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Sample records for forbidden beta transitions

  1. Nuclear beta decay induced by intense electromagnetic fields: Forbidden transition examples

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1983-01-01

    A formalism developed earlier for the effect on nuclear beta decay of an intense plane-wave electromagnetic field is applied to three examples of forbidden beta transitions. The examples represent cases where the nuclear ''fragment'' contains one, two, and three nucleons; where the nuclear fragment is defined to be that smallest sub-unit of the nucleus containing the nucleon which undergoes beta decay plus any other nucleons directly angular-momentum coupled to it in initial or final states. The single-nucleon-fragment example is 113 Cd, which has a fourth-forbidden transition. The two-nucleon-fragment example is 90 Sr, which is first-forbidden. The three-nucleon-fragment example is 87 Rb, which is third-forbidden. An algebraic closed-form transition probability is found in each case. At low external-field intensity, the transition probability is proportional to z/sup L/, where z is the field intensity parameter and L is the degree of forbiddenness. At intermediate intensities, the transition probability behaves as z/sup L/-(1/2). At higher intensities, the transition probability contains the z/sup L/-(1/2) factor, a declining exponential factor, and an alternating polynomial in z. This high-intensity transition probability possesses a maximum value, which is found for each of the examples. A general rule, z = q 2 (2L-1), where q is the number of particles in the fragment, is found for giving an upper limit on the intensity at which the maximum transition probability occurs. Field-induced beta decay half-lives for all the examples are dramatically reduced from natural half-lives when evaluated at the optimum field intensity. Relative half-life reduction is greater the higher the degree of forbiddenness

  2. Meson-Exchange Enhancement of First-Forbidden $\\beta$-Transitions in the Lead Region

    CERN Multimedia

    Delaure, B J P; Severijns, N

    2002-01-01

    Both on-line and off-line low temperature nuclear orientation is used to measure the $\\beta$-asymmetry parameter for the first-forbidden g.s. $\\rightarrow$~g.s. $\\beta$-transitions of $^{205}$Hg, $^{207,209}$Tl, $^{209}$Pb and $^{213}$Bi. From this, the ratio of the rank-zero and the rank-one strengths in these decays can be deduced, with the rank of a $\\beta$-transition being defined as the total angular momentum of the lepton system. Combining this result with the experimental ${ft}$-values yields for the first time a purely experimental determination of the rank-zero contribution in these $\\Delta$ J = 0 first-forbidden transitions. This provides an independent check of the large enhancement (of about 100% over the impulse approximation) of the rank-zero matrix element of $\\gamma_{5} $, caused by meson exchange currents (MEC), which was recently obtained from a comparison of calculated first-forbidden $\\beta$-decay rates with experimentally observed values for nuclei in the lead region (A = 205-212). Measur...

  3. Study of once and twice forbidden {beta} transitions; Contribution a l'etude de transitions {beta} une fois et deux fois interdites

    Energy Technology Data Exchange (ETDEWEB)

    Hocquenghem, J C [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1967-09-01

    The realisation of an experimental set up for directional angular correlation measurements allowed us to determine {beta} - {gamma} angular correlations. These measurements together with the determination of the {beta} shape-factor have been made for the following transitions: the first forbidden {beta}{sup -} transitions of 386 keV in the {sup 177}Lu disintegration and of 352 keV in the {sup 175}Yb disintegration. The experimental results have been compared with theoretical predictions of the Nilsson's model; the twice forbidden {beta}{sup -} transition of 473 keV in the {sup 94}Nb disintegration. The {beta} transition nuclear matrix elements have been extracted from the experimental results. Comparison have been made with the theoretical values calculated by taking for nuclear wavefunctions those obtained by diagonalization of the residual interaction and assuming that protons and neutrons outside the {sup 90}Zr core are respectively on the 1 g 9/2 and 2 d 5/2 orbits. (author) [French] La realisation d'un ensemble de mesures de correlations angulaires directionnelles nous a permis la mesure de correlations {beta} - {gamma} en fonction de l'energie. En completant celles-ci par la mesure du facteur de forme du spectre {beta}, nous avons pu etudier ainsi: d'une part, les transitions {beta}{sup -} une fois interdites de 386 keV de la desintegration de {sup 177}Lu et de 352 keV de la desintegration de {sup 175}Yb, Les resultats experimentaux ont ete compares aux valeurs calculees dans le modele de Nilsson; d'autre part, la transition {beta}- deux fois interdite de 473 keV de la desintegration de {sup 94}Nb. Les elements de matrice nucleaire de la transition {beta}, extraits des resultats experimentaux, ont ete compares aux valeurs theoriques calculees. Les fonctions d'ondes nucleaires utilisees ont ete obtenues par diagonalisation de l'interaction residuelle en supposant que les protons et les neutrons, en dehors du coeur forme par le {sup 90}Zr, sont respectivement

  4. Meson-exchange enhancement of the first forbidden $0^{+} \\leftrightarrow 0^{-} \\beta$-transitions

    CERN Multimedia

    2002-01-01

    In the frame of the standard model of the weak interaction, it has been suggested by Kubodera, Delorme and Rho, that pion exchange should have a large effect on the rank-zero time-like component of the axial current A$_{0}$. The best case for the study of A$ _{0}$ is $0^{-} \\leftrightarrow 0^{+} \\beta$-decay since in this process only rank zero matrix elements of the time-like and space-like components of the axial current contribute to the transition rate. $0^{-} \\leftrightarrow 0^{+}$ decays have been studied in the vicinity of doubly closed-shell nuclei such as $^{16}$O, $^{96}$Zr, and $^{208}$Pb where s$_{1/2} \\leftrightarrow$ p$_{1/2}$ matrix elements were involved. In these cases, the meson-exchange correction to the one-body axial-charge density is significant. ISOLDE offers the possibility to perform sensitive measurements of the $0^{-} \\leftrightarrow 0^{+}$ pseudoscalar decay in nuclei where the p$_{3/2} \\rightarrow$ d$_{3/2}$ matrix elements are involved. We therefore propose a search of the $^{38}...

  5. K-forbidden transition probabilities

    International Nuclear Information System (INIS)

    Saitoh, T.R.; Sletten, G.; Bark, R.A.; Hagemann, G.B.; Herskind, B.; Saitoh-Hashimoto, N.; Tsukuba Univ., Ibaraki

    2000-01-01

    Reduced hindrance factors of K-forbidden transitions are compiled for nuclei with A∝180 where γ-vibrational states are observed. Correlations between these reduced hindrance factors and Coriolis forces, statistical level mixing and γ-softness have been studied. It is demonstrated that the K-forbidden transition probabilities are related to γ-softness. The decay of the high-K bandheads has been studied by means of the two-state mixing, which would be induced by the γ-softness, with the use of a number of K-forbidden transitions compiled in the present work, where high-K bandheads are depopulated by both E2 and ΔI=1 transitions. The validity of the two-state mixing scheme has been examined by using the proposed identity of the B(M1)/B(E2) ratios of transitions depopulating high-K bandheads and levels of low-K bands. A break down of the identity might indicate that other levels would mediate transitions between high- and low-K states. (orig.)

  6. 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)

  7. Boson forbidden transitions and their manifestation in spherical nuclei

    International Nuclear Information System (INIS)

    Stoyanov, Ch.

    2002-01-01

    For the correct description of the 'boson forbidden' transitions it is necessary to go beyond the quasi-boson approximation and to take into account the fermion structure of the phonons. Once it done it is quantitative description of the transitions is possible within the simplest model based on the separable residual interactions. Calculations of the forbidden E1-transitions in 120 Sn, 144 Sm and 144 Nd are presented. Analysis of some low-energy M1-transitions is made using IBM-2. The discussed examples reveal the complex properties of the low-lying excited states

  8. Allowed and forbidden transition parameters for Fe XV

    International Nuclear Information System (INIS)

    Nahar, Sultana N.

    2009-01-01

    A comprehensive set of fine structure energy levels, oscillator strengths (f), line strengths (S), and radiative decay rates (A) for bound-bound transitions in Fe XV is presented. The allowed electric dipole (E1) transitions were obtained from the relativistic Breit-Pauli R-matrix method which is based on the close coupling approximation. A total of 507 fine structure energy levels with n ≤ 10, l ≤ 9, and 0 ≤ J ≤ 10 are found. They agree within 1% with the available observed energies. These energy levels yield a total of 27,812 E1, same-spin multiplets and intercombination transitions. The A values are in good agreement with those compiled by NIST and other existing values for most transitions. Forbidden transitions are obtained from a set of 20 configurations with orbitals ranging from 1s to 5f using the relativistic code SUPERSTRUCTURE (SS) in the Breit-Pauli approximation. From a set of 123 fine structure levels, a total of 6962 S and A values are presented for forbidden electric quadrupole (E2), electric octupole (E3), magnetic dipole (M1), and magnetic quadrupole (M2) transitions. The energies from SS calculations agree with observed energies to within 1-3%. A values for E2, M1 transitions agree very well with the available values for most transitions while those for M2 transitions show variable agreement. The large set of transition parameters presented should be applicable for both diagnostics and spectral modeling in the X-ray, ultraviolet, and optical regions of astrophysical plasmas.

  9. E1-forbidden transition rates in ions of astrophysical interest

    International Nuclear Information System (INIS)

    Träbert, E

    2014-01-01

    Transition rates in atomic systems may appear to be of little importance in steady-state plasmas that are observed at great distances from Earth. However, some of the transition rates compete with collision rates, and in these cases certain line intensity ratios are affected and can serve as remote indicators of density. In the low-density environments of stellar coronae and planetary nebulae, the transition rates of interest are mostly spin-forbidden E1 decays, higher-multipole order transitions (M1, E2, M2, M3), and hyperfine-induced transitions. On Earth, measurements of the long upper level lifetimes of these atomic systems require the use of ion traps. A fair number of test cases with lifetimes in the range from nanoseconds to many seconds have been treated successfully, and the evolution of calculations along with the experimental progress is notable. A new generation of cold ion traps is expected to extend the atomic lifetime measurements on multiply charged ions into the range of many minutes. (paper)

  10. Study of an Isospin-Forbidden $0^{+} \\rightarrow 0^{+}$ Transition in $^{38m}$K

    CERN Multimedia

    2002-01-01

    There is at present a discrepancy between the precisely determined value of $V_{ud}^{2}$ obtained from $0^{+} \\rightarrow 0^{+} $ nuclear $\\beta$-decay and the less precisely determined value inferred from neutron decay. One possible explanation for this discrepancy involves the " Coulomb " corrections that must be applied to the nuclear decay rates. We propose to investigate one class of these corrections (for charge-dependent configuration-mixing) by measuring the isospin-forbidden $0^{+} \\rightarrow 0^{+}$ decay rate in $^{38m}$K. $^{38m}$K decay is particularly interesting because it is predicted to have the largest charge-dependent mixing correction of any of the transitions used in the $V_{ud}^{2}$ determination.

  11. Contribution to the study of once-forbidden {beta} transitions. Case of {sup 42}K and {sup 86}Rb; Contribution a l'etude des transitions {beta} une fois interdites. Cas de K{sup 42} et Rb{sup 86}

    Energy Technology Data Exchange (ETDEWEB)

    Andre, St [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1965-10-01

    An apparatus has been developed for studying the exact shape of the spectra of {beta} transitions which lead to an excited state of the final nucleus, using a Siegbahn-Slattis {beta} spectrometer. In particular the {beta} spectrum of the 2- {yields} 2+ transition of {sup 42}K has been measured; a considerable deviation has been found with respect to the statistical shape. The six elements of the nuclear matrices for this transition have been determined using this measurement and other results. It is shown that it cannot be explained by a pure f7/2 {yields} d3/2 transition. Furthermore the value obtained for the ratio of the matrix elements {integral}{alpha} and {integral}r is in excellent agreement with that predicted from the theory for the maintained vectorial current. (author) [French] On a realise et mis au point un appareillage permettant l'etude des formes precises des spectres {beta} des transitions aboutissant a un etat excite du noyau final sur un spectrometre {beta} Siegbahn-Slatis. On a mesure notamment le spectre {beta} de la transition 2- {yields} 2+ du K{sup 42}, mettant en evidence une deviation importante par rapport a la forme statistique. A partir de cette mesure et d'autres resultats, on a determine les six elements de matrice nucleaires de cette transition. On montre qu'elle ne peut pas etre expliquee par une transition f7/2 {yields} d3/2 pure. D'autre part, la valeur obtenue pour le rapport des elements de matrice {integral}{alpha} et {integral}r est en excellent accord avec celle qui est prevue a partir de la theorie du courant vectoriel conserve. (auteur)

  12. Identification of forbidden vibration-rotation transitions in 15NH3

    Science.gov (United States)

    Urban, Š.; D'Cunha, Romola; Narahari Rao, K.

    1984-07-01

    Forbidden Δk - l = 3 vibration-rotation transitions have been observed in the ν4 band of 15NH3. The analysis of these transitions, together with previously published data on the allowed transitions, has made it possible to determine a set of molecular parameters, including for the first time the rotational constant C as well as the centrifugal distortion constants DK and HKKK, which are necessary for the calculation of energy levels. Some weak forbidden transitions in the ν2 band have also been observed.

  13. Analysis of unique beta transitions

    DEFF Research Database (Denmark)

    Eman, B.; Krmpotic, F.; Tadic, D

    1967-01-01

    -non-conserving tensor form factor b > 0. In the former case they contradict Daniel's results [See abstr. 1966A10720] for 0- rarr 0+ transitions, whereas in the latter they are in disagreement with other known analyses of mu-meson capture, allowed and forbidden transitions. The conclusion appears to be independent...... of limited variations of nuclear matrix element ratios. A complete theoretical expression for the shape factor and details of the analysis are presented....

  14. Selection rule engineering of forbidden transitions of a hydrogen atom near a nanogap

    Science.gov (United States)

    Kim, Hyunyoung Y.; Kim, Daisik S.

    2018-01-01

    We perform an analytical study on the allowance of forbidden transitions for a hydrogen atom placed near line dipole sources, mimicking light emanating from a one-dimensional metallic nanogap. It is shown that the rapid variation of the electric field vector, inevitable in the near zone, completely breaks the selection rule of Δl=±1. While the forbidden transitions between spherically symmetric S states, such as 2S to 1S or 3S to 1S (Δl=0), are rather robust against selection rule breakage, Δl=±2 transitions such as between 3D and 1S or 3D and 2S states are very vulnerable to the spatial variation of the perturbing electric field. Transitions between 2S and 3D states are enhanced by many orders of magnitude, aided by the quadratic nature of both the perturbing Hamiltonian and D wavefunctions. The forbidden dipole moment, which approaches one Bohr radius times the electric charge in the vicinity of the gap, can be written in a simple closed form owing to the one-dimensional nature of our gap. With large enough effective volume together with the symmetric nature of the excited state wavefunctions, our work paves way towards atomic physics application of infinitely long nanogaps.

  15. Forbidden atomic transitions driven by an intensity-modulated laser trap.

    Science.gov (United States)

    Moore, Kaitlin R; Anderson, Sarah E; Raithel, Georg

    2015-01-20

    Spectroscopy is an essential tool in understanding and manipulating quantum systems, such as atoms and molecules. The model describing spectroscopy includes the multipole-field interaction, which leads to established spectroscopic selection rules, and an interaction that is quadratic in the field, which is not often employed. However, spectroscopy using the quadratic (ponderomotive) interaction promises two significant advantages over spectroscopy using the multipole-field interaction: flexible transition rules and vastly improved spatial addressability of the quantum system. Here we demonstrate ponderomotive spectroscopy by using optical-lattice-trapped Rydberg atoms, pulsating the lattice light and driving a microwave atomic transition that would otherwise be forbidden by established spectroscopic selection rules. This ability to measure frequencies of previously inaccessible transitions makes possible improved determinations of atomic characteristics and constants underlying physics. The spatial resolution of ponderomotive spectroscopy is orders of magnitude better than the transition frequency would suggest, promising single-site addressability in dense particle arrays for quantum computing applications.

  16. The β+ decay of 234Np and other isospin-forbidden 0+ -> 0+ Fermi transitions

    International Nuclear Information System (INIS)

    Yap, C.T.; Saw, E.L.

    1984-01-01

    Although experimental values of the Fermi nuclear matrix elements vary widely from about 1x10 -3 to 40x10 -3 for isospin-forbidden 0 + ->0 + β transitions, theoretical calculations using the Coulomb potential and Nilsson wave functions yielded values of Msub(F) in reasonably good agreement, except that of 234 Np. However, our calculation of Msub(F) for this decay as a function of the deformation parameter β yielded a value of Msub(F) in good agreement with experiment for values of β between 0.1 and 0.2. (orig.)

  17. Electron impact excitation of complex atoms and ions. Pt. 2: forbidden transitions in Ni+

    International Nuclear Information System (INIS)

    Watts, M.S.T.; Berrington, K.A.; Burke, P.G.

    1996-01-01

    This letter reports the first application of the new R-matrix program package RMATRX II to electron impact excitation of a near neutral open d-shell ion. In this calculation for Ni + , all states corresponding to the configuration 3d 9 , 3d 8 4s and 3d 8 4p have been included in the expansion of the total wavefunction. Thermally averaged collision strengths for forbidden transitions involving the even parity states are presented in tabular form for temperatures between 5000 K and 20 000 K. The importance of including accurate C1 expansions for both the target and the (N + 1)-electron terms is demonstrated. (Author)

  18. Reply to ''Comment on enhancement of forbidden nuclear beta decay by high-intensity radio-frequency fields''

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1984-01-01

    The negative conclusion in the Comment of Becker, Schlicher, and Scully about electromagnetic enhancement of beta decay is shown to be faulty. They have found an algebraic oversight in my paper, but correction of that oversight yields results strongly resembling the original. Becker, Schlicher, and Scully fail to find this. They then conduct an analysis which is highly implicit and incomplete. In attempting to analyze their very complicated expressions they claim not to find significant electromagnetic effects. Yet they also lose completely the electron retardation term of conventional forbidden beta decay. When they attempt to explain the difference between their results and mine, they misconstrue the momentum-translation technique and end up in a logical contradiction. They attempt also to apply a ''no-go'' theorem applicable only to plane-wave particles to my theory, which is built around the use of bound-state nuclear wave functions. This makes the no-go theorem inapplicable

  19. Forbidden transitions in excitation by electron impact in Co3+: an R-matrix approach

    International Nuclear Information System (INIS)

    Stancalie, V

    2011-01-01

    Collision strengths for the electron-impact excitation of forbidden transitions between 136 terms arising from 3d 6 , 3d 5 4s and 3d 5 4p configurations of Co 3+ have been calculated using the R-matrix method. The accuracy of a series of models for the target terms was considered, which form the basis for R-matrix collision calculations. The importance of including configuration interaction wave functions both in the target-state expansion and in the (N+1)-electron quadratically integrable function expansion is discussed. Collision strengths were calculated for incident electron energies up to 6 Ryd. These results are believed to be the first such values for this system and will be important for plasma modelling.

  20. Communication: Proper treatment of classically forbidden electronic transitions significantly improves detailed balance in surface hopping

    Energy Technology Data Exchange (ETDEWEB)

    Sifain, Andrew E. [Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0485 (United States); Wang, Linjun [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China); Prezhdo, Oleg V. [Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0485 (United States); Department of Chemistry, University of Southern California, Los Angeles, California 90089-1062 (United States)

    2016-06-07

    Surface hopping is the most popular method for nonadiabatic molecular dynamics. Many have reported that it does not rigorously attain detailed balance at thermal equilibrium, but does so approximately. We show that convergence to the Boltzmann populations is significantly improved when the nuclear velocity is reversed after a classically forbidden hop. The proposed prescription significantly reduces the total number of classically forbidden hops encountered along a trajectory, suggesting that some randomization in nuclear velocity is needed when classically forbidden hops constitute a large fraction of attempted hops. Our results are verified computationally using two- and three-level quantum subsystems, coupled to a classical bath undergoing Langevin dynamics.

  1. Radiative Rates for Forbidden Transitions in Doubly-Ionized Fe-Peak Elements

    Science.gov (United States)

    Fivet, Vanessa; Quinet, P.; Bautista, M.

    2012-05-01

    Accurate and reliable atomic data for lowly-ionized Fe-peak species (Sc, Ti, V, Cr, Mn, Fe, Co, Ni and Cu) are of paramount importance for the analysis of the high resolution astrophysical spectra currently available. The third spectra of several iron group elements have been observed in different galactic sources like Herbig-Haro objects in the Orion Nebula [1] and stars like Eta Carinae [2]. However, forbidden transitions between low-lying metastable levels of doubly-ionized iron-peak ions have been very little investigated so far and radiative rates for those lines remain sparse or inexistent. We are carrying out a systematic study of the electronic structure of doubly-ionized iron-peak elements. The magnetic dipole (M1) and electric quadrupole (E2) transition probabilities are computed using the pseudo-relativistic Hartree-Fock (HFR) code of Cowan [3] and the central Thomas-Fermi-Dirac potential approximation implemented in AUTOSTRUCTURE [4]. This multi-platform approach allows for consistency checks and intercomparison and has proven very successful in the study of the complex Fe-peak species where many different effects contribute [5]. References [1] A. Mesa-Delgado et al., MNRAS 395 (2009) 855 [2] S. Johansson et al., A&A 361 (2000) 977 [3] R.D. Cowan, The Theory of Atomic Structure and Spectra, Berkeley: Univ. California Press (1981) [4] N.R. Badnell, J. Phys. B: At. Mol. Opt. Phys. 30 (1997) 1 [5] M. Bautista et al., ApJ 718 (2010) L189

  2. Large-scale evaluation of β -decay rates of r -process nuclei with the inclusion of first-forbidden transitions

    Science.gov (United States)

    Marketin, T.; Huther, L.; Martínez-Pinedo, G.

    2016-02-01

    Background: r -process nucleosynthesis models rely, by necessity, on nuclear structure models for input. Particularly important are β -decay half-lives of neutron-rich nuclei. At present only a single systematic calculation exists that provides values for all relevant nuclei making it difficult to test the sensitivity of nucleosynthesis models to this input. Additionally, even though there are indications that their contribution may be significant, the impact of first-forbidden transitions on decay rates has not been systematically studied within a consistent model. Purpose: Our goal is to provide a table of β -decay half-lives and β -delayed neutron emission probabilities, including first-forbidden transitions, calculated within a fully self-consistent microscopic theoretical framework. The results are used in an r -process nucleosynthesis calculation to asses the sensitivity of heavy element nucleosynthesis to weak interaction reaction rates. Method: We use a fully self-consistent covariant density functional theory (CDFT) framework. The ground state of all nuclei is calculated with the relativistic Hartree-Bogoliubov (RHB) model, and excited states are obtained within the proton-neutron relativistic quasiparticle random phase approximation (p n -RQRPA). Results: The β -decay half-lives, β -delayed neutron emission probabilities, and the average number of emitted neutrons have been calculated for 5409 nuclei in the neutron-rich region of the nuclear chart. We observe a significant contribution of the first-forbidden transitions to the total decay rate in nuclei far from the valley of stability. The experimental half-lives are in general well reproduced for even-even, odd-A , and odd-odd nuclei, in particular for short-lived nuclei. The resulting data table is included with the article as Supplemental Material. Conclusions: In certain regions of the nuclear chart, first-forbidden transitions constitute a large fraction of the total decay rate and must be

  3. Photoabsorption Spectrum and Optically Forbidden Transitions of Krypton by Electron Impact

    Institute of Scientific and Technical Information of China (English)

    苑震生; 朱林繁; 李文斌; 成华东; 徐克尊

    2002-01-01

    A high resolution fast electron energy loss spectrometer with multi-channel energy analysis was employed. The maxima just above the threshold 4p-1(2P1/2), which is regarded as a shape resonance, was obtained at 16.3 eV. The optically forbidden excitations of 4s electron were measured for the first time, and the energy positions are 23.75 eV(4s-15s), 25.66 eV (4s-16s/4d) and 26.60 eV(4s-17s/5d).

  4. Exotic nuclear beta transitions astrophysical examples

    CERN Document Server

    Takahashi, K

    1981-01-01

    A theoretical study of nuclear beta -transitions under various astrophysical circumstances is reviewed by illustrative examples: 1) continuum-state electron captures in a matter in the nuclear statistical equiplibrium, and ii) bound-state beta -decays in stars in connection with a cosmochronometer and with the s-process branchings. (45 refs).

  5. Four-quasiparticle isomers and K-forbidden transitions in 176Lu

    International Nuclear Information System (INIS)

    McGoram, T.R.; Dracoulis, G.D.; Kibedi, T.; Mullins, M.; Byrne, A.P.; Baxter, A.M.

    2000-01-01

    Full text: The odd-odd nucleus 176 Lu has been the subject of extensive experimental and theoretical investigation over the last forty years. Much of this interest has stemmed from the role of 176 Lu in the s-process in nucleosynthesis. From a nuclear structure perspective, 176 Lu resides in a region of the nuclear chart where collective rotation and high-K, multi-quasiparticle states compete to form the yrast line (the locus of state with the lowest energy at a given angular momentum). The electromagnetic decay of intermediate and high-K states is often hindered due to the K-selection rule, while apparent violations of this selection rule have been ascribed to Coriolis mixing, shape changes in the gamma-degree of freedom, and so-called 'statistical' mixing. The relative importance of these mechanisms remains an open question. We present here the results of gamma-ray and conversion-electron spectroscopic measurements, performed at the Heavy Ion Facility at the Australian National University in Canberra, using the reaction 176 Yb( 7 Li, α3n) at a beam energy of 45 MeV. Two new four-quasiparticle isomers have been established, with mean lives of 400(100)ns and 58(5)μs, and spin projections and parities of 12 + and (14 + ) respectively. The shorter--lived isomer displays both normal and anomalous K-forbidden decays, which we show is the result of two-state mixing between the isomeric state and a member of a two-quasiparticle rotational band. The implied mixing matrix element of only 5 eV shows explicitly that very small mixing matrix elements may be responsible for anomalous K-hindered decays

  6. Forbidden transitions in the EPR spectrum of the ferric ion cubic symmetry in magesium oxide

    Energy Technology Data Exchange (ETDEWEB)

    de Biasi, R S [Instituto Militar de Engenharia, Rio de Janeiro (Brazil). Secao de Engenharia e Ciencia dos Materiais

    1979-03-01

    The spectrum of the ..delta..m /sub s/=2 transitions of Fe/sup 3 +/ in cubic symmetry sites in MgO has been measured at 9.25GHz. The orientation dependence of the transitions is found to be consistent with a spin Hamiltonian of cubic symmetry with g=2.0037(isotropic), a=0.0205/sup +/-0.00005 cm/sup -1/.

  7. Electron impact excitation of Fe-peak elements: forbidden transitions in the 3d5 manifold of Fe IV

    International Nuclear Information System (INIS)

    McLaughlin, B M; Hibbert, A; Scott, M P; Noble, C J; Burke, V M; Burke, P G

    2005-01-01

    Electron-impact excitation collision strengths of the Fe-peak element Fe IV are calculated in the close-coupling approximation using the R-matrix suite of codes PRMAT designed for parallel processors. One hundred and eight LS-coupled states arising from the 3d 5 , 3d 4 4s and 3d 4 4p configurations of Fe IV, are retained in the present calculations. Detailed multi-configuration interaction target wavefunctions are used with the aid of 3p 2 → 3d 2 electron promotions and a 4dbar correlation orbital in the present calculations. Effective collision strengths for optically forbidden transitions, which are extremely important in the analysis of lines in the Fe IV spectra, are obtained by averaging the electron collision strengths for a wide range of incident electron energies, over a Maxwellian distribution of velocities. Results are presented for electron temperatures (T e in Kelvin) in the range 3.3 ≤ Log T e ≤ 6.0 applicable to many laboratory and astrophysical plasmas for transitions within the 3d 5 manifold. The present results compared to previous investigations provide improved results for important lines in the Fe IV spectrum

  8. A systematic and detailed investigation of radiative rates for forbidden transitions of astrophysical interest in doubly ionized iron peak elements

    Science.gov (United States)

    Quinet, Pascal; Fivet, Vanessa; Bautista, Manuel

    2015-08-01

    The knowledge of accurate and reliable atomic data for lowly ionized iron peak elements, from scandium to copper, is of paramount importance for the analysis of the high resolution spectra currently available. The third spectra of several iron group elements have been observed in different galactic sources like Herbig-Haro objects in the Orion Nebula [1] and stars like Eta Carinae [2]. However, forbidden transitions between low-lying metastable levels of doubly ionized species have been little investigated so far and radiative rates for those lines remain sparse or inexistent.In the present contribution, we report on the recent study we have performed concerning the determination of magnetic dipole (M1) and electric quadrupole (E2) transition probabilities in those ions. For the calculations, we have extensively used the pseudo-relativistic Hartree-Fock (HFR) code of Cowan [3] and the central Thomas-Fermi-Dirac potential approximation implemented in AUTOSTRUCTURE [4]. This multi-platform approach allowed us to check the consistency and to assess the accuracy of the results obtained.[1] Mesa-Delgado A. et al., MNRAS 395, 855 (2009)[2] Johansson S. et al., A&A 361, 977 (2000)[3] Cowan R.D., The Theory of Atomic Structure and Spectra, Univ. California Press, Berkeley (1981)[4] Badnell N.R., J. Phys. B: At. Mol. Opt. Phys. 30, 1 (1997)

  9. Detection of forbidden Singlet-Triplet Transitions of 12C16O

    CSIR Research Space (South Africa)

    Steenkamp, CM

    2010-09-01

    Full Text Available Twenty rovibronic transitions of the e(v'=5)-X(v''=0) band of the 12C16O which experimental wavelengths were previously unavailable were recently detected by vr induced fluorescence excitation spectroscopy. The data is important in astrophysical...

  10. Forbidden optical transition in Ti-like Xe, Ba, and Ir

    International Nuclear Information System (INIS)

    Bekker, H.; Windberger, A.; Binder, M.; López-Urrutia, J. R. Crespo; Versolato, O. O.; Klawitter, R.

    2015-01-01

    We present measurements of the (3d 4 ) 5 D 2 − 5 D 3 transitions in the Ti-like ions Xe 32+ , Ba 34+ , and Ir 55+ produced and trapped in the Heidelberg electron beam ion trap. The obtained wavelengths have a precision at the few ppm-level and are thereby the most precise measurements of these transitions up to date. For Z=60−75 semi-empirical calculations have shown excellent agreement, however our measurements combined with data from other works shows that outside this range predictions quickly deviate. The value obtained for Ir 55+ 357.434(2) nm confirms the linear mismatch to ab initio calculations for Z > 70, as hypothesized in Utter et al., Phys. Rev. A 67, 012508 (2003)

  11. Symmetry-forbidden intervalley scattering by atomic defects in monolayer transition-metal dichalcogenides

    DEFF Research Database (Denmark)

    Kaasbjerg, Kristen; Martiny, Johannes H. J.; Low, Tony

    2017-01-01

    protectionmechanism against intervalley scattering in monolayer TMDs. The predicteddefectdependent selection rules for intervalley scattering can be verified viaFourier transform scanning tunneling spectroscopy (FT-STS), and provide aunique identification of, e.g., atomic vacancy defects (M vs X). Our findingsare......Intervalley scattering by atomic defects in monolayer transition metaldichalcogenides (TDMs; MX2) presents a serious obstacle for applicationsexploiting their unique valley-contrasting properties. Here, we show that thesymmetry of the atomic defects can give rise to an unconventional...

  12. (5/2-→5/2+) 803 keV beta transition in 147Nd

    International Nuclear Information System (INIS)

    Lakshminarayana, S.; Srinivasa Rao, M.; Seshagiri Rao, V.; Sastry, D.L.

    1978-01-01

    The existing experimental results on the 5/2 - →5/2 + 803 keV beta transition in 147 Nd are mutually contradictory to classify it under xi-approximation. To resolve this contradiction, the β-γ directional correlations are performed carefully as a function of energy using a conventional fast-slow coincidence scintillation system. The attenuation factor G 2 in this case turns out to be 0.64 +- 0.05. The results on the longitudinal electron polarization and the shape measurements are combined with the present results and an attempt is made to extract the nuclear matrix elements governing this first forbidden non-unique beta transition following Simm's formalism. Results are discussed based on the final sets of matrix elements. (auth.)

  13. One step beyond the electric dipole approximation: An experiment to observe the 5p → 6p forbidden transition in atomic rubidium

    Science.gov (United States)

    Ponciano-Ojeda, F.; Hernández-Gómez, S.; Mojica-Casique, C.; Ruiz-Martínez, E.; López-Hernández, O.; Colín-Rodríguez, R.; Ramírez-Martínez, F.; Flores-Mijangos, J.; Sahagún, D.; Jáuregui, R.; Jiménez-Mier, J.

    2018-01-01

    An advanced undergraduate experiment to study the 5 P 3 / 2 → 6 P 3 / 2 electric quadrupole transition in rubidium atoms is presented. The experiment uses two external cavity diode lasers, one operating at the D2 rubidium resonance line and the other built with commercial parts to emit at 911 nm. The lasers produce the 5 s → 5 p → 6 p excitation sequence in which the second step is the forbidden transition. Production of atoms in the 6 P 3 / 2 state is observed by detection of the 420 nm fluorescence that results from electric dipole decay into the ground state. Lines whose widths are significantly narrower than the Doppler width are used to study the hyperfine structure of the 6 P 3 / 2 state in rubidium. The spectra illustrate characteristics unique to electric dipole forbidden transitions, like the electric quadrupole selection rules; they are also used to show general aspects of two-color laser spectroscopy such as velocity selection and hyperfine pumping.

  14. BETA SPECTRA. I. Negatrons spectra

    International Nuclear Information System (INIS)

    Grau Malonda, A.; Garcia-Torano, E.

    1978-01-01

    Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

  15. [Detection of the lethal process in plankton noctiluca by means of a forbidden transition of ESR of Mn2+ ion].

    Science.gov (United States)

    Kamenev, S E; Kopvillem, U Kh; Pasynkov, A S; Sharipov, R Z

    1981-01-01

    A forbidden ESR line of Mn2+ that is connected with the penetration of Mn into the plancton organism and binding it to a marcomolecule is selected from the experiment. A method for saturating the plancton organism with paramagnetic ions is proposed. It is shown that the constant of the axial electric field in the spin hamiltonian of Mn2+ ion described the dynamics of a selforganizing system. It is tested that the lethal process in the plancton with paramagnetic ion enrichment originated from boson avalanche. Experiments are performed with plancton noctiluca which illustrate the occurrence of avalancheline lethal process in the case of paramagnetic ion enrichment with limiting concentration. The meaning of these results for the problems of oceanology and pollution-ocean inhabitants interaction in the case of paramagnetic ions is discussed.

  16. Calculation of parity violating effects in the 62P/sub 1/2/-72P/sub 1/2/ forbidden M1 transition in thallium

    International Nuclear Information System (INIS)

    Neuffer, D.B.

    1977-05-01

    Calculations are presented of the E1 amplitude expected in forbidden M1 transitions of Tl and Cs if parity is violated in the neutral weak e-N interaction, as proposed in a number of gauge models, including that of Weinberg and Salam. Valence electron wave functions are generated as numerical solutions to the Dirac equation in a modified Tietz central potential. These wave functions are used to calculate allowed E1 transition rates, hfs splittings, and Stark E1 transition ampitudes. These results are compared with experiment and the agreement is generally good. The relativistic Tl 6 2 P/sub 1/2/-7 2 P/sub 1/2/ M1 transition amplitude M is also calculated, and corrections due to interconfiguration interaction, Breit interaction, and hfs mixing are included. The parity violating E1 amplitude E/sub PV/ is calculated and a value for the circular dichroism in the Weinberg model delta = -2.6 x 10 -3 is obtained. Parity violating effects in other Tl transitions are discussed. Contributions to the M1 amplitude for the forbidden Cs 6 2 S/sub 1/2/-7 2 S/sub 1/2/ and 6 2 S/sub 1/2/-8 2 S/sub 1/2/ transitions and to the Cs 6 2 S/sub 1/2/ g-factor anomaly from relativistic effects, Breit interaction, interconfiguration interaction, and hfs mixing are calculated, and it is found that this current theoretical description is not entirely adequate. The parity violating E1 amplitude E/sub PV/ for the 6S/sub 1/2/-7 2 S/sub 1/2/ and 6S/sub 1/2/-8 2 S/sub 1/2/ transitions is evaluated. With a measured value M/sub expt/ and the Weinberg value Q/sub W/ = -99, a circular dichroism delta = 1.64 x 10 -4 for the 6 2 S/sub 1/2/-7 2 S/sub 1/2/ transition is found

  17. Beta transition rates in hot and dense matter

    International Nuclear Information System (INIS)

    Takahashi, K.; El Eid, M.F.; Hillebrandt, W.

    1977-05-01

    Allowed and first-forbidden transition rates of β +- decays and e +- captures under stellar conditions of high temperatures and high densities are reformulated. The present paper mainly describes the formalism which is essentially based on the gross theory of nuclear β-decays, but also contains the numerical results of the transition rates of nuclei with the mass number 56. The discussion includes a short but critical review of several different approaches to the astrophysical β-transitions of nuclei as well as of the neutron and proton. Further results of the transition rates and the neutrino energy losses will soon be presented elsewhere as simple functions of temperature and density for many nuclei, together with an application to collapsing massive stars. (orig.) [de

  18. Beta spectra. II-Positron spectra

    International Nuclear Information System (INIS)

    Grau, A.; Garcia-Torano, E.

    1981-01-01

    Using the Fermi theory of beta decay, the beta spectra for 30 positron emitters have been computed, introducing a correction factor for unique forbidden transitions. The spectra are ploted vs. energy, once normalised, and tabulated with the related Fermi functions. The average and median energies are calculated. (author)

  19. Observation of the Forbidden Magnetic Dipole Transition 6{sup 2}P{sub ½} --> 7{sup 2}P{sub ½} in Atomic Thallium

    Science.gov (United States)

    Chu, S.

    1976-10-01

    A measurement of the 6{sup 2}P{sub ½} --> 7{sup 2}P{sub ½} forbidden magnetic dipole matrix element in atomic thallium is described. A pulsed, linearly polarized dye laser tuned to the transition frequency is used to excite the thallium vapor from the 6{sup 2}P{sub ½} ground state to the 7{sup 2}P{sub ½} excited state. Interference between the magnetic dipole M1 amplitude and a static electric field induced E1 amplitude results in an atomic polarization of the 7{sup 2}P{sub ½} state, and the subsequent circular polarization of 535 nm fluorescence. The circular polarization is seen to be proportional to / as expected, and measured for several transitions between hyperfine levels of the 6{sup 2}P{sub ½} and 7{sup 2}P{sub ½} states. The result is = -(2.11 +- 0.30) x 10{sup -5} parallel bar e parallel bar dirac constant/2mc, in agreement with theory.

  20. RPC Calculations for K-forbidden Transitions in {sup 183}W, Evidence for Large Inertial Parameter Connected with High-lying Rotational Bands

    Energy Technology Data Exchange (ETDEWEB)

    Malmskog, S G [AB Atomenergi, Nykoeping (Sweden); Wahlborn, S [Div. of Theore tical Physics, Royal Inst. of Technology Stockholm (Sweden)

    1967-09-15

    Recent measurements have shown that the transitions deexciting the 453 keV 7/2{sup -} level in {sup 183}W to the K = 1/2{sup -} and 3/2{sup -} bands are strongly retarded. The data for B(M1) and B(E2) are analyzed in terms of the RPC model (rotation + particle motion + coupling). With the {delta}K = 1 (Coriolis) coupling, the K-forbidden M1-transitions proceed via admixtures of high-lying 5/2{sup -} bands. A reasonable and unambiguous fit to the data is obtained by varying the strength of the coupling. Allowing for various uncertainties and corrections, one finds that the inertial parameter (the inverse of the coupling constant, i. e. 2J(2{pi}){sup 2}/({Dirac_h}){sup 2} may have values between roughly 1 and 3 times the rigid rotator value of 2J(2{pi}){sup 2}/({Dirac_h}){sup 2}, thus being unexpectedly large. Calculations with the {delta}K=2 coupling were also performed and turn out not to give better agreement with experiment.

  1. Remote sensing of atomic oxygen: Some observational difficulties in the use of the forbidden O I λ 1173-angstrom and O I λ 1641-angstrom transitions

    International Nuclear Information System (INIS)

    Erdman, P.W.; Zipf, E.C.

    1987-01-01

    Recent sounding rocket and satellite studies suggest that simultaneous measurements of the O I λ989-angstrom and λ1,304-angstrom resonance lines and of the forbidden λ1,172.6-angstrom and λ1641.3-angstrom transitions which also originate from the 3s'3D degree and 3s 3S degree states would form the basis of a useful remote sensing technique for measuring the O I density and optical of a planetary or stellar atmosphere. Because the λ1,172.6-angstrom and λ1641.3-angstrom emissions are weak lines and are emitted in a wavelength region rich in spectral features, it is important to determine whether typical flight instruments can make measurements with sufficient spectral purity so that the remote sensing observations will yield accurate results. We have made a detailed, high-resolution study of the far ultraviolet emission features in the regions surrounding the atomic oxygen transitions at λ1,172.6-angstrom and λ1,641.3-angstrom. These spectra, which were excited by electron impact on O 2 and N 2 , are presented in an attempt to display some potential sources of interference in aeronomical measurements of these O I lines. Both atomic and molecular emissions are found, and the spectral resolution necessary to make unambiguous measurements is discussed

  2. Observation of strongly forbidden solid effect dynamic nuclear polarization transitions via electron-electron double resonance detected NMR

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Albert A.; Corzilius, Björn; Haze, Olesya; Swager, Timothy M.; Griffin, Robert G., E-mail: rgg@mit.edu [Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2013-12-07

    We present electron paramagnetic resonance experiments for which solid effect dynamic nuclear polarization transitions were observed indirectly via polarization loss on the electron. This use of indirect observation allows characterization of the dynamic nuclear polarization (DNP) process close to the electron. Frequency profiles of the electron-detected solid effect obtained using trityl radical showed intense saturation of the electron at the usual solid effect condition, which involves a single electron and nucleus. However, higher order solid effect transitions involving two, three, or four nuclei were also observed with surprising intensity, although these transitions did not lead to bulk nuclear polarization—suggesting that higher order transitions are important primarily in the transfer of polarization to nuclei nearby the electron. Similar results were obtained for the SA-BDPA radical where strong electron-nuclear couplings produced splittings in the spectrum of the indirectly observed solid effect conditions. Observation of high order solid effect transitions supports recent studies of the solid effect, and suggests that a multi-spin solid effect mechanism may play a major role in polarization transfer via DNP.

  3. BETA SPECTRA. I. Negatrons spectra; ESPECTROS BETA. I. Espectros simples de negatrones

    Energy Technology Data Exchange (ETDEWEB)

    Grau Malonda, A; Garcia-Torano, E

    1978-07-01

    Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

  4. Rare and forbidden decays

    CERN Document Server

    Trampetic, Josip

    2002-01-01

    In these lectures I first cover radiative and semileptonic B decays, including the QCD corrections for the quark subprocesses. The exclusive modes and the evaluation of the hadronic matrix elements, i.e. the relevant hadronic form factors, are the second step. Small effects due to the long-distance, spectator contributions, etc. are discussed next. The second section we started with non-leptonic decays, typically $B \\to \\pi\\pi, K\\pi, \\rho\\pi,...$ We describe in more detail our prediction for decays dominated by the $b\\to s \\eta_c$ transition. Reports on the most recent experimental results are given at the end of each subsection. In the second part of the lectures I discuss decays forbidden by the Lorentz and gauge invariance, and due to the violation of the angular moment conservation, generally called the Standard Model-forbiden decays. However, the non-commutative QED and/or non-commutative Standard Model (NCSM), developed in a series of works in the last few years allow some of those decay modes. These ar...

  5. Parity-Forbidden Transitions and Their Impact on the Optical Absorption Properties of Lead-Free Metal Halide Perovskites and Double Perovskites.

    Science.gov (United States)

    Meng, Weiwei; Wang, Xiaoming; Xiao, Zewen; Wang, Jianbo; Mitzi, David B; Yan, Yanfa

    2017-07-06

    Using density functional theory calculations, we analyze the optical absorption properties of lead (Pb)-free metal halide perovskites (AB 2+ X 3 ) and double perovskites (A 2 B + B 3+ X 6 ) (A = Cs or monovalent organic ion, B 2+ = non-Pb divalent metal, B + = monovalent metal, B 3+ = trivalent metal, X = halogen). We show that if B 2+ is not Sn or Ge, Pb-free metal halide perovskites exhibit poor optical absorptions because of their indirect band gap nature. Among the nine possible types of Pb-free metal halide double perovskites, six have direct band gaps. Of these six types, four show inversion symmetry-induced parity-forbidden or weak transitions between band edges, making them not ideal for thin-film solar cell applications. Only one type of Pb-free double perovskite shows optical absorption and electronic properties suitable for solar cell applications, namely, those with B + = In, Tl and B 3+ = Sb, Bi. Our results provide important insights for designing new metal halide perovskites and double perovskites for optoelectronic applications.

  6. Laser spectroscopy of the 5P3/2 → 6Pj (j = 1/2 and 3/2) electric dipole forbidden transitions in atomic rubidium

    Science.gov (United States)

    Ponciano-Ojeda, F.; Hernández-Gómez, S.; Mojica-Casique, C.; Hoyos, L. M.; Flores-Mijangos, J.; Ramírez-Martínez, F.; Sahagún, D.; Jáuregui, R.; Jiménez-Mier, J.

    2018-04-01

    Doppler-free optical double-resonance spectroscopy is used to study the 5S1/2 → 5P3/2 → 6Pj (j = 3/2,1/2) excitation sequence in room-temperature rubidium atoms. This involves a 5S1/2 → 5P3/2 electric dipole preparation step followed by the 5P3/2 → 6Pj electric quadrupole excitation. The electric dipole forbidden transitions occur at 911.0 nm (j = 3/2) and 917.5 nm (j = 1/2). Production of atoms in the 6Pj states is detected by observing their direct decay to the ground state through emission of blue photons (λ ≈ 420 nm). A detailed experimental and theoretical study of the dependence on the relative linear polarizations of excitation beams is made. It is shown that specific electric quadrupole selection rules over magnetic quantum numbers are directly related to the relative orientation of the linear polarization of the excitation beams.

  7. Electron collisions with Fe-peak elements: Forbidden transitions between the low lying valence states 3d6, 3d54s, and 3d54p of Fe III

    International Nuclear Information System (INIS)

    McLaughlin, B.M.; Scott, M.P.; Sunderland, A.G.; Noble, C.J.; Burke, V.M.; Ramsbottom, C.A.; Reid, R.H.G.; Hibbert, A.; Bell, K.L.; Burke, P.G.

    2007-01-01

    Effective collision strengths are presented for the Fe-peak element Fe III at electron temperatures (T e in degrees Kelvin) in the range 2 x 10 3 to 1 x 10 6 . Forbidden transitions results are given between the 3d 6 , 3d 5 4s, and the 3d 5 4p manifolds applicable to the modeling of laboratory and astrophysical plasmas

  8. Iron forbidden lines in tokamak discharges

    International Nuclear Information System (INIS)

    Suckewer, S.; Hinnov, E.

    1979-03-01

    Several spectrum lines from forbidden transitions in the ground configurations of highly ionized atoms have been observed in the PLT tokamak discharges. Such lines allow localized observations, in the high-temperature regions of the plasma, of ion-temperatures, plasma motions, and spatial distributions of ions. Measured absolute intensities of the forbidden lines have been compared with simultaneous observations of the ion resonance lines and with model calculations in order to deduce the mechanism of level populaions by means of electron collisions and radiative transitions

  9. Iron forbidden lines in tokamak discharges

    Energy Technology Data Exchange (ETDEWEB)

    Suckewer, S.; Hinnov, E.

    1979-03-01

    Several spectrum lines from forbidden transitions in the ground configurations of highly ionized atoms have been observed in the PLT tokamak discharges. Such lines allow localized observations, in the high-temperature regions of the plasma, of ion-temperatures, plasma motions, and spatial distributions of ions. Measured absolute intensities of the forbidden lines have been compared with simultaneous observations of the ion resonance lines and with model calculations in order to deduce the mechanism of level populaions by means of electron collisions and radiative transitions.

  10. Beta relaxation of nonpolymeric liquids close to the glass transition

    DEFF Research Database (Denmark)

    Olsen, Niels Boye; Christensen, Tage Emil; Dyre, Jeppe

    2000-01-01

    Dielectric beta relaxation in a pyridine-toluene solution is studied close to the glass transition. Loss peak frequency and maximum loss both exhibit thermal hysteresis. An annealing-state-independent parameter involving loss and loss peak frequency is identified. This parameter has a simple...

  11. Modeling dynamic beta-gamma polymorphic transition in Tin

    Science.gov (United States)

    Chauvin, Camille; Montheillet, Frank; Petit, Jacques; CEA Gramat Collaboration; EMSE Collaboration

    2015-06-01

    Solid-solid phase transitions in metals have been studied by shock waves techniques for many decades. Recent experiments have investigated the transition during isentropic compression experiments and shock-wave compression and have highlighted the strong influence of the loading rate on the transition. Complementary data obtained with velocity and temperature measurements around the polymorphic transition beta-gamma of Tin on gas gun experiments have displayed the importance of the kinetics of the transition. But, even though this phenomenon is known, modeling the kinetic remains complex and based on empirical formulations. A multiphase EOS is available in our 1D Lagrangian code Unidim. We propose to present the influence of various kinetic laws (either empirical or involving nucleation and growth mechanisms) and their parameters (Gibbs free energy, temperature, pressure) on the transformation rate. We compare experimental and calculated velocities and temperature profiles and we underline the effects of the empirical parameters of these models.

  12. Method and apparatus for induced nuclear beta decay

    International Nuclear Information System (INIS)

    Reiss, H.

    1986-01-01

    This invention relates to a method and apparatus for inducing beta decay transition that are normally inhibited by angular momentum or parity considerations. According to one aspect of this invention a method of inducing nuclear beta decay transition comprises providing a medium which includes atomic nuclei that have forbidden beta decay transition in which the initial and final nuclear states do not have the same intrinsic parity or have total angular momenta which differ by more than one quantum unit of angular momentum, and applying to the medium an electromagnetic field which has an intensity sufficient to provide the angular momentum or intrinsic parity necessary to overcome the forbiddenness of the beta decay transition of the atomic nuclei, thereby to induce the beta decay transitions. According to another aspect of this invention an apparatus for inducing beta decay transition comprises a medium which includes atomic nuclei that have forbidden beta decay transitions in which the initial and final nuclear states do not have the same intrinsic parity or have total angular momenta which differ by more than one quantum unit of angular momentum, field producing means for producing an electromagnetic field in the medium and means for energising the field producing means to establish the field at an intensity sufficient to provide the angular momentum or intrinsic parity necessary to overcome the forbiddenness of the beta decay transitions of the atomic nuclei. The energy released in these induced nuclear transition is useful for the controlled production of power. The induced beta dacay transitions are also useful to reduce the halflives of long-lived fission product wastes from conventional nuclear fission power plants

  13. Isospin impurity and super-allowed {beta} transitions; Impurite d`isospin et transitions {beta} super-permises

    Energy Technology Data Exchange (ETDEWEB)

    Sagawa, H. [Center for Mathematical Science, University of Aizu, Aizu-Wakamatsu, Fukushima 965 (Japan); Van Giai Nguyen [Theoretical Physics Division, Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France); Suzuki, T. [Department of Physics, Nihon University, Tokyo 156 (Japan)

    1999-10-01

    We study the effect of isospin impurity on the super-allowed Fermi {beta} decay using microscopic HF and RPA (or TDA) model taking into account CSB and CIB interactions. It is found that the isospin impurity of N = Z nuclei gives enhancement of the sum rule of Fermi transition probabilities. On the other hand, the super-allowed transitions between odd-odd J = 0 nuclei and even-even J = 0 nuclei are quenched because on the cancellation of the isospin impurity effects of mother and daughter nuclei. An implication of the calculated Fermi transition rate on the unitarity of Cabbibo-Kobayashi-Maskawa mixing matrix is also discussed. (authors) 3 refs., 1 fig.

  14. The Forbidden Signs

    DEFF Research Database (Denmark)

    Kilstrup, Mogens

    2016-01-01

    While the field of semiotics has been active since it was started by Peirce, it appears like the last decade has been especially productive with a number of important new concepts being developed within the biosemiotics community. The novel concept of the Semiotic scaffold by Hoffmeyer is an impo......While the field of semiotics has been active since it was started by Peirce, it appears like the last decade has been especially productive with a number of important new concepts being developed within the biosemiotics community. The novel concept of the Semiotic scaffold by Hoffmeyer...... is an important addition that offers insight into the hardware requirements for bio-semiosis. As any type of semiosis must be dependent upon Semiotic scaffolds, I recently argued that the process of semiosis has to be divided into two separate processes of sign establishment and sign interpretation....... I also show that biological semiosis offers examples of forbidden signs, where the faulty interpretation of signs may lead to decimation of whole evolutionary lines of organisms. A new concept of Evolutionary memory which is applicable to both human and biological semiosis is explained...

  15. 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.)

  16. Giant first-forbidden resonances

    International Nuclear Information System (INIS)

    Krmpotic, F.; Nakayama, K.; Sao Paulo Univ.; Pio Galeao, A.; Sao Paulo Univ.

    1983-01-01

    Recent experimental data on first-forbidden charge-exchange resonances are discussed in the framework of a schematic model. We also evaluate the screening of the weak coupling constants induced by both the giant resonances and the δ-isobar. It is shown that the last effect does not depend on the multipolarity of the one-particle moment. Due to the same reason, the fraction of the reaction strength pushed up into the δ-resonance region is always the same regardless of the quantum numbers carried by the excitation. Simple expressions are derived for the dependence of the excitation energies of the first-forbidden giant resonances on the mass number and isospin of the target. The model reproduces consistently both the Gamow-Teller and the first-forbidden resonances. (orig.)

  17. Beta decay to the second 2+ excited state of 122Te

    International Nuclear Information System (INIS)

    Hayashi, Takeo; Yamada, Shigeru

    1976-01-01

    The first-forbidden beta transition in Sb-122 was studied by the angular correlation experiment and the beta-spectra. The special precautions were paid for counting the beta particles having energy lower than 750 keV in the beta-gamma angular correlation measurement. The sources of Sb-122 were obtained by irradiating enriched Sb-121 in the Kyoto University reactor. The reduced beta coefficient R(E) was obtained from the angular correlation function. The beta spectrum measurement was performed with a sector type double focusing beta-ray spectrometer. The R(E) values for the beta transitions were analyzed by using the simplex method as used by Manthuruthil and Poirier to compare the angular correlation data with the exact formula given by Morita and Morita. Sets of the nuclear matrix parameters thus obtained show that the condition for the cancellation effect is satisfied in the beta transition. (Kato, T.)

  18. Transient formation of forbidden lines

    International Nuclear Information System (INIS)

    Rosmej, F.B.; Rosmej, O.N.

    1996-01-01

    An explanation of anomalously long time scales in the transient formation of forbidden lines is proposed. The concept is based on a collisionally induced density dependence of the relaxation times of metastable level populations in transient plasma. Generalization leads to an incorporation of diffusion phenomena. We demonstrate this new concept for the simplest atomic system: the He-like isoelectronic sequence. A new interpretation of the observed long duration and anomalously high intensity of spin-forbidden emission in hot plasmas is given. (author)

  19. Transient formation of forbidden lines

    Energy Technology Data Exchange (ETDEWEB)

    Rosmej, F.B. [Bochum Univ., Ruhr (Germany). Inst. fuer Experimentalphysik V; Rosmej, O.N. [VNIIFTRI, Moscow Region (Russian Federation). MISDC

    1996-05-14

    An explanation of anomalously long time scales in the transient formation of forbidden lines is proposed. The concept is based on a collisionally induced density dependence of the relaxation times of metastable level populations in transient plasma. Generalization leads to an incorporation of diffusion phenomena. We demonstrate this new concept for the simplest atomic system: the He-like isoelectronic sequence. A new interpretation of the observed long duration and anomalously high intensity of spin-forbidden emission in hot plasmas is given. (author).

  20. First observation of the strongly forbidden transition 1S0 - 3P0 in Strontium, for an atomic clock with trapped atoms

    International Nuclear Information System (INIS)

    Courtillot, I.

    2003-11-01

    This thesis reports the first results towards the realization of an optical clock using trapped strontium atoms. This set up would combine advantages of the different approaches commonly used to develop an atomic frequency standard. The first part describes the cold atoms source which is implemented. A magneto-optical trap operating on the 1 S 0 - 1 P 1 transition at 461 nm is loaded from an atomic beam decelerated by a Zeeman slower. The 461 nm laser is obtained by sum-frequency mixing in a potassium titanyl phosphate (KTP) crystal. The second part is devoted to the different stages developed to achieve the direct excitation of the 1 S 0 - 3 P 0 clock transition in 87 Sr. This line has a theoretical natural width of 10 -3 Hz. Before this detection, we obtained an estimate of the resonance frequency by measuring absolute frequencies of several allowed optical transitions. (author)

  1. The empirical connection between (p,n) cross sections and beta decay transition strengths

    International Nuclear Information System (INIS)

    Taddeucci, T.N.

    1988-01-01

    A proportionality is assumed to exist between 0/degree/ (p,n) cross sections and the corresponding beta decay transition strengths. The validity of this assumption is tested by comparison of measured (p,n) cross sections and analogous beta decay strengths. Distorted waves impulse approximation calculations also provide useful estimates of the accuracy of the proportionality relationship. 14 refs., 10 figs

  2. Kβ satellite and forbidden transitions in elements with 12 ≤≤ Z ≤≤ 30 induced by electron impact

    International Nuclear Information System (INIS)

    Limandri, Silvina P.; Trincavelli, Jorge C.; Carreras, Alejo C.; Bonetto, Rita D.

    2010-01-01

    The emission of x rays in the Kβ region of Mg, Al, Si, Sc, Ti, Cr, Fe, Ni, and Zn induced by electron bombardment was studied by means of wavelength dispersive spectroscopy. The lines studied were: the Kβ III and Kβ IV spectator hole transitions, the 1s→3s quadrupole decay, the Kβ 2 and Kβ 5 diagram transitions, the structures related to radiative Auger processes, and the Kβ ' and Kβ '' lines. Relative energies and probabilities were determined through a careful spectral processing based on a parameter refinement method. The results obtained were compared with other experimental and theoretical determinations when available.

  3. Penning trap mass spectrometry Q-value determinations for highly forbidden β-decays

    Science.gov (United States)

    Sandler, Rachel; Bollen, Georg; Eibach, Martin; Gamage, Nadeesha; Gulyuz, Kerim; Hamaker, Alec; Izzo, Chris; Kandegedara, Rathnayake; Redshaw, Matt; Ringle, Ryan; Valverde, Adrian; Yandow, Isaac; Low Energy Beam Ion Trap Team

    2017-09-01

    Over the last several decades, extremely sensitive, ultra-low background beta and gamma detection techniques have been developed. These techniques have enabled the observation of very rare processes, such as highly forbidden beta decays e.g. of 113Cd, 50V and 138La. Half-life measurements of highly forbidden beta decays provide a testing ground for theoretical nuclear models, and the comparison of calculated and measured energy spectra could enable a determination of the values of the weak coupling constants. Precision Q-value measurements also allow for systematic tests of the beta-particle detection techniques. We will present the results and current status of Q value determinations for highly forbidden beta decays. The Q values, the mass difference between parent and daughter nuclides, are measured using the high precision Penning trap mass spectrometer LEBIT at the National Superconducting Cyclotron Laboratory.

  4. Polarization of Coronal Forbidden Lines

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hao; Qu, Zhongquan [Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China); Landi Degl’Innocenti, Egidio, E-mail: sayahoro@ynao.ac.cn [Dipartimento di Astronomia e Scienza dello Spazio, Università di Firenze, Largo E. Fermi 2, I-50125 Firenze (Italy)

    2017-03-20

    Since the magnetic field is responsible for most manifestations of solar activity, one of the most challenging problems in solar physics is the diagnostics of solar magnetic fields, particularly in the outer atmosphere. To this end, it is important to develop rigorous diagnostic tools to interpret polarimetric observations in suitable spectral lines. This paper is devoted to analyzing the diagnostic content of linear polarization imaging observations in coronal forbidden lines. Although this technique is restricted to off-limb observations, it represents a significant tool to diagnose the magnetic field structure in the solar corona, where the magnetic field is intrinsically weak and still poorly known. We adopt the quantum theory of polarized line formation developed in the framework of the density matrix formalism, and synthesize images of the emergent linear polarization signal in coronal forbidden lines using potential-field source-surface magnetic field models. The influence of electronic collisions, active regions, and Thomson scattering on the linear polarization of coronal forbidden lines is also examined. It is found that active regions and Thomson scattering are capable of conspicuously influencing the orientation of the linear polarization. These effects have to be carefully taken into account to increase the accuracy of the field diagnostics. We also found that linear polarization observation in suitable lines can give valuable information on the long-term evolution of the magnetic field in the solar corona.

  5. Forbidden Transition Probabilities of Astrophysical Interest among ...

    Indian Academy of Sciences (India)

    It is convenient to think of the Breit–Pauli interac- tion matrix as ... non-zero interactions in the off-diagonal block for the pair of LS terms. Weighted oscillator ... and with the number of electrons outside the common core. Since large orbital sets.

  6. Thermally Induced Alpha-Helix to Beta-Sheet Transition in Regenerated Silk Fibers and Films

    Energy Technology Data Exchange (ETDEWEB)

    Drummy,L.; Phillips, D.; Stone, M.; Farmer, B.; Naik, R.

    2005-01-01

    The structure of thin films cast from regenerated solutions of Bombyx mori cocoon silk in hexafluoroisopropyl alcohol (HFIP) was studied by synchrotron X-ray diffraction during heating. A solid-state conformational transition from an alpha-helical structure to the well-known beta-sheet silk II structure occurred at a temperature of approximately 140 degrees C. The transition appeared to be homogeneous, as both phases do not coexist within the resolution of the current study. Modulated differential scanning calorimetry (DSC) of the films showed an endothermic melting peak followed by an exothermic crystallization peak, both occurring near 140 degrees C. Oriented fibers were also produced that displayed this helical molecular conformation. Subsequent heating above the structural transition temperature produced oriented beta-sheet fibers very similar in structure to B. mori cocoon fibers. Heat treatment of silk films at temperatures well below their degradation temperature offers a controllable route to materials with well-defined structures and mechanical behavior.

  7. Forbidden Channels and SIMP Dark Matter

    OpenAIRE

    Choi Soo-Min; Kang Yoo-Jin; Lee Hyun Min

    2018-01-01

    In this review, we focus on dark matter production from thermal freeze-out with forbidden channels and SIMP processes. We show that forbidden channels can be dominant to produce dark matter depending on the dark photon and / or dark Higgs mass compared to SIMP.

  8. The forbidden beauty of quasicrystals

    International Nuclear Information System (INIS)

    McGrath, R.; Grimm, U.; Diehl, R.

    2005-01-01

    Two decades after they were discovered, the unusual properties of quasicrystals continue to fascinate researchers from a range of disciplines. 20 years ago last month Danny Shechtman of the Technion Institute in Israel announced the discovery of a new metallic alloy. At the time Shechtman had been on sabbatical leave at the National Bureau of Standards in Washington DC, investigating the properties of mixtures of metals that had been melted together and rapidly cooled. He found that one of these alloys - aluminium manganese - displayed a diffraction pattern with 10-fold rotational symmetry. However, such symmetries were supposed to be forbidden by the laws of crystallography. This discovery generated huge excitement, confusion and significant opposition. The Journal of Applied Physics, for example, rejected Shechtman's first paper detailing the discovery on the grounds that it would not interest the physicists who read the journal. Linus Pauling - a giant of 20th-century crystallography - also dismissed the findings. But these early doubts were soon swept away by new experimental evidence, and Shechtman's paper - which was finally published in Physical Review Letters in November 1984 - has since become one of the most-cited research articles in the scientific literature. The strange new materials he had discovered were dubbed quasicrystals, a shorthand form of 'quasiperiodic crystals'. (U.K.)

  9. Search for $\\beta$-transitions with the lowest decay energy for a determination of the neutrino mass

    CERN Multimedia

    From a variety of $\\beta$-transitions only those with decay energies of a few keV and smaller are considered suitable for a determination of the neutrino mass on a sub-eV level. The decay energy of a transition can be very small, if, e.g., in an allowed $\\beta$-decay or electron-capture transition, a nuclear excited state of the daughter nuclide is populated whose energy is very close to the mass difference of the transition nuclides. Investigation of these transitions can also be useful for the assessment of a validity of the current $\\beta$-decay theory in the region of vanishingly small decay energies. The authors of this proposal have found several such $\\beta$-transitions whose decay energies are expected to be extremely small. In order to assess the suitability of these $\\beta$-transitions for the determination of the neutrino mass, measurements of the mass differences of the transition nuclides must be carried out with a sub-keV uncertainty. Presently, only high-precision Penning-trap mass spectrometry...

  10. Contribution to the study of {beta} disintegration and of nuclear structure using experiments on certain {beta}-{gamma} cascades: 198{sub Au}, 86{sub Rb}, 170{sub Tm}; Contribution a l'etude de la desintegration beta et a l'etude de la structure nucleaire a l'aide d'experiences sur certaines cascades beta-gamma: 198{sub Au}, 86{sub Rb}, 170{sub Tm}

    Energy Technology Data Exchange (ETDEWEB)

    Lachkar, J. [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes; Paris-11 Univ., fabulte des Sciences 91 - Orsay (France)

    1969-07-01

    {beta}{gamma} directional angular correlations and shapes of inner beta spectra leading to the first excited level of the final nucleus enable one to determine the nuclear matrix elements typical of the {beta} transition. In the three observed first forbidden cases: {sup 170}Tm, {sup 86}Rb, {sup 198}Au, these matrix elements do not confirm the independent shell model theory. Other hypotheses are then suggested and discussed. (author) [French] Les experiences de correlation angulaire {beta}{gamma} et l'etude du spectre {beta} conduisant au premier niveau excite du noyau final permettent de determiner les elements de matrices nucleaires caracteristiques de cette transition. Dans les trois cas etudies (transitions une fois interdites): {sup 170}Tm, {sup 86}Rb, {sup 198}Au, ces elements de matrices ne peuvent etre retrouves a l'aide du modele en couches et a particules independantes. D'autres hypotheses sont alors emises et discutees. (auteur)

  11. Contribution to the study of {beta} disintegration and of nuclear structure using experiments on certain {beta}-{gamma} cascades: 198{sub Au}, 86{sub Rb}, 170{sub Tm}; Contribution a l'etude de la desintegration beta et a l'etude de la structure nucleaire a l'aide d'experiences sur certaines cascades beta-gamma: 198{sub Au}, 86{sub Rb}, 170{sub Tm}

    Energy Technology Data Exchange (ETDEWEB)

    Lachkar, J [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes; Paris-11 Univ., fabulte des Sciences 91 - Orsay (France)

    1969-07-01

    {beta}{gamma} directional angular correlations and shapes of inner beta spectra leading to the first excited level of the final nucleus enable one to determine the nuclear matrix elements typical of the {beta} transition. In the three observed first forbidden cases: {sup 170}Tm, {sup 86}Rb, {sup 198}Au, these matrix elements do not confirm the independent shell model theory. Other hypotheses are then suggested and discussed. (author) [French] Les experiences de correlation angulaire {beta}{gamma} et l'etude du spectre {beta} conduisant au premier niveau excite du noyau final permettent de determiner les elements de matrices nucleaires caracteristiques de cette transition. Dans les trois cas etudies (transitions une fois interdites): {sup 170}Tm, {sup 86}Rb, {sup 198}Au, ces elements de matrices ne peuvent etre retrouves a l'aide du modele en couches et a particules independantes. D'autres hypotheses sont alors emises et discutees. (auteur)

  12. Electron excitation cross sections for the 2s(2)2p(3)4S(O) -- 2s(2)2p(3)2D(O) (forbidden) and 4S(O) -- 2s2p(4) 4P (resonance) transitions in O II

    Science.gov (United States)

    Zuo, M.; Smith, Steven J.; Chutjian, A.; Williams, I. D.; Tayal, S. S.; Mclaughlin, Brendan M.

    1995-01-01

    Experimental and theoretical excitation cross sections are reported for the first forbidden transition 4S(O) -- 2S(2)2p(3) 2D(O) (lambda-lambda 3726, 3729) and the first allowed (resonance) transition 4S(O) -- 2s2p(4) 4P(lambda-833) in O II. Use is made of electron energy loss and merged-beams methods. The electron energy range covered is 3.33 (threshold) to 15 eV for the S -- D transition, and 14.9 (threshold) to 40 eV for the S -- P transition. Care was taken to assess and minimize the metastable fraction of the O II beam. An electron mirror was designed and tested to reflect inelastically backscattered electrons into the forward direction to account for the full range of polar scattering angles. Comparisons are made between present experiments and 11-state R-matrix calculations. Calculations are also presented for the 4S(O) -- 2s(2)2p(3)2P(O) (lambda-2470) transition.

  13. Electromagnetically induced nuclear beta decay calculated by a Green's function method

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1984-01-01

    The transition probability for enhancement of forbidden nuclear beta decay by an applied plane-wave electromagnetic field is calculated in a nonrelativistic spinless approximation by a Green's function method. The calculation involves a stationary-phase approximation. The stationary phase points in the presence of an intense field are located in very different positions than they are in the field-free case. In order-of-magnitude terms, the results are completely consistent with an earlier, much more complete wave-function calculation which includes spin and relativistic effects. Both the present Green's function calculation and the earlier wave function calculation give electromagnetic contributions in first-forbidden nuclear beta decay matrix elements which are of order (R 0 /lambda-dash-bar/sub C/) 2 with respect to allowed decays, where R 0 is the nuclear radius and lambda-dash-bar/sub C/ is the electron Compton wavelength

  14. Measurement of the beta-gamma directional correlation of the transition 46Sc→46Ti

    International Nuclear Information System (INIS)

    Krexner, G.

    1978-01-01

    Measuring the forward - backward asymmetry of the direction of gamma quanta with respect to the direction of a preceding beta particle emission is one of the methods which have been developed over the past twenty years to investigate parity admixtures in nuclear states. Both theoretical calculations and experiments using this method yield very small values for the considered effect. Moreover the accuracy is limited for statistical reasons. Hence there exists a fundamental interest in proving the experimental arrangement to be free of systematic errors. The subject of this work is an experiment checking a six - detector apparatus which has been used to investigate the beta - gamma directional correlation in the decay 203 Hg→ 203 Tl. For the control measurement the transition 46 Sc→ 46 Ti was chosen. The asymmetry coefficient should yield zero and thus furnish evidence of the absence of systematic errors. The necessary 46 Sc source had to meet very restricting requirements. The feasibility of various methods for producing radioactive samples was reviewed; finally a specially designed high vacuum evaporation plant was constructed. The concept of this device and the preparation of the source are dealt with in detail. A preliminary result of the control experiment is given. However, at present a definite interpretation of the obtained values is not possible. (author)

  15. Order-disorder transition in conflicting dynamics leading to rank-frequency generalized beta distributions

    Science.gov (United States)

    Alvarez-Martinez, R.; Martinez-Mekler, G.; Cocho, G.

    2011-01-01

    The behavior of rank-ordered distributions of phenomena present in a variety of fields such as biology, sociology, linguistics, finance and geophysics has been a matter of intense research. Often power laws have been encountered; however, their validity tends to hold mainly for an intermediate range of rank values. In a recent publication (Martínez-Mekler et al., 2009 [7]), a generalization of the functional form of the beta distribution has been shown to give excellent fits for many systems of very diverse nature, valid for the whole range of rank values, regardless of whether or not a power law behavior has been previously suggested. Here we give some insight on the significance of the two free parameters which appear as exponents in the functional form, by looking into discrete probabilistic branching processes with conflicting dynamics. We analyze a variety of realizations of these so-called expansion-modification models first introduced by Wentian Li (1989) [10]. We focus our attention on an order-disorder transition we encounter as we vary the modification probability p. We characterize this transition by means of the fitting parameters. Our numerical studies show that one of the fitting exponents is related to the presence of long-range correlations exhibited by power spectrum scale invariance, while the other registers the effect of disordering elements leading to a breakdown of these properties. In the absence of long-range correlations, this parameter is sensitive to the occurrence of unlikely events. We also introduce an approximate calculation scheme that relates this dynamics to multinomial multiplicative processes. A better understanding through these models of the meaning of the generalized beta-fitting exponents may contribute to their potential for identifying and characterizing universality classes.

  16. Forbidden lines of highly ionized ions for localized plasma diagnostics

    International Nuclear Information System (INIS)

    Hinnov, E.; Fonck, R.; Suckewer, S.

    1980-06-01

    Numerous optically forbidden lines resulting from magnetic dipole transitions in low-lying electron configurations of highly ionized Fe, Ti and Cr atoms have been identified in PLT and PDX tokamak discharges, and applied for localized diagnostics in the high-temperature (0.5 to 3.0 keV) interior of these plasmas. The measurements include determination of local ion densities and their variation in time, and of ion motions (ion temperature, plasma rotations) through Doppler effect of the lines. These forbidden lines are particularly appropriate for such measurements because under typical tokamak conditions their emissivities are quite high (10 11 to 10 14 photons/cm 3 -sec), and their relatively long wavelengths allow the use of intricate optical techniques and instrumentation. The spatial location of the emissivity is directly measurable, and tends to occur near radii where the ionization potential of the ion in question is equal to the local electron temperature. In future larger and presumably higher-temperature tokamaks analogous measurements with somewhat heavier atoms, particularly krypton, and perhaps zirconium appear both feasible and desirable

  17. Ionizing Radiation Promotes Migration and Invasion of Cancer Cells Through Transforming Growth Factor-Beta-Mediated Epithelial-Mesenchymal Transition

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Yongchun [Department of Radiation Oncology, Xijing Hospital Fourth Military Medical University, Xi' an (China); Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China); Liu Junye; Li Jing; Zhang Jie [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China); Xu Yuqiao [Department of Pathology, Xijing Hospital Fourth Military Medical University, Xi' an (China); Zhang Huawei; Qiu Lianbo; Ding Guirong [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China); Su Xiaoming [Department of Radiation Oncology, 306th Hospital of PLA, Beijing (China); Mei Shi [Department of Radiation Oncology, Xijing Hospital Fourth Military Medical University, Xi' an (China); Guo Guozhen, E-mail: guozhenguo@hotmail.com [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China)

    2011-12-01

    Purpose: To examine whether ionizing radiation enhances the migratory and invasive abilities of cancer cells through transforming growth factor (TGF-{beta})-mediated epithelial-mesenchymal transition (EMT). Methods and Materials: Six cancer cell lines originating from different human organs were irradiated by {sup 60}Co {gamma}-ray at a total dose of 2 Gy, and the changes associated with EMT, including morphology, EMT markers, migration and invasion, were observed by microscope, Western blot, immunofluorescence, scratch assay, and transwell chamber assay, respectively. Then the protein levels of TGF-{beta} in these cancer cells were detected by enzyme-linked immunosorbent assay, and the role of TGF-{beta} signaling pathway in the effect of ionizing radiation on EMT was investigate by using the specific inhibitor SB431542. Results: After irradiation with {gamma}-ray at a total dose of 2 Gy, cancer cells presented the mesenchymal phenotype, and compared with the sham-irradiation group the expression of epithelial markers was decreased and of mesenchymal markers was increased, the migratory and invasive capabilities were strengthened, and the protein levels of TGF-{beta} were enhanced. Furthermore, events associated with EMT induced by IR in A549 could be reversed through inhibition of TGF-{beta} signaling. Conclusions: These results suggest that EMT mediated by TGF-{beta} plays a critical role in IR-induced enhancing of migratory and invasive capabilities in cancer cells.

  18. Research of TGF-beta1 Inducing Lung Adencarcinoma PC9 Cells to Mesenchymal Cells Transition

    Directory of Open Access Journals (Sweden)

    Xiaofeng CHEN

    2010-01-01

    Full Text Available Background and objective It has been proven that epithelial-mesenchymal transition (EMT not only correlated with embryonic development but also could promote tumor invasion and metastasis. Transforming growth factor beta-1 (TGF-β1 has been identified as the main inducer of tumor EMT. The aim of this study was to investigate the effects of TGF-β1 on EMT and PI3K/AKT signaling pathway in lung adencarcinoma PC9 cells. Methods Cultured PC9 cells were treated with different concentrations of TGF-β1 for 48 h. The morphological changes were observed under phase-contrast microscopy; EMT relative marker protein changes were assessed by Western blot and immunoflurescence staining. In addition, the expression of AKT and P-AKT were also measured by Western blot. Results The data showed that TGF-β1 could induce PC9 morphological alteration from epithelial to mesenchymal and upregulate the expression of mesenchymal maker protein Fibronectin. Obviously, the expression of P-AKT was downregulated by TGF-β1 treatment for 48 h. Conclusion TGF-β1 might induce EMT of PC9 cells , accompanied by the changes of PI3K/AKT signaling pathway.

  19. Alpha5beta1 integrin-fibronectin interactions specify liquid to solid phase transition of 3D cellular aggregates.

    Directory of Open Access Journals (Sweden)

    Carlos E Caicedo-Carvajal

    2010-07-01

    Full Text Available Tissue organization during embryonic development and wound healing depends on the ability of cells on the one hand to exchange adhesive bonds during active rearrangement and on the other to become fixed in place as tissue homeostasis is reached. Cells achieve these contradictory tasks by regulating either cell-cell adhesive bonds, mediated by cadherins, or cell-extracellular matrix (ECM connections, regulated by integrins. Integrin alpha5beta1 and soluble fibronectin (sFN are key players in cell-ECM force generation and in ECM polymerization. Here, we explore the interplay between integrin alpha5beta1 and sFN and its influence on tissue mechanical properties and cell sorting behavior.We generated a series of cell lines varying in alpha5beta1 receptor density. We then systematically explored the effects of different sFN concentrations on aggregate biomechanical properties using tissue surface tensiometry. We found previously unreported complex behaviors including the observation that interactions between fibronectin and integrin alpha5beta1 generates biphasic tissue cohesion profiles. Specifically, we show that at constant sFn concentration, aggregate cohesion increases linearly as alpha5beta1 receptor density is increased from low to moderate levels, producing a transition from viscoelastic-liquid to pseudo viscoelastic-solid behavior. However, further increase in receptor density causes an abrupt drop in tissue cohesion and a transition back to viscoelastic-liquid properties. We propose that this may be due to depletion of sFn below a critical value in the aggregate microenvironment at high alpha5beta1 levels. We also show that differential expression of alpha5beta1 integrin can promote phase-separation between cells.The interplay between alpha5-integrin and sFn contributes significantly to tissue cohesion and, depending on their level of expression, can mediate a shift from liquid to elastic behavior. This interplay represents a tunable level

  20. Beta decay and muon capture rates in a self-consistent relativistic framework

    Energy Technology Data Exchange (ETDEWEB)

    Marketin, Tomislav; Paar, Nils; Niksic, Tamara; Vretenar, Dario [Physics Department, Faculty of Science, University of Zagreb (Croatia); Ring, Peter [Physik-Department, Technische Universitaet Muenchen, D-85748 Muenchen (Germany)

    2009-07-01

    A fully consistent calculation of muon capture and beta decay rates is presented, based on a microscopic theoretical framework describing the semileptonic weak interaction processes. Nuclear ground state is determined using the Relativistic Hartree-Bogolyubov (RHB) model with density dependent meson-nucleon coupling constants, and transition rates are calculated via proton-neutron relativistic quasiparticle RPA using the same interaction as in the RHB equations. Muon capture rates are calculated for a wide range of nuclei along the valley of stability, from {sup 12}C to {sup 244}Pu, with accuracy of approximately 30%, using the interaction DD-ME2. Previous studies of beta decay rates have only taken into account Gamow-Teller transitions. We extend this approach by including forbidden transitions and systematically study their contribution to decay rates of exotic nuclei along the r-process path, which are important for constraining the conditions in which nucleosynthesis takes place.

  1. Beta decay of the fission product 125Sb and a new complete evaluation of absolute gamma ray transition intensities

    Science.gov (United States)

    Rajput, M. U.; Ali, N.; Hussain, S.; Mujahid, S. A.; MacMahon, D.

    2012-04-01

    The radionuclide 125Sb is a long-lived fission product, which decays to 125Te by negative beta emission with a half-life of 1008 day. The beta decay is followed by the emission of several gamma radiations, ranging from low to medium energy, that can suitably be used for high-resolution detector calibrations, decay heat calculations and in many other applications. In this work, the beta decay of 125Sb has been studied in detail. The complete published experimental data of relative gamma ray intensities in the beta decay of the radionuclide 125Sb has been compiled. The consistency analysis was performed and discrepancies found at several gamma ray energies. Evaluation of the discrepant data was carried out using Normalized Residual and RAJEVAL methods. The decay scheme balance was carried out using beta branching ratios, internal conversion coefficients, populating and depopulating gamma transitions to 125Te levels. The work has resulted in the consistent conversion factor equal to 29.59(13) %, and determined a new evaluated set of the absolute gamma ray emission probabilities. The work has also shown 22.99% of the delayed intensity fraction as outgoing from the 58 d isomeric 144 keV energy level and 77.01% of the prompt intensity fraction reaching to the ground state from the other excited states. The results are discussed and compared with previous evaluations. The present work includes additional experimental data sets which were not included in the previous evaluations. A new set of recommended relative and absolute gamma ray emission probabilities is presented.

  2. Beta decay of the fission product 125Sb and a new complete evaluation of absolute gamma ray transition intensities

    International Nuclear Information System (INIS)

    Rajput, M.U.; Ali, N.; Hussain, S.; Mujahid, S.A.; MacMahon, D.

    2012-01-01

    The radionuclide 125 Sb is a long-lived fission product, which decays to 125 Te by negative beta emission with a half-life of 1008 day. The beta decay is followed by the emission of several gamma radiations, ranging from low to medium energy, that can suitably be used for high-resolution detector calibrations, decay heat calculations and in many other applications. In this work, the beta decay of 125 Sb has been studied in detail. The complete published experimental data of relative gamma ray intensities in the beta decay of the radionuclide 125 Sb has been compiled. The consistency analysis was performed and discrepancies found at several gamma ray energies. Evaluation of the discrepant data was carried out using Normalized Residual and RAJEVAL methods. The decay scheme balance was carried out using beta branching ratios, internal conversion coefficients, populating and depopulating gamma transitions to 125 Te levels. The work has resulted in the consistent conversion factor equal to 29.59(13) %, and determined a new evaluated set of the absolute gamma ray emission probabilities. The work has also shown 22.99% of the delayed intensity fraction as outgoing from the 58 d isomeric 144 keV energy level and 77.01% of the prompt intensity fraction reaching to the ground state from the other excited states. The results are discussed and compared with previous evaluations. The present work includes additional experimental data sets which were not included in the previous evaluations. A new set of recommended relative and absolute gamma ray emission probabilities is presented.

  3. Theoretical interpretation of forbidden transitions in solid hydrogen

    International Nuclear Information System (INIS)

    Balasubramanian, T.K.

    1997-01-01

    In particular, solid hydrogen as the archetypical molecular quantum solid, seems to present endless opportunities and challenges to experimentalists and theorists alike. This chapter briefly reviews certain aspects of infrared spectrum of solid hydrogen and outline how the various spectral features may be interpreted

  4. Beta-decay rate and beta-delayed neutron emission probability of improved gross theory

    Science.gov (United States)

    Koura, Hiroyuki

    2014-09-01

    A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for unmeasured nuclei are adopted from the KTUY nuclear mass formula, which is based on the spherical-basis method. Considering the properties of the integrated Fermi function, we can roughly categorized energy region of excited-state of a daughter nucleus into three regions: a highly-excited energy region, which fully affect a delayed neutron probability, a middle energy region, which is estimated to contribute the decay heat, and a region neighboring the ground-state, which determines the beta-decay rate. Some results will be given in the presentation. A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for

  5. An unforgettable apple: memory and attention for forbidden objects.

    Science.gov (United States)

    Truong, Grace; Turk, David J; Handy, Todd C

    2013-12-01

    Are we humans drawn to the forbidden? From jumbo-sized soft drinks to illicit substances, the influence of prohibited ownership on subsequent demand has made this question a pressing one. We know that objects that we ourselves own have a heightened psychological saliency, relative to comparable objects that are owned by others, but do these kinds of effects extend from self-owned to "forbidden" objects? To address this question, we developed a modified version of the Turk shopping paradigm in which "purchased" items were assigned to various recipients. Participants sorted everyday objects labeled as "self-owned", "other-owned," and either "forbidden to oneself" (Experiment 1) or "forbidden to everyone" (Experiment 2). Subsequent surprise recognition memory tests revealed that forbidden objects with high (Experiment 1) but not with low (Experiment 2) self-relevance were recognized as well as were self-owned objects, and better than other-owned objects. In a third and final experiment, we used event-related potentials (ERPs) to determine whether self-owned and self-forbidden objects, which showed a common memory advantage, are in fact treated the same at a neurocognitive-affective level. We found that both object types were associated with enhanced cognitive analysis, relative to other-owned objects, as measured by the P300 ERP component. However, we also found that self-forbidden objects uniquely triggered an enhanced response preceding the P300, in an ERP component (the N2) that is sensitive to more rapid, affect-related processing. Our findings thus suggest that, whereas self-forbidden objects share a common cognitive signature with self-owned objects, they are unique in being identified more quickly at a neurocognitive level.

  6. Liver cancer-derived hepatitis C virus core proteins shift TGF-beta responses from tumor suppression to epithelial-mesenchymal transition.

    Directory of Open Access Journals (Sweden)

    Serena Battaglia

    Full Text Available BACKGROUND: Chronic hepatitis C virus (HCV infection and associated liver cirrhosis represent a major risk factor for hepatocellular carcinoma (HCC development. TGF-beta is an important driver of liver fibrogenesis and cancer; however, its actual impact in human cancer progression is still poorly known. The aim of this study was to investigate the role of HCC-derived HCV core natural variants on cancer progression through their impact on TGF-beta signaling. PRINCIPAL FINDINGS: We provide evidence that HCC-derived core protein expression in primary human or mouse hepatocyte alleviates TGF-beta responses in terms or growth inhibition or apoptosis. Instead, in these hepatocytes TGF-beta was still able to induce an epithelial to mesenchymal transition (EMT, a process that contributes to the promotion of cell invasion and metastasis. Moreover, we demonstrate that different thresholds of Smad3 activation dictate the TGF-beta responses in hepatic cells and that HCV core protein, by decreasing Smad3 activation, may switch TGF-beta growth inhibitory effects to tumor promoting responses. CONCLUSION/SIGNIFICANCE: Our data illustrate the capacity of hepatocytes to develop EMT and plasticity under TGF-beta, emphasize the role of HCV core protein in the dynamic of these effects and provide evidence for a paradigm whereby a viral protein implicated in oncogenesis is capable to shift TGF-beta responses from cytostatic effects to EMT development.

  7. Internal bremsstrahlung accompanying non-unique second-forbidden β-decay of 36Cl

    International Nuclear Information System (INIS)

    Basha, A.M.; Khalil, E.I.; Hussein, M.; Ragab, H.S.; El-Konsol, S.

    1991-01-01

    The inner Bremsstrahlung spectrum (I.B.) associated with the non-unique second forbidden β-transition of 36 Cl was measured using a single channel NaI (Tl) scintillation spectrometer. After making all the necessary corrections, the experimental results were compared with the corresponding theoretical distributions due to the KUB, Lewis and Ford, Nilsson, Ford and Martin and Chang and Falkoff. Also a comparison with those calculated according to Nilsson theory after applying the shape correction factor (M. KUB) was done. The measured spectrum is found to show fairly good agreement with M. KUB theory and is found to deviate thereafter from all five theories. (orig.)

  8. Relativistic pn-QRPA to the double beta decay

    International Nuclear Information System (INIS)

    Conti, Claudio de; Krmpotic, F.; Carlson, Brett Vern

    2010-01-01

    Full text: In nature there are about 50 nuclear systems where the single beta-decay is energetically forbidden, and double- beta decay turns out to be only possible mode of disintegration. It is the nuclear pairing force which causes such an 'anomaly', by making the mass of the odd-odd isobar, (N - 1;Z + 1), to be greater than the masses of its even-even neighbors, (N;Z) and (N - 2;Z +2). The modes by which the double-beta decay can take place are connected with the neutrino and antineutrino distinction. In case the lepton number is strictly conserved the neutrino is a Dirac fermion and the two-neutrino mode is the only possible mode of disintegration. On the other hand, if this conservation is violated, the neutrino is a Majorana particle and neutrinoless double-beta decay also can occur. Both two-neutrino and neutrinoless double-beta decay processes have attracted much attention, because a comparison between experiment and theory for the first, provides a measure of confidence one may have in the nuclear wave function employed for extracting the unknown parameters from neutrinoless lifetime measurements. The proton-neutron (pn) quasiparticle random phase approximation (QRPA) has turned out be the most simple model for calculating the nuclear wave function involved in the double-beta decay transitions. In this work the transition matrix elements for 0 + -> 0 + double-beta decay are calculated for 48 Ca, 76 Ge, 82 Se, 100 Mo, 128 Te and 130 Te nuclei, using a relativistic pn-QRPA based on Hartree-Bogoliubov approximation to the single-particle motion. (author)

  9. Relativistic pn-QRPA to the double beta decay

    International Nuclear Information System (INIS)

    Conti, Claudio de; Krmpotic, Francisco; Carlson, Brett Vern

    2011-01-01

    Full text: In nature there are about 50 nuclear systems where the single beta-decay is energetically forbidden, and double-beta decay turns out to be only possible mode of disintegration. It is the nuclear pairing force which causes such an 'anomaly', by making the mass of the odd-odd isobar, (N - 1;Z + 1), to be greater than the masses of its even-even neighbors, (N;Z) and (N - 2;Z +2). The modes by which the double-beta decay can take place are connected with the neutrino and antineutrino distinction. In case the lepton number is strictly conserved the neutrino is a Dirac fermion and the two-neutrino mode is the only possible mode of disintegration. On the other hand, if this conservation is violated, the neutrino is a Majorana particle and neutrinoless double-beta decay also can occur. Both two-neutrino and neutrinoless double-beta decay processes have attracted much attention, because a comparison between experiment and theory for the first, provides a measure of confidence one may have in the nuclear wave function employed for extracting the unknown parameters from neutrinoless lifetime measurements. The proton-neutron (pn) quasiparticle random phase approximation (QRPA) has turned out be the most simple model for calculating the nuclear wave function involved in the double-beta decay transitions. In this work the transition matrix elements for 0 + → 0 + double-beta decay are calculated for 48 Ca, 76 Ge, 82 Se, 100 Mo, 128 Te and 130 Te nuclei, using a relativistic pn-QRPA based on Hartree-Bogoliubov approximation to the single-particle motion. (author)

  10. Measurement of the internal bremsstrahlung spectrum of a 89Sr beta emitter in the 1–100 keV photon energy regime

    International Nuclear Information System (INIS)

    Singh, Amrit; Dhaliwal, A.S.

    2015-01-01

    The internal bremsstrahlung (IB) spectrum of 89 Sr, which is a unique first forbidden beta emitter, is studied in the 1–100 keV photon energy regime. The IB spectrum is experimentally measured using a Si(Li) detector, which is efficient in this photon energy regime, and is compared with the IB distributions that are predicted by the Knipp, Uhlenbeck and Bloch (KUB), Nilsson, and Lewis and Ford theories. In the soft energy regime up to 15 keV, the measured results are in agreement with all the aforementioned theories. However, from 16–30 keV, the experimental results are in agreement with the Lewis and Ford theory, which applies to forbidden transitions, and at higher photon energies, the Nilsson theory best describes the measured results. The differences among the different theories also increase with the photon energy. The effect of the electrostatic Coulomb field on the IB process for beta emitters with different end-point energies is investigated by comparing the ratio of the IB probabilities predicted using the KUB and Nilsson theories for 35 S and 89 Sr, i.e., soft and hard beta emitters, respectively. The Coulomb effect is shown to be significant in the high photon energy regime and for beta emitters with low end-point energies. - Highlights: • Internal bremsstrahlung spectrum of 89 Sr, a unique first forbidden beta emitter, is studied. • The measurements are taken in the photon energy regions of 1–100 keV with Si(Li) detector. • The measured results are deviating from Lewis and Ford theory and are close to the Nilsson theory. • The effect of Coulomb field on the IB process for different end point energy sources is investigated. • Effect of Coulomb field is more for low energy beta emitter towards the high energy end

  11. Inhibition of transforming growth factor-beta1-induced signaling and epithelial-to-mesenchymal transition by the Smad-binding peptide aptamer Trx-SARA.

    Science.gov (United States)

    Zhao, Bryan M; Hoffmann, F Michael

    2006-09-01

    Overexpression of the inhibitory Smad, Smad7, is used frequently to implicate the Smad pathway in cellular responses to transforming growth factor beta (TGF-beta) signaling; however, Smad7 regulates several other proteins, including Cdc42, p38MAPK, and beta-catenin. We report an alternative approach for more specifically disrupting Smad-dependent signaling using a peptide aptamer, Trx-SARA, which comprises a rigid scaffold, the Escherichia coli thioredoxin A protein (Trx), displaying a constrained 56-amino acid Smad-binding motif from the Smad anchor for receptor activation (SARA) protein. Trx-SARA bound specifically to Smad2 and Smad3 and inhibited both TGF-beta-induced reporter gene expression and epithelial-to-mesenchymal transition in NMuMG murine mammary epithelial cells. In contrast to Smad7, Trx-SARA had no effect on the Smad2 or 3 phosphorylation levels induced by TGF-beta1. Trx-SARA was primarily localized to the nucleus and perturbed the normal cytoplasmic localization of Smad2 and 3 to a nuclear localization in the absence of TGF-beta1, consistent with reduced Smad nuclear export. The key mode of action of Trx-SARA was to reduce the level of Smad2 and Smad3 in complex with Smad4 after TGF-beta1 stimulation, a mechanism of action consistent with the preferential binding of SARA to monomeric Smad protein and Trx-SARA-mediated disruption of active Smad complexes.

  12. Fluid sensitive nanoscale switching with quantum levitation controlled by $\\alpha$-Sn/$\\beta$-Sn phase transition

    OpenAIRE

    Boström, Mathias; Dou, Maofeng; Malyi, Oleksandr I.; Parashar, Prachi; Parsons, Drew F.; Brevik, Iver; Persson, Clas

    2018-01-01

    We analyze the Lifshitz pressure between silica and tin separated by a liquid mixture of bromobenzene and chlorobenzene. We show that the phase transition from semimetallic α−Sn to metallic β−Sn can switch Lifshitz forces from repulsive to attractive. This effect is caused by the difference in dielectric functions of α−Sn and β−Sn, giving both attractive and repulsive contributions to the total Lifshitz pressure in different frequency regions controlled by the composition of the intervening l...

  13. In-situ observation of the alpha/beta cristobalite transition using high voltage electron microscopy

    International Nuclear Information System (INIS)

    Meike, A.; Glassley, W.

    1989-10-01

    A high temperature water vapor phase is expected to persist in the vicinity of high level radioactive waste packages for several hundreds of years. The authors have begun an investigation of the structural and chemical effects of water on cristobalite because of its abundance in the near field environment. A high voltage transmission electron microscope (HVEM) investigation of bulk synthesized α-cristobalite to be used in single phase dissolution and precipitation kinetics experiments revealed the presence β-cristobalite, quartz and amorphous silica, in addition to α-cristobalite. Consequently, this apparent metastable persistence of β-cristobalite and amorphous silica during the synthesis of α-cristobalite was investigated using a heating stage and an environmental cell installed in the HVEM that allowed the introduction of either dry CO 2 or a CO 2 + H 2 O vapor. Preliminary electron diffraction evidence suggests that the presence of water vapor affected the α-β transition temperature. Water vapor may also be responsible for the development of an amorphous silica phase at the transition that may persist over an interval of several tens of degrees. The amorphous phase was not documented during the dry heating experiments. 20 refs., 7 figs., 5 tabs

  14. In-situ observation of the alpha/beta cristobalite transition using high voltage electron microscopy

    International Nuclear Information System (INIS)

    Meike, A.; Glassley, W.E.

    1990-01-01

    A high temperature water vapor phase is expected to persist in the vicinity of high level radioactive waste packages for several hundreds of years. The authors have begun an investigation of the structural and chemical effects of water on cristobalite because of its abundance in the near field environment. A high voltage transmission electron microscope (HVEM) investigation of bulk synthesized α-cristobalite to be used in single phase dissolution and precipitation kinetics experiments revealed the presence β-cristobalite, quartz and amorphous silica, in addition to α-cristobalite. Consequently, this apparent metastable persistence of β-cristobalite and amorphous silica during the synthesis of α-cristobalite was investigated using a heating stage and an environmental cell installed in the HVEM that allowed the introduction of either dry CO 2 or a CO 2 + H 2 O vapor. Preliminary electron diffraction evidence suggests that the presence of water vapor affected the α-β transition temperature. Water vapor may also be responsible for the development of an amorphous silica phase at the transition that may persist over an interval of several tens of degrees. The amorphous phase was not documented during the dry heating experiments

  15. 49 CFR 396.7 - Unsafe operations forbidden.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS INSPECTION, REPAIR, AND MAINTENANCE § 396.7 Unsafe operations forbidden. (a) General. A motor vehicle shall not be operated in such a condition as to likely cause an accident or a breakdown of the vehicle. (b) Exemption. Any motor vehicle...

  16. E-cigarettes forbidden in offices and closed areas

    CERN Document Server

    2013-01-01

    Be reminded that all people on the CERN site must comply with the following notice from the Medical Service: “In the same manner as for ordinary cigarettes, the use of e-cigarettes is forbidden in all offices and closed areas.” If you have any question, please write to medical.service@cern.ch HSE Unit/ GS-ME Department

  17. Forbidden coupling and inhibited decay: a study of disconnection

    International Nuclear Information System (INIS)

    Bolzan, J.F.; Palmer, W.F.; Pinsky, S.S.

    1975-01-01

    An attempt is made to correlate deviation from ideal mixing mass formula, high energy scattering behavior, and violation of the Okubo-Zweig-Iizuka rule. Pole or cut nature of the intermediary is discussed. Timelike and spacelike forbidden communications are compared. Off-shell effects are examined. Some problems for phenomenology are revealed

  18. Tasting the Forbidden Fruit: The Social Context of Debut Sexual ...

    African Journals Online (AJOL)

    Tasting the Forbidden Fruit: The Social Context of Debut Sexual Encounters Among Young Persons in a Rural Nigerian Community. ... Alternatively, you can download the PDF file directly to your computer, from where it can be opened using a PDF reader. To download the PDF, click the Download link above.

  19. Majorana neutrino masses and the neutrinoless double-beta decay

    International Nuclear Information System (INIS)

    Faessler, A.

    2006-01-01

    Neutrinoless double-beta decay is forbidden in the Standard Model of electroweak and strong interaction but allowed in most Grand Unified Theories (GUTs). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass is neutrinoless double-beta decay allowed. Apart from one claim that the neutrinoless double-beta decay in 76 Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow one to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUTs and the minimal R-parity-violating supersymmetric model. One further can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUTs. For that, one has to assume that the specific mechanism is the leading one for neutrinoless double-beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present work, one discusses the accuracy of the present status of calculating of the nuclear matrix elements and the corresponding limits of GUTs and supersymmetric parameters

  20. M1 and E2 transitions in the ground-state configuration of atomic ...

    Indian Academy of Sciences (India)

    have calculated the forbidden transition (M1 and E2) parameters such as transition energies, log- arithmic weighted ... Keywords. Forbidden transitions; transition energies; logarithmic weighted oscillator strengths; .... optimizing the energy function based on the non-relativistic Hamiltonian of an atom,. HNR = N. ∑ j=1. (12∇ ...

  1. Beta decay rates of neutron-rich nuclei

    Science.gov (United States)

    Marketin, Tomislav; Huther, Lutz; Petković, Jelena; Paar, Nils; Martínez-Pinedo, Gabriel

    2016-06-01

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei. Aside from the astrophysical applications, the results of this calculation can also be employed in the modeling of the electron and antineutrino spectra from nuclear reactors.

  2. Beta decay rates of neutron-rich nuclei

    International Nuclear Information System (INIS)

    Marketin, Tomislav; Petković, Jelena; Paar, Nils; Huther, Lutz; Martínez-Pinedo, Gabriel

    2016-01-01

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei. Aside from the astrophysical applications, the results of this calculation can also be employed in the modeling of the electron and antineutrino spectra from nuclear reactors.

  3. Beta decay rates of neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Marketin, Tomislav, E-mail: marketin@phy.hr; Petković, Jelena; Paar, Nils [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Huther, Lutz [Institut für Kernphysik (Theoriezentrum), Technische Universität Darmstadt, 64289 Darmstadt (Germany); Martínez-Pinedo, Gabriel [Institut für Kernphysik (Theoriezentrum), Technische Universität Darmstadt, 64289 Darmstadt (Germany); GSI Helmholtzzentrum für Schwerioneneforschung, Planckstraße 1, 64291 Darmstadt (Germany)

    2016-06-21

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei. Aside from the astrophysical applications, the results of this calculation can also be employed in the modeling of the electron and antineutrino spectra from nuclear reactors.

  4. Beta decay rates of neutron-rich nuclei

    International Nuclear Information System (INIS)

    Marketin, Tomislav; Huther, Lutz; Martínez-Pinedo, Gabriel

    2015-01-01

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. Currently, a single large-scale calculation is available based on a QRPA calculation with a schematic interaction on top of the Finite Range Droplet Model. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei

  5. Beta decay rates of neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Marketin, Tomislav, E-mail: marketin@phy.hr [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Huther, Lutz [Institut für Kernphysik (Theoriezentrum), Technische Universität Darmstadt, 64289 Darmstadt (Germany); Martínez-Pinedo, Gabriel [Institut für Kernphysik (Theoriezentrum), Technische Universität Darmstadt, 64289 Darmstadt (Germany); GSI Helmholtzzentrum für Schwerioneneforschung, Planckstraße 1, 64291 Darmstadt (Germany)

    2015-10-15

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. Currently, a single large-scale calculation is available based on a QRPA calculation with a schematic interaction on top of the Finite Range Droplet Model. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei.

  6. On the theory of beta-radioactivity IV : The polarization of beta-rays emitted by aligned nuclei in allowed transitions

    NARCIS (Netherlands)

    Tolhoek, H.A.; Groot, S.R. de

    The consequences of alignment of nuclei, which show allowed ß-transitions, are investigated. A general formula is derived for the transition probability of an allowed β-transition, in which the direction of emission of electron and neutrino, the polarization of the electron and the orientation of

  7. Full Polarization Analysis of Resonant Superlattice and Forbidden x-ray Reflections in Magnetite

    International Nuclear Information System (INIS)

    Wilkins, S.B.; Bland, S.R.; Detlefs, B.; Beale, T.A.W.; Mazzoli, C.; Joly, Y.; Hatton, P.D.; Lorenzo, J.E.; Brabers, V.A.M.

    2009-01-01

    Despite being one of the oldest known magnetic materials, and the classic mixed valence compound, thought to be charge ordered, the structure of magnetite below the Verwey transition is complex and the presence and role of charge order is still being debated. Here, we present resonant x-ray diffraction data at the iron K-edge on forbidden (0, 0, 2n+1) C and superlattice (0, 0, 2n+1/2)C reflections. Full linear polarization analysis of the incident and scattered light was conducted in order to explore the origins of the reflections. Through simulation of the resonant spectra we have confirmed that a degree of charge ordering takes place, while the anisotropic tensor of susceptibility scattering is responsible for the superlattice reflections below the Verwey transition. We also report the surprising result of the conversion of a significant proportion of the scattered light from linear to nonlinear polarization.

  8. Inner Bremsstrahlung accompanying the non-unique first forbidden β-decay of 141Ce

    International Nuclear Information System (INIS)

    Khalil, E.I.

    1993-01-01

    The inner Bremsstrahlung (I.B.) spectrum accompanying the β-decay of 141 Ce (non-unique first forbidden β-transition) was measured using a single channel scintillation spectrometer. The measured I.B. was analyzed by the variable width peeling-off method. This analyzed and corrected I.B. was compared with those calculated according to the original theories of Knipp and Uhlenbeck as well as of Bloch (KUB), the coulomb corrected theories of Lewis and Ford and of Nilsson, and according to detour-transition calculations of the Ford and Martin theory. Ths shape correction factor suggested by Konopinski and Uhlenbeck on the Fermi β-decay theory was applied to the calculated I.B. based on Nilsson's theory (modified KUB theory). The experimental results are in better agreement with the modified KUB theory than the other theories. (orig.)

  9. First observation of the strongly forbidden transition {sup 1}S{sub 0} - {sup 3}P{sub 0} in Strontium, for an atomic clock with trapped atoms; Premiere observation de la transition fortement interdite {sup 1}S{sub 0} - {sup 3}P{sub 0} du strontium, pour une horloge optique a atomes pieges

    Energy Technology Data Exchange (ETDEWEB)

    Courtillot, I

    2003-11-01

    This thesis reports the first results towards the realization of an optical clock using trapped strontium atoms. This set up would combine advantages of the different approaches commonly used to develop an atomic frequency standard. The first part describes the cold atoms source which is implemented. A magneto-optical trap operating on the {sup 1}S{sub 0}-{sup 1}P{sub 1} transition at 461 nm is loaded from an atomic beam decelerated by a Zeeman slower. The 461 nm laser is obtained by sum-frequency mixing in a potassium titanyl phosphate (KTP) crystal. The second part is devoted to the different stages developed to achieve the direct excitation of the {sup 1}S{sub 0}-{sup 3}P{sub 0} clock transition in {sup 87}Sr. This line has a theoretical natural width of 10{sup -3} Hz. Before this detection, we obtained an estimate of the resonance frequency by measuring absolute frequencies of several allowed optical transitions. (author)

  10. Investigation of the parity forbidden alpha decay of 20Ne

    International Nuclear Information System (INIS)

    Disque, M.

    1978-01-01

    In this thesis the alpha decay of excited states in 20 Ne is investigated. The excited neon states are formed by proton bombardment of 19 F at proton energie of 340 and 670 kev. The ratio E of the parity forbidden alpha decays leading to the ground state of 160 to the allowed decays is determined. The results are E = 7.4 x 10 -5 resonance at 340 kev, E = 4.2 x 10 -3 resonance at 670 kev. (FKS)

  11. Permitted and forbidden sets in symmetric threshold-linear networks.

    Science.gov (United States)

    Hahnloser, Richard H R; Seung, H Sebastian; Slotine, Jean-Jacques

    2003-03-01

    The richness and complexity of recurrent cortical circuits is an inexhaustible source of inspiration for thinking about high-level biological computation. In past theoretical studies, constraints on the synaptic connection patterns of threshold-linear networks were found that guaranteed bounded network dynamics, convergence to attractive fixed points, and multistability, all fundamental aspects of cortical information processing. However, these conditions were only sufficient, and it remained unclear which were the minimal (necessary) conditions for convergence and multistability. We show that symmetric threshold-linear networks converge to a set of attractive fixed points if and only if the network matrix is copositive. Furthermore, the set of attractive fixed points is nonconnected (the network is multiattractive) if and only if the network matrix is not positive semidefinite. There are permitted sets of neurons that can be coactive at a stable steady state and forbidden sets that cannot. Permitted sets are clustered in the sense that subsets of permitted sets are permitted and supersets of forbidden sets are forbidden. By viewing permitted sets as memories stored in the synaptic connections, we provide a formulation of long-term memory that is more general than the traditional perspective of fixed-point attractor networks. There is a close correspondence between threshold-linear networks and networks defined by the generalized Lotka-Volterra equations.

  12. GSTA3 Attenuates Renal Interstitial Fibrosis by Inhibiting TGF-Beta-Induced Tubular Epithelial-Mesenchymal Transition and Fibronectin Expression.

    Directory of Open Access Journals (Sweden)

    Yun Xiao

    Full Text Available Tubular epithelial-mesenchymal transition (EMT has been widely accepted as the underlying mechanisms of renal interstitial fibrosis (RIF. The production of reactive oxygen species (ROS plays a vital role in tubular EMT process. The purpose of this study was to investigate the involved molecular mechanisms in TGF-beta-induced EMT and identify the potential role of glutathione S-transferase alpha 3 (GSTA3 in this process. The iTRAQ screening was performed to identify protein alterations of the rats underwent unilateral-ureteral obstruction (UUO. Protein expression of GSTA3 in patients with obstructive nephropathy and UUO rats was detected by immunohistochemistry. Protein and mRNA expression of GSTA3 in UUO rats and NRK-52E cells were determined by Western blot and RT-PCR. siRNA and overexpression plasmid were transfected specifically to assess the role of GSTA3 in RIF. The generation of ROS was measured by dichlorofluorescein fluorescence analysis. GSTA3 protein and mRNA expression was significantly reduced in UUO rats. Immunohistochemical analysis revealed that GSTA3 expression was reduced in renal cortex in UUO rats and patients with obstructive nephropathy. Treating with TGF-β1 down-regulated GSTA3 expression in NRK-52E cells, which have been found to be correlated with the decreased expression in E-cadherin and megalin and increased expression in α-smooth muscle actin. Furthermore, knocking down GSTA3 in NRK-52 cells led to increased production of ROS and tubular EMT, whereas overexpressing GSTA3 ameliorated ROS production and prevented the occurrence of tubular EMT. GSTA3 plays a protective role against tubular EMT in renal fibrosis, suggesting GSTA3 is a potential therapeutic target for RIF.

  13. Measurements of visible forbidden lines and ion distributions of tungsten highly charged ions at the LHD

    International Nuclear Information System (INIS)

    Kato, D.; Sakaue, H.A.; Murakami, I.; Goto, M.; Morita, S.; Nakamura, N.; Koike, F.; Sasaki, Akira; Ding, X.-B.; Dong, C.-Z.

    2013-01-01

    Visible lines, which are presumably associated with forbidden lines from tungsten highly charged ions, were clearly observed in a spectrum of 370 - 410 nm recorded shortly after a tungsten pellet injection at the LHD. One of the measured lines has been assigned to a magnetic-dipole (M1) line of the ground-term fine-structure transition of W 26+ . Photon emission was observed at 44 lines of sight divided along the vertical direction of a horizontally elongated poloidal cross section of the LHD plasma. The line-integrated intensity of the lines along each line of sight indicates peaked profiles near the plasma center, while visible line emissions of neutral hydrogen and helium recoded in the same sampling time have a maximum located in the peripheral region of the poloidal cross section. (author)

  14. Revisiting the `forbidden' region: AGN radiative feedback with radiation trapping

    Science.gov (United States)

    Ishibashi, W.; Fabian, A. C.; Ricci, C.; Celotti, A.

    2018-06-01

    Active galactic nucleus (AGN) feedback, driven by radiation pressure on dust, is an important mechanism for efficiently coupling the accreting black hole to the surrounding environment. Recent observations confirm that X-ray selected AGN samples respect the effective Eddington limit for dusty gas in the plane defined by the observed column density versus the Eddington ratio, the so-called NH - λ plane. A `forbidden' region occurs in this plane, where obscuring clouds cannot be long-lived, due to the action of radiation pressure on dust. Here we compute the effective Eddington limit by explicitly taking into account the trapping of reprocessed radiation (which has been neglected in previous works), and investigate its impact on the NH - λ plane. We show that the inclusion of radiation trapping leads to an enhanced forbidden region, such that even Compton-thick material can potentially be disrupted by sub-Eddington luminosities. We compare our model results to the most complete sample of local AGNs with measured X-ray properties, and find good agreement. Considering the anisotropic emission from the accretion disc, we also expect the development of dusty outflows along the polar axis, which may naturally account for the polar dust emission recently detected in several AGNs from mid-infrared observations. Radiative feedback thus appears to be the key mechanism regulating the obscuration properties of AGNs, and we discuss its physical implications in the context of co-evolution scenarios.

  15. Experimental proof of quantum non-separability based on the transition of the atom in beta-decay

    International Nuclear Information System (INIS)

    Vatai, E.

    1988-01-01

    The basic non-local character of the quantum processes is a continuously discussed and doubted problem of quantum theory. Recent experimental proofs of the Bell inequalities are questioned in the literature, using local theories of hidden variables. Present paper shows a simple and direct proof of non-locality of quantum processes, analyzing the case of the beta decay. The hypothetical energy transfer between shell electrons and beta electron-neutrino system is proved to be superluminal but necessary for the energy balance of the process. This argumentation proves the nonseparability and nonlocality of quantum processes. (D.G.) 8 refs

  16. Negotiating the COAPRT Learning Outcomes Transition Using Quality Management Tools: A Case Study of the COAPRT Beta Test Site

    Science.gov (United States)

    Ellis, Gary D.

    2014-01-01

    This paper is a case study. It tells the story of the process that the Council on Accreditation for Parks, Recreation, Tourism and Related Professions beta test site created its learning outcomes assessment program. A planning process was used that has evolved from quality management philosophy and practice: DMADV. Use of DMADV required precise…

  17. Sources of beta diversity in estuarine benthic macro-invertebrate communities in the Baltic Sea - North Sea transition

    DEFF Research Database (Denmark)

    Josefson, Alf B.; Göke, Cordula

    Identification of sources of beta diversity, the change of diversity, is important to understand regulation of overall diversity. Additive partitioning of diversity (species richness and expH) compared to random, was performed on a quantitative benthic macro-invertebrate collection of > 400 speci...

  18. Induced Double-Beta Processes in Electron Fluxes as Resonance Reactions in Weak Interaction

    International Nuclear Information System (INIS)

    Gaponov, Yu.V.

    2004-01-01

    A theory of induced double-beta processes in electron beams is developed. It is shown that a resonance mechanism of the excitation of the ground state of an intermediate nucleus is realized in them, this mechanism being described in the single-state-dominance approximation, where the process in question is broken down into two stages, the excitation of a dominant state and its decay. This approximation is valid irrespective of the features of this state, both for allowed (for a 1 + state of the intermediate nucleus) and for forbidden transitions. An analysis of the resonance mechanism reveals that its inclusion in double-beta-decay processes requires introducing additional diagrams that describe the gamma decay of virtual intermediate states. The inclusion of such corrections may lead to a decrease in the expected half-life and to a change in the beta spectrum. Effects associated with the interference between the two stages of a double-beta process are estimated, and it is shown that their influence can be significant if the time interval between these stages is less than or on the order of the lifetime of the dominant state

  19. Double Beta Decay and Neutrino Masses Accuracy of the Nuclear Matrix Elements

    International Nuclear Information System (INIS)

    Faessler, Amand

    2005-01-01

    The neutrinoless double beta decay is forbidden in the standard model of the electroweak and strong interaction but allowed in most Grand Unified Theories (GUT's). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass, the neutrinoless double beta decay is allowed. Apart of one claim that the neutrinoless double beta decay in 76 Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUT's and the minimal R-parity violating supersymmetric model. One further can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUT's. For that one has to assume that the specific mechanism is the leading one for the neutrinoless double beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present contribution, one discusses the accuracy of the present status of calculating the nuclear matrix elements and the corresponding limits of GUT's and supersymmetric parameters

  20. Beta-elemene blocks epithelial-mesenchymal transition in human breast cancer cell line MCF-7 through Smad3-mediated down-regulation of nuclear transcription factors.

    Directory of Open Access Journals (Sweden)

    Xian Zhang

    Full Text Available Epithelial-mesenchymal transition (EMT is the first step required for breast cancer to initiate metastasis. However, the potential of drugs to block and reverse the EMT process are not well explored. In the present study, we investigated the inhibitory effect of beta-elemene (ELE, an active component of a natural plant-derived anti-neoplastic agent in an established EMT model mediated by transforming growth factor-beta1 (TGF-β1. We found that ELE (40 µg/ml blocked the TGF-β1-induced phenotypic transition in the human breast cancer cell line MCF-7. ELE was able to inhibit TGF-β1-mediated upregulation of mRNA and protein expression of nuclear transcription factors (SNAI1, SNAI2, TWIST and SIP1, potentially through decreasing the expression and phosphorylation of Smad3, a central protein mediating the TGF-β1 signalling pathway. These findings suggest a potential therapeutic benefit of ELE in treating basal-like breast cancer.

  1. Warm Dark Matter Sterile Neutrinos in Electron Capture and Beta Decay Spectra

    Directory of Open Access Journals (Sweden)

    O. Moreno

    2016-01-01

    Full Text Available We briefly review the motivation to search for sterile neutrinos in the keV mass scale, as dark matter candidates, and the prospects to find them in beta decay or electron capture spectra, with a global perspective. We describe the fundamentals of the neutrino flavor-mass eigenstate mismatch that opens the possibility of detecting sterile neutrinos in such ordinary nuclear processes. Results are shown and discussed for the effect of heavy neutrino emission in electron capture in Holmium 163 and in two isotopes of Lead, 202 and 205, as well as in the beta decay of Tritium. We study the deexcitation spectrum in the considered cases of electron capture and the charged lepton spectrum in the case of Tritium beta decay. For each of these cases, we define ratios of integrated transition rates over different regions of the spectrum under study and give new results that may guide and facilitate the analysis of possible future measurements, paying particular attention to forbidden transitions in Lead isotopes.

  2. Forbidden fruit: inattention to attractive alternatives provokes implicit relationship reactance.

    Science.gov (United States)

    DeWall, C Nathan; Maner, Jon K; Deckman, Timothy; Rouby, D Aaron

    2011-04-01

    Being inattentive to attractive relationship alternatives can enhance relationship well-being. The current investigation, however, demonstrates that implicitly preventing people from attending to desirable relationship alternatives may undermine, rather than bolster, the strength of that person's romantic relationship. Consistent with the notion of "forbidden fruit," we found that subtly limiting people's attention to attractive alternatives reduced relationship satisfaction and commitment and increased positive attitudes toward infidelity (Experiment 1), increased memory for attractive relationship alternatives (Experiment 2), and increased attention to attractive alternatives (Experiment 3). Findings suggest that although attention to attractive alternatives can harm one's relationship, situations that implicitly limit one's attention to alternatives can, rather ironically, increase the temptation of alternatives and undermine relationship well-being.

  3. Searches for Rare or Forbidden Semileptonic Charm Decays

    International Nuclear Information System (INIS)

    Lees, J.P.

    2011-01-01

    We present searches for rare or forbidden charm decays of the form X c + → h ± (ell) ± (ell) (# prime# )+ , where X c + is a charm hardron (D + , D s + , or Λ c + ), h ± is a pion, kaon, or proton, and (ell) (# prime# )± is an electron or muon. The analysis is based on 384 fb -1 of e + e - annihilation data collected at or close to the Υ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signal is observed for any of the 35 decay modes that are investigated. We establish 90% confidence-level upper limits on the branching fractions between 1 x 10 -6 and 44 x 10 -6 depending on the channel. In most cases, these results represent either the first limits or significant improvements on existing limits for the decay modes studied.

  4. On the chromatic number of a space with forbidden equilateral triangle

    International Nuclear Information System (INIS)

    Zvonarev, A E; Raigorodskii, A M; Kharlamova, A A; Samirov, D V

    2014-01-01

    We improve the Frankl-Rödl estimate for the product of the numbers of edges in uniform hypergraphs with forbidden cardinalities of the intersection of edges. By using this estimate, we obtain explicit bounds for the chromatic number of a space with forbidden monochromatic equilateral triangles. Bibliography: 31 titles

  5. Can $\\beta$-decay probe excited state halos?

    CERN Multimedia

    2002-01-01

    In the first experiment at the newly constructed ISOLDE Facility the first-forbidden $\\beta$-decay of $^{17}$Ne into the first excited state of $^{17}$F has been measured. It is a factor two faster than the corresponding mirror decay and thus gives one of the largest recorded asymmetries for $\\beta$-decays feeding bound final states. Shell-model calculations can only reproduce the asymmetry if the halo structure of the $^{17}$F state is taken into account.

  6. Transcriptional Alterations of Virulence-Associated Genes in Extended Spectrum Beta-Lactamase (ESBL-Producing Uropathogenic Escherichia coli during Morphologic Transitions Induced by Ineffective Antibiotics

    Directory of Open Access Journals (Sweden)

    Isak Demirel

    2017-06-01

    Full Text Available It is known that an ineffective antibiotic treatment can induce morphological shifts in uropathogenic Escherichia coli (UPEC but the virulence properties during these shifts remain to be studied. The present study examines changes in global gene expression patterns and in virulence factor-associated genes in an extended spectrum beta-lactamase (ESBL-producing UPEC (ESBL019 during the morphologic transitions induced by an ineffective antibiotic and in the presence of human primary bladder epithelial cells. Microarray results showed that the different morphological states of ESBL019 had significant transcriptional alterations of a large number of genes (Transition; 7%, Filamentation; 32%, and Reverted 19% of the entities on the array. All three morphological states of ESBL019 were associated with a decreased energy metabolism, altered iron acquisition systems and altered adhesion expression. In addition, genes associated with LPS synthesis and bacterial motility was also altered in all the morphological states. Furthermore, the transition state induced a significantly higher release of TNF-α from bladder epithelial cells compared to all other morphologies, while the reverted state was unable to induce TNF-α release. Our findings show that the morphological shifts induced by ineffective antibiotics are associated with significant transcriptional virulence alterations in ESBL-producing UPEC, which may affect survival and persistence in the urinary tract.

  7. Forbidden Structures for Planar Perfect Consecutively Colourable Graphs

    Directory of Open Access Journals (Sweden)

    Borowiecka-Olszewska Marta

    2017-05-01

    Full Text Available A consecutive colouring of a graph is a proper edge colouring with posi- tive integers in which the colours of edges incident with each vertex form an interval of integers. The idea of this colouring was introduced in 1987 by Asratian and Kamalian under the name of interval colouring. Sevast- janov showed that the corresponding decision problem is NP-complete even restricted to the class of bipartite graphs. We focus our attention on the class of consecutively colourable graphs whose all induced subgraphs are consecutively colourable, too. We call elements of this class perfect consecutively colourable to emphasise the conceptual similarity to perfect graphs. Obviously, the class of perfect consecutively colourable graphs is induced hereditary, so it can be characterized by the family of induced forbidden graphs. In this work we give a necessary and sufficient conditions that must be satisfied by the generalized Sevastjanov rosette to be an induced forbid- den graph for the class of perfect consecutively colourable graphs. Along the way, we show the exact values of the deficiency of all generalized Sevastjanov rosettes, which improves the earlier known estimating result. It should be mentioned that the deficiency of a graph measures its closeness to the class of consecutively colourable graphs. We motivate the investigation of graphs considered here by showing their connection to the class of planar perfect consecutively colourable graphs.

  8. Searches for Rare or Forbidden Semileptonic Charm Decays

    Energy Technology Data Exchange (ETDEWEB)

    Lees, J.P.

    2011-08-15

    We present searches for rare or forbidden charm decays of the form X{sub c}{sup +} {yields} h{sup {+-}}{ell}{sup {-+}}{ell}{sup ({prime})+}, where X{sub c}{sup +} is a charm hardron (D{sup +}, D{sub s}{sup +}, or {Lambda}{sub c}{sup +}), h{sup {+-}} is a pion, kaon, or proton, and {ell}{sup ({prime}){+-}} is an electron or muon. The analysis is based on 384 fb{sup -1} of e{sup +}e{sup -} annihilation data collected at or close to the {Upsilon}(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signal is observed for any of the 35 decay modes that are investigated. We establish 90% confidence-level upper limits on the branching fractions between 1 x 10{sup -6} and 44 x 10{sup -6} depending on the channel. In most cases, these results represent either the first limits or significant improvements on existing limits for the decay modes studied.

  9. First observation of the beta decay of neutron-rich $^{218}Bi$ by the pulsed-release technique and resonant laser ionization

    CERN Document Server

    De Witte, H; Borzov, I N; Caurier, E; Cederkäll, J; De Smet, A; Eckhaudt, S; Fedorov, D V; Fedosseev, V; Franchoo, S; Górska, M; Grawe, H; Huber, G; Huyse, M; Janas, Z; Köster, U; Kurcewicz, W; Kurpeta, J; Plochocki, A; Van Duppen, P; Van de Vel, K; Weissman, L

    2004-01-01

    The neutron-rich isotope /sup 218/Bi has been produced in proton- induced spallation of a uranium carbide target at the ISOLDE facility at CERN, extracted from the ion source by the pulsed-release technique and resonant laser ionization, and its beta decay is studied for the first time. A half-life of 33(1)s was measured and is discussed in the self-consistent continuum-quasi particle-random- phase approximation framework that includes Gamow-Teller and first- forbidden transitions. A level scheme was constructed for /sup 218 /Po, and a deexcitation pattern of stretched E2 transitions 8/sup +/ to 6/sup +/ to 4/sup +/ to 2/sup +/ to 0/sup +/ to the ground state is suggested. Shell-model calculations based on the Kuo-Herling interaction reproduce the experimental results satisfactorily. (28 refs).

  10. The Life of Pi Star: Exploring the Exciting and Forbidden Worlds of the Benzophenone Photophore.

    Science.gov (United States)

    Dormán, György; Nakamura, Hiroyuki; Pulsipher, Abigail; Prestwich, Glenn D

    2016-12-28

    The widespread applications of benzophenone (BP) photochemistry in biological chemistry, bioorganic chemistry, and material science have been prominent in both academic and industrial research. BP photophores have unique photochemical properties: upon n-π* excitation at 365 nm, a biradicaloid triplet state is formed reversibly, which can abstract a hydrogen atom from accessible C-H bonds; the radicals subsequently recombine, creating a stable covalent C-C bond. This light-directed covalent attachment process is exploited in many different ways: (i) binding/contact site mapping of ligand (or protein)-protein interactions; (ii) identification of molecular targets and interactome mapping; (iii) proteome profiling; (iv) bioconjugation and site-directed modification of biopolymers; (v) surface grafting and immobilization. BP photochemistry also has many practical advantages, including low reactivity toward water, stability in ambient light, and the convenient excitation at 365 nm. In addition, several BP-containing building blocks and reagents are commercially available. In this review, we explore the "forbidden" (transitions) and excitation-activated world of photoinduced covalent attachment of BP photophores by touring a colorful palette of recent examples. In this exploration, we will see the pros and cons of using BP photophores, and we hope that both novice and expert photolabelers will enjoy and be inspired by the breadth and depth of possibilities.

  11. BETA digital beta radiometer

    International Nuclear Information System (INIS)

    Borovikov, N.V.; Kosinov, G.A.; Fedorov, Yu.N.

    1989-01-01

    Portable transportable digital beta radiometer providing for measuring beta-decay radionuclide specific activity in the range from 5x10 -9 up to 10 -6 Cu/kg (Cu/l) with error of ±25% is designed and introduced into commercial production for determination of volume and specific water and food radioactivity. The device specifications are given. Experience in the BETA radiometer application under conditions of the Chernobyl' NPP 30-km zone has shown that it is convenient for measuring specific activity of the order of 10 -8 Cu/kg, and application of a set of different beta detectors gives an opportunity to use it for surface contamination measurement in wide range of the measured value

  12. $\\beta$-delayed neutrons from oriented $^{137,139}$I and $^{87,89}$Br nuclei

    CERN Multimedia

    We propose a world-first measurement of the angular distribution of $\\beta$‐delayed n and $\\gamma$-radiation from oriented $^{137, 139}$I and $^{87,89}$Br nuclei, polarised at low temperature at the NICOLE facility. $\\beta$­-delayed neutron emission is an increasingly important decay mechanism as the drip line is approached and its detailed understanding is essential to phenomena as fundamental as the r‐process and practical as the safe operation of nuclear power reactors. The experiments offer sensitive tests of theoretical input concerning the allowed and first­‐forbidden $\\beta$‐decay strength, the spin-density of neutron emitting states and the partial wave barrier penetration as a function of nuclear deformation. In $^{137}$I and $^{87}$Br the decay feeds predominantly the ground state of the daughters $^{136}$Xe and $^{86}$Kr whereas in $^{139}$I and $^{89}$Br we will explore the use of n-$\\gamma$- coincidence to study neutron transitions to the first and second excited states in the daughters...

  13. $\\beta$-delayed neutrons from oriented $^{137,139}$I and $^{87,89}$Br nuclei

    CERN Document Server

    Grzywacz, Robert; Stone, Nicholas; Köster, Ulli; Singh, Barlaj; Bingham, Carrol; Gaulard, S; Kolos, Karolina; Madurga, Miguel; Nikolov, J; Otsubo, T; Roccia, S; Veskovic, Miroslav; Walker, Phil; Walters, William

    2013-01-01

    We propose a world-­‐first measurement of the angular distribution of $\\beta$-­‐delayed n and $\\gamma$- radiation from oriented $^{137, 139}$I and $^{87,89}$Br nuclei, polarised at low temperature at the NICOLE facility. $\\beta$-­‐delayed neutron emission is an increasingly important decay mechanism as the drip line is approached and its detailed understanding is essential to phenomena as fundamental as the r‐process and practical as the safe operation of nuclear power reactors. The experiments offer sensitive tests of theoretical input concerning the allowed and first-­‐forbidden $\\beta$‐decay strength, the spin-­‐density of neutron emitting states and the partial wave barrier penetration as a function of nuclear deformation. In $^{137}$I and $^{87}$Br the decay feeds predominantly the ground state of the daughters $^{136}$Xe and $^{86}$Kr whereas in $^{139}$I and $^{89}$Br we will explore the use of n-$\\gamma$- coincidence to study neutron transitions to the first and second excited state...

  14. TRANSIT

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. TRANSIT. SYSTEM: DETERMINE 2D-POSITION GLOBALLY BUT INTERMITTENT (POST-FACTO). IMPROVED ACCURACY. PRINCIPLE: POLAR SATELLITES WITH INNOVATIONS OF: GRAVITY-GRADIENT ATTITUDE CONTROL; DRAG COMPENSATION. WORKS ...

  15. A minisum model with forbidden regions for locating a semi-desirable facility in the plane

    DEFF Research Database (Denmark)

    Juel, Henrik; Brimberg, Jack

    1998-01-01

    -desirable facility that accounts for the service costs by a standard minisum objective with arbitrary travel distance function. The social costs are imputed by specifying around each demand point or population center a convex forbidden region, also defined by an arbitrary distance metric, in which the new facility...... may not be located. A general solution algorithm is suggested, and the methodology is applied to circular forbidden regions and special travel distance functions....

  16. A minisum model with forbidden regions for locating a semi-desirable facility in the plane

    DEFF Research Database (Denmark)

    Brimberg, Jack; Juel, Henrik

    -desirable facility which accounts for the service costs by a standard minisum objective with arbitrary travel distance function. The social costs are imputed by specifying around each demand point or population center a convex forbidden region, also defined by an arbitrary distance metric, in which the new facility...... may not be located. A general solution algorithm is suggested, and the methodology applied to circular forbidden regions and special travel distance functions....

  17. Long Non-Coding RNA MALAT1 Mediates Transforming Growth Factor Beta1-Induced Epithelial-Mesenchymal Transition of Retinal Pigment Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Shuai Yang

    Full Text Available To study the role of long non-coding RNA (lncRNA MALAT1 in transforming growth factor beta 1 (TGF-β1-induced epithelial-mesenchymal transition (EMT of retinal pigment epithelial (RPE cells.ARPE-19 cells were cultured and exposed to TGF-β1. The EMT of APRE-19 cells is confirmed by morphological change, as well as the increased expression of alpha-smooth muscle actin (αSMA and fibronectin, and the down-regulation of E-cadherin and Zona occludin-1(ZO-1 at both mRNA and protein levels. The expression of lncRNA MALAT1 in RPE cells were detected by quantitative real-time PCR. Knockdown of MALAT1 was achieved by transfecting a small interfering RNA (SiRNA. The effect of inhibition of MALAT1 on EMT, migration, proliferation, and TGFβ signalings were observed. MALAT1 expression was also detected in primary RPE cells incubated with proliferative vitreoretinopathy (PVR vitreous samples.The expression of MALAT1 is significantly increased in RPE cells incubated with TGFβ1. MALAT1 silencing attenuates TGFβ1-induced EMT, migration, and proliferation of RPE cells, at least partially through activating Smad2/3 signaling. MALAT1 is also significantly increased in primary RPE cells incubated with PVR vitreous samples.LncRNA MALAT1 is involved in TGFβ1-induced EMT of human RPE cells and provides new understandings for the pathogenesis of PVR.

  18. Inhibition of glycogen synthase kinase 3beta ameliorates triptolide-induced acute cardiac injury by desensitizing mitochondrial permeability transition

    International Nuclear Information System (INIS)

    Wang, Wenwen; Yang, Yanqin; Xiong, Zhewen; Kong, Jiamin; Fu, Xinlu; Shen, Feihai; Huang, Zhiying

    2016-01-01

    Triptolide (TP), a diterpene triepoxide, is a major active component of Tripterygium wilfordii extracts, which are prepared as tablets and has been used clinically for the treatment of inflammation and autoimmune disorders. However, TP's therapeutic potential is limited by severe adverse effects. In a previous study, we reported that TP induced mitochondria dependent apoptosis in cardiomyocytes. Glycogen synthase kinase-3β (GSK-3β) is a multifunctional serine/threonine kinase that plays important roles in the necrosis and apoptosis of cardiomyocytes. Our study aimed to investigate the role of GSK-3β in TP-induced cardiotoxicity. Inhibition of GSK-3β activity by SB 216763, a potent and selective GSK-3 inhibitor, prominently ameliorated the detrimental effects in C57BL/6J mice with TP administration, which was associated with a correction of GSK-3β overactivity. Consistently, in TP-treated H9c2 cells, SB 216763 treatment counteracted GSK-3β overactivity, improved cell viability, and prevented apoptosis by modulating the expression of Bcl-2 family proteins. Mechanistically, GSK-3β interacted with and phosphorylated cyclophilin F (Cyp-F), a key regulator of mitochondrial permeability transition pore (mPTP). GSK-3β inhibition prevented the phosphorylation and activation of Cyp-F, and desensitized mPTP. Our findings suggest that pharmacological targeting of GSK-3β could represent a promising therapeutic strategy for protecting against cardiotoxicity induced by TP. - Highlights: • GSK-3β inhibition ameliorates TP-induced cardiotoxicity in vitro and in vivo. • GSK-3β controls Cyp-F activation, and regulates mPTP and apoptosis in H9c2 cells. • The protective effect is attributed to GSK-3β activity rather than to protein level. • GSK-3β may be a promising target against TP-induced cardiotoxicity.

  19. Inhibition of glycogen synthase kinase 3beta ameliorates triptolide-induced acute cardiac injury by desensitizing mitochondrial permeability transition

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenwen; Yang, Yanqin; Xiong, Zhewen; Kong, Jiamin [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Fu, Xinlu [Laboratory Animals Center, Sun Yat-sen University, Guangzhou 510006 (China); Shen, Feihai, E-mail: shenfh3@mail.sysu.edu.cn [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Huang, Zhiying, E-mail: hzhiying@mail.sysu.edu.cn [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China)

    2016-12-15

    Triptolide (TP), a diterpene triepoxide, is a major active component of Tripterygium wilfordii extracts, which are prepared as tablets and has been used clinically for the treatment of inflammation and autoimmune disorders. However, TP's therapeutic potential is limited by severe adverse effects. In a previous study, we reported that TP induced mitochondria dependent apoptosis in cardiomyocytes. Glycogen synthase kinase-3β (GSK-3β) is a multifunctional serine/threonine kinase that plays important roles in the necrosis and apoptosis of cardiomyocytes. Our study aimed to investigate the role of GSK-3β in TP-induced cardiotoxicity. Inhibition of GSK-3β activity by SB 216763, a potent and selective GSK-3 inhibitor, prominently ameliorated the detrimental effects in C57BL/6J mice with TP administration, which was associated with a correction of GSK-3β overactivity. Consistently, in TP-treated H9c2 cells, SB 216763 treatment counteracted GSK-3β overactivity, improved cell viability, and prevented apoptosis by modulating the expression of Bcl-2 family proteins. Mechanistically, GSK-3β interacted with and phosphorylated cyclophilin F (Cyp-F), a key regulator of mitochondrial permeability transition pore (mPTP). GSK-3β inhibition prevented the phosphorylation and activation of Cyp-F, and desensitized mPTP. Our findings suggest that pharmacological targeting of GSK-3β could represent a promising therapeutic strategy for protecting against cardiotoxicity induced by TP. - Highlights: • GSK-3β inhibition ameliorates TP-induced cardiotoxicity in vitro and in vivo. • GSK-3β controls Cyp-F activation, and regulates mPTP and apoptosis in H9c2 cells. • The protective effect is attributed to GSK-3β activity rather than to protein level. • GSK-3β may be a promising target against TP-induced cardiotoxicity.

  20. Using forbidden ordinal patterns to detect determinism in irregularly sampled time series.

    Science.gov (United States)

    Kulp, C W; Chobot, J M; Niskala, B J; Needhammer, C J

    2016-02-01

    It is known that when symbolizing a time series into ordinal patterns using the Bandt-Pompe (BP) methodology, there will be ordinal patterns called forbidden patterns that do not occur in a deterministic series. The existence of forbidden patterns can be used to identify deterministic dynamics. In this paper, the ability to use forbidden patterns to detect determinism in irregularly sampled time series is tested on data generated from a continuous model system. The study is done in three parts. First, the effects of sampling time on the number of forbidden patterns are studied on regularly sampled time series. The next two parts focus on two types of irregular-sampling, missing data and timing jitter. It is shown that forbidden patterns can be used to detect determinism in irregularly sampled time series for low degrees of sampling irregularity (as defined in the paper). In addition, comments are made about the appropriateness of using the BP methodology to symbolize irregularly sampled time series.

  1. Tables of double beta decay data

    Energy Technology Data Exchange (ETDEWEB)

    Tretyak, V.I. [AN Ukrainskoj SSR, Kiev (Ukraine)]|[Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Zdesenko, Y.G. [AN Ukrainskoj SSR, Kiev (Ukraine)

    1995-12-31

    A compilation of experimental data on double beta decay is presented. The tables contain the most stringent known experimental limits or positive results of 2{beta} transitions of 69 natural nuclides to ground and excited states of daughter nuclei for different channels (2{beta}{sup -}; 2{beta}{sup +}; {epsilon}{beta}{sup +}; 2{epsilon}) and modes (0{nu}; 2{nu}; 0{nu}M) of decay. (authors). 189 refs., 9 figs., 3 tabs.

  2. Observations of the 63 micron forbidden O I line in Herbig-Haro objects

    International Nuclear Information System (INIS)

    Cohen, M.; Hollenbach, D.J.; Haas, M.R.; Erickson, E.F.

    1988-01-01

    The paper presents observations of the 63 micron forbidden O I line from Herbig-Haro objects and their exciting stars. Forbidden O I 63 micron emission is detected toward the HH-exciting stars T Tau, DG Tau, L1551 IRS 5, and toward the HH objects HH 7-11, HH 42A, and HH 43 which are displaced from their exciting stars. The forbidden O I emission is associated with these flows on the basis of its spatial coincidence and its negative radial velocities. If the exciting stars drive bipolar flows in which the 63 micron emission follows that at 6300 A, the absence of redshifted 63 micron lines from the three exciting stars might indicate that the disks hypothesized to overlie the receding lobes of these flows are still optically thick in the far-infrared. 50 references

  3. Thermal Vibrations of Beta-Brass and the Order-Disorder Transition; Vibrations Thermiques dans le Laiton Beta et Transformation Ordre-Desordre; Teplovye kolebaniya beta-latuni i perekhod iz uporyadochennogo sostoyaniya v razuporyadochennoe; Vibraciones Termicas del Laton Beta y Transicion Orden-Desorden

    Energy Technology Data Exchange (ETDEWEB)

    Dolling, G.; Gilat, G. [Chalk River Nuclear Laboratories, Chalk River, ON (Canada)

    1965-04-15

    Observations of normal modes of vibration of the ordered alloy of copper and zinc, {beta}-brass, at 296 Degree-Sign K have been made by means of the coherent one-phonon scattering of slow neutrons from single crystal specimens. The triple-axis crystal spectrometer at the NRU reactor has been used to measure the frequencies of modes propagating along the high-symmetry directions [00{zeta}], [{zeta}{zeta}0], [{zeta}{zeta}{zeta}{zeta}] and [ Vulgar-Fraction-One-Half Vulgar-Fraction-One-Half {zeta}]. The dispersion curves resemble those of a simple body-centred cubic crystal such as Na, except that certain degeneracies are lifted, mainly by reason of the difference between the second nearest neighbour Cu-Cu and Zn-Zn forces. For example, we find two distinct modes of wave vector (0.5, 0.5, 0.5) (in reciprocal lattice units), whose frequencies are (4.21 {+-}0.06) and (4.93 {+-} 0.10) x 10{sup 12} c/s respectively. Interatomic force models which provide a satisfactory description of the 296 Degree-Sign K results are briefly mentioned. Several normal modes have been studied at elevated temperatures, particularly in the vicinity of the order-disorder phase transition at about 727 Degree-Sign K. There are no striking changes in the overall structure of the dispersion curves as a result of the vanishing of the long range order at this temperature, although the various ''splittings'' observed at 296 Degree-Sign K are blurred out into more or less continuous ''bands'' of frequencies. As the temperature rises, the frequencies generally decrease, and the energy widths increase. These changes take place in a smooth manner, except for two longitudinal optic modes, observed at positions (1.27, 1.27, 0) and (1.2, 1.2, 0.2) in reciprocal space, which display sharp increases in energy width at the transition temperature. No reasonable explanation of these effects has yet been found. (author) [French] On a observe les modes normaux de vibration du laiton beta, alliage ordonne de cuivre

  4. Experimental observation on asymmetric energy flux within the forbidden frequency band in the LC transmission line

    International Nuclear Information System (INIS)

    Tao Feng; Chen Weizhong; Pan Junting; Xu Wen; Du Sidan

    2012-01-01

    We study the energy flux in a nonlinear electrical transmission line consisting of two coupled segments which are identical in structure and different in parameters. The asymmetry of energy flux caused by nonlinear wave has been observed experimentally in the forbidden band of the line. The experiment shows whether the energy can flow through the transmission line depends on the amplitude of the boundary driving voltages, which can be well explained in the theoretical framework of nonlinear supratransmission. The numerical simulation based on Kirchhoff’s laws further verifies the existence of the asymmetric energy flux in the forbidden band.

  5. Oxygen abundance in metal-poor dwarfs, derived from the forbidden line

    Science.gov (United States)

    Spite, M.; Spite, F.

    1991-12-01

    The oxygen abundance is redetermined in a few metal-poor dwarfs, using the oxygen forbidden line at 630 nm rather than the oxygen triplet at 777 nm previously used by Abia and Rebolo (1989). The ratios form O/Fe are clearly lower than the previous ones and are in agreement with the ratios found in the metal-poor red giants, suggesting that no real difference exists between dwarfs and giants. Finally, it can be argued that, pending the acquisition of additional information, the oxygen abundances derived from the forbidden line are more reliable than the abundances found from the triplet.

  6. Induced nuclear beta decay

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1986-01-01

    Certain nuclear beta decay transitions normally inhibited by angular momentum or parity considerations can be induced to occur by the application of an electromagnetic field. Such decays can be useful in the controlled production of power, and in fission waste disposal

  7. Speculative Betas

    OpenAIRE

    Harrison Hong; David Sraer

    2012-01-01

    We provide a model for why high beta assets are more prone to speculative overpricing than low beta ones. When investors disagree about the common factor of cash-flows, high beta assets are more sensitive to this macro-disagreement and experience a greater divergence-of-opinion about their payoffs. Short-sales constraints for some investors such as retail mutual funds result in high beta assets being over-priced. When aggregate disagreement is low, expected return increases with beta due to r...

  8. Structure of two-, four-, and six-quasiparticle isomers in 174Yb and K-forbidden decays

    Science.gov (United States)

    Dracoulis, G. D.; Lane, G. J.; Kondev, F. G.; Byrne, A. P.; Kibédi, T.; Watanabe, H.; Ahmad, I.; Carpenter, M. P.; Freeman, S. J.; Janssens, R. V.; Hammond, N. J.; Lauritsen, T.; Lister, C. J.; Mukherjee, G.; Seweryniak, D.; Chowdhury, P.; Tandel, S. K.

    2005-04-01

    The stable nucleus 174Yb has been studied using deep-inelastic reactions and time-correlated γ-ray spectroscopy. New intrinsic states assigned include a 370-ns isomer at 1765 keV, which we associate with a predicted Kπ=7- two-quasineutron configuration. Analysis of the alignment and in-band properties of its rotational band, identified using time-correlated coincidences, allows characterization of the configuration. The properties of a newly identified rotational band built on the known 830-μs isomer at 1518 keV support the 6+, 2-quasineutron configuration assignment proposed previously. The 6+ band is fed by a four-quasiparticle, Kπ=14+ isomer at 3699 keV and several higher multiquasiparticle states, including a six-quasiparticle isomer at 6147 keV with K=(22,23). The results are discussed in terms of the states predicted on the basis of multiquasiparticle calculations. The anomalously fast K-forbidden transition strengths from the 14+ isomer are attributed to either K mixing in the neutron configuration or to random mixing in the high-level-density region. The 7- isomer decays are not abnormal, whereas the very hindered E2 transition from the 6+ isomer to the ground-state band remains unexplained.

  9. DETECTION OF FORBIDDEN LINE COMPONENTS OF LITHIUM-LIKE CARBON IN STELLAR SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Klaus; Rauch, Thomas; Hoyer, Denny [Institute for Astronomy and Astrophysics, Kepler Center for Astro and Particle Physics, Eberhard Karls University Tübingen, Sand 1, D-72076 Tübingen (Germany); Quinet, Pascal [Physique Atomique et Astrophysique, Université de Mons—UMONS, B-7000 Mons (Belgium)

    2016-08-10

    We report the first identification of forbidden line components from an element heavier than helium in the spectrum of astrophysical plasmas. So far, these components were identified only in laboratory plasmas and not in astrophysical objects. Forbidden components are well known for neutral helium lines in hot stars, particularly in helium-rich post-AGB stars and white dwarfs. We discovered that two hitherto unidentified lines in the ultraviolet spectra of hot hydrogen-deficient (pre-) white dwarfs can be identified as forbidden line components of triply ionized carbon (C iv). The forbidden components (3p–4f and 3d–4d) appear in the blue and red wings of the strong, Stark broadened 3p–4d and 3d–4f lines at 1108 Å and 1169 Å, respectively. They are visible over a wide effective temperature range (60,000–200,000 K) in helium-rich (DO) white dwarfs and PG 1159 stars that have strongly oversolar carbon abundances.

  10. Spatial Distribution of the Forbidden 1.707 mm Rovibronic Emission on Io

    Science.gov (United States)

    de Pater, Imke; de Kleer, Katherine; Adamkovics, Mate

    2017-10-01

    Io’s forbidden SO 1.707 mm rovibronic transition was discovered in 1999 when the satellite was observed with the NIRSPEC spectrometer on the Keck telescope while in eclipse [1]. The emission, at the time indicative of a rotational temperature of 1000 K, was attributed to SO molecules in the excited a1D state, ejected as such from the vent at a thermodynamic quenching temperature of ~1500 K. We suggested Loki as its source, a volcano that was exceptionally active during this period. In subsequent years we found that the disk-averaged SO emission varies substantially over time [2]. In November 2002 we observed Io in eclipse with Keck’s NIRSPEC coupled to the Adaptive Optics (AO) system, and identified a latitudinal variation in SO: most emission came from the equator and the south, and practically no emission was detected in the north [3]. To further investigate the nature of the SO emission, we observed Io in eclipse with the near-infrared integral field spectrograph OSIRIS, coupled to the AO system, on the Keck II telescope on UT 27 July 2010 and 25 December 2015. On the latter date we observed simultaneously with the NIRSPEC spectrometer at a high spectral resolution (R ~ 25,000). On these dates Callisto and Ganymede, resp., were close enough to be used for wavefront sensing. The angular resolution of our images is ~0.1”, or ~10 resolution elements across Io’s disk. The emission is extended; preliminary results show that in 2010 most of the emission originated in the north, and in 2015 it appeared to be more confined to the equatorial region. Potential connections to active volcanoes, or absence thereof, and model fits to the emission bands including LTE vs non-LTE contributions will be discussed. [1]: de Pater, I., et al., 2002. Icarus, 156, 296-301.[2]: Laver, C., et al. 2007. Icarus, 189, 401-408.[3]: de Pater, I. et al., 2007. Icarus, 191, 172-182.

  11. Origins of Beta Tantalum in Sputtered Coatings

    National Research Council Canada - National Science Library

    Mulligan, C

    2001-01-01

    .... Some of the most recent work has attempted to relate the energetics (i.e., atom/ion energy) of the plasma to the alpha right arrow beta transition. It has been shown that the energetics of the plasma can relate to the most crucial sputtering parameters. The most significant feature of the use of plasma energy to explain the alpha right arrow beta transition is that it relates the formation of beta-tantalum to a quantifiable measure.

  12. Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

    Science.gov (United States)

    Cheng, X.; Ding, M. D.

    2016-05-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s-1 and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (˜11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

  13. SPECTROSCOPIC DIAGNOSTICS OF SOLAR MAGNETIC FLUX ROPES USING IRON FORBIDDEN LINE

    International Nuclear Information System (INIS)

    Cheng, X.; Ding, M. D.

    2016-01-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s"−"1 and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (∼11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

  14. SPECTROSCOPIC DIAGNOSTICS OF SOLAR MAGNETIC FLUX ROPES USING IRON FORBIDDEN LINE

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, X.; Ding, M. D., E-mail: xincheng@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

    2016-05-20

    In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s{sup −1} and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (∼11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

  15. Spin-polarized x-ray emission of 3d transition-metal ions : A comparison via K alpha and K beta detection

    NARCIS (Netherlands)

    Wang, Xin; deGroot, F.M.F.; Cramer, SP

    1997-01-01

    This paper demonstrates that spin-polarized x-ray-excitation spectra can be obtained using K alpha emission as well as K beta lines. A spin-polarized analysis of K alpha x-ray emission and the excitation spectra by K alpha detection on a Ni compound is reported. A systematic analysis of the

  16. Beta spectrometry

    International Nuclear Information System (INIS)

    Dryak, P.; Zderadicka, J.; Plch, J.; Kokta, L.; Novotna, P.

    1977-01-01

    For the purpose of beta spectrometry, a semiconductor spectrometer with one Si(Li) detector cooled with liquid nitrogen was designed. Geometrical detection efficiency is about 10% 4 sr. The achieved resolution for 624 keV conversion electrons of sup(137m)Ba is 2.6 keV (FWHM). A program was written in the FORTRAN language for the correction of the deformation of the measured spectra by backscattering in the analysis of continuous beta spectra. The method permits the determination of the maximum energy of the beta spectrum with an accuracy of +-5 keV. (author)

  17. Beta Blockers

    Science.gov (United States)

    ... may not work as effectively for people of African heritage and older people, especially when taken without ... conditions/high-blood-pressure/in-depth/beta-blockers/ART-20044522 . Mayo Clinic Footer Legal Conditions and Terms ...

  18. Constraints on parity-mixing matrix elements from hard-pion exchange corrections to first-forbidden beta decays

    International Nuclear Information System (INIS)

    Kirchbach, M.

    1986-01-01

    In this paper the experience in extracting the value of the weak pion-nucleon coupling constant f/sub π//sup l/ from the parity-mixing matrix element + , T = 1; 1.042 MeV | V/sub PNC/ | O - , T = 0; 1.081 MeV> in 18 F is summarized with the aim to reveal some sources of uncertainties of the models exploited. We show that beyond of the long wavelenth approximation and in treating non-soft pion corrections to the two-body nuclear chiral charge density an upper bound for f/sub π//sup l/ is obtained which is about two times smaller as compared to results of previous analyses of similar character. Finally, we accentuate on the importance of the heavy-meson exchanges in the weak NN-potential for understanding recent measurement results of f/sub π//sup l/ which strongly deviate from earlier data. (author)

  19. Observation of forbidden (E2) lines in the ultraviolet spectra of Ca II, Sr II, and Ba II by inductively coupled plasma emission spectroscopy

    International Nuclear Information System (INIS)

    Doidge, Peter S.

    2013-01-01

    Forbidden (electric quadrupole, E2) transitions of the type ns 2 S 1/2 –nd 2 D 3/2 and ns 2 S 1/2 –nd 2 D 5/2 in the ultraviolet spectra of singly ionized Ca, Sr, and Ba (with n = 4, 5 or 6 for Ca, Sr, and Ba, respectively) have been observed in the emission spectrum of an inductively coupled argon plasma. Wavelengths and wavenumbers of the six lines are reported and the values are in good agreement with those expected from literature data for the energy levels involved. - Highlights: • Wavelengths measured using commercially available ICP emission spectrometer • First wavelength and wavenumber measurements of some E2 lines of Ba +, Ca +, Sr + • Evidence for small plasma shifts in the wavenumbers of Ba + and Sr +

  20. Forbidden Access

    CERN Multimedia

    C. Colloca TS/FM

    2004-01-01

    TS/FM group informs you that, for the replacement of the door of the main entrance at bldg. 500, the access will be closed to the public between 19 and 30 July 2004. Access to the Main Building complex will be assured at any time through both of the side doors and from bldg. 64. For more information, please contact 73273. C. Colloca TS/FM

  1. Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

    OpenAIRE

    Cheng, X.; Ding, M. D.

    2016-01-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe XXI 1354.08 A forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of $\\ge$1000 km s$^{-1}$ and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The EUV images at the 131 A and 94 A passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot c...

  2. Data supporting beta-amyloid dimer structural transitions and protein–lipid interactions on asymmetric lipid bilayer surfaces using MD simulations on experimentally derived NMR protein structures

    Directory of Open Access Journals (Sweden)

    Sara Y. Cheng

    2016-06-01

    Full Text Available This data article supports the research article entitled “Maximally Asymmetric Transbilayer Distribution of Anionic Lipids Alters the Structure and interaction with Lipids of an Amyloidogenic Protein Dimer Bound to the Membrane Surface” [1]. We describe supporting data on the binding kinetics, time evolution of secondary structure, and residue-contact maps of a surface-absorbed beta-amyloid dimer protein on different membrane surfaces. We further demonstrate the sorting of annular and non-annular regions of the protein/lipid bilayer simulation systems, and the correlation of lipid-number mismatch and surface area per lipid mismatch of asymmetric lipid membranes.

  3. Beta and muon decays

    International Nuclear Information System (INIS)

    Galindo, A.; Pascual, P.

    1967-01-01

    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)

  4. 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)

  5. Age and violent-content labels make video games forbidden fruits for youth.

    Science.gov (United States)

    Bijvank, Marije Nije; Konijn, Elly A; Bushman, Brad J; Roelofsma, Peter H M P

    2009-03-01

    To protect minors from exposure to video games with objectionable content (eg, violence and sex), the Pan European Game Information developed a classification system for video games (eg, 18+). We tested the hypothesis that this classification system may actually increase the attractiveness of games for children younger than the age rating. Participants were 310 Dutch youth. The design was a 3 (age group: 7-8, 12-13, and 16-17 years) x 2 (participant gender) x 7 (label: 7+, 12+, 16+, 18+, violence, no violence, or no label control) x 2 (game description: violent or nonviolent) mixed factorial. The first 2 factors were between subjects, whereas the last 2 factors were within subjects. Three personality traits (ie, reactance, trait aggressiveness, and sensation seeking) were also included in the analyses. Participants read fictitious video game descriptions and rated how much they wanted to play each game. Results revealed that restrictive age labels and violent-content labels increased the attractiveness of video games for all of the age groups (even 7- to 8-year-olds and girls). Although the Pan European Game Information system was developed to protect youth from objectionable content, this system actually makes such games forbidden fruits. Pediatricians should be aware of this forbidden-fruit effect, because video games with objectionable content can have harmful effects on children and adolescents.

  6. Nuclear beta decay and the weak interaction

    International Nuclear Information System (INIS)

    Kean, D.C.

    1975-11-01

    Short notes are presented on various aspects of nuclear beta decay and weak interactions including: super-allowed transitions, parity violation, interaction strengths, coupling constants, and the current-current formalism of weak interaction. (R.L.)

  7. Radio ejection and broad forbidden emission lines in the Seyfert galaxy NGC 7674

    International Nuclear Information System (INIS)

    Unger, S.W.; Pedlar, A.; Axon, D.J.

    1988-01-01

    The Seyfert nucleus in NGC7674 (Mkn533) is remarkable for its broad asymmetric forbidden line profiles, which extend 2000 kms -1 blueward of the systemic velocity. The galaxy also has a compact nuclear radio source. We have obtained new high-resolution radio observations of NGC7674, using the European VLBI network and the VLA, and optical spectroscopic observations using the Isaac Newton Telescope. The radio maps reveal a triple radio source with a total angular extent of about 0.7 arcsec, and provide evidence that the radio emission is powered by collimated ejection. In the plane of the sky, the ejection axis appears roughly perpendicular to the galactic rotation axis. Although the dominant radio components are separated by 0.5 arcsec, the broad [OIII]λ5007 line emission is confined to within about 0.25 arcsec of the continuum nucleus. (author)

  8. A search for rare and forbidden decays of η-meson with GAMS-4π

    International Nuclear Information System (INIS)

    Binon, F.; Blik, A.; Gorin, A.; Donskov, S.; Inaba, S.; Kolosov, V.; Ladygin, M.; Lednev, A.; Lishin, V.; Manuilov, I.; Mikhailov, Yu.; Pegneux, J.P.; Polyakov, V.; Samoylenko, V.; Sobol, A.; Stroot, J.P.; Sugonyaev, V.; Takamatsu, K.; Tsuru, T.; Khaustov, G.

    2006-01-01

    A search for the rare and forbidden neutral decays of η-meson with the GAMS-4π setup has been performed. The charge-exchange reaction at 32.5 GeV/c was used as a source of 3.7-bar 10 6 η-mesons. At the 90% confidence level the following upper limits were obtained: BR(η->3γ) -4 , BR(η->4γ) -4 , BR(η->π o π o ) -4 , BR(η->π o π o γ) -3 , BR(η->π o π o γγ) -3 , BR(η->3π o γ) -4 , BR(η->4π o ) -5

  9. Generalized laws of refraction that can lead to wave-optically forbidden light-ray fields.

    Science.gov (United States)

    Courtial, Johannes; Tyc, Tomáš

    2012-07-01

    The recent demonstration of a metamaterial phase hologram so thin that it can be classified as an interface in the effective-medium approximation [Science 334, 333 (2011)] has dramatically increased interest in generalized laws of refraction. Based on the fact that scalar wave optics allows only certain light-ray fields, we divide generalized laws of refraction into two categories. When applied to a planar cross section through any allowed light-ray field, the laws in the first category always result in a cross section through an allowed light-ray field again, whereas the laws in the second category can result in a cross section through a forbidden light-ray field.

  10. Forbidden Raman scattering processes. I. General considerations and E1--M1 scattering

    International Nuclear Information System (INIS)

    Harney, R.C.

    1979-01-01

    The generalized theory of forbidden Raman scattering processes is developed in terms of the multipole expansion of the electromagnetic interaction Hamiltonian. Using the general expressions, the theory of electric dipole--magnetic dipole (E1--M1) Raman scattering is derived in detail. The 1 S 0 → 3 P 1 E1--M1 Raman scattering cross section in atomic magnesium is calculated for two applicable laser wavelengths using published f-value data. Since resonantly enhanced cross sections larger than 10 -29 cm 2 /sr are predicted it should be possible to experimentally observe this scattering phenomenon. In addition, by measuring the frequency dependence of the cross section near resonance, it may be possible to directly determine the relative magnitudes of the Axp and AxA contributions to the scattering cross section. Finally, possible applications of the effect in atomic and molecular physics are discussed

  11. Observation of electric quadrupole transitions to Rydberg nd states of ultracold rubidium atoms

    NARCIS (Netherlands)

    Tong, D.; Farooqi, S.M.; Kempen, van E.G.M.; Pavlovic, Z.; Stanojevic, J.; Coté, R.; Eyler, E.E.; Gould, P.L.

    2009-01-01

    We report the observation of dipole-forbidden, but quadrupole-allowed, one-photon transitions to high-Rydberg states in Rb. Using pulsed uv excitation of ultracold atoms in a magneto-optical trap, we excite 5s¿nd transitions over a range of principal quantum numbers n=27–59. Compared to

  12. Strengths of gamma-ray transitions in A = 6–44 nuclei (III)

    NARCIS (Netherlands)

    Endt, P.M.

    The present tables list the strengths (in Weisskopf units) of over 2400 γ-ray transitions in A = 6–44 nuclei, classified according to character (electric or magnetic, multipolarity, isospin forbiddenness). Selected transitions from unbound states are included. The strengths for isovector E1 and M1

  13. Beyond neutral and forbidden links: morphological matches and the assembly of mutualistic hawkmoth-plant networks.

    Science.gov (United States)

    Sazatornil, Federico D; Moré, Marcela; Benitez-Vieyra, Santiago; Cocucci, Andrea A; Kitching, Ian J; Schlumpberger, Boris O; Oliveira, Paulo E; Sazima, Marlies; Amorim, Felipe W

    2016-11-01

    A major challenge in evolutionary ecology is to understand how co-evolutionary processes shape patterns of interactions between species at community level. Pollination of flowers with long corolla tubes by long-tongued hawkmoths has been invoked as a showcase model of co-evolution. Recently, optimal foraging models have predicted that there might be a close association between mouthparts' length and the corolla depth of the visited flowers, thus favouring trait convergence and specialization at community level. Here, we assessed whether hawkmoths more frequently pollinate plants with floral tube lengths similar to their proboscis lengths (morphological match hypothesis) against abundance-based processes (neutral hypothesis) and ecological trait mismatches constraints (forbidden links hypothesis), and how these processes structure hawkmoth-plant mutualistic networks from five communities in four biogeographical regions of South America. We found convergence in morphological traits across the five communities and that the distribution of morphological differences between hawkmoths and plants is consistent with expectations under the morphological match hypothesis in three of the five communities. In the two remaining communities, which are ecotones between two distinct biogeographical areas, interactions are better predicted by the neutral hypothesis. Our findings are consistent with the idea that diffuse co-evolution drives the evolution of extremely long proboscises and flower tubes, and highlight the importance of morphological traits, beyond the forbidden links hypothesis, in structuring interactions between mutualistic partners, revealing that the role of niche-based processes can be much more complex than previously known. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

  14. CCAAT/enhancer binding protein beta (C/EBPβ) isoform balance as a regulator of epithelial-mesenchymal transition in mouse mammary epithelial cells

    International Nuclear Information System (INIS)

    Miura, Yuka; Hagiwara, Natsumi; Radisky, Derek C.; Hirai, Yohei

    2014-01-01

    Activation of the epithelial-mesenchymal transition (EMT) program promotes cell invasion and metastasis, and is reversed through mesenchymal-epithelial transition (MET) after formation of distant metastases. Here, we show that an imbalance of gene products encoded by the transcriptional factor C/EBPβ, LAP (liver-enriched activating protein) and LIP (liver-enriched inhibitory protein), can regulate both EMT- and MET-like phenotypic changes in mouse mammary epithelial cells. By using tetracycline repressive LIP expression constructs, we found that SCp2 cells, a clonal epithelial line of COMMA1-D cells, expressed EMT markers, lost the ability to undergo alveolar-like morphogenesis in 3D Matrigel, and acquired properties of benign adenoma cells. Conversely, we found that inducible expression of LAP in SCg6 cells, a clonal fibroblastic line of COMMA1-D cells, began to express epithelial keratins with suppression of proliferation. The overexpression of the C/EBPβ gene products in these COMMA1-D derivatives was suppressed by long-term cultivation on tissue culture plastic, but gene expression was maintained in cells grown on Matrigel or exposed to proteasome inhibitors. Thus, imbalances of C/EBPβ gene products in mouse mammary epithelial cells, which are affected by contact with basement membrane, are defined as a potential regulator of metastatic potential. - Highlights: • We created a temporal imbalance of C/EBPβ gene products in the mammary model cells. • The temporal up-regulation of LIP protein induced EMT-like cell behaviors. • The temporal up-regulation of LAP protein induced MET-like cell behaviors. • Excess amount of C/EBPβ gene products were eliminated by proteasomal-degradation. • Basement membrane components attenuated proteasome-triggered protein elimination

  15. Electric field measurements from satellites-to-forbidden line ratios in an Omega-Upgrade laser-produced plasma. Semi-annual report, February 1--May 31, 1996

    International Nuclear Information System (INIS)

    Griem, H.R.; Elton, R.C.; Welch, B.L.

    1996-01-01

    Under this FY-96 NLUF program, the authors began their search for satellite lines to forbidden transitions for localized laser-induced electric field measurements by preparing in their laboratory a flat-field grazing incidence spectrograph for use on the OMEGA-Upgrade facility. This involved wavelength calibration using a (small) laser-produced plasma, as well as designing and constructing a mounting table compatible with the large 60-beam target chamber at LLE. Beginning in April 1996 they installed and aligned the spectrograph at LLE. Following final alignment on Monday, April 29, they obtained the following day their first time-integrated spectral data in the 30--250 angstrom range. A total of 28 successful shots were obtained. For most shots, two beams of the OMEGA-Upgrade laser were used at nominal uv-pulse widths of 1.1 ns and energies ranging from 76--470 J/beam, with focal spots of 80--450 microm and irradiances covering approximately 10 14 --10 16 Watt/cm 2 . Planar targets used consisted of Mg and NaF, as well as boron mounted on a plastic film, with some of the former two overcoated with 5 microm of CH on each side for containing the plasma, at least during the early portion of the pulse. Preliminary analyses indicate that they do indeed observe the desired Li-like L-shell spectra for oxygen, fluorine, sodium and magnesium, as well as L-shell lines in the corresponding H-(Balmer) and He-like species. Similarly, they recorded K-shell lines from B and C. Sample traces for Mg and Na fluoride from their soft x-ray spectrograph are shown. Both of these shots were obtained at a rather low applied irradiance of 2 X 10 14 W/cm 2 , and were chosen mainly for line identification. The parent Li-like 2s-3p allowed lines corresponding to the forbidden-line satellites sought for E-field determinations are clearly present. The calculated satellite line intensity relative to the intensity from this 2s-3p transition is ∼ 3%

  16. Gufa, a unique cultural ritual--a tale of forbidden sun and a girl

    Science.gov (United States)

    Shrestha, Pritisha

    2015-08-01

    Gufa, one of the traditional rituals has been performed in Nepal since time immemorial by an especial indigenous Newar people. Gufa, in its literal translation means cave. Just like in the cave where darkness seeps deep within its wall as the sun’s ray cannot penetrate, in the ritual of Gufa, a young girl who just had her first period is hidden in a dark room for twelve consecutive days. The girl, by strict custom and ritual performance stays in the room, protected from the sun’s light. From her female elders, she also receives informal education on family and societal values and norms.Sun, the reason behind our existence, is forbidden for the girl to observe. This very aspect of purely shunning away from the sun has become the crucial aspect for delving into the explanations offered by cultural astronomy. The present paper would argue that astronomy and astronomy education should not only focus on looking into the future, but also should go back to the ancient civilization to comprehend ritual performance our forefathers had learned from gazing the sky.After twelve days, the girl is carefully brought out to an open space where she sees the forbidden sun and symbolically marries the star via ritual. The logic behind the union after a pure restriction is to protect her sensitive young body and to ward off any harm to her reproductive parts from the sun’s harsh rays.From astronomical point, this logic behind protecting the girl from the effects of then deemed harmful rays should be studied. In ancient times, who with which instruments could have possibly fathom the life-giving sun could harness harmful solar rays. Although it looks like a primitive custom of hiding the girl immediately during her first period, there are logical social, cultural and scientific reasons for doing it even today in modern, urban and among the educated Newar households of Nepal and abroad.The paper would expound the importance of traditional ritual performance and its nexus with

  17. Kinematic shifts of beta -delayed particles as a probe of beta - nu angular correlations

    CERN Document Server

    Clifford, E T H; Evans, H C; Fästermann, T; Hagberg, E; Hardy, J C; Jackson, K P; Koslowsky, V T; Schmeing, H; Schrewe, U J

    1981-01-01

    Beta-delayed particles undergo a kinematic shift in energy due to recoil motion of the daughter nucleus following beta decay. A careful measurement of this energy shift can be used to establish the ratio of vector to axial vector components in beta transitions. Alpha-beta coincidence data for the beta-delayed alpha decay of /sup 20/Na have been obtained. Component ratios for 6 transitions including the superallowed branch are found. Limits on charge dependent mixing with the analogue state are deduced for 5 states in /sup 20/Ne*. For the superallowed branch the axial vector component is found; the polar vector component is deduced and establishes a value for the vector weak coupling constant of G/sub V/=(1.355+or-0.036)*10/sup -49/ erg cm /sup 3/. (13 refs).

  18. Multiplex PCR assay for the detection of five meat species forbidden in Islamic foods.

    Science.gov (United States)

    Ali, Md Eaqub; Razzak, Md Abdur; Hamid, Sharifah Bee Abd; Rahman, Md Mahfujur; Amin, Md Al; Rashid, Nur Raifana Abd; Asing

    2015-06-15

    Food falsification has direct impact on public health, religious faith, fair-trades and wildlife. For the first time, here we described a multiplex polymerase chain reaction assay for the accurate identification of five meat species forbidden in Islamic foods in a single assay platform. Five pairs of species-specific primers were designed targeting mitochondrial ND5, ATPase 6, and cytochrome b genes to amplify 172, 163, 141, 129 and 108 bp DNA fragments from cat, dog, pig, monkey and rat meats, respectively. All PCR products were identified in gel-images and electrochromatograms obtained from Experion Bioanalyzer. Species-specificity checking against 15 important meat and fish and 5 plant species detected no cross-species amplification. Screening of target species in model and commercial meatballs reflected its application to detect target species in process foods. The assay was tested to detect 0.01-0.02 ng DNA under raw states and 1% suspected meats in meatball formulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Exploration of the forbidden regions of the Ramachandran plot (ϕ-ψ) with QTAIM.

    Science.gov (United States)

    Momen, Roya; Azizi, Alireza; Wang, Lingling; Ping, Yang; Xu, Tianlv; Kirk, Steven R; Li, Wenxuan; Manzhos, Sergei; Jenkins, Samantha

    2017-10-04

    A new QTAIM interpretation of the Ramachandran plot is formulated from the most and least facile eigenvectors of the second-derivative matrix of the electron density with a set of 29 magainin-2 peptide conformers. The presence of QTAIM eigenvectors associated with the most and least preferred directions of electronic charge density explained the role of hydrogen bonding, HH contacts and the glycine amino acid monomer in peptide folding. The highest degree of occupation of the QTAIM interpreted Ramachandran plot was found for the glycine amino acid monomer compared with the remaining backbone peptide bonds. The mobility of the QTAIM eigenvectors of the glycine amino acid monomer was higher than for the other amino acids and was comparable to that of the hydrogen bonding, explaining the flexibility of the magainin-2 backbone. We experimented with a variety of hybrid QTAIM-Ramachandran plots to highlight and explain why the glycine amino acid monomer largely occupies the 'forbidden' region on the Ramachandran plot. In addition, the new hybrid QTAIM-Ramachandran plots contained recognizable regions that can be associated with concepts familiar from the conventional Ramachandran plot whilst retaining the character of the QTAIM most and least preferred regions.

  20. Asymptotic Structure in the Classically Forbidden Region of the Hooke's Atoms

    International Nuclear Information System (INIS)

    Wang Xuemei

    2013-01-01

    The two-electron Hooke's atom — a quantum mechanical system with two electrons bound in a harmonic potential — is well known for its exact analytical properties at certain oscillator strengths. The Hooke's atoms with more than two electrons offer more scope for valuable practical applications. In this work, we study the asymptotic structure of these Hooke's atoms in the classically forbidden region. The leading-order term of the long-range expression for the KS exchange-correlation potential v xc (r) is shown to be −1/r. The second and third higher order terms are also exactly obtained. Various components of v xc (r) are also studied. It is shown that the leading term of O(1/r) in v xc (r) is due to the pure Pauli correlation, while the leading contribution of the Coulomb correlation is of O(1/r 3 ). Neither of them makes contribution to the term of O(1/r 2 ), which is shown to be solely due to the kinetic correlation effect. Results for the two-electron Hooke's atom were obtained before in the literature. Our results reduce to those of the two-electron Hooke's atom as a special case. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  1. A search for rare and forbidden decays of {eta}-meson with GAMS-4{pi}

    Energy Technology Data Exchange (ETDEWEB)

    Binon, F. [Universite Libre de Bruxelles, CP 229, B-1050 Brussels (Belgium); Blik, A. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Gorin, A. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Donskov, S. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Inaba, S. [National Laboratory for High Energy Physics - KEK, Tsukuba, Ibaraki 305-0801 (Japan); Kolosov, V. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Ladygin, M. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Lednev, A. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Lishin, V. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Manuilov, I. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Mikhailov, Yu. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Pegneux, J.P. [Laboratoire d' Annecy de Physique des Particules, F-74019 Annecy-le-Vieux (France); Polyakov, V. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Samoylenko, V. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Sobol, A. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Stroot, J.P. [Universite Libre de Bruxelles, CP 229, B-1050 Brussels (Belgium); Sugonyaev, V. [Institute for High Energy Physics, 142281, Protvino (Russian Federation); Takamatsu, K. [National Laboratory for High Energy Physics - KEK, Tsukuba, Ibaraki 305-0801 (Japan); Tsuru, T. [National Laboratory for High Energy Physics - KEK, Tsukuba, Ibaraki 305-0801 (Japan); Khaustov, G. [Institute for High Energy Physics, 142281, Protvino (Russian Federation)

    2006-12-15

    A search for the rare and forbidden neutral decays of {eta}-meson with the GAMS-4{pi} setup has been performed. The charge-exchange reaction at 32.5 GeV/c was used as a source of 3.7-bar 10{sup 6}{eta}-mesons. At the 90% confidence level the following upper limits were obtained: BR({eta}->3{gamma})<1.6-bar 10{sup -4}, BR({eta}->4{gamma})<2.8-bar 10{sup -4}, BR({eta}->{pi}{sup o}{pi}{sup o})<3.5-bar 10{sup -4}, BR({eta}->{pi}{sup o}{pi}{sup o}{gamma})<1.7-bar 10{sup -3}, BR({eta}->{pi}{sup o}{pi}{sup o}{gamma}{gamma})<4.0-bar 10{sup -3}, BR({eta}->3{pi}{sup o}{gamma})<2.4-bar 10{sup -4}, BR({eta}->4{pi}{sup o})<2.0-bar 10{sup -5}.

  2. Three-quasiparticle isomer in 173Ta and the excitation energy dependence of K -forbidden transition rates

    OpenAIRE

    Wood, RT; Walker, PM; Lane, G J; Carroll, R. J.; Cullen, David; Dracoulis, G D; Hota, S. S.; Kibédi, T.; Palalani, N; Podolyak, Zs.; Reed, MW; Schiffl, K; Wright, A.M

    2017-01-01

    Using the 168Er(10B,5n) reaction at a beam energy of 68 MeV, new data have been obtained for the population and decay of a T1/2=148ns, Kπ=21/2− three-quasiparticle isomer at 1717 keV in 173Ta. Revised decay energies and intensities have been determined, together with newly observed members of a rotational band associated with the isomer. By comparison with other isomers in the A≈180 deformed region, the 173Ta isomer properties help to specify the key degrees of freedom that determine K-forbid...

  3. Milk Intolerance, Beta-Casein and Lactose.

    Science.gov (United States)

    Pal, Sebely; Woodford, Keith; Kukuljan, Sonja; Ho, Suleen

    2015-08-31

    True lactose intolerance (symptoms stemming from lactose malabsorption) is less common than is widely perceived, and should be viewed as just one potential cause of cows' milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows' milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows' milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed.

  4. Milk Intolerance, Beta-Casein and Lactose

    Directory of Open Access Journals (Sweden)

    Sebely Pal

    2015-08-01

    Full Text Available True lactose intolerance (symptoms stemming from lactose malabsorption is less common than is widely perceived, and should be viewed as just one potential cause of cows’ milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows’ milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows’ milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed.

  5. Quantum-chemical studies of quasi-one-dimensional electron systems. Part 2. Cumulenes and origin of the forbidden zone

    Directory of Open Access Journals (Sweden)

    Yuriy Kruglyak

    2015-06-01

    Full Text Available This review is devoted to the basic problem in quantum theory of quasi-one-dimensional electron systems like polyenes (Part 1 and cumulenes (Part 2 – physical origin of the forbidden zone in these and analogous 1D electron systems due to two possible effects – Peierls instability (bond alternation and Mott instability (electron correlation. Both possible contradiction and coexistence of the Mott and Peierls instabilities are summerized on the basis of the Kiev quantum chemistry team research projects.

  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. Beta Emission and Bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-13

    Bremsstrahlung is continuous radiation produced by beta particles decelerating in matter; different beta emitters have different endpoint energies; high-energy betas interacting with high-Z materials will more likely produce bremsstrahlung; depending on the data, sometimes all you can say is that a beta emitter is present.

  8. Calculation of transition probabilities using the multiconfiguration Dirac-Fock method

    International Nuclear Information System (INIS)

    Kim, Yong Ki; Desclaux, Jean Paul; Indelicato, Paul

    1998-01-01

    The performance of the multiconfiguration Dirac-Fock (MCDF) method in calculating transition probabilities of atoms is reviewed. In general, the MCDF wave functions will lead to transition probabilities accurate to ∼ 10% or better for strong, electric-dipole allowed transitions for small atoms. However, it is more difficult to get reliable transition probabilities for weak transitions. Also, some MCDF wave functions for a specific J quantum number may not reduce to the appropriate L and S quantum numbers in the nonrelativistic limit. Transition probabilities calculated from such MCDF wave functions for nonrelativistically forbidden transitions are unreliable. Remedies for such cases are discussed

  9. Atomic Transition Probabilities Scandium through Manganese

    International Nuclear Information System (INIS)

    Martin, G.A.; Fuhr, J.R.; Wiese, W.L.

    1988-01-01

    Atomic transition probabilities for about 8,800 spectral lines of five iron-group elements, Sc(Z = 21) to Mn(Z = 25), are critically compiled, based on all available literature sources. The data are presented in separate tables for each element and stage of ionization and are further subdivided into allowed (i.e., electric dipole-E1) and forbidden (magnetic dipole-M1, electric quadrupole-E2, and magnetic quadrupole-M2) transitions. Within each data table the spectral lines are grouped into multiplets, which are in turn arranged according to parent configurations, transition arrays, and ascending quantum numbers. For each line the transition probability for spontaneous emission and the line strength are given, along with the spectroscopic designation, the wavelength, the statistical weights, and the energy levels of the upper and lower states. For allowed lines the absorption oscillator strength is listed, while for forbidden transitions the type of transition is identified (M1, E2, etc.). In addition, the estimated accuracy and the source are indicated. In short introductions, which precede the tables for each ion, the main justifications for the choice of the adopted data and for the accuracy rating are discussed. A general introduction contains a discussion of our method of evaluation and the principal criteria for our judgements

  10. Mapping low- and high-density clouds in astrophysical nebulae by imaging forbidden line emission

    Science.gov (United States)

    Steiner, J. E.; Menezes, R. B.; Ricci, T. V.; Oliveira, A. S.

    2009-06-01

    Emission line ratios have been essential for determining physical parameters such as gas temperature and density in astrophysical gaseous nebulae. With the advent of panoramic spectroscopic devices, images of regions with emission lines related to these physical parameters can, in principle, also be produced. We show that, with observations from modern instruments, it is possible to transform images taken from density-sensitive forbidden lines into images of emission from high- and low-density clouds by applying a transformation matrix. In order to achieve this, images of the pairs of density-sensitive lines as well as the adjacent continuum have to be observed and combined. We have computed the critical densities for a series of pairs of lines in the infrared, optical, ultraviolet and X-rays bands, and calculated the pair line intensity ratios in the high- and low-density limit using a four- and five-level atom approximation. In order to illustrate the method, we applied it to Gemini Multi-Object Spectrograph (GMOS) Integral Field Unit (GMOS-IFU) data of two galactic nuclei. We conclude that this method provides new information of astrophysical interest, especially for mapping low- and high-density clouds; for this reason, we call it `the ld/hd imaging method'. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (United States); the Science and Technology Facilities Council (United Kingdom); the National Research Council (Canada), CONICYT (Chile); the Australian Research Council (Australia); Ministério da Ciência e Tecnologia (Brazil) and Secretaria de Ciencia y Tecnologia (Argentina). E-mail: steiner@astro.iag.usp.br

  11. Sigma beta decay

    International Nuclear Information System (INIS)

    Newman, D.E.

    1975-01-01

    Describes an experiment to measure beta decays of the sigma particle. Sigmas produced by stopping a K - beam in a liquid hydrogen target decayed in the following reactions: Kp → Σπ; Σ → Neν. The electron and pion were detected by wire spark chambers in a magnetic spectrometer and by plastic scintillators, and were differentiated by a threshold gas Cherenkov counter. The neutron was detected by liquid scintillation counters. The data (n = 3) shell electrons or the highly excited electrons decay first. Instead, it is suggested that when there are two to five electrons in highly excited states immediately after a heavy ion--atom collision the first transitions to occur will be among highly excited Rydberg states in a cascade down to the 4s, 4p, and 3d-subshells. If one of the long lived states becomes occupied by electrons promoted during the collision or by electrons falling from higher levels, it will not decay until after the valence shell decays. LMM rates calculated to test the methods used are compared to previous works. The mixing coefficients are given in terms of the states 4s4p, 45sp+-, and 5s5p. The applicability of Cooper, Fano, and Prats' discussion of the energies and transition rates of doubly excited states is considered

  12. Beta-spectroscopy of long lived nuclides with a PIPS detector-setup

    Directory of Open Access Journals (Sweden)

    Domula Alexander R.

    2017-01-01

    Full Text Available Several applications in modern nuclear physics, research and engineering are limited by a lack of precise knowledge in spectral shape data for beta-decays. Specifically the interest aims to study spectral data for forbidden decays with respectively long half-lives, which is one of the central activities of our group. For the investigation of those rare beta-decays the group operates a setup of six PIPS detectors in a vacuum chamber built out of low-radioactivity materials. In the long term the setup will be used as low-background-detector for the investigation of rare beta-decays. In order to reduce the measuring-background a muon veto was installed. The characterization of the setup in the energy-range from 20..1000 keV using conversion-electrons is described. A set of useful calibration-nuclides was established to determine energy calibration and efficiencies.

  13. The Importance of REST for Development and Function of Beta Cells

    DEFF Research Database (Denmark)

    Martin, David; Grapin-Botton, Anne

    2017-01-01

    that are crucial for both neuronal and pancreatic endocrine function, through the recruitment of multiple transcriptional and epigenetic co-regulators. REST targets include genes encoding transcription factors, proteins involved in exocytosis, synaptic transmission or ion channeling, and non-coding RNAs. REST......Beta cells are defined by the genes they express, many of which are specific to this cell type, and ensure a specific set of functions. Beta cells are also defined by a set of genes they should not express (in order to function properly), and these genes have been called forbidden genes. Among...... these, the transcriptional repressor RE-1 Silencing Transcription factor (REST) is expressed in most cells of the body, excluding most populations of neurons, as well as pancreatic beta and alpha cells. In the cell types where it is expressed, REST represses the expression of hundreds of genes...

  14. Hanle-Zeeman Scattering Matrix for Magnetic Dipole Transitions

    Energy Technology Data Exchange (ETDEWEB)

    Megha, A.; Sampoorna, M.; Nagendra, K. N.; Sankarasubramanian, K., E-mail: megha@iiap.res.in, E-mail: sampoorna@iiap.res.in, E-mail: knn@iiap.res.in, E-mail: sankar@iiap.res.in [Indian Institute of Astrophysics, Koramangala, Bengaluru 560 034 (India)

    2017-06-01

    The polarization of the light that is scattered by the coronal ions is influenced by the anisotropic illumination from the photosphere and the magnetic field structuring in the solar corona. The properties of the coronal magnetic fields can be well studied by understanding the polarization properties of coronal forbidden emission lines that arise from magnetic dipole ( M 1) transitions in the highly ionized atoms that are present in the corona. We present the classical scattering theory of the forbidden lines for a more general case of arbitrary-strength magnetic fields. We derive the scattering matrix for M 1 transitions using the classical magnetic dipole model of Casini and Lin and applying the scattering matrix approach of Stenflo. We consider a two-level atom model and neglect collisional effects. The scattering matrix so derived is used to study the Stokes profiles formed in coronal conditions in those regions where the radiative excitations dominate collisional excitations. To this end, we take into account the integration over a cone of an unpolarized radiation from the solar disk incident on the scattering atoms. Furthermore, we also integrate along the line of sight to calculate the emerging polarized line profiles. We consider radial and dipole magnetic field configurations and spherically symmetric density distributions. For our studies we adopt the atomic parameters corresponding to the [Fe xiii] 10747 Å coronal forbidden line. We also discuss the nature of the scattering matrix for M 1 transitions and compare it with that for the electric dipole ( E 1) transitions.

  15. Forbidden energy band gap in diluted a-Ge1−xSix:N films

    International Nuclear Information System (INIS)

    Guarneros, C.; Rebollo-Plata, B.; Lozada-Morales, R.; Espinosa-Rosales, J.E.; Portillo-Moreno, J.; Zelaya-Angel, O.

    2012-01-01

    By means of electron gun evaporation Ge 1−x Si x :N thin films, in the entire range 0 ≤ x ≤ 1, were prepared on Si (100) and glass substrates. The initial vacuum reached was 6.6 × 10 −4 Pa, then a pressure of 2.7 × 10 −2 Pa of high purity N 2 was introduced into the chamber. The deposition time was 4 min. Crucible-substrate distance was 18 cm. X-ray diffraction patterns indicate that all the films were amorphous (a-Ge 1−x Si x :N). The nitrogen concentration was of the order of 1 at% for all the films. From optical absorption spectra data and by using the Tauc method the energy band gap (E g ) was calculated. The Raman spectra only reveal the presence of Si-Si, Ge-Ge, and Si-Ge bonds. Nevertheless, infrared spectra demonstrate the existence of Si-N and Ge-N bonds. The forbidden energy band gap (E g ) as a function of x in the entire range 0 ≤ x ≤ 1 shows two well defined regions: 0 ≤ x ≤ 0.67 and 0.67 ≤ x ≤ 1, due to two different behaviors of the band gap, where for x > 0.67 exists an abruptly change of E g (x). In this case E g (x) versus x is different to the variation of E g in a-Ge 1−x Si x and a-Ge 1−x Si x :H. This fact can be related to the formation of Ge 3 N 4 and GeSi 2 N 4 when x ≤ 0.67, and to the formation of Si 3 N 4 and GeSi 2 N 4 for 0.67 ≤ x. - Highlights: ► Nitrogen doped amorphous Ge 1-x Si x thin films are grown by electron gun technique. ► Nitrogen atoms on E g of the a-Ge 1-x Si x films in the 0 £ x £ 1 range are analyzed. ► Variation in 0 £ x £ 1 range shows a warped change of E g in 1.0 – 3.6 eV range. ► The change in E g (x) behavior when x ∼ 0.67 was associated with Ge 2 SiN 4 presence.

  16. BetaShape: A new code for improved analytical calculations of beta spectra

    Directory of Open Access Journals (Sweden)

    Mougeot Xavier

    2017-01-01

    Full Text Available The new code BetaShape has been developed in order to improve the nuclear data related to beta decays. An analytical model was considered, except for the relativistic electron wave functions, for ensuring fast calculations. Output quantities are mean energies, log ft values and beta and neutrino spectra for single and multiple transitions. The uncertainties from the input parameters, read from an ENSDF file, are propagated. A database of experimental shape factors is included. A comparison over the entire ENSDF database with the standard code currently used in nuclear data evaluations shows consistent results for the vast majority of the transitions and highlights the improvements that can be expected with the use of BetaShape.

  17. Response gene to complement-32 enhances metastatic phenotype by mediating transforming growth factor beta-induced epithelial-mesenchymal transition in human pancreatic cancer cell line BxPC-3

    Directory of Open Access Journals (Sweden)

    Zhu Liang

    2012-03-01

    Full Text Available Abstract Background Response gene to complement-32 (RGC-32 is comprehensively expressed in many kinds of tissues and has been reported to be expressed abnormally in different kinds of human tumors. However, the role of RGC-32 in cancer remains controversial and no reports have described the effect of RGC-32 in pancreatic cancer. The present study investigated the expression of RGC-32 in pancreatic cancer tissues and explored the role of RGC-32 in transforming growth factor-beta (TGF-β-induced epithelial-mesenchymal transition (EMT in human pancreatic cancer cell line BxPC-3. Methods Immunohistochemical staining of RGC-32 and E-cadherin was performed on specimens from 42 patients with pancreatic cancer, 12 with chronic pancreatitis and 8 with normal pancreas. To evaluate the role of RGC-32 in TGF-β-induced EMT in pancreatic cancer cells, BxPC-3 cells were treated with TGF-β1, and RGC-32 siRNA silencing and gene overexpression were performed as well. The mRNA expression and protein expression of RGC-32 and EMT markers such E-cadherin and vimentin were determined by quantitative reverse transcription-PCR (qRT-PCR and western blot respectively. Finally, migration ability of BxPC-3 cells treated with TGF-β and RGC-32 siRNA transfection was examined by transwell cell migration assay. Results We found stronger expression of RGC-32 and higher abnormal expression rate of E-cadherin in pancreatic cancer tissues than those in chronic pancreatitis tissues and normal pancreatic tissues. Immunohistochemical analysis revealed that both RGC-32 positive expression and E-cadherin abnormal expression in pancreatic cancer were correlated with lymph node metastasis and TNM staging. In addition, a significant and positive correlation was found between positive expression of RGC-32 and abnormal expression of E-cadherin. Furthermore, in vitro, we found sustained TGF-β stimuli induced EMT and up-regulated RGC-32 expression in BxPC-3 cells. By means of si

  18. Structural transitions in superionic conductors

    Energy Technology Data Exchange (ETDEWEB)

    Parrinello, M.; Rahman, A.; Vashishta, P.

    1983-04-04

    The ..cap alpha..arrow-right-left..beta.. phase transition in AgI is studied with use of the new molecular-dynamics technique which allows for a dynamical variation of the shape and size of the cell. In the present model, upon heating of ..beta..-AgI, the iodine ions undergo a hcp..-->..bcc transformation and silver ions become mobile, whereas the reverse transformation is observed on cooling of ..cap alpha..-AgI. The calculated ..cap alpha..arrow-right-left..beta.. transition temperature and structural and dynamical properties are in good agreement with experiments.

  19. Levered and unlevered Beta

    OpenAIRE

    Fernandez, Pablo

    2003-01-01

    We prove that in a world without leverage cost the relationship between the levered beta ( L) and the unlevered beta ( u) is the No-costs-of-leverage formula: L = u + ( u - d) D (1 - T) / E. We also analyze 6 alternative valuation theories proposed in the literature to estimate the relationship between the levered beta and the unlevered beta (Harris and Pringle (1985), Modigliani and Miller (1963), Damodaran (1994), Myers (1974), Miles and Ezzell (1980), and practitioners) and prove that all ...

  20. MetroBeta: Beta Spectrometry with Metallic Magnetic Calorimeters in the Framework of the European Program of Ionizing Radiation Metrology

    Science.gov (United States)

    Loidl, M.; Beyer, J.; Bockhorn, L.; Enss, C.; Györi, D.; Kempf, S.; Kossert, K.; Mariam, R.; Nähle, O.; Paulsen, M.; Rodrigues, M.; Schmidt, M.

    2018-05-01

    MetroBeta is a European project aiming at the improvement of the knowledge of the shapes of beta spectra, both in terms of theoretical calculations and measurements. It is part of a common European program of ionizing radiation metrology. Metallic magnetic calorimeters (MMCs) with the beta emitter embedded in the absorber have in the past proven to be among the best beta spectrometers, in particular for low-energy beta transitions. Within this project, new designs of MMCs optimized for five different beta energy ranges were developed. A new detector module with thermal decoupling of MMC and SQUID chips was designed. An important aspect of the research and development concerns the source/absorber preparation techniques. Four beta spectra with maximum energies ranging from 76 to 709 keV will be measured. Improved theoretical calculation methods and complementary measurement techniques complete the project.

  1. Beta Thalassemia (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Beta Thalassemia KidsHealth / For Parents / Beta Thalassemia What's in this ... Symptoms Diagnosis Treatment Print en español Beta talasemia Thalassemias Thalassemias are a group of blood disorders that ...

  2. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward......-looking. This paper introduces a radically different approach to estimating market betas. Using the tools in Bakshi and Madan (2000) and Bakshi, Kapadia and Madan (2003) we employ the information embedded in the prices of individual stock options and index options to compute our forward-looking market beta...

  3. Optical Dark-Field and Electron Energy Loss Imaging and Spectroscopy of Symmetry-Forbidden Modes in Loaded Nanogap Antennas.

    Science.gov (United States)

    Brintlinger, Todd; Herzing, Andrew A; Long, James P; Vurgaftman, Igor; Stroud, Rhonda; Simpkins, B S

    2015-06-23

    We have produced large numbers of hybrid metal-semiconductor nanogap antennas using a scalable electrochemical approach and systematically characterized the spectral and spatial character of their plasmonic modes with optical dark-field scattering, electron energy loss spectroscopy with principal component analysis, and full wave simulations. The coordination of these techniques reveal that these nanostructures support degenerate transverse modes which split due to substrate interactions, a longitudinal mode which scales with antenna length, and a symmetry-forbidden gap-localized transverse mode. This gap-localized transverse mode arises from mode splitting of transverse resonances supported on both antenna arms and is confined to the gap load enabling (i) delivery of substantial energy to the gap material and (ii) the possibility of tuning the antenna resonance via active modulation of the gap material's optical properties. The resonant position of this symmetry-forbidden mode is sensitive to gap size, dielectric strength of the gap material, and is highly suppressed in air-gapped structures which may explain its absence from the literature to date. Understanding the complex modal structure supported on hybrid nanosystems is necessary to enable the multifunctional components many seek.

  4. Dose point kernels for beta-emitting radioisotopes

    International Nuclear Information System (INIS)

    Prestwich, W.V.; Chan, L.B.; Kwok, C.S.; Wilson, B.

    1986-01-01

    Knowledge of the dose point kernel corresponding to a specific radionuclide is required to calculate the spatial dose distribution produced in a homogeneous medium by a distributed source. Dose point kernels for commonly used radionuclides have been calculated previously using as a basis monoenergetic dose point kernels derived by numerical integration of a model transport equation. The treatment neglects fluctuations in energy deposition, an effect which has been later incorporated in dose point kernels calculated using Monte Carlo methods. This work describes new calculations of dose point kernels using the Monte Carlo results as a basis. An analytic representation of the monoenergetic dose point kernels has been developed. This provides a convenient method both for calculating the dose point kernel associated with a given beta spectrum and for incorporating the effect of internal conversion. An algebraic expression for allowed beta spectra has been accomplished through an extension of the Bethe-Bacher approximation, and tested against the exact expression. Simplified expression for first-forbidden shape factors have also been developed. A comparison of the calculated dose point kernel for 32 P with experimental data indicates good agreement with a significant improvement over the earlier results in this respect. An analytic representation of the dose point kernel associated with the spectrum of a single beta group has been formulated. 9 references, 16 figures, 3 tables

  5. Study and construction of a {beta}-spectrometer of uniform axial magnetic field fitted with a {beta}-{gamma} coincidence selector. Study of the {beta} spectra of {sup 32}P, {sup 203}Hg, {sup 198}Au. Measurement of the conversion coefficients of {sup 203}Ti and of {sup 198}Hg; Etude et realisation d'un spectrometre-{beta} a champ magnetique axial uniforme, muni d'un selecteur de coincidence {beta}-{gamma}. Etude des spectres {beta} du {sup 32}p, {sup 203}Hg, {sup 198}Au. Mesure des coefficients de conversion du {sup 203}Ti et du {sup 198}Hg

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-06-01

    In the first part is given the principle of the beta spectrometer with uniform axial field using systematically the idea of caustics. The apparatus is described and its properties compared to those deduced from trajectory calculations. The {beta}-ray and {gamma}-ray detectors and the device for selecting coincidences with a 2 {tau} resolution of 5 nanoseconds are also presented. In the second part, the spectrometer is used for studying reference elements and the most accurate results are confirmed. The {beta} spectrum of {sup 60}Co has a statistical form with an accuracy of 1 per cent; the maximum energy E{sub 0} is 316.5 {+-} 1.5 keV. That of the 7/2 + {yields} 11/2 transition for {sup 137}Cs has a unique form, once forbidden. E{sub 0}= 522 {+-} 3 keV. Conversion coefficients {alpha}{sub k} = 96 {+-} 1 X 10{sup -3} {alpha}L + M + N = 20.9 {+-} 0.5 X 10{sup -3}. The two {beta} spectra of {sup 59}Fe, separated by coincidence with the gamma, have the statistical form E{sub 0} = 462 {+-} 2 keV (55.1 + 0,3 per cent) and E{sub 1} = 275 {+-} 4 keV (44.9 {+-} 0.3 per cent). It is then verified whether the l selection rule is apparent in the shape of the phosphorus 32 beta spectrum. It is found in fact that it is not of statistical shape and its shape coefficient is determined. For a theoretical interpretation it is necessary to have better approximations than those generally used and this interpretation will not be unique. This work has also made it possible to show that the source contains a small proportion of {sup 33}P. The study of the {sup 203}Hg {beta} spectrum followed by the 279 keV gamma spectrum is designed to determine the conversion coefficients. The interior spectrum of gold 198 is not of statistical shape either. The form coefficient is determined together with the conversion coefficients which are in slight disagreement with those calculated by Rose or Sliv. An interpretation of the spectrum is put forward which proposes an imperfect compensation for the

  6. Study and construction of a {beta}-spectrometer of uniform axial magnetic field fitted with a {beta}-{gamma} coincidence selector. Study of the {beta} spectra of {sup 32}P, {sup 203}Hg, {sup 198}Au. Measurement of the conversion coefficients of {sup 203}Ti and of {sup 198}Hg; Etude et realisation d'un spectrometre-{beta} a champ magnetique axial uniforme, muni d'un selecteur de coincidence {beta}-{gamma}. Etude des spectres {beta} du {sup 32}p, {sup 203}Hg, {sup 198}Au. Mesure des coefficients de conversion du {sup 203}Ti et du {sup 198}Hg

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-06-01

    In the first part is given the principle of the beta spectrometer with uniform axial field using systematically the idea of caustics. The apparatus is described and its properties compared to those deduced from trajectory calculations. The {beta}-ray and {gamma}-ray detectors and the device for selecting coincidences with a 2 {tau} resolution of 5 nanoseconds are also presented. In the second part, the spectrometer is used for studying reference elements and the most accurate results are confirmed. The {beta} spectrum of {sup 60}Co has a statistical form with an accuracy of 1 per cent; the maximum energy E{sub 0} is 316.5 {+-} 1.5 keV. That of the 7/2 + {yields} 11/2 transition for {sup 137}Cs has a unique form, once forbidden. E{sub 0}= 522 {+-} 3 keV. Conversion coefficients {alpha}{sub k} = 96 {+-} 1 X 10{sup -3} {alpha}L + M + N = 20.9 {+-} 0.5 X 10{sup -3}. The two {beta} spectra of {sup 59}Fe, separated by coincidence with the gamma, have the statistical form E{sub 0} = 462 {+-} 2 keV (55.1 + 0,3 per cent) and E{sub 1} = 275 {+-} 4 keV (44.9 {+-} 0.3 per cent). It is then verified whether the l selection rule is apparent in the shape of the phosphorus 32 beta spectrum. It is found in fact that it is not of statistical shape and its shape coefficient is determined. For a theoretical interpretation it is necessary to have better approximations than those generally used and this interpretation will not be unique. This work has also made it possible to show that the source contains a small proportion of {sup 33}P. The study of the {sup 203}Hg {beta} spectrum followed by the 279 keV gamma spectrum is designed to determine the conversion coefficients. The interior spectrum of gold 198 is not of statistical shape either. The form coefficient is determined together with the conversion coefficients which are in slight disagreement with those calculated by Rose or Sliv. An interpretation of the spectrum is put forward which proposes an imperfect compensation for the

  7. Interband transitions in 106Pd, 152Sm, 152Gd and 182W

    International Nuclear Information System (INIS)

    Kartashov, V.M.; Oborovskij, A.I.; Troitskaya, A.G.

    1990-01-01

    Internal transitions in 106 Pd, 152 Sm, 152 Gd, 182 W nuclei, observed during decay of 152,152m Eu, 182,183 Ta, 106m Ag, are studied. The experimental characteristics of E0-transitions and E0-components of E0+M1+E2 type transitions in the studied nuclei, relative intensities of internal conversion electron lines during 182 Ta decay, multipolar composition and forbidden factor for 182 W and 183 W low-energy transitions, characteristics of transitions are presented

  8. The nature of the emission transition of the octahedral uranate group, ch. 5

    International Nuclear Information System (INIS)

    Hair, J.Th.W. de

    1976-01-01

    Decay times of the green luminescence of U 6+ in oxides with perovskite structure are reported. The influence of the site symmetry is found to be considerable. The temperature dependence of the decay time gives evidence for a coupling of the electronic transition with a phonon of about 200 cm -1 in the excited state. The results show the emission to originate from a parity forbidden transition, vibronically allowed by coupling with vibrations of ungerade symmetry. (Auth.)

  9. Weak interaction studies from nuclear beta decay

    International Nuclear Information System (INIS)

    Morita, M.

    1981-01-01

    The studies performed at the theoretical nuclear physics division of the Laboratory of Nuclear Studies, Osaka University, are reported. Electron spin density and internal conversion process, nuclear excitation by electron transition, beta decay, weak charged current, and beta-ray angular distributions in oriented nuclei have been studied. The relative intensity of internal conversion electrons for the case in which the radial wave functions of orbital electrons are different for electron spin up and down was calculated. The calculated value was in good agreement with the experimental one. The nuclear excitation following the transition of orbital electrons was studied. The calculated probability of the nuclear excitation of Os 189 was 1.4 x 10 - 7 in conformity with the experimental value 1.7 x 10 - 7 . The second class current and other problems on beta-decay have been extensively studied, and described elsewhere. Concerning weak charged current, the effects of all induced terms, the time component of main axial vector, all partial waves of leptons, Coulomb correction for the electrons in finite size nuclei, and radiative correction were studied. The beta-ray angular distribution for the 1 + -- 0 + transition in oriented B 12 and N 12 was investigated. In this connection, investigation on the weak magnetism to include all higher order corrections for the evaluation of the spectral shape factors was performed. Other works carried out by the author and his collaborators are also explained. (Kato, T.)

  10. Spectroscopically forbidden infra-red emission in Au-vertical graphene hybrid nanostructures

    Science.gov (United States)

    Sivadasan, A. K.; Parida, Santanu; Ghosh, Subrata; Pandian, Ramanathaswamy; Dhara, Sandip

    2017-11-01

    Implementation of Au nanoparticles (NPs) is a subject for frontier plasmonic research due to its fascinating optical properties. Herein, the present study deals with plasmonic assisted emission properties of Au NPs-vertical graphene (VG) hybrid nanostructures. The influence of effective polarizability of Au NPs on the surface enhanced Raman scattering and luminescence properties is investigated. In addition, a remarkable infra-red emission in the hybrid nanostructures is observed and interpreted on the basis of intra-band transitions in Au NPs. The flake-like nanoporous VG structure is invoked for the generation of additional confined photons to impart additional momentum and a gradient of confined excitation energy towards initiating the intra-band transitions of Au NPs. Integrating Au plasmonic materials in three-dimensional VG nanostructures enhances the light-matter interactions. The present study provides a new adaptable plasmonic assisted pathway for optoelectronic and sensing applications.

  11. Betting Against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model’s five central predictions: (1) Since constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for U...... of the BAB factor is low; (4) Increased funding liquidity risk compresses betas toward one; (5) More constrained investors hold riskier assets........S. equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures; (2) A betting-against-beta (BAB) factor, which is long leveraged low beta assets and short high-beta assets, produces significant positive risk-adjusted returns; (3) When funding constraints tighten, the return...

  12. Roughing up Beta

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Li, Sophia Zhengzi; Todorov, Viktor

    -section. An investment strategy that goes long stocks with high jump betas and short stocks with low jump betas produces significant average excess returns. These higher risk premiums for the discontinuous and overnight market betas remain significant after controlling for a long list of other firm characteristics......Motivated by the implications from a stylized equilibrium pricing framework, we investigate empirically how individual equity prices respond to continuous, or \\smooth," and jumpy, or \\rough," market price moves, and how these different market price risks, or betas, are priced in the cross......-section of expected returns. Based on a novel highfrequency dataset of almost one-thousand individual stocks over two decades, we find that the two rough betas associated with intraday discontinuous and overnight returns entail significant risk premiums, while the intraday continuous beta is not priced in the cross...

  13. Majorana neutrinos and double beta-decay

    International Nuclear Information System (INIS)

    Shchepkin, M.G.

    1986-01-01

    Problem, related to neutrino mass and lepton charge L conservation is briefly discussed. A possibility to experimentally test L conservation in different processes and to produce limitations for neutrino mass in double beta-decay processes is considered. Planned experiments on studying the double neutrinoless (2β) beta-decays and searching 2β(2ν)-decays, permitted by the conservation laws, are discussed. It is stressed, that comparison of the existing theoretical predictions of 2β(2ν)-decay probability with experimental results will make it possible to choose the most adequate approach to the calculation of double β-transition nuclear amplitudes

  14. Precision measurements in nuclear beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Naviliat-Cuncic, Oscar, E-mail: naviliat@nscl.msu.edu [Michigan State University, National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy (United States)

    2013-03-15

    Precision measurements in nuclear beta decay provide sensitive means to determine the fundamental coupling of charged fermions to weak bosons and to test discrete symmetries in the weak interaction. The main motivation of such measurements is to find deviations from Standard Model predictions as possible indications of new physics. I focus here on two topics related to precision measurements in beta decay, namely: (i) the determination of the V{sub ud} element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix from nuclear mirror transitions and (ii) selected measurements of time reversal violating correlations in nuclear and neutron decays. These topics complement those presented in other contributions to this conference.

  15. Beta limits for ETF

    International Nuclear Information System (INIS)

    Helton, F.J.; Miller, R.L.

    1982-01-01

    ETF (Engineering Test Facility) one-dimensional transport simulations indicate that a volume-average beta of 4% is required for ignition. It is therefore important that theoretical beta limits, determined by requiring equilibria to be stable to all ideal modes, exceed 4%. This paper documents an ideal MHD analysis wherein it is shown that, with appropriate plasma cross-sectional shape and current profile optimization, operation near 5% is possible. The critical beta value, however, depends on the functional form used for ff', which suggests that higher critical betas could be achieved by directly optimizing the safety factor profile. (author)

  16. Beta-energy averaging and beta spectra

    International Nuclear Information System (INIS)

    Stamatelatos, M.G.; England, T.R.

    1976-07-01

    A simple yet highly accurate method for approximately calculating spectrum-averaged beta energies and beta spectra for radioactive nuclei is presented. This method should prove useful for users who wish to obtain accurate answers without complicated calculations of Fermi functions, complex gamma functions, and time-consuming numerical integrations as required by the more exact theoretical expressions. Therefore, this method should be a good time-saving alternative for investigators who need to make calculations involving large numbers of nuclei (e.g., fission products) as well as for occasional users interested in restricted number of nuclides. The average beta-energy values calculated by this method differ from those calculated by ''exact'' methods by no more than 1 percent for nuclides with atomic numbers in the 20 to 100 range and which emit betas of energies up to approximately 8 MeV. These include all fission products and the actinides. The beta-energy spectra calculated by the present method are also of the same quality

  17. Allowed unhindered beta connected states in rare earth nuclei

    International Nuclear Information System (INIS)

    Sood, P.C.; Ray, R.S.

    1986-03-01

    The beta-connected states in odd-mass as well as even mass rare earth nuclei, where the transition is of allowed unhindered nature, are listed. The tabulation includes 54 cases of such transitions. Validity of Alaga selection rules is examined and the results are used to assign configurations to the involved single particle and two-particle states. (author)

  18. Les dépenses interdites des collectivités locales The Forbidden Expenses of Local Entities

    Directory of Open Access Journals (Sweden)

    Jean-François Boudet

    2009-09-01

    Full Text Available Les différentes réformes dites de « décentralisation » entreprises en France notamment depuis 1982 laisseraient entendre que les collectivités locales ont toute latitude dans la gestion de leurs compétences et de leurs finances. Il n’en rien, car, au-delà de dépenses obligatoires, les collectivités locales se voient interdire certaines dépenses. Le caractère unitaire de l’Etat expliquerait cette interdiction.In France, since 1982, the so-called “decentralisation” reforms would imply that local governments are independent with regard to the management of their resources and budget. This is not the case: aside from mandatory expenses, a few expenditures are forbidden to local governments. The unitary character of the State would explain this interdiction.

  19. Energy position of bistable defect (CiCs)0 in 'B' configuration in a forbidden zone of n-Si

    International Nuclear Information System (INIS)

    Dolgolenko, A.P.; Litovchenko, P.G.; Varentsov, M.D.

    2003-01-01

    Float-zone and phosphorus-doped n-Si samples after irradiation by fast-pile neutrons and subsequent annealing at room temperature were investigated. The calculation of effective concentration of carriers after irradiation was carried out in the framework of Gossick's model taking into account the recharges of defects both in conducting matrix of n-Si and in the space-charge region of defect clusters. The distribution function of electrons on the acceptor level of bistable defect (C i C s ) 0 when the concentration of this defect is the function of the Fermi level in conducting matrix of n-Si is determined. The concentration of bistable interstitial-carbon-substitutional-carbon pair and its energy level at (E c - 0,123 eV) in forbidden band of silicon were calculated. On the observable level of stable configuration C i C s (A - )-defects at (E c - 0,147 eV) the theoretical change of carriers concentration in the conduction band simulated by the recharges (C i C s ) 0 was imposed. The concentration of these (C i C s ) 0 -defects has been changed in the process of their recharges. It is shown that in n-Si with high carbon and oxygen concentration after affiliating of oxygen atoms to bistable defect (C i C s ) 0 in a forbidden band of n-Si the stable defects not only in 'A' but also in 'B' configurations are formed with energy levels at (E c - 0,13 eV) and (E c - 0,09 eV)

  20. Identification of forbidden lines in the soft X-ray spectrum of the TFR Tokamak

    International Nuclear Information System (INIS)

    Klapisch, M.; Schwob, J.L.; Finkenthal, M.; Fraenkel, B.S.; Egert, S.; Bar-Shalom, A.; Breton, C.; Michelis, C. de; Mattioli, M.

    1978-01-01

    Two quite intense lines, at 58.832 A and 57.927 A appearing in the TFR Tokamak are attributed to E2 transitions 3d 10 - 3d 9 4s (J=2) of MoXV. This classification is based on the comparison between experimental and computed wavelengths and intensities of these lines in the Tokamak plasma. The great influence of cascades on the intensities is shown. It is shown that similar lines for other ionization stages of Mo should be much weaker

  1. Thinking Forbidden Thoughts: The Oedipus Complex as a Complex of Knowing.

    Science.gov (United States)

    Schein, Michael

    2016-04-01

    The Oedipus complex, considered by Freud the "nuclear complex of development," played a central role in the evolution of psychoanalytic thought. This paper returns to the point of transition from the seduction theory, Freud's initial theorem, to the oedipal model, and suggests that the Oedipus complex is first and foremost a text and as such contains a multiplicity of narratives. In particular, the author articulates the close relation between the Oedipus complex and the subject of knowing, postulating that underlying its surface level, the deep-level structure of this complex is one of knowing. As a complex of knowing it is of dual quality, both promoting and impeding the ability to know.

  2. High beta tokamaks

    International Nuclear Information System (INIS)

    Dory, R.A.; Berger, D.P.; Charlton, L.A.; Hogan, J.T.; Munro, J.K.; Nelson, D.B.; Peng, Y.K.M.; Sigmar, D.J.; Strickler, D.J.

    1978-01-01

    MHD equilibrium, stability, and transport calculations are made to study the accessibility and behavior of ''high beta'' tokamak plasmas in the range β approximately 5 to 15 percent. For next generation devices, beta values of at least 8 percent appear to be accessible and stable if there is a conducting surface nearby

  3. Sorting out Downside Beta

    NARCIS (Netherlands)

    G.T. Post (Thierry); P. van Vliet (Pim); S.D. Lansdorp (Simon)

    2009-01-01

    textabstractDownside risk, when properly defined and estimated, helps to explain the cross-section of US stock returns. Sorting stocks by a proper estimate of downside market beta leads to a substantially larger cross-sectional spread in average returns than sorting on regular market beta. This

  4. Betting against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    2014-01-01

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model's five central predictions: (1) Because constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically...

  5. Genetics Home Reference: beta thalassemia

    Science.gov (United States)

    ... Facebook Twitter Home Health Conditions Beta thalassemia Beta thalassemia Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Beta thalassemia is a blood disorder that reduces the production ...

  6. Rapid synthesis of beta zeolites

    Science.gov (United States)

    Fan, Wei; Chang, Chun -Chih; Dornath, Paul; Wang, Zhuopeng

    2015-08-18

    The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.

  7. Tables of double beta decay data

    International Nuclear Information System (INIS)

    Tretyak, V.I.

    1995-01-01

    A compilation of experimental data on double beta decay is presented. The tables contain the most stringent known experimental limits or positive results of 2β transitions of 69 natural nuclides to ground and excited states of daughter nuclei for different channels (2β - ; 2β + ; εβ + ; 2ε) and modes (0ν; 2ν; 0νM) of decay. (authors). 189 refs., 9 figs., 3 tabs

  8. Beta particle measurement fundamentals

    International Nuclear Information System (INIS)

    Alvarez, J.L.

    1986-01-01

    The necessary concepts for understanding beta particle behavior are stopping power, range, and scattering. Dose as a consequence of beta particle interaction with tissue can be derived and explained by these concepts. Any calculations of dose, however, assume or require detailed knowledge of the beta spectrum at the tissue depth of calculation. A rudimentary knowledge of the incident spectrum can be of use in estimating dose, interpretating dose measuring devices and designing protection. The stopping power and range based on the csda will give a conservative estimate in cases of protection design, as scattering will reduce the range. Estimates of dose may be low because scattering effects were neglected

  9. $\\beta$ decay of $^{47}$Ar

    CERN Document Server

    Weissman, L; Bergmann, U C; Brown, B A; Catherall, R; Cederkäll, J; Dillmann, I; Hallmann, O; Fraile-Prieto, L M; Franchoo, S; Gaudefroy, L; Köster, U; Kratz, K L; Pfeiffer, B; Sorlin, O; 10.1103/PhysRevC.70.024304

    2004-01-01

    Information on beta -decay properties of neutron-rich /sup 47/Ar was obtained at the ISOLDE facility at CERN using isobaric selectivity. This was achieved by a combination of a plasma-ion source with a cooled transfer line and subsequent mass separation. A doubly charged beam was used in order to improve the signal-to-background ratio associated with multi-charged noble gas fission products. The identification of the /sup 47/Ar gamma -ray transitions was performed by comparing the spectra obtained from direct proton bombardment of the target and of the neutron converter. New excited levels in the daughter /sup 47/K nucleus corresponding to the negative-parity states were observed. The obtained data are compared to the result of large-scale shell model calculations and quasiparticle random-phase approximation predictions. (29 refs).

  10. Vibrational circular dichroism spectroscopy of a spin-triplet bis-(biuretato) cobaltate(III) coordination compound with low-lying electronic transitions

    DEFF Research Database (Denmark)

    Johannessen, Christian; Thulstrup, Peter W.

    2007-01-01

    . The spectroscopic results were compared to measurements performed on the free ligand and to theoretical calculations using density functional theory (B3LYP/TZVP). The results of the VCD analysis of the coordination compound identified an electronic, dipole-forbidden, magnetic dipole-allowed low-lying d-d transition...

  11. On the nuclear double beta decay: microscopic description

    International Nuclear Information System (INIS)

    Civitarese, Osvaldo

    1989-01-01

    This paper is devoted to the discussion of some problems related with microscopic descriptions of the nuclear double beta decay. It has been organized in the following order: 1) Review of the experimental situation; 2) Brief discussion of the theoretical aspects related to the current algebra, weak interaction, neutrino and majoron's status and 3) Elements of the standard nuclear theory involved in the calculation of transition densities for the nuclear double beta decay. (Author) [es

  12. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2012-10-06

    Oct 6, 2012 ... Anyhow, the 'multi-isotope' ansatz is needed to compensate for matrix element ... The neccessary half-life requirement to touch this ... site energy depositions (like double beta decay) and multiple site interactions (most of.

  13. Beta-Carotene

    Science.gov (United States)

    ... disease (COPD). It is also used to improve memory and muscle strength. Some people use beta-carotene ... to reduce the chance of death and night blindness during pregnancy, as well as diarrhea and fever ...

  14. Double beta decay: experiments

    International Nuclear Information System (INIS)

    Fiorini, Ettore

    2006-01-01

    The results obtained so far and those of the running experiments on neutrinoless double beta decay are reviewed. The plans for second generation experiments, the techniques to be adopted and the expected sensitivities are compared and discussed

  15. Thermoreflectance characterization of beta-Ga2O3 thin-film nanostrips.

    Science.gov (United States)

    Ho, Ching-Hwa; Tseng, Chiao-Yeh; Tien, Li-Chia

    2010-08-02

    Nanostructure of beta-Ga(2)O(3) is wide-band-gap material with white-light-emission function because of its abundance in gap states. In this study, the gap states and near-band-edge transitions in beta-Ga(2)O(3) nanostrips have been characterized using temperature-dependent thermoreflectance (TR) measurements in the temperature range between 30 and 320 K. Photoluminescence (PL) measurements were carried to identify the gap-state transitions in the beta-Ga(2)O(3) nanostrips. Experimental analysis of the TR spectra revealed that the direct gap (E(0)) of beta-Ga(2)O(3) is 4.656 eV at 300 K. There are a lot of gap-state and near-band-edge (GSNBE) transitions denoted as E(D3), E(W1), E(W2), E(W3), E(D2), EDBex, E(DB), E(D1), E(0), and E(0)' can be detected in the TR and PL spectra at 30 K. Transition origins for the GSNBE features in the beta-Ga(2)O(3) nanostrips are respectively evaluated. Temperature dependences of transition energies of the GSNBE transitions in the beta-Ga(2)O(3) nanostrips are analyzed. The probable band scheme for the GSNBE transitions in the beta-Ga(2)O(3) nanostrips is constructed.

  16. {beta} - amyloid imaging probes

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jae Min [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    Imaging distribution of {beta} - amyloid plaques in Alzheimer's disease is very important for early and accurate diagnosis. Early trial of the {beta} -amyloid plaques includes using radiolabeled peptides which can be only applied for peripheral {beta} - amyloid plaques due to limited penetration through the blood brain barrier (BBB). Congo red or Chrysamine G derivatives were labeled with Tc-99m for imaging {beta} - amyloid plaques of Alzheimer patient's brain without success due to problem with BBB penetration. Thioflavin T derivatives gave breakthrough for {beta} - amyloid imaging in vivo, and a benzothiazole derivative [C-11]6-OH-BTA-1 brought a great success. Many other benzothiazole, benzoxazole, benzofuran, imidazopyridine, and styrylbenzene derivatives have been labeled with F-18 and I-123 to improve the imaging quality. However, [C-11]6-OH-BTA-1 still remains as the best. However, short half-life of C-11 is a limitation of wide distribution of this agent. So, it is still required to develop an Tc-99m, F-18 or I-123 labeled agent for {beta} - amyloid imaging agent.

  17. Electric Monopole Transition Strengths in 62Ni

    Directory of Open Access Journals (Sweden)

    Evitts L. J.

    2016-01-01

    Full Text Available Excited states in 62Ni were populated with a (p, p’ reaction using the 14UD Pelletron accelerator at the Australian National University. Electric monopole transition strengths, ρ2(E0, were measured through simultaneous detection of the internal conversion electrons and γ rays emitted from the de-excitation of populated states, using the Super-e spectrometer coupled with a germanium detector. The strength of the 02+ to 01+ transition has been measured to be 77−34+23 × 10−3 and agrees with previously reported values. Upper limits have been placed on the 03+ to 01+ and 03+ to 02+ transitions. The measured ρ2(E0 value of the 22+ to 21+ transition in 62Ni has been measured for the first time and found to be one of the largest ρ2(E0 values measured to date in nuclei heavier than Ca. The low-lying states of 62Ni have previously been classified as one- and two-phonon vibrational states based on level energies. The measured electric quadrupole transition strengths are consistent with this interpretation. However as electric monopole transitions are forbidden between states which differ by one phonon number, the simple harmonic quadrupole vibrational picture is not suffcient to explain the large ρ2(E0 value for the 22+ to 21+ transition.

  18. Electric Monopole Transition Strengths in 62Ni

    Science.gov (United States)

    Evitts, L. J.; Garnsworthy, A. B.; Kibédi, T.; Moukaddam, M.; Alshahrani, B.; Eriksen, T. K.; Holt, J. D.; Hota, S. S.; Lane, G. J.; Lee, B. Q.; McCormick, B. P.; Palalani, N.; Reed, M. W.; Stroberg, S. R.; Stuchbery, A. E.

    2016-09-01

    Excited states in 62Ni were populated with a (p, p') reaction using the 14UD Pelletron accelerator at the Australian National University. Electric monopole transition strengths, ρ2(E0), were measured through simultaneous detection of the internal conversion electrons and γ rays emitted from the de-excitation of populated states, using the Super-e spectrometer coupled with a germanium detector. The strength of the 02+ to 01+ transition has been measured to be 77-34+23 × 10-3 and agrees with previously reported values. Upper limits have been placed on the 03+ to 01+ and 03+ to 02+ transitions. The measured ρ2(E0) value of the 22+ to 21+ transition in 62Ni has been measured for the first time and found to be one of the largest ρ2(E0) values measured to date in nuclei heavier than Ca. The low-lying states of 62Ni have previously been classified as one- and two-phonon vibrational states based on level energies. The measured electric quadrupole transition strengths are consistent with this interpretation. However as electric monopole transitions are forbidden between states which differ by one phonon number, the simple harmonic quadrupole vibrational picture is not suffcient to explain the large ρ2(E0) value for the 22+ to 21+ transition.

  19. Measurement of the spin-forbidden decay rate (3s3d)1D2¿(3s3p)3 P2,1 in 24Mg

    DEFF Research Database (Denmark)

    Therkildsen, K. T.; Jensen, Brian Bak; Ryder, C. P.

    2009-01-01

    We have measured the spin-forbidden decay rate from (3s3d)D12¿(3s3p)P32,1 in M24g atoms trapped in a magneto-optical trap. The total decay rate, summing up both exit channels (3s3p)P31 and (3s3p)P32 , yields 196±10s-1 in excellent agreement with resent relativistic many-body calculations of Porse...

  20. Boosted beta regression.

    Directory of Open Access Journals (Sweden)

    Matthias Schmid

    Full Text Available Regression analysis with a bounded outcome is a common problem in applied statistics. Typical examples include regression models for percentage outcomes and the analysis of ratings that are measured on a bounded scale. In this paper, we consider beta regression, which is a generalization of logit models to situations where the response is continuous on the interval (0,1. Consequently, beta regression is a convenient tool for analyzing percentage responses. The classical approach to fit a beta regression model is to use maximum likelihood estimation with subsequent AIC-based variable selection. As an alternative to this established - yet unstable - approach, we propose a new estimation technique called boosted beta regression. With boosted beta regression estimation and variable selection can be carried out simultaneously in a highly efficient way. Additionally, both the mean and the variance of a percentage response can be modeled using flexible nonlinear covariate effects. As a consequence, the new method accounts for common problems such as overdispersion and non-binomial variance structures.

  1. Study of coupled-cluster correlations on electromagnetic transitions and hyperfine structure constants of W VI

    International Nuclear Information System (INIS)

    Bhowmik, Anal; Majumder, Sonjoy; Roy, Sourav; Dutta, Narendra Nath

    2017-01-01

    This work presents precise calculations of important electromagnetic transition amplitudes along with details of their many-body correlations using the relativistic coupled-cluster method. Studies of hyperfine interaction constants, useful for plasma diagnostics, with this correlation exhaustive many-body approach, are another important area of this work. The calculated oscillator strengths of allowed transitions, amplitudes of forbidden transitions and lifetimes are compared with the other theoretical results wherever available and they show a good agreement. Hyperfine constants of different isotopes of W VI, presented in this paper, will be helpful in gaining an accurate picture of the abundances of this element in different astronomical bodies. (paper)

  2. Nuclear structure and double beta decay

    International Nuclear Information System (INIS)

    Vogel, P.

    1988-01-01

    Double beta decay is a rare transition between two nuclei of the same mass number A involving a change of the nuclear charge Z by two units. It has long been recognized that the Oν mode of double beta decay, where two electrons and no neutrinos are emitted, is a powerful tool for the study of neutrino properties. Its observation would constitute a convincing proof that there exists a massive Majorana neutrino which couples to electrons. Double beta decay is a process involving an intricate mixture of particle physics and physics of the nucleus. The principal nuclear physics issues have to do with the evaluation of the nuclear matrix elements responsible for the decay. If the authors wish to arrive at quantitative answers for the neutrino properties the authors have no choice but to learn first how to understand the nuclear mechanisms. The authors describe first the calculation of the decay rate of the 2ν mode of double beta decay, in which two electrons and two antineutrinos are emitted

  3. Labelling of. beta. -endorphin (. beta. -END) and. beta. -lipotropin (. beta. -LPH) by /sup 125/I

    Energy Technology Data Exchange (ETDEWEB)

    Deby-Dupont, G.; Joris, J.; Franchimont, P. (Universite de Liege (Belgique)); Reuter, A.M.; Vrindts-Gevaert, Y. (Institut des Radioelements, Fleurus (Belgique))

    1983-01-01

    5 ..mu..g of human ..beta..-endorphin were labelled with 2 mCi /sup 125/I by the chloramine T technique. After two gel filtrations on Sephadex G-15 and on Sephadex G-50 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer was obtained with a specific activity about 150 ..mu..Ci/..mu..g.Kept at + 4/sup 0/C, the tracer remained utilizable for 30 days without loss of immunoreactivity. The labelling with lactoperoxydase and the use of another gel filtration method (filtration on Aca 202) gave a /sup 125/I ..beta..-END tracer with the same immunoreactivity. The binding of this tracer to the antibody of an anti-..beta..-END antiserum diluted at 1/8000 was 32% with a non specific binding of 2%. 5 ..mu..g of human ..beta..-lipotropin were labelled with 0.5 mCi /sup 125/I by the lactoperoxydase method. After two gel filtrations on Sephadex G-25 and on Sephadex G-75 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer with a specific activity of 140 ..mu..Ci/..mu..g was obtained. It remained utilizable for 30 days when kept at + 4/sup 0/C. Gel filtration on Aca 202 did not give good purification, while gel filtration on Aca 54 was good but slower than on Sephadex G-75. The binding to antibody in absence of unlabelled ..beta..-LPH was 32% for an anti-..beta..-LPH antiserum diluted at 1/4000. The non specific binding was 2.5%.

  4. High-pressure behavior of beta-Ga2O3 nanocrystals

    DEFF Research Database (Denmark)

    Wang, H.; He, Y.; Chen, W.

    2010-01-01

    that nanocrystalline monoclinic beta-Ga2O3 underwent a phase transition to rhombohedral alpha-Ga2O3. It was found that beta- to alpha-Ga2O3 transition began at about 13.6-16.4 GPa, and extended up to 39.2 GPa. At the highest pressure used, only alpha-Ga2O3 was present, which remained after pressure release. A Birch......-Murnaghan fit to the P-V data yielded a zero-pressure bulk modulus at fixed B-0(')=4: B-0=228(9) GPa and B-0=333(19) GPa for beta-Ga2O3 and alpha-Ga2O3 phases, respectively. We compared our results with bulk beta-Ga2O3, and concluded that the phase-transition pressure and bulk modulus of nanocrystalline beta...

  5. Plasma beta HCG determination

    International Nuclear Information System (INIS)

    Amaral, L.B.D.; Pinto, J.C.M.; Linhares, E.; Linhares, Estevao

    1981-01-01

    There are three important indications for the early diagnosis of pregnancy through the determination of the beta sub-unit of chorionic gonadotrophin using radioimmunoassay: 1) some patient's or doctor's anxiety to discover the problem; 2) when it will be necessary to employ diagnostic or treatment procedures susceptible to affect the ovum; and 3) in the differential diagnosis of amenorrhoea, uterine hemorrhage and abdominal tumors. Other user's are the diagnosis of missed absortion, and the diagnosis and follow-up of chrorioncarcinoma. The AA. studied 200 determinations of plasma beta-HCG, considering the main difficulties occuring in the clinical use of this relevant laboratory tool in actual Obstetrics. (author) [pt

  6. Relation between the 2{nu}{beta}{beta} and 0{nu}{beta}{beta} nuclear matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Petr [Kellogg Radiation Laboratory, Caltech, Pasadena, CA 91125 (United States); Simkovic, Fedor [Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina F1, SK-84248 Bratislava (Slovakia)

    2011-12-16

    A formal relation between the GT part of the nuclear matrix elements M{sub GT}{sup 0{nu}} of 0{nu}{beta}{beta} decay and the closure matrix elements M{sub cl}{sup 2{nu}} of 2{nu}{beta}{beta} decay is established. This relation is based on the integral representation of these quantities in terms of their dependence on the distance r between the two nucleons undergoing transformation. We also discuss the difficulties in determining the correct values of the closure 2{nu}{beta}{beta} decay matrix elements.

  7. The Effect of the Spin-Forbidden Co((sup 1) Sigma plus) plus O((sup 3) P) Yields CO2 (1 Sigma (sub G) plus) Recombination Reaction on Afterbody Heating of Mars Entry Vehicles

    Science.gov (United States)

    Xu, Lu T.; Jaffe, Richard L.; Schwenke, David W.; Panesi, Marco

    2017-01-01

    Vibrationally excited CO2, formed by two-body recombination from CO((sup 1) sigma plus) and O((sup 3) P) in the wake behind spacecraft entering the Martian atmosphere reaction, is potentially responsible for the higher than anticipated radiative heating of the backshell, compared to pre-flight predictions. This process involves a spin-forbidden transition of the transient triplet CO2 molecule to the longer-lived singlet. To accurately predict the singlet-triplet transition probability and estimate the thermal rate coefficient of the recombination reaction, ab initio methods were used to compute the first singlet and three lowest triplet CO2 potential energy surfaces and the spin-orbit coupling matrix elements between these states. Analytical fits to these four potential energy surfaces were generated for surface hopping trajectory calculations, using Tully's fewest switches surface hopping algorithm. Preliminary results for the trajectory calculations are presented. The calculated probability of a CO((sup 1) sigma plus) and O((sup 3) P) collision leading to singlet CO2 formation is on the order of 10 (sup -4). The predicted flowfield conditions for various Mars entry scenarios predict temperatures in the range of 1000 degrees Kelvin - 4000 degrees Kelvin and pressures in the range of 300-2500 pascals at the shoulder and in the wake, which is consistent with a heavy-particle collision frequency of 10 (sup 6) to 10 (sup 7) per second. Owing to this low collision frequency, it is likely that CO((sup 1) sigma plus) molecules formed by this mechanism will mostly be frozen in a highly nonequilibrium rovibrational energy state until they relax by photoemission.

  8. Trichoderma .beta.-glucosidase

    Science.gov (United States)

    Dunn-Coleman, Nigel; Goedegebuur, Frits; Ward, Michael; Yao, Jian

    2006-01-03

    The present invention provides a novel .beta.-glucosidase nucleic acid sequence, designated bgl3, and the corresponding BGL3 amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding BGL3, recombinant BGL3 proteins and methods for producing the same.

  9. Applied Beta Dosimetry

    International Nuclear Information System (INIS)

    Rich, B.L.

    1986-01-01

    Measurements of beta and/or nonpenetrating exposure results is complicated and past techniques and capabilities have resulted in significant inaccuracies in recorded results. Current developments have resulted in increased capabilities which make the results more accurate and should result in less total exposure to the work force. Continued development of works in progress should provide equivalent future improvements

  10. Beta thalassemia - a review

    Directory of Open Access Journals (Sweden)

    R Jha

    2014-09-01

    Full Text Available Thalassemia is a globin gene disorder that results in a diminished rate of synthesis of one or more of the globin chains. About 1.5% of the global population (80 to 90 million people are carriers of beta Thalassemia. More than 200 mutations are described in beta thalassemia. However not all mutations are common in different ethnic groups. The only effective way to reduce burden of thalassemia is to prevent birth of homozygotes. Diagnosis of beta thalassemia can be done by fetal DNA analysis for molecular defects of beta thalassemia or by fetal blood analysis. Hematopoietic stem cell transplantation is the only available curative approach for Thalassemia. Many patients with thalassemia in underdeveloped nations die in childhood or adolescence. Programs that provide acceptable care, including transfusion of safe blood and supportive therapy including chelation must be established.DOI: http://dx.doi.org/10.3126/jpn.v4i8.11609 Journal of Pathology of Nepal; Vol.4,No. 8 (2014 663-671

  11. Double Beta Decay Experiments

    International Nuclear Information System (INIS)

    Piepke, A.

    2005-01-01

    The experimental observation of neutrino oscillations and thus neutrino mass and mixing gives a first hint at new particle physics. The absolute values of the neutrino mass and the properties of neutrinos under CP-conjugation remain unknown. The experimental investigation of the nuclear double beta decay is one of the key techniques for solving these open problems

  12. The pleiotropic roles of transforming growth factor beta inhomeostasis and carcinogenesis of endocrine organs.

    Energy Technology Data Exchange (ETDEWEB)

    Fleisch, Markus C.; Maxwell, Christopher A.; Barcellos-Hoff,Mary-Helen

    2006-01-13

    Transforming growth factor beta (TGF-beta) is a ubiquitous cytokine that plays a critical role in numerous pathways regulating cellular and tissue homeostasis. TGF-beta is regulated by hormones and is a primary mediator of hormone response in uterus, prostate and mammary gland. This review will address the role of TGF-beta in regulating hormone dependent proliferation and morphogenesis. The subversion of TGF-beta regulation during the processes of carcinogenesis, with particular emphasis on its effects on genetic stability and epithelial to mesenchymal transition (EMT), will also be examined. An understanding of the multiple and complex mechanisms of TGF-beta regulation of epithelial function, and the ultimate loss of TGF-beta function during carcinogenesis, will be critical in the design of novel therapeutic interventions for endocrine-related cancers.

  13. Beta cell adaptation in pregnancy

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    2016-01-01

    Pregnancy is associated with a compensatory increase in beta cell mass. It is well established that somatolactogenic hormones contribute to the expansion both indirectly by their insulin antagonistic effects and directly by their mitogenic effects on the beta cells via receptors for prolactin...... and growth hormone expressed in rodent beta cells. However, the beta cell expansion in human pregnancy seems to occur by neogenesis of beta cells from putative progenitor cells rather than by proliferation of existing beta cells. Claes Hellerström has pioneered the research on beta cell growth for decades...... in the expansion of the beta cell mass in human pregnancy, and the relative roles of endocrine factors and nutrients....

  14. Chimpanzees share forbidden fruit.

    Directory of Open Access Journals (Sweden)

    Kimberley J Hockings

    2007-09-01

    Full Text Available The sharing of wild plant foods is infrequent in chimpanzees, but in chimpanzee communities that engage in hunting, meat is frequently used as a 'social tool' for nurturing alliances and social bonds. Here we report the only recorded example of regular sharing of plant foods by unrelated, non-provisioned wild chimpanzees, and the contexts in which these sharing behaviours occur. From direct observations, adult chimpanzees at Bossou (Republic of Guinea, West Africa very rarely transferred wild plant foods. In contrast, they shared cultivated plant foods much more frequently (58 out of 59 food sharing events. Sharing primarily consists of adult males allowing reproductively cycling females to take food that they possess. We propose that hypotheses focussing on 'food-for-sex and -grooming' and 'showing-off' strategies plausibly account for observed sharing behaviours. A changing human-dominated landscape presents chimpanzees with fresh challenges, and our observations suggest that crop-raiding provides adult male chimpanzees at Bossou with highly desirable food commodities that may be traded for other currencies.

  15. Forbidden time travel

    DEFF Research Database (Denmark)

    Nøjgaard, Nikolai; Geiß, Manuela; Merkle, Daniel

    2017-01-01

    tree T with a species trees S, relative to the reconciliation problem without prior knowledge of the event types. It is well-known that optimal reconciliations in the unlabeled case may violate time-consistency and thus are not biologically feasible. Here we investigate the mathematical structure...... of the event labeled reconciliation problem with horizontal transfer. Results: We investigate the issue of time-consistency for the event-labeled version of the reconciliation problem, provide a convenient axiomatic framework, and derive a complete characterization of time-consistent reconciliations....... This characterization depends on certain weak conditions on the event-labeled gene trees that reflect conditions under which evolutionary events are observable at least in principle. We give an O(|V (T)| log(|V (S)|))-time algorithm to decide whether a time-consistent reconciliation map exists. It does not require...

  16. Misleading Betas: An Educational Example

    Science.gov (United States)

    Chong, James; Halcoussis, Dennis; Phillips, G. Michael

    2012-01-01

    The dual-beta model is a generalization of the CAPM model. In the dual-beta model, separate beta estimates are provided for up-market and down-market days. This paper uses the historical "Anscombe quartet" results which illustrated how very different datasets can produce the same regression coefficients to motivate a discussion of the…

  17. Evolution of single-particle structure and beta-decay near 78Ni

    Directory of Open Access Journals (Sweden)

    Borzov I. N.

    2012-12-01

    Full Text Available The extended self-consistent beta-decay model has been applied for bet-decay rates and delayed neutron emission probabilities of spherical neutron-rich isotopes near the r-process paths. Unlike a popular global FRDM+RPA model, in our fully microscopic approach, the Gamow-Teller and first-forbidden decays are treated on the same footing. The model has been augmented by blocking of the odd particle in order to account for important ground-state spin-parity inversion effect which has been shown to exist in the region of the most neutron-rich doubly-magic nucleus 78Ni. Finally, a newly developed form of density functional DF3a has been employed which gives a better spin-orbit splitting due to the modified tensor components of the density functional.

  18. Interaction with beta-arrestin determines the difference in internalization behavor between beta1- and beta2-adrenergic receptors.

    Science.gov (United States)

    Shiina, T; Kawasaki, A; Nagao, T; Kurose, H

    2000-09-15

    The beta(1)-adrenergic receptor (beta(1)AR) shows the resistance to agonist-induced internalization. As beta-arrestin is important for internalization, we examine the interaction of beta-arrestin with beta(1)AR with three different methods: intracellular trafficking of beta-arrestin, binding of in vitro translated beta-arrestin to intracellular domains of beta(1)- and beta(2)ARs, and inhibition of betaAR-stimulated adenylyl cyclase activities by beta-arrestin. The green fluorescent protein-tagged beta-arrestin 2 translocates to and stays at the plasma membrane by beta(2)AR stimulation. Although green fluorescent protein-tagged beta-arrestin 2 also translocates to the plasma membrane, it returns to the cytoplasm 10-30 min after beta(1)AR stimulation. The binding of in vitro translated beta-arrestin 1 and beta-arrestin 2 to the third intracellular loop and the carboxyl tail of beta(1)AR is lower than that of beta(2)AR. The fusion protein of beta-arrestin 1 with glutathione S-transferase inhibits the beta(1)- and beta(2)AR-stimulated adenylyl cyclase activities, although inhibition of the beta(1)AR-stimulated activity requires a higher concentration of the fusion protein than that of the beta(2)AR-stimulated activity. These results suggest that weak interaction of beta(1)AR with beta-arrestins explains the resistance to agonist-induced internalization. This is further supported by the finding that beta-arrestin can induce internalization of beta(1)AR when beta-arrestin 1 does not dissociate from beta(1)AR by fusing to the carboxyl tail of beta(1)AR.

  19. Magnitude of a conformational change in the glycine receptor beta1-beta2 loop is correlated with agonist efficacy

    DEFF Research Database (Denmark)

    Pless, Stephan Alexander; Lynch, Joseph W

    2009-01-01

    associated with the closed-flip transition in the alpha1-glycine receptor. We employed voltage-clamp fluorometry to compare ligand-binding domain conformational changes induced by the following agonists, listed from highest to lowest affinity and efficacy: glycine > beta-alanine > taurine. Voltage...

  20. Exchange effects in double beta decay

    International Nuclear Information System (INIS)

    Stephenson, G.J. Jr.; Goldman, T.; Maltman, K.R.; Schmidt, K.E.

    1988-01-01

    The motivation underlying the resurgence of interest in double beta decay is the hope that the observation of or limits on the 0-neutrino mode will provide information about the nature of the neutrino. This clearly requires confidence in the nuclear matrix elements involved in the transition. The shell model calculations do not agree well with the geochemical values for 130 Te, which has lead to a spate of papers offering specific fixes for the problem. In this contribution we shall not comment on any of the specific nuclear calculations, rather we make some remarks which should be relevant to any model calculation

  1. Electron Reorganization in Allowed and Forbidden Reactions: Multicenter Bond Indices as a Measure of Aromaticity and/or Anti-aromaticity in Transition States of Pericyclic Electrocyclizations

    Czech Academy of Sciences Publication Activity Database

    Mandado, M.; Ponec, Robert

    2009-01-01

    Roč. 22, č. 12 (2009), s. 1225-1232 ISSN 0894-3230 R&D Projects: GA ČR GA203/09/0118 Institutional research plan: CEZ:AV0Z40720504 Keywords : pericycli reactions * aromaticity * multicenter bond indices Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.602, year: 2009

  2. Low-beta investment strategies

    OpenAIRE

    Korn, Olaf; Kuntz, Laura-Chloé

    2015-01-01

    This paper investigates investment strategies that exploit the low-beta anomaly. Although the notion of buying low-beta stocks and selling high-beta stocks is natural, a choice is necessary with respect to the relative weighting of high-beta stocks and low-beta stocks in the investment portfolio. Our empirical results for US large-cap stocks show that this choice is very important for the risk-return characteristics of the resulting portfolios and their sensitivities to common risk factors. W...

  3. Neutrophil beta-2 microglobulin: an inflammatory mediator

    DEFF Research Database (Denmark)

    Bjerrum, O W; Nissen, Mogens Holst; Borregaard, N

    1990-01-01

    Beta-2 microglobulin (beta 2m) constitutes the light invariant chain of HLA class I antigen, and is a constituent of mobilizable compartments of neutrophils. Two forms of beta 2m exist: native beta 2m and proteolytically modified beta 2m (Des-Lys58-beta 2m), which shows alpha mobility in crossed ...

  4. Beta-thalassemia

    Directory of Open Access Journals (Sweden)

    Origa Raffaella

    2010-05-01

    Full Text Available Abstract Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands, dilated myocardiopathy, liver fibrosis and cirrhosis. Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes, gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely

  5. Beta and Gamma Gradients

    DEFF Research Database (Denmark)

    Løvborg, Leif; Gaffney, C. F.; Clark, P. A.

    1985-01-01

    Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions...... of differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears...... that the present practice of avoiding samples above a depth of 0.3 m may be over-cautious...

  6. Regulation of beta cell replication

    DEFF Research Database (Denmark)

    Lee, Ying C; Nielsen, Jens Høiriis

    2008-01-01

    Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

  7. High beta experiments in CHS

    International Nuclear Information System (INIS)

    Okamura, S.; Matsuoka, K.; Nishimura, K.

    1994-09-01

    High beta experiments were performed in the low-aspect-ratio helical device CHS with the volume-averaged equilibrium beta up to 2.1 %. These values (highest for helical systems) are obtained for high density plasmas in low magnetic field heated with two tangential neutral beams. Confinement improvement given by means of turning off gas puffing helped significantly to make high betas. Magnetic fluctuations increased with increasing beta, but finally stopped to increase in the beta range > 1 %. The coherent modes appearing in the magnetic hill region showed strong dependence on the beta values. The dynamic poloidal field control was applied to suppress the outward plasma movement with the plasma pressure. Such an operation gave fixed boundary operations of high beta plasmas in helical systems. (author)

  8. Beta rays and neutrinos

    International Nuclear Information System (INIS)

    Adams, S.F.

    1992-01-01

    It was over 30 years between the first observation of the enigmatic process of beta decay and the first postulation of the neutrino. It took a further 26 years until the first neutrino was detected and yet another 27 until the electroweak theory was confirmed by the discovery of W and Z particles. This article traces some of the puzzles and paradoxes associated with the history of the neutrino. (author)

  9. Coroutine Sequencing in BETA

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger

    In object-oriented programming, a program execution is viewed as a physical model of some real or imaginary part of the world. A language supporting object-oriented programming must therefore contain comprehensive facilities for modeling phenomena and concepts form the application domain. Many...... applications in the real world consist of objects carrying out sequential processes. Coroutines may be used for modeling objects that alternate between a number of sequential processes. The authors describe coroutines in BETA...

  10. COM Support in BETA

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann

    1999-01-01

    Component technologies based on binary units of independent production are some of the most important contributions to software architecture and reuse during recent years. Especially the COM technologies and the CORBA standard from the Object Management Group have contributed new and interesting...... principles for software architecture, and proven to be useful in parctice. In this paper ongoing work with component support in the BETA language is described....

  11. Background analysis for the beta-spectrum of the isotope 113Cd in the COBRA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Platzek, Stephan [Technische Universitaet Dresden (Germany); Collaboration: COBRA-Collaboration

    2016-07-01

    The COBRA experiment uses Cadmium-Zinc-Telluride as detector material. This semiconductor contains several isotopes that are candidates for neutrinoless double beta-decay. Due to the natural abundance of the detector material various other isotopes are present as well. One of them is {sup 113}Cd with an abundance of about 12%. The fourfold forbidden non-unique beta-decay of {sup 113}Cd is a rare process with a half-life of about 8.10{sup 15} years. The shape of the spectrum is still topic of scientific discussions because of various forecasts given by theoretical models. The signal related to this decay is by far the most prominent in the COBRA setup causing more than 98% of the total rate. In this talk potential background components contributing to the {sup 113}Cd beta-spectrum are discussed with the aim to develop a detailed background simulation with the program VENOM (based on Geant4), that includes background sources originating from cosmic activation as well as natural radioactivity and detector specific effects.

  12. First-forbidden mirror β-decays in A = 17 mass region and the role of proton halo in 17F

    International Nuclear Information System (INIS)

    Michel, N.; Okolowicz, J.; Ploszajczak, M.; Okolowicz, J.; Nowacki, F.; Ploszajczak, M.

    2001-01-01

    The first-forbidden β-decay of 17 Ne into the 'halo' state J π 1/2 + 1 of 17 F presents one of the largest measured asymmetries for mirror β-decay feeding bound final states. This asymmetry is studied in the framework of the Shell Model Embedded in the Continuum (SMEC). The spatial extent of single particle orbits calculated in SMEC is constrained by the proton capture cross-section 16 O(p,γ) 17 F. This allows to estimate the mirror symmetry breaking in 17 F and 17 O nuclei. (authors)

  13. LHCb: $2\\beta_s$ measurement at LHCb

    CERN Multimedia

    Conti, G

    2009-01-01

    A measurement of $2\\beta_s$, the phase of the $B_s-\\bar{B_s}$ oscillation amplitude with respect to that of the ${\\rm b} \\rightarrow {\\rm c^{+}}{\\rm W^{-}}$ tree decay amplitude, is one of the key goals of the LHCb experiment with first data. In the Standard Model (SM), $2\\beta_s$ is predicted to be $0.0360^{+0.0020}_{-0.0016} \\rm rad$. The current constraints from the Tevatron are: $2\\beta_{s}\\in[0.32 ; 2.82]$ at 68$\\%$CL from the CDF experiment and $2\\beta_{s}=0.57^{+0.24}_{-0.30}$ from the D$\\oslash$ experiment. Although the statistical uncertainties are large, these results hint at the possible contribution of New Physics in the $B_s-\\bar{B_s}$ box diagram. After one year of data taking at LHCb at an average luminosity of $\\mathcal{L}\\sim2\\cdot10^{32}\\rm cm^{-2} \\rm s^{-1}$ (integrated luminosity $\\mathcal{L}_{\\rm int}\\sim 2 \\rm fb^{-1}$), the expected statistical uncertainty on the measurement is $\\sigma(2\\beta_s)\\simeq 0.03$. This uncertainty is similar to the $2\\beta_s$ value predicted by the SM.

  14. Role of nuclear penetration effects in spin assignments. [J, transitions, internal conversion

    Energy Technology Data Exchange (ETDEWEB)

    Sahota, H S [Punjabi Univ., Patiala (India). Dept. of Physics

    1976-04-01

    Nuclear penetrations have been found to affect the internal conversion process of the retarded magnetic dipole transitions. In all cases where the penetration coefficient has been found to be essentially different from unity the transition is 1-forbidden. This criterian has been applied to the case of 191 keV transition in /sup 197/Au where the spin of the 268 keV level could not be deduced uniquely by any of the existing methods. The result is that the 199 keV transition has a dynamic contribution to its internal conversion process with the penetration coefficient lambda = 5.5 +- 0.9. To illustrate the applicability of the criterian further two more cases namely that of the 92 keV transition in /sup 131/Cs and 182 keV transition in /sup 129/Cs are also included.

  15. Anderson Transition of Cold Atoms with Synthetic Spin-Orbit Coupling in Two-Dimensional Speckle Potentials

    Science.gov (United States)

    Orso, Giuliano

    2017-03-01

    We investigate the metal-insulator transition occurring in two-dimensional (2D) systems of noninteracting atoms in the presence of artificial spin-orbit interactions and a spatially correlated disorder generated by laser speckles. Based on a high order discretization scheme, we calculate the precise position of the mobility edge and verify that the transition belongs to the symplectic universality class. We show that the mobility edge depends strongly on the mixing angle between Rashba and Dresselhaus spin-orbit couplings. For equal couplings a non-power-law divergence is found, signaling the crossing to the orthogonal class, where such a 2D transition is forbidden.

  16. Laser-induced fluorescences due to quadrupole moment transition and Stark effect in a He glow discharge

    International Nuclear Information System (INIS)

    Sakai, Hisashi; Takiyama, Ken; Kimura, Masahiko; Yamasaki, Motokuni; Fujita, Toshiaki; Oda, Toshiatsu; Kawasaki, Ken.

    1993-01-01

    The electric quadrupole moment transition and the Stark effect are investigated in a He hollow cathode discharge with laser-induced fluorescence method. It is shown that the forbidden transition from 2 1 S to 3 1 D in the negative glow is dominantly due to the quadrupole moment transition. This absorption coefficient is obtained from the laser-induced fluorescence intensity measurement in which the collisional transfers are taken into account. The result agrees with the theoretical coefficient. In the cathode dark space the fluorescence due to the Stark effect is also observed. Spatial distribution of the fluorescence is discussed, compared with the electric field distribution in the dark space. (author)

  17. Branching ratios of radiative transitions in O VI

    International Nuclear Information System (INIS)

    Sur, Chiranjib; Chaudhuri, Rajat K

    2007-01-01

    We study the branching ratios of the allowed and forbidden radiative transitions among the first few (9) fine structure levels of O VI using relativistic coupled-cluster theory. We find irregular patterns for a number of transitions within n-complexes with n ≤ 4. We have used the existing values of the allowed electric dipole (E1) transition as a benchmark of our theory. Good agreement with the existing values establish accuracies of not only the theoretical method but the basis function as well. In general, the electric quadrupole (E2) transition probabilities are greater in magnitude than magnetic dipole (M1) transition probabilities, whereas for medium atomic transition frequencies they are of the same order of magnitude. On the other hand, if the transitions involved are in between two fine-structure components of the same term, then the M1 transition probability is more probable than that of E2. The results presented here in tabular and graphical form are compared with the available theoretical and observed data. Graphical analysis helps to understand the trends of electric and magnetic transitions for the decay channels presented here. Our calculated values of the lifetimes of the excited states are in very good agreement with the available results

  18. Critically Evaluated Energy Levels, Spectral Lines, Transition Probabilities, and Intensities of Neutral Vanadium (V i)

    Energy Technology Data Exchange (ETDEWEB)

    Saloman, Edward B. [Dakota Consulting, Inc., 1110 Bonifant Street, Suite 310, Silver Spring, MD 20910 (United States); Kramida, Alexander [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)

    2017-08-01

    The energy levels, observed spectral lines, and transition probabilities of the neutral vanadium atom, V i, have been compiled. Also included are values for some forbidden lines that may be of interest to the astrophysical community. Experimental Landé g -factors and leading percentage compositions for the levels are included where available, as well as wavelengths calculated from the energy levels (Ritz wavelengths). Wavelengths are reported for 3985 transitions, and 549 energy levels are determined. The observed relative intensities normalized to a common scale are provided.

  19. Transitional Justice

    DEFF Research Database (Denmark)

    Gissel, Line Engbo

    This presentation builds on an earlier published article, 'Contemporary Transitional Justice: Normalising a Politics of Exception'. It argues that the field of transitional justice has undergone a shift in conceptualisation and hence practice. Transitional justice is presently understood to be th...... to be the provision of ordinary criminal justice in contexts of exceptional political transition.......This presentation builds on an earlier published article, 'Contemporary Transitional Justice: Normalising a Politics of Exception'. It argues that the field of transitional justice has undergone a shift in conceptualisation and hence practice. Transitional justice is presently understood...

  20. Coherent generation of symmetry-forbidden phonons by light-induced electron-phonon interactions in magnetite

    Science.gov (United States)

    Borroni, S.; Baldini, E.; Katukuri, V. M.; Mann, A.; Parlinski, K.; Legut, D.; Arrell, C.; van Mourik, F.; Teyssier, J.; Kozlowski, A.; Piekarz, P.; Yazyev, O. V.; Oleś, A. M.; Lorenzana, J.; Carbone, F.

    2017-09-01

    Symmetry breaking across phase transitions often causes changes in selection rules and emergence of optical modes which can be detected via spectroscopic techniques or generated coherently in pump-probe experiments. In second-order or weakly first-order transitions, fluctuations of the ordering field are present above the ordering temperature, giving rise to intriguing precursor phenomena, such as critical opalescence. Here, we demonstrate that in magnetite (Fe3O4 ) light excitation couples to the critical fluctuations of the charge order and coherently generates structural modes of the ordered phase above the critical temperature of the Verwey transition. Our findings are obtained by detecting coherent oscillations of the optical constants through ultrafast broadband spectroscopy and analyzing their dependence on temperature. To unveil the coupling between the structural modes and the electronic excitations, at the origin of the Verwey transition, we combine our results from pump-probe experiments with spontaneous Raman scattering data and theoretical calculations of both the phonon dispersion curves and the optical constants. Our methodology represents an effective tool to study the real-time dynamics of critical fluctuations across phase transitions.

  1. Enantioselective synthesis of alpha,beta-disubstituted-beta-amino acids.

    Science.gov (United States)

    Sibi, Mukund P; Prabagaran, Narayanasamy; Ghorpade, Sandeep G; Jasperse, Craig P

    2003-10-01

    Highly diastereoselective and enantioselective addition of N-benzylhydroxylamine to imides 17 and 20-30 produces alpha,beta-trans-disubstituted N-benzylisoxazolidinones 19 and 31-41. These reactions proceed in 60-96% ee with 93-99% de's using 5 mol % of Mg(NTf2)2 and ligand 18. The product isoxazolidinones can be hydrogenolyzed directly to provide alpha,beta-disubstituted-beta-amino acids.

  2. Forbidden energy band gap in diluted a-Ge{sub 1-x}Si{sub x}:N films

    Energy Technology Data Exchange (ETDEWEB)

    Guarneros, C.; Rebollo-Plata, B. [Posgrado en Fisica Aplicada, Facultad de Ciencias Fisico-Matematicas, Benemerita Universidad Autonoma de Puebla, Blvd. 14 Sur 6301, Col. San Manuel, 72570, Puebla (Mexico); Lozada-Morales, R., E-mail: rlozada@fcfm.buap.mx [Posgrado en Fisica Aplicada, Facultad de Ciencias Fisico-Matematicas, Benemerita Universidad Autonoma de Puebla, Blvd. 14 Sur 6301, Col. San Manuel, 72570, Puebla (Mexico); Espinosa-Rosales, J.E. [Posgrado en Fisica Aplicada, Facultad de Ciencias Fisico-Matematicas, Benemerita Universidad Autonoma de Puebla, Blvd. 14 Sur 6301, Col. San Manuel, 72570, Puebla (Mexico); Portillo-Moreno, J. [Facultad de Ciencias Quimicas, Benemerita Universidad Autonoma de Puebla, Blvd. 14 Sur 6301, Col. San Manuel, 72570, Puebla (Mexico); Zelaya-Angel, O. [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN, PO Box 14-740, Mexico 07360 D.F. (Mexico)

    2012-06-01

    By means of electron gun evaporation Ge{sub 1-x}Si{sub x}:N thin films, in the entire range 0 {<=} x {<=} 1, were prepared on Si (100) and glass substrates. The initial vacuum reached was 6.6 Multiplication-Sign 10{sup -4} Pa, then a pressure of 2.7 Multiplication-Sign 10{sup -2} Pa of high purity N{sub 2} was introduced into the chamber. The deposition time was 4 min. Crucible-substrate distance was 18 cm. X-ray diffraction patterns indicate that all the films were amorphous (a-Ge{sub 1-x}Si{sub x}:N). The nitrogen concentration was of the order of 1 at% for all the films. From optical absorption spectra data and by using the Tauc method the energy band gap (E{sub g}) was calculated. The Raman spectra only reveal the presence of Si-Si, Ge-Ge, and Si-Ge bonds. Nevertheless, infrared spectra demonstrate the existence of Si-N and Ge-N bonds. The forbidden energy band gap (E{sub g}) as a function of x in the entire range 0 {<=} x {<=} 1 shows two well defined regions: 0 {<=} x {<=} 0.67 and 0.67 {<=} x {<=} 1, due to two different behaviors of the band gap, where for x > 0.67 exists an abruptly change of E{sub g}(x). In this case E{sub g}(x) versus x is different to the variation of E{sub g} in a-Ge{sub 1-x}Si{sub x} and a-Ge{sub 1-x}Si{sub x}:H. This fact can be related to the formation of Ge{sub 3}N{sub 4} and GeSi{sub 2}N{sub 4} when x {<=} 0.67, and to the formation of Si{sub 3}N{sub 4} and GeSi{sub 2}N{sub 4} for 0.67 {<=} x. - Highlights: Black-Right-Pointing-Pointer Nitrogen doped amorphous Ge{sub 1-x}Si{sub x} thin films are grown by electron gun technique. Black-Right-Pointing-Pointer Nitrogen atoms on E{sub g} of the a-Ge{sub 1-x}Si{sub x} films in the 0 Pound-Sign x Pound-Sign 1 range are analyzed. Black-Right-Pointing-Pointer Variation in 0 Pound-Sign x Pound-Sign 1 range shows a warped change of E{sub g} in 1.0 - 3.6 eV range. Black-Right-Pointing-Pointer The change in E{sub g}(x) behavior when x {approx} 0.67 was associated with Ge{sub 2}SiN{sub 4

  3. Double beta decay in gauge theories

    International Nuclear Information System (INIS)

    Vergados, J.D.

    2002-01-01

    Neutrinoless double beta decay is a very important process both from the particle and nuclear physics point of view. From the elementary particle point of view it pops up in almost every model, giving rise among others to the following mechanisms: a) The traditional contributions like the light neutrino mass mechanism as well as the j L - j R leptonic interference (λ and η terms). b) The exotic R-parity violating supersymmetric (SUSY) contributions. From the nuclear physics point of view it is challenging, because: 1) The nuclei, which can undergo double beta decay, have complicated nuclear structure. 2) The energetically allowed transitions are suppressed (exhaust a small part of all the strength). 3) Since in some mechanisms the intermediate particles are very heavy one must cope with the short distance behavior of the transition operators. 4) The intermediate momenta involved are quite high and one has to consider momentum dependent terms of the nucleon current. Taking the above effects into account from the experimental limits on the interesting nuclei A=76, 82, 96, 100, 116, 128, 130, 136 and 150, we have extracted new limits on the various lepton violating parameters. In particular we get a stringent limit on the R-parity violating parameter λ' 111 -4 . (author)

  4. Beta measurement evaluation and upgrade

    International Nuclear Information System (INIS)

    Swinth, K.L.; Rathbun, L.A.; Roberson, P.L.; Endres, G.W.R.

    1986-01-01

    This program focuses on the resolution of problems associated with the field measurement of the beta dose component at Department of Energy (DOE) facilities. The change in DOE programs, including increased efforts in improved waste management and decontamination and decommissioning (D and D) of facilities, coupled with beta measurement problems identified at Three Mile Island has increased the need to improve beta measurements. In FY 1982, work was initiated to provide a continuing effort to identify problems associated with beta dose assessment at DOE facilities. The problems identified resulted in the development of this program. The investigation includes (1) an assessment of measurement systems now in use, (2) development of improved calibration systems and procedures, (3) application of innovative beta dosimetry concepts, (4) investigation of new instruments or concepts for monitoring and spectroscopy, and (5) development of recommendations to assure an adequate beta measurement program within DOE facilities

  5. Beta Neutrino Correlation Measurement with Trapped Radioactive Ions

    International Nuclear Information System (INIS)

    Velten, Ph.; Ban, G.; Durand, D.; Flechard, X.; Lienard, E.; Mauger, F.; Naviliat-Cuncic, O.; Mery, A.; Rodriguez, D.; Thomas, J.-C.

    2010-01-01

    The beta-neutrino angular correlation coefficient provides a sensitive observable to search for physics beyond the standard electroweak model in nuclear beta decay. We address here the measurement of this parameter in the pure Gamow-Teller transition of 6 He. A deviation from the standard model prediction would indicate the existence of tensor like couplings, possibly mediated by new bosons like leptoquarks. The aim of the LPCTrap experiment is to measure this coefficient with a statistical uncertainty of 0.5% using a novel transparent Paul trap. The status of the experiment is briefly presented along with the work in progress.

  6. Structural analyses of polymorphic transitions of sn-1, 3-distearoyl-2-oleoylglycerol (SOS) and sn-1, 3-dioleoyl-2-stearoylglycerol (OSO): assessment on steric hindrance of unsaturated and saturated acyl chain interactions.

    Science.gov (United States)

    Yano, J; Sato, K; Kaneko, F; Small, D M; Kodali, D R

    1999-01-01

    Polymorphic transformations in two saturated-unsaturated mixed acid triacylglycerols, SOS (sn -1,3-distearoyl-2-oleoylglycerol) and OSO (sn -1,3-dioleoyl-2-stearoylglycerol), have been studied by FT-IR spectroscopy using deuterated specimens in which stearoyl chains are fully deuterated. A reversible phase transition between sub alpha and alpha and a series of irreversible transitions (alpha-->gamma-->beta'-->beta (beta2, beta1) for SOS and alpha-->beta'-->beta for OSO) were studied with an emphasis on the conformational ordering process of stearoyl and oleoyl chains. The alpha-->sub alpha reversible transition was due to the orientational change of stearoyl chains in the lateral directions from the hexagonal subcell to a perpendicularly packed one. As the first stage of the series of irreversible transitions from alpha to beta, the conformational ordering of saturated chains took place in the alpha-->gamma transition of SOS and in the alpha-->beta' transition of OSO; one stearoyl chain in SOS and OSO takes the all-trans conformation and the second stearoyl chain in SOS takes the bent conformation like those observed in the most stable beta-type. As the final stage, the ordering of unsaturated chains occurred in the beta'-->beta transition both for SOS and OSO. A conversion in the layered structure from bilayer to trilayer was also accompanied by the conformational ordering in the alpha-->gamma transition of SOS and in the beta'-->beta transition of OSO.

  7. Conditional Betas and Investor Uncertainty

    OpenAIRE

    Fernando D. Chague

    2013-01-01

    We derive theoretical expressions for market betas from a rational expectation equilibrium model where the representative investor does not observe if the economy is in a recession or an expansion. Market betas in this economy are time-varying and related to investor uncertainty about the state of the economy. The dynamics of betas will also vary across assets according to the assets' cash-flow structure. In a calibration exercise, we show that value and growth firms have cash-flow structures...

  8. Dynamic returns of beta arbitrage

    OpenAIRE

    Nascimento, Mafalda

    2017-01-01

    This thesis studies the patterns of the abnormal returns of the beta strategy. The topic can be helpful for professional investors, who intend to achieve a better performance in their portfolios. Following the methodology of Lou, Polk, & Huang (2016), the COBAR measure is computed in order to determine the levels of beta arbitrage in the market in each point in time. It is argued that beta arbitrage activity can have impact on the returns of the beta strategy. In fact, it is demonstrated that...

  9. Integration of BETA with Eclipse

    DEFF Research Database (Denmark)

    Andersen, Peter; Madsen, Ole Lehrmann; Enevoldsen, Mads Brøgger

    2004-01-01

    This paper presents language interoperability issues appearing in order to implement support for the BETA language in the Java-based Eclipse integrated development environment. One of the challenges is to implement plug-ins in BETA and be able to load them in Eclipse. In order to do this, some fo...... it is possible to implement plug-ins in BETA and even inherit from Java classes. In the paper the two approaches are described together with part of the mapping from BETA to Java class files. http://www.sciencedirect.com/science/journal/15710661...

  10. Simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  11. A computational protocol for the study of circularly polarized phosphorescence and circular dichroism in spin-forbidden absorption

    DEFF Research Database (Denmark)

    Kaminski, Maciej; Cukras, Janusz; Pecul, Magdalena

    2015-01-01

    We present a computational methodology to calculate the intensity of circular dichroism (CD) in spinforbidden absorption and of circularly polarized phosphorescence (CPP) signals, a manifestation of the optical activity of the triplet–singlet transitions in chiral compounds. The protocol is based...

  12. Identification of active anti-inflammatory principles of beta- beta ...

    African Journals Online (AJOL)

    chromatography. Components of the extracts were identified by thin layer chromatography (TLC) scanner and UV-visible spectroscopy, using scopoletin as standard. Results: ... basic coumarin skeleton ring structure reduce ... Figure 2: Thin-layer chromatogram: (1) Ethanol extract; (2) Dichloromethane fraction; (3) Beta-beta.

  13. Improved limits on beta(-) and beta(-) decays of Ca-48

    Czech Academy of Sciences Publication Activity Database

    Bakalyarov, A.; Balysh, A.; Barabash, AS.; Beneš, P.; Briancon, C.; Brudanin, V. B.; Čermák, P.; Egorov, V.; Hubert, F.; Hubert, P.; Korolev, NA.; Kosjakov, VN.; Kovalík, Alojz; Lebedev, NA.; Novgorodov, A. F.; Rukhadze, NI.; Štekl, NI.; Timkin, VV.; Veleshko, IE.; Vylov, T.; Umatov, VI.

    2002-01-01

    Roč. 76, č. 9 (2002), s. 545-547 ISSN 0021-3640 Institutional research plan: CEZ:AV0Z1048901 Keywords : beta decay * double beta decay * Ca-48 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.483, year: 2002

  14. Conversion of beta-methylbutyric acid to beta-hydroxy-beta-methylbutyric acid by Galactomyces reessii.

    OpenAIRE

    Lee, I Y; Nissen, S L; Rosazza, J P

    1997-01-01

    beta-Hydroxy-beta-methylbutyric acid (HMB) has been shown to increase strength and lean mass gains in humans undergoing resistance-exercise training. HMB is currently marketed as a calcium salt of HMB, and thus, environmentally sound and inexpensive methods of manufacture are being sought. This study investigates the microbial conversion of beta-methylbutyric acid (MBA) to HMB by cultures of Galactomyces reessii. Optimal concentrations of MBA were in the range of 5 to 20 g/liter for HMB produ...

  15. Metabolic clearance rate and urinary clearance of purified beta-core

    International Nuclear Information System (INIS)

    Wehmann, R.E.; Blithe, D.L.; Flack, M.R.; Nisula, B.C.

    1989-01-01

    We injected a highly purified preparation of the beta-core molecule, a fragment of hCG beta excreted in pregnancy urine, into five men and three women to determine its kinetic parameters, MCR, and urinary clearance. The beta-core molecule was distributed in an initial volume [1950 +/- 156 (mean +/- SEM) mL/m2 body surface area] approximately equal to the estimated plasma volume. Its disappearance was multiexponential on a semilogarithmic plot, with a rapid phase t1/2 of 3.5 +/- 0.7 min and a slow phase t1/2 of 22.4 +/- 4.2 min. The transit time (the mean time spent by a molecule of beta-core in transit) was 20.6 +/- 2.1 min. The MCR was 192.0 +/- 8.0 mL/min.m2 body surface area. About 5% of the injected dose of beta-core was excreted into the urine in the first 30 min after injection, and low levels of excretion persisted for up to 7 days. The urinary clearance rate of beta-core was 13.7 +/- 1.4 mL/min.m2, accounting for about 8% of the elimination of beta-core from the plasma. The beta-core immunoreactivity in serum and urine was characterized by gel filtration and three independent RIA systems to show that its properties were indistinguishable from those of the injected beta-core. Serum levels of beta-core in pregnant women were less than 0.2 ng/mL, while the amounts excreted in their urine were as much as 5 mg/day. Based on these clearance parameters of beta-core in normal subjects, less than 0.2% of the beta-core excreted in pregnancy urine is derived by urinary clearance of plasma beta-core. Therefore, more than 99% of the beta-core excreted in pregnancy urine is derived from beta-core in a compartment separate from plasma. In particular, these data indicate that there is relatively little placental secretion of beta-core into plasma and that placental secretion does not account for the vast majority of beta-core in pregnancy urine

  16. The best-beta CAPM

    NARCIS (Netherlands)

    Zou, L.

    2006-01-01

    The issue of 'best-beta' arises as soon as potential errors in the Sharpe-Lintner-Black capital asset pricing model (CAPM) are acknowledged. By incorporating a target variable into the investor preferences, this study derives a best-beta CAPM (BCAPM) that maintains the CAPM's theoretical appeal and

  17. Beta decay of Cu-56

    NARCIS (Netherlands)

    Borcea, R; Aysto, J; Caurier, E; Dendooven, P; Doring, J; Gierlik, M; Gorska, M; Grawe, H; Hellstrom, M; Janas, Z; Jokinen, A; Karny, M; Kirchner, R; La Commara, M; Langanke, K; Martinez-Pinedo, G; Mayet, P; Nieminen, A; Nowacki, F; Penttila, H; Plochocki, A; Rejmund, M; Roeckl, E; Schlegel, C; Schmidt, K; Schwengner, R; Sawicka, M

    2001-01-01

    The proton-rich isotope Cu-56 was produced at the GSI On-Line Mass Separator by means of the Si-28(S-32, p3n) fusion-evaporation reaction. Its beta -decay properties were studied by detecting beta -delayed gamma rays and protons. A half-Life of 93 +/- 3 ms was determined for Cu-56. Compared to the

  18. Review of the beta situation

    International Nuclear Information System (INIS)

    Sheffield, J.

    1982-01-01

    This note lists some of the possible causes of beta limitation in tokamak and discusses what is known and what is involved in investigating them. The motivation for preparing this note is the observed degradation of confinement with increasing beta poloidal β/sub p/ and beam power P/sub b/ in ISX-B

  19. Supporting Transition

    Science.gov (United States)

    Qureshi, Asima; Petrucco, James

    2018-01-01

    Meadowbrook Primary School has explored the use of The Teacher Assessment in Primary Science (TAPS) to support transition, initially for transfer to secondary school and now for transition from Early Years Foundation Stage (EYFS) into Key Stage 1 (ages 5-7). This article will consider an example of a secondary transition project and discuss the…

  20. Study of $\\beta$-delayed neutron decay of $^{8}$He

    CERN Multimedia

    The goal of the present proposal is to study $\\beta$-delayed neutron decay branch of $^{8}$He. The energy spectra of the emitted neutrons will be measured in the energy range of 0.1 – 6 MeV using the VANDLE spectrometer. Using coincident $\\gamma$-ray measurement, components of the spectrum corresponding to transitions to the ground- and first- excited states of $^{7}$Li will be disentangled. The new data will allow us to get a more complete picture of the $\\beta$-decay of $^{8}$He and to clarify the discrepancy between the B(GT) distributions derived from the $\\beta$-decay and $^{8}$He(p, n)$^{8}$Li reaction studies.

  1. Beta-delayed neutron decay of $^{33}$Na

    CERN Document Server

    Radivojevic, Z; Caurier, E; Cederkäll, J; Courtin, S; Dessagne, P; Jokinen, A; Knipper, A; Le Scornet, G; Lyapin, V G; Miehé, C; Nowacki, F; Nummela, S; Oinonen, M; Poirier, E; Ramdhane, M; Trzaska, W H; Walter, G; Äystö, J

    2002-01-01

    Beta-delayed neutron decay of /sup 33/Na has been studied using the on-line mass separator ISOLDE. The delayed neutron spectra were measured by time-of-flight technique using fast scintillators. Two main neutron groups at 800(60) and 1020(80) keV were assigned to the /sup 33/Na decay, showing evidence for strong feeding of states at about 4 MeV in /sup 33/Mg. By simultaneous beta - gamma -n counting the delayed neutron emission probabilities P/sub 1n/ = 47(6)% and P /sub 2n/ = 13(3)% were determined. The half-life value for /sup 33 /Na, T/sub 1/2/ = 8.0(3) ms, was measured by three different techniques, one employing identifying gamma transitions and two employing beta and neutron counting. (21 refs).

  2. High beta and second stability region transport and stability analysis

    International Nuclear Information System (INIS)

    1991-01-01

    This document describes ideal and resistive MHD studies of high-beta plasmas and of the second stability region. Significant progress is reported on the resistive stability properties of high beta poloidal ''supershot'' discharges. For these studies initial profiles were taken from the TRANSP code which is used extensively to analyze experimental data. When an ad hoc method of removing the finite pressure stabilization of tearing modes is implemented it is shown that there is substantial agreement between MHD stability computation and experiment. In particular, the mode structures observed experimentally are consistent with the predictions of the resistive MHD model. We also report on resistive stability near the transition to the second region in TFTR. Tearing modes associated with a nearby infernal mode may explain the increase in MHD activity seen in high beta supershots and which impede the realization of Q∼1. We also report on a collaborative study with PPPL involving sawtooth stabilization with ICRF

  3. RAVEN Beta Release

    International Nuclear Information System (INIS)

    Rabiti, Cristian; Alfonsi, Andrea; Cogliati, Joshua Joseph; Mandelli, Diego; Kinoshita, Robert Arthur; Wang, Congjian; Maljovec, Daniel Patrick; Talbot, Paul William

    2016-01-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  4. RAVEN Beta Release

    Energy Technology Data Exchange (ETDEWEB)

    Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alfonsi, Andrea [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cogliati, Joshua Joseph [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kinoshita, Robert Arthur [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wang, Congjian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Maljovec, Daniel Patrick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Talbot, Paul William [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  5. Interactions between two beta-sheets. Energetics of beta/beta packing in proteins.

    Science.gov (United States)

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

    1986-04-20

    The analysis of the interactions between regularly folded segments of the polypeptide chain contributes to an understanding of the energetics of protein folding. Conformational energy-minimization calculations have been carried out to determine the favorable ways of packing two right-twisted beta-sheets. The packing of two five-stranded beta-sheets was investigated, with the strands having the composition CH3CO-(L-Ile)6-NHCH3 in one beta-sheet and CH3CO-(L-Val)6-NHCH3 in the other. Two distinct classes of low-energy packing arrangements were found. In the class with lowest energies, the strands of the two beta-sheets are aligned nearly parallel (or antiparallel) with each other, with a preference for a negative orientation angle, because this arrangement corresponds to the best complementary packing of the two twisted saddle-shaped beta-sheets. In the second class, with higher interaction energies, the strands of the two beta-sheets are oriented nearly perpendicular to each other. While the surfaces of the two beta-sheets are not complementary in this arrangement, there is good packing between the corner of one beta-sheet and the interior part of the surface of the other, resulting in a favorable energy of packing. Both classes correspond to frequently observed orientations of beta-sheets in proteins. In proteins, the second class of packing is usually observed when the two beta-sheets are covalently linked, i.e. when a polypeptide strand passes from one beta-sheet to the other, but we have shown here that a large contribution to the stabilization of this packing arrangement arises from noncovalent interactions.

  6. Melting of a beta-Hairpin Peptide Using Isotope-Edited 2D IR Spectroscopy and Simulations

    NARCIS (Netherlands)

    Smith, Adam W.; Lessing, Joshua; Ganim, Ziad; Peng, Chunte Sam; Tokmakoff, Andrei; Roy, Santanu; Jansen, Thomas L. C.; Knoester, Jasper

    2010-01-01

    Isotope-edited two-dimensional infrared spectroscopy has been used! to characterize the conformational heterogeneity of the beta-hairpin peptide TrpZip2 (17.2) across its thermal unfolding transition Four isotopologues were synthesized to probe hydrogen bonding and solvent exposure of the beta-turn

  7. Melting of a beta-hairpin peptide using isotope-edited 2D IR spectroscopy and simulations.

    NARCIS (Netherlands)

    Smith, A.W.; Lessing, J.; Ganim, Z.; Peng, C.S.; Tokmakoff, A.; Roy, S.; Jansen, T.L.Th.A.; Knoester, J.

    2010-01-01

    Isotope-edited two-dimensional infrared spectroscopy has been used to characterize the conformational heterogeneity of the beta-hairpin peptide TrpZip2 (TZ2) across its thermal unfolding transition. Four isotopologues were synthesized to probe hydrogen bonding and solvent exposure of the beta-turn

  8. Comparative study of {beta} decays and of the model of the layers for the nucleus with odd a; Etude comparee des desintegrations {beta} et du modele des couches pour les noyaux de a impair

    Energy Technology Data Exchange (ETDEWEB)

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

    1953-07-01

    The systematic comparison of {beta} decays of the cores of number of odd mass with the predictions of the modal of Mrs. Mayer on spins and parities, has already been made by several authors. It is taken in the present work with more recent experimental data and with a method of classification of the {beta} transitions. A simultaneous comparison to the experience of the model of the layers and the theory of the {beta} transitions can serve to verify one and the other too. In the present work, it appeared more fruitful to try to verify the model of the layers with the help of the very established theory of the {beta} transitions. One will look to verify and perfect the models of the layers for transitions between fundamental states or isomers of the cores. (M.B.) [French] La comparaison systematique des desintegrations {beta} des noyaux de nombre de masse impair avec les predictions du modale de Mme MAYER sur les spins et les parites, a deja ete faite par plusieurs auteurs. Elle est reprise dans le present travail avec des donnees experimentales plus recentes et avec une methode de classification des transitions {beta}. Une comparaison simultanee a l'experience du modele des couches et de la theorie des transitions {beta} peut, a priori, servir a verifier egalement l'un et l'autre. Dans le present travail, il a paru plus fructueux de chercher a verifier le modele des couches a l'aide de la theorie bien etablie des transitions {beta}. On cherchera de verifier et de perfectionner le modele des couches pour les transitions entre etats fondamentaux ou isomeres des noyaux. (M.B.)

  9. Derivatives of the Incomplete Beta Function

    Directory of Open Access Journals (Sweden)

    Robert J. Boik

    1998-03-01

    Full Text Available The incomplete beta function is defined as where Beta(p, q is the beta function. Dutka (1981 gave a history of the development and numerical evaluation of this function. In this article, an algorithm for computing first and second derivatives of Ix,p,q with respect to p and q is described. The algorithm is useful, for example, when fitting parameters to a censored beta, truncated beta, or a truncated beta-binomial model.

  10. Development of beta reference radiations

    International Nuclear Information System (INIS)

    Wan Zhaoyong; Cai Shanyu; Li Yanbo; Yin Wei; Feng Jiamin; Sun Yuhua; Li Yongqiang

    1997-09-01

    A system of beta reference radiation has been developed, that is composed of 740 MBq 147 Pm beta source, 74 MBq and 740 MBq 90 Sr + 90 Y β sources, compensation filters, a source handling tool, a source jig, spacing bars, a shutter, a control unit and a beta dose meter calibration stand. For 740 MBq 147 Pm and 74 MBq 90 Sr + 90 Y beta reference radiations with compensation filters and 740 MBq 90 Sr + 90 Y beta reference radiation without compensation filter, at 20 cm, 30 cm and 30 cm distance separately; the residual energy of maximum is 0.14 MeV, 1.98 MeV and 2.18 MeV separately; the absorbed dose to tissue D (0.07) is 1.547 mGy/h (1996-05-20), 5.037 mGy/h (1996-05-10) and 93.57 mGy/h (1996-05-15) separately; the total uncertainty is 3.0%, 1.7% and 1.7% separately. For the first and the second beta reference radiation, the dose rate variability in the area of 18 cm diameter in the plane perpendicular to the beta-ray beam axis is within +-6% and +-3% separately. (3 refs., 2 tabs., 8 figs.)

  11. A semiconductor beta ray spectrometer

    International Nuclear Information System (INIS)

    Bom, V.R.

    1987-01-01

    Measurement of energy spectra of beta particles emitted from nuclei in beta-decay processes provides information concerning the mass difference of these nuclei between initial and final state. Moreover, experimental beta spectra yield information on the feeding of the levels in the daughter nucleus. Such data are valuable in the construction and checking of the level schemes. This thesis describes the design, construction, testing and usage of a detector for the accurate measurement of the mentioned spectra. In ch. 2 the design and construction of the beta spectrometer, which uses a hyper-pure germanium crystal for energy determination, is described. A simple wire chamber is used to discriminate beta particles from gamma radiation. Disadvantages arise from the large amounts of scattered beta particles deforming the continua. A method is described to minimize the scattering. In ch. 3 some theoretical aspects of data analysis are described and the results of Monte-Carlo simulations of the summation of annihilation radiation are compared with experiments. Ch. 4 comprises the results of the measurements of the beta decay energies of 103-108 In. 87 refs.; 34 figs.; 7 tabs

  12. BETA (Bitter Electromagnet Testing Apparatus)

    Science.gov (United States)

    Bates, Evan M.; Birmingham, William J.; Rivera, William F.; Romero-Talamas, Carlos A.

    2017-10-01

    The Bitter Electromagnet Testing Apparatus (BETA) is a 1-Tesla (T) prototype of the 10-T Adjustable Long Pulse High-Field Apparatus (ALPHA). These water-cooled resistive magnets use high DC currents to produce strong uniform magnetic fields. Presented here is the successful completion of the BETA project and experimental results validating analytical magnet designing methods developed at the Dusty Plasma Laboratory (DPL). BETA's final design specifications will be highlighted which include electromagnetic, thermal and stress analyses. The magnet core design will be explained which include: Bitter Arcs, helix starters, and clamping annuli. The final version of the magnet's vessel and cooling system are also presented, as well as the electrical system of BETA, which is composed of a unique solid-state breaker circuit. Experimental results presented will show the operation of BETA at 1 T. The results are compared to both analytical design methods and finite element analysis calculations. We also explore the steady state maximums and theoretical limits of BETA's design. The completion of BETA validates the design and manufacturing techniques that will be used in the succeeding magnet, ALPHA.

  13. Double Charge Exchange Reactions and Double Beta Decay

    Science.gov (United States)

    Auerbach, N.

    2018-05-01

    The subject of this presentation is at the forefront of nuclear physics, namely double beta decay. In particular one is most interested in the neutrinoless process of double beta decay, when the decay proceeds without the emission of two neutrinos. The observation of such decay would mean that the lepton conservation symmetry is violated and that the neutrinos are of Majorana type, meaning that they are their own anti-particles. The life time of this process has two unknowns, the mass of the neutrino and the nuclear matrix element. Determining the nuclear matrix element and knowing the cross-section well will set limits on the neutrino mass. There is a concentrated effort among the nuclear physics community to calculate this matrix element. Usually these matrix elements are a very small part of the total strength of the transition operators involved in the process. There is no simple way to “calibrate” the nuclear double beta decay matrix element. The double beta decay is a double charge exchange process, therefore it is proposed that double charge exchange reactions using ion projectiles on nuclei that are candidates for double beta decay, will provide additional necessary information about the nuclear matrix elements.

  14. Transitions between beta and gamma rhythms in neural systems

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Setsinsky, D.; Fausbøll, Anders

    2002-01-01

    We study the coexistence of different rhythms in a local network of one inhibitory and two excitatory nerve cells for a wide range of the excitatory synapse strength and of the slow K+-channel conductance. The dynamic features of spike trains in the presence of noise are discussed. It is found...... that noise can both cause switching between different states and induce coherent firing events....

  15. Transitions between beta and gamma rhythms in neural systems

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Setsinsky, D; Fausbøll, Anders

    2002-01-01

    We study the coexistence of different rhythms in a local network of one inhibitory and two excitatory nerve cells for a wide range of the excitatory synapse strength and of the slow K+-channel conductance. The dynamic features of spike trains in the presence of noise are discussed. It is found...

  16. The structure of nuclei far from beta stability

    International Nuclear Information System (INIS)

    Zganjar, E.F.

    1991-01-01

    This report discusses the structural of nuclei for from beta stability of the following isotopes: thallium isotopes; mercury isotopes; gold isotopes; platinum isotopes; iridium isotopes; the neutron deficient rare-earth, Z = 57-72 region, and the neutron deficient Z = 50-56 region; also discussed are in-beam spectroscopy in the A = 70 region and shape coexistence, intruder states, and EO transitions

  17. Inner bremsstrahlung accompanying beta decay of 170Tm

    International Nuclear Information System (INIS)

    Sanjeeviah, H.; Venkataramaiah, P.; Gundu Rao, K.S.

    1980-01-01

    The inner bremmsstrahlung (IB) spectrum accompanying beta decay of 170 Tm was measured using magnetic deflection technique. The raw spectrum was unfolded using the procedure of Liden and Starfelt. The unfolded IB spectrum was compared with the theories of Knipp and Uhlenbeck and Bloch; Lewis and Ford. Comparison was made with Ford and Martin theory in order to estimate the contribution of detour transitions to the IB spectrum of 170 Tm. (author)

  18. Transition radiation and transition scattering

    International Nuclear Information System (INIS)

    Ginzburg, V.L.

    1982-01-01

    Transition radiation is a process of a rather general character. It occurs when some source, which does not have a proper frequency (for example, a charge) moves at a constant velocity in an inhomogeneous and (or) nonstationary medium or near such a medium. The simplest type of transition radiation takes place when a charge crosses a boundary between two media (the role of one of the media may be played by vacuum). In the case of periodic variation of the medium, transition radiation possesses some specific features (resonance transition radiation or transition scattering). Transition scattering occurs, in particular, when a permittivity wave falls onto an nonmoving (fixed) charge. Transition scattering is closely connected with transition bremsstrahlung radiation. All these transition processes are essential for plasma physics. Transition radiation and transition scattering have analogues outside the framework of electrodynamics (like in the case of Vavilov-Cherenkov radiation). In the present report the corresponding range of phenomena is elucidated, as far as possible, in a generally physical aspect. (Auth.)

  19. Schematic model studies of double beta decay processes

    International Nuclear Information System (INIS)

    Civitarese, O.

    1996-01-01

    Some features of the nuclear matrix elements, for double beta decay transitions to a final ground state and to a final excited one and two-quadrupole phonon states, are presented and discussed in the framework of a schematic model. The competition between spin-flip and non-spin-flip transitions on the relevant nuclear matrix elements, the effects due to proton-neutron pairing correlations and the effects due to the inclusion of exchange terms in the QRPA matrix are discussed. (Author)

  20. Experiments on double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Busto, J [Neuchatel Univ. (Switzerland). Inst. de Physique

    1996-11-01

    The Double Beta Decay, and especially ({beta}{beta}){sub 0{nu}} mode, is an excellent test of Standard Model as well as of neutrino physics. From experimental point of view, a very large number of different techniques are or have been used increasing the sensitivity of this experiments quite a lot (the factor of 10{sup 4} in the last 20 years). In future, in spite of several difficulties, the sensitivity would be increased further, keeping the interest of this very important process. (author) 4 figs., 5 tabs., 21 refs.

  1. Preventive Effects of Beta-Hydroxy-Beta-Methyl Butyrate

    OpenAIRE

    N. Ravanbakhsh; N. Torabi; M. Foadoddini

    2016-01-01

    Aims: One of the major factors in sudden cardiac arrest is the initiation and continuation of deadly arrhythmias during ischemia. It is known that beta-hydroxy-beta-methylbutyrate (HMB) has useful effects such as anti-inflammatory and anti-apoptosis effects in the skeletal muscles. The aim of this study was to investigate the preventive effects of HMB on the ventricular arrhythmias due to the ischemia. Materials & Methods: In the experimental study, 30 Wistar male rats were randomly div...

  2. Dosimetry of {beta} extensive sources; Dosimetria de fuentes {beta} extensas

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E.L.; Lallena R, A.M. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain)

    2002-07-01

    In this work, we have been studied, making use of the Penelope Monte Carlo simulation code, the dosimetry of {beta} extensive sources in situations of spherical geometry including interfaces. These configurations are of interest in the treatment of the called cranealfaringyomes of some synovia leisure of knee and other problems of interest in medical physics. Therefore, its application can be extended toward problems of another areas with similar geometric situation and beta sources. (Author)

  3. ω→π0γ* and ϕ→π0γ* transition form factors in dispersion theory

    Science.gov (United States)

    Schneider, Sebastian P.; Kubis, Bastian; Niecknig, Franz

    2012-09-01

    We calculate the ω→π0γ* and ϕ→π0γ* electromagnetic transition form factors based on dispersion theory, relying solely on a previous dispersive analysis of the corresponding three-pion decays and the pion vector form factor. We compare our findings to recent measurements of the ω→π0μ+μ- decay spectrum by the NA60 collaboration, and strongly encourage experimental investigation of the Okubo-Zweig-Iizuka forbidden ϕ→π0ℓ+ℓ- decays in order to understand the strong deviations from vector-meson dominance found in these transition form factors.

  4. Double Beta Decay

    International Nuclear Information System (INIS)

    Fiorini, Ettore

    2008-01-01

    The importance of neutrinoless Double Beta Decay (DBD) is stressed in view of the recent results of experiments on neutrino oscillations which indicate that the difference between the squared masses of two neutrinos of different flavours is finite [For a recent review including neutrino properties and recent results see: Review of Particle Physics, J. of Phys. G: Nuclear and Particle Physics 33, 1]. As a consequence the mass of at least one neutrino has to be different from zero and it becomes imperative to determine its absolute value. The various experimental techniques to search for DBD are discussed together with the difficult problems of the evaluation of the corresponding nuclear matrix elements. The upper limits on neutrino mass coming from the results of the various experiments are reported together with the indication for a non zero value by one of them not confirmed so far. The two presently running experiments on neutrinoless DBD are briefly described together with the already approved or designed second generation searches aiming to reach the values on the absolute neutrino mass indicated by the results on neutrino oscillations

  5. Is neutrinoless double beta decay suppressed

    International Nuclear Information System (INIS)

    Tomoda, T.

    1989-01-01

    Much effort has been devoted to the study of nuclear double beta decay, since the observation of a neutrinoless double beta (OνΒΒ) decay would be clear evidence that the electron neutrino is a Majorana particle. The OνΒΒ decay is caused by a finite Majorana neutrino mass and/or an admixture of right-handed leptonic currents. In order to relate these quantities to OνΒΒ decay rates, we need nuclear matrix elements, which are model dependent. One of the possibilities of testing nuclear models employed in such analysis is to calculate the experimentally known rates of ΒΒ decay with emission of two neutrinos (2νΒΒ decay) which occurs independently of the nature of the neutrino. There was a long-standing difficulty in such attempts that the calculated 2νΒΒ decay rates turned out to be always too large by one to two orders of magnitude. Trying to overcome such difficulty, Klapdor and Grotz as well as Vogel and Zirnbauer showed in their calculation using schematic effective interactions such that 2νΒΒ decay rates can get reduced considerably due to the nuclear ground state correlations. This paper reports that the suppression is ascribed to that of the virtual Gamow-Teller transitions from the excited 1 + states of the intermediate odd-odd -even nucleus

  6. Double beta decay: a new formalism

    International Nuclear Information System (INIS)

    Hirsch, J.; Krmpotic, F.

    1990-01-01

    A study is made of the validity of those methods consisting in an average of solutions from initial and final solutions within the quasi-particle random phase approximation (QRPA) for double beta decay. A new method is developed that works with a single QRPA equation for the intermediate nucleus in which the correlations of the ground state for β - transitions are β + and vice versa. Numerical results agree in the different formulations, which avails the known averaging procedures while showing the greater operative simplicity of the proposed method for the case of the two neutrino mode in which the diagonalization process may be substituted by a matrix inversion. (Author). 13 refs., 1 fig., 1 tab

  7. Induction of cell scattering by expression of beta1 integrins in beta1-deficient epithelial cells requires activation of members of the rho family of GTPases and downregulation of cadherin and catenin function

    DEFF Research Database (Denmark)

    Gimond, C; van Der Flier, A; van Delft, S

    1999-01-01

    different beta1-null cell lines, epithelial GE11 and fibroblast-like GD25 cells. Expression of beta1A or the cytoplasmic splice variant beta1D, induced the disruption of intercellular adherens junctions and cell scattering in both GE11 and GD25 cells. In GE11 cells, the morphological change correlated...... for a complete morphological transition towards the spindle-shaped fibroblast-like phenotype. The expression of an interleukin-2 receptor (IL2R)-beta1A chimera and its incorporation into focal adhesions also induced the disruption of cadherin-based adhesions and the reorganization of ECM-cell contacts...

  8. Molecular effects in the neutrino mass determination from beta-decay of the tritium molecule

    International Nuclear Information System (INIS)

    Fackler, O.; Jeziorski, B.; Kolos, W.; Szalewicz, K.; Monkhorst, H.J.; Mugge, M.

    1986-03-01

    Molecular final state energies and transition probabilities have been computed for beta-decay of the tritium molecule. The results are of sufficient accuracy to make a determination of the electron neutrino rest mass with an error not exceeding a few tenths of an electron volt. Effects of approximate models of tritium beta-decay on the neutrino mass determination are discussed. 14 refs., 3 figs., 1 tab

  9. The search for Majorana neutrinos with neutrinoless double beta decays: From CUORICINO to LUCIFER experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bellini, F. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma I-00185 (Italy) and INFN - Sezione di Roma, Roma I-00185 (Italy)

    2012-11-20

    The study of neutrino properties is one of the fundamental challenges in particle physics nowadays. Fifty years of investigations established that neutrinos are massive but the absolute mass scale has not yet been measured. Moreover its true nature is still unknown. Is the neutrino its own antiparticle (thus violating the lepton number) as proposed by Majorana in 1937? The only way to probe the neutrino nature is through the observation of Neutrinoless Double Beta Decay (0{nu}{beta}{beta}), a very rare spontaneous nuclear transition which emits two electrons and no neutrinos. In this paper, after a brief introduction to the theoretical framework of Majorana's neutrino, a presentation of experimental challenges posed by 0{nu}{beta}{beta} search will be given as well as an overview of present status and future perpectives of experiments.

  10. Variation of the energy gap of the SbSI crystals at ferroelectric phase transition

    International Nuclear Information System (INIS)

    Audzijonis, A.; Zaltauskas, R.; Zigas, L.; Vinokurova, I.V.; Farberovich, O.V.; Pauliukas, A.; Kvedaravicius, A.

    2006-01-01

    Variation of the forbidden gap of SbSI crystals in the phase transition region is analyzed on the pseudopotential method for antiferroelectric and ferroelectric phase. The band gap at several special points of the Brillouin zone and some characteristic parameters of the band are considered. During the phase transition, the most significant changes are observed with the valence band top at points Q, C, R, H, E and with the conduction band bottom at points H, T and E of the Brillouin zone. At the ferroelectric phase transition, the valence and conduction bands change due to displacement of Sb and S atoms with respect to I and with respect to each other as a result of order-disorder and displacement-type transition. The obtained band gap values agree quite well with the experiment. This is apparently due to application of neutral rather than ionic atomic functions and inclusion of sufficiently many plane waves in the basis set for calculation

  11. Absolute Transition Probabilities from the 453.1 keV Level in 183W

    International Nuclear Information System (INIS)

    Malmskog, S.G.

    1966-10-01

    The half life of the 453.1 keV level in 183 W has been measured by the delayed coincidence method to 18.4 ± 0.5 nsec. This determines twelve absolute M1 and E2 transition probabilities, out of which nine are K-forbidden. All transition probabilities are compared with the single particle estimate. The three K-allowed E2, ΔK = 2 transition rates to the 1/2 - (510) rotational band are furthermore compared with the Nilsson model. An attempt to give a quantitative explanation of the observed transition rates has been made by including the effects from admixtures into the single particle wave functions

  12. Absolute Transition Probabilities from the 453.1 keV Level in {sup 183}W

    Energy Technology Data Exchange (ETDEWEB)

    Malmskog, S G

    1966-10-15

    The half life of the 453.1 keV level in {sup 183}W has been measured by the delayed coincidence method to 18.4 {+-} 0.5 nsec. This determines twelve absolute M1 and E2 transition probabilities, out of which nine are K-forbidden. All transition probabilities are compared with the single particle estimate. The three K-allowed E2, {delta}K = 2 transition rates to the 1/2{sup -} (510) rotational band are furthermore compared with the Nilsson model. An attempt to give a quantitative explanation of the observed transition rates has been made by including the effects from admixtures into the single particle wave functions.

  13. Electric Monopole Transition Strengths in the Stable Nickel Isotopes

    Science.gov (United States)

    Evitts, Lee John

    A series of measurements of stable nickel isotopes were performed at the Australian National University in Canberra. Excited states in 58,60,62Ni were populated via inelastic scattering of proton beams delivered by the 14UD Pelletron accelerator. Multiple setups were used in order to determine the structure of low-lying states. The CAESAR array of Compton-suppressed HPGe detectors was used to measure the (E2/M1) mixing ratio of transitions from angular distributions of gamma rays. The Super-e spectrometer was used to measure conversion coefficients for a number of J to J transitions. The data obtained from both devices was combined with previously measured parent lifetimes and branching ratios to determine E0 transition strengths between J-pi transitions. The E0 transition strength for the second 0+ to first 0+ transitions in 60,62Ni have been measured for the first time through internal conversion electron detection. The experimental value of 132(+59,-70) for 62Ni agrees within 2 sigma of the previous result obtained from internal pair formation. However it is likely that the previous experimental results used an outdated theoretical model for internal pair formation emission. This work also represents the first measurements of E0 transition strengths between 2+ states in Ni isotopes. There is generally large E0 strength between the 2+ states, particularly in the second 2+ to first 2+ transition, however there is also a large uncertainty in the measurements owing to the difficulties involved in measuring conversion coefficients. In 62Ni, the E0 transition strength of 172(+62,-77) for the second 2+ to first 2+ transition gives further weight to the argument against the spherical vibrator model, as an E0 transition is forbidden if there is a change of only one phonon. The large measurement also indicates the presence of shape coexistence, complementing the recent experimental work carried out in the neutron-rich Ni isotopes.

  14. (beta-HC CG) in

    African Journals Online (AJOL)

    raoul

    Urothelial tumour samples were obtained from all the 86 patients requiring surgical ..... and/or urine beta HCG appears to be an efficient diagnostic marker for the ..... collected all urothelial tumour specimens for storage, cutting and staining.

  15. Beta-glucans and cholesterol

    Czech Academy of Sciences Publication Activity Database

    Šíma, Petr; Vannucci, Luca; Větvička, V.

    2017-01-01

    Roč. 41, č. 4 (2017), s. 1799-1808 ISSN 1107-3756 Institutional support: RVO:61388971 Keywords : cholesterol * beta-glucans * diet Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 2.341, year: 2016

  16. Radioisotope indicator, type BETA 2

    International Nuclear Information System (INIS)

    Duszanski, M.; Pankow, A.; Skwarczynski, B.

    1975-01-01

    The authors describe a radioisotope indicator, type BETA 2, constructed in the ZKMPW Works to be employed in mines for counting, checking, signalling the presence and positioning of cars, as well as monitoring the state of some other equipment. (author)

  17. Phase transitions

    CERN Document Server

    Sole, Ricard V; Solé, Ricard V; Solé, Ricard V; Sol, Ricard V; Solé, Ricard V

    2011-01-01

    Phase transitions--changes between different states of organization in a complex system--have long helped to explain physics concepts, such as why water freezes into a solid or boils to become a gas. How might phase transitions shed light on important problems in biological and ecological complex systems? Exploring the origins and implications of sudden changes in nature and society, Phase Transitions examines different dynamical behaviors in a broad range of complex systems. Using a compelling set of examples, from gene networks and ant colonies to human language and the degradation of diverse ecosystems, the book illustrates the power of simple models to reveal how phase transitions occur. Introductory chapters provide the critical concepts and the simplest mathematical techniques required to study phase transitions. In a series of example-driven chapters, Ricard Solé shows how such concepts and techniques can be applied to the analysis and prediction of complex system behavior, including the origins of ...

  18. Observation of Rydberg transitions from the inner valence shell of ethane

    International Nuclear Information System (INIS)

    Dillon, M.A.; Tanaka, H.; Spence, D.

    1987-01-01

    The electron impact spectrum of ethane has been examined in a region that includes ionization out of the inner valence shell. One diffuse structure and a progression of ten vibrational bands have been found in a 4 eV range below and to some degree overlapping the 2 A 2 /sub u/ ion threshold. Evidence indicates that the observed transitions belong to the symmetry forbidden Rydberg series (2a 2 /sub u/) 2 →(2a 2 /sub u/, npσ or npπ)

  19. μ+e-↔μ-e+ transitions via neutral scalar bosons

    International Nuclear Information System (INIS)

    Hou, W.; Wong, G.

    1996-01-01

    With μ→eγ decay forbidden by multiplicative lepton number conservation, we study muonium-antimuonium transitions induced by neutral scalar bosons. Pseudoscalars do not induce conversion for triplet muonium, while, for singlet muonium, pseudoscalar and scalar contributions add constructively. This is in contrast with the usual case of doubly charged scalar exchange, where the conversion rate is the same for both singlet and triplet muonium. Complementary to muonium conversion studies, high energy μ + e - →μ - e + and e - e - →μ - μ - collisions could reveal spectacular resonance peaks for the cases of neutral and doubly charged scalars, respectively. copyright 1996 The American Physical Society

  20. Beta Instability and Stochastic Market Weights

    OpenAIRE

    David H. Goldenberg

    1985-01-01

    An argument is given for individual firm beta instability based upon the stochastic character of the market weights defining the market portfolio and the constancy of its beta. This argument is generalized to market weighted portfolios and the form of the stochastic process generating betas is linked to that of the market return process. The implications of this analysis for adequacy of models of beta nonstationarity and estimation of betas are considered in light of the available empirical e...

  1. The forbidden fuel: Charcoal, urban woodfuel demand and supply dynamics, community forest management and woodfuel policy in Malawi

    International Nuclear Information System (INIS)

    Zulu, Leo Charles

    2010-01-01

    This article examines woodfuel policy challenges and opportunities in Malawi two decades after woodfuel-crisis narratives and counter-narratives. A nuanced examination of woodfuel supply, demand, use, and markets illuminated options to turn stagnant policies based on charcoal 'bans' and fuel-substitution into proactive, realistic ones acknowledging woodfuel dominance and its socio-economic importance. Findings revealed growing, spatially differentiated woodfuel deficits in southern and central Malawi and around Blantyre, Zomba and Lilongwe cities. Poverty, limited electricity access, reliability and generation exacerbated by tariff subsidies, and complex fuel-allocation decisions restricted energy-ladder transitions from woodfuels to electricity, producing an enduring urban-energy mix dominated by charcoal, thereby increasing wood consumption. Diverse socio-political interests prevented lifting of the charcoal 'ban' despite progressive forest laws. Despite implementation challenges, lessons already learnt, efficiency and poverty-reduction arguments, limited government capacity, growing illegal production of charcoal in forest reserves, and its staying power, make targeted community-based forest management (CBFM) approaches more practical for regulated, commercial production of woodfuels than the status quo. New differentiated policies should include commercial woodfuel production and licensing for revenue and ecological sustainability under CBFM or concessions within and outside selected reserves, an enterprise-based approaches for poverty reduction, smallholder/private tree-growing, woodfuel-energy conserving technologies, improved electricity supply and agricultural productivity.

  2. The forbidden fuel. Charcoal, urban woodfuel demand and supply dynamics, community forest management and woodfuel policy in Malawi

    Energy Technology Data Exchange (ETDEWEB)

    Zulu, Leo Charles [Michigan State University, Department of Geography, 103 Geography Building, East Lansing, MI 48823 (United States)

    2010-07-15

    This article examines woodfuel policy challenges and opportunities in Malawi two decades after woodfuel-crisis narratives and counter-narratives. A nuanced examination of woodfuel supply, demand, use, and markets illuminated options to turn stagnant policies based on charcoal 'bans' and fuel-substitution into proactive, realistic ones acknowledging woodfuel dominance and its socio-economic importance. Findings revealed growing, spatially differentiated woodfuel deficits in southern and central Malawi and around Blantyre, Zomba and Lilongwe cities. Poverty, limited electricity access, reliability and generation exacerbated by tariff subsidies, and complex fuel-allocation decisions restricted energy-ladder transitions from woodfuels to electricity, producing an enduring urban-energy mix dominated by charcoal, thereby increasing wood consumption. Diverse socio-political interests prevented lifting of the charcoal 'ban' despite progressive forest laws. Despite implementation challenges, lessons already learnt, efficiency and poverty-reduction arguments, limited government capacity, growing illegal production of charcoal in forest reserves, and its staying power, make targeted community-based forest management (CBFM) approaches more practical for regulated, commercial production of woodfuels than the status quo. New differentiated policies should include commercial woodfuel production and licensing for revenue and ecological sustainability under CBFM or concessions within and outside selected reserves, an enterprise-based approaches for poverty reduction, smallholder/private tree-growing, woodfuel-energy conserving technologies, improved electricity supply and agricultural productivity. (author)

  3. The forbidden fuel: Charcoal, urban woodfuel demand and supply dynamics, community forest management and woodfuel policy in Malawi

    Energy Technology Data Exchange (ETDEWEB)

    Zulu, Leo Charles, E-mail: zulu@msu.ed [Michigan State University, Department of Geography, 103 Geography Building, East Lansing, MI 48823 (United States)

    2010-07-15

    This article examines woodfuel policy challenges and opportunities in Malawi two decades after woodfuel-crisis narratives and counter-narratives. A nuanced examination of woodfuel supply, demand, use, and markets illuminated options to turn stagnant policies based on charcoal 'bans' and fuel-substitution into proactive, realistic ones acknowledging woodfuel dominance and its socio-economic importance. Findings revealed growing, spatially differentiated woodfuel deficits in southern and central Malawi and around Blantyre, Zomba and Lilongwe cities. Poverty, limited electricity access, reliability and generation exacerbated by tariff subsidies, and complex fuel-allocation decisions restricted energy-ladder transitions from woodfuels to electricity, producing an enduring urban-energy mix dominated by charcoal, thereby increasing wood consumption. Diverse socio-political interests prevented lifting of the charcoal 'ban' despite progressive forest laws. Despite implementation challenges, lessons already learnt, efficiency and poverty-reduction arguments, limited government capacity, growing illegal production of charcoal in forest reserves, and its staying power, make targeted community-based forest management (CBFM) approaches more practical for regulated, commercial production of woodfuels than the status quo. New differentiated policies should include commercial woodfuel production and licensing for revenue and ecological sustainability under CBFM or concessions within and outside selected reserves, an enterprise-based approaches for poverty reduction, smallholder/private tree-growing, woodfuel-energy conserving technologies, improved electricity supply and agricultural productivity.

  4. Dark excitons in transition metal dichalcogenides

    Science.gov (United States)

    Malic, Ermin; Selig, Malte; Feierabend, Maja; Brem, Samuel; Christiansen, Dominik; Wendler, Florian; Knorr, Andreas; Berghäuser, Gunnar

    2018-01-01

    Monolayer transition metal dichalcogenides (TMDs) exhibit a remarkably strong Coulomb interaction that manifests in tightly bound excitons. Due to the complex electronic band structure exhibiting several spin-split valleys in the conduction and valence band, dark excitonic states can be formed. They are inaccessibly by light due to the required spin-flip and/or momentum transfer. The relative position of these dark states with respect to the optically accessible bright excitons has a crucial impact on the emission efficiency of these materials and thus on their technological potential. Based on the solution of the Wannier equation, we present the excitonic landscape of the most studied TMD materials including the spectral position of momentum- and spin-forbidden excitonic states. We show that the knowledge of the electronic dispersion does not allow to conclude about the nature of the material's band gap since excitonic effects can give rise to significant changes. Furthermore, we reveal that an exponentially reduced photoluminescence yield does not necessarily reflect a transition from a direct to a nondirect gap material, but can be ascribed in most cases to a change of the relative spectral distance between bright and dark excitonic states.

  5. Tumor-produced, active Interleukin-1 {beta} regulates gene expression in carcinoma-associated fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Dudas, Jozsef, E-mail: Jozsef.Dudas@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Fullar, Alexandra, E-mail: fullarsz@gmail.com [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); 1st Institute of Pathology and Experimental Cancer Research, Semmelweis University, Ulloei ut 26, H-1085 Budapest (Hungary); Bitsche, Mario, E-mail: Mario.Bitsche@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Schartinger, Volker, E-mail: Volker.Schartinger@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Kovalszky, Ilona, E-mail: koval@korb1.sote.hu [1st Institute of Pathology and Experimental Cancer Research, Semmelweis University, Ulloei ut 26, H-1085 Budapest (Hungary); Sprinzl, Georg Mathias, E-mail: Georg.Sprinzl@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Riechelmann, Herbert, E-mail: Herbert.Riechelmann@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria)

    2011-09-10

    Recently we described a co-culture model of periodontal ligament (PDL) fibroblasts and SCC-25 lingual squamous carcinoma cells, which resulted in conversion of normal fibroblasts into carcinoma-associated fibroblasts (CAFs), and in epithelial-mesenchymal transition (EMT) of SCC-25 cells. We have found a constitutive high interleukin-1{beta} (IL1-{beta}) expression in SCC-25 cells in normal and in co-cultured conditions. In our hypothesis a constitutive IL1-{beta} expression in SCC-25 regulates gene expression in fibroblasts during co-culture. Co-cultures were performed between PDL fibroblasts and SCC-25 cells with and without dexamethasone (DEX) treatment; IL1-{beta} processing was investigated in SCC-25 cells, tumor cells and PDL fibroblasts were treated with IL1-{beta}. IL1-{beta} signaling was investigated by western blot and immunocytochemistry. IL1-{beta}-regulated genes were analyzed by real-time qPCR. SCC-25 cells produced 16 kD active IL1-{beta}, its receptor was upregulated in PDL fibroblasts during co-culture, which induced phosphorylation of interleukin-1 receptor-associated kinase-1 (IRAK-1), and nuclear translocalization of NF{kappa}B{alpha}. Several genes, including interferon regulatory factor 1 (IRF1) interleukin-6 (IL-6) and prostaglandin-endoperoxide synthase 2 (COX-2) were induced in CAFs during co-culture. The most enhanced induction was found for IL-6 and COX-2. Treatment of PDL fibroblasts with IL1-{beta} reproduced a time- and dose-dependent upregulation of IL1-receptor, IL-6 and COX-2. A further proof was achieved by DEX inhibition for IL1-{beta}-stimulated IL-6 and COX-2 gene expression. Constitutive expression of IL1-{beta} in the tumor cells leads to IL1-{beta}-stimulated gene expression changes in tumor-associated fibroblasts, which are involved in tumor progression. -- Graphical abstract: SCC-25 cells produce active, processed IL1-{beta}. PDL fibroblasts possess receptor for IL1-{beta}, and its expression is increased 4.56-times in the

  6. Parallel multireference configuration interaction calculations on mini-beta-carotenes and beta-carotene.

    Science.gov (United States)

    Kleinschmidt, Martin; Marian, Christel M; Waletzke, Mirko; Grimme, Stefan

    2009-01-28

    presented. For beta-carotene, where these transition energies are known from experiment, excellent agreement with our calculations is observed.

  7. Transit transparency.

    Science.gov (United States)

    2012-07-01

    Public transit agencies have employed intelligent systems for determining : schedules and routes and for monitoring the real-time location and status of their : vehicle fleets for nearly two decades. But until recently, the data generated by : daily ...

  8. Structural Phase Transition Nomenclature, Report of an IUCr Working Group on Phase Transition Nomenclature

    NARCIS (Netherlands)

    Toleddano, J.C.; Glazer, A.M.; Hahn, Th.; Parthe, E.; Roth, R.S.; Berry, R.S.; Metselaar, R.; Abrahams, S.C.

    1998-01-01

    A compact and intuitive nomenclature is recommended for naming each phase formed by a given material in a sequence of phase transitions as a function of temperature and/or pressure. The most commonly used label for each phase in a sequence, such as [alpha], [beta], ..., I, II, ... etc., is included

  9. Smart Beta or Smart Alpha

    DEFF Research Database (Denmark)

    Winther, Kenneth Lillelund; Steenstrup, Søren Resen

    2016-01-01

    that smart beta investing probably will do better than passive market capitalization investing over time, we believe many are coming to a conclusion too quickly regarding active managers. Institutional investors are able to guide managers through benchmarks and risk frameworks toward the same well......Smart beta has become the flavor of the decade in the investment world with its low fees, easy access to rewarded risk premiums, and appearance of providing good investment results relative to both traditional passive benchmarks and actively managed funds. Although we consider it well documented......-documented smart beta risk premiums and still motivate active managers to avoid value traps, too highly priced small caps, defensives, etc. By constructing the equity portfolios of active managers that resemble the most widely used risk premiums, we show that the returns and risk-adjusted returns measures...

  10. Composition determination of quaternary GaAsPN layers from single X-ray diffraction measurement of quasi-forbidden (002) reflection

    Energy Technology Data Exchange (ETDEWEB)

    Tilli, J.-M., E-mail: juha-matti.tilli@iki.fi; Jussila, H.; Huhtio, T.; Sopanen, M. [Department of Micro and Nanosciences, Aalto University, P.O. Box 13500, FI-00076 Aalto (Finland); Yu, K. M. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2014-05-28

    GaAsPN layers with a thickness of 30 nm were grown on GaP substrates with metalorganic vapor phase epitaxy to study the feasibility of a single X-ray diffraction (XRD) measurement for full composition determination of quaternary layer material. The method is based on the peak intensity of a quasi-forbidden (002) reflection, which is shown to vary with changing arsenic content for GaAsPN. The method works for thin films with a wide range of arsenic contents and shows a clear variation in the reflection intensity as a function of changing layer composition. The obtained thicknesses and compositions of the grown layers are compared with accurate reference values obtained by Rutherford backscattering spectroscopy combined with nuclear reaction analysis measurements. Based on the comparison, the error in the XRD defined material composition becomes larger with increasing nitrogen content and layer thickness. This suggests that the dominating error source is the deteriorated crystal quality due to the nonsubstitutional incorporation of nitrogen into the crystal lattice and strain relaxation. The results reveal that the method overestimates the arsenic and nitrogen content within error margins of about 0.12 and about 0.025, respectively.

  11. Effect of cooler electrons on a compressive ion acoustic solitary wave in a warm ion plasma — Forbidden regions, double layers, and supersolitons

    International Nuclear Information System (INIS)

    Ghosh, S. S.; Sekar Iyengar, A. N.

    2014-01-01

    It is observed that the presence of a minority component of cooler electrons in a three component plasma plays a deterministic role in the evolution of solitary waves, double layers, or the newly discovered structures called supersolitons. The inclusion of the cooler component of electrons in a single electron plasma produces sharp increase in nonlinearity in spite of a decrease in the overall energy of the system. The effect maximizes at certain critical value of the number density of the cooler component (typically 15%–20%) giving rise to a hump in the amplitude variation profile. For larger amplitudes, the hump leads to a forbidden region in the ambient cooler electron concentration which dissociates the overall existence domain of solitary wave solutions in two distinct parameter regime. It is observed that an inclusion of the cooler component of electrons as low as < 1% affects the plasma system significantly resulting in compressive double layers. The solution is further affected by the cold to hot electron temperature ratio. In an adequately hotter bulk plasma (i.e., moderately low cold to hot electron temperature ratio), the parameter domain of compressive double layers is bounded by a sharp discontinuity in the corresponding amplitude variation profile which may lead to supersolitons

  12. Effect of cooler electrons on a compressive ion acoustic solitary wave in a warm ion plasma — Forbidden regions, double layers, and supersolitons

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, S. S., E-mail: sukti@iigs.iigm.res.in [Indian Institute of Geomagnetism, New Panvel, Navi Mumbai 410218 (India); Sekar Iyengar, A. N. [Plasma Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India)

    2014-08-15

    It is observed that the presence of a minority component of cooler electrons in a three component plasma plays a deterministic role in the evolution of solitary waves, double layers, or the newly discovered structures called supersolitons. The inclusion of the cooler component of electrons in a single electron plasma produces sharp increase in nonlinearity in spite of a decrease in the overall energy of the system. The effect maximizes at certain critical value of the number density of the cooler component (typically 15%–20%) giving rise to a hump in the amplitude variation profile. For larger amplitudes, the hump leads to a forbidden region in the ambient cooler electron concentration which dissociates the overall existence domain of solitary wave solutions in two distinct parameter regime. It is observed that an inclusion of the cooler component of electrons as low as < 1% affects the plasma system significantly resulting in compressive double layers. The solution is further affected by the cold to hot electron temperature ratio. In an adequately hotter bulk plasma (i.e., moderately low cold to hot electron temperature ratio), the parameter domain of compressive double layers is bounded by a sharp discontinuity in the corresponding amplitude variation profile which may lead to supersolitons.

  13. Associating a prototypical forbidden food item with guilt or celebration: relationships with indicators of (un)healthy eating and the moderating role of stress and depressive symptoms.

    Science.gov (United States)

    Kuijer, Roeline G; Boyce, Jessica A; Marshall, Emma M

    2015-01-01

    The increase in obesity and the many educational messages prompting us to eat a healthy diet have heightened people's concerns about the effects of food choice on health and weight. An unintended side effect may be that such awareness fuels feelings of guilt and worry about food. Although guilt has the potential to motivate behaviour change, it may also lead to feelings of helplessness and loss of control. The current study examined the relationship between a default association of either 'guilt' or 'celebration' with a prototypical forbidden food item (chocolate cake), indicators of healthy eating and choosing food for mood regulation reasons. Following a 'diathesis-stress' perspective, the moderating roles of depressive symptoms and stress were examined. Although a default association of guilt was found to be harmless under some circumstances (i.e. under low stress), those who associated chocolate cake with guilt (vs. celebration) reported unhealthier eating habits and lower levels of perceived behavioural control over healthy eating when under stress, rated mood regulation reasons for food choice as important irrespective of their current affective state, and did not have more positive attitudes towards healthy eating. Implications for public health messages and interventions will be discussed.

  14. Enhanced light scattering of the forbidden longitudinal optical phonon mode studied by micro-Raman spectroscopy on single InN nanowires

    International Nuclear Information System (INIS)

    Schaefer-Nolte, E O; Stoica, T; Gotschke, T; Limbach, F A; Gruetzmacher, D; Calarco, R; Sutter, E; Sutter, P

    2010-01-01

    In the literature, there are controversies on the interpretation of the appearance in InN Raman spectra of a strong scattering peak in the energy region of the unscreened longitudinal optical (LO) phonons, although a shift caused by the phonon-plasmon interaction is expected for the high conductance observed in this material. Most measurements on light scattering are performed on ensembles of InN nanowires (NWs). However, it is important to investigate the behavior of individual nanowires and here we report on micro-Raman measurements on single nanowires. When changing the polarization direction of the incident light from parallel to perpendicular to the wire, the expected reduction of the Raman scattering was observed for transversal optical (TO) and E 2 phonon scattering modes, while a strong symmetry-forbidden LO mode was observed independently on the laser polarization direction. Single Mg- and Si-doped crystalline InN nanowires were also investigated. Magnesium doping results in a sharpening of the Raman peaks, while silicon doping leads to an asymmetric broadening of the LO peak. The results can be explained based on the influence of the high electron concentration with a strong contribution of the surface accumulation layer and the associated internal electric field.

  15. Enhanced Light Scattering of the Forbidden longitudinal Optical Phonon Mode Studied by Micro-Raman Spectroscopy on Single InN nanowires

    International Nuclear Information System (INIS)

    Sutter, E.; Schafer-Nolte, E.O.; Stoica, T.; Gotschke, T.; Limbach, F.A.; Sutter, P.; Grutzmacher, D.; Calarco, R.

    2010-01-01

    In the literature, there are controversies on the interpretation of the appearance in InN Raman spectra of a strong scattering peak in the energy region of the unscreened longitudinal optical (LO) phonons, although a shift caused by the phonon-plasmon interaction is expected for the high conductance observed in this material. Most measurements on light scattering are performed on ensembles of InN nanowires (NWs). However, it is important to investigate the behavior of individual nanowires and here we report on micro-Raman measurements on single nanowires. When changing the polarization direction of the incident light from parallel to perpendicular to the wire, the expected reduction of the Raman scattering was observed for transversal optical (TO) and E2 phonon scattering modes, while a strong symmetry-forbidden LO mode was observed independently on the laser polarization direction. Single Mg- and Si-doped crystalline InN nanowires were also investigated. Magnesium doping results in a sharpening of the Raman peaks, while silicon doping leads to an asymmetric broadening of the LO peak. The results can be explained based on the influence of the high electron concentration with a strong contribution of the surface accumulation layer and the associated internal electric field.

  16. Enhanced light scattering of the forbidden longitudinal optical phonon mode studied by micro-Raman spectroscopy on single InN nanowires.

    Science.gov (United States)

    Schäfer-Nolte, E O; Stoica, T; Gotschke, T; Limbach, F A; Sutter, E; Sutter, P; Grützmacher, D; Calarco, R

    2010-08-06

    In the literature, there are controversies on the interpretation of the appearance in InN Raman spectra of a strong scattering peak in the energy region of the unscreened longitudinal optical (LO) phonons, although a shift caused by the phonon-plasmon interaction is expected for the high conductance observed in this material. Most measurements on light scattering are performed on ensembles of InN nanowires (NWs). However, it is important to investigate the behavior of individual nanowires and here we report on micro-Raman measurements on single nanowires. When changing the polarization direction of the incident light from parallel to perpendicular to the wire, the expected reduction of the Raman scattering was observed for transversal optical (TO) and E(2) phonon scattering modes, while a strong symmetry-forbidden LO mode was observed independently on the laser polarization direction. Single Mg- and Si-doped crystalline InN nanowires were also investigated. Magnesium doping results in a sharpening of the Raman peaks, while silicon doping leads to an asymmetric broadening of the LO peak. The results can be explained based on the influence of the high electron concentration with a strong contribution of the surface accumulation layer and the associated internal electric field.

  17. Deconfinement and the Hagedorn transition in string theory.

    Science.gov (United States)

    Chaudhuri, S

    2001-03-05

    We introduce a new definition of the thermal partition function in string theory. With this new definition, the thermal partition functions of all of the string theories obey thermal duality relations with self-dual Hagedorn temperature beta(2)(H) = 4pi(2)alpha('). A beta-->beta(2)(H)/beta transformation maps the type I theory into a new string theory (type I) with thermal D p-branes, spatial hypersurfaces supporting a p-dimensional finite temperature non-Abelian Higgs-gauge theory for p< or =9. We demonstrate a continuous phase transition in the behavior of the static heavy quark-antiquark potential for small separations r(2)(*)transitioning through a precise inverse power law at a critical temperature T(D) = T(H)r(*)/(2alpha('))(1/2)pi.

  18. Beta decay of 22O

    International Nuclear Information System (INIS)

    Hubert, F.; Dufour, J.P.; Moral, R. del; Fleury, A.; Jean, D.; Pravikoff, M.S.; Delagrange, H.; Geissel, H.; Schmidt, K.H.; Hanelt, E.

    1989-01-01

    The beta-gamma spectroscopic study of 22 O is presented. This nucleus, produced as a projectile-like fragment from the interaction of a 60 MeV/n 40 Ar beam with a Be target, has been separated by the LISE spectrometer. Several gamma rays from 22 O decay have been observed, from which a half-life of (2.25±0.15) s has been determined. Accurate excitation energies have been deduced for several states in 22 F. A partial beta decay scheme of 22 O has been established. Experimental results have been compared with shell model calculations. (orig.)

  19. Beta-hemolytic Streptococcal Bacteremia

    DEFF Research Database (Denmark)

    Nielsen, Hans Ulrik; Kolmos, Hans Jørn; Frimodt-Møller, Niels

    2002-01-01

    Bacteremia with beta-hemolytic Streptococci groups A, B, C and G has a mortality rate of approximately 20%. In this study we analyzed the association of various patient risk factors with mortality. Records from 241 patients with beta-hemolytic streptococcal bacteremia were reviewed with particular...... attention to which predisposing factors were predictors of death. A logistic regression model found age, burns, immunosuppressive treatment and iatrogenic procedures prior to the infection to be significant predictors of death, with odds ratios of 1.7 (per decade), 19.7, 3.6 and 6.8, respectively...

  20. The Beta Transmuted Weibull Distribution

    Directory of Open Access Journals (Sweden)

    Manisha Pal

    2014-06-01

    Full Text Available The paper introduces a beta transmuted Weibull distribution, which contains a number ofdistributions as special cases. The properties of the distribution are discussed and explicit expressions are derived for the mean deviations, Bonferroni and Lorenz curves, and reliability. The distribution and moments of order statistics are also studied. Estimation of the model parameters by the method of maximum likelihood is discussed. The log beta transmuted Weibull model is introduced to analyze censored data. Finally, the usefulness of the new distribution in analyzing positive data is illustrated.

  1. Beta activity of enriched uranium

    International Nuclear Information System (INIS)

    Nambiar, P.P.V.J.; Ramachandran, V.

    1975-01-01

    Use of enriched uranium as reactor fuel necessitates its handling in various forms. For purposes of planning and organising radiation protection measures in enriched uranium handling facilities, it is necessary to have a basic knowledge of the radiation status of enriched uranium systems. The theoretical variations in beta activity and energy with U 235 enrichment are presented. Depletion is considered separately. Beta activity build up is also studied for two specific enrichments, in respect of which experimental values for specific alpha activity are available. (author)

  2. A {beta} - {gamma} coincidence; Metodo de coincidencias {beta} - {gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Agullo, F

    1960-07-01

    A {beta} - {gamma} coincidence method for absolute counting is given. The fundamental principles are revised and the experimental part is detailed. The results from {sup 1}98 Au irradiated in the JEN 1 Swimming pool reactor are given. The maximal accuracy is 1 per cent. (Author) 11 refs.

  3. N-Benzylhydroxylamine addition to beta-aryl enoates. Enantioselective synthesis of beta-aryl-beta-amino acid precursors

    Science.gov (United States)

    Sibi; Liu

    2000-10-19

    Chiral Lewis acid catalyzed N-benzylhydroxylamine addition to pyrrolidinone-derived enoates afforded beta-aryl-beta-amino acid derivatives in high enantiomeric purity with moderate to very good chemical efficiency.

  4. Supra-transmission and bistability in nonlinear media with a photonic and electronic forbidden band gap; Supratransmission et bistabilite nonlineaire dans les milieux a bandes interdites photoniques et electroniques

    Energy Technology Data Exchange (ETDEWEB)

    Chevriaux, D

    2007-06-15

    We study wave scattering in different nonlinear media possessing a natural forbidden band gap. In particular, we show the existence of a bistable behavior in media governed by the sine-Gordon equation (short pendular chain, Josephson junction array, quantum Hall bilayer), or the nonlinear Schroedinger equation (Kerr and Bragg media), in discrete and continuous models. These different media are submitted to periodic boundary conditions with a frequency in the forbidden band gap and an amplitude that determines their stability states. Indeed, for a sufficient amplitude (supra-transmission), the medium switches from reflector to transmitter, hence allowing the output signal to jump from evanescent to large values. We give a complete analytical description of the bistability that allows to understand the different stationary states observed and to predict the switch of one state to the other. (author)

  5. Phase transitions in the $sdg$ interacting boson model

    OpenAIRE

    Van Isacker, P.; Bouldjedri, A.; Zerguine, S.

    2009-01-01

    19 pages, 5 figures, submitted to Nuclear Physics A; A geometric analysis of the $sdg$ interacting boson model is performed. A coherent-state is used in terms of three types of deformation: axial quadrupole ($\\beta_2$), axial hexadecapole ($\\beta_4$) and triaxial ($\\gamma_2$). The phase-transitional structure is established for a schematic $sdg$ hamiltonian which is intermediate between four dynamical symmetries of U(15), namely the spherical ${\\rm U}(5)\\otimes{\\rm U}(9)$, the (prolate and ob...

  6. Natural widths and Coster-Kronig transitions of L X-ray spectra in elements between Pd and Sb

    International Nuclear Information System (INIS)

    Sakakura, Shusuke; Oohashi, Hirofumi; Ito, Yoshiaki; Tochio, Tatsunori; Vlaicu, Aurel M.; Yoshikawa, Hideki; Ikenaga, Eiji; Kobayashi, Keisuke

    2006-01-01

    The Lα and Lβ X-ray emission spectra in the elements between Pd (Z=46) and Sb (Z=51) were measured using a high-resolution double-crystal vacuum spectrometer. The relative intensities of satellite structures, which originate in L 1 L 3 M 4,5 Coster-Kronig transitions, were estimated to that of each diagram line, and compared with calculated values. According to the work of Chen et al. [1977a. Theoretical L-shell Coster-Kronig energies 11≤Z≤103. At. Data Nucl. Data Tables 19, 97-151], Salgueiro et al. [1987. J. Phys. (Paris) 48 Colloq. C9, 609] and Vlaicu et al. [1998. Investigation of the 74W L emission spectra and satellites. Phys. Rev. A 58, 3544] L 1 L 3 M 4 Coster-Kronig transition is forbidden for 50≤Z≤77, and L 1 L 3 M 5 Coster-Kronig transition is forbidden for 50≤Z≤73. The results suggest that L 1 L 3 M 4,5 Coster-Kronig transitions may be allowed even for Sn (Z=50) and Sb (Z=51)

  7. $\\beta$-decay studies using total-absorption spectroscopy

    CERN Document Server

    Algora, A; García-Borge, M J; Cano-Ott, D; Collatz, R; Courtin, S; Dessagne, P; Fraile-Prieto, L M; Gadea, A; Gelletly, W; Hellström, M; Janas, Z; Jungclaus, A; Kirchner, R; Karny, M; Le Scornet, G; Miehé, C; Maréchal, F; Moroz, F; Nacher, E; Poirier, E; Roeckl, E; Rubio, B; Rykaczewski, K; Taín, J L; Tengblad, O; Wittmann, V

    2004-01-01

    $\\beta$-decay experiments are a primary source of information for nuclear-structure studies and at the same time complementary to in- beam investigations of nuclei far from stability. Although both types of experiment are mainly based on $\\gamma$-ray spectroscopy, they face different experimental problems. The so-called " Pandemonium effect " is a critical problem in $\\beta$-decay if we are to test theoretically calculated transition probabilities. In this contribution we will present a solution to this problem using total absorption spectroscopy methods. We will also present some examples of experiments carried out with the Total Absorption Spectrometer (TAS) at GSI and describe a new device LUCRECIA recently installed at CERN.

  8. Electret dosemeter for beta radiation

    International Nuclear Information System (INIS)

    Campos, L.L.; Caldas, L.V.E.; Mascarenhas, S.

    The response characteristics of an electret dosemeter for beta radiation are studied. Experiments were performed using different geometries and walls, and it was verified for which geometry the dosemeter sensitivity is greater. Sources of 90 Sr - 90 Y, 204 Tl and 85 Kr were used in the experiments. (I.C.R.) [pt

  9. Personnel monitoring for beta rays

    International Nuclear Information System (INIS)

    Piesch, E.; Johns, T.F.

    1983-01-01

    The practical considerations which have to be taken into account in the design of personnel monitors intended to measure doses resulting from exposure to beta rays are discussed. These include the measurement of doses in situations involving either fairly uniform or non-uniform irradiation and of doses to the male gonads. (UK)

  10. Constraining neutrinoless double beta decay

    International Nuclear Information System (INIS)

    Dorame, L.; Meloni, D.; Morisi, S.; Peinado, E.; Valle, J.W.F.

    2012-01-01

    A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). We show how these theories may constrain the absolute scale of neutrino mass, leading in most of the cases to a lower bound on the neutrinoless double beta decay effective amplitude.

  11. Beta Cell Workshop 2013 Kyoto

    DEFF Research Database (Denmark)

    Heller, R Scott; Madsen, Ole D; Nielsen, Jens Høiriis

    2013-01-01

    The very modern Kyoto International Conference Center provided the site for the 8th workshop on Beta cells on April 23-26, 2013. The preceding workshops were held in Boston, USA (1991); Kyoto, Japan (1994); Helsingør, Denmark (1997); Helsinki, Finland (2003); El Perello, Spain (2006); Peebles...

  12. Beta calibration and dosimetry at IPEN

    International Nuclear Information System (INIS)

    Caldas, L.V.E.

    1983-01-01

    A commercial extrapolation chamber (PTW, Germany) was tested in different beta radiation fields and its properties investigated. Its usefullness for beta radiation calibration and dosimetry was demonstrated. (Author) [pt

  13. The Magnetically-Tuned Transition-Edge Sensor

    Science.gov (United States)

    Sadleir, John E.; Lee, Sang-Jun; Smith, Stephen J.; Busch, Sarah E.; Bandler, Simon R.; Adams, Joseph S.; Eckart, Megan E.; Chevenak, James A.; Kelley, Richard L.; Kilbourne, Caroline A.; hide

    2014-01-01

    We present the first measurements on the proposed magnetically-tuned superconducting transition-edge sensor (MTES) and compare the modified resistive transition with the theoretical prediction. A TES's resistive transition is customarily characterized in terms of the unit less device parameters alpha and beta corresponding to the resistive response to changes in temperature and current respectively. We present a new relationship between measured IV quantities and the parameters alpha and beta and use these relations to confirm we have stably biased a TES with negative beta parameter with magnetic tuning. Motivated by access to this new unexplored parameter space, we investigate the conditions for bias stability of a TES taking into account both self and externally applied magnetic fields.

  14. Shear induced phase transitions induced in edible fats

    Science.gov (United States)

    Mazzanti, Gianfranco; Welch, Sarah E.; Marangoni, Alejandro G.; Sirota, Eric B.; Idziak, Stefan H. J.

    2003-03-01

    The food industry crystallizes fats under different conditions of temperature and shear to obtain products with desired crystalline phases. Milk fat, palm oil, cocoa butter and chocolate were crystallized from the melt in a temperature controlled Couette cell. Synchrotron x-ray diffraction studies were conducted to examine the role of shear on the phase transitions seen in edible fats. The shear forces on the crystals induced acceleration of the alpha to beta-prime phase transition with increasing shear rate in milk fat and palm oil. The increase was slow at low shear rates and became very strong above 360 s-1. In cocoa butter the acceleration between beta-prime-III and beta-V phase transition increased until a maximum of at 360 s-1, and then decreased, showing competition between enhanced heat transfer and viscous heat generation.

  15. $\\beta$ - decay asymmetry in mirror nuclei: A = 9

    CERN Multimedia

    Axelsson, L E; Smedberg, M

    2002-01-01

    Investigations of light nuclei close to the drip lines have revealed new and intriguing features of the nuclear structure. The occurrence of halo structures in loosely bound systems has had a great impact on the nuclear physics research in the last years. As intriguing but not yet solved is the nature of transitions with very large $\\beta$ - strength. \\\\ \\\\We report here on the investigation of this latter feature by an accurate measurement of the $\\beta$ - decay asymmetry between the mirror nuclei in the A=9 mass chain.\\\\ \\\\The possible asymmetry for the decay to the states around 12 MeV is interesting not only due to the fact that the individual B$_{GT}$ values are large (with large overlap in wave-functions, an unambiguous interpretation is much easier made), but also due to the special role played by this transition for the $^{9}$Li decay. It seems to belong to a class of high-B$_{GT}$ transitions observed at the neutron drip line and has been suggested to be due either to a lowering of the giant Gamow-Te...

  16. Beta1 integrins regulate chondrocyte rotation, G1 progression, and cytokinesis

    DEFF Research Database (Denmark)

    Aszodi, Attila; Hunziker, Ernst B; Brakebusch, Cord

    2003-01-01

    Beta1 integrins are highly expressed on chondrocytes, where they mediate adhesion to cartilage matrix proteins. To assess the functions of beta1 integrin during skeletogenesis, we inactivated the beta1 integrin gene in chondrocytes. We show here that these mutant mice develop a chondrodysplasia...... of various severity. beta1-deficient chondrocytes had an abnormal shape and failed to arrange into columns in the growth plate. This is caused by a lack of motility, which is in turn caused by a loss of adhesion to collagen type II, reduced binding to and impaired spreading on fibronectin, and an abnormal F......-actin organization. In addition, mutant chondrocytes show decreased proliferation caused by a defect in G1/S transition and cytokinesis. The G1/S defect is, at least partially, caused by overexpression of Fgfr3, nuclear translocation of Stat1/Stat5a, and up-regulation of the cell cycle inhibitors p16 and p21...

  17. Double beta decay and majorana neutrinos. Right-handed currents or nonzero masses

    International Nuclear Information System (INIS)

    Rosen, S.P.; Perlmutter, A.

    1981-01-01

    This chapter describes some new developments concerning the mechanism for lepton number nonconservation in no-neutrino double beta decay. Explains that lepton number nonconservation in no-neutrino double beta decay comes about either because both left- and right-handed components of a Majorano neutrino are coupled to the electron in the weak leptonic current, or because the neutrino has nonzero mass. Shows that while nuclear ground-state to ground-state transitions arise from right-handed currents and from neutrino mass terms, transitions to low-lying excited states with J /SUP P/ =2 + can arise only from right-handed currents. Emphasizes that the possibilities of detecting small admixtures of right-handed currents, and of setting limits on neutrino masses that are either very small or very large, make double beta decay a most rewarding phenomenon to study

  18. Study of 193Os beta- decay

    International Nuclear Information System (INIS)

    Zahn, Guilherme Soares

    2006-01-01

    In this work, the excited levels of 193 Ir populated by the beta - decay of 193 Os (T 1/2 ∼ 30h) were investigated. For that purpose, ∼ 5 mg samples of 99%-enriched 192 Os were irradiated under a thermal neutron flux of ∼ 10 12 s -1 and then analysed both using single gamma spectroscopy and a 4-detector multi parametric acquisition facility, which provided data for both a gamma gamma coincidence analysis and a directional angular correlation gamma gamma (θ ) study. From these data, 28 transitions were added to this decay scheme, 11 of which were previously known from nuclear reactions and 17 observed for the first time. Eight excited levels were also added to the decay scheme, 3 of which were known from nuclear reaction studies - the remaining 5 are suggested for the first time. Moreover, it was possible to confirm suspicions found in reference that the levels at 848.93 keV and 849.093 keV are indeed the same; it was also possible to confirm the existence of an excited level at 806.9 keV, which had been inferred, but not experimentally confirmed in beta decay studies to date. The angular correlation analysis allowed for the definition of the spin of the excited level at 874 keV as 5/2 +; moreover, the results showed a 79% probability that the spin of the 1078 keV level is 5/2/'-, and also restricted the spin possibilities for the new excited level at 960 keV to two values (1/2 or 3/2). It was also possible to measure the multipolarity mixing ratio (δ Ln+1 /L n ) for 43 transitions - 19 of them for the first time and most of the others with a better precision than previously known. Finally, an attempt was made to understand the low-lying levels structure for this nucleus using a theoretical model, which reproduced the ground state and the two lowest-lying excited levels in 193 Ir. (author)

  19. On Fuzzy {beta}-I-open sets and Fuzzy {beta}-I-continuous functions

    Energy Technology Data Exchange (ETDEWEB)

    Keskin, Aynur [Department of Mathematics, Faculty of Science and Arts, Selcuk University, Campus, 42075 Konya (Turkey)], E-mail: akeskin@selcuk.edu.tr

    2009-11-15

    In this paper, first of all we obtain some properties and characterizations of fuzzy {beta}-I-open sets. After that, we also define the notion of {beta}-I-closed sets and obtain some properties. Lastly, we introduce the notions of fuzzy {beta}-I-continuity with the help of fuzzy {beta}-I-open sets to obtain decomposition of fuzzy continuity.

  20. Beta-Catenin Stability in Breast Cancer

    National Research Council Canada - National Science Library

    Baswaran, Vijay

    1999-01-01

    .... beta-catenin also binds the adenomatous polyposis coli protein (APC). The tumor suppressor function of APC is suggested to depend in part on its ability to bind beta-catenin and to facilitate beta-catenin degradation by an unknown mechanism...

  1. Beta-lactamases in Enterobacteriaceae in broilers

    NARCIS (Netherlands)

    Dierikx, C.M.

    2013-01-01

    Resistance to cephalosprins due to the production of extended spectrum beta-lactamases (ESBLs) or plasmid mediated AmpC beta-lactamases is increasingly found in infections in humans outside the hospital. The genes encoding for these beta-lactamases are located on mobile DNA (plasmids), which can be

  2. Insulin-producing cells generated from dedifferentiated human pancreatic beta cells expanded in vitro.

    Directory of Open Access Journals (Sweden)

    Holger A Russ

    Full Text Available Expansion of beta cells from the limited number of adult human islet donors is an attractive prospect for increasing cell availability for cell therapy of diabetes. However, attempts at expanding human islet cells in tissue culture result in loss of beta-cell phenotype. Using a lineage-tracing approach we provided evidence for massive proliferation of beta-cell-derived (BCD cells within these cultures. Expansion involves dedifferentiation resembling epithelial-mesenchymal transition (EMT. Epigenetic analyses indicate that key beta-cell genes maintain open chromatin structure in expanded BCD cells, although they are not transcribed. Here we investigated whether BCD cells can be redifferentiated into beta-like cells.Redifferentiation conditions were screened by following activation of an insulin-DsRed2 reporter gene. Redifferentiated cells were characterized for gene expression, insulin content and secretion assays, and presence of secretory vesicles by electron microscopy. BCD cells were induced to redifferentiate by a combination of soluble factors. The redifferentiated cells expressed beta-cell genes, stored insulin in typical secretory vesicles, and released it in response to glucose. The redifferentiation process involved mesenchymal-epithelial transition, as judged by changes in gene expression. Moreover, inhibition of the EMT effector SLUG (SNAI2 using shRNA resulted in stimulation of redifferentiation. Lineage-traced cells also gave rise at a low rate to cells expressing other islet hormones, suggesting transition of BCD cells through an islet progenitor-like stage during redifferentiation.These findings demonstrate for the first time that expanded dedifferentiated beta cells can be induced to redifferentiate in culture. The findings suggest that ex-vivo expansion of adult human islet cells is a promising approach for generation of insulin-producing cells for transplantation, as well as basic research, toxicology studies, and drug

  3. Pressure effect on the electrical conductivity and superconductivity of beta-(BDA-TTP)2I3.

    Science.gov (United States)

    Yamada, Jun-Ichi; Fujimoto, Kazuya; Akutsu, Hiroki; Nakatsuji, Shin'ichi; Miyazaki, Akira; Aimatsu, Masashi; Kudo, Satoshi; Enoki, Toshiaki; Kikuchi, Koichi

    2006-03-28

    The pressure-induced electrical conductivity properties of beta-(BDA-TTP)2I3 have been investigated; the salt exhibits a dramatic change in the conductivity behaviour above ca. 10 kbar and undergoes a superconducting transition with an onset near 10 K.

  4. Forbidden word entropy of cerebral oximetric values predicts postoperative neurocognitive decline in patients undergoing aortic arch surgery under deep hypothermic circulatory arrest

    Directory of Open Access Journals (Sweden)

    Anna Dubovoy

    2017-01-01

    Full Text Available Purpose: Up to 53% of cardiac surgery patients experience postoperative neurocognitive decline. Cerebral oximetry is designed to detect changes in cerebral tissue saturation and therefore may be useful to predict which patients are at risk of developing neurocognitive decline. Methods: This is a retrospective analysis of a prospective study originally designed to determine if treatment of cerebral oximetry desaturation is associated with improvement in postoperative cognitive dysfunction in patients undergoing aortic reconstruction under deep hypothermic circulatory arrest. Cognitive function was measured, preoperatively and 3 months postoperatively, with 15 neuropsychologic tests administered by a psychologist; the individual test scores were summed and normalized. Bilateral cerebral oximetry data were stored and analyzed using measures of entropy. Cognitive decline was defined as any decrease in the summed normalized score from baseline to 3 months. Results: Seven of 17 (41% patients suffered cognitive decline. There was no association between baseline cerebral oximetry and postoperative cognitive dysfunction. Nor were changes in oximetry values associated with cognitive decline. However, cognitive decline was associated with loss of forbidden word entropy (FwEn (correlation: Rho ρ = 0.51, P = 0.037 for left cerebral oximetry FwEn and ρ = 0.54, P = 0.025 for right cerebral oximetry FwEn. Conclusion: Postoperative cognitive decline was associated with loss of complexity of the time series as shown by a decrease in FwEn from beginning to end of the case. This suggests that regulation of cerebral oximetry is different between those who do and those who do not develop cognitive decline.

  5. Development and applications of beta and near beta titanium alloys

    International Nuclear Information System (INIS)

    Takemura, A.; Ohyama, H.; Nishimura, T.; Abumiya, T.

    1993-01-01

    In this report the authors introduced application of beta and near beta titanium alloys also development and processing of these alloys at Kobe Steel LTD. Ti-15Mo-5Zr-3Al is an alloy developed by Kobe Steel which has been applied for variety of sporting goods, also used as an erosion shield of steam turbine blades. Ti-15Mo-5Zr-3Al high strength wire for valve springs is under development. New beta alloys(Ti-V-Nb-Sn-Al) are under development which have lower flow stress at room temperature than Ti 15V-3Cr-3Sn-3Al, expected to improve productivity of cold forging. NNS forging and thermo mechanical treatment of Ti-10V-2Fe-3Al were studied. Ti-10V-2Fe3Al steam turbine blades and structural parts for aircraft were developed. Fine grain cold strips of Ti 15V-3Cr-3Sn-3Al are produced by annealing and pickling process. These cold strips are used for parts of a fishing rod

  6. PGC-1alpha and PGC-1beta have both similar and distinct effects on myofiber switching toward an oxidative phenotype

    DEFF Research Database (Denmark)

    Mortensen, Ole Hartvig; Frandsen, Lis; Schjerling, Peter

    2006-01-01

    Peroxisome proliferator-activated receptor-gamma coactivator-1alpha and -1beta (PGC-1alpha and PGC-1beta) were overexpressed by adenovirus-mediated gene transfer in cultures of primary rat skeletal muscle cells derived from neonatal myoblasts. Effects on muscle fiber type transition and metabolism...... an increase in the mRNA expression of TRB3, a negative regulator of insulin signaling. These results show that both PGC-1alpha and PGC-1beta are involved in the regulation of skeletal muscle fiber transition and metabolism and that they have both overlapping and differing effects....... were studied from days 5 to 22 of culture. PGC-1alpha and PGC-1beta overexpression caused a three- to fourfold increase in mRNA level, a doubling of enzymatic activity of citrate synthase, a slight increase in short-chain acyl-CoA dehydrogenase mRNA, a doubling of the mRNA level, and a 30-50% increase...

  7. Low level GAMMA0 spectrometry by beta-gamma coincidence

    International Nuclear Information System (INIS)

    Grigorescu, E.L.; Luca, A.; Razdolescu, A.C.; Ivan, C.

    1999-01-01

    Low level gamma spectrometry has a wide application, especially in environmental monitoring. Two variants, based on a beta-gamma coincidence technique, were studied. The equipment was composed of a beta detector and a Ge(Li) gamma detector (6% - relative efficiency), with the associated electronics. The gamma rays are recorded by the multichannel analyzer (4096 channels) only if the associated beta particles, which precede the gamma transitions, are registered in coincidence. Two types of beta detectors were used: plastic and liquid scintillators. In both cases, an external lead shield of 5 cm thick was used. The integral gamma background (50-1700 KeV) was reduced about 85 and 50 times, respectively. The corresponding MDA (Minimum Detectable Activity) values decreased about 1.5 and (3-7) times, respectively. The 2π sr plastic beta detector was placed on top the Ge(Li). The sample was inserted between the two detectors. The measurement time was 10 4 s. A 4π sr detector, built of the same material, was also studied, but it proved to be less advantageous because the background was reduced only 16 times; for a MDA reduction similar with that of the 2π sr variant, a longer measurement was needed (3.10 4 s). The other type of beta detector used, was a liquid scintillator. The dissolving of the samples in scintillator ensures a 4π sr measurement geometry. The vials with scintillator (10 ml volume) were placed on top the Ge(Li) and visualised by the photocathode of a phototube. This setup was surrounded by an enclosure which prevent the light penetration. The measurement time was 10 4 s. The only difficulty encountered in this low level measurement method is the accurate determination of the beta efficiency. A limitation is the possibility to measure only small mass samples. These variants are more simple and cheaper than others, previously studied. The advantage of the method is obvious when, instead of low MDA values, shorter measurement times are preferred. The

  8. Gamow-Teller beta decay of proton-rich nuclei

    International Nuclear Information System (INIS)

    Klepper, O.; Rykaczewski, K.

    1990-11-01

    The beta decays of 48 Mn and of even-even nuclei near the double shell-closures at 100 Sn and 146 Gd are currently investigated at the GSI on-line mass separator. Their Gamow-Teller strength are surveyed in their present experimental status, together with related results from the ISOLDE (CERN) and ISOCELE (Orsay) separators, and are compared with predictions from different nuclear models. The strength of the 0 + → 1 + Gamow-Teller transitions is compiled in tables and graphs. (orig.)

  9. Beta genus papillomaviruses and skin cancer.

    Science.gov (United States)

    Howley, Peter M; Pfister, Herbert J

    2015-05-01

    A role for the beta genus HPVs in keratinocyte carcinoma (KC) remains to be established. In this article we examine the potential role of the beta HPVs in cancer revealed by the epidemiology associating these viruses with KC and supported by oncogenic properties of the beta HPV proteins. Unlike the cancer associated alpha genus HPVs, in which transcriptionally active viral genomes are invariably found associated with the cancers, that is not the case for the beta genus HPVs and keratinocyte carcinomas. Thus a role for the beta HPVs in KC would necessarily be in the carcinogenesis initiation and not in the maintenance of the tumor. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Alpha and beta detection and spectrometry

    International Nuclear Information System (INIS)

    Saro, S.

    1984-01-01

    The theory of alpha and beta radioactive decay, the interaction of alpha and beta particles with matter, and their detection and spectrometry are dealt with in seven chapters: 1. Alpha transformation of atomic nuclei; 2. Basic properties of detectors and statistics of detection; 3. Alpha detectors and spectrometers; 4. Applications of alpha detection and spectrometry; 5. Beta transformation of atomic nuclei; 6. Beta particle detectors and spectrometers; 7. Detection of low energy beta particles. Chapter 8 is devoted to sampling and preparation of samples for radiometry. (E.F.)

  11. Antibodies against chromosomal beta-lactamase

    DEFF Research Database (Denmark)

    Giwercman, B; Rasmussen, J W; Ciofu, Oana

    1994-01-01

    A murine monoclonal anti-chromosomal beta-lactamase antibody was developed and an immunoblotting technique was used to study the presence of serum and sputum antibodies against Pseudomonas aeruginosa chromosomal group 1 beta-lactamase in patients with cystic fibrosis (CF). The serum antibody...... 1 cephalosporinase. We found a wide range of chromosomal beta-lactamase activity in the sputum samples, with no correlation with basal or induced activity of beta-lactamase expression. The presence of anti-beta-lactamase antibodies in endobronchial sputum could be an important factor in the defense...

  12. Application of inverse models and XRD analysis to the determination of Ti-17 {beta}-phase coefficients of thermal expansion

    Energy Technology Data Exchange (ETDEWEB)

    Freour, S. [GeM, Institut de Recherche en Genie Civil et Mecanique (UMR CNRS 6183), Universite de Nantes, Ecole Centrale de Nantes, 37 Boulevard de l' Universite, BP 406, 44 602 Saint-Nazaire cedex (France)]. E-mail: freour@crttsn.univ-nantes.fr; Gloaguen, D. [GeM, Institut de Recherche en Genie Civil et Mecanique (UMR CNRS 6183), Universite de Nantes, Ecole Centrale de Nantes, 37 Boulevard de l' Universite, BP 406, 44 602 Saint-Nazaire cedex (France); Francois, M. [Laboratoire des Systemes Mecaniques et d' Ingenierie Simultanee (LASMIS FRE CNRS 2719), Universite de Technologie de Troyes, 12 Rue Marie Curie, BP 2060, 10010 Troyes (France); Guillen, R. [GeM, Institut de Recherche en Genie Civil et Mecanique (UMR CNRS 6183), Universite de Nantes, Ecole Centrale de Nantes, 37 Boulevard de l' Universite, BP 406, 44 602 Saint-Nazaire cedex (France)

    2006-04-15

    scope of this work is the determination of the coefficients of thermal expansion of the Ti-17 {beta}-phase. A rigorous inverse thermo-elastic self-consistent scale transition micro-mechanical model extended to multi-phase materials was used. The experimental data required for the application of the inverse method were obtained from both the available literature and especially dedicated X-ray diffraction lattice strain measurements performed on the studied ({alpha} + {beta}) two-phase titanium alloy.

  13. Forbidden immisions and environmental protection

    Directory of Open Access Journals (Sweden)

    Popov Danica

    2012-01-01

    Full Text Available In the Serbian Law and in the most of jurisdictions, there are limits on exercising the right of property. A real estate owner must refrain from activities by which the use of other real estate is being imploded through the emission of excessive gasses, vapors, smoke, heat, noise, the draining of waste water, etc. Neighboring real estate owners must endure such harmful effects if they do not exceed the limit of usual endurance, taking into account the nature and purpose of such real estate, as well as local conditions. The property owner who is affected by emissions exceeding the set limit, has the right to request a stop of emissions which exceeded the allowed volume of emissions. If the imissions originate from some industrial plants, within the activity allowed by a state authority, one cannot request a cessation of such activities, but can simply seek damages. The issue of the environmental protection in the Republic of Serbia is regulated by a number of particular substantive laws, with a Law of environmental protection of 2009. as fundamental Law.

  14. DMPD: Immunoreceptor-like signaling by beta 2 and beta 3 integrins. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17913496 Immunoreceptor-like signaling by beta 2 and beta 3 integrins. Jakus Z, Fod...) Show Immunoreceptor-like signaling by beta 2 and beta 3 integrins. PubmedID 17913496 Title Immunoreceptor-...like signaling by beta 2 and beta 3 integrins. Authors Jakus Z, Fodor S, Abram CL

  15. Experiments close to the beta-limit in W7-AS

    International Nuclear Information System (INIS)

    Weller, A; Geiger, J; Werner, A; Zarnstorff, M C; Nuehrenberg, C; Sallander, E; Baldzuhn, J; Brakel, R; Burhenn, R; Dinklage, A; Fredrickson, E; Gadelmeier, F; Giannone, L; Grigull, P; Hartmann, D; Jaenicke, R; Klose, S; Knauer, J P; Koenies, A; Kolesnichenko, Ya I; Laqua, H P; Lutsenko, V V; McCormick, K; Monticello, D; Osakabe, M; Pasch, E; Reiman, A; Rust, N; Spong, D A; Wagner, F; Yakovenko, Yu V

    2003-01-01

    A major objective of the experimental program in the last phase of the W7-AS stellarator was to explore and demonstrate the high-beta performance of advanced stellarators. MHD-quiescent discharges at low impurity radiation levels with volume averaged beta-values of up to beta=3.4% have been achieved. A very important prerequisite was the attainment of the high density H-Mode (HDH) regime. This was made possible by the installation of extensive graphite plasma facing components designed for island divertor operation. The co-directed neutral beam injection provided increased absorbed heating power of up to 3.2 MW in high-beta plasmas with B<=1.25 T. The anticipated improved features concerning equilibrium and stability at high plasma beta could be verified experimentally by the comparison of x-ray data with free boundary equilibrium calculations. The maximum beta found in configurations with a rotational transform around t=0.5 is determined by the available heating power. No evidence of a stability limit has been found in the accessible configuration space, and the discharges are remarkably quiescent at maximum beta, most likely due the increase of the magnetic well depth. An increase in low m/n MHD activity is typically observed during the transition towards high beta. The beneficial stability properties of net-current-free configurations could be demonstrated by comparison with configurations where a significant inductive current drive was involved. Current driven instabilities such as tearing modes and soft disruptions can prevent access to beta-values as high as in the currentless case. The experimental results indicate that optimized stellarators such as W7-X can be considered as a viable option for an attractive stellarator fusion reactor

  16. Beta Cell Mass Restoration in Alloxan-Diabetic Mice Treated with EGF and Gastrin.

    Directory of Open Access Journals (Sweden)

    Imane Song

    Full Text Available One week of treatment with EGF and gastrin (EGF/G was shown to restore normoglycemia and to induce islet regeneration in mice treated with the diabetogenic agent alloxan. The mechanisms underlying this regeneration are not fully understood. We performed genetic lineage tracing experiments to evaluate the contribution of beta cell neogenesis in this model. One day after alloxan administration, mice received EGF/G treatment for one week. The treatment could not prevent the initial alloxan-induced beta cell mass destruction, however it did reverse glycemia to control levels within one day, suggesting improved peripheral glucose uptake. In vitro experiments with C2C12 cell line showed that EGF could stimulate glucose uptake with an efficacy comparable to that of insulin. Subsequently, EGF/G treatment stimulated a 3-fold increase in beta cell mass, which was partially driven by neogenesis and beta cell proliferation as assessed by beta cell lineage tracing and BrdU-labeling experiments, respectively. Acinar cell lineage tracing failed to show an important contribution of acinar cells to the newly formed beta cells. No appearance of transitional cells co-expressing insulin and glucagon, a hallmark for alpha-to-beta cell conversion, was found, suggesting that alpha cells did not significantly contribute to the regeneration. An important fraction of the beta cells significantly lost insulin positivity after alloxan administration, which was restored to normal after one week of EGF/G treatment. Alloxan-only mice showed more pronounced beta cell neogenesis and proliferation, even though beta cell mass remained significantly depleted, suggesting ongoing beta cell death in that group. After one week, macrophage infiltration was significantly reduced in EGF/G-treated group compared to the alloxan-only group. Our results suggest that EGF/G-induced beta cell regeneration in alloxan-diabetic mice is driven by beta cell neogenesis, proliferation and recovery of

  17. Diffusion of Hydrogen in the beta-Phase of Pd-H Studied by Small Energy Transfer Neutron Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Nelin, G; Skoeld, K

    1974-07-01

    The diffusion of hydrogen in beta-PdH has been studied by quasielastic neutron scattering. It is shown that the diffusion occurs through jumps between adjacent octahedral interstitial sites. The observed integrated quasielastic intensities cannot be described by a simple Debye-Waller factor. The phase transition from the beta-phase to the alpha-phase has also been studied. No dramatic changes in the scattering patterns were observed. It is concluded that the diffusion mechanism is remarkably similar between the low concentration alpha-phase and the high concentration beta-phase

  18. Comparisons of experimental beta-ray spectra important to decay heat predictions with ENSDF [Evaluated Nuclear Structure Data File] evaluations

    International Nuclear Information System (INIS)

    Dickens, J.K.

    1990-03-01

    Graphical comparisons of recently obtained experimental beta-ray spectra with predicted beta-ray spectra based on the Evaluated Nuclear Structure Data File are exhibited for 77 fission products having masses 79--99 and 130--146 and lifetimes between 0.17 and 23650 sec. The comparisons range from very poor to excellent. For beta decay of 47 nuclides, estimates are made of ground-state transition intensities. For 14 cases the value in ENSDF gives results in very good agreement with the experimental data. 12 refs., 77 figs., 1 tab

  19. The structure of nuclei far from beta stability

    International Nuclear Information System (INIS)

    Zganjar, E.F.

    1990-01-01

    This report discusses the following topics: shape coexistence, intruder states, and E0 transitions; the Ir isotopes; the Pt isotopes; the Au isotopes; the Hg isotopes; the Tl isotopes; decay properties of 153 Yb and 153 Tm; non-yrast levels structure of 135 Nd via beta decay of 135 Pm; decay of mass-separated 137 Eu and 137 Sm; structure of 130,132 Ce, 132,134 Nd, and 134 Pm; decay of 127 Cs to levels of odd-neutron 127 Xe; level structure of 119 Te; conversion electron spectroscopy in 116 Xe and 126 Xe; signature of the shape coexistence in 72 Kr; identification of transitions in 73 Kr and search for large oblate; high spin states and multiple band structure in 68 Ge; high spin states in 65 Ga and 67 Ga; electron spectroscopy; ion sources; and the on-line nuclear orientation facility

  20. New results for double-beta decay of {sup 100}Mo to excited final states of {sup 100}Ru using the TUNL-ITEP apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Kidd, M.F.; Esterline, J.H. [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Tornow, W. [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)], E-mail: tornow@tunl.duke.edu; Barabash, A.S.; Umatov, V.I. [Institute for Theoretical and Experimental Physics, 117259 Moscow (Russian Federation)

    2009-04-15

    The coincidence detection efficiency of the TUNL-ITEP apparatus designed for measuring half-life times of two-neutrino double-beta (2{nu}{beta}{beta}) decay transitions to excited final states in daughter nuclei has been measured with a factor of 2.4 improved accuracy. In addition, the previous measuring time of 455 days for the study of the {sup 100}Mo 2{nu}{beta}{beta} decay to the first excited 0{sub 1}{sup +} state in {sup 100}Ru has been increased by 450 days, and a new result (combined with the previous measurement obtained with the same apparatus) for this transition is presented: T{sub 1/2}=[5.5{sub -0.8}{sup +1.2}(stat){+-}0.3(syst)]x10{sup 20} yr. Measured 2{nu}{beta}{beta} decay half-life times to excited states can be used to test the reliability of nuclear matrix element calculations needed for determining the effective neutrino mass from zero-neutrino double-beta decay data. We also present new limits for transitions to higher excited states in {sup 100}Ru which, if improved, may be of interest for more exotic conjectures, like a bosonic component to neutrino statistics.

  1. Metalo-beta-lactamases Metallo-beta-lactamases

    Directory of Open Access Journals (Sweden)

    Rodrigo Elisandro Mendes

    2006-04-01

    Full Text Available Nos últimos anos tem sido observada maior incidência de bacilos Gram-negativos resistentes a cefalosporinas de espectro ampliado no ambiente hospitalar, ocasionando, assim, maior uso de betalactâmicos mais potentes, como os carbapenens. A utilização de carbapenens exerce maior pressão seletiva sobre a microbiota hospitalar, o que pode ocasionar aumento da resistência a esses agentes. Entre os mecanismos de resistência a carbapenens mais comumente identificados estão a produção de betalactamases, como, por exemplo, as pertencentes à classe D de Ambler e as que pertencem à classe B de Ambler, ou metalo-beta-lactamases (MbetaL. Essas últimas hidrolisam todos betalactâmicos comercialmente disponíveis, sendo a única exceção o monobactam aztreonam. Desde o início da década de 1990, novos genes que codificam MbetaLs têm sido descritos em microrganismos clinicamente importantes, como Pseudomonas spp., Acinetobacter spp. e membros da família Enterobacteriaceae. O encontro desses microrganismos não-sensíveis a carbapenens pode ser submetido a metodologias fenotípicas para detecção da produção de MbetaL com o intuito de auxiliar a Comissão de Controle de Infecção Hospitalar (CCIH e prevenir a disseminação desses determinantes de resistência, uma vez que genes que codificam MbetaLs estão contidos em estruturas genéticas que propiciam sua mobilidade de forma muito efetiva, sendo então facilmente disseminados.Increase isolation of Gram-negative bacilli resistant to broad-spectrum cephalosporin has been observed during the last few years, thus determining the use of more potent beta-lactams, such as carbapenems. The use of these antimicrobial agents may lead to the emergence of carbapenem resistant Gram-negative bacilli in the nosocomial environment. Carbapenem resistance may be due to the production of Ambler class D beta-lactamase or Ambler class B beta-lactamase, also called metallo-beta-lactamase (MbetaL. Apart from

  2. 20F beta spectrum shape and weak interaction tests

    Science.gov (United States)

    Voytas, Paul; George, Elizabeth; Chuna, Thomas; Naviliat-Cuncic, Oscar; Hughes, Max; Huyan, Xueying; Minamisono, Kei; Paulauskas, Stanley

    2016-09-01

    Precision measurements of the shape of beta spectra can test our understanding of the weak interaction. We are carrying out a measurement of the shape of the energy spectrum of β particles from 20F decay. The primary motivation is to test the so-called strong form of the conserved vector current (CVC) hypothesis. The measurement should also enable us to place competitive limits on the contributions of exotic tensor couplings in beta decay. We aim to achieve a relative precision better than 3% on the linear contribution to the shape. This represents an order of magnitude improvement compared to previous experiments in 20F. In order to control systematic effects, we are using a technique that takes advantage of high energy radioactive beams at the NSCL to implant the decaying nuclei in scintillation detectors deeply enough that the emitted beta particles cannot escape. The β-particle energy is measured with the implantation detector after switching off the implantation beam. Ancillary detectors are used to identify the 1.633-MeV γ-rays following the 20F β decay for coincidence measurements in order to tag the transition of interest and to reduce backgrounds. We report on the status of the analysis. Supported in part with Awards from the NSCL PAC and the National Science Foundation under Grant No. PHY-1506084.

  3. Transit space

    DEFF Research Database (Denmark)

    Raahauge, Kirsten Marie

    2008-01-01

    This article deals with representations of one specific city, Århus, Denmark, especially its central district. The analysis is based on anthropological fieldwork conducted in Skåde Bakker and Fedet, two well-off neighborhoods. The overall purpose of the project is to study perceptions of space...... and the interaction of cultural, social, and spatial organizations, as seen from the point of view of people living in Skåde Bakker and Fedet. The focus is on the city dwellers’ representations of the central district of Århus with specific reference to the concept of transit space. When applied to various Århusian...

  4. Transition region

    International Nuclear Information System (INIS)

    Jordan, C.

    1977-01-01

    The Glossary is designed to be a technical dictionary that will provide solar workers of various specialties, students, other astronomers and theoreticians with concise information on the nature and the properties of phenomena of solar and solar-terrestrial physics. Each term, or group of related terms, is given a concise phenomenological and quantitative description, including the relationship to other phenomena and an interpretation in terms of physical processes. The references are intended to lead the non-specialist reader into the literature. This section deals with: transition region; di-electronic recombination; intersystem or intercombination lines; satellite lines; grazing-incidence optics; and crystal spectrometers. (B.R.H.)

  5. Resistance training & beta-hydroxy-beta-methylbutyrate supplementation on hormones

    Directory of Open Access Journals (Sweden)

    Hamid Arazi

    2015-10-01

    Full Text Available RESUMOIntroduction:In recent years, there was an increased interest on the effects of beta-hydroxy-beta-methylbutyrate (HMB supplementation on skeletal muscle due to its anti-catabolic effects.Objectives:To investigate the effect of HMB supplementation on body composition, muscular strength and anabolic-catabolic hormones after resistance training.Methods:Twenty amateur male athletes were randomly assigned to supplement and control groups in a double-blind crossover design and participated in four weeks resistance training. Before and after the test period fasting blood samples were obtained to determine anabolic (the growth hormone and testosterone and catabolic (cortisol hormones, and fat mass, lean body mass (LBM and muscular strength were measured. Dependent and independent t-tests were used to analyze data.Results:After the training period, there were no significant differen-ces between the groups with respect to fat mass, LBM and anabolic-catabolic hormones. HMB supplementation resulted in a significantly greater strength gain (p≤0.05.Conclusion:Greater increase in strength for HMB group was not accompanied by body composition and basal circulating anabolic-catabolic hormonal changes. It seems that HMB supplementation may have beneficial effects on neurological adaptations of strength gain.

  6. Electrets for beta radiation detection

    International Nuclear Information System (INIS)

    Campos, L.L.; Caldas, L.V.E.; Mascarenhas, S.

    1983-01-01

    Electret dosimetry has been reviewed by Gross. A cylindrical electret ionization-chamber type dosimeter has been studied for X and gamma rays and neutrons. The principle of the dosimeter is electret charge compensation due to ionization in the chamber volume. Electret ionization chambers can be designed with one or more electrets and in various shapes. This study is concerned with a simple system, similar to a cylindrical ionization chamber (sensitive volume: 3,5 cm 3 ) using teflon electrets. Aluminum and lucite were used as wall-materials. Other experiences were performed using chambers without wall, i.e., without defined sensitive volume. The teflon electrets were obtained by Corona discharge in the gas surrounding them. The measurement of the electret charge was made by induction using a co-axial insulated metal chamber connected to an electrometer Keithley 610C. By measuring the charge before and after irradiation it is possible to obtain a calibration curve: charge (Q) versus absorbed dose (D) for the dosimeter. The irradiation setup used was the Beta Secondary Standard System of IPEN calibration laboratory with four beta sources: 90 Sr 90 Y (74 and 1850 MBq), 204 Tl (18,5 MBq) and 147 Pm (518 MBq). In some cases a 85 Kr source was also used. The electrets were tested in different radiation field geometries: electret axis parallel and perpendicular to the field. In conclusion, depending on the wall material and radiation field geometry, the teflon electret detector can be used for different dose interval determinations, using beta radiation

  7. Transitional issues

    International Nuclear Information System (INIS)

    1998-01-01

    This discussion paper, the fifth in the series developed at the IPPSO Market Design Conference, addressed the issue of the need to prevent Ontario Hydro from taking unfair advantage of independent producers and other stakeholders through activities and investments in new power generating capacity in the transitional period leading up to deregulation. The need for controls is predicated on the assumption that the short-term actions and investments of Ontario Hydro could seriously compromise the position of independent generators, and that without such controls the level playing field essential to the operation of a competitive market, does not exist. Various actual and potential actions of Ontario Hydro were discussed, all of which point to the need for strict controls over Ontario Hydro exercising its dominant market power in an unfair way. It was recommended that as a minimum, the provincial government should no longer provide guarantees for Ontario Hydro capital projects, and that Ontario Hydro be instructed to defer any investment on new or returning generating capacity until the new market is in place. Limits could also be placed on Ontario Hydro's marketing efforts to enter into contracts during the transition period, and Ontario Hydro and municipal utilities should be required to keep separate accounts of their commercial preparation, and to settle such accounts separate from ratepayer revenue

  8. Abstraction Mechanisms in the BETA Programming Language

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger

    1983-01-01

    . It is then necessary that the abstraction mechanisms are powerful in order to define more specialized constructs. BETA is an object oriented language like SIMULA 67 ([SIMULA]) and SMALLTALK ([SMALLTALK]). By this is meant that a construct like the SIMULA class/subclass mechanism is fundamental in BETA. In contrast......]) --- covering both data, procedural and control abstractions, substituting constructs like class, procedure, function and type. Correspondingly objects, procedure activation records and variables are all regarded as special cases of the basic building block of program executions: the entity. A pattern thus......The BETA programming language is developed as part of the BETA project. The purpose of this project is to develop concepts, constructs and tools in the field of programming and programming languages. BETA has been developed from 1975 on and the various stages of the language are documented in [BETA...

  9. High-beta linac structures

    International Nuclear Information System (INIS)

    Schriber, S.O.

    1979-01-01

    Accelerating structures for high-beta linacs that have been and are in use are reviewed in terms of their performance. Particular emphasis is given to room-temperature structures and the disk-and-washer structure. The disk-and-washer structure has many attractive features that are discussed for pulsed high-gradient linacs, for 100% duty-cycle medium-gradient linacs and for high-current linacs requiring maximal amounts of stored energy in the electric fields available to the beam

  10. Ionizing radiation predisposes non-malignant human mammaryepithelial cells to undergo TGF beta-induced epithelial to mesenchymaltransition

    Energy Technology Data Exchange (ETDEWEB)

    Andarawewa, Kumari L.; Erickson, Anna C.; Chou, William S.; Costes, Sylvain; Gascard, Philippe; Mott, Joni D.; Bissell, Mina J.; Barcellos-Hoff, Mary Helen

    2007-04-06

    Transforming growth factor {beta}1 (TGF{beta}) is a tumor suppressor during the initial stage of tumorigenesis, but it can switch to a tumor promoter during neoplastic progression. Ionizing radiation (IR), both a carcinogen and a therapeutic agent, induces TGF{beta}, activation in vivo. We now show that IR sensitizes human mammary epithelial cells (HMEC) to undergo TGF{beta}-mediated epithelial to mesenchymal transition (EMT). Non-malignant HMEC (MCF10A, HMT3522 S1 and 184v) were irradiated with 2 Gy shortly after attachment in monolayer culture, or treated with a low concentration of TGF{beta} (0.4 ng/ml), or double-treated. All double-treated (IR+TGF{beta}) HMEC underwent a morphological shift from cuboidal to spindle-shaped. This phenotype was accompanied by decreased expression of epithelial markers E-cadherin, {beta}-catenin and ZO-1, remodeling of the actin cytoskeleton, and increased expression of mesenchymal markers N-cadherin, fibronectin and vimentin. Furthermore, double-treatment increased cell motility, promoted invasion and disrupted acinar morphogenesis of cells subsequently plated in Matrigel{trademark}. Neither radiation nor TGF{beta} alone elicited EMT, even though IR increased chronic TGF{beta} signaling and activity. Gene expression profiling revealed that double treated cells exhibit a specific 10-gene signature associated with Erk/MAPK signaling. We hypothesized that IR-induced MAPK activation primes non-malignant HMEC to undergo TGF{beta}-mediated EMT. Consistent with this, Erk phosphorylation were transiently induced by irradiation, persisted in irradiated cells treated with TGF{beta}, and treatment with U0126, a Mek inhibitor, blocked the EMT phenotype. Together, these data demonstrate that the interactions between radiation-induced signaling pathways elicit heritable phenotypes that could contribute to neoplastic progression.

  11. Theoretical aspects of double beta decay

    International Nuclear Information System (INIS)

    Haxton, W.C.

    1984-01-01

    Considerable effort has been expended recently in theoretical studies of double beta decay. Much of this work has focussed on the constraints this process places on gauge theories of the weak interaction, in general, and on the neutrino mass matrix, in particular. In addition, interesting nuclear structure questions have arisen in studies of double beta decay matrix elements. After briefly reviewing the theory of double beta decay, some of the progress that has been made in these areas is summarized. 25 references

  12. High beta plasmas in the PBX tokamak

    International Nuclear Information System (INIS)

    Bol, K.; Buchenauer, D.; Chance, M.

    1986-04-01

    Bean-shaped configurations favorable for high β discharges have been investigated in the Princeton Beta Experiment (PBX) tokamak. Strongly indented bean-shaped plasmas have been successfully formed, and beta values of over 5% have been obtained with 5 MW of injected neutral beam power. These high beta discharges still lie in the first stability regime for ballooning modes, and MHD stability analysis implicates the external kink as responsible for the present β limit

  13. Spontaneous quaternary and tertiary T-R transitions of human hemoglobin in molecular dynamics simulation.

    Directory of Open Access Journals (Sweden)

    Jochen S Hub

    2010-05-01

    Full Text Available We present molecular dynamics simulations of unliganded human hemoglobin (Hb A under physiological conditions, starting from the R, R2, and T state. The simulations were carried out with protonated and deprotonated HC3 histidines His(beta146, and they sum up to a total length of 5.6 micros. We observe spontaneous and reproducible T-->R quaternary transitions of the Hb tetramer and tertiary transitions of the alpha and beta subunits, as detected from principal component projections, from an RMSD measure, and from rigid body rotation analysis. The simulations reveal a marked asymmetry between the alpha and beta subunits. Using the mutual information as correlation measure, we find that the beta subunits are substantially more strongly linked to the quaternary transition than the alpha subunits. In addition, the tertiary populations of the alpha and beta subunits differ substantially, with the beta subunits showing a tendency towards R, and the alpha subunits showing a tendency towards T. Based on the simulation results, we present a transition pathway for coupled quaternary and tertiary transitions between the R and T conformations of Hb.

  14. Phase Transitions in Algebraic Cluster Models

    International Nuclear Information System (INIS)

    Yepez-Martinez, H.; Cseh, J.; Hess, P.O.

    2006-01-01

    same, and the states are said to form a (soft) band. The phase-transitions, as well as the persistence of the quasidynamical symmetries in the algebraic models of quadrupole collectivity have extensively been studied. In a recent work [1] we have addressed these questions in relation with another important collectivity of nuclei, i.e. clusterization. Two models were considered, a phenomenological one, containing no Pauli-principle, and a semimicroscopic one, which is based on a microscopically determined model space, being free from the Pauli-forbidden states. The interactions were treated in a phenomenologic and algebraic way in both cases. In this respect the two models have a similar group-structure. We have studied the SU(3) - SO(4) phase transition, related to the description of the relative motion in terms of the vibron model (in its simplest form in the phenomenological model and in a properly truncated form in the semimicroscopic description). The analytical study of the large-N limit of both models shows a first order phase transition. We have carried out numerical calculations as well. Three binary cluster systems were chosen, in which the number of open-shell clusters were zero, one and two, respectively. The numerical studies show that the phase transition is smoothed out for finite N systems, but some fingerprints of it still can be seen. The appearance of the quasidynamical SU(3) symmetry has also been studied, when moving away from the limit of the real SU(3) dynamical symmetry. It turned out that in each case, when there is a real dynamical symmetry in the limiting case (in the sense that a well-defined SU(3) quantum number can be associated to a band), this symmetry survives as quasidynamical symmetry at least up to the critical value of the control parameter. (author)

  15. Incorporating beta-turns and a turn mimetic out of context in loop 1 of the WW domain affords cooperatively folded beta-sheets.

    Science.gov (United States)

    Kaul, R; Angeles, A R; Jäger, M; Powers, E T; Kelly, J W

    2001-06-06

    To probe the conformational requirements of loop 1 in the Pin1 WW domain, the residues at the i + 2 and i + 3 positions of a beta-turn within this loop were replaced by dPro-Gly and Asn-Gly, which are known to prefer the conformations required at the i + 1 and i + 2 positions of type II' and type I' beta-turns. Conformational specificity or lack thereof was further examined by incorporating into the i + 2 and i + 3 positions a non-alpha-amino acid-based beta-turn mimetic (4-(2'-aminoethyl)-6-dibenzofuran propionic acid residue, 1), which was designed to replace the i + 1 and i + 2 positions of beta-turns. All these Pin WW variants are monomeric and folded as discerned by analytical ultracentrifugation, NMR, and CD. They exhibit cooperative two-state transitions and display thermodynamic stability within 0.5 kcal/mol of the wild-type WW domain, demonstrating that the acquisition of native structure and stability does not require a specific sequence and, by extension, conformation within loop 1. However, it could be that these loop 1 mutations alter the kinetics of antiparallel beta-sheet folding, which will be addressed by subsequent kinetic studies.

  16. Monitor for alpha beta contamination of hands; Moniteur de contamination alpha beta des mains

    Energy Technology Data Exchange (ETDEWEB)

    Guitton, J

    1958-07-01

    The following specifications of hands alpha beta contamination monitor are presented: the position of the hands, the detection and separation of alpha and beta, the information processing, the programming, the results presentation and general characteristics. (A.L.B.)

  17. Sawtooth crashes at high beta on JET

    Energy Technology Data Exchange (ETDEWEB)

    Alper, B; Huysmans, G T.A.; Sips, A C.C. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Nave, M F.F. [Universidade Tecnica, Lisbon (Portugal). Inst. Superior Tecnico

    1994-07-01

    The sawtooth crashes on JET display features which depend on beta. The main observation is a transient bulging of flux surfaces (duration inferior to 30 microsec.), which is predominantly on the low field side and extends to larger radii as beta increases. This phenomenon reaches the plasma boundary when beta{sub N} exceeds 0.5 and in these cases is followed by an ELM within 50 microsec. These sawtooth/ELM events limit plasma performance. Modelling of mode coupling shows qualitative agreement between observations of the structure of the sawtooth precursor and the calculated internal kink mode at high beta. (authors). 6 refs., 5 figs.

  18. MOPITT Beta Level 1 Radiances V107

    Data.gov (United States)

    National Aeronautics and Space Administration — The MOPITT Beta Level 1 data product consists of the geolocated, calibrated earth scene radiances, associated instrument engineering data summaries, and inflight...

  19. Fabrication of beta particles detector for RMS

    International Nuclear Information System (INIS)

    Lee, W. G.; Kim, Y. G.; Kim, J. B.; Jeong, J. E.; Hong, S. B.

    2003-01-01

    The beta particles detector for RMS (radiation monitoring system) was fabricated to detect charged beta particles. The plastic scintillator was cutted, shaped, polished to make plastic disk for beta particles. The diameter of completed plastic scintillator disk is 40 mm and thickness is 1.5 mm. The mylar film and aluminium foil were used the front of plastic scintillator to intercept light and moisture. The completed plastic detector for RMS consist of the discriminator and counter were made by ULS (Co.). The absolute efficiency of plastic detector was 45.51% for beta particles (Sr/Y - 90)

  20. Random matrix theory for transition strengths: Applications and open questions

    Science.gov (United States)

    Kota, V. K. B.

    2017-12-01

    Embedded random matrix ensembles are generic models for describing statistical properties of finite isolated interacting quantum many-particle systems. A finite quantum system, induced by a transition operator, makes transitions from its states to the states of the same system or to those of another system. Examples are electromagnetic transitions (then the initial and final systems are same), nuclear beta and double beta decay (then the initial and final systems are different) and so on. Using embedded ensembles (EE), there are efforts to derive a good statistical theory for transition strengths. With m fermions (or bosons) in N mean-field single particle levels and interacting via two-body forces, we have with GOE embedding, the so called EGOE(1+2). Now, the transition strength density (transition strength multiplied by the density of states at the initial and final energies) is a convolution of the density generated by the mean-field one-body part with a bivariate spreading function due to the two-body interaction. Using the embedding U(N) algebra, it is established, for a variety of transition operators, that the spreading function, for sufficiently strong interactions, is close to a bivariate Gaussian. Also, as the interaction strength increases, the spreading function exhibits a transition from bivariate Breit-Wigner to bivariate Gaussian form. In appropriate limits, this EE theory reduces to the polynomial theory of Draayer, French and Wong on one hand and to the theory due to Flambaum and Izrailev for one-body transition operators on the other. Using spin-cutoff factors for projecting angular momentum, the theory is applied to nuclear matrix elements for neutrinoless double beta decay (NDBD). In this paper we will describe: (i) various developments in the EE theory for transition strengths; (ii) results for nuclear matrix elements for 130Te and 136Xe NDBD; (iii) important open questions in the current form of the EE theory.

  1. M1 transitions in the (sdg) boson model

    Energy Technology Data Exchange (ETDEWEB)

    Kuyucak, S.; Morrison, I.

    1988-03-03

    Using the 1/N expansion technique we derive expressions for ..beta.. -> g, ..gamma.. -> g and ..gamma.. -> ..gamma.. M1 transitions in a general boson model. The M1 matrix elements in the sdg-boson model are similar in form to those in the neutron-proton IBM. Comparisons are made to some selected M1 data exhibiting collective character.

  2. Neutrinoless Double Beta Decay Experiments

    International Nuclear Information System (INIS)

    Garfagnini, A.

    2014-08-01

    Neutrinoless double beta decay is the only process known so far able to test the neutrino intrinsic nature: its experimental observation would imply that the lepton number is violated by two units and prove that neutrinos have a Majorana mass components, being their own anti-particle. While several experiments searching for such a rare decay have been per- formed in the past, a new generation of experiments using different isotopes and techniques have recently released their results or are taking data and will provide new limits, should no signal be observed, in the next few years to come. The present contribution reviews the latest public results on double beta decay searches and gives an overview on the expected sensitivities of the experiments in construction which will be able to set stronger limits in the near future. EXO and KamLAND-Zen experiments are based on the decay of Xe 136 , GERDA and MAJORANA experiments are based on the decay of Ge 76 , and the CUORE experiment is based on the decay of Te 130

  3. Beta attenuation transmission system (BATS)

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, R.C.; Fullbright, H.J.

    1977-01-01

    The beta attenuation transmission system (BATS) is an automated radiation gauge designed for quantitative measurement of component thickness in explosive detonators. The BATS was designed and built by Group M-1, the Nondestructive Testing Group, of the Los Alamos Scientific Laboratory to measure the areal thickness, in mg/cm/sup 2/, of a cylinder of high explosive (HE) enclosed within a plastic holder. The problem is to determine the density of the HE. A /sup 90/Sr source is collimated by a 0.25 x 1.59-mm slit, and the transmitted beta-particle flux is detected by a plastic scintillator, coupled to a photomultiplier tube. The detonator is transported through the radiation beam by a leadscrew, ballnut, stepping-motor combination. Continuous analog position data are available, derived from the output from a linear-actuated potentiometer attached to the scanner. A linear electrometer amplifies the detected signal, which is then integrated for a preselected time, to obtain the desired statistical accuracy. A microprocessor (..mu..P) is used to control the scanner position and to make the data readings at the assigned positions. The data are stored, and, at the completion of the scan, are processed into the desired format. The final answer is displayed to the operator or output to a peripheral device for permanent record. The characteristics of the radiation source, the collimator, the signal detection and conditioning, and the final results are described in detail. The scanner and the microprocessor control system are briefly outlined.

  4. Beta attenuation transmission system (BATS)

    International Nuclear Information System (INIS)

    Hagan, R.C.; Fullbright, H.J.

    1977-01-01

    The beta attenuation transmission system (BATS) is an automated radiation gauge designed for quantitative measurement of component thickness in explosive detonators. The BATS was designed and built by Group M-1, the Nondestructive Testing Group, of the Los Alamos Scientific Laboratory to measure the areal thickness, in mg/cm 2 , of a cylinder of high explosive (HE) enclosed within a plastic holder. The problem is to determine the density of the HE. A 90 Sr source is collimated by a 0.25 x 1.59-mm slit, and the transmitted beta-particle flux is detected by a plastic scintillator, coupled to a photomultiplier tube. The detonator is transported through the radiation beam by a leadscrew, ballnut, stepping-motor combination. Continuous analog position data are available, derived from the output from a linear-actuated potentiometer attached to the scanner. A linear electrometer amplifies the detected signal, which is then integrated for a preselected time, to obtain the desired statistical accuracy. A microprocessor (μP) is used to control the scanner position and to make the data readings at the assigned positions. The data are stored, and, at the completion of the scan, are processed into the desired format. The final answer is displayed to the operator or output to a peripheral device for permanent record. The characteristics of the radiation source, the collimator, the signal detection and conditioning, and the final results are described in detail. The scanner and the microprocessor control system are briefly outlined

  5. Challenges in Double Beta Decay

    Directory of Open Access Journals (Sweden)

    Oliviero Cremonesi

    2014-01-01

    Full Text Available In the past ten years, neutrino oscillation experiments have provided the incontrovertible evidence that neutrinos mix and have finite masses. These results represent the strongest demonstration that the electroweak Standard Model is incomplete and that new Physics beyond it must exist. In this scenario, a unique role is played by the Neutrinoless Double Beta Decay searches which can probe lepton number conservation and investigate the Dirac/Majorana nature of the neutrinos and their absolute mass scale (hierarchy problem with unprecedented sensitivity. Today Neutrinoless Double Beta Decay faces a new era where large-scale experiments with a sensitivity approaching the so-called degenerate-hierarchy region are nearly ready to start and where the challenge for the next future is the construction of detectors characterized by a tonne-scale size and an incredibly low background. A number of new proposed projects took up this challenge. These are based either on large expansions of the present experiments or on new ideas to improve the technical performance and/or reduce the background contributions. In this paper, a review of the most relevant ongoing experiments is given. The most relevant parameters contributing to the experimental sensitivity are discussed and a critical comparison of the future projects is proposed.

  6. Energy transition

    International Nuclear Information System (INIS)

    Anon.

    2013-01-01

    The yearly environmental conference will hold on September 2013 to evaluate the negotiations led at the national and local levels for december 2012. The government will have then to decide of an energy programming bill which will be submitted to the Parliament at the beginning of the year 2014. 30 main propositions have emerged of the decentralised debates. One of them is the ecological taxation which raise the question of the gas oil and petrol taxation. The current environmental taxes are for almost three quarters of them taxes on energy consumptions and mainly on fossil energies. The Economic, Social and Environmental Council, gives his opinion on the way to find resources to ensure the ecological and energy transition while reducing the public deficit of the State. (O.M.)

  7. Natural polypeptide scaffolds: beta-sheets, beta-turns, and beta-hairpins.

    Science.gov (United States)

    Rotondi, Kenneth S; Gierasch, Lila M

    2006-01-01

    This paper provides an introduction to fundamental conformational states of polypeptides in the beta-region of phi,psi space, in which the backbone is extended near to its maximal length, and to more complex architectures in which extended segments are linked by turns and loops. There are several variants on these conformations, and they comprise versatile scaffolds for presentation of side chains and backbone amides for molecular recognition and designed catalysts. In addition, the geometry of these fundamental folds can be readily mimicked in peptidomimetics. Copyright 2005 Wiley Periodicals, Inc.

  8. Complement activation by the amyloid proteins A beta peptide and beta 2-microglobulin

    DEFF Research Database (Denmark)

    Nybo, Mads; Nielsen, E H; Svehag, S E

    1999-01-01

    component nor heparan sulfate did significantly alter the A beta-induced CA. The results indicate that not only fibrillar A beta but also oligomers of, in particular, beta 2M from patients with dialysis-associated amyloidosis are capable of inducing CA at supra-physiological concentrations....

  9. Cloning and characterization of human liver cytosolic beta-glycosidase

    NARCIS (Netherlands)

    De Graaf, M; Van Veen, IC; Van Der Meulen-Muileman, IH; Gerritsen, WR; Pinedo, HM; Haisma, HJ

    2001-01-01

    Cytosolic beta -glucosidase (EC 3.2.1.21) from mammalian liver is a member of the family 1 glycoside hydrolases and is known for its ability to hydrolyse a range of beta -D-glycosides. including beta -D-glucoside acid beta -D-galactoside. We therefore refer to this enzyme as cytosolic beta

  10. Beta-glucosidase variants and polynucleotides encoding same

    Science.gov (United States)

    Wogulis, Mark; Harris, Paul; Osborn, David

    2017-06-27

    The present invention relates to beta-glucosidase variants, e.g. beta-glucosidase variants of a parent Family GH3A beta-glucosidase from Aspergillus fumigatus. The present invention also relates to polynucleotides encoding the beta-glucosidase variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the beta-glucosidase variants.

  11. {beta} {gamma} porch detector; Detecteur portique {beta} {gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Roulet, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1963-07-01

    This device is to be placed at the outside of reactors, hot laboratories and others where radioactive products are treated; it is intended to give the alarm when someone, passing through the porch is greatly contaminated, or carries, without his knowing, a radioactive substance. Being to be used in places where there might be an important ground noise, this device is provided with an automatic offset of this noise; an adjusting system of sensitivity allows to obtain a 15 {mu}Ci in {gamma} and 10 {mu}Ci in {beta} radioactive source, passing through the porch at the normal speed at which man is walking. A battery, set in buffer, allows working of the device, even when current is off. (author) [French] Cet appareil est destine a etre place a la sortie des reacteurs, laboratoires chauds ou autres laboratoires travaillant sur des produits radioactifs; son but est de donner une alarme lorsque quelqu'un, passant sous le portique, presente une forte contamination, ou surtout transporte par inadvertance un corps radioactif. Cet appareil devant etre utilise dans les lieux ou peut regner un bruit de fond important, possede une compensation automatique de ce bruit de fond; un reglage de la sensibilite permet d'obtenir au mieux un declenchement pour une source. de 15 {mu}Ci en {gamma} et 10 {mu}Ci en {beta} passant sous le portique a la vitesse normale d'un homme qui marche. Une batterie montee en tampon permet a l'appareil de fonctionner meme en cas de coupure de courant. (auteur)

  12. Preventive Effects of Beta-Hydroxy-Beta-Methyl Butyrate

    Directory of Open Access Journals (Sweden)

    N. Ravanbakhsh

    2016-09-01

    Full Text Available Aims: One of the major factors in sudden cardiac arrest is the initiation and continuation of deadly arrhythmias during ischemia. It is known that beta-hydroxy-beta-methylbutyrate (HMB has useful effects such as anti-inflammatory and anti-apoptosis effects in the skeletal muscles. The aim of this study was to investigate the preventive effects of HMB on the ventricular arrhythmias due to the ischemia. Materials & Methods: In the experimental study, 30 Wistar male rats were randomly divided into three groups including control, HMB320, and HMB700. As control group received normal saline, HMB320 and HMB700 groups orally received 320 and 700 mg/Kg HMB as gavage for 2 weeks, respectively. The rats, having been anesthetized, underwent 30-minute ischemia. Then, the numbers of premature ventricular contractions (PVC, the appearance duration of ventricular tachycardia (VT, and the ventricular fibrillation (VF were assessed. Data was analyzed by SPSS 16 software using Kruskal-Walis, one-way ANOVA, Tukey’s post-hoc, and Chi-square tests. Findings: There was a significant reduction in the mean PVC number in HMB320 and HMB700 groups than control group (p=0.001. In addition, there was such a significant difference between the groups received the doses (p=0.008. There was a reduction in the mean appearance duration of VT in HMB320 and HMB700 groups than control group (p=0.001. There was a significant reduction in the mean appearance duration of VF in HMB700 group compared to control group, only (p=0.003. Conclusion: Through arrhythmias reduction, 2-week preventive consumption of HMB might considerably reduce the severe side effects of ischemia.

  13. Expression of transforming growth factor beta (TGF beta) receptors and expression of TGF beta 1, TGF beta 2 and TGF beta 3 in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Damstrup, L; Rygaard, K; Spang-Thomsen, M

    1993-01-01

    A panel of 21 small cell lung cancer cell (SCLC) lines were examined for the presence of Transforming growth factor beta receptors (TGF beta-r) and the expression of TGF beta mRNAs. By the radioreceptor assay we found high affinity receptors to be expressed in six cell lines. scatchard analysis......(r) = 65,000 and 90,000 and the betaglycan (type III) with M(r) = 280,000. Northern blotting showed expression of TGF beta 1 mRNA in ten, TGF beta 2 mRNA in two and TGF beta 3 mRNA in seven cell lines. Our results provide, for the first time, evidence that a large proportion of a broad panel of SCLC cell...... lines express TGF beta-receptors and also produce TGF beta mRNAs....

  14. Closing of Coster-Kronig transitions in multiply ionised gold atoms

    International Nuclear Information System (INIS)

    Banas, D.; Braziewicz, J.; Czarnota, M.; Fijal, I.; Jaskola, M.; Korman, A.; Kretschmer, W.; Pajek, M.; Semaniak, J.

    2003-01-01

    The paper discusses the effect of closing of L- and M-shell Coster-Kronig (CK) transitions in multiply ionised Au atoms, for which the selected CK transitions become energetically forbidden. This effect plays an important role when the Coster-Kronig energy for single-hole configuration is relatively low, being comparable with a change of the electronic binding energies in multiply ionised atom. We show, by using a simplified model, that for gold the effect of closing of CK transitions occurs for strong L 1 -L 3 M 4,5 transition for the L 1 -subshell as well as the M 3 -M 5 N 6,7 and M 4 -M 5 O 3,4 CK transitions for the M 3 - and M 4 -subshell, respectively. We demonstrate that the discussed effect of closing CK transitions substantially changes the X-ray fluorescence and Coster-Kronig yields and thus has to be considered in interpretation of X-rays excited by heavy ion impact

  15. Beta-agonists and animal welfare

    Science.gov (United States)

    The use of beta-agonists in animal feed is a high profile topic within the U.S. as consumers and activist groups continue to question its safety. The only beta-agonist currently available for use in swine is ractopamine hydrochloride (RAC). This is available as Paylean™ (Elanco Animal Health – FDA a...

  16. Beta-2-mikroglobulin ved medicinske sygdomme

    DEFF Research Database (Denmark)

    Hansen, P B; Olsen, Niels Vidiendal

    1989-01-01

    Beta-2-microglobulin (beta 2M) is a low-molecular protein which is filtered freely over the glomeruli. Under normal circumstances, more than 99.9% is resorbed in the proximal tubuli of the kidneys and is metabolized there. In renal disease with damage to this segment of the nephron, eg acute tubulo...

  17. Topical beta-blockers and mortality

    NARCIS (Netherlands)

    Müskens, Rogier P. H. M.; Wolfs, Roger C. W.; Witteman, Jacqueline C. M.; Hofman, Albert; de Jong, Paulus T. V. M.; Stricker, Bruno H. C.; Jansonius, Nomdo M.

    2008-01-01

    To study the associations between long-term and short-term use of topical beta-blockers and mortality. Prospective population-based cohort study. To examine long-term effects, 3842 participants aged 55 years and older were recruited. To examine short-term effects, 484 incident beta-blocker users and

  18. The beta subunit of casein kinase II

    DEFF Research Database (Denmark)

    Boldyreff, B; Piontek, K; Schmidt-Spaniol, I

    1991-01-01

    cDNAs encoding the beta subunit of pig and mouse CKII were isolated. The porcine cDNA was expressed as a fusion protein in Escherichia coli and used for the production of anti-CKII-beta subunit specific antibodies....

  19. Beta delayed particle emission in light nuclei

    International Nuclear Information System (INIS)

    Riisager, K.; Gabelmann, H.

    1991-01-01

    A short discussion of theoretical treatments of beta delayed particle emission is followed by a presentation of data on the newly found beta delayed deuteron decay of 6 He. This decay cannot be described properly with existing theories. (author) 8 refs.; 3 figs

  20. MINIMUM VARIANCE BETA ESTIMATION WITH DYNAMIC CONSTRAINTS,

    Science.gov (United States)

    developed (at AFETR ) and is being used to isolate the primary error sources in the beta estimation task. This computer program is additionally used to...determine what success in beta estimation can be achieved with foreseeable instrumentation accuracies. Results are included that illustrate the effects on

  1. Synthetic peptides corresponding to human follicle-stimulating hormone (hFSH)-beta-(1-15) and hFSH-beta-(51-65) induce uptake of 45Ca++ by liposomes: evidence for calcium-conducting transmembrane channel formation

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, P.; Santa-Coloma, T.A.; Reichert, L.E. Jr. (Department of Biochemistry, Albany Medical College, New York, NY (USA))

    1991-06-01

    We have previously described FSH receptor-mediated influx of 45Ca++ in cultured Sertoli cells from immature rats and receptor-enriched proteoliposomes via activation of voltage-sensitive and voltage-independent calcium channels. We have further shown that this effect of FSH does not require cholera toxin- or pertussis toxin-sensitive guanine nucleotide binding protein or activation of adenylate cyclase. In the present study, we have identified regions of human FSH-beta-subunit which appear to be involved in mediating calcium influx. We screened 11 overlapping peptide amides representing the entire primary structure of hFSH-beta-subunit for their effects on 45Ca++ flux in FSH receptor-enriched proteoliposomes. hFSH-beta-(1-15) and hFSH-beta-(51-65) induced uptake of 45Ca++ in a concentration-related manner. This effect of hFSH-beta-(1-15) and hFSH-beta-(51-65) was also observed in liposomes lacking incorporated FSH receptor. Reducing membrane fluidity by incubating liposomes (containing no receptor) with hFSH-beta-(1-15) or hFSH-beta-(51-65) at temperatures lower than the transition temperatures of their constituent phospholipids resulted in no significant (P greater than 0.05) difference in 45Ca++ uptake. The effectiveness of the calcium ionophore A23187, however, was abolished. Ruthenium red, a voltage-independent calcium channel antagonist, was able to completely block uptake of 45Ca++ induced by hFSH-beta-(1-15) and hFSH-beta-(51-65) whereas nifedipine, a calcium channel blocker specific for L-type voltage-sensitive calcium channels, was without effect. These results suggest that in addition to its effect on voltage-sensitive calcium channel activity, interaction of FSH with its receptor may induce formation of transmembrane aqueous channels which also facilitate influx of extracellular calcium.

  2. Novel dense CO2 technique for beta-galactosidase immobilization in polystyrene microchannels.

    Science.gov (United States)

    Leclair Ellis, Jeffrey; Tomasko, David L; Dehghani, Fariba

    2008-03-01

    In this study we design new fabrication techniques and demonstrate the potential of using dense CO2 for facilitating crucial steps in the fabrication of polymeric lab-on-a-chip microdevices by embedding biomolecules at temperatures well below the polymer's glass transition temperature (T(g)). These new techniques are environmentally friendly and done without the use of a clean room. Carbon dioxide at 40 degrees C and between 4.48 and 6.89 MPa was used to immobilize the biologically active molecule, beta-galactosidase (beta-gal), on the surface of polystyrene microchannels. To our knowledge, this is the first time dense CO2 has been used to directly immobilize an enzyme in a microchannel. beta-gal activity was maintained and shown via a fluorescent reaction product, after enzyme immobilization and microchannel capping by the designed fabrication steps at 40 degrees C and pressures up to 6.89 MPa.

  3. Selected aspects in the structure of beta-delayed particle spectra

    International Nuclear Information System (INIS)

    Honkanen, J.; Aeystoe, J.; Eskola, K.

    1986-01-01

    Some weak beta-delayed particle emitters in the T z =-3/2, -1, -1/2, +1/2 and +5/2 series are reviewed. Selected features of the delayed particle emission are discussed in terms of experimental delayed particle data and (p,γ), (p,p') and (p,n) reaction data. Experimental beta transition strengths are compared with the existing complete shell-model calculations for the sd-shell nuclei. The effect of the Gamow-Teller giant resonance on the structure of the delayed particle spectra is considered. The correlation between the widths of two decay channels, protons and alpha particles, and the preceeding beta decay is studied in the case of the 40 Sc decay. (orig.)

  4. Purification of beta-acetylglucosaminase and beta-galactosidase from ram testis.

    Science.gov (United States)

    Caygill, J C; Roston, C P; Jevons, F R

    1966-02-01

    1. The presence of beta-galactosidase (EC 3.2.1.23) in an acetic acid extract of ram testis is reported. Some properties of the crude enzyme preparation were studied. 2. The purification of beta-acetylglucosaminase (EC 3.2.1.30) and of beta-galactosidase from the ram-testis extract by ammonium sulphate precipitation and chromatography on a CM-cellulose column is described. 3. The final purifications of the separated enzymes achieved were for the beta-acetylglucosaminase 35 times and for the beta-galactosidase 99 times. 4. The possibility of using DEAE-cellulose and Sephadex G-200 to purify the enzymes was investigated.

  5. Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

    DEFF Research Database (Denmark)

    Martens, Geert A; Jiang, Lei; Hellemans, Karine H

    2011-01-01

    The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture...

  6. Endovascular Irradiations with beta sources

    Energy Technology Data Exchange (ETDEWEB)

    Scmidt, W F.O.; Hawliczek, R [Inst of Radiooncology IRO, Donauspital, Vienna (Austria); Mueck, K [Austrian Research Centre, Siebersdorf ARCS (Austria); Lehmann, D [Inst of Radiotherapy, Univ. Dresden (Germany); Pichler, L [Ludwig Boltzmann Institute for Endovascular Radiotherapy, Donauspital, Vienna (Austria)

    1999-12-31

    For treatment of restenoses tubes (inner/outer diameter 1 and 2 mm; length 3 or 5 mm) with Y-90 foils, shielded by Ti-layers on all sides have been developed (activity 0.5 - 2 GBq). Quality checks with plastic scintillators have been developed and are correlated to absolute dose measurements performed with TLDs (1x1 mm2; 40 mg/cm2). TLD-handling and calibration for beta-dosimetry are described. Additional measurements for depth-dose and dose distribution around the tubes were done with GAFCHROMIC- films and compared to Monte-Carlo calculations with the MCNP4-code, yielding a half-value depth of 0.8 mm from the tube-surface. Manufacturing and delivery of the sources including leakage tests has been standardized, treatments (irradiation times <5min; irradiation length <30mm) are planned to start in spring `98. (authors) 1 refs., 5 figs.

  7. Beta decay of 22O

    International Nuclear Information System (INIS)

    Hubert, F.; Dufour, J.P.; Del Moral, R.; Fleury, A.; Jean, D.; Pravikoff, M.S.; Geissel, H.; Schmidt, K.H.; Hanelt, E.

    1989-01-01

    The study of light nuclei far from stability has been recently renewed by the possibility of production through the projectile fragmentation of intermediate energy heavy ion beams at GANIL. The results presented here have been obtained with the Projectile Fragments Isotopic Separation method developed at the LISE spectrometer. 22 O is a Tz = 3 nucleus and is the first in a series of seven such nuclei in the sd shell extending from 22 O to 24 Mg. Although the half life of 22 O was previously measured by Murphy et al., the present study is the first beta-gamma spectroscopy on this neutron rich nucleus. Five gamma lines have been attributed to the β decay of 22 O with a measured half life of T = (2.25±0.15)s and a partial decay scheme has been established

  8. PBX: the Princeton beta experiment

    International Nuclear Information System (INIS)

    Bol, K.; Chance, M.; Dewar, R.

    1983-09-01

    A rearrangement of the divertor coils in PDX will enable a test in 1984 of the MHD stability properties of deeply indented bean-shaped plasmas. The goal is a beta of 10%. Indentation is expected to counter the deterioration of MHD stability against pressure driven modes that is occasioned by the larger aspect ratios typical of anticipated reactor oriented devices. Indeed, as shown by M. Chance et al., indentation may offer direct access to the second region of stability for ballooning modes, and numerical analyses with PEST show the internal kink to be stabilized completely with even relatively modest indentation. The internal kink is implicated in the loss of beam ions in PDX. In this report the theoretical basis for the forthcoming experiment, and the design considerations underlying the modification from PDX to PBX, are described in detail. Additional theoretical material, including an analysis of particle orbits in an indented tokamak plasma, is appended

  9. Formation of a stable oligomer of beta-2 microglobulin requires only transient encounter with Cu(II).

    Science.gov (United States)

    Calabrese, Matthew F; Miranker, Andrew D

    2007-03-16

    Beta-2 Microglobulin (beta2m) is a small, globular protein, with high solubility under conditions comparable to human serum. A complication of hemodialysis in renal failure patients is the deposition of unmodified beta2m as amyloid fibers. In vitro, exposure of beta2m to equimolar Cu(2+) under near-physiological conditions can result in self-association leading to amyloid fiber formation. Previously, we have shown that the early steps in this process involve a catalyzed structural rearrangement followed by formation of discrete oligomers. These oligomers, however, have a continued requirement for Cu(2+) while mature fibers are resistant to addition of metal chelate. Here, we report that the transition from Cu(2+) dependent to chelate resistant states occurs in the context of small oligomers, dimeric to hexameric in size. These species require Cu(2+) to form, but once generated, do not need metal cation for stability. Importantly, this transition occurs gradually over several days and the resulting oligomers are isolatable and kinetically stable on timescales exceeding weeks. In addition, formation is enhanced by levels of urea similar to those found in hemodialysis patients. Our results are consistent with our hypothesis that transient encounter of full-length wild-type beta2m with transition metal cation at the dialysis membrane interface is causal to dialysis related amyloidosis.

  10. Localization of thymosin beta-4 in tumors

    DEFF Research Database (Denmark)

    Larsson, L. -I.; Holck, Susanne

    2007-01-01

    in colorectal carcinomas. The degree of staining of breast cancer cells for thymosin beta-4 correlated neither to histological grade nor to endothelial cell staining. However, there was a tendency toward correlation (P = 0.07) between staining of endothelial cells and histological grade. Treatment of cultured......Overexpression of thymosin beta-4 has been linked to malignant progression but the localization of this polypeptide within tumors is incompletely known. We therefore examined breast cancers for thymosin beta-4 using immunofluorescence. Reactive cells were identified with monoclonal cell marker...... breast cancer cells (SK-BR-3) with 1-4 microg thymosin beta-4/mL significantly increased cell numbers, as determined by MTT-assays. These data reveal an unexpected cellular heterogeneity of thymosin beta-4 expression in breast and colonic carcinomas and suggest that local release of this polypeptide...

  11. Ranking beta sheet topologies of proteins

    DEFF Research Database (Denmark)

    Fonseca, Rasmus; Helles, Glennie; Winter, Pawel

    2010-01-01

    One of the challenges of protein structure prediction is to identify long-range interactions between amino acids. To reliably predict such interactions, we enumerate, score and rank all beta-topologies (partitions of beta-strands into sheets, orderings of strands within sheets and orientations...... of paired strands) of a given protein. We show that the beta-topology corresponding to the native structure is, with high probability, among the top-ranked. Since full enumeration is very time-consuming, we also suggest a method to deal with proteins with many beta-strands. The results reported...... in this paper are highly relevant for ab initio protein structure prediction methods based on decoy generation. The top-ranked beta-topologies can be used to find initial conformations from which conformational searches can be started. They can also be used to filter decoys by removing those with poorly...

  12. Maternal plasma concentrations of beta-lipotrophin, beta-endorphin and gamma-lipotrophin throughout pregnancy.

    Science.gov (United States)

    Browning, A J; Butt, W R; Lynch, S S; Shakespear, R A

    1983-12-01

    Plasma beta-LPH, beta-EP and gamma-LPH concentrations were measured by radioimmunoassay in 10 pregnant women from 12 weeks gestation until term and in nine women in the early follicular phase of the cycle. There was a progressive and significant rise in the concentration of all three peptides throughout pregnancy and by 32 weeks the concentrations of beta-LPH and beta-EP were greater than the corresponding concentrations in the follicular phase: gamma-LPH was greater than in the follicular phase by the end of pregnancy in those women who were delivered after 40 weeks. The ratio of beta-LPH to gamma-LPH did not change significantly throughout pregnancy, but there was a progressive fall in the beta-LPH/beta-EP ratio. The possible presence of a 'big LPH' to explain this finding is discussed.

  13. Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

    DEFF Research Database (Denmark)

    Martens, Geert A; Jiang, Lei; Hellemans, Karine H

    2011-01-01

    The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture...... microdissected beta cells, monitor adaptations of the beta cell phenotype to fasting, and retrieve possible conserved transcriptional regulators....

  14. Dimers of beta 2-glycoprotein I mimic the in vitro effects of beta 2-glycoprotein I-anti-beta 2-glycoprotein I antibody complexes

    NARCIS (Netherlands)

    Lutters, B. C.; Meijers, J. C.; Derksen, R. H.; Arnout, J.; de Groot, P. G.

    2001-01-01

    Anti-beta(2)-glycoprotein I antibodies are thought to cause lupus anticoagulant activity by forming bivalent complexes with beta(2)-glycoprotein I (beta(2)GPI). To test this hypothesis, chimeric fusion proteins were constructed of the dimerization domain (apple 4) of factor XI and beta(2)GPI. Both a

  15. Hydrogen bonds between the alpha and beta subunits of the F1-ATPase allow communication between the catalytic site and the interface of the beta catch loop and the gamma subunit.

    Science.gov (United States)

    Boltz, Kathryn W; Frasch, Wayne D

    2006-09-19

    F(1)-ATPase mutations in Escherichia coli that changed the strength of hydrogen bonds between the alpha and beta subunits in a location that links the catalytic site to the interface between the beta catch loop and the gamma subunit were examined. Loss of the ability to form the hydrogen bonds involving alphaS337, betaD301, and alphaD335 lowered the k(cat) of ATPase and decreased its susceptibility to Mg(2+)-ADP-AlF(n) inhibition, while mutations that maintain or strengthen these bonds increased the susceptibility to Mg(2+)-ADP-AlF(n) inhibition and lowered the k(cat) of ATPase. These data suggest that hydrogen bonds connecting alphaS337 to betaD301 and betaR323 and connecting alphaD335 to alphaS337 are important to transition state stabilization and catalytic function that may result from the proper alignment of catalytic site residues betaR182 and alphaR376 through the VISIT sequence (alpha344-348). Mutations betaD301E, betaR323K, and alphaR282Q changed the rate-limiting step of the reaction as determined by an isokinetic plot. Hydrophobic mutations of betaR323 decreased the susceptibility to Mg(2+)-ADP-AlF(n)() inhibition and lowered the number of interactions required in the rate-limiting step yet did not affect the k(cat) of ATPase, suggesting that betaR323 is important to transition state formation. The decreased rate of ATP synthase-dependent growth and decreased level of lactate-dependent quenching observed with alphaD335, betaD301, and alphaE283 mutations suggest that these residues may be important to the formation of an alternative set of hydrogen bonds at the interface of the alpha and beta subunits that permits the release of intersubunit bonds upon the binding of ATP, allowing gamma rotation in the escapement mechanism.

  16. Period concatenation underlies interactions between gamma and beta rhythms in neocortex

    Directory of Open Access Journals (Sweden)

    Anita K Roopun

    2008-04-01

    Full Text Available The neocortex generates rhythmic electrical activity over a frequency range covering many decades. Specific cognitive and motor states are associated with oscillations in discrete frequency bands within this range, but it is not known whether interactions and transitions between distinct frequencies are of functional importance. When coexpressed rhythms have frequencies that differ by a factor of two or more interactions can be seen in terms of phase synchronization. Larger frequency differences can result in interactions in the form of nesting of faster frequencies within slower ones by a process of amplitude modulation. It is not known how coexpressed rhythms, whose frequencies differ by less than a factor of two may interact. Here we show that two frequencies (gamma – 40 Hz and beta2 – 25 Hz, coexpressed in superficial and deep cortical laminae with low temporal interaction, can combine to generate a third frequency (beta1 – 15 Hz showing strong temporal interaction. The process occurs via period concatenation, with basic rhythm-generating microcircuits underlying gamma and beta2 rhythms forming the building blocks of the beta1 rhythm by a process of addition. The mean ratio of adjacent frequency components was a constant – approximately the golden mean – which served to both minimize temporal interactions, and permit multiple transitions, between frequencies. The resulting temporal landscape may provide a framework for multiplexing – parallel information processing on multiple temporal scales.

  17. Beta decay of 46Cr

    International Nuclear Information System (INIS)

    Onishi, T K; Gelberg, A; Sakurai, H; Yoneda, K; Aoi, N; Imai, N; Baba, H; Brentano, P von; Fukuda, N; Ichikawa, Y; Ishihara, M; Iwasaki, H; Kameda, D; Kishida, T; Lisetskiy, A F; Ong, H J; Osada, M; Otsuka, T; Suzuki, M K; Ue, K; Utsuno, Y; Watanabe, H

    2006-01-01

    The Gamow-Teller transition of 46 Cr to the N = Z odd-odd nucleus 46 V has been observed for the first time. By means of β-γ coincidence measurements, a γ-ray peak at 993 keV corresponding to the decay of the 1 + 1 state in 46 V was observed. The branching ratio of the decay to this state was found to be b GT = 0.25 ± 0.050. The half-life of 46 Cr was measured to be T 1/2 = 240 ± 140 ms. The transition strength was determined to be B(GT) = 0.64 ± 0.20. This result was compared with theoretical calculations

  18. Sequence swapping does not result in conformation swapping for the beta4/beta5 and beta8/beta9 beta-hairpin turns in human acidic fibroblast growth factor.

    Science.gov (United States)

    Kim, Jaewon; Lee, Jihun; Brych, Stephen R; Logan, Timothy M; Blaber, Michael

    2005-02-01

    The beta-turn is the most common type of nonrepetitive structure in globular proteins, comprising ~25% of all residues; however, a detailed understanding of effects of specific residues upon beta-turn stability and conformation is lacking. Human acidic fibroblast growth factor (FGF-1) is a member of the beta-trefoil superfold and contains a total of five beta-hairpin structures (antiparallel beta-sheets connected by a reverse turn). beta-Turns related by the characteristic threefold structural symmetry of this superfold exhibit different primary structures, and in some cases, different secondary structures. As such, they represent a useful system with which to study the role that turn sequences play in determining structure, stability, and folding of the protein. Two turns related by the threefold structural symmetry, the beta4/beta5 and beta8/beta9 turns, were subjected to both sequence-swapping and poly-glycine substitution mutations, and the effects upon stability, folding, and structure were investigated. In the wild-type protein these turns are of identical length, but exhibit different conformations. These conformations were observed to be retained during sequence-swapping and glycine substitution mutagenesis. The results indicate that the beta-turn structure at these positions is not determined by the turn sequence. Structural analysis suggests that residues flanking the turn are a primary structural determinant of the conformation within the turn.

  19. The effects of beta-endorphin: state change modification.

    Science.gov (United States)

    Veening, Jan G; Barendregt, Henk P

    2015-01-29

    Beta-endorphin (β-END) is an opioid neuropeptide which has an important role in the development of hypotheses concerning the non-synaptic or paracrine communication of brain messages. This kind of communication between neurons has been designated volume transmission (VT) to differentiate it clearly from synaptic communication. VT occurs over short as well as long distances via the extracellular space in the brain, as well as via the cerebrospinal fluid (CSF) flowing through the ventricular spaces inside the brain and the arachnoid space surrounding the central nervous system (CNS). To understand how β-END can have specific behavioral effects, we use the notion behavioral state, inspired by the concept of machine state, coming from Turing (Proc London Math Soc, Series 2,42:230-265, 1937). In section 1.4 the sequential organization of male rat behavior is explained showing that an animal is not free to switch into another state at any given moment. Funneling-constraints restrict the number of possible behavioral transitions in specific phases while at other moments in the sequence the transition to other behavioral states is almost completely open. The effects of β-END on behaviors like food intake and sexual behavior, and the mechanisms involved in reward, meditation and pain control are discussed in detail. The effects on the sequential organization of behavior and on state transitions dominate the description of these effects.

  20. Assessment of affinities of beta-CIT, beta-CIT-FE, and beta-CIT-FP for monoamine transporters permanently expressed in cell lines

    International Nuclear Information System (INIS)

    Okada, Tomoya; Fujita, Masahiro; Shimada, Shoichi; Sato, Kohji; Schloss, Patrick; Watanabe, Yoshiyuki; Itoh, Yasushi; Tohyama, Masaya; Nishimura, Tsunehiko

    1998-01-01

    We investigated the effects of three cocaine analogs, beta-CIT (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-tropane), beta-CIT-FE (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-N-(2-fluoroethyl)-nortropane), and beta-CIT-FP (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane), on the uptake of [ 3 H]dopamine(DA), serotonin(5-HT), and 1-norepinephrine (NE) using cell lines permanently expressing DA, 5-HT, and NE transporters, respectively, to determine their affinities for these three transporters. We generated cell lines stably expressing DA, 5-HT, and NE transporters, respectively, by the Chen-Okayama method, and then tested the abilities of (-)cocaine, beta-CIT, beta-CIT-FE, beta-CIT-FP, and clomipramine to inhibit the uptake of [ 3 H]DA, 5-HT, and 1-NE. Ki values of beta-CIT, beta-CIT-FE, and beta-CIT-FP for [ 3 H]DA, 5-HT, 1-NE uptake were 6, 29, and 33 nM, 91, 133, and 130 nM, and 28, 113 and 70 nM, respectively, whereas those of cocaine and clomipramine were 316, 581, and 176 nM and > 10,000, 437, and 851 nM, respectively. Beta-CIT, beta-CIT-FE, and beta-CIT-FP were shown to be potent DA, 5-HT, and NE uptake inhibitors. Beta-CIT and beta-CIT-FP were highly potent and selective dopamine uptake inhibitors, and therefore might be useful for imaging of DA transporter with single photon emission computed tomography (SPECT) or positron emission tomography (PET)

  1. Ellagic acid promotes A{beta}42 fibrillization and inhibits A{beta}42-induced neurotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Ying [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Yang, Shi-gao; Du, Xue-ting; Zhang, Xi; Sun, Xiao-xia; Zhao, Min [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Sun, Gui-yuan, E-mail: sungy2004@sohu.com [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Liu, Rui-tian, E-mail: rtliu@tsinghua.edu.cn [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China)

    2009-12-25

    Smaller, soluble oligomers of {beta}-amyloid (A{beta}) play a critical role in the pathogenesis of Alzheimer's disease (AD). Selective inhibition of A{beta} oligomer formation provides an optimum target for AD therapy. Some polyphenols have potent anti-amyloidogenic activities and protect against A{beta} neurotoxicity. Here, we tested the effects of ellagic acid (EA), a polyphenolic compound, on A{beta}42 aggregation and neurotoxicity in vitro. EA promoted A{beta} fibril formation and significant oligomer loss, contrary to previous results that polyphenols inhibited A{beta} aggregation. The results of transmission electron microscopy (TEM) and Western blot displayed more fibrils in A{beta}42 samples co-incubated with EA in earlier phases of aggregation. Consistent with the hypothesis that plaque formation may represent a protective mechanism in which the body sequesters toxic A{beta} aggregates to render them harmless, our MTT results showed that EA could significantly reduce A{beta}42-induced neurotoxicity toward SH-SY5Y cells. Taken together, our results suggest that EA, an active ingredient in many fruits and nuts, may have therapeutic potential in AD.

  2. The electronic and optical properties of germanium tellurite glasses containing various transition metal oxides

    International Nuclear Information System (INIS)

    Khan, M.N.

    1988-01-01

    Various transition metal oxides, such as TiO 2 , V 2 O 5 , NiO, CuO, and ZnO are added to germanium-tellurite glass and measurements are reported of the electrical conductivity, density, optical absorption, infra-red absorption spectra, and electron spin resonance. It is found that the d.c. conductivity of glasses containing the same amount of V 2 O 5 is higher than that of germanium tellurite glasses containing a similar amount of other transition metal oxides, and is due to hopping between localized states. The optical absorption measurements show that the fundamental absorption edge is a function of glass composition and the optical absorption is due to forbidden indirect transitions. From the infra-red absorption spectra, it is found that the addition of transition metal oxides does not introduce any new absorption band in the infra-red spectrum of germanium tellurite glasses. A small shift of existing absorptions toward higher wave number is observed. The ESR measurements revealed that some transition metal ions are diamagnetic while others are paramagnetic in the glass network. (author)

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

    OpenAIRE

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

    1996-01-01

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

  4. Review of modern double beta decay experiments

    Science.gov (United States)

    Barabash, A. S.

    2015-10-01

    The review of modern experiments on search and studying of double beta decay processes is done. Results of the most sensitive current experiments are discussed. The main attention is paid to EXO-200, KamLAND-Zen, GERDA-I and CUORE-0 experiments. Modern values of T1/2(2ν) and best present limits on neutrinoless double beta decay and double beta decay with Majoron emission are presented. Conservative limits on effective mass of a Majorana neutrino ( at the level of ˜ 0.01-0.1 eV are discussed.

  5. Silent ischemia and beta-blockade

    DEFF Research Database (Denmark)

    Egstrup, K

    1991-01-01

    and should also be directed at the other coronary artery risk factors of the patients. The effects of beta-blockers, which reduce the duration and frequency of silent ischemic episodes, is well described. The effect is most pronounced in the morning, when the frequency of ischemia is highest......, and the mechanism of action seems mainly mediated through a reduction in myocardial oxygen demand. beta-Blockers have shown effectiveness in both effort-induced angina and mixed angina, and increased anti-ischemic potency may be achieved by combination therapy with a calcium antagonist. Abrupt withdrawal of beta-blockers...

  6. Venus gravity - Analysis of Beta Regio

    Science.gov (United States)

    Esposito, P. B.; Sjogren, W. L.; Mottinger, N. A.; Bills, B. G.; Abbott, E.

    1982-01-01

    Radio tracking data acquired over Beta Regio were analyzed to obtain a surface mass distribution from which a detailed vertical gravity field was derived. In addition, a corresponding vertical gravity field was evaluated solely from the topography of the Beta region. A comparison of these two maps confirms the strong correlation between gravity and topography which was previously seen in line-of-sight gravity maps. It also demonstrates that the observed gravity is a significant fraction of that predicted from the topography alone. The effective depth of complete isostatic compensation for the Beta region is estimated to be 330 km, which is somewhat deeper than that found for other areas of Venus.

  7. Application of Monte Carlo method in study of the padronization for radionuclides with complex disintegration scheme in 4{pi}{beta}-{gamma} coincidence System; Aplicacao do metodo de Monte Carlo no estudo da padronizacao de radionuclideos com esquema de desintegracao complexos em sistema de coincidencias 4{pi}{beta}-{gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Mauro Noriaki

    2006-07-01

    The present work described a new methodology for modelling the behaviour of the activity in a 4{pi}{beta}-{gamma} coincidence system. The detection efficiency for electrons in the proportional counter and gamma radiation in the NaI(Tl) detector was calculated using the Monte Carlo program MCNP4C. Another Monte Carlo code was developed which follows the path in the disintegration scheme from the initial state of the precursor radionuclide, until the ground state of the daughter nucleus. Every step of the disintegration scheme is sorted by random numbers taking into account the probabilities of all {beta}{sup -} branches, electronic capture branches, transitions probabilities and internal conversion coefficients. Once the final state was reached beta, electronic capture events and gamma transitions are accounted for the three spectra: beta, gamma and coincidence variation in the beta efficiency was performed simulating energy cut off or use of absorbers (Collodion). The selected radionuclides for simulation were: {sup 134}Cs, {sup 72}Ga which disintegrate by {beta}{sup -} transition, {sup 133}Ba which disintegrates by electronic capture and {sup 35}S which is a beta pure emitter. For the latter, the Efficiency Tracing technique was simulated. The extrapolation curves obtained by Monte Carlo were filled by the Least Square Method with the experimental points and the results were compared to the Linear Extrapolation method. (author)

  8. Dopamine beta-hydroxylase deficiency

    Directory of Open Access Journals (Sweden)

    Senard Jean-Michel

    2006-03-01

    Full Text Available Abstract Dopamine beta-hydroxylase (DβH deficiency is a very rare form of primary autonomic failure characterized by a complete absence of noradrenaline and adrenaline in plasma together with increased dopamine plasma levels. The prevalence of DβH deficiency is unknown. Only a limited number of cases with this disease have been reported. DβH deficiency is mainly characterized by cardiovascular disorders and severe orthostatic hypotension. First symptoms often start during a complicated perinatal period with hypotension, muscle hypotonia, hypothermia and hypoglycemia. Children with DβH deficiency exhibit reduced ability to exercise because of blood pressure inadaptation with exertion and syncope. Symptoms usually worsen progressively during late adolescence and early adulthood with severe orthostatic hypotension, eyelid ptosis, nasal stuffiness and sexual disorders. Limitation in standing tolerance, limited ability to exercise and traumatic morbidity related to falls and syncope may represent later evolution. The syndrome is caused by heterogeneous molecular alterations of the DBH gene and is inherited in an autosomal recessive manner. Restoration of plasma noradrenaline to the normal range can be achieved by therapy with the synthetic precursor of noradrenaline, L-threo-dihydroxyphenylserine (DOPS. Oral administration of 100 to 500 mg DOPS, twice or three times daily, increases blood pressure and reverses the orthostatic intolerance.

  9. The SNO+ experiment for neutrinoless double-beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Lozza, Valentina; Krosigk, Belina von; Soerensen, Arnd; Zuber, Kai [Institut fuer Kern- und Teilchenphysik, Dresden (Germany)

    2015-07-01

    SNO+ is a large liquid scintillator based experiment that re-uses the Sudbury Neutrino Observatory detector. The detector, located 2 km underground in a mine near Sudbury, Canada, consists of a 12 m diameter acrylic vessel which will be filled with 780 tonnes of liquid scintillator. The main physics goal of SNO+ is to search for the neutrinoless double-beta (0n2b) decay of {sup 130}Te. During the double-beta phase, the liquid scintillator will be initially loaded with 0.3% natural tellurium (nearly 800 kg of {sup 130}Te). During this demonstration phase we anticipate that we will achieve a sensitivity in the region just above the inverted neutrino mass hierarchy. Recently the possibility to deploy up to 10 times more natural tellurium is being developed, by which SNO+ could explore, in the near future, deep into the parameter space for the inverted hierarchy. Designed as a general purpose neutrino experiment, SNO+ can additionally measure the reactor neutrino oscillations, geo-neutrinos in a geologically-interesting location, watch supernova neutrinos and measure low energy solar neutrinos. A first commissioning phase with the detector filled with water has started in autumn 2014, while full running with water will take place in 2015. Transition to the scintillator phase will start towards the end of 2015. The 0n2b decay phase is foreseen for the 2016.

  10. Shear localization and microstructure in coarse grained beta titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bingfeng, E-mail: biw009@ucsd.edu [State Key Laboratory for Powder Metallurgy, Central South University, Changsha, Hunan (China); School of Materials Science and Engineering, Central South University, Changsha, Hunan (China); Department of Mechanical and Aerospace Engineering, University of California, San Diego, United States of America (United States); Key Lab of Nonferrous Materials, Ministry of Education, Central South University, Changsha, Hunan (China); Wang, Xiaoyan [State Key Laboratory for Powder Metallurgy, Central South University, Changsha, Hunan (China); School of Materials Science and Engineering, Central South University, Changsha, Hunan (China); Li, Zezhou [Department of Mechanical and Aerospace Engineering, University of California, San Diego, United States of America (United States); Ma, Rui [School of Materials Science and Engineering, Central South University, Changsha, Hunan (China); Zhao, Shiteng [Department of Mechanical and Aerospace Engineering, University of California, San Diego, United States of America (United States); Xie, Fangyu [State Key Laboratory for Powder Metallurgy, Central South University, Changsha, Hunan (China); School of Materials Science and Engineering, Central South University, Changsha, Hunan (China); Zhang, Xiaoyong [State Key Laboratory for Powder Metallurgy, Central South University, Changsha, Hunan (China)

    2016-01-15

    Adiabatic shear localization plays an important role in the deformation and failure of the coarse grained beta titanium alloy Ti-5 Al-5 Mo-5 V-1 Cr-1 Fe with grain size about 1 mm at high strain rate deformation. Hat shaped specimens with different nominal shear strains are used to induce the formation of shear bands under the controlled shock-loading experiments. The true stress in the specimens can reach about 1040 MPa where the strain is about 1.83. The whole shear localization process lasts about 35 μs. The microstructures within the shear band are investigated by optical microscopy, scanning electron microscopy / electron backscatter diffraction, and transmission electron microscopy. The results show that the width of the shear bands decreases with increasing nominal shear strain, and the grains in the transition region near the shear band are elongated along the shear band, and the core of the shear band consists of the ultrafine deformed grains with width of 0.1 μm and heavy dislocations. With the aims of accommodating the imposed shear strain and maintaining neighboring grain compatibility, the grain subdivision continues to take place within the band. A fiber texture is formed in the core of the shear band. The calculated temperature rise in the shear band can reach about 722 K. Dynamic recovery is responsible for the formation of the microstructure in coarse grained beta titanium alloy.

  11. An experimental investigation of double beta decay of 100Mo

    International Nuclear Information System (INIS)

    Dougherty, B.L.

    1988-01-01

    New limits on half-lives for several double beta decay modes of 100 Mo were obtained with a novel experimental system which included thin source films interleaved with a coaxial array of windowless silicon detectors. Segmentation and timing information allowed backgrounds originating in the films to be studied in some detail. Dummy films containing 96 Mo were used to assess remaining backgrounds. With 0.1 mole years of 100 Mo data collected, the lower half-life limits at 90% confidence were 2.7 /times/ 10 18 years for decay via the two-neutrino mode, 5.2 /times/10 19 years for decay with the emission of a Majoron, and 1.6 /times/ 10 20 years and 2.2 /times/ 10 21 years for neutrinoless 0 + → 2 + and 0 + → 0 + transitions, respectively. 50 refs., 38 figs., 11 tabs

  12. Beta decay of 31,32Na and 31Mg

    International Nuclear Information System (INIS)

    Klotz, G.; Baumann, P.; Bounajma, M.; Huck, A.; Knipper, A.; Walter, G.; Poves, A.; Retamosa, J.

    1993-01-01

    31,32 Na and 31 Mg beta decays were studied at the CERN on-line mass separator ISOLDE by gamma, gamma-gamma and neutron-gamma measurements. In the 31 Na decay, the assignment of previously reported γ transitions and the observation of a new level at 3760 keV lead to a revised decay scheme. In the 31 Mg → 31 Al decay, a new decay scheme involves ten β branches and three states are reported for the first time. New spectroscopic results have been obtained in the 32 Na β - decay. A previously non-interpreted 1436 keV γ ray is now assigned in the 32 Mg scheme. (author) 33 refs., 16 figs., 12 tabs

  13. Systematic Risk on Istanbul Stock Exchange: Traditional Beta Coefficient Versus Downside Beta Coefficient

    Directory of Open Access Journals (Sweden)

    Gülfen TUNA

    2013-03-01

    Full Text Available The aim of this study is to test the validity of Downside Capital Asset Pricing Model (D-CAPM on the ISE. At the same time, the explanatory power of CAPM's traditional beta and D-CAPM's downside beta on the changes in the average return values are examined comparatively. In this context, the monthly data for seventy three stocks that are continuously traded on the ISE for the period 1991-2009 is used. Regression analysis is applied in this study. The research results have shown that D-CAPM is valid on the ISE. In addition, it is obtained that the power of downside beta coefficient is higher than traditional beta coefficient on explaining the return changes. Therefore, it can be said that the downside beta is superior to traditional beta in the ISE for chosen period.

  14. How Do Beta Blocker Drugs Affect Exercise?

    Science.gov (United States)

    ... in lieu of exercise. Exercise has many other benefits and is important to maintain your health. Read how physical activity improves the quality of life . Concerns About Exercising While on Beta Blockers “It’s important to remember ...

  15. Review of modern double beta decay experiments

    Energy Technology Data Exchange (ETDEWEB)

    Barabash, A. S., E-mail: barabash@itep.ru [Institute of Theoretical and Experimental Physics (NRC ”Kurchatov Institute”), B. Cheremushkinskaya 25, Moscow (Russian Federation)

    2015-10-28

    The review of modern experiments on search and studying of double beta decay processes is done. Results of the most sensitive current experiments are discussed. The main attention is paid to EXO-200, KamLAND-Zen, GERDA-I and CUORE-0 experiments. Modern values of T{sub 1/2}(2ν) and best present limits on neutrinoless double beta decay and double beta decay with Majoron emission are presented. Conservative limits on effective mass of a Majorana neutrino (〈m{sub ν}〉 < 0.46 eV) and a coupling constant of Majoron to neutrino (〈g{sub ee}〉 < 1.3 · 10{sup −5}) are obtained. Prospects of search for neutrinoless double beta decay in new experiments with sensitivity to 〈m{sub ν}〉 at the level of ∼ 0.01-0.1 eV are discussed.

  16. Split Beta-Lactamase Complementation Assay

    Indian Academy of Sciences (India)

    IAS Admin

    A Search for the Molecular Better Half! Vaishali Verma ... These assays comprise of a protein molecule, ... ciferase, beta-galactosidase, GFP, g3p of M13 filamentous ph- .... sensors of protein–protein interactions, Nature Biotechnology, Vol.20,.

  17. Beta cell proliferation and growth factors

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis; Svensson, C; Møldrup, Annette

    1999-01-01

    Formation of new beta cells can take place by two pathways: replication of already differentiated beta cells or neogenesis from putative islet stem cells. Under physiological conditions both processes are most pronounced during the fetal and neonatal development of the pancreas. In adulthood little...... increase in the beta cell number seems to occur. In pregnancy, however, a marked hyperplasia of the beta cells is observed both in rodents and man. Increased mitotic activity has been seen both in vivo and in vitro in islets exposed to placental lactogen (PL), prolactin (PRL) and growth hormone (GH...... and activation of the tyrosine kinase JAK2 and the transcription factors STAT1 and 3. The activation of the insulin gene however also requires the distal part of the receptor and activation of calcium uptake and STAT5. In order to identify putative autocrine growth factors or targets for growth factors we have...

  18. Beta-binomial regression and bimodal utilization.

    Science.gov (United States)

    Liu, Chuan-Fen; Burgess, James F; Manning, Willard G; Maciejewski, Matthew L

    2013-10-01

    To illustrate how the analysis of bimodal U-shaped distributed utilization can be modeled with beta-binomial regression, which is rarely used in health services research. Veterans Affairs (VA) administrative data and Medicare claims in 2001-2004 for 11,123 Medicare-eligible VA primary care users in 2000. We compared means and distributions of VA reliance (the proportion of all VA/Medicare primary care visits occurring in VA) predicted from beta-binomial, binomial, and ordinary least-squares (OLS) models. Beta-binomial model fits the bimodal distribution of VA reliance better than binomial and OLS models due to the nondependence on normality and the greater flexibility in shape parameters. Increased awareness of beta-binomial regression may help analysts apply appropriate methods to outcomes with bimodal or U-shaped distributions. © Health Research and Educational Trust.

  19. Encoded Extended Spectrum Beta-Lactamases Produced

    African Journals Online (AJOL)

    26.1 % Klebsiella spp were positive for extended spectrum beta-lactamases ... issue, and TEM, OXA and SHV type ESBL were the most common genotypes. ... mechanism of action. ..... and Multiplex PCR Screening of AmpC Genes from.

  20. Genetics Home Reference: beta-mannosidosis

    Science.gov (United States)

    ... enzyme beta-mannosidase. This enzyme works in the lysosomes , which are compartments that digest and recycle materials in the cell. Within lysosomes, the enzyme helps break down complexes of sugar ...

  1. Literature in Focus Beta Beams: Neutrino Beams

    CERN Document Server

    2009-01-01

    By Mats Lindroos (CERN) and Mauro Mezzetto (INFN Padova, Italy) Imperial Press, 2009 The beta-beam concept for the generation of electron neutrino beams was first proposed by Piero Zucchelli in 2002. The idea created quite a stir, challenging the idea that intense neutrino beams only could be produced from the decay of pions or muons in classical neutrino beams facilities or in future neutrino factories. The concept initially struggled to make an impact but the hard work by many machine physicists, phenomenologists and theoreticians over the last five years has won the beta-beam a well-earned position as one of the frontrunners for a possible future world laboratory for high intensity neutrino oscillation physics. This is the first complete monograph on the beta-beam concept. The book describes both technical aspects and experimental aspects of the beta-beam, providing students and scientists with an insight into the possibilities o...

  2. Oxygen pressure manipulations on the metal-insulator transition characteristics of highly (011)-oriented vanadium dioxide films grown by magnetron sputtering

    International Nuclear Information System (INIS)

    Yu Qian; Li Wenwu; Duan Zhihua; Hu Zhigao; Chu Junhao; Liang Jiran; Chen Hongda; Liu Jian

    2013-01-01

    The metal-insulator transition behaviour of vanadium dioxide (VO 2 ) films grown at different oxygen pressures is investigated. With the aid of temperature-dependent electrical and infrared transmittance experiments, it is found that the transition temperature in the heating process goes up with increasing argon-oxygen ratio, whereas the one in the cooling process shows an inverse variation trend. It is found that the hysteresis width of the phase transition is narrowed at a lower argon-oxygen ratio because the defects introduced by excess oxygen lower the energy requirement of transformation. Furthermore, the defects reduce the forbidden gap of the VO 2 system due to the generation of a V 5+ ion. The present results are valuable for the achievement of VO 2 -based optoelectronic devices.

  3. Near-infrared line identification in type Ia supernovae during the transitional phase

    Energy Technology Data Exchange (ETDEWEB)

    Friesen, Brian; Baron, E.; Wisniewski, John P.; Miller, Timothy R. [Homer L. Dodge Department of Physics and Astronomy, 440 West Brooks Street, Room 100, Norman, OK 73019 (United States); Parrent, Jerod T. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Thomas, R. C. [Computational Cosmology Center, Computational Research Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 50B-4206, Berkeley, CA 94720 (United States); Marion, G. H. [University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States)

    2014-09-10

    We present near-infrared synthetic spectra of a delayed-detonation hydrodynamical model and compare them to observed spectra of four normal Type Ia supernovae ranging from day +56.5 to day +85. This is the epoch during which supernovae are believed to be undergoing the transition from the photospheric phase, where spectra are characterized by line scattering above an optically thick photosphere, to the nebular phase, where spectra consist of optically thin emission from forbidden lines. We find that most spectral features in the near-infrared can be accounted for by permitted lines of Fe II and Co II. In addition, we find that [Ni II] fits the emission feature near 1.98 μm, suggesting that a substantial mass of {sup 58}Ni exists near the center of the ejecta in these objects, arising from nuclear burning at high density.

  4. Surface hopping, transition state theory, and decoherence. II. Thermal rate constants and detailed balance

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Amber; Subotnik, Joseph E., E-mail: subotnik@sas.upenn.edu [Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104 (United States)

    2015-10-07

    We investigate a simple approach to compute a non-adiabatic thermal rate constant using the fewest switches surface hopping (FSSH) dynamics. We study the effects of both decoherence (using our augmented-FSSH (A-FSSH) algorithm) and forbidden hops over a large range of parameters, including high and low friction regimes, and weak and strong electronic coupling regimes. Furthermore, when possible, we benchmark our results against exact hierarchy equations of motion results, where we usually find a maximum error of roughly a factor of two (at reasonably large temperatures). In agreement with Hammes-Schiffer and Tully, we find that a merger of transition state theory and surface hopping can be both accurate and efficient when performed correctly. We further show that detailed balance is followed approximately by A-FSSH dynamics.

  5. Micro-battery Development using beta radioisotope

    International Nuclear Information System (INIS)

    Jung, H. K.; Cheong, Y. M.; Lee, N. H.; Choi, Y. S.; Joo, Y. S.; Lee, J. S.; Jeon, B. H.

    2007-06-01

    Nuclear battery which use the beta radiation sources emitting the low penetration radiation energy from radioisotope can be applied as the long term (more than 10 years) micro power source in MEMS and nano components. This report describes the basic concept and principles of nuclear micro-battery and its fabrication in space and military field. In particular direct conversion method is described by investigating the electron-hole generation and recombination in p-n junction of silicon betavoltaics with beta radiation

  6. Beta/alpha continuous air monitor

    Science.gov (United States)

    Becker, G.K.; Martz, D.E.

    1988-06-27

    A single deep layer silicon detector in combination with a microcomputer, recording both alpha and beta activity and the energy of each pulse, distinquishing energy peaks using a novel curve fitting technique to reduce the natural alpha counts in the energy region where plutonium and other transuranic alpha emitters are present, and using a novel algorithm to strip out radon daughter contribution to actual beta counts. 7 figs.

  7. Turbulence of high-beta plasma

    International Nuclear Information System (INIS)

    Khvesyuk, V.I.; Chirkov, A.Y.

    1999-01-01

    Principals of numerical modelling of turbulence in high-beta plasma (β > 0.1) are discussed. Creation of transport model for axial symmetric nonuniform confining magnetic field is considered. Numerical model of plasma turbulence in FRC is presented. The physical and mathematical models are formulated from nonuniform axial symmetric high-beta plasma. It is shown that influence of waves arise under this plasma conditions lead to chaotic motion of charged particles across magnetic field. (author)

  8. Double beta decay of 82Se

    International Nuclear Information System (INIS)

    Elliott, S.R.; Hahn, A.A.; Moe, M.K.; Nelson, M.A.; Vient, M.A.

    1992-01-01

    The two-neutrino double beta decay of 82 Se has been measured during a 20 244 h run resulting in a half-life of 1.08 -0.06 +0.26 x10 20 years (68% C.L.). No candidate events for the zero-neutrino double beta decay during 21 924 h results in a half-life limit of 2.7x10 22 years at the 68% confidence level

  9. Search for the forbidden decays η→3γ and η→π0γ and the rare decay η→π0π0γγ

    International Nuclear Information System (INIS)

    Nefkens, B.M.K.; Prakhov, S.; Clajus, M.; Marusic, A.; McDonald, S.; Phaisangittisakul, N.; Price, J.W.; Starostin, A.; Tippens, W.B.; Allgower, C.E.; Spinka, H.; Bekrenv, V.; Koulbardis, A.; Kozlenko, N.; Kruglov, S.; Lopatin, I.; Briscoe, W.J.; Shafi, A.; Comfort, J.R.; Craig, K.

    2005-01-01

    A new upper limit is presented for the branching ratio (BR) of η→3γ. This decay is not allowed by charge-conjugation invariance. We have determined that BR(η→3γ) -5 . We also obtained BR(η→π 0 γ→3γ) -5 ; this decay mode is absolutely forbidden, as it violates conservation of angular momentum. Finally, we have established that BR(η→π 0 π 0 γγ) -3 in a restricted diphoton-energy region. All three upper limits are at the 90% confidence level. They were obtained by using the Crystal Ball multiphoton spectrometer at the AGS and are based on the analysis of 28 million η mesons produced in the π - p→ηn reaction close to threshold

  10. Isotope Effects in the Bonds of beta-CrOOH and beta-CrOOD

    DEFF Research Database (Denmark)

    Nørlund Christensen, A.; Hansen, P.; Lehmann, M. S.

    1976-01-01

    Samples of orthorhombic chromium oxide hydroxide, beta -CrOOH, and the deuterated compound, beta -CrOOD, were prepared hydrothermally. The crystal structures were determined by powder profile refinement technique using neutron diffraction data. Unit cells are: beta -CrOOH: a equals 4. 862(2) A, b...... equals 4. 298(a) A, c equals 2. 995(1) A; beta -CrOOD: a equals 4. 873(5) A, b equals 4. 332(7) A, c equals 2. 963(2) A, with Z equals 2. The space group is P2//1nm or Pnnm....

  11. Production of beta-xylanase and beta-xylosidase by the extremely halophilic archaeon Halorhabdus utahensis

    DEFF Research Database (Denmark)

    Wainø, M.; Ingvorsen, K.

    2003-01-01

    -xylosidase stabilities, approximately 55% and 83% of the initial beta-xylanase and beta-xylosidase activities, respectively, remained after 24 h incubation at 20% NaCl. The enzymes were also shown to be slightly thermophilic: P-xylanase activity exhibiting two optima at 55degrees and 70degreesC, while beta......The extremely halophilic archaeon, Halorhabdus utahensis, isolated from the Great Salt Lake, Utah, produced beta-xylanase and beta-xylosidase activities. Both enzymes were active over a broad NaCl range from near zero to 30% NaCl when tested with culture broth. A broad NaCl optimum was observed...... for beta-xylanase activity between 5% and 15% NaCl, while beta-xylosidase activity was highest at 5% NaCl. Almost half of the maximum activities remained at 27%-30% NaCl for both enzyme activities. When dialyzed culture supernatant and culture broth were employed for determination of beta-xylanase and beta...

  12. Evaluation of partial beta-adrenoceptor agonist activity.

    Science.gov (United States)

    Lipworth, B J; Grove, A

    1997-01-01

    A partial beta-adrenoceptor (beta-AR) agonist will exhibit opposite agonist and antagonist activity depending on the prevailing degree of adrenergic tone or the presence of a beta-AR agonist with higher intrinsic activity. In vivo partial beta-AR agonist activity will be evident at rest with low endogenous adrenergic tone, as for example with chronotropicity (beta 1/beta 2), inotropicity (beta 1) or peripheral vasodilatation and finger tremor (beta 2). beta-AR blocking drugs which have partial agonist activity may exhibit a better therapeutic profile when used for hypertension because of maintained cardiac output without increased systemic vascular resistance, along with an improved lipid profile. In the presence of raised endogenous adrenergic tone such as exercise or an exogenous full agonist, beta-AR subtype antagonist activity will become evident in terms of effects on exercise induced heart rate (beta 1) and potassium (beta 2) responses. Reduction of exercise heart rate will occur to a lesser degree in the case of a beta-adrenoceptor blocker with partial beta 1-AR agonist activity compared with a beta-adrenoceptor blocker devoid of partial agonist activity. This may result in reduced therapeutic efficacy in the treatment of angina on effort when using beta-AR blocking drugs with partial beta 1-AR agonist activity. Effects on exercise hyperkalaemia are determined by the balance between beta 2-AR partial agonist activity and endogenous adrenergic activity. For predominantly beta 2-AR agonist such as salmeterol and salbutamol, potentiation of exercise hyperkalaemia occurs. For predominantly beta 2-AR antagonists such as carteolol, either potentiation or attenuation of exercise hyperkalaemia occurs at low and high doses respectively. beta 2-AR partial agonist activity may also be expressed as antagonism in the presence of an exogenous full agonist, as for example attenuation of fenoterol induced responses by salmeterol. Studies are required to investigate whether

  13. New limit for the half-life of double beta decay of {sup 94}Zr to the first excited state of {sup 94}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Dokania, N.; Nanal, V.; Gupta, G.; Pillay, R.G.; Ghosh, C. [Tata Institute of Fundamental Research, Department of Nuclear and Atomic Physics, Mumbai (India); Pal, S. [Tata Institute of Fundamental Research, Pelletron Linac Facility, Mumbai (India); Rath, P.K. [University of Lucknow, Department of Physics, Lucknow (India); Tretyak, V.I. [Institute for Nuclear Research, Kyiv (Ukraine); Garai, A.; Krishnamoorthy, H. [Tata Institute of Fundamental Research, India-based Neutrino Observatory, Mumbai (India); Homi Bhabha National Institute, Mumbai (India); Raina, P.K. [Indian Institute of Technology, Department of Physics, Rupnagar (India); Bhushan, K.G. [Bhabha Atomic Research Centre, Technical Physics Division, Mumbai (India)

    2017-04-15

    Neutrinoless double beta decay is a phenomenon of fundamental interest in particle physics. The decay rates of double beta decay transitions to the excited states can provide input for Nuclear Transition Matrix Element calculations for the relevant two neutrino double beta decay process. It can be useful as supplementary information for the calculation of Nuclear Transition Matrix Element for the neutrinoless double beta decay process. In the present work, double beta decay of {sup 94}Zr to the 2{sup +}{sub 1} excited state of {sup 94}Mo at 871.1 keV is studied using a low background ∝ 230 cm{sup 3} HPGe detector. No evidence of this decay was found with a 232 g.y exposure of natural zirconium. The lower half-life limit obtained for the double beta decay of {sup 94}Zr to the 2{sup +}{sub 1} excited state of {sup 94}Mo is T{sub 1/2}(0ν + 2ν) > 3.4 x 10{sup 19} y at 90% C.L., an improvement by a factor of ∝ 4 over the existing experimental limit at 90% C.L. The sensitivity is estimated to be T{sub 1/2} (0ν + 2ν) > 2.0 x 10{sup 19} y at 90% C.L. using the Feldman-Cousins method. (orig.)

  14. Beta adrenergic receptors in human cavernous tissue

    Energy Technology Data Exchange (ETDEWEB)

    Dhabuwala, C.B.; Ramakrishna, C.V.; Anderson, G.F.

    1985-04-01

    Beta adrenergic receptor binding was performed with /sup 125/I iodocyanopindolol on human cavernous tissue membrane fractions from normal tissue and transsexual procedures obtained postoperatively, as well as from postmortem sources. Isotherm binding studies on normal fresh tissues indicated that the receptor density was 9.1 fmoles/mg. with a KD of 23 pM. Tissue stored at room temperature for 4 to 6 hours, then at 4C in saline solution for 19 to 20 hours before freezing showed no significant changes in receptor density or affinity, and provided evidence for the stability of postmortem tissue obtained within the same time period. Beta receptor density of 2 cavernous preparations from transsexual procedures was not significantly different from normal control tissues, and showed that high concentrations of estrogen received by these patients had no effect on beta adrenergic receptor density. Displacement of /sup 125/iodocyanopindolol by 5 beta adrenergic agents demonstrated that 1-propranolol had the greatest affinity followed by ICI 118,551, zinterol, metoprolol and practolol. When the results of these displacement studies were subjected to Scatfit, non- linear regression line analysis, a single binding site was described. Based on the relative potency of the selective beta adrenergic agents it appears that these receptors were of the beta 2 subtype.

  15. The role of hydrogen bonds in order-disorder transition of a new incommensurate low temperature phase beta-[Zn-(C.sub.7./sub.H.sub.4./sub.NO.sub.4./sub.).sub.2./sub.]·3H.sub.2./sub.O

    Czech Academy of Sciences Publication Activity Database

    Tabatabaee, M.; Poupon, Morgane; Eigner, Václav; Vaněk, Přemysl; Dušek, Michal

    2018-01-01

    Roč. 233, č. 1 (2018), s. 17-25 ISSN 2194-4946 R&D Projects: GA ČR(CZ) GA15-12653S; GA MŠk(CZ) LO1603 EU Projects: European Commission(CZ) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : aperiodic structure * hydrogen bonds * incommensurate modulation * phase transition * zinc Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.179, year: 2016

  16. Other characterizations of $\\beta$-$\\theta$-R0 topological spaces

    OpenAIRE

    Miguel Caldas Cueva

    2013-01-01

    In this paper we give other characterizations of $\\beta$-$\\theta$-$%R_0$ and also introduce a new separation axiom called$\\beta$-$\\theta$-$R_1$. It turns out that $\\beta$-$\\theta$-$R_1$ isstronger that $\\beta$-$\\theta$-$R_0$

  17. Estimating Security Betas Using Prior Information Based on Firm Fundamentals

    NARCIS (Netherlands)

    Cosemans, Mathijs; Frehen, Rik; Schotman, Peter; Bauer, Rob

    2016-01-01

    We propose a hybrid approach for estimating beta that shrinks rolling window estimates toward firm-specific priors motivated by economic theory. Our method yields superior forecasts of beta that have important practical implications. First, unlike standard rolling window betas, hybrid betas carry a

  18. Beta decay and rhenium cosmochronology

    International Nuclear Information System (INIS)

    Ashktorab, K.

    1992-01-01

    Among the problems which limit the use of the 187 Re/ 187 Os isobaric pair as a cosmochronometer for the age of the galaxy and the universe are the uncertainties in the partial half-lives of the continuum and bound state decays of 187 Re. While the total half-life of the decay is well established, the partial half-life for the continuum decay is uncertain, and several measurements are not compatible. A high temperature quartz proportional counter was used in this work to remeasure the continuum β - decay of 187 Re. The β endpoint energy for the decay of neutral 187 Re to singly ionized 187 Os of 2.75 ± 0.06 keV agrees with the earlier results. The corresponding half-life of (45 ± 3) x 10 9 years improves and agrees with the earlier measurement of Payne and Drever and refutes other measurements. Based on the new half-life for the continuum decay and a total half-life of (43.5 ± 1.3) x 10 9 years reported by Linder et al., the branching ratio for the bound state decay into discrete atomic states is estimated to be (3 ± 6)% in agreement with the most recent calculated theoretical branching ratio of approximately 1%. Anomalies in beta spectra reported by J.J. Simpson and others have been attributed to a 17 keV heavy-neutrino admixture. If confirmed, the implications from the existence of such a neutrino for particle and astrophysics would be significant. A multiwire open-quotes wall-lessclose quotes stainless steel proportional counter has been used in the present work to investigate the spectral shape of the β decay of 63 Ni. No anomalies in the spectral shape were observed which could be attributed to the presence of 17 keV heavy neutrino

  19. Beta2- and beta3-adrenoceptors activate glucose uptake in chick astrocytes by distinct mechanisms: a mechanism for memory enhancement?

    Science.gov (United States)

    Hutchinson, Dana S; Summers, Roger J; Gibbs, Marie E

    2007-11-01

    Isoprenaline, acting at beta-adrenoceptors (ARs), enhances memory formation in single trial discriminated avoidance learning in day-old chicks by mechanisms involving alterations in glucose and glycogen metabolism. Earlier studies of memory consolidation in chicks indicated that beta3-ARs enhanced memory by increasing glucose uptake, whereas beta2-ARs enhance memory by increasing glycogenolysis. This study examines the ability of beta-ARs to increase glucose uptake in chick forebrain astrocytes. The beta-AR agonist isoprenaline increased glucose uptake in a concentration-dependent manner, as did insulin. Glucose uptake was increased by the beta2-AR agonist zinterol and the beta3-AR agonist CL316243, but not by the beta1-AR agonist RO363. In chick astrocytes, reverse transcription-polymerase chain reaction studies showed that beta1-, beta2-, and beta3-AR mRNA were present, whereas radioligand-binding studies showed the presence of only beta2- and beta3-ARs. beta-AR or insulin-mediated glucose uptake was inhibited by phosphatidylinositol-3 kinase and protein kinase C inhibitors, suggesting a possible interaction between the beta-AR and insulin pathways. However beta2- and beta3-ARs increase glucose uptake by two different mechanisms: beta2-ARs via a Gs-cAMP-protein kinase A-dependent pathway, while beta3-ARs via interactions with Gi. These results indicate that activation of beta2- and beta3-ARs causes glucose uptake in chick astrocytes by distinct mechanisms, which may be relevant for memory enhancement.

  20. Exercise- and cold-induced changes in plasma beta-endorphin and beta-lipotropin in men and women.

    Science.gov (United States)

    Viswanathan, M; Van Dijk, J P; Graham, T E; Bonen, A; George, J C

    1987-02-01

    The plasma beta-endorphin (beta-EP) and beta-lipotropin (beta-LPH) response of men, eumenorrheic women, and amenorrheic women (n = 6) to 1 h of rest or to a bicycle ergometer test [20 min at 30% maximum O2 uptake (VO2max), 20 min at 60% VO2max, and at 90% VO2max to exhaustion] was studied in both normal (22 degrees C) and cold (5 degrees C) environments. beta-EP and beta-LPH was measured by radioimmunoassay in venous samples collected every 20 min during rest or after each exercise bout. Exhaustive exercise at ambient temperature (Ta) 22 degrees C induced significant increases in plasma beta-EP and beta-LPH in all subjects as did work at 60% VO2max in amenorrheic and eumenorrheic women. During work at Ta 5 degrees C, the relative increase in beta-EP and beta-LPH was suppressed in eumenorrheic women and completely prevented in amenorrheic women. Although significant lowering of beta-EP and beta-LPH was observed in men and eumenorrheic women during rest at 5 degrees C, amenorrheic women maintained precold exposure levels. These findings suggest that plasma beta-EP and beta-LPH may reflect a thermoregulatory response to heat load. There appears to be a sexual dimorphism in exercise- and cold-induced release of beta-EP and beta-LPH and amenorrhea may be accompanied by alterations in these responses.