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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. The Diogene 4 pi detector at Saturne

    Science.gov (United States)

    Alard, J. P.; Arnold, J.; Augerat, J.; Babinet, R.; Bastid, N.; Brochard, F.; Costilhes, J. P.; Crouau, M.; De Marco, N.; Drouet, M.; Dupieux, P.; Fanet, H.; Fodor, Z.; Fraysse, L.; Girard, J.; Gorodetzky, P.; Gosset, J.; Laspalles, C.; Lemaire, M. C.; L'Hote, D.; Lucas, B.; Montarou, G.; Papineau, A.; Parizet, M. J.; Schimmerling, W.

    1987-01-01

    Diogene, an electronic 4 pi detector, has been built and installed at the Saturne synchrotron in Saclay. The forward angular range (0 degree-6 degrees) is covered by 48 time-of-flight scintillator telescopes that provide charge identification. The trajectories of fragments emitted at larger angles are recorded in a cylindrical 0.4-m3 Pictorial Drift Chamber (PDC) surrounding the target. The PDC is inside a 1-T magnetic field; the axis of the PDC cylinder and the magnetic field are parallel to the beam. Good identification has been obtained for both positive and negative pi mesons and for hydrogen and helium isotopes. Multiplicities in relativistic nucleus-nucleus reactions up to 40 have been detected, limited mainly by the present electronics.

  3. Fast 4$\\pi$ track reconstruction in nuclear emulsion detectors based on GPU technology

    CERN Document Server

    Ariga, A

    2013-01-01

    Fast 4$\\pi$ solid angle particle track recognition has been a challenge in particle physics for a long time, especially in using nuclear emulsion detectors. The recent advances in computing technology opened the way for its realization. A fast 4$\\pi$ solid angle particle track reconstruction based on GPU technology combined with a multithread programming is reported here with a detailed comparison between GPU-based and CPU-based programming. A 60 times faster processing of 3D emulsion detector data, corresponding to processing of 15 cm$^2$ emulsion surface scanned per hour, has been achieved by GPUs with an excellent tracking performance.

  4. Coincidence system for standardization of radionuclides using a 4pi plastic scintillator detector.

    Science.gov (United States)

    Baccarelli, Aída M; Dias, Mauro S; Koskinas, Marina F

    2003-02-01

    A coincidence system using a plastic scintillator detector in 4pi geometry has been developed and applied for the standardization of radionuclides. The scintillator shape and dimensions have been optimized for maximum charge particle detection efficiency, while keeping background low and a nearly constant gamma-ray efficiency for different points from the radioactive source. The gamma-ray events were measured with a NaI(Tl) scintillation counter. The electronic system for processing pulses consisted of logic gates and delay modules feeding a time-to-amplitude converter with output to a multichannel analyzer. The alpha detection efficiency measured with 241Am was around 95% and the beta detection efficiency for 60Co was around 67%. Activity measurements of 241Am and 60Co were performed and the results showed good agreement when compared with a conventional coincidence system employing a 4pi proportional counter.

  5. Coincidence system for standardization of radionuclides using a 4 pi plastic scintillator detector

    CERN Document Server

    Baccarelli, A M; Koskinas, M F

    2003-01-01

    A coincidence system using a plastic scintillator detector in 4 pi geometry has been developed and applied for the standardization of radionuclides. The scintillator shape and dimensions have been optimized for maximum charge particle detection efficiency, while keeping background low and a nearly constant gamma-ray efficiency for different points from the radioactive source. The gamma-ray events were measured with a NaI(Tl) scintillation counter. The electronic system for processing pulses consisted of logic gates and delay modules feeding a time-to-amplitude converter with output to a multichannel analyzer. The alpha detection efficiency measured with sup 2 sup 4 sup 1 Am was around 95% and the beta detection efficiency for sup 6 sup 0 Co was around 67%. Activity measurements of sup 2 sup 4 sup 1 Am and sup 6 sup 0 Co were performed and the results showed good agreement when compared with a conventional coincidence system employing a 4 pi proportional counter.

  6. 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.

  7. 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.

  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. Feasibility study of measuring CP symmetry violation via eta->4pi decay using WASA-at-COSY detector

    CERN Document Server

    Bednarski, Tomasz

    2011-01-01

    It is known that the Standard Model does not describe all phenomena related to subatomic particles. This thesis presents feasibility studies of the measurement of eta meson decay using WASA-at-COSY detector which tests predictions of the Standard Model. The aim of this thesis is to estimate the time of measurement for which the current branching ratio limit of eta -> 4pi0 decay can be improved. In order to estimate the time of measurement Monte Carlo simulations were performed. Kinematics of the pp -> ppeta -> pp4pi0 -> pp8gamma reactions were simulated using PLUTO program. Next, by means of the GEANT3 program the response of the WASA-at-COSY detector was simulated for each particle. Received signals were analysed in RootSorter software package based on ROOT. Studies of the reaction with many gamma quanta in the exit channel required the investigation of WASA-at-COSY calorimeter functioning. Tests of a cluster building algorithm with emphasis on merging and splitting of detected signals were done. The obtaine...

  10. 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...

  11. $\\bar{p}$-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 ...

  12. A highly segmented. Delta. E-time-of-flight wall as forward detector of the 4. pi. -system for charged particles at the SIS/ESR accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Gobbi, A.; Augustinski, G.; Bock, R.; Charity, R.J.; Fan, Z.G.; Freifelder, R.; Grigorian, Y.; Hildenbrand, K.D.; Jeong, S.C.; Marquardt, M.; Reisdorf, W.; Schuell, D.; Sodan, U.; Tanaka, M.H.; Teh, K.M.; Weinert, J.; Wessels, J.P. (Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)); Alard, J.P.; Bastid, N.; Boussange, S.; Crouau, M.; Daudon, F.; Dupieux, P.; Fayard, C.; Fraysse, L.; Jorio, M.; Mayade, S.; Mo

    1992-05-01

    At the SIS/ESR accelerator facility at GSI in Darmstadt the 4{pi}-detector system FOPI is under construction at present. It is designed for the investigation of central collisions of heavy ions in the energy range up to 2xA GeV. As phase I of this detector a forward wall has been built and used in various experiments. It comprises a total number of 764 scintillators with an additional shell of 188 thin {Delta}E-detectors in front of it and covers the full azimuth of the polar angles from 1{sup 0} to 30{sup 0}. The velocity and the nuclear charge of the fragments are determined by a combined time of flight and {Delta}E measurement. (orig.).

  13. A highly-segmented [Delta]E-time-of-flight wall as forward detector of the 4[pi]-system for charged particles at the SIS/ESR accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Gobbi, A.; Augustinski, G.; Bock, R.; Charity, R.J.; Fan, Z.G.; Freifelder, R.; Hildenbrand, K.D.; Jeong, S.C.; Marquardt, M.; Reisdorf, W.; Schuell, D.; Sodan, U.; Tanaka, M.H.; Teh, K.M.; Weinert, J.; Wessels, J.P. (Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany)); Alard, J.P.; Bastid, N.; Boussange, S.; Crouau, M.; Daudon, F.; Dupieux, P.; Fayard, C.; Fraysse, L.; Jorio, M.; Mayade, S.; Montarou, G.; Montbel, I.; Morel, P.; Sahuc, E.; Savinel, G.; Vincent, D. (Lab. de Physique Corpusculaire, Univ. Clermont-Ferrand, Aubiere (France)); Basrak, Z.; Caplar, R.; Cindro, N.; Hoelbling, S. (Rudjer Boskovic Inst., Zagreb (Croatia)); Belayev, I.M.; Frolov, S.; Korchagin, Y.; Lebedev, A.; Smolyankin, S.; Zhilin, A.V. (Inst. for Experimental and Theoretical Physics, Moscow (Russia)); Blaich, T. (Inst. fuer Kernchemie, Univ. Mainz (Germany)); Boccaccio, P. (Ist. Nazionale di Fisica Nucleare, Lab. Nazionali Legnaro, Padua (Italy)); Buta, A.; Legrand, I.; Moisa, D.; Petrovici, M

    1993-01-01

    At the SIS/ESR accelerator facility at GSI in Darmstadt the 4[pi]-detector system FOPI is under construction at present. It is designed for the investigation of central collisions of heavy ions in the energy range up to 2 A GeV. As phase I of this detector a forward wall has been built and used in various experiments. It comprizes a total number of 764 scintillators with an additional shell of 188 thin [Delta]E-detectors in front of it and covers the full azimuth of the polar angles from 1deg to 30deg. The velocity and the nuclear charge of the fragments are determined by a combined time-of-flight and [Delta]E measurements. (orig.).

  14. 4 pi β-spectrometer with Li-Si counters

    DEFF Research Database (Denmark)

    Andersen, Verner; Christensen, Carl Jørgen

    1968-01-01

    Spectrometer has been developed; provided with solid-state detectors, it has resolution of 2% at 1 Mev; because of 4 pi-geometry it is well suited for absolute measurements and for measurement of conversion coefficients. (14005)...

  15. 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...

  16. 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.

  17. 4Pi-SHG imaging of mammalian myofibrillar structures

    Science.gov (United States)

    Vogel, Martin; Hahn, Dorothea; Schürmann, Sebastian; Lang, Marion; Wegner, Frederic v.; Friedrich, Oliver; Engelhardt, Johann; Hell, Stefan W.; Fink, Rainer H.

    2006-02-01

    Intrinsic Second Harmonic Generation (SHG) signals obtained from the motor protein myosin are of particular interest for 3D-imaging of living muscle cells. In addition, the new and powerful tool of 4Pi microscopy allows to markedly enhance the optical resolution of microscopy as well as the sensitivity for small objects because of the high peak intensities due to the interference pattern created in the focus. In the present study, we report, to our knowledge for the first time, measurements of intrinsic SHG signals under 4Pi conditions of type A. These measurements on mammalian myofibrilar structures are combined with very high resolution 4Pi fluorescence data obtained from the same preparations. We have chosen myofibrillar preparations of isolated mammalian muscle fibers as they (i) possess a regular repetitive pattern of actin and myosin filaments within sarcomers 2 to 3 μm in length, (ii) consist of single myofibrils of small total diameter of approximately 1 μm and (iii) are ideally suited to study the biomedically important process of force generation via calcium regulated motor protein interactions. Myofibrillar preparations were obtained from murine skeletal and heart muscle by using a combined chemical and mechanical fractionation1 (Both et al. 2004, JBO 9(5):882-892). BODIPY FL phallacidin has been used to fluorescently label the actin filaments. The experiments were carried out with a Leica SP2 multi photon microscope modified for 4Pi measurements using a Ti:Sa laser tuned to 850-900 nm. SHG as well as fluorescence photons were detected confocally by a counting APD detector. The approach taken our study provides new 3D-data for the analysis and simulation of the important process of excitation-contraction coupling under normal physiological as well as under pathophysiological conditions.

  18. A 4-PI DILEPTON SPECTROMETER - PEPSI

    NARCIS (Netherlands)

    BUDA, A; BACELAR, JCS; BALANDA, A; VANKLINKEN, J; SUJKOWSKI, Z; VANDERWOUDE, A

    1993-01-01

    A novel positron-electron pair spectroscopy instrument (PEPSI) was designed to measure transitions in the energy region 10-40 MeV. It consists of Nd2Fe14B permanent magnets forming a compact 4 pi magnetic filter consisting of 12 positron and 20 electron mini-orange-like spectrometers. The response f

  19. 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.

  20. Is Fundamental Particle Mass 4-pi Quantized?

    Directory of Open Access Journals (Sweden)

    Stone R. A. Jr.

    2010-01-01

    Full Text Available The Standard Model lacks an explanation for the specific mass values of the fundamental particles. This is to report that a single spin quantized mass formula can produce the masses of the proton, the $W$, and the three electron generations. The $4pi$ mass quantization pattern limits the electron generations to three, while the particle's generational property is one of the components of the proposed intra-particle quantization process. Although the developed relationships are presently phenomenological, so was Bohr's atomic quantization proposal that lead to quantum mechanics.

  1. A 4[pi] dilepton spectrometer: PEPSI

    Energy Technology Data Exchange (ETDEWEB)

    Buda, A. (Kernfysisch Versneller Inst., Groningen (Netherlands)); Bacelar, J.C.S. (Kernfysisch Versneller Inst., Groningen (Netherlands)); Balanda, A. (Kernfysisch Versneller Inst., Groningen (Netherlands)); Klinken, J. van (Kernfysisch Versneller Inst., Groningen (Netherlands)); Sujkowski, Z. (Kernfysisch Versneller Inst., Groningen (Netherlands)); Woude, A. van der (Kernfysisch Versneller Inst., Groningen (Netherlands))

    1993-11-01

    A novel positron-electron pair spectroscopy instrument (PEPSI) was designed to measure transitions in the energy region 10-40 MeV. It consists of Nd[sub 2]Fe[sub 14]B permanent magnets forming a compact 4[pi] magnetic filter consisting of 12 positron and 20 electron mini-orange-like spectrometers. The response function of PEPSI has been measured with mono-energetic beams of electrons from 5 to 20 MeV. The PEPSI spectrometer was used for measuring the internal pair conversion coefficient ([alpha][sub [pi

  2. 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...

  3. Revealing Intermittency in Nuclear Multifragmentation with 4$\\PI$ Detectors

    CERN Document Server

    Baldo, Marcello; Rapisarda, A

    1993-01-01

    The distortion on the intermittency signal, due to detection efficiency and to the presence of pre--equilibrium emitted particles, is studied in a schematic model of nuclear multi- fragmentation. The source of the intermittency signal is modeled with a percolating system. The efficiency is schematized by a simple function of the fragment size, and the presence of pre--equilibrium particles is simulated by an additional non--critical fragment source. No selection on the events is considered, and therefore all events are used to calculate the moments. It is found that, despite the absence of event selection, the intermittency signal is quite resistant to the distortion due to the apparatus efficiency, while the inclusion of pre--equilibrium particles in the moment calculation can substantially reduce the strength of the signal. Pre--equilibrium particles should be therefore carefully separated from the rest of the detected fragments, before the intermittency analysis on experimental charge or mass distributions...

  4. Smallest chimera states

    Science.gov (United States)

    Maistrenko, Yuri; Brezetsky, Serhiy; Jaros, Patrycja; Levchenko, Roman; Kapitaniak, Tomasz

    2017-01-01

    We demonstrate that chimera behavior can be observed in small networks consisting of three identical oscillators, with mutual all-to-all coupling. Three different types of chimeras, characterized by the coexistence of two coherent oscillators and one incoherent oscillator (i.e., rotating with another frequency) have been identified, where the oscillators show periodic (two types) and chaotic (one type) behaviors. Typical bifurcations at the transitions from full synchronization to chimera states and between different types of chimeras have been described. Parameter regions for the chimera states are obtained in the form of Arnold tongues, issued from a singular parameter point. Our analysis suggests that chimera states can be observed in small networks relevant to various real-world systems.

  5. Calibration of the 4pi gamma-ray spectrometer using a new numerical simulation approach.

    Science.gov (United States)

    Nafee, Sherif S; Badawi, Mohamed S; Abdel-Moneim, Ali M; Mahmoud, Seham A

    2010-09-01

    The 4pi gamma-counting system is well suited for analysis of small environmental samples of low activity because it combines advantages of the low background and the high detection efficiency due to the 4pi solid angle. A new numerical simulation approach is proposed for the HPGe well-type detector geometry to calculate the full-energy peak and the total efficiencies, as well as to correct for the coincidence summing effect. This method depends on a calculation of the solid angle subtended by the source to the detector at the point of entrance, (Abbas, 2006a). The calculations are carried out for non-axial point and cylindrical sources inside the detector cavity. Attenuation of photons within the source itself (self-attenuation), the source container, the detector's end-cap and the detector's dead layer materials is also taken into account. In the Belgium Nuclear Research Center, low-activity aqueous solutions of (60)Co and (88)Y in small vials are routinely used to calibrate a gamma-ray p-type well HPGe detector in the 60-1836keV energy range. Efficiency values measured under such conditions are in good agreement with those obtained by the numerical simulation.

  6. Search for the CP forbidden decay eta-->4pi(0)

    Science.gov (United States)

    Prakhov; Tippens; Allgower; Bekrenev; Berger; Briscoe; Clajus; Comfort; Craig; Grosnick; Huber; Isenhower; Knecht; Koetke; Koulbardis; Kozlenko; Kruglov; Kycia; Lolos; Lopatin; Manley; Marusic; Manweiler; McDonald; Nefkens; Olmsted

    2000-05-22

    We report the first determination of the upper limit for the branching ratio of the CP forbidden decay eta-->4pi(0). No events were observed in a sample of 3.0x10(7) eta decays. The experiment was performed with the Crystal Ball multiphoton spectrometer installed in a separated pi(-) beam at the AGS (Alternating Gradient Synchrotron). At the 90% confidence limit, B(eta-->4pi(0))

  7. 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.

  8. 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)

  9. 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...

  10. 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.

  11. 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).

  12. 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.

  13. Emergence of multicluster chimera states.

    Science.gov (United States)

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

    2015-09-09

    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.

  14. 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.

  15. Vertex and Propagator in $\\Phi^{4}$ Theory from 4PI Effective Action in Two Dimensions

    CERN Document Server

    Carrington, M E

    2012-01-01

    A set of self-consistent nonlinear integral equations for the four-point vertex and the propagator are derived from the 4-loop 4PI effective action for scalar field theories. This set of integral equations are solved in two dimensions through numerical lattice calculations. We compare the calculated results with those of perturbation theories. We find that the 4PI calculations are well consistent with the perturbation ones in perturbative regions. Non-perturbative results are also obtained in the 4PI formalism when the interacting strength becomes large. Furthermore, the full-momentum dependence of the four-point vertex is easily obtained in the 4PI effective action theories.

  16. 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.

  17. 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.

  18. Chimera and chimera-like states in populations of nonlocally coupled homogeneous and heterogeneous chemical oscillators

    Science.gov (United States)

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

    2016-09-01

    Chimera and chimera-like states are characterized in populations of photochemically coupled Belousov-Zhabotinsky (BZ) oscillators. Simple chimeras and chimera states with multiple and traveling phase clusters, phase-slip behavior, and chimera-like states with phase waves are described. Simulations with a realistic model of the discrete BZ system of populations of homogeneous and heterogeneous oscillators are compared with each other and with experimental behavior.

  19. Constraining QGP properties with CHIMERA

    Science.gov (United States)

    Garishvili, Irakli; Abelev, Betty; Cheng, Michael; Glenn, Andrew; Soltz, Ron

    2011-10-01

    Understanding essential properties of strongly interacting matter is arguably the most important goal of the relativistic heavy-ion programs both at RHIC and the LHC. In particular, constraining observables such as ratio of shear viscosity to entropy density, η/s, initial temperature, Tinit, and energy density is of critical importance. For this purpose we have developed CHIMERA, Comprehensive Heavy Ion Model Reporting and Evaluation Algorithm. CHIMERA is designed to facilitate global statistical comparison of results from our multi-stage hydrodynamics/hadron cascade model of heavy ion collisions to the key soft observables (HBT, elliptic flow, spectra) measured at RHIC and the LHC. Within this framework the data representing multiple different measurements from different experiments are compiled into single format. One of the unique features of CHIMERA is, that in addition to taking into account statistical errors, it also treats different types of systematic uncertainties. The hydrodynamics/hadron cascade model used in the framework incorporates different initial state conditions, pre-equilibrium flow, the UVH2+1 viscous hydro model, Cooper-Frye freezeout, and the UrQMD hadronic cascade model. The sensitivity of the observables to the equation of state (EoS) is explored using several EoS's in the hydrodynamic evolution. The latest results from CHIMERA, including data from the LHC, will be presented.

  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. 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.

  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. Search for the CP forbidden decay {nu} {yields} 4{pi}{sup 0}.

    Energy Technology Data Exchange (ETDEWEB)

    Prakhov, S.; Tippens, W. B.; Allgower, C.; Bekrenev, V.; Berger, E.; Spinka, H.; High Energy Physics; Univ. of California; Petersburg Nuclear Physics Inst.

    2000-05-22

    We report the first determination of the upper limit for the branching ratio of the CP forbidden decay {eta}{yields}4{pi}{sup 0}. No events were observed in a sample of 3.0 x 10{sup 7} {eta} decays. The experiment was performed with the Crystal Ball multiphoton spectrometer installed in a separated {pi}{sup -} beam at the AGS (Alternating Gradient Synchrotron). At the 90% confidence limit, B({eta}{yields}4{pi}{sup 0}){<=}6.9x10{sup -7}.

  4. Search for the CP Forbidden Decay {eta}{yields}4{pi}{sup 0}

    Energy Technology Data Exchange (ETDEWEB)

    Prakhov, S. [University of California, Los Angeles, Los Angeles, California 90095-1547 (United States); Tippens, W. B. [University of California, Los Angeles, Los Angeles, California 90095-1547 (United States); Allgower, C. [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Bekrenev, V. [Petersburg Nuclear Physics Institute, Gatchina, Leningrad District, Russia 188350 (Russian Federation); Berger, E. [University of California, Los Angeles, Los Angeles, California 90095-1547 (United States); Briscoe, W. J. [George Washington University, Washington, D.C. 20052 (United States); Clajus, M. [University of California, Los Angeles, Los Angeles, California 90095-1547 (United States); Comfort, J. R. [Arizona State University, Tempe, Arizona 85287-1504 (United States); Craig, K. [Arizona State University, Tempe, Arizona 85287-1504 (United States); Grosnick, D. [Valparaiso University, Valparaiso, Indiana 46383 (United States)] (and others)

    2000-05-22

    We report the first determination of the upper limit for the branching ratio of the CP forbidden decay {eta}{yields}4{pi}{sup 0} . No events were observed in a sample of 3.0x10{sup 7} {eta} decays. The experiment was performed with the Crystal Ball multiphoton spectrometer installed in a separated {pi}{sup -} beam at the AGS (Alternating Gradient Synchrotron). At the 90% confidence limit, B({eta}{yields}4{pi}{sup 0}){<=} 6.9x10{sup -7} . (c) 2000 The American Physical Society.

  5. 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...

  6. 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)

  7. 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

  8. The smallest chimera state for coupled pendula

    Science.gov (United States)

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

    2016-10-01

    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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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...

  14. 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.

  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.

  16. 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.

  17. Chimera states in mechanical oscillator networks

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...

  18. 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.

  19. Phase filter enhanced STED-4Pi fluorescence microscopy: theory and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Dyba, M; Keller, J; Hell, S W [Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, D-37070 Goettingen (Germany)

    2005-05-01

    We study the point-spread and optical transfer-function (OTF) of a stimulated emission depletion (STED)-4Pi fluorescence microscope that provides diffraction unlimited resolution along the optic axis. Our calculations take into account the orientation of the linear transition dipole moment of the fluorescent molecules with respect to that of the focal field. We demonstrate a subdiffraction axial resolution of 44-48 nm for water-immersion lenses, corresponding to a 7-8-fold expansion of the OTF beyond the diffraction barrier of a single lens confocal microscope, which is in excellent agreement with theoretical predictions for the conditions applied. Furthermore, we study phase modifications of the wavefront of the stimulating beam that strengthen weakly transferred frequencies within the OTF support. The enlarged bandwidth enables the separation of objects at 76 nm axial distance.

  20. 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.

  1. A Discontinuous Galerkin Chimera Overset Solver

    Science.gov (United States)

    Galbraith, Marshall Christopher

    This work summarizes the development of an accurate, efficient, and flexible Computational Fluid Dynamics computer code that is an improvement relative to the state of the art. The improved accuracy and efficiency is obtained by using a high-order discontinuous Galerkin (DG) discretization scheme. In order to maximize the computational efficiency, quadrature-free integration and numerical integration optimized as matrix-vector multiplications is employed and implemented through a pre-processor (PyDG). Using the PyDG pre-processor, a C++ polynomial library has been developed that uses overloaded operators to design an efficient Domain Specific Language (DSL) that allows expressions involving polynomials to be written as if they are scalars. The DSL, which makes the syntax of computer code legible and intuitive, promotes maintainability of the software and simplifies the development of additional capabilities. The flexibility of the code is achieved by combining the DG scheme with the Chimera overset method. The Chimera overset method produces solutions on a set of overlapping grids that communicate through an exchange of data on grid boundaries (known as artificial boundaries). Finite volume and finite difference discretizations use fringe points, which are layers of points on the artificial boundaries, to maintain the interior stencil on artificial boundaries. The fringe points receive solution values interpolated from overset grids. Proper interpolation requires fringe points to be contained in overset grids. Insufficient overlap must be corrected by modifying the grid system. The Chimera scheme can also exclude regions of grids that lie outside the computational domain; a process commonly known as hole cutting. The Chimera overset method has traditionally enabled the use of high-order finite difference and finite volume approaches such as WENO and compact differencing schemes, which require structured meshes, for modeling fluid flow associated with complex

  2. Comprehensive measurements in 4 {pi} geometry for radio-active samples having a low {beta}-activity (1962); Ensemble de mesure'en geometrie 4 {pi} pour echantillons radioactifs de faible activite {beta} (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Colomer, J.; Valentin, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The realisation is described of a comprehensive measurement system having low background noise and, as well as a lead-wall protection, an electronic protection made up of a plastic scintillator placed in anticoincidence with the 4 {pi} counter used for making the measurements. The apparatus is described and its performance discussed. (authors) [French] Realisation d'un ensemble de mesures ayant un faible bruit de fond en utilisant en plus d'une protection par murs de Pb, une protection electronique constituee par un scintillateur plastique mis en ainticoincidence avec le compteur 4 {pi} utilise pour faire les mesures. L'appareillage est decrit et ses performances discutees. (auteurs)

  3. 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...

  4. 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...... peptidomimetic backbone construct for biologically active ligands....

  5. 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.

  6. 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...

  7. 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)

  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. 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.

  10. 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)

  11. 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)

  12. 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)

  13. A 4 pi β-spectrometer with Li-Si counters

    DEFF Research Database (Denmark)

    Andersen, Verner

    1968-01-01

    A 4πβ-spectrometer provided with solid-state detectors (Abstr. A24730, b15517 of 1968) has been developed. With the first stage of the preamplifiers cooled, a resolution of better than 0.8% at 1 MeV has been obtained...

  14. Assessing reprogramming by chimera formation and tetraploid complementation.

    Science.gov (United States)

    Li, Xin; Xia, Bao-long; Li, Wei; Zhou, Qi

    2015-01-01

    Pluripotent stem cells can be evaluated by pluripotent markers expression, embryoid body aggregation, teratoma formation, chimera contribution and even more, tetraploid complementation. Whether iPS cells in general are functionally equivalent to normal ESCs is difficult to establish. Here, we present the detailed procedure for chimera formation and tetraploid complementation, the most stringent criterion, to assessing pluripotency.

  15. Chimera patterns in the Kuramoto-Battogtokh model

    Science.gov (United States)

    Smirnov, Lev; Osipov, Grigory; Pikovsky, Arkady

    2017-02-01

    Kuramoto and Battogtokh (2002 Nonlinear Phenom. Complex Syst. 5 380) discovered chimera states represented by stable coexisting synchrony and asynchrony domains in a lattice of coupled oscillators. After a reformulation in terms of a local order parameter, the problem can be reduced to partial differential equations. We find uniformly rotating, spatially periodic chimera patterns as solutions of a reversible ordinary differential equation, and demonstrate a plethora of such states. In the limit of neutral coupling they reduce to analytical solutions in the form of one- and two-point chimera patterns as well as localized chimera solitons. Patterns at weakly attracting coupling are characterized by virtue of a perturbative approach. Stability analysis reveals that only the simplest chimeras with one synchronous region are stable.

  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. 4 pi direction sensitive gamma imager with RENA-3 readout ASIC

    Science.gov (United States)

    Du, Yanfeng; Li, Wen; Yanoff, Brian; Gordon, Jeffrey; Castleberry, Donald

    2007-09-01

    A 4π direction-sensitive gamma imager is presented, using a 1 cm 3 3D CZT detector from Yinnel Tech and the RENA-3 readout ASIC from NOVA R&D. The measured readout system electronic noise is around 4-5 keV FWHM for all anode channels. The measured timing resolution between two channels within a single ASIC is around 10 ns and the resolution is 30 ns between two separate ASIC chips. After 3D material non-uniformity and charge trapping corrections, the measured single-pixel-event energy resolution is around 1% for Cs-137 at 662 keV using a 1 cm 3 CZT detector from Yinnel Tech with an 8 x 8 anode pixel array at 1.15 mm pitch. The energy resolution for two pixel events is 2.9%. A 10 uCi Cs-137 point source was moved around the detector to test the image reconstruction algorithms and demonstrate the source direction detection capability. Accurate source locations were reconstructed with around 200 two-pixel events within a total energy window +/-10 keV around the 662 keV full energy peak. The angular resolution FWHM at four of the five positions tested was between 0.05-0.07 steradians.

  18. 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.

  19. 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.

  20. 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...

  1. 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.

  2. 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...

  3. General description and first results with the ORIS-LMRI 4 {pi} {gamma} metering chamber; Descripcion general y primeros resultados con la camara 4 {pi} {gamma} metrologica ORIS-LMRI

    Energy Technology Data Exchange (ETDEWEB)

    Tejera R, A.; Becerril V, A.; Cortes P, A

    1990-04-15

    A problem that present the ionization chambers is that the response for the radiation is global, that is to say that it cannot discriminate against selectively the relating responses at different energies, if these impact simultaneously in the active volume. This is a reason to calibrate the chambers, if is possible, with gamma monoenergetic emitting and by average calculations to complete the response curve with gamma emitting of well-known yields. To obtain the calibration coefficients and may used them, it is necessary that so much the standardized radioisotopes as the solutions by calibrating, are contained in vessels with the same geometry and the same quantity. In the exposed case, pattern solutions of 5 ml were used contained in glass cruets of 10 ml. The problem solutions are contained in same cruets to those of the patterns. The first results obtained with the ORIS-LMRI 4 {pi} {gamma} metering chamber are presented. (Author)

  4. 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)

  5. Tools for integrated sequence-structure analysis with UCSF Chimera

    Directory of Open Access Journals (Sweden)

    Huang Conrad C

    2006-07-01

    Full Text Available Abstract Background Comparing related structures and viewing the structures in the context of sequence alignments are important tasks in protein structure-function research. While many programs exist for individual aspects of such work, there is a need for interactive visualization tools that: (a provide a deep integration of sequence and structure, far beyond mapping where a sequence region falls in the structure and vice versa; (b facilitate changing data of one type based on the other (for example, using only sequence-conserved residues to match structures, or adjusting a sequence alignment based on spatial fit; (c can be used with a researcher's own data, including arbitrary sequence alignments and annotations, closely or distantly related sets of proteins, etc.; and (d interoperate with each other and with a full complement of molecular graphics features. We describe enhancements to UCSF Chimera to achieve these goals. Results The molecular graphics program UCSF Chimera includes a suite of tools for interactive analyses of sequences and structures. Structures automatically associate with sequences in imported alignments, allowing many kinds of crosstalk. A novel method is provided to superimpose structures in the absence of a pre-existing sequence alignment. The method uses both sequence and secondary structure, and can match even structures with very low sequence identity. Another tool constructs structure-based sequence alignments from superpositions of two or more proteins. Chimera is designed to be extensible, and mechanisms for incorporating user-specific data without Chimera code development are also provided. Conclusion The tools described here apply to many problems involving comparison and analysis of protein structures and their sequences. Chimera includes complete documentation and is intended for use by a wide range of scientists, not just those in the computational disciplines. UCSF Chimera is free for non-commercial use and is

  6. Modeling Quark Gluon Plasma Using CHIMERA

    Science.gov (United States)

    Abelev, Betty

    2011-09-01

    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 (Tinit), presence or absence of initial flow, viscosity over entropy density (η/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. χ2/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 with parameters that are difficult to obtain experimentally, but are crucial to understanding of the matter produced.

  7. 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...

  8. 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.

  9. 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....

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Chimera states in uncoupled neurons induced by a multilayer structure

    CERN Document Server

    Majhi, Soumen; Ghosh, Dibakar

    2016-01-01

    Spatial coexistence of coherent and incoherent dynamics in network of coupled oscillators is called a chimera state. We study such chimera states in a network of neurons without any direct interactions but connected through another medium of neurons, forming a multilayer structure. The upper layer is thus made up of uncoupled neurons and the lower layer plays the role of a medium through which the neurons in the upper layer share information among each other. Hindmarsh-Rose neurons with square wave bursting dynamics are considered as nodes in both layers. In addition, we also discuss the existence of chimera states in presence of inter layer heterogeneity. The neurons in the bottom layer are globally connected through electrical synapses, while across the two layers chemical synapses are formed. According to our research, the competing effects of these two types of synapses can lead to chimera states in the upper layer of uncoupled neurons. Remarkably, we find a density-dependent threshold for the emergence o...

  16. 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 ±π2 (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.

  17. 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.

  18. 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

  19. 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

  20. Particle Identification in the NIMROD-ISiS Detector Array

    CERN Document Server

    Wuenschel, S; May, L W; Wada, R; Yennello, S J

    2009-01-01

    Interest in the influence of the neutron-to-proton (N/Z) ratio on multifragmenting nuclei has demanded an improvement in the capabilities of multi-detector arrays as well as the companion analysis methods. The particle identification method used in the NIMROD-ISiS 4 $\\pi$ array is described. Performance of the detectors and the analysis method are presented for the reaction of 86Kr+64Ni at 35MeV/u.

  1. Chimera regimes in a ring of oscillators with local nonlinear interaction

    Science.gov (United States)

    Shepelev, Igor A.; Zakharova, Anna; Vadivasova, Tatiana E.

    2017-03-01

    One of important problems concerning chimera states is the conditions of their existence and stability. Until now, it was assumed that chimeras could arise only in ensembles with nonlocal character of interactions. However, this assumption is not exactly right. In some special cases chimeras can be realized for local type of coupling [1-3]. We propose a simple model of ensemble with local coupling when chimeras are realized. This model is a ring of linear oscillators with the local nonlinear unidirectional interaction. Chimera structures in the ring are found using computer simulations for wide area of values of parameters. Diagram of the regimes on plane of control parameters is plotted and scenario of chimera destruction are studied when the parameters are changed.

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

    OpenAIRE

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

    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 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. W...

  3. 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.

  4. Chimera states and the interplay between initial conditions and non-local coupling

    Science.gov (United States)

    Kalle, Peter; Sawicki, Jakub; Zakharova, Anna; Schöll, Eckehard

    2017-03-01

    Chimera states are complex spatio-temporal patterns that consist of coexisting domains of coherent and incoherent dynamics. We study chimera states in a network of non-locally coupled Stuart-Landau oscillators. We investigate the impact of initial conditions in combination with non-local coupling. Based on an analytical argument, we show how the coupling phase and the coupling strength are linked to the occurrence of chimera states, flipped profiles of the mean phase velocity, and the transition from a phase- to an amplitude-mediated chimera state.

  5. 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...

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

    Science.gov (United States)

    Botha, André E

    2016-07-04

    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.

  7. Digital coincidence counting (DCC) and its use in the corrections for out-of-channel gamma events in 4pi beta-gamma coincidence counting.

    Science.gov (United States)

    Keightle, J D; Watt, G C

    2002-01-01

    The digital coincidence counting system developed by NPL and ANSTO is briefly described along with its benefits in the data collection and processing for the 4pi beta-gamma coincidence counting technique of radionuclide standardization. One of these benefits is the automatic detection of and correction for out-of-channel coincidences in the Computer Discrimination method. Where the criteria for the use of the Cox-Isham/Smith correction formulae for dead times and resolving times are not met, a generalized approximation based on the work of Campion is suggested.

  8. A parallel plate avalanche detector system for the localization of relativistic heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Burgei, R.; Demoulins, M.; Cavata, C.; Fanet, H.; Gosset, J.; Le Merdy, A.; L' Hote, D.; Lucas, B.; Lugol, J.C.; Poitou, J.; Valette, O. (CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Physique Nucleaire); Lemaire, M.C. (Institut National de Physique Nucleaire et de Physique des Particules de Saclay, 91 - Gif-sur-Yvette (France) CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Inst. de Recherche Fondamentale (IRF))

    1990-02-15

    Parallel plate avalanche counters have been designed and used for the localization of relativistic heavy ions. They have been tested with alpha particles from a {sup 241}Am source. They have been used with the heavy-ion beams from Saturne in conjunction with the 4{pi} detector Diogene. They provide an accurate measurement of the vertex position with high efficiency. (orig.).

  9. Laser chimeras as a paradigm for multistable patterns in complex systems

    Science.gov (United States)

    Larger, Laurent; Penkovsky, Bogdan; Maistrenko, Yuri

    2015-07-01

    A chimera state is a rich and fascinating class of self-organized solutions developed in high-dimensional networks. Necessary features of the network for the emergence of such complex but structured motions are non-local and symmetry breaking coupling. An accurate understanding of chimera states is expected to bring important insights on deterministic mechanism occurring in many structurally similar high-dimensional dynamics such as living systems, brain operation principles and even turbulence in hydrodynamics. Here we report on a powerful and highly controllable experiment based on an optoelectronic delayed feedback applied to a wavelength tuneable 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 state is gradually destroyed on the way to apparent turbulence-like system behaviour.

  10. Targeted chimera delivery to ovarian cancer cells by heterogeneous gold magnetic nanoparticle

    Science.gov (United States)

    Chen, Yao; Xu, Mengjiao; Guo, Yi; Tu, Keyao; Wu, Weimin; Wang, Jianjun; Tong, Xiaowen; Wu, Wenjuan; Qi, Lifeng; Shi, Donglu

    2017-01-01

    Efficient delivery of small interfering RNAs (siRNAs) to the targeted cells has remained a significant challenge in clinical applications. In the present study, we developed a novel aptamer-siRNA chimera delivery system mediated by cationic Au-Fe3O4 nanoparticles (NPs). The chimera constructed by VEGF RNA aptamer and Notch3 siRNA was bonded with heterogeneous Au-Fe3O4 nanoparticles by electrostatic interaction. The obtained complex exhibited much higher silencing efficiency against Notch3 gene compared with chimera alone and lipofectamine-siRNA complex, and improved the antitumor effects of the loaded chimera. Moreover, the efficient delivery of the chimera by Au-Fe3O4 NPs could reverse multi-drug resistance (MDR) of ovarian cancer cells against the chemotherapeutic drug cisplatin, indicating its potential capability for future targeted cancer therapy while overcoming MDR.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yong; Wang, Andrew; Qu Hao; Zocchi, Giovanni, E-mail: zocchi@physics.ucla.ed [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095-1547 (United States)

    2009-08-19

    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.

  17. 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.

  18. Mechanisms of appearance of amplitude and phase chimera states in ensembles of nonlocally coupled chaotic systems

    Science.gov (United States)

    Bogomolov, Sergey A.; Slepnev, Andrei V.; Strelkova, Galina I.; Schöll, Eckehard; Anishchenko, Vadim S.

    2017-02-01

    We explore the bifurcation transition from coherence to incoherence in ensembles of nonlocally coupled chaotic systems. It is firstly shown that two types of chimera states, namely, amplitude and phase, can be found in a network of coupled logistic maps, while only amplitude chimera states can be observed in a ring of continuous-time chaotic systems. We reveal a bifurcation mechanism by analyzing the evolution of space-time profiles and the coupling function with varying coupling coefficient and formulate the necessary and sufficient conditions for realizing the chimera states in the ensembles.

  19. 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.

  20. Overexpression of SDF-1α enhanced migration and engraftment of cardiac stem cells and reduced infarcted size via CXCR4/PI3K pathway.

    Directory of Open Access Journals (Sweden)

    Kui Wang

    Full Text Available Cardiac stem cells (CSCs can home to the infarcted area and regenerate myocardium. Stromal cell-derived factor-1α/C-X-C chemokine receptor type 4 (SDF-1α/CXCR4 axis is pivotal in inducing CSCs migration. However, the mechanisms remain unclear. This study set out to detect if SDF-1α promotes migration and engraftment of CSCs through the CXCR4/PI3K (phosphatidylinositol 3-kinase pathway. In the in vitro experiment, c-kit+ cells were isolated from neonatal mouse heart fragment culture by magnetic cell sorting. Fluorescence-activated cell sorting results demonstrated that a few c-kit+ cells expressed CD45 (4.54% and Sca-1 (2.58%, the hematopoietic stem cell marker. Conditioned culture could induce c-kit+ cells multipotent differentiation, which was confirmed by cardiac troponin I (cTn-I, α-smooth muscle actin (α-SMA, and von Willebrand factor (vWF staining. In vitro chemotaxis assays were performed using Transwell cell chambers to detect CSCs migration. The results showed that the cardiomyocytes infected with rAAV1-SDF-1α-eGFP significantly increased SDF-1α concentration, 5-fold more in supernatant than that in the control group, and subsequently attracted more CSCs migration. This effect was diminished by administration of AMD3100 (10 µg/ml, CXCR4 antagonist or LY294002 (20 µmol/L, PI3K inhibitor. In myocardial infarction mice, overexpression of SDF-1α in the infarcted area by rAAV1-SDF-1α-eGFP infection resulted in more CSCs retention to the infarcted myocardium, a higher percentage of proliferation, and reduced infarcted area which was attenuated by AMD3100 or ly294002 pretreatment. These results indicated that overexpression of SDF-1α enhanced CSCs migration in vitro and engraftment of transplanted CSCs and reduced infarcted size via CXCR4/PI3K pathway.

  1. GABAρ1/GABAAα1 receptor chimeras to study receptor desensitization

    Science.gov (United States)

    Martínez-Torres, Ataúlfo; Demuro, Angelo; Miledi, Ricardo

    2000-01-01

    γ-Aminobutyrate type C (GABAC) receptors are ligand-gated ion channels that are expressed preponderantly in the vertebrate retina and are characterized, among other things, by a very low rate of desensitization and resistance to the specific GABAA antagonist bicuculline. To examine which structural elements determine the nondesensitizing character of the human homomeric ρ1 receptor, we used a combination of gene chimeras and electrophysiology of receptors expressed in Xenopus oocytes. Two chimeric genes were constructed, made up of portions of the ρ1-subunit and of the α1-subunit of the GABAA receptor. When expressed in Xenopus oocytes, one chimeric gene (ρ1/α1) formed functional homooligomeric receptors that were fully resistant to bicuculline and were blocked by the specific GABAC antagonist (1,2,5,6-tetrahydropyridine-4-yl)methylphosphinic acid and by zinc. Moreover, these chimeric receptors had a fast-desensitizing component, even faster than that of heterooligomeric GABAA receptors, in striking contrast to the almost nil desensitization of wild-type ρ1 (wt ρ1) receptors. To see whether the fast-desensitizing characteristic of the chimera was determined by the amino acids forming the ion channels, we replaced the second transmembrane segment (TM2) of ρ1 by that of the α1-subunit of GABAA. Although the α1-subunit forms fast-desensitizing receptors when coexpressed with other GABAA subunits, the sole transfer of the α1TM2 segment to ρ1 was not sufficient to form desensitizing receptors. All this suggests that the slow-desensitizing trait of ρ1 receptors is determined by a combination of several interacting domains along the molecule. PMID:10725369

  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. Generation of chimeras by aggregation of embryonic stem cells with diploid or tetraploid mouse embryos.

    Science.gov (United States)

    Artus, Jérôme; Hadjantonakis, Anna-Katerina

    2011-01-01

    From the hybrid creatures of the Greek and Egyptian mythologies, the concept of the chimera has evolved and, in modern day biology, refers to an organism comprises of at least two populations of genetically distinct cells. Mouse chimeras have proven an invaluable tool for the generation of genetically modified strains. In addition, chimeras have been extensively used in developmental biology as a powerful tool to analyze the phenotype of specific mutations, to attribute function to gene products and to address the question of cell autonomy versus noncell autonomy of gene function. This chapter describes a simple and economical technique used to generate mouse chimeras by embryo aggregation. Multiple aggregation combinations are described each of which can be tailored to answer particular biological questions.

  4. Chimera states in a network-organized public goods game with destructive agents

    Science.gov (United States)

    Kouvaris, Nikos E.; Requejo, Rubén J.; Hizanidis, Johanne; Díaz-Guilera, Albert

    2016-12-01

    We found that a network-organized metapopulation of cooperators, defectors, and destructive agents playing the public goods game with mutations can collectively reach global synchronization or chimera states. Global synchronization is accompanied by a collective periodic burst of cooperation, whereas chimera states reflect the tendency of the networked metapopulation to be fragmented in clusters of synchronous and incoherent bursts of cooperation. Numerical simulations have shown that the system's dynamics switches between these two steady states through a first order transition. Depending on the parameters determining the dynamical and topological properties, chimera states with different numbers of coherent and incoherent clusters are observed. Our results present the first systematic study of chimera states and their characterization in the context of evolutionary game theory. This provides a valuable insight into the details of their occurrence, extending the relevance of such states to natural and social systems.

  5. 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.

  6. Chimeras in globally coupled oscillatory systems: From ensembles of oscillators to spatially continuous media

    Science.gov (United States)

    Schmidt, Lennart; Krischer, Katharina

    2015-06-01

    We study an oscillatory medium with a nonlinear global coupling that gives rise to a harmonic mean-field oscillation with constant amplitude and frequency. Two types of cluster states are found, each undergoing a symmetry-breaking transition towards a related chimera state. We demonstrate that the diffusional coupling is non-essential for these complex dynamics. Furthermore, we investigate localized turbulence and discuss whether it can be categorized as a chimera state.

  7. 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.

  8. 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.

  9. 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.

  10. Formyl peptide receptor chimeras define domains involved in ligand binding.

    Science.gov (United States)

    Perez, H D; Holmes, R; Vilander, L R; Adams, R R; Manzana, W; Jolley, D; Andrews, W H

    1993-02-05

    We have begun to study the structural requirements for the binding of formyl peptides to their specific receptors. As an initial approach, we constructed C5a-formyl peptide receptor chimeras. Unique (and identical) restriction sites were introduced within the transmembrane domains of these receptors that allowed for the exchange of specific areas. Four types of chimeric receptors were generated. 1) The C5a receptor was progressively substituted by the formyl peptide receptor. 2) The formyl peptide receptor was progressively substituted by the C5a receptor. 3) Specific domains of the C5a receptor were substituted by the corresponding domain of the formyl peptide receptor. 4) Specific domains of the formyl peptide receptor were replaced by the same corresponding domain of the C5a receptor. Wild type and chimeric receptors were transfected into COS 7 cells and their ability to bind formyl peptide determined, taking into account efficiency of transfection and expression of chimeric protein. Based on these results, a ligand binding model is presented in which the second, third, and fourth extracellular (and/or their transmembrane) domains together with the first transmembrane domain form a ligand binding pocket for formyl peptides. It is proposed that the amino-terminal domain plays a role by presumably providing a "lid" to the pocket. The carboxyl-terminal cytoplasmic tail appears to modulate ligand binding by regulating receptor affinity.

  11. 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.

  12. 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.

  13. Engineering human cytochrome P450 enzymes into catalytically self-sufficient chimeras using molecular Lego.

    Science.gov (United States)

    Dodhia, Vikash Rajnikant; Fantuzzi, Andrea; Gilardi, Gianfranco

    2006-10-01

    The membrane-bound human cytochrome P450s have essential roles in the metabolism of endogenous compounds and drugs. Presented here are the results on the construction and characterization of three fusion proteins containing the N-terminally modified human cytochrome P450s CYP2C9, CY2C19 and CYP3A4 fused to the soluble NADPH-dependent oxidoreductase domain of CYP102A1 from Bacillus megaterium. The constructs, CYP2C9/BMR, CYP2C19/BMR and CYP3A4/BMR are well expressed in Escherichia coli as holo proteins. The chimeras can be purified in the absence of detergent and the purified enzymes are both active and correctly folded in the absence of detergent, as demonstrated by circular dichroism and functional studies. Additionally, in comparison with the parent P450 enzyme, these chimeras have greatly improved solubility properties. The chimeras are catalytically self-sufficient and present turnover rates similar to those reported for the native enzymes in reconstituted systems, unlike previously reported mammalian cytochrome P450 fusion proteins. Furthermore the specific activities of these chimeras are not dependent on the enzyme concentration present in the reaction buffer and they do not require the addition of accessory proteins, detergents or phospholipids to be fully active. The solubility, catalytic self-sufficiency and wild-type like activities of these chimeras would greatly simplify the studies of cytochrome P450 mediated drug metabolism in solution.

  14. 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.

  15. Multicluster and traveling chimera states in nonlocal phase-coupled oscillators.

    Science.gov (United States)

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

    2014-08-01

    Chimera states consisting of domains of coherently and incoherently oscillating identical oscillators with nonlocal coupling are studied. These states usually coexist with the fully synchronized state and have a small basin of attraction. We propose a nonlocal phase-coupled model in which chimera states develop from random initial conditions. Several classes of chimera states have been found: (a) stationary multicluster states with evenly distributed coherent clusters, (b) stationary multicluster states with unevenly distributed clusters, and (c) a single cluster state traveling with a constant speed across the system. Traveling coherent states are also identified. A self-consistent continuum description of these states is provided and their stability properties analyzed through a combination of linear stability analysis and numerical simulation.

  16. 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.

  17. Glassy Chimeras Could Be Blind to Quantum Speedup: Designing Better Benchmarks for Quantum Annealing Machines

    Science.gov (United States)

    Katzgraber, Helmut G.; Hamze, Firas; Andrist, Ruben S.

    2014-04-01

    Recently, a programmable quantum annealing machine has been built that minimizes the cost function of hard optimization problems by, in principle, adiabatically quenching quantum fluctuations. Tests performed by different research teams have shown that, indeed, the machine seems to exploit quantum effects. However, experiments on a class of random-bond instances have not yet demonstrated an advantage over classical optimization algorithms on traditional computer hardware. Here, we present evidence as to why this might be the case. These engineered quantum annealing machines effectively operate coupled to a decohering thermal bath. Therefore, we study the finite-temperature critical behavior of the standard benchmark problem used to assess the computational capabilities of these complex machines. We simulate both random-bond Ising models and spin glasses with bimodal and Gaussian disorder on the D-Wave Chimera topology. Our results show that while the worst-case complexity of finding a ground state of an Ising spin glass on the Chimera graph is not polynomial, the finite-temperature phase space is likely rather simple because spin glasses on Chimera have only a zero-temperature transition. This means that benchmarking optimization methods using spin glasses on the Chimera graph might not be the best benchmark problems to test quantum speedup. We propose alternative benchmarks by embedding potentially harder problems on the Chimera topology. Finally, we also study the (reentrant) disorder-temperature phase diagram of the random-bond Ising model on the Chimera graph and show that a finite-temperature ferromagnetic phase is stable up to 19.85(15)% antiferromagnetic bonds. Beyond this threshold, the system only displays a zero-temperature spin-glass phase. Our results therefore show that a careful design of the hardware architecture and benchmark problems is key when building quantum annealing machines.

  18. 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.

  19. 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.

  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. "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…

  2. CHIMERA: Clustering of Heterogeneous Disease Effects via Distribution Matching of Imaging Patterns.

    Science.gov (United States)

    Dong, Aoyan; Honnorat, Nicolas; Gaonkar, Bilwaj; Davatzikos, Christos

    2016-02-01

    Many brain disorders and diseases exhibit heterogeneous symptoms and imaging characteristics. This heterogeneity is typically not captured by commonly adopted neuroimaging analyses that seek only a main imaging pattern when two groups need to be differentiated (e.g., patients and controls, or clinical progressors and non-progressors). We propose a novel probabilistic clustering approach, CHIMERA, modeling the pathological process by a combination of multiple regularized transformations from normal/control population to the patient population, thereby seeking to identify multiple imaging patterns that relate to disease effects and to better characterize disease heterogeneity. In our framework, normal and patient populations are considered as point distributions that are matched by a variant of the coherent point drift algorithm. We explain how the posterior probabilities produced during the MAP optimization of CHIMERA can be used for clustering the patients into groups and identifying disease subtypes. CHIMERA was first validated on a synthetic dataset and then on a clinical dataset mixing 317 control subjects and patients suffering from Alzheimer's Disease (AD) and Parkison's Disease (PD). CHIMERA produced better clustering results compared to two standard clustering approaches. We further analyzed 390 T1 MRI scans from Alzheimer's patients. We discovered two main and reproducible AD subtypes displaying significant differences in cognitive performance.

  3. 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.

  4. 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.).

  5. 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.

  6. Pixel Detectors

    OpenAIRE

    Wermes, Norbert

    2005-01-01

    Pixel detectors for precise particle tracking in high energy physics have been developed to a level of maturity during the past decade. Three of the LHC detectors will use vertex detectors close to the interaction point based on the hybrid pixel technology which can be considered the state of the art in this field of instrumentation. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as the very harsh...

  7. 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.

  8. Metal Detectors.

    Science.gov (United States)

    Harrington-Lueker, Donna

    1992-01-01

    Schools that count on metal detectors to stem the flow of weapons into the schools create a false sense of security. Recommendations include investing in personnel rather than hardware, cultivating the confidence of law-abiding students, and enforcing discipline. Metal detectors can be quite effective at afterschool events. (MLF)

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Functional prokaryotic-eukaryotic chimera from the pentameric ligand-gated ion channel family.

    Science.gov (United States)

    Duret, Guillaume; Van Renterghem, Catherine; Weng, Yun; Prevost, Marie; Moraga-Cid, Gustavo; Huon, Christèle; Sonner, James M; Corringer, Pierre-Jean

    2011-07-19

    Pentameric ligand-gated ion channels (pLGICs), which mediate chemo-electric signal transduction in animals, have been recently found in bacteria. Despite clear sequence and 3D structure homology, the phylogenetic distance between prokaryotic and eukaryotic homologs suggests significant structural divergences, especially at the interface between the extracellular (ECD) and the transmembrane (TMD) domains. To challenge this possibility, we constructed a chimera in which the ECD of the bacterial protein GLIC is fused to the TMD of the human α1 glycine receptor (α1GlyR). Electrophysiology in Xenopus oocytes shows that it functions as a proton-gated ion channel, thereby locating the proton activation site(s) of GLIC in its ECD. Patch-clamp experiments in BHK cells show that the ion channel displays an anionic selectivity with a unitary conductance identical to that of the α1GlyR. In addition, pharmacological investigations result in transmembrane allosteric modulation similar to the one observed on α1GlyR. Indeed, the clinically active drugs propofol, four volatile general anesthetics, alcohols, and ivermectin all potentiate the chimera while they inhibit GLIC. Collectively, this work shows the compatibility between GLIC and α1GlyR domains and points to conservation of the ion channel and transmembrane allosteric regulatory sites in the chimera. This provides evidence that GLIC and α1GlyR share a highly homologous 3D structure. GLIC is thus a relevant model of eukaryotic pLGICs, at least from the anionic type. In addition, the chimera is a good candidate for mass production in Escherichia coli, opening the way for investigations of "druggable" eukaryotic allosteric sites by X-ray crystallography.

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  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. XMASS detector

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hieda, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Hiraide, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hirano, S. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kishimoto, Y.; Kobayashi, K.; Moriyama, S. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nakagawa, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Nakahata, M. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishiie, H. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Ogawa, H. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); and others

    2013-07-11

    The XMASS project aims to detect dark matter, pp and {sup 7}Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.

  20. XMASS detector

    CERN Document Server

    Abe, K; Hiraide, K; Hirano, S; Kishimoto, Y; Kobayashi, K; Moriyama, S; Nakagawa, K; Nakahata, M; Nishiie, H; Ogawa, H; Oka, N; Sekiya, H; Shinozaki, A; Suzuki, Y; Takeda, A; Takachio, O; Ueshima, K; Umemoto, D; Yamashita, M; Yang, B S; Tasaka, S; Liu, J; Martens, K; Hosokawa, K; Miuchi, K; Murata, A; Onishi, Y; Otsuka, Y; Takeuchi, Y; Kim, Y H; Lee, K B; Lee, M K; Lee, J S; Fukuda, Y; Itow, Y; Nishitani, Y; Masuda, K; Takiya, H; Uchida, H; Kim, N Y; Kim, Y D; Kusaba, F; Motoki, D; Nishijima, K; Fujii, K; Murayama, I; Nakamura, S

    2013-01-01

    The XMASS project aims to detect dark matter, pp and $^{7}$Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.

  1. 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.

  2. 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

  3. 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...

  4. Embryonic stem cell/fibroblast hybrid cells with near-tetraploid karyotype provide high yield of chimeras.

    Science.gov (United States)

    Kruglova, A A; Kizilova, E A; Zhelezova, A I; Gridina, M M; Golubitsa, A N; Serov, O L

    2008-12-01

    Ten primary clones of hybrid cells were produced by the fusion of diploid embryonic stem (ES) cells, viz., line E14Tg2aSc4TP6.3 marked by green fluorescent protein (GFP), with diploid embryonic or adult fibroblasts derived from DD/c mice. All the hybrid clones had many characteristics similar to those of ES cells and were positive for GFP. Five hybrid clones having ploidy close to tetraploidy (over 80% of cells had 76-80 chromosomes) were chosen for the generation of chimeras via injection into C57BL blastocysts. These hybrid clones also contained microsatellites marking all ES cell and fibroblast chromosomes judging from microsatellite analysis. Twenty chimeric embryos at 11-13 days post-conception were obtained after injection of hybrid cells derived from two of three clones. Many embryos showed a high content of GFP-positive descendents of the tested hybrid cells. Twenty one adult chimeras were generated by the injection of hybrid cells derived from three clones. The contribution of GFP-labeled hybrid cells was significant and comparable with that of diploid E14Tg2aSc4TP6.3 cells. Cytogenetic and microsatellite analyses of cell cultures derived from chimeric embryos or adults indicated that the initial karyotype of the tested hybrid cells remained stable during the development of the chimeras, i.e., the hybrid cells were mainly responsible for the generation of the chimeras. Thus, ES cell/fibroblast hybrid cells with near-tetraploid karyotype are able to generate chimeras at a high rate, and many adult chimeras contain a high percentage of descendants of the hybrid cells.

  5. Semiconductor Detectors; Detectores de Semiconductores

    Energy Technology Data Exchange (ETDEWEB)

    Cortina, E.

    2007-07-01

    Particle detectors based on semiconductor materials are among the few devices used for particle detection that are available to the public at large. In fact we are surrounded by them in our daily lives: they are used in photoelectric cells for opening doors, in digital photographic and video camera, and in bar code readers at supermarket cash registers. (Author)

  6. Resistance to infection with Eimeria vermiformis in mouse radiation chimeras is determined by donor bone-marrow cells

    Energy Technology Data Exchange (ETDEWEB)

    Joysey, H.S.; Wakelin, D.; Rose, M.E.

    1988-05-01

    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.

  7. 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.

  8. Transient scaling and resurgence of chimera states in networks of Boolean phase oscillators

    Science.gov (United States)

    Rosin, David P.; Rontani, Damien; Haynes, Nicholas D.; Schöll, Eckehard; Gauthier, Daniel J.

    2014-09-01

    We study networks of nonlocally coupled electronic oscillators that can be described approximately by a Kuramoto-like model. The experimental networks show long complex transients from random initial conditions on the route to network synchronization. The transients display complex behaviors, including resurgence of chimera states, which are network dynamics where order and disorder coexists. The spatial domain of the chimera state moves around the network and alternates with desynchronized dynamics. The fast time scale of our oscillators (on the order of 100ns) allows us to study the scaling of the transient time of large networks of more than a hundred nodes, which has not yet been confirmed previously in an experiment and could potentially be important in many natural networks. We find that the average transient time increases exponentially with the network size and can be modeled as a Poisson process in experiment and simulation. This exponential scaling is a result of a synchronization rate that follows a power law of the phase-space volume.

  9. Fluorescent protein-scorpion toxin chimera is a convenient molecular tool for studies of potassium channels.

    Science.gov (United States)

    Kuzmenkov, Alexey I; Nekrasova, Oksana V; Kudryashova, Kseniya S; Peigneur, Steve; Tytgat, Jan; Stepanov, Alexey V; Kirpichnikov, Mikhail P; Grishin, Eugene V; Feofanov, Alexey V; Vassilevski, Alexander A

    2016-09-21

    Ion channels play a central role in a host of physiological and pathological processes and are the second largest target for existing drugs. There is an increasing need for reliable tools to detect and visualize particular ion channels, but existing solutions suffer from a number of limitations such as high price, poor specificity, and complicated protocols. As an alternative, we produced recombinant chimeric constructs (FP-Tx) consisting of fluorescent proteins (FP) fused with potassium channel toxins from scorpion venom (Tx). In particular, we used two FP, eGFP and TagRFP, and two Tx, OSK1 and AgTx2, to create eGFP-OSK1 and RFP-AgTx2. We show that these chimeras largely retain the high affinity of natural toxins and display selectivity to particular ion channel subtypes. FP-Tx are displaced by other potassium channel blockers and can be used as an imaging tool in ion channel ligand screening setups. We believe FP-Tx chimeras represent a new efficient molecular tool for neurobiology.

  10. Proceedings of the third workshop on experiments and detectors for a relativistic heavy ion collider (RHIC)

    Energy Technology Data Exchange (ETDEWEB)

    Shivakumar, B.; Vincent, P.

    1988-01-01

    This report contains papers on the following topics: the RHIC Project; summary of the working group on calorimetry; J//Psi/ measurements in heavy ion collisions at CERN; QCD jets at RHIC; tracking and particle identification; a 4..pi.. tracking spectrometer for RHIC; Bose-Einstein measurements at RHIC in light of new data; summary of working group on read-out electronics; data acquisition for RHIC; summary of the working group on detector simulation; B-physics at RHIC; and CP violation revisited at BNL, B-physics at RHIC.

  11. 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...

  12. 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

  13. EpCAM Aptamer-siRNA Chimera Targets and Regress Epithelial Cancer.

    Directory of Open Access Journals (Sweden)

    Nithya Subramanian

    Full Text Available Epithelial cell adhesion molecule (EpCAM, a cancer stem cell (CSC marker is over expressed in epithelial cancers and in retinoblastoma (RB. We fabricated an EpCAM targeting aptamer-siRNA chimera and investigated its anti-tumor property and EpCAM intracellular domain (EpICD mediated signaling in epithelial cancer. The anti-tumor efficacy of EpCAM aptamer-siEpCAM chimera (EpApt-siEp was evaluated by qPCR, northern and Western blotting in WERI-Rb1- RB cell line, primary RB tumor cells and in MCF7- breast cancer cell line. Anti-tumor activity of EpApt-siEp was studied in vivo using epithelial cancer (MCF7 mice xenograft model. The mechanism and pathways involved in the anti-tumor activity was further studied using protein arrays and qPCR. EpApt-siEp chimera was processed in vitro by dicer enzyme. Treatment of the WERI-Rb1 and MCF7 cells with EpApt-siEp revealed statistically significant down regulation of EpCAM expression (P<0.005 and concomitant reduction in cellular proliferation. In primary RB cells cultured from RB tumors, EpApt-siEp silenced EpCAM, significantly inhibited (P<0.01 cell proliferation and induced cytotoxicity. Knockdown of EpICD expressed in RB primary tumors led to repression of pluripotency markers, SOX2, OCT4, NANOG, and CD133. In vivo studies showed complete tumor growth regression without any toxicity in animals (P<0.001 and tumor tissues showed significant downregulation (P<0.05 of EpCAM, MRP1, ABCG2, stathmin, survivin and upregulation of ATM (P<0.05 leading to apoptosis by intrinsic pathway with minor alteration in cytokines. Our results revealed that EpApt-siEp potentially eradicated EpCAM positive cancer cells through CSC marker suppression and apoptosis, while sparing normal EpCAM negative adjacent cells.

  14. 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.

  15. 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.

  16. Chimera distribution amplitudes for the pion and the longitudinally polarized ρ-meson

    Energy Technology Data Exchange (ETDEWEB)

    Stefanis, N.G., E-mail: stefanis@tp2.ruhr-uni-bochum.de [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Pimikov, A.V., E-mail: pimikov@theor.jinr.ru [Bogoliubov Laboratory of Theoretical Physics, JINR, 141980 Dubna (Russian Federation); Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China)

    2016-01-15

    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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Tissue distribution of cells derived from the area opaca in heterospecific quail-chick blastodermal chimeras.

    Science.gov (United States)

    Karagenç, Levent; Sandikci, Mustafa

    2010-01-01

    The objective of the current study was to determine the tissue distribution of cells derived from the area opaca in heterospecific quail-chick blastodermal chimeras. Quail-chick chimeras were constructed by transferring dissociated cells from the area opaca of the stage X-XII (EG&K) quail embryo into the subgerminal cavity of the unincubated chick blastoderm. The distribution of quail cells in embryonic as well as extra-embryonic tissues of the recipient embryo were examined using the QCPN monoclonal antibody after 6 days of incubation in serial sections taken at 100-mum intervals. Data gathered in the present study demonstrated that, when introduced into the subgerminal cavity of a recipient embryo, cells of the area opaca are able to populate not only extra-embryonic structures such as the amnion and the yolk sac, but also various embryonic tissues derived from the ectoderm and less frequently the mesoderm. Ectodermal chimerism was confined mainly to the head region and was observed in tissues derived from the neural ectoderm and the surface ectoderm, including the optic cup, diencephalon and lens. Although the possibility of random incorporation of transplanted cells into these embryonic structures cannot be excluded, these results would suggest that area opaca, a peripheral ring of cells in the avian embryo destined to form the extra-embryonic ectoderm and endoderm of the yolk sac, might harbor cells that have the potential to give rise to various cell types in the recipient chick embryo, including those derived from the surface ectoderm and neural ectoderm.

  2. 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.

  3. Pixel Vertex Detectors

    OpenAIRE

    Wermes, Norbert

    2006-01-01

    Pixel vertex detectors are THE instrument of choice for the tracking of charged particles close to the interaction point at the LHC. Hybrid pixel detectors, in which sensor and read-out IC are separate entities, constitute the present state of the art in detector technology. Three of the LHC detectors use vertex detectors based on this technology. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as ...

  4. 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

    , and this was parallel by the largest reduction in number of viable bacteria. CONCLUSION: We found that chain length but not type of cationic amino acid influenced the antibacterial activity of a series of synthetic α-peptide/β-peptoid chimeras. The synthetic chimeras exert their killing effect by permeabilization......BACKGROUND: Characterization and use of antimicrobial peptides (AMPs) requires that their mode of action is determined. The interaction of membrane-active peptides with their target is often established using model membranes, however, the actual permeabilization of live bacterial cells...... 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...

  5. 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...

  6. Generation of mouse chimeras with high contribution of tetraploid embryonic stem cells and embryonic stem cell-fibroblast hybrid cells.

    Science.gov (United States)

    Matveeva, Natalia M; Kizilova, Elena A; Serov, Oleg L

    2015-01-01

    The in vitro long-term cultivation of embryonic stem (ES) cells derived from pre-implantation embryos offers the unique possibility of combining ES cells with pre-implantation embryos to generate chimeras, thus facilitating the creation of a bridge between in vitro and in vivo investigations. Genomic manipulation using ES cells and homologous recombination is one of the most outstanding scientific achievements, resulting in the generation of animals with desirable genome modifications. As such, the generation of ES cells with different ploidy via cell fusion also deserves much attention because this approach allows for the production of chimeras that contain somatic cells with various ploidy. Therefore, this is a powerful tool that can be used to study the role of polyploidy in the normal development of mammals.

  7. Antigenic characteristics of rhinovirus chimeras designed in silico for enhanced presentation of HIV-1 gp41 epitopes [corrected].

    Science.gov (United States)

    Lapelosa, Mauro; Arnold, Gail Ferstandig; Gallicchio, Emilio; Arnold, Eddy; Levy, Ronald M

    2010-04-02

    The development of an effective AIDS vaccine remains the most promising long-term strategy to combat human immunodeficiency virus (HIV)/AIDS. Here, we report favorable antigenic characteristics of vaccine candidates isolated from a combinatorial library of human rhinoviruses displaying the ELDKWA epitope of the gp41 glycoprotein of HIV-1. The design principles of this library emerged from the application of molecular modeling calculations in conjunction with our knowledge of previously obtained ELDKWA-displaying chimeras, including knowledge of a chimera with one of the best 2F5-binding characteristics obtained to date. The molecular modeling calculations identified the energetic and structural factors affecting the ability of the epitope to assume conformations capable of fitting into the complementarity determining region of the ELDKWA-binding, broadly neutralizing human mAb 2F5. Individual viruses were isolated from the library following competitive immunoselection and were tested using ELISA and fluorescence quenching experiments. Dissociation constants obtained using both techniques revealed that some of the newly isolated chimeras bind 2F5 with greater affinity than previously identified chimeric rhinoviruses. Molecular dynamics simulations of two of these same chimeras confirmed that their HIV inserts were partially preorganized for binding, which is largely responsible for their corresponding gains in binding affinity. The study illustrates the utility of combining structure-based experiments with computational modeling approaches for improving the odds of selecting vaccine component designs with preferred antigenic characteristics. The results obtained also confirm the flexibility of HRV as a presentation vehicle for HIV epitopes and the potential of this platform for the development of vaccine components against AIDS.

  8. 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.

  9. A Direct Mapping of Max k-SAT and High Order Parity Checks to a Chimera Graph

    Science.gov (United States)

    Chancellor, N.; Zohren, S.; Warburton, P. A.; Benjamin, S. C.; Roberts, S.

    2016-11-01

    We demonstrate a direct mapping of max k-SAT problems (and weighted max k-SAT) to a Chimera graph, which is the non-planar hardware graph of the devices built by D-Wave Systems Inc. We further show that this mapping can be used to map a similar class of maximum satisfiability problems where the clauses are replaced by parity checks over potentially large numbers of bits. The latter is of specific interest for applications in decoding for communication. We discuss an example in which the decoding of a turbo code, which has been demonstrated to perform near the Shannon limit, can be mapped to a Chimera graph. The weighted max k-SAT problem is the most general class of satisfiability problems, so our result effectively demonstrates how any satisfiability problem may be directly mapped to a Chimera graph. Our methods faithfully reproduce the low energy spectrum of the target problems, so therefore may also be used for maximum entropy inference.

  10. The ethics of killing human/great-ape chimeras for their organs: a reply to Shaw et al.

    Science.gov (United States)

    Palacios-González, César

    2016-06-01

    The aim of this paper is to critically examine David Shaw, Wybo Dondorp, and Guido de Wert's arguments in favour of the procurement of human organs from human/nonhuman-primate chimeras, specifically from great-ape/human chimeras. My main claim is that their arguments fail and are in need of substantial revision. To prove this I first introduce the topic, and then reconstruct Shaw et al.'s position and arguments. Next, I show that Shaw et al.: (1) failed to properly apply the subsidiarity and proportionality principles; (2) neglected species overlapping cases in their ethical assessment; (3) ignored the ethics literature on borderline persons; and (4) misunderstood McMahan's two-tiered moral theory. These mistakes render an important part of their conclusions either false or problematic to the point that they would no longer endorse them. Finally I will briefly mention a possible multipolar solution to the human organ shortage problem that would reduce the need for chimeras' organs.

  11. Contribution of cells derived from the area pellucida to extraembryonic mesodermal cell lineages in heterospecific quail chick blastodermal chimeras.

    Science.gov (United States)

    Karagenç, Levent; Sandikci, Mustafa

    2013-01-01

    The current study has two main objectives: first, to determine if cells derived from the area pellucida are able to populate extraembryonic membranes, and second, to determine if donor cells have the potential to differentiate to endothelial (EC) and hematopoietic cells (HC) in the yolk sac and allantois, the two extraembryonic membranes functioning as hematopoietic organs in the avian embryo. To this end, quail chick chimeras were constructed by transferring dissociated cells from the areae pellucidae of the stage X-XII (EG&K) quail embryo into the subgerminal cavity of the unincubated chick blastoderm. The distribution of quail cells in the allantois, yolk sac, amnion, and chorion of resulting putative chimeras was examined using quail cell-specific antibody against a perinuclear antigen (QCPN) after 6 days of incubation. The presence of EC, HC, and smooth muscle cells among the QCPN(+) donor cells was examined using QH-1, a quail-specific marker identifying HC and EC and an anti-α-smooth muscle actin antibody. Evidence gathered in the present study demonstrates that quail cells derived from the areae pellucidae are able to populate all of the extraembryonic membranes of resulting heterospecific quail chick chimeras and, most importantly, give rise to HC, EC, and smooth muscle cells, all of the three main mesodermal lineages derived from the posterior mesoderm both in the yolk sac and allantois.

  12. Clonal and territorial development of the pancreas as revealed by eGFP-labelled mouse chimeras.

    Science.gov (United States)

    Eberhard, Daniel; Jockusch, Harald

    2010-10-01

    The clonal structure of the pancreas was analysed in neonatal and adult mouse chimeras in which one partner displayed cell patches expressing green fluorescent protein (eGFP). Coherent growth during pancreatic histogenesis was suggested by the presence of large eGFP-labelled acinar clusters rather than a scattered distribution of individual labelled acinar cells. The adult chimeric pancreas contained monophenotypic acini, whereas surprisingly 5% of acini in neonates were polyclonal. Monophenotypic acini presumably arose by coherent expansion leading to large 3D patches and may not be monoclonal. Islets of Langerhans were oligoclonal at both ages investigated. The proportion of eGFP positive cells within islets did not correlate with that of the surrounding acinar tissue indicating clonal independence of islets from their neighbourhood. The patterns observed argue against a secondary contribution of blood-borne progenitor/stem cells to the acinar compartment during tissue turnover. The different clonal origins of acini and islets are integrated into a model of pancreatic histogenesis.

  13. 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.

  14. 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

    2016-06-29

    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.

  15. Spatially organized dynamical states in chemical oscillator networks: synchronization, dynamical differentiation, and chimera patterns.

    Directory of Open Access Journals (Sweden)

    Mahesh Wickramasinghe

    Full Text Available Dynamical processes in many engineered and living systems take place on complex networks of discrete dynamical units. We present laboratory experiments with a networked chemical system of nickel electrodissolution in which synchronization patterns are recorded in systems with smooth periodic, relaxation periodic, and chaotic oscillators organized in networks composed of up to twenty dynamical units and 140 connections. The reaction system formed domains of synchronization patterns that are strongly affected by the architecture of the network. Spatially organized partial synchronization could be observed either due to densely connected network nodes or through the 'chimera' symmetry breaking mechanism. Relaxation periodic and chaotic oscillators formed structures by dynamical differentiation. We have identified effects of network structure on pattern selection (through permutation symmetry and coupling directness and on formation of hierarchical and 'fuzzy' clusters. With chaotic oscillators we provide experimental evidence that critical coupling strengths at which transition to identical synchronization occurs can be interpreted by experiments with a pair of oscillators and analysis of the eigenvalues of the Laplacian connectivity matrix. The experiments thus provide an insight into the extent of the impact of the architecture of a network on self-organized synchronization patterns.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. A large acceptance scintillator detector with wavelength shifting fibre readout for search of {eta}-nucleus bound states

    Energy Technology Data Exchange (ETDEWEB)

    Betigeri, M.G.; Chatterjee, A.; Roy, B.J.; Shukla, P. [Nuclear Physics Div., BARC, Mumbai 400 085 (India); Biswas, P.K.; Guha, S.; Jawale, S.B. [Centre for Design and Manufacture, BARC, Mumbai 400 085 (India); Budzanowski, A. [Inst. of Nuclear Physics, Polish Academy of Sciences, Krakow (Poland); Jahn, R. [Helmholtz-Inst. fuer Strahlen- und Kernphysik der Univ. Bonn, Bonn (Germany); Hawranek, P. [Inst. of Physics, Jagellonian Univ., Krakow (Poland); Jain, B.K. [Physics Dept., Mumbai Univ., Vidyanagari, Mumbai (India); Jha, V. [Nuclear Physics Div., BARC, Mumbai 400 085 (India)]. E-mail: vjha@barc.gov.in; Kilian, K.; Kirillov, Da.; Lesiak, M.; Maier, R.; Prasuhn, D.; Protic, D.; Ritman, J.; von Rossen, P. [Inst. fuer Kernphysik, Forschungszentrum Juelich, Juelich (Germany); Kliczewski, S. [Inst. of Nuclear Physics, Polish Academy of Sciences, Krakow (Poland); Kirillov, Di.; Piskunov, N.; Sitnik, I. [Lab. for High Energies, JINR Dubna (Russian Federation); Kolev, D. [Physics Faculty, Univ. of Sofia, Sofia (Bulgaria); Kravcikova, M. [Technical Univ. Kosice, Kosice (Slovakia); Kutsarova, T. [Inst. of Nuclear Physics and Nuclear Energy, Sofia (Bulgaria); Lieb, J. [Physics Dept., George Mason Univ., Fairfax, VA (United States); Machner, H. [Inst. fuer Kernphysik, Forschungszentrum Juelich, Juelich (Germany)]|[Fachbereich Physik, Univ. Duisburg-Essen, Duisburg (Germany); Magiera, A. [Inst. of Physics, Jagellonian Univ., Krakow (Poland); Martinska, G.; Ulicny, M.; Urban, J. [P. J. Safarik Univ., Kosice, (Slovakia); Nedev, S. [Univ. of Chemical Technology and Metallurgy, Sofia (Bulgaria); Siudak, R. [Inst. of Nuclear Physics, Polish Academy of Sciences, Krakow (Poland)]|[Inst. fuer Kernphysik, Forschungszentrum Juelich, Juelich (Germany); Tsenov, R. [Physics Faculty, Univ. of Sofia, Sofia (Bulgaria); Vankova, G. [Inst. fuer Kernphysik, Forschungszentrum Juelich, Juelich (Germany)]|[Physics Faculty, Univ. of Sofia, Sofia (Bulgaria)

    2007-07-21

    A large acceptance scintillator detector with wavelength shifting optical fibre readout has been designed and built to detect the decay particles of {eta}-nucleus bound system (the so-called {eta}-mesic nuclei), namely, protons and pions. The detector, named as ENSTAR detector, consists of 122 pieces of plastic scintillator of various shapes and sizes, which are arranged in a cylindrical geometry to provide particle identification, energy loss and coarse position information for these particles. A solid angle coverage of {approx}95% of total 4{pi} is obtained in the present design of the detector. Monte Carlo phase space calculations performed to simulate the formation and decay of {eta}-mesic nuclei suggest that its decay particles, the protons and pions are emitted with an opening angle of 150+/-20{sup a}t, and with energies in the range of 25-300 and 225-450MeV, respectively. The detailed GEANT simulations show that {approx}80 % of the decay particles (protons and pions) can be detected within ENSTAR. Several test measurements using alpha source, cosmic-ray muons, etc. have been carried out to study the response of ENSTAR scintillator pieces. The in-beam tests of fully assembled detector with proton beam of momentum 870MeV/c from the Cooler synchrotron COSY have been performed. The test results show that the scintillator fibre design chosen for the detector has performed satisfactorily well. The present article describes the detector design, simulation studies, construction details and test results.

  2. 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.

  3. Fourth workshop on experiments and detectors for a relativistic heavy ion collider

    Energy Technology Data Exchange (ETDEWEB)

    Fatyga, M.; Moskowitz, B. (eds.)

    1990-01-01

    This report contains papers on the following topics: physics at RHIC; flavor flow from quark-gluon plasma; space-time quark-gluon cascade; jets in relativistic heavy ion collisions; parton distributions in hard nuclear collisions; experimental working groups, two-arm electron/photon spectrometer collaboration; total and elastic pp cross sections; a 4{pi} tracking TPC magnetic spectrometer; hadron spectroscopy; efficiency and background simulations for J/{psi} detection in the RHIC dimuon experiment; the collision regions beam crossing geometries; Monte Carlo simulations of interactions and detectors; proton-nucleus interactions; the physics of strong electromagnetic fields in collisions of relativistic heavy ions; a real time expert system for experimental high energy/nuclear physics; the development of silicon multiplicity detectors; a pad readout detector for CRID/tracking; RHIC TPC R D progress and goals; development of analog memories for RHIC detector front-end electronic systems; calorimeter/absorber optimization for a RHIC dimuon experiment; construction of a highly segmented high resolution TOF system; progress report on a fast, particle-identifying trigger based on ring-imaging and highly integrated electronics for a TPC detector.

  4. Thermal kinetic inductance detector

    Energy Technology Data Exchange (ETDEWEB)

    Cecil, Thomas; Gades, Lisa; Miceli, Antonio; Quaranta, Orlando

    2016-12-20

    A microcalorimeter for radiation detection that uses superconducting kinetic inductance resonators as the thermometers. The detector is frequency-multiplexed which enables detector systems with a large number of pixels.

  5. 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.

  6. The CAPRICE RICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Basini, G. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Codino, A.; Grimani, C. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `Tor Vergata` Rome (Italy); Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Brancaccio, F.; Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy)

    1995-09-01

    A compact RICH detector has been developed and used for particle identification in a balloon borne spectrometer to measure the flux of antimatter in the cosmic radiation. This is the first RICH detector ever used in space experiments that is capable of detecting unit charged particles, such as antiprotons. The RICH and all other detectors performed well during the 27 hours long flight.

  7. Magnetorotational dynamo chimeras. The missing link to turbulent accretion disk dynamo models?

    Science.gov (United States)

    Riols, A.; Rincon, F.; Cossu, C.; Lesur, G.; Ogilvie, G. I.; Longaretti, P.-Y.

    2017-02-01

    In Keplerian accretion disks, turbulence and magnetic fields may be jointly excited through a subcritical dynamo mechanisminvolving magnetorotational instability (MRI). This dynamo may notably contribute to explaining the time-variability of various accreting systems, as high-resolution simulations of MRI dynamo turbulence exhibit statistical self-organization into large-scale cyclic dynamics. However, understanding the physics underlying these statistical states and assessing their exact astrophysical relevance is theoretically challenging. The study of simple periodic nonlinear MRI dynamo solutions has recently proven useful in this respect, and has highlighted the role of turbulent magnetic diffusion in the seeming impossibility of a dynamo at low magnetic Prandtl number (Pm), a common regime in disks. Arguably though, these simple laminar structures may not be fully representative of the complex, statistically self-organized states expected in astrophysical regimes. Here, we aim at closing this seeming discrepancy by reporting the numerical discovery of exactly periodic, yet semi-statistical "chimeral MRI dynamo states" which are the organized outcome of a succession of MRI-unstable, non-axisymmetric dynamical stages of different forms and amplitudes. Interestingly, these states, while reminiscent of the statistical complexity of turbulent simulations, involve the same physical principles as simpler laminar cycles, and their analysis further confirms the theory that subcritical turbulent magnetic diffusion impedes the sustainment of an MRI dynamo at low Pm. Overall, chimera dynamo cycles therefore offer an unprecedented dual physical and statistical perspective on dynamos in rotating shear flows, which may prove useful in devising more accurate, yet intuitive mean-field models of time-dependent turbulent disk dynamos. Movies associated to Fig. 1 are available at http://www.aanda.org

  8. 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.

  9. 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.

  10. Immunogenicity of a West Nile virus DIII-cholera toxin A2/B chimera after intranasal delivery.

    Science.gov (United States)

    Tinker, Juliette K; Yan, Jie; Knippel, Reece J; Panayiotou, Panos; Cornell, Kenneth A

    2014-04-22

    West Nile virus (WNV) causes potentially fatal neuroinvasive disease and persists at endemic levels in many parts of the world. Despite advances in our understanding of WNV pathogenesis, there remains a significant need for a human vaccine. The domain III (DIII) region of the WNV envelope protein contains epitopes that are the target of neutralizing antibodies. We have constructed a chimeric fusion of the non-toxic cholera toxin (CT) CTA2/B domains to DIII for investigation as a novel mucosally-delivered WNV vaccine. Purification and assembly of the chimera, as well as receptor-binding and antigen delivery, were verified by western blot, GM1 ELISA and confocal microscopy. Groups of BALB/c mice were immunized intranasally with DIII-CTA2/B, DIII, DIII mixed with CTA2/B, or CTA2/B control, and boosted at 10 days. Analysis of serum IgG after 14 and 45 days revealed that mucosal immunization with DIII-CTA2/B induced significant DIII-specific humoral immunity and drove isotype switching to IgG2a. The DIII-CTA2/B chimera also induced antigen-specific IgM and IgA responses. Bactericidal assays indicate that the DIII-CTA2/B immunized mice produced DIII-specific antibodies that can trigger complement-mediated killing. A dose escalation resulted in increased DIII-specific serum IgG titers on day 45. DIII antigen alone, in the absence of adjuvant, also induced significant systemic responses after intranasal delivery. Our results indicate that the DIII-CTA2/B chimera is immunogenic after intranasal delivery and merits further investigation as a novel WNV vaccine candidate.

  11. High-energy detector

    Science.gov (United States)

    Bolotnikov, Aleksey E [South Setauket, NY; Camarda, Giuseppe [Farmingville, NY; Cui, Yonggang [Upton, NY; James, Ralph B [Ridge, NY

    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.

  12. Equalized near maximum likelihood detector

    OpenAIRE

    2012-01-01

    This paper presents new detector that is used to mitigate intersymbol interference introduced by bandlimited channels. This detector is named equalized near maximum likelihood detector which combines nonlinear equalizer and near maximum likelihood detector. Simulation results show that the performance of equalized near maximum likelihood detector is better than the performance of nonlinear equalizer but worse than near maximum likelihood detector.

  13. 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.

  14. 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/.

  15. An Activin A/BMP2 chimera displays bone healing properties superior to those of BMP2

    Science.gov (United States)

    Yoon, Byung-Hak; Esquivies, Luis; Ahn, Chihoon; Gray, Peter C.; Ye, Sang-kyu; Kwiatkowski, Witek; Choe, Senyon

    2014-01-01

    Recombinant Bone Morphogenetic Protein 2 (rhBMP2) has been used clinically to treat bone fractures in human patients. However, the high doses of rhBMP2 required for a therapeutic response can cause undesirable side effects. Here, we demonstrate that a novel Activin A/BMP2 (AB2) chimera, AB204, promotes osteogenesis and bone healing much more potently and effectively than rhBMP2. Remarkably, 1 month of AB204 treatment completely heals tibial and calvarial defects of critical size in mice at a concentration 10-fold lower than a dose of rhBMP2 that only partially heals the defect. We determine the structure of AB204 to 2.3 Å that reveals a distinct BMP2-like fold in which the Activin A sequence segments confer insensitivity to the BMP2 antagonist Noggin and an affinity for the Activin/BMP type II receptor ActRII that is 100-fold greater than that of BMP2. The structure also led to our identification of a single Activin A-derived amino acid residue which when mutated to the corresponding BMP2 residue resulted in a significant increase in the affinity of AB204 for its type I receptor BMPRIa and a further enhancement in AB204's osteogenic potency. Together, these findings demonstrate that rationally designed AB2 chimeras can provide BMP2 substitutes with enhanced potency for treating non-union bone fractures. PMID:24692083

  16. 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

  17. 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.

  18. An activin A/BMP2 chimera, AB204, displays bone-healing properties superior to those of BMP2.

    Science.gov (United States)

    Yoon, Byung-Hak; Esquivies, Luis; Ahn, Chihoon; Gray, Peter C; Ye, Sang-Kyu; Kwiatkowski, Witek; Choe, Senyon

    2014-09-01

    Recombinant bone morphogenetic protein 2 (rhBMP2) has been used clinically to treat bone fractures in human patients. However, the high doses of rhBMP2 required for a therapeutic response can cause undesirable side effects. Here, we demonstrate that a novel Activin A/BMP2 (AB2) chimera, AB204, promotes osteogenesis and bone healing much more potently and effectively than rhBMP2. Remarkably, 1 month of AB204 treatment completely heals tibial and calvarial defects of critical size in mice at a concentration 10-fold lower than a dose of rhBMP2 that only partially heals the defect. We determine the structure of AB204 to 2.3 Å that reveals a distinct BMP2-like fold in which the Activin A sequence segments confer insensitivity to the BMP2 antagonist Noggin and an affinity for the Activin/BMP type II receptor ActRII that is 100-fold greater than that of BMP2. The structure also led to our identification of a single Activin A-derived amino acid residue, which, when mutated to the corresponding BMP2 residue, resulted in a significant increase in the affinity of AB204 for its type I receptor BMPRIa and a further enhancement in AB204's osteogenic potency. Together, these findings demonstrate that rationally designed AB2 chimeras can provide BMP2 substitutes with enhanced potency for treating non-union bone fractures.

  19. In-cell aggregation of a polyglutamine-containing chimera is a multistep process initiated by the flanking sequence.

    Science.gov (United States)

    Ignatova, Zoya; Thakur, Ashwani K; Wetzel, Ronald; Gierasch, Lila M

    2007-12-14

    Toxicity in amyloid diseases is intimately linked to the nature of aggregates, with early oligomeric species believed to be more cytotoxic than later fibrillar aggregates. Yet mechanistic understanding of how aggregating species evolve with time is currently lacking. We have explored the aggregation process of a chimera composed of a globular protein (cellular retinoic acid-binding protein, CRABP) and huntingtin exon 1 with polyglutamine tracts either above (Q53) or below (Q20) the pathological threshold using Escherichia coli cells as a model intracellular environment. Previously we showed that fusion of the huntingtin exon 1 sequence with >40Q led to structural perturbation and decreased stability of CRABP (Ignatova, Z., and Gierasch, L. M. (2006) J. Biol. Chem. 281, 12959-12967). Here we report that the Q53 chimera aggregates in cells via a multistep process: early stage aggregates are spherical and detergent-soluble, characteristics of prefibrillar aggregates, and appear to be dominated structurally by CRABP, in that they can promote aggregation of a CRABP variant but not oligoglutamine aggregation, and the CRABP domain is relatively sequestered based on its protection from proteolysis. Late stage aggregates appear to be dominated by polyGln; they are fibrillar, detergent-resistant, capable of seeding aggregation of oligoglutamine but not the CRABP variant, and show relative protection of the polyglutamine-exon1 domain from proteolysis. These results point to an evolution of the dominant sequences in intracellular aggregates and may provide molecular insight into origins of toxic prefibrillar aggregates.

  20. Generation of germ-line chimera zebrafish using primordial germ cells isolated from cultured blastomeres and cryopreserved embryoids.

    Science.gov (United States)

    Kawakami, Yutaka; Goto-Kazeto, Rie; Saito, Taiju; Fujimoto, Takafumi; Higaki, Shogo; Takahashi, Yoshiyuki; Arai, Katsutoshi; Yamaha, Etsuro

    2010-01-01

    Primordial germ cells (PGCs) are the only cells in developing embryos with the potential to transmit genetic information to the next generation. In our previous study, a single PGC transplanted into a host differentiated into fertile gametes and produced germ-line chimeras of cyprinid fish, including zebrafish. In this study, we aimed to induce germ-line chimeras by transplanting donor PGCs from various sources (normal embryos at different stages, dissociated blastomeres, embryoids, or embryoids cryopreserved by vitrification) into host blastulae, and compare the migration rates of the PGCs towards the gonadal ridge. Isolated, cultured blastomeres not subject to mesodermal induction were able to differentiate into PGCs that retained their motility. Moreover, these PGCs successfully migrated towards the gonadal ridge of the host and formed viable gametes. Motility depended on developmental stage and culture duration: PGCs obtained at earlier developmental stages and with shorter cultivation periods showed an increased rate of migration to the gonadal ridge. Offspring were obtained from natural spawning between normal females and chimeric males. These results provide the basis for new methods of gene preservation in zebrafish.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Infectious RNA transcripts from Ross River virus cDNA clones and the construction and characterization of defined chimeras with Sindbis virus.

    Science.gov (United States)

    Kuhn, R J; Niesters, H G; Hong, Z; Strauss, J H

    1991-06-01

    We have constructed a full-length cDNA clone of the virulent T48 strain of Ross River virus, a member of the alphavirus genus. Infectious RNA can be transcribed from this clone using SP6 or T7 RNA polymerase. The rescued virus has properties indistinguishable from those of the T48 strain of Ross River virus. We have used this clone, together with a full-length cDNA clone of Sindbis virus, to construct chimeric plasmids in which the 5' and the 3' nontranslated regions of the Sindbis and Ross River genomes were exchanged. The nontranslated regions of the two viral genomes differ in both size and sequence although they maintain specific conserved sequence elements. Virus was recovered from all four chimeras. Chimeras containing heterologous 3' nontranslated regions had replicative efficiencies equal to those of the parents. In contrast, the chimeras containing heterologous 5' nontranslated regions were defective in RNA synthesis and virus production, and the severity of the defect was dependent upon the host. Replication of a virus containing a heterologous 5' nontranslated region may be inefficient due to the formation of defective protein-RNA complexes, whereas, the presumptive complexes formed between host or virus proteins and the 3' nontranslated region to promote RNA synthesis appear to function normally in the chimeras.

  6. 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.

  7. 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.

  8. 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.

  9. Detector Systems at CLIC

    CERN Document Server

    Simon, Frank

    2011-01-01

    The Compact Linear Collider CLIC is designed to deliver e+e- collisions at a center of mass energy of up to 3 TeV. The detector systems at this collider have to provide highly efficient tracking and excellent jet energy resolution and hermeticity for multi-TeV final states with multiple jets and leptons. In addition, the detector systems have to be capable of distinguishing physics events from large beam-induced background at a crossing frequency of 2 GHz. Like for the detector concepts at the ILC, CLIC detectors are based on event reconstruction using particle flow algorithms. The two detector concepts for the ILC, ILD and SID, were adapted for CLIC using calorimeters with dense absorbers limiting leakage through increased compactness, as well as modified forward and vertex detector geometries and precise time stamping to cope with increased background levels. The overall detector concepts for CLIC are presented, with particular emphasis on the main detector and engineering challenges, such as: the ultra-thi...

  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. 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

  12. The PERDaix detector

    Energy Technology Data Exchange (ETDEWEB)

    Bachlechner, Andreas; Beischer, Bastian; Greim, Roman [I. Physikalisches Institut B, RWTH Aachen University, Aachen 52056 (Germany); Kirn, Thomas, E-mail: kirn@physik.rwth-aachen.de [I. Physikalisches Institut B, RWTH Aachen University, Aachen 52056 (Germany); Mai, Carsten; Yearwood, Gregorio Roper; Schael, Stefan; Schug, David; Tholen, Heiner; Wienkenhoever, Jens [I. Physikalisches Institut B, RWTH Aachen University, Aachen 52056 (Germany)

    2012-12-11

    The PERDaix (Proton Electron Radiation Detector Aix-la-Chapelle) detector is designed to measure charged particles in cosmic rays. It can distinguish particle species up to 5 GV rigidity. PERDaix was flown on the BEXUS-11 balloon on 23rd November 2010. The detector has the dimensions of 246 Multiplication-Sign 400 Multiplication-Sign 859 mm{sup 3}, a geometrical acceptance of 32 cm{sup 2}sr, a low weight of 40 kg and a low power consumption of 60 W. The spectrometer consists of a time-of-flight system, a scintillating fiber tracking detector, a permanent magnet and a transition radiation detector. Silicon photomultipliers are used as photodetectors in the time-of-flight and the tracker system.

  13. The PERDaix detector

    Science.gov (United States)

    Bachlechner, Andreas; Beischer, Bastian; Greim, Roman; Kirn, Thomas; Mai, Carsten; Yearwood, Gregorio Roper; Schael, Stefan; Schug, David; Tholen, Heiner; Wienkenhöver, Jens

    2012-12-01

    The PERDaix (Proton Electron Radiation Detector Aix-la-Chapelle) detector is designed to measure charged particles in cosmic rays. It can distinguish particle species up to 5 GV rigidity. PERDaix was flown on the BEXUS-11 balloon on 23rd November 2010. The detector has the dimensions of 246×400×859 mm3, a geometrical acceptance of 32 cm2sr, a low weight of 40 kg and a low power consumption of 60 W. The spectrometer consists of a time-of-flight system, a scintillating fiber tracking detector, a permanent magnet and a transition radiation detector. Silicon photomultipliers are used as photodetectors in the time-of-flight and the tracker system.

  14. ATLAS ITk Pixel detector

    CERN Document Server

    Gemme, Claudia; The ATLAS collaboration

    2016-01-01

    The high luminosity upgrade of the LHC (HL-LHC) in 2026 will provide new challenge to the ATLAS tracker. The current inner detector will be replaced with a whole silicon tracker which will consist of a five barrel layer Pixel detector surrounded by a four barrel layer Strip detector. The expected high radiation level are requiring the development of upgraded silicon sensors as well as new a front-end chip. The dense tracking environment will require finer granularity detectors. The data rates will require new technologies for high bandwidth data transmission and handling. The current status of the HL-LHC ATLA Pixel detector developments as well as the various layout options will be reviewed.

  15. 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.

  16. ATLAS Detector Interface Group

    CERN Multimedia

    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...

  17. Detectors for Tomorrow's Instruments

    Science.gov (United States)

    Moseley, Harvey

    2009-01-01

    Cryogenically cooled superconducting detectors have become essential tools for a wide range of measurement applications, ranging from quantum limited heterodyne detection in the millimeter range to direct searches for dark matter with superconducting phonon detectors operating at 20 mK. Superconducting detectors have several fundamental and practical advantages which have resulted in their rapid adoption by experimenters. Their excellent performance arises in part from reductions in noise resulting from their low operating temperatures, but unique superconducting properties provide a wide range of mechanisms for detection. For example, the steep dependence of resistance with temperature on the superconductor/normal transition provides a sensitive thermometer for calorimetric and bolometric applications. Parametric changes in the properties of superconducting resonators provides a mechanism for high sensitivity detection of submillimeter photons. From a practical point of view, the use of superconducting detectors has grown rapidly because many of these devices couple well to SQUID amplifiers, which are easily integrated with the detectors. These SQUID-based amplifiers and multiplexers have matured with the detectors; they are convenient to use, and have excellent noise performance. The first generation of fully integrated large scale superconducting detection systems are now being deployed. I will discuss the prospects for a new generation of instruments designed to take full advantage of the revolution in detector technology.

  18. Chronic Exposure to Androgenic-Anabolic Steroids Exacerbates Axonal Injury and Microgliosis in the CHIMERA Mouse Model of Repetitive Concussion.

    Directory of Open Access Journals (Sweden)

    Dhananjay R Namjoshi

    Full Text Available Concussion is a serious health concern. Concussion in athletes is of particular interest with respect to the relationship of concussion exposure to risk of chronic traumatic encephalopathy (CTE, a neurodegenerative condition associated with altered cognitive and psychiatric functions and profound tauopathy. However, much remains to be learned about factors other than cumulative exposure that could influence concussion pathogenesis. Approximately 20% of CTE cases report a history of substance use including androgenic-anabolic steroids (AAS. How acute, chronic, or historical AAS use may affect the vulnerability of the brain to concussion is unknown. We therefore tested whether antecedent AAS exposure in young, male C57Bl/6 mice affects acute behavioral and neuropathological responses to mild traumatic brain injury (TBI induced with the CHIMERA (Closed Head Impact Model of Engineered Rotational Acceleration platform. Male C57Bl/6 mice received either vehicle or a cocktail of three AAS (testosterone, nandrolone and 17α-methyltestosterone from 8-16 weeks of age. At the end of the 7th week of treatment, mice underwent two closed-head TBI or sham procedures spaced 24 h apart using CHIMERA. Post-repetitive TBI (rTBI behavior was assessed for 7 d followed by tissue collection. AAS treatment induced the expected physiological changes including increased body weight, testicular atrophy, aggression and downregulation of brain 5-HT1B receptor expression. rTBI induced behavioral deficits, widespread axonal injury and white matter microgliosis. While AAS treatment did not worsen post-rTBI behavioral changes, AAS-treated mice exhibited significantly exacerbated axonal injury and microgliosis, indicating that AAS exposure can alter neuronal and innate immune responses to concussive TBI.

  19. Three dimensional visualization and fractal analysis of mosaic patches in rat chimeras: cell assortment in liver, adrenal cortex and cornea.

    Science.gov (United States)

    Iannaccone, Stephen; Zhou, Yue; Walterhouse, David; Taborn, Greg; Landini, Gabriel; Iannaccone, Philip

    2012-01-01

    The production of organ parenchyma in a rapid and reproducible manner is critical to normal development. In chimeras produced by the combination of genetically distinguishable tissues, mosaic patterns of cells derived from the combined genotypes can be visualized. These patterns comprise patches of contiguously similar genotypes and are different in different organs but similar in a given organ from individual to individual. Thus, the processes that produce the patterns are regulated and conserved. We have previously established that mosaic patches in multiple tissues are fractal, consistent with an iterative, recursive growth model with simple stereotypical division rules. Fractal dimensions of various tissues are consistent with algorithmic models in which changing a single variable (e.g. daughter cell placement after division) switches the mosaic pattern from islands to stripes of cells. Here we show that the spiral pattern previously observed in mouse cornea can also be visualized in rat chimeras. While it is generally held that the pattern is induced by stem cell division dynamics, there is an unexplained discrepancy in the speed of cellular migration and the emergence of the pattern. We demonstrate in chimeric rat corneas both island and striped patterns exist depending on the age of the animal. The patches that comprise the pattern are fractal, and the fractal dimension changes with the age of the animal and indicates the constraint in patch complexity as the spiral pattern emerges. The spiral patterns are consistent with a loxodrome. Such data are likely to be relevant to growth and cell division in organ systems and will help in understanding how organ parenchyma are generated and maintained from multipotent stem cell populations located in specific topographical locations within the organ. Ultimately, understanding algorithmic growth is likely to be essential in achieving organ regeneration in vivo or in vitro from stem cell populations.

  20. Three dimensional visualization and fractal analysis of mosaic patches in rat chimeras: cell assortment in liver, adrenal cortex and cornea.

    Directory of Open Access Journals (Sweden)

    Stephen Iannaccone

    Full Text Available The production of organ parenchyma in a rapid and reproducible manner is critical to normal development. In chimeras produced by the combination of genetically distinguishable tissues, mosaic patterns of cells derived from the combined genotypes can be visualized. These patterns comprise patches of contiguously similar genotypes and are different in different organs but similar in a given organ from individual to individual. Thus, the processes that produce the patterns are regulated and conserved. We have previously established that mosaic patches in multiple tissues are fractal, consistent with an iterative, recursive growth model with simple stereotypical division rules. Fractal dimensions of various tissues are consistent with algorithmic models in which changing a single variable (e.g. daughter cell placement after division switches the mosaic pattern from islands to stripes of cells. Here we show that the spiral pattern previously observed in mouse cornea can also be visualized in rat chimeras. While it is generally held that the pattern is induced by stem cell division dynamics, there is an unexplained discrepancy in the speed of cellular migration and the emergence of the pattern. We demonstrate in chimeric rat corneas both island and striped patterns exist depending on the age of the animal. The patches that comprise the pattern are fractal, and the fractal dimension changes with the age of the animal and indicates the constraint in patch complexity as the spiral pattern emerges. The spiral patterns are consistent with a loxodrome. Such data are likely to be relevant to growth and cell division in organ systems and will help in understanding how organ parenchyma are generated and maintained from multipotent stem cell populations located in specific topographical locations within the organ. Ultimately, understanding algorithmic growth is likely to be essential in achieving organ regeneration in vivo or in vitro from stem cell populations.

  1. Detectors - Electronics; Detecteurs - Electronique

    Energy Technology Data Exchange (ETDEWEB)

    Bregeault, J.; Gabriel, J.L.; Hierle, G.; Lebotlan, P.; Leconte, A.; Lelandais, J.; Mosrin, P.; Munsch, P.; Saur, H.; Tillier, J. [Lab. de Physique Corpusculaire, Caen Univ., 14 (France)

    1998-04-01

    The reports presents the main results obtained in the fields of radiation detectors and associated electronics. In the domain of X-ray gas detectors for the keV range efforts were undertaken to rise the detector efficiency. Multiple gap parallel plate chambers of different types as well as different types of X {yields} e{sup -} converters were tested to improve the efficiency (values of 2.4% at 60 KeV were reached). In the field of scintillators a study of new crystals has been carried out (among which Lutetium orthosilicate). CdTe diode strips for obtaining X-ray imaging were studied. The complete study of a linear array of 8 CdTe pixels has been performed and certified. The results are encouraging and point to this method as a satisfying solution. Also, a large dimension programmable chamber was used to study the influence of temperature on the inorganic scintillators in an interval from -40 deg. C to +150 deg. C. Temperature effects on other detectors and electronic circuits were also investigated. In the report mentioned is also the work carried out for the realization of the DEMON neutron multidetector. For neutron halo experiments different large area Si detectors associated with solid and gas position detectors were realized. In the frame of a contract with COGEMA a systematic study of Li doped glasses was undertaken aiming at replacing with a neutron probe the {sup 3}He counters presently utilized in pollution monitoring. An industrial prototype has been realised. Other studies were related to integrated analog chains, materials for Cherenkov detectors, scintillation probes for experiments on fundamental processes, gas position sensitive detectors, etc. In the field of associated electronics there are mentioned the works related to the multidetector INDRA, data acquisition, software gamma spectrometry, automatic gas pressure regulation in detectors, etc

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Pocked surface neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas (Whitmore Lake, MI); Klann, Raymond (Bolingbrook, IL)

    2003-04-08

    The detection efficiency, or sensitivity, of a neutron detector material such as of Si, SiC, amorphous Si, GaAs, or diamond is substantially increased by forming one or more cavities, or holes, in its surface. A neutron reactive material such as of elemental, or any compound of, .sup.10 B, .sup.6 Li, .sup.6 LiF, U, or Gd is deposited on the surface of the detector material so as to be disposed within the cavities therein. The portions of the neutron reactive material extending into the detector material substantially increase the probability of an energetic neutron reaction product in the form of a charged particle being directed into and detected by the neutron detector material.

  8. Europe plans megaton detector

    CERN Multimedia

    Cartlidge, Edwin

    2004-01-01

    A group of French and Italian particle physicists hopes to carry on the long tradition of building large underground detectors by constructing a device deep under the Alps containing a million tonnes of extremely pure water.

  9. OPAL detector electromagnetic calorimeter

    CERN Multimedia

    1988-01-01

    Half of the electromagnetic calorimeter of the OPAL detector is seen in this photo. This calorimeter consists of 4720 blocks of lead glass. It was used to detect and measure the energy of photons, electrons and positrons by absorbing them.

  10. 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.

  11. The LUX Prototype Detector

    CERN Document Server

    Akerib, D S; Bedikian, S; Bernstein, A; Bolozdynya, A; Bradley, A; Cahn, S; Carr, D; Chapman, J J; Clark, K; Classen, T; Curioni, A; Dahl, C E; Dazeley, S; deViveiros, L; Dragowsky, M; Druszkiewicz, E; Fiorucci, S; Gaitskell, R J; Hall, C; Faham, C; Holbrook, B; Kastens, L; Kazkaz, K; Kwong, J; Lander, R; Leonard, D; Malling, D; Mannino, R; McKinsey, D N; Mei, D; Mock, J; Morii, M; Nikkel, J; Phelps, P; Shutt, T; Skulski, W; Sorensen, P; Spaans, J; Steigler, T; Svoboda, R; Sweany, M; Thomson, J; Tripathi, M; Walsh, N; Webb, R; White, J; Wolfs, F L H; Woods, M; Zhang, C

    2012-01-01

    The LUX (Large Underground Xenon) detector is a two-phase xenon Time Projection Chamber (TPC) designed to search for WIMP-nucleon dark matter interactions. As with all noble element detectors, continuous purification of the detector medium is essential to produce a large ($>$1ms) electron lifetime; this is necessary for efficient measurement of the electron signal which in turn is essential for achieving robust discrimination of signal from background events. In this paper we describe the development of a novel purification system deployed in a prototype detector. The results from the operation of this prototype indicated heat exchange with an efficiency above 94% up to a flow rate of 42 slpm, allowing for an electron drift length greater than 1 meter to be achieved in approximately two days and sustained for the duration of the testing period.

  12. The pixelated detector

    CERN Multimedia

    Sutton, C

    1990-01-01

    "Collecting data as patterns of light or subatomic particles is vitally important in all the sciences. The new generation of solid-state detectors called pixel devices could transform experimental research at all levels" (4 pages).

  13. GRAVITY detector systems

    Science.gov (United States)

    Mehrgan, Leander H.; Finger, Gert; Eisenhauer, Frank; Panduro, Johana

    2016-08-01

    GRAVITY is a second generation instrument for the VLT Interferometer, designed for high-precision narrow-angle astrometry and phase-referenced interferometric imaging in the K-band. It will combine the AO corrected beams of the four VLT telescopes. In total, the GRAVITY instrument uses five eAPD detectors four for the infrared wavefront sensors of each telescope and one for the fringe tracker. In addition two Hawaii2RG arrays are installed, one for the acquisition camera and one for the spectrometer. The SAPHIRA eAPD array is a newly developed near-infrared detector with sub-electron noise performance at frame rates > 1Kfps. For all seven detectors the ESO common controller, NGC, is used. This paper presents an overview and comparison of GRAVITY detector systems and their final performances at the telescope

  14. Hybrid photon detectors

    CERN Document Server

    D'Ambrosio, C

    2003-01-01

    Hybrid photon detectors detect light via vacuum photocathodes and accelerate the emitted photoelectrons by an electric field towards inversely polarized silicon anodes, where they are absorbed, thus producing electron-hole pairs. These, in turn, are collected and generate electronic signals on their ohmic contacts. This review first describes the characteristic properties of the main components of hybrid photon detectors: light entrance windows, photocathodes, and silicon anodes. Then, essential relations describing the trajectories of photoelectrons in electric and magnetic fields and their backscattering from the silicon anodes are derived. Depending on their anode configurations, three families of hybrid photon detectors are presented: hybrid photomultiplier tubes with single anodes for photon counting with high sensitivity and for gamma spectroscopy; multi-anode photon detector tubes with anodes subdivided into square or hexagonal pads for position-sensitive photon detection; imaging silicon pixel array t...

  15. Infrared Detectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The end goal of this project is to develop proof-of-concept infrared detectors which can be integrated in future infrared instruments engaged in remote...

  16. ALICE Forward Multiplicity Detector

    CERN Multimedia

    Christensen, C

    2013-01-01

    The Forward Multiplicity Detector (FMD) extends the coverage for multiplicity of charge particles into the forward regions - giving ALICE the widest coverage of the 4 LHC experiments for these measurements.

  17. Improved CO [lidar detector

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, P.L.; Busch, G.E.; Thompson, D.C.; Remelius, D.K.; Wells, F.D.

    1999-07-18

    A high sensitivity, CO{sub 2} lidar detector, based on recent advances in ultra-low noise, readout integrated circuits (ROIC), is being developed. This detector will combine a high speed, low noise focal plane array (FPA) with a dispersive grating spectrometer. The spectrometer will filter the large background flux, thereby reducing the limiting background photon shot noise. In order to achieve the desired low noise levels, the HgCdTe FPA will be cooled to {approximately}50K. High speed, short pulse operation of the lidar system should enable the detector to operate with the order of a few noise electrons in the combined detector/ ROIC output. Current receiver design concepts will be presented, along with their expected noise performance.

  18. A Chimera Containing CD4+ and CD8+ T-Cell Epitopes of the Leishmania donovani Nucleoside Hydrolase (NH36) Optimizes Cross-Protection against Leishmania amazonesis Infection

    Science.gov (United States)

    Alves-Silva, Marcus Vinícius; Nico, Dirlei; Morrot, Alexandre; Palatnik, Marcos; Palatnik-de-Sousa, Clarisa B.

    2017-01-01

    The Leishmania donovani nucleoside hydrolase (NH36) and NH A34480 of Leishmania amazonensis share 93% of sequence identity. In mice, the NH36 induced protection against visceral leishmaniasis is mediated by a CD4+ T cell response against its C-terminal domain (F3). Besides this CD4+ Th1 response, prevention and cure of L. amazonensis infection require also additional CD8+ and regulatory T-cell responses to the NH36 N-terminal (F1 domain). We investigated if mice vaccination with F1 and F3 domains cloned in tandem, in a recombinant chimera, with saponin, optimizes the vaccine efficacy against L. amazonensis infection above the levels promoted by the two admixed domains or by each domain independently. The chimera induced the highest IgA, IgG, and IgG2a anti-NH36 antibody, IDR, IFN-γ, and IL-10 responses, while TNF-α was more secreted by mice vaccinated with F3 or all F3-contaning vaccines. Additionally, the chimera and the F1 vaccine also induced the highest proportions of CD4+ and CD8+ T cells secreting IL-2, TNF-α, or IFN-γ alone, TNF-α in combination with IL-2 or IFN-γ, and of CD4+ multifunctional cells secreting IL-2, TNF-α, and IFN-γ. Correlating with the immunological results, the strongest reductions of skin lesions sizes were determined by the admixed domains (80%) and by the chimera (84%), which also promoted the most pronounced and significant reduction of the parasite load (99.8%). Thus, the epitope presentation in a recombinant chimera optimizes immunogenicity and efficacy above the levels induced by the independent or admixed F1 and F3 domains. The multiparameter analysis disclosed that the Th1-CD4+ T helper response induced by the chimera is mainly directed against its FRYPRPKHCHTQVA epitope. Additionally, the YPPEFKTKL epitope of F1 induced the second most important CD4+ T cell response, and, followed by the DVAGIVGVPVAAGCT, FMLQILDFYTKVYE, and ELLAITTVVGNQ sequences, also the most potent CD8+ T cell responses and IL-10 secretion. Remarkably

  19. Fiber optic detector

    Energy Technology Data Exchange (ETDEWEB)

    Partin, J.K.; Ward, T.E.; Grey, A.E.

    1990-12-31

    This invention is comprised of a portable fiber optic detector that senses the presence of specific target chemicals by exchanging the target chemical for a fluorescently-tagged antigen that is bound to an antibody which is in turn attached to an optical fiber. Replacing the fluorescently-tagged antigen reduces the fluorescence so that a photon sensing detector records the reduced light level and activates an appropriate alarm or indicator.

  20. Phi factory detector requirements

    Energy Technology Data Exchange (ETDEWEB)

    Arisaka, K.; Atac, M.; Berg, R.; Buchanan, C.; Calvette, M.; Khazin, B.; Kinoshita, K.; Muller, T.; Ohshima, T.; Olsen, S.; Park, J.; Santoni, C.; Shirai, J.; Solodov, E.; Thompson, J.; Triggiani, G.; Ueno, K.; Yamamoto, H.; Detector and Simulation Working Group

    1991-08-01

    We identify the experimental problems and the conditions required for successful phi-factory operation, and show the range of detector parameters which, in conjunction with different machine designs, may meet these conditions. We started by considering, comparing and criticizing the Italian and Novosibirsk designs. With this discussion as a background, we defined the apparent experimental problems and detector constraints. In this article we summarize our understanding. (orig./HSI).

  1. Detector Control System for the ATLAS Forward Proton detector

    CERN Document Server

    Czekierda, Sabina; The ATLAS collaboration

    2017-01-01

    The ATLAS Forward Proton (AFP) is a forward detector using a Roman Pot technique, recently installed in the LHC tunnel. It is aiming at registering protons that were diffractively or electromagnetically scattered in soft and hard processes. Infrastructure of the detector consists of hardware placed both in the tunnel and in the control room USA15 (about 330 meters from the Roman Pots). AFP detector, like the other detectors of the ATLAS experiment, uses the Detector Control System (DCS) to supervise the detector and to ensure its safe and coherent operation, since the incorrect detector performance may influence the physics results. The DCS continuously monitors the detector parameters, subset of which is stored in data bases. Crucial parameters are guarded by alarm system. A detector representation as a hierarchical tree-like structure of well-defined subsystems built with the use of the Finite State Machine (FSM) toolkit allows for overall detector operation and visualization. Every node in the hierarchy is...

  2. Modelling semiconductor pixel detectors

    CERN Document Server

    Mathieson, K

    2001-01-01

    expected after 200 ps in most cases. The effect of reducing the charge carrier lifetime and examining the charge collection efficiency has been utilised to explore how these detectors would respond in a harsh radiation environment. It is predicted that over critical carrier lifetimes (10 ps to 0.1 ns) an improvement of 40 % over conventional detectors can be expected. This also has positive implications for fabricating detectors, in this geometry, from materials which might otherwise be considered substandard. An analysis of charge transport in CdZnTe pixel detectors has been performed. The analysis starts with simulation studies into the formation of contacts and their influence on the internal electric field of planar detectors. The models include a number of well known defect states and these are balanced to give an agreement with a typical experimental I-V curve. The charge transport study extends to the development of a method for studying the effect of charge sharing in highly pixellated detectors. The ...

  3. Gamma ray detector modules

    Science.gov (United States)

    Capote, M. Albert (Inventor); Lenos, Howard A. (Inventor)

    2009-01-01

    A radiation detector assembly has a semiconductor detector array substrate of CdZnTe or CdTe, having a plurality of detector cell pads on a first surface thereof, the pads having a contact metallization and a solder barrier metallization. An interposer card has planar dimensions no larger than planar dimensions of the semiconductor detector array substrate, a plurality of interconnect pads on a first surface thereof, at least one readout semiconductor chip and at least one connector on a second surface thereof, each having planar dimensions no larger than the planar dimensions of the interposer card. Solder columns extend from contacts on the interposer first surface to the plurality of pads on the semiconductor detector array substrate first surface, the solder columns having at least one solder having a melting point or liquidus less than 120 degrees C. An encapsulant is disposed between the interposer circuit card first surface and the semiconductor detector array substrate first surface, encapsulating the solder columns, the encapsulant curing at a temperature no greater than 120 degrees C.

  4. ATLAS Inner Detector (Pixel Detector and Silicon Tracker)

    CERN Multimedia

    ATLAS Outreach

    2006-01-01

    To raise awareness of the basic functions of the Pixel Detector and Silicon Tracker in the ATLAS detector on the LHC at CERN. This colorful 3D animation is an excerpt from the film "ATLAS-Episode II, The Particles Strike Back." Shot with a bug's eye view of the inside of the detector. The viewer is taken on a tour of the inner workings of the detector, seeing critical pieces of the detector and hearing short explanations of how each works.

  5. 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.

  6. Detectors on the drawing board

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    Linear collider detector developers inside and outside CERN are tackling the next generation of detector technology. While their focus has centred on high-energy linear collider detectors, their innovative concepts and designs will be applicable to any future detector.   A simulated event display in one of the new generation detectors. “While the LHC experiments remain the pinnacle of detector technology, you may be surprised to realise that the design and expertise behind them is well over 10 years old,” says Lucie Linssen, CERN’s Linear Collider Detector (LCD) project manager whose group is pushing the envelope of detector design. “The next generation of detectors will have to surpass the achievements of the LHC experiments. It’s not an easy task but, by observing detectors currently in operation and exploiting a decade’s worth of technological advancements, we’ve made meaningful progress.” The LCD team is curr...

  7. Genes encoding chimeras of Neurospora crassa erg-3 and human TM7SF2 proteins fail to complement Neurospora and yeast sterol C-14 reductase mutants

    Indian Academy of Sciences (India)

    A Prakash; Durgadas P Kasbekar

    2002-03-01

    The human gene TM7SF2 encodes a polypeptide (SR-1) with high sequence similarity to sterol C-14 reductase, a key sterol biosynthetic enzyme in fungi, plants and mammals. In Neurospora and yeast this enzyme is encoded by the erg-3 and erg24 genes respectively. In an effort to demonstrate sterol C-14 reductase activity for SR-1 we constructed six recombinant genes coding for chimeras of the Neurospora erg-3 and SR-1 protein sequences and tested them for complementation of the Neurospora erg-3 mutant. To our surprise, all the chimeras failed to complement erg-3. A few of the chimeric proteins were also tested against the yeast erg24 mutant, but again there was no complementation. We discuss some reasons that might account for these unexpected findings.

  8. A large acceptance scintillator detector with wavelength shifting fibre read-out for search of eta-nucleus bound states

    CERN Document Server

    Kilian, K; Kirillov, Da; Kirillov, Di; Kolev, D; Kravcikova, M; Kutsarova, T; Lesiak, M; Lieb, J; Machner, H; Magiera, A; Maier, R; Martinská, G; Nedev, S; Piskunov, N; Prasuhn, D; Prottic, D; Ritman, J; Von Rossen, P; Roy, B J; Shukla, P; Sitnik, I; Siudak, R; Tsenov, R; Ulicny, M; Urbán, J; Vankova, G

    2007-01-01

    A large acceptance scintillator detector with wavelength shifting optical fibre readout has been designed and built to detect the decay particles of $\\eta$-nucleus bound system (the so-called $\\eta$-mesic nuclei), namely, protons and pions. The detector, named as ENSTAR detector, consists of 122 pieces of plastic scintillator of various shapes and sizes, which are arranged in a cylindrical geometry to provide particle identification, energy loss and coarse position information for these particles. A solid angle coverage of $\\sim$95% of total 4$\\pi$ is obtained in the present design of the detector. Monte Carlo phase space calculations performed to simulate the formation and decay of $\\eta$-mesic nuclei suggest that its decay particles, the protons and pions are emitted with an opening angle of 150$^\\circ \\pm 20^\\circ$, and with energies in the range of 25 to 300 MeV and 225 to 450 MeV respectively. The detailed GEANT simulations show that $\\sim$ 80 % of the decay particles (protons and pions) can be detected ...

  9. Niemann-Pick C1 (NPC1/NPC1-like1 Chimeras Define Sequences Critical for NPC1’s Function as a Filovirus Entry Receptor

    Directory of Open Access Journals (Sweden)

    Esther Ndungo

    2012-10-01

    Full Text Available We recently demonstrated that Niemann-Pick C1 (NPC1, a ubiquitous 13-pass cellular membrane protein involved in lysosomal cholesterol transport, is a critical entry receptor for filoviruses. Here we show that Niemann-Pick C1-like1 (NPC1L1, an NPC1 paralog and hepatitis C virus entry factor, lacks filovirus receptor activity. We exploited the structural similarity between NPC1 and NPC1L1 to construct and analyze a panel of chimeras in which NPC1L1 sequences were replaced with cognate sequences from NPC1. Only one chimera, NPC1L1 containing the second luminal domain (C of NPC1 in place of its own, bound to the viral glycoprotein, GP. This engineered protein mediated authentic filovirus infection nearly as well as wild-type NPC1, and more efficiently than did a minimal NPC1 domain C-based receptor recently described by us. A reciprocal chimera, NPC1 containing NPC1L1’s domain C, was completely inactive. Remarkably, an intra-domain NPC1L1-NPC1 chimera bearing only a ~130-amino acid N–terminal region of NPC1 domain C could confer substantial viral receptor activity on NPC1L1. Taken together, these findings account for the failure of NPC1L1 to serve as a filovirus receptor, highlight the central role of the luminal domain C of NPC1 in filovirus entry, and reveal the direct involvement of N–terminal domain C sequences in NPC1’s function as a filovirus receptor.

  10. Rearrangement and junctional-site sequence analyses of T-cell receptor gamma genes in intestinal intraepithelial lymphocytes from murine athymic chimeras.

    Science.gov (United States)

    Whetsell, M; Mosley, R L; Whetsell, L; Schaefer, F V; Miller, K S; Klein, J R

    1991-12-01

    The molecular organization of rearranged T-cell receptor (TCR) gamma genes intraepithelial lymphocytes (IEL) was studied in athymic radiation chimeras and was compared with the organization of gamma gene rearrangements in IEL from thymus-bearing animals by polymerase chain reaction and by sequence analyses of DNA spanning the junction of the variable (V) and joining (J) genes. In both thymus-bearing mice and athymic chimeras, IEL V-J gamma-gene rearrangements occurred for V gamma 1.2, V gamma 2, and V gamma 5 but not for V gamma 3 or V gamma 4. Sequence analyses of cloned V-J polymerase chain reaction-amplified products indicated that in both thymus-bearing mice and athymic chimeras, rearrangement of V gamma 1.2 and V gamma 5 resulted in in-frame as well as out-of-frame genes, whereas nearly all V gamma 2 rearrangements were out of frame from either type of animal. V-segment nucleotide removal occurred in most V gamma 1.2, V gamma 2, and V gamma 5 rearrangements; J-segment nucleotide removal was common in V gamma 1.2 but not in V gamma 2 or V gamma 5 rearrangements. N-segment nucleotide insertions were present in V gamma 1.2, V gamma 2, and V gamma 5 IEL rearrangements in both thymus-bearing mice and athymic chimeras, resulting in a predominant in-frame sequence for V gamma 5 and a predominant out-of-frame sequence for V gamma 2 genes. These findings demonstrate that (i) TCR gamma-gene rearrangement occurs extrathymically in IEL, (ii) rearrangements of TCR gamma genes involve the same V gene regardless of thymus influence; and (iii) the thymus does not determine the degree to which functional or nonfunctional rearrangements occur in IEL.

  11. Human-Mouse Chimeras with Normal Expression and Function Reveal That Major Domain Swapping Is Tolerated by P-Glycoprotein (ABCB1).

    Science.gov (United States)

    Pluchino, Kristen M; Hall, Matthew D; Moen, Janna K; Chufan, Eduardo E; Fetsch, Patricia A; Shukla, Suneet; Gill, Deborah R; Hyde, Stephen C; Xia, Di; Ambudkar, Suresh V; Gottesman, Michael M

    2016-02-23

    The efflux transporter P-glycoprotein (P-gp) plays a vital role in the transport of molecules across cell membranes and has been shown to interact with a panoply of functionally and structurally unrelated compounds. How human P-gp interacts with this large number of drugs has not been well understood, although structural flexibility has been implicated. To gain insight into this transporter's broad substrate specificity and to assess its ability to accommodate a variety of molecular and structural changes, we generated human-mouse P-gp chimeras by the exchange of homologous transmembrane and nucleotide-binding domains. High-level expression of these chimeras by BacMam- and baculovirus-mediated transduction in mammalian (HeLa) and insect cells, respectively, was achieved. There were no detectable differences between wild-type and chimeric P-gp in terms of cell surface expression, ability to efflux the P-gp substrates rhodamine 123, calcein-AM, and JC-1, or to be inhibited by the substrate cyclosporine A and the inhibitors tariquidar and elacridar. Additionally, expression of chimeric P-gp was able to confer a paclitaxel-resistant phenotype to HeLa cells characteristic of P-gp-mediated drug resistance. P-gp ATPase assays and photo-cross-linking with [(125)I]iodoarylazidoprazosin confirmed that transport and biochemical properties of P-gp chimeras were similar to those of wild-type P-gp, although differences in drug binding were detected when human and mouse transmembrane domains were combined. Overall, chimeras with one or two mouse P-gp domains were deemed functionally equivalent to human wild-type P-gp, demonstrating the ability of human P-gp to tolerate major structural changes.

  12. Detectors in Extreme Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Blaj, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Carini, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Carron, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Haller, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hart, P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hasi, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Herrmann, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Kenney, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Segal, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Tomada, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-06

    Free Electron Lasers opened a new window on imaging the motion of atoms and molecules. At SLAC, FEL experiments are performed at LCLS using 120Hz pulses with 1012 - 1013 photons in 10 femtoseconds (billions of times brighter than the most powerful synchrotrons). This extreme detection environment raises unique challenges, from obvious to surprising. Radiation damage is a constant threat due to accidental exposure to insufficiently attenuated beam, focused beam and formation of ice crystals reflecting the beam onto the detector. Often high power optical lasers are also used (e.g., 25TW), increasing the risk of damage or impeding data acquisition through electromagnetic pulses (EMP). The sample can contaminate the detector surface or even produce shrapnel damage. Some experiments require ultra high vacuum (UHV) with strict design, surface contamination and cooling requirements - also for detectors. The setup is often changed between or during experiments with short turnaround times, risking mechanical and ESD damage, requiring work planning, training of operators and sometimes continuous participation of the LCLS Detector Group in the experiments. The detectors used most often at LCLS are CSPAD cameras for hard x-rays and pnCCDs for soft x-rays.

  13. The ZEUS microvertex detector

    CERN Document Server

    Garfagnini, A

    1999-01-01

    A new vertex detector for the ZEUS experiment at HERA will be installed during the 1999-2000 shutdown, for the high-luminosity runs of HERA. It will allow to reconstruct secondary vertex tracks, coming from the decay of long-lived particles with a lifetime of about 10 sup - sup 1 sup 2 s, and improve the global momentum resolution of the tracking system. The interaction region will be surrounded with single-sided silicon strip detectors, with capacitive charge division: three double layers in the central region (600 detectors), and 4 'wheels' in the forward region (112 silicon planes). Due to the high number of readout channels, 512 readout strips per silicon plane in the barrel region and 480 in the forward part, and the large coverage of the vertex detector (almost 1 m long), the front-end electronics has to be placed on top of the detectors and has to be radiation tolerant since doses up to 2 kGy are expected near the interaction region. The HELIX chip has been chosen as analog chip with a low-noise, charg...

  14. Nonequilibrium superconducting detectors

    Science.gov (United States)

    Cristiano, R.; Ejrnaes, M.; Esposito, E.; Lisitskyi, M. P.; Nappi, C.; Pagano, S.; Perez de Lara, D.

    2006-03-01

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  15. Nonequilibrium superconducting detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cristiano, R [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Ejrnaes, M [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); INFN Sezione di Napoli, 80126 Naples (Italy); Esposito, E [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Lisitskyi, M P [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Nappi, C [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Pagano, S [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Dipartimento di Fisica, Universita di Salerno, 84081 Baronissi (Saudi Arabia) (Italy); Perez de Lara, D [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy)

    2006-03-15

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  16. JSATS Detector Field Manual

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eric Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flory, Adam E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lamarche, Brian L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weiland, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-06-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) Detector is a software and hardware system that captures JSATS Acoustic Micro Transmitter (AMT) signals. The system uses hydrophones to capture acoustic signals in the water. This analog signal is then amplified and processed by the Analog to Digital Converter (ADC) and Digital Signal Processor (DSP) board in the computer. This board digitizes and processes the acoustic signal to determine if a possible JSATS tag is present. With this detection, the data will be saved to the computer for further analysis. This document details the features and functionality of the JSATS Detector software. The document covers how to install the software, setup and run the detector software. The document will also go over the raw binary waveform file format and CSV files containing RMS values

  17. Transition Radiation Detectors

    CERN Document Server

    Andronic, A

    2012-01-01

    We review the basic features of transition radiation and how they are used for the design of modern Transition Radiation Detectors (TRD). The discussion will include the various realizations of radiators as well as a discussion of the detection media and aspects of detector construction. With regard to particle identification we assess the different methods for efficient discrimination of different particles and outline the methods for the quantification of this property. Since a number of comprehensive reviews already exist, we predominantly focus on the detectors currently operated at the LHC. To a lesser extent we also cover some other TRDs, which are planned or are currently being operated in balloon or space-borne astro-particle physics experiments.

  18. OPERA: Electronic Detector

    CERN Document Server

    Jollet, C

    2010-01-01

    OPERA is an hybrid detector for the ni-tau appearance search in a direct way, and the Electronic Detectors (ED) have the crucial role of triggerring for the neutrino events and of localizing such an interaction inside the target. Another very important task of the ED is to identify the muon since only a correct matching of such a track with a track in the emulsion connected to the vertex of the event allows to reduce the charm background to the desired level. The ED, fully working since 2006, consist of a target tracker (scintillator strips) and a spectrometer (RPC and drift tubes). The different sub-detectors are de- scribed in the poster, as well as their performance both on Monte Carlo (MC) and real data.

  19. Cryogenic Tracking Detectors

    CERN Multimedia

    Luukka, P R; Tuominen, E M; Mikuz, M

    2002-01-01

    The recent advances in Si and diamond detector technology give hope of a simple solution to the radiation hardness problem for vertex trackers at the LHC. In particular, we have recently demonstrated that operating a heavily irradiated Si detector at liquid nitrogen (LN$_2$) temperature results in significant recovery of Charge Collection Efficiency (CCE). Among other potential benefits of operation at cryogenic temperatures are the use of large low-resistivity wafers, simple processing, higher and faster electrical signal because of higher mobility and drift velocity of carriers, and lower noise of the readout circuit. A substantial reduction in sensor cost could result The first goal of the approved extension of the RD39 program is to demonstrate that irradiation at low temperature in situ during operation does not affect the results obtained so far by cooling detectors which were irradiated at room temperature. In particular we shall concentrate on processes and materials that could significantly reduce th...

  20. Radiation Detectors and Art

    Science.gov (United States)

    Denker, Andrea

    The use of radiation detectors in the analysis of art objects represents a very special application in a true interdisciplinary field. Radiation detectors employed in this field detect, e.g., x-rays, γ-rays, β particles, and protons. Analyzed materials range from stones, metals, over porcelain to paintings. The available nondestructive and noninvasive analytical methods cover a broad range of techniques. Hence, for the sake of brevity, this chapter will concentrate on few techniques: Proton Induced X-ray Emission (PIXE) and Proton Induced γ-ray Emission (PIGE).

  1. Edgeless silicon pad detectors

    Science.gov (United States)

    Perea Solano, B.; Abreu, M. C.; Avati, V.; Boccali, T.; Boccone, V.; Bozzo, M.; Capra, R.; Casagrande, L.; Chen, W.; Eggert, K.; Heijne, E.; Klauke, S.; Li, Z.; Mäki, T.; Mirabito, L.; Morelli, A.; Niinikoski, T. O.; Oljemark, F.; Palmieri, V. G.; Rato Mendes, P.; Rodrigues, S.; Siegrist, P.; Silvestris, L.; Sousa, P.; Tapprogge, S.; Trocmé, B.

    2006-05-01

    We report measurements in a high-energy pion beam of the sensitivity of the edge region in "edgeless" planar silicon pad diode detectors diced through their contact implants. A large surface current on such an edge prevents the normal reverse biasing of the device, but the current can be sufficiently reduced by the use of a suitable cutting method, followed by edge treatment, and by operating the detector at low temperature. The depth of the dead layer at the diced edge is measured to be (12.5±8 stat..±6 syst.) μm.

  2. Edgeless silicon pad detectors

    Energy Technology Data Exchange (ETDEWEB)

    Perea Solano, B. [CERN, CH-1211 Geneva 23 (Switzerland)]. E-mail: blanca.perea.solano@cern.ch; Abreu, M.C. [LIP and University of Algarve, 8000 Faro (Portugal); Avati, V. [CERN, CH-1211 Geneva 23 (Switzerland); Boccali, T. [INFN Sez. di Pisa and Scuola Normale Superiore, Pisa (Italy); Boccone, V. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Bozzo, M. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Capra, R. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Casagrande, L. [INFN Sez. di Roma 2 and Universita di Roma 2, Rome (Italy); Chen, W. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Eggert, K. [CERN, CH-1211 Geneva 23 (Switzerland); Heijne, E. [CERN, CH-1211 Geneva 23 (Switzerland); Klauke, S. [CERN, CH-1211 Geneva 23 (Switzerland); Li, Z. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Maeki, T. [Helsinki Institute of Physics, Helsinki (Finland); Mirabito, L. [CERN, CH-1211 Geneva 23 (Switzerland); Morelli, A. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Niinikoski, T.O. [CERN, CH-1211 Geneva 23 (Switzerland); Oljemark, F. [Helsinki Institute of Physics, Helsinki (Finland); Palmieri, V.G. [Helsinki Institute of Physics, Helsinki (Finland); Rato Mendes, P. [LIP and University of Algarve, 8000 Faro (Portugal); Rodrigues, S. [LIP and University of Algarve, 8000 Faro (Portugal); Siegrist, P. [CERN, CH-1211 Geneva 23 (Switzerland); Silvestris, L. [INFN Sez. Di Bari, Bari (Italy); Sousa, P. [LIP and University of Algarve, 8000 Faro (Portugal); Tapprogge, S. [Helsinki Institute of Physics, Helsinki (Finland); Trocme, B. [Institut de Physique Nucleaire, Villeurbanne (France)

    2006-05-01

    We report measurements in a high-energy pion beam of the sensitivity of the edge region in 'edgeless' planar silicon pad diode detectors diced through their contact implants. A large surface current on such an edge prevents the normal reverse biasing of the device, but the current can be sufficiently reduced by the use of a suitable cutting method, followed by edge treatment, and by operating the detector at low temperature. The depth of the dead layer at the diced edge is measured to be (12.5{+-}8{sub stat.}.{+-}6{sub syst.}) {mu}m.

  3. ALICE Transition Radiation Detector

    CERN Multimedia

    Pachmayer, Y

    2013-01-01

    The Transition Radiation Detector (TRD) is the main electron detector in ALICE. In conduction with the TPC and the ITS, it provides the necessary electron identification capability to study: - Production of light and heavy vector mesons as well as the continuum in the di-electron channel, - Semi leptonic decays of hadrons with open charm and open beauty via the single-electron channel using the displaced vertex information provided by the ITS, - Correlated DD and BB pairs via coincidences of electrons in the central barrel and muons in the forward muon arm, - Jets with high Pτ tracks in one single TRD stack.

  4. Status of the KEDR detector

    CERN Document Server

    Anashin, V V; Baibusinov, B O; Balashov, V; Baldin, E M; Barkov, L M; Barladyan, A K; Barnyakov, M Y; Baru, S E; Bedny, I; Beilin, D M; Blinov, A E; Blinov, V E; Bondarev, D V; Bondar, A E; Buzykaev, A R; Cantoni, P; Chilingarov, A G; Dneprovsky, L V; Eidelman, S I; Epifanov, D A; Frabetti, P L; Gaidarev, P B; Groshev, V R; Karpov, S V; Kiselev, V A; Klimenko, S G; Kolachev, G M; Kononov, S A; Kozlov, V N; Kravchenko, E A; Kulikov, V F; Kurdadze, L M; Kuzmin, A S; Kuznecov, S A; Lanni, F; Lelchuk, M Y; Leontiev, L A; Levichev, E B; Malyshev, V M; Manfredi, P F; Maslennikov, A L; Minakov, G D; Nagaslaev, V P; Naumenkov, A I; Nikitin, S A; Nomerotski, A; Onuchin, A P; Oreshkin, S B; Ovechkin, R; Palombo, F; Peleganchuk, S V; Petrosyan, S S; Pivovarov, S V; Poluektov, A O; Pospelov, G E; Protopopov, I Ya; Re, V; Romanov, L V; Root, N I; Ruban, A A; Savinov, G A; Shamov, A G; Shatilov, D; Shubin, M A; Shusharo, A I; Shwartz, B A; Sidorov, V A; Skovpen, Y I; Smakhtin, V P; Snopkov, R G; Sokolov, A V; Soukharev, A M; Talyshev, A A; Tayursky, V A; Telnov, V I; Tikhonov, Yu A; Todyshev, K Y; Usov, Y V; Vorobyev, A I; Yushkov, A N; Zatcepin, A V; Zhilich, V N

    2002-01-01

    KEDR is a general-purpose detector for experiments at the VEPP-4M e sup + e sup - -collider in the energy range 2E=2.0-12 GeV. All detector subsystems (except the aerogel Cherenkov counters) have been installed into the detector at VEPP-4M. Some preliminary data have been taken in the energy region of the J/PSI meson. The tuning of the detector and the VEPP-4M collider is in progress. Preliminary results on the detector performance are presented. The future experimental program for the KEDR detector is discussed.

  5. Status of the KEDR detector

    Energy Technology Data Exchange (ETDEWEB)

    Anashin, V.V.; Aulchenko, V.M.; Baibusinov, B.O.; Balashov, V.; Baldin, E.M.; Barkov, L.M.; Barladyan, A.K.; Barnyakov, M.Yu.; Baru, S.E.; Bedny, I.V.; Beilin, D.M.; Blinov, A.E.; Blinov, V.E.; Bondarev, D.V.; Bondar, A.E.; Buzykaev, A.R.; Cantoni, P.; Chilingarov, A.G.; Dneprovsky, L.V.; Eidelman, S.I.; Epifanov, D.A.; Frabetti, P.L.; Gaidarev, P.B.; Groshev, V.R.; Karpov, S.V.; Kiselev, V.A.; Klimenko, S.G.; Kolachev, G.M.; Kononov, S.A.; Kozlov, V.N.; Kravchenko, E.A.; Kulikov, V.F.; Kurdadze, L.M.; Kuzmin, A.S.; Kuznecov, S.A.; Lanni, F.; Lelchuk, M.Yu.; Leontiev, L.A.; Levichev, E.B.; Malyshev, V.M.; Manfredi, P.F.; Maslennikov, A.L.; Minakov, G.D.; Nagaslaev, V.P.; Naumenkov, A.; Nikitin, S.A.; Nomerotsky, A.; Onuchin, A.P.; Oreshkin, S.B.; Ovechkin, R.; Palombo, F.; Peleganchuk, S.V.; Petrosyan, S.S.; Pivovarov, S.V.; Poluektov, A.O.; Pospelov, G.E.; Protopopov, I.Ya.; Re, V.; Romanov, L.V.; Root, N.I.; Ruban, A.A.; Savinov, G.A.; Shamov, A.G.; Shatilov, D.; Shubin, M.A.; Shusharo, A.I.; Shwartz, B.A.; Sidorov, V.A.; Skovpen, Yu.I.; Smakhtin, V.P.; Snopkov, R.G.; Sokolov, A.V.; Soukharev, A.M.; Talyshev, A.A.; Tayursky, V.A.; Telnov, V.I.; Tikhonov, Yu.A. E-mail: tikhonov@cppm.in2p3.fr; Todyshev, K.Yu.; Usov, Yu.V.; Vorobyev, A.I.; Yushkov, A.N.; Zatcepin, A.V.; Zhilich, V.N

    2002-02-01

    KEDR is a general-purpose detector for experiments at the VEPP-4M e{sup +}e{sup -}-collider in the energy range 2E=2.0-12 GeV. All detector subsystems (except the aerogel Cherenkov counters) have been installed into the detector at VEPP-4M. Some preliminary data have been taken in the energy region of the J/{psi} meson. The tuning of the detector and the VEPP-4M collider is in progress. Preliminary results on the detector performance are presented. The future experimental program for the KEDR detector is discussed.

  6. The Upgraded D0 detector

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, D.L.; Adams, M.; Adams, T.; Agelou, M.; Agram, J.-L.; Ahmed, S.N.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G.A.; Anastasoaie, M.; Andeen, T.; Anderson, J.T.; Anderson, S.; /Buenos Aires U. /Rio de Janeiro, CBPF /Sao Paulo, IFT /Alberta U.

    2005-07-01

    The D0 experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to D0.

  7. The Upgraded D0 Detector

    CERN Document Server

    Abazov, V M; Abolins, M; Acharya, B S; Adams, D L; Adams, M; Adams, T; Agelou, M; Agram, J L; Ahmed, S N; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Andeen, T; Anderson, J T; Anderson, S; Andrieu, B; Angstadt, R; Anosov, V; Arnoud, Y; Arov, M; Askew, A; Åsman, B; Assis-Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Babukhadia, L; Bacon, Trevor C; Badaud, F; Baden, A; Baffioni, S; Bagby, L; Baldin, B; Balm, P W; Banerjee, P; Banerjee, S; Barberis, E; Bardon, O; Barg, W; Bargassa, P; Baringer, P; Barnes, C; Barreto, J; Bartlett, J F; Bassler, U; Bhattacharjee, M; Baturitsky, M A; Bauer, D; Bean, A; Baumbaugh, B; Beauceron, S; Begalli, M; Beaudette, F; Begel, M; Bellavance, A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Besson, A; Beuselinck, R; Beutel, D; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Binder, M; Biscarat, C; Bishoff, A; Black, K M; Blackler, I; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Blumenschein, U; Bockenthein, E; Bodyagin, V; Böhnlein, A; Boeriu, O; Bolton, T A; Bonamy, P; Bonifas, D; Borcherding, F; Borissov, G; Bos, K; Bose, T; Boswell, C; Bowden, M; Brandt, A; Briskin, G; Brock, R; Brooijmans, G; Bross, A; Buchanan, N J; Buchholz, D; Bühler, M; Büscher, V; Burdin, S; Burke, S; Burnett, T H; Busato, E; Buszello, C P; Butler, D; Butler, J M; Cammin, J; Caron, S; Bystrický, J; Canal, L; Canelli, F; Carvalho, W; Casey, B C K; Casey, D; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chapin, D; Charles, F; Cheu, E; Chevalier, L; Chi, E; Chiche, R; Cho, D K; Choate, R; Choi, S; Choudhary, B; Chopra, S; Christenson, J H; Christiansen, T; Christofek, L; Churin, I; Cisko, G; Claes, D; Clark, A R; Clement, B; Clément, C; Coadou, Y; Colling, D J; Coney, L; Connolly, B; Cooke, M; Cooper, W E; Coppage, D; Corcoran, M; Coss, J; Cothenet, A; Cousinou, M C; Cox, B; Crepe-Renaudin, S; Cristetiu, M; Cummings, M A C; Cutts, D; Da Motta, H; Das, M; Davies, B; Davies, G; Davis, G A; Davis, W; De, K; de Jong, P; De Jong, S J; De La Cruz-Burelo, E; de La Taille, C; De Oliveira Martins, C; Dean, S; Degenhardt, J D; Déliot, F; Delsart, P A; Del Signore, K; De Maat, R; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doets, M; Doidge, M; Dong, H; Doulas, S; Dudko, L V; Duflot, L; Dugad, S R; Duperrin, A; Dvornikov, O; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Edwards, T; Ellison, J; Elmsheuser, J; Eltzroth, J T; Elvira, V D; Eno, S; Ermolov, P; Eroshin, O V; Estrada, J; Evans, D; Evans, H; Evdokimov, A; Evdokimov, V N; Fagan, J; Fast, J; Fatakia, S N; Fein, D; Feligioni, L; Ferapontov, A V; Ferbel, T; Ferreira, M J; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fleck, I; Fitzpatrick, T; Flattum, E; Fleuret, F; Flores, R; Foglesong, J; Fortner, M; Fox, H; Franklin, C; Freeman, W; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Gao, M; García, C; García-Bellido, A; Gardner, J; Gavrilov, V; Gay, A; Gay, P; Gelé, D; Gelhaus, R; Genser, K; Gerber, C E; Gershtein, Yu; Gillberg, D; Geurkov, G; Ginther, G; Gobbi, B; Goldmann, K; Golling, T; Gollub, N; Golovtsov, V L; Gómez, B; Gómez, G; Gómez, R; Goodwin, R W; Gornushkin, Y; Gounder, K; Goussiou, A; Graham, D; Graham, G; Grannis, P D; Gray, K; Greder, S; Green, D R; Green, J; Green, J A; Greenlee, H; Greenwood, Z D; Gregores, E M; Grinstein, S; Gris, P; Grivaz, J F; Groer, L; Grünendahl, S; Grünewald, M W; Gu, W; Guglielmo, J; Sen-Gupta, A; Gurzhev, S N; Gutíerrez, G; Gutíerrez, P; Haas, A; Hadley, N J; Haggard, E; Haggerty, H; Hagopian, S; Hall, I; Hall, R E; Han, C; Han, L; Hance, R; Hanagaki, K; Hanlet, P; Hansen, S; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, C; Hays, J; Hazen, E; Hebbeker, T; Hebert, C; Hedin, D; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hong, S J; Hooper, R; Hou, S; Houben, P; Hu, Y; Huang, J; Huang, Y; Hynek, V; Huffman, D; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jacquier, Y; Jaffré, M; Jain, S; Jain, V; Jakobs, K; Jayanti, R; Jenkins, A; Jesik, R; Jiang, Y; Johns, K; Johnson, M; Johnson, P; Jonckheere, A; Jonsson, P; Jöstlein, H; Jouravlev, N I; Juárez, M; Juste, A; Kaan, A P; Kado, M; Käfer, D; Kahl, W; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J; Kalmani, S D; Karmanov, D; Kasper, J; Katsanos, I; Kau, D; Kaur, R; Ke, Z; Kehoe, R; Kermiche, S; Kesisoglou, S; Khanov, A; Kharchilava, A I; Kharzheev, Yu M; Kim, H; Kim, K H; Kim, T J; Kirsch, N; Klima, B; Klute, M; Kohli, J M; Konrath, J P; Komissarov, E V; Kopal, M; Korablev, V M; Kostritskii, A V; Kotcher, J; Kothari, B; Kotwal, A V; Koubarovsky, A; Kozelov, A V; Kozminski, J; Kryemadhi, A; Kuznetsov, O; Krane, J; Kravchuk, N; Krempetz, K; Krider, J; Krishnaswamy, M R; Krzywdzinski, S; Kubantsev, M A; Kubinski, R; Kuchinsky, N; Kuleshov, S; Kulik, Y; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Kuznetsov, V E; Kwarciany, R; Lager, S; Lahrichi, N; Landsberg, G L; Larwill, M; Laurens, P; Lavigne, B; Lazoflores, J; Le Bihan, A C; Le Meur, G; Lebrun, P; Lee, S W; Lee, W M; Leflat, A; Leggett, C; Lehner, F; Leitner, R; Leonidopoulos, C; Lévêque, J; Lewis, P; Li, J; Li, Q Z; Li, X; Lima, J G R; Lincoln, D; Lindenmeyer, C; Linn, S L; Linnemann, J; Lipaev, V V; Lipton, R; Litmaath, M; Lizarazo, J; Lobo, L; Lobodenko, A; Lokajícek, M; Lounis, A; Love, P; Lü, J; Lubatti, H J; Lucotte, A; Lueking, L; Luo, C; Lynker, M; Lyon, A L; Machado, E; Maciel, A K A; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Magnan, A M; Maity, M; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Manakov, V; Mao, H S; Maravin, Y; Markley, D; Markus, M; Marshall, T; Martens, M; Martin, M; Martin-Chassard, G; Mattingly, S E K; Matulik, M; Mayorov, A A; McCarthy, R; McCroskey, R; McKenna, M; McMahon, T; Meder, D; Melanson, H L; Melnitchouk, A S; Mendes, A; Mendoza, D; Mendoza, L; Meng, X; Merekov, Y P; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Michaut, M; Miao, C; Miettinen, H; Mihalcea, D; Mikhailov, V; Miller, D; Mitrevski, J; Mokhov, N; Molina, J; Mondal, N K; Montgomery, H E; Moore, R W; Moulik, T; Muanza, G S; Mostafa, M; Moua, S; Mulders, M; Mundim, L; Mutaf, Y D; Nagaraj, P; Nagy, E; Naimuddin, M; Nang, F; Narain, M; Narasimhan, V S; Narayanan, A; Naumann, N A; Neal, H A; Negret, J P; Nelson, S; Neuenschwander, R T; Neustroev, P; Nöding, C; Nomerotski, A; Novaes, S F; Nozdrin, A; Nunnemann, T; Nurczyk, A; Nurse, E; O'Dell, V; O'Neil, D C; Oguri, V; Olis, D; Oliveira, N; Olivier, B; Olsen, J; Oshima, N; Oshinowo, B O; Oteroy-Garzon, G J; Padley, P; Papageorgiou, K; Parashar, N; Park, J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Perea, P M; Pérez, E; Peters, O; Petroff, P; Petteni, M; Phaf, L; Piegaia, R; Pleier, M A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M E; Pompos, A; Polosov, P; Pope, B G; Popkov, E; Porokhovoy, S; Prado da Silva, W L; Pritchard, W; Prokhorov, I; Prosper, H B; Protopopescu, S D; Przybycien, M B; Qian, J; Quadt, A; Quinn, B; Ramberg, E; Ramirez-Gomez, R; Rani, K J; Ranjan, K; Rao, M V S; Rapidis, P A; Rapisarda, S; Raskowski, J; Ratoff, P N; Ray, R E; Reay, N W; Rechenmacher, R; Reddy, L V; Regan, T; Renardy, J F; Reucroft, S; Rha, J; Ridel, M; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F K; Robinson, S; Rodrigues, R F; Roco, M T; Rotolo, C; Royon, C; Rubinov, P; Ruchti, R; Rucinski, R; Rud, V I; Rusakovich, N; Russo, P; Sabirov, B; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Satyanarayana, B; Savage, G; Sawyer, L; Scanlon, T; Schaile, A D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schmitt, C; Schwanenberger, C; Schukin, A A; Schwartzman, A; Schwienhorst, R; Sen-Gupta, S; Severini, H; Shabalina, E; Shamim, M; Shankar, H C; Shary, V; Shchukin, A A; Sheahan, P; Shephard, W D; Shivpuri, R K; Shishkin, A A; Shpakov, D; Shupe, M; Sidwell, R A; Simák, V; Sirotenko, V I; Skow, D; Skubic, P L; Slattery, P F; Smith, D E; Smith, R P; Smolek, K; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Song, X; Song, Y; Sonnenschein, L; Sopczak, A; Sorin, V; Sosebee, M; Soustruznik, K; Souza, M; Spartana, N; Spurlock, B; Stanton, N R; Stark, J; Steele, J; Stefanik, A; Steinberg, J L; Steinbruck, G; Stevenson, K; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strang, M A; Strauss, M; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Sznajder, A; Talby, M; Tentindo-Repond, S; Tamburello, P; Taylor, W; Telford, P; Temple, J; Terentyev, N K; Teterin, V; Thomas, E; Thompson, J; Thooris, B; Titov, M; Toback, D; Tokmenin, V V; Tolian, C; Tomoto, M; Tompkins, D; Toole, T; Torborg, J; Touze, F; Towers, S; Trefzger, T; Trincaz-Duvoid, S; Trippe, T G; Tsybychev, D; Tuchming, B; Tully, C; Turcot, A S; Tuts, P M; Utes, M; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; Van den Berg, P J; Van Gemmeren, P; Van Kooten, R; Van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A H; Vasilyev, I A; Vaupel, M; Vaz, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Vigneault, M; Villeneuve-Séguier, F; Vishwanath, P R; Vlimant, J R; Von Törne, E; Vorobyov, A; Vreeswijk, M; Vu-Anh, T; Vysotsky, V S; Wahl, H D; Walker, R; Wallace, N; Wang, L; Wang, Z M; Warchol, J; Warsinsky, M; Watts, G; Wayne, M; Weber, M; Weerts, H; Wegner, M; Wermes, N; Wetstein, M; White, A; White, V; Whiteson, D; Wicke, D; Wijnen, T A M; Wijngaarden, D A; Wilcer, N; Willutzki, H; Wilson, G W; Wimpenny, S J; Wittlin, J; Wlodek, T; Wobisch, M; Womersley, J; Wood, D R; Wyatt, T R; Wu, Z; Xie, Y; Xu, Q; Xuan, N; Yacoob, S; Yamada, R; Yan, M; Yarema, R J; Yasuda, T; Yatsunenko, Y A; Yen, Y; Yip, K; Yoo, H D; Yoffe, F; Youn, S W; Yu, J; Yurkewicz, A; Zabi, A; Zanabria, M; Zatserklyaniy, A; Zdrazil, M; Zeitnitz, C; Zhang, B; Zhang, D; Zhang, X; Zhao, T; Zhao, Z; Zheng, H; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zitoun, R; Zmuda, T; Zutshi, V; Zviagintsev, S; Zverev, E G; Zylberstejn, A

    2005-01-01

    The D0 experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to D0.

  8. Fast Detector Simulation Using Lelaps, Detector Descriptions in GODL

    Energy Technology Data Exchange (ETDEWEB)

    Langeveld, Willy; /SLAC

    2005-07-06

    Lelaps is a fast detector simulation program which reads StdHep generator files and produces SIO or LCIO output files. It swims particles through detectors taking into account magnetic fields, multiple scattering and dE/dx energy loss. It simulates parameterized showers in EM and hadronic calorimeters and supports gamma conversions and decays. In addition to three built-in detector configurations, detector descriptions can also be read from files in the new GODL file format.

  9. Interspecies avian brain chimeras reveal that large brain size differences are influenced by cell-interdependent processes.

    Science.gov (United States)

    Chen, Chun-Chun; Balaban, Evan; Jarvis, Erich D

    2012-01-01

    Like humans, birds that exhibit vocal learning have relatively delayed telencephalon maturation, resulting in a disproportionately smaller brain prenatally but enlarged telencephalon in adulthood relative to vocal non-learning birds. To determine if this size difference results from evolutionary changes in cell-autonomous or cell-interdependent developmental processes, we transplanted telencephala from zebra finch donors (a vocal-learning species) into Japanese quail hosts (a vocal non-learning species) during the early neural tube stage (day 2 of incubation), and harvested the chimeras at later embryonic stages (between 9-12 days of incubation). The donor and host tissues fused well with each other, with known major fiber pathways connecting the zebra finch and quail parts of the brain. However, the overall sizes of chimeric finch telencephala were larger than non-transplanted finch telencephala at the same developmental stages, even though the proportional sizes of telencephalic subregions and fiber tracts were similar to normal finches. There were no significant changes in the size of chimeric quail host midbrains, even though they were innervated by the physically smaller zebra finch brain, including the smaller retinae of the finch eyes. Chimeric zebra finch telencephala had a decreased cell density relative to normal finches. However, cell nucleus size differences between each species were maintained as in normal birds. These results suggest that telencephalic size development is partially cell-interdependent, and that the mechanisms controlling the size of different brain regions may be functionally independent.

  10. Designer Nodal/BMP2 Chimeras Mimic Nodal Signaling, Promote Chondrogenesis, and Reveal a BMP2-like Structure

    Science.gov (United States)

    Esquivies, Luis; Blackler, Alissa; Peran, Macarena; Rodriguez-Esteban, Concepcion; Izpisua Belmonte, Juan Carlos; Booker, Evan; Gray, Peter C.; Ahn, Chihoon; Kwiatkowski, Witek; Choe, Senyon

    2014-01-01

    Nodal, a member of the TGF-β superfamily, plays an important role in vertebrate and invertebrate early development. The biochemical study of Nodal and its signaling pathway has been a challenge, mainly because of difficulties in producing the protein in sufficient quantities. We have developed a library of stable, chemically refoldable Nodal/BMP2 chimeric ligands (NB2 library). Three chimeras, named NB250, NB260, and NB264, show Nodal-like signaling properties including dependence on the co-receptor Cripto and activation of the Smad2 pathway. NB250, like Nodal, alters heart looping during the establishment of embryonic left-right asymmetry, and both NB250 and NB260, as well as Nodal, induce chondrogenic differentiation of human adipose-derived stem cells. This Nodal-induced differentiation is shown to be more efficient than BPM2-induced differentiation. Interestingly, the crystal structure of NB250 shows a backbone scaffold similar to that of BMP2. Our results show that these chimeric ligands may have therapeutic implications in cartilage injuries. PMID:24311780

  11. Interspecies avian brain chimeras reveal that large brain size differences are influenced by cell-interdependent processes.

    Directory of Open Access Journals (Sweden)

    Chun-Chun Chen

    Full Text Available Like humans, birds that exhibit vocal learning have relatively delayed telencephalon maturation, resulting in a disproportionately smaller brain prenatally but enlarged telencephalon in adulthood relative to vocal non-learning birds. To determine if this size difference results from evolutionary changes in cell-autonomous or cell-interdependent developmental processes, we transplanted telencephala from zebra finch donors (a vocal-learning species into Japanese quail hosts (a vocal non-learning species during the early neural tube stage (day 2 of incubation, and harvested the chimeras at later embryonic stages (between 9-12 days of incubation. The donor and host tissues fused well with each other, with known major fiber pathways connecting the zebra finch and quail parts of the brain. However, the overall sizes of chimeric finch telencephala were larger than non-transplanted finch telencephala at the same developmental stages, even though the proportional sizes of telencephalic subregions and fiber tracts were similar to normal finches. There were no significant changes in the size of chimeric quail host midbrains, even though they were innervated by the physically smaller zebra finch brain, including the smaller retinae of the finch eyes. Chimeric zebra finch telencephala had a decreased cell density relative to normal finches. However, cell nucleus size differences between each species were maintained as in normal birds. These results suggest that telencephalic size development is partially cell-interdependent, and that the mechanisms controlling the size of different brain regions may be functionally independent.

  12. Detection of Hepatitis C core antibody by dual-affinity yeast chimera and smartphone-based electrochemical sensing.

    Science.gov (United States)

    Aronoff-Spencer, Eliah; Venkatesh, A G; Sun, Alex; Brickner, Howard; Looney, David; Hall, Drew A

    2016-12-15

    Yeast cell lines were genetically engineered to display Hepatitis C virus (HCV) core antigen linked to gold binding peptide (GBP) as a dual-affinity biobrick chimera. These multifunctional yeast cells adhere to the gold sensor surface while simultaneously acting as a "renewable" capture reagent for anti-HCV core antibody. This streamlined functionalization and detection strategy removes the need for traditional purification and immobilization techniques. With this biobrick construct, both optical and electrochemical immunoassays were developed. The optical immunoassays demonstrated detection of anti-HCV core antibody down to 12.3pM concentrations while the electrochemical assay demonstrated higher binding constants and dynamic range. The electrochemical format and a custom, low-cost smartphone-based potentiostat ($20 USD) yielded comparable results to assays performed on a state-of-the-art electrochemical workstation. We propose this combination of synthetic biology and scalable, point-of-care sensing has potential to provide low-cost, cutting edge diagnostic capability for many pathogens in a variety of settings.

  13. Tracking Neospora caninum parasites using chimera monoclonal antibodies against its surface antigen-related sequences (rNcSRS2).

    Science.gov (United States)

    Dong, Jinhua; Otsuki, Takahiro; Kato, Tatsuya; Park, Enoch Y

    2014-03-01

    Neosporosis, an infectious disease of cattle and dogs, causes an abortion in cattle, which has a major damage on the dairy industry worldwide. Tracking of Neospora caninum parasite that is responsible for neosporosis is required for the prevention of this infectious disease. We developed three chimera monoclonal antibodies consist of variable regions of murine antibody and constant regions of human antibody against N. caninum. Recombinant surface antigen-related sequence 2 (rNcSRS2) of N. caninum was expressed in silkworm larvae, and immunized in mice to obtain phage displaying antibody library. Through three rounds of selection, three antibodies, A6, E1 and H3, were isolated and bound to rNcSRS2 with nanomolar to micromolar affinity. In immunofluorescent staining assays, A6 and E1 bound to N. caninum strain Nc-Liv, demonstrating a successful tracking of the parasite. H3 clone bound to rNcSRS2 but not to a truncated protein without glycosylphosphatidylinositol (GPI) anchor domain in the carboxyl terminal. Amino acid sequences of A6 and E1 were similar, but that of H3 differed in the CDR-H1 region, which might be the reason of their difference of affinity. These antibodies are thought to be useful for prevention of cattle from neosporosis.

  14. Chimeras Reveal a Single Lipid-Interface Residue that Controls MscL Channel Kinetics as well as Mechanosensitivity

    Directory of Open Access Journals (Sweden)

    Li-Min Yang

    2013-02-01

    Full Text Available MscL, the highly conserved bacterial mechanosensitive channel of large conductance, serves as an osmotic “emergency release valve,” is among the best-studied mechanosensors, and is a paradigm of how a channel senses and responds to membrane tension. Although all homologs tested thus far encode channel activity, many show functional differences. We tested Escherichia coli and Staphylococcus aureus chimeras and found that the periplasmic region of the protein, particularly E. coli I49 and the equivalent S. aureus F47 at the periplasmic lipid-aqueous interface of the first transmembrane domain, drastically influences both the open dwell time and the threshold of channel opening. One mutant shows a severe hysteresis, confirming the importance of this residue in determining the energy barriers for channel gating. We propose that this site acts similarly to a spring for a clasp knife, adjusting the resistance for obtaining and stabilizing an open or closed channel structure.

  15. Design, synthesis and DNA interactions of a chimera between a platinum complex and an IHF mimicking peptide.

    Science.gov (United States)

    Rao, Harita; Damian, Mariana S; Alshiekh, Alak; Elmroth, Sofi K C; Diederichsen, Ulf

    2015-12-28

    Conjugation of metal complexes with peptide scaffolds possessing high DNA binding affinity has shown to modulate their biological activities and to enhance their interaction with DNA. In this work, a platinum complex/peptide chimera was synthesized based on a model of the Integration Host Factor (IHF), an architectural protein possessing sequence specific DNA binding and bending abilities through its interaction with a minor groove. The model peptide consists of a cyclic unit resembling the minor grove binding subdomain of IHF, a positively charged lysine dendrimer for electrostatic interactions with the DNA phosphate backbone and a flexible glycine linker tethering the two units. A norvaline derived artificial amino acid was designed to contain a dimethylethylenediamine as a bidentate platinum chelating unit, and introduced into the IHF mimicking peptides. The interaction of the chimeric peptides with various DNA sequences was studied by utilizing the following experiments: thermal melting studies, agarose gel electrophoresis for plasmid DNA unwinding experiments, and native and denaturing gel electrophoresis to visualize non-covalent and covalent peptide-DNA adducts, respectively. By incorporation of the platinum metal center within the model peptide mimicking IHF we have attempted to improve its specificity and DNA targeting ability, particularly towards those sequences containing adjacent guanine residues.

  16. First ALICE detectors installed!

    CERN Document Server

    2006-01-01

    Detectors to track down penetrating muon particles are the first to be placed in their final position in the ALICE cavern. The Alice muon spectrometer: in the foreground the trigger chamber is positioned in front of the muon wall, with the dipole magnet in the background. After the impressive transport of its dipole magnet, ALICE has begun to fill the spectrometer with detectors. In mid-July, the ALICE muon spectrometer team achieved important milestones with the installation of the trigger and the tracking chambers of the muon spectrometer. They are the first detectors to be installed in their final position in the cavern. All of the eight half planes of the RPCs (resistive plate chambers) have been installed in their final position behind the muon filter. The role of the trigger detector is to select events containing a muon pair coming, for instance, from the decay of J/ or Y resonances. The selection is made on the transverse momentum of the two individual muons. The internal parts of the RPCs, made o...

  17. Superconducting Single Photon Detectors

    NARCIS (Netherlands)

    Dorenbos, S.N.

    2011-01-01

    This thesis is about the development of a detector for single photons, particles of light. New techniques are being developed that require high performance single photon detection, such as quantum cryptography, single molecule detection, optical radar, ballistic imaging, circuit testing and fluoresc

  18. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2012-01-01

    The RPC system is operating with a very high uptime, an average chamber efficiency of about 95% and an average cluster size around 1.8. The average number of active channels is 97.7%. Eight chambers are disconnected and forty are working in single-gap mode due to high-voltage problems. The total luminosity lost due to RPCs in 2012 is 88.46 pb–1. One of the main goals of 2012 was to improve the stability of the endcap trigger that is strongly correlated to the performances of the detector, due to the 3-out-3 trigger logic. At beginning of 2011 the instability of the detector efficiency was about 10%. Detailed studies found that this was mainly due to the strong correlation between the performance of the detector and the atmospheric pressure (P). Figure XXY shows the linear correlation between the average cluster size of the endcap chamber versus P. This effect is expected for gaseous detectors and can be reduced by correcting the applied high-voltage working point (HVapp) according to the followi...

  19. ALICE Silicon Pixel Detector

    CERN Multimedia

    Manzari, V

    2013-01-01

    The Silicon Pixel Detector (SPD) forms the innermost two layers of the 6-layer barrel Inner Tracking System (ITS). The SPD plays a key role in the determination of the position of the primary collision and in the reconstruction of the secondary vertices from particle decays.

  20. Sensitive hydrogen leak detector

    Science.gov (United States)

    Myneni, Ganapati Rao

    1999-01-01

    A sensitive hydrogen leak detector system using passivation of a stainless steel vacuum chamber for low hydrogen outgassing, a high compression ratio vacuum system, a getter operating at 77.5 K and a residual gas analyzer as a quantitative hydrogen sensor.

  1. B-factory detectors

    CERN Document Server

    Marlow, D R

    2002-01-01

    The designs of the recently commissioned BaBar and Belle B-Factory detectors are described. The discussion is organized around the methods and instruments used to detect the so-called gold-plated-mode B sup 0->J/PSI K sub S decays and related modes.

  2. Pixel detector insertion

    CERN Multimedia

    CMS

    2015-01-01

    Insertion of the Pixel Tracker, the 66-million-channel device used to pinpoint the vertex of each colliding proton pair, located at the heart of the detector. The geometry of CMS is a cylinder lying on its side (22 meters long and 15 meters high in dia

  3. The CLIC Vertex Detector

    CERN Document Server

    Dannheim, D

    2015-01-01

    The precision physics needs at TeV-scale linear electron-positron colliders (ILC and CLIC) require a vertex-detector system with excellent flavour-tagging capabilities through a meas- urement of displaced vertices. This is essential, for example, for an explicit measurement of the Higgs decays to pairs of b-quarks, c-quarks and gluons. Efficient identification of top quarks in the decay t → W b will give access to the ttH-coupling measurement. In addition to those requirements driven by physics arguments, the CLIC bunch structure calls for hit tim- ing at the few-ns level. As a result, the CLIC vertex-detector system needs to have excellent spatial resolution, full geometrical coverage extending to low polar angles, extremely low material budget, low occupancy facilitated by time-tagging, and sufficient heat removal from sensors and readout. These considerations challenge current technological limits. A detector concept based on hybrid pixel-detector technology is under development for the CLIC ver- tex det...

  4. High-resolution ionization detector and array of such detectors

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas S. (Ypsilanti, MI); Rojeski, Ronald A. (Pleasanton, CA)

    2001-01-16

    A high-resolution ionization detector and an array of such detectors are described which utilize a reference pattern of conductive or semiconductive material to form interaction, pervious and measurement regions in an ionization substrate of, for example, CdZnTe material. The ionization detector is a room temperature semiconductor radiation detector. Various geometries of such a detector and an array of such detectors produce room temperature operated gamma ray spectrometers with relatively high resolution. For example, a 1 cm.sup.3 detector is capable of measuring .sup.137 Cs 662 keV gamma rays with room temperature energy resolution approaching 2% at FWHM. Two major types of such detectors include a parallel strip semiconductor Frisch grid detector and the geometrically weighted trapezoid prism semiconductor Frisch grid detector. The geometrically weighted detector records room temperature (24.degree. C.) energy resolutions of 2.68% FWHM for .sup.137 Cs 662 keV gamma rays and 2.45% FWHM for .sup.60 Co 1.332 MeV gamma rays. The detectors perform well without any electronic pulse rejection, correction or compensation techniques. The devices operate at room temperature with simple commercially available NIM bin electronics and do not require special preamplifiers or cooling stages for good spectroscopic results.

  5. Fire Emulator/Detector Evaluator

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The fire emulator/detector evaluator (FE/DE) is a computer-controlled flow tunnel used to re-create the environments surrounding detectors in the early...

  6. Fire Emulator/Detector Evaluator

    Data.gov (United States)

    Federal Laboratory Consortium — Description:The fire emulator/detector evaluator (FE/DE) is a computer-controlled flow tunnel used to re-create the environments surrounding detectors in the early...

  7. Sensitive neutron detection method using delayed coincidence transitions in existing iodine-containing detectors

    CERN Document Server

    Yakushev, E; Drokhlyansky, A; Filosofov, D; Kalaninova, Z; Timkin, V; Ponomarev, D

    2016-01-01

    This letter explains a new, highly sensitive method for the detection of neutrons, which uses the T$_{1/2}=845$ ns delay in the decay of $^{128}$I at the 137.8 keV energy level, resulting from the capture of thermal neutrons by iodine nuclei in NaI and CsI scintillation detectors. The use of delayed coincidence techniques with a several $\\mu {\\rm s}$ time frame for delayed events allows for the highly effective discrimination of neutron events from any existing background signals. A comparison of ambient neutron measurements between those identified through the suggested method from a cylindrical, \\o$\\, 63 \\, {\\rm mm}\\times 63\\, {\\rm mm}$ NaI(Tl) scintillator and those from a low-background proportional $^3$He counter experimentally demonstrates the efficacy of this neutron detection method. For an isotropic, $4\\pi$, thermal neutron flux of 1 ${\\rm n}\\, {\\rm cm}^{-2}\\, {\\rm s}^{-1}$, the absolute sensitivity of the NaI detector was found to be $6.5 \\pm 1\\, {\\rm counts}\\, {\\rm s}^{-1}$ with a background of $0....

  8. Position sensitive solid state detectors

    Energy Technology Data Exchange (ETDEWEB)

    Schnatterly, S.E.; Husk, D.

    1986-05-15

    Solid state detectors have been used for years as high quantum efficiency detectors for visible light. In this paper the use of PDA and CCD, solid state detectors, in the X-ray region will be discussed. In particular examples of data in the soft X-ray region are presented. Finally the use of phosphor coatings to enhance the sensitivity of solid state detectors is described.

  9. Radiation detectors laboratory; Laboratorio de detectores de radiacion

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez J, F.J. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The Radiation detectors laboratory was established with the assistance of the International Atomic Energy Agency which gave this the responsibility to provide its services at National and regional level for Latin America and it is located at the ININ. The more expensive and delicate radiation detectors are those made of semiconductor, so it has been put emphasis in the use and repairing of these detectors type. The supplied services by this laboratory are: selection consultant, detectors installation and handling and associated systems. Installation training, preventive and corrective maintenance of detectors and detection systems calibration. (Author)

  10. Characterisations of GEM detector prototype

    Energy Technology Data Exchange (ETDEWEB)

    Patra, Rajendra Nath [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064, West Bengal (India); Nanda, Amit [School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050 (India); Rudra, Sharmili [Department of Applied Physics, CU, 92, APC Road, Kolkata 700009, West Bengal (India); Bhattacharya, P.; Sahoo, Sumanya Sekhar [School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050 (India); Biswas, S., E-mail: saikat.ino@gmail.com [School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050 (India); Mohanty, B. [School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050 (India); Nayak, T.K. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064, West Bengal (India); Sahu, P.K.; Sahu, S. [Institute of Physics, Sachivalaya Marg, P.O.: Sainik School, Bhubaneswar 751005, Odisha (India)

    2016-07-11

    At NISER-IoP detector laboratory an initiative is taken to build and test Gas Electron Multiplier (GEM) detectors for ALICE experiment. The optimisation of the gas flow rate and the long-term stability test of the GEM detector are performed. The method and test results are presented.

  11. ATLAS Detector : Performance and Upgrades

    CERN Document Server

    Oliveira Damazio, Denis; The ATLAS collaboration

    2016-01-01

    Describe the ATLAS detector and summarize most relevant and recent information about the detector performance in 2016 with LHC colliding bunches at sqrt(s)=13 TeV with luminosity above the nominal value. Describe the different upgrade phases previewed for the detector and main activities already ongoing.

  12. Workshops on radiation imaging detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sochinskii, N.V.; Sun, G.C.; Kostamo, P.; Silenas, A.; Saynatjoki, A.; Grant, J.; Owens, A.; Kozorezov, A.G.; Noschis, E.; Van Eijk, C.; Nagarkar, V.; Sekiya, H.; Pribat, D.; Campbell, M.; Lundgren, J.; Arques, M.; Gabrielli, A.; Padmore, H.; Maiorino, M.; Volpert, M.; Lebrun, F.; Van der Putten, S.; Pickford, A.; Barnsley, R.; Anton, M.E.G.; Mitschke, M.; Gros d' Aillon, E.; Frojdh, C.; Norlin, B.; Marchal, J.; Quattrocchi, M.; Stohr, U.; Bethke, K.; Bronnimann, C.H.; Pouvesle, J.M.; Hoheisel, M.; Clemens, J.C.; Gallin-Martel, M.L.; Bergamaschi, A.; Redondo-Fernandez, I.; Gal, O.; Kwiatowski, K.; Montesi, M.C.; Smith, K

    2005-07-01

    This document gathers the transparencies that were presented at the international workshop on radiation imaging detectors. 9 sessions were organized: 1) materials for detectors and detector structure, 2) front end electronics, 3) interconnected technologies, 4) space, fusion applications, 5) the physics of detection, 6) industrial applications, 7) synchrotron radiation, 8) X-ray sources, and 9) medical and other applications.

  13. Characterizations of GEM detector prototype

    CERN Document Server

    Patra, Rajendra Nath; Rudra, Sharmili; Bhattacharya, P.; Sahoo, Sumanya Sekhar; Biswas, S.; Mohanty, B.; Nayak, T.K.; Sahu, P.K.; Sahu, S.

    2016-01-01

    At NISER-IoP detector laboratory an initiative is taken to build and test Gas Electron Multiplier (GEM) detectors for ALICE experiment. The optimisation of the gas flow rate and the long-term stability test of the GEM detector are performed. The method and test results are presented.

  14. Detector and System Developments for LHC Detector Upgrades

    CERN Document Server

    Mandelli, Beatrice; Guida, Roberto; Rohne, Ole; Stapnes, Steinar

    2015-05-12

    The future Large Hadron Collider (LHC) Physics program and the consequent improvement of the LHC accelerator performance set important challenges to all detector systems. This PhD thesis delineates the studies and strategies adopted to improve two different types of detectors: the replacement of precision trackers with ever increasingly performing silicon detectors, and the improvement of large gaseous detector systems by optimizing their gas mixtures and operation modes. Within the LHC tracker upgrade programs, the ATLAS Insertable B-layer (IBL) is the first major upgrade of a silicon-pixel detector. Indeed the overall ATLAS Pixel Detector performance is expected to degrade with the increase of luminosity and the IBL will recover the performance by adding a fourth innermost layer. The IBL Detector makes use of new pixel and front-end electronics technologies as well as a novel thermal management approach and light support and service structures. These innovations required complex developments and Quality Ass...

  15. Aerogel for FARICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Barnyakov, A.Yu. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Barnyakov, M.Yu. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, Karl Marks 20, Novosibirsk 630073 (Russian Federation); Bobrovnikov, V.S.; Buzykaev, A.R.; Gulevich, V.V. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Danilyuk, A.F. [Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Kononov, S.A.; Kravchenko, E.A. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Pirogova 2, Novosibirsk 630090 (Russian Federation); Kuyanov, I.A. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Lopatin, S.A. [Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Onuchin, A.P.; Ovtin, I.V.; Podgornov, N.A. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, Karl Marks 20, Novosibirsk 630073 (Russian Federation); Porosev, V.V. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Predein, A.Yu.; Protsenko, R.S. [Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090 (Russian Federation)

    2014-12-01

    We present our current experience in preparation of focusing aerogels for the Focusing Aerogel RICH detector. Multilayer focusing aerogel tiles have been produced in Novosibirsk by a collaboration of the Budker Institute of Nuclear Physics and Boreskov Institute of Catalysis since 2004. We have obtained 2–3–4-layer blocks with the thickness of 30–45 mm. In 2012, the first samples of focusing blocks with continuous density (refractive index) gradient along thickness were produced. This technology can significantly reduce the contribution from the geometric factor of the radiator thickness to the resolution of the measured Cherenkov angle in the FARICH detector. The special installation was used for automatic control of reagents ratio during the synthesis process. The first samples were tested using the digital radiography method and on the electron beam with the FARICH prototype.

  16. The LUCID detector

    CERN Document Server

    Lasagni Manghi, Federico; The ATLAS collaboration

    2015-01-01

    Starting from 2015 LHC is performing a new run, at higher center of mass energy (13 TeV) and with 25 ns bunch-spacing. The ATLAS luminosity monitor LUCID has been completely renewed, both on detector design and in the electronics, in order to cope with the new running conditions. The new detector electronics is presented, featuring a new read-out board (LUCROD), for signal acquisition and digitization, PMT-charge integration and single-side luminosity measurements, and the revisited LUMAT board for side-A-side-C combination. The contribution covers the new boards design, the firmware and software developments, the implementation of luminosity algorithms, the optical communication between boards and the integration into the ATLAS TDAQ system.

  17. UA1 central detector

    CERN Multimedia

    The UA1 central detector was crucial to understanding the complex topology of proton-antiproton events. It played a most important role in identifying a handful of Ws and Zs among billions of collisions. The detector was a 6-chamber cylindrical assembly 5.8 m long and 2.3 m in diameter, the largest imaging drift chamber of its day. It recorded the tracks of charged particles curving in a 0.7 Tesla magnetic field, measuring their momentum, the sign of their electric charge and their rate of energy loss (dE/dx). Atoms in the argon-ethane gas mixture filling the chambers were ionised by the passage of charged particles. The electrons which were released drifted along an electric field shaped by field wires and were collected on sense wires. The geometrical arrangement of the 17000 field wires and 6125 sense wires allowed a spectacular 3-D interactive display of reconstructed physics events to be produced.

  18. Metrology with Unknown Detectors.

    Science.gov (United States)

    Altorio, Matteo; Genoni, Marco G; Somma, Fabrizia; Barbieri, Marco

    2016-03-11

    The best possible precision is one of the key figures in metrology, but this is established by the exact response of the detection apparatus, which is often unknown. There exist techniques for detector characterization that have been introduced in the context of quantum technologies but apply as well for ordinary classical coherence; these techniques, though, rely on intense data processing. Here, we show that one can make use of the simpler approach of data fitting patterns in order to obtain an estimate of the Cramér-Rao bound allowed by an unknown detector, and we present applications in polarimetry. Further, we show how this formalism provides a useful calculation tool in an estimation problem involving a continuous-variable quantum state, i.e., a quantum harmonic oscillator.

  19. Metrology with Unknown Detectors

    CERN Document Server

    Altorio, Matteo; Somma, Fabrizia; Barbieri, Marco

    2015-01-01

    The best possible precision is one of the key figures in metrology, but this is established by the exact response of the detection apparatus, which is often unknown. There exist techniques for detector characterisation, that have been introduced in the context of quantum technologies, but apply as well for ordinary classical coherence; these techniques, though, rely on intense data processing. Here we show that one can make use of the simpler approach of data fitting patterns in order to obtain an estimate of the Cram\\'er-Rao bound allowed by an unknown detector, and present applications in polarimetry. Further, we show how this formalism provide a useful calculation tool in an estimation problem involving a continuous-variable quantum state, i.e. a quantum harmonic oscillator.

  20. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    G.Gomez

    Since September, the muon alignment system shifted from a mode of hardware installation and commissioning to operation and data taking. All three optical subsystems (Barrel, Endcap and Link alignment) have recorded data before, during and after CRAFT, at different magnetic fields and during ramps of the magnet. This first data taking experience has several interesting goals: •    study detector deformations and movements under the influence of the huge magnetic forces; •    study the stability of detector structures and of the alignment system over long periods, •    study geometry reproducibility at equal fields (specially at 0T and 3.8T); •    reconstruct B=0T geometry and compare to nominal/survey geometries; •    reconstruct B=3.8T geometry and provide DT and CSC alignment records for CMSSW. However, the main goal is to recons...

  1. Compound Semiconductor Radiation Detectors

    CERN Document Server

    Owens, Alan

    2012-01-01

    Although elemental semiconductors such as silicon and germanium are standard for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by their physical limitations, namely the need for ancillary cooling, their modest stopping powers, and radiation intolerance. Compound semiconductors, on the other hand, encompass such a wide range of physical and electronic properties that they have become viable competitors in a number of applications. Compound Semiconductor Radiation Detectors is a consolidated source of information on all aspects of the use of compound semiconductors for radiation detection and measurement. Serious Competitors to Germanium and Silicon Radiation Detectors Wide-gap compound semiconductors offer the ability to operate in a range of hostile thermal and radiation environments while still maintaining sub-keV spectral resolution at X-ray wavelengths. Narrow-gap materials offer the potential of exceeding the spectral resolutio...

  2. Future liquid Argon detectors

    CERN Document Server

    Rubbia, A

    2013-01-01

    The Liquid Argon Time Projection Chamber offers an innovative technology for a new class of massive detectors for rare-event detection. It is a precise tracking device that allows three-dimensional spatial reconstruction with mm-scale precision of the morphology of ionizing tracks with the imaging quality of a "bubble chamber", provides $dE/dx$ information with high sampling rate, and acts as high-resolution calorimeter for contained events. First proposed in 1977 and after a long maturing process, its holds today the potentialities of opening new physics opportunities by providing excellent tracking and calorimetry performance at the relevant multi-kton mass scales, outperforming other techniques. In this paper, we review future liquid argon detectors presently being discussed by the neutrino physics community.

  3. Biological detector and method

    Energy Technology Data Exchange (ETDEWEB)

    Sillerud, Laurel; Alam, Todd M.; McDowell, Andrew F.

    2015-11-24

    A biological detector includes a conduit for receiving a fluid containing one or more magnetic nanoparticle-labeled, biological objects to be detected and one or more permanent magnets or electromagnet for establishing a low magnetic field in which the conduit is disposed. A microcoil is disposed proximate the conduit for energization at a frequency that permits detection by NMR spectroscopy of whether the one or more magnetically-labeled biological objects is/are present in the fluid.

  4. Biological detector and method

    Science.gov (United States)

    Sillerud, Laurel; Alam, Todd M; McDowell, Andrew F

    2014-04-15

    A biological detector includes a conduit for receiving a fluid containing one or more magnetic nanoparticle-labeled, biological objects to be detected and one or more permanent magnets or electromagnet for establishing a low magnetic field in which the conduit is disposed. A microcoil is disposed proximate the conduit for energization at a frequency that permits detection by NMR spectroscopy of whether the one or more magnetically-labeled biological objects is/are present in the fluid.

  5. LHCb velo detector

    CERN Multimedia

    Patrice Loïez

    2001-01-01

    Photo 01 : L. to r.: D. Malinon, Summer Student, J. Libby, Fellow, J. Harvey, Head of CERN LHCb group, D. Schlatter, Head of the EP Division in front of the LHCb velo detector test beam (on the right). Photo 02 : L. to r.: J. Harvey, D. Schlatter, W. Riegler (staff), H.J. Hilke, LHCb Technical Coordinator in front of the muon chamber test beam

  6. Development of Portable Detectors

    Energy Technology Data Exchange (ETDEWEB)

    None

    2006-12-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) between UT-Battelle, LLC (the “Contractor”) and Sense Holdings, Inc. (the “Participant”) was for the development of hand-held detectors with high sensitivity and selectivity for the detection of explosives, toxic industrial chemicals and materials, and other materials of interest for security applications. The two parties built a series of demonstration and prototype handheld sensors based upon micoelectromechanical systems (MEMS) with electronic readout.

  7. Biological detector and method

    Science.gov (United States)

    Sillerud, Laurel; Alam, Todd M; McDowell, Andrew F

    2013-02-26

    A biological detector includes a conduit for receiving a fluid containing one or more magnetic nanoparticle-labeled, biological objects to be detected and one or more permanent magnets or electromagnet for establishing a low magnetic field in which the conduit is disposed. A microcoil is disposed proximate the conduit for energization at a frequency that permits detection by NMR spectroscopy of whether the one or more magnetically-labeled biological objects is/are present in the fluid.

  8. The ALEPH detector

    CERN Document Server

    1988-01-01

    For detecting the direction and momenta of charged particles with extreme accuracy, the ALEPH detector had at its core a time projection chamber, for years the world's largest. In the foreground from the left, Jacques Lefrancois, Jack Steinberger, Lorenzo Foa and Pierre Lazeyras. ALEPH was an experiment on the LEP accelerator, which studied high-energy collisions between electrons and positrons from 1989 to 2000.

  9. Hybrid superconducting neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Merlo, V.; Lucci, M.; Ottaviani, I. [Dipartimento di Fisica, Università Tor Vergata, Via della Ricerca Scientifica, I-00133 Roma (Italy); Salvato, M.; Cirillo, M. [Dipartimento di Fisica, Università Tor Vergata, Via della Ricerca Scientifica, I-00133 Roma (Italy); CNR SPIN Salerno, Università di Salerno, Via Giovanni Paolo II, n.132, 84084 Fisciano (Italy); Scherillo, A. [Science and Technology Facility Council, ISIS Facility Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Celentano, G. [ENEA Frascati Research Centre, Via. E. Fermi 45, 00044 Frascati (Italy); Pietropaolo, A., E-mail: antonino.pietropaolo@enea.it [ENEA Frascati Research Centre, Via. E. Fermi 45, 00044 Frascati (Italy); Mediterranean Institute of Fundamental Physics, Via Appia Nuova 31, 00040 Marino, Roma (Italy)

    2015-03-16

    A neutron detection concept is presented that is based on superconductive niobium (Nb) strips coated by a boron (B) layer. The working principle of the detector relies on the nuclear reaction, {sup 10}B + n → α + {sup 7}Li, with α and Li ions generating a hot spot on the current-biased Nb strip which in turn induces a superconducting-normal state transition. The latter is recognized as a voltage signal which is the evidence of the incident neutron. The above described detection principle has been experimentally assessed and verified by irradiating the samples with a pulsed neutron beam at the ISIS spallation neutron source (UK). It is found that the boron coated superconducting strips, kept at a temperature T = 8 K and current-biased below the critical current I{sub c}, are driven into the normal state upon thermal neutron irradiation. As a result of the transition, voltage pulses in excess of 40 mV are measured while the bias current can be properly modulated to bring the strip back to the superconducting state, thus resetting the detector. Measurements on the counting rate of the device are presented and the basic physical features of the detector are discussed.

  10. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2011-01-01

    During data-taking in 2010 the RPC system behaviour was very satisfactory for both the detector and trigger performances. Most of the data analyses are now completed and many results and plots have been approved in order to be published in the muon detector paper. A very detailed analysis of the detector efficiency has been performed using 60 million muon events taken with the dedicated RPC monitor stream. The results have shown that the 96.3% of the system was working properly with an average efficiency of 95.4% at 9.35 kV in the Barrel region and 94.9% at 9.55 kV in the Endcap. Cluster size goes from 1.6 to 2.2 showing a clear and well-known correlation with the strip pitch. Average noise in the Barrel is less than 0.4 Hz/cm2 and about 98% of full system has averaged noise less then 1 Hz/cm2. A linear dependence of the noise versus the luminosity has been preliminary observed and is now under study. Detailed chamber efficiency maps have shown a few percent of chambers with a non-uniform efficiency distribu...

  11. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2011-01-01

    RPC detector calibration, HV scan Thanks to the high LHC luminosity and to the corresponding high number of muons created in the first part of the 2011 the RPC community had, for the first time, the possibility to calibrate every single detector element (roll).The RPC steering committee provided the guidelines for both data-taking and data analysis and a dedicated task force worked from March to April on this specific issue. The main goal of the RPC calibration was to study the detector efficiency as a function of high-voltage working points, fit the obtained “plateau curve” with a sigmoid function and determine the “best” high-voltage working point of every single roll. On 18th and 19th March, we had eight runs at different voltages. On 27th March, the full analysis was completed, showing that 60% of the rolls had already a very good fit with an average efficiency greater than 93% in the plateau region. To improve the fit we decided to take three more runs (15th April...

  12. MUON DETECTORS: DT

    CERN Multimedia

    M. Dallavalle.

    The DT system is ready for the LHC start up. The status of detector hardware, control and safety, of the software for calibration and monitoring and of people has been reviewed at several meetings, starting with the CMS Action Matrix Review and with the Muon Barrel Workshop (October 5 to 7). The disconnected HV channels are at a level of about 0.1%. The loss in detector acceptance because of failures in the Read-Out and Trigger electronics is about 0.5%. The electronics failure rate has been lower this year: next year will tell us whether the rate has stabilised and hopefully will confirm that the number of spares is adequate for ten years operation. Although the detector safety control is very accurate and robust, incidents have happened. In particular the DT system suffered from a significant water leak, originated in the top part of YE+1, that generated HV trips in eighteen chambers going transversely down from the top sector in YB+2 to the bottom sector in YB-2. All chambers recovered and all t...

  13. UA1 prototype detector

    CERN Multimedia

    1980-01-01

    Prototype of UA1 central detector inside a plexi tube. The UA1 central detector was crucial to understanding the complex topology of proton-antiproton events. It played a most important role in identifying a handful of Ws and Zs among billions of collisions. The detector was a 6-chamber cylindrical assembly 5.8 m long and 2.3 m in diameter, the largest imaging drift chamber of its day. It recorded the tracks of charged particles curving in a 0.7 Tesla magnetic field, measuring their momentum, the sign of their electric charge and their rate of energy loss (dE/dx). Atoms in the argon-ethane gas mixture filling the chambers were ionised by the passage of charged particles. The electrons which were released drifted along an electric field shaped by field wires and were collected on sense wires. The geometrical arrangement of the 17000 field wires and 6125 sense wires allowed a spectacular 3-D interactive display of reconstructed physics events to be produced.

  14. Commissioning the SNO+ detector

    Science.gov (United States)

    Descamps, Freija; SNO+ Collaboration

    2016-09-01

    The SNO+ experiment is the successor to the Sudbury Neutrino Observatory (SNO), in which SNO's heavy water is replaced by approximately 780T of liquid scintillator (LAB). The combination of the 2km underground location, the use of ultra-clean materials and the high light-yield of the liquid scintillator means that a low background level and a low energy threshold can be achieved. This creates a new multipurpose neutrino detector with the potential to address a diverse set of physics goals, including the detection of reactor, solar, geo- and supernova neutrinos. A main physics goal of SNO+ is the search for neutrinoless double beta decay. By loading the liquid scintillator with 0.5% of natural Tellurium, resulting in about 1300kg of 130Te (isotopic abundance is slightly over 34%), a competitive sensitivity to the effective neutrino mass can be reached. This talk will present the status of the SNO+ detector, specifically the results and status of the detector commissioning with water.

  15. The STAR PXL detector

    Science.gov (United States)

    Contin, G.

    2016-12-01

    The PiXeL detector (PXL) of the STAR experiment at RHIC is the first application of the state-of-the-art thin Monolithic Active Pixel Sensors (MAPS) technology in a collider environment. Designed to extend the STAR measurement capabilities in the heavy flavor domain, it took data in Au+Au collisions, p+p and p+Au collisions at 0√sNN=20 GeV at RHIC, during the period 2014-2016. The PXL detector is based on 50 μm-thin MAPS sensors with a pitch of 20.7 μm. Each sensor includes an array of nearly 1 million pixels, read out in rolling shutter mode in 185.6 μs. The 170 mW/cm2 power dissipation allows for air cooling and contributes to reduce the global material budget to 0.4% radiation length on the innermost layer. Experience and lessons learned from construction and operations will be presented in this paper. Detector performance and results from 2014 Au+Au data analysis, demonstrating the STAR capabilities of charm reconstruction, will be shown.

  16. The STAR Vertex Position Detector

    CERN Document Server

    Llope, W J; Nussbaum, T; Hoffmann, G W; Asselta, K; Brandenburg, J D; Butterworth, J; Camarda, T; Christie, W; Crawford, H J; Dong, X; Engelage, J; Eppley, G; Geurts, F; Hammond, J; Judd, E; McDonald, D L; Perkins, C; Ruan, L; Scheblein, J; Schambach, J J; Soja, R; Xin, K; Yang, C

    2014-01-01

    The 2x3 channel pseudo Vertex Position Detector (pVPD) in the STAR experiment at RHIC has been upgraded to a 2x19 channel detector in the same acceptance, called the Vertex Position Detector (VPD). This detector is fully integrated into the STAR trigger system and provides the primary input to the minimum-bias trigger in Au+Au collisions. The information from the detector is used both in the STAR Level-0 trigger and offline to measure the location of the primary collision vertex along the beam pipe and the event "start time" needed by other fast-timing detectors in STAR. The offline timing resolution of single detector channels in full-energy Au+Au collisions is ~100 ps, resulting in a start time resolution of a few tens of picoseconds and a resolution on the primary vertex location of ~1 cm.

  17. 4pi聚焦系统中振幅和相位调制的径向偏振涡旋光束聚焦特性的研究*%Study of the focusing features of spatial amplitude and phase modulated radially polarized vortex beams in a 4pi focusing system∗

    Institute of Scientific and Technical Information of China (English)

    常强; 杨艳芳†; 何英; 刘海港; 刘键

    2013-01-01

      基于Richards-Wolf矢量衍射积分公式,研究了径向偏振涡旋光束在振幅和相位调制下的4pi聚焦特性。振幅调制是通过振幅滤波实现,即改变入射光束起始积分值达到调节,相位调制是通过添加相位延迟角δ的液晶相位延迟器来改变入射光束的偏振态。模拟结果显示,随着振幅的减小,4pi聚焦系统焦点附近的光轴上呈现出多光球结构;而相位调制对焦点附近的光强分布产生拉伸作用,即调节入射光束的拓扑核m和相位延迟器的延迟角δ,可以得到特殊的光强分布。随着相位δ增大, m=0产生的多光球结构慢慢向光链结构转变,最终变成暗通道;而m=1产生的光链结构慢慢变成光球结构;m=2产生的暗通道变成光球和光链叠加的结构,这种特殊聚焦光束在光学微操纵领域具有潜在的应用价值。%The focusing properties of phase and amplitude modulated radially polarized vortex beams in a 4pi focusing system are theoreti-cally investigated near the focal plane by using Richards-Wolf vectorial diffraction method. The amplitude modulation of vortex beams can be adjusted by changing the start integration value. The phase modulation of vortex beams can be realized by adding liquid crystal variable retarder with the phase delay angleδ. The simulated results show that multiple spherical spots can be obtained near the focus of the 4pi focusing system with the decrease of amplitude. The phase delay angleδ of the input beams can generate extruding effect for the electrical field distribution near the focus of the 4pi focusing system. Some special intensity distributions can be obtained by changing topological charge m and phase delay angleδ. Optical chain can be generated in the case of m=1. Dark channel can be ob-tained in the case of m=2. These special focusing beams can also transform with phase modulation. With the increase of phaseδ, the multiple spherical spots at m=0 change slowly

  18. Construction, Expression, and Characterization of a Recombinant Annexin B1-Low Molecular Weight Urokinase Chimera in Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    Hong-Li YAN; Wei-Ting WANG; Yan HE; Zhuan-You ZHAO; Yuan-Jian GAO; Yi ZHANG; Shu-Han SUN

    2004-01-01

    To produce a thrombi-targeting plasminogen activator,low molecular weight single-chain urokinase gene(scuPA32k)was spliced with the full-length cDNA of annexin B 1 gene(anxB1)by overlap extension method.The fused gene anxBlscuPA was ligated into pET28a vector,transformed into E.coli BL21-RIL,and then induced to express under the control of T7 promoter.The AnxB 1ScuPA protein expressed amounted to 22% of the total bacterial proteins.The product was refolded,and then purified by using DEAE Sepharose fast flow ion-exchange column and Superdex S-200 gel-filtration column.HPLC analysis revealed that the final purity is about 95%.The specific activity ofAnxB 1ScuPA,measured as amidolytic activity,reached 100,000 IU/mg.It had a similar S2444 catalytic efficiency(kcat/Km)to ScuPA32k,and also showed high activated-platelet membrane-binding activity and anticoagulant activity,indicating that the chimera fully retained the components of enzymatic and membrane-binding activities of the parent molecules.In vivo test revealed that,the dogs administered with AnxB 1ScuPA had less reperfusion time,higher reperfusion ratio,and less bleeding effects than those with urokinase.These findings indicated that AnxB 1ScuPAmight have advantages over current available thrombolytic agents.

  19. Chimera-free, high copy number YAC libraries and efficient methods of analysis. Final technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    The first experiment involved a low chimera YAC library in recombination deficient host strains. To determine if the genetic background of the yeast host strain contributes to the formation of chimeric YACs the same YAC ligation mixture was introduced into three isogenic yeast hosts differing only in their recombination abilities. To prepare YACs, human genomic DNA was partially digested with EcoR1 and then ligated to YAC vector pCGS966 arms. DNA was size fractionated before and after ligation by preparative pulsed field gel electrophoresis (CHEF), selecting for fragments greater than 400 kb, and introduced into competent spheroplasts. CHEF gel Southern blots of resulting colony-purified YACs were probed with human DNA to determine if multiple YACs or YAC fragments were present in the same cell. The frequency of chimeric YACs was measured by fluorescence in situ hybridization (FISH) of YACs to human prometaphase spreads. YACs that hybridized to more than one location were assumed to be chimeric. In the second experiment new YAC vectors featuring tags for capture of YACs and YAC inserts were constructed. Yeast Artificial Chromosomes (YACs) have been of tremendous value in the physical mapping of the human genome. Because they can carry very large inserts, YACs are likely not only to contain entire genes but also their control elements. However, the only mode of purification of YAC DNA from current commonly used YAC libraries such as the CEPH library is by pulsed field gel electrophoresis. This is an inefficient, time consuming process and due to the single copy nature of these YACs, often result in poor yields. The vector pCGS1000 was designed to test new efficient ways of YAC DNA purification.

  20. [Leaf anatomy of the mosaic ficus benjamina cv. Starlight and interaction of source and sink chimera components].

    Science.gov (United States)

    Labunskaia, E A; Zhigalova, T V; Chub, V V

    2007-01-01

    Leaf anatomy was studied in the mosaic Ficus benjamina cv. Starlight and non-chimeric Ficus benjamina cv. Daniel. The number of chloroplasts in a white, chlorophyll-deficient tissue declines as compared to the green tissue. However, their functional activity is retained. The leaf of the mosaic F. benjamina contains two or, sometimes, three subepidermal layers. Mesophyll forms one layer in the green and white parts of leaf palisade and one white and one green layer in the transitional zone (edge). In the transitional zone, green spongy mesophyll is located between two white spongy layers and the proportion of photosynthesizing cells varies. In cv. Daniel, there are two subepidermal layers and one layer of columnar mesophyll cells. According to the morphometry data, the proportion of white zone in the leaf correlates with the leaf position in the whole shoot: the higher the branch order, the larger the proportion of white zone. The total leaf area depends also on its position in the shoot. No such correlation was found in non-chimeric F. benjamina cv. Daniel. In the mosaic chimera, the source-sink status appears to depend on the leaf position in the shoot. Experiments with individual shoots of the same order and elimination of all lateral shoots have shown that the proportion of white zone in new leaves on the shoot increases with the total area of green zone. Thus, the area of assimilating shoot surface affects the formation of leaves in the meristem. A hypothesis was put forward that the source-sink state affects the ratio of green and white parts in the leaf primordium. Products of photosynthesis (carbohydrates) are a possible metabolic signal affecting the meristem. It cannot be excluded as well that the hormonal state undergoes changes in the chimeric plant.

  1. CHIMERA: Top-down model for hierarchical, overlapping and directed cluster structures in directed and weighted complex networks

    Science.gov (United States)

    Franke, R.

    2016-11-01

    In many networks discovered in biology, medicine, neuroscience and other disciplines special properties like a certain degree distribution and hierarchical cluster structure (also called communities) can be observed as general organizing principles. Detecting the cluster structure of an unknown network promises to identify functional subdivisions, hierarchy and interactions on a mesoscale. It is not trivial choosing an appropriate detection algorithm because there are multiple network, cluster and algorithmic properties to be considered. Edges can be weighted and/or directed, clusters overlap or build a hierarchy in several ways. Algorithms differ not only in runtime, memory requirements but also in allowed network and cluster properties. They are based on a specific definition of what a cluster is, too. On the one hand, a comprehensive network creation model is needed to build a large variety of benchmark networks with different reasonable structures to compare algorithms. On the other hand, if a cluster structure is already known, it is desirable to separate effects of this structure from other network properties. This can be done with null model networks that mimic an observed cluster structure to improve statistics on other network features. A third important application is the general study of properties in networks with different cluster structures, possibly evolving over time. Currently there are good benchmark and creation models available. But what is left is a precise sandbox model to build hierarchical, overlapping and directed clusters for undirected or directed, binary or weighted complex random networks on basis of a sophisticated blueprint. This gap shall be closed by the model CHIMERA (Cluster Hierarchy Interconnection Model for Evaluation, Research and Analysis) which will be introduced and described here for the first time.

  2. Soluble Jagged 1/Fc chimera protein induces the differentiation and maturation of bone marrow-derived dendritic cells

    Institute of Scientific and Technical Information of China (English)

    XING FeiYue; LIU Jing; YU Zhe; JI YuHua

    2008-01-01

    A soluble Jagged 1/Fc chimera protein (Jagged 1/Fc) was directly used to induce differentiation and maturation of bone marrow-derived dendritic cells (DCs) in mice in vitro. A model of inducing and am-plifying DCs in vitro was established. The effect of Jagged 1/Fc on morphology of DCs induced by both rmGM-CSF and rmlL-4 was observed under a confocal microscope. A fluorescein-labeled monoclonal antibody staining combined with flow cytometry was applied to detect the effect of Jagged 1/Fc on the expression of CD11c, MHC-Ⅱ, CD86, CD80 and CD40 molecules on the surface of DCs. The results showed that Jagged 1/Fc did not affect the morphological properties of DC differentiation induced by both rmGM-CSF and rmlL-4. But it could promote the differentiation and maturation of DCs induced by both. The effect of it was strikingly different in the expression profile of co-stimulating molecules and the morphologic properties of DCs from lipopolysaccharide (LPS). The levels of MHC-Ⅱ and CD40 molecule expression on the surface of DCs stimulated by Jagged 1/Fc were significantly lower than those stimulated by LPS, and the level of CD80 expression on the surface of DCs induced by Jagged 1/Fc was near to that induced by LPS. Jagged 1/Fc had no influence on the expression of CD86 mole-cule on the surface of DCs. Jagged 1/Fc when used alone could not maintain the growth, differentiation and maturation of DCs. All the findings indicate that Jagged 1/Fc influences the differentiation and maturation of DCs, which is not markedly similar to LPS, providing important evidence for its devel-opment and application as a novel immunosuppressant.

  3. Bioassays for TSH receptor autoantibodies, from FRTL-5 cells to TSH receptor–LH/CG receptor chimeras: the contribution of Leonard D. Kohn

    Directory of Open Access Journals (Sweden)

    Cesidio Giuliani

    2016-07-01

    Full Text Available Since the discovery 60 years ago of the long-acting thyroid stimulator by Adams and Purves, great progress has been made in the detection of thyroid-stimulating hormone (TSH receptor autoantibodies (TRAbs in Graves’ disease. Today, commercial assays are available that can detect TRAbs with high accuracy and provide diagnostic and prognostic evaluation of patients with Graves’ disease. The present review focuses on the development of TRAbs bioassays, and particularly on the role that Leonard D. Kohn had in this. Indeed, 30 years ago, the Kohn group developed a bioassay based on the use of FRTL-5 cells that was characterized by high reproducibility, feasibility, and diagnostic accuracy. Using this FRTL-5 bioassay, Kohn and his colleagues were the first to develop monoclonal antibodies against the TSH receptor. Furthermore, they demonstrated the multifaceted functional nature of TRAbs in patients with Graves’ disease, with the identification of stimulating and blocking TRAbs, and even antibodies that activated pathways other than cAMP. After the cloning of the TSH receptor, the Kohn laboratory constructed human TSH receptor–rat luteinizing hormone/ chorionic gonadotropin receptor chimeras. This paved the way to a new bioassay based on the use of nonthyroid cells transfected with the Mc4 chimera. The new Mc4 bioassay is characterized by high diagnostic and prognostic accuracy, greater than for other assays. The availability of a commercial kit based on the Mc4 chimera is spreading the use of this assay worldwide, indicating its benefits for these patients with Graves’ disease. This review also describes the main contributions made by others researchers in TSH receptor molecular biology and TRAbs assay, especially with the development of highly potent monoclonal antibodies. A comparison of the diagnostic accuracies of the main TRAbs assays, as both immunoassays and bioassays, is also provided.

  4. Bioassays for TSH Receptor Autoantibodies, from FRTL-5 Cells to TSH Receptor–LH/CG Receptor Chimeras: The Contribution of Leonard D. Kohn

    Science.gov (United States)

    Giuliani, Cesidio; Saji, Motoyasu; Bucci, Ines; Napolitano, Giorgio

    2016-01-01

    Since the discovery 60 years ago of the “long-acting thyroid stimulator” by Adams and Purves, great progress has been made in the detection of thyroid-stimulating hormone (TSH) receptor (TSHR) autoantibodies (TRAbs) in Graves’ disease. Today, commercial assays are available that can detect TRAbs with high accuracy and provide diagnostic and prognostic evaluation of patients with Graves’ disease. The present review focuses on the development of TRAbs bioassays, and particularly on the role that Leonard D. Kohn had in this. Indeed, 30 years ago, the Kohn group developed a bioassay based on the use of FRTL-5 cells that was characterized by high reproducibility, feasibility, and diagnostic accuracy. Using this FRTL-5 bioassay, Kohn and his colleagues were the first to develop monoclonal antibodies (moAbs) against the TSHR. Furthermore, they demonstrated the multifaceted functional nature of TRAbs in patients with Graves’ disease, with the identification of stimulating and blocking TRAbs, and even antibodies that activated pathways other than cAMP. After the cloning of the TSHR, the Kohn laboratory constructed human TSHR–rat luteinizing hormone/chorionic gonadotropin receptor chimeras. This paved the way to a new bioassay based on the use of non-thyroid cells transfected with the Mc4 chimera. The new Mc4 bioassay is characterized by high diagnostic and prognostic accuracy, greater than for other assays. The availability of a commercial kit based on the Mc4 chimera is spreading the use of this assay worldwide, indicating its benefits for these patients with Graves’ disease. This review also describes the main contributions made by other researchers in TSHR molecular biology and TRAbs assay, especially with the development of highly potent moAbs. A comparison of the diagnostic accuracies of the main TRAbs assays, as both immunoassays and bioassays, is also provided. PMID:27504107

  5. Bioassays for TSH Receptor Autoantibodies, from FRTL-5 Cells to TSH Receptor-LH/CG Receptor Chimeras: The Contribution of Leonard D. Kohn.

    Science.gov (United States)

    Giuliani, Cesidio; Saji, Motoyasu; Bucci, Ines; Napolitano, Giorgio

    2016-01-01

    Since the discovery 60 years ago of the "long-acting thyroid stimulator" by Adams and Purves, great progress has been made in the detection of thyroid-stimulating hormone (TSH) receptor (TSHR) autoantibodies (TRAbs) in Graves' disease. Today, commercial assays are available that can detect TRAbs with high accuracy and provide diagnostic and prognostic evaluation of patients with Graves' disease. The present review focuses on the development of TRAbs bioassays, and particularly on the role that Leonard D. Kohn had in this. Indeed, 30 years ago, the Kohn group developed a bioassay based on the use of FRTL-5 cells that was characterized by high reproducibility, feasibility, and diagnostic accuracy. Using this FRTL-5 bioassay, Kohn and his colleagues were the first to develop monoclonal antibodies (moAbs) against the TSHR. Furthermore, they demonstrated the multifaceted functional nature of TRAbs in patients with Graves' disease, with the identification of stimulating and blocking TRAbs, and even antibodies that activated pathways other than cAMP. After the cloning of the TSHR, the Kohn laboratory constructed human TSHR-rat luteinizing hormone/chorionic gonadotropin receptor chimeras. This paved the way to a new bioassay based on the use of non-thyroid cells transfected with the Mc4 chimera. The new Mc4 bioassay is characterized by high diagnostic and prognostic accuracy, greater than for other assays. The availability of a commercial kit based on the Mc4 chimera is spreading the use of this assay worldwide, indicating its benefits for these patients with Graves' disease. This review also describes the main contributions made by other researchers in TSHR molecular biology and TRAbs assay, especially with the development of highly potent moAbs. A comparison of the diagnostic accuracies of the main TRAbs assays, as both immunoassays and bioassays, is also provided.

  6. Transient replication of a hepatitis C virus genotype 1b replicon chimera encoding NS5A-5B from genotype 3a.

    Science.gov (United States)

    Kylefjord, Helen; Danielsson, Axel; Sedig, Susanne; Belda, Oscar; Wiktelius, Daniel; Vrang, Lotta; Targett-Adams, Paul

    2014-01-01

    Although hepatitis C virus (HCV) is a pathogen of global significance, experimental therapies in current clinical development include highly efficacious all-oral combinations of HCV direct-acting antivirals (DAAs). If approved for use, these new treatment regimens will impact dramatically upon our capacity to eradicate HCV in the majority of virus-infected patients. However, recent data from late-stage clinical evaluations demonstrated that individuals infected with HCV genotype (GT) 3 responded less well to all-oral DAA combinations than patients infected with other HCV GTs. In light of these observations, the present study sought to expand the number of molecular tools available to investigate small molecule-mediated inhibition of HCV GT3 NS5A and NS5B proteins in preclinical tissue-culture systems. Accordingly, a novel subgenomic HCV replicon chimera was created by utilizing a GT1b backbone modified to produce NS5A and NS5B proteins from a consensus sequence generated from HCV GT3a genomic sequences deposited online at the European Hepatitis C Virus database. This approach avoided the need to isolate and amplify HCV genomes from sera derived from HCV-infected patients. The replicon chimera, together with a version engineered to express NS5A encoding a Y93H mutation, demonstrated levels of replication in transient assays robust enough to assess accurate antiviral activities of inhibitors representing different HCV DAA classes. Thus, the replicon chimera represents a new simple molecular tool suitable for drug discovery programmes aimed at investigating, understanding, and improving GT3a activities of HCV DAAs targeting NS5A or NS5B.

  7. Screening of biotechnical parameters for production of bovine inter-subspecies embryonic chimeras by the aggregation of tetraploid Bos indicus and diploid crossbred Bos taurus embryos.

    Science.gov (United States)

    Razza, Eduardo M; Satrapa, Rafael A; Emanuelli, Isabele P; Barros, Ciro M; Nogueira, Marcelo F G

    2016-03-01

    The aggregation of a tetraploid zebu embryo (Bos indicus, a thermotolerant breed) with a diploid taurine embryo (Bos taurus, a thermosensitive breed) should create a complete taurine fetus, whose extra-embryonic components, e.g., the chorion, is derived mainly from the zebu embryo. These zebu-derived extra-embryonic components may interact positively with the taurine embryo/fetus during pregnancy in a tropical environment. We tested different parameters for the production of tetraploid Nelore (Bos indicus) embryos to be combined via aggregation with crossbred Bos taurus (diploid) embryos in order to produce viable chimeric blastocysts. Bovine (Bos indicus or crossbred Bos taurus) embryos were produced in vitro according to standard procedures. Two-cell Bos indicus embryos were submitted to electrofusion with varying numbers of pulses (1 or 2), voltages (0.4, 0.5, 0.75, 1.0, 1.4 and 5.0 kV/cm) and time (20, 25, 50 and 60 μs) to produce tetraploid embryos. Electrofused embryos were cultured with crossbred non-fused embryos to form chimeras that developed until the blastocyst stage. The best fusion parameter was 0.75 kV/cm for 60 μs. Four chimeric blastocysts (tetraploid Nelore with diploid crossbred Holstein) were formed after 31 attempts in 4 replicates (13%). We established an optimal procedure for the production of tetraploid Bos indicus (4n) embryos and embryonic chimeras by aggregation of crossbred Bos taurus (2n) with Bos indicus (4n) embryos. This technique would be valid in applied research, by producing exclusively taurine calves, but with placental elements from the Bos indicus breed, following transfer of these chimeras into recipient cows.

  8. NHE1 inhibition by amiloride- and benzoylguanidine-type compounds. Inhibitor binding loci deduced from chimeras of NHE1 homologues with endogenous differences in inhibitor sensitivity

    DEFF Research Database (Denmark)

    Pedersen, Stine F; King, Scott A; Nygaard, Eva B;

    2007-01-01

    The interaction of the ubiquitous Na(+)/H(+) exchanger, NHE1, with its commonly used inhibitors, amiloride- and benzoylguanidine (Hoechst type inhibitor (HOE))-type compounds, is incompletely understood. We previously cloned NHE1 from Amphiuma tridactylum (AtNHE1) and Pleuronectes americanus (Pa......NHE1). Although highly homologous to the amiloride- and HOE-sensitive human NHE1 (hNHE1), AtNHE1 is insensitive to HOE-type and PaNHE1 to both amiloride- and HOE-type compounds. Here we generated chimeras to "knock in" amiloride and HOE sensitivity to PaNHE1, and we thereby identified several NHE1...

  9. Adaptation of Soybean mosaic virus avirulent chimeras containing P3 sequences from virulent strains to Rsv1-genotype soybeans is mediated by mutations in HC-Pro.

    Science.gov (United States)

    Hajimorad, M R; Eggenberger, A L; Hill, J H

    2008-07-01

    In Rsv1-genotype soybean, Soybean mosaic virus (SMV)-N (an avirulent isolate of strain G2) elicits extreme resistance (ER) whereas strain SMV-G7 provokes a lethal systemic hypersensitive response (LSHR). SMV-G7d, an experimentally evolved variant of SMV-G7, induces systemic mosaic. Thus, for Rsv1-genotype soybean, SMV-N is avirulent whereas SMV-G7 and SMV-G7d are both virulent. Exploiting these differential interactions, we recently mapped the elicitor functions of SMV provoking Rsv1-mediated ER and LSHR to the N-terminal 271 amino acids of P3 from SMV-N and SMV-G7, respectively. The phenotype of both SMV-G7 and SMV-G7d were rendered avirulent on Rsv1-genotype soybean when the part of the genome encoding the N-terminus or the entire P3 cistron was replaced with that from SMV-N; however, reciprocal exchanges did not confer virulence to SMV-N-derived P3 chimeras. Here, we describe virulent SMV-N-derived P3 chimeras containing the full-length or the N-terminal P3 from SMV-G7 or SMV-G7d, with or without additional mutations in P3, that were selected on Rsv1-genotype soybean by sequential transfers on rsv1 and Rsv1-genotype soybean. Sequence analyses of the P3 and helper-component proteinase (HC-Pro) cistrons of progeny recovered from Rsv1-genotype soybean consistently revealed the presence of mutations in HC-Pro. Interestingly, the precise mutations in HC-Pro required for the adaptation varied among the chimeras. No mutation was detected in the HC-Pro of progeny passaged continuously in rsv1-genotype soybean, suggesting that selection is a consequence of pressure imposed by Rsv1. Mutations in HC-Pro alone failed to confer virulence to SMV-N; however, reconstruction of mutations in HC-Pro of the SMV-N-derived P3 chimeras resulted in virulence. Taken together, the data suggest that HC-Pro complementation of P3 is essential for SMV virulence on Rsv1-genotype soybean.

  10. The DELPHI Detector (DEtector with Lepton Photon and Hadron Identification)

    CERN Multimedia

    Crawley, B; Munich, K; Mckay, R; Matorras, F; Joram, C; Malychev, V; Behrmann, A; Van dam, P; Drees, J K; Stocchi, A; Adam, W; Booth, P; Bilenki, M; Rosenberg, E I; Morton, G; Rames, J; Hahn, S; Cosme, G; Ventura, L; Marco, J; Tortosa martinez, P; Monge silvestri, R; Moreno, S; Phillips, H; Alekseev, G; Boudinov, E; Martinez rivero, C; Gitarskiy, L; Davenport, M; De clercq, C; Firestone, A; Myagkov, A; Belous, K; Haider, S; Hamilton, K M; Lamsa, J; Rahmani, M H; Malek, A; Hughes, G J; Peralta, L; Carroll, L; Fuster verdu, J A; Cossutti, F; Gorn, L; Yi, J I; Bertrand, D; Myatt, G; Richard, F; Shapkin, M; Hahn, F; Ferrer soria, A; Reinhardt, R; Renton, P; Sekulin, R; Timmermans, J; Baillon, P

    2002-01-01

    % DELPHI The DELPHI Detector (Detector with Lepton Photon and Hadron Identification) \\\\ \\\\DELPHI is a general purpose detector for physics at LEP on and above the Z$^0$, offering three-dimensional information on curvature and energy deposition with fine spatial granularity as well as identification of leptons and hadrons over most of the solid angle. A superconducting coil provides a 1.2~T solenoidal field of high uniformity. Tracking relies on the silicon vertex detector, the inner detector, the Time Projection Chamber (TPC), the outer detector and forward drift chambers. Electromagnetic showers are measured in the barrel with high granularity by the High Density Projection Chamber (HPC) and in the endcaps by $ 1 ^0 $~x~$ 1 ^0 $ projective towers composed of lead glass as active material and phototriode read-out. Hadron identification is provided mainly by liquid and gas Ring Imaging Counters (RICH). The instrumented magnet yoke serves for hadron calorimetry and as filter for muons, which are identified in t...

  11. PHENIX inner detectors

    Energy Technology Data Exchange (ETDEWEB)

    Allen, M.; Bennett, M.J.; Bobrek, M.; Boissevain, J.B.; Boose, S.; Bosze, E.; Britton, C.; Chang, J.; Chi, C.Y.; Chiu, M.; Conway, R.; Cunningham, R.; Denisov, A.; Deshpande, A.; Emery, M.S.; Enokizono, A.; Ericson, N.; Fox, B.; Fung, S.-Y.; Giannotti, P.; Hachiya, T.; Hansen, A.G.; Homma, K.; Jacak, B.V.; Jaffe, D.; Kang, J.H.; Kapustinsky, J.; Kim, S.Y.; Kim, Y.G.; Kohama, T.; Kroon, P.J.; Lenz, W.; Longbotham, N.; Musrock, M.; Nakamura, T.; Ohnishi, H.; Ryu, S.S.; Sakaguchi, A.; Seto, R.; Shiina, T.; Simpson, M.; Simon-Gillo, J.; Sondheim, W.E.; Sugitate, T.; Sullivan, J.P. E-mail: sullivan@lanl.gov; Hecke, H.W. van; Walker, J.W.; White, S.N.; Willis, P.; Xu, N

    2003-03-01

    The timing, location and particle multiplicity of a PHENIX collision are determined by the Beam-Beam Counters (BBC), the Multiplicity/Vertex Detector (MVD) and the Zero-Degree Calorimeters (ZDC). The BBCs provide both the time of interaction and position of a collision from the flight time of prompt particles. The MVD provides a measure of event particle multiplicity, collision vertex position and fluctuations in charged particle distributions. The ZDCs provide information on the most grazing collisions. A Normalization Trigger Counter (NTC) is used to obtain absolute cross-section measurements for p-p collisions. The BBC, MVD and NTC are described below.

  12. Microstructured silicon radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat; Derzon, Mark S.; Draper, Bruce L.

    2017-03-14

    A radiation detector comprises a silicon body in which are defined vertical pores filled with a converter material and situated within silicon depletion regions. One or more charge-collection electrodes are arranged to collect current generated when secondary particles enter the silicon body through walls of the pores. The pores are disposed in low-density clusters, have a majority pore thickness of 5 .mu.m or less, and have a majority aspect ratio, defined as the ratio of pore depth to pore thickness, of at least 10.

  13. Flexible composite radiation detector

    Science.gov (United States)

    Cooke, D. Wayne; Bennett, Bryan L.; Muenchausen, Ross E.; Wrobleski, Debra A.; Orler, Edward B.

    2006-12-05

    A flexible composite scintillator was prepared by mixing fast, bright, dense rare-earth doped powdered oxyorthosilicate (such as LSO:Ce, LSO:Sm, and GSO:Ce) scintillator with a polymer binder. The binder is transparent to the scintillator emission. The composite is seamless and can be made large and in a wide variety of shapes. Importantly, the composite can be tailored to emit light in a spectral region that matches the optimum response of photomultipliers (about 400 nanometers) or photodiodes (about 600 nanometers), which maximizes the overall detector efficiency.

  14. Scintillating fiber detector

    CERN Document Server

    Vozak, Matous

    2016-01-01

    NA61 is one of the physics experiments at CERN dedicated to study hadron states coming from interactions of SPS beams with various targets. To determine the position of a secondary beam, three proportional chambers are placed along the beamline. However, these chambers tend to have slow response. In order to obtain more precise time information, use of another detector is being considered. Fast response and compact size is making scintillation fiber (SciFi) with silicon photomultiplier (Si-PM) read out a good candidate. This report is focused on analysing data from SciFi collected in a test beam at the beginning of July 2016.

  15. Preliminary results of fission induced by (1068 MeV) pi in Cu, Sn, Au and Bi using CR-39 detectors

    CERN Document Server

    Khan, H A; Shahzad, M I; Manzoor, S; Farooq, M A; Sher, G; Khan, E U; Peterson, R J

    1999-01-01

    Fission probabilities in pion induced reactions exhibit characteristic variations with respect to pion energies and target fissility values. At incident energies well above the pion-nucleon resonances, the statistical model seems to give good description of the observed data. We have used negative pions of energy 1068 MeV, in order to study fission induced in four target materials with fissility values [(Z-1)2/A] ranging from 12 to 32. All targets were arranged in a single stack in such a way that each target coated on a CR-39 detector was sandwiched by another uncoated CR-39 detector plate. The stack was irradiated at the AGS of Brookhaven National Laboratory (USA). This set-up ensures solid angle coverage of almost 4 pi degrees, so that for each fission event one of the fission fragments is expected to be trapped by the forward detector and one by the detector covering backward hemisphere. The effect of pion momentum transfer to the struck nucleus was observed in the form of asymmetry between events counted...

  16. Infrared detectors for space applications

    Science.gov (United States)

    Fick, Wolfgang; Gassmann, Kai Uwe; Haas, Luis-Dieter; Haiml, Markus; Hanna, Stefan; Hübner, Dominique; Höhnemann, Holger; Nothaft, Hans-Peter; Thöt, Richard

    2013-12-01

    The motivation and intended benefits for the use of infrared (IR) detectors for space applications are highlighted. The actual status of state-of-the-art IR detectors for space applications is presented based on some of AIM's currently ongoing focal plane detector module developments covering the spectral range from the short-wavelength IR (SWIR) to the long-wavelength IR (LWIR) and very long-wavelength IR (VLWIR), where both imaging and spectroscopy applications will be addressed. In particular, the integrated detector cooler assemblies for a mid-wavelength IR (MWIR) push-broom imaging satellite mission, for the German hyperspectral satellite mission EnMAP and the IR detectors for the Sentinel 3 SLSTR will be elaborated. Additionally, dedicated detector modules for LWIR/VLWIR sounding, providing the possibility to have two different PVs driven by one ROIC, will be addressed.

  17. Digital detectors for electron microscopy

    CERN Document Server

    Faruqi, A R

    2002-01-01

    Film has traditionally been used for recording images in transmission electron microscopes but there is an essential need for computer-interfaced electronic detectors. Cooled-CCD detectors, developed over the past few years, though not ideal, are increasingly used as the preferred detection system in a number of applications. We describe briefly the design of CCD-based detectors, along with their main properties, which have been used in electron crystallography. A newer detector design with a much bigger sensitive area, incorporating a 2x2 tiled array of CCDs with tapered fibre optics will overcome some of the limitations of existing CCD detectors. We also describe some preliminary results for 8 keV imaging, from (direct detection) silicon hybrid pixel detectors, which offer advantages over CCDs in terms of better spatial resolution, faster readout with minimal noise.

  18. Scalar top study: Detector optimization

    Indian Academy of Sciences (India)

    C Milsténe; A Sopczak

    2007-11-01

    A vertex detector concept of the linear collider flavour identification (LCFI) collaboration, which studies pixel detectors for heavy quark flavour identification, has been implemented in simulations for -quark tagging in scalar top studies. The production and decay of scalar top quarks (stops) is particularly interesting for the development of the vertex detector as only two -quarks and missing energy (from undetected neutralinos) are produced for light stops. Previous studies investigated the vertex detector design in scenarios with large mass differences between stop and neutralino, corresponding to large visible energy in the detector. In this study we investigate the tagging performance dependence on the vertex detector design in a scenario with small visible energy for the international linear collider (ILC).

  19. Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors - Particle Detectors and Detector Systems

    CERN Document Server

    Ullaland, O

    2011-01-01

    Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors in 'Particle Detectors and Detector Systems', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Section '3.3 Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors' of Chapter '3 Particle Detectors and Detector Systems' with the content: 3.3 Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors 3.3.1 Introduction 3.3.2 Time of Flight Measurements 3.3.2.1 Scintillator hodoscopes 3.3.2.2 Parallel plate ToF detectors 3.3.3 Cherenkov Radiation 3.3.3.1 ...

  20. The 4th concept detector

    Indian Academy of Sciences (India)

    John Hauptman

    2007-12-01

    The 4th concept detector consists of four detector subsystems, a small-pixel vertex detector, a high-resolution TPC, a new multiple-readout fiber calorimeter and a new dual-solenoid iron-free muon system. We discuss the design of a comprehensive facility that measures and identifies all partons of the standard model, including hadronic → and → decays, with high precision and high e±ciency. We emphasis here the calorimeter and muon systems.

  1. The CMS detector before closure

    CERN Multimedia

    Patrice Loiez

    2006-01-01

    The CMS detector before testing using muon cosmic rays that are produced as high-energy particles from space crash into the Earth's atmosphere generating a cascade of energetic particles. After closing CMS, the magnets, calorimeters, trackers and muon chambers were tested on a small section of the detector as part of the magnet test and cosmic challenge. This test checked the alignment and functionality of the detector systems, as well as the magnets.

  2. First detectors at the ISR

    CERN Multimedia

    1971-01-01

    Some of the first detectors at the ISR. A CERN/Rome team was looking at proton scattering at very small angles to the beam direction. A detector known as a "Roman pot" is in the foreground on the left. An Aachen/CERN/Genoa/Harvard/Turin team was looking at wider angles with the detectors seen branching off from the rings on the right.

  3. Decoherence of the Unruh detector

    CERN Document Server

    Demers, G

    1995-01-01

    As it is well known, the Minkowski vacuum appears thermally populated to a quantum mechanical detector on a uniformly accelerating course. We investigate how this thermal radiation may contribute to the classical nature of the detector's trajectory through the criteria of decoherence. An uncertainty-type relation is obtained for the detector involving the fluctuation in temperature, the time of flight and the coupling to the bath.

  4. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2011-01-01

    The RPC muon detector and trigger are working very well, contributing positively to the high quality of CMS data. Most of 2011 has been used to improve the stability of our system and the monitoring tools used online and offline by the shifters and experts. The high-voltage working point is corrected, chamber-by-chamber, for pressure variation since July 2011. Corrections are applied at PVSS level during the stand-by mode (no collision) and are not changed until the next fill. The single detector calibration, HV scan, of February and the P-correction described before were very important steps towards fine-tuning the stability of the RPC performances. A very detailed analysis of the RPC performances is now ongoing and from preliminary results we observe an important improvements of the cluster size stability in time. The maximum oscillation of the cluster size run by run is now about 1%. At the same time we are not observing the same stability in the detection efficiency that shows an oscillation of about ...

  5. MUON DETECTORS: CSC

    CERN Multimedia

    J. Hauser

    2011-01-01

    The earliest collision data in 2011 already show that the CSC detector performance is very similar to that seen in 2010. That is discussed in the DPG write-up elsewhere in this Bulletin. This report focuses on a few operational developments, the ME1/1 electronics replacement project, and the preparations at CERN for building the fourth station of CSC chambers ME4/2. During the 2010 LHC run, the CSC detector ran smoothly for the most part and yielded muon triggers and data of excellent quality. Moreover, no major operational problems were found that needed to be fixed during the Extended Technical Stop. Several improvements to software and configuration were however made. One such improvement is the automation of recovery from chamber high-voltage trips. The algorithm, defined by chamber experts, uses the so-called "Expert System" to analyse the trip signals sent from DCS and, based on the frequency and the timing of the signals, respond appropriately. This will make the central DCS shifters...

  6. PAU camera: detectors characterization

    Science.gov (United States)

    Casas, Ricard; Ballester, Otger; Cardiel-Sas, Laia; Castilla, Javier; Jiménez, Jorge; Maiorino, Marino; Pío, Cristóbal; Sevilla, Ignacio; de Vicente, Juan

    2012-07-01

    The PAU Camera (PAUCam) [1,2] is a wide field camera that will be mounted at the corrected prime focus of the William Herschel Telescope (Observatorio del Roque de los Muchachos, Canary Islands, Spain) in the next months. The focal plane of PAUCam is composed by a mosaic of 18 CCD detectors of 2,048 x 4,176 pixels each one with a pixel size of 15 microns, manufactured by Hamamatsu Photonics K. K. This mosaic covers a field of view (FoV) of 60 arcmin (minutes of arc), 40 of them are unvignetted. The behaviour of these 18 devices, plus four spares, and their electronic response should be characterized and optimized for the use in PAUCam. This job is being carried out in the laboratories of the ICE/IFAE and the CIEMAT. The electronic optimization of the CCD detectors is being carried out by means of an OG (Output Gate) scan and maximizing it CTE (Charge Transfer Efficiency) while the read-out noise is minimized. The device characterization itself is obtained with different tests. The photon transfer curve (PTC) that allows to obtain the electronic gain, the linearity vs. light stimulus, the full-well capacity and the cosmetic defects. The read-out noise, the dark current, the stability vs. temperature and the light remanence.

  7. MUON DETECTORS: RPC

    CERN Multimedia

    G. Iaselli.

    Substantial progress has been made on the RPC system resulting in a high standard of operation. Impressive improvements have been made in the online software and DCS PVSS protocols that ensure robustness of the configuration phase and reliability of the detector monitoring tasks. In parallel, an important upgrade of CCU ring connectivity was pursued to avoid noise pick-up and consequent  data transmission errors during operation with magnetic field. While the barrel part is already well synchronized thanks to the long cosmics runs, some refinements are still required on the forward part. The "beam splashes" have been useful to cross check  the existing delay constants, but further efforts will be made as soon as a substantial sample of beam-halo events is available. Progress has been made on early detector performance studies. The RPC DQM tool is being extensively used and minor bugs have been found. More plots have been added and more people have been tr...

  8. Advanced Radiation Detector Development

    Energy Technology Data Exchange (ETDEWEB)

    The University of Michigan

    1998-07-01

    Since our last progress report, the project at The University of Michigan has continued to concentrate on the development of gamma ray spectrometers fabricated from cadmium zinc telluride (CZT). This material is capable of providing energy resolution that is superior to that of scintillation detectors, while avoiding the necessity for cooling associated with germanium systems. In our past reports, we have described one approach (the coplanar grid electrode) that we have used to partially overcome some of the major limitations on charge collection that is found in samples of CZT. This approach largely eliminates the effect of hole motion in the formation of the output signal, and therefore leads to pulses that depend only on the motion of a single carrier (electrons). Since electrons move much more readily through CZT than do holes, much better energy resolution can be achieved under these conditions. In our past reports, we have described a 1 cm cube CZT spectrometer fitted with coplanar grids that achieved an energy resolution of 1.8% from the entire volume of the crystal. This still represents, to our knowledge, the best energy resolution ever demonstrated in a CZT detector of this size.

  9. MUON DETECTORS: DT

    CERN Multimedia

    Marco Dallavalle

    2012-01-01

      Although the year 2012 is the third year without access to the chambers and the Front-End electronics, the fraction of good channels is still very high at 99.1% thanks also to the constant care provided by the on-site operation team. The downtime caused to CMS as a consequence of DT failures is to-date <2%. The intervention on the LV power supplies, which required a large number of CAEN modules (137 A3050, 13 A3100, and 3 MAO) to be removed from the detector, reworked and tested during this Year-End Technical Stop, can now, after a few months of stable operation of the LV, be declared to have solved once-and-for-all the persistent problem with the overheating LV Anderson connectors. Another piece of very good news is that measurements of the noise from single-hit rate outside the drift-time box as a function of the LHC luminosity show that the noise rate and distribution are consistent with expectations of the simulations in the Muon TDR, which have guided the detector design and constru...

  10. MUON DETECTORS: DT

    CERN Multimedia

    Marco Dallavalle

    2013-01-01

    The DT group is undertaking substantial work both for detector maintenance and for detec-tor upgrade. Maintenance interventions on chambers and minicrates require close collaboration between DT, RPC and HO, and are difficult because they depend on the removal of thermal shields and cables on the front and rear of the chambers in order to gain access. The tasks are particularly critical on the central wheel due to the presence of fixed services. Several interventions on the chambers require extraction of the DT+RPC package: a delicate operation due to the very limited space for handling the big chambers, and the most dangerous part of the DT maintenance campaign. The interventions started in July 2013 and will go on until spring 2014. So far out of the 16 chambers with HV problems, 13 have been already repaired, with a global yield of 217 recovered channels. Most of the observed problems were due to displacement of impurities inside the gaseous volume. For the minicrates and FE, repairs occurred on 22 chambe...

  11. ATLAS Detector Upgrade Prospects

    Science.gov (United States)

    Dobre, M.; ATLAS Collaboration

    2017-01-01

    After the successful operation at the centre-of-mass energies of 7 and 8 TeV in 2010-2012, the LHC was ramped up and successfully took data at the centre-of-mass energies of 13 TeV in 2015 and 2016. Meanwhile, plans are actively advancing for a series of upgrades of the accelerator, culminating roughly ten years from now in the high-luminosity LHC (HL-LHC) project, which will deliver of the order of five times the LHC nominal instantaneous luminosity along with luminosity levelling. The ultimate goal is to extend the dataset from about few hundred fb ‑1 expected for LHC running by the end of 2018 to 3000 fb ‑1 by around 2035 for ATLAS and CMS. The challenge of coping with the HL-LHC instantaneous and integrated luminosity, along with the associated radiation levels, requires further major changes to the ATLAS detector. The designs are developing rapidly for a new all-silicon tracker, significant upgrades of the calorimeter and muon systems, as well as improved triggers and data acquisition. ATLAS is also examining potential benefits of extensions to larger pseudorapidity, particularly in tracking and muon systems. This report summarizes various improvements to the ATLAS detector required to cope with the anticipated evolution of the LHC luminosity during this decade and the next. A brief overview is also given on physics prospects with a pp centre-of-mass energy of 14 TeV.

  12. MUON DETECTORS: RPC

    CERN Multimedia

    G. Iaselli

    During the last 3 months the RPC group has made impressive improvements in the refinement of the operation tools and understanding of the detector. The full barrel and part of the plus end cap participated systematically to global runs producing millions of trigger on cosmics. The main monitoring tools were robust and efficient in controlling the detector and in diagnosis of problems. After the refinement of the synchronization procedure, detailed studies of the chamber performances, as a function of high voltage and front-end threshold, were pursued. In parallel, new tools for the prompt analysis were developed which have enabled a fast check of the data at the CMS Centre. This effort has been very valuable since it has helped in discovering many minor bugs in the reconstruction software and database which are now being fixed. Unfortunately, a large part of the RE2 station has developed increasing operational current. Some preliminary investigation leads to the conclusion that the serial gas circulation e...

  13. MUON DETECTORS: CSC

    CERN Multimedia

    Richard Breedon

    Following the opening of the CMS detector, commissioning of the cathode strip chamber (CSC) system resumed in earnest. Some on-chamber electronics problems could be fixed on the positive endcap when each station became briefly accessible as the steel yokes were peeled off. There was no opportunity to work on the negative endcap chambers during opening; this had to wait instead until the yokes were again separated and the stations accessible during closing. In March, regular detector-operating shifts were resumed every weekday evening during which Local Runs were taken using cosmic rays to monitor and validate repairs and improvements that had taken place during the day. Since April, the CSC system has been collecting cosmic data under shift supervision 24 hours a day on weekdays, and 24/7 operation began in early June. The CSC system arranged shifts for continuous running in the entire first half of 2009. One reward of this effort is that every chamber of the CSC system is alive and recording events. There...

  14. MUON DETECTORS: DT

    CERN Multimedia

    C. Fernandez Bedoya and M. Dallavalle

    2010-01-01

    The DT system operation since the 2010 LHC start up is remarkably smooth.
 All parts of the system have behaved very satisfactorily in the last two months of operation with LHC pp collisions. Disconnected HV channels remain at the level of 0.1%, and the loss in detector acceptance because of failures in the readout and Trigger electronics is about 0.4%. The DT DCS-LHC handshake mechanism, which was strengthened after the short 2009 LHC run, operates without major problems. A problem arose with the opto-receivers of the trigger links connecting the detector to USC; the receivers would unlock from transmission for specific frequencies of the LHC lock, in particular during the LHC ramp. For relocking the TX and RX a “re-synch” command had to be issued. The source of the problem has been isolated and cured in the Opto-RX boards and now the system is stable. The Theta trigger chain also has been commissioned and put in operation. Several interventions on the system have been made, pro...

  15. The TALE Fluorescence Detectors

    Science.gov (United States)

    Jui, Charles

    2009-05-01

    The TALE fluorescence detectors are designed to extend the threshold for fluorescence observation by TA down to 3x10^16 eV. It will comprise two main components. The first is a set of 24 telescopes working in stereo, with an existing TA FD station at ˜6 km separation. These will cover between 3-31 degrees in elevation and have azimuthal coverage maximizing the stereo aperture in the 10^18-10^19 eV energy range. The second component consists of 15 telescopes equipped with 4m diameter mirrors and covering the sky between 31 and 73 degrees in elevation. The larger mirror size pushes the physics threshold down to 3x10^16 eV, and provides view of the shower maximum for the lower energy events. The Tower detector will cover one quadrant in azimuth and operate in hybrid mode with the TALE infill array to provide redundant composition measurements from both shower maximum information and muon-to-electron ratio.

  16. Tomography of Spatial Mode Detectors

    CERN Document Server

    Bobrov, Ivan; Markov, Anton; Straupe, Stanislav; Kulik, Sergey

    2014-01-01

    Transformation and detection of photons in higher-order spatial modes usually requires complicated holographic techniques. Detectors based on spatial holograms suffer from non-idealities and should be carefully calibrated. We report a novel method for analyzing the quality of projective measurements in spatial mode basis inspired by quantum detector tomography. It allows us to calibrate the detector response using only gaussian beams. We experimentally investigate the inherent inaccuracy of the existing methods of mode transformation and provide a full statistical reconstruction of the POVM (positive operator valued measure) elements for holographic spatial mode detectors.

  17. VNR CMS Pixel detector replacement

    CERN Multimedia

    2017-01-01

    Joel Butler, spokesperson of the CMS collaboration explains how a team from many different partner institutes installed a new detector in CMS. This detector is the silicon pixel detector and they’ve been working on it for about five years, to replace one of our existing detectors. This detectors measures particles closer to the beam than any of the other components of this huge detector behind me. It gives us the most precise picture of tracks as they come out of the collisions and expand and travel through the detector. This particular device has twice as many pixels, 120 million, as opposed to about 68 million in the old detector and it can take data faster and pump it out to the analysis more quickly. 00’53’’ Images of the descent, insertion and installation of first piece of the Pixel detector on Tue Feb 28. Images of the descent, insertion and installation of second piece of the Pixel and the two cylinders being joined.

  18. Position-sensitive superconductor detectors

    Science.gov (United States)

    Kurakado, M.; Taniguchi, K.

    2016-12-01

    Superconducting tunnel junction (STJ) detectors and superconducting transition- edge sensors (TESs) are representative superconductor detectors having energy resolutions much higher than those of semiconductor detectors. STJ detectors are thin, thereby making it suitable for detecting low-energy X rays. The signals of STJ detectors are more than 100 times faster than those of TESs. By contrast, TESs are microcalorimeters that measure the radiation energy from the change in the temperature. Therefore, signals are slow and their time constants are typically several hundreds of μs. However, TESs possess excellent energy resolutions. For example, TESs have a resolution of 1.6 eV for 5.9-keV X rays. An array of STJs or TESs can be used as a pixel detector. Superconducting series-junction detectors (SSJDs) comprise multiple STJs and a single-crystal substrate that acts as a radiation absorber. SSJDs are also position sensitive, and their energy resolutions are higher than those of semiconductor detectors. In this paper, we give an overview of position-sensitive superconductor detectors.

  19. SU-C-201-03: Coded Aperture Gamma-Ray Imaging Using Pixelated Semiconductor Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, S [Wayne State University, Detroit, MI (United States); Kaye, W; Jaworski, J [H3D, Inc., Ann Arbor, MI (United States); He, Z [University of Michigan, Ann Arbor, MI (United States)

    2015-06-15

    Purpose: Improved localization of gamma-ray emissions from radiotracers is essential to the progress of nuclear medicine. Polaris is a portable, room-temperature operated gamma-ray imaging spectrometer composed of two 3×3 arrays of thick CdZnTe (CZT) detectors, which detect gammas between 30keV and 3MeV with energy resolution of <1% FWHM at 662keV. Compton imaging is used to map out source distributions in 4-pi space; however, is only effective above 300keV where Compton scatter is dominant. This work extends imaging to photoelectric energies (<300keV) using coded aperture imaging (CAI), which is essential for localization of Tc-99m (140keV). Methods: CAI, similar to the pinhole camera, relies on an attenuating mask, with open/closed elements, placed between the source and position-sensitive detectors. Partial attenuation of the source results in a “shadow” or count distribution that closely matches a portion of the mask pattern. Ideally, each source direction corresponds to a unique count distribution. Using backprojection reconstruction, the source direction is determined within the field of view. The knowledge of 3D position of interaction results in improved image quality. Results: Using a single array of detectors, a coded aperture mask, and multiple Co-57 (122keV) point sources, image reconstruction is performed in real-time, on an event-by-event basis, resulting in images with an angular resolution of ∼6 degrees. Although material nonuniformities contribute to image degradation, the superposition of images from individual detectors results in improved SNR. CAI was integrated with Compton imaging for a seamless transition between energy regimes. Conclusion: For the first time, CAI has been applied to thick, 3D position sensitive CZT detectors. Real-time, combined CAI and Compton imaging is performed using two 3×3 detector arrays, resulting in a source distribution in space. This system has been commercialized by H3D, Inc. and is being acquired for

  20. Avoidance and Potential Remedy Solutions of Chimeras in Reconstructing the Phylogeny of Aphids Using the 16S rRNA Gene of Buchnera: A Case in Lachninae (Hemiptera).

    Science.gov (United States)

    Chen, Rui; Wang, Zhe; Chen, Jing; Qiao, Ge-Xia

    2015-08-25

    It is known that PCR amplification of highly homologous genes from complex DNA mixtures can generate a significant proportion of chimeric sequences. The 16S rRNA gene is not only widely used in estimating the species diversity of endosymbionts in aphids but also used to explore the co-diversification of aphids and their endosymbionts. Thus, chimeric sequences may lead to the discovery of non-existent endosymbiont species and mislead Buchnera-based phylogenetic analysis that lead to false conclusions. In this study, a high probability (6.49%) of chimeric sequence occurrence was found in the amplified 16S rRNA gene sequences of endosymbionts from aphid species in the subfamily Lachninae. These chimeras are hybrid products of multiple parent sequences from the dominant species of endosymbionts in each corresponding host. It is difficult to identify the chimeric sequences of a new or unidentified species due to the high variability of their main parent, Buchnera aphidicola, and because the chimeric sequences can confuse the phylogenetic analysis of 16S rRNA gene sequences. These chimeras present a challenge to Buchnera-based phylogenetic research in aphids. Thus, our study strongly suggests that using appropriate methods to detect chimeric 16S rRNA sequences may avoid some false conclusions in endosymbiont-based aphid research.

  1. Generation of anti-idiotype scFv for pharmacokinetic measurement in lymphoma patients treated with chimera anti-CD22 antibody SM03.

    Directory of Open Access Journals (Sweden)

    Qi Zhao

    Full Text Available Pre-clinical and clinical studies of therapeutic antibodies require highly specific reagents to examine their immune responses, bio-distributions, immunogenicity, and pharmacodynamics in patients. Selective antigen-mimicking anti-idiotype antibody facilitates the assessment of therapeutic antibody in the detection, quantitation and characterization of antibody immune responses. Using mouse specific degenerate primer pairs and splenocytic RNA, we generated an idiotype antibody-immunized phage-displayed scFv library in which an anti-idiotype antibody against the therapeutic chimera anti-CD22 antibody SM03 was isolated. The anti-idiotype scFv recognized the idiotype of anti-CD22 antibody and inhibited binding of SM03 to CD22 on Raji cell surface. The anti-idiotype scFv was subsequently classified as Ab2γ type. Moreover, our results also demonstrated firstly that the anti-idiotype scFv could be used for pharmacokinetic measurement of circulating residual antibody in lymphoma patients treated with chimera anti-CD22 monoclonal antibody SM03. Of important, the present approach could be easily adopted to generate anti-idiotype antibodies for therapeutic antibodies targeting membrane proteins, saving the cost and time for producing a soluble antigen.

  2. Neutron detector and fabrication method thereof

    Energy Technology Data Exchange (ETDEWEB)

    Bhandari, Harish B.; Nagarkar, Vivek V.; Ovechkina, Olena E.

    2016-08-16

    A neutron detector and a method for fabricating a neutron detector. The neutron detector includes a photodetector, and a solid-state scintillator operatively coupled to the photodetector. In one aspect, the method for fabricating a neutron detector includes providing a photodetector, and depositing a solid-state scintillator on the photodetector to form a detector structure.

  3. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    Z. Szillasi and G. Gomez.

    2013-01-01

    When CMS is opened up, major components of the Link and Barrel Alignment systems will be removed. This operation, besides allowing for maintenance of the detector underneath, is needed for making interventions that will reinforce the alignment measurements and make the operation of the alignment system more reliable. For that purpose and also for their general maintenance and recalibration, the alignment components will be transferred to the Alignment Lab situated in the ISR area. For the track-based alignment, attention is focused on the determination of systematic uncertainties, which have become dominant, since now there is a large statistics of muon tracks. This will allow for an improved Monte Carlo misalignment scenario and updated alignment position errors, crucial for high-momentum muon analysis such as Z′ searches.

  4. Chemical aerosol Raman detector

    Science.gov (United States)

    Aggarwal, R. L.; Farrar, L. W.; Di Cecca, S.; Amin, M.; Perkins, B. G.; Clark, M. L.; Jeys, T. H.; Sickenberger, D. W.; D'Amico, F. M.; Emmons, E. D.; Christesen, S. D.; Kreis, R. J.; Kilper, G. K.

    2017-03-01

    A sensitive chemical aerosol Raman detector (CARD) has been developed for the trace detection and identification of chemical particles in the ambient atmosphere. CARD includes an improved aerosol concentrator with a concentration factor of about 40 and a CCD camera for improved detection sensitivity. Aerosolized isovanillin, which is relatively safe, has been used to characterize the performance of the CARD. The limit of detection (SNR = 10) for isovanillin in 15 s has been determined to be 1.6 pg/cm3, which corresponds to 6.3 × 109 molecules/cm3 or 0.26 ppb. While less sensitive, CARD can also detect gases. This paper provides a more detailed description of the CARD hardware and detection algorithm than has previously been published.

  5. Direction sensitive neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Ahlen, Steven; Fisher, Peter; Dujmic, Denis; Wellenstein, Hermann F.; Inglis, Andrew

    2017-01-31

    A neutron detector includes a pressure vessel, an electrically conductive field cage assembly within the pressure vessel and an imaging subsystem. A pressurized gas mixture of CF.sub.4, .sup.3He and .sup.4He at respective partial pressures is used. The field cage establishes a relatively large drift region of low field strength, in which ionization electrons generated by neutron-He interactions are directed toward a substantially smaller amplification region of substantially higher field strength in which the ionization electrons undergo avalanche multiplication resulting in scintillation of the CF.sub.4 along scintillation tracks. The imaging system generates two-dimensional images of the scintillation patterns and employs track-finding to identify tracks and deduce the rate and direction of incident neutrons. One or more photo-multiplier tubes record the time-profile of the scintillation tracks permitting the determination of the third coordinate.

  6. Radiation detector with spodumene

    Energy Technology Data Exchange (ETDEWEB)

    D' Amorim, Raquel Aline P.O.; Lima, Hestia Raissa B.R.; Souza, Susana O. [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. de Fisica; Sasaki, Jose M., E-mail: sasaki@fisica.ufc.b [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Fisica; Caldas, Linda V.E., E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    In this work, {beta}-spodumene potentiality as a radiation detector was evaluated by making use of thermoluminescence (TL) and thermally stimulated exoelectron emission (TSEE) techniques. The pellets were obtained from the {beta}-spodumene powder mixed with Teflon followed by a sintering process of thermal treatments of 300 deg/30 min and 400 deg/1.5 h. The samples were irradiated in standard gamma radiation beams with doses between 5 Gy and 10 kGy. The TL emission curve showed a prominent peak at 160 deg and in the case of TSEE a prominent peak at 145 Celsius approximately. Initial results show that the material is promising for high-dose dosimetry. (author)

  7. Pixelated gamma detector

    Energy Technology Data Exchange (ETDEWEB)

    Dolinsky, Sergei Ivanovich; Yanoff, Brian David; Guida, Renato; Ivan, Adrian

    2016-12-27

    A pixelated gamma detector includes a scintillator column assembly having scintillator crystals and optical transparent elements alternating along a longitudinal axis, a collimator assembly having longitudinal walls separated by collimator septum, the collimator septum spaced apart to form collimator channels, the scintillator column assembly positioned adjacent to the collimator assembly so that the respective ones of the scintillator crystal are positioned adjacent to respective ones of the collimator channels, the respective ones of the optical transparent element are positioned adjacent to respective ones of the collimator septum, and a first photosensor and a second photosensor, the first and the second photosensor each connected to an opposing end of the scintillator column assembly. A system and a method for inspecting and/or detecting defects in an interior of an object are also disclosed.

  8. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    G. Gomez

    2011-01-01

    A new set of muon alignment constants was approved in August. The relative position between muon chambers is essentially unchanged, indicating good detector stability. The main changes concern the global positioning of the barrel and of the endcap rings to match the new Tracker geometry. Detailed studies of the differences between track-based and optical alignment of DTs have proven to be a valuable tool for constraining Tracker alignment weak modes, and this information is now being used as part of the alignment procedure. In addition to the “split-cosmic” analysis used to investigate the muon momentum resolution at high momentum, a new procedure based on reconstructing the invariant mass of di-muons from boosted Zs is under development. Both procedures show an improvement in the momentum precision of Global Muons with respect to Tracker-only Muons. Recent developments in track-based alignment include a better treatment of the tails of residual distributions and accounting for correla...

  9. Particle detector spatial resolution

    Science.gov (United States)

    Perez-Mendez, V.

    1992-12-15

    Method and apparatus for producing separated columns of scintillation layer material, for use in detection of X-rays and high energy charged particles with improved spatial resolution is disclosed. A pattern of ridges or projections is formed on one surface of a substrate layer or in a thin polyimide layer, and the scintillation layer is grown at controlled temperature and growth rate on the ridge-containing material. The scintillation material preferentially forms cylinders or columns, separated by gaps conforming to the pattern of ridges, and these columns direct most of the light produced in the scintillation layer along individual columns for subsequent detection in a photodiode layer. The gaps may be filled with a light-absorbing material to further enhance the spatial resolution of the particle detector. 12 figs.

  10. Space-based detectors

    DEFF Research Database (Denmark)

    Sesana, A.; Weber, W. J.; Killow, C. J.;

    2014-01-01

    The parallel session C5 on Space-Based Detectors gave a broad overview over the planned space missions related to gravitational wave detection. Overviews of the revolutionary science to be expected from LISA was given by Alberto Sesana and Sasha Buchman. The launch of LISA Pathfinder (LPF...... bench of LPF was presented by Christian Killow and the performance of the LPF optical metrology system by Paul McNamara. While LPF will not yet be sensitive to gravitational waves, it may nevertheless be used to explore fundamental physics questions, which was discussed by Michele Armano. Some parts....... Using atom interferometry for gravitational wave detection has also been recently proposed, and it was critically reviewed by Peter Bender. In the nearer future, the launch of GRACE Follow-On (for Earth gravity observation) is scheduled for 2017, and it will include a Laser Ranging Interferometer...

  11. Alpine Pixel Detector Layout

    CERN Document Server

    Delebecque, P; The ATLAS collaboration; Geffroy, N; Massol, N; Rambure, T; Todorov, T

    2013-01-01

    A description of an optimized layout of pixel sensors based on a stave that combines both barrel and endcap module orientations. The mechanical stiffness of the structure is provided by carbon fiber shells spaced by carbon foam. The cooling of the modules is provided by two-phase $CO_{2}$ flowing in a thin titanium pipe glued inside the carbon fiber foam. The electrical services of all modules are provided by a single stave flex. This layout eliminates the need for separate barrel and endcap detector structures, and therefore the barrel services material in front of the endcap. The transition from barrel to endcap module orientation is optimized separately for each layer in order to minimize the active pixel area and the traversed material. The sparse module spacing in the endcap part of the stave allows for multiple fixation points, and for a stiff overall structure composed only of staves interconnected by stiff disks.

  12. Space-based detectors

    Science.gov (United States)

    Sesana, A.; Weber, W. J.; Killow, C. J.; Perreur-Lloyd, M.; Robertson, D. I.; Ward, H.; Fitzsimons, E. D.; Bryant, J.; Cruise, A. M.; Dixon, G.; Hoyland, D.; Smith, D.; Bogenstahl, J.; McNamara, P. W.; Gerndt, R.; Flatscher, R.; Hechenblaikner, G.; Hewitson, M.; Gerberding, O.; Barke, S.; Brause, N.; Bykov, I.; Danzmann, K.; Enggaard, A.; Gianolio, A.; Vendt Hansen, T.; Heinzel, G.; Hornstrup, A.; Jennrich, O.; Kullmann, J.; Møller-Pedersen, S.; Rasmussen, T.; Reiche, J.; Sodnik, Z.; Suess, M.; Armano, M.; Sumner, T.; Bender, P. L.; Akutsu, T.; Sathyaprakash, B. S.

    2014-12-01

    The parallel session C5 on Space-Based Detectors gave a broad overview over the planned space missions related to gravitational wave detection. Overviews of the revolutionary science to be expected from LISA was given by Alberto Sesana and Sasha Buchman. The launch of LISA Pathfinder (LPF) is planned for 2015. This mission and its payload "LISA Technology Package" will demonstrate key technologies for LISA. In this context, reference masses in free fall for LISA, and gravitational physics in general, was described by William Weber, laser interferometry at the pico-metre level and the optical bench of LPF was presented by Christian Killow and the performance of the LPF optical metrology system by Paul McNamara. While LPF will not yet be sensitive to gravitational waves, it may nevertheless be used to explore fundamental physics questions, which was discussed by Michele Armano. Some parts of the LISA technology that are not going to be demonstrated by LPF, but under intensive development at the moment, were presented by Oliver Jennrich and Oliver Gerberding. Looking into the future, Japan is studying the design of a mid-frequency detector called DECIGO, which was discussed by Tomotada Akutsu. Using atom interferometry for gravitational wave detection has also been recently proposed, and it was critically reviewed by Peter Bender. In the nearer future, the launch of GRACE Follow-On (for Earth gravity observation) is scheduled for 2017, and it will include a Laser Ranging Interferometer as technology demonstrator. This will be the first inter-spacecraft laser interferometer and has many aspects in common with the LISA long arm, as discussed by Andrew Sutton.

  13. The SPICE Detector at ISAC

    Directory of Open Access Journals (Sweden)

    Garnsworthy A.B.

    2013-12-01

    Full Text Available A new ancillary detector system for the TIGRESS HPGe array called SPectrometer for Internal Conversion Electrons (SPICE is currently under development. SPICE consists of a segmented electron detector, photon shield and a permanent magnetic lens. SPICE will enable in-beam electron spectroscopy and, in coupling to the TIGRESS HPGe array, coincident gamma-electron spectroscopy with stable and radioactive beams.

  14. Micromegas detector developments for MIMAC

    CERN Document Server

    Ferrer-Ribas, E; Calvet, D; Colas, P; Druillole, F; Giomataris, Y; Iguaz, F J; Mols, J P; Pancin, J; Papaevangelou, T; Billard, J; Bosson, G; Bouly, J L; Bourrion, O; Fourel, Ch; Grignon, C; Guillaudin, O; Mayet, F; Richer, J P; Santos, D; Golabek, C; Lebreton, L

    2011-01-01

    The aim of the MIMAC project is to detect non-baryonic Dark Matter with a directional TPC. The recent Micromegas efforts towards building a large size detector will be described, in particular the characterization measurements of a prototype detector of 10 $\\times$ 10 cm$^2$ with a 2 dimensional readout plane. Track reconstruction with alpha particles will be shown.

  15. ALICE Time Of Flight Detector

    CERN Multimedia

    Alici, A

    2013-01-01

    Charged particles in the intermediate momentum range are identified in ALICE by the Time Of Flight (TOF) detector. The time measurement with the TOF, in conjunction with the momentum and track length measured by the tracking detector, is used to calculate the particle mass.

  16. ENSTAR detector for -mesic studies

    Indian Academy of Sciences (India)

    A Chatterjee; B J Roy; V Jha; P Shukla; H Machnder; GEM Collaboration

    2006-05-01

    We have initiated a search for a new type of nuclear matter, the -mesic nucleus, using beams from the multi-GeV hadron facility, COSY at Juelich, Germany. A large acceptance scintillator detector, ENSTAR has been designed and built at BARC, Mumbai and fully assembled and tested at COSY. A test run for calibration and evaluation has been completed. In this contribution we present the design and technical details of the ENSTAR detector and how it will be used to detect protons and pions (the decay products of -mesic bound state). The detector is made of plastic scintillators arranged in three concentric cylindrical layers. The readout of the detectors is by means of optical fibres. The layers are used to generate - spectra for particle identification and total energy information of stopped particles. The granularity of the detector allows for position ( and ) determination making the event reconstruction kinematically complete.

  17. The 150 ns detector project: Progress with small detectors

    Science.gov (United States)

    Warburton, W. K.; Russell, S. R.; Kleinfelder, Stuart A.; Segal, Julie

    1994-09-01

    This project's long term goal is to develop a pixel area detector capable of 6 MHz frame rates (150 ns/frame). Our milestones toward this goal are: a single pixel, 1 × 256 1D and 8 × 8 2D detectors, 256 × 256 2D detectors and, finally, 1024 × 1024 2D detectors. The design strategy is to supply a complete electronics chain (resetting preamp, selectable gain amplifier, analog-to-digital converter (ADC), and memory) for each pixel. In the final detectors these will all be custom integrated circuits. The front end preamplifiers are being integrated first, since their design and performance are both the most unusual and also critical to the project's success. Similarly, our early work is also concentrating on devising and perfecting detector structures which are thick enough (1 mm) to absorb over 99% of the incident X-rays in the energy range of interest. In this paper we discuss our progress toward the 1 × 256 1D and 8 × 8 2D detectors. We have fabricated sample detectors at Stanford's Center for Integrated Systems and are preparing both to test them individually and to wirebond them to the preamplifier samples to produce our first working small 1D and 2D detectors. We will describe our solutions to the design problems associated with collecting charge in less than 30 ns from 1 mm thick pixels in high resistivity silicon. We have constructed and tested the front end of our preamplifier design using a commercial 1.2 μm CMOS technology and are moving on to produce a few channels of the complete preamplifier, including a switchable gain stage and output stage. We will discuss both the preamplifier design and our initial test results.

  18. Recent detector developments at SINTEF (industrial presentation)

    Science.gov (United States)

    Sundby Avset, Berit; Evensen, Lars; Uri Jensen, Geir; Mo, Sjur; Kari Schjølberg-Henriksen; Westgaard, Trond

    1998-02-01

    Results from SINTEF's research on radiation hardness of silicon detectors, thin silicon detectors, silicon drift devices, reach-through avalanche photodiodes, and detectors with thin dead layers are presented.

  19. Acquisition System and Detector Interface for Power Pulsed Detectors

    CERN Document Server

    Cornat, R

    2012-01-01

    A common DAQ system is being developed within the CALICE collaboration. It provides a flexible and scalable architecture based on giga-ethernet and 8b/10b serial links in order to transmit either slow control data, fast signals or read out data. A detector interface (DIF) is used to connect detectors to the DAQ system based on a single firmware shared among the collaboration but targeted on various physical implementations. The DIF allows to build, store and queue packets of data as well as to control the detectors providing USB and serial link connectivity. The overall architecture is foreseen to manage several hundreds of thousands channels.

  20. Acquisition System and Detector Interface for Power Pulsed Detectors

    Science.gov (United States)

    Cornat, Rémi; CALICE Colaboration

    A common DAQ system is being developed within the CALICE collaboration. It provides a flexible and scalable architecture based on giga-ethernet and 8b/10b serial links in order to transmit either slow control data, fast signals or read out data. A detector interface (DIF) is used to connect detectors to the DAQ system based on a single firmware shared among the collaboration but targeted on various physical implementations. The DIF allows to build, store and queue packets of data as well as to control the detectors providing USB and serial link connectivity. The overall architecture is foreseen to manage several hundreds of thousands channels.

  1. PNA Peptide chimerae

    DEFF Research Database (Denmark)

    Koch, T.; Næsby, M.; Wittung, P.;

    1995-01-01

    Radioactive labelling of PNA has been performed try linking a peptide segment to the PNA which is substrate for protein kinase A. The enzymatic phosphorylation proceeds in almost quantitative yields.......Radioactive labelling of PNA has been performed try linking a peptide segment to the PNA which is substrate for protein kinase A. The enzymatic phosphorylation proceeds in almost quantitative yields....

  2. Chimeras: an ethical consideration

    Directory of Open Access Journals (Sweden)

    H.J.G. Zandman

    2011-07-01

    Full Text Available Scientists have started with experimentation that raises difficult ethical questions. It comprises taking material from the human blueprint (DNA and inserting this in various test animals. The purpose of such research is noble, namely the alleviation of hu- man suffering. Yet the ethical ramifications of blending the hu- man and animal genome are significant, especially for Chris- tians. The creation of all living entities after their kind and the image-bearing dignity attributed to man both come under se- vere ethical stress for those who presuppose divine order in God’s ecology.  For non-Christians the philosophical dilemma ought not to exist in the ethical sense if applied at the purest level. If the human is merely a kind of animal, along with and ontologically not diffe- rent from other animals, there is little logical reason to object to chimeric research apart from a concern about what such re- search and application might do to the order of life pragmati- cally. However, many non-Christian do object. Man is made in God’s image and the concept of human dignity and a universal sense of right and wrong still binds Christians and non-Chris- tians when considering ethics in the field of chimeric research. As the mixing of human stem cells with embryonic animals takes place, certain non-Christian authors protest that human dignity is being diminished and the animal essence is being vio- lated.

  3. Detector instrumentation for nuclear fission studies

    Indian Academy of Sciences (India)

    Akhil Jhingan

    2015-09-01

    The study of heavy-ion-induced fusion–fission reactions require nuclear instrumentation that include particle detectors such as proportional counters, ionization chambers, silicon detectors, scintillation detectors, etc., and the front-end electronics for these detectors. Using the detectors mentioned above, experimental facilities have been developed for carrying out fusion–fission experiments. This paper reviews the development of detector instrumentation at IUAC.

  4. Plastic neutron detectors.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Tiffany M.S; King, Michael J.; Doty, F. Patrick

    2008-12-01

    This work demonstrated the feasibility and limitations of semiconducting {pi}-conjugated organic polymers for fast neutron detection via n-p elastic scattering. Charge collection in conjugated polymers in the family of substituted poly(p-phenylene vinylene)s (PPV) was evaluated using band-edge laser and proton beam ionization. These semiconducting materials can have high H/C ratio, wide bandgap, high resistivity and high dielectric strength, allowing high field operation with low leakage current and capacitance noise. The materials can also be solution cast, allowing possible low-cost radiation detector fabrication and scale-up. However, improvements in charge collection efficiency are necessary in order to achieve single particle detection with a reasonable sensitivity. The work examined processing variables, additives and environmental effects. Proton beam exposure was used to verify particle sensitivity and radiation hardness to a total exposure of approximately 1 MRAD. Conductivity exhibited sensitivity to temperature and humidity. The effects of molecular ordering were investigated in stretched films, and FTIR was used to quantify the order in films using the Hermans orientation function. The photoconductive response approximately doubled for stretch-aligned films with the stretch direction parallel to the electric field direction, when compared to as-cast films. The response was decreased when the stretch direction was orthogonal to the electric field. Stretch-aligned films also exhibited a significant sensitivity to the polarization of the laser excitation, whereas drop-cast films showed none, indicating improved mobility along the backbone, but poor {pi}-overlap in the orthogonal direction. Drop-cast composites of PPV with substituted fullerenes showed approximately a two order of magnitude increase in photoresponse, nearly independent of nanoparticle concentration. Interestingly, stretch-aligned composite films showed a substantial decrease in

  5. ATLAS Forward Detectors and Physics

    CERN Document Server

    Soni, N

    2010-01-01

    In this communication I describe the ATLAS forward physics program and the detectors, LUCID, ZDC and ALFA that have been designed to meet this experimental challenge. In addition to their primary role in the determination of ATLAS luminosity these detectors - in conjunction with the main ATLAS detector - will be used to study soft QCD and diffractive physics in the initial low luminosity phase of ATLAS running. Finally, I will briefly describe the ATLAS Forward Proton (AFP) project that currently represents the future of the ATLAS forward physics program.

  6. CLIC Detector and Physics Status

    CERN Document Server

    Van Der Kolk, Naomi

    2017-01-01

    This contribution to LCWS2016 presents recent developments within the CLICdp collaboration. An updated scenario for the staged operation of CLIC has been published; the accelerator will operate at 380 GeV, 1.5 TeV and 3 TeV. The lowest energy stage is optimised for precision Higgs and top physics, while the higher energy stages offer extended Higgs and BSM physics sensitivity. The detector models CLIC_SiD and CLIC_ILD have been replaced by a single optimised detector; CLICdet. Performance studies and R&D in technologies to meet the requirements for this detector design are ongoing.

  7. Thermoluminescent Detectors in Mixed Fields

    CERN Document Server

    Mala, P; Biskup, B; Roeed, K

    2012-01-01

    This note reports on using of thermoluminescent detectors for radiation monitoring in the LHC tunnel and in the shielded areas around the tunnel. The accumulated annual doses in these areas vary a lot so a dosimeter used there should cover a large dose range. TL detectors can measure dose from 0.1 mGy to few kGy (with a recently proposed new technique which needs more studies up to 1 MGy). This report presents studies of these detectors in mixed fields similar to radiation field in the LHC and the possible usage of their results for calculation of high energy hadron and thermal neutron fluence.

  8. The CDF Silicon Vertex Detector

    Energy Technology Data Exchange (ETDEWEB)

    Tkaczyk, S.; Carter, H.; Flaugher, B. [and others

    1993-09-01

    A silicon strip vertex detector was designed, constructed and commissioned at the CDF experiment at the Tevatron collider at Fermilab. The mechanical design of the detector, its cooling and monitoring are presented. The front end electronics employing a custom VLSI chip, the readout electronics and various components of the SVX system are described. The system performance and the experience with the operation of the detector in the radiation environment are discussed. The device has been taking colliding beams data since May of 1992, performing at its best design specifications and enhancing the physics program of CDF.

  9. Detector for a linear collider

    CERN Document Server

    Mnich, J

    2003-01-01

    The proposals under discussion for a new e^{+}e^{-} linear collider with centre-of-mass energies around 1 TeV include designs for large detectors with unprecedented performances in energy, momentum and position resolution. These very stringent requirements are dictated by the precision measurements aimed at this collider to complement the exploratory experiments at the Large Hadron Collider. Here a status report on detector R&D projects for the liner collider is given focused on the technologies under study for the vertex detector, the large tracking chamber and the calorimeters.

  10. Requirements on high resolution detectors

    Energy Technology Data Exchange (ETDEWEB)

    Koch, A. [European Synchrotron Radiation Facility, Grenoble (France)

    1997-02-01

    For a number of microtomography applications X-ray detectors with a spatial resolution of 1 {mu}m are required. This high spatial resolution will influence and degrade other parameters of secondary importance like detective quantum efficiency (DQE), dynamic range, linearity and frame rate. This note summarizes the most important arguments, for and against those detector systems which could be considered. This article discusses the mutual dependencies between the various figures which characterize a detector, and tries to give some ideas on how to proceed in order to improve present technology.

  11. MUON DETECTORS: DT

    CERN Multimedia

    C. Fernandez Bedoya

    2012-01-01

      The major activity of the DT group during this Year-End Technical Stop has been the reworking of LV modules. It has been a large campaign, carefully planned, to try to solve, once and for all, the long-standing problem of Anderson Power connectors overheating. The solution involved removing the 140 CAEN modules from the detector (6.5 kg each), soldering of “pigtails” in a temporary workshop in USC, and thorough testing of all the modules in a local system installed in USC. The operation has been satisfactorily smooth, taking into account the magnitude of the intervention. The system is now back in good shape and ready for commissioning. In addition, HV boards have been cleaned up, HV USC racks have been equipped with water detection cables, and the gas and HV have been switched back on smoothly. Other significant activities have also taken place during this YETS, such as the installation of a new and faster board for the Minicrates secondary link and the migration to Scienti...

  12. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    S. Szillasi

    2013-01-01

    The CMS detector has been gradually opened and whenever a wheel became exposed the first operation was the removal of the MABs, the sensor structures of the Hardware Barrel Alignment System. By the last days of June all 36 MABs have arrived at the Alignment Lab at the ISR where, as part of the Alignment Upgrade Project, they are refurbished with new Survey target holders. Their electronic checkout is on the way and finally they will be recalibrated. During LS1 the alignment system will be upgraded in order to allow more precise reconstruction of the MB4 chambers in Sector 10 and Sector 4. This requires new sensor components, so called MiniMABs (pictured below), that have already been assembled and calibrated. Image 6: Calibrated MiniMABs are ready for installation For the track-based alignment, the systematic uncertainties of the algorithm are under scrutiny: this study will enable the production of an improved Monte Carlo misalignment scenario and to update alignment position errors eventually, crucial...

  13. MUON DETECTORS: CSC

    CERN Multimedia

    R. Breedon

    Figure 2: Five ME4/2 chambers mounted on the +endcap. At the end of June, five large, outer cathode strip chambers (CSC) that were produced as spares during the original production were mounted on part of the disk space reserved for ME4/2 on the positive endcap (Fig. 2). The chambers were cabled, attached to services, and fully integrated and commissioned into the CSC DAQ and trigger systems. Comprising almost a full trigger sector, CMS will be able to test the significant improvement the trigger efficiency of the EMU system that the presence of the full ME4/2 ring is expected to bring. The return of beam in November was observed as “splash” events in the CSCs in which the detectors were showered with a huge number of particles at the same time. Although the CSCs were operating at a lower standby voltage the multiple hits on a strips could not be individually distinguished.&am...

  14. MUON DETECTORS: RPC

    CERN Multimedia

    G. Iaselli

    The RPC group has invested a large effort in the study of trigger spikes observed during CRAFT data taking. The chambers are susceptible to noise generated by the flickering of fluorescent and projector lamps in the cavern (with magnetic field on). Soon after the end of CRAFT, it was possible to reproduce the phenomena using a waveform generator and to study possible modifications to be implemented in the grounding schema. Hardware actions have been already taken in order to reduce the detector sensitivity: star washers on the chamber front panels and additional shielding have been added where possible. During the shutdown maintenance activity many different problems were tackled on the barrel part. A few faulty high voltage connector/cable problems were fixed; now only two RPC chambers are left with single-gap mode operation. One chamber in YB+2 was replaced due to gas leakage. All the front-end electronic boards were replaced in 3 chambers (stations MB2 and MB3 in YB-2), that had been damaged after the coo...

  15. Hybrid Superconducting Neutron Detectors

    CERN Document Server

    Merlo, V; Cirillo, M; Lucci, M; Ottaviani, I; Scherillo, A; Celentano, G; Pietropaolo, A

    2014-01-01

    A new neutron detection concept is presented that is based on superconductive niobium (Nb) strips coated by a boron (B) layer. The working principle of the detector relies on the nuclear reaction 10B+n $\\rightarrow$ $\\alpha$+ 7Li , with $\\alpha$ and Li ions generating a hot spot on the current-biased Nb strip which in turn induces a superconducting-normal state transition. The latter is recognized as a voltage signal which is the evidence of the incident neutron. The above described detection principle has been experimentally assessed and verified by irradiating the samples with a pulsed neutron beam at the ISIS spallation neutron source (UK). It is found that the boron coated superconducting strips, kept at a temperature T = 8 K and current-biased below the critical current Ic, are driven into the normal state upon thermal neutron irradiation. As a result of the transition, voltage pulses in excess of 40 mV are measured while the bias current can be properly modulated to bring the strip back to the supercond...

  16. MUON DETECTORS: DT

    CERN Multimedia

    R.Carlin

    2010-01-01

    DT operation during 2010 LHC collisions, both in proton-proton and heavy ions, has been outstanding. The DT downtime has been below 0.1% throughout the whole year, mainly caused by the manual Resync commands that took around a minute for being processed. An automatic resynchronisation procedure has been enabled by August 27 and since then the downtime has been negligible (though constantly monitored). The need for these Resync commands is related to sporadic noise events that occasionally fill the RO buffers or unlock the readout links. Their rate is low, in the order of a few per week. Besides that, only one pp collisions run (1 hour 30 minutes run) has been marked as bad for DT, because of an incident with a temperature sensor that triggered a false alarm and powered off one wheel. Nevertheless, quite a large number of interventions (>30) have been made in the cavern during the year, in order to keep such a large fraction of the detector operational. Most of those are due to the overheating of the ...

  17. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2013-01-01

    During LS1, the Resistive Plate Chamber (RPC) collaboration is focusing its efforts on installation and commissioning of the fourth endcap station (RE4) and on the reparation and maintenance of the present system (1100 detectors). The 600 bakelite gaps, needed to build 200 double-gap RE4 chambers are being produced in Korea. Chamber construction and testing sites are located at CERN, in Ghent University, and at BARC (India). At present, 42 chambers have been assembled, 32 chambers have been successfully tested with cosmic rays runs and 7 Super Modules, made by two chambers, have been built at CERN by a Bulgarian/Georgian/Italian team and are now ready to be installed in the positive endcap. The 36 Super Modules needed to complete the positive endcap will be ready in September and installation is scheduled for October 2013. The Link-Board system for RE4 is under construction in Naples. Half of the system has been delivered at CERN in June. Six crates (Link-Board Boxes) and 75 boards, needed to instrument t...

  18. MUON DETECTORS: DT

    CERN Multimedia

    C. Fernandez Bedova and M. Dallavalle

    2010-01-01

    After successful operation during the 2009 LHC run, a number of fixes and improvements were carried out on the DT system the winter shutdown. The main concern was related with the impact of the extensive water leak that happened in October in YE+1. Opening of CMS end-caps allowed the DT crew to check if any Minicrates (containing the first level of readout and trigger electronics) in YB+2 and YB-2 were flooded with water. The affected region from top sectors in YB+2 reaches down to the bottom sectors in YB-2 following the water path in the barrel from end to end. No evidence of water penetration was observed, though the passage of water left oxidation and white streaks on the iron and components. In particular, large signs of oxidation have been seen on the YB-2 MB1 top and bottom stations. Review of the impact in YB+1 remains for future openings of CMS wheels, and at present, effort is focused on setting up the water leak detection system in the detector. Another important issue during this shutd...

  19. MUON DETECTORS: DT

    CERN Multimedia

    I. Redondo

    2011-01-01

    During the second quarter of 2011, the DT system has continued to operate successfully with a high fraction of good channels (>99 %) and causing extremely little downtime to CMS. The high fraction of operated channels did not come for free: DT requested 18 short UXC accesses in the 3 months from March to May 2011. The dominant causes for these interventions were HV related interventions (7), which typically affect a small fraction of a chamber, and interventions for dealing with overheated LV Anderson connectors (7), whose failure could affect larger fractions of the detector (a whole chamber, half a wheel). With respect to the CMS downtime, a successful effort with colleagues from the DT Track Finder of the Level-1 Trigger system allowed to overcome a relatively relevant source of downtime from DTTF FED Out-Of-Sync errors, which would appear randomly during data-taking. The DT group developed a system configuration that would make it possible to reproduce the error without beam, thereby sparing lumin...

  20. MUON DETECTORS: RPC

    CERN Multimedia

    G. Iaselli

    2010-01-01

    During the technical stop, the RPC team was part of the CMS task force team working on bushing replacements in the Endcap cooling system, also validating the repairs in terms of connectivity (HV, LV and signal cables), and gas leak, on RE chambers. In parallel, the RPC team profited from the opportunity to cure several known problems: six chambers with HV problems (1 off + 5 single gaps) were recovered on both gaps; four known HV problems were localized at chamber level; additional temperature sensors were installed on cooling pipes on negative REs; one broken LV module in RE-1 was replaced. During the last month, the RPC group has made big improvements in the operations tools. New trigger supervisor software has substantially reduced the configuration time. Monitoring is now more robust and more efficient in providing prompt diagnostics. The detector has been under central DCS control for two weeks. Improvements have been made to both functionality and documentation and no major problems were found. Beam s...

  1. MUON DETECTORS: CSC

    CERN Multimedia

    J. Hauser

    2011-01-01

    The CSC detector continued to operate well during the March-June 2011 period. As the luminosity has climbed three orders of magnitude, the currents drawn in the CSC high-voltage system have risen correspondingly, and the current trip thresholds have been increased from 1 μA to 5 μA (and 20 in ME1/1 chambers). A possible concern is that a long-lasting and undesirable corona is capable of drawing about 1 μA, and thus may not be detected by causing current trips; on the other hand it is easily dealt with by cycling HV when detected. To better handle coronas, software is being developed to better detect them, although a stumbling block is the instability of current measurements in some of the channels of the CAEN supplies used in ME1/1. A survey of other issues faced by the CSC Operations team was discussed at the 8th June 2011 CSC Operations/DPG meeting (Rakness). The most important issues, i.e. those that have caused a modest amount of downtime, are all being actively addressed. These are:...

  2. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2012-01-01

      2011 data-taking was very satisfactory for both the RPC detector and trigger. The RPC system ran very smoothly in 2011, showing an excellent stability and very high data-tacking efficiency. Data loss for RPC was about 0.37%, corresponding to 19 pb−1. Most of the performance studies, based on 2011 data, are now completed and the results have been already approved by CMS to be presented at the RPC 2012 conference (February 2012 at LNF). During 2011, the number of disconnected chambers increased from six to eight corresponding to 0.8% of the full system, while the single-gap-mode chambers increased from 28 to 31. Most of the problematic chambers are due to bad high-voltage connection and electronic failures that can be solved only during the 2013-2014 Long Shutdown. 98.4% of the electronic channels were operational. The average detection efficiency in 2011 was about 95%, which was the same value measured during the HV scan done at the beginning of the 2011 data-taking. Efficiency has be...

  3. MUON DETECTORS: DT

    CERN Multimedia

    M. Dallavalle

    2013-01-01

    The DT collaboration is undertaking substantial work both for detector maintenance – after three years since the last access to the chambers and their front-end electronics – and upgrade. The most critical maintenance interventions are chambers and Minicrate repairs, which have not begun yet, because they need proper access to each wheel of the CMS barrel, meaning space for handling the big chambers in the few cases where they have to be extracted, and, more in general, free access from cables and thermal shields in the front and back side of the chambers. These interventions are planned for between the coming Autumn until next spring. Meanwhile, many other activities are happening, like the “pigtail” intervention on the CAEN AC/DC converters which has just taken place. The upgrade activities continue to evolve in good accordance with the schedule, both for the theta Trigger Board (TTRB) replacement and for the Sector Collector (SC) relocation from the UXC to the US...

  4. MUON DETECTORS: RPC

    CERN Multimedia

    G. Pugliese

    2010-01-01

    In the second half of 2010 run, the overall behavior of the RPC system has been very satisfactory, both in terms of detector and trigger performance. This result was achieved through interventions by skilled personnel and fine-tuned analysis procedures. The hardware was quite stable: both gas and power systems did not present significant problems during the data-taking period, confirming the high reliability achieved. Only few interventions on some HV or LV channels were necessary during the periodical technical accesses. The overall result is given by the stable percentage of active channels at about 98.5%. The single exception was at beginning of the ion collisions, when it dipped to 97.4% because of the failure of one LV module, although this was recovered after a few days. The control and monitoring software is now more robust and efficient, providing prompt diagnostics on the status of the entire system. Significant efforts were made in collaboration with the CMS cooling team to secure proper working ...

  5. ATLAS Detector Upgrade Prospects

    CERN Document Server

    Dobre, Monica; The ATLAS collaboration

    2016-01-01

    After the successful operation at the centre-of-mass energies of 7 and 8 TeV in 2010-2012, the LHC is ramped up and successfully took data at the centre-of-mass energies of 13 TeV in 2015. Meanwhile, plans are actively advancing for a series of upgrades of the accelerator, culminating roughly ten years from now in the high-luminosity LHC (HL-LHC) project, delivering of the order of five times the LHC nominal instantaneous luminosity along with luminosity levelling. The ultimate goal is to extend the dataset from about few hundred f b −1 expected for LHC running to 3000 f b −1 by around 2035 for ATLAS and CMS. The challenge of coping with the HL-LHC instantaneous and integrated luminosity, along with the associated radiation levels, requires further major changes to the ATLAS detector. The designs are developing rapidly for a new all-silicon tracker, significant upgrades of the calorimeter and muon systems, as well as improved triggers and data acquisition. ATLAS is also examining potential benefits of ext...

  6. ATLAS Detector Upgrade Prospects

    CERN Document Server

    Dobre, Monica; The ATLAS collaboration

    2016-01-01

    After the successful operation at the center-of-mass energies of 7 and 8 TeV in 2010 - 2012, the LHC is ramped up and successfully took data at the center-of-mass energies of 13 TeV in 2015. Meanwhile, plans are actively advancing for a series of upgrades of the accelerator, culminating roughly ten years from now in the high-luminosity LHC (HL-LHC) project, delivering of the order of five times the LHC nominal instantaneous luminosity along with luminosity leveling. The ultimate goal is to extend the dataset from about few hundred fb−1 expected for LHC running to 3000 fb−1 by around 2035 for ATLAS and CMS. The challenge of coping with the HL-LHC instantaneous and integrated luminosity, along with the associated radiation levels, requires further major changes to the ATLAS detector. The designs are developing rapidly for a new all-silicon tracker, significant upgrades of the calorimeter and muon systems, as well as improved triggers and data acquisition. ATLAS is also examining potential benefits of extens...

  7. MUON DETECTORS: RPC

    CERN Multimedia

    Pierluigi Paolucci

    2013-01-01

    In the second part of 2013 the two main activities of the RPC project are the reparation and maintenance of the present system and the construction and installation of the RE4 system. Since the opening of the barrel, repair activities on the gas, high-voltage and electronic systems are being done in parallel, in agreement with the CMS schedule. In YB0, the maintenance of the RPC detector was in the shadow of other interventions, nevertheless the scaffolding turned out to be a good solution for our gas leaks searches. Here we found eight leaking channels for about 100 l/h in total. 10 RPC/DT modules were partially extracted –– 90 cm –– in YB0, YB–1 and YB–2 to allow for the replacement of FE and LV distribution boards. Intervention was conducted on an additional two chambers on the positive endcap to solve LV and threshold control problems. Until now we were able to recover 0.67% of the total number of RPC electronic channels (1.5% of the channels...

  8. MUON DETECTORS: DT

    CERN Multimedia

    M. Dallavalle

    In the past months, the DT electronics has run in a stable and reliable way, demonstrated again through the CRAFT exercise. Operation when the CMS magnetic field was on has been satisfactory. The detector safety control and monitoring is improving constantly as the DT group accumulates running experience. The DT DAQ and DCS systems proved very stable during the intensive CRAFT period. The few issues that were identified by the DCS and on-line monitoring did not prevent the run to continue, so that the record of the DT in the data taking efficiency was very good. The long running period was also used to continue the transition from a system run by experts to one run by shifters, which was in the large part successful. Improvements, mostly in consolidation of error reporting, were identified and will be addressed in the coming shut-down. During the CRAFT data taking, DT triggered about 300 million cosmics with the magnet at 3.8T and the silicon strip tracker in the readout. Although a dedicated configuratio...

  9. MUON DETECTORS: DT

    CERN Multimedia

    I. Redondo Fernandez

    2011-01-01

    The DT system has operated successfully during the entire 2011 data-taking: the fraction of good channels was always >99.4 % and the downtime caused to CMS amounts to a few inverse picobarns. This excellent performance does not come without a price: the DT group requested more than 30 short accesses to the underground experimental cavern (UXC).  A large fraction of interventions was for dealing with overheated LV Anderson connectors, whose failure can affect larger sections of the detector (a whole chamber, or half a wheel of the CMS barrel, etc.). A crash programme for reworking those connections will take place during the Year-End Technical Stop. The system of six vd chambers (VDC) that were installed on the DT exhaust gas line have operated successfully. The VDCs are small drift chambers the size of a shoebox that measure the drift velocity every 10 minutes. Possible deviations from the nominal value could be caused by a contamination of the gas mixture or changes in pressure or temperat...

  10. Ba{anti B}ar status report on the design of a detector for the study of CP violation at PEP-II at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    1993-06-01

    Experiments designed to measure CP-violating asymmetries in the B meson system must emphasize exclusive state reconstruction with the highest possible resolution and efficiency. In the case of B{sup 0} mesons produced in pairs at the {Upsilon}(4S) resonance at an asymmetric e{sup +}e{sup {minus}} storage ring, this capability must be accompanied by precise vertex reconstruction in the direction of the e{sup +}e{sup {minus}} beams (henceforth the z direction). These are difficult requirements, beyond the scope of any existing storage ring detector. The challenge of designing an asymmetric storage ring capable of producing the large number of neutral B meson pairs required to measure CP-violating asymmetries in decays to CP eigenstates has been handsomely met in the PEP-II design. As the first asymmetric e{sup +}e{sup {minus}} storage ring, PEP-II presents a novel set of experimental challenges to a 4{pi} detector. This Status Report describes the design of a new detector fully capable of exploiting the physics opportunities provided by PEP-II.

  11. Efficient generation of germ line transmitting chimeras from C57BL/6N ES cells by aggregation with outbred host embryos.

    Directory of Open Access Journals (Sweden)

    Marina Gertsenstein

    Full Text Available Genetically modified mouse strains derived from embryonic stem (ES cells have become essential tools for functional genomics and biomedical research. Large scale mutagenesis projects are producing libraries of mutant C57BL/6 (B6 ES cells to enable the functional annotation of every gene of the mouse genome. To realize the utility of these resources, efficient and accessible methods of generating mutant mice from these ES cells are necessary. Here, we describe a combination of ICR morula aggregation and a chemically-defined culture medium with widely available and accessible components for the high efficiency generation of germline transmitting chimeras from C57BL/6N ES cells. Together these methods will ease the access of the broader biomedical research community to the publicly available B6 ES cell resources.

  12. Optimization of three-dimensional imaging on in vitro produced porcine blastocysts and chimeras for stem cell testing: A technology report

    DEFF Research Database (Denmark)

    Secher, Jan; Freude, Karla; Li, Rong

    2015-01-01

    Differential staining is an immunocytochemical staining that visualizes trophectoderm (TE) and the inner cell mass (ICM) of the blastocysts. It is used to determine the blastocyst quality, but could also be a useful tool to assess the integration site of injected cells into the early embryo....... This 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 area...... of the ICM they are likely to contribute to the fetus and if they are located in the area of the TE they are likely to contribute to the fetal membranes. In this article, we optimize on methods for embryo staining and mounting so that the exact location of injected stem cells within preimplantation porcine...

  13. Reversal of type 1 diabetes by a new MHC II-peptide chimera: "Single-epitope-mediated suppression" to stabilize a polyclonal autoimmune T-cell process.

    Science.gov (United States)

    Lin, Marvin; Stoica-Nazarov, Cristina; Surls, Jacqueline; Kehl, Margaret; Bona, Constantin; Olsen, Cara; Brumeanu, Teodor D; Casares, Sofia

    2010-08-01

    Polyclonality of self-reactive CD4(+) T cells is the hallmark of several autoimmune diseases like type 1 diabetes. We have previously reported that a soluble dimeric MHC II-peptide chimera prevents and reverses type 1 diabetes induced by a monoclonal diabetogenic T-cell population in double Tg mice [Casares, S. et al., Nat. Immunol. 2002. 3: 383-391]. Since most of the glutamic acid decarboxylase 65 (GAD65)-specific CD4(+) T cells in the NOD mouse are tolerogenic but unable to function in an autoimmune environment, we have activated a silent, monoclonal T-regulatory cell population (GAD65(217-230)-specific CD4(+) T cells) using a soluble I-A(αβ) (g7)/GAD65(217-230)/Fcγ2a dimer, and measured the effect on the ongoing polyclonal diabetogenic T-cell process. Activated GAD65(217-230)-specific T cells and a fraction of the diabetogenic (B(9-23)-specific) T cells were polarized toward the IL-10-secreting T-regulatory type 1-like function in the pancreas of diabetic NOD mice. More importantly, this led to the reversal of hyperglycemia for more than 2 months post-therapy in 80% of mice in the context of stabilization of pancreatic insulitis and improved insulin secretion by the β cells. These findings argue for the stabilization of a polyclonal self-reactive T-cell process by a single epitope-mediated bystander suppression. Dimeric MHC class II-peptide chimeras-like approach may provide rational grounds for the development of more efficient antigen-specific therapies in type 1 diabetes.

  14. Development of a tightly regulated and highly inducible ecdysone receptor gene switch for plants through the use of retinoid X receptor chimeras.

    Science.gov (United States)

    Tavva, Venkata S; Dinkins, Randy D; Palli, Subba R; Collins, Glenn B

    2007-10-01

    Chemical inducible gene regulation systems provide essential tools for the precise regulation of transgene expression in plants and animals. Recent development of a two-hybrid ecdysone receptor (EcR) gene regulation system has solved some of the drawbacks that were associated with the monopartate gene switch. To further improve the versatility of the two-hybrid EcR gene switch for wide spread use in plants, chimeras between Homo sapiens retinoid X receptor (HsRXR) and insect, Locusta migratoria RXR (LmRXR) were tested in tobacco protoplasts as partners with Choristoneura fumiferana EcR (CfEcR) in inducing expression of the luciferase reporter gene. The RXR chimera 9 (CH9) along with CfEcR, in a two-hybrid format gave the best results in terms of low-background expression levels in the absence of ligand and high-induced expression levels of the reporter gene in the presence of nanomolar concentrations of the methoxyfenozide ligand. The performance of CH9 was further tested in corn and soybean protoplasts and the data obtained was compared with the other EcR switches that contained the wild-type LmRXR or HsRXR as EcR partners. In both transient expression studies and stable transformation experiments, the fold induction values obtained with the CH9 switch were several times higher than the values obtained with the other EcR switches containing LmRXR or HsRXR. The new CfEcR two-hybrid gene switch that uses the RXR CH9 as a partner in inducing reporter gene expression provides an efficient, ligand-sensitive and tightly regulated gene switch for plants.

  15. Transient Expression of an LEDGF/p75 Chimera Retargets Lentivector Integration and Functionally Rescues in a Model for X-CGD.

    Science.gov (United States)

    Vets, Sofie; De Rijck, Jan; Brendel, Christian; Grez, Manuel; Bushman, Frederic; Debyser, Zeger; Gijsbers, Rik

    2013-03-05

    Retrovirus-based vectors are commonly used as delivery vehicles to correct genetic diseases because of their ability to integrate new sequences stably. However, adverse events in which vector integration activates proto-oncogenes, leading to clonal expansion and leukemogenesis hamper their application. The host cell-encoded lens epithelium-derived growth factor (LEDGF/p75) binds lentiviral integrase and targets integration to active transcription units. We demonstrated earlier that replacing the LEDGF/p75 chromatin interaction domain with an alternative DNA-binding protein could retarget integration. Here, we show that transient expression of the chimeric protein using mRNA electroporation efficiently redirects lentiviral vector (LV) integration in wild-type (WT) cells. We then employed this technology in a model for X-linked chronic granulomatous disease (X-CGD) using myelomonocytic PLB-985 gp91(-/-) cells. Following electroporation with mRNA encoding the LEDGF-chimera, the cells were treated with a therapeutic lentivector encoding gp91(phox). Integration site analysis revealed retargeted integration away from genes and towards heterochromatin-binding protein 1β (CBX1)-binding sites, in regions enriched in marks associated with gene silencing. Nevertheless, gp91(phox) expression was stable for at least 6 months after electroporation and NADPH-oxidase activity was restored to normal levels as determined by superoxide production. Together, these data provide proof-of-principle that transient expression of engineered LEDGF-chimera can retarget lentivector integration and rescues the disease phenotype in a cell model, opening perspectives for safer gene therapy.Molecular Therapy - Nucleic Acids (2013) 2, e77; doi:10.1038/mtna.2013.4; published online 5 March 2013.

  16. Solid-State Nuclear Magnetic Resonance Investigation of the Structural Topology and Lipid Interactions of a Viral Fusion Protein Chimera Containing the Fusion Peptide and Transmembrane Domain.

    Science.gov (United States)

    Yao, Hongwei; Lee, Myungwoon; Liao, Shu-Yu; Hong, Mei

    2016-12-13

    The fusion peptide (FP) and transmembrane domain (TMD) of viral fusion proteins play important roles during virus-cell membrane fusion, by inducing membrane curvature and transient dehydration. The structure of the water-soluble ectodomain of viral fusion proteins has been extensively studied crystallographically, but the structures of the FP and TMD bound to phospholipid membranes are not well understood. We recently investigated the conformations and lipid interactions of the separate FP and TMD peptides of parainfluenza virus 5 (PIV5) fusion protein F using solid-state nuclear magnetic resonance. These studies provide structural information about the two domains when they are spatially well separated in the fusion process. To investigate how these two domains are structured relative to each other in the postfusion state, when the ectodomain forms a six-helix bundle that is thought to force the FP and TMD together in the membrane, we have now expressed and purified a chimera of the FP and TMD, connected by a Gly-Lys linker, and measured the chemical shifts and interdomain contacts of the protein in several lipid membranes. The FP-TMD chimera exhibits α-helical chemical shifts in all the membranes examined and does not cause strong curvature of lamellar membranes or membranes with negative spontaneous curvature. These properties differ qualitatively from those of the separate peptides, indicating that the FP and TMD interact with each other in the lipid membrane. However, no (13)C-(13)C cross peaks are observed in two-dimensional correlation spectra, suggesting that the two helices are not tightly associated. These results suggest that the ectodomain six-helix bundle does not propagate into the membrane to the two hydrophobic termini. However, the loosely associated FP and TMD helices are found to generate significant negative Gaussian curvature to membranes that possess spontaneous positive curvature, consistent with the notion that the FP-TMD assembly may

  17. Tamoxifen-regulated adenoviral E1A chimeras for the control of tumor selective oncolytic adenovirus replication in vitro and in vivo.

    Science.gov (United States)

    Sipo, I; Wang, X; Hurtado Picó, A; Suckau, L; Weger, S; Poller, W; Fechner, H

    2006-01-01

    Pharmacological control is a desirable safety feature of oncolytic adenoviruses (oAdV). It has recently been shown that oAdV replication may be controlled by drug-dependent transcriptional regulation of E1A expression. Here, we present a novel concept that relies on tamoxifen-dependent regulation of E1A activity through functional linkage to the mutated hormone-binding domain of the murine estrogen receptor (Mer). Four different E1A-Mer chimeras (ME, EM, E(DeltaNLS)M, MEM) were constructed and inserted into the adenoviral genome under control of a lung-specific surfactant protein B promoter. The highest degree of regulation in vitro was seen for the corresponding oAdVs Ad.E(DeltaNLS)M and Ad.MEM, which exhibited an up to 100-fold higher oAdV replication in the presence as compared with the absence of 4-OH-tamoxifen. Moreover, destruction of nontarget cells was six- and 13-fold reduced for Ad.E(DeltaNLS)M and Ad.MEM, respectively, as compared with Ad.E. Further investigations supported tamoxifen-dependent regulation of Ad.E(DeltaNLS)M and Ad.MEM in vivo. Induction of Ad.E(DeltaNLS)M inhibited growth of H441 lung tumors as efficient as a control oAdV expressing E1A. E(DeltaNLS)M and the MEM chimeras can be easily inserted into a single vector genome, which extends their application to existing oAdVs and strongly facilitates in vivo application.

  18. Primordial germ cell-mediated chimera technology produces viable pure-line Houbara bustard offspring: potential for repopulating an endangered species.

    Directory of Open Access Journals (Sweden)

    Ulrich Wernery

    Full Text Available BACKGROUND: The Houbara bustard (Chlamydotis undulata is a wild seasonal breeding bird populating arid sandy semi-desert habitats in North Africa and the Middle East. Its population has declined drastically during the last two decades and it is classified as vulnerable. Captive breeding programmes have, hitherto, been unsuccessful in reviving population numbers and thus radical technological solutions are essential for the long term survival of this species. The purpose of this study was to investigate the use of primordial germ cell-mediated chimera technology to produce viable Houbara bustard offspring. METHODOLOGY/PRINCIPAL FINDINGS: Embryonic gonadal tissue was dissected from Houbara bustard embryos at eight days post-incubation. Subsequently, Houbara tissue containing gonadal primordial germ cells (gPGCs was injected into White Leghorn chicken (Gallus gallus domesticus embryos, producing 83/138 surviving male chimeric embryos, of which 35 chimeric roosters reached sexual maturity after 5 months. The incorporation and differentiation of Houbara gPGCs in chimeric chicken testis were assessed by PCR with Houbara-specific primers and 31.3% (5/16 gonads collected from the injected chicken embryos showed the presence of donor Houbara cells. A total of 302 semen samples from 34 chimeric roosters were analyzed and eight were confirmed as germline chimeras. Semen samples from these eight roosters were used to artificially inseminate three female Houbara bustards. Subsequently, 45 Houbara eggs were obtained and incubated, two of which were fertile. One egg hatched as a male live born Houbara; the other was female but died before hatching. Genotyping confirmed that the male chick was a pure-line Houbara derived from a chimeric rooster. CONCLUSION: This study demonstrates for the first time that Houbara gPGCs can migrate, differentiate and eventually give rise to functional sperm in the chimeric chicken testis. This approach may provide a promising

  19. Belle II Silicon Vertex Detector

    CERN Document Server

    Mohanty, Gagan B

    2015-01-01

    The Belle II experiment at the SuperKEKB collider in Japan is designed to indirectly probe new physics using approximately 50 times the data recorded by its predecessor. An accurate determination of the decay-point position of subatomic particles such as beauty and charm hadrons as well as a precise measurement of low-momentum charged particles will play a key role in this pursuit. These will be accomplished by a vertex detector, which comprises two layers of pixelated silicon detector and four layers of silicon vertex detector. We describe herein the design, prototyping and construction efforts of the Belle-II silicon vertex detector that is aimed to be commissioned towards the middle of 2017.

  20. Detector Description Framework in LHCb

    CERN Document Server

    Ponce, Sébastien

    2003-01-01

    The Gaudi architecture and framework are designed to provide a common infrastructure and environment for simulation, filtering, reconstruction and analysis applications. In this context, a Detector Description Service was developed in LHCb in order to also provide easy and coherent access to the description of the experimental apparatus. This service centralizes every information about the detector, including geometry, materials, alignment, calibration, structure and controls. From the proof of concept given by the first functional implementation of this service late 2000, the Detector Description Service has grown and has become one of the major components of the LHCb software, shared among all applications, including simulation, reconstruction, analysis and visualization. We describe here the full and functional implementation of the service. We stress the easiness of customization and extension of the detector description by the user, on the seamless integration with condition databases in order to handle ...

  1. Simple dynamic electromagnetic radiation detector

    Science.gov (United States)

    Been, J. F.

    1972-01-01

    Detector monitors gamma dose rate at particular position in a radiation facility where a mixed neutron-gamma environment exists, thus determining reactor power level changes. Device also maps gamma intensity profile across a neutron-gamma beam.

  2. Silicon Drift Detectors for ALICE

    CERN Document Server

    Navach, F; CERN. Geneva

    1992-01-01

    The Silicon Drift Detector (SDD) is a semiconductor, not yet extensively used in HEP experiment, which has an excellent spatial resolution and granularity about comparable to a pixel device requiring a number of readout channels two order of magnitude less.

  3. A Rapid Coliform Detector Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC, in collaboration with Lucigen, proposes a rapid genetic detector for spaceflight water systems to enable real-time detection of E-coli with minimal...

  4. Rapid Multiplex Microbial Detector Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC, in collaboration with Lucigen, proposes a rapid nucleic acid-based detector for spaceflight water systems to enable simultaneous quantification of multiple...

  5. GEM Detector Electric Field Simulation

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    GEM (Gas Electron Multiplier) detectors have been widely employed in the experimental field of high energy physics and nuclear physics. As a successor to drift chambers, GEMs are much easier to fabricate and have a much higher spatial resolution

  6. Microscopic Simulation of Particle Detectors

    CERN Document Server

    Schindler, Heinrich

    Detailed computer simulations are indispensable tools for the development and optimization of modern particle detectors. The interaction of particles with the sensitive medium, giving rise to ionization or excitation of atoms, is stochastic by its nature. The transport of the resulting photons and charge carriers, which eventually generate the observed signal, is also subject to statistical fluctuations. Together with the readout electronics, these processes - which are ultimately governed by the atomic cross-sections for the respective interactions - pose a fundamental limit to the achievable detector performance. Conventional methods for calculating electron drift lines based on macroscopic transport coefficients used to provide an adequate description for traditional gas-based particle detectors such as wire chambers. However, they are not suitable for small-scale devices such as micropattern gas detectors, which have significantly gained importance in recent years. In this thesis, a novel approach, bas...

  7. Detector Fundamentals for Reachback Analysts

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Myers, Steven Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-03

    This presentation is a part of the DHS LSS spectroscopy course and provides an overview of the following concepts: detector system components, intrinsic and absolute efficiency, resolution and linearity, and operational issues and limits.

  8. Electronic detectors for electron microscopy.

    Science.gov (United States)

    Faruqi, A R; McMullan, G

    2011-08-01

    Electron microscopy (EM) is an important tool for high-resolution structure determination in applications ranging from condensed matter to biology. Electronic detectors are now used in most applications in EM as they offer convenience and immediate feedback that is not possible with film or image plates. The earliest forms of electronic detector used routinely in transmission electron microscopy (TEM) were charge coupled devices (CCDs) and for many applications these remain perfectly adequate. There are however applications, such as the study of radiation-sensitive biological samples, where film is still used and improved detectors would be of great value. The emphasis in this review is therefore on detectors for use in such applications. Two of the most promising candidates for improved detection are: monolithic active pixel sensors (MAPS) and hybrid pixel detectors (of which Medipix2 was chosen for this study). From the studies described in this review, a back-thinned MAPS detector appears well suited to replace film in for the study of radiation-sensitive samples at 300 keV, while Medipix2 is suited to use at lower energies and especially in situations with very low count rates. The performance of a detector depends on the energy of electrons to be recorded, which in turn is dependent on the application it is being used for; results are described for a wide range of electron energies ranging from 40 to 300 keV. The basic properties of detectors are discussed in terms of their modulation transfer function (MTF) and detective quantum efficiency (DQE) as a function of spatial frequency.

  9. The SELEX Phototube RICH Detector

    CERN Document Server

    Engelfried, J; Kilmer, J; Kozhevnikov, A P; Kubarovskii, V P; Molchanov, V V; Nemitkin, A V; Ramberg, E; Rud, V I; Stutte, L

    1999-01-01

    In this article, construction, operation, and performance of the RICH detector of Fermilab experiment 781 (SELEX) are described. The detector utilizes a matrix of 2848 phototubes for the photocathode to detect Cherenkov photons generated in a 10m Neon radiator. For the central region an N0 of 104/cm, corresponding to 13.6 hits on a beta=1 ring, was obtained. The ring radius resolution measured is 1.6%.

  10. Repeatability of Harris Corner Detector

    Institute of Scientific and Technical Information of China (English)

    HU Lili

    2003-01-01

    Interest point detectors are commonly employed to reduce the amount of data to be processed. The ideal interest point detector would robustly select those features which are most appropriate or salient for the application and data at hand. This paper shows that interest points are geometrically stable under different transformations.This property makes interest points very successful in the context of image matching. To measure this property quantatively, we introduce a evaluation criterion: repeatability rate.

  11. A Classification Leveraged Object Detector

    OpenAIRE

    Sun, Miao; Han, Tony X.; He, Zhihai

    2016-01-01

    Currently, the state-of-the-art image classification algorithms outperform the best available object detector by a big margin in terms of average precision. We, therefore, propose a simple yet principled approach that allows us to leverage object detection through image classification on supporting regions specified by a preliminary object detector. Using a simple bag-of- words model based image classification algorithm, we leveraged the performance of the deformable model objector from 35.9%...

  12. L3 detector: BGO assembly

    CERN Multimedia

    CERN

    1989-01-01

    Explanation and presentation of its construction ( Feb-March 1989). The detector is a multi-layered cylindrical set of different devices, each of them measuring physical quantities relevant to the reconstruction of the collision under study. The three main outer layers are the electro-magnetic calorimeter (also called BGO because it's made of Bismuth Germanium Oxide), the hadronic calorimeter (HCAL) and the muon detector.

  13. Handheld ultrasound concealed weapons detector

    Science.gov (United States)

    Felber, Franklin S.; Wild, Norbert C.; Nunan, Scott C.; Breuner, Dennis; Doft, Frank

    1998-12-01

    A handheld, battery-operated prototype of a remove concealed weapons detector has been built and tested. The concealed weapons detector will enable law enforcement and security officers to detect metallic and nonmetallic weapons concealed beneath clothing remotely from beyond arm's length to about 20 feet. These detectors may be used to: (1) allow hands-off, stand-off frisking of suspects for metallic and nonmetallic weapons; and (2) search for metallic and nonmetallic weapons on cooperative subjects at courthouse entrances and other monitored security portals. We have demonstrated that we image weapons concealed under heavy clothing, not just detect them, at ranges up to 15 feet using the same ultrasound frequency (40 kHz) used by commercial rangefinders. The concealed weapons detector operates much as a rangefinder, but at higher peak fluxes and pulse repetition frequencies. The detector alerts the user to concealed weapons audibly and visibly by detecting ultrasound glints above a body/clothing baseline, and by compensating for changing range and attenuation. The detector locates concealed weapons within a 6-inch illuminated spot at 10 feet. The signal processor eliminates any signal from behind the target.

  14. DUAL-BAND INFRARED DETECTORS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    As the infrared technology continues to advance, there is a growing demand for multispectral detectors for advanced IR systems with better target discrimination and identification. Both HgCdTe detectors and quantum well GaAs/AlGaAs photodetectors offer wavelength flexibility from medium wavelength to very long wavelength and multicolor capability in these regions. The main challenges facing all multicolor devices are more complicated device structtures, thicker and multilayer material growth, and more difficult device fabrication, especially when the array size gets larger and pixel size gets smaller. In the paper recent progress in development of two-color HgCdTe photodiodes and quantum well infrared photodetectors is presented.More attention is devoted to HgCdTe detectors. The two-color detector arrays are based upon an n-P-N (the capital letters mean the materials with larger bandgap energy) HgCdTe triple layer heterojunction design. Vertically stacking the two p-n junctions permits incorporation of both detectros into a single pixel. Both sequential mode and simultaneous mode detectors are fabricated. The mode of detection is determined by the fabrication process of the multilayer materials.Also the performances of stacked multicolor QWIPs detectors are presented. For multicolor arrays, QWIP's narrow band spectrum is an advantage, resulting in low spectral crosstalk. The major challenge for QWIP is developing broadband or multicolor optical coupling structures that permit efficient absorption of all required spectral bands.

  15. New class of neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Czirr, J.B.

    1997-09-01

    An optimized neutron scattering instrument design must include all significant components, including the detector. For example, useful beam intensity is limited by detector dead time; detector pixel size determines the optimum beam diameter, sample size, and sample to detector distance; and detector efficiency vs. wavelength determines the available energy range. As an example of the next generation of detectors that could affect overall instrumentation design, we will describe a new scintillator material that is potentially superior to currently available scintillators. We have grown and tested several small, single crystal scintillators based upon the general class of cerium-activated lithium lanthanide borates. The outstanding characteristic of these materials is the high scintillation efficiency-as much as five times that of Li-glass scintillators. This increase in light output permits the practical use of the exothermic B (n, alpha) reaction for low energy neutron detection. This reaction provides a four-fold increase in capture cross section relative to the Li (n, alpha) reaction, and the intriguing possibility of demanding a charged-particle/gamma ray coincidence to reduce background detection rates. These new materials will be useful in the thermal and epithermal energy ran at reactors and pulsed neutron sources.

  16. Performance of Ultra-Fast Silicon Detectors

    CERN Document Server

    Cartiglia, N; Ely, S; Fadeyev, V; Galloway, Z; Marchetto, F; Mazza, G; Ngo, J; Obertino, M; Parker, C; Rivetti, A; Shumacher, D; Sadrozinski, H F-W; Seiden, A; Zatserklyaniy, A

    2013-01-01

    The development of Low-Gain Avalanche Detectors has opened up the possibility of manufacturing silicon detectors with signal larger than that of traditional sensors. In this paper we explore the timing performance of Low-Gain Avalanche Detectors, and in particular we demonstrate the possibility of obtaining ultra-fast silicon detector with time resolution of less than 20 picosecond.

  17. Two-dimensional microstrip detector for neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Oed, A. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    Because of their robust design, gas microstrip detectors, which were developed at ILL, can be assembled relatively quickly, provided the prefabricated components are available. At the beginning of 1996, orders were received for the construction of three two-dimensional neutron detectors. These detectors have been completed. The detectors are outlined below. (author). 2 refs.

  18. Methods of selection in heavy ion collisions at Fermi energies and de-excitation modes with the INDRA multi-detector; Methodes de tri dans les collisions d'ions lourds aux energies de Fermi et modes de desexcitation avec le multidetecteur INDRA

    Energy Technology Data Exchange (ETDEWEB)

    Lautesse, Ph

    2005-11-15

    The progress made in particle detection, particularly the design of multi-detectors, like INDRA, that cover a solid angle of almost 4{pi}, have given a new impetus to heavy ion collisions. These detectors are demanding for an efficient way of selecting events that have a common history or similar features, for instance the events representing the de-excitation of a unique emitter. The problem is to find the adequate variable on which the discrimination can be based. Different methods are proposed in this work, the common point is that they require efficient models to reproduce and analyse experimental data in order to apprehend the equation of state of nuclear matter. Most of these models are based on the numerically solving of the nuclear Boltzmann equation. The application to the Ni + Ni reaction with an energy ranging from a few A.MeV to more than 50 A.MeV illustrates this work. (A.C.)

  19. Advanced Space Radiation Detector Technology Development

    Science.gov (United States)

    Wrbanek, John D.; Wrbanek, Susan Y.; Fralick, Gustave C.

    2013-01-01

    The advanced space radiation detector development team at the NASA Glenn Research Center (GRC) has the goal of developing unique, more compact radiation detectors that provide improved real-time data on space radiation. The team has performed studies of different detector designs using a variety of combinations of solid-state detectors, which allow higher sensitivity to radiation in a smaller package and operate at lower voltage than traditional detectors. Integration of multiple solid-state detectors will result in an improved detector system in comparison to existing state-of-the-art instruments for the detection and monitoring of the space radiation field for deep space and aerospace applications.

  20. Progress on CMS detector lowering

    CERN Multimedia

    2006-01-01

    It was an amazing engineering challenge - the lowering of the first hugeendcap disc (YE+3) of the CMS detector slowly and carefully 100 metres underground. The spectacular descent took place on 30 November and was documented by a film crew from Reuters news group. The uniquely shaped slice is 16 m high, about 50 cm thick, and weighs 400 tonnes. It is one of 15 sections that make up the complete CMS detector. The solid steel structure of the disc forms part of the magnet return yoke and is equipped on both sides with muon chambers. A special gantry crane lowered the element, with just 20 cm of leeway between the edges of the detector and the walls of the shaft! On 12 December, a further section of the detector (YE+2) containing the cathode strip chamber made the 10-hour journey underground. This piece is 16 m high and weighs 880 tonnes. There are now four sections of the detector in the experimental cavern, with a further 11 to follow. The endcap disc YE+3 (seen in the foreground) begins its journey down the ...

  1. Portable humanitarian mine detector overview

    Science.gov (United States)

    Allsopp, David J.; Dibsdall, Ian M.

    2002-08-01

    This paper will present an overview and early results of the QinetiQ Portable Humanitarian Mine Detector project, funded by the UK Treasury Capital Modernization Fund. The project aims to develop a prototype multi-sensor man-portable detector for humanitarian demining, drawing on experience from work for UK MoD. The project runs from July 2000 to October 2002. The project team have visited mined areas and worked closely with a number of demining organizations and a manufacturer of metal detectors used in the field. The primary objective is to reduce the number of false alarms resulting from metallic ground clutter. An analysis of such clutter items found during actual demining has shown a large proportion to be very small when compared with anti-personnel mines. The planned system integrates: a lightweight multi-element pseudo-random-code ground penetrating radar array; a pulse induction metal detector and a capacitive sensor. Data from the GPR array and metal detector are fused to provide a simple audio-visual operator interface. The capacitive sensor provides information to aid processing of the radar responses and to provide feedback to the operator of the position of the sensors above the ground. At the time of presentation the project should be in the final stages of build, prior to tests and field trials, which QinetiQ hope to carry out under the International Test and Evaluation Project (ITEP) banner.

  2. High precision thermal neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Radeka, V.; Schaknowski, N.A.; Smith, G.C.; Yu, B. [Brookhaven National Laboratory, Upton, NY (United States)

    1994-12-31

    Two-dimensional position sensitive detectors are indispensable in neutron diffraction experiments for determination of molecular and crystal structures in biology, solid-state physics and polymer chemistry. Some performance characteristics of these detectors are elementary and obvious, such as the position resolution, number of resolution elements, neutron detection efficiency, counting rate and sensitivity to gamma-ray background. High performance detectors are distinguished by more subtle characteristics such as the stability of the response (efficiency) versus position, stability of the recorded neutron positions, dynamic range, blooming or halo effects. While relatively few of them are needed around the world, these high performance devices are sophisticated and fairly complex, their development requires very specialized efforts. In this context, we describe here a program of detector development, based on {sup 3}He filled proportional chambers, which has been underway for some years at the Brookhaven National Laboratory. Fundamental approaches and practical considerations are outlined that have resulted in a series of high performance detectors with the best known position resolution, position stability, uniformity of response and reliability over time, for devices of this type.

  3. Report on Advanced Detector Development

    Energy Technology Data Exchange (ETDEWEB)

    James K. Jewell

    2012-09-01

    Neutron, gamma and charged particle detection improvements are key to supporting many of the foreseen measurements and systems envisioned in the R&D programs and the future fuel cycle requirements, such as basic nuclear physics and data, modeling and simulation, reactor instrumentation, criticality safety, materials management and safeguards. This task will focus on the developmental needs of the FCR&D experimental programs, such as elastic/inelastic scattering, total cross sections and fission neutron spectra measurements, and will leverage a number of existing neutron detector development efforts and programs, such as those at LANL, PNNL, INL, and IAC as well as those at many universities, some of whom are funded under NE grants and contracts. Novel materials and fabrication processes combined with state-of-the-art electronics and computing provide new opportunities for revolutionary detector systems that will be able to meet the high precision needs of the program. This work will be closely coordinated with the Nuclear Data Crosscut. The Advanced Detector Development effort is a broadly-focused activity that supports the development of improved nuclear data measurements and improved detection of nuclear reactions and reactor conditions. This work supports the design and construction of large-scale, multiple component detectors to provide nuclear reaction data of unprecedented quality and precision. Examples include the Time Projection Chamber (TPC) and the DANCE detector at LANL. This work also supports the fabrication and end-user application of novel scintillator materials detection and monitoring.

  4. COMMISSIONING AND DETECTOR PERFORMANCE GROUPS

    CERN Multimedia

    D. Acosta

    The commissioning effort is presently addressing two main areas: the commissioning of the hardware components at the pit and the coordination of the activities of the newly constituted Detector Performance groups (DPGs). At point 5, a plan regarding the service cavern and the commissioning of the connections of the off-detector electronics (for the data collection line and trigger primitive generation) to the central DAQ and the central Trigger has been defined. This activity was started early February and will continue until May. It began with Tracker electronics followed so far by HCAL and CSC. The goal is to have by May every detector commission, as much as possible, their data transfer paths from FED to Central DAQ as well as their trigger setups between TPGs and Global Level 1 trigger. The next focus is on connections of front-ends to the service cavern. This depends strongly on the installations of services. Presently the only detector which has its link fibers connected to the off-detector electr...

  5. Semiconductor X-ray detectors

    CERN Document Server

    Lowe, Barrie Glyn

    2014-01-01

    Identifying and measuring the elemental x-rays released when materials are examined with particles (electrons, protons, alpha particles, etc.) or photons (x-rays and gamma rays) is still considered to be the primary analytical technique for routine and non-destructive materials analysis. The Lithium Drifted Silicon (Si(Li)) X-Ray Detector, with its good resolution and peak to background, pioneered this type of analysis on electron microscopes, x-ray fluorescence instruments, and radioactive source- and accelerator-based excitation systems. Although rapid progress in Silicon Drift Detectors (SDDs), Charge Coupled Devices (CCDs), and Compound Semiconductor Detectors, including renewed interest in alternative materials such as CdZnTe and diamond, has made the Si(Li) X-Ray Detector nearly obsolete, the device serves as a useful benchmark and still is used in special instances where its large, sensitive depth is essential. Semiconductor X-Ray Detectors focuses on the history and development of Si(Li) X-Ray Detect...

  6. Belle II silicon vertex detector

    Science.gov (United States)

    Adamczyk, K.; Aihara, H.; Angelini, C.; Aziz, T.; Babu, V.; Bacher, S.; Bahinipati, S.; Barberio, E.; Baroncelli, Ti.; Baroncelli, To.; Basith, A. K.; Batignani, G.; Bauer, A.; Behera, P. K.; Bergauer, T.; Bettarini, S.; Bhuyan, B.; Bilka, T.; Bosi, F.; Bosisio, L.; Bozek, A.; Buchsteiner, F.; Casarosa, G.; Ceccanti, M.; Červenkov, D.; Chendvankar, S. R.; Dash, N.; Divekar, S. T.; Doležal, Z.; Dutta, D.; Enami, K.; Forti, F.; Friedl, M.; Hara, K.; Higuchi, T.; Horiguchi, T.; Irmler, C.; Ishikawa, A.; Jeon, H. B.; Joo, C. W.; Kandra, J.; Kang, K. H.; Kato, E.; Kawasaki, T.; Kodyš, P.; Kohriki, T.; Koike, S.; Kolwalkar, M. M.; Kvasnička, P.; Lanceri, L.; Lettenbicher, J.; Maki, M.; Mammini, P.; Mayekar, S. N.; Mohanty, G. B.; Mohanty, S.; Morii, T.; Nakamura, K. R.; Natkaniec, Z.; Negishi, K.; Nisar, N. K.; Onuki, Y.; Ostrowicz, W.; Paladino, A.; Paoloni, E.; Park, H.; Pilo, F.; Profeti, A.; Rashevskaya, I.; Rao, K. K.; Rizzo, G.; Rozanska, M.; Sandilya, S.; Sasaki, J.; Sato, N.; Schultschik, S.; Schwanda, C.; Seino, Y.; Shimizu, N.; Stypula, J.; Suzuki, J.; Tanaka, S.; Tanida, K.; Taylor, G. N.; Thalmeier, R.; Thomas, R.; Tsuboyama, T.; Uozumi, S.; Urquijo, P.; Vitale, L.; Volpi, M.; Watanuki, S.; Watson, I. J.; Webb, J.; Wiechczynski, J.; Williams, S.; Würkner, B.; Yamamoto, H.; Yin, H.; Yoshinobu, T.

    2016-09-01

    The Belle II experiment at the SuperKEKB collider in Japan is designed to indirectly probe new physics using approximately 50 times the data recorded by its predecessor. An accurate determination of the decay-point position of subatomic particles such as beauty and charm hadrons as well as a precise measurement of low-momentum charged particles will play a key role in this pursuit. These will be accomplished by an inner tracking device comprising two layers of pixelated silicon detector and four layers of silicon vertex detector based on double-sided microstrip sensors. We describe herein the design, prototyping and construction efforts of the Belle-II silicon vertex detector.

  7. Radiation Hardening of Silicon Detectors

    CERN Multimedia

    Leroy, C; Glaser, M

    2002-01-01

    %RD48 %title\\\\ \\\\Silicon detectors will be widely used in experiments at the CERN Large Hadron Collider where high radiation levels will cause significant bulk damage. In addition to increased leakage current and charge collection losses worsening the signal to noise, the induced radiation damage changes the effective doping concentration and represents the limiting factor to long term operation of silicon detectors. The objectives are to develop radiation hard silicon detectors that can operate beyond the limits of the present devices and that ensure guaranteed operation for the whole lifetime of the LHC experimental programme. Radiation induced defect modelling and experimental results show that the silicon radiation hardness depends on the atomic impurities present in the initial monocrystalline material.\\\\ \\\\ Float zone (FZ) silicon materials with addition of oxygen, carbon, nitrogen, germanium and tin were produced as well as epitaxial silicon materials with epilayers up to 200 $\\mu$m thickness. Their im...

  8. Belle II silicon vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Adamczyk, K. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Aihara, H. [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Angelini, C. [Dipartimento di Fisica, Università di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Aziz, T.; Babu, V. [Tata Institute of Fundamental Research, Mumbai 400005 (India); Bacher, S. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Bahinipati, S. [Indian Institute of Technology Bhubaneswar, Satya Nagar (India); Barberio, E.; Baroncelli, Ti.; Baroncelli, To. [School of Physics, University of Melbourne, Melbourne, Victoria 3010 (Australia); Basith, A.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Batignani, G. [Dipartimento di Fisica, Università di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bauer, A. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Behera, P.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Bergauer, T. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Bettarini, S. [Dipartimento di Fisica, Università di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bhuyan, B. [Indian Institute of Technology Guwahati, Assam 781039 (India); Bilka, T. [Faculty of Mathematics and Physics, Charles University, 121 16 Prague (Czech Republic); Bosi, F. [INFN Sezione di Pisa, I-56127 Pisa (Italy); Bosisio, L. [Dipartimento di Fisica, Università di Trieste, I-34127 Trieste (Italy); INFN Sezione di Trieste, I-34127 Trieste (Italy); and others

    2016-09-21

    The Belle II experiment at the SuperKEKB collider in Japan is designed to indirectly probe new physics using approximately 50 times the data recorded by its predecessor. An accurate determination of the decay-point position of subatomic particles such as beauty and charm hadrons as well as a precise measurement of low-momentum charged particles will play a key role in this pursuit. These will be accomplished by an inner tracking device comprising two layers of pixelated silicon detector and four layers of silicon vertex detector based on double-sided microstrip sensors. We describe herein the design, prototyping and construction efforts of the Belle-II silicon vertex detector.

  9. DRIFT EFFECTS IN HGCDTE DETECTORS

    Directory of Open Access Journals (Sweden)

    B. PAVAN KUMAR

    2013-08-01

    Full Text Available The characteristics of temporal drift in spectral responsivity of HgCdTe photodetectors is investigated and found to have an origin different from what has been reported in literature. Traditionally, the literature attributes the cause of drift due to the deposition of thin film of ice water on the active area of the cold detector. The source of drift as proposed in this paper is more critical owing to the difficulties in acquisition of infrared temperature measurements. A model explaining the drift phenomenon in HgCdTe detectors is described by considering the deep trapping of charge carriers and generation of radiation induced deep trap centers which are meta-stable in nature. A theoretical model is fitted to the experimental data. A comparison of the model with the experimental data shows that the radiation induced deep trap centers and charge trapping effects are mainly responsible for the drift phenomenon observed in HgCdTe detectors.

  10. The ATLAS Detector Control System

    CERN Document Server

    Schlenker, S; Kersten, S; Hirschbuehl, D; Braun, H; Poblaguev, A; Oliveira Damazio, D; Talyshev, A; Zimmermann, S; Franz, S; Gutzwiller, O; Hartert, J; Mindur, B; Tsarouchas, CA; Caforio, D; Sbarra, C; Olszowska, J; Hajduk, Z; Banas, E; Wynne, B; Robichaud-Veronneau, A; Nemecek, S; Thompson, PD; Mandic, I; Deliyergiyev, M; Polini, A; Kovalenko, S; Khomutnikov, V; Filimonov, V; Bindi, M; Stanecka, E; Martin, T; Lantzsch, K; Hoffmann, D; Huber, J; Mountricha, E; Santos, HF; Ribeiro, G; Barillari, T; Habring, J; Arabidze, G; Boterenbrood, H; Hart, R; Marques Vinagre, F; Lafarguette, P; Tartarelli, GF; Nagai, K; D'Auria, S; Chekulaev, S; Phillips, P; Ertel, E; Brenner, R; Leontsinis, S; Mitrevski, J; Grassi, V; Karakostas, K; Iakovidis, G.; Marchese, F; Aielli, G

    2011-01-01

    The ATLAS experiment is one of the multi-purpose experiments at the Large Hadron Collider (LHC), constructed to study elementary particle interactions in collisions of high-energy proton beams. Twelve different sub-detectors as well as the common experimental infrastructure are supervised by the Detector Control System (DCS). The DCS enables equipment supervision of all ATLAS sub-detectors by using a system of >130 server machines running the industrial SCADA product PVSS. This highly distributed system reads, processes and archives of the order of 106 operational parameters. Higher level control system layers allow for automatic control procedures, efficient error recognition and handling, and manage the communication with external systems such as the LHC. This contribution firstly describes the status of the ATLAS DCS and the experience gained during the LHC commissioning and the first physics data taking operation period. Secondly, the future evolution and maintenance constraints for the coming years an...

  11. Fiber optic ionizing radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Suter, J.J. (Johns Hopkins Univ., Applied Physics Lab., Laurel, MD (United States)); Poret, J.C.; Rosen, M. (Johns Hopkins Univ., Dept. of Materials Science and Engineering, Baltimore, MD (United States))

    1992-08-01

    Radiation detection can be done by various types of devices, such as Geiger counters, thermoluminescent detectors, and electric field sensors. This paper reports on a noel design for an ionizing radiation sensor using coiled optical fibers, which can be placed within or near a radioactive source. This design has several features that make it different from sensors proposed in the past. In order to evaluate this sensor, coiled fiber samples were placed inside metallic and metal-matrix composite cylinders to evaluate the sensitivity of the detector as well as the shielding effectiveness of the materials.

  12. Research on particle imaging detectors

    CERN Document Server

    1995-01-01

    Much instrumentation has been developed for imaging the trajectories of elementary particles produced in high energy collisions. Since 1968, gaseous detectors, beginning with multiwire chambers and drift chambers, have been used for the visualisation of particle trajectories and the imaging of X-rays, neutrons, hard gamma rays, beta rays and ultraviolet photons. This book commemorates the groundbreaking research leading to the evolution of such detectors carried out at CERN by Georges Charpak, Nobel Prizewinner for Physics in 1992. Besides collecting his key papers, the book also includes original linking commentary which sets his work in the context of other worldwide research.

  13. CLIC inner detectors cooling simulations

    CERN Document Server

    Duarte Ramos, F.; Villarejo Bermudez, M.

    2014-01-01

    The strict requirements in terms of material budget for the inner region of the CLIC detector concepts require the use of a dry gas for the cooling of the respective sen- sors. This, in conjunction with the compactness of the inner volumes, poses several challenges for the design of a cooling system that is able to fulfil the required detec- tor specifications. This note introduces a detector cooling strategy using dry air as a coolant and shows the results of computational fluid dynamics simulations used to validate the proposed strategy.

  14. Micro-pattern gaseous detectors

    CERN Document Server

    Shekhtman, L I

    2002-01-01

    Introduced at the end of 1980s micro-pattern gas detectors perform much better than classic wire chambers. They allow to achieve both excellent localization accuracy and high rate capability that make this technology attractive for charged particle tracking at high luminosity colliders. During its evolution micro-pattern gas technology gave raise to many different types of devices such as micro-strip gas chambers, MicroMEGAS, CAT and gas electron multipliers. Essential improvements in the performance of the detectors were achieved especially in what concerned long-term performance: aging and resistance to accidental discharges.

  15. New science with new detectors

    Energy Technology Data Exchange (ETDEWEB)

    Graafsma, H.; Grubel, G.; Ryan, A.; Dautet, H.; Longoni, A.; Fiorini, H.; Vacchi, A.; Broennimann, C.; Gruner, S.; Berar, J.F.; Boudet, N.; Clemens, J.C.; Delpierre, P.; Siddons, P.; O' Connor, P.; Geronimo, G. de; Rehak, P.; Ryan, C.; Poulsen, H.F.; Wulff, M.; Lorenc, M.; Kong, Q.; Lo Russo, M.; Cammarata, M.; Reichenbach, W.; Eybert, L.; Claustre, L.; Miao, J.; Ishikawa, T.; Riekel, C.; Monaco, G.; Cloetens, P.; Huotari, S.; Albergamo, F.; Henriquet, C.; Graafsma, H.; Ponchut, C.; Vanko, G.; Verbeni, R.; Mokso, R.; Ludwig, W.; Boller, E.E.; Hignette, O.; Lambert, J.; Bohic, S

    2005-07-01

    The ESRF (European synchrotron radiation facility), with the help of the user community, is in the process of developing its long term strategy, covering the next 10 to 20 years. A central role in this strategy will be given to detector developments, since it is clear that the biggest possible improvement in performance is by increasing the overall detection capabilities. These improvements can be both quantitative, meaning more and larger detectors, and qualitative, meaning new detection concepts. This document gathers the abstracts and transparencies of most presentations of this workshop.

  16. SED Stroop Effect Detector prototype

    OpenAIRE

    Hernández Quesada, Xerach Acorán

    2013-01-01

    [ES] El Detector de Efectos Stroop (SED - Stroop Effect Detector), es una herramienta informática de asistencia, desarrollada a través del programa de investigación de Desarrollo Tecnológico Social de la Universidad de Las Palmas de Gran Canaria, que ayuda a profesionales del sector neuropsicológico a identificar problemas en la corteza orbitofrontal de un individuo, usándose para ello la técnica ideada por Schenker en 1998. Como base metodológica, se han utilizado los conocimientos adquirido...

  17. Recent Developments in Detector Technology

    CERN Document Server

    Brau, James E

    2010-01-01

    This review provides an overview of many recent advances in detector technologies for particle physics experiments. Challenges for new technologies include increasing spatial and temporal sensitivity, speed, and radiation hardness while minimizing power and cost. Applications are directed at several future collider experiments, including the Large Hadron Collider luminosity upgrade (sLHC), the linear collider, and the super high luminosity B factory, as well as neutrino and other fixed target experiments, and direct dark matter searches. Furthermore, particle physics has moved into space, with significant contributions of detector technology, and new challenges for future efforts.

  18. Large volume cryogenic silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Braggio, C. [Dipartimento di Fisica, Universita di Padova, via Marzolo 8, 35131 Padova (Italy); Boscardin, M. [Fondazione Bruno Kessler (FBK), via Sommarive 18, I-38100 Povo (Italy); Bressi, G. [INFN sez. di Pavia, via Bassi 6, 27100 Pavia (Italy); Carugno, G.; Corti, D. [INFN sez. di Padova, via Marzolo 8, 35131 Padova (Italy); Galeazzi, G. [INFN lab. naz. Legnaro, viale dell' Universita 2, 35020 Legnaro (Italy); Zorzi, N. [Fondazione Bruno Kessler (FBK), via Sommarive 18, I-38100 Povo (Italy)

    2009-12-15

    We present preliminary measurements for the development of a large volume silicon detector to detect low energy and low rate energy depositions. The tested detector is a one cm-thick silicon PIN diode with an active volume of 31 cm{sup 3}, cooled to the liquid helium temperature to obtain depletion from thermally-generated free carriers. A thorough study has been done to show that effects of charge trapping during drift disappears at a bias field value of the order of 100V/cm.

  19. Infrared-transparent microstrip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, M. [Instituto de Fisica de Cantabria (IFCA), Ed. Juan Jorda, E-39005 Santander (Spain)], E-mail: Marcos.Fernandez@cern.ch; Duarte, J.; Gonzalez, J.; Heinemeyer, S.; Jaramillo, R.; Lopez, A.; Martinez, C.; Ruiz, A.; Vila, I. [Instituto de Fisica de Cantabria (IFCA), Ed. Juan Jorda, E-39005 Santander (Spain); Cabruja, E.; Lozano, M.; Pellegrini, G. [Centro Nacional de Microelectronica CNM-IMB, Campus Universidad Autonoma Barcelona, 08193 Bellaterra, Barcelona (Spain)

    2009-01-01

    The two main limiting factors in the accuracy of an optomechanical position monitoring system based on laser sources and photosensors are mechanical transfer between the monitored imaging sensors to the active particle tracking elements and non-straight propagation of the reference laser lines. Laser based alignment systems of Si trackers that use their own tracking detectors as photosensors are not affected by the first factor. Improving the transmittance of Si to infrared beams certainly minimizes the second one. Simulation of the passage of a light beam through a real microstrip detector and analysis of first measurements of samples are presented in this paper.

  20. Silicon Detector Letter of Intent

    Energy Technology Data Exchange (ETDEWEB)

    Aihara, H.; Burrows, P.; Oreglia, M.

    2010-05-26

    This document presents the current status of SiD's effort to develop an optimized design for an experiment at the International Linear Collider. It presents detailed discussions of each of SiD's various subsystems, an overview of the full GEANT4 description of SiD, the status of newly developed tracking and calorimeter reconstruction algorithms, studies of subsystem performance based on these tools, results of physics benchmarking analyses, an estimate of the cost of the detector, and an assessment of the detector R&D needed to provide the technical basis for an optimised SiD.

  1. Characterization of liquid scintillation detectors

    CERN Document Server

    Schmidt, D; Böttger, R; Klein, H; Lebreton, L; Neumann, S; Nolte, R; Pichenot, G

    2002-01-01

    Five scintillation detectors of different scintillator size and type were characterized. The pulse height scale was calibrated in terms of electron light output units using photon sources. The response functions for time-of-flight (TOF)-selected monoenergetic neutrons were experimentally determined and also simulated with the NRESP code over a wide energy range. A comparison of the measured and calculated response functions allows individual characteristics of the detectors to be determined and the response matrix to be reliably derived. Various applications are discussed.

  2. Conceptual design studies for a CEPC detector

    Science.gov (United States)

    Chekanov, S. V.; Demarteau, M.

    2016-11-01

    The physics potential of the Circular Electron Positron Collider (CEPC) can be significantly strengthened by two detectors with complementary designs. A promising detector approach based on the Silicon Detector (SiD) designed for the International Linear Collider (ILC) is presented. Several simplifications of this detector for the lower energies expected at the CEPC are proposed. A number of cost optimizations of this detector are illustrated using full detector simulations. We show that the proposed changes will enable one to reach the physics goals at the CEPC.

  3. Tolerance of CD8+ T cells developing in parent-->F1 chimeras prepared with supralethal irradiation: step-wise induction of tolerance in the intrathymic and extrathymic environments.

    Science.gov (United States)

    Kosaka, H; Sprent, J

    1993-02-01

    Tolerance of CD8+ cells was examined in parent-->F1 bone marrow chimeras (BMC) prepared with supralethal irradiation; host class I expression in the chimeras was limited to non-BM-derived cells. In terms of helper-independent proliferative responses in vitro and induction of graft-vs.-host disease on adoptive transfer, CD8+ cells from long-term chimeras showed profound tolerance to host antigens irrespective of whether the cells were prepared from the thymus or from spleen or lymph nodes. By limiting dilution analysis, cytotoxic T lymphocyte (CTL) precursors specific for host antigens were rare in the extrathymic lymphoid tissues. In the thymus, by contrast, host-specific CTL precursors were only slightly less frequent than in normal parental strain mice. These host-specific CD8+ cells survived when BMC thymocytes were transferred intravenously to a neutral environment, i.e., to donor strain mice. When transferred to further BMC hosts, however, most of the host-reactive cells disappeared. Collectively, the data suggest that tolerance of CD8+ cells in BMC hosts occurs in both the intrathymic and extrathymic environments. In the thymus, contact with host antigens on thymic epithelial cells deletes CD8+ cells controlling helper-independent proliferative responses and in vivo effector functions but spares typical helper-dependent CTL precursors. After export from the thymus, most of the CTL precursors are eliminated after contacting host antigens on stromal cells in the extrathymic environment.

  4. Analysis of the cloverleaf element in a human rhinovirus type 14/poliovirus chimera: correlation of subdomain D structure, ternary protein complex formation and virus replication.

    Science.gov (United States)

    Rieder, Elizabeth; Xiang, Wenkai; Paul, Aniko; Wimmer, Eckard

    2003-08-01

    RNA genomes of enteroviruses and rhinoviruses contain a 5'-terminal structure, the cloverleaf (CL), which serves as signal in RNA synthesis. Substitution of the poliovirus [PV1(M)] CL with that of human rhinovirus type 2 (HRV2) was shown previously to produce a viable chimeric PV, whereas substitution with the HRV14 CL produced a null phenotype. Fittingly, the HRV14 CL failed to form a complex with PV-specific proteins 3CD(pro)-3AB or 3CD(pro)-PCBP2, considered essential for RNA synthesis. It was reported previously (Rohll et al., J Virol 68, 4384-4391, 1994) that the major determinant for the null phenotype of a PV/HRV14 chimera resides in subdomain Id of the HRV14 CL. Using a chimeric PV/HRV14 CL in the context of the PV genome, stem-loop Id of HRV14 CL was genetically dissected. It contains the sequence C(57)UAU(60)-G, the underlined nucleotides forming the loop that is shorter by 1 nt when compared to the corresponding PV structure (UUGC(60)GG). Insertion of a G nucleotide to form a tetra loop (C(57)UAU(60)GG(61)) did not rescue replication of the chimera. However, an additional mutation at position 60 (C(57)UAC(60)GG(61)) yielded a replicating genome. Only the mutant PV/HRV14 CL with the UAC(60)G tetra loop formed ternary complexes efficiently with either PV proteins 3CD(pro)-3AB or 3CD(pro)-PCBP2. Thus, in the context of PV RNA synthesis, the presence of a tetra loop in subdomain D of the CL per se is not sufficient for function. The sequence and, consequently, the structure of the tetra loop plays an essential role. Biochemical assays demonstrated that the function of the CL element and the function of the cis-acting replication element in the 3D(pol)-3CD(pro)-dependent uridylylation of VPg are not linked.

  5. Acute serum amyloid A induces migration, angiogenesis, and inflammation in synovial cells in vitro and in a human rheumatoid arthritis/SCID mouse chimera model.

    LENUS (Irish Health Repository)

    Connolly, Mary

    2010-06-01

    Serum amyloid A (A-SAA), an acute-phase protein with cytokine-like properties, is expressed at sites of inflammation. This study investigated the effects of A-SAA on chemokine-regulated migration and angiogenesis using rheumatoid arthritis (RA) cells and whole-tissue explants in vitro, ex vivo, and in vivo. A-SAA levels were measured by real-time PCR and ELISA. IL-8 and MCP-1 expression was examined in RA synovial fibroblasts, human microvascular endothelial cells, and RA synovial explants by ELISA. Neutrophil transendothelial cell migration, cell adhesion, invasion, and migration were examined using transwell leukocyte\\/monocyte migration assays, invasion assays, and adhesion assays with or without anti-MCP-1\\/anti-IL-8. NF-kappaB was examined using a specific inhibitor and Western blotting. An RA synovial\\/SCID mouse chimera model was used to examine the effects of A-SAA on cell migration, proliferation, and angiogenesis in vivo. High expression of A-SAA was demonstrated in RA patients (p < 0.05). A-SAA induced chemokine expression in a time- and dose-dependent manner (p < 0.05). Blockade with anti-scavenger receptor class B member 1 and lipoxin A4 (A-SAA receptors) significantly reduced chemokine expression in RA synovial tissue explants (p < 0.05). A-SAA induced cell invasion, neutrophil-transendothelial cell migration, monocyte migration, and adhesion (all p < 0.05), effects that were blocked by anti-IL-8 or anti-MCP-1. A-SAA-induced chemokine expression was mediated through NF-kappaB in RA explants (p < 0.05). Finally, in the RA synovial\\/SCID mouse chimera model, we demonstrated for the first time in vivo that A-SAA directly induces monocyte migration from the murine circulation into RA synovial grafts, synovial cell proliferation, and angiogenesis (p < 0.05). A-SAA promotes cell migrational mechanisms and angiogenesis critical to RA pathogenesis.

  6. COMMISSIONING AND DETECTOR PERFORMANCE GROUPS

    CERN Multimedia

    T. Camporesi

    The major progress made during the last months has been in the consolidation of services for the +endcaps and three barrel wheels (YB+2, YB+1 and YB0): all subdetectors have now final power connections (including Detector Safety protection), the gas systems have been commissioned for all gas detectors (the recirculation is not yet activated for the RPC though) and detector cooling has also been commissioned. Their integration with final services is the necessary condition for being able to operate larger fractions the detector. Recent weeks have seen full HCAL, more than 50% of EB and full wheels of DTs and CSC being operated using final services. This has not yet translated into major progress of global integration due to major interruptions of central services, which have not allowed the necessary debugging and commissioning time to all the subdetec¬tors and central activities like DAQ and trigger. Moreover the running in of the final central services has introduced instabilities related to the co...

  7. View of the ALEPH detector

    CERN Multimedia

    1996-01-01

    The inner workings of the ALEPH detector on the LEP accelerator can be seen. Cranes and hydraulics are located around the experimental cavern so that these sections can be accessed for upgrades and maintenance. The LEP accelerator and its four experiments studied high-energy collisions between electrons and positrons from 1989 to 2000.

  8. Physics and Detectors at CLIC

    CERN Document Server

    CERN. Geneva

    2012-01-01

    CLIC represents an attractive option for the future particle physics programme at the energy frontier. CLIC is a proposed electron-positron linear collider, based on a novel two beam accelerating structure, with the capability of operating at centre-of-mass energies of up to 3 TeV. The Physics and Detector volume of the CLIC conceptual design report was recently published as a CERN yellow report. In this seminar, I will review the conclusions of this report, focussing on four main areas. Firstly, I will give an overview of the physics potential at CLIC, and will place this in the context of a possible scenario for the staged construction of the machine. Secondly, I will discuss the challenges for a detector operating in the CLIC machine environment. I will then present detailed studies of possible detector concepts, based on high granularity particle flow calorimetry, which demonstrate that the required detector performance goals at CLIC can be met. Finally, I will highlight the main issues for the future R&a...

  9. Neutron transmutation doped silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.; Krejner, Kh.; Ito, D.; Khusimi, K.; Okava, S.; Sirejsi, F.

    1984-01-01

    A method of doping neutron transmutation during (NTD) of Si crystals is described. Characteristics of detectors made of crystals obtained by the NTD method at low and room temperatures are measured. The possibility is studied of using the NTD method to produce Si crystals with a longer lifetime of non-base charge carriers, high specific resistance and more even distribution of specific resistance over the detector radius. The NTD method is based on /sup 30/Si isotope transmutation into /sup 31/Si following the (n, ..gamma..)-reaction. The /sup 31/Si isotope is unstable and transforms to /sup 31/P while emitting ..beta../sup -/. The NTD method consists in introduction of purified gaseous monosilan SiH/sub 4/ into the furnace to undergo thermal decomposition at 860 deg C with the formation of polycrystalline n-type Si. The polycrystalline Si prepared is treated mechanically and, after purification by the method of a ''floating zone'' in vacuum and in argon irradiated by a thermal neutron flux with the a density of 5x10/sup 11/ neUtr/(cm/sup 2/ x s) for 30-75 min. An analysis of the data obtained shows that the specifications of the Si detectors prepared by the NTD method are the same as those of conventional Si-detectors widely used nowadays but their cost of production is considerably lower.

  10. The ATLAS Detector Safety System

    CERN Multimedia

    Helfried Burckhart; Kathy Pommes; Heidi Sandaker

    The ATLAS Detector Safety System (DSS) has the mandate to put the detector in a safe state in case an abnormal situation arises which could be potentially dangerous for the detector. It covers the CERN alarm severity levels 1 and 2, which address serious risks for the equipment. The highest level 3, which also includes danger for persons, is the responsibility of the CERN-wide system CSAM, which always triggers an intervention by the CERN fire brigade. DSS works independently from and hence complements the Detector Control System, which is the tool to operate the experiment. The DSS is organized in a Front- End (FE), which fulfills autonomously the safety functions and a Back-End (BE) for interaction and configuration. The overall layout is shown in the picture below. ATLAS DSS configuration The FE implementation is based on a redundant Programmable Logical Crate (PLC) system which is used also in industry for such safety applications. Each of the two PLCs alone, one located underground and one at the s...

  11. Handheld Concealed Weapons Detector Development

    Science.gov (United States)

    2003-03-01

    Enforcement, Edward M. Carapezza, Donald Spector, Eds., Proc. SPIE 2938, 110 - 119 (1997). 3. Franklin Felber, Norbert Wild, Scott Nunan , Dennis Breuner... Nunan , D. Breuner, and F. Doft, "Handheld Ultrasound Concealed-Weapons Detector," in Enforcement and Security Technologies, A. Trent DePersia, J. J

  12. Largest particle detector nearing completion

    CERN Multimedia

    2006-01-01

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

  13. The ALICE pixel detector upgrade

    Science.gov (United States)

    Reidt, F.

    2016-12-01

    The ALICE experiment at the CERN LHC is designed to study the physics of strongly interacting matter, and in particular the properties of the Quark-Gluon Plasma, using proton-proton, proton-nucleus and nucleus-nucleus collisions. The ALICE collaboration is preparing a major upgrade of the experimental apparatus to be installed during the second long LHC shutdown in the years 2019-2020. A key element of the ALICE upgrade is the new, ultra-light, high-resolution Inner Tracking System. With respect to the current detector, the new Inner Tracking System will significantly enhance the pointing resolution, the tracking efficiency at low transverse momenta, and the read-out rate capabilities. This will be obtained by seven concentric detector layers based on a Monolithic Active Pixel Sensor with a pixel pitch of about 30×30 μm2. A key feature of the new Inner Tracking System, which is optimised for high tracking accuracy at low transverse momenta, is the very low mass of the three innermost layers, which feature a material budget of 0.3% X0 per layer. This contribution presents the design goals and layout of the upgraded ALICE Inner Tracking System, summarises the R&D activities focussing on the technical implementation of the main detector components, and the projected detector performance.

  14. Sputtered film thermistor IR detectors

    Science.gov (United States)

    Baliga, Shankar B.; Rost, Martin R.; Doctor, Alan P.

    1994-07-01

    The thermistor infrared detector or bolometer is the detector of choice in many classical remote sensing applications such as horizon sensing, noncontact thermometry, and industrial applications. In recent years, the authors have developed a thin film process where the thermistor material is deposited from a target directly onto the substrate. This is an advance over the labor intensive ceramic technology, where sintered flakes of the thermistor are bonded to the substrate. The thin film technique permits a variety of device constructions and configurations. Detectors fabricated on heat-sunk ceramic substrates can withstand high operating temperatures and large incident optical power, in both pulsed and CW laser measurements. For dc or low frequency measurements, the films can be deposited onto a thermally isolated membrane with applications in motion sensing, gas detection, and temperature measurement. Utilizing advances in micromachining a 2D array of thermally isolated microbolometer sensors, integrated onto a silicon wafer containing readout circuitry may be achieved. This paper describes the construction of the sputtered film thermistor detectors, their operation, and applications.

  15. High performance visual display for HENP detectors

    CERN Document Server

    McGuigan, M; Spiletic, J; Fine, V; Nevski, P

    2001-01-01

    A high end visual display for High Energy Nuclear Physics (HENP) detectors is necessary because of the sheer size and complexity of the detector. For BNL this display will be of special interest because of STAR and ATLAS. To load, rotate, query, and debug simulation code with a modern detector simply takes too long even on a powerful work station. To visualize the HENP detectors with maximal performance we have developed software with the following characteristics. We develop a visual display of HENP detectors on BNL multiprocessor visualization server at multiple level of detail. We work with general and generic detector framework consistent with ROOT, GAUDI etc, to avoid conflicting with the many graphic development groups associated with specific detectors like STAR and ATLAS. We develop advanced OpenGL features such as transparency and polarized stereoscopy. We enable collaborative viewing of detector and events by directly running the analysis in BNL stereoscopic theatre. We construct enhanced interactiv...

  16. Efficient scalable solid-state neutron detector

    Science.gov (United States)

    Moses, Daniel

    2015-06-01

    We report on scalable solid-state neutron detector system that is specifically designed to yield high thermal neutron detection sensitivity. The basic detector unit in this system is made of a 6Li foil coupled to two crystalline silicon diodes. The theoretical intrinsic efficiency of a detector-unit is 23.8% and that of detector element comprising a stack of five detector-units is 60%. Based on the measured performance of this detector-unit, the performance of a detector system comprising a planar array of detector elements, scaled to encompass effective area of 0.43 m2, is estimated to yield the minimum absolute efficiency required of radiological portal monitors used in homeland security.

  17. Silicon Pixel Detectors for Synchrotron Applications

    CERN Document Server

    Stewart, Graeme Douglas

    Recent advances in particle accelerators have increased the demands being placed on detectors. Novel detector designs are being implemented in many different areas including, for example, high luminosity experiments at the LHC or at next generation synchrotrons. The purpose of this thesis was to characterise some of these novel detectors. The first of the new detector types is called a 3D detector. This design was first proposed by Parker, Kenney and Segal (1997). In this design, doped electrodes are created that extend through the silicon substrate. When compared to a traditional photodiode with electrodes on the opposing surfaces, the 3D design can combine a reasonable detector thickness with a small electrode spacing resulting in fast charge collection and limited charge sharing. The small electrode spacing leads to the detectors having lower depletion voltages. This, combined with the fast collection time, makes 3D detectors a candidate for radiation hard applications. These applications include the upgra...

  18. Study Performance of Liquid Scintillation Fiber Detector

    CERN Document Server

    Zhang, Yongpeng; Lu, Haoqi; Zhang, Peng; Zhang, Chengcai; Yang, Changgen

    2016-01-01

    Liquid scintillator (LS) with optical fiber detector (LSOF detector) is a new type of detector, which has been applied in large-scale particle physics experiments in recent years. We were proposing LSOF detector as one option of top veto detector in Jiangmen Underground Neutrino Observatory (JUNO) experiment. The prototype detector was located in laboratory of the institute of high energy physics (IHEP). From prototype study, we found that the detector have a good performance and can satisfy JUNO requirement. The detection efficiency of cosmic ray muon is greater than 98% and can collect 58 photon electrons (p.e.) when muon is going through the detector. Further more, the relationship between p.e., material reflectivity and LS depth are studied. We also compared the data with Monte Carlo simulation, and they have a good agreement with each other.

  19. Responsivity Calibration of Pyroelectric Terahertz Detectors

    CERN Document Server

    Berry, Christopher W; Jarrahi, Mona

    2014-01-01

    There has been a significant advancement in terahertz radiation sources in the past decade, making milliwatt terahertz power levels accessible in both continuous-wave and pulsed operation. Such high-power terahertz radiation sources circumvent the need for cryogenic-cooled terahertz detectors such as semiconductor bolometers and necessitate the need for new types of calibrated, room-temperature terahertz detectors. Among various types of room-temperature terahertz detectors, pyroelectric detectors are one of the most widely used detectors, which can offer wide dynamic range, broad detection bandwidth, and high sensitivity levels. In this article, we describe the calibration process of a commercially available pyroelectric detector (Spectrum Detector, Inc, SPI-A-65 THz), which incorporates a 5 mm diameter LiTaO3 detector with an organic terahertz absorber coating.

  20. Sistema detector d'incendis WSN

    OpenAIRE

    Domínguez López, Emiliano

    2012-01-01

    Sistema detector d'incendis aprofitant una xarxa de sensors sense fils (WSN) mitjançant un sistema encastat. Sistema detector de incendios aprovechando una red de sensores inalámbricos (WSN) mediante un sistema empotrado.