WorldWideScience

Sample records for complex nuclear decay

  1. Mapping Nuclear Decay to Complex Network

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Network model is always a key topic in the research of network science. Large Unifying Hybrid Network (LUHNM) theory, which we proposed before, is a universal network model that can be used to depict the diversity and complexity of the natural network.

  2. $\\Delta$ decay in nuclear medium

    CERN Document Server

    Jain, B K; Kundu, Bijoy

    1996-01-01

    Proton-nucleus collisions, where the beam proton gets excited to the delta resonance and then decays to p\\pi ^+, either inside or outside the nuclear medium, are studied. Cross-sections for various kinematics for the (p,p' \\pi ^+) reaction between 500 MeV and 1 GeV beam energy are calculated to see the effects of the nuclear medium on the propagation and decay of the resonance. The cross-sections studied include proton energy spectra in coincidence with the pion, four momentum transfer distributions, and the invariant p\\pi^+ mass distributions. We find that the effect of the nuclear medium on these cross-sections mainly reduces their magnitudes. Comparing these cross-sections with those considering the decay of the delta outside the nucleus only, we further find that at 500 MeV the two sets of cross-sections have large differences, while by 1 GeV the differences between them become much smaller.

  3. Power Spectrum Analyses of Nuclear Decay Rates

    CERN Document Server

    Javorsek, D; Lasenby, R N; Lasenby, A N; Buncher, J B; Fischbach, E; Gruenwald, J T; Hoft, A W; Horan, T J; Jenkins, J H; Kerford, J L; Lee, R H; Longman, A; Mattes, J J; Morreale, B L; Morris, D B; Mudry, R N; Newport, J R; O'Keefe, D; Petrelli, M A; Silver, M A; Stewart, C A; Terry, B; 10.1016/j.astropartphys.2010.06.011

    2010-01-01

    We provide the results from a spectral analysis of nuclear decay data displaying annually varying periodic fluctuations. The analyzed data were obtained from three distinct data sets: 32Si and 36Cl decays reported by an experiment performed at the Brookhaven National Laboratory (BNL), 56Mn decay reported by the Children's Nutrition Research Center (CNRC), but also performed at BNL, and 226Ra decay reported by an experiment performed at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. All three data sets exhibit the same primary frequency mode consisting of an annual period. Additional spectral comparisons of the data to local ambient temperature, atmospheric pressure, relative humidity, Earth-Sun distance, and their reciprocals were performed. No common phases were found between the factors investigated and those exhibited by the nuclear decay data. This suggests that either a combination of factors was responsible, or that, if it was a single factor, its effects on the decay rate experiments are n...

  4. An analytical method for estimating the 14N nuclear quadrupole resonance parameters of organic compounds with complex free induction decays for radiation effects studies

    Energy Technology Data Exchange (ETDEWEB)

    Iselin, Louis Henry [Univ. of Florida, Gainesville, FL (United States)

    1992-01-01

    The use of 14N nuclear quadrupole resonance (NQR) as a radiation dosimetry tool has only recently been explored. An analytical method for analyzing 14N NQR complex free induction decays is presented with the background necessary to conduct pulsed NQR experiments. The 14N NQR energy levels and possible transitions are derived in step-by-step detail. The components of a pulsed NQR spectrometer are discussed along with the experimental techniques for conducting radiation effects experiments using the spectrometer. Three data analysis techniques -- the power spectral density Fourier transform, state space singular value decomposition (HSVD), and nonlinear curve fitting (using the downhill simplex method of global optimization and the Levenberg-Marquart method) -- are explained. These three techniques are integrated into an analytical method which uses these numerical techniques in this order to determine the physical NQR parameters. Sample data sets of urea and guanidine sulfate data are used to demonstrate how these methods can be employed to analyze both simple and complex free induction decays. By determining baseline values for biologically significant organics, radiation effects on the NQR parameters can be studied to provide a link between current radiation dosimetry techniques and the biological effects of radiation.

  5. Radioactive decays at limits of nuclear stability

    DEFF Research Database (Denmark)

    Pfützner, M.; Karny, M.; Grigorenko, L. V.

    2012-01-01

    , and their relative probabilities. When approaching limits of nuclear stability, new decay modes set in. First, beta decays are accompanied by emission of nucleons from highly excited states of daughter nuclei. Second, when the nucleon separation energy becomes negative, nucleons start being emitted from the ground...

  6. Nuclear beta decay with Lorentz violation

    NARCIS (Netherlands)

    Noordmans, J.P.; Wilschut, H. W.; Timmermans, R. G. E.

    2013-01-01

    We consider the possibility of Lorentz-invariance violation in weak-decay processes. We present a general approach that entails modifying the W-boson propagator by adding a Lorentz-violating tensor to it. We describe the effects of Lorentz violation on nuclear beta decay in this scenario. In

  7. Helicity and nuclear $\\beta$ decay correlations

    CERN Document Server

    Hong, Ran; García, Alejandro

    2016-01-01

    We present simple derivations of nuclear $\\beta$-decay correlations with an emphasis on the special role of helicity. This provides a good opportunity to teach students about helicity and chirality in particle physics through exercises using simple aspects of quantum mechanics. In addition, this paper serves as an introduction to nuclear $\\beta$-decay correlations from both a theoretical and experimental vantage. This article can be used to introduce students to ongoing experiments searching for hints of new physics in the low-energy precision frontier.

  8. Helicity and nuclear β decay correlations

    Science.gov (United States)

    Hong, Ran; Sternberg, Matthew G.; Garcia, Alejandro

    2017-01-01

    We present simple derivations of nuclear β-decay correlations with an emphasis on the special role of helicity. This topic provides a good opportunity to teach students about helicity and chirality in particle physics with exercises that use simple aspects of quantum mechanics. In addition, this paper serves as an introduction to nuclear β-decay correlations from both a theoretical and experimental perspective. This article can be used to introduce students to ongoing experiments searching for hints of new physics in the low-energy precision frontier.

  9. Threedimensional dynamics of nuclear decay modes

    Science.gov (United States)

    Mirea, M.; Poenaru, D. N.; Greiner, W.

    1994-03-01

    We study nondissipative fission dynamics in a wide range of mass asymmetry, covering three groups of nuclear decay modes: cluster radioactivities; alpha-decay and cold fission. The WKB action integral is calculated by using the Werner-Wheeler inertia tensor and the deformation energy within Yukawa-plus-exponential model extended to binary systems with different charge densities. The optimum dynamical trajectory in a threedimensional deformation space (elongation, necking-in and mass-asymmetry) is determined by solving a nonlinear system of differential equations. This new method is illustrated for three decay modes of234U: α-decay, Mg-radioactivity and cold fission with100Zr as a light fragment.

  10. Detecting Double Beta Decays Using Nuclear Emulsions

    CERN Document Server

    Dracos, Marcos

    2008-01-01

    Neutrino nature and absolute mass scale are major questions in particle physics which cannot be addressed by the present neutrino oscillation program. To answer these two questions, several neutrinoless double beta decay experiments are underway or planed for the near future. These experiments, mainly use bolometric techniques or gaseous counters coupled with scintillator detectors. The energy resolution is better in bolometric experiments but experiments coupling tracking with calorimetry have the advantage of observing the two electron tracks and remove many background sources. Here, we present a proposal of using nuclear emulsions to observe double beta decays. This technique has the advantage of precise tracking and vertexing even for low energy electrons.

  11. Radioactive decays at limits of nuclear stability

    DEFF Research Database (Denmark)

    Pfützner, M.; Karny, M.; Grigorenko, L. V.

    2012-01-01

    The last decades brought impressive progress in synthesizing and studying properties of nuclides located very far from the beta stability line. Among the most fundamental properties of such exotic nuclides, the ones usually established first are the half-life, possible radioactive decay modes...... description of the most recently discovered and most complex radioactive process—the two-proton radioactivity—is discussed in more detail....

  12. Genome-Wide Mapping of Uncapped and Cleaved Transcripts Reveals a Role for the Nuclear mRNA Cap-Binding Complex in Cotranslational RNA Decay in Arabidopsis[OPEN

    Science.gov (United States)

    Willmann, Matthew R.

    2016-01-01

    RNA turnover is necessary for controlling proper mRNA levels posttranscriptionally. In general, RNA degradation is via exoribonucleases that degrade RNA either from the 5′ end to the 3′ end, such as XRN4, or in the opposite direction by the multisubunit exosome complex. Here, we use genome-wide mapping of uncapped and cleaved transcripts to reveal the global landscape of cotranslational mRNA decay in the Arabidopsis thaliana transcriptome. We found that this process leaves a clear three nucleotide periodicity in open reading frames. This pattern of cotranslational degradation is especially evident near the ends of open reading frames, where we observe accumulation of cleavage events focused 16 to 17 nucleotides upstream of the stop codon because of ribosomal pausing during translation termination. Following treatment of Arabidopsis plants with the translation inhibitor cycloheximide, cleavage events accumulate 13 to 14 nucleotides upstream of the start codon where initiating ribosomes have been stalled with these sequences in their P site. Further analysis in xrn4 mutant plants indicates that cotranslational RNA decay is XRN4 dependent. Additionally, studies in plants lacking CAP BINDING PROTEIN80/ABA HYPERSENSITIVE1, the largest subunit of the nuclear mRNA cap binding complex, reveal a role for this protein in cotranslational decay. In total, our results demonstrate the global prevalence and features of cotranslational RNA decay in a plant transcriptome. PMID:27758893

  13. Imperfect World of $\\beta\\beta$-decay Nuclear Data Sets

    CERN Document Server

    Pritychenko, B

    2015-01-01

    The precision of double-beta ($\\beta\\beta$) decay experimental half lives and their uncertainties is reanalyzed. The method of Benford's distributions has been applied to nuclear reaction, structure and decay data sets. First-digit distribution trend for $\\beta\\beta$-decay T$_{1/2}^{2\

  14. Decay Data Evaluation Project: Evaluation of (52)Fe nuclear decay data.

    Science.gov (United States)

    Luca, Aurelian

    2016-03-01

    Within the Decay Data Evaluation Project (DDEP) and the IAEA Coordinated Research Project no. F41029, the evaluation of the nuclear decay data of (52)Fe, a radionuclide of interest in nuclear medicine, was performed. The main nuclear decay data evaluated are: the half-life, decay energy, energies and probabilities of the electron capture and β(+) transitions, internal conversion coefficients and gamma-ray energies and emission intensities. This new evaluation, made using the DDEP methodology and tools, was included in the DDEP database NUCLEIDE.

  15. Statistical models for nuclear decay from evaporation to vaporization

    CERN Document Server

    Cole, A J

    2000-01-01

    Elements of equilibrium statistical mechanics: Introduction. Microstates and macrostates. Sub-systems and convolution. The Boltzmann distribution. Statistical mechanics and thermodynamics. The grand canonical ensemble. Equations of state for ideal and real gases. Pseudo-equilibrium. Statistical models of nuclear decay. Nuclear physics background: Introduction. Elements of the theory of nuclear reactions. Quantum mechanical description of scattering from a potential. Decay rates and widths. Level and state densities in atomic nuclei. Angular momentum in quantum mechanics. History of statistical

  16. Nuclear responses for neutrinos and neutrino studies by double beta decays and inverse beta decays

    Indian Academy of Sciences (India)

    H Ejiri

    2001-08-01

    This is a brief report on recent studies of nuclear responses for neutrinos () by charge exchange reactions, masses by double beta () decays and of solar and supernova ’s by inverse decays. Subjects discussed include (1) studies in nuclear micro-laboratories, (2) masses studied by decays of 100Mo and nuclear responses for -, (3) solar and supernova ’s by inverse decays and responses for 71Ga and 100Mo, and (4) MOON (molybdenum observatory of neutrinos) for spectroscopic studies of Majorana masses with sensitivity of ∼ 0.03 eV by decays of 100Mo and real-time studies of low energy solar and supernova ’s by inverse decays of 100Mo.

  17. The human nuclear poly(a-binding protein promotes RNA hyperadenylation and decay.

    Directory of Open Access Journals (Sweden)

    Stefan M Bresson

    Full Text Available Control of nuclear RNA stability is essential for proper gene expression, but the mechanisms governing RNA degradation in mammalian nuclei are poorly defined. In this study, we uncover a mammalian RNA decay pathway that depends on the nuclear poly(A-binding protein (PABPN1, the poly(A polymerases (PAPs, PAPα and PAPγ, and the exosome subunits RRP6 and DIS3. Using a targeted knockdown approach and nuclear RNA reporters, we show that PABPN1 and PAPα, redundantly with PAPγ, generate hyperadenylated decay substrates that are recognized by the exosome and degraded. Poly(A tail extension appears to be necessary for decay, as cordycepin treatment or point mutations in the PAP-stimulating domain of PABPN1 leads to the accumulation of stable transcripts with shorter poly(A tails than controls. Mechanistically, these data suggest that PABPN1-dependent promotion of PAP activity can stimulate nuclear RNA decay. Importantly, efficiently exported RNAs are unaffected by this decay pathway, supporting an mRNA quality control function for this pathway. Finally, analyses of both bulk poly(A tails and specific endogenous transcripts reveals that a subset of nuclear RNAs are hyperadenylated in a PABPN1-dependent fashion, and this hyperadenylation can be either uncoupled or coupled with decay. Our results highlight a complex relationship between PABPN1, PAPα/γ, and nuclear RNA decay, and we suggest that these activities may play broader roles in the regulation of human gene expression.

  18. Imperfect World of beta beta-decay Nuclear Data Sets

    Energy Technology Data Exchange (ETDEWEB)

    Pritychenko, B. [Brookhaven National Lab. (BNL), Upton, NY (United States). NNDC

    2015-01-03

    The precision of double-beta ββ-decay experimental half lives and their uncertainties is reanalyzed. The method of Benford's distributions has been applied to nuclear reaction, structure and decay data sets. First-digit distribution trend for ββ-decay T2v1/2 is consistent with large nuclear reaction and structure data sets and provides validation of experimental half-lives. A complementary analysis of the decay uncertainties indicates deficiencies due to small size of statistical samples, and incomplete collection of experimental information. Further experimental and theoretical efforts would lead toward more precise values of-decay half-lives and nuclear matrix elements.

  19. Data Calculation of X-Ray Arising From Nuclear Decay

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The x-ray data are relevant in nuclear decay data. In a gamma transition process, gamma transition energy will be transferred directly to an orbital electron in different atomic shells throughelectronic-magnetic interaction. The orbital electrons which have gotten transition energies overcomeatomic-electron binding energy and will emit out from different atomic shells, and leave vacancies. In an

  20. Nuclear Structure Studies from Hg and Au Alpha Decay Chains

    Science.gov (United States)

    Goon, J. Tm.; Bingham, C. R.; Hartley, D. J.; Zhang, Jing-Ye; Riedinger, L. L.; Danchev, M.; Kondev, F. G.; Carpenter, M. P.; Janssens, R. V. F.; Abu Saleem, K. H.; Ahmad, I.; Davids, C. N.; Heinz, A.; Khoo, T. L.; Lauritsen, T.; Lister, C. J.; Poli, G. L.; Seweryniak, D.; Wiedenhover, I.; Ma, W. C.; Amro, H.; Reviol, W.; Cizewski, J. A.; Smith, M.

    2003-04-01

    Neutron deficient nuclei near the Z = 82 shell gap have been a source of great interest. This region is known to exhibit the phenomena of shape-coexistence and triaxiality. Alpha decay study of these nuclei coupled with gamma-rayspectroscopy data can give a better understanding of their nuclear structure properties. The decay chains of ^173-177Au and ^175-179Hg were studied following the bombardment of ^92,94,96Mo targets with ^84Sr beam from the ATLAS accelerator at the Argonne National Laboratory. The experiment utilized the Gammasphere array in conjunction with the Fragment Mass Analyzer (FMA) for mass identification and a Double-sided Silicon Strip Detector (DSSD) that was used to detect the recoiling implants and the alpha particles associated with each nuclide. An array of four Ge detectors and a low-energy photon spectrometer (LEPS) was used at the focal plane of the FMA to detect γ rays in coincidence with the α particles. This information was used to elucidate the α-decay fine structures. Inverse radioactive decay tagging was also useful in assigning certain fine structure α peaks to a particular nuclide. New α decay lines were observed and their energies, and half-lives were measured. These include fine structure lines in the α decays of ^174,176Au and ^173Pt. The decay schemes resulting from the fine structure observations will be presented. The α decay reduced widths are used to suggest spin and parity assignments. The structure of these states will be discussed in the framework of the Nilsson model and alpha decay selection rules. * This work is supported by the Department of Energy through contract numbers DE-FG02-96ER40983 (UT), W-31-109-ENG-38 (ANL), DE-FG02-95ER40939 (MSU), DE-FG05-88ER40406 (WU), and by the National Science Foundation (RU

  1. Evidence against solar influence on nuclear decay constants

    Science.gov (United States)

    Pommé, S.; Stroh, H.; Paepen, J.; Van Ammel, R.; Marouli, M.; Altzitzoglou, T.; Hult, M.; Kossert, K.; Nähle, O.; Schrader, H.; Juget, F.; Bailat, C.; Nedjadi, Y.; Bochud, F.; Buchillier, T.; Michotte, C.; Courte, S.; van Rooy, M. W.; van Staden, M. J.; Lubbe, J.; Simpson, B. R. S.; Fazio, A.; De Felice, P.; Jackson, T. W.; Van Wyngaardt, W. M.; Reinhard, M. I.; Golya, J.; Bourke, S.; Roy, T.; Galea, R.; Keightley, J. D.; Ferreira, K. M.; Collins, S. M.; Ceccatelli, A.; Unterweger, M.; Fitzgerald, R.; Bergeron, D. E.; Pibida, L.; Verheyen, L.; Bruggeman, M.; Vodenik, B.; Korun, M.; Chisté, V.; Amiot, M.-N.

    2016-10-01

    The hypothesis that proximity to the Sun causes variation of decay constants at permille level has been tested and disproved. Repeated activity measurements of mono-radionuclide sources were performed over periods from 200 days up to four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and are attributable to instabilities in the instrumentation and measurement conditions. The most stable activity measurements of alpha, beta-minus, electron capture, and beta-plus decaying sources set an upper limit of 0.0006% to 0.008% to the amplitude of annual oscillations in the decay rate. Oscillations in phase with Earth's orbital distance to the Sun could not be observed within a 10-6 to 10-5 range of precision. There are also no apparent modulations over periods of weeks or months. Consequently, there is no indication of a natural impediment against sub-permille accuracy in half-life determinations, renormalisation of activity to a distant reference date, application of nuclear dating for archaeology, geo- and cosmochronology, nor in establishing the SI unit becquerel and seeking international equivalence of activity standards.

  2. Evidence against solar influence on nuclear decay constants

    Directory of Open Access Journals (Sweden)

    S. Pommé

    2016-10-01

    Full Text Available The hypothesis that proximity to the Sun causes variation of decay constants at permille level has been tested and disproved. Repeated activity measurements of mono-radionuclide sources were performed over periods from 200 days up to four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and are attributable to instabilities in the instrumentation and measurement conditions. The most stable activity measurements of alpha, beta-minus, electron capture, and beta-plus decaying sources set an upper limit of 0.0006% to 0.008% to the amplitude of annual oscillations in the decay rate. Oscillations in phase with Earth's orbital distance to the Sun could not be observed within a 10−6 to 10−5 range of precision. There are also no apparent modulations over periods of weeks or months. Consequently, there is no indication of a natural impediment against sub-permille accuracy in half-life determinations, renormalisation of activity to a distant reference date, application of nuclear dating for archaeology, geo- and cosmochronology, nor in establishing the SI unit becquerel and seeking international equivalence of activity standards.

  3. Radioactive decay as a forced nuclear chemical process: Phenomenology

    Science.gov (United States)

    Timashev, S. F.

    2015-11-01

    Concepts regarding the mechanism of radioactive decay of nuclei are developed on the basis of a hypothesis that there is a dynamic relationship between the electronic and nuclear subsystems of an atom, and that fluctuating initiating effects of the electronic subsystem on a nucleus are possible. Such relationship is reflected in experimental findings that show the radioactive decay of nuclei might be determined by a positive difference between the mass of an initial nucleus and the mass of an atom's electronic subsystem, i.e., the mass of the entire atom (rather than that of its nucleus) and the total mass of the decay products. It is established that an intermediate nucleus whose charge is lower by unity than the charge of the initial radioactive nucleus is formed as a result of the above fluctuating stimuli that initiate radioactive decay, and its nuclear matter is thus in an unbalanced metastable state of inner shakeup, affecting the quark subsystem of nucleons. The intermediate nucleus thus experiences radioactive decay with the emission of α or β particles. At the same time, the high energy (with respect to the chemical scale) of electrons in plasma served as a factor initiating the processes in different nuclear chemical transformations and radioactive decays in low-temperature plasma studied earlier, particularly during the laser ablation of metals in aqueous solutions of different compositions and in near-surface cathode layers upon glow discharge. It is shown that a wide variety of nucleosynthesis processes in the Universe can be understood on the same basis, and a great many questions regarding the formation of light elements in the solar atmosphere and some heavy elements (particularly p-nuclei) in the interiors of massive stars at late stages of their evolution can also be resolved.

  4. Nuclear decay data for radionuclides occurring in routine releases from nuclear fuel cycle facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kocher, D.C.

    1977-08-01

    This report gives tabulations of the atomic and nuclear radiations emitted by 240 radionuclides. Most of the radionuclides are those expected to occur in routine releases of effluents from nuclear fuel cycle facilities. For each radionuclide are given the half-life and recommended values for the energies, intensities, and equilibrium absorbed-dose constants for each of the atomic and nuclear radiations. Also given are the daughter radionuclides produced and recommended values for decay branching ratios, where applicable. The radioactivity decay chains and branching ratios are displayed in diagram form.

  5. Evaluation of the 125Sb nuclear decay data

    Science.gov (United States)

    Lile, Liu; Xiaolong, Huang; Mengxiao, Kang; Guochang, Chen; Jimin, Wang; Liyang, Jiang

    2016-02-01

    Evaluation of the complete decay scheme and data for 125Sb/125mTe decay to nuclear levels in 125Te is presented in this report; literature data available up to June 2015 are included. The Limitation of Relative Statistical Weight Method (LRSW) was applied to average numbers throughout the evaluation. The uncertainty assigned to the average value was always greater than or equal to the smallest uncertainty of the values used to calculate the average. The half-life has been determined to be 1007.4±0.3 days. All known measured γ-ray absolute or relative intensities have been examined; the γ-ray emission probability of the reference γ-ray line of 427.874 keV is recommended to be 29.54±0.10%. The theoretical internal conversion coefficients and their uncertainties were used to obtain the complete decay scheme intensity balance. The values of other decay characteristics were calculated using the ENSDF analysis program. Finally the updated decay scheme for 125Sb is presented.

  6. The rate of decay of fresh fission products from a nuclear reactor

    Science.gov (United States)

    Dolan, David J.

    Determining the rate of decay of fresh fission products from a nuclear reactor is complex because of the number of isotopes involved, different types of decay, half-lives of the isotopes, and some isotopes decay into other radioactive isotopes. Traditionally, a simplified rule of 7s and 10s is used to determine the dose rate from nuclear weapons and can be to estimate the dose rate from fresh fission products of a nuclear reactor. An experiment was designed to determine the dose rate with respect to time from fresh fission products of a nuclear reactor. The experiment exposed 0.5 grams of unenriched Uranium to a fast and thermal neutron flux from a TRIGA Research Reactor (Lakewood, CO) for ten minutes. The dose rate from the fission products was measured by four Mirion DMC 2000XB electronic personal dosimeters over a period of six days. The resulting dose rate following a rule of 10s: the dose rate of fresh fission products from a nuclear reactor decreases by a factor of 10 for every 10 units of time.

  7. Nuclear Structure aspects of gamma decay from giant resonances

    Directory of Open Access Journals (Sweden)

    Bracco A.

    2014-01-01

    Full Text Available The gamma decay of the giant dipole resonance (including its tail region is an important tool to probe the properties of these states, and thus to test the predictions of mean field theories. This paper focuses on two main aspects concerning the electric dipole excitation in nuclei. These are the study of the isospin character of the low energy tail of the Giant Dipole Resonance (GDR, the so-called Pygmy resonance, and the isospin mixing of nuclear systems at finite temperature. In the first case, the Pygmy resonance has been populated in the inelastic scattering reaction 17O+124Sn at 20 MeV/u. Its gamma decay has been measured using the AGATA Demonstrator and an array of 8 large volume LaBr3:Ce scintillators. In the second case, the gamma decay of the GDR in thermalized nuclear systems, formed in fusion evaporation reactions, has been used to investigate the isospin mixing in 80Zr. For this work the reactions 40Ca+40Ca at 3.4 MeV/u and 37Cl +44Ca at 2.6 MeV/u were used.

  8. Observation of exotic nuclear decay of 230U

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    230Pa was produced through the 232Th(p,3n)230Pa reaction in the irradiated ThO2 powder targets with 35 MeV proton beam. Pa was radiochemically separated from ThO2 and other reaction products, and then thin sources of 230Paβ-230U were prepared. The polyethylene-terephthalate (lavsan) films were selected as solid track detector searching for the cluster activity of 230U. The gamma activity of 230Pa in the sources was measured using a HPGe detector. The lavsan films were etched in NaOH solution and the etched films were scanned under an optical microscope. The exotic nuclear decay of 230U by emission of 22Ne was observed. A branching ratio relative to α decay was deduced, B =λNe/λα= (1.3±0.8)×10-14 for 22Ne emission from 230U.

  9. Nuclear Spin Echo Decay for the Walstedt-Cheong Mechanism

    Science.gov (United States)

    Coleman, Todd; Recchia, Charles; Seber, Derek; Pennington, Charles

    1997-03-01

    We present calculations of nuclear spin echo decay for the Walstedt-Cheong mechanism(R. E. Walstedt and S. -W. Cheong, Phys. Rev. B 51, 3163 (1995)) in which observed A nuclei are coupled to B nuclei that are experiencing magnetic spin lattice re laxation effects. It has been shown that this mechanism must be taken into account when NMR transverse relaxation rates are being analyzed to provide information on vortex dynamics and electronic spin susceptibility in cuprate superconductors.(R ecchia et al, submitted 1996) We report a method of computing spin echo decays which eliminates the need for numerical simulations and phase distribution approximations(C. H. Recchia, K. Gorny, and C. H. Pennington, Phys. Rev. B 54, 4207 (1996)) and involves the time evolution of normal modes of a relaxation matrix.

  10. Structure of nuclear transition matrix elements for neutrinoless double- decay

    Indian Academy of Sciences (India)

    P K Rath

    2010-08-01

    The structure of nuclear transition matrix elements (NTMEs) required for the study of neutrinoless double- decay within light Majorana neutrino mass mechanism is disassembled in the PHFB model. The NTMEs are calculated using a set of HFB intrinsic wave functions, the reliability of which has been previously established by obtaining an overall agreement between the theoretically calculated spectroscopic properties and the available experimental data. Presently, we study the role of short-range correlations, radial evolution of NTMEs and deformation effects due to quadrupolar correlations. In addition, limits on effective light neutrino mass $\\langle m_{} \\rangle$ are extracted from the observed limits on half-lives $T_{1/2}^{0}$ of neutrinoless double- decay.

  11. Superallowed nuclear beta decay: Precision measurements for basic physics

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, J. C. [Cylotron Institute, Texas A and M University, College station, TX, 77843-3366 (United States)

    2012-11-20

    For 60 years, superallowed 0{sup +}{yields}0{sup +} nuclear beta decay has been used to probe the weak interaction, currently verifying the conservation of the vector current (CVC) to high precision ({+-}0.01%) and anchoring the most demanding available test of the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix ({+-}0.06%), a fundamental pillar of the electroweak standard model. Each superallowed transition is characterized by its ft-value, a result obtained from three measured quantities: the total decay energy of the transition, its branching ratio, and the half-life of the parent state. Today's data set is composed of some 150 independent measurements of 13 separate superallowed transitions covering a wide range of parent nuclei from {sup 10}C to {sup 74}Rb. Excellent consistency among the average results for all 13 transitions - a prediction of CVC - also confirms the validity of the small transition-dependent theoretical corrections that have been applied to account for isospin symmetry breaking. With CVC consistency established, the value of the vector coupling constant, G{sub V}, has been extracted from the data and used to determine the top left element of the CKM matrix, V{sub ud}. With this result the top-row unitarity test of the CKM matrix yields the value 0.99995(61), a result that sets a tight limit on possible new physics beyond the standard model. To have any impact on these fundamental weak-interaction tests, any measurement must be made with a precision of 0.1% or better - a substantial experimental challenge well beyond the requirements of most nuclear physics measurements. I overview the current state of the field and outline some of the requirements that need to be met by experimentalists if they aim to make measurements with this high level of precision.

  12. Spectral decorrelation of nuclear levels in the presence of continuum decay

    CERN Document Server

    Trellakis, A

    1995-01-01

    The fluctuation properties of nuclear giant resonance spectra are studied in the presence of continuum decay. The subspace of quasi-bound states is specified by one-particle one-hole and two-particle two-hole excitations and the continuum coupling is generated by a scattering ensemble. It is found that, with increasing number of open channels, the real parts of the complex eigenvalues quickly decorrelate. This appears to be related to the transition from power-law to exponential time behavior of the survival probability of an initially non-stationary state.

  13. Beta-decay total absorption measurements for nuclear technology and astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Taina, J.L. [Instituto de Fisica Corpuscular, C.S.I.C.-U. Valencia (Spain)

    2008-07-01

    An accurate determination of the beta-decay intensity distribution is of importance for basic nuclear physics but also in the fields of reactor technology, astrophysics and fundamental interactions. Most of present information comes from experiments performed with high resolution low efficiency Ge {gamma}-ray spectroscopy, which fails to locate the beta intensity at high excitation energies in complex decays. The total absorption spectroscopy technique with large 4{pi} scintillation detectors can give the correct answer but requires an involved procedure in order to extract the information. Recent work on the systematization of the analysis methods and on the evaluation of the associated systematic uncertainties shows that reliable beta strength distributions can indeed be obtained. (author)

  14. Perforating the nuclear boundary - how nuclear pore complexes assemble.

    Science.gov (United States)

    Weberruss, Marion; Antonin, Wolfram

    2016-12-15

    The nucleus is enclosed by the nuclear envelope, a double membrane which creates a selective barrier between the cytoplasm and the nuclear interior. Its barrier and transport characteristics are determined by nuclear pore complexes (NPCs) that are embedded within the nuclear envelope, and control molecular exchange between the cytoplasm and nucleoplasm. In this Commentary, we discuss the biogenesis of these huge protein assemblies from approximately one thousand individual proteins. We will summarize current knowledge about distinct assembly modes in animal cells that are characteristic for different cell cycle phases and their regulation.

  15. Nuclear three-body problem in the complex energy plane: Complex-Scaling-Slater method

    CERN Document Server

    Kruppa, A T; Nazarewicz, W; Michel, N

    2013-01-01

    The physics of open quantum systems is an interdisciplinary area of research. The nuclear "openness" manifests itself through the presence of the many-body continuum representing various decay, scattering, and reaction channels. As the radioactive nuclear beam experimentation extends the known nuclear landscape towards the particle drip lines, the coupling to the continuum space becomes exceedingly more important. Of particular interest are weakly bound and unbound nuclear states appearing around particle thresholds. Theories of such nuclei must take into account their open quantum nature. To describe open quantum systems, we introduce a Complex Scaling (CS) approach in the Slater basis. We benchmark it with the complex-energy Gamow Shell Model (GSM) by studying energies and wave functions of the bound and unbound states of the two-neutron halo nucleus 6He viewed as an $\\alpha$+ n + n cluster system. In the CS approach, we use the Slater basis, which exhibits the correct asymptotic behavior at large distances...

  16. What do we know about neutrinoless double-beta decay nuclear matrix elements?

    CERN Document Server

    Menéndez, J

    2016-01-01

    The detection of neutrinoless double-beta decay will establish the Majorana nature of neutrinos. In addition, if the nuclear matrix elements of this process are reliably known, the experimental lifetime will provide precious information about the absolute neutrino masses and hierarchy. I review the status of nuclear structure calculations for neutrinoless double-beta decay matrix elements, and discuss some key issues to be addressed in order to meet the demand for accurate nuclear matrix elements.

  17. Nuclear emulsion with molybdenum filling for observation of $\\beta\\beta$ decay

    CERN Document Server

    Ashitkov, V D; Barabash, A S; Bradnova, V Ya; Chernyavsky, M M; Konovalov, S I; Okat'eva, N M; Orlova, G I; Polukhina, N G; Pozharova, E A; Smirnitsky, V A; Starkov, N I; Vladimirov, M S; Umatov, V I

    2010-01-01

    The usage of nuclear emulsion with molybdenum filling for observation of $\\beta\\beta$ decay are shown to be possible. Estimates for 1 kg of $^{100}$Mo with zero background give the sensitivity for the $0\

  18. Symmetry violations in nuclear and neutron beta decay

    NARCIS (Netherlands)

    Vos, K. K.; Wilschut, H. W.; Timmermans, R. G. E.

    2015-01-01

    The role of beta decay as a low-energy probe of physics beyond the standard model is reviewed. Traditional searches for deviations from the standard model structure of the weak interaction in beta decay are discussed in light of constraints from the Large Hadron Collider and the neutrino mass. Limit

  19. Alpha Decay in the Complex Energy Shell Model

    CERN Document Server

    Betan, R Id

    2012-01-01

    Alpha emission from a nucleus is a fundamental decay process in which the alpha particle formed inside the nucleus tunnels out through the potential barrier. We describe alpha decay of $^{212}$Po and $^{104}$Te by means of the configuration interaction approach. To compute the preformation factor and penetrability, we use the complex-energy shell model with a separable T=1 interaction. The single-particle space is expanded in a Woods-Saxon basis that consists of bound and unbound resonant states. Special attention is paid to the treatment of the norm kernel appearing in the definition of the formation amplitude that guarantees the normalization of the channel function. Without explicitly considering the alpha-cluster component in the wave function of the parent nucleus, we reproduce the experimental alpha-decay width of $^{212}$Po and predict an upper limit of T_{1/2}=5.5x10^{-7} sec for the half-life of $^{104}$Te. The complex-energy shell model in a large valence configuration space is capable of providing ...

  20. Radioactive decay by the emission of heavy nuclear fragments

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, O.A.P.; Roberto, L.A.M.; Medeiros, E.L. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mails: oaptavares@cbpf.br; emil@cbpf.br

    2007-07-01

    Radioactive decay of nuclei by the emission of heavy ions of C, N, O, F, Ne, Na, Mg, Al, Si, and P isotopes (known as exotic decay or cluster radioactivity) is reinvestigated within the framework of a semiempirical, one-parameter model based on a quantum mechanical, tunnelling mechanism through a potential barrier, where both centrifugal and overlapping effects are considered to half-life evaluations. This treatment appeared to be very adequate at fitting all measured half-life values for the cluster emission cases observed to date. Predictions for new heavy-ion decay cases susceptible of being detected are also reported. (author)

  1. Inhomogeneous dynamic nuclear polarization and suppression of electron polarization decay in a quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Na [Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); School of Physics and Technology, Wuhan University, Wuhan, Hubei 430072 (China); Ding, Wenkui; Shi, Anqi [School of Physics and Technology, Wuhan University, Wuhan, Hubei 430072 (China); Zhang, Wenxian, E-mail: wxzhang@whu.edu.cn [School of Physics and Technology, Wuhan University, Wuhan, Hubei 430072 (China)

    2016-08-12

    We investigate the dynamic nuclear polarization in a quantum dot. Due to the suppression of direct dipolar and indirect electron-mediated nuclear spin interactions by frequently injected electron spins, our analytical results under independent spin approximation agree well with quantum numerical simulations for a small number of nuclear spins. We find that the acquired nuclear polarization is highly inhomogeneous, proportional to the square of the local electron-nuclear hyperfine interaction constant. Starting from the inhomogeneously polarized nuclear spins, we further show that the electron polarization decay time can be extended 100 times even at a relatively low nuclear polarization. - Highlights: • Nuclear spin polarization is highly inhomogeneous after a dynamic nuclear polarization (DNP) process. • The DNP process is well described by an analytical model based on the independent spin approximation. • The highly inhomogeneous nuclear polarization significantly prolongs the electron spin coherence time.

  2. On the spectrum of secondary electrons emitted during nuclear $\\beta^{-}$-decay in few-electron atoms

    CERN Document Server

    Frolov, Alexei M

    2015-01-01

    Ionization of light atoms and ions during nuclear $\\beta^{-}$-decay is considered. We determine the velocity/momentum spectrum of secondary electrons emitted during nuclear $\\beta^{-}$-decay in one-electron tritium atom. The same method can be applied to describe velocity/momentum distributions of secondary electrons emitted from $\\beta^{-}$-decaying few-electron atoms and molecules.

  3. Development of the NPL gamma-ray spectrometer NANA for traceable nuclear decay and structure studies.

    Science.gov (United States)

    Lorusso, G; Shearman, R; Regan, P H; Judge, S M; Bell, S; Collins, S M; Larijani, C; Ivanov, P; Jerome, S M; Keightley, J D; Lalkovski, S; Pearce, A K; Podolyak, Zs

    2016-03-01

    We present a brief report on the progress towards the construction of the National Nuclear Array (NANA), a gamma-ray coincidence spectrometer for discrete-line nuclear structure and decay measurements. The proposed spectrometer will combine a gamma-ray energy resolution of approximately 3% at 1MeV with sub-nanosecond timing discrimination between successive gamma rays in mutually coincident decay cascades. We also review a number of recent measurements using coincidence fast-timing gamma-ray spectroscopy for nuclear structure studies, which have helped to inform the design criteria for the NANA spectrometer.

  4. Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators

    Energy Technology Data Exchange (ETDEWEB)

    Ricard-McCutchan, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Dimitriou, P. [Intl Atomic Energy Agency (IAEA), Vienna (Austria); Nichols, A. L. [Univ. of Surrey, Guildford (United Kingdom)

    2015-08-01

    The 21st meeting of the International Network of Nuclear Structure and Decay Data Evaluators was convened at the IAEA Headquarters, Vienna, from 20 to 24 April 2015 under the auspices of the IAEA Nuclear Data Section. This meeting was attended by 36 scientists from 15 Member States, plus IAEA staff, concerned with the compilation, evaluation and dissemination of nuclear structure and decay data. A summary of the meeting, data centre reports, various proposals considered, and actions agreed by the participants, as well as recommendations/conclusions are presented within this document.

  5. Complexity of pilgering in nuclear applications

    Directory of Open Access Journals (Sweden)

    Krishna Aditya Y V

    2014-11-01

    Full Text Available Nuclear reactors use various types and sections of tubes manufactured with exotic materials meeting special requirements. These Tubes are manufactured using a Cold working process of Pilgering. Pilgering process is influenced by a lot of factors making it a highly complex process. In this paper the various influencing factors are compiled, segregated and briefly discussed.

  6. Nuclear two-photon decay in 0 +→0 + transitions

    Science.gov (United States)

    Kramp, J.; Habs, D.; Kroth, R.; Music, M.; Schirmer, J.; Schwalm, D.; Broude, C.

    1987-11-01

    The two-photon decay of the first excited 0 + state of 16O has been measured using the Heidelberg-Darmstadt crystal ball. A branching ratio of {Γ γγ}/{Γ tot} = (6.6±0.5) · 10 -4 was obtained. As in the cases of 40Ca and 90Zr previously reported by us, the 2γ decay of 16O proceeds via double E1 and M1 transitions of similar strength; the evidence is the observed interference term in the 2γ angular correlation. The ratio of the matrix elements {α E1 }/{χ} for 16O was restricted to the two inverse values (-6.2±1.5) or (-0.16±0.04). An interpretation of 2γ matrix elements observed for 16O, 40Ca and 90Zr in terms of the electric polarizabilities and magnetic susceptibility is given leading to a qualitative understanding of this decay mode.

  7. Experiments searching for new interactions in nuclear beta-decay

    NARCIS (Netherlands)

    Jungmann, Klaus P.; Brown, BA; Engel, J; Haxton, W; RamseyMusolf, M; Romalis, M; Savard, G

    2009-01-01

    Precision measurements of beta-decays in nuclei, muons and neutrons allow to search for non V-A contributions in, weak interactions and to set; limits on parameters relevant to theoretical models beyond standard theory. Novel experiments are possible in particular at, presently operating stable beam

  8. Electron capture decay of {sup 116}In and nuclear structure of double {beta} decays

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, M.; Garcia, A.; Ortiz, C.E.; Kaloskamis, N.I. [University of Notre Dame, Notre Dame, Indiana 46556 (United States); Hindi, M.M. [Physics Department, Tennessee Technological University, Cookeville, Tennessee 38505 (United States); Norman, E.B. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Davids, C.N. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Civitarese, O. [Department of Physics, University of La Plata, C. C. 67, 1900-La Plata (Argentina); Suhonen, J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, SF-40351, Jyvaeskylae (Finland)

    1998-08-01

    Quasiparticle-random-phase-approximation (QRPA) calculations of double {beta} decays have not been able to reproduce data in the A=100 system. We propose the A=116 system{emdash}because of its smaller deformation{emdash}as a simpler system to test QRPA calculations. We present results of two experiments we performed, which determine the electron-capture-decay branch of {sup 116}In to be (2.27{plus_minus}0.63){times}10{sup {minus}2}{percent}, from which we deduce logft=4.39{sub {minus}0.15}{sup +0.10}. We present QRPA calculations and compare their predictions to experimental data. Finally we use these calculations to predict the 2{nu} double-{beta}-decay rate of {sup 116}Cd to the ground and excited states of {sup 116}Sn. {copyright} {ital 1998} {ital The American Physical Society}

  9. Nuclear matrix elements of the double beta decay for mass around 80

    Science.gov (United States)

    Yoshinaga, Naotaka; Higashiyama, Koji; Teruya, Eri

    2014-09-01

    In nature there are 30 kinds of nuclei which are expected to have double beta decays. Among them ten nuclei are actually observed for the neutrino double beta decays. Still no observation is made for the neutrinoless double beta decays (0 νββ) . The 0 νββ decay is expected to occur only when neutrinos have masses and they are Majorana particles. In that respect observation of 0 νββ is to determine whether neutrinos are Majorana particles or not. In theoretical side in order to estimate the half life of 0 νββ determination of the nuclear matrix elements are essential. They were calculated in many theoretical frameworks, but the results are not consistent in various models. In this study we carry out shell model calculations for 82Se and 82Kr nuclei. After obtaining the wavefunctions, we calculate the nuclear matrix elements. For comparison we make pair truncated shell model calculations.

  10. Nuclear matrix element of neutrinoless double-β decay: Relativity and short-range correlations

    Science.gov (United States)

    Song, L. S.; Yao, J. M.; Ring, P.; Meng, J.

    2017-02-01

    Background:The discovery of neutrinoless double-β (0 ν β β ) decay would demonstrate the nature of neutrinos, have profound implications for our understanding of matter-antimatter mystery, and solve the mass hierarchy problem of neutrinos. The calculations for the nuclear matrix elements M0 ν of 0 ν β β decay are crucial for the interpretation of this process. Purpose: We study the effects of relativity and nucleon-nucleon short-range correlations on the nuclear matrix elements M0 ν by assuming the mechanism of exchanging light or heavy neutrinos for the 0 ν β β decay. Methods:The nuclear matrix elements M0 ν are calculated within the framework of covariant density functional theory, where the beyond-mean-field correlations are included in the nuclear wave functions by configuration mixing of both angular-momentum and particle-number projected quadrupole deformed mean-field states. Results: The nuclear matrix elements M0 ν are obtained for ten 0 ν β β -decay candidate nuclei. The impact of relativity is illustrated by adopting relativistic or nonrelativistic decay operators. The effects of short-range correlations are evaluated. Conclusions: The effects of relativity and short-range correlations play an important role in the mechanism of exchanging heavy neutrinos though the influences are marginal for light neutrinos. Combining the nuclear matrix elements M0 ν with the observed lower limits on the 0 ν β β -decay half-lives, the predicted strongest limits on the effective masses are || |-1>3.065 ×108GeV for heavy neutrinos.

  11. Nuclear emulsion with molybdenum filling for observation of {beta}{beta} decay

    Energy Technology Data Exchange (ETDEWEB)

    Ashitkov, V.D. [Institute of Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218 Moscow (Russian Federation); Bagulya, A.V. [Lebedev Physical Institute, Leninsky Prospect 53, 119991 Moscow (Russian Federation); Barabash, A.S., E-mail: barabash@itep.r [Institute of Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218 Moscow (Russian Federation); Bradnova, V.Ya. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Chernyavsky, M.M. [Lebedev Physical Institute, Leninsky Prospect 53, 119991 Moscow (Russian Federation); Konovalov, S.I. [Institute of Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218 Moscow (Russian Federation); Okat' eva, N.M.; Orlova, G.I.; Polukhina, N.G. [Lebedev Physical Institute, Leninsky Prospect 53, 119991 Moscow (Russian Federation); Pozharova, E.A.; Smirnitsky, V.A. [Institute of Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218 Moscow (Russian Federation); Starkov, N.I.; Vladimirov, M.S. [Lebedev Physical Institute, Leninsky Prospect 53, 119991 Moscow (Russian Federation); Umatov, V.I. [Institute of Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218 Moscow (Russian Federation)

    2010-09-21

    The usage of nuclear emulsion with molybdenum powder filling ({approx}5% by weight of dry emulsion) for observation of {beta}{beta} decay is shown to be possible. Estimates for 1 kg of {sup 100}Mo with zero background give the sensitivity for the 0{nu}{beta}{beta} decay of {sup 100}Mo at the level of {approx}1.5x10{sup 24}yr for 1 yr of measurement. Promising elements for the double beta decay search, besides molybdenum ({sup 100}Mo), are also {sup 82}Se, {sup 150}Nd, {sup 96}Zr, {sup 130}Te, {sup 116}Cd, and {sup 48}Ca.

  12. Beta processes in a high-temperature field and nuclear multibeta decays

    Energy Technology Data Exchange (ETDEWEB)

    Kopytin, I. V., E-mail: kopytin@yandex.ru; Hussain, Imad A. [Voronezh State University (Russian Federation)

    2013-11-15

    Sources of the temperature dependence of rates of nuclear beta processes in matter of massive stars are systematized. Electron and positron beta decays and electron capture (K capture and the capture of unbound electrons) fromexcited nuclear states (thermal decays) are considered along with the photobeta decays from ground and excited nuclear states. The possible quantum degeneracy of an electron gas in matter and the degree of ionization of an atomic K shell in a high-temperature field are taken into account. For a number of multidecay odd-nuclei, the temperature dependences of the ratios of the total rates of their {beta}{sup -} decays to the sum of the total rates over all of decay modes for the same nuclei are calculated in the range of nuclear temperature from 2 to 3 Multiplication-Sign 10{sup 9} K. It is shown that the deviation of this ratio from the experimental value obtained at 'normal' temperature may be quite sizable. This circumstance should be taken into account in models that consider the problem of synthesis of nuclei in matter of massive stars.

  13. Recent status of the studies of nuclear masses and {beta}-decay

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masami [Waseda Univ., Tokyo (Japan). Advanced Research Center for Science and Engineering

    1996-05-01

    The recent status of the above studies was explained, especially, nuclear masses were described from the aspect of probability theory and that of {beta}-decay suggested that the first forbidden transition was hindered between the ground states. We have to study various systematics in order to know the mass surface, Way-Yamada-Matumoto type systematics is better to check the experimental nuclear masses. The gross theory is very useful to understand the general aspect of {beta}-decay. The understanding method of mass surface, systematic check of mass and hindrance of the first forbidden transition at rank 1 were explained. (S.Y.)

  14. Nuclear Reaction Uncertainties, Massive Gravitino Decays and the Cosmological Lithium Problem

    CERN Document Server

    Cyburt, Richard H; Fields, Brian D; Luo, Feng; Olive, Keith A; Spanos, Vassilis C

    2010-01-01

    We consider the effects of uncertainties in nuclear reaction rates on the cosmological constraints on the decays of unstable particles during or after Big-Bang nucleosynthesis (BBN). We identify the nuclear reactions due to non-thermal hadrons that are the most important in perturbing standard BBN, then quantify the uncertainties in these reactions and in the resulting light-element abundances. These results also indicate the key nuclear processes for which improved cross section data would allow different light-element abundances to be determined more accurately, thereby making possible more precise probes of BBN and evaluations of the cosmological constraints on unstable particles. Applying this analysis to models with unstable gravitinos decaying into neutralinos, we calculate the likelihood function for the light-element abundances measured currently, taking into account the current experimental errors in the determinations of the relevant nuclear reaction rates. We find a region of the gravitino mass and...

  15. Identification of a Nuclear Exosome Decay Pathway for Processed Transcripts

    DEFF Research Database (Denmark)

    Meola, Nicola; Domanski, Michal; Karadoulama, Evdoxia

    2016-01-01

    , the Zn-finger protein ZCCHC8, and the RNA-binding factor RBM7. NEXT primarily targets early and unprocessed transcripts, which demands a rationale for how the nuclear exosome recognizes processed RNAs. Here, we describe the poly(A) tail exosome targeting (PAXT) connection, which comprises the ZFC3H1 Zn...

  16. Decay spectroscopy for nuclear astrophysics: β- and β-delayed proton decay

    Science.gov (United States)

    Trache, L.; Banu, A.; Hardy, J. C.; Iacob, V. E.; McCleskey, M.; Roeder, B. T.; Simmons, E.; Spiridon, A.; Tribble, R. E.; Saastamoinen, A.; Jokinen, A.; Äysto, J.; Davinson, T.; Lotay, G.; Woods, P. J.; Pollacco, E.

    2012-02-01

    In several radiative proton capture reactions important in novae and XRBs, the resonant parts play the capital role. We use decay spectroscopy techniques to find these resonances and study their properties. We have developed techniques to measure beta- and beta-delayed proton decay of sd-shell, proton-rich nuclei produced and separated with the MARS recoil spectrometer of Texas A&M University. The short-lived radioactive species are produced in-flight, separated, then slowed down (from about 40 MeV/u) and implanted in the middle of very thin Si detectors. This allows us to measure protons with energies as low as 200 keV from nuclei with lifetimes of 100 ms or less. At the same time we measure gamma-rays up to 8 MeV with high resolution HPGe detectors. We have studied the decay of 23Al, 27P, 31Cl, all important for understanding explosive H-burning in novae. The technique has shown a remarkable selectivity to beta-delayed charged-particle emission and works even at radioactive beam rates of a few pps. The states populated are resonances for the radiative proton capture reactions 22Na(p,γ)23Mg (crucial for the depletion of 22Na in novae), 26mAl(p,γ)27Si and 30P(p,γ)31S (bottleneck in novae and XRB burning), respectively. Lastly, results with a new detector that allowed us to measure down to about 80 keV proton energy are announced.

  17. Radiotoxicity and decay heat power of spent nuclear fuel of VVER type reactors at long-term storage.

    Science.gov (United States)

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

    2005-01-01

    Radiotoxicity and decay heat power of the spent nuclear fuel of VVER-1000 type reactors are calculated during storage time up to 300,000 y. Decay heat power of radioactive waste (radwaste) determines parameters of the heat removal system for the safe storage of spent nuclear fuel. Radiotoxicity determines the radiological hazard of radwaste after its leakage and penetration into the environment.

  18. Upgrade of the SPIRAL identification station for high-precision measurements of nuclear β decay

    Energy Technology Data Exchange (ETDEWEB)

    Grinyer, G.F., E-mail: grinyer@ganil.fr [Grand Accélérateur National d' Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, Bvd Henri Becquerel, 14076 Caen (France); Thomas, J.C. [Grand Accélérateur National d' Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, Bvd Henri Becquerel, 14076 Caen (France); Blank, B. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1, UMR 5797, CNRS/IN2P3, Chemin de Solarium, BP 120, 33175 Gradignan (France); Bouzomita, H. [Grand Accélérateur National d' Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, Bvd Henri Becquerel, 14076 Caen (France); Austin, R.A.E. [Astronomy and Physics Department, Saint Mary' s University, Halifax, Nova Scotia, Canada B3H 3C3 (Canada); Ball, G.C. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3 (Canada); Bucaille, F.; Delahaye, P. [Grand Accélérateur National d' Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, Bvd Henri Becquerel, 14076 Caen (France); Finlay, P. [Instituut voor Kern- en Stralingsfysica, K.U. Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Frémont, G. [Grand Accélérateur National d' Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, Bvd Henri Becquerel, 14076 Caen (France); Gibelin, J. [LPC-Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, Caen (France); Giovinazzo, J. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1, UMR 5797, CNRS/IN2P3, Chemin de Solarium, BP 120, 33175 Gradignan (France); and others

    2014-03-21

    The low-energy identification station at SPIRAL (Système de Production d'Ions Radioactifs Accélérés en Ligne) has been upgraded for studying the β decays of short-lived radioactive isotopes and to perform high-precision half-life and branching-ratio measurements for superallowed Fermi and isospin T=1/2 mirror β decays. These new capabilities, combined with an existing Paul trap setup for measurements of β–ν angular-correlation coefficients, provide a powerful facility for investigating fundamental properties of the electroweak interaction through nuclear β decays. A detailed description of the design study, construction, and first results obtained from an in-beam commissioning experiment on the β{sup +} decays {sup 14} O and {sup 17}F are presented.

  19. The influence of nuclear deformations on the exotic cluster decay half-lives

    Science.gov (United States)

    Soylu, A.; Bayrak, O.; Evlice, S.

    2015-04-01

    We systematically study the investigation of the influence of nuclear deformations of the cluster and daughter nuclei on the exotic cluster decay half-lives of heavy nuclei by the WKB method and the Bohr-Sommerfeld quantization condition. Even if the deformations of both cluster and daughter in the half-live values of cluster decays improve the results, considering the deformation of clusters is more efficient than the deformation of daughter for the heavy cluster decay half-live calculations. Moreover, taking into account of angle orientations of daughter and cluster provides a positive contributions to the results as well. The results would be useful for experimental researches in half-lives of exotic decays of some heavy nuclei and radium isotopes.

  20. Nuclear structure calculations for two-neutrino double-beta decay

    CERN Document Server

    Sarriguren, P; de Guerra, E Moya

    2016-01-01

    We study the two-neutrino double-beta decay in 76Ge, 116Cd, 128Te, 130Te, and 150Nd, as well as the two Gamow-Teller branches that connect the double-beta decay partners with the states in the intermediate nuclei. We use a theoretical microscopic approach based on a deformed selfconsistent mean field with Skyrme interactions including pairing and spin-isospin residual forces, which are treated in a proton-neutron quasiparticle random-phase approximation. We compare our results for Gamow-Teller strength distributions with experimental information obtained from charge-exchange reactions. We also compare our results for the two-neutrino double-beta decay nuclear matrix elements with those extracted from the measured half-lives. Both single-state and low-lying-state dominance hypotheses are analyzed theoretically and experimentally making use of recent data from charge-exchange reactions and beta decay of the intermediate nuclei.

  1. Search for Rare Nuclear Decays with HPGe Detectors at the STELLA Facility of the LNGS

    CERN Document Server

    Belli, P; Cappella, F; Cerulli, R; Danevich, F A; d'Angelo, A; d'Angelo, S; Di Marco, A; Di Vacri, M L; Incicchitti, A; Kovtun, G P; Kovtun, N G; Laubenstein, M; Nisi, S; Poda, D V; Polischuk, O G; Shcherban, A P; Solopikhin, D A; Suhonen, J; Tolmachev, A V; Tretyak, V I; Yavetskiy, R P

    2013-01-01

    Results on the search for rare nuclear decays with the ultra low background facility STELLA at the LNGS using gamma ray spectrometry are presented. In particular, the best T1/2 limits were obtained for double beta processes in 96Ru and 104Ru. Several isotopes, which potentially decay through different double beta decay channels, including also possible resonant double electron captures, were investigated for the first time (156Dy, 158Dy, 184Os, 192Os, 190Pt, 198Pt). Search for resonant absorption of solar 7Li axions in a LiF crystal gave the best limit for the mass of 7Li axions (< 8.6 keV). Rare alpha decay of 190Pt to the first excited level of 186Os (Eexc = 137.2 keV) was observed for the first time.

  2. Status and Future of Nuclear Matrix Elements for Neutrinoless Double-Beta Decay: A Review

    CERN Document Server

    Engel, Jonathan

    2016-01-01

    The nuclear matrix elements that govern the rate of neutrinoless double beta decay must be accurately calculated if experiments are to reach their full potential. Theorists have been working on the problem for a long time but have recently stepped up their efforts as ton-scale experiments have begun to look feasible. Here we review past and recent work on the matrix elements in a wide variety of nuclear models and discuss work that will be done in the near future. Ab initio nuclear-structure theory, which is developing rapidly, holds out hope of more accurate matrix elements with quantifiable error bars.

  3. Status and future of nuclear matrix elements for neutrinoless double-beta decay: a review

    Science.gov (United States)

    Engel, Jonathan; Menéndez, Javier

    2017-04-01

    The nuclear matrix elements that govern the rate of neutrinoless double beta decay must be accurately calculated if experiments are to reach their full potential. Theorists have been working on the problem for a long time but have recently stepped up their efforts as ton-scale experiments have begun to look feasible. Here we review past and recent work on the matrix elements in a wide variety of nuclear models and discuss work that will be done in the near future. Ab initio nuclear-structure theory, which is developing rapidly, holds out hope of more accurate matrix elements with quantifiable error bars.

  4. Viral Subversion of the Nuclear Pore Complex

    Directory of Open Access Journals (Sweden)

    Valerie Le Sage

    2013-08-01

    Full Text Available The nuclear pore complex (NPC acts as a selective barrier between the nucleus and the cytoplasm and is responsible for mediating communication by regulating the transport of RNA and proteins. Numerous viral pathogens have evolved different mechanisms to hijack the NPC in order to regulate trafficking of viral proteins, genomes and even capsids into and out of the nucleus thus promoting virus replication. The present review examines the different strategies and the specific nucleoporins utilized during viral infections as a means of promoting their life cycle and inhibiting host viral defenses.

  5. Universal long-time behavior of nuclear spin decays in a solid.

    Science.gov (United States)

    Morgan, S W; Fine, B V; Saam, B

    2008-08-08

    Magnetic resonance studies of nuclear spins in solids are exceptionally well suited to probe the limits of statistical physics. We report experimental results indicating that isolated macroscopic systems of interacting nuclear spins possess the following fundamental property: spin decays that start from different initial configurations quickly evolve towards the same long-time behavior. This long-time behavior is characterized by the shortest ballistic microscopic time scale of the system and therefore falls outside of the validity range for conventional approximations of statistical physics. We find that the nuclear free-induction decay and different solid echoes in hyperpolarized solid xenon all exhibit sinusoidally modulated exponential long-time behavior characterized by identical time constants. This universality was previously predicted on the basis of analogy with resonances in classical chaotic systems.

  6. Search for rare nuclear decays with HPGe detectors at the STELLA facility of the LNGS

    Energy Technology Data Exchange (ETDEWEB)

    Belli, P.; Di Marco, A. [INFN, Sezione di Roma Tor Vergata, Rome (Italy); Bernabei, R.; D' Angelo, S. [INFN, Sezione di Roma Tor Vergata, Rome, Italy and Dipartimento di Fisica, Università di Roma Tor Vergata, Rome (Italy); Cappella, F.; D' Angelo, A.; Incicchitti, A. [INFN, Sezione di Roma La Sapienza, Rome, Italy and Dipartimento di Fisica, Università di Roma La Sapienza, Rome (Italy); Cerulli, R.; Di Vacri, M. L.; Laubenstein, M.; Nisi, S. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (AQ) (Italy); Danevich, F. A.; Kobychev, V. V.; Poda, D. V.; Tretyak, V. I. [Institute for Nuclear Research, Kyiv (Ukraine); Kovtun, G. P.; Kovtun, N. G.; Shcherban, A. P.; Solopikhin, D. A. [Kharkiv Institute of Physics and Technology, Kharkiv (Ukraine); Polischuk, O. G. [INFN, Sezione di Roma La Sapienza, Rome, Italy and Institute for Nuclear Research, Kyiv (Ukraine); and others

    2013-12-30

    Results on the search for rare nuclear decays with the ultra low background facility STELLA at the LNGS using gamma ray spectrometry are presented. In particular, the best T{sub 1/2} limits were obtained for double beta processes in {sup 96}Ru and {sup 104}Ru. Several isotopes, which potentially decay through different 2β channels, including also possible resonant double electron captures, were investigated for the first time ({sup 156}Dy, {sup 158}Dy, {sup 184}Os, {sup 192}Os, {sup 190}Pt, {sup 198}Pt). Search for resonant absorption of solar {sup 7}Li axions in a LiF crystal gave the best limit for the mass of {sup 7}Li axions (< 8.6 keV). Rare alpha decay of {sup 190}Pt to the first excited level of {sup 186}Os(E{sub exc} = 137.2keV) was observed for the first time.

  7. The 0nbb-decay nuclear matrix elements with self-consistent short-range correlations

    CERN Document Server

    Simkovic, Fedor; Muther, Herbert; Rodin, Vadim; Stauf, Markus

    2009-01-01

    A self-consistent calculation of nuclear matrix elements of the neutrinoless double beta decays (0nbb) of 76Ge, 82Se, 96Zr, 100Mo, 116Cd, 128Te, 130Te and 130Xe is presented in the framework of the renormalized quasiparticle random phase approximation (RQRPA) and the standard QRPA. The pairing and residual interactions as well as the two-nucleon short-range correlations are for the first time derived from the same modern realistic nucleon-nucleon potentials, namely from charge-dependent Bonn potential (CD-Bonn) and the Argonne V18 potential. In a comparison with the traditional approach of using the Miller-Spencer Jastrow correlations matrix elements for the 0nbb-decay are obtained, which are larger in magnitude. We analyze the differences among various two-nucleon correlations including those of the unitary correlation operator method (UCOM) and quantify the uncertainties in the calculated 0nbb-decay matrix elements.

  8. Simulations of Radioactive Decays: an Application of Low-Energy Electromagnetic Packages for the Nuclear Medicine

    Directory of Open Access Journals (Sweden)

    Munkhbaatar Batmunkh

    2015-12-01

    Full Text Available Problems of the radiobiology and the nuclear medicine require clarifying the specifi cs of radionuclides interactions with unhealthy cells. In this work we aimed to simulate emitting particles tracks of radionuclides and their radioactive decays at DNA level inside the cell nucleus. Accordingly, using the Monte Carlo-based track structure simulation technique, we estimated the radial distribution of deposited energy and kinetic energy spectra of electrons produced by primary particles resulting from radioactive decays of diff erent radionuclides within cell nucleus. To address the possibility of DNA damage, we performed the cluster analysis of track structures of emitted particles inside the volumes corresponding to the size of the native double-stranded DNA. For this purpose, G4-RadioactiveDecay and low- energy electromagnetic packages form Geant4 Monte-Carlo toolkit were combined together. Besides, a comparative analysis was performed for various low-energy electromagnetic packages as G4-DNA and G4-Livermore

  9. Novel nuclear structure aspects of the O{nu}{beta}{beta}-decay

    Energy Technology Data Exchange (ETDEWEB)

    Menendez, J; Poves, A [Departamento de Fisica Teorica, and IFT, UAM-CSIC, Universidad Autonoma de Madrid, 28049-Madrid (Spain); Caurier, E; Nowacki, F, E-mail: alfredo.poves@uam.es [IPHC, IN2P3-CNRS/Universite Louis Pasteur, 67037-Strasbourg (France)

    2011-01-01

    We explore the influence of the deformation on the nuclear matrix elements of the neutrinoless double beta decay (NME), concluding that the difference in deformation -or more generally in the amount of quadrupole correlations- between parent and grand daughter nuclei quenches strongly the decay. We correlate these differences with the seniority structure of the nuclear wave functions. In this context, we examine the present discrepancies between the NME's obtained in the framework of the Interacting Shell Model and the Quasiparticle RPA. In our view, part of the discrepancy can be due to the limitations of the spherical QRPA in treating nuclei which have strong quadrupole correlations. We surmise that the NME's in a basis of generalized seniority are approximately model independent, i. e. they are 'universal'.

  10. Nuclear Zemach Moments and Finite-Size Corrections to Allowed Beta Decay

    CERN Document Server

    Wang, X B; Hayes, A C

    2016-01-01

    The finite-size correction to $\\beta$-decay plays an important role in determining the expected antineutrino spectra from reactors at a level that is important for the reactor-neutrino anomaly. Here we express the leading-order finite-size correction to allowed $\\beta$-decay in terms of Zemach moments. We calculate the Zemach moments within a Hartree-Fock model using a Skyrme-like energy density functional. We find that the Zemach moments are increased relative to predictions based on the simple assumption of identical uniform nuclear-charge and weak-transition densities. However, for allowed ground-state to ground-state transitions in medium and heavy nuclei, the detailed nuclear structure calculations do not change the finite-size corrections significantly from the simple model predictions, and are only 10-15% larger than the latter even though the densities differ significantly.

  11. THE AIMS AND ACTIVITIES OF THE INTERNATIONAL NETWORK OF NUCLEAR STRUCTURE AND DECAY DATA EVALUATORS.

    Energy Technology Data Exchange (ETDEWEB)

    NICHOLS,A.L.; TULI, J.K.

    2007-04-22

    International Network of Nuclear Structure and Decay Data (NSDD) Evaluators consists of a number of evaluation groups and data service centers in several countries that appreciate the merits of working together to maintain and ensure the quality and comprehensive content of the ENSDF database (Evaluated Nuclear Structure Data File). Biennial meetings of the network are held under the auspices of the International Atomic Energy Agency (IAEA) to assign evaluation responsibilities, monitor progress, discuss improvements and emerging difficulties, and agree on actions to be undertaken by individual members. The evaluated data and bibliographic details are made available to users via various media, such as the journals ''Nuclear Physics A'' and ''Nuclear Data Sheets'', the World Wide Web, on CD-ROM, wall charts of the nuclides and ''Nuclear Wallet Cards''. While the ENSDF master database is maintained by the US National Nuclear Data Center at the Brookhaven National Laboratory, these data are also available from other nuclear data centers including the IAEA Nuclear Data Section. The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy, in cooperation with the IAEA, organizes workshops on NSDD at regular intervals. The primary aims of these particular workshops are to provide hands-on training in the data evaluation processes, and to encourage new evaluators to participate in NSDD activities. The technical contents of these NSDD workshops are described, along with the rationale for the inclusion of various topics.

  12. Short-range correlation effects on the nuclear matrix element of neutrinoless double-$\\beta$ decay

    CERN Document Server

    Benhar, Omar; Speranza, Enrico

    2014-01-01

    We report the results of a calculation of the nuclear matrix element of neutrinoless double-$\\beta$ decay of $^{48}$Ca, carried out taking into account nucleon-nucleon correlations in both coordinate- and spin-space. Our numerical results, obtained using nuclear matter correlation functions, suggest that inclusion of correlations leads to a $\\sim$ $20\\%$ decrease of the matrix element, with respect to the shell model prediction. This conclusion is supported by the results of an independent calculation, in which correlation effects are taken into account using the spectroscopic factors of $^{48}$Ca obtained from an {\\em ab intitio} many body approach.

  13. ϕ meson mass and decay width in nuclear matter and nuclei

    Science.gov (United States)

    Cobos-Martínez, J. J.; Tsushima, K.; Krein, G.; Thomas, A. W.

    2017-08-01

    The mass and decay width of the ϕ meson in cold nuclear matter are computed in an effective Lagrangian approach. The medium dependence of these properties are obtained by evaluating kaon-antikaon loop contributions to the ϕ self-energy, employing the medium-modified kaon masses, calculated using the quark-meson coupling model. The loop integral is regularized with a dipole form factor, and the sensitivity of the results to the choice of cutoff mass in the form factor is investigated. At normal nuclear matter density we find a downward shift of the ϕ mass by a few percent, while the decay width is enhanced by an order of magnitude. For a large variation of the cutoff mass parameter, the results for the ϕ mass and the decay width turn out to vary very little. Our results support results in the literature which suggest that one should observe a small downward mass shift and a large broadening of the decay width. In order to explore the possibility of studying the binding and absorption of ϕ mesons in nuclei, we also present the single-particle binding energies and half-widths of ϕ-nucleus bound states for some selected nuclei.

  14. Ingredients of nuclear matrix element for two-neutrino double-beta decay of 48Ca

    CERN Document Server

    Iwata, Y; Utsuno, Y; Honma, M; Abe, T; Otsuka, T

    2014-01-01

    Large-scale shell model calculations including two major shells are carried out, and the ingredients of nuclear matrix element for two-neutrino double beta decay are investigated. Based on the comparison between the shell model calculations accounting only for one major shell ($pf$-shell) and those for two major shells ($sdpf$-shell), the effect due to the excitation across the two major shells is quantitatively evaluated.

  15. Laser assisted nuclear decay spectroscopy: A new method for studying neutron-deficient francium

    CERN Document Server

    Lynch, Kara Marie

    2015-01-01

    Radioactive decay studies of rare isotopes produced at radioactive ion beam facilities have often been hindered by the presence of isobaric and isomeric contamination. The Collinear Resonance Ionization Spectroscopy (CRIS) experiment at ISOLDE, CERN uses laser radiation to stepwise excite and ionize an atomic beam in a particular isomeric state. Deflection of this selectively ionized beam of exotic nuclei, from the remaining neutral contaminants, allows ultra-sensitive detection of rare isotopes and nuclear structure measurements in background-free conditions.\

  16. Prospects for precision measurements in nuclear beta decay at the LHC era

    CERN Document Server

    González-Alonso, Martín

    2013-01-01

    Precision measurements in nuclear beta decay offer a sensitive window to search for new physics beyond the standard electroweak model and allow also the determination of the fundamental weak vector coupling in processes involving the lightest quarks. Searches for new physics are also a strong motivation for experiments carried out at the high energy frontier reached at the most powerful particle colliders. It is instructive to confront results from the low energy and the high energy frontiers in order to look for possible complementarities and orient new avenues for experiments at low energies. We review here the status of constraints on new physics obtained from nuclear and neutron decays and compare them to those from other semi-leptonic processes and from the LHC. We stress the requirements of new precision experiments in beta decay in order to impact the search for new physics at the light of current and projected LHC results. We describe recent experimental results and ongoing developments in nuclear and...

  17. Complex decay patterns in atomic core photoionization disentangled by ion-recoil measurements

    Energy Technology Data Exchange (ETDEWEB)

    Guillemin, Renaud; Bomme, Cedric; Marin, Thierry; Journel, Loic; Marchenko, Tatiana; Kushawaha, Rajesh K.; Piancastelli, Maria Novella; Simon, Marc [Universite Pierre et Marie Curie, Universite Paris 06, Laboratoire de Chimie Physique Matiere et Rayonement, 11 rue Pierre et Marie Curie, FR-75231 Paris Cedex 05 (France); Centre National de la Recherche Scientifique, Laboratoire de Chimie Physique Matiere et Rayonement (UMR7614), 11 rue Pierre et Marie Curie, FR-75231 Paris Cedex 05 (France); Trcera, Nicolas [Synchrotron SOLEIL, l' Orme des Merisiers, Saint-Aubin, BP 48, FR-91192 Gif-sur-Yvette Cedex (France)

    2011-12-15

    Following core 1s ionization and resonant excitation of argon atoms, we measure the recoil energy of the ions due to momentum conservation during the emission of Auger electrons. We show that such ion momentum spectroscopy can be used to disentangle to some degree complex decay patterns, involving both radiative and nonradiative decays.

  18. THE COMPLEX ORGANIZATION OF EUKARYOTIC CELL NUCLEUS (III: THE NUCLEAR MATRIX AND THE NUCLEAR LAMINA

    Directory of Open Access Journals (Sweden)

    Cristian S. Cimpeanu

    2013-07-01

    Full Text Available A large variety of nuclear fibrous proteins (such as actin, myosin, lamin B, transcription factors, topoisomerases, etc represent constitutive elements of complex structures present in the eukaryotic nuclei: the nuclear matrix and the nuclear lamina, repectively. These nuclear compartments, with fibrous network-like structure, play crucialroles in structural organization of nuclei, chromatin remodeling, DNA transcription, signals transduction, cell cycle regulation, embryonic development and other nuclear basic processes.

  19. Canonical Poly(A Polymerase Activity Promotes the Decay of a Wide Variety of Mammalian Nuclear RNAs.

    Directory of Open Access Journals (Sweden)

    Stefan M Bresson

    2015-10-01

    Full Text Available The human nuclear poly(A-binding protein PABPN1 has been implicated in the decay of nuclear noncoding RNAs (ncRNAs. In addition, PABPN1 promotes hyperadenylation by stimulating poly(A-polymerases (PAPα/γ, but this activity has not previously been linked to the decay of endogenous transcripts. Moreover, the mechanisms underlying target specificity have remained elusive. Here, we inactivated PAP-dependent hyperadenylation in cells by two independent mechanisms and used an RNA-seq approach to identify endogenous targets. We observed the upregulation of various ncRNAs, including snoRNA host genes, primary miRNA transcripts, and promoter upstream antisense RNAs, confirming that hyperadenylation is broadly required for the degradation of PABPN1-targets. In addition, we found that mRNAs with retained introns are susceptible to PABPN1 and PAPα/γ-mediated decay (PPD. Transcripts are targeted for degradation due to inefficient export, which is a consequence of reduced intron number or incomplete splicing. Additional investigation showed that a genetically-encoded poly(A tail is sufficient to drive decay, suggesting that degradation occurs independently of the canonical cleavage and polyadenylation reaction. Surprisingly, treatment with transcription inhibitors uncouples polyadenylation from decay, leading to runaway hyperadenylation of nuclear decay targets. We conclude that PPD is an important mammalian nuclear RNA decay pathway for the removal of poorly spliced and nuclear-retained transcripts.

  20. Neutrino nuclear responses for double beta decays and astro neutrinos by charge exchange reactions

    Science.gov (United States)

    Ejiri, Hiroyasu

    2014-09-01

    Neutrino nuclear responses are crucial for neutrino studies in nuclei. Charge exchange reactions (CER) are shown to be used to study charged current neutrino nuclear responses associated with double beta decays(DBD)and astro neutrino interactions. CERs to be used are high energy-resolution (He3 ,t) reactions at RCNP, photonuclear reactions via IAR at NewSUBARU and muon capture reactions at MUSIC RCNP and MLF J-PARC. The Gamow Teller (GT) strengths studied by CERs reproduce the observed 2 neutrino DBD matrix elements. The GT and spin dipole (SD) matrix elements are found to be reduced much due to the nucleon spin isospin correlations and the non-nucleonic (delta isobar) nuclear medium effects. Impacts of the reductions on the DBD matrix elements and astro neutrino interactions are discussed.

  1. Contribution of Neutron Beta Decay to Radiation Belt Pumping from High Altitude Nuclear Explosion

    Energy Technology Data Exchange (ETDEWEB)

    Marrs, R

    2002-11-13

    In 1962, several satellites were lost following high altitude nuclear tests by the United States and the Soviet Union. These satellite failures were caused by energetic electrons injected into the earth's radiation belts from the beta decay of bomb produced fission fragments and neutrons. It has been 40 years since the last high altitude nuclear test; there are now many more satellites in orbit, and it is important to understand their vulnerability to radiation belt pumping from nuclear explosions at high altitude or in space. This report presents the results of a calculation of the contribution of neutron beta decay to artificial belt pumping. For most high altitude nuclear explosions, neutrons are expected to make a smaller contribution than fission products to the total trapped electron inventory, and their contribution is usually neglected. However, the neutron contribution may dominate in cases where the fission product contribution is suppressed due to the altitude or geomagnetic latitude of the nuclear explosion, and for regions of the radiation belts with field lines far from the detonation point. In any case, an accurate model of belt pumping from high altitude nuclear explosions, and a self-consistent explanation of the 1962 data, require inclusion of the neutron contribution. One recent analysis of satellite measurements of electron flux from the 1962 tests found that a better fit to the data is obtained if the neutron contribution to the trapped electron inventory was larger than that of the fission products [l]. Belt pumping from high altitude nuclear explosions is a complicated process. Fission fragments are dispersed as part of the ionized bomb debris, which is constrained and guided by the earth's magnetic field. Those fission products that beta decay before being lost to the earth's atmosphere can contribute trapped energetic electrons to the earth's radiation belts. There has been a large effort to develop computer models for

  2. Compilation of nuclear decay data used for dose calculation. Revised data for radionuclides listed in ICRP Publication 38

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Akira; Yamaguchi, Yasuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-03-01

    New nuclear decay data used for dose calculation have been compiled for 817 radionuclides that are listed in ICRP Publication 38 (Publ. 38) and for 6 additional isomers. The decay data were prepared using decay data sets from the Evaluated Nuclear Structure Data File (ENSDF), the latest version in August 1997. Basic nuclear properties in the decay data sets that are particularly important for calculating energies and intensities of emissions were examined and updated by referring to NUBASE, the database for nuclear and decay properties of nuclides. The reviewed and updated data were half-life, decay mode and its branching ratio, spin and parity of the ground and isomeric states, excitation energy of isomers, and Q value. In addition, possible revisions of partial and incomplete decay data sets were done for their format and syntax errors, level schemes, normalization records, and so on. After that, the decay data sets were processed by EDISTR in order to compute the energies and intensities of {alpha} particles, {beta} particles, {gamma} rays, internal conversion electrons, X rays, and Auger electrons emitted in nuclear transformation. For spontaneously fissioning nuclides, the average energies and intensities of neutrons, fission fragments, prompt {gamma} rays, delayed {gamma} rays, and {beta} particles were also calculated. The compiled data were prepared in two different types of format: Publ. 38 and NUCDECAY formats. Comparison of the compiled decay data with those in Publ. 38 was also presented. The decay data will be widely used for internal and external dose calculations in radiation protection and will be beneficial to a future revision of ICRP Publ. 38. (author)

  3. Nuclear Structure Calculations for Two-Neutrino Double-β Decay

    Directory of Open Access Journals (Sweden)

    P. Sarriguren

    2016-01-01

    Full Text Available We study the two-neutrino double-β decay in 76Ge, 116Cd, 128Te, 130Te, and 150Nd, as well as the two Gamow-Teller branches that connect the double-β decay partners with the states in the intermediate nuclei. We use a theoretical microscopic approach based on a deformed self-consistent mean field with Skyrme interactions including pairing and spin-isospin residual forces, which are treated in a proton-neutron quasiparticle random-phase approximation. We compare our results for Gamow-Teller strength distributions with experimental information obtained from charge-exchange reactions. We also compare our results for the two-neutrino double-β decay nuclear matrix elements with those extracted from the measured half-lives. Both single-state and low-lying-state dominance hypotheses are analyzed theoretically and experimentally making use of recent data from charge-exchange reactions and β decay of the intermediate nuclei.

  4. New Decay Data Sub-library for Calculation of Nuclear Reactors Antineutrino Spectra

    Science.gov (United States)

    Sonzogni, Alejandro; McCutchan, Elizabeth; Johnson, Timothy

    2015-10-01

    The ENDF/B-VII.1 decay data sub-library contains up-to-date decay properties for all known nuclides and can be used in a wide variety of applications such as decay heat, delayed nu-bar and astrophysics. We have recently completed an upgrade to the ENDF/B-VII.1 decay data sub-library in order to better calculate antineutrino spectra from fission of actinide nuclides. This sub-library has been used to identify the main contributors to the antineutrino spectra as well as to derive a systematic behavior of the energy integrated spectra similar to that of the beta-delayed neutron multiplicities. The main improvements have been the use of the TAGS data from Algora et al and Greenwood et al, as well as some of the single beta spectrum data from Rudstam et al to obtain beta minus level feedings. Additionally, we have calculated the antineutrino spectra for neutron energies higher than thermal, needed for highly-enriched uranium cores, such as the HFIR in ORNL that will be used in the PROSPECT experiment. These calculations are relevant since the high precision beta spectra which are used in many antineutrino calculations were measured at thermal energies. The impact of the fission yield data on these calculations will be discussed. This work was sponsored by the Office of Nuclear Physics, Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-98CH10886.

  5. Measurement of $\\beta\\beta$ Decay-Simulating Events in Nuclear Emulsion with Molybdenum Filling

    CERN Document Server

    Ashitkov, V D; Bradnova, V Ya; Ditlov, V A; Dubinina, V V; Egorenkova, N P; Konovalov, S I; Pozharova, E A; Polukhina, N G; Smirnitsky, V A; Starkov, N I; Chernyavsky, M M; Shchedrina, T V; Umatov, V I

    2011-01-01

    The measurement of positron--nucleus collisions was used to estimate the possibility of suppressing background events that simulate $\\beta\\beta$ decay in the emulsion region adjacent to molybdenum conglomerates. The range of the escape of two relativistic particles from the interaction was found to be $ = (0.60\\pm 0.03) ~\\mu$m, which approximately corresponds to the grain size of developed nuclear emulsion. No correlation of the values of d with the angle between two relativistic particles was observed. It was shown that it was possible to exclude $\\beta\\beta$ decay background from electrons emerging in the decay of elements of naturally occurring radioactive chains. The background from $\\beta$ decays of $^{90}$Sr and $^{40}$K available in emulsion around Mo conglomerates was determined by the ratio of the volume $(\\sim d^3)$ to the total volume of emulsion and was found to be $1.5\\cdot 10^{-2}$. It was shown that the backgrounds from $^{40}$K, $^{90}$Sr and natural radioactivity could be significantly suppre...

  6. Solar Influence on Nuclear Decay Rates: Constraints from the MESSENGER Mission

    CERN Document Server

    Fischbach, Ephraim; Gold, Robert E; Goldsten, John O; Lawrence, David J; McNutt, Ralph J; Rhodes, Edgar A; Jenkins, Jere H; Longuski, John

    2011-01-01

    We have analyzed Cs-137 decay data, obtained from a small sample onboard the MESSENGER spacecraft en route to Mercury, with the aim of setting limits on a possible correlation between nuclear decay rates and solar activity. Such a correlation has been suggested recently on the basis of data from Mn-54 decay during the solar flare of 13 December 2006, and by indications of an annual and other periodic variations in the decay rates of Si-32, Cl-36, and Ra-226. Data from five measurements of the Cs-137 count rate over a period of approximately 5.4 years have been fit to a formula which accounts for the usual exponential decrease in count rate over time, along with the addition of a theoretical solar contribution varying with MESSENGER-Sun separation. The indication of solar influence is then characterized by a non-zero value of the calculated parameter \\xi, and we find \\xi=(2.8+/-8.1)x10^{-3} for Cs-137. A simulation of the increased data that can hypothetically be expected following Mercury orbit insertion on 1...

  7. On the benefits of an integrated nuclear complex for Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Blink, J.A. [Lawrence Livermore National Laboratory, Las Vegas, NV (United States); Halsey, W.G. [Lawrence Livermore National Lab., CA (United States)

    1994-01-01

    An integrated nuclear complex is proposed for location at the Nevada Test Site. In addition to solving the nuclear waste disposal problem, this complex would tremendously enhance the southern Nevada economy, and it would provide low cost electricity to each resident and business in the affected counties. Nuclear industry and the national economy would benefit because the complex would demonstrate the new generation of safer nuclear power plants and revitalize the industry. Many spin-offs of the complex would be possible, including research into nuclear fusion and a world class medical facility for southern Nevada. For such a complex to become a reality, the cycle of distrust between the federal government and the State of Nevada must be broken. The paper concludes with a discussion of implementation through a public process led by state officials and culminating in a voter referendum.

  8. Search for Perturbations of Nuclear Decay Rates Induced by Reactor Electron Antineutrinos

    CERN Document Server

    Barnes, V E; Bryan, C D; Cinko, N; Deichert, G G; Gruenwald, J T; Heim, J M; Kaplan, H B; LaZur, R; Neff, D; Nistor, J M; Sahelijo, N; Fischbach, E

    2016-01-01

    We report the results of an experiment conducted near the High Flux Isotope Reactor of Oak Ridge National Laboratory, designed to address the question of whether a flux of reactor-generated electron antineutrinos can alter the rates of weak nuclear interaction-induced decays for Mn-54, Na-22, and Co-60. This experiment, while quite sensitive, cannot exclude perturbations less than one or two parts in $10^4$ in $\\beta$ decay (or electron capture) processes, in the presence of an antineutrino flux of $3\\times 10^{12}$ cm$^{-2}$ s$^{-1}$. The present experimental methods are applicable to a wide range of isotopes. Improved sensitivity in future experiments may be possible if we can understand and reduce the dominant systematic uncertainties.

  9. Nuclear matrix element for two neutrino double beta decay from 136Xe

    CERN Document Server

    Ejiri, Hiroyasu

    2012-01-01

    The nuclear matrix element for the two neutrino double beta decay (DBD) of 136Xe was evaluated by FSQP (Fermi Surface Quasi Particle model), where experimental GT strengths measured by the charge exchange reaction and those by the beta decay rates were used. The 2 neutrino DBD matrix element is given by the sum of products of the single beta matrix elements via low-lying (Fermi Surface) quasi-particle states in the intermediate nucleus. 136Xe is the semi-magic nucleus with the closed neutron-shell, and the beta + transitions are almost blocked. Thus the 2 neutrino DBD is much suppressed. The evaluated 2 neutrino DBD matrix element is consistent with the observed value.

  10. Signals of Bose Einstein condensation and Fermi quenching in the decay of hot nuclear systems

    Directory of Open Access Journals (Sweden)

    P. Marini

    2016-05-01

    Full Text Available We report on first experimental observations of nuclear fermionic and bosonic components displaying different behaviours in the decay of hot Ca projectile-like sources produced in mid-peripheral collisions at sub-Fermi energies. The experimental setup, constituted by the coupling of the INDRA 4π detector array to the forward angle VAMOS magnetic spectrometer, allowed to reconstruct the mass, charge and excitation energy of the decaying hot projectile-like sources. By means of quantum-fluctuation analysis techniques, temperatures and local partial densities of bosons and fermions could be correlated to the excitation energy of the reconstructed system. The results are consistent with the production of dilute mixed systems of bosons and fermions, where bosons experience higher phase-space and energy density as compared to the surrounding fermionic gas. Our findings recall phenomena observed in the study of Bose condensates and Fermi gases in atomic traps despite the different scales.

  11. Spin dipole nuclear matrix elements for double beta decay nuclei by charge-exchange reactions

    CERN Document Server

    Ejiri, H

    2016-01-01

    Spin dipole (SD) strengths for double beta-decay (DBD) nuclei were studied experimentally for the first time by using measured cross sections of (3He,t) charge exchange reactions (CERs). Then SD nuclear matrix elements (NMEs) for low-lying 2- states were derived from the experimental SD strengths by referring to the experimental GT (Gamow-Teller) and F (Fermi) strengths. They are consistent with the empirical SD NMEs based on the quasi-particle model with the empirical effective SD coupling constant. The CERs are used to evaluate the SD NME, which is associated with one of the major components of the neutrino-less DBD NME.

  12. Toward a better parameterization of nuclear density for α-decay calculation

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, M.; Ellithi, A.Y. [Physics Department, Faculty of Science, Cairo University, Giza (Egypt); Adel, A. [Physics Department, Faculty of Science, Cairo University, Giza (Egypt); Physics Department, College of Science, Majmaah University, Al Zulfi (Saudi Arabia); Abdulghany, A.R., E-mail: abdulghany@sci.cu.edu.eg [Physics Department, Faculty of Science, Cairo University, Giza (Egypt)

    2016-03-15

    Starting from three-parameter Fermi distribution of nuclear densities, we used two formulas, for calculating the half-density radius, to study the effect of variation of radius of daughter nucleus on both α-decay half-life and α-preformation factor. We compared the results of the aforementioned two formulas with the corresponding results obtained from the nuclear densities of Hartree–Fock calculation derived from the BSk2 Skyrme force. We considered >60 isotopes of Po and Rn α-emitter elements and studied the variation of half-life and preformation factor with density parameters. We found that the variation of density parameters of daughter nuclei highly affects the calculated half-life and the extracted value of preformation factor, but the behavior of these two quantities with variation of parent neutron number is almost independent of the density parameters.

  13. Summary Report of a Specialized Workshop on Nuclear Structure and Decay Data (NSDD) Evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, Alan L. [Univ. of Surrey, Guildford (United Kingdom); Dimitrious, P. [IAEA Nuclear Data Section, Vienna (Austria); Kondev, F. G. [Argonne National Lab. (ANL), Argonne, IL (United States); Ricard-McCutchan, E. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-04-27

    A three-day specialised workshop on Nuclear Structure and Decay Data Evaluations was organised and held at the headquarters of the International Atomic Energy Agency in Vienna, Austria, from 27 to 29 April 2015. This workshop covered a wide range of important topics and issues addressed when evaluating and maintaining the Evaluated Nuclear Structure Data File (ENSDF). The primary aim was to improve evaluators’ abilities to identify and understand the most appropriate evaluation processes to adopt in the formulation of individual ENSDF data sets. Participants assessed and reviewed existing policies, procedures and codes, and round-table discussions included the debate and resolution of specific difficulties experienced by ENSDF evaluators (i.e., all workshop participants). The contents of this report constitute a record of this workshop, based on the presentations and subsequent discussions.

  14. Systematic and Statistical Errors Associated with Nuclear Decay Constant Measurements Using the Counting Technique

    Science.gov (United States)

    Koltick, David; Wang, Haoyu; Liu, Shih-Chieh; Heim, Jordan; Nistor, Jonathan

    2016-03-01

    Typical nuclear decay constants are measured at the accuracy level of 10-2. There are numerous reasons: tests of unconventional theories, dating of materials, and long term inventory evolution which require decay constants accuracy at a level of 10-4 to 10-5. The statistical and systematic errors associated with precision measurements of decays using the counting technique are presented. Precision requires high count rates, which introduces time dependent dead time and pile-up corrections. An approach to overcome these issues is presented by continuous recording of the detector current. Other systematic corrections include, the time dependent dead time due to background radiation, control of target motion and radiation flight path variation due to environmental conditions, and the time dependent effects caused by scattered events are presented. The incorporation of blind experimental techniques can help make measurement independent of past results. A spectrometer design and data analysis is reviewed that can accomplish these goals. The author would like to thank TechSource, Inc. and Advanced Physics Technologies, LLC. for their support in this work.

  15. Particle Physics Models for the 17 MeV Anomaly in Beryllium Nuclear Decays

    CERN Document Server

    Feng, Jonathan L; Galon, Iftah; Gardner, Susan; Smolinsky, Jordan; Tait, Tim M P; Tanedo, Philip

    2016-01-01

    The 6.8$\\sigma$ anomaly in excited 8Be nuclear decays via internal pair creation is fit well by a new particle interpretation. In a previous analysis, we showed that a 17 MeV protophobic gauge boson provides a particle physics explanation of the anomaly consistent with all existing constraints. Here we begin with a review of the physics of internal pair creation in 8Be decays and the characteristics of the observed anomaly. To develop its particle interpretation, we provide an effective operator analysis for excited 8Be decays to particles with a variety of spins and parities and show that these considerations exclude simple models with scalar or pseudoscalar particles. We discuss the required couplings for a gauge boson to give the observed signal, highlighting the significant dependence on the precise mass of the boson and isospin mixing and breaking effects. We present anomaly-free extensions of the Standard Model that contain protophobic gauge bosons with the desired couplings to explain the 8Be anomaly. ...

  16. Nuclear Matrix Elements for the $\\beta\\beta$ Decay of the $^{76}$Ge

    CERN Document Server

    Brown, B A; Horoi, M

    2015-01-01

    The nuclear matrix elements for two-neutrino double-beta (2 n$\\beta\\beta$ ) and zero-neutrino double-beta (0 n$\\beta\\beta$) decay of 76 Ge are evaluated in terms of the configuration interaction (CI), quasiparticle random phase approximation (QRPA) and interacting boson model (IBM) methods. We show that the decomposition of the matrix elements in terms of interemediate states in 74 Ge is dominated by ground state of this nucleus. We consider corrections to the CI results that arise from configurations admixtures involving orbitals out-side of the CI configuration space by using results from QRPA, many-body-perturbation theory, and the connections to related observables. The CI two-neutrino matrix element is reduced due to the inclusion of spin-orbit partners, and to many-body correlations connected with Gamow-Teller beta decay. The CI zero-neutrino matrix element for the heavy neutrino is enhanced due to particle-particle correlations that are connected with the odd-even oscillations in the nuclear masse...

  17. Interaction profiling identifies the human nuclear exosome targeting complex

    DEFF Research Database (Denmark)

    Lubas, Michal Szymon; Christensen, Marianne Spangsberg; Kristiansen, Maiken Søndergaard

    2011-01-01

    of a similar activator(s) in humans remains elusive. By establishing an interaction network of the human nuclear exosome, we identify the trimeric Nuclear Exosome Targeting (NEXT) complex, containing hMTR4, the Zn-knuckle protein ZCCHC8, and the putative RNA binding protein RBM7. ZCCHC8 and RBM7 are excluded...... to nucleoli. Our results suggest that human nuclear exosome degradation pathways comprise modules of spatially organized cofactors that diverge from the yeast model....

  18. $\\beta$-asymmetry measurements in nuclear $\\beta$-decay as a probe for non-standard model physics

    CERN Multimedia

    Roccia, S

    2002-01-01

    We propose to perform a series of measurements of the $\\beta$-asymmetry parameter in the decay of selected nuclei, in order to investigate the presence of possible time reversal invariant tensor contributions to the weak interaction. The measurements have the potential to improve by a factor of about four on the present limits for such non-standard model contributions in nuclear $\\beta$-decay.

  19. Dynamics and regulation of nuclear import and nuclear movements of HIV-1 complexes

    Science.gov (United States)

    Burdick, Ryan C.; Chen, Jianbo; Sastri, Jaya; Hu, Wei-Shau

    2017-01-01

    The dynamics and regulation of HIV-1 nuclear import and its intranuclear movements after import have not been studied. To elucidate these essential HIV-1 post-entry events, we labeled viral complexes with two fluorescently tagged virion-incorporated proteins (APOBEC3F or integrase), and analyzed the HIV-1 dynamics of nuclear envelope (NE) docking, nuclear import, and intranuclear movements in living cells. We observed that HIV-1 complexes exhibit unusually long NE residence times (1.5±1.6 hrs) compared to most cellular cargos, which are imported into the nuclei within milliseconds. Furthermore, nuclear import requires HIV-1 capsid (CA) and nuclear pore protein Nup358, and results in significant loss of CA, indicating that one of the viral core uncoating steps occurs during nuclear import. Our results showed that the CA-Cyclophilin A interaction regulates the dynamics of nuclear import by delaying the time of NE docking as well as transport through the nuclear pore, but blocking reverse transcription has no effect on the kinetics of nuclear import. We also visualized the translocation of viral complexes docked at the NE into the nucleus and analyzed their nuclear movements and determined that viral complexes exhibited a brief fast phase (HIV-1 complexes quickly tether to chromatin at or near their sites of integration in both wild-type cells and cells in which LEDGF/p75 was deleted using CRISPR/cas9, indicating that the tethering interactions do not require LEDGF/p75. These studies provide novel insights into the dynamics of viral complex-NE association, regulation of nuclear import, viral core uncoating, and intranuclear movements that precede integration site selection. PMID:28827840

  20. Compilation of nuclear decay data used for dose calculations. Data for radionuclides not listed in ICRP publication 38

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Akira; Yamaguchi, Yasuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Tamura, Tsutomu

    1999-07-01

    Nuclear decay data used for dose calculations were compiled for 162 nuclides with half-lives greater than or equal to 10 min that are not listed in ICRP Publication 38 (Publ. 38) and their 28 daughter nuclides. Additional 14 nuclides that are considered to be important in fusion reactor facilities were also included. The data were compiled using decay data sets of the Evaluated Nuclear Structure Data File (ENSDF), the latest version in August 1997. Investigations of the data sets were performed to check their consistency by referring to recent literature and NUBASE, the database for nuclear and decay properties of nuclides, and by using the utility programs of ENSDF. Possible revisions of the data sets were made for their format and syntax errors, level schemes, normalization records, and so on. The revised data sets were processed by EDISTR in order to calculate the energies and intensities of {alpha} particles, {beta} particles, {gamma} rays including annihilation photons, internal conversion electrons, X rays, and Auger electrons emitted in nuclear transformations of the radionuclides. For spontaneously fissioning nuclides, the average energies and intensities of neutrons, fission fragments, prompt {gamma} rays, delayed {gamma} rays, and {beta} particles were also calculated. The compiled data were presented in two types of format; Publ. 38 and NUCDECAY formats. This report provides the decay data in the Publ. 38 format along with decay scheme drawings. The data will be widely used for internal and external dose calculations in radiation protection. (author)

  1. Nuclear β --decay half-lives for {fp} and {fpg} shell nuclei

    Science.gov (United States)

    Kumar, Vikas; Srivastava, P. C.; Li, Hantao

    2016-10-01

    In the present work we calculate the allowed {β }--decay half-lives of nuclei with Z=20-30 and N ≤slant 50 systematically under the framework of the nuclear shell model. A recent study shows that some nuclei in this region belong to the island of inversion. We perform calculation for fp shell nuclei using the KB3G effective interaction. In the case of Ni, Cu, and Zn, we used the JUN45 effective interaction. Theoretical results of Q values, half-lives, excitation energies, logft values, and branching fractions are discussed and compared with the experimental data. In the Ni region, we also compared our calculated results with recent experimental data (Xu et al 2014 Phys. Rev. Lett. 113 032505). The present results agree with the experimental data of half-lives in comparison to QRPA.

  2. Spin dipole nuclear matrix elements for double beta decay nuclei by charge-exchange reactions

    Science.gov (United States)

    Ejiri, H.; Frekers, D.

    2016-11-01

    Spin dipole (SD) strengths for double beta-decay (DBD) nuclei were studied experimentally for the first time by using measured cross sections of (3He, t) charge-exchange reactions (CERs). Then SD nuclear matrix elements (NMEs) {M}α ({{SD}}) for low-lying 2- states were derived from the experimental SD strengths by referring to the experimental α = GT (Gamow-Teller) and α = F (Fermi) strengths. They are consistent with the empirical NMEs M({{SD}}) based on the quasi-particle model with the empirical effective SD coupling constant. The CERs are used to evaluate the SD NME, which is associated with one of the major components of the neutrino-less DBD NME.

  3. Disordered nuclear pasta, magnetic field decay, and crust cooling in neutron stars

    CERN Document Server

    Horowitz, C J; Briggs, C M; Caplan, M E; Cumming, A; Schneider, A S

    2014-01-01

    Nuclear pasta, with non-spherical shapes, is expected near the base of the crust in neutron stars. Large scale molecular dynamics simulations of pasta show long lived topological defects that could increase electron scattering and reduce both the thermal and electrical conductivities. We model a possible low conductivity pasta layer by increasing an impurity parameter Q_{imp}. Predictions of light curves for the low mass X-ray binary MXB 1659-29, assuming a large Q_{imp}, find continued late time cooling that is consistent with Chandra observations. The electrical and thermal conductivities are likely related. Therefore observations of late time crust cooling can provide insight on the electrical conductivity and the possible decay of neutron star magnetic fields (assuming these are supported by currents in the crust).

  4. Testing CVC and CKM Unitarity via Sup erallowed Nuclear Beta Decay

    Institute of Scientific and Technical Information of China (English)

    J. C. Hardy; I. S. Towner

    2016-01-01

    Superallowed nuclear beta decay between 0+ analog states is a sensitive probe of the weak interaction, with the established strength–or Ft value–of each such transition being a direct measure of the vector coupling constant, GV. Each transition’s Ft value depends on the half-life of the parent nucleus as well as on the Q-value and branching ratio for the transition of interest. It also depends on small (∼1%) transition-dependent theoretical corrections, of which the most sensitive accounts for isospin symmetry breaking. We have recently published a new survey of world superallowed-decay data, which establishes the Ft values of 14 separate superallowed transitions to a precision of order 0.1% or better. The results from this very robust data set yield the value of Vud , the up-down quark mixing element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix, and lead to the most demanding test available of CKM unitarity. The survey results and their outcome are described, as is the current direction of experiments that focus on testing the validity of the isospin-symmetry-breaking corrections.

  5. A decay estimate for a wave equation with trapping and a complex potential

    CERN Document Server

    Andersson, Lars; Nicolas, Jean-Philippe

    2011-01-01

    In this brief note, we consider a wave equation that has both trapping and a complex potential. For this problem, we prove a uniform bound on the energy and a Morawetz (or integrated local energy decay) estimate. The equation is a model problem for certain scalar equations appearing in the Maxwell and linearised Einstein systems on the exterior of a rotating black hole.

  6. Studying Nuclear Receptor Complexes in the Cellular Environment.

    Science.gov (United States)

    Schaufele, Fred

    2016-01-01

    The ligand-regulated structure and biochemistry of nuclear receptor complexes are commonly determined by in vitro studies of isolated receptors, cofactors, and their fragments. However, in the living cell, the complexes that form are governed not just by the relative affinities of isolated cofactors for the receptor but also by the cell-specific sequestration or concentration of subsets of competing or cooperating cofactors, receptors, and other effectors into distinct subcellular domains and/or their temporary diversion into other cellular activities. Most methods developed to understand nuclear receptor function in the cellular environment involve the direct tagging of the nuclear receptor or its cofactors with fluorescent proteins (FPs) and the tracking of those FP-tagged factors by fluorescence microscopy. One of those approaches, Förster resonance energy transfer (FRET) microscopy, quantifies the transfer of energy from a higher energy "donor" FP to a lower energy "acceptor" FP attached to a single protein or to interacting proteins. The amount of FRET is influenced by the ligand-induced changes in the proximities and orientations of the FPs within the tagged nuclear receptor complexes, which is an indicator of the structure of the complexes, and by the kinetics of the interaction between FP-tagged factors. Here, we provide a guide for parsing information about the structure and biochemistry of nuclear receptor complexes from FRET measurements in living cells.

  7. Nuclear parameters determination of the {sup 127}Te {beta} {sup -} decay: a proposal for teaching nuclear physics; Determinacao de parametros nucleares do nucleo de {sup 127}Te: uma proposta para o ensino de fisica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Wagner Fonseca

    2011-07-01

    A study of the {sup 127}Te {beta}{sup -} decay was carried out by means of gamma spectroscopy measurements using high resolution HPGe detector, in the region from 30 keV to 1.0 MeV, aiming to get a better understanding of the {sup 127}Te nuclear structure. The radioactive sources of {sup 12}7Te were obtained from the {sup 126}Te(n,{gamma}){sup 1}'2{sup 7}Te nuclear reaction produced in the IEA- R1 nuclear reactor at IPEN/CNEN-SP. Five gamma {sup t}ransitions previously attributed to this decay were confirmed with a better precision than previously. The half-life of {sup 127}Te was also studied resulting in data with lower uncertainty. Using a set of data selected from gamma spectroscopy measurements was developed and applied a didactic proposal for high school students using the Excel software. (author)

  8. The limits of the nuclear chart set by fission and alpha decay

    Science.gov (United States)

    Möller, Peter

    2016-12-01

    I will review how our picture of heavy-element nuclear structure has evolved through remarkably simple ideas and related models. It is well known that the Bethe-Weizsäcker semi-empirical mass model had an important role in unraveling radioactive decay and element transmutation in the heavy-element region in the 1930s. A remarkable aspect is that this model could immediately after the discovery of fission be generalized to explain this phenomenon through the consideration of deformation of a charged liquid drop. Bethe and Bacher already raised the possibility that shell structure (by them calculated in terms of a single-particle oscillator potential) could give rise to noticeable deviations between results of the macroscopic mass model and experiment but limited data prevented firm conclusions. In the 1950s the single-particle models took a realistic form and also included deformation. The possibility of the existence of a relatively stable "island" of superheavy elements was raised already then. But it was not until the work by Strutinsky in the mid 1960s that a quantitative model for the nuclear potential-energy emerged in the form of the macroscopic-microscopic model. Although new elements have been discovered at an almost steady pace since 1940, theory indicates that we are close to the end of this era: repulsive Coulomb effects will set the limit of observable elements to near Z = 120.

  9. Neutron activation analysis via nuclear decay kinetics using gamma-ray spectroscopy at SFU

    Science.gov (United States)

    Domingo, Thomas; Chester, Aaron; Starosta, Krzysztof; Williams, Jonathan

    2016-09-01

    Gamma-ray spectroscopy is a powerful tool used in a variety of fields including nuclear and analytical chemistry, environmental science, and health risk management. At SFU, the Germanium detector for Elemental Analysis and Radiation Studies (GEARS), a low-background shielded high-purity germanium gamma-ray detector, has been used recently in all of the above fields. The current project aims to expand upon the number of applications for which GEARS can be used while enhancing its current functionality. A recent addition to the SFU Nuclear Science laboratory is the Thermo Scientific P 385 neutron generator. This device provides a nominal yield of 3 ×108 neutrons/s providing the capacity for neutron activation analysis, opening a major avenue of research at SFU which was previously unavailable. The isotopes created via neutron activation have a wide range of half-lives. To measure and study isotopes with half-lives above a second, a new analogue data acquisition system has been installed on GEARS allowing accurate measurements of decay kinetics. This new functionality enables identification and quantification of the products of neutron activation. Results from the neutron activation analysis of pure metals will be presented.

  10. The limits of the nuclear chart set by fission and alpha decay

    Directory of Open Access Journals (Sweden)

    Möller Peter

    2016-01-01

    Full Text Available I will review how our picture of heavy-element nuclear structure has evolved through remarkably simple ideas and related models. It is well known that the Bethe-Weizsäcker semi-empirical mass model had an important role in unraveling radioactive decay and element transmutation in the heavy-element region in the 1930s. A remarkable aspect is that this model could immediately after the discovery of fission be generalized to explain this phenomenon through the consideration of deformation of a charged liquid drop. Bethe and Bacher already raised the possibility that shell structure (by them calculated in terms of a single-particle oscillator potential could give rise to noticeable deviations between results of the macroscopic mass model and experiment but limited data prevented firm conclusions. In the 1950s the single-particle models took a realistic form and also included deformation. The possibility of the existence of a relatively stable “island” of superheavy elements was raised already then. But it was not until the work by Strutinsky in the mid 1960s that a quantitative model for the nuclear potential-energy emerged in the form of the macroscopic-microscopic model. Although new elements have been discovered at an almost steady pace since 1940, theory indicates that we are close to the end of this era: repulsive Coulomb effects will set the limit of observable elements to near Z = 120.

  11. Nuclear organization of the rock hyrax (Procavia capensis) amygdaloid complex.

    Science.gov (United States)

    Limacher-Burrell, Aude-Marie; Bhagwandin, Adhil; Gravett, Nadine; Maseko, Busisiwe C; Manger, Paul R

    2016-07-01

    The current study details the nuclear organization of the rock hyrax amygdaloid complex using both Nissl and myelin stains, along with a range of immunohistochemical stains. The rock hyrax appears to be the least derived of the Afrotherians, a group with a huge range of body phenotypes, life histories and specialized behaviours, brain sizes, and ecological niches. In this sense, the rock hyrax represents a species where the organization of the amygdaloid complex may be reflective of that in stem Eutherian mammals. Our analysis indicates that the nuclear organization of the rock hyrax amygdaloid complex is indeed very similar to that in other mammals studied, with four major nuclear groupings (the deep or basolateral group; the superficial or cortical-like or corticomedial group; the centromedial group; and the other amygdaloid nuclei) being observed, which is typical of Eutherian mammals. Moreover, each of these groupings is composed of several nuclei, the vast majority of which were readily identified in the rock hyrax. Small nuclei identified in rodents and primates were absent in the superficial and centromedial groups, seemingly involved with olfaction. A novel shell-like nucleus of the accessory basal nuclear cluster was observed in the rock hyrax, again, likely to be involved in olfaction. The current study underlines the conserved nature of nuclear parcellation in the Eutherian mammal amygdaloid complex and indicates that across most species, the flow of information processing related to species-specific affective-laden stimuli and the resultant physiological and behavioural outcomes are likely to be similar across species.

  12. In situ structural analysis of the human nuclear pore complex.

    Science.gov (United States)

    von Appen, Alexander; Kosinski, Jan; Sparks, Lenore; Ori, Alessandro; DiGuilio, Amanda L; Vollmer, Benjamin; Mackmull, Marie-Therese; Banterle, Niccolo; Parca, Luca; Kastritis, Panagiotis; Buczak, Katarzyna; Mosalaganti, Shyamal; Hagen, Wim; Andres-Pons, Amparo; Lemke, Edward A; Bork, Peer; Antonin, Wolfram; Glavy, Joseph S; Bui, Khanh Huy; Beck, Martin

    2015-10-01

    Nuclear pore complexes are fundamental components of all eukaryotic cells that mediate nucleocytoplasmic exchange. Determining their 110-megadalton structure imposes a formidable challenge and requires in situ structural biology approaches. Of approximately 30 nucleoporins (Nups), 15 are structured and form the Y and inner-ring complexes. These two major scaffolding modules assemble in multiple copies into an eight-fold rotationally symmetric structure that fuses the inner and outer nuclear membranes to form a central channel of ~60 nm in diameter. The scaffold is decorated with transport-channel Nups that often contain phenylalanine-repeat sequences and mediate the interaction with cargo complexes. Although the architectural arrangement of parts of the Y complex has been elucidated, it is unclear how exactly it oligomerizes in situ. Here we combine cryo-electron tomography with mass spectrometry, biochemical analysis, perturbation experiments and structural modelling to generate, to our knowledge, the most comprehensive architectural model of the human nuclear pore complex to date. Our data suggest previously unknown protein interfaces across Y complexes and to inner-ring complex members. We show that the transport-channel Nup358 (also known as Ranbp2) has a previously unanticipated role in Y-complex oligomerization. Our findings blur the established boundaries between scaffold and transport-channel Nups. We conclude that, similar to coated vesicles, several copies of the same structural building block--although compositionally identical--engage in different local sets of interactions and conformations.

  13. gA-driven shapes of electron spectra of forbidden β decays in the nuclear shell model

    Science.gov (United States)

    Kostensalo, Joel; Suhonen, Jouni

    2017-08-01

    The evolution of the shape of the electron spectra of 16 forbidden β- decays as a function of gA was studied using the nuclear shell model in appropriate single-particle model spaces with established, well-tested nuclear Hamiltonians. The β spectra of 94Nb(6+) →94Mo(4+) and 98Tc(6+) →98Ru(4+) were found to depend strongly on gA, which makes them excellent candidates for the determination of the effective value of gA with the spectrum-shape method (SSM). A strong gA dependence is also seen in the spectrum of 96Zr(0+) →96Nb(6+) . This decay could be used for determining the quenching of gA in sixth-forbidden decays in the future, when the measurement of the spectrum becomes experimentally feasible. The calculated shell-model electron spectra of the ground-state-to-ground-state decays of 87Rb, 99Tc, and 137Cs and the decay of 137Cs to the isomeric 11 /2- state in 137Ba were found to be in excellent agreement with the spectra previously calculated using the microscopic quasiparticle-phonon model. This is further evidence of the robust nature of the SSM observed in the previous studies.

  14. The Decay of Communism: Managing Spent Nuclear Fuel in the Soviet Union, 1937-1991

    Energy Technology Data Exchange (ETDEWEB)

    Hoegselius, Per (History of Science and Technology, Royal Inst. of Technology, Stockholm (Sweden)), e-mail: perho@kth.se

    2010-09-15

    The historical evolution of spent nuclear fuel (SNF) decision-making in Western Europe and North America is already fairly well-known. For the former socialist countries of Eastern Europe, and in particular the Soviet Union, we know less. There have recently been several good studies of Soviet nuclear power history (e.g. Schmid 2004, 2006, Josephson 2005), but none of them has gone into any depth when it comes to SNF, but rather focused on nuclear power reactors, public acceptance, the role of the media, etc. There are also several good overviews available that problematize the radioactive legacy of the Soviet Union, including the SNF and waste issue, but these studies do not address the historical dynamics and evolution of SNF management over a longer period of time; in other words, they fail to explain how and why the present state of affairs have actually come into being. The aim of this paper is to provide historical insight into the dynamics of SNF decision-making in the Soviet Union, from the origins of nuclear engineering in the 1930s to the collapse of the country in 1991. The nuclear fuel system can be described as a large technical system with a variety of interrelated components. The system is 'large' both because it involves key links between geographically disperse activities, and because it involves a variety of technologies, organizations and people that influence the dynamics and evolution of the system. Soviet SNF history is of particular interest in this context, with a nuclear fuel system that was the most complex in the world. The USSR was a pioneer within nuclear power and developed a variety of reactor designs and technologies for uranium mining, conversion and enrichment, as well as for transport, treatment, storage and reprocessing of spent nuclear fuel. It explored both military and civil uses of the atom, and an enormous amount of people and organizations were involved in realizing highly ambitious nuclear programmes. The USSR is

  15. Decay of Activity Complexes, Formation of Unipolar Magnetic Regions and Coronal Holes in their Causal Relation

    CERN Document Server

    Golubeva, Elena

    2016-01-01

    North-south asymmetry of sunspot activity resulted in an asynchronous reversal of the Sun's polar fields in the current cycle. The asymmetry is also observed in the formation of polar coronal holes. A stable coronal hole was first formed at the South Pole, despite the later polar-field reversal there. The aim of this study is to understand processes making this situation possible. Synoptic magnetic maps from the Global Oscillation Network Group and corresponding coronal-hole maps from the Extreme ultraviolet Imaging Telescope aboard the Solar and Heliospheric Observatory and the Atmospheric Imaging Assembly aboard the Solar Dynamics Observatory are analyzed here to study a causal relationship between the decay of activity complexes, evolution of large-scale magnetic fields, and formation of coronal holes. Ensembles of coronal holes associated with decaying active regions and activity complexes are presented. These ensembles take part in global rearrangements of the Sun's open magnetic flux. In particular, the...

  16. Decay of Activity Complexes, Formation of Unipolar Magnetic Regions, and Coronal Holes in Their Causal Relation

    Science.gov (United States)

    Golubeva, E. M.; Mordvinov, A. V.

    2016-12-01

    The peculiar development of solar activity in the current cycle resulted in an asynchronous reversal of the Sun's polar fields. The asymmetry is also observed in the formation of polar coronal holes. A stable coronal hole was first formed at the South Pole, despite the later polar-field reversal there. The aim of this study is to understand the processes making this situation possible. Synoptic magnetic maps from the Global Oscillation Network Group and corresponding coronal-hole maps from the Extreme ultraviolet Imaging Telescope onboard the Solar and Heliospheric Observatory and the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory are analyzed here to study the causal relationship between the decay of activity complexes, evolution of large-scale magnetic fields, and formation of coronal holes. Ensembles of coronal holes associated with decaying active regions and activity complexes are presented. These ensembles take part in global rearrangements of the Sun's open magnetic flux. In particular, the south polar coronal hole was formed from an ensemble of coronal holes that came into existence after the decay of multiple activity complexes observed during 2014.

  17. The Structure Inventory of the Nuclear Pore Complex.

    Science.gov (United States)

    Schwartz, Thomas U

    2016-05-22

    The nuclear pore complex (NPC) is the principal gateway for molecular exchange between nucleus and cytoplasm across the nuclear envelope. Due to its sheer size of estimated 50-112MDa and its complex buildup from about 500-1000 individual proteins, it is a difficult object to study for structural biologists. Here, I review the extensive ensemble of high-resolution structures of the building blocks of the NPC. Concurrent with the increase in size and complexity, these latest, large structures and assemblies can now be used as the basis for hybrid approaches, primarily in combination with cryo-electron microscopic analysis, generating the first structure-based assembly models of the NPC. Going forward, the structures will be critically important for a detailed analysis of the NPC, including function, evolution, and assembly.

  18. Excited state decay of cyclometalated polypyridine ruthenium complexes: insight from theory and experiment.

    Science.gov (United States)

    Kreitner, Christoph; Heinze, Katja

    2016-09-21

    Deactivation pathways of the triplet metal-to-ligand charge transfer ((3)MLCT) excited state of cyclometalated polypyridine ruthenium complexes with [RuN5C](+) coordination are discussed on the basis of the available experimental data and a series of density functional theory calculations. Three different complex classes are considered, namely with [Ru(N^N)2(N^C)](+), [Ru(N^N^N)(N^C^N)](+) and [Ru(N^N^N)(N^N^C)](+) coordination modes. Excited state deactivation in these complex types proceeds via five distinct decay channels. Vibronic coupling of the (3)MLCT state to high-energy oscillators of the singlet ground state ((1)GS) allows tunneling to the ground state followed by vibrational relaxation (path A). A ligand field excited state ((3)MC) is thermally accessible via a (3)MLCT →(3)MC transition state with the (3)MC state being strongly coupled to the (1)GS surface via a low-energy minimum energy crossing point (path B). Furthermore, a (3)MLCT →(1)GS surface crossing point directly couples the triplet and singlet potential energy surfaces (path C). Charge transfer states either with higher singlet character or with different orbital parentage and intrinsic symmetry restrictions are thermally populated which promote non-radiative decay via tunneling to the (1)GS state (path D). Finally, the excited state can decay via phosphorescence (path E). The dominant deactivation pathways differ for the three individual complex classes. The implications of these findings for isoelectronic iridium(iii) or iron(ii) complexes are discussed. Ultimately, strategies for optimizing the emission efficiencies of cyclometalated polypyridine complexes of d(6)-metal ions, especially Ru(II), are suggested.

  19. Two decay paths for calculation of nuclear matrix element of neutrinoless double-beta decay using quasiparticle random-phase approximation

    CERN Document Server

    Terasaki, Jun

    2015-01-01

    It is possible to employ virtual decay paths, including two-particle transfer, to calculate the nuclear matrix element of neutrinoless double-beta decay under the closure approximation, in addition to the true double-beta path. In the quasiparticle random-phase approximation (QRPA) approach, it is necessary to introduce the product wave functions of the like-particle and proton-neutron QRPA ground states, for achieving consistency between the calculations of the true and virtual paths. Using these different paths, the problem of whether or not these two methods give equivalent nuclear matrix elements (NME) is investigated. It is found that the two results are inequivalent, resulting from the different many-body correlations included in the two QRPA methods, i.e., the use of the product wave functions alone is not sufficient. The author proposes introduction of the proton-neutron pairing interaction with an adequate strength in the double-beta-path method, which carries less many-body correlations without this...

  20. A new scanning system for alpha decay events as calibration sources for range-energy relation in nuclear emulsion

    Science.gov (United States)

    Yoshida, J.; Kinbara, S.; Mishina, A.; Nakazawa, K.; Soe, M. K.; Theint, A. M. M.; Tint, K. T.

    2017-03-01

    A new scanning system named "Vertex picker" has been developed to rapid collect alpha decay events, which are calibration sources for the range-energy relation in nuclear emulsion. A computer-controlled optical microscope scans emulsion layers exhaustively, and a high-speed and high-resolution camera takes their micrographs. A dedicated image processing picks out vertex-like shapes. Practical operations of alpha decay search were demonstrated by emulsion sheets of the KEK-PS E373 experiment. Alpha decays of nearly 28 events were detected in eye-check work on a PC monitor per hour. This yield is nearly 20 times more effective than that by the conventional eye-scan method. The speed and quality is acceptable for the coming new experiment, J-PARC E07.

  1. Complex organizations: the case of the Brazilian nuclear sector

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, Roberto Salles [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao-Geral de Planejamento e Avaliacao], e-mail: xavier@cnen.gov.br

    2009-07-01

    The resumption of the Brazilian Nuclear Program (BNP), in the proposed size and after 20 years of paralysis, requires profound changes in the current organizational modeling of the national nuclear industry. The effectiveness of any process of organizational change is limited to three factors. The theoretical bottleneck happens when you do not know enough about a phenomenon in order to effect the desired changes. The resource bottleneck occurs when knowledge may be available to change people's behavior but the funds necessary for implementation may be lacking. The organizational bottleneck emerges when there are knowledge and resources to solve a problem, but may not able to organize the resources in order to carry out the problem-solving effort. In the case of resumption of BNP seems clear that there is the knowledge of what is needed to make policy and the intention to allocate the necessary resources. But the question is the following: the current organizational model of the Brazilian nuclear sector is consistent with the goals laid down in the scenario of resumption of BNP? That is, is there organizational ability to leverage a program of the size proposed for the nuclear area? Find answers to these questions is crucial, because the organizational model of the Brazilian nuclear sector consists of elements involving a complex interorganizational system. Thus, this article is to examine the appropriateness of the current organizational modeling of the Brazilian nuclear sector to current demands of society. As a result, the article aims to propose recommendations for a remodeling of the nuclear sector, taking into account the current national and international scenarios of nuclear energy. (author)

  2. Comparative anatomy of the vestibular nuclear complex in submammalian vertebrates.

    Science.gov (United States)

    Mehler, W. R.

    1972-01-01

    A synopsis of the literature on the natural history of the vestibular nuclear complex (VNC) in lower vertebrates is presented in an attempt to assess the knowledge available. The review discloses that there is considerable descriptive information that is widely dispersed in the literature. However, information about the topology, number, and cellular composition of the cell groups that compose the VNC is sketchy. Major cytological and hodological information is still needed to establish which parts of the VNC actually are homologous.

  3. Complex signal amplitude analysis for complete fusion nuclear reaction products

    CERN Document Server

    Tsyganov, Yu S

    2015-01-01

    A complex analysis has been performed on the energy amplitude signals corresponding to events of Z=117 element measured in the 249Bk+48Ca complete fusion nuclear reaction. These signals were detected with PIPS position sensitive detector. The significant values of pulse height defect both for recoils (ER) and fission fragments (FF) were measured. Comparison with the computer simulations and empirical formulae has been performed both for ER and FF signals.

  4. Automated quantification of nuclear immunohistochemical markers with different complexity.

    Science.gov (United States)

    López, Carlos; Lejeune, Marylène; Salvadó, María Teresa; Escrivà, Patricia; Bosch, Ramón; Pons, Lluis E; Alvaro, Tomás; Roig, Jordi; Cugat, Xavier; Baucells, Jordi; Jaén, Joaquín

    2008-03-01

    Manual quantification of immunohistochemically stained nuclear markers is still laborious and subjective and the use of computerized systems for digital image analysis have not yet resolved the problems of nuclear clustering. In this study, we designed a new automatic procedure for quantifying various immunohistochemical nuclear markers with variable clustering complexity. This procedure consisted of two combined macros. The first, developed with a commercial software, enabled the analysis of the digital images using color and morphological segmentation including a masking process. All information extracted with this first macro was automatically exported to an Excel datasheet, where a second macro composed of four different algorithms analyzed all the information and calculated the definitive number of positive nuclei for each image. One hundred and eighteen images with different levels of clustering complexity was analyzed and compared with the manual quantification obtained by a trained observer. Statistical analysis indicated a great reliability (intra-class correlation coefficient > 0.950) and no significant differences between the two methods. Bland-Altman plot and Kaplan-Meier curves indicated that the results of both methods were concordant around 90% of analyzed images. In conclusion, this new automated procedure is an objective, faster and reproducible method that has an excellent level of accuracy, even with digital images with a high complexity.

  5. Density Dependence of the Mass and Decay Constant of Pion in Nuclear Matter in the Dyson-Schwinger Equation Approach of QCD

    Institute of Scientific and Technical Information of China (English)

    LIU Yu-Xin; CHAO Jing-Yi; CHANG Lei; YUAN Wei

    2005-01-01

    @@ With the Dyson-Schwinger equation formalism at finite chemical potential, we study the density dependence of the mass and decay constant of pion in nuclear matter. The calculated results indicate that both the mass and the decay constant remain almost constant at small chemical potential. As the chemical potential gets quite large, the decay constant increases and the mass decreases with the increasing of the chemical potential, and both of them vanish suddenly as a critical value is reached.

  6. Crystal Structure of the Herpesvirus Nuclear Egress Complex Provides Insights into Inner Nuclear Membrane Remodeling

    Directory of Open Access Journals (Sweden)

    Tzviya Zeev-Ben-Mordehai

    2015-12-01

    Full Text Available Although nucleo-cytoplasmic transport is typically mediated through nuclear pore complexes, herpesvirus capsids exit the nucleus via a unique vesicular pathway. Together, the conserved herpesvirus proteins pUL31 and pUL34 form the heterodimeric nuclear egress complex (NEC, which, in turn, mediates the formation of tight-fitting membrane vesicles around capsids at the inner nuclear membrane. Here, we present the crystal structure of the pseudorabies virus NEC. The structure revealed that a zinc finger motif in pUL31 and an extensive interaction network between the two proteins stabilize the complex. Comprehensive mutational analyses, characterized both in situ and in vitro, indicated that the interaction network is not redundant but rather complementary. Fitting of the NEC crystal structure into the recently determined cryoEM-derived hexagonal lattice, formed in situ by pUL31 and pUL34, provided details on the molecular basis of NEC coat formation and inner nuclear membrane remodeling.

  7. Nuclear spectroscopy

    CERN Document Server

    Ajzenberg-Selove, Fay

    1960-01-01

    Nuclear Spectroscopy, Part B focuses on the ways in which experimental data may be analyzed to furnish information about nuclear parameters and nuclear models in terms of which the data are interpreted.This book discusses the elastic and inelastic potential scattering amplitudes, role of beta decay in nuclear physics, and general selection rules for electromagnetic transitions. The nuclear shell model, fundamental coupling procedure, vibrational spectra, and empirical determination of the complex potential are also covered. This publication is suitable for graduate students preparing for exper

  8. Analysis of Experiments Exhibiting Time-Varying Nuclear Decay Rates: Systematic Effects or New Physics?

    CERN Document Server

    Jenkins, Jere H; Sturrock, Peter A; Mundy, Daniel W

    2011-01-01

    Since the 1930s, and with very few exceptions, it has been assumed that the process of radioactive decay is a random process, unaffected by the environment in which the decaying nucleus resides. There have been instances within the past few decades, however, where changes in the chemical environment or physical environment brought about small changes in the decay rates. But even in light of these instances, decaying nuclei that were undisturbed or un-"pressured" were thought to behave in the expected random way, subject to the normal decay probabilities which are specific to each nuclide. Moreover, any "non-random" behavior was assumed automatically to be the fault of the detection systems, the environment surrounding the detectors, or changes in the background radiation to which the detector was exposed. Recently, however, evidence has emerged from a variety of sources, including measurements taken by independent groups at Brookhaven National Laboratory, Physikalisch-Technische Bundesanstalt, and Purdue Univ...

  9. Isotensor Axial Polarizability and Lattice QCD Input for Nuclear Double- β Decay Phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Shanahan, Phiala E.; Tiburzi, Brian C.; Wagman, Michael L.; Winter, Frank; Chang, Emmanuel; Davoudi, Zohreh; Detmold, William; Orginos, Kostas; Savage, Martin J.

    2017-08-01

    The potential importance of short-distance nuclear effects in double-$\\beta$ decay is assessed using a lattice QCD calculation of the $nn\\rightarrow pp$ transition and effective field theory methods. At the unphysical quark masses used in the numerical computation, these effects, encoded in the isotensor axial polarisability, are found to be of similar magnitude to the nuclear modification of the single axial current, which phenomenologically is the quenching of the axial charge used in nuclear many-body calculations. This finding suggests that nuclear models for neutrinoful and neutrinoless double-$\\beta$ decays should incorporate this previously neglected contribution if they are to provide reliable guidance for next-generation neutrinoless double-$\\beta$ decay searches. The prospects of constraining the isotensor axial polarisabilities of nuclei using lattice QCD input into nuclear many-body calculations are discussed.

  10. Primary Biliary Cirrhosis and the Nuclear Pore Complex

    Science.gov (United States)

    Duarte-Rey, Carolina; Bogdanos, Dimitrios; Yang, Chen-Yen; Roberts, Krista; Leung, Patrick S.C.; Anaya, Juan-Manuel; Worman, Howard J.; Gershwin, M. Eric

    2012-01-01

    Experimental models of autoimmune diseases have led to the conclusion that an immune response to nuclear antigens is a sentinel marker for loss of tolerance and potential tissue damage. Various proteins are targets of antinuclear antibodies in a variety of autoimmune diseases, ranging from systemic rheumatologic disorders to diseases affecting specific organs such as the liver. Autoantibodies against specific nuclear constituents have also been used as probes to understand the structure and the function of the targeted components and their relevance to disease pathogenesis. Approximately a quarter of patients with primary biliary cirrhosis (PBC) have antibodies targeting proteins of the nuclear pore complex (NPC), a multi-protein structure that mediates molecular transport across the nuclear envelope. Autoantibodies against the integral membrane glycoprotein gp210 and nucleoporin p62 appear to be highly specific for PBC, an autoimmune disease characterized by progressive destruction of intrahepatic biliary epithelial cells. This review discusses the diagnostic and clinical relevance of anti-NPC antibodies in PBC and the possibility that this autoimmune response may arise as a result of molecular mimicry. PMID:22487189

  11. Performance demonstration of 4πβ(LS)-γ coincidence counting system for standardization of radionuclides with complex decay scheme.

    Science.gov (United States)

    Kulkarni, D B; Anuradha, R; Joseph, Leena; Kulkarni, M S; Tomar, B S

    2016-02-01

    A standardization of (134)Cs and (131)I was carried out in order to demonstrate the performance and applicability of the 4πβ(LS)-γ coincidence counting system for standardization of radionuclides with complex decay scheme. The coincidence analyzer, capable of analyzing coincidence between beta and two gamma windows simultaneously, was developed and used for the standardization. The use of this dual coincidence analyzer has reduced the total experimental time by half. The activity concentrations obtained using the 4πβ(LS)-γ coincidence counting system, a 4πβ(PC)-γ coincidence counting system, and the CIEMAT/NIST method are in excellent agreement with each other within uncertainty limits and hence demonstrates its performance for standardization of radionuclides decaying with complex decay scheme. Hence use of this 4πβ(LS)-γ coincidence counting system can be an alternative method suitable to standardize radionuclides with complex decay scheme with acceptable precision.

  12. Chlorine Nuclear Quadrupole Hyperfine Structure in the Vinyl - Chloride Complex

    Science.gov (United States)

    Leung, Helen O.; Marshall, Mark D.; Messinger, Joseph P.

    2015-06-01

    The microwave spectrum of the vinyl chloride--hydrogen chloride complex, presented at last year's symposium, is greatly complicated by the presence of two chlorine nuclei as well as an observed, but not fully explained tunneling motion. Indeed, although it was possible at that time to demonstrate conclusively that the complex is nonplanar, the chlorine nuclear quadrupole hyperfine splitting in the rotational spectrum resisted analysis. With higher resolution, Balle-Flygare Fourier transform microwave spectra, the hyperfine structure has been more fully resolved, but appears to be perturbed for some rotational transitions. It appears that knowledge of the quadrupole coupling constants will provide essential information regarding the structure of the complex, specifically the location of the hydrogen atom in HCl. Our progress towards obtaining values for these constants will be presented.

  13. AIDA: A 16-channel amplifier ASIC to read out the advanced implantation detector array for experiments in nuclear decay spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Braga, D. [STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX (United Kingdom); Coleman-Smith, P. J. [STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Davinson, T. [Dept. of Physics and Astronomy, Univ. of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); Lazarus, I. H. [STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Page, R. D. [Dept. of Physics, Univ. of Liverpool, Oliver Lodge Laboratory, Liverpool L69 7ZE (United Kingdom); Thomas, S. [STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX (United Kingdom)

    2011-07-01

    We have designed a read-out ASIC for nuclear decay spectroscopy as part of the AIDA project - the Advanced Implantation Detector Array. AIDA will be installed in experiments at the Facility for Antiproton and Ion Research in GSI, Darmstadt. The AIDA ASIC will measure the signals when unstable nuclei are implanted into the detector, followed by the much smaller signals when the nuclei subsequently decay. Implant energies can be as high as 20 GeV; decay products need to be measured down to 25 keV within just a few microseconds of the initial implants. The ASIC uses two amplifiers per detector channel, one covering the 20 GeV dynamic range, the other selectable over a 20 MeV or 1 GeV range. The amplifiers are linked together by bypass transistors which are normally switched off. The arrival of a large signal causes saturation of the low-energy amplifier and a fluctuation of the input voltage, which activates the link to the high-energy amplifier. The bypass transistors switch on and the input charge is integrated by the high-energy amplifier. The signal is shaped and stored by a peak-hold, then read out on a multiplexed output. Control logic resets the amplifiers and bypass circuit, allowing the low-energy amplifier to measure the subsequent decay signal. We present simulations and test results, demonstrating the AIDA ASIC operation over a wide range of input signals. (authors)

  14. Nuclear levels and structure from the decays of 213Bi and 209Tl

    Science.gov (United States)

    Ardisson, G.; Barci, V.; El Samad, O.

    1998-02-01

    Direct γ and γ-γ coincidence spectra of pure 209Tl and 213Bi sources obtained by radiochemical continuous separation were measured with coaxial and planar HPGe detectors. In 209Tl the half-life was measured, the β-decay energies and intensities of 11 γ transitions were reported, and a new decay scheme was proposed. In 213Bi β decay 22 transitions were observed, of which 18 were assigned to a new 213Po level scheme accounting for 9 excited states.

  15. Size and complexity of the nuclear genome of Colletotrichum graminicola.

    Science.gov (United States)

    Randhir, R J; Hanau, R M

    1997-10-01

    DNA reassociation was used to estimate GC content, size, and complexity of the nuclear genomes of Colletotrichum from maize and sorghum. Melting-temperature analysis indicated that the GC content of the maize pathotype DNA was 51% and that the GC content of the sorghum pathotype was 52%. DNA reassociation kinetics employing S1 nuclease digestion and an appropriately modified second-order equation indicated that the genome sizes of the maize and sorghum pathotypes were 4.8 x 10(7) bp, and 5.0 x 10(7) bp, respectively. Genomic reconstruction experiments based on Southern blot hybridization between a cloned single-copy gene, PYR1 (orotate phosphoribosyl transferase), and maize-pathotype DNA confirmed the size of the nuclear genome. The single-copy component of the genomes of both pathotypes was estimated at about 90%. For both pathotypes, ca. 7% of the genome represented repetitive DNA, and 2 to 3% was foldback DNA.

  16. Development of liquid scintillator containing a zirconium complex for neutrinoless double beta decay experiment

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Yoshiyuki, E-mail: fukuda@staff.miyakyo-u.ac.jp [Department of Physics, Miyagi University of Education, Sendai, Miyagi 980-0845 (Japan); Moriyama, Shigetaka [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Hida, Gifu 506-1205 (Japan); Ogawa, Izumi [Faculty of Engineering, Fukui University, Fukui-shi, Fukui 910-8507 (Japan)

    2013-12-21

    An organic liquid scintillator containing a zirconium complex has been developed for a new neutrinoless double beta decay experiment. In order to produce a detector that has good energy resolution (4% at 2.5 MeV) and low background (0.1counts/(t·year)) and that can monitor tons of target isotope, we chose a zirconium β-diketone complex having high solubility (over 10 wt%) in anisole. However, the absorption peak of the diketone ligand overlaps with the luminescence of anisole. Therefore, the light yield of the liquid scintillator decreases in proportion to the concentration of the complex. To avoid this problem, we synthesized a β-keto ester complex introducing –OC{sub 3}H{sub 7} or –OC{sub 2}H{sub 5} substituent groups in the β-diketone ligand, which shifted the absorption peak to around 245 nm, which is shorter than the emission peak of anisole (275 nm). However, the shift of the absorption peak depends on the polarity of the scintillation solvent. Therefore we must choose a low polarity solvent for the liquid scintillator. We also synthesized a Zr–ODZ complex, which has a high quantum yield (30%) and good emission wavelength (425 nm) with a solubility 5 wt% in benzonitrile. However, the absorption peak of the Zr–ODZ complex was around 240 nm. Therefore, it is better to use the scintillation solvent which has shorter luminescence wavelength than that of the aromatic solvent.

  17. Constraining spacetime variations of nuclear decay rates from light curves of type Ia supernovae

    CERN Document Server

    Karpikov, Ivan; Troitsky, Sergey

    2015-01-01

    The luminosity of fading type Ia supernovae is governed by radioactive decays of 56Ni and 56Co. The decay rates are proportional to the Fermi coupling constant G_F and, therefore, are determined by the vacuum expectation value v of the Brout--Englert--Higgs field. We use the publicly available SNLS and UNION2.1 sets of light curves of type Ia supernova at various redshifts to constrain possible spacetime variations of the 56Ni decay rate. The resulting constraint is not very tight; however, it is the only direct bound on the variation of the decay rate for redshifts up to z~1. We discuss potential applications of the result to searches for non-constancy of G_F and v.

  18. Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators; Summary Report of an IAEA Technical Meeting

    Energy Technology Data Exchange (ETDEWEB)

    Abriola, D.; Tuli, J.

    2009-03-23

    The IAEA Nuclear Data Section convened the 18th meeting of the International Network of Nuclear Structure and Decay Data Evaluators at the IAEA Headquarters, Vienna, 23 to 27 March 2009. This meeting was attended by 22 scientists from 14 Member States, plus IAEA staff, concerned with the compilation, evaluation and dissemination of nuclear structure and decay data. A summary of the meeting, recommendations/conclusions, data centre reports, and various proposals considered, modified and agreed by the participants are contained within this document. The International Network of Nuclear Structure and Decay Data (NSDD) Evaluators holds biennial meetings under the auspices of the IAEA, and consists of evaluation groups and data service centres in several countries. This network has the objective of providing up-to-date nuclear structure and decay data for all known nuclides by evaluating all existing experimental data. Data resulting from this international evaluation collaboration is included in the Evaluated Nuclear Structure Data File (ENSDF) and published in the journals Nuclear Physics A and Nuclear Data Sheets (NDS).

  19. Underground nuclear energy complexes - technical and economic advantages

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Carl W [Los Alamos National Laboratory; Kunze, Jay F [IDAHO STATE UNIV; Giraud, Kellen M [BABECOCK AND WILCOX; Mahar, James M [IDAHO STATE UNIV

    2010-01-01

    Underground nuclear power plant parks have been projected to be economically feasible compared to above ground instalIations. This paper includes a thorough cost analysis of the savings, compared to above ground facilities, resulting from in-place entombment (decommissioning) of facilities at the end of their life. reduced costs of security for the lifetime of the various facilities in the underground park. reduced transportation costs. and reduced costs in the operation of the waste storage complex (also underground). compared to the fair share of the costs of operating a national waste repository.

  20. Importin beta negatively regulates nuclear membrane fusion and nuclear pore complex assembly.

    Science.gov (United States)

    Harel, Amnon; Chan, Rene C; Lachish-Zalait, Aurelie; Zimmerman, Ella; Elbaum, Michael; Forbes, Douglass J

    2003-11-01

    Assembly of a eukaryotic nucleus involves three distinct events: membrane recruitment, fusion to form a double nuclear membrane, and nuclear pore complex (NPC) assembly. We report that importin beta negatively regulates two of these events, membrane fusion and NPC assembly. When excess importin beta is added to a full Xenopus nuclear reconstitution reaction, vesicles are recruited to chromatin but their fusion is blocked. The importin beta down-regulation of membrane fusion is Ran-GTP reversible. Indeed, excess RanGTP (RanQ69L) alone stimulates excessive membrane fusion, leading to intranuclear membrane tubules and cytoplasmic annulate lamellae-like structures. We propose that a precise balance of importin beta to Ran is required to create a correct double nuclear membrane and simultaneously to repress undesirable fusion events. Interestingly, truncated importin beta 45-462 allows membrane fusion but produces nuclei lacking any NPCs. This reveals distinct importin beta-regulation of NPC assembly. Excess full-length importin beta and beta 45-462 act similarly when added to prefused nuclear intermediates, i.e., both block NPC assembly. The importin beta NPC block, which maps downstream of GTPgammaS and BAPTA-sensitive steps in NPC assembly, is reversible by cytosol. Remarkably, it is not reversible by 25 microM RanGTP, a concentration that easily reverses fusion inhibition. This report, using a full reconstitution system and natural chromatin substrates, significantly expands the repertoire of importin beta. Its roles now encompass negative regulation of two of the major events of nuclear assembly: membrane fusion and NPC assembly.

  1. T dependence of nuclear spin-echo decay at low temperatures in YbRh2Si2

    Science.gov (United States)

    Kambe, S.; Sakai, H.; Tokunaga, Y.; Hattori, T.; Lapertot, G.; Matsuda, T. D.; Knebel, G.; Flouquet, J.; Walstedt, R. E.

    2017-05-01

    The authors report 29Si nuclear spin-echo oscillations and decay measurements on a single crystal of YbRh2Si2 . These quantities are found to be T independent from 300 K down to ˜20 K, showing, however, a strong T dependence below 20 K. These results indicate that electronic states near the Fermi level are modified at low temperatures. The observed spin-echo oscillations can be interpreted with the Ruderman-Kittel and pseudodipolar interactions between nearest-neighbor Si nuclei driven by conduction electron scattering at the Fermi surface. Possible modifications to the Fermi surface at low temperatures are discussed.

  2. Neutralino Decays in the Complex MSSM at One-Loop: a Comparison of On-Shell Renormalization Schemes

    CERN Document Server

    Bharucha, A; von der Pahlen, F; Schappacher, C

    2012-01-01

    We evaluate two-body decay modes of neutralinos in the Minimal Supersymmetric Standard Model with complex parameters (cMSSM). Assuming heavy scalar quarks we take into account all two-body decay channels involving charginos, neutralinos, (scalar) leptons, Higgs bosons and Standard Model gauge bosons. The evaluation of the decay widths is based on a full one-loop calculation including hard and soft QED radiation. Of particular phenomenological interest are decays involving the Lightest Supersymmetric Particle (LSP), i.e. the lightest neutralino, or a neutral or charged Higgs boson. For the chargino/neutralino sector we employ two different renormalization schemes, which differ in the treatment of the complex phases. In the numerical analysis we concentrate on the decay of the heaviest neutralino and show the results in the two different schemes. The higher-order corrections of the heaviest neutralino decay widths involving the LSP can easily reach a level of about 10-15%, while the corrections to the decays to...

  3. DINÁMICA DEL COMPLEJO DEL PORO NUCLEAR DINAMICS OF NUCLEAR PORE COMPLEX

    Directory of Open Access Journals (Sweden)

    TD GEYDAN

    Full Text Available El complejo del poro nuclear (CPN es un conjunto supra-molecular compuesto de múltiples copias de 30 familias de proteínas diferentes, siendo 456 nucleoporinas (Nups en total que atraviesan la envoltura nuclear de todos los organismos pertenecientes al dominio Eukaria. El CPN es la compuerta del núcleo por lo tanto, todas las macromoléculas deben atravesarla para transitar del núcleo al citoplasma y viceversa. Durante los últimos años, se han propuesto varios modelos para explicar la regulación y el transporte de macromoléculas a través del CPN. En este escrito se describe la estructura, los mecanismos y procesos involucrados durante el transporte a través del CPN, y cómo estos procesos son regulados por interacciones macromoleculares altamente dinámicas.The nuclear pore complex (NPC is a large supramolecular assemble made up of multiple copies of about 30 different families proteins, so in total 456 nucleoporines (Nups span the nuclear envelope of all Eukariotic organisms. The NPC is considered the gate through which all macromolecules must pass in order to achieve nucleo-cytoplasmic transport. The aim of this review is to describe the structure, mechanisms and processes involved during the transportation of molecules and how of these processes are regulated by highly dynamic macromolecular interactions with molecules of the NPC which have been described during the past years.

  4. Decay of the excited compound system *56Ni formed through various channels using deformed Coulomb and deformed nuclear proximity potentials

    Science.gov (United States)

    Santhosh, K. P.; Subha, P. V.

    2017-06-01

    The total cross section, the intermediate mass fragment (IMF) production cross section, and the cross section for the formation of light particles (LPs) for the decay of compound system *56Ni formed through the entrance channel 32S+24Mg have been evaluated by taking the scattering potential as the sum of deformed Coulomb and deformed nuclear proximity potentials, for various Ec .m . values. The computed results have been compared with the available experimental data of total cross section corresponding to Ec .m .=60.5 and 51.6 MeV for the entrance channel 32S+24Mg , which were found to be in good agreement. The experimental values for the LP production cross section and IMF cross section for the channel 32S+24Mg were also found to agree with our calculations. Hence we have extended our studies and have thus computed the total cross section, IMF cross section, and LP cross section for the decay of *56Ni formed through the other three entrance channels 36Ar+20Ne,40Ca+16O , and 28Si+28Si with different Ec .m . values. Hence, we hope that our predictions on the evaluations of the IMF cross sections and the LP cross sections for the decay of *56Ni formed through these three channels can be used for further experimental studies.

  5. Investigation of rare nuclear decays with BaF$_2$ crystal scintillator contaminated by radium

    CERN Document Server

    Belli, P; Cappella, F; Caracciolo, V; Cerulli, R; Danevich, F A; Di Marco, A; Incicchitti, A; Poda, D V; Polischuk, O G; Tretyak, V I

    2014-01-01

    The radioactive contamination of a BaF$_2$ scintillation crystal with mass of 1.714 kg was measured over 101 hours in the low-background DAMA/R&D set-up deep underground (3600 m w.e.) at the Gran Sasso National Laboratories of INFN (LNGS, Italy). The half-life of $^{212}$Po (present in the crystal scintillator due to contamination by radium) was measured as $T_{1/2}(^{212}$Po) = 298.8$\\pm$0.8(stat.)$\\pm$1.4(syst.) ns by analysis of the events' pulse profiles. The $^{222}$Rn nuclide is known as 100% decaying via emission of $\\alpha$ particle with $T_{1/2}$ = 3.82 d; however, its $\\beta$ decay is also energetically allowed with $Q_\\beta = 24\\pm21$ keV. Search for decay chains of events with specific pulse shapes characteristic for $\\alpha$ or for $\\beta/\\gamma$ signals and with known energies and time differences allowed us to set, for the first time, the limit on the branching ratio of $^{222}$Rn relatively to $\\beta$ decay as $B_\\beta 8.0$ y). Half-life limits of $^{212}$Pb, $^{222}$Rn and $^{226}$Ra rel...

  6. Nuclear Structure Effects in the Exotic Decay of $^{225}$Ac via $^{14}$C Emission

    CERN Multimedia

    2002-01-01

    % IS323 \\\\ \\\\ We propose to build at Isolde a high intensity $^{225}$Ac source by $\\beta$-decay of $^{225}$(Ra+Fr) beam, to be used at the superconducting spectrometer SOLENO of IPN-Orsay in order to study a possible fine structure in the spectrum of $^{14}$C ions spontaneously emitted by $^{225}$Ac.

  7. Investigation of rare nuclear decays with BaF{sub 2} crystal scintillator contaminated by radium

    Energy Technology Data Exchange (ETDEWEB)

    Belli, P. [INFN, Sezione di Roma ' ' Tor Vergata' ' , Rome (Italy); Bernabei, R. [INFN, Sezione di Roma ' ' Tor Vergata' ' , Rome (Italy); Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Fisica, Rome (Italy); Cappella, F. [INFN, Sezione di Roma, Rome (Italy); Universita di Roma ' ' La Sapienza' ' , Dipartimento di Fisica, Rome (Italy); Caracciolo, V.; Cerulli, R. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy); Danevich, F.A.; Poda, D.V. [Institute for Nuclear Research, Kyiv (Ukraine); Di Marco, A. [Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Fisica, Rome (Italy); Incicchitti, A. [INFN, Sezione di Roma, Rome (Italy); Polischuk, O.G.; Tretyak, V.I. [INFN, Sezione di Roma, Rome (Italy); Institute for Nuclear Research, Kyiv (Ukraine)

    2014-09-15

    The radioactive contamination of a BaF{sub 2} scintillation crystal with mass of 1.714 kg was measured over 101 hours in the low-background DAMA/R and D set-up deep underground (3600 m w.e.) at the Gran Sasso National Laboratories of INFN (LNGS, Italy). The half-life of {sup 212}Po (present in the crystal scintillator due to contamination by radium) was measured as T{sub 1/2}({sup 212}Po) = 298.8 ± 0.8(stat.) ± 1.4(syst.) ns by the analysis of the events' pulse profiles. The {sup 222}Rn nuclide is known as 100% decaying via the emission of the α particle with T{sub 1/2} = 3.82d; however, its β decay is also energetically allowed with Q{sub β} = 24 ± 21 keV. Search for decay chains of events with specific pulse shapes characteristic for α or for β/γ signals and with known energies and time differences allowed us to set, for the first time, the limit on the branching ratio of {sup 222}Rn relatively to β decay as B{sub β} < 0.13 % at 90% C.L. (equivalent to limit on partial half-life T{sub 1/2}{sup β} > 8.0y). The half-life limits of {sup 212}Pb, {sup 222}Rn and {sup 226}Ra relatively to 2 β decays are also improved in comparison with the earlier results. (orig.)

  8. New determination of double-beta-decay properties in 48Ca: high-precision Q-value measurement and improved nuclear matrix element calculations

    CERN Document Server

    Kwiatkowski, A A; Holt, J D; Chaudhuri, A; Chowdhury, U; Eibach, M; Engel, J; Gallant, A T; Grossheim, A; Horoi, M; Lennarz, A; Macdonald, T D; Pearson, M R; Schultz, B E; Simon, M C; Senkov, R A; Simon, V V; Zuber, K; Dilling, J

    2013-01-01

    We report a direct measurement of the Q-value of the neutrinoless double-beta-decay candidate 48Ca at the TITAN Penning-trap mass spectrometer, with the result that Q = 4267.98(32) keV. We measured the masses of both the mother and daughter nuclides, and in the latter case found a 1 keV deviation from the literature value. In addition to the Q-value, we also present results of a new calculation of the neutrinoless double-beta-decay nuclear matrix element of 48Ca. Using diagrammatic many-body perturbation theory to second order to account for physics outside the valence space, we constructed an effective shell-model double-beta-decay operator, which increased the nuclear matrix element by about 75% compared with that produced by the bare operator. The new Q-value and matrix element strengthen the case for a 48Ca double-beta-decay experiment.

  9. Karyopherins regulate nuclear pore complex barrier and transport function.

    Science.gov (United States)

    Kapinos, Larisa E; Huang, Binlu; Rencurel, Chantal; Lim, Roderick Y H

    2017-09-01

    Nucleocytoplasmic transport is sustained by karyopherins (Kaps) and a Ran guanosine triphosphate (RanGTP) gradient that imports nuclear localization signal (NLS)-specific cargoes (NLS-cargoes) into the nucleus. However, how nuclear pore complex (NPC) barrier selectivity, Kap traffic, and NLS-cargo release are systematically linked and simultaneously regulated remains incoherent. In this study, we show that Kapα facilitates Kapβ1 turnover and occupancy at the NPC in a RanGTP-dependent manner that is directly coupled to NLS-cargo release and NPC barrier function. This is underpinned by the binding affinity of Kapβ1 to phenylalanine-glycine nucleoporins (FG Nups), which is comparable with RanGTP·Kapβ1, but stronger for Kapα·Kapβ1. On this basis, RanGTP is ineffective at releasing standalone Kapβ1 from NPCs. Depleting Kapα·Kapβ1 by RanGTP further abrogates NPC barrier function, whereas adding back Kapβ1 rescues it while Kapβ1 turnover softens it. Therefore, the FG Nups are necessary but insufficient for NPC barrier function. We conclude that Kaps constitute integral constituents of the NPC whose barrier, transport, and cargo release functionalities establish a continuum under a mechanism of Kap-centric control. © 2017 Kapinos et al.

  10. Energetics of Transport through the Nuclear Pore Complex.

    Directory of Open Access Journals (Sweden)

    Ali Ghavami

    Full Text Available Molecular transport across the nuclear envelope in eukaryotic cells is solely controlled by the nuclear pore complex (NPC. The NPC provides two types of nucleocytoplasmic transport: passive diffusion of small molecules and active chaperon-mediated translocation of large molecules. It has been shown that the interaction between intrinsically disordered proteins that line the central channel of the NPC and the transporting cargoes is the determining factor, but the exact mechanism of transport is yet unknown. Here, we use coarse-grained molecular dynamics simulations to quantify the energy barrier that has to be overcome for molecules to pass through the NPC. We focus on two aspects of transport. First, the passive transport of model cargo molecules with different sizes is studied and the size selectivity feature of the NPC is investigated. Our results show that the transport probability of cargoes is significantly reduced when they are larger than ∼5 nm in diameter. Secondly, we show that incorporating hydrophobic binding spots on the surface of the cargo effectively decreases the energy barrier of the pore. Finally, a simple transport model is proposed which characterizes the energy barrier of the NPC as a function of diameter and hydrophobicity of the transporting particles.

  11. Diffusion of Macromolecules across the Nuclear Pore Complex

    CERN Document Server

    Chakrabarti, Rajarshi; Sebastian, K L

    2007-01-01

    Nuclear pore complexes (NPCs) are very selective filters that monitor the transport between the cytoplasm and the nucleoplasm. Two models have been suggested for the plug of the NPC. They are (i) it is a reversible hydrogel or (ii) it is a polymer brush. We propose a mesoscopic model for the transport of a protein through the plug, that is general enough to cover both. The protein stretches the plug and creates a local deformation. The bubble so created (prtoein+deformation) executes random walk in the plug. We find that for faster relaxation of the gel, the diffusion of the bubble is greater. Further, on using parameters appropriate for the brush, we find that the diffusion coefficient is much lower. Hence the gel model seems to be more likely explanation for the workings of the plug.

  12. Laser assisted {alpha} decay

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda Cortes, Hector Mauricio

    2012-02-01

    Excited or short-lived nuclei often decay by emitting alpha particles that are assumed to be preformed inside the nucleus and confined in the nuclear potential well. In this picture, {alpha} decay refers to the tunneling of the alpha particle through the potential barrier. In this thesis we investigate for the first time how strong laser fields can assist the tunneling of the alpha particle and thus influence the nuclear decay. Generally speaking, laser-assisted {alpha} decay can be described as laser-assisted tunneling of a quasistationary state, i.e, a slowly decaying state. Our theoretical treatment is developed starting from the complex trajectory formulation of the well-known strong-field approximation used to describe laser-induced ionization. We extend this formulation and develop a method to treat the decay of quasistationary states. The effect of both static and optical and X-ray monochromatic fields on the lifetimes and {alpha}-particle emission spectra are investigated for a number of {alpha}-emitting nuclei. We find that even at strong intensities, the laser-induced acceleration of the {alpha} decay is negligible, ranging from a relative modification in the decay rate of 10{sup -3} for static fields of electric field strengths of 10{sup 15} V/m, to 10{sup -8} for strong optical fields with intensities of 10{sup 22} W/cm{sup 2}, and to 10{sup -6} for strong X-ray fields with laser intensities around 10{sup 24} W/cm{sup 2}. However, the effect of the external field is visible in the spectrum of emitted alpha particles, leading in the case of optical fields even to rescattering phenomena for intensities approaching 6 x 10{sup 22} W/cm{sup 2}. The dynamics of the alpha particle in laser fields of intensities below the rescattering limit is investigated.

  13. Effect of a triaxial nuclear shape on proton tunneling: the decay and structure of 145Tm.

    Science.gov (United States)

    Seweryniak, D; Blank, B; Carpenter, M P; Davids, C N; Davinson, T; Freeman, S J; Hammond, N; Hoteling, N; Janssens, R V F; Khoo, T L; Liu, Z; Mukherjee, G; Robinson, A; Scholey, C; Sinha, S; Shergur, J; Starosta, K; Walters, W B; Woehr, A; Woods, P J

    2007-08-24

    Gamma rays deexciting states in the proton emitter 145Tm were observed using the recoil-decay tagging method. The 145Tm ground-state rotational band was found to exhibit the properties expected for an h{11/2} proton decoupled band. In addition, coincidences between protons feeding the 2{+} state in 144Er and the 2{+}-->0{+} gamma-ray transition were detected, the first measurement of this kind, leading to a more precise value for the 2{+} excitation energy of 329(1) keV. Calculations with the particle-rotor model and the core quasiparticle coupling model indicate that the properties of the pi{11/2} band and the proton-decay rates in 145Tm are consistent with the presence of triaxiality with an asymmetry parameter gamma approximately 20 degrees .

  14. Search for non Standard Model physics in nuclear-$\\beta$ decay with the WITCH experiment

    CERN Document Server

    Coeck, Sam

    In this work the WITCH experiment, which primarily aims for precision measurements of the beta-neutrino-angular correlation coefficient, is presented in detail. First a theoretical description of the beta-decay process is presented and it was shown how measurements of correlation coefficients can reveal the exact nature of the weak interaction. Although many experiments have already been conducted in this field, there is still considerable room for additional phenomena that are not included in the Standard Model. At WITCH the beta-neutrino-angular correlation coefficient will be obtained from precision measurements of the energy spectrum of the nuclei that recoil after beta-decay, thus avoiding the need to observe the neutrino. To enable a measurement of the recoiling ions, the setup uses a combination of two electromagnetic Penning traps and a retardation spectrometer. This allows one to construct the scattering free radioactive source that is needed as the recoiling ions have only a very small kinetic energ...

  15. Report on the workshop "Decay spectroscopy at CARIBU: advanced fuel cycle applications, nuclear structure and astrophysics". 14-16 April 2011, Argonne National Laboratory, USA.

    Energy Technology Data Exchange (ETDEWEB)

    Kondev, F.; Carpenter, M.P.; Chowdhury, P.; Clark, J.A.; Lister, C.J.; Nichols, A.L.; Swewryniak, D. (Nuclear Engineering Division); (Univ. of Massachusetts); (Univ. of Surrey)

    2011-10-06

    A workshop on 'Decay Spectroscopy at CARIBU: Advanced Fuel Cycle Applications, Nuclear Structure and Astrophysics' will be held at Argonne National Laboratory on April 14-16, 2011. The aim of the workshop is to discuss opportunities for decay studies at the Californium Rare Isotope Breeder Upgrade (CARIBU) of the ATLAS facility with emphasis on advanced fuel cycle (AFC) applications, nuclear structure and astrophysics research. The workshop will consist of review and contributed talks. Presentations by members of the local groups, outlining the status of relevant in-house projects and availabile equipment, will also be organized. time will also be set aside to discuss and develop working collaborations for future decay studies at CARIBU. Topics of interest include: (1) Decay data of relevance to AFC applications with emphasis on reactor decay heat; (2) Discrete high-resolution gamma-ray spectroscopy following radioactive decya and related topics; (3) Calorimetric studies of neutron-rich fission framgents using Total ABsorption Gamma-Ray Spectrometry (TAGS) technique; (4) Beta-delayed neutron emissions and related topics; and (5) Decay data needs for nuclear astrophysics.

  16. Nuclear two-photon decay in 0/sup +/ -> 0/sup +/ transitions

    Energy Technology Data Exchange (ETDEWEB)

    Kramp, J.; Habs, D.; Kroth, R.; Music, M.; Schirmer, J.; Schwalm, D.; Broude, C.

    1987-11-23

    The two-photon decay of the first excited 0/sup +/ state of /sup 16/O has been measured using the Heidelberg-Darmstadt crystal ball. A branching ratio of GAMMA/sub ..gamma gamma..//GAMMA/sub tot/ = (6.6+-0.5).10/sup -4/ was obtained. As in the cases of /sup 40/Ca and /sup 90/Zr previously reported by us, the 2..gamma.. decay of /sup 16/O proceeds via double E1 and M1 transitions of similar strength; the evidence is the observed interference term in the 2..gamma.. angular correlation. The ratio of the matrix elements ..cap alpha../sub E1//chi for /sup 16/O was restricted to the two inverse values (-6.2+-1.5) or (-0.16+-0.04). An interpretation of 2..gamma.. matrix elements observed for /sup 16/O, /sup 40/Ca and /sup 90/Zr in terms of the electric polarizabilities and magnetic susceptibility is given leading to a qualitative understanding of this decay mode.

  17. ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data

    Energy Technology Data Exchange (ETDEWEB)

    G. Palmiotti

    2011-12-01

    The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment. The principal advances in the new library are: (1) An increase in the breadth of neutron reaction cross section coverage, extending from 393 nuclides to 418 nuclides; (2) Covariance uncertainty data for 185 of the most important nuclides, as documented in companion papers in this edition; (3) R-matrix analyses of neutron reactions on light nuclei, including isotopes of He, Li, and Be; (4) Resonance parameter analyses at lower energies and statistical high energy reactions at higher energies for isotopes of F, Cl, K, Ti, V, Mn, Cr, Ni, Zr and W; (5) Modifications to thermal neutron reactions on fission products (isotopes of Mo, Tc, Rh, Ag, Cs, Nd, Sm, Eu) and neutron absorber materials (Cd, Gd); (6) Improved minor actinide evaluations for isotopes of U, Np, Pu, and Am (we are not making changes to the major actinides 235,238U and 239Pu at this point, except for delayed neutron data, and instead we intend to update them after a further period of research in experiment and theory), and our adoption of JENDL-4.0 evaluations for isotopes of Cm, Bk, Cf, Es, Fm, and some other minor actinides; (7) Fission energy release evaluations; (8) Fission product yield advances for fission-spectrum neutrons and 14 MeV neutrons incident on 239Pu; and (9) A new Decay Data sublibrary. Integral validation testing of the ENDF/B-VII.1 library is provided for a variety of quantities: For nuclear criticality, the VII.1 library maintains the generally-good performance seen for VII.0 for a wide

  18. Specificity of recognition of mRNA 5' cap by human nuclear cap-binding complex.

    Science.gov (United States)

    Worch, Remigiusz; Niedzwiecka, Anna; Stepinski, Janusz; Mazza, Catherine; Jankowska-Anyszka, Marzena; Darzynkiewicz, Edward; Cusack, Stephen; Stolarski, Ryszard

    2005-09-01

    The heterodimeric nuclear cap-binding complex (CBC) binds to the mono-methylated 5' cap of eukaryotic RNA polymerase II transcripts such as mRNA and U snRNA. The binding is important for nuclear maturation of mRNAs and possibly in the first round of translation and nonsense-mediated decay. It is also essential for nuclear export of U snRNAs in metazoans. We report characterization by fluorescence spectroscopy of the recognition of 5' capped RNA by human CBC. The association constants (K(as)) for 17 mono- and dinucleotide cap analogs as well as for the oligomer m7GpppA(m2') pU(m2')pA(m2') cover the range from 1.8 x 10(6) M(-1) to 2.3 x 10(8) M(-1). Higher affinity for CBC is observed for the dinucleotide compared with mononucleotide analogs, especially for those containing a purine nucleoside next to m7G. The mRNA tetramer associates with CBC as tightly as the dinucleotide analogs. Replacement of Tyr138 by alanine in the CBP20 subunit of CBC reduces the cap affinity except for the mononucleotide analogs, consistent with the crystallographic observation of the second base stacking on this residue. Our spectroscopic studies showed that contrary to the other known cap-binding proteins, the first two nucleotides of a capped-RNA are indispensable for its specific recognition by CBC. Differences in the cap binding of CBC compared with the eukaryotic translation initiation factor 4E (eIF4E) are analyzed and discussed regarding replacement of CBC by eIF4E.

  19. Higher order corrections to Higgs boson decays in the MSSM with complex parameters

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Karina E. [Bonn Univ. (Germany). Bethe Center for Theoretical Physics; Rzehak, Heidi [Freiburg Univ. (Germany). Physikalisches Inst.; Weiglein, Georg [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-03-15

    We discuss Higgs boson decays in the CP-violating MSSM, and examine their phe- nomenological impact using cross section limits from the LEP Higgs searches. This includes a discussion of the full 1-loop results for the partial decay widths of neutral Higgs bosons into lighter neutral Higgs bosons (h{sub a}{yields}h{sub b}h{sub c}) and of neutral Higgs bosons into fermions (h{sub a}{yields}f anti f). In calculating the genuine vertex corrections, we take into account the full spectrum of supersymmetric particles and all complex phases of the supersymmetric parameters. These genuine vertex corrections are supplemented with Higgs propagator corrections incorporating the full one-loop and the dominant two-loop contributions, and we illustrate a method of consistently treating diagrams involving mixing with Goldstone and Z bosons. In particular, the genuine vertex corrections to the process h{sub a}{yields}h{sub b}h{sub c} are found to be very large and, where this process is kinematically allowed, can have a significant effect on the regions of the CPX bench- mark scenario which can be excluded by the results of the Higgs searches at LEP. However, there remains an unexcluded region of CPX parameter space at a lightest neutral Higgs boson mass of {proportional_to}45 GeV. In the analysis, we pay particular attention to the conversion between parameters defined in different renormalisation schemes and are therefore able to make a comparison to the results found using renormalisation group improved/effective potential calculations. (orig.)

  20. ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M.B.; Herman, M.; Author(s): Chadwick,M.B.; Herman,M.; Oblozinsky,P.; Dunn,M.E.; Danon,Y.; Kahler,A.C.; Smith,D.L.; Pritychenko,B.; Arbanas,G.; Arcilla,R.; Brewer,R.; Brown,D.A.; Capote,R.; Carlson,A.D.; Cho,Y.S.; Derrien,H.; Guber,K.; Hale,G.M.; Hoblit,S.; Holloway,S.: Johnson,T.D.; Kawano,T.; Kiedrowski,B.C.; Kim,H.; Kunieda,S.; Larson,N.M.; Leal,L.; Lestone,J.P.; Little,R.C.; McCutchan,E.A.; MacFarlane,R.E.; MacInnes,M.; Mattoon,C.M.; McKnight,R.D.; Mughabghab,S.F.; Nobre,G.P.A.; Palmiotti,G.; Palumbo,A.; Pigni,M.T.; Pronyaev,V.G.; Sayer,R.O.; Sonzogni,A.A.; Summers,N.C.; Talou,P.; Thompson,I.J.; Trkov,A.; Vogt,R.L.; van der Marck,S.C.; Wallner,A.; White,M.C.; Wiarda,D.; Young,P.G.

    2011-12-01

    The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment. The principal advances in the new library are: (1) An increase in the breadth of neutron reaction cross section coverage, extending from 393 nuclides to 423 nuclides; (2) Covariance uncertainty data for 190 of the most important nuclides, as documented in companion papers in this edition; (3) R-matrix analyses of neutron reactions on light nuclei, including isotopes of He, Li, and Be; (4) Resonance parameter analyses at lower energies and statistical high energy reactions for isotopes of Cl, K, Ti, V, Mn, Cr, Ni, Zr and W; (5) Modifications to thermal neutron reactions on fission products (isotopes of Mo, Tc, Rh, Ag, Cs, Nd, Sm, Eu) and neutron absorber materials (Cd, Gd); (6) Improved minor actinide evaluations for isotopes of U, Np, Pu, and Am (we are not making changes to the major actinides {sup 235,238}U and {sup 239}Pu at this point, except for delayed neutron data and covariances, and instead we intend to update them after a further period of research in experiment and theory), and our adoption of JENDL-4.0 evaluations for isotopes of Cm, Bk, Cf, Es, Fm, and some other minor actinides; (7) Fission energy release evaluations; (8) Fission product yield advances for fission-spectrum neutrons and 14 MeV neutrons incident on {sup 239}Pu; and (9) A new decay data sublibrary. Integral validation testing of the ENDF/B-VII.1 library is provided for a variety of quantities: For nuclear criticality, the VII.1 library maintains the generally-good performance seen for VII.0

  1. ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data

    Science.gov (United States)

    Chadwick, M. B.; Herman, M.; Obložinský, P.; Dunn, M. E.; Danon, Y.; Kahler, A. C.; Smith, D. L.; Pritychenko, B.; Arbanas, G.; Arcilla, R.; Brewer, R.; Brown, D. A.; Capote, R.; Carlson, A. D.; Cho, Y. S.; Derrien, H.; Guber, K.; Hale, G. M.; Hoblit, S.; Holloway, S.; Johnson, T. D.; Kawano, T.; Kiedrowski, B. C.; Kim, H.; Kunieda, S.; Larson, N. M.; Leal, L.; Lestone, J. P.; Little, R. C.; McCutchan, E. A.; MacFarlane, R. E.; MacInnes, M.; Mattoon, C. M.; McKnight, R. D.; Mughabghab, S. F.; Nobre, G. P. A.; Palmiotti, G.; Palumbo, A.; Pigni, M. T.; Pronyaev, V. G.; Sayer, R. O.; Sonzogni, A. A.; Summers, N. C.; Talou, P.; Thompson, I. J.; Trkov, A.; Vogt, R. L.; van der Marck, S. C.; Wallner, A.; White, M. C.; Wiarda, D.; Young, P. G.

    2011-12-01

    The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment. The principal advances in the new library are: (1) An increase in the breadth of neutron reaction cross section coverage, extending from 393 nuclides to 423 nuclides; (2) Covariance uncertainty data for 190 of the most important nuclides, as documented in companion papers in this edition; (3) R-matrix analyses of neutron reactions on light nuclei, including isotopes of He, Li, and Be; (4) Resonance parameter analyses at lower energies and statistical high energy reactions for isotopes of Cl, K, Ti, V, Mn, Cr, Ni, Zr and W; (5) Modifications to thermal neutron reactions on fission products (isotopes of Mo, Tc, Rh, Ag, Cs, Nd, Sm, Eu) and neutron absorber materials (Cd, Gd); (6) Improved minor actinide evaluations for isotopes of U, Np, Pu, and Am (we are not making changes to the major actinides 235,238U and 239Pu at this point, except for delayed neutron data and covariances, and instead we intend to update them after a further period of research in experiment and theory), and our adoption of JENDL-4.0 evaluations for isotopes of Cm, Bk, Cf, Es, Fm, and some other minor actinides; (7) Fission energy release evaluations; (8) Fission product yield advances for fission-spectrum neutrons and 14 MeV neutrons incident on 239Pu; and (9) A new decay data sublibrary. Integral validation testing of the ENDF/B-VII.1 library is provided for a variety of quantities: For nuclear criticality, the VII.1 library maintains the generally-good performance seen for VII.0 for a wide range

  2. Correlative super-resolution fluorescence and electron microscopy of the nuclear pore complex with molecular resolution.

    Science.gov (United States)

    Löschberger, Anna; Franke, Christian; Krohne, Georg; van de Linde, Sebastian; Sauer, Markus

    2014-10-15

    Here, we combine super-resolution fluorescence localization microscopy with scanning electron microscopy to map the position of proteins of nuclear pore complexes in isolated Xenopus laevis oocyte nuclear envelopes with molecular resolution in both imaging modes. We use the periodic molecular structure of the nuclear pore complex to superimpose direct stochastic optical reconstruction microscopy images with a precision of <20 nm on electron micrographs. The correlative images demonstrate quantitative molecular labeling and localization of nuclear pore complex proteins by standard immunocytochemistry with primary and secondary antibodies and reveal that the nuclear pore complex is composed of eight gp210 (also known as NUP210) protein homodimers. In addition, we find subpopulations of nuclear pore complexes with ninefold symmetry, which are found occasionally among the more typical eightfold symmetrical structures.

  3. The nuclear matrix elements of 0vββ decay and the NUMEN project at INFN-LNS

    Science.gov (United States)

    Cappuzzello, F.; Agodi, C.; Aciksoz, E.; Acosta, L.; Aslanouglou, X.; Auerbach, N.; Bijker, R.; Bonanno, D.; Bongiovanni, D.; Borello, T.; Boudhaim, S.; Bouhssa, M. L.; Boztosun, I.; Calabretta, L.; Calanna, A.; Carbone, D.; Cavallaro, M.; Calvo, D.; Chávez Lomelí, E. R.; Colonna, M.; D'Agostino, G.; Deshmukh, N.; de Faria, P. N.; Ferrero, A.; Foti, A.; Finocchiaro, P.; Gomes, P. R. S.; Greco, V.; Hacisalihoglu, A.; Housni, Z.; Khouaja, A.; Inchaou, J.; Lanzalone, G.; La Via, F.; Lay, J. A.; Lenske, H.; Linares, R.; Lubian, J.; Iazzi, F.; Introzzi, R.; Lavagno, A.; Lo Presti, D.; Medina, N.; Mendes, D. R.; Muoio, A.; Oliveira, J. R. B.; Pakou, A.; Pandola, L.; Rifuggiato, D.; Rodrigues, M. R. D.; Santagati, G.; Santopinto, E.; Scaltrito, L.; Sgouros, O.; Solakcı, S. O.; Soukeras, V.; Tudisco, S.; Vsevolodovna, R. I. M.; Zagatto, V.

    2016-07-01

    An innovative technique to access the nuclear matrix elements entering the expression of the life time of the double beta decay by relevant cross section measurements of double charge exchange reactions is proposed. A key aspect of the project is the use of the MAGNEX large acceptance magnetic spectrometer, for the detection of the ejectiles, and of the LNS K800 Superconducting Cyclotron (CS), for the acceleration of the required high resolution and low emittance heavy-ion beams, already in operation at INFN Laboratory Nazionali del Sud in Catania (Italy). However, a major upgrade is foreseen for the INFN-LNS research infrastructure to cope with beam currents as high as several ppA required by the project.

  4. Nuclear structure of {sup 37,} {sup 38}Si investigated by decay spectroscopy of {sup 37,} {sup 38}Al

    Energy Technology Data Exchange (ETDEWEB)

    Steiger, K.; Gernhaeuser, R.; Faestermann, T.; Hinke, C. [Technische Universitaet Muenchen, Physik Department E12, Garching (Germany); Nishimura, S.; Chen, R.; Kurata-Nishimura, M.; Lorusso, G. [RIKEN Nishina Center, Saitama (Japan); Li, Z. [RIKEN Nishina Center, Saitama (Japan); Peking University, Department of Physics, Beijing (China); Utsuno, Y. [Japan Atomic Energy Agency, Advanced Science Research Center, Tokai, Ibaraki (Japan); University of Tokyo, Center for Nuclear Study, Tokyo (Japan); Kruecken, R. [Technische Universitaet Muenchen, Physik Department E12, Garching (Germany); TRIUMF, Vancouver, British Columbia (Canada); University of British Columbia, Department of Physics and Astronomy, Vancouver, BC (Canada); Miyashita, Y.; Sugimoto, K.; Yoshinaga, K. [Tokyo University of Science, Department of Physics, Chiba (Japan); Shimizu, N. [University of Tokyo, Center for Nuclear Study, Tokyo (Japan); Sumikama, T. [Tohoku University, Department of Physics, Miyagi (Japan); Watanabe, H. [RIKEN Nishina Center, Saitama (Japan); Beihang University, International Research Center for Nuclei and Particles in the Cosmos, Beijing (China); Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China)

    2015-09-15

    We present a study on the β decays of the neutron-rich isotopes {sup 37}Al and {sup 38}Al, produced by projectile fragmentation of a {sup 48}Ca beam with an energy E = 345 A MeV at the RIKEN Nishina Center. The half-lives of {sup 37}Al and {sup 38}Al have been measured to 11.5(4)ms and 9.0(7)ms, respectively, using the CAITEN implantation and decay detector setup. The level schemes for {sup 37}Si and {sup 38}Si were deduced by employing γ-γ coincidence spectroscopy following the event-by-event identification of the implanted nuclei. Comparison to large scale nuclear shell model calculations allowed for a tentative assignment of spin and parity of the populated states. The data indicate that the classical shell gap at magic neutron number N = 28 between the νf{sub 7/2} and νp{sub 3/2} orbits gets reduced by 0.3 MeV in this region leading to low-energy states with intruder configuration in {sup 37}Si. (orig.)

  5. Microtiterplate phosphate assay based on luminescence quenching of a terbium complex amenable to decay time detection.

    Science.gov (United States)

    Turel, Matejka; Duerkop, Axel; Yegorova, Alla; Karasyov, Alexander; Scripinets, Yulia; Lobnik, Aleksandra

    2010-08-18

    We describe a terbium-ligand complex (TbL) for a microtiterplate assay for phosphate (P) in the 0.3-100 micromol L(-1) range based on luminescence quenching. As the pH optimum is at neutral pH (7.4) the probe is quenched by both, primary (H(2)PO(4)(-)) and secondary phosphate (HPO(4)(2-)). The LOD is 110 nmol L(-1). A Stern-Volmer study revealed that quenching is mostly static. Due to the ms-decay time of TbL, the first luminescence lifetime assay for phosphate could also be developed. The lifetime-based calibration plot is linear between 0.5 and 5 micromol L(-1) of P. The effect of various surfactants on assay performance and a study on interferents are presented. The probe was successfully applied to determination of P in commercial plant fertilizers and validated against the molybdenum blue test. The probe is the most sensitive lanthanide-based probe for phosphate. Copyright 2010 Elsevier B.V. All rights reserved.

  6. Studying Biological Tissue with Fluorescence Lifetime Imaging: Microscopy, Endoscopy, and Complex Decay Profiles

    Science.gov (United States)

    Siegel, Jan; Elson, Daniel S.; Webb, Stephen E. D.; Lee, K. C. Benny; Vlandas, Alexis; Gambaruto, Giovanni L.; Léveque-Fort, Sandrine; Lever, M. John; Tadrous, Paul J.; Stamp, Gordon W. H.; Wallace, Andrew L.; Sandison, Ann; Watson, Tim F.; Alvarez, Fernando; French, Paul M. W.

    2003-06-01

    We have applied fluorescence lifetime imaging (FLIM) to the autofluorescence of different kinds of biological tissue in vitro , including animal tissue sections and knee joints as well as human teeth, obtaining two-dimensional maps with functional contrast. We find that fluorescence decay profiles of biological tissue are well described by the stretched exponential function (StrEF), which can represent the complex nature of tissue. The StrEF yields a continuous distribution of fluorescence lifetimes, which can be extracted with an inverse Laplace transformation, and additional information is provided by the width of the distribution. Our experimental results from FLIM microscopy in combination with the StrEF analysis indicate that this technique is ready for clinical deployment, including portability that is through the use of a compact picosecond diode laser as the excitation source. The results obtained with our FLIM endoscope successfully demonstrated the viability of this modality, though they need further optimization. We expect a custom-designed endoscope with optimized illumination and detection efficiencies to provide significantly improved performance.

  7. An event generator for simulations of complex β-decay experiments

    Science.gov (United States)

    Jordan, D.; Algora, A.; Tain, J. L.

    2016-08-01

    This article describes a Monte Carlo event generator for the design, optimization and performance characterization of beta decay spectroscopy experimental set-ups. The event generator has been developed within the Geant4 simulation architecture and provides new features and greater flexibility in comparison with the current available decay generator.

  8. Additional experimental evidence for a solar influence on nuclear decay rates

    CERN Document Server

    Jenkins, Jere H; Blue, Thomas E; Fischbach, Ephraim; Javorsek, Daniel; Kauffman, Andrew C; Mundy, Daniel W; Sturrock, Peter A; Talnagi, Joseph W

    2012-01-01

    Additional experimental evidence is presented in support of the recent hypothesis that a possible solar influence could explain fluctuations observed in the measured decay rates of some isotopes. These data were obtained during routine weekly calibrations of an instrument used for radiological safety at The Ohio State University Research Reactor using Cl-36. The detector system used was based on a Geiger-Mueller gas detector, which is a robust detector system with very low susceptibility to environmental changes. A clear annual variation is evident in the data, with a maximum relative count rate observed in January/February, and a minimum relative count rate observed in July/August, for seven successive years from July 2005 to June 2011. This annual variation is not likely to have arisen from changes in the detector surroundings, as we show here.

  9. Constraining nuclear photon strength functions by the decay properties of photo-excited states

    Energy Technology Data Exchange (ETDEWEB)

    Isaak, J., E-mail: j.isaak@gsi.de [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies FIAS, 60438 Frankfurt (Germany); Savran, D. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies FIAS, 60438 Frankfurt (Germany); Krtička, M. [Faculty of Mathematics and Physics, Charles University, Prague 8 (Czech Republic); Ahmed, M.W. [Department of Mathematics and Physics, North Carolina Central University, Durham, NC 27707 (United States); Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Beller, J. [Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt (Germany); Fiori, E. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies FIAS, 60438 Frankfurt (Germany); Glorius, J. [Institut für Angewandte Physik, Goethe-Universität Frankfurt, 60438 Frankfurt (Germany); Kelley, J.H. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Löher, B. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies FIAS, 60438 Frankfurt (Germany); and others

    2013-12-18

    A new approach for constraining the low-energy part of the electric dipole Photon Strength Function (E1-PSF) is presented. Experiments at the Darmstadt High-Intensity Photon Setup and the High Intensity γ{sup →}-Ray Source have been performed to investigate the decay properties of {sup 130}Te between 5.50 and 8.15 MeV excitation energy. In particular, the average γ-ray branching ratio to the ground state and the population intensity of low-lying excited states have been studied. A comparison to the statistical model shows that the latter is sensitive to the low-energy behavior of the E1-PSF, while the average ground state branching ratio cannot be described by the statistical model in the energy range between 5.5 and 6.5 MeV.

  10. Evidence for Correlations Between Nuclear Decay Rates and Earth-Sun Distance

    CERN Document Server

    Jenkins, Jere H; Buncher, John B; Gruenwald, John T; Krause, Dennis E; Mattes, Joshua J

    2008-01-01

    Unexplained periodic fluctuations in the decay rates of Si-32 and Ra-226 have been reported by groups at Brookhaven National Laboratory (Si-32), and at the Physikalisch-Technische-Bundesandstalt in Germany (Ra-226). We show from an analysis of the raw data in these experiments that the observed fluctuations are strongly correlated in time, not only with each other, but also with the distance between the Earth and the Sun. Some implications of these results are also discussed, including the suggestion that discrepancies in published half-life determinations for these and other nuclides may be attributable in part to differences in solar activity during the course of the various experiments, or to seasonal variations in fundamental constants.

  11. Measurements of observables in the pion-nucleon system, nuclear a- dependence of heavy quark production and rare decays of D and B mesons

    Energy Technology Data Exchange (ETDEWEB)

    Sadler, M.E.; Isenhower, L.D.

    1992-02-15

    This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments. (LSP)

  12. Dual RNA Processing Roles of Pat1b via Cytoplasmic Lsm1-7 and Nuclear Lsm2-8 Complexes

    Directory of Open Access Journals (Sweden)

    Caroline Vindry

    2017-08-01

    Full Text Available Pat1 RNA-binding proteins, enriched in processing bodies (P bodies, are key players in cytoplasmic 5′ to 3′ mRNA decay, activating decapping of mRNA in complex with the Lsm1-7 heptamer. Using co-immunoprecipitation and immunofluorescence approaches coupled with RNAi, we provide evidence for a nuclear complex of Pat1b with the Lsm2-8 heptamer, which binds to the spliceosomal U6 small nuclear RNA (snRNA. Furthermore, we establish the set of interactions connecting Pat1b/Lsm2-8/U6 snRNA/SART3 and additional U4/U6.U5 tri-small nuclear ribonucleoprotein particle (tri-snRNP components in Cajal bodies, the site of snRNP biogenesis. RNA sequencing following Pat1b depletion revealed the preferential upregulation of mRNAs normally found in P bodies and enriched in 3′ UTR AU-rich elements. Changes in >180 alternative splicing events were also observed, characterized by skipping of regulated exons with weak donor sites. Our data demonstrate the dual role of a decapping enhancer in pre-mRNA processing as well as in mRNA decay via distinct nuclear and cytoplasmic Lsm complexes.

  13. Biased distributions and decay of long interspersed nuclear elements in the chicken genome.

    Science.gov (United States)

    Abrusán, György; Krambeck, Hans-Jürgen; Junier, Thomas; Giordano, Joti; Warburton, Peter E

    2008-01-01

    The genomes of birds are much smaller than mammalian genomes, and transposable elements (TEs) make up only 10% of the chicken genome, compared with the 45% of the human genome. To study the mechanisms that constrain the copy numbers of TEs, and as a consequence the genome size of birds, we analyzed the distributions of LINEs (CR1's) and SINEs (MIRs) on the chicken autosomes and Z chromosome. We show that (1) CR1 repeats are longest on the Z chromosome and their length is negatively correlated with the local GC content; (2) the decay of CR1 elements is highly biased, and the 5'-ends of the insertions are lost much faster than their 3'-ends; (3) the GC distribution of CR1 repeats shows a bimodal pattern with repeats enriched in both AT-rich and GC-rich regions of the genome, but the CR1 families show large differences in their GC distribution; and (4) the few MIRs in the chicken are most abundant in regions with intermediate GC content. Our results indicate that the primary mechanism that removes repeats from the chicken genome is ectopic exchange and that the low abundance of repeats in avian genomes is likely to be the consequence of their high recombination rates.

  14. ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M. B. [Los Alamos National Laboratory (LANL); Herman, Micheal W [Brookhaven National Laboratory (BNL); Oblozinsky, Pavel [Brookhaven National Laboratory (BNL); Dunn, Michael E [ORNL; Danon, Y. [Rensselaer Polytechnic Institute (RPI); Kahler, A. [Los Alamos National Laboratory (LANL); Smith, Donald L. [Argonne National Laboratory (ANL); Pritychenko, B [Brookhaven National Laboratory (BNL); Arbanas, Goran [ORNL; Arcilla, r [Brookhaven National Laboratory (BNL); Brewer, R [Los Alamos National Laboratory (LANL); Brown, D A [Brookhaven National Laboratory (BNL); Capote, R. [International Atomic Energy Agency (IAEA); Carlson, A. D. [National Institute of Standards and Technology (NIST); Cho, Y S [Korea Atomic Energy Research Institute; Derrien, Herve [ORNL; Guber, Klaus H [ORNL; Hale, G. M. [Los Alamos National Laboratory (LANL); Hoblit, S [Brookhaven National Laboratory (BNL); Holloway, Shannon T. [Los Alamos National Laboratory (LANL); Johnson, T D [Brookhaven National Laboratory (BNL); Kawano, T. [Los Alamos National Laboratory (LANL); Kiedrowski, B C [Los Alamos National Laboratory (LANL); Kim, H [Korea Atomic Energy Research Institute; Kunieda, S [Los Alamos National Laboratory (LANL); Larson, Nancy M [ORNL; Leal, Luiz C [ORNL; Lestone, J P [Los Alamos National Laboratory (LANL); Little, R C [Los Alamos National Laboratory (LANL); Mccutchan, E A [Brookhaven National Laboratory (BNL); Macfarlane, R E [Los Alamos National Laboratory (LANL); MacInnes, M [Los Alamos National Laboratory (LANL); Matton, C M [Lawrence Livermore National Laboratory (LLNL); Mcknight, R D [Argonne National Laboratory (ANL); Mughabghab, S F [Brookhaven National Laboratory (BNL); Nobre, G P [Brookhaven National Laboratory (BNL); Palmiotti, G [Idaho National Laboratory (INL); Palumbo, A [Brookhaven National Laboratory (BNL); Pigni, Marco T [ORNL; Pronyaev, V. G. [Institute of Physics and Power Engineering (IPPE), Obninsk, Russia; Sayer, Royce O [ORNL; Sonzogni, A A [Brookhaven National Laboratory (BNL); Summers, N C [Lawrence Livermore National Laboratory (LLNL); Talou, P [Los Alamos National Laboratory (LANL); Thompson, I J [Lawrence Livermore National Laboratory (LLNL); Trkov, A. [Jozef Stefan Institute, Slovenia; Vogt, R L [Lawrence Livermore National Laboratory (LLNL); Van der Marck, S S [Nucl Res & Consultancy Grp, Petten, Netherlands; Wallner, A [University of Vienna, Austria; White, M C [Los Alamos National Laboratory (LANL); Wiarda, Dorothea [ORNL; Young, P C [Los Alamos National Laboratory (LANL)

    2011-01-01

    The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment. The principal advances in the new library are: (1) An increase in the breadth of neutron reaction cross section coverage, extending from 393 nuclides to 423 nuclides; (2) Covariance uncertainty data for 190 of the most important nuclides, as documented in companion papers in this edition; (3) R-matrix analyses of neutron reactions on light nuclei, including isotopes of He; Li, and Be; (4) Resonance parameter analyses at lower energies and statistical high energy reactions for isotopes of Cl; K; Ti, V, Mn, Cr, Ni, Zr and W; (5) Modifications to thermal neutron reactions on fission products (isotopes of Mo, Tc, Rh, Ag, Cs, Nd, Sm, Eu) and neutron absorber materials (Cd, Gd); (6) Improved minor actinide evaluations for isotopes of U, Np, Pu, and Am (we are not making changes to the major actinides (235,238)U and (239)Pu at this point, except for delayed neutron data and covariances, and instead we intend to update them after a further period of research in experiment and theory), and our adoption of JENDL-4.0 evaluations for isotopes of Cm, Bk, Cf, Es; Fm; and some other minor actinides; (7) Fission energy release evaluations; (8) Fission product yield advances for fission-spectrum neutrons and 14 MeV neutrons incident on (239)Pu; and (9) A new decay data sublibrary. Integral validation testing of the ENDF/B-VII.1 library is provided for a variety of quantities: For nuclear criticality, the VII.1 library maintains the generally-good performance seen for VII.0 for a wide

  15. Nuclear decay following deep inelastic scattering of 470 GeV muons

    Energy Technology Data Exchange (ETDEWEB)

    Adams, M.R.; Aied, S.; Anthony, P.L.; Averill, D.A.; Baker, M.D.; Baller, B.R.; Banerjee, A.; Bhatti, A.A.; Bratzler, U.; Braun, H.M.; Breidung, H.; Busza, W.; Carroll, T.J.; Clark, H.L.; Conrad, J.M.; Davisson, R.; Derado, I.; Dhawan, S.K.; Dietrich, F.S.; Dougherty, W.; Dreyer, T.; Eckardt, V.; Ecker, U.; Erdmann, M.; Fang, G.Y.; Figiel, J.; Finlay, R.W.; Gebauer, H.J.; Geesaman, D.F.; Griffioen, K.A.; Guo, R.S.; Haas, J.; Halliwell, C.; Hantke, D.; Hicks, K.H.; Hughes, V.W.; Jackson, H.E.; Jaffe, D.E.; Jancso, G.; Jansen, D.M.; Jin, Z.; Kaufman, S.; Kennedy, R.D.; Kinney, E.R.; Kirk, T.; Kobrak, H.G.E.; Kotwal, A.V.; Kunori, S.; Lord, J.J.; Lubatti, H.J.; McLeod, D.; Madden, P.; Magill, S.; Manz, A.; Melanson, H.; Michael, D.G.; Montgomery, H.E.; Morfin, J.G.; Nickerson, R.B.; O`Day, S.; Olkiewicz, K.; Osborne, L.; Otten, R.; Papavassiliou, V.; Pawlik, B.; Pipkin, F.M.; Potterveld, D.H.; Ramberg, E.J.; Roeser, A.; Ryan, J.J.; Salgado, C.W.; Salvarani, A.; Schellman, H.; Schmitt, M.; Schmitz, N.; Schueler, K.P.; Siegert, G.; Skuja, A.; Snow, G.A.; Soeldner-Rembold, S.; Spentzouris, P.; Stier, H.E.; Stopa, P.; Swanson, R.A.; Venkataramania, H.; Wilhelm, M.; Wilson, R.; Wittek, W.; Wolbers, S.A.; Zghiche, A.; Zhao, T. [Albert-Ludwigs-Universitaet Freiburg i. Br. (Germany)]|[Argonne National Laboratory, Argonne, Illinois 60439 (United States)]|[University of California, San Diego, California 92093 (United States)]|[Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)]|[Harvard University, Cambridge, Massachusetts 02138 (United States)]|[University of Illinois, Chicago, Illinois 60680 (United States)]|[Institute for Nuclear Physics, Krakow (Poland)]|[Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)]|[University of Maryland, College Park, Maryland 20742 (United States)]|[Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); (E665 Collaboration)

    1995-06-26

    We detected 1--10 MeV neutrons at laboratory angles from 80{degree} to 140{degree} in coincidence with 470 GeV muons deep inelastically scattered from H, D, C, Ca, and Pb targets. The neutron energy spectrum for Pb can be fitted with two components with temperature parameters of 0.7 and 5.0 MeV. The average neutron multiplicity for 40{lt}{nu}{lt}400 GeV is about 5 for Pb, and less than 2 for Ca and C. These data are consistent with a process in which the emitted hadrons do not interact with the rest of the nucleus within distances smaller than the radius of Ca, but do interact within distances on the order of the radius of Pb in the measured kinematic range. For all targets the lack of high nuclear excitation is surprising.

  16. Modeling of the mechano-chemical behaviour of the nuclear pore complex: current research and perspectives.

    Science.gov (United States)

    Garcia, Alberto; Rodriguez Matas, Jose F; Raimondi, Manuela T

    2016-10-10

    Recent evidence suggests that mechanical deformation of the cell nucleus regulates the nuclear import of the transcriptional activators of genes involved in primary physiological cell responses such as stem cell differentiation. In addition, this nuclear mechanosensing response is de-regulated in pathological states, such as cancer and neurodegeneration. One hypothesis that could greatly advance the field is that the deformation of the nuclear envelope activates nuclear pore complexes through a direct mechanical link. The understanding of this possible mechanism for nuclear pore complex stretch-activation entails studying the mechanical connection of this complex to the nuclear envelope at the nanoscale. The nanomechanics of the nuclear pore complex is thus emerging as a novel research field, bridging nanoscience with nanotechnology. This review examines the frontier of research methodologies that are potentially useful for building a computational model of this interaction. This includes, for example, electron tomography to assess the geometrical features of the nuclear pore complex and nanoindentation to estimate its mechanical properties and that of the nuclear envelope. In order to summarize the state-of-the-art and perspectives in the field of NPC nanomechanics, this review covers highly interdisciplinary experimental and theoretical research methodologies pertaining to the fields of physics, chemistry, biology, materials and mechanics.

  17. Change of nuclear configurations in the neutrinoless double-$\\beta$ decay of $^{130}$Te $\\rightarrow$ $^{130}$Xe and $^{136}$Xe $\\rightarrow$ $^{136}$Ba

    CERN Document Server

    Entwisle, J P; Tamii, A; Adachi, S; Aoi, N; Clark, J A; Freeman, S J; Fujita, H; Fujita, Y; Furuno, T; Hashimoto, T; Hoffman, C R; Ideguchi, E; Ito, T; Iwamoto, C; Kawabata, T; Liu, B; Miura, M; Ong, H J; Schiffer, J P; Sharp, D K; Süsoy, G; Suzuki, T; Szwec, S V; Takaki, M; Tsumura, M; Yamamoto, T

    2016-01-01

    The change in the configuration of valence protons between the initial and final states in the neutrinoless double-$\\beta$ decay of $^{130}$Te $\\rightarrow$ $^{130}$Xe and of $^{136}$Xe $\\rightarrow$ $^{136}$Ba has been determined by measuring the cross sections of the ($d$,$^3$He) reaction with 101-MeV deuterons. Together with our recent determination of the relevant neutron configurations involved in the process, a quantitative comparison with the latest shell-model and interacting-boson-model calculations reveals significant discrepancies. These are the same calculations used to determine the nuclear matrix elements governing the rate of neutrinoless double-$\\beta$ decay in these systems.

  18. BAF53 Forms Distinct Nuclear Complexes and Functions as a Critical c-Myc-Interacting Nuclear Cofactor for Oncogenic Transformation

    Science.gov (United States)

    Park, Jeonghyeon; Wood, Marcelo A.; Cole, Michael D.

    2002-01-01

    The c-Myc oncoprotein functions as a transcription factor that can transform normal cells into tumor cells, as well as playing a direct role in normal cell proliferation. The c-Myc protein transactivates cellular promoters by recruiting nuclear cofactors to chromosomal sites through an N-terminal transactivation domain. We have previously reported the identification and functional characterization of four different c-Myc cofactors: TRRAP, hGCN5, TIP49, and TIP48. Here we present the identification and characterization of the actin-related protein BAF53 as a c-Myc-interacting nuclear cofactor that forms distinct nuclear complexes. In addition to the human SWI/SNF-related BAF complex, BAF53 forms a complex with TIP49 and TIP48 and a separate biochemically distinct complex containing TRRAP and a histone acetyltransferase which does not contain TIP60. Using deletion mutants of BAF53, we show that BAF53 is critical for c-Myc oncogenic activity. Our results indicate that BAF53 plays a functional role in c-Myc-interacting nuclear complexes. PMID:11839798

  19. Investigations of nuclear structure and nuclear reactions induced by complex projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.

    1990-01-01

    This report discusses research in the following areas: nuclear structure; fusion reactions near and below the barrier; incomplete fusion and fragmentation reactions; and instrumentation and analysis. (LSP).

  20. Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage

    Science.gov (United States)

    Ternovykh, Mikhail; Tikhomirov, Georgy; Saldikov, Ivan; Gerasimov, Alexander

    2017-09-01

    Decay heat power of actinides and fission products from spent nuclear fuel of power VVER-1000 type reactors at long-term storage is calculated. Two modes of storage are considered: mode in which single portion of actinides or fission products is loaded in storage facility, and mode in which actinides or fission products from spent fuel of one VVER reactor are added every year in storage facility during 30 years and then accumulated nuclides are stored without addition new nuclides. Two values of fuel burnup 40 and 70 MW·d/kg are considered for the mode of storage of single fuel unloading. For the mode of accumulation of spent fuel with subsequent storage, one value of burnup of 70 MW·d/kg is considered. Very long time of storage 105 years accepted in calculations allows to simulate final geological disposal of radioactive wastes. Heat power of fission products decreases quickly after 50-100 years of storage. The power of actinides decreases very slow. In passing from 40 to 70 MW·d/kg, power of actinides increases due to accumulation of higher fraction of 244Cm. These data are important in the back end of fuel cycle when improved cooling system of the storage facility will be required along with stronger radiation protection during storage, transportation and processing.

  1. The CCR4-NOT complex physically and functionally interacts with TRAMP and the nuclear exosome.

    Directory of Open Access Journals (Sweden)

    Nowel Azzouz

    Full Text Available BACKGROUND: Ccr4-Not is a highly conserved multi-protein complex consisting in yeast of 9 subunits, including Not5 and the major yeast deadenylase Ccr4. It has been connected functionally in the nucleus to transcription by RNA polymerase II and in the cytoplasm to mRNA degradation. However, there has been no evidence so far that this complex is important for RNA degradation in the nucleus. METHODOLOGY/PRINCIPAL FINDINGS: In this work we point to a new role for the Ccr4-Not complex in nuclear RNA metabolism. We determine the importance of the Ccr4-Not complex for the levels of non-coding nuclear RNAs, such as mis-processed and polyadenylated snoRNAs, whose turnover depends upon the nuclear exosome and TRAMP. Consistently, mutation of both the Ccr4-Not complex and the nuclear exosome results in synthetic slow growth phenotypes. We demonstrate physical interactions between the Ccr4-Not complex and the exosome. First, Not5 co-purifies with the exosome. Second, several exosome subunits co-purify with the Ccr4-Not complex. Third, the Ccr4-Not complex is important for the integrity of large exosome-containing complexes. Finally, we reveal a connection between the Ccr4-Not complex and TRAMP through the association of the Mtr4 helicase with the Ccr4-Not complex and the importance of specific subunits of Ccr4-Not for the association of Mtr4 with the nuclear exosome subunit Rrp6. CONCLUSIONS/SIGNIFICANCE: We propose a model in which the Ccr4-Not complex may provide a platform contributing to dynamic interactions between the nuclear exosome and its co-factor TRAMP. Our findings connect for the first time the different players involved in nuclear and cytoplasmic RNA degradation.

  2. Chm7 and Heh1 collaborate to link nuclear pore complex quality control with nuclear envelope sealing.

    Science.gov (United States)

    Webster, Brant M; Thaller, David J; Jäger, Jens; Ochmann, Sarah E; Borah, Sapan; Lusk, C Patrick

    2016-11-15

    The integrity of the nuclear envelope barrier relies on membrane remodeling by the ESCRTs, which seal nuclear envelope holes and contribute to the quality control of nuclear pore complexes (NPCs); whether these processes are mechanistically related remains poorly defined. Here, we show that the ESCRT-II/III chimera, Chm7, is recruited to a nuclear envelope subdomain that expands upon inhibition of NPC assembly and is required for the formation of the storage of improperly assembled NPCs (SINC) compartment. Recruitment to sites of NPC assembly is mediated by its ESCRT-II domain and the LAP2-emerin-MAN1 (LEM) family of integral inner nuclear membrane proteins, Heh1 and Heh2. We establish direct binding between Heh2 and the "open" forms of both Chm7 and the ESCRT-III, Snf7, and between Chm7 and Snf7. Interestingly, Chm7 is required for the viability of yeast strains where double membrane seals have been observed over defective NPCs; deletion of CHM7 in these strains leads to a loss of nuclear compartmentalization suggesting that the sealing of defective NPCs and nuclear envelope ruptures could proceed through similar mechanisms.

  3. Preparation of the Human Cytomegalovirus Nuclear Egress Complex and Associated Proteins.

    Science.gov (United States)

    Sharma, Mayuri; Kamil, Jeremy P; Coen, Donald M

    2016-01-01

    Herpesviruses, like most DNA viruses, replicate their genomes in the host cell nucleus. Their DNA is then packaged and assembled into viral nucleocapsids, which, in most cases, are too large to pass through the nuclear pore complex. Instead, herpesviruses use a complex multistep pathway, termed nuclear egress, to exit the nucleus. Key players in this process include two conserved viral proteins that form the nuclear egress complex (NEC). In human cytomegalovirus, these NEC proteins are UL50, embedded in the inner nuclear membrane, and its nucleoplasmic partner UL53. Both are essential for viral nuclear egress. However, other viral components as well as host nuclear envelope proteins may also participate in nuclear egress. Identifying these viral and cellular factors may provide important insight into the herpesvirus lifecycle and its relationship to the underlying, yet still-mysterious, host nuclear egress pathway. We developed an immunoprecipitation-based protocol, described herein, to identify protein-protein interactions involving the NEC from the nuclear fraction of infected cells that express an epitope-tagged version of NEC subunit UL53.

  4. Nuclear pore complex assembly and maintenance in POM121- and gp210-deficient cells

    DEFF Research Database (Denmark)

    Stavru, Fabrizia; Nautrup-Pedersen, Gitte; Cordes, Volker C

    2006-01-01

    So far, POM121 and gp210 are the only known anchoring sites of vertebrate nuclear pore complexes (NPCs) within the lipid bilayer of the nuclear envelope (NE) and, thus, are excellent candidates for initiating the NPC assembly process. Indeed, we demonstrate that POM121 can recruit several...

  5. Extracting partial decay rates of helium from complex rotation: autoionizing resonances of the one-dimensional configurations

    CERN Document Server

    Zimmermann, Klaus; Jörder, Felix; Heitz, Nicolai; Schmidt, Maximilian; Bouri, Celsus; Rodriguez, Alberto; Buchleitner, Andreas

    2014-01-01

    Partial autoionization rates of doubly excited one-dimensional helium in the collinear Zee and eZe configuration are obtained by means of the complex rotation method. The approach presented here relies on a projection of back-rotated resonance wave functions onto singly ionized $\\textrm{He}^{+}$ channel wave functions and the computation of the corresponding particle fluxes. In spite of the long-range nature of the Coulomb potential between the electrons and the nucleus, an asymptotic region where the fluxes are stationary is clearly observed. Low-lying doubly excited states are found to decay predomintantly into the nearest single-ionization continuum. This approach paves the way for a systematic analysis of the decay rates observed in higher-dimensional models, and of the role of electronic correlations and atomic structure in recent photoionization experiments.

  6. Cleave to Leave : Structural Insights into the Dynamic Organization of the Nuclear Pore Complex

    NARCIS (Netherlands)

    Dokudovskaya, Svetlana; Veenhoff, Liesbeth M.; Rout, Michael P.

    2002-01-01

    A detailed understanding of the fine structure of the nuclear pore complex has remained elusive. Now, studies on a small protein domain have shed light on the dynamic organization of this massive assembly.

  7. Virtual enterprise model for the electronic components business in the Nuclear Weapons Complex

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, T.J.; Long, K.S.; Sayre, J.A. [Sandia National Labs., Albuquerque, NM (United States); Hull, A.L. [Sandia National Labs., Livermore, CA (United States); Carey, D.A.; Sim, J.R.; Smith, M.G. [Allied-Signal Aerospace Co., Kansas City, MO (United States). Kansas City Div.

    1994-08-01

    The electronic components business within the Nuclear Weapons Complex spans organizational and Department of Energy contractor boundaries. An assessment of the current processes indicates a need for fundamentally changing the way electronic components are developed, procured, and manufactured. A model is provided based on a virtual enterprise that recognizes distinctive competencies within the Nuclear Weapons Complex and at the vendors. The model incorporates changes that reduce component delivery cycle time and improve cost effectiveness while delivering components of the appropriate quality.

  8. Virtual enterprise model for the electronic components business in the Nuclear Weapons Complex

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, T.J.; Long, K.S.; Sayre, J.A. [Sandia National Labs., Albuquerque, NM (United States); Hull, A.L. [Sandia National Labs., Livermore, CA (United States); Carey, D.A.; Sim, J.R.; Smith, M.G. [Allied-Signal Aerospace Co., Kansas City, MO (United States). Kansas City Div.

    1994-08-01

    The electronic components business within the Nuclear Weapons Complex spans organizational and Department of Energy contractor boundaries. An assessment of the current processes indicates a need for fundamentally changing the way electronic components are developed, procured, and manufactured. A model is provided based on a virtual enterprise that recognizes distinctive competencies within the Nuclear Weapons Complex and at the vendors. The model incorporates changes that reduce component delivery cycle time and improve cost effectiveness while delivering components of the appropriate quality.

  9. Integrating complex functions: coordination of nuclear pore complex assembly and membrane expansion of the nuclear envelope requires a family of integral membrane proteins.

    Science.gov (United States)

    Schneiter, Roger; Cole, Charles N

    2010-01-01

    The nuclear envelope harbors numerous large proteinaceous channels, the nuclear pore complexes (NPCs), through which macromolecular exchange between the cytosol and the nucleoplasm occurs. This double-membrane nuclear envelope is continuous with the endoplasmic reticulum and thus functionally connected to such diverse processes as vesicular transport, protein maturation and lipid synthesis. Recent results obtained from studies in Saccharomyces cerevisiae indicate that assembly of the nuclear pore complex is functionally dependent upon maintenance of lipid homeostasis of the ER membrane. Previous work from one of our laboratories has revealed that an integral membrane protein Apq12 is important for the assembly of functional nuclear pores. Cells lacking APQ12 are viable but cannot grow at low temperatures, have aberrant NPCs and a defect in mRNA export. Remarkably, these defects in NPC assembly can be overcome by supplementing cells with a membrane fluidizing agent, benzyl alcohol, suggesting that Apq12 impacts the flexibility of the nuclear membrane, possibly by adjusting its lipid composition when cells are shifted to a reduced temperature. Our new study now expands these findings and reveals that an essential membrane protein, Brr6, shares at least partially overlapping functions with Apq12 and is also required for assembly of functional NPCs. A third nuclear envelope membrane protein, Brl1, is related to Brr6, and is also required for NPC assembly. Because maintenance of membrane homeostasis is essential for cellular survival, the fact that these three proteins are conserved in fungi that undergo closed mitoses, but are not found in metazoans or plants, may indicate that their functions are performed by proteins unrelated at the primary sequence level to Brr6, Brl1 and Apq12 in cells that disassemble their nuclear envelopes during mitosis.

  10. Investigations of nuclear structure and nuclear reactions induced by complex projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.

    1991-01-01

    The research program of our group touches five areas of nuclear physics: (1) Nuclear structure studies at high spin; (2) Studies at the interface between structure and reactions; (3) Production and study of hot nuclei; (4) Incomplete fusion and fragmentation reactions; and (5) Development and use of novel techniques and instrumentation in the above areas of research. The papers from these areas are discussed in this report.

  11. Route from spontaneous decay to complex multimode dynamics in cavity QED

    CERN Document Server

    Krimer, Dmitry O; Rotter, Stefan; Tureci, Hakan E

    2013-01-01

    We study the non-Markovian quantum dynamics of an emitter inside an open multimode cavity, focusing on the case where the emitter is resonant with high-frequency cavity modes. Based on a Green's function technique suited for open photonic structures, we study the crossovers between three distinct regimes as the coupling strength is gradually increased: (i) overdamped decay with a time scale given by the Purcell modified decay rate, (ii) underdamped oscillations with a time scale given by the effective vacuum Rabi frequency, and (iii) pulsed revivals. The final multimode strong coupling regime (iii) gives rise to quantum revivals of the atomic inversion on a time scale associated with the cavity round-trip time. We show that the crucial parameter to capture the crossovers between these regimes is the nonlinear Lamb shift, accounted for exactly in our formalism.

  12. Controlling Halo-chaos Complexity for Nuclear Power System and Managing High Technology Field

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Variability is one of most important features of complexity in the complex systems because of itssensitivities to small perturbation. Various possible competing behaviors in the systems provide greatflexibility in controlling dynamical complexity and can manage/select a desired behavior for applicationsin real world. In many high-tech fields, how to control or manage complexity is of significant andchallenge issue. Taking as a typical example, accelerator driven clean nuclear power system (ADS) is one

  13. Components of coated vesicles and nuclear pore complexes share a common molecular architecture.

    Directory of Open Access Journals (Sweden)

    Damien Devos

    2004-12-01

    Full Text Available Numerous features distinguish prokaryotes from eukaryotes, chief among which are the distinctive internal membrane systems of eukaryotic cells. These membrane systems form elaborate compartments and vesicular trafficking pathways, and sequester the chromatin within the nuclear envelope. The nuclear pore complex is the portal that specifically mediates macromolecular trafficking across the nuclear envelope. Although it is generally understood that these internal membrane systems evolved from specialized invaginations of the prokaryotic plasma membrane, it is not clear how the nuclear pore complex could have evolved from organisms with no analogous transport system. Here we use computational and biochemical methods to perform a structural analysis of the seven proteins comprising the yNup84/vNup107-160 subcomplex, a core building block of the nuclear pore complex. Our analysis indicates that all seven proteins contain either a beta-propeller fold, an alpha-solenoid fold, or a distinctive arrangement of both, revealing close similarities between the structures comprising the yNup84/vNup107-160 subcomplex and those comprising the major types of vesicle coating complexes that maintain vesicular trafficking pathways. These similarities suggest a common evolutionary origin for nuclear pore complexes and coated vesicles in an early membrane-curving module that led to the formation of the internal membrane systems in modern eukaryotes.

  14. The nuclear pore complex acts as a master switch for nuclear and cell differentiation

    Science.gov (United States)

    Iwamoto, Masaaki; Hiraoka, Yasushi; Haraguchi, Tokuko

    2015-01-01

    Cell differentiation is associated with the functional differentiation of the nucleus, in which alteration of the expression profiles of transcription factors occurs to destine cell fate. Nuclear transport machineries, such as importin-α, have also been reported as critical factors that induce cell differentiation. Using various fluorescence live cell imaging methods, including time-lapse imaging, FRAP analysis and live-cell imaging associated correlative light and electron microscopy (Live CLEM) of Tetrahymena, a unicellular ciliated protozoan, we have recently discovered that type switching of the NPC is the earliest detectable event of nuclear differentiation. Our studies suggest that this type switching of the NPC directs the fate of the nucleus to differentiate into either a macronucleus or a micronucleus. Our findings in this organism may provide new insights into the role of the NPC in controlling nuclear functions in general in eukaryotes, including controlling cell fate leading to cell differentiation in multicellular metazoa. PMID:26479399

  15. Characterization of a nuclear pore protein sheds light on the roles and composition of the Toxoplasma gondii nuclear pore complex.

    Science.gov (United States)

    Courjol, Flavie; Mouveaux, Thomas; Lesage, Kevin; Saliou, Jean-Michel; Werkmeister, Elisabeth; Bonabaud, Maurine; Rohmer, Marine; Slomianny, Christian; Lafont, Franck; Gissot, Mathieu

    2017-01-30

    The nuclear pore is a key structure in eukaryotes regulating nuclear-cytoplasmic transport as well as a wide range of cellular processes. Here, we report the characterization of the first Toxoplasma gondii nuclear pore protein, named TgNup302, which appears to be the orthologue of the mammalian Nup98-96 protein. We produced a conditional knock-down mutant that expresses TgNup302 under the control of an inducible tetracycline-regulated promoter. Under ATc treatment, a substantial decrease of TgNup302 protein in inducible knock-down (iKD) parasites was observed, causing a delay in parasite proliferation. Moreover, the nuclear protein TgENO2 was trapped in the cytoplasm of ATc-treated mutants, suggesting that TgNup302 is involved in nuclear transport. Fluorescence in situ hybridization revealed that TgNup302 is essential for 18S RNA export from the nucleus to the cytoplasm, while global mRNA export remains unchanged. Using an affinity tag purification combined with mass spectrometry, we identified additional components of the nuclear pore complex, including proteins potentially interacting with chromatin. Furthermore, reverse immunoprecipitation confirmed their interaction with TgNup302, and structured illuminated microscopy confirmed the NPC localization of some of the TgNup302-interacting proteins. Intriguingly, facilitates chromatin transcription complex (FACT) components were identified, suggesting the existence of an NPC-chromatin interaction in T. gondii. Identification of TgNup302-interacting proteins also provides the first glimpse at the NPC structure in Apicomplexa, suggesting a structural conservation of the NPC components between distant eukaryotes.

  16. Diverse role of three tyrosines in binding of the RNA 5' cap to the human nuclear cap binding complex.

    Science.gov (United States)

    Worch, Remigiusz; Jankowska-Anyszka, Marzena; Niedzwiecka, Anna; Stepinski, Janusz; Mazza, Catherine; Darzynkiewicz, Edward; Cusack, Stephen; Stolarski, Ryszard

    2009-01-16

    The heterodimeric nuclear cap-binding complex (CBC) specifically recognizes the monomethylguanosine 5' cap structure of the eukaryotic RNA polymerase II transcripts such as mRNA and U snRNA. The binding is essential for nuclear maturation of mRNA, for nuclear export of U snRNA in metazoans, and for nonsense-mediated decay of mRNA and the pioneer round of translation. We analysed the recognition of the cap by native human CBC and mutants in which each tyrosine that stacks with the 7-methylguanosine moiety was replaced by phenylalanine or alanine and both tyrosines were replaced by phenylalanines. The equilibrium association constants (K(as)) for two selected cap analogues, P(1)-7-methylguanosine-5' P(3)-guanosine-5' triphosphate and 7-methylguanosine triphosphate, were determined by two independent methods, fluorescence titration and surface plasmon resonance. We could distinguish two tyrosines, Y43 and Y20, in stabilization of the cap inside the CBC-binding pocket. In particular, lack of Y20 in CBC leads to a greater affinity of the mono- than the dinucleotide cap analogue, in contrast to the wild-type protein. A crucial role of cation-pi stacking in the mechanism of the specific cap recognition by CBC was postulated from the comparison of the experimentally derived Gibbs free binding energy (DeltaG degrees) with the stacking energy (DeltaE) of the 7-methylguanosine/Y binary and ternary complexes calculated by the Møller-Plesset second-order perturbation method. The resulting kinetic model of the association between the capped RNA and CBC, based on the experimental data and quantum calculations, is discussed with respect to the "CBC-to-eukaryotic initiation factor 4E handoff" of mRNA.

  17. Choreography of importin-α/CAS complex assembly and disassembly at nuclear pores.

    Science.gov (United States)

    Sun, Changxia; Fu, Guo; Ciziene, Danguole; Stewart, Murray; Musser, Siegfried M

    2013-04-23

    Nuclear pore complexes (NPCs) mediate the exchange of macromolecules between the cytoplasm and the nucleoplasm. Soluble nuclear transport receptors bind signal-dependent cargos to form transport complexes that diffuse through the NPC and are then disassembled. Although transport receptors enable the NPC's permeability barrier to be overcome, directionality is established by complex assembly and disassembly. Here, we delineate the choreography of importin-α/CAS complex assembly and disassembly in permeabilized cells, using single-molecule fluorescence resonance energy transfer and particle tracking. Monitoring interaction sequences in intact NPCs ensures spatiotemporal preservation of structures and interactions critical for activity in vivo. We show that key interactions between components are reversible, multiple outcomes are often possible, and the assembly and disassembly of complexes are precisely controlled to occur at the appropriate place and time. Importin-α mutants that impair interactions during nuclear import were used together with cytoplasmic Ran GTPase-activating factors to demonstrate that importin-α/CAS complexes form in the nuclear basket region, at the termination of protein import, and disassembly of importin-α/CAS complexes after export occurs in the cytoplasmic filament region of the NPC. Mathematical models derived from our data emphasize the intimate connection between transport and the coordinated assembly and disassembly of importin-α/CAS complexes for generating productive transport cycles.

  18. A world class nuclear research reactor complex for South Africa's nuclear future

    Energy Technology Data Exchange (ETDEWEB)

    Keshaw, Jeetesh [South African Young Nuclear Professional Society, PO Box 9396, Centurion, 0157 (South Africa)

    2008-07-01

    South Africa recently made public its rather ambitious goals pertaining to nuclear energy developments in a Draft Policy and Strategy issued for public comment. Not much attention was given to an important tool for nuclear energy research and development, namely a well equipped and maintained research reactor, which on its own does not do justice to its potential, unless it is fitted with all the ancillaries and human resources as most first world countries have. In South Africa's case it is suggested to establish at least one Nuclear Energy Research and Development Centre at such a research reactor, where almost all nuclear energy related research can be carried out on par with some of the best in the world. The purpose of this work is to propose how this could be done, and motivate why it is important that it be done with great urgency, and with full involvement of young professionals, if South Africa wishes to face up to the challenges mentioned in the Draft Strategy and Policy. (authors)

  19. AFM visualization of sub-50nm polyplex disposition to the nuclear pore complex without compromising the integrity of the nuclear envelope

    DEFF Research Database (Denmark)

    Andersen, Helene; Parhamifar, Ladan; Hunter, A Christy

    2016-01-01

    It has been questioned as to whether polyplexes in the cytoplasm can reach the nuclear compartment and if so in what form. By applying atomic force microscopy (AFM) to the nuclear envelope and the nuclear pore complexes, we demonstrate that disposition of polyethylenimine (PEI)/DNA polyplexes...

  20. Nuclear chemistry. Synthesis and detection of a seaborgium carbonyl complex.

    Science.gov (United States)

    Even, J; Yakushev, A; Düllmann, Ch E; Haba, H; Asai, M; Sato, T K; Brand, H; Di Nitto, A; Eichler, R; Fan, F L; Hartmann, W; Huang, M; Jäger, E; Kaji, D; Kanaya, J; Kaneya, Y; Khuyagbaatar, J; Kindler, B; Kratz, J V; Krier, J; Kudou, Y; Kurz, N; Lommel, B; Miyashita, S; Morimoto, K; Morita, K; Murakami, M; Nagame, Y; Nitsche, H; Ooe, K; Qin, Z; Schädel, M; Steiner, J; Sumita, T; Takeyama, M; Tanaka, K; Toyoshima, A; Tsukada, K; Türler, A; Usoltsev, I; Wakabayashi, Y; Wang, Y; Wiehl, N; Yamaki, S

    2014-09-19

    Experimental investigations of transactinoide elements provide benchmark results for chemical theory and probe the predictive power of trends in the periodic table. So far, in gas-phase chemical reactions, simple inorganic compounds with the transactinoide in its highest oxidation state have been synthesized. Single-atom production rates, short half-lives, and harsh experimental conditions limited the number of experimentally accessible compounds. We applied a gas-phase carbonylation technique previously tested on short-lived molybdenum (Mo) and tungsten (W) isotopes to the preparation of a carbonyl complex of seaborgium, the 106th element. The volatile seaborgium complex showed the same volatility and reactivity with a silicon dioxide surface as those of the hexacarbonyl complexes of the lighter homologs Mo and W. Comparison of the product's adsorption enthalpy with theoretical predictions and data for the lighter congeners supported a Sg(CO)6 formulation.

  1. Investigation of the nuclear structure of 33Al through beta-decay of 33Mg to probe the island of inversion

    Science.gov (United States)

    Zidar, Tammy; Griffin Collaboration

    2016-09-01

    Away from the valley of stability, some nuclei have been found to have ground state properties that are different than those naively expected from the nuclear shell model. Around the ``island of inversion'', N = 20 closed shell nucleus 32Mg has large ground state deformations occur in association with intruder configurations from the f7 / 2 shell. The nuclear structure of transitional nuclei, in which the normal and intruder configurations compete, can be used to inform theoretical models used to explain the inversion mechanism. 32Mg is known to have a deformed ground-state configuration, while 34Si displays a normal one. In the present work we studied the intermediate 33Al through the β-decay of 33Mg to clarify conflicting previous results regarding its structure. 33Mg was delivered to the GRIFFIN high-purity germanium γ-ray spectrometer coupled with the SCEPTAR plastic scintillator β particle detector. High efficiency of the GRIFFIN detector provides new γ- γ coincidences to elucidate the excited state structure of 33Al, and its capability to detect weak transitions has provided β-decay branching ratios for the 33Mg -> 33Al -> 33Si decay chain. The Canadian Foundation for Innovation, The National Research Council of Canada and the Natural Sciences and Engineering Research Council of Canada.

  2. A multiprotein nuclear complex connects Fanconi anemia and Bloom syndrome.

    NARCIS (Netherlands)

    Meetei, AR; Sechi, S; Wallisch, M; Yang, D; Young, MK; Joenje, H.; Hoatlin, M.E.

    2003-01-01

    Bloom syndrome (BS) is a genetic disorder associated with dwarfism, immunodeficiency, reduced fertility, and an elevated risk of cancer. To investigate the mechanism of this disease, we isolated from human HeLa extracts three complexes containing the helicase defective in BS, BLM. Interestingly, one

  3. A multiprotein nuclear complex connects Fanconi anemia and Bloom syndrome.

    NARCIS (Netherlands)

    Meetei, AR; Sechi, S; Wallisch, M; Yang, D; Young, MK; Joenje, H.; Hoatlin, M.E.

    2003-01-01

    Bloom syndrome (BS) is a genetic disorder associated with dwarfism, immunodeficiency, reduced fertility, and an elevated risk of cancer. To investigate the mechanism of this disease, we isolated from human HeLa extracts three complexes containing the helicase defective in BS, BLM. Interestingly, one

  4. Post shut-down decay heat removal from nuclear reactor core by natural convection loops in sodium pool

    Energy Technology Data Exchange (ETDEWEB)

    Rajamani, A. [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Sundararajan, T., E-mail: tsundar@iitm.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Prasad, B.V.S.S.S. [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Parthasarathy, U.; Velusamy, K. [Nuclear Engineering Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2016-05-15

    Highlights: • Transient simulations are performed for a worst case scenario of station black-out. • Inter-wrapper flow between various sub-assemblies reduces peak core temperature. • Various natural convection paths limits fuel clad temperatures below critical level. - Abstract: The 500 MWe Indian pool type Prototype Fast Breeder Reactor (PFBR) has a passive core cooling system, known as the Safety Grade Decay Heat Removal System (SGDHRS) which aids to remove decay heat after shut down phase. Immediately after reactor shut down the fission products in the core continue to generate heat due to beta decay which exponentially decreases with time. In the event of a complete station blackout, the coolant pump system may not be available and the safety grade decay heat removal system transports the decay heat from the core and dissipates it safely to the atmosphere. Apart from SGDHRS, various natural convection loops in the sodium pool carry the heat away from the core and deposit it temporarily in the sodium pool. The buoyancy driven flow through the small inter-wrapper gaps (known as inter-wrapper flow) between fuel subassemblies plays an important role in carrying the decay heat from the sub-assemblies to the hot sodium pool, immediately after reactor shut down. This paper presents the transient prediction of flow and temperature evolution in the reactor subassemblies and the sodium pool, coupled with the safety grade decay heat removal system. It is shown that with a properly sized decay heat exchanger based on liquid sodium and air chimney stacks, the post shutdown decay heat can be safely dissipated to atmospheric air passively.

  5. Membrane deformation and scission by the HSV-1 nuclear egress complex

    Science.gov (United States)

    Bigalke, Janna M.; Heuser, Thomas; Nicastro, Daniela; Heldwein, Ekaterina E.

    2014-06-01

    The nuclear egress complex (NEC) of herpesviruses such as HSV-1 is essential for the exit of nascent capsids from the cell nucleus. The NEC drives nuclear envelope vesiculation in cells, but the precise budding mechanism and the potential involvement of cellular proteins are unclear. Here we report that HSV-1 NEC alone is sufficient for membrane budding in vitro and thus represents a complete membrane deformation and scission machinery. It forms ordered coats on the inner surface of the budded vesicles, suggesting that it mediates scission by scaffolding the membrane bud and constricting the neck to the point of scission. The inward topology of NEC-mediated budding in vitro resembles capsid budding into the inner nuclear membrane during HSV-1 infection and nuclear envelope vesiculation in NEC-transfected cells. We propose that the NEC functions as minimal virus-encoded membrane-budding machinery during nuclear egress and does not require additional cellular factors.

  6. Nucleoporins as components of the nuclear pore complex core structure and Tpr as the architectural element of the nuclear basket.

    Science.gov (United States)

    Krull, Sandra; Thyberg, Johan; Björkroth, Birgitta; Rackwitz, Hans-Richard; Cordes, Volker C

    2004-09-01

    The vertebrate nuclear pore complex (NPC) is a macromolecular assembly of protein subcomplexes forming a structure of eightfold radial symmetry. The NPC core consists of globular subunits sandwiched between two coaxial ring-like structures of which the ring facing the nuclear interior is capped by a fibrous structure called the nuclear basket. By postembedding immunoelectron microscopy, we have mapped the positions of several human NPC proteins relative to the NPC core and its associated basket, including Nup93, Nup96, Nup98, Nup107, Nup153, Nup205, and the coiled coil-dominated 267-kDa protein Tpr. To further assess their contributions to NPC and basket architecture, the genes encoding Nup93, Nup96, Nup107, and Nup205 were posttranscriptionally silenced by RNA interference (RNAi) in HeLa cells, complementing recent RNAi experiments on Nup153 and Tpr. We show that Nup96 and Nup107 are core elements of the NPC proper that are essential for NPC assembly and docking of Nup153 and Tpr to the NPC. Nup93 and Nup205 are other NPC core elements that are important for long-term maintenance of NPCs but initially dispensable for the anchoring of Nup153 and Tpr. Immunogold-labeling for Nup98 also results in preferential labeling of NPC core regions, whereas Nup153 is shown to bind via its amino-terminal domain to the nuclear coaxial ring linking the NPC core structures and Tpr. The position of Tpr in turn is shown to coincide with that of the nuclear basket, with different Tpr protein domains corresponding to distinct basket segments. We propose a model in which Tpr constitutes the central architectural element that forms the scaffold of the nuclear basket.

  7. The transmembrane nucleoporin NDC1 is required for targeting of ALADIN to nuclear pore complexes

    Energy Technology Data Exchange (ETDEWEB)

    Yamazumi, Yusuke; Kamiya, Atsushi; Nishida, Ayumu; Nishihara, Ayako [Laboratory of Molecular and Genetic Information, Institute for Molecular and Cellular Bioscience, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Iemura, Shun-ichiro; Natsume, Tohru [Biological Information Research Center (AIST), Japan Biological Information Research Center (JBIC), Aomi 2-41-6, Koutou-ku, Tokyo 135-0064 (Japan); Akiyama, Tetsu, E-mail: akiyama@iam.u-tokyo.ac.jp [Laboratory of Molecular and Genetic Information, Institute for Molecular and Cellular Bioscience, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan)

    2009-11-06

    NDC1 is a transmembrane nucleoporin that is required for NPC assembly and nucleocytoplasmic transport. We show here that NDC1 directly interacts with the nucleoporin ALADIN, mutations of which are responsible for triple-A syndrome, and that this interaction is required for targeting of ALADIN to nuclear pore complexes (NPCs). Furthermore, we show that NDC1 is required for selective nuclear import. Our findings suggest that NDC1-mediated localization of ALADIN to NPCs is essential for selective nuclear protein import, and that abrogation of the interaction between ALADIN and NDC1 may be important for the development of triple-A syndrome.

  8. Dissecting mechanisms of nuclear mRNA surveillance in THO/sub2 complex mutants

    DEFF Research Database (Denmark)

    Rougemaille, Mathieu; Gudipati, Rajani Kanth; Olesen, Jens Raabjerg

    2007-01-01

    The nuclear exosome is involved in numerous RNA metabolic processes. Exosome degradation of rRNA, snoRNA, snRNA and tRNA in Saccharomyces cerevisiae is activated by TRAMP complexes, containing either the Trf4p or Trf5p poly(A) polymerase. These enzymes are presumed to facilitate exosome access...... by appending oligo(A)-tails onto structured substrates. Another role of the nuclear exosome is that of mRNA surveillance. In strains harboring a mutated THO/Sub2p system, involved in messenger ribonucleoprotein particle biogenesis and nuclear export, the exosome-associated 3' 5' exonuclease Rrp6p is required...

  9. Tentative study of nuclear charge radii for neutron-deficient nuclei around the Z = 82 shell from experimental α decay data

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Yibin, E-mail: qyibin@njust.edu.cn [Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094 (China); Department of Physics and Key Laboratory of Modern Acoustics, Nanjing University, Nanjing 210093 (China); Ren, Zhongzhou [Department of Physics and Key Laboratory of Modern Acoustics, Nanjing University, Nanjing 210093 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy-Ion Accelerator, Lanzhou 730000 (China); Kavli Institute for Theoretical Physics China, Beijing 100190 (China)

    2016-01-15

    We tentatively investigate the root-mean-square (rms) nuclear charge radii of odd-A Po and Pb isotopes plus Tl isotopes, particularly concerning these difficultly-detected nuclei along with short lifetimes, via various data on α decay. Within the density-dependent cluster model, the density distributions of studied daughter nuclei are determined by exactly reproducing the corresponding experimental α decay half-lives, which leads the final results of nuclear charge radii. In addition, our recently proposed formula deducing the charge radii is extended to this study for comparison. Whether it concerns the ground or isomeric state of target nuclei, the extracted nuclear charge radii are found to be in good agreement with the measured values. Sequential predictions on the rms charge radii are subsequently made for these neutron-deficient nuclei and especially for the rarely detected Bi isotopic chain, which are expected to be useful for future measurements. Moreover, the variety of α-preformation factors is analyzed in the scheme of valence nucleon number to pursue the further improvement of the model. This may be considered as an effective effort to obtain the charge radii of ground and even low-lying excited states for exotic nuclei near the proton-dripline.

  10. α versus non-α cluster decays of the excited compound nucleus *124Ce using various formulations of the nuclear proximity potential

    Science.gov (United States)

    Kaur, Arshdeep; Chopra, Sahila; Gupta, Raj K.

    2015-06-01

    The earlier study of *124Ce formed in the 32S+92Mo reaction at an above barrier beam energy of 150 MeV, using the pocket formula of Blocki et al. for the nuclear proximity potential in the dynamical cluster-decay model (DCM), is extended to the use of other nuclear interaction potentials derived from the Skyrme energy density functional (SEDF) based on the semiclassical extended Thomas Fermi (ETF) approach under the frozen density approximation. The Skyrme forces used are the old SII, SIII, SIV, SKa, SkM, and SLy4 and new GSkI and KDE0(v1), given for both normal and isospin-rich nuclei. It is found that the α -nucleus structure, over the non-α nucleus structure, is preferred for only two Skyrme forces, the SIII and KDE0(v1). An extended intermediate mass fragments (IMFs) window, along with the new decay region of heavy mass fragments (HMFs) and the near-symmetric and symmetric fission fragments which, on adding the complementary heavy fragments, corresponds to (A /2 )±12 mass region of the fusion-fission (ff) process, are predicted by considering cross sections of orders observed in the experiment under study. For the predicted (total) fusion cross section, the survival probability Psurv of the compound nucleus (CN) against fission is shown to be very small because of the very large predicted ff component. On the other hand, the CN formation probability PCN is found to be nearly equal to 1, and hence the decay under study is a pure CN decay for all the nuclear potentials considered, since the estimated noncompound nucleus (nCN) content is almost negligible. We have also applied the extended-Wong model of Gupta and collaborators, and find that the ℓmax values and total fusion cross sections are of the same order as for the DCM. Thus, the extended-Wong model, which describes only the total fusion cross section in terms of the barrier characteristics of the entrance channel nuclei, could be useful for initial experimental studies to be fully treated using the DCM

  11. Nuclear distributions of NUP62 and NUP214 suggest architectural diversity and spatial patterning among nuclear pore complexes.

    Directory of Open Access Journals (Sweden)

    Yayoi Kinoshita

    Full Text Available The shape of nuclei in many adherent cultured cells approximates an oblate ellipsoid, with contralateral flattened surfaces facing the culture plate or the medium. Observations of cultured cell nuclei from orthogonal perspectives revealed that nucleoporin p62 (NUP62 and nucleoporin 214 (NUP214 are differentially distributed between nuclear pore complexes on the flattened surfaces and peripheral rim of the nucleus. High resolution stimulated emission depletion (STED immunofluorescence microscopy resolved individual NPCs, and suggested both heterogeneity and microheterogeneity in NUP62 and NUP214 immunolabeling among in NPC populations. Similar to nuclear domains and interphase chromosome territories, architectural diversity and spatial patterning of NPCs may be an intrinsic property of the nucleus that is linked to the functions and organization of underlying chromatin.

  12. Quantum chemical interpretation of ultrafast luminescence decay and intersystem crossings in rhenium(I) carbonyl bipyridine complexes.

    Science.gov (United States)

    Gourlaouen, Christophe; Eng, Julien; Otsuka, Miho; Gindensperger, Etienne; Daniel, Chantal

    2015-01-13

    Ultrafast luminescence decay and intersystem crossing processes through the seven low-lying singlet and triplet excited states of [Re (X)(CO)3(bpy)] (X = Cl, Br, I; bpy = 2,2'-bipyridine) are interpreted on the basis of time-dependent density functional theory (TD-DFT) electronic structure calculations performed in acetonitrile and including spin-orbit coupling (SOC) effects within the zeroth-order approximation. It is shown that the red shift of the lowest part of the spectra by SOC increases from X = Cl (0.06 eV) to X = Br (0.09 eV) and X = I (0.18 eV) due to the participation of the triplet sublevels to the absorption. The six lowest "spin-orbit" states remain largely triplet in character and the maximum of absorption is not drastically affected by SOC. While the energy of the excited states is affected by SOC, the character of these states is not significantly modified: SOC mixes states of the same nature, namely metal-to-ligand-charge-transfer/halide-to-ligand-charge-transfer (MLCT/XLCT). This mixing can be large, however, as illustrated by the S1/T2 (a(1)A″/a(3)A') mixing that amounts to about 50:50 within the series Cl > Br > I. On the basis of the optimized structures of the six lowest excited states an interpretation of the emission signals detected by ultrafast luminescence spectroscopy is proposed. It is shown that whereas the experimental Stokes shift of 6000 cm(-1) observed for the three complexes is well reproduced without SOC correction for the Cl and Br complexes, SOC effects have to be taken into account for the iodide complex. The early signal of ultrafast luminescence detected immediately after absorption at 400 nm to the S2 state, covering the 500-550 nm energy domain and characterized by a decay τ1 = 85 fs (X = Cl) and 128 fs (X = Br), is attributed to S2 calculated at 505 and 522 nm, respectively, and to some extend to T3 by SOC. The intermediate band observed at longer time-scale between 550 and 600 nm with emissive decay time τ2 = 340 fs

  13. MIRD radionuclide data and decay schemes

    CERN Document Server

    Eckerman, Keith F

    2007-01-01

    For all physicians, scientists, and physicists working in the nuclear medicine field, the MIRD: Radionuclide Data and Decay Schemes updated edition is an essential sourcebook for radiation dosimetry and understanding the properties of radionuclides. Includes CD Table of Contents Decay schemes listed by atomic number Radioactive decay processes Serial decay schemes Decay schemes and decay tables This essential reference for nuclear medicine physicians, scientists and physicists also includes a CD with tabulations of the radionuclide data necessary for dosimetry calculations.

  14. Evaluated decay data for 206TI.

    Energy Technology Data Exchange (ETDEWEB)

    Kondev, F. G.; Nuclear Engineering Division

    2007-01-03

    Evaluated decay data for the {sup 206}Tl nuclide are presented, including recommended values for the half-life, {beta}- and {gamma}-ray emission energies and probabilities. Data on X-ray radiations, Auger and conversion electron energies and emission probabilities are also tabulated. Carefully evaluated data for radioactive nuclides refer to complex nuclear level schemes and tables of numerical values, which quantify fundamental nuclear structure information such as level energies and quantum numbers, lifetimes, decay modes, and other associated properties. These data are not only at the core of basic nuclear structure and nuclear astrophysics research, but they are also relevant to many applied technologies, including nuclear energy production, reactor design and safety, medical diagnostic and radiotherapy, health physics, environmental research and monitoring, safeguards and material analysis. The evaluation process results in numerous sets of recommended values on half-lives, radiation energies and emission probabilities. The work on evaluation of decay properties of {sup 206}Tl was completed in September 2006 with a literature cut off by the same date. The Saisinuc software (2002BeXX) and associated supporting programs were used in assembling the data following the established protocol within the International Decay Data Evaluation Project (DDEP) collaboration.

  15. The Need for a Strong Science and Technology Program in the Nuclear Weapons Complex for the 21st Century

    Energy Technology Data Exchange (ETDEWEB)

    Garaizar, Xabier [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2009-07-02

    In this paper I argue for the need for a strong Science and Technology program in the Nuclear Weapons Complex as the basis for maintaining a credible deterrence capability. The current Nuclear Posture Review establishes a New Triad as the basis for the United States deterrence strategy in a changing security environment. A predictive science capability is at the core of a credible National Nuclear Weapons program in the 21st Century. In absence of nuclear testing, the certification of our current Nuclear Weapons relies on predictive simulations and quantification of the associated simulation uncertainties. In addition, a robust nuclear infrastructure needs an active research and development program that considers all the required nuclear scenarios, including new configurations for which there is no nuclear test data. This paper also considers alternative positions to the need for a Science and Technology program in the Nuclear Weapons complex.

  16. Nuclear electromagnetic moments of the ground states of /sup 148/Pm and /sup 210/Bi calculated with phenomenological wave functions derived from analyses of. beta. -decay experiments

    Energy Technology Data Exchange (ETDEWEB)

    Rosso, O.A.; Szybisz, L.

    1983-12-01

    The magnetic dipole and electric quadrupole moments of the ground states of /sup 148/Pm and /sup 210/Bi are evaluated with phenomenological wave functions derived from ..beta..-decay studies published in previous works. It is found that these wave functions account satisfactorily for the experimental data of both nuclear moments of the /sup 210/Bi ground state. In the case of /sup 148/Pm, while the calculated value of the electric quadrupole moment is not inconsistent with the experimental data, a strong disagreement between theory and experiment is found for the magnetic dipole moment. We attribute this failure to the use of a too small configuration space for the expansion of the nuclear wave function of /sup 148/Pm.

  17. Nuclear electromagnetic moments of the ground states of148Pm and210Bi calculated with phenomenological wave functions derived from analyses of β-decay experiments

    Science.gov (United States)

    Rosso, O. A.; Szybisz, L.

    1983-10-01

    The magnetic dipole and electric quadrupole moments of the ground states of148Pm and210Bi are evaluated with phenomenological wave functions derived from β-decay studies published in previous works. It is found that these wave functions account satisfactorily for the experimental data of both nuclear moments of the210Bi ground state. In the case of148Pm, while the calculated value of the electric quadrupole moment is not inconsistent with the experimental data, a strong disagreement between theory and experiment is found for the magnetic dipole moment. We attribute this failure to the use of a too small configuration space for the expansion of the nuclear wave function of148Pm.

  18. Glutarimidedioxime. A complexing and reducing reagent for plutonium recovery from spent nuclear fuel reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Xian, Liang [China Institute of Atomic Energy, Beijing (China). Radiochemistry Dept.; Tian, Guoxin [China Institute of Atomic Energy, Beijing (China). Radiochemistry Dept.; Lawrence Berkeley National Laboratory, Berkeley, CA (United States). Chemical Sciences Div.; Beavers, Christine M.; Teat, Simon J. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States). Advanced Light Source; Shuh, David K. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States). Chemical Sciences Div.

    2016-04-04

    Efficient separation processes for recovering uranium and plutonium from spent nuclear fuel are essential to the development of advanced nuclear fuel cycles. The performance characteristics of a new salt-free complexing and reducing reagent, glutarimidedioxime (H{sub 2}A), are reported for recovering plutonium in a PUREX process. With a phase ratio of organic to aqueous of up to 10:1, plutonium can be effectively stripped from 30 % tributyl phosphate (TBP) in kerosene into 1M HNO{sub 3} with H{sub 2}A. The complexation-reduction mechanism is illustrated with the combination of UV/Vis absorption spectra and the crystal structure of a Pu{sup IV} complex with the reagent. The fast stripping rate and the high efficiency for stripping Pu{sup IV}, through the complexation-reduction mechanism, is suitable for use in centrifugal contactors with very short contact/resident times, thereby offering significant advantages over conventional processes.

  19. Absence of gemin5 from SMN complexes in nuclear Cajal bodies

    Directory of Open Access Journals (Sweden)

    Burghes Arthur HM

    2007-07-01

    Full Text Available Abstract Background Spinal muscular atrophy is caused by reduced levels of the survival of motor neurons (SMN protein. SMN is found in large complexes with Sm proteins and at least eight other proteins, including seven "gemins". These complexes are involved in the assembly of snRNPs in the cytoplasm and their transport into the nucleus, but the precise roles of the individual protein components are largely unknown. Results We have investigated the subcellular distribution of gemins using novel antibodies against gemins 3–7, and existing mAbs against SMN, gemin2, unrip, fibrillarin and profilin II. Most gemins were equally distributed between nuclear and cytoplasmic fractions of HeLa cells, but gemin5 and unrip were more abundant in the cytoplasm. In a cytoplasmic extract obtained by mild disruption of HeLa cells, nearly all the SMN and gemins 2–4 were in large complexes, but most of the gemin5 sedimented separately with a lower S value. Most of the unrip sedimented with gemins 6 and 7 near the top of the sucrose density gradients, separate from both SMN and gemin5. Anti-SMN mAbs pulled down gemin5 from cytoplasmic extracts, but not from nuclear extracts, and gemin5 did not co-sediment with large SMN complexes in nuclear extracts. These data suggest that gemin5 is easily detached from SMN-gemin complexes in the nucleus. By immuno-histochemistry, gemin5 was rarely detectable in nuclear gems/Cajal bodies, although it was accessible to antibody and easily detectable when present. This suggests that gemin5 is normally absent from SMN complexes in these nuclear storage sites. Conclusion We conclude that SMN complexes usually exist without gemin5 in nuclear gems/Cajal bodies. Gemin5 is believed to be involved in capturing snRNA into SMN complexes in the cytoplasm for transport into the nucleus. We hypothesize that gemin5, though present in the nucleus, is no longer needed for SMN complex function during the time these complexes are stored in gems

  20. Background due to stored electrons following nuclear decays in the KATRIN spectrometers and its impact on the neutrino mass sensitivity

    CERN Document Server

    Mertens, S; Fraenkle, F M; Furse, D; Glueck, F; Goerhardt, S; Hoetzel, M; Kaefer, W; Leiber, B; Thuemmler, T; Wandkowsky, N; Wolf, J

    2012-01-01

    The KATRIN experiment is designed to measure the absolute neutrino mass scale with a sensitivity of 200 meV at 90% C.L. by high resolution tritium beta-spectroscopy. A low background level of 10 mHz at the beta-decay endpoint is required in order to achieve the design sensitivity. In this paper we discuss a novel background source arising from magnetically trapped keV electrons in electrostatic retarding spectrometers. The main sources of these electrons are alpha-decays of the radon isotopes (219,220)Rn as well as beta-decays of tritium in the volume of the spectrometers. We characterize the expected background signal by extensive MC simulations and investigate the impact on the KATRIN neutrino mass sensitivity. From these results we refine design parameters for the spectrometer vacuum system and propose active background reduction methods to meet the stringent design limits for the overall background rate.

  1. Single hepatitis-B virus core capsid binding to individual nuclear pore complexes in Hela cells.

    Science.gov (United States)

    Lill, Yoriko; Lill, Markus A; Fahrenkrog, Birthe; Schwarz-Herion, Kyrill; Paulillo, Sara; Aebi, Ueli; Hecht, Bert

    2006-10-15

    We investigate the interaction of hepatitis B virus capsids lacking a nuclear localization signal with nuclear pore complexes (NPCs) in permeabilized HeLa cells. Confocal and wide-field optical images of the nuclear envelope show well-spaced individual NPCs. Specific interactions of capsids with single NPCs are characterized by extended residence times of capsids in the focal volume which are characterized by fluorescence correlation spectroscopy. In addition, single-capsid-tracking experiments using fast wide-field fluorescence microscopy at 50 frames/s allow us to directly observe specific binding via a dual-color colocalization of capsids and NPCs. We find that binding occurs with high probability on the nuclear-pore ring moiety, at 44 +/- 9 nm radial distance from the central axis.

  2. System Theoretic Frameworks for Mitigating Risk Complexity in the Nuclear Fuel Cycle.

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Adam David; Osborn, Douglas; Jones, Katherine A; Kalinina, Elena Arkadievna; Cohn, Brian; Mohagheghi, Amir H.; DeMenno, Mercy; Thomas, Maikael A.; Parks, Mancel Jordan; Parks, Ethan Rutledge; Jeantete, Brian A

    2017-09-01

    In response to the expansion of nuclear fuel cycle (NFC) activities -- and the associated suite of risks -- around the world, this project evaluated systems-based solutions for managing such risk complexity in multimodal and multi-jurisdictional international spent nuclear fuel (SNF) transportation. By better understanding systemic risks in SNF transportation, developing SNF transportation risk assessment frameworks, and evaluating these systems-based risk assessment frameworks, this research illustrated interdependency between safety, security, and safeguards risks is inherent in NFC activities and can go unidentified when each "S" is independently evaluated. Two novel system-theoretic analysis techniques -- dynamic probabilistic risk assessment (DPRA) and system-theoretic process analysis (STPA) -- provide integrated "3S" analysis to address these interdependencies and the research results suggest a need -- and provide a way -- to reprioritize United States engagement efforts to reduce global nuclear risks. Lastly, this research identifies areas where Sandia National Laboratories can spearhead technical advances to reduce global nuclear dangers.

  3. Turning Simple Span into Complex Span: Time for Decay or Interference from Distractors?

    Science.gov (United States)

    Lewandowsky, Stephan; Geiger, Sonja M.; Morrell, Daniel B.; Oberauer, Klaus

    2010-01-01

    We investigated the effects of the duration and type of to-be-articulated distractors during encoding of a verbal list into short-term memory (STM). Distractors and to-be-remembered items alternated during list presentation, as in the complex-span task that underlies much of working-memory research. According to an interference model of STM, known…

  4. Analysis of nuclear materials by energy dispersive x-ray fluorescence and spectral effects of alpha decay

    Energy Technology Data Exchange (ETDEWEB)

    Worley, Christopher G [Los Alamos National Laboratory

    2009-01-01

    Energy dispersive X-ray fluorescence (EDXRF) spectra collected from alpha emitters are complicated by artifacts inherent to the alpha decay process, particularly when using portable instruments. For example, {sup 239}Pu EDXRF spectra exhibit a prominent uranium L X-ray emission peak series due to sample alpha decay rather than source-induced X-ray fluorescence. A portable EDXRF instrument was used to collect spectra from plutonium, americium, and a Pu-contaminated steel sample. The plutonium sample was also analyzed by wavelength dispersive XRF to demonstrate spectral differences observed when using these very different instruments.

  5. THE COMPLEX ORGANIZATION OF EUKARYOTIC CELL NUCLEUS: THE NUCLEAR BODIES (I

    Directory of Open Access Journals (Sweden)

    Cristian Campeanu

    2012-10-01

    Full Text Available Identified short time after the discovery of cells, over 300 years ago, the cell nucleus of eukaryotes continuously focused the interest of scientists, which used increasingly sophisticated research tools to clarify its complex structure and functions. The results of all these studies, especially those carried out in the second half of the past century, proved and confirmed that the eukaryotic cell nucleus is the control center of all cellular activities and also ensures the continuity of genetic information along successive generations of cells. These vital functions are the result of selective expression of genes contained in the nuclear chromatin, which is a high ordered and dynamic structure, in permanent and bilateral relations with other nuclear components. Based on these considerations, the present review aims to synthetize the latest researches and concepts about the cell nuclear territory in three distinctive parts, according to the complexity of the topic

  6. Chromatin remodeling complexes in the assembly of long noncoding RNA-dependent nuclear bodies.

    Science.gov (United States)

    Kawaguchi, Tetsuya; Hirose, Tetsuro

    2015-01-01

    Paraspeckles are subnuclear structures that assemble on nuclear paraspeckle assembly transcript 1 (NEAT1) long noncoding (lnc)RNA. Paraspeckle formation requires appropriate NEAT1 biogenesis and subsequent assembly with multiple prion-like domain (PLD) containing RNA-binding proteins. We found that SWI/SNF chromatin remodeling complexes function as paraspeckle components that interact with paraspeckle proteins (PSPs) and NEAT1. SWI/SNF complexes play an essential role in paraspeckle formation that does not require their ATP-dependent chromatin remodeling activity. Instead, SWI/SNF complexes facilitate organization of the PSP interaction network required for intact paraspeckle assembly. SWI/SNF complexes may collectively bind multiple PSPs to recruit them onto NEAT1. SWI/SNF complexes are also required for Sat III (Satellite III) lncRNA-dependent formation of nuclear stress bodies under heat shock conditions. Organization of the lncRNA-dependent omega speckle in Drosophila also depends on the chromatin remodeling complex. These findings raise the possibility that a common mechanism controls the formation of lncRNA-dependent nuclear body architecture.

  7. Design principles of nuclear receptor signaling: How complex networking improves signal transduction

    NARCIS (Netherlands)

    A.N. Kolodkin (Alexey); F.J. Bruggeman (Frank); N. Plant (Nick); M.J. Moné (Martijn); B.M. Bakker (Barbara); M.J. Campbell (Moray); J.P.T.M. van Leeuwen (Hans); C. Carlberg (Carsten); J.L. Snoep (Jacky); H.V. Westerhoff (Hans)

    2010-01-01

    textabstractThe topology of nuclear receptor (NR) signaling is captured in a systems biological graphical notation. This enables us to identify a number of design aspects of the topology of these networks that might appear unnecessarily complex or even functionally paradoxical. In realistic kinetic

  8. Design principles of nuclear receptor signaling : how complex networking improves signal transduction

    NARCIS (Netherlands)

    Kolodkin, Alexey N.; Bruggeman, Frank J.; Plant, Nick; Mone, Martijn J.; Bakker, Barbara M.; Campbell, Moray J.; van Leeuwen, Johannes P. T. M.; Carlberg, Carsten; Snoep, Jacky L.; Westerhoff, Hans V.

    2010-01-01

    The topology of nuclear receptor (NR) signaling is captured in a systems biological graphical notation. This enables us to identify a number of 'design' aspects of the topology of these networks that might appear unnecessarily complex or even functionally paradoxical. In realistic kinetic models of

  9. Design principles of nuclear receptor signaling: How complex networking improves signal transduction

    NARCIS (Netherlands)

    A.N. Kolodkin (Alexey); F.J. Bruggeman (Frank); N. Plant (Nick); M.J. Moné (Martijn); B.M. Bakker (Barbara); M.J. Campbell (Moray); J.P.T.M. van Leeuwen (Hans); C. Carlberg (Carsten); J.L. Snoep (Jacky); H.V. Westerhoff (Hans)

    2010-01-01

    textabstractThe topology of nuclear receptor (NR) signaling is captured in a systems biological graphical notation. This enables us to identify a number of design aspects of the topology of these networks that might appear unnecessarily complex or even functionally paradoxical. In realistic kinetic

  10. Dissecting mechanisms of nuclear mRNA surveillance in THO/sub2 complex mutants

    DEFF Research Database (Denmark)

    Rougemaille, Mathieu; Gudipati, Rajani K; Olesen, Jens Raabjerg

    2007-01-01

    The nuclear exosome is involved in numerous RNA metabolic processes. Exosome degradation of rRNA, snoRNA, snRNA and tRNA in Saccharomyces cerevisiae is activated by TRAMP complexes, containing either the Trf4p or Trf5p poly(A) polymerase. These enzymes are presumed to facilitate exosome access...

  11. Structure, dynamics, evolution, and function of a major scaffold component in the nuclear pore complex.

    Science.gov (United States)

    Sampathkumar, Parthasarathy; Kim, Seung Joong; Upla, Paula; Rice, William J; Phillips, Jeremy; Timney, Benjamin L; Pieper, Ursula; Bonanno, Jeffrey B; Fernandez-Martinez, Javier; Hakhverdyan, Zhanna; Ketaren, Natalia E; Matsui, Tsutomu; Weiss, Thomas M; Stokes, David L; Sauder, J Michael; Burley, Stephen K; Sali, Andrej; Rout, Michael P; Almo, Steven C

    2013-04-02

    The nuclear pore complex, composed of proteins termed nucleoporins (Nups), is responsible for nucleocytoplasmic transport in eukaryotes. Nuclear pore complexes (NPCs) form an annular structure composed of the nuclear ring, cytoplasmic ring, a membrane ring, and two inner rings. Nup192 is a major component of the NPC's inner ring. We report the crystal structure of Saccharomyces cerevisiae Nup192 residues 2-960 [ScNup192(2-960)], which adopts an α-helical fold with three domains (i.e., D1, D2, and D3). Small angle X-ray scattering and electron microscopy (EM) studies reveal that ScNup192(2-960) could undergo long-range transition between "open" and "closed" conformations. We obtained a structural model of full-length ScNup192 based on EM, the structure of ScNup192(2-960), and homology modeling. Evolutionary analyses using the ScNup192(2-960) structure suggest that NPCs and vesicle-coating complexes are descended from a common membrane-coating ancestral complex. We show that suppression of Nup192 expression leads to compromised nuclear transport and hypothesize a role for Nup192 in modulating the permeability of the NPC central channel.

  12. Proliferation concerns in the Russian closed nuclear weapons complex cities : a study of regional migration behavior.

    Energy Technology Data Exchange (ETDEWEB)

    Flores, Kristen Lee

    2004-07-01

    The collapse of the Soviet Union in 1991 left the legacy of the USSR weapons complex with an estimated 50 nuclear, chemical, and biological weapons cities containing facilities responsible for research, production, maintenance, and destruction of the weapons stockpile. The Russian Federation acquired ten such previously secret, closed nuclear weapons complex cities. Unfortunately, a lack of government funding to support these facilities resulted in non-payment of salaries to employees and even plant closures, which led to an international fear of weapons material and knowledge proliferation. This dissertation analyzes migration in 33 regions of the Russian Federation, six of which contain the ten closed nuclear weapons complex cities. This study finds that the presence of a closed nuclear city does not significantly influence migration. However, the factors that do influence migration are statistically different in regions containing closed nuclear cities compared to regions without closed nuclear cities. Further, these results show that the net rate of migration has changed across the years since the break up of the Soviet Union, and that the push and pull factors for migration have changed across time. Specifically, personal and residential factors had a significant impact on migration immediately following the collapse of the Soviet Union, but economic infrastructure and societal factors became significant in later years. Two significant policy conclusions are derived from this research. First, higher levels of income are found to increase outmigration from regions, implying that programs designed to prevent migration by increasing incomes for closed city residents may be counter-productive. Second, this study finds that programs designed to increase capital and build infrastructure in the new Russian Federation will be more effective for employing scientists and engineers from the weapons complex, and consequently reduce the potential for emigration of

  13. Werner complex deficiency in cells disrupts the Nuclear Pore Complex and the distribution of lamin B1.

    Science.gov (United States)

    Li, Zhi; Zhu, Yizhou; Zhai, Yujia; R Castroagudin, Michelle; Bao, Yifei; White, Tommy E; Glavy, Joseph S

    2013-12-01

    From the surrounding shell to the inner machinery, nuclear proteins provide the functional plasticity of the nucleus. This study highlights the nuclear association of Pore membrane (POM) protein NDC1 and Werner protein (WRN), a RecQ helicase responsible for the DNA instability progeria disorder, Werner Syndrome. In our previous publication, we connected the DNA damage sensor Werner's Helicase Interacting Protein (WHIP), a binding partner of WRN, to the NPC. Here, we confirm the association of the WRN/WHIP complex and NDC1. In established WRN/WHIP knockout cell lines, we further demonstrate the interdependence of WRN/WHIP and Nucleoporins (Nups). These changes do not completely abrogate the barrier of the Nuclear Envelope (NE) but do affect the distribution of FG Nups and the RAN gradient, which are necessary for nuclear transport. Evidence from WRN/WHIP knockout cell lines demonstrates changes in the processing and nucleolar localization of lamin B1. The appearance of "RAN holes" void of RAN corresponds to regions within the nucleolus filled with condensed pools of lamin B1. From WRN/WHIP knockout cell line extracts, we found three forms of lamin B1 that correspond to mature holoprotein and two potential post-translationally modified forms of the protein. Upon treatment with topoisomerase inhibitors lamin B1 cleavage occurs only in WRN/WHIP knockout cells. Our data suggest the link of the NDC1 and WRN as one facet of the network between the nuclear periphery and genome stability. Loss of WRN complex leads to multiple alterations at the NPC and the nucleolus.

  14. Chemical Partition of the Radiative Decay Rate of Luminescence of Europium Complexes

    Science.gov (United States)

    Lima, Nathalia B. D.; Dutra, José Diogo L.; Gonçalves, Simone M. C.; Freire, Ricardo O.; Simas, Alfredo M.

    2016-02-01

    The spontaneous emission coefficient, Arad, a global molecular property, is one of the most important quantities related to the luminescence of complexes of lanthanide ions. In this work, by suitable algebraic transformations of the matrices involved, we introduce a partition that allows us to compute, for the first time, the individual effects of each ligand on Arad, a property of the molecule as a whole. Such a chemical partition thus opens possibilities for the comprehension of the role of each of the ligands and their interactions on the luminescence of europium coordination compounds. As an example, we applied the chemical partition to the case of repeating non-ionic ligand ternary complexes of europium(III) with DBM, TTA, and BTFA, showing that it allowed us to correctly order, in an a priori manner, the non-obvious pair combinations of non-ionic ligands that led to mixed-ligand compounds with larger values of Arad.

  15. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Kai Zuber

    2012-10-01

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  16. Natural disease course and genotype-phenotype correlations in Complex I deficiency caused by nuclear gene defects

    DEFF Research Database (Denmark)

    Koene, S; Rodenburg, R J; van der Knaap, M S;

    2012-01-01

    Mitochondrial complex I is the largest multi-protein enzyme complex of the oxidative phosphorylation system. Seven subunits of this complex are encoded by the mitochondrial and the remainder by the nuclear genome. We review the natural disease course and signs and symptoms of 130 patients (four new...... cases and 126 from literature) with mutations in nuclear genes encoding structural complex I proteins or those involved in its assembly. Complex I deficiency caused by a nuclear gene defect is usually a non-dysmorphic syndrome, characterized by severe multi-system organ involvement and a poor prognosis...

  17. On the trade-off between complexity and correlation decay in structural learning algorithms

    CERN Document Server

    Bento, José

    2011-01-01

    We consider the problem of learning the structure of Ising models (pairwise binary Markov random fields) from i.i.d. samples. While several methods have been proposed to accomplish this task, their relative merits and limitations remain somewhat obscure. By analyzing a number of concrete examples, we show that low-complexity algorithms often fail when the Markov random field develops long-range correlations. More precisely, this phenomenon appears to be related to the Ising model phase transition (although it does not coincide with it).

  18. Nuclear export signal-interacting protein forms complexes with lamin A/C-Nups to mediate the CRM1-independent nuclear export of large hepatitis delta antigen.

    Science.gov (United States)

    Huang, Cheng; Jiang, Jia-Yin; Chang, Shin C; Tsay, Yeou-Guang; Chen, Mei-Ru; Chang, Ming-Fu

    2013-02-01

    Nuclear export is an important process that not only regulates the functions of cellular factors but also facilitates the assembly of viral nucleoprotein complexes. Chromosome region maintenance 1 (CRM1) that mediates the transport of proteins bearing the classical leucine-rich nuclear export signal (NES) is the best-characterized nuclear export receptor. Recently, several CRM1-independent nuclear export pathways were also identified. The nuclear export of the large form of hepatitis delta antigen (HDAg-L), a nucleocapsid protein of hepatitis delta virus (HDV), which contains a CRM1-independent proline-rich NES, is mediated by the host NES-interacting protein (NESI). The mechanism of the NESI protein in mediating nuclear export is still unknown. In this study, NESI was characterized as a highly glycosylated membrane protein. It interacted and colocalized well in the nuclear envelope with lamin A/C and nucleoporins. Importantly, HDAg-L could be coimmunoprecipitated with lamin A/C and nucleoporins. In addition, binding of the cargo HDAg-L to the C terminus of NESI was detected for the wild-type protein but not for the nuclear export-defective HDAg-L carrying a P205A mutation [HDAg-L(P205A)]. Knockdown of lamin A/C effectively reduced the nuclear export of HDAg-L and the assembly of HDV. These data indicate that by forming complexes with lamin A/C and nucleoporins, NESI facilitates the CRM1-independent nuclear export of HDAg-L.

  19. The DNA damage response at eroded telomeres and tethering to the nuclear pore complex

    DEFF Research Database (Denmark)

    Khadaroo, Basheer; Teixeira, M Teresa; Luciano, Pierre;

    2009-01-01

    The ends of linear eukaryotic chromosomes are protected by telomeres, which serve to ensure proper chromosome replication and to prevent spurious recombination at chromosome ends. In this study, we show by single cell analysis that in the absence of telomerase, a single short telomere is sufficient...... protein Rad52 into a single focus. Moreover, we show that eroded telomeres, although remaining at the nuclear periphery, move to the nuclear pore complex. Our results link the DNA damage response at eroded telomeres to changes in subnuclear localization and suggest the existence of collapsed replication...

  20. Existence and decay estimates of solutions to complex Ginzburg-Landau type equations

    Science.gov (United States)

    Shimotsuma, Daisuke; Yokota, Tomomi; Yoshii, Kentarou

    2016-02-01

    This paper deals with the initial-boundary value problem (denoted by (CGL)) for the complex Ginzburg-Landau type equation ∂u/∂t - (λ + iα) Δu + (κ + iβ)| u | q - 1 u - γu = 0 with initial data u0 ∈Lp (Ω) in the case 1 0, α , β , γ , κ ∈ R. There are a lot of studies on local and global existence of solutions to (CGL) including the physically relevant case q = 3 and κ > 0. This paper gives existence results with precise properties of solutions and rigorous proof from a mathematical point of view. The physically relevant case can be considered as a special case of the results. Moreover, in the case κ inequality with Re .

  1. Effect of a triaxial nuclear shape on proton tunneling : the decay and structure of {sup 145}Tm.

    Energy Technology Data Exchange (ETDEWEB)

    Seweryniak, D.; Blank, B.; Carpenter, M. P.; Davids, C. N.; Davinson, T.; Freeman, S. J.; Hammond, N.; Hoteling, N.; Janssens, R. V. F.; Khoo, T. L.; Liu, Z.; Mukherjee, G.; Robinson, A.; Scholey, C.; Sinha, S.; Shergur, J.; Starosta, K.; Walters, W. B.; Woehr, A.; Woods, P. J.; Physics; Centre d' Etudes Nucleaires de Bordeaux-Gradignan; Univ. of Edinburgh; Univ. of Manchester; Univ. of Maryland; Univ. of Jyvaskyla; Michigan State Univ.; Univ. of Notre Dame

    2007-08-24

    Gamma rays deexciting states in the proton emitter {sup 145}Tm were observed using the recoil-decay tagging method. The {sup 145}Tm ground-state rotational band was found to exhibit the properties expected for an h{sub 11/2} proton decoupled band. In addition, coincidences between protons feeding the 2{sup +} state in {sup 144}Er and the 2{sup +} {yields} 0{sup +} {gamma}-ray transition were detected the first measurement of this kind, leading to a more precise value for the 2+ excitation energy of 329(1) keV. Calculations with the particle-rotor model and the core quasiparticle coupling model indicate that the properties of the {pi}h{sub 11/2} band and the proton-decay rates in {sup 145}Tm are consistent with the presence of triaxiality with an asymmetry parameter {gamma} {approx} 20 degrees.

  2. NUCLEAR AND HEAVY ION PHYSICS: α-decay half-lives of superheavy nuclei and general predictions

    Science.gov (United States)

    Dong, Jian-Min; Zhang, Hong-Fei; Wang, Yan-Zhao; Zuo, Wei; Su, Xin-Ning; Li, Jun-Qing

    2009-08-01

    The generalized liquid drop model (GLDM) and the cluster model have been employed to calculate the α-decay half-lives of superheavy nuclei (SHN) using the experimental α-decay Q values. The results of the cluster model are slightly poorer than those from the GLDM if experimental Q values are used. The prediction powers of these two models with theoretical Q values from Audi et al. (QAudi) and Muntian et al. (QM) have been tested to find that the cluster model with QAudi and QM could provide reliable results for Z > 112 but the GLDM with QAudi for Z <= 112. The half-lives of some still unknown nuclei are predicted by these two models and these results may be useful for future experimental assignment and identification.

  3. Material composition and nuclear data libraries' influence on nickel-chromium alloys activation evaluation: a comparison with decay heat experiments

    CERN Document Server

    Cepraga, D G

    2000-01-01

    The paper presents the activation analyses on Inconel-600 nickel-chromium alloy. Three activation data libraries, namely the EAF-4.1, the EAF-97 and the FENDL/A-2, and the FENDL/D-2 decay data library, have been used to perform the calculation with the European activation code ANITA-4/M. The neutron flux distribution into the material samples was provided by JAERI as results of 3D Monte-Carlo MCNP transport code experiment simulation. A comparison with integral decay heat measurement performed at the Fusion Neutronics Source (FNS), JAERI, Tokai, Japan, is used to validate the computational approach. The calculation results are given and discussed. The impact of the material composition, including impurities, on the decay heat of samples irradiated in fusion-like neutron spectra is assessed and discussed. The discrepancies calculations-experiments are within the experimental errors, that is between 6% and 10%, except for the short cooling times (less than 40 min after the end of irradiation). To improve calcul...

  4. Novel Nuclear Protein Complexes of Dystrophin 71 Isoforms in Rat Cultured Hippocampal GABAergic and Glutamatergic Neurons.

    Directory of Open Access Journals (Sweden)

    Rafael Rodríguez-Muñoz

    Full Text Available The precise functional role of the dystrophin 71 in neurons is still elusive. Previously, we reported that dystrophin 71d and dystrophin 71f are present in nuclei from cultured neurons. In the present work, we performed a detailed analysis of the intranuclear distribution of dystrophin 71 isoforms (Dp71d and Dp71f, during the temporal course of 7-day postnatal rats hippocampal neurons culture for 1h, 2, 4, 10, 15 and 21 days in vitro (DIV. By immunofluorescence assays, we detected the highest level of nuclear expression of both dystrophin Dp71 isoforms at 10 DIV, during the temporal course of primary culture. Dp71d and Dp71f were detected mainly in bipolar GABAergic (≥60% and multipolar Glutamatergic (≤40% neurons, respectively. We also characterized the existence of two nuclear dystrophin-associated protein complexes (DAPC: dystrophin 71d or dystrophin 71f bound to β-dystroglycan, α1-, β-, α2-dystrobrevins, α-syntrophin, and syntrophin-associated protein nNOS (Dp71d-DAPC or Dp71f-DAPC, respectively, in the hippocampal neurons. Furthermore, both complexes were localized in interchromatin granule cluster structures (nuclear speckles of neuronal nucleoskeleton preparations. The present study evinces that each Dp71's complexes differ slightly in dystrobrevins composition. The results demonstrated that Dp71d-DAPC was mainly localized in bipolar GABAergic and Dp71f-DAPC in multipolar Glutamatergic hippocampal neurons. Taken together, our results show that dystrophin 71d, dystrophin 71f and DAP integrate protein complexes, and both complexes were associated to nuclear speckles structures.

  5. Novel Nuclear Protein Complexes of Dystrophin 71 Isoforms in Rat Cultured Hippocampal GABAergic and Glutamatergic Neurons.

    Science.gov (United States)

    Rodríguez-Muñoz, Rafael; Cárdenas-Aguayo, María Del Carmen; Alemán, Víctor; Osorio, Beatriz; Chávez-González, Oscar; Rendon, Alvaro; Martínez-Rojas, Dalila; Meraz-Ríos, Marco Antonio

    2015-01-01

    The precise functional role of the dystrophin 71 in neurons is still elusive. Previously, we reported that dystrophin 71d and dystrophin 71f are present in nuclei from cultured neurons. In the present work, we performed a detailed analysis of the intranuclear distribution of dystrophin 71 isoforms (Dp71d and Dp71f), during the temporal course of 7-day postnatal rats hippocampal neurons culture for 1h, 2, 4, 10, 15 and 21 days in vitro (DIV). By immunofluorescence assays, we detected the highest level of nuclear expression of both dystrophin Dp71 isoforms at 10 DIV, during the temporal course of primary culture. Dp71d and Dp71f were detected mainly in bipolar GABAergic (≥60%) and multipolar Glutamatergic (≤40%) neurons, respectively. We also characterized the existence of two nuclear dystrophin-associated protein complexes (DAPC): dystrophin 71d or dystrophin 71f bound to β-dystroglycan, α1-, β-, α2-dystrobrevins, α-syntrophin, and syntrophin-associated protein nNOS (Dp71d-DAPC or Dp71f-DAPC, respectively), in the hippocampal neurons. Furthermore, both complexes were localized in interchromatin granule cluster structures (nuclear speckles) of neuronal nucleoskeleton preparations. The present study evinces that each Dp71's complexes differ slightly in dystrobrevins composition. The results demonstrated that Dp71d-DAPC was mainly localized in bipolar GABAergic and Dp71f-DAPC in multipolar Glutamatergic hippocampal neurons. Taken together, our results show that dystrophin 71d, dystrophin 71f and DAP integrate protein complexes, and both complexes were associated to nuclear speckles structures.

  6. Prioritization methodology for the decommissioning of nuclear facilities: a study case on the Iraq former nuclear complex.

    Science.gov (United States)

    Jarjies, Adnan; Abbas, Mohammed; Monken Fernandes, Horst; Wong, Melanie; Coates, Roger

    2013-05-01

    There are a number of sites in Iraq which have been used for nuclear activities and which contain potentially significant amounts of radioactive waste. The principal nuclear site being Al-Tuwaitha. Many of these sites suffered substantial physical damage during the Gulf Wars and have been subjected to subsequent looting. All require decommissioning in order to ensure both radiological and non-radiological safety. However, it is not possible to undertake the decommissioning of all sites and facilities at the same time. Therefore, a prioritization methodology has been developed in order to aid the decision-making process. The methodology comprises three principal stages of assessment: i) a quantitative surrogate risk assessment ii) a range of sensitivity analyses and iii) the inclusion of qualitative modifying factors. A group of Tuwaitha facilities presented the highest risk among the evaluated ones, followed by a middle ranking grouping of Tuwaitha facilities and some other sites, and a relatively large group of lower risk facilities and sites. The initial order of priority is changed when modifying factors are taken into account. It has to be considered the Iraq's isolation from the international nuclear community over the last two decades and the lack of experienced personnel. Therefore it is appropriate to initiate decommissioning operations on selected low risk facilities at Tuwaitha in order to build capacity and prepare for work to be carried out in more complex and potentially high hazard facilities. In addition it is appropriate to initiate some prudent precautionary actions relating to some of the higher risk facilities. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Isotactic rac-Lactide Polymerization with Copper Complexes: The Influence of Complex Nuclearity.

    Science.gov (United States)

    Fortun, Solène; Daneshmand, Pargol; Schaper, Frank

    2015-11-09

    Diiminopyrrolide copper alkoxide complexes, LCuOR (OR(1)=N,N-dimethylamino ethoxide, OR(2)=2-pyridyl methoxide), are active for the polymerization of rac-lactide at ambient temperature in benzene to yield polymers with M(w)/M(n)=1.0-1.2. X-ray diffraction studies showed bridged dinuclear complexes in the solid state for both complexes. While LCuOR(1) provided only atactic polylactide, LCuOR(2) produced partially isotactic polylactide (P(m)=0.7). The difference in stereocontrol is attributed to a dinuclear active species for LCuOR(2) in contrast to a mononuclear species for LCuOR(1).

  8. AFM visualization of sub-50nm polyplex disposition to the nuclear pore complex without compromising the integrity of the nuclear envelope.

    Science.gov (United States)

    Andersen, Helene; Parhamifar, Ladan; Hunter, A Christy; Shahin, Victor; Moghimi, S Moein

    2016-12-28

    It has been questioned as to whether polyplexes in the cytoplasm can reach the nuclear compartment and if so in what form. By applying atomic force microscopy (AFM) to the nuclear envelope and the nuclear pore complexes, we demonstrate that disposition of polyethylenimine (PEI)/DNA polyplexes that were microinjected into the oocytes of Xenopus laevis, as an example of a non-dividing cell, is exclusive to the nuclear pore complex (NPC). AFM images show NPCs clogged only with sub-50nm polyplexes. This mode of disposition neither altered the morphology/integrity of the nuclear membrane nor the NPC. AFM images further show polyplexes on the nucleoplasmic side of the envelope, presumably indicating species in transit. Transmission electron microscopy studies of ruptured nuclei from transfected human cell lines demonstrate the presence of sub-50nm particles resembling polyplexes in morphology compared with control preparations.

  9. A systematic method for identifying vital areas at complex nuclear facilities.

    Energy Technology Data Exchange (ETDEWEB)

    Beck, David Franklin; Hockert, John

    2005-05-01

    Identifying the areas to be protected is an important part of the development of measures for physical protection against sabotage at complex nuclear facilities. In June 1999, the International Atomic Energy Agency published INFCIRC/225/Rev.4, 'The Physical Protection of Nuclear Material and Nuclear Facilities.' This guidance recommends that 'Safety specialists, in close cooperation with physical protection specialists, should evaluate the consequences of malevolent acts, considered in the context of the State's design basis threat, to identify nuclear material, or the minimum complement of equipment, systems or devices to be protected against sabotage.' This report presents a structured, transparent approach for identifying the areas that contain this minimum complement of equipment, systems, and devices to be protected against sabotage that is applicable to complex nuclear facilities. The method builds upon safety analyses to develop sabotage fault trees that reflect sabotage scenarios that could cause unacceptable radiological consequences. The sabotage actions represented in the fault trees are linked to the areas from which they can be accomplished. The fault tree is then transformed (by negation) into its dual, the protection location tree, which reflects the sabotage actions that must be prevented in order to prevent unacceptable radiological consequences. The minimum path sets of this fault tree dual yield, through the area linkage, sets of areas, each of which contains nuclear material, or a minimum complement of equipment, systems or devices that, if protected, will prevent sabotage. This method also provides guidance for the selection of the minimum path set that permits optimization of the trade-offs among physical protection effectiveness, safety impact, cost and operational impact.

  10. Three-Dimensional Mapping of mRNA Export through the Nuclear Pore Complex

    Directory of Open Access Journals (Sweden)

    Steven J. Schnell

    2014-11-01

    Full Text Available The locations of transcription and translation of mRNA in eukaryotic cells are spatially separated by the nuclear envelope (NE. Plenty of nuclear pore complexes (NPCs embedded in the NE function as the major gateway for the export of transcribed mRNAs from the nucleus to the cytoplasm. Whereas the NPC, perhaps one of the largest protein complexes, provides a relatively large channel for macromolecules to selectively pass through it in inherently three-dimensional (3D movements, this channel is nonetheless below the diffraction limit of conventional light microscopy. A full understanding of the mRNA export mechanism urgently requires real-time mapping of the 3D dynamics of mRNA in the NPC of live cells with innovative imaging techniques breaking the diffraction limit of conventional light microscopy. Recently, super-resolution fluorescence microscopy and single-particle tracking (SPT techniques have been applied to the study of nuclear export of mRNA in live cells. In this review, we emphasize the necessity of 3D mapping techniques in the study of mRNA export, briefly summarize the feasibility of current 3D imaging approaches, and highlight the new features of mRNA nuclear export elucidated with a newly developed 3D imaging approach combining SPT-based super-resolution imaging and 2D-to-3D deconvolution algorithms.

  11. A-type Lamins Form Distinct Filamentous Networks with Differential Nuclear Pore Complex Associations.

    Science.gov (United States)

    Xie, Wei; Chojnowski, Alexandre; Boudier, Thomas; Lim, John S Y; Ahmed, Sohail; Ser, Zheng; Stewart, Colin; Burke, Brian

    2016-10-10

    The nuclear lamina is a universal feature of metazoan nuclear envelopes (NEs) [1]. In mammalian cells, it appears as a 10-30 nm filamentous layer at the nuclear face of the inner nuclear membrane (INM) and is composed primarily of A- and B-type lamins, members of the intermediate filament family [2]. While providing structural integrity to the NE, the lamina also represents an important signaling and regulatory platform [3]. Two A-type lamin isoforms, lamins A and C (LaA and LaC), are expressed in most adult human cells. Encoded by a single gene, these proteins are largely identical, diverging only in their C-terminal tail domains. By contrast with that of LaC, the unique LaA tail undergoes extensive processing, including farnesylation and endo-proteolysis [4, 5]. However, functional differences between LaA and LaC are still unclear. Compounding this uncertainty, the structure of the lamina remains ill defined. In this study, we used BioID, an in vivo proximity-labeling method to identify differential interactors of A-type lamins [6]. One of these, Tpr, a nuclear pore complex (NPC) protein, is highlighted by its selective association with LaC. By employing superresolution microscopy, we demonstrate that this Tpr association is mirrored in enhanced interaction of LaC with NPCs. Further superresolution studies visualizing both endogenous A- and B-type lamins have allowed us to construct a nanometer-scale model of the mammalian nuclear lamina. Our data indicate that different A- and B-type lamin species assemble into separate filament networks that together form an extended composite structure at the nuclear periphery providing attachment sites for NPCs, thereby regulating their distribution.

  12. Effect of tert-Butyl Functionalization on the Photoexcited Decay of a Fe(II)-N-Heterocyclic Carbene Complex

    DEFF Research Database (Denmark)

    Pápai, Mátyás Imre; Penfold, Thomas J.; Møller, Klaus Braagaard

    2016-01-01

    Understanding and subsequently being able to manipulate the excited-state decay pathways of functional transition-metal complexes is of utmost importance in order to solve grand challenges in solar energy conversion and data storage. Herein, we perform quantum chemical calculations and spin......)pyridine), completely alters the excited-state relaxation. Ultrafast deactivation of the initially excited metal-to-ligand charge transfer (1,3MLCT) states occurs within 350 fs. In contrast to the widely adopted mechanism of Fe(II) photophysics, these states decay into close-lying singlet metal-centered (1MC) states...

  13. Application of Nuclear Microprobes towards Understanding Complex Ore Geo-electrochemistry

    Directory of Open Access Journals (Sweden)

    Szymanski R.

    2012-10-01

    Full Text Available We report on recent development on the CSIRO Nuclear Microprobe (NMP towards catering for long exposure mapping required for large area scanning. A new data collection system based on Labview FPGA highly co-ordinated with beam transport sits at the heart of the upgrade. These upgrades are discussed and an example of the systems use for μ-Particle Induced X-ray Emission (PIXE analysis in the area of complex ore geo-electrochemistry is briefly described.

  14. Hardware and Software Complexes for Automatic Position Pipe Welding at Nuclear Power Plants

    Directory of Open Access Journals (Sweden)

    N.M. Makhlin

    2013-11-01

    Full Text Available Achievements of the E.O. Paton Electric Welding Institute in development of domestic samples of equipment with elements of adaptive control for automatic position pipe welding during assembly and repair of power units of nuclear and heat power electric stations, in shipbuilding and chemical engineering, at enterprises of oil-and-gas complex and in other branches of industry are presented.

  15. Nuclear cascades in Saturn's rings - Cosmic ray albedo neutron decay and origins of trapped protons in the inner magnetosphere

    Science.gov (United States)

    Cooper, J. F.

    1983-01-01

    The nearly equatorial trajectory of the Pioneer 11 spacecraft through Saturn's high energy proton radiation belts and under the main A-B-C rings provided a unique opportunity to study the radial dependence of the greater than 30 MeV proton intensities in the belts in terms of models for secondary nucleon production by cosmic ray interactions in the rings, in situ proton injection in the radiation belts by neutron beta decay, magnetospheric diffusion, and absorption by planetary rings and satellites. Maximum trapped proton intensities measured by Pioneer 11 in the radiation belts are compared with calculated intensities and found consistent with trapping times of roughly 40 years and a radial diffusion coefficient of about 10 to the -15th L to the 9th R sub s squared/s. Differential energy spectra proportional to E to the -2 estimated from integral measurements of trapped photons with E greater than 100 MeV are consistent with the beta decay model, but an inferred turndown of the spectra toward lower energies and reported integral proton anisotropies of a specified form both indicate the need for more realistic calculations of the neutron source from the rings and the radiation belt loss processes.

  16. Comparative Analysis of Brookhaven National Laboratory Nuclear Decay Data and Super-Kamiokande Neutrino Data: Indication of a Solar Connection

    CERN Document Server

    Sturrock, P A

    2015-01-01

    An experiment carried out at the Brookhaven National Laboratory from February 1982 to December 1989 acquired 364 measurements of the beta-decay rates of a sample of 36Cl and of a sample of 32Si. The experimenters reported finding small periodic annual deviations of the data points from an exponential decay - of uncertain origin. We here analyze this dataset by power spectrum analysis and by forming spectrograms and phasegrams. We confirm the occurrence of annual oscillations but we also find evidence of oscillations in a band of frequencies appropriate for the internal rotation of the Sun. Both datasets show clear evidence of a transient oscillation with a frequency of 12.7 cycles per year that falls in the range of rotational frequencies for the solar radiative zone. We repeat these analyses for 358 neutrino measurements acquired by Super-Kamiokande over the interval May 1986 to August 2001. Spectrogram analysis yields a strong and steady oscillation at about 9.5 cycles per year and an intermittent oscillati...

  17. Yeast silencing factor Sir4 and a subset of nucleoporins form a complex distinct from nuclear pore complexes.

    Science.gov (United States)

    Lapetina, Diego L; Ptak, Christopher; Roesner, Ulyss K; Wozniak, Richard W

    2017-09-07

    Interactions occurring at the nuclear envelope (NE)-chromatin interface influence both NE structure and chromatin organization. Insights into the functions of NE-chromatin interactions have come from the study of yeast subtelomeric chromatin and its association with the NE, including the identification of various proteins necessary for tethering subtelomeric chromatin to the NE and the silencing of resident genes. Here we show that four of these proteins-the silencing factor Sir4, NE-associated Esc1, the SUMO E3 ligase Siz2, and the nuclear pore complex (NPC) protein Nup170-physically and functionally interact with one another and a subset of NPC components (nucleoporins or Nups). Importantly, this group of Nups is largely restricted to members of the inner and outer NPC rings, but it lacks numerous others including cytoplasmically and nucleoplasmically positioned Nups. We propose that this Sir4-associated Nup complex is distinct from holo-NPCs and that it plays a role in subtelomeric chromatin organization and NE tethering. © 2017 Lapetina et al.

  18. DINUCLEAR COMPLEXES AS BUILDING BLOCKS FOR TETRA-NUCLEAR MACROCYCLIC COMPLEXES WITH DITHIOLATE MACROCYCLIC LIGAND

    Directory of Open Access Journals (Sweden)

    V. Lozan

    2013-06-01

    Full Text Available A series of novel tri-, tetra- and pentanuclear complexes composed of dinuclear LM units (M=Co, Ni, Zn; L=24-membered macrocyclic hexaaza-dithiophenolate ligand and ferrocenecarboxylate ([CpFeC5H4CO2]ˉ, 1,1’-ferrocenedicarboxy-late ([Fe(C5H4-CO22]2ˉ, acetylene-dicarboxylate, terephthalate, isophthalate, and naphthalene diimide dicarboxylate groups is reported. The complexes, have been synthesized and characterised by UV/Vis-, IR-, NMR-spectroscopy, Cyclovoltammetry, and X-ray crystallography. Each dicarboxylate dianion acts as a quadridentate bridging ligand linking two bioctahedral LM2 units via µ1,3-bridging carboxylate functions to generate discrete dications with a central LM2(O2C-R-CO2M2L core. The magnetic properties of these compounds reveal the presence of weak ferromagnetic exchange interactions between the NiII ions of the dinuclear subunits and negligible coupling across the dicarboxylate bridges.

  19. Nuclear DAMP complex-mediated RAGE-dependent macrophage cell death

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ruochan [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Department of Infectious Diseases and State Key Lab of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China); Fu, Sha; Fan, Xue-Gong [Department of Infectious Diseases and State Key Lab of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China); Lotze, Michael T.; Zeh, Herbert J. [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Tang, Daolin, E-mail: tangd2@upmc.edu [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Kang, Rui, E-mail: kangr@upmc.edu [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213 (United States)

    2015-03-13

    High mobility group box 1 (HMGB1), histone, and DNA are essential nuclear components involved in the regulation of chromosome structure and function. In addition to their nuclear function, these molecules act as damage-associated molecular patterns (DAMPs) alone or together when released extracellularly. The synergistic effect of these nuclear DNA-HMGB1-histone complexes as DAMP complexes (nDCs) on immune cells remains largely unexplored. Here, we demonstrate that nDCs limit survival of macrophages (e.g., RAW264.7 and peritoneal macrophages) but not cancer cells (e.g., HCT116, HepG2 and Hepa1-6). nDCs promote production of inflammatory tumor necrosis factor α (TNFα) release, triggering reactive oxygen species-dependent apoptosis and necrosis. Moreover, the receptor for advanced glycation end products (RAGE), but not toll-like receptor (TLR)-4 and TLR-2, was required for Akt-dependent TNFα release and subsequent cell death following treatment with nDCs. Genetic depletion of RAGE by RNAi, antioxidant N-Acetyl-L-cysteine, and TNFα neutralizing antibody significantly attenuated nDC-induced cell death. These findings provide evidence supporting novel signaling mechanisms linking nDCs and inflammation in macrophage cell death. - Highlights: • Nuclear DAMP complexes (nDCs) selectively induce cell death in macrophages, but not cancer cells. • TNFα-mediated oxidative stress is required for nDC-induced death. • RAGE-mediated Akt activation is required for nDC-induced TNFα release. • Blocking RAGE and TNFα inhibits nDC-induced macrophage cell death.

  20. Nuclear structure of229Th from γ-ray spectroscopy study of233U α-particle decay

    Science.gov (United States)

    Barci, V.; Ardisson, G.; Barci-Funel, G.; Weiss, B.; El Samad, O.; Sheline, R. K.

    2003-09-01

    The level structure of 229Th, produced by α-particle decay of 233U, was studied with γ-ray spectroscopy measurements. The sources were continuously separated from daughters with ion-exchange chromatographic methods. Singles and coincidence measurements were performed with high-purity germanium detectors. Energies and intensities of about 220 γ rays were accurately determined. About 70 transitions were reported for the first time, especially in the 300 700 keV energy range. A 229Th level scheme was proposed, accounting for 220 transitions among 47 excited states. Alpha-particle feeding intensities and hindrance factors were deduced and compared to direct α-particle measurements; the agreement was found to be relatively good. The level structure was interpreted in the framework of rotational and/or reflection asymmetric models. The agreement with experimental data was shown to be satisfactory.

  1. Glutarimidedioxime: a complexing and reducing reagent for plutonium recovery from spent nuclear fuel reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Xian, Liang [Radiochemistry Department, China Institute of Atomic Energy, Beijing (China); Tian, Guoxin [Radiochemistry Department, China Institute of Atomic Energy, Beijing (China); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Beavers, Christine M.; Teat, Simon J. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Shuh, David K. [Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

    2016-04-04

    Efficient separation processes for recovering uranium and plutonium from spent nuclear fuel are essential to the development of advanced nuclear fuel cycles. The performance characteristics of a new salt-free complexing and reducing reagent, glutarimidedioxime (H{sub 2}A), are reported for recovering plutonium in a PUREX process. With a phase ratio of organic to aqueous of up to 10:1, plutonium can be effectively stripped from 30 % tributyl phosphate (TBP) in kerosene into 1 m HNO{sub 3} with H{sub 2}A. The complexation-reduction mechanism is illustrated with the combination of UV/Vis absorption spectra and the crystal structure of a Pu{sup IV} complex with the reagent. The fast stripping rate and the high efficiency for stripping Pu{sup IV}, through the complexation-reduction mechanism, is suitable for use in centrifugal contactors with very short contact/resident times, thereby offering significant advantages over conventional processes. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Measurements of observables in the pion-nucleon system, nuclear a- dependence of heavy quark production and rare decays of D and B mesons. Progress report, 1 December, 1990--15 February, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Sadler, M.E.; Isenhower, L.D.

    1992-02-15

    This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments. (LSP)

  3. Significant prognostic values of nuclear genes encoding mitochondrial complex I subunits in tumor patients.

    Science.gov (United States)

    Li, L D; Sun, H F; Bai, Y; Gao, S P; Jiang, H L; Jin, W

    2016-01-01

    In cancer biology, it remains still open question concerning the oncogenic versus oncosuppressor behavior of metabolic genes, which includes those encoding mitochondrial complex I (CI) subunits. The prognostic value of nuclear genome mRNAs expression of CI subunits is to be evaluated in the tumor patients. We used the Kaplan Meier plotter database, the cBio Cancer Genomics Portal, and the Oncomine in which gene expression data and survival information were from thousands of tumor patients to assess the relevance of nuclear genome mRNAs level of CI subunits to patients' survival, as well as their alterations in gene and expression level in tumors. We presented that the relative expression level of overwhelming majority of the nuclear genes of CI subunits with survival significance (overall survival, relapse free survival, progression free survival, distant metastasis free survival, post progression survival, and first progression), had consistent effects for patients in each type of four tumors separately, including breast cancer, ovarian cancer, lung cancer, and gastric cancer. However, in gene level, frequent cumulative or individual alteration of these genes could not significantly affect patients' survival and the overexpression of the individual gene was not ubiquitous in tumors versus normal tissues. Given that reprogrammed energy metabolism was viewed as an emerging hallmark of tumor, thus tumor patients' survival might potentially to be evaluated by certain threshold for overall expression of CI subunits. Comprehensive understanding of the nuclear genome encoded CI subunits may have guiding significance for the diagnosis and prognosis in tumor patients.

  4. Efficient nuclear export of p65-IkappaBalpha complexes requires 14-3-3 proteins.

    Science.gov (United States)

    Aguilera, Cristina; Fernández-Majada, Vanessa; Inglés-Esteve, Julia; Rodilla, Verónica; Bigas, Anna; Espinosa, Lluís

    2006-09-01

    IkappaB are responsible for maintaining p65 in the cytoplasm under non-stimulating conditions and promoting the active export of p65 from the nucleus following NFkappaB activation to terminate the signal. We now show that 14-3-3 proteins regulate the NFkappaB signaling pathway by physically interacting with p65 and IkappaBalpha proteins. We identify two functional 14-3-3 binding domains in the p65 protein involving residues 38-44 and 278-283, and map the interaction region of IkappaBalpha in residues 60-65. Mutation of these 14-3-3 binding domains in p65 or IkappaBalpha results in a predominantly nuclear distribution of both proteins. TNFalpha treatment promotes recruitment of 14-3-3 and IkappaBalpha to NFkappaB-dependent promoters and enhances the binding of 14-3-3 to p65. Disrupting 14-3-3 activity by transfection with a dominant-negative 14-3-3 leads to the accumulation of nuclear p65-IkappaBalpha complexes and the constitutive association of p65 with the chromatin. In this situation, NFkappaB-dependent genes become unresponsive to TNFalpha stimulation. Together our results indicate that 14-3-3 proteins facilitate the nuclear export of IkappaBalpha-p65 complexes and are required for the appropriate regulation of NFkappaB signaling.

  5. Evaluation of the Safety Issue Concerning the Potential for Loss of Decay Heat Removal Function due to Crude Oil Spill in the Ultimate Heat Sink of Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Jong Chull; Roh, Kyung Wan; Yune, Young Gill; Kang, Dong Gu; Kim, Hho Jhung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2008-05-15

    A barge crashed into a moored oil tanker at about 7:15 a.m., Dec. 12, 2007, dumping around 10,500 tons of crude oil into the sea in Korea. The incident took place about 15 kilometers northwest of Manripo beach in South Chungcheong where is Korea's west coast in the Yellow Sea. In a few days, the oil slicks spread to the northern and southern tips of the Taean Peninsula by strong winds and tides. As time went the spilled oil floating on the surface of sea water was volatilized to become tar-balls and lumps and drifted far away in the southern direction. 13 days after the incident, some of oil slicks and tar lumps were observed to flow in the service water intake at the Younggwang nuclear power plants (NPPs) operating 6 reactors, which are over 150 km away from the incident spot in the southeastern direction. According to the report by the Younggwang NPPs, a total weight 83 kg of tar lumps was removed for about 3 days. Oil spills in the sea can happen in any country or anytime due to human errors or mistakes, wars, terrors, intentional dumping of waste oils, and natural disasters like typhoon and tsunami. In fact, there have been 7 major oil spills over 10,000 tons that have occurred around the world since 1983. As such serious oil spill incidents may happen near the operating power plants using the sea water as ultimate heat sink. To ensure the safe operation of nuclear reactors it is required to evaluate the potential for loss of decay heat removal function of nuclear reactors due to the spilled oils flowing in the service water intake, from which the service water is pumped. Thus, Korea Institute of Nuclear Safety identified this problem as one of the important safety. When an incident of crude oil spill from an oil carrier occurs in the sea near the nuclear power plants, the spilled oil can be transported to the intake pit, where all service water pumps locate, by sea current and wind drift (induced) current. The essential service water pumps take the

  6. Structural insights into SUN-KASH complexes across the nuclear envelope

    Institute of Scientific and Technical Information of China (English)

    Wenjia Wang; Zhaocai Zhou; Zhubing Shi; Shi Jiao; Cuicui Chen; Huizhen Wang; Guoguang Liu; Qiang Wang; Yun Zhao; Mark I Greene

    2012-01-01

    Linker of the nucleoskeleton and the cytoskeleton (LINC) complexes are composed of SUN and KASH domaincontaining proteins and bridge the inner and outer membranes of the nuclear envelope.LINC complexes play critical roles in nuclear positioning,cell polarization and cellular stiffness.Previously,we reported the homotrimeric structure of human SUN2.We have now determined the crystal structure of the human SUN2-KASH complex.In the complex structure,the SUN domain homotrimer binds to three independent "hook"-like KASH peptides.The overall conformation of the SUN domain in the complex closely resembles the SUN domain in its apo state.A major conformational change involves the AA'-loop of KASH-bound SUN domain,which rearranges to form a mini β-sheet that interacts with the KASH peptide.The PPPT motif of the KASH domain fits tightly into a hydrophobic pocket on the homotrimeric interface of the SUN domain,which we termed the BI-pocket.Moreover,two adjacent protomers of the SUN domain homotrimer sandwich the KASH domain by hydrophobic interaction and hydrogen bonding.Mutations of these binding sites disrupt or reduce the association between the SUN and KASH domains in vitro.In addition,transfection of wild-type,but not mutant,SUN2 promotes cell migration in Ovcar-3 cells.These results provide a structural model of the LINC complex,which is essential for additional study of the physical and functional coupling between the cytoplasm and the nucleoplasm.

  7. NeuN/Rbfox3 nuclear and cytoplasmic isoforms differentially regulate alternative splicing and nonsense-mediated decay of Rbfox2.

    Directory of Open Access Journals (Sweden)

    B Kate Dredge

    Full Text Available Anti-NeuN (Neuronal Nuclei is a monoclonal antibody used extensively to specifically detect post-mitotic neurons. Anti-NeuN reactivity is predominantly nuclear; by western it detects multiple bands ranging in molecular weight from 45 kDa to >75 kDa. Expression screening putatively identified R3hdm2 as NeuN; however immunoprecipitation and mass spectrometry of the two major NeuN species at 45-50 kDa identified both as the RNA binding protein Rbfox3 (a member of the Fox family of alternative splicing factors, confirming and extending the identification of the 45 kDa band as Rbfox3 by Kim et al. Mapping of the anti-NeuN reactive epitopes in both R3hdm2 and Rbfox3 reveals a common proline- and glutamine-rich domain that lies at the N-terminus of the Rbfox3 protein. Our data suggests that alternative splicing of the Rbfox3 pre-mRNA itself leads to the production of four protein isoforms that migrate in the 45-50 kDa range, and that one of these splicing choices regulates Rbfox3/NeuN sub-cellular steady-state distribution, through the addition or removal of a short C-terminal extension containing the second half of a bipartite hydrophobic proline-tyrosine nuclear localization signal. Rbfox3 regulates alternative splicing of the Rbfox2 pre-mRNA, producing a message encoding a dominant negative form of the Rbfox2 protein. We show here that nuclear Rbfox3 isoforms can also enhance the inclusion of cryptic exons in the Rbfox2 mRNA, resulting in nonsense-mediated decay of the message, thereby contributing to the negative regulation of Rbfox2 by Rbfox3 through a novel mechanism.

  8. Dissecting mechanisms of nuclear mRNA surveillance in THO/sub2 complex mutants

    DEFF Research Database (Denmark)

    Rougemaille, Mathieu; Gudipati, Rajani Kanth; Olesen, Jens Raabjerg

    2007-01-01

    The nuclear exosome is involved in numerous RNA metabolic processes. Exosome degradation of rRNA, snoRNA, snRNA and tRNA in Saccharomyces cerevisiae is activated by TRAMP complexes, containing either the Trf4p or Trf5p poly(A) polymerase. These enzymes are presumed to facilitate exosome access...... for both retention and degradation of nuclear restricted mRNAs. We show here that Trf4p, in the context of TRAMP, is an mRNA surveillance factor. However, unlike Rrp6p, Trf4p only partakes in RNA degradation and not in transcript retention. Surprisingly, a polyadenylation-defective Trf4p protein is fully...... active, suggesting polyadenylation-independent mRNA degradation. Transcription pulse–chase experiments show that HSP104 molecules undergoing quality control in THO/sub2 mutant strains fall into two distinct populations: One that is quickly degraded after transcription induction and another that escapes...

  9. Dissecting mechanisms of nuclear mRNA surveillance in THO/sub2 complex mutants

    DEFF Research Database (Denmark)

    Rougemaille, Mathieu; Gudipati, Rajani K; Olesen, Jens Raabjerg

    2007-01-01

    The nuclear exosome is involved in numerous RNA metabolic processes. Exosome degradation of rRNA, snoRNA, snRNA and tRNA in Saccharomyces cerevisiae is activated by TRAMP complexes, containing either the Trf4p or Trf5p poly(A) polymerase. These enzymes are presumed to facilitate exosome access...... is required for both retention and degradation of nuclear restricted mRNAs. We show here that Trf4p, in the context of TRAMP, is an mRNA surveillance factor. However, unlike Rrp6p, Trf4p only partakes in RNA degradation and not in transcript retention. Surprisingly, a polyadenylation-defective Trf4p protein...... is fully active, suggesting polyadenylation-independent mRNA degradation. Transcription pulse-chase experiments show that HSP104 molecules undergoing quality control in THO/sub2 mutant strains fall into two distinct populations: One that is quickly degraded after transcription induction and another...

  10. Ultrastructural Complexity of Nuclear Components During Early Apoptotic Phases in Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Christian Castelli

    2001-01-01

    Full Text Available Fractal morphometry was used to investigate the ultrastructural features of the plasma membrane, perinuclear membrane and nuclear chromatin in SK‐BR‐3 human breast cancer cells undergoing apoptosis. Cells were incubated with 1 μM calcimycin (A23187 for 24 h. Cells in the early stage of apoptosis had fractal dimension (FD values indicating that their plasma membranes were less rough (lower FD than those of control cells, while their perinuclear membranes were unaffected. Changes of the chromatin texture within the entire nucleus and in selected nuclear domains were more pronounced in treated cells. This confirms that the morphological reorganization imputable to a loss of structural complexity (reduced FD occurs in the early stage of apoptosis, is accompanied by the inhibition of distinct enzymatic events and precedes the onset of conventional cellular markers, which can only be detected during the active phases of the apoptotic process.

  11. Nuclear locus divergence at the early stages of speciation in the Orchard Oriole complex.

    Science.gov (United States)

    Sturge, Rachel J; Cortés-Rodríguez, M Nandadevi; Rojas-Soto, Octavio R; Omland, Kevin E

    2016-07-01

    As two lineages diverge from one another, mitochondrial DNA should evolve fixed differences more rapidly than nuclear DNA due to its smaller effective population size and faster mutation rate. As a consequence, molecular systematists have focused on the criteria of reciprocal monophyly in mitochondrial DNA for delimiting species boundaries. However, mitochondrial gene trees do not necessarily reflect the evolutionary history of the taxa in question, and even mitochondrial loci are not expected to be reciprocally monophyletic when the speciation event happened very recently. The goal of this study was to examine mitochondrial paraphyly within the Orchard Oriole complex, which is composed of Icterus spurius (Orchard Oriole) and Icterus fuertesi (Fuertes' Oriole). We increased the geographic sampling, added four nuclear loci, and used a range of population genetic and coalescent methods to examine the divergence between the taxa. With increased taxon sampling, we found evidence of clear structure between the taxa for mitochondrial DNA. However, nuclear loci showed little evidence of population structure, indicating a very recent divergence between I. spurius and I. fuertesi. Another goal was to examine the genetic variation within each taxon to look for evidence of a past founder event within the I. fuertesi lineage. Based on the high amounts of genetic variation for all nuclear loci, we found no evidence of such an event - thus, we found no support for the possible founding of I. fuertesi through a change in migratory behavior, followed by peripheral isolates speciation. Our results demonstrate that these two taxa are in the earliest stages of speciation, at a point when they have fixed differences in plumage color that are not reflected in monophyly of the mitochondrial or nuclear DNA markers in this study. This very recent divergence makes them ideal for continued studies of species boundaries and the earliest stages of speciation.

  12. Fundamentals of nuclear physics

    CERN Document Server

    Takigawa, Noboru

    2017-01-01

    This book introduces the current understanding of the fundamentals of nuclear physics by referring to key experimental data and by providing a theoretical understanding of principal nuclear properties. It primarily covers the structure of nuclei at low excitation in detail. It also examines nuclear forces and decay properties. In addition to fundamentals, the book treats several new research areas such as non-relativistic as well as relativistic Hartree–Fock calculations, the synthesis of super-heavy elements, the quantum chromodynamics phase diagram, and nucleosynthesis in stars, to convey to readers the flavor of current research frontiers in nuclear physics. The authors explain semi-classical arguments and derivation of its formulae. In these ways an intuitive understanding of complex nuclear phenomena is provided. The book is aimed at graduate school students as well as junior and senior undergraduate students and postdoctoral fellows. It is also useful for researchers to update their knowledge of diver...

  13. Contrasting complexing capacity of dissolved organic matter produced during the onset, development and decay of a simulated bloom of the marine diatom Skeletonema costatum

    OpenAIRE

    Lorenzo, J.I.; Nieto-cid, M.; Alvarez-Salgado, X.A.; Perez, P; Beiras, R.

    2007-01-01

    The capacity of natural dissolved organic matter (DOM) produced during the onset, development and decay of a simulated bloom of the marine diatom Skeletonema costatum to complex free copper has been followed for a 2 week period. Copper binding capacity of the culture was measured by anodic stripping voltammetry (ASV) with a hanging mercury drop electrode (HMDE). The concentration of dissolved organic carbon (DOC) and two fluorophores, M (humic-like, Ex/Em: 320 nm/410 nm) and T (protein-like, ...

  14. Neurochemical dynamics of acute orofacial pain in the human trigeminal brainstem nuclear complex.

    Science.gov (United States)

    de Matos, Nuno M P; Hock, Andreas; Wyss, Michael; Ettlin, Dominik A; Brügger, Mike

    2017-09-04

    The trigeminal brainstem sensory nuclear complex is the first central relay structure mediating orofacial somatosensory and nociceptive perception. Animal studies suggest a substantial involvement of neurochemical alterations at such basal CNS levels in acute and chronic pain processing. Translating this animal based knowledge to humans is challenging. Human related examining of brainstem functions are challenged by MR related peculiarities as well as applicability aspects of experimentally standardized paradigms. Based on our experience with an MR compatible human orofacial pain model, the aims of the present study were twofold: 1) from a technical perspective, the evaluation of proton magnetic resonance spectroscopy at 3 T regarding measurement accuracy of neurochemical profiles in this small brainstem nuclear complex and 2) the examination of possible neurochemical alterations induced by an experimental orofacial pain model. Data from 13 healthy volunteers aged 19-46 years were analyzed and revealed high quality spectra with significant reductions in total N-acetylaspartate (N-acetylaspartate + N-acetylaspartylglutamate) (-3.7%, p = 0.009) and GABA (-10.88%, p = 0.041) during the pain condition. These results might reflect contributions of N-acetylaspartate and N-acetylaspartylglutamate in neuronal activity-dependent physiologic processes and/or excitatory neurotransmission, whereas changes in GABA might indicate towards a reduction in tonic GABAergic functioning during nociceptive signaling. Summarized, the present study indicates the applicability of (1)H-MRS to obtain neurochemical dynamics within the human trigeminal brainstem sensory nuclear complex. Further developments are needed to pave the way towards bridging important animal based knowledge with human research to understand the neurochemistry of orofacial nociception and pain. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. The nuclear pore complex mystery and anomalous diffusion in reversible gels.

    Science.gov (United States)

    Bickel, Thomas; Bruinsma, Robijn

    2002-01-01

    The exchange of macromolecules between the cytoplasm and the nucleus of eukaryotic cells takes place through the nuclear pore complex (NPC), which contains a selective permeability barrier. Experiments on the physical properties of this barrier appear to be in conflict with current physical understanding of the rheology of reversible gels. This paper proposes that the NPC gel is anomalous and characterized by connectivity fluctuations. It develops a simplified model to demonstrate the possibility of enhanced diffusion constants of macromolecules trapped in such a gel. PMID:12496079

  16. Nuclear Weapons Complex Reconfiguration: Analysis of an Energy Department Task Force Report

    Science.gov (United States)

    2006-02-01

    pdf ]. 3 Letter from Dr. David O. Overskei, Chairman, SEAB Nuclear Weapons Complex Infrastructure Task Force, to M. Peter McPherson, Chairman...slides, available at [http://www.ligo.caltech.edu/ LIGO_web/seminars/ pdf /wilkinson.pdf]. pit for the W88 warhead in 2007. The TF estimates that TA-55...teamwork by designating many of its facilities as User Facilities. Examples of such facilities are the high-energy density devices (e.g., the NIF [LLNL’s

  17. Toward the atomic structure of the nuclear pore complex: when top down meets bottom up.

    Science.gov (United States)

    Hoelz, André; Glavy, Joseph S; Beck, Martin

    2016-07-01

    Elucidating the structure of the nuclear pore complex (NPC) is a prerequisite for understanding the molecular mechanism of nucleocytoplasmic transport. However, owing to its sheer size and flexibility, the NPC is unapproachable by classical structure determination techniques and requires a joint effort of complementary methods. Whereas bottom-up approaches rely on biochemical interaction studies and crystal-structure determination of NPC components, top-down approaches attempt to determine the structure of the intact NPC in situ. Recently, both approaches have converged, thereby bridging the resolution gap from the higher-order scaffold structure to near-atomic resolution and opening the door for structure-guided experimental interrogations of NPC function.

  18. Mice lacking TR4 nuclear receptor develop mitochondrial myopathy with deficiency in complex I.

    Science.gov (United States)

    Liu, Su; Lee, Yi-Fen; Chou, Samuel; Uno, Hideo; Li, Gonghui; Brookes, Paul; Massett, Michael P; Wu, Qiao; Chen, Lu-Min; Chang, Chawnshang

    2011-08-01

    The estimated incidence of mitochondrial diseases in humans is approximately 1:5000 to 1:10,000, whereas the molecular mechanisms for more than 50% of human mitochondrial disease cases still remain unclear. Here we report that mice lacking testicular nuclear receptor 4 (TR4(-/-)) suffered mitochondrial myopathy, and histological examination of TR4(-/-) soleus muscle revealed abnormal mitochondrial accumulation. In addition, increased serum lactate levels, decreased mitochondrial ATP production, and decreased electron transport chain complex I activity were found in TR4(-/-) mice. Restoration of TR4 into TR4(-/-) myoblasts rescued mitochondrial ATP generation capacity and complex I activity. Further real-time PCR quantification and promoter studies found TR4 could modulate complex I activity via transcriptionally regulating the complex I assembly factor NDUFAF1, and restoration of NDUFAF1 level in TR4(-/-) myoblasts increased mitochondrial ATP generation capacity and complex I activity. Together, these results suggest that TR4 plays vital roles in mitochondrial function, which may help us to better understand the pathogenesis of mitochondrial myopathy, and targeting TR4 via its ligands/activators may allow us to develop better therapeutic approaches.

  19. Material control and accounting in the Department of Energy's nuclear fuel complex

    Energy Technology Data Exchange (ETDEWEB)

    None

    1989-01-01

    Material control and accounting takes place within an envelope of activities related to safeguards and security, as well as to safety, health, and environment, all of which need to be managed to assure that the entire nuclear fuel complex can operate in a societally accepted manner. Within this envelope the committee was directed to carry out the following scope of work: (1) Review the MCandA systems in use at selected DOE facilities that are processing special nuclear material (SNM) in various physical and chemical forms. (2) Design and convene a workshop for senior representatives from each of DOE's facilities on the flows and inventories of nuclear materials. (3) Plan and conduct a series of site visits to each of the facilities to observe first hand the processing operations and the related MCandA systems. (4) Review the potential improvement in overall safeguard systems effectiveness, as measured by expected reduction in inventory difference control limits and inventory differences for materials balance accounts and facilities, or other criteria as appropriate. Indicate how this affects the relative degree of uncertainty in the system. (5) Review the efficiency of operating the MCandA system with and without the upgrading options and assess whether upgrading will contribute further efficiencies in operation, which may reduce many of the current operations costs. Determine if the current system is cost-effective. (6) Recommend the most promising technical approaches for further development by DOE and further study as warranted.

  20. Complex evolution in Arundinarieae (Poaceae: Bambusoideae): incongruence between plastid and nuclear GBSSI gene phylogenies.

    Science.gov (United States)

    Zhang, Yu-Xiao; Zeng, Chun-Xia; Li, De-Zhu

    2012-06-01

    The monophyly of tribe Arundinarieae (the temperate woody bamboos) has been unequivocally recovered in previous molecular phylogenetic studies. In a recent phylogenetic study, 10 major lineages in Arundinarieae were resolved based on eight non-coding plastid regions, which conflicted significantly with morphological classifications both at the subtribal and generic levels. Nevertheless, relationships among and within the 10 lineages remain unclear. In order to further unravel the evolutionary history of Arundinarieae, we used the nuclear GBSSI gene sequences along with those of eight plastid regions for phylogenetic reconstruction, with an emphasis on Chinese species. The results of the plastid analyses agreed with previous studies, whereas 13 primary clades revealed in the GBSSI phylogeny were better resolved at the generic level than the plastid phylogeny. Our analyses also revealed many inconsistencies between the plastid DNA and the nuclear GBSSI trees. These results implied that the nuclear genome and the plastid genome had different evolutionary trajectories. The patterns of incongruence suggested that lack of informative characters, incomplete lineage sorting, and/or hybridization (introgression) could be the causes. Seven putative hybrid species were hypothesized, four of which are discussed in detail on the basis of topological incongruence, chromosome numbers, morphology, and distribution patterns, and those taxa probably resulted from homoploid hybrid speciation. Overall, our study indicates that the tribe Arundinarieae has undergone a complex evolution. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Environmental assessment report: Nuclear Test Technology Complex. [Construction and operation of proposed facility

    Energy Technology Data Exchange (ETDEWEB)

    Tonnessen, K.; Tewes, H.A.

    1982-08-01

    The US Department of Energy (USDOE) is planning to construct and operate a structure, designated the Nuclear Test Technology Complex (NTTC), on a site located west of and adjacent to the Lawrence Livermore National Laboratory. The NTTC is designed to house 350 nuclear test program personnel, and will accommodate the needs of the entire staff of the continuing Nuclear Test Program (NTP). The project has three phases: land acquisition, facility construction and facility operation. The purpose of this environmental assessment report is to describe the activities associated with the three phases of the NTTC project and to evaluate potential environmental disruptions. The project site is located in a rural area of southeastern Alameda County, California, where the primary land use is agriculture; however, the County has zoned the area for industrial development. The environmental impacts of the project include surface disturbance, high noise levels, possible increases in site erosion, and decreased air quality. These impacts will occur primarily during the construction phase of the NTTC project and can be mitigated in part by measures proposed in this report.

  2. Application of Nuclear Magnetic Resonance and Hybrid Methods to Structure Determination of Complex Systems.

    Science.gov (United States)

    Prischi, Filippo; Pastore, Annalisa

    2016-01-01

    The current main challenge of Structural Biology is to undertake the structure determination of increasingly complex systems in the attempt to better understand their biological function. As systems become more challenging, however, there is an increasing demand for the parallel use of more than one independent technique to allow pushing the frontiers of structure determination and, at the same time, obtaining independent structural validation. The combination of different Structural Biology methods has been named hybrid approaches. The aim of this review is to critically discuss the most recent examples and new developments that have allowed structure determination or experimentally-based modelling of various molecular complexes selecting them among those that combine the use of nuclear magnetic resonance and small angle scattering techniques. We provide a selective but focused account of some of the most exciting recent approaches and discuss their possible further developments.

  3. Study of the Nuclear Fusion in $d \\mu{}^{3}\\mathrm{He}$ Complex

    CERN Document Server

    Bystritsky, V M; Gerasimov, V V; Knowles, P E; Mulhauser, F; Popov, N P; Volnykh, V P; Wozniak, J

    2005-01-01

    Experimental study of the nuclear fusion reaction in charge-asymmetrical $d \\mu{}^{3}\\mathrm{He}$ complex ($d \\mu{}^{3}\\mathrm{He} \\rightarrow \\alpha$ (3.5 MeV) + $p$ (14.64 MeV)) is presented. The 14.64-MeV protons were detected by three pairs of Si($dE-E$) telescopes placed around the cryogenic target filled with the $\\mathrm{D}_2 + {}^{3}\\mathrm{He}$ gas at 34 K. The 6.85 keV $\\gamma$ rays emitted during the de-excitation of the $d \\mu{}^3 \\mathrm{He}$ complex were detected by a germanium detector. The measurements were performed at two $\\mathrm{D}_2 + {^{3}\\mathrm{He}}$ target densities, $\\varphi = 0.0585$ and $\\varphi = 0.169$ (relative to liquid hydrogen density) with an atomic concentration of $^{3}\\mathrm{He}$ $c_{{}^3\\mathrm{He}} = 0.0469$. The values of the effective rate of nuclear fusion in $d \\mu{}^3\\mathrm{He}$ was obtained for the first time: $\\tilde{\\lambda}_{f} = (4.5^{+2.6}_{-2.0}) \\cdot 10^5 \\mbox{s}^{-1} (\\varphi = 0.0585)$; $\\tilde{\\lambda}_{f} = (6.9^{+3.6}_{-3.0}) \\cdot 10^5 \\mbox{s}^{-...

  4. The Nuclear Cap-Binding Complex Mediates Meiotic Silencing by Unpaired DNA

    Science.gov (United States)

    Decker, Logan M.; Xiao, Hua; Boone, Erin C.; Vierling, Michael M.; Shanker, Benjamin S.; Kingston, Shanika L.; Boone, Shannon F.; Haynes, Jackson B.; Shiu, Patrick K.T.

    2017-01-01

    In the filamentous fungus Neurospora crassa, cross walls between individual cells are normally incomplete, making the entire fungal network vulnerable to attack by viruses and selfish DNAs. Accordingly, several genome surveillance mechanisms are maintained to help the fungus combat these repetitive elements. One of these defense mechanisms is called meiotic silencing by unpaired DNA (MSUD), which identifies and silences unpaired genes during meiosis. Utilizing common RNA interference (RNAi) proteins, such as Dicer and Argonaute, MSUD targets mRNAs homologous to the unpaired sequence to achieve silencing. In this study, we have identified an additional silencing component, namely the cap-binding complex (CBC). Made up of cap-binding proteins CBP20 and CBP80, CBC associates with the 5′ cap of mRNA transcripts in eukaryotes. The loss of CBC leads to a deficiency in MSUD activity, suggesting its role in mediating silencing. As confirmed in this study, CBC is predominantly nuclear, although it is known to travel in and out of the nucleus to facilitate RNA transport. As seen in animals but not in plants, CBP20’s robust nuclear import depends on CBP80 in Neurospora. CBC interacts with a component (Argonaute) of the perinuclear meiotic silencing complex (MSC), directly linking the two cellular factors. PMID:28179391

  5. The Nuclear Cap-Binding Complex Mediates Meiotic Silencing by Unpaired DNA

    Directory of Open Access Journals (Sweden)

    Logan M. Decker

    2017-04-01

    Full Text Available In the filamentous fungus Neurospora crassa, cross walls between individual cells are normally incomplete, making the entire fungal network vulnerable to attack by viruses and selfish DNAs. Accordingly, several genome surveillance mechanisms are maintained to help the fungus combat these repetitive elements. One of these defense mechanisms is called meiotic silencing by unpaired DNA (MSUD, which identifies and silences unpaired genes during meiosis. Utilizing common RNA interference (RNAi proteins, such as Dicer and Argonaute, MSUD targets mRNAs homologous to the unpaired sequence to achieve silencing. In this study, we have identified an additional silencing component, namely the cap-binding complex (CBC. Made up of cap-binding proteins CBP20 and CBP80, CBC associates with the 5′ cap of mRNA transcripts in eukaryotes. The loss of CBC leads to a deficiency in MSUD activity, suggesting its role in mediating silencing. As confirmed in this study, CBC is predominantly nuclear, although it is known to travel in and out of the nucleus to facilitate RNA transport. As seen in animals but not in plants, CBP20’s robust nuclear import depends on CBP80 in Neurospora. CBC interacts with a component (Argonaute of the perinuclear meiotic silencing complex (MSC, directly linking the two cellular factors.

  6. Mortality from malignant tumors in hematopoiotic and lymphatic tissues among personnel of the first nuclear production complex in the USSR

    Energy Technology Data Exchange (ETDEWEB)

    Kochurnikova, N.A.; Buldakov, L.A.; Bysogolov, G.D. [Institute of Biophysics, Moscow (Russian Federation)] [and others

    1992-06-01

    This paper reports on results from the study of haemo-lymphoblostosis (HLB) mortality among personnel of the first nuclear materials production complex in the USSR in 1948-1953. A cohort of men started to work in the same complex in 1954-58 was used as a comparative group. 6 refs., 4 figs., 6 tabs.

  7. Friend of Prmt1, FOP is a novel component of the nuclear SMN complex isolated using biotin affinity purification

    NARCIS (Netherlands)

    K. Izumikawa (Keiichi); H. Ishikawa (Hiroki); H. Yoshikawa (Harunori); G. Terukina (Goro); N. Miyazawa (Naoki); H. Nakayama (Hiroshi); Y. Nobe (Yuko); M. Taoka (Masato); N. Yamauchi (Naoto); J.N.J. Philipsen (Sjaak); T. Isobe (Toshiaki); N. Takahashi (Nozomi)

    2014-01-01

    textabstractSMN (survival motor neuron protein) complexes are essential for the biogenesis of uridine-rich small nuclear ribonucleoproteins (UsnRNPs). During the biogenesis, the SMN complexes bound to UsnRNPs are transported from the cytoplasm to the nucleus, and moved to Cajal body (bodies)/Gems (C

  8. RNA-guided assembly of Rev-RRE nuclear export complexes.

    Science.gov (United States)

    Bai, Yun; Tambe, Akshay; Zhou, Kaihong; Doudna, Jennifer A

    2014-08-27

    HIV replication requires nuclear export of unspliced and singly spliced viral transcripts. Although a unique RNA structure has been proposed for the Rev-response element (RRE) responsible for viral mRNA export, how it recruits multiple HIV Rev proteins to form an export complex has been unclear. We show here that initial binding of Rev to the RRE triggers RNA tertiary structural changes, enabling further Rev binding and the rapid formation of a viral export complex. Analysis of the Rev-RRE assembly pathway using SHAPE-Seq and small-angle X-ray scattering (SAXS) reveals two major steps of Rev-RRE complex formation, beginning with rapid Rev binding to a pre-organized region presenting multiple Rev binding sites. This step induces long-range remodeling of the RNA to expose a cryptic Rev binding site, enabling rapid assembly of additional Rev proteins into the RNA export complex. This kinetic pathway may help maintain the balance between viral replication and maturation.DOI: http://dx.doi.org/10.7554/eLife.03656.001.

  9. The NDUFS4 nuclear gene of complex I of mitochondria and the cAMP cascade.

    Science.gov (United States)

    Papa, Sergio

    2002-09-10

    Results of studies on the role of the 18 kDa (IP) polypeptide subunit of complex I, encoded by the nuclear NDUFS4 gene, in isolated bovine heart mitochondria and human and murine cell cultures are presented.The mammalian 18 kDa subunit has in the carboxy-terminal sequence a conserved consensus site (RVS), which in isolated mitochondria is phosphorylated by cAMP-dependent protein kinase (PKA). The catalytic and regulatory subunits of PKA have been directly immunodetected in the inner membrane/matrix fraction of mammalian mitochondria. In the mitochondrial inner membrane a PP2Cgamma-type phosphatase has also been immunodetected, which dephosphorylates the 18 kDa subunit, phosphorylated by PKA. This phosphatase is Mg(2+)-dependent and inhibited by Ca(2+). In human and murine fibroblast and myoblast cultures "in vivo", elevation of intracellular cAMP level promotes phosphorylation of the 18 kDa subunit and stimulates the activity of complex I and NAD-linked mitochondrial respiration. Four families have been found with different mutations in the cDNA of the NDUFS4 gene. These mutations, transmitted by autosomal recessive inheritance, were associated in homozygous children with fatal neurological syndrome. All these mutations destroyed the phosphorylation consensus site in the C terminus of the 18 kDa subunit, abolished cAMP activation of complex I and impaired its normal assembly.

  10. 20S small nuclear ribonucleoprotein U5 shows a surprisingly complex protein composition.

    Science.gov (United States)

    Bach, M; Winkelmann, G; Lührmann, R

    1989-08-01

    U5 small nuclear ribonucleoprotein (snRNP), purified from HeLa nuclear extracts (splicing extracts), shows a complex protein composition. In addition to the snRNP proteins B', B, D, D', E, F, and G, which are present in each of the major snRNPs U1, U2, U4/U6, and U5, U5 snRNP contains a number of unique proteins characterized by apparent molecular masses of 40, 52, 100, 102, 116, and 200 (mostly a double band) kDa. The latter set of proteins may be regarded as U5-specific for the following reasons. They are not only eluted specifically, together with snRNP particles, from anti-2,2,7-trimethylguanosine immunoaffinity columns by 7-methylguanosine, they also cofractionate with U5 snRNP during chromatography and, most importantly, in glycerol gradient centrifugation. These U5 snRNP particles show a high sedimentation constant of about 20S. U5 snRNPs that lack the U5-specific proteins are also found in nuclear extracts but have (in comparison) a lower sedimentation value of only 8-10S. Autoimmune sera from patients with systemic lupus erythematosus were identified that, on immunoblots with purified U5 snRNP proteins, reacted selectively with the 100- or 200-kDa proteins. This indicates that at least the high molecular mass U5-specific proteins are structurally distinct and not derived one from the other by proteolytic degradation. The existence of so many unique proteins in the U5 snRNP suggests that this snRNP particle may exert its function during splicing mainly by virtue of its protein components.

  11. Bis-gadolinium complexes for solid effect and cross effect dynamic nuclear polarization

    Energy Technology Data Exchange (ETDEWEB)

    Kaushik, Monu; Corzilius, Bjoern [Goethe-Universitaet Frankfurt am Main, Institut fuer Physikalische und Theoretische Chemie, Institut fuer Biophysikalische Chemie und Biomolekulares Magnetresonanzzentrum (BMRZ) (Germany); Qi, Mian; Godt, Adelheid [Fakultaet fuer Chemie und Centrum fuer Molekulare Materialien (CM2), Universitaet Bielefeld (Germany)

    2017-04-03

    High-spin complexes act as polarizing agents (PAs) for dynamic nuclear polarization (DNP) in solid-state NMR spectroscopy and feature promising aspects towards biomolecular DNP. We present a study on bis(Gd-chelate)s which enable cross effect (CE) DNP owing to spatial confinement of two dipolar-coupled electron spins. Their well-defined Gd..Gd distances in the range of 1.2-3.4 nm allowed us to elucidate the Gd..Gd distance dependence of the DNP mechanism and NMR signal enhancement. We found that Gd..Gd distances above 2.1 nm result in solid effect DNP while distances between 1.2 and 2.1 nm enable CE for {sup 1}H, {sup 13}C, and {sup 15}N nuclear spins. We compare 263 GHz electron paramagnetic resonance (EPR) spectra with the obtained DNP field profiles and discuss possible CE matching conditions within the high-spin system and the influence of dipolar broadening of the EPR signal. Our findings foster the understanding of the CE mechanism and the design of high-spin PAs for specific applications of DNP. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Nucleoporin domain topology is linked to the transport status of the nuclear pore complex.

    Science.gov (United States)

    Paulillo, Sara M; Phillips, Erica M; Köser, Joachim; Sauder, Ursula; Ullman, Katharine S; Powers, Maureen A; Fahrenkrog, Birthe

    2005-08-26

    Nuclear pore complexes (NPCs) facilitate macromolecular exchange between the nucleus and cytoplasm of eukaryotic cells. The vertebrate NPC is composed of approximately 30 different proteins (nucleoporins), of which around one third contain phenylalanine-glycine (FG)-repeat domains that are thought to mediate the main interaction between the NPC and soluble transport receptors. We have recently shown that the FG-repeat domain of Nup153 is flexible within the NPC, although this nucleoporin is anchored to the nuclear side of the NPC. By using domain-specific antibodies, we have now mapped the domain topology of Nup214 in Xenopus oocytes and in human somatic cells by immuno-EM. We have found that whereas Nup214 is anchored to the cytoplasmic side of the NPC via its N-terminal and central domain, its FG-repeat domain appears flexible, residing on both sides of the NPC. Moreover, the spatial distribution of the FG-repeat domains of both Nup153 and Nup214 shifts in a transport-dependent manner, suggesting that the location of FG-repeat domains within the NPC correlates with cargo/receptor interactions and that they concomitantly move with cargo through the central pore of the NPC.

  13. Modeling Electronic-Nuclear Interactions for Excitation Energy Transfer Processes in Light-Harvesting Complexes.

    Science.gov (United States)

    Lee, Mi Kyung; Coker, David F

    2016-08-18

    An accurate approach for computing intermolecular and intrachromophore contributions to spectral densities to describe the electronic-nuclear interactions relevant for modeling excitation energy transfer processes in light harvesting systems is presented. The approach is based on molecular dynamics (MD) calculations of classical correlation functions of long-range contributions to excitation energy fluctuations and a separate harmonic analysis and single-point gradient quantum calculations for electron-intrachromophore vibrational couplings. A simple model is also presented that enables detailed analysis of the shortcomings of standard MD-based excitation energy fluctuation correlation function approaches. The method introduced here avoids these problems, and its reliability is demonstrated in accurate predictions for bacteriochlorophyll molecules in the Fenna-Matthews-Olson pigment-protein complex, where excellent agreement with experimental spectral densities is found. This efficient approach can provide instantaneous spectral densities for treating the influence of fluctuations in environmental dissipation on fast electronic relaxation.

  14. Stability of Complex Biomolecular Structures: Vander Waals, Hydrogen Bond Cooperativity, and Nuclear Quantum Effects

    CERN Document Server

    Rossi, Mariana; Michaelides, Angelos

    2016-01-01

    Biomolecules are complex systems stabilized by a delicate balance of weak interactions, making it important to assess all energetic contributions in an accurate manner. However, it is a priori unclear which contributions make more of an impact. Here, we examine stacked polyglutamine (polyQ) strands, a peptide repeat often found in amyloid aggregates. We investigate the role of hydrogen bond (HB) cooperativity, van der Waals (vdW) dispersion interactions, and quantum contributions to free energies, including anharmonicities through density functional theory and ab initio path integral simulations. Of these various factors, we find that the largest impact on structural stabilization comes from vdW interactions. HB cooperativity is the second largest contribution as the size of the stacked chain grows. Competing nuclear quantum effects make the net quantum contribution small but very sensitive to anharmonicities, vdW, and the number of HBs. Our results suggest that a reliable treatment of these systems can only ...

  15. Industrial Complex for Solid Radwaste Management at Chernobyle Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Ahner, S.; Fomin, V. V.

    2002-02-26

    In the framework of the preparation for the decommissioning of the Chernobyl Nuclear Power Plant (ChNPP) an Industrial Complex for Solid Radwaste Management (ICSRM) will be built under the EC TACIS Program in the vicinity of ChNPP. The paper will present the proposed concepts and their integration into existing buildings and installations. Further, the paper will consider the safety cases, as well as the integration of Western and Ukrainian Organizations into a cohesive project team and the requirement to guarantee the fulfillment of both Western standards and Ukrainian regulations and licensing requirements. The paper will provide information on the status of the interim design and the effects of value engineering on the output of basic design phase. The paper therefor summarizes the design results of the involved design engineers of the Design and Process Providers BNFL (LOT 1), RWE NUKEM GmbH (LOT 2 and General) and INITEC (LOT 3).

  16. Screening level dose assessment of aquatic biota downstream of the Marcoule nuclear complex in southern France.

    Science.gov (United States)

    St-Pierre, S; Chambers, D B; Lowe, L M; Bontoux, J G

    1999-09-01

    Aquatic biota in the Rhone River downstream of the Marcoule nuclear complex in France are exposed to natural sources of radiation and to radioactivity released from the Marcoule complex. A simple conservative screening level model was used to estimate the range of concentrations in aquatic media (water, sediments, and aquatic organisms) of both artificial and natural radionuclides and the consequent absorbed (whole body) dose rates for aquatic organisms. Five categories of aquatic organisms were studied, namely, submerged aquatic plants (phanerogam), non-bottom-feeding fish, bottom-feeding fish, mollusca, and fish-eating birds. The analysis was based on the radionuclide concentrations reported in four consecutive annual radioecological monitoring reports published by French agencies with nuclear regulatory responsibilities. The results of this assessment were used to determine, qualitatively, the magnitude of any potential health impacts on each of the five categories of aquatic organisms studied. The range of dose rate estimates ranged over three orders of magnitude, with maximum dose rates estimated to be in the order of 1 to 10 microGy h(-1). These maximum dose rates are a factor 40 or more below the international guideline intended to ensure the protection of aquatic populations (about 400 microGy h(-1)), and a factor ten or more below the level which may trigger the need for a more detailed evaluation of potential ecological consequences to the exposed populations (about 100 microGy h(-1)). As a result, chronic levels of radioactivity, artificial and natural, measured in aquatic media downstream of Marcoule are unlikely to result in adverse health impacts on the categories and species of aquatic organisms studied. Thus, based on the screening level analysis discussed in this paper, a more detailed evaluation of the dose rates does not appear to be warranted.

  17. Bi-exponential decay of Eu(III) complexed by Suwannee River humic substances: spectroscopic evidence of two different excited species.

    Science.gov (United States)

    Reiller, Pascal E; Brevet, Julien

    2010-02-01

    The bi-exponential luminescence decay of europium (III) complexed by Suwannee River fulvic acid (SRFA) and humic acid (SRHA), is studied in time-resolved luminescence spectroscopy using two different gratings at varying delay after the laser pulse, increasing accumulation time in order to obtain comparable signals. The two hypotheses found in the literature to interpret this bi-exponential decay are (i) a back transfer from the metal to the triplet state of the organic ligand and (ii) the radiative decay of two different excited species. It is shown that evolutions of the (5)D(0)-->(7)F(0) and (5)D(0)-->(7)F(2) luminescent transitions are occurring between 10 and 300 micros delay. First, the (5)D(0)-->(7)F(0) transition is decreasing relative to the (5)D(0)-->(7)F(1) showing a slightly greater symmetry of the 'slow' component, and is also slightly red shifted. Second, a slight modification of the (5)D(0)-->(7)F(2) transition is also evidencing a slightly different ligand field splitting. No significant modification of the (5)D(0)-->(7)F(1) magnetic dipole, which is less susceptible to symmetry changes, is noted in line with expectations. The (5)D(0)-->(7)F(0) transitions are adjusted with either one or two components. The use of a simple component fit seems to be well adapted for representing an average comportment of these heterogeneous compounds, and a two-component fit constrained by the bi-exponential decay parameters and accumulation times yields in the proposition of the spectra for the fast and slow components. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  18. Bi-exponential decay of Eu(III) complexed by Suwannee River humic substances: Spectroscopic evidence of two different excited species

    Energy Technology Data Exchange (ETDEWEB)

    Reiller, P. E.; Brevet, J. [CEA, CE Saclay, DEN, DANS, DPC, SECR, Lab Speciat Radionucleides and Mol, F-91191 Gif Sur Yvette (France); Reiller, P. E.; Brevet, J. [Univ Evry Val Essonne, Lab Anal and Environm Biol abd Environm, CNRS, UMR 8587, F-91025 Evry (France)

    2010-07-01

    The bi-exponential luminescence decay of europium (III) complexed by Suwannee River fulvic acid (SRFA) and humic acid (SRHA), is studied in time-resolved luminescence spectroscopy using two different gratings at varying delay after the laser pulse, increasing accumulation time in order to obtain comparable signals. The two hypotheses found in the literature to interpret this bi-exponential decay are (i) a back transfer from the metal to the triplet state of the organic ligand and (ii) the radiative decay of two different excited species. It is shown that evolutions of the {sup 5}D{sub 0} -> {sup 7}F{sub 0} and {sup 5}D{sub 0} -> {sup 7}F{sub 2} luminescent transitions are occurring between 10 and 300 {mu}s delay. First, the {sup 5}D{sub 0} -> {sup 7}F{sub 0} transition is decreasing relative to the {sup 5}D{sub 0} -> {sup 7}F{sub 1} showing a slightly greater symmetry of the 'slow' component, and is also slightly red shifted. Second, a slight modification of the {sup 5}D{sub 0} -> {sup 7}F{sub 2} transition is also evidencing a slightly different ligand field splitting. No significant modification of the {sup 5}D{sub 0} -> {sup 7}F{sub 1} magnetic dipole, which is less susceptible to symmetry changes, is noted in line with expectations. The {sup 5}D{sub 0} -> {sup 7}F{sub 0} transitions are adjusted with either one or two components. The use of a simple component fit seems to be well adapted for representing an average comportment of these heterogeneous compounds, and a two-component fit constrained by the bi-exponential decay parameters and accumulation times yields in the proposition of the spectra for the fast and slow components. (authors)

  19. Refinement of the gross theory of nuclear {beta}-decay, and hindrance of the first-forbidden transition of rank 1

    Energy Technology Data Exchange (ETDEWEB)

    Nakata, Hidehiko [Waseda Univ., Tokyo (Japan). Dept. of Physics; Tachibana, Takahiro; Yamada, Masami

    1997-03-01

    Recently the gross theory of nuclear {beta}-decay was refined for odd-odd nuclei. In this refinement, the effect of the selection rule of {beta}-transitions from the ground states of odd-odd nuclei to those of even-even nuclei was taken into account based on a statistical consideration. The transitions to the first 2{sup +} excited states in even-even nuclei were also taken into account according to the selection rule approximately. In that study, it was found that the transitions between 1{sup -} ground states of the odd-odd nuclei and 0{sup +} ground states of even-even nuclei, belonging to the first-forbidden transitions of rank 1, are strongly hindered. A reduction factor was introduced for the transitions to the ground states of even-even nuclei to take into account this hindrance. It was also found that the strength functions of the Gamow-Teller transitions obtained from the conventional gross theory are underestimated by a factor of about 3. In order to improve this underestimation, the Lorentz-type function was adopted for the one-particle strength function in the model instead of the hyperbolic-secant-type function. In the present study we have newly analyzed the experimental ft-values of odd-A nuclei, and found that the first-forbidden transitions of rank 1 are also considerably hindered between the ground states. Following the above refinement we have calculated the {beta}-ray spectra of some odd-odd short-lived fission products with the use of the refined gross theory. These results are compared not only with the experiments by Rudstam et al. but also with the conventional gross theory. (author)

  20. Investigations of nuclear structure and nuclear reactions induced by complex projectiles. Progress report, September 1, 1991--August 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.

    1992-12-01

    The research program described touches five areas of nuclear physics: nuclear structure studies at high spin (hyperdeformation in the mass A {approx_equal} 182 region, structure of {sup 182}Hg and {sup 182}Au at high spin, a highly deformed band in {sup 136}Pm and the anomalous h{sub 11/2} proton crossing in the A{approximately}135 superdeformed region), studies at the interface between structure and reactions (population of entry states in heavy-ion fusion reactions, nuclear structure effects in proton evaporation spectra, nuclear structure- dependent entry state population by total spectroscopy, entrance channel effects in fusion near the barrier, lifetimes of subbarrier {alpha} particles by the atomic clock method), production and study of hot nuclei (the statistical model evaporation code EVAP, statistical emission of deuterons and tritons from highly excited compound nuclei, heavy-fragment emission as a probe of the thermal properties of highly excited compound nuclei, use of incoming-wave boundary condition transmission coefficients in the statistical model: implications in the particle evaporation spectra, study of transparency in the optical model), reaction mechanism studies (binary character of highly dissipative {sup 209}Bi + {sup 136}Xe collisions at E/A=28.2 MeV), and development and use of novel techniques and instrumentation in these areas of research (including a 4{pi} channel selection device, a novel x-ray detector, and a simple channel-selecting detector).

  1. Investigations of nuclear structure and nuclear reactions induced by complex projectiles. [Dept. of Chemistry, Washington Univ. , St. Louis, Mo

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.

    1992-01-01

    The research program described touches five areas of nuclear physics: nuclear structure studies at high spin (hyperdeformation in the mass A [approx equal] 182 region, structure of [sup 182]Hg and [sup 182]Au at high spin, a highly deformed band in [sup 136]Pm and the anomalous h[sub 11/2] proton crossing in the A[approximately]135 superdeformed region), studies at the interface between structure and reactions (population of entry states in heavy-ion fusion reactions, nuclear structure effects in proton evaporation spectra, nuclear structure- dependent entry state population by total spectroscopy, entrance channel effects in fusion near the barrier, lifetimes of subbarrier [alpha] particles by the atomic clock method), production and study of hot nuclei (the statistical model evaporation code EVAP, statistical emission of deuterons and tritons from highly excited compound nuclei, heavy-fragment emission as a probe of the thermal properties of highly excited compound nuclei, use of incoming-wave boundary condition transmission coefficients in the statistical model: implications in the particle evaporation spectra, study of transparency in the optical model), reaction mechanism studies (binary character of highly dissipative [sup 209]Bi + [sup 136]Xe collisions at E/A=28.2 MeV), and development and use of novel techniques and instrumentation in these areas of research (including a 4[pi] channel selection device, a novel x-ray detector, and a simple channel-selecting detector).

  2. Weak Decay of Hypernuclei

    CERN Document Server

    Alberico, W M

    2004-01-01

    The focus of these Lectures is on the weak decay modes of hypernuclei, with special attention to Lambda-hypernuclei. The subject involves many fields of modern theoretical and experimental physics, from nuclear structure to the fundamental constituents of matter and their interactions. The various weak decay modes of Lambda-hypernuclei are described: the mesonic mode and the non-mesonic ones. The latter are the dominant decay channels of medium--heavy hypernuclei, where, on the contrary, the mesonic decay is disfavoured by Pauli blocking effect on the outgoing nucleon. In particular, one can distinguish between one-body and two-body induced decays. Theoretical models employed to evaluate the (partial and total) decay widths of hypernuclei are illustrated, and their results compared with existing experimental data. Open problems and recent achievements are extensively discussed, in particular the determination of the ratio Gamma_n/Gamma_p, possible tests of the Delta I=1/2 rule in non-mesonic decays and the pu...

  3. The radioisotope complex project “RIC-80” at the Petersburg Nuclear Physics Institute

    Energy Technology Data Exchange (ETDEWEB)

    Panteleev, V. N., E-mail: vnp@pnpi.spb.ru; Barzakh, A. E.; Batist, L. Kh.; Fedorov, D. V.; Ivanov, V. S.; Moroz, F. V.; Molkanov, P. L.; Orlov, S. Yu.; Volkov, Yu. M. [NRC “Kurchatov Institute” PNPI, 188300 Gatchina (Russian Federation)

    2015-12-15

    The high current cyclotron C-80 capable of producing 40-80 MeV proton beams with a current of up to 200 μA has been constructed at Petersburg Nuclear Physics Institute. One of the main goals of the C-80 is the production of a wide spectrum of medical radionuclides for diagnostics and therapy. The project development of the radioisotope complex RIC-80 (radioisotopes at the cyclotron C-80) at the beam of C-80 has been completed. The RIC-80 complex is briefly discussed in this paper. The combination of the mass-separator with the target-ion source device, available at one of the new target stations for on-line or semi on-line production of a high purity separated radioisotopes, is explored in greater detail. The results of target and ion source tests for a mass-separator method for the production of high purity radioisotopes {sup 82}Sr and {sup 223,224}Ra are also presented.

  4. Influenza virus targets the mRNA export machinery and the nuclear pore complex.

    Science.gov (United States)

    Satterly, Neal; Tsai, Pei-Ling; van Deursen, Jan; Nussenzveig, Daniel R; Wang, Yaming; Faria, Paula A; Levay, Agata; Levy, David E; Fontoura, Beatriz M A

    2007-02-01

    The NS1 protein of influenza A virus is a major virulence factor that is essential for pathogenesis. NS1 functions to impair innate and adaptive immunity by inhibiting host signal transduction and gene expression, but its mechanisms of action remain to be fully elucidated. We show here that NS1 forms an inhibitory complex with NXF1/TAP, p15/NXT, Rae1/mrnp41, and E1B-AP5, which are key constituents of the mRNA export machinery that interact with both mRNAs and nucleoporins to direct mRNAs through the nuclear pore complex. Increased levels of NXF1, p15, or Rae1 revert the mRNA export blockage induced by NS1. Furthermore, influenza virus down-regulates Nup98, a nucleoporin that is a docking site for mRNA export factors. Reduced expression of these mRNA export factors renders cells highly permissive to influenza virus replication, demonstrating that proper levels of key constituents of the mRNA export machinery protect against influenza virus replication. Because Nup98 and Rae1 are induced by interferons, down-regulation of this pathway is likely a viral strategy to promote viral replication. These findings demonstrate previously undescribed influenza-mediated viral-host interactions and provide insights into potential molecular therapies that may interfere with influenza infection.

  5. Vesicular glutamate transporter-immunoreactivities in the vestibular nuclear complex of rat

    Institute of Scientific and Technical Information of China (English)

    Jiao DENG; Fu-Xing ZHANG; You-Wang PANG; Jin-Lian LI; Yun-Qing LI

    2006-01-01

    Objective Aims to delineate the distribution profile of three isoforms of vesicular glutamate transporter (VGluT), viz. VGluT1~3, and their cellular localization within vestibular nuclear complex (VNC). Methods Brain sections from normal Sprague-Dawley rats were processed immunohistochemically for VGluT detection, employing avidinbiotinylated peroxidase complex method with 3-3'-diaminobenzidine (DAB) as chromogen. Results The whole VNC expressed all of the three transporters that were observed to be localized to the fiber endings. Compared with VGluT1 and VGluT3, VGluT2 demonstrated a relatively homogeneous distribution, with much higher density in VNC. VGluT3 displayed the highest density in lateral vestibular nucleus and group X, contrasting with the sparse immunostained puncta within vestibular medial and inferior nuclei. Conclusion Glutamtatergic pathways participate in the processing of vestibular signals within VNC mainly through the re-uptake of glutamate into synaptic vesicles by VGluT1 and 2, whereas VGluT3 may play a similar role mainly in areas other than medial and inferior nuclei of VNC.

  6. Ubiquitination of HTLV-I Tax in response to DNA damage regulates nuclear complex formation and nuclear export

    Directory of Open Access Journals (Sweden)

    Marriott Susan J

    2007-12-01

    Full Text Available Abstract Background The HTLV-I oncoprotein, Tax, is a pleiotropic protein whose activity is partially regulated by its ability to interact with, and perturb the functions of, numerous cellular proteins. Tax is predominantly a nuclear protein that localizes to nuclear foci known as Tax Speckled Structures (TSS. We recently reported that the localization of Tax and its interactions with cellular proteins are altered in response to various forms of genotoxic and cellular stress. The level of cytoplasmic Tax increases in response to stress and this relocalization depends upon the interaction of Tax with CRM1. Cellular pathways and signals that regulate the subcellular localization of Tax remain to be determined. However, post-translational modifications including sumoylation and ubiquitination are known to influence the subcellular localization of Tax and its interactions with cellular proteins. The sumoylated form of Tax exists predominantly in the nucleus while ubiquitinated Tax exists predominantly in the cytoplasm. Therefore, we hypothesized that post-translational modifications of Tax that occur in response to DNA damage regulate the localization of Tax and its interactions with cellular proteins. Results We found a significant increase in mono-ubiquitination of Tax in response to UV irradiation. Mutation of specific lysine residues (K280 and K284 within Tax inhibited DNA damage-induced ubiquitination. In contrast to wild-type Tax, which undergoes transient nucleocytoplasmic shuttling in response to DNA damage, the K280 and K284 mutants were retained in nuclear foci following UV irradiation and remained co-localized with the cellular TSS protein, sc35. Conclusion This study demonstrates that the localization of Tax, and its interactions with cellular proteins, are dynamic following DNA damage and depend on the post-translational modification status of Tax. Specifically, DNA damage induces the ubiquitination of Tax at K280 and K284

  7. HuR-Regulated mRNAs Associated with Nuclear hnRNP A1-RNP Complexes

    Directory of Open Access Journals (Sweden)

    Apostolia Guialis

    2013-10-01

    Full Text Available Post-transcriptional regulatory networks are dependent on the interplay of many RNA-binding proteins having a major role in mRNA processing events in mammals. We have been interested in the concerted action of the two RNA-binding proteins hnRNP A1 and HuR, both stable components of immunoselected hnRNP complexes and having a major nuclear localization. Specifically, we present here the application of the RNA-immunoprecipitation (RIP-Chip technology to identify a population of nuclear transcripts associated with hnRNP A1-RNPs as isolated from the nuclear extract of either HuR WT or HuR-depleted (KO mouse embryonic fibroblast (MEF cells. The outcome of this analysis was a list of target genes regulated via HuR for their association (either increased or reduced with the nuclear hnRNP A1-RNP complexes. Real time PCR analysis was applied to validate a selected number of nuclear mRNA transcripts, as well as to identify pre-spliced transcripts (in addition to their mature mRNA counterpart within the isolated nuclear hnRNP A1-RNPs. The differentially enriched mRNAs were found to belong to GO categories relevant to biological processes anticipated for hnRNP A1 and HuR (such as transport, transcription, translation, apoptosis and cell cycle indicating their concerted function in mRNA metabolism.

  8. Partial least-squares analysis of time decay data for Eu(III)-tetracycline complexes: simultaneous luminescent determination of tetracycline and oxytetracycline in bovine serum.

    Science.gov (United States)

    Ibañez, Gabriela A

    2008-05-30

    A simple and sensitive methodology to simultaneously quantify tetracycline and oxytetracycline in bovine serum samples is described. The method combines the advantages of the lanthanide-sensitized luminescence (i.e., sensitivity and selectivity) with partial least-squares (PLS) analysis, and requires no previous separation steps. Due to the strong overlapping of emission and excitation spectra of the analytes and their europium complexes, the luminescence decay curve (intensity of luminescence vs. time) of analyte-Eu complex was selected to resolve mixtures of tetracycline and oxytetracycline. Partial least-squares uses the luminescence decay as discriminatory parameter and regresses the luminescence versus time onto the concentrations of standards. Using a 16-sample aqueous calibration set, 10 validation samples, 11 spiked serum bovine samples and a blank of serum were studied. The analyte recoveries from serum samples ranged from 87 to 104% for tetracycline and from 94 to 106% for oxytetracycline. The results obtained by the developed method were statistically comparable to those obtained with high performance liquid chromatography.

  9. Aging in the vestibular nuclear complex of the male golden hamster (Mesocricetus auratus): anatomic and morphometric study.

    Science.gov (United States)

    Fernández, J A; Suárez, C; Navarro, A; Díaz, C; Alvarez, J C; González del Rey, C; Tolivia, J

    2007-08-01

    To study the effects of senescence on the vestibular nuclear complex twenty brainstems from male golden hamsters between 3 and 27 months-old were used and the possible variations in the number of neurons, neuronal morphology and nuclear volume were studied. The neuron profiles were drawn with a camera lucida and Abercrombie's method was used to estimate the total number of neurons. The test of Kolmogorov-Smirnov with the correction of Lilliefors was used to evaluate the fit of our data to a normal distribution and a regression analysis was done to decide if the variation of our data with age was statistically significant. The results of the present study are relevant only for male animals and the effect of senescence could be different in female vestibular nuclear complex. Aging affects the volume of the superior and lateral vestibular nuclei, as well as the nuclear neuronal diameter of the medial vestibular nucleus, but no significant neuronal loss has been appreciated in vestibular nuclear complex related with age. During the aging process we have observed that the distribution of neurons within the vestibular nuclei of the golden hamster does not show important changes and most of their morphometric parameters do not vary significantly.

  10. Dynamic mislocalizations of nuclear pore complex proteins after focal cerebral ischemia in rat.

    Science.gov (United States)

    Li, Qian; Ohta, Yasuyuki; Yamashita, Toru; Shang, Jingwei; Deguchi, Kentaro; Feng, Tian; Sato, Kota; Hishikawa, Nozomi; Nakano, Yumiko; Abe, Koji

    2017-09-01

    Nuclear pore complexes (NPCs) play an important role in coordinating the transport of proteins and nucleic acids between the nucleus and cytoplasm, and are therefore essential for maintaining normal cellular function and liability. In the present study, we investigated the temporal immunohistochemical distribution of five representative components of NPCs-Ran GTPase-activating protein 1 (RanGap1), glycoprotein-210 (Gp210), nucleoporin 205 (Nup205), nucleoporin 107 (Nup107), and nucleoporin 50 (Nup50)-after 90 min of transient middle cerebral artery occlusion (tMCAO) up to 28 days after the reperfusion in rat brains. Single immunohistochemical analyses showed ring-like stainings along the periphery of the nucleus in sham control brains. After tMCAO, Gp210 and Nup107 immunoreactivity continuously increased from 1 day, and RanGap1, Nup205, and Nup50 increased from 2 days until 28 days, which also displayed progressive precipitations within the nucleus in the peri-ischemic area, while the ischemic core showed scarce expression with collapsed structure. Double immunofluorescent analyses revealed nuclear retention and apparent colocalization of RanGap1 with Nup205, Gp210 with Nup205, and partial colocalization of Nup205 with Nup107; most of the ischemic changes above were similar to those observed in patients with C9orf72-genetic amyotrophic lateral sclerosis. Taken together, these observations suggest that the mislocalization of these nucleoporins may be a common pathogenesis of both ischemic and neurodegenerative disease. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  11. Cancer as a complex phenotype: pattern of cancer distribution within and beyond the nuclear family.

    Directory of Open Access Journals (Sweden)

    Laufey T Amundadottir

    2004-12-01

    Full Text Available BACKGROUND: The contribution of low-penetrant susceptibility variants to cancer is not clear. With the aim of searching for genetic factors that contribute to cancer at one or more sites in the body, we have analyzed familial aggregation of cancer in extended families based on all cancer cases diagnosed in Iceland over almost half a century. METHODS AND FINDINGS: We have estimated risk ratios (RRs of cancer for first- and up to fifth-degree relatives both within and between all types of cancers diagnosed in Iceland from 1955 to 2002 by linking patient information from the Icelandic Cancer Registry to an extensive genealogical database, containing all living Icelanders and most of their ancestors since the settlement of Iceland. We evaluated the significance of the familial clustering for each relationship separately, all relationships combined (first- to fifth-degree relatives and for close (first- and second-degree and distant (third- to fifth-degree relatives. Most cancer sites demonstrate a significantly increased RR for the same cancer, beyond the nuclear family. Significantly increased familial clustering between different cancer sites is also documented in both close and distant relatives. Some of these associations have been suggested previously but others not. CONCLUSION: We conclude that genetic factors are involved in the etiology of many cancers and that these factors are in some cases shared by different cancer sites. However, a significantly increased RR conferred upon mates of patients with cancer at some sites indicates that shared environment or nonrandom mating for certain risk factors also play a role in the familial clustering of cancer. Our results indicate that cancer is a complex, often non-site-specific disease for which increased risk extends beyond the nuclear family.

  12. Outsourcing the Nucleus: Nuclear Pore Complex Genes are no Longer Encoded in Nucleomorph Genomes

    Directory of Open Access Journals (Sweden)

    Nadja Neumann

    2006-01-01

    Full Text Available The nuclear pore complex (NPC facilitates transport between nucleus and cytoplasm. The protein constituents of the NPC, termed nucleoporins (Nups, are conserved across a wide diversity of eukaryotes. In apparent exception to this, no nucleoporin genes have been identified in nucleomorph genomes. Nucleomorphs, nuclear remnants of once free-living eukaryotes, took up residence as secondary endosymbionts in cryptomonad and chlorarachniophyte algae. As these genomes are highly reduced, Nup genes may have been lost, or relocated to the host nucleus. However, Nup genes are often poorly conserved between species, so absence may be an artifact of low sequence similarity. We therefore constructed an evolutionary bioinformatic screen to establish whether the apparent absence of Nup genes in nucleomorph genomes is due to genuine absence or the inability of current methods to detect homologues. We searched green plant (Arabidopsis and rice, green alga (Chlamydomonas reinhardtii and red alga (Cyanidioschyzon merolae genomes, plus two nucleomorph genomes (Bigelowiella natans and Guillardia theta with profile hidden Markov models (HMMs from curated alignments of known vertebrate/yeast Nups. Since the plant, algal and nucleomorph genomes all belong to the kingdom Plantae, and are evolutionarily distant from the outgroup (vertebrate/yeast training set, we use the plant and algal genomes as internal positive controls for the sensitivity of the searches in nucleomorph genomes. We fi nd numerous Nup homologues in all plant and free-living algal species, but none in either nucleomorph genome. BLAST searches using identified plant and algal Nups also failed to detect nucleomorph homologues. We conclude that nucleomorph Nup genes have either been lost, being replaced by host Nup genes, or, that nucleomorph Nup genes have been transferred to the host nucleus twice independently; once in the evolution of the red algal nucleomorph and once in the green algal nucleomorph.

  13. Nesprin-2G, a Component of the Nuclear LINC Complex, Is Subject to Myosin-Dependent Tension.

    Science.gov (United States)

    Arsenovic, Paul T; Ramachandran, Iswarya; Bathula, Kranthidhar; Zhu, Ruijun; Narang, Jiten D; Noll, Natalie A; Lemmon, Christopher A; Gundersen, Gregg G; Conway, Daniel E

    2016-01-01

    The nucleus of a cell has long been considered to be subject to mechanical force. Despite the observation that mechanical forces affect nuclear geometry and movement, how forces are applied onto the nucleus is not well understood. The nuclear LINC (linker of nucleoskeleton and cytoskeleton) complex has been hypothesized to be the critical structure that mediates the transfer of mechanical forces from the cytoskeleton onto the nucleus. Previously used techniques for studying nuclear forces have been unable to resolve forces across individual proteins, making it difficult to clearly establish if the LINC complex experiences mechanical load. To directly measure forces across the LINC complex, we generated a fluorescence resonance energy transfer-based tension biosensor for nesprin-2G, a key structural protein in the LINC complex, which physically links this complex to the actin cytoskeleton. Using this sensor we show that nesprin-2G is subject to mechanical tension in adherent fibroblasts, with highest levels of force on the apical and equatorial planes of the nucleus. We also show that the forces across nesprin-2G are dependent on actomyosin contractility and cell elongation. Additionally, nesprin-2G tension is reduced in fibroblasts from Hutchinson-Gilford progeria syndrome patients. This report provides the first, to our knowledge, direct evidence that nesprin-2G, and by extension the LINC complex, is subject to mechanical force. We also present evidence that nesprin-2G localization to the nuclear membrane is altered under high-force conditions. Because forces across the LINC complex are altered by a variety of different conditions, mechanical forces across the LINC complex, as well as the nucleus in general, may represent an important mechanism for mediating mechanotransduction.

  14. Dissociation of the dorsal-cactus complex and phosphorylation of the dorsal protein correlate with the nuclear localization of dorsal

    OpenAIRE

    1993-01-01

    The formation of dorsal-ventral polarity in Drosophila requires the asymmetric nuclear localization of the dorsal protein along the D/V axis. This process is regulated by the action of the dorsal group genes and cactus. We show that dorsal and cactus are both phosphoproteins that form a stable cytoplasmic complex, and that the cactus protein is stabilized by its interaction with dorsal. The dorsal-cactus complex dissociates when dorsal is targeted to the nucleus. While the phosphorylation of ...

  15. Search for $^{73}$Rb and Investigation of Nuclear Decay Modes Near the Z=N Line in the Border Region of the Astrophysical RP-Process Path

    CERN Multimedia

    2002-01-01

    % IS351 \\\\ \\\\ Following a test experiment on the production rates of $^{73}$Rb and $^{74}$Rb and the negative result concerning the existence of $^{73}$Rb, we have studied the mirror $\\beta$- decay of $^{71}$Kr and observed for the first time the $\\beta$- decay of $^{70}$Kr. The $\\beta$- decay study of $^{71}$Kr extends the systematics of mirror decays to an upper $fp$-shell. The observation of the $\\beta$- decay of $^{70}$Kr resulted in the first half-life measurement of this nucleus. Our result disagrees with the value used in the recent rp-process calculations. The new half-life value may increase the effective two proton capture rate of $^{68}$Se by a factor of 6.5.

  16. Structures of the autoproteolytic domain from the Saccharomyces cerevisiae nuclear pore complex component, Nup145

    Energy Technology Data Exchange (ETDEWEB)

    Sampathkumar, Parthasarathy; Ozyurt, Sinem A.; Do, Johnny; Bain, Kevin T.; Dickey, Mark; Rodgers, Logan A.; Gheyi, Tarun; Sali, Andrej; Kim, Seung Joong; Phillips, Jeremy; Pieper, Ursula; Fernandez-Martinez, Javier; Franke, Josef D.; Martel, Anne; Tsuruta, Hiro; Atwell, Shane; Thompson, Devon A.; Emtage, J. Spencer; Wasserman, Stephen R.; Rout, Michael P.; Sauder, J. Michael; Burley, Stephen K. (SLAC); (Rockefeller); (UCSF); (Lilly)

    2012-04-30

    Nuclear pore complexes (NPCs) are large, octagonally symmetric dynamic macromolecular assemblies responsible for exchange of proteins and RNAs between the nucleus and cytoplasm. NPCs are made up of at least 456 polypeptides from {approx}30 distinct nucleoporins. Several of these components, sharing similar structural motifs, form stable subcomplexes that form a coaxial structure containing two outer rings (the nuclear and cytoplasmic rings), two inner rings, and a membrane ring. The yeast (Saccharomyces cerevisiae) Nup145 and its human counterpart are unique among the nucleoporins, in that they undergo autoproteolysis to generate functionally distinct proteins. The human counterpart of Nup145 is expressed as two alternatively spliced mRNA transcripts. The larger 190 kDa precursor undergoes post-translational autoproteolysis at the Phe863-Ser864 peptide bond yielding the 92 kDa Nup98 and the 96 kDa Nup96. The smaller 98 kDa precursor is also autoproteolysed at an analogous site giving 92 kDa Nup98-N and a 6 kDa C-terminal fragment, which may form a noncovalent complex. The yeast Nup145 precursor [Fig. 1(A)] contains twelve repeats of a 'GLFG' peptide motif (FG repeats) at its N-terminus, an internal autoproteolytic domain (a region of high conservation with the homologous yeast nucleoporins Nup110 and Nup116, neither of which undergo autoproteolysis), followed by the C-terminal domain. Various forms of the FG repeats are present in nearly half of all nucleoporins; they form intrinsically disordered regions implicated in gating mechanisms that control passage of macromolecules through NPCs. Nup145 undergoes autoproteolysis at the Phe605-Ser606 peptide bond to generate two functionally distinct proteins, Nup145N and Nup145C. Subsequently, Nup145C associates with six other proteins to form the heptameric Y-complex, a component of the outer rings of the NPC. Nup145N, on the other hand, can shuttle between the NPC and the nuclear interior. It has been suggested

  17. Nuclear export of the influenza virus ribonucleoprotein complex: Interaction of Hsc70 with viral proteins M1 and NS2.

    Science.gov (United States)

    Watanabe, Ken; Shimizu, Teppei; Noda, Saiko; Tsukahara, Fujiko; Maru, Yoshiro; Kobayashi, Nobuyuki

    2014-01-01

    The influenza virus replicates in the host cell nucleus, and the progeny viral ribonucleoprotein complex (vRNP) is exported to the cytoplasm prior to maturation. NS2 has a nuclear export signal that mediates the nuclear export of vRNP by the vRNP-M1-NS2 complex. We previously reported that the heat shock cognate 70 (Hsc70) protein binds to M1 protein and mediates vRNP export. However, the interactions among M1, NS2, and Hsc70 are poorly understood. In the present study, we demonstrate that Hsc70 interacts with M1 more strongly than with NS2 and competes with NS2 for M1 binding, suggesting an important role of Hsc70 in the nuclear export of vRNP.

  18. A quantitative 14-3-3 interaction screen connects the nuclear exosome targeting complex to the DNA damage response

    DEFF Research Database (Denmark)

    Blasius, Melanie; Wagner, Sebastian A; Choudhary, Chuna Ram

    2014-01-01

    RNA metabolism is altered following DNA damage, but the underlying mechanisms are not well understood. Through a 14-3-3 interaction screen for DNA damage-induced protein interactions in human cells, we identified protein complexes connected to RNA biology. These include the nuclear exosome...

  19. Column: Factors Affecting Data Decay

    Directory of Open Access Journals (Sweden)

    Kevin Fairbanks

    2012-06-01

    Full Text Available In nuclear physics, the phrase decay rate is used to denote the rate that atoms and other particles spontaneously decompose. Uranium-235 famously decays into a variety of daughter isotopes including Thorium and Neptunium, which themselves decay to others. Decay rates are widely observed and wildly different depending on many factors, both internal and external. U-235 has a half-life of 703,800,000 years, for example, while free neutrons have a half-life of 611 seconds and neutrons in an atomic nucleus are stable.We posit that data in computer systems also experiences some kind of statistical decay process and thus also has a discernible decay rate. Like atomic decay, data decay fluctuates wildly. But unlike atomic decay, data decay rates are the result of so many different interplaying processes that we currently do not understand them well enough to come up with quantifiable numbers. Nevertheless, we believe that it is useful to discuss some of the factors that impact the data decay rate, for these factors frequently determine whether useful data about a subject can be recovered by forensic investigation.(see PDF for full column

  20. Primary retention following nuclear recoil in β-decay: Proposed synthesis of a metastable rare gas oxide ((38)ArO4) from ((38)ClO4(-)) and the evolution of chemical bonding over the nuclear transmutation reaction path.

    Science.gov (United States)

    Timm, Matthew J; Matta, Chérif F

    2014-12-01

    Argon tetroxide (ArO4) is the last member of the N=50 e(-) isoelectronic and isosteric series of ions: SiO4(4-), PO4(3-), SO4(2-), and ClO4(-). A high level computational study demonstrated that while ArO4 is kinetically stable it has a considerable positive enthalpy of formation (of ~298kcal/mol) (Lindh et al., 1999. J. Phys. Chem. A 103, pp. 8295-8302) confirming earlier predictions by Pyykkö (1990. Phys. Scr. 33, pp. 52-53). ArO4 can be expected to be difficult to synthesize by traditional chemistry due to its metastability and has not yet been synthesized at the time of writing. A computational investigation of the changes in the chemical bonding of chlorate (ClO4(-)) when the central chlorine atom undergoes a nuclear transmutation from the unstable artificial chlorine isotope (38)Cl to the stable rare argon isotope (38)Ar through β-decay, hence potentially leading to the formation of ArO4, is reported. A mathematical model is presented that allows for the prediction of yields following the recoil of a nucleus upon ejecting a β-electron. It is demonstrated that below a critical angle between the ejected β-electron and that of the accompanying antineutrino their respective linear momentums can cancel to such an extent as imparting a recoil to the daughter atom insufficient for breaking the Ar-O bond. As a result, a primary retention yield of ~1% of ArO4 is predicted following the nuclear disintegration. The study is conducted at the quadratic configuration interaction with single and double excitations [QCISD/6-311+G(3df)] level of theory followed by an analysis of the electron density by the quantum theory of atoms in molecules (QTAIM). Crossed potential energy surfaces (PES) were used to construct a PES from the metastable ArO4 ground singlet state to the Ar-O bond dissociation product ArO3+O((3)P) from which the predicted barrier to dissociation is ca. 22kcal/mol and the exothermic reaction energy is ca. 28kcal/mol [(U)MP2/6-311+G(d)]. Copyright © 2014

  1. Examination of cucurbit[7]uril and its host-guest complexes by diffusion nuclear magnetic resonance.

    Science.gov (United States)

    Wheate, Nial J; Kumar, P G Anil; Torres, Allan M; Aldrich-Wright, Janice R; Price, William S

    2008-02-28

    The self-diffusion of cucurbit[7]uril (CB[7]) and its host-guest complexes in D2O has been examined using pulsed gradient spin-echo nuclear magnetic resonance spectroscopy. CB[7] diffuses freely at a concentration of 2 mM with a diffusion coefficient (D) of 3.07 x 10(-10) m(2) s(-1). At saturation (3.7 mM), CB[7] diffuses more slowly (D = 2.82 x 10(-10) m(2) s(-1)) indicating that it partially self-associates. At concentrations between 2 and 200 mM, CsCl has no effect on the diffusion coefficient of CB[7] (1 mM). Conversely, CB[7] (2 mM) significantly affects the diffusion of 133Cs+ (1 mM), decreasing its diffusion coefficient from 1.86 to 0.83 x 10(-9) m(2) s(-1). Similar changes in the rate of diffusion of other alkali earth metal cations are observed upon the addition of CB[7]. The diffusion coefficient of 23Na+ changes from 1.26 to 0.90 x 10(-9) m(2) s(-1) and 7Li+ changes from 3.40 to 3.07 x 10(-9) m(2) s(-1). In most cases, encapsulation of a variety of inorganic and organic guests within CB[7] decreases their rates of diffusion in D2O. For instance, the diffusion coefficient of the dinuclear platinum complex trans-[[PtCl(NH3)2}2mu-dpzm](2+) (where dpzm is 4,4'-dipyrazolylmethane) decreases from 4.88 to 2.95 x 10(-10) m(2) s(-1) upon encapsulation with an equimolar concentration of CB[7].

  2. Bicaudal D2, dynein, and kinesin-1 associate with nuclear pore complexes and regulate centrosome and nuclear positioning during mitotic entry.

    Directory of Open Access Journals (Sweden)

    Daniël Splinter

    Full Text Available BICD2 is one of the two mammalian homologues of the Drosophila Bicaudal D, an evolutionarily conserved adaptor between microtubule motors and their cargo that was previously shown to link vesicles and mRNP complexes to the dynein motor. Here, we identified a G2-specific role for BICD2 in the relative positioning of the nucleus and centrosomes in dividing cells. By combining mass spectrometry, biochemical and cell biological approaches, we show that the nuclear pore complex (NPC component RanBP2 directly binds to BICD2 and recruits it to NPCs specifically in G2 phase of the cell cycle. BICD2, in turn, recruits dynein-dynactin to NPCs and as such is needed to keep centrosomes closely tethered to the nucleus prior to mitotic entry. When dynein function is suppressed by RNA interference-mediated depletion or antibody microinjection, centrosomes and nuclei are actively pushed apart in late G2 and we show that this is due to the action of kinesin-1. Surprisingly, depletion of BICD2 inhibits both dynein and kinesin-1-dependent movements of the nucleus and cytoplasmic NPCs, demonstrating that BICD2 is needed not only for the dynein function at the nuclear pores but also for the antagonistic activity of kinesin-1. Our study demonstrates that the nucleus is subject to opposing activities of dynein and kinesin-1 motors and that BICD2 contributes to nuclear and centrosomal positioning prior to mitotic entry through regulation of both dynein and kinesin-1.

  3. Mitotic nuclear pore complex segregation involves Nup2 in Aspergillus nidulans.

    Science.gov (United States)

    Suresh, Subbulakshmi; Markossian, Sarine; Osmani, Aysha H; Osmani, Stephen A

    2017-09-04

    Transport through nuclear pore complexes (NPCs) during interphase is facilitated by the nucleoporin Nup2 via its importin α- and Ran-binding domains. However, Aspergillus nidulans and vertebrate Nup2 also locate to chromatin during mitosis, suggestive of mitotic functions. In this study, we report that Nup2 is required for mitotic NPC inheritance in A. nidulans Interestingly, the role of Nup2 during mitotic NPC segregation is independent of its importin α- and Ran-binding domains but relies on a central targeting domain that is necessary for localization and viability. To test whether mitotic chromatin-associated Nup2 might function to bridge NPCs with chromatin during segregation, we provided an artificial link between NPCs and chromatin via Nup133 and histone H1. Using this approach, we bypassed the requirement of Nup2 for NPC segregation. This indicates that A. nidulans cells ensure accurate mitotic NPC segregation to daughter nuclei by linking mitotic DNA and NPC segregation via the mitotic specific chromatin association of Nup2. © 2017 Suresh et al.

  4. Slide-and-exchange mechanism for rapid and selective transport through the nuclear pore complex

    Science.gov (United States)

    Raveh, Barak; Karp, Jerome M.; Sparks, Samuel; Rout, Michael P.; Sali, Andrej; Cowburn, David

    2016-01-01

    Nucleocytoplasmic transport is mediated by the interaction of transport factors (TFs) with disordered phenylalanine-glycine (FG) repeats that fill the central channel of the nuclear pore complex (NPC). However, the mechanism by which TFs rapidly diffuse through multiple FG repeats without compromising NPC selectivity is not yet fully understood. In this study, we build on our recent NMR investigations showing that FG repeats are highly dynamic, flexible, and rapidly exchanging among TF interaction sites. We use unbiased long timescale all-atom simulations on the Anton supercomputer, combined with extensive enhanced sampling simulations and NMR experiments, to characterize the thermodynamic and kinetic properties of FG repeats and their interaction with a model transport factor. Both the simulations and experimental data indicate that FG repeats are highly dynamic random coils, lack intrachain interactions, and exhibit significant entropically driven resistance to spatial confinement. We show that the FG motifs reversibly slide in and out of multiple TF interaction sites, transitioning rapidly between a strongly interacting state and a weakly interacting state, rather than undergoing a much slower transition between strongly interacting and completely noninteracting (unbound) states. In the weakly interacting state, FG motifs can be more easily displaced by other competing FG motifs, providing a simple mechanism for rapid exchange of TF/FG motif contacts during transport. This slide-and-exchange mechanism highlights the direct role of the disorder within FG repeats in nucleocytoplasmic transport, and resolves the apparent conflict between the selectivity and speed of transport. PMID:27091992

  5. NUCLEAR GENE MUTATIONS AS THE CAUSE OF MITOCHONDRIAL COMPLEX III DEFICIENCY

    Directory of Open Access Journals (Sweden)

    Erika eFernandez-Vizarra

    2015-04-01

    Full Text Available Complex III (CIII deficiency is one of the least common oxidative phosphorylation defects associated to mitochondrial disease. CIII constitutes the center of the mitochondrial respiratory chain, as well as a crossroad for several other metabolic pathways. For more than ten years, of all the potential candidate genes encoding structural subunits and assembly factors, only three were known to be associated to CIII defects in human pathology. Thus, leaving many of these cases unresolved. These first identified genes were MT-CYB, the only CIII subunit encoded in the mitochondrial DNA; BCS1L, encoding an assembly factor, and UQCRB, a nuclear-encoded structural subunit. Nowadays, thanks to the fast progress that has taken place in the last three-four years, pathological changes in seven more genes are known to be associated to these conditions. This review will focus on the strategies that have permitted the latest discovery of mutations in factors that are necessary for a correct CIII assembly and activity, in relation with their function. In addition, new data further establishing the molecular role of LYRM7/MZM1L as a chaperone involved in CIII biogenesis are provided.

  6. Mitochondrial and nuclear DNA phylogenies reveal a complex evolutionary history in the Australasian robins (Passeriformes: Petroicidae).

    Science.gov (United States)

    Christidis, Les; Irestedt, Martin; Rowe, Dianne; Boles, Walter E; Norman, Janette A

    2011-12-01

    The Australasian robins (Petroicidae) comprise a relatively homogeneous group of small to medium-sized insectivorous birds. Their center of diversity is Australia and New Guinea (40 species) but seven species have managed to colonize geographically distant islands such as Tanimbar, New Britain, New Zealand, New Caledonia, Norfolk Island, Vanuatu, Solomon Islands, Fiji and Samoa. To resolve the evolutionary relationships within the Petroicidae, we here present the results of a phylogenetic analysis of sequence data from two mitochondrial genes (ND2, CO1) and one nuclear intron (β-Fibrinogen intron 5) for all 14 genera and 40 of the 46 currently recognized species. All phylogenetic analyses identified six primary lineages, treated here as subfamilies, within the Petroicidae: (1) Eopsaltriinae comprising Eopsaltria (excluding E. flaviventris), Tregellasia, Peneothello, Melanodryas, Poecilodryas and Heteromyias; (2) Drymodinae comprising Drymodes; (3) Microecinae comprising Microeca, Monachella and Eopsaltria flaviventris; (4) Petroicinae comprising Petroica and Eugerygone; (5) Pachycephalopsinae comprising Pachycephalopsis; and (6) Amalocichlinae comprising Amalocichla. The genera Eopsaltria, Microeca, Peneothello and Poecilodryas were found to be paraphyletic. Based on assessments of phylogenetic branching patterns and/or DNA divergence it also was apparent that Eopsaltriaaustralis, Tregellasialeucops, Melanodryascucullata, Heteromyiasalbispecularis, Drymodessupercilious and Microecaflavigaster may each comprise more than one species. The Petroicidae display a complex biogeographical history involving repeated radiations both within, and across Australia and New Guinea. It appears that dispersal into smaller islands such as New Britain, Tanimbar and the South Pacific has only been undertaken by species with a "flycatcher" body form.

  7. Employing Forbidden Transitions as Qubits in a Nuclear Spin-Free Chromium Complex.

    Science.gov (United States)

    Fataftah, Majed S; Zadrozny, Joseph M; Coste, Scott C; Graham, Michael J; Rogers, Dylan M; Freedman, Danna E

    2016-02-01

    The implementation of quantum computation (QC) would revolutionize scientific fields ranging from encryption to quantum simulation. One intuitive candidate for the smallest unit of a quantum computer, a qubit, is electronic spin. A prominent proposal for QC relies on high-spin magnetic molecules, where multiple transitions between the many MS levels are employed as qubits. Yet, over a decade after the original notion, the exploitation of multiple transitions within a single manifold for QC remains unrealized in these high-spin species due to the challenge of accessing forbidden transitions. To create a proof-of-concept system, we synthesized the novel nuclear spin-free complex [Cr(C3S5)3](3-) with precisely tuned zero-field splitting parameters that create two spectroscopically addressable transitions, with one being a forbidden transition. Pulsed electron paramagnetic resonance (EPR) measurements enabled the investigation of the coherent lifetimes (T2) and quantum control (Rabi oscillations) for two transitions, one allowed and one forbidden, within the S = (3)/2 spin manifold. This investigation represents a step forward in the development of high-spin species as a pathway to scalable QC systems within magnetic molecules.

  8. Development of InP solid state detector and liquid scintillator containing metal complex for measurement of pp/7Be solar neutrinos and neutrinoless double beta decay

    Science.gov (United States)

    Fukuda, Yoshiyuki; Moriyama, Shigetaka

    2012-07-01

    A large volume solid state detector using a semi-insulating Indium Phosphide (InP) wafer have been developed for measurement of pp/7Be solar neutrinos. Basic performance such as the charge collection efficiency and the energy resolution were measured by 60% and 20%, respectively. In order to detect two gammas (115keV and 497keV) from neutrino capture, we have designed hybrid detector which consist InP detector and liquid xenon scintillator for IPNOS experiment. New InP detector with thin electrode (Cr 50Å- Au 50Å). For another possibility, an organic liquid scintillator containing indium complex and zirconium complex were studied for a measurement of low energy solar neutrinos and neutrinosless double beta decay, respectively. Benzonitrile was chosen as a solvent because of good solubility for the quinolinolato complexes (2 wt%) and of good light yield for the scintillation induced by gamma-ray irradiation. The photo-luminescence emission spectra of InQ3 and ZrQ4 in benzonitrile was measured and liquid scintillator cocktail using InQ3 and ZrQ4 (50mg) in benzonitrile solutions (20 mL) with secondary scintillators with PPO (100mg) and POPOP (10mg) was made. The energy spectra of incident gammas were measured, and they are first results of the gamma-ray energy spectra using luminescent of metal complexes.

  9. Insight into structure and assembly of the nuclear pore complex by utilizing the genome of a eukaryotic thermophile

    DEFF Research Database (Denmark)

    Amlacher, Stefan; Sarges, Phillip; Flemming, Dirk;

    2011-01-01

    Despite decades of research, the structure and assembly of the nuclear pore complex (NPC), which is composed of ~30 nucleoporins (Nups), remain elusive. Here, we report the genome of the thermophilic fungus Chaetomium thermophilum (ct) and identify the complete repertoire of Nups therein. The the......Despite decades of research, the structure and assembly of the nuclear pore complex (NPC), which is composed of ~30 nucleoporins (Nups), remain elusive. Here, we report the genome of the thermophilic fungus Chaetomium thermophilum (ct) and identify the complete repertoire of Nups therein....... The thermophilic proteins show improved properties for structural and biochemical studies compared to their mesophilic counterparts, and purified ctNups enabled the reconstitution of the inner pore ring module that spans the width of the NPC from the anchoring membrane to the central transport channel. This module...... of a thermophilic eukaryote for studying complex molecular machines....

  10. The GIP gamma-tubulin complex-associated proteins are involved in nuclear architecture in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Morgane eBatzenschlager

    2013-11-01

    Full Text Available During interphase, the microtubular cytoskeleton of cycling plant cells is organized in both cortical and perinuclear arrays. Perinuclear microtubules (MTs are nucleated from γ-Tubulin Complexes (γ-TuCs located at the surface of the nucleus. The molecular mechanisms of γ-TuC association to the nuclear envelope are currently unknown. The γ-TuC Protein 3 (GCP3-Interacting Protein 1 (GIP1 is the smallest γ-TuC component identified so far. AtGIP1 and its homologous protein AtGIP2 participate in the localization of active γ-TuCs at interphasic and mitotic MT nucleation sites. Arabidopsis gip1gip2 mutants are impaired in establishing a fully functional mitotic spindle and exhibit severe developmental defects.In this study, gip1gip2 knock down mutants were further characterized at the cellular level. In addition to defects in both the localization of γ-TuC core proteins and MT fibre robustness, gip1gip2 mutants exhibited a severe alteration of the nuclear shape associated with an abnormal distribution of the nuclear pore complexes. Simultaneously, they showed a misorganization of the inner nuclear membrane protein AtSUN1. Furthermore, AtGIP1 was identified as an interacting partner of AtTSA1 which was detected, like the AtGIP proteins, at the nuclear envelope.These results provide the first evidence for the involvement of a γ-TuC component in both nuclear shaping and nuclear envelope organization. Functional hypotheses are discussed in order to propose a model for a GIP-dependent nucleo-cytoplasmic continuum.

  11. Nuclear trafficking of the HIV-1 pre-integration complex depends on the ADAM10 intracellular domain

    Energy Technology Data Exchange (ETDEWEB)

    Endsley, Mark A., E-mail: maendsle@utmb.edu [Department Internal Medicine, Division of Infectious Diseases, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555 (United States); Somasunderam, Anoma D., E-mail: asomasun@utmb.edu [Department Internal Medicine, Division of Infectious Diseases, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555 (United States); Li, Guangyu, E-mail: LIG001@mail.etsu.edu [Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614 (United States); Oezguen, Numan, E-mail: numan.oezguen@bcm.edu [Department of Pathology and Immunology, Microbiome Center, Texas Children' s Hospital, Houston, TX 77030 (United States); Thiviyanathan, Varatharasa, E-mail: Varatharasa.Thiviyanathan@uth.tmc.edu [Institute of Molecular Medicine, University of Texas Health Science Center, Houston, TX 77030 (United States); Murray, James L., E-mail: jmurray100@yahoo.com [GeneTAG Technology, Inc., 3155 Northwoods Place, Norcross, GA 30071 (United States); Rubin, Donald H., E-mail: don.h.rubin@vanderbilt.edu [Research Medicine, VA Tennessee Valley Healthcare System, 1310 24th Ave. South, Nashville, TN 37212 (United States); Departments of Medicine, Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, 1161 21st Ave South, Nashville, TN 37232 (United States); Hodge, Thomas W., E-mail: twhodge3@gmail.com [Pre-clinical and Antiviral Research, Tamir Biotechnology, Inc., 12625 High Bluff Dr., Suite 113, San Diego, CA 92130 (United States); and others

    2014-04-15

    Previously, we showed that ADAM10 is necessary for HIV-1 replication in primary human macrophages and immortalized cell lines. Silencing ADAM10 expression interrupted the HIV-1 life cycle prior to nuclear translocation of viral cDNA. Furthermore, our data indicated that HIV-1 replication depends on the expression of ADAM15 and γ-secretase, which proteolytically processes ADAM10. Silencing ADAM15 or γ-secretase expression inhibits HIV-1 replication between reverse transcription and nuclear entry. Here, we show that ADAM10 expression also supports replication in CD4{sup +} T lymphocytes. The intracellular domain (ICD) of ADAM10 associates with the HIV-1 pre-integration complex (PIC) in the cytoplasm and immunoprecipitates and co-localizes with HIV-1 integrase, a key component of PIC. Taken together, our data support a model whereby ADAM15/γ-secretase processing of ADAM10 releases the ICD, which then incorporates into HIV-1 PIC to facilitate nuclear trafficking. Thus, these studies suggest ADAM10 as a novel therapeutic target for inhibiting HIV-1 prior to nuclear entry. - Highlights: • Nuclear trafficking of the HIV-1 pre-integration complex depends on ADAM10. • ADAM10 associates with HIV-1 integrase in the pre-integration complex. • HIV-1 replication depends on the expression of ADAM15 and γ-secretase. • Silencing ADAM15 or γ-secretase expression inhibits nuclear import of viral cDNA. • ADAM10 is important for HIV-1 replication in human macrophages and CD4{sup +} T lymphocytes.

  12. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... its earliest stages as well as a patient’s immediate response to therapeutic interventions. Children's (pediatric) nuclear medicine ... leaving the nuclear medicine facility. Through the natural process of radioactive decay, the small amount of radiotracer ...

  13. Nuclear Power in Space

    Science.gov (United States)

    1994-01-01

    In the early years of the United States space program, lightweight batteries, fuel cells, and solar modules provided electric power for space missions. As missions became more ambitious and complex, power needs increased and scientists investigated various options to meet these challenging power requirements. One of the options was nuclear energy. By the mid-1950s, research had begun in earnest on ways to use nuclear power in space. These efforts resulted in the first radioisotope thermoelectric generators (RTGs), which are nuclear power generators build specifically for space and special terrestrial uses. These RTGs convert the heat generated from the natural decay of their radioactive fuel into electricity. RTGs have powered many spacecraft used for exploring the outer planets of the solar system and orbiting the sun and Earth. They have also landed on Mars and the moon. They provide the power that enables us to see and learn about even the farthermost objects in our solar system.

  14. Nuclear wave function effect in nonmesonic decay of the hypernucleus sup 4 subLAMBDA He via the one-pion exchange model

    CERN Document Server

    Jun, J H

    1999-01-01

    In the nonmesonic weak decay of the hypernucleus sup 4 subLAMBDA He via the one-pion exchange model, the fact that the wave functions of the nucleons in the initial hypernucleus sup 4 subLAMBDA He which do not take part in the decay process are neither orthogonal to nor the same as the wave functions of the slowly moving unbound residual nucleons is taken into account. The result shows that for the decay channels sup 4 subLAMBDA He -> (2p) sub S sub L sub O sub W + n + n and sup 4 subLAMBDA He -> (2p) sub S sub L sub O sub W + p + n, the decay rates are reduced to approx 20 %.

  15. Imaging analysis of nuclear antiviral factors through direct detection of incoming adenovirus genome complexes

    Energy Technology Data Exchange (ETDEWEB)

    Komatsu, Tetsuro [Microbiologie Fondamentale et Pathogénicité, MFP CNRS UMR 5234, Université de Bordeaux, Bordeaux 33076 (France); Department of Infection Biology, Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575 (Japan); Will, Hans [Department of Tumor Biology, University Hospital Hamburg-Eppendorf, 20246 Hamburg (Germany); Nagata, Kyosuke [Department of Infection Biology, Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575 (Japan); Wodrich, Harald, E-mail: harald.wodrich@u-bordeaux.fr [Microbiologie Fondamentale et Pathogénicité, MFP CNRS UMR 5234, Université de Bordeaux, Bordeaux 33076 (France)

    2016-04-22

    Recent studies involving several viral systems have highlighted the importance of cellular intrinsic defense mechanisms through nuclear antiviral proteins that restrict viral propagation. These factors include among others components of PML nuclear bodies, the nuclear DNA sensor IFI16, and a potential restriction factor PHF13/SPOC1. For several nuclear replicating DNA viruses, it was shown that these factors sense and target viral genomes immediately upon nuclear import. In contrast to the anticipated view, we recently found that incoming adenoviral genomes are not targeted by PML nuclear bodies. Here we further explored cellular responses against adenoviral infection by focusing on specific conditions as well as additional nuclear antiviral factors. In line with our previous findings, we show that neither interferon treatment nor the use of specific isoforms of PML nuclear body components results in co-localization between incoming adenoviral genomes and the subnuclear domains. Furthermore, our imaging analyses indicated that neither IFI16 nor PHF13/SPOC1 are likely to target incoming adenoviral genomes. Thus our findings suggest that incoming adenoviral genomes may be able to escape from a large repertoire of nuclear antiviral mechanisms, providing a rationale for the efficient initiation of lytic replication cycle. - Highlights: • Host nuclear antiviral factors were analyzed upon adenovirus genome delivery. • Interferon treatments fail to permit PML nuclear bodies to target adenoviral genomes. • Neither Sp100A nor B targets adenoviral genomes despite potentially opposite roles. • The nuclear DNA sensor IFI16 does not target incoming adenoviral genomes. • PHF13/SPOC1 targets neither incoming adenoviral genomes nor genome-bound protein VII.

  16. Imaging analysis of nuclear antiviral factors through direct detection of incoming adenovirus genome complexes.

    Science.gov (United States)

    Komatsu, Tetsuro; Will, Hans; Nagata, Kyosuke; Wodrich, Harald

    2016-04-22

    Recent studies involving several viral systems have highlighted the importance of cellular intrinsic defense mechanisms through nuclear antiviral proteins that restrict viral propagation. These factors include among others components of PML nuclear bodies, the nuclear DNA sensor IFI16, and a potential restriction factor PHF13/SPOC1. For several nuclear replicating DNA viruses, it was shown that these factors sense and target viral genomes immediately upon nuclear import. In contrast to the anticipated view, we recently found that incoming adenoviral genomes are not targeted by PML nuclear bodies. Here we further explored cellular responses against adenoviral infection by focusing on specific conditions as well as additional nuclear antiviral factors. In line with our previous findings, we show that neither interferon treatment nor the use of specific isoforms of PML nuclear body components results in co-localization between incoming adenoviral genomes and the subnuclear domains. Furthermore, our imaging analyses indicated that neither IFI16 nor PHF13/SPOC1 are likely to target incoming adenoviral genomes. Thus our findings suggest that incoming adenoviral genomes may be able to escape from a large repertoire of nuclear antiviral mechanisms, providing a rationale for the efficient initiation of lytic replication cycle.

  17. Identification of low molecular weight nuclear complexes containing integrase during the early stages of HIV-1 infection.

    Science.gov (United States)

    Gérard, Annabelle; Soler, Nicolas; Ségéral, Emmanuel; Belshan, Michael; Emiliani, Stéphane

    2013-02-01

    HIV-1 replication requires integration of its reverse transcribed viral cDNA into a host cell chromosome. The DNA cutting and joining reactions associated to this key step are catalyzed by the viral protein integrase (IN). In infected cells, IN binds the viral cDNA, together with viral and cellular proteins, to form large nucleoprotein complexes. However, the dynamics of IN complexes formation is still poorly understood. Here, we characterized IN complexes during the early stages of T-lymphocyte infection. We found that following viral entry into the host cell, IN was rapidly targeted to proteasome-mediated degradation. Interactions between IN and cellular cofactors LEDGF/p75 and TNPO3 were detected as early as 6 h post-infection. Size exclusion chromatography of infected cell extracts revealed distinct IN complexes in vivo. While at 2 h post-infection the majority of IN eluted within a high molecular weight complex competent for integration (IN complex I), IN was also detected in a low molecular weight complex devoid of full-length viral cDNA (IN complex II, ~440 KDa). At 6 h post-infection the relative proportion of IN complex II increased. Inhibition of reverse transcription or integration did not alter the elution profile of IN complex II in infected cells. However, in cells depleted for LEDGF/p75 IN complex II shifted to a lower molecular weight complex (IN complex III, ~150 KDa) containing multimers of IN. Notably, cell fractionation experiments indicated that both IN complex II and III were exclusively nuclear. Finally, IN complex II was not detected in cells infected with a virus harboring a mutated IN defective for LEDGF/p75 interaction and tetramerization. Our findings indicate that, shortly after viral entry, a significant portion of DNA-free IN that is distinct from active pre-integration complexes accumulates in the nucleus.

  18. Identification of low molecular weight nuclear complexes containing integrase during the early stages of HIV-1 infection

    Directory of Open Access Journals (Sweden)

    Gérard Annabelle

    2013-02-01

    Full Text Available Abstract Background HIV-1 replication requires integration of its reverse transcribed viral cDNA into a host cell chromosome. The DNA cutting and joining reactions associated to this key step are catalyzed by the viral protein integrase (IN. In infected cells, IN binds the viral cDNA, together with viral and cellular proteins, to form large nucleoprotein complexes. However, the dynamics of IN complexes formation is still poorly understood. Results Here, we characterized IN complexes during the early stages of T-lymphocyte infection. We found that following viral entry into the host cell, IN was rapidly targeted to proteasome-mediated degradation. Interactions between IN and cellular cofactors LEDGF/p75 and TNPO3 were detected as early as 6 h post-infection. Size exclusion chromatography of infected cell extracts revealed distinct IN complexes in vivo. While at 2 h post-infection the majority of IN eluted within a high molecular weight complex competent for integration (IN complex I, IN was also detected in a low molecular weight complex devoid of full-length viral cDNA (IN complex II, ~440 KDa. At 6 h post-infection the relative proportion of IN complex II increased. Inhibition of reverse transcription or integration did not alter the elution profile of IN complex II in infected cells. However, in cells depleted for LEDGF/p75 IN complex II shifted to a lower molecular weight complex (IN complex III, ~150 KDa containing multimers of IN. Notably, cell fractionation experiments indicated that both IN complex II and III were exclusively nuclear. Finally, IN complex II was not detected in cells infected with a virus harboring a mutated IN defective for LEDGF/p75 interaction and tetramerization. Conclusions Our findings indicate that, shortly after viral entry, a significant portion of DNA–free IN that is distinct from active pre-integration complexes accumulates in the nucleus.

  19. Beta and muon decays

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, A.; Pascual, P.

    1967-07-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  20. First and last ancestors: reconstructing evolution of the endomembrane system with ESCRTs, vesicle coat proteins, and nuclear pore complexes.

    Science.gov (United States)

    Field, Mark C; Dacks, Joel B

    2009-02-01

    The eukaryotic endomembrane system is responsible for the biosynthesis and transport of proteins and lipids, and for the definition of the major subcellular compartments. Recent work indicates that the endomembrane system is ancient, with near modern complexity predating the radiation of the major eukaryotic lineages. The challenge is to look beyond the last eukaryotic common ancestor and to attempt to deduce the evolutionary steps in the rise of membrane-trafficking complexity. Relationships between the endomembrane coatomer complexes and their evolutionary connection to the nuclear pore complex are emerging. These studies, plus the realization of a role for the ESCRT complex as an alternate, but equally ancient, system for membrane deformation are providing insight into the earliest stages of endomembrane evolution.

  1. Conservation laws, radiative decay rates, and excited state localization in organometallic complexes with strong spin-orbit coupling

    CERN Document Server

    Powell, B J

    2015-01-01

    There is longstanding fundamental interest in 6-fold coordinated $d^6$ ($t_{2g}^6$) transition metal complexes such as [Ru(bpy)$_3$]$^{2+}$ and Ir(ppy)$_3$, particularly their phosphorescence. This interest has increased with the growing realisation that many of these complexes have potential uses in applications including photovoltaics, imaging, sensing, and light-emitting diodes. In order to design new complexes with properties tailored for specific applications a detailed understanding of the low-energy excited states, particularly the lowest energy triplet state, $T_1$, is required. Here we describe a model of pseudo-octahedral complexes based on a pseudo-angular momentum representation and show that the predictions of this model are in excellent agreement with experiment - even when the deviations from octahedral symmetry are large. This model gives a natural explanation of zero-field splitting of $T_1$ and of the relative radiative rates of the three sublevels in terms of the conservation of time-revers...

  2. Comparative Analyses of Brookhaven National Laboratory Nuclear Decay Measurements and Super-Kamiokande Solar Neutrino Measurements: Neutrinos and Neutrino-Induced Beta-Decays as Probes of the Deep Solar Interior

    Science.gov (United States)

    Sturrock, P. A.; Fischbach, E.; Scargle, J. D.

    2016-12-01

    An experiment carried out at the Brookhaven National Laboratory over a period of almost 8 years acquired 364 measurements of the beta-decay rates of a sample of {}^{32}Si and, for comparison, of a sample of {}^{36}Cl. The experimenters reported finding " small periodic annual deviations of the data points from an exponential decay … of uncertain origin". We find that power-spectrum and spectrogram analyses of these datasets show evidence not only of the annual oscillations, but also of transient oscillations with frequencies near 11 year-1 and 12.5 year-1. Similar analyses of 358 measurements of the solar neutrino flux acquired by the Super-Kamiokande neutrino observatory over a period of about 5 years yield evidence of an oscillation near 12.5 year-1 and another near 9.5 year-1. An oscillation near 12.5 year-1 is compatible with the influence of rotation of the radiative zone. We suggest that an oscillation near 9.5 year-1 may be indicative of rotation of the solar core, and that an oscillation near 11 year-1 may have its origin in a tachocline between the core and the radiative zone. Modulation of the solar neutrino flux may be attributed to an influence of the Sun's internal magnetic field by the Resonant Spin Flavor Precession (RSFP) mechanism, suggesting that neutrinos and neutrino-induced beta decays can provide information about the deep solar interior.

  3. Synthesis of a quantum nanocrystal-gold nanoshell complex for near-infrared generated fluorescence and photothermal decay of luminescence

    Science.gov (United States)

    Lin, Adam Y.; Young, Joseph K.; Nixon, Ariel V.; Drezek, Rebekah A.

    2014-08-01

    Multifunction nanoparticle complexes have previously been developed to aid physicians in both diagnosis and treatment of cancerous tissue. Here, we designed a nanoparticle complex structure that consists of a plasmonically active hollow gold nanoshell core surrounded by photoluminescent quantum nanocrystals (QNs) in the form of PbS encapsulated by a silica layer. There are three main design variables including HGN synthesis and optical tuning, formation of the silica layer on the hollow gold nanoshell surface, and fabrication and photoluminescence tuning of PbS quantum nanocrystals. The hollow gold nanoshells were deliberately designed to function in the optical regimes that maximize tissue transmissivity (800 nm) and minimize tissue absorption (1100 nm). Secondly, several chemical ligands were tested such as (3-mercaptopropyl)trimethoxysilane and mercaptoundecanoic acid for controlled growth of the silica layer. Last, PbS QNs were synthesized and optimized with various capping agents, where the nanocrystals excited at the same wavelength were used to activate the photothermal properties of the hollow gold nanoshells. Upon irradiation of the complex with a lower power 800 nm laser, the nanocrystals luminesce at 1100 nm. At ablative temperatures the intrinsic luminescent properties of the QNs are altered and the luminescent output is significantly reduced (>70%). While this paper focuses on synthesis and optimization of the QN-HGN complex, in the future we believe that this novel particle complex design may have the potential to serve as a triple theranostic agent, which will aid satellite tumor localization, photothermal treatment, and ablative confirmation.Multifunction nanoparticle complexes have previously been developed to aid physicians in both diagnosis and treatment of cancerous tissue. Here, we designed a nanoparticle complex structure that consists of a plasmonically active hollow gold nanoshell core surrounded by photoluminescent quantum nanocrystals (QNs

  4. Genetic structure of the polymorphic metrosideros (Myrtaceae complex in the Hwaiian islands using nuclear microsatellite data.

    Directory of Open Access Journals (Sweden)

    Danica T Harbaugh

    Full Text Available BACKGROUND: Five species of Metrosideros (Myrtaceae are recognized in the Hawaiian Islands, including the widespread M. polymorpha, and are characterized by a multitude of distinctive, yet overlapping, habit, ecological, and morphological forms. It remains unclear, despite several previous studies, whether the morphological variation within Hawaiian Metrosideros is due to hybridization, genetic polymorphism, phenotypic plasticity, or some combination of these processes. The Hawaiian Metrosideros complex has become a model system to study ecology and evolution; however this is the first study to use microsatellite data for addressing inter-island patterns of variation from across the Hawaiian Islands. METHODOLOGY/PRINCIPAL FINDINGS: Ten nuclear microsatellite loci were genotyped from 143 individuals of Metrosideros. We took advantage of the bi-parental inheritance and rapid mutation rate of these data to examine the validity of the current taxonomy and to investigate whether Metrosideros plants from the same island are more genetically similar than plants that are morphologically similar. The Bayesian algorithm of the program structure was used to define genetic groups within Hawaiian Metrosideros and the closely related taxon M. collina from the Marquesas and Austral Islands. Several standard and nested AMOVAs were conducted to test whether the genetic diversity is structured geographically or taxonomically. CONCLUSIONS/SIGNIFICANCE: The results suggest that Hawaiian Metrosideros have dynamic gene flow, with genetic and morphological diversity structured not simply by geography or taxonomy, but as a result of parallel evolution on islands following rampant island-island dispersal, in addition to ancient chloroplast capture. Results also suggest that the current taxonomy requires major revisions in order to reflect the genetic structure revealed in the microsatellite data.

  5. Contribution of nuclear morphometric features to differentiation of atypical complex type endometrial hyperplasia and low grade endometrial carcinoma

    Directory of Open Access Journals (Sweden)

    Onder Onguru

    2011-08-01

    Full Text Available Objective: The differentiation of atypical complex type endometrial hyperplasia (ACEH and low grade endometrial carcinoma (EC may be problematic in endometrial biopsy materials. Desmoplasia and stromal invasion are diagnostic for EC but they are not always demonstrated in endometrial biopsies. In this study, we investigated the contribution of nuclear morphometry to distinction of ACEH and low grade EC. Methods: Ten low grade EC and eight ACEH cases retrieved from the archives of the Department of Pathology. For each case at least 100 nuclei (totally 1000 for both groups were selected using hematoxylen-eosine stained sections and evaluated by a computer assisted system. Measured nuclear morphometric features were nuclear area, nuclear perimeter, circular form factor, diameter equivalent circle, minimum feret, maximum feret, area convex hull, perimeter convex hull. Results: There was no significant differences between these two groups for circular form factor (P=0.871. But all other morphometric features were statistically significant (P<0.05. Conclusion: Our findings suggest that nuclear morphometric features may be used as an ancillary diagnostic tool in addition to conventional histopathological findings in borderline lesion. These findings should be confirmed with expanded case series. [J Exp Integr Med 2011; 1(4.000: 277-280

  6. Nuclear magnetic resonance study of charge transfer complex formation between Silver Nitrate and Benzylcyanide in Solvent Ethylene Glycol

    CERN Document Server

    Modarress, H

    2003-01-01

    The formation constant for charge transfer complexes between electron acceptor (AgNo sub 3) and electron donor benzylcyanide (C sub 6 H sub 5 -CH sub 2 -C ident to N) in solvent ethyleneglycol [(CH sub 2 OH) sub 2] has been evaluated by using the nuclear magnetic resonance chemical shifts of aromatic group of benzylcyanide measured against external references, tetramethylsilane, hexamethyldisilane and cyclohexane at 20 sup d ig sup C. The external referencing procedure eliminated the interference of internal reference in the course of complexation. The necessary bulk magnetic susceptibility corrections on the measured chemical shifts have been made. The solution nationalised and their effects on the formation constant have been considered and a new equation has been suggested to obtain the main ionic activity coefficient of AgNO sub 3 from nuclear magnetic resonance results. The mean ionic activity coefficient has been taken into account in the formation constant calculations. The results indicated that the a...

  7. Radioactive decay data tables

    Energy Technology Data Exchange (ETDEWEB)

    Kocher, D.C.

    1981-01-01

    The estimation of radiation dose to man from either external or internal exposure to radionuclides requires a knowledge of the energies and intensities of the atomic and nuclear radiations emitted during the radioactive decay process. The availability of evaluated decay data for the large number of radionuclides of interest is thus of fundamental importance for radiation dosimetry. This handbook contains a compilation of decay data for approximately 500 radionuclides. These data constitute an evaluated data file constructed for use in the radiological assessment activities of the Technology Assessments Section of the Health and Safety Research Division at Oak Ridge National Laboratory. The radionuclides selected for this handbook include those occurring naturally in the environment, those of potential importance in routine or accidental releases from the nuclear fuel cycle, those of current interest in nuclear medicine and fusion reactor technology, and some of those of interest to Committee 2 of the International Commission on Radiological Protection for the estimation of annual limits on intake via inhalation and ingestion for occupationally exposed individuals.

  8. Putative members of the Arabidopsis Nup107-160 nuclear pore sub-complex contribute to pathogen defense.

    Science.gov (United States)

    Wiermer, Marcel; Cheng, Yu Ti; Imkampe, Julia; Li, Meilan; Wang, Dongmei; Lipka, Volker; Li, Xin

    2012-06-01

    In eukaryotic cells, transduction of external stimuli into the nucleus to induce transcription and export of mRNAs for translation in the cytoplasm is mediated by nuclear pore complexes (NPCs) composed of nucleoporin proteins (Nups). We previously reported that Arabidopsis MOS3, encoding the homolog of vertebrate Nup96, is required for plant immunity and constitutive resistance mediated by the de-regulated Toll interleukin 1 receptor/nucleotide-binding/leucine-rich repeat (TNL)-type R gene snc1. In vertebrates, Nup96 is a component of the conserved Nup107-160 nuclear pore sub-complex, and implicated in immunity-related mRNA export. Here, we used a reverse genetics approach to examine the requirement for additional subunits of the predicted Arabidopsis Nup107-160 complex in plant immunity. We show that, among eight putative complex members, beside MOS3, only plants with defects in Nup160 or Seh1 are impaired in basal resistance. Constitutive resistance in the snc1 mutant and immunity mediated by TNL-type R genes also depend on functional Nup160 and have a partial requirement for Seh1. Conversely, resistance conferred by coiled coil-type immune receptors operates largely independently of both genes, demonstrating specific contributions to plant defense signaling. Our functional analysis further revealed that defects in nup160 and seh1 result in nuclear accumulation of poly(A) mRNA, and, in the case of nup160, considerable depletion of EDS1, a key positive regulator of basal and TNL-triggered resistance. These findings suggest that Nup160 is required for nuclear mRNA export and full expression of EDS1-conditioned resistance pathways in Arabidopsis.

  9. Superallowed 0+ to 0+ nuclear beta decays: A new survey with precision tests of the conserved vector current hypothesis and the standard model

    CERN Document Server

    Hardy, J C

    2008-01-01

    A new critical survey is presented of all half-life, decay-energy and branching-ratio measurements related to 20 0+ to 0+ beta decays. Compared with our last review, there are numerous improvements: First, we have added 27 recently published measurements and eliminated 9 references; of particular importance, the new data include a number of high-precision Penning-trap measurements of decay energies. Second, we have used the recently improved isospin symmetry-breaking corrections. Third, our calculation of the statistical rate function now accounts for possible excitation in the daughter atom. Finally, we have re-examined the systematic uncertainty associated with the isospin symmetry-breaking corrections by evaluating the radial-overlap correction using Hartree-Fock radial wave functions and comparing the results with our earlier calculations, which used Saxon-Woods wave functions; the provision for systematic uncertainty has been changed as a consequence. The new corrected Ft values are impressively constant...

  10. JENDL FP decay data file 2000

    Energy Technology Data Exchange (ETDEWEB)

    Katakura, Jun-ichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yoshida, Tadashi [Musashi Inst. of Tech., Tokyo (Japan); Oyamatsu, Kazuhiro [Aichi Shukutoku Univ., Nagakute, Aichi (Japan); Tachibana, Takahiro [Waseda Univ., Tokyo (Japan)

    2001-07-01

    A decay data file of fission product (FP) nuclides has been developed for the use in nuclear technology field as one of special purpose files of JENDL (Japanese Evaluated Nuclear Data Library) in the format of ENDF/B and it is called JENDL FP Decay Data File 2000. The file includes the decay data for 1229 fission product nuclides: 142 stable and 1087 unstable nuclides. The data included for a nuclide are decay modes, their Q values and branching ratios, average decay energy values of beta-rays, gamma-rays and alpha-particles and their spectral data. The primary source of the decay data is ENSDF (Evaluated Nuclear Structure Data File), which is the internationally recognized data file of nuclear structure properties. The data in ENSDF, however, cover only measured ones. The data of the short-lived nuclides needed for the application fields such as decay heat prediction are often incomplete or not measured because of their short half-lives. For such nuclides a theoretical model calculation is applied to derive the needed data such as average decay energies and spectral data. The data in JENDL FP Decay Data File 2000 have been tested by summation calculation comparing its results with measured data of decay heat values and aggregate fission product spectra of various fissioning nuclei. The comparison showed good agreement between the calculated results and the measured values. (author)

  11. Spectroscopic studies on two mono nuclear iron (III) complexes derived from a schiff base and an azodye

    Energy Technology Data Exchange (ETDEWEB)

    Mini, S., E-mail: sadasivan.v@gmail.com; Sadasivan, V., E-mail: sadasivan.v@gmail.com [University College, M G Road, Palayam, Thiruvananthapuram 695 034 Kerala (India); Meena, S. S., E-mail: ssingh@barc.gov.in; Bhatt, Pramod, E-mail: ssingh@barc.gov.in [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2014-10-15

    Two new mono nuclear Fe(III) complexes of an azodye (ANSN) and a Schiff base (FAHP) are reported. The azodye is prepared by coupling diazotized 1-amino-2-naphthol-4-sulphonicacid with 2-naphthol and the Schiff base is prepared by condensing 2-amino-3-hydroxy pyridine with furfural. The complexes were synthesized by the reaction of FeCl{sub 3}Ðœ‡2H{sub 2}O with respective ligands. They were characterized on the basis of elemental analysis and spectral studies like IR, NMR, Electronic and M.ssbauer. Magnetic susceptibility and Molar conductance of complexes at room temperature were studied. Based on the spectroscopic evidences and other analytical data the complexes are formulated as[Fe(ANSN)Cl(H{sub 2}O){sub 2}] and [Fe(FAHP)Cl{sub 2}(H{sub 2}O){sub 2}].

  12. Mengovirus-induced rearrangement of the nuclear pore complex: hijacking cellular phosphorylation machinery.

    NARCIS (Netherlands)

    Bardina, M.V.; Lidsky, P.V.; Sheval, E.V.; Fominykh, K.V.; Kuppeveld, F.J.M. van; Polyakov, V.Y.; Agol, V.I.

    2009-01-01

    Representatives of several picornavirus genera have been shown previously to significantly enhance non-controllable bidirectional exchange of proteins between nuclei and cytoplasm. In enteroviruses and rhinoviruses, enhanced permeabilization of the nuclear pores appears to be primarily due to proteo

  13. Low Energy Nuclear Transmutation in Condensed Matter Induced by D2 Gas Permeation Through pd Complexes:. Correlation Between Deuterium Flux and Nuclear Products

    Science.gov (United States)

    Iwamura, Y.; Itoh, T.; Sakano, M.; Sakai, S.; Kuribayashi, S.

    2005-12-01

    Observations of low energy nuclear reactions induced by D2 gas permeation through Pd complexes (Pd/CaO/Pd) were presented at ICCF-91 and in a paper2 published in the Japanese Journal of Applied Physics. When Cs was added on the surface of a Pd complex, Pr emerged on the surface while Cs decreased after the Pd complex was subjected to D2 gas permeation. When Sr was added to the surface, Mo emerged while the Sr decreased after D2 gas permeation. The isotopic composition of the detected Mo was different from the natural abundance. In this paper, recent progress of our research is described. The detected Pr was confirmed by various methods such as TOF-SIMS, XANES, X-ray Fluorescence Spectrometry and ICP-MS. Analysis of the depth profile of Pr indicated that a very thin surface region up to 100 Å was the active transmutation zone. Many experimental results showed that the quantity of Pr was proportional to the deuterium flux through Pd complex. The cross-section of transmutation of Cs into Pr can be roughly estimated at 1 barn if we consider the deuterium flux as an ultra low energy deuteron beam.

  14. Plant nonsense-mediated mRNA decay is controlled by different autoregulatory circuits and can be induced by an EJC-like complex

    Science.gov (United States)

    Nyikó, Tünde; Kerényi, Farkas; Szabadkai, Levente; Benkovics, Anna H.; Major, Péter; Sonkoly, Boglárka; Mérai, Zsuzsanna; Barta, Endre; Niemiec, Emilia; Kufel, Joanna; Silhavy, Dániel

    2013-01-01

    Nonsense-mediated mRNA decay (NMD) is a eukaryotic quality control system that recognizes and degrades transcripts containing NMD cis elements in their 3′untranslated region (UTR). In yeasts, unusually long 3′UTRs act as NMD cis elements, whereas in vertebrates, NMD is induced by introns located >50 nt downstream from the stop codon. In vertebrates, splicing leads to deposition of exon junction complex (EJC) onto the mRNA, and then 3′UTR-bound EJCs trigger NMD. It is proposed that this intron-based NMD is vertebrate specific, and it evolved to eliminate the misproducts of alternative splicing. Here, we provide evidence that similar EJC-mediated intron-based NMD functions in plants, suggesting that this type of NMD is evolutionary conserved. We demonstrate that in plants, like in vertebrates, introns located >50 nt from the stop induces NMD. We show that orthologs of all core EJC components are essential for intron-based plant NMD and that plant Partner of Y14 and mago (PYM) also acts as EJC disassembly factor. Moreover, we found that complex autoregulatory circuits control the activity of plant NMD. We demonstrate that expression of suppressor with morphogenic effect on genitalia (SMG)7, which is essential for long 3′UTR- and intron-based NMD, is regulated by both types of NMD, whereas expression of Barentsz EJC component is downregulated by intron-based NMD. PMID:23666629

  15. Convivial Decay

    DEFF Research Database (Denmark)

    Cohn, Marisa

    2016-01-01

    in the life of infrastructure we can observe common issues associated with aging infrastructures – hardware’s material decay, programming languages and software tools reaching end of support, obsolete managerial methodologies, etc. Such a case of infrastructural decay reveals how work of infrastructure...... maintenance may reach the limits of repair and shift from repair-as-sustaining into a mode of repair- into-decay, actively working towards the end-of-life. What this reveals is that, rather than infrastructural decay being a natural by-product of time’s passing, there is active work that goes into producing......This paper discusses the empirical case of an aging and obsolescent infrastructure supporting a space science mission that is currently approaching a known end. Such a case contributes to our understanding of the degrading path at the end-of-life of an infrastructure. During this later stage...

  16. Reproductive biology and variation of nuclear ribosomal ITS and ETS sequences in the Calligonum mongolicum complex (Polygonaceae).

    Science.gov (United States)

    Shi, Wei; Wen, Jun; Zhao, Yanfeng; Johnson, Gabriel; Pan, Borong

    2017-01-01

    To explore the biosystematics of the Calligonum mongolicum complex (Polygonaceae), the flowering phenological period, breeding and pollination characters and seed set of the complex (Calligonum Mongolicum Turze, Calligonum chinense A. Los., Calligonum gobicum A. Los., Calligonum pumilum A. Los. and Calligonum zaidamense A. Los.) were documented in the Turpan Eremophyte Botanical Garden, China. The sequences of the nuclear ribosomal ITS and ETS region were employed to differentiate the Calligonum mongolicum complex and other species in sect. Medusae. The results showed species of the Calligonum mongolicum complex occupied overlapping flowering periods and had consistent pollination agents. Their breeding systems are all self-compatible, tend to be out-crossing and they interbreed amongst each other (out-crossing index, OCI = 4).The crosses within and amongst species had high seed sets (44 - 65%). Phylogenetic analyses of Calligonum sect. Medusae and the network analysis of nrDNA (ITS and ETS) in the complex suggest interbreeding amongst "species" within the complex and provide evidence for taxonomically merging the five species in the complex. The detected hybridisation, occurring within the complex, suggests the need to improve traditional methods of ex situ plant conservation in botanical gardens for maintaining genetic diversity of Calligonum within and amongst species from different geographic areas.

  17. Reproductive biology and variation of nuclear ribosomal ITS and ETS sequences in the Calligonum mongolicum complex (Polygonaceae

    Directory of Open Access Journals (Sweden)

    Wei Shi

    2017-01-01

    Full Text Available To explore the biosystematics of the Calligonum mongolicum complex (Polygonaceae, the flowering phenological period, breeding and pollination characters and seed set of the complex (C. Mongolicum Turze, C. chinense A. Los., C. gobicum A. Los., C. pumilum A. Los. and C. zaidamense A. Los. were documented in the Turpan Eremophyte Botanical Garden, China. The sequences of the nuclear ribosomal ITS and ETS region were employed to differentiate the C. mongolicum complex and other species in sect. Medusae. The results showed species of the C. mongolicum complex occupied overlapping flowering periods and had consistent pollination agents. Their breeding systems are all self-compatible, tend to be out-crossing and they interbreed amongst each other (out-crossing index, OCI = 4.The crosses within and amongst species had high seed sets (44 - 65%. Phylogenetic analyses of Calligonum sect. Medusae and the network analysis of nrDNA (ITS and ETS in the complex suggest interbreeding amongst “species” within the complex and provide evidence for taxonomically merging the five species in the complex. The detected hybridisation, occurring within the complex, suggests the need to improve traditional methods of ex situ plant conservation in botanical gardens for maintaining genetic diversity of Calligonum within and amongst species from different geographic areas.

  18. Med1 subunit of the mediator complex in nuclear receptor-regulated energy metabolism, liver regeneration, and hepatocarcinogenesis.

    Science.gov (United States)

    Jia, Yuzhi; Viswakarma, Navin; Reddy, Janardan K

    2014-01-01

    Several nuclear receptors regulate diverse metabolic functions that impact on critical biological processes, such as development, differentiation, cellular regeneration, and neoplastic conversion. In the liver, some members of the nuclear receptor family, such as peroxisome proliferator-activated receptors (PPARs), constitutive androstane receptor (CAR), farnesoid X receptor (FXR), liver X receptor (LXR), pregnane X receptor (PXR), glucocorticoid receptor (GR), and others, regulate energy homeostasis, the formation and excretion of bile acids, and detoxification of xenobiotics. Excess energy burning resulting from increases in fatty acid oxidation systems in liver generates reactive oxygen species, and the resulting oxidative damage influences liver regeneration and liver tumor development. These nuclear receptors are important sensors of exogenous activators as well as receptor-specific endogenous ligands. In this regard, gene knockout mouse models revealed that some lipid-metabolizing enzymes generate PPARα-activating ligands, while others such as ACOX1 (fatty acyl-CoA oxidase1) inactivate these endogenous PPARα activators. In the absence of ACOX1, the unmetabolized ACOX1 substrates cause sustained activation of PPARα, and the resulting increase in energy burning leads to hepatocarcinogenesis. Ligand-activated nuclear receptors recruit the multisubunit Mediator complex for RNA polymerase II-dependent gene transcription. Evidence indicates that the Med1 subunit of the Mediator is essential for PPARα, PPARγ, CAR, and GR signaling in liver. Med1 null hepatocytes fail to respond to PPARα activators in that these cells do not show induction of peroxisome proliferation and increases in fatty acid oxidation enzymes. Med1-deficient hepatocytes show no increase in cell proliferation and do not give rise to liver tumors. Identification of nuclear receptor-specific coactivators and Mediator subunits should further our understanding of the complexities of metabolic

  19. Proton Decay

    OpenAIRE

    Hikosaka, Koki

    2002-01-01

    We discuss the status of supersymmetric grand unified theories [SUSY GUTs] with regards to the observation of proton decay. In this talk we focus on SUSY GUTs in 4 dimensions. We outline the major theoretical uncertainties present in the calculation of the proton lifetime and then present our best estimate of an absolute upper bound on the predicted proton lifetime. Towards the end, we consider some new results in higher dimensional GUTs and the ramifications for proton decay.

  20. Semi Empirical Formula For Neutrinoless Double Beta Decay

    National Research Council Canada - National Science Library

    M K PREETHI RAJAN; R K BIJU; K P SANTHOSH

    2016-01-01

    A Semi empirical formula for both phase space factor and Nuclear Matrix Element (NME) is developed for neutrinoless double beta decay, and the formula is used to compute the neutrinoless double beta decay half lives...

  1. Towards monitoring transport of single cargos across individual nuclear pore complexes by time-lapse atomic force microscopy.

    Science.gov (United States)

    Huang, Ning-Ping; Stubenrauch, Mike; Köser, Joachim; Taschner, Nicole; Aebi, Ueli; Stolz, Martin

    2010-08-01

    A new preparation procedure was developed for the stable adsorption of either the cytoplasmic or the nuclear face of native (i.e. in physiological buffer without detergent extraction and in the absence of chemical fixatives) Xenopus oocyte nuclear envelopes (NEs) onto silicon (Si) surfaces. This yields optimal structural preservation of the nuclear pore complexes (NPCs) without compromising their functional properties. The functional viability of thus prepared NPCs was documented by time-lapse atomic force microscopy (AFM) of the reversible calcium-mediated opening (i.e. +Ca(2+)) and closing (i.e. -Ca(2+)) of the iris diaphragm-like distal ring topping the NPCs' nuclear baskets. Moreover, site-specific single colloidal gold particle detection was documented by AFM imaging one and the same NPC before and after immuno-gold labeling the sample with a nucleoporin-specific antibody. With this new preparation protocol at hand, we should eventually be able to follow by time-lapse AFM transport of single gold-conjugated cargos across individual NPCs.

  2. Estimation of the ripple effects on a regional community of the formation of the nuclear energy science complex in Gyeongju

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung-Sik [Dankook Univ., Chungnam (Korea, Republic of). Dept. of Nuclear Engineering; Moon, Joo Hyun [Dongguk Univ. Gyeongju, Gyeongbuk (Korea, Republic of). Dept. of Nuclear Energy Engineering

    2017-05-15

    Korea has developed advanced nuclear technologies, including those for future nuclear energy systems and the safe management of spent nuclear fuel, and is about to make a decision as to whether to make a massive investment in the development R and D for commercialization of them. There is no area large enough to accommodate all the development R and D-related facilities together at Korea Atomic Energy Research Institute (KAERI) to perform the development R and Ds. KAERI seeks solutions to the space problem, which includes the construction of a nuclear energy science complex (NESC). Gyeongju is one of the potential sites. This study estimated the ripple effects on the regional community if the NESC is to be formed in Gyeongju using inter-regional input-output analysis. The estimation shows that the ripple effects to the regional community of the formation of the NESC in Gyeongju would be 1,086,633 billion Korean Won (KRW) for regional production inducement, 455,299 billion KRW for value-added inducement, and 9,592 persons for employment inducement.

  3. Natural disease course and genotype-phenotype correlations in Complex I deficiency caused by nuclear gene defects: what we learned from 130 cases.

    NARCIS (Netherlands)

    Koene, S.; Rodenburg, R.J.T.; Knaap, M.S. van der; Willemsen, M.A.A.P.; Sperl, W.; Laugel, V.; Ostergaard, E.; Tarnopolsky, M.; Martin, M.A.; Nesbitt, V.; Fletcher, J.; Edvardson, S.; Procaccio, V.; Slama, A.; Heuvel, L.P.W.J. van den; Smeitink, J.A.M.

    2012-01-01

    Mitochondrial complex I is the largest multi-protein enzyme complex of the oxidative phosphorylation system. Seven subunits of this complex are encoded by the mitochondrial and the remainder by the nuclear genome. We review the natural disease course and signs and symptoms of 130 patients (four new

  4. Seal Out Tooth Decay

    Science.gov (United States)

    ... Decay (Caries) > Seal Out Tooth Decay Seal Out Tooth Decay Main Content What are dental sealants? How are ... fix decayed teeth. Back to Top What causes tooth decay? Germs in the mouth use the sugar in ...

  5. The development of a single molecule fluorescence standard and its application in estimating the stoichiometry of the nuclear pore complex.

    Science.gov (United States)

    Tie, Hieng Chiong; Madugula, Viswanadh; Lu, Lei

    2016-09-30

    We report here an image-based method to quantify the stoichiometry of diffraction-limited sub-cellular protein complexes in vivo under spinning disk confocal microscopy. A GFP single molecule fluorescence standard was first established by immobilizing His-tagged GFP molecules onto the glass surface via nickel nitrilotriacetic acid functionalized polyethylene glycol. When endogenous nucleoporins were knocked down and replaced by the exogenously expressed and knockdown-resistant GFP-nucleoporins, the stoichiometry of the nucleoporin was estimated by the ratio of its fluorescence intensity to that of the GFP single molecules. Our measured stoichiometry of Nup35, Nup93, Nup133 and Nup88 is 23, 18, 14 and 9 and there are possibly16 copies of Nup107-160 complex per nuclear pore complex.

  6. NSF- and SNARE-mediated membrane fusion is required for nuclear envelope formation and completion of nuclear pore complex assembly in Xenopus laevis egg extracts.

    Science.gov (United States)

    Baur, Tina; Ramadan, Kristijan; Schlundt, Andreas; Kartenbeck, Jürgen; Meyer, Hemmo H

    2007-08-15

    Despite the progress in understanding nuclear envelope (NE) reformation after mitosis, it has remained unclear what drives the required membrane fusion and how exactly this is coordinated with nuclear pore complex (NPC) assembly. Here, we show that, like other intracellular fusion reactions, NE fusion in Xenopus laevis egg extracts is mediated by SNARE proteins that require activation by NSF. Antibodies against Xenopus NSF, depletion of NSF or the dominant-negative NSF(E329Q) variant specifically inhibited NE formation. Staging experiments further revealed that NSF was required until sealing of the envelope was completed. Moreover, excess exogenous alpha-SNAP that blocks SNARE function prevented membrane fusion and caused accumulation of non-flattened vesicles on the chromatin surface. Under these conditions, the nucleoporins Nup107 and gp210 were fully recruited, whereas assembly of FxFG-repeat-containing nucleoporins was blocked. Together, we define NSF- and SNARE-mediated membrane fusion events as essential steps during NE formation downstream of Nup107 recruitment, and upstream of membrane flattening and completion of NPC assembly.

  7. Autographa californica Multiple Nucleopolyhedrovirus Ac34 Protein Retains Cellular Actin-Related Protein 2/3 Complex in the Nucleus by Subversion of CRM1-Dependent Nuclear Export

    NARCIS (Netherlands)

    Mu, Jingfang; Zhang, Yongli; Hu, Yangyang; Hu, Xue; Zhou, Yuan; Zhao, He; Pei, Rongjuan; Wu, Chunchen; Chen, Jizheng; Zhao, Han; Yang, Kai; Oers, van Monique; Chen, Xinwen; Wang, Yun

    2016-01-01

    Actin, nucleation-promoting factors (NPFs), and the actin-related protein 2/3 complex (Arp2/3) are key elements of the cellular actin polymerization machinery. With nuclear actin polymerization implicated in ever-expanding biological processes and the discovery of the nuclear import mechanisms of ac

  8. Nuclear Decay Data for the International Reactor Dosimetry Library for Fission and Fusion (IRDFF: Updated Evaluations of the Half-Lives and Gamma Ray Intensities

    Directory of Open Access Journals (Sweden)

    Chechev Valery P.

    2016-01-01

    Full Text Available Updated evaluations of the half-lives and prominent gamma ray intensities have been presented for 20 radionuclides – dosimetry reaction residuals. The new values of these decay characteristics recommended for the IRDFF library were obtained using the approaches and methodology adopted by the working group of the Decay Data Evaluation Project (DDEP cooperation. The experimental data published up to 2014 were taken into account in updated evaluations. The list of radionuclides includes 3H, 18F, 22Na, 24Na, 46Sc, 51Cr, 54Mn, 59Fe, 57Co, 60Co, 57Ni, 64Cu, 88Y, 132Te, 131I, 140Ba, 140La, 141Ce, 182Ta, 198Au.

  9. SU-E-J-61: Electrodynamics and Nano-Scale Fluid Dynamics in Protein Localization of Nuclear Pore Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, J; Gatenby, R [Moffitt Cancer Research Institute, Tampa, FL (United States)

    2014-06-01

    Purpose: To develop a simulation to catalyze a reevaluation of common assumptions about 3 dimensional diffusive processes and help cell biologists gain a more nuanced, intuitive understanding of the true physical hurdles of protein signaling cascades. Furthermore, to discuss the possibility of intracellular electrodynamics as a critical, unrecognized component of cellular biology and protein dynamics that is necessary for optimal information flow from the cell membrane to the nucleus. Methods: The Unity 3D gaming physics engine was used to build an accurate virtual scale model of the cytoplasm within a few hundred nanometers of the nuclear membrane. A cloud of simulated pERK proteins is controlled by the physics simulation, where diffusion is based on experimentally measured values and the electrodynamics are based on theoretical nano-fluid dynamics. The trajectories of pERK within the cytoplasm and through the 1250 nuclear pores on the nuclear surface is recorded and analyzed. Results: The simulation quickly demonstrates that pERKs moving solely by diffusion will rarely locate and come within capture distance of a nuclear pore. The addition of intracellular electrodynamics between charges on the nuclear pore complexes and on pERKs increases the number of successful translocations by allowing the electro-physical attractive effects to draw in pERKs from the cytoplasm. The effects of changes in intracellular shielding ion concentrations allowed for estimation of the “capture radius” under varying conditions. Conclusion: The simulation allows a shift in perspective that is paramount in attempting to communicate the scale and dynamics of intracellular protein cascade mechanics. This work has allowed researchers to more fully understand the parameters involved in intracellular electrodynamics, such as shielding anion concentration and protein charge. As these effects are still far below the spatial resolution of currently available measurement technology this

  10. Coinage metal complexes with bridging hybrid phosphine-NHC ligands: synthesis of di- and tetra-nuclear complexes.

    Science.gov (United States)

    Simler, Thomas; Braunstein, Pierre; Danopoulos, Andreas A

    2016-03-28

    A series of P-NHC-type hybrid ligands containing both PR2 and N-heterocyclic carbene (NHC) donors on meta-bis-substituted phenylene backbones, L(Cy), L(tBu) and L(Ph) (R = Cy, tBu, Ph, respectively), was accessed through a modular synthesis from a common precursor, and their coordination chemistry with coinage metals was explored and compared. Metallation of L(Ph)·n(HBr) (n = 1, 2) with Ag2O gave the pseudo-cubane [Ag4Br4(L(Ph))2], isostructural to [Ag4Br4(L(R))2] (R = Cy, tBu) (T. Simler, P. Braunstein and A. A. Danopoulos, Angew. Chem., Int. Ed., 2015, 54, 13691), whereas metallation of ·HBF4 (R = Ph, tBu) led to the dinuclear complexes [Ag2(L(R))2](BF4)2 which, in the solid state, feature heteroleptic Ag centres and a 'head-to-tail' (HT) arrangement of the bridging ligands. In solution, interconversion with the homoleptic 'head-to-head' (HH) isomers is facilitated by ligand fluxionality. 'Head-to-tail' [Cu2Br2(L(R))2] (R = Cy, tBu) dinuclear complexes were obtained from L(R)·HBr and [Cu5(Mes)5], Mes = 2,4,6-trimethylphenyl, which also feature bridging ligands and heteroleptic Cu centres. Although the various ligands L(R)l ed to structurally analogous complexes for R = Cy, tBu and Ph, the rates of dynamic processes occurring in solution are dependent on R, with faster rates for R = Ph. Transmetallation of both NHC and P donor groups from [Ag4Br4(L(tBu))2] to AuI by reaction with [AuCl(THT)] (THT = tetrahydrothiophene) led to L(tBu) transfer and to the dinuclear complex [Au2Cl2L(tBu)] with one L(tBu) ligand bridging the two Au centres. Except for the silver pseudo-cubanes, all other complexes do not exhibit metallophilic interactions.

  11. Tuning the decay time of lanthanide-based near infrared luminescence from micro- to milliseconds through d-->f energy transfer in discrete heterobimetallic complexes.

    Science.gov (United States)

    Torelli, Stéphane; Imbert, Daniel; Cantuel, Martine; Bernardinelli, Gérald; Delahaye, Sandra; Hauser, Andreas; Bünzli, Jean-Claude G; Piguet, Claude

    2005-05-20

    Inert and optically active pseudo-octahedral Cr(III)N6 and Ru(II)N6 chromophores have been incorporated by self-assembly into heterobimetallic triple-stranded helicates HHH-[CrLnL3]6+ and HHH-[RuLnL3]5+. The crystal structures of [CrLnL(3)](CF(3)SO(3))(6) (Ln=Nd, Eu, Yb, Lu) and [RuLnL3](CF3SO3)5 (Ln=Eu, Lu) demonstrate that the helical structure can accommodate metal ions of different sizes, without sizeable change in the intermetallic MLn distances. These systems are ideally suited for unravelling the molecular factors affecting the intermetallic nd-->4f communication. Visible irradiation of the Cr(III)N6 and Ru(II)N6 chromophores in HHH-[MLnL3]5/6+ (Ln=Nd, Yb, Er; M=Cr, Ru) eventually produces lanthanide-based near infrared (NIR) emission, after directional energy migration within the complexes. Depending on the kinetic regime associated with each specific d-f pair, the NIR luminescence decay times can be tuned from micro- to milliseconds. The origin of this effect, together with its rational control for programming optical functions in discrete heterobimetallic entities, are discussed.

  12. Phylogenetic relationships among the Caribbean members of the Cliona viridis complex (Porifera, Demospongiae, Hadromerida) using nuclear and mitochondrial DNA sequences.

    Science.gov (United States)

    Escobar, Dairo; Zea, Sven; Sánchez, Juan A

    2012-08-01

    Species complexes - groups of closely related species in which intraspecific and interspecific variability overlap - have generated considerable interest and study. Frequently, members of a species complex do not have complete reproductive isolation; therefore, the complex may go through extensive gene flow. In the Caribbean Sea, some encrusting and excavating sponges of the genus Cliona (Porifera, Hadromerida, Clionaidae) are grouped within the great "Cliona viridis" complex because of their morphological similarities. This study examined the evolutionary relationships of the Caribbean members of this complex (C. caribbaea, C. tenuis, C. aprica and C. varians) and related taxa based on nuclear (ITS1 and ITS2) and mitochondrial (3' end of ND6) DNA sequences. The intragenomic ITS variation and its secondary structures were evaluated using a mixed approach of Denaturing Gradient Gel Electrophoresis (DGGE), DNA sequencing and secondary structure prediction. Considerable intragenomic variation was found in all the species, with apparently functional ITS1 and ITS2 secondary structures. Despite the subtle but clear morphological differentiation in these excavating sponges, the intragenomic copies of C. caribbaea, C. tenuis and C. aprica had a polyphyletic placement in the ITS1 and ITS2 genealogies and very low divergence. Therefore, it is clear that these species constitute a species complex (herein called Ct-complex). Genetic distances within the Ct-complex revealed that an important part of the interspecific variation overlapped with intraspecific variation, suggesting either incomplete lineage sorting or extensive gene flow. In contrast, C. varians and an unidentified "Pione" species emerged as monophyletic clades, being the closest sister groups to the Ct-complex. Additionally, our results support that C. laticavicola and C. delitrix conform a monophyletic group, but absence of reciprocal monophyly in these species suggests they may be life stages or ecophenotypes of

  13. Structural characterisation of the nuclear import receptor importin alpha in complex with the bipartite NLS of Prp20.

    Directory of Open Access Journals (Sweden)

    Noelia Roman

    Full Text Available The translocation of macromolecules into the nucleus is a fundamental eukaryotic process, regulating gene expression, cell division and differentiation, but which is impaired in a range of significant diseases including cancer and viral infection. The import of proteins into the nucleus is generally initiated by a specific, high affinity interaction between nuclear localisation signals (NLSs and nuclear import receptors in the cytoplasm, and terminated through the disassembly of these complexes in the nucleus. For classical NLSs (cNLSs, this import is mediated by the importin-α (IMPα adaptor protein, which in turn binds to IMPβ to mediate translocation of nuclear cargo across the nuclear envelope. The interaction and disassembly of import receptor:cargo complexes is reliant on the differential localisation of nucleotide bound Ran across the envelope, maintained in its low affinity, GDP-bound form in the cytoplasm, and its high affinity, GTP-bound form in the nucleus. This in turn is maintained by the differential localisation of Ran regulating proteins, with RanGAP in the cytoplasm maintaining Ran in its GDP-bound form, and RanGEF (Prp20 in yeast in the nucleus maintaining Ran in its GTP-bound form. Here, we describe the 2.1 Å resolution x-ray crystal structure of IMPα in complex with the NLS of Prp20. We observe 1,091 Å(2 of buried surface area mediated by an extensive array of contacts involving residues on armadillo repeats 2-7, utilising both the major and minor NLS binding sites of IMPα to contact bipartite NLS clusters (17RAKKMSK(23 and (3KR(4, respectively. One notable feature of the major site is the insertion of Prp20NLS Ala(18 between the P0 and P1 NLS sites, noted in only a few classical bipartite NLSs. This study provides a detailed account of the binding mechanism enabling Prp20 interaction with the nuclear import receptor, and additional new information for the interaction between IMPα and cargo.

  14. B decays

    CERN Document Server

    Stone, Sheldon

    1994-01-01

    This book reviews the study of b quarks and also looks at the implications of future studies. The most important observations thus far - including measurement of the ""B"" lifetime and observations of b -> u transitions - as well as the more mundane results of hadronic and semileptonic transitions are described in detail by experimentalists who have been closely involved with the measurements. Theoretical progress in understanding b quark decays, including the mechanisms of hadronic and semileptonic decays, are described. Synthesizing the experimental and theoretical information, the authors d

  15. B decays

    CERN Document Server

    Stone, Sheldon

    1992-01-01

    The study of b quarks has now reached a stage where it is useful to review what has been learned so far and also to look at the implications of future studies. The most important observations thus far - measurement of the "B" lifetime, B 0 - B 0 mixing, and the observation of b? u transitions, as well as more mundane results on hadronic and semileptonic transitions - are described in detail by experimentalists who have been closely involved with the measurements. Theoretical progress in understanding b quark decays, including the mechanisms of hadronic and semileptonic decays, are described. S

  16. Statistical measure of complexity of hard-sphere gas: applications to nuclear matter

    OpenAIRE

    Moustakidis, Ch. C.; Chatzisavvas, K. Ch.; Nikolaidis, N. S.; Panos, C. P.

    2010-01-01

    We apply the statistical measure of complexity, introduced by L\\'{o}pez-Ruiz, Mancini and Calbet to a hard-sphere dilute Fermi gas whose particles interact via a repulsive hard-core potential. We employ the momentum distribution of this system to calculate the information entropy, the disequilibrium and the statistical complexity. We examine possible connections between the particle correlations and energy of the system with those information and complexity measures. The hard-sphere model ser...

  17. Nuclear pore complex remodeling by p75NTR cleavage controls TGF-β signaling and astrocyte functions

    Science.gov (United States)

    Schachtrup, Christian; Ryu, Jae Kyu; Mammadzada, Könül; Khan, Abdullah S.; Carlton, Peter M.; Perez, Alex; Christian, Frank; Le Moan, Natacha; Vagena, Eirini; Baeza-Raja, Bernat; Rafalski, Victoria; Chan, Justin P.; Nitschke, Roland; Houslay, Miles D.; Ellisman, Mark H.; Wyss-Coray, Tony; Palop, Jorge J.; Akassoglou, Katerina

    2016-01-01

    Astrocytes play critical roles in neuronal activity and inhibition of regeneration. Here we show that the cleaved p75 neurotrophin receptor (p75NTR) is a component of the nuclear pore complex (NPC) required for glial scar formation and reduced gamma oscillations in mice via regulation of TGF-β signaling. The cleaved p75NTR interacts with nucleoporins to promote Smad2 nucleocytoplasmic shuttling. Thus, NPC remodeling by regulated intramembrane cleavage of p75NTR controls astrocyte-neuronal communication in response to profibrotic factors. PMID:26120963

  18. Sequence complexities of the nuclear and mitochondrial genomes of the take-all fungus, Gaeumannomyces graminis var. tritici.

    Science.gov (United States)

    McFadden, J J; Buck, K W

    1983-11-01

    The nuclear (n) and mitochondrial (mt) genomes of the take-all fungus, Gaeumannomyces graminis var. tritici, were examined by reassociation kinetics with Escherichia coli DNA as internal standard. Only one kinetic component was detected in each DNA, with second-order rate constants of 0.022 M-1 S-1 for nDNA and 10.9 M-1 S-1 for mtDNA, corresponding to sequence complexities of 29 X 10(6) base pairs and 60 X 10(3) base pairs respectively.

  19. Novel way of capping mRNA trimer and studies of its interaction with human nuclear cap-binding complex.

    Science.gov (United States)

    Worch, Remigiusz; Stepinski, Janusz; Niedzwiecka, Anna; Jankowska-Anyszka, Marzena; Mazza, Catherine; Cusack, Stephen; Stolarski, Ryszard; Darzynkiewicz, Edward

    2005-01-01

    Binding of mRNA 5' cap by the nuclear cap-binding complex (CBC) is crucial for a wide variety of mRNA metabolic events. The interaction involving the CBP20 subunit of CBC is mediated by numerous hydrogen bonds and by stacking of the tyrosine sidechains with two first bases of the capped mRNA. To examine a possible role of a longer mRNA chain in the CBC-cap recognition, we have synthesized an mRNA tetramer using a novel way of capping an RNA trimer and determined its affinity for CBC by fluorescence titration.

  20. Statistical measure of complexity of hard-sphere gas: applications to nuclear matter

    CERN Document Server

    Moustakidis, Ch C; Nikolaidis, N S; Panos, C P

    2010-01-01

    We apply the statistical measure of complexity, introduced by L\\'{o}pez-Ruiz, Mancini and Calbet to a hard-sphere dilute Fermi gas whose particles interact via a repulsive hard-core potential. We employ the momentum distribution of this system to calculate the information entropy, the disequilibrium and the statistical complexity. We examine possible connections between the particle correlations and energy of the system with those information and complexity measures. The hard-sphere model serves as a test bed for concepts about complexity.

  1. Neutrino potential for neutrinoless double beta decay

    CERN Document Server

    Iwata, Yoritaka

    2016-01-01

    Neutrino potential for neutrinoless double beta decay is studied with focusing on its statistical property. The statistics provide a gross view of understanding amplitude of constitutional components of the nuclear matrix element.

  2. Overview of nuclear data

    Energy Technology Data Exchange (ETDEWEB)

    Firestone, R.B.

    2003-06-30

    For many years, nuclear structure and decay data have been compiled and disseminated by an International Network of Nuclear Structure and Decay Data (NSDD) evaluators under the auspices of the International Nuclear Data Committee (INDC) of the International Atomic Energy Agency (IAEA). In this lecture I will discuss the kinds of data that are available and describe various ways to obtain this information. We will learn about some of the publications that are available and Internet sources of nuclear data. You will be introduced to Isotope Explorer software for retrieving and displaying nuclear structure and radioactive decay data. The on-line resources Table of Radioactive Isotopes, PGAA Database Viewer, Nuclear Science Reference Search, Table of Isotopes Educational Website, and other information sources will be discussed. Exercises will be provided to increase your ability to understand, access, and use nuclear data.

  3. Complex composite engineering architectures for nuclear and high-radiation environments

    Energy Technology Data Exchange (ETDEWEB)

    Kornreich, Drew E [Los Alamos National Laboratory; Vaidya, Rajendra U [Los Alamos National Laboratory; Ammerman, Curtt N [Los Alamos National Laboratory

    2010-01-01

    Integrated Computational Materials Engineering (ICME) is a novel overarching approach to bridge length and time scales in computational materials science and engineering. This approach integrates all elements of multi-scale modeling (including various empirical and science-based models) with materials informatics to provide users the opportunity to tailor material selections based on stringent application needs. Typically, materials engineering has focused on structural requirements (stress, strain, modulus, fracture toughness etc.) while multi-scale modeling has been science focused (mechanical threshold strength model, grain-size models, solid-solution strengthening models etc.). Materials informatics (mechanical property inventories) on the other hand, is extensively data focused. All of these elements are combined within the framework of ICME to create architecture for the development, selection and design new composite materials for challenging environments. We propose development of the foundations for applying ICME to composite materials development for nuclear and high-radiation environments (including nuclear-fusion energy reactors, nuclear-fission reactors, and accelerators). We expect to combine all elements of current material models (including thermo-mechanical and finite-element models) into the ICME framework. This will be accomplished through the use of a various mathematical modeling constructs. These constructs will allow the integration of constituent models, which in tum would allow us to use the adaptive strengths of using a combinatorial scheme (fabrication and computational) for creating new composite materials. A sample problem where these concepts are used is provided in this summary.

  4. [Estimation of cost-saving for reducing radioactive waste from nuclear medicine facilities by implementing decay in storage (DIS) in Japan].

    Science.gov (United States)

    Kida, Tetsuo; Hiraki, Hitoshi; Yamaguchi, Ichirou; Fujibuchi, Toshioh; Watanabe, Hiroshi

    2012-01-01

    DIS has not yet been implemented in Japan as of 2011. Therefore, even if risk was negligible, medical institutions have to entrust radioactive temporal waste disposal to Japan Radio Isotopes Association (JRIA) in the current situation. To decide whether DIS should be implemented in Japan or not, cost-saving effect of DIS was estimated by comparing the cost that nuclear medical facilities pay. By implementing DIS, the total annual cost for all nuclear medical facilities in Japan is estimated to be decreased to 30 million yen or less from 710 million yen. DIS would save 680 million yen (96%) per year.

  5. Definition of the nuclear encoded protein composition of bovine heart mitochondrial complex I. Identification of two new subunits.

    Science.gov (United States)

    Carroll, Joe; Shannon, Richard J; Fearnley, Ian M; Walker, John E; Hirst, Judy

    2002-12-27

    Mitochondrial NADH:ubiquinone oxidoreductase (complex I) from bovine heart is a complicated multisubunit, membrane-bound assembly. Seven subunits are encoded by mitochondrial DNA, and the sequences of 36 nuclear encoded subunits have been described. The subunits of complex I and two subcomplexes (Ialpha and Ibeta) were resolved on one- and two-dimensional gels and by reverse-phase high performance liquid chromatography. Mass spectrometric analysis revealed two previously unknown subunits in complex I, named B14.7 and ESSS, one in each subcomplex. Coding sequences for each protein were identified in data bases and were confirmed by cDNA cloning and sequencing. Subunit B14.7 has an acetylated N terminus, no presequence, and contains four potential transmembrane helices. It is homologous to subunit 21.3b from complex I in Neurospora crassa and is related to Tim17, Tim22, and Tim23, which are involved in protein translocation across the inner membrane. Subunit ESSS has a cleaved mitochondrial import sequence and one potential transmembrane helix. A total of 45 different subunits of bovine complex I have now been characterized.

  6. Slow-Motion Theory of Nuclear Spin Relaxation in Paramagnetic Low-Symmetry Complexes: A Generalization to High Electron Spin

    Science.gov (United States)

    Nilsson, T.; Kowalewski, J.

    2000-10-01

    The slow-motion theory of nuclear spin relaxation in paramagnetic low-symmetry complexes is generalized to comprise arbitrary values of S. We describe the effects of rhombic symmetry in the static zero-field splitting (ZFS) and allow the principal axis system of the static ZFS tensor to deviate from the molecule-fixed frame of the nuclear-electron dipole-dipole tensor. We show nuclear magnetic relaxation dispersion (NMRD) profiles for different illustrative cases, ranging from within the Redfield limit into the slow-motion regime with respect to the electron spin dynamics. We focus on S = 3/2 and compare the effects of symmetry-breaking properties on the paramagnetic relaxation enhancement (PRE) in this case with that of S = 1, which we have treated in a previous paper. We also discuss cases of S = 2, 5/2, 3, and 7/2. One of the main objectives of this investigation, together with the previous papers, is to provide a set of standard calculations using the general slow-motion theory, against which simplified models may be tested.

  7. Perinuclear Arp2/3-driven actin polymerization enables nuclear deformation to facilitate cell migration through complex environments.

    Science.gov (United States)

    Thiam, Hawa-Racine; Vargas, Pablo; Carpi, Nicolas; Crespo, Carolina Lage; Raab, Matthew; Terriac, Emmanuel; King, Megan C; Jacobelli, Jordan; Alberts, Arthur S; Stradal, Theresia; Lennon-Dumenil, Ana-Maria; Piel, Matthieu

    2016-03-15

    Cell migration has two opposite faces: although necessary for physiological processes such as immune responses, it can also have detrimental effects by enabling metastatic cells to invade new organs. In vivo, migration occurs in complex environments and often requires a high cellular deformability, a property limited by the cell nucleus. Here we show that dendritic cells, the sentinels of the immune system, possess a mechanism to pass through micrometric constrictions. This mechanism is based on a rapid Arp2/3-dependent actin nucleation around the nucleus that disrupts the nuclear lamina, the main structure limiting nuclear deformability. The cells' requirement for Arp2/3 to pass through constrictions can be relieved when nuclear stiffness is decreased by suppressing lamin A/C expression. We propose a new role for Arp2/3 in three-dimensional cell migration, allowing fast-moving cells such as leukocytes to rapidly and efficiently migrate through narrow gaps, a process probably important for their function.

  8. Testing Lorentz invariance in β decay

    NARCIS (Netherlands)

    Sytema, Auke

    2016-01-01

    In this thesis we investigate violation of Lorentz invariance in the weak interaction, specifically in β decay. For this purpose an experiment is performed with nuclear-spin-polarized 20Na that decays by emitting a β particle. Lorentz invariance is the property that the laws of nature do not depend

  9. Decay spectroscopy of $^{178}$Au

    CERN Document Server

    Whitmore, B

    In this thesis, the neutron-deficient nucleus $^{178}$Au is investigated through decay spectroscopy. Si and HPGe detectors were used to analyse the decay radiation of $^{178}$Au and its daughter nuclei. Previous studies have been unable to distinguish decay radiation from different isomeric states of this nucleus. This thesis represents the first time such isomeric discrimination has been achieved, and presents tentative spin assignments of both the ground state and an isomer. The neutron-deficient gold isotopes are an area of interest for the study of shape coexistence. This is the phenomenon exhibited by nuclei able to exist at a number of close lying energy minima, each reflecting a distinct type of deformation. It is hoped that studies such as this can help identify the evolution of nuclear deformation in this region of the nuclear chart.

  10. msl2 mRNA is bound by free nuclear MSL complex in Drosophila melanogaster

    Science.gov (United States)

    Johansson, Anna-Mia; Allgardsson, Anders; Stenberg, Per; Larsson, Jan

    2011-01-01

    In Drosophila, the global increase in transcription from the male X chromosome to compensate for its monosomy is mediated by the male-specific lethal (MSL) complex consisting of five proteins and two non-coding RNAs, roX1 and roX2. After an initial sequence-dependent recognition by the MSL complex of 150–300 high affinity sites, the spread to the majority of the X-linked genes depends on local MSL-complex concentration and active transcription. We have explored whether any additional RNA species are associated with the MSL complex. No additional roX RNA species were found, but a strong association was found between a spliced and poly-adenylated msl2 RNA and the MSL complex. Based on our results, we propose a model in which a non-chromatin-associated partial or complete MSL-complex titrates newly transcribed msl2 mRNA and thus regulates the amount of available MSL complex by feedback. This represents a novel mechanism in chromatin structure regulation. PMID:21551218

  11. Nuclear and plastid haplotypes suggest rapid diploid and polyploid speciation in the N Hemisphere Achillea millefolium complex (Asteraceae

    Directory of Open Access Journals (Sweden)

    Guo Yan-Ping

    2012-01-01

    Full Text Available Abstract Background Species complexes or aggregates consist of a set of closely related species often of different ploidy levels, whose relationships are difficult to reconstruct. The N Hemisphere Achillea millefolium aggregate exhibits complex morphological and genetic variation and a broad ecological amplitude. To understand its evolutionary history, we study sequence variation at two nuclear genes and three plastid loci across the natural distribution of this species complex and compare the patterns of such variations to the species tree inferred earlier from AFLP data. Results Among the diploid species of A. millefolium agg., gene trees of the two nuclear loci, ncpGS and SBP, and the combined plastid fragments are incongruent with each other and with the AFLP tree likely due to incomplete lineage sorting or secondary introgression. In spite of the large distributional range, no isolation by distance is found. Furthermore, there is evidence for intragenic recombination in the ncpGS gene. An analysis using a probabilistic model for population demographic history indicates large ancestral effective population sizes and short intervals between speciation events. Such a scenario explains the incongruence of the gene trees and species tree we observe. The relationships are particularly complex in the polyploid members of A. millefolium agg. Conclusions The present study indicates that the diploid members of A. millefolium agg. share a large part of their molecular genetic variation. The findings of little lineage sorting and lack of isolation by distance is likely due to short intervals between speciation events and close proximity of ancestral populations. While previous AFLP data provide species trees congruent with earlier morphological classification and phylogeographic considerations, the present sequence data are not suited to recover the relationships of diploid species in A. millefolium agg. For the polyploid taxa many hybrid links and

  12. Crystallization of hepatocyte nuclear factor 4α (HNF4α) in complex with the HNF1α promoter element

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Peng; Liu, Jianguo; Melikishvili, Manana; Fried, Michael G.; Chi, Young-In, E-mail: ychi@uky.edu [Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY 40536 (United States)

    2008-04-01

    Sample preparation, characterization, crystallization and preliminary X-ray analysis are reported for the HNF4α–DNA binary complex. Hepatocyte nuclear factor 4α (HNF4α) is a member of the nuclear receptor superfamily that plays a central role in organ development and metabolic functions. Mutations on HNF4α cause maturity-onset diabetes of the young (MODY), a dominant monogenic cause of diabetes. In order to understand the molecular mechanism of promoter recognition and the molecular basis of disease-causing mutations, the recombinant HNF4α DNA-binding domain was prepared and used in a study of its binding properties and in crystallization with a 21-mer DNA fragment that contains the promoter element of another MODY gene, HNF1α. The HNF4α protein displays a cooperative and specific DNA-binding activity towards its target gene-recognition elements. Crystals of the complex diffract to 2.0 Å using a synchrotron-radiation source under cryogenic (100 K) conditions and belong to space group C2, with unit-cell parameters a = 121.63, b = 35.43, c = 70.99 Å, β = 119.36°. A molecular-replacement solution has been obtained and structure refinement is in progress. This structure and the binding studies will provide the groundwork for detailed functional and biochemical studies of the MODY mutants.

  13. Ultra-high temperature steam corrosion of complex silicates for nuclear applications: A computational study

    Science.gov (United States)

    Rashkeev, Sergey N.; Glazoff, Michael V.; Tokuhiro, Akira

    2014-01-01

    Stability of materials under extreme conditions is an important issue for safety of nuclear reactors. Presently, silicon carbide (SiC) is being studied as a cladding material candidate for fuel rods in boiling-water and pressurized water-cooled reactors (BWRs and PWRs) that would substitute or modify traditional zircaloy materials. The rate of corrosion of the SiC ceramics in hot vapor environment (up to 2200 °C) simulating emergency conditions of light water reactor (LWR) depends on many environmental factors such as pressure, temperature, viscosity, and surface quality. Using the paralinear oxidation theory developed for ceramics in the combustion reactor environment, we estimated the corrosion rate of SiC ceramics under the conditions representing a significant power excursion in a LWR. It was established that a significant time - at least 100 h - is required for a typical SiC braiding to significantly degrade even in the most aggressive vapor environment (with temperatures up to 2200 °C) which is possible in a LWR at emergency condition. This provides evidence in favor of using the SiC coatings/braidings for additional protection of nuclear reactor rods against off-normal material degradation during power excursions or LOCA incidents. Additionally, we discuss possibilities of using other silica based ceramics in order to find materials with even higher corrosion resistance than SiC. In particular, we found that zircon (ZrSiO4) is also a very promising material for nuclear applications. Thermodynamic and first-principles atomic-scale calculations provide evidence of zircon thermodynamic stability in aggressive environments at least up to 1535 °C.

  14. Competition between radiative and strong force decay

    Science.gov (United States)

    Tabor, Samuel

    2017-01-01

    For nuclear states unbound to neutron decay, radiative emission is often assumed to not dominate over neutron decay mediated by the far stronger strong interaction, except for very low neutron energies and high angular momentum barriers. Recent experimental investigations of 19O and 27 Mg populated in heavy-ion fusion-evaporation reactions have revealed predominantly gamma decays from a number of states unbound to neutron decay by up to 2 MeV. In most cases the angular momentum barrier is not sufficient to inhibit neutron decay enough to allow E-M decay with widths of up to an eV or so to win. Other inhibitions to particle decay, including low spectroscopic factors, will be discussed. Supported in part by NSF Grant No. 1401574.

  15. Theoretical study of trivalent element complexes for the nuclear waste reprocessing; Etude theorique de complexes d'elements f trivalents pour le retraitement des dechets nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Petit, L

    2007-10-15

    Current energetic and environmental concerns have made the nuclear waste reprocessing to be a major issue in numerous countries. One avenue to treat nuclear spent fuel requires separating selectively trivalent minor actinides An (Am{sup 3+}, Cm{sup 3+}) from lanthanides Ln. In this regard, nitrogen extractants are under study. Their selectivity toward actinides is still unclear, but could be the result of enhanced covalency effects with trivalent minor actinides with respect to lanthanides (III). In this thesis, we have performed DFT calculations (Density Functional Theory) to study covalency effects within the actinide-ligand bond, following three main axes of research: advanced study of the nature of the chemical bonding, spectroscopic characterization of covalency, and preliminary tests of ab initio molecular dynamics for future calculations in solvent. Methods that are not regularly applied to trivalent actinides complexes have been used: topological methods, TDDFT, LDDFT, ab initio molecular dynamics. We have managed to show that the selectivity of the BTP ligand - the most effective An/Ln extractant to date - comes at least for a part from stronger covalency effects within the An-BTP bond with respect to the Ln-BTP bond, which has never been proved before. (author)

  16. Super-resolution imaging visualizes the eightfold symmetry of gp210 proteins around the nuclear pore complex and resolves the central channel with nanometer resolution

    NARCIS (Netherlands)

    Löschberger, A.; Van de Linde, S.; Debauvalle, M.C.; Rieger, B.; Heilemann, M.; Krohne, G.; Sauer, M.

    2012-01-01

    One of the most complex molecular machines of cells is the nuclear pore complex (NPC), which controls all trafficking of molecules in and out of the nucleus. Because of their importance for cellular processes such as gene expression and cytoskeleton organization, the structure of NPCs has been studi

  17. Unique formation of two high-nuclearity metallamacrocycles from a mononuclear complex [Zn(dmpzdtc)2] (dmpzdtc=3,5-dimethylpyrazole-1-dithiocarboxylate) via CS2 elimination.

    Science.gov (United States)

    Li, Hong-Xi; Wu, Hua-Zhou; Zhang, Wen-Hua; Ren, Zhi-Gang; Zhang, Yong; Lang, Jian-Ping

    2007-12-21

    Dissolution of a mononuclear complex [Zn(dmpzdtc)2] in BrCH2CH2Br or DMF saturated with water followed by CS2 elimination led to the formation of two unique high-nuclearity metallamacrocyclic complexes, [Zn4(micro-dmpz)6(micro-OH)2]2 and [Zn4(micro-dmpz)6(micro-OH)2]4.

  18. Genome-assisted development of nuclear intergenic sequence markers for entomopathogenic fungi of the Metarhizium anisopliae species complex.

    Science.gov (United States)

    Kepler, R M; Rehner, S A

    2013-03-01

    Entomopathogenic fungi in the genus Metarhizium are useful for biological control programmes against economically important arthropod pests worldwide. However, understanding the true diversity and ecology of these organisms is hampered by convergent morphologies between species. The application of molecular techniques has enabled greater resolution of species than allowed by morphology alone. In particular, the commonly used biocontrol agent M. anisopliae was found to be a species complex composed of nine species. This prior work was conducted with commonly used markers in fungal phylogenetics (BTUB, RPB1, RPB2 and TEF), which likely under-represent diversity in the M. anisopliae complex. Using sequence data from nuclear genomes of M. acridum and M. robertsii we identified regions of conserved gene synteny and developed primers to amplify intergenic regions of seven loci. Using ex-type and authenticated tissue specimens for species in the M. anisopliae complex, we demonstrate that sequence data derived from intergenic loci is more variable and phylogenetically informative than previously available markers. These new markers will facilitate investigations at or below the species level for the M. anisopliae complex. The method of marker development employed here should be extendable to any group with sufficiently divergent genome data available.

  19. The complex nature of the nuclear star cluster in FCC 277

    CERN Document Server

    Lyubenova, Mariya; Cote, Patrick; Kuntschner, Harald; van de Ven, Glenn; Ferrarese, Laura; Jordan, Andres; Infante, Leopoldo

    2013-01-01

    Recent observations have shown that compact nuclear star clusters (NSCs) are present in up to 80% of galaxies. However, detailed studies of their dynamical and chemical properties are confined mainly to spiral galaxy hosts, where they are more easily observed. In this paper we present our study of the NSC in FCC 277, a nucleated elliptical galaxy in the Fornax cluster. We use a combination of adaptive optics assisted near-infrared integral field spectroscopy, Hubble Space Telescope imaging, and literature long slit data. We show that while the NSC does not appear to rotate within our detection limit of ~6 km/s, rotation is detected at larger radii, where the isophotes appear to be disky, suggesting the presence of a nuclear disk. We also observe a distinct central velocity dispersion drop that is indicative of a dynamically cold rotating sub-system. Following the results of orbit-based dynamical modelling, co-rotating as well as counter-rotating stellar orbits are simultaneously needed to reproduce the observ...

  20. Multi-nuclear silver(I) and copper(I) complexes: a novel bonding mode for bispyridylpyrrolides.

    Science.gov (United States)

    Hu, Xiao-Hui; Liang, Yan; Li, Chen; Yi, Xiao-Yi

    2014-02-14

    Reaction of deprotonated 2,5-bis(2'-pyridyl)pyrrole (HPDPH) with AgOTf (where OTf(-) = triflato) in THF readily yields a yellow triangular Ag3 complex [(PDPH)Ag]3 (1), of which the av. AgAg distance is 2.902 Å. A mixture of HPDPH and AgOTf reacts with PPh3 to afford a linear Ag3 complex [Ag{(PDPH)Ag(PPh3)}2](OTf) (2·OTf), whereas it reacts with diethyl phosphite in the presence of Li[N(SiMe3)2] to yield a di-nuclear complex Li2[(PDPH)Ag2{P(O)(OEt)2}2](OTf) (Li2·3·OTf). In 2, the terminal Ag atoms are three coordinate containing one phosphorous atom from PPh3 and two nitrogen atoms of the PDPH ligand. The center Ag atom is only two coordinate, binding to the residued pyridyl N atom of the PDPH ligand. In 3, two silver atoms are bridged by one PDPH ligand. Treatment of PDPH with CuCl in the presence of NaH afforded a heterobimetallic copper-sodium complex [Cu(PDPH)2Na(thf)2] (4). The PDPH ligand in 1-4 is nonplanar, with torsion angles between pyridine and pyrrole rings in the range of 15.8-38.3°. The argentophilic interactions, π∙∙∙π stacking, and weak interaction of Ag∙∙∙C(aromatic) are observed in these complexes. Interestingly, treatment of the analogous 2,5-bis(6'-bromo-2'-pyridyl)pyrrole (HPDPBr) with AgOTf affords a di-nuclear complex [(HPDPBr)Ag]2(OTf)2 (5·(OTf)2). Its HPDPBr ligands coordinate to Ag atoms in a head-to-head fashion, and two protonated pyrrole linkages reside in the anti-parallel direction and are non-coordinating. Short AgBr distances of 3.255-3.390 Å are observed.

  1. Study of the Production Mechanisms and Decay Properties of Charmed Particles Observed in Nuclear Emulsions Coupled to the NA14 Spectrometer

    CERN Multimedia

    2002-01-01

    The aims of this test experiment are: \\item a)~~~~to check the expected improvement in scanning speed and efficiency, due to the use of the microstrip vertex detector of the NA14 set-up and to the help of automated microscopes; \\item b)~~~~to evaluate the enrichment factor in the charmed event content of the sample to be searched, due to the particle identification power and the vertex detector of NA14; \\item c)~~~~to collect some 100 pairs of charmed particles, produced and decaying in emulsion, which would allow a comparison with the results from the WA58 experiment, in particular about the possible energy dependence of the production mechanism of associated @L^c|+~$\\bar{D}$. \\end{enumerate} The incident beam will consist of tagged photons between 70 and 150-200~GeV.

  2. The decay of /sup 185/Hg low-spin states in /sup 185/Au as a probe of the nuclear models

    CERN Document Server

    Bourgeois, C; Kilcher, P; Roussière, B; Sauvage-Letessier, J

    1981-01-01

    The /sup 185/Au has been studied from the beta /sup +//EC decay of /sup 185m+g/Hg using the ISOCELE facility. Conversion electron measurements have been performed by means of a semi-circular magnetic spectrograph: new low-energy transitions have been observed. A 330 keV very converted transition has also been found. Its existence is discussed. In addition to the usual states observed in heavier gold isotopes, numerous negative-parity low-spin states have been located. The experimental states corresponding to a prolate shaped nucleus are compared with those extracted from an 'axial rotor+quasi-particle' coupling model. They could be identified with two state families, the first one arising from the h9/2+f5/2 sub-shells, the second from the p3/2+f7/2 sub-shells. (12 refs).

  3. Lanthanum-139 nuclear magnetic resonance studies of polyaminocarboxylate-lanthanum complexes in aqueous solution

    Science.gov (United States)

    Geraldes, Carlos F. G. C.; Dean Sherry, A.

    Several complexes of La(III) with aminocarboxylate and polyaminocarboxylate ligands in aqueous solution have been studied using 139La chemical-shift and linewidth measurements. The ligand-induced shifts of the 139La NMR resonance were found to depend, at least to first order, on additive substituent contributions, and were empirically related to the number and type of coordinated oxygen and nitrogen atoms. A previously proposed relationship between the number of coordinated carboxylate oxygen atoms and observed 139La shifts does not seem to hold for the polyaminocarboxylate complexes and we propose a new empirical relationship which allows an accurate prediction of the number and types of ligand donors in these systems. The 139La linewidths also provide qualitative information about the symmetry of each La 3+ chelate. The results show that 139La NMR can be a powerful technique for elucidating the structure and dynamics of lanthanide complexes in solution.

  4. The formation of hydrophilic Np(IV) complexes and their potential application in nuclear fuel reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    May, I.; Taylor, R.J.; Brown, G. [British Nuclear Fuels Ltd., Sellafield (United Kingdom)

    1998-06-12

    A series of organic ligands have been screened for their effectiveness as complexants for Np(IV) in a neptunium rejection stage of an advanced PUREX process. Four of these species, formohydroxamic acid, acetohydroxamic acid, glycolic acid and pyruvic acid, readily form hydrophilic complexes with Np(IV) and can strip the actinide from 30% TBP/OK (30% tributylphosphate in odourless kerosene) into nitric acid. Near infra-red spectroscopy has been used to monitor Np(IV) complexation in nitric acid. Distribution experiments have been undertaken between nitric acid and 30% TBP/OK to examine the effect of ligand and nitric acid concentration on Np(IV) stripping. Finally, it has been shown that the extractability of U(VI) is unaffected by the presence of these ligands and all can be used to selectively strip Np(IV) from a U(VI) product stream in an advanced PUREX process. (orig.) 11 refs.

  5. Simulation of decay processes and radiation transport times in radioactivity measurements

    Science.gov (United States)

    García-Toraño, E.; Peyres, V.; Bé, M.-M.; Dulieu, C.; Lépy, M.-C.; Salvat, F.

    2017-04-01

    The Fortran subroutine package PENNUC, which simulates random decay pathways of radioactive nuclides, is described. The decay scheme of the active nuclide is obtained from the NUCLEIDE database, whose web application has been complemented with the option of exporting nuclear decay data (possible nuclear transitions, branching ratios, type and energy of emitted particles) in a format that is readable by the simulation subroutines. In the case of beta emitters, the initial energy of the electron or positron is sampled from the theoretical Fermi spectrum. De-excitation of the atomic electron cloud following electron capture and internal conversion is described using transition probabilities from the LLNL Evaluated Atomic Data Library and empirical or calculated energies of released X rays and Auger electrons. The time evolution of radiation showers is determined by considering the lifetimes of nuclear and atomic levels, as well as radiation propagation times. Although PENNUC is designed to operate independently, here it is used in conjunction with the electron-photon transport code PENELOPE, and both together allow the simulation of experiments with radioactive sources in complex material structures consisting of homogeneous bodies limited by quadric surfaces. The reliability of these simulation tools is demonstrated through comparisons of simulated and measured energy spectra from radionuclides with complex multi-gamma spectra, nuclides with metastable levels in their decay pathways, nuclides with two daughters, and beta plus emitters.

  6. Reactive surface organometallic complexes observed using dynamic nuclear polarization surface enhanced NMR spectroscopy

    KAUST Repository

    Pump, Eva

    2016-08-15

    Dynamic Nuclear Polarization Surface Enhanced NMR Spectroscopy (DNP SENS) is an emerging technique that allows access to high-sensitivity NMR spectra from surfaces. However, DNP SENS usually requires the use of radicals as an exogenous source of polarization, which has so far limited applications for organometallic surface species to those that do not react with the radicals. Here we show that reactive surface species can be studied if they are immobilized inside porous materials with suitably small windows, and if bulky nitroxide bi-radicals (here TEKPol) are used as the polarization source and which cannot enter the pores. The method is demonstrated by obtaining significant DNP enhancements from highly reactive complelxes [(equivalent to Si-O-)W(Me)(5)] supported on MCM-41, and effects of pore size (6.0, 3.0 and 2.5 nm) on the performance are discussed.

  7. Formation of high nuclearity mixed-valent polyoxovanadates in the presence of copper amine complexes

    Indian Academy of Sciences (India)

    Jency Thomas; Sanjeev Sharma; S E Lofland; K V Ramanujachary; A Ramanana

    2006-01-01

    Two new Müller-type clusters, a one-dimensional solid {Cu()2}4[Cl ⊂ V15O36]$\\cdot$12H2O 1, and a three-dimensional solid {Cu()2}4[Cl ⊂ V18O42]$\\cdot$12H2O 2, have been synthesised by employing identical hydrothermal conditions except varying the nature of organic diamine. 1 crystallised in a chiral space group 212121 with = 12.757(1), = 18.927(2) and = 28.590(3) Å, and = 4. 2 crystallised in a tetragonal system with space group 4/, = 15.113(1) and = 18.542(3) Å, and = 2. Mixed-valent vanadium ions in structures 1 and 2 have been established both by magnetisation and bond-length bondvalence measurements. Chemistry of formation of high nuclearity polyoxovanadate clusters is discussed.

  8. Statistical description of complex nuclear phases in supernovae and proto-neutron stars

    Science.gov (United States)

    Raduta, Ad. R.; Gulminelli, F.

    2010-12-01

    We develop a phenomenological statistical model for dilute star matter at finite temperature, in which free nucleons are treated within a mean-field approximation and nuclei are considered to form a loosely interacting cluster gas. Its domain of applicability, that is, baryonic densities ranging from about ρ>108 g/cm3 to normal nuclear density, temperatures between 1 and 20 MeV, and proton fractions between 0.5 and 0, makes it suitable for the description of baryonic matter produced in supernovae explosions and proto-neutron stars. The first finding is that, contrary to the common belief, the crust-core transition is not first order, and for all subsaturation densities matter can be viewed as a continuous fluid mixture between free nucleons and massive nuclei. As a consequence, the equations of state and the associated observables do not present any discontinuity over the whole thermodynamic range. We further investigate the nuclear matter composition over a wide range of densities and temperatures. At high density and temperature our model accounts for a much larger mass fraction bound in medium nuclei with respect to traditional approaches as Lattimer-Swesty, with sizable consequences on the thermodynamic quantities. The equations of state agree well with the presently used EOS only at low temperatures and in the homogeneous matter phase, while important differences are present in the crust-core transition region. The correlation among the composition of baryonic matter and neutrino opacity is finally discussed, and we show that the two problems can be effectively decoupled.

  9. Nuclear analytical chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D.; Forkman, B.; Persson, B.

    1984-01-01

    This book covers the general theories and techniques of nuclear chemical analysis, directed at applications in analytical chemistry, nuclear medicine, radiophysics, agriculture, environmental sciences, geological exploration, industrial process control, etc. The main principles of nuclear physics and nuclear detection on which the analysis is based are briefly outlined. An attempt is made to emphasise the fundamentals of activation analysis, detection and activation methods, as well as their applications. The book provides guidance in analytical chemistry, agriculture, environmental and biomedical sciences, etc. The contents include: the nuclear periodic system; nuclear decay; nuclear reactions; nuclear radiation sources; interaction of radiation with matter; principles of radiation detectors; nuclear electronics; statistical methods and spectral analysis; methods of radiation detection; neutron activation analysis; charged particle activation analysis; photon activation analysis; sample preparation and chemical separation; nuclear chemical analysis in biological and medical research; the use of nuclear chemical analysis in the field of criminology; nuclear chemical analysis in environmental sciences, geology and mineral exploration; and radiation protection.

  10. Crystal structure of the Xpo1p nuclear export complex bound to the SxFG/PxFG repeats of the nucleoporin Nup42p.

    Science.gov (United States)

    Koyama, Masako; Hirano, Hidemi; Shirai, Natsuki; Matsuura, Yoshiyuki

    2017-08-08

    Xpo1p (yeast CRM1) is the major nuclear export receptor that carries a plethora of proteins and ribonucleoproteins from the nucleus to cytoplasm. The passage of the Xpo1p nuclear export complex through nuclear pore complexes (NPCs) is facilitated by interactions with nucleoporins (Nups) containing extensive repeats of phenylalanine-glycine (so-called FG repeats), although the precise role of each Nup in the nuclear export reaction remains incompletely understood. Here we report structural and biochemical characterization of the interactions between the Xpo1p nuclear export complex and the FG repeats of Nup42p, a nucleoporin localized at the cytoplasmic face of yeast NPCs and has characteristic SxFG/PxFG sequence repeat motif. The crystal structure of Xpo1p-PKI-Nup42p-Gsp1p-GTP complex identified three binding sites for the SxFG/PxFG repeats on HEAT repeats 14-20 of Xpo1p. Mutational analyses of Nup42p showed that the conserved serines and prolines in the SxFG/PxFG repeats contribute to Xpo1p-Nup42p binding. Our structural and biochemical data suggest that SxFG/PxFG-Nups such as Nup42p and Nup159p at the cytoplasmic face of NPCs provide high-affinity docking sites for the Xpo1p nuclear export complex in the terminal stage of NPC passage and that subsequent disassembly of the nuclear export complex facilitates recycling of free Xpo1p back to the nucleus. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

  11. SOD mimetic activity and antiproliferative properties of a novel tetra nuclear copper (II) complex.

    Science.gov (United States)

    Weintraub, Sagiv; Moskovitz, Yoni; Fleker, Ohad; Levy, Ariel R; Meir, Aviv; Ruthstein, Sharon; Benisvy, Laurent; Gruzman, Arie

    2015-12-01

    The search for novel anticancer therapeutic agents is an urgent and important issue in medicinal chemistry. Here, we report on the biological activity of the copper-based bioinorganic complex Cu4 (2,4-di-tert-butyl-6-(1H-imidazo- [1, 10] phenanthrolin-2-yl)phenol)4]·10 CH3CN (2), which was tested in rat L6 myotubes, mouse NSC-34 motor neurone-like cells, and HepG-2 human liver carcinoma. Upon 96 h incubation, 2 exhibited a significant cytotoxic effect on all three types of cells via activation of two cell death mechanisms (apoptosis and necrosis). Complex 2 exhibited better potency and efficacy than the canonical cytotoxic drug cisplatin. Moreover, during shorter incubations, complex 2 demonstrated a significant SOD mimetic activity, and it was more effective and more potent than the well-known SOD mimetic TEMPOL. In addition, complex 2 was able to interact with DNA and, cleave DNA in the presence of sodium ascorbate. This study shows the potential of using polynuclear redox active compounds for developing novel anticancer drugs through SOD-mimetic redox pathways.

  12. Chinese Nuclear Science Basic Data Base (CNSBDB)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new research project on "Development of the Chinese Nuclear Science Basic Database (CNSBDB)for Fundamental Researches of Nuclear Physics and Interrelated Subjects, and Requirements of NuclearPower and Nuclear Technologies Application" has been commenced. The CNSBDB contains thefollowing eight segments: 1) Information on Nuclear Science (INFO); 2) Nuclear Structure Data Base(NSDB); 3) Nuclear Decay Data Base (NDDB); 4) Nuclear Reaction Data Base (NRDB); 5) Nuclear

  13. Suppressed Charmed B Decay

    Energy Technology Data Exchange (ETDEWEB)

    Snoek, Hella Leonie [Vrije Univ., Amsterdam (Netherlands)

    2009-06-02

    This thesis describes the measurement of the branching fractions of the suppressed charmed B0 → D*- a0+ decays and the non-resonant B0 → D*- ηπ+ decays in approximately 230 million Υ(4S) → B$\\bar{B}$ events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B0 → D*- a{sub 0}+ decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10-6. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle γ, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle γ can be performed using the decays of neutral B mesons. The B0 → D*- a0+ decay is sensitive to the angle γ and, in comparison to the current decays that are being employed, could significantly

  14. eEF1A Mediates the Nuclear Export of SNAG-Containing Proteins via the Exportin5-Aminoacyl-tRNA Complex

    Directory of Open Access Journals (Sweden)

    José Manuel Mingot

    2013-11-01

    Full Text Available Exportin5 mediates the nuclear export of double-stranded RNAs, including pre-microRNAs, adenoviral RNAs, and tRNAs. When tRNAs are aminoacylated, the Exportin5-aminoacyl (aa-tRNA complex recruits and coexports the translation elongation factor eEF1A. Here, we show that eEF1A binds to Snail transcription factors when bound to their main target, the E-cadherin promoter, facilitating their export to the cytoplasm in association with the aa-tRNA-Exportin5 complex. Snail binds to eEF1A through the SNAG domain, a protein nuclear export signal present in several transcription factor families, and this binding is regulated by phosphorylation. Thus, we describe a nuclear role for eEF1A and provide a mechanism for protein nuclear export that attenuates the activity of SNAG-containing transcription factors.

  15. eEF1A mediates the nuclear export of SNAG-containing proteins via the Exportin5-aminoacyl-tRNA complex.

    Science.gov (United States)

    Mingot, José Manuel; Vega, Sonia; Cano, Amparo; Portillo, Francisco; Nieto, M Angela

    2013-11-14

    Exportin5 mediates the nuclear export of double-stranded RNAs, including pre-microRNAs, adenoviral RNAs, and tRNAs. When tRNAs are aminoacylated, the Exportin5-aminoacyl (aa)-tRNA complex recruits and coexports the translation elongation factor eEF1A. Here, we show that eEF1A binds to Snail transcription factors when bound to their main target, the E-cadherin promoter, facilitating their export to the cytoplasm in association with the aa-tRNA-Exportin5 complex. Snail binds to eEF1A through the SNAG domain, a protein nuclear export signal present in several transcription factor families, and this binding is regulated by phosphorylation. Thus, we describe a nuclear role for eEF1A and provide a mechanism for protein nuclear export that attenuates the activity of SNAG-containing transcription factors.

  16. Spectroscopy of element 115 decay chains

    Energy Technology Data Exchange (ETDEWEB)

    Rudolph, Dirk [Lund University, Sweden; Forsberg, U. [Lund University, Sweden; Golubev, P. [Lund University, Sweden; Sarmiento, L. G. [Lund University, Sweden; Yakushev, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Andersson, L.-L. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Di Nitto, A. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Duehllmann, Ch. E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Gates, J. M. [Lawrence Berkeley National Laboratory (LBNL); Gregorich, K. E. [Lawrence Berkeley National Laboratory (LBNL); Gross, Carl J [ORNL; Hessberger, F. P. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Herzberg, R.-D [University of Liverpool; Khuyagbaatar, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Kratz, J. V. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Rykaczewski, Krzysztof Piotr [ORNL; Schaedel, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Aberg, S. [Lund University, Sweden; Ackermann, D. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Block, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Brand, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Carlsson, B. G. [Lund University, Sweden; Cox, D. [University of Liverpool; Derkx, X. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Eberhardt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Even, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Fahlander, C. [Lund University, Sweden; Gerl, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Jaeger, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kindler, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Krier, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kojouharov, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kurz, N. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Lommel, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mistry, A. [University of Liverpool; Mokry, C. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Nitsche, H. [Lawrence Berkeley National Laboratory (LBNL); Omtvedt, J. P. [Paul Scherrer Institut, Villigen, Switzerland; Papadakis, P. [University of Liverpool; Ragnarsson, I. [Lund University, Sweden; Runke, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schaffner, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schausten, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Thoerle-Pospiech, P. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Torres, T. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Traut, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Trautmann, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Tuerler, A. [Paul Scherrer Institut, Villigen, Switzerland; Ward, A. [University of Liverpool; Ward, D. E. [Lund University, Sweden; Wiehl, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany

    2013-01-01

    A high-resolution a, X-ray and -ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fu r Schwerionenforschung. Thirty correlated a-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. The data includes first candidates of fingerprinting the decay step Mt --> Bh with characteristic X rays. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte-Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

  17. Using mitogenomic and nuclear ribosomal sequence data to investigate the phylogeny of the Xiphinema americanum species complex.

    Directory of Open Access Journals (Sweden)

    Inga A Zasada

    Full Text Available Nematodes within the Xiphinema americanum species complex are economically important because they vector nepoviruses which cause considerable damage to a variety of agricultural crops. The taxonomy of X. americanum species complex is controversial, with the number of putative species being the subject of debate. Accurate phylogenetic knowledge of this group is highly desirable as it may ultimately reveal genetic differences between species. For this study, nematodes belonging to the X. americanum species complex, including potentially mixed species populations, were collected from 12 geographically disparate locations across the U.S. from different crops and in varying association with nepoviruses. At least four individuals from each population were analyzed. A portion of the 18S nuclear ribosomal DNA (rDNA gene was sequenced for all individuals while the internal transcribed spacer region 1 (ITS1 of rDNA was cloned and 2 to 6 clones per individual were sequenced. Mitochondrial genomes for numerous individuals were sequenced in parallel using high-throughput DNA sequencing (HTS technology. Phylogenetic analysis of the 18S rDNA revealed virtually identical sequences across all populations. Analysis of ITS1 rDNA sequences revealed several well-supported clades, with some degree of congruence with geographic location and viral transmission, but also numerous presumably paralogous sequences that failed to form clades with other sequences from the same population. Analysis of mitochondrial DNA (mtDNA indicated the presence of three distinct monophyletic clades of X. americanum species complex nematodes. Two clades contained nematodes found in association with nepovirus and the third contained divergent mtDNA sequences from three nematode populations from the western U.S. where nepovirus was absent. The inherent heterogeneity in ITS1 rDNA sequence data and lack of informative sites in 18S rDNA analysis suggests that mtDNA may be more useful in sorting

  18. Using mitogenomic and nuclear ribosomal sequence data to investigate the phylogeny of the Xiphinema americanum species complex.

    Science.gov (United States)

    Zasada, Inga A; Peetz, Amy; Howe, Dana K; Wilhelm, Larry J; Cheam, Daravuth; Denver, Dee R; Smythe, Ashleigh B

    2014-01-01

    Nematodes within the Xiphinema americanum species complex are economically important because they vector nepoviruses which cause considerable damage to a variety of agricultural crops. The taxonomy of X. americanum species complex is controversial, with the number of putative species being the subject of debate. Accurate phylogenetic knowledge of this group is highly desirable as it may ultimately reveal genetic differences between species. For this study, nematodes belonging to the X. americanum species complex, including potentially mixed species populations, were collected from 12 geographically disparate locations across the U.S. from different crops and in varying association with nepoviruses. At least four individuals from each population were analyzed. A portion of the 18S nuclear ribosomal DNA (rDNA) gene was sequenced for all individuals while the internal transcribed spacer region 1 (ITS1) of rDNA was cloned and 2 to 6 clones per individual were sequenced. Mitochondrial genomes for numerous individuals were sequenced in parallel using high-throughput DNA sequencing (HTS) technology. Phylogenetic analysis of the 18S rDNA revealed virtually identical sequences across all populations. Analysis of ITS1 rDNA sequences revealed several well-supported clades, with some degree of congruence with geographic location and viral transmission, but also numerous presumably paralogous sequences that failed to form clades with other sequences from the same population. Analysis of mitochondrial DNA (mtDNA) indicated the presence of three distinct monophyletic clades of X. americanum species complex nematodes. Two clades contained nematodes found in association with nepovirus and the third contained divergent mtDNA sequences from three nematode populations from the western U.S. where nepovirus was absent. The inherent heterogeneity in ITS1 rDNA sequence data and lack of informative sites in 18S rDNA analysis suggests that mtDNA may be more useful in sorting out the

  19. Interactions of cullin3/KCTD5 complexes with both cytoplasmic and nuclear proteins: Evidence for a role in protein stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Rutz, Natalja; Heilbronn, Regine; Weger, Stefan, E-mail: stefan.weger@charite.de

    2015-08-28

    Based on its specific interaction with cullin3 mediated by an N-terminal BTB/POZ homologous domain, KCTD5 has been proposed to function as substrate adapter for cullin3 based ubiquitin E3 ligases. In the present study we tried to validate this hypothesis through identification and characterization of additional KCTD5 interaction partners. For the replication protein MCM7, the zinc finger protein ZNF711 and FAM193B, a yet poorly characterized cytoplasmic protein, we could demonstrate specific interaction with KCTD5 both in yeast two-hybrid and co-precipitation studies in mammalian cells. Whereas trimeric complexes of cullin3 and KCTD5 with the respective KCTD5 binding partner were formed, KCTD5/cullin3 induced polyubiquitylation and/or proteasome-dependent degradation of these binding partners could not be demonstrated. On the contrary, KCTD5 or Cullin3 overexpression increased ZNF711 protein stability. - Highlights: • KCTD5 nuclear translocation depends upon M phase and protein oligomerization. • Identification of MCM7, ZNF711 and FAM193 as KCTD5 interaction partners. • Formation of trimeric complexes of KCTD5/cullin3 with MCM7, ZNF711 and FAM193B. • KCTD5 is not involved in polyubiquitylation of MCM7 replication factor. • The KCTD5/cullin3 complex stabilizes ZNF711 transcription factor.

  20. Chromium-53 nuclear magnetic resonance studies of pentacarbonylchromium-carbene complexes

    Energy Technology Data Exchange (ETDEWEB)

    Hafner, A.; Hegedus, L.S.; DeWeck, G.; Hawkins, B. (Colorado State Univ., Fort Collins (USA)); Doetz, K.H. (Universitaet Hans-Meerweinstrasse, Marburg (Germany, F.R.))

    1988-12-07

    The {sup 53}Cr NMR spectra of 46 chromium-carbene complexes were recorded, and chemical shift and line width data are reported, along with associated infrared, uv-visible, and {sup 13}C NMR spectroscopic data. The {sup 53}Cr chemical shifts correlated very well with the donor-acceptor properties of the carbene ligand and were quite sensitive to steric influences on efficiency of {pi}-overlap of the heteroatom with the carbene carbon. There was no correlation of {delta}({sup 53}Cr) with reactivity toward imines to form {beta}-lactams, but line width appeared to be related to reactivity. Preliminary attempts to utilize {sup 53}Cr NMR data to direct synthetic utilization of chromium-carbene complexes are reported. 5 refs., 49 figs., 1 tab.

  1. Potential Impact of Atmospheric Releases at Russian Far East Nuclear Submarine Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Parker, F.; Mahura, A.; Compton, K.; Brown, K.; Takano, M.; Novikov, V.; Soerensen, J. H.; Baklanov, A.

    2003-02-25

    An ''Assessment of the Impact of Russian Nuclear Fleet Operations on Far Eastern Coastal Regions'' is being performed as part of the Radiation Safety of the Biosphere Project (RAD) of the International Institute for Applied Systems Analysis (IIASA) of Laxenburg, Austria. To the best of our knowledge, this is the first comprehensive unclassified analysis of the potential impact of accidents at the Russian Far East nuclear submarine sites near Vladivostok and Petropavlovsk. We have defined the situation there based upon available information and studies commissioned by RAD in collaboration with Russian research institutes including Russian Research Center-''Kurchatov Institute'', Institute of Northern Environmental Problems and Lazurit Central Design Bureau. Further, in our original work, some in collaboration with the staff of the Danish Meteorological Institute (DMI) and members of the Japan Atomic Energy Research Institute, we have calculated the nuclide trajectories from these sites in the atmospheric boundary layer, less than 1.5 kilometers high, and determined their probability of crossing any of the nearby countries as well as Asiatic Russia. We have further determined the concentrations in each of these crossings as well as the total, dry and wet depositions of nuclides on these areas. Finally, we have calculated the doses to the Japanese Island population from typical winter airflow patterns (those most likely to cross the Islands in the minimum times), strong north winds, weak north winds and cyclonic winds for conditions similar to the Chazhma Bay criticality accident (fresh fuel) and for a criticality accident for the same type of reactor with fuel being withdrawn (spent fuel). The maximum individual committed dosages were less than 2 x 10-7 and 2 x 10-3 mSv, respectively. The long-term external doses by radionuclides deposited on the ground and the internal doses by consumption of foods were not evaluated as it is

  2. Mn(II) complexes of different nuclearity: synthesis, characterization and catecholase-like activity.

    Science.gov (United States)

    Chakraborty, Prateeti; Majumder, Ishani; Banu, Kazi Sabnam; Ghosh, Bipinbihari; Kara, Hulya; Zangrando, Ennio; Das, Debasis

    2016-01-14

    Two "end-off" compartmental ligands, 2-formyl-4-chloro-6-N-ethylmorpholine-iminomethyl-phenol (HL1) and 2-formyl-4-methyl-6-N-ethylpyrrolidine-iminomethyl-phenol (HL2) have been designed and three complexes of Mn(ii), one mono-, one di- and a polynuclear, namely Mn(L1)(SCN)2(H2O)] (), [Mn2(L1)(OAc)2](BPh4)] (), and [Mn2(L2)(OAc)2(dca)]n () have been synthesized and structurally characterized. Variable temperature magnetic studies of and have been performed and data analyses reveal that Mn centers are antiferromagnetic coupled with J = -9.15 cm(-1) and J = -46.89, respectively. Catecholase activity of all the complexes has been investigated using 3,5-di-tert-butyl catechol (3,5-DTBC). All are highly active and the activity order on the basis of the kcat value is > > . In order to unveil whether the metal centered redox participation or the radical pathway is responsible for the catecholase-like activity of the complexes, detailed EPR and cyclic voltammetric (CV) studies have been performed. In addition to the six-line EPR spectrum characteristic to Mn(ii), an additional peak at g ∼ 2 is observed when the EPR study is done with the mixture of 3,5-DTBC and the catalyst, suggesting the formation of an organic radical, most likely ligand centered. The CV experiment with the mixture of 3,5-DTBC and the catalyst reveals ligand centered reduction rather than reduction of Mn(ii) to Mn(i). It is thus inferred that complexes show catecholase-like activity due to radical generation.

  3. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... to be followed after leaving the nuclear medicine facility. Through the natural process of radioactive decay, the ... Please note RadiologyInfo.org is not a medical facility. Please contact your physician with specific medical questions ...

  4. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... body. jaundice in newborns and older children. epilepsy . location, anatomy and function of the thyroid gland. top ... to be followed after leaving the nuclear medicine facility. Through the natural process of radioactive decay, the ...

  5. Why Model-Based Engineering and Manufacturing Makes Sense for the Plants and Laboratories of the Nuclear Weapon Complex

    Energy Technology Data Exchange (ETDEWEB)

    Franklin, K W; Howell, L N; Lewis, D G; Neugebauer, C A; O' Brien, D W; Schilling, S A

    2001-05-15

    The purpose of this White Paper is to outline the benefits we expect to receive from Model-Based Engineering and Manufacturing (MBE/M) for the design, analysis, fabrication, and assembly of nuclear weapons for upcoming Life Extension Programs (LEPs). Industry experiences with model-based approaches and the NNSA/DP investments and experiences, discussed in this paper, indicate that model-based methods can achieve reliable refurbished weapons for the stockpile with less cost and time. In this the paper, we list both general and specific benefits of MBE/M for the upcoming LEPs and the metrics for determining the success of model-based approaches. We also present some outstanding issues and challenges to deploying and achieving long-term benefit from the MBE/M. In conclusion, we argue that successful completion of the upcoming LEPs--with very aggressive schedule and funding restrictions--will depend on electronic model-based methods. We ask for a strong commitment from LEP managers throughout the Nuclear Weapons Complex to support deployment and use of MBE/M systems to meet their program needs.

  6. Atomic structure of the nuclear pore complex targeting domain of a Nup116 homologue from the yeast, Candida glabrata

    Energy Technology Data Exchange (ETDEWEB)

    Sampathkumar, Parthasarathy; Kim, Seung Joong; Manglicmot, Danalyn; Bain, Kevin T.; Gilmore, Jeremiah; Gheyi, Tarun; Phillips, Jeremy; Pieper, Ursula; Fernandez-Martinez, Javier; Franke, Josef D.; Matsui, Tsutomu; Tsuruta, Hiro; Atwell, Shane; Thompson, Devon A.; Emtage, J. Spencer; Wasserman, Stephen R.; Rout, Michael P.; Sali, Andrej; Sauder, J. Michael; Almo, Steven C.; Burley, Stephen K. (Einstein); (SLAC); (Rockefeller); (UCSF); (Lilly)

    2012-10-23

    The nuclear pore complex (NPC), embedded in the nuclear envelope, is a large, dynamic molecular assembly that facilitates exchange of macromolecules between the nucleus and the cytoplasm. The yeast NPC is an eightfold symmetric annular structure composed of {approx}456 polypeptide chains contributed by {approx}30 distinct proteins termed nucleoporins. Nup116, identified only in fungi, plays a central role in both protein import and mRNA export through the NPC. Nup116 is a modular protein with N-terminal 'FG' repeats containing a Gle2p-binding sequence motif and a NPC targeting domain at its C-terminus. We report the crystal structure of the NPC targeting domain of Candida glabrata Nup116, consisting of residues 882-1034 [CgNup116(882-1034)], at 1.94 {angstrom} resolution. The X-ray structure of CgNup116(882-1034) is consistent with the molecular envelope determined in solution by small-angle X-ray scattering. Structural similarities of CgNup116(882-1034) with homologous domains from Saccharomyces cerevisiae Nup116, S. cerevisiae Nup145N, and human Nup98 are discussed.

  7. Chapter 4: Genetic Identification of Fungi Involved in Wood Decay

    Science.gov (United States)

    Grant Kirker

    2014-01-01

    Wood decay is a complex process that involves contributions from molds, bacteria, decay fungi, and often insects. The first step in the accurate diagnosis of decay is identification of the causal agents, but wood decay in the strictest sense (white and brown rot) is caused by cryptic fungal species that are very difficult to identify using traditional methods. Genetic...

  8. Complex risk analysis for loss of electric power in liquid metal nuclear reactor by system dynamics (SD) method

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Tae Ho [Seoul National Univ. (Korea, Republic of). Dept. of Nuclear Engineering

    2012-07-15

    The power stabilization of the nuclear power plants (NPPs) is investigated in the aspect of the liquid metal coolant. The quantification of the risk analysis is performed by the system dynamics (SD) method which is processed by the feedback and accumulation complex algorithms. The Vensim software package is used for the simulations, which is supported by the Monte-Carlo method. There are 2 kinds of considerations as the economic and safety properties. The result shows the stability of the operations when the power can be decided. This shows the higher efficiency of the reactor. The failure frequency is 16/60 = 27%. In the event of Power Stabilized, the failure event is in the quite lower frequency rate. The commercial use of the reactor is important in the operations. (orig.)

  9. Decay data file based on the ENSDF file

    Energy Technology Data Exchange (ETDEWEB)

    Katakura, J. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    A decay data file with the JENDL (Japanese Evaluated Nuclear Data Library) format based on the ENSDF (Evaluated Nuclear Structure Data File) file was produced as a tentative one of special purpose files of JENDL. The problem using the ENSDF file as primary source data of the JENDL decay data file is presented. (author)

  10. Nuclear pyruvate kinase M2 complex serves as a transcriptional coactivator of arylhydrocarbon receptor.

    Science.gov (United States)

    Matsuda, Shun; Adachi, Jun; Ihara, Masaru; Tanuma, Nobuhiro; Shima, Hiroshi; Kakizuka, Akira; Ikura, Masae; Ikura, Tsuyoshi; Matsuda, Tomonari

    2016-01-29

    Pyruvate kinase M2 (PKM2) and pyruvate dehydrogenase complex (PDC) regulate production of acetyl-CoA, which functions as an acetyl donor in diverse enzymatic reactions, including histone acetylation. However, the mechanism by which the acetyl-CoA required for histone acetylation is ensured in a gene context-dependent manner is not clear. Here we show that PKM2, the E2 subunit of PDC and histone acetyltransferase p300 constitute a complex on chromatin with arylhydrocarbon receptor (AhR), a transcription factor associated with xenobiotic metabolism. All of these factors are recruited to the enhancer of AhR-target genes, in an AhR-dependent manner. PKM2 contributes to enhancement of transcription of cytochrome P450 1A1 (CYP1A1), an AhR-target gene, acetylation at lysine 9 of histone H3 at the CYP1A1 enhancer. Site-directed mutagenesis of PKM2 indicates that this enhancement of histone acetylation requires the pyruvate kinase activity of the enzyme. Furthermore, we reveal that PDC activity is present in nuclei. Based on these findings, we propose a local acetyl-CoA production system in which PKM2 and PDC locally supply acetyl-CoA to p300 from abundant PEP for histone acetylation at the gene enhancer, and our data suggest that PKM2 sensitizes AhR-mediated detoxification in actively proliferating cells such as cancer and fetal cells.

  11. The nuclear complex: Links between civil atom and military atom; Le complexe nucleaire. Des liens entre l'atome civil et l'atome militaire

    Energy Technology Data Exchange (ETDEWEB)

    Barrillot, B

    2005-02-15

    The fight against proliferation is topical. For lack of forgetting nuclear weapons, the international community makes the choice to limit the club of nuclear weapon owners. Nobody ignores that the way to reach bomb is the development of civil nuclear industry ( peaceful aim) these ones that want to stop the proliferation are the ardent promoters of this industry. (N.C.)

  12. Plutonium isotopes and their decay products in civil nuclear engineering; Les isotopes du plutonium et leurs descendants dans le nucleaire civil

    Energy Technology Data Exchange (ETDEWEB)

    Dautray, R

    2005-07-01

    This book is the continuation and conclusion of a previous book from the same author, entitled 'civil nuclear energy in the temporal framework of climatic changes' (Tec and Doc editions). It focusses on plutonium and on its daughter products. A synthesis of the scientific and technical data gathered so far is presented, together with the different choices offered to political authorities in the light of present-day knowledge. The authors starts from existing and firmly implemented scientific and technical data and presents some ways to solve the pending questions about the management of radioactive wastes. He shows that in our democratic system, the choice belongs to people. Beside the storage and deep disposal facilities, still necessary, some processes and problems are reviewed and explored. Of course new scientific data will be obtained, which would change the ways to discover and evaluate the ways to follow up. (J.S.)

  13. High-nuclearity Pt-Tl-Fe complexes: structural, electrochemistry, and spectroelectrochemistry studies.

    Science.gov (United States)

    Díez, Alvaro; Fernández, Julio; Lalinde, Elena; Moreno, M Teresa; Sánchez, Sergio

    2010-12-20

    A series of heteropolynuclear Pt-Tl-Fe complexes have been synthesized and structurally characterized. The final structures strongly depend on the geometry of the precursor and the Pt/Tl ratio used. Thus, the anionic heteroleptic cis-configured [cis-Pt(C(6)F(5))(2)(C≡CFc)(2)](2-) and [Pt(bzq)(C≡CFc)(2)](-) (Fc = ferrocenyl) complexes react with Tl(+) to form discrete octanuclear (PPh(3)Me)(2)[{trans,cis,cis-PtTl(C(6)F(5))(2)(C≡CFc)(2)}(2)] (1), [PtTl(bzq)(C≡CFc)(2)](2) (5; bzq = benzoquinolate), and decanuclear [trans,cis,cis-PtTl(2)(C(6)F(5))(2)(C≡CFc)(2)](2) (3) derivatives, stabilized by both Pt(II)···Tl(I) and Tl(I)···η(2)(alkynyl) bonds. By contrast, Q(2)[trans-Pt(C(6)F(5))(2)(C≡CFc)(2)] (Q = NBu(4)) reacts with Tl(+) to give the one-dimensional (1-D) anionic [(NBu(4)){trans,trans,trans-PtTl(C(6)F(5))(2)(C≡CFc)(2)}](n) (2) and neutral [trans,trans,trans-PtTl(2)(C(6)F(5))(2)(C≡CFc)(2)](n) (4) polymeric chains based on [PtFc(2)](2-) platinate fragments and Tl(+) (2) or [Tl···Tl](2+) (4) units, respectively, connected by Pt(II)···Tl(I) and secondary weak κ-η(1) (2) or η(2) (4) alkynyl···Tl(I) bonding. The formation of 1-4 is reversible, and thus treatment of neutral 3 and 4 with PPh(3)MeBr causes the precipitation of TlBr, returning toward the formation of the anionic 1 and 2' (Q = PPh(3)Me). Two slightly different pseudopolymorphs were found for 2', depending on the crystallization solvent. Finally, the reaction of the homoleptic [Pt(C≡CFc)(4)](2-) with 2 equiv of Tl(+) affords the tetradecanuclear sandwich type complex [Pt(2)Tl(4)(C≡CFc)(8)] (6). Electrochemical, spectroelectrochemical, and theoretical studies have been carried out to elucidate the effect produced by the interaction of the Tl(+) with the Pt-C≡CFc fragments. The cyclic voltammetry (CV) and differential pulse voltammetry (DPV) of 1-5 reveal that, in general, neutralization of the anionic fragments increases the stability of the fully oxidized species and

  14. SEPT12/SPAG4/LAMINB1 complexes are required for maintaining the integrity of the nuclear envelope in postmeiotic male germ cells.

    Directory of Open Access Journals (Sweden)

    Chung-Hsin Yeh

    Full Text Available Male infertility affects approximately 50% of all infertile couples. The male-related causes of intracytoplasmic sperm injection failure include the absence of sperm, immotile or immature sperm, and sperm with structural defects such as those caused by premature chromosomal condensation and DNA damage. Our previous studies based on a knockout mice model indicated that SEPT12 proteins are critical for the terminal morphological formation of sperm. SEPT12 mutations in men result in teratozospermia and oligozospermia. In addition, the spermatozoa exhibit morphological defects of the head and tail, premature chromosomal condensation, and nuclear damage. However, the molecular functions of SEPT12 during spermatogenesis remain unclear. To determine the molecular functions of SEPT12, we applied a yeast 2-hybrid system to identify SEPT12 interactors. Seven proteins that interact with SEPT12 were identified: SEPT family proteins (SEPT4 and SEPT6, nuclear or nuclear membrane proteins (protamine 2, sperm-associated antigen 4, and NDC1 transmembrane nucleoproine, and sperm-related structural proteins (pericentriolar material 1 and obscurin-like 1. Sperm-associated antigen 4 (SPAG4; also known as SUN4 belongs to the SUN family of proteins and acts as a linker protein between nucleoskeleton and cytoskeleton proteins and localizes in the nuclear membrane. We determined that SEPT12 interacts with SPAG4 in a male germ cell line through coimmunoprecipitation. During human spermiogenesis, SEPT12 is colocalized with SPAG4 near the nuclear periphery in round spermatids and in the centrosome region in elongating spermatids. Furthermore, we observed that SEPT12/SPAG4/LAMINB1 formed complexes and were coexpressed in the nuclear periphery of round spermatids. In addition, mutated SEPT12, which was screened from an infertile man, affected the integration of these nuclear envelope complexes through coimmunoprecipitation. This was the first study that suggested that SEPT

  15. Free induction decay caused by a dipole field

    Science.gov (United States)

    Ziener, C. H.; Kurz, F. T.; Kampf, T.

    2015-03-01

    We analyze the free induction decay of nuclear spins under the influence of restricted diffusion in a magnetic dipole field around cylindrical objects. In contrast to previous publications no restrictions or simplifications concerning the diffusion process are made. By directly solving the Bloch-Torrey equation, analytical expressions for the magnetization are given in terms of an eigenfunction expansion. The field strength-dependent complex nature of the eigenvalue spectrum significantly influences the shape of the free induction decay. As the dipole field is the lowest order of the multipole expansion, the obtained results are important for understanding fundamental mechanisms of spin dephasing in many other applied fields of nuclear magnetic resonance such as biophysics or material science. The analytical methods are applied to interpret the spin dephasing in the free induction decay in cardiac muscle and skeletal muscle. A simple expression for the relevant transverse relaxation time is found in terms of the underlying microscopic parameters of the muscle tissue. The analytical results are in agreement with experimental data. These findings are important for the correct interpretation of magnetic resonance images for clinical diagnosis at all magnetic field strengths and therapy of cardiovascular diseases.

  16. Thermodynamic study on complex parts of the sphere and ellipsoid of a nuclear explosive device

    Directory of Open Access Journals (Sweden)

    Zhenzhi Gou

    2016-12-01

    Full Text Available Because the heat release of plutonium material, the composite structure is heated and the stress and strain of the composite structure will increase, which will affect the thermodynamic properties of the structure. The thermodynamic analysis of complex structures, which are composed of concentric structures of plutonium, beryllium, tungsten, explosives, and steel, was carried out. The results showed that when the structure is spherical, the temperature is higher than that of the ellipsoid structure. Stress of the elliptical structure is greater than the spherical structure. This study showed that the more flat the shell is, the greater the stress concentration point occurs at the long axis, and the maximum stress occurs at the beryllium layer. These conclusions provide theoretical support for the plutonium composite component testing.

  17. Components of the CCR4-NOT complex function as nuclear hormone receptor coactivators via association with the NRC-interacting Factor NIF-1.

    Science.gov (United States)

    Garapaty, Shivani; Mahajan, Muktar A; Samuels, Herbert H

    2008-03-14

    CCR4-NOT is an evolutionarily conserved, multicomponent complex known to be involved in transcription as well as mRNA degradation. Various subunits (e.g. CNOT1 and CNOT7/CAF1) have been reported to be involved in influencing nuclear hormone receptor activities. Here, we show that CCR4/CNOT6 and RCD1/CNOT9, members of the CCR4-NOT complex, potentiate nuclear receptor activity. RCD1 interacts in vivo and in vitro with NIF-1 (NRC-interacting factor), a previously characterized nuclear receptor cotransducer that activates nuclear receptors via its interaction with NRC. As with NIF-1, RCD1 and CCR4 do not directly associate with nuclear receptors; however, they enhance ligand-dependent transcriptional activation by nuclear hormone receptors. CCR4 mediates its effect through the ligand binding domain of nuclear receptors and small interference RNA-mediated silencing of endogenous CCR4 results in a marked decrease in nuclear receptor activation. Furthermore, knockdown of CCR4 results in an attenuated stimulation of RARalpha target genes (e.g. Sox9 and HoxA1) as shown by quantitative PCR assays. The silencing of endogenous NIF-1 also resulted in a comparable decrease in the RAR-mediated induction of both Sox9 and HoxA1. Furthermore, CCR4 associates in vivo with NIF-1. In addition, the CCR4-enhanced transcriptional activation by nuclear receptors is dependent on NIF-1. The small interference RNA-mediated knockdown of NIF-1 blocks the ligand-dependent potentiating effect of CCR4. Our results suggest that CCR4 plays a role in the regulation of certain endogenous RARalpha target genes and that RCD1 and CCR4 might mediate their function through their interaction with NIF-1.

  18. Special Sm core complex functions in assembly of the U2 small nuclear ribonucleoprotein of Trypanosoma brucei.

    Science.gov (United States)

    Preusser, Christian; Palfi, Zsofia; Bindereif, Albrecht

    2009-08-01

    The processing of polycistronic pre-mRNAs in trypanosomes requires the spliceosomal small ribonucleoprotein complexes (snRNPs) U1, U2, U4/U6, U5, and SL, each of which contains a core of seven Sm proteins. Recently we reported the first evidence for a core variation in spliceosomal snRNPs; specifically, in the trypanosome U2 snRNP, two of the canonical Sm proteins, SmB and SmD3, are replaced by two U2-specific Sm proteins, Sm15K and Sm16.5K. Here we identify the U2-specific, nuclear-localized U2B'' protein from Trypanosoma brucei. U2B'' interacts with a second U2 snRNP protein, U2-40K (U2A'), which in turn contacts the U2-specific Sm16.5K/15K subcomplex. Together they form a high-affinity, U2-specific binding complex. This trypanosome-specific assembly differs from the mammalian system and provides a functional role for the Sm core variation found in the trypanosomal U2 snRNP.

  19. The emergence of the mitochondrial genome as a partial regulator of nuclear function is providing new insights into the genetic mechanisms underlying age-related complex disease.

    Science.gov (United States)

    Horan, Martin P; Cooper, David N

    2014-04-01

    Mitochondrial malfunction appears to be intimately associated with age and age-related complex disorders but the precise pathological relevance of such malfunction remains unclear. Mitochondrial, and more specifically bioenergetic, malfunction is commonly encountered in cancer, degenerative disorders and aging. The identification of a mitochondrial-nuclear retrograde signaling pathway in yeast has facilitated the study of the corresponding retrograde signaling mechanisms induced in response to mitochondrial malfunction in mammals including human. Mitochondrial-nuclear crosstalk is critical for the maintenance of cellular homeostasis, and some mitochondrial DNA mutations may perturb crosstalk signaling. However, ascertaining whether mitochondrial malfunction is a cause or a consequence of disease development will be key to determining whether or not impaired crosstalk signaling is of direct pathological and hence therapeutic relevance. Here, we review what is known about the nuclear adaptive compensatory mechanisms induced in response to mitochondrial malfunction. We discuss the role of mitochondrial DNA variants in modulating the penetrance of human inherited disease caused by mutations in the nuclear genome and explore the underlying mechanisms by which they influence the retrograde response. We conclude that mitochondrial DNA variants have the potential to induce molecular signals through the mitochondrial-nuclear crosstalk mechanism, thereby promoting nuclear compensation in response to mitochondrial malfunction. The implications for the development of genetic or pharmaceutical interventions for the treatment of mitochondrial malfunction in complex disease are also explored.

  20. A STUDY OF NEURONAL PROFILE OF INFERIOR OLIVARY NUCLEAR COMPLEX IN FOETAL AND ADULT HUMAN MEDULLA

    Directory of Open Access Journals (Sweden)

    B.Narasinga Rao

    2013-09-01

    Full Text Available Abstract: Background: ION receives proprioceptive impulses from spino-olivary tract and conveys the fibers to the cerebellum through olivo-cerebellar tract. There is paucity of data in human olivary complex, hence the present study is done. Materials And Methods: 15 adult brains and 25 fetuses of different gestations were perfused with 10% formalin and processed for histological examination. Results: Rounded cells have been seen infiltrating the entire field. at 16 weeks of gestation. Segregation of neurons into principal, medial, and dorsal accessory olivary nuclei at 20 wks gestation. Discussion: Neuron differentiation into oval, round, multipolar types has begun at 40 wks gestation. Neurons in the olivary subdivisions are grouped in separate clusters as per Ramon y Cajal,1909; Scheibel and Scheibel, 1955, Bowman and King, 1973. Multipolar neurons dominated in adult inferior olivary nucleus. Conclusion:The greater development of neurons is a consequence of finer regulation of various movements of hands and finger associated with movement of head and eyes

  1. π-π Stacking, Hydrogen Bonding and Magnetic Coupling Mechanism on a Mono-nuclear Cu^Ⅱ Complex

    Institute of Scientific and Technical Information of China (English)

    LI Hong; YU Li; ZHANG Shi-Guo; WANG Yu-Qing; SHI Jing-Min

    2012-01-01

    A new mono-nuclear CuII complex [Cu(DPP)(DP)Br](ClO4)H2O (DPP = 2-(3,5- dimethyl-1H-pyrazol-1-yl)-1,10-phenanthroline, DP = 3,5-dimethyl-1H-pyrazole) has been syn- thesized with 2-(3,5-dimethyl-1H-pyrazol-1-yl)-1,10-phenanthroline and 3,5-dimethyl-1H-pyrazole as ligands, and its crystal structure was determined by X-ray crystallography. The crystal is of monoclinic system, space group P21/c with a = 13.765(2), b = 17.044(3), c = 10.9044(16), β= 97.112(2)°, V = 2538.5(6)3, Z = 4, C22H24BrClCuN6O5, Mr = 631.37, Dc = 1.652 g/cm3, F(000) = 1276 and μ= 2.585 mm-1. In the crystal, DPP functions as a tridentate ligand and CuII ions assume a distorted square pyramidal geometry with Br atom lying on the apex, and at the same time, there is π-π stacking between adjacent complexes, which deals with two 1,10-phenanthroline plane rings. In addition to the π-π stacking, there are C-H···Br non-classic hydrogen bonds between adjacent complexes. The theoretical calculations reveal that the π-π stacking and C-H···Br non-classic hydrogen bond result in a weak anti-ferromagnetic interaction with 2J = -5.34 cm-1 and a weak ferromagnetic 2J = 5.92 cm-1, respectively. The magnetic coupling sign from the π-π stacking could be explained with McConnell I spin-polarization mechanism.

  2. TCP1 complex proteins interact with phosphorothioate oligonucleotides and can co-localize in oligonucleotide-induced nuclear bodies in mammalian cells.

    Science.gov (United States)

    Liang, Xue-hai; Shen, Wen; Sun, Hong; Prakash, Thazha P; Crooke, Stanley T

    2014-07-01

    Phosphorothioate (PS) antisense oligonucleotides (ASOs) have been successfully developed as drugs to reduce the expression of disease-causing genes. PS-ASOs can be designed to induce degradation of complementary RNAs via the RNase H pathway and much is understood about that process. However, interactions of PS-ASOs with other cellular proteins are not well characterized. Here we report that in cells transfected with PS-ASOs, the chaperonin T-complex 1 (TCP1) proteins interact with PS-ASOs and enhance antisense activity. The TCP1-β subunit co-localizes with PS-ASOs in distinct nuclear structures, termed phosphorothioate bodies or PS-bodies. Upon Ras-related nuclear protein (RAN) depletion, cytoplasmic PS-body-like structures were observed and nuclear concentrations of PS-ASOs were reduced, suggesting that TCP1-β can interact with PS-ASOs in the cytoplasm and that the nuclear import of PS-ASOs is at least partially through the RAN-mediated pathway. Upon free uptake, PS-ASOs co-localize with TCP1 proteins in cytoplasmic foci related to endosomes/lysosomes. Together, our results indicate that the TCP1 complex binds oligonucleotides with TCP1-β subunit being a nuclear PS-body component and suggest that the TCP1 complex may facilitate PS-ASO uptake and/or release from the endocytosis pathway. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  3. Neutrinos in Nuclear Physics

    CERN Document Server

    McKeown, R D

    2014-01-01

    Since the discovery of nuclear beta decay, nuclear physicists have studied the weak interaction and the nature of neutrinos. Many recent and current experiments have been focused on the elucidation of neutrino oscillations and neutrino mass. The quest for the absolute value of neutrino mass continues with higher precision studies of the tritium beta decay spectrum near the endpoint. Neutrino oscillations are studied through measurements of reactor neutrinos as a function of baseline and energy. And experiments searching for neutrinoless double beta decay seek to discover violation of lepton number and establish the Majorana nature of neutrino masses.

  4. Neutrinos in Nuclear Physics

    Energy Technology Data Exchange (ETDEWEB)

    McKeown, Bob [bmck@jlab.org

    2015-06-01

    Since the discovery of nuclear beta decay, nuclear physicists have studied the weak interaction and the nature of neutrinos. Many recent and current experiments have been focused on the elucidation of neutrino oscillations and neutrino mass. The quest for the absolute value of neutrino mass continues with higher precision studies of the tritium beta decay spectrum near the endpoint. Neutrino oscillations are studied through measurements of reactor neutrinos as a function of baseline and energy. And experiments searching for neutrinoless double beta decay seek to discover violation of lepton number and establish the Majorana nature of neutrino masses.

  5. Crystal structure of importin-{alpha} complexed with a classic nuclear localization sequence obtained by oriented peptide library screening

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, A.A.S.; Fontes, M.R.M. [UNESP, Universidade Estadual Paulista, Botucatu, SP (Brazil); Yang, S.N.Y. [University of Melbourne, Melbourne (Australia); Harris, J.M. [Queensland University of Technology, Brisbane (Australia); Jans, D.A. [Monash University, Clayton (Australia); Kobe, B. [University of Queensland, Brisbane, QU (Australia)

    2012-07-01

    Full text: Importin-{alpha} (Imp{alpha}) plays a role in the classical nuclear import pathway, binding to cargo proteins with activities in the nucleus. Different Imp{alpha} paralogs responsible for specific cargos can be found in a single organism. The cargos contain nuclear localization sequences (NLSs), which are characterized by one or two clusters of basic amino acids (monopartite and bipartite NLSs, respectively). In this work we present the crystal structure of Imp{alpha} from M. musculus (residues 70-529, lacking the auto inhibitory domain) bound to a NLS peptide (pepTM). The peptide corresponds to the optimal sequence obtained by an oriented peptide library experiment designed to probe the specificity of the major NLS binding site. The peptide library used five degenerate positions and identified the sequence KKKRR as the optimal sequence for binding to this site for mouse Imp{alpha} (70-529). The protein was obtained using an E. coli expression system and purified by affinity chromatography followed by an ion exchange chromatography. A single crystal of Imp{alpha} -pepTM complex was grown by the hanging drop method. The data were collected using the Synchrotron Radiation Source LNLS, Brazil and processed to 2.3. Molecular replacement techniques were used to determine the crystal structure. Electron density corresponding to the peptide was present in both major and minor binding sites The peptide is bound to Imp{alpha} similar as the simian virus 40 (SV40) large tumour (T)-antigen NLS. Binding assays confirmed that the peptide bound to Imp{alpha} with low nM affinities. This is the first time that structural information has been linked to an oriented peptide library screening approach for importin-{alpha}; the results will contribute to understanding of the sequence determinants of classical NLSs, and may help identify as yet unidentified classical NLSs in novel proteins. (author)

  6. Measurement of the Perturbation of the Decay Rate of ~7Be

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    ~7Be is the lightest radioactive nucleus that decays by electron capture. It is a good candidate used forlooking for perturbation of nuclear decay rates because of its simple electronic structure : 1s~22s~2.Furthermore, the decay rate of ~7Be shows its importance in some fields such as basic nuclear physics,

  7. Waste is a Terrible Thing to Mind: Perspectives on the Cleanup of the United States Nuclear Weapons Complex

    Science.gov (United States)

    Bodde, David

    1997-03-01

    For the 50 years of the Cold War, the United States nuclear arsenal was the cornerstone of our national security. These weapons were designed, manufactured, and armed with fissionable materials in an industrial complex that, at its peak, included about 16 major facilities and vast tracts of land in Nevada, Idaho, Washington, and South Carolina. Included among these are such well-known sites as the Savannah River Plant, the Hanford, Oak Ridge, and the Idaho National Engineering Laboratory. The Cold War, that "long twilight struggle" in the evocative phrase of John Kennedy, left little time and few resources for understanding and managing the environmental consequences of nuclear weapons production. At the same time, perceptions of the special nature of the atom led to a concentration of governance in the Atomic Energy Commission and the Joint Committee on Atomic Energy. Thus, external feedback for the managers of the complex was heavily filtered. But the imperatives of the Cold War have waned, and our understanding of the implications for the environment and the health and safety of workers has grown. By 1995 the Department of Energy (DoE) had spent about 23 billion in identifying and characterizing its waste, managing it, and assessing the actions needed to clean up the 120 sites in 36 states. Yet the majority of the task appeared ahead. Estimates made in 1995 suggested a total cost ranging from 200-350 billion and a time to complete of 75 years. If these were true, the cleanup of the weapons complex would become the largest civil works project in the history of humankind. Over the past year or so, the DoE program has shifted its focus from studies to actual cleanup. A strategic plan has been proposed that would accomplish most of the needed work over ten years at a cost of about $85 billion. At the same time, the Department is proposing to transfer oversight to the Nuclear Regulatory Commission, the Environmental Protection Agency, and the states. This Invited

  8. Conservation of complex nuclear localization signals utilizing classical and non-classical nuclear import pathways in LANA homologs of KSHV and RFHV.

    Directory of Open Access Journals (Sweden)

    Lidia Cherezova

    Full Text Available ORF73 latency-associated nuclear antigen (LANA of the Kaposi's sarcoma-associated herpesvirus (KSHV is targeted to the nucleus of infected cells where it binds to chromatin and mediates viral episome persistence, interacts with cellular proteins and plays a role in latency and tumorigenesis. A structurally related LANA homolog has been identified in the retroperitoneal fibromatosis herpesvirus (RFHV, the macaque homolog of KSHV. Here, we report the evolutionary and functional conservation of a novel bi-functional nuclear localization signal (NLS in KSHV and RFHV LANA. N-terminal peptides from both proteins were fused to EGFP or double EGFP fusions to examine their ability to induce nuclear transport of a heterologous protein. In addition, GST-pull down experiments were used to analyze the ability of LANA peptides to interact with members of the karyopherin family of nuclear transport receptors. Our studies revealed that both LANA proteins contain an N-terminal arginine/glycine (RG-rich domain spanning a conserved chromatin-binding motif, which binds directly to importin β1 in a RanGTP-sensitive manner and serves as an NLS in the importin β1-mediated non-classical nuclear import pathway. Embedded within this domain is a conserved lysine/arginine-(KR-rich bipartite motif that binds directly to multiple members of the importin α family of nuclear import adaptors in a RanGTP-insensitive manner and serves as an NLS in the classical importin α/β-mediated nuclear import pathway. The positioning of a classical bipartite kr-NLS embedded within a non-classical rg-NLS is a unique arrangement in these viral proteins, whose nuclear localization is critical to their functionality and to the virus life cycle. The ability to interact with multiple import receptors provides alternate pathways for nuclear localization of LANA. Since different import receptors can import cargo to distinct subnuclear compartments, a multifunctional NLS may provide LANA with an

  9. Observation of Diproron Decay From Excited States of 28S

    Institute of Scientific and Technical Information of China (English)

    LIN; Cheng-jian; XU; Xin-xing; JIA; Hui-ming; YANG; Feng; WU; Zhen-dong; ZHANG; Huan-qiao; LIU; Zu-hua; YANG; Lei; BAO; Peng-fei; SUN; Li-jie; MA; Nan-ru

    2013-01-01

    The historic discovery of radioactivity by Henri Becquerel in 1896 opened a door to nuclear science.Since then,several types of nuclear decay,like?,?,?decays,fission,one-proton(1p)radioactivity,etc.have been discovered with the development of nuclear physics.The latest,two-proton(2p)radioactivity proposed by Goldanskii more than half century ago has been already observed experimentally in the last

  10. Nuclear Hyperfine Structure in the Donor – Acceptor Complexes (CH3)3N-BF3 and (CH)33N-B(CH3)3

    Science.gov (United States)

    The donor-acceptor complexes (CH3)3N-BF3 and (CH3)3N-B(CH3)3 have been reinvestigated at high resolution by rotational spectroscopy in a supersonic jet. Nuclear hyperfine structure resulting from both nitrogen and boron has been resolved and quadrupole coupling constants have bee...

  11. Nuclear Hyperfine Structure in the Donor – Acceptor Complexes (CH3)3N-BF3 and (CH)33N-B(CH3)3

    Science.gov (United States)

    The donor-acceptor complexes (CH3)3N-BF3 and (CH3)3N-B(CH3)3 have been reinvestigated at high resolution by rotational spectroscopy in a supersonic jet. Nuclear hyperfine structure resulting from both nitrogen and boron has been resolved and quadrupole coupling constants have bee...

  12. Lorentz violation in neutron decay and allowed nuclear beta decay

    NARCIS (Netherlands)

    Noordmans, J. P.; Wilschut, H. W.; Timmermans, R. G. E.

    2013-01-01

    Background: The search for violations of Lorentz invariance is nowadays motivated by attempts to unify the standard model of particle physics with general relativity. Such theories of "quantum gravity" predict Lorentz-violating signals that could be detected in low-energy precision experiments. In

  13. Dental Caries (Tooth Decay)

    Science.gov (United States)

    ... Find Data by Topic > Dental Caries (Tooth Decay) Dental Caries (Tooth Decay) Main Content Dental caries (tooth decay) remains the most prevalent chronic ... important source of information on oral health and dental care in the United States since the early ...

  14. Semileptonic Decays

    Energy Technology Data Exchange (ETDEWEB)

    Luth, Vera G.; /SLAC

    2012-10-02

    The following is an overview of the measurements of the CKM matrix elements |V{sub cb}| and |V{sub ub}| that are based on detailed studies of semileptonic B decays by the BABAR and Belle Collaborations and major advances in QCD calculations. In addition, a new and improved measurement of the ratios R(D{sup (*)}) = {Beta}({bar B} {yields} D{sup (*)}{tau}{sup -}{bar {nu}}{sub {tau}})/{Beta}({bar B} {yields} D{sup (*)}{ell}{sup -}{bar {nu}}{sub {ell}}) is presented. Here D{sup (*)} refers to a D or a D* meson and {ell} is either e or {mu}. The results, R(D) = 0.440 {+-} 0.058 {+-} 0.042 and R(D*) = 0.332 {+-} 0.024 {+-} 0.018, exceed the Standard Model expectations by 2.0{sigma} and 2.7{sigma}, respectively. Taken together, they disagree with these expectations at the 3.4{sigma} level. The excess of events cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.

  15. Investigation of the complex structure, comparative DNA-binding and DNA cleavage of two water-soluble mono-nuclear lanthanum(III) complexes and cytotoxic activity of chitosan-coated magnetic nanoparticles as drug delivery for the complexes

    Science.gov (United States)

    Asadi, Zahra; Nasrollahi, Neda; Karbalaei-Heidari, Hamidreza; Eigner, Vaclav; Dusek, Michal; Mobaraki, Nabiallah; Pournejati, Roya

    2017-05-01

    Two water-soluble mono-nuclear macrocyclic lanthanum(III) complexes of 2,6-diformyl-4-methylphenol with 1,3-diamino-2-propanol (C1) or 1,3-propylenediamine (C2) were synthesized and characterized by UV-Vis, FT-IR, 13C and 1H NMR spectroscopy and elemental analysis. C1 complex was structurally characterized by single-crystal X-ray diffraction, which revealed that the complex was mononuclear and ten-coordinated. The coordination sites around lanthanum(III) were occupied with a five-dentate ligand, two bidentate nitrates, and one water molecule. The interaction of complexes with DNA was studied in buffered aqueous solution at pH 7.4. UV-Vis absorption spectroscopy, emission spectroscopy, circular dichroism (CD) and viscometric measurements provided clear evidence of the intercalation mechanism of binding. The obtained intrinsic binding constants (Kb) 9.3 × 103 and 1.2 × 103 M- 1 for C1 and C2, respectively confirmed that C1 is better intercalator than C2. The DNA docking studies suggested that the complexes bind with DNA in a groove binding mode with the binding affinity of C1 > C2. Moreover, agarose gel electrophoresis study of the DNA-complex for both compounds revealed that the C1 intercalation cause ethidium bromide replacement in a competitive manner which confirms the suggested mechanism of binding. Finally, the anticancer experiments for the treated cancerous cell lines with both synthesized compounds show that these hydrophilic molecules need a suitable carrier to pass through the hydrophobic nature of cell membrane efficiently.

  16. Lysine 242 within helix 10 of the pseudorabies virus nuclear egress complex pUL31 component is critical for primary envelopment of nucleocapsids.

    Science.gov (United States)

    Rönfeldt, Sebastian; Klupp, Barbara G; Franzke, Kati; Mettenleiter, Thomas C

    2017-09-06

    Newly assembled herpesvirus nucleocapsids are translocated from the nucleus to the cytosol by a vesicle-mediated process engaging the nuclear membranes. This transport is governed by the conserved nuclear egress complex (NEC), consisting of the alphaherpesviral pUL34 and pUL31 homologs. The NEC is not only required for efficient nuclear egress but also sufficient for vesicle formation from the inner nuclear membrane (INM) as well as from synthetic lipid bilayers. The recently solved crystal structures for the NECs from different herpesviruses revealed molecular details of this membrane deformation and scission machinery uncovering the interfaces involved in complex and coat formation. However, the interaction domain with the nucleocapsid remained undefined. Since the NEC assembles a curved hexagonal coat on the nucleoplasmic side of the INM consisting of tightly interwoven pUL31/pUL34 heterodimers arranged in hexamers, only the membrane-distal end of the NEC formed by pUL31 residues appears accessible for interaction with the nucleocapsid cargo. To identify the amino acids involved in capsid incorporation we mutated the corresponding regions in the alphaherpesvirus pseudorabies virus (PrV). Site-specifically mutated pUL31 were tested for localization, interaction with pUL34 and complementation of PrV-ΔUL31. Here, we identify a conserved lysine residue at amino acid position 242 in PrV pUL31 located in the alpha-helical domain H10 exposed on the membrane-distal end of the NEC as a key residue for nucleocapsid incorporation into the nascent primary particle.IMPORTANCE Vesicular transport through the nuclear envelope is a focus of research but still not well understood. Herpesviruses pioneered this mechanism for translocation of the newly assembled nucleocapsid from the nucleus into the cytosol via vesicles derived from the inner nuclear membrane which fuse in a well-tuned process with the outer nuclear membrane to release their content. The structure of the viral

  17. The search for neutrinoless double beta decay

    CERN Document Server

    Gomez-Cadenas, J J; Mezzetto, M; Monrabal, F; Sorel, M

    2011-01-01

    In the last few years the search for neutrinoless double beta decay has evolved from being almost a marginal activity in neutrino physics to one of the highest priorities for understanding neutrinos and the origin of mass. There are two main reasons for this paradigm shift: the discovery of neutrino oscillations, which clearly established the existence of massive neutrinos; and the existence of an unconfirmed, but not refuted, claim of evidence for neutrinoless double decay in 76Ge. As a consequence, a new generation of experiments, employing different detection techniques and {\\beta}{\\beta} isotopes, is being actively promoted by experimental groups across the world. In addition, nuclear theorists are making remarkable progress in the calculation of the neutrinoless double beta decay nuclear matrix elements, thus eliminating a substantial part of the theoretical uncertainties affecting the particle physics interpretation of this process. In this report, we review the main aspects of the double beta decay pro...

  18. π-π Stacking and Magnetic Coupling Mechanism on a Mono-nuclear Mn(Ⅱ) Complex

    Institute of Scientific and Technical Information of China (English)

    CHEN Hu; LIU Li-Zhen; MA Yan; DU Hua; SHI Jing-Min

    2011-01-01

    A new mono-nuclear Mn(Ⅱ) complex [Mn(MPT)2(NCS)(HOCH3)]ClO4(MPT = 2-methoxyl-1,10-phenanthroline) has been synthesized with 2-methoxyl-1,10-phenanthroline and thiocyanate anion as ligands,and its crystal structure was determined by X-ray crystallography.The crystal data:monoclinic system,space group P21/c with a = 12.8849(17),b = 15.684(2),c = 14.2703(19) ,β = 92.126(2)°,V = 2881.9(7) 3,Z = 4,C28H24ClMnN5O7S,Mr = 664.97,Dc = 1.533 g/cm3,F(000) = 1364 and μ = 0.679 mm-1.In the crystal,MPT functions as a bidentate ligand and Mn(Ⅱ) ion assumes a distorted octahedral geometry.In the crystal there are two types of π-π stacking interactions among the adjacent complexes,which involves 1,10-phenanthroline rings.The theoretical calculations reveal that the two types of π-π stacking resulted in a weak anti-ferromagnetic coupling with 2J =-14.68 cm-1 and a weak ferromagnetic coupling with 2J = 0.70 cm-1,respectively.The theoretical calculations also reveal that there are both spin polarization and spin delocalization in the two π-π stacking systems,and the magnetic coupling signs are unable to explain with McConnell I spin-polarization mechanism.

  19. Transcription profiling of Epstein-Barr virus nuclear antigen (EBNA-1 expressing cells suggests targeting of chromatin remodeling complexes.

    Directory of Open Access Journals (Sweden)

    Ramakrishna Sompallae

    Full Text Available The Epstein-Barr virus (EBV encoded nuclear antigen (EBNA-1 regulates virus replication and transcription, and participates in the remodeling of the cellular environment that accompanies EBV induced B-cell immortalization and malignant transformation. The putative cellular targets of these effects of EBNA-1 are largely unknown. To address this issue we have profiled the transcriptional changes induced by short- and long-term expression of EBNA-1 in the EBV negative B-cell lymphoma BJAB. Three hundred and nineteen cellular genes were regulated in a conditional transfectant shortly after EBNA-1 induction while a ten fold higher number of genes was regulated upon continuous EBNA-1 expression. Promoter analysis of the differentially regulated genes demonstrated a significant enrichment of putative EBNA-1 binding sites suggesting that EBNA-1 may directly influence the transcription of a subset of genes. Gene ontology analysis of forty seven genes that were consistently regulated independently on the time of EBNA-1 expression revealed an unexpected enrichment of genes involved in the maintenance of chromatin architecture. The interaction network of the affected gene products suggests that EBNA-1 may promote a broad rearrangement of the cellular transcription landscape by altering the expression of key components of chromatin remodeling complexes.

  20. Can we talk? Communications management for the Waste Isolation Pilot Plant, a complex nuclear waste management project

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, S.A.; Pullen, G.M.; Brewer, D.R.

    1995-07-01

    Sandia Nuclear Waste Management Program is pursuing for DOE an option for permanently disposing radioactive waste in deep geologic repositories. Included in the Program are the Waste Isolation Pilot Plant (WIPP) Project for US defense program mixed waste the Yucca Mountain Project (YMP) for spent power reactor fuel and vitrified high-level waste, projects for other waste types, and development efforts in environmental decision support technologies. WIPP and YMP are in the public arena, of a controversial nature, and provide significant management challenges. Both projects have large project teams, multiple organization participants, large budgets, long durations, are very complex, have a high degree of programmatic risk, and operate in an extremely regulated environment requiring legal defensibility. For environmental projects like these to succeed, SNL`s Program is utilizing nearly all areas in PMI`s Project Management Body of Knowledge (PMBOK) to manage along multiple project dimensions such as the physical sciences (e.g., geophysics and geochemistry; performance assessment; decision analysis) management sciences (controlling the triple constraint of performance, cost and schedule), and social sciences (belief systems; public participation; institutional politics). This discussion focuses primarily on communication challenges active on WIPP. How is the WIPP team meeting the challenges of managing communications?`` and ``How are you approaching similar challenges?`` will be questions for a dialog with the audience.

  1. Spatiotemporal dynamics of the nuclear pore complex transport barrier resolved by high-speed atomic force microscopy

    Science.gov (United States)

    Sakiyama, Yusuke; Mazur, Adam; Kapinos, Larisa E.; Lim, Roderick Y. H.

    2016-08-01

    Nuclear pore complexes (NPCs) are biological nanomachines that mediate the bidirectional traffic of macromolecules between the cytoplasm and nucleus in eukaryotic cells. This process involves numerous intrinsically disordered, barrier-forming proteins known as phenylalanine-glycine nucleoporins (FG Nups) that are tethered inside each pore. The selective barrier mechanism has so far remained unresolved because the FG Nups have eluded direct structural analysis within NPCs. Here, high-speed atomic force microscopy is used to visualize the nanoscopic spatiotemporal dynamics of FG Nups inside Xenopus laevis oocyte NPCs at timescales of ∼100 ms. Our results show that the cytoplasmic orifice is circumscribed by highly flexible, dynamically fluctuating FG Nups that rapidly elongate and retract, consistent with the diffusive motion of tethered polypeptide chains. On this basis, intermingling FG Nups exhibit transient entanglements in the central channel, but do not cohere into a tightly crosslinked meshwork. Therefore, the basic functional form of the NPC barrier is comprised of highly dynamic FG Nups that manifest as a central plug or transporter when averaged in space and time.

  2. Structure of the C-terminal domain of Saccharomyces cerevisiae Nup133, a component of the nuclear pore complex

    Energy Technology Data Exchange (ETDEWEB)

    Sampathkumar, Parthasarathy; Gheyi, Tarun; Miller, Stacy A.; Bain, Kevin T.; Dickey, Mark; Bonanno, Jeffrey B.; Kim, Seung Joong; Phillips, Jeremy; Pieper, Ursula; Fernandez-Martinez, Javier; Franke, Josef D.; Martel, Anne; Tsuruta, Hiro; Atwell, Shane; Thompson, Devon A.; Emtage, J. Spencer; Wasserman, Stephen R.; Rout, Michael P.; Sali, Andrej; Sauder, J. Michael; Burley, Stephen K. (Einstein); (SLAC); (Rockefeller); (UCSF); (Lilly)

    2012-10-23

    Nuclear pore complexes (NPCs), responsible for the nucleo-cytoplasmic exchange of proteins and nucleic acids, are dynamic macromolecular assemblies forming an eight-fold symmetric co-axial ring structure. Yeast (Saccharomyces cerevisiae) NPCs are made up of at least 456 polypeptide chains of {approx}30 distinct sequences. Many of these components (nucleoporins, Nups) share similar structural motifs and form stable subcomplexes. We have determined a high-resolution crystal structure of the C-terminal domain of yeast Nup133 (ScNup133), a component of the heptameric Nup84 subcomplex. Expression tests yielded ScNup133(944-1157) that produced crystals diffracting to 1.9{angstrom} resolution. ScNup133(944-1157) adopts essentially an all {alpha}-helical fold, with a short two stranded {beta}-sheet at the C-terminus. The 11 {alpha}-helices of ScNup133(944-1157) form a compact fold. In contrast, the previously determined structure of human Nup133(934-1156) bound to a fragment of human Nup107 has its constituent {alpha}-helices are arranged in two globular blocks. These differences may reflect structural divergence among homologous nucleoporins.

  3. Novel homo- and hetero-nuclear copper(II) complexes of tetradentate Schiff bases: Synthesis, characterization, solvent-extraction and catalase-like activity studies

    Energy Technology Data Exchange (ETDEWEB)

    Dede, Buelent [Sueleyman Demirel University, Department of Chemistry, Isparta, 32260 (Turkey)], E-mail: dbulent@fef.sdu.edu.tr; Karipcin, Fatma; Cengiz, Mustafa [Sueleyman Demirel University, Department of Chemistry, Isparta, 32260 (Turkey)

    2009-04-30

    Twelve homo- and hetero-nuclear copper(II) complexes of tetradentate Schiff base ligands containing N{sub 4} donor sets have been prepared by employing several steps. The characterization and nature of bonding of the complexes have been deduced from elemental analysis, FT-IR, molar conductivity, magnetic moment measurements and thermal analysis. The three Schiff base ligands were further identified using {sup 1}H and {sup 13}C NMR spectra. All copper(II) complexes are 1:2 electrolytes as shown by their molar conductivities ({lambda}{sub M}) in DMF and paramagnetic. The subnormal magnetic moment values of the di- and tri-nuclear complexes explained by a very strong anti-ferromagnetic interaction. The extraction ability of the ligands has been examined by the liquid-liquid extraction of selected transition metal (Mn{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Cu{sup 2+}, Zn{sup 2+}, Pb{sup 2+}, Cd{sup 2+}, Hg{sup 2+}) cations. The ligands show strong binding ability toward copper(II) ion. Furthermore the homo- and hetero-nuclear copper(II) complexes were each tested for their ability to catalyse the disproportionation of hydrogen peroxide in the presence of the added base imidazole.

  4. The effectiveness of power-generating complexes constructed on the basis of nuclear power plants combined with additional sources of energy determined taking risk factors into account

    Science.gov (United States)

    Aminov, R. Z.; Khrustalev, V. A.; Portyankin, A. V.

    2015-02-01

    The effectiveness of combining nuclear power plants equipped with water-cooled water-moderated power-generating reactors (VVER) with other sources of energy within unified power-generating complexes is analyzed. The use of such power-generating complexes makes it possible to achieve the necessary load pickup capability and flexibility in performing the mandatory selective primary and emergency control of load, as well as participation in passing the night minimums of electric load curves while retaining high values of the capacity utilization factor of the entire power-generating complex at higher levels of the steam-turbine part efficiency. Versions involving combined use of nuclear power plants with hydrogen toppings and gas turbine units for generating electricity are considered. In view of the fact that hydrogen is an unsafe energy carrier, the use of which introduces additional elements of risk, a procedure for evaluating these risks under different conditions of implementing the fuel-and-hydrogen cycle at nuclear power plants is proposed. Risk accounting technique with the use of statistical data is considered, including the characteristics of hydrogen and gas pipelines, and the process pipelines equipment tightness loss occurrence rate. The expected intensities of fires and explosions at nuclear power plants fitted with hydrogen toppings and gas turbine units are calculated. In estimating the damage inflicted by events (fires and explosions) occurred in nuclear power plant turbine buildings, the US statistical data were used. Conservative scenarios of fires and explosions of hydrogen-air mixtures in nuclear power plant turbine buildings are presented. Results from calculations of the introduced annual risk to the attained net annual profit ratio in commensurable versions are given. This ratio can be used in selecting projects characterized by the most technically attainable and socially acceptable safety.

  5. Spectroscopic, thermal characterization and cytotoxic activity of bi-, tri- and tetra-nuclear Pd(II) and Pt(II) complexes with diSchiff base ligands

    Science.gov (United States)

    Hegazy, Wael Hussein

    2014-10-01

    In this paper; new di-, tri-, and tetra-nuclear Pd(II) and Pt(II) complexes of N,N‧-bis(3,4-dihydroxybenzylidene)ethan-1,2-diamine (EDH4), N,N‧-bis(3,4-dihydroxy-benzylidene)-benzene-1,2-diamine (PDH4) and N,N‧-bis-(3,4-dihydroxybenzylidene)-4,5-dimethyl-1,2-diamine (MPDH4) ligands were synthesized by two different methods. The first method involve the synthesis of the three ligands from condensation reaction of 3,4-dihydroxybenzaldehyde (L‧H2) with ethylenediamine (en), o-phenylenediamine (o-PD), or 4,5-dimethyl-1,2-phenylendiamine (DMPD) in a mole ratio of 2:1 followed by the reaction of the resulting Schiff bases ligands with Pd(II) or Pt(II) ions in the presence of 2,2‧-dipyridyl (L) to form the di- and tri-nuclear metal complexes. The second method involve the condensation of the Pd complex LPd(II)L‧, (L = 2,2‧-dipyridyl, L‧ = 4-formylbenzene-1,2-bis(olate)) with en, o-PD, or DMPD in a mole ratio of 2:1, respectively, followed by reaction with PdCl2 to form di-, tri-, and tetra-nuclear palladium(II) complexes, respectively. Structures of ligands and metal complexes are characterized by physical properties, FT-IR spectra and nuclear magnetic resonance. The geometries of metal complexes are suggested according to elemental analysis, electronic absorption spectra, thermal analysis, atomic absorption, magnetic susceptibility and molar conductance. Cytotoxic activity against lung large cell carcinoma (H460), prostate carcinoma (DU145), breast adenocarcinoma (MCF-7), amelanotic melanoma (M-14), colon adenocarcinoma (HT-29), and chronic myelogenous leukemia (K562) is also reported.

  6. In-trap decay spectroscopy for {beta}{beta} decays

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, Thomas

    2011-01-18

    The presented work describes the implementation of a new technique to measure electron-capture (EC) branching ratios (BRs) of intermediate nuclei in {beta}{beta} decays. This technique has been developed at TRIUMF in Vancouver, Canada. It facilitates one of TRIUMF's Ion Traps for Atomic and Nuclear science (TITAN), the Electron Beam Ion Trap (EBIT) that is used as a spectroscopy Penning trap. Radioactive ions, produced at the radioactive isotope facility ISAC, are injected and stored in the spectroscopy Penning trap while their decays are observed. A key feature of this technique is the use of a strong magnetic field, required for trapping. It radially confines electrons from {beta} decays along the trap axis while X-rays, following an EC, are emitted isotropically. This provides spatial separation of X-ray and {beta} detection with almost no {beta}-induced background at the X-ray detector, allowing weak EC branches to be measured. Furthermore, the combination of several traps allows one to isobarically clean the sample prior to the in-trap decay spectroscopy measurement. This technique has been developed to measure ECBRs of transition nuclei in {beta}{beta} decays. Detailed knowledge of these electron capture branches is crucial for a better understanding of the underlying nuclear physics in {beta}{beta} decays. These branches are typically of the order of 10{sup -5} and therefore difficult to measure. Conventional measurements suffer from isobaric contamination and a dominating {beta} background at theX-ray detector. Additionally, X-rays are attenuated by the material where the radioactive sample is implanted. To overcome these limitations, the technique of in-trap decay spectroscopy has been developed. In this work, the EBIT was connected to the TITAN beam line and has been commissioned. Using the developed beam diagnostics, ions were injected into the Penning trap and systematic studies on injection and storage optimization were performed. Furthermore, Ge

  7. β -decay study of 94Kr

    Science.gov (United States)

    Miernik, K.; Rykaczewski, K. P.; Grzywacz, R.; Gross, C. J.; Madurga, M.; Miller, D.; Stracener, D. W.; Batchelder, J. C.; Brewer, N. T.; Cartegni, L.; Fijałkowska, A.; Karny, M.; Korgul, A.; Królas, W.; Mazzocchi, C.; Mendez, A. J., II; Padgett, S. W.; Paulauskas, S. V.; Winger, J. A.; Wolińska-Cichocka, M.; Zganjar, E. F.

    2016-08-01

    β decay of neutron-rich nuclide 94Kr was reinvestigated by means of a high resolution on-line mass separator and β -γ spectroscopy. In total 22 γ -ray transitions were assigned to the decay of 94Kr, and a new isomeric state was identified. The new information allows us to build detailed levels systematics in a chain of odd-odd rubidium isotopes and draw conclusions on nuclear structure for some of the observed states. The discussed level structure affects the evolution of β -decay half-lives for neutron-rich selenium, krypton, and strontium isotopes.

  8. Spectroscopy of element 115 decay chains.

    Science.gov (United States)

    Rudolph, D; Forsberg, U; Golubev, P; Sarmiento, L G; Yakushev, A; Andersson, L-L; Di Nitto, A; Düllmann, Ch E; Gates, J M; Gregorich, K E; Gross, C J; Heßberger, F P; Herzberg, R-D; Khuyagbaatar, J; Kratz, J V; Rykaczewski, K; Schädel, M; Åberg, S; Ackermann, D; Block, M; Brand, H; Carlsson, B G; Cox, D; Derkx, X; Eberhardt, K; Even, J; Fahlander, C; Gerl, J; Jäger, E; Kindler, B; Krier, J; Kojouharov, I; Kurz, N; Lommel, B; Mistry, A; Mokry, C; Nitsche, H; Omtvedt, J P; Papadakis, P; Ragnarsson, I; Runke, J; Schaffner, H; Schausten, B; Thörle-Pospiech, P; Torres, T; Traut, T; Trautmann, N; Türler, A; Ward, A; Ward, D E; Wiehl, N

    2013-09-13

    A high-resolution α, x-ray, and γ-ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum für Schwerionenforschung. Thirty correlated α-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z=115. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z>112. Comprehensive Monte Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

  9. Computer code for double beta decay QRPA based calculations

    Energy Technology Data Exchange (ETDEWEB)

    Barbero, C. A.; Mariano, A. [Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina and Instituto de Física La Plata, CONICET, La Plata (Argentina); Krmpotić, F. [Instituto de Física La Plata, CONICET, La Plata, Argentina and Instituto de Física Teórica, Universidade Estadual Paulista, São Paulo (Brazil); Samana, A. R.; Ferreira, V. dos Santos [Departamento de Ciências Exatas e Tecnológicas, Universidade Estadual de Santa Cruz, BA (Brazil); Bertulani, C. A. [Department of Physics, Texas A and M University-Commerce, Commerce, TX (United States)

    2014-11-11

    The computer code developed by our group some years ago for the evaluation of nuclear matrix elements, within the QRPA and PQRPA nuclear structure models, involved in neutrino-nucleus reactions, muon capture and β{sup ±} processes, is extended to include also the nuclear double beta decay.

  10. Multifrequency EPR Spectroscopy: A Toolkit for the Characterization of Mono- and Di-nuclear Metal Ion Centers in Complex Biological Systems

    Science.gov (United States)

    Hanson, Graeme R.

    Metalloenzymes are ubiquitous in nature containing complex metal ion cofactors intimately involved in the enzymes' biological function. The application of multifrequency continuous wave and orientation selective pulsed EPR in conjunction with computer simulation and density functional theory calculations has proven to be a powerful toolkit for the geometric and electronic structural characterization of these metal ion cofactors in the resting enzyme, enzyme-substrate and -product complexes, which in turn provides a detailed understanding of the enzymes' catalytic mechanism. In this chapter, a brief description of the multifrequency EPR toolkit used to structurally (geometric and electronic) characterize metal ion binding sites in complex biological systems and its application in the structural characterization of (i) molybdenum containing enzymes and model complexes, (ii) mono- and di-nuclear copper(II) cyclic peptide complexes (marine and synthetic analogues) and (iii) dinuclear metal ion centers in purple acid phosphatases will be presented.

  11. Polymerase chain reaction-single strand conformation polymorphism analyses of nuclear and chloroplast DNA provide evidence for recombination, multiple introductions and nascent speciation in the Caulerpa taxifolia complex.

    Science.gov (United States)

    Meusnier, I; Valero, M; Destombe, C; Godé, C; Desmarais, E; Bonhomme, F; Stam, W T; Olsen, J L

    2002-11-01

    Independent lines of evidence support an Australian origin for the Mediterranean populations of the tropical alga Caulerpa taxifolia. To complement previous biogeographical studies based on nuclear rDNA internal transcribed spacer (ITS), a new chloroplast marker was developed--the cp 16S rDNA intron-2. Sequence variability for both nuclear and chloroplast markers were assessed in 110 individuals using single strand conformation polymorphism. Comparison of intrapopulation genetic diversity between invasive Mediterranean and 'native' Australian populations revealed the occurrence of two divergent and widespread clades. The first clade grouped nontropical invasive populations with inshore-mainland populations from Australia, while the second clustered all offshore-island populations studied so far. Despite our finding of nine distinct nuclear and five distinct chloroplast profiles, a single nucleocytoplasmic combination was characteristic of the invasive populations and sexual reproduction was found to be very rare. C. taxifolia is clearly a complex of genetically and ecologically differentiated sibling species or subspecies.

  12. A simple decay-spectroscopy station at CRIS-ISOLDE

    Science.gov (United States)

    Lynch, K. M.; Cocolios, T. E.; Althubiti, N.; Farooq-Smith, G. J.; Gins, W.; Smith, A. J.

    2017-02-01

    A new decay-spectroscopy station (DSS2.0) has been designed by the CRIS collaboration for use at the radioactive ion beam facility, ISOLDE. With the design optimised for both charged-particle and γ-ray detection, the DDS2.0 allows high-efficiency decay spectroscopy to be performed. The DSS2.0 complements the existing decay-spectroscopy system at the CRIS experiment, and together provide the ability to perform laser-assisted nuclear decay spectroscopy on both ground state and long-lived isomeric species. This paper describes the new decay-spectroscopy station and presents the characterisation studies that have recently been performed.

  13. The shock waves in decaying supersonic turbulence

    CERN Document Server

    Smith, M D; Zuev, J M; Smith, Michael D.; Low, Mordecai-Mark Mac; Zuev, Julia M.

    2000-01-01

    We here analyse numerical simulations of supersonic, hypersonic andmagnetohydrodynamic turbulence that is free to decay. Our goals are tounderstand the dynamics of the decay and the characteristic properties of theshock waves produced. This will be useful for interpretation of observations ofboth motions in molecular clouds and sources of non-thermal radiation. We find that decaying hypersonic turbulence possesses an exponential tail offast shocks and an exponential decay in time, i.e. the number of shocks isproportional to t exp (-ktv) for shock velocity jump v and mean initialwavenumber k. In contrast to the velocity gradients, the velocity ProbabilityDistribution Function remains Gaussian with a more complex decay law. The energy is dissipated not by fast shocks but by a large number of low Machnumber shocks. The power loss peaks near a low-speed turn-over in anexponential distribution. An analytical extension of the mapping closuretechnique is able to predict the basic decay features. Our analytic descrip...

  14. Using mitochondrial and nuclear sequence data for disentangling population structure in complex pest species: a case study with Dermanyssus gallinae.

    Science.gov (United States)

    Roy, Lise; Buronfosse, Thierry

    2011-01-01

    Among global changes induced by human activities, association of breakdown of geographical barriers and impoverishered biodiversity of agroecosystems may have a strong evolutionary impact on pest species. As a consequence of trade networks' expansion, secondary contacts between incipient species, if hybrid incompatibility is not yet reached, may result in hybrid swarms, even more when empty niches are available as usual in crop fields and farms. By providing important sources of genetic novelty for organisms to adapt in changing environments, hybridization may be strongly involved in the emergence of invasive populations. Because national and international trade networks offered multiple hybridization opportunities during the previous and current centuries, population structure of many pest species is expected to be the most intricate and its inference often blurred when using fast-evolving markers. Here we show that mito-nuclear sequence datasets may be the most helpful in disentangling successive layers of admixture in the composition of pest populations. As a model we used D. gallinae s. l., a mesostigmatid mite complex of two species primarily parasitizing birds, namely D. gallinae L1 and D. gallinae s. str. The latter is a pest species, considered invading layer farms in Brazil. The structure of the pest as represented by isolates from both wild and domestic birds, from European (with a focus on France), Australian and Brazilian farms, revealed past hybridization events and very recent contact between deeply divergent lineages. The role of wild birds in the dissemination of mites appears to be null in European and Australian farms, but not in Brazilian ones. In French farms, some recent secondary contact is obviously consecutive to trade flows. Scenarios of populations' history were established, showing five different combinations of more or less dramatic bottlenecks and founder events, nearly interspecific hybridizations and recent population mixing within D

  15. Using mitochondrial and nuclear sequence data for disentangling population structure in complex pest species: a case study with Dermanyssus gallinae.

    Directory of Open Access Journals (Sweden)

    Lise Roy

    Full Text Available Among global changes induced by human activities, association of breakdown of geographical barriers and impoverishered biodiversity of agroecosystems may have a strong evolutionary impact on pest species. As a consequence of trade networks' expansion, secondary contacts between incipient species, if hybrid incompatibility is not yet reached, may result in hybrid swarms, even more when empty niches are available as usual in crop fields and farms. By providing important sources of genetic novelty for organisms to adapt in changing environments, hybridization may be strongly involved in the emergence of invasive populations. Because national and international trade networks offered multiple hybridization opportunities during the previous and current centuries, population structure of many pest species is expected to be the most intricate and its inference often blurred when using fast-evolving markers. Here we show that mito-nuclear sequence datasets may be the most helpful in disentangling successive layers of admixture in the composition of pest populations. As a model we used D. gallinae s. l., a mesostigmatid mite complex of two species primarily parasitizing birds, namely D. gallinae L1 and D. gallinae s. str. The latter is a pest species, considered invading layer farms in Brazil. The structure of the pest as represented by isolates from both wild and domestic birds, from European (with a focus on France, Australian and Brazilian farms, revealed past hybridization events and very recent contact between deeply divergent lineages. The role of wild birds in the dissemination of mites appears to be null in European and Australian farms, but not in Brazilian ones. In French farms, some recent secondary contact is obviously consecutive to trade flows. Scenarios of populations' history were established, showing five different combinations of more or less dramatic bottlenecks and founder events, nearly interspecific hybridizations and recent

  16. Heterogeneous nuclear ribonucleoprotein K upregulates the kinetochore complex component NUF2 and promotes the tumorigenicity of colon cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Sugimasa, Hironobu; Taniue, Kenzui [Laboratory of Molecular and Genetic Information, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-0032 (Japan); Kurimoto, Akiko [Laboratory of Molecular and Genetic Information, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-0032 (Japan); Oncology Research Laboratories, Daiichi Sankyo Co., Ltd, 1-2-58, Hiromachi, Shinagawa-ku, Tokyo, 140-8710 (Japan); Takeda, Yasuko; Kawasaki, Yoshihiro [Laboratory of Molecular and Genetic Information, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-0032 (Japan); Akiyama, Tetsu, E-mail: akiyama@iam.u-tokyo.ac.jp [Laboratory of Molecular and Genetic Information, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-0032 (Japan)

    2015-03-27

    Heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a multi-functional protein involved in transcription, mRNA splicing, mRNA stabilization and translation. Although hnRNP K has been suggested to play a role in the development of many cancers, its molecular function in colorectal cancer has remained elusive. Here we show that hnRNP K plays an important role in the mitotic process in HCT116 colon cancer cells. Furthermore, we demonstrate that hnRNP K directly transactivates the NUF2 gene, the product of which is a component of the NDC80 kinetochore complex and which is known to be critical for a stable spindle microtubule-kinetochore attachment. In addition, knockdown of both hnRNP K and NUF2 caused failure in metaphase chromosome alignment and drastic decrease in the growth of colon cancer cells. These results suggest that the hnRNP K-NUF2 axis is important for the mitotic process and proliferation of colon cancer cells and that this axis could be a target for the therapy of colon cancer. - Highlights: • hnRNP K is required for the tumorigenicity of colon cancer cells. • hnRNP K binds to the promoter region of NUF2 and activates its transcription. • NUF2 expression is correlated with hnRNP K expression in colorectal cancer tissue. • hnRNP K and NUF2 are required for metaphase chromosome alignment. • The hnRNP K-NUF2 axis is important for the proliferation of colon cancer cells.

  17. Somatotopic direct projections from orofacial areas of secondary somatosensory cortex to trigeminal sensory nuclear complex in rats.

    Science.gov (United States)

    Haque, T; Akhter, F; Kato, T; Sato, F; Takeda, R; Higashiyama, K; Moritani, M; Bae, Y-C; Sessle, B J; Yoshida, A

    2012-09-06

    Little is known about the projections from the orofacial areas of the secondary somatosensory cortex (S2) to the pons and medulla including the second-order somatosensory neuron pools. To address this in rats, we first examined the distribution of S2 neurons projecting to the trigeminal principal nucleus (Vp) or oral subnucleus (Vo) of the trigeminal sensory nuclear complex (TSNC) after injections of a retrograde tracer, Fluorogold (FG), into five regions in the Vp/Vo which were responsive to stimulation of trigeminal nerves innervating the orofacial tissues. A large number of FG-labeled neurons were found with a somatotopic arrangement in the dorsal areas of S2 (orofacial S2 area). This somatotopic arrangement in the orofacial S2 area was shown to closely match that of the orofacial afferent inputs by recording cortical surface potentials evoked by stimulation of the trigeminal nerves. We then examined the morphology of descending projections from these electrophysiologically defined areas of the orofacial S2 to the pons and medulla after injections of an anterograde tracer, biotinylated dextranamine (BDA), into the areas. A large number of BDA-labeled axon fibers and terminals were seen only in some of the second-order somatosensory neuron pools, most notably in the contralateral TSNC, although the labeled terminals were not seen in certain rostrocaudal levels of the contralateral TSNC including the rostrocaudal middle level of the trigeminal interpolar subnucleus. The projections to the TSNC showed somatotopic arrangements in dorsoventral, superficial-deep and rostrocaudal directions. The somatotopic arrangements in the Vp/Vo closely matched those of the electrophysiologically defined central projection sites of the orofacial trigeminal afferents in the TSNC. The present results suggest that the orofacial S2 projects selectively to certain rostrocaudal levels of the contralateral TSNC, and the projections may allow the orofacial S2 to accurately modulate

  18. DEFINING ‘PROJECT SUCCESS’ FOR A COMPLEX PROJECT – THE CASE OF A NUCLEAR ENGINEERING DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    S.I. Van Niekerk

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: The case of a nuclear engineering project was investigated to establish the relevant success criteria for the development of complex, high-technology systems. The project was first categorised according to an existing scheme, and the Delphi method was used to determine the criteria for project success that apply to this specific case. A framework of project success dimensions was extended to include criteria that are of specific importance for the project under consideration.

    While project efficiency (delivery on time and within budget obviously still needs to be controlled, the results provide empirical evidence for the notion that, for ‘super high tech’ projects, this is relatively less important. The relative importance of the dimensions of success was also evaluated and presented on a timeline stretching from project execution to 10 years after project completion. This provided empirical evidence for certain concepts in the literature.

    AFRIKAANSE OPSOMMING: Die geval van ʼn kern-ingenieursprojek is ondersoek om die relevante kriteria vir sukses vir die ontwikkeling van komplekse hoë-tegnologiesisteme te bepaal. Die projek is eerstens geklassifiseer volgens ʼn bestaande skema, en die Delphi-metode is vervolgens gebruik om die relevante kriteria vir projeksukses vir die betrokke geval te bepaal. ʼn Bestaande raamwerk van dimensies vir projeksukses is uitgebrei om kriteria wat van spesifieke belang vir die betrokke geval in te sluit.

    Terwyl tydige aflewering, binne begroting natuurlik steeds belangrik is, voorsien die resultate empiriese bewys vir die nosie in die literatuur dat hierdie aspekte van relatief minder belang is in die geval van ‘super hoë-tegnologie’-projekte. Die relatiewe belangrikheid van die dimensies van sukses is ook evalueer, en aangedui op ʼn tydlyn wat strek van projekuitvoering tot 10 jaar na die afhandeling van die projek. Dit lewer empiriese bewys vir sekere bewerings in

  19. Methodology of complexity analysis of Emergency Operating Procedures for Nuclear Power Plants; Metodologia de analisis de complejidad de Procedimientos de Operacion de Emergencia de Centrales Nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Martorell, P.; Martorell, S.; Marton, I.; Pelayo, F.; Mendizabal, R.

    2013-07-01

    The Emergency Operating Procedures (SOPs) set out the stages and contain actions to be executed by an operator to respond to an emergency situation. Methodologies are being developed to assess aspects such as complexity, completeness and vulnerability of these procedures. A methodology is presented in this paper to develop a network topology POE and analysis focused on the same complexity as a fundamental attribute.

  20. Rare Kaon Decays, KEK experiment E391 and E14 at the Japan Physics and Accelerator Research Complex (J-PARC)

    Energy Technology Data Exchange (ETDEWEB)

    Wah, Yau Wai [University of Chicago

    2012-12-06

    The goal of the J-PARC neutral kaon experiment (E14/KOTO) is to discover and measure the rate of the kaon rare decay to pi-zero and two neutrinos. This flavor changing neutral current decay proceeds through second-order weak interactions. Other, as yet undiscovered particles, which can mediate the decay could provide an enhancement (or depletion) to the branching ratio which in the Standard Model is accurately predicted within a few percent to be 2.8x10-11. The experiment is designed to observe more than 100 events at the Standard Model branching. It is a follow-up of the KEK E391a experiment and has stage-2 approval by J-PARC PAC in 2007. E14/KOTO has collaborators from Japan (Kyoto, Osaka, Yamagata, Saga), US (Arizona State, Chicago, Michigan Ann Arbor), Taiwan (National Taiwan), Korea, and Russia (Dubna). The experiment exploits the 300kW 30-50 GeV proton delivery of the J-PARC accelerator with a hermetic high acceptance detector with a fine grained Cesium Iodide (CsI) crystal calorimeter, and state of the art electronic front end and data acquisition system. With the recovery of the tsunami disaster on March 11th 2011, E14 is scheduled to start collecting data in December 2012. During the detector construction phase, Chicago focuses on the front end electronics readout of the entire detector system, particularly the CsI calorimeter. The CsI crystals together with its photomultipliers were previously used at the Fermilab KTeV experiment (E832/E799), and were loaned to E14 via this Chicago DOE support. The new readout electronics includes an innovative 10-pole pulse-shaping technique coupled with high speed digitization (14-bit 125MHz and 12-bit 500MHz). This new instrument enables us to measure both energy and timing, particularly with timing resolution better than 100 psec. Besides the cost saving by elimination of the standard time to digital converters, it is now possible to measure the momenta of the final state photons for additional background suppression

  1. DNA-histone complexes as ligands amplify cell penetration and nuclear targeting of anti-DNA antibodies via energy-independent mechanisms.

    Science.gov (United States)

    Zannikou, Markella; Bellou, Sofia; Eliades, Petros; Hatzioannou, Aikaterini; Mantzaris, Michael D; Carayanniotis, George; Avrameas, Stratis; Lymberi, Peggy

    2016-01-01

    We have generated three monoclonal cell-penetrating antibodies (CPAbs) from a non-immunized lupus-prone (NZB × NZW)F1 mouse that exhibited high anti-DNA serum titres. These CPAbs are polyreactive because they bind to DNA and other cellular components, and localize mainly in the nucleus of HeLa cells, albeit with a distinct nuclear labelling profile. Herein, we have examined whether DNA-histone complexes (DHC) binding to CPAbs, before cell entry, could modify the cell penetration of CPAbs or their nuclear staining properties. By applying confocal microscopy and image analysis, we found that extracellular binding of purified CPAbs to DHC significantly enhanced their subsequent cell-entry, both in terms of percentages of positively labelled cells and fluorescence intensity (internalized CPAb amount), whereas there was a variable effect on their nuclear staining profile. Internalization of CPAbs, either alone or bound to DHC, remained unaltered after the addition of endocytosis-specific inhibitors at 37° or assay performance at 4°, suggesting the involvement of energy-independent mechanisms in the internalization process. These findings assign to CPAbs a more complex pathogenetic role in systemic lupus erythematosus where both CPAbs and nuclear components are abundant.

  2. Recruitment of Cdc28 by Whi3 restricts nuclear accumulation of the G1 cyclin-Cdk complex to late G1.

    Science.gov (United States)

    Wang, Hongyin; Garí, Eloi; Vergés, Emili; Gallego, Carme; Aldea, Martí

    2004-01-14

    The G1 cyclin Cln3 is a key activator of cell-cycle entry in budding yeast. Here we show that Whi3, a negative G1 regulator of Cln3, interacts in vivo with the cyclin-dependent kinase Cdc28 and regulates its localization in the cell. Efficient interaction with Cdc28 depends on an N-terminal domain of Whi3 that is also required for cytoplasmic localization of Cdc28, and for proper regulation of G1 length and filamentous growth. On the other hand, nuclear accumulation of Cdc28 requires the nuclear localization signal of Cln3, which is also found in Whi3 complexes. Both Cln3 and Cdc28 are mainly cytoplasmic during early G1, and become nuclear in late G1. However, Whi3-deficient cells show a distinct nuclear accumulation of Cln3 and Cdc28 already in early G1. We propose that Whi3 constitutes a cytoplasmic retention device for Cln3-Cdc28 complexes, thus defining a key G1 event in yeast cells.

  3. p54nrb/NonO and PSF promote U snRNA nuclear export by accelerating its export complex assembly.

    Science.gov (United States)

    Izumi, Hiroto; McCloskey, Asako; Shinmyozu, Kaori; Ohno, Mutsuhito

    2014-04-01

    The assembly of spliceosomal U snRNPs in metazoans requires nuclear export of U snRNA precursors. Four factors, nuclear cap-binding complex (CBC), phosphorylated adaptor for RNA export (PHAX), the export receptor CRM1 and RanGTP, gather at the m(7)G-cap-proximal region and form the U snRNA export complex. Here we show that the multifunctional RNA-binding proteins p54nrb/NonO and PSF are U snRNA export stimulatory factors. These proteins, likely as a heterodimer, accelerate the recruitment of PHAX, and subsequently CRM1 and Ran onto the RNA substrates in vitro, which mediates efficient U snRNA export in vivo. Our results reveal a new layer of regulation for U snRNA export and, hence, spliceosomal U snRNP biogenesis.

  4. Structural determination of importin alpha in complex with beak and feather disease virus capsid nuclear localization signal

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Edward I. [Charles Sturt University, School of Animal and Veterinary Sciences, Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); EH Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); Dombrovski, Andrew K. [Charles Sturt University, School of Biomedical Sciences, Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); Swarbrick, Crystall M.D. [Charles Sturt University, School of Biomedical Sciences, Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); EH Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); Raidal, Shane R. [Charles Sturt University, School of Animal and Veterinary Sciences, Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); EH Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); Forwood, Jade K., E-mail: jforwood@csu.edu.au [Charles Sturt University, School of Biomedical Sciences, Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); EH Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Boorooma St., Wagga Wagga, New South Wales 2678 (Australia)

    2013-09-06

    Highlights: •Circovirus capsid proteins contain large nuclear localization signals (NLS). •A method of nuclear import has not been elucidated. •Beak and feather disease virus (BFDV) capsid NLS was crystallized with importin α. •The structure showed BFDV NLS binding to the major site of importin α. •Result shows implications for mechanism of nuclear transport for all circoviruses. -- Abstract: Circoviruses represent a rapidly increasing genus of viruses that infect a variety of vertebrates. Replication requires shuttling viral molecules into the host cell nucleus, a process facilitated by capsid-associated protein (Cap). Whilst a nuclear localization signal (NLS) has been shown to mediate nuclear translocation, the mode of nuclear transport remains to be elucidated. To better understand this process, beak and feather disease virus (BFDV) Cap NLS was crystallized with nuclear import receptor importin-α (Impα). Diffraction yielded structural data to 2.9 Å resolution, and the binding site on both Impα and BFDV Cap NLS were well resolved. The binding mechanism for the major site is likely conserved across circoviruses as supported by the similarity of NLSs in circovirus Caps. This finding illuminates a crucial step for infection of host cells by this viral family, and provides a platform for rational drug design against the binding interface.

  5. Complexity

    CERN Document Server

    Gershenson, Carlos

    2011-01-01

    The term complexity derives etymologically from the Latin plexus, which means interwoven. Intuitively, this implies that something complex is composed by elements that are difficult to separate. This difficulty arises from the relevant interactions that take place between components. This lack of separability is at odds with the classical scientific method - which has been used since the times of Galileo, Newton, Descartes, and Laplace - and has also influenced philosophy and engineering. In recent decades, the scientific study of complexity and complex systems has proposed a paradigm shift in science and philosophy, proposing novel methods that take into account relevant interactions.

  6. Mono-nuclear copper complexes mimicking the intermediates for the binuclear copper center of the subunit II of cytochrome oxidase: a peptide based approach.

    Science.gov (United States)

    Dutta Gupta, Dwaipayan; Usharani, Dandamudi; Mazumdar, Shyamalava

    2016-11-28

    Three stable copper complexes of peptides derived from the copper ion binding loop of the subunit II of cytochrome c oxidase have been prepared and characterized by various spectroscopic techniques. These stable copper complexes of peptides were found to exhibit cysteine, histidine and/or methionine ligation, which has predominant σ-contribution in the Cys-Cu charge transfer. The copper(ii) peptide complexes showed type-2 EPR spectra, which is uncommon in copper-cysteinate complexes. UV-visible spectra, Raman and EPR results support a tetragonal structure of the coordination geometry around the copper ion. The copper complex of the 9-amino acid peptide suggested the formation of a 'red' copper center while the copper complexes of the 12- and 11-amino acid peptides showed the formation of a 'green' copper center. The results provide insights on the first stable models of the copper complexes formed in the peptide scaffold that mimic the mono-nuclear copper bound protein intermediates proposed during the formation of the binuclear Cu2S2 core of the enzyme. These three copper complexes of peptides derived from the metal ion binding loop of the CuA center of the subunit II of cytochrome c oxidase showed novel spectroscopic properties which have not so far been reported in any stable small complex.

  7. The Nuclear Industry

    Science.gov (United States)

    Congedo, Tom; Lahoda, Edward; Matzie, Regis; Task, Keith

    The objective of the nuclear industry is to pro-duce energy in the forms of heat from either fission reactions or radioactive decay and radiation from radioactive decay or by accelerator methods. For fission heat applications, the nuclear fuel has a very high specific energy content that currently has two principal uses, for military explosives and for electricity generation. As higher temperature reactors become more widely available, the high temperature heat (>900°C) will also be useful for making chemicals such as hydrogen. For radiation applications, the emissions from radioactive decay of unstable nuclides are employed in research, medicine, and industry for diagnostic purposes and for chemical reaction initiation. Radioactive decay heat is also employed to generate electricity from thermoelectric generators for low-power applications in space or remote terrestrial locations.

  8. Creating an educational consortium to support the recruitment and retention of expertise for the nuclear weapons complex

    Energy Technology Data Exchange (ETDEWEB)

    Harmon, Frank [Idaho State Univ., Pocatello, ID (United States); Wells, Douglas P. [Idaho State Univ., Pocatello, ID (United States); Hunt, Alan [Idaho State Univ., Pocatello, ID (United States); Beller, Denis [Idaho State Univ., Pocatello, ID (United States)

    2006-12-13

    From FY 02-05 IAC has been a part of the DOE Advanced Fuel Cycle Initiative and its predecessor organization Advanced Accelerator Applications. In the IAC program effort has been divided into three parts; Student Research, Accelerator Driven Nuclear Research and Materials Science. Within the three parts specific research and development activities have been undertaken in Student Research, which supported undergraduate and graduate students, post-docs, engineering staff, program administration, project infrastructure, visiting and summer faculty appointments, visiting scientists, and support of students and faculty at the University of Michigan, Texas A&M University, University of Texas and UNLV; Accelerator Driven Nuclear Research included the use of electron accelerators to study driven sub-critical nuclear systems (ADS) and to provide practical methods of monitoring and assaying nuclear materials for accountancy in non proliferation applications (Materials Accountability and Control, MA&C); and Materials Science research at IAC supported all AFC national technical areas.

  9. The green, the nuclear and the public opinion: complex and ambiguous relations; Les verts, le nucleaire et l'opinion publique: des relations complexes et ambigues

    Energy Technology Data Exchange (ETDEWEB)

    Bazile, F. [CEA Saclay, 91 - Gif sur Yvette (France)

    2007-07-15

    Four points are the subject of controversy between the Green and the nuclear energy. the nuclear wastes, the Chernobylsk cloud that stopped at the border, the independent expertise and the caution principle. First, the solution for the high level and long lived radioactive wastes exists and is recognized by the international scientific community, beyond, the research pursues in order to reduce the ultimate wastes still further. About the second point the French Authorities have not said that the Chernobylsk cloud stopped at the border, but the difference of position between French and German information bear on the sanitary impact of this fallout. Concerning the third claim, it underestimates the dialectic character of the scientific results construction but it represent an opposite power in the French opinion. Then, the caution principle does not ask to stop an activity whom risk is not completely measured but we take any measure to anticipate and reduce this risk. Beyond these points it is known that nuclear energy does not produce greenhouse gases and this only characteristic should allow to inflect the public preference towards nuclear energy. (N.C.)

  10. Transcriptional regulation of the nuclear gene encoding the alpha-subunit of the mammalian mitochondrial F1F0 ATP synthase complex: role for the orphan nuclear receptor, COUP-TFII/ARP-1.

    Science.gov (United States)

    Jordan, Elzora M; Worley, Teri; Breen, Gail A M

    2003-03-11

    Our laboratory has been studying the transcriptional regulation of the nuclear gene (ATPA) that encodes the alpha-subunit of the mammalian mitochondrial F1F0 ATP synthase complex. We have previously determined that the regulatory factor, upstream stimulatory factor 2 (USF2), can stimulate transcription of the ATPA gene through the cis-acting regulatory element 1 in the upstream promoter of this gene. In this study, we used the yeast one-hybrid screening method to identify another factor, COUP-TFII/ARP-1, which also binds to the ATPA cis-acting regulatory element 1. Binding of the orphan nuclear receptor, COUP-TFII/ARP-1, to the ATPA regulatory element 1 was confirmed using electrophoretic mobility shift experiments, and COUP-TFII/ARP-1-containing complexes were detected in HeLa cell nuclear extracts. A mutational analysis indicated that the binding site for COUP-TFII/ARP-1 in the ATPA regulatory element 1 is an imperfect direct repeat of a nuclear receptor response element (A/GGGTCA) with a spacer of three nucleotides. Functional assays in HeLa cells showed that COUP-TFII/ARP-1 represses the ATPA promoter activity in a dose- and sequence-dependent manner. Furthermore, cotransfection assays demonstrated that COUP-TFII/ARP-1 inhibits the USF2-mediated activation of the wild-type ATPA gene promoter but not a mutant promoter that is defective in COUP-TFII/ARP-1-binding. Overexpression of USF2 reversed the COUP-TFII/ARP-1-mediated repression of the ATPA promoter. Mobility shift assays revealed that COUP-TFII/ARP-1 and USF2 compete for binding to the ATPA regulatory element 1. Thus, the ATPA gene is regulated by a multifunctional binding site through which the transcription factors, COUP-TFII/ARP-1 and USF2, bind and exert their antagonistic effects.

  11. Testing Lorentz invariance in weak decays

    Energy Technology Data Exchange (ETDEWEB)

    Sytema, Auke; Dijck, Elwin; Hoekstra, Steven; Jungmann, Klaus; Mueller, Stefan; Noordmans, Jacob; Onderwater, Gerco; Pijpker, Coen; Timmermans, Rob; Vos, Keri; Willmann, Lorenz; Wilschut, Hans [Van Swinderen Institute, University of Groningen (Netherlands)

    2015-07-01

    Lorentz invariance is the invariance of physical laws under orientations and boosts. It is a key assumption in Special Relativity and the Standard Model of Particle Physics. Several theories unifying General Relativity and Quantum Mechanics allow breaking of Lorentz invariance. At the Van Swinderen Institute in Groningen a theoretical and experimental research program was started to study Lorentz invariance violation (LIV) in weak interactions. The theoretical work allowed a systematic approach to LIV in weak decays. Limits could be set on parameters that quantify LIV. A novel beta decay experiment was designed which tests rotational invariance with respect to the orientation of nuclear spin. In particular, using the isotope {sup 20}Na, the decay rate dependence on the nuclear polarization direction was measured. Searching for sidereal variations, systematic errors can be suppressed. The result of the experiment is presented.

  12. Complex

    African Journals Online (AJOL)

    CLEMENT O BEWAJI

    Schiff bases and their complex compounds have been studied for their .... establishing coordination of the N–(2 – hydroxybenzyl) - L - α - valine Schiff base ..... (1967); “Spectrophotometric Identification of Organic Compounds”, Willey, New.

  13. Cavities/Tooth Decay

    Science.gov (United States)

    Cavities/tooth decay Overview By Mayo Clinic Staff Cavities are permanently damaged areas in the hard surface of your teeth ... into tiny openings or holes. Cavities, also called tooth decay or caries, are caused by a combination of ...

  14. Cyclam Derivatives with a Bis(phosphinate) or a Phosphinato-Phosphonate Pendant Arm: Ligands for Fast and Efficient Copper(II) Complexation for Nuclear Medical Applications.

    Science.gov (United States)

    David, Tomáš; Kubíček, Vojtěch; Gutten, Ondrej; Lubal, Přemysl; Kotek, Jan; Pietzsch, Hans-Jürgen; Rulíšek, Lubomír; Hermann, Petr

    2015-12-21

    Cyclam derivatives bearing one geminal bis(phosphinic acid), -CH2PO2HCH2PO2H2 (H2L(1)), or phosphinic-phosphonic acid, -CH2PO2HCH2PO3H2 (H3L(2)), pendant arm were synthesized and studied as potential copper(II) chelators for nuclear medical applications. The ligands showed good selectivity for copper(II) over zinc(II) and nickel(II) ions (log KCuL = 25.8 and 27.7 for H2L(1) and H3L(2), respectively). Kinetic study revealed an unusual three-step complex formation mechanism. The initial equilibrium step leads to out-of-cage complexes with Cu(2+) bound by the phosphorus-containing pendant arm. These species quickly rearrange to an in-cage complex with cyclam conformation II, which isomerizes to another in-cage complex with cyclam conformation I. The first in-cage complex is quantitatively formed in seconds (pH ≈5, 25 °C, Cu:L = 1:1, cM ≈ 1 mM). At pH >12, I isomers undergo nitrogen atom inversion, leading to III isomers; the structure of the III-[Cu(HL(2))] complex in the solid state was confirmed by X-ray diffraction analysis. In an alkaline solution, interconversion of the I and III isomers is mutual, leading to the same equilibrium isomeric mixture; such behavior has been observed here for the first time for copper(II) complexes of cyclam derivatives. Quantum-chemical calculations showed small energetic differences between the isomeric complexes of H3L(2) compared with analogous data for isomeric complexes of cyclam derivatives with one or two methylphosphonic acid pendant arm(s). Acid-assisted dissociation proved the kinetic inertness of the complexes. Preliminary radiolabeling of H2L(1) and H3L(2) with (64)Cu was fast and efficient, even at room temperature, giving specific activities of around 70 GBq of (64)Cu per 1 μmol of the ligand (pH 6.2, 10 min, ca. 90 equiv of the ligand). These specific activities were much higher than those of H3nota and H4dota complexes prepared under identical conditions. The rare combination of simple ligand synthesis, very

  15. Ca2+/calmodulin-dependent kinase II contributes to inhibitor of nuclear factor-kappa B kinase complex activation in Helicobacter pylori infection.

    Science.gov (United States)

    Maubach, Gunter; Sokolova, Olga; Wolfien, Markus; Rothkötter, Hermann-Josef; Naumann, Michael

    2013-09-15

    Helicobacter pylori, a class I carcinogen, induces a proinflammatory response by activating the transcription factor nuclear factor-kappa B (NF-κB) in gastric epithelial cells. This inflammatory condition could lead to chronic gastritis, which is epidemiologically and biologically linked to the development of gastric cancer. So far, there exists no clear knowledge on how H. pylori induces the NF-κB-mediated inflammatory response. In our study, we investigated the role of Ca(2+) /calmodulin-dependent kinase II (CAMKII), calmodulin, protein kinases C (PKCs) and the CARMA3-Bcl10-MALT1 (CBM) complex in conjunction with H. pylori-induced activation of NF-κB via the inhibitor of nuclear factor-kappa B kinase (IKK) complex. We use specific inhibitors and/or RNA interference to assess the contribution of these components. Our results show that CAMKII and calmodulin contribute to IKK complex activation and thus to the induction of NF-κB in response to H. pylori infection, but not in response to TNF-α. Thus, our findings are specific for H. pylori infected cells. Neither the PKCs α, δ, θ, nor the CBM complex itself is involved in the activation of NF-κB by H. pylori. The contribution of CAMKII and calmodulin, but not PKCs/CBM to the induction of an inflammatory response by H. pylori infection augment the understanding of the molecular mechanism involved and provide potential new disease markers for the diagnosis of gastric inflammatory diseases including gastric cancer.

  16. Neutrinoless double beta decay experiments

    CERN Document Server

    Zuber, K

    2006-01-01

    The study of neutrinoless double beta decay is of outmost importance for neutrino physics. It is considered to be the gold plated channel to probe the fundamental character of neutrinos and to determine the neutrino mass. From the experimental point about nine different isotopes are explored for the search. After a general introduction follows a short discussion on nuclear matrix element calculations and supportive measurements. The current experimental status of double beta searches is presented followed by a short discussion of the ideas and proposals for large scale experiments.

  17. Introduction to nuclear physics.

    Science.gov (United States)

    Patton, J A

    1998-01-01

    Photons for counting or imaging applications in nuclear medicine result from several processes. Gamma rays are produced from excited state transitions after beta decay and electron capture. Annihilation photons result from positron decay. The de-excitation of the atom after electron capture results in the production of characteristic x rays or Auger electrons. Metastable state transitions result in gamma ray emission or internal conversion electrons. All radiopharmaceuticals used in diagnostic nuclear medicine applications are tagged with radionuclides that emit photons as a result of one of these processes.

  18. Time-resolved studies of interatomic Coulombic decay

    Energy Technology Data Exchange (ETDEWEB)

    Frühling, U. [Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Center for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg (Germany); Trinter, F. [Institut für Kernphysik, Goethe Universität, Max-von-Laue-Str.1, 60438 Frankfurt (Germany); Karimi, F. [Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Center for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg (Germany); Williams, J.B. [Institut für Kernphysik, Goethe Universität, Max-von-Laue-Str.1, 60438 Frankfurt (Germany); Jahnke, T., E-mail: jahnke@atom.uni-frankfurt.de [Institut für Kernphysik, Goethe Universität, Max-von-Laue-Str.1, 60438 Frankfurt (Germany)

    2015-10-15

    Interatomic Coulombic decay (ICD) is a decay mechanism occurring in loosely bound matter, e.g. in systems bound by van der Waals-forces or hydrogen bonds. In many such cases the decay time is similar to the time scale of nuclear motion during the decay. As the efficiency of ICD strongly depends on the internuclear distance of the atoms or molecules involved in the decay, an overall non-trivial temporal decay behavior arises. The progress of examining the time-domain aspects of interatomic Coulombic decay is summarized in this short topical review with a special emphasis on experiments that are now feasible due to the developments of free-electron lasers.

  19. Extracellular signal-regulated kinase 2 (ERK2) phosphorylation sites and docking domain on the nuclear pore complex protein Tpr cooperatively regulate ERK2-Tpr interaction.

    Science.gov (United States)

    Vomastek, Tomás; Iwanicki, Marcin P; Burack, W Richard; Tiwari, Divya; Kumar, Devanand; Parsons, J Thomas; Weber, Michael J; Nandicoori, Vinay Kumar

    2008-11-01

    Identifying direct substrates of mitogen-activated protein kinases (MAPKs) and understanding how those substrates are selected is central to understanding how these ubiquitously activated enzymes generate diverse biological responses. In previous work, we identified several new candidate substrates for the MAPK ERK2 (extracellular signal-regulated kinase 2), including the nuclear pore complex protein Tpr (translocated promoter region). In this report, we identify sites on Tpr for ERK2 phosphorylation and binding and demonstrate their functional interaction. ERK2 phosphorylation and dimerization are necessary for ERK2-Tpr binding, and this occurs through a DEF (docking site for ERK2, FXF) domain on Tpr. Surprisingly, the DEF domain and the phosphorylation sites displayed positive cooperativity to promote ERK2 binding to Tpr, in contrast to substrates where phosphorylation reduces binding. Ectopic expression or depletion of Tpr resulted in decreased movement of activated ERK2 from the cytoplasm to the nucleus, implying a role for Tpr in ERK2 translocation. Collectively, the data provide direct evidence that a component of the nuclear pore complex is a bona fide substrate of ERK2 in vivo and that activated ERK2 stably associates with this substrate after phosphorylation, where it could play a continuing role in nuclear pore function. We propose that Tpr is both a substrate and a scaffold for activated ERKs.

  20. NRV web knowledge base on low-energy nuclear physics

    Science.gov (United States)

    Karpov, V.; Denikin, A. S.; Alekseev, A. P.; Zagrebaev, V. I.; Rachkov, V. A.; Naumenko, M. A.; Saiko, V. V.

    2016-09-01

    Principles underlying the organization and operation of the NRV web knowledge base on low-energy nuclear physics (http://nrv.jinr.ru) are described. This base includes a vast body of digitized experimental data on the properties of nuclei and on cross sections for nuclear reactions that is combined with a wide set of interconnected computer programs for simulating complex nuclear dynamics, which work directly in the browser of a remote user. Also, the current situation in the realms of application of network information technologies in nuclear physics is surveyed. The potential of the NRV knowledge base is illustrated in detail by applying it to the example of an analysis of the fusion of nuclei that is followed by the decay of the excited compound nucleus formed.