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Fil: Rodrigues Ferreira Maltez, Dario Pablo. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina. Comision Nacional de Energia Atomica. Gerencia del Area de Investigacion y Aplicaciones No Nucleares. Gerencia Fisica (Centro Atomico Constituyentes). Proyecto Tandar; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisica; Argentina

Excited states up to I π = 8 + in the neutron-rich nucleus 58Cr have been identified by using a new experimental setup composed of the large acceptance magnetic spectrometer PRISMA and the highly efficient γ-detector array CLARA. Interestingly, the excitation energy sequence of the ground-state band follows the one expected by the E ( 5 ) dynamical symmetry for a nucleus at the critical point of the shape phase transition from a spherical vibrator ( U ( 5 ) ) to a γ-soft rotor ( O ( 6 ) ). For the first time, in the same physical system, large scale shell-model calculations in the full fp shell are compared to the E ( 5 ) analytical model results and to the Interacting Boson Model. The theoretical results are in excellent agreement with the present data.

PRISMA is a magnetic spectrometer installed at Laboratori Nazionali di Legnaro (Italy) and designed for A=100– 200, E=5– 10 MeV-per-nucleon beams, and for possible use with the proposed radioactive beam facility SPES. The foremost features of the instrument are presented, along with the outline of two data analyses exemplifying the effectiveness of PRISMA-CLARA in studies of reaction dynamics.

This work was partially supported by the European Community FP6, Structuring the ERA Integrated Infrastructure Initiative Contract No. EURONS RII3-CT-2004-506065, by MICINN, Spain (Contract No. FPA2011-29854), by IN2P3, France (Contract No. AIC-D-2011-648), by Comunidad de Madrid, Spain (Contract No. HEPHACOS S2009-ESP-1473), and by Generalitat Valenciana, Spain (Contract No. PROMETEO/ 2010/101). A. Gadea and E. Farnea acknowledge the support of MICINN, Spain, and INFN, Italy, through the AIC-D-2011-0746 bilateral action

Neutron-rich Co isotopes from N = 34 to 40 were studied through multinucleon transfer by bombarding a 238U target with a 460 MeV 70Zn beam at LNL. Gamma-recoil coincidences were recorded identifying the ions by a high-acceptance magnetic spectrometer (PRISMA) and detecting the gamma radiation by an array of HPGe clover detectors (CLARA). The results are discussed in comparison with the predictions of large-scale shell-model calculations.

We have investigated the age-dependent profile of two groups of NMDAR1 mRNA isoforms, the NR1(0)XX and the NR1(1)XX, which are characterized by the absence and the presence, respectively, of an N-terminal positioned 21 amino acid insert. mRNAs of the two spliced variants were investigated at different ages in discrete rat brain areas by means of the reverse transcription-polymerase chain reaction. The existence of regional variations was confirmed as well as a region-specific pattern of NR1(0)XX/1XX ratio and its age-dependent changes. At 6 months, the ratio was > 3 in prosencephalic structures and < 1 in metencephalic regions. The greatest age-related changes were found in the cerebellum that switched from a maximal ratio of 5.1 +/- 0.4 at day 6 through a progressive decay down to the value of 0.3 +/- 0.04 at 24 months. Age-dependent changes of the different NR1 spliced variant mRNAs are relevant to understand possible regulatory mechanisms of the pharmacological properties and functions of different NMDAR subtypes.

This work was supported by the Italian Istituto Nazionale di Fisica Nucleare and partially by the Spanish MICINN (ACI2009-1070 bilateral action) and Generalitat Valenciana (Grant Nos. BEST/2009/073 and PROMETEO/2010/101). The work has also been partially supported by the Polish Ministry of Science and Higher Education (Grant No. N N202 309135).

The population and gamma decay of neutron rich nuclei around 48Ca has been measured at Legnaro National Laboratory with the PRISMA-CLARA setup, using deep-inelastic collisions (DIC) on 64Ni, at an energy approximately twice the Coulomb barrier. The reaction properties of the main products are investigated, focusing on total cross sections and angular distributions both integrated in energy and associated to the population of specific excited states. Gamma spectroscopy studies are also performed, giving evidence, for the first time in transfer reactions with heavy ions, of a large spin alignment (~70%), perpendicular to the reaction plane. This makes possible the use of angular distributions and polarization measurements to firmly establish the spin and parity of excited states populated in nucleon transfer channels, as in the case of 49Ca, where candidates for particle-core coupling are investigated. Both reaction and gamma spectroscopy studies demonstrate the relevance of DIC with heavy ions for a detailed investigation of moderately neutron rich systems.

The deep inelastic reaction (DIC) 48Ca+64Ni, at an energy approximately 2.5 times above the Coulomb barrier, was studied using the CLARA‐PRISMA setup at the Laboratori Nazionali di Legnaro. Total cross sections and angular distributions, both energy integrated and associated to the population of selected excited states, are measured for the most intense reaction channels. The γ‐decay of the most intense reaction products is also studied. The use of angular distributions and polarization measurements of γ transitions allows to firmly establish spin and parity of excited states. Both reaction and gamma spectroscopy studies demonstrate the relevance of DIC with heavy ions for the investigation of moderately neutron rich systems.

The nucleus ${}^{46}$Ti has been studied with the reaction ${}^{42}$Ca(${}^{7}$Li,$p$2n)${}^{46}$Ti at a bombarding energy of 31 MeV. Thin target foils backed with a thick Au layer were used. Five new levels of negative parity were observed. Several lifetimes have been determined with the Doppler shift attenuation method. Low-lying experimental negative-parity levels are assigned to three bands with ${K}^{\ensuremath{\pi}}={3}^{\ensuremath{-}}$, ${0}^{\ensuremath{-}}$, and ${4}^{\ensuremath{-}}$, which are interpreted in terms of the large-scale shell model, considering particle-hole excitations from ${d}_{3/2}$ and ${s}_{1/2}$ orbitals. Shell model calculations were performed using a few effective interactions. However, good agreement was not achieved in the description of either negative- or positive-parity low-lying levels.

To investigate the possible X(5) character of {sup 122}Ba, suggested by the ground-state band energy pattern, the lifetimes of the lowest yrast states of {sup 122}Ba have been measured, via the recoil distance Doppler-shift method. The relevant levels have been populated by using the {sup 108}Cd({sup 16}O,2n){sup 122}Ba and the {sup 112}Sn({sup 13}C,3n){sup 122}Ba reactions. The B(E2) values deduced in the present work are compared to the predictions of the X(5) model and to calculations performed in the framework of the IBA-1 and IBA-2 models.

Excited states in the N=30 neutron-rich isotope {sup 49}K have been studied using multinucleon transfer reactions with thin targets and the PRISMA-CLARA spectrometer combined with thick-target {gamma}-coincidence data from Gammasphere. The d{sub 3/2} proton-hole state is located 92 keV above the s{sub 1/2} ground state, and the proton-particle f{sub 7/2} state is suggested at 2104 keV. Three other levels are established as involving the coupling to 2{sup +} of two neutrons above the N=28 shell. The measured or estimated lifetimes served to reinforce the interpretation of the observed level structure, which is found to be in satisfactory agreement with shell-model calculations.

The $g$ factors of the ${12}^{+}$, ${11}^{\ensuremath{-}}$, and ${8}^{\ensuremath{-}}$ isomeric states in $^{188}\mathrm{Pb}$ were measured using the time-differential perturbed angular distribution method as $g({12}^{+})=\ensuremath{-}0.179(6)$, $g({11}^{\ensuremath{-}})=+1.03(3)$, and $g({8}^{\ensuremath{-}})=\ensuremath{-}0.037(7)$. The $g$ factor of the ${12}^{+}$ state follows the observed slight down-sloping evolution of the $g$ factors of the ${i}_{13/2}^{2}$ neutron spherical states with decreasing $N$. The $g$ factors of the ${11}^{\ensuremath{-}}$ and ${8}^{\ensuremath{-}}$ isomers proposed as oblate and prolate deformed states, respectively, were interpreted within the rotational model, using calculated and empirical $g$ factor values for the involved single-particle orbitals.

The structure of the $N=20$ nucleus $^{37}\mathrm{Cl}$ has been investigated in the $^{24}\mathrm{Mg}(^{16}\mathrm{O},3p)$ reaction with a 70 MeV $^{16}\mathrm{O}$ beam. A complex level scheme extended up to an excitation energy of 17 MeV and spins ($29/{2}^{+}$) and ($27/{2}^{\ensuremath{-}}$) on positive and negative parity, respectively, has been established. Lifetimes for the new states have been investigated by the Doppler shift attenuation method. Large-scale shell-model calculations have been performed in a valence space involving orbitals in the $\mathit{sd}$ and $\mathit{fp}$ shells using the $\mathit{sdfp}$ and SDPF-M effective interactions. The comparison with the experimental data indicates the need for slight changes of the $\mathit{sd}\text{\ensuremath{-}}\mathit{fp}$ energy gaps produced by these interactions.

Isospin symmetry breaking has been investigated in mass A=67 mirror nuclei through the experimental determination of the E1 strengths of analog electromagnetic transitions. Lifetimes of excited states have been measured in (67)Se and (67)As with the centroid shift method. Through the comparison of the B(E1) strengths of the mirror 9/2(+)--7/2(-) transitions, the isovector and the isoscalar components of the electromagnetic transition amplitude were extracted. The presence of a large isoscalar component provides evidence for coherent contributions to isospin mixing, probably involving the isovector giant monopole resonance.

This work focus on the electromagnetic decay properties of the heaviest known mirror pair 67As and 67Se, produced in the fusion evaporation reaction 32S+40Ca, with a E = 90 MeV beam provided by the ATLAS accelerator at Argonne National Laboratory. The high selectivity required to investigate these proton‐rich nuclei was achieved with the concurrent employment of Gammasphere, Neutron‐Shell, and Microball. The full array allowed to obtain the level scheme of the 67Se nucleus up to 5.56 MeV, and 5 new transitions were assigned to the known 67As level‐scheme. The level spin and parities were assigned using the ADO analysis and symmetry arguments.

The lifetimes of excited states of the 122Ba ground—state band, populated via the 108Cd(16O,2n)122Ba and the 112Sn(13C,2n)122Ba reactions, have been measured using the Recoil Distance Doppler—Shift method. The level scheme of 122Ba has also been revised.

The reaction 48Ca+64Ni has been studied in the deep inelastic regime at approximately 6 MeV/A, by the CLARA‐PRISMA setup. Angular distributions of the reaction cross sections have been obtained for the most intense reaction products, taking into account the response function of the magnetic spectrometer. The response of PRISMA has been calculated making use of a MonteCarlo simulation of the transport of the ions in the spectrometer, starting from known events distributions. For the one‐nucleon transfer channels, the experimental data are in good agreement with predictions from a semiclassical multi‐nucleon transfer model.

Valiente-Dobon, J. J. Lenzi, S. M. Freeman, S. J. Lunardi, S. Smith, J. F. Gottardo, A. Della Vedova, F. Farnea, E. Gadea, A. Napoli, D. R. Axiotis, M. Aydin, S. Bazzacco, D. Bizzeti, P. G. Bizzeti-Sona, A. M. Benzoni, G. Bucurescu, D. Corradi, L. Deacon, A. N. de Angelis, G. Fioretto, E. Guiot, B. Ionescu-Bujor, M. Iordachescu, A. Leoni, S. Marginean, N. Marginean, R. Mason, P. Menegazzo, R. Mengoni, D. Million, B. Montagnoli, G. Orlandi, R. Recchia, F. Sahin, E. Scarlassara, F. Singh, R. P. Stefanini, A. M. Steppenbeck, D. Szilner, S. Ur, C. A. Varley, B. J. Wieland, O.

The low-lying yrast states in the {sup 51}Ca and {sup 52}Sc nuclei were investigated to obtain information on the evolution of the p{sub 1/2} and f{sub 5/2} neutron single-particle orbitals in neutron-rich nuclei near proton number Z=20. Level structures associated with neutron excitations into these two orbitals and with proton excitations across the Z=20 shell gap were identified. Shell-model calculations with the recently proposed GXPF1A interaction account reasonably well for the fp-shell states. The energy separation between the {nu}p{sub 1/2} and {nu}f{sub 5/2} orbitals in the Ca isotopes appears to be overestimated by the GXPF1A Hamiltonian.

The ^{24}Mg + ^{24}Mg reaction has been studied at the Legnaro Tandem at a CM bombarding energy of 45.7 MeV where a narrow and high spin resonance has been reported previously. The decay of the resonance into the inelastic and fusion–evaporation channels has been investigated. The ON and OFF resonance decay yields have been measured using, for the inelastic channels, the fragment spectrometer PRISMA and the γ array CLARA, and, for the fusion–evaporation channels, the Si array EUCLIDES and the γ array GASP. Strong resonant effects have been observed in the inelastic channels involving the 2_1^+ and 4_1^+ states of the ^{24}Mg ground state band. Weaker effects are also seen in certain fusion–evaporation channels. The properties of the studied resonance are in agreement with molecular model predictions. It is also proposed that the narrow and high spin ^{24}Mg + ^{24}Mg resonance corresponds to the formation of a fast rotating and highly prolate deformed ^{48}Cr after a Jacobi shape transition and just before fission.

The positive-parity yrast states in the ^{89}Rb, ^{92}Y, and ^{93}Y nuclei were studied using $\gamma$-ray spectroscopy with heavy-ion induced reactions. In the multinucleon transfer reactions ^{208}Pb+^{90}Zr (590 MeV) and ^{238}U+^{82}Se (505 MeV), several $\gamma$-ray transitions were identified in these nuclei by means of coincidences between recoiling ions identified with the PRISMA spectrometer and $\gamma$ rays detected with the CLARA $\gamma$-ray array in thin target experiments. Level schemes were subsequently determined from triple- $\gamma$ coincidences recorded with the GASP array in a thick target experiment, in the reactions produced by a 470 MeV ^{82}Se beam with a ^{192}Os target. The observed level schemes are compared to shell-model calculations.

Lunardi, S. Lenzi, S. M. Della Vedova, F. Farnea, E. Gadea, A. Marginean, N. Bazzacco, D. Beghini, S. Bizzeti, P. G. Bizzeti-Sona, A. M. Bucurescu, D. Corradi, L. Deacon, A. N. de Angelis, G. Fioretto, E. Freeman, S. J. Ionescu-Bujor, M. Iordachescu, A. Mason, P. Mengoni, D. Montagnoli, G. Napoli, D. R. Nowacki, F. Orlandi, R. Pollarolo, G. Recchia, F. Scarlassara, F. Smith, J. F. Stefanini, A. M. Szilner, S. Ur, C. A. Valiente-Dobon, J. J. Varley, B. J.

High-spin states in $^{35}\mathrm{Ar}$ and $^{35}\mathrm{Cl}$ have been populated in the $^{24}\mathrm{Mg}$($^{16}\mathrm{O}$, $\ensuremath{\alpha}n$) and $^{24}\mathrm{Mg}$($^{16}\mathrm{O}$, $\ensuremath{\alpha}p$) reactions, respectively, at a beam energy of 70 MeV. The comparison between the level schemes of these mirror nuclei shows a striking asymmetry in the population yield of high-spin analog states of positive parity, which indicates different intensities of $E1$ transitions connecting positive- and negative-parity structures in both nuclei. Large energy differences are observed between analog states of negative parity with configurations of dominant pure single-particle character. This results from the comparison with large-scale shell-model calculations in the ${s}_{1/2}{d}_{3/2}{f}_{7/2}{p}_{3/2}$ valence space. It is shown that important contributions to the energy differences arise from the multipole Coulomb and the relativistic electromagnetic spin-orbit interactions.

Lifetimes of exited states in $^{134}$Pr were measured by means of the recoil distance Doppler-shift and Doppler-shift attenuation techniques. The branching ratios and the electric or magnetic character of the transitions were also investigated. The experiments were performed at IReS, Strasbourg, using the EUROBALL IV spectrometer, in conjunction with the inner bismuth germanate ball and the Cologne coincidence plunger apparatus. Exited states in $^{134}$Pr were populated in the fusion-evaporation reaction $^{119}Sn(^{19}F, 4n)^{134}$Pr. The possible chiral interpretation of twin bands was investigated in the two-quasiparticle triaxial rotor and interacting boson-fermion-fermion models. The analysis of the wave functions has shown that the possibility for the angular momenta of the proton, neutron, and core to find themselves in the favorable, almost orthogonal geometry, is present but is far from being dominant. The structure is characterized by large $\beta$ and $\gamma$ fluctuations. The existence of doublets of bands in $^{134}$Pr can be attributed to weak chirality dominated by shape fluctuations.

By comparing the excitation energies of analogue states in isobaric multiplets, several nuclear structure properties can be studied as a function of the angular momentum up to high spin states. In particular, the mirror nuclei 35Ar and 35Cl show large differences between the excitation energies of analogue negative‐parity states at high spin, confirming the important contribution of the relativistic electromagnetic spin‐orbit interaction to the Coulomb energy. The single‐particle character of the configuration of these states is reproduced with very good accuracy by shell model calculations in the sd and pf shells valence space. In addition, evidence of isospin mixing is deduced from the El transitions linking positive and negative parity states.

Multinucleon transfer reactions in 40Ca+96Zr and 90Zr+208Pb have been measured at energies close to the Coulomb barrier in a high resolution gamma-particle coincidence experiment. The large solid angle magnetic spectrometer PRISMA coupled to the CLARA gamma-array has been employed. Trajectory reconstruction has been applied for the complete identification of transfer products. Mass and charge yields, total kinetic energy losses, gamma transitions of the binary reaction partners, and comparison of data with semiclassical calculations are reported. Specific transitions in 95Zr populated in one particle transfer channels are discussed in terms of particle-phonon couplings. The gamma decays from states in 42Ca in the excitation energy region expected from pairing vibrations are also observed., Comment: 10 pages, 9 figures

The nucleus 37Ar has been studied with γ‐ray spectroscopy in the 24Mg(16O,2pn) reaction at a beam energy of 70 MeV. Twenty two new excited states up to an excitation energy of 13 MeV have been observed. We compare the first negative and positive parity yrast states with large‐scale‐shell‐model calculations using the Antoine code and the SDPF interaction, considering the excitation of the 1d5/2,2s1/2 and 1d3/2 nucleons to 1f7/2 and 2p3/2 in the sdpf valence space.

In a recent experiment at Argonne National Laboratory, new spectroscopic information was obtained for the mirror pair 67As and 67Se via the measurement of the lifetime of analogue 9/2I+ excited states. The nuclei of interest were populated via the fusion evaporation reaction of 32S on 40Ca, and selected by the combination of Gammasphere, Microball and the Neutron Wall arrays. The mirror B(E1) strengths were measured via the centroid shift method in analogue E1 transitions in 67As and 67Se. These findings are significant in determining the extent of conservation of isospin symmetry.

The PRISMA‐CLARA setup, consisting of the large solid angle magnetic spectrometer for heavy‐ions PRISMA coupled to the highly efficient CLARA array of 25 Clovers detectors, was operating at LNL since the end of 2003. The first experimental campaign has been completed at the end of 2004. Selected results on the structure of moderately neutron‐rich nuclei, populated in multi‐nucleon transfer and deep‐inelastic reactions, are presented here. Some technical developments related to the setup are also discussed.

The nucleus $^{31}\mathrm{P}$ has been studied in the $^{24}\mathrm{Mg}$($^{16}\mathrm{O}$,2$\ensuremath{\alpha}p$) reaction with a 70-MeV $^{16}\mathrm{O}$ beam. A complex level scheme extended up to spins 17/2${}^{+}$ and 15/2${}^{\ensuremath{-}}$, on positive and negative parity, respectively, has been established. Lifetimes for the new states have been investigated by the Doppler shift attenuation method. Two shell-model calculations have been performed to describe the experimental data, one by using the code ANTOINE in a valence space restricted to the sd shell, and the other by applying the Monte Carlo shell model in a valence space including the $\mathit{sd}\text{\ensuremath{-}}\mathit{fp}$ shells. The latter calculation indicates that intruder excitations, involving the promotion of a $T=0$ proton-neutron pair to the fp shell, play a dominant role in the structure of the positive-parity high-spin states of $^{31}\mathrm{P}$.

The CLARA-PRISMA setup is a powerful tool for spectroscopic studies of neutron-rich nuclei produced in multi-nucleon transfer and deep-inelastic reactions. It combines the large acceptance spectrometer PRISMA with the gamma-ray array CLARA. At present, the ancillary heavy-ion detector DANTE, based on Micro-Channel Plates to be installed at the CLARA-PRISMA setup, is being constructed at LNL. DANTE will open the possibility of measuring gamma-gamma-Doppler-corrected coincidences for the events outside the acceptance of PRISMA. In this presentation, it is described the heavy-ion detector DANTE, as well as the performances of the first prototype.

The fusion-evaporation reactions Si-28(S-32,1 alpha 2p1n)Fe-53 at 125 MeV and Mg-24(S-32,2p1n)Fe-53 at a 95-MeV beam energy were used to investigate excited states in Fe-53. The combination of the Gammasphere Ge detector array and ancillary devices led to the construction of an extensive level scheme comprising some 90 transitions connecting 40 states. The lifetime of the yrast 25/2(-) state and upper limits for the lifetimes of a number of additional states were determined using the Cologne plunger device coupled to the GASP gamma-ray spectrometer. The experimental results are compared to large-scale shell-model calculations using different sets of two-body matrix elements. In particular, predictions on electromagnetic decay properties such as lifetimes, branching ratios, and mixing ratios are studied in detail. (Less)

The nucleus {sup 34}S has been studied up to relatively high spin (I=10({Dirac_h}/2{pi})) and up to an excitation energy of 16.64 MeV. Data are compared with different shell model calculations where effective interactions involving two main shells, the sd and the fp, are used. For the first time in an N{ne}Z nucleus, it is observed that the promotion of an isoscalar (T=0) proton-neutron pair to the fp shell becomes energetically favored at high spin.

CLARA is an array of 25 Clover (EUROBALL type) Ge detectors, placed at the target position of the large acceptance magnetic spectrometer PRISMA. Due to the granularity of the CLARA Ge array (100 crystals), the photopeak efficiency ($\approx$3%) and the PRISMA large acceptance ($\approx$80 msr, and 20% $\Delta$p/p), the setup is an excellent tool to investigate the structure of neutron-rich nuclei, populated in multinucleon transfer reactions and deep inelastic collisions with stable beams. Since March 2004 the setup is fully operational, and since then several experiments have been performed, with beams delivered by the LNL XTU-Tandem and the ALPI linac. In this contribution the preliminary outcome of the first experiments is shown.

High‐energy γ rays emitted in the symmetric reaction 90Zr + 89Y have been measured at the Argonne National Laboratory using the LEPPEX array coupled to the Fragment Mass Analyzer (FMA). The high‐energy γ‐ray spectra emitted by the giant dipole resonance built on excited states and associated with the evaporation of 0, 1 and 2 nucleons have been measured. The statistical model analysis indicates that the radiative‐fusion process, namely the 0 particle emission channel, can be well described as a compound nucleus decay channel. In addition, the analysis of the high‐energy γ‐ray spectra associated with the different evaporation channels provides the first evidence that shell effects still play a role in determining the nuclear shapes of 179Au in the temperature interval 0.5–1 MeV.

Amyloidosis is defined as the cascade of structural changes of proteins leading to the formation of insoluble fibril aggregates that accumulate in tissue as amyloid plaques. All types of amyloidosis are structurally characterized by the cross β-pleated sheet conformation of the fibrils irrespective of their biochemical composition (reviewed by Glenner, 1980). This common structural feature of fibril aggregates is the basis of their insolubility and relative resistance to proteolytic digestion (Jarrett and Lansbury, 1993; Nordstedt et al., 1994). Amyloid plaque formation and deposition is believed to be the key event in nerve cell death in chronic and incurable neurodegenerative diseases such as Alzheimer’s Disease (AD) (reviewed by Scikoe, 1996) and Creutzfeldt-Jakob Disease (CJD) (reviewed by Prusiner, 1996). One of the major therapeutic approaches to arrest, or at least slow down the progression of these devastating diseases, is to stop proteins from aggregating into amyloid fibrils.

Several lines of evidence suggest that N-methyl-D-aspartate (NMDA) receptors significantly contribute to the development of kindling. In addition, a lasting enhancement of the NMDA receptor function has been suggested to play a significant role in the chronic hyperexcitability occurring in the hippocampus after kindling epileptogenesis. We have investigated whether hippocampal kindling induces changes in the NMDA receptor at the molecular level by assessing the expression of mRNAs of the different spliced variants at the N-terminal (exon 5) and C-terminal (exon 21) position of the NMDA receptor 1 (NR1) gene by means of the reverse transcription-polymerase chain reaction. Alternative splicing at exon 5 confers different sensitivity of the NMDA receptor to polyamines while exon 21 encodes a 37-amino acid insert containing the major phosphorylation sites for protein kinase C. One week after the acquisition of stage 5 of kindling in rats (generalized tonic-clonic seizures), the relative abundance of the two alternatively spliced forms at the C-terminal domain, respectively containing (+) or lacking (-) exon 21, was reversed compared to controls (implanted with electrodes but not stimulated) in the dorsal hippocampus ipsilateral and contralateral to the electrical stimulation. The exon 21+/exon 21- mRNA ratio for controls was 1.3 +/- 0.04 (mean +/- SE); for ipsilaterally kindled rats it was 0.64 +/- 0.05 (P < 0.05), and for contralaterally kindled rats it was 0.48 +/- 0.07 (P < 0.01). Similar bilateral effects were observed in the ventral hippocampus (temporal pole). No changes were found 4 weeks after stage 5 seizures and 1 week after the induction of a single afterdischarge. No significant alterations were induced by kindling in the relative abundance of the spliced variants containing or lacking exon 5. Our findings show selective changes in alternative splicing of the NR1 gene after repeated application of an epileptogenic stimulus. This may generate receptors with different functional properties, which may contribute to the increased sensitivity for the induction of generalized seizures during kindling.

Neutron-rich Co isotopes from N = 34 to 40 were studied through multinucleon transfer by bombarding a 238U target with a 460 MeV 70Zn beam at the Legnaro National Laboratories. Gamma-recoil coincidences were recorded identifying the ions by using a high-acceptance magnetic spectrometer (PRISMA) and detecting the gamma radiation by using an array of HPGe clover detectors (CLARA). The results are discussed in comparison with the predictions of large-scale shell-model calculations.

Using the 20Ne + 12C fusion-evaporation reaction at E20Ne = 33 MeV and the multidetector array GASP in conjuction with the EUCLIDES charged particle detector, angular correlations of coincident pairs of γ transitions and lifetimes in mirror nuclei 31S and 31P have been measured at the Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro. A comparison of the determined B(E1) strengths of the analog mirror 7/2− → 5/2+ transitions indicates the presence of a violation of isospin symmetry.

The daily urinary excretion of salsolinol, 1,2-dehydrosalsolinol, and norsalsolinol, as free, glucuronide, and sulfate, has been measured in parkinsonian patients and age-matched controls in an attempt to examine whether the determination of dopamine-derived alkaloids in urine may be used as a marker of the decrease in brain dopamine levels associated with the disease. In contrast with a preliminary study where the daily urinary excretion of total salsolinol was significantly higher in young controls than in parkinsonians, in the present study no difference was found between parkinsonian patients and controls concerning salsolinol and norsalsolinol excretion. However, the urinary excretion of total 1,2-dehydrosalsolinol was significantly higher in the control group, owing to a statistically significant increase in its excretion as sulfate in this group. Further studies appear to be necessary to establish whether 1,2-dehydrosalsolinol, salsolinol, and/or any other dopamine-derived alkaloid may serve for the detection of subjects with dysfunctions of the dopaminergic system.

Age-related reduction in the steady-state levels of messenger RNA for D2415 and D2444, the alternatively spliced form of dopamine D2 receptors, was observed in different rat brain areas using the sensitive reserve transcription (RT)-polymerase chain reaction (PCR) technique. In both Sprague-Dawley and Wistar aged rats, the decrease was more pronounced in the D2434 isoform mRNA thus leading to a changed ratio in striatum as well as in the hyppocampus.

Prion diseases are marked by the cerebral accumulation of conformationally modified forms of the cellular prion protein (PrPC), known as PrPres. The region comprising the residues 106-126 of human PrP seems to have a key role in this conformational conversion, because a synthetic peptide homologous with this sequence (PrP106-126) adopts different secondary structures in different environments. To investigate the molecular determinants of the physicochemical characteristics of PrP106-126, we synthesized a series of analogues including PrP106-126 HD, PrP106-126 A and PrP106-126 K, with L-His → D-His, His → Ala and His → Lys substitutions respectively at position 111, PrP106-126 NH2 with amidation of the C-terminus, PrP106-126 V with an Ala → Val substition at position 117, and PrP106-126 VNH2 with an Ala → Val substitution at position 117 and amidation of the C-terminus. The analysis of the secondary structure and aggregation properties of PrP106-126 and its analogues showed the following. (1) His111 is central to the conformational changes of PrP peptides. (2) Amidation of the C-terminal Gly126 yields a predominantly random coil structure, abolishes the molecular polymorphism and decreases the propensity of PrP106-126 to generate amyloid fibrils. (3) PrP106-126 V, carrying an Ala → Val substitution at position 117, does not demonstrate a fibrillogenic ability superior to that of PrP106-126. However, the presence of Val at position 117 increases the aggregation properties of the amidated peptide. (4) Amyloid fibrils are not required for neurotoxicity because the effects of PrP106-126 NH2 on primary neuronal cultures were similar to those of the wild-type sequence. Conversely, astroglial proliferation is related to the presence of amyloid fibrils, suggesting that astrogliosis in prion encephalopathies without amyloid deposits is a mediated effect rather than a direct effect of disease-specific PrP isoforms.

The spectra of high-energy γ rays emitted by the Giant Dipole Resonance (GDR) built on moderately excited states associated with the evaporation of 0, 1 and 2 nucleons were measured in the 90 Zr + 89 Y symmetric fusion reaction. The radiative fusion data suggest statistical emission from the compound nucleus. In addition, the analysis of the high-energy γ -ray spectra associated with the different evaporation channels at the present temperature of 0.7 MeV and spin range 15–20 ¯ h show a fairly narrow width of 5.0 ± 0.35 MeV. This value is smaller than what would be expected in a nucleus where shell effects do not play a role.  2003 Published by Elsevier Science B.V.

Neutron rich nuclei around 48Ca have been measured with the CLARA–PRISMA setup, making use of 48Ca on 64Ni binary reactions, at 5.9 MeV/A. Angular distributions of γ rays give evidence, in several transfer channels, for a large spin alignment (≈70%) perpendicular to the reaction plane, making it possible to firmly establish spin and parities of the excited states. In the case of 49Ca, states arising from different types of particle–core couplings are, for the first time, unambiguously identified on basis of angular distribution, polarization and lifetime measurements. Shell model and particle–vibration coupling calculations are used to pin down the nature of the states. Evidence is found for the presence, in the same excitation energy region, of two types of coupled states, i.e. single particle coupled to either 48Ca or 50Ca simple configurations, and particle–vibration coupled states based on the 3− phonon of 48Ca., This work was supported by the Italian Istituto Nazionale di Fisica Nucleare and partially by the Spanish MICINN (ACI2009-1070 bilateral action) and Generalitat Valenciana (Grant Nos. BEST/2009/073 and PROMETEO/2010/101). The work has also been partially supported by the Polish Ministry of Science and Higher Education (Grant No. N N202 309135).