow, and that the bone marrow itself plays a dominant role in maintenance of chimerism. (Auth.)

  10. Stromal cells in long-term murine bone marrow culture: FACS studies and origin of stromal cells in radiation chimeras

    International Nuclear Information System (INIS)

    Adherent layers from hematopoietically active long-term bone marrow cultures (LTBMC), incubated with fluorescent beads, were analyzed for autofluorescence and phagocytic ability, using a fluorescence-activated cell sorter (FACS). Four groups of cells were separated from the adherent layers, including a group of large polygonal fibroblastoid stromal cells. Long-term chimeras were made by lethal irradiation of CBA/Ca (CBA) and C57Bl6/J (B6) mice and repopulation with phosphoglycerate kinase (PGK-1) alloenzyme-congenic bone marrow cells. Hematopoietically active LTBMC were established from such chimeras, and donor and host contributions of FACS-sorted adherent-layer cells were measured. While macrophages and other hematopoietic cells were of donor origin, the fibroblastoid stromal cells were mainly or entirely host derived

  11. Construction of serial deletants and chimeras of multi-kringle containing molecules and primary analysis of their functions

    Institute of Scientific and Technical Information of China (English)

    宫锋; 董春娜; 张咏; 章杨培; 吴祖泽; 贺福初

    1999-01-01

    In comparison of amino acid sequences of 4 kringles of both macrophage stimulating protein (MSP) and hepatocyte growth factor (HGF), consensus motif sequence was determined. According to this consensus sequence, a pair of universal primers were designed. In combination with specific upstream or downstream primer of MSP or HGF respectively, serial fragments containing variant number of kringle (from 1 to 4) can be obtained by once PCR. By ligating the C terminal and N terminal fragments with different combination, serial deletants and chimeras of MSP and HGF were constructed. Sequence analysis showed that the degeneracy for universal primers and the sequences of those constructed deletants and chimeras are desired. Biological assay of these deletants revealed that wild type MSP can inhibit the growth of some tumor cell lines and that kringle 1 of MSP is essential for function as that of HGF.

  12. JADE muon detector

    Energy Technology Data Exchange (ETDEWEB)

    Allison, J.; Armitage, J.C.M.; Baines, J.T.M.; Ball, A.H.; Bamford, G.; Barlow, R.J.; Bowdery, C.K.; Chrin, J.T.M.; Duerdoth, I.P.; Glendinning, I.; Greenshaw, T.; Hassard, J.F.; Hill, P.; King, B.T.; Loebinger, F.K.; Macbeth, A.A.; McCann, H.; Mercer, D.; Mills, H.E.; Murphy, P.G.; Prosper, H.B.; Rowe, P.; Stephens, K.

    1985-08-01

    The JADE muon detector consists of 618 planar drift chambers interspersed between layers of hadron absorber. This paper gives a detailed description of the construction and operation of the detector as a whole and discusses the properties of the drift chambers. The muon detector has been operating successfully at PETRA for five years. (orig.).

  13. Gas filled detectors

    International Nuclear Information System (INIS)

    The main types of gas filled nuclear detectors: ionization chambers, proportional counters, parallel-plate avalanche counters (PPAC) and microstrip detectors are described. New devices are shown. A description of the processes involved in such detectors is also given. (K.A.) 123 refs.; 25 figs.; 3 tabs

  14. 先天性嵌合体的形成与临床%Formation and clinical research of congenital chimera

    Institute of Scientific and Technical Information of China (English)

    王琳凯; 张阮章; 王沙燕

    2014-01-01

    A chimera is produced by the fusion of two or more different zygotes in a single embryo.The chimerism has been rarely reported in humans.It is usually discovered because a discrepancy is observed in blood typing or sex chromosome complement.So far,several types of chimera have been discovered.However,the underlying mechanisms are poorly understood.In this article,the previous literatures which involved chimerism are reviewed,and the types of chimera,formation mechanisms,detected methods,and diagnostic strategies are summarized.We hope it is helpful to the research of chimera.%嵌合体是指同一个体中同时存在两个或多个不同细胞系的现象,在人类中比较罕见,一般是由于观察到血型或者性染色体异常才发现此种现象.目前,已陆续发现了多种类型的嵌合体,对其临床与实验室的研究取得了初步进展,但对于嵌合体的认识,特别是对其形成机制了解得尚不充分.该文中,回顾了以往文献对先天性嵌合体案例的报道及相关研究,并在其基础上总结了嵌合体的类型、形成机制、检测方法及诊断策略,以期进一步促进嵌合体的相关研究.

  15. Evaluation of PCR-generated chimeras, mutations, and heteroduplexes with 16S rRNA gene-based cloning.

    Science.gov (United States)

    Qiu, X; Wu, L; Huang, H; McDonel, P E; Palumbo, A V; Tiedje, J M; Zhou, J

    2001-02-01

    To evaluate PCR-generated artifacts (i.e., chimeras, mutations, and heteroduplexes) with the 16S ribosomal DNA (rDNA)-based cloning approach, a model community of four species was constructed from alpha, beta, and gamma subdivisions of the division Proteobacteria as well as gram-positive bacterium, all of which could be distinguished by HhaI restriction digestion patterns. The overall PCR artifacts were significantly different among the three Taq DNA polymerases examined: 20% for Z-Taq, with the highest processitivity; 15% for LA-Taq, with the highest fidelity and intermediate processitivity; and 7% for the conventionally used DNA polymerase, AmpliTaq. In contrast to the theoretical prediction, the frequency of chimeras for both Z-Taq (8.7%) and LA-Taq (6.2%) was higher than that for AmpliTaq (2.5%). The frequencies of chimeras and of heteroduplexes for Z-Taq were almost three times higher than those of AmpliTaq. The total PCR artifacts increased as PCR cycles and template concentrations increased and decreased as elongation time increased. Generally the frequency of chimeras was lower than that of mutations but higher than that of heteroduplexes. The total PCR artifacts as well as the frequency of heteroduplexes increased as the species diversity increased. PCR artifacts were significantly reduced by using AmpliTaq and fewer PCR cycles (fewer than 20 cycles), and the heteroduplexes could be effectively removed from PCR products prior to cloning by polyacrylamide gel purification or T7 endonuclease I digestion. Based upon these results, an optimal approach is proposed to minimize PCR artifacts in 16S rDNA-based microbial community studies.

  16. Recombinant peptide replicates immunogenicity of synthetic linear peptide chimera for use as pre-erythrocytic stage malaria vaccine

    OpenAIRE

    Silva-Flannery, Luciana M.; Cabrera-Mora, Monica; Jiang, Jianlin; Moreno, Alberto

    2008-01-01

    Synthetic linear peptide chimeras (LPCscys+) show promise as delivery platforms for malaria subunit vaccines. Maximal immune response to LPCscys+ in rodent malaria models depends upon formation of cross-linkages to generate homopolymers, presenting challenges for vaccine production. To replicate the immunogenicity of LPCscys+ using a recombinant approach, we designed a recombinant LPC (rLPC) based on Plasmodium yoelii circumsporozoite protein-specific sequences of 208 amino acids consisting o...

  17. Co-targeting EGFR and survivin with a bivalent aptamer-dual siRNA chimera effectively suppresses prostate cancer.

    Science.gov (United States)

    Liu, Hong Yan; Yu, Xiaolin; Liu, Haitao; Wu, Daqing; She, Jin-Xiong

    2016-01-01

    Current targeted therapies using small kinase inhibitors and antibodies have limited efficacy in treating prostate cancer (PCa), a leading cause of cancer death in American men. We have developed a novel strategy by engineering an RNA-based aptamer-siRNA chimera, in which a bivalent aptamer specifically binds prostate-specific membrane antigen (PSMA) via an antibody-like structure to promote siRNA internalization in PCa cells, and two siRNAs specific to EGFR and survivin are fused between two aptamers. The chimera is able to inhibit EGFR and survivin simultaneously and induce apoptosis effectively in vitro and in vivo. In the C4-2 PCa xenograft model, the treatment with the chimera significantly suppresses tumor growth and angiogenesis. The inhibition of angiogenesis is mediated by an EGFR-HIF1α-VEGF-dependent mechanism. Our results support that the bivalent aptamer-driven delivery of two siRNAs could be a new combination therapeutic strategy to effectively inhibit multiple and conventionally "undruggable" targets. PMID:27456457

  18. Epitope Mapping of Neutralizing Monoclonal Antibodies to Human Interferon-γ Using Human-Bovine Interferon-γ Chimeras

    Science.gov (United States)

    Zuber, Bartek; Rudström, Karin; Ehrnfelt, Cecilia

    2016-01-01

    Our aim was to identify conformational epitopes, recognized by monoclonal antibodies (mAbs) made against human (h) interferon (IFN)-γ. Based on the mAbs' (n = 12) ability to simultaneously bind hIFN-γ in ELISA, 2 epitope clusters with 5 mAbs in each were defined; 2 mAbs recognized unique epitopes. Utilizing the mAbs' lack of reactivity with bovine (b) IFN-γ, epitopes were identified using 7 h/bIFN-γ chimeras where the helical regions (A-F) or the C terminus were substituted with bIFN-γ residues. Chimeras had a N-terminal peptide tag enabling the analysis of mAb recognition of chimeras in ELISA. The 2 mAb clusters mapped to region A and E, respectively; the epitopes of several mAbs also involved additional regions. MAbs in cluster A neutralized, to various degrees, IFN-γ-mediated activation of human cells, in line with the involvement of region A in the IFN-γ receptor interaction. MAbs mapping to region E displayed a stronger neutralizing capacity although this region has not been directly implicated in the receptor interaction. The results corroborate earlier studies and provide a detailed picture of the link between the epitope specificity and neutralizing capacity of mAbs. They further demonstrate the general use of peptide-tagged chimeric proteins as a powerful and straightforward method for efficient mapping of conformational epitopes. PMID:27336613

  19. Epitope Mapping of Neutralizing Monoclonal Antibodies to Human Interferon-γ Using Human-Bovine Interferon-γ Chimeras.

    Science.gov (United States)

    Zuber, Bartek; Rudström, Karin; Ehrnfelt, Cecilia; Ahlborg, Niklas

    2016-09-01

    Our aim was to identify conformational epitopes, recognized by monoclonal antibodies (mAbs) made against human (h) interferon (IFN)-γ. Based on the mAbs' (n = 12) ability to simultaneously bind hIFN-γ in ELISA, 2 epitope clusters with 5 mAbs in each were defined; 2 mAbs recognized unique epitopes. Utilizing the mAbs' lack of reactivity with bovine (b) IFN-γ, epitopes were identified using 7 h/bIFN-γ chimeras where the helical regions (A-F) or the C terminus were substituted with bIFN-γ residues. Chimeras had a N-terminal peptide tag enabling the analysis of mAb recognition of chimeras in ELISA. The 2 mAb clusters mapped to region A and E, respectively; the epitopes of several mAbs also involved additional regions. MAbs in cluster A neutralized, to various degrees, IFN-γ-mediated activation of human cells, in line with the involvement of region A in the IFN-γ receptor interaction. MAbs mapping to region E displayed a stronger neutralizing capacity although this region has not been directly implicated in the receptor interaction. The results corroborate earlier studies and provide a detailed picture of the link between the epitope specificity and neutralizing capacity of mAbs. They further demonstrate the general use of peptide-tagged chimeric proteins as a powerful and straightforward method for efficient mapping of conformational epitopes. PMID:27336613

  20. A Navier-Strokes Chimera Code on the Connection Machine CM-5: Design and Performance

    Science.gov (United States)

    Jespersen, Dennis C.; Levit, Creon; Kwak, Dochan (Technical Monitor)

    1994-01-01

    We have implemented a three-dimensional compressible Navier-Stokes code on the Connection Machine CM-5. The code is set up for implicit time-stepping on single or multiple structured grids. For multiple grids and geometrically complex problems, we follow the 'chimera' approach, where flow data on one zone is interpolated onto another in the region of overlap. We will describe our design philosophy and give some timing results for the current code. A parallel machine like the CM-5 is well-suited for finite-difference methods on structured grids. The regular pattern of connections of a structured mesh maps well onto the architecture of the machine. So the first design choice, finite differences on a structured mesh, is natural. We use centered differences in space, with added artificial dissipation terms. When numerically solving the Navier-Stokes equations, there are liable to be some mesh cells near a solid body that are small in at least one direction. This mesh cell geometry can impose a very severe CFL (Courant-Friedrichs-Lewy) condition on the time step for explicit time-stepping methods. Thus, though explicit time-stepping is well-suited to the architecture of the machine, we have adopted implicit time-stepping. We have further taken the approximate factorization approach. This creates the need to solve large banded linear systems and creates the first possible barrier to an efficient algorithm. To overcome this first possible barrier we have considered two options. The first is just to solve the banded linear systems with data spread over the whole machine, using whatever fast method is available. This option is adequate for solving scalar tridiagonal systems, but for scalar pentadiagonal or block tridiagonal systems it is somewhat slower than desired. The second option is to 'transpose' the flow and geometry variables as part of the time-stepping process: Start with x-lines of data in-processor. Form explicit terms in x, then transpose so y-lines of data are

  1. High-energy detector

    Science.gov (United States)

    Bolotnikov, Aleksey E.; Camarda, Giuseppe; Cui, Yonggang; James, Ralph B.

    2011-11-22

    The preferred embodiments are directed to a high-energy detector that is electrically shielded using an anode, a cathode, and a conducting shield to substantially reduce or eliminate electrically unshielded area. The anode and the cathode are disposed at opposite ends of the detector and the conducting shield substantially surrounds at least a portion of the longitudinal surface of the detector. The conducting shield extends longitudinally to the anode end of the detector and substantially surrounds at least a portion of the detector. Signals read from one or more of the anode, cathode, and conducting shield can be used to determine the number of electrons that are liberated as a result of high-energy particles impinge on the detector. A correction technique can be implemented to correct for liberated electron that become trapped to improve the energy resolution of the high-energy detectors disclosed herein.

  2. Growth of transplantable melanoma and leukaemia and prevention of virus-induced leukaemia in long lived radiation chimeras constructed with unmanipulated bone marrow

    International Nuclear Information System (INIS)

    Haemopoietic radiation chimeras across the H-2 barrier (BALB/c → C57B1/6; H-2sup(d) → H-2sup(b) chimeras and vice versa) have been studied for their capacity to suppress the growth, or to reject, transplantable B16 melanotic melanoma and radiation leukaemia virus-induced, transplantable leukaemia. Also, radiation leukaemia virus (RadLV) obtained from the thymus of leukaemic C57B1/6 mice was injected i.p. into established chimeras (H-2sup(d) → H-2sup(b)). As expected, long lived, graft versus host disease free allogeneic chimeras constructed with intact bone marrow were unable to reject the tumours both when recipients were BALB/c → C57B1/6 or C57B1/6 → BALB/c chimeras. However, inoculation of a large number of immunocompetent cells from normal BALB/c mice into BALB/c → C57B1/6 chimeras failed to promote a rejection of the tumours. On the contrary, the same amount of syngeneic (BALB/c) immunocompetent cells prevented growth of melanoma when transferred into athymic nude BALB/c mice, while the tumour grew unimpaired in untreated athymic nude BALB/c mice. The same type of H-2sup(d) → H-2sup(b) chimeras displayed complete resistance to inoculation of leukaemogenic H-2sup(b) restricted RadLV while all H-2sup(b) → H-2sup(b), syngeneically reconstituted mice developed disseminated leukaemia. (author)

  3. Detector environment and detector response : a survey

    OpenAIRE

    Holmstedt, Göran; Magnusson, Sven Erik; Thomas, Philip H

    1987-01-01

    1. The survey has mainly concentrated on the following items: the false alarm problem, the problem of the fire not being detected due to the fact that pre-fire heating and ventilation dominate flow inside the compartment, a description of detector sensitivity to fire signatures. engineering design methods for the siting of detectors. 2. The statistical as well as practical experience suggests that alarm systems in Sweden, follow international trends regarding rates of false alarms. 3. F...

  4. Aerodynamic study of sounding rocket flows using Chimera and patched multiblock meshes

    Directory of Open Access Journals (Sweden)

    João Alves de Oliveira Neto

    2011-01-01

    Full Text Available Aerodynamic flow simulations over a typical sounding rocket are presented in this paper. The work is inserted in the effort of developing computational tools necessary to simulate aerodynamic flows over configurations of interest for Instituto de Aeronáutica e Espaço of Departamento de Ciência e Tecnologia Aeroespacial. Sounding rocket configurations usually require fairly large fins and, quite frequently, have more than one set of fins. In order to be able to handle such configurations, the present paper presents a novel methodology which combines both Chimera and patched multiblock grids in the discretization of the computational domain. The flows of interest are modeled using the 3-D Euler equations and the work describes the details of discretization procedure, which uses a finite difference approach for structure, body-conforming, multiblock grids. The method is used to calculate the aerodynamics of a sounding rocket vehicle. The results indicate that the present approach can be a powerful aerodynamic analysis and design tool.

  5. Human-animal chimeras: ethical issues about farming chimeric animals bearing human organs.

    Science.gov (United States)

    Bourret, Rodolphe; Martinez, Eric; Vialla, François; Giquel, Chloé; Thonnat-Marin, Aurélie; De Vos, John

    2016-01-01

    Recent advances in stem cells and gene engineering have paved the way for the generation of interspecies chimeras, such as animals bearing an organ from another species. The production of a rat pancreas by a mouse has demonstrated the feasibility of this approach. The next step will be the generation of larger chimeric animals, such as pigs bearing human organs. Because of the dramatic organ shortage for transplantation, the medical needs for such a transgressive practice are indisputable. However, there are serious technical barriers and complex ethical issues that must be discussed and solved before producing human organs in animals. The main ethical issues are the risks of consciousness and of human features in the chimeric animal due to a too high contribution of human cells to the brain, in the first case, or for instance to limbs, in the second. Another critical point concerns the production of human gametes by such chimeric animals. These worst-case scenarios are obviously unacceptable and must be strictly monitored by careful risk assessment, and, if necessary, technically prevented. The public must be associated with this ethical debate. Scientists and physicians have a critical role in explaining the medical needs, the advantages and limits of this potential medical procedure, and the ethical boundaries that must not be trespassed. If these prerequisites are met, acceptance of such a new, borderline medical procedure may prevail, as happened before for in-vitro fertilization or preimplantation genetic diagnosis. PMID:27356872

  6. T and B lymphocytes in the marmoset: a natural haemopoietic chimera

    Energy Technology Data Exchange (ETDEWEB)

    Niblack, G.D.; Gengozian, N.

    1976-01-01

    The thymus-derived (T) lymphocyte and bone marrow-derived (B) lymphocyte populations of the marmoset were characterized using specific cell surface markers. Approximately 85% of the thymocytes formed rosettes with neuraminidase-treated sheep erythrocytes (E/sub n/). The percentage (approximately 69%) of peripheral blood lymphocytes (PBL) forming rosettes with E/sub n/ was the same as that which stained with fluorescently labelled goat anti-marmoset thymocyte serum (ATS). These two assays identified the same cell population since treatment of cells with ATS and complement resulted in a concomitant decrease in E/sub n/ rosette formation. Marmoset PBL also formed rosettes with human erythrocytes sensitized with antibody and complement (HEAC); since the percentage (approximately 20%) HEAC rosette was the same as that of cells stained with fluorescently labelled goat anti-marmoset IgG, these cells were considered to be B cells. A small percentage of cells (aproximately 1.5%) possessed both types of receptors. The mean percentages of T and B cells present in PBL of single-born, presumably non-chimeric animals, were the same as that of isosexual and heterosexual chimeras.

  7. Numerical Simulation of Rotor-aerodynamic Surface Interaction in Hover Using Moving Chimera Grid

    Institute of Scientific and Technical Information of China (English)

    LI Yibo; MA Dongli

    2012-01-01

    Three-dimensional unsteady Navier-Stokes equations are numerically solved to simulate the aerodynamic interaction of rotor,canard and horizontal tail in hover based on moving chimera grid.The variations of unsteady aerodynamic forces and moments of the canard and horizontal tail with respect to the rotor azimuth are analyzed with the deflection angle set at 0° and 50°,respectively.The pressure map of aerodynamic surfaces and velocity vector distribution of flow field are investigated to get better understanding of the unsteady aerodynamic interaction.The result shows that the canard and horizontal tail present different characteristics under the downwash of the rotor.The canard produces much vertical force loss with low amplitude fluctuation.Contrarily,the horizontal tail,which is within the flow field induced by the down wash of the rotor,produces only less vertical force loss,but the amplitudes of the lift and pitching moment are larger,implying that a potential deflection angle scheme in hover is 50° for the canard and 0° for the horizontal tail.

  8. Scalar-Quark Systems and Chimera Hadrons in SU(3)_c Lattice QCD

    CERN Document Server

    Iida, H; Takahashi, T T

    2007-01-01

    Light scalar-quarks \\phi (colored scalar particles or idealized diquarks) and their color-singlet hadronic states are studied with quenched SU(3)_c lattice QCD in terms of mass generation in strong interaction without chiral symmetry breaking. We investigate ``scalar-quark mesons'' \\phi^\\dagger \\phi and ``scalar-quark baryons'' \\phi\\phi\\phi which are the bound states of scalar-quarks \\phi. We also investigate the bound states of scalar-quarks \\phi and quarks \\psi, i.e., \\phi^\\dagger \\psi, \\psi\\psi\\phi and \\phi\\phi\\psi, which we name ``chimera hadrons''. All the new-type hadrons including \\phi are found to have a large mass even for zero bare scalar-quark mass m_\\phi=0 at a^{-1}\\simeq 1GeV. We find that the constituent scalar-quark and quark picture is satisfied for all the new-type hadrons. Namely, the mass of the new-type hadron composed of m \\phi's and n \\psi's, M_{{m}\\phi+{n}\\psi}, satisfies M_{{m}\\phi+{n}\\psi}\\simeq {m} M_\\phi +{n} M_\\psi, where M_\\phi and M_\\psi are the constituent scalar-quark and quark...

  9. Clonal deletion: A mechanism of tolerance in mixed bone marrow chimeras

    International Nuclear Information System (INIS)

    The mechanism of antigen-specific immunologic unresponsiveness which results from lethal irradiation and mixed (syngeneic-allogeneic) bone marrow cell (BMC) reconstitution is unknown. To determine whether clonal deletion is the mechanism of tolerance in this model, monoclonal antibody (Mab) RR-4-4, specific for a T-cell receptor (V beta 6) reactive against the minor alloantigen MLsa, was employed. Six-week-old B10 mice (H-2b, Mlsb, Thyl.2) were tolerized to AKR antigens (H-2k, Mlsa, Thyl.1) by whole body irradiation (950 R) and iv infusion of T-cell-depleted (TCD) B10 BMC + non-TCD AKR BMC. Chimerism and antigen-specific tolerance were documented by flow microfluorometry (FMF), skin grafting, mixed lymphocyte reaction, and cell-mediated lympholysis. When tolerant B10 mice (n = 15) had accepted AKR skin grafts for greater than 100 days, these animals were studied for the presence of host V beta 6+ T cells using Mab RR-4-4. FMF revealed that 0-5% of host (B10) lymph node and spleen cells from chimeras were V beta 6+ while 15-20% of lymph node and spleen cells from control B10 mice expressed V beta 6. These data demonstrate that clonal deletion occurs in the lethal irradiation-mixed reconstitution model as evidenced by the near total elimination of Mlsa-reactive V beta 6+ T cells and suggest that it maybe a mechanism responsible for tolerance in adult mice

  10. All together now: Analogies between chimera state collapses and epileptic seizures

    Science.gov (United States)

    Andrzejak, Ralph G.; Rummel, Christian; Mormann, Florian; Schindler, Kaspar

    2016-03-01

    Conceptually and structurally simple mathematical models of coupled oscillator networks can show a rich variety of complex dynamics, providing fundamental insights into many real-world phenomena. A recent and not yet fully understood example is the collapse of coexisting synchronous and asynchronous oscillations into a globally synchronous motion found in networks of identical oscillators. Here we show that this sudden collapse is promoted by a further decrease of synchronization, rather than by critically high synchronization. This strikingly counterintuitive mechanism can be found also in nature, as we demonstrate on epileptic seizures in humans. Analyzing spatiotemporal correlation profiles derived from intracranial electroencephalographic recordings (EEG) of seizures in epilepsy patients, we found a pronounced decrease of correlation at the seizure onsets. Applying our findings in a closed-loop control scheme to models of coupled oscillators in chimera states, we succeed in both provoking and preventing outbreaks of global synchronization. Our findings not only advance the understanding of networks of coupled dynamics but can open new ways to control them, thus offering a vast range of potential new applications.

  11. All together now: Analogies between chimera state collapses and epileptic seizures.

    Science.gov (United States)

    Andrzejak, Ralph G; Rummel, Christian; Mormann, Florian; Schindler, Kaspar

    2016-01-01

    Conceptually and structurally simple mathematical models of coupled oscillator networks can show a rich variety of complex dynamics, providing fundamental insights into many real-world phenomena. A recent and not yet fully understood example is the collapse of coexisting synchronous and asynchronous oscillations into a globally synchronous motion found in networks of identical oscillators. Here we show that this sudden collapse is promoted by a further decrease of synchronization, rather than by critically high synchronization. This strikingly counterintuitive mechanism can be found also in nature, as we demonstrate on epileptic seizures in humans. Analyzing spatiotemporal correlation profiles derived from intracranial electroencephalographic recordings (EEG) of seizures in epilepsy patients, we found a pronounced decrease of correlation at the seizure onsets. Applying our findings in a closed-loop control scheme to models of coupled oscillators in chimera states, we succeed in both provoking and preventing outbreaks of global synchronization. Our findings not only advance the understanding of networks of coupled dynamics but can open new ways to control them, thus offering a vast range of potential new applications.

  12. Mouse embryos and chimera cloned from neural cells in the postnatal cerebral cortex.

    Science.gov (United States)

    Makino, Hatsune; Yamazaki, Yukiko; Hirabayashi, Takahiro; Kaneko, Ryosuke; Hamada, Shun; Kawamura, Yoshimi; Osada, Tomoharu; Yanagimachi, Ryuzo; Yagi, Takeshi

    2005-01-01

    Cloning of mice has been achieved by transferring nuclei of various types of somatic cell nuclei into enucleated oocytes. However, all attempts to produce live cloned offspring using the nuclei of neurons from adult cerebral cortex have failed. Previously we obtained cloned mice using the nuclei of neural cells collected from fetal cerebral cortex. Here, we attempted to generate cloned mice using differentiated neurons from the cerebral cortex of postnatal (day 0-4) mice. Although we were unable to obtain live cloned pups, many fetuses reached day 10.5 days of development. These fetuses showed various abnormalities such as spherical omission of the neuroepithelium, collapsed lumen of neural tube, and aberrant expressions of marker proteins of neurons. We produced chimeric mice in which some hair cells and kidney cells were originated from differentiated neurons. In chimeric fetuses, LacZ-positive donor cells were in all three germ cell layers. However, chimeras with large contribution of donor-derived cells were not obtained. These results indicate that nuclei of differentiated neurons have lost their developmental totipotency. In other words, the conventional nuclear transfer technique does not allow nuclei of differentiated neurons to undergo complete genomic reprogramming required for normal embryonic development.

  13. The HERMES recoil detector

    Energy Technology Data Exchange (ETDEWEB)

    Van Hulse, Charlotte, E-mail: charlotte@inwfsun1.UGent.b [Gent University Department of Subatomic and Radiation Physics, Proeftuinstraat 86, 9000 Gent (Belgium)

    2010-11-01

    In order to allow for the detection of low momentum particles, originating from the scattering of a 27.6 GeV lepton beam off a fixed gaseous target at the HERMES experiment at DESY in Hamburg (Germany), a dedicated recoil detector was installed. It consists of a silicon strip detector, located inside the beam vacuum, a scintillating fiber tracker and a photon detector, around a 150 mm long target cell made out of a 75{mu}m thick aluminum tube. The full detector assembly is mounted inside a 1 T super-conducting solenoid and is able to detect protons and pions with momenta up to 1.40 GeV/c and photons in the region surrounding the target cell. The detector has been operational from February 2006 until June 2007. The commissioning and performance of the detector are presented in this paper.

  14. Neutrino factory near detector

    OpenAIRE

    Bogomilov, M.; Y. Karadzhov; Matev, R.; Tsenov, R.; Laing, A.; F.J.P. Soler

    2013-01-01

    The neutrino factory is a facility for future precision studies of neutrino oscillations. A so-called near detector is essential for reaching the required precision for a neutrino oscillation analysis. The main task of the near detector is to measure the flux of the neutrino beam. Such a high intensity neutrino source like a neutrino factory provides also the opportunity for precision studies of various neutrino interaction processes in the near detector. We discuss the design concepts of suc...

  15. Noble Gas Detectors

    CERN Document Server

    Aprile, Elena; Bolozdynya, Alexander I; Doke, Tadayoshi

    2006-01-01

    This book discusses the physical properties of noble fluids, operational principles of detectors based on these media, and the best technical solutions to the design of these detectors. Essential attention is given to detector technology: purification methods and monitoring of purity, information readout methods, electronics, detection of hard ultra-violet light emission, selection of materials, cryogenics etc.The book is mostly addressed to physicists and graduate students involved in the preparation of fundamental next generation experiments, nuclear engineers developing instrumentation

  16. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS (A Toroidal LHC Apparatus). The ALFA system is composed by four stations installed in the LHC tunnel 240 m away from the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronics for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  17. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS/LHC. The ALFA system is composed by two stations installed in the LHC tunnel 240 m away from each side of the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronic for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  18. LHCb Detector Performance

    CERN Document Server

    AUTHOR|(CDS)2075808; Adeva, Bernardo; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Pessina, Gianluigi; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2015-01-01

    The LHCb detector is a forward spectrometer at the Large Hadron Collider (LHC) at CERN. The experiment is designed for precision measurements of CP violation and rare decays of beauty and charm hadrons. In this paper the performance of the various LHCb sub-detectors and the trigger system are described, using data taken from 2010 to 2012. It is shown that the design criteria of the experiment have been met. The excellent performance of the detector has allowed the LHCb collaboration to publish a wide range of physics results, demonstrating LHCb's unique role, both as a heavy flavour experiment and as a general purpose detector in the forward region.

  19. Detector support head

    International Nuclear Information System (INIS)

    The support head of detectors for densitometric measurements of the regional function of lungs using gamma radiation consists of a group of detectors placed in a common rack. The detectors are placed on holders with adjustable height which allow side movement. The holders are slidably connected to the converging quide rail on the frame via arms. Between the holders and the rack is fitted the drive mechanism consisting of a screw. The design allows the stable adjustment of detectors on the lung field during examination and thereby allows the comparison of results of measurements carried out at different times. (J.B.). 2 figs

  20. Dynamics of Somatic Cell-Lineage Competition in Chimeras of Hydractinia symbiolongicarpus (Cnidaria: Hydrozoa) Dinámica de competencia entre líneas celulares somáticas en quimeras de Hydractinia symbiolongicarpus (Cnidaria: Hydrozoa)

    OpenAIRE

    RYAN S SCHWARZ; Cadavid, Luis F.

    2007-01-01

    Sessile colonial invertebrates often fuse with conspecifics to form chimeras. Chimerism represents an unequivocal instance of withinindividual selection where genetically different celllineages compete for representation in the somatic and gametic pools. We analyzed temporal and spatial variations in somatic celllineage composition of laboratoryestablished chimeras of the hydroid Hydractinia symbiolongicarpus (Cnidaria: Hydrozoa). Using three clones with different allotyp...

  1. Construction of eSRK Chimeras and Interaction between eSRK Chimeras and SCRs from Brassica oleracea L.%甘蓝eSRK重组体的构建及其与SCR的相互作用

    Institute of Scientific and Technical Information of China (English)

    韦静宜; 高启国; 任雪松; 王小佳; 李成琼; 宋明

    2012-01-01

    SRK与SCR是甘蓝自交不亲和雌雄性决定因子,两者间相互作具有单倍型特异性.为了探讨HVⅠ/Ⅱ区域在SRK单倍型特异性及其与SCR互作中的作用,采用重组技术构建甘蓝不同单倍型eSRK (SRKE与SRKF)间的重组体eSRKE-1、eSRKE-2和eSRKE-3,用酵母双杂交系统3检测各eSRK重组体与SCR之间的相互作用.结果表明:SCRE能与eSRKE作用,而不能与eSRKF作用,说明eSRKE、eSRKF属于不同单倍型;SCRE与重组体eSRKE-1、eSRKE-2、eSRKE-3均不发生作用,HVⅠ和HVⅡ区域内差异的氨基酸位点共同参与了与SCR的作用;SCRF不能与eSRKE-1、eSRKE-2、eSRKE-3作用,替换HVⅠ/Ⅱ区域后并不能改变SRK的单倍型.%Self-incompatibility in Brassica is mediated by allele-specific interactions between stigma-expressed 5-locus receptor kinase (SRK) and pollen coat-localized 5-locus cysteinerich (SCR) ligands encoded by the 5-locus haplotype. To identify amino acid fragments within the SRK extracellular domain (eSRK) that are required for ligand-selective activation, we constructed chi-meric eSRK between two 5-locus haplotypes in Brassica oleracea, and identified the interaction between eSRK chimeras and SCRs by yeast two-hybrid system. The results showed that SRKE (not chimera) could interact with SCRE, and SRKF could interact with SCRF. All of eSRK chimeras could not interact with SCRs. The hypervariable regions, HVI and HVII, were essential for specificity in the SRK-SCR interaction. However, eSRK chimeras could not interact with SCRp, although they contained hypervariable regions come from eSRKp, which should be related with the overall sequence or 3D conformation of the segments determining SI specificity.

  2. LHCb detector performance

    NARCIS (Netherlands)

    Aaij, R.; Adeva, B.; Adinol, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bettler, M. -O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjornstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brambach, T.; Bressieux, J.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Brown, H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Perez, D. Campora; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carson, L.; Akiba, K. Carvalho; Casse, G.; Cassina, L.; Garcia, L. Castillo; Cattaneo, M.; Cauet, Ch.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S. -F.; Chiapolini, N.; Chrzaszcz, M.; Ciba, K.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A. C.; Torres, M. Cruz; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Deleage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Di Canto, A.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suarez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Faerber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Rodrigues, F. Ferreira; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Pardinas, J.; Garofoli, J.; Tico, J. Garra; Garrido, L.; Gascon, D.; Gaspar, C.; Gauld, R.; Gavardi, L.; Geraci, A.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Goebel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Gandara, M. Grabalosa; Graciani Diaz, R.; Cardoso, L. A. Granado; Grauges, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Gruenberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Hess, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Hunt, P.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jaton, P.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kozlinskiy, A.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J. -P.; Lefevre, R.; Leflat, A.; Lefrancois, J.; Leo, S.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lopez-March, N.; Lowdon, P.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Maerki, R.; Marks, J.; Martellotti, G.; Martens, A.; Sanchez, A. Martin; Martinelli, M.; Santos, D. Martinez; Martinez Vidal, F.; Tostes, D. Martins; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; McSkelly, B.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M. -N.; Moggi, N.; Rodriguez, J. Molina; Monteil, S.; Morandin, M.; Morawski, P.; Morda, A.; Morello, M. J.; Moron, J.; Morris, A. -B.; Mountain, R.; Muheim, F.; Mueller, K.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Nicol, M.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Oggero, S.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Orlandea, M.; Goicochea, J. M. Otalora; Owen, P.; Oyanguren, A.; Pal, B. K.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Parkinson, C. J.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Altarelli, M. Pepe; Perazzini, S.; Perret, P.; Perrin-Terrin, M.; Pescatore, L.; Pesen, E.; Pessina, G.; Petridis, K.; Petrolini, A.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilar, T.; Pinci, D.; Pistone, A.; Playfer, S.; Casasus, M. Plo; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, W.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Perez, P. Rodriguez; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Valls, P. Ruiz; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Guimaraes, V. Salustino; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M. -H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Coutinho, R. Silva; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, N. A.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; De Paula, B. Souza; Spaan, B.; Sparkes, A.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Subbiah, V. K.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Tran, M. T.; Tresch, M.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Garcia, M. Ubeda; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Gomez, R. Vazquez; Vazquez Regueiro, P.; Vazzquez Sierra, C.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voss, C.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Whitehead, M.; Wicht, J.; Wiedner, D.; Wilkinson, G.; Williams, M. P.; Williams, M.; Wilschut, H. W.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, W. C.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.; Zvyagin, A.

    2015-01-01

    The LHCb detector is a forward spectrometer at the Large Hadron Collider (LHC) at CERN. The experiment is designed for precision measurements of CP violation and rare decays of beauty and charm hadrons. In this paper the performance of the various LHCb sub-detectors and the trigger system are descri

  3. The ATLAS pixel detector

    OpenAIRE

    Cristinziani, M.

    2007-01-01

    After a ten years planning and construction phase, the ATLAS pixel detector is nearing its completion and is scheduled to be integrated into the ATLAS detector to take data with the first LHC collisions in 2007. An overview of the construction is presented with particular emphasis on some of the major and most recent problems encountered and solved.

  4. Borner Ball Neutron Detector

    Science.gov (United States)

    2002-01-01

    The Bonner Ball Neutron Detector measures neutron radiation. Neutrons are uncharged atomic particles that have the ability to penetrate living tissues, harming human beings in space. The Bonner Ball Neutron Detector is one of three radiation experiments during Expedition Two. The others are the Phantom Torso and Dosimetric Mapping.

  5. ALICE Silicon Strip Detector

    CERN Multimedia

    Nooren, G

    2013-01-01

    The Silicon Strip Detector (SSD) constitutes the two outermost layers of the Inner Tracking System (ITS) of the ALICE Experiment. The SSD plays a crucial role in the tracking of the particles produced in the collisions connecting the tracks from the external detectors (Time Projection Chamber) to the ITS. The SSD also contributes to the particle identification through the measurement of their energy loss.

  6. CMS pixel detector Overview

    CERN Document Server

    Cremaldi, L M

    2003-01-01

    An overview of the compact muon solenoid pixel detector effort is presented. Pixel detectors are being built for use at the large hadron collider beginning in the year 2007. It is reported that a good progress is made in 2002 on the critical issues of readout chip and token bit manager design, bump bonding and sensor testing. (Edited abstract) 8 Refs.

  7. Drift chamber detectors

    International Nuclear Information System (INIS)

    A review of High Energy Physics detectors based on drift chambers is presented. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysied, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author)

  8. Alkali ionization detector

    Science.gov (United States)

    Hrizo, John; Bauerle, James E.; Witkowski, Robert E.

    1982-01-01

    A calibration filament containing a sodium-bearing compound is included in combination with the sensing filament and ion collector plate of a sodium ionization detector to permit periodic generation of sodium atoms for the in-situ calibration of the detector.

  9. CMS Detector Posters

    CERN Multimedia

    2016-01-01

    CMS Detector posters (produced in 2000): CMS installation CMS collaboration From the Big Bang to Stars LHC Magnetic Field Magnet System Trackering System Tracker Electronics Calorimetry Eletromagnetic Calorimeter Hadronic Calorimeter Muon System Muon Detectors Trigger and data aquisition (DAQ) ECAL posters (produced in 2010, FR & EN): CMS ECAL CMS ECAL-Supermodule cooling and mechatronics CMS ECAL-Supermodule assembly

  10. The LDC detector concept

    Indian Academy of Sciences (India)

    Ties Behnke; LDC Concept Group

    2007-11-01

    In preparation of the experimental program at the international linear collider (ILC), the large detector concept (LDC) is being developed. The main points of the LDC are a large volume gaseous tracking system, combined with high precision vertex detector and an extremely granular calorimeter. The main design force behind the LDC is the particle flow concept.

  11. ALICE Photon Multiplicity Detector

    CERN Multimedia

    Nayak, T

    2013-01-01

    Photon Multiplicity Detector (PMD) measures the multiplicity and spatial distribution of photons in the forward region of ALICE on a event-by-event basis. PMD is a pre-shower detector having fine granularity and full azimuthal coverage in the pseudo-rapidity region 2.3 < η < 3.9.

  12. The TESLA Detector

    OpenAIRE

    Moenig, Klaus

    2001-01-01

    For the superconducting linear collider TESLA a multi purpose detector has been designed. This detector is optimised for the important physics processes expected at a next generation linear collider up to around 1 TeV and is designed for the specific environment of a superconducting collider.

  13. Pixel detector readout chip

    CERN Multimedia

    1991-01-01

    Close-up of a pixel detector readout chip. The photograph shows an aera of 1 mm x 2 mm containing 12 separate readout channels. The entire chip contains 1000 readout channels (around 80 000 transistors) covering a sensitive area of 8 mm x 5 mm. The chip has been mounted on a silicon detector to detect high energy particles.

  14. Functional assignment by Chimera construction of the domain affecting heterotropic activation of deoxyadenosine kinase from Lactobacillus acidophilus R-26.

    Science.gov (United States)

    Guo, S; Ives, D H

    1998-10-01

    The heterodimeric subunits of deoxyadenosine kinase (dAK)-deoxyguanosine kinase (dGK) from Lactobacillus acidophilus R-26 exhibit contrasting conformations manifested in the nearly unidirectional heterotropic activation of dAK when dGK binds deoxyguanosine. This is mediated, in part, by the conserved Ras switch I-like sequence (residues 153-161) [Guo et al. (1997) J. Biol. Chem. 272, 6890-6897]. In an attempt to identify domains differentiating the specificities of dAK and dGK, we constructed several chimeras splicing heterodimeric dAK within this region. In Chimera-III, dAK residues 120-170 were replaced by the homologous section of dGK. dAK activity was elevated 40%, but although it retained its original specificity and Km values, it could no longer be activated by deoxyguanosine. Moreover, both the activated dAK and the "dAK" of Chimera-III exhibited (i) an increased Ks for the leading substrate ATP-Mg2+, suggesting the formation of intermediate enzyme species along their respective kinetic pathways, and (ii) broadened and lower pH optima for the dAK activities. These observations further indicate the importance of dAK residues 120-170, including the Ras-like segment, in catalysis and heterotropic activation. The other conformational properties of dAK (e.g. self-inactivity and MgATP being the leading substrate) were unaltered by this substitution, thus localizing the responsible domains even further upstream.

  15. Newcastle disease virus chimeras expressing the Hemagglutinin- Neuraminidase protein of mesogenic strain exhibits an enhanced anti-hepatoma efficacy.

    Science.gov (United States)

    He, Jinjiao; Pan, Ziye; Tian, Guiyou; Liu, Xin; Liu, Yunye; Guo, Xiaochen; An, Ying; Song, Liying; Wu, Hongsong; Cao, Hongwei; Yu, Dan; Che, Ruixiang; Xu, Pengfei; Rasoul, Lubna M; Li, Deshan; Yin, Jiechao

    2016-08-01

    Newcastle disease virus (NDV) is an intrinsically tumor-specific virus, many researchers have reported that lentogenic NDV is a safe and effective agent for human cancer therapy. It had been demonstrated that the amino acid sequence of the fusion protein cleavage site is a major factor in the pathogenicity and anti-tumor efficacy of rNDV. However, the role of Hemagglutinin-Neuraminidase (HN) gene that contributes to virulence and anti-tumor efficacy remains undefined. To assess the role of HN gene in virus pathogenicity and anti-tumor efficacy, a reverse genetic system was developed using the lentogenic NDV Clone30 strain to provide backbone for gene exchange. Chimeric virus (rClone30-Anh(HN)) created by exchange of the HN gene of lentogenic strain Clone30 with HN gene of mesogenic strain produce no significant changes in virus pathogenicity as assessed by conducting the mean death time (MDT) and intracerebral pathogenicity index (ICPI) assays. In vitro, infection with chimeras could induce the formation of syncytium relative significantly in HepG2 cells. Furthermore, chimeras was shown to induce the cell apoptosis via MTT and Annexin V-PI assays, reduce mitochondrial membrane potential and increase the mRNA transcription level of caspase 3. In vivo, ICR mice carrying tumor of hepatoma H22 cells were treated via intratumoral injection of chimeric virus. The treatment of chimera shows an obvious suppression in tumor volume. These results suggest that it could be an ideal approach to enhance the antitumor ability of Newcastle disease virus and highlighted the potential therapeutic application of rClone30-Anh(HN) as a viral vector to deliver foreign genes for treatment of cancers. PMID:27164362

  16. Detector R&D

    CERN Document Server

    Behnke, T

    2004-01-01

    The next big project in high energy physics should be a high energy e /sup +/e/sup -/ linear collider, operating at energies up to around 1 TeV. A vigorous R&D program has started to prepare the grounds for a detector at such a machine. The amounts of precision data expected at this machine make a novel approach to the reconstruction of events necessary; the particle flow ansatz. This in turn influences significantly the design of a detector for such an experiment. Apart from work ongoing for the linear collider detector, preparations are under way for an update of the LHC. This requires extremely radiation hard detectors. In this paper the state of the different detector development projects is reviewed. (21 refs).

  17. The Solenoidal Detector Collaboration silicon detector system

    International Nuclear Information System (INIS)

    Silicon tracking systems will be fundamental components of the tracking systems for both planned major SSC experiments. Despite its seemingly small size, it occupies a volume of more than 5 meters in length and 1 meter in diameter and is an order of magnitude larger than any silicon detector system previously built. This report discusses its design and operation

  18. CONSTRUCTION OF HU-PBL/SCID CHIMERAS AND DEVELOPMENT OF EBV-RELATED LYMPHOMAS

    Institute of Scientific and Technical Information of China (English)

    Run-liang Gan; Ke Lan; Zhi-hua Yin; Li-jiang Wang; Ying Song; Kai-tai Yao

    2005-01-01

    Objective To construct hu-PBL/SCID chimeras and to investigate the development of lymphoma and oncogenicity of the Epstein-Barr virus (EBV).Mtehods Human peripheral blood lymphocytes (PBLs) were isolated from healthy adult donors and transplanted intraperitoneally into severe combined immunodeficient (SCID) mice. Mice with hu-PBL engraftment from healthy EBV seronegative donors were injected intraperitoneally with EBV-containing supematant from suspension culture of B95-8 cell line (active infection), whereas mice receiving lymphocytes from healthy EBV seropositive donors were not re-infected with B95-8 derived EBV (latent infection). Pathological examination and molecular analysis were performed on experimental animals and induced neoplasms.Results In the early stage of this experiment, 12 mice died of acute graft-versus-host disease, mortality was 34.3%(12/35 mice) with an average life span of 17.5 days. In 19 survival hu-PBL/SCID chimeric recipients from 12 healthy donors,tumor incidence was 84.2% (16/19 mice). The average survival time of tumor-bearing mice was 65.5 days. EBV-related neoplasms in SCID mice were nodular tumors with aggressive and fatal features. Histological morphology of tumors exhibited diffuse large cell lymphomas. Immunohistochemistry revealed that LCA (CD45) and L26 (CD20) were positive, but both PS1 (CD3) and UCHL-1 (CD45RO) were negative, and EBV products ZEBRA, LMP1, and EBNA2 were expressed in a small number of tumor cells. EB virus particles were seen in the nuclei of some tumor cells by electron microscopy, and EBV DNA could be amplified in the tumor tissues by PCR. In situ hybridization indicated that the nuclei of tumor cells contained human-specific Alu sequence.Conclusions EBV-induced tumors were human B-cell malignant lymphomas. We obtained direct causative evidence dealing with EBV-associated tumor deriving from normal human cells.

  19. A chimera grid scheme. [multiple overset body-conforming mesh system for finite difference adaptation to complex aircraft configurations

    Science.gov (United States)

    Steger, J. L.; Dougherty, F. C.; Benek, J. A.

    1983-01-01

    A mesh system composed of multiple overset body-conforming grids is described for adapting finite-difference procedures to complex aircraft configurations. In this so-called 'chimera mesh,' a major grid is generated about a main component of the configuration and overset minor grids are used to resolve all other features. Methods for connecting overset multiple grids and modifications of flow-simulation algorithms are discussed. Computational tests in two dimensions indicate that the use of multiple overset grids can simplify the task of grid generation without an adverse effect on flow-field algorithms and computer code complexity.

  20. Measurement of the 238U neutron-capture cross section and gamma-emission spectra from 10 eV to 100 keV using the DANCE detector at LANSCE

    Energy Technology Data Exchange (ETDEWEB)

    Ullmann, John L [Los Alamos National Laboratory; Couture, A J [Los Alamos National Laboratory; Keksis, A L [Los Alamos National Laboratory; Vieira, D J [Los Alamos National Laboratory; O' Donnell, J M [Los Alamos National Laboratory; Jandel, M [Los Alamos National Laboratory; Haight, R C [Los Alamos National Laboratory; Rundberg, R S [Los Alamos National Laboratory; Kawano, T [Los Alamos National Laboratory; Chyzh, A [NORTH CAROLINA STATE UNIV; Baramsai, B [NORTH CAROLINA STATE UNIV; Wu, C Y [LLNL; Mitchell, G E [NORTH CAROLINA STATE UNIV; Becker, J A [LLNL; Krticka, M [CHARLES UNIV

    2010-01-01

    A careful new measurement of the {sup 238}U(n,{gamma}) cross section from 10 eV to 100 keV has been made using the DANCE detector at LANSCE. DANCE is a 4{pi} calorimetric scintillator array consisting of 160 BaF{sub 2} crystals. Measurements were made on a 48 mg/cm{sup 2} depleted uranium target. The cross sections are in general good agreement with previous measurements. The gamma-ray emission spectra, as a function of gamma multiplicity, were also measured and compared to model calculations.

  1. The HERMES recoil detector

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Giessen Univ. (Germany). Physikalisches Inst.; Michigan Univ., Ann Arbor, MI (United States). Randall Laboratory of Physics; Aschenauer, E.C. [DESY, Zeuthen (Germany); Belostotski, S. [B.P. Konstantinov Petersburg Nuclear Physics Insitute, Gatchina (Russian Federation)] [and others; Collaboration: HERMES Recoil Detector Group

    2013-02-15

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1Tm. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  2. The HERMES recoil detector

    Science.gov (United States)

    Airapetian, A.; Aschenauer, E. C.; Belostotski, S.; Borisenko, A.; Bowles, J.; Brodski, I.; Bryzgalov, V.; Burns, J.; Capitani, G. P.; Carassiti, V.; Ciullo, G.; Clarkson, A.; Contalbrigo, M.; De Leo, R.; De Sanctis, E.; Diefenthaler, M.; Di Nezza, P.; Düren, M.; Ehrenfried, M.; Guler, H.; Gregor, I. M.; Hartig, M.; Hill, G.; Hoek, M.; Holler, Y.; Hristova, I.; Jo, H. S.; Kaiser, R.; Keri, T.; Kisselev, A.; Krause, B.; Krauss, B.; Lagamba, L.; Lehmann, I.; Lenisa, P.; Lu, S.; Lu, X.-G.; Lumsden, S.; Mahon, D.; Martinez de la Ossa, A.; Murray, M.; Mussgiller, A.; Nowak, W.-D.; Naryshkin, Y.; Osborne, A.; Pappalardo, L. L.; Perez-Benito, R.; Petrov, A.; Pickert, N.; Prahl, V.; Protopopescu, D.; Reinecke, M.; Riedl, C.; Rith, K.; Rosner, G.; Rubacek, L.; Ryckbosch, D.; Salomatin, Y.; Schnell, G.; Seitz, B.; Shearer, C.; Shutov, V.; Statera, M.; Steijger, J. J. M.; Stenzel, H.; Stewart, J.; Stinzing, F.; Trzcinski, A.; Tytgat, M.; Vandenbroucke, A.; Van Haarlem, Y.; Van Hulse, C.; Varanda, M.; Veretennikov, D.; Vilardi, I.; Vikhrov, V.; Vogel, C.; Yaschenko, S.; Ye, Z.; Yu, W.; Zeiler, D.; Zihlmann, B.

    2013-05-01

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with a field strength of 1T. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  3. ATLAS Detector Interface Group

    CERN Document Server

    Mapelli, L

    Originally organised as a sub-system in the DAQ/EF-1 Prototype Project, the Detector Interface Group (DIG) was an information exchange channel between the Detector systems and the Data Acquisition to provide critical detector information for prototype design and detector integration. After the reorganisation of the Trigger/DAQ Project and of Technical Coordination, the necessity to provide an adequate context for integration of detectors with the Trigger and DAQ lead to organisation of the DIG as one of the activities of Technical Coordination. Such an organisation emphasises the ATLAS wide coordination of the Trigger and DAQ exploitation aspects, which go beyond the domain of the Trigger/DAQ project itself. As part of Technical Coordination, the DIG provides the natural environment for the common work of Trigger/DAQ and detector experts. A DIG forum for a wide discussion of all the detector and Trigger/DAQ integration issues. A more restricted DIG group for the practical organisation and implementation o...

  4. The HERMES recoil detector

    International Nuclear Information System (INIS)

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1Tm. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  5. PIN Diode Detectors

    Science.gov (United States)

    Ramírez-Jiménez, F. J.

    2008-07-01

    A review of the application of PIN diodes as radiation detectors in particle counting, X- and γ-ray spectroscopy, medical applications and charged particle spectroscopy is presented. As a practical example of its usefulness, a PIN diode and a low noise preamplifier are included in a nuclear spectroscopy chain for X-ray measurements. This is a laboratory session designed to review the main concepts needed to set up the detector-preamplifier array and to make measurements of X-ray energy spectra with a room temperature PIN diode. The results obtained are compared with those obtained with a high resolution cooled Si-Li detector.

  6. The Silicon Cube detector

    Energy Technology Data Exchange (ETDEWEB)

    Matea, I.; Adimi, N. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France); Blank, B. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France)], E-mail: blank@cenbg.in2p3.fr; Canchel, G.; Giovinazzo, J. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France); Borge, M.J.G.; Dominguez-Reyes, R.; Tengblad, O. [Insto. Estructura de la Materia, CSIC, Serrano 113bis, E-28006 Madrid (Spain); Thomas, J.-C. [GANIL, CEA/DSM - CNRS/IN2P3, BP 55027, F-14076 Caen Cedex 5 (France)

    2009-08-21

    A new experimental device, the Silicon Cube detector, consisting of six double-sided silicon strip detectors placed in a compact geometry was developed at CENBG. Having a very good angular coverage and high granularity, it allows simultaneous measurements of energy and angular distributions of charged particles emitted from unbound nuclear states. In addition, large-volume Germanium detectors can be placed close to the collection point of the radioactive species to be studied. The setup is ideally suited for isotope separation on-line (ISOL)-type experiments to study multi-particle emitters and was tested during an experiment at the low-energy beam line of SPIRAL at GANIL.

  7. Microfluidic Scintillation Detectors

    CERN Multimedia

    Microfluidic scintillation detectors are devices of recent introduction for the detection of high energy particles, developed within the EP-DT group at CERN. Most of the interest for such technology comes from the use of liquid scintillators, which entails the possibility of changing the active material in the detector, leading to an increased radiation resistance. This feature, together with the high spatial resolution and low thickness deriving from the microfabrication techniques used to manufacture such devices, is desirable not only in instrumentation for high energy physics experiments but also in medical detectors such as beam monitors for hadron therapy.

  8. Layered semiconductor neutron detectors

    Science.gov (United States)

    Mao, Samuel S; Perry, Dale L

    2013-12-10

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  9. Performance of GLD detector

    Indian Academy of Sciences (India)

    T Yoshioka

    2007-12-01

    Most of the important physics processes to be studied in the international linear collider (ILC) experiment have multi-jets in the final state. In order to achieve better jet energy resolution, the so-called particle flow algorithm (PFA) will be employed and there is a general consensus that PFA derives overall ILC detector design. Four detector concepts for the ILC experiment have been proposed so far in the world; the GLD detector that has a large inner calorimeter radius, which is considered to have an advantage for a PFA, is one of them. In this paper, general scheme and performance of the GLD-PFA will be presented.

  10. ATLAS Inner Detector Alignment

    CERN Document Server

    Bocci, A

    2008-01-01

    The ATLAS experiment is a multi-purpose particle detector that will study high-energy particle collisions produced by the Large Hadron Collider at CERN. In order to achieve its physics goals, the ATLAS tracking requires that the positions of the silicon detector elements have to be known to a precision better than 10 μm. Several track-based alignment algorithms have been developed for the Inner Detector. An extensive validation has been performed with simulated events and real data coming from the ATLAS. Results from such validation are reported in this paper.

  11. Strain-transcending immune response generated by chimeras of the malaria vaccine candidate merozoite surface protein 2

    Science.gov (United States)

    Krishnarjuna, Bankala; Andrew, Dean; MacRaild, Christopher A.; Morales, Rodrigo A. V.; Beeson, James G.; Anders, Robin F.; Richards, Jack S.; Norton, Raymond S.

    2016-01-01

    MSP2 is an intrinsically disordered protein that is abundant on the merozoite surface and essential to the parasite Plasmodium falciparum. Naturally-acquired antibody responses to MSP2 are biased towards dimorphic sequences within the central variable region of MSP2 and have been linked to naturally-acquired protection from malaria. In a phase IIb study, an MSP2-containing vaccine induced an immune response that reduced parasitemias in a strain-specific manner. A subsequent phase I study of a vaccine that contained both dimorphic forms of MSP2 induced antibodies that exhibited functional activity in vitro. We have assessed the contribution of the conserved and variable regions of MSP2 to the generation of a strain-transcending antibody response by generating MSP2 chimeras that included conserved and variable regions of the 3D7 and FC27 alleles. Robust anti-MSP2 antibody responses targeting both conserved and variable regions were generated in mice, although the fine specificity and the balance of responses to these regions differed amongst the constructs tested. We observed significant differences in antibody subclass distribution in the responses to these chimeras. Our results suggest that chimeric MSP2 antigens can elicit a broad immune response suitable for protection against different strains of P. falciparum. PMID:26865062

  12. Imperfectly synchronized states and chimera states in two interacting populations of nonlocally coupled Stuart-Landau oscillators

    Science.gov (United States)

    Premalatha, K.; Chandrasekar, V. K.; Senthilvelan, M.; Lakshmanan, M.

    2016-07-01

    We investigate the emergence of different kinds of imperfectly synchronized states and chimera states in two interacting populations of nonlocally coupled Stuart-Landau oscillators. We find that the complete synchronization in population I and existence of solitary oscillators which escape from the synchronized group in population II lead to imperfectly synchronized states for sufficiently small values of nonisochronicity parameter. Interestingly, upon increasing the strength of this parameter further there occurs an onset of mixed imperfectly synchronized states where the solitary oscillators occur from both the populations. Synchronized oscillators from both the populations are locked to a common average frequency. In both cases of imperfectly synchronized states, synchronized oscillators exhibit periodic motion while the solitary oscillators are quasiperiodic in nature. In this region, for spatially prepared initial conditions, we can observe the mixed chimera states where the coexistence of synchronized and desynchronized oscillations occur from both the populations. On the other hand, imperfectly synchronized states are not always stable, and they can drift aperiodically due to instability caused by an increase of nonisochronicity parameter. We observe that these states are robust to the introduction of frequency mismatch between the two populations.

  13. New screening software shows that most recent large 16S rRNA gene clone libraries contain chimeras.

    Science.gov (United States)

    Ashelford, Kevin E; Chuzhanova, Nadia A; Fry, John C; Jones, Antonia J; Weightman, Andrew J

    2006-09-01

    A new computer program, called Mallard, is presented for screening entire 16S rRNA gene libraries of up to 1,000 sequences for chimeras and other artifacts. Written in the Java computer language and capable of running on all major operating systems, the program provides a novel graphical approach for visualizing phylogenetic relationships among 16S rRNA gene sequences. To illustrate its use, we analyzed most of the large libraries of cloned bacterial 16S rRNA gene sequences submitted to the public repository during 2005. Defining a large library as one containing 100 or more sequences of 1,200 bases or greater, we screened 25 of the 28 libraries and found that all but three contained substantial anomalies. Overall, 543 anomalous sequences were found. The average anomaly content per clone library was 9.0%, 4% higher than that previously estimated for the public repository overall. In addition, 90.8% of anomalies had characteristic chimeric patterns, a rise of 25.4% over that found previously. One library alone was found to contain 54 chimeras, representing 45.8% of its content. These figures far exceed previous estimates of artifacts within public repositories and further highlight the urgent need for all researchers to adequately screen their libraries prior to submission. Mallard is freely available from our website at http://www.cardiff.ac.uk/biosi/research/biosoft/.

  14. Imperfectly synchronized states and chimera states in two interacting populations of nonlocally coupled Stuart-Landau oscillators.

    Science.gov (United States)

    Premalatha, K; Chandrasekar, V K; Senthilvelan, M; Lakshmanan, M

    2016-07-01

    We investigate the emergence of different kinds of imperfectly synchronized states and chimera states in two interacting populations of nonlocally coupled Stuart-Landau oscillators. We find that the complete synchronization in population I and existence of solitary oscillators which escape from the synchronized group in population II lead to imperfectly synchronized states for sufficiently small values of nonisochronicity parameter. Interestingly, upon increasing the strength of this parameter further there occurs an onset of mixed imperfectly synchronized states where the solitary oscillators occur from both the populations. Synchronized oscillators from both the populations are locked to a common average frequency. In both cases of imperfectly synchronized states, synchronized oscillators exhibit periodic motion while the solitary oscillators are quasiperiodic in nature. In this region, for spatially prepared initial conditions, we can observe the mixed chimera states where the coexistence of synchronized and desynchronized oscillations occur from both the populations. On the other hand, imperfectly synchronized states are not always stable, and they can drift aperiodically due to instability caused by an increase of nonisochronicity parameter. We observe that these states are robust to the introduction of frequency mismatch between the two populations.

  15. SCHEMA computational design of virus capsid chimeras: calibrating how genome packaging, protection, and transduction correlate with calculated structural disruption.

    Science.gov (United States)

    Ho, Michelle L; Adler, Benjamin A; Torre, Michael L; Silberg, Jonathan J; Suh, Junghae

    2013-12-20

    Adeno-associated virus (AAV) recombination can result in chimeric capsid protein subunits whose ability to assemble into an oligomeric capsid, package a genome, and transduce cells depends on the inheritance of sequence from different AAV parents. To develop quantitative design principles for guiding site-directed recombination of AAV capsids, we have examined how capsid structural perturbations predicted by the SCHEMA algorithm correlate with experimental measurements of disruption in seventeen chimeric capsid proteins. In our small chimera population, created by recombining AAV serotypes 2 and 4, we found that protection of viral genomes and cellular transduction were inversely related to calculated disruption of the capsid structure. Interestingly, however, we did not observe a correlation between genome packaging and calculated structural disruption; a majority of the chimeric capsid proteins formed at least partially assembled capsids and more than half packaged genomes, including those with the highest SCHEMA disruption. These results suggest that the sequence space accessed by recombination of divergent AAV serotypes is rich in capsid chimeras that assemble into 60-mer capsids and package viral genomes. Overall, the SCHEMA algorithm may be useful for delineating quantitative design principles to guide the creation of libraries enriched in genome-protecting virus nanoparticles that can effectively transduce cells. Such improvements to the virus design process may help advance not only gene therapy applications but also other bionanotechnologies dependent upon the development of viruses with new sequences and functions.

  16. Novel Photo-Detectors and Photo-Detector Systems

    OpenAIRE

    Danilov, M.

    2008-01-01

    Recent developments in photo-detectors and photo-detector systems are reviewed. The main emphasis is made on Silicon Photo-Multipliers (SiPM) - novel and very attractive photo-detectors. Their main features are described. Properties of detectors manufactured by different producers are compared. Different applications are discussed including calorimeters, muon detection, tracking, Cherenkov light detection, and time of flight measurements.

  17. Simplified phase detector

    Science.gov (United States)

    Hershey, L. M.

    1979-01-01

    Tanlick sine-wave phase detector gives dc output voltage nearly proportional to phase difference between oscillator signal and reference signal. Device may be used for systems in which signal-to-noise ratio is high.

  18. The CLIC Detector Concept

    CERN Document Server

    Pitters, Florian Michael

    2016-01-01

    CLIC is a concept for a future linear collider that would provide e+e- collisions at up to 3 TeV. The physics aims require a detector system with excellent jet energy and track momentum resolution, highly efficient flavour-tagging and lepton identification capabilities, full geometrical coverage extending to low polar angles and timing information in the order of nanoseconds to reject beam-induced background. To deal with those requirements, an extensive R&D programme is in place to overcome current technological limits. The CLIC detector concept includes a low-mass all-silicon vertex and tracking detector system and fine-grained calorimeters designed for particle flow analysis techniques, surrounded by a 4 T solenoid magnet. An overview of the requirements and design optimisations for the CLIC detector concept is presented.

  19. Multiple detectors "Influence Method".

    Science.gov (United States)

    Rios, I J; Mayer, R E

    2016-05-01

    The "Influence Method" is conceived for the absolute determination of a nuclear particle flux in the absence of known detector efficiency and without the need to register coincidences of any kind. This method exploits the influence of the presence of one detector in the count rate of another detector, when they are placed one behind the other and define statistical estimators for the absolute number of incident particles and for the efficiency (Rios and Mayer, 2015a). Its detailed mathematical description was recently published (Rios and Mayer, 2015b) and its practical implementation in the measurement of a moderated neutron flux arising from an isotopic neutron source was exemplified in (Rios and Mayer, 2016). With the objective of further reducing the measurement uncertainties, in this article we extend the method for the case of multiple detectors placed one behind the other. The new estimators for the number of particles and the detection efficiency are herein derived. PMID:26943904

  20. The Advanced LIGO Detectors

    Science.gov (United States)

    Fritschel, Peter

    2016-03-01

    After decades of development, the Advanced LIGO gravitational wave detectors are now operating, and they completed their first observational run in early 2016. Advanced LIGO consists of two 4-km scale interferometric detectors located at separate sites in the US. The first year of detector commissioning that led to the first observation run produced instruments that have several times better sensitivity to gravitational-wave strain than previous instruments. At their final design sensitivity, the detectors will be another factor of 2-3x more sensitive than current performance. This talk will cover the design of Advanced LIGO, explain how the sensitivity improvements have been achieved, and lay out the path to reaching final design sensitivity.