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Sample records for 35cl nucleus struktura

  1. Fourier-transform microwave spectroscopy of 24Mg 35Cl generated by laser ablation

    Ohshima, Yasuhiro; Endo, Yasuki

    1993-10-01

    The rotational spectrum of 24Mg 35Cl in its X 2Σ + (ν=0 and 1 ) state has been observed in the 14 GHz region by using a Fourier- transform microwave spectrometer combined with a laser-ablation source. The radical was produced by the reaction of atomic Mg vaporized by 532 nm laser light with Cl 2 diluted in Ar. The present observation of the lowest N transition by a high-resolving power instrument has provided accurate hyperfine coupling constants associated with the 35Cl nucleus of this molecule.

  2. 35Cl + 12C asymmetrical fission excitation functions

    The fully energy-damped yields from the 35Cl + 12C reaction have been systematically investigated using particle-particle coincidence techniques at a 35Cl bombarding energy of ∼ 8 MeV/nucleon. The fragment-fragment correlation data show that the majority of events arises from a binary-decay process with rather large numbers of secondary light-charged particles emitted from the two excited exit fragments. No evidence is observed for ternary breakup events. The binary-process results of the present measurement, along with those of earlier, inclusive experimental data obtained at several lower bombarding energies are compared with predictions of two different kinds of statistical model calculations. The methods give comparable predictions and are both in good agreement with the experimental results thus confirming the fusion-fission origin of the fully-damped yields. (author)

  3. AMS measurement of the reaction 35Cl(n,γ)36Cl

    36Cl is a long-lived radionuclide (t1/2=301000 a), which is dominantly produced via the reaction 35Cl(n,γ)36Cl. In the present work we focused on: First, the production of an independent 36Cl/35Cl reference material for AMS and second, the determination of the Maxwellian averaged cross section (MACS) of 35Cl(n,γ)36Cl at 25 keV neutron energy, i.e. the energy range which is important for astrophysical network calculations. Approaching the first goal, NaCl pellets were irradiated with thermal neutrons in Vienna and Budapest. The neutron fluence, used for the calculation of the 36Cl/35Cl ratio of the irradiated samples, was determined via gold fluence monitors. For the determination of the neutron capture cross section of 35Cl at stellar energies, AMS measurements were performed on two samples, which were irradiated with neutrons of a Maxwell-Boltzmann energy distribution of 25 keV. Combining the AMS- and the neutron-fluence data, the MACS for 35Cl at 25 keV was calculated. The neutron irradiations, the measuring procedure of 36Cl at VERA and our new results are presented.

  4. STRUKTURA DODAJANJA V PREDŠOLSKEM OBDOBJU

    Štefanec, Iris

    2016-01-01

    Diplomsko delo z naslovom Struktura dodajanja v predšolskem obdobju govori o teoretičnih podlagah omenjene strukture in empiričnih podatkih o sposobnosti otrok za dojemanje le-te. Namen diplomskega dela je raziskati koliko so otroci v starosti 5-6 let, sposobni doumeti strukturo dodajanja, vezano na računsko operacijo seštevanja. Raziskave smo se lotili z izvajanjem in evalvacijo matematične aktivnosti Lonček, skozi katero smo tudi ugotavljali ali je ta primerna za to starost, ter katerega na...

  5. Change in the 35Cl NQR spectrum under pressure and thermal effect

    The investigation of spectral parameters of nuclear quadrupole resonance in RbICl4 under pressure and temperature effect is carried out. Baric and temperature dependencies of the nuclear quadrupole resonance spectra of 35Cl are obtained. Baric frequency dependencies of 35Cl nuclear quadrupole resonance in RbICl4, obtained at 253, 291 and 311K, are linear and are characterized by a negative slope caused by a high degree of molecular orbitals overlap already under atmospheric pressure. A curve of phase coexistence for RbICl4 is drawn from the results of temperature and baric frequency dependencies of the 35Cl nuclear quadrupole resonance. The found spectra multiplicity of the flat quadratic anion [ICl4] is supposed to be explained by contributions of neighbouring ions into the gradient of the electric field on the chlorine nuclei

  6. Determination of chemical states of sulphur 35 obtained from the 35Cl (n, p)35S

    The chemical states of sulphur-35 obtained from the 35Cl(n,p)35S reaction by the irradiation of potassium chloride without any previous treatment and with previous heating under vacuum, were determined. The influence of irradiation time and temperature after irradiation was examined. Paper electrophoresis technique was employed for the determination of the chemical states. (Author)

  7. Investigation of the reaction 35Cl(n,γ)36Cl

    The γ-radiation following capture of non-polarized thermal neutrons in 35Cl has been investigated. Of the 420 γ-rays ascribed to the 35Cl(n,γ)36Cl reaction, 236 have been placed in a 36Cl decay scheme. The branching ratios and the excitation energies (with 0.04-0.9 KeV errors) of 72 bound states have been determined. Spin assignments and spin restrictions or confirmations have been made for a total of 20 levels. The multipole mixing ratios for some primary γ-ray transitions have been determined. There exists a significant correlation between (d,p) stripping strengths and (n,γ) reduced primary transition probabilities for transitions to lsub(n)(d,p) = 0 levels

  8. Preparation and characterization of sup 35 Cl and sup 36 Cl samples for (n,p) cross section measurements

    Eykens, R.; Goetz, A.; Lamberty, A.; Gestel, J. van; Pauwels, J. (Commission of the European Communities, Joint Research Centre, Central Bureau for Nuclear Measurements, Geel (Belgium)); Wagemans, C.; Druyts, S. (Nuclear Physics Lab., State Univ., Ghent (Belgium)); Hondt, P. d' (SCK/CEN, Mol (Belgium))

    1991-05-15

    The {sup 35}Cl(n,p) and the {sup 36}Cl(n,p) reactions are of great importance for astrophysics. Several silver chloride samples were evaporated on platinum coated aluminium backings. The sample definition has been achieved by combining destructive and non-destructive methods. The isotopic composition of the {sup 36}Cl-enriched material was verified. Pulse height spectra of {sup 35}Cl(n{sub th},p) and {sup 36}Cl(n{sub th},p) are shown. The samples prepared and assayed in this way have proven to fulfil the experimental requirements and have been used to determine the reaction cross sections of {sup 35}Cl(n{sub th},p) and {sup 36}Cl(n{sub th},p). (orig.).

  9. Nuclear quadrupole resonance 35Cl in the complexes of the 5 group element pentafluorides with trifluoride and pentafluoride of chlorine

    The following complexes are investigated on 35Cl at 77 K by the NQR method: ClF5xnSbF5 (n=1, 2, 4), ClF5xTaF5, ClF3xnSbF5 (n=1, 2, 4), ClF3xMF5 (M=As,Nb,Ta), ClF5 and CsClF4. The order of the increase of the MF5 acseptor ability is established according the 35Cl NQR spectra. The correlation dependences in ClF3xMF5 complexes are found between ν(35Cl) and the electronegativity difference of F and M, and also between ν(35Cl) and the MF5 formation heats. Calculated are the population of valent 3p-orbitals of chlorium atoms in the ClF3xMF5 complexes, and in ClF3, ClF and CsClF4 as well

  10. The 35Cl/37Cl isotopic ratio in dense molecular clouds: HIFI observations of hydrogen chloride towards W3A

    Cernicharo, J; Daniel, F; Agundez, M; Caux, E; de Graauw, T; De Jonge, A; Kester, D; Leduc, H G; Steinmetz, E; Stutzki, J; Ward, J S

    2010-01-01

    We report on the detection with the HIFI instrument on board the Herschel satellite of the two hydrogen chloride isotopologues, H35Cl and H37Cl, towards the massive star-forming region W3A. The J=1-0 line of both species was observed with receiver 1b of the HIFI instrument at 625.9 and 624.9 GHz. The different hyperfine components were resolved. The observations were modeled with a non-local, non-LTE radiative transfer model that includes hyperfine line overlap and radiative pumping by dust. Both effects are found to play an important role in the emerging intensity from the different hyperfine components. The inferred H35Cl column density (a few times 1e14 cm^-2), and fractional abundance relative to H nuclei (~7.5e^-10), supports an upper limit to the gas phase chlorine depletion of ~200. Our best-fit model estimate of the H35Cl/H37Cl abundance ratio is ~2.1+/-0.5, slightly lower, but still compatible with the solar isotopic abundance ratio (~3.1). Since both species were observed simultaneously, this is the...

  11. Metoda superpozicije domena u analizi slobodnih vibracija tekstilnih kompozitnih struktura

    Jiang, W. G.; Yu, C. L.; Zhang, Y. X.; Huo, X. C.; Yan, L J

    2015-01-01

    Tekstilni kompoziti načinjeni su od isprepletenih vlakana koja se impregniraju matričnim materijalom i zatim očvršćuju. Preplitanjem vlakana može se povećati poprečna čvrstoća u usporedbi s konvencionalnim laminarnim kompozitima. Međutim, nedostatak tekstilnih kompozita je teško predviđanje osobina zbog složene geometrije unutarnje građe. Analiza konačnih elemenata (FEA) postala je učinkovito sredstvo za predviđanje ponašanja složenih tekstilnih kompozitnih struktura. Jedan od problema koji s...

  12. 35Cl and 1H NMR study of anion binding to reduced bovine copper-zinc superoxide dismutase

    Binding of chloride to reduced bovine copper-zinc superoxide dismutase (Cu2Zn2SOD) and chemically modified derivatives was monitored by the line width at half-height of the Cl- resonance as measured by 35Cl nuclear magnetic resonance (NMR) spectroscopy. Reduced arginine-modified and reduced lysine-modified Cu2Zn2SOD (at concentrations of 2.14 x 10-4 M) caused less broadening of the Cl- resonance line width of 0.1 M NaCl solutions than did reduced native protein when measured under the same conditions; Cl- broadening with all protein derivatives decreased drastically in the presence of 0.05 M phosphate. The C-H and N-H proton resonances of histidyl imidazoles of reduced native and reduced lysine-modified Cu2Zn2SOD were shifted by addition of Cl- (with apparent affinity constants of 12 and ∼ 2 M-1, respectively) whereas this anion had less effect in the 1H NMR spectrum of reduced arginine-modified Cu2Zn2SOD (affinity constant -1) under the same conditions. phosphate caused relatively smaller changes on the 1H NMR resonances of all reduced protein derivatives. The competition measured by 1H NMR spectroscopy between chloride and phosphate for anion binding sites in the neighborhood of the Cu1 ion was much less than that for nonspecific Cl- binding monitored by 35Cl NMR spectroscopy. It is concluded from these experiments that, in addition to the weak anion binding at or near the CuI ion, Arg-141, Lys-120, and Lys-134 serve as major anion binding sites in the reduced native protein. 57 refs., 5 figs., 2 tabs

  13. Decay studies of 59Cu* formed in the 35Cl + 24Mg reaction using the dynamical cluster-decay model

    Karthikraj, C.; Balasubramaniam, M.

    2013-02-01

    The reformulated dynamical cluster-decay model (DCM) is applied to study the decay of odd-A and non-α structured 59Cu* formed in the 35Cl+24Mg reaction at Elab=275 MeV. Here, the temperature (T)-dependent binding energies due to Krappe are used. The roles of Wigner and pairing energies in the fragmentation potential are explicitly shown in this work. For the temperature T=4.1898 MeV corresponding to Elab=275 MeV, the contribution of pairing vanishes and the resulting structure of the fragmentation potential due to Wigner term is shown. In addition to this, we have studied the role of factor α appearing in the inertia part of the equation of motion dictating the mass-transfer process. It is shown that this factor has significant effect in the structure of preformation probability values and hence in turn we see significant changes in the cross sections. We compare the cross sections of the measured charge distributions of the fission fragments for two limiting values of the parameter α with the experimental data. In order to fit the total cross-section values, a linear relation is obtained between the free parameter of the model ▵R and the factor α appearing in the hydrodynamical mass.

  14. Fragmentation Cross Sections of Medium-Energy 35Cl, 40Ar, and 48TiBeams on Elemental Targets

    Zeitlin, C.; Guetersloh, S.; Heilbronn, L.; Miller, J.; Fukumura,A.; Iwata, Y.; Murakami, T.; Sihver, L.; Mancusi, D.

    2007-12-08

    Charge-changing and fragment production cross sections at 0degrees have been obtained for interactions of 290, 400, and 650MeV/nucleon 40Ar beams, 650 and 1000 MeV/nucleon 35Cl beams, and a 1000MeV/nucleon 48Ti beam. Targets of C, CH2, Al, Cu, Sn, and Pb were used.Using standard analysis methods, we obtain fragment cross sections forcharges as low as 8 for Cl and Ar beams, and as low as 10 for the Tibeam. Using data obtained with small-acceptance detectors, we reportfragment production cross sections for charges as low as 5, corrected foracceptance using a simple model of fragment angular distributions. Withthe lower-charged fragment cross sections, we cancompare the data topredictions from several models (including NUCFRG2, EPAX2, and PHITS) ina region largely unexplored in earlier work. As found in earlier workwith other beams, NUCFRG2 and PHITS predictions agree reasonably wellwith the data for charge-changing cross sections, but do not accuratelypredict the fragment production cross sections. The cross sections forthe lightest fragments demonstrate the inadequacy of several models inwhich the cross sections fall monotonically with the charge of thefragment. PHITS, despite not agreeing particularly well with the fragmentproduction cross sections on average, nonetheless qualitativelyreproduces somesignificant features of the data that are missing from theother models.

  15. Detection of chloronium and measurement of the 35Cl/37Cl isotopic ratio at z=0.89 toward PKS1830-211

    Muller, S; Guelin, M; Henkel, C; Combes, F; Gerin, M; Aalto, S; Beelen, A; Darling, J; Horellou, C; Martin, S; Menten, K M; Dinh-V-Trung,; Zwaan, M A

    2014-01-01

    We report the first extragalactic detection of chloronium (H2Cl+), in the z=0.89 absorber in front of the lensed blazar PKS1830-211. The ion is detected through its 1_11-0_00 line along two independent lines of sight toward the North-East and South-West images of the blazar. The relative abundance of H2Cl+ is significantly higher (by a factor ~7) in the NE line of sight, which has a lower H2/H fraction, indicating that H2Cl+ preferably traces the diffuse gas component. From the ratio of the H2^35Cl+ and H2^37Cl+ absorptions toward the SW image, we measure a 35Cl/37Cl isotopic ratio of 3.1 (-0.2; +0.3) at z=0.89, similar to that observed in the Galaxy and the solar system.

  16. 35Cl NQR and Structural Studies of Chloroacetanilides C6H3Cl2NHCOCH3-xClx, 1 ≤ x ≤ 3

    Groke, Dirk; Dou, Shi-Qi; Weiss, Alarich

    1992-02-01

    The temperature dependence of 35Cl NQR frequencies and the phase transition behaviour of chloroacetanilides (N-[2,6-dichlorophenyl]-2-chloroacetamide, -2,2-dichloroacetamide, -2,2,2-trichloroacetamide) were investigated. The crystal structure determination of N-[2,6-dichlorophenyl]- 2-chloroacetamide leads to the following: a = 1893.8 pm, b = 1110.7 pm, c = 472.1 pm, space group P212121 = D24 with Z = 4 molecules per unit cell. The arrangement of the molecules and their geometry is comparable to the high temperature phase of the acetyl compound N-[2,6-dichlorophenyl]- acetamide. For N-[2,6-diclorophenyl]-2,2,2-trichloroacetamide it was found: a = 1016.6 pm, b = 1194.3 pm, c = 1006.7 pm, ß= 101.79°, space group P21/c = C52h, Z = 4. The structure is similar to the low temperature phase of N-[2,6-dichlorophenyl]-acetamide. Parallelism between the temperature dependence of the 35C1 NQR lines of the CCl3 group and the X-ray diffraction results concerning the different behaviour of the chlorine atoms was observed. The structures of the compounds show intermolecular hydrogen bonding of the N - H • • • O - C type. The phenyl group and the HNCO function are nearly planar. A bleaching out of several 35Cl NQR lines at a temperature far below the melting point of the substances was observed. The different types of chlorine atoms (aromatic, chloromethyl) can be distinguished by their temperature coefficients of the 35Cl NQR frequencies. All the resonances found show normal "Bayer" temperature behaviour. N-[2,6-dichlorophenyl]-2,2-diehloroacetamide shows several solid phases. One stable low temperature phase and an instable high temperature phase (at room temperature) were observed. The different phases were detected by means of 35Cl NQR spectroscopy and thermal analysis

  17. Struktura i svojstva plazma sprej Aps - Nikal - Aluminid prevlake

    Mihailo Rade Mrdak

    2013-06-01

    temperaturi pri brzini od 1 mm/min. Mikrostrukturna analiza slojeva prevlaka urađena je na svetlosnom mikroskopu. Morfologija površine deponovane prevlake i morfologija loma najboljih slojeva ispitana je na SEM-u (skening elektronskom mikroskopu. Rezultati i diskusija Vrednosti mikrotvrdoće slojeva prevlaka u direktnoj su vezi sa plazma sprej odstojanjem. Plazma sprej odstojanja bitno utiču na vrednosti mikrotvrdoće i čvrstoće spoja deponovanih slojeva. Slojevi Ni20Al prevlake deponovane sa najmanjim odstojanjem od 80 mm imaju vrednost mikrotvrdoće od  220HV0.3 koja je u granicama koju propisuje proizvođač praha (190–230HV0.3 (Material Product Data Sheet, 2011. Najveću vrednost mikrotvrdoće od 273 HV0.3 imali su slojevi sa najvećim udelom oksida koji su deponovani sa plazma sprej odstojanjem od 100 mm. Slojevi prevlaka deponovanih sa većim odstojanjem imali su vrednosti mikrotvrdoće iznad propisanih vrednosti. Vrednosti mikrotvrdoća prevlaka bile su u skladu sa udelima oksida u deponovanim slojevima. Merenjem vrednosti zatezne čvrstoće spoja ustanovljeno je da su se za sva tri plazma sprej odstojanja dobile vrednosti više od 20.7MPa, koju propisuje proizvođač praha (Material Product Data Sheet, 2011. Sve deponovane prevlake imale su dobre vrednosti zatezne čvrstoće spoja koje proizilaze iz egzotermne reakcije Al i Ni koja se dešava za vreme depozicije praha (McPherson, Cheang, 1989, (Deevi, et al., 1997, pp.335-344, (Material Product Data Sheet, 2011. Najveću vrednost čvrstoće spoja od 39MPa pokazali su slojevi koji su deponovani sa najmanjim plazma sprej odstojanjem. Ti slojevi imali su najmanji udeo oksida NiO i Υ- Al2O3 i pora. Na slikama 3 i 4. su prikazane mikrostrukture slojeva deponovanih sa plazma sprej odstojanjem 80 mm, koji su imali najbolju mikrostrukturu i mehaničke karakteristike. Struktura prevlake je lamelarna. Slojevi prevlake deponovani su kontinualno bez prisustva mikropukotina i makropukotina. U slojevima nisu prisutne

  18. NMR shielding and spin–rotation constants of 175LuX (X = 19F, 35Cl, 79Br, 127I) molecules

    This presentation demonstrates the relativistic effects on the spin-rotation constants, absolute nuclear magnetic resonance (NMR) shielding constants and shielding spans of 175LuX (X = 19F, 35Cl, 79Br, 127I) molecules. The results are obtained from calculations performed using density functional theory (non-relativistic and four-component relativistic) and coupled-cluster calculations. The spin-rotation constants are compared with available experimental values. In most of the molecules studied, relativistic effects make an order of magnitude difference on the NMR absolute shielding constants

  19. NMR shielding and spin–rotation constants of {sup 175}LuX (X = {sup 19}F, {sup 35}Cl, {sup 79}Br, {sup 127}I) molecules

    Demissie, Taye B. [Centre for Theoretical and Computational Chemistry Department of Chemistry, UiT – The Arctic University of Norway, N-9037 Tromsø (Norway)

    2015-12-31

    This presentation demonstrates the relativistic effects on the spin-rotation constants, absolute nuclear magnetic resonance (NMR) shielding constants and shielding spans of {sup 175}LuX (X = {sup 19}F, {sup 35}Cl, {sup 79}Br, {sup 127}I) molecules. The results are obtained from calculations performed using density functional theory (non-relativistic and four-component relativistic) and coupled-cluster calculations. The spin-rotation constants are compared with available experimental values. In most of the molecules studied, relativistic effects make an order of magnitude difference on the NMR absolute shielding constants.

  20. 35Cl NQR frequency and spin lattice relaxation time in 3,4-dichlorophenol as a function of pressure and temperature.

    Ramu, L; Ramesh, K P; Chandramani, R

    2013-01-01

    The pressure dependences of (35)Cl nuclear quadrupole resonance (NQR) frequency, temperature and pressure variation of spin lattice relaxation time (T(1)) were investigated in 3,4-dichlorophenol. T(1) was measured in the temperature range 77-300 K. Furthermore, the NQR frequency and T(1) for these compounds were measured as a function of pressure up to 5 kbar at 300 K. The temperature dependence of the average torsional lifetimes of the molecules and the transition probabilities W(1) and W(2) for the Δm = ±1 and Δm = ±2 transitions were also obtained. A nonlinear variation of NQR frequency with pressure has been observed and the pressure coefficients were observed to be positive. A thermodynamic analysis of the data was carried out to determine the constant volume temperature coefficients of the NQR frequency. An attempt is made to compare the torsional frequencies evaluated from NQR data with those obtained by IR spectra. On selecting the appropriate mode from IR spectra, a good agreement with torsional frequency obtained from NQR data is observed. The previously mentioned approach is a good illustration of the supplementary nature of the data from IR studies, in relation to NQR studies of compounds in solid state. PMID:23161529

  1. SIMPLAG, računalni program za projekciju razvoja regularne šume: konstrukcija, struktura i primjena

    Teslak, Krunoslav; Čavlović, Jura; Božić, Mario

    2012-01-01

    Predikcija stanja šumskih resursa nezaobilazan je čimbenik u procesu planiranja gospodarenja šumama. Brojni modeli razvoja sastojina i šuma imaju zadatak predvidjeti posljedice postupaka gospodarenja i time unaprijediti proces planiranja gospodarenja. U radu je prikazana struktura računalnog programa SIMPLAG namijenjenog projekciji razvoja regularne, mješovite šume hrasta lužnjaka, simuliranjem različitih scenarija gospodarenja kao podrška za učinkovito planiranje gospodarenja. Osnovnu strukt...

  2. Herschel observations of interstellar chloronium. II - Detections toward G29.96-0.02, W49N, W51, and W3(OH), and determinations of the ortho-to-para and $^{35}$Cl/$^{37}$Cl isotopic ratios

    Neufeld, David A; Gerin, Maryvonne; Goicoechea, Javier R; Goldsmith, Paul F; Gry, Cecile; Gupta, Harshal; Herbst, Eric; Indriolo, Nick; Lis, Dariusz; Menten, Karl M; Monje, Raquel; Mookerjea, Bhaswati; Persson, Carina; Sonnentrucker, Paule; Wolfire, Mark G

    2015-01-01

    We report additional detections of the chloronium molecular ion, H$_2$Cl$^+$, toward four bright submillimeter continuum sources: G29.96, W49N, W51, and W3(OH). With the use of the HIFI instrument on the Herschel Space Observatory, we observed the $2_{12}-1_{01}$ transition of ortho-H$_2^{35}$Cl$^+$ at 781.627 GHz in absorption toward all four sources. Much of the detected absorption arises in diffuse foreground clouds that are unassociated with the background continuum sources and in which our best estimates of the $N({\\rm H_2Cl^+})/N({\\rm H})$ ratio lie in the range $(0.9 - 4.8) \\times 10^{-9}$. These chloronium abundances relative to atomic hydrogen can exceed the predictions of current astrochemical models by up to a factor of 5. Toward W49N, we have also detected the $2_{12}-1_{01}$ transition of ortho-H$_2^{37}$Cl$^+$ at 780.053 GHz and the $1_{11}-0_{00}$ transition of para-H$_2^{35}$Cl$^+$ at 485.418 GHz. These observations imply $\\rm H_2^{35}Cl^+/H_2^{37}Cl^+$ column density ratios that are consisten...

  3. Application of gas chromatography to the study of the chemical effects produced by the radiolysis and the 35Cl(n,p)35S reaction on the CCl4

    In this work the gas radiochromatography, which is essential in the hot atom chemistry is used. By means of this technique the chemical effects of the 35Cl(n,p)35S, and the radiolysis of liquid CCl4 were studied. The samples of liquid CCl4 were capsulated in cuarzo bulbs and were deaereated by several cycles of freeze and pumping in a vacuum line. The sample's irradiation was made in the Triga Mark III Salazar reactor with an approximated flux of 1012n-cm2-s-1 during ten hours. The sample's analysis was made using a gas radiochromatographer composed of a gas chromatographer, proportional flux detector and an adequate electronic system. In this form were obtained the radiochromatographics of the 35S labelled compounds possibly formed by hot atom chemistry and at the same time the hexachloroetane formed by the secondary radiolytic effect of the ionizing radiation on the CCl4 was identified. (author)

  4. Study of high energy nucleus nucleus collisions

    The CERN experiment WA80 studies ultrarelativistic heavy ion collisions by calorimetry and charged particle measurements over a large fraction of 4π. Here I want to concentrate on a closer study of nucleus nucleus collisions and recent results from the lead glass spectrometer Saphir. 6 refs., 5 figs

  5. Absolute NMR shielding scales and nuclear spin–rotation constants in 175LuX and 197AuX (X = 19F, 35Cl, 79Br and 127I)

    We present nuclear spin–rotation constants, absolute nuclear magnetic resonance (NMR) shielding constants, and shielding spans of all the nuclei in 175LuX and 197AuX (X = 19F, 35Cl, 79Br, 127I), calculated using coupled-cluster singles-and-doubles with a perturbative triples (CCSD(T)) correction theory, four-component relativistic density functional theory (relativistic DFT), and non-relativistic DFT. The total nuclear spin–rotation constants determined by adding the relativistic corrections obtained from DFT calculations to the CCSD(T) values are in general in agreement with available experimental data, indicating that the computational approach followed in this study allows us to predict reliable results for the unknown spin–rotation constants in these molecules. The total NMR absolute shielding constants are determined for all the nuclei following the same approach as that applied for the nuclear spin–rotation constants. In most of the molecules, relativistic effects significantly change the computed shielding constants, demonstrating that straightforward application of the non-relativistic formula relating the electronic contribution to the nuclear spin–rotation constants and the paramagnetic contribution to the shielding constants does not yield correct results. We also analyze the origin of the unusually large absolute shielding constant and its relativistic correction of gold in AuF compared to the other gold monohalides

  6. Herschel* Observations of Interstellar Chloronium. II. Detections toward G29.96-0.02, W49N, W51, and W3(OH), and Determinations of the Ortho-to-Para and 35Cl/37Cl Isotopic Ratios

    Neufeld, David A.; Black, John H.; Gerin, Maryvonne; Goicoechea, Javier R.; Goldsmith, Paul F.; Gry, Cecile; Gupta, Harshal; Herbst, Eric; Indriolo, Nick; Lis, Dariusz; Menten, Karl M.; Monje, Raquel; Mookerjea, Bhaswati; Persson, Carina; Schilke, Peter; Sonnentrucker, Paule; Wolfire, Mark G.

    2015-07-01

    We report additional detections of the chloronium molecular ion, H2Cl+, toward four bright submillimeter continuum sources: G29.96-0.02, W49N, W51, and W3(OH). With the use of the HIFI instrument on board the Herschel Space Observatory, we observed the {2}12-{1}01 transition of ortho-H{}235Cl+ at 781.627 GHz in absorption toward all four sources. Much of the detected absorption arises in diffuse foreground clouds that are unassociated with the background continuum sources and in which our best estimates of the N({{{H}}}2{{Cl}}+)/N({{H}}) ratio lie in the range (0.9-4.8) × {10}-9. These chloronium abundances relative to atomic hydrogen can exceed the predictions of current astrochemical models by up to a factor of 5. Toward W49N, we have also detected the {2}12-{1}01 transition of ortho-H{}237Cl+ at 780.053 GHz and the {1}11-{0}00 transition of para-H{}235Cl+ at 485.418 GHz. These observations imply {{{H}}}235Cl+/H{}237Cl+ column density ratios that are consistent with the solar system 35Cl/37Cl isotopic ratio of 3.1, and chloronium ortho-to-para ratios consistent with 3, the ratio of spin statistical weights. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  7. Photon Exchange in Nucleus-Nucleus Collisions

    Bertulani, Carlos A.

    2002-01-01

    The strong electromagnetic fields in peripheral heavy ion collisions give rise to photon-photon and photon-nucleus interactions. I present a general survey of the photon-photon and photon-hadron physics accessible in these collisions. Among these processes I discuss the nuclear fragmentation through the excitation of giant resonances, the Coulomb dissociation method for application in nuclear astrophysics, and the production of particles.

  8. ORGANIZACIJSKA STRUKTURA PODJETJA X

    Cebek, Tanja

    2010-01-01

    Svet se sooča s hitrimi in kompleksnimi spremembami, kar neposredno vpliva na delovanje podjetij in njihovo organiziranost. Podjetja se soočajo z izzivi organizacijskega okolja, kot so: globalna konkurenca, organizacijska turbulenca, elektronsko poslovanje, ustrezno ravnanje z znanjem in informacijami, z raznolikostjo svojega okolja ter z etiko in družbeno odgovornostjo. Okolje in potreba po razvoju podjetja narekujeta smer in spreminjanje organizacije podjetja. Obstoječa organizacijska re...

  9. Nucleus Driven Electronic Pulsation

    Ludwig, H; Xue, S -S

    2014-01-01

    We derive and solve by the spectral method the equations for a neutral system of ultra-relativistic electrons that are compressed to the radius of the nucleus and subject to a driving force. This driving force can be thought of as originating from a nuclear breathing mode, a possibility we discuss in detail.

  10. Enhancement of φ Mesons in Relativistic Nucleus-Nucleus Collisions

    2002-01-01

    The фmeson production in relativistic nucleus-nucleus collisions is investigated systematically usinga hadron-string cascade model LUCIAE. Within the framework of the model and relying on the collective

  11. Neutrino nucleus cross sections

    Athar, M Sajjad; Singh, S K; Vacas, M J Vicente

    2008-01-01

    We present the results of our calculation which has been performed to study the nuclear effects in the quasielastic, inelastic and deep inelastic scattering of neutrinos(antineutrinos) from nuclear targets. These calculations are done in the local density approximation. We take into account the effect of Pauli blocking, Fermi motion, Coulomb effect, renormalization of weak transition strengths in the nuclear medium in the case of the quasielastic reaction. The inelastic reaction leading to production of pions is calculated in a $\\Delta $- dominance model taking into account the renormalization of $\\Delta$ properties in the nuclear medium and the final state interaction effects of the outgoing pions with the residual nucleus. We discuss the nuclear effects in the $F_{3}^{A}(x)$ structure function in the deep inelastic neutrino(antineutrino) reaction using a relativistic framework to describe the nucleon spectral function in the nucleus.

  12. Antinucleon-nucleus interactions

    Dover, C.B.

    1987-01-01

    Recent experimental and theoretical results on anti p-nucleus interactions are reviewed. We focus on determinations of the anti p optical potential from elastic scattering, the use of (anti p, anti p') inelastic scattering to reveal aspects of the spin-isospin dependence of N anti N amplitudes, and some puzzling features of (anti p, anti n) charge exchange reactions on nuclei. 47 refs., 7 figs.

  13. Polarized Proton Nucleus Scattering

    Kopeliovich, B. Z.; Trueman, T. L.

    2000-01-01

    We show that, to a very good approximation, the ratio of the spin-flip to the non-flip parts of the elastic proton-nucleus amplitude is the same as for proton-nucleon scattering at very high energy. The result is used to do a realistic calculation of the analyzing power A_N for pC scattering in the Coulomb-nuclear interference (CNI) region of momentum transfer.

  14. Hadron nucleus interactions

    The elastic and inelastic scattering of intermediate energy (less than or equal to 1 GeV) protons by nuclei is considered first. The discussion focuses on the determination of the proton-nucleus optical potential in terms of the elementary nucleon-nucleon scattering amplitudes and the properties of the target and residual nucleus. The result is a series of terms for the optical potential. Then the interaction of pions with nuclei for energies in the neighborhood of the Δ-resonance is discussed. In this energy domain an incident pion will with high probability be absorbed by a nucleon to produce the Δ-resonance and thus form a Δ-particle hole state in the nucleus. Next, the subject of hypernuclei is taken up. The Λ hypernuclei and a recently observed Σ hypernuclei comprise situations in which the core nucleus can be probed by a baryon of roughly the same mass as a nucleon, with similar albeit not identical interactions with nucleons. But the Λ (or Σ) does not need to satisfy the Pauli exclusion principle with respect to the nucleons, and therefore can be in orbits forbidden to it if it were a nucleon. As the energy of the projectile increases, it becomes correspondingly more important to take relativistic effects into account. The importance of these effects is strikingly revealed by experiments involving the collision of ultrarelativistic hadrons, protons, pions, kaons (up to Fermilab energies) with nuclei. This phenomenon forms part of the final topic, which includes as well as the collision of relativistic heavy ion projectiles with nuclei. A nuclear Weiszaecker-Williams method developed for dealing with peripheral collisions is described. 32 figures, 10 tables

  15. 35Cl/37Cl isotope effects in 103Rh NMR of [RhCln(H2O)6−n]3−n complex anions in hydrochloric acid solution as a unique ‘NMR finger-print’ for unambiguous speciation

    Graphical abstract: 35Cl/37Cl isotope effects in 103Rh NMR as a unique ‘NMR-fingerprints’ leading to the unambiguous assignment of [RhCln(H2O)6−n]3−n (n = 3–6) complexes without reliance on accurate δ(103Rh) chemical shifts. Highlights: ► Direct 103Rh NMR (19.11 MHz) spectroscopic method of speciation of [RhCln(H2O)6−n]3−n in HCl. ► 35Cl/37Cl isotope effects in 103Rh NMR of [RhCln(H2O)6−n]3−n anions isotopologue and isotopomer induced 103Rh NMR ‘finger-print’ for unambiguous identification. ► 103Rh NMR identification of stereoisomers without a need for accurate chemical shifts. - Abstract: A detailed analysis of the 35Cl/37Cl isotope effects observed in the 19.11 MHz 103Rh NMR resonances of [RhCln(H2O)6−n]3−n complexes (n = 3–6) in acidic solution at 292.1 K, shows that the ‘fine structure’ of each 103Rh resonance can be understood in terms of the unique isotopologue and in certain instances the isotopomer distribution in each complex. These 35Cl/37Cl isotope effects in the 103Rh NMR resonance of the [Rh35/37Cl6]3− species manifest only as a result of the statistically expected 35Cl/37Cl isotopologues, whereas for the aquated species such as for example [Rh35/37Cl5(H2O)]2−, cis-[Rh35/37Cl4(H2O)2]− as well as the mer-[Rh35/37Cl3(H2O)3] complexes, additional fine-structure due to the various possible isotopomers within each class of isotopologues, is visible. Of interest is the possibility of the direct identification of stereoisomers cis-[RhCl4(H2O)2]−, trans-[RhCl4(H2O)2]−, fac-[RhCl3(H2O)3] and mer-[RhCl3(H2O)3] based on the 103Rh NMR line shape, other than on the basis of their very similar δ(103Rh) chemical shift. The 103Rh NMR resonance structure thus serves as a novel and unique ‘NMR-fingerprint’ leading to the unambiguous assignment of [RhCln(H2O)6−n]3−n complexes (n = 3–6), without reliance on accurate δ(103Rh) chemical shifts.

  16. Leukocyte nucleus segmentation and nucleus lobe counting

    Zheng Zong-Han

    2010-11-01

    Full Text Available Abstract Background Leukocytes play an important role in the human immune system. The family of leukocytes is comprised of lymphocytes, monocytes, eosinophils, basophils, and neutrophils. Any infection or acute stress may increase or decrease the number of leukocytes. An increased percentage of neutrophils may be caused by an acute infection, while an increased percentage of lymphocytes can be caused by a chronic bacterial infection. It is important to realize an abnormal variation in the leukocytes. The five types of leukocytes can be distinguished by their cytoplasmic granules, staining properties of the granules, size of cell, the proportion of the nuclear to the cytoplasmic material, and the type of nucleolar lobes. The number of lobes increased when leukemia, chronic nephritis, liver disease, cancer, sepsis, and vitamin B12 or folate deficiency occurred. Clinical neutrophil hypersegmentation has been widely used as an indicator of B12 or folate deficiency.Biomedical technologists can currently recognize abnormal leukocytes using human eyes. However, the quality and efficiency of diagnosis may be compromised due to the limitations of the biomedical technologists' eyesight, strength, and medical knowledge. Therefore, the development of an automatic leukocyte recognition system is feasible and necessary. It is essential to extract the leukocyte region from a blood smear image in order to develop an automatic leukocyte recognition system. The number of lobes increased when leukemia, chronic nephritis, liver disease, cancer, sepsis, and vitamin B12 or folate deficiency occurred. Clinical neutrophil hypersegmentation has been widely used as an indicator of B12 or folate deficiency. Results The purpose of this paper is to contribute an automatic leukocyte nuclei image segmentation method for such recognition technology. The other goal of this paper is to develop the method of counting the number of lobes in a cell nucleus. The experimental results

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

    Angular distributions of charged particles produced in 16O and 32S 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 bNA, that is mean impact parameter between the participating projectile nucleons and the center of the target nucleus

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

    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.

  19. Antineutron-nucleus annihilation

    Botta, E

    2001-01-01

    The n-nucleus annihilation process has been studied by the OBELIX experiment at the CERN Low Energy Antiproton Ring (LEAR) in the (50-400) MeV/c projectile momentum range on C, Al, Cu, Ag, Sn, and Pb nuclear targets. A systematic survey of the annihilation cross- section, sigma /sub alpha /(A, p/sub n/), has been performed, obtaining information on its dependence on the target mass number and on the incoming n momentum. For the first time the mass number dependence of the (inclusive) final state composition of the process has been analyzed. Production of the rho vector meson has also been examined. (13 refs).

  20. Neutrino-nucleus interactions

    Gallagher, H.; /Tufts U.; Garvey, G.; /Los Alamos; Zeller, G.P.; /Fermilab

    2011-01-01

    The study of neutrino oscillations has necessitated a new generation of neutrino experiments that are exploring neutrino-nuclear scattering processes. We focus in particular on charged-current quasi-elastic scattering, a particularly important channel that has been extensively investigated both in the bubble-chamber era and by current experiments. Recent results have led to theoretical reexamination of this process. We review the standard picture of quasi-elastic scattering as developed in electron scattering, review and discuss experimental results, and discuss additional nuclear effects such as exchange currents and short-range correlations that may play a significant role in neutrino-nucleus scattering.

  1. Global features of nucleus-nucleus collisions in ultrarelativistic domain

    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

  2. Higgs-Boson Production in Nucleus-Nucleus Collisions

    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.

  3. Sampling a Cometary Nucleus

    Keller, Horst Uwe; Küppers, Michael; Kuehrt, Ekkehard

    Understanding of the physics and chemistry of the proto solar nebula and the formation of our planetary system is a prime objective of planetary research. The key role of comets as witnesses of the early conditions is well established. Material, dust and condensed compounds, were stored at very low temperatures in cometary nuclei and have since been preserved. These icy grains are the source material out of which all planetary bodies formed in more or less complex processes. Analysis of this material will provide fundamental (in its original meaning) information about the proto solar nebula and the physical processes that dominated during the final stages of its collapse toward the ecliptic plane and the formation of the sun. Recent observations of comets and modelling results have shown that pristine material can be found at a few centimetres or decimetres below the surface of cometary nuclei. Comets have been visited by space probes over the last 20 years with increasing frequency. All observations and analyses show that cometary nuclei have low density, are porous, and their (surface) material has a very low tensile strength. Therefore collecting a sample from a cometary nucleus is relatively simple (simpler than from any other planetary body) and does not even require landing (touch and go). The Rosetta spacecraft is on its way to rendezvous a short period comet. The evolution of cometary activity will be followed from its onset through perihelion. The spacecraft will be operated in the near nucleus environment over several months providing extensive experience. It is now the time to conceive and prepare a comet nucleus sample return (CNSR) mission. The focus of such a mission must lie on the sampling and the return of the material. The concept of a CNSR mission will be discussed based on our understanding of cometary nuclei consolidated by the recent Stardust and Deep Impact results. Taking advantage of the easy sample collection brings a CNSR mission well

  4. DIAGEN-generator of inelastic nucleus-nucleus interaction diagrams

    Description of the program code generating inelastic nucleus-nucleus interaction diagrams is given. Probabilities of various diagram appearance are determined within the framework of Glauber approximation. The code allows one to determine cross sections of any processes and the number of spectator nucleons. 12 refs.; 2 figs

  5. Antiproton-nucleus interaction

    Cugnon, J.; Vandermeulen, J.

    The antiproton-nucleus physics is reviewed. On the experimental side, the recent results obtained at the LEAR, BNL and KEK facilities are analyzed. A brief summary of the main pp and pn experimental data is also given. The antiproton-nucleus interaction can lead to elasic, inelastic and charge exchange scattering and to annihilation. The latter is very dominant. The scattering cross-sections are usually analyzed in terms of complex potential models. The relationship between potentials, charge conjugation and Dirac phenomenology is discussed. Much emphasis is put on the dynamics of the antiproton annihilation on nuclei. The energy transfer, pion absorption and target response are analyzed within the intranuclear cascade model. Special interest is devoted to strangeness production, hypernucleus formation and possible annihilation on two nucleons. Signatures for this new process are searched in experimental data. Finally, the highly debated question of quark-gluon formation is analyzed. Cet article constitue une revue de la physique antiproton-noyau. Du point de vue expérimental, cette revue porte particulièrement sur les récents résultats obtenus à LEAR, BNL et KEK. On y a aussi inclus une mise à jour des faits expérimentaux principaux pour pp et pn. L'interaction antiproton-noyau conduit à la diffusion élastique, inélastique et d'xA9change de charge et à des processus d'annihilation. Habituellement, les expériences de diffusion sont analysées en termes de potentiels complexes. La relation entre ces potentiels, la conjugaison de charge et la phénoménologie de Dirac est discutée. On s'est particulièrement intéressé à la dynamique de l'annihilation d'antiprotons sur des noyaux. Le transfert d'énergie, l'absorption de pions et la réponse de la cible sont analysés dans le cadre du modèle de cascade intranucléaire. Certains autres points sont discutés plus en détail: la production d'étrangeté, la formation d'hypernoyaux et l'annihilation sur

  6. Neurons of human nucleus accumbens

    Sazdanović Maja

    2011-01-01

    Full Text Available Background/Aim. Nucleus accumbens is a part of the ventral striatum also known as a drug active brain region, especially related with drug addiction. The aim of the study was to investigate the Golgi morphology of the nucleus accumbens neurons. Methods. The study was performed on the frontal and sagittal sections of 15 human brains by the Golgi Kopsch method. We classified neurons in the human nucleus accumbens according to their morphology and size into four types: type I - fusiform neurons; type II - fusiform neurons with lateral dendrite, arising from a part of the cell body; type III - pyramidal-like neuron; type IV - multipolar neuron. The medium spiny neurons, which are mostly noted regarding to the drug addictive conditions of the brain, correspond to the type IV - multipolar neurons. Results. Two regions of human nucleus accumbens could be clearly recognized on Nissl and Golgi preparations each containing different predominant neuronal types. Central part of nucleus accumbens, core region, has a low density of impregnated neurons with predominant type III, pyramidal-like neurons, with spines on secondary branches and rare type IV, multipolar neurons. Contrary to the core, peripheral region, shell of nucleus, has a high density of impregnated neurons predominantly contained of type I and type IV - multipolar neurons, which all are rich in spines on secondary and tertiary dendritic branches. Conclusion. Our results indicate great morphological variability of human nucleus accumbens neurons. This requires further investigations and clarifying clinical significance of this important brain region.

  7. Formation of light particles in nucleus-nucleus collisions

    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

  8. A Monte Carlo Generator for High Energy Nucleus- Nucleus Collision

    Hassan, N. M.; El-Harby, N.; Hussein, M. T.

    1999-01-01

    A Monte Carlo simulator is presented to reproduce data of nucleus-nucleus interactions at high energies. The program is designed in a microscopic point of view, where the cascade approach is applied. Moreover, each nucleon from both the target and the projectile is followed up on the time scale along the collision time. The effect of the mean field that depends on the nuclear density is considered. Elastic and inelastic scattering are allowed for the nucleon binary collisions during the casca...

  9. Nucleus management with irrigating vectis

    Srinivasan Aravind

    2009-01-01

    The main objective in modern cataract surgery is to achieve a better unaided visual acuity with rapid post-surgical recovery and minimal surgery-related complications. Early visual rehabilitation and better unaided vision can be achieved only by reducing the incision size. In manual small incision cataract surgery (MSICS), incision is between 5.5 to 7 mm. Once the nucleus is prolapsed into the anterior chamber, it can be extracted through the tunnel. Nucleus extraction with an irrigating vect...

  10. Static polarization effects on the nucleus-nucleus potential

    The authors the nucleus-nucleus potential as a function of two variables : the distance between the centres of the nuclei R or equivalently the distance s0 between the surfaces s0 = R - R1 - R2 where Ri (i = 1,2) are the nuclear radii, and a surface thickness parameter a. The second variable was introduced in order to investigate the possibility of the polarization of the nuclei seen as a change in the thickness of the surface layer. (orig./AH)

  11. Selected Experimental Highlights from Nucleus-Nucleus Collisions at RHIC

    Huang, H Z

    2006-01-01

    Nucleus-nucleus collisions at RHIC produce high temperature and high energy density matter which exhibits partonic degrees of freedom. We will discuss measurements of nuclear modification factors for light hadrons and non-photonic electrons from heavy quark decays, which reflect the flavor dependence of energy loss of high momentum partons traversing the dense QCD medium. The hadronization of bulk partonic matter exhibits collectivity in effective partonic degrees of freedom. Nuclear collisions at RHIC provide an intriguing environment, where many constituent quark ingredients are readily available for possible formation of exotic particles through quark coalescences or recombinations.

  12. Dynamical nucleus-nucleus potential at short distances

    Jiang, Yongying; Wang, Ning; Li, Zhuxia; Scheid, Werner

    2010-01-01

    The dynamical nucleus-nucleus potentials for fusion reactions 40Ca+40Ca, 48Ca+208Pb and 126Sn+130Te are studied with the improved quantum molecular dynamics (ImQMD) model together with the extended Thomas-Fermi approximation for the kinetic energies of nuclei. The obtained fusion barrier for 40Ca+40Ca is in good agreement with the extracted fusion barrier from the measured fusion excitation function, and the depth of the fusion pockets are close to the results of time-dependent Hartree-Fock c...

  13. Nucleus management with irrigating vectis

    Srinivasan Aravind

    2009-01-01

    Full Text Available The main objective in modern cataract surgery is to achieve a better unaided visual acuity with rapid post-surgical recovery and minimal surgery-related complications. Early visual rehabilitation and better unaided vision can be achieved only by reducing the incision size. In manual small incision cataract surgery (MSICS, incision is between 5.5 to 7 mm. Once the nucleus is prolapsed into the anterior chamber, it can be extracted through the tunnel. Nucleus extraction with an irrigating vectis is a very simple technique, which combines mechanical and hydrostatic forces to express out the nucleus. This technique is time-tested with good results and more than 95% of nuclei in MSICS are extracted in this way offering all the merits of phacoemulsification with the added benefits of having wider applicability, better safety, shorter learning curve and lower cost.

  14. Anti p-nucleus interaction

    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 6Li, 12C, 16O, 18O, 40Ca, 48Ca, and 208Pb. Antiproton-proton reactions investigated antiproton-nucleus bound or resonant states in antiproton reactions with d, 6Li, 12C, 63Cu, and 209Bi. Inelastic scattering experiments investigated the spin-isospin dependence of the NN interactions. 19 refs., 1 fig., 1 tab

  15. Sinteza in struktura hidroksilamonijevih fluorosilikatov

    Kristl, Matjaž; Drofenik, Mihael; Golič, Ljubo

    2015-01-01

    Z reakcijo med trdnim ▫$NH_3OHF$▫ in raztopino ▫$H_2SiF_6$▫ smo sintetizirali novo spojino hidroksilamina s formulo ▫$(NH_3OH)_2SiF_6$▫. Pri rekristalizaciji te spojine iz vodne raztopine HF smo izločili monokristale s sestavo ▫$(NH_3OH)_2SiF_6.2H_2O$▫ Obe spojini smo karakterizirali s kemijsko in termično analizo, strukturo ▫$(NH_3OH)_2SiF_6.2H_2O$▫ smo določili z rentgensko strukturno analiza na osnovi monokristala. Spojina kristalizira monoklinsko.

  16. Organizacijska struktura Svetovne trgovinske organizacije

    Vuk, Jasmina

    2010-01-01

    Svetovna trgovinska organizacija (World Trade Organization) je mednarodna organizacija s sedežem v Ženevi. Organizacija je naslednica Splošnega sporazuma o trgovini in carinah, znanega po kratici GATT (General Agreement on Tariffs and Trade). Zadnji, osmi krog pogajanj v okviru GATT, imenovan Urugvajski krog pogajanj, je formalno pripeljal do ustanovitve WTO (1. januarja 1995). Slovenija je postala članica WTO 30. julija 1995. Cilj oziroma namen te organizacije je odstranjevanje ovir v mednar...

  17. Heavy-ion nucleus scattering

    Rahman, M A; Haque, S

    2003-01-01

    Heavy ion-nucleus scattering is an excellent laboratory to probe high spin phenomena, exotic nuclei and for the analysis of various exit channels. The Strong Absorption Model or the generalized diffraction models, which are semi-classical in nature, have been employed in the description of various heavy ion-nucleus scattering phenomena with reasonable success. But one needs to treat the deflection function (scattering angles) quantum mechanically in the Wave Mechanical picture for the appropriate description of the heavy-ion nucleus scattering phenomena. We have brought the mathematics for the cross-section of the heavy-ion nucleus scattering to an analytic expression taking account of the deflection function (scattering angles) quantum mechanically. sup 9 Be, sup 1 sup 6 O, sup 2 sup 0 Ne and sup 3 sup 2 S heavy-ion beams elastic scattering from sup 2 sup 8 Si, sup 2 sup 4 Mg and sup 4 sup 0 Ca target nuclei at various projectile energies over the range 20-151 MeV have been analysed in terms of the 2-paramet...

  18. Heavy-ion nucleus scattering

    Heavy ion-nucleus scattering is an excellent laboratory to probe high spin phenomena, exotic nuclei and for the analysis of various exit channels. The Strong Absorption Model or the generalized diffraction models, which are semi-classical in nature, have been employed in the description of various heavy ion-nucleus scattering phenomena with reasonable success. But one needs to treat the deflection function (scattering angles) quantum mechanically in the Wave Mechanical picture for the appropriate description of the heavy-ion nucleus scattering phenomena. We have brought the mathematics for the cross-section of the heavy-ion nucleus scattering to an analytic expression taking account of the deflection function (scattering angles) quantum mechanically. 9Be,16O, 20Ne and 32S heavy-ion beams elastic scattering from 28Si, 24Mg and 40Ca target nuclei at various projectile energies over the range 20-151 MeV have been analysed in terms of the 2-parameter formalism of the present quantal formulation and from the Strong Absorption Model for comparison. Typical fits are shown and the nuclear parameters obtained from the analyses of both approaches are presented. (author)

  19. Azimuthal correlation and collective behavior in nucleus-nucleus collisions

    Mali, P.; Mukhopadhyay, A., E-mail: amitabha-62@rediffmail.com; Sarkar, S. [University of North Bengal, Department of Physics (India); Singh, G. [SUNY at Fredonia, Department of Computer and Information Science (United States)

    2015-03-15

    Various flow effects of nuclear and hadronic origin are investigated in nucleus-nucleus collisions. Nuclear emulsion data collected from {sup 84}Kr + Ag/Br interaction at an incident energy of 1.52 GeV per nucleon and from {sup 28}Si + Ag/Br interaction at an incident energy of 14.5 GeV per nucleon are used in the investigation. The transverse momentum distribution and the flow angle analysis show that collective behavior, like a bounce-off effect of the projectile spectators and a sidesplash effect of the target spectators, are present in our event samples. From an azimuthal angle analysis of the data we also see a direct flow of the projectile fragments and of the produced charged particles. On the other hand, for both data samples the target fragments exhibit a reverse flow, while the projectile fragments exhibit an elliptic flow. Relevant flow parameters are measured.

  20. Azimuthal correlation and collective behavior in nucleus-nucleus collisions

    Various flow effects of nuclear and hadronic origin are investigated in nucleus-nucleus collisions. Nuclear emulsion data collected from 84Kr + Ag/Br interaction at an incident energy of 1.52 GeV per nucleon and from 28Si + Ag/Br interaction at an incident energy of 14.5 GeV per nucleon are used in the investigation. The transverse momentum distribution and the flow angle analysis show that collective behavior, like a bounce-off effect of the projectile spectators and a sidesplash effect of the target spectators, are present in our event samples. From an azimuthal angle analysis of the data we also see a direct flow of the projectile fragments and of the produced charged particles. On the other hand, for both data samples the target fragments exhibit a reverse flow, while the projectile fragments exhibit an elliptic flow. Relevant flow parameters are measured

  1. Kaonic nuclei and kaon-nucleus interactions

    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)

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

    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

  3. Pion production at 1800 in nucleus-nucleus collisions

    A survey experiment of pion production at 1800 in nucleus-nucleus collisions is presented. Beams of 1.05 GeV/A and 2.1 GeV/A protons, alphas, and carbon were used, as well as proton beams of 0.80 GeV, 3.5 GeV, and 4.89 GeV, and argon beams of 1.05 GeV/A and 1.83 GeV/A. This is the first such experiment to use the heavier beams. Targets used ranged from carbon to lead. An in-depth review of the literature, both experimental and theoretical, is also presented. The systematics of the data are discussed, and comparisons are made both with prior experiments and with the predictions of the models reviewed. The cross sections appear consistent with a simple single nucleon-nucleon collision picture, without the need for collective or other exotic effects. Suggestions for future work are made

  4. Resonances in -light nucleus systems

    K P Khemchandani; N G Kelkar; M Nowakowski; B K Jain

    2006-04-01

    We locate resonances in -light nucleus elastic scattering using the time delay method. We solve few-body equations within the finite rank approximation in order to calculate the -matrices and hence the time delay for the - 3He and - 4He systems. We find a resonance very close to the threshold in - 3 He elastic scattering, at about 0.5 MeV above threshold with a width of ∼ 2 MeV. The calculations also hint at the presence of sub-threshold states in both the cases.

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

    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)

  6. Determination of Coil Inductances Cylindrical Iron Nucleus

    Azeddine Mazouz

    2014-03-01

    Full Text Available The paper describes the investigation and development of a structure and performance characteristics of a coil iron nucleus cylindrical (C.I.N.C. The coil iron nucleus cylindrical is a nonlinear electro radio in which the moving of the nucleus in a sense or in other causes change in inductance and can reach extreme values at the superposition of nucleus and coil centers. The variation of the inductance and the degree of freedom of movement of the nucleus can lead to a device with electromechanical conversion The aim of this paper is the determination and visualization of self inductance and mutual of the (C.I.N.C based on geometric dimensions and the displacement of the nucleus.  

  7. Fluctuations and intermittency in high energy nucleus-nucleus collisions

    Fluctuations of the particle densities in semi-central collisions of 16O, 28Si and 32S nuclei with heavy components of nuclear emulsion at different primary energies are studied. Various methods of data analysis have been used, ranging from the examination of the structure in individual events, to the study of the average factorial moments and conventional correlation functions. Emphasis is put on the analysis of the average factorial moments which appear to be the most efficient tool in searching for dynamical fluctuations. Unquestionable evidence for non-statistical fluctuations is found in 16O and 32S interactions with Ag/Br targets at 200 GeV/nucleon. Specifically, I observe larger deviations of individual pseudorapidity distributions from a smooth spectrum and more frequent occurrence of narrow spikes than expected from Monte Carlo simulations based on independent emission of secondary particles. Clear intermittency signals are found in pseudorapidity and azimuthal angle distributions. Intermittency effect is also observed in two dimensions, where it has turned out to be stronger and cleaner than in one-dimensional distributions. Multiplicity distributions in the restricted phase space domains are well described by the negative binomial formula and consequently I find that factorial moments can be equivalently obtained from the parameters of the negative binomial fits. On the other hand investigation of the two-particle correlation functions in pseudorapidity provides no supporting evidence for pronounced non-statistical correlations. The occurrence of large particle-density fluctuations is expected in the presence of phase transition in ultrarelativistic nuclear collisions. Even though the obtained results can not be unambigously interpreted as an indication for quark-gluon plasma formation, nevertheless they clearly show that some collective effects are present in high energy nucleus-nucleus collisions. 84 refs. (author)

  8. An organism arises from every nucleus.

    Nurullah Keklikoglu

    2009-01-01

    The fact that, cloning using somatic cell nuclear transfer (SCNT) method has been performed, opened new horizons for cloning, and changed the way of our understanding and approach to cell and nucleus. The progress in cloning technology, brought the anticipation of the ability to clone an organism from each somatic cell nucleus. Therefore, the 'Cell Theory' is about to take the additional statement as "An organism arises from every nucleus". The development of gene targeting procedures which c...

  9. Semiclassical description of hadron-nucleus collisions

    The yield of hadron-nucleus collisions are described in terms of the data on hadron-nucleon collisions and the data on the target-nucleus size and nucleon density distribution in it. A set of hadron-nucleus collision events may be treated as an interaction of hadron beam with a slab of nuclear matter. This way, the data on hadron-nucleus collisions are considered similarly as the data obtained in absorption experiments-when the interaction of a particle beam with a slab of a material is studied. The theory of probability and statistics is the natural mathematical apparatus for such kind

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

    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

  11. Integrated Azimuthal Correlations in Nucleus-Nucleus Collisions at CERN SPS

    Grebieszkow, Katarzyna; Mrowczynski, Stanislaw

    2011-01-01

    Azimuthal correlations of particles produced in nucleus-nucleus collisions at CERN SPS are discussed. The correlations quantified by the integral measure Phi are shown to be dominated by effects of collective flow.

  12. Physical meaning of the yields from hadron-nucleon, hadron-nucleus, and nucleus-nucleus collisions observed in experiments

    A physical meaning of the outcomes from hadronic and nuclear collision processes at high energies is presented, as prompted experimentally. The fast and slow stages in hadron-nucleus collisions are distinguished. Hadrons are produced via intermediate objects observed in hadron-nucleus collisions. The intermediate objects may be treated as the groups of quarks or the quark bags. 37 refs

  13. Antibaryon-nucleus bound states

    Hrtánková, J

    2014-01-01

    We calculated antibaryon ($\\bar{B}$ = $\\bar{p}$, $\\bar{\\Lambda}$, $\\bar{\\Sigma}$, $\\bar{\\Xi}$) bound states in selected nuclei within the relativistic mean-field (RMF) model. The G-parity motivated $\\bar{B}$-meson coupling constants were scaled to yield corresponding potentials consistent with available experimental data. Large polarization of the nuclear core caused by $\\bar{B}$ was confirmed. The $\\bar{p}$ annihilation in the nuclear medium was incorporated by including a phenomenological imaginary part of the optical potential. The calculations using a complex $\\bar{p}$-nucleus potential were performed fully self-consistently. The $\\bar{p}$ widths significantly decrease when the phase space reduction is considered for $\\bar{p}$ annihilation products, but they still remain sizeable for potentials consistent with $\\bar{p}$-atom data.

  14. Nucleus accumbens receives gastric vagal inputs

    Sangeeta MEHENDALE; Jing-tian XIE; Han H AUNG; Xiong-Fei GUAN; Chun-Su YUAN

    2004-01-01

    AIM: To localize and characterize the response of single accumbal neurons to electrical stimulation of the gastric vagal fibers. METHODS: Unitary responses to electrical stimulation of the ventral and dorsal gastric vagal fibers which serve the proximal stomach were recorded extracellularly in the nucleus accumbens in anesthetized cats.RESULTS: The evoked units recorded in the nucleus accumbens consisted of phasic and tonic responses, with a mean latency of (396±43) ms. Convergence of ventral and dorsal gastric vagal inputs onto single phasic and tonic accumbal units was observed. For tonic inhibitory responses, convergence was exhibited when stimulation applied to both the ventral and dorsal gastric vagal branches resulted in a significantly longer inhibitory period than did stimulation of a single gastric vagal branch. Comparing the gastric vagally evoked accumbal unitary responses to the neuronal responses recorded in the nucleus tractus solitarius, parabrachial nucleus and hypothalamus in our previous studies, our data showed a higher percentage of single spike responses and shorter response duration's in the nucleus accumbens than in the other nuclei. This suggests that the synaptic drive from the gastric vagal inputs to the nucleus accumbens is less powerful than in the other structures. CONCLUSION: The present study localized and characterized gastric vagally evoked responses in the nucleus accumbens, which suggest that the nucleus accumbens may process gastric signals concerned with the ingestive process.

  15. Angular characteristics of pion-nucleus interaction

    In the present paper pion-nucleus interactions have been studied using nuclear emulsion technique. The investigation of these interactions is expected to provide some very useful information about the multiparticle production mechanism. Nuclear emulsion is a material which memorizes the tracks of charged particles. When a primary particle collides with a nucleus, it may interact with the nucleons of the target nucleus in two ways. In the first case, independent reactions may take place between the incident particle and the nucleons present in the target nucleus. Secondly the primary particle may interact coherently with the various nucleons of the target nucleus and the secondary particles are produced. Angular distribution of charged secondaries produced in these interactions has been studied for central collision events. Different workers have used different criterion for the selection of central collisions. We analysed the events with high shower particle multiplicity i.e., Ns ≥ 28 and call them as central collision events

  16. The retrotrapezoid nucleus and breathing.

    Guyenet, Patrice G; Stornetta, Ruth L; Abbott, Stephen B G; Depuy, Seth D; Kanbar, Roy

    2012-01-01

    The retrotrapezoid nucleus (RTN) is located in the rostral medulla oblongata close to the ventral surface and consists of a bilateral cluster of glutamatergic neurons that are non-aminergic and express homeodomain transcription factor Phox2b throughout life. These neurons respond vigorously to increases in local pCO(2) via cell-autonomous and paracrine (glial) mechanisms and receive additional chemosensory information from the carotid bodies. RTN neurons exclusively innervate the regions of the brainstem that contain the respiratory pattern generator (RPG). Lesion or inhibition of RTN neurons largely attenuates the respiratory chemoreflex of adult rats whereas their activation increases respiratory rate, inspiratory amplitude and active expiration. Phox2b mutations that cause congenital central hypoventilation syndrome in humans prevent the development of RTN neurons in mice. Selective deletion of the RTN Phox2b-VGLUT2 neurons by genetic means in mice eliminates the respiratory chemoreflex in neonates.In short, RTN Phox2b-VGLUT2 neurons are a major nodal point of the CNS network that regulates pCO(2) via breathing and these cells are probable central chemoreceptors. PMID:23080151

  17. Music and the nucleus accumbens.

    Mavridis, Ioannis N

    2015-03-01

    Music is a universal feature of human societies over time, mainly because it allows expression and regulation of strong emotions, thus influencing moods and evoking pleasure. The nucleus accumbens (NA), the most important pleasure center of the human brain (dominates the reward system), is the 'king of neurosciences' and dopamine (DA) can be rightfully considered as its 'crown' due to the fundamental role that this neurotransmitter plays in the brain's reward system. Purpose of this article was to review the existing literature regarding the relation between music and the NA. Studies have shown that reward value for music can be coded by activity levels in the NA, whose functional connectivity with auditory and frontal areas increases as a function of increasing musical reward. Listening to music strongly modulates activity in a network of mesolimbic structures involved in reward processing including the NA. The functional connectivity between brain regions mediating reward, autonomic and cognitive processing provides insight into understanding why listening to music is one of the most rewarding and pleasurable human experiences. Musical stimuli can significantly increase extracellular DA levels in the NA. NA DA and serotonin were found significantly higher in animals exposed to music. Finally, passive listening to unfamiliar although liked music showed activations in the NA. PMID:25102783

  18. Analysis of Subthreshold Antiproton Production in p-Nucleus and Nucleus-Nucleus Collisions in the RBUU Approach

    Teis, S; Maruyama, T; Mosel, U; Teis, Stefan; Cassing, Wolfgang; Maruyama, Tomoyuki; Mosel, Ulrich

    1994-01-01

    We calculate the subthreshold production of antiprotons in the Lorentz-covariant RBUU approach employing a weighted testparticle method to treat the antiproton propagation and absorption nonperturbatively. We find that the pbar differential cross sections are highly sensitive to the baryon and antiproton selfenergies in the dense baryonic environment. Adopting the baryon scalar and vector selfenergies from the empirical optical potential for proton-nucleus elastic scattering and from Dirac-Brueckner calculations at higher density rho > rho_0 we examine the differential pbar spectra as a function of the antiproton selfenergy. A detailed comparison with the available experimental data for p-nucleus and nucleus-nucleus reactions shows that the antiproton feels a moderately attractive mean-field at normal nuclear matter density rho_0 which is in line with a dispersive potential extracted from the free annihilation cross section.

  19. Nucleus accumbens stimulation in pathological obesity.

    Harat, Marek; Rudaś, Marcin; Zieliński, Piotr; Birska, Julita; Sokal, Paweł

    2016-01-01

    One of the potential treatment methods of obesity is deep brain stimulation (DBS) of nucleus accumbens. We describe the case of 19 years old woman with hypothalamic obesity. She weighted 151.4 kg before DBS and the non-surgical methods proved to be inefficient. She was treated with implantation of DBS electrode to nucleus accumbens bilaterally. Results were measured with body mass index and neuropsychological tests. Follow-up was 14 months. Fourteen months after surgery weight was 138 kg, BMI was 48.3. Neuropsychological test results were intact. The presented case supports the thesis of treatment of obesity with nucleus accumbens stimulation. PMID:27154450

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

    Selyuzhenkov, I; Rubbia, A; Di luise, S; Kowalski, S; Kaptur, E A; Kowalik, K L; Dominik, W M; Krasnoperov, A; Feofilov, G; Vinogradov, L; Johnson, S R; Mills, G B; Planeta, R J; Robert, A L; Marton, K; Messerly, B A; Puzovic, J; Bogomilov, M V; Bravar, A; Sgalaberna, D; Renfordt, R A E; Deveaux, M; Engel, R R; Grzeszczuk, A; Davis, N; Kuich, M; Lyubushkin, V; Igolkin, S; Kondratev, V; Kadija, K; Diakonos, F; Slodkowski, M A; Rauch, W H; Pistillo, C; Laszlo, A; Nakadaira, T; Hasegawa, T; Zambelli, L A; Sadovskiy, A; Morozov, S; Petukhov, O; Szuba, M K; Mathes, H; Herve, A E; Roehrich, D; Marino, A D; Wyszynski, O J; Grebieszkow, K; 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; Rondio, E; Larsen, D T; Czopowicz, T R; Seyboth, P; Turko, L; Guber, F; Marin, V; Busygina, O; Taranenko, A; Cirkovic, M; Ravonel salzgeber, M; Gazdzicki, 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; Kobayashi, T; Blondel, A P P; Hasler, A; Damyanova, A; Stroebele, H W; Rustamov, A; Posiadala, M Z; Kolesnikov, V; Andronov, E; Zimmerman, E D; Antoniou, N; Majka, Z; Veberic, D; 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; Ereditato, A; Paolone, V; Korzenev, A; Unger, M T; Wilczek, A G; Stepaniak, J M; Matulewicz, T N; Seryakov, A; Susa, T; Staszel, P P; Marcinek, A J; 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...

  1. Coherent Pion Production in Neutrino Nucleus Scattering

    Saraswat, Kapil; Kumar, Vineet; Singh, Venktesh

    2016-01-01

    In this article, we study the coherent pion production in neutrino-nucleus interaction in the resonance region using the formalism based on partially conserved axial current (PCAC) theorem which relates the neutrino-nucleus cross section to the pion-nucleus elastic cross section. The pion nucleus elastic cross section is calculated using the Glauber model in terms of pion-nucleon cross sections obtained by parameterizing the experimental data. We calculate the differential and integrated cross sections for charged current coherent pion production in neutrino carbon scattering. The results of integrated cross section calculations are compared with the measured data. Predictions for the differential and integrated cross sections for coherent pion productions in neutrino iron scattering using above formalism are also made.

  2. Large philipsite crystal as ferromanganese nodule nucleus

    Ghosh, A.K.; Mukhopadhyay, R.

    We report here the occurrence of, to date, the largest (21 x 10 x 8 mm) phillipsite crystal forming the nucleus of a diagenetically formed ferromanganese nodule from the Central Indian Ocean Basin (CIOB). Assuming an average rate of ferromanganese...

  3. Parabrachial nucleus involvement in multiple system atrophy☆

    Benarroch, E.E.; Schmeichel, A.M.; Low, P. A.; Parisi, J.E.

    2013-01-01

    Multiple system atrophy (MSA) is associated with respiratory dysfunction, including sleep apnea, respiratory dysrhythmia, and laryngeal stridor. Neurons of the parabrachial nucleus (PBN) control respiratory rhythmogenesis and airway resistance.

  4. Modified meson-nucleus optical potentials

    Wilkin, C

    1973-01-01

    The author argues that the energy dependence of the meson-nucleus optical potential should be treated in a more dynamical fashion. When this is done, some of the difficulties found in phenomenological applications are eliminated. (13 refs).

  5. The nucleus in Finland - The second report

    The Finnish Nuclear Society (FNS) started the distribution of the Nucleus bulletin at the beginning of 1988. The volume of distribution has been extended since, including today nearly 1,000 persons. Both the English and the Finnish version of the bulletin is sent to various opinion leaders of society, i.e. the members of the parliament, ministries, the media, representatives of industry and other decision-makers of the energy field. After the five-year history of the Nucleus in Finland, it is time to look back and sum up the present status of the Nucleus. This report gives a short summary concerning the present distribution and its efficiency, the experiences gained and the influence of the bulletin in Finland. The first questionnaire was sent in November 1988, and the survey was repeated among the Finnish readers of the Nucleus in autumn 1992. The results of the latter survey are given in this report

  6. Testing string dynamics in lepton nucleus reactions

    The sensitivity of nuclear attenuation of 10-100 GeV lepton nucleus (ell A) reactions to space-time aspects of hadronization is investigated within the context of the Lund string model. We consider two mechanisms for attenuation in a nucleus: final state cascading and string flip excitations. Implications for the evolution of the energy density in nuclear collisions are discussed. 16 refs., 10 figs

  7. Observation of high energy gamma rays in intermediate energy nucleus-nucleus collisions

    Beard, K.B.; Benenson, W.; Bloch, C.; Kashy, E.; Stevenson, J.; Morrissey, D.J.; Plicht, J. van der; Sherrill, B.; Winfield, J.S.

    1985-01-01

    High energy electrons and positrons observed in medium energy nucleus-nucleus collisions are shown to be primarily due to the external conversion of high energy gamma rays. The reaction 14N+Cu was studied at E/A=40 MeV, and a magnetic spectrograph was used with a specially constructed multiwire prop

  8. Investigation of the (232)Th Nucleus Excitations at the FEL {gamma} - Nucleus Colliders

    Koru, H; Sultansoy, S F; Sarer, B

    2001-01-01

    The physics search potential of the FEL {gamma} - Nucleus colliders is analysed using excitations of the (232)Th nucleus. It is shown that, due to the monochromacity of FEL {gamma} beam and high statistics, proposed colliders will play an important role in the field of "traditional" nuclear physics.

  9. Temperature measurement of quark-gluon plasma formed in high energy nucleus-nucleus collisions

    We discuss lepton pair and real photon emission from quark-gluon plasma, which is very likely to be formed in high energy nucleus-nucleus collisions. Measurement of pair production cross-section will provide one with accurate information of the temperature of this plasma. (author)

  10. Protein quality control in the nucleus.

    Jones, Ramon D; Gardner, Richard G

    2016-06-01

    The nucleus is the repository for the eukaryotic cell's genetic blueprint, which must be protected from harm to ensure survival. Multiple quality control (QC) pathways operate in the nucleus to maintain the integrity of the DNA, the fidelity of the DNA code during replication, its transcription into mRNA, and the functional structure of the proteins that are required for DNA maintenance, mRNA transcription, and other important nuclear processes. Although we understand a great deal about DNA and RNA QC mechanisms, we know far less about nuclear protein quality control (PQC) mechanisms despite that fact that many human diseases are causally linked to protein misfolding in the nucleus. In this review, we discuss what is known about nuclear PQC and we highlight new questions that have emerged from recent developments in nuclear PQC studies. PMID:27015023

  11. Direct projection from the suprachiasmatic nucleus to hypophysiotrophic corticotropin-releasing factor immunoreactive cells in the paraventricular nucleus of the hypothalamus demonstrated...

    Vrang, N.; Larsen, P.J.; Mikkelsen, J.D.

    1995-01-01

    Suprachiasmatic nucleus, paraventricular nucleus, circadian rhythms, phaseolus vulgaris-leucoagglutinin, corticotropin-releasing factor, dual immunocytochemistry......Suprachiasmatic nucleus, paraventricular nucleus, circadian rhythms, phaseolus vulgaris-leucoagglutinin, corticotropin-releasing factor, dual immunocytochemistry...

  12. Nucleus-Nucleus Potential at Near-Barrier Energies from Self Consistent Calculations

    Skalski, J

    2003-01-01

    We determine the static nucleus-nucleus potential from Hartree-Fock (HF) calculations with the Skyrme interaction. To this aim, HF equations are solved on a spatial mesh, with the initial configuration consisting of target and projectile positioned at various relative distances. For a number of reaction partners, the calculated barrier heights reasonably well compare with those extracted from the measured fusion and capture cross sections. At smaller target-projectile distances, our results show the intrinsic barriers to heavy compound nucleus formation. We speculate on their possible connection with the fusion hindrance observed for large Z sub T Z sub P.

  13. Inner Structure of Boiling Nucleus and Interfacial Energy Between Nucleus and Bulk Liquid

    WANG Xiao-Dong; TIAN Yong; PENG Xiao-Feng; WANG Bu-Xuan

    2004-01-01

    @@ A model of two-region structure of a nucleus is proposed to describe nucleus evolution. The interfacial tension between bulk liquid phase and nucleus is dependent on the density gradient in the transition region and varies with the structure change of the transition region. With the interfacial tension calculated using this model, the predicted nucleation rate is very close to the experimental measurement. Furthermore, this model and associated analysis provide solid theoretical evidence to clarify the definition of nucleation rate and understand the nucleation phenomenon with insight into the physical nature.

  14. Uncovering the nucleus candidate for NGC 253

    Günthardt, G I; Camperi, J A; Díaz, R J; Gomez, P L; Bosch, G; Schirmer, M

    2015-01-01

    NGC253 is the nearest spiral galaxy with a nuclear starburst which becomes the best candidate to study the relationship between starburst and AGN activity. However, this central region is veiled by large amounts of dust, and it has been so far unclear which is the true dynamical nucleus. The near infrared spectroscopy could be advantageous in order to shed light on the true nucleus identity. Using Flamingos-2 at Gemini South we have taken deep K-band spectra along the major axis and through the brightest infrared source. We present evidence showing that the brightest near infrared and mid infrared source in the central region, already known as radio source TH7 and so far considered just a stellar supercluster, in fact, presents various symptoms of a genuine galactic nucleus. Therefore, it should be considered a valid nucleus candidate. It is the most massive compact infrared object in the central region, located at 2.0" of the symmetry center of the galactic bar. Moreover, our data indicate that this object i...

  15. ULTRASTRUCTURE OF THE RAT MESENCEPHALIC TRIGEMINAL NUCLEUS

    LIEM, RSB; COPRAY, JCVM; VANWILLIGEN, JD

    1991-01-01

    The subcellular morphology of the mesencephalic trigeminal (Me5) nucleus in the rat was studied by transmission electron microscopy. Most neurons in the thin rostral as well as in the major caudal part of Me5 appeared as large (40-50-mu-m), round-to ovoid-shaped unipolar cells. A few neurons (estima

  16. An organism arises from every nucleus.

    Nurullah Keklikoglu

    2009-12-01

    Full Text Available The fact that, cloning using somatic cell nuclear transfer (SCNT method has been performed, opened new horizons for cloning, and changed the way of our understanding and approach to cell and nucleus. The progress in cloning technology, brought the anticipation of the ability to clone an organism from each somatic cell nucleus. Therefore, the 'Cell Theory' is about to take the additional statement as "An organism arises from every nucleus". The development of gene targeting procedures which can be applied with SCNT, showed us that it may be possible to obtain different versions of the original genetic constitution of a cell. Because of this opportunity which is provided by SCNT, in reproductive cloning, it would be possible to clone enhanced organisms which can adapt to different environmental conditions and survive. Furthermore, regaining the genetic characteristics of ancestors or reverse herediter variations would be possible. On the other hand, in therapeutic cloning, more precise and easily obtainable alternatives for cell replacement therapy could be presented. However, while producing healthier or different organisms from a nucleus, it is hard to foresee the side effects influencing natural processes in long term is rather difficult.

  17. LSP-Nucleus Elastic Scattering Cross Sections

    Vergados, J. D.; Kosmas, T. S.

    1997-01-01

    We calculate LSP-nucleus elastic scattering cross sections using some representative input in the restricted SUSY parameter space. The coherent matrix elements are computed throughout the periodic table while the spin matrix elements for the proposed $^{207}Pb$ target which has a rather simple nuclear structure. The results are compared to those given from other cold dark matter detection targets.

  18. Delta excitations in neutrino-nucleus scattering

    Kim, H; Horowitz, C J; Kim, Hungchong

    1995-01-01

    We derive the contribution of \\Delta-h excitations to quasielastic charged-current neutrino-nucleus scattering in the framework of relativistic mean-field theory. We discuss the effect of \\Delta production on the determination of the axial mass M_A in neutrino scattering experiments.

  19. Inside a plant nucleus: discovering the proteins

    Petrovská, Beáta; Šebela, M.; Doležel, Jaroslav

    2015-01-01

    Roč. 66, č. 6 (2015), s. 1627-1640. ISSN 0022-0957 R&D Projects: GA ČR(CZ) GA14-28443S; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Cell nucleus * chromatin * genome function Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.526, year: 2014

  20. Nucleon molecular orbitals and the transition mechanism between molecular orbitals in nucleus-nucleus collisions

    The molecular orbitals of the nucleon(s) in nucleus-nucleus collisions are dynamically defined as a linear combination of nucleon single-particle orbits (LCNO) in a rotating frame by using the coupled-reaction-channel (CRC) theory. Nucleon molecular orbitals and the promotions of nucleon, - especially due to the Landau-Zener radial coupling are discussed with the method above mentioned. (author)

  1. Random matrix theory and analysis of nucleus-nucleus collisions at high energies

    We propose a novel method for analysis of experimental data obtained at relativistic nucleus-nucleus collisions. The method, based on the ideas of Random Matrix Theory (RMT) is applied to detect systematic errors that occur at measurements of momentum distributions of emitted particles. The unfolded momentum distribution is well described by the Gaussian orthogonal ensemble of random matrices, when the uncertainty in the momentum distribution is maximal. The method is free from unwanted background contributions

  2. Transverse energy distributions in nucleus-nucleus collisions at 200 GeV/nucleon

    The transverse energy ET distributions of nucleus-nucleus collisions are studied in the framework of a simple geometrical model. The distributions for inclusive production of J/ψ and muon pairs in the mass continuum are analyzed. The shape of the ET distribution of the continuum agrees with the model. The previously observed decrease of the ratio (J/ψ)/continuum with increasing ET is due to the behavior of the J/ψ. (orig.)

  3. Study of -nucleus interaction through the formation of -nucleus bound state

    V Jha; B J Roy; A Chatterjee; H Machner

    2006-05-01

    The question of possible existence of -mesic nuclei is quite intriguing. 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 the GeV proton beam, currently being performed at COSY.

  4. Hypoxia activates nucleus tractus solitarii neurons projecting to the paraventricular nucleus of the hypothalamus

    King, T. Luise; Heesch, Cheryl M.; Clark, Catharine G.; Kline, David D.; Hasser, Eileen M.

    2012-01-01

    Peripheral chemoreceptor afferent information is sent to the nucleus tractus solitarii (nTS), integrated, and relayed to other brain regions to alter cardiorespiratory function. The nTS projects to the hypothalamic paraventricular nucleus (PVN), but activation and phenotype of these projections during chemoreflex stimulation is unknown. We hypothesized that activation of PVN-projecting nTS neurons occurs primarily at high intensities of hypoxia. We assessed ventilation and cardiovascular para...

  5. Systematic investigation of scaled factorial cumulant moments for nucleus-nucleus interactions

    We use scaled factorial cumulant moments to analyze pseudorapidity fluctuations in nucleus-nucleus collisions. This approach is similar to the method of scaled factorial moments except that it removes the effects of lower-order correlations upon a given moment. Significant second-order cumulants and cumulant indices (slopes with respect to bin size) are found for all of the interactions studied. These indices are found to have an inverse dependence upon average pseudorapidity particle density

  6. Centrality Dependence of Flow in High-Energy Nucleus-Nucleus Collisions

    杨红艳; 周代翠; 杨纯斌; 蔡勖

    2002-01-01

    Directed flow and elliptic flow of final state particles in high-energy nucleus-nucleus collisions in the EMU01 experiment have been studied. The dependences of directed flow and elliptic flow on incident energy and impact centrality of outgoing particles are presented. The results exhibit strong dependence of flow on centrality and energy. We also suggest a more reliable way to determine the event plane resolution here.

  7. Fusion cross sections for reactions involving medium & heavy nucleus-nucleus systems

    Atta, Debasis; Basu, D. N.

    2014-01-01

    Existing data on near-barrier fusion excitation functions of medium and heavy nucleus-nucleus systems have been analyzed using a simple diffused barrier formula derived assuming the Gaussian shape of the barrier height distributions. Fusion cross section is obtained by folding the Gaussian barrier distribution with the classical expression for the fusion cross section for a fixed barrier. The energy dependence of the fusion cross section, thus obtained, provides good description to the existi...

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

    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)

  9. Transverse momentum spectra in high-energy nucleus-nucleus, proton-nucleus and proton-proton collisions

    XIE Wen-Jie

    2011-01-01

    The transverse momentum distributions of final-state particles produced in nucleus-nucleus (AA),proton-nucleus (pA),and proton-proton (pp) collisions at high energies are investigated using a multisource ideal gas model.Our calculated results show that the contribution of hard emission can be neglected in the study of transverse momentum spectra of charged pions and kaons produced in Cu-Cu collisions at (√SNN)=22.5 GeV.And if we consider the contribution of hard emission,the transverse momentum spectra of p and (P) produced in Cu-Cu collisions at (√SNN)=22.5 GeV,KsO produced in Pb-Pb collisions at 158 A GeV,J/ψ particles produced in p-Pb collisions at 400 GeV and π+,K+,p produced in proton-proton collisions at (√S)=200 GeV,can be described by the model,especially in the tail part of spectra.

  10. Protein quality control in the nucleus

    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. The...... 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....

  11. Nuclear effects in neutrino-nucleus DIS

    Hirai, M; Saitô, K

    2009-01-01

    We explain the current status of nuclear parton distribution functions in connection with neutrino-nucleus interactions. Neutrino deep inelastic scattering (DIS) measurements have been done for heavy nuclear targets such as iron and lead. In order to extract structure functions of the nucleon, one needs to remove nuclear effects from the data. However, recent studies indicate that there are inconsistencies in nuclear modifications between charged-lepton and neutrino scattering measurements. Nuclear medium effects could be also an origin for the NuTeV anomaly in the weak-mixing angle. In addition, the modifications could affect neutrino-oscillation experiments because some DIS events of neutrino-oxygen nucleus interactions are contained. On the other hand, the nuclear medium effects themselves are interesting and important for describing nuclei in terms of quark and gluon degrees of freedom.

  12. Correlations in neutrino-nucleus scattering

    Van Cuyck, Tom; Jachowicz, Natalie; González-Jiménez, Raul; Martini, Marco; Ryckebusch, Jan; Van Dessel, Nils

    2016-01-01

    We present a detailed study of charged-current quasielastic neutrino-nucleus scattering and of the influence of correlations on one- and two-nucleon knockout processes. The quasielastic neutrino-nucleus scattering cross sections, including the influence of long-range correlations, are evaluated within a continuum random phase approximation approach. The short-range correlation formalism is implemented in the impulse approximation by shifting the complexity induced by the correlations from the wave functions to the operators. The model is validated by confronting $(e,e^\\prime)$ cross-section predictions with electron scattering data in the kinematic region where the quasielastic channel is expected to dominate. Further, the $^{12}$C$(\

  13. Coherency in Neutrino-Nucleus Elastic Scattering

    Kerman, S; Deniz, M; Wong, H T; Chen, J -W; Li, H B; Lin, S T; Liu, C -P; Yue, Q

    2016-01-01

    Neutrino-nucleus elastic scattering provides a unique laboratory to study the quantum mechanical coherency effects in electroweak interactions, towards which several experimental programs are being actively pursued. We report results of our quantitative studies on the transitions towards decoherency. A parameter ($\\alpha$) is identified to describe the degree of coherency, and its variations with incoming neutrino energy, detector threshold and target nucleus are studied. The ranges of $\\alpha$ which can be probed with realistic neutrino experiments are derived, indicating complementarity between projects with different sources and targets. Uncertainties in nuclear physics and in $\\alpha$ would constrain sensitivities in probing physics beyond the standard model. The maximum neutrino energies corresponding to $\\alpha$>0.95 are derived.

  14. Coherency in neutrino-nucleus elastic scattering

    Kerman, S.; Sharma, V.; Deniz, M.; Wong, H. T.; Chen, J.-W.; Li, H. B.; Lin, S. T.; Liu, C.-P.; Yue, Q.; Texono Collaboration

    2016-06-01

    Neutrino-nucleus elastic scattering provides a unique laboratory to study the quantum mechanical coherency effects in electroweak interactions, towards which several experimental programs are being actively pursued. We report results of our quantitative studies on the transitions towards decoherency. A parameter (α ) is identified to describe the degree of coherency, and its variations with incoming neutrino energy, detector threshold, and target nucleus are studied. The ranges of α that can be probed with realistic neutrino experiments are derived, indicating complementarity between projects with different sources and targets. Uncertainties in nuclear physics and in α would constrain sensitivities in probing physics beyond the standard model. The maximum neutrino energies corresponding to α >0.95 are derived.

  15. Nickel-48, a very magic nucleus

    Ni48, which is doubly magic and very exotic, has been observed in an experiment performed at the GANIL accelerator. This nucleus, which is composed of 20 neutrons and 28 protons, is the most neutron-deficient nucleus that can be obtained, its decay mode has not yet been determined but theory predicts a 2-proton emission. Ni48 nuclei were obtained when accelerated (75 MeV/A) Ni58 ions had undergone fragmentation on natural nickel target. During this experiment 4 nuclei of Ni48 were produced as well as other very exotic nuclei: 90 nuclei of Ni49, 50 of Fe45 and 290 of Cr42. This experiment lasted 10 days and 1017 Ni58 ions were projected on the target. (A.C.)

  16. Hadron production in the nucleus fragmentation region

    The RHIC hadron production data in hadronic collisions at the forward rapidities may hint the evidence of the Color Glass Condensate (CGC). However, in the opposite region, backward rapidities, new effects should be important in order to describe the observables. In this work, the charged hadron and π0 productions are investigated in the fragmentation region of the nucleus (backward rapidities) considering dAu and pp collisions in the context of the Color Glass Condensate. In the backward rapidity region, only the proton can be treated as a CGC, and the large x nuclear effects need to be considered in order to describe the cross section. The results are shown by means of the nuclear modification ratio comparing the proton-nucleus and proton-proton cross sections and such ratio presents some dependences on the large x nuclear effects. (author)

  17. Nucleus spectroscopy: extreme masses and deformations

    The author proposes a synthesis of research activities performed since 1995 in the field of experimental nuclear physics, and more particularly in the investigation of two nucleus extreme states: deformation on the one hand, heavy and very heavy nuclei on the other hand. After a presentation of the context of investigations on deformation, rotation, and heavy nuclei, he gives an overview of developments regarding instruments (gamma spectrometers, detection of fission fragments, and detection at the focal plane of spectrometers or separators) and analysis techniques. Experiments and results are then reported and discussed, concerning super-deformed states with a high angular moment, spectroscopy of neutron-rich nuclei, very heavy nuclei close to nucleus map borders. He finally draws perspectives for middle and long term studies on the heaviest nuclei

  18. Dropped nucleus following phacoemulsification cataract surgery.

    Tajunisah, I; Reddy, S C

    2007-12-01

    Twenty two cases of dropped nucleus following 1,196 phacoemulsification procedures in cataract surgery were examined retrospectively to determine the incidence, predisposing factors and visual outcomes of this dreaded complication. All the cases underwent pars plana vitrectomy and the lens fragments were removed with phacofragmotome, vitrectomy cutter or delivered through limbus. The incidence of dropped nucleus was 1.84%. The predisposing factors were hard cataracts (13.6%), polar cataracts (9.1%), previously vitrectomized eyes (4.5%) and high myopia (4.5%). The final visual outcome was > or = 6/12 in 10 eyes (45.5%); complications were seen in 5 eyes (22.7%). The interval between initial surgery and vitrectomy, the method of fragment removal and the type of lens implanted, did not influence the final visual outcome. PMID:18705466

  19. The fast Ice Nucleus chamber FINCH

    Bundke, U.; Nillius, B.; Jaenicke, R.; Wetter, T.; Klein, H.; Bingemer, H.

    2008-11-01

    We present first results of our new developed Ice Nucleus (IN) counter FINCH from the sixth Cloud and Aerosol Characterization Experiment (CLACE 6) campaign at Jungfraujoch station, 3571 m asl. Measurements were made at the total and the ICE CVI inlet. Laboratory measurements of ice onset temperatures by FINCH are compared to those of the static diffusion chamber FRIDGE (FRankfurt Ice Deposition Freezing Experiment). Within the errors of both new instruments the results compare well to published data.

  20. Development of a Mobile Ice Nucleus Counter

    Kok, Gregory; Kulkarni, Gourihar

    2014-07-10

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70 deg C, and a single stage system can operate the warm wall at -45 deg C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  1. Revisiting the supratrigeminal nucleus in the rat.

    Fujio, T; Sato, F; Tachibana, Y; Kato, T; Tomita, A; Higashiyama, K; Ono, T; Maeda, Y; Yoshida, A

    2016-06-01

    The supratrigeminal nucleus (Vsup), originally proposed as a premotoneuron pool in the trigeminal reflex arc, is a key structure of jaw movement control. Surprisingly, however, the location of the rat Vsup has not precisely been defined. In light of our previous cat studies, we made two hypotheses regarding the rat Vsup: (1) the Vsup is cytoarchitectonically distinguishable from its surrounding structures; (2) the Vsup receives central axon terminals of the trigeminal mesencephalic nucleus (Vmes) neurons which are primary afferents innervating muscle spindles of jaw-closing muscles and periodontal ligaments around the teeth. To test the first hypothesis, we examined the cytoarchitecture of the rat Vsup. The Vsup was identified as an area medially adjacent to the dorsomedial part of trigeminal principal sensory nucleus (Vp), and extended from the level just rostral to the caudal two-thirds of the trigeminal motor nucleus (Vmo) to the level approximately 150μm caudal to the Vmo. Our rat Vsup was much smaller and its location was considerably different in comparison to the Vsup reported previously. To evaluate the second hypothesis, we tested the distribution patterns of Vmes primary afferent terminals in the cytoarchitectonically identified Vsup. After transganglionic tracer applications to the masseter, deep temporal, and medial pterygoid nerves, a large number of axon terminals were observed in all parts of Vsup (especially in its medial part). After applications to the inferior alveolar, infraorbital, and lingual nerves, a small number of axon terminals were labeled in the caudolateral Vsup. The Vsup could also be identified electrophysiologically. After electrical stimulation of the masseter nerve, evoked potentials with slow negative component were isolated only in the Vsup. The present findings suggest that the rat Vsup can be cytoarchitectonically and electrophysiologically identified, receives somatotopic termination of the trigeminal primary afferents, and

  2. Control of nucleus accumbens activity with neurofeedback

    Greer, Stephanie M.; Trujillo, Andrew J.; Glover, Gary H.; Knutson, Brian

    2014-01-01

    The nucleus accumbens (NAcc) plays critical roles in healthy motivation and learning, as well as in psychiatric disorders (including schizophrenia and attention deficit hyperactivity disorder). Thus, techniques that confer control of NAcc activity might inspire new therapeutic interventions. By providing second-to-second temporal resolution of activity in small subcortical regions, functional magnetic resonance imaging (fMRI) can resolve online changes in NAcc activity, which can then be pres...

  3. Neutrino-nucleus reactions in supernovae

    Dzhioev Alan A.

    2016-01-01

    Full Text Available We study thermal effects on neutrino-nucleus reactions occurring under supernova conditions. The approach we use is based on the QRPA extended to finite temperature by the thermofield dynamics formalism. For the relevant supernova conditions we calculate inelastic neutrino scattering and neutrino absorption cross sections for two sample nuclei, 56Fe and 82Ge. In addition, we apply the approach to examine the rate of neutrino-antineutrino pair emission by hot nuclei.

  4. Radiative corrections to pion-nucleus bremsstrahlung

    Kaiser, N.(Physik Department T39, Technische Universität München, Garching, D-85747, Germany); Friedrich, J. M.

    2008-01-01

    We calculate the one-photon loop radiative corrections to virtual pion Compton scattering $\\pi^- \\gamma^* \\to \\pi^- \\gamma$, that subprocess which determines in the one-photon exchange approximation the pion-nucleus bremsstrahlung reaction $\\pi^- Z\\to \\pi^- Z \\gamma$. Ultraviolet and infrared divergencies of the loop integrals are both treated by dimensional regularization. Analytical expressions for the ${\\cal O}(\\alpha)$ corrections to the virtual Compton scattering amplitudes, $A(s,u,Q)$ a...

  5. Core nucleus polarization in Λ hypernuclei

    The response of the core nucleus to the Λ in a hypernucleus is studied with a local density approximation. This reproduces the energies and radii of the core nuclei as well as the Λ-single particle (s.p.) energies quite well. The polarizing effect of the Λ depends on the core response through an 'effective' compression modulus KA of the nucleus. For a certain class of energy functional, KA is found to be almost independent of the compression modulus K of the infinite nuclear matter. This indeed is a surprising result, and varies with the Hartree-Fock calculations with effective interactions. Reasons for this discrepancy are carefully examined. We consider values of K in the range ≅100-400 MeV. Furthermore, the polarizing effects also depend critically on D(ρ), the Λ binding in nuclear matter at density ρ. For only a direct ΛN force: D∝ρ and the core nucleus contracts giving rise to relatively larger core polarization. However, for a ''saturating'' D(ρ) (with a maximum at ρm0, where ρ0 is the nuclear matter equilibrium density), which is required to fit the s.p. data, the s-shell hypernuclei binding energies and the low energy Λp scattering data, which results from a ΛN force (including exchange) and ΛNN forces, there may be an expansion of the nucleus with nucleons flowing from the interior to the surface. This is shown to reduce the core polarization effects substantially (for ρm in the neighborhood of ρ0). The resulting changes in root mean square radius and core energy depend on A, but are mostly very small, justifying their general neglect

  6. Efficient nucleus detector in histopathology images.

    Vink, J P; Van Leeuwen, M B; Van Deurzen, C H M; De Haan, G

    2013-02-01

    In traditional cancer diagnosis, (histo)pathological images of biopsy samples are visually analysed by pathologists. However, this judgment is subjective and leads to variability among pathologists. Digital scanners may enable automated objective assessment, improved quality and reduced throughput time. Nucleus detection is seen as the corner stone for a range of applications in automated assessment of (histo)pathological images. In this paper, we propose an efficient nucleus detector designed with machine learning. We applied colour deconvolution to reconstruct each applied stain. Next, we constructed a large feature set and modified AdaBoost to create two detectors, focused on different characteristics in appearance of nuclei. The proposed modification of AdaBoost enables inclusion of the computational cost of each feature during selection, thus improving the computational efficiency of the resulting detectors. The outputs of the two detectors are merged by a globally optimal active contour algorithm to refine the border of the detected nuclei. With a detection rate of 95% (on average 58 incorrectly found objects per field-of-view) based on 51 field-of-view images of Her2 immunohistochemistry stained breast tissue and a complete analysis in 1 s per field-of-view, our nucleus detector shows good performance and could enable a range of applications in automated assessment of (histo)pathological images. PMID:23252774

  7. The nucleus basalis in Huntington's disease.

    Clark, A W; Parhad, I M; Folstein, S E; Whitehouse, P J; Hedreen, J C; Price, D L; Chase, G A

    1983-10-01

    The nucleus basalis of Meynert (nbM) provides most of the cholinergic input to the cerebral cortex. The loss of cortical choline acetyltransferase (CAT) activity in Alzheimer's disease (AD) and senile dementia of the Alzheimer's type (SDAT) appears to be related to a severe depopulation of the nbM in this dementia. In Huntington's disease (HD), by contrast, there is no loss of cortical CAT activity. The present quantitative study indicates that (1) there is no significant loss of neurons from the nbM in HD, and (2) that the previously described cytologic changes in the neurons of this nucleus in HD patients do not differ significantly from controls. These findings are consistent with the working hypothesis that the types of dementia associated with reductions of neocortical CAT activity are characterized by dysfunction or death of neurons in the nbM, but dementing disorders with normal neocortical CAT activity manifest no major abnormalities in this cholinergic nucleus of the basal forebrain. PMID:6225032

  8. The INTEGRAL View of the Galactic Nucleus

    Goldwurm, A; Goldoni, P; Paul, J; Terrier, R; Falanga, M; Ubertini, P; Bazzano, A; Santo, M D; Winkler, C; Parmar, A N; Kuulkers, E; Ebisawa, K; Roques, J P; Skinner, G K; Lund, N; Melia, F; Yusef-Zadeh, F

    2004-01-01

    We present the preliminary results of the observational campaign performed in 2003 to study the Galactic Nucleus with INTEGRAL. The mosaicked images obtained with the IBIS/ISGRI coded aperture instrument in the energy range above 20 keV, give a yet unseen view of the high-energy sources of this region in hard X and gamma-rays, with an angular resolution of 12'. We report on the discovery of a source, IGR J17456-2901, compatible with the instrument's point spread function and coincident with the Galactic Nucleus Sgr A* to within 0.9'. The source is visible up to 60-80 keV with a 20-100 keV luminosity at 8 kpc of 3 x 10E35 erg/s. Although we cannot unequivocally associate the new INTEGRAL source to the Galactic Nucleus, this is the first report of significant hard X-ray emission from within the inner 10' of the Galaxy and a contribution from the galactic center supermassive black hole itself cannot be excluded. Here we discuss the results obtained and the perspectives for future observations of the Galactic Nuc...

  9. Actomyosin contractility rotates the cell nucleus

    Kumar, Abhishek; Sumit, Madhuresh; Ramaswamy, Sriram; Shivashankar, G V

    2013-01-01

    The nucleus of the eukaryotic cell functions amidst active cytoskeletal filaments, but its response to the stresses carried by these filaments is largely unexplored. We report here the results of studies of the translational and rotational dynamics of the nuclei of single fibroblast cells, with the effects of cell migration suppressed by plating onto fibronectin-coated micro-fabricated patterns. Patterns of the same area but different shapes and/or aspect ratio were used to study the effect of cell geometry on the dynamics. On circles, squares and equilateral triangles, the nucleus undergoes persistent rotational motion, while on high-aspect-ratio rectangles of the same area it moves only back and forth. The circle and the triangle showed respectively the largest and the smallest angular speed. We show that our observations can be understood through a hydrodynamic approach in which the nucleus is treated as a highly viscous inclusion residing in a less viscous fluid of orientable filaments endowed with active...

  10. Struktura nukleových kyselin

    Schneider, Bohdan

    Vol. 5. Praha: Univerzita Karlova v Praze, 2012 - (Zvárová, J.; Mazura, I.), s. 13-54 ISBN 978-80-246-2150-0 Institutional research plan: CEZ:AV0Z50520701 Keywords : RNA * nucleic acid * molecular structure * crystallography Subject RIV: EB - Genetics ; Molecular Biology

  11. KONCEPCIJSKA STRUKTURA HRVATSKOG MODELA GLOBALNOG KOMUNIKACIJSKOG SUSTAVA

    Grbavac, Jacinta; GRBAVAC, Vitomir; Popović, Goran

    2010-01-01

    Korisnički info sustavi u organizacijama raznih vrsta i veličina transformiraju svoje računarske resurse iz pretežno centraliziranog u distribuirani komunikacijski sustav gotovo na svim razinama. Ova nova paradigma, u biti definira ulogu velikih kompjutora unutar velikih poslovnih asocijacija kao i njihovu integraciju na nacionalnoj razini. To je, zapravo kombinacija performansi, fleksibilnost i korisničko-prijateljski odnos s malim autonomnim korisnicima od osnovnih operacija/obrada do uslug...

  12. J/ψ production in proton-nucleus and nucleus-nucleus interactions at the CERN SPS

    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/ψ 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/ψ is anomalously suppressed with respect to the pattern observed in proton-nucleus and light ion reactions. (orig.)

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

    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

  14. Limits to the formation of hot fusion nuclei in nucleus-nucleus collisions

    The maximum temperature which can be sustained by a nucleus is discussed. Methods used to measure the temperature; values measured in fusion reactors; theoretical investigations on the value of the limiting temperature; and information about dynamical limitations on excitation energy storage in nuclei are reviewed. It is concluded that thermalized fusion nuclei are formed at temperatures up to 5 MeV for heavy systems and 6 MeV for medium mass systems. Thermal energy in central nucleus-nucleus collisions might not exceed some saturation value due to two effects: a sharing of the deposited energy into compressional and thermal energies; and a dynamical competition between thermal energy deposition and fast pre-equilibrium emission

  15. Oscillations of moments in high-energy nucleus-nucleus collisions

    杨红艳; 周代翠; 钱琬燕; 王晓荣

    2001-01-01

    The definitions of density function and moment of multiplicity distribution are introduced,and the method of moment analysis in e+ e- and proton-proton (pp) interactions is extended into nu-cleus-nucleus (AA) interactions. We analyze the data for relativistic nucleus-nucleus collisions and cal-culate the values of Hq for charged particle multiplicity distributions, by which we study systematically the dependences of Hq on incident energy, mass of colliding system, pseudorapidity interval, centrality and truncation of multiplicity. We compare the oscillation structures induced by e + e-, pp and AA inter-actions, and the comparison and analysis are carried out between experimental data and QCD predic-tion. The latest results are given in this paper.

  16. Jet Tomography of High-Energy Nucleus-Nucleus Collisions at Next-to-Leading Order

    We demonstrate that jet observables are highly sensitive to the characteristics of the vacuum and the in-medium QCD parton showers and propose techniques that exploit this sensitivity to constrain the mechanism of quark and gluon energy loss in strongly interacting plasmas. As a first example, we calculate the inclusive jet cross section in high-energy nucleus-nucleus collisions to O(αs3). Theoretical predictions for the medium-induced jet broadening and the suppression of the jet production rate due to cold and hot nuclear matter effects in Au+Au and Cu+Cu reactions at RHIC are presented.

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

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

    2001-10-21

    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.

  18. Development of silicon pixels for strangeness detection in nucleus-nucleus collisions

    Antinori, F. [CERN, European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland)]|[Dipartimento di Fisica dell`Universita and Sezione INFN, I-16146 Genoa (Italy); Barberis, D. [Dipartimento di Fisica dell`Universita and Sezione INFN, I-16146 Genoa (Italy); Beker, H. [Dipartimento di Fisica dell`Universita ``La Sapienza`` and Sezione INFN, I-00185 Rome (Italy); Beusch, W.; Campbell, M.; Cantatore, E. [CERN, European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Catanesi, M.G. [Dipartimento di Fisica dell`Universita and Sezione INFN, I-70124 Bari (Italy); Chesi, E. [CERN, European Organization for Nuclear Research, CH-1211 Genova 23 (Switzerland); Darbo, G. [Dipartimento di Fisica dell`Universita and Sezione INFN, I-70124 Bari (Italy); Di Bari, D. [Dipartimento di Fisica dell`Universita and Sezione INFN, I-70124 Bari (Italy); Di Liberto, S. [Dipartimento di Fisica dell`Universita ``La Sapienza`` and Sezione INFN, I-00185 Rome (Italy); Elia, D. [Dipartimento di Fisica dell-Universita and Sezione INFN, I-70124 Bari (Italy); Heijne, E.H.M.; Helstrup, H.; Jacholkowski, A.; Klempt, W.; Knudson, K. [CERN, European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Kralik, I. [Institute of Experimental Physics, SK-04353 Kosice (Slovakia); Lassalle, J.C. [CERN, European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Lenti, V. [Dipartimento di Fisica dell`Universita and Sezione INFN, I-70124 Bari (Italy); Lopez, L. [CERN, European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Luptak, M. [Institute of Experimental Physics, SK-04353 Kosice (Slovakia); Martinengo, P. [CERN, European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Meddi, F. [Dipartimento di Fisica dell`Universita ``La Sapienza`` and Sezione INFN, I-00185 Rome (Italy); Middelkamp, P. [CERN, European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Presented by...

    1995-07-20

    Silicon microdetectors and in particular the novel silicon pixel detectors open up the way for a comprehensive study of strangeness detection in nucleus-nucleus collisions. We outline the philosophy behind this approach, describe an application in the pixel-based heavy-ion experiment WA97, and give some preliminary results on the performance of four silicon pixels planes in the 1994 Pb beam run of WA97. We conclude with an outlook on some possible future applications of silicon pixels. {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}.

  19. Development of silicon pixels for strangeness detection in nucleus-nucleus collisions

    Silicon microdetectors and in particular the novel silicon pixel detectors open up the way for a comprehensive study of strangeness detection in nucleus-nucleus collisions. We outline the philosophy behind this approach, describe an application in the pixel-based heavy-ion experiment WA97, and give some preliminary results on the performance of four silicon pixels planes in the 1994 Pb beam run of WA97. We conclude with an outlook on some possible future applications of silicon pixels. copyright 1995 American Institute of Physics

  20. Dynamical aspects of intermediate-energy nucleus-nucleus collisions. Pt. 4

    The production of pions in intermediate energy nucleus-nucleus collisions by incoherent nucleon-nucleon collisions is studied within a microscopic quantal phase-space approach. Employing free production rates for the elementary process N+N → π+X experimental data for inclusive pion yields are approximately reproduced from 20-150 MeV/u within the first collision approximation. These results indicate that cooperative phenomena - apart from the time-dependent mean field - seem to play a minor role for energetic particle production even at very low bombarding energy. (orig.)

  1. High energy nucleus--nucleus studies at the Berkeley Bevalac. [Survey

    Schroeder, L.S.

    1976-09-01

    A survey of high-energy nucleus--nucleus experiments performed at the Berkeley Bevalac Facility is presented. Experimental results are divided into the general areas of peripheral and central collisions. Results on projectile and target fragmentation, total cross-section measurements, pion and photon production, and charged-particle multiplicities are stressed. Recently, there have been theoretical predictions concerning the possibility of observing new phenomena such as shock waves, pion condensates, or collapsed nuclear matter. Existing data relevant to some of these speculations are discussed. A brief discussion of future developments with high-energy nuclear beams is also presented. 27 figures, 1 table.

  2. Pion and Kaon Lab Frame Differential Cross Sections for Intermediate Energy Nucleus-Nucleus Collisions

    Norbury, John W.; Blattnig, Steve R.

    2008-01-01

    Space radiation transport codes require accurate models for hadron production in intermediate energy nucleus-nucleus collisions. Codes require cross sections to be written in terms of lab frame variables and it is important to be able to verify models against experimental data in the lab frame. Several models are compared to lab frame data. It is found that models based on algebraic parameterizations are unable to describe intermediate energy differential cross section data. However, simple thermal model parameterizations, when appropriately transformed from the center of momentum to the lab frame, are able to account for the data.

  3. The effect of the relative nuclear size on the nucleus-nucleus interactions

    Erofeeva, I. N.; Murzin, V. S.; Sivoklokov, S. Y.; Smirnova, L. N.

    1985-01-01

    The experimental data on the interactions of light nuclei (d, He(4), C(12)) at the momentum 4.2 GeV/cA with the carbon nuclei were taken in the 2-m propane bubble chamber. The distributions in the number of interacting nucleons, the spectra of protons, the mean energies of secondary pions and protons, the mean fractions of energy transferred to the pion and nucleon components are presented. The results of the investigation of the mechanism of nucleus-nucleus interactions can be used to calculate the nuclear cascades in the atmosphere.

  4. The cell nucleus taking centre stage. Workshop on the functional organization of the cell nucleus

    Gruenbaum, Y.; Raška, Ivan; Herrmann, H.

    2006-01-01

    Roč. 7, č. 12 (2006), s. 1211-1215. ISSN 1469-221X. [EMBO Workshop on the Functional Organization of the Cell Nucleus /3./. Prague, 05.05.2006-08.05.2006] R&D Projects: GA ČR(CZ) GA304/04/0692; GA ČR(CZ) GA304/06/1691; GA MŠk(CZ) LC535 Institutional research plan: CEZ:AV0Z50110509 Keywords : cell nucleus * nuclear dynamics * nuclear structure and disease Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 8.175, year: 2006

  5. Azimuthal correlations of hadrons and fragments in nucleus-nucleus collisions

    LI Hui-Ling

    2011-01-01

    Two-particle (two-fragment) azimuthal correlation functions are studied by using a simple formula which describes uniformly azimuthal distributions of final-state charged particles and nuclear fragments.This formula is obtained in the framework of a multi-source thermal model (or multi-source ideal gas model).The calculated results are compared and found to be in agreement with the experimental data of charged hadrons and nuclear fragments in nucleus-nucleus collisions at intermediate and high energies.

  6. Nucleus-nucleus potential, energy dissipation and mass dispersion in fusion and transfer reactions

    Washiyama, Kouhei; Ayik, Sakir

    2009-01-01

    The nucleus-nucleus potential and energy dissipation in fusion reactions are obtained from microscopic mean-field dynamics. The deduced potentials nicely reproduce the one extracted from experimental data. Energy dissipation shows a universal behaviour between different reactions. Also, the dispersion of mass distribution in transfer reaction is investigated in a stochastic mean-field dynamics. By including initial fluctuations in collective space, the description of the dispersion is much improved compared to that of mean field only. The result is consistent with the macroscopic phenomenological analysis of the experimental data.

  7. Nuclear structure and neutrino-nucleus interaction

    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 12C 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)

  8. From the nucleus discovery to DWBA

    The author presents a brief review of the main events in the field of nuclear reactions that are acknowledged as milestones because of their importance due to either experimental setting or physical interpretation. It is shown that the pace of discoveries has been strongly dependent on the technical progress in detection means at the beginning of nuclear physics and now is linked to the development of simulation means. The discovery of the neutron, the development of the Geiger counter, the theory of the compound nucleus or the first direct reactions are among these milestones

  9. Contemporary models of the atomic nucleus

    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

  10. Unveiling the nucleus of NGC 7172

    Smajić, S.; Fischer, S.; Zuther, J.; Eckart, A.

    2012-08-01

    Aims: We present the results of near-infrared (NIR) H + K European Southern Observatory SINFONI integral field spectroscopy (IFS) of the Seyfert 2 galaxy NGC 7172. We investigate the central 800 pc, concentrating on excitation conditions, morphology, and stellar content. NGC 7172 was selected from a sample of the ten nearest Seyfert 2 galaxies from the Veron-Cetty & Veron catalogue. All objects were chosen as test cases for adaptive optics (AO) assisted observations that allow a detailed study (at high spatial and spectral resolution) of the nuclear and host environments. NGC 7172 has a prominent dustlane crossing the central galaxy region from east to west, which makes it an ideal candidate to investigate the effect of obscuration by strong galactic extinction on (active) galaxies and their classification. Methods: The NIR is less influenced by dust extinction than optical light and is sensitive to the mass-dominating stellar populations. SINFONI integral field spectroscopy combines NIR imaging and spectroscopy and provides us with the opportunity to analyze several emission and absorption lines to investigate the stellar populations and ionization mechanisms over the 4″ × 4″ field of view (FOV). Results: We present emission and absorption line measurements in the central 800 pc of NGC 7172. The detection of [Si vi] and broad Paα and Brγ components are clear signs of an accreting super-massive black hole hiding behind the prominent dustlane at visible wavelengths. Hot temperatures of about 1300 K are indicative of a dusty torus in the nuclear region. Narrow components of Paα and Brγ enable us to make an extinction measurement. Our measures of the molecular hydrogen lines, hydrogen recombination lines, and [Fe ii] indicate that the excitation of these lines is caused by an active galactic nucleus. The central region of the galactic disk is predominantly inhabited by gas, dust, and an old K-M type giant stellar population. The gaseous, molecular, and

  11. A thalamic input to the nucleus accumbens mediates opiate dependence.

    Zhu, Yingjie; Wienecke, Carl F R; Nachtrab, Gregory; Chen, Xiaoke

    2016-02-11

    Chronic opiate use induces opiate dependence, which is characterized by extremely unpleasant physical and emotional feelings after drug use is terminated. Both the rewarding effects of a drug and the desire to avoid withdrawal symptoms motivate continued drug use, and the nucleus accumbens is important for orchestrating both processes. While multiple inputs to the nucleus accumbens regulate reward, little is known about the nucleus accumbens circuitry underlying withdrawal. Here we identify the paraventricular nucleus of the thalamus as a prominent input to the nucleus accumbens mediating the expression of opiate-withdrawal-induced physical signs and aversive memory. Activity in the paraventricular nucleus of the thalamus to nucleus accumbens pathway is necessary and sufficient to mediate behavioural aversion. Selectively silencing this pathway abolishes aversive symptoms in two different mouse models of opiate withdrawal. Chronic morphine exposure selectively potentiates excitatory transmission between the paraventricular nucleus of the thalamus and D2-receptor-expressing medium spiny neurons via synaptic insertion of GluA2-lacking AMPA receptors. Notably, in vivo optogenetic depotentiation restores normal transmission at these synapses and robustly suppresses morphine withdrawal symptoms. This links morphine-evoked pathway- and cell-type-specific plasticity in the paraventricular nucleus of the thalamus to nucleus accumbens circuit to opiate dependence, and suggests that reprogramming this circuit holds promise for treating opiate addiction. PMID:26840481

  12. Thermal Bremsstrahlung probing nuclear multifragmentation in nucleus-nucleus collisions around the Fermi energy

    The thermodynamical properties of nuclear matter at moderate temperatures and densities, in the vicinity of the predicted nuclear liquid-gas phase transition, are studied using as experimental probe the hard-photons (Eγ > 30 MeV) emitted in nucleus-nucleus collisions. Photon and charged-particle production in four different heavy-ion reactions (Ar36 + Au197, Ag107, Ni58, C12 at 60 A*MeV) is measured exclusively and inclusively coupling the TAPS photon spectrometer with two charged-particle and intermediate-mass-fragment detectors covering nearly 4π. We confirm that Bremsstrahlung emission in first-chance (off-equilibrium) proton-neutron collisions (pnγ) is the dominant origin of hard photons. We also firmly establish the existence of a thermal radiation component emitted in second-chance proton-neutron collisions. This thermal Bremsstrahlung emission takes place in semi-central and central nucleus-nucleus reactions involving heavy targets. We exploit this observation i) to demonstrate that thermal equilibrium is reached during the reaction, ii) to establish a new thermometer of nuclear matter based on Bremsstrahlung photons, iii) to derive the thermodynamical properties of the excited nuclear sources and, in particular, to establish a 'caloric curve' (temperature versus excitation energy), and iv) to assess the time-scales of the nuclear break-up process. (author)

  13. Prestress mediates force propagation into the nucleus

    Several reports show that the nucleus is 10 times stiffer than the cytoplasm. Hence, it is not clear if intra-nuclear structures can be directly deformed by a load of physiologic magnitudes. If a physiologic load could not directly deform intra-nuclear structures, then signaling inside the nucleus would occur only via the mechanisms of diffusion or translocation. Using a synchronous detection approach, we quantified displacements of nucleolar structures in cultured airway smooth muscle cells in response to a localized physiologic load (∼0.4 μm surface deformation) via integrin receptors. The nucleolus exhibited significant displacements. Nucleolar structures also exhibited significant deformation, with the dominant strain being the bulk strain. Increasing the pre-existing tensile stress (prestress) in the cytoskeleton significantly increased the stress propagation efficiency to the nucleolus (defined as nucleolus displacement per surface deformation) whereas decreasing the prestress significantly lowered the stress propagation efficiency to the nucleolus. Abolishing the stress fibers/actin bundles by plating the cells on poly-L-lysine-coated dishes dramatically inhibited stress propagation to the nucleolus. These results demonstrate that the prestress in the cytoskeleton is crucial in mediating stress propagation to the nucleolus, with implications for direct mechanical regulation of nuclear activities and functions

  14. Radiative corrections to pion-nucleus bremsstrahlung

    Kaiser, N

    2008-01-01

    We calculate the one-photon loop radiative corrections to virtual pion Compton scattering $\\pi^- \\gamma^* \\to \\pi^- \\gamma$, that subprocess which determines in the one-photon exchange approximation the pion-nucleus bremsstrahlung reaction $\\pi^- Z\\to \\pi^- Z \\gamma$. Ultraviolet and infrared divergencies of the loop integrals are both treated by dimensional regularization. Analytical expressions for the ${\\cal O}(\\alpha)$ corrections to the virtual Compton scattering amplitudes, $A(s,u,Q)$ and $B(s,u,Q)$, are derived with their full dependence on the (small) photon virtuality $Q$ from 9 classes of contributing one-loop diagrams. Infrared finiteness of these virtual radiative corrections is achieved (in the standard way) by including soft photon radiation below an energy cut-off $\\lambda$. In the region of low $\\pi^- \\gamma$ center-of-mass energies, where the pion-nucleus bremsstrahlung process is used to extract the pion electric and magnetic polarizabilities, we find radiative corrections up to about -3% fo...

  15. Electromagnetic transitions in the 16O nucleus

    The knowledge of mean lives, and therefore of total widths of nuclei excited states, is critical as it allows the absolute value of nuclear matrix elements to be attained, and thus information on wave functions of the involved level and of the levels reached by de-excitation of this last one. However, the total width of a level can be decomposed into a sum of partial widths which can be independently obtained by absolute efficiency measurements or by branching fraction measurements when the mean life of the studied level is known. The objective of this research thesis is therefore to determine some partial widths in the Oxygen 16 nucleus. Mean lives of the first excited levels have been experimentally measured and some electromagnetic transitions have been studied. The author comments models which are proposed for the oxygen 16 nucleus, describes the experimental techniques and the experiments mainly performed on the Strasbourg Van de Graaff accelerator, and compares the obtained results with values deduced from theoretical works

  16. NUCLEUS-CHART. Chart of the Nuclides

    Atomic Mass Data Center [Orsy (France)

    1998-05-05

    Nucleus is an interactive PC-based graphical viewer of NUBASE nuclear property data. NUBASE contains experimentally known nuclear properties, together with some values that have been estimated from extrapolation of experimental data for 3010 nuclides. NUBASE also contains data on those isomeric states that have half-lives greater than 1 millisecond; there are 669 such nuclides of which 58 have more than one isomeric state. The latest version of NUCLEUS-CHART has been corrected to include the names and the chemical symbols of the elements 104 to 109 that have been finally adopted by the Commission on Nomenclature of Inorganic Chemistry (CNIC) of the International Union of Pure and Applied Chemistry (IUPAC). They differ from those recommended by the same commission a few years before and that were widely used in the evaluations AME`95 and NUBASE`97. It results in some shuffling of the names and symbols, that may cause confusion in the near future. At AMDC we`ll be as careful as possible to try to avoid such confusion. In advance we apologize if any will occur in the future and recommend the user to always double check these few names.

  17. Energy levels in (7Li) nucleus

    The energies of the normal-parity states and positive parity states in (7Li) nucleus are calculated, using many-particle nuclear shell-model, and the harmonic oscillator-wave-functions, over the residual interaction of the Gaussian from the Serber force. Spin-orbit interactions are neglected. The kinetic energy is introduced as a variant quantity, through the variation of the harmonic oscillator parameter (r0) (r02=h/mw). Finally, we separate the ''spurious'' states (one quantum excitations of the center of mass of the nucleus) by the effect of the operator (R-i), for the coordinate of the center of mass on the different wave-functions of the ground state-configurations. The calculations show that the energy of the positive-parity states, separated into two groups; the first in the energy region (10-20 Mev) and described by the symmetries (43), (421); and the second group in the energy region (26-46 Mev) and described by the symmetries (31), (3211). 9 tabs.; 3 figs.; 64 refs

  18. A search for {phi} meson nucleus bound state using antiproton annihilation on nucleus

    Ohnishi, H., E-mail: h-ohnishi@riken.jp [RIKEN, RIKEN Nishina Center (Japan); Buehler, P.; Cargnelli, M. [Stefan-Meyer-Institut fNur subatomare Physik (Austria); Curceanu, C.; Guaraldo, C. [Laboratori Nazionali di Frascati dellf INFN (Italy); Hartmann, O. [Stefan-Meyer-Institut fNur subatomare Physik (Austria); Hicks, K. [Ohio University, Department of Physics and Astronomy (United States); Iwasaki, M. [RIKEN, RIKEN Nishina Center (Japan); Ishiwatari, T. [Stefan-Meyer-Institut fNur subatomare Physik (Austria); Kienle, P. [Technische Universiat Munchen (Germany); Marton, J. [Stefan-Meyer-Institut fuer subatomare Physik (Austria); Muto, R.; Naruki, M. [KEK (High Energy Accelerator Research Organization) (Japan); Niiyama, M. [Kyoto University, Department of Physics (Japan); Noumi, H. [Osaka University, Research Center for Nuclear Physics (Japan); Okada, S.; Vidal, A. Romero [Laboratori Nazionali di Frascati dellf INFN (Italy); Sakaguchi, A. [Osaka University, Department of Physics (Japan); Sakuma, F. [RIKEN, RIKEN Nishina Center (Japan); Sawada, S. [KEK (High Energy Accelerator Research Organization) (Japan); and others

    2012-12-15

    The mass shift of the vector mesons in nuclei is known to be a powerful tool for investigating the mechanism of generating hadron mass from the QCD vacuum. The mechanism is known to be the spontaneous breaking of chiral symmetry. In 2007, KEK-PS E325 experiment reported about 3.4 % mass reduction of the {phi} meson in medium-heavy nuclei (Cu). This result is possibly one of the indications of the partial restoration of chiral symmetry in nuclei, however, unfortunately it is hard to make strong conclusions from the data. One of the ways to conclude the strength of the {phi} meson mass shift in nuclei will be by trying to produce only slowly moving {phi} mesons where the maximum nuclear matter effect can be probed. The observed mass reduction of the {phi} meson in the nucleus can be translated as the existence of an attractive force between {phi} meson and nucleus. Thus, one of the extreme conditions that can be achieved in the laboratory is indeed the formation of a {phi}-nucleus bound state, where the {phi} meson is 'trapped' in the nucleus. The purpose of the experiment is to search for a {phi}-nucleus bound state and measure the binding energy of the system. We will demonstrate that a completely background-free missing-mass spectrum can be obtained efficiently by (p-bar, {phi}) spectroscopy together with K{sup + }{Lambda} tagging, using the primary reaction channel p-bar p {yields} {phi} {phi}. This paper gives an overview of the physics motivation and the detector concept, and explains the direction of the initial research and development effort.

  19. A search for ϕ meson nucleus bound state using antiproton annihilation on nucleus

    Ohnishi, H.; Bühler, P.; Cargnelli, M.; Curceanu, C.; Guaraldo, C.; Hartmann, O.; Hicks, K.; Iwasaki, M.; Ishiwatari, T.; Kienle, P.; Marton, J.; Muto, R.; Naruki, M.; Niiyama, M.; Noumi, H.; Okada, S.; Vidal, A. Romero; Sakaguchi, A.; Sakuma, F.; Sawada, S.; Sirghi, D.; Sirghi, F.; Suzuki, K.; Tsukada, K.; Doce, O. Vazquez; Widmann, E.; Yokkaichi, S.; Zmeskal, J.

    The mass shift of the vector mesons in nuclei is known to be a powerful tool for investigating the mechanism of generating hadron mass from the QCD vacuum. The mechanism is known to be the spontaneous breaking of chiral symmetry. In 2007, KEK-PS E325 experiment reported about 3.4 % mass reduction of the ϕ meson in medium-heavy nuclei (Cu). This result is possibly one of the indications of the partial restoration of chiral symmetry in nuclei, however, unfortunately it is hard to make strong conclusions from the data. One of the ways to conclude the strength of the ϕ meson mass shift in nuclei will be by trying to produce only slowly moving ϕ mesons where the maximum nuclear matter effect can be probed. The observed mass reduction of the ϕ meson in the nucleus can be translated as the existence of an attractive force between ϕ meson and nucleus. Thus, one of the extreme conditions that can be achieved in the laboratory is indeed the formation of a ϕ-nucleus bound state, where the ϕ meson is "trapped" in the nucleus. The purpose of the experiment is to search for a ϕ-nucleus bound state and measure the binding energy of the system. We will demonstrate that a completely background-free missing-mass spectrum can be obtained efficiently by (bar{p}, φ) spectroscopy together with K + Λ tagging, using the primary reaction channel bar{p} p rightarrow φ φ. This paper gives an overview of the physics motivation and the detector concept, and explains the direction of the initial research and development effort.

  20. Physical role for the nucleus in cell migration

    Fruleux, Antoine; Hawkins, Rhoda J.

    2016-09-01

    Cell migration is important for the function of many eukaryotic cells. Recently the nucleus has been shown to play an important role in cell motility. After giving an overview of cell motility mechanisms we review what is currently known about the mechanical properties of the nucleus and the connections between it and the cytoskeleton. We also discuss connections to the extracellular matrix and mechanotransduction. We identify key physical roles of the nucleus in cell migration.

  1. Physical role for the nucleus in cell migration.

    Fruleux, Antoine; Hawkins, Rhoda J

    2016-09-14

    Cell migration is important for the function of many eukaryotic cells. Recently the nucleus has been shown to play an important role in cell motility. After giving an overview of cell motility mechanisms we review what is currently known about the mechanical properties of the nucleus and the connections between it and the cytoskeleton. We also discuss connections to the extracellular matrix and mechanotransduction. We identify key physical roles of the nucleus in cell migration. PMID:27406341

  2. Decrease and conquer: Phacoemulsification technique for hard nucleus cataracts.

    Kim, Hong Kyun

    2009-10-01

    I describe a technique to improve the control and safety of phacoemulsification during hard nucleus cataract surgery. Whereas the goal of the conventional nucleofractis technique is complete fragmentation of the lens, the technique aims to separate the endonuclear core from the epinucleus. This is done in 3 steps: circumferential disassembly, decreasing the central nucleus volume, and conquering the remnant. The technique offers safer and more effective phacoemulsification in patients with hard nucleus cataracts. PMID:19781457

  3. Nucleus management in manual small incision cataract surgery by phacosection

    Ravindra M

    2009-01-01

    Nucleus management is critical in manual small incision cataract surgery (MSICS), as the integrity of the tunnel, endothelium and posterior capsule needs to be respected. Several techniques of nucleus management are in vogue, depending upon the specific technique of MSICS. Nucleus can be removed in toto or bisected or trisected into smaller segments. The pressure in the eye can be maintained at the desired level with the use of an anterior chamber maintainer or kept at atmospheric levels. In ...

  4. Hyperdeformed band in the 36Ar nucleus?

    Complete text of publication follows. The exotic shapes of atomic nuclei has attracted much attention recently both from the experimental and from the theoretical sides. E.g. the superdeformed (SD) shape in N = Z nuclei were observed experimentally during the last decade. In particular the SD band of the 36Ar nucleus was detected in 2000 [1]. Following the experimental observation a considerable theoretical effort has been concentrated on this band. In [2] e.g. the possible binary clusterizations of this state was studied systematically. Similar studies have been done also for the ground, and the hyperdeformed band. The latter one had been predicted from alphacluster model calculations [3]. The possible binary cluster-configurations are important not only for the better understanding of the structure of the shape isomers, but also from the viewpoint of predicting the favoured reaction channels to populate these states. This is the straightforward consequence of the close relation between the clusterization and reaction channels. (In fact, a cluster-configuration is defined by the reaction channel in which it can be observed.) One of the interesting conclusions of the work [2] was, that the hyperdeformed (HD) state of the 36Ar nucleus could be populated in the 24Mg+12C and 20Ne+16O reactions. A recent analysis of the 24Mg+12C elastic scattering [4] revealed the fact that the cross section can be described only by supposing resonances on top of the potential scattering. This very careful analysis incorporated phase-shift study, as well as Regge-pole and energy-dependent resonance calculations. The existence of five resonances have been proved, which have angular momenta 2, 4, 6, 7, 8. These states together with the resonances from the 20Ne+16O reactions seem to establish a rotational band, as shown in the upper part of Fig. 1. Its moment of inertia is in a very good agreement with that of the HD shape predicted from alpha-cluster model [3]. The similarity of the

  5. Analysis of Intermediate-Energy Nucleus-Nucleus Spallation, Fission, and Fragmentation Reactions with the LAQGSM code

    Mashnik, S. G.; Gudima, K. K.; Prael, R. E.; Sierk, A. J.

    2003-01-01

    The LAQGSM code has been recently developed at Los Alamos National Laboratory to simulate nuclear reactions for proton radiography applications. We have benchmarked our code against most available measured data both for proton-nucleus and nucleus-nucleus interactions at incident energies from 10 MeV to 800 GeV and have compared our results with predictions of other current models used by the nuclear community. Here, we present a brief description of our code and show illustrative results obta...

  6. Delta-nucleus dynamics: proceedings of symposium

    Lee, T.S.H.; Geesaman, D.F.; Schiffer, J.P. (eds.)

    1983-10-01

    The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta ..delta..(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe ..delta..-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented. (WHK)

  7. Dirac phenomenology and hyperon-nucleus interactions

    We discuss various aspects of hyperon-nucleus interactions in the relativistic mean field theory. First, characteristics of Λ, Σ and ≡ 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 fωy. Second, optical potentials for Λ and Σ 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 Λ hypernuclei. The large discrepancy between the decay rates and data suggests the need for additional meson exchanges. (authors). 62 refs.,7 figs., 6 tabs

  8. Nature of multiple-nucleus cluster galaxies

    Merritt, D.

    1984-05-01

    In models for the evolution of galaxy clusters which include dynamical friction with the dark binding matter, the distribution of galaxies becomes more concentrated to the cluster center with time. In a cluster like Coma, this evolution could increase by a factor of approximately 3 the probability of finding a galaxy very close to the cluster center, without decreasing the typical velocity of such a galaxy significantly below the cluster mean. Such an enhancement is roughly what is needed to explain the large number of first-ranked cluster galaxies which are observed to have extra ''nuclei''; it is also consistent with the high velocities typically measured for these ''nuclei.'' Unlike the cannibalism model, this model predicts that the majority of multiple-nucleus systems are transient phenomena, and not galaxies in the process of merging.

  9. Suprachiasmatic Nucleus: Cell Autonomy and Network Properties

    Welsh, David K.; Takahashi, Joseph S.; Kay, Steve A.

    2013-01-01

    The suprachiasmatic nucleus (SCN) is the primary circadian pacemaker in mammals. Individual SCN neurons in dispersed culture can generate independent circadian oscillations of clock gene expression and neuronal firing. However, SCN rhythmicity depends on sufficient membrane depolarization and levels of intracellular calcium and cAMP. In the intact SCN, cellular oscillations are synchronized and reinforced by rhythmic synaptic input from other cells, resulting in a reproducible topographic pattern of distinct phases and amplitudes specified by SCN circuit organization. The SCN network synchronizes its component cellular oscillators, reinforces their oscillations, responds to light input by altering their phase distribution, increases their robustness to genetic perturbations, and enhances their precision. Thus, even though individual SCN neurons can be cell-autonomous circadian oscillators, neuronal network properties are integral to normal function of the SCN. PMID:20148688

  10. Laser-Nucleus Interactions: The Quasiadiabatic Regime

    Pálffy, Adriana; Hoefer, Axel; Weidenmüller, Hans A

    2015-01-01

    The interaction between nuclei and a strong zeptosecond laser pulse with coherent MeV photons is investigated theoretically. We provide a first semi-quantitative study of the quasiadiabatic regime where the photon absorption rate is comparable to the nuclear equilibration rate. In that regime, multiple photon absorption leads to the formation of a compound nucleus in the so-far unexplored regime of excitation energies several hundred MeV above the yrast line. The temporal dynamics of the process is investigated by means of a set of master equations that account for dipole absorption, stimulated dipole emission, neutron decay and induced fission in a chain of nuclei. That set is solved numerically by means of state-of-the-art matrix exponential methods also used in nuclear fuel burnup and radioactivity transport calculations. Our quantitative estimates predict the excitation path and range of nuclei reached by neutron decay and provide relevant information for the layout of future experiments.

  11. High energy hadron-nucleus collision

    This is a lecture note concerning high energy hadron-nucleus collision. The lecture gives the inelastic total cross section and the Glanber approximate multiple scattering formula at first. The mechanism of nuclear spallation is described in a cylindrical image. The multiplicity, the one particle distribution and the time-space structure of particle production are discussed. Various models are presented. The attenuation of forward particles and the structure of hadrons are discussed for each model. The atomic number (A) dependence of the production of large transverse momentum particles and jet, and the A dependence of charged multiplicity are presented. The backward production of particles and many body correlation are discussed. Lepton pair production and the initial interaction of constituents, collective interaction, multi quark state and phase transition are described. (Kato, T.)

  12. Retrotrapezoid nucleus, respiratory chemosensitivity and breathing automaticity

    Guyenet, Patrice G.; Bayliss, Douglas A.; Stornetta, Ruth L.; Fortuna, Michal G.; Abbott, Stephen B.; Depuy, Seth D.

    2009-01-01

    SUMMARY Breathing automaticity and CO2 regulation are inseparable neural processes. The retrotrapezoid nucleus (RTN), a group of glutamatergic neurons that express the transcription factor Phox2b, may be a crucial nodal point through which breathing automaticity is regulated to maintain CO2 constant. This review updates the analysis presented in prior publications. Additional evidence that RTN neurons have central respiratory chemoreceptor properties is presented but this is only one of many factors that determine their activity. The RTN is also regulated by powerful inputs from the carotid bodies and, at least in the adult, by many other synaptic inputs. We also analyze how RTN neurons may control the activity of the downstream central respiratory pattern generator. Specifically, we review the evidence which suggests that RTN neurons a) innervate the entire ventral respiratory column, and b) control both inspiration and expiration. Finally, we argue that the RTN neurons are the adult form of the parafacial respiratory group in neonate rats. PMID:19712903

  13. Delta-nucleus dynamics: proceedings of symposium

    The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta Δ(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe Δ-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented

  14. Electron-Nucleus Collisions at THERA

    Frankfurt, L L; McDermott, M; Strikman, M I

    2001-01-01

    The nuclear option at THERA provides an ideal and unique opportunity to investigate the black body limit (BBL) of high energy Deep Inelastic Scattering of highly virtual photons off heavy nuclear targets and thereby probe QCD in a new regime. At high enough energies, whichever hadronic configuration the photon fluctuates into, the interaction at a given impact parameter with the heavy nuclear target will eventually reach its geometrical limit corresponding to the scattering from a black disk. An attractive feature of the BBL regime for a large nucleus is that the interaction is strong although the coupling constant is small. Predictions for longitudinal and transverse distributions of the leading hadrons in inclusive and diffractive channels and exclusive vector meson production are found to be strikingly different in BBL and the leading twist approximation. In particular, the multiplicity of leading hadrons in the current fragmentation region is strongly suppressed, while the cross section of diffractive vec...

  15. Total inclusive neutron cross sections and multiplicities in nucleus-nucleus collisions at intermediate energies

    The total integrated inclusive cross section, sigma(T>T0), for the emission of neutrons above an energy T0 by neon ions with an average energy of 337 MeV per nucleon reacting in targets of uranium, copper, aluminum, and carbon is described by sigma-bar/sub NN/(R-bar/sub G//r/sub o/)/sup( alphaT/o). Here sigma-bar/sub NN/ is the isospin-averaged nucleon-nucleon cross section evaluated at an energy equal to the bombarding energy per nucleon, and R-bar/sub G/ is the arithmetic mean value of the radii of the projectile and the target measured in units of the radius parameter r0 ( = 1.2 fm). In the limit T0 = 0, the exponent α(T0) = 5. A useful formula is derived for calculating mean neutron multiplicities in nucleus-nucleus collisions

  16. Production of cold fragments in nucleus-nucleus collisions in the Fermi-energy domain

    Veselsky, M

    2007-01-01

    The reaction mechanism of nucleus-nucleus collisions at projectile energies around the Fermi energy is investigated with emphasis on the production of fragmentation-like residues. The results of simulations are compared to experimental mass distributions of elements with Z = 21 - 29 observed in the reactions 86Kr+124,112Sn at 25 AMeV. The model of incomplete fusion is modified and a component of excitation energy of the cold fragment dependent on isospin asymmetry is introduced. The modifications in the model of incomplete fusion appear consistent with both overall model framework and available experimental data. A prediction is provided for the production of very neutron-rich nuclei using a secondary beam of 132Sn where e.g. the reaction 132Sn+238U at 28 AMeV appears as a possible alternative to the use of fragmentation reactions at higher energies.

  17. Experimental and phenomenological investigations of QCD matter in high-energy nucleus-nucleus collisions

    This thesis is heterogeneous, comprising experimental papers at low energies (SIS-18 at GSI) and at the LHC, papers on phenomenology of high-energy nucleus-nucleus collisions, and papers on detectors. The overview covers the experimental papers and those on phenomenology. I have chosen to write it in a general manner, intended to be accessible to non-experts. It emphasizes recent measurements and their understanding at the LHC. The detector papers, which address many principle aspects of gaseous detectors, are summarized and placed in context in the review I co-wrote and which closes the stack. The detector papers included here are the outcome of an R and D program for the Transition Radiation Detector of ALICE.

  18. Experimental and phenomenological investigations of QCD matter in high-energy nucleus-nucleus collisions

    Andronic, Anton

    2014-07-15

    This thesis is heterogeneous, comprising experimental papers at low energies (SIS-18 at GSI) and at the LHC, papers on phenomenology of high-energy nucleus-nucleus collisions, and papers on detectors. The overview covers the experimental papers and those on phenomenology. I have chosen to write it in a general manner, intended to be accessible to non-experts. It emphasizes recent measurements and their understanding at the LHC. The detector papers, which address many principle aspects of gaseous detectors, are summarized and placed in context in the review I co-wrote and which closes the stack. The detector papers included here are the outcome of an R and D program for the Transition Radiation Detector of ALICE.

  19. Nonmonotonic Target Excitation Dependence of Pion Clans in Relativistic Nucleus-Nucleus Collisions

    Ghosh, Dipak; Deb, Argha; Dutta, Srimonti

    Target excitation dependence of fluctuation of produced pions (i.e. classifying data of the fluctuation pattern on pions on the basis of the number of gray tracks) is studied for nucleus-nucleus collisions at different projectile energies. In each set the experimental multiplicity distribution is compared with the negative binomial distribution (NBD), which is found to describe the experimental distribution quite well. Target excitation dependence is studied in respect of the clan model parameters bar {n}c and bar {N}, which are extracted from the NBD fit parameters bar {n} and k. A detailed comparison between different interactions at the same energy and the same interactions at different energies is also drawn. A nonmonotonic dependence of D2/bar {n} on is revealed, which is also a characteristic of multiplicity fluctuations at RHIC data.

  20. Nuclear Effects in Neutrino-Nucleus Interactions and the MINERvA Neutrino Nucleus Scattering Program

    Nuclear effects of charged current deep inelastic neutrino-iron scattering have been studied in the frame-work of a χ2 analysis of parton distribution functions (PDFs)1. A set of iron PDFs have been extracted which are then used to compute xBj-dependent and Q2-dependent nuclear correction factors for iron structure functions which are required in global analyses of free nucleon PDFs. Upon comparing our results with nuclear correction factors from neutrino-nucleus scattering models and correction factors for l±-iron scattering we find that, except for very high xBj, our correction factors differ in both shape and magnitude from the correction factors of the models and charged-lepton scattering. The MINERvA neutrino-nucleus scattering experiment at Fermilab, will systematically study neutrino nuclear effects off of He, C, Fe and Pb for a more thorough A-dependent study of nuclear PDFs and these correction factors.

  1. Dissipation and fluctuation of the relative momentum in nucleus-nucleus collisions

    The dissipation of the relative momentum in nucleus-nucleus collisions is treated in terms of a Langevin equation with a fluctuating force. Equations of motion for first and second moments of the macroscopic variables are derived directly from the Langevin equation. The properties of the fluctuating force which results from random particle exchange are investigated in detail. Drift and diffusion coefficients are calculated microscopically and analytical expressions are given which can be used in any trajectory calculation. An important feature of the model is that the Einstein relation between dissipation and fluctuation turns out to be only a limiting case of a more general expression which included nonthermal fluctuations. By treating the two nuclei as intrinsically equilibrated but not in thermal equilibrium with respect to each other several important aspects of the dissipative behaviour, seen in heavy ion collisions with final energies above the Coloumb barrier, can be understood. (orig.)

  2. Study of Strange and Multistrange Particles in Ultrarelativistic Nucleus-Nucleus Collisions

    Vande vyvre, P; Feofilov, G; Snoeys, W; Hetland, K F; Campbell, M; Klempt, W

    2002-01-01

    % NA57\\\\ \\\\ The goal of the experiment is to study the production of strange and multi-strange particles in nucleus-nucleus collisions. This study was initiated at the OMEGA spectrometer, where three ion experiments have been performed: WA85 (S-W and p-W collisions at 200 A GeV/c), WA94 (S-S and p-S collisions at 200 A GeV/c) and WA97 (Pb-Pb, p-Pb and p-Be collisions at 160 A GeV/c).\\\\ \\\\ The experiment aims at extending the scope of WA97 by:\\\\ \\\\ - investigating the beam energy dependence of the enhancements of multi-strange particle production reported by the previous experiments, and by\\\\ \\\\\\\\ \\\\- measuring the yields of strange and multi-strange particles over an extended centrality range compared with the previous experiments.\\\\ \\\\ The apparatus consists mainly of silicon pixel detector planes.

  3. Recent Developments in the Study of Deconfinement in Nucleus-Nucleus Collisions

    Gazdzicki, M; Seyboth, P

    2014-01-01

    Deconfinement refers to the creation of a state of quasi-free quarks and gluons in strongly interacting matter. Model predictions and experimental evidence for the onset of deconfinement in nucleus-nucleus collisions were discussed in our first review on this subject. These results motivated further experimental and theoretical studies. This review addresses two subjects. First, a summary of the past, present and future experimental programmes related to discovery and study of properties of the onset of deconfinement are %briefly presented. Second, recent progress is reviewed on analysis methods and preliminary experimental results for new strongly intensive fluctuation measures are discussed, which are relevant for current and future studies of the onset of deconfinement and searches for the critical point of strongly interacting matter

  4. Stopping in high energy nucleus-nucleus collisions in the RQMD-approach

    The most intensely studied questions of today's high energy nuclear physics is that of the transition of normal nuclear matter to a quark gluon plasma state (QGP). The phase transition should occur in probes of nuclear matter of very high temperature and density. It is generally believed that these circumstances should preferentially occur in collisions of heavy nuclei with high energies. This question is considered giving a hint to the direction which has to be taken first in order to obtain answers to the question of QGP. The behaviour of two large nuclei which collide with high relative momentum is investigated. Comparisons are shown between RQMD and CERN-SPS experiments and it was found that the RQMD calculations of nucleus-nucleus collisions are in nearly perfect agreement with the available experimental data. (R.P.) 17 refs.; 6 figs

  5. Jet energy loss and bulk parton collectivity in nucleus-nucleus collisions at RHIC

    HUANG Huan-Zhong

    2009-01-01

    Nucleus-nucleus collisions at RHIC produce high temperature and high energy density matter which exhibits paxtonic degrees of freedom. We will discuss measurements of nuclear modification factors for light hadrons and non-photonic electrons from heavy quark decays, which reflect the flavor dependence of energy loss of high momentum partons traversing the dense QCD medium. The dense QCD medium responds to energy loss of high momentum patrons in a pattern consistent with that expected from a hydrodynamic fluid. The hadronization of bulk partonic matter exhibits collectivity with effective partonic degrees of freedom. Nuclear collisions at RHIC provide an intriguing environment, where many constituent quark ingredients are readily available for possible formation of exotic particles through quark coalescence or recombinations.

  6. Nucleus -nucleus interactions at a few GeV/C per nucleon

    Introduction: Since the period of the ancient Egyptians people are looking for unusual phenomena, which may enable to give interpretation for nature. Physicists believe that the study of A-A interactions will shed light on the mechanism of high-energy nuclear interactions. It is important to systematize the results of nucleus-nucleus interactions and to have an overall picture of cross-section, multiplicity-distributions, angular distributions, etc It is important to systematize the results of nucleus-nucleus interactions and to have an overall picture of: cross-section, multiplicity-distributions, angular distributions, etc Beams: Beams are mainly from Dubna Synchrophasotron including 1H, 2H, 3He, 4He, 12C, 160,22Ne, 24Mg, 28Si and 32S at 4.1∼ 4.5 GeV/c. Experimental Technique: Stacks of Br-2 emulsion were exposed to 4.1- 4.5 A GeV/c nuclei at Dubna Synchrophasotron. The pellicles of emulsion have the dimensions of 20 cm x 10 cm x 600 μm (undeveloped emulsion). The intensity of the beam was ≡104 particles/cm2 and the beam diameter was approximately 1 cm. The emitted particles are classified to:Shower tracks producing s-particleshaving a relative ionization I*≤ 1.4. Its multiplicity is denoted by ns after the exclusion of tracks having an emission angle θ≤3ο.Grey tracks producing g-particleshaving I* > 1.4 and L>3 mm. Its multiplicity is denoted by ng and does not include those tracks with an emission angle θ≤ 3ο. Black tracks producing b-particleshaving L b and does not include those tracks having an angle of emission θ≤3ο.The band gtracks are both called heavily ionizing tracks producing h-particlesand nh denotes its multiplicity

  7. The Confined Hydrogen Atom with a Moving Nucleus

    Fernandez, Francisco M.

    2010-01-01

    We study the hydrogen atom confined to a spherical box with impenetrable walls but, unlike earlier pedagogical articles on the subject, we assume that the nucleus also moves. We obtain the ground-state energy approximately by means of first-order perturbation theory and show that it is greater than that for the case in which the nucleus is clamped…

  8. A Frame Nucleus on a Two-side Prequantale

    XUShao-xian; WANGShun-qin; MAFei-fei

    2004-01-01

    In this paper, a Frame nucleus and prime elements in a Prequantale are defined. The concrete structure of a Frame prequantic quotient is considered, and the relation between the half-prime element and the Frame nucleus in a two-side Prequantale are obtained.

  9. The new magic nucleus 96Zr

    The 96Zr nucleus is expected to be magic due to the subshell closures at Z = 40 and N = 56. Recent gamma-spectroscopic studies involving in-beam techniques and beta decay certainly revealed a remarkably simple level pattern consisting of the 1,750 keV 2+ - 2,439 keV 3+ doublet, a few levels decaying to the 3- octupole state by strong E1 or E2 transitions, and a band built on the shape isomeric first excited 0+ state. While quadrupole vibrational collectivity is restricted to this latter intruder band the octupole mode is expected to be strong, according to systematics and an earlier lifetime result for the 3- state. since low-lying particle-hole excitations, and a strong octupole mode in particular, are typical for magic nuclei like 208Pb it is important to test to what extent 96Zr resembles the well known magic nuclei. In this paper, inelastic deuteron scattering and RPA studies show that the lowest states of doubly closed subshell 96Zr are particle-hole excitations, the first 2+ state being a neutron excitation of 3s1/2 2d5/2-1 type. The octupole collectively is enhanced by a factor of about two with respect to 90Zr due mainly to the contribution of 1h1 1/2 2d5/2-1 neutron excitations, suggesting an unusually high B(E3) value

  10. 34Si: a new doubly magic nucleus

    The 34Al β decay was studied at the CERN on-line mass separator ISOLDE. Gamma-ray singles, β-γ, and β-γ-γ coincidence measurements, were registered with two 80% Ge detectors. A 34Al β-decay scheme to 34Si bound states is established. The first level scheme in 34Si includes three levels at 3327.7 ± 0.5, 4257.3 ± 0.4 and 4382.7 ± 0.7 keV with respectively a Jπ assignment of 2+, 3- and (4,5)-. The 34Si level scheme is consistent with the assignment of Jπ=4- for the34Al ground state. The value of P1n=0.27(5) has been deduced for the β-delayed 1n emission of 34Al. The 34Si level scheme is found to agree with the present shell-model predictions. In the resulting picture, 34Si appears to be a new doubly magic nucleus

  11. The Chemical Evolution of Starburst Nucleus Galaxies

    Coziol, R; Davoust, E; Considère, S

    1997-01-01

    The metallicities derived from spectroscopic observations of a sample of Starburst Nucleus Galaxies (SBNGs) are compared to those of several other types of galaxies (normal giant galaxies, Irregular and HII galaxies) drawn from the literature. The SBNGs are deficient in metals with respect to normal galaxies of same morphological type, suggesting that - SBNGs are galaxies still in the process of formation. Breaking the SBNGs into early-types (Sb and earlier) and late-types reveals that the former seem to follow the same linear luminosity-metallicity relation as the irregular and elliptical galaxies, whereas the latter and the giant spirals show comparable (0.2 and 0.3 dex) excess abundances with respect to the linear relation. This difference between the two types of SBNGs is consistent with the predictions of the model of hierarchical formation of galaxies: the early-type SBNGs are building their bulges by successive mergers of small stellar and gaseous systems, while the late-type SBNGs are mostly accreting...

  12. Spontaneous fission of superheavy nucleus $^{286}$Fl

    Poenaru, Dorin N

    2016-01-01

    The decimal logarithm of spontaneous fission half-life of the superheavy nucleus $^{286}$Fl experimentally determined is $\\log_{10} T_f^{exp} (s) = -0.632$. We present a method to calculate the half-life based on the cranking inertia and the deformation energy, functions of two independent surface coordinates, using the best asymmetric two center shell model. In the first stage we study the statics. At a given mass asymmetry up to about $\\eta=0.5$ the potential barrier has a two hump shape, but for larger $\\eta$ it has only one hump. The touching point deformation energy versus mass asymmetry shows the three minima, produced by shell effects, corresponding to three decay modes: spontaneous fission, cluster decay and $\\alpha$~decay. The least action trajectory is determined in the plane $(R,\\eta)$ where $R$ is the separation distance of the fission fragments and $\\eta$ is the mass asymmetry. We may find a sequence of several trajectories one of which gives the least action. The parametrization with two deforma...

  13. Functional network inference of the suprachiasmatic nucleus.

    Abel, John H; Meeker, Kirsten; Granados-Fuentes, Daniel; St John, Peter C; Wang, Thomas J; Bales, Benjamin B; Doyle, Francis J; Herzog, Erik D; Petzold, Linda R

    2016-04-19

    In the mammalian suprachiasmatic nucleus (SCN), noisy cellular oscillators communicate within a neuronal network to generate precise system-wide circadian rhythms. Although the intracellular genetic oscillator and intercellular biochemical coupling mechanisms have been examined previously, the network topology driving synchronization of the SCN has not been elucidated. This network has been particularly challenging to probe, due to its oscillatory components and slow coupling timescale. In this work, we investigated the SCN network at a single-cell resolution through a chemically induced desynchronization. We then inferred functional connections in the SCN by applying the maximal information coefficient statistic to bioluminescence reporter data from individual neurons while they resynchronized their circadian cycling. Our results demonstrate that the functional network of circadian cells associated with resynchronization has small-world characteristics, with a node degree distribution that is exponential. We show that hubs of this small-world network are preferentially located in the central SCN, with sparsely connected shells surrounding these cores. Finally, we used two computational models of circadian neurons to validate our predictions of network structure. PMID:27044085

  14. Functional network inference of the suprachiasmatic nucleus

    Abel, John H.; Meeker, Kirsten; Granados-Fuentes, Daniel; St. John, Peter C.; Wang, Thomas J.; Bales, Benjamin B.; Doyle, Francis J.; Herzog, Erik D.; Petzold, Linda R.

    2016-04-04

    In the mammalian suprachiasmatic nucleus (SCN), noisy cellular oscillators communicate within a neuronal network to generate precise system-wide circadian rhythms. Although the intracellular genetic oscillator and intercellular biochemical coupling mechanisms have been examined previously, the network topology driving synchronization of the SCN has not been elucidated. This network has been particularly challenging to probe, due to its oscillatory components and slow coupling timescale. In this work, we investigated the SCN network at a single-cell resolution through a chemically induced desynchronization. We then inferred functional connections in the SCN by applying the maximal information coefficient statistic to bioluminescence reporter data from individual neurons while they resynchronized their circadian cycling. Our results demonstrate that the functional network of circadian cells associated with resynchronization has small-world characteristics, with a node degree distribution that is exponential. We show that hubs of this small-world network are preferentially located in the central SCN, with sparsely connected shells surrounding these cores. Finally, we used two computational models of circadian neurons to validate our predictions of network structure.

  15. Antiproton-nucleus interaction: review of the experimental situation

    This paper will review the experimental situation of a few well-defined channels of the anti-p-nucleus interaction where the antiproton does not annihilate. It will not mention any experiment which studies annihilation of antiporotons in nuclei. The anti-p-nucleus reactions that will be reviewed are the following: 1. A(anti-p,anti-p)A elastic scattering which deals with the anti-p-nucleus system in a positive energy state. 2. Anti-p-nucleus atoms where the anti-p-nucleus system is almost at zero energy and interacts mostly through the Coulomb interaction, the strong interaction being only a perturbation. 3. A(anti-p,p)X proton knock-out reaction used to produce possible bound states or resonances of the anti-p-nucleus system via strong interaction. The main reasons for studying these three channels are to provide information about the anti-p-nucleus optical potential and also, through microscopic calculations which use the elementary anti-NN amplitudes and the nuclear matter densities as inputs, to get information about these quantities. 4. A(anti-p,anti-p')A* inelastic scattering - inelastic in the sense that the nucleus is left in an excited state but the antiproton does not annihilate, that is it deals only with the elastic part of the elementary anti-NN amplitude. Inelastic scattering from collective states also sets constraints on the anti-p-nucleus potential when analysed in terms of coupled-channel calculations. When unnatural parity states are concerned, it provides a sensitive test of the spin and isospin components of these amplitudes. In addition, this paper will focus essentially on the recent experiments performed at LEAR

  16. Gluon production from non-Abelian Weizsaecker-Williams fields in nucleus-nucleus collisions

    Kovner, A.; McLerran, L.; Weigert, H. [School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    1995-12-01

    We consider the collisions of large nuclei using the theory of McLerran and Venugopalan. The two nuclei are ultrarelativistic and sources of non-Abelian Weizseacker-Williams fields. These sources are in the end averaged over all color orientations locally with a Gaussian weight. We show that there is a solution of the equations of motion for the two nucleus scattering problem where the fields are time and rapidity independent before the collision. After the collision the solution depends on proper time, but is independent of rapidity. We show how to extract the produced gluons from the classical evolution of the fields.

  17. Nonthermal Fluctuations and Mechanics of the Active Cell Nucleus

    Smith, K; Byrd, H; MacKintosh, F C; Kilfoil, M L

    2013-01-01

    We present direct measurements of fluctuations in the nucleus of yeast cells. While prior work has shown these fluctuations to be active and non-thermal in character, their origin and time dependence are not understood. We show that nuclear fluctuations can be quantitatively understood by uncorrelated, active force fluctuations driving a nuclear medium that is dominated by an uncondensed DNA solution, for which we perform rheological measurements on an in vitro model system under similar conditions to what is expected in the nucleus. We conclude that the eukaryotic nucleus of living cells is a nonequilibrium soft material whose fluctuations are actively driven, and are far from thermal in their time dependence.

  18. Quarkonium-nucleus bound states from lattice QCD

    Beane, S.  R. [Univ. of Washington, Seattle, WA (United States); Chang, E. [Univ. of Washington, Seattle, WA (United States); Cohen, S.  D. [Univ. of Washington, Seattle, WA (United States); Detmold, W. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lin, H. -W. [Univ. of Washington, Seattle, WA (United States); Orginos, K. [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Parreño, A. [Univ., de Barcelona, Marti Franques (Spain); Savage, M.  J. [Univ. of Washington, Seattle, WA (United States)

    2015-06-11

    Quarkonium-nucleus systems are composed of two interacting hadronic states without common valence quarks, which interact primarily through multi-gluon exchanges, realizing a color van der Waals force. We present lattice QCD calculations of the interactions of strange and charm quarkonia with light nuclei. Both the strangeonium-nucleus and charmonium-nucleus systems are found to be relatively deeply bound when the masses of the three light quarks are set equal to that of the physical strange quark. Extrapolation of these results to the physical light-quark masses suggests that the binding energy of charmonium to nuclear matter is B < 40 MeV.

  19. Modifications induced by low power microwaves in plant nucleus

    Young rye plantlets exposed to low power microwaves from the X-band appeared affected at the cell nucleus level for various exposure times ranging between 30 minutes and 12 hours. Cell division capacity, controlled by cell nucleus seemed to be stimulated when the exposure was carried out on germinated caryopsides. Total number of abnormal nucleus divisions was enhanced by microwave exposure. Seed germination was slightly inhibited after electromagnetic exposure. Thermal as well as nonthermal effects at the level of nucleic acid macromolecules bearing genetic information might be invoked for the interpretation of the observed modifications

  20. Medium effects in the nucleon- nucleus reaction cross-section

    The nucleon-nucleus reaction cross-section, σR , has been calculated using Gabblers multiple scattering theory in its optical limit, A medium modified nuclear phase shift function has been obtained for nucleon-nucleus scattering using a medium two body scattering amplitude. In the present calculations, the Coulomb modified Glauber model is used. Also different forms of Gaussian density distribution, for the target nucleus, are used. A comparison of medium modified calculations with the corresponding experimental data has shown that application of the medium effect in the total reaction cross- section plays an important role for low values of energy

  1. Analysis of the thematic content of review Nucleus

    A computer programme for performing standardized analysis of research areas and key concepts of nuclear science and technology under development at Cubaenergia is presented. Main components of the information processing system, as well as computational methods and modules for thematic content analysis of INIS Database record files are described. Results of thematic content analysis of review Nucleus from 1986 to 2005 are shown. Furthermore, results of demonstrative study Nucleus, Science, Technology and Society are also shown. The results provide new elements to asses the significance of the thematic content of review Nucleus in the context of innovation in interrelated multidisciplinary research areas

  2. Electromagnetic probes of a pure-glue initial state in nucleus-nucleus collisions at LHC

    Vovchenko, V; Gorenstein, M I; Satarov, L M; Mishustin, I N; Kämpfer, B; Stoecker, H

    2016-01-01

    Partonic matter produced in the early stage of ultrarelativistic nucleus-nucleus collisions is assumed to be composed mainly of gluons, and quarks and antiquarks are produced at later times. To study the implications of such a scenario, the dynamical evolution of the chemically nonequilibrated system is described by the ideal (2+1)-dimensional hydrodynamics with a time dependent (anti)quark fugacity. The equation of state interpolates linearly between the lattice data for the pure gluonic matter and the lattice data for the chemically equilibrated quark-gluon plasma. The spectra and elliptic flows of thermal dileptons and photons are calculated for central Pb+Pb collisions at the LHC energy of $\\sqrt{s_{_{\\rm NN}}} = 2.76$ TeV. We test the sensitivity of the results to the choice of equilibration times, including also the case where the complete chemical equilibrium of partons is reached already at the initial stage. It is shown that a suppression of quarks at early times leads to a significant reduction of t...

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

    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 252Cf(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.)

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

    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 C4 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

  5. Transparency and abrasion in high-energy nucleus-nucleus collisions

    The soft spheres geometric model of nucleus-nucleus collisions has been used to incorporate a tapered nuclear density distribution into considerations of transparency and of the abrasion step of the (hard spheres) abrasion-ablation model. The useful concept of an average target transparency tr > required a careful definition to accommodate the fact the transparency becomes unity as the impact parameter approaches infinity. The result is a simple numerical and calculation that gives tr > as a function of the soft spheres parameter χ. The latter depends in a known way on the target and projectile dimensions and on the energy-dependent nucleon-nucleon cross section. In the specific case of projectile = target, the result is an analytical expression reminiscent of the Fernbach, Serber and Taylor result for hard spheres. tr > = 1 - e-χ(χ+1)/χ2. Applications are expected to be valid for any projectile-target combination at intermediate (several hundred MeV/A) through ultrarelativistic (several hundred EeV/A) energies

  6. EOS: A time projection chamber for the study of nucleus-nucleus collisions at the Bevalac

    The conceptual design is presented for a detector to identify and measure (Δp/p ≅ 1%) most of the 200 or so mid-rapidity charged particles (p, d, t, 3He, 4He, π+-, K+-) produced in each central nucleus-nucleus collision (Au + Au) at Bevalac energies, as well as K30 and Λ0. The beam particles and heavy spectator fragments are excluded from the detection volume by means of a central vacuum pipe. Particle identification is achieved by a combination of dE/dx measurements in the TPC, and of time-of-flight measurements in a scintillator array. The TPC is single-ended and its end cap is entirely covered with cathode pads (about 25,000 pads and about 1000 anode wires). A non-uniform pad distribution is proposed to accommodate the high multiplicity of particles emitted at forward angles. The performance of the detector is assessed with regard to multihit capability, tracking, momentum resolution, particle identification, Λ0 reconstruction, space charge effects, field non-uniformity, dynamic range, data acquisition rate, and data analysis rate. 72 refs., 48 figs., 11 tabs

  7. Relativistic transport approach for nucleus-nucleus collisions based on a NJL lagrangian

    Ehehalt, W; Ehehalt, Wolfgang; Cassing, Wolfgang

    1995-01-01

    We formulate a covariant transport approach for high energy nucleus-nucleus collisions where the real part of the hadron selfenergies is evaluated on the basis of a NJL-type Lagrangian for the quark degrees of freedom. The parameters of the model Lagrangian are fixed by the Gell-Mann, Oakes and Renner relation, the pion-nucleon \\Sigma-term, the nucleon energy as well as the nuclear binding energy at saturation density \\rho_0. We find the resulting scalar and vector selfenergies for nucleons to be well in line with either Dirac-Brueckner results or those from the phenomenological optical potential when accounting for a swelling of the nucleon at finite nuclear matter density. The imaginary part of the hadron selfenergies is determined by a string fragmentation model which accounts for the in-medium mass of hadrons in line with the chiral dynamics employed. The applicability of the 'chiral' transport approach is demonstrated in comparison with experimental data from SIS to SPS energies. The enhancement of the K...

  8. Charm quarks as a probe of matter produced in relativistic nucleus-nucleus collisions

    Ali Yasir

    2014-04-01

    Full Text Available Direct measurement of hadrons containing charm quark carries important information about the initial stage of the nucleus-nucleus collision at relativistic energies. The study of open charm in Pb-Pb collisions at SPS energies will be a powerful tool to investigate the production of heavy flavours and their interaction with the medium produced in such collisions. A feasibility study was initiated for the measurement of the D0 mesons (open charm by its two-body decay into pion and kaon in central Pb-Pb collision at SPS energies in NA61/SHINE experiment. To generate the physical input we used AMPT (A Multi Phase Transport Model event generator and employed GEANT4 application to describe particle transport through the NA61/SHINE experimental setup supplemented by a future vertex detector (VD that will allow for precise vertex reconstruction close to the primary interaction point. The results of the simulation shows that this measurement is feasible with a dedicated VD which allows the precise tracking close to the target.

  9. Nuclear mean field and double-folding model of the nucleus-nucleus optical potential

    Khoa, Dao T; Loan, Doan Thi; Loc, Bui Minh

    2016-01-01

    Realistic density dependent CDM3Yn versions of the M3Y interaction have been used in an extended Hartree-Fock (HF) calculation of nuclear matter (NM), with the nucleon single-particle potential determined from the total NM energy based on the Hugenholtz-van Hove theorem that gives rise naturally to a rearrangement term (RT). Using the RT of the single-nucleon potential obtained exactly at different NM densities, the density- and energy dependence of the CDM3Yn interactions was modified to account properly for both the RT and observed energy dependence of the nucleon optical potential. Based on a local density approximation, the double-folding model of the nucleus-nucleus optical potential has been extended to take into account consistently the rearrangement effect and energy dependence of the nuclear mean-field potential, using the modified CDM3Yn interactions. The extended double-folding model was applied to study the elastic $^{12}$C+$^{12}$C and $^{16}$O+$^{12}$C scattering at the refractive energies, wher...

  10. EOS: A time projection chamber for the study of nucleus-nucleus collisions at the Bevalac

    Pugh, H.G.; Odyniec, G.; Rai, G.; Seidl, P.

    1986-12-01

    The conceptual design is presented for a detector to identify and measure (..delta..p/p approx. = 1%) most of the 200 or so mid-rapidity charged particles (p, d, t, /sup 3/He, /sup 4/He, ..pi../sup + -/, K/sup + -/) produced in each central nucleus-nucleus collision (Au + Au) at Bevalac energies, as well as K/sub 3//sup 0/ and ..lambda../sup 0/. The beam particles and heavy spectator fragments are excluded from the detection volume by means of a central vacuum pipe. Particle identification is achieved by a combination of dE/dx measurements in the TPC, and of time-of-flight measurements in a scintillator array. The TPC is single-ended and its end cap is entirely covered with cathode pads (about 25,000 pads and about 1000 anode wires). A non-uniform pad distribution is proposed to accommodate the high multiplicity of particles emitted at forward angles. The performance of the detector is assessed with regard to multihit capability, tracking, momentum resolution, particle identification, ..lambda../sup 0/ reconstruction, space charge effects, field non-uniformity, dynamic range, data acquisition rate, and data analysis rate. 72 refs., 48 figs., 11 tabs.

  11. Energy-Dependence of Nucleus-Nucleus Potential and Friction Parameter in Fusion Reactions

    Wen, Kai; Li, Zhu-Xia; Wu, Xi-Zhen; Zhang, Ying-Xun; Zhou, Shan-Gui

    2014-01-01

    Applying a macroscopic reduction procedure on the improved quantum molecular dynamics (ImQMD), the energy dependences of the nucleus-nucleus potential, the friction parameter, and the random force characterizing a one-dimensional Langevin-type description of the heavy-ion fusion process are investigated. Systematic calculations with the ImQMD show that the fluctuation-dissipation relation found in the symmetric head-on fusion reactions at energies just above the Coulomb barrier fades out when the incident energy increases. It turns out that this dynamical change with increasing incident energy is caused by a specific behavior of the friction parameter which directly depends on the microscopic dynamical process, i.e., on how the collective energy of the relative motion is transferred into the intrinsic excitation energy. It is shown microscopically that the energy dissipation in the fusion process is governed by two mechanisms: One is caused by the nucleon exchanges between two fusing nuclei, and the other is ...

  12. Statistical Model of the Early Stage of nucleus-nucleus collisions with exact strangeness conservation

    Poberezhnyuk, R V; Gorenstein, M I

    2015-01-01

    The Statistical Model of the Early Stage, SMES, describes a transition between confined and deconfined phases of strongly interacting matter created in nucleus-nucleus collisions. The model was formulated in the late 1990s for central Pb+Pb collisions at the CERN SPS energies. It predicted several signals of the transition (onset of deconfinement) which were later observed by the NA49 experiment. The grand canonical ensemble was used to calculate entropy and strangeness production. This approximation is valid for reactions with mean multiplicities of particles carrying conserved charges being significantly larger than one. Recent results of NA61/SHINE on hadron production in inelastic p+p interactions suggest that the deconfinement may also take place in these reactions. However, in this case mean multiplicity of particles with non-zero strange charge is smaller than one. Thus for the modeling of p+p interactions the exact strangeness conservation has to be implemented in the SMES. This extension of the SMES ...

  13. Nucleus--nucleus interactions in the inner crust of neutron stars

    Kobyakov, D

    2016-01-01

    The interaction between nuclei in the inner crust of neutron stars consists of two contributions, the so-called "direct" interaction and an "induced" one due to density changes in the neutron fluid. For large nuclear separations $r$ the contributions from nuclear forces to each of these terms are shown to be nonzero. In the static limit they are equal in magnitude but have opposite signs and they cancel exactly. We analyze earlier results on effective interactions in the light of this finding. We consider the properties of long-wavelength collective modes and, in particular, calculate the degree of mixing between the lattice phonons and the phonons in the neutron superfluid. Using microscopic theory, we calculate the net non-Coulombic contribution to the nucleus--nucleus interaction and show that, for large $r$, the leading term is due to exchange of two phonons and varies as $1/r^7$: it is an analog of the Casimir--Polder interaction between neutral atoms.

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

    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 (TZDC) 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 TZDC is given. 34 refs., 11 figs

  15. Thermalization in high energy proton-nucleus collisions

    A relativistic proton-nucleus collision using the intranuclear cascade model is studied. The purpose is to verify the equilibration hypothesis at fragmentation time made by many nuclear fragmentation models. (author)

  16. Red nucleus connectivity as revealed by constrained spherical deconvolution tractography.

    Milardi, Demetrio; Cacciola, Alberto; Cutroneo, Giuseppina; Marino, Silvia; Irrera, Mariangela; Cacciola, Giorgio; Santoro, Giuseppe; Ciolli, Pietro; Anastasi, Giuseppe; Calabrò, Rocco Salvatore; Quartarone, Angelo

    2016-07-28

    Previous Diffusion Tensor Imaging studies have demonstrated that the human red nucleus is widely interconnected with sensory-motor and prefrontal cortices. In this study, we assessed red nucleus connectivity by using a multi-tensor model called non- negative Constrained Spherical Deconvolution (CSD), which is able to resolve more than one fiber orientation per voxel. Connections of the red nuclei of fifteen volunteers were studied at 3T using CSD axonal tracking. We found significant connectivity between RN and the following cortical and subcortical areas: cerebellar cortex, thalamus, paracentral lobule, postcentral gyrus, precentral gyrus, superior frontal gyrus and dentate nucleus. We confirmed that red nucleus is tightly linked with the cerebral cortex and has dense subcortical connections with thalamus and cerebellar cortex. These findings may be useful in a clinical context considering that RN is involved in motor control and it is known to have potential to compensate for injury of the corticospinal tract. PMID:27181514

  17. Isotope Dependence of Superheavy Nucleus Formation Cross Section

    LIU Zu-Hua; BAG Jing-Dong

    2006-01-01

    The dynamical process in the superheavy nucleus synthesis is studied on the basis of the two-dimensional Smolu-chowski equation. Special attention is paid to the isotope dependence of the cross section for the superheavy nucleus formation by means of making a comparison among the reaction systems of 54Fe + 204Pb, 56Fe + 206Pb, and 58Fe + 208Pb. It is found by this comparison that the formation cross section is very sensitive to the conditional saddle-point height and the neutron separation energy of the compound nucleus. Reaction systems with lower height of conditional saddle-point and smaller neutron separation energy are more favourable for the synthesis of the superheavy nucleus.

  18. Low-Energy Antinucleon-Nucleus Interaction Revisited

    Friedman, E

    2015-01-01

    Annihilation cross sections of antiprotons and antineutrons on the proton between 50 and 400 MeV/c show Coulomb focusing below 200 MeV/c and almost no charge-dependence above 200 MeV/c. Similar comparisons for heavier targets are not possible for lack of overlap between nuclear targets studied with $\\bar p$ and $\\bar n$ beams. Interpolating between $\\bar p$-nucleus annihilation cross sections with the help of an optical potential to compare with $\\bar n$-nucleus annihilation cross sections reveal unexpected features of Coulomb interactions in the latter. Direct comparisons between $\\bar n$-nucleus and $\\bar p$-nucleus annihilations at very low energies could be possible if $\\bar p$ cross sections are measured on the same targets and at the same energies as the available cross sections for $\\bar n$. Such measurements may be feasible in the foreseeable future.

  19. Microscopic relativistic model for deuteron-nucleus scattering

    The relativistic deuteron structure described by the Bethe-Salpeter formalism is used to obtain the deuteron-nucleus interaction from the covariant convolution of Dirac-phenomenology nucleon-nucleus potentials. Multiple scattering contributions to deuteron-nucleus scattering are taken into account by the positive energy subtracted impulse approximation which results from an analysis of the role played by the relativistic degrees of freedom. A detailed comparison of calculations with deuteron-nucleus elastic scattering data at intermediate energies, including polarization observables, is presented. It is shown that good agreement with the data is obtained when the full spin structure of the interaction that results from the relativistic model is included in the calculations. copyright 1996 The American Physical Society

  20. Nucleus management in manual small incision cataract surgery by phacosection

    Ravindra M

    2009-01-01

    Full Text Available Nucleus management is critical in manual small incision cataract surgery (MSICS, as the integrity of the tunnel, endothelium and posterior capsule needs to be respected. Several techniques of nucleus management are in vogue, depending upon the specific technique of MSICS. Nucleus can be removed in toto or bisected or trisected into smaller segments. The pressure in the eye can be maintained at the desired level with the use of an anterior chamber maintainer or kept at atmospheric levels. In MSICS, unlike phacoemulsification, there is no need to limit the size of the tunnel or restrain the size of capsulorrhexis. Large well-structured tunnels and larger capsulorrhexis provide better control on the surgical maneuvers. Safety and simplicity of MSICS has made it extremely popular. The purpose of this article is to describe nucleus management by phacosection in MSICS.

  1. Asymptotic properties of high-pT particle production in hadron-hadron, hadron-nucleus and nucleus-nucleus collisions at high energies

    Tokarev, M V

    2001-01-01

    The concept of z-scaling reflecting the general features of particle substructure, constituent interaction and mechanism of particle formation is reviewed. Experimental data on the cross sections obtained at ISR, SpS and Tevatron are used in the analysis. The properties of data z-presentation, the energy and angular independencies, the power law, A- and F-dependencies, are discussed. The use of z-scaling to search for new physics phenomena in hadron-hadron, hadron-nucleus and nucleus-nucleus collisions is suggested. The violation of z-scaling characterized by the change of the fractal dimension is considered as a new and complimentary signature of nuclear phase transition.

  2. Specific structure of the 6He nucleus and fragmentation experiments

    Within the framework of the microscopic α+2n model, transverse momentum distributions of α-particles and neutrons as well as α-particle - neutron momentum correlation function have been calculated for the radioactive 6He nucleus fragmentation. The results show that these momentum distributions reflect a specific structure of the 6He nucleus, i.e. the experiments on fragmentation provide with the information on 6He structure. (orig.)

  3. Nucleus Pearl Coating Process of Freshwater Mussel Anodonta woodiana (Unionidae)

    WASMEN MANALU; DEDY DURYADI SOLIHIN; SATA YOSHIDA SRIE RAHAYU; RIDWAN AFFANDI

    2013-01-01

    The limiting factor which is a weakness of sea water pearl production are high costs, the risk of major business failures and a long coating time. From the issue of freshwater pearls appear to have prospects of alternative substitution for sea water pearl. This present study aimed to evaluate effect of loads (the number and diameter nucleus) on freshwater pearl coating process and the number and size of the appropriate nucleus diameter, to produce the optimum coating thickness of half-round p...

  4. Limbic and cortical information processing in the nucleus accumbens

    Goto, Yukiori; Grace, Anthony A.

    2008-01-01

    The nucleus accumbens regulates goal-directed behaviors by integrating information from limbic structures and the prefrontal cortex. Here, we review recent studies in an attempt to provide an integrated view of the control of information processing in the nucleus accumbens in terms of the regulation of goal-directed behaviors and how disruption of these functions might underlie the pathological states in drug addiction and other psychiatric disorders. We propose a model that could account for...

  5. Vacuum polarization and quadrupole moment of a heavy nucleus

    The contribution of the vacuum polarization to the quadrupole moment of a heavy nucleus is considered. The leading term is obtained exactly in Zα, using the electron Green function in the Coulomb field. This term contains the large logarithm of the ratio λ/R, where R is the nucleus radius and λ is the electron Compton wavelength. The spatial distributions of the induced charge and potential are discussed also. 9 refs.; 1 fig

  6. Ion-beam spectroscopic studies of the 69As nucleus

    Excited state of the neutron deficient 69As nucleus were investigated in the 58Ni(14N,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 69As 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)

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

    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

  8. Inelaticity in hadron-nucleus collisions from emulsion chamber studies

    Wilk, G

    1999-01-01

    The inelasticity of hadron-carbon nucleus collisions in the energy region exceeding 100 TeV is estimated from the carbon-emulsion chamber data at Pamirs to be $ = 0.65\\pm 0.08$. When combined with the recently presented data on hadron-lead nucleus collisions taken at the same energy range it results in the $K\\sim A^{0.086}$ mass number dependence of inelasticity. The evaluated partial inelasticity for secondary ($\

  9. Shell Correction at the Saddle Point for Superheavy Nucleus

    张炜; 张时声; 张双全; 孟杰

    2003-01-01

    The potential energy surface for superheavy nucleus has been studied within the framework of the constrained relativistic mean field theory, and the shell correction energy as a function of deformation has been extracted by the Strutinsky shell correction procedure. Contrary to the usual expectation, the shell correction energy at the saddle point is too important to be neglected, and it has essential contribution to the fission barrier in superheavy nucleus.

  10. 3200 Phaethon, Asteroid or Comet Nucleus?

    Boice, Daniel C.; Benkhoff, Johannes

    2015-08-01

    Physico-chemical modeling is central to understand the important physical processes in small solar system bodies. We have developed a computer simulation, SUISEI, that includes the physico-chemical processes relevant to comets within a global modeling framework. Our goals are to gain valuable insights into the intrinsic properties of cometary nuclei so we can better understand observations and in situ measurements. SUISEI includes a 3-D model of gas and heat transport in porous sub-surface layers in the interior of the nucleus.We present results on the application of SUISEI to the near-Sun object, Phaethon. Discovered in 1983 and classified as an asteroid, it has recently exhibited an active dust coma. Phaethon has long been associated as the source of the Geminids meteor shower so the dust activity provides a clear link to the meteor shower. The observed dust activity would traditionally lead to Phaethon being also classified as a comet (e.g., 2060-95P/Chiron, 133P/Elst-Pizarro). This is unusual since the orbit of Phaethon has a perihelion of 0.14 AU, resulting in surface temperatures of more than 1025K, much too hot for water ice or other volatiles to exist near the surface and drive the activity. This situation and others such as the “Active Asteroids” necessitates a revision of how we understand and classify these small asteroid-comet transition objects.We conclude the following for Phaethon:1. It is likely to contain relatively pristine volatiles in its interior despite repeated near perihelion passages of 0.14 AU during its history in its present orbit,2. Steady water gas fluxes at perihelion and throughout its orbit are insufficient to entrain the currently observed dust production,3. Thermal gradients into the surface as well as those caused by diurnal rotation are consistent with the mechanism of dust release due to thermal fracture,4. The initial large gas release during the first perihelion passage may be sufficient to produce enough dust to explain

  11. A Universal Description of Pseudorapidity Distributions in Both Nucleus-Nucleus and p-p Collisions at Currently Available Energies

    Z. J. Jiang

    2016-01-01

    Full Text Available Investigations have shown that the collective motion appears not only in nucleus-nucleus but also in p-p collisions. The best tool for depicting such collective motion is relativistic hydrodynamics. In this paper, the collective motion is assumed to obey the hydrodynamic model which integrates the features of Landau and Hwa-Bjorken theory and is one of a very few analytically solvable models. The fluid is then supposed to freeze out into charged particles from a space-like hypersurface with a fixed time of tFO. The investigations of present paper show that this part of charged particles together with leading particles, which, by conventional definition, carry on the quantum numbers of colliding nucleons and take away the most part of incident energy, can give a proper universal description to the pseudorapidity distributions of charged particles measured in both nucleus-nucleus and p-p collisions at currently available energies.

  12. The picture of the nuclei disintegration mechanism - from nucleus-nucleus collision experimental data at high energies

    Experimental data on nuclear collisions at high energies, mainly obtained from photographic emulsions, are considered from the point of view of the picture of the nuclear collision processes mechanisms prompted experimentally. In fact, the disintegration products of each nucleus involved in a nuclear collision, in its own rest-frame, are similar to that produced by the impact of a number of nucleons of velocity equal to that of the moving primary nucleus

  13. Modulation of the arcuate nucleus-medial preoptic nucleus lordosis regulating circuit: a role for GABAB receptors

    Sinchak, Kevin; Dewing, Phoebe; Ponce, Laura; Gomez, Liliana; Christensen, Amy; Berger, Max; Micevych, Paul

    2013-01-01

    Estradiol rapidly activates a microcircuit in the arcuate nucleus of the hypothalamus (ARH) that is needed for maximal female sexual receptivity. Membrane estrogen receptor-α complexes with and signals through the metabotropic glutamate receptor-1a stimulating NPY release within the ARH activating proopiomelanocortin (POMC) neurons. These POMC neurons project to the medial preoptic nucleus (MPN) and release β-endorphin. Estradiol treatment induces activation/internalization of MPN μ-opioid re...

  14. ELECTROPHYSIOLOGICAL PROPERTIES OF MORPHOLOGICALLY-IDENTIFIED MEDIAL VESTIBULAR NUCLEUS NEURONS PROJECTING TO THE ABDUCENS NUCLEUS IN THE CHICK EMBRYO

    Gottesman-Davis, Adria; Shao, Mei; Hirsch, June C.; Peusner, Kenna D.

    2010-01-01

    Neurons in the medial vestibular nucleus (MVN) show a wide range of axonal projection pathways, intrinsic firing properties, and responses to head movements. To determine whether MVN neurons participating in the vestibulocular reflexes (VOR) have distinctive electrophysiological properties related to their output pathways, a new preparation was devised using transverse brain slices containing the chicken MVN and abducens nucleus. Biocytin Alexa Fluor was injected extracellularly into the abdu...

  15. On the Role of the Transition State Nucleus in Fission

    Although it is well-known that times. In order for fission to compete favourably with gamma-ray and neutron emission, a fixed amount of energy, equivalent to an activation energy in a chemical reaction, must be supplied to the heavy nucleus. This energy (often referred to as the fission threshold) is approximately 5 to 6 MeV for U238, and is the minimum energy required to produce the deformed transition state nucleus (zero internal excitation energy). In the process of stretching the original nucleus into the transition state nucleus (whose distortion is sometimes described as the saddle-point deformation), the increase in energy due to the short-range nuclear forces (surface tension) is greater than the decrease in energy due to the long-range Coulomb forces. However, as the particular distortion defining the transition state nucleus is approached, the decrease in Coulomb energy becomes equal to the increase in surface energy. The degree of distortion needed to produce the transition state nucleus is a function of several nuclear parameters and, hence, the saddle shape and threshold energy for fission change markedly for different nuclei. Since a large fraction of the excitation energy of the initial compound nucleus is consumed in deformation energy in passing to the fission saddle point, the transition state nucleus is thermodynamically ''cold''. Hence, for low excitation energies where the non-fission degrees of freedom favour the passage of the barrier with only a small kinetic energy, it seems reasonable to postulate that the traversal time of the saddle or the lifetime of the transition state nucleus is many orders of magnitude longer than the characteristic nuclear time. This leads to the prediction that the highly deformed transition state nucleus will have properties, including a spectrum of excited states, analogous to those of normal nuclei. Information on highly deformed transition state nuclei obtained by fission-fragment angular distribution studies

  16. The deafferented reticular thalamic nucleus generates spindle rhythmicity.

    Steriade, M; Domich, L; Oakson, G; Deschênes, M

    1987-01-01

    The hypothesis that nucleus reticularis thalami (RE) is the generator of spindle rhythmicity during electroencephalogram (EEG) synchronization was tested in acutely prepared cats. Unit discharges and focal waves were extracellularly recorded in the rostral pole of RE nucleus, which was completely disconnected by transections from all other thalamic nuclei. In some experiments, additional transections through corona radiata created a triangular island in which the rostral RE pole survived with the caudate nucleus, putamen, basal forebrain nuclei, prepyriform area, and the adjacent cortex. Similar results were obtained in two types of experiments: brain stem-transected preparations that exhibited spontaneous spindle sequences, and animals under ketamine anesthesia in which transient spindling was repeatedly precipitated during recording by very low doses of a short-acting barbiturate. Both spindle-related rhythms (7- to 16-Hz waves grouped in sequences that recur with a rhythm of 0.1-0.3 Hz) are seen in focal recordings of the deafferented RE nucleus. The presence of spindling rhythmicity in the disconnected RE nucleus contrasts with total absence of spindles in cortical EEG leads and in thalamic recordings behind the transection. Oscillations within the same frequency range as that of spontaneous spindles can be evoked in the deafferented RE nucleus by subcortical white matter stimulation. In deafferented RE cells, the burst structure consists of an initially biphasic acceleration-deceleration pattern, eventually leading to a long-lasting tonic tail. Quantitative group data show that the burst parameters of disconnected RE cells are very similar to those of RE neurons with intact connections. In the deafferented RE nucleus, spike bursts of RE neurons recur periodically (0.1-0.3 Hz) in close time-relation with simultaneously recorded focal spindle sequences. The burst occurrence of deafferented RE cells is greatly reduced after systemic administration of bicuculline

  17. Fluctuations and correlations in nucleus-nucleus collisions within transport approaches

    Konchakovski, Volodymyr P.

    2009-10-01

    The current thesis is devoted to a systematic study of fluctuations and correlations in heavy-ion collisions, which might be considered as probes for the phase transition and the critical point in the phase diagram, within the Hadron-String- Dynamics (HSD) microscopic transport approach. This is a powerful tool to study nucleus-nucleus collisions and allows to completely simulate experimental collisions on an event-by-event basis. Thus, the transport model has been used to study fluctuations and correlations including the influence of experimental acceptance as well as centrality, system size and collision energy. The comparison to experimental data can separate the effects induced by a phase transition since there is no phase transition in the HSD version used here. Firstly the centrality dependence of multiplicity fluctuations has been studied. Different centrality selections have been performed in the analysis in correspondence to the experimental situation. For the fixed target experiment NA49 events with fixed numbers of the projectile participants have been studied while in the collider experiment PHENIX centrality classes of events have been defined by the multiplicity in certain phase space region. A decrease of participant number fluctuations (and thus volume fluctuations) in more central collisions for both experiments has been obtained. Another area of this work addresses to transport model calculations of multiplicity fluctuations in nucleus-nucleus collisions as a function of colliding energy and system size. This study is in full correspondence to the experimental program of the NA61 Collaboration at the SPS. Central C+C, S+S, In+In, and Pb+Pb nuclear collisions at Elab = 10, 20, 30, 40, 80, 158 AGeV have been investigated. The expected enhanced fluctuations - attributed to the critical point and phase transition - can be observed experimentally on top of a monotonic and smooth 'hadronic background'. These findings should be helpful for the

  18. Fluctuations and correlations in nucleus-nucleus collisions within transport approaches

    The current thesis is devoted to a systematic study of fluctuations and correlations in heavy-ion collisions, which might be considered as probes for the phase transition and the critical point in the phase diagram, within the Hadron-String- Dynamics (HSD) microscopic transport approach. This is a powerful tool to study nucleus-nucleus collisions and allows to completely simulate experimental collisions on an event-by-event basis. Thus, the transport model has been used to study fluctuations and correlations including the influence of experimental acceptance as well as centrality, system size and collision energy. The comparison to experimental data can separate the effects induced by a phase transition since there is no phase transition in the HSD version used here. Firstly the centrality dependence of multiplicity fluctuations has been studied. Different centrality selections have been performed in the analysis in correspondence to the experimental situation. For the fixed target experiment NA49 events with fixed numbers of the projectile participants have been studied while in the collider experiment PHENIX centrality classes of events have been defined by the multiplicity in certain phase space region. A decrease of participant number fluctuations (and thus volume fluctuations) in more central collisions for both experiments has been obtained. Another area of this work addresses to transport model calculations of multiplicity fluctuations in nucleus-nucleus collisions as a function of colliding energy and system size. This study is in full correspondence to the experimental program of the NA61 Collaboration at the SPS. Central C+C, S+S, In+In, and Pb+Pb nuclear collisions at Elab = 10, 20, 30, 40, 80, 158 AGeV have been investigated. The expected enhanced fluctuations - attributed to the critical point and phase transition - can be observed experimentally on top of a monotonic and smooth 'hadronic background'. These findings should be helpful for the optimal

  19. PREFACE: 11th International Conference on Nucleus-Nucleus Collisions (NN2012)

    Li, Bao-An; Natowitz, Joseph B.

    2013-03-01

    The 11th International Conference on Nucleus-Nucleus Collisions (NN2012) was held from 27 May to 1 June 2012, in San Antonio, Texas, USA. It was jointly organized and hosted by The Cyclotron Institute at Texas A&M University, College Station and The Department of Physics and Astronomy at Texas A&M University-Commerce. Among the approximately 300 participants were a large number of graduate students and post-doctoral fellows. The Keynote Talk of the conference, 'The State of Affairs of Present and Future Nucleus-Nucleus Collision Science', was given by Dr Robert Tribble, University Distinguished Professor and Director of the TAMU Cyclotron Institute. During the conference a very well-received public lecture on neutrino astronomy, 'The ICEcube project', was given by Dr Francis Halzen, Hilldale and Gregory Breit Distinguished Professor at the University of Wisconsin, Madison. The Scientific program continued in the general spirit and intention of this conference series. As is typical of this conference a broad range of topics including fundamental areas of nuclear dynamics, structure, and applications were addressed in 42 plenary session talks, 150 parallel session talks, and 21 posters. The high quality of the work presented emphasized the vitality and relevance of the subject matter of this conference. Following the tradition, the NN2012 International Advisory Committee selected the host and site of the next conference in this series. The 12th International Conference on Nucleus-Nucleus Collisions (NN2015) will be held 21-26 June 2015 in Catania, Italy. It will be hosted by The INFN, Laboratori Nazionali del Sud, INFN, Catania and the Dipartimento di Fisica e Astronomia of the University of Catania. The NN2012 Proceedings contains the conference program and 165 articles organized into the following 10 sections 1. Heavy and Superheavy Elements 2. QCD and Hadron Physics 3. Relativistic Heavy-Ion Collisions 4. Nuclear Structure 5. Nuclear Energy and Applications of

  20. Nucleus Pearl Coating Process of Freshwater Mussel Anodonta woodiana (Unionidae

    WASMEN MANALU

    2013-03-01

    Full Text Available The limiting factor which is a weakness of sea water pearl production are high costs, the risk of major business failures and a long coating time. From the issue of freshwater pearls appear to have prospects of alternative substitution for sea water pearl. This present study aimed to evaluate effect of loads (the number and diameter nucleus on freshwater pearl coating process and the number and size of the appropriate nucleus diameter, to produce the optimum coating thickness of half-round pearls. The research consists of experimental implantation of 2, 4, and 6 nucleus number per individual mussel was maintained by the method stocked in hapa in bottom waters. Observation method and factorial randomized block design used in the study of the influence of the load to the successfulness of pearl coating and the pearl layer thickness. The results showed that A. woodiana can be utilized as a producer of freshwater pearls. In addition, the number of optimum nucleus that can be attached to the mussel A. woodiana was 2 grains/individuals with a diameter of 10 mm. Shells implanted with the optimum nucleus diameter and number of pearls produced the highest layer thickness of 17 m after 9 months cultivation. This result was good enough compared with the layer thickness of sea water pearl production after the same cultivation time.

  1. The hadron-nucleus collision reaction mechanism memorized by fast nucleons emitted from target nuclei

    It is shown in this work that: 1. The target-nucleus damaged in a hadron-nucleus nuclear collision memorizes information about the collision mechanism; 2. Similar information is contained in characteristics of the incident hadron passage through the target nucleus. The mechanism of the hadron-nucleus collision process is presented - as experimentally based, from the collision reaction starting up to the destroyed target-nucleus transmutation into stable fragments. 34 refs., 2 figs

  2. Optimal reactions for the synthesis of superheavy nucleus 270Hs

    LIU Zuhua; BAO Jingdong

    2006-01-01

    The superheavy nucleus 270 Hs iS expected to be a "double-magic" deformed nucleus.We have calculated its cross sections of evaporation residue for the reactions 248Cm(26Mg,4n)270Hs,244pu(30Si,4n)270Hs,238U(36S,4n)270Hs and 226Ra(48Ca,4n)270Hs using a two-parameter Smoluchowski equation.It is found from our results that 226Ra(48Ca,4n)270Hs and 238U(36S,4n)270Hs are two optimal reactions for the synthesis of the superheavy nucleus 270Hs due to their large negative Q-values.

  3. Extreme alpha-clustering in the 18O nucleus

    Johnson, E D; Goldberg, V Z; Brown, S; Robson, D; Crisp, A M; Cottle, P D; Fu, C; Giles, J; Green, B W; Kemper, K W; Lee, K; Roeder, B T; Tribble, R E

    2009-01-01

    The structure of the 18O nucleus at excitation energies above the alpha decay threshold was studied using 14C+alpha resonance elastic scattering. A number of states with large alpha reduced widths have been observed, indicating that the alpha-cluster degree of freedom plays an important role in this N not equal Z nucleus. However, the alpha-cluster structure of this nucleus is very different from the relatively simple pattern of strong alpha-cluster quasi-rotational bands in the neighboring 16O and 20Ne nuclei. A 0+ state with an alpha reduced width exceeding the single particle limit was identified at an excitation energy of 9.9+/-0.3 MeV. We discuss evidence that states of this kind are common in light nuclei and give possible explanations of this feature.

  4. A Direct Neurokinin B Projection from the Arcuate Nucleus Regulates Magnocellular Vasopressin Cells of the Supraoptic Nucleus.

    Pineda, R; Sabatier, N; Ludwig, M; Millar, R P; Leng, G

    2016-04-01

    Central administration of neurokinin B (NKB) agonists stimulates immediate early gene expression in the hypothalamus and increases the secretion of vasopressin from the posterior pituitary through a mechanism that depends on the activation of neurokinin receptor 3 receptors (NK3R). The present study reports that, in the rat, immunoreactivity for NK3R is expressed in magnocellular vasopressin and oxytocin neurones in the supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus, and that NKB immunoreactivity is expressed in fibres in close juxtaposition with vasopressin neurones at both of these sites. Retrograde tracing in the rat shows that some NKB-expressing neurones in the arcuate nucleus project to the SON and, in mice, using an anterograde tracing approach, it is found that kisspeptin-expressing neurones of the arcuate nucleus, which are known to co-express NKB, project to the SON and PVN. Finally, i.c.v. injection of the NK3R agonist senktide is shown to potently increase the electrical activity of vasopressin neurones in the SON in vivo with no significant effect detected on oxytocin neurones. The results suggest that NKB-containing neurones in the arcuate nucleus regulate the secretion of vasopressin from magnocellular neurones in rodents, and the possible significance of this is discussed. PMID:26610724

  5. Immobility, inheritance and plasticity of shape of the yeast nucleus

    Andrulis Erik D

    2007-11-01

    Full Text Available Abstract Background Since S. cerevisiae undergoes closed mitosis, the nuclear envelope of the daughter nucleus is continuous with that of the maternal nucleus at anaphase. Nevertheless, several constitutents of the maternal nucleus are not present in the daughter nucleus. The present study aims to identify proteins which impact the shape of the yeast nucleus and to learn whether modifications of shape are passed on to the next mitotic generation. The Esc1p protein of S. cerevisiae localizes to the periphery of the nucleoplasm, can anchor chromatin, and has been implicated in targeted silencing both at telomeres and at HMR. Results Upon increased Esc1p expression, cell division continues and dramatic elaborations of the nuclear envelope extend into the cytoplasm. These "escapades" include nuclear pores and associate with the nucleolus, but exclude chromatin. Escapades are not inherited by daughter nuclei. This exclusion reflects their relative immobility, which we document in studies of prezygotes. Moreover, excess Esc1p affects the levels of multiple transcripts, not all of which originate at telomere-proximal loci. Unlike Esc1p and the colocalizing protein, Mlp1p, overexpression of selected proteins of the inner nuclear membrane is toxic. Conclusion Esc1p is the first non-membrane protein of the nuclear periphery which – like proteins of the nuclear lamina of higher eukaryotes – can modify the shape of the yeast nucleus. The elaborations of the nuclear envelope ("escapades" which appear upon induction of excess Esc1p are not inherited during mitotic growth. The lack of inheritance of such components could help sustain cell growth when parental nuclei have acquired potentially deleterious characteristics.

  6. Silk fibroin porous scaffolds for nucleus pulposus tissue engineering

    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.

  7. Heavy quarks in proton-nucleus collisions - the hybrid formalism

    Altinoluk, Tolga; Beuf, Guillaume; Kovner, Alex; Lublinsky, Michael

    2015-01-01

    We explore the quark mass effects on inclusive hadron production in proton-nucleus collisions at high energies. We consider two processes. First, we compute the single inclusive cross-section for production of hadrons with open heavy flavour in the proton forward direction at leading order. Next, in the same kinematics, we calculate the heavy-quark contribution to single inclusive production of light or unidentified hadrons at next-to-leading-order. For both studies we exploit the hybrid formalism, that is the collinear factorisation on the proton side while high-density and high-energy effects are resummed on the side of the nucleus.

  8. Formation and decay of a hot compound nucleus

    The compound nucleus plays an important role in nuclear reactions over a wide range of projectile-target combinations and energies. The limits that angular momentum places on its formation and existence are, for the most part, well understood. The limits on its excitation energy are not as clear. Here we first analyze general geometrical and thermodynamical features of a hot compound nucleus. We then discuss the manners by which it can decay and close by speculating on the high energy limit to its formation and existence. (author)

  9. Recent Developments in Neutrino/Antineutrino-Nucleus Interactions

    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. An occultation of the inner Seyfert nucleus of NGC 4151

    The brightness of the unresolved nucleus of NGC 4151 was monitored over five months in 1983. Variations of ≅ 0.1 mag/day were observed in the U-band and no significant variation was found of the -OIII] 5007 A emission line. However, an event that was observed on the nights of the 10/11 and 11/12 February 1983 in the continuum around 5672 A has all the characteristics of an occultation. It is proposed that an inner synchrotron nucleus of ≅ 3 a.u. diameter was occulted by an opaque cloud ≅ 6 a.u. across on those two nights

  11. Weak interaction and nucleus: the relationship keeps on

    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. Final State Interactions Effects in Neutrino-Nucleus Interactions

    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.

  13. Hyper deformation and clustering configuration in 168Yb nucleus

    Recently an exhaustive experimental search for hyper deformation in 168Yb with β ∼ 1.0 and axis ratio 3:1 at spins 70-80ℎ has yielded negative result which is attributed either to the fact that the fission of the compound nucleus prevented population of hyper deformed states or that the amount of angular momentum brought into the compound system was not sufficient to allow population of hyper deformed states. A systematic theoretical search for detection of such hyper deformation in this nucleus using the cranked Nilsson Strutinsky method with tuning to fixed spins was undertaken

  14. Examination of the fission time of the Z =120 nucleus

    Sikdar, A. K.; Ray, A.; Chatterjee, A.

    2016-04-01

    We show that the large difference in the measured lifetime for asymmetric fission of the highly excited (T ≈1.5 -MeV ) Z =120 nucleus as measured by the atomic techniques (crystal blocking and x-ray methods) with those measured by the nuclear techniques (mass-angle distribution and prefission neutron multiplicity) cannot be due to the different sensitivities of the atomic and nuclear techniques in different time domains. The claim of formation of a superheavy Z =120 nucleus with a high fission barrier on the basis of an observed long fission time by the atomic techniques is in direct conflict with all other available measurements and calculations.

  15. Electromagnetic properties of the Beryllium-11 nucleus in Halo EFT

    Hammer H.-W.; Phillips D.R.

    2010-01-01

    We compute electromagnetic properties of the Beryllium-11 nucleus using an effective field theory that exploits the separation of scales in this halo system. We fix the parameters of the EFT from measured data on levels and scattering lengths in the 10Be plus neutron system. We then obtain predictions for the B(E1) strength of the 1/2+ to 1/2− transition in the 11Be nucleus. We also compute the charge radius of the ground state of 11Be. Agreement with experiment within the expected accurac...

  16. Sensitivity of reaction cross sections to halo nucleus density distributions

    Alkhazov, G. D.; Sarantsev, V. V.

    2013-01-01

    In order to clear up the sensitivity of the nucleus--nucleus reaction cross sections $\\sigma_R$ to the nuclear matter distributions in exotic halo nuclei, we have calculated the values of $\\sigma_R$ for scattering of $^6$He, $^{11}$Li, and $^{19}$C nuclei on several nuclear targets at the energy of 0.8 GeV/nucleon. The calculations were performed in the "rigid target" approximation to the Glauber theory, different shapes of the nuclear density distributions in $^6$He, $^{11}$Li, and $^{19}$C ...

  17. Internal-nuclear conversion of energy of nucleus excited state

    In the work an effect of penetration electrons of internal conversion showing in hindered M1-transitions was studied. At the moment of a nucleus transition from excited state in low state, electron of atomic shell can appear inside a nucleus and the internal conversion of electrons occur. For such transitions nuclear parameter do not equal zero. The analytical method of definition of nuclear parameter is offered from the relation of intensities L1/L2, L1/L3, L2/L3 of internal conversion of electrons. (authors)

  18. Formation and decay of a hot compound nucleus

    Carlson, B.V.; Dalmolin, F.T.; Dutra, M.; Santos, T.J., E-mail: brett@ita.br [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos SP (Brazil); Souza, S.R. [Universidade Federal de Rio Grande do Sul (UFRS), Porto Alegre RS, (Brazil); Universidade Federal de Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Fisica; Donangelo, R. [Instituto de Fisica, Universidad de la Republica de Uruguay, Montevideo (Uruguay); Universidade Federal de Rio Grande do Sul (UFRS), Porto Alegre RS, (Brazil)

    2014-07-01

    The compound nucleus plays an important role in nuclear reactions over a wide range of projectile-target combinations and energies. The limits that angular momentum places on its formation and existence are, for the most part, well understood. The limits on its excitation energy are not as clear. Here we first analyze general geometrical and thermodynamical features of a hot compound nucleus. We then discuss the manners by which it can decay and close by speculating on the high energy limit to its formation and existence. (author)

  19. Spectra Statistics for the Odd-Odd Nucleus 86Nb

    ZHENG Ren-Rong; ZHU Shun-Quan; CHENG Nan-Pu

    2001-01-01

    The energy levels of the odd-odd nucleus 86 Nb at low spins are calculated by using quasi-particles plus a rotor model. The distribution of the nearest-neighbour spacing and the spectral rigidity are studied. We find that the chaotic degree of the energy spectra increases with the increasing spin and reaches a maximum at I = 10; then it decreases gradually for spins above I = 10. The recoil term in the model Haniltonian makes the energy spectra slightly regular. The Coriolis force, however, makes the spectra chaotic and plays a major role in the spectral statistics of the odd-odd nucleus 86Nb.

  20. Analysis of Intermediate-Energy Nucleus-Nucleus Spallation, Fission, and Fragmentation Reactions with the LAQGSM code

    Mashnik, S G; Prael, R E; Sierk, A J

    2003-01-01

    The LAQGSM code has been recently developed at Los Alamos National Laboratory to simulate nuclear reactions for proton radiography applications. We have benchmarked our code against most available measured data both for proton-nucleus and nucleus-nucleus interactions at incident energies from 10 MeV to 800 GeV and have compared our results with predictions of other current models used by the nuclear community. Here, we present a brief description of our code and show illustrative results obtained with LAQGSM for neutron spectra measured recently by Nakamura's groups for reactions induced by light and medium nuclei on targets from C to Pb at several incident energies from 95 to 600 MeV/nucleon and with the recent GSI measurements of spallation, fission, and fragmentation yields from A+p and A+A reactions at incident energies near and below 1 GeV/nucleon. Further necessary work is outlined.

  1. A comparative analysis of mechanisms of fast light particles production in nucleus-nucleus collisions at low and intermediate energies

    Denikin, A S

    2002-01-01

    The dynamics and the mechanisms of formation of pre-equilibrium light particles in nucleus-nucleus collisions at low and intermediate energies are discussed in terms of a classical four-body model. The energy and angular distributions of light particles have been calculated. It has been found that at energies lower than 50A MeV the formation of the most high-energy part of the nuclear spectrum occurs at the expense of the acceleration of light target particles with the mean field of the projectile. The obtained data are in good agreement with available experimental data

  2. Universal Services: Nucleus for a Social European Private Law

    MICKLITZ, Hans-Wolfgang

    2009-01-01

    The paper is intended to develop the idea that the growing number of rules on universal services allows for the introduction of a debate about whether these rules contain the nucleus of a new social European private law. This all the more important as the European Community will change the social character of consumer law by means of full harmonization.

  3. Theory status of quarkonium production in proton-nucleus collisions

    Lansberg, J P

    2015-01-01

    I give a brief overview of the recent theoretical progress in the study of quarkonium production in proton-nucleus collisions in view of the recent LHC and RHIC results. A special emphasis is put on the excited states such as the psi', Upsilon(2S) and Upsilon(3S).

  4. Three-dimensional organization of the human interphase nucleus

    T.A. Knoch (Tobias); C. Münkel (Christian); W. Waldeck (Waldemar); J. Langowski (Jörg)

    2000-01-01

    textabstractDespite the successful linear sequencing of the human genome its three-dimensional structure is widely unknown, although it is important for gene regulation and replication. For a long time the interphase nucleus has been viewed as a 'spaghetti soup' of DNA without much internal structur

  5. CTP synthase forms cytoophidia in the cytoplasm and nucleus

    CTP synthase is an essential metabolic enzyme responsible for the de novo synthesis of CTP. Multiple studies have recently showed that CTP synthase protein molecules form filamentous structures termed cytoophidia or CTP synthase filaments in the cytoplasm of eukaryotic cells, as well as in bacteria. Here we report that CTP synthase can form cytoophidia not only in the cytoplasm, but also in the nucleus of eukaryotic cells. Both glutamine deprivation and glutamine analog treatment promote formation of cytoplasmic cytoophidia (C-cytoophidia) and nuclear cytoophidia (N-cytoophidia). N-cytoophidia are generally shorter and thinner than their cytoplasmic counterparts. In mammalian cells, both CTP synthase 1 and CTP synthase 2 can form cytoophidia. Using live imaging, we have observed that both C-cytoophidia and N-cytoophidia undergo multiple rounds of fusion upon glutamine analog treatment. Our study reveals the coexistence of cytoophidia in the cytoplasm and nucleus, therefore providing a good opportunity to investigate the intracellular compartmentation of CTP synthase. - Highlights: • CTP synthase forms cytoophidia not only in the cytoplasm but also in the nucleus. • Glutamine deprivation and Glutamine analogs promotes cytoophidium formation. • N-cytoophidia exhibit distinct morphology when compared to C-cytoophidia. • Both CTP synthase 1 and CTP synthase 2 form cytoophidia in mammalian cells. • Fusions of cytoophidia occur in the cytoplasm and nucleus

  6. Inclusive jet production in ultrarelativistic proton-nucleus collisions

    Perepelitsa, Dennis

    High-$p_\\mathrm{T}$ processes in proton- and deuteron-nucleus collisions at TeV energies are the best presently available way to study the partonic structure of the nucleus in a high-density regime. Jet production over a wide range of phase space can significantly constrain the current knowledge of nuclear parton distribution functions (nPDFs), which are substantially less well understood than the corresponding PDFs in protons and which have only recently begun to be treated in a spatially-dependent way. An accurate knowledge of nPDFs is crucial for a definitive control of perturbative processes in a cold nuclear environment, since high-$p_\\mathrm{T}$ probes are used to quantitatively investigate the hot QCD matter created in ultrarelativistic nucleus-nucleus collisions. Furthermore, jets from low Bjorken-$x$ partons can probe the transition from the dilute to saturated nuclear regimes. Jet production is investigated in $d$+Au collisions at $\\sqrt{s} = 200$ GeV with the PHENIX detector at the Relativistic Hea...

  7. Nucleus accumbens dopamine receptors in the consolidation of spatial memory.

    Mele, A.; Avena, M.; Roullet, P.; Leonibus, E. de; Mandillo, S.; Sargolini, F.; Coccurello, R.; Oliverio, A.

    2004-01-01

    Nucleus accumbens dopamine is known to play an important role in motor activity and in behaviours governed by drugs and natural reinforcers, as well as in non-associative forms of learning. At the same time, activation of D1 and D2 dopamine receptors has been suggested to promote intracellular event

  8. CTP synthase forms cytoophidia in the cytoplasm and nucleus

    Gou, Ke-Mian [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT (United Kingdom); State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193 (China); Chang, Chia-Chun [Institute of Biotechnology, National Taiwan University, Taipei, Taiwan, ROC (China); Shen, Qing-Ji [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT (United Kingdom); Sung, Li-Ying, E-mail: liyingsung@ntu.edu.tw [Institute of Biotechnology, National Taiwan University, Taipei, Taiwan, ROC (China); Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan, ROC (China); Liu, Ji-Long, E-mail: jilong.liu@dpag.ox.ac.uk [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT (United Kingdom)

    2014-04-15

    CTP synthase is an essential metabolic enzyme responsible for the de novo synthesis of CTP. Multiple studies have recently showed that CTP synthase protein molecules form filamentous structures termed cytoophidia or CTP synthase filaments in the cytoplasm of eukaryotic cells, as well as in bacteria. Here we report that CTP synthase can form cytoophidia not only in the cytoplasm, but also in the nucleus of eukaryotic cells. Both glutamine deprivation and glutamine analog treatment promote formation of cytoplasmic cytoophidia (C-cytoophidia) and nuclear cytoophidia (N-cytoophidia). N-cytoophidia are generally shorter and thinner than their cytoplasmic counterparts. In mammalian cells, both CTP synthase 1 and CTP synthase 2 can form cytoophidia. Using live imaging, we have observed that both C-cytoophidia and N-cytoophidia undergo multiple rounds of fusion upon glutamine analog treatment. Our study reveals the coexistence of cytoophidia in the cytoplasm and nucleus, therefore providing a good opportunity to investigate the intracellular compartmentation of CTP synthase. - Highlights: • CTP synthase forms cytoophidia not only in the cytoplasm but also in the nucleus. • Glutamine deprivation and Glutamine analogs promotes cytoophidium formation. • N-cytoophidia exhibit distinct morphology when compared to C-cytoophidia. • Both CTP synthase 1 and CTP synthase 2 form cytoophidia in mammalian cells. • Fusions of cytoophidia occur in the cytoplasm and nucleus.

  9. Parity non-conserving effects in neutron-nucleus scattering

    The present lecture reviews the motivations which led to study the contribution of the neutron-nucleus component to parity-non-conserving effects observed in medium-heavy nuclei and considers its present status. It is shown that it cannot account for those experimental data. The order interpretation of these effects, which cannot lead to precise statements, is schematically described

  10. Exotic atoms, K-nucleus scattering and hypernuclei

    Recent progress in exotic atom physics, kaon-nucleus scattering, and hypernuclear physics is reviewed. Specific problems discussed include searches for muon-nucleon interactions beyond QED, a comparison of data and recent calculation of K+- + 12C elastic and inelastic scattering, as well as recent studies of Σ and Λ hypernuclei including new data on the level structure of 13C/Λ

  11. Electron elastic scattering and quark structure of 3He nucleus

    It is shown that for the interpretation of the behaviour of the 3He nucleus form factor at transfer momenta q > 6 fmsup(-1) of importance are nine-quark admixtures and their interference with nucleon and six-quark channels

  12. Rapid feedback processing in human nucleus accumbens and motor thalamus

    Schüller, T.; Gründler, T.O.J.; Jocham, G.; Klein, T.A.; Timmermann, L.; Visser-Vandewalle, V.E.R.M.; Kuhn, J.

    2015-01-01

    The nucleus accumbens (NAcc) and thalamus are integral parts in models of feedback processing. Deep brain stimulation (DBS) has been successfully employed to alleviate symptoms of psychiatric conditions including obsessive-compulsive disorder (OCD) and Tourette's syndrome (TS). Common target structu

  13. Yrast structure of the shell model nucleus 89Nb

    In the present work, report on the study of high-spin states in the N = 48 isotone 89Nb, produced through heavy-ion fusion evaporation reaction has been made. The previously known level scheme in this nucleus has been extended to ∼ 10.5 MeV excitation energy and up to spin around 23ħ

  14. First observation of the doubly magic nucleus 78Ni50

    The doubly magic nucleus of 78Ni has been identified for the first time and the associated production yield was measured in the projectile-fission reaction of 238U on Pb and Be targets at relativistic energies. (K.A.)

  15. The deuteron-nucleus interaction at intermediate energies

    The relativistic deuteron structure is used to obtain the deuteron nucleus interaction in a relativistic impulse calculation. We conclude that the PESIA multiple-scattering approximation, used in conjunction with a fully-relativistic deuteron wave function, seems to describe reasonably well the scattering data, while other more conventional multiple scattering approximations fail to do so. copyright 1995 American Institute of Physics

  16. Three-dimensional organization of the human interphase nucleus

    T.A. Knoch (Tobias); M. Wachsmuth (Malte); W. Waldeck (Waldemar); J. Langowski (Jörg)

    2002-01-01

    markdownabstractTo approach the three-dimensional organization of the human cell nucleus, the structural-, scaling- and dynamic properties of interphase chromosomes and cell nuclei were simulated with Monte Carlo and Brownian Dynamics methods. The 30 nm chromatin fibre was folded according to the Mu

  17. Three-dimensional organization of the human interphase nucleus.

    T.A. Knoch (Tobias); M. Wachsmuth (Malte); W. Waldeck (Waldemar); J. Langowski (Jörg)

    2002-01-01

    textabstractTo approach the three-dimensional organization of the human cell nucleus, the structural-, scaling- and dynamic properties of interphase chromosomes and cell nuclei were simulated with Monte Carlo and Brownian Dynamics methods. The 30 nm chromatin fibre was folded according to the Multi-

  18. Three-dimensional organization of the human interphase nucleus

    T.A. Knoch (Tobias); M. Wachsmuth (Malte); W. Waldeck (Waldemar); J. Langowski (Jörg)

    2002-01-01

    textabstractTo approach the three-dimensional organization of the human cell nucleus, the structural-, scaling- and dynamic properties of interphase chromosomes and cell nuclei were simulated with Monte Carlo and Brownian Dynamics methods. The 30 nm chromatin fibre was folded according to the Mul

  19. Deexcitation of superdeformed bands in the nucleus Tb-151

    Finck, C; Appelbe, D; Beck, FA; Byrski, T; Cullen, D; Curien, D; deFrance, G; Duchene, G; Erturk, S; Haas, B; Khadiri, N; Kharraja, B; Prevost, D; Rigollet, C; Stezowski, O; Twin, P; Vivien, JP; Zuber, K

    1997-01-01

    The aim of this work is to get more informations about the decay-out of superdeformed bands. One of the best candidates in the mass A similar or equal to 150 region for that kind of research is the nucleus Tb-151. From previous works, it has been established that the first excited band goes lower in

  20. Empirical Example of Nucleus with Transitional Dynamical Symmetry X(5)

    张大立; 赵惠英

    2002-01-01

    By analysing the energy spectrum, E2 transition rates and branching ratios, it is shown explicitly that the nucleus 150Nd provides an empirical example with X(5) symmetry at the critical point of the transition from U(5) to SU(3) symmetry.

  1. Neutral pion production in nucleus-nucleus collisions at 158 and 200 GeV/nucleon

    Two years ago, at the 12th Winter Workshop on Nuclear Dynamics held here in Snowbird, the authors presented WA80 limits on direct photon production in 200-GeV 32S + Au collisions. It was found that the results were consistent (within 1σ) with the absence of an excess of photons over those that can be accounted for by the two-photon decay branches of π0 and η mesons and by the small photon contributions from other radiative decays. They are in the process of finalizing the direct-photon production results from collisions of lead nuclei at 158 GeV/nucleon. The author briefly discusses the status of the analysis and gives some preliminary results at the end of this talk. However, most of this presentation is concerned with a very different aspect of the photon measurements: distributions of neutral pions. In contrast to direct photons which probe initial collision conditions, hadrons, such as neutral pions, interact strongly and decouple late in the reaction evolution and, thus, provide information concerning the system at freeze out. Transverse momentum spectra at low and intermediate pT relate to thermodynamic and hydrodynamic descriptions of the hot, dense systems. In addition, the high-pT region reflects the hard-scattering regime and may help one understand initial-state particle production by forming a bridge to proton-proton and proton-nucleus results. It follows that it is essential that the π0 measurements cover a large pT range

  2. Structures and functions in the crowded nucleus: new biophysical insights

    RonaldHancock

    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

  3. Global optical potential for nucleus-nucleus systems from 50 MeV/u to 400 MeV/u

    Furumoto, T; Takashina, M; Yamamoto, Y; Sakuragi, Y; 10.1103/PhysRevC.85.044607

    2012-01-01

    We present a new global optical potential (GOP) for nucleus-nucleus systems, including neutron-rich and proton-rich isotopes, in the energy range of $50 \\sim 400$ MeV/u. The GOP is derived from the microscopic folding model with the complex $G$-matrix interaction CEG07 and the global density presented by S{\\~ a}o Paulo group. The folding model well accounts for realistic complex optical potentials of nucleus-nucleus systems and reproduces the existing elastic scattering data for stable heavy-ion projectiles at incident energies above 50 MeV/u. We then calculate the folding-model potentials (FMPs) for projectiles of even-even isotopes, $^{8-22}$C, $^{12-24}$O, $^{16-38}$Ne, $^{20-40}$Mg, $^{22-48}$Si, $^{26-52}$S, $^{30-62}$Ar, and $^{34-70}$Ca, scattered by stable target nuclei of $^{12}$C, $^{16}$O, $^{28}$Si, $^{40}$Ca $^{58}$Ni, $^{90}$Zr, $^{120}$Sn, and $^{208}$Pb at the incident energy of 50, 60, 70, 80, 100, 120, 140, 160, 180, 200, 250, 300, 350, and 400 MeV/u. The calculated FMP is represented, with ...

  4. Antiproton Production in 11.5 A GeV/c Au+Pb Nucleus-Nucleus Collisions

    E687 Collaboration; al, T. A. Armstrong et

    1997-01-01

    We present the first results from the E864 collaboration on the production of antiprotons in 10% central 11.5 A GeV/c Au+Pb nucleus collisions at the Brookhaven AGS. We report invariant multiplicities for antiproton production in the kinematic region 1.4

  5. ARGININE VASOPRESSIN GENE EXPRESSION IN SUPRAOPTIC NUCLEUS AND PARAVENTRICULAR NUCLEUS OF HYPOTHALAMOUS FOLLOWING CEREBRAL ISCHEMIA AND REPERFUSION

    2000-01-01

    Background. Our previous studies indicated that the increased arginine vasopressin(AVP) in ischemic brain regions of gerbils could exacerbate the ischemic brain edema. This experiments is further clarify the relation between AVP and cerebral ischemia at the molecular level. Methods. The contents of AVP, AVP mRNA, AVP immunoreactive(ir) neurons in supraoptic nucleus(SON)and paraventricular nucleus(PVN) after cerebral ischemia and reperfusion were respectively determined by radioim-munoassay(RIA), immunocytochemistry( Ⅱ C), situ hybridization and computed image pattem analysis. Results. The contents of AVP in SON, PVN were increased, and the AVP ir positive neurons in SON and PVN were also significantly increased as compared with the controls after ischemia and reperfusion. And there were very light staining of AVP ir positive neurons in the other brain areas such as suprachiasmatic nucleus (SC) and periven-tricular hypothalamic nucleus (PE), but these have no significant changes as compared with the controls. During dif-ferent periods of cerebral ischemia (30~ 120 min) and reperfusion (30 min), AVP mRNA expression in SON and PVN were more markedly increased than the controls. Condusions. The transcription of AVP gene elevated, then promoting synthesis and release of AVP in SON,PVN. Under the specific condition of cerebral ischemia and repeffusion, the activity and contents of central AVP in-creased abnormally is one of the important factors which causes ischemia brain damage.

  6. Subthalamic nucleus involvement in executive functions with increased cognitive load: a subthalamic nucleus and anterior cingulate cortex depth recording study

    Rusnáková-Aulická, Š.; Jurák, Pavel; Chládek, Jan; Daniel, P.; Halámek, Josef; Baláž, M.; Bočková, M.; Chrastina, J.; Rektor, I.

    2014-01-01

    Roč. 121, č. 10 (2014), s. 1287-1296. ISSN 0300-9564 R&D Projects: GA ČR GAP103/11/0933 Institutional support: RVO:68081731 Keywords : ERD/S * Anterior cingulate cortex * Subthalamic nucleus * Flanker test * Executive functions Subject RIV: BD - Theory of Information Impact factor: 2.402, year: 2014

  7. Projections from the raphe nuclei to the suprachiasmatic nucleus of the rat

    Hay-Schmidt, Anders; Vrang, N.; Larsen, P.J.;

    2003-01-01

    Hypothalamus, Circadian rhythm, Serotonin, Nucleus, Neuronal connections, Phaseolus vulgaris-leucoagglutinin (PHA-L), Cholera toxin (ChB)......Hypothalamus, Circadian rhythm, Serotonin, Nucleus, Neuronal connections, Phaseolus vulgaris-leucoagglutinin (PHA-L), Cholera toxin (ChB)...

  8. Pedunculopontine Nucleus Gamma Band Activity-Preconscious Awareness, Waking, and REM Sleep

    Urbano, Francisco J.; Stasia M D'Onofrio; Brennon R Luster; Paige B Beck; James Robert Hyde; Veronica eBisagno; Edgar eGarcia-Rill

    2014-01-01

    The pedunculopontine nucleus (PPN) is a major component of the reticular activating system (RAS) that regulates waking and REM sleep, states of high frequency EEG activity. Recently, we described the presence of high threshold, voltage-dependent N- and P/Q-type calcium channels in RAS nuclei that subserve gamma band oscillations in the mesopontine pedunculopontine nucleus (PPN), intralaminar parafascicular nucleus (Pf), and pontine Subcoeruleus nucleus dorsalis (SubCD). Cortical gamma band ...

  9. Capsulotomy and hydroprocedures for nucleus prolapse in manual small incision cataract surgery

    Venkatesh Rengaraj; Veena Kannusamy; Ravindran Ravilla

    2009-01-01

    Manual small incision cataract surgery (MSICS) involves the manual removal of nucleus through a scleral tunnel. To achieve 100% success every time, one has to do a good capsulotomy and should master the technique to prolapse the nucleus into anterior chamber. During conversion from extracapsular cataract surgery to MSICS, one can perform a can-opener capsulotomy and prolapse the nucleus. However, it is safer and better to perform a capsulorrhexis and hydroprolapse the nucleus, as it ma...

  10. Effects of pedunculopontine nucleus area stimulation on gait disorders in Parkinson's disease.

    Ferraye, Murielle; Debû, Bettina; Fraix, Valérie; Goetz, Laurent; Ardouin, Claire; Yelnik, Jérôme; Henry-Lagrange, Christelle; Seigneuret, Eric; Piallat, Brigitte; Krack, Paul; Le Bas, Jean-François; Benabid, Alim-Louis; Chabardès, Stephan; Pollak, Pierre

    2010-01-01

    Gait disturbances are frequent and disabling in advanced Parkinson's disease. These symptoms respond poorly to usual medical and surgical treatments but were reported to be improved by stimulation of the pedunculopontine nucleus. We studied the effects of stimulating the pedunculopontine nucleus area in six patients with severe freezing of gait, unresponsive to levodopa and subthalamic nucleus stimulation. Electrodes were implanted bilaterally in the pedunculopontine nucleus area. Electrode p...

  11. The Nucleus of Translating as One Critical Concern in Translation Pedagogy and Assessment.

    Hu, Helen Chau

    1999-01-01

    Studies the translation of nonliterary texts. The objective is to associate the nucleus of translating with the value of a source-language text, advancing the claim that appropriately translating the nucleus is among the most important concerns, and to propose an approach to assessment for translation quality based on how the nucleus is rendered.…

  12. File list: ALL.Neu.20.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available ALL.Neu.20.AllAg.Nucleus_Accumbens mm9 All antigens Neural Nucleus Accumbens SRX791...SRX209196,SRX472711,SRX445333,SRX445335,SRX445331 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.20.AllAg.Nucleus_Accumbens.bed ...

  13. File list: NoD.Neu.50.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available NoD.Neu.50.AllAg.Nucleus_Accumbens mm9 No description Neural Nucleus Accumbens http...://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Neu.50.AllAg.Nucleus_Accumbens.bed ...

  14. File list: Pol.Neu.10.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available Pol.Neu.10.AllAg.Nucleus_Accumbens mm9 RNA polymerase Neural Nucleus Accumbens SRX2...09217,SRX209216,SRX209214,SRX209218,SRX209215,SRX209213 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.10.AllAg.Nucleus_Accumbens.bed ...

  15. File list: InP.Neu.20.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available InP.Neu.20.AllAg.Nucleus_Accumbens mm9 Input control Neural Nucleus Accumbens SRX20...9803,SRX791596,SRX791600,SRX209801,SRX209802,SRX472711,SRX445333,SRX445335,SRX445331 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Neu.20.AllAg.Nucleus_Accumbens.bed ...

  16. File list: Oth.Neu.20.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available Oth.Neu.20.AllAg.Nucleus_Accumbens mm9 TFs and others Neural Nucleus Accumbens SRX4...72713 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.20.AllAg.Nucleus_Accumbens.bed ...

  17. File list: Oth.Neu.05.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available Oth.Neu.05.AllAg.Nucleus_Accumbens mm9 TFs and others Neural Nucleus Accumbens SRX4...72713 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.05.AllAg.Nucleus_Accumbens.bed ...

  18. File list: Oth.Neu.10.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available Oth.Neu.10.AllAg.Nucleus_Accumbens mm9 TFs and others Neural Nucleus Accumbens SRX4...72713 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.10.AllAg.Nucleus_Accumbens.bed ...

  19. File list: His.Neu.20.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available His.Neu.20.AllAg.Nucleus_Accumbens mm9 Histone Neural Nucleus Accumbens SRX791594,S...2,SRX029231,SRX029230,SRX029228,SRX209198,SRX209196 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.20.AllAg.Nucleus_Accumbens.bed ...

  20. File list: NoD.Neu.20.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available NoD.Neu.20.AllAg.Nucleus_Accumbens mm9 No description Neural Nucleus Accumbens http...://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Neu.20.AllAg.Nucleus_Accumbens.bed ...

  1. File list: His.Neu.50.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available His.Neu.50.AllAg.Nucleus_Accumbens mm9 Histone Neural Nucleus Accumbens SRX791595,S...0,SRX209199,SRX209196,SRX209197,SRX209198,SRX209194 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.50.AllAg.Nucleus_Accumbens.bed ...

  2. File list: NoD.Neu.10.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available NoD.Neu.10.AllAg.Nucleus_Accumbens mm9 No description Neural Nucleus Accumbens http...://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Neu.10.AllAg.Nucleus_Accumbens.bed ...

  3. File list: His.Neu.05.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available His.Neu.05.AllAg.Nucleus_Accumbens mm9 Histone Neural Nucleus Accumbens SRX209200,S...7,SRX209211,SRX029230,SRX029232,SRX029228,SRX029231 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.05.AllAg.Nucleus_Accumbens.bed ...

  4. File list: Unc.Neu.10.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available Unc.Neu.10.AllAg.Nucleus_Accumbens mm9 Unclassified Neural Nucleus Accumbens SRX698...98892,SRX698891 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Neu.10.AllAg.Nucleus_Accumbens.bed ...

  5. File list: His.Neu.10.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available His.Neu.10.AllAg.Nucleus_Accumbens mm9 Histone Neural Nucleus Accumbens SRX791594,S...8,SRX209196,SRX209197,SRX209198,SRX209194,SRX029231 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.10.AllAg.Nucleus_Accumbens.bed ...

  6. File list: ALL.Neu.10.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available ALL.Neu.10.AllAg.Nucleus_Accumbens mm9 All antigens Neural Nucleus Accumbens SRX791...SRX445333,SRX472711,SRX445335,SRX445331,SRX029231 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.10.AllAg.Nucleus_Accumbens.bed ...

  7. File list: Pol.Neu.50.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available Pol.Neu.50.AllAg.Nucleus_Accumbens mm9 RNA polymerase Neural Nucleus Accumbens SRX2...09217,SRX209216,SRX209218,SRX209215,SRX209213,SRX209214 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.50.AllAg.Nucleus_Accumbens.bed ...

  8. File list: NoD.Neu.05.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available NoD.Neu.05.AllAg.Nucleus_Accumbens mm9 No description Neural Nucleus Accumbens http...://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Neu.05.AllAg.Nucleus_Accumbens.bed ...

  9. File list: Unc.Neu.05.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available Unc.Neu.05.AllAg.Nucleus_Accumbens mm9 Unclassified Neural Nucleus Accumbens SRX698...29238,SRX029235 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Neu.05.AllAg.Nucleus_Accumbens.bed ...

  10. File list: Pol.Neu.20.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available Pol.Neu.20.AllAg.Nucleus_Accumbens mm9 RNA polymerase Neural Nucleus Accumbens SRX2...09217,SRX209216,SRX209215,SRX209214,SRX209213,SRX209218 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.20.AllAg.Nucleus_Accumbens.bed ...

  11. File list: Oth.Neu.50.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available Oth.Neu.50.AllAg.Nucleus_Accumbens mm9 TFs and others Neural Nucleus Accumbens SRX4...72713 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.50.AllAg.Nucleus_Accumbens.bed ...

  12. File list: Unc.Neu.20.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available Unc.Neu.20.AllAg.Nucleus_Accumbens mm9 Unclassified Neural Nucleus Accumbens SRX698...29234,SRX029236 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Neu.20.AllAg.Nucleus_Accumbens.bed ...

  13. File list: InP.Neu.05.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available InP.Neu.05.AllAg.Nucleus_Accumbens mm9 Input control Neural Nucleus Accumbens SRX20...9803,SRX209802,SRX791596,SRX791600,SRX209801,SRX445333,SRX472711,SRX445335,SRX445331 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Neu.05.AllAg.Nucleus_Accumbens.bed ...

  14. File list: ALL.Neu.50.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available ALL.Neu.50.AllAg.Nucleus_Accumbens mm9 All antigens Neural Nucleus Accumbens SRX791...SRX445335,SRX209198,SRX445331,SRX209194,SRX029235 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.50.AllAg.Nucleus_Accumbens.bed ...

  15. File list: ALL.Neu.05.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available ALL.Neu.05.AllAg.Nucleus_Accumbens mm9 All antigens Neural Nucleus Accumbens SRX209...SRX472713,SRX445333,SRX472711,SRX445335,SRX445331 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.05.AllAg.Nucleus_Accumbens.bed ...

  16. File list: Unc.Neu.50.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available Unc.Neu.50.AllAg.Nucleus_Accumbens mm9 Unclassified Neural Nucleus Accumbens SRX029...98892,SRX029235 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Neu.50.AllAg.Nucleus_Accumbens.bed ...

  17. File list: InP.Neu.50.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available InP.Neu.50.AllAg.Nucleus_Accumbens mm9 Input control Neural Nucleus Accumbens SRX20...9801,SRX209802,SRX209803,SRX791600,SRX791596,SRX472711,SRX445333,SRX445335,SRX445331 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Neu.50.AllAg.Nucleus_Accumbens.bed ...

  18. File list: Pol.Neu.05.AllAg.Nucleus_Accumbens [Chip-atlas[Archive

    Full Text Available Pol.Neu.05.AllAg.Nucleus_Accumbens mm9 RNA polymerase Neural Nucleus Accumbens SRX2...09217,SRX209216,SRX209213,SRX209214,SRX209218,SRX209215 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.05.AllAg.Nucleus_Accumbens.bed ...

  19. 16O nucleus in the 4α cluster model

    16O nucleus is considered as a bound state of four α-particle cluster with 3α + α clusterization. A phenomenological potential is used for αα interaction. The additional three-body potentials are introduced ti bind the three- and four-particle systems. Parameters of these potentials have been chosen from the requirement to reproduce experimental values of binding energy and root-mean-square radius of 12C and 16O nuclei. The calculations have been performed on the basis of s-wave differential equations for Faddeev and Yakubovsky components of the total wave function. Ground and first exited states of the 16O nucleus are investigated. The most probable configuration of α particles in the 12C and 16O nuclei is determined. The charge form factors of the 12C and 16O nuclei are calculated. The results of the performed calculations are in a good agreement with experimental data

  20. Triple F - A Comet Nucleus Sample Return Mission

    Kueppers, Michael; Keller, H. U.; Kuehrt, E.; A'Hearn, M. F.; Altwegg, K.; Bertrand, R.; Busemann, H.; Capria, M. T.; Colangeli, L.; Davidsson, B.; Ehrenfreund, P.; Knollenberg, J.; Mottola, S.; Weiss, P.; Zolensky, M.; Akim, E.; Basilevsky, A.; Galimov, E.; Gerasimov, M.; Korablev, O.; Charnley, S.; Nittler, L. R.; Sandford, S.; Weissman, P.

    2008-01-01

    The Triple F (Fresh From the Fridge) mission, a Comet Nucleus Sample Return, has been proposed to ESA's Cosmic Vision program. A sample return from a comet enables us to reach the ultimate goal of cometary research. Since comets are the least processed bodies in the solar system, the proposal goes far beyond cometary science topics (like the explanation of cometary activity) and delivers invaluable information about the formation of the solar system and the interstellar molecular cloud from which it formed. The proposed mission would extract three sample cores of the upper 50 cm from three locations on a cometary nucleus and return them cooled to Earth for analysis in the laboratory. The simple mission concept with a touch-andgo sampling by a single spacecraft was proposed as an M-class mission in collaboration with the Russian space agency ROSCOSMOS.

  1. From Nucleons to Nucleus Concepts of Microscopic Nuclear Theory

    Suhonen, Jouni

    2007-01-01

    From Nucleons to Nucleus deals with single-particle and collective features of spherical nuclei. Each nuclear model is introduced and derived in detail. The formalism is then applied to light and medium-heavy nuclei in worked-out examples, and finally the acquired skills are strengthened by a wide selection of exercises, many relating the models to experimental data. Nuclear properties are discussed using particles, holes and quasiparticles. A large number of matrix elements of standard operators have been tabulated for reference. From Nucleons to Nucleus is based on lectures on nuclear physics given by the author. Its main scope is thus to serve as a textbook for advanced students. But also researchers will appreciate it as wellbalanced reference to theoretical nuclear physics.

  2. Meson production and Nuclear fragmentation of nucleus in the atmosphere

    Propagation of the primary and secondary cosmic ray in the atmosphere is calculated analitically. Two different cases of primary cosmic ray composition are used; the first case concerns the mixed composition of very heavy, heavy, middle, light nuclei and nucleons; and the second case considers only nucleons in the primary cosmic ray flux. The mechanism of multiple meson production is formulated according to the wounded nucleon model for nucleus-nucleus interaction and the scaling model for nucleon-nucleon interaction. The mechanism of nuclei fragmentation is formulated according to the experimental values of the fragmentation parameters at low energy. The calculated results of the electromagnetic flux are compared with the results of mountain experiments with large scale emulsion chamber and experimental data at airplane altitude. From these comparisons the calculation of electromagnetic flux altitude variation of the first case gives the best fit with experimental data than the second case. (author)

  3. Kinetic and Exchange Energy Densities near the Nucleus

    Lucian A. Constantin

    2016-04-01

    Full Text Available We investigate the behavior of the kinetic and the exchange energy densities near the nuclear cusp of atomic systems. Considering hydrogenic orbitals, we derive analytical expressions near the nucleus, for single shells, as well as in the semiclassical limit of large non-relativistic neutral atoms. We show that a model based on the helium iso-electronic series is very accurate, as also confirmed by numerical calculations on real atoms up to two thousands electrons. Based on this model, we propose non-local density-dependent ingredients that are suitable for the description of the kinetic and exchange energy densities in the region close to the nucleus. These non-local ingredients are invariant under the uniform scaling of the density, and they can be used in the construction of non-local exchange-correlation and kinetic functionals.

  4. Determination of the {\\eta}'-nucleus optical potential

    Nanova, M; Paryev, E Ya; Bayadilov, D; Bantes, B; Beck, R; Beloglazov, Y A; Böse, S; Brinkmann, K -T; Challand, Th; Crede, V; Dahlke, T; Dietz, F; Drexler, P; Eberhardt, H; Elsner, D; Ewald, R; Fornet-Ponse, K; Friedrich, S; Frommberger, F; Funke, Ch; Gottschall, M; Gridnev, A; Grüner, M; Gutz, E; Hammann, Ch; Hammann, D; Hannappel, J; Hartmann, J; Hillert, W; Hoffmeister, P; Honisch, Ch; Jaegle, I; Kaiser, D; Kalinowsky, H; Kammer, S; Keshelashvili, I; Kleber, V; Klein, F; Klempt, E; Krusche, B; Lang, M; Lopatin, I V; Maghrbi, Y; Makonyi, K; Müller, J; Odenthal, T; Piontek, D; Schaepe, S; Schmidt, Ch; Schmieden, H; Schmitz, R; Seifen, T; Thiel, A; Thoma, U; van Pee, H; Walther, D; Wendel, Ch; Wiedner, U; Wilson, A; Winnebeck, A; Zenke, F

    2013-01-01

    The excitation function and momentum distribution of $\\eta^\\prime$ mesons have been measured in photon induced reactions on $^{12}{}$C in the energy range of 1250-2600 MeV. The experiment was performed with tagged photon beams from the ELSA electron accelerator using the Crystal Barrel and TAPS detectors. The data are compared to model calculations to extract information on the sign and magnitude of the real part of the $\\eta^\\prime$-nucleus potential. Within the model, the comparison indicates an attractive potential of -($37 \\pm 10(stat)\\pm10(syst)$) MeV depth at normal nuclear matter density. Since the modulus of this depth is larger than the modulus of the imaginary part of the $\\eta^\\prime$-nucleus potential of -($10\\pm2.5$) MeV, determined by transparency ratio measurements, a search for resolved $\\eta^\\prime$-bound states appears promising.

  5. $K^+$-nucleus potentials from $K^+$-nucleon amplitudes

    Friedman, E

    2016-01-01

    Optical potentials for $K^+$-nucleus interactions are constructed from $K^+$-nucleon amplitudes using recently developed algorithm based on $K^+$-N kinematics in the nuclear medium. With the deep penetration of $K^+$ mesons into the nucleus at momenta below 800~MeV/c it is possible to test this approach with greater sensitivity than hitherto done with $K^-$ and pions. The energy-dependence of experimental reaction and total cross sections on nuclei is better reproduced with this approach compared to fixed-energy amplitudes. The inclusion of Pauli correlations in the medium also improves the agreement between calculation and experiment. The absolute scale of the cross sections is reproduced very well for $^6$Li but for C, Si and Ca calculated cross sections are (23$\\pm4$)\\% smaller than experiment, in agreement with earlier analyses. Two phenomenological models that produce such missing strength suggest that the imaginary part of the potential needs about 40\\% enhancement.

  6. Light new physics in coherent neutrino-nucleus scattering experiments

    deNiverville, Patrick; Ritz, Adam

    2015-01-01

    Experiments aiming to detect coherent neutrino-nucleus scattering present opportunities to probe new light weakly-coupled states, such as sub-GeV mass dark matter, in several extensions of the Standard Model. These states can be produced along with neutrinos in the collisions of protons with the target, and their production rate can be enhanced if there exists a light mediator produced on-shell. We analyze the sensitivity reach of several proposed experiments to light dark matter interacting with the Standard Model via a light vector mediator coupled to the electromagnetic current. We also determine the corresponding sensitivity to massless singlet neutrino-type states with interactions mediated by the baryon number current. In both cases we observe that proposed coherent neutrino-nucleus scattering experiments, such as COHERENT at the SNS and CENNS at Fermilab, will have sensitivity well beyond the existing limits.

  7. Pairing reentrance in warm rotating $^{104}$Pd nucleus

    Hung, N Quang; Agrawal, B K; Datar, V M; Mitra, A; Chakrabarty, D R

    2015-01-01

    Pairing reentrance phenomenon in the warm rotating $^{104}$Pd nucleus is studied within the Bardeen-Cooper-Schrieffer (BCS)-based approach (the FTBCS1). The theory takes into account the effect of quasiparticle number fluctuations on the pairing field at finite temperature and angular momentum within the pairing model plus noncollective rotation along the symmetry axis. The numerical calculations for the pairing gaps and nuclear level densities (NLD), of which an anomalous enhancement has been experimentally observed at low excitation energy $E^*$ and high angular momentum $J$, show that the pairing reentrance is seen in the behavior of pairing gap obtained within the FTBCS1 at low $E$ and high $J$. This leads to the enhancement of the FTBCS1 level densities, in good agreement with the experimental observation. This agreement indicates that the observed enhancement of the NLD might be the first experimental detection of the pairing reentrance in a finite nucleus.

  8. Efficient And Portable SDR Waveform Development: The Nucleus Concept

    Ramakrishnan, Venkatesh; Kempf, Torsten; Kammler, David; Ascheid, Gerd; Meyr, Heinrich; Adrat, Marc; Antweiler, Markus

    2009-01-01

    Future wireless communication systems should be flexible to support different waveforms (WFs) and be cognitive to sense the environment and tune themselves. This has lead to tremendous interest in software defined radios (SDRs). Constraints like throughput, latency and low energy demand high implementation efficiency. The tradeoff of going for a highly efficient implementation is the increase of porting effort to a new hardware (HW) platform. In this paper, we propose a novel concept for WF development, the Nucleus concept, that exploits the common structure in various wireless signal processing algorithms and provides a way for efficient and portable implementation. Tool assisted WF mapping and exploration is done efficiently by propagating the implementation and interface properties of Nuclei. The Nucleus concept aims at providing software flexibility with high level programmability, but at the same time limiting HW flexibility to maximize area and energy efficiency.

  9. Coulomb Excitation of the N = 50 nucleus 80Zn

    Neutron rich Zinc isotopes, including the N = 50 nucleus 80Zn, were produced and post-accelerated at the Radioactive Ion Beam (RIB) facility REX-ISOLDE (CERN). Low-energy Coulomb excitation was induced on these isotopes after post-acceleration, yielding B(E2) strengths to the first excited 2+ states. For the first time, an excited state in 80Zn was observed and the 21+ state in 78Zn was established. The measured B(E2,21+→01+) values are compared to two sets of large scale shell model calculations. Both calculations reproduce the observed B(E2) systematics for the full Zinc isotopic chain. The results for N = 50 isotones indicate a good N = 50 shell closure and a strong Z = 28 proton core polarization. The new results serve as benchmarks to establish theoretical models, predicting the nuclear properties of the doubly magic nucleus 78Ni

  10. Electromagnetic properties of the Beryllium-11 nucleus in Halo EFT

    Hammer H.-W.

    2010-04-01

    Full Text Available We compute electromagnetic properties of the Beryllium-11 nucleus using an effective field theory that exploits the separation of scales in this halo system. We fix the parameters of the EFT from measured data on levels and scattering lengths in the 10Be plus neutron system. We then obtain predictions for the B(E1 strength of the 1/2+ to 1/2− transition in the 11Be nucleus. We also compute the charge radius of the ground state of 11Be. Agreement with experiment within the expected accuracy of a leading-order computation in this EFT is obtained. We also indicate how higher-order corrections that affect both s-wave and p-wave 10 Be-neutron interactions will affect our results.

  11. Towards a Deeper Understanding of the Nucleus with Exotic Nuclei

    Ormand, Erich

    2006-10-01

    Despite more than fifty years of study, many questions about now nuclei are put together remain. While nuclei near the valley of stability have provided a wealth of information, they are not sufficient to provide us with a comprehensive and unified description of the nucleus. Especially lacking is an accurate picture of those exotic species that are the basis of cosmic alchemy. The missing pieces in the puzzle can be filled in with a determined experimental and theoretical effort focusing on nuclei lying far from the valley of stability. Here, I will outline the intellectual challenges that can be addressed by proposed exotic-beam facilities, and how new experimental data will quide and refine theoretical descriptions of the nucleus.

  12. Maps of interaural delay in the owl's nucleus laminaris.

    Carr, Catherine E; Shah, Sahil; McColgan, Thomas; Ashida, Go; Kuokkanen, Paula T; Brill, Sandra; Kempter, Richard; Wagner, Hermann

    2015-09-01

    Axons from the nucleus magnocellularis form a presynaptic map of interaural time differences (ITDs) in the nucleus laminaris (NL). These inputs generate a field potential that varies systematically with recording position and can be used to measure the map of ITDs. In the barn owl, the representation of best ITD shifts with mediolateral position in NL, so as to form continuous, smoothly overlapping maps of ITD with iso-ITD contours that are not parallel to the NL border. Frontal space (0°) is, however, represented throughout and thus overrepresented with respect to the periphery. Measurements of presynaptic conduction delay, combined with a model of delay line conduction velocity, reveal that conduction delays can account for the mediolateral shifts in the map of ITD. PMID:26224776

  13. Antiproton-Nucleus Interaction and Coulomb Effect at High Energies

    ZHOU Li-Juan; WU Qing; GU Yun-Ting; MA Wei-Xing; TAN Zhen-Qiang; HU Zhao-Hui

    2005-01-01

    The Coulomb effect in high energy antiproton-nucleus elastic and inelastic scattering from 12C and 16O is studied in the framework of Glauber multiple scattering theory for five kinetic energies ranged from 0.23 to 1.83 GeV.A microscopic shell-model nuclear wave functions, Woods-Saxon single-particle wave functions, and experimental pN amplitudes are used in the calculations. The results show that the Coulomb effect is of paramount importance for filling up the dips of differential cross sections. We claim that the present result for inelastic scattering of antiproton-12C is sufficiently reliable to be a guide for measurements in the very near future. We also believe that antiproton nucleus elastic and inelastic scattering may produce new information on both the nuclear structure and the antinucleon-nucleon interaction, in particular the p-neutron interaction.

  14. The identification of musical instruments through nucleus cochlear implants.

    Grasmeder, M L; Lutman, M E

    2006-09-01

    In this study, self-reported ability to recognize musical instruments was investigated by means of a questionnaire, which was sent to a group of adult Nucleus cochlear implant users and a group of normally hearing subjects. In addition, spectrograms and electrodograms were produced and analysed for samples of music played on 10 different musical instruments. Self-reported ability to recognize some instruments was poor in the group of implant users, particularly for the saxophone, tuba and clarinet. Electrodograms showed that these instruments could only be identified using distorted spectral information or reduced temporal information. Other instruments, such as the drum and piano, could be identified using temporal information. Limited spectral resolution makes the recognition of musical instruments difficult for Nucleus implant users. PMID:18792382

  15. Pionic properties of the nucleus and the EMC effect

    One expects certain modifications of the structure of a nucleus inside the nuclear medium. The EMC effect is a striking example, which displays modifications of the quark structure. In these lectures I discuss the traditional nuclear physics viewpoint for the interpretation of this effect. It is based in the modification of the pion cloud and the existence of the a pion excess, for which I discuss the experimental evidence. In particular the e.m polarizability of a free nucleon is dominated by the pion cloud. It is changed in the nucleus, which reflects the distortion of the pion cloud. I also discuss the exchange effects of the Compton scattering amplitude, which are linked to the existence of a pion excess

  16. Charge, neutron, and weak size of the atomic nucleus

    Hagen, G; Forssén, C; Jansen, G R; Nazarewicz, W; Papenbrock, T; Wendt, K A; Bacca, S; Barnea, N; Carlsson, B; Drischler, C; Hebeler, K; Hjorth-Jensen, M; Miorelli, M; Orlandini, G; Schwenk, A; Simonis, J

    2015-01-01

    What is the size of the atomic nucleus? This deceivably simple question is difficult to answer. While the electric charge distributions in atomic nuclei were measured accurately already half a century ago, our knowledge of the distribution of neutrons is still deficient. In addition to constraining the size of atomic nuclei, the neutron distribution also impacts the number of nuclei that can exist and the size of neutron stars. We present an ab initio calculation of the neutron distribution of the neutron-rich nucleus $^{48}$Ca. We show that the neutron skin (difference between radii of neutron and proton distributions) is significantly smaller than previously thought. We also make predictions for the electric dipole polarizability and the weak form factor; both quantities are currently targeted by precision measurements. Based on ab initio results for $^{48}$Ca, we provide a constraint on the size of a neutron star.

  17. Quasiparticle features and level statistics of odd-odd nucleus

    The energy levels of the odd-odd nucleus 84Y are calculated by using the axially symmetric rotor plus quasiparticles model. The two standard statistical tests of Random-Matrix Theory such as the distribution function p(s) of the nearest-neighbor level spacings (NNS) and the spectral rigidity Δ3 are used to explore the statistical properties of the energy levels. By analyzing the properties of p(s) and Δ3 under various conditions, the authors find that the quasiparticle features mainly affect the statistical properties of the odd-odd nucleus 84Y through the recoil term and the Coriolis force in this theoretical mode, and that the chaotic degree of the energy levels decreases with the decreasing of the Fermi energy and the energy-gap parameters. The effect of the recoil term is small while the Coriolis force plays a major role in the spectral structure of 84Y

  18. QCD evolution of the gluon density in a nucleus

    The Glauber approach to the gluon density in a nucleus, suggested by A. Mueller, is developed and studied in detail. Using the GRV parameterization for the gluon density in a nucleon, the value as well as energy and Q2 dependence of the gluon density in a nucleus is calculated. It is shown that the shadowing corrections are under theoretical control and are essential in the region of small x. The change crucially the value of the gluon density as well as the value of the anomalous dimension of the nuclear structure function, unlike of the nucleon one. The systematic theoretical way to treat the correction to the Glauber approach is developed and a new evolution equation is derived and solved. It is shown that the solution of the new evolution equation can provide a self consistent matching of 'soft' high energy phenomenology with 'hard' QCD physics. (author). 51 refs., 25 figs., 1 tab

  19. Collective effects of supernova explosions in a starbusrst nucleus

    The collective effects of supernova (SN) explosions in the nucleus of a starburst galaxy are studied. It is shown that a large wind bubble with the size of a few hundred parsecs in the nucleus of a starburst galaxy will expand for SN explosion rates of 0.1 per year of greater. The bubble gradually elongates due to density stratification. Finally, the shell breaks near the top and the hot matter flows through the cylindrical shell up to 1--2 kpc above the disk plane. The authors discuss the x-ray emission in the halos of galaxies such as M82 and NGC 253 and the distribution of molecular gas in such galaxies in relation to the starburst phenomenon

  20. Connections of the lateral reticular nucleus to the lateral vestibular nucleus in the rat. An anterograde tracing study with Phaseolus vulgaris leucoagglutinin

    Ruigrok, Tom; Cella, Massimo; Voogd, J.

    1995-01-01

    textabstractEfferent projections from the lateral reticular nucleus in the rat were investigated with anterograde transport of Phaseolus vulgaris leucoagglutinin. Besides the well known mossy fibre connections to the cerebellar cortex and collaterals to the cerebellar nuclei, a substantial bilateral projection to the lateral vestibular nucleus was found. Terminal arborizations found within this nucleus appeared to detach from the reticulocerebellar fibres in the cerebellar white matter and en...

  1. Ferrofluid nucleus phase transitions in an external uniform magnetic field

    Tanygin, B. M.; Shulyma, S. I.; Kovalenko, V. F.; Petrychuk, M.V.

    2015-01-01

    The phase transition between a massive dense phase and a diluted superparamagnetic phase has been studied by means of a direct molecular dynamics simulation. The equilibrium structures of the ferrofluid aggregate nucleus are obtained for different values of a temperature and an external magnetic field magnitude. An approximate match of experiment and simulation has been shown for the ferrofluid phase diagram coordinates "field-temperature". The provided phase coexistence curve has an opposite...

  2. Morphological differences in the lateral geniculate nucleus associated with dyslexia

    Mónica Giraldo-Chica; John P. Hegarty, II; Keith A. Schneider

    2015-01-01

    Developmental dyslexia is a common learning disability characterized by normal intelligence but difficulty in skills associated with reading, writing and spelling. One of the most prominent, albeit controversial, theories of dyslexia is the magnocellular theory, which suggests that malfunction of the magnocellular system in the brain is responsible for the behavioral deficits. We sought to test the basis of this theory by directly measuring the lateral geniculate nucleus (LGN), the only locat...

  3. GlyT2+ Neurons in the Lateral Cerebellar Nucleus

    Uusisaari, Marylka; Knöpfel, Thomas

    2009-01-01

    The deep cerebellar nuclei (DCN) are a major hub in the cerebellar circuitry but the functional classification of their neurons is incomplete. We have previously characterized three cell groups in the lateral cerebellar nucleus: large non-GABAergic neurons and two groups of smaller neurons, one of which express green fluorescence protein (GFP) in a GAD67/GFP mouse line and is therefore GABAergic. However, as a substantial number of glycinergic and glycine/GABA co-expressing neurons have been ...

  4. Maternal control of the fetal and neonatal rat suprachiasmatic nucleus

    El-Hennamy, Rehab; Matějů, Kristýna; Bendová, Zdeňka; Sosniyenko, Serhiy; Sumová, Alena

    Destin: SRBR, 2008. s. 191-192. [Anniversary Meeting Society for Research on Biological Rhythms /20./. 17.05.2008-21.05.2008, Destin] R&D Projects: GA ČR GA309/08/0503; GA MŠk(CZ) LC554 Grant ostatní: EUCLOCK(XE) 018741 Institutional research plan: CEZ:AV0Z50110509 Source of funding: R - rámcový projekt EK Keywords : spo2 * suprachiasmatic nucleus * rat * development Subject RIV: FH - Neurology

  5. ETA-mesic nucleus: a new nuclear species

    The strong-interaction dynamics of the eta N system can cause the eta meson to be captured into nuclear orbitals in nuclei with mass numbers greater than 10. A prediction for what should be the experimental signature of the formation of an eta-mesic nucleus is presented and a forthcoming experiment at Brookhaven is described briefly. The scientific significance of the eta-mesic nuclei is also discussed. 4 refs., 3 figs

  6. The Ionization Source in the Nucleus of M84

    Bower, G. A.; Green, R. F.; Quillen, A. C.; Danks, A.; Malumuth, E. M.; Gull, T.; Woodgate, B.; Hutchings, J.; Joseph, C.; Kaiser, M. E.

    2000-01-01

    We have obtained new Hubble Space Telescope (HST) observations of M84, a nearby massive elliptical galaxy whose nucleus contains a approximately 1.5 X 10(exp 9) solar mass dark compact object, which presumably is a supermassive black hole. Our Space Telescope Imaging Spectrograph (STIS) spectrum provides the first clear detection of emission lines in the blue (e.g., [0 II] lambda 3727, HBeta and [0 III] lambda lambda4959,5007), which arise from a compact region approximately 0".28 across centered on the nucleus. Our Near Infrared Camera and MultiObject Spectrometer (NICMOS) images exhibit the best view through the prominent dust lanes evident at optical wavelengths and provide a more accurate correction for the internal extinction. The relative fluxes of the emission lines we have detected in the blue together with those detected in the wavelength range 6295 - 6867 A by Bower et al. indicate that the gas at the nucleus is photoionized by a nonstellar process, instead of hot stars. Stellar absorption features from cool stars at the nucleus are very weak. We update the spectral energy distribution of the nuclear point source and find that although it is roughly flat in most bands, the optical to UV continuum is very red, similar to the spectral energy distribution of BL Lac. Thus, the nuclear point source seen in high-resolution optical images is not a star cluster but is instead a nonstellar source. Assuming isotropic emission from this source, we estimate that the ratio of bolometric luminosity to Eddington luminosity is about 5 x 10(exp -7). However, this could be underestimated if this source is a misaligned BL Lac object, which is a possibility suggested by the spectral energy distribution and the evidence of optical variability we describe.

  7. Cardiovascular responses to hydrogen peroxide into the nucleus tractus solitarius

    Cardoso, Leonardo Máximo; Colombari, Débora Simões Almeida; Menani, José V; Toney, Glenn M.; Chianca, Deoclécio Alves; Colombari, Eduardo

    2009-01-01

    The nucleus tractus solitarius (NTS), a major hindbrain area involved in cardiovascular regulation, receives primary afferent fibers from peripheral baroreceptors and chemoreceptors. Hydrogen peroxide (H2O2) is a relatively stable and diffusible reactive oxygen species (ROS), which acting centrally, may affect neural mechanisms. In the present study, we investigated effects of H2O2 alone or combined with the glutamatergic antagonist kynurenate into the NTS on mean arterial pressure (MAP) and ...

  8. Three-dimensional organization of the human interphase nucleus.

    Knoch, Tobias; Münkel, Christian; Waldeck, Waldemar; Langowski, Jörg

    2002-01-01

    textabstractDespite the successful linear sequencing of the human genome its three-dimensional structure is widely unknown, although it is important for gene regulation and replication. For a long time the interphase nucleus has been viewed as a 'spaghetti soup' of DNA without much internal structure, except during cell division. Only recently has it become apparent that chromosomes occupy distinct 'territories' also in interphase. Two models for the detailed folding of the 30 nm chromatin fi...

  9. Nucleus accumbens lesions modulate the effects of Methylphenidate

    Podet, Adam; Lee, Min J.; Swann, Alan C.; Dafny, Nachum

    2010-01-01

    The psychostimulant methylphenidate (MPD, Ritalin) is the prescribed drug of choice for treatment of ADHD. In recent years, the diagnosis rate of ADHD has increased dramatically, as have the number of MPD prescriptions. Repeated exposure to psychostimulants produces behavioral sensitization in rats, an experimental indicator of a drug’s potential liability. In studies on cocaine and amphetamine, this effect has been reported to involve the nucleus accumbens (NAc), one of the nuclei belonging ...

  10. Finite size of nucleus and vacuum polarization in heavy atoms

    The effect of the finite nuclear size R for the induced-charge density is discussed. Simple analytical expression for the corresponding variation δρ is obtained at the distances much larger than R. It is shown that in heavy atoms is distinct essentially from the result obtained with the use of the lowest order of perturbation theory with respect to the difference between the Coulomb potential and the real potential of nucleus. 19 refs.; 3 figs

  11. Common Synaptic Input to the Human Hypoglossal Motor Nucleus

    Laine, Christopher M.; Bailey, E. Fiona

    2010-01-01

    The tongue plays a key role in various volitional and automatic functions such as swallowing, maintenance of airway patency, and speech. Precisely how hypoglossal motor neurons, which control the tongue, receive and process their often concurrent input drives is a subject of ongoing research. We investigated common synaptic input to the hypoglossal motor nucleus by measuring the coordination of spike timing, firing rate, and oscillatory activity across motor units recorded from unilateral (i....

  12. Surgical probe and implant development for nucleus pulposus replacements

    Schmocker, Andreas

    2016-01-01

    Intervertebral disc degeneration is a major reason why we experience low back pain. Intervertebral discs are located in-between the vertebrae of the spine. They act, among other, as shock absorbers by distributing the mechanical load applied to the spine while giving it its range of motion. An intervertebral disc is composed of a center - a soft core, called nucleus pulposus which is surrounded by a strong ring called the annulus fibrosus. By disc degeneration, we mean a physical deterioratio...

  13. Deciphering new roles for lipids in the cell nucleus

    Hozák, Pavel

    Istanbul : Medical Biology and Genetics Society, 2013. [National Congress of Medical Biology and Genetics /13./. 27.10.2013-20.10.2013, Kusadasi] R&D Projects: GA ČR GAP305/11/2232; GA TA ČR TE01020118; GA MŠk LD12063; GA MŠk LH12143 Institutional support: RVO:68378050 Keywords : cell nucleus * chromatin * nucleolus * nuclear myosin * PIP2 * 3D electron tomography * super-resolution microscopy Subject RIV: EB - Genetics ; Molecular Biology

  14. Cellular effects of swim stress in the dorsal raphe nucleus

    Kirby, Lynn G.; Pan, Yu-Zhen; Freeman-Daniels, Emily; Rani, Shobha; Nunan, John D.; Akanwa, Adaure; Beck, Sheryl G

    2007-01-01

    Swim stress regulates forebrain 5-hydroxytryptamine (5-HT) release in a complex manner and its effects are initiated in the serotonergic dorsal raphe nucleus (DRN). The purpose of this study was to examine the effects of swim stress on the physiology of DRN neurons in conjunction with 5-HT immunohistochemistry. Basic membrane properties, 5-HT1A and 5-HT1B receptor-mediated responses and glutamatergic excitatory postsynaptic currents (EPSCs) were measured using whole-cell patch clamp technique...

  15. Nucleus accumbens core lesions enhance two-way active avoidance

    Lichtenberg, Nina T.; Kashtelyan, Vadim; Burton, Amanda C.; Bissonette, Gregory B.; Roesch, Matthew R.

    2013-01-01

    The majority of work examining nucleus accumbens core (NAc) has focused on functions pertaining to behaviors guided by appetitive outcomes. These studies have pointed to NAc as being critical for motivating behavior toward desirable outcomes. For example, we have recently shown that lesions of NAc impaired performance on a reward-guided decision-making task that required rats to choose between differently valued rewards. Unfortunately, much less is known about the role that NAc plays in motiv...

  16. Calculation of light nucleus reaction cross sections in Geant4

    Uzhinsky, V.

    2012-01-01

    Total reaction cross sections of light projectile nucleus (H-2, H-3, He-3 and He-4) interactions with nuclei are calculated using Geant4 models, and compared with experimental data. It is shown that the models give various predictions at low energies, in the region of the Coulomb barrier. "Shen model" (W.-Q. Shen et al., Nucl. Phys. {\\bf A491} (1989) 130) is identified as an improvement over other models.

  17. Hidden Glashow resonance in neutrino-nucleus collisions

    Alikhanov, I.

    2016-05-01

    Today it is widely believed that s-channel excitation of an on-shell W boson, commonly known as the Glashow resonance, can be initiated in matter only by the electron antineutrino in the process νbaree- →W- at the laboratory energy around 6.3 PeV. In this Letter we argue that the Glashow resonance within the Standard Model also occurs in neutrino-nucleus collisions. The main conclusions are as follows. 1) The Glashow resonance can be excited by both neutrinos and antineutrinos of all the three flavors scattering in the Coulomb field of a nucleus. 2) The Glashow resonance in a neutrino-nucleus reaction does not manifest itself as a Breit-Wigner-like peak in the cross section but the latter exhibits instead a slow logarithmic-law growth with the neutrino energy. The resonance turns thus out to be hidden. 3) More than 98% of W bosons produced in the sub-PeV region in neutrino-initiated reactions in water/ice will be from the Glashow resonance. 4) The vast majority of the Glashow resonance events in a neutrino detector are expected at energies from a few TeV to a few tens of TeV, being mostly initiated by the conventional atmospheric neutrinos dominant in this energy range. Calculations of the cross sections for Glashow resonance excitation on the oxygen nucleus as well as on the proton are carried out in detail. The results of this Letter can be useful for studies of neutrino interactions at large volume water/ice neutrino detectors. For example, in the IceCube detector one can expect 0.3 Glashow resonance events with shower-like topologies and the deposited energies above 300 TeV per year. It is therefore likely already to have at least one Glashow resonance event in the IceCube data set.

  18. Total cross sections for neutron-nucleus scattering

    Suryanarayana, S. V.; H. Naik; Ganesan, S; Kailas, S; Choudhury, R. K.; Kim, Guinyum

    2010-01-01

    Systematics of neutron scattering cross sections on various materials for neutron energies up to several hundred MeV are important for ADSS applications. Ramsauer model is well known and widely applied to understand systematics of neutron nucleus total cross sections. In this work, we examined the role of nuclear effective radius parameter (r$_0$) on Ramsauer model fits of neutron total cross sections. We performed Ramsauer model global analysis of the experimental neutron total cross section...

  19. Eikonal approximation to deuteron-nucleus scattering at intermediate energies

    The full integral representation of the eikonal approximation to the scattering amplitude of spin-1 elastic scattering in the presence of central, spin-orbit and tensor interactions is derived. Eikonal calculations of the cross section and polarization observables in deuteron-nucleus scattering at intermediate energies using a relativistic model are found to reproduce successfully the partial wave calculations. copyright 1997 The American Physical Society

  20. Extended Glauber theory and its application in halo nucleus scattering

    The authors introduced an extended Glauber theory for a halo nucleus scattering, where the halo nucleons and the nuclear core were treated separately. Expressions of reaction and interaction cross sections of the halo nucleus scattering were derived. The authors took the halo structure of the projectile nucleus into account and adopted an improved optical-limit approximation. In the framework of the extended Glauber theory, the authors studied the reaction cross section for the halo nucleus 14Be scattering on a target 12C. For comparison, the reaction cross sections of 12Be + 12C were calculated as well. The density distribution of target 12C is taken from experiments, and those of the projectiles 12Be and 14Be were obtained by two methods. One is that the harmonic oscillator wave functions for 12Be and 14Be are used. The length of harmonic oscillator is adjusted to reproduce the reaction cross section of 12Be + 12C at the high energy E = 790 MeV/u. the density distribution of 14Be was also calculated self-consistently in the relativistic mean field (RMF) theory, with a long tail wave functions for the two neutrons in 14Be. It was found that the calculated reaction cross sections for 12Be + 12C at E = 790 MeV/u and E = 56.5 MeV/u were in good agreement with the experimental data no mater harmonic oscillator or RMF wave functions were used. In contrast, the experiments of the reaction cross sections for 14Be + 12C could only be reproduced when the wave functions of two 2s1/2 neutrons spread over with a long tail. It comes to a conclusion that two outside neutrons in 14Be form a halo structure

  1. Theory and phenomenology of coherent neutrino-nucleus scattering

    We review the theory and phenomenology of coherent elastic neutrino-nucleus scattering (CEνNS). After a brief introduction, we summarize the places where CEνNS is already in use and then turn to future physics opportunities from CEνNS. CEνNS has been proposed as a way to limit or discover beyond the standard model physics, measure the nuclear-neutron radius and constrain the Weinberg angle

  2. Theoretical estimates of cross sections for neutron-nucleus collisions

    Mukhopadhyay, Tapan; Lahiri, Joydev; Basu, D. N.

    2010-01-01

    We construct an analytical model derived from nuclear reaction theory and having a simple functional form to demonstrate the quantitative agreement with the measured cross sections for neutron induced reactions. The neutron-nucleus total, reaction and scattering cross sections, for energies ranging from 5 to 700 MeV and for several nuclei spanning a wide mass range are estimated. Systematics of neutron scattering cross sections on various materials for neutron energies upto several hundred Me...

  3. High-energy pion-nucleus elastic scattering

    Chen, C. M.; Ernst, D. J.; Johnson, M B

    1992-01-01

    We investigate theoretical approaches to pion--nucleus elastic scattering at high energies (300 $\\le T_\\pi \\le$ 1 GeV). A ``model--exact'' calculation of the lowest--order microscopic optical model, carried out in momentum space and including the full Fermi averaging integration, a realistic off--shell pion--nucleon scattering amplitude and fully covariant kinematics, is used to calibrate a much simpler theory. The simpler theory utilizes a local optical potential with an eikonal propagator a...

  4. Integration of sensory quanta in cuneate nucleus neurons in vivo.

    Fredrik Bengtsson

    Full Text Available Discriminative touch relies on afferent information carried to the central nervous system by action potentials (spikes in ensembles of primary afferents bundled in peripheral nerves. These sensory quanta are first processed by the cuneate nucleus before the afferent information is transmitted to brain networks serving specific perceptual and sensorimotor functions. Here we report data on the integration of primary afferent synaptic inputs obtained with in vivo whole cell patch clamp recordings from the neurons of this nucleus. We find that the synaptic integration in individual cuneate neurons is dominated by 4-8 primary afferent inputs with large synaptic weights. In a simulation we show that the arrangement with a low number of primary afferent inputs can maximize transfer over the cuneate nucleus of information encoded in the spatiotemporal patterns of spikes generated when a human fingertip contact objects. Hence, the observed distributions of synaptic weights support high fidelity transfer of signals from ensembles of tactile afferents. Various anatomical estimates suggest that a cuneate neuron may receive hundreds of primary afferents rather than 4-8. Therefore, we discuss the possibility that adaptation of synaptic weight distribution, possibly involving silent synapses, may function to maximize information transfer in somatosensory pathways.

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

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

    2015-10-01

    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

  6. An Automatic Learning-Based Framework for Robust Nucleus Segmentation.

    Xing, Fuyong; Xie, Yuanpu; Yang, Lin

    2016-02-01

    Computer-aided image analysis of histopathology specimens could potentially provide support for early detection and improved characterization of diseases such as brain tumor, pancreatic neuroendocrine tumor (NET), and breast cancer. Automated nucleus segmentation is a prerequisite for various quantitative analyses including automatic morphological feature computation. However, it remains to be a challenging problem due to the complex nature of histopathology images. In this paper, we propose a learning-based framework for robust and automatic nucleus segmentation with shape preservation. Given a nucleus image, it begins with a deep convolutional neural network (CNN) model to generate a probability map, on which an iterative region merging approach is performed for shape initializations. Next, a novel segmentation algorithm is exploited to separate individual nuclei combining a robust selection-based sparse shape model and a local repulsive deformable model. One of the significant benefits of the proposed framework is that it is applicable to different staining histopathology images. Due to the feature learning characteristic of the deep CNN and the high level shape prior modeling, the proposed method is general enough to perform well across multiple scenarios. We have tested the proposed algorithm on three large-scale pathology image datasets using a range of different tissue and stain preparations, and the comparative experiments with recent state of the arts demonstrate the superior performance of the proposed approach. PMID:26415167

  7. Examining the Structure of the Oxygen-16 Nucleus

    Sauer, Ethan; Aprahamian, Ani; Tan, Wanpeng; Gyurjinyan, Armen; Frentz, Bryce; Guerin, Benjamin

    2015-10-01

    The intent of this work is to explore the structure of the nucleus of Oxygen-16 (16O), which consists of four alpha particles, each with two protons and two neutrons. 16O is generated via the fusion of helium and carbon during stellar nucleosynthesis. This reaction is crucial to the existence of life. By measuring the structure of the 16O nucleus, we hope to gain a better understanding of stellar evolution and processes. The theoretical state of most interest is a linear arrangement of the four alpha particles, proposed by Chevallier et al. in their 1967 paper to explain the surprisingly large moment of inertia of the nucleus they measured. The existence of this state can be most accurately observed through an analysis of the energy spectra of the decay products. This method has previously been implemented at Notre Dame by Freer et al. when a similar structure, that of Carbon-12 (12C), was analyzed, and a previously unknown state was observed. The data gathered is analyzed using the method of angular correlation, which makes use of the angles and energies of decay products relative to the center of mass frame to reconstruct possible spins of the initial state. Analysis is currently underway and results will be presented at CEU 2015. Supported by NSF Grant PHY-1419765.

  8. N body simulations of the nucleus of M 31

    Emsellem, E; Emsellem, Eric; Combes, Francoise

    1997-01-01

    We test through stellar N-body simulations some scenarios to explain the dynamics of the peculiar nucleus of the Andromeda galaxy (M~31): although HST observations reveal a double nucleus morphology, the rotation field is almost symmetric around the bulge gravity centre and the velocity dispersion is off-centred. We show that any m=1 perturbation has a very short life-time (a few 10$^5$ yr). Assuming that the bright peak (P1) is a cold stellar cluster infalling into the nucleus, and that the large central velocity gradient is due to a central dark mass (in the range 7~$10^7$--$10^8$~\\Msun), we obtain a reasonably good fit to the observations. However, if this cluster lies in the central 20 pc, we estimate the life-time of the cluster to be less than 0.5~Myr. The dynamical friction is more efficient than estimated by analytic formulae, and is essentially due to the deformation of the stellar cluster through the huge tidal forces provided by the black hole. We show that the cluster cannot be on a circular orbit...

  9. Relief memory consolidation requires protein synthesis within the nucleus accumbens.

    Bruning, Johann E A; Breitfeld, Tino; Kahl, Evelyn; Bergado-Acosta, Jorge R; Fendt, Markus

    2016-06-01

    Relief learning refers to the association of a stimulus with the relief from an aversive event. The thus-learned relief stimulus then can induce, e.g., an attenuation of the startle response or approach behavior, indicating positive valence. Previous studies revealed that the nucleus accumbens is essential for the acquisition and retrieval of relief memory. Here, we ask whether the nucleus accumbens is also the brain site for consolidation of relief memory into a long-term form. In rats, we blocked local protein synthesis within the nucleus accumbens by local infusions of anisomycin at different time points during a relief conditioning experiment. Accumbal anisomycin injections immediately after the relief conditioning session, but not 4 h later, prevented the consolidation into long-term relief memory. The retention of already consolidated relief memory was not affected by anisomycin injections. This identifies a time window and site for relief memory consolidation. These findings should complement our understanding of the full range of effects of adverse experiences, including cases of their distortion in humans such as post-traumatic stress disorder and/or phobias. PMID:26792192

  10. Compound nucleus formation in reactions between massive nuclei: Fusion barrier

    The evaporation residue cross sections σER in reactions between massive nuclei have been analyzed within different models of complete fusion. The calculations in the framework of the optical model, the surface friction model, and the macroscopic dynamic model can give the results which are by few orders of magnitude different from experimental data. This takes place due to neglect of the competition between complete fusion and quasifission. A possible mechanism of compound nucleus formation in heavy-ion-induced reactions has been suggested. The analysis of the complete fusion of nuclei on the basis of dinuclear system approach has allowed one to reveal an important feature of the fusion process of massive nuclei, that is, the appearance of the fusion barrier during dinuclear system evolution to a compound nucleus. As a result, the competition between complete fusion and quasifission arises and strongly reduces the cross section of the compound nucleus formation. A model is proposed for calculation of this competition in a massive symmetric dinuclear system. This model is applied for collision energies above the Coulomb barrier. The σER values calculated in the framework of dinuclear system approach seem to be close to the experimental data. For illustration the reactions 100Mo+100Mo, 110Pd+110Pd, and 124Sn+96Zr have been considered

  11. Pictures of Particle Production in Proton-Nucleus Collisions

    Mueller, Alfred H

    2016-01-01

    This work focuses on gluon(jet) production in dilute(proton)-dense(nucleus) collisions. Depending on the frame and gauge, gluon production can be viewed as a freeing of gluons coming from either the proton wave function or from the nucleus wave function. These (apparently) very different pictures must lead to the same result and the purpose of this paper is to see how that happens. The focus is on gluons having $k_\\perp\\sim Q_S$ or gluons in the scaling region $k_\\perp/Q_S\\gg 1$. In the McLerran-Venugopalan(MV) model with $k_\\perp\\sim Q_S$ we are able to derive gluon production in a way that (graphically) manifestly shows $k_\\perp$-factorization in terms of the number density of gluons in the nuclear wave function. We presume that this picture, and $k_\\perp$-factorization, continues to hold in the presence of small-$x$ evolution although we have not been able to explicitly verify this. Our result is in agreement with usual $k_\\perp$-factorization where the gluon number density of the nucleus does not appear i...

  12. Incorporation of mammalian actin into microfilaments in plant cell nucleus

    Paves Heiti

    2004-04-01

    Full Text Available Abstract Background Actin is an ancient molecule that shows more than 90% amino acid homology between mammalian and plant actins. The regions of the actin molecule that are involved in F-actin assembly are largely conserved, and it is likely that mammalian actin is able to incorporate into microfilaments in plant cells but there is no experimental evidence until now. Results Visualization of microfilaments in onion bulb scale epidermis cells by different techniques revealed that rhodamine-phalloidin stained F-actin besides cytoplasm also in the nuclei whereas GFP-mouse talin hybrid protein did not enter the nuclei. Microinjection of fluorescently labeled actin was applied to study the presence of nuclear microfilaments in plant cells. Ratio imaging of injected fluorescent rabbit skeletal muscle actin and phalloidin staining of the microinjected cells showed that mammalian actin was able to incorporate into plant F-actin. The incorporation occurred preferentially in the nucleus and in the perinuclear region of plant cells whereas part of plant microfilaments, mostly in the periphery of cytoplasm, did not incorporate mammalian actin. Conclusions Microinjected mammalian actin is able to enter plant cell's nucleus, whereas incorporation of mammalian actin into plant F-actin occurs preferentially in the nucleus and perinuclear area.

  13. Structure of Tz = 3 / 2 , 33P Nucleus

    Lubna, Rebeka Sultana; Tripathi, Vandana; Tabor, Samuel; Tai, Pei-Laun; Bender, Peter

    2016-03-01

    The excited states of the nucleus 33P were populated by the 18O(18O, p-2n γ)33P fusion evaporation reaction at Elab = 25 MeV.Gammasphere was used along with the particle detector Microball to detect the γ emissions in coincidence with the emitted charged particles from the compound nucleus 36S. The auxiliary detector Microball was used to select the charged particle channel and to determine the exact position and the energy of the emitted proton. The purpose of finding the position and energy of proton was to determine a more precise angle between the recoil nucleus and the emitted γ which was later employed to get a better Doppler correction. Along with the selection of the proton channel, the γ- γ coincidence technique helped to isolate 33P from the other phosphorus isotopes and also reduced the contaminations from the dominant pure neutron channels. A number of transitions and states was identified that were not observed before. The 4 π arrangement of Gammasphere offered an excellent opportunity to measure the angular distribution of the electromagnetic emissions leading to the assignment of the spins for most of the new states. The experimental observations were compared to the shell model calculation using Work supported by the U.S. National Science Foundation under Grant No. 1401574.

  14. Azimuthal distributions of final-state particles and fragments and transverse structure of emission source in high-energy nucleus-nucleus collisions

    Liu Fu-Hu; Ma Yin-Qun; Duan Mai-Ying

    2005-01-01

    The azimuthal distributions of final-state particles and fragments produced in high-energy nucleus-nucleus collisions are described by a modified multisource ideal gas model which contains the expansions and movements of the emission sources. The transverse structures of the sources are given in the transverse plane by momentum components px and py, and described by parameters in the model. The results of the azimuthal distributions, calculated by the Monte Carlo method, are in good agreement with the experimental data in nucleus-nucleus collisions at high energies.

  15. Comparison of J/ψ-suppression in photon, hadron and nucleus-nucleus collisions: Where is the quark-gluon plasma?

    The data of J/ψ-production cross sections from photon, hadron and nucleus-nucleus collisions are plotted against the length of the canti c final state trajectory in nuclear matter. A value for the absorption cross section per nucleon of σabsψN=(6.2±0.3) mb is deduced from the baryon and photon induced reactions and σabsψN=(6.9±1.0) mb from the nucleus-nucleus collisions. The equality of cross sections implies that additional suppression effects from a quark-gluon plasma are not visible. (orig.)

  16. Production of Kaon and $\\Lambda$ in nucleus-nucleus collisions at ultra-relativistic energy from a blast wave model

    Zhang, Song; Chen, Jin-Hui; Zhong, Chen

    2014-01-01

    The particle production of Kaon and $\\Lambda$ are studied in nucleus-nucleus collisions at relativistic energy based on a chemical equilibrium blast-wave model. The transverse momentum spectra of Kaon and $\\Lambda$ at the kinetic freeze-out stage from our model are in good agreement with the experimental results. The kinetic freeze-out parameters of temperature ($T_{kin}$) and radial flow parameter $\\rho_{0}$ are presented for the FOPI, RHIC and LHC energies. And the resonance decay effect is also discussed. The systematic study for beam energy dependence of the strangeness particle production will help us to better understand the properties of the matter created in heavy-ion collisions at the kinetic freeze-out stage.

  17. Charged pion coherent production in nucleus-nucleus collisions at incident energies between 86 and 330 MeV/nucleon

    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

  18. Hadron multiplicities and chemical freeze-out conditions in proton-proton and nucleus-nucleus collisions

    Vovchenko, V.; Begun, V. V.; Gorenstein, M. I.

    2016-06-01

    New results of the NA61/SHINE Collaboration at the CERN SPS on mean hadron multiplicities in proton-proton (p+p) interactions are analyzed within the transport models and the hadron resonance gas (HRG) statistical model. The chemical freeze-out parameters in p+p interactions and central Pb+Pb (or Au+Au) collisions are found and compared with each other in the range of the center-of-mass energy of the nucleon pair √{sN N}=3.2 -17.3 GeV. The canonical ensemble formulation of the HRG model is used to describe mean hadron multiplicities in p+p interactions and the grand canonical ensemble in central Pb+Pb and Au+Au collisions. The chemical freeze-out temperatures in p+p interactions are found to be larger than the corresponding temperatures in central nucleus-nucleus collisions.

  19. Theoretical and experimental aspects of the multiple fragmentation reactions in the nucleus-nucleus collisions at intermediate energies

    The multiple fragmentation phenemenon is observed in the nucleus-nucleus collisions, at intermediate energies. The experimental and theoretical investigation of the reaction mechanism, is performed. The process is theoretically described, by applying dynamical and fragmentation models. The dynamical phase simulation is carried out by means of the Landau-Vlasov calculations, which are performed up to the obtention of a low density system. A statistical fragmentation model is applied. The results show that a multiple fragmentation must occur at intermediate energies; and that the reaction threshold energy and properties are bound to the nuclear matter state equation. The evolution mechanisms of the Argon-on-Aluminum system experiment, from 25 to 85 MeV per nucleon, are analyzed. It allows both the collisions classification as a function of their impact parameter and the selection of the central collisions. The existence of the multiple fragmentation phenomenom is pointed out

  20. 61. International conference NUCLEUS-2011 on problems of nuclear spectroscopy and structure of atomic nucleus. Book of abstracts

    The program of the 61th International conference NUCLEUS-2011 covers almost all actual problems of nuclear physics. The recent results of theoretical and experimental investigations of nuclear structure as well as nuclear reactions are presented. The fundamental problems of nuclear physics are discussed. The current achievements in the field of nuclear instrumentation and experimental techniques are considered. The considerable attention is given to modern nuclear databases as scientific research tools

  1. Characterization of solid phases and study of transformation kinetics in m-chlorofluorobenzene by 35Cl nuclear quadrupole resonance.

    Pérez, Silvina; Wolfenson, Alberto

    2012-02-01

    Polymorphism is of widespread occurrence in the world of molecular crystals. In this work we present experimental results showing the existence of four solid phases in m-chlorofluorobenzene. A glass structure is achieved by quenching the liquid phase at 77 K. This glassy state crystallizes in a disordered phase at T~143 K, which in turn transforms to the high-temperature stable phase (phase I) at T~153 K. Depending on the thermal history of the sample, a different ordered phase (phase III) can be obtained. The disorder is attributed to a molecular orientational disorder. There is no evidence of molecular reorientation in any phase. A study of the disorder-order phase transformation kinetics, using nuclear quadrupole resonance, is presented. The results are analyzed following Cahn's theory. Nucleation seems to take place at grain boundaries. Growth rates for different temperatures have been determined. PMID:22209621

  2. The Cl-35/Cl-37 isotopic ratio in dense molecular clouds : HIFI observations of hydrogen chloride towards W3 A

    Cernicharo, J.; Goicoechea, J. R.; Daniel, F.; Agundez, M.; Caux, E.; de Graauw, T.; De Jonge, A.; Kester, D.; Leduc, H. G.; Steinmetz, E.; Stutzki, J.; Ward, J. S.

    2010-01-01

    We report on the detection with the HIFI instrument on board the Herschel satellite of the two hydrogen chloride isotopologues, (HCl)-Cl-35 and (HCl)-Cl-37, towards the massive star-forming region W3 A. The J = 1-0 line of both species was observed with receiver 1b of the HIFI instrument at similar

  3. Light and variable 37Cl/35Cl ratios in rocks from Gale Crater, Mars: Possible signature of perchlorate

    Farley, K. A.; Martin, P.; Archer, P. D.; Atreya, S. K.; Conrad, P. G.; Eigenbrode, J. L.; Fairén, A. G.; Franz, H. B.; Freissinet, C.; Glavin, D. P.; Mahaffy, P. R.; Malespin, C.; Ming, D. W.; Navarro-Gonzalez, R.; Sutter, B.

    2016-03-01

    Cl isotope ratios measured on HCl thermally evolved from as-yet-unknown phases in sedimentary rocks and sand in Gale Crater provide unexpected insights to the Martian surficial Cl cycle. The seven samples yield δ37Cl values ranging from - 1 ± 25 ‰ to - 51 ± 5 ‰. Five analyses from two samples of the Sheepbed mudstone (Yellowknife Bay study area) are analytically indistinguishable with a mean δ37Cl of - 11 ± 7 ‰ (1 σ). In contrast, four mudstones/sandstones from the Kimberley and Pahrump study areas also yielded indistinguishable ratios, but with a mean δ37Cl of - 43 ± 6 ‰. The Rocknest sand deposit gave a highly uncertain δ37Cl value of - 7 ± 44 ‰. These light and highly variable δ37Cl values are unique among known solar system materials. Two endmember models are offered to account for these observations, and in both, perchlorate, with its extreme ability to fractionate Cl isotopes, is critical. In the first model, SAM is detecting HCl from an oxychlorine compound (e.g., perchlorate) produced from volcanic gas emissions by atmospheric chemical reactions. Similar reactions in Earth's atmosphere may be responsible for the isotopically lightest known Cl outside of this study, in perchlorate from the Atacama Desert. Some of the Gale Crater δ37Cl values are more negative than those in Atacama perchlorate, but because reaction mechanisms and associated fractionation factors are unknown, it is impossible to assess whether this difference is prohibitive. If the negative δ37Cl signal is produced in this fashion, the isotopic variability among samples could arise either from variations in the relative size of the reactant chloride and product perchlorate reservoirs, or from variations in the fraction of perchlorate reduced back to chloride after deposition. Such reduction strongly enriches 37Cl in the residual perchlorate. Perchlorate reduction alone offers an alternative endmember model that can explain the observed data if SAM measured HCl derived from chloride. In this model isotopically normal perchlorate produced by an unspecified mechanism is reduced to chloride. Depending on the relative size of the reduced reservoir, the integrated product chloride can vary in isotopic composition from - 70 ‰ in the first increment all the way to the starting composition if the perchlorate is fully reduced. Thus, variable degrees of perchlorate reduction can produce chloride with the appropriate δ37Cl range. Combination of the two endmember models, in which the perchlorate subject to post-deposition reduction is isotopically negative from atmospheric reactions, is also possible. Determination of the phase hosting the Cl measured by SAM, an oxychlorine compound or chloride, is critical for selecting between these models, and for developing implications of the results for the Mars surficial Cl cycle. At present it is not possible to conclusively establish which phase is responsible (possibly both), but limited evidence favors the conclusion that the measured Cl derives mostly from an oxychlorine compound.

  4. Nuclear temperature anomaly in 35Cl+24Mg reaction at Ec.m.=105 MeV

    It was found earlier from studies on A∼100 mass region at (4-8) MeV/A bombarding energy that the temperatures obtained from the slopes of the spectra of the heavier evaporation fragments (such as α, Li, B, C etc.) were significantly higher than the expectations from statistical model calculations. We have now extended this investigation to lower mass region (A ∼60)

  5. The role of the nucleus basalis of Meynert and reticular thalamic nucleus in pathogenesis of genetically determined absence epilepsy in rats : A lesion study

    Berdiev, R. K.; Chepurnov, S. A.; Veening, J. G.; Chepurnova, N. E.; van Luiftelaar, G.

    2007-01-01

    The role of cholinergic nucleus basalis (of Meynert) and the reticular thalamic nucleus in mechanisms of the generation spontaneous spike-and-wave discharges (SWDs) was investigated in the WAG/Rij rat model of absence epilepsy. Selective lesions were affected by local unilateral intraparenchymal inf

  6. Stereotactic localization and visualization of the subthalamic nucleus

    SHEN Wei-gao; WANG Hai-yang; LIN Zhi-guo; SHEN Hong; CHEN Xiao-guang; FU Yi-li; GAO Wen-peng

    2009-01-01

    Background The subthalamic nucleus (STN) is widely recognized as one of the most important and commonly targeted nuclei in stereotactic and functional neurosurgery. The success of STN surgery depends on accuracy in target determination. Construction of a digitalized atlas of STN based on stereotactic MRI will play an instrumental role in the accuracy of anatomical localization. The aim of this study was to investigate the three-dimensional (3D) target location of STN in stereotactic space and construct a digitalized atlas of STN to accomplish the visualization of the STN on stereotactic MRI, thus providing clinical guidance on the precise anatomical localization of STN.Methods One hundred and twenty healthy people volunteered to be scanned by 1.5 Tesla MRI scanning with 1-mm-thick slice in the standard stereotactic space between 2005 and 2006. One adult male was selected for 3D reconstruction of STN. The precess of 3D reconstruction included identification, manual segmentation, extraction,conservation and reconstruction.Results There was a significant correlation between the coordinates and age (P <0.05). The volume of left STN was significantly larger than the right STN, and there was a significant negative correlation between volume and age (P <0.05).The surface of the STN nucleus after 3D reconstruction appeared smooth, natural and realistic. The morphological feature of STN on the individual brain could be visualized directly in 3D. The 3D reconstructed STN could be rotated,zoomed and displayed at any direction in the stereotactic space. The anteroposterior diameter of the STN nucleus was longer than the vertical and transverse diameters in 3D space. The 3D reconstruction of STN manifested typical structure of the "dual lens".Conclusions The visualization of individual brain atlas based on stereotactic MRI is feasible. However, software for automated segmentation, extraction and registration of MR images need to be further developed.

  7. Active galactic nucleus feedback in clusters of galaxies.

    Blanton, Elizabeth L; Clarke, T E; Sarazin, Craig L; Randall, Scott W; McNamara, Brian R

    2010-04-20

    Observations made during the last ten years with the Chandra X-ray Observatory have shed much light on the cooling gas in the centers of clusters of galaxies and the role of active galactic nucleus (AGN) heating. Cooling of the hot intracluster medium in cluster centers can feed the supermassive black holes found in the nuclei of the dominant cluster galaxies leading to AGN outbursts which can reheat the gas, suppressing cooling and large amounts of star formation. AGN heating can come in the form of shocks, buoyantly rising bubbles that have been inflated by radio lobes, and the dissipation of sound waves. PMID:20351250

  8. W-Z interference in ν-nucleus scattering

    The creation of muon pairs by (anti)neutrinos in the Coulomb field of the nucleus provides a direct test of the interference between the intermediate-vector-boson amplitudes, as predicted by the weak-interaction theory. This paper summarizes the main features of the above process and discusses the feasibility of measuring the W-Z interference by searching for recoilless dimuon events using fine-grained counter neutrino detectors. The result from an earlier experiment which searched for this process is discussed in the context of the present calculation

  9. W-Z interference in. nu. -nucleus scattering

    Belusevic, R.; Smith, J.

    1988-05-01

    The creation of muon pairs by (anti)neutrinos in the Coulomb field of the nucleus provides a direct test of the interference between the intermediate-vector-boson amplitudes, as predicted by the weak-interaction theory. This paper summarizes the main features of the above process and discusses the feasibility of measuring the W-Z interference by searching for recoilless dimuon events using fine-grained counter neutrino detectors. The result from an earlier experiment which searched for this process is discussed in the context of the present calculation.

  10. W-Z interference in ν-nucleus scattering

    Belusevic, R.; Smith, J.

    1988-05-01

    The creation of muon pairs by (anti)neutrinos in the Coulomb field of the nucleus provides a direct test of the interference between the intermediate-vector-boson amplitudes, as predicted by the weak-interaction theory. This paper summarizes the main features of the above process and discusses the feasibility of measuring the W-Z interference by searching for recoilless dimuon events using fine-grained counter neutrino detectors. The result from an earlier experiment which searched for this process is discussed in the context of the present calculation.

  11. Electric multipole response of the halo nucleus $^6$He

    Singh, Jagjit; Vitturi, A; Chatterjee, R

    2016-01-01

    The role of different continuum components in the weakly-bound nucleus $^6$He is studied by coupling unbound spd-waves of $^5$He by means of simple pairing contact-delta interaction. The results of our previous investigations in a model space containing only p-waves, showed the collective nature of the ground state and allowed the calculation of the electric quadrupole transitions. We extend this simple model by including also sd-continuum neutron states and we investigate the electric monopole, dipole and octupole response of the system for transitions to the continuum, discussing the contribution of different configurations.

  12. Dust photometry in the near nucleus region of comet Halley

    The dust-jet radial brightness has been analyzed along jet cores on images taken by the tv experiment aboard VEGA 2 spacecraft, during the close encounter with comet Halley in 1986 March. Applying the RFIT code for fitting the data obtained it was shown that there is a breakpoint in the radial brightness distribution which occurs at about 40 km above the surface. These results are interpreted as consequences of the heat shock induced disintegration of dust particles as they are ejected into the near-nucleus environment. (R.P.) 22 refs.; 4 tabs

  13. Recent developments in the understanding of pion-nucleus scattering

    A development of the theory of pion-nucleus scattering is given in a field theoretical framework. The theory is designed to describe pion elastic scattering and single- and double-charge exchange to isobaric analog states. An analysis of recent data at low and resonance energies is made. Strong modifications to the simple picture of the scattering as a succession of free pion-nucleon interactions are required in order to understand the data. The extent to which the experiment is understood in terms of microscopic theory is indicated. 71 references

  14. Arachnophobia alleviated by subthalamic nucleus stimulation for Parkinson's disease.

    Allert, Niels; Gippert, Sabrina M; Sajonz, Bastian E A; Nelles, Christoph; Bewernick, Bettina; Schlaepfer, Thomas E; Coenen, Volker A

    2016-06-01

    We report on a Parkinson patient with motor fluctuations and dyskinesias in whom deep brain stimulation (DBS) of the subthalamic nucleus (STN) not only improved motor symptoms but also pre-existing arachnophobia. Arachnophobia had been unchanged by the course of Parkinson's disease but rapidly improved with STN-DBS. Both, motor effects and the improvement of arachnophobia were stable during 2 years follow-up. To our knowledge this is the first report on STN stimulation effects on a specific phobia. PMID:27198699

  15. Collective Band Structures in Neutron-Rich 108Mo Nucleus

    DING Huai-Bo; WANG Jian-Guo; XU Qiang; ZHU Sheng-Jiang; J. H. Hamilton; A. V. Ramayya; J. K. Hwang; Y. X. Luo; J. O. Rasmussen; I. Y. Lee; CHE Xing-Lai

    2007-01-01

    High spin states in the neutron-rich 108Mo nucleus are studied by measuring prompt γ-rays following the spontaneous fission of 252Cf with a Gammasphere detector array. The ground-state band is confirmed, and the one-phonon γ-vibrational band is updated with spin up to 12 h. A new collective band with the band head level at 1422.4 keV is suggested as a two-phonon γ-vibrational band. Another new band is proposed as a two-quasi-proton excitation band. Systematic characteristics of the collective bands are discussed.

  16. On the symmetries of the 12C nucleus

    Cseh, J

    2016-01-01

    The consequences of some symmetries of the three-alpha system are discussed. In particular, the recent description of the low-energy spectrum of the 12C nucleus in terms of the Algebraic Cluster Model (ACM) is compared to that of the Semimicroscopic Algebraic Cluster Model (SACM). The previous one applies interactions of a D3h geometric symmetry [1], while the latter one has a U(3) multichannel dynamical symmetry, that connects the shell and cluster pictures. The available data is in line with both descriptions.

  17. Nanoparticle-Based Immunocytochemistry Reveals Microarchitecture of the Cell Nucleus

    Hozák, Pavel

    Kyoto : International Federation of Societies for Histochemistry and Cytochemistry, Japan Society of Histochemistry, 2012. [14th International Congress of Histochemistry and Cytochemistry. Kyoto (JP), 26.08.2012-29.08.2012] R&D Projects: GA ČR GAP305/11/2232; GA MŠk LC545; GA MŠk(CZ) LC06063; GA MPO(CZ) FRTI3588 Institutional research plan: CEZ:AV0Z50520514 Institutional support: RVO:68378050 Keywords : PIP2 * NMI * cell nucleus Subject RIV: EB - Genetics ; Molecular Biology

  18. Level density of radioactive doubly-magic nucleus 56Ni

    In this work the single particle energies are obtained by diagonalising the Nilsson Hamiltonian in the cylindrical basis and are generated up to N =11 shells for the isotopes of Ni from A = 48-70, emphasizing the three magic nuclei viz, 48Ni, 56Ni and 68Ni. The statistical quantities like excitation energy, level density parameter and nuclear level density which play the important roles in the nuclear structure and nuclear reactions can be calculated theoretically by means of the Statistical or Partition function method. Hence the statistical model approach is followed to probe the dynamical properties of the nucleus in the microscopic level

  19. Nanoparticle-based immunocytochemistry reveals microarchitecture of the cell nucleus

    Hozák, Pavel

    Mérida : CIASEM, AMM, 2011. ---. [Inter-American Congress on Microscopy /11./. 25.09.2011-29.09.2011, Mérida] R&D Projects: GA ČR GAP305/11/2232; GA ČR(CZ) GD204/09/H084; GA MŠk LC545; GA MŠk(CZ) LC06063; GA AV ČR KAN200520704 Institutional research plan: CEZ:AV0Z50520514 Keywords : nanoparticles * immunogold detection * histochemistry * cell nucleus Subject RIV: EB - Genetics ; Molecular Biology

  20. Mineralogy and Petrology of COMET WILD2 Nucleus Samples

    Zolensky, Michael; Bland, Phil; Bradley, John; Brearley, Adrian; Brennan, Sean; Bridges, John; Brownlee, Donald; Butterworth, Anna; Dai, Zurong; Ebel, Denton

    2006-01-01

    The sample return capsule of the Stardust spacecraft will be recovered in northern Utah on January 15, 2006, and under nominal conditions it will be delivered to the new Stardust Curation Laboratory at the Johnson Space Center two days later. Within the first week we plan to begin the harvesting of aerogel cells, and the comet nucleus samples they contain for detailed analysis. By the time of the LPSC meeting we will have been analyzing selected removed grains for more than one month. This presentation will present the first results from the mineralogical and petrological analyses that will have been performed.

  1. Isospin symmetry violation, meson production and -nucleus interaction studies

    B J Roy; V Jha; A Chatterje; H Machner; GEM Collaboration

    2006-05-01

    We have studied isospin symmetry violation in nuclear reactions by measuring simultaneously the cross-section of the following two reactions + → 3H + and + → 3He 0. 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 and lambda-proton final state interaction studies. The experimental details and results obtained so far are presented here.

  2. Nanoparticle-based immunocytochemistry reveals microarchitecture of the cell nucleus

    Hozák, Pavel

    Istanbul: Turkish Society for Electron Microscopy, 2011. ---. [National Electron Microscopy Congress /20./. 25.10.2011-28.10.2011, Kemer] R&D Projects: GA ČR GAP305/11/2232; GA ČR(CZ) GD204/09/H084; GA MŠk LC545; GA MŠk(CZ) LC06063; GA MŠk 2B06063; GA AV ČR KAN200520704 Institutional research plan: CEZ:AV0Z50520514 Keywords : nanoparticles * immunogold detection * histochemistry * cell nucleus Subject RIV: EB - Genetics ; Molecular Biology

  3. Natural orbital description of the halo nucleus 6He

    Constantinou, Ch; Vary, J P; Maris, P

    2016-01-01

    Ab initio calculations of nuclei face the challenge of simultaneously describing strong short-range internucleon correlations and the long-range properties of weakly-bound halo nucleons. Natural orbitals, which diagonalize the one-body density matrix, provide a basis which is better matched to the physical structure of the many-body wave function. We demonstrate that the use of natural orbitals significantly improves convergence for ab initio no-core configuration interaction calculations of the neutron halo nucleus 6He, relative to the traditional oscillator basis.

  4. Three-dimensional organization of the human interphase nucleus

    Knoch, Tobias; Wachsmuth, Malte; Waldeck, Waldemar; Langowski, Jörg

    2002-01-01

    textabstractTo approach the three-dimensional organization of the human cell nucleus, the structural-, scaling- and dynamic properties of interphase chromosomes and cell nuclei were simulated with Monte Carlo and Brownian Dynamics methods. The 30 nm chromatin fibre was folded according to the Multi-Loop-Subcompartment (MLS) model, in which ~100 kbp loops form rosettes, connected by a linker, and the Random-Walk/Giant-Loop (RW/GL) topology, in which 1-5 Mbp loops are attached to a flexible bac...

  5. Coulomb excitation of the N=50 nucleus 80Zn

    van de Walle, Jarno; Aksouh, Farouk; Ames, F.; Behrens, Thomas; Bildstein, V.; Blazhev, A.; Cederkall, Joakim; Clement, Emmanuel; Cocolios, Thomas Elias; Davinson, T.; Delahaye, Pierre; Eberth, J.; Ekstrom, Andreas; Fedorov, Dima V; Fedosseev, Valentin N.

    2008-01-01

    Neutron rich Zinc isotopes, including the N = 50 nucleus 80Zn, were produced and post-accelerated at the Radioactive Ion Beam (RIB) facility REX-ISOLDE (CERN). Low-energy Coulomb excitation was induced on these isotopes after post-acceleration, yielding B(E2) strengths to the first excited 2+ states. For the first time, an excited state in 80Zn was observed and the 21+ state in 78Zn was established. The measured B(E2,21+->01+) values are compared to two sets of large scale shell model calcula...

  6. High-spin structure of 188Pt nucleus

    The possibility of a new type of shape phase transition occurring along its yrast cascade has already been predicted in this nucleus. Similar type of shape phase transition, occurring along the yrast line between states of prolate and oblate shape, was predicted in 190W, which is yet to be studied in detail in experiments due to its neutron-richness. Following such theoretical expectation and present experimental limitation vis-a-vis 190W, a detailed spectroscopic investigation on the high-spin level structure of 188Pt is imperative, which will, in turn, also be useful to extrapolate the explanations on shape phase transition to 190W in greater detail

  7. Leksikalnata baza danni Praleks - struktura i obrabotka na zaglavnite edinici

    Světlá, Jindra; Rangelova, Albena

    Sofija: Avangard Prima, 2011 - (Blagoeva, D.; Kolkovska, S.), s. 61-76 ISBN 978-954-323-923-8 Institutional research plan: CEZ:AV0Z90610521 Keywords : lexical database * index * monolingual lexicography * methodology Subject RIV: AI - Linguistics

  8. Netradiční polyolefiny: Struktura, vlastnosti a perspektivy

    Chvátalová, L.; Výchopňová, J.; Čermák, R.; Raab, Miroslav

    2007-01-01

    Roč. 44, 7-8 (2007), s. 202-208. ISSN 0322-7340 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyolefins * hierarchical structure * poly-1-butene Subject RIV: CD - Macromolecular Chemistry

  9. RATNI UINCI NA PROMJENE DEMOGRAFSKIH STRUKTURA U HRVATSKOJ

    GELO, Jakov

    1999-01-01

    Procjenjujući kretanje ukupnog stanovništva Hrvatske nakon popisa stanovništva 1991., a do godine 1998. uočili smo više nepovoljnih (i nepoželjnih) procesa u našem stanovništvu, nastalih u proteklih osam godina. U ovome radu analizirali smo tri, po našem mišljenju, najmanje poželjna procesa s aspekta budućeg razvitka hrvatskog pučanstva. Prvo je riječ o opadanju broja ukupnog stanovništva Hrvatske. Godine 1998. bilo je 6,5 posto stanovnika manje nego godine 1991. Drugi ne...

  10. Strigolaktony - Struktura a funkce v rostlinách

    Dvořáková, Marcela; Vaněk, Tomáš

    2015-01-01

    Roč. 109, č. 10 (2015), s. 762-769. ISSN 0009-2770 R&D Projects: GA MŠk LD14127 Institutional support: RVO:61389030 Keywords : strigolactones * fytohormones * arbuscular mycorrhizal fungi Subject RIV: CC - Organic Chemistry Impact factor: 0.272, year: 2014 http://www.chemicke-listy.cz/docs/full/2015_10_762-769.pdf

  11. Struktura, intencionalita, normativita a jazykové konvence

    Koťátko, Petr

    2014-01-01

    Roč. 36, Suppl. (2014), s. 33-49. ISSN 1210-0250 Institutional support: RVO:67985955 Keywords : meaning * communicative intentions * linguistic conventions * compositionality of language Subject RIV: AA - Philosophy ; Religion

  12. JIHLAVA - POLOHA, STRUKTURA, INFRASTRUKTURA A OBRAZ MĚSTA

    KREMLÁČKOVÁ, Michaela

    2011-01-01

    This diploma thesis is a summary of urban geographic and other observations about the city of Jihlava ? for example of specific location of the city, historical development, physical geographic and social geographic characteristics and above all space structure of the city. By analysis of social geographic charasteristics I focused on territorial administrative classification of the city, on information about inhabitants and areas of production, transport and services. The central point devot...

  13. Archeologiczna struktura zbiorów ceramiki z osad neolitycznych

    Kukawka, Stanisław

    2005-01-01

    The article is intended to address an essence of pottery assemblages from Neolithic settlements. Three aspects have been analysed: relationships between complete vessels and fragments resulted from their breakage; relationship between composition of pottery vessels used at any given moment and composition of deposited ceramics; and relationship between deposited pottery and its excavated fraction. It is argued that pottery assemblages excavated and analysed by archaeologists are r...

  14. Partition of cross sections in asymmetric nucleus-nucleus reactions and the origin of fast alpha particles

    To investigate the mechanism of asymmetric nucleus-nucleus reactions from the Coulomb barrier to intermediate energies the 14N + 159Tb reaction was studied at five bombarding energies between 8 and 23 MeV/u via particle-particle correlations (at selected energies) and particle KX-ray coincidences to identify the specific reaction channels. With the KX-ray method partial cross sections for projectile-like fragments (PLF) as a function of the atomic number (Z/sub res/) of the residual nucleus can be determined. The charge balance yields the ''missing charge'' dZ = Z/sub proj/ + Z/sub targ/ - Z/sub PLF/ - Z/sub TLF/ that indicates whether, in addition to the PLF, other charged particles are emitted. A large fraction of the inclusive cross sections is found to originate from such channels with two or more fragments in the exit channel, and this fraction increases as the PLF is further removed in mass from the incident projectile, and with increasing bombarding energy. From the particle-particle correlation studies it is found that sequential decays of PLF's are dominant. ''Non-sequential'' processes, if present, are associated with inelastic reactions involving excitations of both projectile and target. The bulk of the large alpha-particle cross section at small angles is found to be associated with channels in which, in addition to the alpha particle, only nucleons and other alpha particles are emitted. From γ-ray multiplicity measurements and from the broad distribution of the strength with Z/sub res/ it is concluded that these alpha particles originate from inelastic (damped) processes. 27 refs., 10 figs

  15. Gluon production from non-abelian Weizsäcker-Williams fields in nucleus-nucleus collisions

    Kovner, A; Weigert, H; Kovner, Alex; McLerran, Larry; Weigert, Heribert

    1995-01-01

    We consider the collisions of large nuclei using the theory of McLerran and Venugopalan. The two nuclei are ultra-relativistic and sources of non-abelian Weizs\\"acker-Williams fields. These sources are in the end averaged over all color orientations locally with a Gaussian weight. We show that there is a solution of the equations of motion for the two nucleus scattering problem where the fields are time and rapidity independent before the collision. After the collision the solution depends on proper time, but is independent of rapidity. We show how to extract the produced gluons from the classical evolution of the fields.

  16. Question of η- and K−- Nucleus Bound States

    Interaction of the η-meson and that of the K−-meson with nucleons is of special interest because both of them are strongly attractive near threshold. This raises the strong possibility that we may find in nature the bound η- and K−-nuclear (quasi) bound states. This led to experimental programs to hunt for the existence of these states and theoretical studies to keep pace with them. The efforts had positive results. The η-meson studies had been there for several years by now, while those with the K−-meson had been relatively recent. The talk gives a brief critical overview of the η-nuclear interaction studies, especially in context with the η-mesic state explorations. For the K−-meson we give a brief summary of the efforts in understanding the basic K−-nucleon interaction and theoretical explorations for the existence of K−-nucleus bound states. We critically examine the FINUDA measurements as a signal for the existence of the K−-nucleus bound states, especially in context with the contribution of the single nucleon knock-out final state interaction in the (K−, pΛ) reaction.

  17. Monte Carlo Simulation for Statistical Decay of Compound Nucleus

    Chadwick M.B.

    2012-02-01

    Full Text Available We perform Monte Carlo simulations for neutron and γ-ray emissions from a compound nucleus based on the Hauser-Feshbach statistical theory. This Monte Carlo Hauser-Feshbach (MCHF method calculation, which gives us correlated information between emitted particles and γ-rays. It will be a powerful tool in many applications, as nuclear reactions can be probed in a more microscopic way. We have been developing the MCHF code, CGM, which solves the Hauser-Feshbach theory with the Monte Carlo method. The code includes all the standard models that used in a standard Hauser-Feshbach code, namely the particle transmission generator, the level density module, interface to the discrete level database, and so on. CGM can emit multiple neutrons, as long as the excitation energy of the compound nucleus is larger than the neutron separation energy. The γ-ray competition is always included at each compound decay stage, and the angular momentum and parity are conserved. Some calculations for a fission fragment 140Xe are shown as examples of the MCHF method, and the correlation between the neutron and γ-ray is discussed.

  18. Lesions of nucleus tractus solitarii globally impair cerebrovascular autoregulation

    The authors studied the effects of acute bilateral electrolytic lesions of the nucleus tractus solitarii (NTS) on regional cerebral blood flow (rCBF) and its autoregulation in rats anesthetized, paralyzed, and artificially ventilated. rCBF or regional cerebral glucose utilization (rCGU) was measured 30 min after NTS lesions, by the 14C-iodoantipyrine technique or 2-deoxyglucose method, respectively. Cerebrovascular autoregulation was assessed in groups of 4-5 rats at three levels of arterial pressure (AP):90, 125, and 140 mmHg. AP was lowered by hemorrhage or elevated by intravenous infusion of phenylephrine. NTS lesions did not alter rCBF at 125 mmHg but resulted in loss of autoregulation. In contrast, lesions of the cuneate nucleus or transection of the baroreceptor afferents did not alter autoregulation. NTS lesions did not affect the reactivity of the cerebrovascular bed to hypercarbia or hypocarbia nor the rCGU in any brain regions. They conclude that lesions of the NTS impair cerebrovascular autoregulation. The effect is not due to changes in metabolism, nonspecific effects of the lesions, vasoparalysis, or interruption of the baroreceptor reflex arch. Neural pathways originating in or passing through the NTS can regulate the cerebrovascular autoregulation of the entire brain

  19. Pion-nucleus scattering at around the DELTA (1232) resonance

    Ahmed, H S; Rahman, M A; Rahman, S N

    2003-01-01

    The pion-nucleus scattering around 200 MeV and just above 1200 MeV is dominated by strong, broad DELTA (3,3) and weak resonances in the pi sup+-N interaction. The interaction to a first approximation can be described as diffraction process. Since it is well known that the strength of the pi sup + N and pi sup - N interactions are quite different from each other at the resonances, the analyses of differential cross section for pi sup + N and pi sup - N elastic scattering data in the region of low-lying pion-nucleus resonances will be a good test of different strengths. In the present work we analyze pions scattering from nuclei sup 9 Be, sup 2 sup 8 Si, sup 5 sup 8 Ni, sup 8 sup 9 Y and sup 2 sup 0 sup 8 Pb at incident pion energies between 50 and 291 MeV within the framework of the three parameter version of the Strong Absorption Model of Frahn and Venter. All the oscillations in the elastic scattering experimental data and for the experimental angular distribution leading to 2 sup + and 3 sup - collective st...

  20. Monte Carlo simulation for statistical decay of compound nucleus

    We perform Monte Carlo simulations for particle and γ-ray emissions from a compound nucleus based on the Hauser-Feshbach statistical theory; the Monte Carlo Hauser-Feshbach (MCHF) method. The MCHF calculation, which gives us correlated information between emitted particles and γ-rays, will be a powerful tool in many applications, because we are able to probe nuclear reactions in more microscopic way. For example, the MCHF code can be used as an event generator in a radiation transport code. Having the correlated neutron and γ-ray emission process in the transport calculations, energy conservation is satisfied automatically event-by-event. In addition, the correlations amongst particles and γ-ray can be a signature of a particular nuclear reaction occurred in a nuclear system. We have been developing the MCHF code, CGM, which solves the Hauser-Feshbach equation with the Monte Carlo method. The code includes all the common models that emerge in a standard Hauser-Feshbach code, namely the particle transmission generator, the level density module, interface to the discrete level database, and so on. The code allows to emit multiple neutrons, as long as the excitation energy of the compound nucleus is larger than the neutron separation energy. The γ-ray competition is always included at each compound decay stage, and the angular momentum conservation holds too. In this paper, we discuss our technique to calculate the particle and γ-ray correlations in the statistical model framework, and some simulation examples are shown

  1. Structure of the nucleus of 1928+738

    Roland, J; Kun, E; Henri, G; Lambert, S; Zensus, A

    2014-01-01

    Modeling of the trajectories of VLBI components ejected by the nucleus of 1928+738 shows the VLBI jet contains three families of trajectories, i.e. VLBI components are ejected from three different origins. The fit of components C1, C6 and C8 indicates that the nucleus of 1928+738 contains two binary black hole systems. The first binary black hole system is associated with the stationary components Cg and CS and is characterized by a radius $R_{bin,1} \\approx 0.220$ mas; both black holes ejected VLBI components quasi regularly between 1990 and 2010. The second binary black hole system is not associated with stationary components and is characterized by a radius $R_{bin,2} \\approx 0.140$ mas; it ejected only three VLBI components between 1994 and 1999. The two black hole sytems are separated by $\\approx 1.35$ mas. We briefly discuss the consequences of the existence of binary black holes systems in radio quasars to make the link between radio quasars and GAIA.

  2. The development of the Nucleus Freedom Cochlear implant system.

    Patrick, James F; Busby, Peter A; Gibson, Peter J

    2006-12-01

    Cochlear Limited (Cochlear) released the fourth-generation cochlear implant system, Nucleus Freedom, in 2005. Freedom is based on 25 years of experience in cochlear implant research and development and incorporates advances in medicine, implantable materials, electronic technology, and sound coding. This article presents the development of Cochlear's implant systems, with an overview of the first 3 generations, and details of the Freedom system: the CI24RE receiver-stimulator, the Contour Advance electrode, the modular Freedom processor, the available speech coding strategies, the input processing options of Smart Sound to improve the signal before coding as electrical signals, and the programming software. Preliminary results from multicenter studies with the Freedom system are reported, demonstrating better levels of performance compared with the previous systems. The final section presents the most recent implant reliability data, with the early findings at 18 months showing improved reliability of the Freedom implant compared with the earlier Nucleus 3 System. Also reported are some of the findings of Cochlear's collaborative research programs to improve recipient outcomes. Included are studies showing the benefits from bilateral implants, electroacoustic stimulation using an ipsilateral and/or contralateral hearing aid, advanced speech coding, and streamlined speech processor programming. PMID:17172547

  3. Clinical evaluation of the Nucleus® 6 cochlear implant system: Performance improvements with SmartSound iQ

    Mauger, Stefan J.; Warren, Chris D; Knight, Michelle R; Goorevich, Michael; Nel, Esti

    2014-01-01

    Objective: This paper provides a detailed description of the Nucleus 6 system, and clinically evaluates user performance compared to the previous Nucleus 5 system in cochlear implant recipients. Additionally, it clinically evaluates a range of Nucleus 6 and Nucleus 5 programs to determine the performance benefits provided by new input processing technologies available in SmartSound iQ. Design Speech understanding tests were used to clinically validate the default Nucleus 6 program, by compari...

  4. Pilot biomechanical design of biomaterials for artificial nucleus prosthesis using 3D finite-element modeling

    Qijin Huang; Guoquan Liu; Yong Li; Jin Gao; Zhengqiu Gu; Yuanzheng Ma; Haibin Xue

    2004-01-01

    Pilot biomechanical design of biomaterials for artificial nucleus prosthesis was carried out based on the 3D finite-element method. Two 3D models of lumbar intervertebral disc respectively with a real human nucleus and with the nucleus removed were developed and validated using published experimental and clinical data. Then the models with a stainless steel nucleus prosthesis implanted and with polymer nucleus prostheses of various properties implanted were used for the 3D finite-element biomechanical analysis. All the above simulation and analysis were carried out for the L4/L5 disc under a human worst-daily compression load of 2000 N. The results show that the polymer materials with Young's modulus of elasticity E = 0.1-100 MPa and Poisson's ratio v=0.35-0.5 are suitable to produce artificial nucleus prosthesis in view of biomechanical consideration.

  5. Preliminary experience of cochlear implants for Nucleus 24 Contour%Nucleus 24 Contour人工耳蜗植入术初步体会

    郭梦和; 钱雨红; 李永贺; 张宏征

    2003-01-01

    目的报道16例Nucleus 24 Contour人工耳蜗的手术方法和初步效果.方法介绍Nucleus 24 Contour人工耳蜗手术方法、注意事项和结果,与Nucleus 24 M人工耳蜗植入后的编程调试结果(T-Level,C-Level)进行比较.结果16例病人术后4~5次编程调试后,声场测听达到20~35dB(HL),平均24.4±5.8dB,C-level.T-Level和C-Level均比Nucleuse 24 M要小,动态范围比Nucleus24M大.结论初步结果显示,Nucleus 24Contour人工耳蜗性能比Nucleus 24M型人工耳蜗有某些提高,但手术时应注意操作特点.

  6. Pedunculopontine Nucleus Gamma Band Activity-Preconscious Awareness, Waking, and REM Sleep

    Urbano, Francisco J.; D’Onofrio, Stasia M.; Brennon R Luster; Paige B Beck; Hyde, James Robert; Bisagno, Veronica; Garcia-Rill, Edgar

    2014-01-01

    The pedunculopontine nucleus (PPN) is a major component of the reticular activating system (RAS) that regulates waking and REM sleep, states of high-frequency EEG activity. Recently, we described the presence of high threshold, voltage-dependent N- and P/Q-type calcium channels in RAS nuclei that subserve gamma band oscillations in the mesopontine PPN, intralaminar parafascicular nucleus (Pf), and pontine subcoeruleus nucleus dorsalis (SubCD). Cortical gamma band activity participates in sens...

  7. Study of fragmentation of relativistic carbon nucleus in inelastic scattering with propane and tantalum nuclei

    The new experimental data on relative yields, moment and correlation characteristics of the various spectator fragments from carbon nucleus inelastically interacting with the propane and tantalum nuclei at the primary momentum of 4.24 GeV/c are presented and discussed. The dependences of cross sections and transverse momentum distributions of spectator protons, deuterons and tritons on the mass number of target and the impact parameter of nucleus-nucleus collision have been investigated

  8. The elastic π-nucleus scattering in the (3/2-3/2) resonance region

    The elastic pion-nucleus scattering in the (3/2-3/2) resonance region is analyzed. The aim of the work is threefold. Working with the Watson's multiple scattering theory, one strives for: -a better understanding of the pion-nucleus interaction in terms of elementary interaction; -a justification of the theoretical framework by using the Lee model; -a study of the sensitivity of the optical potential to the macroscopic parameters of the nucleus

  9. GABA in nucleus tractus solitarius participates in electroacupuncture modulation of cardiopulmonary bradycardia reflex

    Tjen-A-Looi, Stephanie C.; Guo, Zhi-Ling; Longhurst, John C.

    2014-01-01

    Phenylbiguanide (PBG) stimulates cardiopulmonary receptors and cardiovascular reflex responses, including decreases in blood pressure and heart rate mediated by the brain stem parasympathetic cardiac neurons in the nucleus ambiguus and nucleus tractus solitarius (NTS). Electroacupuncture (EA) at P5–6 stimulates sensory fibers in the median nerve and modulates these reflex responses. Stimulation of median nerves reverses bradycardia through action of γ-aminobutyric acid (GABA) in the nucleus a...

  10. Role of adrenomedullin in the cerebrospinal fluid-contacting nucleus in the modulation of immobilization stress.

    Wu, Yue-Hong; Song, Si-Yuan; Liu, He; Xing, Dan; Wang, Xin; Fei, Yan; Li, Guang-Ling; Zhang, Chao; Li, Ying; Zhang, Li-Cai

    2015-06-01

    The contribution of the cerebrospinal fluid-contacting nucleus (CSF-contacting nucleus) and adrenomedullin (ADM) to the developmental modulation of stressful events remains controversial. This study explored the effects of endogenous ADM in the CSF-contacting nucleus on immobilization of stress-induced physiological parameter disorders and glucocorticoid hormone releasing hormone (CRH), rat plasma corticosterone expression, and verification of such effects by artificially lowering ADM expression in the CSF-contacting nucleus by targeted ablation of the nucleus. Immunohistochemical experiments showed that ADM-like immunoreactivity and the calcitonin receptor-like receptor (CRLR) marker were localized in the CSF-contacting nucleus. After 7 continuous days of chronic immobilization stress (CIS), animals exhibited anxiety-like behavior. Also, an increase in serum corticosterone, and enhanced expression of ADM in the CSF-contacting nucleus were observed, following activation by CIS. The intracerebroventricular (i.c.v.) administration of the ADM receptor antagonist AM22-52 significantly reduced ADM in the CSF-contacting nucleus, additionally, blocked the effects of ADM, meaning the expression of CRH in the hypothalamic paraventricular nucleus (Pa) and serum corticosterone level were increased, and the physiological parameters of the rats became correspondingly deteriorated. Additionally, the i.c.v. administration of cholera toxin subunit B-saporin (CB-SAP), a cytotoxin coupled to a cholera toxin subunit, completely eliminated the CSF-contacting nucleus, worsening the reaction of the body to CIS. The collective results demonstrated that ADM acted as a stress-related peptide in the CSF-contacting nucleus, and its lower expression and blocked effects in the nucleus contributed to the deterioration of stress-induced physiologic parameter disorders as well as the excessive expressions of stress-related hormones which were part of the hypothalamic-pituitary-adrenal (HPA) axis

  11. Colour of the nucleus as a marker of nuclear hardness, diameter and central thickness

    Gullapalli Vamsi; Murthy Praveen; Murthy K

    1995-01-01

    Hundred and thirty patients, aged above 40 years, with senile cataract were examined. Age and colour were selected as the probable preoperative indicators of nuclear hardness. The lens material collected after manual extracapsular extraction was washed and the nucleus isolated. The diameter and central thickness of the nucleus were measured; the mean diameter and mean central thickness were 7.13 mm ± 0.76 and 3.05 mm ± 0.48, respectively. The hardness of the nucleus was measured...

  12. Amygdaloid and basal forebrain direct connections with the nucleus of the solitary tract and the dorsal motor nucleus

    Although the amygdala complex has long been known to exert a profound influence on cardiovascular activity, the neuronal and connectional substrate mediating these influences remains unclear. This paper describes a direct amygdaloid projection to medullary sensory and motor structures involved in cardiovascular regulation, the nucleus of the solitary tract (NTS) and the dorsal motor nucleus (DVN), by the use of autoradiographic anterograde transport and retrograde horseradish peroxidase (HRP) techniques in rabbits. Since all of these structures are highly heterogeneous structurally and functionally, details of the specific areas of the neuronal origin and efferent distribution of the projection were examined in relation to these features and with reference to a cytoarchitecture description of the relevant forebrain regions in the rabbit. The existence of such an extensive projection system connecting these specific regions found in these studies is significant evidence in support to its potential for participation in the amygdaloid expression of cardiovascular influences and has important implications for the cellular analysis of the functional role of these influences

  13. Drell-Yan Cross Section and $J/\\psi$ Production in High-Energy Nucleus-Nucleus Collisions

    Wong, C Y

    1998-01-01

    We use the Drell-Yan differential distribution dN_{DY}^{AB}/dE_T in high-energy nucleus-nucleus collisions to obtain a relation between the transverse energy E_T and the impact parameter b. Such a relation is then utilized to study the transverse-energy dependence of J/psi production in Pb-Pb collisions, using the J/psi absorption model presented previously. The anomalous Pb-Pb suppression data at 158A GeV can be explained if one assumes the occurrence of a new phase of strong J/psi absorption when the energy density exceeds 4.2 GeV/fm^3. The results are extended to make predictions for J/psi production at higher collision energies. It is found that J/psi survival probabilities reach the lowest survival limit when the nucleon-nucleon center-of-mass energies is greater than about 35 GeV.

  14. Medium effect in high-density nuclear matter probed by systematic analyses of nucleus-nucleus elastic scattering

    Furumoto, T; Yamamoto, Y

    2016-01-01

    We investigate the property of the high-density nuclear matter probed by the nucleus-nucleus elastic scattering in the framework of the double-folding (DF) model with the complex $G$-matrix interaction. The medium effect including three-body-force (TBF) effect is investigated with present two methods based on the frozen density approximation. With the both methods, the medium effect in the high density region is clearly seen on the potential and the elastic cross section of the $^{16}$O + $^{16}$O system at $E/A =$ 70 MeV. The crucial role of the medium effect for the high-density nuclear matter is also confirmed with other effective nucleon-nucleon ($NN$) interactions. In addition, present methods are applied to other heavy-ion elastic scattering systems. Again, the medium effect in the high-density region is clearly seen in the heavy-ion elastic cross section. The effect on the elastic cross section becomes invisible with the increase of the target mass and the incident energy within existing the experiment...

  15. Charged pion production in nucleus-nucleus collisions at E/A between 400 and 800 mev

    This thesis is devoted to the experimental study of pion production in relativistic heavy ions collisions. The first two chapters introduce the basic concepts and offer a review of the currently used theoretical models. The data presented were taken at the SATURNE accelerator with the DIOGENE detector (chapter III). The last part is totally devoted to our results. The data analysis is described, with an emphasis on the impact parameter selection. The pion multiplicity is systematically studied as concerns its various aspects and implications. The impact parameter, beam energy and system size dependence are presented and compared with the results of intranuclear cascade calculation. The possibility of determining the nuclear equation of state from this comparison is discussed. The pion multiplicity distribution is consistent with a Poisson law which rules out any coherent pion production mechanism. The double differential cross-sections are then presented for large and small impact parameters. The question of pion origin in heavy ion collisions is discussed by tagging the one nucleus-nucleus inelastic collision process and the delta resonance contribution. Finally, a systematic study of pion flow is given along with a possible explanation by pion absorption in nuclear matter

  16. Charged pion production in nucleus-nucleus collisions AT E/A between 400 and 800 MeV

    This thesis is devoted to the experimental study of pion production in relativistic heavy ions collisions. The first two chapters introduce the basic concepts and offer a review of the currently used theoretical models. The data presented were taken at the SATURNE accelerator with the DIOGENE detector. The last part is totally devoted to our results. The data analysis is described, with an emphasis on the impact parameter selection. The pion multiplicity is systematically studied as concerns its various aspects and implications. The impact parameter, beam energy and system size dependence are presented and compared with the results of intranuclear cascade calculation. The possibility of determining the nuclear equation of state from this comparison is discussed. The pion multiplicity distribution is consistent with a Poisson law which rules out any coherent pion production mechanism. The double differential cross-sections are then presented for large and small impact parameters. The question of pion origin in heavy ion collisions is discussed by tagging the on nucleus-nucleus inelastic collision process and the delta resonance contribution. Finally, a systematic study of pion flow is given along with a possible explanation by pion absorption in nuclear matter

  17. Study of the Pion Production Mechanisms in Nucleus-Nucleus Collisions at the CERN SC using the Omicron Spectrometer

    2002-01-01

    The aim of this experiment is to study the pion production mechanism in nucleus-nucleus collisions with the |3He and |1|2C beams of the CERN SC using the Omicron Spectrometer. The high intensity ion beams delivered now by the SC combined with the favourable characteristics of the Omicron Spectrometer offer a unique possibility of measuring very low cross-sections (typically in the order of 1 pb/(sr~MeV/c). In a first stage we will measure with an energy resolution of about 3~MeV the spectra of @p@+ emitted at 0|0 in two-body reactions induced by |3He ions of 910~MeV on targets of |6Li, |7Li, |9Be and |1|2C. The aim is to understand the reaction mechanisms and the nuclear wave functions most appropriate to describe the formation of nuclear bound states at momentum transfers of about 1.6@/1.7~GeV/c. The apparatus is shown in the figure. The same instrument will allow the measurement of the @p@+ inclusive spectra emitted at 0|0 after the interaction of the |1|2C|4|+ beam at 1032 MeV with the same targets. At 86 ...

  18. New - Nucleus - NucNet. The ENS triple communication system

    The ENS triple communication system was built up as a step-by-step response to practical needs. In fact the triple communication system has the fourth issue, namely WINFO. Nuclear Europe was started in 1981 with three pilot issues. Now, Nuclear Europe Worldscan has become an integrator, between over 20 000 members of ENS Member Societies, from the Atlantic to the Urals and beyond; an integrator between Europe and the rest-of-the world nuclear community; between industry and science and engineering; between the bosses and the staff; and finally, an integrator between the nuclear community and those outsiders who take an interest in nuclear issues. Nucleus started in 1987, selected by the ENS Steering Committee for as the most worthwhile for transferring messages from nuclear community to the politicians and opinion-leaders, i.e. to non-technical outsiders. It is a briefing sheet for people who work with key policy principles, politicians and journalists. It is designed and written for people having no time to read. The keys to each two-page Nucleus are headlines. Nucleus appears in English, French, Croatian, Russian, Dutch, Hungarian, Romanian and Finnish. When the need grew really urgent for Europe, the ENS Information Committee proposed a feasibility study, which the European nuclear community entrusted to ENS in 1989. NucNet was launched in January 1991 - first as a European, and later as a truly worldwide, communications system. NucNet is the worldwide network which circulates nuclear news and information that the public should be informed of, written in a language that the public can easily understand. NucNet is highly appreciated, for instance, by NPP managers because they are informed about incidents faster than by any other means. But, NucNet is not merely an incident reporting system. (As a general rule, the network only reports on incidents in nuclear plants if they are rated at level 2 or above on the IAEA's International Nuclear Event Scale). The more

  19. Reactions with the double-Borromean nucleus 8He

    Differential cross sections for elastic-scattering and neutron-transfer reactions along with cross sections for fusion in the 8He+65Cu system are reported at energies above the Coulomb barrier (Elab= 19.9 and 30.6 MeV). The present work demonstrates the feasibility of using inclusive measurements of characteristic in-beam γ rays with low-intensity (∼105 pps) radioactive ion beams to obtain the residue cross sections for fusion and neutron transfer. Exclusive measurements of γ rays in coincidence with light charged particles have been used to further characterize the direct reactions induced by this double-Borromean nucleus. Coupled reaction channels calculations are used to illustrate the important role played by the transfer channels and to help in understanding the influence of the structure of 8He on the reaction mechanism.

  20. Neuropsychological functioning following bilateral subthalamic nucleus stimulation in Parkinson's disease.

    Morrison, C E; Borod, J C; Perrine, K; Beric, A; Brin, M F; Rezai, A; Kelly, P; Sterio, D; Germano, I; Weisz, D; Olanow, C W

    2004-03-01

    The cognitive effects of subthalamic nucleus (STN) stimulation in Parkinson's disease (PD) have been examined. However, there are no reported studies that evaluate, by incorporating a disease control group, whether neuropsychological performance in surgical patients changes beyond the variability of the assessment measures. To examine this issue, 17 PD patients were tested before and after bilateral STN stimulator implantation, both on and off stimulation. Eleven matched PD controls were administered the same repeatable neuropsychological test battery twice. Relative to changes seen in the controls, the surgery for electrode placement mildly adversely affected attention and language functions. STN stimulation, per se, had little effect on cognition. The STN DBS procedure as a whole resulted in a mild decline in delayed verbal recall and language functions. There were no surgery, stimulation, or procedure effects on depression scale scores. In contrast to these group findings, one DBS patient demonstrated significant cognitive decline following surgery. PMID:15010083

  1. Cluster structure and collective behavior of the nucleus 48Cr

    The structure of the nucleus 48Cr was investigated by the 40Ca+α+α orthogonality condition model (OCM). The energy spectra, electromagnetic transitions, and spectroscopic factors for the α+ 44Ti and 8Be+ 40Ca channels were calculated and are discussed herein. The observed energies and E2 transitions of the yrast band, which show collective behavior, were found to be well reproduced by the cluster model. Some exotic 2α-cluster states with ''Ca-α-α''- and ''α-Ca-α''-like configurations are predicted near the 2α threshold. The structures of the states were analyzed through the wave functions. The mechanism of backbending of the yrast band can be explained naturally in terms of the cluster-coupling scheme

  2. The LHC as a Proton-Nucleus Collider

    Carli, C

    2006-01-01

    Following its initial operation as a proton-proton (p-p) and heavy-ion (208Pb82+-208Pb82+) collider, the LHC is expected to operate as a p-Pb collider. Later it may collide protons with other lighter nuclei such as 40Ar18+ or 16O8+. We show how the existing proton and lead-ion injector chains may be efficiently operated in tandem to provide these hybrid collisions. The two-in-one magnet design of the LHC main rings imposes different revolution frequencies for the two beams in part of the magnetic cycle. We discuss and evaluate the consequences for beam dynamics and estimate the potential performance of the LHC as a proton-nucleus collider.

  3. Structure of the nucleus of the Seyfert galaxy NGC 1275

    Matveenko, L.I.; Kellermann, K.I.; Pauliny-Toth, I.I.K.; Kostenko, V.I.; Moiseev, I.G.; Kogan, L.R.; Witzel, A.; Roennaeng, B.O.; Shaffer, D.B.; Preuss, E.

    1980-01-01

    The nucleus of the Seyfert galaxy NGC 1275 has been surveyed at 1.35-cm wavelength with the Haystack--Green Bank--Effelsberg--Onsala--Crimea radio-interferometer network. Its structure comprises eastern and western systems of features, separated by 0.7 pc. The eastern system has a core embedded in an absorbing medium whose electron density depends on distance L as N/sub e/approx. =4 x 10/sup 45/ L/sup -2.3plus-or-minus0.5/. The compact components, which measure approx. =0''.0001 across, have a magnetic field strength Happrox. =0.3 gauss. All fine-structure components maintain stable positions, but their brightness is variable. The radio brightness distribution is probably governed by the magnetic field structure.

  4. The Subthalamic Nucleus During Decision-Making With Multiple Alternatives

    Bogacz, Rafal; Schäfer, Andreas; Neumann, Jane; Turner, Robert; Forstmann, Birte U.

    2016-01-01

    Several prominent neurocomputational models predict that an increase of choice alternatives is modulated by increased activity in the subthalamic nucleus (STN). In turn, increased STN activity allows prolonged accumulation of information. At the same time, areas in the medial frontal cortex such as the anterior cingulate cortex (ACC) and the pre-SMA are hypothesized to influence the information processing in the STN. This study set out to test concrete predictions of STN activity in multiple-alternative decision-making using a multimodal combination of 7 Tesla structural and functional Magnetic Resonance Imaging, and ancestral graph (AG) modeling. The results are in line with the predictions in that increased STN activity was found with an increasing amount of choice alternatives. In addition, our study shows that activity in the ACC is correlated with activity in the STN without directly modulating it. This result sheds new light on the information processing streams between medial frontal cortex and the basal ganglia. PMID:26178078

  5. MR imaging of intra- and extraforaminal herniated nucleus pulposus

    Prospective evaluation of 42 patients with clinical lumbar radiculopathy were evaluated with T1-weighted, spin density, and T2-weighted sagittal (5 mm) and axial (3 mm) MR imaging at 1.5 T. Five-millimeter simple or compound oblique T1-weighted imaging (4 nex, 128 X 256) with biplanar flow-void saturation to reduce coherent motion-related noise was implemented bilaterally (n = 14) or on the affected side (n = 28). Six cases of intra- or extraforminal herniated nucleus pulposus (HNP) were prospectively identified on MR imaging. All patients subsequently underwent CT and surgery. Direct simple or compound oblique MR imaging, at least on the affected side, may be routinely necessary in assessment of lumbar radiculopathy, particularly when foraminal or extraforaminal HNP is suspected

  6. Dynamical Analysis of Protein Regulatory Network in Budding Yeast Nucleus

    LI Fang-Ting; JIA Xun

    2006-01-01

    @@ Recent progresses in the protein regulatory network of budding yeast Saccharomyces cerevisiae have provided a global picture of its protein network for further dynamical research. We simplify and modularize the protein regulatory networks in yeast nucleus, and study the dynamical properties of the core 37-node network by a Boolean network model, especially the evolution steps and final fixed points. Our simulation results show that the number of fixed points N(k) for a given size of the attraction basin k obeys a power-law distribution N(k)∝k-2.024. The yeast network is more similar to a scale-free network than a random network in the above dynamical properties.

  7. Modelling diffusional transport in the interphase cell nucleus

    Wedemeier, Annika; Wu, Chen-Xu; Langowski, Jörg

    2007-01-01

    In this paper a lattice model for diffusional transport of particles in the interphase cell nucleus is proposed. Dense networks of chromatin fibers are created by three different methods: randomly distributed, non-interconnected obstacles, a random walk chain model, and a self avoiding random walk chain model with persistence length. By comparing a discrete and a continuous version of the random walk chain model, we demonstrate that lattice discretization does not alter particle diffusion. The influence of the 3D geometry of the fiber network on the particle diffusion is investigated in detail, while varying occupation volume, chain length, persistence length and walker size. It is shown that adjacency of the monomers, the excluded volume effect incorporated in the self avoiding random walk model, and, to a lesser extent, the persistence length, affect particle diffusion. It is demonstrated how the introduction of the effective chain occupancy, which is a convolution of the geometric chain volume with the wal...

  8. Green's function in the color field of a large nucleus

    We compute the Green's function for scalars, fermions, and vectors in the color field associated with the infinite momentum frame wave function of a large nucleus. Expectation values of this wave function can be computed by integrating over random orientations of the valence quark charge density. This relates the Green's functions to correlation functions of a two-dimensional, ultraviolet finite, field theory. We show how one can compute the sea quark distribution functions and explicitly compute them in the kinematic range of transverse momenta, αs2μ2 much-lt kt2 much-lt μ2, where μ2 is the average color charge squared per unit area. When mquark2 much-lt μ2∼A1/3, the sea quark contribution to the infinite momentum frame wave function saturates at a value that is the same as that for massless sea quarks

  9. Likelihood analysis of parity violation in the compound nucleus

    We discuss the determination of the root mean-squared matrix element of the parity-violating interaction between compound-nuclear states using likelihood analysis. We briefly review the relevant features of the statistical model of the compound nucleus and the formalism of likelihood analysis. We then discuss the application of likelihood analysis to data on panty-violating longitudinal asymmetries. The reliability of the extracted value of the matrix element and errors assigned to the matrix element is stressed. We treat the situations where the spins of the p-wave resonances are not known and known using experimental data and Monte Carlo techniques. We conclude that likelihood analysis provides a reliable way to determine M and its confidence interval. We briefly discuss some problems associated with the normalization of the likelihood function

  10. Hadron dynamics in high-energy pion-nucleus scattering

    It is argued that pion-nucleus scattering at high energy (above 300 MeV) is likely to be easier to interpret than it has been at lower energies where the Δ33 resonance dominates. We establish this by examining the relative importance of various dynamic ingredients of scattering theory for high-energy pions and comparing different versions of the theory: a ''model-exact'' microscopic optical model and an eikonal approximation. For nuclei as heavy as Ca, the eikonal theory is an excellent approximation to the full theory for the angular distribution out to the position of the second minimum in the cross section. The prospects for using high-energy pions to examine modifications of nucleons and baryon resonances in nuclei, nuclear structure, exchange currents, short-range correlations, and to characterize pion propagation are discussed

  11. How to rule the nucleus: divide et impera.

    Solovei, Irina; Thanisch, Katharina; Feodorova, Yana

    2016-06-01

    Genome-wide molecular studies have provided new insights into the organization of nuclear chromatin by revealing the presence of chromatin domains of differing transcriptional activity, frequency of cis-interactions, proximity to scaffolding structures and replication timing. These studies have not only brought our understanding of genome function to a new level, but also offered functional insight for many phenomena observed in microscopic studies. In this review, we discuss the major principles of nuclear organization based on the spatial segregation of euchromatin and heterochromatin, as well as the dynamic genome rearrangements occurring during cell differentiation and development. We hope to unite the existing molecular and microscopic data on genome organization to get a holistic view of the nucleus, and propose a model, in which repeat repertoire together with scaffolding structures blueprint the functional nuclear architecture. PMID:26938331

  12. Ferrofluid nucleus phase transitions in an external uniform magnetic field

    B. M. Tanygin; S. I. Shulyma; V. F. Kovalenko; M. V. Petrychuk

    2015-01-01

    The phase transition between a massive dense phase and a diluted superparamagnetic phase has been studied by means of a direct molecular dynamics simulation. The equilibrium structures of the ferrofluid aggregate nucleus are obtained for different values of a temperature and an external magnetic field magnitude. An approximate match of experiment and simulation has been shown for the ferrofluid phase diagram coordinates “field–temperature”. The provided phase coexistence curve has an opposite trend comparing to some of known theoretical results. This contradiction has been discussed. For given experimental parameters, it has been concluded that the present results describe more precisely the transition from linear chains to a dense globes phase. The theoretical concepts which provide the opposite binodal curve dependency trend match other experimental conditions:a diluted ferrofluid, a high particle coating rate, a high temperature, and/or a less particles coupling constant value.

  13. Input/output properties of the lateral vestibular nucleus

    Boyle, R.; Bush, G.; Ehsanian, R.

    2004-01-01

    This article is a review of work in three species, squirrel monkey, cat, and rat studying the inputs and outputs from the lateral vestibular nucleus (LVN). Different electrophysiological shock paradigms were used to determine the synaptic inputs derived from thick to thin diameter vestibular nerve afferents. Angular and linear mechanical stimulations were used to activate and study the combined and individual contribution of inner ear organs and neck afferents. The spatio-temporal properties of LVN neurons in the decerebrated rat were studied in response to dynamic acceleration inputs using sinusoidal linear translation in the horizontal head plane. Outputs were evaluated using antidromic identification techniques and identified LVN neurons were intracellularly injected with biocytin and their morphology studied.

  14. The global optical potentials and neutron - Nucleus scattering data

    We have compared the predictions of three global optical potentials with the (21.6 MeV) neutron-nucleus elastic scattering data. Nine nuclides within the mass range 40 ≤ A ≤ 209 were chosen for this comparative study. By fitting the differential cross-section data with Legendre polynomials, it was possible to plot the ratio of theoretical and experimental cross sections as a function of scattering angle. Significant deviations of this ratio occur at the positions of diffraction maxima and minima. The integrated quantities i.e. total elastic cross sections, volume integrals and mean-square-radii for the three potentials under consideration have also been calculated and compared with the corresponding values obtained by using individual best fit potentials. (author). 18 refs, 3 figs, 3 tabs

  15. An eccentric disk model for the nucleus of M31

    Tremaine, S

    1995-01-01

    The nucleus of M31 may be a thick eccentric disk, composed of stars traveling on nearly Keplerian orbits around a black hole or other dark compact object. This hypothesis reproduces most of the features seen in HST photometry of the center of M31; in particular the bright off-center source P1 is the apoapsis of the disk. An eccentric disk can also explain the rotation curve and asymmetric dispersion profile revealed by ground-based observations. The central object must be smaller than 1 pc so that the potential felt by the disk is nearly Keplerian. The disk eccentricity may be excited by a secular instability driven by dynamical friction from the bulge.

  16. Kaon pair production in proton-nucleus collisions

    Kiselev, Yu T; Polyanskiy, A; Paryev, E Ya; Barsov, S; Buescher, M; Dymov, S; Gebel, R; Hejny, V; Kacharava, A; Keshelashvili, I; Lorentz, B; Maeda, Y; Merzliakov, S; Mikirtytchiants, S; Ohm, H; Serdyuk, V; Sibirtsev, A; Sinitsyna, V Y; Stein, H J; Stroeher, H; Trusov, S; Valdau, Yu; Wilkin, C; Wuestner, P; Ye, Q J

    2015-01-01

    The production of non-phi K+K- pairs by protons of 2.83 GeV kinetic energy on C, Cu, Ag, and Au targets has been investigated using the COSY-ANKE magnetic spectrometer. The K- momentum dependence of the differential cross section has been measured at small angles over the 0.2--0.9 GeV/c range. The comparison of the data with detailed model calculations indicates an attractive K- -nucleus potential of about -60 MeV at normal nuclear matter density at a mean momentum of 0.5 GeV/c. However, this approach has difficulty in reproducing the smallness of the observed cross sections at low K- momenta.

  17. Cloud condensation nucleus behaviour of selected dicarboxylic acids

    Poulsen, Mia Frosch Mogensbæk; Nielsen, Ole Faurskov; Bilde, Merete

    .g. Anttila et al, 2005). Particles composed of two such compounds, namely glutaric acid and pimelic acid, have been studied using a cloud condensation nucleus counter (University of Wyoming, Model 100B). The behaviour of pimelic acid seems to agree quite well with the predictions of Köhler theory. This......, however, is not the case for glutaric acid. A likely explanation is that this rather volatile compound evaporates significantly from the surface of a particle. Attempts have therefore been made to correct for this evaporation, and the results show a much better agreement with Köhler theory. The...... Riekkola, M.L , Determination of organic acids in aerosol particles from a coniferous forest by liquid chromatography-mass spectrometry, Journal of Separation Science, 28, 337-346, 2005....

  18. Compound nucleus formation in reactions between massive nuclei. Fusion barrier

    The evaporation residue cross sections σER in reactions between massive nuclei have been analyzed within different models of complete fusion. The calculations in the framework of the optical model, the surface friction model and the macroscopic dynamic model can give the results which are by few orders of magnitude different from experimental data. This takes place due to neglect of the competition between complete fusion and quasifission. A possible mechanism of compound nucleus formation in heavy ion-induced reaction has been suggested. A model is proposed for calculation of this competition in a massive symmetric dinuclear system. This model is applied for collision energies above the Coulomb barrier. The σER values calculated in the framework of the approach suggested seem to be close to the experimental data. For illustration the reactions 100Mo + 100Mo, 110Pd + 110Pd and 124Sn + 96Zn have been considered. 35 refs., 6 figs

  19. Deuterium target data and precision neutrino-nucleus cross sections

    Meyer, Aaron S; Gran, Richard; Hill, Richard J

    2016-01-01

    Amplitudes derived from scattering data on elementary targets are basic inputs to neutrino-nucleus cross section predictions. A prominent example is the isovector axial nucleon form factor, $F_A(q^2)$, which controls charged current signal processes at accelerator-based neutrino oscillation experiments. Previous extractions of $F_A$ from neutrino-deuteron scattering data rely on a dipole shape assumption that introduces an unquantified error. A new analysis of world data for neutrino-deuteron scattering is performed using a model-independent, and systematically improvable, representation of $F_A$. A complete error budget for the nucleon isovector axial radius leads to $r_A^2=0.46(22) \\,{\\rm fm}^2$, with a much larger uncertainty than determined in the original analyses. The quasielastic neutrino-neutron cross section is determined as $\\sigma(\

  20. Total absorption spectroscopy of N = 51 nucleus 85Se

    Goetz, K. C.; Grzywacz, R. K.; Rykaczewski, K. P.; Karny, M.; Fialkowska, A.; Wolinska-Cichocka, M.; Rasco, B. C.; Zganjar, E. F.; Johnson, J. W.; Gross, C. J.

    2014-09-01

    An experimental campaign utilizing the Modular Total Absorption Spectrometer (MTAS) was conducted at the HRIBF facility in January of 2012. The campaign studied 22 isotopes, many of which were identified as the highest priority for decay heat analysis during a nuclear fuel cycle, see the report by the OECD-IAEA Nuclear Energy Agency in 2007. The case of 85Se will be discussed. 85Se is a Z = 34, N = 51 nucleus with the valence neutron located in the positive parity sd single particle state. Therefore, its decay properties are determined by interplay between first forbidden decays of the valence neutron and Gamow-Teller decay of a 78Ni core. Analysis of the data obtained during the January 2012 run indicates a significant increase of the beta strength function when compared with previous measurements, see Ref..

  1. Collective bands in neutron-rich 104Mo nucleus

    Levels in the neutron-rich 104Mo nucleus have been investigated by observing prompt γ-rays from the spontaneous fission of 252Cf with the Gamma sphere detector array. The ground-state band, the one-phonon and the two-phonon γ-vibrational bands as well as a quasiparticle band have been confirmed and expanded with spin up to 14ℎ. Other two side bands probably built on new quasiparticle states are identified. The possible configurations for the quasiparticle bands are discussed. Two of the quasiparticle bands show larger moments of inertia and may have pair-free characteristics. The levels of the ground-state band, the one-phonon γ-band and the two-phonon γ-band calculated from a general collective model are in close agreement with the experimental data

  2. Collective bands in neutron-rich 107Ru nucleus

    Through measuring prompt γ-rays emitted in the spontaneous fission of 252Cf with higher statistic data, level structures in the neutron-rich, odd-A 107Ru nucleus have been re-investigated. New level scheme of 107Ru has been established. The ground state band was extended with spin up to 27/2ℎ. The νh11/2 band structure observed in authors' previous publication has been confirmed and extended. These results clear up the inconsistence between authors' earlier work and results from another experiment published recently. A collective band built on (9/2-) level has been observed for the first time. Some important features of the level scheme have been discussed

  3. The suprachiasmatic nucleus: age-related decline in biological rhythms.

    Nakamura, Takahiro J; Takasu, Nana N; Nakamura, Wataru

    2016-09-01

    Aging is associated with changes in sleep duration and quality, as well as increased rates of pathologic/disordered sleep. While several factors contribute to these changes, emerging research suggests that age-related changes in the mammalian central circadian clock within the suprachiasmatic nucleus (SCN) may be a key factor. Prior work from our group suggests that circadian output from the SCN declines because of aging. Furthermore, we have previously observed age-related infertility in female mice, caused by a mismatch between environmental light-dark cycles and the intrinsic, internal biological clocks. In this review, we address regulatory mechanisms underlying circadian rhythms in mammals and summarize recent literature describing the effects of aging on the circadian system. PMID:26915078

  4. Intrinsic properties and neuropharmacology of midline paraventricular thalamic nucleus neurons.

    Miloslav Kolaj

    2014-04-01

    Full Text Available Neurons in the midline and intralaminar thalamic nuclei are components of an interconnected brainstem, limbic and prefrontal cortex neural network that is engaged during arousal, vigilance, motivated and addictive behaviors, and stress. To better understand the cellular mechanisms underlying these functions, here we review some of the recently characterized electrophysiological and neuropharmacological properties of neurons in the paraventricular thalamic nucleus (PVT, derived from whole cell patch clamp recordings in acute rat brain slice preparations. PVT neurons display firing patterns and ionic conductances (IT and IH that exhibit significant diurnal change. Their resting membrane potential is maintained by various ionic conductances that include inward rectifier (Kir, hyperpolarization-activated nonselective cation (HCN and TWIK-related acid sensitive (TASK K+ channels. Firing patterns are regulated by high voltage-activated (HVA and low voltage-activated (LVA Ca2+ conductances. Moreover, transient receptor potential (TRP-like nonselective cation channels together with Ca2+- and Na+-activated K+ conductances (KCa; KNa contribute to unique slow afterhyperpolarizing potentials (sAHPs that are generally not detectable in lateral thalamic or reticular thalamic nucleus neurons. We also report on receptor-mediated actions of GABA, glutamate, monoamines and several neuropeptides: arginine vasopressin, gastrin-releasing peptide, thyrotropin releasing hormone and the orexins (hypocretins. This review represents an initial survey of intrinsic and transmitter-sensitive ionic conductances that are deemed to be unique to this population of midline thalamic neurons, information that is fundamental to an appreciation of the role these thalamic neurons may play in normal central nervous system (CNS physiology and in CNS disorders that involve the dorsomedial thalamus.

  5. Role of the hypothalamic arcuate nucleus in cardiovascular regulation.

    Sapru, Hreday N

    2013-04-01

    Recently the hypothalamic arcuate nucleus (Arc) has been implicated in cardiovascular regulation. Both pressor and depressor responses can be elicited by the chemical stimulation of the Arc. The direction of cardiovascular responses (increase or decrease) elicited from the Arc depends on the baseline blood pressure. The pressor responses are mediated via increase in sympathetic nerve activity and involve activation of the spinal ionotropic glutamate receptors. Arc-stimulation elicits tachycardic responses which are mediated via inhibition of vagal input and excitation of sympathetic input to the heart. The pathways within the brain mediating the pressor and tachycardic responses elicited from the Arc have not been delineated. The depressor responses to the Arc-stimulation are mediated via the hypothalamic paraventricular nucleus (PVN). Gamma aminobutyric acid type A receptors, neuropeptide Y1 receptors, and opiate receptors in the PVN mediate the depressor responses elicited from the Arc. Some circulating hormones (e.g., leptin and insulin) may reach the Arc via the leaky blood-brain barrier and elicit their cardiovascular effects. Although the Arc is involved in mediating the cardiovascular responses to intravenously injected angiotensin II and angiotensin-(1-12), these effects may not be due to leakage of these peptides across the blood-brain barrier in the Arc; instead, circulating angiotensins may act on neurons in the SFO and mediate cardiovascular actions via the projections of SFO neurons to the Arc. Cardiovascular responses elicited by acupuncture have been reported to be mediated by direct and indirect projections of the Arc to the RVLM. PMID:23260431

  6. A universal description of pseudorapidity distributions in both nucleus-nucleus and p-p collisions at now available energy regions

    Jiang, Z J; Huang, Y

    2016-01-01

    Investigations have shown that the collective motion not only appears in nucleus-nucleus but also in p-p collisions. The best tool for depicting such collective motion is relativistic hydrodynamics. In this paper, the collective motion is assumed obeying the hydro model which integrates the features of Landau and Hwa-Bjorken theory and is one of a very few analytically solvable models. The fluid is then supposed freezing out into charged particles from a time-like hypersurface with a fixed time of t_FO . The researches of present paper show that this part of charged particles together with leading particles, which, by conventional definition, carry on the quantum numbers of colliding nucleons and take away the most part of incident energy, can give a proper universal description to the pseudorapidity distributions of charged particles measured in both nucleus-nucleus and p-p collisions at now available energy regions.

  7. Simulation of nucleus-nucleus interactions in the framework of the FRITIOF model at the energy of 3.3 GeV/nucleon

    The intranuclear cascade model overestimates the multiplicity of produced mesons in nucleus-nucleus interactions without taking into account meson and baryon resonance production. Inclusion of the resonances leads to decreasing multiplicity of mesons, neutrons and protons. In order to overcome the problem, it is proposed to use the FRITIOF model adapted to low energies in a combination with the reggeon theory inspired model of nuclear destruction. It is shown that the combination allows one to reproduce satisfactory the meson and baryon yields in the nucleus-nucleus collisions at the energy of 3.3 GeV/nucleon. The combined model works faster than typical quantum molecular dynamic model, and allows one to estimate the data needed for creation of electro-nuclear amplifier

  8. GABAergic projections to the oculomotor nucleus in the goldfish (Carassius auratus

    Luis Herrero

    2011-02-01

    Full Text Available The mammalian oculomotor nucleus receives a strong -aminobutyric acid (GABAergic synaptic input, whereas such projections have rarely been reported in fish. In order to determine whether this synaptic organization is preserved across vertebrates, we investigated the GABAergic projections to the oculomotor nucleus in the goldfish by combining retrograde transport of biotin dextran amine, injected into the antidromically identified oculomotor nucleus, and GABA immunohistochemistry. The main source of GABAergic afferents to the oculomotor nucleus was the ipsilateral anterior octaval nucleus, with only a few, if any, GABAergic neurons being located in the contralateral tangential and descending nuclei of the octaval column. In mammals there is a nearly exclusive ipsilateral projection from vestibular neurons to the oculomotor nucleus via GABAergic inhibitory inputs; thus, the vestibulooculomotor GABAergic circuitry follows a plan that appears to be shared throughout the vertebrate phylogeny. The second major source of GABAergic projections was the rhombencephalic reticular formation, primarily from the medial area but, to a lesser extent, from the inferior area. A few GABAergic oculomotor projecting neurons were also observed in the ipsilateral nucleus of the medial longitudinal fasciculus. The GABAergic projections from neurons located in both the reticular formation surrounding the abducens nucleus and the nucleus of the medial reticular formation have primarily been related to the control of saccadic eye movements. Finally, all retrogradely labeled internuclear neurons of the abducens nucleus, and neurons in the cerebellum (close to the caudal lobe, were negative for GABA. These data suggest that the vestibuloocular and saccadic inhibitory GABAergic systems appear early in vertebrate phylogeny to modulate the firing properties of the oculomotor nucleus motoneurons.

  9. The possibility of observing gamma radiation associated with the formation and pre-equilibrium emission of alpha particles in nucleus-nucleus collisions

    In this paper the experiment to study the emergence of the γ-quanta with energy equal to the binding energy of the composite particles emitted from the interaction region of nucleus-nucleus collisions. If this effect will be detected and recorded above the background of the bremsstrahlung γ-qu ants, a new method for the experimental study of the γ-emission of brake mechanism of the discharge strongly heated nuclear systems.

  10. GABA signaling in the nucleus tractus solitarius sets the level of activity in dorsal motor nucleus of the vagus cholinergic neurons in the vagovagal circuit

    Herman, Melissa A.; Cruz, Maureen T.; Sahibzada, Niaz; Verbalis, Joseph; Gillis, Richard A.

    2008-01-01

    It has been proposed that there is an “apparent monosynaptic” connection between gastric vagal afferent nerve terminals and inhibitory projection neurons in the nucleus tractus solitarius (NTS) and that two efferent parallel pathways from the dorsal motor nucleus of the vagus (DMV) influence peripheral organs associated with these reflexes (6). The purpose of our study was to verify the validity of these views as they relate to basal control of gastric motility. To test the validity of a dire...

  11. Corticotropin-releasing factor within the central nucleus of the amygdala and the nucleus accumbens shell mediates the negative affective state of nicotine withdrawal in rats

    Marcinkiewcz, Catherine A.; Prado, Melissa M.; Isaac, Shani K.; Marshall, Alex.; Rylkova, Daria; Bruijnzeel, Adrie W.

    2009-01-01

    Tobacco addiction is a chronic disorder that is characterized by a negative affective state upon smoking cessation and relapse after periods of abstinence. Previous research has shown that an increased central release of corticotropin-releasing factor (CRF) at least partly mediates the deficit in brain reward function associated with nicotine withdrawal in rats. The aim of these studies was to investigate the role of CRF in the central nucleus of the amygdala (CeA), the lateral bed nucleus of...

  12. Multiplicity distribution of final-state particles and different contributions of related Sources in nucleus-nucleus collisions at high energies

    SUN Zhu; LIU Pu-Hu

    2008-01-01

    The final state particle multiplicity distributions in high-energy nucleus-nucleus collisions are described by two different sub-distributious contributed by a single nucleon.The Monte Carlo calculated results from the two sub-distributions and the participant-spectator model are compared and found to be in agreement with the experimental data of Au-Au collisions ats=130 AGeV and Pb-Pb collisions at 158 AGeV.

  13. Target fragmentation in proton-nucleus and 16O-nucleus reactions at 60 and 200 GeV/nucleon

    Target remnants with Z16O-nucleus reactions at 60 and 200 GeV/nucleon were measured in the angular range from 300 to 1600 (-1.7 16O-induced reactions (≅ 300 MeV/c) than in proton-induced reactions (≅ 130 MeV/c). The baryon rapidity distributions are roughly in agreement with one-fluid hydrodynamical calculations at 60 GeV/nucleon 16O+Au but are in disagreement at 200 GeV/nucleon, indicating the higher degree of transparency at the higher bombarding energy. Both, the transverse momenta of target spectators and the entropy produced in the target fragmentation region are compared to those attained in head-on collisions of two heavy nuclei at Bevalac energies. They are found to be comparable or do even exceed the values for the participant matter at beam energies of about 1-2 GeV/nucleon. (orig.)

  14. Nuclear sizes and intranuclear matter distribution -- from hadron-nucleus collisions

    The method of intranuclear matter studies by hadronic projectiles is found and worked out. It is tested on the pion-xenon nucleus collision events. Target-nucleus size and nucleon density distributions in it were estimated and described by formulas prompted experimentally

  15. A stereological study of the mediodorsal thalamic nucleus in Down syndrome

    Karlsen, A S; Korbo, S; Uylings, H B M;

    2014-01-01

    The total number of neurons and glial cells in the mediodorsal thalamic (MDT) nucleus of four aged females with Down syndrome (DS; mean age 69years) was estimated and compared to six age- and sex-matched controls. The MDT nucleus was delineated on coronal sections, and cell numbers (large and small...

  16. Pitx3 deficiency in mice affects cholinergic modulation of GABAergic synapses in the nucleus accumbens

    de Rover, Mischa; Lodder, Johannes C.; Smidt, Marten P.; Brussaard, Arjen B.

    2006-01-01

    Pitx3 deficiency in mice affects cholinergic modulation of GABAergic synapses in the nucleus accumbens. J Neurophysiol 96: 2034-2041, 2006. First published July 12, 2006; doi:10.1152/jn.00333.2006. We investigated to what extent Pitx3 deficiency, causing hyperdopaminergic transmission in the nucleus

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

    The quasi-elastic ν-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 16O target

  18. The Nucleus Premammillaris Ventralis (PMV) and Aggressive Behavior in the Rat

    Berg, M.J. van den; Horst, G.J. ter; Koolhaas, J.M.

    1983-01-01

    Small bilateral electrolytic lesions placed just posterior of the ventromedial hypothalamic nucleus cause a strong increase in offensive behavior. The histology suggests that damage to the ventral premanimillary nucleus is responsible for this effect. A summary of the neuroanatomical literature show

  19. Nucleus basalis prosencephali, a substrate of apomorphine-induced pecking in pigeons

    Delius, Juan; Lindenblatt, Ulrike

    1988-01-01

    Microinjections of the dopamine agonist apomorphine into the nucleus basalis prosencephali of pigeons elicit stereotyped pecking behaviour. Injections of 6-hydroxydopamine, a toxic dopamine antagonist, into the same nucleus impair stereotyped pecking induced by systemic apomorphine administration, but do not interfere with pecking in the normal feeding context.

  20. Age-dependent effects of conditioning on cholinergic and vasopressin systems in the rat suprachiasmatic nucleus

    Biemans, BAM; Van der Zee, EA; Daan, S

    2003-01-01

    Active shock avoidance was used to explore the impact of behavioural stimulation on the neurochemistry of the suprachiasmatic nucleus. We have found previously that the expression of muscarinic acetylcholine receptors in the suprachiasmatic nucleus of young rats was significantly enhanced 24 hours a

  1. Nuclear dynamics of bound eta mesons: Eta-mesic nuclei and mesic compound-nucleus resonances

    The theory of eta-mesic nuclei is reviewed and the experiments designed to search for them are described. A theory of mesic compound nuclear resonances is presented which allow a study of the effects of eta-nucleus bound states on other meson-nucleus reactions in which the eta is not being observed. 7 refs., 8 figs

  2. Evidence for a periaqueductal gray-nucleus retroambiguus spinal cord pathway in the rat

    Holstege, G.; Kerstens, Lenka; Moes, M.C.; Horst, V.G.J.M. van der

    1997-01-01

    The nucleus retroambiguus in the cat has been shown to receive strong projections from the periaqueductal gray and to send fibres to distinct motoneuronal cell groups in brainstem and spinal cord. The nucleus retroambiguus plays a role in the production of vocalization and possibly copulatory (lordo

  3. High plasma triglyceride levels strongly correlate with low kisspeptin in the arcuate nucleus of male rats

    Overgaard, A; Axel, A M; Lie, M E;

    2015-01-01

    OBJECTIVE: It is well known that reproductive capacity is lower in obese individuals, but what mediators and signals are involved is unclear. Kisspeptin is a potent stimulator of GnRH release, and it has been suggested that kisspeptin neurons located in the arcuate nucleus transmit metabolic sign...... hypertriglyceridemia per se that is a detrimental factor for kisspeptin expression in the arcuate nucleus....

  4. The Foxb1-expressing neurons of the ventrolateral hypothalamic parvafox nucleus project to defensive circuits.

    Bilella, Alessandro; Alvarez-Bolado, Gonzalo; Celio, Marco R

    2016-10-15

    The parvafox nucleus is an elongated structure that is lodged within the ventrolateral hypothalamus and lies along the optic tract. It comprises axially located parvalbumin (Parv)-positive neurons and a peripheral cuff of Foxb1-expressing ones. In the present study, injections of Cre-dependent adenoviral constructs were targeted to the ventrolateral hypothalamus of Foxb1/Cre mice to label specifically and map the efferent connections of the Foxb1-expressing subpopulation of neurons of the parvafox nucleus. These neurons project more widely than do the Parv-positive ones and implicate a part of the axons known to emanate from the lateral hypothalamus. High labeling densities were found in the dorsolateral and the upper lateral portion of the periaqueductal gray (PAG), the Su3 and PV2 nuclei of the ventrolateral PAG, the cuneiform nucleus, the mesencephalic reticular formation, and the superior colliculus. Intermediate densities of terminals were encountered in the septum, bed nucleus of the stria terminalis, substantia innominata, various thalamic and hypothalamic nuclei, pedunculopontine nucleus, Barrington's nucleus, retrofacial nucleus, and retroambigual nucleus. Scattered terminals were observed in the olfactory bulbs, the prefrontal cortex and the lamina X of the cervical spinal cord. Because the terminals were demonstrated to express the glutamate transporter VGlut2, the projections are presumed to be excitatory. A common denominator of the main target sites of the Foxb1-positive axons of the parvafox nucleus appears to be an involvement in the defensive reactions to life-threatening situations. The hypothalamic parvafox nucleus may contribute to the autonomic manifestations that accompany the expression of emotions. J. Comp. Neurol. 524:2955-2981, 2016. © 2016 Wiley Periodicals, Inc. PMID:27292133

  5. Pion-nucleus scattering at around the DELTA (1232) resonance

    The pion-nucleus scattering around 200 MeV and just above 1200 MeV is dominated by strong, broad Δ (3,3) and weak resonances in the π±N interaction. The interaction to a first approximation can be described as diffraction process. Since it is well known that the strength of the π+N and π-N interactions are quite different from each other at the resonances, the analyses of differential cross section for π+N and π-N elastic scattering data in the region of low-lying pion-nucleus resonances will be a good test of different strengths. In the present work we analyze pions scattering from nuclei 9Be, 28Si, 58Ni, 89Y and 208Pb at incident pion energies between 50 and 291 MeV within the framework of the three parameter version of the Strong Absorption Model of Frahn and Venter. All the oscillations in the elastic scattering experimental data and for the experimental angular distribution leading to 2+ and 3- collective states could be well reproduced by the model. The best fit parameter values for T, Δ and μ are determined. They are respectively the cut-off angular momentum, rounding parameter and the real nuclear phase shift parameters of the model. The interaction radius 'R', the surface diffuseness 'd' and the reaction cross-section σr have been determined from the derived parameter values. The standard nuclear radius r0 and the surface diffuseness 'd' are fairly constant. The deformation parameters βL have been determined from the normalization constant of the theory to the experiment without making any change in the elastic scattering parameters. The β2 and β3 values so extracted are in good agreement with other works. It is observed that there is hardly any difference between the values of β2 (π+) and β2 (π-) and that between β3 (π+) and β3(π-) values. (author)

  6. The analysis of potential energy of fissionable nucleus of isotopes of uranium and plutonium induced by thermal neutrons

    Full text : At modeling process of fiss is a question on a configuration of a compound-nucleus in a scission point. But the form of a nucleus and the moment of scission are not experimentally observable quantities

  7. Local field corrections to the pion nucleus optical potential

    We present an evaluation of the local field corrections to the pion optical potential in nuclear matter. These corrections, which amount to include an infinite subset of rescattering terms in the π-nucleus optical potential, are shown to give an improved description of the coupling of the nuclear ground state to the 1p-1h, 2p-2h, ..., np-nh excited states. Furthermore it is shown that, if in the evaluation of these local field corrections, the nucleon pole in the P11 channel is correctly taken into account, one obtains a realistic description of true pion absorption processes with one, two or more nucleons knocked out. Numerical estimations of these corrections, incorporating nucleons Fermi motion, recoil corrections and correlations effects are presented. Their density, energy and momentum dependence is studied and the influence of different factors (correlation, π-nucleon range, recoil corrections) is investigated. Finally, these theoretical predictions are compared to the phenomenological values obtained by fit to the experimental data

  8. Deuterium target data for precision neutrino-nucleus cross sections

    Meyer, Aaron S.; Betancourt, Minerba; Gran, Richard; Hill, Richard J.

    2016-06-01

    Amplitudes derived from scattering data on elementary targets are basic inputs to neutrino-nucleus cross section predictions. A prominent example is the isovector axial nucleon form factor, FA(q2), which controls charged current signal processes at accelerator-based neutrino oscillation experiments. Previous extractions of FA from neutrino-deuteron scattering data rely on a dipole shape assumption that introduces an unquantified error. A new analysis of world data for neutrino-deuteron scattering is performed using a model-independent, and systematically improvable, representation of FA. A complete error budget for the nucleon isovector axial radius leads to rA2=0.46(22)fm2, with a much larger uncertainty than determined in the original analyses. The quasielastic neutrino-neutron cross section is determined as σ(νμn→μ-p)|Eν=1GeV=10.1(0.9)×10-39cm2. The propagation of nucleon-level constraints and uncertainties to nuclear cross sections is illustrated using MINERvA data and the GENIE event generator. These techniques can be readily extended to other amplitudes and processes.

  9. Morphological differences in the lateral geniculate nucleus associated with dyslexia

    Mónica Giraldo-Chica

    2015-01-01

    Full Text Available Developmental dyslexia is a common learning disability characterized by normal intelligence but difficulty in skills associated with reading, writing and spelling. One of the most prominent, albeit controversial, theories of dyslexia is the magnocellular theory, which suggests that malfunction of the magnocellular system in the brain is responsible for the behavioral deficits. We sought to test the basis of this theory by directly measuring the lateral geniculate nucleus (LGN, the only location in the brain where the magnocellular and parvocellular streams are spatially disjoint. Using high-resolution proton-density weighted MRI scans, we precisely measured the anatomical boundaries of the LGN in 13 subjects with dyslexia (five female and 13 controls (three female, all 22–26 years old. The left LGN was significantly smaller in volume in subjects with dyslexia and also differed in shape; no differences were observed in the right LGN. The functional significance of this asymmetry is unknown, but these results are consistent with the magnocellular theory and support theories of dyslexia that involve differences in the early visual system.

  10. The planetary nebula Abell 48 and its [WN4] nucleus

    Frew, David J; Parker, Q A; Stupar, M; Wachter, S; DePew, K; Danehkar, A; Fitzgerald, M F

    2013-01-01

    We have conducted a detailed multi-wavelength study of the peculiar planetary nebula Abell 48 and its central star. We present evidence for a new classification of the nucleus as a helium-rich, hydrogen-deficient star of type [WN4], one of only two currently known examples of its type. The evidence for either a massive WN or a low-mass [WN] interpretation is critically examined, and we firmly conclude that Abell 48 is a planetary nebula around an evolved low-mass star, rather than a Population I ejecta nebula. Importantly, the surrounding nebula has a morphology typical of planetary nebulae, and is not enriched in nitrogen, and thus not the 'peeled atmosphere' of a massive star. We estimate a distance of 1.6 kpc and a reddening, E(B-V) = 1.90 mag, the latter value clearly showing the nebula lies on the near side of the Galactic bar, and therefore cannot be a massive WN star. The planetary nebula has an ionized mass (0.3 M_sun) and electron density (740 cm^-3) typical of somewhat evolved objects. The observed ...

  11. Thermodynamic pathways to genome spatial organization in the cell nucleus.

    Nicodemi, Mario; Prisco, Antonella

    2009-03-18

    The architecture of the eukaryotic genome is characterized by a high degree of spatial organization. Chromosomes occupy preferred territories correlated to their state of activity and, yet, displace their genes to interact with remote sites in complex patterns requiring the orchestration of a huge number of DNA loci and molecular regulators. Far from random, this organization serves crucial functional purposes, but its governing principles remain elusive. By computer simulations of a statistical mechanics model, we show how architectural patterns spontaneously arise from the physical interaction between soluble binding molecules and chromosomes via collective thermodynamics mechanisms. Chromosomes colocalize, loops and territories form, and find their relative positions as stable thermodynamic states. These are selected by thermodynamic switches, which are regulated by concentrations/affinity of soluble mediators and by number/location of their attachment sites along chromosomes. Our thermodynamic switch model of nuclear architecture, thus, explains on quantitative grounds how well-known cell strategies of upregulation of DNA binding proteins or modification of chromatin structure can dynamically shape the organization of the nucleus. PMID:19289043

  12. Comparative study of alpha + nucleus elastic scattering using different models

    The alpha (α) elastic scattering from different targets potential over the energy range 10–240 MeV has been analyzed in the framework of the single-folding (SF) optical model. Four targets are considered, namely, 24Mg, 28Si, 32S and 40Ca. The SF calculations for the real central part of the nuclear optical potential are performed by folding an effective α–α interaction with the α-cluster distribution density in the target nucleus. The imaginary part of the optical potential is expressed in the phenomenological Woods–Saxon (WS) form. The calculated angular distributions of the elastic scattering differential cross-section using the derived semimicroscopic potentials successfully reproduce 36 sets of data all over the measured angular ranges. The obtained results confirm the validity of the α-cluster structure of the considered nuclei. For the sake of comparison, the same sets of data are reanalyzed using microscopic double-folded optical potentials based upon the density-dependent Jeukenne–Lejeune–Mahaux (JLM) effective nucleon–nucleon interaction. (author)

  13. Paraventricular Nucleus Modulates Excitatory Cardiovascular Reflexes during Electroacupuncture.

    Tjen-A-Looi, Stephanie C; Guo, Zhi-Ling; Fu, Liang-Wu; Longhurst, John C

    2016-01-01

    The paraventricular nucleus (PVN) regulates sympathetic outflow and blood pressure. Somatic afferent stimulation activates neurons in the hypothalamic PVN. Parvocellular PVN neurons project to sympathoexcitatory cardiovascular regions of the rostral ventrolateral medulla (rVLM). Electroacupuncture (EA) stimulates the median nerve (P5-P6) to modulate sympathoexcitatory responses. We hypothesized that the PVN and its projections to the rVLM participate in the EA-modulation of sympathoexcitatory cardiovascular responses. Cats were anesthetized and ventilated. Heart rate and mean blood pressure were monitored. Application of bradykinin every 10-min on the gallbladder induced consistent pressor reflex responses. Thirty-min of bilateral EA stimulation at acupoints P5-P6 reduced the pressor responses for at least 60-min. Inhibition of the PVN with naloxone reversed the EA-inhibition. Responses of cardiovascular barosensitive rVLM neurons evoked by splanchnic nerve stimulation were reduced by EA and then restored with opioid receptor blockade in the PVN. EA at P5-P6 decreased splanchnic evoked activity of cardiovascular barosensitive PVN neurons that also project directly to the rVLM. PVN neurons labeled with retrograde tracer from rVLM were co-labeled with μ-opioid receptors and juxtaposed to endorphinergic fibers. Thus, the PVN and its projection to rVLM are important in processing acupuncture modulation of elevated blood pressure responses through a PVN opioid mechanism. PMID:27181844

  14. Elastic and inelastic scattering of neutrons on 238U nucleus

    Capote R.

    2014-04-01

    Full Text Available Advanced modelling of neutron induced reactions on the 238U nucleus is aimed at improving our knowledge of neutron scattering. Capture and fission channels are well constrained by available experimental data and neutron standard evaluation. A focus of this contribution is on elastic and inelastic scattering cross sections. The employed nuclear reaction model includes – a new rotational-vibrational dispersive optical model potential coupling the low-lying collective bands of vibrational character observed in even-even actinides; – the Engelbrecht-Weidenmüller transformation allowing for inclusion of compound-direct interference effects; – and a multi-humped fission barrier with absorption in the secondary well described within the optical model for fission. Impact of the advanced modelling on elastic and inelastic scattering cross sections including angular distributions and emission spectra is assessed both by comparison with selected microscopic experimental data and integral criticality benchmarks including measured reaction rates (e.g. JEMIMA, FLAPTOP and BIG TEN. Benchmark calculations provided feedback to improve the reaction modelling. Improvement of existing libraries will be discussed.

  15. Tryptophan synthase of Phaeophyceae originated from the secondary host nucleus

    ZHANG Yalan; CHI Shan; WU Shuangxiu; LIU Cui; YU Jun; WANG Xumin; CHEN Shengping; LIU Tao

    2014-01-01

    Tryptophan synthase (TS, EC 4.2.1.20) catalyzes the last two steps of L-tryptophan biosynthesis. In pro-karyotes, tryptophan synthase is a multi-enzyme complex, and it consists ofαandβsubunit which forms anα-ββ-αcomplex. In fungi and diatoms, TS is a bifunctional enzyme. Because of the limited genomic and transcriptomic data of algae, there are few studies on TS evolution of algae. Here we analyzed the data of the 1000 Plants Project (1KP), and focused on red algae and brown algae. We found out that the TS of Phaeophy-ceae were fusion genes, which probably originated from the secondary host nucleus, and that the TS of Rho-dophyta contained two genes, TSA and TSB, which both display a possible cyanobacterial origin at the time of primary endosymbiosis. In addition, there were two types of TSB genes (TSB1 and TSB2). Through the multiple sequence alignment of TSB proteins, we found several residues conserved in TSB1 but variable in TSB2 which connect withαsubunit. The phenomenon may suggest that the TSB2 sequences of Rhodophyta cannot form stable complex with TSA.

  16. GABA in Paraventricular Nucleus Regulates Adipose Afferent Reflex in Rats.

    Lei Ding

    Full Text Available Chemical stimulation of white adipose tissue (WAT induces adipose afferent reflex (AAR, and thereby causes a general sympathetic activation. Paraventricular nucleus (PVN is important in control of sympathetic outflow. This study was designed to investigate the role of γ-aminobutyric acid (GABA in PVN in regulating the AAR.Experiments were carried out in anesthetized rats. Renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP were continuously recorded. AAR was evaluated by the RSNA and MAP responses to electrical stimulation of the right epididymal WAT (eWAT afferent nerve. Electrical stimulation of eWAT afferent nerve increase RSNA. Bilateral microinjection of the GABAA receptor agonist isoguvacine or the GABAB receptor agonist baclofen attenuated the AAR. The effect of isoguvacine on the AAR was greater than that of baclofen. The GABAA receptor antagonist gabazine enhanced the AAR, while the GABAB receptor antagonist CGP-35348 had no significant effect on the AAR. Bilateral PVN microinjection of vigabatrin, a selective GABA-transaminase inhibitor, to increase endogenous GABA levels in the PVN abolished the AAR. The inhibitory effect of vigabatrin on the AAR was attenuated by the pretreatment with gabazine or CGP-35348. Pretreatment with combined gabazine and CGP-35348 abolished the effects of vigabatrin.Activation of GABAA or GABAB receptors in the PVN inhibits the AAR. Blockade of GABAA receptors in the PVN enhances the AAR. Endogenous GABA in the PVN plays an important role in regulating the AAR.

  17. Associated charm production in neutrino-nucleus interactions

    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)/σNCDIS=(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 νμ 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-)/σCC-4. (orig.)

  18. The Subthalamic Nucleus, Limbic Function, and Impulse Control.

    Rossi, P Justin; Gunduz, Aysegul; Okun, Michael S

    2015-12-01

    It has been well documented that deep brain stimulation (DBS) of the subthalamic nucleus (STN) to address some of the disabling motor symptoms of Parkinson's disease (PD) can evoke unintended effects, especially on non-motor behavior. This observation has catalyzed more than a decade of research concentrated on establishing trends and identifying potential mechanisms for these non-motor effects. While many issues remain unresolved, the collective result of many research studies and clinical observations has been a general recognition of the role of the STN in mediating limbic function. In particular, the STN has been implicated in impulse control and the related construct of valence processing. A better understanding of STN involvement in these phenomena could have important implications for treating impulse control disorders (ICDs). ICDs affect up to 40% of PD patients on dopamine agonist therapy and approximately 15% of PD patients overall. ICDs have been reported to be associated with STN DBS. In this paper we will focus on impulse control and review pre-clinical, clinical, behavioral, imaging, and electrophysiological studies pertaining to the limbic function of the STN. PMID:26577509

  19. GUSTATORY RESPONSES OF NEURONS IN THE PARABRACHIAL NUCLEUS OF RATS

    黄涛; 闫剑群; 康怡

    2002-01-01

    Objective To investigate the gustatory neural r esponse of the neurons to five basic taste stimuli in the parabrachial nucleus ( PBN). Methods Evoked responses from PBN taste neurons to t astants were recorded using standard extracellular microelectrode technique. Results 46 taste neurons were recorded in PBN, and most of th em were broadly respo nsive. On the basis of their most effective taste stimuli, these taste neurons w ere classified into five types. Those are NaCl-, HCl-, quinine-, sucrose-, and monosodium glutamate (MSG)-best neurons. Except for the quinine-best neur ons, the responses of each best-stimulus category to its best stimulus were sig nificantly stronger than those of others (P<0.01). The results of correlati on analysis showed that the correlations between sucrose and each of the other 4 tastants were smaller than those among others. Conclusion Th e results suggest that PBN taste neurons probably play an important role in disc riminating for hedonic taste.

  20. GUSTATORY RESPONSES OF NEURONS IN THE PARABRACHIAL NUCLEUS OF RATS

    2002-01-01

    Objective:To investigate the gustatory neural response of the neurons to five basic taste stimuli in the parabrachial nucleus(PBN),Methods:Evoked responses from PBN taste neurons to tastants were recorded using standard extracellular microelectrode technique.Results:46 taste neurons were recorded in PBN,and most of them were broadly responsive.On the basis of their most effective taste stimuli,these taste neurons were classified into five types.Those are NaCl-,HCl-,quinine-sucrose-,and monosodium glutamate(MSG)-best neurons.Except for the quinine-best neurons,the responses of each best-stimulus category to its best stimulus were significantly stronger than those of others(P<0.01),The results of correlation analysis showed that the correlations between sucrose and each of the other 4 tastants were smaller than those among others.Conclusion:The results suggest that PBN taste neurons probably play an important role in discriminating for hedonic taste.