RELATIVISTIC THEORY OF SPECTRAL CHARACTERISTICS OF PIONIC ATOMIC SYSTEMS: APPLICATION TO HEAVY SYSTEMS

A new theoretical approach to energy and spectral parameters of the hadronic (pionic and kaonic) atoms in the excited states with precise accounting for the relativistic, radiation and nuclear effects is presented. There are presented data of calculation of the energy and spectral parameters for pionic atoms of the 93Nb, 173Yb, 181Ta , 197Au, with accounting for the radiation (vacuum polarization), nuclear (finite size of a nucleus ) and the strong pion-nuclear interaction corrections. The measured values of the Berkley, CERN and Virginia laboratories and alternative data based on other versions of the Klein-Gordon-Fock theories with taking into account for a finite size of the nucleus in the model uniformly charged sphere and the standard Uhling-Serber potential approach for account for the radiation corrections are listed too.

NEW RELATIVISTIC APPROACH TO COMPUTING SPECTRAL PARAMETERS OF MULTICHARGED IONS IN PLASMAS

It is presented a new relativistic approach to computing the spectral parameters of multicharged ions in plasmas for different values of the plasmas screening (Debye) parameter (respectively, electron density, temperature). The approach used is based on the generalized relativistic energy approach combined with the optimized relativistic many-body perturbation theory (RMBPT) with the Dirac-Debye shielding model as zeroth approximation, adapted for application to study the spectral parameters of ions in plasmas. An electronic Hamiltonian for N-electron ion in plasmas is added by the Yukawa-type electron-electron and nuclear interaction potential. The special exchange potential as well as the electron density with dependence upon the temperature are used.

Quantitative measure of the isospin splitting of the effective nucleon mass

The effective nucleon mass splits into two components, one for the proton and another for the neutron, in the case of adding the isovector coupling channel of the nuclear interaction, while being the same in the case of considering only the isoscalar coupling. A quantitative measure of the splitting is defined by the root mean square (RMS) value of the effective nucleon mass splitting and applied to the effective nucleon mass splitting in lead and tin isotopes. The isospin splitting of the effective nucleon mass is found to increase almost linearly with the asymmetry parameter.

Nucleon-nucleus inelastic scattering by Manning-Rosen distorted nonlocal potential

Within the framework of non-relativistic quantum scattering theory we treat the charged hadron scattering by replacing the nuclear interaction by a separable nonlocal one and the electromagnetic part by the Manning-Rosen potential. The off-energy-shell scattering is studied by this additive interaction by including the effect of electromagnetic interaction rigorously. The exact analytical expressions for the off-shell solutions and half-shell T-matrix are obtained in maximal reduced form. The half-shell T-matrix for the proton-oxygen system is computed and the resultant phase shifts are found in order.

Reconstruction of solar activity based on 14C and other isotope profiles in lunar regolith

The Moon might be considered as an integral detector of Galactic Cosmic Rays (GCR) as it contains on its surface cosmogenic isotopes produced by nuclear reactions. Since the retrieval of lunar regolith cores by Apollo missions, there were numerous attempts to measure concentrations and depth profiles of those isotopes and reconstruct the level of cosmic radiation at 1AU at various time scales, ranging from thousands to millions of years. The data also contains encoded levels of solar activity, as the Sun affects the differential flux of GCRs in a well-known manner. All those attempts showed that our nuclear interaction codes, GEANT4 for example, need corrections to describe the lunar data, be it tweaking of cross-sections or any other methods. There are also such archives on Earth: ice cores and trees. Based on terrestrial modulation potential reconstruction we try to calibrate GEANT4 code in a transparent manner, and also present our estimates on the solar activity on time scales of 0.02 and 3 Myrs. The estimates made using our calibration procedure show values consistent with modern understanding of history of solar modulation potential, and demonstrate the necessity to establish an agreed correction method for the analysis of lunar data. We also compare our results and method with another estimation of solar modulation potential during the last 1 Myr.

Significant Parent-of-Origin Effects for Seed, Cotyledon, and Early Plant Growth Traits in Cucumber

Parent-of-origin effects have long been recognized and exploited in plant breeding and genetic studies. These effects can be conferred by preferential expression of an allele from one parent, organellar effects, or altered organellar-nuclear interaction. The goal of this work was to evaluate parent-of-origin effects on seed, cotyledon, and early growth traits in cucumber using a full eight-by-eight diallel from crossing two doubled haploids (DHs) extracted from each of four cucumber populations. Significant general combining ability (GCA), specific combining ability (SCA), and reciprocal effects were observed for all traits, and direction and magnitude of effects were DH rather than population specific. Transcriptome analyses of reciprocal hybrids with and without significant reciprocal effects for early plant growth revealed that different pathways were associated with the significant reciprocal differences. These findings are consistent with the DH-specific nature of combining abilities and reciprocal effects across cucumber populations. Because reciprocal effects were DH and hybrid-combination specific, cucumber breeders should generate and evaluate both hybrids from reciprocal crossing for improved hybrid development.

Unified Equation of State for Neutron Stars Based on the Gogny Interaction

The effective Gogny interactions of the D1 family were established by D. Gogny more than forty years ago with the aim to describe simultaneously the mean field and the pairing field corresponding to the nuclear interaction. The most popular Gogny parametrizations, namely D1S, D1N and D1M, describe accurately the ground-state properties of spherical and deformed finite nuclei all across the mass table obtained with Hartree–Fock–Bogoliubov (HFB) calculations. However, these forces produce a rather soft equation of state (EoS) in neutron matter, which leads to predict maximum masses of neutron stars well below the observed value of two solar masses. To remove this limitation, we built new Gogny parametrizations by modifying the density dependence of the symmetry energy predicted by the force in such a way that they can be applied to the neutron star domain and can also reproduce the properties of finite nuclei as good as their predecessors. These new parametrizations allow us to obtain stiffer EoS’s based on the Gogny interactions, which predict maximum masses of neutron stars around two solar masses. Moreover, other global properties of the star, such as the moment of inertia and the tidal deformability, are in harmony with those obtained with other well tested EoSs based on the SLy4 Skyrme force or the Barcelona–Catania–Paris–Madrid (BCPM) energy density functional. Properties of the core-crust transition predicted by these Gogny EoSs are also analyzed. Using these new Gogny forces, the EoS in the inner crust is obtained with the Wigner–Seitz approximation in the Variational Wigner–Kirkwood approach along with the Strutinsky integral method, which allows one to estimate in a perturbative way the proton shell and pairing corrections. For the outer crust, the EoS is determined basically by the nuclear masses, which are taken from the experiments, wherever they are available, or by HFB calculations performed with these new forces if the experimental masses are not known.

Cleavage and activation of LIM kinase 1 as a novel mechanism for calpain 2-mediated regulation of nuclear dynamics

Calpain-2 (CAPN2) is a processing enzyme ubiquitously expressed in mammalian tissues whose pleiotropic functions depend on the role played by its cleaved-products. Nuclear interaction networks, crucial for a number of molecular processes, could be modified by CAPN2 activity. However, CAPN2 functions in cell nucleus are poorly understood. To unveil CAPN2 functions in this compartment, the result of CAPN2-mediated interactions in cell nuclei was studied in breast cancer cell (BCC) lines. CAPN2 abundance was found to be determinant for its nucleolar localization during interphase. Those CAPN2-dependent components of nucleolar proteome, including the actin-severing protein cofilin-1 (CFL1), were identified by proteomic approaches. CAPN2 binding, cleavage and activation of LIM Kinase-1 (LIMK1), followed by CFL1 phosphorylation was studied. Upon CAPN2-depletion, full-length LIMK1 levels increased and CFL1/LIMK1 binding was inhibited. In addition, LIMK1 accumulated at the cell periphery and perinucleolar region and, the mitosis-specific increase of CFL1 phosphorylation and localization was altered, leading to aberrant mitosis and cell multinucleation. These findings uncover a mechanism for the role of CAPN2 during mitosis, unveil the critical role of CAPN2 in the interactions among nuclear components and, identifying LIMK1 as a new CAPN2-target, provide a novel mechanism for LIMK1 activation. CFL1 is crucial for cytoskeleton remodeling and mitosis, but also for the maintenance of nuclear structure, the movement of chromosomes and the modulation of transcription frequently altered in cancer cells. Consequently, the role of CAPN2 in the nuclear compartment might be extended to other actin-associated biological and pathological processes.

Remarkable Properties of Isotope Effect

Present paper is devoted to the non - accelerator manifestation of the strong nuclear interaction - the heart of quantum chromodynamics (QCD) which is part of the Standard Model (SM). The observation of isotopic shift (0.103 eV) of the zero - phonon emission line in photoluminescence spectra of LiD crystals (possessing a strict interaction in the deuterium nucleus) comparison with LiH (in the hydrogen nucleus of which there is no strong interaction) is a first direct proof of the strong nuclear long - range character. The non - accelerating measurement of the strong interaction constant from the distance between nucleons made it possible to find the maximum possible value of αs = 2.4680. The isotopic acquisition of mass by massless fermions is briefly discussed

James Philip Elliott. 27 July 1929—21 October 2008

James Philip Elliott made important contributions to improve our understanding of the structure of atomic nuclei in the second half of the twentieth century. In 1958 he proposed the SU(3) model, explaining rotational behaviour of nuclei in the context of the shell model. His idea, based on elegant and seminal group-theoretical concepts, reconciled the independent-particle with the liquid-drop model, which until then existed as disconnected views of the nucleus. In the 1960s and 1970s he developed methods to extract properties of the nuclear interaction from the phase shifts of nucleon–nucleon scattering. From 1980 until his death he contributed to the development of the interacting boson model of Arima and Iachello, and its microscopic understanding in terms of symmetries of the shell model. For his outstanding achievements in theoretical physics, in 2002 he and Francesco Iachello were awarded the Lise Meitner prize of the European Physical Society for ‘their innovative applications of group-theoretical methods to the understanding of atomic nuclei’. His achievements were also recognized by the award of the Rutherford Medal and Prize of the Institute of Physics in 1994.