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Sample records for alpha-nucleus interaction potential

  1. Nucleus-nucleus potential with repulsive core and elastic scattering. Part 1. Nucleus-nucleus interaction potential

    International Nuclear Information System (INIS)

    Davidovs'ka, O.Yi.; Denisov, V.Yu.; Nesterov, V.O.

    2010-01-01

    Various approaches for nucleus-nucleus interaction potential evaluation are discussed in details. It is shown that the antisymmetrization of nucleons belonging to different nuclei and the Pauli principle give the essential contribution into the nucleus-nucleus potential at distances, when nuclei are strongly overlapping, and lead to appearance of the repulsive core of nucleus nucleus interaction at small distances between nuclei.

  2. Diabatic interaction potential for nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Noerenberg, W.; Lukasiak, A.

    1984-01-01

    Within a refined method for the construction of diabatic states allowing for the treatment of the full spin-orbit coupling, characteristic features of the diabatic potential for nucleus-nucleus collisions are investigated. Approximately 90% of the strong repulsion results from diabatic particle-hole excitations, while only 10% is due to compression. The diabatic interaction potential describes a physical situation intermediate between adiabatic and sudden approximations. (orig.)

  3. Nucleus--nucleus potential

    International Nuclear Information System (INIS)

    Jaqaman, H.R.

    1977-01-01

    The nucleus--nucleus interaction is studied within the framework of the generator coordinate method that permits an easy incorporation of the full effects of antisymmetrization. It is found that the interaction, as far as the elastic scattering problem is concerned, can be described by a simple effective potential that is equivalent to the original many-body (and hence non-local) problem. The potential is obtained by dividing the wavefunction into a long-range part and a short-range part and requiring the former to satisfy a Schroedinger equation. This enables avoiding dealing with the troublesome short-range part of the wavefunction and provides a direct link with the optical model so that the potential obtained here is equivalent to the real part of the optical potential (the imaginary part is not investigated). The effective potential is found to consist of three parts: an interaction term between the nucleons belonging to different nuclei, a kinetic energy term due to the change in the intrinsic kinetic energy of the system as a result of the antisymmetrization, and finally an l-dependent part. The kinetic energy term is found to be very repulsive and effectively gives a hard core, and is calculated for the α--α and 16 O-- 16 O cases. The full potential is calculated for the α--α case for the S, D, and G partial waves and then used to calculate the corresponding phase shifts that are then compared with experimental results and other microscopic calculations. Finally, some recent results and analyses of fusion and deep inelastic reactions are reviewed that seem to indicate the presence of a hard core in the nucleus--nucleus potential. Such a hard core is present in the potential obtained in the sudden approximation

  4. Study of various models of nuclear interaction potentials: nucleon-nucleus and nucleus-nucleus systems

    International Nuclear Information System (INIS)

    Ngo, H.

    1984-01-01

    Several models, performed within a mean field theory, are developed for the calculation of nucleon-nucleus interaction potentials. The first part of the thesis deals with the nucleon-nucleus average interaction. It is mainly devoted to the calculation of dynamical corrections to the Hartree-Fock approximation. Two approaches are used: a microscopic model performed in the framework of the nuclear structure approach and a semi-phenomenological one, based on the application of the dispersion relations to the empirical imaginary potential. Both models take into account finite size effects like collectivity or threshold effects which are important at low energy. The Green's function properties are used for both models. The second part of this work is devoted to the interaction potential between two heavy ions. This calculation, which is performed in the framework of the sudden approximation, uses the energy density formalism (Thomas-Fermi approximation). It has been extended to finite temperature. At T=0 the experimental fusion barriers of heavy systems are reproduced within 4%. Their temperature dependence is studied. The proximity scaling is checked and a universal function is obtained at T=0 and at finite temperature. It is found that the proximity theorem is well satisfied on the average. The dispersion around the mean behaviour increases with increasing temperature. At last, P+A* and α+A* interaction potentials are calculated within a double folding model using a schematic effective interaction [fr

  5. Effective nucleus-nucleus potentials derived from the generator coordinate method

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, H; Canto, L F [Oxford Univ. (UK). Dept. of Theoretical Physics

    1977-11-07

    The equivalence of the generator coordinate method (GCM) and the resonating group method (RGM) and the formal equivalence of the RGM and the orthogonality condition model (OCM) lead to a relation connecting the effective nucleus-nucleus potentials of the OCM with matrix elements of the GCM. This relation may be used to derive effective nucleus-nucleus potentials directly from GCM matrix elements without explicit reference to the potentials of the RGM. In a first application local and l-independent effective potentials are derived from diagonal GCM matrix elements which represent the energy surfaces of a two-centre shell model. Using these potentials the OCM can reproduce the results of a full RGM calculation very well for the elastic scattering of two ..cap alpha..-particles and fairly well for elastic /sup 16/O-/sup 16/O scattering.

  6. Perimovement decrease of alpha/beta oscillations in the human nucleus accumbens.

    Science.gov (United States)

    Stenner, Max-Philipp; Dürschmid, Stefan; Rutledge, Robb B; Zaehle, Tino; Schmitt, Friedhelm C; Kaufmann, Jörn; Voges, Jürgen; Heinze, Hans-Jochen; Dolan, Raymond J; Schoenfeld, Mircea Ariel

    2016-10-01

    The human nucleus accumbens is thought to play an important role in guiding future action selection via an evaluation of current action outcomes. Here we provide electrophysiological evidence for a more direct, i.e., online, role during action preparation. We recorded local field potentials from the nucleus accumbens in patients with epilepsy undergoing surgery for deep brain stimulation. We found a consistent decrease in the power of alpha/beta oscillations (10-30 Hz) before and around the time of movements. This perimovement alpha/beta desynchronization was observed in seven of eight patients and was present both before instructed movements in a serial reaction time task as well as before self-paced, deliberate choices in a decision making task. A similar beta decrease over sensorimotor cortex and in the subthalamic nucleus has been directly related to movement preparation and execution. Our results support the idea of a direct role of the human nucleus accumbens in action preparation and execution. Copyright © 2016 the American Physiological Society.

  7. Meson-nucleus potentials and the search for meson-nucleus bound states

    Science.gov (United States)

    Metag, V.; Nanova, M.; Paryev, E. Ya.

    2017-11-01

    Recent experiments studying the meson-nucleus interaction to extract meson-nucleus potentials are reviewed. The real part of the potentials quantifies whether the interaction is attractive or repulsive while the imaginary part describes the meson absorption in nuclei. The review is focused on mesons which are sufficiently long-lived to potentially form meson-nucleus quasi-bound states. The presentation is confined to meson production off nuclei in photon-, pion-, proton-, and light-ion induced reactions and heavy-ion collisions at energies near the production threshold. Tools to extract the potential parameters are presented. In most cases, the real part of the potential is determined by comparing measured meson momentum distributions or excitation functions with collision model or transport model calculations. The imaginary part is extracted from transparency ratio measurements. Results on K+ ,K0 ,K- , η ,η‧ , ω, and ϕ mesons are presented and compared with theoretical predictions. The interaction of K+ and K0 mesons with nuclei is found to be weakly repulsive, while the K- , η ,η‧ , ω and ϕ meson-nucleus potentials are attractive, however, with widely different strengths. Because of meson absorption in the nuclear medium the imaginary parts of the meson-nucleus potentials are all negative, again with a large spread. An outlook on planned experiments in the charm sector is given. In view of the determined potential parameters, the criteria and chances for experimentally observing meson-nucleus quasi-bound states are discussed. The most promising candidates appear to be the η and η‧ mesons.

  8. Kaonic nuclei and kaon-nucleus interactions

    CERN Document Server

    Ikuta, K; Masutani, K

    2002-01-01

    Although kaonic atoms provide valuable information concerning the K sup - -nucleus interaction at low energies, they cannot fully determine the K sup - - nucleus optical potential. We demonstrate that K sup - nuclear bound states, if they exist, can be useful in investigating the K sup - -nucleus interaction, especially in the interior of the nucleus. In order to show this possibility, we calculate the double differential cross sections for (K sup - , P) using the Green function method. (author)

  9. Producing a compound Nucleus via Inelastic Scattering: The 90Zr(alpha,alpha')90Zr* Case

    Energy Technology Data Exchange (ETDEWEB)

    Escher, J E; Dietrich, F S

    2008-05-23

    In a Surrogate reaction a compound nucleus is produced via a direct reaction (pickup, stripping, or inelastic scattering). For a proper application of the Surrogate approach it is necessary to predict the resulting angular momentum and parity distribution in the compound nucleus. A model for determining these distributions is developed for the case of inelastic alpha scattering off a spherical nucleus. The focus is on obtaining a first, simple description of the direct-reaction process that produces the compound nucleus and on providing the basis for a more complete treatment of the problem. The approximations employed in the present description are discussed and the extensions required for a more rigorous treatment of the problem are outlined. To illustrate the formalism, an application to {sup 90}Zr({alpha},{alpha}{prime}){sup 90}Zr* is presented.

  10. Some experimental results of the investigation of hadron-nucleus and nucleus-nucleus interactions

    International Nuclear Information System (INIS)

    Azimov, S.A.; Gulamov, K.G.; Chernov, G.M.

    1978-01-01

    Recent experimental data on the hadron-nucleus and nucleus-nucleus inelastic interactions are analyzed. A particular attention is paid to the description of the leading hadron spectra and of the spectra of nucleon recoils in hadron-nucleus interactions. Some of the results of the experimental studies of correlations between secondary particles are discussed. This discussion demonstrates that an analysis of the multiparticle phenomena is very promising regarding the discrimination between the different models for the hadron-nucleus and nucleus-nucleus interactions. It is pointed out that the actual mechanism of the hadron-nucleus and nucleus-nucleus interactions is a rather complex one and can be described comprehensively by none of the existing models

  11. Angular momentum and incident-energy dependence of nucleus-nucleus interaction

    International Nuclear Information System (INIS)

    Yamaguchi, S.

    1991-01-01

    The purpose of this paper is to understand intuitively the origin of the angular momentum and incident-energy dependence of the nucleus-nucleus interaction on the basis of the totally- antisymmetrized many-body theory. With the aim of understanding the structure of the nucleus-nucleus interaction, we show first that the nucleus-nucleus interaction can be written by the use of the density-distribution function and the phase-space distribution function instead of using the many-body wave function itself. And we show that the structure change of the density-distribution function with the increase of the angular momentum causes the angular momentum dependence of the nucleus-nucleus interaction and that the incident-energy dependence of the nucleus-nucleus interaction originates from the structure change of the phase-space distribution function

  12. K+-nucleus interaction

    International Nuclear Information System (INIS)

    Gibbs, W.R.

    1984-01-01

    The K + -nucleus system is reviewed and comparison with data is made. The principal conclusions are that the theoretical uncertainties in relating the K + -nucleus interaction to the K + -nucleon interaction are very small and hence the positive kaon makes an excellent probe of the nucleus. It is suggested that this particle may be more sensitive to non-nucleonic degrees of freedom (especially quarks) than classical probes

  13. Interacting gluon model for hadron-nucleus and nucleus-nucleus collisions in the central rapidity region

    International Nuclear Information System (INIS)

    Fowler, G.N.; Navarra, F.S.; Plumer, M.; Lawrence Berkeley Laboratory, Nuclear Science Division, Berkeley, California 94720); Vourdas, A.; Weiner, R.M.

    1989-01-01

    The interacting gluon model developed to describe the inelasticity distribution in hadron-nucleon collisions has been generalized and applied to hadron-nucleus and nucleus-nucleus interactions. Leading particle spectra and energy distributions in hadron-nucleus and nucleus-nucleus collisions are calculated

  14. Specific interaction of capsid protein and importin-{alpha}/{beta} influences West Nile virus production

    Energy Technology Data Exchange (ETDEWEB)

    Bhuvanakantham, Raghavan; Chong, Mun-Keat [Flavivirology Laboratory, Department of Microbiology, 5 Science Drive 2, National University of Singapore, Singapore 117597 (Singapore); Ng, Mah-Lee, E-mail: micngml@nus.edu.sg [Flavivirology Laboratory, Department of Microbiology, 5 Science Drive 2, National University of Singapore, Singapore 117597 (Singapore)

    2009-11-06

    West Nile virus (WNV) capsid (C) protein has been shown to enter the nucleus of infected cells. However, the mechanism by which C protein enters the nucleus is unknown. In this study, we have unveiled for the first time that nuclear transport of WNV and Dengue virus C protein is mediated by their direct association with importin-{alpha}. This interplay is mediated by the consensus sequences of bipartite nuclear localization signal located between amino acid residues 85-101 together with amino acid residues 42 and 43 of C protein. Elucidation of biological significance of importin-{alpha}/C protein interaction demonstrated that the binding efficiency of this association influenced the nuclear entry of C protein and virus production. Collectively, this study illustrated the molecular mechanism by which the C protein of arthropod-borne flavivirus enters the nucleus and showed the importance of importin-{alpha}/C protein interaction in the context of flavivirus life-cycle.

  15. Nuclear structure approach to the calculation of the imaginary alpha-nucleus optical potential

    International Nuclear Information System (INIS)

    Dermawan, H.; Osterfeld, F.; Madsen, V.A.

    1981-01-01

    A microscopic calculation of the second-order imaginary optical potential for 40 (Ca(α,α) is made for incident energies of 31 and 100 MeV using RPA transition densities for intermediate excited states. The projectile is treated as an elementary particle, and the alpha-nucleon interaction is normalized by fitting 3 - inelastic cross sections with a folded M3Y potential. The use of an optical Green's function for the intermediate propagator is found to be important. Equivalent local potentials are obtained and used to calculate elastic scattering cross sections. Agreement with low-angle experimental data is fair at 31 MeV, but at 100 MeV the calculated cross sections indicate much too little absorption. 9 figures, 1 table

  16. /sup 58,60,62/Ni (. cap alpha. ,p) three--nucleon transfer reactions and. cap alpha. optical potential ambiguities

    Energy Technology Data Exchange (ETDEWEB)

    Yuanda, Wang; Xiuming, Bao; Zhiqiang, Mao; Rongfang, Yuan; Keling, Wen; Binyin, Huang; Zhifu, Wang; Shuming, Li; Jianan, Wang; Zuxun, Sun; others, and

    1985-11-01

    The differential cross sections are measured using 26.0 MeV ..cap alpha.. particle for /sup 58,62/Ni(..cap alpha.., ..cap alpha..) /sup 58,62/Ni and /sup 58,62/Ni(..cap alpha..,p) /sup 61,65/Cu reactions as well as 25.4 MeV ..cap alpha.. particle for /sup 60/Ni(..cap alpha.., ..cap alpha..)/sup 69/Ni and /sup 60/Ni(..cap alpha.., p)/sup 63/Cu reactions. Consistent calculations with optical model and ZR DWBA are made for (..cap alpha.., ..cap alpha..) and (..cap alpha.., p) reactions by using of single, two, three and four nucleon optical potential parameters. For elastic scattering due to the ..cap alpha.. optical potential ambiguities, all the above optical potential can reproduce the experimental angular distributions. However, the single, two and three nucleon potential, including the Baird's mass systematics and the Chang's energy systematics of ..cap alpha.. potentials, obviously can not provide a reasonable fitting with the (..cap alpha..,p) reaction experimental data. Only the results from the four nucleon potential is in good agreement with the (..cap alpha..,p) reaction experimental data. This reveals that in the ..cap alpha..-particle induced transfer reactions, the real depth of the ..cap alpha..-nucleus optical potential should be rather deep.

  17. Muonic atom-light nucleus interaction

    International Nuclear Information System (INIS)

    Kuz'michev, V.E.; Peresypkin, V.V.; Efetov, A.V.

    1991-01-01

    The effective potential of the interaction between light nucleus and two-particle atom at distances greater than its Bohr radius is obtained in the analytic form on the basis of a correct account of three Coulomb particle problem. Features of the interaction between p, t, 4 He, 7 Be nuclei and mesonic atoms μp, μt, μ 4 He and μ 7 Be, that arising from the differences in masses and charges of interacting particles, are studied. The corresponding potentials in the pre-threshold energy range are given. The coefficients of the symptotic formula for the effective are calculated in adiabatic approximation and with regard for the main off-shell corrections. 16 refs.; 4 figs

  18. A survey of the alpha-nucleon interaction

    International Nuclear Information System (INIS)

    Ali, S.; Ahmad, A.A.Z.; Ferdous, N.

    1984-10-01

    A survey of the alpha-nucleon interaction is made. The experimental work on angular distributions of differential scattering cross-sections and polarizations in proton-alpha and neutron-alpha scattering is described. The phenomenological approach which includes the study of both local and non-local potentials reproducing the experimental alpha-nucleon scattering data, is discussed. Basic studies of the alpha-nucleon interaction attempting to build an interaction between an alpha particle and a nucleon from first principles are then described. A critical discussion of the results with some concluding remarks suggesting the direction for further investigation is made. (author)

  19. Coulomb effects in the deuteron-nucleus interaction

    International Nuclear Information System (INIS)

    Kuz'michev, V.E.; Peresypkin, V.V.

    1990-01-01

    The authors develop a consistent theory for calculation of the potential of the deuteron interaction with the Coulomb field of a nucleus. They study the properties of this potential at large distances and give its explicit form at the deuteron-breakup threshold. In the limit of low energies they derive the potential, which includes intermediate off-energy-shell states, and explain the physical nature of its constants. The accuracy of the transition to the polarization interaction is estimated

  20. The imaginary part of the nucleus - nucleus optical potential

    International Nuclear Information System (INIS)

    Phatak, S.C.; Sinha, B.

    1978-01-01

    The contribution to the imaginary nucleus - nucleus optical potential has been estimated by evaluating the energy - conserving seocond-order term in the perturbation series. The incoming nuclear field is supposed to excite nucleons in a nucleus in this calculation and the nuclear excitations are approximated by particle-hole excitations in a Fermi gas. The resulting imaginary potential compares favourably with phenomenological potentials. (author)

  1. Cytological organization of the alpha component of the anterior olfactory nucleus and olfactory limbus

    Directory of Open Access Journals (Sweden)

    Jorge A Larriva-Sahd

    2012-06-01

    Full Text Available This study describes the microscopic organization of a wedge-shaped area at the intersection of the main and accessory olfactory bulbs, or olfactory limbus , and an additional component of the anterior olfactory nucleus or alpha accessory olfactory bulb that lies underneath of the accessory olfactory bulb. The olfactory limbus consists of a modified bulbar cortex bounded anteriorly by the main olfactory bulb and posteriorly by the accessory olfactory bulb. In Nissl-stained specimens the olfactory limbus differs from the main olfactory bulb by a progressive, antero-posterior decrease in thickness or absence of the external plexiform, mitral/tufted cell, and granule cell layers. On cytoarchitectual grounds the olfactory limbus is divided from rostral to caudal into three distinct components: a stripe of glomerular-free cortex or preolfactory area, a second or necklace glomerular area, and a wedge-shaped or interstitial area crowned by the so-called modified glomeruli that appear to belong to the anterior accessory olfactory bulb. The strategic location and interactions with the main and accessory olfactory bulbs, together with the previously noted functional and connectional evidence, suggest that the olfactory limbus may be related to both sensory modalities. The alpha component of the anterior olfactory nucleus, a slender cellular cluster (i.e., 650 x 150 µm paralleling the base of the accessory olfactory bulb, contains two neuron types: a pyramidal-like neuron and an interneuron. Dendrites of pyramidal-like cells organize into a single bundle that ascends avoiding the accessory olfactory bulb to resolve in a trigone bounded by the edge of the olfactory limbus, the accessory olfactory bulb and the dorsal part of the anterior olfactory nucleus. Utrastructurally, the neuropil of the alpha component contains three types of synaptic terminals; one of them immunoreactive to the enzyme glutamate decarboxylase, isoform 67.

  2. Photoproduction of lepton pairs in proton-nucleus and nucleus-nucleus collisions at RHIC and LHC energies

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, B. D.; Goncalves, V. P.; De Santana Amaral, J. T. [Universidade Federal de Pelotas, Instituto de Fisica e Matematica (Brazil)

    2013-03-25

    In this contribution we study coherent interactions as a probe of the nonlinear effects in the Quantum Electrodynamics (QED). In particular, we study the multiphoton effects in the production of leptons pairs for proton-nucleus and nucleus-nucleus collisions for heavy nuclei. In the proton-nucleus we assume the ultrarelativistic proton as a source of photons and estimate the photoproduction of lepton pairs on nuclei at RHIC and LHC energies considering the multiphoton effects associated to multiple rescattering of the projectile photon on the proton of the nucleus. In nucleus - nucleus colllisions we consider the two nuclei as a source of photons. As each scattering contributes with a factor {alpha}Z to the cross section, this contribution must be taken into account for heavy nuclei. We consider the Coulomb corrections to calculate themultiple scatterings and estimate the total cross section for muon and tau pair production in proton-nucleus and nucleus-nucleus collisions at RHIC and LHC energies.

  3. Effective number of inelastically interacting nucleons in rare nucleus-nucleus production processes

    International Nuclear Information System (INIS)

    Korotkikh, V.L.; Lokhtin, I.P.

    1992-01-01

    A model of nucleus-nucleus interaction using one inelastic NN-interaction is suggested for the exclusive production processes with small cross-section. A-dependence nuclear coherent and incoherent production cross-section are predicted. 20 refs.; 4 figs

  4. Final State Interactions Effects in Neutrino-Nucleus Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Golan, Tomasz [Univ. of Wroctaw (Poland); Juszczak, Cezary [Univ. of Wroctaw (Poland); Sobczyk, Jan T. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

    2012-07-01

    Final State Interactions effects are discussed in the context of Monte Carlo simulations of neutrino-nucleus interactions. A role of Formation Time is explained and several models describing this effect are compared. Various observables which are sensitive to FSI effects are reviewed including pion-nucleus interaction and hadron yields in backward hemisphere. NuWro Monte Carlo neutrino event generator is described and its ability to understand neutral current $\\pi^0$ production data in $\\sim 1$ GeV neutrino flux experiments is demonstrated.

  5. Dynamical chaos in a linear 3. alpha. system. Dinamicheskij khaos v linejnoj 3. alpha. -sisteme

    Energy Technology Data Exchange (ETDEWEB)

    Bolotin, Yu L; Gonchar, V Yu; Chekanov, N A [AN Ukrainskoj SSR, Kharkov (Ukrainian SSR). Fiziko-Tekhnicheskij Inst.; Vinitskij, S I [Joint Inst. for Nuclear Research, Dubna (USSR)

    1989-01-01

    Classical dynamics of the motion of a molecular model of the carbon nucleus, which is a linear 3{alpha} system with realistic {alpha}{alpha} interaction is studied. Transition from a regular to a chaos motion in the nuclear molecule is shown to occur with growing energy more rapidly than in model problems with polynomial potentials. It is found that in a small region of the phase space the motion remains regular at energies higher than the 3{alpha}-system dissociation threshold. This is probably related to the C{sub 3v}-symmetry violation. Formulas for the quasiclassical spectrum of the 3{alpha} system are obtained with the use of the Birkhoff normal form.

  6. Antiproton-nucleus interaction

    International Nuclear Information System (INIS)

    Gibbs, W.R.

    1984-01-01

    Several facets of antinucleon-nucleus interactions are explored. The topics treated are: coherent interactions, production of unusual states and particles in the nuclear medium, and the creation of extreme states of matter by antimatter annihilation. It is found that temperatures of the magnitude necessary to achieve the predicted quark-gluon phase transition are obtained. 20 references

  7. The nuclear response and the imaginary potential for nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Phatak, S.C.; Sinha, B.

    1983-01-01

    The Fermi-gas model is used in this paper to study the nucleus-nucleus collision. The field produced by one of the nuclei is considered to act on nucleons in the other nucleus, which is treated as a Fermi gas of radius R. The imaginary part of the (non-local) nucleus-nucleus potential is then computed by evaluating the energy-conserving second-order term in which the intermediate states are particle-hole excitations produced in the Fermi gas. The equivalent local potential, obtained by using the Perey-Saxon method, is compared with phenomenological imaginary potentials. Later it is shown that, in the limit of small range of non-locality, the imaginary potential can be related to the nuclear response function. With this, one can write the nuclear friction coefficient that is used in phenomenological analyses of heavy-ion collisions in terms of the imaginary potential. (orig.)

  8. Nucleus-nucleus interactions in the transition energy regime

    International Nuclear Information System (INIS)

    Volant, C.

    1985-02-01

    There are at least two ways for studying large interactions in nucleus-nucleus collisions. One way is to use the method of angular correlations between fission fragments. The aim of the experiments presented here was to make a survey on the role of the various experimental parameters. In that respect three targets have been studied and different projectiles and bombarding energies have been used. Results are presented and discussed

  9. Contribution to the study of alpha-alpha interaction; Contribution a l'etude de l'interaction alpha - alpha

    Energy Technology Data Exchange (ETDEWEB)

    Darriulai, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-03-01

    Two sets of measurements of the {alpha}-{alpha} elastic scattering differential cross section are presented. The first set - angular distributions from 50 up to 120 MeV - shows two new resonances, 6{sup +} and 8{sup +}, at 25 and 57 MeV. Complex phase shifts are extracted from the data and a phenomenological potential is given. A description of the 3 {alpha}-particle 0{sup +} states in C{sup 12} is made with this interaction potential. The second set - excitation curves between 20 and 50 MeV - allows investigation of the Be{sup 8} level structure within this energy range - It identifies the 16.6 and 16.9 MeV states as 2{sup +}, but the rise of inelastic processes at higher energies makes further identification of spins and parities more and more difficult. (author) [French] Deux series de mesures de la section efficace differentielle de diffusion {alpha}-{alpha} sont presentees. La premiere - distributions angulaires entre 50 et 120 MeV - fait apparaitre deux nouvelles resonances, 6{sup +} et 8{sup +}, a 25 et 57 MeV d'excitation. Des dephasages complexes en sont extraits et un potentiel phenomenologique est presente. Une etude des etats 0{sup +} a parentage (3{alpha}) de {sup 12}C est faite a partir de ce potentiel. La seconde - courbes d'excitation s'etendant de 20 a 50 MeV - met en evidence la structure de {sup 8}Be dans cette region. Elle montre que les niveaux a 16,6 et 16,9 MeV sont des 2{sup +} mais l'importance des processus inelastiques rend difficile l'identification des niveaux d'excitation plus elevee. (auteur)

  10. Dimuon enhancement in nucleus-nucleus ultrarelativistic interactions

    International Nuclear Information System (INIS)

    Bordalo, Paula; Abreu, M.C.; Alessandro, B.; Alexa, C.; Arnaldi, R.; Astruc, J.; Atayan, M.; Baglin, C.; Baldit, A.; Bedjidian, M.; Bellaiche, F.; Beole, S.; Bohrani, A.; Boldea, V.; Bussiere, A.; Capelli, L.; Caponi, V.; Casagrande, L.; Castor, J.; Chambon, T.; Chaurand, B.; Chevrot, I.; Cheynis, B.; Chiavassa, E.; Cicalo, C.; Comets, M.P.; Constans, N.; Constantinescu, S.; Contardo, D.; Cruz, J.; De Falco, A.; De Marco, N.; Dellacasa, G.; Devaux, A.; Dita, S.; Drapier, O.; Ducroux, L.; Espagnon, B.; Fargeix, J.; Ferreira, R.; Filippov, S.N.; Fleuret, F.; Force, P.; Gallio, M.; Gavrilov, Y.K.; Gerschel, C.; Giubellino, P.; Golubeva, M.B.; Gonin, M.; Gorodetzky, P.; Grigorian, A.A.; Grossiord, J.Y.; Guber, F.F.; Guichard, A.; Gulkanyan, H.; Hakobyan, R.; Haroutunian, R.; Idzik, M.; Jouan, D.; Karavitcheva, T.L.; Kluberg, L.; Kossakowski, R.; Kurepin, A.B.; Landau, G.; Le Bornec, Y.; Lourenco, C.; Luquin, L.; Macciotta, P.; Mac Cormick, M.; Mandry, R.; Marzari-Chiesa, A.; Masera, M.; Masoni, A.; Mehrabyan, S.; Monteno, M.; Mourgues, S.; Musso, A.; Ohlsson-Malek, F.; Petiau, P.; Piccotti, A.; Pizzi, J.R.; Prado da Silva, W.L.; Puddu, G.; Quintans, C.; Racca, C.; Ramello, L.; Ramos, S.; Rato-Mendes, P.; Riccati, L.; Romana, A.; Ropotar, I.; Saturnini, P.; Scomparin, E.; Serci, S.; Shahoyan, R.; Silva, S.; Sitta, M.; Soave, C.; Sonderegger, P.; Tarrago, X.; Topilskaya, N.S.; Usai, G.L.; Varela, J.; Vercellin, E.; Villatte, L.

    1999-01-01

    The study of muon pairs in the mass region 1.5 μμ 2 in 450 GeV/c p-A, 200 GeV/nucleon S-U and 158 GeV/nucleon Pb-Pb collisions is presented. In p-A interactions, the dimuon signal mass spectra are well described by a superposition of Drell-Yan and charmed meson semi-leptonic decay contributions, in agreement with previous experiments when considering a linear A dependence. In nucleus-nucleus reactions, taking only into account these two physical ingredients, a dimuon enhancement both with increasing A·B and centrality is observed

  11. The application of a phenomenological model to inelastic nucleus-nucleus interactions for laboratory momenta below 5 GeV/c per nucleon of the incident nucleus

    International Nuclear Information System (INIS)

    Grishin, V.G.; Kladnitskaya, E.N.

    1985-01-01

    A phenomenological model for inelastic nucleus-nucleus interactions at momenta below 5 GeV/c per nucleon is described. Particle interactions inside the interacting nuclei are described by phenomenological models of hadron-nucleus and hadron-nucleon interactions. The Monte-Carlo model provides the kinematic variables for a set of events under study. The comparison of the model inclusive distri-- butions for different particles and nucleus-nucleus interactions agrees well with the experimental data

  12. Quantitative analysis of the fusion cross sections using different microscopic nucleus-nucleus interactions

    Energy Technology Data Exchange (ETDEWEB)

    Adel, A. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Majmaah University, Physics Department, College of Science, Al-Zulfi (Saudi Arabia); Alharbi, T. [Majmaah University, Physics Department, College of Science, Al-Zulfi (Saudi Arabia)

    2017-01-15

    The fusion cross sections for reactions involving medium and heavy nucleus-nucleus systems are investigated near and above the Coulomb barrier using the one-dimensional barrier penetration model. The microscopic nuclear interaction potential is computed by four methods, namely: the double-folding model based on a realistic density-dependent M3Y NN interaction with a finite-range exchange part, the Skyrme energy density functional in the semiclassical extended Thomas-Fermi approximation, the generalized Proximity potential, and the Akyuez-Winther interaction. The comparison between the calculated and the measured values of the fusion excitation functions indicates that the calculations of the DFM give quite satisfactory agreement with the experimental data, being much better than the other methods. New parameterized forms for the fusion barrier heights and positions are presented. Furthermore, the effects of deformation and orientation degrees of freedom on the distribution of the Coulomb barrier characteristics as well as the fusion cross sections are studied for the reactions {sup 16}O + {sup 70}Ge and {sup 28}Si + {sup 100}Mo. The calculated values of the total fusion cross sections are compared with coupled channel calculations using the code CCFULL and compared with the experimental data. Our results reveal that the inclusion of deformations and orientation degrees of freedom improves the comparison with the experimental data. (orig.)

  13. The tree-alpha Faddeev calculation on 12C bound states with a Pauli correct alpha-alpha potential

    International Nuclear Information System (INIS)

    Kamada, Hiroyuki; Oryu, Shinsho

    1986-01-01

    The three-alpha model of 12 C is investigated by the Faddeev formalism with the UIM alpha-alpha potential, in which the Pauli effect between two-alpha system was taken into account adequately. The potential can reproduce the on- and off-shell effects of the alpha-alpha interaction by the rank-4 separable type for the S-wave, the rank-3 one for the D-wave, and the rank-2 one for the G-wave, in which two of the ranks in the S-wave, and one in the D-wave are prepared to eliminate the Pauli forbidden states. We obtained three even states J π = 0 + , 2 + , 4 + , and two odd states 1 - , 3 - , below the alpha- 8 Be(0 + g.s) threshold energy. The even parity states gain larger binding energies than those which have been obtained by former Faddeev calculation with the rank-1 Kukulin and Neudatchin (KN) potential. On the other hand, for the odd parity states, we obtained smaller binding energies than the former one. It is found that our Faddeev calculation with the UIM potential does not miss any important low-lying levels of 12 C, in which any spurious states do not appear. (author)

  14. Four-body problem for four bound alpha particles in 16O

    International Nuclear Information System (INIS)

    Osman, A.

    1980-02-01

    The alpha cluster model is used in considering the 16 O nucleus as a bound state of four alpha particles. This problem is represented by integral equations which are exact effective two-particle equations. These equations have the form of two-particle Lippmann-Schwinger equations. The separable expressions are used in approximating the scattering amplitudes in the separable potential model to include also few and small non-separable rest parts of the interactions. The integral equations obtained are manageable and suitable for computations. Numerical calculations are carried out for the 16 O nucleus, with the structure of four bound alpha particles. The obtained binding energy of 16 O with that structure is 16.86 MeV which is in good agreement with the experimental value. (author)

  15. Description of inelastic nucleus-nucleus interactions at medium energy using dual parton model

    International Nuclear Information System (INIS)

    Polanski, A.; Shmakov, S.Yu.; Uzhinskij, V.V.

    1989-01-01

    It is shown that the dual parton model taking into account the processes of diffraction dissociation to the low mass states and finite energy corrections to the asymptotic Abramovski-Gribov-Kancheli cutting rules allows satisfactory description of existing experimental data on hadron-nucleus and nucleus-nucleus interactions at medium energy. (orig.)

  16. Anti p-nucleus interaction

    International Nuclear Information System (INIS)

    Peng, J.C.

    1986-05-01

    Status and future prospects of antiproton-nucleus scattering experiments are presented. These scattering experiments were conducted at antiproton beam momentums of 300 and 600 MeV/c on target nuclei of 6 Li, 12 C, 16 O, 18 O, 40 Ca, 48 Ca, and 208 Pb. Antiproton-proton reactions investigated antiproton-nucleus bound or resonant states in antiproton reactions with d, 6 Li, 12 C, 63 Cu, and 209 Bi. Inelastic scattering experiments investigated the spin-isospin dependence of the NN interactions. 19 refs., 1 fig., 1 tab

  17. Hadron-nucleus interactions in the nucleon resonance region

    Energy Technology Data Exchange (ETDEWEB)

    Gessler, Stefanie

    2017-06-15

    Experiments with high-energy hadron beams have found renewed attention. In the near future nuclear studies with hadron beams are planned at least at two facilities, namely J-PARC in Japan and GSI/FAIR. The aim of this work is an exploratory investigation of interactions of mesons and baryons with nuclei at energies of interest for future research with antiprotons at FAIR. The theoretical discussion is started with an introductory presentation of the optical model and Eikonal theory as appropriate tools for the description of scattering processes at high energies. In antiproton interactions with nucleons and nuclei, annihilation processes into pions are playing the major role for the reaction dynamics. Therefore, we consider first the interactions of pions with nuclei by deriving an extended selfenergy scheme for a large range of incident pion energies. In order to have a uniform description over a broad energy interval, the existing approaches had to be reconsidered and in essential parts reformulated and extended. A central result is the treatment of pion-nucleus self-energies from high lying N{sup *} resonances. Only by including those channels in a proper manner into the extended pion optical potential, pion-nucleus scattering could be described over the required large energy range. At low energies the well known Kisslinger potential is recapped. Next, the same type of reaction theory is used to analyze antiproton-nucleon and nucleus scattering from low to highly relativistic energies. The reaction dynamics of antiproton interactions with nuclear targets is discussed. We start with a new approach to antiproton-nucleon scattering. A free-space antiproton-nucleon T-matrix is derived, covering an energy range as wide as from 100 MeV up to 15 GeV. Eikonal theory is used to describe the antiproton scattering amplitudes in momentum and in coordinate space. We consider, in particular, interactions with nuclei at energies around and well above 1 GeV. The antiproton-nucleus

  18. Hadron-nucleus interactions in the nucleon resonance region

    International Nuclear Information System (INIS)

    Gessler, Stefanie

    2017-06-01

    Experiments with high-energy hadron beams have found renewed attention. In the near future nuclear studies with hadron beams are planned at least at two facilities, namely J-PARC in Japan and GSI/FAIR. The aim of this work is an exploratory investigation of interactions of mesons and baryons with nuclei at energies of interest for future research with antiprotons at FAIR. The theoretical discussion is started with an introductory presentation of the optical model and Eikonal theory as appropriate tools for the description of scattering processes at high energies. In antiproton interactions with nucleons and nuclei, annihilation processes into pions are playing the major role for the reaction dynamics. Therefore, we consider first the interactions of pions with nuclei by deriving an extended selfenergy scheme for a large range of incident pion energies. In order to have a uniform description over a broad energy interval, the existing approaches had to be reconsidered and in essential parts reformulated and extended. A central result is the treatment of pion-nucleus self-energies from high lying N * resonances. Only by including those channels in a proper manner into the extended pion optical potential, pion-nucleus scattering could be described over the required large energy range. At low energies the well known Kisslinger potential is recapped. Next, the same type of reaction theory is used to analyze antiproton-nucleon and nucleus scattering from low to highly relativistic energies. The reaction dynamics of antiproton interactions with nuclear targets is discussed. We start with a new approach to antiproton-nucleon scattering. A free-space antiproton-nucleon T-matrix is derived, covering an energy range as wide as from 100 MeV up to 15 GeV. Eikonal theory is used to describe the antiproton scattering amplitudes in momentum and in coordinate space. We consider, in particular, interactions with nuclei at energies around and well above 1 GeV. The antiproton-nucleus

  19. Study of η-nucleus interaction through the formation of η-nucleus ...

    Indian Academy of Sciences (India)

    Answer to this question will deeply enrich our understanding of -nucleus interaction which is not so well-understood. We review the experimental efforts for the search of -mesic nuclei and describe the physics motivation behind it. We present the description of an experiment for the search of -nucleus bound state using ...

  20. Analyses of Alpha-Alpha Elastic Scattering Data in the Energy Range 140 - 280 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Shehadeh, Zuhair F. [Taif University, Taif (Saudi Arabia)

    2017-01-15

    The differential and the reaction cross-sections for 4He-4He elastic scattering data have been nicely obtained at four energies ranging from 140 MeV to 280 MeV (lab system), namely, 140, 160, 198 and 280 MeV, by using a new optical potential with a short-range repulsive core. The treatment has been handled relativistically as υ/c > 0.25 for the two lower energies and υ/c > 0.31 for the two higher ones. In addition to explaining the elastic angular distributions, the adopted potentials accounted for the structure that may exist at angles close to 90◦ , especially for the 198 and the 280-MeV incident energies. No renormalization has been used, and all our potential parameters are new. The necessity of including a short-range repulsive potential term in our real nuclear potential part has been demonstrated. Our results contribute to solving a long-standing problem concerning the nature of the alpha-alpha potential. This is very beneficial in explaining unknown alpha-nucleus and nucleus-nucleus relativistic reactions by using the cluster formalism.

  1. Percolation Model of Nuclear Multifragmentation in High Energy Nucleus-Nucleus Interactions

    International Nuclear Information System (INIS)

    Abdel-Waged, Kh.

    1994-01-01

    A hybrid model based on Reggeon theory inspired model of nuclear distribution, which was successful in explaining the cascading of particles in high energy nucleus-nucleus interactions, and percolation model is proposed. In the framework of this model the yield of the fragment in p + Ag, Au at 350 GeV and C + Ag, Au at 3.6 GeV/nucleon as well as the charge distribution of fragments in Kr, Xe and U interactions with emulsion at ∼ 1 GeV/nucleon is correctly described. 32 refs., 3 figs

  2. Problems of the π meson-nucleus interaction theory

    International Nuclear Information System (INIS)

    Kopaleishvili, T.I.

    1984-01-01

    The theory of multiple scattering as applied to PI-meson scattering on nuclei is outlined on the base of optical potential method: first in neglecting the real absorption of a pion by a nucleus and then for the case when this effect is taken into account. The pion interaction with a deuteron is considered both neglecting the pion absorption channel (the relativisitic problem of three bodies) and with account of the absorption channels and pion emission (in this case the problem is solved within the frames of the channel coupling theory for the pion-two nucleus system and the system of two nucleons). Approximate or model solutions to the problem of elastic pion-nuclear scattering primarily in the range of (3.3)-resonance are presented. The formulated theory permits to uniquely describe the observed processes caused by the strong pion interaction with a two-nucleon system

  3. A variational calculation of 12C in the alpha-particle model

    International Nuclear Information System (INIS)

    Portilho, O.

    1973-01-01

    Some physical properties of three structureless alpha particles interacting through two-body potentials were discussed. Comparison between them and the corresponding experimental observations for the 12 C nucleus is done. The wave function is expanded in terms of translationally invariant harmonic-oscillator states, the coefficients being variational parameters

  4. The average number of alpha-particle hits to the cell nucleus required to eradicate a tumour cell population

    International Nuclear Information System (INIS)

    Roeske, John C; Stinchcomb, Thomas G

    2006-01-01

    Alpha-particle emitters are currently being considered for the treatment of micrometastatic disease. Based on in vitro studies, it has been speculated that only a few alpha-particle hits to the cell nucleus are considered lethal. However, such estimates do not consider the stochastic variations in the number of alpha-particle hits, energy deposited, or in the cell survival process itself. Using a tumour control probability (TCP) model for alpha-particle emitters, we derive an estimate of the average number of hits to the cell nucleus required to provide a high probability of eradicating a tumour cell population. In simulation studies, our results demonstrate that the average number of hits required to achieve a 90% TCP for 10 4 clonogenic cells ranges from 18 to 108. Those cells that have large cell nuclei, high radiosensitivities and alpha-particle emissions occurring primarily in the nuclei tended to require more hits. As the clinical implementation of alpha-particle emitters is considered, this type of analysis may be useful in interpreting clinical results and in designing treatment strategies to achieve a favourable therapeutic outcome. (note)

  5. Estimation of nuclear destruction in high energy nucleus-nucleus interactions

    International Nuclear Information System (INIS)

    Uzhinskij, V.V.

    1995-01-01

    It is assumed that: 1) a projectile particle invokes into target nucleus a cascade of quark-gluon exchanges; 2) the nucleons involved in the cascade are ejected from the nucleus which leads to the nuclear destruction. On these bases a simple model to estimate the nuclear destruction at the fast stage of the interaction is proposed. The allowed region of the model parameters is determined at the proton-emulsion high-energy interaction data analysis: an analysis of gold interactions with nuclei at an energy of 600 MeV/nucleon fixes the parameter values. The distributions on the energy in zero degree calorimeter (T ZDC ) in the interactions of Si+Al, Cu, Pb (14 GeV/nucleon) and Au+Au (10 GeV/nucleon) calculated in the framework of the model and in the cascade-evaporation model (CEM) are presented. The proposed model describes the nuclear destruction at intermediate and high energies better than CEM does. The estimation of the average values of impact parameter and the number of intra-nuclear collisions for Au+Au interactions in the events with different T ZDC is given. 34 refs., 11 figs

  6. Hadron-nucleus interactions with a small target-nucleus excitation

    International Nuclear Information System (INIS)

    Anzon, Z.V.; Chasnikov, I.Ya.; Shakhova, Ts.I.

    1981-01-01

    Hadron inelastic interactions in nuclear emulsion with a small target-nucleus excitation in the energy range 7.5-200 GeV have been studied. Possible reasons for the differences in production cross-section for events with even and odd number of S-particles are analysed

  7. Invariant potential for elastic pion--nucleus scattering

    International Nuclear Information System (INIS)

    Cammarata, J.B.; Banerjee, M.K.

    1976-01-01

    From the Wick-Dyson expansion of the exact propagator of a pion in the presence of a nucleus, an invariant potential for crossing symmetric elastic pion-nucleus scattering is obtained in terms of a series of pion-nucleon diagrams. The Chew-Low theory is used to develop a model in which the most important class of diagrams is effectively summed. Included in this model is the exclusion principle restriction on the pion-bound nucleon interaction, the effects of the binding of nucleons, a kinematic transformation of energy from the lab to the πN center of mass frame, and the Fermi motion and recoil of the target nucleons. From a numerical study of the effects of these processes on the π- 12 C total cross section, the relative importance of each is determined. Other processes contributing to the elastic scattering of pions not included in the present model are also discussed

  8. Survival of alpha particle irradiated cells as a function of the shape and size of the sensitive volume (nucleus)

    International Nuclear Information System (INIS)

    Stinchcomb, T.G.; Roeske, J.C.

    1995-01-01

    Microdosimetry is the study of the stochastic variation of energy deposited within sub-cellular targets. As such, the size and shape of the critical target (i.e. cell nucleus) are essential when considering microdosimetric quantities. In this work, a microdosimetric analysis examines the expected cell survival as a function of the size and shape of the cell nucleus under conditions of irradiation emitting alpha particles. The results indicate that, in general, cell survival is relatively insensitive to changes in the shape of the cell nucleus when the volume is held constant. However, cell survival is a strong function of the variation in the size of the target. These results are useful when analysing the results of cell survival experiments for alpha particle emitters. (Author)

  9. Double folding model of nucleus-nucleus potential: formulae, iteration method and computer code

    International Nuclear Information System (INIS)

    Luk'yanov, K.V.

    2008-01-01

    Method of construction of the nucleus-nucleus double folding potential is described. Iteration procedure for the corresponding integral equation is presented. Computer code and numerical results are presented

  10. Dirac phenomenology and hyperon-nucleus interactions

    Energy Technology Data Exchange (ETDEWEB)

    Mares, J; Jennings, B K [TRIUMF, Vancouver, British Columbia (Canada); Cooper, E D [Fraser Valley Univ. College, Chilliwack, British Columbia (Canada). Dept. of Physics

    1993-05-01

    We discuss various aspects of hyperon-nucleus interactions in the relativistic mean field theory. First, characteristics of {Lambda}, {Sigma} and {identical_to} hypernuclei, as well as multi strange baryonic objects, are investigated. The spin-orbit splittings and magnetic moments are shown to be very sensitive to the value of the tensor coupling f{omega}y. Second, optical potentials for {Lambda} and {Sigma} scattering off nuclei are developed based on a global nucleon-nucleon Dirac optical potential and SU(3) symmetry. The tensor coupling has a large effect on the predictions for the analyzing power. Third, the Dirac approach is used in the calculations of the non-mesonic decay of {Lambda} hypernuclei. The large discrepancy between the decay rates and data suggests the need for additional meson exchanges. (authors). 62 refs.,7 figs., 6 tabs.

  11. Calculation of subLAMBDA sup 9 Be in an alpha-alpha-LAMBDA three-body model using the Faddeev equations

    CERN Document Server

    Oryu, S; Yamashita, H; Nakazawa, M; Kamada, H

    2000-01-01

    The hypernucleus subLAMBDA sup 9 Be is investigated in an alpha-alpha-LAMBDA three-body model using the Faddeev formalism. We use an alpha-alpha interaction in which the Pauli-forbidden states are correctly taken into account and we employ some phenomenological potentials between the alpha and LAMBDA particles. We obtained two bound states for J suppi = 1/2 sup + and 3/2 sup + , and three resonance states of (3/2) sub 1 sup - , (3/2) sub 2 sup - , (3/2) sub 3 sup -. We studied the properties of these states by calculating the components and the expectation values of the potential for each partial wave. It is found that a few channels dominate in the 1/2 sup + and 3/2 sup + states, so that the alpha-clusters or the sup 8 Be core are still alive in the nucleus. In a case were the two alpha particles are fixed on an axis the contour plots of the distribution of the LAMBDA particle are shown. With the assistence of these plots one can visually understand that some of them are shell-model-like states while others ...

  12. Calculations of nucleus-nucleus microscopic optical potentials at intermediate energies

    International Nuclear Information System (INIS)

    Hanna, K.M.; Kuhtina, I.N.; Lukyanov, K.V.; Lukyanov, V.K.; Zemlyanaya, E.V.; Slowinski, B.

    2006-01-01

    Three types of microscopic nucleus-nucleus optical potentials are constructed using three patterns for their real and imaginary parts. Two of these patterns are the real V H and imaginary W H parts of the potential which reproduces the high-energy amplitude of scattering in the microscopic Glauber-Sitenko theory. Another template VDF is calculated within the standard double-folding model with the exchange term included. For either of the three tested potentials, the contribution of real and imaginary patterns is adjusted by introducing two fitted factors. Correspondingly, using numerical code ECIS, the elastic differential cross-sections were fitted to the experimental data on scattering of the 16,17 O heavy-ions at about hundred Mev/nucleon on various target-nuclei. The relativization effect is also included. The tables of the obtained factors which renormalize the strengths of the real and (or) imaginary parts of the calculated microscopic potentials are given

  13. Pion, pion-pion, and pion-nucleus interactions

    CERN Document Server

    Mukhin, K N; Tikhonov, V N

    2002-01-01

    This survey is devoted to describing the early studies of 1.1. Gurevich on pion physics that were performed by the photoemulsion method and the studies of the pion-pion interaction that were made by his colleagues on the basis of the hydrogen-bubble-chamber and the magnetic-spectrometer method (as well-as on the basis of the photoemulsion method). Two approaches-an extrapolation of experimental data from the physical region to the pion pole and a theoretical calculation based on the Roy integral equations-are used to deduce information about the pion-pion interaction. The first results obtained for pion-pion and pion-nucleus interactions in the experiments that are being currently performed in Brookhaven and at CERN ( pi pi interaction) and at TRIUMF (Canada) and in Brookhaven (pion-nucleus interaction) are presented, along with the existing theoretical concepts in these realms of physics. (80 refs).

  14. Simultaneous recordings from the primary visual cortex and lateral geniculate nucleus reveal rhythmic interactions and a cortical source for γ-band oscillations.

    Science.gov (United States)

    Bastos, Andre M; Briggs, Farran; Alitto, Henry J; Mangun, George R; Usrey, W Martin

    2014-05-28

    Oscillatory synchronization of neuronal activity has been proposed as a mechanism to modulate effective connectivity between interacting neuronal populations. In the visual system, oscillations in the gamma-frequency range (30-100 Hz) are thought to subserve corticocortical communication. To test whether a similar mechanism might influence subcortical-cortical communication, we recorded local field potential activity from retinotopically aligned regions in the lateral geniculate nucleus (LGN) and primary visual cortex (V1) of alert macaque monkeys viewing stimuli known to produce strong cortical gamma-band oscillations. As predicted, we found robust gamma-band power in V1. In contrast, visual stimulation did not evoke gamma-band activity in the LGN. Interestingly, an analysis of oscillatory phase synchronization of LGN and V1 activity identified synchronization in the alpha (8-14 Hz) and beta (15-30 Hz) frequency bands. Further analysis of directed connectivity revealed that alpha-band interactions mediated corticogeniculate feedback processing, whereas beta-band interactions mediated geniculocortical feedforward processing. These results demonstrate that although the LGN and V1 display functional interactions in the lower frequency bands, gamma-band activity in the alert monkey is largely an emergent property of cortex. Copyright © 2014 the authors 0270-6474/14/347639-06$15.00/0.

  15. Alpha decay and nuclear deformation: the case for favoured alpha transitions of even-even emitters

    International Nuclear Information System (INIS)

    Garcia, F.; Goncalves, M.; Duarte, S.B.; Tavares, O.A.P.

    2000-02-01

    Alpha-decay half-life for ground-state transitions of 174 even-even alpha emitters has been calculated from a simple, Gamow-like model in which the quadrupole deformation of the product nucleus (assumed to have an ellipsoidal shape) is taken into account. The assumption made is that before tunneling through a purely Coulomb potential barrier the two-body system oscillates isotropically, thus giving rise to an equivalent, average polar direction θ (referred to the symmetry axis of the ellipsoid) for alpha emission. It is shown that the experimental half-life data are much better reproduced by the present description than in the spherical-shaped approximation for the daughter nucleus. (author)

  16. Alpha decay and nuclear deformation: the case for favoured alpha transitions of even-even emitters

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, F. [Universidade Estadual de Santa Cruz, Ilheus, BA (Brazil). Dept. de Ciencias Exatas e Tecnologicas; Rodriguez, O.; Guzman, F. [Instituto Superior de Ciencias y Tecnologia Nucleares (ISCTN), La Habana (Cuba); Goncalves, M. [Instituto de Radioprotecao e Dosimetria IRD/CNEN, Rio de Janeiro, RJ (Brazil); Duarte, S.B.; Tavares, O.A.P. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). E-mail: sbd@cbpf.br

    2000-02-01

    Alpha-decay half-life for ground-state transitions of 174 even-even alpha emitters has been calculated from a simple, Gamow-like model in which the quadrupole deformation of the product nucleus (assumed to have an ellipsoidal shape) is taken into account. The assumption made is that before tunneling through a purely Coulomb potential barrier the two-body system oscillates isotropically, thus giving rise to an equivalent, average polar direction {theta} (referred to the symmetry axis of the ellipsoid) for alpha emission. It is shown that the experimental half-life data are much better reproduced by the present description than in the spherical-shaped approximation for the daughter nucleus. (author)

  17. The pion-nucleus interaction

    International Nuclear Information System (INIS)

    Afnan, I.R.

    1977-04-01

    The latest developments in the construction of pion-nucleus optical potential are presented and a comparison with the latest data on π+ 12 C is made. The suggested mechanisms for the (p,π) reaction are discussed with a comparison of the theoretical results with experiment. (Author)

  18. Alpha clustering in nuclei

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1990-01-01

    The effects of nucleon clustering in nuclei are described, with reference to both nuclear structure and nuclear reactions, and the advantages of using the cluster formalism to describe a range of phenomena are discussed. It is shown that bound and scattering alpha-particle states can be described in a unified way using an energy-dependent alpha-nucleus potential. (author)

  19. Particle correlations in proton-nucleus and nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Nagamiya, Sh.

    1981-01-01

    Particle correlations in proton-nucleus and nucleus-nucleus collisions at energies of 1-2 GeV/nucleon are investigated. The problems of measurement of the mean free path lambda of protons inside the nucleus and the interaction radius of nucleus-nucleus collisions is considered. The value of lambda has been determined in two-proton coincidence experiment in proton-nucleus interaction at 800 MeV. The observed value of lambda is slightly longer than the expected from free nucleon-nucleon collisions. Some preliminary results on proton emission beyond free nucleon-nucleon kinemaics are given

  20. Anisotropy of favoured alpha transitions producing even-even deformed nuclei

    International Nuclear Information System (INIS)

    Tavares, O.A.P.

    1997-05-01

    The anisotropy in favoured alpha transitions which produce even-even deformed nuclei is discussed. A simple, Gamow's-like model which takes into account the quadrupole deformation of the product nucleus has been formulated to calculate the alpha decay half-life. It is assumed that before tunneling into a purely Coulomb potential barrier the two-body system oscillated isotropically, thus giving rise to an equivalent, average preferential polar direction θ 0 (referred to the symmetry axis of the ellipsoidal shape of the product nucleus) for alpha emission in favoured alpha transitions of even-even nuclei. (author)

  1. What can we learn from high-energy hadron-nucleus interactions

    International Nuclear Information System (INIS)

    Tow, D.M.

    1979-12-01

    High-energy hadron-nucleus (hA) collisions provide the exciting possibility of giving information about the spacetime development of hadron-hadron interactions and therefore differentiating various multiparticle production models. Some of the major developments in this field during the past decade, both experimentally and theoretically are reviewed. Several general features of the data are pointed out, and several classes of models are discussed. A recently proposed simple spacetime model for high-energy hA collisions is elaborated. Comments are made on the extension to nucleus-nucleus interactions and the future outlook

  2. Experimental problems of search for quark-gluon plasma in nucleus-nucleus interactions

    International Nuclear Information System (INIS)

    Okonov, Eh.O.

    1987-01-01

    Experimental problems for searching for quark-gluon (quagma) plasma in nucleus-nucleus interactions (NbNb,CaCa, ArPb, CnE, ONe) in the energy range E=0.4-1 GeV/A and 3.67 GeV/A and 200 GeV/A energies are discussed. Peculiarities of performing experiments on Dubna synchrophasotron and SPS Bevalac are discussed. The first results prove hadron matter thermalization sufficient for quagma manifestation. It is found that such characteristics of studied interactions as relative λ-hyperon yield, spectral (temperature) characteristics of λ k -hyperons (with higher values of transferred transverse momenta) and associatively produced peons are of greatest interest. The necessity of precise establishment of λ-hyperon group as excessive and differing in its origin from the other particles of the hadron phase is noted. It is shown that experimental approach used in Dubna research proved efficient and requires further development. It includes : selection of rare events (fluctuations) in central interactions of nuclei with high local excitation; search and research of peculiarities in the production of strange particles and in associative pion production; use of streamer spectrometer with a trigger system of rigid selection of central interactions

  3. Weak interaction and nucleus: the relationship keeps on

    International Nuclear Information System (INIS)

    Martino, J.; Frere, J.M.; Naviliat-Cuncic, O.; Volpe, C.; Marteau, J.; Lhuillier, D.; Vignaud, D.; Legac, R.; Marteau, J.; Legac, R.

    2003-01-01

    This document gathers the lectures made at the Joliot-Curie international summer school in 2003 whose theme, that year, was the relationship between weak interaction and nucleus. There were 8 contributions whose titles are: 1) before the standard model: from beta decay to neutral currents; 2) the electro-weak theory and beyond; 3) testing of the standard model at low energies; 4) description of weak processes in nuclei; 5) 20.000 tonnes underground, an approach to the neutrino-nucleus interaction; 6) parity violation from atom to nucleon; 7) how neutrinos got their masses; and 8) CP symmetry

  4. Nuclear structure and neutrino-nucleus interaction

    International Nuclear Information System (INIS)

    Krmpotic, Francisco

    2011-01-01

    Recent years have witnessed an intense experimental and theoretical activity oriented towards a better comprehension of neutrino nucleus interaction. While the main motivation for this task is the demand coming from oscillation experiments in their search for a precise determination of neutrino properties, the relevance of neutrino interaction with matter is more wide-ranging. It is imperative for astrophysics, hadronic and nuclear physics, and physics beyond the standard model. The experimental information on neutrino induced reactions is rapidly growing, and the corresponding theoretical description is a challenging proposition, since the energy scales of interest span a vast region, going from few MeV for solar neutrinos, to tens of MeV for the interpretation of experiments with the muon and pion decay at rest and the detection of neutrinos coming from the core collapse of supernova, and to hundreds of MeV or few GeV for the detection of atmospheric neutrinos, and for the neutrino oscillation program of the MiniBooNE experiment. The presence of neutrinos, being chargeless particles, can only be inferred by detecting the secondary particles created in colliding and interacting with the matter. Nuclei are often used as neutrino detectors, and in particular 12 C which is a component of many scintillator detectors. Thus, the interpretation of neutrino data heavily relies on detailed and quantitative knowledge of the features of the neutrino-nucleus interaction. The nuclear structure methods used in the evaluation of the neutrino-nucleus cross section are reviewed. Detailed comparison between the experimental and theoretical results establishes benchmarks needed for verification and/or parameter adjustment of the nuclear models. Having a reliable tool for such calculation is of great importance in a variety of applications, such as the description of the r-process nucleosynthesis. (author)

  5. An enlarged superfluid model of atomic nucleus

    International Nuclear Information System (INIS)

    Dumitrescu, O.; Horoi, M.

    1989-01-01

    The well known superfluid model (or quasiparticle phonon nuclear model (QPNM)) of atomic nucleus is enlarged by including an adequate four-nucleon effective interaction in addition to the pairing and long-range effective residual interactions. New experimental data can be explained without affecting those observables already described by the QPNM and in addition new features can be enumerated: 1) superfluidities of the neutron and proton systems may be generated by one another; 2) the phase structure is enriched by a new superfluid phase dominated by alpha-type correlations (ATC) and 3) superfluid isomers and their bands of elementary excitations are predicted. Unusual large two-nucleon and alpha transfer reactions cross sections as well as some unusual large alpha decay widths can be explained. (author). 46 refs, 3 figs, 2 tabs

  6. DNA homologous recombination factor SFR1 physically and functionally interacts with estrogen receptor alpha.

    Directory of Open Access Journals (Sweden)

    Yuxin Feng

    Full Text Available Estrogen receptor alpha (ERα, a ligand-dependent transcription factor, mediates the expression of its target genes by interacting with corepressors and coactivators. Since the first cloning of SRC1, more than 280 nuclear receptor cofactors have been identified, which orchestrate target gene transcription. Aberrant activity of ER or its accessory proteins results in a number of diseases including breast cancer. Here we identified SFR1, a protein involved in DNA homologous recombination, as a novel binding partner of ERα. Initially isolated in a yeast two-hybrid screen, the interaction of SFR1 and ERα was confirmed in vivo by immunoprecipitation and mammalian one-hybrid assays. SFR1 co-localized with ERα in the nucleus, potentiated ER's ligand-dependent and ligand-independent transcriptional activity, and occupied the ER binding sites of its target gene promoters. Knockdown of SFR1 diminished ER's transcriptional activity. Manipulating SFR1 expression by knockdown and overexpression revealed a role for SFR1 in ER-dependent and -independent cancer cell proliferation. SFR1 differs from SRC1 by the lack of an intrinsic activation function. Taken together, we propose that SFR1 is a novel transcriptional modulator for ERα and a potential target in breast cancer therapy.

  7. Alpha-decay within Feshbach theory of nuclear reactions

    International Nuclear Information System (INIS)

    Sandulescu, A.; Silisteanu, I.; Wunsch, R.

    1977-01-01

    In the frame of Feshbach theory of nuclear reactions the alpha-decay widths are determined by the alpha-daughter nucleus optical potential and by the formation factors. It is shown that the calculated absolute values of the alpha widths for Po light isotopes are in good agreement with experimental data, if the real part of the optical potential with the parameters fitted by the low energy α-scattering is used

  8. Study of η-nucleus interaction through the formation of η-nucleus ...

    Indian Academy of Sciences (India)

    Abstract. The question of possible existence of η-mesic nuclei is quite intriguing. An- swer to this question will deeply enrich our understanding of η-nucleus interaction which is not so well-understood. We review the experimental efforts for the search of η-mesic nuclei and describe the physics motivation behind it.

  9. Recent Developments in Neutrino/Antineutrino-Nucleus Interactions

    Directory of Open Access Journals (Sweden)

    Jorge G. Morfín

    2012-01-01

    Full Text Available Recent experimental results and developments in the theoretical treatment of neutrino-nucleus interactions in the energy range of 1–10 GeV are discussed. Difficulties in extracting neutrino-nucleon cross sections from neutrino-nucleus scattering data are explained and significance of understanding nuclear effects for neutrino oscillation experiments is stressed. Detailed discussions of the status of two-body current contribution in the kinematic region dominated by quasielastic scattering and specific features of partonic nuclear effects in weak DIS scattering are presented.

  10. High energy nucleus-nucleus scattering and matter radius of unstable nucleus

    International Nuclear Information System (INIS)

    Sato, H.; Okuhara, Y.

    1985-07-01

    The interaction cross sections of high energy nucleus-nucleus scattering have been studied with the Glauber Model and Hartree-Fock like variational calculation for the nuclear structure. It is found that the experimental interaction cross sections of the light unstable nucleus-stable nucleus scatterings measured by INS-LBL collaboration are well reproduceable. (author)

  11. The calculation of nucleus-nucleus interaction cross sections at high energy in the Glauber approach

    International Nuclear Information System (INIS)

    Gal'perin, A.G.; Uzhinskij, V.V.

    1994-01-01

    Total, inelastic and elastic cross sections of nucleus-nucleus (AA)-interactions at high energy (HE) are calculated on the base of Glauber approach. The calculation scheme is realized as a set of routines. The statistical average method is used in calculations. Program runs in an interactive regime. User is prompted about charge and mass numbers of nuclei and NN-interaction characters at the energy he is interested in: total cross section, the slope parameter of differential cross section of elastic scattering and ratio of real part to imaginary part of elastic scattering amplitude at zero momentum transfer. These data can be extracted from proper compilations. Results of calculations are displayed and are written on user defined output file. The program runs on PC. 21 refs., 1 tab

  12. On the hadron formation time in pion-nucleus interaction

    International Nuclear Information System (INIS)

    Bravina, L.V.; Korotkikh, V.L.; Sarycheva, L.I.; Sivoklokov, S.Yu.

    1992-01-01

    Differences in the observable characteristics of pion-nucleus interactions at high energy are investigated for two definitions of the hadron formation time. The Monte Carlo simulation of hadron-nucleus interactions and quark-gluon string model for hadron-hadron collisions are used. It is shown that the momentum spectrum of the protons in the target fragmentation region is most sensitive to the definition of the formation time. The inclusive meson and meson resonance spectra are similar in the both versions. 20 refs.; 4 figs.; 1 tab

  13. High energy nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Bhalla, K.B.

    1980-01-01

    An attempt is made to explain nucleus-nucleus collisions based on nuclear emulsion experiments. Peripheral and central collisions are described in detail. Assuming the fireball model, the concepts of geometry, kinematics and thermodynamics in this model are discussed. Projectile and target fragmentations are studied. The advantages of using nuclear emulsions as detectors, are mentioned. Proton-nucleus collisions and nucleus-nucleus collisions are compared. Interactions, of projectiles such as Ca, B and C on targets such as Pb, Ag, Br etc. at very high energies (approximately 300 to 1700 Gev) are listed. A comparison of the near multiplicities in these interactions is given. A generalized explanation is given on the processes involved in these interactions. (A.K.)

  14. On slow particle production in hadron-nucleus interactions

    International Nuclear Information System (INIS)

    Stenlund, E.; Otterlund, I.

    1982-01-01

    A model for slow particle production in hadron-nucleus interactions is presented. The model succesfully predicts correlations between the number of knock-on particles and the number of particles associated with the evaporation process as well as correlations with the number of collisions, ν, between the incident hadron and the nucleons inside the target nucleus. The model provides two independent possibilities to determine the number of primary intranuclear collisions, ν, i.e. by its correlation to the number of knock-on particles or to the number of evaporated particles. The good agreement indicates that the model gives an impact-parameter sensitive description of hardron nucleus reactions. (orig.)

  15. Nucleus-Nucleus Scattering in the High-Energy Approximation and the Optical Folding Potential

    CERN Document Server

    Lukyanov, V K; Lukyanov, K V

    2004-01-01

    For the nucleus-nucleus scattering, the complex potential is obtained which corresponds to the eikonal phase of an optical limit of the Glauber-Sitenko high-energy approximation. The potential does not include free parameters, its real and imaginary parts depend on energy and are determined by the reported data on the nuclear density distributions and nucleon-nucleon scattering amplitude. Alternatively, for the real part, the folding potential can be utilized which includes the effective NN-forces and the exchange term, as well. As a result, the microscopic optical potential is constructed where contributions of the calculated real and imaginary parts are formed by fitting the two respective factors. An efficient of the approach is confirmed by agreements of calculations with the experimental data on elastic scattering cross-sections.

  16. On surface clustering and Pauli principle effects in alpha decay

    International Nuclear Information System (INIS)

    Holan, S.

    1983-01-01

    The importance of the correct description of nuclear surface region in alpha decay calculations is pointed out. A model is proposed takinq into account explicitly surface clustering and Pauli principle effects which are essential in this region. A method for solving the main integrodifferential equation of the model by using the oscillator shell basis and the Collatz method is worked out. The first numerical results are obtained for nonlocal potential of the atpha particle-daughter nucleus interaction

  17. Experimental studies of pion-nucleus interactions at intermediate energies

    International Nuclear Information System (INIS)

    1991-01-01

    This report summarizes the work on experimental research in intermediate energy nuclear physics carried out at New Mexico State University in 1991 under a great from the US Department of Energy. Most of these studies have involved investigations of various pion-nucleus interactions. The work has been carried out both with the LAMPF accelerator at the Los Alamos National Laboratory and with the cyclotron at the Paul Scherrer Institute (PSI) near Zurich, Switzerland. Part of the experimental work involves measurements of new data on double-charge-exchange scattering, using facilities at LAMPF which we helped modify, and on pion absorption, using a new detector system at PSI that covers nearly the full solid-angle region which we helped construct. Other work involved preparation for future experiments using polarized nuclear targets and a new high-resolution spectrometer system for detecting π 0 mesons. We also presented several proposals for works to be done in future years, involving studies related to pi-mesonic atoms, fundamental pion-nucleon interactions, studies of the difference between charged and neutral pion interactions with the nucleon, studies of the isospin structure of pion-nucleus interactions, and pion scattering from polarized 3 He targets. This work is aimed at improving our understanding of the pion-nucleon interaction, of the pion-nucleus interaction mechanism, and of nuclear structure

  18. Mechanisms of High Energy Hadron-Nucleus and Nucleus-Nucleus Collision Processes

    International Nuclear Information System (INIS)

    Strugalski, Z.

    1994-01-01

    Mechanisms of high energy hadron-nucleus and nucleus-nucleus collision processes are depicted qualitatively, as prompted experimentally. In hadron-nucleus collisions the interaction of the incident hadron in intranuclear matter is localized in small cylindrical volume, with the radius as large as the strong interaction range is, centered on the hadron course in the nucleus. The nucleon emission is induced by the hadron in its passing through the nucleus; particles are produced via intermediate objects produced in 2 → 2 endoergic reactions of the hadron and its successors with downstream nucleons. In nucleus-nucleus collisions, the outcome of the reaction appears as the composition of statistically independent hadron-nucleus collision outcomes at various impact parameters. Observable effects supporting such mechanisms are discussed. 51 refs

  19. Nucleus-nucleus interaction constants at energies of 0.1-1.0 GeV/nucleon

    International Nuclear Information System (INIS)

    Dudkin, V.E.; P'yanov, I.I.; Stepnov, V.D.

    1979-01-01

    A method for calculating nucleus-nuclear reactions being a further development of the cascade model is proposed. The nucleus-nucleus interaction is represented as a superposition of a series of synchronous cascades initiated by nucleous and α-clusters getting into the nuclei overlapping region. Determination of an interaction partner and calculation of an elementary nucleon and α-cluster collision act are carried out using the same method as for calculation of the nucleon-nuclear cascade. Inelastic channels are not considered. The cross section values of cascade particle interaction, as well as of free particle interaction are given from the published literature. The experiment for verification of the calculation method is carried out. An emulsion chamber of the 0.3 l volume has been exposed at the 35 km height in the vicinity of the 64 deg nothern latitude during 8.5 hr. 223 disintegrations of nuclear emulsion by cosmic radiation nuclei at the 0.1-1.0 GeV/nucleon energy and the >2 charge are investigated. 147 interactions on photoemulsion light nuclei are singled out from these disintegrations. The average multiplicity of all the charged pions is 0.22+-0.05 for light and 0.44+-0.09 for heavy photoemulsion nuclei. The calculation is carried out for nitrogen nuclei interaction at the 0.35 GeV/nucleon energy. Parametric analysis of the calculation method has shown that the clusterization coefficients and the nuclear parameter effect secondary particle multiplicity (SPM) and weakly influence on their energy and angular distributions. The nuclear parameter change from 1.1 to 1.6 F decreases average SPM in different energy ranges down to 25-40%. The comparison of the calculation data with the experimental one obtained in the given paper and other ones, shows satisfactory agreement both for differential and average characteristics of secondary charged particles

  20. Folding model analysis of alpha radioactivity

    International Nuclear Information System (INIS)

    Basu, D N

    2003-01-01

    Radioactive decay of nuclei via emission of α-particles has been studied theoretically in the framework of a superasymmetric fission model using the double folding (DF) procedure for obtaining the α-nucleus interaction potential. The DF nuclear potential has been obtained by folding in the density distribution functions of the α nucleus and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction has been used for calculating the nuclear interaction potential which has been supplemented by a zero-range pseudo-potential for exchange along with the density dependence. The nuclear microscopic α-nucleus potential thus obtained has been used along with the Coulomb interaction potential to calculate the action integral within the WKB approximation. This subsequently yields calculations for the half-lives of α decays of nuclei. The density dependence and the exchange effects have not been found to be very significant. These calculations provide reasonable estimates for the lifetimes of α-radioactivity of nuclei

  1. Future prospects in N-nucleus interactions

    International Nuclear Information System (INIS)

    Moss, J.M.

    1983-01-01

    A detailed examination of two research areas, polarization observables and antiproton-nucleus reactions, which should have near-term future impact on the understanding of the interaction of medium-energy nucleons in nuclei is made. More speculative future experiments employing cooled beams, double spectrometer systems, and large Q-value, low momentum-transfer reactions are also discussed. 25 references, 4 figures

  2. Percolation picture of disintegration of nuclei in the proton-nucleus interaction

    International Nuclear Information System (INIS)

    Botvina, A.S.; Lanin, L.V.

    1992-01-01

    Breakup of nuclei into fragments in the proton-nucleus interaction is studied. It is assumed that breakup occurs in two stages. During the first stage the incident particle interacts with individual nucleons of the nucleus, and high-energy reaction products are emitted from the nucleus. This stage is described by means of the intranuclear-cascade model. During the second stage some of the nuclei, whose excitation energy is high, or whose density is very inhomogeneous, break up. This breakup is described by means of a percolation model which takes into account the spatial distribution of nucleons in the nucleus and which generalizes the percolation description of the 'liquid-gas' phase transition for finite nuclei. Features of this breakup mechanism are studied. The analysis of the experimental data indicates that it is not sufficient to consider percolation only in the coordinate space, and that the momentum distribution of the nucleons in the nucleus must be taken into account

  3. A systematics of optical model compound nucleus formation cross sections for neutrons, proton, deuteron, 3He and alpha particle incidents

    International Nuclear Information System (INIS)

    Murata, Toru

    2000-01-01

    Simple formulae to reproduce the optical model compound nucleus formation cross sections for neutron, proton, deuteron, triton, 3 He and alpha particles are presented for target nuclei of light to medium weight mass region. (author)

  4. Study of the peculiarities of multiparticle production via event-by-event analysis in asymmetric nucleus-nucleus interactions

    Science.gov (United States)

    Fedosimova, Anastasiya; Gaitinov, Adigam; Grushevskaya, Ekaterina; Lebedev, Igor

    2017-06-01

    In this work the study on the peculiarities of multiparticle production in interactions of asymmetric nuclei to search for unusual features of such interactions, is performed. A research of long-range and short-range multiparticle correlations in the pseudorapidity distribution of secondary particles on the basis of analysis of individual interactions of nuclei of 197 Au at energy 10.7 AGeV with photoemulsion nuclei, is carried out. Events with long-range multiparticle correlations (LC), short-range multiparticle correlations (SC) and mixed type (MT) in pseudorapidity distribution of secondary particles, are selected by the Hurst method in accordance with Hurst curve behavior. These types have significantly different characteristics. At first, they have different fragmentation parameters. Events of LC type are processes of full destruction of the projectile nucleus, in which multicharge fragments are absent. In events of mixed type several multicharge fragments of projectile nucleus are discovered. Secondly, these two types have significantly different multiplicity distribution. The mean multiplicity of LC type events is significantly more than in mixed type events. On the basis of research of the dependence of multiplicity versus target-nuclei fragments number for events of various types it is revealed, that the most considerable multiparticle correlations are observed in interactions of the mixed type, which correspond to the central collisions of gold nuclei and nuclei of CNO-group, i.e. nuclei with strongly asymmetric volume, nuclear mass, charge, etc. Such events are characterised by full destruction of the target-nucleus and the disintegration of the projectile-nucleus on several multi-charged fragments.

  5. Study of the peculiarities of multiparticle production via event-by-event analysis in asymmetric nucleus-nucleus interactions

    Directory of Open Access Journals (Sweden)

    Fedosimova Anastasiya

    2017-01-01

    Full Text Available In this work the study on the peculiarities of multiparticle production in interactions of asymmetric nuclei to search for unusual features of such interactions, is performed. A research of long-range and short-range multiparticle correlations in the pseudorapidity distribution of secondary particles on the basis of analysis of individual interactions of nuclei of 197 Au at energy 10.7 AGeV with photoemulsion nuclei, is carried out. Events with long-range multiparticle correlations (LC, short-range multiparticle correlations (SC and mixed type (MT in pseudorapidity distribution of secondary particles, are selected by the Hurst method in accordance with Hurst curve behavior. These types have significantly different characteristics. At first, they have different fragmentation parameters. Events of LC type are processes of full destruction of the projectile nucleus, in which multicharge fragments are absent. In events of mixed type several multicharge fragments of projectile nucleus are discovered. Secondly, these two types have significantly different multiplicity distribution. The mean multiplicity of LC type events is significantly more than in mixed type events. On the basis of research of the dependence of multiplicity versus target-nuclei fragments number for events of various types it is revealed, that the most considerable multiparticle correlations are observed in interactions of the mixed type, which correspond to the central collisions of gold nuclei and nuclei of CNO-group, i.e. nuclei with strongly asymmetric volume, nuclear mass, charge, etc. Such events are characterised by full destruction of the target-nucleus and the disintegration of the projectile-nucleus on several multi-charged fragments.

  6. Theories of the eta-meson-nucleus interaction

    International Nuclear Information System (INIS)

    Liu, L.C.

    1994-01-01

    It is sown that the pion-nucleon elastic scattering, eta-nucleon scattering length and the cross sections for pion-induced eta production on a nucleon satisfy a set of consistency relations. These relations are used to examine the ηN scattering lengths given by the various models. The nature of the threshold ηN interaction is discussed and recent advancements in ηN interaction is discussed and recent advancements in η-nucleus reaction theory are reviewed

  7. Semiclassical model for single-particle transitions in nucleus-nucleus interactions

    International Nuclear Information System (INIS)

    Milek, B.; Joint Inst. for Nuclear Research, Dubna; Technische Univ., Dresden; Reif, R.; Pham Khan Van; Revai, J.

    1990-04-01

    A previously elaborated semiclassical one-body model for the dynamics of a single particle, moving in two potentials, in heavy-ion reactions or in fissioning systems has been extended with respect to the inclusion of angular momenta and more realistic separable potentials. The collective relative motion is assumed to proceed along a trajectory which is calculated from classical equations of motion including conservative and phenomenological friction forces. The formalism has been derived involving three-dimensional trajectories for symmetric as well as for asymmetric nucleus-nucleus systems. The model allows for the calculation of correct quantum mechanical transition amplitudes to final bound and continuum states. It has been applied for the investigation of the excitation of a neutron during a fission process, covering also non-statistical differential emission probabilities. From the numerical calculations, using parameters adapted to 252 Cf(sf), one can conclude that in the underlying model without 'sudden' processes the energy spectrum consists of two parts. The low lying component is created in the neck region while a high lying part seems to be governed mainly by the dynamics of the underlying collective motion rather than by the specific initial conditions. (orig.)

  8. Calculations of antiproton nucleus quasi-bound states using the Paris (N)over-barN potential

    Czech Academy of Sciences Publication Activity Database

    Hrtánková, Jaroslava; Mareš, Jiří

    2018-01-01

    Roč. 969, č. 1 (2018), s. 45-59 ISSN 0375-9474 R&D Projects: GA ČR(CZ) GA15-04301S Institutional support: RVO:61389005 Keywords : antiproton-nucleus interaction * Paris (N)over-barN potential * antiproton-nuclear bound states Subject RIV: BE - Theoretical Physics OBOR OECD: Atomic, molecular and chemical physics ( physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect) Impact factor: 1.916, year: 2016

  9. Interesting correlations among various parameters of charged secondaries in nucleus - nucleus interactions at 4.5 A GeV

    International Nuclear Information System (INIS)

    Khan, M. Saleem; Shukla, Praveen Prakash; Khushnood, H.

    2015-01-01

    The study of the characteristic of charged secondaries was the aim of most of the experiments on high energy nucleon-nucleon and nucleus-nucleus collisions. Investigation are carried out on the produced secondary charged particles with a common belief that these particles are more informative about the collisional dynamics and thus, could be effective in revealing the underlying physics of high energy relativistic interactions. So for understanding the mechanism of multiparticle production in high energy hadron-nucleus collisions, the correlations amongst the secondary charged particles are studied. Several workers have attempted to study the multiplicity correlations over widely different incident energies with different projectiles. The AALMT collaboration have also studied the multiplicity correlations in 200 GeV proton-nucleus collisions

  10. Nucleus-nucleus total reaction cross sections

    International Nuclear Information System (INIS)

    DeVries, R.M.; Peng, J.C.

    1980-01-01

    We compare sigma/sub R/(E) for nucleus-nucleus systems (obtained from existing direct measurements and derived from elastic scattering data) with nucleon-nucleon and nucleon-nucleus data. The energy dependence of sigma/sub R/(E) for nucleus-nucleus systems is found to be quite rapid; there appears to be no evidence for an energy independent, geometric sigma/sub R/. Simple parameter free microscopic calculations are able to quantitatively reproduce the data and thus, emphasize the dominance of nucleon-nucleon interactions in medium energy nucleus-nucleus collisions

  11. Weak interaction and nucleus: the relationship keeps on; Interaction faible et noyau: l'histoire continue

    Energy Technology Data Exchange (ETDEWEB)

    Martino, J [Subatech, Ecole des Mines de Nantes, 44 - Nantes (France); Frere, J M; Naviliat-Cuncic, O; Volpe, C; Marteau, J; Lhuillier, D; Vignaud, D; Legac, R; Marteau, J; Legac, R

    2003-07-01

    This document gathers the lectures made at the Joliot-Curie international summer school in 2003 whose theme, that year, was the relationship between weak interaction and nucleus. There were 8 contributions whose titles are: 1) before the standard model: from beta decay to neutral currents; 2) the electro-weak theory and beyond; 3) testing of the standard model at low energies; 4) description of weak processes in nuclei; 5) 20.000 tonnes underground, an approach to the neutrino-nucleus interaction; 6) parity violation from atom to nucleon; 7) how neutrinos got their masses; and 8) CP symmetry.

  12. Alpha decay and various problems related to it

    International Nuclear Information System (INIS)

    Katori, Kenji

    1992-01-01

    On the proton-excessive nucleus side of lanthanide and actinide, alpha decay is the main decay mode. In lanthanide region, alpha decay has been measured to the drip line for most even-even nuclei. In the measurement of alpha decay, emitted energy and life are measured, but the measurement of converted alpha width remains in the limited range. In order to obtain the converted alpha width of high accuracy, the nucleus formation in larger quantity on the drip line and the simultaneous measurement with a multiple detector system including gamma ray and beta ray are required. In this paper, three topics related to alpha cluster and alpha decay and the problems that confront at present are discussed. The continuation to exist of alpha cluster structure to heavy nuclei, the analysis of lanthanide nucleus region by the alpha giant resonance model, and the new data on the alpha ray decaying from the mass of 175, 176 and 177 are reported. In lanthanide nucleus region, remarkable interference was not observed between beta-2 and beta-3 modes in the converted alpha width measured between the ground states. The present problems in alpha decay are enumerated. (K.I.)

  13. Interaction cross sections and pions minus multiplicities on nucleus-nucleus collisions at 4.2 GeV/c per nucleon

    International Nuclear Information System (INIS)

    Angelov, N.; Ahababyan, N.; Anoshin, A.I.

    1979-01-01

    Data are presented on inelastic cross sections and multiplicities of pions minus produced on collisions of protons, deuterons, helium-4 and carbon-12 nuclei at 4.2 GeV/c per nucleon in the propane bubble chamber witn tantalum and carbon plates. Average multiplicities and dispersions of multiplicity distributions are compared with those in nucleon-nucleon interactions. Deviation of C-Ta interaction data from universal dependence of dispersion on multiplicity is observed. Pion multiplicities are found proportional to the number of nucleons from incident nucleus which interacted in the target. The results are not in contradiction with the assumption that nucleons from the incident nucleus interact independently in the target. For C-Ta interactions the average radius of the pion emission volume has been determined by the interference method to be r=(3.3+-0.6) fm

  14. Investigation of the Pygmy Dipole Resonance in (alpha, alpha 'gamma) coincidence experiments

    NARCIS (Netherlands)

    Savran, D.; Babilon, M.; van den Berg, A. M.; Harakeh, M. N.; Hasper, J.; Wortche, H. J.; Zilges, A.

    2007-01-01

    We report on first results from experiments using the (alpha, alpha'gamma) reaction at E alpha = 136 MeV to investigate bound electric dipole (El) excitations building the so-called Pygmy Dipole Resonance (PDR) in the semi-magic nucleus Ce-140. The method of (alpha, alpha'gamma) allows the

  15. Models of the atomic nucleus. With interactive software

    International Nuclear Information System (INIS)

    Cook, N.D.

    2006-01-01

    This book-and-CD-software package supplies users with an interactive experience for nuclear visualization via a computer-graphical interface, similar in principle to the molecular visualizations already available in chemistry. Models of the Atomic Nucleus, a largely non-technical introduction to nuclear theory, explains the nucleus in a way that makes nuclear physics as comprehensible as chemistry or cell biology. The book/software supplements virtually any of the current textbooks in nuclear physics by providing a means for 3D visual display of the diverse models of nuclear structure. For the first time, an easy-to-master software for scientific visualization of the nucleus makes this notoriously ''non-visual'' field become immediately 'visible.' After a review of the basics, the book explores and compares the competing models, and addresses how the lattice model best resolves remaining controversies. The appendix explains how to obtain the most from the software provided on the accompanying CD. (orig.)

  16. Karyopherin alpha7 (KPNA7), a divergent member of the importin alpha family of nuclear import receptors.

    Science.gov (United States)

    Kelley, Joshua B; Talley, Ashley M; Spencer, Adam; Gioeli, Daniel; Paschal, Bryce M

    2010-08-11

    Classical nuclear localization signal (NLS) dependent nuclear import is carried out by a heterodimer of importin alpha and importin beta. NLS cargo is recognized by importin alpha, which is bound by importin beta. Importin beta mediates translocation of the complex through the central channel of the nuclear pore, and upon reaching the nucleus, RanGTP binding to importin beta triggers disassembly of the complex. To date, six importin alpha family members, encoded by separate genes, have been described in humans. We sequenced and characterized a seventh member of the importin alpha family of transport factors, karyopherin alpha 7 (KPNA7), which is most closely related to KPNA2. The domain of KPNA7 that binds Importin beta (IBB) is divergent, and shows stronger binding to importin beta than the IBB domains from of other importin alpha family members. With regard to NLS recognition, KPNA7 binds to the retinoblastoma (RB) NLS to a similar degree as KPNA2, but it fails to bind the SV40-NLS and the human nucleoplasmin (NPM) NLS. KPNA7 shows a predominantly nuclear distribution under steady state conditions, which contrasts with KPNA2 which is primarily cytoplasmic. KPNA7 is a novel importin alpha family member in humans that belongs to the importin alpha2 subfamily. KPNA7 shows different subcellular localization and NLS binding characteristics compared to other members of the importin alpha family. These properties suggest that KPNA7 could be specialized for interactions with select NLS-containing proteins, potentially impacting developmental regulation.

  17. Development of global medium-energy nucleon-nucleus optical model potentials

    International Nuclear Information System (INIS)

    Madland, D.G.; Sierk, A.J.

    1997-01-01

    The authors report on the development of new global optical model potentials for nucleon-nucleus scattering at medium energies. Using both Schroedinger and Dirac scattering formalisms, the goal is to construct a physically realistic optical potential describing nucleon-nucleus elastic scattering observables for a projectile energy range of (perhaps) 20 meV to (perhaps) 2 GeV and a target mass range of 16 to 209, excluding regions of strong nuclear deformation. They use a phenomenological approach guided by conclusions from recent microscopic studies. The experimental database consists largely of proton-nucleus elastic differential cross sections, analyzing powers, spin-rotation functions, and total reaction cross sections, and neutron-nucleus total cross sections. They will use this database in a nonlinear least-squares adjustment of optical model parameters in both relativistic equivalent Schroedinger (including relativistic kinematics) and Dirac (second-order reduction) formalisms. Isospin will be introduced through the standard Lane model and a relativistic generalization of that model

  18. Microscopic theory for nucleon-nucleus optical potential in intermediate energies

    International Nuclear Information System (INIS)

    He Guozhu; Cai Chonghai

    1984-01-01

    Based on the scattering theory of KMT and FGH we calculate the nucleon-nucleus optical potentials of 4 He, 16 O and 40 Ca from the Paris N-N potential given by M. Lacombe et al. The real part Vsub(R)(r) of our optential has the form of Woods-Saxon when the kinetic energy E of the incident nucleon is low. The depth of Vsub(R)(r) will decrease as E increases, and it turns into positive in the interior of nucleus when E approx.= 300 MeV. The repulsive effect in the interior of nucleus increases rapidly as E increases even more, butthere always exists some attractive effect at the surface of nucleus. Therefore, Vsub(R)(r) has generally the wine-bottle bottom shape. We also calculate the quatity Jv/N = (4π/N)∫sub(0)sub(infinity)Vsub(R)(r)r 2 dr. Our results are basically in acordance with those of M.Jaminon et al's relativistic Hatree calculation as well as the experimental results. In this work we also calculate the imaginary part of optical potential and its variation with the kinetic energy of the incident nucleon

  19. Social interaction reward decreases p38 activation in the nucleus accumbens shell of rats.

    Science.gov (United States)

    Salti, Ahmad; Kummer, Kai K; Sadangi, Chinmaya; Dechant, Georg; Saria, Alois; El Rawas, Rana

    2015-12-01

    We have previously shown that animals acquired robust conditioned place preference (CPP) to either social interaction alone or cocaine alone. Recently it has been reported that drugs of abuse abnormally activated p38, a member of mitogen-activated protein kinase family, in the nucleus accumbens. In this study, we aimed to investigate the expression of the activated form of p38 (pp38) in the nucleus accumbens shell and core of rats expressing either cocaine CPP or social interaction CPP 1 h, 2 h and 24 h after the CPP test. We hypothesized that cocaine CPP will increase pp38 in the nucleus accumbens shell/core as compared to social interaction CPP. Surprisingly, we found that 24 h after social interaction CPP, pp38 neuronal levels were decreased in the nucleus accumbens shell to the level of naïve rats. Control saline rats that received saline in both compartments of the CPP apparatus and cocaine CPP rats showed similar enhanced p38 activation as compared to naïve and social interaction CPP rats. We also found that the percentage of neurons expressing dopaminergic receptor D2R and pp38 was also decreased in the shell of the nucleus accumbens of social interaction CPP rats as compared to controls. Given the emerging role of p38 in stress/anxiety behaviors, these results suggest that (1) social interaction reward has anti-stress effects; (2) cocaine conditioning per se does not affect p38 activation and that (3) marginal stress is sufficient to induce p38 activation in the shell of the nucleus accumbens. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. η-nucleus interaction from the d + d reaction around the η production threshold

    Energy Technology Data Exchange (ETDEWEB)

    Ikeno, N. [Tottori University, Department of Life and Environmental Agricultural Sciences, Tottori (Japan); Nagahiro, H. [Nara Women' s University, Department of Physics, Nara (Japan); Osaka University, Research Center for Nuclear Physics (RCNP), Ibaraki (Japan); Jido, D. [Tokyo Metropolitan University, Department of Physics, Hachioji (Japan); Hirenzaki, S. [Nara Women' s University, Department of Physics, Nara (Japan)

    2017-10-15

    The η mesic nucleus is considered to be one of the interesting exotic many-body systems and has been studied since the 1980s theoretically and experimentally. Recently, the formation of the η mesic nucleus in the fusion reactions of the light nuclei such as d + d → (η + α) → X has been proposed and the experiments have been performed by WASA-at-COSY. We develop a theoretical model to evaluate the formation rate of the η mesic nucleus in the fusion reactions and show the calculated results. We find that the η bound states could be observed in the reactions in cases with the strong attractive and small absorptive η-nucleus interactions. We compare our results with existing data of the d + d → η + α and the d + d → {sup 3}He + N + π reactions. We find that the analyses by our theoretical model with the existing data can provide new information on the η-nucleus interaction. (orig.)

  1. Direct observation of nanoparticle-cancer cell nucleus interactions.

    Science.gov (United States)

    Dam, Duncan Hieu M; Lee, Jung Heon; Sisco, Patrick N; Co, Dick T; Zhang, Ming; Wasielewski, Michael R; Odom, Teri W

    2012-04-24

    We report the direct visualization of interactions between drug-loaded nanoparticles and the cancer cell nucleus. Nanoconstructs composed of nucleolin-specific aptamers and gold nanostars were actively transported to the nucleus and induced major changes to the nuclear phenotype via nuclear envelope invaginations near the site of the construct. The number of local deformations could be increased by ultrafast, light-triggered release of the aptamers from the surface of the gold nanostars. Cancer cells with more nuclear envelope folding showed increased caspase 3 and 7 activity (apoptosis) as well as decreased cell viability. This newly revealed correlation between drug-induced changes in nuclear phenotype and increased therapeutic efficacy could provide new insight for nuclear-targeted cancer therapy.

  2. Interactions between an alpha-helix and a beta-sheet. Energetics of alpha/beta packing in proteins.

    Science.gov (United States)

    Chou, K C; Némethy, G; Rumsey, S; Tuttle, R W; Scheraga, H A

    1985-12-05

    Conformational energy computations have been carried out to determine the favorable ways of packing a right-handed alpha-helix on a right-twisted antiparallel or parallel beta-sheet. Co-ordinate transformations have been developed to relate the position and orientation of the alpha-helix to the beta-sheet. The packing was investigated for a CH3CO-(L-Ala)16-NHCH3 alpha-helix interacting with five-stranded beta-sheets composed of CH3CO-(L-Val)6-NHCH3 chains. All internal and external variables for both the alpha-helix and the beta-sheet were allowed to change during energy minimization. Four distinct classes of low-energy packing arrangements were found for the alpha-helix interacting with both the parallel and the anti-parallel beta-sheet. The classes differ in the orientation of the axis of the alpha-helix relative to the direction of the strands of the right-twisted beta-sheet. In the class with the most favorable arrangement, the alpha-helix is oriented along the strands of the beta-sheet, as a result of attractive non-bonded side-chain-side-chain interactions along the entire length of the alpha-helix. A class with nearly perpendicular orientation of the helix axis to the strands is also of low energy, because it allows similarly extensive attractive interactions. In the other two classes, the helix is oriented diagonally relative to the strands of the beta-sheet. In one of them, it interacts with the convex surface near the middle of the saddle-shaped twisted beta-sheet. In the other, it is oriented along the concave diagonal of the beta-sheet and, therefore, it interacts only with the corner regions of the sheet, so that this packing is energetically less favorable. The packing arrangements involving an antiparallel and a parallel beta-sheet are generally similar, although the antiparallel beta-sheet has been found to be more flexible. The major features of 163 observed alpha/beta packing arrangements in 37 proteins are accounted for in terms of the computed

  3. Diffractive ''semioptical'' model for nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Barashenkov, V.S.; Musulmanbekov, Zh.Zh.

    1979-01-01

    Diffraction Glauber theory for nucleus-nucleus collisions is considered in approximation when the initial nucleus interacts as a whole with nucleons of the target nucleus. Such an approach, being intermediate between precise Glauber theory and its optical limit, essentially simplifies numerical calculations and gives a good agreement with experiments as well. (author)

  4. Cross-sections for neutrino-nucleus interactions on $^{12}C$ and $^{16}O$

    CERN Document Server

    Jachowicz, N; Heyde, Kris L G

    1998-01-01

    We calculate cross sections for neutral current quasi-elastic neutrino-nucleus scattering within a continuum RPA model, based on a Green's function approach. As residual interaction a Skyrme force is used. The unperturbed single particle wave functions are generated using either a Woods-Saxon potential or a Hartree-Fock calculation. These calculations have interesting applications. Neutrinos play an important role in supernova nucleosynthesis. To obtain more information about these processes, cross sections are folded with a Fermi-Dirac distribution with temperatures of approximately 10 9 K.

  5. Inclusive negative-hadron production from high-energy nu-bar-nucleus charged-current interactions

    International Nuclear Information System (INIS)

    Berge, J.P.; Bogert, D.; Endorf, R.; Hanft, R.; Malko, J.A.; Moffatt, G.; Nezrick, F.A.; Scott, W.; Smart, W.; Wolfson, J.; Ammosov, V.V.; Amrakhov, A.H.; Denisov, A.G.; Ermolov, P.F.; Gapienko, V.A.; Klukhin, V.I.; Koreshev, V.I.; Pitukhin, P.V.; Rjabov, V.G.; Slobodyuk, E.A.; Sirotenko, V.I.; Efremenko, V.I.; Gorichev, P.A.; Kaftanov, V.S.; Khovansky, V.D.; Kliger, G.K.; Kolganov, V.Z.; Krutchinin, S.P.; Kubantsev, M.A.; Rosanov, A.N.; Savitsky, M.M.; Shevchenko, V.G.; Coffin, C.T.; Diamond, R.N.; French, H.; Louis, W.; Roe, B.P.; Ross, R.T.; Seidl, A.A.; Sinclair, D.

    1978-01-01

    We present data on inclusive negative-hadron production from charged-current antineutrino interactions in a 21% Ne--H mixture. Inclusive single-particle distributions are presented and are shown to be insensitive to the momentum transferred to the hadron vertex. Comparisons made to inclusive data from π - p and π - n interactions indicate a close similarity between the hadrons resulting from π-nucleon and nu-bar-nucleus interactions. The general features of the nu-bar-nucleus data are found to be similar to those seen in nu-barp interactions. This last observation implies that nu-barp and nu-barn interactions are similar and that nuclear effects are small

  6. The thermal structural transition of alpha-crystallin modulates subunit interactions and increases protein solubility.

    Directory of Open Access Journals (Sweden)

    Giuseppe Maulucci

    Full Text Available BACKGROUND: Alpha crystallin is an oligomer composed of two types of subunits, alpha-A and alpha-B crystallin, and is the major constituent of human lens. The temperature induced condensation of alpha-crystallin, the main cause for eye lens opacification (cataract, is a two step-process, a nucleation followed by an aggregation phase, and a protective effect towards the aggregation is exhibited over the alpha crystallin phase transition temperature (Tc = 318.16 K. METHODS/RESULTS: To investigate if a modulation of the subunit interactions over Tc could trigger the protective mechanism towards the aggregation, we followed, by using simultaneously static and dynamic light scattering, the temperature induced condensation of alpha-crystallin. By developing a mathematical model able to uncouple the nucleation and aggregation processes, we find a previously unobserved transition in the nucleation rate constant. Its temperature dependence allows to determine fundamental structural parameters, the chemical potential (Δμ and the interfacial tension (γ of the aggregating phase, that characterize subunit interactions. CONCLUSIONS/GENERAL SIGNIFICANCE: The decrease of both Δμ and γ at Tc, and a relative increase in solubility, reveal a significative decrease in the strenght of alpha-crystallin subunits interactions, which protects from supramolecolar condensation in hypertermic conditions. On the whole, we suggest a general approach able to understand the structural and kinetic mechanisms involved in aggregation-related diseases and in drugs development and testing.

  7. Weak interaction and nucleus: the relationship keeps on; Interaction faible et noyau: l'histoire continue

    Energy Technology Data Exchange (ETDEWEB)

    Martino, J. [Subatech, Ecole des Mines de Nantes, 44 - Nantes (France); Frere, J.M.; Naviliat-Cuncic, O.; Volpe, C.; Marteau, J.; Lhuillier, D.; Vignaud, D.; Legac, R.; Marteau, J.; Legac, R

    2003-07-01

    This document gathers the lectures made at the Joliot-Curie international summer school in 2003 whose theme, that year, was the relationship between weak interaction and nucleus. There were 8 contributions whose titles are: 1) before the standard model: from beta decay to neutral currents; 2) the electro-weak theory and beyond; 3) testing of the standard model at low energies; 4) description of weak processes in nuclei; 5) 20.000 tonnes underground, an approach to the neutrino-nucleus interaction; 6) parity violation from atom to nucleon; 7) how neutrinos got their masses; and 8) CP symmetry.

  8. The imaginary part of the local potential equivalent to the non-local α-nucleus optical potential

    International Nuclear Information System (INIS)

    Lassaut, M.; Vinh Mau, N.

    1982-01-01

    A simple expression of the α-nucleus optical potential has been derived from the Feshbach formula by using a closure approximation for summing over the excited states of the target nucleus. It has been shown that the correction to the real folding model potential is small. The imaginary local potential equivalent to the non-local Feshbach potential has been studied in detail for Ca nuclei and shown to reproduce quite well the gross properties of empirical potentials above 100 MeV with, however, a lack of absorption in the surface region. The A-dependence of the imaginary potential volume integral has also been investigated. (orig.)

  9. Invariant potential for elastic pion--nucleus scattering. Technical report No. 75-075

    International Nuclear Information System (INIS)

    Cammarata, J.B.; Banerjee, M.K.

    1975-04-01

    From the Wick-Dyson expansion of the exact propagator of a pion in the presence of a nucleus an invariant potential for crossing symmetric, elastic pion-nucleus scattering is obtained in terms of a series of pion-nucleon diagrams. The Chew-Low theory is used to develop a model in which the most important class of diagrams is effectively summed. Included in this model is the Exclusion Principle restriction on the pion-bound nucleon interaction, the effects of the binding of nucleons, a kinematic transformation of energy from the lab to the πN center of mass frames, and the Fermi motion and recoil of the target nucleons. From a numerical study of the effects of these processes on the π- 12 C total cross section, the relative importance of each is determined. Other processes contributing to the elastic scattering of pions not included in the present model are also discussed. (9 figures) (U.S.)

  10. Study of Hadron Production in Hadron-Nucleus and Nucleus-Nucleus Collisions at the CERN SPS

    CERN Multimedia

    Klochkov, V; Herve, A E; Kowalski, S; Kaptur, E A; Kowalik, K L; Dominik, W M; Matulewicz, T N; Krasnoperov, A; Feofilov, G; Vinogradov, L; Kovalenko, V; Johnson, S R; Planeta, R J; Rubbia, A; Marton, K; Messerly, B A; Puzovic, J; Bogomilov, M V; Bravar, A; Renfordt, R A E; Deveaux, M; Engel, R R; Grzeszczuk, A; Davis, N; Kuich, M; Lyubushkin, V; Kondratev, V; Kadija, K; Diakonos, F; Slodkowski, M A; Rauch, W H; Pistillo, C; Laszlo, A; Nakadaira, T; Hasegawa, T; Sadovskiy, A; Morozov, S; Petukhov, O; Mathes, H; Roehrich, D; Marcinek, A J; Marino, A D; Grebieszkow, K; Di luise, S; Wlodarczyk, Z; Rybczynski, M A; Wojtaszek-szwarc, A; Nirkko, M C; Sakashita, K; Golubeva, M; Kurepin, A; Manic, D; Kolev, D I; Kisiel, J E; Koziel, M E; Rondio, E; Larsen, D T; Czopowicz, T R; Seyboth, P; Turko, L; Guber, F; Marin, V; Busygina, O; Strikhanov, M; Taranenko, A; Cirkovic, M; Roth, M A; Pulawski, S M; Aduszkiewicz, A M; Bunyatov, S; Vechernin, V; Nagai, Y; Anticic, T; Dynowski, K M; Mackowiak-pawlowska, M K; Stefanek, G; Pavin, M; Fodor, Z P; Nishikawa, K; Tada, M; Blondel, A P P; Stroebele, H W; Posiadala, M Z; Kolesnikov, V; Andronov, E; Zimmerman, E D; Antoniou, N; Majka, Z; Dumarchez, J; Naskret, M; Ivashkin, A; Tsenov, R V; Koziel, M G; Schmidt, K J; Melkumov, G; Popov, B; Panagiotou, A; Richter-was, E M; Morgala, S J; Paolone, V; Damyanova, A; Gazdzicki, M; Unger, M T; Wilczek, A G; Stepaniak, J M; Seryakov, A; Susa, T; Staszel, P P; Brzychczyk, J; Maksiak, B; Tefelski, D B

    2007-01-01

    The NA61/SHINE (SHINE = SPS Heavy Ion and Neutrino Experiment) experiment is a large acceptance hadron spectrometer at the CERN SPS for the study of the hadronic final states produced in interactions of various beam particles (pions, protons, C, S and In) with a variety of fixed targets at the SPS energies. The main components of the current detector were constructed and used by the NA49 experiment. The physics program of NA61/SHINE consists of three main subjects. In the first stage of data taking (2007-2009) measurements of hadron production in hadron-nucleus interactions needed for neutrino (T2K) and cosmic-ray (Pierre Auger and KASCADE) experiments will be performed. In the second stage (2009-2011) hadron production in proton-proton and proton-nucleus interactions needed as reference data for a better understanding of nucleus-nucleus reactions will be studied. In the third stage (2009-2013) energy dependence of hadron production properties will be measured in nucleus-nucleus collisions as well as in p+p a...

  11. On the geometric nature of high energy nucleus-nucleus reaction cross sections

    International Nuclear Information System (INIS)

    Townsend, L.W.; Wilson, J.W.; Bidasaria, H.B.

    1982-01-01

    Within the context of a high energy double-folding optical potential approximation to the exact nucleus-nucleus multiple-scattering series, eikonal scattering theory is used to investigate the validity of geometric reaction cross sections in relativistic heavy ion collisions. The potential used includes a finite range interaction and nuclear single-particle densities extracted from nuclear charge distributions by unfolding the proton charge distribution. Pauli correlation effects are also included in an approximate way. The sensitivity of the predictions to be assumed interaction, Pauli correlation approximation, and nuclear density distributions is investigated. These results are in agreement with early predictions concerning the geometric nature of relativistic heavy ion collisions and in disagreement with a recent analysis, utilizing the zero range approximation, which suggested otherwise. Reasons for the lack of agreement between the analyses are also presented. Finally, approximate applicability for geometric reaction cross sections are determined

  12. The Atomic Mass Dependence of Massive Muon Pair Production in 225 GeV/c $\\pi$ - Nucleus Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Swartz, Morris L. [Chicago U.

    1984-03-01

    The production of massive muon pairs in 225 GeV/c $\\pi^-$-nucleus interactions has been studied for four nuclear targets. The dependence of the integrated cross section on atomic mass A was measured by comparing the relative cross sections for the targets. If one assumes that the cross section is proportional to $A^{\\alpha}$, a value of a= 1.00±0.06 for muon pair masses between 4.0 GeV/$c^2$ and 8.5 GeV/$c^2$ was obtained. The Drell-Yan model predicts an additional dependence of the cross section on the proton fraction Z/A. If one parametizes the integrated cross I section as a(Z/A)$A^{\\alpha}$ where $\\sigma$(Z/A) is a function of the proton fraction that includes the effects of the Drell-Yan model, Fermi Motion, and secondary pion production, a value of $\\alpha$ = 0.97±0.06 was obtained. The dependence of the muon pair transverse momentum distribution on nuclear size was also investigated. The second moment of the distribution <$P^2_T$> was found to be consistent with being independent of nuclear size. If the dependence of <$P^2_T$> on nuclear size is parametized as <$P^2_T$> = a + b $A^{1/3}$ the coefficient b was found to be less than 0.015 $GeV^2$/$c^2$ with 90% confidence.

  13. New computational methods for determining antikaon-nucleus bound states

    International Nuclear Information System (INIS)

    Fink, P.J. Jr.

    1989-01-01

    Optical potential for antikaon-nucleus strong interactions are constructed using elementary antikaon-nucleus potentials determined previously. The optical potentials are used to determine the existence of a kaon hypernucleus. Modern three dimensional visualization techniques are used to study model dependences, new methods for speeding the calculation of the optical potential are developed, and previous approximation to avoid full Fermi averaging are eliminated. 19 refs., 21 figs., 3 tabs

  14. Determining the meson-nucleus potential - on the way to mesic states

    Energy Technology Data Exchange (ETDEWEB)

    Metag, Volker, E-mail: volker.metag@exp2.physik.uni-giessen.de [Universität Giessen, II. Physikalisches Institut (Germany)

    2015-08-15

    Experimental approaches to determine the real and imaginary part of the meson-nucleus potential are described. The experiments have been performed with the Crystal Barrel/TAPS detector at the electron accelerator ELSA (Bonn) and the Crystal Ball/TAPS detector at MAMI (Mainz). Measuring the transparency ratio as well as the excitation function and momentum distribution for photo production of ω and η′ mesons, the imaginary part of the η′-nucleus potential is found to be smaller than the real part. In case of the ω meson the opposite is observed. This makes the η′ meson a good candidate for the search for meson-nucleus bound states while no resolved ω mesic states can be expected. The results are discussed and compared to theoretical predictions. An outlook on future experiments is given.

  15. Stochastic interaction between TAE and alpha particles

    International Nuclear Information System (INIS)

    Krlin, L.; Pavlo, P.; Malijevsky, I.

    1996-01-01

    The interaction of toroidicity-induced Alfven eigenmodes with thermonuclear alpha particles in the intrinsic stochasticity regime was investigated based on the numerical integration of the equation of motion of alpha particles in the tokamak. The first results obtained for the ITER parameters and moderate wave amplitudes indicate that the stochasticity is highest in the trapped/passing boundary region, where the alpha particles jump stochastically between the two regimes with an appreciable radial excursion (about 0.5 m amplitudes). A similar chaotic behavior was also found for substantially lower energies (about 350 keV). 7 figs., 15 refs

  16. Medium energy inelastic proton-nucleus scattering with spin dependent NN interaction

    International Nuclear Information System (INIS)

    Ahmad, I.; Auger, J.P.

    1981-12-01

    The previously proposed effective profile expansion method for the Glauber multiple scattering model calculation has been extended to the case of proton-nucleus inelastic scattering with spin dependent NN interaction. Using the method which turns out to be computationally simple and of relatively wider applicability, a study of sensitivity of proton-nucleus inelastic scattering calculation to the sometimes neglected momentum transfer dependence of the NN scattering amplitude has been made. We find that the calculated polarization is particularly sensitive in this respect. (author)

  17. TWO-PHOTON PHYSICS IN NUCLEUS-NUCLEUS COLLISIONS AT RHIC

    International Nuclear Information System (INIS)

    Nystrand, J.; Klein, S.

    1998-01-01

    Ultra-relativistic heavy-ions carry strong electromagnetic and nuclear fields. Interactions between these fields in peripheral nucleus-nucleus collisions can probe many interesting physics topics. This presentation will focus on coherent two-photon and photonuclear processes at RHIC. The rates for these interactions will be high. The coherent coupling of all the protons in the nucleus enhances the equivalent photon flux by a factor Z 2 up to an energy of ∼ 3 GeV. The plans for studying coherent interactions with the STAR experiment will be discussed. Experimental techniques for separating signal from background will be presented

  18. Two-photon physics in nucleus-nucleus collisions at RHIC

    International Nuclear Information System (INIS)

    Nystrand, J.; Klein, S.

    1998-01-01

    Ultra-relativistic heavy-ions carry strong electromagnetic and nuclear fields. Interactions between these fields in peripheral nucleus-nucleus collisions can probe many interesting physics topics. This presentation will focus on coherent two-photon and photonuclear processes at RHIC. The rates for these interactions will be high. The coherent coupling of all the protons in the nucleus enhances the equivalent photon flux by a factor Z 2 up to an energy of ∼ 3 GeV. The plans for studying coherent interactions with the STAR experiment will be discussed. Experimental techniques for separating signal from background will be presented

  19. Dynamic. cap alpha. -transfer polarisation potentials and the large angle scattering of /sup 16/O + /sup 28/Si

    Energy Technology Data Exchange (ETDEWEB)

    Hussein, M S; Aleixo, A N; Canto, L F; Carrilho, P; Donangelo, R; Paula, L.S. de

    1987-07-01

    A closed expression is derived for the dynamic ..cap alpha..-transfer polarisation potential for heavy-ion elastic scattering. The back-angle angular distributions for the elastic scattering of /sup 16/O + /sup 28/Si obtained by adding this polarisation potential to the E-18 interaction are shown to be in good agreement with the data if an ..cap alpha..-transfer spectroscopic factor of 0.4 is used.

  20. Inelastic hadron-nucleus interactions at 20 and 37 GeV/c

    International Nuclear Information System (INIS)

    Faessler, M.A.; Lynen, U.; Niewisch, J.; Pietrzyk, B.; Povh, B.; Schroeder, H.; Gugelot, P.C.

    1979-01-01

    The experiment studies charged particle production for π - , K - , and anti p interactions on nuclei at 20 and 37 GeV/c at the CERN SPS. A non-magnetic detector, consisting of CsI(Tl) scintillation and lucite Cerenkov counters, distinguishes between fast particles, mainly pions, and slow particles, mainly nucleons, with a cut at velocity β approximately 0.7. Angular distributions, multiplicity distributions and correlations of slow and fast particles were analysed. It is shown that the measurement of the correlations can provide a critical test for different theoretical models of the hadron-nucleus interaction. At the energies studied so far a systematic deviation from KNO scaling is observed. This gives further support to the 'standard picture' of the hadron-nucleus interaction and it contrasts with predictions of the coherent-tube model. The regularity observed for the angular distribution of fast secondaries as a function of the number of slow particles can only be explained by combining features predicted by different models. (Auth.)

  1. Formation of proton-fragments in hadron-nucleus and nucleus-nucleus collisions at high energies

    International Nuclear Information System (INIS)

    Bazarov, E.Kh.; Olimov, K.; Petrov, V.I.; Lutpullaev, S.L.

    2006-01-01

    Full text: The investigation of production of protons in hadron- and nucleus-nucleus interactions is a key problem allowing one to establish the singularities of dynamics of nuclear interactions. The formation of proton-fragments at high energies of colliding particles proceeds within both the interaction of hadrons with nuclei and in the process of decay of the nucleus or its de-excitation at peripheral interactions. At different stages of interaction of impinging particle with target nucleus, the different mechanisms of formation of proton-fragments: the direct knock-out of intranuclear nucleons in the process of high energy cascade of an initial hadron, intranuclear cascade of produced particles, decay of the excited multi-nucleon fragments and of the thermalized remnant nucleus, and the coalescence of nuclear fragments to the new clusters are realized with the certain probability, connected to the interaction parameters (the interaction energy, the parameter of collision, the intranuclear density, the configuration of Fermi momentum of nucleons and clusters of target nucleus et al.). In its turn, the mechanisms of formation of the final nuclear fragments are closely related to the type of excitation of an initial nucleus. The peripheral interactions proceed at small transfers of the momentum of an impinging particle and represent the wide class of reactions covering the processes from diffractive or coulomb collective excitations of the whole nucleus to the direct quasi-elastic knock-out of the separate nucleons. Non-peripheral interactions are caused by comparatively high local transfers of momentum to the intranuclear clusters allowing the development of intranuclear cascade and the asymmetric redistribution of energy of an impinging particle. The central collisions causing the full decay of nucleus on nucleons or few-nucleon fragments, are the limiting case of the maximal development of the intranuclear cascade. The interaction of the initial particles with

  2. Experimental study of time-reversal invariance in neutron-nucleus interactions

    International Nuclear Information System (INIS)

    Shaparov, E.I.; Shimizu, H.M.

    1996-01-01

    Experimental approaches for the test of time-reversal invariance in neutron-nucleus interactions are reviewed. Possible transmission experiments with polarized neutron beams and polarized or aligned targets are discussed as well as neutron capture experiments with unpolarized resonance neutrons. 102 refs., 13 figs., 3 tabs

  3. A cluster expansion for bound three-alpha particles as a three-body problem

    International Nuclear Information System (INIS)

    Osman, A.

    1981-08-01

    A three-body model is proposed to study the nuclear bound states. The nucleus is described as a bound state of three clusters. A cluster expansion is introduced for the three cluster bound state problem. The present integral equations are treated by simple approximate solutions, which lead to effective potentials by using the present cluster expansion. The 12 C nucleus is described as a three-alpha particle bound state. The binding energy of 12 C is calculated numerically using the present cluster expansion as bound three-alpha clusters. The present three-body cluster expansion calculations are very near to the exact three-body calculations using separable potentials. The present theoretical calculations are in good agreement with the experimental measurements. (author)

  4. Off-shell sensitivity, repulsive correlations and the pion-nucleus optical potential

    Energy Technology Data Exchange (ETDEWEB)

    Keister, B D [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

    1977-07-01

    Repulsive nucleon-nucleon correlations tend to reduce the dependence of pion-nucleus elastic scattering upon the off-shell pion-nucleon dynamics. However, optical potential calculations can in practice be quite sensitive to the particular choice of off-shell model parameters. It is argued that this sensitivity results from the nature of the optical potential as a one-body operator which introduces extra off-shell dependence not found in physical many-body process itself. Thus, one must be very careful in any attempt to extract correlation or off-shell information, or to predict pion-nucleus phase shifts, by means of an optical potential theory. Results of model calculations are presented for purposes of illustration.

  5. Pion interactions with light nuclei and applications to radiotherapy

    International Nuclear Information System (INIS)

    Brenner, D.J.

    1979-02-01

    In the light of the current interest in negative pion radiotherapy particle spectra have been obtained after negative pion absorption in oxygen. Using a multiple foil activation technique, measurements were made of neutron spectra from the pion interactions and also from background sources from which it appears that the technique is a potentially useful tool for routine dosimetry. Theoretical predictions are made of the energy spectra of particles emitted after stopped pion absorption on oxygen based on an alpha cluster model and using a plane-wave impulse approximation. A method of considering residual interactions with the nucleus is described which has the potential to treat the low energy particles and also final channels not expected as a result of a single interaction. (UK)

  6. Coincidence study of alpha particle fragmentation at E/sub alpha/ = 140 MeV

    International Nuclear Information System (INIS)

    Koontz, R.W.

    1980-01-01

    Results of an experimental study of the interaction of 140 MeV alpha particles with 90 Zr nuclei resulting in fragmentation of the alpha particle are reported. The experimental observations of the study are analyzed and are found to show that alpha particle breakup reactions leading to at least 4-body final states, composed of two charged alpha particle fragments, contribute significantly to the singles yield of charged fragments observed at a fixed forward angle. The conclusions are based on coincidence measurements where one charged fragment is detected at a small forward angle which remains fixed, while the second charged fragment is detected at a series of coplanar secondary angles. The largest coincidence charged particle yield for the multiparticle final state events results from 90 Zr(α,pp)X reactions, where both of the measured protons have energy distributions similar to the proton singles energy distributions. The second largest observed coincidence yield involving two charged fragments arises from 90 Zr(α,pd)X reactions, where the p and d fragments, as in the 90 Zr(α,pp)X reactions also have energy distribution similar to the singles energy distributions. Analysis of additional measurements, where alpha particle fragments at the fixed angle are detected in coincidence with evaporation and nonequilibrium particles at many coplanar angles, show that the alpha particle fragmentation reactions are also generally associated with large energy transfer to the target nucleus. A multiple scattering model of the fragmentation reaction is employed, in conjunction with the experimental observations, to estimate the cross sections for alpha particle fragmentation into multi-particle final states resulting in n, 2n, p, pp, d, dn, dp, t and 3 He fragments. The estimated total cross section for all fragmentation reactions is 755 mb or approximately 38% of the total reaction cross section for 140 MeV alpha particle interactions with 90 Zr

  7. Changes in estrogen receptor-alpha and -beta in the infundibular nucleus of the human hypothalamus are related to the occurrence of Alzheimer's disease neuropathology

    NARCIS (Netherlands)

    Hestiantoro, Andon; Swaab, Dick F.

    2004-01-01

    The expression of estrogen receptor (ER)alpha and -beta in the infundibular nucleus of the hypothalamus was studied immunocytochemically in 28 control subjects and 14 patients with Alzheimer's disease (AD). A shift was found from more nuclear staining of ERalpha in young female controls to more

  8. Theoretical interpretation of medium energy nucleon nucleus inelastic scattering

    International Nuclear Information System (INIS)

    Lagrange, Christian

    1970-06-01

    A theoretical study is made of the medium energy nucleon-nucleus inelastic scattering (direct interaction), by applying the distorted wave Born approximation such as can be deduced from the paired equation method. It is applied to the interpretation of the inelastic scattering of 12 MeV protons by 63 Cu; this leads us to make use of different sets of wave functions to describe the various states of the target nucleus. We analyze the nature of these states and the shape of the nucleon-nucleus interaction potential, and we compare the results with those obtained from other theoretical and experimental work. (author) [fr

  9. Dynamics of hadron-nucleus interactions

    International Nuclear Information System (INIS)

    Wallace, S.J.

    1981-07-01

    Recent progress in diffraction theory shows that proton-nucleus scattering at nonforward angles is dominated by the interference of waves from two or more bright spots. Analytic formulas based on asymptotic theories of diffraction yield valuable new insights into the scattering and these formulas can be readily extended to illuminate the role of dynamical ingredients, i.e., the nucleon-nucleon amplitudes. The governing parameters of the diffraction and some direct connections between the observed cross sections and the input dynamics are reviewed. New information regarding the nucleon-nucleon parameters based on recent phase shift analyses show some systematic differences from the effective NN amplitudes which produce fits to proton-nucleus diffraction data. Recent progress in understanding the role of Δ-isobars in proton-nucleus dynamics is reviewed. 126 references

  10. Clonidine, an alpha2-receptor agonist, diminishes GABAergic neurotransmission to cardiac vagal neurons in the nucleus ambiguus.

    Science.gov (United States)

    Philbin, Kerry E; Bateman, Ryan J; Mendelowitz, David

    2010-08-06

    In hypertension, there is an autonomic imbalance in which sympathetic activity dominates over parasympathetic control. Parasympathetic activity to the heart originates from cardiac vagal neurons located in the nucleus ambiguus. Presympathetic neurons that project to sympathetic neurons in the spinal cord are located in the ventral brainstem in close proximity to cardiac vagal neurons, and many of these presympathetic neurons are catecholaminergic. In addition to their projection to the spinal cord, many of these presympathetic neurons have axon collaterals that arborize into neighboring cardiorespiratory locations and likely release norepinephrine onto nearby neurons. Activation of alpha(2)-adrenergic receptors in the central nervous system evokes a diverse range of physiological effects, including reducing blood pressure. This study tests whether clonidine, an alpha(2)-adrenergic receptor agonist, alters excitatory glutamatergic, and/or inhibitory GABAergic or glycinergic synaptic neurotransmission to cardiac vagal neurons in the nucleus ambiguus. Cardiac vagal neurons were identified in an in vitro brainstem slice preparation, and synaptic events were recording using whole cell voltage clamp methodologies. Clonidine significantly inhibited GABAergic neurotransmission but had no effect on glycinergic or glutamatergic pathways to cardiac vagal neurons. This diminished inhibitory GABAergic neurotransmission to cardiac vagal neurons would increase parasympathetic activity to the heart, decreasing heart rate and blood pressure. The results presented here provide a cellular substrate for the clinical use of clonidine as a treatment for hypertension as well as a role in alleviating posttraumatic stress disorder by evoking an increase in parasympathetic cardiac vagal activity, and a decrease in heart rate and blood pressure. Copyright 2010 Elsevier B.V. All rights reserved.

  11. The host-dependent interaction of alpha-importins with influenza PB2 polymerase subunit is required for virus RNA replication.

    Directory of Open Access Journals (Sweden)

    Patricia Resa-Infante

    Full Text Available The influenza virus polymerase is formed by the PB1, PB2 and PA subunits and is required for virus transcription and replication in the nucleus of infected cells. As PB2 is a relevant host-range determinant we expressed a TAP-tagged PB2 in human cells and isolated intracellular complexes. Alpha-importin was identified as a PB2-associated factor by proteomic analyses. To study the relevance of this interaction for virus replication we mutated the PB2 NLS and analysed the phenotype of mutant subunits, polymerase complexes and RNPs. While mutant PB2 proteins showed reduced nuclear accumulation, they formed polymerase complexes normally when co expressed with PB1 and PA. However, mutant RNPs generated with a viral CAT replicon showed up to hundred-fold reduced CAT accumulation. Rescue of nuclear localisation of mutant PB2 by insertion of an additional SV40 TAg-derived NLS did not revert the mutant phenotype of RNPs. Furthermore, determination of recombinant RNP accumulation in vivo indicated that PB2 NLS mutations drastically reduced virus RNA replication. These results indicate that, above and beyond its role in nuclear accumulation, PB2 interaction with alpha-importins is required for virus RNA replication. To ascertain whether PB2-alpha-importin binding could contribute to the adaptation of H5N1 avian viruses to man, their association in vivo was determined. Human alpha importin isoforms associated efficiently to PB2 protein of an H3N2 human virus but bound to diminished and variable extents to PB2 from H5N1 avian or human strains, suggesting that the function of alpha importin during RNA replication is important for the adaptation of avian viruses to the human host.

  12. Spectroscopic study on the interaction of Bacillus subtilis {alpha}-amylase with cetyltrimethylammonium bromide

    Energy Technology Data Exchange (ETDEWEB)

    Omidyan, R., E-mail: r.omidyan@sci.ui.ac.i [Department of Chemistry, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Kazemi, S.H. [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Bordbar, A.K. [Department of Chemistry, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Zaynalpour, S. [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of)

    2011-06-15

    The interaction between {alpha}-amylase from Bacillus subtilis and cetyltrimethylammonium bromide (CTAB) has been investigated at various temperature conditions using fluorescence and circular dichroism (CD) spectroscopic methods. Fluorescence data revealed that the fluorescence quenching of {alpha}-amylase by CTAB is the result of complex formation between CTAB and {alpha}-amylase. The thermodynamic analysis on the binding interaction data shows that the interactions are strongly exothermic ({Delta}H{sup o}=-17.92 kJ mol{sup -1}) accompanied with increase in entropy ({Delta}S{sup o} between 109 to 135 J mol{sup -1} K{sup -1}). Thus the binding of CTAB to {alpha}-amylase is both enthalpic and entropic driven, which represent the predominate role of both electrostatic and hydrophobic interactions in complex formation process. The values of 2.17x10{sup -3} M{sup -1} and 1.30 have been obtained from associative binding constant (K{sub a}) and stoichiometry of binding number (n), from analysis of fluorescence data, respectively. Circular dichroism spectra showed the substantial conformational changes in secondary structure of {alpha}-amylase due to binding of CTAB, which represents the complete destruction of both secondary and tertiary structure of {alpha}-amylase by CTAB. - Research highlights: {yields} The Fluorescence quenching effect of {alpha}-amylase by CTAB is a consequence of formation {alpha}-amylase-CTAB complex. {yields} The {alpha}-helical analyzing from the CD spectra in the various concentration of CTAB shows strongly deformation of {alpha}-amylase. {yields} Thermodynamic analysis of quenching verify that the interactions are both enthalpy and entropic driven.

  13. An X11alpha/FSBP complex represses transcription of the GSK3beta gene promoter.

    LENUS (Irish Health Repository)

    Lau, Kwok-Fai

    2010-08-04

    X11alpha is a neuronal adaptor protein that interacts with the amyloid precursor protein (APP) through a centrally located phosphotyrosine binding domain to inhibit the production of Abeta peptide that is deposited in Alzheimer\\'s disease brains. X11alpha also contains two C-terminal postsynaptic density-95, large discs, zona occludens 1 (PDZ) domains, and we show here that through its PDZ domains, X11alpha interacts with a novel transcription factor, fibrinogen silencer binding protein. Moreover, we show that an X11alpha\\/fibrinogen silencer binding protein complex signals to the nucleus to repress glycogen synthase kinase-3beta promoter activity. Glycogen synthase kinase-3beta is a favoured candidate kinase for phosphorylating tau in Alzheimer\\'s disease. Our findings show a new function for X11alpha that may impact on Alzheimer\\'s disease pathogenesis.

  14. The Baryon Production and Baryon Number Transfer in Hadron-Hadron, Hadron-Nucleus and Nucleus-Nucleus Collisions

    International Nuclear Information System (INIS)

    Szymanski, P.

    2006-09-01

    This work concerns soft hadronic interactions which in the Standard Model carry most of the observable cross-section but are not amenable to quantitative predictions due to the very nature of the QCD (Theory of Strong Interactions). In the low momentum transfer region the evolving coupling constant caused perturbation theory to break down. In this situation better experimental understanding of the physics phenomena is needed. One aspect of the soft hadronic interactions will be discussed in this work: transfer of the baryon number from the initial to the final state of the interaction. The past experimental knowledge on this process is presented, reasons for its unsatisfactory status are discussed and condition necessary for improvement are outlined: that is experimental apparatus with superior performance over the full range of available interactions: hadron-hadron collision, hadron-nucleus and nucleus-nucleus interactions. A consistent model-independent picture of the baryon number transfer process emerging from the data on the full range of interactions is shown. It offers serious challenge to theory to provide quantitative and detailed explanation of the measurements. (author)

  15. Associated charm production in neutrino-nucleus interactions

    International Nuclear Information System (INIS)

    Kayis-Topaksu, A.; Oenenguet, G.; van Dantzig, R.; de Jong, M.; Oldeman, R.G.C.; Gueler, M.; Koese, U.; Tolun, P.; Catanesi, M.G.; Muciaccia, M.T.; Winter, K.; Van de Vyver, B.; Vilain, P.; Wilquet, G.; Saitta, B.; Di Capua, E.; Ogawa, S.; Shibuya, H.; Hristova, I.R.; Kawamura, T.; Kolev, D.; Meinhard, H.; Panman, J.; Tsenov, R.; Uiterwijk, J.W.E.; Rozanov, A.; Zucchelli, P.; Goldberg, J.; Chikawa, M.; Song, J.S.; Yoon, C.S.; Kodama, K.; Ushida, N.; Aoki, S.; Hara, T.; Delbar, T.; Favart, D.; Gregoire, G.; Kalinin, S.; Makhlioueva, I.; Artamonov, A.; Khovansky, V.; Shamanov, V.; Tsukerman, I.; Gorbunov, P.; Bruski, N.; Frekers, D.; Hoshino, K.; Kawada, J.; Komatsu, M.; Miyanishi, M.; Nakamura, M.; Nakano, T.; Narita, K.; Niu, K.; Niwa, K.; Nonaka, N.; Sato, O.; Toshito, T.; Buontempo, S.; Cocco, A.G.; D'Ambrosio, N.; De Lellis, G.; De Rosa, G.; Di Capua, F.; Fiorillo, G.; Marotta, A.; Migliozzi, P.; Scotto Lavina, L.; Strolin, P.; Tioukov, V.; Okusawa, T.; Dore, U.; Loverre, P.F.; Ludovici, L.; Rosa, G.; Santacesaria, R.; Satta, A.; Spada, F.R.; Barbuto, E.; Bozza, C.; Grella, G.; Romano, G.; Sirignano, C.; Sorrentino, S.; Sato, Y.; Tezuka, I.

    2007-01-01

    In this paper a search for associated charm production both in neutral and charged current ν-nucleus interactions is presented. The improvement of automatic scanning systems in the CHORUS experiment allows an efficient search to be performed in emulsion for short-lived particles. Hence a search for rare processes, like the associated charm production, becomes possible through the observation of the double charm-decay topology with a very low background. About 130000 ν interactions located in the emulsion target have been analysed. Three events with two charm decays have been observed in the neutral-current sample with an estimated background of 0.18±0.05. The relative rate of the associated charm cross-section in deep inelastic ν interactions, σ(c anti cν)/σ NC DIS =(3.62 +2.95 -2.42 (stat)±0.54(syst)) x 10 -3 has been measured. One event with two charm decays has been observed in charged-current ν μ interactions with an estimated background of 0.18±0.06 and the upper limit on associated charm production in charged-current interactions at 90% C.L. has been found to be σ(c anti cμ - )/σ CC -4 . (orig.)

  16. Functional characterisation of the human alpha1 glycine receptor in a fluorescence-based membrane potential assay

    DEFF Research Database (Denmark)

    Jensen, Anders A.; Kristiansen, Uffe

    2004-01-01

    In the present study, we have created a stable HEK293 cell line expressing the human homomeric alpha1 glycine receptor (GlyR) and characterised its functional pharmacology in a conventional patch-clamp assay and in the FLIPR Membrane Potential (FMP) assay, a fluorescence-based high throughput scr...... not be suited for sophisticated studies of GlyR pharmacology and kinetics. However, the assay offers several advantages in studies of ligand-receptor interactions. Furthermore, the assay could be highly useful in the search for structurally novel ligands acting at GlyRs.......In the present study, we have created a stable HEK293 cell line expressing the human homomeric alpha1 glycine receptor (GlyR) and characterised its functional pharmacology in a conventional patch-clamp assay and in the FLIPR Membrane Potential (FMP) assay, a fluorescence-based high throughput...... ion did not appear to potentiate GlyR function at lower concentrations. Analogously, whereas pregnenolone sulphate inhibited alpha1 GlyR function, the potentiation of alpha1 GlyR by pregnenolone in electrophysiological studies could not be reproduced in the assay. In conclusion, the FMP assay may...

  17. Constraints on the α+nucleus optical-model potential via α-induced reaction studies on 108Cd

    Directory of Open Access Journals (Sweden)

    P. Scholz

    2016-10-01

    Full Text Available A big part in understanding the nucleosynthesis of heavy nuclei is a proper description of the effective interaction between an α-particle and a target nucleus. Information about the so-called α+nucleus optical-model potential is achieved by precise cross-section measurements at sub-Coulomb energies aiming to constrain the theoretical models for the nuclear physics input-parameters. The cross sections of the 108Cd(α,γ and 108Cd(α,n reaction have been measured for the first time close to the astrophysically relevant energy region via the in-beam method at the high-efficiency γ-ray spectrometer HORUS and via the activation technique at the Cologne Clover Counting Setup at the Institute for Nuclear Physics in Cologne, Germany. Comparisons between experimental results and theoretical predictions calculated in the scope of the Hauser–Feshbach statistical model confirm the need for a exponentially decreasing imaginary part of the potential. Moreover, it is shown that the results presented here together with already published data indicate that a systematic investigation of the real part of the potential could help to further improve the understanding of reactions involving α-particles.

  18. The correlation between the transverse polarization and transverse momentum of lambda produced in relativistic nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Ye Yunxiu; Zhou Xin; Ji Gang; Su Shufang; Zhu Guohuai

    1996-01-01

    The transverse polarization of lambda produced in relativistic nucleus-nucleus collisions is determined. The effect from the interaction between spin moment and magnetic field is corrected. The near zero transverse polarization and non-correlation between transverse polarization and transverse momentum are obtained and compared to ones obtained from the nucleus-nucleus interactions at lower energies. This comparison shows that the production mechanism of lambdas in the relativistic nucleus-nucleus collisions is different from one in the nucleus-nucleus reactions at lower energies

  19. Cross-sections for neutral-current neutrino-nucleus interactions applications for $^{12}$C and $^{16}$O

    CERN Document Server

    Jachowicz, N; Heyde, Kris L G; Ryckebusch, J

    1999-01-01

    We calculate cross sections for neutral current quasi-elastic neutrino-nucleus scattering within a continuum RPA model, based on a Green's function approach. As residual interaction a Skyrme force is used. The unperturbed single particle wave functions are generated using either a Woods-Saxon potential or a Hartree-Fock calculation. These calculations have interesting applications. Neutrinos play an important role in supernova nucleosynthesis. To obtain more information about these processes, cross sections are folded with a Fermi-Dirac distribution with temperatures of approximately 10$^9$ K.

  20. Experimental search for compression phenomena in fast nucleus--nucleus collisions

    International Nuclear Information System (INIS)

    Schopper, E.; Baumgardt, H.G.; Obst, E.

    1977-01-01

    The occurrence of compression phenomena and shock waves, connected with the increase of the density of the nuclear matter during the interpenetration of two fast nuclei, are discussed. Current experiments dealing with this problem are reviewed. Before considering the mechanism of the interpenetration of two fast nuclei it may be useful to look at more simple situations, i.e., proton-proton interactions, then to envelop them with nuclear matter, considering proton-nucleus interactions. Only very general features are described, which may give suggestions for the understanding of the nucleus-nucleus impact

  1. Astrocytes potentiate GABAergic transmission in the thalamic reticular nucleus via endozepine signaling.

    Science.gov (United States)

    Christian, Catherine A; Huguenard, John R

    2013-12-10

    Emerging evidence indicates that diazepam-binding inhibitor (DBI) mediates an endogenous benzodiazepine-mimicking (endozepine) effect on synaptic inhibition in the thalamic reticular nucleus (nRT). Here we demonstrate that DBI peptide colocalizes with both astrocytic and neuronal markers in mouse nRT, and investigate the role of astrocytic function in endozepine modulation in this nucleus by testing the effects of the gliotoxin fluorocitrate (FC) on synaptic inhibition and endozepine signaling in the nRT using patch-clamp recordings. FC treatment reduced the effective inhibitory charge of GABAA receptor (GABAAR)-mediated spontaneous inhibitory postsynaptic currents in WT mice, indicating that astrocytes enhance GABAAR responses in the nRT. This effect was abolished by both a point mutation that inhibits classical benzodiazepine binding to GABAARs containing the α3 subunit (predominant in the nRT) and a chromosomal deletion that removes the Dbi gene. Thus, astrocytes are required for positive allosteric modulation via the α3 subunit benzodiazepine-binding site by DBI peptide family endozepines. Outside-out sniffer patches pulled from neurons in the adjacent ventrobasal nucleus, which does not contain endozepines, show a potentiated response to laser photostimulation of caged GABA when placed in the nRT. FC treatment blocked the nRT-dependent potentiation of this response, as did the benzodiazepine site antagonist flumazenil. When sniffer patches were placed in the ventrobasal nucleus, however, subsequent treatment with FC led to potentiation of the uncaged GABA response, suggesting nucleus-specific roles for thalamic astrocytes in regulating inhibition. Taken together, these results suggest that astrocytes are required for endozepine actions in the nRT, and as such can be positive modulators of synaptic inhibition.

  2. Alpha decay studies on Po isotopes using different versions of nuclear potentials

    Energy Technology Data Exchange (ETDEWEB)

    Santhosh, K.P.; Sukumaran, Indu [Kannur University, School of Pure and Applied Physics, Payyanur, Kerala (India)

    2017-12-15

    The alpha decays from {sup 186-224}Po isotopes have been studied using 25 different versions of nuclear potentials so as to select a suitable nuclear potential for alpha decay studies. The computed standard deviation of the calculated half-lives in comparison with the experimental data suggested that proximity 2003-I is the apt form of nuclear potential for alpha decay studies as it possesses the least standard deviation, σ = 0.620. Among the different proximity potentials, proximity 1966 (σ = 0.630) and proximity 1977 (σ = 0.636), are also found to work well in alpha decay studies with low deviation. Among other versions of nuclear potentials (other than proximity potentials), Bass 1980 is suggested to be a significant form of nuclear potential because of its good predictive power. However, while the other forms of potentials are able to reproduce the experimental data to some extent, these potentials cannot be considered as apposite potentials for alpha decay studies in their present form. Since the experimental correlation of the models is noticed to be satisfying, the alpha decay half-lives of certain Po isotopes that are not detected experimentally yet have been predicted. (orig.)

  3. Mapping of nuclear import signal and importin {alpha}3 binding regions of 52K protein of bovine adenovirus-3

    Energy Technology Data Exchange (ETDEWEB)

    Paterson, Carolyn P.; Ayalew, Lisanework E. [Vaccine and Infectious Disease Organization-International Vaccine Center (VIDO-InterVac), University of Saskatchewan, Saskatoon, SK S7N 5E3 Canada (Canada); Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK S7N 5E3 S7N 5B4 Canada (Canada); Tikoo, Suresh K., E-mail: suresh.tik@usask.ca [Vaccine and Infectious Disease Organization-International Vaccine Center (VIDO-InterVac), University of Saskatchewan, Saskatoon, SK S7N 5E3 Canada (Canada); Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK S7N 5E3 S7N 5B4 Canada (Canada); School of Public Health, University of Saskatchewan, Saskatoon, SK S7N 5E5 Canada (Canada)

    2012-10-10

    The L1 region of bovine adenovirus (BAdV)-3 encodes a non-structural protein designated 52K. Anti-52K serum detected a protein of 40 kDa, which localized to the nucleus but not to the nucleolus in BAdV-3-infected or transfected cells. Analysis of mutant 52K proteins suggested that three basic residues ({sup 105}RKR{sup 107}) of the identified domain (amino acids {sup 102}GMPRKRVLT{sup 110}) are essential for nuclear localization of 52K. The nuclear import of a GST-52K fusion protein utilizes the classical importin {alpha}/{beta}-dependent nuclear transport pathway. The 52K protein is preferentially bound to the cellular nuclear import receptor importin {alpha}3. Although deletion of amino acid 102-110 is sufficient to abrogate the nuclear localization of 52K, amino acid 90-133 are required for interaction with importin-{alpha}3 and localizing a cytoplasmic protein to the nucleus. These results suggest that 52K contains a bipartite NLS, which preferentially utilize an importin {alpha}3 nuclear import receptor-mediated pathway to transport 52K to the nucleus.

  4. Applying the elastic model for various nucleus-nucleus fusion

    International Nuclear Information System (INIS)

    HASSAN, G.S.; RAGAB, H.S.; SEDDEEK, M.K.

    2000-01-01

    The Elastic Model of two free parameters m,d given by Scalia has been used for wider energy regions to fit the available experimental data for potential barriers and cross sections. In order to generalize Scalia's formula in both sub- and above-barrier regions, we calculated m, d for pairs rather than those given by Scalia and compared the calculated cross sections with the experimental data. This makes a generalization of the Elastic Model in describing fusion process. On the other hand, Scalia's range of interacting systems was 24 ≤ A ≤194 where A is the compound nucleus mass number. Our extension of that model includes an example of the pairs of A larger than his final limit aiming to make it as a general formula for any type of reactants: light, intermediate or heavy systems. A significant point is the comparison of Elastic Model calculations with the well known methods studying complete fusion and compound nucleus formation, namely with the resultants of using Proximity potential with either Sharp or Smooth cut-off approximations

  5. AgRP and NPY Expression in the Human Hypothalamic Infundibular Nucleus Correlate with Body Mass Index, Whereas Changes in alpha MSH Are Related to Type 2 Diabetes

    NARCIS (Netherlands)

    Alkemade, Anneke; Yi, Chun-Xia; Pei, Lei; Harakalova, Magdalena; Swaab, Dick F.; la Fleur, Susanne E.; Fliers, Eric; Kalsbeek, Andries

    2012-01-01

    Context: Rodent data show that altered hypothalamic signaling contributes to the development of obesity and insulin resistance. Objective: To determine differences in hypothalamic expression levels of neuropeptide Y (NPY), agouti-related peptide (AgRP), and alpha MSH in the infundibular nucleus, the

  6. Shell and isotopic effects in neutron interaction with nuclei. [Optical model and nucleus asymmetry correlations

    Energy Technology Data Exchange (ETDEWEB)

    Pasechnik, M V

    1978-01-01

    Major results of investigations into the shell structure of deformed nuclei with the number of neutrons of approximately 100, as well as new isotopic effects in the inelastic scattering of fast neutrons with nuclei are reported. The experiments conducted at the WWR-M research reactor have shown a substantial dependence of the nuclear excited energy-level density on the mass number and the number of neutrons. The fact resulted in a conclusion that the deformed nuclei possess filled shells, that was an incentive to revise the whole nuclear shell concept. In particular it was established that the property of magicity rests not only on the sphericity of nuclei but it may be also observed in strongly deformed nuclei. The isotope-spin dependence of the nuclear potential was studied at the AG-5 pulse electrostatic generator. The parameters of the potential were determined by comparing the experimental data on inelastic scattering and polarization of fast neutrons by nuclei from /sup 48/Ti to /sup 209/Bi with the calculations in terms of the optical model. Simple correlations were established between the optical potential and the nucleus asymmetry parameter ..cap alpha..=N-Z/A in wide ranges of mass numbers and neutron energy.

  7. Experimental studies of pion-nucleus interactions at intermediate energies

    International Nuclear Information System (INIS)

    1992-01-01

    This report summarizes investigations of various pion-nucleus interactions and nucleon-nucleus charge-exchange reactions. The work was carried out with the LAMPF accelerator at the Los Alamos National Laboratory and the cyclotrons at the Paul Scherrer Institute (PSI) near Zurich, Switzerland, and at Indiana University (IUCF), as a collaborative effort among several laboratories and universities. The experimental activity at LAMPF involved measurements of new data on pion double-charge-exchange scattering, some initial work on a new Neutral Meson Spectrometer system, a search for deeply-bound pionic atoms, measurements of elastic scattering, and studies of the (n,p) reaction on various nuclei. At PSI measurements of pion quasielastic scattering were carried out, with detection of the recoil proton. Work on the analysis of data from a previous experiment at PSI on pion absorption in nuclei was continued. This experiment involved using a detector system that covered nearly the full solid angle

  8. Similarity of multi-fragmentation of residual nucleus created in nucleus-nucleus interactions at high energies

    International Nuclear Information System (INIS)

    Abdel-Hafiez, A.; Chernyavski, M.M.; Orlova, G.I.; Gulamov, K.G.; Navotny, V.SH.; Uzhinskii, V.V.

    2000-01-01

    Experimental data on multi-fragmentation of residual krypton nuclei created in the interactions of the krypton nuclei with photoemulsion nuclei ut energy of 0.9 GeV per nucleon are presented in a comparison with the analogous data on fragmentation of gold residual nuclei at the energy of 10.7 GeV/nucleon. It is shown for the first time that there are two regimes of nuclear multifragmentation: the former is when less than one-half of nucleons of projectile nucleus are knocked out, the later is when more than one-half of nucleons are knocked out. Residual nuclei with closed masses created at different reactions are fragmenting practically simultaneously when more than one-half of nucleons of original nuclei are knocked out. The evidence of existence of a radial flow of the spectator fragment at the decay of residual krypton nuclei is found

  9. Pion production in nucleus--nucleus collisions

    International Nuclear Information System (INIS)

    Schroeder, L.S.

    1975-06-01

    Current work on pion production in high-energy nucleus-nucleus collisions is reviewed. The majority of existing data are of the inclusive variety in which a single final state pion is detected. Experimental data are compared and their possible contributions to obtaining new information on nuclear structure is discussed. Various models which attempt to explain the observed single-inclusive-pion spectra either on the basis of a nucleon-nucleus interaction in which Fermi motion is included or on some type of cooperative model are examined. Other areas of interest involving pion production include tests of charge symmetry and pion multiplicities. (9 figures, 1 table) (U.S.)

  10. Differences Between a Single- and a Double-Folding Nucleus-9Be Optical Potential

    International Nuclear Information System (INIS)

    Bonaccorso, A.; Carstoiu, F.; Charity, R. J.; Kumar, R.; Salvioni, G.

    2016-01-01

    We have recently constructed two very successful n- 9 Be optical potentials (Bonaccorso and Charity in Phys Rev C89:024619, 2014). One by the Dispersive Optical Model (DOM) method and the other (AB) fully phenomenological. The two potentials have strong surface terms in common for both the real and the imaginary parts. This feature makes them particularly suitable to build a single-folded (light-) nucleus- 9 Be optical potential by using ab-initio projectile densities such as those obtained with the VMC method. On the other hand, a VMC density together with experimental nucleon–nucleon cross-sections can be used also to obtain a neutron and/or proton- 9 Be imaginary folding potential. We will use here an ab-initio VMC density to obtain both a n- 9 Be single-folded potential and a nucleus-nucleus double-folded potential. In this work we report on the cases of 8 B, 8 Li and 8 C projectiles. Our approach could be the basis for a systematic study of optical potentials for light exotic nuclei scattering on such light targets. Some of the projectiles studied are cores of other exotic nuclei for which neutron knockout has been used to extract spectroscopic information. For those cases, our study will serve to make a quantitative assessment of the core-target part of the reaction description, in particular its localization. (author)

  11. Studies of the nucleon-nucleus and the nucleon-nucleon interactions using polarized neutron beams

    International Nuclear Information System (INIS)

    Walter, R.L.; Howell, C.R.; Tornow, W.

    1988-01-01

    The results o four scattering measurements using beams of polarized neutrons are described. Results for the analyzing power A y (θ) for elastic scattering of neutrons from protons and deuterons are compared to calculations based on the Paris and the Bonn nucleon-nucleon interactions. Deficiencies particularly in the Bonn model are indicated. A nucleon-nucleus potential is derived from σ(θ) and A y (θ) data for n + 28 Si and p + 28 Si and the Coulomb correction terms are derived according to two approaches. A Fourier-Bessel expansion is used to investigate the form factors of the terms of the n + 208 Pb potential which are necessary to describe σ(θ) and A y (θ) data from 6 to 10 MeV. The nature of the spin-orbit term is also presented. (author)

  12. Experimental studies of nucleon-nucleon and pion-nucleus interactions at intermediate energies

    International Nuclear Information System (INIS)

    1990-01-01

    This report summarizes the work on experimental research in intermediate energy nuclear and particle physics carried out by New Mexico State University in 1988--91. Most of these studies have involved investigations of neutron-proton and pion-nucleus interactions. The neutron-proton research is part of a program of studies of interactions between polarized nucleons that we have been involved with for more than ten years. Its purpose has been to help complete the determination of the full set of ten complex nucleon-nucleon amplitudes at energies up to 800 MeV, as well as to continue investigating the possibility of the existence of dibaryon resonances. The give complex isospin-one amplitudes have been fairly well determined, partly as a result of this work. Our work in this period has involved measurements and analysis of data on elastic scattering and total cross sections for polarized neutrons on polarized protons. The pion-nucleus research continues our studies of this interaction in regions where it has not been well explored. One set of experiments includes studies of pion elastic and double-charge-exchange scattering at energies between 300 and 550 MeV, where our data is unique. Another involves elastic and single-charge-exchange scattering of pions from polarized nuclear targets, a new field of research which will give the first extensive set of information on spin-dependent pion-nucleus amplitudes. Still another involves the first set of detailed studies of the kinematic correlations among particles emitted following pion absorption in nuclei

  13. Production of high energy density in anti N-nucleus interactions

    International Nuclear Information System (INIS)

    Gibbs, W.R.

    1986-01-01

    The results of an investigation of anti p- (and to a lesser extent) anti d- nucleus interactions are reported. The technique involves following the classical production and propagation of mesons (π,K + , K 0 , K - , K 0 , K*, eta, ω, phi) and baryons (N,Λ,Σ) in nuclei after antiparticle annihilation. It is found that small regions of the nucleus can be raised to sufficiently high energy densities that some predictions of a quark-gluon phase transition can be tested with the use of energetic antiprotons (5-10 GeV/c). the strangeness signal is examined and compared with the amount of strangeness produced in a recent experiment with 4 GeV/c incident antiprotons. A general expression is given for the total amount of strangeness produced which is invariant under intranuclear strangeness exchange reactions. 7 refs., 6 figs., 3 tabs

  14. AlphaSpace: Fragment-Centric Topographical Mapping To Target Protein–Protein Interaction Interfaces

    Science.gov (United States)

    2016-01-01

    Inhibition of protein–protein interactions (PPIs) is emerging as a promising therapeutic strategy despite the difficulty in targeting such interfaces with drug-like small molecules. PPIs generally feature large and flat binding surfaces as compared to typical drug targets. These features pose a challenge for structural characterization of the surface using geometry-based pocket-detection methods. An attractive mapping strategy—that builds on the principles of fragment-based drug discovery (FBDD)—is to detect the fragment-centric modularity at the protein surface and then characterize the large PPI interface as a set of localized, fragment-targetable interaction regions. Here, we introduce AlphaSpace, a computational analysis tool designed for fragment-centric topographical mapping (FCTM) of PPI interfaces. Our approach uses the alpha sphere construct, a geometric feature of a protein’s Voronoi diagram, to map out concave interaction space at the protein surface. We introduce two new features—alpha-atom and alpha-space—and the concept of the alpha-atom/alpha-space pair to rank pockets for fragment-targetability and to facilitate the evaluation of pocket/fragment complementarity. The resulting high-resolution interfacial map of targetable pocket space can be used to guide the rational design and optimization of small molecule or biomimetic PPI inhibitors. PMID:26225450

  15. The network of causal interactions for beta oscillations in the pedunculopontine nucleus, primary motor cortex, and subthalamic nucleus of walking parkinsonian rats.

    Science.gov (United States)

    Li, Min; Zhou, Ming; Wen, Peng; Wang, Qiang; Yang, Yong; Xiao, Hu; Xie, Zhengyuan; Li, Xing; Wang, Ning; Wang, Jinyan; Luo, Fei; Chang, Jingyu; Zhang, Wangming

    2016-08-01

    Oscillatory activity has been well-studied in many structures within cortico-basal ganglia circuits, but it is not well understood within the pedunculopontine nucleus (PPN), which was recently introduced as a potential target for the treatment of gait and postural impairments in advanced stages of Parkinson's disease (PD). To investigate oscillatory activity in the PPN and its relationship with oscillatory activity in cortico-basal ganglia circuits, we simultaneously recorded local field potentials in the PPN, primary motor cortex (M1), and subthalamic nucleus (STN) of 6-hydroxydopamine (6-OHDA)-induced hemiparkinsonian rats during resting and walking. After analysis of power spectral density, coherence, and partial Granger causality, three major findings emerged: 1) after 6-OHDA lesions, beta band oscillations were enhanced in all three regions during walking; 2) the direction of information flow for beta oscillations among the three structures was STN→M1, STN→PPN, and PPN→M1; 3) after the treatment of levodopa, beta activity in the three regions was reduced significantly and the flow of beta band was also abrogated. Our results suggest that beta activity in the PPN is transmitted from the basal ganglia and probably comes from the STN, and the STN plays a dominant role in the network of causal interactions for beta activity. Thus, the STN may be a potential source of aberrant beta band oscillations in PD. Levodopa can inhibit beta activity in the PPN of parkinsonian rats but cannot relieve parkinsonian patients' axial symptoms clinically. Therefore, beta oscillations may not be the major cause of axial symptoms. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Interaction between viologen-phosphorus dendrimers and {alpha}-synuclein

    Energy Technology Data Exchange (ETDEWEB)

    Milowska, Katarzyna, E-mail: milowska@biol.uni.lodz.pl [Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz (Poland); Grochowina, Justyna [Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz (Poland); Katir, Nadia [Laboratoire de Chimie de Coordination CNRS, 205 route de Narbonne, 31077 Toulouse (France); El Kadib, Abdelkrim [Institute of Nanomaterials and Nanotechnology (INANOTECH)-MAScIR (Moroccan Foundation for Advanced Science, Innovation and Research), ENSET, Avenue de I' Armee Royale, Madinat El Irfane, 10100 Rabat (Morocco); Majoral, Jean-Pierre [Laboratoire de Chimie de Coordination CNRS, 205 route de Narbonne, 31077 Toulouse (France); Bryszewska, Maria; Gabryelak, Teresa [Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz (Poland)

    2013-02-15

    In this study the interaction between viologen-phosphorus dendrimers and {alpha}-synuclein (ASN) was examined. Polycationic viologen-phosphorus dendrimers (two positive charges per viologen unit) are novel compounds with relatively unknown properties. The influence of these viologen dendrimers on ASN was tested using fluorimetric and circular dichroism methods. ASN contains four tyrosine residues; therefore, the influence of dendrimers on protein molecular conformation by measuring the changes in the ASN fluorescence in the presence of dendrimers was evaluated. The interaction of dendrimers with free L-tyrosine was also monitored. Results show that viologen-phosphorus dendrimers interact with ASN; they quenched the fluorescence of ASN as well as free tyrosine by dynamic and static ways. However, the quenching was not accompanied by modifications in the ASN secondary structure. - Highlights: Black-Right-Pointing-Pointer Interaction between viologen-phosphorus dendrimers and {alpha}-synuclein (ASN) was investigated. Black-Right-Pointing-Pointer Viologen-phosphorus dendrimers can quench the fluorescence of tyrosine in ASN. Black-Right-Pointing-Pointer Dendrimers caused red-shift in maximum of fluorescence. Black-Right-Pointing-Pointer Viologen-phosphorus dendrimers did not change the secondary structure of ASN.

  17. Formation of light particles in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Zagrebaev, V.; Penionzhkevich, Yu.

    1993-01-01

    The principal experimental results on the yield of the light charged particles in nucleus-nucleus collisions at the low and intermediate energies are reviewed. Inclusive spectra of light particles and their coincidences with the characteristic KX-rays, γ-rays, neutrons, projectile-like fragments, other light particles, fission fragments, and evaporation residues are analyzed. The main theoretical models used for the description of the light particle formation are briefly outlined together with their merits and shortcomings. The unsolved problems of fast light particle formation, in particular, and of nucleus-nucleus interaction dynamics, on the whole, are discussed with the outlooks of new experiments able to clear up some of these problems. (author) 144 refs., 40 figs., 2 tabs

  18. Interaction of C-terminal truncated human alphaA-crystallins with target proteins.

    Directory of Open Access Journals (Sweden)

    Anbarasu Kumarasamy

    2008-09-01

    Full Text Available Significant portion of alphaA-crystallin in human lenses exists as C-terminal residues cleaved at residues 172, 168, and 162. Chaperone activity, determined with alcohol dehydrogenase (ADH and betaL-crystallin as target proteins, was increased in alphaA(1-172 and decreased in alphaA(1-168 and alphaA(1-162. The purpose of this study was to show whether the absence of the C-terminal residues influences protein-protein interactions with target proteins.Our hypothesis is that the chaperone-target protein binding kinetics, otherwise termed subunit exchange rates, are expected to reflect the changes in chaperone activity. To study this, we have relied on fluorescence resonance energy transfer (FRET utilizing amine specific and cysteine specific fluorescent probes. The subunit exchange rate (k for ADH and alphaA(1-172 was nearly the same as that of ADH and alphaA-wt, alphaA(1-168 had lower and alphaA(1-162 had the lowest k values. When betaL-crystallin was used as the target protein, alphaA(1-172 had slightly higher k value than alphaA-wt and alphaA(1-168 and alphaA(1-162 had lower k values. As expected from earlier studies, the chaperone activity of alphaA(1-172 was slightly better than that of alphaA-wt, the chaperone activity of alphaA(1-168 was similar to that of alphaA-wt and alphaA(1-162 had substantially decreased chaperone activity.Cleavage of eleven C-terminal residues including Arg-163 and the C-terminal flexible arm significantly affects the interaction with target proteins. The predominantly hydrophilic flexible arm appears to be needed to keep the chaperone-target protein complex soluble.

  19. Differences Between a Single- and a Double-Folding Nucleus-^{9}Be Optical Potential

    Science.gov (United States)

    Bonaccorso, A.; Carstoiu, F.; Charity, R. J.; Kumar, R.; Salvioni, G.

    2016-05-01

    We have recently constructed two very successful n-^9Be optical potentials (Bonaccorso and Charity in Phys Rev C89:024619, 2014). One by the Dispersive Optical Model (DOM) method and the other (AB) fully phenomenological. The two potentials have strong surface terms in common for both the real and the imaginary parts. This feature makes them particularly suitable to build a single-folded (light-) nucleus-^9Be optical potential by using ab-initio projectile densities such as those obtained with the VMC method (Wiringa http://www.phy.anl.gov/theory/research/density/). On the other hand, a VMC density together with experimental nucleon-nucleon cross-sections can be used also to obtain a neutron and/or proton-^9Be imaginary folding potential. We will use here an ab-initio VMC density (Wiringa http://www.phy.anl.gov/theory/research/density/) to obtain both a n-^9Be single-folded potential and a nucleus-nucleus double-folded potential. In this work we report on the cases of ^8B, ^8Li and ^8C projectiles. Our approach could be the basis for a systematic study of optical potentials for light exotic nuclei scattering on such light targets. Some of the projectiles studied are cores of other exotic nuclei for which neutron knockout has been used to extract spectroscopic information. For those cases, our study will serve to make a quantitative assessment of the core-target part of the reaction description, in particular its localization.

  20. Dorsal raphe nucleus projecting retinal ganglion cells: Why Y cells?

    Science.gov (United States)

    Pickard, Gary E.; So, Kwok-Fai; Pu, Mingliang

    2015-01-01

    Retinal ganglion Y (alpha) cells are found in retinas ranging from frogs to mice to primates. The highly conserved nature of the large, fast conducting retinal Y cell is a testament to its fundamental task, although precisely what this task is remained ill-defined. The recent discovery that Y-alpha retinal ganglion cells send axon collaterals to the serotonergic dorsal raphe nucleus (DRN) in addition to the lateral geniculate nucleus (LGN), medial interlaminar nucleus (MIN), pretectum and the superior colliculus (SC) has offered new insights into the important survival tasks performed by these cells with highly branched axons. We propose that in addition to its role in visual perception, the Y-alpha retinal ganglion cell provides concurrent signals via axon collaterals to the DRN, the major source of serotonergic afferents to the forebrain, to dramatically inhibit 5-HT activity during orientation or alerting/escape responses, which dis-facilitates ongoing tonic motor activity while dis-inhibiting sensory information processing throughout the visual system. The new data provide a fresh view of these evolutionarily old retinal ganglion cells. PMID:26363667

  1. Interactive domains in the molecular chaperone human alphaB crystallin modulate microtubule assembly and disassembly.

    Directory of Open Access Journals (Sweden)

    Joy G Ghosh

    2007-06-01

    Full Text Available Small heat shock proteins regulate microtubule assembly during cell proliferation and in response to stress through interactions that are poorly understood.Novel functions for five interactive sequences in the small heat shock protein and molecular chaperone, human alphaB crystallin, were investigated in the assembly/disassembly of microtubules and aggregation of tubulin using synthetic peptides and mutants of human alphaB crystallin.The interactive sequence (113FISREFHR(120 exposed on the surface of alphaB crystallin decreased microtubule assembly by approximately 45%. In contrast, the interactive sequences, (131LTITSSLSSDGV(142 and (156ERTIPITRE(164, corresponding to the beta8 strand and the C-terminal extension respectively, which are involved in complex formation, increased microtubule assembly by approximately 34-45%. The alphaB crystallin peptides, (113FISREFHR(120 and (156ERTIPITRE(164, inhibited microtubule disassembly by approximately 26-36%, and the peptides (113FISREFHR(120 and (131LTITSSLSSDGV(142 decreased the thermal aggregation of tubulin by approximately 42-44%. The (131LTITSSLSSDGV(142 and (156ERTIPITRE(164 peptides were more effective than the widely used anti-cancer drug, Paclitaxel, in modulating tubulinmicrotubule dynamics. Mutagenesis of these interactive sequences in wt human alphaB crystallin confirmed the effects of the alphaB crystallin peptides on microtubule assembly/disassembly and tubulin aggregation. The regulation of microtubule assembly by alphaB crystallin varied over a narrow range of concentrations. The assembly of microtubules was maximal at alphaB crystallin to tubulin molar ratios between 1:4 and 2:1, while molar ratios >2:1 inhibited microtubule assembly.Interactive sequences on the surface of human alphaB crystallin collectively modulate microtubule assembly through a dynamic subunit exchange mechanism that depends on the concentration and ratio of alphaB crystallin to tubulin. These are the first

  2. Interactions between Brainstem Noradrenergic Neurons and the Nucleus Accumbens Shell in Modulating Memory for Emotionally Arousing Events

    Science.gov (United States)

    Kerfoot, Erin C.; Williams, Cedric L.

    2011-01-01

    The nucleus accumbens shell (NAC) receives axons containing dopamine-[beta]-hydroxylase that originate from brainstem neurons in the nucleus of the solitary tract (NTS). Recent findings show that memory enhancement produced by stimulating NTS neurons after learning may involve interactions with the NAC. However, it is unclear whether these…

  3. Investigation of the influence of nuclear matter on hard neutrino nucleus interaction using the HARDPING Monte Carlo Event Generator

    International Nuclear Information System (INIS)

    Berdnikov, Ya.A.; Berdnikov, A.Ya.; Kim, V.T.; Ivanov, A.E.; Suetin, D.P.; Tiangov, K.D.

    2016-01-01

    Hadron production in neutrino-nucleus interactions is implemented in Monte Carlo event generator HARDPING (HARD Probe INteraction Generator). Such effects as formation length, energy loss and multiple rescattering for produced hadrons and their constituents are taken into account in HARDPING. Available data from WA/59 and SCAT collaborations on hadron production in neutrino-nucleus collisions is described by HARDPING with a reasonable agreement

  4. Hadron-nucleus collisions

    International Nuclear Information System (INIS)

    Strugalski, Z.

    1981-01-01

    Qualitative picture of high energy hadron-nucleus collision process, emerging from the analysis of experimental data, is presented. Appropriate description procedure giving a possibility of reproducing various characteristics of this process in terms of the data on elementary hadron-nucleon interaction is proposed. Formula reproducing hadron-nucleus collision cross sections is derived. Inelastic collision cross sections for pion-nucleus and proton-nucleus reactions at wide energy interval are calculated for Pb, Ag, and Al targets. A-dependence of cross sections for pion-nucleus and proton-nucleus collisions at nearly 50 GeV/c momentum were calculated and compared with existing experimental data. Energy dependence of cross sections for hadron-nucleus collisions is determined simply by energy dependence of corresponding cross sections for hadron-nucleon collisions; A-dependence is determined simply by nuclear sizes and nucleon density distributions in nuclei

  5. Drugs interacting with alpha adrenoceptors

    NARCIS (Netherlands)

    van Zwieten, P. A.

    1989-01-01

    Alpha adrenoceptors should be divided into various subtypes, comprising pre/postsynaptic and alpha 1/alpha 2-subpopulations, respectively. This classification implicates important functional differences between the various alpha-receptor subtypes, including certain differences in signal transduction

  6. Current generation by alpha particles interacting with lower hybrid waves in TOKAMAKS

    International Nuclear Information System (INIS)

    Belikov, V.S.; Kolesnichenko, Ya.I.; Lisak, M.; Anderson, D.

    1990-01-01

    The problem of the influence of fusion generated alpha particles on lower-hybrid-wave current drive is examined. Analysis is based on a new equation for the LH-wave-fast ion interaction which is derived by taking into consideration the non-zero value of the longitudinal wave number. The steady-state velocity distribution function for high energy alpha particles is found. The alpha current driven by LH-waves as well as the RF-power absorbed by alpha particle are calculated. (authors)

  7. Multiparticle excitations in the 149 Gd superdeformed nucleus. Signature of new C4 nucleus symmetry

    International Nuclear Information System (INIS)

    Theisen, C.

    1995-01-01

    The use of 8 π and EUROGAM phase I multi-detectors for the study of high spin states of 149 Gd nucleus has revealed unexpected new phenomenons about the superdeformation in this nucleus. The new excited bands confirm the omnipresence of twin bands phenomenon. A new multi-particle excitation (two protons and one neutron) has been discovered. Thanks to the second generation EUROGAM detector, unexpected discoveries such as C 4 symmetry, level interactions, complete backbending were obtained for the second potential well. The knowledge of interacting levels gives informations about the nucleon-nucleon residual interaction and could allow the determination of SD bands excitation energy. The complex processing and analysis of high multiplicity events has led to the development of new computing tools. An automatic band research program has been written for the discovery of new excited bands, and an exact method for the elimination of uncorrected events has been developed. The improvements of multi-detector performances should allow the discovery of more exceptional phenomenons and new anomalies in the SD bands. (J.S.). 222 refs., 86 figs., 38 tabs

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

    Science.gov (United States)

    Sánchez, F.

    2016-05-01

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

  9. Effect of secondary structure on the potential of mean force for poly-L-lysine in the alpha-Helix and beta-sheet conformations

    Energy Technology Data Exchange (ETDEWEB)

    Grigsby, J.J.; Blanch, H.W.; Prausnitz, J.M.

    2001-10-30

    Because poly-L-lysine (PLL) can exist in the {alpha}-helix or {beta}-sheet conformation depending on solution preparation and solution conditions, PLL is a suitable candidate to probe the dependence of protein interactions on secondary structure. The osmotic second virial coefficient and weight-average molecular weight are reported from low-angle laser-light scattering measurements for PLL as a function of NaCl concentration, pH, and {alpha}-helix or {beta}-sheet content. Interactions between PLL molecules become more attractive as salt concentration increases due to screening of PLL charge by salt ions and at low salt concentration become more attractive as pH increases due to decreased net charge on PLL. The experimental results show that interactions are stronger for the {beta}-sheet conformation than for the {alpha}-helix conformation. A spherically-symmetric model for the potential of mean force is used to account for specific interactions not described by DLVO theory and to show how differences in secondary structure affect PLL interactions.

  10. Multi-quark effects in high energy nucleon-nucleon and nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Besliu, C.; Caraciuc, I.; Jipa, A.; Olariu, A.; Topor-Pop, R.; Cotorobai, F.; Pantea, D.; Popa, L.; Popa, V.; Topor-Pop, V.

    1988-02-01

    Recent data obtained in two experiments performed in the framework of the Bucharest-Dubna collaboration are presented, i.e.: the observation of narrow dibaryonic resonances is neutron-proton interactions in 1mHBC at different momenta of incident neutrons in the range 1-5 GeV/c, and the cumulative production of negative pions in nucleus-nucleus interactions in SKM-200 streamer chamber at 4.5 GeV/c. (authors)

  11. A transmembrane polar interaction is involved in the functional regulation of integrin alpha L beta 2.

    Science.gov (United States)

    Vararattanavech, Ardcharaporn; Chng, Choon-Peng; Parthasarathy, Krupakar; Tang, Xiao-Yan; Torres, Jaume; Tan, Suet-Mien

    2010-05-14

    Integrins are heterodimeric transmembrane (TM) receptors formed by noncovalent associations of alpha and beta subunits. Each subunit contains a single alpha-helical TM domain. Inside-out activation of an integrin involves the separation of its cytoplasmic tails, leading to disruption of alphabeta TM packing. The leukocyte integrin alpha L beta 2 is required for leukocyte adhesion, migration, proliferation, cytotoxic function, and antigen presentation. In this study, we show by mutagenesis experiments that the packing of alpha L beta 2 TMs is consistent with that of the integrin alpha IIb beta 3 TMs. However, molecular dynamics simulations of alpha L beta 2 TMs in lipids predicted a polar interaction involving the side chains of alpha L Ser1071 and beta2 Thr686 in the outer-membrane association clasp (OMC). This is supported by carbonyl vibrational shifts observed in isotope-labeled alpha L beta 2 TM peptides that were incorporated into lipid bilayers. Molecular dynamics studies simulating the separation of alpha L beta 2 tails showed the presence of polar interaction during the initial perturbation of the inner-membrane association clasp. When the TMs underwent further separation, the polar interaction was disrupted. OMC polar interaction is important in regulating the functions of beta2 integrins because mutations that disrupt the OMC polar interaction generated constitutively activated alpha L beta 2, alpha M beta 2, and alpha X beta 2 in 293T transfectants. We also show that the expression of mutant beta2 Thr686Gly in beta2-deficient T cells rescued cell adhesion to intercellular adhesion molecule 1, but the cells showed overt elongated morphologies in response to chemokine stromal-cell-derived factor 1 alpha treatment as compared to wild-type beta2-expressing cells. These two TM polar residues are totally conserved in other members of the beta2 integrins in humans and across different species. Our results provide an example of the stabilizing effect of polar

  12. Antiproton-nucleus inelastic scattering and the spin-isospin dependence of the N anti N interaction

    International Nuclear Information System (INIS)

    Dover, C.B.

    1985-01-01

    A general overview of the utility of antinucleon (anti N)-nucleus inelastic scattering studies is presented, emphasizing both the sensitivity of the cross sections to various components of the N anti N transition amplitudes and the prospects for the exploration of some novel aspects of nuclear structure. We start with an examination of the relation between NN and N anti N potentials, focusing on the coherences predicted for the central, spin-orbit and tensor components, and how these may be revealed by measurements of two-body spin observables. We next discuss the role of the nucleus as a spin and isospin filter, and show how, by a judicious choice of final state quantum numbers (natural or unnatural parity states, isospin transfer ΔT=0 or 1) and momentum transfer q, one can isolate different components of the N anti N transition amplitude. Various models for the N anti N interaction which give reasonable fits to the available two-body data are shown to lead to strikingly different predictions for certain spin-flip nuclear transitions. We suggest several possible directions for future anti N-nucleus inelastic scattering experiments at LEAR, for instance the study of spin observables which would be accessible with polarized anti N beams, charge exchange reactions, and higher resolution studies of the (anti p, anti p') reaction. We compare the antinucleon and the nucleon as a probe of nuclear modes of excitation. 34 refs

  13. ψ' and J/ψ suppression in high-energy nucleon-nucleus and nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Wong, Cheuk-Yin.

    1995-01-01

    The observed features of ψ' to J/ψ suppression in pA and nucleus-nucleus collisions can be explained in terms of a two-component absorption model. For the hard component of the absorption due to the interaction of the produced c bar c systems with baryons at high relative energies, the absorption cross sections are insensitive to the radii of the c bar c systems, as described by the Additive Quark Model. For the soft component due to the low energy c bar c interactions with soft particles produced by other baryon-baryon collisions, the absorption cross sections are greater for ψ' than for J/ψ, because the breakup threshold for ψ' is much smaller than for ψ

  14. Determinants of RNA polymerase alpha subunit for interaction with beta, beta', and sigma subunits: hydroxyl-radical protein footprinting.

    OpenAIRE

    Heyduk, T; Heyduk, E; Severinov, K; Tang, H; Ebright, R H

    1996-01-01

    Escherichia coli RNA polymerase (RNAP) alpha subunit serves as the initiator for RNAP assembly, which proceeds according to the pathway 2 alpha-->alpha 2-->alpha 2 beta-->alpha 2 beta beta'-->alpha 2 beta beta' sigma. In this work, we have used hydroxyl-radical protein footprinting to define determinants of alpha for interaction with beta, beta', and sigma. Our results indicate that amino acids 30-75 of alpha are protected from hydroxyl-radical-mediated proteolysis upon interaction with beta ...

  15. A study of compound particles in pion-nucleus interactions

    International Nuclear Information System (INIS)

    Ahmad, Tufail

    2012-01-01

    In this paper, the phenomenon of multiparticle production has been studied using the nuclear emulsion technique. Nuclear emulsion is a material which memorises the tracks of charged particles. When an incident particle interacts with the nuclei of the emulsion, secondary particles are produced. These secondary particles are classified into three categories viz., shower (Ns), grey (Ng) and black (Nb) particles. The investigation of particle-nucleus collisions is fundamental for understanding the nature of the interaction process. In such studies most of the attention was paid to the relativistic charged particles that is showers (1-3). From the survey of literature it is found that slow particles (grey and black) are less studied in comparison to charged shower particles. Grey particles may provide some valuable information and it may be taken as good measure of number of collisions made by the incident particle

  16. Classical gluon production amplitude for nucleus-nucleus collisions:First saturation correction in the projectile

    International Nuclear Information System (INIS)

    Chirilli, Giovanni A.; Kovchegov, Yuri V.; Wertepny, Douglas E.

    2015-01-01

    We calculate the classical single-gluon production amplitude in nucleus-nucleus collisions including the first saturation correction in one of the nuclei (the projectile) while keeping multiple-rescattering (saturation) corrections to all orders in the other nucleus (the target). In our approximation only two nucleons interact in the projectile nucleus: the single-gluon production amplitude we calculate is order-g"3 and is leading-order in the atomic number of the projectile, while resumming all order-one saturation corrections in the target nucleus. Our result is the first step towards obtaining an analytic expression for the first projectile saturation correction to the gluon production cross section in nucleus-nucleus collisions.

  17. Nuclear alpha spectrin: Critical roles in DNA interstrand cross-link repair and genomic stability

    OpenAIRE

    Lambert, Muriel W

    2016-01-01

    Non-erythroid alpha spectrin (?IISp) is a structural protein which we have shown is present in the nucleus of human cells. It interacts with a number of nuclear proteins such as actin, lamin, emerin, chromatin remodeling factors, and DNA repair proteins. ?IISp?s interaction with DNA repair proteins has been extensively studied. We have demonstrated that nuclear ?IISp is critical in DNA interstrand cross-link (ICL) repair in S phase, in both genomic (non-telomeric) and telomeric DNA, and in ma...

  18. Partial inelasticity coefficients of negative pions produced in hadron-nucleus and nucleus-nucleus collisions at high energies

    International Nuclear Information System (INIS)

    OLIMOV, K.; LUTPULLAEV, S.L.; PETROV, V.I.; OLIMOV, A.K.

    2015-01-01

    New experimental data on the partial inelasticity coefficients of negative pions produced in "1"6Op-collisions at 3.25 A GeV/s, pC-interactions at 4.2 and 9.9 GeV/s, and d,α,C(C)-collisions at 4.2 A GeV/s are presented. It is established that the behavior of partial inelasticity coefficients of pions at intermediate energies (<10 GeV) in hadron-nucleus collisions has a transitional character, reaching the limiting value at ultrahigh energies. It is shown that the mean values of partial inelasticity coefficients of pions produced in nucleus-nucleus collisions decrease with an increase in mass number of the projectile nucleus. (authors)

  19. Simulation of Alpha Particles in Rotating Plasma Interacting with a Stationary Ripple

    International Nuclear Information System (INIS)

    Fetterman, Abraham J.; Fisch, Nathaniel J.

    2011-01-01

    Superthermal ExB rotation can provide magnetohydrodynamic (MHD) stability and enhanced confinement to axisymmetric mirrors. However, the rotation speed has been limited by phenomena at end electrodes. A new prediction is that rotation might instead be produced using a magnetic ripple and alpha particle kinetic energy, in an extension of the alpha channeling concept. The interaction of alpha particles with the ripple results in visually interesting and practically useful orbits.

  20. Pion inelastic scattering and the pion-nucleus effective interaction

    International Nuclear Information System (INIS)

    Carr, J.A.

    1983-01-01

    This work examines pion inelastic scattering with the primary purpose of gaining a better understanding of the properties of the pion-nucleus interaction. The main conclusion of the work is that an effective interaction which incorporates the most obvious theoretical corrections to the impulse approximation does a good job of explaining pion elastic and inelastic scattering from zero to 200 MeV without significant adjustments to the strength parameters of the force. Watson's multiple scattering theory is used to develop a theoretical interaction starting from the free pion-nucleon interaction. Elastic scattering was used to calibrate the isoscalar central interaction. It was found that the impulse approximation did poorly at low energy, while the multiple scattering corrections gave good agreement with all of the data after a few minor adjustments in the force. The distorted wave approximation for the inelastic transition matrix elements are evaluated for both natural and unnatural parity excitations. The isoscalar natural parity transitions are used to test the reaction theory, and it is found that the effective interaction calibrated by elastic scattering produces good agreement with the inelastic data. Calculations are also shown for other inelastic and charge exchange reactions. It appears that the isovector central interaction is reasonable, but the importance of medium corrections cannot be determined. The unnatural parity transitions are also reasonably described by the theoretical estimate of the spin-orbit interaction, but not enough systematic data exists to reach a firm conclusion

  1. Simulation study of proton inelastic interaction with nuclei in the 50 to 350 MeV range by Monte Carlo Method

    International Nuclear Information System (INIS)

    Peres, J.C.

    1982-11-01

    This study settles a contribution to the proton-nucleus inelastic interaction simulation. Experimental display of deuton, triton, ion 3 He and alpha clusters in nucleus led us to include them in intranuclear cascade. We use a FERMI type distribution of nucleons; knowledge of each fundamental phenomenon allowed us to follow every particle moving in the medium. Inelastic interaction simulation was performed by the use of a MONTE CARLO method [fr

  2. Production of neutrinos and neutrino-like particles in proton-nucleus interactions

    International Nuclear Information System (INIS)

    Dishaw, J.P.

    1979-03-01

    An experimental search was performed to look for the direct production of neutrinos or neutrino-like particles, i.e., neutral particles which interact weakly with hadrons, in proton-nucleus interactions at 400 GeV incident proton energy. Possible sources of such particles include the semi-leptonic decay of new heavy particles such as charm, and the direct production of a light neutral Higgs particle such as the axion. The production of these particles has been inferred in this experiment by energy nonconservation in the collision of a proton with an iron nucleus. The total visible energy of the interaction was measured using a sampling ionization calorimeter. After correcting for beam intensity effects and cutting the data to eliminate systematic effects in the measurement, the final resolution of the calorimeter was 3.51% and increased with decreasing incident beam energy with a square root dependence on the beam energy. Energy nonconservation in the data is manifest as a non-Gaussian distribution on the low side of the calorimeter measured energy. Model calculations yield the fraction of events expected in this non-Gaussian behavior for the various sources of neutrinos or neutrino-like particles. A maximum likelihood fit to the data with the theoretical fraction of events expected yields the 95% confidence level production cross section upper limit values. The upper limits for general production of neutrino-like particles for various parameterizations of the production cross section are presented. The following specific upper limits have been established: charm particle production -3 times the π 0 production cross section. 144 references

  3. Identification of potential target genes of ROR-alpha in THP1 and HUVEC cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Gulec, Cagri, E-mail: cagri.gulec@gmail.com; Coban, Neslihan, E-mail: neslic@istanbul.edu.tr; Ozsait-Selcuk, Bilge, E-mail: ozsaitb@istanbul.edu.tr; Sirma-Ekmekci, Sema, E-mail: semasirma@gmail.com; Yildirim, Ozlem, E-mail: ozlm-yildirim@hotmail.com; Erginel-Unaltuna, Nihan, E-mail: nihanerginel@yahoo.com

    2017-04-01

    ROR-alpha is a nuclear receptor, activity of which can be modulated by natural or synthetic ligands. Due to its possible involvement in, and potential therapeutic target for atherosclerosis, we aimed to identify ROR-alpha target genes in monocytic and endothelial cell lines. We performed chromatin immunoprecipitation (ChIP) followed by tiling array (ChIP-on-chip) for ROR-alpha in monocytic cell line THP1 and endothelial cell line HUVEC. Following bioinformatic analysis of the array data, we tested four candidate genes in terms of dependence of their expression level on ligand-mediated ROR-alpha activity, and two of them in terms of promoter occupancy by ROR-alpha. Bioinformatic analyses of ChIP-on-chip data suggested that ROR-alpha binds to genomic regions near the transcription start site (TSS) of more than 3000 genes in THP1 and HUVEC. Potential ROR-alpha target genes in both cell types seem to be involved mainly in membrane receptor activity, signal transduction and ion transport. While SPP1 and IKBKA were shown to be direct target genes of ROR-alpha in THP1 monocytes, inflammation related gene HMOX1 and heat shock protein gene HSPA8 were shown to be potential target genes of ROR-alpha. Our results suggest that ROR-alpha may regulate signaling receptor activity, and transmembrane transport activity through its potential target genes. ROR-alpha seems also to play role in cellular sensitivity to environmental substances like arsenite and chloroprene. Although, the expression analyses have shown that synthetic ROR-alpha ligands can modulate some of potential ROR-alpha target genes, functional significance of ligand-dependent modulation of gene expression needs to be confirmed with further analyses.

  4. Study of high energy densities over extended nuclear volumes via nucleus-nucleus collisions at the SPS

    CERN Multimedia

    2002-01-01

    This experiment examines in detail the characteristics of ultra-relativistic nucleus-nucleus interactions using $^{16}$O beams of 200 GeV/A from the SPS. The experiment combines 4$\\pi$ calorimeter coverage with measurements of inclusive particle spectra, two-particle correlations, low and high-mass lepton pairs and photons. A multiwire active target allows maximum interaction rates with a minimum of secondary interactions. Additional data are taken with an emulsion target.

  5. The reactive content of the proton-nucleus impulse - approximation Dirac optical potential

    International Nuclear Information System (INIS)

    Carlson, B.V.; Isidro Filho, M.P.; Hussein, M.S.

    1984-01-01

    The total reaction cross sections for intermediate energy proton scattering on 40 Ca and 208 Pb are calculated within the Dirac-Eikonal formalism. Comparison with data indicate that the recently proposed impulse-approximation Dirac optical potential for nucleon-nucleus scattering, is not absorptive enough. (Author) [pt

  6. Experimental studies of pion-nucleus and nucleon-nucleus interactions at intermediate energies. Progress report, April 1, 1991--March 31, 1994

    International Nuclear Information System (INIS)

    1993-01-01

    This report summarizes the work on experimental research in intermediate energy nuclear physics carried out at New Mexico State University in 1991-94 under a grant from the U.S. Department of Energy. Most of these studies involved investigations of various pion-nucleus interactions and nucleon-nucleus charge-exchange reactions. The work was carried out with the LAMPF accelerator at the Los Alamos National Laboratory and the cyclotrons at the Paul Scherrer Institute (PSI) near Zurich, Switzerland, at Indiana University (IUCF), and at TRIUMF in Vancouver, Canada, as collaborative efforts among several laboratories and universities. We have also worked on plans and preparations for new experiments involving studies of the quark structure of nucleons and nuclei, which would be carried out at Fermilab (FNAL), near Chicago, and at the HERA facility at the DESY laboratory in Hamburg, Germany. The NMSU personnel included two faculty members, five postdoctoral research associates, nine graduate students, and one undergraduate student

  7. Monte Carlo event generator MCMHA for high energy hadron-nucleus collisions and intranuclear cascade interactions

    International Nuclear Information System (INIS)

    Iga, Y.; Hamatsu, R.; Yamazaki, S.

    1988-01-01

    The Monte Carlo event generator for high energy hadron-nucleus (h-A) collisions has been developed which is based on the multi-chain model. The concept of formation zone and the cascade interactions of secondary particles are properly taken into account in this Monte Carlo code. Comparing the results of this code with experimental data, the importance of intranuclear cascade interactions becomes very clear. (orig.)

  8. Fanconi anemia protein, FANCG, is a phosphoprotein and is upregulated with FANCA after TNF-alpha treatment.

    Science.gov (United States)

    Futaki, M; Watanabe, S; Kajigaya, S; Liu, J M

    2001-02-23

    Fanconi anemia (FA) is a genetic syndrome characterized by bone marrow failure, birth defects, and a predisposition to malignancy. At this time, six FA genes have been identified, and several gene products have been found to interact in a protein complex. FA cells appear to overexpress the proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha). We therefore examined the effects of TNF-alpha on the regulation of FA complementation group proteins, FANCG and FANCA. We found that treatment with TNF-alpha induced FANCG protein expression. FANCA was induced concurrently with FANCG, and the FANCA/FANCG complex was increased in the nucleus following TNF-alpha treatment. Inactivation of inhibitory kappa B kinase-2 modulated the expression of FANCG. We also found that both nuclear and cytoplasmic FANCG fractions were phosphorylated. These results show that FANCG is a phosphoprotein and suggest that the cellular accumulation of FA proteins is subject to regulation by TNF-alpha signaling.

  9. Optical model calculation of neutron-nucleus scattering cross sections

    International Nuclear Information System (INIS)

    Smith, M.E.; Camarda, H.S.

    1980-01-01

    A program to calculate the total, elastic, reaction, and differential cross section of a neutron interacting with a nucleus is described. The interaction between the neutron and the nucleus is represented by a spherically symmetric complex potential that includes spin-orbit coupling. This optical model problem is solved numerically, and is treated with the partial-wave formalism of scattering theory. The necessary scattering theory required to solve this problem is briefly stated. Then, the numerical methods used to integrate the Schroedinger equation, calculate derivatives, etc., are described, and the results of various programming tests performed are presented. Finally, the program is discussed from a user's point of view, and it is pointed out how and where the program (OPTICAL) can be changed to satisfy particular needs

  10. Theta and Alpha Oscillations in Attentional Interaction during Distracted Driving

    Directory of Open Access Journals (Sweden)

    Yu-Kai Wang

    2018-02-01

    Full Text Available Performing multiple tasks simultaneously usually affects the behavioral performance as compared with executing the single task. Moreover, processing multiple tasks simultaneously often involve more cognitive demands. Two visual tasks, lane-keeping task and mental calculation, were utilized to assess the brain dynamics through 32-channel electroencephalogram (EEG recorded from 14 participants. A 400-ms stimulus onset asynchrony (SOA factor was used to induce distinct levels of attentional requirements. In the dual-task conditions, the deteriorated behavior reflected the divided attention and the overlapping brain resources used. The frontal, parietal and occipital components were decomposed by independent component analysis (ICA algorithm. The event- and response-related theta and alpha oscillations in selected brain regions were investigated first. The increased theta oscillation in frontal component and decreased alpha oscillations in parietal and occipital components reflect the cognitive demands and attentional requirements as executing the designed tasks. Furthermore, time-varying interactive over-additive (O-Add, additive (Add and under-additive (U-Add activations were explored and summarized through the comparison between the summation of the elicited spectral perturbations in two single-task conditions and the spectral perturbations in the dual task. Add and U-Add activations were observed while executing the dual tasks. U-Add theta and alpha activations dominated the posterior region in dual-task situations. Our results show that both deteriorated behaviors and interactive brain activations should be comprehensively considered for evaluating workload or attentional interaction precisely.

  11. Level Density In Interacting Boson-Fermion-Fermion Model (IBFFM) Of The Odd-Odd Nucleus 196Au

    International Nuclear Information System (INIS)

    Kabashi, Skender; Bekteshi, Sadik

    2007-01-01

    The level density of the odd-odd nucleus 196Au is investigated in the interacting boson-fermion-fermion model (IBFFM) which accounts for collectivity and complex interaction between quasiparticle and collective modes.The IBFFM total level density is fitted by Gaussian and its tail is also fitted by Bethe formula and constant temperature Fermi gas model

  12. Activation of MEK 1/2 and p42/44 MAPK by Angiotensin II in Hepatocyte Nucleus and their Potentiation by Ethanol

    Science.gov (United States)

    Aroor, Annayya R.; Lee, Youn Ju; Shukla, Shivendra D.

    2009-01-01

    Hepato-subcellular effect of Ang II and ethanol on the p42/44 MAP Kinase and MEK1/2 were investigated in the nucleus of rat hepatocytes. Hepatocytes were treated with ethanol (100 mM) for 24 hr and stimulated with angiotensin II (Ang II, 100 nM, 5 min). The levels of p42/44 MAPK and MEK1/2 were monitored in the nuclear fraction using antibodies. Ang II itself caused significant accumulation of phospho-p42/44 MAPK in the nucleus without any significant translocation of p42/44 MAPK protein there by suggesting activation of p42/44 MAPK in the nucleus. Ang II caused marked accumulation of phospho-MEK 1/2 in the nucleus without any significant accumulation of MEK1/2 protein. Ratio of phospho-MEK 1/2 to MEK 1/2 protein in the nucleus after Ang II treatment was 2.4 times greater than control suggesting phosphorylation of MEK 1/2 inside the nucleus. Ethanol had no effect on the protein level or the activation of p42/44 MAPK in the nucleus. Ethanol treatment potentiated nuclear activation of p42/44 MPAK by Ang II but not translocation of p42/44 MAPK protein. This was accompanied by potentiation of Ang II stimulated accumulation of phospho-MEK 1/2 in the nucleus by ethanol. MEK 1/2 inhibitor, U-0126 inhibited Ang II response or its potentiation by ethanol. These results suggest that Ang II mediated accumulation of phospho-p42/44 MAPK in the hepatocyte nucleus involves MEK 1/2 dependent activation and this effect is potentiated by ethanol. PMID:19560630

  13. Stochastic resonance in underdamped periodic potential systems with alpha stable Lévy noise

    Science.gov (United States)

    Liu, Ruo-Nan; Kang, Yan-Mei

    2018-06-01

    In this paper, we investigate the effect of alpha stable Lévy noise with alpha stability index α (0 noise (0 noise has a more notable impact on the resonant effect of the asymmetric ratchet potential than that of the symmetric sinusoidal potential because of symmetry breaking.

  14. Recent results in the development of a global medium-energy nucleon-nucleus optical-model potential

    International Nuclear Information System (INIS)

    Madland, D.G.

    1988-02-01

    Initial results are presented for the determination of a global medium-energy nucleon-nucleus phenomenological optical-model potential using a relativistic Schroedinger representation. The starting point for this work is the global phenomenological optical-model potential of Schwandt /ital et al./, which is based on measured elastic scattering cross sections and analyzing power for polarized protons ranging from 80 to 180 MeV. This potential is optimally modified to reproduce experimental proton reaction cross sections as a function of energy, while allowing only minimal deterioration in the fits to the elastic cross sections and analyzing powers. Further modifications in the absorptive potential were found necessary to extrapolate the modified potential to higher energies. The final potential is converted to a neutron-nucleus potential by use of standard Lane model assumptions and by accounting approximately for the Coulomb correction. Comparisons of measured and calculated proton reaction and neutron total cross sections are presented for 27 Al, 56 Fe, and 208 Pb. Medium-energy optical-model potentials for complex projectiles are briefly discussed in an appendix. 7 refs., 20 figs

  15. Self-consistent theory of hadron-nucleus scattering. Application to pion physics

    International Nuclear Information System (INIS)

    Johnson, M.B.

    1980-01-01

    The requirement of using self-consistent amplitudes to evaluate microscopically the scattering of strongly interacting particles from nuclei is developed. Application of the idea to a simple model of pion-nucleus scattering is made. Numerical results indicate that the expansion of the optical potential converges when evaluated in terms of fully self-consistent quantities. A comparison of the results to a recent determination of the spreading interaction in the phenomenological isobar-hole model shows that the theory accounts for the sign and magnitude of the real and imaginary part of the spreading interaction with no adjusted parameters. The self-consistnt theory has a strong density dependence, and the consequences of this for pion-nucleus scattering are discussed. 18 figures, 1 table

  16. Social interaction and cocaine conditioning in mice increase spontaneous spike frequency in the nucleus accumbens or septal nuclei as revealed by multielectrode array recordings.

    Science.gov (United States)

    Kummer, Kai K; El Rawas, Rana; Kress, Michaela; Saria, Alois; Zernig, Gerald

    2015-01-01

    Both cocaine and social interaction place preference conditioning lead to increased neuronal expression of the immediate early gene EGR1 in the nucleus accumbens, a central region of the reward pathway, suggesting that both drug and natural rewards may be processed in similar brain regions. In order to gain novel insights into the intrinsic in vitro electrical activity of the nucleus accumbens and adjacent brain regions and to explore the effects of reward conditioning on network activity, we performed multielectrode array recordings of spontaneous firing in acute brain slices of mice conditioned to either cocaine or social interaction place preference. Cocaine conditioning increased the spike frequency of neurons in the septal nuclei, whereas social interaction conditioning increased the spike frequency in the nucleus accumbens compared to saline control animals. In addition, social interaction conditioning decreased the amount of active neuron clusters in the nucleus accumbens. Our findings suggest that place preference conditioning for both drug and natural rewards may induce persistent changes in neuronal network activity in the nucleus accumbens and the septum that are still preserved in acute slice preparations. © 2015 S. Karger AG, Basel.

  17. Daily Social Interactions and the Biological Stress Response: Are There Age Differences in Links Between Social Interactions and Alpha-Amylase?

    Science.gov (United States)

    Birditt, Kira S; Tighe, Lauren A; Nevitt, Michael R; Zarit, Steven H

    2017-12-12

    According to the strength and vulnerability integration (SAVI) model, older people are better able to avoid negative social interactions than younger people, but when they do experience negative interactions, they are equally or more emotionally and physiologically reactive than younger people. Less is known about the links between daily negative and positive social encounters and the sympathetic adrenal medullary system (a key stress pathway) and whether there are age differences in these links. This study considers whether negative and positive social interactions are associated with diurnal alpha-amylase (a measure of the sympathetic adrenal medullary system) and whether there are differences in these links by age. Participants were from the Daily Health, Stress, and Relationship Study, which includes a random sample of 89 individuals (aged 40-95) who completed 14 days of daily diary interviews and provided saliva samples four times a day (wake, 30 min after wake, lunch, and bedtime) for four of those days that were assayed for alpha-amylase. Days in which people reported more negative interactions were associated with flatter morning declines in alpha-amylase, indicating greater stress. Links between positive interactions and diurnal alpha-amylase varied by age group. Findings are consistent with the SAVI model indicating that older adults respond differently to social stimuli than younger people. © The Author(s) 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Various processes occurring in strong interactions between heavy ions: Compound nucleus formation, incomplete fusion, and quasifission

    International Nuclear Information System (INIS)

    Lefort, M.

    1975-01-01

    This paper deals with the problem of various deep processes occurring when two complex nuclei enter in collision. It is suggested that very deep inelastic processes may lead to either a compound nucleus or a composite system which shortly decays into two fission fragments (quasifission process). Particularly for heavy projectiles and targets, the predominant Coulomb potential inhibits the compound nucleus formation for low l waves. Then a critical angular momentum can be defined as the limit below which both processes (quasifission and compound nucleus formation) occur. For the heaviest nuclei, nearly all l waves below l) contribute to the quasifission phenomenon

  19. Interactions of foot-and-mouth disease virus with soluble bovine alphaVbeta3 and alphaVbeta6 integrins.

    Science.gov (United States)

    Duque, Hernando; LaRocco, Michael; Golde, William T; Baxt, Barry

    2004-09-01

    At least four members of the integrin family of receptors, alphaVbeta1, alphaVbeta3, alphaVbeta6, and alphaVbeta8, have been identified as receptors for foot-and-mouth disease virus (FMDV) in vitro. Our investigators have recently shown that the efficiency of receptor usage appears to be related to the viral serotype and may be influenced by structural differences on the viral surface (H. Duque and B. Baxt, J. Virol. 77:2500-2511, 2003). To further examine these differences, we generated soluble alphaVbeta3 and alphaVbeta6 integrins. cDNA plasmids encoding the individual complete integrin alphaV, beta3, and beta6 subunits were used to amplify sequences encoding the subunits' signal peptide and ectodomain, resulting in subunits lacking transmembrane and cytoplasmic domains. COS-1 cells were transfected with plasmids encoding the soluble alphaV subunit and either the soluble beta3 or beta6 subunit and labeled with [35S]methionine-cysteine. Complete subunit heterodimeric integrins were secreted into the medium, as determined by radioimmunoprecipitation with specific monoclonal and polyclonal antibodies. For the examination of the integrins' biological activities, stable cell lines producing the soluble integrins were generated in HEK 293A cells. In the presence of divalent cations, soluble alphaVbeta6 bound to representatives of type A or O viruses, immobilized on plastic dishes, and significantly inhibited viral replication, as determined by plaque reduction assays. In contrast, soluble alphaVbeta3 was unable to bind to immobilized virus of either serotype; however, virus bound to the immobilized integrin, suggesting that FMDV binding to alphaVbeta3 is a low-affinity interaction. In addition, soluble alphaVbeta3 did not neutralize virus infectivity. Incubation of soluble alphaVbeta6 with labeled type A12 or O1 resulted in a significant inhibition of virus adsorption to BHK cells, while soluble alphaVbeta3 caused a low (20 to 30%), but consistent, inhibition of virus

  20. Semiclassical calculations of the imaginary part of the nucleon-nucleus optical potential

    International Nuclear Information System (INIS)

    Hasse, R.W.; Schuck, P.

    1984-03-01

    We calculate for finite nuclei the imaginary part of the nucleus-nucleon optical potential on and off shell by using the local Fermi gas approximation and a finite range two-body exchange force. Results are compared with those obtained by infinite nuclear matter calculations as well as using the local density or Glauber approximation

  1. Quantitative immuno-electron microscopic analysis of depolarization-induced expression of PGC-1alpha in cultured rat visual cortical neurons.

    Science.gov (United States)

    Meng, Hui; Liang, Huan Ling; Wong-Riley, Margaret

    2007-10-17

    Peroxisome proliferator-activated receptor-gamma coactivator 1alpha (PGC- 1alpha) is a coactivator of nuclear receptors and other transcription factors that regulate several metabolic processes, including mitochondrial biogenesis, energy homeostasis, respiration, and gluconeogenesis. PGC-1alpha plays a vital role in stimulating genes that are important to oxidative metabolism and other mitochondrial functions in brown adipose tissue and skeleton muscles, but the significance of PGC-1alpha in the brain remains elusive. The goal of our present study was to determine by means of quantitative immuno-electron microscopy the expression of PGC-1alpha in cultured rat visual cortical neurons under normal conditions as well as after depolarizing stimulation for varying periods of time. Our results showed that: (a) PGC-1alpha was normally located in both the nucleus and the cytoplasm. In the nucleus, PGC-1alpha was associated mainly with euchromatin rather than heterochromatin, consistent with active involvement in transcription. In the cytoplasm, it was associated mainly with free ribosomes. (b) Neuronal depolarization by KCl for 0.5 h induced a significant increase in PGC-1alpha labeling density in both the nucleus and the cytoplasm (Pneuronal activity by synthesizing more proteins in the cytoplasm and translocating them to the nucleus for gene activation. PGC-1alpha level in neurons is, therefore, tightly regulated by neuronal activity.

  2. Some applications of the multiple scattering theory to the study of the hadron-nucleus interactions at intermediate energies

    International Nuclear Information System (INIS)

    Dedonder, J.-P.

    1979-01-01

    This work is devoted to the study of elastic hadron nucleus scattering. At first, an asymptotic evaluation leads to a closed, analytic expression of the eikonal amplitude. This approximate expression displays the role and the influence of the nuclear paremeters in, e.g., p-nucleus scattering around 1 GeV. Pion-nucleus scattering around the 3-3 resonance is then studied. A 3 body model calculation (pion, bound nucleon and residual nucleus represented by a potential) allows to study the importance of binding effects in this problem dominated by the strong energy dependence of the elementary amplitude. The last part is devoted to the construction in momentum space of a realistic optical potential and its comparison with experimental data. The scalling of π + and π - on neighbouring isotopes should allow the measure of the differences between the proton and neutron distributions in nuclei [fr

  3. Influence of the Pauli exclusion principle and the polarization of nuclei on the nuclear part of the interaction potential in the 40Ca +40Ca system

    Science.gov (United States)

    Nesterov, V. O.

    2018-06-01

    In the framework of the energy density method with the use of the wave function of the two-center shell model, the influence of the simultaneous account for the Pauli exclusion principle and the monopole and quadrupole polarizations of nuclei on the nuclear part of the potential of their interaction by the example of the 40Ca +40Ca system is considered. The calculations performed in the framework of the adiabatic approximation show that the consideration of the Pauli exclusion principle and the polarization of nuclei, especially the quadrupole one, essentially affects the nucleus-nucleus interaction potential.

  4. Cell survival following alpha particle irradiation: critical sites and implications for carcinogenesis

    International Nuclear Information System (INIS)

    Lloyd, E.L.; Gemmell, M.A.; Henning, C.B.; Gemmell, D.S.; Zabransky, B.J.

    1976-01-01

    In experiments in which mammalian cells were irradiated with 5.6 MeV alpha particles from a Tandem Van de Graaff machine we have confirmed the finding of others that the mean lethal dose (D 0 ) is about 100 rad, but by measurements of the area of the cell nuclei as irradiated we found that this mean lethal dose corresponds not to 1, as expected, but to about 27 alpha particles per cell nucleus. (The exact number appears to change slightly with cell passage number.) This allows for the possibility that the direct action of alpha particles on the nucleus may be the important event in carcinogenesis, a theory which was previously difficult to accept if a single particle hitting the nucleus anywhere was considered to be lethal. Evidence is presented to implicate the nucleolus as a possible critical site for the inhibition of reproductive integrity of the cell

  5. Three-body approach to the nucleon-nucleus optical potential

    International Nuclear Information System (INIS)

    Tandy, P.C.; Redish, E.F.; Bolle, D.

    1976-01-01

    In the Watson single scattering theory of the optical potential it is customary to approximate the propagation by two-body Green functions in order to simplify calculations. The reaction mechanism being described, however, is decidedly three-body in character. The central difficulty in building three-body models for nucleon-nucleus elastic scattering is to find the proper way of imbedding the superposed three-body reaction mechanism in the many-body problem without introducing serious overcounting effects. One would also like an explicit description of the intermediate state processes responsible for absorption. In this paper a three-body approximation to the optical potential theory is presented which overcomes the overcounting problem and is capable of including the following effects: (1) the proper kinematics of the struck nucleon, (2) its binding potential, (3) the identity of target nucleons, and (4) realistic wave functions and spectroscopic factors. The three-body model for the optical potential can be extended using unitarity methods to yield a unified three-body-like model of elastic scattering, pickup, and single nucleon knockout. (Auth.)

  6. Design, synthesis, and evaluation of an alpha-helix mimetic library targeting protein-protein interactions.

    Science.gov (United States)

    Shaginian, Alex; Whitby, Landon R; Hong, Sukwon; Hwang, Inkyu; Farooqi, Bilal; Searcey, Mark; Chen, Jiandong; Vogt, Peter K; Boger, Dale L

    2009-04-22

    The design and solution-phase synthesis of an alpha-helix mimetic library as an integral component of a small-molecule library targeting protein-protein interactions are described. The iterative design, synthesis, and evaluation of the candidate alpha-helix mimetic was initiated from a precedented triaryl template and refined by screening the designs for inhibition of MDM2/p53 binding. Upon identifying a chemically and biologically satisfactory design and consistent with the screening capabilities of academic collaborators, the corresponding complete library was assembled as 400 mixtures of 20 compounds (20 x 20 x 20-mix), where the added subunits are designed to mimic all possible permutations of the naturally occurring i, i + 4, i + 7 amino acid side chains of an alpha-helix. The library (8000 compounds) was prepared using a solution-phase synthetic protocol enlisting acid/base liquid-liquid extractions for purification on a scale that insures its long-term availability for screening campaigns. Screening of the library for inhibition of MDM2/p53 binding not only identified the lead alpha-helix mimetic upon which the library was based, but also suggests that a digestion of the initial screening results that accompany the use of such a comprehensive library can provide insights into the nature of the interaction (e.g., an alpha-helix mediated protein-protein interaction) and define the key residues and their characteristics responsible for recognition.

  7. Fast fission phenomenon, deep inelastic reactions and compound nucleus formation described within a dynamical macroscopic model

    International Nuclear Information System (INIS)

    Gregoire, C.; Ngo, C.; Remaud, B.

    1982-01-01

    We present a dynamical model to describe dissipative heavy ion reactions. It treats explicitly the relative motion of the two ions, the mass asymmetry of the system and the projection of the isospin of each ion. The deformations, which are induced during the collision, are simulated with a time-dependent interaction potential. This is done by a time-dependent transition between a sudden interaction potential in the entrance channel and an adiabatic potential in the exit channel. The model allows us to compute the compound-nucleus cross section and multidifferential cross-sections for deep inelastic reactions. In addition, for some systems, and under certain conditions which are discussed in detail, a new dissipative heavy ion collision appears: fast-fission phenomenon which has intermediate properties between deep inelastic and compound nucleus reactions. The calculated properties concerning fast fission are compared with experimental results and reproduce some of those which could not be understood as belonging to deep inelastic or compound-nucleus reactions. (orig.)

  8. Effects of cigarette smoke exposure on nicotinic acetylcholine receptor subunits {alpha}7 and {beta}2 in the sudden infant death syndrome (SIDS) brainstem

    Energy Technology Data Exchange (ETDEWEB)

    Machaalani, Rita, E-mail: rita.machaalani@sydney.edu.au [Department of Medicine, The University of Sydney, NSW 2006 (Australia); Bosch Institute, The University of Sydney, NSW 2006 (Australia); The Children' s Hospital at Westmead, NSW 2145 (Australia); Say, Meichien [Department of Medicine, The University of Sydney, NSW 2006 (Australia); Bosch Institute, The University of Sydney, NSW 2006 (Australia); Waters, Karen A. [Department of Medicine, The University of Sydney, NSW 2006 (Australia); Bosch Institute, The University of Sydney, NSW 2006 (Australia); The Children' s Hospital at Westmead, NSW 2145 (Australia)

    2011-12-15

    It is postulated that nicotine, as the main neurotoxic constituent of cigarette smoke, influences SIDS risk through effects on nicotinic acetylcholine receptors (nAChRs) in brainstem nuclei that control respiration and arousal. This study compared {alpha}7 and {beta}2 nAChR subunit expression in eight nuclei of the caudal and rostral medulla and seven nuclei of the pons between SIDS (n = 46) and non-SIDS infants (n = 14). Evaluation for associations with known SIDS risk factors included comparison according to whether infants had a history of exposure to cigarette smoke in the home, and stratification for sleep position and gender. Compared to non-SIDS infants, SIDS infants had significantly decreased {alpha}7 in the caudal nucleus of the solitary tract (cNTS), gracile and cuneate nuclei, with decreased {beta}2 in the cNTS and increased {beta}2 in the facial. When considering only the SIDS cohort: 1-cigarette smoke exposure was associated with increased {alpha}7 in the vestibular nucleus and increased {beta}2 in the rostral dorsal motor nucleus of the vagus, rNTS and Cuneate, 2-there was a gender interaction for {alpha}7 in the gracile and cuneate, and {beta}2 in the cNTS and rostral arcuate nucleus, and 3-there was no effect of sleep position on {alpha}7, but prone sleep was associated with decreased {beta}2 in three nuclei of the pons. In conclusion, SIDS infants demonstrate differences in expression of {alpha}7 and {beta}2 nAChRs within brainstem nuclei that control respiration and arousal, which is independent on prior history of cigarette smoke exposure, especially for the NTS, with additional differences for smoke exposure ({beta}2), gender ({alpha}7 and {beta}2) and sleep position ({beta}2) evident. -- Highlights: Black-Right-Pointing-Pointer The 'normal' response to smoke exposure is decreased {alpha}7 and {beta}2 in certain nuclei. Black-Right-Pointing-Pointer SIDS infants have decreased {alpha}7 in cNTS, Grac and Cun. Black

  9. The momentum distribution inside nucleus

    International Nuclear Information System (INIS)

    Fujita, T.

    1985-01-01

    Discussions are made on several reactions which can determine the momentum distribution inside nucleus. The first reaction discussed is the high energy heavy ion collision. This reaction involves many nucleons which interact strongly. Therefore, one must be careful for any possible final state interactions. The expression for the single particle momentum distribution is given. And it can be said that the expression is consistent with the description of the energetic neutrons from muon capture by heavy nucleus. The best way to determine the momentum distribution would be the lepton-nucleus scattering since it does not involve the strong interaction in the initial channel. Another reaction discussed is the backward proton production, which is governed by quite complicated reaction processes. Therefore, the determination of the momentum distribution is only indirect. Noverthless, it is found that this reaction presents a very interesting and important information on the momentum distribution. (Aoki, K.)

  10. On the dependance of the ''normalized multiplicity'' of particles produced in proton-nucleus interactions on the primary energy

    International Nuclear Information System (INIS)

    Babecki, J.

    1975-01-01

    The mean ''normalized multiplicities'' of particles produced in p-nucleus interactions: with the leading particles (R 1 ) and without them (R 2 ) were calculated from the emulsion data. The independence of R 2 of the primary energy E 0 were stated in very wide interval of E 0 from 6.2 to thousands of GeV. R 2 is approximately equal to the mean number of collisions of the primary particle in the nucleus. (author)

  11. Photo nuclear energy loss term for muon-nucleus interactions based on xi scaling model of QCD

    Science.gov (United States)

    Roychoudhury, R.

    1985-01-01

    Extensive air showers (EMC) experiments discovered a significant deviation of the ratio of structure functions of iron and deuteron from unity. It was established that the quark parton distribution in nuclei are different from the corresponding distribution in the nucleus. It was examined whether these results have an effect on the calculation of photo nucleus energy loss term for muon-nucleus nuclear interaction. Though the EMC and SLAC data were restricted to rather large q sq region it is expected that the derivation would persist even in the low q sq domain. For the ratio of iron and deuteron structure function a rather naive least square fit of the form R(x) = a + bx was taken and it is assumed that the formula is valid for the whole q sq region the absence of any knowledge of R(x) for small q sq.

  12. Suprachiasmatic Nucleus Interaction with the Arcuate Nucleus; Essential for Organizing Physiological Rhythms

    NARCIS (Netherlands)

    Buijs, Frederik N.; Guzmán-Ruiz, Mara; León-Mercado, Luis; Basualdo, Mari Carmen; Escobar, Carolina; Kalsbeek, Andries; Buijs, Ruud M.

    2017-01-01

    The suprachiasmatic nucleus (SCN) is generally considered the master clock, independently driving all circadian rhythms. We recently demonstrated the SCN receives metabolic and cardiovascular feedback adeptly altering its neuronal activity. In the present study, we show that microcuts effectively

  13. Interaction of the regulatory subunit of the cAMP-dependent protein kinase with PATZ1 (ZNF278)

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Weng-Lang [Long Island Jewish Medical Center, North Shore University Hospital, Manhasset, NY 11030 (United States); Ravatn, Roald [Department of Medicine, University of Toledo, College of Medicine, Toledo, OH 43614 (United States); Kudoh, Kazuya [Department of Medicine, University of Toledo, College of Medicine, Toledo, OH 43614 (United States); Department of Obstetrics and Gynecology, National Defense Medical College, Tokorozawa, Saitama (Japan); Alabanza, Leah [Department of Medicine, University of Toledo, College of Medicine, Toledo, OH 43614 (United States); Chin, Khew-Voon, E-mail: khew-voon.chin@utoledo.edu [Department of Medicine, University of Toledo, College of Medicine, Toledo, OH 43614 (United States)

    2010-01-15

    The effects of cAMP in cell are predominantly mediated by the cAMP-dependent protein kinase (PKA), which is composed of two genetically distinct subunits, catalytic (C) and regulatory (R), forming a tetrameric holoenzyme R{sub 2}C{sub 2}. The only known function for the R subunit is that of inhibiting the activity of the C subunit kinase. It has been shown that overexpression of RI{alpha}, but not the C subunit kinase, is associated with neoplastic transformation. In addition, it has also been demonstrated that mutation in the RI{alpha}, but not the C subunit is associated with increased resistance to the DNA-damaging anticancer drug cisplatin, thus suggesting that the RI{alpha} subunit of PKA may have functions independent of the kinase. We show here that the RI{alpha} subunit interacts with a BTB/POZ domain zinc-finger transcription factor, PATZ1 (ZNF278), and co-expression with RI{alpha} results in its sequestration in the cytoplasm. The cytoplasmic/nuclear translocation is inducible by cAMP. C-terminus deletion abolishes PATZ1 interaction with RI{alpha} and results in its localization in the nucleus. PATZ1 transactivates the cMyc promoter and the presence of cAMP and co-expression with RI{alpha} modulates its transactivation. Moreover, PATZ1 is aberrantly expressed in cancer. Taken together, our results showed a potentially novel mechanism of cAMP signaling mediated through the interaction of RI{alpha} with PATZ1 that is independent of the kinase activity of PKA, and the aberrant expression of PATZ1 in cancer point to its role in cell growth regulation.

  14. Rescattering in the nucleus for π-d interactions at 15 GeV/c

    International Nuclear Information System (INIS)

    Porter, F.C.; Bingham, H.H.; Fretter, W.B.; Graves, W.R.; Yost, G.P.; Dunn, L.A.; Lubatti, H.J.; Moriyasu, K.

    1980-01-01

    We present the π - d charged multiplicity distributions at 15 GeV/c and examine the probability that the products of a π - n collision in a deuterium nucleus rescatter on the proton. Averaged over all topologies, this probability is 0.13 +- 0.02. The rescatter probability as a function of the number of charged particles produced in the π - n interaction exhibits an increase at high multiplicity

  15. Target dependence of K+-nucleus total cross sections

    International Nuclear Information System (INIS)

    Jiang, M.F.; Ernst, D.J.; Chen, C.M.

    1995-01-01

    We investigate the total cross section and its target dependence for K + -nucleus scattering using a relativistic momentum-space optical potential model which incorporates relativistically normalized wave functions, invariant two-body amplitudes, covariant kinematics, and an exact full-Fermi averaging integral. The definition of the total cross section in the presence of a Coulomb interaction is reviewed and the total cross section is calculated in a way that is consistent with what is extracted from experiment. In addition, the total cross sections for a nucleus and for the deuteron are calculated utilizing the same theory. This minimizes the dependence of the ratio of these cross sections on the details of the theory. The model dependence of the first-order optical potential calculations is investigated. The theoretical results are found to be systematically below all existing data

  16. Experimental studies of nucleon-nucleon and pion-nucleus interactions at intermediate energies: Final report

    International Nuclear Information System (INIS)

    Burleson, G.R.

    1987-01-01

    We are applying for a three-year grant from the US Department of Energy to New Mexico State University to continue its support of our work on experimental studies of nucleon-nucleon and pion-nucleus interactions at intermediate energies, which has been carried out in collaboration with groups from various laboratories and universities. The nucleon-nucleon work is aimed at making measurements that will contribute to a determination of the isospin-zero amplitudes, as well as continuing our investigations of evidence for dibaryon resonances. It is based at the LAMPF accelerator in Los Alamos, New Mexico. Current and planned experiments include measurements of total cross-section differences in pure spin states and of spin parameters in neutron-proton scattering. The pion-nucleus work is aimed at improving our understanding both of the nature of the pion-nucleus interaction and of nuclear structure. It consists of two programs, one based at LAMPF and one based principally at the SIN laboratory in Switzerland. The LAMPF-based work involves studies of large-angle scattering, double-charge-exchange scattering, including measurements at a new energy range above 300 MeV, and a new program of experiments with polarized nuclear targets. The SIN-based work involves studies of quasielastic scattering and absorption, including experiments with a new large-acceptance detector system planned for construction there. We are requesting support to continue the LAMPF-based work at its current level and to expand the SIN-based work to allow for increased involvement in experiments with the new detector system. 57 refs

  17. Interactive session: alpha emitters, fashion or reality? radionuclides and molecules availability

    International Nuclear Information System (INIS)

    Zimmermann, R.

    2015-01-01

    Full text of publication follows. This introduction to the interactive session will simply be based on statements related to the future of therapy in nuclear medicine with some emphasis on the use of alpha-emitters. Some hypotheses will be developed on topics such as 'How will look nuclear medicine in 2025?', 'Do we have enough information to support the use of alpha in therapy?' 'Does it make sense to develop alpha-labelled molecules without long term financial commitment?', 'Will sufficient amounts of radionuclides available when the drugs will be ready for marketing?', 'Do we know enough about alpha emitters toxicity?', 'Is personalized medicine really the solution of the future of health care?', 'How can we convince authorities about the advantages of alpha labelled molecules?', 'Is the development of alpha RIT more expensive or more difficult than beta RIT?', 'Where are all the beta-emitter under development gone?', 'With alpha-emitters, are we speaking about 2025 or 2050?', 'Will Xofigo be a success?', 'What will be the real role of pharmaceutical companies in radiotherapy?', 'Who are the most afraid about radioactivity, the patients or the authorities?'. The speaker will provide his own opinion about each topic. Will you agree or not with him? What is your opinion? (author)

  18. Energy loss, range and fluence distributions, total reaction and projectile fragment production cross sections for proton-nucleus and nucleus-nucleus interactions

    International Nuclear Information System (INIS)

    Sihver, L.; Kanai, T.

    1992-07-01

    We have developed a computer code for calculations of energy loss (dE/dx) and range distributions for heavy ions in any media. The results from our calculations are in very good agreement with previous calculations. We have developed semiempirical total reaction cross section formulae for proton-nucleus (with Z p ≤26) and nucleus-nucleus (with Z p and Z t ≤26) reactions. These formulae apply for incident energies above 15 MeV and 100 MeV/nucleon respectively. From the total reaction cross sections, we can calculate the mean free paths and the fluence distributions of protons and heavy ions in any media. We have compared all the calculated reaction cross sections and the mean free paths with experimental data, and the agreement is good. We have also constructed a procedure for calculating projectile fragment production cross sections, by scaling semiempirical proton-nucleus partial cross section systematics. The scaling is performed using a scaling parameter deduced from our reaction cross sections formulae, and additional enhancements factors. All products with atomic number ranging from that of the projectile (Z p ) down to Z=2 can be calculated. The agreement between the calculated cross sections and the experimental data is better than earlier published results. (author)

  19. Optical potentials derived from microscopic separable interactions including binding and recoil effects

    International Nuclear Information System (INIS)

    Siciliano, E.R.; Walker, G.E.

    1976-01-01

    We first consider a projectile scattering from a nucleon bound in a fixed potential. A separable Galilean invariant projectile-nucleon interaction is adopted. Without using the fixed scatterer approximation or using closure on the intermediate target nucleon states we obtain various forms for the projectile-bound nucleon t matrix. Effects due to intermediate target excitation and nucleon recoil are discussed. By making the further approximations of closure and fixed scatterers we make connection with the work of previous authors. By generalizing to projectile interaction with several bound nucleons and examining the appropriate multiple scattering series we identify the optical potential for projectile elastic scattering from the many-body system. Different optical potentials are obtained for different projectile-bound nucleon t matrices, and we study the differences predicted by these dissimilar optical potentials for elastic scattering. In a model problem, we study pion-nucleus elastic scattering and compare the predictions obtained by adopting procedures used by (1) Landau, Phatak, and Tabakin and (2) Piepho-Walker to the predictions obtained in a less restrictive, but computationally difficult treatment

  20. Spin-dependent level density in interacting Boson-Fermion-Fermion model of the Odd-Odd Nucleus 196Au

    International Nuclear Information System (INIS)

    Kabashi, S.; Bekteshi, S.; Ahmetaj, S.; Shaqiri, Z.

    2009-01-01

    The level density of the odd-odd nucleus 196 Au is investigated in the interacting boson-fermion-fermion model (IBFFM) which accounts for collectivity and complex interaction between quasiparticle and collective modes.The IBFFM spin-dependent level densities show high-spin reduction with respect to Bethe formula.This can be well accounted for by a modified spin-dependent level density formula. (authors)

  1. Momentum dependence of the imaginary part of the ω- and η{sup '}-nucleus optical potential

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, S.; Nanova, M.; Metag, V.; Brinkmann, K.T.; Drexler, P.; Gutz, E.; Makonyi, K.; Zaunick, H.G. [Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Afzal, F.N.; Beck, R.; Becker, M.; Boese, S.; Funke, C.; Gottschall, M.; Gruener, M.; Hammann, C.; Hartmann, J.; Hoffmeister, P.; Honisch, C.; Kaiser, D.; Kalischewski, F.; Koop, K.; Lang, M.; Mueller, J.; Muellers, J.; Piontek, D.M.; Schaab, D.; Schmidt, C.; Schmitz, R.; Seifen, T.; Sokhoyan, V.; Spieker, K.; Thiel, A.; Thoma, U.; Urban, M.; Pee, H. van; Walther, D.; Wendel, C.; Wilson, A.; Wunderlich, Y. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Bayadilov, D. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Bantes, B.; Eberhardt, H.; Elsner, D.; Frommberger, F.; Hannappel, J.; Hillert, W.; Jude, T.; Klein, F.; Messi, F.; Schmieden, H. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany); Crede, V. [Florida State University, Department of Physics, Tallahassee, FL (United States); Keshelashvili, I.; Krusche, B.; Rostomyan, T.; Werthmueller, D.; Witthauer, L. [Universitaet Basel, Departement Physik, Basel (Switzerland); Sowa, C.; Triffterer, T.; Wiedner, U. [Universitaet Bochum, Physikalisches Institut, Bochum (Germany); Collaboration: The CBELSA/TAPS Collaboration

    2016-09-15

    The photoproduction of ω and η{sup '} mesons off carbon and niobium nuclei has been measured as a function of the meson momentum for incident photon energies of 1.2-2.9 GeV at the electron accelerator ELSA. The mesons have been identified via the ω → π{sup 0}γ → 3γ and η{sup '} → π{sup 0}π{sup 0}η → 6γ decays, respectively, registered with the CBELSA/TAPS detector system. From the measured meson momentum distributions the momentum dependence of the transparency ratio has been determined for both mesons. Within a Glauber analysis the in-medium ω and η{sup '} widths and the corresponding absorption cross sections have been deduced as a function of the meson momentum. The results are compared to recent theoretical predictions for the in-medium ω width and η{sup '}-N absorption cross sections. The energy dependence of the imaginary part of the ω- and η{sup '}-nucleus optical potential has been extracted. The finer binning of the present data compared to the existing data allows a more reliable extrapolation towards the production threshold. The modulus of the imaginary part of the η{sup '}-nucleus potential is found to be about three times smaller than recently determined values of the real part of the η{sup '}-nucleus potential, which makes the η{sup '} meson a suitable candidate for the search for meson-nucleus bound states. For the ω meson, the modulus of the imaginary part near threshold is comparable to the modulus of the real part of the potential. As a consequence, only broad structures can be expected, which makes the observation of ω mesic states very difficult experimentally. (orig.)

  2. Matrix metalloproteinase 3 promotes cellular anti-dengue virus response via interaction with transcription factor NFκB in cell nucleus.

    Science.gov (United States)

    Zuo, Xiangyang; Pan, Wen; Feng, Tingting; Shi, Xiaohong; Dai, Jianfeng

    2014-01-01

    Dengue virus (DENV), the causative agent of human Dengue hemorrhagic fever, is a mosquito-borne virus of immense global health importance. Characterization of cellular factors promoting or inhibiting DENV infection is important for understanding the mechanism of DENV infection. In this report, MMP3 (stromelysin-1), a secretory endopeptidase that degrades extracellular matrices, has been shown promoting cellular antiviral response against DENV infection. Quantitative RT-PCR and Western Blot showed that the expression of MMP3 was upregulated in DENV-infected RAW264.7 cells. The intracellular viral loads were significantly higher in MMP3 silenced cells compared with controls. The expression level of selective anti-viral cytokines were decreased in MMP3 siRNA treated cells, and the transcription factor activity of NFκB was significantly impaired upon MMP3 silencing during DENV infection. Further, we found that MMP3 moved to cell nucleus upon DENV infection and colocalized with NFκB P65 in nucleus. Co-immunoprecipitation analysis suggested that MMP3 directly interacted with NFκB in nucleus during DENV infection and the C-terminal hemopexin-like domain of MMP3 was required for the interaction. This study suggested a novel role of MMP3 in nucleus during viral infection and provided new evidence for MMPs in immunomodulation.

  3. Color oscillations of nucleons in a nucleus

    International Nuclear Information System (INIS)

    Petrov, V.A.; Smirnov, A.Yu.

    1987-01-01

    Possibility of nucleus description as an object consisting of quarks and gluons is considered. A model of two-nucleon interaction in a nucleus is presented and analytical expressions for the nucleus nucleon ground state wave functions and also for nuclear nucleon structure functions are obtained. The carried out analysis shows that the suggested model permits to express the nucleus structure functions at quark level only by means of nucleon and Δ-isobaric degrees of freedom

  4. New aspects of the atomic nucleus

    International Nuclear Information System (INIS)

    Wilkinson, D.H.

    1987-01-01

    We are at last just beginning to identify convincing evidence for what we have long believed, namely that the nucleus is more than the sum of its neutron-proton parts taken pairwise because, for example, a cluster of three nucleons interacts differently from the sum of the interactions of its three pairs; there is an important collectivism in the life of a nucleus even before we ask what its nucleons are doing. (orig./WL)

  5. The nucleus

    International Nuclear Information System (INIS)

    Marano, S.

    1998-01-01

    In 1911 E.Rutherford discovered the nucleus. Since then the nucleus has been investigated with more and more powerful tools but it remains the main field of study of nuclear physics. As it is impossible to take into account the interaction of all the nucleons, a theory based on the hypothesis that each nucleon undergoes an average interaction force has been set up. 2 representations have emerged: the Skyrme force and the Gogny force. Both representations match experimental results but are unable to describe fission yields or the multi-fragmentation of very hot nuclei. The mean-field theory can predict the shape of the nuclei according to its energy level. An experimental program involving the Vivitron accelerator and the Euroball detector is due to begin to validate it. By bombarding targets with exotic nuclei nuclear physicists detect new structures and test their collision models. About ten years ago nuclear halos were observed with lithium 11 nuclei. In this nucleus 2 neutrons move in a space larger than the nucleus itself. This discovery has triggered the elaboration of new theories based on nuclear clusters. At very high temperatures the mean-field theory predicts that nuclear matter acts as a fluid. Following the nuclei temperature different ways of decay appear: first evaporation then multi-fragmentation and vaporization. This ultimate stage occurs around 100 milliard celsius degree temperature when the nuclei decays in a multitude of light particles. Isomeric states are studied and could be seen as a way of storing energy. In a very pedagogical way this article gives information to understand the challenges that face nuclear physics today and highlights the contributions of Cea in this field. (A.C.)

  6. Energy deposition and GDR emission in inelastic alpha particle scattering

    CERN Document Server

    Viesti, G; Fabris, D; Nebbia, G; Cinausero, M; Fioretto, E; Napoli, D R; Prete, G; Hagel, K; Natowitz, J B; Wada, R; Gonthier, P; Majka, Z; Alfarro, R; Zhao, Y; Mdeiwayeh, N; Ho, T

    1999-01-01

    Neutron fold distributions measured for the reaction sup 2 sup 0 sup 9 Bi(alpha,alpha') at 240 MeV have been analyzed with the help of Statistical Model calculations to determine the distribution of excitation energy in the primary target fragments as a function of the projectile energy loss, EL. Results show that the distributions in excitation energy feature a plateau which extends from the kinematical limit E sub x =EL to very small excitations, suggesting a variety of interactions of the beam particles with the target nucleus. Requiring an additional coincidence with a light charged particle leads to selection of a significant higher average excitation energy. This effect is extrapolated to explore results of previous GDR decay measurements in the case of a sup 2 sup 0 sup 8 Pb target. Corrections of derived GDR parameters due to the partial transfer of excitation energy are suggested.

  7. Low and intermediate energy pion-nucleus interactions in the cascade-exciton model

    International Nuclear Information System (INIS)

    Mashnik, S.G.

    1993-01-01

    A large variety of experimental data on pion-nucleus interactions in the bombarding energy range of 0-3000 MeV, on nucleon-induced pion production and on cumulative nucleon production, when a two-step process of pion production followed by absorption on nucleon pairs within a target is taken into account, are analyzed with the Cascade-Exciton Model of nuclear reactions.Comparison is made with other up-to-date models of these processes. The contributions of different pion absorption mechanisms and the relative role of different particle production mechanisms in these reactions are discussed

  8. Measurement of 19F nucleus interaction at 4 GeV/c per nucleon

    International Nuclear Information System (INIS)

    Golovin, V.M.; Golutvin, I.A.; Dolya, S.N.

    1986-01-01

    The cross sections of 19 F nucleus interaction with the nuclei of different elements at 4 GeV/c x nucleon momentum in reactions are measured. In the finite state of these reactions the fragment with charge Z≤8 is formed. The experiment apparatus comprises a transmission detector where the nuclei trajectory at the target input has been measured with proportional chambers whereas the nuclear charge before and after the target has been measured by Cherenkov counters. Experimental data obtained with accuracy - 2% are presented for carbon, aluminium, copper, indium, tungsten, bismuth and uranium targets. The dependence of cross sections on atomic number of the target coincides except of cross section of interaction with heavy targets

  9. Progress in the development of global medium-energy nucleon-nucleus optical model potentials

    International Nuclear Information System (INIS)

    Madland, D.G.

    1997-01-01

    Two existing global medium-energy nucleon-nucleus phenomenological optical model potentials are described and compared with experiment and with each other. The first of these employs a Dirac approach (second-order reduction) that is global in projectile energy and projectile isospin and applies to the target nucleus 208 Pb. The second of these employs a relativistic equivalent to the Schroedinger equation (including relativistic kinematics) that is global in projectile energy, projectile isospin, and target (Z,A). Finally, current work is described and the influence of the nuclear bound state problem (treated in relativistic mean field theory) on the Dirac scattering problem is mentioned. Spherical target nuclei are treated in the present work and strongly-collective target nuclei (rotational and vibrational) requiring coupled-channels approaches will be treated in a future paper. (author)

  10. On the imaginary part of the S-wave pion-nucleus optical potential

    International Nuclear Information System (INIS)

    Germond, J.F.; Lombard, R.J.

    1991-01-01

    The contribution of pion absorption to the imaginary part of the S-wave pion-nucleus optical potential is calculated with Slater determinantal antisymmetrized nuclear wave funtions, taking fully into accout the spin and isospin degrees of freedom. The potential obtained has an explicit dependence on the proton and neutron nuclear densities whose coefficients are directly related to the two-nucleon absorption coupling constants. The values of these coefficients extracted from mesic atoms data are in good agreement with those deduced from exclusive pion absorption experiments in 3 He, but larger than the predictions of the pion rescattering model. (orig.)

  11. Asymptotic value of screening parameter as determined from the one-electron fragment of the kinetic energy or electrostatic potential at the nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Teruya, Hirohide; Anno, Tosinobu

    1985-09-01

    Numerical value of lim sub(Z ..-->.. infinity) delta(i, j)/delta Zsub(i), where (i, j) stands for average interaction energy of a pair of electrons embedded in hydrogenic orbitals (HAO's) is presented for a wide range of HAO's. Data to be presented should be useful to calculate the asymptotic limit of screening effect seen by an electron embedded in a given kind of orbital for an isoelectronic series of atoms as determined from the ''one-electron component'' of the total kinetic energy of or of the electrostatic potential at the nucleus within an atom.

  12. Constraints on Σ nucleus dynamics from dirac phenomenology of Σ- atoms

    International Nuclear Information System (INIS)

    Mares, J.; Friedman, E.; Hebrew Univ., Jerusalem; Gal, A.; Jennings, B.K.

    1995-05-01

    Strong interaction level shifts and widths in Σ - atoms are analyzed by using a Σ nucleus optical potential constructed within the relativistic mean field approach. The analysis leads to potentials with a repulsive real part in the nuclear interior. The data are sufficient to establish the size of the isovector meson-hyperon coupling. Implications to Σ hypernuclei are discussed. (author). 36 refs., 2 tabs., 4 figs

  13. On the possible detection of quantum-mechanical interferences between gravitational forces and nucleus-nucleus Coulomb forces

    International Nuclear Information System (INIS)

    Silveira, R. da

    1996-07-01

    Possible effects of quantum-mechanical interferences between gravitational forces and the nucleus-nucleus Coulomb interaction are discussed. It is shown that, although very small, these effects could be measured using low energy scattering between identical heavy nuclei, e.g. for the system 208 Pb + 208 Pb (E L = 5 MeV). (author)

  14. The Changes of Energy Interactions between Nucleus Function and Mitochondria Functions Causing Transmutation of Chronic Inflammation into Cancer Metabolism.

    Science.gov (United States)

    Ponizovskiy, Michail R

    2016-01-01

    Interactions between nucleus and mitochondria functions induce the mechanism of maintenance stability of cellular internal energy according to the first law of thermodynamics in able-bodied cells and changes the mechanisms of maintenance stability of cellular internal energy creating a transition stationary state of ablebodied cells into quasi-stationary pathologic states of acute inflammation transiting then into chronic inflammation and then transmuting into cancer metabolism. The mechanisms' influences of intruding etiologic pathologic agents (microbe, virus, etc.) lead to these changes of energy interactions between nucleus and mitochondria functions causing general acute inflammation, then passing into local chronic inflammation, and reversing into cancer metabolism transmutation. Interactions between biochemical processes and biophysical processes of cellular capacitors' operations create a supplementary mechanism of maintenance stability of cellular internal energy in the norm and in pathology. Discussion of some scientific works eliminates doubts of the authors of these works.

  15. Elastic scattering of protons on 8Li nucleus in inverse kinematics

    International Nuclear Information System (INIS)

    Zhusupov, M.A.; Ibraeva, E.T.; Sanfirova, A.B.; Imambekov, O.

    2002-01-01

    In the present paper the proton elastic scattering on 8 Li in inverse kinematics is studies. The inverse kinematics means that a beam of radioactive nuclei is scattered on a stable hydrogen target. Proton as a target has an advantage during the interaction since it is stable and mechanism of proton-nucleus scattering is quite simple. 8 Li nucleus is considered in the three-body αtn-model with realistic potential of inter-cluster interactions. The wave function of this nucleus is calculated in the work where it was shown that such model well describes the main spectroscopic characteristics of the nucleus, root-mean square radius, binding energy, location of low laying energy levels, magnetic momentum and also total cross section and 7 Li(n, γ) 8 Li reaction rate at a wide energy region. Within Glauber-Sitenko multiply scattering theory, the differential cross section of elastic p 8 Li-scattering has been calculated. The first and the second multiplicities of scattering on nucleons and clusters of the nucleus were taken into account in Ω multiply scattering operator. There were considered several cases when as the initial parameters both amplitudes of nucleon-nucleon and nucleon-cluster scattering were taken. Sensitivity of the differential cross section both to the different wave functions of the target-nucleus and to the parameters of the elementary amplitudes and sensitivity to the scattering multiplicities at several beam energies has been investigated. Comparison with differential cross sections of elastic p 6 Li- and p 7 Li scattering has been carried out

  16. Interaction of the Mouse Polyomavirus Capsid Proteins with Importins Is Required for Efficient Import of Viral DNA into the Cell Nucleus.

    Science.gov (United States)

    Soldatova, Irina; Prilepskaja, Terezie; Abrahamyan, Levon; Forstová, Jitka; Huérfano, Sandra

    2018-03-31

    The mechanism used by mouse polyomavirus (MPyV) overcomes the crowded cytosol to reach the nucleus has not been fully elucidated. Here, we investigated the involvement of importin α/β1 mediated transport in the delivery of MPyV genomes into the nucleus. Interactions of the virus with importin β1 were studied by co-immunoprecipitation and proximity ligation assay. For infectivity and nucleus delivery assays, the virus and its capsid proteins mutated in the nuclear localization signals (NLSs) were prepared and produced. We found that at early times post infection, virions bound importin β1 in a time dependent manner with a peak of interactions at 6 h post infection. Mutation analysis revealed that only when the NLSs of both VP1 and VP2/3 were disrupted, virus did not bind efficiently to importin β1 and its infectivity remarkably decreased (by 80%). Nuclear targeting of capsid proteins was improved when VP1 and VP2 were co-expressed. VP1 and VP2 were effectively delivered into the nucleus, even when one of the NLS, either VP1 or VP2, was disrupted. Altogether, our results showed that MPyV virions can use VP1 and/or VP2/VP3 NLSs in concert or individually to bind importins to deliver their genomes into the cell nucleus.

  17. Hyperfine interaction of {sup 25}Al in {alpha}-Al{sub 2}O{sub 3} and its quadrupole moment

    Energy Technology Data Exchange (ETDEWEB)

    Matsuta, K., E-mail: matsuta@vg.phys.sci.osaka-u.ac.jp; Mihara, M. [Osaka University, Department of Physics (Japan); Nagatomo, T. [RIKEN (Japan); Matsumiya, R. [Osaka University, Department of Physics (Japan); Momota, S. [Kochi University of Technology (Japan); Ohtsubo, T. [Niigata University, Department of Physics (Japan); Izumikawa, T. [Niigata University, Radioisotope Center (Japan); Hirano, H.; Takahashi, S. [Niigata University, Department of Physics (Japan); Nishimura, D.; Komurasaki, J. [Osaka University, Department of Physics (Japan); Kitagawa, A.; Kanazawa, M.; Torikoshi, M.; Sato, S. [National Institute of Radiological Sciences (Japan); Fukuda, M. [Osaka University, Department of Physics (Japan); Minamisono, T. [Fukui University of Technology (Japan); Sumikama, T. [Tokyo University of Science (Japan); Tanaka, K.; Takechi, M. [RIKEN (Japan)

    2007-11-15

    The electric quadrupole (Q) moment of short-lived nucleus {sup 25}Al (I{sup {pi}} = 5/2{sup +}, T{sub 1/2} = 7.18 s) has been measured for the first time, by means of the {beta}-NQR technique. The spin polarization of {sup 25}Al was produced in heavy ion collisions and was kept in a {alpha}-Al{sub 2}O{sub 3} single crystal for as long as 2 s and the quadrupole coupling frequency was obtained as vertical bar eqQ / h({sup 25}Al in Al{sub 2}O{sub 3}) vertical bar = (4.05 {+-}0.30) MHz. From the result, the Q moment was determined as |Q({sup 25}Al)| = (240 {+-}20) mb. The present Q moment is larger by 30% than the shell model value of 184 mb, calculated by OXBASH code, which may show additional deformation of the nucleus.

  18. Momentum loss in proton-nucleus and nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Khan, F.; Townsend, L.W.

    1993-12-01

    An optical model description, based on multiple scattering theory, of longitudinal momentum loss in proton-nucleus and nucleus-nucleus collisions is presented. The crucial role of the imaginary component of the nucleon-nucleon transition matrix in accounting for longitudinal momentum transfer is demonstrated. Results obtained with this model are compared with Intranuclear Cascade (INC) calculations, as well as with predictions from Vlasov-Uehling-Uhlenbeck (VUU) and quantum molecular dynamics (QMD) simulations. Comparisons are also made with experimental data where available. These indicate that the present model is adequate to account for longitudinal momentum transfer in both proton-nucleus and nucleus-nucleus collisions over a wide range of energies

  19. DISCOVERY OF A FLAT-SPECTRUM RADIO NUCLEUS IN NGC 3115

    Energy Technology Data Exchange (ETDEWEB)

    Wrobel, J. M. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); Nyland, K., E-mail: jwrobel@nrao.edu, E-mail: knyland@nrao.edu [New Mexico Tech, Department of Physics, 801 Leroy Place, Socorro, NM 87801 (United States)

    2012-12-01

    The early-type galaxy NGC 3115, at a distance of 10.2 Mpc, hosts the nearest billion-solar-mass black hole. Wong et al. recently inferred a substantial Bondi accretion rate near the black hole. Bondi-like accretion is thought to fuel outflows, which can be traced through their radio emission. This paper reports the discovery of a radio nucleus in NGC 3115, with a diameter less than 0.''17 (8.4 pc), a luminosity at 8.5 GHz of 3.1 Multiplication-Sign 10{sup 35} erg s{sup -1}, and a flat spectrum ({alpha} = -0.23 {+-} 0.20, S{proportional_to}{nu}{sup {alpha}}). The radio source coincides with the galaxy's photocenter and candidate X-ray nucleus. The emission is radio loud, suggesting the presence of an outflow on scales less than 10 pc. On such scales, the Bondi accretion could be impeded by heating due to disruption of the outflow.

  20. Characterization of the primary interaction between the mating pheromone, alpha-factor, and its receptor in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Raths, S.K.

    1987-01-01

    Alpha-factor is a peptide of thirteen amino acids which is required for mating between the haploid mating types, a and α, in Saccharomyces cerevisiae. An analogue of alpha-factor, DHP 8 DHP 11 Nle 12 tridecapeptide, was catalytically reduced in the presence of 3 H gas for production of a radiolabeled pheromone suitable for use in binding studies. Incorporation of tritium resulted in 3 H-alpha-factor with high specific activity, purity, biological activity and long shelf-life. Binding studies revealed that alpha-factor interacts with its receptor via a simple, reversible process which obeys the law of mass action. Association and dissociation kinetics indicate values of 2.92 x 10 6 M/sup /minus/1/ min -1 for k 1 and between 4 and 7 x 10/sup /minus/2/ min/sup /minus/1/ for k/sub /minus/1/. Saturation binding studies reveal an equilibrium dissociation constant equal to 2.32 x 10/sup /minus/8/ M which approximate the kinetically-derived K/sub D/ of 2.12 x 10/sup /minus/8/ M. Scatchard and Hill analyses as well as dissociation behavior in the presence of excess unlabeled ligand indicate alpha-factor interacts with a homogeneous population of binding sites which do not interact and exhibit one affinity for the alpha-factor pheromone

  1. Study of the superdeformed states of the gadolinium nuclei: neutron excitations in {sup 147}Gd nucleus; Etude des etats superdeformes de noyaux de Gadolinium: Excitations neutron dans le noyau {sup 147}Gd

    Energy Technology Data Exchange (ETDEWEB)

    Khadiri, Najia [Institut de Recherche Subatomique, CNRS-IN2P3 - Universite Louis Pasteur, 67 - Strasbourg (France)

    1997-10-17

    This work is devoted to nuclear structure studies of superdeformed states in the second potential well. Under focus are the gadolinium isotopes and in particular the {sup 147}Gd nucleus. High spin states in {sup 147}Gd have been populating by {sup 122}Sn ({sup 30}Si,5n){sup 147}Gd fusion-evaporation reaction with a silicon beam of 158 MeV delivered by the VIVITRON accelerator of the Institut de Recherches Subatomiques. The nucleus {gamma} de-excitations have been measured using the EUROGAM II {gamma}-ray multidetector. On the basis of multiple coincidences, four new superdeformed (SD) rotational bands have been assigned to {sup 147}Gd nucleus. Nuclear structures corresponding to these bands have been investigated by shell model calculations using a harmonic oscillator potential with cranking, in the Nilsson Strutinsky formalism. Comparison of dynamical moments of inertia of band (1) and (5) in {sup 147}Gd with {sup 148}Gd(2) and {sup 146}Gd(1) SD bands has fixed the role of the [651 1/2]{alpha} = -1/2 orbital crossing frequency. Theoretical calculations reproduce quite well the {sup 148}Gd(2), {sup 127}Gd(1,5) and G{sup 146}Gd(1) dynamical moments of inertia. Using the particle hole excitation nature of {sup 149,148,147,146}Gd bands, effective spin alignment of [651 1/2]{alpha}= {+-}1/2, [770 1/2]{alpha} = -1/2 and [441 1/2]{alpha} = +1/2 orbitals have been deduced from the experiment in agreement with the theoretical values. Of particular interest, the spin alignment measured for the [441 1/2]{alpha} +1/2 orbital, with a value close to zero, is in contradiction with the value predicted by the Pseudo SU(3) model, formalism often used to explain the identical band phenomenon. (author) 68 refs., 41 figs., 17 tabs.

  2. Nuclear re-interaction effects in quasi-elastic neutrino nucleus scattering

    Energy Technology Data Exchange (ETDEWEB)

    Co, G.; Bleve, C.; De Mitri, I.; Martello, D

    2002-11-01

    The quasi-elastic {nu}-nucleus cross section has been calculated by using a Fermi gas model corrected to consider the re-scattering between the emitted nucleon and the rest nucleus. As an example of the relevance of this effect we show results for the muon production cross section on {sup 16}O target.

  3. Amphetamine elevates nucleus accumbens dopamine via an action potential-dependent mechanism that is modulated by endocannabinoids

    Science.gov (United States)

    Covey, Dan P.; Bunner, Kendra D.; Schuweiler, Douglas R.; Cheer, Joseph F.; Garris, Paul A.

    2018-01-01

    The reinforcing effects of abused drugs are mediated by their ability to elevate nucleus accumbens dopamine. Amphetamine (AMPH) was historically thought to increase dopamine by an action potential-independent, non-exocytotic type of release called efflux, involving reversal of dopamine transporter function and driven by vesicular dopamine depletion. Growing evidence suggests that AMPH also acts by an action potential-dependent mechanism. Indeed, fast-scan cyclic voltammetry demonstrates that AMPH activates dopamine transients, reward-related phasic signals generated by burst firing of dopamine neurons and dependent on intact vesicular dopamine. Not established for AMPH but indicating a shared mechanism, endocannabinoids facilitate this activation of dopamine transients by broad classes of abused drugs. Here, using fast-scan cyclic voltammetry coupled to pharmacological manipulations in awake rats, we investigated the action potential and endocannabinoid dependence of AMPH-induced elevations in nucleus accumbens dopamine. AMPH increased the frequency, amplitude and duration of transients, which were observed riding on top of slower dopamine increases. Surprisingly, silencing dopamine neuron firing abolished all AMPH-induced dopamine elevations, identifying an action potential-dependent origin. Blocking cannabinoid type 1 receptors prevented AMPH from increasing transient frequency, similar to reported effects on other abused drugs, but not from increasing transient duration and inhibiting dopamine uptake. Thus, AMPH elevates nucleus accumbens dopamine by eliciting transients via cannabinoid type 1 receptors and promoting the summation of temporally coincident transients, made more numerous, larger and wider by AMPH. Collectively, these findings are inconsistent with AMPH eliciting action potential-independent dopamine efflux and vesicular dopamine depletion, and support endocannabinoids facilitating phasic dopamine signalling as a common action in drug reinforcement

  4. Amphetamine elevates nucleus accumbens dopamine via an action potential-dependent mechanism that is modulated by endocannabinoids.

    Science.gov (United States)

    Covey, Dan P; Bunner, Kendra D; Schuweiler, Douglas R; Cheer, Joseph F; Garris, Paul A

    2016-06-01

    The reinforcing effects of abused drugs are mediated by their ability to elevate nucleus accumbens dopamine. Amphetamine (AMPH) was historically thought to increase dopamine by an action potential-independent, non-exocytotic type of release called efflux, involving reversal of dopamine transporter function and driven by vesicular dopamine depletion. Growing evidence suggests that AMPH also acts by an action potential-dependent mechanism. Indeed, fast-scan cyclic voltammetry demonstrates that AMPH activates dopamine transients, reward-related phasic signals generated by burst firing of dopamine neurons and dependent on intact vesicular dopamine. Not established for AMPH but indicating a shared mechanism, endocannabinoids facilitate this activation of dopamine transients by broad classes of abused drugs. Here, using fast-scan cyclic voltammetry coupled to pharmacological manipulations in awake rats, we investigated the action potential and endocannabinoid dependence of AMPH-induced elevations in nucleus accumbens dopamine. AMPH increased the frequency, amplitude and duration of transients, which were observed riding on top of slower dopamine increases. Surprisingly, silencing dopamine neuron firing abolished all AMPH-induced dopamine elevations, identifying an action potential-dependent origin. Blocking cannabinoid type 1 receptors prevented AMPH from increasing transient frequency, similar to reported effects on other abused drugs, but not from increasing transient duration and inhibiting dopamine uptake. Thus, AMPH elevates nucleus accumbens dopamine by eliciting transients via cannabinoid type 1 receptors and promoting the summation of temporally coincident transients, made more numerous, larger and wider by AMPH. Collectively, these findings are inconsistent with AMPH eliciting action potential-independent dopamine efflux and vesicular dopamine depletion, and support endocannabinoids facilitating phasic dopamine signalling as a common action in drug reinforcement

  5. Antiproton production in nucleon-nucleus and nucleus-nucleus collisions at the CERN-SPS

    International Nuclear Information System (INIS)

    Kadija, K.; Schmitz, N.; Seyboth, P.

    1996-01-01

    A model for antiproton production in nucleon-nucleus and nucleus-nucleus collisions at 200 GeV per nucleon, based on the wounded nucleon model is developed. The predictions are compared to published nucleon-nucleus and sulphur-nucleus data. The results suggest the presence of similar antiproton production processes in nucleon-nucleus and nucleus-nucleus collisions near midrapidity. (orig.)

  6. S-matrix to potential inversion of low-energy. alpha. - sup 12 C phase shifts

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, S.G.; Mackintosh, R.S. (Open Univ., Milton Keynes (UK). Dept. of Physics)

    1990-10-22

    The IP S-matrix to potential inversion procedure is applied to phase shifts for selected partial waves over a range of energies below the inelastic threshold for {alpha}-{sup 12}C scattering. The phase shifts were determined by Plaga et al. Potentials found by Buck and Rubio to fit the low-energy alpha cluster resonances need only an increased attraction in the surface to accurately reproduce the phase-shift behaviour. Substantial differences between the potentials for odd and even partial waves are necessary. The surface tail of the potential is postulated to be a threshold effect. (orig.).

  7. Nucleus-Nucleus Collision as Superposition of Nucleon-Nucleus Collisions

    International Nuclear Information System (INIS)

    Orlova, G.I.; Adamovich, M.I.; Aggarwal, M.M.; Alexandrov, Y.A.; Andreeva, N.P.; Badyal, S.K.; Basova, E.S.; Bhalla, K.B.; Bhasin, A.; Bhatia, V.S.; Bradnova, V.; Bubnov, V.I.; Cai, X.; Chasnikov, I.Y.; Chen, G.M.; Chernova, L.P.; Chernyavsky, M.M.; Dhamija, S.; Chenawi, K.El; Felea, D.; Feng, S.Q.; Gaitinov, A.S.; Ganssauge, E.R.; Garpman, S.; Gerassimov, S.G.; Gheata, A.; Gheata, M.; Grote, J.; Gulamov, K.G.; Gupta, S.K.; Gupta, V.K.; Henjes, U.; Jakobsson, B.; Kanygina, E.K.; Karabova, M.; Kharlamov, S.P.; Kovalenko, A.D.; Krasnov, S.A.; Kumar, V.; Larionova, V.G.; Li, Y.X.; Liu, L.S.; Lokanathan, S.; Lord, J.J.; Lukicheva, N.S.; Lu, Y.; Luo, S.B.; Mangotra, L.K.; Manhas, I.; Mittra, I.S.; Musaeva, A.K.; Nasyrov, S.Z.; Navotny, V.S.; Nystrand, J.; Otterlund, I.; Peresadko, N.G.; Qian, W.Y.; Qin, Y.M.; Raniwala, R.; Rao, N.K.; Roeper, M.; Rusakova, V.V.; Saidkhanov, N.; Salmanova, N.A.; Seitimbetov, A.M.; Sethi, R.; Singh, B.; Skelding, D.; Soderstrem, K.; Stenlund, E.; Svechnikova, L.N.; Svensson, T.; Tawfik, A.M.; Tothova, M.; Tretyakova, M.I.; Trofimova, T.P.; Tuleeva, U.I.; Vashisht, Vani; Vokal, S.; Vrlakova, J.; Wang, H.Q.; Wang, X.R.; Weng, Z.Q.; Wilkes, R.J.; Yang, C.B.; Yin, Z.B.; Yu, L.Z.; Zhang, D.H.; Zheng, P.Y.; Zhokhova, S.I.; Zhou, D.C.

    1999-01-01

    Angular distributions of charged particles produced in 16 O and 32 S collisions with nuclear track emulsion were studied at momenta 4.5 and 200 A GeV/c. Comparison with the angular distributions of charged particles produced in proton-nucleus collisions at the same momentum allows to draw the conclusion, that the angular distributions in nucleus-nucleus collisions can be seen as superposition of the angular distributions in nucleon-nucleus collisions taken at the same impact parameter b NA , that is mean impact parameter between the participating projectile nucleons and the center of the target nucleus

  8. Nucleus-Nucleus Collision as Superposition of Nucleon-Nucleus Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Orlova, G I; Adamovich, M I; Aggarwal, M M; Alexandrov, Y A; Andreeva, N P; Badyal, S K; Basova, E S; Bhalla, K B; Bhasin, A; Bhatia, V S; Bradnova, V; Bubnov, V I; Cai, X; Chasnikov, I Y; Chen, G M; Chernova, L P; Chernyavsky, M M; Dhamija, S; Chenawi, K El; Felea, D; Feng, S Q; Gaitinov, A S; Ganssauge, E R; Garpman, S; Gerassimov, S G; Gheata, A; Gheata, M; Grote, J; Gulamov, K G; Gupta, S K; Gupta, V K; Henjes, U; Jakobsson, B; Kanygina, E K; Karabova, M; Kharlamov, S P; Kovalenko, A D; Krasnov, S A; Kumar, V; Larionova, V G; Li, Y X; Liu, L S; Lokanathan, S; Lord, J J; Lukicheva, N S; Lu, Y; Luo, S B; Mangotra, L K; Manhas, I; Mittra, I S; Musaeva, A K; Nasyrov, S Z; Navotny, V S; Nystrand, J; Otterlund, I; Peresadko, N G; Qian, W Y; Qin, Y M; Raniwala, R; Rao, N K; Roeper, M; Rusakova, V V; Saidkhanov, N; Salmanova, N A; Seitimbetov, A M; Sethi, R; Singh, B; Skelding, D; Soderstrem, K; Stenlund, E; Svechnikova, L N; Svensson, T; Tawfik, A M; Tothova, M; Tretyakova, M I; Trofimova, T P; Tuleeva, U I; Vashisht, Vani; Vokal, S; Vrlakova, J; Wang, H Q; Wang, X R; Weng, Z Q; Wilkes, R J; Yang, C B; Yin, Z B; Yu, L Z; Zhang, D H; Zheng, P Y; Zhokhova, S I; Zhou, D C

    1999-03-01

    Angular distributions of charged particles produced in {sup 16}O and {sup 32}S collisions with nuclear track emulsion were studied at momenta 4.5 and 200 A GeV/c. Comparison with the angular distributions of charged particles produced in proton-nucleus collisions at the same momentum allows to draw the conclusion, that the angular distributions in nucleus-nucleus collisions can be seen as superposition of the angular distributions in nucleon-nucleus collisions taken at the same impact parameter b{sub NA}, that is mean impact parameter between the participating projectile nucleons and the center of the target nucleus.

  9. Nucleus-nucleus collision as superposition of nucleon-nucleus collisions

    International Nuclear Information System (INIS)

    Orlova, G.I.; Adamovich, M.I.; Aggarwal, M.M.

    1999-01-01

    Angular distributions of charged particles produced in 16 O and 32 S collisions with nuclear track emulsion were studied at momenta 4.5 and 200 A GeV/c. Comparison with the angular distributions of charged particles produced in proton-nucleus collisions at the same momentum allows to draw the conclusion, that the angular distributions in nucleus-nucleus collisions can be seen as superposition of the angular distributions in nucleon-nucleus collisions taken at the same impact parameter b NA , that is mean impact parameter between the participating projectile nucleons and the center of the target nucleus. (orig.)

  10. Aspects of Coulomb dissociation and interference in peripheral nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Nystrand, Joakim; Baltz, Anthony; Klein, Spencer R.

    2001-01-01

    Coherent vector meson production in peripheral nucleus-nucleus collisions is discussed. These interactions may occur for impact parameters much larger than the sum of the nuclear radii. Since the vector meson production is always localized to one of the nuclei, the system acts as a two-source interferometer in the transverse plane. By tagging the outgoing nuclei for Coulomb dissociation it is possible to obtain a measure of the impact parameter and thus the source separation in the interferometer. This is of particular interest since the life-time of the vector mesons are generally much shorter than the impact parameters of the collisions

  11. 33th all-union conference on nuclear spectroscopy and atomic nucleus structure

    International Nuclear Information System (INIS)

    Adam, J.; Bem, P.

    1984-01-01

    The 33rd All-Union Conference on Nuclear Spectroscopy and the Atomic Nucleus Structure was held in Moscow from April 19 to 22. The plenary session heard 5 papers which summed up the results of extensive programmes of theoretical and experimental research. More than two thirds of the conference were held in parallel sessions: Properties of Concrete Nuclei, Nuclear Reactions (theory, experiment), Theory of the Nucleus, Mechanisms of Alpha-, Beta- and Gamma Processes, Nuclear Spectroscopy Techniques and Applied Nuclear Spectroscopy. (B.S.)

  12. What can an antiproton and a nucleus learn from each other

    International Nuclear Information System (INIS)

    Garreta, D.

    1984-01-01

    This chapter attempts to show that the - p-nucleus interaction may provide very useful information, both about the elementary - NN interaction and about nuclear structure. Topics covered include simple features which make a low-energy antiproton an interesting probe of the nucleus; simple features which make a nucleus an interesting target for an antiproton; antiproton-nucleus elastic scattering; antiproton-nucleus inelastic scattering; proton knock-out reactions on nuclei; and annihilation of the antiprotons in nuclei. The aim of experiment PS184 at the Low-Energy Antiproton Ring (LEAR) is to provide accurate data with regard to the - p-nucleus interaction in the following areas: the angular distribution of antiprotons elastically scattered from 12 C, 40 Ca, and 208 Pb; the excitation energy spectra and some angular distributions of antiprotons inelastically scattered from 12 C, 40 Ca, and 208 Pb; and the excitation energy spectra for proton knock-out reaction on 6 Li, 45 Sc, 123 Sb, and 209 B; at forward angles

  13. HIJET: a Monte Carlo event generator for P-nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Ludlam, T.; Pfoh, A.; Shor, A.

    1985-01-01

    Comparisons are shown for the HIJET generated data and measured data for average multiplicities, rapidity distributions, and leading proton spectra in proton-nucleus and heavy ion reactions. The algorithm for the generator is one of an incident particle on a target of uniformly distributed nucleons. The dynamics of the interaction limit secondary interactions in that only the leading baryon may re-interact with the nuclear volume. Energy and four momentum are globally conserved in each event. 6 refs., 6 figs

  14. Cytochrome c interaction with hematite ({alpha}-Fe{sub 2}O{sub 3}) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Eggleston, Carrick M. [Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071 (United States)]. E-mail: carrick@uwyo.edu; Khare, Nidhi [Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071 (United States); Lovelace, David M. [Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071 (United States)

    2006-02-15

    The interaction of metalloproteins such as cytochromes with oxides is of interest for a number of reasons, including molecular catalysis of environmentally important mineral-solution electron transfer reactions (e.g., dehalogenations) and photovoltaic applications. Iron reduction by bacteria, thought to be cytochrome mediated, is of interest for geochemical and environmental remediation reasons. As a baseline for understanding cytochrome interaction with ferric oxide surfaces, we report on the interaction of mitochondrial cytochrome c (Mcc), a well-studied protein, with hematite ({alpha}-Fe{sub 2}O{sub 3}) surfaces. Mcc sorbs strongly to hematite from aqueous solution in a narrow pH range corresponding to opposite charge on Mcc and hematite (between pH 8.5 and 10, Mcc is positively charged and hematite surfaces are negatively charged). Cyclic voltammetry of Mcc using hematite electrodes gives redox potentials characteristic of Mcc in a native conformational state, with no evidence for unfolding on the hematite surface. Atomic force microscopy imaging is consistent with a loosely attached adsorbate that is easily deformed by the AFM tip. In phosphate-containing solution, Mcc adhers to the surface more strongly. These results establish hematite as a viable material for electrochemical and spectroscopic characterization of cytochrome-mineral interaction.

  15. Interaction of ionising radiations with matter

    International Nuclear Information System (INIS)

    Caudrelier, Olivier

    2010-01-01

    In a first part, this academic course addresses the interaction of non-charged particles with matter. The author more particularly addresses the interaction of a photon plasma with matter (attenuation of electromagnetic radiations, law of exponential attenuation, attenuation half value layer), the elementary phenomena of the interaction of a photon with matter (photoelectric effect, Compton effect, Thomson-Rayleigh scattering, materialisation, photo-nuclear reaction, prevalence domains, application in medical imagery), and the interaction of fast and slow neutrons with matter (elastic and inelastic scattering, radiative and non-radiative capture). The second part addresses the interaction of charged particles with matter. The author more particularly addresses the interaction with electrons present in the medium (ionization, excitation, stop efficiency, linear energy transfer, ionization linear density), the interaction with the nucleus (Bremsstrahlung), and the case of light particles (electrons) and of heavy particles (protons, alpha, fission products)

  16. Asymptotic value of screening parameter as determined from the one-electron fragment of the kinetic energy or electrostatic potential at the nucleus

    International Nuclear Information System (INIS)

    Teruya, Hirohide; Anno, Tosinobu

    1985-01-01

    Numerical value of lim sub(Z → infinity) delta(i, j)/delta Zsub(i), where (i, j) stands for average interaction energy of a pair of electrons embedded in hydrogenic orbitals (HAO's) is presented for a wide range of HAO's. Data to be presented should be useful to calculate the asymptotic limit of screening effect seen by an electron embedded in a given kind of orbital for an isoelectronic series of atoms as determined from the ''one-electron component'' of the total kinetic energy of or of the electrostatic potential at the nucleus within an atom. (author)

  17. Binding Interactions Between alpha-glucans from Lactobacillus reuteri and Milk Proteins Characterised by Surface Plasmon Resonance

    NARCIS (Netherlands)

    Diemer, Silja K.; Svensson, Birte; Babol, Linnea N.; Cockburn, Darrell; Grijpstra, Pieter; Dijkhuizen, Lubbert; Folkenberg, Ditte M.; Garrigues, Christel; Ipsen, Richard H.

    Interactions between milk proteins and alpha-glucans at pH 4.0-5.5 were investigated by use of surface plasmon resonance. The alpha-glucans were synthesised with glucansucrase enzymes from Lactobacillus reuteri strains ATCC-55730, 180, ML1 and 121. Variations in the molecular characteristics of the

  18. Correlations in hadron-nucleus collisions

    International Nuclear Information System (INIS)

    Wosiek, B.

    1976-09-01

    The correlations between the particles produced in interactions of hadrons with emulsion nuclei were investigated. The data are in qualitative agreement with the models which describe the interactions with nuclei as subsequent collisions of the fast part of excited hadronic matter inside the nucleus. (author)

  19. J/$\\psi$ production in proton-nucleus and nucleus-nucleus interactions at the CERN SPS

    CERN Document Server

    Abreu, M C; Alexa, C; Arnaldi, R; Ataian, M R; Baglin, C; Baldit, A; Bedjidian, Marc; Beolè, S; Boldea, V; Bordalo, P; Borges, G; Bussière, A; Capelli, L; Castanier, C; Castor, J I; Chaurand, B; Chevrot, I; Cheynis, B; Chiavassa, E; Cicalò, C; Claudino, T; Comets, M P; Constans, N; Constantinescu, S; Cortese, P; De Falco, A; De Marco, N; Dellacasa, G; Devaux, A; Dita, S; Drapier, O; Ducroux, L; Espagnon, B; Fargeix, J; Force, P; Gallio, M; Gavrilov, Yu K; Gerschel, C; Giubellino, P; Golubeva, M B; Gonin, M; Grigorian, A A; Grossiord, J Y; Guber, F F; Guichard, A; Gulkanian, H R; Hakobyan, R S; Haroutunian, R; Idzik, M; Jouan, D; Karavitcheva, T L; Kluberg, L; Kurepin, A B; Le Bornec, Y; Lourenço, C; Macciotta, P; MacCormick, M; Marzari-Chiesa, A; Masera, M; Masoni, A; Monteno, M; Musso, A; Petiau, P; Piccotti, A; Pizzi, J R; Prado da Silva, W L; Prino, F; Puddu, G; Quintans, C; Ramello, L; Ramos, S; Rato-Mendes, P; Riccati, L; Romana, A; Santos, H; Saturnini, P; Scalas, E; Scomparin, E; Serci, S; Shahoyan, R; Sigaudo, F; Silva, S; Sitta, M; Sonderegger, P; Tarrago, X; Topilskaya, N S; Usai, G L; Vercellin, Ermanno; Villatte, L; Willis, N

    2002-01-01

    The NA38 and NA50 experiments at the CERN SPS have measured charmonium production in different colliding systems with the aim of observing a phase transition from ordinary hadronic matter towards a state in which quarks and gluons are deconfined (quark-gluon plasma, QGP). This experimental research is based on the prediction that the J/ psi yield should be suppressed in deconfined matter. The analysis of the data collected by the NA50 experiment with Pb-Pb collisions at 158 GeV/c per nucleon shows that the J/ psi is anomalously suppressed with respect to the pattern observed in proton-nucleus and light ion reactions. (9 refs).

  20. Measure of back angle cross sections of antiproton-nucleus elastic scattering at 48 and 180 MeV

    International Nuclear Information System (INIS)

    Berrada, M.

    1986-04-01

    Antiproton-nucleus elastic scattering was studied in the LEAR ring at CERN. The scattering cross section at back angles (θ LAB = 142 to 164 deg inclusive) was measured using plastic scintillation detectors. Analysis of experimental data at 47 MeV for a CH target and at 182 MeV for CH, C12, 016, and 018 targets produces differential cross sections for back angles less than or equal to a few dozen microbarns. These results agree with theoretical microscopic predictions. The analysis improves understanding of antiproton-nucleus interaction and introduces a constraint on the construction of optical potentials. The antiproton-nucleus potential is shown to be highly absorbing, thereby excluding S type potentials, and removing the ambiguity arising from the analysis of antiprotonic atoms. The results also show that there is no attractive pocket in the real potential likely to lead to an increase of the back angle cross sections [fr

  1. MCH and apomorphine in combination enhance action potential firing of nucleus accumbens shell neurons in vitro

    Directory of Open Access Journals (Sweden)

    F Woodward Hopf

    2013-04-01

    Full Text Available The MCH and dopamine receptor systems have been shown to modulate a number of behaviors related to reward processing, addiction, and neuropsychiatric conditions such as schizophrenia and depression. In addition, MCH and dopamine receptors can interact in a positive manner, for example in the expression of cocaine self-administration. A recent report (Chung et al., 2011a showed that the DA1/DA2 dopamine receptor activator apomorphine suppresses pre-pulse inhibition, a preclinical model for some aspects of schizophrenia. Importantly, MCH can enhance the effects of lower doses of apomorphine, suggesting that co-modulation of dopamine and MCH receptors might alleviate some symptoms of schizophrenia with a lower dose of dopamine receptor modulator and thus fewer potential side effects. Here, we investigated whether MCH and apomorphine could enhance action potential firing in vitro in the nucleus accumbens shell (NAshell, a region which has previously been shown to mediate some behavioral effects of MCH. Using whole-cell patch-clamp electrophysiology, we found that MCH, which has no effect on firing on its own, was able to increase NAshell firing when combined with a subthreshold dose of apomorphine. Further, this MCH/apomorphine increase in firing was prevented by an antagonist of either a DA1 or a DA2 receptor, suggesting that apomorphine acts through both receptor types to enhance NAshell firing. The MCH/apomorphine-mediated firing increase was also prevented by an MCH receptor antagonist or a PKA inhibitor. Taken together, our results suggest that MCH can interact with lower doses of apomorphine to enhance NAshell firing, and thus that MCH and apomorphine might interact in vivo within the NAshell to suppress pre-pulse inhibition.

  2. Calculations on precompound reactions with alpha particles, A(α,α')X, at incident energies around 500 MeV

    International Nuclear Information System (INIS)

    Rittershausen, W.

    1987-01-01

    The model of Chiang et al. (1980) for nucleon induced precompound reactions, a generalization of the Glauber theory to lower energetical processes, was extended to heavier projectiles the elementary differential cross section of which may furthermore (at fixed incident energy) depend on the momentum transfer. The so modified model was applied to reactions of the type A(α,α')X at an incident energy of about 100 MeV/nucleon, excitation energies of the nucleus in the range 6 to 60 MeV, and for scattering angles from 3 to 6 0 . Thereby the Glauber coefficients were determined by means of the optical potentials known for the treated experiments. Local nucleon momentum distributions in the target nucleus were taken from calculations of Durand et al. (1982). The momentum distributions of the alpha particles after the first α-N collision were both for normalously and for homogeneously distributed nucleon momenta calculated analytically. The distributions after the second collision were determined by folding. For the control of these results and for the eventual calculation of the distributions after more than two collisions a Monte Carlo routine was written. The additional deviation of the alpha particles in real-valued potentials of the target nucleus were regarded. The results in which no free parameter occurs agree quite well in the shape with measured data. In one case it is also valid for the absolute quantities. (orig.) [de

  3. Single particle level scheme for alpha decay

    International Nuclear Information System (INIS)

    Mirea, M.

    1998-01-01

    The fine structure phenomenon in alpha decay was evidenced by Rosenblum. In this process the kinetic energy of the emitted particle has several determined values related to the structure of the parent and the daughter nucleus. The probability to find the daughter in a low lying state was considered strongly dependent on the spectroscopic factor defined as the square of overlap between the wave function of the parent in the ground state and the wave functions of the specific excited states of the daughter. This treatment provides a qualitative agreement with the experimental results if the variations of the penetrability between different excited states are neglected. Based on single particle structure during fission, a new formalism explained quantitatively the fine structure of the cluster decay. It was suggested that this formalism can be applied also to alpha decay. For this purpose, the first step is to construct the level scheme of this type of decay. Such a scheme, obtained with the super-asymmetric two-center potential, is plotted for the alpha decay of 223 Ra. It is interesting to note that, diabatically, the level with spin 3/2 emerging from 1i 11/2 (ground state of the parent) reaches an excited state of the daughter in agreement with the experiment. (author)

  4. K+ nucleus total cross sections

    International Nuclear Information System (INIS)

    Sawafta, R.

    1990-01-01

    The scattering of K + mesons from nuclei has attracted considerable interest in the last few years. The K + holds a very special position as the weakest of all strongly interaction probes. The average cross section is not larger than about 10 mb at lab momenta below 800 MeV/c, corresponding to a mean free path in the nucleus larger than 5 fm. Thus the K + is capable of probing the entire volume of the nucleus. Single scattering of the K + with a nucleon in the nucleus dominates the nuclear scattering, and only small and calculable higher order corrections are needed. The nucleon is a dynamical entity and its internal structure can, in principle, be altered by its surrounding nuclear environment. This work reports an experiment in which the K + is used to compare the nucleon in the nucleus with a free nucleon

  5. No need to be HAMLET or BAMLET to interact with histones: binding of monomeric alpha-lactalbumin to histones and basic poly-amino acids.

    Science.gov (United States)

    Permyakov, Serge E; Pershikova, Irina V; Khokhlova, Tatyana I; Uversky, Vladimir N; Permyakov, Eugene A

    2004-05-18

    The ability of a specific complex of human alpha-lactalbumin with oleic acid (HAMLET) to induce cell death with selectivity for tumor and undifferentiated cells was shown recently to be mediated by interaction of HAMLET with histone proteins irreversibly disrupting chromatin structure [Duringer, C., et al. (2003) J. Biol. Chem. 278, 42131-42135]. Here we show that monomeric alpha-lactalbumin (alpha-LA) in the absence of fatty acids is also able to bind efficiently to the primary target of HAMLET, histone HIII, regardless of Ca(2+) content. Thus, the modification of alpha-LA by oleic acid is not required for binding to histones. We suggest that interaction of negatively charged alpha-LA with the basic histone stabilizes apo-alpha-LA and destabilizes the Ca(2+)-bound protein due to compensation for excess negative charge of alpha-LA's Ca(2+)-binding loop by positively charged residues of the histone. Spectrofluorimetric curves of titration of alpha-LA by histone H3 were well approximated by a scheme of cooperative binding of four alpha-LA molecules per molecule of histone, with an equilibrium dissociation constant of 1.0 microM. Such a stoichiometry of binding implies that the binding process is not site-specific with respect to histone and likely is driven by just electrostatic interactions. Co-incubation of positively charged poly-amino acids (poly-Lys and poly-Arg) with alpha-LA resulted in effects which were similar to those caused by histone HIII, confirming the electrostatic nature of the alpha-LA-histone interaction. In all cases that were studied, the binding was accompanied by aggregation. The data indicate that alpha-lactalbumin can be used as a basis for the design of antitumor agents, acting through disorganization of chromatin structure due to interaction between alpha-LA and histone proteins.

  6. Long-range alpha detector

    International Nuclear Information System (INIS)

    MacArthur, D.W.; McAtee, J.L.

    1991-01-01

    Historically, alpha-particle and alpha-contamination detectors have been limited by the very short range of alpha particles in air and by relatively poor sensitivity even if the particles are intercepted. Alpha detectors have had to be operated in a vacuum or in close proximity to the source if reasonable efficiency is desired. Alpha particles interact with the ambient air, producing ionization in the air at the rate of ∼30,000 ion pairs per mega-electron-volt of alpha energy. These charges can be transported over significant distances (several meters) in a moving current of air generated by a small fan. An ion chamber located in front of the fan measures the current carried by the moving ions. The long-range alpha detector (LRAD) offers several advantages over more traditional alpha detectors. First and foremost, it can operate efficiently even if the contamination is not easily accessible. Second, ions generated by contamination in crevices and other unmonitorable locations can be detected if the airflow penetrates those areas. Third, all of the contamination on a large surface will generate ions that can be detected in a single detector; hence, the detector's sensitivity to distributed sources is not limited by the size of the probe. Finally, a simple ion chamber can detect very small electric currents, making this technique potentially quite sensitive

  7. Estrogen alters the diurnal rhythm of alpha 1-adrenergic receptor densities in selected brain regions

    International Nuclear Information System (INIS)

    Weiland, N.G.; Wise, P.M.

    1987-01-01

    Norepinephrine regulates the proestrous and estradiol-induced LH surge by binding to alpha 1-adrenergic receptors. The density of alpha 1-receptors may be regulated by estradiol, photoperiod, and noradrenergic neuronal activity. We wished to determine whether alpha 1-receptors exhibit a diurnal rhythm in ovariectomized and/or estradiol-treated female rats, whether estradiol regulates alpha 1-receptors in those areas of brain involved with LH secretion and/or sexual behavior, and whether the concentrations of alpha-receptors vary inversely relative to previously reported norepinephrine turnover patterns. Young female rats, maintained on a 14:10 light-dark cycle were ovariectomized. One week later, half of them were outfitted sc with Silastic capsules containing estradiol. Groups of animals were decapitated 2 days later at 0300, 1000, 1300, 1500, 1800, and 2300 h. Brains were removed, frozen, and sectioned at 20 micron. Sections were incubated with [ 3 H]prazosin in Tris-HCl buffer, washed, dried, and exposed to LKB Ultrofilm. The densities of alpha 1-receptors were quantitated using a computerized image analysis system. In ovariectomized rats, the density of alpha 1-receptors exhibited a diurnal rhythm in the suprachiasmatic nucleus (SCN), medial preoptic nucleus (MPN), and pineal gland. In SCN and MPN, receptor concentrations were lowest during the middle of the day and rose to peak levels at 1800 h. In the pineal gland, the density of alpha 1-receptors was lowest at middark phase, rose to peak levels before lights on, and remained elevated during the day. Estradiol suppressed the density of alpha 1 binding sites in the SCN, MPN, median eminence, ventromedial nucleus, and the pineal gland but had no effect on the lateral septum. Estrogen treatment altered the rhythm of receptor densities in MPN, median eminence, and the pineal gland

  8. Estrogen alters the diurnal rhythm of alpha 1-adrenergic receptor densities in selected brain regions

    Energy Technology Data Exchange (ETDEWEB)

    Weiland, N.G.; Wise, P.M.

    1987-11-01

    Norepinephrine regulates the proestrous and estradiol-induced LH surge by binding to alpha 1-adrenergic receptors. The density of alpha 1-receptors may be regulated by estradiol, photoperiod, and noradrenergic neuronal activity. We wished to determine whether alpha 1-receptors exhibit a diurnal rhythm in ovariectomized and/or estradiol-treated female rats, whether estradiol regulates alpha 1-receptors in those areas of brain involved with LH secretion and/or sexual behavior, and whether the concentrations of alpha-receptors vary inversely relative to previously reported norepinephrine turnover patterns. Young female rats, maintained on a 14:10 light-dark cycle were ovariectomized. One week later, half of them were outfitted sc with Silastic capsules containing estradiol. Groups of animals were decapitated 2 days later at 0300, 1000, 1300, 1500, 1800, and 2300 h. Brains were removed, frozen, and sectioned at 20 micron. Sections were incubated with (/sup 3/H)prazosin in Tris-HCl buffer, washed, dried, and exposed to LKB Ultrofilm. The densities of alpha 1-receptors were quantitated using a computerized image analysis system. In ovariectomized rats, the density of alpha 1-receptors exhibited a diurnal rhythm in the suprachiasmatic nucleus (SCN), medial preoptic nucleus (MPN), and pineal gland. In SCN and MPN, receptor concentrations were lowest during the middle of the day and rose to peak levels at 1800 h. In the pineal gland, the density of alpha 1-receptors was lowest at middark phase, rose to peak levels before lights on, and remained elevated during the day. Estradiol suppressed the density of alpha 1 binding sites in the SCN, MPN, median eminence, ventromedial nucleus, and the pineal gland but had no effect on the lateral septum. Estrogen treatment altered the rhythm of receptor densities in MPN, median eminence, and the pineal gland.

  9. Determination of cross sections for 12C-nucleus interactions at 4.5 GeV/c per incident nucleon momentum

    International Nuclear Information System (INIS)

    Aksinenko, V.D.; Anikina, M.Kh.; Buttsev, V.S.

    1980-01-01

    Interactions of relativistic 12 C nuclei with C, Ne, Si, Cu, Zr pure nuclear targets haVe been studied in the SKM-200 streamer chamber. The cross sections have been determined for inelastic interactions and for the emission of at least one negative particle. An analysis of possible sources of systematic errors has been performed. A comparison is made with results of other experiments and data obtained eaplier by the SKM-200 Collaboration for 4 He-nucleus interactions

  10. Postsynaptic alpha-adrenergic receptors potentiate the beta-adrenergic stimulation of pineal serotonin N-acetyltransferase.

    OpenAIRE

    Klein, D C; Sugden, D; Weller, J L

    1983-01-01

    The role played by postsynaptic alpha-adrenergic receptors in the stimulation of pineal N-acetyltransferase (EC 2.3.1.5) and [3H]melatonin production was investigated in the rat. In vivo studies indicated that phenylephrine, an alpha-adrenergic agonist, potentiated and prolonged the effects of isoproterenol, a beta-adrenergic agonist. Similar observations were made in organ culture with glands devoid of functional nerve endings. In addition, a combination of 1 microM prazosin, an alpha 1-adre...

  11. Localisation of the subthalamic nucleus in Parkinson's disease with neural beta and gamma activity of local field potentials

    NARCIS (Netherlands)

    Verhagen, R.; Zwartjes - de Klerk, D.G.M; Heida, Tjitske; Contarino, M.F.; de Bie, R.M.A.; van den Munckhof, P; Schuurman, P.R.; Martens, H.C.F.; Veltink, Petrus H.; Bour, L.J.

    2013-01-01

    To evaluate the nature of oscillatory activity in the subthalamic nucleus (STN) by means of intraoperative local field potential (LFP) recordings, its relationship with microelectrode recordings (MER) and its potential use to locate the STN and its sensorimotor sub-area in patients with Parkinson’s

  12. Calculation of nuclear radius using alpha decay

    International Nuclear Information System (INIS)

    Castro, R.B. de.

    1988-01-01

    Using a Quantum Theory approach for the Alpha-Decay process, a formula is deduced for determination of the nuclear radius of the s-state, that is, a nuclear model with a spherical shell. The hypothesis that it is possible to individualize the alpha particle and the daughter nucleus at the moment of the alpha particle emission is considered. In considered in these conditions, the treatment of a two body problem considered as point particles, repelling each other by Coulomb's Law. Using the new values of the fundamental physical constants, experimentally determinated, by substitution of their numerical values in the proposed, new values of nuclear radii are obtained. These values are compared with those found in the literature. (author) [pt

  13. Alpha-crystallins are involved in specific interactions with the murine gamma D/E/F-crystallin-encoding gene.

    Science.gov (United States)

    Pietrowski, D; Durante, M J; Liebstein, A; Schmitt-John, T; Werner, T; Graw, J

    1994-07-08

    The promoter of the murine gamma E-crystallin (gamma E-Cry) encoding gene (gamma E-cry) was analyzed for specific interactions with lenticular proteins in a gel-retardation assay. A 21-bp fragment immediately downstream of the transcription initiation site (DOTIS) is demonstrated to be responsible for specific interactions with lens extracts. The DOTIS-binding protein(s) accept only the sense DNA strand as target; anti-sense or double-stranded DNA do not interact with these proteins. The DOTIS sequence element is highly conserved among the murine gamma D-, gamma E- and gamma F-cry and is present at comparable positions in the orthologous rat genes. Only a weak or even no protein-binding activity is observed if a few particular bases are changed, as in the rat gamma A-, gamma C- and gamma E-cry elements. DOTIS-binding proteins were found in commercially available bovine alpha-Cry preparations. The essential participation of alpha-Cry in the DNA-binding protein complex was confirmed using alpha-Cry-specific monoclonal antibody. The results reported here point to a novel function of alpha-Cry besides the structural properties in the lens.

  14. Electromagnetic processes in nucleus-nucleus collisions relating to space radiation research

    Science.gov (United States)

    Norbury, John W.

    1992-01-01

    Most of the papers within this report deal with electromagnetic processes in nucleus-nucleus collisions which are of concern in the space radiation program. In particular, the removal of one and two nucleons via both electromagnetic and strong interaction processes has been extensively investigated. The theory of relativistic Coulomb fission has also been developed. Several papers on quark models also appear. Finally, note that the theoretical methods developed in this work have been directly applied to the task of radiation protection of astronauts. This has been done by parameterizing the theoretical formalism in such a fashion that it can be used in cosmic ray transport codes.

  15. A Primary Role for Nucleus Accumbens and Related Limbic Network in Vocal Tics.

    Science.gov (United States)

    McCairn, Kevin W; Nagai, Yuji; Hori, Yukiko; Ninomiya, Taihei; Kikuchi, Erika; Lee, Ju-Young; Suhara, Tetsuya; Iriki, Atsushi; Minamimoto, Takafumi; Takada, Masahiko; Isoda, Masaki; Matsumoto, Masayuki

    2016-01-20

    Inappropriate vocal expressions, e.g., vocal tics in Tourette syndrome, severely impact quality of life. Neural mechanisms underlying vocal tics remain unexplored because no established animal model representing the condition exists. We report that unilateral disinhibition of the nucleus accumbens (NAc) generates vocal tics in monkeys. Whole-brain PET imaging identified prominent, bilateral limbic cortico-subcortical activation. Local field potentials (LFPs) developed abnormal spikes in the NAc and the anterior cingulate cortex (ACC). Vocalization could occur without obvious LFP spikes, however, when phase-phase coupling of alpha oscillations were accentuated between the NAc, ACC, and the primary motor cortex. These findings contrasted with myoclonic motor tics induced by disinhibition of the dorsolateral putamen, where PET activity was confined to the ipsilateral sensorimotor system and LFP spikes always preceded motor tics. We propose that vocal tics emerge as a consequence of dysrhythmic alpha coupling between critical nodes in the limbic and motor networks. VIDEO ABSTRACT. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Contemporary models of the atomic nucleus

    CERN Document Server

    Nemirovskii, P E

    2013-01-01

    Contemporary Models of the Atomic Nucleus discusses nuclear structure and properties, expounding contemporary theoretical concepts of the low-energy nuclear processes underlying in nuclear models. This book focuses on subjects such as the optical nuclear model, unified or collective model, and deuteron stripping reaction. Other topics discussed include the basic nuclear properties; shell model; theoretical analysis of the shell model; and radiative transitions and alpha-decay. The deuteron theory and the liquid drop nuclear model with its application to fission theory are also mentioned, but o

  17. Coulomb potentials between spherical heavy ions

    International Nuclear Information System (INIS)

    Iwe, H.

    1982-01-01

    The Coulomb interaction between spherical nuclei having arbitrary radial nuclear charge distributions is calculated. All these realistic Coulomb potentials are given in terms of analytical expressions and are available for immediate application. So in no case a numerical computation of the Coulomb integral is required. The parameters of the charge distributions are taken from electron scattering analysis. The Coulomb self-energies of the charge distributions used are also calculated analytically in a closed form. For a number of nucleus-nucleus pairs, the Coulomb potentials derived from realistic charge distributions are compared with those normally used in various nucleus-nucleus optical model calculations. In this connection a detailed discussion of the problem how to choose consistently Coulomb parameters for different approximations is given. (orig.)

  18. Lectin interactions with alpha-galactosylated xenoantigens

    DEFF Research Database (Denmark)

    Kirkeby, Svend; Moe, Dennis

    2002-01-01

    alpha-Galactosylated xenoantigens (Galalpha1-3Galbeta1-4GlcNAcbeta1 and Galalpha1-3Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc) are often detected with the alpha-Gal specific lectin Griffonia simplicifolia 1 isolectin B4 (GS1 B4). However, this lectin exhibits a broad and variable specificity for carboh...

  19. Sea level muon spectrum and muon charge ratio derived from CERN results for nucleon-nucleus inelastic interactions

    CERN Document Server

    Bhattacharya, D P

    1979-01-01

    The sea level cosmic ray spectrum and muon charge ratio have been estimated by using the energy moments of the cross section for proton- air inelastic collisions. These energy moments have been determined by interpolation from CERN results for proton-nucleus inelastic interactions in pion production. The derived results are compared with previous work. (26 refs).

  20. Distinct neural pathways mediate alpha7 nicotinic acetylcholine receptor-dependent activation of the forebrain

    DEFF Research Database (Denmark)

    Thomsen, Morten S; Hay-Schmidt, Anders; Hansen, Henrik H

    2010-01-01

    alpha(7) nicotinic acetylcholine receptor (nAChR) agonists are candidates for the treatment of cognitive deficits in schizophrenia. Selective alpha(7) nAChR agonists, such as SSR180711, activate neurons in the medial prefrontal cortex (mPFC) and nucleus accumbens shell (ACCshell) in rats, regions...

  1. On the formfactor of the imaginary part and its coupling to the real optical potential for the α-nucleus scattering

    International Nuclear Information System (INIS)

    Freindl, L.; Dabrowski, H.; Grotowski, K.; Planeta, R.; Uniwersytet Jagiellonski, Krakow

    1980-01-01

    The model-independent formfactor of the absorptive α-nucleus potential was calculated and compared with model dependent ones. The coupling between the shapes of the real and imaginary potential is discussed. (author)

  2. Evaluation of the Interaction between NMDA Receptors of Nucleus Accumbens and Muscarinic Receptors in Memory

    Directory of Open Access Journals (Sweden)

    Saba Taheri

    2013-02-01

    Full Text Available Background and Objectives: Whereas studies have indicated the interaction between NMDA and cholinergic systems, this study was performed with the aim of determining the role of NMDA receptors in the nucleus accumbens (NAc in scopolamine-induced amnesia.Methods: In this study, at first rats were anesthetized with intra-peritoneal injection of ketamine hydrochloride plus xylazine, and then placed in a stereotaxic apparatus. Two stainless-steel cannulas were placed 2mm above nucleus accumbens shell. All animals were allowed to recover for one week, before beginning the behavioral testing. Then, animals were trained in a step-through type inhibitory avoidance task. The drugs were injected after successful training and before testing. The animals were tested 24h after training, and the step-through latency time was measured as the memory criterion in male Wistar rats. One-way analysis of variance and Tukey’s test were used for analysis of the data. p<0.05 was considered statistically significant.Results: Intra-nucleus accumbens (intra-NAc injection of scopolamine or NMDA caused impairment in memory in rats. Although, co-administration of an ineffective dose of NMDA with an ineffective dose of scopolamine had no significant effect on memory performance, effective doses of NMDA prevented the amnesic effect of scopolamine on inhibitory avoidance memory. On the other hand, intra-NAc injection of NMDA receptor antagonist, i.e., MK-801 caused no change in memory performance by itself, and its co-administration with an effective dose of scopolamine could not prevent the impairing effect of the latter drug. Conclusion: The finding of this study indicated that NMDA receptors in the nucleus accumbens are involved in the modulation of scopolamine-induced amnesia.

  3. Study of nucleus-nucleus interaction from elastic and inelastic scattering of 12C ions at intermediate energies

    International Nuclear Information System (INIS)

    Hostachy, J.Y.

    1987-01-01

    The elastic and inelastic scattering angular distributions of 12 C on the targets 12 C and 208 Pb have been measured at the Laboratoire National Saturne (Saclay) using the spectrometer SPES 1. The data have been analysed in the framework of the optical model with Woods-Saxon potentials. A near side/far side decomposition of the cross-section has provided a more detailed insight into the refraction effects. These analysises show that the strong absorption radius, the reaction cross-section, and consequently the absorption in the surface region, decrease when the incident energy increases, allowing to probe the inner part of the ion-ion potential. The transparency region extends down to a radial internuclei distance of about 3 fm for the 12 C - 12 C system and 8 fm for the 12 C - 208 Pb system. The onset of a decrease of the imaginary potential has been deduced for the two systems. The real potential is also decreasing, but much more rapidly for the 12 C - 208 Pb system than for 12 C- 12 C. We have also developed a microscopic approach in the optical limit of the Glauber theory, including the Pauli-blocking, the Fermi motion and the nucleus finite size effects. For the intermediate energies, the calculations are in fair agreement with the experimental data [fr

  4. Dissipation in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Santanu Pal

    1984-01-01

    This paper deals with the mechanism of one- and two-body dissipations in nucleus-nucleus collisions. The average energy transferred to nuclear excitations is calculated using a time-dependent density matrix approach with lowest-order approximations. Considering the nuclei as Fermi gases, and using a gaussian-type NN interaction as the basic perturbation, simplified expressions are obtained for energy dissipations. These expressions are quite instructive to follow a number of interesting aspects of one- and two-body dissipations. It is theoretically observed that the memory time for the two-body dissipation is significantly smaller than that of one-body dissipation. A threshold-type dependence of the transferred energy on the relative velocity between the two nuclei is also observed. This threshold velocity is found to be related with the intrinsic nucleon kinetic energy for two-body dissipation and with the nuclear size for the one-body case. This observation further suggests that the total dissipated energy is shared between the two nuclei approximately in the ratio of their masses. The physical origin of these observations is also explained. Numerical calculations further illustrate some characteristic features of one- and two-body dissipations. (orig.)

  5. On the formfactor of the imaginary parts and its coupling to the real optical potential for the α-nucleus scattering

    International Nuclear Information System (INIS)

    Freindl, L.; Dabrowski, H.; Grotowski, K.; Planeta, R.; Uniwersytet Jagiellonski, Krakow

    1979-01-01

    The model independent formfactor of the absorptive α-nucleus potential is calculated and compared with model dependent ones. The coupling between the shapes of the real and the imaginary potential is discussed. (Author)

  6. Nucleon-nucleus inelastic scattering using a relativistic impulse approximation with exchange

    International Nuclear Information System (INIS)

    Rost, E.; Shepard, J.R.

    1987-01-01

    We formulate a microscopic relativistic treatment of nucleon-nucleus inelastic scattering in a distorted wave impulse approximation. The interaction is taken from a Lorentz invariant formulation with explicit direct and exchange terms constrained by fitting to experimental NN amplitudes. This procedure allows us to apply the theory in the lower range of intermediate energies (100--400 MeV) where exchange effects are likely to be important. Application to inelastic scattering uses this interaction for both the distorting potentials and the transition interaction. Effects of explicit exchange are studied and a preliminary analysis of /sup 12/C(p,p') data is presented

  7. Potential antiradical and alpha-glucosidase inhibitors from Ecklonia maxima (Osbeck) Papenfuss.

    Science.gov (United States)

    Rengasamy, Kannan R R; Aderogba, Mutalib A; Amoo, Stephen O; Stirk, Wendy A; Van Staden, Johannes

    2013-11-15

    Alpha-glucosidase inhibitors play a potential role in the treatment of type 2 diabetes by delaying glucose absorption in the small intestine. Ecklonia maxima, a brown alga which grows abundantly on the west coast of South Africa, is used to produce alginate, animal feed, nutritional supplements and fertilizer. The crude aqueous methanol extract, four solvent fractions and three phlorotannins: 1,3,5-trihydroxybenezene (phloroglucinol) (1), dibenzo [1,4] dioxine-2,4,7,9-tetraol (2) and hexahydroxyphenoxydibenzo [1,4] dioxine (eckol) (3) isolated from E. maxima were evaluated for antiradical and alpha-glucosidase inhibitory activities. All the phlorotannins tested had strong antioxidant activities on DPPH free radicals with EC50 values ranging from 0.008 to 0.128μM. Compounds 2 and 3 demonstrated stronger antioxidant activity and an alpha-glucosidase inhibitory property than positive controls. These results suggest that E. maxima could be a natural source of potent antioxidants and alpha-glucosidase inhibitors. This study could facilitate effective utilization of E. maxima as an oral antidiabetic drug or functional food ingredient with a promising role in the formulation of medicines and nutrition supplements. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Transverse Energy in nucleus-nucleus collisions: A review

    International Nuclear Information System (INIS)

    Tincknell, M.

    1988-01-01

    The status of Transverse Energy (E/sub T/) in relativistic nucleus-nucleus collisions at the Brookhaven AGS and the CERN SPS is reviewed. The definition of E/sub T/ and its physical significance are discussed. The basic techniques and limitations of the experimental measurements are presented. The acceptances of the major experiments to be discussed are shown, along with remarks about their idiosyncrasies. The data demonstrate that the nuclear geometry of colliding spheres primarily determines the shapes of the observed spectra. Careful account of the acceptances is crucial to comparing and interpreting results. It is concluded that nuclear stopping power is high, and that the amount of energy deposited into the interaction volume is increasing with beam energy even at SPS energies. The energy densities believed to be obtained at the SPS are close to the critical values predicted for the onset of a quark-gluon plasma. 25 refs., 8 figs

  9. Identification of the gamma subunit-interacting residues on photoreceptor cGMP phosphodiesterase, PDE6alpha '.

    Science.gov (United States)

    Granovsky, A E; Artemyev, N O

    2000-12-29

    Photoreceptor cGMP phosphodiesterase (PDE6) is the effector enzyme in the G protein-mediated visual transduction cascade. In the dark, the activity of PDE6 is shut off by the inhibitory gamma subunit (Pgamma). Chimeric proteins between cone PDE6alpha' and cGMP-binding and cGMP-specific PDE (PDE5) have been constructed and expressed in Sf9 cells to study the mechanism of inhibition of PDE6 catalytic activity by Pgamma. Substitution of the segment PDE5-(773-820) by the corresponding PDE6alpha'-(737-784) sequence in the wild-type PDE5 or in a PDE5/PDE6alpha' chimera containing the catalytic domain of PDE5 results in chimeric enzymes capable of inhibitory interaction with Pgamma. The catalytic properties of the chimeric PDEs remained similar to those of PDE5. Ala-scanning mutational analysis of the Pgamma-binding region, PDE6alpha'-(750-760), revealed PDE6alpha' residues essential for the interaction. The M758A mutation markedly impaired and the Q752A mutation moderately impaired the inhibition of chimeric PDE by Pgamma. The analysis of the catalytic properties of mutant PDEs and a model of the PDE6 catalytic domain suggest that residues Met(758) and Gln(752) directly bind Pgamma. A model of the PDE6 catalytic site shows that PDE6alpha'-(750-760) forms a loop at the entrance to the cGMP-binding pocket. Binding of Pgamma to Met(758) would effectively block access of cGMP to the catalytic cavity, providing a structural basis for the mechanism of PDE6 inhibition.

  10. Reconstruction of spin-tensor of 4. 43 MeV state density matrix of the /sup 12/C nucleus in the /sup 12/C(. cap alpha. ,. cap alpha. sub(1). gamma. sub(4,43))/sup 12/C reaction at Esub(. cap alpha. )=25 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, G.S.; Lebedev, V.M.; Orlova, N.V.; Spasskij, A.V.; Teplov, I.B.; Shakhvorostova, G.V.; Belkina, M.R. (Moskovskij Gosudarstvennyj Univ. (USSR). Nauchno-Issledovatel' skij Inst. Yadernoj Fiziki)

    1984-01-01

    The results of measuring double differential cross sections of the reaction of inelastic scattering 24.8 MeV ..cap alpha..-particles sup(12)C(..cap alpha.., ..cap alpha..sub(1)..gamma..sub(4.43))sup(12)C in different planes of ..gamma..-quantum escape relatively to the plane of the reaction phisub(..gamma..)=30, 60 and 90 deg are presented. Non-monochromaticity of the beam made up 1%. Functions of angular correlation of the reaction are measured for four angles THETAsub(..cap alpha..)=21, 39, 59 and 135 deg corresponding to maxima of differential cross section in angular distribution of inelastically scattered ..cap alpha..-particles and for THETAsub(..cap alpha..)=89 deg corresponding to the minimum of angular distribution. The results of measurements permit to reconstruct all the components of irreducible spin-tensors of the matrix of state density 4.43 MeV (2/sup +/) formed in this reaction. The values of populations of substates by the projection of the spin of this state are obtained. The analysis of the obtained results testify to the fact that mechanism of inelastic scattering is not reduced to impulse approximation and mechanisms associated with delay in interaction do not make noticeable contribution for the given angles of ..cap alpha..-particle escape.

  11. Monte Carlo calculation of the maximum therapeutic gain of tumor antivascular alpha therapy

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chen-Yu; Oborn, Bradley M.; Guatelli, Susanna; Allen, Barry J. [Centre for Experimental Radiation Oncology, St. George Clinical School, University of New South Wales, Kogarah, New South Wales 2217 (Australia); Illawarra Cancer Care Centre, Wollongong, New South Wales 2522, Australia and Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522 (Australia); Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522 (Australia); Centre for Experimental Radiation Oncology, St. George Clinical School, University of New South Wales, Kogarah, New South Wales 2217 (Australia)

    2012-03-15

    Purpose: Metastatic melanoma lesions experienced marked regression after systemic targeted alpha therapy in a phase 1 clinical trial. This unexpected response was ascribed to tumor antivascular alpha therapy (TAVAT), in which effective tumor regression is achieved by killing endothelial cells (ECs) in tumor capillaries and, thus, depriving cancer cells of nutrition and oxygen. The purpose of this paper is to quantitatively analyze the therapeutic efficacy and safety of TAVAT by building up the testing Monte Carlo microdosimetric models. Methods: Geant4 was adapted to simulate the spatial nonuniform distribution of the alpha emitter {sup 213}Bi. The intraluminal model was designed to simulate the background dose to normal tissue capillary ECs from the nontargeted activity in the blood. The perivascular model calculates the EC dose from the activity bound to the perivascular cancer cells. The key parameters are the probability of an alpha particle traversing an EC nucleus, the energy deposition, the lineal energy transfer, and the specific energy. These results were then applied to interpret the clinical trial. Cell survival rate and therapeutic gain were determined. Results: The specific energy for an alpha particle hitting an EC nucleus in the intraluminal and perivascular models is 0.35 and 0.37 Gy, respectively. As the average probability of traversal in these models is 2.7% and 1.1%, the mean specific energy per decay drops to 1.0 cGy and 0.4 cGy, which demonstrates that the source distribution has a significant impact on the dose. Using the melanoma clinical trial activity of 25 mCi, the dose to tumor EC nucleus is found to be 3.2 Gy and to a normal capillary EC nucleus to be 1.8 cGy. These data give a maximum therapeutic gain of about 180 and validate the TAVAT concept. Conclusions: TAVAT can deliver a cytotoxic dose to tumor capillaries without being toxic to normal tissue capillaries.

  12. The suprachiasmatic nucleus-paraventricular nucleus interactions: a bridge to the neuroendocrine and autonomic nervous system

    NARCIS (Netherlands)

    Buijs, R. M.; Hermes, M. H.; Kalsbeek, A.

    1998-01-01

    Vasopressin (VP) is one of the principal neurotransmitters of the suprachiasmatic nucleus (SCN). By means of anatomical, physiological and electrophysiological techniques we have demonstrated that VP containing pathways from the SCN serve to affect neuroendocrine and 'autonomic' neurons in the

  13. TENORM wastes and the potential alpha radiation dose to aquatic biota

    International Nuclear Information System (INIS)

    Paschoa, A.S.

    2002-01-01

    In the years seventies release-rates and derived limits for releasing radionuclides into the environment were adopted for each particular radionuclide and for a number of pathways. The release-rate limit adopted for alpha emitters was 10 15 Bq.y -1 for a single site, but limited to 10 14 Bq.y -1 for 226 Ra and supported 210 Po. In addition, to meet the requirements of the London Convention, a derived limit should be expressed in terms of concentration, which for alpha emitters was 10 10 Bq.t -1 , but limited to 10 14 Bq.t -1 for 226 Ra and supported 210 Po, assuming an upper limit to the mass dumping rate of 10 5 t per year at a single dumping site. New data on the radioactivity in the marine environment and biota, including plankton, indicated a potential alpha radiation dose to these aquatic organisms due to the release of technologically enhanced naturally occurring radioactive materials (TENORM) wastes. At the highest accumulation of 239 Pu in the zooplankton Gammarus in Thule, Greenland, due to an accidental release associated with military activities, the dose rate reached about 0.14 μGy.h -1 . Such dose rate was similar to that received by the phytoplankton Chaetoceros and Rhizosolenia from Agulhas current, Africa, due to naturally occurring radioactive materials (NORM) supposedly enhanced for almost one century of gold mining at first, and subsequently because of heap-leaching uranium extraction from the tailings left behind by earlier gold miners. The paper will discuss the alpha radiation dose to aquatic biota, in general, and to plankton, in particular, due to potential releases of TENORM wastes in the aquatic environment. (author)

  14. In silico study of curcumol, curcumenol, isocurcumenol, and β-sitosterol as potential inhibitors of estrogen receptor alpha of breast cancer

    Directory of Open Access Journals (Sweden)

    Resmi Mustarichiei

    2014-03-01

    Full Text Available Background: Based on data from the Hospital Information System (HIS in 2007, breast cancer is the top ranked diagnosed cancer in Indonesia. Estrogen receptor alpha (ERα is associated with breast cancer because it is found in high levels in cancer tissues. Curcumol, curcumenol, isocurcumenol of white tumeric rhizomes (Curcuma zedoaria (Christm. Roscoe, and β-sitosterol from seeds of pumpkin (Cucurbita pepo L. have been reported to have inhibitory activity against cancer cells. This study presents the in silico study of these compounds as inhibitors of ERα.Methods: Docking simulations are carried out in this paper to visualize molecular-level interactions between the four compounds with ERα. Docking simulations between estradiol and tamoxifen on ERα are carried out as well.Results: Docking results indicated that curcumol, curcumenol, isocurcumenol, and β-sitosterol showed inhibitory activity againts estrogen receptor alpha (ERα.  The order of potency is shown consecutively by isocurcumenol, curcumol, curcumenol, and β-sitosterol with values 0.584 M, 1.36 M, 1.61 M, and 7.35 M respectively. Curcumenol and estradiol interacts with ERα through hydrogen bonds and hydrophobic interactions, whereas curcumol, isocurcumenol, β-sitosterol and tamoxifen through hydrophobic interactions in succession. Conclusion: Natural products containing all four compounds have the potential to be used as drugs or adjuvant drugs in breast cancer therapy.Keywords: β-sitosterol, breast cancer, curcumol, curcumenol, estradiol, ERα, isocurcumenol

  15. Model for fusion and cool compound nucleus formation based on the fragmentation theory

    International Nuclear Information System (INIS)

    Malhotra, N.; Aroumougame, R.; Saroha, D.R.; Gupta, R.K.

    1986-01-01

    Collective potential energy surfaces are calculated in both the adiabatic and sudden approximations by using the asymmetric two-center shell model in the Strutinsky method. It is shown that fusion of two colliding heavy ions occurs by their crossing over of the adiabatic interaction barrier. The adiabatic scattering potentials present two barriers, whereas no barrier is shown to occur in sudden scattering potentials. The first barrier is obtained just past the saddle shape but is too low, such that a deep inelastic process is expected. The other, inner, barrier is high enough to let the system fall into the fusion well, whose excitation energy then determines whether a cool compound nucleus is produced or the fusion-fission process occurs. For a given compound nucleus, the excitation energy is found to be small for only a few target-projectile combinations, which increase as their mass asymmetry increases. Such target-projectile combinations which refer to a cool compound nucleus can be identified by a simple calculation of the fragmentation potential based on the ground state binding energies with Coulomb and proximity effects calculated at a constant relative separation of the two nuclei. Our calculations are made for the composite systems with 102 < or =Z < or =114

  16. Model for fusion and cool compound nucleus formation based on the fragmentation theory

    International Nuclear Information System (INIS)

    Malhotra, N.; Aroumougame, R.; Saroha, D.R.; Gupta, R.K.

    1985-07-01

    The collective potential energy surfaces are calculated in both the adiabatic and sudden approximations by using the asymmetric two centre shell model in Strutinsky method. It is shown that fusion of two colliding heavy ions occur by their crossing over of the adiabatic interaction barrier. The adiabatic scattering potentials present two barriers whereas no barrier is shown to occur in sudden scattering potentials. The first barrier is obtained just past the saddle shape but is too low, such that a deep inelastic process is expected. The other, inner, barrier is high enough to let the system fall into the fusion well, whose excitation energy then determine whether a cool compound nucleus is produced or the fusion-fission process occurs. For a given compound nucleus, the excitation energy is found to be small for only a few target-projectile combinations, which increase as their mass asymmetry increases. Such target-projectile combinations which refer to a cool compound nucleus, can be identified by a simple calculation of the fragmentation potential based on the ground state binding energies with Couloumb and proximity effects calculated at a constant relative separation of the two nuclei. Our calculations are made for the composite systems with 102<=Z<=114. (author)

  17. Studies of alpha-helicity and intersegmental interactions in voltage-gated Na+ channels: S2D4.

    Directory of Open Access Journals (Sweden)

    Zhongming Ma

    2009-11-01

    Full Text Available Much data, including crystallographic, support structural models of sodium and potassium channels consisting of S1-S4 transmembrane segments (the "voltage-sensing domain" clustered around a central pore-forming region (S5-S6 segments and the intervening loop. Voltage gated sodium channels have four non-identical domains which differentiates them from the homotetrameric potassium channels that form the basis for current structural models. Since potassium and sodium channels also exhibit many different functional characteristics and the fourth domain (D4 of sodium channels differs in function from other domains (D1-D3, we have explored its structure in order to determine whether segments in D4 of sodium channels differ significantly from that determined for potassium channels. We have probed the secondary and tertiary structure and the role of the individual amino acid residues of the S2D4 of Na(v1.4 by employing cysteine-scanning mutagenesis (with tryptophan and glutamine substituted for native cysteine. A Fourier transform power spectrum of perturbations in free energy of steady-state inactivation gating (using midpoint potentials and slopes of Boltzmann equation fits of channel availability, h(infinity-V plots indicates a substantial amount of alpha-helical structure in S2D4 (peak at 106 degrees, alpha-Periodicity Index (alpha-PI of 3.10, This conclusion is supported by alpha-PI values of 3.28 and 2.84 for the perturbations in rate constants of entry into (beta and exit from (alpha fast inactivation at 0 mV for mutant channels relative to WT channels assuming a simple two-state model for transition from the open to inactivated state. The results of cysteine substitution at the two most sensitive sites of the S2D4 alpha-helix (N1382 and E1392C support the existence of electrostatic network interactions between S2 and other transmembrane segments within Na(v1.4D4 similar to but not identical to those proposed for K+ channels.

  18. [(35)S]-GTPgammaS autoradiography reveals alpha(2) adrenoceptor-mediated G-protein activation in amygdala and lateral septum.

    Science.gov (United States)

    Newman-Tancredi, A; Chaput, C; Touzard, M; Millan, M J

    2000-04-03

    alpha(2)-adrenoceptor-mediated G-protein activation was examined by [(35)S]-GTPgammaS autoradiography. In alpha(2)-adrenoceptor-rich regions (amygdala, lateral septum), noradrenaline stimulated [(35)S]-GTPgammaS binding. These actions were abolished by the selective alpha(2) antagonist, atipamezole. Conversely, in caudate nucleus, which expresses few alpha(2) receptors, noradrenaline-induced stimulation was not inhibited by atipamezole, suggesting that it is not mediated by alpha(2)-adrenoceptors.

  19. Autokinase activity of alpha-crystallin inhibits its specific interaction with the DOTIS element in the murine gamma D/E/F-crystallin promoter in vitro.

    Science.gov (United States)

    Pietrowski, D; Graw, J

    1997-10-01

    In a previous report we demonstrated the in vitro interaction of alpha-crystallin with an element downstream of the transcriptional initiation site (DOTIS) of the murine gamma E-crystallin promoter (Pietrowski et al., 1994, Gene 144, 171-178). The aim of the present study was to investigate the influence of phosphorylation on this particular interaction. We could demonstrate that the autophosphorylation of alpha-crystallin leads to a complete loss of interaction with the DOTIS element, however, PKA-dependent phosphorylation of alpha-crystallin is without effect on the interaction. It is hypothesized that the autophosphorylation of alpha-crystallin might be involved in regulatory mechanisms of the murine gamma D/E/F-crystallin gene expression.

  20. The planar cell polarity (PCP) protein Diversin translocates to the nucleus to interact with the transcription factor AF9

    Energy Technology Data Exchange (ETDEWEB)

    Haribaskar, Ramachandran; Puetz, Michael; Schupp, Birte; Skouloudaki, Kassiani; Bietenbeck, Andreas; Walz, Gerd [Renal Division, University Hospital Freiburg, Hugstetter Strasse 55, D-79106 Freiburg (Germany); Schaefer, Tobias, E-mail: tobias.schaefer@uniklinik-freiburg.de [Renal Division, University Hospital Freiburg, Hugstetter Strasse 55, D-79106 Freiburg (Germany)

    2009-09-11

    The planar cell polarity (PCP) pathway, a {beta}-catenin-independent branch of the Wnt signaling pathway, orients cells and their appendages with respect to the body axes. Diversin, the mammalian homolog of the Drosophila PCP protein Diego, acts as a molecular switch that blocks {beta}-catenin-dependent and promotes {beta}-catenin-independent Wnt signaling. We report now that Diversin, containing several nuclear localization signals, translocates to the nucleus, where it interacts with the transcription factor AF9. Both Diversin and AF9 block canonical Wnt signaling; however, this occurs independently of each other, and does not require nuclear Diversin. In contrast, AF9 strongly augments the Diversin-driven activation of c-Jun N-terminal kinase (JNK)-dependent gene expression in the nucleus, and this augmentation largely depends on the presence of nuclear Diversin. Thus, our findings reveal that components of the PCP cascade translocate to the nucleus to participate in transcriptional regulation and PCP signaling.

  1. Interaction between hypothalamic dorsomedial nucleus and the suprachiasmatic nucleus determines intensity of food anticipatory behavior

    NARCIS (Netherlands)

    Acosta-Galvan, Guadalupe; Yi, Chun-Xia; van der Vliet, Jan; Jhamandas, Jack H.; Panula, Pertti; Angeles-Castellanos, Manuel; del Carmen Basualdo, María; Escobar, Carolina; Buijs, Ruud M.

    2011-01-01

    Food anticipatory behavior (FAA) is induced by limiting access to food for a few hours daily. Animals anticipate this scheduled meal event even without the suprachiasmatic nucleus (SCN), the biological clock. Consequently, a food-entrained oscillator has been proposed to be responsible for meal time

  2. Hard spectator interactions in B {yields} {pi}{pi} at order {alpha}{sup 2}{sub s}

    Energy Technology Data Exchange (ETDEWEB)

    Pilipp, V.

    2007-05-31

    In the present thesis I discuss the hard spectator interaction amplitude in B {yields} {pi}{pi} at NLO i.e. at O({alpha}{sup 2}{sub s}). This special part of the amplitude, whose LO starts at O({alpha}{sub s}), is defined in the framework of QCD factorization. QCD factorization allows to separate the short- and the long-distance physics in leading power in an expansion in {lambda}{sub QCD}/m{sub b}, where the short-distance physics can be calculated in a perturbative expansion in {alpha}{sub s}. Compared to other parts of the amplitude hard spectator interactions are formally enhanced by the hard collinear scale {radical}({lambda}{sub QCD}m{sub b}), which occurs next to the mb-scale and leads to an enhancement of {alpha}{sub s}. From a technical point of view the main challenges of this calculation are due to the fact that we have to deal with Feynman integrals that come with up to five external legs and with three independent ratios of scales. These Feynman integrals have to be expanded in powers of {delta}{sub QCD}/m{sub b}. I discuss integration by parts identities to reduce the number of master integrals and differential equations techniques to get their power expansions. A concrete implementation of integration by parts identities in a computer algebra system is given in the appendix. Finally I discuss numerical issues like scale dependence of the amplitudes and branching ratios. It turns out that the NLO contributions of the hard spectator interactions are important but small enough for perturbation theory to be valid. (orig.)

  3. Microwave-plasma interactions studied via mode diagnostics in ALPHA

    Energy Technology Data Exchange (ETDEWEB)

    Friesen, T., E-mail: tim.friesen@cern.ch [University of Calgary, Department of Physics and Astronomy (Canada); Andresen, G. B. [Aarhus University, Department of Physics and Astronomy (Denmark); Ashkezari, M. D. [Simon Fraser University, Department of Physics (Canada); Baquero-Ruiz, M. [University of California, Department of Physics (United States); Bertsche, W. [Swansea University, Department of Physics (United Kingdom); Bowe, P. D. [Aarhus University, Department of Physics and Astronomy (Denmark); Butler, E. [CERN, Physics Department (Switzerland); Cesar, C. L. [Universidade Federal do Rio de Janeiro, Instituto de Fisica (Brazil); Chapman, S. [University of California, Department of Physics (United States); Charlton, M.; Eriksson, S. [Swansea University, Department of Physics (United Kingdom); Fajans, J. [University of California, Department of Physics (United States); Fujiwara, M. C. [University of Calgary, Department of Physics and Astronomy (Canada); Gill, D. R. [TRIUMF (Canada); Gutierrez, A. [University of British Columbia, Department of Physics and Astronomy (Canada); Hangst, J. S. [Aarhus University, Department of Physics and Astronomy (Denmark); Hardy, W. N. [University of British Columbia, Department of Physics and Astronomy (Canada); Hayano, R. S. [University of Tokyo, Department of Physics (Japan); Hayden, M. E. [Simon Fraser University, Department of Physics (Canada); Humphries, A. J. [Swansea University, Department of Physics (United Kingdom); Collaboration: ALPHA Collaboration; and others

    2012-12-15

    The goal of the ALPHA experiment is the production, trapping and spectroscopy of antihydrogen. A direct comparison of the ground state hyperfine spectra in hydrogen and antihydrogen has the potential to be a high-precision test of CPT symmetry. We present a novel method for measuring the strength of a microwave field for hyperfine spectroscopy in a Penning trap. This method incorporates a non-destructive plasma diagnostic system based on electrostatic modes within an electron plasma. We also show how this technique can be used to measure the cyclotron resonance of the electron plasma, which can potentially serve as a non-destructive measurement of plasma temperature.

  4. Contribution to the study of alpha-alpha interaction

    International Nuclear Information System (INIS)

    Darriulai, P.

    1965-03-01

    Two sets of measurements of the α-α elastic scattering differential cross section are presented. The first set - angular distributions from 50 up to 120 MeV - shows two new resonances, 6 + and 8 + , at 25 and 57 MeV. Complex phase shifts are extracted from the data and a phenomenological potential is given. A description of the 3 α-particle 0 + states in C 12 is made with this interaction potential. The second set - excitation curves between 20 and 50 MeV - allows investigation of the Be 8 level structure within this energy range - It identifies the 16.6 and 16.9 MeV states as 2 + , but the rise of inelastic processes at higher energies makes further identification of spins and parities more and more difficult. (author) [fr

  5. Description of nuclear structure and cross sections for nucleon-nucleus scattering on the basis of effective Skyrme forces

    International Nuclear Information System (INIS)

    Kuprikov, V. I.; Pilipenko, V. V.; Soznik, A. P.; Tarasov, V. N.; Shlyakhov, N. A.

    2009-01-01

    The possibility of constructing such new versions of effective nucleon-nucleon forces that would make it possible to describe simultaneously the cross sections for nucleon-nucleus scattering and quantities characterizing nuclear matter and the structure of finite even-even nuclei is investigated on the basis of a microscopic nucleon-nucleus optical potential that is calculated by using effective Skyrme interaction. A procedure for optimizing the parameters of Skyrme forces by employing fits to specific angular distributions for neutron-nucleus scattering and by simultaneously testing the features of nuclear matter, the binding energy of the target nucleus, and its proton root-mean-square radius is proposed. A number of versions of modified Skyrme forces that ensure a reasonable description of both nucleon-nucleus scattering and the properties of nuclear structure are found on the basis of this procedure.

  6. Pion-nucleus cross sections approximation

    International Nuclear Information System (INIS)

    Barashenkov, V.S.; Polanski, A.; Sosnin, A.N.

    1990-01-01

    Analytical approximation of pion-nucleus elastic and inelastic interaction cross-section is suggested, with could be applied in the energy range exceeding several dozens of MeV for nuclei heavier than beryllium. 3 refs.; 4 tabs

  7. Characterizing alpha helical properties of Ebola viral proteins as potential targets for inhibition of alpha-helix mediated protein-protein interactions [v3; ref status: indexed, http://f1000r.es/50u

    Directory of Open Access Journals (Sweden)

    Sandeep Chakraborty

    2015-01-01

    Full Text Available Ebola, considered till recently as a rare and endemic disease, has dramatically transformed into a potentially global humanitarian crisis. The genome of Ebola, a member of the Filoviridae family, encodes seven proteins. Based on the recently implemented software (PAGAL for analyzing the hydrophobicity and amphipathicity properties of alpha helices (AH in proteins, we characterize the helices in the Ebola proteome. We demonstrate that AHs with characteristically unique features are involved in critical interactions with the host proteins. For example, the Ebola virus membrane fusion subunit, GP2, from the envelope glycoprotein ectodomain has an AH with a large hydrophobic moment. The neutralizing antibody (KZ52 derived from a human survivor of the 1995 Kikwit outbreak recognizes a protein epitope on this AH, emphasizing the critical nature of this secondary structure in the virulence of the Ebola virus. Our method ensures a comprehensive list of such `hotspots'. These helices probably are or can be the target of molecules designed to inhibit AH mediated protein-protein interactions. Further, by comparing the AHs in proteins of the related Marburg viruses, we are able to elicit subtle changes in the proteins that might render them ineffective to previously successful drugs. Such differences are difficult to identify by a simple sequence or structural alignment. Thus, analyzing AHs in the small Ebola proteome can aid rational design aimed at countering the `largest Ebola epidemic, affecting multiple countries in West Africa' (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/index.html.

  8. Attempt of analysis of the elastic scattering of 44 MeV alpha particles using a phase shift parameterization

    International Nuclear Information System (INIS)

    Papiau, Anne-Marie

    1966-01-01

    In order to ease the resolution of the problem of interaction of an alpha particle with a nucleus, and determine simpler hypotheses which enable the analysis of experimental results, this research thesis reports the use of a parameterization of phase shifts to reduce ambiguities and the number of parameters. After general remarks, a description of the Hamiltonian and a formulation of phase shifts, the author presents experimental data and the analytical method. Analysis is then performed for two-, three-, four- or five-parameter formulations. Efficient cross sections are then studied

  9. K sup + nucleus total cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Sawafta, R.

    1990-01-01

    The scattering of K{sup +} mesons from nuclei has attracted considerable interest in the last few years. The K{sup +} holds a very special position as the weakest of all strongly interaction probes. The average cross section is not larger than about 10 mb at lab momenta below 800 MeV/c, corresponding to a mean free path in the nucleus larger than 5 fm. Thus the K{sup +} is capable of probing the entire volume of the nucleus. Single scattering of the K{sup +} with a nucleon in the nucleus dominates the nuclear scattering, and only small and calculable higher order corrections are needed. The nucleon is a dynamical entity and its internal structure can, in principle, be altered by its surrounding nuclear environment. This work reports an experiment in which the K{sup +} is used to compare the nucleon in the nucleus with a free nucleon.

  10. Microscopic study of the α-16O interaction on the basis of the realistic effective interaction

    International Nuclear Information System (INIS)

    Yamaguchi, Shinichiro; Horiuchi, Hisashi; Yabana, Kazuhiro.

    1989-01-01

    We calculate the α- 16 O complex potential by the totally microscopic method where we use the many-body theory taking into account the Pauli principle explicitly and the realistic effective interactions. The comparison of the theoretical inter-nucleus potential with the phenomenological 'unique' optical potential is performed. (author)

  11. Antinucleon-nucleus elastic and inelastic scattering

    International Nuclear Information System (INIS)

    Dover, C.B.; Millener, D.J.

    1985-01-01

    A general overview of the utility of antinucleon (anti N)-nucleus inelastic scattering studies is presented, emphasizing both the sensitivity of the cross sections to various components of the N anti N transition amplitudes and the prospects for the exploration of some novel aspects of nuclear structure. We start with an examination of the relation between NN and N anti N potentials, focusing on the coherences predicted for the central, spin-orbit and tensor components, and how these may be revealed by measurements of two-body spin observables. We next discuss the role of the nucleus as a spin and isospin filter, and show how, by a judicious choice of final state quantum numbers (natural or unnatural parity states, isospin transfer ΔT = 0 or 1) and momentum transfer q, one can isolate different components of the N anti N transition amplitude. Various models for the N anti N interaction which give reasonable fits to the available two-body data are shown to lead to strikingly different predictions for certain spin-flip nuclear transitions. We suggest several possible directions for future anti N-nucleus inelastic scattering experiments, for instance the study of spin observables which would be accessible with polarized anti N beams, charge exchange reactions, and higher resolution studies of the (anti p, anti p') reaction. We compare the antinucleon and the nucleon as a probe of nuclear modes of excitation. 40 refs., 13 figs

  12. Reverse-phase HPLC analysis of human alpha crystallin.

    Science.gov (United States)

    Swamy, M S; Abraham, E C

    1991-03-01

    A rapid and highly sensitive reverse-phase HPLC (RP-HPLC) method was used to separate crystallin subunits from human alpha crystallin. Three distinct peaks were separated; by electrophoretic and immunological analyses the first and second peaks were identified as alpha B and alpha A respectively. On the other hand, peak 3 appeared to be a modified form of alpha crystallin. The ratio of alpha A and alpha B proteins was 3:1 in 1 day old lenses which gradually changed to 2:1 in 17 year old lenses and to 1:1 in the 50 and 82 year old whole lenses and 82 year old lens cortex, with a concomitant increase in the modified alpha, suggesting that alpha A subunits are relatively more involved in aggregation. Analysis of the 82 year old lens nucleus also supported this conclusion. The RP-HPLC analysis of the HMW aggregate fraction showed substantial enrichment of the modified alpha. The alpha A and alpha B subunits independently reassociated to form polymeric alpha crystallin whereas the modified alpha reassociated to form HMW aggregates as shown by molecular sieve HPLC. Hence it appears that the HMW aggregate peak was constituted by modified alpha crystallin. Only in the peak 3 material the 280 nm absorbance was about 2-fold higher than what was expected from the actual protein content. The data suggest that the changes induced by post-translational modifications may have some role in the formation of modified alpha. The present RP-HPLC method is useful in separating these modified alpha from the unmodified alpha A and alpha B subunits.

  13. WIMP-nucleus scattering in chiral effective theory

    Science.gov (United States)

    Cirigliano, Vincenzo; Graesser, Michael L.; Ovanesyan, Grigory

    2012-10-01

    We discuss long-distance QCD corrections to the WIMP-nucleon(s) interactions in the framework of chiral effective theory. For scalar-mediated WIMP-quark interactions, we calculate all the next-to-leading-order corrections to the WIMP-nucleus elastic cross-section, including two-nucleon amplitudes and recoil-energy dependent shifts to the single-nucleon scalar form factors. As a consequence, the scalar-mediated WIMP-nucleus cross-section cannot be parameterized in terms of just two quantities, namely the neutron and proton scalar form factors at zero momentum transfer, but additional parameters appear, depending on the short-distance WIMP-quark interaction. Moreover, multiplicative factorization of the cross-section into particle, nuclear and astro-particle parts is violated. In practice, while the new effects are of the natural size expected by chiral power counting, they become very important in those regions of parameter space where the leading order WIMP-nucleus amplitude is suppressed, including the so-called "isospin-violating dark matter" regime. In these regions of parameter space we find order-of-magnitude corrections to the total scattering rates and qualitative changes to the shape of recoil spectra.

  14. Thioredoxin, thioredoxin reductase, and alpha-crystallin revive inactivated glyceraldehyde 3-phosphate dehydrogenase in human aged and cataract lens extracts.

    Science.gov (United States)

    Yan, Hong; Lou, Marjorie F; Fernando, M Rohan; Harding, John J

    2006-10-02

    To investigate whether mammalian thioredoxin (Trx) and thioredoxin reductase (TrxR), with or without alpha-crystallin can revive inactivated glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in both the cortex and nucleus of human aged clear and cataract lenses. The lens cortex (including capsule-epithelium) and the nucleus were separated from human aged clear and cataract lenses (grade II and grade IV) with similar average age. The activity of GAPDH in the water-soluble fraction after incubation with or without Trx or/and TrxR for 60 min at 30 degrees C was measured spectrophotometrically. In addition, the effect of a combination of Trx/TrxR and bovine lens alpha-crystallin was investigated. GAPDH activity was lower in the nucleus of clear lenses than in the cortex, and considerably diminished in the cataractous lenses, particularly in the nucleus of cataract lenses grade IV. Trx and TrxR were able to revive the activity of GAPDH markedly in both the cortex and nucleus of the clear and cataract lenses. The percentage increase of activity in the cortex of the clear lenses was less than that of the nucleus in the presence of Trx and TrxR, whereas it was opposite in the cataract lenses. The revival of activity in both the cortex and nucleus from the cataract lenses grade II was higher than that of the grade IV. Moreover, Trx alone, but not TrxR, efficiently enhanced GAPDH activity. The combination of Trx and TrxR had greater effect than that of either alone. In addition, alpha(L)-crystallin enhanced the activity in the cortex of cataract grade II with Trx and TrxR present. However, it failed to provide a statistically significant increase of activity in the nucleus. This is the first evidence to show that mammalian Trx and TrxR are able to revive inactivated GAPDH in human aged clear and cataract lenses, and alpha-crystallin helped this effect. The inactivation of GAPDH during aging and cataract development must be caused in part by disulphide formation and in part by

  15. Alpha2-adrenoceptor modulation of long-term potentiation elicited in vivo in rat occipital cortex.

    Science.gov (United States)

    Mondaca, Mauricio; Hernández, Alejandro; Pérez, Hernán; Valladares, Luis; Sierralta, Walter; Fernández, Victor; Soto-Moyano, Rubén

    2004-09-24

    Pretreatment with the alpha(2)-adrenoceptor agonist clonidine (31.25, 62.5, or 125 microg/kg, i.p.) dose-dependently reduced long-term potentiation (LTP) elicited in vivo in the occipital cortex of anesthetized rats, whereas pretreatment with the alpha(2)-adrenoceptor antagonist yohimbine (0.133, 0.4, or 1.2 mg/kg, i.p.) increased neocortical LTP in a dose-dependent fashion. These effects could be related to the reported disruptive and facilitatory actions induced on memory formation by pretreatment with alpha(2)-adrenoceptor agonists and antagonists, respectively.

  16. Involvement of the subthalamic nucleus in impulse control disorders associated with Parkinson's disease.

    Science.gov (United States)

    Rodriguez-Oroz, Maria C; López-Azcárate, Jon; Garcia-Garcia, David; Alegre, Manuel; Toledo, Jon; Valencia, Miguel; Guridi, Jorge; Artieda, Julio; Obeso, Jose A

    2011-01-01

    Behavioural abnormalities such as impulse control disorders may develop when patients with Parkinson's disease receive dopaminergic therapy, although they can be controlled by deep brain stimulation of the subthalamic nucleus. We have recorded local field potentials in the subthalamic nucleus of 28 patients with surgically implanted subthalamic electrodes. According to the predominant clinical features of each patient, their Parkinson's disease was associated with impulse control disorders (n = 10), dyskinesias (n = 9) or no dopaminergic mediated motor or behavioural complications (n = 9). Recordings were obtained during the OFF and ON dopaminergic states and the power spectrum of the subthalamic activity as well as the subthalamocortical coherence were analysed using Fourier transform-based techniques. The position of each electrode contact was determined in the postoperative magnetic resonance image to define the topography of the oscillatory activity recorded in each patient. In the OFF state, the three groups of patients had similar oscillatory activity. By contrast, in the ON state, the patients with impulse control disorders displayed theta-alpha (4-10 Hz) activity (mean peak: 6.71 Hz) that was generated 2-8 mm below the intercommissural line. Similarly, the patients with dyskinesia showed theta-alpha activity that peaked at a higher frequency (mean: 8.38 Hz) and was generated 0-2 mm below the intercommissural line. No such activity was detected in patients that displayed no dopaminergic side effects. Cortico-subthalamic coherence was more frequent in the impulsive patients in the 4-7.5 Hz range in scalp electrodes placed on the frontal regions anterior to the primary motor cortex, while in patients with dyskinesia it was in the 7.5-10 Hz range in the leads overlying the primary motor and supplementary motor area. Thus, dopaminergic side effects in Parkinson's disease are associated with oscillatory activity in the theta-alpha band, but at different

  17. The nucleus as a laboratory

    International Nuclear Information System (INIS)

    Blin-Stoyle, R.J.

    1979-01-01

    The nucleus is a complicated many-body structure whose properties when carefully studied can frequently give important information about the underlying elementary particle interactions. This article reviews progress in research of this kind over the last twenty-five years. (author)

  18. Excitation functions for alpha-particle-induced reactions with natural antimony

    Energy Technology Data Exchange (ETDEWEB)

    Singh, N. L.; Shah, D. J.; Mukherjee, S.; Chintalapudi, S. N. [Vadodara, M. S. Univ. of Baroda (India). Fac. of Science. Dept. of Physics

    1997-07-01

    Stacked-foil activation technique and {gamma} - rays spectroscopy were used for the determination of the excitation functions of the {sup 121}Sb [({alpha}, n); ({alpha}, 2n); ({alpha},4 n); ({alpha}, p3n); ({alpha}, {alpha}n)]; and Sb [({alpha}, 3n); ({alpha}, 4n); ({alpha}, {alpha}3n)] reactions. The excitation functions for the production of {sup 124}I, {sup 123}I, {sup 121}I, {sup 121}Te and {sup 120}Sb were reported up to 50 MeV. The reactions {sup 121} Sb ({alpha}, {alpha}n) + {sup 123} Sb ({alpha}, {alpha}3n) are measured for the first time. Since natural antimony used as the target has two odd mass stable isotopes of abundances 57.3 % ({sup 121}Sb), their activation in some cases gives the same product nucleus through different reaction channels but with very different Q-values. In such cases, the individual reaction cross-sections are separated with the help of theoretical cross-sections. The experimental cross-sections were compared with the predictions based on hybrid model of Blann. The high-energy part of the excitation functions are dominated by the pre-equilibrium reaction mechanism and the initial exciton number n{sub 0} = 4 (4 p 0 h) gives fairly good agreement with presently measured results.

  19. Unified semimicroscopic approach scattering of low energy protons and alpha-particles by nuclei

    International Nuclear Information System (INIS)

    Dao Tien Khoa; Kukhtina, I.N.; Knyaz'kov, O.M.; Feofilov, G.A.

    1988-01-01

    The unified approach has been developed to the description of the interaction of low energy nucleons and α-particles with nuclei. The analysis of elastic and inelastic scattering of 25.05 MeV protons and 104 MeV α-particles from 90 Zr is made. The differences in deformations of neutron and proton density distributions for 90 Zr nucleus are extracted. The energy dependence of the obtained α-particle - nucleus semimicroscopic potential is investigated, including the energy dependence for the geometry of the potential. The feaures of angular distributions of elastic α-particle scattering and the role of nucleon-nucleon correlations are analysed as a function of α-particle energy

  20. Molecular orbitals of nucleons in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Imanishi, B.; Oertzen, W. von.

    1986-05-01

    A formalism for the dynamical treatment of the molecular orbitals of valence nucleons in nucleus-nucleus collisions at low bombarding energy is developed with the use of the coupled-reaction-channel (CRC) method. The Coriolis coupling effects as well as the finite mass effects of the nucleon are taken into account in this model, of rotating molecular orbitals, RMO. First, the validity of the concept is examined from the view point of the multi-step processes in a standard CRC calculation for systems containing two identical [core] nuclei. The calculations show strong CRC effects particularly in the case where the mixing of different l-parity orbitals - called hybridization in atomic physics - occurs. Then, the RMO representation for active nucleons is applied to the same systems and compared to the CRC results. Its validity is investigated with respect to the radial motion (adiabaticity) and the rotation of the molecular axis (radial and rotational coupling). Characteristic molecular orbitals of covalent molecules appear as rotationally stable states (K = 1/2) with good adiabaticity. Using the RMO's we obtain a new interpretation of various scattering phenomena. Dynamically induced changes in the effective Q-values (or scaling of energies), dynamically induced moments of inertia and an dynamically induced effective (L · S) interaction are obtained as a result of the molecular orbital formation. Various experimental data on transfer and subbarrier fusion reactions are understood in terms of the RMO's and their adiabatic potentials. Landau-Zener transitions, which strongly depend on the total angular momentum of the system, definitely predict the observation of characteristic changes in the cross sections for the inelastic scattering 13 C( 12 C, 12 C) 13 C* (3.086 MeV, 1/2 + ) with the change of the bombarding energy. (author)

  1. Transport of glutathione into the nucleus.

    Science.gov (United States)

    Queval, Guillaume; Foyer, Christine

    2014-10-01

    The tripeptide thiol glutathione (GSH) is present in the nucleus of plant and animal cells. However, the functions of GSH in the nucleus remain poorly characterised. GSH appears to become sequestered in the nucleus at the early stages of the cell cycle. As part of our search for proteins that may be involved in GSH transport into the nucleus, we studied the functions of the nucleoporin called Alacrima Achalasia aDrenal Insufficiency Neurologic disorder (ALADIN). ALADIN is encoded by the Achalasia-Addisonianism-Alacrimia (AAAS) gene in mammalian cells. Defects in ALADIN promote adrenal disorders and lead to the triple A syndrome in humans. The ALADIN protein localizes to the nuclear envelope in Arabidopsis thaliana and interacts with other components of the nuclear pore complex (NPC). We characterised the functions of the ALADIN protein in an Arabidopsis thaliana T-DNA insertion knockout mutant, which shows slow growth compared to the wild type. Copyright © 2014. Published by Elsevier Inc.

  2. Interaction of a gibberellin-induced factor with the upstream region of an alpha-amylase gene in rice aleurone tissue.

    OpenAIRE

    Ou-Lee, T M; Turgeon, R; Wu, R

    1988-01-01

    The interaction between the DNA sequences of an alpha-amylase (EC 3.2.1.1) gene and a tissue-specific factor induced in rice (Oryza sativa L.) aleurone tissue by gibberellin was studied. DNA mobility-shift during electrophoresis indicated that a 500-base-pair sequence (HS500) of a rice alpha-amylase genomic clone (OSamy-a) specifically interacted with a factor from gibberellin-induced rice aleurone tissue. The amount of complex formed between the HS500 DNA fragment and the gibberellin-induced...

  3. Mechanisms of the p(He 6,He 5)d, p(He 6,{alpha})t and p(He 6,t){alpha} reactions

    Energy Technology Data Exchange (ETDEWEB)

    Heiberg-Andersen, Henning

    2002-07-01

    This work was devoted to nucleon induced transfer reactions having the potential to probe the sub-cluster structures of the benchmark halo nucleus He 6, without the question marks the necessarily omitted exchange effects tend to put behind the CRC results when both collision partners are composite systems. Still, the exchange complications entered the analysis in an ironic way: The high Q-value of the p(He 6,{alpha})t and p(He 6, t){alpha} reactions caused sensitivity to the t - {alpha} optical potential at small radii, where the one-nucleon exchange effects are strongest. Since the attempt to throw them out of the extracted tau - {alpha} potential failed, it was necessary to extend the model space to avoid a too difficult modelling of the local equivalent t - {alpha} potential. By this step, all the complications originating from antisymmetrization within a larger model space entered the analysis. However, the persistent failures of the two-channel calculations of this and previous works can hardly be due to incorrect treatment of exchange effects only, so the loss of simplicity is probably illusory. Even at small angles, where the surface processes dominate, none of the two-channel calculations with various choices of t - {alpha} optical potentials managed to reproduce the p(He 6, {alpha})t (p(He 6,t){alpha}) data. This motivated inclusion of sequential transfers through the d + He 5 channel, where the sequential triton transfer process, included just for consistency in the coupling scheme of the four-channel calculation, turned out to be more influent than expected. The satisfactory reproduction of both the p(He 6, He 5)d and the p(He 6,{alpha})t (p(He 6,t){alpha}) data by the four-channel approach and the required re-normalization the real part of the p - He 6 optical potential are strong indications of substantial contributions from sequential transfer of the halo neutrons at this energy. The conclusions that can be drawn from this work are limited by the

  4. Use of track-end alpha particles from 241Am to study radiosensitive sites in CHO cells

    International Nuclear Information System (INIS)

    Datta, R.; Cole, A.; Robinson, S.

    1976-01-01

    Monolayers of CHO cells placed on membrane filters were irradiated with alpha particles from a 241 Am source. Particle penetration into the cells was controlled by placing the cell sample at various distances from the source. Dosimetric and spectrometric measurements were performed at comparable positions using a parallel plate ionization chamber and a scintillation crystal spectrometer. Cell survival, as measured by conventional cloning techniques, was single hit in form. A pronounced minimum in mean lethal dose of 29 rad was observed for alpha particle beams that penetrated only about 3 μm into the cell. A pronounced maximum in inactivation cross section of 90 μm 2 , equal to about half the projected area of the nucleus, occurred for beams that penetrated only 5 to 7 μm into the cell. Thus, a single alpha particle penetration several micrometers within the cell nucleus was effective in killing the cell, while fully penetrating beams were actually less efficient; the latter beams required multiple particle traversals and about three times the cell dose to achieve the same effect. These results support the proposal that radiosensitive sites are located in a thin peripheral region of the nucleus

  5. Reaction /sup 56/Fe (. gamma. ,. cap alpha. /sub 0/) and /sup 56/Fe (. gamma. , p/sub 0/)

    Energy Technology Data Exchange (ETDEWEB)

    Tamae, T; Sugawara, M [Tohoku Univ., Sendai (Japan). Lab. of Nuclear Science; Tsubota, H

    1975-06-01

    Precise analysis was made on the cross section of the /sup 56/Fe (..gamma.., ..cap alpha../sub 0/) reaction and the angular distribution at Esub(e) = 17 MeV, including the systematic error. The (..gamma.., ..cap alpha../sub 0/) reaction cross section was compared with a calculation using the compound nucleus model, utilizing the photon absorption cross section derived from the experimental values of /sup 56/Fe (..gamma.., n) and /sup 56/Fe (..gamma.., p) cross sections. From the (..gamma.., ..cap alpha../sub 0/) reaction cross section data of various nuclei, an empirical formula was obtained for determining the position of a peak in the (..gamma.., ..cap alpha../sub 0/) reaction cross section. The /sup 56/Fe (..gamma.., p/sub 0/) reaction cross section measured at an excitation energy in the range of 14.6--25.0 MeV was compared with the calculated one with the compound nucleus model, but the form and size differ totally.

  6. Model for nucleus-nucleus, hadron-nucleus and hadron-proton multiplicity distributions

    International Nuclear Information System (INIS)

    Singh, C.P.; Shyam, M.; Tuli, S.K.

    1986-07-01

    A model relating hadron-proton, hadron-nucleus and nucleus-nucleus multiplicity distributions is proposed and some interesting consequences are derived. The values of the parameters are the same for all the processes and are given by the QCD hypothesis of ''universal'' hadronic multiplicities which are found to be asymptotically independent of target and beam in hadronic and current induced reactions in particle physics. (author)

  7. Toward relating the subthalamic nucleus spiking activity to the local field potentials acquired intranuclearly

    International Nuclear Information System (INIS)

    Michmizos, K P; Nikita, K S; Sakas, D

    2011-01-01

    Studies on neurophysiological correlates of the functional magnetic resonance imaging (fMRI) signals reveal a strong relationship between the local field potential (LFP) acquired invasively and metabolic signal changes in fMRI experiments. Most of these studies failed to reveal an analogous relationship between metabolic signals and the spiking activity. That would allow for the prediction of the neural activity exclusively from the fMRI signals. However, the relationship between fMRI signals and spiking activity can be inferred indirectly provided that the LFPs can be used to predict the spiking activity of the area. Until now, only the LFP–spike relationship in cortical areas has been examined. Herein, we show that the spiking activity can be predicted by the LFPs acquired in a deep nucleus, namely the subthalamic nucleus (STN), using a nonlinear cascade model. The model can reproduce the spike patterns inside the motor area of the STN that represent information about the motor plans. Our findings expand the possibility of further recruiting non-invasive neuroimaging techniques to understand the activity of the STN and predict or even control movement

  8. Contributions to the study of heavy and superheavy nuclei stability in alpha-decay

    International Nuclear Information System (INIS)

    Silisteanu, I.

    1978-01-01

    Alpha-decay is treated in this work on the complete analogy of transfer reactions by means of nuclear shell models with continuous spectrum nucleons. Certain phenomenologically obtained or microscope evaluated data on low energy interactions between alpha-particles and nuclei, when related to nuclear structure data within the unified theory of nuclear reactions, allow of an improved accuracy in determining the alpha-particle wave function as well as of an estimation of alpha-probabilities in good keeping with experimental ones. The problem of alpha lifetimes thus narrows to the resolution of some homogeneous and inhomogeneous differential equations systems including the optic potential and the alpha formfactors. (author)

  9. High energy hadron-nucleus scattering

    International Nuclear Information System (INIS)

    Koplik, J.; Mueller, A.H.

    1975-01-01

    Theoretical expectations for hadron-nucleus scattering at high energy if the basic hadron-hadron interaction is due to Regge poles and cuts arising in multiperipheral or soft field theory models are described. Experiments at Fermilab may provide a critical test of such models

  10. Influence of neutron halo in the interaction of 6He nucleus of 35 MeV/nucleon with 197Au and 238U

    International Nuclear Information System (INIS)

    Perier, Yann

    1997-01-01

    In this study, we have attempted to answer some of the questions still open concerning neutron halo nuclei. The interest of the latter lies in their very peculiar structure. The analysis of the kinematical features of the halo nucleus fragments originating from the dissociation following the interaction with a target nucleus is an essential tool for probing this structure. We studied the 6 He + Au, U at 35 A.MeV system with a new method. Simultaneous measurements of the halo nucleus core, the halo neutrons and the excitation energy deposited in the target nucleus assessed with ORION allowed us to obtain information about the formation of the 5 He nucleus and about the partial validity of the sudden approximation at moderate bombarding energy. The study of the core nucleus and neutron angular distributions confirmed that it is difficult to extract information on the internal structure at the halo neutrons from their widths. The halo neutron longitudinal momentum distributions were studied. Their widths were found to increase as the impact parameter decreases. The 4 He - core parallel momentum distributions were also investigated. The widths are weakly dependent on the excitation energy deposited in the target nucleus, but increase with the 4 He emission angle as for the halo neutrons. The ratio between one- and two-neutron stripping cross sections seems to indicate that the two halo neutrons are strongly correlated with a large dineutron component, as ascertained by a calculation in the framework of the Serber model. (author)

  11. Interaction between TNF and BmooMP-Alpha-I, a Zinc Metalloprotease Derived from Bothrops moojeni Snake Venom, Promotes Direct Proteolysis of This Cytokine: Molecular Modeling and Docking at a Glance

    Directory of Open Access Journals (Sweden)

    Maraisa Cristina Silva

    2016-07-01

    Full Text Available Tumor necrosis factor (TNF is a major cytokine in inflammatory processes and its deregulation plays a pivotal role in several diseases. Here, we report that a zinc metalloprotease extracted from Bothrops moojeni venom (BmooMP-alpha-I inhibits TNF directly by promoting its degradation. This inhibition was demonstrated by both in vitro and in vivo assays, using known TLR ligands. These findings are supported by molecular docking results, which reveal interaction between BmooMP-alpha-I and TNF. The major cluster of interaction between BmooMP-alpha-I and TNF was confirmed by the structural alignment presenting Ligand Root Mean Square Deviation LRMS = 1.05 Å and Interactive Root Mean Square Deviation IRMS = 1.01 Å, this result being compatible with an accurate complex. Additionally, we demonstrated that the effect of this metalloprotease on TNF is independent of cell cytotoxicity and it does not affect other TLR-triggered cytokines, such as IL-12. Together, these results indicate that this zinc metalloprotease is a potential tool to be further investigated for the treatment of inflammatory disorders involving TNF deregulation.

  12. Higgs-boson production in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Cross section calculations are presented for the production of intermediate-mass Higgs bosons produced in ultrarelativistic nucleus-nucleus collisions via two photon fusion. The calculations are performed in position space using Baur's method for folding together the Weizsacker-Williams virtual-photon spectra of the two colliding nuclei. It is found that two photon fusion in nucleus-nucleus collisions is a plausible way of finding intermediate-mass Higgs bosons at the Superconducting Super Collider or the CERN Large Hadron Collider

  13. Higgs-Boson Production in Nucleus-Nucleus Collisions

    Science.gov (United States)

    Norbury, John W.

    1992-01-01

    Cross section calculations are presented for the production of intermediate-mass Higgs bosons produced in ultrarelativistic nucleus-nucleus collisions via two photon fusion. The calculations are performed in position space using Baur's method for folding together the Weizsacker-Williams virtual-photon spectra of the two colliding nuclei. It is found that two photon fusion in nucleus-nucleus collisions is a plausible way of finding intermediate-mass Higgs bosons at the Superconducting Super Collider or the CERN Large Hadron Collider.

  14. UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE binds to alpha-actinin 1: novel pathways in skeletal muscle?

    Directory of Open Access Journals (Sweden)

    Shira Amsili

    Full Text Available BACKGROUND: Hereditary inclusion body myopathy (HIBM is a rare neuromuscular disorder caused by mutations in GNE, the key enzyme in the biosynthetic pathway of sialic acid. While the mechanism leading from GNE mutations to the HIBM phenotype is not yet understood, we searched for proteins potentially interacting with GNE, which could give some insights about novel putative biological functions of GNE in muscle. METHODOLOGY/PRINCIPAL FINDINGS: We used a Surface Plasmon Resonance (SPR-Biosensor based assay to search for potential GNE interactors in anion exchanged fractions of human skeletal muscle primary culture cell lysate. Analysis of the positive fractions by in vitro binding assay revealed alpha-actinin 1 as a potential interactor of GNE. The direct interaction of the two proteins was assessed in vitro by SPR-Biosensor based kinetics analysis and in a cellular environment by a co-immunoprecipitation assay in GNE overexpressing 293T cells. Furthermore, immunohistochemistry on stretched mouse muscle suggest that both GNE and alpha-actinin 1 localize to an overlapping but not identical region of the myofibrillar apparatus centered on the Z line. CONCLUSIONS/SIGNIFICANCE: The interaction of GNE with alpha-actinin 1 might point to its involvement in alpha-actinin mediated processes. In addition these studies illustrate for the first time the expression of the non-muscle form of alpha-actinin, alpha-actinin 1, in mature skeletal muscle tissue, opening novel avenues for its specific function in the sarcomere. Although no significant difference could be detected in the binding kinetics of alpha-actinin 1 with either wild type or mutant GNE in our SPR biosensor based analysis, further investigation is needed to determine whether and how the interaction of GNE with alpha-actinin 1 in skeletal muscle is relevant to the putative muscle-specific function of alpha-actinin 1, and to the muscle-restricted pathology of HIBM.

  15. [G-protein potentiates the activation of TNF-alpha on calcium-activated potassium channel in ECV304].

    Science.gov (United States)

    Lin, L; Zheng, Y; Qu, J; Bao, G

    2000-06-01

    Observe the effect of tumor necrosis factor-alpha (TNF-alpha) on calcium-activated potassium channel in ECV304 and the possible involvement of G-protein mediation in the action of TNF-alpha. Using the cell-attached configuration of patch clamp technique. (1) the activity of high-conductance calcium-activated potassium channel (BKca) was recorded. Its conductance is (202.54 +/- 16.62) pS; (2) the activity of BKca was potentiated by 200 U/ml TNF-alpha; (3) G-protein would intensify this TNF-alpha activation. TNF-alpha acted on vascular endothelial cell ECV304 could rapidly activate the activity of BKca. Opening of BKca resulted in membrane hyper-polarization which could increase electro-chemical gradient for the resting Ca2+ influx and open leakage calcium channel, thus resting cytoplasmic free Ca2+ concentration could be elevated. G-protein may exert an important regulation in this process.

  16. Alpha 2-adrenoceptor blockade, pituitary-adrenal hormones, and agonistic interactions in rats.

    Science.gov (United States)

    Haller, J; Barna, I; Kovács, J L

    1994-08-01

    The effects of adrenergic activation on aggressiveness and the aggression induced endocrine changes were tested in rats. Alpha 2 adrenoceptor blockers were used for enhancing activation of the adrenergic system, and changes in aggressiveness were tested in resident-intruder contests. Three experiments were conducted. In experiment 1, saline injected rats responded to the presence of an opponent by aggression and the increase in plasma ACTH and corticosterone. Intraperitoneal administration of 1 mg/kg CH-38083 (an alpha 2 adrenoceptor antagonist) produced a several fold increase in clinch fighting and mutual upright scores, and also further enhanced the plasma ACTH and corticosterone response. In experiment 2, the effect of three doses (0.5, 1 and 2 mg/kg) of three different alpha 2 adrenoceptor blockers CH-38083, idazoxan and yohimbine were tested. All the substances increased aggression at 0.5 and 1 mg/kg; at 2 mg/kg the effect of idazoxan and yohimbine disappeared, while with CH-38083 an additional increase was obtained. In yohimbine treated animals the enhancement of aggression was reduced already at 1 mg/kg. In experiment 3, indomethacin, a potent inhibitor of the catecholamine-induced ACTH release completely abolished the effects of the alpha 2 adrenoceptor antagonist CH-38083: the intensity of agonistic interactions, as well as ACTH and corticosterone plasma concentrations, returned to control levels. The possible role of catecholamines and the stress hormones in the activation of aggression is discussed.

  17. Calculations of antiproton-nucleus quasi-bound states using the Paris N bar N potential

    Science.gov (United States)

    Hrtánková, Jaroslava; Mareš, Jiří

    2018-01-01

    An optical potential constructed using the p bar N scattering amplitudes derived from the 2009 version of the Paris N bar N potential is applied in calculations of p bar quasi-bound states in selected nuclei across the periodic table. A proper self-consistent procedure for treating energy dependence of the amplitudes in a nucleus appears crucial for evaluating p bar binding energies and widths. Particular attention is paid to the role of P-wave amplitudes. While the P-wave potential nearly does not affect calculated p bar binding energies, it reduces considerably the corresponding widths. The Paris S-wave potential supplemented by a phenomenological P-wave term yields in dynamical calculations p bar binding energies Bpbar ≈ 200 MeV and widths Γpbar ∼ 200- 230 MeV, which is very close to the values obtained within the RMF model consistent with p bar -atom data.

  18. A study of multiplicity scaling of particles produced in 16O-nucleus collisions

    International Nuclear Information System (INIS)

    Ahmad, N.

    2015-01-01

    Koba-Nielsen-Olesen (KNO) scaling has been a dominant framework to study the behaviour of multiplicity distribution of charged particles produced in high-energy hadronic collisions. Several workers have made attempt to investigate multiplicity distributions of particles produced in hadron-hadron (h-h), hadron-nucleus (h-A) and nucleus-nucleus (A-A) collisions at relativistic energies. Multiplicity distributions in p-nucleus interactions in emulsion experiments are found to be consistent with the KNO scaling. The applicability of the scaling of multiplicities was extended to FNL energies by earlier workers. Slattery has shown that KNO scaling is in agreement with the data on pp interactions over a wide-range of energies

  19. Functional discrepancies between tumor necrosis factor and lymphotoxin alpha explained by trimer stability and distinct receptor interactions

    DEFF Research Database (Denmark)

    Schuchmann, M; Hess, S; Bufler, P

    1995-01-01

    Tumor necrosis factor (TNF) and lymphotoxin alpha (LT alpha) are closely related cytokines which bind with nearly identical affinities to the same pair of cell surface receptors, p55 and p75TNFR. Therefore it is assumed that TNF and LT alpha are redundant cytokines. This study, however......, demonstrates that TNF and LT alpha differ significantly with regard to their mitogenic and cytotoxic potentials. LT alpha's superior mitogenic effect could be explained by its formation of a more stable trimer. In contrast to the TNF trimer, which disintegrated under physiological conditions into biologically...... inactive monomers, the LT alpha trimer remained stable for several days. Accordingly, LT alpha more effectively induced fibroblast growth which demands long-term presence of the cytokine. TNF's superior cytotoxicity, which requires only short-term impact of the cytokine, could be attributed to a distinct...

  20. New results on nuclear multifragmentation in nucleon-nucleus and nucleus-nucleus collisions at relativistic energies

    International Nuclear Information System (INIS)

    Besliu, Calin; Jipa, Alexandru; Iliescu, Bogdan; Felea, Daniel

    2002-01-01

    Some new aspects on the multifragmentation processes in nucleus-nucleus and nucleon-nucleus collisions at high energies are discussed in this work. Experimental data obtained in international collaborations (for example, MULTI Collaboration with KEK Tsukuba (Japan) and SKM 200 Collaboration with JINR Dubna (Russia)) are used to discuss new mechanisms in the target nucleus fragmentation. Correlations with stopping power, participant region size and energy density are included. Comparisons of the experimental results with the predictions of a phenomenological geometric model of intermediate mass fragment multiplicity, caloric curves and angular distributions are also presented. These results are used for global description of the multifragmentation processes in nucleon-nucleus and nucleus-nucleus collisions at relativistic energies. The size of the participant region and the average intermediate mass fragments multiplicity are taken into consideration using the free space probability. A few correlations between the deposited energy in the participant region and stability state of the intermediate mass fragments are presented in this work. The importance of the collision geometry in the multifragmentation processes is stressed. The results suggest different time moments for the incident nucleus fragmentation and for the target nucleus fragmentation. The associated entropies are distinct. (authors)

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

    Science.gov (United States)

    Kurudirek, Murat; Onaran, Tayfur

    2015-07-01

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

  2. Interaction of the alpha-toxin of Staphylococcus aureus with the liposome membrane.

    Science.gov (United States)

    Ikigai, H; Nakae, T

    1987-02-15

    When the liposome membrane is exposed to the alpha-toxin of Staphylococcus aureus, fluorescence of the tryptophan residue(s) of the toxin molecule increases concomitantly with the degree of toxin-hexamer formation (Ikigai, H., and Nakae, T. (1985) Biochem. Biophys. Res. Commun. 130, 175-181). In the present study, the toxin-membrane interaction was distinguished from the hexamer formation by the fluorescence energy transfer from the tryptophan residue(s) of the toxin molecule to the dansylated phosphatidylethanolamine in phosphatidylcholine liposome. Measurement of these two parameters yielded the following results. The effect of the toxin concentration and phospholipid concentration on these two parameters showed first order kinetics. The effect of liposome size on the energy transfer and the fluorescence increment of the tryptophan residue(s) was only detectable in small liposomes. Under moderately acidic or basic conditions, the fluorescence energy transfer always preceded the fluorescence increment of the tryptophan residue(s). The fluorescence increment at 336 nm at temperatures below 20 degrees C showed a latent period, whereas the fluorescence energy transfer did not. These results were thought to indicate that when alpha-toxin damages the target membrane, the molecule interacts with the membrane first, and then undergoes oligomerization within the membrane.

  3. Spin reorientation in α-Fe2O3 nanoparticles induced by interparticle exchange interactions in alpha-Fe2O3/NiO nanocomposites

    DEFF Research Database (Denmark)

    Frandsen, Cathrine; Lefmann, Kim; Lebech, Bente

    2011-01-01

    We report that the spin structure of alpha-Fe2O3 nanoparticles rotates coherently out of the basal (001) plane at low temperatures when interacting with thin plate-shaped NiO nanoparticles. The observed spin reorientation (up to similar to 70 degrees) in alpha-Fe2O3 nanoparticles has, in appearan......, similarities to the Morin transition in bulk alpha-Fe2O3, but its origin is different-it is caused by exchange coupling between aggregated nanoparticles of alpha-Fe2O3 and NiO with different directions of easy axes of magnetization.......We report that the spin structure of alpha-Fe2O3 nanoparticles rotates coherently out of the basal (001) plane at low temperatures when interacting with thin plate-shaped NiO nanoparticles. The observed spin reorientation (up to similar to 70 degrees) in alpha-Fe2O3 nanoparticles has, in appearance...

  4. A new potential of π-nucleus scattering and its application to nuclear structure study using elastic scattering and charge exchange reactions

    International Nuclear Information System (INIS)

    Durand, Gerard.

    1974-01-01

    First the different theories used for studying pion-nucleus scattering and especially Glauber microscopic model and Kisslinger optical model are summarized. From the comparison of these two theories it was concluded that Kisslinger's was better for studying pion-nucleus scattering near the (3/2-3/2) resonance. The potential was developed, with a local corrective term, proposed by this author. This new term arises from taking into account correctly the Lorentz transformation from the pion-nucleon center of mass to the pion nucleus center of mass system. A coupled-channel formalism was developed allowing the study of pion-nucleus elastic scattering and also the study of single and double charge exchange reactions on nucleus with N>Z. The influence of the new term and the shape of nucleon densities on π- 12 C scattering was studied near 200MeV. It was found that at the nucleus surface the neutron density was larger than the proton density. On the other hand, a maximum of sensibility to the different nuclear parameters was found near 180MeV and for elastic scattering angles greater than 100 deg. The calculations of the total cross section for simple and double charge exchange for 13 C and 63 Cu yielded results simular to those of previous theories and showed the same discrepancy between theory and experiment in the resonance region [fr

  5. Local and non-local potentials for deuteron elastic scattering

    International Nuclear Information System (INIS)

    Ramirez, J.A.

    1976-01-01

    The nucleon--nucleus local potential (central and spin--orbit) and the deuteron--nucleus nonlocal potential (central, spin--orbit, spin--radial tensor) are calculated by the folding-model (FM). Simple analytic expressions are obtained for the nucleon--nucleus potential by the use of Gaussians to represent the nucleon--nucleus potential and the charge and mass densities of the target. The analytic expressions give qualitative descriptions of phenomenological nucleon--nucleus interactions. A systematic target--mass dependence of realistic local FM deueron potentials is also included. Local-equivalent, energy-dependent, deuteron potentials are obtained from the nonlocal FM deuteron potentials and the energy dependence of the local potential parameters are presented. The local FM deuteron potential is tested for 60 Ni(d,d) 60 Ni at E/sub α/ = 15 MeV by comparing the predictions of the FM potentials with data in which all five polarization moments were measured. A qualitative fit to the data is obtained, but it overestimates the volume integral of the central potential by 7%. Energy-dependence effects are estimated by evaluating the local-equivalent potentials at E/sub α/ = 30 MeV and comparing the predictions to the E/sub α/ = 15 MeV potentials. The energy dependence of the central potential dominates the angular dependence of all five observables while the energy dependence of the spin--orbit and tensor potentials produces only scale changes (approx. 3%) in the vector and tensor analyzing powers. The scattering formalism for a spin-1 on a spin-0 target nucleus, and a description of the coupled--channels computer code DDUNC1 which treats the spin--radial tensor potential exactly, are included

  6. Regulation of Arterial Pressure By The Paraventricular Nucleus in Conscious Rats: Interactions Among Glutamate, GABA, and Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Marli Cardoso Martins-Pinge

    2013-01-01

    Full Text Available The paraventricular nucleus (PVN of the hypothalamus is an important site for autonomic and neuroendocrine regulation. Experiments in anesthetized animals and in vitro indicate an interaction among gamma-aminobutyric acid (GABA, nitric oxide (NO and glutamate in the PVN. The cardiovascular role of the PVN and interactions of these neurotransmitters in conscious animals have not been evaluated fully. In chronically instrumented conscious rats, mean arterial pressure (MAP and heart rate (HR responses to microinjections (100 nl in the region of the PVN were tested. Bilateral blockade of ionotropic excitatory amino acid (EAA receptors (kynurenic acid, Kyn in the PVN produced small but significant decreases in MAP and HR. GABAA receptor blockade (bicuculline, Bic, and inhibition of NO synthase (N-(G-monomethyl-L-arginine, L-NMMA each increased MAP and HR. The NO donor sodium nitroprusside (SNP produced depressor responses that were attenuated by Bic. NO synthase inhibition potentiated both pressor responses to the selective EAA agonist, N-methyl-D-aspartic acid (NMDA, and depressor responses to Kyn. Increases in MAP and HR due to Bic were blunted by prior blockade of EAA receptors. Thus, pressor responses to GABA blockade require EAA receptors and GABA neurotransmission contributes to NO inhibition. Tonic excitatory effects of glutamate in the PVN are tonically attenuated by NO. These data demonstrate that, in the PVN of conscious rats, GABA, glutamate and NO interact in a complex fashion to regulate arterial pressure and heart rate under normal conditions.

  7. Alpha particle emitters in cancer therapy: establishing the rationale and overcoming the difficulties

    International Nuclear Information System (INIS)

    Sgouros, G.

    1996-01-01

    Full text: Once a tumor has metastasized, the possibility of cure is significantly diminished, if not excluded. Since metastatic spread arises due to the release of single tumor cells or tumor cell clusters, treatment regimens following an overt metastasis must include agents that eradicate individual tumor cells and cell clusters or that prevent their dissemination. Alpha particles may be highly effective in eradicating rapidly accessible disease. The effectiveness of alpha particles arises because the amount of energy deposited per unit distance traveled (linear energy transfer or LET) is approximately 400 times greater than that of beta particles (80 keV/μm vs. 0.2 keV/μm). Each traversal of an alpha particle through a cell nucleus results in a very highly ionizing track. Cell survival studies have shown that alpha-particle killing is independent of oxygenation state or cell-cycle during irradiation and that as few as 1 to 6 tracks across the nucleus may result in cell death. Most studies with alpha-particle emitting radionuclides for therapy have examined either bismuth-212 or astatine-211. Both radionuclides are short-lived with 61 minute and 7.2 hour half-lives, respectively, yielding intermediates with 3-minute and 32 year half-lives, respectively. Both emit alpha particles whose range is 40 to 80 μm. Alpha-particle emitting radionuclides have been attached to antibodies against tumor cell associated antigen. Antibodies have been the most widely used vehicle for delivery of alpha particles due to their specificity. Bismuth-212 has demonstrated a significant curative potential with minimal toxicity. In an ascites tumor mouse model, specific targeting and 80% cure following injection of Bi-212-labeled antibody has been observed (Macklis RM et al, Science, 240:1024-1026, 1988). It is important to define the realm of applicability for alpha particle emitting radionuclides. The short half-life of most currently available radionuclides, limits their use to

  8. Tritiated-nicotine- and 125I-alpha-bungarotoxin-labeled nicotinic receptors in the interpeduncular nucleus of rats. II. Effects of habenular destruction

    International Nuclear Information System (INIS)

    Clarke, P.B.; Hamill, G.S.; Nadi, N.S.; Jacobowitz, D.M.; Pert, A.

    1986-01-01

    The cholinergic innervation of the interpeduncular nucleus (IPN) is wholly extrinsic and is greatly attenuated by bilateral habenular destruction. We describe changes in the labeling of putative nicotinic receptors within this nucleus at 3, 5, or 11 days after bilateral habenular lesions. Adjacent tissue sections of the rat IPN were utilized for 3 H-nicotine and 125 I-alpha-bungarotoxin ( 125 I-BTX) receptor autoradiography. Compared to sham-operated controls, habenular destruction significantly reduced autoradiographic 3 H-nicotine labeling in rostral (-25%), intermediate (-13%), and lateral subnuclei (-36%). Labeling in the central subnucleus was unchanged. Loss of labeling was maximal at the shortest survival time (3 days) and did not change thereafter. In order to establish whether this loss was due to a reduction in the number or the affinity of 3 H-nicotine-binding sites, a membrane assay was performed on microdissected IPN tissue from rats that had received surgery 3 days previously. Bilateral habenular lesions produced a 35% reduction of high-affinity 3 H-nicotine-binding sites, with no change in binding affinity. Bilateral habenular lesions reduced 125 I-BTX labeling in the intermediate subnuclei, and a slight increase occurred in the rostral subnucleus. In the lateral subnuclei, 125 I-BTX labeling was significantly reduced (27%) at 3 days but not at later survival times. In view of the known synaptic morphology of the habenulointerpeduncular tract, it is concluded that a subpopulation of 3 H-nicotine binding sites within the IPN is located on afferent axons and/or terminals. This subpopulation, located within rostral, intermediate, and lateral subnuclei, may correspond to presynaptic nicotinic cholinergic receptors. Sites that bind 125 I-BTX may include a presynaptic subpopulation located in the lateral and possibly the intermediate subnuclei

  9. A parton description of the nucleus fragmentation region in heavy-ion collisions

    International Nuclear Information System (INIS)

    Hwa, R.C.; Oregon Univ., Eugene

    1984-01-01

    In nucleus-nucleus collisions, the rapidity distribution of partons in the nucleus fragmentation region is highly asymmetrical. Thermalization that randomizes the momenta of partons far apart in rapidity cannot be expected. A local thermalization model is introduced which relates temperature to the range of parton interaction in rapidity. The parton number density and energy density are then calculated. (orig.)

  10. Approximate treatment of the deuteron+nucleus interaction in the resonating-group formulation

    International Nuclear Information System (INIS)

    Kaneko, T.

    1995-01-01

    A simplified version of the microscopic resonating-group method (RGM), called model K, is formulated for the deuteron+nucleus problem by making the simplifications of approximately treating the total center-of-mass motion and keeping only the direct and knockon-exchange terms. For these terms, the important point is that they can be analytically derived without much difficulty, with the consequence that the adoption of this model can enhance the general utility of the RGM by rendering the calculations feasible even in heavy nuclear systems. By utilizing the information obtained from previous investigations in the nucleon+nucleus case and by studying the analytical structure of the RGM kernel functions, it can be determined that this model for deuteron+nucleus scattering should work well when the nucleon-number ratio of the target and incident nuclei is larger than about 10 and when the scattering energy is higher than about 20 MeV/nucleon. A test comparison with exact RGM results for d+ 16 O scattering at 30 MeV and a fit to experiment for d+ 40 Ca scattering at 49.52 MeV yield rather convincing evidence that this model has great simplicity and generality, and can be employed to conduct a systematic and large-scale study of existing data on deuteron+nucleus scattering. (orig.)

  11. Dynamics of action potential initiation in the GABAergic thalamic reticular nucleus in vivo.

    Science.gov (United States)

    Muñoz, Fabián; Fuentealba, Pablo

    2012-01-01

    Understanding the neural mechanisms of action potential generation is critical to establish the way neural circuits generate and coordinate activity. Accordingly, we investigated the dynamics of action potential initiation in the GABAergic thalamic reticular nucleus (TRN) using in vivo intracellular recordings in cats in order to preserve anatomically-intact axo-dendritic distributions and naturally-occurring spatiotemporal patterns of synaptic activity in this structure that regulates the thalamic relay to neocortex. We found a wide operational range of voltage thresholds for action potentials, mostly due to intrinsic voltage-gated conductances and not synaptic activity driven by network oscillations. Varying levels of synchronous synaptic inputs produced fast rates of membrane potential depolarization preceding the action potential onset that were associated with lower thresholds and increased excitability, consistent with TRN neurons performing as coincidence detectors. On the other hand the presence of action potentials preceding any given spike was associated with more depolarized thresholds. The phase-plane trajectory of the action potential showed somato-dendritic propagation, but no obvious axon initial segment component, prominent in other neuronal classes and allegedly responsible for the high onset speed. Overall, our results suggest that TRN neurons could flexibly integrate synaptic inputs to discharge action potentials over wide voltage ranges, and perform as coincidence detectors and temporal integrators, supported by a dynamic action potential threshold.

  12. Production of neutrinos and neutrino-like particles in proton-nucleus interactions. [400 GeV, cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Dishaw, J.P.

    1979-03-01

    An experimental search was performed to look for the direct production of neutrinos or neutrino-like particles, i.e., neutral particles which interact weakly with hadrons, in proton-nucleus interactions at 400 GeV incident proton energy. Possible sources of such particles include the semi-leptonic decay of new heavy particles such as charm, and the direct production of a light neutral Higgs particle such as the axion. The production of these particles has been inferred in this experiment by energy nonconservation in the collision of a proton with an iron nucleus. The total visible energy of the interaction was measured using a sampling ionization calorimeter. After correcting for beam intensity effects and cutting the data to eliminate systematic effects in the measurement, the final resolution of the calorimeter was 3.51% and increased with decreasing incident beam energy with a square root dependence on the beam energy. Energy nonconservation in the data is manifest as a non-Gaussian distribution on the low side of the calorimeter measured energy. Model calculations yield the fraction of events expected in this non-Gaussian behavior for the various sources of neutrinos or neutrino-like particles. A maximum likelihood fit to the data with the theoretical fraction of events expected yields the 95% confidence level production cross section upper limit values. The upper limits for general production of neutrino-like particles for various parameterizations of the production cross section are presented. The following specific upper limits have been established: charm particle production < 670 ..mu..barns, supersymmetric particle production carrying an additional quantum number R < 33 ..mu..barns (mass of 1 GeV), 8 ..mu..barns (mass of 3 GeV); axion production < 10/sup -3/ times the ..pi../sup 0/ production cross section. 144 references.

  13. Parity violation in the compound nucleus

    International Nuclear Information System (INIS)

    Bowman, J.D.; Frankle, C.M.; Green, A.A.

    1994-01-01

    The status of parity violation in the compound nucleus is reviewed. The results of previous experimental results obtained by scattering polarized epithermal neutrons from heavy nuclei in the 3-p and 4-p p-wave strength function peaks are presented. Experimental techniques are presented. The extraction of the mean squared matrix element of the parity-violating interaction, M 2 , between compound-nuclear levels and the relationship of M 2 to the coupling strengths in the meson exchange weak nucleon-nucleon potential are discussed. The tendency of measured asymmetries to have a common sign and theoretical implications are discussed. New experimental results are presented that show that the common sign phenomenon is not universal, as theoretical models developed up to now would predict

  14. Polarization phenomena of nuclear force and weak interaction

    International Nuclear Information System (INIS)

    Konuma, Michitsugu

    1982-01-01

    As one of the projects at the National Laboratory of High Energy Physics (KEK), the measurement of parity non-conservation component in nuclear force was proposed. The theoretical survey of this proposal is reported. The non-relativistic parity non-conserving potential between nucleons can be obtained from the interaction between a quark and a gauge boson. The wave function of a nucleus, which includes the inverse components of the parity, can be written. A practical experiment was designed. The mixing of the inverse components and the interference of an inverse component in the 1042 keV and 1081 keV levels of F 18 may produce the parity non-conservation. The processes which suggest the existence of parity non-conservation were studied. The processes are the circular polarization of gamma-ray emitted from a nucleus, the angular distribution of gamma-ray emitted from polarized nuclei, the collision of the proton beam with helicity of plus and minus on other nuclei, the spin rotation of neutrons, and the alpha decay of the parity non-conservation. The preliminary results of the experiment on the effects of parity non-conservation in the collision process of polarized proton beam have been reported, and the theoretical analyses were performed. The violation of parity conservation in large momentum collision is discussed. The comparison of the theoretical results with the experimental ones is presented. (Kato, T.)

  15. Hepatitis B spliced protein (HBSP) promotes the carcinogenic effects of benzo [alpha] pyrene by interacting with microsomal epoxide hydrolase and enhancing its hydrolysis activity

    International Nuclear Information System (INIS)

    Chen, Jin-Yan; Chen, Wan-Nan; Jiao, Bo-Yan; Lin, Wan-Song; Wu, Yun-Li; Liu, Ling-Ling; Lin, Xu

    2014-01-01

    The risk of hepatocellular carcinoma (HCC) increases in chronic hepatitis B surface antigen (HBsAg) carriers who often have concomitant increase in the levels of benzo[alpha]pyrene-7,8-diol-9,10-epoxide(±) (BPDE)-DNA adduct in liver tissues, suggesting a possible co-carcinogenesis of Hepatitis B virus (HBV) and benzo[alpha]pyrene in HCC; however the exact mechanisms involved are unclear. The interaction between hepatitis B spliced protein (HBSP) and microsomal epoxide hydrolase (mEH) was confirmed using GST pull-down, co-immunoprecipitation and mammalian two-hybrid assay; the effects of HBSP on mEH-mediated B[alpha]P metabolism was examined by high performance liquid chromatography (HPLC); and the influences of HBSP on B[alpha]P carcinogenicity were evaluated by bromodeoxyuridine cell proliferation, anchorage-independent growth and tumor xenograft. HBSP could interact with mEH in vitro and in vivo, and this interaction was mediated by the N terminal 47 amino acid residues of HBSP. HBSP could greatly enhance the hydrolysis activity of mEH in cell-free mouse liver microsomes, thus accelerating the metabolism of benzo[alpha]pyrene to produce more ultimate carcinnogen, BPDE, and this effect of HBSP requires the intact HBSP molecule. Expression of HBSP significantly increased the formation of BPDE-DNA adduct in benzo[alpha]pyrene-treated Huh-7 hepatoma cells, and this enhancement was blocked by knockdown of mEH. HBSP could enhance the cell proliferation, accelerate the G1/S transition, and promote cell transformation and tumorigenesis of B[alpha]P-treated Huh-7 hepatoma cells. Our results demonstrated that HBSP could promote carcinogenic effects of B[alpha]P by interacting with mEH and enhancing its hydrolysis activity

  16. Nature of multiplicity correlations in 12C-nucleus reaction at 4.5 AGeV

    International Nuclear Information System (INIS)

    Saleem Khan, M.; Shukla, Praveen Prakash; Khushnood, H.

    2011-01-01

    Multiplicity correlations in high energy hadron-nucleus and nucleus-nucleus interactions are considered one of the most important parameter to study the dynamics of particles production. In the present work, an attempt has been made to understand the nature of the multiplicity correlations

  17. Total disintegration of the carbon nucleus by 40 GeV/c π- mesons

    International Nuclear Information System (INIS)

    Angelov, N.; Lyubimov, V.B.; Solov'ev, M.I.; Tuvendorzh, D.; Anoshin, A.I.; Sulejmanov, M.

    1978-01-01

    Studied is the phenomenon of a complete disintegration (CD) of a nucleus in the π -12 C interactions at the π - momentum equal to 40 GeV/c. The experiments were carried out in a 2-meter propane chamber. Momenta and emission angles of all charged particles were measured. The D probability for a carbon nucleus turned out to be equal to (7.0+-0.3)%. No difference was observed between the events of CD and the ''usual'' π -12 C interaction based on the consideration of angular and momentum distributions of π +- mesons and protons. The leading effect in the events with the target-nucleus CD is weaker than in all the rest π -12 C interactions

  18. A redefinition of the energy ansata, leading to a fundamentally new class of nuclear interactions

    International Nuclear Information System (INIS)

    Bearden, T.E.

    1992-01-01

    Utilizing fundamental new definitions for energy, potential, and scalar potential, the mass of the atomic nucleus may be considered a powerful electrostatic scalar potential, referred to as the mass potential. The Whittaker EM biwave structure of the scalar potential then becomes a new and universal internal EM structure for mass, including the atomic nucleus. This structure can be directly manipulated electromagnetically, which allows direct EM alteration of the mass potential , and the nucleus itself. This totally new class of nuclear interactions is briefly explored in this paper, and several hypothesized mechanisms advanced for neutralizing or processing nuclear wastes. Additional applications are hypothesized for experimental falsification or verification

  19. Structure and interactions of calcite spherulites with {alpha}-chitin in the brown shrimp (Penaeus aztecus) shell

    Energy Technology Data Exchange (ETDEWEB)

    Heredia, A. [Instituto de Ciencias Nucleares, Departamento de Quimica de Radiaciones y Radioquimica, UNAM, Circuito Exterior C.U. Apdo., Postal 70-543, 04510 Mexico, D.F. (Mexico); Physikalisches Institut and Center for Nanotechnology, Universitaet Muenster, Gievenbecker Weg 11, 48149 Muenster (Germany); Aguilar-Franco, M. [Instituto de Fisica, Depto de Fisicoquimica, UNAM, Circuito Exterior s/n, Ciudad Universitaria Apartado Postal 20-364 01000 Mexico D.F. (Mexico); Magana, C. [Instituto de Fisica, Depto de Estado Solido, UNAM, Circuito Exterior s/n, Ciudad Universitaria Apartado Postal 20-364 01000 Mexico D.F. (Mexico); Flores, C. [Instituto de Investigaciones en Materiales, Depto de Estado Solido, Laboratorio de Biomateriales, UNAM, Circuito Exterior C.U. S/N CP 04510 Mexico, D.F. (Mexico); Pina, C. [Instituto de Investigaciones en Materiales, Depto de Estado Solido, Laboratorio de Biomateriales, UNAM, Circuito Exterior C.U. S/N CP 04510 Mexico, D.F. (Mexico); Velazquez, R. [Centro de Fisica Aplicada Tecnologia Avanzada, UNAM, Km. 15 Carretera Queretaro-San Luis Potosi, C.P. 76230, Queretaro, Qro. (Mexico); Schaeffer, T.E. [Physikalisches Institut and Center for Nanotechnology, Universitaet Muenster, Gievenbecker Weg 11, 48149 Muenster (Germany); Bucio, L. [Instituto de Fisica, Depto de Estado Solido, UNAM, Circuito Exterior s/n, Ciudad Universitaria Apartado Postal 20-364 01000 Mexico D.F. (Mexico); Basiuk, V.A. [Instituto de Ciencias Nucleares, Departamento de Quimica de Radiaciones y Radioquimica, UNAM, Circuito Exterior C.U. Apdo., Postal 70-543, 04510 Mexico, D.F. (Mexico)

    2007-01-15

    White spots form in the brown shrimp (Penaeus aztecus, Decapoda) shell during frozen storage. The mineral formed consists of calcite incorporated into an amorphous {alpha}-chitin matrix. We studied mechanisms of interaction of amorphous {alpha}-chitin macromolecules with hkl crystal planes to form highly ordered structures, as well as the role of specific sites in the biopolymer, which can be related to nucleation and spheroidal crystal growth. We used low vacuum scanning electron microscopy (LVSEM), X-ray powder diffraction (XRD), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), and molecular mechanics modeling (MM+ method). AFM images showed fingerprint distances in the biopolymer and a highly layered structure in the crystalline material. The presence of {alpha}-chitin, with a specific spatial distribution of radicals, is thought to be responsible for nucleation and to thermodynamically stabilize ions to form the spherulite crystalline phase, which are usually oval to spherical (0.10 to 200 {mu}m in diameter). Our models of crystal-biopolymer interaction found high affinity of CO{sub 3} {sup 2-} anions in the (104) crystalline plane (the main plane in calcite monocrystals) to NH- groups of the biopolymer, as well as of the C=O in the biopolymer to Ca{sup 2+} cations in the crystalline structure. These interactions explain the spherical growth and inhibition in some planes. The specific physicochemical interactions (docking of groups depending on their geometrical distribution) suggest that the biomineral structure is controlled by the biopolymer on a local scale. This information is useful for further design and improvement of (hybrid) materials for versatile application, from nanotechnology to biomedicine and engineering.

  20. Deconfinement of quarks and gluons in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Gorenstein, M.I.

    2011-01-01

    The energy dependence of hadron production in relativistic nucleus-nucleus collisions reveals the anomalies. They were predicted as the signals of the deconfinement phase transition and observed by NA49 collaboration in Pb+Pb collisions at the CERN SPS. This indicates the onset of the deconfinement in central nucleus-nucleus collisions at about 30 AGeV.

  1. Mirrors in the PDB: left-handed alpha-turns guide design with D-amino acids.

    Science.gov (United States)

    Annavarapu, Srinivas; Nanda, Vikas

    2009-09-22

    Incorporating variable amino acid stereochemistry in molecular design has the potential to improve existing protein stability and create new topologies inaccessible to homochiral molecules. The Protein Data Bank has been a reliable, rich source of information on molecular interactions and their role in protein stability and structure. D-amino acids rarely occur naturally, making it difficult to infer general rules for how they would be tolerated in proteins through an analysis of existing protein structures. However, protein elements containing short left-handed turns and helices turn out to contain useful information. Molecular mechanisms used in proteins to stabilize left-handed elements by L-amino acids are structurally enantiomeric to potential synthetic strategies for stabilizing right-handed elements with D-amino acids. Propensities for amino acids to occur in contiguous alpha(L) helices correlate with published thermodynamic scales for incorporation of D-amino acids into alpha(R) helices. Two backbone rules for terminating a left-handed helix are found: an alpha(R) conformation is disfavored at the amino terminus, and a beta(R) conformation is disfavored at the carboxy terminus. Helix capping sidechain-backbone interactions are found which are unique to alpha(L) helices including an elevated propensity for L-Asn, and L-Thr at the amino terminus and L-Gln, L-Thr and L-Ser at the carboxy terminus. By examining left-handed alpha-turns containing L-amino acids, new interaction motifs for incorporating D-amino acids into right-handed alpha-helices are identified. These will provide a basis for de novo design of novel heterochiral protein folds.

  2. Analysis and Quantitation of NF-[kappa]B Nuclear Translocation in Tumor Necrosis Factor Alpha (TNF-[alpha]) Activated Vascular Endothelial Cells

    Science.gov (United States)

    Fuseler, John W.; Merrill, Dana M.; Rogers, Jennifer A.; Grisham, Matthew B.; Wolf, Robert E.

    2006-07-01

    Nuclear factor kappa B (NF-[kappa]B) is a heterodimeric transcription factor typically composed of p50 and p65 subunits and is a pleiotropic regulator of various inflammatory and immune responses. In quiescent cells, p50/p65 dimers are sequestered in the cytoplasm bound to its inhibitors, the I-[kappa]Bs, which prevent entry into the nucleus. Following cellular stimulation, the I-[kappa]Bs are rapidly degraded, activating NF-[kappa]B. The active form of NF-[kappa]B rapidly translocates into the nucleus, binding to consensus sequences in the promoter/enhancer region of various genes, promoting their transcription. In human vascular endothelial cells activated with tumor necrosis factor-alpha, the activation and translocation of NF-[kappa]B is rapid, reaching maximal nuclear localization by 30 min. In this study, the appearance of NF-[kappa]B (p65 subunit, p65-NF-[kappa]B) in the nucleus visualized by immunofluorescence and quantified by morphometric image analysis (integrated optical density, IOD) is compared to the appearance of activated p65-NF-[kappa]B protein in the nucleus determined biochemically. The appearance of p65-NF-[kappa]B in the nucleus measured by fluorescence image analysis and biochemically express a linear correlation (R2 = 0.9477). These data suggest that localization and relative protein concentrations of NF-[kappa]B can be reliably determined from IOD measurements of the immunofluorescent labeled protein.

  3. Multiplicity of secondaries in hadron-nucleus collisions and constituent quark rescattering

    International Nuclear Information System (INIS)

    Shabelsky, Yu.M.; Shekhter, V.M.

    1980-01-01

    A ratio of the relativistic secondary multiplicities for hadron-nucleus and hadron-nucleon interactions, Rsub(s)(hA), is considered in the central region and a part of the target nucleus fragmentation region. The multiplicities are obtained from the experimental average numbers of relativistic charged or negative particles by subtraction of the projectile fragment numbers estimated theoretically. Two hypotheses on the A dependence of the secondary multiplicity in a constituent quark interaction with a nucleus are discussed. An assumption that this multiplicity is independent of A leads to Rsub(s)(hA) = antiνsub(hA)/antiνsub(qA). An alternative assumption that the qA multiplicity increases with A due to quark rescattering from several nucleons gives Rsub(s)(hA) = antiνsub(hA). Comparison with experiment in the former case requires a great number of positively charged hadrons, probably protons, emitted from the nucleus. This number must rise significantly with both A and incident energy. The latter hypothesis is consistent with all data on as well as in pA collisions but disagrees by approximately 20% with in π - A interactions. (author)

  4. Alpha particle spectra in coincidence with normal and superdeformed states in {sup 150}Tb

    Energy Technology Data Exchange (ETDEWEB)

    Viesti, G.; Lunardon, M.; Bazzacco, D. [dell`Universita, Padova (Italy)]|[INFN, Padova (Italy)] [and others

    1996-12-31

    The study of correlations between particle evaporation from highly excited compound nuclei at large angular momenta and the states in the final evaporation residues (ER) is a field of investigation which has been opened, in the last years, with the advent of the new large {gamma}-ray arrays. It is now possible to correlate the evaporation spectra to various bands with shapes ranging from spherical to superdeformed (SD) in the same final nucleus. It is generally accepted that the particle evaporation from the compound nucleus is chaotic and that only in the near-yrast {gamma} cascade, where the feeding of different classes of states takes place, the ordered motion is restored. The sensitivity of the particle spectra on the feeding of specific states in the residual nuclei can be taken as an indication that additional degrees of freedom might be important in the evaporation process or that particular regions of the phase space open to the decay populate preferentially some selected structures in the final cold nucleus. This latter point is important for the understanding of the feeding mechanism of SD states. Several experiments performed so far did not find a clear dependence of the shapes of the particle spectra on the excited states having different deformations in the ER. For example, the proton spectra in coincidence with transitions in the SD bands of {sup 133}Nd and {sup 152}Dy nuclei were found to be similar to those in coincidence with transitions in the normal deformed (ND) bands. Alpha particles have been proposed since long as a sensitive probe of the deformation of the emitting nucleus. Results are presented here of an experiment in which the authors have measured the energy spectra of alpha particles associated with different classes of states (ND and SD) in the {sup 150}Tb nucleus populated in the reaction {sup 37}Cl({sup 120}Sn, {alpha}3n{gamma}){sup 150}Tb.

  5. Experimental studies of nucleon-nucleon and pion-nucleus interactions at intermediate energies: Annual progress report, 1988--1989

    International Nuclear Information System (INIS)

    1988-01-01

    This report summarizes the work on experimental research in intermediate energy nuclear and particle physics carried out by New Mexico State University in 1988 under a grant from the US Department of Energy. The nucleon-nucleon research has involved studies of interactions between polarized neutrons and polarized protons. Its purpose is to help complete the determination of the nucleon-nucleon amplitudes at energies up to 800 MeV, as part of a program currently in progress at LAMPF, as well as to investigate the possibility of the existence of dibaryon resonances. The pion-nucleus research involves studies of this interaction in regions where it has not been adequately explored. These include experiments on elastic and double charge exchange scattering at energies above the /Delta/(1232) resonance, interactions with polarized nuclear targets, and investigations of pion absorption using a detector covering nearly the full solid angle region. 21 refs., 4 figs

  6. Calcitonin gene-related peptide erases the fear memory and facilitates long-term potentiation in the central nucleus of the amygdala in rats.

    Science.gov (United States)

    Wu, Xin; Zhang, Jie-Ting; Liu, Jue; Yang, Si; Chen, Tao; Chen, Jian-Guo; Wang, Fang

    2015-11-01

    Calcitonin gene-related peptide (CGRP) is a 37 amino acid neuropeptide, which plays a critical role in the central nervous system. CGRP binds to G protein-coupled receptors, including CGRP1, which couples positively to adenylyl cyclase (AC) and protein kinase A (PKA) activation. CGRP and CGRP1 receptors are enriched in central nucleus of the amygdala (CeA), the main part of the amygdala, which regulates conditioned fear memories. Here, we reported the importance of CGRP and CGRP1 receptor for synaptic plasticity in the CeA and the extinction of fear memory in rats. Our electrophysiological and behavioral in vitro and in vivo results showed exogenous application of CGRP induced an immediate and lasting long-term potentiation in the basolateral nucleus of amygdala-CeA pathway, but not in the lateral nucleus of amygdala-CeA pathway, while bilateral intra-CeA infusion CGRP (0, 5, 13 and 21 μM/side) dose dependently enhanced fear memory extinction. The effects were blocked by CGRP1 receptor antagonist (CGRP8-37 ), N-methyl-d-aspartate receptors antagonist MK801 and PKA inhibitor H89. These results demonstrate that CGRP can lead to long-term potentiation of basolateral nucleus of amygdala-CeA pathway through a PKA-dependent postsynaptic mechanism that involved N-methyl-d-aspartate receptors and enhance the extinction of fear memory in rats. Together, the results strongly support a pivotal role of CGRP in the synaptic plasticity of CeA and extinction of fear memory. Calcitonin gene-related peptide (CGRP) plays an essential role in synaptic plasticity in the amygdala and fear memory. We found that CGRP-induced chemical long-term potentiation (LTP) in a dose-dependent way in the BLA-CeA (basolateral and central nucleus of amygdala, respectively) pathway and enhanced fear memory extinction in rats through a protein kinase A (PKA)-dependent postsynaptic mechanism that involved NMDA receptors. These results support a pivotal role of CGRP in amygdala. © 2015 International

  7. Low glutathione regulates gene expression and the redox potentials of the nucleus and cytosol in Arabidopsis thaliana.

    Science.gov (United States)

    Schnaubelt, Daniel; Queval, Guillaume; Dong, Yingping; Diaz-Vivancos, Pedro; Makgopa, Matome Eugene; Howell, Gareth; De Simone, Ambra; Bai, Juan; Hannah, Matthew A; Foyer, Christine H

    2015-02-01

    Reduced glutathione (GSH) is considered to exert a strong influence on cellular redox homeostasis and to regulate gene expression, but these processes remain poorly characterized. Severe GSH depletion specifically inhibited root meristem development, while low root GSH levels decreased lateral root densities. The redox potential of the nucleus and cytosol of Arabidopsis thaliana roots determined using roGFP probes was between -300 and -320 mV. Growth in the presence of the GSH-synthesis inhibitor buthionine sulfoximine (BSO) increased the nuclear and cytosolic redox potentials to approximately -260 mV. GSH-responsive genes including transcription factors (SPATULA, MYB15, MYB75), proteins involved in cell division, redox regulation (glutaredoxinS17, thioredoxins, ACHT5 and TH8) and auxin signalling (HECATE), were identified in the GSH-deficient root meristemless 1-1 (rml1-1) mutant, and in other GSH-synthesis mutants (rax1-1, cad2-1, pad2-1) as well as in the wild type following the addition of BSO. Inhibition of auxin transport had no effect on organ GSH levels, but exogenous auxin decreased the root GSH pool. We conclude that GSH depletion significantly increases the redox potentials of the nucleus and cytosol, and causes arrest of the cell cycle in roots but not shoots, with accompanying transcript changes linked to altered hormone responses, but not oxidative stress. © 2013 John Wiley & Sons Ltd.

  8. Optical potentials and isoscalar transition rates from 104 MeV alpha-particle scattering by the N=28 isotopes 48Ca, 50Ti and 52Cr

    International Nuclear Information System (INIS)

    Friedman, E.; Pesl, R.; Gils, H.J.; Rebel, H.; Buschmann, J.; Klewe-Nebenius, H.; Zagromski, S.

    1983-02-01

    Precisely measured differential cross sections for elastic and inelastic scattering from 104 MeV alpha-particles by 48 Ca, 50 Ti and 52 Cr are reported. The analyses aim primarily at the determination of strength, radial shapes and deformation of the scattering potentials, looking for isotonic differences of N = 28 isotones. The mean square radii of the (real) potentials are discussed in terms of mean square radius differences of the matter distributions. The isoscalar transition rates derived by coupled channel analyses of the measured cross sections are compared with electromagnetic rates. In addition to the analyses on the basis of a slightly generalized extended optical model a semi-microscopic deformed folding model has been applied, using a density-dependent effective alpha-bound nucleon interaction. Though an excellent description of the data over the full angular range is obtained the resulting values of the deformation parameters appear to be not consistent with results from various different methods. (orig.) [de

  9. Wandering in the Lyman-alpha forest: a study of dark matter-dark radiation interactions

    International Nuclear Information System (INIS)

    Krall, Rebecca; Cyr-Racine, Francis-Yan; Dvorkin, Cora

    2017-01-01

    The amplitude of large-scale matter fluctuations inferred from the observed Sunyaev-Zeldovich (SZ) cluster mass function and from weak gravitational lensing studies, when taken at face value, is in tension with measurements of the cosmic microwave background (CMB) and baryon acoustic oscillation (BAO). In this work, we revisit whether this possible discrepancy can be attributed to new interactions in the dark matter sector. Focusing on a cosmological model where dark matter interacts with a dark radiation species until the epoch of matter-radiation equality, we find that measurements of the Lyman-alpha flux power spectrum from the Sloan Digital Sky Survey provide no support to the hypothesis that new dark matter interactions can resolve the possible tension between CMB and large-scale structure (LSS). Indeed, while the addition of dark matter-dark radiation interactions leads to an improvement of 2ΔlnL=12 with respect to the standard Λ cold dark matter (ΛCDM) model when only CMB, BAO, and LSS data are considered, the inclusion of Lyman-alpha data reduces the improvement of the fit to 2ΔlnL=6 relative to ΛCDM . We thus conclude that the statistical evidence for new dark matter interactions (largely driven by the Planck SZ dataset) is marginal at best, and likely caused by systematics in the data. We also perform a Fisher forecast analysis for the reach of a future dataset composed of a CMB-S4 experiment combined with the Large Synoptic Survey Telescope galaxy survey. We find that the constraint on the effective number of fluid-like dark radiation species, Δ N fluid , will be improved by an order of magnitude compared to current bounds.

  10. Charged pion coherent production in nucleus-nucleus collisions at incident energies between 86 and 330 MeV/nucleon

    International Nuclear Information System (INIS)

    Fassnacht, P.

    1984-01-01

    We have studied pion production in nucleus-nucleus collisions at foward angles for about twenty projectile target combinations. The incident energies were below or around 300 MeV/nucleon which is the threshold of the elementary reaction NN → NNπ. The study of the inclusive spectra shows some new ideas: shell effects in pion production, collective resonances excitations. These spectra have been analyzed following different models: hard-scattering models which describe the interaction on the basis of the elementary reaction NN → NNπ, statistical model and the pionic cloud model which is a coherent description of the interaction. In the study of the exclusive reactions, we established some empiric rules concerning the cross-section variations. These exclusive spectra were then analyzed in the framework of two-models: the semi-phenomenological model and the pionic fusion [fr

  11. WITNESSING THE KEY EARLY PHASE OF QUASAR EVOLUTION: AN OBSCURED ACTIVE GALACTIC NUCLEUS PAIR IN THE INTERACTING GALAXY IRAS 20210+1121

    International Nuclear Information System (INIS)

    Piconcelli, Enrico; Fiore, Fabrizio; Maiolino, Roberto; Nicastro, Fabrizio; Vignali, Cristian; Bianchi, Stefano; Mathur, Smita; Guainazzi, Matteo; Lanzuisi, Giorgio

    2010-01-01

    We report the discovery of an active galactic nucleus (AGN) pair in the interacting galaxy system IRAS 20210+1121 at z = 0.056. An XMM-Newton observation reveals the presence of an obscured (N H ∼ 5 x 10 23 cm -2 ), Seyfert-like (L 2-10keV = 4.7 x 10 42 erg s -1 ) nucleus in the northern galaxy, which lacks unambiguous optical AGN signatures. Our spectral analysis also provides strong evidence that the IR-luminous southern galaxy hosts a Type 2 quasar embedded in a bright starburst emission. In particular, the X-ray primary continuum from the nucleus appears totally depressed in the XMM-Newton band as expected in the case of a Compton-thick absorber, and only the emission produced by Compton scattering ('reflection') of the continuum from circumnuclear matter is seen. As such, IRAS 20210+1121 seems to provide an excellent opportunity to witness a key, early phase in the quasar evolution predicted by the theoretical models of quasar activation by galaxy collisions.

  12. Neutrino-nucleus cross section in the impulse approximation regime

    International Nuclear Information System (INIS)

    Benhar, Omar; Farina, Nicola

    2005-01-01

    In the impulse approximation regime the nuclear response to a weakly interacting probe can be written in terms of the measured nucleon structure functions and the target spectral function, yielding the energy and momentum distribution of the constituent nucleons. We discuss a calculation of charged current neutrino-oxygen interactions in the quasielastic channel, carried out within nuclear many body theory. The proposed approach, extensively and successfully employed in the analysis of electron-nucleus scattering data, allows for a parameter free prediction of the neutrino-nucleus cross section, whose quantitative understanding will be critical to the analysis of the next generation of high precision neutrino oscillation experiments

  13. A new barrier potential and alpha-decay half-lives of even–even nuclei in the 82⩽Z⩽92 regime

    Energy Technology Data Exchange (ETDEWEB)

    Hassanabadi, Hasan [Physics Department, Shahrood University of Technology, Shahrood (Iran, Islamic Republic of); Javadimanesh, ELham, E-mail: elham_javadimanesh89@yahoo.com [Department of Basic Sciences, Shahrood Branch, Islamic Azad University, Shahrood (Iran, Islamic Republic of); Zarrinkamar, Saber [Department of Basic Sciences, Garmsar Branch, Islamic Azad University, Garmsar (Iran, Islamic Republic of)

    2013-05-15

    The alpha-decay half-life in a nuclear reaction is mainly affected by the penetration probability, which itself depends on the choice of the barrier potential. Here, we propose a new barrier potential to investigate the alpha-decay half-lives in the even–even nuclei from {sup 178}Po to {sup 238}U. The obtained results are motivating.

  14. Mechanism of energy release from nucleus-target in hadron-nucleus collision

    International Nuclear Information System (INIS)

    Strugalski, Z.; Strugalska-Gola, E.

    2000-01-01

    The collisions of hadrons (protons, mesons) with 131 Xe nucleus and arising light nuclear fragments as nuclear refraction products have been observed in bubble chamber. Mechanism of energy release during these collisions has been discussed. The quantitative calculations has proved that this phenomena can be treated as potential energy source with use of many different target materials

  15. The Spectator-Induced Electromagnetic Effect on Meson Production in Nucleus-Nucleus Collisions at SPS Energies

    Directory of Open Access Journals (Sweden)

    Rybicki Andrzej

    2012-12-01

    Full Text Available The electromagnetic interaction between the spectator system and the charged mesons produced in the course of the high energy heavy ion collision was studied experimentally and theoretically in earlier works [1,2]. This effect was found to result in very large distortions of the final state spectra of the produced mesons [3] and to bring new information on the space-time evolution of the non-perturbative meson production process [4]. In this paper a more extended analysis of this effect will be presented, including a comparative study between charged meson spectra produced in Pb+Pb collisions as well as collisions of Pb ions with smaller nuclei. The experimental results will be compared with Monte Carlo simulations, giving a fair overall understanding of the interplay between the strong and the electromagnetic interaction in the heavy ion collision. A universal behaviour of charged meson spectra emerges from the above comparative study. This gives a unique chance of using the spectator charge as a tool to study the space-time evolution of the high energy nucleus-nucleus reaction.

  16. Choice of the density-dependent effective interaction and alpha decay of heavy spherical nuclei

    International Nuclear Information System (INIS)

    Kadmenskij, S.G.; Ratis, Yu.L.; Rybak, K.S.; Furman, V.I.

    1978-01-01

    The parameters of density-dependent effective interaction are studied for some nuclei in the vicinity of a 208 Pb double-magic nucleus. Both nuclei having two nucleons (holes) over magic core and some superfluid nuclei are considered. It is found that the magnitudes of the matrix elements for the zero-range forces (delta forces) are more than three times larger in comparison with the case of the finite-range forces (f forces). Sets of parameters for the effective interaction, which does not lead to the superfluidity of nuclear matter are obtained. Besides, these parameters depend weakly on mass number. It is shown that the attractive part of interaction is substantially larger for the case of f forces than for the delta forces. The theoretical enhancement coefficients for the favoured α decay of 210 Po, 210 Pb and 224 Th nuclei are calculated. For the case of f forces a tendency to saturation of the enhancement coefficients with the increase of the shell-model basis is found

  17. Multiparticle excitations in the {sup 149} Gd superdeformed nucleus. Signature of new C{sub 4} nucleus symmetry; Excitations multiparticules dans le noyau superdeforme {sup 149}Gd. Signature d`une symetrie nouvelle C{sub 4} du noyau

    Energy Technology Data Exchange (ETDEWEB)

    Theisen, C

    1995-01-01

    The use of 8 {pi} and EUROGAM phase I multi-detectors for the study of high spin states of {sup 149} Gd nucleus has revealed unexpected new phenomenons about the superdeformation in this nucleus. The new excited bands confirm the omnipresence of twin bands phenomenon. A new multi-particle excitation (two protons and one neutron) has been discovered. Thanks to the second generation EUROGAM detector, unexpected discoveries such as C{sub 4} symmetry, level interactions, complete backbending were obtained for the second potential well. The knowledge of interacting levels gives informations about the nucleon-nucleon residual interaction and could allow the determination of SD bands excitation energy. The complex processing and analysis of high multiplicity events has led to the development of new computing tools. An automatic band research program has been written for the discovery of new excited bands, and an exact method for the elimination of uncorrected events has been developed. The improvements of multi-detector performances should allow the discovery of more exceptional phenomenons and new anomalies in the SD bands. (J.S.). 222 refs., 86 figs., 38 tabs.

  18. Exosomes as potential alternatives to stem cell therapy for intervertebral disc degeneration: in-vitro study on exosomes in interaction of nucleus pulposus cells and bone marrow mesenchymal stem cells.

    Science.gov (United States)

    Lu, Kang; Li, Hai-Yin; Yang, Kuang; Wu, Jun-Long; Cai, Xiao-Wei; Zhou, Yue; Li, Chang-Qing

    2017-05-10

    The stem cell-based therapies for intervertebral disc degeneration have been widely studied. However, the mechanisms of mesenchymal stem cells interacting with intervertebral disc cells, such as nucleus pulposus cells (NPCs), remain unknown. Exosomes as a vital paracrine mechanism in cell-cell communication have been highly focused on. The purpose of this study was to detect the role of exosomes derived from bone marrow mesenchymal stem cells (BM-MSCs) and NPCs in their interaction with corresponding cells. The exosomes secreted by BM-MSCs and NPCs were purified by differential centrifugation and identified by transmission electron microscope and immunoblot analysis of exosomal marker proteins. Fluorescence confocal microscopy was used to examine the uptake of exosomes by recipient cells. The effects of NPC exosomes on the migration and differentiation of BM-MSCs were determined by transwell migration assays and quantitative RT-PCR analysis of NPC phenotypic genes. Western blot analysis was performed to examine proteins such as aggrecan, sox-9, collagen II and hif-1α in the induced BM-MSCs. Proliferation and the gene expression profile of NPCs induced by BM-MSC exosomes were measured by Cell Counting Kit-8 and qRT-PCR analysis, respectively. Both the NPCs and BM-MSCs secreted exosomes, and these exosomes underwent uptake by the corresponding cells. NPC-derived exosomes promoted BM-MSC migration and induced BM-MSC differentiation to a nucleus pulposus-like phenotype. BM-MSC-derived exosomes promoted NPC proliferation and healthier extracellular matrix production in the degenerate NPCs. Our study indicates that the exosomes act as an important vehicle in information exchange between BM-MSCs and NPCs. Given a variety of functions and multiple advantages, exosomes alone or loaded with specific genes and drugs would be an appropriate option in a cell-free therapy strategy for intervertebral disc degeneration.

  19. Improving the Calculation of The Potential Between Spherical and Deformed Nuclei

    International Nuclear Information System (INIS)

    Ismail, M.; Ramadan, Kh.A.

    2000-01-01

    The Heavy Ion (HI) interaction potential between spherical and deformed nuclei is improved by calculating its exchange part using finite range nucleon-nucleon (NN) force. We considered U 238 as a target nucleus and seven projectile nuclei to show the dependence of the HI potential on both the energy and orientation of the deformed target nucleus. The effect of finite range NN force has been found to produce significant changes in the HI potential. The variation of the barrier height V B , its thickness and its position R B due to the use of finite range NN force are significant. Such variation enhance the fusion cross-section at energy values just below the Coulomb barrier by a factor increasing with the mass number of projectile nucleus. (author)

  20. Relativistic electron beam interaction and $K_{\\alpha}$-generation in solid targets

    CERN Document Server

    Fill, E; Eder, D; Eidmann, K; Saemann, A

    1999-01-01

    When fs laser pulses interact with solid surfaces at intensities I lambda /sup 2/ >10/sup 18/ W/cm/sup 2/ mu m/sup 2/, collimated relativistic electron beams are generated. These electrons can be used for producing intense X-radiation (bremsstrahlung or K/sub alpha /) for pumping an innershell X-ray laser. The basic concept of such a laser involves the propagation of the electron beam in a material which converts electron energy into appropriate pump photons. Using the ATLAS titanium-sapphire laser at Max-Planck-Institut fur Quantenoptik, we investigate the generation of hot electrons and of characteristic radiation in copper. The laser (200 mJ/130 fs) is focused by means of an off-axis parabola to a diameter of about 10 mu m. By varying the position of the focus, we measure the copper K/sub alpha /-yield as a function of intensity in a range from 10/sup 15/ to 2 x 10/sup 18/ W/cm/sup 2/ while keeping the laser pulse energy constant. Surprisingly, the highest emission is obtained at an intensity of about 10/s...

  1. Distinct Contributions of Median Raphe Nucleus to Contextual Fear Conditioning and Fear-Potentiated Startle

    Science.gov (United States)

    Silva, R. C. B.; Cruz, A. P. M.; Avanzi, V.; Landeira-Fernandez, J.; Brandão, M. L.

    2002-01-01

    Ascending 5-HT projections from the median raphe nucleus (MRN), probably to the hippocampus, are implicated in the acquisition of contextual fear (background stimuli), as assessed by freezing behavior. Foreground cues like light, used as a conditioned stimulus (CS) in classical fear conditioning, also cause freezing through thalamic transmission to the amygdala. As the MRN projects to the hippocampus and amygdala, the role of this raphe nucleus in fear conditioning to explicit cues remains to be explained. Here we analyzed the behavior of rats with MRN electrolytic lesions in a contextual conditioning situation and in a fear-potentiated startle procedure. The animals received MRN electrolytic lesions either before or on the day after two consecutive training sessions in which they were submitted to 10 conditioning trials, each in an experimental chamber (same context) where they. received foot-shocks (0.6 mA, 1 sec) paired to a 4-sec light CS. Seven to ten days later, the animals were submitted to testing sessions for assessing conditioned fear when they were placed for five shocks, and the duration of contextual freezing was recorded. The animals were then submitted to a fear-potentiated startle in response to a 4-sec light-CS, followed by white noise (100 dB, 50 ms). Control rats (sham) tested in the same context showed more freezing than did rats with pre- or post-training MRN lesions. Startle was clearly potentiated in the presence of light CS in the sham-lesioned animals. Whereas pretraining lesions reduced both freezing and fear-potentiated startle, the post-training lesions reduced only freezing to context, without changing the fear-potentiated startle. In a second experiment, neurotoxic lesions of the MRN with local injections of N-methyl-D-aspartate or the activation of 5-HT1A somatodendritic auto-receptors of the MRN by microinjections of the 5-HT1A receptor agonist 8-hydroxy- 2-(di-n-propylamino)tetralin (8-OH-DPAT) before the training sessions also

  2. Novel drugs that target the estrogen-related receptor alpha: their therapeutic potential in breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    May, Felicity EB, E-mail: F.E.B.May@ncl.ac.uk [Northern Institute for Cancer Research and Department of Pathology, Faculty of Medical Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne (United Kingdom)

    2014-05-23

    The incidence of breast cancer continues to rise: 1.7 million women were diagnosed with and 521,000 women died from breast cancer in 2012. This review considers first current treatment options: surgery; radiotherapy; and systemic endocrine, anti-biological, and cytotoxic therapies. Clinical management includes prevention, early detection by screening, treatment with curative intent, management of chronic disease, and palliative control of advanced breast cancer. Next, the potential of novel drugs that target DNA repair, growth factor dependence, intracellular and intercellular signal transduction, and cell cycle are considered. Estrogen-related receptor alpha has attracted attention as a therapeutic target in triple-negative breast cancers with de novo resistance to, and in breast cancers with acquired resistance to, endocrine therapies such as antiestrogens and aromatase inhibitors. Estrogen-related receptor alpha is an orphan receptor and transcription factor. Its activity is regulated by coregulator proteins and posttranslational modification. It is an energy sensor that controls adaptation to energy demand and may facilitate glycolytic metabolism and mitochondrial oxidative respiration in breast cancer cells. Estrogen-related receptor alpha increases breast cancer cell migration, proliferation, and tumor development. It is expressed at high levels in estrogen receptor-negative tumors, and is proposed to activate estrogen-responsive genes in endocrine-resistant tumors. The structures and functions of the ligand-binding domains of estrogen receptor alpha and estrogen-related receptor alpha, their ability to bind estrogens, phytoestrogens, and synthetic ligands, and the effects of ligand agonists, antagonists, and inverse agonists on biological activity, are evaluated. Synthetic ligands of estrogen-related receptor alpha have activity in preclinical models of metabolic disorders, diabetes, osteoporosis, and oncology. The clinical settings in which these novel

  3. Novel drugs that target the estrogen-related receptor alpha: their therapeutic potential in breast cancer

    International Nuclear Information System (INIS)

    May, Felicity EB

    2014-01-01

    The incidence of breast cancer continues to rise: 1.7 million women were diagnosed with and 521,000 women died from breast cancer in 2012. This review considers first current treatment options: surgery; radiotherapy; and systemic endocrine, anti-biological, and cytotoxic therapies. Clinical management includes prevention, early detection by screening, treatment with curative intent, management of chronic disease, and palliative control of advanced breast cancer. Next, the potential of novel drugs that target DNA repair, growth factor dependence, intracellular and intercellular signal transduction, and cell cycle are considered. Estrogen-related receptor alpha has attracted attention as a therapeutic target in triple-negative breast cancers with de novo resistance to, and in breast cancers with acquired resistance to, endocrine therapies such as antiestrogens and aromatase inhibitors. Estrogen-related receptor alpha is an orphan receptor and transcription factor. Its activity is regulated by coregulator proteins and posttranslational modification. It is an energy sensor that controls adaptation to energy demand and may facilitate glycolytic metabolism and mitochondrial oxidative respiration in breast cancer cells. Estrogen-related receptor alpha increases breast cancer cell migration, proliferation, and tumor development. It is expressed at high levels in estrogen receptor-negative tumors, and is proposed to activate estrogen-responsive genes in endocrine-resistant tumors. The structures and functions of the ligand-binding domains of estrogen receptor alpha and estrogen-related receptor alpha, their ability to bind estrogens, phytoestrogens, and synthetic ligands, and the effects of ligand agonists, antagonists, and inverse agonists on biological activity, are evaluated. Synthetic ligands of estrogen-related receptor alpha have activity in preclinical models of metabolic disorders, diabetes, osteoporosis, and oncology. The clinical settings in which these novel

  4. Subthalamic nucleus activity optimizes maximal effort motor responses in Parkinson's disease.

    Science.gov (United States)

    Anzak, Anam; Tan, Huiling; Pogosyan, Alek; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Hariz, Marwan; Ashkan, Keyoumars; Bogdanovic, Marko; Green, Alexander L; Aziz, Tipu; Brown, Peter

    2012-09-01

    The neural substrates that enable individuals to achieve their fastest and strongest motor responses have long been enigmatic. Importantly, characterization of such activities may inform novel therapeutic strategies for patients with hypokinetic disorders, such as Parkinson's disease. Here, we ask whether the basal ganglia may play an important role, not only in the attainment of maximal motor responses under standard conditions but also in the setting of the performance enhancements known to be engendered by delivery of intense stimuli. To this end, we recorded local field potentials from deep brain stimulation electrodes implanted bilaterally in the subthalamic nuclei of 10 patients with Parkinson's disease, as they executed their fastest and strongest handgrips in response to a visual cue, which was accompanied by a brief 96-dB auditory tone on random trials. We identified a striking correlation between both theta/alpha (5-12 Hz) and high-gamma/high-frequency (55-375 Hz) subthalamic nucleus activity and force measures, which explained close to 70% of interindividual variance in maximal motor responses to the visual cue alone, when patients were ON their usual dopaminergic medication. Loud auditory stimuli were found to enhance reaction time and peak rate of development of force still further, independent of whether patients were ON or OFF l-DOPA, and were associated with increases in subthalamic nucleus power over a broad gamma range. However, the contribution of this broad gamma activity to the performance enhancements observed was only modest (≤13%). The results implicate frequency-specific subthalamic nucleus activities as substantial factors in optimizing an individual's peak motor responses at maximal effort of will, but much less so in the performance increments engendered by intense auditory stimuli.

  5. Intermediate-energy nuclear photoabsorption and the pion optical potential

    International Nuclear Information System (INIS)

    Christillin, P.

    1984-01-01

    Nuclear photoabsorption around the pion threshold is schematised as photoproduction of a pion which undergoes final-stae interaction with the nucleus, accounted for by the pion optical potential. It is shown that real pion photoproduction and exchange effects are naturally described by the same mechanism with a non-static pion. The complementarity of photoabsorption to pion physics and its usefulness in gaining new information about pion-nucleus dynamics are stressed. (author)

  6. Structures and functions in the crowded nucleus: new biophysical insights

    Directory of Open Access Journals (Sweden)

    Ronald eHancock

    2014-09-01

    Full Text Available Concepts and methods from the physical sciences have catalysed remarkable progress in understanding the cell nucleus in recent years. To share this excitement with physicists and encourage their interest in this field, this review offers an overview of how the physics which underlies structures and functions in the nucleus is becoming more clear thanks to methods which have been developed to simulate and study macromolecules, polymers, and colloids. The environment in the nucleus is very crowded with macromolecules, making entropic (depletion forces major determinants of interactions. Simulation and experiments are consistent with their key role in forming membraneless compartments such as nucleoli, PML and Cajal bodies, and discrete territories for chromosomes. The chromosomes, giant linear polyelectrolyte polymers, exist in vivo in a state like a polymer melt. Looped conformations are predicted in crowded conditions, and have been confirmed experimentally and are central to the regulation of gene expression. Polymer theory has revealed how the chromosomes are so highly compacted in the nucleus, forming a crumpled globule with fractal properties which avoids knots and entanglements in DNA while allowing facile accessibility for its replication and transcription. Entropic repulsion between looped polymers can explain the confinement of each chromosome to a discrete region of the nucleus. Crowding and looping are predicted to facilitate finding the specific targets of factors which modulate activities of DNA. Simulation shows that entropic effects contribute to finding and repairing potentially lethal double-strand breaks in DNA by increasing the mobility of the broken ends, favouring their juxtaposition for repair. Signaling pathways are strongly influenced by crowding, which favours a processive mode of response (consecutive reactions without releasing substrates. This new information contributes to understanding the sometimes counter

  7. Perspective of ultrarelativistic nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Specht, H.J.

    1985-01-01

    The paper concerns the lectures given at the International School of nuclear physics, Erice, 1985, which survey the expectations for the field of ultrarelativistic nucleus-nucleus collisions. The primary motivation for the field, the organization of the lectures, and a description of the NA 34 experiment, are all briefly given. (U.K.)

  8. Wandering in the Lyman-alpha forest: a study of dark matter-dark radiation interactions

    Energy Technology Data Exchange (ETDEWEB)

    Krall, Rebecca; Cyr-Racine, Francis-Yan; Dvorkin, Cora, E-mail: rkrall@physics.harvard.edu, E-mail: fcyrraci@physics.harvard.edu, E-mail: dvorkin@physics.harvard.edu [Harvard University, Department of Physics, Cambridge, MA 02138 (United States)

    2017-09-01

    The amplitude of large-scale matter fluctuations inferred from the observed Sunyaev-Zeldovich (SZ) cluster mass function and from weak gravitational lensing studies, when taken at face value, is in tension with measurements of the cosmic microwave background (CMB) and baryon acoustic oscillation (BAO). In this work, we revisit whether this possible discrepancy can be attributed to new interactions in the dark matter sector. Focusing on a cosmological model where dark matter interacts with a dark radiation species until the epoch of matter-radiation equality, we find that measurements of the Lyman-alpha flux power spectrum from the Sloan Digital Sky Survey provide no support to the hypothesis that new dark matter interactions can resolve the possible tension between CMB and large-scale structure (LSS). Indeed, while the addition of dark matter-dark radiation interactions leads to an improvement of 2ΔlnL=12 with respect to the standard Λ cold dark matter (ΛCDM) model when only CMB, BAO, and LSS data are considered, the inclusion of Lyman-alpha data reduces the improvement of the fit to 2ΔlnL=6 relative to ΛCDM . We thus conclude that the statistical evidence for new dark matter interactions (largely driven by the Planck SZ dataset) is marginal at best, and likely caused by systematics in the data. We also perform a Fisher forecast analysis for the reach of a future dataset composed of a CMB-S4 experiment combined with the Large Synoptic Survey Telescope galaxy survey. We find that the constraint on the effective number of fluid-like dark radiation species, Δ N {sub fluid}, will be improved by an order of magnitude compared to current bounds.

  9. C595 antibody: A potential vector for targeted alpha therapy

    International Nuclear Information System (INIS)

    Perkins, A.C.; Allen, B.J.

    2005-01-01

    experimental studies have concentrated on the targeted therapy of carcinoma of the prostate, pancreas and ovary. On 120 paraffin embedded specimens from patients who underwent radical retro-pubic prostatectomy or trans-urethralresection of the prostate for primary untreated carcinoma of the pancreas MUC1 expression was detected in 58% primary Ca prostate tissues and 90% lymph node metastases but not in normal prostates or benign tissues. The 213 Bi-C595 conjugate demonstrated cell killing in PC-3 and DU 145 cell lines isolated from human prostatic adenocarcinoma. Other results indicate that 213 Bi-C595 targeting efficacy is in accordance with the expression of MUC1 in three pancreatic cancer cell clusters CFPAC-1, PANC-1 and CAPAN-1 and demonstrated effective toxicity of tumour spheroids of up to 100 m in diameter. When administered to tumour bearing mice at 333 MBq/kg the c595 alpha conjugate caused significant tumour growth delay, compared with the non-specific control at after 16 weeks. Similar results have been obtained in monolayers and cell clusters of the ovarian OVCAR-3 cell line. We believe this antibody conjugate offers great potential for targeted alpha therapy of prostatic, pancreatic and ovarian tumours. (author)

  10. The heavy quarkonium spectrum at order $m\\alpha_{s}^{5}\\ln\\alpha_{s}$

    CERN Document Server

    Brambilla, Nora; Soto, Joan; Vairo, Antonio

    1999-01-01

    We compute the complete leading-log terms of the next-to-next-to-next-to-leading-order corrections to potential NRQCD. As a by-product we obtain the leading logs at $O(m\\alpha_s^5)$ in the heavy quarkonium spectrum. These leading logs, when $\\Lambda_{QCD} \\ll m\\alpha_s^2$, give the complete $O(m\\alpha_s^5 \\ln \\alpha_s)$ corrections to the heavy quarkonium spectrum.

  11. How deep is the antinucleon optical potential at FAIR energies

    International Nuclear Information System (INIS)

    Gaitanos, T.; Kaskulov, M.; Lenske, H.

    2011-01-01

    The key question in the interaction of antinucleons in the nuclear medium concerns the deepness of the antinucleon-nucleus optical potential. In this work we study this task in the framework of the non-linear derivative (NLD) model which describes consistently bulk properties of nuclear matter and Dirac phenomenology of nucleon-nucleus interactions. We apply the NLD model to antinucleon interactions in nuclear matter and find a strong decrease of the vector and scalar self-energies in energy and density and thus a strong suppression of the optical potential at zero momentum and, in particular, at FAIR energies. This is in agreement with available empirical information and, therefore, resolves the issue concerning the incompatibility of G-parity arguments in relativistic mean-field (RMF) models. We conclude the relevance of our results for the future activities at FAIR.

  12. Ion-beam spectroscopic studies of the 69As nucleus

    International Nuclear Information System (INIS)

    Badica, T.; Cojocaru, V.; Olariu, A.; Petre, M.; Popescu, I. V.; Gheboianu, A.

    2009-01-01

    Excited state of the neutron deficient 69 As nucleus were investigated in the 58 Ni( 14 N,2pn) reaction by ion-beam γ spectroscopic methods (excitation functions, γγ-coincidences, angular distributions and linear polarization gated with neutrons). A new more complete level scheme of 69 As has been proposed with spin-parity values. The structure of the nucleus is discussed in the framework of the interaction boson-fermion model (IBFM). (authors)

  13. Rapidity distributions of secondary particles in hadron-nucleus collisions

    International Nuclear Information System (INIS)

    Alaverdyan, G.B.; Pak, A.S.; Tarasov, A.V.; Tseren, Ch.; Uzhinsky, V.V.

    1979-01-01

    In the framework of the cascade model of a leading particle the rapidity distributions of secondary particles in the hadron-nucleus interactions are considered. The energy loss fluctuations of leading particles in the successive collisions have been taken into account. It is shown that the centre of rapidity distribution is displaced towards small rapidity with target nucleus atomic number A growth. The model well reproduces the energy and A dependences of the rapidity distributions

  14. Global features of nucleus-nucleus collisions in ultrarelativistic domain

    International Nuclear Information System (INIS)

    Savina, M.V.; Shmatov, S.V.; Slavin, N.V.; Zarubin, P.I.

    1998-01-01

    HIJING generator simulation of nucleus-nucleus collisions at ultrarelativistic energies is presented. It is shown that the global characteristics of nucleus-nucleus collisions, such as distribution of a charged multiplicity, total and electromagnetic transverse energy over pseudorapidity are rather sensitive to some predictions of models of high-exited nuclear medium formation, namely parton energy losses in dense nuclear matter. These losses result in appearance of a broad maximum in global variable distributions over pseudorapidity. The most profound of this effect occurs at central heavy ion collisions at LHC energy

  15. Diatomic interaction potential theory applications

    CERN Document Server

    Goodisman, Jerry

    2013-01-01

    Diatomic Interaction Potential Theory, Volume 2: Applications discusses the variety of applicable theoretical material and approaches in the calculations for diatomic systems in their ground states. The volume covers the descriptions and illustrations of modern calculations. Chapter I discusses the calculation of the interaction potential for large and small values of the internuclear distance R (separated and united atom limits). Chapter II covers the methods used for intermediate values of R, which in principle means any values of R. The Hartree-Fock and configuration interaction schemes des

  16. Scaling phenomenon in relativistic nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Wong, C.Y.; Blankenbecler, R.

    1980-01-01

    New scaling variables for proton and pion production in relativistic nucleus-nucleus collisions are introduced which are the generalizations of the Feynmann scaling variable. They allow a simple description of the cross sections at forward and backward angles. 2 figures

  17. Possible Existence of (cc¯)–Nucleus Bound States

    International Nuclear Information System (INIS)

    Yokota, Akira; Oka, Makoto; Hiyama, Emiko

    2014-01-01

    Charmonium (cc¯) bound states in few-nucleon systems, 2 H, 4 He and 8 Be, are studied via Gaussian Expansion Method (GEM). We adopt a Gaussian potential as an effective (cc¯)–nucleon (N) interaction. The relation between two-body (cc¯)–N scattering length a cc¯−N and the binding energies B of (cc¯)–nucleus bound states are given. Recent lattice QCD data of a cc¯−N corresponds to B≃0.5 MeV for (cc¯)− 4 He and 2 MeV for (cc¯)− 8 Be in our results. (author)

  18. Whole-body irradiation transiently diminishes the adrenocorticotropin response to recombinant human interleukin-1{alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Perlstein, R.S.; Mehta, N.R.; Neta, R.; Whitnall, M.H. [Armed Forces Radiobiology Research Institute, Bethesda, MD (United States); Mougey, E.H. [Walter Reed Army Institute of Research, Washington, DC (United States)

    1995-03-01

    Recombinant human interleukin-1{alpha} (rhIL-1{alpha}) has significant potential as a radioprotector and/or treatment for radiation-induced hematopoietic injury. Both IL-1 and whole-body ionizing irradiation acutely stimulate the hypothalamic-pituitary-adrenal axis. We therefore assessed the interaction of whole-body irradiation and rhIL-1{alpha} in altering the functioning of the axis in mice. Specifically, we determined the adrenocorticotropin (ACTH) and corticosterone responses to rhIL-1{alpha} administered just before and hours to days after whole-body or sham irradiation. Our results indicate that whole-body irradiation does not potentiate the rhIL-1{alpha}-induced increase in ACTH levels at the doses used. In fact, the rhIL-1{alpha}-induced increase in plasma ACTH is transiently impaired when the cytokine is administered 5 h after, but not 1 h before, exposure to whole-body irradiation. The ACTH response may be inhibited by elevated corticosterone levels after whole-body irradiation, or by other radiation-induced effects on the pituitary gland and hypothalamus. 36 refs., 3 figs.

  19. Experimental studies of nucleon-nucleon and pion-nucleus interactions at intermediate energies: Progress report, January 1, 1985-December 31, 1987

    International Nuclear Information System (INIS)

    1987-01-01

    This report summarizes the work on experimental research in intermediate energy nuclear and particle physics carried out by New Mexico State University in 1985-87. These studies have involved investigations of nucleon-nucleon and pion-nucleus interactions. They have been carried out at the LAMPF accelerator at the Los Alamos National Laboratory, at the SIN laboratory near Zurich, Switzerland, and at the TRIUMF accelerator in Vancouver, Canada. 86 refs., 5 figs

  20. The alpha-fetoprotein (AFP) third domain: a search for AFP interaction sites of cell cycle proteins.

    Science.gov (United States)

    Mizejewski, G J

    2016-09-01

    The carboxy-terminal third domain of alpha-fetoprotein (AFP-3D) is known to harbor binding and/or interaction sites for hydrophobic ligands, receptors, and binding proteins. Such reports have established that AFP-3D consists of amino acid (AA) sequence stretches on the AFP polypeptide that engages in protein-to-protein interactions with various ligands and receptors. Using a computer software program specifically designed for such interactions, the present report identified AA sequence fragments on AFP-3D that could potentially interact with a variety of cell cycle proteins. The cell cycle proteins identified were (1) cyclins, (2) cyclin-dependent kinases, (3) cell cycle-associated proteins (inhibitors, checkpoints, initiators), and (4) ubiquitin ligases. Following detection of the AFP-3D to cell cycle protein interaction sites, the computer-derived AFP localization AA sequences were compared and aligned with previously reported hydrophobic ligand and receptor interaction sites on AFP-3D. A literature survey of the association of cell cycle proteins with AFP showed both positive relationships and correlations. Previous reports of experimental AFP-derived peptides effects on various cell cycle proteins served to confirm and verify the present computer cell cycle protein identifications. Cell cycle protein interactions with AFP-CD peptides have been reported in cultured MCF-7 breast cancer cells subjected to mRNA microarray analysis. After 7 days in culture with MCF-7 cells, the AFP-derived peptides were shown to downregulate cyclin E, SKP2, checkpoint suppressors, cyclin-dependent kinases, and ubiquitin ligases that modulate cyclin E/CdK2 transition from the G1 to the S-phase of the cell cycle. Thus, the experimental data on AFP-CD interaction with cell cycle proteins were consistent with the "in silico" findings.

  1. Topics in nuclear chromodynamics: Color transparency and hadronization in the nucleus

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1988-03-01

    The nucleus plays two complimentary roles in quantum chromodynamics: (1) A nuclear target can be used as a control medium or background field to modify or probe quark and gluon subprocesses. Some novel examples are color transparency, the predicted transparency of the nucleus to hadrons participating in high momentum transfer exclusive reactions, and formation zone phenomena, the absence of hard, collinear, target-induced radiation by a quark or gluon interacting in a high momentum transfer inclusive reaction if its energy is large compared to a scale proportional to the length of the target. (Soft radiation and elastic initial state interactions in the nucleus still occur.) Coalescence with co-moving spectators is discussed as a mechanism which can lead to increased open charm hadroproduction, but which also suppresses forward charmonium production (relative to lepton pairs) in heavy ion collisions. Also discussed are some novel features of nuclear diffractive amplitudes--high energy hadronic or electromagnetic reactions which leave the entire nucleus intact and give nonadditive contributions to the nuclear structure function at low /kappa cur//sub Bj/. (2) Conversely, the nucleus can be studied as a QCD structure. At short distances, nuclear wave functions and nuclear interactions necessarily involve hidden color, degrees of freedom orthogonal to the channels described by the usual nucleon or isobar degrees of freedom. At asymptotic momentum transfer, the deuteron form factor and distribution amplitude are rigorously calculable. One can also derive new types of testable scaling laws for exclusive nuclear amplitudes in terms of the reduced amplitude formalism

  2. Interacting cannabinoid and opioid receptors in the nucleus accumbens core control adolescent social play

    Directory of Open Access Journals (Sweden)

    Antonia Manduca

    2016-11-01

    Full Text Available Social play behavior is a highly rewarding, developmentally important form of social interaction in young mammals. However, its neurobiological underpinnings remain incompletely understood. Previous work has suggested that opioid and endocannabinoid neurotransmission interact in the modulation of social play. Therefore, we combined behavioral, pharmacological, electrophysiological and genetic approaches to elucidate the role of the endocannabinoid 2-arachidonoylglycerol (2-AG in social play, and how cannabinoid and opioid neurotransmission interact to control social behavior in adolescent rodents. Systemic administration of the 2-AG hydrolysis inhibitor JZL184 or the opioid receptor agonist morphine increased social play behavior in adolescent rats. These effects were blocked by systemic pretreatment with either CB1 cannabinoid receptor (CB1R or mu-opioid receptor (MOR antagonists. The social play-enhancing effects of systemic morphine or JZL184 treatment were also prevented by direct infusion of the CB1R antagonist SR141716 and the MOR antagonist naloxone into the nucleus accumbens core (NAcC. Searching for synaptic correlates of these effects in adolescent NAcC excitatory synapses, we observed that CB1R antagonism blocked the effect of the MOR agonist DAMGO and, conversely, that naloxone reduced the effect of a cannabinoid agonist. These results were recapitulated in mice, and completely abolished in CB1R and MOR knockout mice, suggesting that the functional interaction between CB1R and MOR in the NAcC in the modulation of mediates social behavior is widespread in rodents. The data shed new light on the mechanism by which endocannabinoid lipids and opioid peptides interact to orchestrate rodent socioemotional behaviors.

  3. A reassessment of the potential for an alpha-mode containment failure and a review of the current understanding of broader fuel-coolant interaction issues. Second steam explosion review group workshop

    Energy Technology Data Exchange (ETDEWEB)

    Basu, S. [Nuclear Regulatory Commission, Washington, DC (United States); Ginsberg, T. [Brookhaven National Lab., Upton, NY (United States)

    1996-08-01

    This report summarizes the review and evaluation by experts of the current understanding of the molten fuel-coolant interaction (FCI) issues covering the complete spectrum of interactions, i.e., from mild quenching to very energetic interactions including those that could lead to the alpha-mode containment failure. Of the eleven experts polled, all but two concluded that the alpha-mode failure issue was resolved from a risk perspective, meaning that this mode of failure is of very low probability, that it is of little or no significance to the overall risk from a nuclear power plant, and that any further reduction in residual uncertainties is not likely to change the probability in an appreciable manner. To a lesser degree, discussions also took place on the broader FCI issues such as mild quenching of core melt during non-explosive FCI, and shock loading of lower head and ex-vessel support structures arising from explosive localized FCIs. These latter issues are relevant with regard to determining the efficacy of certain accident management strategies for operating reactors as well as for advanced light water reactors. The experts reviewed the status of understanding of the FCI phenomena in the context of these broader issues, identified residual uncertainties in the understanding, and recommended future research (both experimental and analytical) to reduce the uncertainties.

  4. A reassessment of the potential for an alpha-mode containment failure and a review of the current understanding of broader fuel-coolant interaction issues. Second steam explosion review group workshop

    International Nuclear Information System (INIS)

    Basu, S.; Ginsberg, T.

    1996-08-01

    This report summarizes the review and evaluation by experts of the current understanding of the molten fuel-coolant interaction (FCI) issues covering the complete spectrum of interactions, i.e., from mild quenching to very energetic interactions including those that could lead to the alpha-mode containment failure. Of the eleven experts polled, all but two concluded that the alpha-mode failure issue was resolved from a risk perspective, meaning that this mode of failure is of very low probability, that it is of little or no significance to the overall risk from a nuclear power plant, and that any further reduction in residual uncertainties is not likely to change the probability in an appreciable manner. To a lesser degree, discussions also took place on the broader FCI issues such as mild quenching of core melt during non-explosive FCI, and shock loading of lower head and ex-vessel support structures arising from explosive localized FCIs. These latter issues are relevant with regard to determining the efficacy of certain accident management strategies for operating reactors as well as for advanced light water reactors. The experts reviewed the status of understanding of the FCI phenomena in the context of these broader issues, identified residual uncertainties in the understanding, and recommended future research (both experimental and analytical) to reduce the uncertainties

  5. S100A4 interacts with p53 in the nucleus and promotes p53 degradation.

    Science.gov (United States)

    Orre, L M; Panizza, E; Kaminskyy, V O; Vernet, E; Gräslund, T; Zhivotovsky, B; Lehtiö, J

    2013-12-05

    S100A4 is a small calcium-binding protein that is commonly overexpressed in a range of different tumor types, and it is widely accepted that S100A4 has an important role in the process of cancer metastasis. In vitro binding assays has shown that S100A4 interacts with the tumor suppressor protein p53, indicating that S100A4 may have additional roles in tumor development. In the present study, we show that endogenous S100A4 and p53 interact in complex samples, and that the interaction increases after inhibition of MDM2-dependent p53 degradation using Nutlin-3A. Further, using proximity ligation assay, we show that the interaction takes place in the cell nucleus. S100A4 knockdown experiments in two p53 wild-type cell lines, A549 and HeLa, resulted in stabilization of p53 protein, indicating that S100A4 is promoting p53 degradation. Finally, we demonstrate that S100A4 knockdown leads to p53-dependent cell cycle arrest and increased cisplatin-induced apoptosis. Thus, our data add a new layer to the oncogenic properties of S100A4 through its inhibition of p53-dependent processes.

  6. Study of Λ-production in central nucleus-nucleus interactions at the momentum of 4.6 GeV/c per incident nucleon

    International Nuclear Information System (INIS)

    Anikina, M.; Golokhvastov, A.; Goncharova, L.

    1983-01-01

    Transverse momenta and rapidities of Λ particles produced in central nucleus-nucleus collisions at 4.5 GeV/c per nucleon (cC, CNe, ONe, CCu, CZr, CPb, OPb) have been studied and compared with those from ineiolastic He-Li interactns at the same incident momentum. Polarization of Λ hyperons was found to be consistent (within the errors) with zero (αP=-0.06+-0.11) for 224 Λ particles from central collisions. The upper limit of anti Λ/Λ production ratio was estimated to be less than 10 -2 at a 90% confidence level. The analyzed experimental data were obtained using the triggered 2 m streamer spectrometer SKM-200

  7. Neutrino-nucleus neutral current elastic interactions measurement in MiniBooNE

    Science.gov (United States)

    Perevalov, Denis

    The MiniBooNE experiment at the Fermi National Accelerator Laboratory (Fermilab) was designed to search for numu → nu e neutrino oscillations at Deltam 2 ˜ 1 eV2 using an intense neutrino flux with an average energy Enu ˜ 700 MeV. From 2002 to 2009 MiniBooNE has accumulated more than 1.0x1021 protons on target (POT) in both neutrino and antineutrino modes. MiniBooNE provides a perfect platform for detailed measurements of exclusive and semi-inclusive neutrino cross-sections, for which MiniBooNE has the largest samples of events up to date, such as neutral current elastic (NCE), neutral current pi 0, charged current quasi-elastic (CCQE), charged current pi +, and other channels. These measured cross-sections, in turn, allow to improve the knowledge of nucleon structure. This thesis is devoted to the study of NCE interactions. Neutrino-nucleus neutral current elastic scattering (nuN → nu N) accounts for about 18% of all neutrino interactions in MiniBooNE. Using a high-statistics, high purity sample of NCE interactions in MiniBooNE, the flux-averaged NCE differential cross-section has been measured and is being reported here. Further study of the NCE cross-section allowed for probing the structure of nuclei. The main interest in the NCE cross-section is that it may be sensitive to the strange quark contribution to the nucleon spin, Deltas, this however requires a separation of NCE proton (nup → nu p) from NCE neutron (nun → nun ) events, which in general is a challenging task. MiniBooNE uses a Cherenkov detector, which imposes restrictions on the measured nucleon kinematic variables, mainly due to the impossibility to reconstruct the nucleon direction below the Cherenkov threshold. However, at kinetic energies above this threshold MiniBooNE is able to identify NCE proton events that do not experience final state interactions (FSI). These events were used for the Deltas measurement. In this thesis MiniBooNE reports the NCE (n+p) cross-section, the measurement

  8. Signaling from the secretory granule to the nucleus: Uhmk1 and PAM.

    Science.gov (United States)

    Francone, Victor P; Ifrim, Marius F; Rajagopal, Chitra; Leddy, Christopher J; Wang, Yanping; Carson, John H; Mains, Richard E; Eipper, Betty A

    2010-08-01

    Neurons and endocrine cells package peptides in secretory granules (large dense-core vesicles) for storage and stimulated release. Studies of peptidylglycine alpha-amidating monooxygenase (PAM), an essential secretory granule membrane enzyme, revealed a pathway that can relay information from secretory granules to the nucleus, resulting in alterations in gene expression. The cytosolic domain (CD) of PAM, a type 1 membrane enzyme essential for the production of amidated peptides, is basally phosphorylated by U2AF homology motif kinase 1 (Uhmk1) and other Ser/Thr kinases. Proopiomelanocortin processing in AtT-20 corticotrope tumor cells was increased when Uhmk1 expression was reduced. Uhmk1 was concentrated in the nucleus, but cycled rapidly between nucleus and cytosol. Endoproteolytic cleavage of PAM releases a soluble CD fragment that localizes to the nucleus. Localization of PAM-CD to the nucleus was decreased when PAM-CD with phosphomimetic mutations was examined and when active Uhmk1 was simultaneously overexpressed. Membrane-tethering Uhmk1 did not eliminate its ability to exclude PAM-CD from the nucleus, suggesting that cytosolic Uhmk1 could cause this response. Microarray analysis demonstrated the ability of PAM to increase expression of a small subset of genes, including aquaporin 1 (Aqp1) in AtT-20 cells. Aqp1 mRNA levels were higher in wild-type mice than in mice heterozygous for PAM, indicating that a similar relationship occurs in vivo. Expression of PAM-CD also increased Aqp1 levels whereas expression of Uhmk1 diminished Aqp1 expression. The outlines of a pathway that ties secretory granule metabolism to the transcriptome are thus apparent.

  9. Report of the 7. Workshop on hadron interactions

    International Nuclear Information System (INIS)

    Hama, Y.; Navarra, F.S.; Nielsen, M.

    1994-06-01

    A report on the 7. workshop on hadron interactions is presented. Several works, both theoretical and experimental, on progress in hadron-hadron, hadron-nucleus and nucleus-nucleus interactions at very high energies are discussed. This includes cosmic ray interaction also

  10. Modulation of Somatosensory Alpha Rhythm by Transcranial Alternating Current Stimulation at Mu-Frequency

    Directory of Open Access Journals (Sweden)

    Christopher Gundlach

    2017-08-01

    Full Text Available Introduction: Transcranial alternating current stimulation (tACS is emerging as an interventional tool to modulate different functions of the brain, potentially by interacting with intrinsic ongoing neuronal oscillations. Functionally different intrinsic alpha oscillations are found throughout the cortex. Yet it remains unclear whether tACS is capable of specifically modulating the somatosensory mu-rhythm in amplitude.Objectives: We used tACS to modulate mu-alpha oscillations in amplitude. When compared to sham stimulation we expected a modulation of mu-alpha oscillations but not visual alpha oscillations by tACS.Methods: Individual mu-alpha frequencies were determined in 25 participants. Subsequently, blocks of tACS with individual mu-alpha frequency and sham stimulation were applied over primary somatosensory cortex (SI. Electroencephalogram (EEG was recorded before and after either stimulation or sham. Modulations of mu-alpha and, for control, visual alpha amplitudes were then compared between tACS and sham.Results: Somatosensory mu-alpha oscillations decreased in amplitude after tACS was applied at participants’ individual mu-alpha frequency. No changes in amplitude were observed for sham stimulation. Furthermore, visual alpha oscillations were not affected by tACS or sham, respectively.Conclusion: Our results demonstrate the capability of tACS to specifically modulate the targeted somatosensory mu-rhythm when the tACS frequency is tuned to the individual endogenous rhythm and applied over somatosensory areas. Our results are in contrast to previously reported amplitude increases of visual alpha oscillations induced by tACS applied over visual cortex. Our results may point to a specific interaction between our stimulation protocol and the functional architecture of the somatosensory system.

  11. Formin' actin in the nucleus.

    Science.gov (United States)

    Baarlink, Christian; Grosse, Robert

    2014-01-01

    Many if not most proteins can, under certain conditions, change cellular compartments, such as, for example, shuttling from the cytoplasm to the nucleus. Thus, many proteins may exert functions in various and very different subcellular locations, depending on the signaling context. A large amount of actin regulatory proteins has been detected in the mammalian cell nucleus, although their potential roles are much debated and are just beginning to emerge. Recently, members of the formin family of actin nucleators were also reported to dynamically localize to the nuclear environment. Here we discuss our findings that specific diaphanous-related formins can promote nuclear actin assembly in a signal-dependent manner.

  12. Modulation of the transient receptor potential vanilloid channel TRPV4 by 4alpha-phorbol esters: a structure-activity study

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjaer; Pagani, Alberto; Minassi, Alberto

    2009-01-01

    The mechanism of activation of the transient receptor potential vanilloid 4 (TRPV4) channel by 4alpha-phorbol esters was investigated by combining information from chemical modification of 4alpha-phorbol-didecanoate (4alpha-PDD, 2a), site-directed mutagenesis, Ca(2+) imaging, and electrophysiology....... Binding of 4alpha-phorbol esters occurs in a loop in the TM3-TM4 domain of TRPV4 that is analogous to the capsaicin binding site of TRPV1, and the ester decoration of ring C and the A,B ring junction are critical for activity. The lipophilic ester groups on ring C serve mainly as a steering element...

  13. Modeling of MeV alpha particle energy transfer to lower hybrid waves

    International Nuclear Information System (INIS)

    Schivell, J.; Monticello, D.A.; Fisch, N.; Rax, J.M.

    1993-10-01

    The interaction between a lower hybrid wave and a fusion alpha particle displaces the alpha particle simultaneously in space and energy. This results in coupled diffusion. Diffusion of alphas down the density gradient could lead to their transferring energy to the wave. This could, in turn, put energy into current drive. An initial analytic study was done by Fisch and Rax. Here the authors calculate numerical solutions for the alpha energy transfer and study a range of conditions that are favorable for wave amplification from alpha energy. They find that it is possible for fusion alpha particles to transfer a large fraction of their energy to the lower hybrid wave. The numerical calculation shows that the net energy transfer is not sensitive to the value of the diffusion coefficient over a wide range of practical values. An extension of this idea, the use of a lossy boundary to enhance the energy transfer, is investigated. This technique is shown to offer a large potential benefit

  14. Alpha Particles and X Rays Interact in Inducing DNA Damage in U2OS Cells.

    Science.gov (United States)

    Sollazzo, Alice; Brzozowska, Beata; Cheng, Lei; Lundholm, Lovisa; Haghdoost, Siamak; Scherthan, Harry; Wojcik, Andrzej

    2017-10-01

    Survivors of the atomic bombings of Hiroshima and Nagasaki are monitored for health effects within the Life Span Study (LSS). The LSS results represent the most important source of data about cancer effects from ionizing radiation exposure, which forms the foundation for the radiation protection system. One uncertainty connected to deriving universal risk factors from these results is related to the problem of mixed radiation qualities. The A-bomb explosions generated a mixed beam of the sparsely ionizing gamma radiation and densely ionizing neutrons. However, until now the possible interaction of the two radiation types of inducing biological effects has not been taken into consideration. The existence of such interaction would suggest that the application of risk factors derived from the LSS to predict cancer effects after pure gamma-ray irradiation (such as in the Fukushima prefecture) leads to an overestimation of risk. To analyze the possible interaction of radiation types, a mixed-beam exposure facility was constructed where cells can be exposed to sparsely ionizing X rays and densely ionizing alpha particles. U2OS cells were used, which are stably transfected with a plasmid coding for the DNA repair gene 53BP1 coupled to a gene coding for the green fluorescent protein (GFP). The induction and repair of DNA damage, which are known to be related to cancer induction, were analyzed. The results suggest that alpha particles and X rays interact, leading to cellular and possibly cancer effects, which cannot be accurately predicted based on assuming simple additivity of the individual mixed-beam components.

  15. Adaptation of the TH Epsilon Mu formalism for the analysis of the equivalence principle in the presence of the weak and electroweak interaction

    Science.gov (United States)

    Fennelly, A. J.

    1981-01-01

    The TH epsilon mu formalism, used in analyzing equivalence principle experiments of metric and nonmetric gravity theories, is adapted to the description of the electroweak interaction using the Weinberg-Salam unified SU(2) x U(1) model. The use of the TH epsilon mu formalism is thereby extended to the weak interactions, showing how the gravitational field affects W sub mu (+ or -1) and Z sub mu (0) boson propagation and the rates of interactions mediated by them. The possibility of a similar extension to the strong interactions via SU(5) grand unified theories is briefly discussed. Also, using the effects of the potentials on the baryon and lepton wave functions, the effects of gravity on transition mediated in high-A atoms which are electromagnetically forbidden. Three possible experiments to test the equivalence principle in the presence of the weak interactions, which are technologically feasible, are then briefly outline: (1) K-capture by the FE nucleus (counting the emitted X-ray); (2) forbidden absorption transitions in high-A atoms' vapor; and (3) counting the relative Beta-decay rates in a suitable alpha-beta decay chain, assuming the strong interactions obey the equivalence principle.

  16. Quarkonia Photoproduction at Nucleus Colliders

    International Nuclear Information System (INIS)

    D'Enterria, David

    2008-01-01

    Exclusive photoproduction of heavy quarkonia in high-energy ultraperipheral ion-ion interactions (γ A →V A, where V = J/ψ, Y and the nucleus A remains intact) offers a useful means to constrain the small-x nuclear gluon density. We discuss preliminary results on J/ψ photoproduction in Au-Au collisions at RHIC [D. d'Enterria [PHENIX Collaboration], Proceeds. Quark Matter'05, (arXiv:nucl-ex/0601001)], as well as full simulation-reconstruction studies of photo-produced Y in Pb-Pb interactions at the LHC [D. d'Enterria (ed.) et al. [CMS Collaboration], J. Phys. G. 34 2307 (2007)

  17. Quasi-elastic shadowing in nucleus-nucleus elastic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Dymarz, R; Malecki, A [Institute of Nuclear Physics, Krakow (Poland); Gluski, K [Institute of Nuclear Research, Warsaw (Poland); Picchi, P [Turin Univ. (Italy). Ist. di Fisica; Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica)

    1979-01-06

    The complete evaluation of the Glauber multiple-scattering series for nucleus-nucleus collisions is a very difficult task and that is why various approximate formulae were proposed. In this work some of these approximations are discussed.

  18. Exact multiple scattering theory of two-nucleus collisions including the Pauli principle

    International Nuclear Information System (INIS)

    Gurvitz, S.A.

    1981-01-01

    Exact equations for two-nucleus scattering are derived in which the effects of the Pauli principle are fully included. Our method exploits a modified equation for the scattering of two identical nucleons, which is obtained at the beginning. Considering proton-nucleus scattering we found that the resulting amplitude has two components, one resembling a multiple scattering series for distinguishable particles, and the other a distorted (A-1) nucleon cluster exchange. For elastic pA scattering the multiple scattering amplitude is found in the form of an optical potential expansion. We show that the Kerman-McManus-Thaler theory of the optical potential could be easily modified to include the effects of antisymmetrization of the projectile with the target nucleons. Nucleus-nucleus scattering is studied first for distinguishable target and beam nucleus. Afterwards the Pauli principle is included, where only the case of deuteron-nucleus scattering is discussed in detail. The resulting amplitude has four components. Two of them correspond to modified multiple scattering expansions and the others are distorted (A-1)- and (A-2)- nucleon cluster exchange. The result for d-A scattering is extended to the general case of nucleus-nucleus scattering. The equations are simple to use and as such constitute an improvement over existing schemes

  19. Interaction of alpha radiation with thermally-induced defects in silicon

    International Nuclear Information System (INIS)

    Ali, Akbar; Majid, Abdul

    2008-01-01

    The interaction of radiation-induced defects created by energetic alpha particles and thermally-induced defects in silicon has been studied using a Deep Level Transient Spectroscopy (DLTS) technique. Two thermally-induced defects at energy positions E c -0.48 eV and E c -0.25 eV and three radiation-induced defects E2, E3 and E5 have been observed. The concentration of both of the thermally-induced defects has been observed to increase on irradiation. It has been noted that production rates of the radiation-induced defects are suppressed in the presence of thermally-induced defects. A significant difference in annealing characteristics of thermally-induced defects in the presence of radiation-induced defects has been observed compared to the characteristics measured in pre-irradiated samples

  20. Development of Colle-Salvetti type electron-nucleus correlation functional for MC-DFT

    Energy Technology Data Exchange (ETDEWEB)

    Udagawa, Taro [Department of Chemistry and Biomolecuar Science, Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu 501-1193 (Japan); Tsuneda, Takao [Fuel Cell Nanomaterials Center, University of Yamanashi, Miyamae-cho 6-43, Kofu 400-0021 (Japan); Tachikawa, Masanori [Quqnatum Chemistry Division, Graduate School of Science, Yokohama City University, Seto 22-2, Kanazawa, Yokohama 236-0027 (Japan)

    2015-12-31

    A Colle-Salvetti type electron-nucleus correlation functional for multicomponent density-functional theory is proposed. We demonstrate that our correlation functional quantitatively reproduces the quantum nuclear effects of protons; the mean absolute deviation value is 2.8 millihartrees for the optimized structure of hydrogen-containing molecules. We also show other practical calculations with our new electron-deuteron and electron-triton correlation functionals. Since this functional is derived without any unphysical assumption, the strategy taken in this development will be a promising recipe to make new functionals for the potentials of other particles’ interactions.

  1. High density QCD and nucleus-nucleus scattering deeply in the saturation region

    International Nuclear Information System (INIS)

    Kormilitzin, Andrey; Levin, Eugene; Miller, Jeremy S.

    2011-01-01

    In this paper we solve the equations that describe nucleus-nucleus scattering, in high density QCD, in the framework of the BFKL Pomeron Calculus. We found that (i) the contribution of short distances to the opacity for nucleus-nucleus scattering dies at high energies, (ii) the opacity tends to unity at high energy, and (iii) the main contribution that survives comes from soft (long distance) processes for large values of the impact parameter. The corrections to the opacity Ω(Y,b)=1 were calculated and it turns out that they have a completely different form, namely (1-Ω→exp(-Const√(Y))) than the opacity that stems from the Balitsky-Kovchegov equation, which is (1-Ω→exp(-ConstY 2 )). We reproduce the formula for the nucleus-nucleus cross section that is commonly used in the description of nucleus-nucleus scattering, and there is no reason why it should be correct in the Glauber-Gribov approach.

  2. Method of a fast selection of inelastic nucleus-nucleus collisions for the CMS experiment

    International Nuclear Information System (INIS)

    Krasnov, V.A.; Malakhov, A.I.; Savina, M.V.; Shmatov, S.V.; Zarubin, P.I.

    1998-01-01

    On the basis of the HIJING generator simulation of heavy ion collisions at ultrarelativistic energy scale, a method of a fast selection of inelastic nucleus-nucleus interactions is proposed for the CMS experiment at LHC. The basic idea is to use the time coincidence of signals with resolution better than 1 ns from the two very forward calorimeter arms covering the acceptance 3<|η|<5. The method efficiency is investigated by variation of energy thresholds in the calorimeters for different colliding ion species, namely, PbPb, NbNb, CaCa, OO, pPb, pCa, pp. It is shown that a stable efficiency of event selection (∼98%) is provided in an energy threshold range up to 100 GeV for nuclear collisions at 5 TeV/nucleon in the centre of mass system. In the pp collision case the relevant efficiency drops from 93% down to 80%

  3. Excitations of one-valence-proton, one-valence-neutron nucleus {sup 210}Bi from cold-neutron capture

    Energy Technology Data Exchange (ETDEWEB)

    Cieplicka-Oryńczak, N. [INFN sezione di Milano, Via Celoria 16, 20133 Milano (Italy); Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Kraków (Poland); Fornal, B.; Szpak, B. [Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Kraków (Poland); Leoni, S.; Bottoni, S. [INFN sezione di Milano, Via Celoria 16, 20133 Milano (Italy); Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Bazzacco, D. [Dipartimento di Fisica e Astronomia dell’Università, I-35131 Padova (Italy); INFN Sezione di Padova, I-35131 Padova (Italy); Blanc, A.; Jentschel, M.; Köster, U.; Mutti, P.; Soldner, T. [Institute Laue-Langevin, 6, rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Bocchi, G. [Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); France, G. de [GANIL, Bd. Becquerel, BP 55027, 14076 CAEN Cedex 05 (France); Simpson, G. [LPSC, Université Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut National Polytechnique de Grenoble, F-38026 Grenoble Cedex (France); Ur, C. [INFN Sezione di Padova, Via F. Marzolo 8, I-35131 Padova (Italy); Urban, W. [Faculty of Physics, University of Warsaw, ul. Hoża 69, 02-681, Warszawa (Poland)

    2015-10-15

    The low-spin structure of one-proton, one-neutron {sup 210}Bi nucleus was investigated in cold-neutron capture reaction on {sup 209}Bi. The γ-coincidence measurements were performed with use of EXILL array consisted of 16 HPGe detectors. The experimental results were compared to shell-model calculations involving valence particles excitations. The {sup 210}Bi nucleus offers the potential to test the effective proton-neutron interactions because most of the states should arise from the proton-neutron excitations. Additionally, it was discovered that a few states should come from the couplings of valence particles to the 3{sup −} octupole vibration in {sup 208}Pb which provides also the possibility of testing the calculations involving the core excitations.

  4. Alpha and beta detection and spectrometry

    International Nuclear Information System (INIS)

    Saro, S.

    1984-01-01

    The theory of alpha and beta radioactive decay, the interaction of alpha and beta particles with matter, and their detection and spectrometry are dealt with in seven chapters: 1. Alpha transformation of atomic nuclei; 2. Basic properties of detectors and statistics of detection; 3. Alpha detectors and spectrometers; 4. Applications of alpha detection and spectrometry; 5. Beta transformation of atomic nuclei; 6. Beta particle detectors and spectrometers; 7. Detection of low energy beta particles. Chapter 8 is devoted to sampling and preparation of samples for radiometry. (E.F.)

  5. Neuroprotective and memory-related actions of novel alpha-7 nicotinic agents with different mixed agonist/antagonist properties.

    Science.gov (United States)

    Meyer, E M; Tay, E T; Zoltewicz, J A; Meyers, C; King, M A; Papke, R L; De Fiebre, C M

    1998-03-01

    The goals of this study were to develop compounds that were selective and highly efficacious agonists at alpha-7 receptors, while varying in antagonist activity; and to test the hypothesis that these compounds had memory-related and neuroprotective actions associated with both agonist and antagonist alpha-7 receptor activities. Three compounds were identified; E,E-3-(cinnamylidene)anabaseine (3-CA), E,E-3-(2-methoxycinnamylidene) anabaseine (2-MeOCA) and E,E-3-(4-methoxycinnamylidene) anabaseine (4-MeOCA) each displaced [125I]alpha-bungarotoxin binding from rat brain membranes and activated rat alpha-7 receptors in a Xenopus oocyte expression system fully efficaciously. The potency series for binding and receptor activation was 2-MeOCA > 4-MeOCA = 3-CA and 2-MeOCA = 3-CA > 4-MeOCA, respectively. No compound significantly activated oocyte-expressed alpha-4beta-2 receptors. Although each cinnamylidene-anabaseine caused a long-term inhibition of alpha-7 receptors, as measured by ACh-application 5 min later, this inhibition ranged considerably, from less than 20% (3-CA) to 90% (2-MeOCA) at an identical concentration (10 microM). These compounds improved passive avoidance behavior in nucleus basalis lesioned rats, with 2-MeOCA most potent in this respect. In contrast, only 3-CA was neuroprotective against neurite loss during nerve growth factor deprivation in differentiated rat pheochromocytoma (PC12) cells. Choline, an efficacious alpha-7 agonist without antagonist activity, was also protective in this model. These results suggest that the neurite-protective action of alpha-7 receptor agonists may be more sensitive to potential long-term antagonist properties than acute behavioral actions are.

  6. The interaction of fast alpha particles with pellet ablation clouds

    International Nuclear Information System (INIS)

    McChesney, J.M.; Parks, P.B.; Fisher, R.K.; Olson, R.E.

    1997-01-01

    The energy spectra of energetic confined alpha particles are being measured using the pellet charge exchange method [R. K. Fisher, J. S. Leffler, A. M. Howald, and P. B. Parks, Fusion Technol. 13, 536 (1988)]. The technique uses the dense ablation cloud surrounding an injected impurity pellet to neutralize a fraction of the incident alpha particles, allowing them to escape from the plasma where their energy spectrum can be measured using a neutral particle analyzer. The signal calculations given in the above-mentioned reference disregarded the effects of the alpha particles' helical Larmor orbits, which causes the alphas to make multiple passes through the cloud. Other effects such as electron ionization by plasma and ablation cloud electrons and the effect of the charge state composition of the cloud, were also neglected. This report considers these issues, reformulates the signal level calculation, and uses a Monte-Carlo approach to calculate the neutralization fractions. The possible effects of energy loss and pitch angle scattering of the alphas are also considered. copyright 1997 American Institute of Physics

  7. The role of non-specific interactions in nuclear organization

    NARCIS (Netherlands)

    Nooijer, de S.

    2010-01-01

    The most important organelle in eukaryotic cells is the nucleus. Many processes occurring within the nucleus depend on spatial organization of the nucleus. The spatial organization of the eukaryotic nucleus derives from interactions between its constituents. Both specific interactions, for instance

  8. Cellular localization of transforming growth factor-alpha mRNA in rat forebrain.

    Science.gov (United States)

    Seroogy, K B; Lundgren, K H; Lee, D C; Guthrie, K M; Gall, C M

    1993-05-01

    The cellular localization of transforming growth factor-alpha (TGF alpha) mRNA in juvenile and adult rat forebrain was examined using in situ hybridization with a 35S-labeled cRNA probe. TGF alpha cRNA-labeled neuronal perikarya were distributed across many forebrain regions including the olfactory bulb, caudate-putamen, nucleus accumbens, olfactory tubercle, ventral pallidum, amygdala, hippocampal stratum granulosum and CA3 stratum pyramidale, and piriform, entorhinal, and retrosplenial cortices. TGF alpha cRNA-hybridizing cells were also localized to several thalamic nuclei and to the suprachiasmatic, dorsomedial, and ventromedial nuclei of the hypothalamus. In addition, labeled cells were present in regions of white matter including the corpus callosum, anterior commissure, internal and external capsules, optic tract, and lateral olfactory tract. Thus, both neurons and glia appear to synthesize TGF alpha in normal brain. Hybridization densities were greater in neuronal fields at 2 weeks of age compared with the adult, suggesting a role for TGF alpha in the development of several forebrain systems. Our results demonstrating the prominent and wide-spread expression of TGF alpha mRNA in forebrain, combined with the extremely low abundance of epidermal growth factor mRNA in brain, support the argument that TGF alpha is the principal endogenous ligand for the epidermal growth factor receptor in normal brain.

  9. Inelasticity in hadron-nucleus collisions in the geometrical two-chain model

    International Nuclear Information System (INIS)

    Wibig, T.; Sobczynska, D.

    1995-01-01

    Two features of great importance registered in experiments on hadron-nucleus collisions are the decreased inelasticity and multiplicity in intranucleus collisions. In this paper we show that such behaviour is a natural consequence of the geometrical two-chain model of multi-particle production processes: only the forward-going chain can undergo secondary interactions in the nucleus. A quantitative comparison with the data is presented. (author)

  10. Barley alpha-amylase/subtilisin inhibitor: structure, biophysics and protein engineering

    DEFF Research Database (Denmark)

    Nielsen, P.K.; Bønsager, Birgit Christine; Fukuda, Kenji

    2004-01-01

    Bifunctional alpha-amylase/subtilisin inhibitors have been implicated in plant defence and regulation of endogenous alpha-amylase action. The barley alpha-amylase/subtilisin inhibitor (BASI) inhibits the barley alpha-amylase 2 (AMY2) and subtilisin-type serine proteases. BASI belongs to the Kunitz...... Ca2+-modulated kinetics of the AMY2/BASl interaction and found that the complex formation involves minimal structural changes. The modulation of the interaction by calcium ions makes it unique among the currently known binding mechanisms of proteinaceous alpha-amylase inhibitors....

  11. Molecular versus squared Woods-Saxon α-nucleus potentials in the 27Al(α, t)28Si reaction

    International Nuclear Information System (INIS)

    Abdullah, M N A; Das, S K; Tariq, A S B; Mahbub, M S; Mondal, A S; Uddin, M A; Basak, A K; Gupta, H M Sen; Malik, F B

    2003-01-01

    The differential cross-section of the 27 Al(α, t) 28 Si reaction for 64.5 MeV incident energy has been reanalysed in DWBA with full finite range using a squared Woods-Saxon (Michel) α-nucleus potential with the modified value of the depth parameter α = 2.0 as reported in a comment article by Michel and Reidemeister. This new value produces significant improvement in fitting the data of the reaction with its overall performance, in some cases, close to that previously observed for the molecular potential. Although the non-monotonic shallow molecular potential with a soft repulsive core and the Michel potentials produce the same quality fits to the elastic scattering and non-elastic processes, they are not phase equivalent. The two types of potential produce altogether different cross-sections, particularly at large reaction angles. The importance of the experimental cross-sections at large angles for both elastic scattering and non-elastic processes is elucidated

  12. Interaction with extracellular matrix proteins influences Lsh/Ity/Bcg (candidate Nramp) gene regulation of macrophage priming/activation for tumour necrosis factor-alpha and nitrite release.

    Science.gov (United States)

    Formica, S; Roach, T I; Blackwell, J M

    1994-05-01

    The murine resistance gene Lsh/Ity/Bcg regulates activation of macrophages for tumour necrosis factor-alpha (TNF-alpha)-dependent production of nitric oxide mediating antimicrobial activity against Leishmania, Salmonella and Mycobacterium. As Lsh is differentially expressed in macrophages from different tissue sites, experiments were performed to determine whether interaction with extracellular matrix (ECM) proteins would influence the macrophage TNF-alpha response. Plating of bone marrow-derived macrophages onto purified fibrinogen or fibronectin-rich L929 cell-derived matrices, but not onto mannan, was itself sufficient to stimulate TNF-alpha release, with significantly higher levels released from congenic B10.L-Lshr compared to C57BL/10ScSn (Lshs) macrophages. Only macrophages plated onto fibrinogen also released measurable levels of nitrites, again higher in Lshr compared to Lshs macrophages. Addition of interferon-gamma (IFN-gamma), but not bacterial lipopolysaccharide or mycobacterial lipoarabinomannan, as a second signal enhanced the TNF-alpha and nitrite responses of macrophages plated onto fibrinogen, particularly in the Lshr macrophages. Interaction with fibrinogen and fibronectin also primed macrophages for an enhanced TNF-alpha response to leishmanial parasites, but this was only translated into enhanced nitrite responses in the presence of IFN-gamma. In these experiments, Lshr macrophages remained superior in their TNF-alpha responses throughout, but to a degree which reflected the magnitude of the difference observed on ECM alone. Hence, the specificity for the enhanced TNF-alpha responses of Lshr macrophages lay in their interaction with fibrinogen and fibronectin ECM, while a differential nitrite response was only observed with fibrinogen and/or IFN-gamma. The results are discussed in relation to the possible function of the recently cloned candidate gene Nramp, which has structural identity to eukaryote transporters and an N-terminal cytoplasmic

  13. 3-[2,4-Dimethoxybenzylidene]anabaseine (DMXB) selectively activates rat alpha7 receptors and improves memory-related behaviors in a mecamylamine-sensitive manner.

    Science.gov (United States)

    Meyer, E M; Tay, E T; Papke, R L; Meyers, C; Huang, G L; de Fiebre, C M

    1997-09-12

    The alpha7 nicotinic receptor agonist 3-[2,4-dimethoxybenzylidene]anabaseine (DMXB; GTS-21) was investigated for its ability to: (1) activate a variety of nicotinic receptor subtypes in Xenopus oocytes; (2) improve passive avoidance and spatial Morris water task performances in mecamylamine-sensitive manners in bilaterally nucleus basalis lesioned rats; and (3) elevate high-affinity [3H]acetylcholine (ACh) and high-affinity alpha-[125I]bungarotoxin binding in rat neocortex following 2 weeks of daily injections. DMXB (100 microM) activated alpha7 homo-oligomeric receptors, without significant activity at alpha2-, alpha3- and alpha4-containing subtypes. Mecamylamine blocked rat alpha7 receptors weakly if co-administered with agonist, but much more potently when pre-applied. Bilateral ibotenic acid lesions of the nucleus basalis interfered with passive avoidance and spatial memory-related behaviors. DMXB (0.5 mg/kg, i.p.) improved passive avoidance behavior in lesioned animals in a mecamylamine-sensitive manner. DMXB (0.5 mg/kg 15 min before each session) also improved performance in the training and probe components of the Morris water task. DMXB-induced improvement in the probe component but not the training phase was mecamylamine-sensitive. [3H]ACh binding was elevated after 14 days of daily i.p. injections with 0.2 mg/kg nicotine but not after 1 mg/kg DMXB. Neither drug elevated high-affinity alpha-[125I]bungarorotoxin binding over this interval.

  14. FENDL/E-2.0. Evaluated nuclear data library of neutron-nucleus interaction cross sections and photon production cross sections and photon-atom interaction cross sections for fusion applications. Version 1, March 1997. Summary documentation

    International Nuclear Information System (INIS)

    Pashchenko, A.B.; Wienke, H.

    1998-01-01

    This document presents the description of a physical tape containing the basic evaluated nuclear data library of neutron-nucleus interaction cross sections, photon production cross sections and photon-atom interaction cross sections for fusion applications. It is part of the evaluated nuclear data library for fusion applications FENDL-2. The data are available cost-free from the Nuclear Data Section upon request. The data can also be retrieved by the user via online access through international computer networks. (author)

  15. Investigation of the alpha cluster model and the density matrix expansion in ion-ion collision

    International Nuclear Information System (INIS)

    Rashdan, M.B.M.

    1986-01-01

    This thesis deals with the investigation of the alpha cluster model (ACM) of brink and studies of the accuracy of the density matrix expansion (DME) approximation in deriving the real part of the ion-ion optical potential. the ACM is applied to calculate the inelastic 0 1 + →2 1 + charge form factor for electron scattering by 12 C to investigate the validity of this model for 12 C nucleus. it is found that the experimental curve can be fitted over the entire range of the momentum transfer by a generator - coordinate state for the 2 1 + state that consist of a superposition of two triangular ACM states with two different cluster separations and the same oscillator parameter

  16. The innate immunity adaptor SARM translocates to the nucleus to stabilize lamins and prevent DNA fragmentation in response to pro-apoptotic signaling.

    Directory of Open Access Journals (Sweden)

    Chad R Sethman

    Full Text Available Sterile alpha and armadillo-motif containing protein (SARM, a highly conserved and structurally unique member of the MyD88 family of Toll-like receptor adaptors, plays an important role in innate immunity signaling and apoptosis. Its exact mechanism of intracellular action remains unclear. Apoptosis is an ancient and ubiquitous process of programmed cell death that results in disruption of the nuclear lamina and, ultimately, dismantling of the nucleus. In addition to supporting the nuclear membrane, lamins serve important roles in chromatin organization, epigenetic regulation, transcription, nuclear transport, and mitosis. Mutations and other damage that destabilize nuclear lamins (laminopathies underlie a number of intractable human diseases. Here, we report that SARM translocates to the nucleus of human embryonic kidney cells by using its amino-terminal Armadillo repeat region. Within the nucleus, SARM forms a previously unreported lattice akin to the nuclear lamina scaffold. Moreover, we show that SARM protects lamins from apoptotic degradation and reduces internucleosomal DNA fragmentation in response to signaling induced by the proinflammatory cytokine Tumor Necrosis Factor alpha. These findings indicate an important link between the innate immunity adaptor SARM and stabilization of nuclear lamins during inflammation-driven apoptosis in human cells.

  17. Neutrino-Nucleus Interactions and the Short-Range Structure of Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Cavanna, F. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Palamara, O. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Schiavilla, R. [Old Dominion Univ., Norfolk, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Soderberg, M. [Syracuse Univ., NY (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Wiringa, R. B. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-01-08

    Improvements in theoretical modeling of Short Range structures and phenomena, and comparisons with data, will require sustained collaboration between nuclear theorists and neutrino experimentalists. The extensive history of studying this area of nuclear physics in electron- and hadron-scattering experiments, coupled with the transformative capabilities of LArTPCs to identify neutrinos, will provide a ripe opportunity for new discoveries that will further our understanding of the nucleus.

  18. EMMPRIN promotes melanoma cells malignant properties through a HIF-2alpha mediated up-regulation of VEGF-receptor-2.

    Directory of Open Access Journals (Sweden)

    Faten Bougatef

    Full Text Available EMMPRIN's expression in melanoma tissue was reported to be predictive of poor prognosis. Here we demonstrate that EMMPRIN up-regulated VEGF receptor-2 (VEGFR-2 in two different primary melanoma cell lines and consequently increased migration and proliferation of these cells while inhibiting their apoptosis. SiRNA inhibition of VEGFR-2 expression abrogated these EMMPRIN effects. EMMPRIN regulation of VEGFR-2 was mediated through the over-expression of HIF-2alpha and its translocation to the nucleus where it forms heterodimers with HIF-1beta. These results were supported by an in vivo correlation between the expression of EMMPRIN with that of VEGFR-2 in human melanoma tissues as well as with the extent of HIF-2alpha localization in the nucleus. They demonstrate a novel mechanism by which EMMPRIN promotes tumor progression through HIF-2alpha/VEGFR-2 mediated mechanism, with an autocrine role in melanoma cell malignancy. The inhibition of EMMPRIN in cancer may thus simultaneously target both the VEGFR-2/VEGF system and the matrix degrading proteases to block tumor cell growth and invasion.

  19. Factorization of secondary particle multiplicities in nucleus-nucleus collisions at energy of some GeV on the projectile nucleon; Faktorizatsiya mnozhestvennostej vtorichnykh chastits v yadro-yadernykh soudareniyakh pri ehnergii neskol`ko GehV na nuklon snaryada

    Energy Technology Data Exchange (ETDEWEB)

    Basova, E S; Zhumanov, A; Nasrullaeva, Kh; Nasyrov, Sk Z; Petrov, N V; Sadykov, N O; Svechnikova, L N; Trofimova, T P; Tuleeva, U I; Tursunov, B P

    1992-03-01

    The nuclear photographic emulsion method was used to study multiplicity of secondaries in interaction of some GeV on nucleon of {sup 132} Xe nucleus with photoemulsion. The formulas suggested describing the experimental data of normalized, mean and specific secondary particle multiplicity in nucleus-nucleus collisions at given energy. These formulas have evidence for the factorization of mean and specific multiplicities relatively the target and projectile nucleus mass number. (author). 10 refs., 5 figs., 4 tabs.

  20. Onuf's nucleus X

    DEFF Research Database (Denmark)

    Schrøder, H D

    1981-01-01

    in the length of the nucleus was observed. Based on the cytoarchitecture the nucleus could be divided in three parts, a cranial, a dorsomedial and a ventrolateral. All parts of the nucleus consisted of chromatin-rich medium-sized neurons, and apparent direct appositions between different cells bodies as well...

  1. M2-9 - a planetary nebula with an eruptive nucleus?

    International Nuclear Information System (INIS)

    Balick, B.

    1989-01-01

    M2-9 is a striking bipolar, or butterfly, planetary nebula (PN) whose nuclear spectrum is uncharacteristic of PN nuclei. Narrow lines ranging in ionization from O I, Fe II, forbidden Fe II, and Si II through forbidden O III are observed in the stellar spectrum. The H-alpha emission line has wings extending nearly 11,000 km/s at the base, and there is a deep self-absorption feature near the H-alpha line peak at the same velocity as nebular gas observed in one of the two bipolar lobes. The spectrum of M2-9's nucleus is more similar to the slow nova RR Tel, some symbiotic stars, and Seyfert (type 1.9) galactic nuclei than the central stars of most other PNs. Although its morphology, size, and nebular spectrum share many similarities with other PNs, M2-9 may not share a common evolutionary history with that class of objects. 31 references

  2. /sup 56/Fe (. gamma. ,. cap alpha. /sub 0/) reaction

    Energy Technology Data Exchange (ETDEWEB)

    Tamae, T; Sugawara, M [Tohoku Univ., Sendai (Japan). Lab. of Nuclear Science; Tsubota, H

    1974-12-01

    The reaction cross section of /sup 56/Fe (..gamma.., ..cap alpha../sub 0/) was measured from the electron energy of 15 to 25 MeV. The measured data were compared with the calculated ones based on statistic theory. Both agreed with each other. Therefore, the affirmative result was obtained for the presumption that the reaction of (..gamma.., ..cap alpha../sub 0/) of the nuclei around these energy levels can be explained by the statistical theory. The angular distribution of /sup 56/Fe (..gamma.., ..cap alpha../sub 0/) with 17 MeV electron energy was also measured, and the E2/E1 ratio was obtained. In the measurement of the /sup 56/Fe ( Gamma , ..cap alpha../sub 0/) reaction cross section, a natural target of 2.69 mg/cm/sup 2/ was irradiated with an electron beam with energy from 15 MeV to 25 MeV at intervals of 0.5 MeV, and the emitted ..cap alpha.. particles were detected by a broad band magnetic distribution meter. The measured cross section of the (..gamma.., ..cap alpha../sub 0/) reaction agreed with the calculated one based on statistical theory. If this fact is recognized in many nuclei, the cross section of the (..gamma.., ..cap alpha../sub 0/) reaction on those nuclei has the following characteristics. When the increasing rate of the product of a complex nucleus formation cross section and ..cap alpha../sub 0/ penetration factor is larger than that of the sum of all penetration factors of possible channels, the cross section of the (..gamma.., ..cap alpha../sub 0/) reaction increases, and takes a peak value when the above two increasing rates agree with each other.

  3. Evaluation of GABAergic neuroactive steroid 3alpha-hydroxy-5alpha-pregnane-20-one as a neurobiological substrate for the anti-anxiety effect of ethanol in rats.

    Science.gov (United States)

    Hirani, Khemraj; Sharma, Ajay N; Jain, Nishant S; Ugale, Rajesh R; Chopde, Chandrabhan T

    2005-07-01

    Acute systemic ethanol administration is known to elevate plasma and cerebral levels of neuroactive steroid 3alpha-hydroxy-5alpha-pregnane-20-one (3alpha, 5alpha-THP; allopregnanolone) to a concentration sufficient to potentiate GABA(A) receptors. We have earlier demonstrated that 3alpha, 5alpha-THP mediates the antidepressant-like effect of ethanol in Porsolt forced swim test. The aim of the present study is to explain the relationship between endogenous GABAergic neurosteroids and anxiolytic effect of ethanol in Sprague-Dawley rats. The mediation of 3alpha, 5alpha-THP in the anti-anxiety effect of ethanol was assessed by pharmacological interactions of ethanol with various endogenous neurosteroidal modulators and using simulated physiological conditions of altered neurosteroid content in elevated plus maze (EPM) test. Pretreatment of 3alpha, 5alpha-THP (0.5-2.5 mug/rat, i.c.v.) or neurosteroidogenic agents such as 3alpha, 5alpha-THP precursor progesterone (5 or 10 mg/kg, i.p.), 11-beta hydroxylase inhibitor metyrapone (50 or 100 mg/kg, i.p.) or the GABA(A) receptor agonist muscimol (25 ng/rat, i.c.v.) significantly potentiated the anti-anxiety effect of ethanol (1 g/kg, i.p.). On the other hand, the GABAergic antagonistic neurosteroid dehydroepiandrosterone sulphate (DHEAS) (1 mg/kg, i.p.), the GABA(A) receptor blocker bicuculline (1 mg/kg, i.p.), the 5alpha-reductase inhibitor finasteride (50 x 2 mg/kg, s.c.) or the mitochondrial diazepam binding inhibitory receptor antagonist PK11195 (1 mg/kg, i.p.) reduced ethanol-induced preference of time spent and number of entries into open arms. Anti-anxiety effect of ethanol was abolished in adrenalectomized (ADX) rats as compared to sham-operated control. This ADX-induced blockade was restored by prior systemic injection of progesterone, signifying the contribution of peripheral steroidogenesis in ethanol anxiolysis. Socially isolated animals known to exhibit decreased brain 3alpha, 5alpha-THP and GABA(A) receptor

  4. The spin-dependent neutralino-nucleus form factor for 127I

    International Nuclear Information System (INIS)

    Ressell, M.T.

    1996-01-01

    We present the results of detailed shell model calculations of the spin-dependent elastic form factor for the nucleus 127 I. the calculations were performed in extremely large model spaces which adequately describe the configuration mixing in this nucleus. Good agreement between the calculated and experimental values of the magnetic moment are found. Other nuclear observables are also compared to experiment. The dependence of the form factor upon the model space and effective interaction is discussed

  5. A hormone pulse induces transient changes in the subcellular distribution and leads to a lysosomal accumulation of the estradiol receptor alpha in target tissues.

    Science.gov (United States)

    Qualmann, B; Kessels, M M; Thole, H H; Sierralta, W D

    2000-06-01

    An intrauterine pulse-stimulation with estradiol induced changes in the subcellular localization of estrogen receptor alpha in porcine endometrium, as detected with F(ab') fragments of various anti-receptor antibodies covalently linked to nanogold. The low-sterically hindered immunoreagents--recognizing different epitopes within the hormone binding domain--allowed for an efficient immunolabeling of estradiol receptor alpha, detecting it both in the cytoplasm and the nucleus of nonstimulated epithelium cells. In the cytoplasm, the receptor often seemed to be associated with actin filaments and the endoplasmatic reticulum. After the stimulation with estradiol, a predominantly nuclear localization and a labeling of nucleoli was observed. Our immunoelectron microscopy study demonstrates a localization of the receptor in cytoplasmic organelles that increased after the hormone pulse. These organelles exhibited the morphological properties of lysosomes and relocated to the perinuclear area. In analogous cytoplasmic organelles, the presence of cathepsin D was detected via indirect immunogold labeling, justifying their classification as lysosomes. Quantitative examinations revealed that not only the number of lysosomes in the proximity of the nucleus but also their immunostaining for estradiol receptor alpha increased significantly after the hormone pulse. Thus, estradiol induces both the rapid shift of receptor into the nucleus, a slower perinuclear accumulation of lysosomes and an increase of lysosomal ERalpha-immunoreactivity. These results suggest a role for lysosomes in the degradation of receptor shuttling out of the nucleus. This could serve as termination of the estradiol receptor alpha-dependent activation of target cells. This hypothesis is strengthened by the fact that the receptor content in uterine tissue declined drastically few hours after the hormone pulse.

  6. Silk fibroin porous scaffolds for nucleus pulposus tissue engineering

    International Nuclear Information System (INIS)

    Zeng, Chao; Yang, Qiang; Zhu, Meifeng; Du, Lilong; Zhang, Jiamin; Ma, Xinlong; Xu, Baoshan; Wang, Lianyong

    2014-01-01

    Intervertebral discs (IVDs) are structurally complex tissue that hold the vertebrae together and provide mobility to spine. The nucleus pulposus (NP) degeneration often results in degenerative IVD disease that is one of the most common causes of back and neck pain. Tissue engineered nucleus pulposus offers an alternative approach to regain the function of the degenerative IVD. The aim of this study is to determine the feasibility of porous silk fibroin (SF) scaffolds fabricated by paraffin-sphere-leaching methods with freeze-drying in the application of nucleus pulposus regeneration. The prepared scaffold possessed high porosity of 92.38 ± 5.12% and pore size of 165.00 ± 8.25 μm as well as high pore interconnectivity and appropriate mechanical properties. Rabbit NP cells were seeded and cultured on the SF scaffolds. Scanning electron microscopy, histology, biochemical assays and mechanical tests revealed that the porous scaffolds could provide an appropriate microstructure and environment to support adhesion, proliferation and infiltration of NP cells in vitro as well as the generation of extracellular matrix. The NP cell–scaffold construction could be preliminarily formed after subcutaneously implanted in a nude mice model. In conclusion, The SF porous scaffold offers a potential candidate for tissue engineered NP tissue. - Highlights: • Paraffin microsphere-leaching method is used to fabricate silk fibroin scaffold. • The scaffold has appropriate mechanical property, porosity and pore size • The scaffold supports growth and infiltration of nucleus pulposus cells. • Nucleus pulposus cells can secrete extracellular matrix in the scaffolds. • The scaffold is a potential candidate for tissue engineered nucleus pulposus

  7. Silk fibroin porous scaffolds for nucleus pulposus tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Chao; Yang, Qiang [Department of Spine Surgery, Tianjin Hospital, Tianjin 300211 (China); Tianjin Medical University, Tianjin 300070 (China); Zhu, Meifeng [The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China); Du, Lilong [Department of Spine Surgery, Tianjin Hospital, Tianjin 300211 (China); Tianjin Medical University, Tianjin 300070 (China); Zhang, Jiamin [The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China); Ma, Xinlong [Department of Spine Surgery, Tianjin Hospital, Tianjin 300211 (China); Xu, Baoshan, E-mail: xubaoshan99@126.com [Department of Spine Surgery, Tianjin Hospital, Tianjin 300211 (China); Wang, Lianyong, E-mail: wly@nankai.edu.cn [The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China)

    2014-04-01

    Intervertebral discs (IVDs) are structurally complex tissue that hold the vertebrae together and provide mobility to spine. The nucleus pulposus (NP) degeneration often results in degenerative IVD disease that is one of the most common causes of back and neck pain. Tissue engineered nucleus pulposus offers an alternative approach to regain the function of the degenerative IVD. The aim of this study is to determine the feasibility of porous silk fibroin (SF) scaffolds fabricated by paraffin-sphere-leaching methods with freeze-drying in the application of nucleus pulposus regeneration. The prepared scaffold possessed high porosity of 92.38 ± 5.12% and pore size of 165.00 ± 8.25 μm as well as high pore interconnectivity and appropriate mechanical properties. Rabbit NP cells were seeded and cultured on the SF scaffolds. Scanning electron microscopy, histology, biochemical assays and mechanical tests revealed that the porous scaffolds could provide an appropriate microstructure and environment to support adhesion, proliferation and infiltration of NP cells in vitro as well as the generation of extracellular matrix. The NP cell–scaffold construction could be preliminarily formed after subcutaneously implanted in a nude mice model. In conclusion, The SF porous scaffold offers a potential candidate for tissue engineered NP tissue. - Highlights: • Paraffin microsphere-leaching method is used to fabricate silk fibroin scaffold. • The scaffold has appropriate mechanical property, porosity and pore size • The scaffold supports growth and infiltration of nucleus pulposus cells. • Nucleus pulposus cells can secrete extracellular matrix in the scaffolds. • The scaffold is a potential candidate for tissue engineered nucleus pulposus.

  8. K+ nucleus total cross section experiment and nuclear medium effects

    International Nuclear Information System (INIS)

    Weiss, Ruth.

    1992-11-01

    The low momentum K + is the weakest of the available strongly interacting particles. It has a mean bee path in nuclear matter of about 6 fm which makes it a good probe for studying properties of the nuclear interior. It allows one to build a good microscopic optical potential which can be used to calculate K + nucleus elastic and total cross sections. In the latter case the calculated ratio R T =[σ tot (K + A)/A]/[σ tot (K + d)/2] can be expected to be more reliable because some uncertainties in K + N phase shifts will cancel. This ratio can also be measured more reliably than the total cross sections themselves because of cancellation of some systematic errors. We measured the total cross sections of K + on D, 6 Li, 12 C, 28 Si and 40 Ca from 488 to 714 MeV/c. The emphasis was placed on extracting values of R T with a precision of better than 2 percent. The total cross section ratios are found to lie significantly above those predicted by optical potential calculations with the usual nuclear medium corrections. This suggests that novel phenomena are taking place within the nucleus. Several models which incorporate such phenomena are discussed, including nucleon 'swelling', mass rescaling, nuclear pions, and relativistic effects. (author) 31 refs., 27 figs., 21 tabs.,

  9. Dynamic Neural State Identification in Deep Brain Local Field Potentials of Neuropathic Pain.

    Science.gov (United States)

    Luo, Huichun; Huang, Yongzhi; Du, Xueying; Zhang, Yunpeng; Green, Alexander L; Aziz, Tipu Z; Wang, Shouyan

    2018-01-01

    In neuropathic pain, the neurophysiological and neuropathological function of the ventro-posterolateral nucleus of the thalamus (VPL) and the periventricular gray/periaqueductal gray area (PVAG) involves multiple frequency oscillations. Moreover, oscillations related to pain perception and modulation change dynamically over time. Fluctuations in these neural oscillations reflect the dynamic neural states of the nucleus. In this study, an approach to classifying the synchronization level was developed to dynamically identify the neural states. An oscillation extraction model based on windowed wavelet packet transform was designed to characterize the activity level of oscillations. The wavelet packet coefficients sparsely represented the activity level of theta and alpha oscillations in local field potentials (LFPs). Then, a state discrimination model was designed to calculate an adaptive threshold to determine the activity level of oscillations. Finally, the neural state was represented by the activity levels of both theta and alpha oscillations. The relationship between neural states and pain relief was further evaluated. The performance of the state identification approach achieved sensitivity and specificity beyond 80% in simulation signals. Neural states of the PVAG and VPL were dynamically identified from LFPs of neuropathic pain patients. The occurrence of neural states based on theta and alpha oscillations were correlated to the degree of pain relief by deep brain stimulation. In the PVAG LFPs, the occurrence of the state with high activity levels of theta oscillations independent of alpha and the state with low-level alpha and high-level theta oscillations were significantly correlated with pain relief by deep brain stimulation. This study provides a reliable approach to identifying the dynamic neural states in LFPs with a low signal-to-noise ratio by using sparse representation based on wavelet packet transform. Furthermore, it may advance closed-loop deep

  10. On the deep inelastic lepton-nucleus scattering

    International Nuclear Information System (INIS)

    Darbaidze, Ya.Z.; Garsevanishvili, V.R.; Menteshashvili, Z.R.

    1979-01-01

    Deep inelastic scattering of charged leptons on nuclei is considered in the lowest order in electromagnetic interaction. Expressions for the corresponding differential cross sections are obtained provided the scattered lepton and the fragment of the initial nucleus are detected in coincidence. Structure functions are analyzed by means of the automodelity principle. These functions are considered in the framework of the ''light front'' formalism for many-body systems. A hypothesis is put forward on the scale invariance of structure functions with respect to the xi-variable, which is some complicated dimensionless combination of kinematic invariants. A simple relation of this variable to the momenta of the nucleons inside the initial nucleus is pointed out

  11. Classifiers for centrality determination in proton-nucleus and nucleus-nucleus collisions

    Directory of Open Access Journals (Sweden)

    Altsybeev Igor

    2017-01-01

    Full Text Available Centrality, as a geometrical property of the collision, is crucial for the physical interpretation of nucleus-nucleus and proton-nucleus experimental data. However, it cannot be directly accessed in event-by-event data analysis. Common methods for centrality estimation in A-A and p-A collisions usually rely on a single detector (either on the signal in zero-degree calorimeters or on the multiplicity in some semi-central rapidity range. In the present work, we made an attempt to develop an approach for centrality determination that is based on machine-learning techniques and utilizes information from several detector subsystems simultaneously. Different event classifiers are suggested and evaluated for their selectivity power in terms of the number of nucleons-participants and the impact parameter of the collision. Finer centrality resolution may allow to reduce impact from so-called volume fluctuations on physical observables being studied in heavy-ion experiments like ALICE at the LHC and fixed target experiment NA61/SHINE on SPS.

  12. Adducin family proteins possess different nuclear export potentials.

    Science.gov (United States)

    Liu, Chia-Mei; Hsu, Wen-Hsin; Lin, Wan-Yi; Chen, Hong-Chen

    2017-05-10

    The adducin (ADD) family proteins, namely ADD1, ADD2, and ADD3, are actin-binding proteins that play important roles in the stabilization of membrane cytoskeleton and cell-cell junctions. All the ADD proteins contain a highly conserved bipartite nuclear localization signal (NLS) at the carboxyl termini, but only ADD1 can localize to the nucleus. The reason for this discrepancy is not clear. To avoid the potential effect of cell-cell junctions on the distribution of ADD proteins, HA epitope-tagged ADD proteins and mutants were transiently expressed in NIH3T3 fibroblasts and their distribution in the cytoplasm and nucleus was examined by immunofluorescence staining. Several nuclear proteins were identified to interact with ADD1 by mass spectrometry, which were further verified by co-immunoprecipitation. In this study, we found that ADD1 was detectable both in the cytoplasm and nucleus, whereas ADD2 and ADD3 were detected only in the cytoplasm. However, ADD2 and ADD3 were partially (~40%) sequestered in the nucleus by leptomycin B, a CRM1/exportin1 inhibitor. Upon the removal of leptomycin B, ADD2 and ADD3 re-distributed to the cytoplasm. These results indicate that ADD2 and ADD3 possess functional NLS and are quickly transported to the cytoplasm upon entering the nucleus. Indeed, we found that ADD2 and ADD3 possess much higher potential to counteract the activity of the NLS derived from Simian virus 40 large T-antigen than ADD1. All the ADD proteins appear to contain multiple nuclear export signals mainly in their head and neck domains. However, except for the leucine-rich motif ( 377 FEALMRMLDWLGYRT 391 ) in the neck domain of ADD1, no other classic nuclear export signal was identified in the ADD proteins. In addition, the nuclear retention of ADD1 facilitates its interaction with RNA polymerase II and zinc-finger protein 331. Our results suggest that ADD2 and ADD3 possess functional NLS and shuttle between the cytoplasm and nucleus. The discrepancy in the

  13. Interaction of the heterotrimeric G protein alpha subunit SSG-1 of Sporothrix schenckii with proteins related to stress response and fungal pathogenicity using a yeast two-hybrid assay

    Directory of Open Access Journals (Sweden)

    González-Méndez Ricardo

    2010-12-01

    Full Text Available Abstract Background Important biological processes require selective and orderly protein-protein interactions at every level of the signalling cascades. G proteins are a family of heterotrimeric GTPases that effect eukaryotic signal transduction through the coupling of cell surface receptors to cytoplasmic effector proteins. They have been associated with growth and pathogenicity in many fungi through gene knock-out studies. In Sporothrix schenckii, a pathogenic, dimorphic fungus, we previously identified a pertussis sensitive G alpha subunit, SSG-1. In this work we inquire into its interactions with other proteins. Results Using the yeast two-hybrid technique, we identified protein-protein interactions between SSG-1 and other important cellular proteins. The interactions were corroborated using co-immuneprecipitation. Using these techniques we identified a Fe/Mn superoxide dismutase (SOD, a glyceraldehyde-3-P dehydrogenase (GAPDH and two ion transport proteins, a siderophore-iron transporter belonging to the Major Facilitator Superfamily (MFS and a divalent-cation transporter of the Nramp (natural resistance-associated macrophage protein family as interacting with SSG-1. The cDNA's encoding these proteins were sequenced and bioinformatic macromolecular sequence analyses were used for the correct classification and functional assignment. Conclusions This study constitutes the first report of the interaction of a fungal G alpha inhibitory subunit with SOD, GAPDH, and two metal ion transporters. The identification of such important proteins as partners of a G alpha subunit in this fungus suggests possible mechanisms through which this G protein can affect pathogenicity and survival under conditions of environmental stress or inside the human host. The two ion transporters identified in this work are the first to be reported in S. schenckii and the first time they are identified as interacting with fungal G protein alpha subunits. The association

  14. Adeno-associated virus (AAV-mediated suppression of Ca2+/calmodulin kinase IV activity in the nucleus accumbens modulates emotional behaviour in mice

    Directory of Open Access Journals (Sweden)

    Bading Hilmar

    2007-12-01

    Full Text Available Abstract Background Calcium/calmodulin-dependent protein kinase IV (CaMKIV controls activity-dependent gene transcription by regulating the activity of the cyclic AMP response element binding protein (CREB. This signaling pathway is involved in gating emotional responses in the CNS but previous studies did not address the potential roles of CaMKIV in discrete brain regions. In the present study, we aimed at specifically dissecting the role of CaMKIV in the nucleus accumbens of adult mice. Results We used recombinant adeno-associated virus (rAAV-mediated gene transfer of a dominant-negative CaMKIV variant (rAAV-dnCaMKIV to inhibit endogenous CaMKIV in the nucleus accumbens. rAAV-dnCaMKIV treated animals were subjected to a battery of tests including, prepulse inhibition of the acoustic startle response, open field, social interaction and anxiety-related behaviour. We found that basal locomotor activity in the open field, and prepulse inhibition or startle performance were unaltered in mice infected with rAAV-dnCaMKIV in the nucleus accumbens. However, anxiogenic effects were revealed in social interaction testing and the light/dark emergence test. Conclusion Our findings suggest a modulatory role of CaMKIV in the nucleus accumbens in anxiety-like behaviour but not sensorimotor gating.

  15. Neutrino-nucleus neutral current elastic interactions measurement in MiniBooNE

    Energy Technology Data Exchange (ETDEWEB)

    Perevalov, Denis [Univ. of Alabama, Tuscaloosa, AL (United States)

    2009-12-01

    The MiniBooNE experiment at the Fermi National Accelerator Laboratory (Fermilab) was designed to search for vμ → ve neutrino oscillations at Δm2 ~ 1 eV2 using an intense neutrino flux with an average energy Ev ~ 700 MeV. From 2002 to 2009 MiniBooNE has accumulated more than 1.0 x 1021 protons on target (POT) in both neutrino and antineutrino modes. MiniBooNE provides a perfect platform for detailed measurements of exclusive and semiinclusive neutrino cross-sections, for which MiniBooNE has the largest samples of events up to date, such as neutral current elastic (NCE), neutral current π0, charged current quasi-elastic (CCQE), charged current π+, and other channels. These measured cross-sections, in turn, allow to improve the knowledge of nucleon structure. This thesis is devoted to the study of NCE interactions. Neutrino-nucleus neutral current elastic scattering (vN → vN) accounts for about 18% of all neutrino interactions in MiniBooNE. Using a high-statistics, high purity sample of NCE interactions in MiniBooNE, the flux-averaged NCE differential cross-section has been measured and is being reported here. Further study of the NCE cross-section allowed for probing the structure of nuclei. The main interest in the NCE cross-section is that it may be sensitive to the strange quark contribution to the nucleon spin, Δs, this however requires a separation of NCE proton (vp → vp) from NCE neutron (vn → vn) events, which in general is a challenging task. MiniBooNE uses a Cherenkov detector, which imposes restrictions on the measured nucleon kinematic variables, mainly due to the impossibility to reconstruct the nucleon direction below the Cherenkov threshold. However, at kinetic energies above this threshold MiniBooNE is able to identify NCE proton events that do not experience final state interactions (FSI). These events were used for the Δs measurement. In this thesis

  16. Biophysical analysis of the dose-dependent overdispersion and the restricted linear energy transfer dependence expressed in dicentric chromosome data from alpha-irradiated human lymphocytes.

    Science.gov (United States)

    Greinert, R; Harder, D

    1997-06-01

    Experimental data for the induction of dicentric chromosomes in phytohemagglutinin (PHA)-stimulated human T lymphocytes by 241Am alpha-particles obtained by Schmid et al. have been analyzed in the light of biophysical theory. As usual in experiments with alpha-particles, the relative variance of the intercellular distribution of the number of aberrations per cell exceeds unity, and the multiplicity of the aberrations per particle traversal through the cell is understood as the basic effect causing this overdispersion. However, the clearly expressed dose dependence of the relative variance differs from the dose-independent relative variance predicted by the multiplicity effect alone. Since such dose dependence is often observed in experiments with alpha-particles, protons, and high-energy neutrons, the interpretation of the overdispersion needs to be supplemented. In a new, more general statistical model, the distribution function of the number of aberrations is interpreted as resulting from the convolution of a Poisson distribution for the spontaneous aberrations with the overdispersed distributions for the aberrations caused by intratrack or intertrack lesion interaction, and the fluctuation of the cross-sectional area of the cellular chromatin must also be considered. Using a suitable mathematical formulation of the resulting dose-dependent over-dispersion, the mean number lambda 1 of the aberrations produced by a single particle traversal through the cell nucleus and the mean number lambda 2 of the aberrations per pairwise approach between two alpha-particle tracks could be estimated. Coefficient alpha of the dose-proportional yield component, when compared between 241Am alpha-particle irradiation and 137Cs gamma-ray exposure, is found to increase approximately in proportion to dose-mean restricted linear energy transfer, which indicates an underlying pairwise molecular lesion interaction on the nanometer scale.

  17. Calculation of Rydberg interaction potentials

    International Nuclear Information System (INIS)

    Weber, Sebastian; Büchler, Hans Peter; Tresp, Christoph; Urvoy, Alban; Hofferberth, Sebastian; Menke, Henri; Firstenberg, Ofer

    2017-01-01

    The strong interaction between individual Rydberg atoms provides a powerful tool exploited in an ever-growing range of applications in quantum information science, quantum simulation and ultracold chemistry. One hallmark of the Rydberg interaction is that both its strength and angular dependence can be fine-tuned with great flexibility by choosing appropriate Rydberg states and applying external electric and magnetic fields. More and more experiments are probing this interaction at short atomic distances or with such high precision that perturbative calculations as well as restrictions to the leading dipole–dipole interaction term are no longer sufficient. In this tutorial, we review all relevant aspects of the full calculation of Rydberg interaction potentials. We discuss the derivation of the interaction Hamiltonian from the electrostatic multipole expansion, numerical and analytical methods for calculating the required electric multipole moments and the inclusion of electromagnetic fields with arbitrary direction. We focus specifically on symmetry arguments and selection rules, which greatly reduce the size of the Hamiltonian matrix, enabling the direct diagonalization of the Hamiltonian up to higher multipole orders on a desktop computer. Finally, we present example calculations showing the relevance of the full interaction calculation to current experiments. Our software for calculating Rydberg potentials including all features discussed in this tutorial is available as open source. (tutorial)

  18. Simulated nucleon–nucleon and nucleon–nucleus reactions in the ...

    Indian Academy of Sciences (India)

    In this study, we have used quantum molecular dynamic (QMD) as a theoretical model to ... Nuclear reactions; quantum dynamics; cascade exciton model. ... particle incident on a nucleus will interact with individual nucleons, with the final ...

  19. Lateral hypothalamus, nucleus accumbens, and ventral pallidum roles in eating and hunger: interactions between homeostatic and reward circuitry

    Directory of Open Access Journals (Sweden)

    Daniel Charles Castro

    2015-06-01

    Full Text Available The study of the neural bases of eating behavior, hunger, and reward has consistently implicated the lateral hypothalamus (LH and its interactions with mesocorticolimbic circuitry, such as mesolimbic dopamine projections to nucleus accumbens (NAc and ventral pallidum (VP, in controlling motivation to eat. The NAc and VP play special roles in mediating the hedonic impact (‘liking’ and motivational incentive salience (‘wanting’ of food rewards, and their interactions with LH help permit regulatory hunger/satiety modulation of food motivation and reward. Here, we review some progress that has been made regarding this circuitry and its functions: the identification of localized anatomical hedonic hotspots within NAc and VP for enhancing hedonic impact; interactions of NAc/VP hedonic hotspots with specific LH signals such as orexin; an anterior-posterior gradient of sites in NAc shell for producing intense appetitive eating versus intense fearful reactions; and anatomically distributed appetitive functions of dopamine and mu opioid signals in NAc shell and related structures. Such findings help improve our understanding of NAc, VP, and LH interactions in mediating affective and motivation functions, including ‘liking’ and ‘wanting’ for food rewards.

  20. Inclusive proton spectra and total reaction cross sections for proton-nucleus scattering at 800 MeV

    International Nuclear Information System (INIS)

    McGill, J.A.

    1981-08-01

    Current applications of multiple scattering theory to describe the elastic scattering of medium energy protons from nuclei have been shown to be quite successful in reproducing the experimental cross sections. These calculations use the impulse approximation, wherein the scattering from individual nucleons in the nucleus is described by the scattering amplitude for a free nucleon. Such an approximation restricts the inelastic channels to those initiated by nucleon-nucleon scattering. As a first step in determining the nature of p + nucleus scattering at 800 MeV, both total reaction cross sections and (p,p') inclusive cross sections were measured and compared to the free p + p cross sections for hydrogen, deuterium, calcium 40, carbon 12, and lead 208. It is concluded that as much as 85% of all reactions in a nucleus proceed from interactions with a single nucleon in the nucleus, and that the impulse approximation is a good starting point for a microscopic description of p + nucleus interactions at 800 MeV

  1. Normative findings of electrically evoked compound action potential measurements using the neural response telemetry of the Nucleus CI24M cochlear implant system.

    NARCIS (Netherlands)

    Cafarelli-Dees, D.; Dillier, N.; Lai, W.K.; Wallenberg, E. von; Dijk, B. van; Akdas, F.; Aksit, M.; Batman, C.; Beynon, A.J.; Burdo, S.; Chanal, J.M.; Collet, L.; Conway, M.; Coudert, C.; Craddock, L.; Cullington, H.; Deggouj, N.; Fraysse, B.; Grabel, S.; Kiefer, J.; Kiss, J.G.; Lenarz, T.; Mair, A.; Maune, S.; Muller-Deile, J.; Piron, J.P.; Razza, S.; Tasche, C.; Thai-Van, H.; Toth, F.; Truy, E.; Uziel, A.; Smoorenburg, G.F.

    2005-01-01

    One hundred and forty-seven adult recipients of the Nucleus 24 cochlear implant system, from 13 different European countries, were tested using neural response telemetry to measure the electrically evoked compound action potential (ECAP), according to a standardised postoperative measurement

  2. CASTOR A Forward Detector for the Identification of Centauro and Strangelets in Nucleus-Nucleus Collisions at the LHC

    CERN Document Server

    Angelis, Aris L S; Bogolyubsky, M Yu; Filippov, S N; Gladysz-Dziadus, E; Kharlov, Yu V; Kurepin, A B; Maevskaya, A I; Mavromanolakis, G; Panagiotou, A D; Sadovsky, S A; Stefanski, P; Wlodarczyk, Z

    2000-01-01

    Presentation made at the XXVIIIth Symposium on Multiparticle Dynamics, 6-11 September 1998, Delphi and published in World ScientificThe physics motivation for a very forward detector to be employed in heavy ion collisions at the CERN LHC is discussed. A phenomenological model describing the formation and decay of a Centauro fireball in nucleus-nucleus collisions is presented. The CASTOR detector which is aimed to measure the hadronic and photonic content of an interaction and to identify deeply penetrating objects in the very forward, baryon-rich phase space 5.6eta7.2 in an event-by-event mode is described. Results of simulations of the expected response of the calorimeter and, in particular, to the passage of strangelets, are presented.

  3. Microscopic calculations of elastic scattering between light nuclei based on a realistic nuclear interaction

    Energy Technology Data Exchange (ETDEWEB)

    Dohet-Eraly, Jeremy [F.R.S.-FNRS (Belgium); Sparenberg, Jean-Marc; Baye, Daniel, E-mail: jdoheter@ulb.ac.be, E-mail: jmspar@ulb.ac.be, E-mail: dbaye@ulb.ac.be [Physique Nucleaire et Physique Quantique, CP229, Universite Libre de Bruxelles (ULB), B-1050 Brussels (Belgium)

    2011-09-16

    The elastic phase shifts for the {alpha} + {alpha} and {alpha} + {sup 3}He collisions are calculated in a cluster approach by the Generator Coordinate Method coupled with the Microscopic R-matrix Method. Two interactions are derived from the realistic Argonne potentials AV8' and AV18 with the Unitary Correlation Operator Method. With a specific adjustment of correlations on the {alpha} + {alpha} collision, the phase shifts for the {alpha} + {alpha} and {alpha} + {sup 3}He collisions agree rather well with experimental data.

  4. Systematic Proteomic Identification of the Heat Shock Proteins (Hsp) that Interact with Estrogen Receptor Alpha (ERα) and Biochemical Characterization of the ERα-Hsp70 Interaction.

    Science.gov (United States)

    Dhamad, Ahmed E; Zhou, Zhenqi; Zhou, Jianhong; Du, Yuchun

    2016-01-01

    Heat shock proteins (Hsps) are known to associate with estrogen receptors (ER) and regulate ER-mediated cell proliferation. Historically, the studies in this area have focused on Hsp90. However, some critical aspects of the Hsp-ERα interactions remain unclear. For example, we do not know which Hsps are the major or minor ERα interactants and whether or not different Hsp isoforms associate equally with ERα. In the present study, through a quantitative proteomic method we found that 21 Hsps and 3 Hsp cochaperones were associated with ERα in human 293T cells that were cultured in a medium containing necessary elements for cell proliferation. Four Hsp70s (Hsp70-1, Hsc70, Grp75, and Grp78) were the most abundant Hsps identified to associate with ERα, followed by two Hsp90s (Hsp90α and Hsp90β) and three Hsp110s (Hsp105, HspA4, and HspA4L). Hsp90α was found to be 2-3 times more abundant than Hsp90β in the ERα-containing complexes. Among the reported Hsp cochaperones, we detected prostaglandin E synthase 3 (p23), peptidyl-prolyl cis-trans isomerase FKBP5 (FKBP51), and E3 ubiquitin-protein ligase CHIP (CHIP). Studies with the two most abundant ERα-associated Hsps, Hsp70-1 and Hsc70, using human breast cancer MCF7 cells demonstrate that the two Hsps interacted with ERα in both the cytoplasm and nucleus when the cells were cultured in a medium supplemented with fetal bovine serum and phenol red. Interestingly, the ERα-Hsp70-1/Hsc70 interactions were detected only in the cytoplasm but not in the nucleus under hormone starvation conditions, and stimulation of the starved cells with 17β-estradiol (E2) did not change this. In addition, E2-treatment weakened the ERα-Hsc70 interaction but had no effect on the ERα-Hsp70-1 interaction. Further studies showed that significant portions of Hsp70-1 and Hsc70 were associated with transcriptionally active chromatin and inactive chromatin, and the two Hsps interacted with ERα in both forms of the chromatins in MCF7 cells.

  5. Proton-Nucleus Collisions at the LHC: Scientific Opportunities and Requirements

    CERN Document Server

    Salgado, C A; Arleo, F; Armesto, N; Botje, M; Cacciari, M; Campbell, J; Carli, C; Cole, B; D'Enterria, D; Gelis, F; Guzey, V; Hencken, K; Jacobs, P; Jowett, J M; Klein, S R; Maltoni, F; Morsch, A; Piotrzkowski, K; Qiu, J W; Satogata, T; Sikler, F; Strikman, M; Takai, H; Vogt, R; Wessels, J P; White, S N; Wiedemann, U A; Wyslouch, B; Zhalov, M

    2012-01-01

    Proton-nucleus (p+A) collisions have long been recognized as a crucial component of the physics programme with nuclear beams at high energies, in particular for their reference role to interpret and understand nucleus-nucleus data as well as for their potential to elucidate the partonic structure of matter at low parton fractional momenta (small-x). Here, we summarize the main motivations that make a proton-nucleus run a decisive ingredient for a successful heavy-ion programme at the Large Hadron Collider (LHC) and we present unique scientific opportunities arising from these collisions. We also review the status of ongoing discussions about operation plans for the p+A mode at the LHC.

  6. Alpha particle physics experiments in the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Zweben, S.J.; Budny, R.V.; Darrow, D.S.; Medley, S.S.; Nazikian, R.; Stratton, B.C.; Synakowski, E.J.; Taylor, G.

    2000-01-01

    Alpha particle physics experiments were done on TFTR during its DT run from 1993 to 1997. These experiments utilized several new alpha particle diagnostics and hundreds of DT discharges to characterize the alpha particle confinement and wave-particle interactions. In general, the results from the alpha particle diagnostics agreed with the classical single particle confinement model in MHD quiescent discharges. The alpha loss due to toroidal field ripple was identified in some cases, and the low radial diffusivity inferred for high energy alphas was consistent with orbit averaging over small scale turbulence. Finally, the observed alpha particle interactions with sawteeth, toroidal Alfven eigenmodes and ICRF waves were approximately consistent with theoretical modelling. What was learned is reviewed and what remains to be understood is identified. (author)

  7. Alpha Shapes and Proteins

    DEFF Research Database (Denmark)

    Winter, Pawel; Sterner, Henrik; Sterner, Peter

    2009-01-01

    We provide a unified description of (weighted) alpha shapes, beta shapes and the corresponding simplicialcomplexes. We discuss their applicability to various protein-related problems. We also discuss filtrations of alpha shapes and touch upon related persistence issues.We claim that the full...... potential of alpha-shapes and related geometrical constructs in protein-related problems yet remains to be realized and verified. We suggest parallel algorithms for (weighted) alpha shapes, and we argue that future use of filtrations and kinetic variants for larger proteins will need such implementation....

  8. Weak and saturable protein-surfactant interactions in the denaturation of apo-alpha-lactalbumin by acidic and lactonic sophorolipid

    Directory of Open Access Journals (Sweden)

    Kell K Andersen

    2016-11-01

    Full Text Available Biosurfactants are of growing interest as sustainable alternatives to fossil-fuel-derived chemical surfactants, particularly for the detergent industry. To realize this potential, it is necessary to understand how they affect proteins which they may encounter in their applications. However knowledge of such interactions is limited. Here we present a study of the interactions between the model protein apo-alpha-lactalbumin and the biosurfactant sophorolipid (SL produced by the yeast Starmerella bombicola. SL occurs both as an acidic and a lactonic form; the lactonic form (lactSL is sparingly soluble and has a lower critical micelle concentration than the acidic form (acidSL. We show that acidSL affects apo-aLA in a similar way to the related glycolipid biosurfactant rhamnolipid (RL, with the important difference that RL is also active below the cmc in contrast to acidSL. Using isothermal titration calorimetry data, we show that acidSL has weak and saturable interactions with apo-aLA at low concentrations; due to the relatively low cmc of acidSL (which means that the monomer concentration is limited to ca. 0-1 mM SL, it is only possible to observe interactions with monomeric acidSL at high apo-aLA concentrations. However, the denaturation kinetics of apo-aLA in the presence of acidSL are consistent with a collaboration between monomeric and micellar surfactant species, similar to RL and nonionic or zwitterionic surfactants. Inclusion of lactSL as mixed micelles with acidSL lowers the cmc and this effectively reduces the rate of unfolding, emphasizing that SL like other biosurfactants is a gentle anionic surfactant. Our data highlight the potential of these biosurfactants for future use in the detergent industry.

  9. An effective potential for electron-nucleus scattering in neutrino-pair bremsstrahlung in neutron star crust

    International Nuclear Information System (INIS)

    Ofengeim, D D; Kaminker, A D; Yakovlev, D G

    2015-01-01

    We derive an analytic approximation for the emissivity of neutrino-pair bremsstrahlung (NPB) due to scattering of electrons by atomic nuclei in a neutron star (NS) crust of any realistic composition. The emissivity is expressed through generalized Coulomb logarithm by introducing an effective potential of electron-nucleus scattering. In addition, we study the conditions at which NPB in the crust is affected by strong magnetic fields and outline the main effects of the fields on neutrino emission in NSs. The results can be used for modelling of many phenomena in NSs, such as cooling of young isolated NSs, thermal relaxation of accreting NSs with overheated crust in soft X-ray transients and evolution of magnetars. (paper)

  10. Identification of amino acids involved in histamine potentiation of GABA(A receptors

    Directory of Open Access Journals (Sweden)

    Ulrike eThiel

    2015-05-01

    Full Text Available Histamine is a neurotransmitter involved in a number of physiological and neuronal functions. In mammals, such as humans and rodents, the histaminergic neurons found in the tuberomamillary nucleus (TMN project widely throughout the central nervous system (CNS. Histamine acts as positive modulator of GABA(A receptors (GABA(ARs and, in high concentrations (10 mM, as negative modulator of the strychnine-sensitive glycine receptor. However, the exact molecular mechanisms by which histamine acts on GABA(ARs are unknown. In our study, we aimed to identify amino acids potentially involved in the modulatory effect of histamine on GABA(ARs. We expressed GABA(ARs with 12 different point mutations in Xenopus laevis oocytes and characterized the effect of histamine on GABA-induced currents using the two-electrode voltage clamp technique. Our data demonstrate that the amino acid residues ß2(N265 and ß2(M286, which are important for modulation by propofol, are not involved in the action of histamine. However, we found that histamine modulation is dependent on the amino acid residues alpha1(R120, ß2(Y157, ß3(D163, ß3(V175 and ß3(Q185. We showed that the amino acid residues ß2(Y157 and ß3(Q185 mediate the positive modulatory effect of histamine on GABA-induced currents, whereas alpha1(R120 and ß2(D163 form a potential histamine interaction site in GABA(ARs.

  11. Germanium cryogenic detectors: Alpha surface events rejection capabilities

    International Nuclear Information System (INIS)

    Fiorucci, S.; Broniatowski, A.; Chardin, G.; Censier, B.; Lesquen, A. de; Deschamps, H.; Fesquet, M.; Jin, Y.

    2006-01-01

    Alpha surface events and multiple compton gamma interactions are the two major background components in Ge detectors for double-beta decay investigations. Two different methods have been studied to identify such type of events, using cryogenic Ge detectors developed primarily for dark matter search: (i) combined heat and ionization measurements, and (ii) pulse-shape analysis of the charge collection signals. Both methods show strong separation between electron recoil events and surface alphas. Cryogenic heat-ionization detectors therefore appear able to reject virtually all surface alpha interactions

  12. Angular distributions of nucleons emitted in high energy hadron-nucleus collisions

    International Nuclear Information System (INIS)

    Strugalski, Z.

    1983-01-01

    Angular distributions of ''fast'' protons, of kinetic energy from about 20 to about 400 MeV, emitted in pion-xenon nucleus collisions at 3.5 GeV/c momentum were studied in two groups of events - when particles are produced and when particle production does not occur. The distributions are practically the same in both the groups of events and in subgroups of events with various multiplicities of emitted protons. Comparison of angular distributions of protons emitted in pion-xenon nucleus collisions at 3.5 GeV/c momentum with corresponding angular distributions of protons emitted in proton-emulsion collisions at 300-400 GeV/c momentum is performed. Results obtained allow to conclude that average value of the nucleon emission angle and the nucleon angular distributions do not depend practically on the nuclear matter layer thickness the incident hadron collided with. Fast nucleons emitted from the target nucleus seem did not interact inside the parent nucleus. Fast nucleon angular distributions do not depend on the energy of incident hadron, they are the same for pion-nucleus and for proton-nucleus collisions as well

  13. Isospin symmetry violation, meson production and η-nucleus ...

    Indian Academy of Sciences (India)

    The experiment was perfomed at the cooler synchrotron accelerator. COSY, Jülich at several beam energies close to the corresponding production threshold. We also have ongoing programmes on -nucleus final-state interaction studies via + 6Li → 7Be + reactions, high resolution search for dibaryonic resonances ...

  14. Targeted Alpha Therapy: From Alpha to Omega

    International Nuclear Information System (INIS)

    Allen, Barry J; Clarke, Raymond; Huang Chenyu

    2013-01-01

    This review covers the broad spectrum of Targeted Alpha Therapy (TAT) research in Australia; from in vitro and in vivo studies to clinical trials. The principle of tumour anti-vascular alpha therapy (TAVAT) is discussed in terms of its validation by Monte Carlo calculations of vascular models and the potential role of biological dosimetry is examined. Summmary of this review is as follows: 1. The essence of TAT 2. Therapeutic objectives 3. TAVAT and Monte Carlo microdosimetry 4. Biological dosimetry 5. Preclinical studies 6. Clinical trials 7. What next? 8. Obstacles. (author)

  15. Potential late-onset Alzheimer's disease-associated mutations in the ADAM10 gene attenuate {alpha}-secretase activity.

    Science.gov (United States)

    Kim, Minji; Suh, Jaehong; Romano, Donna; Truong, Mimy H; Mullin, Kristina; Hooli, Basavaraj; Norton, David; Tesco, Giuseppina; Elliott, Kathy; Wagner, Steven L; Moir, Robert D; Becker, K David; Tanzi, Rudolph E

    2009-10-15

    ADAM10, a member of a disintegrin and metalloprotease family, is an alpha-secretase capable of anti-amyloidogenic proteolysis of the amyloid precursor protein. Here, we present evidence for genetic association of ADAM10 with Alzheimer's disease (AD) as well as two rare potentially disease-associated non-synonymous mutations, Q170H and R181G, in the ADAM10 prodomain. These mutations were found in 11 of 16 affected individuals (average onset age 69.5 years) from seven late-onset AD families. Each mutation was also found in one unaffected subject implying incomplete penetrance. Functionally, both mutations significantly attenuated alpha-secretase activity of ADAM10 (>70% decrease), and elevated Abeta levels (1.5-3.5-fold) in cell-based studies. In summary, we provide the first evidence of ADAM10 as a candidate AD susceptibility gene, and report two potentially pathogenic mutations with incomplete penetrance for late-onset familial AD.

  16. DISCOVERY OF AN H{alpha} EMITTING DISK AROUND THE SUPERMASSIVE BLACK HOLE OF M31

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, R. B.; Steiner, J. E.; Ricci, T. V., E-mail: robertobm@astro.iag.usp.br [Instituto de Astronomia Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Rua do Matao 1226, Cidade Universitaria, Sao Paulo, SP CEP 05508-090 (Brazil)

    2013-01-10

    Due to its proximity, the mass of the supermassive black hole in the nucleus of the Andromeda galaxy (M31), the most massive black hole in the Local Group of galaxies, has been measured by several methods involving the kinematics of a stellar disk which surrounds it. We report here the discovery of an eccentric H{alpha} emitting disk around the black hole at the center of M31 and show how modeling this disk can provide an independent determination of the mass of the black hole. Our model implies a mass of 5.0{sup +0.8}{sub -1.0} Multiplication-Sign 10{sup 7} M{sub Sun} for the central black hole, consistent with the average of determinations by methods involving stellar dynamics, and compatible (at 1{sigma} level) with measurements obtained from the most detailed models of the stellar disk around the central black hole. This value is also consistent with the M-{sigma} relation. In order to make a comparison, we applied our simulation on the stellar kinematics in the nucleus of M31 and concluded that the parameters obtained for the stellar disk are not formally compatible with the parameters obtained for the H{alpha} emitting disk. This result suggests that the stellar and the H{alpha} emitting disks are intrinsically different from each other. A plausible explanation is that the H{alpha} emission is associated with a gaseous disk. This hypothesis is supported by the detection of traces of weaker nebular lines in the nuclear region of M31. However, we cannot exclude the possibility that the H{alpha} emission is, at least partially, generated by stars.

  17. Insulin receptor substrate-3, interacting with Bcl-3, enhances p50 NF-{kappa}B activity

    Energy Technology Data Exchange (ETDEWEB)

    Kabuta, Tomohiro [Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8657 (Japan); Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8502 (Japan); Hakuno, Fumihiko; Cho, Yoshitake; Yamanaka, Daisuke; Chida, Kazuhiro [Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8657 (Japan); Asano, Tomoichiro [Graduate School of Biomedical Science, Hiroshima University, Hiroshima 734-8551 (Japan); Wada, Keiji [Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8502 (Japan); Takahashi, Shin-Ichiro, E-mail: atkshin@mail.ecc.u-tokyo.ac.jp [Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8657 (Japan)

    2010-04-09

    The insulin receptor substrate (IRS) proteins are major substrates of both insulin receptor and insulin-like growth factor (IGF)-I receptor tyrosine kinases. Previously, we reported that IRS-3 is localized to both cytosol and nucleus, and possesses transcriptional activity. In the present study, we identified Bcl-3 as a novel binding protein to IRS-3. Bcl-3 is a nuclear protein, which forms a complex with the homodimer of p50 NF-{kappa}B, leading to enhancement of transcription through p50 NF-{kappa}B. We found that Bcl-3 interacts with the pleckstrin homology domain and the phosphotyrosine binding domain of IRS-3, and that IRS-3 interacts with the ankyrin repeat domain of Bcl-3. In addition, IRS-3 augmented the binding activity of p50 to the NF-{kappa}B DNA binding site, as well as the tumor necrosis factor (TNF)-{alpha}-induced transcriptional activity of NF-{kappa}B. Lastly, IRS-3 enhanced NF-{kappa}B-dependent anti-apoptotic gene induction and consequently inhibited TNF-{alpha}-induced cell death. This series of results proposes a novel function for IRS-3 as a transcriptional regulator in TNF-{alpha} signaling, distinct from its function as a substrate of insulin/IGF receptor kinases.

  18. Alpha particle emitters in medicine

    International Nuclear Information System (INIS)

    Fisher, D.R.

    1989-09-01

    Radiation-induced cancer of bone, liver and lung has been a prominent harmful side-effect of medical applications of alpha emitters. In recent years, however, the potential use of antibodies labeled with alpha emitting radionuclides against cancer has seemed promising because alpha particles are highly effective in cell killing. High dose rates at high LET, effectiveness under hypoxic conditions, and minimal expectancy of repair are additional advantages of alpha emitters over antibodies labeled with beta emitting radionuclides for cancer therapy. Cyclotron-produced astatine-211 ( 211 At) and natural bismuth-212 ( 212 Bi) have been proposed and are under extensive study in the United States and Europe. Radium-223 ( 223 Ra) also has favorable properties as a potential alpha emitting label, including a short-lived daughter chain with four alpha emissions. The radiation dosimetry of internal alpha emitters is complex due to nonuniformly distributed sources, short particle tracks, and high relative specific ionization. The variations in dose at the cellular level may be extreme. Alpha-particle radiation dosimetry, therefore, must involve analysis of statistical energy deposition probabilities for cellular level targets. It must also account fully for nonuniform distributions of sources in tissues, source-target geometries, and particle-track physics. 18 refs., 4 figs

  19. Anti-IL-1alpha autoantibodies in early rheumatoid arthritis

    DEFF Research Database (Denmark)

    Forslind, K; Svensson, Birte; Svenson, M

    2001-01-01

    To investigate the potential predictive value of autoantibodies against IL1-alpha (anti-IL-1alpha) in patients with early rheumatoid arthritis (RA).......To investigate the potential predictive value of autoantibodies against IL1-alpha (anti-IL-1alpha) in patients with early rheumatoid arthritis (RA)....

  20. Collision dynamics and particle production in relativistic nucleus- nucleus collisions at CERN

    International Nuclear Information System (INIS)

    Harris, J.W.

    1990-03-01

    The possibility of forming a quark-gluon plasma is the primary motivation for studying nucleus-nucleus collisions at very high energies. Various ''signatures'' for the existence of a quark-gluon plasma in these collisions have been proposed. These include an enhancement in the production of strange particles, suppression of J/Ψ production, observation of direct photons from the plasma, event-by-event fluctuations in the rapidity distributions of produced particles, and various other observables. However, the system will evolve dynamically from a pure plasma or mixed phase through expansion, cooling, hadronization and freezeout into the final state particles. Therefore, to be able to determine that a new, transient state of matter has been formed it will be necessary to understand the space-time evolution of the collision process and the microscopic structure of hadronic interactions, at the level of quarks and gluons, at high temperatures and densities. In this talk I will review briefly the present state of our understanding of the dynamics of these collisions and, in addition, present a few recent results on particle production from the NA35 experiment at CERN. 21 refs., 5 figs

  1. Transport theory applied to hadron and light fragment production in high energy nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Schuermann, B.; Malfliet, R.; Mies, S.; Zwermann, W.

    1984-01-01

    Foundations of the transport theory for studying K + , K - , π - and light fragment production in nucleus-nucleus interactions at high energies are given. Inclusive production of protons, K + and π - in the Ne+NaF reaction at 400 MeV and 21 GeV/nucleon is consdered, their differential cross sections are caculated. Differential cross sections of K - and π - production in Si+Si → K + +X and Ne+NaF → π - +X reactions at the energy of 2.1 GeV/nucleon, their energy dependence are estimated. Comparison of the calculated and experimental data is graphically presented. The model of the transport theory is shown to successfully reproduce inclusive spectra of different particles (p, d, π, K + , K - ) in a wide energy range of incident particles (from 400 MeV to 2 GeV/nucleon). This approach can be generalized for lower energies by generating a mean nuclear potentiasl field

  2. Functionalized active-nucleus complex sensor

    Science.gov (United States)

    Pines, Alexander; Wemmer, David E.; Spence, Megan; Rubin, Seth

    2003-11-25

    A functionalized active-nucleus complex sensor that selectively associates with one or more target species, and a method for assaying and screening for one or a plurality of target species utilizing one or a plurality of functionalized active-nucleus complexes with at least two of the functionalized active-nucleus complexes having an attraction affinity to different corresponding target species. The functionalized active-nucleus complex has an active-nucleus and a targeting carrier. The method involves functionalizing an active-nucleus, for each functionalized active-nucleus complex, by incorporating the active-nucleus into a macromolucular or molecular complex that is capable of binding one of the target species and then bringing the macromolecular or molecular complexes into contact with the target species and detecting the occurrence of or change in a nuclear magnetic resonance signal from each of the active-nuclei in each of the functionalized active-nucleus complexes.

  3. Pion-nucleus scatter and the Pauli principle

    International Nuclear Information System (INIS)

    Dover, C.B.; Lemmer, R.H.

    1976-01-01

    A density expansion of the pion self-energy for pions in nuclear matter is reexamined. It is shown that a single hole-line expansion of the self-energy (i) is equivalent to using a strongly quenched πN scattering amplitude in the medium, and (ii) results in an inconsistent treatment of the virtual pions necessarily present in a field-theoretic description of the problem. Exchange of intermediate pions gives rise to nucleon-nucleon, as well as pion-nucleon scattering diagrams that both contribute to the pion self-energy in an essential way. The nucleon-nucleon scattering proceeds, for instance, via a one-pion-exchange potential that is, however, highly nonstatic for energy transfers between nucleons close to the incident energy. Such interactions are singled out automatically for special treatment in a field-theory approach to the problem, and should not be introduced in an ad hoc manner as part of an empirical NN interaction in nuclear matter. We evaluate the coherent and charge exchange contributions to the pion-nucleus optical potential, proportional to the total density and the neutron-proton density difference, respectively. The Pauli principle is found to provide a small correction to the coherent part, both in the hole-line and density expansion formalisms. However, the charge exchange part of the potential is almost completely damped at low energies in the hole-line expansion, while the inclusion of backward-going graphs (random-phase-approximation-type correlations) restores it to its value based on free space πN charge exchange amplitudes (i.e., no net Pauli effect)

  4. Strangeness production in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions in the dual parton model

    International Nuclear Information System (INIS)

    Moehring, H.; Ranft, J.; Capella, A.; Tran Thanh Van, J.

    1993-01-01

    Λ, bar Λ, and K S 0 production is studied in a Monte Carlo dual parton model for hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions with an SU(3) symmetric sea for chain formation (chain ends) but strangeness suppression in the chain fragmentation process. Additionally, (qq)-(bar q bar q) production from the sea was introduced into the chain formation process with the same probability as for the q→qq branching within the chain decay process. With these assumptions, multiplicity ratios and Feynman-x distributions for strange particles in h-h and multiplicity ratios in heavy ion collisions are reasonably well reproduced

  5. Use of studies with laboratory animals to assess the potential early health effects of combined internal alpha and beta irradiation

    International Nuclear Information System (INIS)

    Scott, B.R.; Hahn, F.F.; Guilmette, R.A.; Muggenburg, B.A.; Snipes, M.B.; Boecker, B.B.; McClellan, R.O.

    1986-01-01

    The potential health impacts of radionuclides released in nuclear accidents are of major concern to the public and to regulatory and other governmental agencies. One mode of potential exposure is by inhalation of airborne radionuclides, which could lead to combined internal irradiation by high (alpha) and low (beta) linear energy transfer (LET) radiations. Epidemiological data for health effects of human inhalation exposure are too limited to derive reliable estimates of risks of potential health effects. However, results of studies in which beagle dogs were exposed by inhalation to insoluble radioactive aerosols can be used to estimate expected effects in humans. Data for mortality from radiation pneumonitis and pulmonary fibrosis caused by internal irradiation of dog lungs by alpha or beta radiations are used to derive the relative biological effectiveness (RBE) of alpha irradiation compared to beta irradiation; predict the expected combined effects of alpha and beta irradiation of dog lungs; and extrapolate the results to humans. The extrapolation to humans assumed that, for similar ages at exposure, dog and human lungs have similar sensitivities to lung irradiation. Results of theoretical calculations related to mortality from early effects indicated that the synergistic effects of high- and low-LET radiations should depend on the percentages of the total dose contributed by high- and low-LET radiations, and for very low or very high doses, synergistic effects should be negligible. 23 refs., 8 figs

  6. Detector development and background estimation for the observation of Coherent Neutrino Nucleus Scattering (CNNS)

    Energy Technology Data Exchange (ETDEWEB)

    Guetlein, Achim; Ciemniak, Christian; Feilitzsch, Franz von; Lanfranchi, Jean-Come; Oberauer, Lothar; Potzel, Walter; Roth, Sabine; Schoenert, Stefan; Sivers, Moritz von; Strauss, Raimund; Wawoczny, Stefan; Willers, Michael; Zoeller, Andreas [Technische Universitaet Muenchen, Physik-Department, E15 (Germany)

    2012-07-01

    The Coherent Neutrino Nucleus Scattering (CNNS) is a neutral current process of the weak interaction and is thus flavor independent. A low-energetic neutrino scatters off a target nucleus. For low transferred momenta the wavelength of the transferred Z{sup 0} boson is comparable to the diameter of the target nucleus. Thus, the neutrino interacts with all nucleons coherently and the cross section for the CNNS is enhanced. To observe CNNS for the first time we are developing cryogenic detectors with a target mass of about 10 g each and an energy threshold of less than 0.5 keV. The current status of this development is presented as well as the estimated background for an experiment in the vicinity of a nuclear power reactor as a strong neutrino source.

  7. Additional evaluation of alpha induced neutron production nuclear data. 9Be, 27Al, 28,29,30Si

    International Nuclear Information System (INIS)

    Murata, Toru; Shibata, Keiichi

    2005-01-01

    Alpha particle induced neutron production cross sections, emitted neutron energy spectrum and angular distributions were evaluated for the target nucleus 9 Be, 27 Al and Si isotopes; 28 Si, 29 Si and 30 Si in the incident energy region below 15 MeV. (author)

  8. Interactions between the cyclic AMP receptor protein and the alpha subunit of RNA polymerase at the Escherichia coli galactose operon P1 promoter.

    Science.gov (United States)

    Attey, A; Belyaeva, T; Savery, N; Hoggett, J; Fujita, N; Ishihama, A; Busby, S

    1994-10-25

    DNAase I footprinting has been used to study open complexes between Escherichia coli RNA polymerase and the galactose operon P1 promoter, both in the absence and the presence of CRP (the cyclic AMP receptor protein, a transcription activator). From the effects of deletion of the C-terminal part of the RNA polymerase alpha subunit, we deduce that alpha binds at the upstream end of both the binary RNA polymerase-galP1 and ternary RNA polymerase-CRP-galP1 complexes. Disruption of the alpha-upstream contact suppresses open complex formation at galP1 at lower temperatures. In ternary RNA polymerase-CRP-galP1 complexes, alpha appears to make direct contact with Activating Region 1 in CRP. DNAase I footprinting has been used to detect and quantify interactions between purified alpha and CRP bound at galP1.

  9. Neutrino-nucleus reaction rates based on the relativistic quasiparticle random phase approximation

    International Nuclear Information System (INIS)

    Paar, N.; Vretenar, D.; Marketin, T.; Ring, P.

    2008-01-01

    Neutrino-nucleus cross sections are described in a novel theoretical framework where the weak interaction of leptons with hadrons is expressed in the standard current-current form, the nuclear ground state is described in the relativistic Hartree-Bogoliubov model, and the relevant transitions to excited states are calculated in the relativistic quasiparticle random phase approximation. The model is employed in studies of neutrino-nucleus reactions in several test cases

  10. Endothelial monocyte activating polypeptide-II modulates endothelial cell responses by degrading hypoxia-inducible factor-1alpha through interaction with PSMA7, a component of the proteasome

    Energy Technology Data Exchange (ETDEWEB)

    Tandle, Anita T. [Tumor Angiogenesis Section, Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892 (United States); Calvani, Maura; Uranchimeg, Badarch [DTP-Tumor Hypoxia Laboratory, SAIC Frederick, Inc., National Cancer Institute, Frederick, Maryland 21702 (United States); Zahavi, David [Tumor Angiogenesis Section, Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892 (United States); Melillo, Giovanni [DTP-Tumor Hypoxia Laboratory, SAIC Frederick, Inc., National Cancer Institute, Frederick, Maryland 21702 (United States); Libutti, Steven K., E-mail: slibutti@montefiore.org [Department of Surgery, Montefiore-Einstein Center for Cancer Care, Albert Einstein College of Medicine, Greene Medical Arts Pavilion, 4th Floor 3400, Bainbridge Avenue, Bronx, New York 10467 (United States)

    2009-07-01

    The majority of human tumors are angiogenesis dependent. Understanding the specific mechanisms that contribute to angiogenesis may offer the best approach to develop therapies to inhibit angiogenesis in cancer. Endothelial monocyte activating polypeptide-II (EMAP-II) is an anti-angiogenic cytokine with potent effects on endothelial cells (ECs). It inhibits EC proliferation and cord formation, and it suppresses primary and metastatic tumor growth in-vivo. However, very little is known about the molecular mechanisms behind the anti-angiogenic activity of EMAP-II. In the present study, we explored the molecular mechanism behind the anti-angiogenic activity exerted by this protein on ECs. Our results demonstrate that EMAP-II binds to the cell surface {alpha}5{beta}1 integrin receptor. The cell surface binding of EMAP-II results in its internalization into the cytoplasmic compartment where it interacts with its cytoplasmic partner PSMA7, a component of the proteasome degradation pathway. This interaction increases hypoxia-inducible factor 1-alpha (HIF-1{alpha}) degradation under hypoxic conditions. The degradation results in the inhibition of HIF-1{alpha} mediated transcriptional activity as well as HIF-1{alpha} mediated angiogenic sprouting of ECs. HIF-1{alpha} plays a critical role in angiogenesis by activating a variety of angiogenic growth factors. Our results suggest that one of the major anti-angiogenic functions of EMAP-II is exerted through its inhibition of the HIF-1{alpha} activities.

  11. 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)

  12. Functional and genomic analyses of alpha-solenoid proteins.

    Science.gov (United States)

    Fournier, David; Palidwor, Gareth A; Shcherbinin, Sergey; Szengel, Angelika; Schaefer, Martin H; Perez-Iratxeta, Carol; Andrade-Navarro, Miguel A

    2013-01-01

    Alpha-solenoids are flexible protein structural domains formed by ensembles of alpha-helical repeats (Armadillo and HEAT repeats among others). While homology can be used to detect many of these repeats, some alpha-solenoids have very little sequence homology to proteins of known structure and we expect that many remain undetected. We previously developed a method for detection of alpha-helical repeats based on a neural network trained on a dataset of protein structures. Here we improved the detection algorithm and updated the training dataset using recently solved structures of alpha-solenoids. Unexpectedly, we identified occurrences of alpha-solenoids in solved protein structures that escaped attention, for example within the core of the catalytic subunit of PI3KC. Our results expand the current set of known alpha-solenoids. Application of our tool to the protein universe allowed us to detect their significant enrichment in proteins interacting with many proteins, confirming that alpha-solenoids are generally involved in protein-protein interactions. We then studied the taxonomic distribution of alpha-solenoids to discuss an evolutionary scenario for the emergence of this type of domain, speculating that alpha-solenoids have emerged in multiple taxa in independent events by convergent evolution. We observe a higher rate of alpha-solenoids in eukaryotic genomes and in some prokaryotic families, such as Cyanobacteria and Planctomycetes, which could be associated to increased cellular complexity. The method is available at http://cbdm.mdc-berlin.de/~ard2/.

  13. Protein quality control in the nucleus

    DEFF Research Database (Denmark)

    Nielsen, Sofie V.; Poulsen, Esben Guldahl; Rebula, Caio A.

    2014-01-01

    to aggregate, cells have evolved several elaborate quality control systems to deal with these potentially toxic proteins. First, various molecular chaperones will seize the misfolded protein and either attempt to refold the protein or target it for degradation via the ubiquitin-proteasome system...... to be particularly active in protein quality control. Thus, specific ubiquitin-protein ligases located in the nucleus, target not only misfolded nuclear proteins, but also various misfolded cytosolic proteins which are transported to the nucleus prior to their degradation. In comparison, much less is known about...... these mechanisms in mammalian cells. Here we highlight recent advances in our understanding of nuclear protein quality control, in particular regarding substrate recognition and proteasomal degradation....

  14. Environmental light and suprachiasmatic nucleus interact in the regulation of body temperature.

    NARCIS (Netherlands)

    Scheer, F.A.J.L.; Pirovano, C.; Someren, E.J.W. van; Buijs, R.M.

    2005-01-01

    The mammalian biological clock, located in the suprachiasmatic nucleus (SCN), is crucial for circadian rhythms in physiology and behavior. However, equivocal findings have been reported on its role in the circadian regulation of body temperature. The goal of the present studies was to investigate

  15. Properties of an α Particle in a Bohrium 270 Nucleus under the Generalized Symmetric Woods-Saxon Potential

    Directory of Open Access Journals (Sweden)

    Bekir Can LÜTFÜOĞLU

    2017-04-01

    Full Text Available The energy eigenvalues and the wave functions of an α particle in a Bohrium 270 nucleus have been calculated by solving Schrödinger equation for Generalized Symmetric Woods-Saxon potential. Using the energy spectrum by excluding and including the quasi-bound eigenvalues, entropy, internal energy, Helmholtz energy, and specific heat, as functions of reduced temperature have been calculated. Stability and emission characteristics have been interpreted in terms of the wave and thermodynamic functions. The kinetic energy of a decayed α particle was calculated using the quasi-bound states, which has been found close to the experimental value.

  16. Quantitative receptor radioautography in the study of receptor-receptor interactions in the nucleus tractus solitarii

    Directory of Open Access Journals (Sweden)

    Fior-Chadi D.R.

    1998-01-01

    Full Text Available The nucleus tractus solitarii (NTS in the dorsomedial medulla comprises a wide range of neuropeptides and biogenic amines. Several of them are related to mechanisms of central blood pressure control. Angiotensin II (Ang II, neuropeptide Y (NPY and noradrenaline (NA are found in the NTS cells, as well as their receptors. Based on this observation we have evaluated the modulatory effect of these peptide receptors on a2-adrenoceptors in the NTS. Using quantitative receptor radioautography, we observed that NPY and Ang II receptors decreased the affinity of a2-adrenoceptors for their agonists in the NTS of the rat. Cardiovascular experiments agreed with the in vitro data. Coinjection of a threshold dose of Ang II or of the NPY agonists together with an ED50 dose of adrenergic agonists such as NA, adrenaline and clonidine counteracted the depressor effect produced by the a2-agonist in the NTS. The results provide evidence for the existence of an antagonistic interaction between Ang II at1 receptors and NPY receptor subtypes with the a2-adrenoceptors in the NTS. This receptor interaction may reduce the transduction over the a2-adrenoceptors which can be important in central cardiovascular regulation and in the development of hypertension

  17. Odd-Z Transactinide Compound Nucleus Reactions Including the Discovery of 260Bh

    International Nuclear Information System (INIS)

    Nelson, Sarah L; Nelson, Sarah L

    2008-01-01

    Several reactions producing odd-Z transactinide compound nuclei were studied with the 88-Inch Cyclotron and the Berkeley Gas-Filled Separator at the Lawrence Berkeley National Laboratory. The goal was to produce the same compound nucleus at or near the same excitation energy with similar values of angular momentum via different nuclear reactions. In doing so, it can be determined if there is a preference in entrance channel, because under these experimental conditions the survival portion of Swiatecki, Siwek-Wilcznska, and Wilczynski's 'Fusion By Diffusion' model is nearly identical for the two reactions. Additionally, because the same compound nucleus is produced, the exit channel is the same. Four compound nuclei were examined in this study: 258Db, 262Bh, 266Mt, and 272Rg. These nuclei were produced by using very similar heavy-ion induced-fusion reactions which differ only by one proton in the projectile or target nucleus (e.g.: 50Ti + 209Bi vs. 51V + 208Pb). Peak 1n exit channel cross sections were determined for each reaction in each pair, and three of the four pairs; cross sections were identical within statistical uncertainties. This indicates there is not an obvious preference of entrance channel in these paired reactions. Charge equilibration immediately prior to fusion leading to a decreased fusion barrier is the likely cause of this phenomenon. In addition to this systematic study, the lightest isotope of element 107, bohrium, was discovered in the 209Bi(52Cr,n) reaction. 260Bh was found to decay by emission of a 10.16 MeV alpha particle with a half-life of 35 ms. The cross section is 59 pb at an excitation energy of 15.0 MeV. The effect of the N = 152 shell is also seen in this isotope's alpha particle energy, the first evidence of such an effect in Bh. All reactions studied are also compared to model predictions by Swiatecki, Siwek-Wilcznska, and Wilczynski's 'Fusion By Diffusion' theory

  18. Inclusive charged-current neutrino-nucleus reactions calculated with the relativistic quasiparticle random-phase approximation

    International Nuclear Information System (INIS)

    Paar, N.; Vretenar, D.; Marketin, T.; Ring, P.

    2008-01-01

    Inclusive neutrino-nucleus cross sections are calculated using a consistent relativistic mean-field theoretical framework. The weak lepton-hadron interaction is expressed in the standard current-current form, the nuclear ground state is described with the relativistic Hartree-Bogoliubov model, and the relevant transitions to excited nuclear states are calculated in the relativistic quasiparticle random-phase approximation. Illustrative test calculations are performed for charged-current neutrino reactions on 12 C, 16 O, 56 Fe, and 208 Pb, and results compared with previous studies and available data. Through the use of the experimental neutrino fluxes, the averaged cross sections are evaluated for nuclei of interest for neutrino detectors. We analyze the total neutrino-nucleus cross sections and the evolution of the contribution of the different multipole excitations as a function of neutrino energy. The cross sections for reactions of supernova neutrinos on 16 O and 208 Pb target nuclei are analyzed as functions of the temperature and chemical potential

  19. Hyperspherical effective interaction for nonlocal potentials

    International Nuclear Information System (INIS)

    Barnea, N.; Leidemann, W.; Orlandini, G.

    2010-01-01

    The effective interaction hyperspherical-harmonics method, formulated for local forces, is generalized to accommodate nonlocal interactions. As for local potentials this formulation retains the separation of the hyper-radial part leading solely to a hyperspherical effective interaction. By applying the method to study ground-state properties of 4 He with a modern effective-field-theory nucleon-nucleon potential model (Idaho-N3LO), one finds a substantial acceleration in the convergence rate of the hyperspherical-harmonics series. Also studied are the binding energies of the six-body nuclei 6 He and 6 Li with the JISP16 nuclear force. Again an excellent convergence is observed.

  20. A study of etching model of alpha-recoil tracks in biotite

    International Nuclear Information System (INIS)

    Dong Jinquan; Yuan Wanming; Wang Shicheng; Fan Qicheng

    2005-01-01

    Like fission-track dating, alpha-recoil track (ART) dating is based on the accumulation of nuclear particles that the released from natural radioactivity and produce etchable tracks in solids. ARTs are formed during the alpha-decay of uranium and thorium as well as of their daughter nuclei. When emitting an alpha-particle, the heavy remaining nucleus recoils 30-40 nm, leaving behind a trail of radiation damage. Through etching the ART tracks become visible with the aid of an interference phase-contrast microscope. Under the presupposition that all tracks are preserved since the formation of a sample their total number is a measure of the sample's age. The research for etching model is to accurately determine ART volume density, i.e., the number of ARTs per unit volume. The volume density of many dots in many layers may be determined on a sample using this etching model, and as decreasing the error and increasing the accuracy. (authors)