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Sample records for p1-approximation

  1. The P1approximation in the transport of beta rays

    International Nuclear Information System (INIS)

    Legarda, F.; Idoeta, R.; Herranz, M.

    1994-01-01

    A validation test for the p1 approximation to the linear transport of electrons in planar geometry has been performed. The p1 approximation is shown to be a good option for the description of the transport of beta rays with endpoint energies between 400kev and 3.5Mev through aluminium foils . This approximation together with the use of only elastic interactions of electrons with atoms has found good agreement with experimental results . A calculation has been made of the fraction of transmitted electrons through foils, solving the transport equation for planar geometry in the p1 approximation and assuming that only elastic scattering processes take place. The boundary condition at the entrance of the foil was a collimated beta source, while at the end of the foil has been adopted a vaccum boundary condition.Sources considered are those for which experimental and calculated spectrum shapes are known to agree. The calculated fractional transmission through different absorber thicknesses is found to have an exponential shape . Besides this fact the attenuation coefficients found ,when compared with those empirically obtained, agree to within 5%. 1 fig.; 4 refs. (author)

  2. Multigroup neutron transport equation in the diffusion and P{sub 1} approximation

    Energy Technology Data Exchange (ETDEWEB)

    Obradovic, D [Boris Kidric Institute of nuclear sciences Vinca, Belgrade (Yugoslavia)

    1970-07-01

    Investigations of the properties of the multigroup transport operator, width and without delayed neutrons in the diffusion and P{sub 1} approximation, is performed using Keldis's theory of operator families as well as a technique . recently used for investigations into the properties of the general linearized Boltzmann operator. It is shown that in the case without delayed neutrons, multigroup transport operator in the diffusion and P{sub 1} approximation possesses a complete set of generalized eigenvectors. A formal solution to the initial value problem is also given. (author)

  3. Variational P1 approximations of general-geometry multigroup transport problems

    International Nuclear Information System (INIS)

    Rulko, R.P.; Tomasevic, D.; Larsen, E.W.

    1995-01-01

    A variational approximation is developed for general-geometry multigroup transport problems with arbitrary anisotropic scattering. The variational principle is based on a functional that approximates a reaction rate in a subdomain of the system. In principle, approximations that result from this functional ''optimally'' determine such reaction rates. The functional contains an arbitrary parameter α and requires the approximate solutions of a forward and an adjoint transport problem. If the basis functions for the forward and adjoint solutions are chosen to be linear functions of the angular variable Ω, the functional yields the familiar multigroup P 1 equations for all values of α. However, the boundary conditions that result from the functional depend on α. In particular, for problems with vacuum boundaries, one obtains the conventional mixed boundary condition, but with an extrapolation distance that depends continuously on α. The choice α = 0 yields a generalization of boundary conditions derived earlier by Federighi and Pomraning for a more limited class of problems. The choice α = 1 yields a generalization of boundary conditions derived previously by Davis for monoenergetic problems. Other boundary conditions are obtained by choosing different values of α. The authors discuss this indeterminancy of α in conjunction with numerical experiments

  4. Neutron wave reflexions in interface media with transport equation P1 approximation

    International Nuclear Information System (INIS)

    Oliveira Vellozo, S. de.

    1977-01-01

    The propagation of neutron waves in non multiplying media is investigated employing the Telegrapher's equation obtained from the P 1 approximation of the time, space and energy dependent Boltzmann equation. Solution of the problem of propagation of sinusoidally modulated source incident on one face of the medium is obtained by analysing the Fourier component of a pulsed source introduced, for the corresponding frequency. The amplitude and the phase of the flux are computed as a function of frequency in media consisting of one, two and three regions in order to study the effects of reflection at the interfaces. The results are compared with those from the Diffusion approximation obtained by neglecting the term involving the second order time derivative. (author)

  5. Finite Element Approximation of the FENE-P Model

    OpenAIRE

    Barrett , John ,; Boyaval , Sébastien

    2017-01-01

    We extend our analysis on the Oldroyd-B model in Barrett and Boyaval [1] to consider the finite element approximation of the FENE-P system of equations, which models a dilute polymeric fluid, in a bounded domain $D $\\subset$ R d , d = 2 or 3$, subject to no flow boundary conditions. Our schemes are based on approximating the pressure and the symmetric conforma-tion tensor by either (a) piecewise constants or (b) continuous piecewise linears. In case (a) the velocity field is approximated by c...

  6. The P1-approximation for the Distribution of Neutrons from a Pulsed Source in Hydrogen

    International Nuclear Information System (INIS)

    Claesson, A.

    1963-12-01

    The asymptotic distribution of neutrons from a pulsed, high energy source in an infinite moderator has been obtained earlier in a 'diffusion' approximation. In that paper the cross section was assumed to be constant over the whole energy region and the time derivative of the first moment was disregarded. Here, first, an analytic expression is obtained for the density in a P 1 -approximation. However, the result is very complicated, and it is shown that an asymptotic solution can be found in a simpler way. By taking into account the low hydrogen scattering cross section at the source energy it follows that the space dependence of the distribution is less than that obtained earlier. The importance of keeping the time derivative of the first moment is further shown in a perturbation approximation

  7. SHADOK-3-6, Transport Equation with Anisotropic Diffusion in P1 Approximation for Spherical and Cylindrical Geometry

    International Nuclear Information System (INIS)

    Ligou, J.; Thomi, P.A.

    1973-01-01

    1 - Nature of physical problem solved: Integral transport equation, anisotropy of diffusion in P1 approximation. SHADOK3 - cylindrical geometry; direct solution of the linear system. SHADOK4 - cylindrical geometry; Thermalization iteration; solution of the linear system with inverse matrix calculation. SHADOK5 - like SHADOK3 for spherical geometry. SHADOK6 - like SHADOK4 for spherical geometry. 2 - Method of solution: Analysis in terms of annuli for each of which polynomial approximation is applied. Dynamic allocation (for formulas see report TM(10)). 3 - Restrictions on the complexity of the problem: Relative accuracy of the Bickley functions about 1.0E-13

  8. The P{sub 1}-approximation for the Distribution of Neutrons from a Pulsed Source in Hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Claesson, A

    1963-12-15

    The asymptotic distribution of neutrons from a pulsed, high energy source in an infinite moderator has been obtained earlier in a 'diffusion' approximation. In that paper the cross section was assumed to be constant over the whole energy region and the time derivative of the first moment was disregarded. Here, first, an analytic expression is obtained for the density in a P{sub 1} -approximation. However, the result is very complicated, and it is shown that an asymptotic solution can be found in a simpler way. By taking into account the low hydrogen scattering cross section at the source energy it follows that the space dependence of the distribution is less than that obtained earlier. The importance of keeping the time derivative of the first moment is further shown in a perturbation approximation.

  9. Some approximation properties of ( p , q $(p,q$ -Bernstein operators

    Directory of Open Access Journals (Sweden)

    Shin Min Kang

    2016-06-01

    Full Text Available Abstract This paper is concerned with the ( p , q $(p,q$ -analog of Bernstein operators. It is proved that, when the function is convex, the ( p , q $(p,q$ -Bernstein operators are monotonic decreasing, as in the classical case. Also, some numerical examples based on Maple algorithms that verify these properties are considered. A global approximation theorem by means of the Ditzian-Totik modulus of smoothness and a Voronovskaja type theorem are proved.

  10. Computational resources to filter gravitational wave data with P-approximant templates

    International Nuclear Information System (INIS)

    Porter, Edward K

    2002-01-01

    The prior knowledge of the gravitational waveform from compact binary systems makes matched filtering an attractive detection strategy. This detection method involves the filtering of the detector output with a set of theoretical waveforms or templates. One of the most important factors in this strategy is knowing how many templates are needed in order to reduce the loss of possible signals. In this study, we calculate the number of templates and computational power needed for a one-step search for gravitational waves from inspiralling binary systems. We build on previous works by first expanding the post-Newtonian waveforms to 2.5-PN order and second, for the first time, calculating the number of templates needed when using P-approximant waveforms. The analysis is carried out for the four main first-generation interferometers, LIGO, GEO600, VIRGO and TAMA. As well as template number, we also calculate the computational cost of generating banks of templates for filtering GW data. We carry out the calculations for two initial conditions. In the first case we assume a minimum individual mass of 1 M o-dot and in the second, we assume a minimum individual mass of 5 M o-dot . We find that, in general, we need more P-approximant templates to carry out a search than if we use standard PN templates. This increase varies according to the order of PN-approximation, but can be as high as a factor of 3 and is explained by the smaller span of the P-approximant templates as we go to higher masses. The promising outcome is that for 2-PN templates, the increase is small and is outweighed by the known robustness of the 2-PN P-approximant templates

  11. Quasimolecular emission near the Xe(5p 56s 1,3 P 1 - 5p 6 1 S 0) and Kr (4p 55s 1,3 P 1 - 4p 6 1 S 0) resonance lines induced by collisions with He atoms

    Science.gov (United States)

    Alekseeva, O. S.; Devdariani, A. Z.; Grigorian, G. M.; Lednev, M. G.; Zagrebin, A. L.

    2017-02-01

    This study is devoted to the theoretical investigation of the quasimolecular emission of Xe*-He and Kr*-He collision pairs near the Xe (5p 56s 1,3 P 1 - 5p 6 1 S 0) and Kr (4p 55s 1,3 P 1 - 4p 6 1 S 0) resonance atomic lines. The potential curves of the quasimolecules Xe(5p 56s) + He and Kr(4p 55s) + He have been obtained with the use of the effective Hamiltonian and pseudopotential methods. Based on these potential curves the processes of quasimolecular emission of Xe*+He and Kr*+He mixtures have been considered and the spectral distributions I(ħΔω) of photons emitted have been obtained in the framework of quasistatic approximation.

  12. Improved radiative corrections for (e,e'p) experiments: Beyond the peaking approximation and implications of the soft-photon approximation

    International Nuclear Information System (INIS)

    Weissbach, F.; Hencken, K.; Rohe, D.; Sick, I.; Trautmann, D.

    2006-01-01

    Analyzing (e,e ' p) experimental data involves corrections for radiative effects which change the interaction kinematics and which have to be carefully considered in order to obtain the desired accuracy. Missing momentum and energy due to bremsstrahlung have so far often been incorporated into the simulations and the experimental analyses using the peaking approximation. It assumes that all bremsstrahlung is emitted in the direction of the radiating particle. In this article we introduce a full angular Monte Carlo simulation method which overcomes this approximation. As a test, the angular distribution of the bremsstrahlung photons is reconstructed from H(e,e ' p) data. Its width is found to be underestimated by the peaking approximation and described much better by the approach developed in this work. The impact of the soft-photon approximation on the photon angular distribution is found to be minor as compared to the impact of the peaking approximation. (orig.)

  13. An Approximate L p Difference Algorithm for Massive Data Streams

    Directory of Open Access Journals (Sweden)

    Jessica H. Fong

    2001-12-01

    Full Text Available Several recent papers have shown how to approximate the difference ∑ i |a i-b i | or ∑|a i-b i | 2 between two functions, when the function values a i and b i are given in a data stream, and their order is chosen by an adversary. These algorithms use little space (much less than would be needed to store the entire stream and little time to process each item in the stream. They approximate with small relative error. Using different techniques, we show how to approximate the L p-difference ∑ i |a i-b i | p for any rational-valued p∈(0,2], with comparable efficiency and error. We also show how to approximate ∑ i |a i-b i | p for larger values of p but with a worse error guarantee. Our results fill in gaps left by recent work, by providing an algorithm that is precisely tunable for the application at hand. These results can be used to assess the difference between two chronologically or physically separated massive data sets, making one quick pass over each data set, without buffering the data or requiring the data source to pause. For example, one can use our techniques to judge whether the traffic on two remote network routers are similar without requiring either router to transmit a copy of its traffic. A web search engine could use such algorithms to construct a library of small ``sketches,'' one for each distinct page on the web; one can approximate the extent to which new web pages duplicate old ones by comparing the sketches of the web pages. Such techniques will become increasingly important as the enormous scale, distributional nature, and one-pass processing requirements of data sets become more commonplace.

  14. Space dependent neutron slowing and thermalization in monatomic hydrogen gas in the P-1 approximation

    International Nuclear Information System (INIS)

    Musazay, M.S.

    1981-01-01

    A solution to the space and energy dependent neutron transport equation in the framework of the consistent P-1 approximation is sought. The transport equation for thermal neutrons in a moderator of 1/v absorption and constant scattering cross section is changed into a set of coupled partial differential equations. The space dependent part is removed by assuming a cosine shaped flux due to a cosine shaped source at a very high energy. The resulting set of strongly coupled ordinary differential equations is decoupled by assuming expansion of collision density in the powers of a leakage parameter whose coefficients are energy and absorption dependent. These energy dependent coefficients are solutions of a set of weakly coupled differential equations. Series solutions to these differential equations in powers of epsilon and 1/epsilon, where epsilon = E/kT, E being the neutron energy and kT the moderator temperature in units of energy, are found. The properties of these solutions are studied extensively. Absorption appears as a parameter in the coefficients of the series. The difficulties arising in choosing the correct form of the asymptotic solutions are resolved by comparing slowing and thermalization. The limitations on the size of the slab and on the range of absorption are included in the analysis

  15. Universal approximation in p-mean by neural networks

    NARCIS (Netherlands)

    Burton, R.M; Dehling, H.G

    A feedforward neural net with d input neurons and with a single hidden layer of n neurons is given by [GRAPHICS] where a(j), theta(j), w(ji) is an element of R. In this paper we study the approximation of arbitrary functions f: R-d --> R by a neural net in an L-p(mu) norm for some finite measure mu

  16. Detecting gravitational waves from test-mass bodies orbiting a Kerr black hole with P-approximant templates

    International Nuclear Information System (INIS)

    Porter, Edward K

    2005-01-01

    In this study, we apply post-Newtonian (T-approximants) and resummed post-Newtonian (P-approximants) to the case of a test particle in equatorial orbit around a Kerr black hole. We compare the two approximants by measuring their effectualness (i.e., larger overlaps with the exact signal) and faithfulness (i.e., smaller biases while measuring the parameters of the signal) with the exact (numerical) waveforms. We find that in the case of prograde orbits, T-approximant templates obtain an effectualness of ∼0.99 for spins q ≤ 0.75. For 0.75 0.99 for all spins up to q = 0.95. The bias in the estimation of parameters is much lower in the case of P-approximants than T-approximants. We find that P-approximants are both effectual and faithful and should be more effective than T-approximants as a detection template family when q > 0. For q < 0, both T- and P-approximants perform equally well so that either of them could be used as a detection template family. However, for parameter estimation, the P-approximant templates still outperform the T-approximants

  17. January: IBM 7094 programme for the resolution of cell problems in planar, spherical and cylindrical geometry using the double P{sub n} approximation; Janvier: programme de resolution sur IBM 7094 des problemes de cellules en geometrie plane, spherique et cylindrique dans l'approximation double P{sub n}

    Energy Technology Data Exchange (ETDEWEB)

    Amouyal, A; Tariel, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-07-01

    Code name: January 1{sup st} SCEA 011S. 2) Computer: IBM 7094; Programme system: Fortran II, 2{sup nd} version. 3) Nature of the problem: resolution of cell problems with one space variable (planar, spherical and cylindrical geometries) and with one energy group, with isotropic sources in the double P{sub n} approximation (DP 1 and DP 3 approximation in planar and spherical geometries, DP 1 and DP 2 in cylindrical geometry). 4) Method used: the differential equations with limiting conditions are transformed into differential system with initial conditions which are integrated by a separate-step method. 5) Restrictions: number of physical media < 100, number of geometrical regions < 100, number of points < 1000. 6) Physical approximations: limiting conditions for reflection, black body or grey body (restrictions for spherical and cylindrical geometries). The diffusion can include an isotropy term in cylindrical geometry, 2 terms in the other geometries. Taking into account of macroscopic data. 7) Duration: calculation time for a network of 100 points: planar and spherical geometry: double P 1 1 second, D P 3 = 4 seconds; cylindrical geometry: double P 1 2 seconds, D P 2 = 4 seconds. To these times should be added the 3 seconds required for the output. 8) State of the programme under production. (authors) [French] 1) Nom du Code: Janvier 1 SCEA 011S. 2) Calculateur: IBM 7094; Systeme de programmation: Fortran II version-2. 3) Nature du probleme: resolution des problemes de cellule a une variable d'espace (geometries plane, spherique et cylindrique) et un groupe d'energie, avec sources isotropes, dans l'approxirnation double P{sub n} (Approximations DP 1 et DP 3 en geometrie plane et spherique, approximations DP 1 et DP 2 en geometrie cylindrique). Methode employee: les equations differentielles avec conditions aux limites sont transformees en systemes differentiels avec conditions initiales que l'on integre par une methode a pas separes. 5) Restrictions: nombre de

  18. Approximate analytical solution of two-dimensional multigroup P-3 equations

    International Nuclear Information System (INIS)

    Matausek, M.V.; Milosevic, M.

    1981-01-01

    Iterative solution of multigroup spherical harmonics equations reduces, in the P-3 approximation and in two-dimensional geometry, to a problem of solving an inhomogeneous system of eight ordinary first order differential equations. With appropriate boundary conditions, these equations have to be solved for each energy group and in each iteration step. The general solution of the corresponding homogeneous system of equations is known in analytical form. The present paper shows how the right-hand side of the system can be approximated in order to derive a particular solution and thus an approximate analytical expression for the general solution of the inhomogeneous system. This combined analytical-numerical approach was shown to have certain advantages compared to the finite-difference method or the Lie-series expansion method, which have been used to solve similar problems. (author)

  19. Approximate analytical solution of two-dimensional multigroup P-3 equations

    International Nuclear Information System (INIS)

    Matausek, M.V.; Milosevic, M.

    1981-01-01

    Iterative solution of multigroup spherical harmonics equations reduces, in the P-3 approximation and in two-dimensional geometry, to a problem of solving an inhomogeneous system of eight ordinary first order differential equations. With appropriate boundary conditions, these equations have to be solved for each energy group and in each iteration step. The general solution of the corresponding homogeneous system of equations is known in analytical form. The present paper shows how the right-hand side of the system can be approximated in order to derive a particular solution and thus an approximate analytical expression for the general solution of the inhomogeneous system. This combined analytical-numerical approach was shown to have certain advantages compared to the finite-difference method or the Lie-series expansion method, which have been used to solve similar problems. (orig./RW) [de

  20. Nuclear effects in protonium formation low-energy three-body reaction: p̄ + (pμ1s → (p̄pα + μ−: Strong p̄–p interaction in p̄ + (pμ1s

    Directory of Open Access Journals (Sweden)

    Sultanov Renat A.

    2016-01-01

    Full Text Available A three-charge-particle system (p̄, μ−, p+ with an additional matter-antimatter, i.e. p̄–p+, nuclear interaction is the subject of this work. Specifically, we carry out a few-body computation of the following protonium formation reaction: p̄ + (p+μ−1s → (p̄p+1s + μ−, where p+ is a proton, p̄ is an antiproton, μ− is a muon, and a bound state of p+ and its counterpart p̄ is a protonium atom: Pn = (p̄p+. The low-energy cross sections and rates of the Pn formation reaction are computed in the framework of a Faddeev-like equation formalism. The strong p̄–p+ interaction is approximately included in this calculation.

  1. Spline approximation, Part 1: Basic methodology

    Science.gov (United States)

    Ezhov, Nikolaj; Neitzel, Frank; Petrovic, Svetozar

    2018-04-01

    In engineering geodesy point clouds derived from terrestrial laser scanning or from photogrammetric approaches are almost never used as final results. For further processing and analysis a curve or surface approximation with a continuous mathematical function is required. In this paper the approximation of 2D curves by means of splines is treated. Splines offer quite flexible and elegant solutions for interpolation or approximation of "irregularly" distributed data. Depending on the problem they can be expressed as a function or as a set of equations that depend on some parameter. Many different types of splines can be used for spline approximation and all of them have certain advantages and disadvantages depending on the approximation problem. In a series of three articles spline approximation is presented from a geodetic point of view. In this paper (Part 1) the basic methodology of spline approximation is demonstrated using splines constructed from ordinary polynomials and splines constructed from truncated polynomials. In the forthcoming Part 2 the notion of B-spline will be explained in a unique way, namely by using the concept of convex combinations. The numerical stability of all spline approximation approaches as well as the utilization of splines for deformation detection will be investigated on numerical examples in Part 3.

  2. Vacancy-rearrangement theory in the first Magnus approximation

    International Nuclear Information System (INIS)

    Becker, R.L.

    1984-01-01

    In the present paper we employ the first Magnus approximation (M1A), a unitarized Born approximation, in semiclassical collision theory. We have found previously that the M1A gives a substantial improvement over the first Born approximation (B1A) and can give a good approximation to a full coupled channels calculation of the mean L-shell vacancy probability per electron, p/sub L/, when the L-vacancies are accompanied by a K-shell vacancy (p/sub L/ is obtained experimentally from measurements of K/sub α/-satellite intensities). For sufficiently strong projectile-electron interactions (sufficiently large Z/sub p/ or small v) the M1A ceases to reproduce the coupled channels results, but it is accurate over a much wider range of Z/sub p/ and v than the B1A. 27 references

  3. Characterization of a recurrent t(1;2)(p36;p24) in human uterine leiomyoma.

    NARCIS (Netherlands)

    Rijk, A. van; Sweers, M.A.; Huys, E.; Kersten, M.; Merkx, G.F.M.; Geurts van Kessel, A.H.M.; Debiec-Rychter, M.; Schoenmakers, E.F.P.M.

    2009-01-01

    Uterine leiomyomas are the most common neoplasms in women of reproductive age. Approximately 40% of these neoplasms show recurring structural cytogenetic anomalies, including del(7)(q22), t(12;14)(q15;q24), t(1;2)(p36;p24), and anomalies affecting 6p21 or 10q22. Using positional cloning strategies,

  4. Study of the (p,pn) reaction on 1p shell nuclei at 46 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Miller, C A

    1974-01-01

    The (p,pn) reaction on four 1p shell nuclei, /sup 6/Li, /sup 9/Be, /sup 13/C and /sup 12/C, as well as the /sup 6/Li(p,2p) reaction, have been studied at 46 MeV. The /sup 6/Li(p,pn) cross section was found to be approximately four times that for (p,2p) and to have a very different angular dependence. Both reactions show the s-state admixture in /sup 6/Li observed with (p,2p) at higher energies. For all of the target nuclei, the cross sections have features that cannot be fitted by a renormalized Plane Wave Impulse Approximation (PWIA) calculation. A zero range distorted wave calculation was found to be in only fair agreement with the /sup 9/Be and /sup 13/C data. The overall magnitudes of the results of the calculation were found to be very sensitive to the RMS radii of the bound state wave functions of the knocked-out neutrons.

  5. Effects of perinatal combined exposure to 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) and tributyltin (TBT) on rat female reproductive system.

    Science.gov (United States)

    Makita, Yuji

    2008-05-01

    1,1-Dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) is the most prevalent metabolite of DDT used as a pesticide before and tributyltin (TBT) compounds are used primarily as antifouling agents on vessels, ships, and aqua culture facilities, as they exert biocidal actions. Currently, p,p'-DDE and TBT are ubiquitously distributed in the environment and bio-accumulated in marine products, especially fish or shellfish. Thus, oral p,p'-DDE and TBT intake through marine products is demonstrated to be rather high in Japan. Consequently, the fetus and neonate will be exposed to p,p'-DDE and TBT via mother. Therefore, effects of perinatal combined exposure to p,p'-DDE and TBT on the female reproductive system after maturation have been investigated in rat female offspring of dams ingesting 125ppm p,p'-DDE (approximately 10mg/kg) and 25ppm TBT (approximately 2mg/kg) during the perinatal period from gestation to lactation. In the present study, no deleterious reproductive outcomes were recognized in p,p'-DDE and/or TBT-treated dams. In contrast, growth retardation had developed in rat female offspring following perinatal exposure to TBT and sustained even after cessation of exposures. Further, reduced ovarian weights with elevated serum follicle-stimulating hormone (FSH) concentrations were observed in the reproductive system of matured female offspring following perinatal exposure to TBT. At present, biological relevance of these alterations remains unknown, but there is a possibility that these alterations lead to reproductive malfunctions in matured female offspring. Copyright © 2007 Elsevier B.V. All rights reserved.

  6. Low-energy P-wave phaseshifts for positron-hydrogen elastic scattering using an adiabatic approximation

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Beker, C.A.; Farina, J.E.G.

    1981-01-01

    P-wave phaseshifts for positron-hydrogen elastic scattering are calculated using a new adiabatic approximation in which the length of the radius vector from the proton to the positron is fixed but its direction is allowed to vary. This adiabatic approximation makes possible the full inclusion in the calculation of virtual states in which angular momentum is transferred to the target H atom. The results obtained agree qualitatively with the highly accurate results of Bhatia and co-workers (Phys. Rev.; A9:219 (1974)) and are much closer to them than the results obtained using the usual adiabatic approximation in which the radius vector from the proton to the positron is fixed. (author)

  7. Quenched Approximation to ΔS = 1 K Decay

    International Nuclear Information System (INIS)

    Christ, Norman H.

    2005-01-01

    The importance of explicit quark loops in the amplitudes contributing to ΔS = 1, K meson decays raises potential ambiguities when these amplitudes are evaluated in the quenched approximation. Using the factorization of these amplitudes into short- and long-distance parts provided by the standard low-energy effective weak Hamiltonian, we argue that the quenched approximation can be conventionally justified if it is applied to the long-distance portion of each amplitude. The result is a reasonably well-motivated definition of the quenched approximation that is close to that employed in the RBC and CP-PACS calculations of these quantities

  8. A study of the (p,pn) reaction on 1p shell nuclei at 46 MeV

    International Nuclear Information System (INIS)

    Miller, C.A.

    1974-01-01

    The (p,pn) reaction on four 1p shell nuclei, 6 Li, 9 Be, 13 C and 12 C, as well as the 6 Li(p,2p) reaction, have been studied at 46 MeV. The 6 Li(p,pn) cross section was found to be approximately four times that for (p,2p) and to have a very different angular dependence. Both reactions show the s-state admixture in 6 Li observed with (p,2p) at higher energies. For all of the target nuclei, the cross sections have features that cannot be fitted by a renormalized Plane Wave Impulse Approximation (PWIA) calculation. A zero range distorted wave calculation was found to be in only fair agreement with the 9 Be and 13 C data. The overall magnitudes of the results of the calculation were found to be very sensitive to the RMS radii of the bound state wave functions of the knocked-out neutrons. (author)

  9. P3-approximation for gaseous media and vacuum

    International Nuclear Information System (INIS)

    Raevskaya, V.E.

    1986-01-01

    The problems connected with calculation of neutron field in a fuel assembly (FA) of a gas cooled reactor are discussed. The problem of P 3 -approximation applicability for the description of neutron fields in closed vacuum and gas volumes is considered. Under the assumption of the field azimuthal symmetry derived are the formulas for determination of the field in cylindrical vacuum layer of multizone FA as well as the solution for the cluster central zone, where the rods with vacuum between them are placed. Because of the finiteness of voids surrounded by medium it is possible to use the condition of neutron flux density continuity as the boundary conditions for the interface with vacuum. For representation of boundary conditions for rod surfaces and the cluster central zone with vacuum the addition theorems for the field in vacuum between the roads are derived. The formulas for mean neutron fluxes in vacuum cylindrical layer and in vacuum between rods are derived. The numerical calculations performed according to various programs confirmed the validity of the derived formulas

  10. Comparative analysis between P1 and B1 equations for neutron moderation

    International Nuclear Information System (INIS)

    Martinez, Aquilino Senra; Silva, Fernando Carvalho da; Cardoso, Carlos Eduardo Santos

    2000-01-01

    In order to calculate the neutron flux in nuclear reactors, B1 or P1 equations are solved by numerical methods for several groups of energy. The neutron fluxes obtained from the solutions of the B1 and P1 equations are similar when they are applied to large nuclear power reactors. However, an important difference between the two fluxes is that the system of P1 equations uses one more approximation than the B1 system and then, its flux is less precise. The present work shows the relations between both equations and analyzes for what conditions the two equations systems are equivalent. Furthermore, this equations are numerically solved in 54 groups of energy for a quadrangular arrange. (author)

  11. Pregnane X receptor-dependent induction of the CYP3A4 gene by o,p'-1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane.

    Science.gov (United States)

    Medina-Díaz, Irma M; Arteaga-Illán, Georgina; de León, Mario Bermudez; Cisneros, Bulmaro; Sierra-Santoyo, Adolfo; Vega, Libia; Gonzalez, Frank J; Elizondo, Guillermo

    2007-01-01

    CYP3A4, the predominant cytochrome P450 (P450) expressed in human liver and intestine, contributes to the metabolism of approximately half the drugs in clinical use today. CYP3A4 catalyzes the 6beta-hydroxylation of a number of steroid hormones and is involved in the bioactivation of environmental procarcinogens. The expression of CYP3A4 is affected by several stimuli, including environmental factors such as insecticides and pesticides. The o,p'-1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane (DDT) isomer of DDT comprises approximately 20% of technical grade DDT, which is an organochloride pesticide. We have recently shown that o,p'-DDT exposure increases CYP3A4 mRNA levels in HepG2 cells. To determine the mechanism by which o,p'-DDT induces CYP3A4 expression, transactivation and electrophoretic mobility shift assays were carried out, revealing that o,p'-DDT activates the CYP3A4 gene promoter through the pregnane X receptor (PXR). CYP3A4 gene promoter activation resulted in both an increase in CYP3A4 mRNA levels and an increase in the total CYP3A4 activity in HepG2 cells. We also observed induction of CYP3A4 and mouse Cyp3a11 mRNA in the intestine of CYP3A4-transgenic mice after exposure to 1 mg/kg o,p'-DDT. At higher doses, a decrease of CYP3A4 inducibility was observed together with an increase in levels of interleukin 6 mRNA, a proinflammatory cytokine that strongly represses CYP3A4 transcription. The present study indicates that regulation of other genes under PXR control may be altered by o,p'-DDT exposure.

  12. Exogenous S1P Exposure Potentiates Ischemic Stroke Damage That Is Reduced Possibly by Inhibiting S1P Receptor Signaling.

    Science.gov (United States)

    Moon, Eunjung; Han, Jeong Eun; Jeon, Sejin; Ryu, Jong Hoon; Choi, Ji Woong; Chun, Jerold

    2015-01-01

    Initial and recurrent stroke produces central nervous system (CNS) damage, involving neuroinflammation. Receptor-mediated S1P signaling can influence neuroinflammation and has been implicated in cerebral ischemia through effects on the immune system. However, S1P-mediated events also occur within the brain itself where its roles during stroke have been less well studied. Here we investigated the involvement of S1P signaling in initial and recurrent stroke by using a transient middle cerebral artery occlusion/reperfusion (M/R) model combined with analyses of S1P signaling. Gene expression for S1P receptors and involved enzymes was altered during M/R, supporting changes in S1P signaling. Direct S1P microinjection into the normal CNS induced neuroglial activation, implicating S1P-initiated neuroinflammatory responses that resembled CNS changes seen during initial M/R challenge. Moreover, S1P microinjection combined with M/R potentiated brain damage, approximating a model for recurrent stroke dependent on S1P and suggesting that reduction in S1P signaling could ameliorate stroke damage. Delivery of FTY720 that removes S1P signaling with chronic exposure reduced damage in both initial and S1P-potentiated M/R-challenged brain, while reducing stroke markers like TNF-α. These results implicate direct S1P CNS signaling in the etiology of initial and recurrent stroke that can be therapeutically accessed by S1P modulators acting within the brain.

  13. Exogenous S1P Exposure Potentiates Ischemic Stroke Damage That Is Reduced Possibly by Inhibiting S1P Receptor Signaling

    Directory of Open Access Journals (Sweden)

    Eunjung Moon

    2015-01-01

    Full Text Available Initial and recurrent stroke produces central nervous system (CNS damage, involving neuroinflammation. Receptor-mediated S1P signaling can influence neuroinflammation and has been implicated in cerebral ischemia through effects on the immune system. However, S1P-mediated events also occur within the brain itself where its roles during stroke have been less well studied. Here we investigated the involvement of S1P signaling in initial and recurrent stroke by using a transient middle cerebral artery occlusion/reperfusion (M/R model combined with analyses of S1P signaling. Gene expression for S1P receptors and involved enzymes was altered during M/R, supporting changes in S1P signaling. Direct S1P microinjection into the normal CNS induced neuroglial activation, implicating S1P-initiated neuroinflammatory responses that resembled CNS changes seen during initial M/R challenge. Moreover, S1P microinjection combined with M/R potentiated brain damage, approximating a model for recurrent stroke dependent on S1P and suggesting that reduction in S1P signaling could ameliorate stroke damage. Delivery of FTY720 that removes S1P signaling with chronic exposure reduced damage in both initial and S1P-potentiated M/R-challenged brain, while reducing stroke markers like TNF-α. These results implicate direct S1P CNS signaling in the etiology of initial and recurrent stroke that can be therapeutically accessed by S1P modulators acting within the brain.

  14. A faster 1.375-approximation algorithm for sorting by transpositions.

    Science.gov (United States)

    Cunha, Luís Felipe I; Kowada, Luis Antonio B; Hausen, Rodrigo de A; de Figueiredo, Celina M H

    2015-11-01

    Sorting by Transpositions is an NP-hard problem for which several polynomial-time approximation algorithms have been developed. Hartman and Shamir (2006) developed a 1.5-approximation [Formula: see text] algorithm, whose running time was improved to O(nlogn) by Feng and Zhu (2007) with a data structure they defined, the permutation tree. Elias and Hartman (2006) developed a 1.375-approximation O(n(2)) algorithm, and Firoz et al. (2011) claimed an improvement to the running time, from O(n(2)) to O(nlogn), by using the permutation tree. We provide counter-examples to the correctness of Firoz et al.'s strategy, showing that it is not possible to reach a component by sufficient extensions using the method proposed by them. In addition, we propose a 1.375-approximation algorithm, modifying Elias and Hartman's approach with the use of permutation trees and achieving O(nlogn) time.

  15. Approximation properties of haplotype tagging

    Directory of Open Access Journals (Sweden)

    Dreiseitl Stephan

    2006-01-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs are locations at which the genomic sequences of population members differ. Since these differences are known to follow patterns, disease association studies are facilitated by identifying SNPs that allow the unique identification of such patterns. This process, known as haplotype tagging, is formulated as a combinatorial optimization problem and analyzed in terms of complexity and approximation properties. Results It is shown that the tagging problem is NP-hard but approximable within 1 + ln((n2 - n/2 for n haplotypes but not approximable within (1 - ε ln(n/2 for any ε > 0 unless NP ⊂ DTIME(nlog log n. A simple, very easily implementable algorithm that exhibits the above upper bound on solution quality is presented. This algorithm has running time O((2m - p + 1 ≤ O(m(n2 - n/2 where p ≤ min(n, m for n haplotypes of size m. As we show that the approximation bound is asymptotically tight, the algorithm presented is optimal with respect to this asymptotic bound. Conclusion The haplotype tagging problem is hard, but approachable with a fast, practical, and surprisingly simple algorithm that cannot be significantly improved upon on a single processor machine. Hence, significant improvement in computatational efforts expended can only be expected if the computational effort is distributed and done in parallel.

  16. Electronic band structure calculations for GaxIn1−xASyP1−y alloys lattice matched to InP

    International Nuclear Information System (INIS)

    Bechiri, A; Benmakhlouf, F; Allouache, H; Bacha, S; Bouarissa, N

    2012-01-01

    A pseudopotential formalism coupled with the virtual crystal approximation are applied to study the effect of compositional disorder upon electronic band structure of cubic Ga x In 1−x As y P 1−y quarternary alloys lattice matched to InP. The effects of compositional variations are properly included in the calculations. Very good agreement is obtained between the calculated values and the available experimental data for the lattice–matched alloy to InP. The absorption at the fundamental optical gaps is found to be direct within a whole range of the y composition whatever the lattice-matching to the substrate of interest. The alloy system Ga x In 1−x As y P 1−y lattice matched to InP is suggested to be suitable for an efficient light emitting device (ELED) material.

  17. Approximate supernova remnant dynamics with cosmic ray production

    Science.gov (United States)

    Voelk, H. J.; Drury, L. O.; Dorfi, E. A.

    1985-01-01

    Supernova explosions are the most violent and energetic events in the galaxy and have long been considered probably sources of Cosmic Rays. Recent shock acceleration models treating the Cosmic Rays (CR's) as test particles nb a prescribed Supernova Remnant (SNR) evolution, indeed indicate an approximate power law momentum distribution f sub source (p) approximation p(-a) for the particles ultimately injected into the Interstellar Medium (ISM). This spectrum extends almost to the momentum p = 1 million GeV/c, where the break in the observed spectrum occurs. The calculated power law index approximately less than 4.2 agrees with that inferred for the galactic CR sources. The absolute CR intensity can however not be well determined in such a test particle approximation.

  18. Approximate supernova remnant dynamics with cosmic ray production

    International Nuclear Information System (INIS)

    Voelk, H.J.; Drury, L.O.; Dorfi, E.A.

    1985-01-01

    Supernova explosions are the most violent and energetic events in the galaxy and have long been considered probable sources of cosmic rays. Recent shock acceleration models treating the cosmic rays (CR's) as test particles nb a prescribed supernova remnant (SNR) evolution, indeed indicate an approximate power law momentum distribution f sub source (p) approximation p(-a) for the particles ultimately injected into the interstellar medium (ISM). This spectrum extends almost to the momentum p = 1 million GeV/c, where the break in the observed spectrum occurs. The calculated power law index approximately less than 4.2 agrees with that inferred for the galactic CR sources. The absolute CR intensity can however not be well determined in such a test particle approximation

  19. Precise analytic approximations for the Bessel function J1 (x)

    Science.gov (United States)

    Maass, Fernando; Martin, Pablo

    2018-03-01

    Precise and straightforward analytic approximations for the Bessel function J1 (x) have been found. Power series and asymptotic expansions have been used to determine the parameters of the approximation, which is as a bridge between both expansions, and it is a combination of rational and trigonometric functions multiplied with fractional powers of x. Here, several improvements with respect to the so called Multipoint Quasirational Approximation technique have been performed. Two procedures have been used to determine the parameters of the approximations. The maximum absolute errors are in both cases smaller than 0.01. The zeros of the approximation are also very precise with less than 0.04 per cent for the first one. A second approximation has been also determined using two more parameters, and in this way the accuracy has been increased to less than 0.001.

  20. Gaussian and 1/N approximations in semiclassical cosmology

    International Nuclear Information System (INIS)

    Mazzitelli, F.D.; Paz, J.P.

    1989-01-01

    We study the λphi 4 theory and the interacting O(N) model in a curved background using the Gaussian approximation for the former and the large-N approximation for the latter. We obtain the renormalized version of the semiclassical Einstein equations having in mind a future application of these models to investigate the physics of the very early Universe. We show that, while the Gaussian approximation has two different phases, in the large-N limit only one is present. The different features of the two phases are analyzed at the level of the effective field equations. We discuss the initial-value problem and find the initial conditions that make the theory renormalizable. As an example, we study the de Sitter self-consistent solutions of the semiclassical Einstein equations. Finally, for an identically zero mean value of the field we find the evolution equations for the classical field Ω(x) = (λ 2 >)/sup 1/2/ and the spacetime metric. They are very similar to the ones obtained by replacing the classical potential by the one-loop effective potential in the classical equations but do not have the drawbacks of the one-loop approximation

  1. A fast algorithm for determining bounds and accurate approximate p-values of the rank product statistic for replicate experiments.

    Science.gov (United States)

    Heskes, Tom; Eisinga, Rob; Breitling, Rainer

    2014-11-21

    The rank product method is a powerful statistical technique for identifying differentially expressed molecules in replicated experiments. A critical issue in molecule selection is accurate calculation of the p-value of the rank product statistic to adequately address multiple testing. Both exact calculation and permutation and gamma approximations have been proposed to determine molecule-level significance. These current approaches have serious drawbacks as they are either computationally burdensome or provide inaccurate estimates in the tail of the p-value distribution. We derive strict lower and upper bounds to the exact p-value along with an accurate approximation that can be used to assess the significance of the rank product statistic in a computationally fast manner. The bounds and the proposed approximation are shown to provide far better accuracy over existing approximate methods in determining tail probabilities, with the slightly conservative upper bound protecting against false positives. We illustrate the proposed method in the context of a recently published analysis on transcriptomic profiling performed in blood. We provide a method to determine upper bounds and accurate approximate p-values of the rank product statistic. The proposed algorithm provides an order of magnitude increase in throughput as compared with current approaches and offers the opportunity to explore new application domains with even larger multiple testing issue. The R code is published in one of the Additional files and is available at http://www.ru.nl/publish/pages/726696/rankprodbounds.zip .

  2. An unusual methylene aziridine refined in P2(1)/c and the nonstandard setting P2(1)/n.

    Science.gov (United States)

    Feast, George C; Haestier, James; Page, Lee W; Robertson, Jeremy; Thompson, Amber L; Watkin, David J

    2009-12-01

    The unusual methylene aziridine 6-tert-butyl-3-oxa-2-thia-1-azabicyclo[5.1.0]oct-6-ene 2,2-dioxide, C(9)H(15)NO(3)S, was found to crystallize with two molecules in the asymmetric unit. The structure was solved in both the approximately orthogonal and the oblique settings of space group No. 14, viz. P2(1)/n and P2(1)/c, respectively. A comparison of these results clearly displayed an increase in the correlation between coordinates in the ac plane for the oblique cell. The increase in the corresponding covariances makes a significant contribution to the standard uncertainties of derived parameters, e.g. bond lengths. Since there is yet no CIF definition for the full variance-covariance matrix, there are clear advantages to reporting the structure in the nonstandard space-group setting.

  3. Solution of two-dimensional equations of neutron transport in 4P0-approximation of spherical harmonics method

    International Nuclear Information System (INIS)

    Polivanskij, V.P.

    1989-01-01

    The method to solve two-dimensional equations of neutron transport using 4P 0 -approximation is presented. Previously such approach was efficiently used for the solution of one-dimensional problems. New an attempt is made to apply the approach to solution of two-dimensional problems. Algorithm of the solution is given, as well as results of test neutron-physical calculations. A considerable as compared with diffusion approximation is shown. 11 refs

  4. Comparative analysis between P1 and B1 equations for neutron moderation; Analise comparativa entre os metodos de obtencao e das solucoes das equacoes P1 e B1 para moderacao de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Aquilino Senra; Silva, Fernando Carvalho da; Cardoso, Carlos Eduardo Santos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    2000-07-01

    In order to calculate the neutron flux in nuclear reactors, B1 or P1 equations are solved by numerical methods for several groups of energy. The neutron fluxes obtained from the solutions of the B1 and P1 equations are similar when they are applied to large nuclear power reactors. However, an important difference between the two fluxes is that the system of P1 equations uses one more approximation than the B1 system and then, its flux is less precise. The present work shows the relations between both equations and analyzes for what conditions the two equations systems are equivalent. Furthermore, this equations are numerically solved in 54 groups of energy for a quadrangular arrange. (author)

  5. Weighted approximation with varying weight

    CERN Document Server

    Totik, Vilmos

    1994-01-01

    A new construction is given for approximating a logarithmic potential by a discrete one. This yields a new approach to approximation with weighted polynomials of the form w"n"(" "= uppercase)P"n"(" "= uppercase). The new technique settles several open problems, and it leads to a simple proof for the strong asymptotics on some L p(uppercase) extremal problems on the real line with exponential weights, which, for the case p=2, are equivalent to power- type asymptotics for the leading coefficients of the corresponding orthogonal polynomials. The method is also modified toyield (in a sense) uniformly good approximation on the whole support. This allows one to deduce strong asymptotics in some L p(uppercase) extremal problems with varying weights. Applications are given, relating to fast decreasing polynomials, asymptotic behavior of orthogonal polynomials and multipoint Pade approximation. The approach is potential-theoretic, but the text is self-contained.

  6. A 1.375-approximation algorithm for sorting by transpositions.

    Science.gov (United States)

    Elias, Isaac; Hartman, Tzvika

    2006-01-01

    Sorting permutations by transpositions is an important problem in genome rearrangements. A transposition is a rearrangement operation in which a segment is cut out of the permutation and pasted in a different location. The complexity of this problem is still open and it has been a 10-year-old open problem to improve the best known 1.5-approximation algorithm. In this paper, we provide a 1.375-approximation algorithm for sorting by transpositions. The algorithm is based on a new upper bound on the diameter of 3-permutations. In addition, we present some new results regarding the transposition diameter: we improve the lower bound for the transposition diameter of the symmetric group and determine the exact transposition diameter of simple permutations.

  7. Band gap calculations of the semiconductor BNxP1−x using modified Becke–Johnson approximation

    International Nuclear Information System (INIS)

    Benkraouda, M.; Amrane, N.

    2013-01-01

    Highlights: ► The Modified Becke–Johnson scheme gives a very accurate band gap. ► We have shown the invalidity of Vegard’s linear rule for BN x P 1−x . ► The band gap changes with alloy concentration are important in band gap engineering. - Abstract: In this work, the electronic properties of BN, BP and BN x P 1−x compounds have been investigated by means of first-principles density-functional total-energy calculation using the all-electron full potential linear augmented plane-wave method (FP-LAPW). The (FP-LAPW) method was used within the density functional theory (DFT) along with the Engel–Vosko and Becke–Johnson exchange correlation potential. The energy bands along high symmetry directions, the density of states and bowing distributions are calculated. The results have been discussed in terms of previously existing experimental and theoretical data, and comparisons with similar compounds have been made. Analysis of band structure suggests direct and pseudo-direct band gaps for both compounds.

  8. The yields of 1P and 1D resonances in the He(e,2e)He+ reaction

    International Nuclear Information System (INIS)

    Lhagva, O.; Badamdamdin, R.; Strakhova, S.I.; Hehnmedeh, L.

    1991-01-01

    In the first Born approximation the dependence of the yields of the 1 P and 1 D resonances in the He(e,2e)He + reaction on the momentum transfer in the recoil peak region at incident energies E 0 =1000 eV is studied. It is shown that in a certain range of the ejection angle and for the large momentum transfer the yield of the 1 D resonance dominates over the 1 P resonance one. 12 refs.; 4 figs

  9. Modeling of pseudoacoustic P-waves in orthorhombic media with a low-rank approximation

    KAUST Repository

    Song, Xiaolei

    2013-06-04

    Wavefield extrapolation in pseudoacoustic orthorhombic anisotropic media suffers from wave-mode coupling and stability limitations in the parameter range. We use the dispersion relation for scalar wave propagation in pseudoacoustic orthorhombic media to model acoustic wavefields. The wavenumber-domain application of the Laplacian operator allows us to propagate the P-waves exclusively, without imposing any conditions on the parameter range of stability. It also allows us to avoid dispersion artifacts commonly associated with evaluating the Laplacian operator in space domain using practical finite-difference stencils. To handle the corresponding space-wavenumber mixed-domain operator, we apply the low-rank approximation approach. Considering the number of parameters necessary to describe orthorhombic anisotropy, the low-rank approach yields space-wavenumber decomposition of the extrapolator operator that is dependent on space location regardless of the parameters, a feature necessary for orthorhombic anisotropy. Numerical experiments that the proposed wavefield extrapolator is accurate and practically free of dispersion. Furthermore, there is no coupling of qSv and qP waves because we use the analytical dispersion solution corresponding to the P-wave.

  10. Search for W boson pair production in p bar p collisions at √s=1.8 TeV

    International Nuclear Information System (INIS)

    Abachi, S.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adam, I.; Adams, D.L.; Adams, M.; Ahn, S.; Aihara, H.; Alitti, J.; Alvarez, G.; Alves, G.A.; Amidi, E.; Amos, N.; Anderson, E.W.; Aronson, S.H.; Astur, R.; Avery, R.E.; Baden, A.; Balamurali, V.; Balderston, J.; Baldin, B.; Bantly, J.; Bartlett, J.F.; Bazizi, K.; Bendich, J.; Beri, S.B.; Bertram, I.; Bezzubov, V.A.; Bhat, P.C.; Bhatnagar, V.; Bhattacharjee, M.; Bischoff, A.; Biswas, N.; Blazey, G.; Blessing, S.; Boehnlein, A.; Bojko, N.I.; Borcherding, F.; Borders, J.; Boswell, C.; Brandt, A.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoi, V.S.; Butler, J.M.; Casey, D.; Castilla-Valdez, H.; Chakraborty, D.; Chang, S.; Chekulaev, S.V.; Chen, L.; Chen, W.; Chevalier, L.; Chopra, S.; Choudhary, B.C.; Christenson, J.H.; Chung, M.; Claes, D.; Clark, A.R.; Cobau, W.G.; Cochran, J.; Cooper, W.E.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M.; Cutts, D.; Dahl, O.I.; De, K.; Demarteau, M.; Demina, R.; Denisenko, K.; Denisenko, N.; Denisov, D.; Denisov, S.P.; Dharmaratna, W.; Diehl, H.T.; Diesburg, M.; Di Loreto, G.; Dixon, R.; Draper, P.; Drinkard, J.; Ducros, Y.; Dugad, S.R.; Durston-Johnson, S.; Edmunds, D.; Efimov, A.O.; Ellison, J.; Elvira, V.D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O.V.; Evdokimov, V.N.; Fahey, S.; Fahland, T.; Fatyga, M.; Fatyga, M.K.; Featherly, J.; Feher, S.; Fein, D.; Ferbel, T.; Finocchiaro, G.; Fisk, H.E.; Fisyak, Y.; Flattum, E.; Forden, G.E.; Fortner, M.; Frame, K.C.; Franzini, P.; Fredriksen, S.; Fuess, S.; Galjaev, A.N.; Gallas, E.; Gao, C.S.; Gao, S.; Geld, T.L.; Genik, R.J. II; Genser, K.; Gerber, C.E.; Gibbard, B.; Glebov, V.; Glenn, S.; Gobbi, B.; Goforth, M.; Goldschmidt, A.; Gomez, B.; Goncharov, P.I.; Gordon, H.; Goss, L.T.; Graf, N.; Grannis, P.D.; Green, D.R.; Green, J.; Greenlee, H.; Griffin, G.; Grossman, N.; Grudberg, P.; Gruenendahl, S.; Guida, J.A.; Guida, J.M.; Guryn, W.; Gurzhiev, S.N.; Gutnikov, Y.E.; Hadley, N.J.; Haggerty, H.; Hagopian, S.

    1995-01-01

    The results of a search for W boson pair production in p bar p collisions at √s=1.8 TeV with subsequent decay to dilepton (eμ,ee, and μμ) channels are presented. One event is observed with an expected background of 0.56±0.13 events with an integrated luminosity of approximately 14pb -1 . Assuming equal strengths for the WWZ and WWγ gauge boson coupling parameters κ and λ, limits on the CP-conserving anomalous coupling constants are -2.6<Δκ<2.8 and -2.1<λ<2.1 at the 95% confidence level

  11. Search for W boson pair production in p bar p collisions at √s = 1.8 TeV

    International Nuclear Information System (INIS)

    Abachi, S.

    1995-01-01

    The results of a search for W boson pair production in p bar p collisions at √s = 1.8 TeV with subsequent decay to dilepton (eμ, ee, and μμ) channels are presented. One event is observed with an expected background of 0.56 ± 0.13 events with an integrated luminosity of approximately 14 pb -1 . Assuming equal strengths for the WWZ and WWγ gauge boson coupling parameters κ and λ, limits on the CP-conserving anomalous coupling constants are -2.6 < δκ < 2.8 and -2.1 λ < 2.1 at the 95% confidence level

  12. Excitation of the 1P and 3P levels of Mg atom by electron impact

    International Nuclear Information System (INIS)

    Avdonina, N.B.; Amus'ya, M.Ya.

    1983-01-01

    Using a diagram method of the many-body theory in the first order of the perturbation theory for the interaction of incident electron and atom expressions for differential and integral excitation cross sections of 3s → 3p 1 P and 3s → 3p 3 P magnesium have been derived. Calculational results are compared with experimental as well as with calculations made in the approximation of a strong coupling. In a wide range of scattering angles good agreement with cross sections measured experimentally has been obtained. Necessity of the diagram consideration of a higher order of the perturbation theory during the investigation of the scattering processes at small angles is concluded on the basis of the above comparison

  13. Sphingosine-1-phosphate (S1P) displays sustained S1P1 receptor agonism and signaling through S1P lyase-dependent receptor recycling.

    Science.gov (United States)

    Gatfield, John; Monnier, Lucile; Studer, Rolf; Bolli, Martin H; Steiner, Beat; Nayler, Oliver

    2014-07-01

    The sphingosine-1-phosphate (S1P) type 1 receptor (S1P1R) is a novel therapeutic target in lymphocyte-mediated autoimmune diseases. S1P1 receptor desensitization caused by synthetic S1P1 receptor agonists prevents T-lymphocyte egress from secondary lymphoid organs into the circulation. The selective S1P1 receptor agonist ponesimod, which is in development for the treatment of autoimmune diseases, efficiently reduces peripheral lymphocyte counts and displays efficacy in animal models of autoimmune disease. Using ponesimod and the natural ligand S1P, we investigated the molecular mechanisms leading to different signaling, desensitization and trafficking behavior of S1P1 receptors. In recombinant S1P1 receptor-expressing cells, ponesimod and S1P triggered Gαi protein-mediated signaling and β-arrestin recruitment with comparable potency and efficiency, but only ponesimod efficiently induced intracellular receptor accumulation. In human umbilical vein endothelial cells (HUVEC), ponesimod and S1P triggered translocation of the endogenous S1P1 receptor to the Golgi compartment. However, only ponesimod treatment caused efficient surface receptor depletion, receptor accumulation in the Golgi and degradation. Impedance measurements in HUVEC showed that ponesimod induced only short-lived Gαi protein-mediated signaling followed by resistance to further stimulation, whereas S1P induced sustained Gαi protein-mediated signaling without desensitization. Inhibition of S1P lyase activity in HUVEC rendered S1P an efficient S1P1 receptor internalizing compound and abrogated S1P-mediated sustained signaling. This suggests that S1P lyase - by facilitating S1P1 receptor recycling - is essential for S1P-mediated sustained signaling, and that synthetic agonists are functional antagonists because they are not S1P lyase substrates. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Blocking S1P interaction with S1P1 receptor by a novel competitive S1P1-selective antagonist inhibits angiogenesis

    International Nuclear Information System (INIS)

    Fujii, Yasuyuki; Ueda, Yasuji; Ohtake, Hidenori; Ono, Naoya; Takayama, Tetsuo; Nakazawa, Kiyoshi; Igarashi, Yasuyuki; Goitsuka, Ryo

    2012-01-01

    Highlights: ► The effect of a newly developed S1P 1 -selective antagonist on angiogenic responses. ► S1P 1 is a critical component of VEGF-related angiogenic responses. ► S1P 1 -selective antagonist showed in vitro activity to inhibit angiogenesis. ► S1P 1 -selective antagonist showed in vivo activity to inhibit angiogenesis. ► The efficacy of S1P 1 -selective antagonist for anti-cancer therapies. -- Abstract: Sphingosine 1-phosphate receptor type 1 (S1P 1 ) was shown to be essential for vascular maturation during embryonic development and it has been demonstrated that substantial crosstalk exists between S1P 1 and other pro-angiogenic growth factors, such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor. We developed a novel S1P 1 -selective antagonist, TASP0277308, which is structurally unrelated to S1P as well as previously described S1P 1 antagonists. TASP0277308 inhibited S1P- as well as VEGF-induced cellular responses, including migration and proliferation of human umbilical vein endothelial cells. Furthermore, TASP0277308 effectively blocked a VEGF-induced tube formation in vitro and significantly suppressed tumor cell-induced angiogenesis in vivo. These findings revealed that S1P 1 is a critical component of VEGF-related angiogenic responses and also provide evidence for the efficacy of TASP0277308 for anti-cancer therapies.

  15. Alignment creation in atomic ensembles by elastic electron scattering; the case of 138Ba(...6s6p 1P1) atoms

    International Nuclear Information System (INIS)

    Trajmar, S.; Kanik, I.; LeClair, L.R.; Khakoo, M.A.; Bray, I.; Fursa, D.; Csanak, G.

    1998-01-01

    We describe some of our results from a joint experimental and theoretical program concerning elastic electron scattering by 138 Ba(...6s6p 1 P 1 ) atoms. From the experimental results, we derived various scattering parameters and magnetic sublevel specific differential elastic scattering cross sections at impact energy (E 0 ) of 20.0 eV and at scattering angles (θ) of 10deg, 15deg, and 20deg. The same parameters and cross sections were calculated by the convergent close coupling (CCC) approximation and compared to the experimental results. An excellent agreement, found for the two sets of data, gave us confidence in the CCC method and allowed us to extend the angular and energy ranges for the purpose of generating integral elastic scattering cross sections needed for the deduction of the alignment creation cross sections. (J.P.N.)

  16. Universality for 1d Random Band Matrices: Sigma-Model Approximation

    Science.gov (United States)

    Shcherbina, Mariya; Shcherbina, Tatyana

    2018-02-01

    The paper continues the development of the rigorous supersymmetric transfer matrix approach to the random band matrices started in (J Stat Phys 164:1233-1260, 2016; Commun Math Phys 351:1009-1044, 2017). We consider random Hermitian block band matrices consisting of W× W random Gaussian blocks (parametrized by j,k \\in Λ =[1,n]^d\\cap Z^d ) with a fixed entry's variance J_{jk}=δ _{j,k}W^{-1}+β Δ _{j,k}W^{-2} , β >0 in each block. Taking the limit W→ ∞ with fixed n and β , we derive the sigma-model approximation of the second correlation function similar to Efetov's one. Then, considering the limit β , n→ ∞, we prove that in the dimension d=1 the behaviour of the sigma-model approximation in the bulk of the spectrum, as β ≫ n , is determined by the classical Wigner-Dyson statistics.

  17. HQET at order 1/m. Pt. 1. Non-perturbative parameters in the quenched approximation

    International Nuclear Information System (INIS)

    Blossier, Benoit; Della Morte, Michele; Garron, Nicolas; Edinburgh Univ.; Sommer, Rainer

    2010-01-01

    We determine non-perturbatively the parameters of the lattice HQET Lagrangian and those of heavy-light axial-vector and vector currents in the quenched approximation. The HQET expansion includes terms of order 1/m b . Our results allow to compute, for example, the heavy-light spectrum and B-meson decay constants in the static approximation and to order 1/m b in HQET. The determination of the parameters is separated into universal and non-universal parts. The universal results can be used to determine the parameters for various discretizations. The computation reported in this paper uses the plaquette gauge action and the ''HYP1/2'' action for the b-quark described by HQET. The parameters of the currents also depend on the light-quark action, for which we choose non-perturbatively O(a)-improved Wilson fermions. (orig.)

  18. HQET at order 1/m. Pt. 1. Non-perturbative parameters in the quenched approximation

    Energy Technology Data Exchange (ETDEWEB)

    Blossier, Benoit [Paris XI Univ., 91 - Orsay (France). Lab. de Physique Theorique; Della Morte, Michele [Mainz Univ. (Germany). Inst. fuer Kernphysik; Garron, Nicolas [Universidad Autonoma de Madrid (Spain). Dept. Fisica Teorica y Inst. de Fisica Teorica UAM/CSIC; Edinburgh Univ. (United Kingdom). School of Physics and Astronomy - SUPA; Sommer, Rainer [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2010-01-15

    We determine non-perturbatively the parameters of the lattice HQET Lagrangian and those of heavy-light axial-vector and vector currents in the quenched approximation. The HQET expansion includes terms of order 1/m{sub b}. Our results allow to compute, for example, the heavy-light spectrum and B-meson decay constants in the static approximation and to order 1/m{sub b} in HQET. The determination of the parameters is separated into universal and non-universal parts. The universal results can be used to determine the parameters for various discretizations. The computation reported in this paper uses the plaquette gauge action and the ''HYP1/2'' action for the b-quark described by HQET. The parameters of the currents also depend on the light-quark action, for which we choose non-perturbatively O(a)-improved Wilson fermions. (orig.)

  19. Color Coherent Radiation in Multi - Jet Events from $p\\overline{p}$ Collisions at $\\sqrt{s}$ = 1.8-TeV

    Energy Technology Data Exchange (ETDEWEB)

    Cullen-Vidal, David Edward [Brown U.

    1997-01-01

    Results from a study of color coherence phenomena in multi-jet events produced by $p\\overline{p}$ collisions are presented. Approximately 13 $pb^{-1}$ of data were collected by the D0 detector during the 1992-1993 run of the Fermilab Tevatron $p\\overline{p}$ collider at a center of mass energy of $\\sqrt{s}$ = 1.8 TeV. Demonstration of initial-to-final state color interference effects is done by measuring spatial correlations between the softer third jet and the second leading-$E_{\\tau}$ jet in the events. The data are compared to several Monte Carlo simulations with different color coherence implementations and to the predictions of a Next-to-Leading Order parton level calculation.

  20. An Oblivious O(1)-Approximation for Single Source Buy-at-Bulk

    KAUST Repository

    Goel, Ashish

    2009-10-01

    We consider the single-source (or single-sink) buy-at-bulk problem with an unknown concave cost function. We want to route a set of demands along a graph to or from a designated root node, and the cost of routing x units of flow along an edge is proportional to some concave, non-decreasing function f such that f(0) = 0. We present a polynomial time algorithm that finds a distribution over trees such that the expected cost of a tree for any f is within an O(1)-factor of the optimum cost for that f. The previous best simultaneous approximation for this problem, even ignoring computation time, was O(log |D|), where D is the multi-set of demand nodes. We design a simple algorithmic framework using the ellipsoid method that finds an O(1)-approximation if one exists, and then construct a separation oracle using a novel adaptation of the Guha, Meyerson, and Munagala [10] algorithm for the single-sink buy-at-bulk problem that proves an O(1) approximation is possible for all f. The number of trees in the support of the distribution constructed by our algorithm is at most 1 + log |D|. © 2009 IEEE.

  1. Conditional Density Approximations with Mixtures of Polynomials

    DEFF Research Database (Denmark)

    Varando, Gherardo; López-Cruz, Pedro L.; Nielsen, Thomas Dyhre

    2015-01-01

    Mixtures of polynomials (MoPs) are a non-parametric density estimation technique especially designed for hybrid Bayesian networks with continuous and discrete variables. Algorithms to learn one- and multi-dimensional (marginal) MoPs from data have recently been proposed. In this paper we introduce...... two methods for learning MoP approximations of conditional densities from data. Both approaches are based on learning MoP approximations of the joint density and the marginal density of the conditioning variables, but they differ as to how the MoP approximation of the quotient of the two densities...

  2. Approximation of the thermometric characteristics of n- and p-GaAs thermodiodes in the 4.2-300 K temperature range and p-GaAs resistance thermometers in the 4.2-100 K temperature range

    International Nuclear Information System (INIS)

    Logvinenko, S.P.; Derbysheva, S.L.

    1978-01-01

    The investigation results are reported of various methods for approximating the calibration characteristics of technical resistance thermometers made from p-GaAs and of thermodiodes from n- p-GaAs. The following methods may by used for approximating thermometric characteristics and obtaining calibration tables: method of approximating function describing a physical model (P); method of power polynoms (PP); and the spline method (S). Studies of thermometric characteristics have been achieved in the 4.2-300 K temperature range for thermodiodes, and at 4.2-100 K for thermoresistances. The obtained data show that the use of the S and PP methods for describing monotonous thermometric characteristics of thermodiodes and thermoresistances is equivalent and leads to satisfactory results. Method S affords the best results for describing thermometric characteristics with specific features. The error in approximating thermometric characteristics by method S does not exceed 0.01 K

  3. Approximate critical surface of the bond-mixed square-lattice Ising model

    International Nuclear Information System (INIS)

    Levy, S.V.F.; Tsallis, C.; Curado, E.M.F.

    1979-09-01

    The critical surface of the quenched bond-mixed square-lattice spin-1/2 first-neighbour-interaction ferromagnetic Ising model (with exchange interactions J 1 and J 2 ) has been investigated. Through renormalization group and heuristical procedures, a very accurate (error inferior to 3x10 -4 in the variables t sub(i) = th (J sub(i)/k sub(b)T)) approximate numerical proposal for all points of this surface is presented. This proposal simultaneously satisfies all the available exact results concerning the surface, namely P sub(c) = 1/2, t sub(c) = √2 - 1, both limiting slopes in these points, and t 2 = (1-t 1 )/(1+t 1 ) for p = 1/2. Furthemore an analytic approximation (namely (1 - p) 1n(1 + t 1 ) + p 1n(1 + t 2 ) =(1/2)1n 2) is also proposed. In what concerns the available exact results, it only fails in reproducing one of the two limiting slopes, where there is an error of 1% in the derivative: these facts result in an estimated error less than 10 -3 (in the t-variables) for any points in the surface. (Author) [pt

  4. Blocking S1P interaction with S1P{sub 1} receptor by a novel competitive S1P{sub 1}-selective antagonist inhibits angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Yasuyuki, E-mail: y.fujii@po.rd.taisho.co.jp [Department of Molecular Function and Pharmacology Laboratories, Taisho Pharmaceutical Co. Ltd., 1-403 Saitama, Saitama 331-9530 (Japan); Ueda, Yasuji; Ohtake, Hidenori; Ono, Naoya; Takayama, Tetsuo; Nakazawa, Kiyoshi [Department of Molecular Function and Pharmacology Laboratories, Taisho Pharmaceutical Co. Ltd., 1-403 Saitama, Saitama 331-9530 (Japan); Igarashi, Yasuyuki [Laboratory of Biomembrane and Biofunctional Chemistry, Hokkaido University, Sapporo, Hokkaido 060-0812 (Japan); Goitsuka, Ryo [Division of Development and Aging, Research Institute for Biological Sciences, Tokyo University of Science, Noda, Chiba 278-0022 (Japan)

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer The effect of a newly developed S1P{sub 1}-selective antagonist on angiogenic responses. Black-Right-Pointing-Pointer S1P{sub 1} is a critical component of VEGF-related angiogenic responses. Black-Right-Pointing-Pointer S1P{sub 1}-selective antagonist showed in vitro activity to inhibit angiogenesis. Black-Right-Pointing-Pointer S1P{sub 1}-selective antagonist showed in vivo activity to inhibit angiogenesis. Black-Right-Pointing-Pointer The efficacy of S1P{sub 1}-selective antagonist for anti-cancer therapies. -- Abstract: Sphingosine 1-phosphate receptor type 1 (S1P{sub 1}) was shown to be essential for vascular maturation during embryonic development and it has been demonstrated that substantial crosstalk exists between S1P{sub 1} and other pro-angiogenic growth factors, such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor. We developed a novel S1P{sub 1}-selective antagonist, TASP0277308, which is structurally unrelated to S1P as well as previously described S1P{sub 1} antagonists. TASP0277308 inhibited S1P- as well as VEGF-induced cellular responses, including migration and proliferation of human umbilical vein endothelial cells. Furthermore, TASP0277308 effectively blocked a VEGF-induced tube formation in vitro and significantly suppressed tumor cell-induced angiogenesis in vivo. These findings revealed that S1P{sub 1} is a critical component of VEGF-related angiogenic responses and also provide evidence for the efficacy of TASP0277308 for anti-cancer therapies.

  5. A structural, magnetic and Moessbauer spectral study of the magnetocaloric Mn1.1Fe0.9P1-xGex compounds

    International Nuclear Information System (INIS)

    Sougrati, Moulay T; Hermann, Raphael P; Grandjean, Fernande; Long, Gary J; Brueck, E; Tegus, O; Trung, N T; Buschow, K H J

    2008-01-01

    The structural, magnetic and Moessbauer spectral properties of the magnetocaloric Mn 1.1 Fe 0.9 P 1-x Ge x compounds, with 0.19 1.1 Fe 0.9 P 0.74 Ge 0.26 . The temperature dependence of the magnetization reveals a ferromagnetic to paramagnetic transition with a Curie temperature between approximately 250 and 330 K and hysteresis width of 10 to 4 K, for 0.19 1.1 Fe 0.9 P 0.78 Ge 0.22 shows the largest isothermal entropy change of approximately 10 J/(kgKT) at 290 K. The Moessbauer spectra have been analysed with a binomial distribution of hyperfine fields correlated with a change in isomer shift and quadrupole shift, a distribution that results from the distribution of phosphorus and germanium among the near neighbours of the iron. The coexistence of paramagnetic and magnetically ordered phases in ranges of temperature of up to 50 K around the Curie temperature is observed in the Moessbauer spectra and is associated with the first-order character of the ferromagnetic to paramagnetic transition. The temperature dependence of the weighted average hyperfine field is well fitted within the magnetostrictive model of Bean and Rodbell. Good fits of the Moessbauer spectra could only be achieved by introducing a difference between the isomer shifts in the paramagnetic and ferromagnetic phases, a difference that is related to the magnetostriction and electronic structure change.

  6. Multi-species interactions impact the accumulation of weathered 2,2-bis (p-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE) from soil

    International Nuclear Information System (INIS)

    Kelsey, Jason W.; White, Jason C.

    2005-01-01

    The impact of interactions between the earthworms Eisenia foetida and Lumbricus terrestris and the plants Cucurbita pepo and Cucurbita maxima on the uptake of weathered p,p'-DDE from soil was determined. Although some combinations of earthworm and plant species caused significant changes in the p,p'-DDE burden in both organisms, the effects were species specific. Contaminant bioconcentration in C. pepo was increased slightly by E. foetida and by 3-fold when the plant was grown with L. terrestris. E. foetida had no effect on the contaminant BCF by C. maxima, but L. terrestris caused a 2-fold reduction in p,p'-DDE uptake by the plant. Contaminant levels in E. foetida and L. terrestris were unaffected by C. pepo. When grown with C. maxima, the concentration of p,p'-DDE decreased by approximately 4-fold and 7-fold in E. foetida and L. terrestris, respectively. The data suggest that the prediction of contaminant bioavailability should consider interactions among species. - Interactions between earthworms and plants affect both the phytoextraction and bioaccumulation of p,p'-DDE in soil

  7. Various pfcrt and pfmdr1 Genotypes of Plasmodium falciparum Cocirculate with P. malariae, P. ovale spp., and P. vivax in Northern Angola

    Science.gov (United States)

    Fançony, Cláudia; Gamboa, Dina; Sebastião, Yuri; Hallett, Rachel; Sutherland, Colin; Sousa-Figueiredo, José Carlos

    2012-01-01

    Artemisinin-based combination therapy for malaria has become widely available across Africa. Populations of Plasmodium falciparum that were previously dominated by chloroquine (CQ)-resistant genotypes are now under different drug selection pressures. P. malariae, P. ovale curtisi, and P. ovale wallikeri are sympatric with P. falciparum across the continent and are frequently present as coinfections. The prevalence of human Plasmodium species was determined by PCR using DNA from blood spots collected during a cross-sectional survey in northern Angola. P. falciparum was genotyped at resistance-associated loci in pfcrt and pfmdr1 by real-time PCR or by direct sequencing of amplicons. Of the 3,316 samples collected, 541 (16.3%) contained Plasmodium species infections; 477 (88.2%) of these were P. falciparum alone, 6.5% were P. falciparum and P. malariae together, and 1.1% were P. vivax alone. The majority of the remainder (3.7%) harbored P. ovale curtisi or P. ovale wallikeri alone or in combination with other species. Of 430 P. falciparum isolates genotyped for pfcrt, 61.6% carried the wild-type allele CVMNK at codons 72 to 76, either alone or in combination with the resistant allele CVIET. No other pfcrt allele was found. Wild-type alleles dominated at codons 86, 184, 1034, 1042, and 1246 of the pfmdr1 locus among the sequenced isolates. In contrast to previous studies, P. falciparum in the study area comprises an approximately equal mix of genotypes associated with CQ sensitivity and with CQ resistance, suggesting either lower drug pressure due to poor access to treatment in rural areas or a rapid impact of the policy change away from the use of standard monotherapies. PMID:22850519

  8. Co-expression of human cytochrome P4501A1 (CYP1A1) variants and human NADPH-cytochrome P450 reductase in the baculovirus/insect cell system.

    Science.gov (United States)

    Schwarz, D; Kisselev, P; Honeck, H; Cascorbi, I; Schunck, W H; Roots, I

    2001-06-01

    1. Three human cytochrome P4501A1 (CYP1A1) variants, wild-type (CYP1A1.1), CYP1A1.2 (1462V) and CYP1A1.4 (T461N), were co-expressed with human NADPH-P450 reductase (OR) in Spodoptera frugiperda (Sf9) insect cells by baculovirus co-infection to elaborate a suitable system for studying the role of CYPA1 polymorphism in the metabolism of exogenous and endogenous substrates. 2. A wide range of conditions was examined to optimize co-expression with regard to such parameters as relative multiplicity of infection (MOI), time of harvest, haem precursor supplementation and post-translational stabilization. tinder optimized conditions, almost identical expression levels and molar OR/CYP1A1 ratios (20:1) were attained for all CYP1A1 variants. 3. Microsomes isolated from co-infected cells demonstrated ethoxyresorufin deethlylase activities (nmol/min(-1) nmol(-1) CYP1A1) of 16.0 (CYP1A1.1), 20.5 (CYP1A1.2) and 22.5 (CYP1A1.4). Pentoxyresorufin was dealkylated approximately 10-20 times slower with all enzyme variants. 4. All three CYP1A1 variants were active in metabolizing the precarcinogen benzo[a]pyrene (B[a]P), with wild-type enzyme showing the highest activity, followed by CYP1A1.4 (60%) and CYP1A1.2 (40%). Each variant produced all major metabolites including B[a]P-7,8-dihydrodiol, the precursor of the ultimate carcinogenic species. 5. These studies demonstrate that the baculovirus-mediated co-expression-by-co-infection approach all CYP1A1 variants yields functionally active enzyme systems with similar molar OR/CYP1A1 ratios, thus providing suitable preconditions to examine the metabolism of and environmental chemicals by the different CY1A1 variants.

  9. Limit on the $B^0_s \\bar{B}^0_s$ meson oscillation frequency from $p\\bar{p}$ collision data at $\\sqrt{s} = 1.8$-TeV

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Hong-quan [Brandeis Univ., Waltham, MA (United States)

    2003-01-01

    This thesis presents a limit on the B$0\\atop{s}$$\\bar{B}$$0\\atop{s}$ oscillation frequency from p$\\bar{p}$ collision data at √s = 1.8 TeV at CDF. The data sample used is the inclusive electron and muon trigger data of approximately 90 pb-1 collected during the 1993-95 run.

  10. Approximate Coulomb effects in the three-body scattering problem

    International Nuclear Information System (INIS)

    Haftel, M.I.; Zankel, H.

    1981-01-01

    From the momentum space Faddeev equations we derive approximate expressions which describe the Coulomb-nuclear interference in the three-body elastic scattering, rearrangement, and breakup problems and apply the formalism to p-d elastic scattering. The approximations treat the Coulomb interference as mainly a two-body effect, but we allow for the charge distribution of the deuteron in the p-d calculations. Real and imaginary parts of the Coulomb correction to the elastic scattering phase shifts are described in terms of on-shell quantities only. In the case of pure Coulomb breakup we recover the distorted-wave Born approximation result. Comparing the derived approximation with the full Faddeev p-d elastic scattering calculation, which includes the Coulomb force, we obtain good qualitative agreement in S and P waves, but disagreement in repulsive higher partial waves. The on-shell approximation investigated is found to be superior to other current approximations. The calculated differential cross sections at 10 MeV raise the question of whether there is a significant Coulomb-nuclear interference at backward angles

  11. On some applications of diophantine approximations.

    Science.gov (United States)

    Chudnovsky, G V

    1984-03-01

    Siegel's results [Siegel, C. L. (1929) Abh. Preuss. Akad. Wiss. Phys.-Math. Kl. 1] on the transcendence and algebraic independence of values of E-functions are refined to obtain the best possible bound for the measures of irrationality and linear independence of values of arbitrary E-functions at rational points. Our results show that values of E-functions at rational points have measures of diophantine approximations typical to "almost all" numbers. In particular, any such number has the "2 + epsilon" exponent of irrationality: Theta - p/q > q(-2-epsilon) for relatively prime rational integers p,q, with q >/= q(0) (Theta, epsilon). These results answer some problems posed by Lang. The methods used here are based on the introduction of graded Padé approximations to systems of functions satisfying linear differential equations with rational function coefficients. The constructions and proofs of this paper were used in the functional (nonarithmetic case) in a previous paper [Chudnovsky, D. V. & Chudnovsky, G. V. (1983) Proc. Natl. Acad. Sci. USA 80, 5158-5162].

  12. Efficient parallel implementations of approximation algorithms for guarding 1.5D terrains

    Directory of Open Access Journals (Sweden)

    Goran Martinović

    2015-03-01

    Full Text Available In the 1.5D terrain guarding problem, an x-monotone polygonal line is dened by k vertices and a G set of terrain points, i.e. guards, and a N set of terrain points which guards are to observe (guard. This involves a weighted version of the guarding problem where guards G have weights. The goal is to determine a minimum weight subset of G to cover all the points in N, including a version where points from N have demands. Furthermore, another goal is to determine the smallest subset of G, such that every point in N is observed by the required number of guards. Both problems are NP-hard and have a factor 5 approximation [3, 4]. This paper will show that if the (1+ϵ-approximate solver for the corresponding linear program is a computer, for any ϵ > 0, an extra 1+ϵ factor will appear in the final approximation factor for both problems. A comparison will be carried out the parallel implementation based on GPU and CPU threads with the Gurobi solver, leading to the conclusion that the respective algorithm outperforms the Gurobi solver on large and dense inputs typically by one order of magnitude.

  13. Arithmetically Cohen-Macaulay sets of points in P^1 x P^1

    CERN Document Server

    Guardo, Elena

    2015-01-01

    This brief presents a solution to the interpolation problem for arithmetically Cohen-Macaulay (ACM) sets of points in the multiprojective space P^1 x P^1.  It collects the various current threads in the literature on this topic with the aim of providing a self-contained, unified introduction while also advancing some new ideas.  The relevant constructions related to multiprojective spaces are reviewed first, followed by the basic properties of points in P^1 x P^1, the bigraded Hilbert function, and ACM sets of points.  The authors then show how, using a combinatorial description of ACM points in P^1 x P^1, the bigraded Hilbert function can be computed and, as a result, solve the interpolation problem.  In subsequent chapters, they consider fat points and double points in P^1 x P^1 and demonstrate how to use their results to answer questions and problems of interest in commutative algebra.  Throughout the book, chapters end with a brief historical overview, citations of related results, and, where relevan...

  14. Electron-impact coherence parameters for 41 P 1 excitation of zinc

    Science.gov (United States)

    Piwiński, Mariusz; Kłosowski, Łukasz; Chwirot, Stanisław; Fursa, Dmitry V.; Bray, Igor; Das, Tapasi; Srivastava, Rajesh

    2018-04-01

    We present electron-impact coherence parameters (EICP) for electron-impact excitation of 41 P 1 state of zinc atoms for collision energies 40 eV and 60 eV. The experimental results are presented together with convergent close-coupling and relativistic distorted-wave approximation theoretical predictions. The results are compared and discussed with EICP data for collision energies 80 eV and 100 eV.

  15. Study of TiO2(1 1 0)-p(1x1), p(1x2) and p(1x3) surface structures by impact collision ion scattering spectroscopy (ICISS)

    International Nuclear Information System (INIS)

    Asari, E.; Souda, R.

    2000-01-01

    The surface structure of TiO 2 (1 1 0)-p(1x1), p(1x2) and p(1x3) were studied using impact collision ion scattering spectroscopy (ICISS). We found that (i) the height of bridging oxygen for the p(1x1) is comparative to that of bulk structure, (ii) the p(1x2) surface has the added Ti 2 O 3 unit rows proposed by Onishi et al. and also the oxygen atoms rows between Ti 2 O 3 unit rows and (iii) the p(1x3) surface is constructed with the same added Ti 2 O 3 unit rows as that in the p(1x2) surface, but the bridging oxygen rows exist between the Ti 2 O 3 unit rows

  16. Hyperoxia-induced p47phox activation and ROS generation is mediated through S1P transporter Spns2, and S1P/S1P1&2 signaling axis in lung endothelium.

    Science.gov (United States)

    Harijith, Anantha; Pendyala, Srikanth; Ebenezer, David L; Ha, Alison W; Fu, Panfeng; Wang, Yue-Ting; Ma, Ke; Toth, Peter T; Berdyshev, Evgeny V; Kanteti, Prasad; Natarajan, Viswanathan

    2016-08-01

    Hyperoxia-induced lung injury adversely affects ICU patients and neonates on ventilator assisted breathing. The underlying culprit appears to be reactive oxygen species (ROS)-induced lung damage. The major contributor of hyperoxia-induced ROS is activation of the multiprotein enzyme complex NADPH oxidase. Sphingosine-1-phosphate (S1P) signaling is known to be involved in hyperoxia-mediated ROS generation; however, the mechanism(s) of S1P-induced NADPH oxidase activation is unclear. Here, we investigated various steps in the S1P signaling pathway mediating ROS production in response to hyperoxia in lung endothelium. Of the two closely related sphingosine kinases (SphKs)1 and 2, which synthesize S1P from sphingosine, only Sphk1(-/-) mice conferred protection against hyperoxia-induced lung injury. S1P is metabolized predominantly by S1P lyase and partial deletion of Sgpl1 (Sgpl1(+/-)) in mice accentuated lung injury. Hyperoxia stimulated S1P accumulation in human lung microvascular endothelial cells (HLMVECs), and downregulation of S1P transporter spinster homolog 2 (Spns2) or S1P receptors S1P1&2, but not S1P3, using specific siRNA attenuated hyperoxia-induced p47(phox) translocation to cell periphery and ROS generation in HLMVECs. These results suggest a role for Spns2 and S1P1&2 in hyperoxia-mediated ROS generation. In addition, p47(phox) (phox:phagocyte oxidase) activation and ROS generation was also reduced by PF543, a specific SphK1 inhibitor in HLMVECs. Our data indicate a novel role for Spns2 and S1P1&2 in the activation of p47(phox) and production of ROS involved in hyperoxia-mediated lung injury in neonatal and adult mice. Copyright © 2016 the American Physiological Society.

  17. Familial partial duplication (1)(p21p31)

    Energy Technology Data Exchange (ETDEWEB)

    Hoechstetter, L.; Soukup, S.; Schorry, E.K. [Children`s Hospital Research Foundation, Cincinnati, OH (United States)

    1995-11-20

    A partial duplication (1)(p21p31), resulting from a maternal direct insertion (13,1) (q22p21p31), was found in a 30-year-old woman with mental retardation, cleft palate, and multiple minor anomalies. Two other affected and deceased relatives were presumed to have the same chromosome imbalance. Duplication 1p cases are reviewed. 8 refs., 5 figs., 1 tab.

  18. Importance of sequential two-step transfer process in a ΔS = 1 and ΔT = 1 inelastic transition of 14N(p, p')14N reaction

    International Nuclear Information System (INIS)

    Aoki, Y.; Kunori, S.; Nagano, K.; Toba, Y.; Yagi, K.

    1981-01-01

    Differential cross sections and vector analyzing powers for 14 N(p, p') and 14 N(p, d) reactions have been measured at E sub(p) = 21.0 MeV to elucidate the reaction mechanism and the effective interaction for the ΔS = ΔT = 1 transition in 14 N(p, p') 14 N(2.31 MeV) reaction. The data are analyzed in terms of finite-range distorted wave Borm approximation (DWBA) which include direct, knock-on exchange and (p, d)(d, p') two-step processes. Shell model wave functions of Cohen and Kurath are used. The data for the first excited state is reasonably well explained by introducing two-step process. The two-step process explains half of the experimental intensity. Moreover vector analyzing power can hardly be explained without introducing this two-step process. Vector analyzing power of protons leading to the second excited state in 14 N is better explained by introducing macroscopic calculation. The data for 14 N(p, d) 13 N(gs) reaction are well explained by a suitable choice of deuteron optical potential. Knock-on exchange contribution is relatively small. Importance of this two-step process for ΔS = ΔT = 1 transition is discussed up to 40 MeV. (author)

  19. Lattice dynamics and thermophysical properties of h.c.p. Os and Ru from the quasi-harmonic approximation.

    Science.gov (United States)

    Palumbo, Mauro; Dal Corso, Andrea

    2017-10-04

    We report first-principles phonon frequencies and anharmonic thermodynamic properties of h.c.p. Os and Ru calculated within the quasi-harmonic approximation, including Grüneisen parameters, temperature-dependent lattice parameters, thermal expansion, and isobaric heat capacity. We discuss the differences between a full treatment of anisotropy and a simplified approach with a constant [Formula: see text] ratio. The results are systematically compared with the available theoretical and experimental data and an overall satisfactory agreement is obtained.

  20. Diophantine approximation and badly approximable sets

    DEFF Research Database (Denmark)

    Kristensen, S.; Thorn, R.; Velani, S.

    2006-01-01

    . The classical set Bad of `badly approximable' numbers in the theory of Diophantine approximation falls within our framework as do the sets Bad(i,j) of simultaneously badly approximable numbers. Under various natural conditions we prove that the badly approximable subsets of Omega have full Hausdorff dimension...

  1. Specific features of time-dependent Psub(N) approximations in spherical geometry

    International Nuclear Information System (INIS)

    Peltzer, P.; Pucker, N.

    1979-01-01

    Approximations to the time-dependent linear transport equation can result in more serious distortions in the description of the actual physical situation than in the stationary problem. This is demonstrated in detail for the case of a neutron pulse in spherical geometry, treated within a P 1 approximation. One has to pay special attention to the singularity at r = 0 and to the effect of the boundary conditions. Effects similar to those shown here are also to be expected in connection with Psub(N) approximations of higher order. (Auth.)

  2. Energy dependence of isovector and isoscalar 1+ excitations in 28Si(p,p/sup '/) between 200 and 400 MeV

    International Nuclear Information System (INIS)

    Haeusser, O.; Sawafta, R.; Jeppesen, R.G.

    1988-01-01

    Forward-angle cross sections for 1 + , T = 1 and 1 + , T = 0 states in 28 Si excited by the (p,p') reaction have been measured to determine the energy dependence of important pieces of the effective nucleon-nucleus interaction. The isovector spin-transfer transitions depend on energy as expected from distorted-wave impulse approximation calculations based on the dominant V/sub Σ//sub tau/ part of the Franey-Love interaction. The parts of this interaction responsible for exciting the 9.5 MeV isosca- lar spin-flip transition predict a weaker energy dependence than is observed experimentally. The summed Gamow-Teller strength for isovector transitions below 14.5 MeV is found to be (0.89 +- 0.09) times the result of large-scale shell model calculations

  3. Posttranscriptional regulation of the karyogamy gene by Kem1p/Xrn1p exoribonuclease and Rok1p RNA helicase of Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Kim, Jaehee; Jeon, Soonmee; Yang, Yun-Seok; Kim, Jinmi

    2004-01-01

    The major biochemical activities ascribed to Kem1p/Xrn1p of Saccharomyces cerevisiae are 5'-3' exoribonuclease functioning in RNA turnover and a microtubule-binding protein. Mutational analysis has shown that Kem1p/Xrn1p participates in microtubule-related functions such as nuclear fusion (karyogamy) during mating, chromosome transmission, and spindle pole body duplication. Here, evidence is presented that Kem1p plays a specific role in nuclear fusion by affecting, at the posttranscriptional level, the pheromone induction of the karyogamy-specific transcription factor Kar4p and the expression of Rok1p, a putative RNA helicase. We found that Rok1p itself also affects the pheromone induction of Kar4p and thereby participates in nuclear fusion. Analysis of the active-site mutations, xrn1-D206A or D208A, shows that nuclear fusion as well as the Rok1p synthesis do not require the exoribonuclease activity of Kem1p. Our data provide an important insight into the gene-specific regulatory function mediated by the general RNA-modulating enzymes

  4. Approximate furthest neighbor with application to annulus query

    DEFF Research Database (Denmark)

    Pagh, Rasmus; Silvestri, Francesco; Sivertsen, Johan von Tangen

    2016-01-01

    -dimensional Euclidean space. The method builds on the technique of Indyk (SODA 2003), storing random projections to provide sublinear query time for AFN. However, we introduce a different query algorithm, improving on Indyk׳s approximation factor and reducing the running time by a logarithmic factor. We also present......, the query-dependent approach is used for deriving a data structure for the approximate annulus query problem, which is defined as follows: given an input set S and two parameters r>0 and w≥1, construct a data structure that returns for each query point q a point p∈S such that the distance between p and q...

  5. Downregulation of sphingosine 1-phosphate (S1P) receptor 1 by dexamethasone inhibits S1P-induced mesangial cell migration.

    Science.gov (United States)

    Koch, Alexander; Jäger, Manuel; Völzke, Anja; Grammatikos, Georgios; Zu Heringdorf, Dagmar Meyer; Huwiler, Andrea; Pfeilschifter, Josef

    2015-06-01

    Sphingosine 1-phosphate (S1P) is generated by sphingosine kinase (SK)-1 and -2 and acts mainly as an extracellular ligand at five specific receptors, denoted S1P1-5. After activation, S1P receptors regulate important processes in the progression of renal diseases, such as mesangial cell migration and survival. Previously, we showed that dexamethasone enhances SK-1 activity and S1P formation, which protected mesangial cells from stress-induced apoptosis. Here we demonstrate that dexamethasone treatment lowered S1P1 mRNA and protein expression levels in rat mesangial cells. This effect was abolished in the presence of the glucocorticoid receptor antagonist RU-486. In addition, in vivo studies showed that dexamethasone downregulated S1P1 expression in glomeruli isolated from mice treated with dexamethasone (10 mg/kg body weight). Functionally, we identified S1P1 as a key player mediating S1P-induced mesangial cell migration. We show that dexamethasone treatment significantly lowered S1P-induced migration of mesangial cells, which was again reversed in the presence of RU-486. In summary, we suggest that dexamethasone inhibits S1P-induced mesangial cell migration via downregulation of S1P1. Overall, these results demonstrate that dexamethasone has functional important effects on sphingolipid metabolism and action in renal mesangial cells.

  6. Polarization observables of the d-vector p-vector → p-vector d reaction and one-neutron-exchange approximation

    International Nuclear Information System (INIS)

    Kobushkin, A.P.; Syamtomov, A.I.; Perdrisat, C.F.; Punjabi, V.

    1994-01-01

    The polarization observables in the elastic scattering of polarized deuterons on a polarized hydrogen target, with measurement of the recoil proton polarization, are considered. The observables are calculated in the one-neutron exchange approximation, for the special case of backward scattering (Θ c.m = 180 degree). Several new relations between polarization observables of the reaction are derived within the framework of this approximation. (author). 20 refs., 3 figs

  7. Intracellular S1P generation is essential for S1P-induced motility of human lung endothelial cells: role of sphingosine kinase 1 and S1P lyase.

    Directory of Open Access Journals (Sweden)

    Evgeny V Berdyshev

    Full Text Available BACKGROUND: Earlier we have shown that extracellular sphingosine-1-phosphate (S1P induces migration of human pulmonary artery endothelial cells (HPAECs through the activation of S1P(1 receptor, PKCε, and PLD2-PKCζ-Rac1 signaling cascade. As endothelial cells generate intracellular S1P, here we have investigated the role of sphingosine kinases (SphKs and S1P lyase (S1PL, that regulate intracellular S1P accumulation, in HPAEC motility. METHODOLOGY/PRINCIPAL FINDINGS: Inhibition of SphK activity with a SphK inhibitor 2-(p-Hydroxyanilino-4-(p-Chlorophenyl Thiazole or down-regulation of Sphk1, but not SphK2, with siRNA decreased S1P(int, and attenuated S1P(ext or serum-induced motility of HPAECs. On the contrary, inhibition of S1PL with 4-deoxypyridoxine or knockdown of S1PL with siRNA increased S1P(int and potentiated motility of HPAECs to S1P(ext or serum. S1P(ext mediates cell motility through activation of Rac1 and IQGAP1 signal transduction in HPAECs. Silencing of SphK1 by siRNA attenuated Rac1 and IQGAP1 translocation to the cell periphery; however, knockdown of S1PL with siRNA or 4-deoxypyridoxine augmented activated Rac1 and stimulated Rac1 and IQGAP1 translocation to cell periphery. The increased cell motility mediated by down-regulation was S1PL was pertussis toxin sensitive suggesting "inside-out" signaling of intracellularly generated S1P. Although S1P did not accumulate significantly in media under basal or S1PL knockdown conditions, addition of sodium vanadate increased S1P levels in the medium and inside the cells most likely by blocking phosphatases including lipid phosphate phosphatases (LPPs. Furthermore, addition of anti-S1P mAb to the incubation medium blocked S1P(ext or 4-deoxypyridoxine-dependent endothelial cell motility. CONCLUSIONS/SIGNIFICANCE: These results suggest S1P(ext mediated endothelial cell motility is dependent on intracellular S1P production, which is regulated, in part, by SphK1 and S1PL.

  8. Nucleon motion in constant nucleodynamic field (p2 approximation)

    International Nuclear Information System (INIS)

    Karastoyanov, A.

    1979-01-01

    It uses the generalized Dirac equation in the form [-ca vector.(p vector - gA vector/c)+E-V-βmc 2 +(μsub(a)/c)β(σ vector.cB vector-iα vector.E vector] PSI = 0, where α vector and β are the Dirac matrices, c is the velocity of light in vacuum, p vector equals i(h/2π)nabla vector is the pulse operator, g is the nuclear charge, A vector is the nuclear vector potential, E is the total energy of the nucleon, V is its nuclear potential energy, m is its rest mass, μsub(a) = -lambdasub(a)g(h/2π)/2m is the value of the anomalous nuclodynamic dipole moment, σ vector is the Pauli matrix, B vector = rot A vector/c is the nucleodynamic field intensity, i is the imaginary unity, E = -grad V/g is the nucleostatic field intensity, PSI is the Dirac wave function and (h/2π) is the Dirac action constant. For a nucleon in rest the potentials at distance r are V 0 = -(g 2 /4π)[esup(-μr)/r+μEi(-μr)], A vector 0 =(lambda sub(a)-1) (g(h/2π)/2mc) (esup(-μr)/4πr 3 ) (σ vector xr vector) with μ=0,684 fm -1 , αsub(g)=g 2 /4π(h/2π)c=1/4, lambda sub(a)=15.96 = 16 - αsub(g)/2π.αsub(g)/2π is the first order radiation correction, while 16 corresponds to a nuclear analogue of the Dirac magnetic monopole gsub(d) = 16 g = n4π(h/2π)c/2g for n = 8. These values are confirmed by calculations. In the Schroedinger equation approach it explains the spin-spin, tensor and spin-orbit forces, the velocity, energy and state dependence of the nuclear forces, the hard potential core, the ''many-body'' nuclear forces and fine effects of the nuclear interactions. (A.K.)

  9. Evaluation excitation functions for "2"8Si(n,p)"2"8Al, "3"1P(n,p)"3"1Si, and "1"1"3In(n,γ)"1"1"4"mIn reactions

    International Nuclear Information System (INIS)

    Zolotarev, K.I.

    2014-10-01

    Cross section data for "2"8Si(n,p)"2"8Al, "3"1P(n,p)"3"1Si and "1"1"3In(n,γ)"1"1"4"mIn reactions are needed for solving a wide spectrum of scientific and technical tasks. The excitation function of "2"8Si(n,p)"2"8Al reaction refers to the nuclear data involved in fusion reactor design calculations. The "2"8Si(n,p)"2"8Al reaction is interesting also as the monitor reaction for measurements at fusion facilities. Activation detectors on the basis of the 31P(n,p)31Si reaction are commonly used in the reactor dosimetry. The "1"1"3In(n,γ)"1"1"4"mIn reaction is promising regarding reactor dosimetry application for two reasons. First, due to the "1"1"4"mIn decay parameters which are rather suitable for activation measurements. Half-life of "1"1"4"mIn is equal to T_1/_2 = (49.51 ± 0.01) days and gamma spectrum accompanying decay has only one line with energy 190.27 keV and intensity (15.56 ± 0.15)%. Second, the "1"1"3In(n,γ)"1"1"4"mIn reaction rate may be measured by using one activation detector simultaneously with the "1"1"5In(n,γ)"1"1"6"mIn reaction. Preliminary analysis of existing evaluated excitation functions for "2"8Si(n,p)"2"8Al, "3"1P(n,p)"3"1Si and "1"1"3In(n,γ)"1"1"4"mIn reactions show that new evaluations are needed for all above mentioned reactions. This report is devoted to the preparation of the new evaluations of cross sections data and related covariance matrixes of uncertainties for the "2"8Si(n,p)"2"8Al, "3"1P(n,p)"3"1Si and "1"1"3In(n,γ)"1"1"4"mIn reactions.

  10. All-Norm Approximation Algorithms

    NARCIS (Netherlands)

    Azar, Yossi; Epstein, Leah; Richter, Yossi; Woeginger, Gerhard J.; Penttonen, Martti; Meineche Schmidt, Erik

    2002-01-01

    A major drawback in optimization problems and in particular in scheduling problems is that for every measure there may be a different optimal solution. In many cases the various measures are different ℓ p norms. We address this problem by introducing the concept of an All-norm ρ-approximation

  11. Interstitial deletion 1p as a result of a de novo reciprocal 1p;2p translocation

    DEFF Research Database (Denmark)

    Hertz, Jens Michael; Jensen, P H

    1985-01-01

    A 5-month-old female patient with psychomotor retardation and minor dysmorphisms is described. Cytogenetic analysis using high-resolution banding technique revealed an interstitial deletion of the short arm of one chromosome 1 (p21----p22.2) resulting from a de novo translocation t(1;2)(p22;p25)....

  12. Study of the quasi-free scattering at the reaction 2H(p,2p)n at Esub(p)0 = 14.1 MeV

    International Nuclear Information System (INIS)

    Helten, H.J.

    1980-01-01

    The breakup reaction 2 H(p,2p)n was studied at Ep = 14.1 MeV in complete coincidence experiments on quasifree pp scattering in a systematic range of cinematic situations of the pp-subsystem for c.m. production angles between 90 0 and 140 0 and different violation of the quasifree condition as well on interferences with final-state interaction processes. The absolute differential breakup cross section was compared with approximate solutions of the Faddeev equations with separable s-wave potentials without explicite Coulomb interaction according to Ebenhoeh. The agreement is generally good referring to the form of the spectra, but the theoretical amplitude is in the mean 20% to high. The permanent independence of the quasifree breakup from the scattering parameter asub(pp) doesn't suggest to use this process for the determination of nn-scattering lengths from the mirror reaction 2 H(n,2n)p. (orig.)

  13. The Hog1p kinase regulates Aft1p transcription factor to control iron accumulation.

    Science.gov (United States)

    Martins, Telma S; Pereira, Clara; Canadell, David; Vilaça, Rita; Teixeira, Vítor; Moradas-Ferreira, Pedro; de Nadal, Eulàlia; Posas, Francesc; Costa, Vítor

    2018-01-01

    Iron acquisition systems have to be tightly regulated to assure a continuous supply of iron, since it is essential for survival, but simultaneously to prevent iron overload that is toxic to the cells. In budding yeast, the low‑iron sensing transcription factor Aft1p is a master regulator of the iron regulon. Our previous work revealed that bioactive sphingolipids modulate iron homeostasis as yeast cells lacking the sphingomyelinase Isc1p exhibit an upregulation of the iron regulon. In this study, we show that Isc1p impacts on iron accumulation and localization. Notably, Aft1p is activated in isc1Δ cells due to a decrease in its phosphorylation and an increase in its nuclear levels. Consistently, the expression of a phosphomimetic version of Aft1p-S210/S224 that favours its nuclear export abolished iron accumulation in isc1Δ cells. Notably, the Hog1p kinase, homologue of mammalian p38, interacts with and directly phosphorylates Aft1p at residues S210 and S224. However, Hog1p-Aft1p interaction decreases in isc1Δ cells, which likely contributes to Aft1p dephosphorylation and consequently to Aft1p activation and iron overload in isc1Δ cells. These results suggest that alterations in sphingolipid composition in isc1Δ cells may impact on iron homeostasis by disturbing the regulation of Aft1p by Hog1p. To our knowledge, Hog1p is the first kinase reported to directly regulate Aft1p, impacting on iron homeostasis. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Regulation of intracellular pH in LLC-PK1 cells by Na+/H+ exchange.

    Science.gov (United States)

    Montrose, M H; Murer, H

    1986-01-01

    Suspensions of LLC-PK1 cells (a continuous epitheliod cell line with renal characteristics) are examined for mechanisms of intracellular pH regulation using the fluorescent probe BCECF. Initial experiments determine suitable calibration procedures for use of the BCECF fluorescent signal. They also determine that the cell suspension contains cells which (after 4 hr in suspension) have Na+ and K+ gradients comparable to those of cells in monolayer culture. The steady-state intracellular pH (7.05 +/- 0.01, n = 5) of cells which have recovered in (pH 7.4) Na+-containing medium is not affected over several minutes by addition of 100 microM amiloride or removal of extracellular Na+ (Na+o less than 1 mM). In contrast, when the cells recover from an acid load (caused by NH4 preincubation and removal), the recovery is largely Na+ dependent and is sensitive to 100 microM amiloride. These results suggest that with resting pH near neutrality, both Na+o/H+i and Na+i/H+o exchange reactions are functionally inactive (compared to cellular buffering capacity). In contrast, Na+o/H+i exchange is activated by an increased cellular acid load. This activation may be observed directly either as a stimulation of net H+ efflux or net Na+ influx with decreasing intracellular pH. The extrapolation of this latter data suggests a "set point" of Na+/H+ exchange of approximately pH 7.0, consistent with the observed resting intracellular pH of approximately 7.05.

  15. CdS_xTe_1_-_x ternary semiconductors band gaps calculation using ground state and GW approximations

    International Nuclear Information System (INIS)

    Kheloufi, Nawal; Bouzid, Abderrazak

    2016-01-01

    We present band gap calculations of zinc-blende ternary CdS_xTe_1_-_x semiconductors within the standard DFT and quasiparticle calculations employing pseudopotential method. The DFT, the local density approximation (LDA) and the Generalized Gradient Approximation (GGA) based calculations have given very poor results compared to experimental data. The quasiparticle calculations have been investigated via the one-shot GW approximation. The present paper discuses and confirms the effect of inclusion of the semicore states in the cadmium (Cd) pseudopotential. The obtained GW quasiparticle band gap using Cd"+"2"0 pseudopotential has been improved compared to the obtained results from the available pseudopotential without the treatment of semicore states. Our DFT and quasiparticle band gap results are discussed and compared to the available theoretical calculations and experimental data. - Graphical abstract: Band gaps improvement concerning the binary and ternary alloys using the GW approximation and Cd"2"0"+ pseudopotential with others levels of approximations (the LDA and GGA approximation employing the Cd"1"2"+ and the LDA within Cd"2"0"+ pseudopotential). - Highlights: • The direct Γ- Γ and indirect Γ- X and Γ- L bands gaps show a nonlinear behavior when S content is enhanced. • The quasiparticle band gap result for the investigated semiconductors is improved using the GW approximation. • All CdS_xTe_1_-_x compounds in all compositions range from 0 to 1 are direct band gap semiconductors.

  16. Measurement of the k(T) Distribution of Particles in Jets Produced in p anti-p Collisions at s**(1/2) = 1.96-TeV

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, J.; /Chicago U., EFI; Akimoto, T.; /Tsukuba U.; Alvarez Gonzalez, B.; /CSIC, Catalunya; Amerio, S.; /INFN, Padua; Amidei, Dante E.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, Alberto; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.

    2008-11-01

    We present a measurement of the transverse momentum with respect to the jet axis (k{sub T}) of particles in jets produced in p{bar p} collisions at {radical}s = 1.96 TeV. Results are obtained for charged particles within a cone of opening angle 0.5 radians around the jet axis in events with dijet invariant masses between 66 and 737 GeV/c{sup 2}. The experimental data are compared to theoretical predictions obtained for fragmentation partons within the framework of resummed perturbative QCD using the modified leading log and next-to-modified leading log approximations. The comparison shows that trends in data are successfully described by the theoretical predictions, indicating that the perturbative QCD stage of jet fragmentation is dominant in shaping basic jet characteristics.

  17. Dielectronic recombination of P5+ and Cl7+ in configuration-average, LS-coupling, and intermediate-coupling approximations

    International Nuclear Information System (INIS)

    Badnell, N.R.; Pindzola, M.S.

    1989-01-01

    We have calculated dielectronic recombination cross sections and rate coefficients for the Ne-like ions P 5+ and Cl 7+ in configuration-average, LS-coupling, and intermediate-coupling approximations. Autoionization into excited states reduces the cross sections and rate coefficients by substantial amounts in all three methods. There is only rough agreement between the configuration-average cross-section results and the corresponding intermediate-coupling results. There is good agreement, however, between the LS-coupling cross-section results and the corresponding intermediate-coupling results. The LS-coupling and intermediate-coupling rate coefficients agree to better than 5%, while the configuration-average rate coefficients are about 30% higher than the other two coupling methods. External electric field effects, as calculated in the configuration-average approximation, are found to be relatively small for the cross sections and completely negligible for the rate coefficients. Finally, the general formula of Burgess was found to overestimate the rate coefficients by roughly a factor of 5, mainly due to the neglect of autoionization into excited states

  18. Structural and electronic properties of zinc blende B{sub x}Al{sub 1-x}N{sub y}P{sub 1-y} quaternary alloys via first-principle calculations

    Energy Technology Data Exchange (ETDEWEB)

    Abdiche, A., E-mail: abdiche_a@yahoo.fr [Engineering Physics Laboratory, Tiaret University, 14000 Tiaret (Algeria); Baghdad, R. [Engineering Physics Laboratory, Tiaret University, 14000 Tiaret (Algeria); Khenata, R., E-mail: khenata_rabah@yahoo.fr [Laboratoire de Physique Quantique et de Modelisation Mathematique (LPQ3M), Departement de Technologie, Universite de Mascara, 29000 Mascara (Algeria); Department of Physics and Astronomy, King Saud University, P.O Box 2455, Riyadh 11451 (Saudi Arabia); Riane, R. [Computational Materials Science Laboratory, University Research of Sidi-Bel-Abbes, 22000 Algeria (Algeria); Al-Douri, Y. [Institute of Nono Electronic Engineering, University Malaysia Perlis, 01000 Kangar, Perlis (Malaysia); Guemou, M. [Engineering Physics Laboratory, Tiaret University, 14000 Tiaret (Algeria); Bin-Omran, S. [Department of Physics and Astronomy, King Saud University, P.O Box 2455, Riyadh 11451 (Saudi Arabia)

    2012-02-01

    The structural and electronic properties of cubic zinc blende BN, BP, AlN and AlP compounds and their B{sub x}Al{sub 1-x}N{sub y}P{sub 1-y} quaternary alloys, have been calculated using the non relativistic full-potential linearized-augmented plane wave FP-LAPW method. The exchange-correlation potential is treated with the local density approximation of Perdew and Wang (LDA-PW) as well as the generalized gradient approximation (GGA) of Perdew-Burke and Ernzerhof (GGA-PBE). The calculated structural properties of BN, BP, AlN and AlP compounds are in good agreement with the available experimental and theoretical data. A nonlinear variation of compositions x and y with the lattice constants, bulk modulus, direct and indirect band gaps is found. The calculated bowing of the fundamental band gaps is in good agreement with the available experimental and theoretical value. To our knowledge this is the first quantitative theoretical investigation on B{sub x}Al{sub 1-x}N{sub y}P{sub 1-y} quaternary alloy and still awaits experimental confirmations.

  19. Efficient anisotropic quasi-P wavefield extrapolation using an isotropic low-rank approximation

    KAUST Repository

    Zhang, Zhendong

    2017-12-17

    The computational cost of quasi-P wave extrapolation depends on the complexity of the medium, and specifically the anisotropy. Our effective-model method splits the anisotropic dispersion relation into an isotropic background and a correction factor to handle this dependency. The correction term depends on the slope (measured using the gradient) of current wavefields and the anisotropy. As a result, the computational cost is independent of the nature of anisotropy, which makes the extrapolation efficient. A dynamic implementation of this approach decomposes the original pseudo-differential operator into a Laplacian, handled using the low-rank approximation of the spectral operator, plus an angular dependent correction factor applied in the space domain to correct for anisotropy. We analyze the role played by the correction factor and propose a new spherical decomposition of the dispersion relation. The proposed method provides accurate wavefields in phase and more balanced amplitudes than a previous spherical decomposition. Also, it is free of SV-wave artifacts. Applications to a simple homogeneous transverse isotropic medium with a vertical symmetry axis (VTI) and a modified Hess VTI model demonstrate the effectiveness of the approach. The Reverse Time Migration (RTM) applied to a modified BP VTI model reveals that the anisotropic migration using the proposed modeling engine performs better than an isotropic migration.

  20. The reactions of p-nitroacetophenone with H and OH radicals

    International Nuclear Information System (INIS)

    Whillans, D.W.

    1977-01-01

    Reactions of the radiation sensitizer p-nitroacetophenone (PNAP) with H and OH radicals have been studied in detail. PNAP reacts with OH (k = (3.3 + 0.3) X 10 9 dm 3 mol -1 s -1 ), presumably in the main by ring addition, to produce a relatively weak absorption with a minor peak at 410 nm (epsilon approximately 2,000 dm 3 mol -1 cm -1 ). In contrast the electron adduct has a very strong absorption with peaks at 350 nm (epsilon approximately 18,200 dm 3 mol -1 cm -1 ) and 550 nm (epsilon approximately 2650 dm 3 mol -1 cm -1 ), in good agreement with literature values. At pH 1 the protonated adduct shows a single peak at 330 nm (epsilon approximately 20,500 dm 3 mol -1 cm -1 ). The spectra produced by reaction of PNAP with H atoms (k = (6 + - 0. 5) x 10 8 dm 3 mol -1 s -1 ) is intermediate between those with OH and with e - sub(aq), with peaks at 350 (epsilon approximately 7100 dm 3 mol -1 cm -1 ) and 550 nm (750 dm 3 mol -1 cm -1 ) at neutral pH and near 325 nm (epsilon approximately 7100 dm 3 mol -1 cm -1 ) at pH 1, but with significant shoulders near 410 nm. These data are consistent with a mechanism whereby H atoms react partially by addition to the nitro group (approximately 30%) and partially by ring addition (approximately 70%). (author)

  1. Calculation of the total electron excitation cross section in the Born approximation using Slater wave functions for the Li (2s yields 2p), Li (2s yields 3p), Na (3s yields 4p), Mg (3p yields 4s), Ca (4s yields 4p) and K (4s yields 4p) excitations. M.S. Thesis

    Science.gov (United States)

    Simsic, P. L.

    1974-01-01

    Excitation of neutral atoms by inelastic scattering of incident electrons in gaseous nebulae were investigated using Slater Wave functions to describe the initial and final states of the atom. Total cross sections using the Born Approximation are calculated for: Li(2s yields 2p), Na(3s yields 4p), k(4s yields 4p). The intensity of emitted radiation from gaseous nebulae is also calculated, and Maxwell distribution is employed to average the kinetic energy of electrons.

  2. [Role and related mechanism of S1P/S1P1 signal pathway during post conditioning of hypertrophic cardiomyocytes].

    Science.gov (United States)

    Bao, X H; Li, H X; Tao, J; Li, X M; Yang, Y N; Ma, Y T; Chen, B D

    2016-05-24

    To study the role and mechanism of sphingosine-1-phosphate (S1P)/ sphingosine-1-phosphate receptor 1(S1P1) signal pathway during post conditioning of hypertrophic cardiomyocytes. Neonatal rat cardiomyocytes were isolated and cultured, then stimulated by norepinephrine (NE) to induce cardiomyocytes hypertrophy. Using tri-gas incubator to create hypoxia and reoxygenation enviroment to mimic ischemia-reperfusion and postconditioning. Hypertrophic cardiomyoctyes were divided into five groups according to the presence or absence of various drugs and postconditiong and relevant signal pathways changes were detected: (1) IPost group (hypoxia+ postconditioning); (2) IPost+ S1P group (cells were pretreated with S1P (1 μmol/L) for 2 h before IPost); (3) IPost+ W-146+ S1P group (cells in IPost+ W-146+ S1P group were pretreated with S1P1 inhibitor W-146 (0.4 μmol/L) for 20 min); (4) IPost+ PD98059+ S1P group (cells in IPost+ S1P group were pretreated with MAPK antagonist PD98059 (125 μmol/L) for 20 min); (5) IPost+ LY-294002+ S1P group (cells in IPost+ S1P group were pretreated with PI3K antagonist LY294002 (0.1 μmol/L) for 20 min). Apoptosis was detected by flow cytometry and protein expression of relevant signal pathways were detected by Western blot. (1)Apoptosis rate was significantly increased in hypoxia/reoxygenation (27.90±4.49)% group compared with normal control group (7.97±2.18)%, which could be significantly reduced in IPost group (15.90±1.77)% (all PS1P and IPost+ S1P+ LY-294002 groups than in IPost and IPost+ S1P+ W-146 and IPost+ S1P+ PD98059 group (all PS1P and IPost+ S1P+ LY-294002 group than in IPost and IPost+ S1P+ W-146 group and IPost+ S1P+ PD98059 group (all PS1P+ W-146 and IPost+ S1P+ PD98059 groups. p-ERK1/2 and p-Akt levels in IPost+ S1P+ W-146 group and IPost+ S1P+ PD98059 were similar as in IPost group. S1P can play protective role on NE induced cardiomyocytes hypertrophy during post conditioning through downregulating caspase-3 expression and

  3. Sphingosine-1-Phosphate (S1P) and S1P Signaling Pathway: Therapeutic Targets in Autoimmunity and Inflammation.

    Science.gov (United States)

    Tsai, Hsing-Chuan; Han, May H

    2016-07-01

    Sphingosine-1-phosphate (S1P) and S1P receptors (S1PR) are ubiquitously expressed. S1P-S1PR signaling has been well characterized in immune trafficking and activation in innate and adaptive immune systems. However, the full extent of its involvement in the pathogenesis of autoimmune diseases is not well understood. FTY720 (fingolimod), a non-selective S1PR modulator, significantly decreased annualized relapse rates in relapsing-remitting multiple sclerosis (MS). FTY720, which primarily targets S1P receptor 1 as a functional antagonist, arrests lymphocyte egress from secondary lymphoid tissues and reduces neuroinflammation in the central nervous system (CNS). Recent studies suggest that FTY720 also decreases astrogliosis and promotes oligodendrocyte differentiation within the CNS and may have therapeutic benefit to prevent brain atrophy. Since S1P signaling is involved in multiple immune functions, therapies targeting S1P axis may be applicable to treat autoimmune diseases other than MS. Currently, over a dozen selective S1PR and S1P pathway modulators with potentially superior therapeutic efficacy and better side-effect profiles are in the pipeline of drug development. Furthermore, newly characterized molecules such as apolipoprotein M (ApoM) (S1P chaperon) and SPNS2 (S1P transporter) are also potential targets for treatment of autoimmune diseases. Finally, the application of therapies targeting S1P and S1P signaling pathways may be expanded to treat several other immune-mediated disorders (such as post-infectious diseases, post-stroke and post-stroke dementia) and inflammatory conditions beyond their application in primary autoimmune diseases.

  4. Association of Sphingosine-1-phosphate (S1P)/S1P Receptor-1 Pathway with Cell Proliferation and Survival in Canine Hemangiosarcoma.

    Science.gov (United States)

    Rodriguez, A M; Graef, A J; LeVine, D N; Cohen, I R; Modiano, J F; Kim, J-H

    2015-01-01

    Sphingosine-1-phosphate (S1P) is a key biolipid signaling molecule that regulates cell growth and survival, but it has not been studied in tumors from dogs. S1P/S1P1 signaling will contribute to the progression of hemangiosarcoma (HSA). Thirteen spontaneous HSA tissues, 9 HSA cell lines, 8 nonmalignant tissues, including 6 splenic hematomas and 2 livers with vacuolar degeneration, and 1 endothelial cell line derived from a dog with splenic hematoma were used. This was a retrospective case series and in vitro study. Samples were obtained as part of medically necessary diagnostic procedures. Microarray, qRT-PCR, immunohistochemistry, and immunoblotting were performed to examine S1P1 expression. S1P concentrations were measured by high-performance liquid chromatography/mass spectrometry. S1P signaling was evaluated by intracellular Ca(2+) mobilization; proliferation and survival were evaluated using the MTS assay and Annexin V staining. Canine HSA cells expressed higher levels of S1P1 mRNA than nonmalignant endothelial cells. S1P1 protein was present in HSA tissues and cell lines. HSA cells appeared to produce low levels of S1P, but they selectively consumed S1P from the culture media. Exogenous S1P induced an increase in intracellular calcium as well as increased proliferation and viability of HSA cells. Prolonged treatment with FTY720, an inhibitor of S1P1 , decreased S1P1 protein expression and induced apoptosis of HSA cells. S1P/S1P1 signaling pathway functions to maintain HSA cell viability and proliferation. The data suggest that S1P1 or the S1P pathway in general could be targets for therapeutic intervention for dogs with HSA. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  5. Intracellular S1P Generation Is Essential for S1P-Induced Motility of Human Lung Endothelial Cells: Role of Sphingosine Kinase 1 and S1P Lyase

    Science.gov (United States)

    Berdyshev, Evgeny V.; Gorshkova, Irina; Usatyuk, Peter; Kalari, Satish; Zhao, Yutong; Pyne, Nigel J.; Pyne, Susan; Sabbadini, Roger A.; Garcia, Joe G. N.; Natarajan, Viswanathan

    2011-01-01

    Background Earlier we have shown that extracellular sphingosine-1-phosphate (S1P) induces migration of human pulmonary artery endothelial cells (HPAECs) through the activation of S1P1 receptor, PKCε, and PLD2-PKCζ-Rac1 signaling cascade. As endothelial cells generate intracellular S1P, here we have investigated the role of sphingosine kinases (SphKs) and S1P lyase (S1PL), that regulate intracellular S1P accumulation, in HPAEC motility. Methodology/Principal Findings Inhibition of SphK activity with a SphK inhibitor 2-(p-Hydroxyanilino)-4-(p-Chlorophenyl) Thiazole or down-regulation of Sphk1, but not SphK2, with siRNA decreased S1Pint, and attenuated S1Pext or serum-induced motility of HPAECs. On the contrary, inhibition of S1PL with 4-deoxypyridoxine or knockdown of S1PL with siRNA increased S1Pint and potentiated motility of HPAECs to S1Pext or serum. S1Pext mediates cell motility through activation of Rac1 and IQGAP1 signal transduction in HPAECs. Silencing of SphK1 by siRNA attenuated Rac1 and IQGAP1 translocation to the cell periphery; however, knockdown of S1PL with siRNA or 4-deoxypyridoxine augmented activated Rac1 and stimulated Rac1 and IQGAP1 translocation to cell periphery. The increased cell motility mediated by down-regulation was S1PL was pertussis toxin sensitive suggesting “inside-out” signaling of intracellularly generated S1P. Although S1P did not accumulate significantly in media under basal or S1PL knockdown conditions, addition of sodium vanadate increased S1P levels in the medium and inside the cells most likely by blocking phosphatases including lipid phosphate phosphatases (LPPs). Furthermore, addition of anti-S1P mAb to the incubation medium blocked S1Pext or 4-deoxypyridoxine-dependent endothelial cell motility. Conclusions/Significance These results suggest S1Pext mediated endothelial cell motility is dependent on intracellular S1P production, which is regulated, in part, by SphK1 and S1PL. PMID:21304987

  6. Simple approximations for the batch-arrival MX/G/1 queue

    NARCIS (Netherlands)

    van Ommeren, Jan C.W.

    1990-01-01

    In this paper we consider the MX/G/I queueing system with batch arrivals. We give simple approximations for the waiting-time probabilities of individual customers. These approximations are checked numerically and they are found to perform very well for a wide variety of batch-size and service-timed

  7. Yeast Ivy1p Is a Putative I-BAR-domain Protein with pH-sensitive Filament Forming Ability in vitro.

    Science.gov (United States)

    Itoh, Yuzuru; Kida, Kazuki; Hanawa-Suetsugu, Kyoko; Suetsugu, Shiro

    2016-01-01

    Bin-Amphiphysin-Rvs161/167 (BAR) domains mold lipid bilayer membranes into tubules, by forming a spiral polymer on the membrane. Most BAR domains are thought to be involved in forming membrane invaginations through their concave membrane binding surfaces, whereas some members have convex membrane binding surfaces, and thereby mold membranes into protrusions. The BAR domains with a convex surface form a subtype called the inverse BAR (I-BAR) domain or IRSp53-MIM-homology domain (IMD). Although the mammalian I-BAR domains have been studied, those from other organisms remain elusive. Here, we found putative I-BAR domains in Fungi and animal-like unicellular organisms. The fungal protein containing the putative I-BAR-domain is known as Ivy1p in yeast, and is reportedly localized in the vacuole. The phylogenetic analysis of the I-BAR domains revealed that the fungal I-BAR-domain containing proteins comprise a distinct group from those containing IRSp53 or MIM. Importantly, Ivy1p formed a polymer with a diameter of approximately 20 nm in vitro, without a lipid membrane. The filaments were formed at neutral pH, but disassembled when pH was reverted to basic. Moreover, Ivy1p and the I-BAR domain expressed in mammalian HeLa cells was localized at a vacuole-like structure as filaments as revealed by super-resolved microscopy. These data indicate the pH-sensitive polymer forming ability and the functional conservation of Ivy1p in eukaryotic cells.

  8. Polynomial approximation on polytopes

    CERN Document Server

    Totik, Vilmos

    2014-01-01

    Polynomial approximation on convex polytopes in \\mathbf{R}^d is considered in uniform and L^p-norms. For an appropriate modulus of smoothness matching direct and converse estimates are proven. In the L^p-case so called strong direct and converse results are also verified. The equivalence of the moduli of smoothness with an appropriate K-functional follows as a consequence. The results solve a problem that was left open since the mid 1980s when some of the present findings were established for special, so-called simple polytopes.

  9. Approximate P-wave ray tracing and dynamic ray tracing in weakly orthorhombic media of varying symmetry orientation

    KAUST Repository

    Masmoudi, Nabil; Pšenčí k, Ivan

    2014-01-01

    We present an approximate, but efficient and sufficiently accurate P-wave ray tracing and dynamic ray tracing procedure for 3D inhomogeneous, weakly orthorhombic media with varying orientation of symmetry planes. In contrast to commonly used approaches, the orthorhombic symmetry is preserved at any point of the model. The model is described by six weak-anisotropy parameters and three Euler angles, which may vary arbitrarily, but smoothly, throughout the model. We use the procedure for the calculation of rays and corresponding two-point traveltimes in a VSP experiment in a part of the BP benchmark model generalized to orthorhombic symmetry.

  10. U.S. Department Of Energy's nuclear engineering education research: highlights of recent and current research-II. 1. Comparison of Angular Approximations for PWR Cell Calculations

    International Nuclear Information System (INIS)

    Smith, M.A.; Tsoulfanidis, N.; Lewis, E.E.; Palmiotti, G.

    2001-01-01

    Increasing computer power is allowing higher-order angular approximations to replace diffusion theory methods in whole core reactor physics computations. Spherical harmonic (P n ), simplified spherical harmonic (SP n ), and discrete ordinates (S n ) methods are capable of performing such calculations in three dimensions. Most advantages of such transport methods are gained by eliminating fuel assembly homogenization, thus allowing pin powers to be calculated directly. A further step, currently under investigation, is the elimination of spatial homogenization at the pin cell level as well. The fuel-moderator interfaces may be treated explicitly in P n , S n , or SP n calculations by applying triangular finite elements (FEM) to the spatial variables. Early results using a modified form of the VARIANT code, however, indicate that without pin cell homogenization, high-order angular approximations may be required to represent the lattice effects accurately within the whole-core calculations. To examine these lattice effects further, a modified form of VARIANT was created to use the spatial triangular finite element scheme. The program was set up to treat a single heterogeneous pin cell coupled with P n , SP n , or S n angular approximations. Additional modifications replaced the nodal interface approximations with exact reflected boundary conditions to increase the accuracy of the results. Several pressurized water reactor pin cells, taken from a previous benchmark specification, were examined. However, the results shown here focus only on the most severe case, i.e., a pin cell containing 8.7% mixed-oxide enriched fuel. The DRAGON collision probability code was used to collapse a 69-group cross-section library to a more manageable 7-group library that contained cross sections for the fuel-cladding mixture and for the water. Eigenvalue results are shown in Figs. 1 and 2 using the modified VARIANT code with P n , SP n , and S n angular approximations. A 7-group MCNP Monte

  11. Perturbation expansions generated by an approximate propagator

    International Nuclear Information System (INIS)

    Znojil, M.

    1987-01-01

    Starting from a knowledge of an approximate propagator R at some trial energy guess E 0 , a new perturbative prescription for p-plet of bound states and of their energies is proposed. It generalizes the Rayleigh-Schroedinger (RS) degenerate perturbation theory to the nondiagonal operators R (eliminates a RS need of their diagnolisation) and defines an approximate Hamiltonian T by mere inversion. The deviation V of T from the exact Hamiltonian H is assumed small only after a substraction of a further auxiliary Hartree-Fock-like separable ''selfconsistent'' potential U of rank p. The convergence is illustrated numerically on the anharmonic oscillator example

  12. 1H(d,2p)n reaction at 2 GeV deuteron energy

    International Nuclear Information System (INIS)

    Erohuml, J.; Fodor, Z.; Koncz, P.; Seres, Z.; Perdrisat, C.F.; Punjabi, V.; Boudard, A.; Bonin, B.; Garcon, M.; Lombard, R.; Mayer, B.; Terrien, Y.; Tomasi, E.; Boivin, M.; Yonnet, J.; Bhang, H.C.; Youn, M.; Belostotsky, S.L.; Grebenuk, O.G.; Nikulin, V.N.; Kudin, L.G.

    1994-01-01

    The 1 H(d,2p)n deuteron breakup reaction was measured at 2 GeV deuteron energy in a kinematically complete experiment. Fivefold differential cross sections are given in a wide range of kinematical variables and analyzed in terms of impulse approximation and NN rescattering. The deuteron momentum density was determined and deviations were found depending on the value of the four-momentum transfer |t| in the scattering process. At low |t| the momentum densities are in good agreement with the impulse approximation whereas large discrepancies were found above q∼200 MeV/c when the four-momentum transfer was large. Various possible origins of the anomalous behavior at high q values are discussed

  13. Singlet structure function F_1 in double-logarithmic approximation

    Science.gov (United States)

    Ermolaev, B. I.; Troyan, S. I.

    2018-03-01

    The conventional ways to calculate the perturbative component of the DIS singlet structure function F_1 involve approaches based on BFKL which account for the single-logarithmic contributions accompanying the Born factor 1 / x. In contrast, we account for the double-logarithmic (DL) contributions unrelated to 1 / x and because of that they were disregarded as negligibly small. We calculate the singlet F_1 in the double-logarithmic approximation (DLA) and account at the same time for the running α _s effects. We start with a total resummation of both quark and gluon DL contributions and obtain the explicit expression for F_1 in DLA. Then, applying the saddle-point method, we calculate the small- x asymptotics of F_1, which proves to be of the Regge form with the leading singularity ω _0 = 1.066. Its large value compensates for the lack of the factor 1 / x in the DLA contributions. Therefore, this Reggeon can be identified as a new Pomeron, which can be quite important for the description of all QCD processes involving the vacuum (Pomeron) exchanges at very high energies. We prove that the expression for the small- x asymptotics of F_1 scales: it depends on a single variable Q^2/x^2 only instead of x and Q^2 separately. Finally, we show that the small- x asymptotics reliably represent F_1 at x ≤ 10^{-6}.

  14. Sphingosine-1-Phosphate Mediates ICAM-1-Dependent Monocyte Adhesion through p38 MAPK and p42/p44 MAPK-Dependent Akt Activation

    Science.gov (United States)

    Lin, Chih-Chung; Lee, I-Ta; Hsu, Chun-Hao; Hsu, Chih-Kai; Chi, Pei-Ling; Hsiao, Li-Der; Yang, Chuen-Mao

    2015-01-01

    Up-regulation of intercellular adhesion molecule-1 (ICAM-1) is frequently implicated in lung inflammation. Sphingosine-1-phosphate (S1P) has been shown to play a key role in inflammation via adhesion molecules induction, and then causes lung injury. However, the mechanisms underlying S1P-induced ICAM-1 expression in human pulmonary alveolar epithelial cells (HPAEpiCs) remain unclear. The effect of S1P on ICAM-1 expression was determined by Western blot and real-time PCR. The involvement of signaling pathways in these responses was investigated by using the selective pharmacological inhibitors and transfection with siRNAs. S1P markedly induced ICAM-1 expression and monocyte adhesion which were attenuated by pretreatment with the inhibitor of S1PR1 (W123), S1PR3 (CAY10444), c-Src (PP1), EGFR (AG1478), PDGFR (AG1296), MEK1/2 (U0126), p38 MAPK (SB202190), JNK1/2 (SP600125), PI3K (LY294002), or AP-1 (Tanshinone IIA) and transfection with siRNA of S1PR1, S1PR3, c-Src, EGFR, PDGFR, p38, p42, JNK1, c-Jun, or c-Fos. We observed that S1P-stimulated p42/p44 MAPK and p38 MAPK activation was mediated via a c-Src/EGFR and PDGFR-dependent pathway. S1P caused the c-Src/EGFR/PDGFR complex formation. On the other hand, we demonstrated that S1P induced p42/p44 MAPK and p38 MAPK-dependent Akt activation. In addition, S1P-stimulated JNK1/2 phosphorylation was attenuated by SP600125 or PP1. Finally, S1P enhanced c-Fos mRNA levels and c-Jun phosphorylation. S1P-induced c-Jun activation was reduced by PP1, AG1478, AG1296, U0126, SP600125, SB202190, or LY294002. These results demonstrated that S1P-induced ICAM-1 expression and monocyte adhesion were mediated through S1PR1/3/c-Src/EGFR, PDGFR/p38 MAPK, p42/p44 MAPK/Akt-dependent AP-1 activation. PMID:25734900

  15. p53-dependent inhibition of TrxR1 contributes to the tumor-specific induction of apoptosis by RITA.

    Science.gov (United States)

    Hedström, Elisabeth; Eriksson, Sofi; Zawacka-Pankau, Joanna; Arnér, Elias S J; Selivanova, Galina

    2009-11-01

    Thioredoxin reductase 1 (TrxR1) is a key regulator in many redox-dependent cellular pathways, and is often overexpressed in cancer. Several studies have identified TrxR1 as a potentially important target for anticancer therapy. The low molecular weight compound RITA (NSC 652287) binds p53 and induces p53-dependent apoptosis. Here we found that RITA also targets TrxR1 by non-covalent binding, followed by inhibition of its activity in vitro and by inhibition of TrxR activity in cancer cells. Interestingly, a novel approximately 130 kDa form of TrxR1, presumably representing a stable covalently linked dimer, and an increased generation of reactive oxygen species (ROS) were induced by RITA in cancer cells in a p53-dependent manner. Similarly, the gold-based TrxR inhibitor auranofin induced apoptosis related to oxidative stress, but independently of p53 and without apparent induction of the approximately 130 kDa form of TrxR1. In contrast to the effects observed in cancer cells, RITA did not inhibit TrxR or ROS formation in normal fibroblasts (NHDF). The inhibition of TrxR1 can sensitize tumor cells to agents that induce oxidative stress and may directly trigger cell death. Thus, our results suggest that a unique p53-dependent effect of RITA on TrxR1 in cancer cells might synergize with p53-dependent induction of pro-apoptotic genes and oxidative stress, thereby leading to a robust induction of cancer cell death, without affecting non-transformed cells.

  16. Confinement in Maxwell-Chern-Simons planar quantum electrodynamics and the 1/N approximation

    International Nuclear Information System (INIS)

    Hofmann, Christoph P.; Raya, Alfredo; Madrigal, Saul Sanchez

    2010-01-01

    We study the analytical structure of the fermion propagator in planar quantum electrodynamics coupled to a Chern-Simons term within a four-component spinor formalism. The dynamical generation of parity-preserving and parity-violating fermion mass terms is considered, through the solution of the corresponding Schwinger-Dyson equation for the fermion propagator at leading order of the 1/N approximation in Landau gauge. The theory undergoes a first-order phase transition toward chiral symmetry restoration when the Chern-Simons coefficient θ reaches a critical value which depends upon the number of fermion families considered. Parity-violating masses, however, are generated for arbitrarily large values of the said coefficient. On the confinement scenario, complete charge screening - characteristic of the 1/N approximation - is observed in the entire (N,θ)-plane through the local and global properties of the vector part of the fermion propagator.

  17. The 2s1/2 → 2p1/2 + one photon transition in hydrogen and hydrogenlike ions

    International Nuclear Information System (INIS)

    Kelsey, E.J.

    1977-01-01

    The 2s 1 / 2 → 2p 1 / 2 + one photon transition rate is calculated and discussed for hydrogen and hydrogenlike ions. It is noted that the induced transition rather than the spontaneous transition is of primary importance since it is the basis of many of the precision Lamb-shift measurements. The lack of a calculation of the transition rate other than a heuristic nonrelativistic derivation which requires a nontrivial assumption motivates the calculation presented here based on the external field approximation to quantum electrodynamics. It is found that the heuristic answer is correct in lowest order. In this derivation we see that the 2s 1 / 2 → 2p 1 / 2 + one photon transition gives an apparent contradiction to the often-stated remark that for the electric dipole matrix element there exist three equivalent representations, the ''length,'' ''velocity,'' and ''acceleration'' forms. The difficulties of an experimental determination of this transition rate using induced transitions in hydrogenlike ions are briefly noted as well as the somewhat different case of heavy muonic atoms where the spontaneous 2s 1 / 2 → 2p 1 / 2 + one photon transition has been observed

  18. Sphingosine kinase 1/sphingosine-1-phosphate (S1P)/S1P receptor axis is involved in ovarian cancer angiogenesis.

    Science.gov (United States)

    Dai, Lan; Liu, Yixuan; Xie, Lei; Wu, Xia; Qiu, Lihua; Di, Wen

    2017-09-26

    Sphingosine kinase (SphK)/sphingosine-1-phosphate (S1P)/S1P receptor (S1PR) signaling pathway has been implicated in a variety of pathological processes of ovarian cancer. However, the function of this axis in ovarian cancer angiogenesis remains incompletely defined. Here we provided the first evidence that SphK1/S1P/S1PR 1/3 pathway played key roles in ovarian cancer angiogenesis. The expression level of SphK1, but not SphK2, was closely correlated with the microvascular density (MVD) of ovarian cancer tissue. In vitro , the angiogenic potential and angiogenic factor secretion of ovarian cancer cells could be attenuated by SphK1, but not SphK2, blockage and were restored by the addition of S1P. Moreover, in these cells, we found S1P stimulation induced the angiogenic factor secretion via S1PR 1 and S1PR 3 , but not S1PR 2 . Furthermore, inhibition of S1PR 1/3 , but not S1PR 2 , attenuated the angiogenic potential and angiogenic factor secretion of the cells. in vivo , blockage of SphK or S1PR 1/3 could attenuate ovarian cancer angiogenesis and inhibit angiogenic factor expression in mouse models. Collectively, the current study showed a novel role of SphK1/S1P/S1PR 1/3 axis within the ovarian cancer, suggesting a new target to block ovarian cancer angiogenesis.

  19. Approximate reflection coefficients for a thin VTI layer

    KAUST Repository

    Hao, Qi

    2017-09-18

    We present an approximate method to derive simple expressions for the reflection coefficients of P- and SV-waves for a thin transversely isotropic layer with a vertical symmetry axis (VTI) embedded in a homogeneous VTI background. The layer thickness is assumed to be much smaller than the wavelengths of P- and SV-waves inside. The exact reflection and transmission coefficients are derived by the propagator matrix method. In the case of normal incidence, the exact reflection and transmission coefficients are expressed in terms of the impedances of vertically propagating P- and S-waves. For subcritical incidence, the approximate reflection coefficients are expressed in terms of the contrast in the VTI parameters between the layer and the background. Numerical examples are designed to analyze the reflection coefficients at normal and oblique incidence, and investigate the influence of transverse isotropy on the reflection coefficients. Despite giving numerical errors, the approximate formulae are sufficiently simple to qualitatively analyze the variation of the reflection coefficients with the angle of incidence.

  20. An interesting charmonium state formation and decay: p p-bar → 1 D2 → 1 P1γ

    International Nuclear Information System (INIS)

    Anselmino, M.; Caruso, F.; Universidade do Estado, Rio de Janeiro, RJ; Murgia, F.; Negrao, M.R.

    1994-01-01

    Massless perturbative QCD forbids, at leading order, the exclusive annihilation of proton-antiproton into some charmonium states, which however, have been observed in the pp channel, indicating the significance of higher order and non perturbative effects in the few GeV energy region. The most well known cases are those of the 1 S 0 (η c ) and the 1 P 1 . The case of the 1 D 2 is considered here and a way of detecting such a state through its typical angular distribution in the radiative decay 1 D 2 -> 1 D 2 -> 1 P 1 γ is suggested. Estimates of the branching ratio BR( 1 D 2 ->pp), as given by a quark-diquark model of the nucleon, mass corrections and an instanton induced process are presented. (author). 15 refs

  1. The {P,Q,k+1}-Reflexive Solution to System of Matrix Equations AX=C, XB=D

    Directory of Open Access Journals (Sweden)

    Chang-Zhou Dong

    2015-01-01

    Full Text Available Let P∈Cm×m and Q∈Cn×n be Hermitian and {k+1}-potent matrices; that is, Pk+1=P=P⁎ and Qk+1=Q=Q⁎, where ·⁎ stands for the conjugate transpose of a matrix. A matrix X∈Cm×n is called {P,Q,k+1}-reflexive (antireflexive if PXQ=X (PXQ=-X. In this paper, the system of matrix equations AX=C and XB=D subject to {P,Q,k+1}-reflexive and antireflexive constraints is studied by converting into two simpler cases: k=1 and k=2. We give the solvability conditions and the general solution to this system; in addition, the least squares solution is derived; finally, the associated optimal approximation problem for a given matrix is considered.

  2. On p-mode oscillations in stars from 1 solar mass to 2 solar masses

    Science.gov (United States)

    Audard, N.; Provost, J.

    1994-06-01

    The structure of stars more massive than about 1.2 solar masses is characterized by a convective core. We have studied the evolution with age and mass of acoustic frequencies of high radical order n and low degree l for models of stars of 1, 1.5 and 2 solar masses. Using a polynomial approximation for the frequency, the p-mode spectrum can be characterized by derived global asteroseismic coefficients, i.e. the mean separation nu0 is approximately equal to nun, l - nun - 1, l and the small frequency separation Delta nu0, 2 is approximately equal to nun, l = 0 - nun - 1, l = 2. The diagram (nu0, delta nu0, 2/nu0) plotted along the evolutionary tracks would help to separate the effects of age and mass. We study the sensitivity of these coefficients and other observable quantities, like the radius and luminosity, to stellar parameters in the vicinity of 1 solar mass and 2 solar masses; this sensitivity substantially depends on the stellar mass and must be taken into account for asteroseismic calibration of stellar clusters. Considering finally some rapid variations of the internal structure, we show that the second frequency difference delta2 nu = nu(subn, l) - 2 nun - 1, l + nun - 2, l exponent gamma in the He II ionization zone.

  3. Capped Lp approximations for the composite L0 regularization problem

    OpenAIRE

    Li, Qia; Zhang, Na

    2017-01-01

    The composite L0 function serves as a sparse regularizer in many applications. The algorithmic difficulty caused by the composite L0 regularization (the L0 norm composed with a linear mapping) is usually bypassed through approximating the L0 norm. We consider in this paper capped Lp approximations with $p>0$ for the composite L0 regularization problem. For each $p>0$, the capped Lp function converges to the L0 norm pointwisely as the approximation parameter tends to infinity. We point out tha...

  4. Entropy Viscosity and L1-based Approximations of PDEs: Exploiting Sparsity

    Science.gov (United States)

    2015-10-23

    AFRL-AFOSR-VA-TR-2015-0337 Entropy Viscosity and L1-based Approximations of PDEs: Exploiting Sparsity Jean-Luc Guermond TEXAS A & M UNIVERSITY 750...REPORT DATE (DD-MM-YYYY) 09-05-2015 2. REPORT TYPE Final report 3. DATES COVERED (From - To) 01-07-2012 - 30-06-2015 4. TITLE AND SUBTITLE Entropy ...conservation equations can be stabilized by using the so-called entropy viscosity method and we proposed to to investigate this new technique. We

  5. Efficient anisotropic quasi-P wavefield extrapolation using an isotropic low-rank approximation

    KAUST Repository

    Zhang, Zhendong; Liu, Yike; Alkhalifah, Tariq Ali; Wu, Zedong

    2017-01-01

    efficient. A dynamic implementation of this approach decomposes the original pseudo-differential operator into a Laplacian, handled using the low-rank approximation of the spectral operator, plus an angular dependent correction factor applied in the space

  6. Regulation of human cerebro-microvascular endothelial baso-lateral adhesion and barrier function by S1P through dual involvement of S1P1 and S1P2 receptors.

    Science.gov (United States)

    Wiltshire, Rachael; Nelson, Vicky; Kho, Dan Ting; Angel, Catherine E; O'Carroll, Simon J; Graham, E Scott

    2016-01-27

    Herein we show that S1P rapidly and acutely reduces the focal adhesion strength and barrier tightness of brain endothelial cells. xCELLigence biosensor technology was used to measure focal adhesion, which was reduced by S1P acutely and this response was mediated through both S1P1 and S1P2 receptors. S1P increased secretion of several pro-inflammatory mediators from brain endothelial cells. However, the magnitude of this response was small in comparison to that mediated by TNFα or IL-1β. Furthermore, S1P did not significantly increase cell-surface expression of any key cell adhesion molecules involved in leukocyte recruitment, included ICAM-1 and VCAM-1. Finally, we reveal that S1P acutely and dynamically regulates microvascular endothelial barrier tightness in a manner consistent with regulated rapid opening followed by closing and strengthening of the barrier. We hypothesise that the role of the S1P receptors in this process is not to cause barrier dysfunction, but is related to controlled opening of the endothelial junctions. This was revealed using real-time measurement of barrier integrity using ECIS ZΘ TEER technology and endothelial viability using xCELLigence technology. Finally, we show that these responses do not occur simply though the pharmacology of a single S1P receptor but involves coordinated action of S1P1 and S1P2 receptors.

  7. Adaptive kernels in approximate filtering of state-space models

    Czech Academy of Sciences Publication Activity Database

    Dedecius, Kamil

    2017-01-01

    Roč. 31, č. 6 (2017), s. 938-952 ISSN 0890-6327 R&D Projects: GA ČR(CZ) GP14-06678P Institutional support: RVO:67985556 Keywords : filtering * nonlinear filters * Bayesian filtering * sequential Monte Carlo * approximate filtering Subject RIV: BB - Applied Statistics, Operational Research OBOR OECD: Statistics and probability Impact factor: 1.708, year: 2016 http://library.utia.cs.cz/separaty/2016/AS/dedecius-0466448.pdf

  8. Detection accuracy of in vitro approximal caries by cone beam computed tomography images

    Energy Technology Data Exchange (ETDEWEB)

    Qu Xingmin, E-mail: quxingmin@bjmu.edu.cn [Department of Oral and Maxillofacial Radiology, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Hai Dian District, Beijing 100081 (China); Li Gang, E-mail: kqgang@bjmu.edu.cn [Department of Oral and Maxillofacial Radiology, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Hai Dian District, Beijing 100081 (China); Zhang Zuyan, E-mail: zhangzy-bj@vip.sina.com [Department of Oral and Maxillofacial Radiology, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Hai Dian District, Beijing 100081 (China); Ma Xuchen, E-mail: kqxcma@bjmu.edu.cn [Department of Oral and Maxillofacial Radiology, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Hai Dian District, Beijing 100081 (China)

    2011-08-15

    Aims: To evaluate the diagnostic accuracy of approximal carious lesions among five CBCT systems and to assess the effect of detector types employed by different CBCT systems on the accuracy of approximal caries diagnosis. Materials and methods: Thirty-nine extracted non-cavitated human permanent teeth were employed in the study. Seven observers evaluated 78 approximal surfaces of the teeth with respect to caries by the images from the following five CBCT systems: (1) NewTom 9000; (2) Accuitomo 3DX; (3) Kodak 9000 3D; (4) ProMax 3D; and (5) DCT PRO, respectively. The lesions were validated by histological examination. The area under receiver operating characteristic (ROC) curve (A{sub z}) was used to evaluate the diagnostic accuracy. Results: Microscopy of approximal surfaces found 47.4% sound, 39.8% enamel and 12.8% dentin lesions. The differences of A{sub z} values among the five CBCT systems were not statistically significant (p = 0.348). No significant difference was found between the two detector types of CBCT systems (p = 0.47). Conclusions: The five CBCT systems employed in the study showed no significant difference in the in vitro approximal caries detection. Neither the detector nor the FOV employed by the CBCT systems has an impact on the detection accuracy of approximal caries.

  9. Detection accuracy of in vitro approximal caries by cone beam computed tomography images

    International Nuclear Information System (INIS)

    Qu Xingmin; Li Gang; Zhang Zuyan; Ma Xuchen

    2011-01-01

    Aims: To evaluate the diagnostic accuracy of approximal carious lesions among five CBCT systems and to assess the effect of detector types employed by different CBCT systems on the accuracy of approximal caries diagnosis. Materials and methods: Thirty-nine extracted non-cavitated human permanent teeth were employed in the study. Seven observers evaluated 78 approximal surfaces of the teeth with respect to caries by the images from the following five CBCT systems: (1) NewTom 9000; (2) Accuitomo 3DX; (3) Kodak 9000 3D; (4) ProMax 3D; and (5) DCT PRO, respectively. The lesions were validated by histological examination. The area under receiver operating characteristic (ROC) curve (A z ) was used to evaluate the diagnostic accuracy. Results: Microscopy of approximal surfaces found 47.4% sound, 39.8% enamel and 12.8% dentin lesions. The differences of A z values among the five CBCT systems were not statistically significant (p = 0.348). No significant difference was found between the two detector types of CBCT systems (p = 0.47). Conclusions: The five CBCT systems employed in the study showed no significant difference in the in vitro approximal caries detection. Neither the detector nor the FOV employed by the CBCT systems has an impact on the detection accuracy of approximal caries.

  10. A thermodynamic approximation of the groundstate of antiferromagnetic Heisenberg spin-1/2 lattices

    NARCIS (Netherlands)

    Tielen, G.I.; Iske, P.L.; Caspers, W.J.; Caspers, W.J.

    1991-01-01

    The exact ground state of finite Heisenberg spin−1/2 lattices isstudied. The coefficients of the so-called Ising configurations contributing to the ground state are approximated by Boltzmann-like expressions. These expressions contain a parameter that may be related to an inverse temperature.

  11. The form of electron-atom excitation amplitudes at high momentum transfers in the Faddeev-Watson approximation

    International Nuclear Information System (INIS)

    Catalan, G.; Roberts, M.J.

    1979-01-01

    A form of the off-shell Coulomb T matrix, which has a well defined on-shell limit, is used in the Faddeev-Watson multiple-scattering expansion for a direct three-body collision process. Using the excitation of atomic hydrogen by electron impact as an example, approximations to the second-order terms, which are valid for high momentum transfers of the incident electron, are derived. It is shown how the resulting asymptotic behaviour of the second-order Faddeev-Watson approximation is related to the high momentum transfer limit of the second Born approximation. The results are generalised to the excitation of more complex atoms. The asymptotic forms of the Faddeev-Watson and Born approximations are compared with other theories and with measurements of differential cross sections and angular correlation parameters for the excitation of H(2p) and He(2 1 P). The results indicate that the Faddeev-Watson approximation converges more rapidly at high momentum transfers than does the Born approximation. (author)

  12. Toxicology and carcinogenesis studies of p,p'-dichlorophenyl sulfone (CAS No. 80-07-9) in F344/N rats and B6C3F1 mice (feed studies).

    Science.gov (United States)

    2001-09-01

    p,pN-Dichlorodiphenyl sulfone is used as a starting material in the production of polysulfones and polyethersulfones and as a component in reactive dyes in the textile industry; it is also a by-product of pesticide production. p,pN-Dichlorodiphenyl sulfone was nominated for study by the National Cancer Institute because of its history of high production and use, the prospect of increased production and use, and the absence of adequate toxicity testing. Male and female F344/N rats and B6C3F1 mice were exposed top,pN-dichlorodiphenyl sulfone (greater than 99% pure)in feed for 14 weeks or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium,cultured Chinese hamster ovary cells, and mouse bone marrow. 14-WEEK STUDY IN RATS: Groups of 10 male and 10 female F344/N rats were fed diets containing 0, 30, 100, 300, 1,000, or 3,000 ppm p,pN-dichlorodiphenyl sulfone (equivalent to average daily doses of approximately 2, 6, 19, 65, or 200 mgp,pN-dichlorodiphenyl sulfone/kg body weight) for 14 weeks. All rats survived until the end of the study. Mean body weights of groups exposed to 300 ppm or greater were significantly less than those of the controls. Liver weights of groups exposed to 100 ppm or greater and kidney weights of 1,000 and 3,000 ppm male rats were significantly greater than those of the controls. Centrilobular hepatocyte hypertrophy of the liver was observed in most male rats exposed to 100 ppm or greater and in all female rats exposed to 300 ppm or greater, and the severities were increased in 300 ppm males and 1,000 and 3,000 ppm males and females. The incidences of nephropathy in 1,000 and 3,000 ppm female rats were significantly increased. Dose-related increases in severity of nephropathy were observed in male rats. 14-WEEK STUDY IN MICE: Groups of 10 male and 10 female B6C3F1 mice were fed diets containing 0, 30, 100, 300, 1,000, or 3,000 ppm p,pN-dichlorodiphenyl sulfone (equivalent to average daily doses of approximately 3.5, 15, 50

  13. [An updated review of 1p36 deletion (monosomy) syndrome].

    Science.gov (United States)

    Bello, Sabina; Rodríguez-Moreno, Antonio

    The Monosomy 1p36 deletion syndrome is part of the group of diseases known as Rare Diseases. The objective of the present work is to review the characteristics of Monosomy 1p36 deletion syndrome. The monosomy 1p36 deletion syndrome phenotype includes: dysmorphic craniofacial features; large anterior fontanelle, unibrow, deep-set eyes, epicanthus, wide nasal root/bridge, mandible hypoplasia, abnormal location of the pinna, philtrum and pointed chin; neurological alterations: seizures and hydrocephalus (in some cases). Cerebral malformations: ventricular hypertrophy, increased subarachnoid space, morphological alterations of corpus callosum, cortical atrophy, delays in myelinisation, periventricular leukomalacia and periventricular heterotopia. These alterations produce intellectual disability and delays in motor growth, communication skills, language, social and adaptive behaviour. It is Hearing and vision impairments are also observed in subjects with this syndrome, as well as alterations of cardiac, endocrine and urinary systems and alterations at skin and skeletal level. Approximately 100 cases have been documented since 1981. This rare disease is the most common subtelomeric-micro-deletion syndrome. In situ hybridization with fluorescence (FISH) and array-comparative genomic hybridization (CGH-array) are at present the two best diagnostic techniques. There is currently no effective medical treatment for this disease. Copyright © 2016 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Rainbows: Mie computations and the Airy approximation.

    Science.gov (United States)

    Wang, R T; van de Hulst, H C

    1991-01-01

    Efficient and accurate computation of the scattered intensity pattern by the Mie formulas is now feasible for size parameters up to x = 50,000 at least, which in visual light means spherical drops with diameters up to 6 mm. We present a method for evaluating the Mie coefficients from the ratios between Riccati-Bessel and Neumann functions of successive order. We probe the applicability of the Airy approximation, which we generalize to rainbows of arbitrary p (number of internal reflections = p - 1), by comparing the Mie and Airy intensity patterns. Millimeter size water drops show a match in all details, including the position and intensity of the supernumerary maxima and the polarization. A fairly good match is still seen for drops of 0.1 mm. A small spread in sizes helps to smooth out irrelevant detail. The dark band between the rainbows is used to test more subtle features. We conclude that this band contains not only externally reflected light (p = 0) but also a sizable contribution f rom the p = 6 and p = 7 rainbows, which shift rapidly with wavelength. The higher the refractive index, the closer both theories agree on the first primary rainbow (p = 2) peak for drop diameters as small as 0.02 mm. This may be useful in supporting experimental work.

  15. Sphingosine 1-phosphate (S1P) suppresses the collagen-induced activation of human platelets via S1P4 receptor.

    Science.gov (United States)

    Onuma, Takashi; Tanabe, Kumiko; Kito, Yuko; Tsujimoto, Masanori; Uematsu, Kodai; Enomoto, Yukiko; Matsushima-Nishiwaki, Rie; Doi, Tomoaki; Nagase, Kiyoshi; Akamatsu, Shigeru; Tokuda, Haruhiko; Ogura, Shinji; Iwama, Toru; Kozawa, Osamu; Iida, Hiroki

    2017-08-01

    Sphingosine 1-phosphate (S1P) is as an extracellular factor that acts as a potent lipid mediator by binding to specific receptors, S1P receptors (S1PRs). However, the precise role of S1P in human platelets that express S1PRs has not yet been fully clarified. We previously reported that heat shock protein 27 (HSP27) is released from human platelets accompanied by its phosphorylation stimulated by collagen. In the present study, we investigated the effect of S1P on the collagen-induced platelet activation. S1P pretreatment markedly attenuated the collagen-induced aggregation. Co-stimulation with S1P and collagen suppressed collagen-induced platelet activation, but the effect was weaker than that of S1P-pretreatment. The collagen-stimulated secretion of platelet-derived growth factor (PDGF)-AB and the soluble CD40 ligand (sCD40L) release were significantly reduced by S1P. In addition, S1P suppressed the collagen-induced release of HSP27 as well as the phosphorylation of HSP27. S1P significantly suppressed the collagen-induced phosphorylation of p38 mitogen-activated protein kinase. S1P increased the levels of GTP-bound Gαi and GTP-bound Gα13 coupled to S1PPR1 and/or S1PR4. CYM50260, a selective S1PR4 agonist, but not SEW2871, a selective S1PR1 agonist, suppressed the collagen-stimulated platelet aggregation, PDGF-AB secretion and sCD40L release. In addition, CYM50260 reduced the release of phosphorylated-HSP27 by collagen as well as the phosphorylation of HSP27. The selective S1PR4 antagonist CYM50358, which failed to affect collagen-induced HSP27 phosphorylation, reversed the S1P-induced attenuation of HSP27 phosphorylation by collagen. These results strongly suggest that S1P inhibits the collagen-induced human platelet activation through S1PR4 but not S1PR1. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Mean-field approximation for spacing distribution functions in classical systems

    Science.gov (United States)

    González, Diego Luis; Pimpinelli, Alberto; Einstein, T. L.

    2012-01-01

    We propose a mean-field method to calculate approximately the spacing distribution functions p(n)(s) in one-dimensional classical many-particle systems. We compare our method with two other commonly used methods, the independent interval approximation and the extended Wigner surmise. In our mean-field approach, p(n)(s) is calculated from a set of Langevin equations, which are decoupled by using a mean-field approximation. We find that in spite of its simplicity, the mean-field approximation provides good results in several systems. We offer many examples illustrating that the three previously mentioned methods give a reasonable description of the statistical behavior of the system. The physical interpretation of each method is also discussed.

  17. Presence of pRI1:

    DEFF Research Database (Denmark)

    Migura, Lourdes Garcia; Hasman, Henrik; Jensen, Lars Bogø

    2009-01-01

    This study focused on the molecular characterization of a small cryptic, mobilizable plasmid (6038 bp) sequenced from an E. faecium 9631160-1 of poultry origin. Sequence analysis of pRI1 revealed seven open reading frames. pRI1 contained an IS 100% identical to ISEfa4. This insertion element...... almost identical to the repA from the pEFNP1 and pKQ10 plasmids from E. faecium was also identified. Presence of the pRI1 replication initiation gene (rep) was analyzed in a panel of 159 E. faecium isolates of human and animal origin from different European countries, of which 60 tested positive...

  18. Sphingosine-1-Phosphate (S1P) Lyase Inhibition Causes Increased Cardiac S1P Levels and Bradycardia in Rats.

    Science.gov (United States)

    Harris, Christopher M; Mittelstadt, Scott; Banfor, Patricia; Bousquet, Peter; Duignan, David B; Gintant, Gary; Hart, Michelle; Kim, Youngjae; Segreti, Jason

    2016-10-01

    Inhibition of the sphingosine-1-phosphate (S1P)-catabolizing enzyme S1P lyase (S1PL) elevates the native ligand of S1P receptors and provides an alternative mechanism for immune suppression to synthetic S1P receptor agonists. S1PL inhibition is reported to preferentially elevate S1P in lymphoid organs. Tissue selectivity could potentially differentiate S1PL inhibitors from S1P receptor agonists, the use of which also results in bradycardia, atrioventricular block, and hypertension. But it is unknown if S1PL inhibition would also modulate cardiac S1P levels or cardiovascular function. The S1PL inhibitor 6-[(2R)-4-(4-benzyl-7-chlorophthalazin-1-yl)-2-methylpiperazin-1-yl]pyridine-3-carbonitrile was used to determine the relationship in rats between drug concentration, S1P levels in select tissues, and circulating lymphocytes. Repeated oral doses of the S1PL inhibitor fully depleted circulating lymphocytes after 3 to 4 days of treatment in rats. Full lymphopenia corresponded to increased levels of S1P of 100- to 1000-fold in lymph nodes, 3-fold in blood (but with no change in plasma), and 9-fold in cardiac tissue. Repeated oral dosing of the S1PL inhibitor in telemeterized, conscious rats resulted in significant bradycardia within 48 hours of drug treatment, comparable in magnitude to the bradycardia induced by 3 mg/kg fingolimod. These results suggest that S1PL inhibition modulates cardiac function and does not provide immune suppression with an improved cardiovascular safety profile over fingolimod in rats. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  19. Boundary Control of Linear Uncertain 1-D Parabolic PDE Using Approximate Dynamic Programming.

    Science.gov (United States)

    Talaei, Behzad; Jagannathan, Sarangapani; Singler, John

    2018-04-01

    This paper develops a near optimal boundary control method for distributed parameter systems governed by uncertain linear 1-D parabolic partial differential equations (PDE) by using approximate dynamic programming. A quadratic surface integral is proposed to express the optimal cost functional for the infinite-dimensional state space. Accordingly, the Hamilton-Jacobi-Bellman (HJB) equation is formulated in the infinite-dimensional domain without using any model reduction. Subsequently, a neural network identifier is developed to estimate the unknown spatially varying coefficient in PDE dynamics. Novel tuning law is proposed to guarantee the boundedness of identifier approximation error in the PDE domain. A radial basis network (RBN) is subsequently proposed to generate an approximate solution for the optimal surface kernel function online. The tuning law for near optimal RBN weights is created, such that the HJB equation error is minimized while the dynamics are identified and closed-loop system remains stable. Ultimate boundedness (UB) of the closed-loop system is verified by using the Lyapunov theory. The performance of the proposed controller is successfully confirmed by simulation on an unstable diffusion-reaction process.

  20. Hierarchical low-rank approximation for high dimensional approximation

    KAUST Repository

    Nouy, Anthony

    2016-01-07

    Tensor methods are among the most prominent tools for the numerical solution of high-dimensional problems where functions of multiple variables have to be approximated. Such high-dimensional approximation problems naturally arise in stochastic analysis and uncertainty quantification. In many practical situations, the approximation of high-dimensional functions is made computationally tractable by using rank-structured approximations. In this talk, we present algorithms for the approximation in hierarchical tensor format using statistical methods. Sparse representations in a given tensor format are obtained with adaptive or convex relaxation methods, with a selection of parameters using crossvalidation methods.

  1. Hierarchical low-rank approximation for high dimensional approximation

    KAUST Repository

    Nouy, Anthony

    2016-01-01

    Tensor methods are among the most prominent tools for the numerical solution of high-dimensional problems where functions of multiple variables have to be approximated. Such high-dimensional approximation problems naturally arise in stochastic analysis and uncertainty quantification. In many practical situations, the approximation of high-dimensional functions is made computationally tractable by using rank-structured approximations. In this talk, we present algorithms for the approximation in hierarchical tensor format using statistical methods. Sparse representations in a given tensor format are obtained with adaptive or convex relaxation methods, with a selection of parameters using crossvalidation methods.

  2. Sphingosine 1-phosphate (S1P)/S1P receptor 1 signaling regulates receptor activator of NF-κB ligand (RANKL) expression in rheumatoid arthritis

    International Nuclear Information System (INIS)

    Takeshita, Harunori; Kitano, Masayasu; Iwasaki, Tsuyoshi; Kitano, Sachie; Tsunemi, Sachi; Sato, Chieri; Sekiguchi, Masahiro; Azuma, Naoto; Miyazawa, Keiji; Hla, Timothy; Sano, Hajime

    2012-01-01

    Highlights: ► MH7A cells and CD4 + T cells expressed S1P1 and RANKL. ► S1P increased RANKL expression in MH7A cells and CD4 + T cells. ► The effect of S1P in MH7A cells was inhibited by specific Gi/Go inhibitors. -- Abstract: Sphingosine 1-phosphate (S1P)/S1P receptor 1 (S1P1) signaling plays an important role in synovial cell proliferation and inflammatory gene expression by rheumatoid arthritis (RA) synoviocytes. The purpose of this study is to clarify the role of S1P/S1P1 signaling in the expression of receptor activator of NF-κB ligand (RANKL) in RA synoviocytes and CD4 + T cells. We demonstrated MH7A cells, a human RA synovial cell line, and CD4 + T cells expressed S1P1 and RANKL. Surprisingly, S1P increased RANKL expression in MH7A cells and CD4 + T cells in a dose-dependent manner. Moreover, S1P enhanced RANKL expression induced by stimulation with TNF-α in MH7A cells and CD4 + T cells. These effects of S1P in MH7A cells were inhibited by pretreatment with PTX, a specific Gi/Go inhibitor. These findings suggest that S1P/S1P1 signaling may play an important role in RANKL expression by MH7A cells and CD4 + T cells. S1P/S1P1 signaling of RA synoviocytes is closely connected with synovial hyperplasia, inflammation, and RANKL-induced osteoclastogenesis in RA. Thus, regulation of S1P/S1P1 signaling may become a novel therapeutic target for RA.

  3. Sphingosine 1-phosphate (S1P)/S1P receptor 1 signaling regulates receptor activator of NF-{kappa}B ligand (RANKL) expression in rheumatoid arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Takeshita, Harunori [Division of Rheumatology, Department of Internal Medicine, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501 (Japan); Kitano, Masayasu, E-mail: mkitano6@hyo-med.ac.jp [Division of Rheumatology, Department of Internal Medicine, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501 (Japan); Iwasaki, Tsuyoshi [Department of Pharmacy, Hyogo University of Health Sciences, 1-3-6 Minatojima Kobe, Hyogo 650-8530 (Japan); Kitano, Sachie; Tsunemi, Sachi; Sato, Chieri; Sekiguchi, Masahiro; Azuma, Naoto [Division of Rheumatology, Department of Internal Medicine, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501 (Japan); Miyazawa, Keiji [Discovery Research III, Research and Development, Kissei Pharmaceutical Company, 4365-1 Hodakakashiwara, Azumino, Nagano 399-8304 (Japan); Hla, Timothy [Center for Vascular Biology, Department of Pathology and Laboratory Medicine, Weill Medical College of Cornell University, 1300 York Avenue, Box 69, NY 10065 (United States); Sano, Hajime [Division of Rheumatology, Department of Internal Medicine, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501 (Japan)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer MH7A cells and CD4{sup +} T cells expressed S1P1 and RANKL. Black-Right-Pointing-Pointer S1P increased RANKL expression in MH7A cells and CD4{sup +} T cells. Black-Right-Pointing-Pointer The effect of S1P in MH7A cells was inhibited by specific Gi/Go inhibitors. -- Abstract: Sphingosine 1-phosphate (S1P)/S1P receptor 1 (S1P1) signaling plays an important role in synovial cell proliferation and inflammatory gene expression by rheumatoid arthritis (RA) synoviocytes. The purpose of this study is to clarify the role of S1P/S1P1 signaling in the expression of receptor activator of NF-{kappa}B ligand (RANKL) in RA synoviocytes and CD4{sup +} T cells. We demonstrated MH7A cells, a human RA synovial cell line, and CD4{sup +} T cells expressed S1P1 and RANKL. Surprisingly, S1P increased RANKL expression in MH7A cells and CD4{sup +} T cells in a dose-dependent manner. Moreover, S1P enhanced RANKL expression induced by stimulation with TNF-{alpha} in MH7A cells and CD4{sup +} T cells. These effects of S1P in MH7A cells were inhibited by pretreatment with PTX, a specific Gi/Go inhibitor. These findings suggest that S1P/S1P1 signaling may play an important role in RANKL expression by MH7A cells and CD4{sup +} T cells. S1P/S1P1 signaling of RA synoviocytes is closely connected with synovial hyperplasia, inflammation, and RANKL-induced osteoclastogenesis in RA. Thus, regulation of S1P/S1P1 signaling may become a novel therapeutic target for RA.

  4. Continuum orbital approximations in weak-coupling theories for inelastic electron scattering

    International Nuclear Information System (INIS)

    Peek, J.M.; Mann, J.B.

    1977-01-01

    Two approximations, motivated by heavy-particle scattering theory, are tested for weak-coupling electron-atom (ion) inelastic scattering theory. They consist of replacing the one-electron scattering orbitals by their Langer uniform approximations and the use of an average trajectory approximation which entirely avoids the necessity for generating continuum orbitals. Numerical tests for a dipole-allowed and a dipole-forbidden event, based on Coulomb-Born theory with exchange neglected, reveal the error trends. It is concluded that the uniform approximation gives a satisfactory prediction for traditional weak-coupling theories while the average approximation should be limited to collision energies exceeding at least twice the threshold energy. The accuracy for both approximations is higher for positive ions than for neutral targets. Partial-wave collision-strength data indicate that greater care should be exercised in using these approximations to predict quantities differential in the scattering angle. An application to the 2s 2 S-2p 2 P transition in Ne VIII is presented

  5. Bound-state problem in the light-front Tamm-Dancoff approximation: Numerical study in 1+1 dimensions

    International Nuclear Information System (INIS)

    Harindranath, A.; Perry, R.J.; Shigemitsu, J.

    1992-01-01

    Numerical solutions to the two-fermion bound-state problem in the (1+1)-dimensional Yukawa model are presented within the lowest-order light-front Tamm-Dancoff approximation (i.e., keeping only two-fermion and two-fermion--one-boson sectors). Our motivation is twofold. First, we want to understand the dynamics of the model from the very-weak-coupling domain, where the system is governed by nonrelativistic dynamics, to moderate and strong-coupling domains where retardation and self-energy effects become important. Second, we want to develop techniques for solving coupled Tamm-Dancoff integral equations, in particular, methods that can be generalized to higher-order Tamm-Dancoff approximations. To achieve the first goal we first simplify the problem considerably (from a numerical point of view) by the explicit elimination of the higher Fock-space sector. The resulting integral equation, whose kernel depends upon the invariant mass of the state, is solved for the coupling constant, for a given set of the invariant mass and fermion and boson mass parameters. To achieve the second goal we solve the coupled set of equations using both basis functions and direct-discretization techniques. Results from these more general techniques are compared with the explicit-elimination method

  6. Measurement of the $\\chi_b(3P)$ mass and of the relative rate of $\\chi_{b1}(1P)$ and $\\chi_{b2}(1P)$ production

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; van den Brand, Johannes; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Busetto, Giovanni; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cojocariu, Lucian; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Gavrilov, Gennadii; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, V.V.; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Lespinasse, Mickael; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lu, Haiting; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Roa Romero, Diego; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wu, Suzhi; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2014-10-14

    The production of $\\chi_b$ mesons in proton-proton collisions is studied using a data sample collected by the LHCb detector, at centre-of-mass energies of $\\sqrt{s}=7$ and $8$ TeV and corresponding to an integrated luminosity of 3.0 fb$^{-1}$. The $\\chi_b$ mesons are identified through their decays to $\\Upsilon(1S)\\gamma$ and $\\Upsilon(2S)\\gamma$ using photons that converted to $e^+e^-$ pairs in the detector. The $\\chi_b(3P)$ meson mass, and the relative prompt production rate of $\\chi_{b1}(1P)$ and $\\chi_{b2}(1P)$ mesons as a function of the $\\Upsilon(1S)$ transverse momentum in the $\\chi_b$ rapidity range 2.0< $y$<4.5, are measured. Assuming a mass splitting between the $\\chi_{b1}(3P)$ and the $\\chi_{b2}(3P)$ states of 10.5 MeV/$c^2$, the mass of the $\\chi_{b1}(3P)$ meson is \\begin{equation*} m(\\chi_{b1}(3P))= 10515.7^{+2.2}_{-3.9}(stat) ^{+1.5}_{-2.1}(syst) MeV/c^2. \\end{equation*}

  7. Inclusive and exclusive cross sections for multiple ionization by fast, highly charged ions in the independent-electron approximation

    International Nuclear Information System (INIS)

    Ben-Itzhak, I.; Gray, T.J.; Legg, J.C.; McGuire, J.H.

    1988-01-01

    Cross sections for the ionization of n of N electrons with equal single-electron ionization probability P are considered. When both N and the projectile charge q are large, the cross sections for single and double ionization are both found to be approximately linear in q at 1 MeVamu. The ratio of double-to-single-ionization cross sections is independent of q. Moreover, first-order perturbation theory for the single-electron ionization probability P, which varies as q 2 , is found to be applicable due to the damping of contributions with large P caused by factors of (1-P)/sup N/ - /sup n/. For large P there are differences between the inclusive probability P and the probability NP commonly used for a target with N electrons. Both of these probabilities differ significantly from the exclusive probability NP(1-P)/sup N/ -1 for the ionization of only one electron. For large N and large q, the exclusive ionization probabilities for removing exactly n of the N electrons tend to be concentrated in somewhat separate ranges of impact parameters b, defining impact-parameter ''windows.'' The windows which we obtain using the quantum-mechanical semiclassical-Coulomb-approximation (SCA) probabilities are similar to those using classical Monte Carlo calculations. Model calculations, based on analytic fits to the SCA probabilities, are used to obtain approximate analytic expressions for single- and double-ionization cross sections and for the impact-parameter windows

  8. TRIMARAN: a three dimensional multigroup P1 Monte Carlo code for criticality studies

    International Nuclear Information System (INIS)

    Ermumcu, G.; Gonnord, J.; Nimal, J.C.

    1980-01-01

    TRIMARAN is developed for safety analysis of nuclear components containing fissionable materials: shipping casks, storage and cooling pools, manufacture and reprocessing plants. It solves the transport equation by Monte Carlo method, in general three dimensional geometry with multigroup P1 approximation. A special representation of cross sections and numbers has been developed in order to reduce considerably the computing cost and allow this three dimensional code to compete with standard numerical program used in parametric studies

  9. TRIMARAN: a three dimensional multigroup P1 Monte Carlo code for criticallity studies

    International Nuclear Information System (INIS)

    Ermuncu, G.; Gonnord, J.; Nimal, J.C.

    1980-04-01

    TRIMARAN is developed for safety analysis of nuclar components containing fissionnable materials: shipping casks, storage and cooling pools, manufacture and reprocessing plants. It solves the transport equation by Monte Carlo method in general three dimensional geometry with multigroup P1 approximation. A special representation of cross sections and numbers has been developed in order to reduce considerably the computing cost and allow this three dimensional code to compete with standard numerical program used in parametric studies

  10. A Genome-wide Association Study Provides Evidence of Sex-specific Involvement of Chr1p35.1 (ZSCAN20-TLR12P and Chr8p23.1 (HMGB1P46 With Diabetic Neuropathic Pain

    Directory of Open Access Journals (Sweden)

    Weihua Meng

    2015-10-01

    Full Text Available Neuropathic pain is defined as pain arising as a direct consequence of a lesion or a disease affecting the somatosensory system and it affects around 1 in 4 diabetic patients in the UK. The purpose of this genome-wide association study (GWAS was to identify genetic contributors to this disorder. Cases of neuropathic pain were defined as diabetic patients with a multiple prescription history of at least one of five drugs specifically indicated for the treatment of neuropathic pain. Controls were diabetic individuals who were not prescribed any of these drugs, nor amitriptyline, carbamazepine, or nortriptyline. Overall, 961 diabetic neuropathic pain cases and 3260 diabetic controls in the Genetics of Diabetes Audit and Research Tayside (GoDARTS cohort were identified. We found a cluster in the Chr1p35.1 (ZSCAN20-TLR12P with a lowest P value of 2.74 × 10−7 at rs71647933 in females and a cluster in the Chr8p23.1, next to HMGB1P46 with a lowest P value of 8.02 × 10−7 at rs6986153 in males. Sex-specific narrow sense heritability was higher in males (30.0% than in females (14.7%. This GWAS on diabetic neuropathic pain provides evidence for the sex-specific involvement of Chr1p35.1 (ZSCAN20-TLR12P and Chr8p23.1 (HMGB1P46 with the disorder, indicating the need for further research.

  11. Role of Pex21p for Piggyback Import of Gpd1p and Pnc1p into Peroxisomes of Saccharomyces cerevisiae*

    Science.gov (United States)

    Effelsberg, Daniel; Cruz-Zaragoza, Luis Daniel; Tonillo, Jason; Schliebs, Wolfgang; Erdmann, Ralf

    2015-01-01

    Proteins designated for peroxisomal protein import harbor one of two common peroxisomal targeting signals (PTS). In the yeast Saccharomyces cerevisiae, the oleate-induced PTS2-dependent import of the thiolase Fox3p into peroxisomes is conducted by the soluble import receptor Pex7p in cooperation with the auxiliary Pex18p, one of two supposedly redundant PTS2 co-receptors. Here, we report on a novel function for the co-receptor Pex21p, which cannot be fulfilled by Pex18p. The data establish Pex21p as a general co-receptor in PTS2-dependent protein import, whereas Pex18p is especially important for oleate-induced import of PTS2 proteins. The glycerol-producing PTS2 protein glycerol-3-phosphate dehydrogenase Gpd1p shows a tripartite localization in peroxisomes, in the cytosol, and in the nucleus under osmotic stress conditions. We show the following: (i) Pex21p is required for peroxisomal import of Gpd1p as well as a key enzyme of the NAD+ salvage pathway, Pnc1p; (ii) Pnc1p, a nicotinamidase without functional PTS2, is co-imported into peroxisomes by piggyback transport via Gpd1p. Moreover, the specific transport of these two enzymes into peroxisomes suggests a novel regulatory role for peroxisomes under various stress conditions. PMID:26276932

  12. Coherent-potential approximation for the lattice vibrations of mixed III-V crystals

    International Nuclear Information System (INIS)

    Kleinert, P.

    1984-01-01

    The coherent-potential approximation (CPA) is applied to the lattice dynamics of some III-V mixed crystals. The calculations are based on an eleven-parameter rigid-ion model (RIM 11). Explicit results are reported for the one-mode system In/sub 1-c/Ga/sub c/P and the two mixed-mode crystals In/sub 1-c/Ga/sub c/Sb and GaSb/sub 1-c/As/sub c/. Both, the reflectivity spectra and the composition dependence of vibrations at the GAMMA and X points are compared with existing experimental data. Force-constant changes are considered by the virtual-crystal approximation (VCA). The CPA theory is uniquely successful for III-V mixed-mode systems, which appear to switch from one-mode to two-mode behaviour. (author)

  13. Proteomic characterization of plasmid pLA1 for biodegradation of polycyclic aromatic hydrocarbons in the marine bacterium, Novosphingobium pentaromativorans US6-1.

    Directory of Open Access Journals (Sweden)

    Sung Ho Yun

    Full Text Available Novosphingobium pentaromativorans US6-1 is a halophilic marine bacterium able to degrade polycyclic aromatic hydrocarbons (PAHs. Genome sequence analysis revealed that the large plasmid pLA1 present in N. pentaromativorans US6-1 consists of 199 ORFs and possess putative biodegradation genes that may be involved in PAH degradation. 1-DE/LC-MS/MS analysis of N. pentaromativorans US6-1 cultured in the presence of different PAHs and monocyclic aromatic hydrocarbons (MAHs identified approximately 1,000 and 1,400 proteins, respectively. Up-regulated biodegradation enzymes, including those belonging to pLA1, were quantitatively compared. Among the PAHs, phenanthrene induced the strongest up-regulation of extradiol cleavage pathway enzymes such as ring-hydroxylating dioxygenase, putative biphenyl-2,3-diol 1,2-dioxygenase, and catechol 2,3-dioxygenase in pLA1. These enzymes lead the initial step of the lower catabolic pathway of aromatic hydrocarbons through the extradiol cleavage pathway and participate in the attack of PAH ring cleavage, respectively. However, N. pentaromativorans US6-1 cultured with p-hydroxybenzoate induced activation of another extradiol cleavage pathway, the protocatechuate 4,5-dioxygenase pathway, that originated from chromosomal genes. These results suggest that N. pentaromativorans US6-1 utilizes two different extradiol pathways and plasmid pLA1 might play a key role in the biodegradation of PAH in N. pentaromativorans US6-1.

  14. S1P lyase in thymic perivascular spaces promotes egress of mature thymocytes via up-regulation of S1P receptor 1.

    Science.gov (United States)

    Maeda, Yasuhiro; Yagi, Hideki; Takemoto, Kana; Utsumi, Hiroyuki; Fukunari, Atsushi; Sugahara, Kunio; Masuko, Takashi; Chiba, Kenji

    2014-05-01

    Sphingosine 1-phosphate (S1P) and S1P receptor 1 (S1P1) play an important role in the egress of mature CD4 or CD8 single-positive (SP) thymocytes from the thymus. Fingolimod hydrochloride (FTY720), an S1P1 functional antagonist, induced significant accumulation of CD62L(high)CD69(low) mature SP thymocytes in the thymic medulla. Immunohistochemical staining using anti-S1P1 antibody revealed that S1P1 is predominantly expressed on thymocytes in the thymic medulla and is strongly down-regulated even at 3h after FTY720 administration. 2-Acetyl-4-tetrahydroxybutylimidazole (THI), an S1P lyase inhibitor, also induced accumulation of mature SP thymocytes in the thymic medulla with an enlargement of the perivascular spaces (PVS). At 6h after THI administration, S1P1-expressing thymocytes reduced partially as if to form clusters and hardly existed in the proximity of CD31-expressing blood vessels in the thymic medulla, suggesting S1P lyase expression in the cells constructing thymic medullary PVS. To determine the cells expressing S1P lyase in the thymus, we newly established a mAb (YK19-2) specific for mouse S1P lyase. Immunohistochemical staining with YK19-2 revealed that S1P lyase is predominantly expressed in non-lymphoid thymic stromal cells in the thymic medulla. In the thymic medullary PVS, S1P lyase was expressed in ER-TR7-positive cells (reticular fibroblasts and pericytes) and CD31-positive vascular endothelial cells. Our findings suggest that S1P lyase expressed in the thymic medullary PVS keeps the tissue S1P concentration low around the vessels and promotes thymic egress via up-regulation of S1P1.

  15. MPN-1 : A computation module for the solution of transport equation in multiregions by P sub(N) method

    International Nuclear Information System (INIS)

    Yamaguchi, M.; Maiorino, J.R.

    1981-11-01

    The MPN-1, which is a computer program made in FORTRAN IV is described. The MPN-1 uses P sub(N) method to solve the one-speed, anisotropic linear steady-state transport equation in non-multiplying multiregions, slab geometry. The MPN-1 allows a maximum number of 12 regions, and maximum order of approximation, N=15. Besides, the anisotropic scattering is treated by an expansion in Legendre polynomial up to maximum degree of L=15. The boundary conditions used are: I) free surface; II) isotropic incidence; III) cosine incidence (aμ sup(α1 + bμ sup(α2) + cμ sup(α3)); IV) monodirectional incidence (delta function); V) total reflection. The required input are: order of approximation P sub(N'), average number of secondary particles in each region, external sources, thickness of each region, coefficients in a Legendre expansion of the transfer function in each region, and type of boundary conditions at the boundaries. The output are: albedo, transmission factor, disadvantage factor, total and angular fluxes and current. (Author) [pt

  16. Role of sphingosine 1-phosphate (S1P and effects of fingolimod, an S1P receptor 1 functional antagonist in lymphocyte circulation and autoimmune diseases

    Directory of Open Access Journals (Sweden)

    Kenji Chiba

    2014-11-01

    Full Text Available Sphingosine 1-phosphate (S1P, a multi-functional phospholipid mediator, is generated from sphingosine by sphingosine kinases and binds to five known G protein-coupled S1P receptors (S1P1, S1P2, S1P3, S1P4, and S1P5. It is widely accepted that S1P receptor 1 (S1P1 plays an essential role in lymphocyte egress from the secondary lymphoid organs (SLO and thymus, because lymphocyte egress from these organs to periphery is at extremely low levels in mice lacking lymphocytic S1P1. Fingolimod hydrochloride (FTY720 is a first-in-class, orally active S1P1 functional antagonist which was discovered by chemical modification of a natural product, myriocin. Since FTY720 has a structure closely related to sphingosine, the phosphorylated FTY720 (FTY720-P is converted by sphingosine kinases and binds 4 types of S1P receptors. FTY720-P strongly induces down-regulation of S1P1 by internalization and degradation of this receptor and acts as a functional antagonist at S1P1. Consequently, FTY720 inhibits S1P1-dependent lymphocyte egress from the SLO and thymus to reduce circulating lymphocytes including autoreactive Th17 cells, and is highly effective in experimental autoimmune encephalomyelitis (EAE, an animal model of multiple sclerosis (MS. In relapsing remitting MS patients, oral FTY720 shows a superior efficacy when compared to intramuscular interferon-β-1a. Based on these data, it is presumed that modulation of the S1P-S1P1 axis provides an effective therapy for autoimmune diseases including MS.

  17. SIAH1-induced p34SEI-1 polyubiquitination/degradation mediates p53 preferential vitamin C cytotoxicity.

    Science.gov (United States)

    Lee, Soonduck; Kim, Jinsun; Jung, Samil; Li, Chengping; Yang, Young; Kim, Keun Il; Lim, Jong-Seok; Kim, Yonghwan; Cheon, Choong-Il; Lee, Myeong-Sok

    2015-03-01

    Vitamin C is considered as an important anticancer therapeutic agent although this view is debatable. In this study, we introduce a physiological mechanism demonstrating how vitamin C exerts anticancer activity that induces cell cycle arrest and apoptosis. Our previous and current data reveal that p53 tumor suppressor is the prerequisite factor for stronger anticancer effects of vitamin C. In addition, vitamin C-mediated cancer cell cytotoxicity appears to be achieved at least partly through the downregulation of the p34SEI-1 oncoprotein. Our previous study showed that p34SEI-1 increases the survival of various types of cancer cells by inhibiting their apoptosis. Present data suggest that vitamin C treatment decreases the p34SEI-1 expression at the protein level and therefore alleviates its anti-apoptotic activity. Of note, SIAH1, E3 ubiquitin ligase, appears to be responsible for the p34SEI-1 polyubiquitination and its subsequent degradation, which is dependent on p53. In summary, vitamin C increases cancer cell death by inducing SIAH1-mediated polyubiquitination/degradation of the p34SEI-1 oncoprotein in a p53-dependent manner.

  18. Role of Pex21p for Piggyback Import of Gpd1p and Pnc1p into Peroxisomes of Saccharomyces cerevisiae.

    Science.gov (United States)

    Effelsberg, Daniel; Cruz-Zaragoza, Luis Daniel; Tonillo, Jason; Schliebs, Wolfgang; Erdmann, Ralf

    2015-10-16

    Proteins designated for peroxisomal protein import harbor one of two common peroxisomal targeting signals (PTS). In the yeast Saccharomyces cerevisiae, the oleate-induced PTS2-dependent import of the thiolase Fox3p into peroxisomes is conducted by the soluble import receptor Pex7p in cooperation with the auxiliary Pex18p, one of two supposedly redundant PTS2 co-receptors. Here, we report on a novel function for the co-receptor Pex21p, which cannot be fulfilled by Pex18p. The data establish Pex21p as a general co-receptor in PTS2-dependent protein import, whereas Pex18p is especially important for oleate-induced import of PTS2 proteins. The glycerol-producing PTS2 protein glycerol-3-phosphate dehydrogenase Gpd1p shows a tripartite localization in peroxisomes, in the cytosol, and in the nucleus under osmotic stress conditions. We show the following: (i) Pex21p is required for peroxisomal import of Gpd1p as well as a key enzyme of the NAD(+) salvage pathway, Pnc1p; (ii) Pnc1p, a nicotinamidase without functional PTS2, is co-imported into peroxisomes by piggyback transport via Gpd1p. Moreover, the specific transport of these two enzymes into peroxisomes suggests a novel regulatory role for peroxisomes under various stress conditions. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Pade approximants and the calculation of effective interactions

    International Nuclear Information System (INIS)

    Schucan, T.H.

    1975-01-01

    It is known that the series expansion of the effective interaction in nuclei diverges in practical applications due to the occurrence of low lying collective states. An approximation scheme which can be used to overcome the difficulties connected with this divergence is reviewed and it is shown that a continued fraction expansion can be used to calculate the eigenstate that has the larger overlap with the model space. An extension of this method is obtained by using Pade approximants (P.A.) which are then applied to the effective interaction, and to related matrices and matrix elements. Mathematical properties of the P.A. are discussed in light of these applications. 7 figures

  20. Random phase approximations for the screening function in high Tc superconductors

    International Nuclear Information System (INIS)

    Lopez-Aguilar, F.; Costa-Quintana, J.; Sanchez, A.; Puig, T.; Aurell, M.T.; Martinez, L.M.; Munoz, J.S.

    1990-01-01

    This paper reports on the electronic transferences from the CuO 2 sheets toward the CuO 3 linear chain, which locate electrons in the orbitals p y /p z of O4/O1 and d z 2 -y 2 of Cu1, and holes in the orbitals d x 2 -y 2 - P z /p y of Cu2 - P2/O3. These holes states present large interatomic overlapping. In this paper, we determine the screening function within the random phase approximation applied to the high-T c superconductors. This screening function is vanishing for determined values of the frequency which correspond to renormalized plasmon frequencies. These frequencies depends on the band parameters and their knowledge is essential for determining the self energy. This self energy is deduced and it contain independent terms for each of the channels for the localization

  1. Choosing conditions of liquid-phase epitaxy of Insub(1-x)Gasub(x)P solid solutions by statistical methods of experiment planning

    International Nuclear Information System (INIS)

    Batyrev, N.I.; Vigdorovich, V.N.; Selin, A.A.

    1978-01-01

    Insub(1-x)Gasub(x)P(x approximately 0.7) solid solution layers obtained with the help of the phase diagram of the In-InP-GaP system have been studied using statistical methods of experiment planning. The liquidus, baric and solidus surfaces have been plotted for the In-InP-GaP ternary system (In content from 85 to 100 mol.%). Analysis of the results obtained makes it possible to determine the optimum compositions of the melt (x=0.67-0.74) and building-up temperatures (800-850 deg) to obtain epitaxyal Insub(1-x)Gasub(x)P layers

  2. CdS{sub x}Te{sub 1-x} ternary semiconductors band gaps calculation using ground state and GW approximations

    Energy Technology Data Exchange (ETDEWEB)

    Kheloufi, Nawal; Bouzid, Abderrazak, E-mail: a_bouzid34@hotmail.com

    2016-06-25

    We present band gap calculations of zinc-blende ternary CdS{sub x}Te{sub 1-x} semiconductors within the standard DFT and quasiparticle calculations employing pseudopotential method. The DFT, the local density approximation (LDA) and the Generalized Gradient Approximation (GGA) based calculations have given very poor results compared to experimental data. The quasiparticle calculations have been investigated via the one-shot GW approximation. The present paper discuses and confirms the effect of inclusion of the semicore states in the cadmium (Cd) pseudopotential. The obtained GW quasiparticle band gap using Cd{sup +20} pseudopotential has been improved compared to the obtained results from the available pseudopotential without the treatment of semicore states. Our DFT and quasiparticle band gap results are discussed and compared to the available theoretical calculations and experimental data. - Graphical abstract: Band gaps improvement concerning the binary and ternary alloys using the GW approximation and Cd{sup 20+} pseudopotential with others levels of approximations (the LDA and GGA approximation employing the Cd{sup 12+} and the LDA within Cd{sup 20+} pseudopotential). - Highlights: • The direct Γ- Γ and indirect Γ- X and Γ- L bands gaps show a nonlinear behavior when S content is enhanced. • The quasiparticle band gap result for the investigated semiconductors is improved using the GW approximation. • All CdS{sub x}Te{sub 1-x} compounds in all compositions range from 0 to 1 are direct band gap semiconductors.

  3. Trends with coverage and pH in Stark tuning rates for CO on Pt(1 1 1) electrodes

    International Nuclear Information System (INIS)

    Uddin, Jamal; Anderson, Alfred B.

    2013-01-01

    The general understanding of so-called electrochemical Stark tuning rates, that is, the potential dependence of vibrational frequency of CO adsorbed on Pt(1 1 1), has developed over the past thirty years in terms of two semiempirical models. The first is the Fermi level shift model used in non-self-consistent-field one-electron molecular orbital theory. This approach has provided qualitative understanding in terms of Fermi level-dependent variations in σ and π orbital bonding between CO and the electrode surface atoms. The second is the use of self-consistent-field theory with surface charging to create adjustable electric fields. Adsorbed CO then reacts to the field in a classical Stark effect with some small uncharacterized Fermi level shift superimposed. It is now possible, using two-dimensional density functional theory, including electrolyte polarization from surface charging, and the dielectric continuum to approximate solvation energy, to calculate the tuning rate in response to shifts in the Fermi level and electrode potential caused by changing the surface charge density. Here we apply this first principles method to calculate trends in the tuning rate for CO adsorbed on 1-fold Pt(1 1 1) sites with changes in CO(ads) coverage and with changes in electrolyte pH. The tuning rate is calculated to decrease as the coverage is increased and, for high coverage, to increase as the pH is increased. These trends are shown to be in qualitative agreement with the very little existing experimental data for these trends

  4. APPROX, 1-D and 2-D Function Approximation by Polynomials, Splines, Finite Elements Method

    International Nuclear Information System (INIS)

    Tollander, Bengt

    1975-01-01

    1 - Nature of physical problem solved: Approximates one- and two- dimensional functions using different forms of the approximating function, as polynomials, rational functions, Splines and (or) the finite element method. Different kinds of transformations of the dependent and (or) the independent variables can easily be made by data cards using a FORTRAN-like language. 2 - Method of solution: Approximations by polynomials, Splines and (or) the finite element method are made in L2 norm using the least square method by which the answer is directly given. For rational functions in one dimension the result given in L(infinite) norm is achieved by iterations moving the zero points of the error curve. For rational functions in two dimensions, the norm is L2 and the result is achieved by iteratively changing the coefficients of the denominator and then solving the coefficients of the numerator by the least square method. The transformation of the dependent and (or) independent variables is made by compiling the given transform data card(s) to an array of integers from which the transformation can be made

  5. Sphingosine kinase/sphingosine 1-phosphate (S1P)/S1P receptor axis is involved in liver fibrosis-associated angiogenesis.

    Science.gov (United States)

    Yang, Le; Yue, Shi; Yang, Lin; Liu, Xin; Han, Zhen; Zhang, Yuanyuan; Li, Liying

    2013-07-01

    Sphingosine kinase (SphK)/sphingosine 1-phosphate (S1P)/S1P receptor (S1PR) axis is involved in multiple biological processes, including liver fibrosis. Angiogenesis is an important pathophysiological process closely associated with liver fibrosis; however, the functional role of SphK/S1P/S1PR in this process remains incompletely defined. Bile duct ligation or carbon tetrachloride was used to induce liver fibrosis in mice. Human fibrotic samples were obtained from livers of patients undergoing liver transplantation. S1P levels in the liver were examined by HPLC. Expression of angiogenic markers, including angiopoietin 1, CD31, vascular cell adhesion molecule-1, and von Willebrand factor, was characterized by immunofluorescence, real-time RT-PCR, and Western blot in the fibrotic liver and primary mouse hepatic stellate cells (HSCs). SphK inhibitor (SKI) or S1PR antagonists were administered intraperitoneally in mice. S1P levels in the liver were closely correlated with mRNA expression of angiogenic markers. Ang1 is expressed in activated HSCs of the fibrotic liver and in primary HSCs. In HSCs, by using specific antagonists or siRNAs, we demonstrated S1P stimulation induced Ang1 expression via S1PR1 and S1PR3. In vivo, S1P reduction by SKI inhibited angiogenesis in fibrotic mice. Furthermore, S1PR1/3 antagonist significantly blocked upregulation of angiogenic markers in the injured liver, and attenuated the extent of liver fibrosis, while S1PR2 antagonist had no effect on angiogenesis, supporting the key role of S1PR1 and S1PR3 in angiogenesis underlying liver fibrosis process. SphK1/S1P/S1PR1/3 axis plays a crucial role in the angiogenic process required for fibrosis development, which may represent an effective therapeutic strategy for liver fibrosis. Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  6. Approximate kernel competitive learning.

    Science.gov (United States)

    Wu, Jian-Sheng; Zheng, Wei-Shi; Lai, Jian-Huang

    2015-03-01

    Kernel competitive learning has been successfully used to achieve robust clustering. However, kernel competitive learning (KCL) is not scalable for large scale data processing, because (1) it has to calculate and store the full kernel matrix that is too large to be calculated and kept in the memory and (2) it cannot be computed in parallel. In this paper we develop a framework of approximate kernel competitive learning for processing large scale dataset. The proposed framework consists of two parts. First, it derives an approximate kernel competitive learning (AKCL), which learns kernel competitive learning in a subspace via sampling. We provide solid theoretical analysis on why the proposed approximation modelling would work for kernel competitive learning, and furthermore, we show that the computational complexity of AKCL is largely reduced. Second, we propose a pseudo-parallelled approximate kernel competitive learning (PAKCL) based on a set-based kernel competitive learning strategy, which overcomes the obstacle of using parallel programming in kernel competitive learning and significantly accelerates the approximate kernel competitive learning for large scale clustering. The empirical evaluation on publicly available datasets shows that the proposed AKCL and PAKCL can perform comparably as KCL, with a large reduction on computational cost. Also, the proposed methods achieve more effective clustering performance in terms of clustering precision against related approximate clustering approaches. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Mcm1p binding sites in ARG1 positively regulate Gcn4p binding and SWI/SNF recruitment

    OpenAIRE

    Yoon, Sungpil; Hinnebusch, Alan G.

    2009-01-01

    Transcription of the arginine biosynthetic gene ARG1 is activated by Gcn4p, a transcription factor induced by starvation for any amino acid. Previously we showed that Gcn4p binding stimulates the recruitment of Mcm1p and co-activator SWI/SNF to ARG1 in cells via Gcn4p induction through amino acid starvation. Here we report that Gcn4p binding is reduced by point mutations of the Mcm1p binding site and increased by overexpression of Mcm1p. This result suggests that Mcm1p plays a positive role i...

  8. A new approximation of Fermi-Dirac integrals of order 1/2 for degenerate semiconductor devices

    Science.gov (United States)

    AlQurashi, Ahmed; Selvakumar, C. R.

    2018-06-01

    There had been tremendous growth in the field of Integrated circuits (ICs) in the past fifty years. Scaling laws mandated both lateral and vertical dimensions to be reduced and a steady increase in doping densities. Most of the modern semiconductor devices have invariably heavily doped regions where Fermi-Dirac Integrals are required. Several attempts have been devoted to developing analytical approximations for Fermi-Dirac Integrals since numerical computations of Fermi-Dirac Integrals are difficult to use in semiconductor devices, although there are several highly accurate tabulated functions available. Most of these analytical expressions are not sufficiently suitable to be employed in semiconductor device applications due to their poor accuracy, the requirement of complicated calculations, and difficulties in differentiating and integrating. A new approximation has been developed for the Fermi-Dirac integrals of the order 1/2 by using Prony's method and discussed in this paper. The approximation is accurate enough (Mean Absolute Error (MAE) = 0.38%) and easy enough to be used in semiconductor device equations. The new approximation of Fermi-Dirac Integrals is applied to a more generalized Einstein Relation which is an important relation in semiconductor devices.

  9. The efficiency of Flory approximation

    International Nuclear Information System (INIS)

    Obukhov, S.P.

    1984-01-01

    The Flory approximation for the self-avoiding chain problem is compared with a conventional perturbation theory expansion. While in perturbation theory each term is averaged over the unperturbed set of configurations, the Flory approximation is equivalent to the perturbation theory with the averaging over the stretched set of configurations. This imposes restrictions on the integration domain in higher order terms and they can be treated self-consistently. The accuracy δν/ν of Flory approximation for self-avoiding chain problems is estimated to be 2-5% for 1 < d < 4. (orig.)

  10. Histone deacetylase 3 represses p15INK4b and p21WAF1/cip1 transcription by interacting with Sp1

    International Nuclear Information System (INIS)

    Huang Weifeng; Tan Dapeng; Wang Xiuli; Han Songyan; Tan Jiang; Zhao Yanmei; Lu Jun; Huang Baiqu

    2006-01-01

    Histone deacetylase 3 (HDAC3) has been implicated to play roles in governing cell proliferation. Here we demonstrated that the overexpression of HDAC3 repressed transcription of p15 INK4b and p21 WAF1/cip1 genes in 293T cells, and that the recruitment of HDAC3 to the promoter regions of these genes was critical to this repression. We also showed that HDAC3 repressed GAL4-Sp1 transcriptional activity, and that Sp1 was co-immunoprecipitated with FLAG-tagged HDAC3. We conclude that HDAC3 can repress p15 INK4b and p21 WAF1/cip1 transcription by interacting with Sp1. Furthermore, knockdown of HDAC3 by RNAi up-regulated the transcriptional expression of p15 INK4b , but not that of p21 WAF1/cip1 , implicating the different roles of HDAC3 in repression of p15 INK4b and p21 WAF1/cip1 transcription. Data from this study indicate that the inhibition of p15 INK4b and p21 WAF1/cip1 may be one of the mechanisms by which HDAC3 participates in cell cycle regulation and oncogenesis

  11. Sphingosine-1-Phosphate (S1P) Signaling in Neural Progenitors.

    Science.gov (United States)

    Callihan, Phillip; Alqinyah, Mohammed; Hooks, Shelley B

    2018-01-01

    Sphingosine-1-phosphate (S1P) and its receptors are important in nervous system development. Reliable in vitro human model systems are needed to further define specific roles for S1P signaling in neural development. We have described S1P-regulated signaling, survival, and differentiation in a human embryonic stem cell-derived neuroepithelial progenitor cell line (hNP1) that expresses functional S1P receptors. These cells can be further differentiated to a neuronal cell type and therefore represent a good model system to study the role of S1P signaling in human neural development. The following sections describe in detail the culture and differentiation of hNP1 cells and two assays to measure S1P signaling in these cells.

  12. The Radial Distribution of Star Formation in Galaxies at Z approximately 1 from the 3D-HST Survey

    Science.gov (United States)

    Nelson, Erica June; vanDokkum, Pieter G.; Momcheva, Ivelina; Brammer, Gabriel; Lundgren, Britt; Skelton, Rosalind E.; Whitaker, Katherine E.; DaCunha, Elisabete; Schreiber, Natascha Foerster; Franx, Marijn; hide

    2013-01-01

    The assembly of galaxies can be described by the distribution of their star formation as a function of cosmic time. Thanks to the WFC3 grism on the Hubble Space Telescope (HST) it is now possible to measure this beyond the local Universe. Here we present the spatial distribution of H emission for a sample of 54 strongly star-forming galaxies at z 1 in the 3D-HST Treasury survey. By stacking the H emission, we find that star formation occurred in approximately exponential distributions at z approximately 1, with a median Sersic index of n = 1.0 +/- 0.2. The stacks are elongated with median axis ratios of b/a = 0.58 +/- 0.09 in H consistent with (possibly thick) disks at random orientation angles. Keck spectra obtained for a subset of eight of the galaxies show clear evidence for rotation, with inclination corrected velocities of 90.330 km s(exp 1-). The most straightforward interpretation of our results is that star formation in strongly star-forming galaxies at z approximately 1 generally occurred in disks. The disks appear to be scaled-up versions of nearby spiral galaxies: they have EW(H alpha) at approximately 100 A out to the solar orbit and they have star formation surface densities above the threshold for driving galactic scale winds.

  13. Observation of the 1P1 state of charmonium

    International Nuclear Information System (INIS)

    Armstrong, T.A.; Bettoni, D.; Bharadwaj, V.; Biino, C.; Borreani, G.; Broemmelsiek, D.; Buzzo, A.; Calabrese, R.; Ceccucci, A.; Cester, R.; Church, M.; Dalpiaz, P.; Dalpiaz, P.F.; Dibenedetto, R.; Dimitroyannis, D.; Fabbri, M.G.; Fast, J.; Gianoli, A.; Ginsburg, C.M.; Gollwitzer, K.; Hahn, A.; Hasan, M.; Hsueh, S.; Lewis, R.; Luppi, E.; Macri, M.; Majewska, A.M.; Mandelkern, M.; Marchetto, F.; Marinelli, M.; Marques, J.; Marsh, W.; Martini, M.; Masuzawa, M.; Menichetti, E.; Migliori, A.; Mussa, R.; Palestini, S.; Pallavicini, M.; Pastrone, N.; Patrignani, C.; Peoples, J. Jr.; Pesando, L.; Petrucci, F.; Pia, M.G.; Pordes, S.; Rapidis, P.; Ray, R.; Reid, J.; Rinaudo, G.; Roccuzzo, B.; Rosen, J.; Santroni, A.; Sarmiento, M.; Savrie, M.; Scalisi, A.; Schultz, J.; Seth, K.K.; Smith, A.; Smith, G.A.; Sozzi, M.; Trokenheim, S.; Weber, M.F.; Werkema, S.; Zhang, Y.; Zhao, J.; Zioulas, G.

    1992-01-01

    We have performed a search for the 1 P 1 state of charmonium resonantly formed in bar pp annihilations, close to the center of gravity of the 3 P J states. We report results from the study of the J/ψ+π 0 and J/ψ+2π final states. We have observed a statistically significant enhancement in the bar p+p→J/ψ+π 0 cross section at √s congruent 3526.2 MeV. This enhancement has the characteristics of a narrow resonance of mass, total width, and production cross section consistent with what is expected for the 1 P 1 state. In our search we have found no candidates for the reactions bar p+p→J/ψ+π 0 +π 0 and bar p+p→J/ψ+π + +π -

  14. A de-novo interstitial microduplication involving 2p16.1-p15 and mirroring 2p16.1-p15 microdeletion syndrome: Clinical and molecular analysis.

    Science.gov (United States)

    Mimouni-Bloch, Aviva; Yeshaya, Josepha; Kahana, Sarit; Maya, Idit; Basel-Vanagaite, Lina

    2015-11-01

    Microdeletions of various sizes in the 2p16.1-p15 chromosomal region have been grouped together under the 2p16.1-p15 microdeletion syndrome. Children with this syndrome generally share certain features including microcephaly, developmental delay, facial dysmorphism, urogenital and skeletal abnormalities. We present a child with a de-novo interstitial 1665 kb duplication of 2p16.1-p15. Clinical features of this child are distinct from those of children with the 2p16.1-p15 microdeletion syndrome, specifically the head circumference which is within the normal range and mild intellectual disability with absence of autistic behaviors. Microduplications many times bear milder clinical phenotypes in comparison with corresponding microdeletion syndromes. Indeed, as compared to the microdeletion syndrome patients, the 2p16.1-p15 microduplication seems to have a milder cognitive effect and no effect on other body systems. Limited information available in genetic databases about cases with overlapping duplications indicates that they all have abnormal developmental phenotypes. The involvement of genes in this location including BCL11A, USP34 and PEX13, affecting fundamental developmental processes both within and outside the nervous system may explain the clinical features of the individual described in this report. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  15. Optical transition energy of magneto-polaron in a GaAs{sub 0.9}P{sub 0.1}/GaAs{sub 0.6}P{sub 0.4} quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Vinolin, Ada [Dept. of Physics, Madurai Kamaraj University College, Alagarkoil Road, Madurai-625002. India (India); Peter, A. John, E-mail: a.john.peter@gmail.com [Dept. of Physics, Govt. Arts College, Melur-625106. Madurai. India (India)

    2015-06-24

    Magneto-LO-polaron in a cylindrical GaAs{sub 0.9} P{sub 0.1} / GaAs{sub 0.6} P{sub 0.4} quantum dot is investigated taking into consideration of geometrical confinement effect. The effects of phonon on the exciton binding energy and the interband emission energy as a function of dot radius are found. The calculations are performed within the single band effective mass approximation using the variational method based on the Lee-Low-Pine LLP transformation.

  16. Optical rectification in a strained GaAs{sub 0.9}P{sub 0.1}/GaAs{sub 0.6}P{sub 0.4} quantum dot: Simultaneous effects of electric and magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Vinolin, Ada [Dept. of Physics, Madurai Kamaraj University College, Alagarkoil Road, Madurai-625002 (India); Peter, A. John, E-mail: a.john.peter@gmail.com [Dept. of Physics, Government Arts College, Melur-625106, Tamilnadu (India)

    2014-04-24

    Simultaneous effects of electric field and magnetic field on exciton binding energy as a function of dot radius in a cylindrical GaAs{sub 0.9}P{sub 0.1}/GaAs{sub 0.6}P{sub 0.4} strained quantum dot are investigated. The strain contribution includes the strong built-in electric field induced by the spontaneous and piezoelectric polarizations. Numerical calculations are performed using variational procedure within the single band effective mass approximation. Optical rectification in the GaAs{sub 0.9}P{sub 0.1}/GaAs{sub 0.6}P{sub 0.4} quantum dot is computed in the presence of electric and magnetic fields.

  17. Novel P-TEN-induced putative kinase 1 (PINK1) variant in Indian Parkinson's disease patient.

    Science.gov (United States)

    Halder, Tamali; Raj, Janak; Sharma, Vivek; Das, Parimal

    2015-09-25

    Loss-of-function mutation in PINK1 is known for causing autosomal recessive early onset Parkinsonism accounting approximately 6.5% of PD cases. Recently, PINK1 has also been shown to cause Parkinson's disease (PD) in eastern India. Present study is aimed to see its contribution in north-Indian PD patients. A total of 106 PD patients and 60 ethnically matched healthy controls were included in the study. All the patients were screened for mutation in PINK1 by direct DNA sequence analysis of the PCR amplicons covering all exons and exon-intron boundaries. Identified novel variant was reconfirmed by DNA sequencing of 10 randomly selected TA clones containing the variant amplicon. In vitro functional assay of the mutant protein was performed by transfecting COS-7 cell line with wild type and mutant (created by site-directed-mutagenesis) cDNA construct of PINK1 fused to N' terminal GFP followed by western blot analysis. Two potentially pathogenic, one being novel (p.Q267X) and 6 other apparently non-pathogenic variants were identified. Western blot analysis reveals production of truncated PINK1 fusion protein of ∼55kDa in p.Q267X mutant instead of 82/93kDa of wild type PINK1 fusion protein (molecular weight of GFP is ∼27kDa). Our study concludes that PINK1 variants are prevalent for causing Parkinson's disease (PD) in India, as revealed by the occurrence of 1.8% (2/106) in PD patients from north Indian population. The novel homozygous variant of PINK1 (c.799C>T) reported here is the plausible cause for disease manifestation in this patient. Future study, however, would be helpful to understand the functional mechanism how this premature PINK1 protein (p.Q267X) responds to cellular stress leading to the PD pathophysiology. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. Approximation of the cross-sections for charged-particle emission reactions near the threshold

    International Nuclear Information System (INIS)

    Badikov, S.A.; Pashchenko, A.B.

    1990-01-01

    We perform an analytical approximation of the energy dependence of the cross-sections for the reactions (n,p) and (n,γ) from the BOSPOR library, correct them for the latest differential and integral experimental data using the common features, characteristic of the energy dependence of the threshold reaction cross-section and making some physical assumptions. 19 refs, 1 fig., 1 tab

  19. Does the delta quench Gamow-Teller strength in (p,n)- and (p vector,p vector')-reactions

    International Nuclear Information System (INIS)

    Osterfeld, F.; Schulte, A.; Udagawa, T.; Yabe, M.

    1986-01-01

    Microscopic analyses of complete forward angle intermediate energy (p,n)-, ( 3 He,t)- and (p vector,p vector')-spin-flip spectra are presented for the reactions 90 Zr(p,n), 90 Zr( 3 He,t) and 90 Zr(p vector,p vector'). It is shown that the whole spectra up to high excitation energies (E X ∝50 MeV) are the result of correlated one-particle-one-hole (1p1h) spin-isospin transitions only. The spectra reflect, therefore, the linear spin-isospin response of the target nucleus to the probing external hadronic fields. Our results suggest that the measured (p,n)-, ( 3 He,t)- and (p vector,p vector')-cross sections are compatible with the transition strength predictions as obtained from random phase approximation (RPA) calculations. This means that the Δ isobar quenching mechanism is likely to be rather small. (orig.)

  20. Data analysis and approximate models model choice, location-scale, analysis of variance, nonparametric regression and image analysis

    CERN Document Server

    Davies, Patrick Laurie

    2014-01-01

    Introduction IntroductionApproximate Models Notation Two Modes of Statistical AnalysisTowards One Mode of Analysis Approximation, Randomness, Chaos, Determinism ApproximationA Concept of Approximation Approximation Approximating a Data Set by a Model Approximation Regions Functionals and EquivarianceRegularization and Optimality Metrics and DiscrepanciesStrong and Weak Topologies On Being (almost) Honest Simulations and Tables Degree of Approximation and p-values ScalesStability of Analysis The Choice of En(α, P) Independence Procedures, Approximation and VaguenessDiscrete Models The Empirical Density Metrics and Discrepancies The Total Variation Metric The Kullback-Leibler and Chi-Squared Discrepancies The Po(λ) ModelThe b(k, p) and nb(k, p) Models The Flying Bomb Data The Student Study Times Data OutliersOutliers, Data Analysis and Models Breakdown Points and Equivariance Identifying Outliers and Breakdown Outliers in Multivariate Data Outliers in Linear Regression Outliers in Structured Data The Location...

  1. Prestack wavefield approximations

    KAUST Repository

    Alkhalifah, Tariq

    2013-01-01

    The double-square-root (DSR) relation offers a platform to perform prestack imaging using an extended single wavefield that honors the geometrical configuration between sources, receivers, and the image point, or in other words, prestack wavefields. Extrapolating such wavefields, nevertheless, suffers from limitations. Chief among them is the singularity associated with horizontally propagating waves. I have devised highly accurate approximations free of such singularities which are highly accurate. Specifically, I use Padé expansions with denominators given by a power series that is an order lower than that of the numerator, and thus, introduce a free variable to balance the series order and normalize the singularity. For the higher-order Padé approximation, the errors are negligible. Additional simplifications, like recasting the DSR formula as a function of scattering angle, allow for a singularity free form that is useful for constant-angle-gather imaging. A dynamic form of this DSR formula can be supported by kinematic evaluations of the scattering angle to provide efficient prestack wavefield construction. Applying a similar approximation to the dip angle yields an efficient 1D wave equation with the scattering and dip angles extracted from, for example, DSR ray tracing. Application to the complex Marmousi data set demonstrates that these approximations, although they may provide less than optimal results, allow for efficient and flexible implementations. © 2013 Society of Exploration Geophysicists.

  2. Prestack wavefield approximations

    KAUST Repository

    Alkhalifah, Tariq

    2013-09-01

    The double-square-root (DSR) relation offers a platform to perform prestack imaging using an extended single wavefield that honors the geometrical configuration between sources, receivers, and the image point, or in other words, prestack wavefields. Extrapolating such wavefields, nevertheless, suffers from limitations. Chief among them is the singularity associated with horizontally propagating waves. I have devised highly accurate approximations free of such singularities which are highly accurate. Specifically, I use Padé expansions with denominators given by a power series that is an order lower than that of the numerator, and thus, introduce a free variable to balance the series order and normalize the singularity. For the higher-order Padé approximation, the errors are negligible. Additional simplifications, like recasting the DSR formula as a function of scattering angle, allow for a singularity free form that is useful for constant-angle-gather imaging. A dynamic form of this DSR formula can be supported by kinematic evaluations of the scattering angle to provide efficient prestack wavefield construction. Applying a similar approximation to the dip angle yields an efficient 1D wave equation with the scattering and dip angles extracted from, for example, DSR ray tracing. Application to the complex Marmousi data set demonstrates that these approximations, although they may provide less than optimal results, allow for efficient and flexible implementations. © 2013 Society of Exploration Geophysicists.

  3. Smad3 deficiency leads to mandibular condyle degradation via the sphingosine 1-phosphate (S1P)/S1P3 signaling axis.

    Science.gov (United States)

    Mori, Hiroki; Izawa, Takashi; Tanaka, Eiji

    2015-10-01

    Temporomandibular joint osteoarthritis is a degenerative disease that is characterized by permanent cartilage destruction. Transforming growth factor (TGF)-β is one of the most abundant cytokines in the bone matrix and is shown to regulate the migration of osteoprogenitor cells. It is hypothesized that TGF-β/Smad3 signaling affects cartilage homeostasis by influencing sphingosine 1-phosphate (S1P)/S1P receptor signaling and chondrocyte migration. We therefore investigated the molecular mechanisms by which crosstalk may occur between TGF-β/Smad3 and S1P/S1P receptor signaling to maintain condylar cartilage and to prevent temporomandibular joint osteoarthritis. Abnormalities in the condylar subchondral bone, including dynamic changes in bone mineral density and microstructure, were observed in Smad3(-/-) mice by microcomputed tomography. Cell-free regions and proteoglycan loss characterized the cartilage degradation present, and increased numbers of apoptotic chondrocytes and matrix metalloproteinase 13(+) chondrocytes were also detected. Furthermore, expression of S1P receptor 3 (S1P3), but not S1P1 or S1P2, was significantly down-regulated in the condylar cartilage of Smad3(-/-) mice. By using RNA interference technology and pharmacologic tools, S1P was found to transactivate Smad3 in an S1P3/TGF-β type II receptor-dependent manner, and S1P3 was found to be required for TGF-β-induced migration of chondrocyte cells and downstream signal transduction via Rac1, RhoA, and Cdc42. Taken together, these results indicate that the Smad3/S1P3 signaling pathway plays an important role in the pathogenesis of temporomandibular joint osteoarthritis. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  4. On the Two-Moment Approximation of the Discrete-Time GI/G/1 Queue with a Single Vacation

    Directory of Open Access Journals (Sweden)

    Doo Ho Lee

    2016-01-01

    Full Text Available We consider a discrete-time GI/G/1 queue in which the server takes exactly one vacation each time the system becomes empty. The interarrival times of arriving customers, the service times, and the vacation times are all generic discrete random variables. Under our study, we derive an exact transform-free expression for the stationary system size distribution through the modified supplementary variable technique. Utilizing obtained results, we introduce a simple two-moment approximation for the system size distribution. From this, approximations for the mean system size along with the system size distribution could be obtained. Finally, some numerical examples are given to validate the proposed approximation method.

  5. PPARγ agonists upregulate sphingosine 1-phosphate (S1P) receptor 1 expression, which in turn reduces S1P-induced [Ca(2+)]i increases in renal mesangial cells.

    Science.gov (United States)

    Koch, Alexander; Völzke, Anja; Puff, Bianca; Blankenbach, Kira; Meyer Zu Heringdorf, Dagmar; Huwiler, Andrea; Pfeilschifter, Josef

    2013-11-01

    We previously identified peroxisome proliferator-activated receptor gamma (PPARγ) agonists (thiazolidinediones, TZDs) as modulators of the sphingolipid metabolism in renal mesangial cells. TZDs upregulated sphingosine kinase 1 (SK-1) and increased the formation of intracellular sphingosine 1-phosphate (S1P), which in turn reduced the expression of pro-fibrotic connective tissue growth factor. Since S1P also acts as extracellular ligand at specific S1P receptors (S1PR, S1P1-5), we investigated here the effect of TZDs on S1PR expression in mesangial cells and evaluated the functional consequences by measuring S1P-induced increases in intracellular free Ca(2+) concentration ([Ca(2+)]i). Treatment with two different TZDs, troglitazone and rosiglitazone, enhanced S1P1 mRNA and protein expression in rat mesangial cells, whereas S1P2-5 expression levels were not altered. Upregulation of S1P1 mRNA upon TZD treatment was also detected in human mesangial cells and mouse glomeruli. PPARγ antagonism and promoter studies revealed that the TZD-dependent S1P1 mRNA induction involved a functional PPAR response element in the S1P1 promoter. Pharmacological approaches disclosed that S1P-induced [Ca(2+)]i increases in rat mesangial cells were predominantly mediated by S1P2 and S1P3. Interestingly, the transcriptional upregulation of S1P1 by TZDs resulted in a reduction of S1P-induced [Ca(2+)]i increases, which was reversed by the S1P1/3 antagonist VPC-23019, the protein kinase C (PKC) inhibitor PKC-412, and by S1P1 siRNA. These data suggest that PPARγ-dependent upregulation of S1P1 leads to an inhibition of S1P-induced Ca(2+) signaling in a PKC-dependent manner. Overall, these results reveal that TZDs not only modulate intracellular S1P levels but also regulate S1PR signaling by increasing S1P1 expression in mesangial cells. © 2013.

  6. APPROXIMATIONS TO PERFORMANCE MEASURES IN QUEUING SYSTEMS

    Directory of Open Access Journals (Sweden)

    Kambo, N. S.

    2012-11-01

    Full Text Available Approximations to various performance measures in queuing systems have received considerable attention because these measures have wide applicability. In this paper we propose two methods to approximate the queuing characteristics of a GI/M/1 system. The first method is non-parametric in nature, using only the first three moments of the arrival distribution. The second method treads the known path of approximating the arrival distribution by a mixture of two exponential distributions by matching the first three moments. Numerical examples and optimal analysis of performance measures of GI/M/1 queues are provided to illustrate the efficacy of the methods, and are compared with benchmark approximations.

  7. Uniform analytic approximation of Wigner rotation matrices

    Science.gov (United States)

    Hoffmann, Scott E.

    2018-02-01

    We derive the leading asymptotic approximation, for low angle θ, of the Wigner rotation matrix elements, dm1m2 j(θ ) , uniform in j, m1, and m2. The result is in terms of a Bessel function of integer order. We numerically investigate the error for a variety of cases and find that the approximation can be useful over a significant range of angles. This approximation has application in the partial wave analysis of wavepacket scattering.

  8. Structure of Sn1−xGex random alloys as obtained from the coherent potential approximation

    KAUST Repository

    Pulikkotil, J. J.; Chroneos, A.; Schwingenschlö gl, Udo

    2011-01-01

    The structure of the Sn1−xGex random alloys is studied using density functional theory and the coherent potential approximation. We report on the deviation of the Sn1−xGex alloys from Vegard’s law, addressing their full compositional range

  9. Electrical dipole polarizability and spin M1 strength from {sup 48}Ca(p,p') data under 0; Elektrische Dipol-Polarisierbarkeit und Spin-M1-Staerke aus {sup 48}Ca(p,p')-Daten unter 0

    Energy Technology Data Exchange (ETDEWEB)

    Birkhan, Jonny Hubertus

    2016-07-01

    In this thesis, proton scattering data on the nucleus {sup 48}Ca at very forward angles had been analysed. The data stem from a measurement campaign which was launched at the Research Centre of Nuclear Physics at Osaka, Japan, in the past. One of the two objectives of this analysis was to extract a value for the static electric dipole polarisability from the isovector giant dipole resonance (IVGDR). The second objective was to extract the total electromagnetic M1 strength B(M1) of the spin-flip transition which excites the prominent 1{sup +} state at an excitation energy of E{sub x}=10.22 MeV. The polarisability was calculated from the distribution of photo-absorption cross sections within an energy range from E{sub x}=11 MeV to E{sub x}=26 MeV. The photo-absorption cross sections had been deduced from the distribution of E1 cross sections by the method of virtual photons. For this purpose the experimental cross sections had been deconvoluted by a multipole deconvolution into an E1 part and a background part. Then, the best estimate of the polarisability is given by α{sub D}=(1.36±0.14) fm{sup 3}. If a E3 model was included into the multipole decomposition of the (p,p') data the result increased up to α{sub D}=(1.50±0.09) fm{sup 3}. The deviation between these two results is mainly due to the fact that the multipole decomposition is very sensitive on the background function. Assuming that the the IVGDR of the nuclei {sup 48}Ca and {sup 40}Ca have approximately the same structure, estimates for the polarisability of the nucleus {sup 48}Ca could be drawn from {sup 40}Ca(γ,abs) data. Additionally, data from a {sup 48}Ca(e,e'n) measurement were used to estimate the polarisability of the nucleus {sup 48}Ca. Its polarisability seems to fall within the range of α{sub D}=(1.50±0.09) fm{sup 3} and α{sub D}=(1.69±0.03) fm{sup 3}. Beside this, it could be shown by the {sup 40}Ca data that a significant contribution to the polarisability has to be expected

  10. Sphingosine 1-phosphate (S1P) induces COX-2 expression and PGE2 formation via S1P receptor 2 in renal mesangial cells.

    Science.gov (United States)

    Völzke, Anja; Koch, Alexander; Meyer Zu Heringdorf, Dagmar; Huwiler, Andrea; Pfeilschifter, Josef

    2014-01-01

    Understanding the mechanisms of sphingosine 1-phosphate (S1P)-induced cyclooxygenase (COX)-2 expression and prostaglandin E2 (PGE2) formation in renal mesangial cells may provide potential therapeutic targets to treat inflammatory glomerular diseases. Thus, we evaluated the S1P-dependent signaling mechanisms which are responsible for enhanced COX-2 expression and PGE2 formation in rat mesangial cells under basal conditions. Furthermore, we investigated whether these mechanisms are operative in the presence of angiotensin II (Ang II) and of the pro-inflammatory cytokine interleukin-1β (IL-1β). Treatment of rat and human mesangial cells with S1P led to concentration-dependent enhanced expression of COX-2. Pharmacological and molecular biology approaches revealed that the S1P-dependent increase of COX-2 mRNA and protein expression was mediated via activation of S1P receptor 2 (S1P2). Further, inhibition of Gi and p42/p44 MAPK signaling, both downstream of S1P2, abolished the S1P-induced COX-2 expression. In addition, S1P/S1P2-dependent upregulation of COX-2 led to significantly elevated PGE2 levels, which were further potentiated in the presence of Ang II and IL-1β. A functional consequence downstream of S1P/S1P2 signaling is mesangial cell migration that is stimulated by S1P. Interestingly, inhibition of COX-2 by celecoxib and SC-236 completely abolished the migratory response. Overall, our results demonstrate that extracellular S1P induces COX-2 expression via activation of S1P2 and subsequent Gi and p42/p44 MAPK-dependent signaling in renal mesangial cells leading to enhanced PGE2 formation and cell migration that essentially requires COX-2. Thus, targeting S1P/S1P2 signaling pathways might be a novel strategy to treat renal inflammatory diseases. © 2013.

  11. SUN family proteins Sun4p, Uth1p and Sim1p are secreted from Saccharomyces cerevisiae and produced dependently on oxygen level.

    Directory of Open Access Journals (Sweden)

    Evgeny Kuznetsov

    Full Text Available The SUN family is comprised of proteins that are conserved among various yeasts and fungi, but that are absent in mammals and plants. Although the function(s of these proteins are mostly unknown, they have been linked to various, often unrelated cellular processes such as those connected to mitochondrial and cell wall functions. Here we show that three of the four Saccharomyces cerevisiae SUN family proteins, Uth1p, Sim1p and Sun4p, are efficiently secreted out of the cells in different growth phases and their production is affected by the level of oxygen. The Uth1p, Sim1p, Sun4p and Nca3p are mostly synthesized during the growth phase of both yeast liquid cultures and colonies. Culture transition to slow-growing or stationary phases is linked with a decreased cellular concentration of Sim1p and Sun4p and with their efficient release from the cells. In contrast, Uth1p is released mainly from growing cells. The synthesis of Uth1p and Sim1p, but not of Sun4p, is repressed by anoxia. All four proteins confer cell sensitivity to zymolyase. In addition, Uth1p affects cell sensitivity to compounds influencing cell wall composition and integrity (such as Calcofluor white and Congo red differently when growing on fermentative versus respiratory carbon sources. In contrast, Uth1p is essential for cell resistance to boric acids irrespective of carbon source. In summary, our novel findings support the hypothesis that SUN family proteins are involved in the remodeling of the yeast cell wall during the various phases of yeast culture development and under various environmental conditions. The finding that Uth1p is involved in cell sensitivity to boric acid, i.e. to a compound that is commonly used as an important antifungal in mycoses, opens up new possibilities of investigating the mechanisms of boric acid's action.

  12. Deficiency of G1 regulators P53, P21Cip1 and/or pRb decreases hepatocyte sensitivity to TGFβ cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Harrison David J

    2007-11-01

    Full Text Available Abstract Background TGFβ is critical to control hepatocyte proliferation by inducing G1-growth arrest through multiple pathways leading to inhibition of E2F transcription activity. The retinoblastoma protein pRb is a key controller of E2F activity and G1/S transition which can be inhibited in viral hepatitis. It is not known whether the impairment of pRb would alter the growth inhibitory potential of TGFβ in disease. We asked how Rb-deficiency would affect responses to TGFβ-induced cell cycle arrest. Results Primary hepatocytes isolated from Rb-floxed mice were infected with an adenovirus expressing CRE-recombinase to delete the Rb gene. In control cells treatment with TGFβ prevented cells to enter S phase via decreased cMYC activity, activation of P16INK4A and P21Cip and reduction of E2F activity. In Rb-null hepatocytes, cMYC activity decreased slightly but P16INK4A was not activated and the great majority of cells continued cycling. Rb is therefore central to TGFβ-induced cell cycle arrest in hepatocytes. However some Rb-null hepatocytes remained sensitive to TGFβ-induced cell cycle arrest. As these hepatocytes expressed very high levels of P21Cip1 and P53 we investigated whether these proteins regulate pRb-independent signaling to cell cycle arrest by evaluating the consequences of disruption of p53 and p21Cip1. Hepatocytes deficient in p53 or p21Cip1 showed diminished growth inhibition by TGFβ. Double deficiency had a similar impact showing that in cells containing functional pRb; P21Cip and P53 work through the same pathway to regulate G1/S in response to TGFβ. In Rb-deficient cells however, p53 but not p21Cip deficiency had an additive effect highlighting a pRb-independent-P53-dependent effector pathway of inhibition of E2F activity. Conclusion The present results show that otherwise genetically normal hepatocytes with disabled p53, p21Cip1 or Rb genes respond less well to the antiproliferative effects of TGFβ. As the function of

  13. Sphingosine 1-Phosphate (S1P) Carrier-dependent Regulation of Endothelial Barrier

    Science.gov (United States)

    Wilkerson, Brent A.; Grass, G. Daniel; Wing, Shane B.; Argraves, W. Scott; Argraves, Kelley M.

    2012-01-01

    Sphingosine 1-phosphate (S1P) is a blood-borne lysosphingolipid that acts to promote endothelial cell (EC) barrier function. In plasma, S1P is associated with both high density lipoproteins (HDL) and albumin, but it is not known whether the carriers impart different effects on S1P signaling. Here we establish that HDL-S1P sustains EC barrier longer than albumin-S1P. We showed that the sustained barrier effects of HDL-S1P are dependent on signaling by the S1P receptor, S1P1, and involve persistent activation of Akt and endothelial NOS (eNOS), as well as activity of the downstream NO target, soluble guanylate cyclase (sGC). Total S1P1 protein levels were found to be higher in response to HDL-S1P treatment as compared with albumin-S1P, and this effect was not associated with increased S1P1 mRNA or dependent on de novo protein synthesis. Several pieces of evidence indicate that long term EC barrier enhancement activity of HDL-S1P is due to specific effects on S1P1 trafficking. First, the rate of S1P1 degradation, which is proteasome-mediated, was slower in HDL-S1P-treated cells as compared with cells treated with albumin-S1P. Second, the long term barrier-promoting effects of HDL-S1P were abrogated by treatment with the recycling blocker, monensin. Finally, cell surface levels of S1P1 and levels of S1P1 in caveolin-enriched microdomains were higher after treatment with HDL-S1P as compared with albumin-S1P. Together, the findings reveal S1P carrier-specific effects on S1P1 and point to HDL as the physiological mediator of sustained S1P1-PI3K-Akt-eNOS-sGC-dependent EC barrier function. PMID:23135269

  14. Sphingosine 1-Phosphate (S1P) Receptors 1 and 2 Coordinately Induce Mesenchymal Cell Migration through S1P Activation of Complementary Kinase Pathways*

    Science.gov (United States)

    Quint, Patrick; Ruan, Ming; Pederson, Larry; Kassem, Moustapha; Westendorf, Jennifer J.; Khosla, Sundeep; Oursler, Merry Jo

    2013-01-01

    Normal bone turnover requires tight coupling of bone resorption and bone formation to preserve bone quantity and structure. With aging and during several pathological conditions, this coupling breaks down, leading to either net bone loss or excess bone formation. To preserve or restore normal bone metabolism, it is crucial to determine the mechanisms by which osteoclasts and osteoblast precursors interact and contribute to coupling. We showed that osteoclasts produce the chemokine sphingosine 1-phosphate (S1P), which stimulates osteoblast migration. Thus, osteoclast-derived S1P may recruit osteoblasts to sites of bone resorption as an initial step in replacing lost bone. In this study we investigated the mechanisms by which S1P stimulates mesenchymal (skeletal) cell chemotaxis. S1P treatment of mesenchymal (skeletal) cells activated RhoA GTPase, but this small G protein did not contribute to migration. Rather, two S1P receptors, S1PR1 and S1PR2, coordinately promoted migration through activation of the JAK/STAT3 and FAK/PI3K/AKT signaling pathways, respectively. These data demonstrate that the chemokine S1P couples bone formation to bone resorption through activation of kinase signaling pathways. PMID:23300082

  15. pOsNAR2.1:OsNAR2.1 expression enhances nitrogen uptake efficiency and grain yield in transgenic rice plants.

    Science.gov (United States)

    Chen, Jingguang; Fan, Xiaoru; Qian, Kaiyun; Zhang, Yong; Song, Miaoquan; Liu, Yu; Xu, Guohua; Fan, Xiaorong

    2017-10-01

    The nitrate (NO3-) transporter has been selected as an important gene maker in the process of environmental adoption in rice cultivars. In this work, we transferred another native OsNAR2.1 promoter with driving OsNAR2.1 gene into rice plants. The transgenic lines with exogenous pOsNAR2.1:OsNAR2.1 constructs showed enhanced OsNAR2.1 expression level, compared with wild type (WT), and 15 N influx in roots increased 21%-32% in response to 0.2 mm and 2.5 mm 15NO3- and 1.25 mm 15 NH 4 15 NO 3 . Under these three N conditions, the biomass of the pOsNAR2.1:OsNAR2.1 transgenic lines increased 143%, 129% and 51%, and total N content increased 161%, 242% and 69%, respectively, compared to WT. Furthermore in field experiments we found the grain yield, agricultural nitrogen use efficiency (ANUE), and dry matter transfer of pOsNAR2.1:OsNAR2.1 plants increased by about 21%, 22% and 21%, compared to WT. We also compared the phenotypes of pOsNAR2.1:OsNAR2.1 and pOsNAR2.1:OsNRT2.1 transgenic lines in the field, found that postanthesis N uptake differed significantly between them, and in comparison with the WT. Postanthesis N uptake (PANU) increased approximately 39% and 85%, in the pOsNAR2.1:OsNAR2.1 and pOsNAR2.1:OsNRT2.1 transgenic lines, respectively, possibly because OsNRT2.1 expression was less in the pOsNAR2.1:OsNAR2.1 lines than in the pOsNAR2.1:OsNRT2.1 lines during the late growth stage. These results show that rice NO 3 - uptake, yield and NUE were improved by increased OsNAR2.1 expression via its native promoter. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  16. Analyzing powers for the three-nucleon breakup reaction 1H(d vector,p)pn at 16 MeV

    International Nuclear Information System (INIS)

    Brown, R.E.; Ohlsen, G.G.; Correll, F.D.; Hardekopf, R.A.; Jarmie, N.

    1980-01-01

    Analyzing powers for the 1 H(d,p)pn reaction were measured at 16.0 MeV and beam polarization of approximately 0.82. Similar data for the elastic scattering 1 H(d,p) 2 H were also taken. The breakup analyzing power A/sub xz/, which attains the largest magnitude, is shown as a function of excitation energy. Angular distributions of elastic and breakup analyzing powers are compared; large differences are noted for A/sub xx/ and A/sub xz/. It is found that 1-MeV energy bins are too large to use in the study of singlet-state effects. 2 figures

  17. Hardness and Approximation for Network Flow Interdiction

    OpenAIRE

    Chestnut, Stephen R.; Zenklusen, Rico

    2015-01-01

    In the Network Flow Interdiction problem an adversary attacks a network in order to minimize the maximum s-t-flow. Very little is known about the approximatibility of this problem despite decades of interest in it. We present the first approximation hardness, showing that Network Flow Interdiction and several of its variants cannot be much easier to approximate than Densest k-Subgraph. In particular, any $n^{o(1)}$-approximation algorithm for Network Flow Interdiction would imply an $n^{o(1)}...

  18. p21(Waf1/Cip1) expression and the p53/MDM2 feedback loop in gastric carcinogenesis

    NARCIS (Netherlands)

    Craanen, M. E.; Blok, P.; Offerhaus, G. J.; Meijer, G. A.; Dekker, W.; Kuipers, E. J.; Meuwissen, S. G.

    1999-01-01

    Data are non-existent regarding coincidental alterations in the expression of p53 and its downstream target genes MDM2 and p21(Waf1/Cip1) in gastric carcinogenesis. An immunohistochemical study was therefore performed to examine the interrelationships of p53, MDM2, and p21(Waf1/Cip1) expression in a

  19. Computer program /P1-GAS/ calculates the P-0 and P-1 transfer matrices for neutron moderation in a monatomic gas

    Science.gov (United States)

    Collier, G.; Gibson, G.

    1968-01-01

    FORTRAN 4 program /P1-GAS/ calculates the P-O and P-1 transfer matrices for neutron moderation in a monatomic gas. The equations used are based on the conditions that there is isotropic scattering in the center-of-mass coordinate system, the scattering cross section is constant, and the target nuclear velocities satisfy a Maxwellian distribution.

  20. On the functional integral approach in quantum statistics. 1. Some approximations

    International Nuclear Information System (INIS)

    Dai Xianxi.

    1990-08-01

    In this paper the susceptibility of a Kondo system in a fairly wide temperature region is calculated in the first harmonic approximation in a functional integral approach. The comparison with that of the renormalization group theory shows that in this region the two results agree quite well. The expansion of the partition function with infinite independent harmonics for the Anderson model is studied. Some symmetry relations are generalized. It is a challenging problem to develop a functional integral approach including diagram analysis, mixed mode effects and some exact relations in the Anderson system proved in the functional integral approach. These topics will be discussed in the next paper. (author). 22 refs, 1 fig

  1. Approximate tensor-product preconditioners for very high order discontinuous Galerkin methods

    Science.gov (United States)

    Pazner, Will; Persson, Per-Olof

    2018-02-01

    In this paper, we develop a new tensor-product based preconditioner for discontinuous Galerkin methods with polynomial degrees higher than those typically employed. This preconditioner uses an automatic, purely algebraic method to approximate the exact block Jacobi preconditioner by Kronecker products of several small, one-dimensional matrices. Traditional matrix-based preconditioners require O (p2d) storage and O (p3d) computational work, where p is the degree of basis polynomials used, and d is the spatial dimension. Our SVD-based tensor-product preconditioner requires O (p d + 1) storage, O (p d + 1) work in two spatial dimensions, and O (p d + 2) work in three spatial dimensions. Combined with a matrix-free Newton-Krylov solver, these preconditioners allow for the solution of DG systems in linear time in p per degree of freedom in 2D, and reduce the computational complexity from O (p9) to O (p5) in 3D. Numerical results are shown in 2D and 3D for the advection, Euler, and Navier-Stokes equations, using polynomials of degree up to p = 30. For many test cases, the preconditioner results in similar iteration counts when compared with the exact block Jacobi preconditioner, and performance is significantly improved for high polynomial degrees p.

  2. The use of approximation formulae in calculations of acid-base equilibria-II: salts of mono- and diprotic acids.

    Science.gov (United States)

    Narasaki, H

    1980-02-01

    The pH of solutions of salts of mono- and diprotic acids is calculated by use of approximation formulae and the theoretically exact equations. The regions for useful application of the approximation formulae (error monoprotic acids, areas are symmetrically equal to those of the acids. For salts of diprotic acids the ranges generally depend on K(2)/K(1).

  3. 26Al(n,p)26Mg and 26Al(n,α)23Na cross sections from thermal energy to approximately 50 keV

    International Nuclear Information System (INIS)

    Koehler, P.E.; Gledenov, Yu.M.; Popov, Yu.P.

    1993-01-01

    Understanding the origin of 26 Al is important because it is one of the very few radioactive products of stellar nucleosynthesis to be observed directly by γ-ray telescopes. 26 Al has also been observed indirectly as a 26 Mg anomaly in some meterorites. The 26 Al(n,p) 26 Mg and 26 Al(n,α) 23 Na reactions are thought to be the major means for the destruction of 26 Al in some astrophysical environments, so a knowledge of the cross sections for these reactions is important for a better understanding of the origin of 26 Al. The authors have measured the 26 Al(n,p 1 ) 26 Mg and 26 Al(n,α 0 ) 23 Na cross sections from thermal energy to approximately 50 keV. Most of this energy range has not been explored by previous measurements. The measurements were made at the white neutron source of the Manuel Lujan, Jr. Neutron Scattering Center (LANSCE) using a ΔE-E solid-state detector telescope. Several resonances were observed. This data will be compared to previous measurements and the effect of the new data on the calculated nucleosynthesis of 26 Al will be discussed

  4. Discrete maximum principle for the P1 - P0 weak Galerkin finite element approximations

    Science.gov (United States)

    Wang, Junping; Ye, Xiu; Zhai, Qilong; Zhang, Ran

    2018-06-01

    This paper presents two discrete maximum principles (DMP) for the numerical solution of second order elliptic equations arising from the weak Galerkin finite element method. The results are established by assuming an h-acute angle condition for the underlying finite element triangulations. The mathematical theory is based on the well-known De Giorgi technique adapted in the finite element context. Some numerical results are reported to validate the theory of DMP.

  5. Group theoretical treatment of the low-temperature phase transition of the Cd6Ca 1/1-cubic approximant

    International Nuclear Information System (INIS)

    Tamura, R.; Shibata, K.; Nishimoto, K.; Takeuchi, S.; Edagawa, K.; Saitoh, K.; Isobe, M.; Ueda, Y.

    2005-01-01

    An antiparallel orientational transition is reported for an intermetallic compound, i.e., Cd 6 Ca crystal, which is a 1/1-1/1-1/1 crystalline approximant to the icosahedral quasicrystal Cd 5.7 Ca. A group theoretical analysis based on the Landau theory predicts that the space group of the low-temperature phase is either C2/c or C2/m, in good agreement with the observations. Accordingly, two types of orientational orderings of Cd 4 tetrahedra, which are located in the center of icosahedral clusters, may occur below 100 K: In both cases, the Cd 4 tetrahedra are orientationally ordered in an antiparallel fashion along the [110] direction of the high temperature body-centered-cubic phase. Such a transition in a metal is reminiscent of orientational transitions in molecular solids

  6. Geology of drill hole UE25p No. 1: A test hole into pre-Tertiary rocks near Yucca Mountain, southern Nevada

    International Nuclear Information System (INIS)

    Carr, M.D.; Waddell, S.J.; Vick, G.S.; Stock, J.M.; Monsen, S.A.; Harris, A.G.; Cork, B.W.; Byers, F.M. Jr.

    1986-01-01

    Yucca Mountain in southern Nye County, Nevada, has been proposed as a potential site for the underground disposal of high-level nuclear waste. An exploratory drill hole designated UE25p No. 1 was drilled 3 km east of the proposed repository site to investigate the geology and hydrology of the rocks that underlie the Tertiary volcanic and sedimentary rock sequence forming Yucca Mountain. Silurian dolomite assigned to the Roberts Mountain and Lone Mountain Formations was intersected below the Tertiary section between a depth of approximately 1244 m (4080 ft) and the bottom of the drill hole at 1807 m (5923 ft). These formations are part of an important regional carbonate aquifer in the deep ground-water system. Tertiary units deeper than 1139 m (3733 ft) in drill hole UE25p No. 1 are stratigraphically older than any units previously penetrated by drill holes at Yucca Mountain. These units are, in ascending order, the tuff of Yucca Flat, an unnamed calcified ash-flow tuff, and a sequence of clastic deposits. The upper part of the Tertiary sequence in drill hole UE25p No. 1 is similar to that found in other drill holes at Yucca Mountain. The Tertiary sequence is in fault contact with the Silurian rocks. This fault between Tertiary and Paleozoic rocks may correlate with the Fran Ridge fault, a steeply westward-dipping fault exposed approximately 0.5 km east of the drill hole. Another fault intersects UE25p No. 1 at 873 m (2863 ft), but its surface trace is concealed beneath the valley west of the Fran Ridge fault. The Paintbrush Canyon fault, the trace of which passes less than 100 m (330 ft) east of the drilling site, intersects drill hole UE25p No. 1 at a depth of approximately 78 m (255 ft). The drill hole apparently intersected the west flank of a structural high of pre-Tertiary rocks, near the eastern edge of the Crater Flat structural depression

  7. Evaluation of structural vacancies for 1/1-Al-Re-Si approximant crystals by positron annihilation spectroscopy

    Science.gov (United States)

    Yamada, K.; Suzuki, H.; Kitahata, H.; Matsushita, Y.; Nozawa, K.; Komori, F.; Yu, R. S.; Kobayashi, Y.; Ohdaira, T.; Oshima, N.; Suzuki, R.; Takagiwa, Y.; Kimura, K.; Kanazawa, I.

    2018-01-01

    The size of structural vacancies and structural vacancy density of 1/1-Al-Re-Si approximant crystals with different Re compositions were evaluated by positron annihilation lifetime and Doppler broadening measurements. Incident positrons were found to be trapped at the monovacancy-size open space surrounded by Al atoms. From a previous analysis using the maximum entropy method and Rietveld method, such an open space is shown to correspond to the centre of Al icosahedral clusters, which locates at the vertex and body centre. The structural vacancy density of non-metallic Al73Re17Si10 was larger than that of metallic Al73Re15Si12. The observed difference in the structural vacancy density reflects that in bonding nature and may explain that in the physical properties of the two samples.

  8. Contribution of Arginine 13 to the Catalytic Activity of Human Class Pi Glutathione Transferase P1-1

    International Nuclear Information System (INIS)

    Kong, Ji Na; Jo, Dong Hyeon; Do, Hyun Dong; Lee, Jin Ju; Kong, Kwang Hoon

    2010-01-01

    Arg13 is a conserved active-site residue in all known Pi class glutathione S-transferases (GSTs) and in most Alpha class GSTs. To evaluate its contribution to substrate binding and catalysis of this residue, three mutants (R13A, R13K, and R13L) were expressed in Escherichia coli and purified by GSH affinity chromatography. The substitutions of Arg13 significantly affected GSH-conjugation activity, while scarcely affecting glutathione peroxidase or steroid isomerase activities. Mutation of Arg13 into Ala largely reduced the GSH-conjugation activity by approximately 85 - 95%, whereas substitutions by Lys and Leu barely affected activity. These results suggest that, in the GSH-conjugation activity of hGST P1-1, the contribution of Arg13 toward catalytic activity is highly dependent on substrate specificities and the size of the side chain at position 13. From the kinetic parameters, introduction of larger side chains at position 13 results in stronger affinity (Leu > Lys, Arg > Ala) towards GSH. The substitutions of Arg13 with alanine and leucine significantly affected k cat , whereas substitution with Lys was similar to that of the wild type, indicating the significance of a positively charged residue at position 13. From the plots of log (k cat /K m CDNB ) against pH, the pK a values of the thiol group of GSH bound in R13A, R13K, and R13L were estimated to be 1.8, 1.4, and 1.8 pK units higher than the pK a value of the wildtype enzyme, demonstrating the contribution of the Arg13 guanidinium group to the electrostatic field in the active site. From these results, we suggest that contribution of Arg13 in substrate binding is highly dependent on the nature of the electrophilic substrates, while in the catalytic mechanism, it stabilizes the GSH thiolate through hydrogen bonding

  9. Selective coupling of the S1P3 receptor subtype to S1P-mediated RhoA activation and cardioprotection.

    Science.gov (United States)

    Yung, Bryan S; Brand, Cameron S; Xiang, Sunny Y; Gray, Charles B B; Means, Christopher K; Rosen, Hugh; Chun, Jerold; Purcell, Nicole H; Brown, Joan Heller; Miyamoto, Shigeki

    2017-02-01

    Sphingosine-1-phosphate (S1P), a bioactive lysophospholipid, is generated and released at sites of tissue injury in the heart and can act on S1P 1 , S1P 2 , and S1P 3 receptor subtypes to affect cardiovascular responses. We established that S1P causes little phosphoinositide hydrolysis and does not induce hypertrophy indicating that it does not cause receptor coupling to G q . We previously demonstrated that S1P confers cardioprotection against ischemia/reperfusion by activating RhoA and its downstream effector PKD. The S1P receptor subtypes and G proteins that regulate RhoA activation and downstream responses in the heart have not been determined. Using siRNA or pertussis toxin to inhibit different G proteins in NRVMs we established that S1P regulates RhoA activation through Gα 13 but not Gα 12 , Gα q , or Gα i . Knockdown of the three major S1P receptors using siRNA demonstrated a requirement for S1P 3 in RhoA activation and subsequent phosphorylation of PKD, and this was confirmed in studies using isolated hearts from S1P 3 knockout (KO) mice. S1P treatment reduced infarct size induced by ischemia/reperfusion in Langendorff perfused wild-type (WT) hearts and this protection was abolished in the S1P 3 KO mouse heart. CYM-51736, an S1P 3 -specific agonist, also decreased infarct size after ischemia/reperfusion to a degree similar to that achieved by S1P. The finding that S1P 3 receptor- and Gα 13 -mediated RhoA activation is responsible for protection against ischemia/reperfusion suggests that selective targeting of S1P 3 receptors could provide therapeutic benefits in ischemic heart disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Epigenetic regulation of pro-inflammatory cytokine secretion by sphingosine 1-phosphate (S1P) in acute lung injury: Role of S1P lyase.

    Science.gov (United States)

    Ebenezer, David L; Fu, Panfeng; Suryadevara, Vidyani; Zhao, Yutong; Natarajan, Viswanathan

    2017-01-01

    Cellular level of sphingosine-1-phosphate (S1P), the simplest bioactive sphingolipid, is tightly regulated by its synthesis catalyzed by sphingosine kinases (SphKs) 1 & 2 and degradation mediated by S1P phosphatases, lipid phosphate phosphatases, and S1P lyase. The pleotropic actions of S1P are attributed to its unique inside-out (extracellular) signaling via G-protein-coupled S1P1-5 receptors, and intracellular receptor independent signaling. Additionally, S1P generated in the nucleus by nuclear SphK2 modulates HDAC1/2 activity, regulates histone acetylation, and transcription of pro-inflammatory genes. Here, we present data on the role of S1P lyase mediated S1P signaling in regulating LPS-induced inflammation in lung endothelium. Blocking S1P lyase expression or activity attenuated LPS-induced histone acetylation and secretion of pro-inflammatory cytokines. Degradation of S1P by S1P lyase generates Δ2-hexadecenal and ethanolamine phosphate and the long-chain fatty aldehyde produced in the cytoplasmic compartment of the endothelial cell seems to modulate histone acetylation pattern, which is different from the nuclear SphK2/S1P signaling and inhibition of HDAC1/2. These in vitro studies suggest that S1P derived long-chain fatty aldehyde may be an epigenetic regulator of pro-inflammatory genes in sepsis-induced lung inflammation. Trapping fatty aldehydes and other short chain aldehydes such as 4-hydroxynonenal derived from S1P degradation and lipid peroxidation, respectively by cell permeable agents such as phloretin or other aldehyde trapping agents may be useful in treating sepsis-induced lung inflammation via modulation of histone acetylation. . Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. P2X1 receptors localized in lipid rafts mediate ATP motor responses in the human vas deferens longitudinal muscles.

    Science.gov (United States)

    Donoso, María Verónica; Norambuena, Andrés; Navarrete, Camilo; Poblete, Inés; Velasco, Alfredo; Huidobro-Toro, Juan Pablo

    2014-02-01

    To assess the role of the P2X1 receptors (P2X1R) in the longitudinal and circular layers of the human vas deferens, ex vivo-isolated strips or rings were prepared from tissue biopsies to record isometric contractions. To ascertain its membrane distribution, tissue extracts were analyzed by immunoblotting following sucrose gradient ultracentrifugation. ATP, alpha,beta-methylene ATP, or electrical field stimulation elicited robust contractions of the longitudinal layer but not of the circular layer which demonstrated inconsistent responses. Alpha,beta-methylene ATP generated stronger and more robust contractions than ATP. In parallel, prostatic segments of the rat vas deferens were examined. The motor responses in both species were not sustained but decayed within the first minute, showing desensitization to additional applications. Cross-desensitization was established between alpha,beta-methylene ATP or ATP-evoked contractions and electrical field stimulation-induced contractions. Full recovery of the desensitized motor responses required more than 30 min and showed a similar pattern in human and rat tissues. Immunoblot analysis of the human vas deferens extracts revealed a P2X1R oligomer of approximately 200 kDa under nonreducing conditions, whereas dithiothreitol-treated extracts showed a single band of approximately 70 kDa. The P2X1R was identified in ultracentrifugation fractions containing 15%-29% sucrose; the receptor localized in the same fractions as flotillin-1, indicating that it regionalized into smooth muscle lipid rafts. In conclusion, ATP plays a key role in human vas deferens contractile responses of the longitudinal smooth muscle layer, an effect mediated through P2X1Rs.

  12. A study of the consistent and the lumped source approximations in finite element neutron diffusion calculations

    International Nuclear Information System (INIS)

    Ozgener, B.; Azgener, H.A.

    1991-01-01

    In finite element formulations for the solution of the within-group neutron diffusion equation, two different treatments are possible for the group source term: the consistent source approximation (CSA) and the lumped source approximation (LSA). CSA results in intra-group scattering and fission matrices which have the same nondiagonal structure as the global coefficient matrix. This situation might be regarded as a disadvantage, compared to the conventional (i.e. finite difference) methods where the intra-group scattering and fission matrices are diagonal. To overcome this disadvantage, LSA could be used to diagonalize these matrices. LSA is akin to the lumped mass approximation of continuum mechanics. We concentrate on two different aspects of the source approximations. Although it has been reported that LSA does not modify the asymptotic h 2 convergence behaviour for linear elements, the effect of LSA on convergence of higher degree elements has not been investigated. Thus, we would be interested in determining, p, the asymptotic order of convergence, in: Δk |k eff (analytical) -k eff (finite element)| = Ch p (1) for finite element approximations of varying degree (N) with both of the source approximations. Since (1) is valid in the asymptotic limit, we must use ultra-fine meshes and quadruple precision arithmetic. For our order of convergence study, we used infinite cylindrical geometry with azimuthal symmetry. Hence, the effects of singularities remain uninvestigated. The second aspect we dwell on is the performance of LSA in bilinear 3-D finite element calculations, compared to CSA. LSA has been used quite extensively in 1- and 2-D even-parity transport and diffusion calculations. In this work, we will try to assess the relative merits of LSA and CSA in 3-D problems. (author)

  13. Hydrogen passivation of n+p and p+n heteroepitaxial InP solar cell structures

    Science.gov (United States)

    Chatterjee, B.; Ringel, S. A.; Hoffman, R., Jr.

    1995-01-01

    High-efficiency, heteroepitaxial (HE) InP solar cells, grown on GaAs, Si or Ge substrates, are desirable for their mechanically strong, light-weight and radiation-hard properties. However, dislocations, caused by lattice mismatch, currently limit the performance of the HE cells. This occurs through shunting paths across the active photovoltaic junction and by the formation of deep levels. In previous work we have demonstrated that plasma hydrogenation is an effective and stable means to passivate the electrical activity of dislocations in specially designed HE InP test structures. In this work, we present the first report of successful hydrogen passivation in actual InP cell structures grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD). We have found that a 2 hour exposure to a 13.56 MHz hydrogen plasma at 275 C reduces the deep level concentration in HE n+n InP cell structures from as-grown values of approximately 10(exp 15)/cm(exp -3), down to 1-2 x 10(exp 13)/cm(exp -3). The deep levels in the p-type base region of the cell structure match those of our earlier p-type test structures, which were attributed to dislocations or related point defect complexes. All dopants were successfully reactivated by a 400 C, 5 minute anneal with no detectable activation of deep levels. I-V analysis indicated a subsequent approximately 10 fold decrease in reverse leakage current at -1 volt reverse bias, and no change in the forward biased series resistance of the cell structure which indicates complete reactivation of the n+ emitter. Furthermore, electrochemical C-V profiling indicates greatly enhanced passivation depth, and hence hydrogen diffusion, for heteroepitaxial structures when compared with identically processed homoepitaxial n+p InP structures. An analysis of hydrogen diffusion in dislocated InP will be discussed, along with comparisons of passivation effectiveness for n+p versus p+n heteroepitaxial cell configurations. Preliminary hydrogen

  14. Pathophysiological Consequences of a Break in S1P1-Dependent Homeostasis of Vascular Permeability Revealed by S1P1 Competitive Antagonism.

    Science.gov (United States)

    Bigaud, Marc; Dincer, Zuhal; Bollbuck, Birgit; Dawson, Janet; Beckmann, Nicolau; Beerli, Christian; Fishli-Cavelti, Gina; Nahler, Michaela; Angst, Daniela; Janser, Philipp; Otto, Heike; Rosner, Elisabeth; Hersperger, Rene; Bruns, Christian; Quancard, Jean

    2016-01-01

    Homeostasis of vascular barriers depends upon sphingosine 1-phosphate (S1P) signaling via the S1P1 receptor. Accordingly, S1P1 competitive antagonism is known to reduce vascular barrier integrity with still unclear pathophysiological consequences. This was explored in the present study using NIBR-0213, a potent and selective S1P1 competitive antagonist. NIBR-0213 was tolerated at the efficacious oral dose of 30 mg/kg BID in the rat adjuvant-induced arthritis (AiA) model, with no sign of labored breathing. However, it induced dose-dependent acute vascular pulmonary leakage and pleural effusion that fully resolved within 3-4 days, as evidenced by MRI monitoring. At the supra-maximal oral dose of 300 mg/kg QD, NIBR-0213 impaired lung function (with increased breathing rate and reduced tidal volume) within the first 24 hrs. Two weeks of NIBR-0213 oral dosing at 30, 100 and 300 mg/kg QD induced moderate pulmonary changes, characterized by alveolar wall thickening, macrophage accumulation, fibrosis, micro-hemorrhage, edema and necrosis. In addition to this picture of chronic inflammation, perivascular edema and myofiber degeneration observed in the heart were also indicative of vascular leakage and its consequences. Overall, these observations suggest that, in the rat, the lung is the main target organ for the S1P1 competitive antagonism-induced acute vascular leakage, which appears first as transient and asymptomatic but could lead, upon chronic dosing, to lung remodeling with functional impairments. Hence, this not only raises the question of organ specificity in the homeostasis of vascular barriers, but also provides insight into the pre-clinical evaluation of a potential safety window for S1P1 competitive antagonists as drug candidates.

  15. Self-similar factor approximants

    International Nuclear Information System (INIS)

    Gluzman, S.; Yukalov, V.I.; Sornette, D.

    2003-01-01

    The problem of reconstructing functions from their asymptotic expansions in powers of a small variable is addressed by deriving an improved type of approximants. The derivation is based on the self-similar approximation theory, which presents the passage from one approximant to another as the motion realized by a dynamical system with the property of group self-similarity. The derived approximants, because of their form, are called self-similar factor approximants. These complement the obtained earlier self-similar exponential approximants and self-similar root approximants. The specific feature of self-similar factor approximants is that their control functions, providing convergence of the computational algorithm, are completely defined from the accuracy-through-order conditions. These approximants contain the Pade approximants as a particular case, and in some limit they can be reduced to the self-similar exponential approximants previously introduced by two of us. It is proved that the self-similar factor approximants are able to reproduce exactly a wide class of functions, which include a variety of nonalgebraic functions. For other functions, not pertaining to this exactly reproducible class, the factor approximants provide very accurate approximations, whose accuracy surpasses significantly that of the most accurate Pade approximants. This is illustrated by a number of examples showing the generality and accuracy of the factor approximants even when conventional techniques meet serious difficulties

  16. The role of sphingosine-1-phosphate (S1P) and ceramide-1-phosphate (C1P) in the trafficking of normal and malignant cells

    Science.gov (United States)

    Ratajczak, Mariusz Z.; Suszynska, Malwina; Borkowska, Sylwia; Ratajczak, Janina; Schneider, Gabriela

    2014-01-01

    Introduction A common feature of many types of cells is their responsiveness to chemotactic gradients of factors for which they express the corresponding receptors. The most studied chemoattractants so far are peptide-based growth factors and a family of cytokines endowed with strong chemotactic properties, called chemokines. However, additional evidence has accumulated that, in addition to these peptide-based chemoattractants, an important role in cell migration is played by bioactive lipids. Areas covered Solid evidence has accumulated that two bioactive phosphorylated sphingolipids that are derivatives of sphingolipid metabolism, namely sphingosine-1-phosphate (S1P) and ceramide-1-phosphate (C1P), are potent chemoattractants for a variety of cells. In this review, we will discuss the effect of these two phosphorylated sphingolipids on the trafficking of normal and malignant cells, and, in particular, we will focus on their role in trafficking of normal hematopoietic stem/progenitor cells. Unlike other mediators, S1P under steady state conditions maintain a steep gradient between interstitial fluid and peripheral blood and lymph across the endothelial barrier, which is important in the egress of cells from bone marrow. Both S1P and C1P may be upregulated in damaged tissues, which may result in reversal of this gradient. Expert opinion S1P and C1P are important regulators of the trafficking of normal and malignant cells, and modification of their biological effects will have important applications in optimizing stem cell mobilization and homing, tissue organ/regeneration, and preventing cancer metastasis. PMID:24188167

  17. Modulated Pade approximant

    International Nuclear Information System (INIS)

    Ginsburg, C.A.

    1980-01-01

    In many problems, a desired property A of a function f(x) is determined by the behaviour of f(x) approximately equal to g(x,A) as x→xsup(*). In this letter, a method for resuming the power series in x of f(x) and approximating A (modulated Pade approximant) is presented. This new approximant is an extension of a resumation method for f(x) in terms of rational functions. (author)

  18. Approximate Dynamic Programming: Combining Regional and Local State Following Approximations.

    Science.gov (United States)

    Deptula, Patryk; Rosenfeld, Joel A; Kamalapurkar, Rushikesh; Dixon, Warren E

    2018-06-01

    An infinite-horizon optimal regulation problem for a control-affine deterministic system is solved online using a local state following (StaF) kernel and a regional model-based reinforcement learning (R-MBRL) method to approximate the value function. Unlike traditional methods such as R-MBRL that aim to approximate the value function over a large compact set, the StaF kernel approach aims to approximate the value function in a local neighborhood of the state that travels within a compact set. In this paper, the value function is approximated using a state-dependent convex combination of the StaF-based and the R-MBRL-based approximations. As the state enters a neighborhood containing the origin, the value function transitions from being approximated by the StaF approach to the R-MBRL approach. Semiglobal uniformly ultimately bounded (SGUUB) convergence of the system states to the origin is established using a Lyapunov-based analysis. Simulation results are provided for two, three, six, and ten-state dynamical systems to demonstrate the scalability and performance of the developed method.

  19. Conjugation of nitrated acetaminophen to Der p1 amplifies peripheral blood monocyte response to Der p1.

    Directory of Open Access Journals (Sweden)

    Ryan G Thomas

    Full Text Available An association of acetaminophen use and asthma was observed in the International Study of Asthma and Allergies in Childhood study. However there are no clear mechanisms to explain an association between acetaminophen use and immunologic pathology. In acidic conditions like those in the stomach and inflamed airway, tyrosine residues are nitrated by nitrous and peroxynitrous acids. The resulting nitrotyrosine is structurally similar to 2,4-dinitrophenol and 2,4-dinitrochlorobenzene, known haptens that enhance immune responses by covalently binding proteins. Nitrated acetaminophen shares similar molecular structure.We hypothesized the acetaminophen phenol ring undergoes nitration under acidic conditions, producing 3-nitro-acetaminophen which augments allergic responses by acting as a hapten for environmental allergens.3-nitro-acetaminophen was formed from acetaminophen in the presence of acidified nitrite, purified by high performance liquid chromatography, and assayed by gas-chromatography mass spectrometry. Purified 3-nitro-acetaminophen was reacted with Dermatophagoides pteronyssinus (Der p1 and analyzed by mass spectrometry to identify the modification site. Human peripheral blood mononuclear cells proliferation response was measured in response to 3-nitro-acetaminophen and to 3-nitro-acetaminophen-modified Der p1.Acetaminophen was modified by nitrous acid forming 3-nitro-acetaminophen over a range of different acidic conditions consistent with airway inflammation and stomach acidity. The Der p1 protein-hapten adduct creation was confirmed by liquid chromatography-mass spectrometry proteomics modifying cysteine 132. Peripheral blood mononuclear cells exposed to 3-nitro-acetaminophen-modified Der p1 had increased proliferation and cytokine production compared to acetaminophen and Der p1 alone (n = 7; p < 0.05.These data suggests 3-nitro-acetaminophen formation and reaction with Der p1 provides a mechanism by which stomach acid or infection

  20. Approximate reflection coefficients for a thin VTI layer

    KAUST Repository

    Hao, Qi; Stovas, Alexey

    2017-01-01

    We present an approximate method to derive simple expressions for the reflection coefficients of P- and SV-waves for a thin transversely isotropic layer with a vertical symmetry axis (VTI) embedded in a homogeneous VTI background. The layer

  1. Semiclassical approximations for a momentum dependent one-body potential

    International Nuclear Information System (INIS)

    Dworzecka, M.; Moszkowski, S.A.

    1976-08-01

    Recently a semiclassical approximation was applied by Jennings, et al., for a system of noninteracting fermions in a local one-body potential. This is a way to calculate shell corrections alternative to Strutinsky's method. This method was generalized to a spherical but a momentum dependent potential of the form, V(r) + 1 / 2 (p 2 W(r) + W(r)p 2 ). Explicit expressions are developed for the number of particles and the smooth sum of single particle energies in terms of the Fermi energy and the one-body potential and its first two derivatives. They are calculated for selected values of the parameters and compared with the sum of single particle energies obtained by numerical solution of the Schroedinger equation. The difference between the two is evidently the shell correction

  2. Approximate number word knowledge before the cardinal principle.

    Science.gov (United States)

    Gunderson, Elizabeth A; Spaepen, Elizabet; Levine, Susan C

    2015-02-01

    Approximate number word knowledge-understanding the relation between the count words and the approximate magnitudes of sets-is a critical piece of knowledge that predicts later math achievement. However, researchers disagree about when children first show evidence of approximate number word knowledge-before, or only after, they have learned the cardinal principle. In two studies, children who had not yet learned the cardinal principle (subset-knowers) produced sets in response to number words (verbal comprehension task) and produced number words in response to set sizes (verbal production task). As evidence of approximate number word knowledge, we examined whether children's numerical responses increased with increasing numerosity of the stimulus. In Study 1, subset-knowers (ages 3.0-4.2 years) showed approximate number word knowledge above their knower-level on both tasks, but this effect did not extend to numbers above 4. In Study 2, we collected data from a broader age range of subset-knowers (ages 3.1-5.6 years). In this sample, children showed approximate number word knowledge on the verbal production task even when only examining set sizes above 4. Across studies, children's age predicted approximate number word knowledge (above 4) on the verbal production task when controlling for their knower-level, study (1 or 2), and parents' education, none of which predicted approximation ability. Thus, children can develop approximate knowledge of number words up to 10 before learning the cardinal principle. Furthermore, approximate number word knowledge increases with age and might not be closely related to the development of exact number word knowledge. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. On Nash-Equilibria of Approximation-Stable Games

    Science.gov (United States)

    Awasthi, Pranjal; Balcan, Maria-Florina; Blum, Avrim; Sheffet, Or; Vempala, Santosh

    One reason for wanting to compute an (approximate) Nash equilibrium of a game is to predict how players will play. However, if the game has multiple equilibria that are far apart, or ɛ-equilibria that are far in variation distance from the true Nash equilibrium strategies, then this prediction may not be possible even in principle. Motivated by this consideration, in this paper we define the notion of games that are approximation stable, meaning that all ɛ-approximate equilibria are contained inside a small ball of radius Δ around a true equilibrium, and investigate a number of their properties. Many natural small games such as matching pennies and rock-paper-scissors are indeed approximation stable. We show furthermore there exist 2-player n-by-n approximation-stable games in which the Nash equilibrium and all approximate equilibria have support Ω(log n). On the other hand, we show all (ɛ,Δ) approximation-stable games must have an ɛ-equilibrium of support O(Δ^{2-o(1)}/ɛ2{log n}), yielding an immediate n^{O(Δ^{2-o(1)}/ɛ^2log n)}-time algorithm, improving over the bound of [11] for games satisfying this condition. We in addition give a polynomial-time algorithm for the case that Δ and ɛ are sufficiently close together. We also consider an inverse property, namely that all non-approximate equilibria are far from some true equilibrium, and give an efficient algorithm for games satisfying that condition.

  4. Quantum approximate optimization algorithm for MaxCut: A fermionic view

    Science.gov (United States)

    Wang, Zhihui; Hadfield, Stuart; Jiang, Zhang; Rieffel, Eleanor G.

    2018-02-01

    Farhi et al. recently proposed a class of quantum algorithms, the quantum approximate optimization algorithm (QAOA), for approximately solving combinatorial optimization problems (E. Farhi et al., arXiv:1411.4028; arXiv:1412.6062; arXiv:1602.07674). A level-p QAOA circuit consists of p steps; in each step a classical Hamiltonian, derived from the cost function, is applied followed by a mixing Hamiltonian. The 2 p times for which these two Hamiltonians are applied are the parameters of the algorithm, which are to be optimized classically for the best performance. As p increases, parameter optimization becomes inefficient due to the curse of dimensionality. The success of the QAOA approach will depend, in part, on finding effective parameter-setting strategies. Here we analytically and numerically study parameter setting for the QAOA applied to MaxCut. For the level-1 QAOA, we derive an analytical expression for a general graph. In principle, expressions for higher p could be derived, but the number of terms quickly becomes prohibitive. For a special case of MaxCut, the "ring of disagrees," or the one-dimensional antiferromagnetic ring, we provide an analysis for an arbitrarily high level. Using a fermionic representation, the evolution of the system under the QAOA translates into quantum control of an ensemble of independent spins. This treatment enables us to obtain analytical expressions for the performance of the QAOA for any p . It also greatly simplifies the numerical search for the optimal values of the parameters. By exploring symmetries, we identify a lower-dimensional submanifold of interest; the search effort can be accordingly reduced. This analysis also explains an observed symmetry in the optimal parameter values. Further, we numerically investigate the parameter landscape and show that it is a simple one in the sense of having no local optima.

  5. Approximation properties of fine hyperbolic graphs

    Indian Academy of Sciences (India)

    2010 Mathematics Subject Classification. 46L07. 1. Introduction. Given a countable discrete group G, some nice approximation properties for the reduced. C∗-algebras C∗ r (G) can give us the approximation properties of G. For example, Lance. [7] proved that the nuclearity of C∗ r (G) is equivalent to the amenability of G; ...

  6. Total (p,n), (p,γ), (p,p'γ) and differential (p,p) cross-sections measurements for /sup 61,64/Ni

    International Nuclear Information System (INIS)

    Hershberger, R.L.; Gabbard, F.; Laird, C.E.

    1985-01-01

    Absolute total (p,n) and differential elastic (p,p) cross sections have been measured for /sup 61,64/Ni in the energy range of E/sub p/ = 2 to 7 MeV. The (p,γ) and (p,p'γ) cross sections were measured from as low an energy as feasible to approximately one MeV above the (p,n) threshold. Standard optical potentials have been used with a Hauser-Feshbach model to analyze the data. The adopted model values are used to deduce a total proton strength function which displays features of the 3s single particle resonance

  7. Influence of the p ¯ -p Nuclear Interaction on the Rate of the Low-Energy p ¯ + H μ → ( p ¯ p α + μ − Reaction

    Directory of Open Access Journals (Sweden)

    Renat A. Sultanov

    2018-04-01

    Full Text Available The influence of an additional strong p ¯ -p nuclear interaction in a three-charge-particle system with arbitrary masses is investigated. Specifically, the system of p ¯ , μ − , and p is considered in this paper, where p ¯ is an antiproton, μ − is a muon and p is a proton. A numerical computation in the framework of a detailed few-body approach is carried out for the following protonium (antiprotonic hydrogen formation three-body reaction: p ¯ + H μ ( 1 s → ( p ¯ p α + μ − . Here, H μ ( 1 s is a ground state muonic hydrogen, i.e., a bound state of p and μ − . A bound state of p and its antimatter counterpart p ¯ is a protonium atom in a quantum atomic state α , i.e., P n = ( p ¯ p α . The low-energy cross sections and rates of the P n formation reaction are computed in the framework of coupled Faddeev-Hahn-type equations. The strong p ¯ -p interaction is included in these calculations within a first order approximation. It was found, that the inclusion of the nuclear interaction results in a quite significant correction to the rate of the three-body reaction.

  8. The deexcitation of the Ar (3P2, 3p1 and 1P1) states as measured by absorption both in pure argon and in the presence of additives

    International Nuclear Information System (INIS)

    Dutuit, Odile

    1974-01-01

    The de-excitation of the 3 P 2 , 3 p 1 and 1 P 1 states of argon was studied in pure argon between 10 and 200 torr and in Ar + CO and Ar + H 2 mixtures. These states are populated after excitation of the gas by a short (20 ns) pulse of 500 keV electrons (FEBETRON). Under our experimental conditions, the relation between the measured optical density of the lines studied and the concentration of absorbing species was found to be: DO = log I 0 /I ∝ (lC) n with n = 0,4. The three body rate constants k 2 were measured for the two resonant states 3 p 1 (k 2 = (1,65 ± 0,3) x 10 -32 cm 6 s -1 ) and 1 P 1 (k 2 = (1,0 ± 0,2) x 10 -32 cm 6 s -1 ); they had not been considered in previous low pressure studies. For the metastable state 3 P 2 , the measured value of k 2 ((1,6 ± 0,3) x 10 -32 cm 6 s -1 ) is in good agreement with those found in the literature. However, our two body rate constant k 1 is about ten times higher than that found in measurements at low pressure. This difference could be due to a collision-induced emission process at high pressure. The rate constants for the quenching by CO and H 2 were measured for the metastable state 3 P 2 (1,85 and 10,5 x 10 -11 cm 3 s -1 ) and for the resonant states 3 P 1 (4,5 and 20 x 10 -11 cm 3 s -1 ) and 1 P 1 (8,5 and 33 X 10 -11 cm 3 s -1 ). Comparison of the de-excitation cross sections of resonant and metastable states should lead to a better understanding of energy transfer processes from these latter. (author) [fr

  9. Approximate maximum parsimony and ancestral maximum likelihood.

    Science.gov (United States)

    Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

    2010-01-01

    We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

  10. Approximation of Corrected Calcium Concentrations in Advanced Chronic Kidney Disease Patients with or without Dialysis Therapy

    Directory of Open Access Journals (Sweden)

    Yoshio Kaku

    2015-08-01

    Full Text Available Background: The following calcium (Ca correction formula (Payne is conventionally used for serum Ca estimation: corrected total Ca (TCa (mg/dl = TCa (mg/dl + [4 - albumin (g/dl]; however, it is inapplicable to advanced chronic kidney disease (CKD patients. Methods: 1,922 samples in CKD G4 + G5 patients and 341 samples in CKD G5D patients were collected. Levels of TCa (mg/day, ionized Ca2+ (iCa2+ (mmol/l and other clinical parameters were measured. We assumed the corrected TCa to be equal to eight times the iCa2+ value (measured corrected TCa. We subsequently performed stepwise multiple linear regression analysis using the clinical parameters. Results: The following formula was devised from multiple linear regression analysis. For CKD G4 + G5 patients: approximated corrected TCa (mg/dl = TCa + 0.25 × (4 - albumin + 4 × (7.4 - pH + 0.1 × (6 - P + 0.22. For CKD G5D patients: approximated corrected TCa (mg/dl = TCa + 0.25 × (4 - albumin + 0.1 × (6 - P + 0.05 × (24 - HCO3- + 0.35. Receiver operating characteristic analysis showed the high values of the area under the curve of approximated corrected TCa for the detection of measured corrected TCa ≥8.4 mg/dl and ≤10.4 mg/dl for each CKD sample. Both intraclass correlation coefficients for each CKD sample demonstrated superior agreement using the new formula compared to the previously reported formulas. Conclusion: Compared to other formulas, the approximated corrected TCa values calculated from the new formula for patients with CKD G4 + G5 and CKD G5D demonstrates superior agreement with the measured corrected TCa.

  11. Wolf-Hirschhorn (4p-) syndrome: prenatal diagnosis, molecular cytogenetic characterization and association with a 1.2-Mb microduplication at 8p22-p21.3 and a 1.1-Mb microduplication at 10p15.3 in a fetus with an apparently pure 4p deletion.

    Science.gov (United States)

    Chen, Chih-Ping; Su, Yi-Ning; Chen, Yi-Yung; Su, Jun-Wei; Chern, Schu-Rern; Chen, Yu-Ting; Chen, Wen-Lin; Chen, Li-Feng; Wang, Wayseen

    2011-12-01

    To present prenatal diagnosis and molecular cytogenetic characterization of Wolf-Hirschhorn syndrome (WHS) associated with microduplications at 8p and 10p in a fetus with an apparently pure 4p deletion. A 35-year-old gravida 2, para 1 woman underwent amniocentesis at 18 weeks of gestation because of advanced maternal age. Her husband was 38 years of age. There was no family history of congenital malformations. Amniocentesis revealed a karyotype of 46,XY,del(4p16.1). The parental karyotypes were normal. Array comparative genomic hybridization (aCGH) analysis revealed a 6.5-Mb deletion at 4p16.3-p16.1, a 1.2-Mb microduplication at 8p22-p21.3, and a 1.1-Mb microduplication at 10p15.3, or arr cgh 4p16.3p16.1 (0-6,531,998 bp)×1, 8p22p21.3 (18,705,388-19,940,445 bp)×3, 10p15.3 (0-1,105,065 bp)×3. Polymorphic DNA marker analysis confirmed a paternal origin of 4p deletion. Prenatal ultrasound revealed facial dysmorphism and hypospadias. The aCGH analysis of the parents revealed no genomic imbalance. Fluorescence in situ hybridization study showed an unbalanced reciprocal translocation between chromosomes 4 and 10 at bands 4p16.1 and 10p15.3. The cytogenetic result, thus, was 46,XY,der(4)t(4;10)(p16.1;p15.3),dup(8)(p21.3p22). The parents elected to terminate the pregnancy, and a 470-g malformed fetus was delivered. The present case provides evidence that an apparently pure 4p deletion can be associated with subtle chromosome imbalances in other chromosomes. Copyright © 2011. Published by Elsevier B.V.

  12. Randomizing quantum states to Shatten p -norm for all p1

    International Nuclear Information System (INIS)

    Jeong, Kabgyun

    2014-01-01

    We formularize a method for randomizing quantum states with respect to the Shatten p-norms (p1) in trace class. In particular, this work includes the operator norm, p = ∞, and the trace norm, p = 1, simultaneously in a single statement via McDiarmid's inequality and a net construction

  13. Quasi-fractional approximation to the Bessel functions

    International Nuclear Information System (INIS)

    Guerrero, P.M.L.

    1989-01-01

    In this paper the authors presents a simple Quasi-Fractional Approximation for Bessel Functions J ν (x), (- 1 ≤ ν < 0.5). This has been obtained by extending a method published which uses simultaneously power series and asymptotic expansions. Both functions, exact and approximated, coincide in at least two digits for positive x, and ν between - 1 and 0,4

  14. Moments of the Spin Structure Functions g1p and g1d for 0.05 < Q2 < 3.0 GeV2

    Energy Technology Data Exchange (ETDEWEB)

    Prok, Yelena; Bosted, Peter; Burkert, Volker; Deur, Alexandre; Dharmawardane, Kahanawita; Dodge, Gail; Griffioen, Keith; Kuhn, Sebastian; Minehart, Ralph; Adams, Gary; Amaryan, Moscov; Amaryan, Moskov; Anghinolfi, Marco; Asryan, G.; Audit, Gerard; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Baillie, Nathan; Ball, J.P.; Ball, Jacques; Baltzell, Nathan; Barrow, Steve; Battaglieri, Marco; Beard, Kevin; Bedlinskiy, Ivan; Bektasoglu, Mehmet; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Biselli, Angela; Blaszczyk, Lukasz; Boyarinov, Sergey; Bonner, Billy; Bouchigny, Sylvain; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Bultmann, S.; Bueltmann, Stephen; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Casey, Liam; Cazes, Antoine; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Cords, Dieter; Corvisiero, Pietro; Crabb, Donald; Crede, Volker; Cummings, John; Dale, Daniel; Dashyan, Natalya; De Masi, Rita; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Denizli, Haluk; Dennis, Lawrence; Dhuga, Kalvir; Dickson, Richard; Djalali, Chaden; Doughty, David; Dugger, Michael; Dytman, Steven; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fatemi, Renee; Fedotov, Gleb; Feldman, Gerald; Fersch, Robert; Feuerbach, Robert; Forest, Tony; Fradi, Ahmed; Funsten, Herbert; Garcon, Michel; Gavalian, Gagik; Gevorgyan, Nerses; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Golovach, Evgeny; Gothe, Ralf; Guidal, Michel; Guillo, Matthieu; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hadjidakis, Cynthia; Hafidi, Kawtar; Hakobyan, Hayk; Hanretty, Charles; Hardie, John; Hassall, Neil; Heddle, David; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Huertas, Marco; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Keith, Christopher; Kellie, James; Khandaker, Mahbubul; Kim, Kui; Kim, Kyungmo; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Klusman, Mike; Kossov, Mikhail; Krahn, Zebulun; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuleshov, Sergey; Kuznetsov, Viacheslav; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, Dave; Lima, Ana; Livingston, Kenneth; Lu, Haiyun; Lukashin, K.; MacCormick, Marion; Marchand, Claude; Markov, Nikolai; Mattione, Paul; McAleer, Simeon; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Morand, Ludyvine; Moreno, Brahim; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Mueller, James; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Nasseripour, Rakhsha; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; O' Rielly, Grant; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kijun; Pasyuk, Evgueni; Paterson, Craig; Anefalos Pereira, S.; Philips, Sasha; Pierce, J.; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Popa, Iulian; Pozdnyakov, Sergey; Preedom, Barry; Price, John; Procureur, Sebastien; Protopopescu, Dan; Qin, Liming; Raue, Brian; Riccardi, Gregory; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Rosner, Guenther; Rossi, Patrizia; Rowntree, David; Rubin, Philip; Sabatie, Franck; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schumacher, Reinhard; Seely, Mikell; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shaw, Jeffrey; Shvedunov, Nikolay; Skabelin, Alexander; Smith, Elton; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinskiy, Aleksey; Stepanyan, Samuel; Stepanyan, Stepan; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Suleiman, Riad; Taiuti, Mauro; Tedeschi, David; Tkabladze, Avtandil; Tkachenko, Svyatoslav; Todor, Luminita; Ungaro, Maurizio; V

    2009-02-01

    The spin structure functions $g_1$ for the proton and the deuteron have been measured over a wide kinematic range in $x$ and \\Q2 using 1.6 and 5.7 GeV longitudinally polarized electrons incident upon polarized NH$_3$ and ND$_3$ targets at Jefferson Lab. Scattered electrons were detected in the CEBAF Large Acceptance Spectrometer, for $0.05 < Q^2 < 5 $\\ GeV$^2$ and $W < 3$ GeV. The first moments of $g_1$ for the proton and deuteron are presented -- both have a negative slope at low \\Q2, as predicted by the extended Gerasimov-Drell-Hearn sum rule. The first result for the generalized forward spin polarizability of the proton $\\gamma_0^p$ is also reported, and shows evidence of scaling above $Q^2$ = 1.5 GeV$^2$. Although the first moments of $g_1$ are consistent with Chiral Perturbation Theory (\\ChPT) calculations up to approximately $Q^2 = 0.06$ GeV$^2$, a significant discrepancy is observed between the $\\gamma_0^p$ data and \\ChPT\\ for $\\gamma_0^p$,even at the lowest \\Q2.

  15. Transcription factors Asg1p and Hal9p regulate pH homeostasis in Candida glabrata

    Directory of Open Access Journals (Sweden)

    Jing eWu

    2015-08-01

    Full Text Available Candida glabrata is an important microorganism used in commercial fermentation to produce pyruvate, but very little is known about its mechanisms for surviving acid stress in culture. In this study, it was shown that transcription factors Asg1p and Hal9p play essential roles in C. glabrata in the tolerance of acid stress, as the deletion of CgASG1 or CgHAL9 resulted in the inability to survive in an acidic environment. Cgasg1 and Cghal9 mutant strains are unable to maintain pH homeostasis, as evidenced by a decrease in intracellular pH and an increase in reactive oxygen species production, which results in metabolic disorders. The results showed that intracellular acidification was partly due to the diminished activity of the plasma membrane proton pump, CgPma1p. In addition, transcriptome sequencing revealed that Cgasg1 and Cghal9 mutant strains displayed a variety of changes in gene expression under acidic conditions, including genes in the MAPK signaling pathway, plasma membrane or cell wall organization, trehalose accumulation, and the RIM101 signaling pathway. Lastly, quantitative reverse-transcribed PCR and cellular localization showed that CgAsg1p and CgHal9p played independent roles in response to acid stress.

  16. Evaluation of P availability from Fe and A1 labelled (32P) phosphates

    International Nuclear Information System (INIS)

    Bittencourt, V.S.

    1975-07-01

    Synthetically Fe and A1 labelled phosphates ( 32 P) show a certain amount of available P to the plants when applied to Sao Paulo State soils. This availability decreases from considered amorphous A1-phosphate (A1-P sub(am)) to A1 phosphate with a certain cristalinity grade (A1-P sub(cr)) and than from this to Fe-P sub(am) followed by Fe-P sub(cr), and it is influenced by both the soil characteristics and mainly by the iron constituents of the samples. In this way, one can not expect that the 0,05 N 2 H SO 4 and the CHANG and JACKSON (1957a) solutions can define properly the available P of these soils. The addition of lime to the soils do not drive to a better P absorption by the plants and its effects are dubious

  17. Finite difference approximation of control via the potential in a 1-D Schrodinger equation

    Directory of Open Access Journals (Sweden)

    K. Kime

    2000-04-01

    Full Text Available We consider the problem of steering given initial data to given terminal data via a time-dependent potential, the control, in a 1-D Schrodinger equation. We determine a condition for existence of a transferring potential within our approximation. Using Maple, we give equations for the control and also examples in which the potential is restricted to be centralized and to be a step potential.

  18. Semiclassical initial value approximation for Green's function.

    Science.gov (United States)

    Kay, Kenneth G

    2010-06-28

    A semiclassical initial value approximation is obtained for the energy-dependent Green's function. For a system with f degrees of freedom the Green's function expression has the form of a (2f-1)-dimensional integral over points on the energy surface and an integral over time along classical trajectories initiated from these points. This approximation is derived by requiring an integral ansatz for Green's function to reduce to Gutzwiller's semiclassical formula when the integrations are performed by the stationary phase method. A simpler approximation is also derived involving only an (f-1)-dimensional integral over momentum variables on a Poincare surface and an integral over time. The relationship between the present expressions and an earlier initial value approximation for energy eigenfunctions is explored. Numerical tests for two-dimensional systems indicate that good accuracy can be obtained from the initial value Green's function for calculations of autocorrelation spectra and time-independent wave functions. The relative advantages of initial value approximations for the energy-dependent Green's function and the time-dependent propagator are discussed.

  19. Meiotic and pedigree segregation analyses in carriers of t(4;8)(p16;p23.1) differing in localization of breakpoint positions at 4p subband 4p16.3 and 4p16.1.

    Science.gov (United States)

    Midro, Alina T; Zollino, Marcella; Wiland, Ewa; Panasiuk, Barbara; Iwanowski, Piotr S; Murdolo, Marina; Śmigiel, Robert; Sąsiadek, Maria; Pilch, Jacek; Kurpisz, Maciej

    2016-02-01

    The purpose of this study was to compare meiotic segregation in sperm cells from two carriers with t(4;8)(p16;p23.1) reciprocal chromosome translocations (RCTs), differing in localization of the breakpoint positions at the 4p subband-namely, 4p16.3 (carrier 1) and 4p16.1 (carrier 2)-and to compare data of the pedigree analyses performed by direct method. Three-color fluorescent in situ hybridization (FISH) on sperm cells and FISH mapping for the evaluation of the breakpoint positions, data from pedigrees, and direct segregation analysis of the pedigrees were performed. Similar proportions of normal/balanced and unbalanced sperm cells were found in both carriers. The most common was an alternate type of segregation (about 52 % and about 48 %, respectively). Unbalanced adjacent I and adjacent II karyotypes were found in similar proportions about 15 %. The direct segregation analysis (following Stengel-Rutkowski) of the pedigree of carriers of t(4;8)(p16.1;p23.1) was performed and results were compared with the data of the pedigree segregation analysis obtained earlier through the indirect method. The probability of live-born progeny with unbalanced karyotype for carriers of t(4;8)(p16.1;p23.1) was moderately high at 18.8 %-comparable to the value obtained using the indirect method for the same carriership, which was 12 %. This was, however, markedly lower than the value of 41.2 % obtained through the pedigree segregation indirect analysis estimated for carriers of t(4;8)(p16.3;p23.1), perhaps due to the unique composition of genes present within the 4p16.1-4p 16.3 region. Revealed differences in pedigree segregation analysis did not correspond to the very similar profile of meiotic segregation patterns presented by carrier 1 and carrier 2. Most probably, such discordances may be due to differences in embryo survival rates arising from different genetic backgrounds.

  20. Interaction of integrin β4 with S1P receptors in S1P- and HGF-induced endothelial barrier enhancement.

    Science.gov (United States)

    Ni, Xiuqin; Epshtein, Yulia; Chen, Weiguo; Zhou, Tingting; Xie, Lishi; Garcia, Joe G N; Jacobson, Jeffrey R

    2014-06-01

    We previously reported sphingosine 1-phosphate (S1P) and hepatocyte growth factor (HGF) augment endothelial cell (EC) barrier function and attenuate murine acute lung inury (ALI). While the mechanisms underlying these effects are not fully understood, S1P and HGF both transactivate the S1P receptor, S1PR1 and integrin β4 (ITGB4) at membrane caveolin-enriched microdomains (CEMs). In the current study, we investigated the roles of S1PR2 and S1PR3 in S1P/HGF-mediated EC signaling and their associations with ITGB4. Our studies confirmed ITGB4 and S1PR2/3 are recruited to CEMs in human lung EC in response to either S1P (1 µM, 5 min) or HGF (25 ng/ml, 5 min). Co-immunoprecipitation experiments identified an S1P/HGF-mediated interaction of ITGB4 with both S1PR2 and S1PR3. We then employed an in situ proximity ligation assay (PLA) to confirm a direct ITGB4-S1PR3 association induced by S1P/HGF although a direct association was not detectable between S1PR2 and ITGB4. S1PR1 knockdown (siRNA), however, abrogated S1P/HGF-induced ITGB4-S1PR2 associations while there was no effect on ITGB4-S1PR3 associations. Moreover, PLA confirmed a direct association between S1PR1 and S1PR2 induced by S1P and HGF. Finally, silencing of S1PR2 significantly attenuated S1P/HGF-induced EC barrier enhancement as measured by transendothelial resistance while silencing of S1PR3 significantly augmented S1P/HGF-induced barrier enhancement. These results confirm an important role for S1PR2 and S1PR3 in S1P/HGF-mediated EC barrier responses that are associated with their complex formation with ITGB4. Our findings elucidate novel mechanisms of EC barrier regulation that may ultimately lead to new therapeutic targets for disorders characterized by increased vascular permeability including ALI. © 2013 Wiley Periodicals, Inc.

  1. Approximation of the semi-infinite interval

    Directory of Open Access Journals (Sweden)

    A. McD. Mercer

    1980-01-01

    Full Text Available The approximation of a function f∈C[a,b] by Bernstein polynomials is well-known. It is based on the binomial distribution. O. Szasz has shown that there are analogous approximations on the interval [0,∞ based on the Poisson distribution. Recently R. Mohapatra has generalized Szasz' result to the case in which the approximating function is αe−ux∑k=N∞(uxkα+β−1Γ(kα+βf(kαuThe present note shows that these results are special cases of a Tauberian theorem for certain infinite series having positive coefficients.

  2. Muonic-hydrogen molecular bound states, quasibound states, and resonances in the Born-Oppenheimer approximation

    International Nuclear Information System (INIS)

    Jackson, J.D.

    1994-01-01

    The Born-Oppenheimer approximation is used as an exploratory tool to study bound states, quasibound states, and scattering resonances in muon (μ)--hydrogen (x)--hydrogen (y) molecular ions. Our purpose is to comment on the existence and nature of the narrow states reported in three-body calculations, for L=0 and 1, at approximately 55 eV above threshold and the family of states in the same partial waves reported about 1.9 keV above threshold. We first discuss the motivation for study of excited states beyond the well-known and well-studied bound states. Then we reproduce the energies and other properties of these well-known states to show that, despite the relatively large muon mass, the Born-Oppenheimer approximation gives a good, semiquantitative description containing all the essential physics. Born-Oppenheimer calculations of the s- and p-wave scattering of d-(dμ), d-(tμ), and t-(tμ) are compared with the accurate three-body results, again with general success. The places of disagreement are understood in terms of the differences in location of slightly bound (or unbound) states in the Born-Oppenheimer approximation compared to the accurate three-body calculations

  3. Deletion of P2 promoter of GJB1 gene a cause of Charcot-Marie-Tooth disease.

    Science.gov (United States)

    Kulshrestha, R; Burton-Jones, S; Antoniadi, T; Rogers, M; Jaunmuktane, Z; Brandner, S; Kiely, N; Manuel, R; Willis, T

    2017-08-01

    X-linked Charcot-Marie-Tooth disease (CMT) is the second most common cause of CMT, and is usually caused by mutations in the gap junction protein beta 1 (GJB1) gene. This gene has nerve specific P2 promoter that work synergistically with SOX10 and EGR2 genes to initiate transcription. Mutation in this region is known to cause Schwann cell dysfunction. A single large family of X linked peripheral neuropathy was identified in our practice. Next generation sequencing for targeted panel assay identified an upstream exon-splicing deletion identified extending from nucleotide c.-5413 to approximately - c.-49. This matches the sequence of 32 nucleotides at positions c.*218-*249 in the 3'UTR downstream of the GJB1 gene. The deleted fragment included the entire P2 promoter region. The deletion segregated with the disease. To our knowledge a deletion of the P2 promoter alone as a cause of CMT has not been reported previously. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Subtracting a best rank-1 approximation may increase tensor rank

    NARCIS (Netherlands)

    Stegeman, Alwin; Comon, Pierre

    2010-01-01

    It has been shown that a best rank-R approximation of an order-k tensor may not exist when R >= 2 and k >= 3. This poses a serious problem to data analysts using tensor decompositions it has been observed numerically that, generally, this issue cannot be solved by consecutively computing and

  5. Delta-function Approximation SSC Model in 3C 273 S. J. Kang1 ...

    Indian Academy of Sciences (India)

    Abstract. We obtain an approximate analytical solution using δ approximate calculation on the traditional one-zone synchrotron self-. Compton (SSC) model. In this model, we describe the electron energy distribution by a broken power-law function with a sharp cut-off, and non- thermal photons are produced by both ...

  6. Infection with E1B-mutant adenovirus stabilizes p53 but blocks p53 acetylation and activity through E1A

    DEFF Research Database (Denmark)

    Savelyeva, I.; Dobbelstein, M.

    2011-01-01

    to the suppression of p21 transcription. Depending on the E1A conserved region 3, E1B-defective adenovirus impaired the ability of the transcription factor Sp1 to bind the p21 promoter. Moreover, the amino terminal region of E1A, binding the acetyl transferases p300 and CREB-binding protein, blocked p53 K382...... accumulation of p53, without obvious defects in p53 localization, phosphorylation, conformation and oligomerization. Nonetheless, p53 completely failed to induce its target genes in this scenario, for example, p21/CDKN1A, Mdm2 and PUMA. Two regions of the E1A gene products independently contributed...... acetylation in infected cells. Mutating either of these E1A regions, in addition to E1B, partially restored p21 mRNA levels. Our findings argue that adenovirus attenuates p53-mediated p21 induction, through at least two E1B-independent mechanisms. Other virus species and cancer cells may employ analogous...

  7. Energy quantization for approximate H-surfaces and applications

    Directory of Open Access Journals (Sweden)

    Shenzhou Zheng

    2013-07-01

    Full Text Available We consider weakly convergent sequences of approximate H-surface maps defined in the plane with their tension fields bounded in $L^p$ for p> 4/3, and establish an energy quantization that accounts for the loss of their energies by the sum of energies over finitely many nontrivial bubbles maps on $mathbb{R}^2$. As a direct consequence, we establish the energy identity at finite singular time to their H-surface flows.

  8. Exploring the ϒ (4 S ,5 S ,6 S )→hb(1 P )η hidden-bottom hadronic transitions

    Science.gov (United States)

    Zhang, Yawei; Li, Gang

    2018-01-01

    Recently, the Belle Collaboration has reported the measurement of the spin-flipping transition ϒ (4 S )→hb(1 P )η with an unexpectedly large branching ratio: B (ϒ (4 S )→hb(1 P )η )=(2.18 ±0.11 ±0.18 )×10-3 . Such a large branching fraction contradicts with the anticipated suppression for the spin flip. In this work, we examine the effects induced by intermediate bottomed meson loops and point out that these effects are significantly important. Using the effective Lagrangian approach (ELA), we find the experimental data on ϒ (4 S )→hb(1 P )η can be accommodated with the reasonable inputs. We then explore the decays ϒ (5 S ,6 S )→hb(1 P )η and find that these two channels also have sizable branching fractions. We also calculate these processes in the framework of nonrelativistic effective field theory (NREFT). For the decays ϒ (4 S )→hb(1 P )η , the NREFT results are at the same order of magnitude but smaller than the ELA results by a factor of 2 to 5. For the decays ϒ (5 S ,6 S )→hb(1 P )η , the NREFT results are smaller than the ELA results by approximately 1 order of magnitude. We suggest a future experiment Belle-II to search for the ϒ (5 S ,6 S )→hb(1 P )η decays, which will be helpful for understanding the transition mechanism.

  9. Magnetic properties of Zn(P/sub x/As/sub 1-x/)2 alloys

    International Nuclear Information System (INIS)

    Vitkina, T.Z.; Smolyarenko, E.M.; Trukhan, V.M.

    1987-01-01

    The authors study the magnetic properties of Zn(P/sub x/As/sub 1-x/) 2 alloys. The concentration-dependent magnetic susceptibility of these alloys is shown, as is the temperature dependence of the magnetic susceptibility in solid solutions of the alloys. The diamagnetic susceptibility associated with the valence electrons displays a marked change for a transition to the bound state inasmuch as the valence electrons constitute the chemical bonding in the crystal. The diamagnetic component of the susceptibility of the valence electrons is calculated according to the MO LCAO approximation on the assumption that there is sp 3 -hybridization of the atomic wave function

  10. On function classes related pertaining to strong approximation of double Fourier series

    Science.gov (United States)

    Baituyakova, Zhuldyz

    2015-09-01

    The investigation of embedding of function classes began a long time ago. After Alexits [1], Leindler [2], and Gogoladze[3] investigated estimates of strong approximation by Fourier series in 1965, G. Freud[4] raised the corresponding saturation problem in 1969. The list of the authors dealing with embedding problems partly is also very long. It suffices to mention some names: V. G. Krotov, W. Lenski, S. M. Mazhar, J. Nemeth, E. M. Nikisin, K. I. Oskolkov, G. Sunouchi, J. Szabados, R. Taberski and V. Totik. Study on this topic has since been carried on over a decade, but it seems that most of the results obtained are limited to the case of one dimension. In this paper, embedding results are considered which arise in the strong approximation by double Fourier series. We prove theorem on the interrelation between the classes Wr1,r2HS,M ω and H(λ, p, r1, r2, ω(δ1, δ2)), in the one-dimensional case proved by L. Leindler.

  11. Population pharmacokinetics and pharmacodynamics of ponesimod, a selective S1P1 receptor modulator.

    Science.gov (United States)

    Krause, Andreas; Brossard, Patrick; D'Ambrosio, Daniele; Dingemanse, Jasper

    2014-06-01

    Ponesimod (ACT-128800), a reversible, orally active, selective S1P1 receptor modulator, prevents the egress of lymphocytes from the lymph node into the systemic circulation. It is currently in clinical development for the treatment of relapsing multiple sclerosis. Modulation of circulating lymphocytes serves as biomarker of efficacy and safety, such that the quantitative characterization of the pharmacokinetic/pharmacodynamic (PK/PD) relationship guides the clinical development of the compound. The availability of a variety of doses, dosing regimens, and treatment durations permitted estimation of the pharmacokinetics characterized by an absorption lag time followed by a sequential zero/first-order absorption and two compartments with first-order elimination. The PD are modeled as an indirect-effect model with rates of appearance and disappearance of lymphocytes in blood with a circadian rhythm and a drug effect on the rate of appearance. The model suggests a circadian variation of 9% and a maximum inhibition of 86% of total lymphocyte count with high doses at steady state. It was instrumental for the selection of doses for subsequent studies that confirmed the effect plateau in total lymphocyte count at approximately 0.5 × 10(9) counts/L.

  12. Effective nucleon-nucleon t matrix in the (p,2p) reaction

    International Nuclear Information System (INIS)

    Kudo, Y.; Kanayama, N.; Wakasugi, T.

    1989-01-01

    The cross sections and the analyzing powers for the /sup 40/Ca(p-arrow-right,2p) reactions at E/sub p/ = 76.1, 101.3, and 200 MeV are calculated in the distorted-wave impulse approximation using the Love-Franey effective nucleon-nucleon interaction. It is shown that the calculated individual contributions of the central, spin-orbit, and tensor parts in the Love-Franey interaction to the cross sections and the analyzing powers strongly depend on the incident proton energies. The spectroscopic factors extracted are consistent with the other reaction studies

  13. Hydrogen atom with a Yukawa potential: Perturbation theory and continued-fractions--Pade approximants at large order

    International Nuclear Information System (INIS)

    Vrscay, E.R.

    1986-01-01

    A simple power-series method is developed to calculate to large order the Rayleigh-Schroedinger perturbation expansions for energy levels of a hydrogen atom with a Yukawa-type screened Coulomb potential. Perturbation series for the 1s, 2s, and 2p levels, shown not to be of the Stieltjes type, are calculated to 100th order. Nevertheless, the poles of the Pade approximants to these series generally avoid the region of the positive real axis 0 < lambda < lambda(, where lambda( represents the coupling constant threshold. As a result, the Pade sums afford accurate approximations to E(lambda) in this domain. The continued-fraction representations to these perturbation series have been accurately calculated to large (100th) order and demonstrate a curious ''quasioscillatory,'' but non-Stieltjes, behavior. Accurate values of E(lambda) as well as lambda( for the 1s, 2s, and 2p levels are reported

  14. Roles of sphingosine-1-phosphate (S1P) receptors in malignant behavior of glioma cells. Differential effects of S1P2 on cell migration and invasiveness

    International Nuclear Information System (INIS)

    Young, Nicholas; Van Brocklyn, James R.

    2007-01-01

    Sphingosine-1-phosphate (S1P) is a bioactive lipid that signals through a family of five G-protein-coupled receptors, termed S1P 1-5 . S1P stimulates growth and invasiveness of glioma cells, and high expression levels of the enzyme that forms S1P, sphingosine kinase-1, correlate with short survival of glioma patients. In this study we examined the mechanism of S1P stimulation of glioma cell proliferation and invasion by either overexpressing or knocking down, by RNA interference, S1P receptor expression in glioma cell lines. S1P 1 , S1P 2 and S1P 3 all contribute positively to S1P-stimulated glioma cell proliferation, with S1P 1 being the major contributor. Stimulation of glioma cell proliferation by these receptors correlated with activation of ERK MAP kinase. S1P 5 blocks glioma cell proliferation, and inhibits ERK activation. S1P 1 and S1P 3 enhance glioma cell migration and invasion. S1P 2 inhibits migration through Rho activation, Rho kinase signaling and stress fiber formation, but unexpectedly, enhances glioma cell invasiveness by stimulating cell adhesion. S1P 2 also potently enhances expression of the matricellular protein CCN1/Cyr61, which has been implicated in tumor cell adhesion, and invasion as well as tumor angiogenesis. A neutralizing antibody to CCN1 blocked S1P 2 -stimulated glioma invasion. Thus, while S1P 2 decreases glioma cell motility, it may enhance invasion through induction of proteins that modulate glioma cell interaction with the extracellular matrix

  15. J/sub z/-conserving coupled states approximation: Magnetic transitions and angular distributions in rotating and fixed frames

    International Nuclear Information System (INIS)

    Kouri, D.J.; Shimoni, Y.

    1977-01-01

    Recently Shimoni and Kouri have pointed out that a careful treatment of j/sub z/-conserving coupled states (CS) approximation results in a body frame T-matrix T/sup J/(jlambdavertical-barj 0 lambda 0 ) which is not diagonal in lambda,lambda 0 . In addition they have shown that previous investigations of the CS did not optimally identify body frame T-matrix. In this paper, we explore the consequences of these observations. The exact T-matrix is obtained in the R- and P-helicity frames, as well as in an uncoupled spaceframe (USF) representation. The resulting exact expressions for these T-matrices are in terms of certain integrals, I/sup J//sub l/(jlambdavertical-barj 0 lambda 0 ), introduced earlier by Shimoni and Kouri. By obtaining CS approximation to these integrals, we are able to derive the preferred CS approximation in the R- and P-helicity and USF representations. We then employ the resulting CS T-matrices to derive the differential scattering amplitude and cross section in the various possible reference frames. The result is a unified treatment of these quantities. We are then able to demonstrate the equivalence of the CS approximation to the R- and P-helicity amplitudes. In addition, we show explicitly that the CS approximate degeneracy averaged differential cross section is frame independent. The CS approximation to the USF equation provides a rigorous basis for the original derivation of the CS method as given by McGuire and Kouri. In particular, our treatment shows that when the L 2 operator is approximated by an eigenvalue form l (l+1) h 2 (as was suggested first by McGuire and Kouri), there is no longer any difference between the BF and USF in the dynamical equations (for the wavefunction or amplitude density). Any differences are strictly kinematic in origin, and are the source of the lambda transitions which occur in the BF CS approximation. In the USF, there are no magnetic transitions in the CS approximation

  16. Distinct roles of two ceramide synthases, CaLag1p and CaLac1p, in the morphogenesis of Candida albicans

    DEFF Research Database (Denmark)

    Cheon, Seon Ah; Bal, Jyotiranjan; Song, Yunkyoung

    2012-01-01

    p) and Lac1p (CaLac1p) are functionally distinct. Lack of CaLag1p, but not CaLac1p, caused severe defects in the growth and hyphal morphogenesis of C. albicans. Deletion of CaLAG1 decreased expression of the hypha-specific HWP1 and ECE1 genes. Moreover, overexpression of CaLAG1 induced pseudohyphal...... growth in this organism under non-hypha-inducing conditions, suggesting that CaLag1p is necessary for relaying signals to induce hypha-specific gene expression. Analysis of ceramide and sphingolipid composition revealed that CaLag1p predominantly synthesizes ceramides with C24:0/C26:0 fatty acid moieties...

  17. Edaravone prevents neurotoxicity of mutant L166P DJ-1 in Parkinson's disease.

    Science.gov (United States)

    Li, Bing; Yu, Dawei; Xu, Zhiying

    2013-10-01

    Parkinson's disease (PD), which is estimated to affect approximately 1 % of the population over the age of 65, is the second most common neurodegenerative disorder after Alzheimer's disease. It was reported that pathogenic mutations in DJ-1 lead to autosomal recessive early-onset familial Parkinsonism. The L166P mutant of DJ-1 is the most commonly studied loss-of-function mutation in early onset familial PD, but the underlying mechanisms are still unknown. Edaravone is a powerful free radical scavenger used in clinical treatment for cerebral ischemic stroke. In the present study, we investigated the effects of edaravone on the neurotoxicity in PD-induced isoforms of DJ-1 containing the mutation L166P. Our results indicated that edaravone was able to significantly attenuate oxidative stress and improve mitochondrial function. Furthermore, edaravone was found to reduce apoptosis in Neuro2a cells through modulation of mitochondria-dependent apoptosis pathways. Interestingly, our result also demonstrated that edaravone was able to up-regulate VMAT2 expression in N2a cells in a dose-dependent manner. Our findings enhance the understanding of the neuro-protective effects of edaravone in cell models and suggest that edaravone offers significant protection in a PD-related in vitro model.

  18. An approximate solution of the two-group critical problem for reflected slabs

    International Nuclear Information System (INIS)

    Ishiguro, Y.; Garcia, R.D.M.

    1977-01-01

    A new approximation is developed to solve two group slab problems involving two media where one of the media is infinite. The method consists in combining the P sub(L) approximation with invariance principles. Several numerical results are reported for the critical slab problem [pt

  19. Characterization of substrate preference for Slc1p and Cst26p in Saccharomyces cerevisiae using lipidomic approaches and an LPAAT activity assay.

    Directory of Open Access Journals (Sweden)

    Guanghou Shui

    Full Text Available BACKGROUND: Phosphatidic acid (PA is a key regulated intermediate and precursor for de novo biosynthesis of all glycerophospholipids. PA can be synthesized through the acylation of lysophosphatidic acid (LPA by 1-acyl-3-phosphate acyltransferase (also called lysophosphatidic acid acyltransferase, LPAAT. Recent findings have substantiated the essential roles of acyltransferases in various biological functions. METHODOLOGIES/PRINCIPAL FINDINGS: We used a flow-injection-based lipidomic approach with approximately 200 multiple reaction monitoring (MRM transitions to pre-screen fatty acyl composition of phospholipids in the yeast Saccharomyces cerevisiae mutants. Dramatic changes were observed in fatty acyl composition in some yeast mutants including Slc1p, a well-characterized LPAAT, and Cst26p, a recently characterized phosphatidylinositol stearoyl incorporating 1 protein and putative LPAAT in S. cerevisiae. A comprehensive high-performance liquid chromatography-based multi-stage MRM approach (more than 500 MRM transitions was developed and further applied to quantify individual phospholipids in both strains to confirm these changes. Our data suggest potential fatty acyl substrates as well as fatty acyls that compensate for defects in both Cst26p and Slc1p mutants. These results were consistent with those from a non-radioactive LPAAT enzymatic assay using C17-LPA and acyl-CoA donors as substrates. CONCLUSIONS: We found that Slc1p utilized fatty acid (FA 18:1 and FA 14:0 as substrates to synthesize corresponding PAs; moreover, it was probably the only acyltransferase responsible for acylation of saturated short-chain fatty acyls (12:0 and 10:0 in S. cerevisiae. We also identified FA 18:0, FA 16:0, FA 14:0 and exogenous FA 17:0 as preferred substrates for Cst26p because transformation with a GFP-tagged CST26 restored the phospholipid profile of a CST26 mutant. Our current findings expand the enzymes and existing scope of acyl-CoA donors for

  20. SIRT1 mediates Sphk1/S1P-induced proliferation and migration of endothelial cells.

    Science.gov (United States)

    Gao, Zhan; Wang, Hua; Xiao, Feng-Jun; Shi, Xue-Feng; Zhang, Yi-Kun; Xu, Qin Qin; Zhang, Xiao-Yan; Ha, Xiao-Qin; Wang, Li-Sheng

    2016-05-01

    Angiogenesis is one of the most important components of embryonic organ formation and vessel growth after birth. Sphingosine kinase 1 (Sphk1) and S1P has been confirmed to participate in various cell signaling pathways and physiological processes including neovascularisation. However, the mechanisms that Sphk1/S1P regulates neovascularisation remain unclear. In this study, we elucidated that Sphk1/S1P upregulates sirtuin 1 (SIRT1), a NAD+ dependent deacetylases protease which exerts multiple cellular functions, to regulate the proliferation and migration of endothelial cells. By using CCK8 and Transwell assays, we demonstrated that Sphk1 and SIRT1 knockdown could significantly decrease proliferation and migration of HUVEC cells. Sphk1 inhibition results in SIRT1 downregulation which could be reversed by exogenous S1P in HUVEC cells. Treatment of HUVECs with S1P reverses the impaired proliferation and migration caused by SIRT1 knockdown. Furthermore, Sphk1 knockdown inhibits the phosphorylation of P38 MAPK, ERK and AKT. Treatment of HUVECs with PD98059, SB203580 and Wortmannin, which are the inhibitors of ERK, P38 MAPK and AKT respectively, resulted in decreased SIRT1 expression and reduced migration of HUVEC cells. Thus, we conclude that Sphk1/S1P induces SIRT1 upregulation through multiple pathways including P38 MAPK, ERK and AKT signals. This is the first report to disclose the existence and roles of Sphk1/S1P/SIRT1 axis in regulation of endothelial cell proliferation and migration, which may provide a theoretical basis for angiogenesis. Copyright © 2016. Published by Elsevier Ltd.

  1. Organometallic chemical vapor deposition and characterization of ZnGe(1-x)Si(x)P2-Ge alloys on GaP substrates

    Science.gov (United States)

    Xing, G. C.; Bachmann, Klaus J.; Posthill, J. B.; Timmons, M. L.

    1993-01-01

    The epitaxial growth of ZnGe(1-x)Si(x)P2-Ge alloys on GaP substrates by open tube organometallic chemical vapor deposition (OMCVD) is reported. The chemical composition of the alloys characterized by energy dispersive X-ray spectroscopy shows that alloys with x up to 0.13 can be deposited on (001) GaP. Epitaxial growth with mirror smooth surface morphology was achieved for x less than or equal to 0.05. Transmission electron microscopy (TEM) micrographs of these alloys show specular epitaxy and the absence of microstructural defects indicating a defect density of less than 10(exp 7) cm(sup -2). Selected area electron diffraction pattern of the alloy shows that the epitaxial layer crystallizes in the chalcopyrite structure with relatively weak superlattice reflections indicating certain degree of randomness in the cation sublattice. Hall measurements show that the alloys are p-type, like the unalloyed films; the carrier concentration, however, dropped about 10 times from 2 x 10(exp 18) to 2 x 10(exp 17) cm(sup -3). Absorption measurements indicate that the band tailing in the absorption spectra of the alloy was shifted about 0.04 eV towards shorter wavelength as compared to the unalloyed material. Diodes fabricated from the n(+)-GaP/p-ZnSiP2-ZnGeP2-Ge heterostructure at x = 0.05 have a reverse break-down voltage of -10.8 V and a reverse saturation current density of approximately 6 x 10(exp -8) A/sq cm.

  2. S1P and the birth of platelets

    Science.gov (United States)

    Galvani, Sylvain; Rafii, Shahin; Nachman, Ralph

    2012-01-01

    Recent work has highlighted the multitude of biological functions of sphingosine 1-phosphate (S1P), which include roles in hematopoietic cell trafficking, organization of immune organs, vascular development, and neuroinflammation. Indeed, a functional antagonist of S1P1 receptor, FTY720/Gilenya, has entered the clinic as a novel therapeutic for multiple sclerosis. In this issue of the JEM, Zhang et al. highlight yet another function of this lipid mediator: thrombopoiesis. The S1P1 receptor is required for the growth of proplatelet strings in the bloodstream and the shedding of platelets into the circulation. Notably, the sharp gradient of S1P between blood and the interstitial fluids seems to be essential to ensure the production of platelets, and S1P appears to cooperate with the CXCL12–CXCR4 axis. Pharmacologic modulation of the S1P1 receptor altered circulating platelet numbers acutely, suggesting a potential therapeutic strategy for controlling thrombocytopenic states. However, the S1P4 receptor may also regulate thrombopoiesis during stress-induced accelerated platelet production. This work reveals a novel physiological action of the S1P/S1P1 duet that could potentially be harnessed for clinical translation. PMID:23166370

  3. Deactivation kinetics of acid-sensing ion channel 1a are strongly pH-sensitive.

    Science.gov (United States)

    MacLean, David M; Jayaraman, Vasanthi

    2017-03-21

    Acid-sensing ion channels (ASICs) are trimeric cation-selective ion channels activated by protons in the physiological range. Recent reports have revealed that postsynaptically localized ASICs contribute to the excitatory postsynaptic current by responding to the transient acidification of the synaptic cleft that accompanies neurotransmission. In response to such brief acidic transients, both recombinant and native ASICs show extremely rapid deactivation in outside-out patches when jumping from a pH 5 stimulus to a single resting pH of 8. Given that the resting pH of the synaptic cleft is highly dynamic and depends on recent synaptic activity, we explored the kinetics of ASIC1a and 1a/2a heteromers to such brief pH transients over a wider [H + ] range to approximate neuronal conditions better. Surprisingly, the deactivation of ASICs was steeply dependent on the pH, spanning nearly three orders of magnitude from extremely fast (pH 8 to very slow (>300 ms) at pH 7. This study provides an example of a ligand-gated ion channel whose deactivation is sensitive to agonist concentrations that do not directly activate the receptor. Kinetic simulations and further mutagenesis provide evidence that ASICs show such steeply agonist-dependent deactivation because of strong cooperativity in proton binding. This capacity to signal across such a large synaptically relevant bandwidth enhances the response to small-amplitude acidifications likely to occur at the cleft and may provide ASICs with the ability to shape activity in response to the recent history of the synapse.

  4. Minimax rational approximation of the Fermi-Dirac distribution

    Science.gov (United States)

    Moussa, Jonathan E.

    2016-10-01

    Accurate rational approximations of the Fermi-Dirac distribution are a useful component in many numerical algorithms for electronic structure calculations. The best known approximations use O(log(βΔ)log(ɛ-1)) poles to achieve an error tolerance ɛ at temperature β-1 over an energy interval Δ. We apply minimax approximation to reduce the number of poles by a factor of four and replace Δ with Δocc, the occupied energy interval. This is particularly beneficial when Δ ≫ Δocc, such as in electronic structure calculations that use a large basis set.

  5. Strategies for P2P connectivity in reconfigurable converged wired/wireless access networks.

    Science.gov (United States)

    Puerto, Gustavo; Mora, José; Ortega, Beatriz; Capmany, José

    2010-12-06

    This paper presents different strategies to define the architecture of a Radio-Over-Fiber (RoF) Access networks enabling Peer-to-Peer (P2P) functionalities. The architectures fully exploit the flexibility of a wavelength router based on the feedback configuration of an Arrayed Waveguide Grating (AWG) and an optical switch to broadcast P2P services among diverse infrastructures featuring dynamic channel allocation and enabling an optical platform for 3G and beyond wireless backhaul requirements. The first architecture incorporates a tunable laser to generate a dedicated wavelength for P2P purposes and the second architecture takes advantage of reused wavelengths to enable the P2P connectivity among Optical Network Units (ONUs) or Base Stations (BS). While these two approaches allow the P2P connectivity in a one at a time basis (1:1), the third architecture enables the broadcasting of P2P sessions among different ONUs or BSs at the same time (1:M). Experimental assessment of the proposed architecture shows approximately 0.6% Error Vector Magnitude (EVM) degradation for wireless services and 1 dB penalty in average for 1 x 10(-12) Bit Error Rate (BER) for wired baseband services.

  6. RAC1 P29S regulates PD-L1 expression in melanoma

    Science.gov (United States)

    Vu, Ha Linh; Rosenbaum, Sheera; Purwin, Timothy J.; Davies, Michael A.; Aplin, Andrew E.

    2015-01-01

    Summary Whole exome sequencing of cutaneous melanoma has led to the detection of P29 mutations in RAC1 in 5–9% of samples, but the role of RAC1 P29 mutations in melanoma biology remains unclear. Using reverse phase protein array analysis to examine the changes in protein/phospho-protein expression, we identified cyclin B1, PD-L1, Ets-1, and Syk as being selectively upregulated with RAC1 P29S expression and downregulated with RAC1 P29S depletion. Using the melanoma patient samples in TCGA, we found PD-L1 expression to be significantly increased in RAC1 P29S patients compared to RAC1 WT as well as other RAC1 mutants. The finding that PD-L1 is upregulated suggests that oncogenic RAC1 P29S may promote suppression of the antitumor immune response. This is a new insight into the biological function of RAC1 P29S mutations with potential clinical implications as PD-L1 is a candidate biomarker for increased benefit from treatment with anti-PD1 or anti-PD-L1 antibodies. PMID:26176707

  7. Approximate symmetries of Hamiltonians

    Science.gov (United States)

    Chubb, Christopher T.; Flammia, Steven T.

    2017-08-01

    We explore the relationship between approximate symmetries of a gapped Hamiltonian and the structure of its ground space. We start by considering approximate symmetry operators, defined as unitary operators whose commutators with the Hamiltonian have norms that are sufficiently small. We show that when approximate symmetry operators can be restricted to the ground space while approximately preserving certain mutual commutation relations. We generalize the Stone-von Neumann theorem to matrices that approximately satisfy the canonical (Heisenberg-Weyl-type) commutation relations and use this to show that approximate symmetry operators can certify the degeneracy of the ground space even though they only approximately form a group. Importantly, the notions of "approximate" and "small" are all independent of the dimension of the ambient Hilbert space and depend only on the degeneracy in the ground space. Our analysis additionally holds for any gapped band of sufficiently small width in the excited spectrum of the Hamiltonian, and we discuss applications of these ideas to topological quantum phases of matter and topological quantum error correcting codes. Finally, in our analysis, we also provide an exponential improvement upon bounds concerning the existence of shared approximate eigenvectors of approximately commuting operators under an added normality constraint, which may be of independent interest.

  8. Sphingosine kinase-1, S1P transporter spinster homolog 2 and S1P2 mRNA expressions are increased in liver with advanced fibrosis in human.

    Science.gov (United States)

    Sato, Masaya; Ikeda, Hitoshi; Uranbileg, Baasanjav; Kurano, Makoto; Saigusa, Daisuke; Aoki, Junken; Maki, Harufumi; Kudo, Hiroki; Hasegawa, Kiyoshi; Kokudo, Norihiro; Yatomi, Yutaka

    2016-08-26

    The role of sphingosine 1-phosphate (S1P) in liver fibrosis or inflammation was not fully examined in human. Controversy exists which S1P receptors, S1P1 and S1P3 vs S1P2, would be importantly involved in its mechanism. To clarify these matters, 80 patients who received liver resection for hepatocellular carcinoma and 9 patients for metastatic liver tumor were enrolled. S1P metabolism was analyzed in background, non-tumorous liver tissue. mRNA levels of sphingosine kinase 1 (SK1) but not SK2 were increased in livers with fibrosis stages 3-4 compared to those with 0-2 and to normal liver. However, S1P was not increased in advanced fibrotic liver, where mRNA levels of S1P transporter spinster homolog 2 (SPNS2) but not S1P-degrading enzymes were enhanced. Furthermore, mRNA levels of S1P2 but not S1P1 or S1P3 were increased in advanced fibrotic liver. These increased mRNA levels of SK1, SPNS2 and S1P2 in fibrotic liver were correlated with α-smooth muscle actin mRNA levels in liver, and with serum ALT levels. In conclusion, S1P may be actively generated, transported to outside the cells, and bind to its specific receptor in human liver to play a role in fibrosis or inflammation. Altered S1P metabolism in fibrotic liver may be their therapeutic target.

  9. DISCOVERY OF MAIN-BELT COMET P/2006 VW{sub 139} BY Pan-STARRS1

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Henry H.; Yang Bin; Haghighipour, Nader; Kaluna, Heather M.; Denneau, Larry; Jedicke, Robert; Wainscoat, Richard J.; Armstrong, James D.; Micheli, Marco; Keane, Jacqueline V.; Urban, Laurie; Riesen, Timm; Meech, Karen J. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Fitzsimmons, Alan [Astrophysics Research Centre, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Novakovic, Bojan [Department of Astronomy, Faculty of Mathematics, University of Belgrade, Studentski trg 16, 11000 Belgrade (Serbia); Duddy, Samuel R.; Lowry, Stephen C. [Centre for Astrophysics and Planetary Science, The University of Kent, Canterbury CT2 7NH (United Kingdom); Trujillo, Chadwick A. [Gemini Observatory, Northern Operations Center, 670 N. Aohoku Place, Hilo, HI 96720 (United States); Abe, Shinsuke; Cheng, Yu-Chi, E-mail: hsieh@ifa.hawaii.edu [Institute of Astronomy, National Central University, 300 Jhongda Rd, Jhongli 32001, Taiwan (China); and others

    2012-03-20

    The main-belt asteroid (300163) 2006 VW{sub 139} (later designated P/2006 VW{sub 139}) was discovered to exhibit comet-like activity by the Pan-STARRS1 (PS1) survey telescope using automated point-spread-function analyses performed by PS1's Moving Object Processing System. Deep follow-up observations show both a short ({approx}10'') antisolar dust tail and a longer ({approx}60'') dust trail aligned with the object's orbit plane, similar to the morphology observed for another main-belt comet (MBC), P/2010 R2 (La Sagra), and other well-established comets, implying the action of a long-lived, sublimation-driven emission event. Photometry showing the brightness of the near-nucleus coma remaining constant over {approx}30 days provides further evidence for this object's cometary nature, suggesting it is in fact an MBC, and not a disrupted asteroid. A spectroscopic search for CN emission was unsuccessful, though we find an upper limit CN production rate of Q{sub CN} < 1.3 Multiplication-Sign 10{sup 24} mol s{sup -1}, from which we infer a water production rate of Q{sub H{sub 2O}}<10{sup 26} mol s{sup -1}. We also find an approximately linear optical spectral slope of 7.2%/1000 A, similar to other cometary dust comae. Numerical simulations indicate that P/2006 VW{sub 139} is dynamically stable for >100 Myr, while a search for a potential asteroid family around the object reveals a cluster of 24 asteroids within a cutoff distance of 68 m s{sup -1}. At 70 m s{sup -1}, this cluster merges with the Themis family, suggesting that it could be similar to the Beagle family to which another MBC, 133P/Elst-Pizarro, belongs.

  10. The Second Eigenvalue of the p-Laplacian as p Goes to 1

    Directory of Open Access Journals (Sweden)

    Enea Parini

    2010-01-01

    Full Text Available The asymptotic behaviour of the second eigenvalue of the p-Laplacian operator as p goes to 1 is investigated. The limit setting depends only on the geometry of the domain. In the particular case of a planar disc, it is possible to show that the second eigenfunctions are nonradial if p is close enough to 1.

  11. Search for stopped gluinos from p-anti-p collisions at s**(1/2) = 1.96 TeV

    Czech Academy of Sciences Publication Activity Database

    Abazov, V. M.; Abbott, B.; Abolins, M.; Kupčo, Alexander; Lokajíček, Miloš; Šimák, Vladislav

    2007-01-01

    Roč. 99, č. 13 (2007), 131801/1-131801/7 ISSN 0031-9007 R&D Projects: GA MŠk 1P04LA210; GA MŠk 1P05LA257 Institutional research plan: CEZ:AV0Z10100502 Keywords : supersymmetry * gluino * neutralino * D0 * DZero Subject RIV: BF - Elementary Particle s and High Energy Physics Impact factor: 6.944, year: 2007

  12. The sphingosine 1-phosphate receptor S1P(2) triggers hepatic wound healing

    NARCIS (Netherlands)

    Serriere-Lanneau, Valerie; Teixeira-Clerc, Fatima; Li, Liying; Schippers, Marlies; de Wries, Willie; Julien, Boris; Tran-Van-Nhieu, Jeanne; Manin, Sylvie; Poelstra, Klaas; Chun, Jerold; Carpentier, Stephane; Levade, Thierry; Mallat, Ariane; Lotersztajn, Sophie

    Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid produced by sphingosine kinase (SphK1 and 2). We previously showed that S1P receptors (S1P(1), S1P(2), and S1P(3)) are expressed in hepatic myofibroblasts (hMF), a population of cells that triggers matrix remodeling during liver injury. Here

  13. Fis1, DLP1, and Pex11p coordinately regulate peroxisome morphogenesis

    International Nuclear Information System (INIS)

    Kobayashi, Shinta; Tanaka, Atsushi; Fujiki, Yukio

    2007-01-01

    Dynamin-like protein 1 (DLP1) and Pex11pβ function in morphogenesis of peroxisomes. In the present work, we investigated whether Fis1 is involved in fission of peroxisomes. Endogenous Fis1 was morphologically detected in peroxisomes as well as mitochondria in wild-type CHO-K1 and DLP1-defective ZP121 cells. Subcellular fractionation studies also revealed the presence of Fis1 in peroxisomes. Peroxisomal Fis1 showed the same topology, i.e., C-tail anchored membrane protein, as the mitochondrial one. Furthermore, ectopic expression of FIS1 induced peroxisome proliferation in CHO-K1 cells, while the interference of FIS1 RNA resulted in tubulation of peroxisomes, hence reducing the number of peroxisomes. Fis1 interacted with Pex11pβ, by direct binding apparently involving the C-terminal region of Pex11pβ in the interaction. Pex11pβ also interacted with each other, whereas the binding of Pex11pβ to DLP1 was not detectable. Moreover, ternary complexes comprising Fis1, Pex11pβ, and DLP1 were detected by chemical cross-linking. We also showed that the highly conserved N-terminal domain of Pex11pβ was required for the homo-oligomerization of Pex11pβ and indispensable for the peroxisome-proliferating activity. Taken together, these findings indicate that Fis1 plays important roles in peroxisome division and maintenance of peroxisome morphology in mammalian cells, possibly in a concerted manner with Pex11pβ and DLP1

  14. Rigorous numerical approximation of Ruelle–Perron–Frobenius operators and topological pressure of expanding maps

    International Nuclear Information System (INIS)

    Terhesiu, Dalia; Froyland, Gary

    2008-01-01

    It is well known that for different classes of transformations, including the class of piecewise C 2 expanding maps T : [0, 1] O, Ulam's method is an efficient way to numerically approximate the absolutely continuous invariant measure of T. We develop a new extension of Ulam's method and prove that this extension can be used for the numerical approximation of the Ruelle–Perron–Frobenius operator associated with T and the potential φ β = −β log |T | |, where β element of R. In particular, we prove that our extended Ulam's method is a powerful tool for computing the topological pressure P(T, φ β ) and the density of the equilibrium state

  15. User's manual for THYDE-P1

    International Nuclear Information System (INIS)

    Asahi, Yoshiro

    1982-04-01

    THYDE-P1 is a computer code applicable to LWR (light water reactor) plant dynamics in response to various disturbances. This work is the user's mannual of THYDE-P1 (version SV02L03). The input requirements, steady state adjustment, execution of runs and output specifications are described. (author)

  16. Chk1 inhibition activates p53 through p38 MAPK in tetraploid cancer cells.

    Science.gov (United States)

    Vitale, Ilio; Senovilla, Laura; Galluzzi, Lorenzo; Criollo, Alfredo; Vivet, Sonia; Castedo, Maria; Kroemer, Guido

    2008-07-01

    We have previously shown that tetraploid cancer cells succumb through a p53-dependent apoptotic pathway when checkpoint kinase 1 (Chk1) is depleted by small interfering RNAs (siRNAs) or inhibited with 7-hydroxystaurosporine (UCN-01). Here, we demonstrate that Chk1 inhibition results in the activating phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK). Depletion of p38 MAPK by transfection with a siRNA targeting the alpha isoform of p38 MAPK (p38alpha MAPK) abolishes the phosphorylation of p53 on serines 15 and 46 that is induced by Chk1 knockdown. The siRNA-mediated downregulation and pharmacological inhibition of p38alpha MAPK (with SB 203580) also reduces cell death induced by Chk1 knockdown or UCN-01. These results underscore the role of p38 MAPK as a pro-apoptotic kinase in the p53-dependant pathway for the therapeutic elimination of polyploidy cells.

  17. Geometric approximation algorithms

    CERN Document Server

    Har-Peled, Sariel

    2011-01-01

    Exact algorithms for dealing with geometric objects are complicated, hard to implement in practice, and slow. Over the last 20 years a theory of geometric approximation algorithms has emerged. These algorithms tend to be simple, fast, and more robust than their exact counterparts. This book is the first to cover geometric approximation algorithms in detail. In addition, more traditional computational geometry techniques that are widely used in developing such algorithms, like sampling, linear programming, etc., are also surveyed. Other topics covered include approximate nearest-neighbor search, shape approximation, coresets, dimension reduction, and embeddings. The topics covered are relatively independent and are supplemented by exercises. Close to 200 color figures are included in the text to illustrate proofs and ideas.

  18. Identification and characterization of a novel P2Y 12 variant in a patient diagnosed with type 1 von Willebrand disease in the European MCMDM-1VWD study.

    Science.gov (United States)

    Daly, Martina E; Dawood, Ban B; Lester, William A; Peake, Ian R; Rodeghiero, Francesco; Goodeve, Anne C; Makris, Michael; Wilde, Jonathan T; Mumford, Andrew D; Watson, Stephen P; Mundell, Stuart J

    2009-04-23

    We investigated whether defects in the P2Y(12) ADP receptor gene (P2RY12) contribute to the bleeding tendency in 92 index cases enrolled in the European MCMDM-1VWD study. A heterozygous mutation, predicting a lysine to glutamate (K174E) substitution in P2Y(12), was identified in one case with mild type 1 von Willebrand disease (VWD) and a VWF defect. Platelets from the index case and relatives carrying the K174E defect changed shape in response to ADP, but showed reduced and reversible aggregation in response to 10 muM ADP, unlike the maximal, sustained aggregation observed in controls. The reduced response was associated with an approximate 50% reduction in binding of [(3)H]2MeS-ADP to P2Y(12), whereas binding to the P2Y(1) receptor was normal. A hemagglutinin-tagged K174E P2Y(12) variant showed surface expression in CHO cells, markedly reduced binding to [(3)H]2MeS-ADP, and minimal ADP-mediated inhibition of forskolin-induced adenylyl cyclase activity. Our results provide further evidence for locus heterogeneity in type 1 VWD.

  19. Late-stage optimization of a tercyclic class of S1P3-sparing, S1P1 receptor agonists.

    Science.gov (United States)

    Horan, Joshua C; Kuzmich, Daniel; Liu, Pingrong; DiSalvo, Darren; Lord, John; Mao, Can; Hopkins, Tamara D; Yu, Hui; Harcken, Christian; Betageri, Raj; Hill-Drzewi, Melissa; Patenaude, Lori; Patel, Monica; Fletcher, Kimberly; Terenzzio, Donna; Linehan, Brian; Xia, Heather; Patel, Mita; Studwell, Debbie; Miller, Craig; Hickey, Eugene; Levin, Jeremy I; Smith, Dustin; Kemper, Raymond A; Modis, Louise K; Bannen, Lynne C; Chan, Diva S; Mac, Morrison B; Ng, Stephanie; Wang, Yong; Xu, Wei; Lemieux, René M

    2016-01-15

    Poor solubility and cationic amphiphilic drug-likeness were liabilities identified for a lead series of S1P3-sparing, S1P1 agonists originally developed from a high-throughput screening campaign. This work describes the subsequent optimization of these leads by balancing potency, selectivity, solubility and overall molecular charge. Focused SAR studies revealed favorable structural modifications that, when combined, produced compounds with overall balanced profiles. The low brain exposure observed in rat suggests that these compounds would be best suited for the potential treatment of peripheral autoimmune disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Computer simulation of the effect of temperature on pH.

    Science.gov (United States)

    Kipp, J E; Schuck, D F

    1995-11-01

    The effect of temperature on solution pH was simulated by computer (program PHTEMP). We have determined that the change in pH due to shifts in acid-base equilibria [delta pH = pH(60 degrees C) - pH(25 degrees C)] can be substantial for compounds such as aliphatic amines that have high enthalpies for acid dissociation. This is of particular significance during elevated temperature experiments in which changes in the pKa values of formulation components, and hence the solution pH, can accelerate decomposition as compared to those formulations where sensitive functionality is absent. PHTEMP afforded the following results at initial pH = 7 (25 degrees C): (a) 0.1 M triethylamine (delta H zero = 10.4 kcal/mol) delta pH approximately -0.8; (b) 0.1 M acetic acid (delta H zero = -0.1 kcal/mol) delta pH approximately 0; (c) 0.1 M sulfuric acid (delta H zero 1 = -12 kcal/mol; delta H zero 2 = -5.4 kcal/mol) delta pH approximately -0.4. Solutions of general pharmaceutical interest were also studied and included a 12-component amino acid mixture, 0.1 M glycine, and 0.1 M triethylamine in either 0.02 M citric acid or 0.05 M TRIS buffer. In each case the pH change with temperature was dependent on the concentrations of components, the enthalpies for each acid dissociation, and the starting pH. At lower pH ( 9). These results are interpreted as the effect of a relative change in hydronium ion activity, delta H+/H+(initial), due to temperature-induced shifts in equilibria (acid dissociation, water autoprotolysis). This relative change must become larger as H+ decreases (pH increases). The output of PHTEMP was experimentally verified with 0.1 M glycine and with a multiple component amino acid solution. In both cases, agreement with prediction was excellent. The results of this investigation underscore the need to critically review formulation choices for both thermodynamic and traditional kinetic effects on the resulting product stability.

  1. Semiclassical approximation in Batalin-Vilkovisky formalism

    International Nuclear Information System (INIS)

    Schwarz, A.

    1993-01-01

    The geometry of supermanifolds provided with a Q-structure (i.e. with an odd vector field Q satisfying {Q, Q}=0), a P-structure (odd symplectic structure) and an S-structure (volume element) or with various combinations of these structures is studied. The results are applied to the analysis of the Batalin-Vilkovisky approach to the quantization of gauge theories. In particular the semiclassical approximation in this approach is expressed in terms of Reidemeister torsion. (orig.)

  2. Microscopic model accounting of 2p2p configurations in magic nuclei

    International Nuclear Information System (INIS)

    Kamerdzhiev, S.P.

    1983-01-01

    A model for account of the 2p2h configurations in magic nuclei is described in the framework of the Green function formalism. The model is formulated in the lowest order in the phonon production amplitude, so that the series are expansions not over pure 2p2h configurations, but over con figurations of the type ''1p1h+phonon''. Equations are obtained for the vertex and the density matrix, as well as an expression for the transition probabilities, that are extensions of the corresponding results of the theory of finite Fermi systems, or of the random-phase approximation to the case where the ''1p1h+phonon'' configurations are taken into account. Corrections to the one-particle phenomenological basis which arise with account for complicated configurations are obtained. Comparison with other approaches, using phonons, has shown that they are particular cases of the described model

  3. Diagonal Pade approximations for initial value problems

    International Nuclear Information System (INIS)

    Reusch, M.F.; Ratzan, L.; Pomphrey, N.; Park, W.

    1987-06-01

    Diagonal Pade approximations to the time evolution operator for initial value problems are applied in a novel way to the numerical solution of these problems by explicitly factoring the polynomials of the approximation. A remarkable gain over conventional methods in efficiency and accuracy of solution is obtained. 20 refs., 3 figs., 1 tab

  4. Approximate Q.C.D. lower bound for the bag constant B

    International Nuclear Information System (INIS)

    Nielsen, H.B.

    1978-01-01

    Using an article by Savvidy from 1977 in which a state in Q.C.D. with lower energy than the perturbative vacuum was found, the author calculates an approximate lower bound for the M.I.T. bag constant B relative to the Q.C.D. coupling parameter Λ. With an M.I.T. bag constant Bsup(1/4)=145 MeV the author finds Λsub(P)<=0.89 GeV when the propagator of the gluon is used to renormalize the coupling constant. (Auth.)

  5. Studies of the decays $B^+ \\to p \\bar p h^+$ and observation of $B^+ \\to \\kern 0.1em\\bar{\\kern -0.1em\\Lambda}(1520)p$

    CERN Document Server

    Aaij, R; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Baesso, C; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Burducea, I; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Craik, D C; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Dogaru, M; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gorbounov, P; Gordon, H; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicheur, A; Hicks, E; Hill, D; Hoballah, M; Hombach, C; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Kenyon, I R; Ketel, T; Keune, A; Khanji, B; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Maratas, J; Marconi, U; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Martynov, A; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurice, E; Mazurov, A; McCarthy, J; McNab, A; McNulty, R; McSkelly, B; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mordà, A; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neubert, S; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pescatore, L; Pesen, E; Petridis, K; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Roberts, D A; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rouvinet, J; Ruf, T; Ruffini, F; Ruiz, H; Ruiz Valls, P; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Sirendi, M; Skidmore, N; Skwarnicki, T; Smith, N A; Smith, E; Smith, J; Smith, M; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Sun, L; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urner, D; Ustyuzhanin, A; Uwer, U; Vagnoni, V; Valenti, G; Vallier, A; Van Dijk, M; Vazquez Gomez, R; Vazquez Regueiro, P; Vázquez Sierra, C; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, C; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiechczynski, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wimberley, J; Wishahi, J; Witek, M; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A

    2013-01-01

    Dynamics and direct $CP$ violation in three-body charmless decays of charged $B$ mesons to a proton, an antiproton and a light meson (pion or kaon) are studied using data, corresponding to an integrated luminosity of 1.0$ {\\,fb}^{-1}$, collected by the ${LHCb}$ experiment in $pp$ collisions at a center-of-mass energy of 7 TeV. Production spectra are determined as a function of Dalitz-plot and helicity variables. The forward-backward asymmetry of the light meson in the $p\\bar p$ rest frame is measured. No significant $CP$ asymmetry in $B^+ \\to p \\bar p K^+$ decay is found in any region of the Dalitz plane. We present the first observation of the decay $B^+ \\to \\kern 0.1em\\bar{\\kern -0.1em\\Lambda}(1520)(\\to K^+\\bar p)p$ near the $K^+\\bar p$ threshold and measure $\\mathcal{B}(B^+ \\to \\kern 0.1em\\bar{\\kern -0.1em\\Lambda}(1520)p)=(3.9^{+1.0}_{-0.9} (\\mathrm{stat})\\pm0.1 (\\mathrm{syst})\\pm0.3 (\\mathrm{BF}))\\times 10^{-7}$, where BF denotes the uncertainty on secondary branching fractions.

  6. Sparse approximation with bases

    CERN Document Server

    2015-01-01

    This book systematically presents recent fundamental results on greedy approximation with respect to bases. Motivated by numerous applications, the last decade has seen great successes in studying nonlinear sparse approximation. Recent findings have established that greedy-type algorithms are suitable methods of nonlinear approximation in both sparse approximation with respect to bases and sparse approximation with respect to redundant systems. These insights, combined with some previous fundamental results, form the basis for constructing the theory of greedy approximation. Taking into account the theoretical and practical demand for this kind of theory, the book systematically elaborates a theoretical framework for greedy approximation and its applications.  The book addresses the needs of researchers working in numerical mathematics, harmonic analysis, and functional analysis. It quickly takes the reader from classical results to the latest frontier, but is written at the level of a graduate course and do...

  7. Jet Fragmentation in p+p, p+Pb and Pb+Pb at ATLAS

    CERN Document Server

    Slovak, Radim; The ATLAS collaboration

    2017-01-01

    Jets are an important tool to study the hot, dense matter produced in Pb+Pb collisions at the LHC. Due to the loss of some of the jet’s energy outside the jet cone, jet rates have been found to be reduced by approximately a factor of two, in the most central events and over a wide kinematic range. In order to understand precisely how the jets are modified, it is important to measure how the jet momentum is carried by its fragmentation products. The longitudinal momentum fraction of charged particles in jets from Pb+Pb, p+Pb, and p+p collisions have been measured using the ATLAS detector. Proton-proton and p+Pb collisions provide necessary baseline measurements for quantifying the modifications in Pb+Pb collisions. In Run 1, ATLAS collected samples of p+p and Pb+Pb collisions at a center of mass energy of 2.76 TeV and a sample of p+Pb collisions at 5.02 TeV. In Run 2, large samples of p+p and Pb+Pb collisions at 5.02 TeV have been collected providing a complete set of collision systems at 5.02 TeV. In this t...

  8. A lifetime measurement of the 1s2p 3P1 level in helium-like Mg and Al

    International Nuclear Information System (INIS)

    Armour, I.A.; Silver, J.D.; Traebert, E.; Oxford Univ.

    1981-01-01

    The lifetimes of the 1s2p 3 P 1 levels of helium-like magnesium and aluminium have been measured by the beam-foil decay curve technique. The 1s 2 -1s2p transitions were observed with a curved-crystal x-ray spectrometer. Decay curves taken under systematically varied conditions have been evaluated using several techniques including a cascade model. The results are in agreement with most of the theoretical predictions. (author)

  9. The effect of the bioactive sphingolipids S1P and C1P on multipotent stromal cells--new opportunities in regenerative medicine.

    Science.gov (United States)

    Marycz, Krzysztof; Śmieszek, Agnieszka; Jeleń, Marta; Chrząstek, Klaudia; Grzesiak, Jakub; Meissner, Justyna

    2015-09-01

    Sphingosine-1-phosphate (S1P) and ceramide-1-phosphate (C1P) belong to a family of bioactive sphingolipids that act as important extracellular signaling molecules and chemoattractants. This study investigated the influence of S1P and C1P on the morphology, proliferation activity and osteogenic properties of rat multipotent stromal cells derived from bone marrow (BMSCs) and subcutaneous adipose tissue (ASCs). We show that S1P and C1P can influence mesenchymal stem cells (MSCs), each in a different manner. S1P stimulation promoted the formation of cellular aggregates of BMSCs and ASCs, while C1P had an effect on the regular growth pattern and expanded intercellular connections, thereby increasing the proliferative activity. Although osteogenic differentiation of MSCs was enhanced by the addition of S1P, the effectiveness of osteoblast differentiation was more evident in BMSCs, particularly when biochemical and molecular marker levels were considered. The results of the functional osteogenic differentiation assay, which includes an evaluation of the efficiency of extracellular matrix mineralization (SEM-EDX), revealed the formation of numerous mineral aggregates in BMSC cultures stimulated with S1P. Our data demonstrated that in an appropriate combination, the bioactive sphingolipids S1P and C1P may find wide application in regenerative medicine, particularly in bone regeneration with the use of MSCs.

  10. Berberine reduces fibronectin expression by suppressing the S1P-S1P2 receptor pathway in experimental diabetic nephropathy models.

    Directory of Open Access Journals (Sweden)

    Kaipeng Huang

    Full Text Available The accumulation of glomerular extracellular matrix (ECM is one of the critical pathological characteristics of diabetic renal fibrosis. Fibronectin (FN is an important constituent of ECM. Our previous studies indicate that the activation of the sphingosine kinase 1 (SphK1-sphingosine 1- phosphate (S1P signaling pathway plays a key regulatory role in FN production in glomerular mesangial cells (GMCs under diabetic condition. Among the five S1P receptors, the activation of S1P2 receptor is the most abundant. Berberine (BBR treatment also effectively inhibits SphK1 activity and S1P production in the kidneys of diabetic models, thus improving renal injury. Based on these data, we further explored whether BBR could prevent FN production in GMCs under diabetic condition via the S1P2 receptor. Here, we showed that BBR significantly down-regulated the expression of S1P2 receptor in diabetic rat kidneys and GMCs exposed to high glucose (HG and simultaneously inhibited S1P2 receptor-mediated FN overproduction. Further, BBR also obviously suppressed the activation of NF-κB induced by HG, which was accompanied by reduced S1P2 receptor and FN expression. Taken together, our findings suggest that BBR reduces FN expression by acting on the S1P2 receptor in the mesangium under diabetic condition. The role of BBR in S1P2 receptor expression regulation could closely associate with its inhibitory effect on NF-κB activation.

  11. A Prokaryotic S1P Lyase Degrades Extracellular S1P In Vitro and In Vivo: Implication for Treating Hyperproliferative Disorders

    Science.gov (United States)

    Huwiler, Andrea; Bourquin, Florence; Kotelevets, Nataliya; Pastukhov, Oleksandr; Capitani, Guido; Grütter, Markus G.; Zangemeister-Wittke, Uwe

    2011-01-01

    Sphingosine-1-phosphate (S1P) regulates a broad spectrum of fundamental cellular processes like proliferation, death, migration and cytokine production. Therefore, elevated levels of S1P may be causal to various pathologic conditions including cancer, fibrosis, inflammation, autoimmune diseases and aberrant angiogenesis. Here we report that S1P lyase from the prokaryote Symbiobacterium thermophilum (StSPL) degrades extracellular S1P in vitro and in blood. Moreover, we investigated its effect on cellular responses typical of fibrosis, cancer and aberrant angiogenesis using renal mesangial cells, endothelial cells, breast (MCF-7) and colon (HCT 116) carcinoma cells as disease models. In all cell types, wild-type StSPL, but not an inactive mutant, disrupted MAPK phosphorylation stimulated by exogenous S1P. Functionally, disruption of S1P receptor signaling by S1P depletion inhibited proliferation and expression of connective tissue growth factor in mesangial cells, proliferation, migration and VEGF expression in carcinoma cells, and proliferation and migration of endothelial cells. Upon intravenous injection of StSPL in mice, plasma S1P levels rapidly declined by 70% within 1 h and then recovered to normal 6 h after injection. Using the chicken chorioallantoic membrane model we further demonstrate that also under in vivo conditions StSPL, but not the inactive mutant, inhibited tumor cell-induced angiogenesis as an S1P-dependent process. Our data demonstrate that recombinant StSPL is active under extracellular conditions and holds promise as a new enzyme therapeutic for diseases associated with increased levels of S1P and S1P receptor signaling. PMID:21829623

  12. Saccharomyces cerevisiae GTPase complex: Gtr1p-Gtr2p regulates cell-proliferation through Saccharomyces cerevisiae Ran-binding protein, Yrb2p

    International Nuclear Information System (INIS)

    Wang Yonggang; Nakashima, Nobutaka; Sekiguchi, Takeshi; Nishimoto, Takeharu

    2005-01-01

    A Gtr1p GTPase, the GDP mutant of which suppresses both temperature-sensitive mutants of Saccharomyces cerevisiae RanGEF/Prp20p and RanGAP/Rna1p, was presently found to interact with Yrb2p, the S. cerevisiae homologue of mammalian Ran-binding protein 3. Gtr1p bound the Ran-binding domain of Yrb2p. In contrast, Gtr2p, a partner of Gtr1p, did not bind Yrb2p, although it bound Gtr1p. A triple mutant: yrb2Δ gtr1Δ gtr2Δ was lethal, while a double mutant: gtr1Δ gtr2Δ survived well, indicating that Yrb2p protected cells from the killing effect of gtr1Δ gtr2Δ. Recombinant Gtr1p and Gtr2p were purified as a complex from Escherichia coli. The resulting Gtr1p-Gtr2p complex was comprised of an equal amount of Gtr1p and Gtr2p, which inhibited the Rna1p/Yrb2 dependent RanGAP activity. Thus, the Gtr1p-Gtr2p cycle was suggested to regulate the Ran cycle through Yrb2p

  13. Validity of the equivalent-photon approximation for the production of massive spin-1 particles

    International Nuclear Information System (INIS)

    Jayaraman, T.

    1986-01-01

    It is pointed out that the equivalent-photon approximation (EPA) for processes with massive spin-1 particles in the final state would have validity in a more restricted kinematic domain than for processes where it is commonly applied, viz., those with spin-1/2 or spin-0 particles in the final state. The criterion for the validity of EPA for the two-photon production of a pair of charged, massive, point-like spin-1 particles V ± , each of mass M and with a standard magnetic moment (k=1) is obtained. In a process in which one of the photons is real and the other virtual with four-momentum q, the condition for the validity of EPA is absolute value of q 2 2 , in addition to the usual condition absolute value of q 2 2 , W being the V + V - invariant mass. In a process in which both photons are virtual (with four-momenta q and q'), the condition is absolute value of q 2 absolute value of q' 2 W 4 8 , in addition to absolute value of q 2 2 , absolute value of q' 2 2 and absolute value of q 2 2 , absolute value of q' 2 2 . Even when these extra conditions permitting the use of EPA are not fulfilled, convenient approximate expressions may still be obtained assuming merely absolute value of q 2 2 and absolute value of q' 2 2 . It is also discussed how the extra conditions are altered when the vector bosons are incorporated in a spontaneously broken gauge theory. Examples of W boson production in Weinberg-Salam model are considered for which the condition absolute value of q 2 absolute value of q' 2 W 4 8 is shown to be removed. (author)

  14. On the Approximation of Generalized Lipschitz Function by Euler Means of Conjugate Series of Fourier Series

    Science.gov (United States)

    Kushwaha, Jitendra Kumar

    2013-01-01

    Approximation theory is a very important field which has various applications in pure and applied mathematics. The present study deals with a new theorem on the approximation of functions of Lipschitz class by using Euler's mean of conjugate series of Fourier series. In this paper, the degree of approximation by using Euler's means of conjugate of functions belonging to Lip (ξ(t), p) class has been obtained. Lipα and Lip (α, p) classes are the particular cases of Lip (ξ(t), p) class. The main result of this paper generalizes some well-known results in this direction. PMID:24379744

  15. The transient M/G/1/0 queue: some bounds and approximations for light traffic with application to reliability

    Directory of Open Access Journals (Sweden)

    J. Ben Atkinson

    1995-01-01

    Full Text Available We consider the transient analysis of the M/G/1/0 queue, for which Pn(t denotes the probability that there are no customers in the system at time t, given that there are n(n=0,1 customers in the system at time 0. The analysis, which is based upon coupling theory, leads to simple bounds on Pn(t for the M/G/1/0 and M/PH/1/0 queues and improved bounds for the special case M/Er/1/0. Numerical results are presented for various values of the mean arrival rate λ to demonstrate the increasing accuracy of approximations based upon the above bounds in light traffic, i.e., as λ→0. An important area of application for the M/G/1/0 queue is as a reliability model for a single repairable component. Since most practical reliability problems have λ values that are small relative to the mean service rate, the approximations are potentially useful in that context. A duality relation between the M/G/1/0 and GI/M/1/0 queues is also described.

  16. Astrophysical s-factor measurements for {sup 1}20Te(p,{gamma}){sup 1}21I and {sup 1}20Te(p,n){sup 1}20I reactions; {sup 1}20Te(p,{gamma}){sup 1}21I ve {sup 1}20Te(p,n){sup 1}20I reaksiyonlarinin astrofiziksel s-factor oelcuemleri

    Energy Technology Data Exchange (ETDEWEB)

    Gueray, R T; Oezkan, N; Yalcin, C [Kocaeli University, Kocaeli (Turkey); Goerres, J; DeBoer, R; Palumbo, A; Tan, W P; Wiescher, M [University of Notre Dame, (United States); Fueloep, Zs; Somorjai, E [Institute of Nuclear Research ATOMKI (Hungary); Lee, H Y [Argonne National Laboratory (United States)

    2009-07-01

    Astrophysical S-factors for the {sup 1}20Te(p,{gamma}){sup 1}21I and {sup 1}20Te(p,n){sup 1}20I reactions have been measured in the effective center-of-mass energies between 2.47 MeV and 7.93 MeV. Experimental data have been compared with the Hauser-Fesbach statistical model calculations obtained with the model codes NON-SMOKER and TALYS. The discrepancies between the experimental results and calculations can mainly be attributed to the optical model potentials used in the codes.

  17. Sparse and smooth canonical correlation analysis through rank-1 matrix approximation

    Science.gov (United States)

    Aïssa-El-Bey, Abdeldjalil; Seghouane, Abd-Krim

    2017-12-01

    Canonical correlation analysis (CCA) is a well-known technique used to characterize the relationship between two sets of multidimensional variables by finding linear combinations of variables with maximal correlation. Sparse CCA and smooth or regularized CCA are two widely used variants of CCA because of the improved interpretability of the former and the better performance of the later. So far, the cross-matrix product of the two sets of multidimensional variables has been widely used for the derivation of these variants. In this paper, two new algorithms for sparse CCA and smooth CCA are proposed. These algorithms differ from the existing ones in their derivation which is based on penalized rank-1 matrix approximation and the orthogonal projectors onto the space spanned by the two sets of multidimensional variables instead of the simple cross-matrix product. The performance and effectiveness of the proposed algorithms are tested on simulated experiments. On these results, it can be observed that they outperform the state of the art sparse CCA algorithms.

  18. Nano- to microscale dynamics of P-selectin detachment from leukocyte interfaces. II. Tether flow terminated by P-selectin dissociation from PSGL-1.

    Science.gov (United States)

    Heinrich, Volkmar; Leung, Andrew; Evans, Evan

    2005-03-01

    We have used a biomembrane force probe decorated with P-selectin to form point attachments with PSGL-1 receptors on a human neutrophil (PMN) in a calcium-containing medium and then to quantify the forces experienced by the attachment during retraction of the PMN at fixed speed. From first touch to final detachment, the typical force history exhibited the following sequence of events: i), an initial linear-elastic displacement of the PMN surface, ii), an abrupt crossover to viscoplastic flow that signaled membrane separation from the interior cytoskeleton and the beginning of a membrane tether, and iii), the final detachment from the probe tip most often by one precipitous step of P-selectin:PSGL-1 dissociation. Analyzing the initial elastic response and membrane unbinding from the cytoskeleton in our companion article I, we focus in this article on the regime of tether extrusion that nearly always occurred before release of the extracellular adhesion bond at pulling speeds > or =1 microm/s. The force during tether growth appeared to approach a plateau at long times. Examined over a large range of pulling speeds up to 150 microm/s, the plateau force exhibited a significant shear thinning as indicated by a weak power-law dependence on pulling speed, f(infinity) = 60 pN(nu(pull)/microm/s)(0.25). Using this shear-thinning response to describe the viscous element in a nonlinear Maxwell-like fluid model, we show that a weak serial-elastic component with a stiffness of approximately 0.07 pN/nm provides good agreement with the time course of the tether force approach to the plateau under constant pulling speed.

  19. Diffusion Coefficient Calculations With Low Order Legendre Polynomial and Chebyshev Polynomial Approximation for the Transport Equation in Spherical Geometry

    International Nuclear Information System (INIS)

    Yasa, F.; Anli, F.; Guengoer, S.

    2007-01-01

    We present analytical calculations of spherically symmetric radioactive transfer and neutron transport using a hypothesis of P1 and T1 low order polynomial approximation for diffusion coefficient D. Transport equation in spherical geometry is considered as the pseudo slab equation. The validity of polynomial expansionion in transport theory is investigated through a comparison with classic diffusion theory. It is found that for causes when the fluctuation of the scattering cross section dominates, the quantitative difference between the polynomial approximation and diffusion results was physically acceptable in general

  20. Measurement of the Z/γ* (→ e+e-) + ≥ n Jet Production Cross Sections in p$\\bar{p}$ Collisions at √s = 1.96 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Buehler, Marc [Univ. of Illinois, Chicago, IL (United States)

    2005-01-01

    A study of events with Z/γ* bosons and hadronic jets produced at the Tevatron in p$\\bar{p}$ collisions at a center of mass energy of 1.96 TeV is presented. The data consist of approximately 14,000 Z/γ* → e+e- decay candidates from 343 pb-1 of integrated luminosity collected with the D0 detector. Cross sections and jet production properties have been measured for Z/γ* + ≥ 0 to 5 jet events. This measurement represents a significant improvement over previous measurements at the Tevatron, and it is the first at this center of mass energy with the D0 detector. The results are in good agreement with QCD predictions.

  1. Hydrogen atom excitation in intense attosecond laser field: Gauge dependence of dipole approximation

    Energy Technology Data Exchange (ETDEWEB)

    Aldarmaa, Ch., E-mail: aldaraa2004@yahoo.com, E-mail: l-xemee@yahoo.com; Khenmedekh, L., E-mail: aldaraa2004@yahoo.com, E-mail: l-xemee@yahoo.com [Theoretical Physics and Simulation Group, School of Materials Technology, MUST (Mongolia); Lkhagva, O. [School of Physics and Electronics, NUM (Mongolia)

    2014-03-24

    It is assumed that, the atomic excitations probability can be calculated using first order perturbation theory and dipole approximations. The validity of the dipole approximations had been examined by comparing the results with the results obtained by exact calculations within the first order perturbation theory[2]. Figure 1 shows the time dependence of the transition probability in the dipole approximation. From these plots it is obvious that, the probabilities obtained in the length gauge are higher than that in the velocity gauge, in the interaction period (−τ/2approximation) calculations results. (Figure 2) Though the time evolution of the same transition probabilities are different for these cases, the final results are the same for all three cases, excluding the 6s-6p{sub 0} transition. For the later case, only the length gauge give a false results, but the velocity gauge give the same result as the exact one, for the final value of the transition probability.

  2. Approximating distributions from moments

    Science.gov (United States)

    Pawula, R. F.

    1987-11-01

    A method based upon Pearson-type approximations from statistics is developed for approximating a symmetric probability density function from its moments. The extended Fokker-Planck equation for non-Markov processes is shown to be the underlying foundation for the approximations. The approximation is shown to be exact for the beta probability density function. The applicability of the general method is illustrated by numerous pithy examples from linear and nonlinear filtering of both Markov and non-Markov dichotomous noise. New approximations are given for the probability density function in two cases in which exact solutions are unavailable, those of (i) the filter-limiter-filter problem and (ii) second-order Butterworth filtering of the random telegraph signal. The approximate results are compared with previously published Monte Carlo simulations in these two cases.

  3. Is Biological Subtype Prognostic of Locoregional Recurrence Risk in Women With pT1-2N0 Breast Cancer Treated With Mastectomy?

    International Nuclear Information System (INIS)

    Truong, Pauline T.; Sadek, Betro T.; Lesperance, Maria F.; Alexander, Cheryl S.; Shenouda, Mina; Raad, Rita Abi; Taghian, Alphonse G.

    2014-01-01

    Purpose: To examine locoregional and distant recurrence (LRR and DR) in women with pT1-2N0 breast cancer according to approximated subtype and clinicopathologic characteristics. Methods and Materials: Two independent datasets were pooled and analyzed. The study participants were 1994 patients with pT1-2N0M0 breast cancer, treated with mastectomy without radiation therapy. The patients were classified into 1 of 5 subtypes: luminal A (ER+ or PR+/HER 2−/grade 1-2, n=1202); luminal B (ER+ or PR+/HER 2−/grade 3, n=294); luminal HER 2 (ER+ or PR+/HER 2+, n=221); HER 2 (ER−/PR−/HER 2+, n=105) and triple-negative breast cancer (TNBC) (ER−/PR−/HER 2−, n=172). Results: The median follow-up time was 4.3 years. The 5-year Kaplan-Meier (KM) LRR were 1.8% in luminal A, 3.1% in luminal B, 1.7% in luminal HER 2, 1.9% in HER 2, and 1.9% in TNBC cohorts (P=.81). The 5-year KM DR was highest among women with TNBC: 1.8% in luminal A, 5.0% in luminal B, 2.4% in luminal HER 2, 1.1% in HER 2, and 9.6% in TNBC cohorts (P 2 cm, lobular histology, and close/positive surgical margins. Conclusions: The 5-year risk of LRR in our pT1-2N0 cohort treated with mastectomy was generally low, with no significant differences observed between approximated subtypes. Among the subtypes, TNBC conferred the highest risk of DR and an elevated risk of LRR in the presence of positive or close margins. Our data suggest that although subtype alone cannot be used as the sole criterion to offer postmastectomy radiation therapy, it may reasonably be considered in conjunction with other clinicopathologic factors including tumor size, histology, and margin status. Larger cohorts and longer follow-up times are needed to define which women with node-negative disease have high postmastectomy LRR risks in contemporary practice

  4. Plasma Physics Approximations in Ares

    International Nuclear Information System (INIS)

    Managan, R. A.

    2015-01-01

    Lee & More derived analytic forms for the transport properties of a plasma. Many hydro-codes use their formulae for electrical and thermal conductivity. The coefficients are complex functions of Fermi-Dirac integrals, Fn( μ/θ ), the chemical potential, μ or ζ = ln(1+e μ/θ ), and the temperature, θ = kT. Since these formulae are expensive to compute, rational function approximations were fit to them. Approximations are also used to find the chemical potential, either μ or ζ . The fits use ζ as the independent variable instead of μ/θ . New fits are provided for A α (ζ ),A β (ζ ), ζ, f(ζ ) = (1 + e -μ/θ )F 1/2 (μ/θ), F 1/2 '/F 1/2 , F c α , and F c β . In each case the relative error of the fit is minimized since the functions can vary by many orders of magnitude. The new fits are designed to exactly preserve the limiting values in the non-degenerate and highly degenerate limits or as ζ→ 0 or ∞. The original fits due to Lee & More and George Zimmerman are presented for comparison.

  5. Kernel-Based Approximate Dynamic Programming Using Bellman Residual Elimination

    Science.gov (United States)

    2010-02-01

    Redding, Mike Robbins, Frant Sobolic, Justin Teo, Tuna Toksoz, Glenn Tournier, Aditya Undurti, Mario Valenti, Andy Whitten, Albert Wu, and Rodrigo...vector algorithms. Neural Computation, 12(5):1207–1245, 2000. [143] P. Schweitzer and A. Seidman. Generalized polynomial approximation in Markovian

  6. Tables of Shore and Fano parameters for the helium resonances 2s/sup 2/ /sup 1/S, 2p/sup 2/ /sup 1/D, and 2s 2p /sup 1/P excited in p-He collisions E/sub p/ = 33 to 150 keV

    Energy Technology Data Exchange (ETDEWEB)

    Bordenave-Montesquieu, A.; Benoit-Cattin, P.; Gleizes, A.; Merchez, H.

    1976-02-01

    Absolute values of Shore and Fano parameters are tabulated for the helium atom 2s/sup 2/ /sup 1/S, 2p/sup 2/ /sup 1/D, and 2s 2p /sup 1/P resonances produced by a proton beam. Observations were made on the spectra of ejected electrons. The important variation of the shape of the resonances with ejection angle is illustrated for E/sub p/ = 100 keV; the variation with proton energy is shown at 30/sup 0/.

  7. General Rytov approximation.

    Science.gov (United States)

    Potvin, Guy

    2015-10-01

    We examine how the Rytov approximation describing log-amplitude and phase fluctuations of a wave propagating through weak uniform turbulence can be generalized to the case of turbulence with a large-scale nonuniform component. We show how the large-scale refractive index field creates Fermat rays using the path integral formulation for paraxial propagation. We then show how the second-order derivatives of the Fermat ray action affect the Rytov approximation, and we discuss how a numerical algorithm would model the general Rytov approximation.

  8. Solution of the kinetic equation in the P3-approximation in a plane geometry

    International Nuclear Information System (INIS)

    Vlasov, Yu.A.

    1975-01-01

    A method and a program are described for solving single-velocity kinetic equations of neutron transfer for the plane geometry in the finite-difference approximation. A difference high-accuracy scheme and a matrix factorization method are used for the differential-difference equation systems. The program is written in the ALGOL-60 language and is adapted for M-20, M-220, M-222 and BESM-4 computers

  9. Deficiency of cyclin-dependent kinase inhibitors p21Cip1 and p27Kip1 accelerates atherogenesis in apolipoprotein E-deficient mice

    International Nuclear Information System (INIS)

    Akyuerek, Levent M.; Boehm, Manfred; Olive, Michelle; Zhou, Alex-Xianghua; San, Hong; Nabel, Elizabeth G.

    2010-01-01

    Cyclin-dependent kinase inhibitors, p21 Cip1 and p27 Kip1 , are upregulated during vascular cell proliferation and negatively regulate growth of vascular cells. We hypothesized that absence of either p21 Cip1 or p27 Kip1 in apolipoprotein E (apoE)-deficiency may increase atherosclerotic plaque formation. Compared to apoE -/- aortae, both apoE -/- /p21 -/- and apoE -/- /p27 -/- aortae exhibited significantly more atherosclerotic plaque following a high-cholesterol regimen. This increase was particularly observed in the abdominal aortic regions. Deficiency of p27 Kip1 accelerated plaque formation significantly more than p21 -/- in apoE -/- mice. This increased plaque formation was in parallel with increased intima/media area ratios. Deficiency of p21 Cip1 and p27 Kip1 accelerates atherogenesis in apoE -/- mice. These findings have significant implications for our understanding of the molecular basis of atherosclerosis associated with excessive proliferation of vascular cells.

  10. On the approximation by single hidden layer feedforward neural networks with fixed weights

    OpenAIRE

    Guliyev, Namig J.; Ismailov, Vugar E.

    2017-01-01

    International audience; Feedforward neural networks have wide applicability in various disciplines of science due to their universal approximation property. Some authors have shown that single hidden layer feedforward neural networks (SLFNs) with fixed weights still possess the universal approximation property provided that approximated functions are univariate. But this phenomenon does not lay any restrictions on the number of neurons in the hidden layer. The more this number, the more the p...

  11. Transcriptional regulation of the p73 gene, a member of the p53 family, by early growth response-1 (Egr-1)

    International Nuclear Information System (INIS)

    Lee, Sang-Wang; Kim, Eun-Joo; Um, Soo-Jong

    2007-01-01

    To elucidate the regulatory mechanism of p73 gene expression, we analyzed the human p73 promoter and found three putative Egr-1-binding sites located upstream of exon 1 (-1728, -321, and -38). The Egr-1 responsiveness of these sites was analyzed by transient transfection assays using 5'- and 3'-serial truncations of the p73 promoter, subcloned in a CAT reporter vector. The functional significance of the region was further confirmed by an electrophoretic mobility shift assay using the Egr-1 protein synthesized in vitro and a [ 32 P]-labeled middle site sequence, followed by competition with unlabeled wild-type or mutant oligonucleotides and supershift assays using an anti-Egr-1 antibody. When induced by either the nitric oxide donor NOC-18 or the PPARγ agonist troglitazone, Egr-1 bound to the p73 promoter, as assessed by chromatin immunoprecipitation assays, accompanied by increased expression of p73. MTT assays revealed that cell growth was significantly inhibited on treating the cells with troglitazone. Overall, our results provide direct evidence that Egr-1 positively regulated p73 expression by binding to its promoter in vivo, consistent with Egr-1 and p73 being involved in p53-independent tumor suppression

  12. Study of Stark Effect in n-doped 1.55 μm InN0.92yP1-1.92yBiy/InP MQWs

    Science.gov (United States)

    Bilel, C.; Chakir, K.; Rebey, A.; Alrowaili, Z. A.

    2018-05-01

    The effect of an applied electric field on electronic band structure and optical absorption properties of n-doped InN0.92y P1-1.92y Bi y /InP multiple quantum wells (MQWs) was theoretically studied using a self-consistent calculation combined with the 16-band anti-crossing model. The incorporation of N and Bi atoms into an InP host matrix leads to rapid reduction of the band gap energy covering a large infrared range. The optimization of the well parameters, such as the well/barrier widths, N/Bi compositions and doping density, allowed us to obtain InN0.92y P1-1.92y Bi y /InP MQWs operating at the wavelength 1.55 μm. Application of the electric field causes a red-shift of the fundamental transition energy T 1 accompanied by a significant change in the spatial distribution of confined electron density. The Stark effect on the absorption coefficient of n-doped InN0.92y P1-1.92y Bi y /InP MQWs was investigated. The Bi composition of these MQWs was adjusted for each electric field value in order to maintain the wavelength emission at 1.55 μm.

  13. Hal2p functions in Bdf1p-involved salt stress response in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Lei Chen

    Full Text Available The Saccharomyces cerevisiae Bdf1p associates with the basal transcription complexes TFIID and acts as a transcriptional regulator. Lack of Bdf1p is salt sensitive and displays abnormal mitochondrial function. The nucleotidase Hal2p detoxifies the toxic compound 3' -phosphoadenosine-5'-phosphate (pAp, which blocks the biosynthesis of methionine. Hal2p is also a target of high concentration of Na(+. Here, we reported that HAL2 overexpression recovered the salt stress sensitivity of bdf1Δ. Further evidence demonstrated that HAL2 expression was regulated indirectly by Bdf1p. The salt stress response mechanisms mediated by Bdf1p and Hal2p were different. Unlike hal2Δ, high Na(+ or Li(+ stress did not cause pAp accumulation in bdf1Δ and methionine supplementation did not recover its salt sensitivity. HAL2 overexpression in bdf1Δ reduced ROS level and improved mitochondrial function, but not respiration. Further analyses suggested that autophagy was apparently defective in bdf1Δ, and autophagy stimulated by Hal2p may play an important role in recovering mitochondrial functions and Na(+ sensitivity of bdf1Δ. Our findings shed new light towards our understanding about the molecular mechanism of Bdf1p-involved salt stress response in budding yeast.

  14. Measurement and interpretation of momentum spectra of the inclusive reaction np→pX between 1.4 and 1.9GeV/c. Determination of cross sections for the np→pΔ330 channel

    International Nuclear Information System (INIS)

    Laville, J.-L.

    1976-01-01

    The creation of a high intensity beam of monokinetic neutrons obtained from stripping deuterons extracted from the synchrotron Saturne (C.E.N., Saclay) has allowed to measure with good statistical accuracy 43 momentum spectra of the final proton of the inclusive reaction np→pX at 1.39, 1.56, 1.73 and 1.90GeV/c (approximately 10 spectra per incident momentum). The final proton was analyzed with a magnetic spectrometer in the angular region between 0 and 20 deg in the laboratory. The set of results has been the object of two analyses: at first, the experimental spectra were compared with a pion exchange model modified by the off-shell parametrization of BENECKE-DURR-PILKUHN overall, this model correctly reproduces the measured spectra, both in form and absolute normalization. In the second analysis, the total and differential cross sections of the np→pΔ 33 0 channel were determined from the spectra measured using a subtraction procedure. The differential cross sections obtained in this way show an angular dependence that differs from the predictions of the pion exchange model. It is concluded that, at low energy, near its threshold, the reaction NN→NΔ 33 involves a set of more complex mechanisms than pion exchange alone, even if the latter remains dominant [fr

  15. Electron impact excitation-autoionisation of the (2s2)1S, (2p2)1D and (2s2p)1P autoionising states of helium

    International Nuclear Information System (INIS)

    Samardzic, O.; Hurn, J.A.; Weigold, E.; Brunger, M.J.

    1994-01-01

    The electron impact excitation of the (2s 2 ) 1 S, (2p 2 ) 1 D and (2s2p) 1 P autoionising states of helium and their subsequent radiationless decay was studied by observation of the ejected electrons. The present work was carried out at an incident energy of 94.6 eV and for ejected electron scattering angles in the range 25-135 deg C. The lineshapes observed in the present ejected electron spectra are analysed using the Shore-Balashov parametrisation. As part of the analysis procedure, numerically rigorous confidence limits were determined for the derived parameters. No previous experimental or theoretical work has been undertaken at the incident energy of the present investigation but, where possible, the resulting parameters are qualitatively compared against the 80 eV results of other experiments and theory. 37 refs., 4 figs

  16. TN approximation to reflected slab and computation of the critical half thicknesses

    International Nuclear Information System (INIS)

    Anli, F.; Guengoer, S.; Yasa, F.; Oztuerk, H.

    2006-01-01

    The criticality solution to one-speed neutron transport equation using the T N approximation is described for reflected slab. In the solution, Marshak type boundary condition is used. The critical half thicknesses are computed for different values of c and reflection coefficients. Computations are made by using the both T N and P N approximation for the comparison

  17. Is Biological Subtype Prognostic of Locoregional Recurrence Risk in Women With pT1-2N0 Breast Cancer Treated With Mastectomy?

    Energy Technology Data Exchange (ETDEWEB)

    Truong, Pauline T., E-mail: ptruong@bccancer.bc.ca [Radiation Therapy Program, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, Victoria, BC (Canada); Breast Cancer Outcomes Unit, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, Victoria, BC (Canada); Sadek, Betro T. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Lesperance, Maria F. [Radiation Therapy Program, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, Victoria, BC (Canada); Alexander, Cheryl S. [Breast Cancer Outcomes Unit, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, Victoria, BC (Canada); Shenouda, Mina; Raad, Rita Abi; Taghian, Alphonse G. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States)

    2014-01-01

    Purpose: To examine locoregional and distant recurrence (LRR and DR) in women with pT1-2N0 breast cancer according to approximated subtype and clinicopathologic characteristics. Methods and Materials: Two independent datasets were pooled and analyzed. The study participants were 1994 patients with pT1-2N0M0 breast cancer, treated with mastectomy without radiation therapy. The patients were classified into 1 of 5 subtypes: luminal A (ER+ or PR+/HER 2−/grade 1-2, n=1202); luminal B (ER+ or PR+/HER 2−/grade 3, n=294); luminal HER 2 (ER+ or PR+/HER 2+, n=221); HER 2 (ER−/PR−/HER 2+, n=105) and triple-negative breast cancer (TNBC) (ER−/PR−/HER 2−, n=172). Results: The median follow-up time was 4.3 years. The 5-year Kaplan-Meier (KM) LRR were 1.8% in luminal A, 3.1% in luminal B, 1.7% in luminal HER 2, 1.9% in HER 2, and 1.9% in TNBC cohorts (P=.81). The 5-year KM DR was highest among women with TNBC: 1.8% in luminal A, 5.0% in luminal B, 2.4% in luminal HER 2, 1.1% in HER 2, and 9.6% in TNBC cohorts (P<.001). Among 172 women with TNBC, the 5-year KM LRR were 1.3% with clear margins versus 12.5% with close or positive margins (P=.04). On multivariable analysis, factors that conferred higher LRR risk were tumors >2 cm, lobular histology, and close/positive surgical margins. Conclusions: The 5-year risk of LRR in our pT1-2N0 cohort treated with mastectomy was generally low, with no significant differences observed between approximated subtypes. Among the subtypes, TNBC conferred the highest risk of DR and an elevated risk of LRR in the presence of positive or close margins. Our data suggest that although subtype alone cannot be used as the sole criterion to offer postmastectomy radiation therapy, it may reasonably be considered in conjunction with other clinicopathologic factors including tumor size, histology, and margin status. Larger cohorts and longer follow-up times are needed to define which women with node-negative disease have high postmastectomy LRR

  18. An extension of Brosowski-Meinardus theorem on invariant approximation

    International Nuclear Information System (INIS)

    Liaqat Ali Khan; Abdul Rahim Khan.

    1991-07-01

    We obtain a generalization of a fixed point theorem of Dotson for non-expansive mappings on star-shaped sets and then use it to prove a unified Brosowski-Meinardus theorem on invariant approximation in the setting of p-normed linear spaces. (author). 13 refs

  19. Optimal Control via Reinforcement Learning with Symbolic Policy Approximation

    NARCIS (Netherlands)

    Kubalìk, Jiřì; Alibekov, Eduard; Babuska, R.; Dochain, Denis; Henrion, Didier; Peaucelle, Dimitri

    2017-01-01

    <p>Model-based reinforcement learning (RL) algorithms can be used to derive optimal control laws for nonlinear dynamic systems. With continuous-valued state and input variables, RL algorithms have to rely on function approximators to represent the value function and policy mappings. This paper

  20. Shake-up transitions in S 2p, S 2s and F 1s photoionization of the SF6 molecule

    International Nuclear Information System (INIS)

    Decleva, P; Fronzoni, G; Kivimaeki, A; Alvarez Ruiz, J; Svensson, S

    2009-01-01

    Shake-up transitions occurring upon core photoionization in the SF 6 molecule have been studied experimentally and theoretically. The S 2p, S 2s and F 1s shake-up satellite photoelectron spectra were measured using Al Ka radiation at 1487 eV photon energy. They have been interpreted with the aid of ab initio configuration interaction calculations in the sudden-limit approximation. For the S 2p spectrum, conjugate shake-up transitions were also calculated. Clear evidence of conjugate processes is observed in the S 2p shake-up spectrum measured at 230 eV photon energy. The experimental and theoretical S 2p and S 2s shake-up spectra show very similar structures mainly due to orbital relaxation involving S 3s and 3p participation. For the calculation of the F 1s shake-up spectrum, the symmetry lowering of the molecule in the final states was considered, resulting in a good agreement with the experiment.

  1. On the Distribution of Zeros and Poles of Rational Approximants on Intervals

    Directory of Open Access Journals (Sweden)

    V. V. Andrievskii

    2012-01-01

    Full Text Available The distribution of zeros and poles of best rational approximants is well understood for the functions (=||, >0. If ∈[−1,1] is not holomorphic on [−1,1], the distribution of the zeros of best rational approximants is governed by the equilibrium measure of [−1,1] under the additional assumption that the rational approximants are restricted to a bounded degree of the denominator. This phenomenon was discovered first for polynomial approximation. In this paper, we investigate the asymptotic distribution of zeros, respectively, -values, and poles of best real rational approximants of degree at most to a function ∈[−1,1] that is real-valued, but not holomorphic on [−1,1]. Generalizations to the lower half of the Walsh table are indicated.

  2. A role of the sphingosine-1-phosphate (S1P)-S1P receptor 2 pathway in epithelial defense against cancer (EDAC).

    Science.gov (United States)

    Yamamoto, Sayaka; Yako, Yuta; Fujioka, Yoichiro; Kajita, Mihoko; Kameyama, Takeshi; Kon, Shunsuke; Ishikawa, Susumu; Ohba, Yusuke; Ohno, Yusuke; Kihara, Akio; Fujita, Yasuyuki

    2016-02-01

    At the initial step of carcinogenesis, transformation occurs in single cells within epithelia, where the newly emerging transformed cells are surrounded by normal epithelial cells. A recent study revealed that normal epithelial cells have an ability to sense and actively eliminate the neighboring transformed cells, a process named epithelial defense against cancer (EDAC). However, the molecular mechanism of this tumor-suppressive activity is largely unknown. In this study, we investigated a role for the sphingosine-1-phosphate (S1P)-S1P receptor 2 (S1PR2) pathway in EDAC. First, we show that addition of the S1PR2 inhibitor significantly suppresses apical extrusion of RasV12-transformed cells that are surrounded by normal cells. In addition, knockdown of S1PR2 in normal cells induces the same effect, indicating that S1PR2 in the surrounding normal cells plays a positive role in the apical elimination of the transformed cells. Of importance, not endogenous S1P but exogenous S1P is involved in this process. By using FRET analyses, we demonstrate that S1PR2 mediates Rho activation in normal cells neighboring RasV12-transformed cells, thereby promoting accumulation of filamin, a crucial regulator of EDAC. Collectively these data indicate that S1P is a key extrinsic factor that affects the outcome of cell competition between normal and transformed epithelial cells. © 2016 Yamamoto, Yako, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  3. Approximate Bayesian recursive estimation

    Czech Academy of Sciences Publication Activity Database

    Kárný, Miroslav

    2014-01-01

    Roč. 285, č. 1 (2014), s. 100-111 ISSN 0020-0255 R&D Projects: GA ČR GA13-13502S Institutional support: RVO:67985556 Keywords : Approximate parameter estimation * Bayesian recursive estimation * Kullback–Leibler divergence * Forgetting Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 4.038, year: 2014 http://library.utia.cas.cz/separaty/2014/AS/karny-0425539.pdf

  4. Polymeric gel nanoparticle pH sensors for intracellular measurements

    DEFF Research Database (Denmark)

    Almdal, Kristoffer; Andresen, Thomas Lars; Benjaminsen, Rikke Vicki

    pH range is approximately 4 pH units and thus a nanoparticle sensor with two pH sensitive fluorophores is appropriate. With one pH sensitive fluorophore the output from the sensor follows R=R0+R1/10(pKa-pH), where R is the ratio of fluorescence for the two fluorophores, R0 is the minimum value of R...

  5. On a novel iterative method to compute polynomial approximations to Bessel functions of the first kind and its connection to the solution of fractional diffusion/diffusion-wave problems

    International Nuclear Information System (INIS)

    Yuste, Santos Bravo; Abad, Enrique

    2011-01-01

    We present an iterative method to obtain approximations to Bessel functions of the first kind J p (x) (p > -1) via the repeated application of an integral operator to an initial seed function f 0 (x). The class of seed functions f 0 (x) leading to sets of increasingly accurate approximations f n (x) is considerably large and includes any polynomial. When the operator is applied once to a polynomial of degree s, it yields a polynomial of degree s + 2, and so the iteration of this operator generates sets of increasingly better polynomial approximations of increasing degree. We focus on the set of polynomial approximations generated from the seed function f 0 (x) = 1. This set of polynomials is useful not only for the computation of J p (x) but also from a physical point of view, as it describes the long-time decay modes of certain fractional diffusion and diffusion-wave problems.

  6. 2,3,7,8-Tetrachlorodibenzo-p-dioxin modulates estradiol-induced aldehydic DNA lesions in human breast cancer cells through alteration of CYP1A1 and CYP1B1 expression.

    Science.gov (United States)

    Chen, Shou-Tung; Chen, Dar-Ren; Fang, Ju-Pin; Lin, Po-Hsiung

    2015-05-01

    Many genes responsible for the bioactivation of endogenous estrogen to reactive quinonoid metabolites, including cytochrome P450 (CYP) 1A1, 1A2, and 1B1, are well-known target genes of the aryl hydrocarbon receptor agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The purpose of this research was to investigate the roles of TCDD-mediated altered gene expression in the induction of aldehydic DNA lesions (ADLs) by 17β-estradiol (E2) in human MDA-MB-231 and MCF-7 breast cancer cells. We demonstrated that increases in the number of oxidant-mediated ADLs, including abasic sites and aldehydic base/sugar lesions, were detected in MDA-MB-231 cells exposed to E2. The DNA-damaging effects of E2 in MDA-MB-231 cells were prevented by pretreatment of cells with TCDD. In contrast, we did not observe statistically significant increases in the number of ADLs in MCF-7 cells exposed to E2. However, with TCDD pretreatment, an approximately twofold increase in the number of ADLs was detected in MCF-7 cells exposed to E2. TCDD pretreatment induces disparity in the disposition of E2 to reactive quinonoid metabolites and the subsequent formation of oxidative DNA lesions through alteration of CYP1A1 and CYP1B1 expression in human breast cancer cells.

  7. P2X1 receptors and the endothelium

    Directory of Open Access Journals (Sweden)

    LS Harrington

    2005-03-01

    Full Text Available Adenosine triphosphate (ATP is now established as a principle vaso-active mediator in the vasculature. Its actions on arteries are complex, and are mediated by the P2X and P2Y receptor families. It is generally accepted that ATP induces a bi-phasic response in arteries, inducing contraction via the P2X and P2Y receptors on the smooth muscle cells, and vasodilation via the actions of P2Y receptors located on the endothelium. However, a number of recent studies have placed P2X1 receptors on the endothelium of some arteries. The use of a specific P2X1 receptor ligand, a, b methylene ATP has demonstrated that P2X1 receptors also have a bi-functional role. The actions of ATP on P2X1 receptors is therefore dependant on its location, inducing contraction when located on the smooth muscle cells, and dilation when expressed on the endothelium, comparable to that of P2Y receptors.

  8. Wavelengths of the Ni-like 4d1S0 - 4p1P1 x-ray laser line

    International Nuclear Information System (INIS)

    Li, Y.; Nilsen, J.; Dunn, J.; Osterheld, A.L.; Ryabtsev, A.; Churilov, S.

    1998-01-01

    We measure the wavelengths of the Ni-like 3d 9 4d 1 S 0 - 3d 9 4p 1 P 1 x-ray laser line in several low-Z Ni-like ions ranging from Y (Z=39) to Cd (Z=48). These wavelengths are compared with optimized level calculations using a multiconfiguration Dirac-Fock code. With the help of these results, we identify this line to very high accuracy in nonlasing plasmas from As (Z=33) to Mo (Z=42). Accurate values of these wavelengths are essential for performing plasma imaging and interferometry experiments with multilayer optics that use the x-ray laser to backlight other plasmas. These results also provide important atomic data that are currently missing about the energy of the 4d 1 S 0 level in the NiI sequence. copyright 1998 The American Physical Society

  9. Systematic study of low-mass electron pair production in p-Be and p-Au collisions at 450 GeV/c

    NARCIS (Netherlands)

    Agakichiev, G; Appenheimer, M; Averbeck, R; Ballester, F; Baur, R; Brenschede, A; Diaz, J; Drees, A; Faschingbauer, U; Ferrero, JL; Fraenkel, Z; Franke, M; Fuchs, C; Gatti, E; Glassel, P; Gunzel, T; de los Heros, CP; Hess, F; Holzmann, R; Iourevitch, [No Value; Irmscher, D; Jacob, C; Kuhn, W; Lenkeit, B; Löhner, H.; Marin, A; Marques, FM; Martinez, G; Metag, [No Value; Notheisen, M; Novotny, R; Olsen, LH; Ostendorf, R; Panebrattsev, Y; Pfeiffer, A; Ravinovich, [No Value; Rehak, P; Sampietro, M; Schon, A; Schukraft, J; Schutz, Y; Shimansky, S; Shor, A; Simon, RS; Specht, HJ; Steiner, [No Value; Tapprogge, S; Tel-Zur, G; Tserruya, [No Value; Ullrich, T; Wilschut, H.; Wurm, JP

    In a joint effort the CERES/NA45 and TAPS collaborations have measured low-mass electron pairs in p-Be and p-Au collisions at 450 GeV/c at the CERN SPS. In the range covered up to approximate to 1.5 GeV/c(2) the mass spectra from p-Be and p-Au collisions are well explained by electron pairs from

  10. Nitric oxide prodrug JS-K inhibits ubiquitin E1 and kills tumor cells retaining wild-type p53.

    Science.gov (United States)

    Kitagaki, J; Yang, Y; Saavedra, J E; Colburn, N H; Keefer, L K; Perantoni, A O

    2009-01-29

    Nitric oxide (NO) is a major effector molecule in cancer prevention. A number of studies have shown that NO prodrug JS-K (O(2)-(2,4-dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate) induces apoptotic cell death in vitro and in vivo, indicating that it is a promising new therapeutic for cancer. However, the mechanism of its tumor-killing activity remains unclear. Ubiquitin plays an important role in the regulation of tumorigenesis and cell apoptosis. Our earlier report has shown that inactivation of the ubiquitin system through blocking E1 (ubiquitin-activating enzyme) activity preferentially induces apoptosis in p53-expressing transformed cells. As E1 has an active cysteine residue that could potentially interact with NO, we hypothesized that JS-K could inactivate E1 activity. E1 activity was evaluated by detecting ubiquitin-E1 conjugates through immunoblotting. JS-K strikingly inhibits the ubiquitin-E1 thioester formation in cells in a dose-dependent manner with an IC(50) of approximately 2 microM, whereas a JS-K analog that cannot release NO did not affect these levels in cells. Moreover, JS-K decreases total ubiquitylated proteins and increases p53 levels, which is mainly regulated by ubiquitin and proteasomal degradation. Furthermore, JS-K preferentially induces cell apoptosis in p53-expressing transformed cells. These findings indicate that JS-K inhibits E1 activity and kills transformed cells harboring wild-type p53.

  11. Glutathione-stabilized Cu nanoclusters as fluorescent probes for sensing pH and vitamin B1.

    Science.gov (United States)

    Luo, Yawen; Miao, Hong; Yang, Xiaoming

    2015-11-01

    Glutathione (GSH), playing roles as both a reducing reagent and protecting ligand, has been successfully employed for synthesizing Cu nanoclusters (CuNCs@GSH) on the basis of a simple and facile approach. The as-prepared CuNCs exhibited a fluorescence emission at 600nm with a quantum yield (QY) of approximately 3.6%. Subsequently, the CuNCs described here was employed as a broad-range pH sensor by virtue of the fluorescence intensity of CuNCs responding sensitively to pH fluctuating in a linear range of 4.0-12.0. Meanwhile, these prepared CuNCs were applied for detections of vitamin B1 (VB1) on the basis of positively charged VB1 neutralizing the negative surface charge of CuNCs, thus leading to the instability and aggregations of CuNCs, and further facilitating to quench their fluorescence. In addition, the proposed analytical method permitted detecting VB1 with a linear range of 2.0×10(-8)-1.0×10(-4) mol L(-1) as well as a detection limit of 4.6×10(-9) mol L(-1). Eventually, the practicability of this sensing approach was validated by assaying VB1 in human urine samples and pharmaceutical tablets, confirming its potential to broaden avenues for assaying VB1. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Structure of Sn1−xGex random alloys as obtained from the coherent potential approximation

    KAUST Repository

    Pulikkotil, J. J.

    2011-08-09

    The structure of the Sn1−xGex random alloys is studied using density functional theory and the coherent potential approximation. We report on the deviation of the Sn1−xGex alloys from Vegard’s law, addressing their full compositional range. The findings are compared to the related Si1−xGex alloys and to experimental results. Interestingly, the deviation from Vegard’s law is quantitatively and qualitatively different between the Sn1−xGex and Si1−xGex alloys. An almost linear dependence of the bulk modulus as a function of composition is found for Si1−xGex, whereas for Sn1−xGex the dependence is strongly nonlinear.

  13. Sphingosine 1-phosphate (S1P) signaling in glioblastoma multiforme-A systematic review.

    Science.gov (United States)

    Mahajan-Thakur, Shailaja; Bien-Möller, Sandra; Marx, Sascha; Schroeder, Henry; Rauch, Bernhard H

    2017-11-17

    The multifunctional sphingosine-1-phosphate (S1P) is a lipid signaling molecule and central regulator in the development of several cancer types. In recent years, intriguing information has become available regarding the role of S1P in the progression of Glioblastoma multiforme (GBM), the most aggressive and common brain tumor in adults. S1P modulates numerous cellular processes in GBM, such as oncogenesis, proliferation and survival, invasion, migration, metastasis and stem cell behavior. These processes are regulated via a family of five G-protein-coupled S1P receptors (S1PR1-5) and may involve mainly unknown intracellular targets. Distinct expression patterns and multiple intracellular signaling pathways of each S1PR subtype enable S1P to exert its pleiotropic cellular actions. Several studies have demonstrated alterations in S1P levels, the involvement of S1PRs and S1P metabolizing enzymes in GBM pathophysiology. While the tumorigenic actions of S1P involve the activation of several kinases and transcription factors, the specific G-protein (Gi, Gq, and G12/13)-coupled signaling pathways and downstream mediated effects in GBM remain to be elucidated in detail. This review summarizes the recent findings concerning the role of S1P and its receptors in GBM. We further highlight the current insights into the signaling pathways considered fundamental for regulating the cellular processes in GMB and ultimately patient prognosis.

  14. Approximation techniques for engineers

    CERN Document Server

    Komzsik, Louis

    2006-01-01

    Presenting numerous examples, algorithms, and industrial applications, Approximation Techniques for Engineers is your complete guide to the major techniques used in modern engineering practice. Whether you need approximations for discrete data of continuous functions, or you''re looking for approximate solutions to engineering problems, everything you need is nestled between the covers of this book. Now you can benefit from Louis Komzsik''s years of industrial experience to gain a working knowledge of a vast array of approximation techniques through this complete and self-contained resource.

  15. International Conference Approximation Theory XV

    CERN Document Server

    Schumaker, Larry

    2017-01-01

    These proceedings are based on papers presented at the international conference Approximation Theory XV, which was held May 22–25, 2016 in San Antonio, Texas. The conference was the fifteenth in a series of meetings in Approximation Theory held at various locations in the United States, and was attended by 146 participants. The book contains longer survey papers by some of the invited speakers covering topics such as compressive sensing, isogeometric analysis, and scaling limits of polynomials and entire functions of exponential type. The book also includes papers on a variety of current topics in Approximation Theory drawn from areas such as advances in kernel approximation with applications, approximation theory and algebraic geometry, multivariate splines for applications, practical function approximation, approximation of PDEs, wavelets and framelets with applications, approximation theory in signal processing, compressive sensing, rational interpolation, spline approximation in isogeometric analysis, a...

  16. High Resolution of the ECG Signal by Polynomial Approximation

    Directory of Open Access Journals (Sweden)

    G. Rozinaj

    2006-04-01

    Full Text Available Averaging techniques as temporal averaging and space averaging have been successfully used in many applications for attenuating interference [6], [7], [8], [9], [10]. In this paper we introduce interference removing of the ECG signal by polynomial approximation, with smoothing discrete dependencies, to make up for averaging methods. The method is suitable for low-level signals of the electrical activity of the heart often less than 10 m V. Most low-level signals arising from PR, ST and TP segments which can be detected eventually and their physiologic meaning can be appreciated. Of special importance for the diagnostic of the electrical activity of the heart is the activity bundle of His between P and R waveforms. We have established an artificial sine wave to ECG signal between P and R wave. The aim focus is to verify the smoothing method by polynomial approximation if the SNR (signal-to-noise ratio is negative (i.e. a signal is lower than noise.

  17. Transport of radionuclides in stochastic media. Pt. 1: The quasi-asymptotic approximation

    International Nuclear Information System (INIS)

    Devooght, J.; Smidts, O.F.

    1996-01-01

    A three-dimensional quasi-asymptotic approximate equation is developed for the transport of radionuclides in a stochastic velocity field. This approximation is derived from an integro-differential equation of transport in stochastic media, commonly encountered in hydrogeology. The quasi-asymptotic equation turns out to be a generalised Telegrapher's equation as found by Williams in the particular context of fractured media. We obtain the Telegrapher's equation without specifying the causes responsible for the random velocity field. Our model may thus be applied in porous media as well as in fractured media. We give the developments leading to the analytical solution of the three-dimensional Telegrapher's equation for constant parameters. This solution is then visualised for a source in the form of a square wave. (Author)

  18. p27{sup Kip1} inhibits tissue factor expression

    Energy Technology Data Exchange (ETDEWEB)

    Breitenstein, Alexander, E-mail: alexander.breitenstein@usz.ch [Cardiology, University Heart Center, University Hospital Zurich (Switzerland); Cardiovascular Research, Physiology Institute, University of Zurich (Switzerland); Center for Integrative Human Physiology (ZHIP), University of Zurich (Switzerland); Akhmedov, Alexander; Camici, Giovanni G.; Lüscher, Thomas F.; Tanner, Felix C. [Cardiology, University Heart Center, University Hospital Zurich (Switzerland); Cardiovascular Research, Physiology Institute, University of Zurich (Switzerland); Center for Integrative Human Physiology (ZHIP), University of Zurich (Switzerland)

    2013-10-04

    Highlights: •p27{sup Kip1}regulates the expression of tissue factor at the transcriptional level. •This inhibitory effect of p27{sup Kip1} is independently of its cell regulatory action. •The current study provides new insights into a pleiotrophic function of p27{sup Kip1}. -- Abstract: Background: The cyclin-dependent kinase inhibitor (CDKI) p27{sup Kip1} regulates cell proliferation and thus inhibits atherosclerosis and vascular remodeling. Expression of tissue factor (TF), the key initator of the coagulation cascade, is associated with atherosclerosis. Yet, it has not been studied whether p27{sup Kip1} influences the expression of TF. Methods and results: p27{sup Kip1} overexpression in human aortic endothelial cells was achieved by adenoviral transfection. Cells were rendered quiescent for 24 h in 0.5% fetal-calf serum. After stimulation with TNF-α (5 ng/ml), TF protein expression and activity was significantly reduced (n = 4; P < 0.001) in cells transfected with p27{sup Kip1}. In line with this, p27{sup Kip1} overexpression reduced cytokine-induced TF mRNA expression (n = 4; P < 0.01) and TF promotor activity (n = 4; P < 0.05). In contrast, activation of the MAP kinases p38, ERK and JNK was not affected by p27{sup Kip1} overexpression. Conclusion: This in vitro study suggests that p27{sup Kip1} inhibits TF expression at the transcriptional level. These data indicate an interaction between p27{sup Kip1} and TF in important pathological alterations such as atherosclerosis and vascular remodeling.

  19. Anisotropic scattering in three dimensional differential approximation of radiation heat transfer

    International Nuclear Information System (INIS)

    Condiff, D.W.

    1987-01-01

    The differential approximation is extended to account for anisotropic scattering in invariant three dimensional form. A moment method using polyadic Legendre functions establishes that pressure cross sections should take precedence over extinction cross sections for treating radiation heat transfer in an absorbing, emitting, and scattering medium, and that use of these cross sections accounts for the extent of preferred forward or backwards scattering. The procedure and principle is extended to polyadic P-N approximations

  20. Limitations of the strong field approximation in ionization of the hydrogen atom by ultrashort pulses

    International Nuclear Information System (INIS)

    Arbo, D.G.; Toekesi, K.; Miraglia, J.E.; FCEN, University of Buenos Aires

    2008-01-01

    Complete text of publication follows. We presented a theoretical study of the ionization of hydrogen atoms as a result of the interaction with an ultrashort external electric field. Doubly-differential momentum distributions and angular momentum distributions of ejected electrons calculated in the framework of the Coulomb-Volkov and strong field approximations, as well as classical calculations are compared with the exact solution of the time dependent Schroedinger equation. We have shown that the Coulomb-Volkov approximation (CVA) describes the quantum atomic ionization probabilities exactly when the external field is described by a sudden momentum transfer [1]. The velocity distribution of emitted electrons right after ionization by a sudden momentum transfer is given through the strong field approximation (SFA) within both the CVA and CTMC methods. In this case, the classical and quantum time dependent evolutions of an atom subject to a sudden momentum transfer are identical. The difference between the classical and quantum final momentum distributions resides in the time evolution of the escaping electron under the subsequent action of the Coulomb field. Furthermore, classical mechanics is incapable of reproducing the quantum angular momentum distribution due to the improper initial radial distribution used in the CTMC calculations, i.e., the microcanonical ensemble. We find that in the limit of high momentum transfer, based on the SFA, there is a direct relation between the cylindrical radial distribution dP/dρ and the final angular momentum distribution dP/dL. This leads to a close analytical expression for the partial wave populations (dP/dL) SFA-Q given by dP SFA-Q / dL = 4Z 3 L 2 / (Δp) 3 K 1 (2ZL/Δp) which, together with the prescription L = l + 1/2, reproduces quite accurately the quantum (CVA) results. Considering the inverse problem, knowing the final angular momentum distribution can lead to the inference of the initial probability distribution

  1. Multigroup Approximation of Radiation Transfer in SF6 Arc Plasmas

    Directory of Open Access Journals (Sweden)

    Milada Bartlova

    2013-01-01

    Full Text Available The first order of the method of spherical harmonics (P1-approximation has been used to evaluate the radiation properties of arc plasmas of various mixtures of SF6 and PTFE ((C2F4n, polytetrafluoroethylene in the temperature range (1000 ÷ 35 000 K and pressures from 0.5 to 5 MPa. Calculations have been performed for isothermal cylindrical plasma of various radii (0.01 ÷ 10 cm. The frequency dependence of the absorption coefficients has been handled using the Planck and Rosseland averaging methods for several frequency intervals. Results obtained using various means calculated for different choices of frequency intervals are discussed.

  2. Ordered cones and approximation

    CERN Document Server

    Keimel, Klaus

    1992-01-01

    This book presents a unified approach to Korovkin-type approximation theorems. It includes classical material on the approximation of real-valuedfunctions as well as recent and new results on set-valued functions and stochastic processes, and on weighted approximation. The results are notonly of qualitative nature, but include quantitative bounds on the order of approximation. The book is addressed to researchers in functional analysis and approximation theory as well as to those that want to applythese methods in other fields. It is largely self- contained, but the readershould have a solid background in abstract functional analysis. The unified approach is based on a new notion of locally convex ordered cones that are not embeddable in vector spaces but allow Hahn-Banach type separation and extension theorems. This concept seems to be of independent interest.

  3. Variational derivation of the simplified P2 equations with boundary and interface conditions

    International Nuclear Information System (INIS)

    Tomasevic, D.I.; Larsen, E.W.

    1995-01-01

    The Simplified P 2 (SP 2 ) approximation to the transport equation is derived using a variational principle. The variational analysis yields the SP 2 equations, together with interface and Marshak-like boundary conditions. Numerical calculations show that for problems in which the P 1 solution is a reasonably accurate approximation to the transport solution, the corresponding SP 2 Solution is generally more accurate than the P 1 solution, for calculating integral quantities and detailed flux distributions, except in the close vicinity of material interfaces, where the SP 2 solution is discontinuous

  4. Statistical significance approximation in local trend analysis of high-throughput time-series data using the theory of Markov chains.

    Science.gov (United States)

    Xia, Li C; Ai, Dongmei; Cram, Jacob A; Liang, Xiaoyi; Fuhrman, Jed A; Sun, Fengzhu

    2015-09-21

    Local trend (i.e. shape) analysis of time series data reveals co-changing patterns in dynamics of biological systems. However, slow permutation procedures to evaluate the statistical significance of local trend scores have limited its applications to high-throughput time series data analysis, e.g., data from the next generation sequencing technology based studies. By extending the theories for the tail probability of the range of sum of Markovian random variables, we propose formulae for approximating the statistical significance of local trend scores. Using simulations and real data, we show that the approximate p-value is close to that obtained using a large number of permutations (starting at time points >20 with no delay and >30 with delay of at most three time steps) in that the non-zero decimals of the p-values obtained by the approximation and the permutations are mostly the same when the approximate p-value is less than 0.05. In addition, the approximate p-value is slightly larger than that based on permutations making hypothesis testing based on the approximate p-value conservative. The approximation enables efficient calculation of p-values for pairwise local trend analysis, making large scale all-versus-all comparisons possible. We also propose a hybrid approach by integrating the approximation and permutations to obtain accurate p-values for significantly associated pairs. We further demonstrate its use with the analysis of the Polymouth Marine Laboratory (PML) microbial community time series from high-throughput sequencing data and found interesting organism co-occurrence dynamic patterns. The software tool is integrated into the eLSA software package that now provides accelerated local trend and similarity analysis pipelines for time series data. The package is freely available from the eLSA website: http://bitbucket.org/charade/elsa.

  5. Gauss-Arnoldi quadrature for -1φ,φ> and rational Pade-type approximation for Markov-type functions

    International Nuclear Information System (INIS)

    Knizhnerman, L A

    2008-01-01

    The efficiency of Gauss-Arnoldi quadrature for the calculation of the quantity -1 φ,φ> is studied, where A is a bounded operator in a Hilbert space and φ is a non-trivial vector in this space. A necessary and a sufficient conditions are found for the efficiency of the quadrature in the case of a normal operator. An example of a non-normal operator for which this quadrature is inefficient is presented. It is shown that Gauss-Arnoldi quadrature is related in certain cases to rational Pade-type approximation (with the poles at Ritz numbers) for functions of Markov type and, in particular, can be used for the localization of the poles of a rational perturbation. Error estimates are found, which can also be used when classical Pade approximation does not work or it may not be efficient. Theoretical results and conjectures are illustrated by numerical experiments. Bibliography: 44 titles

  6. Scattering theory and effective medium approximations to heterogeneous materials

    International Nuclear Information System (INIS)

    Gubernatis, J.E.

    1977-01-01

    The formal analogy existing between problems studied in the microscopic theory of disordered alloys and problems concerned with the effective (macroscopic) behavior of heterogeneous materials is discussed. Attention is focused on (1) analogous approximations (effective medium approximations) developed for the microscopic problems by scattering theory concepts and techniques, but for the macroscopic problems principally by intuitive means, (2) the link, provided by scattering theory, of the intuitively developed approximations to a well-defined perturbative analysis, (3) the possible presence of conditionally convergent integrals in effective medium approximations

  7. Tau method approximation of the Hubbell rectangular source integral

    International Nuclear Information System (INIS)

    Kalla, S.L.; Khajah, H.G.

    2000-01-01

    The Tau method is applied to obtain expansions, in terms of Chebyshev polynomials, which approximate the Hubbell rectangular source integral:I(a,b)=∫ b 0 (1/(√(1+x 2 )) arctan(a/(√(1+x 2 )))) This integral corresponds to the response of an omni-directional radiation detector situated over a corner of a plane isotropic rectangular source. A discussion of the error in the Tau method approximation follows

  8. The analysis of the neutral gas measurements near comet P/Halley based on observations by VEGA-1

    International Nuclear Information System (INIS)

    Gringauz, K.I.; Verigin, M.I.; Remizov, A.P.; Oraevskij, A.A.; Szegoe, K.; Varga, A.

    1989-04-01

    The in-situ measurements of secondary electrons and sputtered ions caused by impacts of neutral particles on metallic surfaces of the Ram Faraday Cup and Plasma Impact Detector sensors in PLAZMAG-1 instrument aboard VEGA 1,2 spacecraft are used to estimate neutral particle density distribution (n n ) around comet P/Halley up to distances of approximately 3x10 σ km. Asymmetries in n n distributions along inbound and outbound legs of spacecraft trajectory are attributed to solar radiation pressure. A model calculation, taking into account solar radiation pressure, leads to 'tear drop' shaped distribution of neutral particles around the cometary nucleus. (author) 46 refs.; 11 figs

  9. Role of shake processes and inter-multiplet Auger transitions in production of multiply-charged ions upon cascade decay of resonantly excited 1s-14p state of the argon atom

    International Nuclear Information System (INIS)

    Kochur, A.G.; Dudenko, A.I.; Petrov, I.D.; Demekhin, V.F.

    2007-01-01

    The Ar i+ ion yields upon the decay of the Ar1s -1 4p state are calculated in one-electron configuration-average approximation considering shake up, shake down and shake off processes as well as the ejection of electrons in inter-multiplet Auger transitions. Our calculation underestimates the production of the higher-charged ions which may indicate limitations of the one-electron approximation, and of the step-by-step cascade model

  10. Proton induced nucleon knockout from 40Ca in the Dirac impulse approximation

    International Nuclear Information System (INIS)

    Maxwell, O.V.; Cooper, E.D.

    1989-12-01

    The (p,2p) reaction on 40 Ca at incident proton energies of 200 and 300 MeV is examined within a Dirac distorted wave impulse approximation. The relativistic Love-Franey t-matrix is evaluated at the nucleon-nucleon laboratory energy (as defined within the plane wave approximation), rather than the nucleon-nucleus laboratory energy. Particular attention is paid to the sensitivity of the calculated cross sections and analyzing powers to the properties of the bound states employed. It is found that the analyzing powers depend very little on the bound state properties, while the cross sections depend significantly only on the rms radii of the bound state wave functions. A major success of the model is its ability to fit the cross section data over a particular range of momentum transfers at both 200 and 300 MeV with the same bound state potential. Outside this momentum transfer range, the predicted cross sections are too low. The calculated analyzing powers agree well with the data at 200 MeV, but disagree with the data at 300 MeV. Values for the rms radii of the 1D 3/2 and 1D 5/2 states in 40 Ca are derived from the requirement that the peak positions of the calculated cross sections at 300 MeV agree with the empirical peak positions. Some preliminary results are also reported for neutron knockout from 40 Ca at 150 MeV

  11. Sphingosine-1-Phosphate Induces Dose-Dependent Chemotaxis or Fugetaxis of T-ALL Blasts through S1P1 Activation

    Science.gov (United States)

    Messias, Carolina V.; Santana-Van-Vliet, Eliane; Lemos, Julia P.; Moreira, Otacilio C.; Cotta-de-Almeida, Vinicius; Savino, Wilson; Mendes-da-Cruz, Daniella Arêas

    2016-01-01

    Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid involved in several physiological processes including cell migration and differentiation. S1P signaling is mediated through five G protein-coupled receptors (S1P1-S1P5). S1P1 is crucial to the exit of T-lymphocytes from the thymus and peripheral lymphoid organs through a gradient of S1P. We have previously observed that T-ALL and T-LBL blasts express S1P1. Herein we analyzed the role of S1P receptors in the migratory pattern of human T-cell neoplastic blasts. S1P-triggered cell migration was directly related to S1P1 expression. T-ALL blasts expressing low levels of S1P1 mRNA (HPB-ALL) did not migrate toward S1P, whereas those expressing higher levels of S1P1 (MOLT-4, JURKAT and CEM) did migrate. The S1P ligand induced T-ALL cells chemotaxis in concentrations up to 500 nM and induced fugetaxis in higher concentrations (1000–10000 nM) through interactions with S1P1. When S1P1 was specifically blocked by the W146 compound, S1P-induced migration at lower concentrations was reduced, whereas higher concentrations induced cell migration. Furthermore, we observed that S1P/S1P1 interactions induced ERK and AKT phosphorylation, and modulation of Rac1 activity. Responding T-ALL blasts also expressed S1P3 mRNA but blockage of this receptor did not modify migratory responses. Our results indicate that S1P is involved in the migration of T-ALL/LBL blasts, which is dependent on S1P1 expression. Moreover, S1P concentrations in the given microenvironment might induce dose-dependent chemotaxis or fugetaxis of T-ALL blasts. PMID:26824863

  12. Sphingosine-1-Phosphate Induces Dose-Dependent Chemotaxis or Fugetaxis of T-ALL Blasts through S1P1 Activation.

    Directory of Open Access Journals (Sweden)

    Carolina V Messias

    Full Text Available Sphingosine-1-phosphate (S1P is a bioactive sphingolipid involved in several physiological processes including cell migration and differentiation. S1P signaling is mediated through five G protein-coupled receptors (S1P1-S1P5. S1P1 is crucial to the exit of T-lymphocytes from the thymus and peripheral lymphoid organs through a gradient of S1P. We have previously observed that T-ALL and T-LBL blasts express S1P1. Herein we analyzed the role of S1P receptors in the migratory pattern of human T-cell neoplastic blasts. S1P-triggered cell migration was directly related to S1P1 expression. T-ALL blasts expressing low levels of S1P1 mRNA (HPB-ALL did not migrate toward S1P, whereas those expressing higher levels of S1P1 (MOLT-4, JURKAT and CEM did migrate. The S1P ligand induced T-ALL cells chemotaxis in concentrations up to 500 nM and induced fugetaxis in higher concentrations (1000-10000 nM through interactions with S1P1. When S1P1 was specifically blocked by the W146 compound, S1P-induced migration at lower concentrations was reduced, whereas higher concentrations induced cell migration. Furthermore, we observed that S1P/S1P1 interactions induced ERK and AKT phosphorylation, and modulation of Rac1 activity. Responding T-ALL blasts also expressed S1P3 mRNA but blockage of this receptor did not modify migratory responses. Our results indicate that S1P is involved in the migration of T-ALL/LBL blasts, which is dependent on S1P1 expression. Moreover, S1P concentrations in the given microenvironment might induce dose-dependent chemotaxis or fugetaxis of T-ALL blasts.

  13. Finite-temperature random-phase approximation for spectroscopic properties of neon plasmas

    International Nuclear Information System (INIS)

    Colgan, J.; Collins, L. A.; Fontes, C. J.; Csanak, G.

    2007-01-01

    A finite-temperature random-phase approximation (FTRPA) is applied to calculate oscillator strengths for excitations in hot and dense plasmas. Application of the FTRPA provides a convenient, self-consistent method with which to explore coupled-channel effects of excited electrons in a dense plasma. We present FTRPA calculations that include coupled-channel effects. The inclusion of these effects is shown to cause significant differences in the oscillator strength for a prototypical case of 1 P excitation in neon when compared with single-channel and with average-atom calculations. Trends as a function of temperature and density are also discussed

  14. Murine K2P5.1 Deficiency Has No Impact on Autoimmune Neuroinflammation due to Compensatory K2P3.1- and KV1.3-Dependent Mechanisms

    Directory of Open Access Journals (Sweden)

    Stefan Bittner

    2015-07-01

    Full Text Available Lymphocytes express potassium channels that regulate physiological cell functions, such as activation, proliferation and migration. Expression levels of K2P5.1 (TASK2; KCNK5 channels belonging to the family of two-pore domain potassium channels have previously been correlated to the activity of autoreactive T lymphocytes in patients with multiple sclerosis and rheumatoid arthritis. In humans, K2P5.1 channels are upregulated upon T cell stimulation and influence T cell effector functions. However, a further clinical translation of targeting K2P5.1 is currently hampered by a lack of highly selective inhibitors, making it necessary to evaluate the impact of KCNK5 in established preclinical animal disease models. We here demonstrate that K2P5.1 knockout (K2P5.1−/− mice display no significant alterations concerning T cell cytokine production, proliferation rates, surface marker molecules or signaling pathways. In an experimental model of autoimmune neuroinflammation, K2P5.1−/− mice show a comparable disease course to wild-type animals and no major changes in the peripheral immune system or CNS compartment. A compensatory upregulation of the potassium channels K2P3.1 and KV1.3 seems to counterbalance the deletion of K2P5.1. As an alternative model mimicking autoimmune neuroinflammation, experimental autoimmune encephalomyelitis in the common marmoset has been proposed, especially for testing the efficacy of new potential drugs. Initial experiments show that K2P5.1 is functionally expressed on marmoset T lymphocytes, opening up the possibility for assessing future K2P5.1-targeting drugs.

  15. January: IBM 7094 programme for the resolution of cell problems in planar, spherical and cylindrical geometry using the double Pn approximation

    International Nuclear Information System (INIS)

    Amouyal, A.; Tariel, H.

    1966-01-01

    Code name: January 1 st SCEA 011S. 2) Computer: IBM 7094; Programme system: Fortran II, 2 nd version. 3) Nature of the problem: resolution of cell problems with one space variable (planar, spherical and cylindrical geometries) and with one energy group, with isotropic sources in the double P n approximation (DP 1 and DP 3 approximation in planar and spherical geometries, DP 1 and DP 2 in cylindrical geometry). 4) Method used: the differential equations with limiting conditions are transformed into differential system with initial conditions which are integrated by a separate-step method. 5) Restrictions: number of physical media [fr

  16. Approximations and Implementations of Nonlinear Filtering Schemes.

    Science.gov (United States)

    1988-02-01

    sias k an Ykar repctively the input and the output vectors. Asfold. First, there are intrinsic errors, due to explained in the previous section, the...e.g.[BV,P]). In the above example of a a-algebra, the distributive property SIA (S 2vS3) - (SIAS2)v(SIAS3) holds. A complete orthocomplemented...process can be approximated by a switched Control Systems: Stochastic Stability and parameter process depending on the aggregated slow Dynamic Relaibility

  17. Ab Initio Description of Disordered Sr1−xKxFe2As2 Using the Coherent Potential Approximation

    KAUST Repository

    Pulikkotil, J. J.; Schwingenschlö gl, Udo

    2010-01-01

    The electronic structure of disordered Sr1−xKxFe2As2 is studied by ab initio density functional theory. As no superstructure and/or atomic short range ordering is reported for Sr1−xKxFe2As2, the coherent potential approximation can be used

  18. LMFBR transducer performance in SLSF tests P1 and P2

    International Nuclear Information System (INIS)

    English, J.J.; Anderson, T.T.; Kuzay, T.M.; Wilson, R.E.; Pedersen, D.R.; Kaiser, W.C.; Klingler, W.B.

    1977-01-01

    The reliability and problem areas of sodium-immersed thermocouples, pressure transducers and flowmeters are presented for experiments P1 and P2 of the Sodium Loop Safety Facility (SLSF). The SLSF is a doubly-contained sodium loop situated in a core position of the Engineering Test Reactor at the Idaho National Engineering Laboratory

  19. Use of a pitot-static probe for determining wing section drag in flight at Mach numbers from 0.5 to approximately 1.0

    Science.gov (United States)

    Montoya, L. C.; Economu, M. A.; Cissell, R. E.

    1974-01-01

    The use of a pitot-static probe to determine wing section drag at speeds from Mach 0.5 to approximately 1.0 was evaluated in flight. The probe unit is described and operational problems are discussed. Typical wake profiles and wing section drag coefficients are presented. The data indicate that the pitot-static probe gave reliable results up to speeds of approximately 1.0.

  20. Complexity of Gaussian-Radial-Basis Networks Approximating Smooth Functions

    Czech Academy of Sciences Publication Activity Database

    Kainen, P.C.; Kůrková, Věra; Sanguineti, M.

    2009-01-01

    Roč. 25, č. 1 (2009), s. 63-74 ISSN 0885-064X R&D Projects: GA ČR GA201/08/1744 Institutional research plan: CEZ:AV0Z10300504 Keywords : Gaussian-radial-basis-function networks * rates of approximation * model complexity * variation norms * Bessel and Sobolev norms * tractability of approximation Subject RIV: IN - Informatics, Computer Science Impact factor: 1.227, year: 2009

  1. Metastatic triple-negative breast cancer is dependent on SphKs/S1P signaling for growth and survival.

    Science.gov (United States)

    Maiti, Aparna; Takabe, Kazuaki; Hait, Nitai C

    2017-04-01

    About 40,000 American women die from metastatic breast cancer each year despite advancements in treatment. Approximately, 15% of breast cancers are triple-negative for estrogen receptor, progesterone receptor, and HER2. Triple-negative cancer is characterized by more aggressive, harder to treat with conventional approaches and having a greater possibility of recurrence. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid signaling mediator has emerged as a key regulatory molecule in breast cancer progression. Therefore, we investigated whether cytosolic sphingosine kinase type 1 (SphK1) and nuclear sphingosine kinase type 2 (SphK2), the enzymes that make S1P are critical for growth and PI3K/AKT, ERK-MAP kinase mediated survival signaling of lung metastatic variant LM2-4 breast cancer cells, generated from the parental triple-negative MDA-MB-231 human breast cancer cell line. Similar with previous report, SphKs/S1P signaling is critical for the growth and survival of estrogen receptor positive MCF-7 human breast cancer cells, was used as our study control. MDA-MB-231 did not show a significant effect of SphKs/S1P signaling on AKT, ERK, and p38 pathways. In contrast, LM2-4 cells that gained lung metastatic phenotype from primary MDA-MB-231 cells show a significant effect of SphKs/S1P signaling requirement on cell growth, survival, and cell motility. PF-543, a selective potent inhibitor of SphK1, attenuated epidermal growth factor (EGF)-mediated cell growth and survival signaling through inhibition of AKT, ERK, and p38 MAP kinase pathways mainly in LM2-4 cells but not in parental MDA-MB-231 human breast cancer cells. Moreover, K-145, a selective inhibitor of SphK2, markedly attenuated EGF-mediated cell growth and survival of LM2-4 cells. We believe this study highlights the importance of SphKs/S1P signaling in metastatic triple-negative breast cancers and targeted therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Effect of orbital alignment on the forward and reverse electronic energy transfer Ca(4s5p 1P1)+Marrow-right-leftCa(4s5p 3P/sub J/)+M with rare gases

    International Nuclear Information System (INIS)

    Bussert, W.; Neuschaefer, D.; Leone, S.R.; Departments of Physics and Chemistry, University of Colorado, Boulder, Colorado 80309-0440)

    1987-01-01

    Effects of orbital alignment on the relative cross sections for electronic energy transfer are determined for the near resonant transfer between Ca(4s5p 1 P 1 ) and Ca(4s5p 3 P/sub J/) states with rare gas collision partners. The experiments are carried out by pulsed laser excitation in a crossed beam. The results for the forward direction, 1 P to 3 P, formulated in terms of the ratio of the maximum to minimum transfer probability are: 3 He 1.61 +- 0.05; He 1.60 +- 0.03; Ne 1.55 +- 0.10; Ar 1.52 +- 0.21; for Kr, transfer occurs, but no preference is distinguishable within 1 +- 0.2; Xe 1.44 +- 0.06. The results for He, Ne, and Ar indicate a clear preference in the transfer for the initially prepared molecular Pi state. For Xe the molecular Σ state is dominant. The energy transfer is also carried out in the reverse direction, 3 P 1 to 1 P, for He and Xe, obtaining 1.65 +- 0.10 and 1.94 +- 0.22, respectively. Analysis of the state preparation suggests that the reverse direction favors the asymptotic molecular Σ state for He and the molecular Pi state for Xe. These alignment results provide a first experimental determination of the dominant electronic states involved in a collisional energy transfer process

  3. Cytochrome P2A13 and P1A1 gene polymorphisms are associated with the occurrence of uterine leiomyoma.

    Science.gov (United States)

    Herr, D; Bettendorf, H; Denschlag, D; Keck, C; Pietrowski, D

    2006-10-01

    To investigate the association between the occurrence of uterine leiomyoma and two SNPs of the CYP 2A13 and CYP 1A1 genes. Prospective case control study with 132 women with clinically and surgically diagnosed uterine leiomyoma and 260 controls. Genotyping was performed by polymerase chain reaction (PCR) based amplification of CYP 2A13 and CYP 1A1 genes, and restriction fragment length polymorphism (RFLP) analysis. Comparing women with uterine leiomyoma and controls, we demonstrate statistical significant differences of allele frequency and genotype distribution for the CYP 1A1 polymorphism (P = 0.025 and P = 0.046, respectively). Furthermore, for the CYP 2A13 polymorphism we found a significant difference concerning allele frequency (P = 0.033). However, for the genotype distribution, only borderline significance was observed (P = 0.064). The CYP 2A13 and CYP 1A1 SNPs are associated with uterine leiomyoma in a Caucasian population and may contribute to the understanding of the pathogenic mechanisms of uterine leiomyoma.

  4. The subcellular distribution of the human ribosomal "stalk" components: P1, P2 and P0 proteins

    DEFF Research Database (Denmark)

    Tchórzewski, Marek; Krokowski, Dawid; Rzeski, Wojciech

    2003-01-01

    The ribosomal "stalk" structure is a distinct lateral protuberance located on the large ribosomal subunit in prokaryotic, as well as in eukaryotic cells. In eukaryotes, this ribosomal structure is composed of the acidic ribosomal P proteins, forming two hetero-dimers (P1/P2) attached...

  5. Oncogenic S1P signalling in EBV-associated nasopharyngeal carcinoma activates AKT and promotes cell migration through S1P receptor 3.

    Science.gov (United States)

    Lee, Hui Min; Lo, Kwok-Wai; Wei, Wenbin; Tsao, Sai Wah; Chung, Grace Tin Yun; Ibrahim, Maha Hafez; Dawson, Christopher W; Murray, Paul G; Paterson, Ian C; Yap, Lee Fah

    2017-05-01

    Undifferentiated nasopharyngeal carcinoma (NPC) is a cancer with high metastatic potential that is consistently associated with Epstein-Barr virus (EBV) infection. In this study, we have investigated the functional contribution of sphingosine-1-phosphate (S1P) signalling to the pathogenesis of NPC. We show that EBV infection or ectopic expression of the EBV-encoded latent genes (EBNA1, LMP1, and LMP2A) can up-regulate sphingosine kinase 1 (SPHK1), the key enzyme that produces S1P, in NPC cell lines. Exogenous addition of S1P promotes the migration of NPC cells through the activation of AKT; shRNA knockdown of SPHK1 resulted in a reduction in the levels of activated AKT and inhibition of cell migration. We also show that S1P receptor 3 (S1PR3) mRNA is overexpressed in EBV-positive NPC patient-derived xenografts and a subset of primary NPC tissues, and that knockdown of S1PR3 suppressed the activation of AKT and the S1P-induced migration of NPC cells. Taken together, our data point to a central role for EBV in mediating the oncogenic effects of S1P in NPC and identify S1P signalling as a potential therapeutic target in this disease. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  6. Contribution to the study of 12C excited levels resulting from the reactions 11B (P/ α0) and 11B (p, α1)

    International Nuclear Information System (INIS)

    Longequeue, J.P.

    1963-11-01

    This work is made up of two parts. In the first part the differential cross-sections have been determined of the reactions 11 B (p,α) from 130 to 500 keV thus confirming, at the 163 keV resonance, the (2 + ) characteristics of the 16.11 MeV level of 12 C. Furthermore, the experimental results in the neighbourhood of the 163 keV resonance can be explained by the interference of the 12 C levels: 2 + at 16.11 MeV and 1 - at 17.23 MeV for the α 0 , 2 + at 16.11 MeV and 2 - at 16.58 MeV for the α 1 . In the second part the (α -8Be ) disintegration process of 12 C has been studied in the neighbourhood of the 16.11 MeV level. It is shown that, if the (α -8Be ) mode of disintegration is preponderant outside the E p = 163 keV resonance, it is also preponderant at this same resonance; a direct disintegration of the 12 C to 3 α, with an approximate magnitude of 40 per cent has however not been excluded. (author) [fr

  7. Computational modeling of fully-ionized, magnetized plasmas using the fluid approximation

    Science.gov (United States)

    Schnack, Dalton

    2005-10-01

    Strongly magnetized plasmas are rich in spatial and temporal scales, making a computational approach useful for studying these systems. The most accurate model of a magnetized plasma is based on a kinetic equation that describes the evolution of the distribution function for each species in six-dimensional phase space. However, the high dimensionality renders this approach impractical for computations for long time scales in relevant geometry. Fluid models, derived by taking velocity moments of the kinetic equation [1] and truncating (closing) the hierarchy at some level, are an approximation to the kinetic model. The reduced dimensionality allows a wider range of spatial and/or temporal scales to be explored. Several approximations have been used [2-5]. Successful computational modeling requires understanding the ordering and closure approximations, the fundamental waves supported by the equations, and the numerical properties of the discretization scheme. We review and discuss several ordering schemes, their normal modes, and several algorithms that can be applied to obtain a numerical solution. The implementation of kinetic parallel closures is also discussed [6].[1] S. Chapman and T.G. Cowling, ``The Mathematical Theory of Non-Uniform Gases'', Cambridge University Press, Cambridge, UK (1939).[2] R.D. Hazeltine and J.D. Meiss, ``Plasma Confinement'', Addison-Wesley Publishing Company, Redwood City, CA (1992).[3] L.E. Sugiyama and W. Park, Physics of Plasmas 7, 4644 (2000).[4] J.J. Ramos, Physics of Plasmas, 10, 3601 (2003).[5] P.J. Catto and A.N. Simakov, Physics of Plasmas, 11, 90 (2004).[6] E.D. Held et al., Phys. Plasmas 11, 2419 (2004)

  8. Immunological and biological properties of recombinant Lol p 1.

    Science.gov (United States)

    Boutin, Y; Lamontagne, P; Boulanger, J; Brunet, C; Hébert, J

    1997-03-01

    Current forms of allergy diagnosis and therapies are based on the use of natural allergenic extracts. Despite strong evidence that higher therapeutic efficacy may be achieved with purified allergens, the purification of multiple allergic components from extracts is a fastidious and sometimes an impossible task. However, the use of recombinant allergens may be an alternative to overcome this problem. In this study, we compared the immunological properties of recombinant (r) Lol p 1 with those of the natural protein. We cloned directly the gene encoding Lol p 1 from genomic DNA of ryegrass pollen. This gene was subcloned into the expression vector pMAL-c and expressed as fusion protein. Subsequently, rLol p 1 was cleaved from maltose-binding protein using factor Xa. Using binding inhibition and proliferative assays, we assessed the immunological properties of the recombinant allergens. The capacity of rLol p 1 to trigger basophil histamine release and to elicit a skin reaction was also assessed and compared to those of its natural counterpart. We found that the Lol p 1 gene has no introns since we amplified this gene directly from genomic DNA. We demonstrated that the binding sites of anti-Lol p 1 monoclonal antibody, specific human IgG and IgE antibody are well conserved on rLol p 1 as no difference in the binding inhibition profile was observed when using either natural or recombinant protein. At the T-cell level, rLol p 1 elicited a T-cell response in mice comparable to that observed with the natural protein. In addition, we demonstrated that the biological characteristics of rLol p 1 were comparable to those of the natural counterpart, in that rLol p 1 elicited a skin wheal reaction and induced basophil histamine release in grass-allergic patients only. The data indicate that natural Lol p 1 and rLol p 1 shared identical immunological and biological properties.

  9. A multi scale approximation solution for the time dependent Boltzmann-transport equation

    International Nuclear Information System (INIS)

    Merk, B.

    2004-03-01

    once more compared with the exact analytical solution obtaining good agreement. In the next steps multiple scale expansion solutions are developed for the space-time dependent P 1 and P 3 transport equations for the homogenized cell and 2 delayed neutorn groups. These results are analysed versus the solution for the diffusion equation emphasizing the differences in the space-time structure between the time dependent diffusion- and transport solutions. The effect of the additional derivation terms in the transport equations can be observed during the analytical expansion process and in the graphical analysis of the differences between the solutions. The developed solution is tested for direct calculation of the time behaviour of single nodes in the framework of a nodal code and the results are compared. It is evident that the nature of the inserted perturbation has major impact on the discrepancy of the results compared to the reference nodal method. (orig.) [de

  10. Likelihood Approximation With Parallel Hierarchical Matrices For Large Spatial Datasets

    KAUST Repository

    Litvinenko, Alexander; Sun, Ying; Genton, Marc G.; Keyes, David E.

    2017-01-01

    The main goal of this article is to introduce the parallel hierarchical matrix library HLIBpro to the statistical community. We describe the HLIBCov package, which is an extension of the HLIBpro library for approximating large covariance matrices and maximizing likelihood functions. We show that an approximate Cholesky factorization of a dense matrix of size $2M\\times 2M$ can be computed on a modern multi-core desktop in few minutes. Further, HLIBCov is used for estimating the unknown parameters such as the covariance length, variance and smoothness parameter of a Matérn covariance function by maximizing the joint Gaussian log-likelihood function. The computational bottleneck here is expensive linear algebra arithmetics due to large and dense covariance matrices. Therefore covariance matrices are approximated in the hierarchical ($\\H$-) matrix format with computational cost $\\mathcal{O}(k^2n \\log^2 n/p)$ and storage $\\mathcal{O}(kn \\log n)$, where the rank $k$ is a small integer (typically $k<25$), $p$ the number of cores and $n$ the number of locations on a fairly general mesh. We demonstrate a synthetic example, where the true values of known parameters are known. For reproducibility we provide the C++ code, the documentation, and the synthetic data.

  11. Likelihood Approximation With Parallel Hierarchical Matrices For Large Spatial Datasets

    KAUST Repository

    Litvinenko, Alexander

    2017-11-01

    The main goal of this article is to introduce the parallel hierarchical matrix library HLIBpro to the statistical community. We describe the HLIBCov package, which is an extension of the HLIBpro library for approximating large covariance matrices and maximizing likelihood functions. We show that an approximate Cholesky factorization of a dense matrix of size $2M\\\\times 2M$ can be computed on a modern multi-core desktop in few minutes. Further, HLIBCov is used for estimating the unknown parameters such as the covariance length, variance and smoothness parameter of a Matérn covariance function by maximizing the joint Gaussian log-likelihood function. The computational bottleneck here is expensive linear algebra arithmetics due to large and dense covariance matrices. Therefore covariance matrices are approximated in the hierarchical ($\\\\H$-) matrix format with computational cost $\\\\mathcal{O}(k^2n \\\\log^2 n/p)$ and storage $\\\\mathcal{O}(kn \\\\log n)$, where the rank $k$ is a small integer (typically $k<25$), $p$ the number of cores and $n$ the number of locations on a fairly general mesh. We demonstrate a synthetic example, where the true values of known parameters are known. For reproducibility we provide the C++ code, the documentation, and the synthetic data.

  12. Hunt for the 11P1 bound state of charmonium

    International Nuclear Information System (INIS)

    Porter, F.C.

    1982-02-01

    Using the Crystal Ball detector at SPEAR, we have looked for evidence of the isospin-violating decay psi' → π 01 P 1 , where 1 P 1 is the predicted spin-singlet p-wave bound state of charmonium. For a 1 P 1 state at the predicted mass (approx. 3520 MeV), we obtain the 95% confidence level limits: BR(psi' → π 01 P 1 ) 01 P 1 )BR( 1 P 1 → γn/sub c/ < 0.14%. These limits are compared with simple theoretical predictions

  13. CONTRIBUTIONS TO RATIONAL APPROXIMATION,

    Science.gov (United States)

    Some of the key results of linear Chebyshev approximation theory are extended to generalized rational functions. Prominent among these is Haar’s...linear theorem which yields necessary and sufficient conditions for uniqueness. Some new results in the classic field of rational function Chebyshev...Furthermore a Weierstrass type theorem is proven for rational Chebyshev approximation. A characterization theorem for rational trigonometric Chebyshev approximation in terms of sign alternation is developed. (Author)

  14. Optical properties of lattice matched InxGa1-xP1-yNy heteroepitaxial layers on GaP

    International Nuclear Information System (INIS)

    Imanishi, T.; Wakahara, A.; Kim, S.M.; Yonezu, H.; Furukawa, Y.

    2005-01-01

    Optical constants and band structure of In x Ga 1-x P 1-y N y lattice matched to GaP (100) substrate are investigated. Nitrogen concentration in the film estimated by X-ray diffraction and X-ray photoelectron spectroscopy, was 1.4%, 1.8% and 3.5%. Refractive index and transition critical points E 0 (Γ v to Γ c ), E 1 (L v to L c ) and E 2 (X v to X c ) are evaluated by spectroscopic ellipsometry. When N composition increases from 1.4% to 3.5%, both photoluminescence (PL) peak energy, E PL , and E 0 shift to lower energy, and the energy difference ΔE=E 0 -E PL decrease from 380 meV to 110 meV. The large red-sift of E PL from the E 0 suggest that the luminescence is of defect-related luminescence, and crossover point of indirect band structure estimated by the extrapolation of N-composition dependence of ΔE is estimated to be around in In 0.1 Ga 0.9 P 0.96 N 0.04 . (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Randomized Phase I: Safety, Immunogenicity and Mucosal Antiviral Activity in Young Healthy Women Vaccinated with HIV-1 Gp41 P1 Peptide on Virosomes.

    Directory of Open Access Journals (Sweden)

    Geert Leroux-Roels

    Full Text Available Mucosal antibodies harboring various antiviral activities may best protect mucosal surfaces against early HIV-1 entry at mucosal sites and they should be ideally induced by prophylactic HIV-1 vaccines for optimal prevention of sexually transmitted HIV-1. A phase I, double-blind, randomized, placebo-controlled trial was conducted in twenty-four healthy HIV-uninfected young women. The study objectives were to assess the safety, tolerability and immunogenicity of virosomes harboring surface HIV-1 gp41-derived P1 lipidated peptides (MYM-V101. Participants received placebo or MYM-V101 vaccine at 10 μg/dose or 50 μg/dose intramuscularly at week 0 and 8, and intranasally at week 16 and 24. MYM-V101 was safe and well-tolerated at both doses administered by the intramuscular and intranasal routes, with the majority of subjects remaining free of local and general symptoms. P1-specific serum IgGs and IgAs were induced in all high dose recipients after the first injection. After the last vaccination, vaginal and rectal P1-specific IgGs could be detected in all high dose recipients. Approximately 63% and 43% of the low and high dose recipients were respectively tested positive for vaginal P1-IgAs, while 29% of the subjects from the high dose group tested positive for rectal IgAs. Serum samples had total specific IgG and IgA antibody concentrations ≥ 0.4 μg/mL, while mucosal samples were usually below 0.01 μg/mL. Vaginal secretions from MYM-V101 vaccinated subjects were inhibiting HIV-1 transcytosis but had no detectable neutralizing activity. P1-specific Th1 responses could not be detected on PBMC. This study demonstrates the excellent safety and tolerability of MYM-V101, eliciting systemic and mucosal antibodies in the majority of subjects. Vaccine-induced mucosal anti-gp41 antibodies toward conserved gp41 motifs were harboring HIV-1 transcytosis inhibition activity and may contribute to reduce sexually-transmitted HIV-1.ClinicalTrials.gov NCT01084343.

  16. WKB approximation in atomic physics

    International Nuclear Information System (INIS)

    Karnakov, Boris Mikhailovich

    2013-01-01

    Provides extensive coverage of the Wentzel-Kramers-Brillouin approximation and its applications. Presented as a sequence of problems with highly detailed solutions. Gives a concise introduction for calculating Rydberg states, potential barriers and quasistationary systems. This book has evolved from lectures devoted to applications of the Wentzel-Kramers-Brillouin- (WKB or quasi-classical) approximation and of the method of 1/N -expansion for solving various problems in atomic and nuclear physics. The intent of this book is to help students and investigators in this field to extend their knowledge of these important calculation methods in quantum mechanics. Much material is contained herein that is not to be found elsewhere. WKB approximation, while constituting a fundamental area in atomic physics, has not been the focus of many books. A novel method has been adopted for the presentation of the subject matter, the material is presented as a succession of problems, followed by a detailed way of solving them. The methods introduced are then used to calculate Rydberg states in atomic systems and to evaluate potential barriers and quasistationary states. Finally, adiabatic transition and ionization of quantum systems are covered.

  17. Chemical and genetic tools to explore S1P biology.

    Science.gov (United States)

    Cahalan, Stuart M

    2014-01-01

    The zwitterionic lysophospholipid Sphingosine 1-Phosphate (S1P) is a pleiotropic mediator of physiology and pathology. The synthesis, transport, and degradation of S1P are tightly regulated to ensure that S1P is present in the proper concentrations in the proper location. The binding of S1P to five G protein-coupled S1P receptors regulates many physiological systems, particularly the immune and vascular systems. Our understanding of the functions of S1P has been aided by the tractability of the system to both chemical and genetic manipulation. Chemical modulators have been generated to affect most of the known components of S1P biology, including agonists of S1P receptors and inhibitors of enzymes regulating S1P production and degradation. Genetic knockouts and manipulations have been similarly engineered to disrupt the functions of individual S1P receptors or enzymes involved in S1P metabolism. This chapter will focus on the development and utilization of these chemical and genetic tools to explore the complex biology surrounding S1P and its receptors, with particular attention paid to the in vivo findings that these tools have allowed for.

  18. Function approximation using combined unsupervised and supervised learning.

    Science.gov (United States)

    Andras, Peter

    2014-03-01

    Function approximation is one of the core tasks that are solved using neural networks in the context of many engineering problems. However, good approximation results need good sampling of the data space, which usually requires exponentially increasing volume of data as the dimensionality of the data increases. At the same time, often the high-dimensional data is arranged around a much lower dimensional manifold. Here we propose the breaking of the function approximation task for high-dimensional data into two steps: (1) the mapping of the high-dimensional data onto a lower dimensional space corresponding to the manifold on which the data resides and (2) the approximation of the function using the mapped lower dimensional data. We use over-complete self-organizing maps (SOMs) for the mapping through unsupervised learning, and single hidden layer neural networks for the function approximation through supervised learning. We also extend the two-step procedure by considering support vector machines and Bayesian SOMs for the determination of the best parameters for the nonlinear neurons in the hidden layer of the neural networks used for the function approximation. We compare the approximation performance of the proposed neural networks using a set of functions and show that indeed the neural networks using combined unsupervised and supervised learning outperform in most cases the neural networks that learn the function approximation using the original high-dimensional data.

  19. Hydrogen passivation of N(+)-P and P(+)-N heteroepitaxial InP solar cell structures

    Science.gov (United States)

    Chatterjee, Basab; Davis, William C.; Ringel, Steve A.; Hoffman, Richard, Jr.

    1996-01-01

    Dislocations and related point defect complexes caused by lattice mismatch currently limit the performance of heteroepitaxial InP cells by introducing shunting paths across the active junction and by the formation of deep traps within the base region. We have previously demonstrated that plasma hydrogenation is an effective and stable means to passivate the electrical activity of such defects in specially designed heteroepitaxial InP test structures to probe hydrogen passivation at typical base depths within a cell structure. In this work, we present our results on the hydrogen passivation of actual heteroepitaxial n-p and p-n InP cell structures grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD). We have found that a 2 hour exposure to a 13.56 MHz hydrogen plasma at 275 C reduces the deep level concentration in the base regions of both n(+)-p and p(+)-n heteroepitaxial InP cell structures from as-grown values of 5-7 x 10(exp 14) cm(exp -3), down to 3-5 x 10(exp 12) cm(exp -3). All dopants were successfully reactivated by a 400 C, 5 minute anneal with no detectable activation of deep levels. One to five analysis indicated a subsequent approximately 100 fold decrease in reverse leakage current at -1 volt reverse bias, and an improved built in voltage for the p(+)-n structures. In addition to being passivated, dislocations are also shown to participate in secondary interactions during hydrogenation. We find that the presence of dislocations enhances hydrogen diffusion into the cell structure, and lowers the apparent dissociation energy of Zn-H complexes from 1.19 eV for homoepitaxial Zn-doped InP to 1.12 eV for heteroepitaxial Zn-doped InP. This is explained by additional hydrogen trapping at dislocations subsequent to the reactivation of Zn dopants after hydrogenation.

  20. Exact constants in approximation theory

    CERN Document Server

    Korneichuk, N

    1991-01-01

    This book is intended as a self-contained introduction for non-specialists, or as a reference work for experts, to the particular area of approximation theory that is concerned with exact constants. The results apply mainly to extremal problems in approximation theory, which in turn are closely related to numerical analysis and optimization. The book encompasses a wide range of questions and problems: best approximation by polynomials and splines; linear approximation methods, such as spline-approximation; optimal reconstruction of functions and linear functionals. Many of the results are base

  1. Optimization of 1.3-μm InGaAsP/InP Electro-Absorption Modulator

    International Nuclear Information System (INIS)

    Wang Hui-Tao; Zhou Dai-Bing; Zhang Rui-Kang; Lu Dan; Zhao Ling-Juan; Zhu Hong-Liang; Wang Wei; Ji Chen

    2015-01-01

    We report the simulation and experimental results of 1.3-μm InGaAsP/InP multiple quantum well (MQW) electro-absorption modulators (EAMs). In this work, the quantum confined Stark effect of the EAM is systematically analyzed through the finite element method. An optimized structure of the 1.3-μm InGaAsP/InP QW EAM is proposed for applications in 100 G ethernet. Then 1.3-μm InGaAsP/InP EAMs with f_−_3 _d_B bandwidth of over 20 GHz and extinction ratio over 20 dB at 3 V bias voltage are demonstrated. (paper)

  2. Closed expressions for $\\int_{0}^{1} t^{-1} log^{n-1}t log^{p}(1 - t) dt$

    CERN Document Server

    Kölbig, Kurt Siegfried

    1982-01-01

    Closed expressions for the integral integral /sub 0//sup 1/ t/sup -1/ log/sup n-1/t log/sup p/(1-t)dt, whose general form is given elsewhere, are listed for n=1(1)9, p=1(1)9. A formula is derived which allows an easy evaluation of these expressions by formula manipulation on a computer. The majority of the above expressions are given in a microfiche supplement to the paper.

  3. The impact of nonpolar lipids on the regulation of the steryl ester hydrolases Tgl1p and Yeh1p in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Klein, Isabella; Korber, Martina; Athenstaedt, Karin; Daum, Günther

    2017-12-01

    In the yeast Saccharomyces cerevisiae degradation of steryl esters is catalyzed by the steryl ester hydrolases Tgl1p, Yeh1p and Yeh2p. The two steryl ester hydrolases Tgl1p and Yeh1p localize to lipid droplets, a cell compartment storing steryl esters and triacylglycerols. In the present study we investigated regulatory aspects of these two hydrolytic enzymes, namely the gene expression level, protein amount, stability and enzyme activity of Tgl1p and Yeh1p in strains lacking both or only one of the two major nonpolar lipids, steryl esters and triacylglycerols. In a strain lacking both nonpolar lipids and consequently lipid droplets, Tgl1p as well as Yeh1p were present at low amount, became highly unstable compared to wild-type cells, and lost their enzymatic activity. Under these conditions both steryl ester hydrolases were retained in the endoplasmic reticulum. The lack of steryl esters alone was not sufficient to cause an altered intracellular localization of Tgl1p and Yeh1p. Surprisingly, the stability of Tgl1p and Yeh1p was markedly reduced in a strain lacking triacylglycerols, but their capacity to mobilize steryl esters remained unaffected. We also tested a possible cross-regulation of Tgl1p and Yeh1p by analyzing the behavior of each hydrolase in the absence of its counterpart steryl ester hydrolases. In summary, this study demonstrates a strong regulation of the two lipid droplet associated steryl ester hydrolases Tgl1p and Yeh1p due to the presence/absence of their host organelle. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. APPROXIMATION OF FREE-FORM CURVE – AIRFOIL SHAPE

    Directory of Open Access Journals (Sweden)

    CHONG PERK LIN

    2013-12-01

    Full Text Available Approximation of free-form shape is essential in numerous engineering applications, particularly in automotive and aircraft industries. Commercial CAD software for the approximation of free-form shape is based almost exclusively on parametric polynomial and rational parametric polynomial. The parametric curve is defined by vector function of one independent variable R(u = (x(u, y(u, z(u, where 0≤u≤1. Bézier representation is one of the parametric functions, which is widely used in the approximating of free-form shape. Given a string of points with the assumption of sufficiently dense to characterise airfoil shape, it is desirable to approximate the shape with Bézier representation. The expectation is that the representation function is close to the shape within an acceptable working tolerance. In this paper, the aim is to explore the use of manual and automated methods for approximating section curve of airfoil with Bézier representation.

  5. K-n and K-p elastic scattering in K-d collisions from 1.2 to 2.2 GeV/c

    International Nuclear Information System (INIS)

    Declais, Y.; Duchon, J.; Louvel, M.; Patry, J.-P.; Seguinot, J.; Baillon, P.; Bruman, C.; Ferro-Luzzi, M.; Perreau, J.-M.; Ypsilantis, T.

    1977-01-01

    This report contains the detailed description of an experiment which has determined the differential cross section of the K - n→K - n elastic scattering reaction. The results are 12 angular distributions spanning the K - n c.m. energy interval from approximately 1.86 to approximately 2.32 GeV. The measurements have been performed at the CERN PS using a beam of negative kaons with momenta from 1.2 to 2.2 GeV/c incident on a liquid deuterium target. By means of electronic apparatus the process K - d→K - n psub(s) was identified and recorded; this process is basically the same as the K - n elastic reaction insofar as the spectator proton psub(s) has low momentum. The elastic reaction was derived from the above process by taking into account the Fermi motion of the target neutron and by introducing the appropriate corrections to compensate for the effects due to the composite nature of the neutron (double-scattering, final state interaction). These results, constituting the first extensive collection of data on the pure isospin 1 anti KN state have been used in conjunction with other data in a preliminary partial wave analysis of the anti KN elastic system over the c.m. energy range from 1.84 to 2.23 GeV. Mainly for testing purposes, a similar amount of data has been collected for the K - p elastic reaction also from K - d collisions (K - d→K - p nsub(s)). (Auth.)

  6. Conference on Abstract Spaces and Approximation

    CERN Document Server

    Szökefalvi-Nagy, B; Abstrakte Räume und Approximation; Abstract spaces and approximation

    1969-01-01

    The present conference took place at Oberwolfach, July 18-27, 1968, as a direct follow-up on a meeting on Approximation Theory [1] held there from August 4-10, 1963. The emphasis was on theoretical aspects of approximation, rather than the numerical side. Particular importance was placed on the related fields of functional analysis and operator theory. Thirty-nine papers were presented at the conference and one more was subsequently submitted in writing. All of these are included in these proceedings. In addition there is areport on new and unsolved problems based upon a special problem session and later communications from the partici­ pants. A special role is played by the survey papers also presented in full. They cover a broad range of topics, including invariant subspaces, scattering theory, Wiener-Hopf equations, interpolation theorems, contraction operators, approximation in Banach spaces, etc. The papers have been classified according to subject matter into five chapters, but it needs littl...

  7. Spectroscopy of the {sup 29}Si(p,{gamma}) reaction for E{sub p}=1.00{endash}1.75 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Vavrina, G.A.; Bybee, C.R.; Mitchell, G.E.; Moore, E.F.; Shriner, J.D. [North Carolina State University, Raleigh, North Carolina 27695 (United States); Bilpuch, E.G.; Wallace, P.M.; Westerfeldt, C.R. [Duke University, Durham, North Carolina 27708 (United States); Shriner, J.F. , Jr. [Tennessee Technological University, Cookeville, Tennessee 38505 (United States)

    1997-03-01

    The {sup 29}Si(p,{gamma}) reaction has been studied in the range E{sub p}=1.00{endash}1.75 MeV. Three previously unknown states in {sup 30}P were identified, and one state previously assigned to {sup 30}P was identified as a state in {sup 14}N. Gamma-ray strengths were determined for the three new levels, and branching ratios were measured for 17 resonances. Revised J{sup {pi}};T assignments were made for nine of these states. {copyright} {ital 1997} {ital The American Physical Society}

  8. Stat1 phosphorylation determines Ras oncogenicity by regulating p27 kip1.

    Directory of Open Access Journals (Sweden)

    Shuo Wang

    Full Text Available Inactivation of p27 Kip1 is implicated in tumorigenesis and has both prognostic and treatment-predictive values for many types of human cancer. The transcription factor Stat1 is essential for innate immunity and tumor immunosurveillance through its ability to act downstream of interferons. Herein, we demonstrate that Stat1 functions as a suppressor of Ras transformation independently of an interferon response. Inhibition of Ras transformation and tumorigenesis requires the phosphorylation of Stat1 at tyrosine 701 but is independent of Stat1 phosphorylation at serine 727. Stat1 induces p27 Kip1 expression in Ras transformed cells at the transcriptional level through mechanisms that depend on Stat1 phosphorylation at tyrosine 701 and activation of Stat3. The tumor suppressor properties of Stat1 in Ras transformation are reversed by the inactivation of p27 Kip1. Our work reveals a novel functional link between Stat1 and p27 Kip1, which act in coordination to suppress the oncogenic properties of activated Ras. It also supports the notion that evaluation of Stat1 phosphorylation in human tumors may prove a reliable prognostic factor for patient outcome and a predictor of treatment response to anticancer therapies aimed at activating Stat1 and its downstream effectors.

  9. Quenching of I(2P1/2) by O3 and O(3P).

    Science.gov (United States)

    Azyazov, Valeriy N; Antonov, Ivan O; Heaven, Michael C

    2007-04-26

    Oxygen-iodine lasers that utilize electrical or microwave discharges to produce singlet oxygen are currently being developed. The discharge generators differ from conventional chemical singlet oxygen generators in that they produce significant amounts of atomic oxygen. Post-discharge chemistry includes channels that lead to the formation of ozone. Consequently, removal of I(2P1/2) by O atoms and O3 may impact the efficiency of discharge driven iodine lasers. In the present study, we have measured the rate constants for quenching of I(2P1/2) by O(3P) atoms and O3 using pulsed laser photolysis techniques. The rate constant for quenching by O3, (1.8 +/- 0.4) x 10(-12) cm3 s-1, was found to be a factor of 5 smaller than the literature value. The rate constant for quenching by O(3P) was (1.2 +/- 0.2) x 10(-11) cm3 s-1.

  10. Mechanism of Folding and Activation of Subtilisin Kexin Isozyme-1 (SKI-1)/Site-1 Protease (S1P)*

    Science.gov (United States)

    da Palma, Joel Ramos; Cendron, Laura; Seidah, Nabil Georges; Pasquato, Antonella; Kunz, Stefan

    2016-01-01

    The proprotein convertase subtilisin kexin isozyme-1 (SKI-1)/site-1 protease (S1P) is implicated in lipid homeostasis, the unfolded protein response, and lysosome biogenesis. The protease is further hijacked by highly pathogenic emerging viruses for the processing of their envelope glycoproteins. Zymogen activation of SKI-1/S1P requires removal of an N-terminal prodomain, by a multistep process, generating the mature enzyme. Here, we uncover a modular structure of the human SKI-1/S1P prodomain and define its function in folding and activation. We provide evidence that the N-terminal AB fragment of the prodomain represents an autonomous structural and functional unit that is necessary and sufficient for folding and partial activation. In contrast, the C-terminal BC fragment lacks a defined structure but is crucial for autoprocessing and full catalytic activity. Phylogenetic analysis revealed that the sequence of the AB domain is highly conserved, whereas the BC fragment shows considerable variation and seems even absent in some species. Notably, SKI-1/S1P of arthropods, like the fruit fly Drosophila melanogaster, contains a shorter prodomain comprised of full-length AB and truncated BC regions. Swapping the prodomain fragments between fly and human resulted in a fully mature and active SKI-1/S1P chimera. Our study suggests that primordial SKI-1/S1P likely contained a simpler prodomain consisting of the highly conserved AB fragment that represents an independent folding unit. The BC region appears as a later evolutionary acquisition, possibly allowing more subtle fine-tuning of the maturation process. PMID:26645686

  11. On approximation of Lie groups by discrete subgroups

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... The notion of approximation of Lie groups by discrete subgroups was introduced by Tôyama in Kodai Math. Sem. Rep. 1 (1949) 36–37 and investigated in detail by Kuranishi in Nagoya Math. J. 2 (1951) 63–71. It is known as a theorem of Tôyama that any connected Lie group approximated by discrete ...

  12. Adjoint P1 equations solution for neutron slowing down; Solucao das equacoes P1 adjuntas para moderacao de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Carlos Eduardo Santos; Martinez, Aquilino Senra; Silva, Fernando Carvalho da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    2002-07-01

    In some applications of perturbation theory, it is necessary know the adjoint neutron flux, which is obtained by the solution of adjoint neutron diffusion equation. However, the multigroup constants used for this are weighted in only the direct neutron flux, from the solution of direct P1 equations. In this work, the adjoint P1 equations are derived by the neutron transport equation, the reversion operators rules and analogies between direct and adjoint parameters. The direct and adjoint neutron fluxes resulting from the solution of P{sub 1} equations were used to three different weighting processes, to obtain the macrogroup macroscopic cross sections. It was found out noticeable differences among them. (author)

  13. Ligand binding turns moth pheromone-binding protein into a pH sensor: effect on the Antheraea polyphemus PBP1 conformation.

    Science.gov (United States)

    Katre, Uma V; Mazumder, Suman; Prusti, Rabi K; Mohanty, Smita

    2009-11-13

    In moths, pheromone-binding proteins (PBPs) are responsible for the transport of the hydrophobic pheromones to the membrane-bound receptors across the aqueous sensillar lymph. We report here that recombinant Antheraea polyphemus PBP1 (ApolPBP1) picks up hydrophobic molecule(s) endogenous to the Escherichia coli expression host that keeps the protein in the "open" (bound) conformation at high pH but switches to the "closed" (free) conformation at low pH. This finding has bearing on the solution structures of undelipidated lepidopteran moth PBPs determined thus far. Picking up a hydrophobic molecule from the host expression system could be a common feature for lipid-binding proteins. Thus, delipidation is critical for bacterially expressed lipid-binding proteins. We have shown for the first time that the delipidated ApolPBP1 exists primarily in the closed form at all pH levels. Thus, current views on the pH-induced conformational switch of PBPs hold true only for the ligand-bound open conformation of the protein. Binding of various ligands to delipidated ApolPBP1 studied by solution NMR revealed that the protein in the closed conformation switches to the open conformation only at or above pH 6.0 with a protein to ligand stoichiometry of approximately 1:1. Mutation of His(70) and His(95) to alanine drives the equilibrium toward the open conformation even at low pH for the ligand-bound protein by eliminating the histidine-dependent pH-induced conformational switch. Thus, the delipidated double mutant can bind ligand even at low pH in contrast to the wild type protein as revealed by fluorescence competitive displacement assay using 1-aminoanthracene and solution NMR.

  14. Cytoplasmic localization of Hug1p, a negative regulator of the MEC1 pathway, coincides with the compartmentalization of Rnr2p–Rnr4p

    Energy Technology Data Exchange (ETDEWEB)

    Ainsworth, William B. [Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA 70803 (United States); Hughes, Bridget Todd; Au, Wei Chun; Sakelaris, Sally [Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Kerscher, Oliver [Biology Department, The College of William and Mary, Williamsburg, VA 23185 (United States); Benton, Michael G., E-mail: benton@lsu.edu [Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA 70803 (United States); Basrai, Munira A., E-mail: basraim@mail.nih.gov [Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States)

    2013-10-04

    Highlights: •Hug1p overexpression sensitizes wild-type cells to DNA damage and hydroxyurea (HU). •Expression of Hug1p in response to HU treatment is delayed relative to Rnr3p. •MEC1 pathway genes are required for cytoplasmic localization of Hug1p. •Hug1p subcellular compartmentalization to the cytoplasm coincides with Rnr2p–Rnr4p. -- Abstract: The evolutionarily conserved MEC1 checkpoint pathway mediates cell cycle arrest and induction of genes including the RNR (Ribonucleotide reductase) genes and HUG1 (Hydroxyurea, ultraviolet, and gamma radiation) in response to DNA damage and replication arrest. Rnr complex activity is in part controlled by cytoplasmic localization of the Rnr2p–Rnr4p subunits and inactivation of negative regulators Sml1p and Dif1p upon DNA damage and hydroxyurea (HU) treatment. We previously showed that a deletion of HUG1 rescues lethality of mec1Δ and suppresses dun1Δ strains. In this study, multiple approaches demonstrate the regulatory response of Hug1p to DNA damage and HU treatment and support its role as a negative effector of the MEC1 pathway. Consistent with our hypothesis, wild-type cells are sensitive to DNA damage and HU when HUG1 is overexpressed. A Hug1 polyclonal antiserum reveals that HUG1 encodes a protein in budding yeast and its MEC1-dependent expression is delayed compared to the rapid induction of Rnr3p in response to HU treatment. Cell biology and subcellular fractionation experiments show localization of Hug1p-GFP to the cytoplasm upon HU treatment. The cytoplasmic localization of Hug1p-GFP is dependent on MEC1 pathway genes and coincides with the cytoplasmic localization of Rnr2p–Rnr4p. Taken together, the genetic interactions, gene expression, and localization studies support a novel role for Hug1p as a negative regulator of the MEC1 checkpoint response through its compartmentalization with Rnr2p–Rnr4p.

  15. Optimal random perturbations for stochastic approximation using a simultaneous perturbation gradient approximation

    DEFF Research Database (Denmark)

    Sadegh, Payman; Spall, J. C.

    1998-01-01

    simultaneous perturbation approximation to the gradient based on loss function measurements. SPSA is based on picking a simultaneous perturbation (random) vector in a Monte Carlo fashion as part of generating the approximation to the gradient. This paper derives the optimal distribution for the Monte Carlo...

  16. Fabrication of p-{beta}-Fe{sub 1{minus}x}Mn{sub x}Si{sub 2}/nSi heterostructure diode and their electrical and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Takada, T; Katsumata, H; Makita, Y; Kobayashi, N; Hasegawa, M; Uekusa, S

    1997-07-01

    The authors report on the fabrication of p-type {beta}-FeSi{sub 2} layers on n-type Si(100) substrates and the investigation of their p-n diode characteristics. Since the undoped {beta}-FeSi{sub 2} layers have typically shown n-type conductivity, the p-type layers were formed by the introduction of Mn impurity into {beta}-FeSi{sub 2} layers using two types of doping methods; one is an Electron-Beam-Deposition (EBD) procedure of Fe{sub 1{minus}x}Mn{sub x}Si{sub 2} (x < {approximately}0.1) at room temperature and subsequent annealing at 900 C for 1--120 min, where FeSi{sub 2} ingots added with Mn({approximately}10%) were used as starting materials. The other is a {sup 55}Mn{sup +}-implantation into {beta}-FeSi{sub 2} layers formed by EBD and subsequent annealing at 850 C for 1--120 min. From van der Pauw measurements, p-type {beta}-Fe{sub 1{minus}x}Mn{sub x}Si{sub 2} layers with the resistivity of 0.0036--0.031 {Omega}{center{underscore}dot}cm and hole mobility of 11.9--89.0 cm{sup 2}/V{center{underscore}dot}sec were found to be successfully formed on n-Si substrates by both doping methods. The p-n diode characteristics of these heterostructure diodes were investigated by I-V and C-V measurements. The results indicate that the carrier distribution does not agree with either ideal one-side step or one-side slop junctions, although optical transmittance and reflectance measurements indicate that the silicide/Si interface is of good quality.

  17. Bessel harmonic analysis and approximation of functions on the half-line

    International Nuclear Information System (INIS)

    Platonov, Sergei S

    2007-01-01

    We study problems of approximation of functions on [0,+∞) in the metric of L p with power weight using generalized Bessel shifts. We prove analogues of direct Jackson theorems for the modulus of smoothness of arbitrary order defined in terms of generalized Bessel shifts. We establish the equivalence of the modulus of smoothness and the K-functional. We define function spaces of Nikol'skii-Besov type and describe them in terms of best approximations. As a tool for approximation, we use a certain class of entire functions of exponential type. In this class, we prove analogues of Bernstein's inequality and others for the Bessel differential operator and its fractional powers. The main tool we use to solve these problems is Bessel harmonic analysis

  18. Alfalfa mosaic virus replicase proteins P1 and P2 interact and colocalize at the vacuolar membrane

    NARCIS (Netherlands)

    Heijden, van der M.W.; Carette, J.E.; Reinhoud, P.J.; Haegi, A.; Bol, J.F.

    2001-01-01

    Replication of Alfalfa mosaic virus (AMV) RNAs depends on the virus-encoded proteins P1 and P2. P1 contains methyltransferase- and helicase-like domains, and P2 contains a polymerase-like domain. Coimmunoprecipitation experiments revealed an interaction between in vitro translated-P1 and P2 and

  19. Telomeric 1p36.3 deletion and Ki-67 expression in B-Non-Hodgkin's Lymphoma patients associated with chronic hepatitis C virus infection.

    Science.gov (United States)

    Mosad, E; Said Abd El-Rahman Allam, M; Moustafa, H M; Mohammed, A Eliaw; El kebeer, A M; Abdel-Moneim, S S

    2014-12-01

    The hepatitis C virus (HCV) core protein is able to accumulate genetic p53 mutations and may be considered co-oncogenic. This study investigates 1p36.3 telomere deletion in B-non-Hodgkin's lymphoma (NHL) patients with chronic HCV infection using fluorescence in situ hybridization (FISH) in relation to survival to assess Ki-67 antigen expression. A study group and a control group of 100 patients with B-NHL (50 HCV positive and 50 HCV negative) and 60 control bone marrow biopsies were subjected to FISH for the detection of 1P36.3 deletion and to immunohistochemical staining with Ki-67 antigens. 1p36.3 deletion by FISH was detected in 40% of the study group, and Ki-67 was expressed in approximately 74% of patients. A significant difference was found between positive and negative HCV patients in their overall survival, the qualitative expression of Ki-67 and the quantitative detection of 1p36.3 deletion by FISH. The overall survival was shorter with the presence of an 1p36 deletion by FISH and HCV positive. We concluded that the coexistence of Ki-67 positivity, HCV positivity and 1p36.3 deletion may contribute to infection-related cancers at the 1p36.3 locus. © 2014 John Wiley & Sons Ltd.

  20. Vitamin D attenuates sphingosine-1-phosphate (S1P)-mediated inhibition of extravillous trophoblast migration.

    Science.gov (United States)

    Westwood, Melissa; Al-Saghir, Khiria; Finn-Sell, Sarah; Tan, Cherlyn; Cowley, Elizabeth; Berneau, Stéphane; Adlam, Daman; Johnstone, Edward D

    2017-12-01

    Failure of trophoblast invasion and remodelling of maternal blood vessels leads to the pregnancy complication pre-eclampsia (PE). In other systems, the sphingolipid, sphingosine-1-phosphate (S1P), controls cell migration therefore this study determined its effect on extravillous trophoblast (EVT) function. A transwell migration system was used to assess the behaviour of three trophoblast cell lines, Swan-71, SGHPL-4, and JEG3, and primary human trophoblasts in the presence or absence of S1P, S1P pathway inhibitors and 1,25(OH) 2 D 3 . QPCR and immunolocalisation were used to demonstrate EVT S1P receptor expression. EVTs express S1P receptors 1, 2 and 3. S1P inhibited EVT migration. This effect was abolished in the presence of the specific S1PR2 inhibitor, JTE-013 (p S1P alone) whereas treatment with the S1R1/3 inhibitor, FTY720, had no effect. In other cell types S1PR2 is regulated by vitamin D; here we found that treatment with 1,25(OH) 2 D 3 for 48 or 72 h reduces S1PR2 (4-fold; S1P did not inhibit the migration of cells exposed to 1,25(OH) 2 D 3 (p S1P receptor isoforms, S1P predominantly signals through S1PR2/Gα 12/13 to activate Rho and thereby acts as potent inhibitor of EVT migration. Importantly, expression of S1PR2, and therefore S1P function, can be down-regulated by vitamin D. Our data suggest that vitamin D deficiency, which is known to be associated with PE, may contribute to the impaired trophoblast migration that underlies this condition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Reduced lung lesions in pigs challenged 25 weeks after the administration of a single dose of Mycoplasma hyopneumoniae vaccine at approximately 1 week of age.

    Science.gov (United States)

    Reynolds, S C; St Aubin, L B; Sabbadini, L G; Kula, J; Vogelaar, J; Runnels, P; Peters, A R

    2009-09-01

    Two independent studies assessed the duration of immunity of an inactivated adjuvanted Mycoplasma hyopneumoniae vaccine against mycoplasmal pneumonia in seronegative (study A, n=52) and seropositive (study B, n=52) pigs. The pigs were allocated randomly to treatment and were then injected with a single dose of either the vaccine or a placebo at approximately 1 week of age. Twenty-five weeks after treatment administration, the pigs were challenged with a virulent strain (LI 36, Strain 232) of M. hyopneumoniae and the extent of lung lesions consistent with mycoplasmal pneumonia was assessed 4 weeks later. In study A, the geometric mean lung lesion score (expressed as least squares mean percentages of lung lesions) was significantly (P=0.0001) lower in vaccinated (0.3%, n=20) than in control pigs (5.9%, n=24) seronegative to M. hyopneumoniae at enrolment; similarly, in study B, the extent of lung lesions was significantly reduced (P=0.0385) in seropositive vaccinated pigs (2.0%, n=22) compared to controls (4.5%, n=26). At the end of the investigation period, 4 weeks after challenge, mean antibody sample-to-positive (S/P) ratios were significantly higher both in seronegative (P=0.0012) and seropositive (P=0.0001) vaccinated pigs (mean values=0.77 and 0.81, respectively) than in controls (mean values=0.51 and 0.38, respectively).

  2. p53 functional impairment and high p21waf1/cip1 expression in human T-cell lymphotropic/leukemia virus type I-transformed T cells.

    Science.gov (United States)

    Cereseto, A; Diella, F; Mulloy, J C; Cara, A; Michieli, P; Grassmann, R; Franchini, G; Klotman, M E

    1996-09-01

    Human T-cell lymphotropic/leukemia virus type I (HTLV-I) is associated with T-cell transformation both in vivo and in vitro. Although some of the mechanisms responsible for transformation remain unknown, increasing evidence supports a direct role of viral as well as dysregulated cellular proteins in transformation. We investigated the potential role of the tumor suppressor gene p53 and of the p53-regulated gene, p21waf1/cip1 (wild-type p53 activated fragment 1/cycling dependent kinases [cdks] interacting protein 1), in HTLV-I-infected T cells. We have found that the majority of HTLV-I-infected T cells have the wild-type p53 gene. However, its function in HTLV-I-transformed cells appears to be impaired, as shown by the lack of appropriate p53-mediated responses to ionizing radiation (IR). Interestingly, the expression of the p53 inducible gene, p21waf1/cip1, is elevated at the messenger ribonucleic acid and protein levels in all HTLV-I-infected T-cell lines examined as well as in Taxl-1, a human T-cell line stably expressing Tax. Additionally, Tax induces upregulation of a p21waf1/cip1 promoter-driven luciferase gene in p53 null cells, and increases p21waf1/cip1 expression in Jurkat T cells. These findings suggest that the Tax protein is at least partially responsible for the p53-independent expression of p21waf1/cip1 in HTLV-I-infected cells. Dysregulation of p53 and p21waf1/cip1 proteins regulating cell-cycle progression, may represent an important step in HTLV-I-induced T-cell transformation.

  3. Cyclic approximation to stasis

    Directory of Open Access Journals (Sweden)

    Stewart D. Johnson

    2009-06-01

    Full Text Available Neighborhoods of points in $mathbb{R}^n$ where a positive linear combination of $C^1$ vector fields sum to zero contain, generically, cyclic trajectories that switch between the vector fields. Such points are called stasis points, and the approximating switching cycle can be chosen so that the timing of the switches exactly matches the positive linear weighting. In the case of two vector fields, the stasis points form one-dimensional $C^1$ manifolds containing nearby families of two-cycles. The generic case of two flows in $mathbb{R}^3$ can be diffeomorphed to a standard form with cubic curves as trajectories.

  4. Approximate cohomology in Banach algebras | Pourabbas ...

    African Journals Online (AJOL)

    We introduce the notions of approximate cohomology and approximate homotopy in Banach algebras and we study the relation between them. We show that the approximate homotopically equivalent cochain complexes give the same approximate cohomologies. As a special case, approximate Hochschild cohomology is ...

  5. Iterative Multiparameter Elastic Waveform Inversion Using Prestack Time Imaging and Kirchhoff approximation

    Science.gov (United States)

    Khaniani, Hassan

    boundary condition of the wave equation is set up along reflection surfaces. Hence, the surface integral Kirchhoff approximation is used as a mathematical framework instead of the volume integral of the Born approximation. In addition, I study the feasibility of iterative coupling of ray theory with the Kirchhoff approximation for inversion. For the amplitude considerations, the direct relationship between the scattering potential of the Born approximation with the reflectivity function of the asymptotic Kirchhoff approximation for elastic waves is used. Therefore, I use the linearized Zoeppritz approximation of Aki and Richards (1980) for computation of the forward modeling and migration operators as well as gradient function from Amplitude vs Offset (AVO) inversion. The multiparameter elastic inversion approach is applicable to all types of reflected wavefields such as P-to-P, P-to-S, S-to-S and S-to-P. Traveltime estimation of forward modeling and migration/inversion operators are based on the DSR equation. All operators involved in inversion, including the background model for DSR and AVO are updated at each iteration. The migration/inversion procedure maps the mode converted waves to the traveltime of incident waves which fixes the registration problem of events that travel from source to scatter point. The inversion of the reflected P-to-P and P-to-S synthetic and field data are provided for the numerical examples. This approach is applicable for complex structures however, to estimate the traveltime of scatterpoints, ray tracing can be added to the algorithm. For such a medium, the scatterpoint traveltime approximations from the PSTM, is compared to the PSDM approach using numerical analysis of ray- and FDTD-based modeling. In part of this thesis, I further improve the conventional velocity analysis of Common Scatter Point (CSP) gathers by including the tilt effects. I show that travel time response of scatter points beneath a dipping interface experiences an

  6. Approximate first integrals of a chaotic Hamiltonian system | Unal ...

    African Journals Online (AJOL)

    Approximate first integrals (conserved quantities) of a Hamiltonian dynamical system with two-degrees of freedom which arises in the modeling of galaxy have been obtained based on the approximate Noether symmetries for the resonance ω1 = ω2. Furthermore, Kolmogorov-Arnold-Moser (KAM) curves have been ...

  7. 36 CFR 254.11 - Exchanges at approximately equal value.

    Science.gov (United States)

    2010-07-01

    ... equal value. 254.11 Section 254.11 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LANDOWNERSHIP ADJUSTMENTS Land Exchanges § 254.11 Exchanges at approximately equal value. (a) The authorized officer may exchange lands which are of approximately equal value upon a determination that: (1...

  8. Spitzer Evidence for a Late Heavy Bombardment and the Formation of Urelites in {eta}Corvi at Approximately 1 Gyr

    Science.gov (United States)

    Lisse, C. M.; Wyatt, M. C.; Chen, C. H.; Morlok, A.; Watson, D. M.; Manj, P.; Sheehan, P.; Currie, T. M.; Thebault, P.; Sitko, M. L.

    2011-01-01

    We have analyzed Spitzer and NASA/IRTF 2 - 35 micrometer spectra of the warm, 350 K circumstellar dust around the nearby MS star eta Corvi (F2V, 1.4 plus or minus 0.3 Gyr). The spectra show clear evidence for warm, water- and carbon-rich dust at 3 AU from the central star, in the system's Terrestrial Habitability Zone. Spectral features due to ultra-primitive cometary material were found, in addition to features due to impact produced silica and high temperature carbonaceous phases. At least 9 x 10(exp 18) kg of 0.1 - 100 micrometer warm dust is present in a collisional equilibrium distribution with dn/da a(exp -3.5), the equivalent of a 130 km radius KBO of 1.0 grams per cubic centimeter density and similar to recent estimates of the mass delivered to the Earth at 0.6 - 0.8 Gyr during the Late Heavy Bombardment. We conclude that the parent body was a Kuiper-Belt body or bodies which captured a large amount of early primitive material in the first Myrs of the system's lifetime and preserved it in deep freeze at approximately 150 AU. At approximately 1.4 Gyr they were prompted by dynamical stirring of their parent Kuiper Belt into spiraling into the inner system, eventually colliding at 5-10 kilometers per second with a rocky planetary body of mass less than or equal to M(sub Earth at approximately 3 AU, delivering large amounts of water (greater than 0.1 % of M(sub Earth's Oceans)) and carbon-rich material. The Spitzer spectrum also closely matches spectra reported for the Ureilite meteorites of the Sudan Almahata Sitta fall in 2008, suggesting that one of the Ureilite parent bodies was a KBO.

  9. International Conference Approximation Theory XIV

    CERN Document Server

    Schumaker, Larry

    2014-01-01

    This volume developed from papers presented at the international conference Approximation Theory XIV,  held April 7–10, 2013 in San Antonio, Texas. The proceedings contains surveys by invited speakers, covering topics such as splines on non-tensor-product meshes, Wachspress and mean value coordinates, curvelets and shearlets, barycentric interpolation, and polynomial approximation on spheres and balls. Other contributed papers address a variety of current topics in approximation theory, including eigenvalue sequences of positive integral operators, image registration, and support vector machines. This book will be of interest to mathematicians, engineers, and computer scientists working in approximation theory, computer-aided geometric design, numerical analysis, and related approximation areas.

  10. Mechanism of Folding and Activation of Subtilisin Kexin Isozyme-1 (SKI-1)/Site-1 Protease (S1P).

    Science.gov (United States)

    da Palma, Joel Ramos; Cendron, Laura; Seidah, Nabil Georges; Pasquato, Antonella; Kunz, Stefan

    2016-01-29

    The proprotein convertase subtilisin kexin isozyme-1 (SKI-1)/site-1 protease (S1P) is implicated in lipid homeostasis, the unfolded protein response, and lysosome biogenesis. The protease is further hijacked by highly pathogenic emerging viruses for the processing of their envelope glycoproteins. Zymogen activation of SKI-1/S1P requires removal of an N-terminal prodomain, by a multistep process, generating the mature enzyme. Here, we uncover a modular structure of the human SKI-1/S1P prodomain and define its function in folding and activation. We provide evidence that the N-terminal AB fragment of the prodomain represents an autonomous structural and functional unit that is necessary and sufficient for folding and partial activation. In contrast, the C-terminal BC fragment lacks a defined structure but is crucial for autoprocessing and full catalytic activity. Phylogenetic analysis revealed that the sequence of the AB domain is highly conserved, whereas the BC fragment shows considerable variation and seems even absent in some species. Notably, SKI-1/S1P of arthropods, like the fruit fly Drosophila melanogaster, contains a shorter prodomain comprised of full-length AB and truncated BC regions. Swapping the prodomain fragments between fly and human resulted in a fully mature and active SKI-1/S1P chimera. Our study suggests that primordial SKI-1/S1P likely contained a simpler prodomain consisting of the highly conserved AB fragment that represents an independent folding unit. The BC region appears as a later evolutionary acquisition, possibly allowing more subtle fine-tuning of the maturation process. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. APPECT: An Approximate Backbone-Based Clustering Algorithm for Tags

    DEFF Research Database (Denmark)

    Zong, Yu; Xu, Guandong; Jin, Pin

    2011-01-01

    algorithm for Tags (APPECT). The main steps of APPECT are: (1) we execute the K-means algorithm on a tag similarity matrix for M times and collect a set of tag clustering results Z={C1,C2,…,Cm}; (2) we form the approximate backbone of Z by executing a greedy search; (3) we fix the approximate backbone...... as the initial tag clustering result and then assign the rest tags into the corresponding clusters based on the similarity. Experimental results on three real world datasets namely MedWorm, MovieLens and Dmoz demonstrate the effectiveness and the superiority of the proposed method against the traditional...... Agglomerative Clustering on tagging data, which possess the inherent drawbacks, such as the sensitivity of initialization. In this paper, we instead make use of the approximate backbone of tag clustering results to find out better tag clusters. In particular, we propose an APProximate backbonE-based Clustering...

  12. Forms of Approximate Radiation Transport

    CERN Document Server

    Brunner, G

    2002-01-01

    Photon radiation transport is described by the Boltzmann equation. Because this equation is difficult to solve, many different approximate forms have been implemented in computer codes. Several of the most common approximations are reviewed, and test problems illustrate the characteristics of each of the approximations. This document is designed as a tutorial so that code users can make an educated choice about which form of approximate radiation transport to use for their particular simulation.

  13. Approximate and renormgroup symmetries

    International Nuclear Information System (INIS)

    Ibragimov, Nail H.; Kovalev, Vladimir F.

    2009-01-01

    ''Approximate and Renormgroup Symmetries'' deals with approximate transformation groups, symmetries of integro-differential equations and renormgroup symmetries. It includes a concise and self-contained introduction to basic concepts and methods of Lie group analysis, and provides an easy-to-follow introduction to the theory of approximate transformation groups and symmetries of integro-differential equations. The book is designed for specialists in nonlinear physics - mathematicians and non-mathematicians - interested in methods of applied group analysis for investigating nonlinear problems in physical science and engineering. (orig.)

  14. Spin-1/2 particles in non-inertial reference frames. Low- and high-energy approximations

    International Nuclear Information System (INIS)

    Singh, D.; Papini, G.

    2000-01-01

    Spin-1/2 particles can be used to study inertial and gravitational effects by means of interferometers, particle accelerators, and ultimately quantum systems. These studies require, in general, knowledge of the Hamiltonian and of the inertial and gravitational quantum phases. The procedure followed gives both in the low- and high-energy approximations. The latter affords a more consistent treatment of mass at high energies. The procedure is based on general relativity and on a solution of the Dirac equation that is exact to first-order in the metric deviation. Several previously known acceleration- and rotation-induced effects are rederived in a comprehensive, unified way. Several new effects involve spin, electromagnetic and inertial/gravitational fields in different combinations

  15. Only Acyl Carrier Protein 1 (AcpP1 Functions in Pseudomonas aeruginosa Fatty Acid Synthesis

    Directory of Open Access Journals (Sweden)

    Jin-Cheng Ma

    2017-11-01

    Full Text Available The genome of Pseudomonas aeruginosa contains three open reading frames, PA2966, PA1869, and PA3334, which encode putative acyl carrier proteins, AcpP1, AcpP2, and AcpP3, respectively. In this study, we found that, although these apo-ACPs were successfully phosphopantetheinylated by P. aeruginosa phosphopantetheinyl transferase (PcpS and all holo-forms of these proteins could be acylated by Vibrio harveyi acyl-ACP synthetase (AasS, only AcpP1 could be used as a substrate for the synthesis of fatty acids, catalyzed by P. aeruginosa cell free extracts in vitro, and only acpP1 gene could restore growth in the Escherichia coliacpP mutant strain CY1877. And P. aeruginosaacpP1 could not be deleted, while disruption of acpP2 or acpP3 in the P. aeruginosa genome allowed mutant strains to grow as well as the wild type strain. These findings confirmed that only P. aeruginosa AcpP1 functions in fatty acid biosynthesis, and that acpP2 and acpP3 do not play roles in the fatty acid synthetic pathway. Moreover, disruption of acpP2 and acpP3 did not affect the ability of P. aeruginosa to produce N-acylhomoserine lactones (AHL, but replacement of P. aeruginosaacpP1 with E. coliacpP caused P. aeruginosa to reduce the production of AHL molecules, which indicated that neither P. aeruginosa AcpP2 nor AcpP3 can act as a substrate for synthesis of AHL molecules in vivo. Furthermore, replacement of acpP1 with E. coliacpP reduced the ability of P. aeruginosa to produce some exo-products and abolished swarming motility in P. aeruginosa.

  16. Anomalous behaviour of the magnetic susceptibility of the mixed spin-1 and spin- 1/2 anisotropic Heisenberg model in the Oguchi approximation

    International Nuclear Information System (INIS)

    Bobak, Andrej; Dely, Jan; Pokorny, Vladislav

    2010-01-01

    The effects of both an exchange anisotropy and a single-ion anisotropy on the magnetic susceptibility of the mixed spin-1 and spin- 1/2 Heisenberg model are investigated by the use of an Oguchi approximation. Particular emphasis is given to the simple cubic lattice with coordination number z = 6 for which the magnetic susceptibility is determined numerically. Anomalous behaviour in the thermal variation of the magnetic susceptibility in the low-temperature region is found due to the applied negative single-ion anisotropy field strength. Also, the difference between the behaviours of the magnetic susceptibility of the Heisenberg and Ising models is discussed.

  17. APPROXIMATION OF PROBABILITY DISTRIBUTIONS IN QUEUEING MODELS

    Directory of Open Access Journals (Sweden)

    T. I. Aliev

    2013-03-01

    Full Text Available For probability distributions with variation coefficient, not equal to unity, mathematical dependences for approximating distributions on the basis of first two moments are derived by making use of multi exponential distributions. It is proposed to approximate distributions with coefficient of variation less than unity by using hypoexponential distribution, which makes it possible to generate random variables with coefficient of variation, taking any value in a range (0; 1, as opposed to Erlang distribution, having only discrete values of coefficient of variation.

  18. Beyond the random phase approximation

    DEFF Research Database (Denmark)

    Olsen, Thomas; Thygesen, Kristian S.

    2013-01-01

    We assess the performance of a recently proposed renormalized adiabatic local density approximation (rALDA) for ab initio calculations of electronic correlation energies in solids and molecules. The method is an extension of the random phase approximation (RPA) derived from time-dependent density...... functional theory and the adiabatic connection fluctuation-dissipation theorem and contains no fitted parameters. The new kernel is shown to preserve the accurate description of dispersive interactions from RPA while significantly improving the description of short-range correlation in molecules, insulators......, and metals. For molecular atomization energies, the rALDA is a factor of 7 better than RPA and a factor of 4 better than the Perdew-Burke-Ernzerhof (PBE) functional when compared to experiments, and a factor of 3 (1.5) better than RPA (PBE) for cohesive energies of solids. For transition metals...

  19. Search for narrow p states in the reaction pi /sup -/p to p pi /sup - /pp at 16 GeV/c

    CERN Document Server

    Chung, S U; Bensinger, J; Button-Shafer, J; Dhar, S; Dowd, J; Etkin, A; Fernow, R; Foley, K; Goldman, J H; Kern, W; Kirk, H; Kopp, J; Kramer, M A; Lesnik, A; Lichti, R; Lindenbaum, S J; Love, W; Mallik, U; Morris, T; Morris, W; Ozaki, S; Platner, E; Protopopescu, S D; Saulys, A; Weygand, D P; Wheeler, C D; Willen, E; Winik, M

    1981-01-01

    The authors have carried out a sensitive (>or approximately=5 events /nb) search for narrow pp states at the BNL Multiparticle Spectrometer. They found no evidence of narrow pp states at 2020 and 2200 MeV in the reaction pi /sup -/p to p pi /sup -/pp at 16 GeV/c. The authors quote 2 sigma upper limits of or approximately=5 sigma signals at 2020 and 2200 MeV. (5 refs).

  20. Shaping the landscape: Metabolic regulation of S1P gradients

    Science.gov (United States)

    Olivera, Ana; Allende, Maria Laura; Proia, Richard L.

    2012-01-01

    Sphingosine-1-phosphate (S1P) is a lipid that functions as a metabolic intermediate and a cellular signaling molecule. These roles are integrated when compartments with differing extracellular S1P concentrations are formed that serve to regulate functions within the immune and vascular systems, as well as during pathologic conditions. Gradients of S1P concentration are achieved by the organization of cells with specialized expression of S1P metabolic pathways within tissues. S1P concentration gradients underpin the ability of S1P signaling to regulate in vivo physiology. This review will discuss the mechanisms that are necessary for the formation and maintenance of S1P gradients, with the aim of understanding how a simple lipid controls complex physiology. PMID:22735358

  1. Improved wavelengths for the 1s2s3S1-1s2p3P0,2 transitions in helium-like Si12+

    International Nuclear Information System (INIS)

    Armour, I.A.; Myers, E.G.; Silver, J.D.; Traebert, E.; Oxford Univ.

    1979-01-01

    The wavelengths of the 1s2s 3 S 1 -1s2p 3 P 0 , 2 transitions in He-like Si 12+ have been remaesured to be 87.86 +- 0.01 nm and 81.48 +- 0.01 nm. The use of Rydberg lines for the calibration of fast beam spectra is discussed. (orig.)

  2. Determination of the 1s2{\\ell }2{{\\ell }}^{\\prime } state production ratios {{}^{4}P}^{o}/{}^{2}P, {}^{2}D/{}^{2}P and {{}^{2}P}_{+}/{{}^{2}P}_{-} from fast (1{s}^{2},1s2s\\,{}^{3}S) mixed-state He-like ion beams in collisions with H2 targets

    Science.gov (United States)

    Benis, E. P.; Zouros, T. J. M.

    2016-12-01

    New results are presented on the ratio {R}m={σ }{T2p}( {}4P)/{σ }{T2p}({}2P) concerning the production cross sections of Li-like 1s2s2p quartet and doublet P states formed in energetic ion-atom collisions by single 2p electron transfer to the metastable 1s2s {}3S component of the He-like ion beam. Spin statistics predict a value of R m = 2 independent of the collision system in disagreement with most reported measurements of {R}m≃ 1{--}9. A new experimental approach is presented for the evaluation of R m having some practical advantages over earlier approaches. It also allows for the determination of the separate contributions of ground- and metastable-state beam components to the measured spectra. Applying our technique to zero-degree Auger projectile spectra from 4.5 MeV {{{B}}}3+ (Benis et al 2002 Phys. Rev. A 65 064701) and 25.3 MeV {{{F}}}7+ (Zamkov et al 2002 Phys. Rev. A 65 062706) mixed state (1{s}2 {}1S,1s2s {}3S) He-like ion collisions with H2 targets, we report new values of {R}m=3.5+/- 0.4 for boron and {R}m=1.8+/- 0.3 for fluorine. In addition, the ratios of {}2D/{}2P and {{}2P}+/{{}2P}- populations from either the metastable and/or ground state beam component, also relevant to this analysis, are evaluated and compared to previously reported results for carbon collisions on helium (Strohschein et al 2008 Phys. Rev. A 77 022706) including a critical comparison to theory.

  3. Magnetic reconnection under anisotropic magnetohydrodynamic approximation

    International Nuclear Information System (INIS)

    Hirabayashi, K.; Hoshino, M.

    2013-01-01

    We study the formation of slow-mode shocks in collisionless magnetic reconnection by using one- and two-dimensional collisionless MHD codes based on the double adiabatic approximation and the Landau closure model. We bridge the gap between the Petschek-type MHD reconnection model accompanied by a pair of slow shocks and the observational evidence of the rare occasion of in-situ slow shock observations. Our results showed that once magnetic reconnection takes place, a firehose-sense (p ∥ >p ⊥ ) pressure anisotropy arises in the downstream region, and the generated slow shocks are quite weak comparing with those in an isotropic MHD. In spite of the weakness of the shocks, however, the resultant reconnection rate is 10%–30% higher than that in an isotropic case. This result implies that the slow shock does not necessarily play an important role in the energy conversion in the reconnection system and is consistent with the satellite observation in the Earth's magnetosphere

  4. Approximations of Fuzzy Systems

    Directory of Open Access Journals (Sweden)

    Vinai K. Singh

    2013-03-01

    Full Text Available A fuzzy system can uniformly approximate any real continuous function on a compact domain to any degree of accuracy. Such results can be viewed as an existence of optimal fuzzy systems. Li-Xin Wang discussed a similar problem using Gaussian membership function and Stone-Weierstrass Theorem. He established that fuzzy systems, with product inference, centroid defuzzification and Gaussian functions are capable of approximating any real continuous function on a compact set to arbitrary accuracy. In this paper we study a similar approximation problem by using exponential membership functions

  5. Approximate and renormgroup symmetries

    Energy Technology Data Exchange (ETDEWEB)

    Ibragimov, Nail H. [Blekinge Institute of Technology, Karlskrona (Sweden). Dept. of Mathematics Science; Kovalev, Vladimir F. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Mathematical Modeling

    2009-07-01

    ''Approximate and Renormgroup Symmetries'' deals with approximate transformation groups, symmetries of integro-differential equations and renormgroup symmetries. It includes a concise and self-contained introduction to basic concepts and methods of Lie group analysis, and provides an easy-to-follow introduction to the theory of approximate transformation groups and symmetries of integro-differential equations. The book is designed for specialists in nonlinear physics - mathematicians and non-mathematicians - interested in methods of applied group analysis for investigating nonlinear problems in physical science and engineering. (orig.)

  6. (p,q)-Generalization of Szász-Mirakyan operators

    Science.gov (United States)

    Acar, Tuncer

    2016-07-01

    In this paper, we introduce new modifications of Szasz-Mirakyan operators based on (p,q)-integers. We first give a recurrence relation for the moments of new operators and present explicit formula for the moments and central moments up to order 4. Some approximation properties of new operators are explored: the uniform convergence over bounded and unbounded intervals is established, direct approximation properties of the operators in terms of the moduli of smoothness is obtained and Voronovskaya theorem is presented. For the particular case p=1, the previous results for q-Szasz-Mirakyan operators are captured.

  7. HEXIM1, a New Player in the p53 Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Lew, Qiao Jing; Chu, Kai Ling; Chia, Yi Ling; Cheong, Nge [Expression Engineering Group, Bioprocessing Technology Institute, A*STAR (Agency for Science, Technology and Research), 20 Biopolis Way, #06-01, Singapore 138668 (Singapore); Chao, Sheng-Hao, E-mail: jimmy_chao@bti.a-star.edu.sg [Expression Engineering Group, Bioprocessing Technology Institute, A*STAR (Agency for Science, Technology and Research), 20 Biopolis Way, #06-01, Singapore 138668 (Singapore); Department of Microbiology, National University of Singapore, Singapore 117597 (Singapore)

    2013-07-04

    Hexamethylene bisacetamide-inducible protein 1 (HEXIM1) is best known as the inhibitor of positive transcription elongation factor b (P-TEFb), which controls transcription elongation of RNA polymerase II and Tat transactivation of human immunodeficiency virus. Besides P-TEFb, several proteins have been identified as HEXIM1 binding proteins. It is noteworthy that more than half of the HEXIM1 binding partners are involved in cancers. P53 and two key regulators of the p53 pathway, nucleophosmin (NPM) and human double minute-2 protein (HDM2), are among the factors identified. This review will focus on the functional importance of the interactions between HEXIM1 and p53/NPM/HDM2. NPM and the cytoplasmic mutant of NPM, NPMc+, were found to regulate P-TEFb activity and RNA polymerase II transcription through the interaction with HEXIM1. Importantly, more than one-third of acute myeloid leukemia (AML) patients carry NPMc+, suggesting the involvement of HEXIM1 in tumorigenesis of AML. HDM2 was found to ubiquitinate HEXIM1. The HDM2-mediated ubiquitination of HEXIM1 did not lead to protein degradation of HEXIM1 but enhanced its inhibitory activity on P-TEFb. Recently, HEXIM1 was identified as a novel positive regulator of p53. HEXIM1 prevented p53 ubiquitination by competing with HDM2 in binding to p53. Taken together, the new evidence suggests a role of HEXIM1 in regulating the p53 pathway and tumorigenesis.

  8. Lindhard's polarization parameter and atomic sum rules in the local plasma approximation

    DEFF Research Database (Denmark)

    Cabrera-Trujillo, R.; Apell, P.; Oddershede, J.

    2017-01-01

    In this work, we analyze the effects of Lindhard polarization parameter, χ, on the sum rule, Sp, within the local plasma approximation (LPA) as well as on the logarithmic sum rule Lp = dSp/dp, in both cases for the system in an initial excited state. We show results for a hydrogenic atom with nuc......In this work, we analyze the effects of Lindhard polarization parameter, χ, on the sum rule, Sp, within the local plasma approximation (LPA) as well as on the logarithmic sum rule Lp = dSp/dp, in both cases for the system in an initial excited state. We show results for a hydrogenic atom...... in terms of a screened charge Z* for the ground state. Our study shows that by increasing χ, the sum rule for p0 it increases, and the value p=0 provides the normalization/closure relation which remains fixed to the number of electrons for the same initial state. When p is fixed...

  9. Collisions of halogen (2P) and rare gas (1S) atoms

    International Nuclear Information System (INIS)

    Becker, C.H.

    1978-12-01

    Differential cross sections I (THETA) at several collision energies measured in crossed molecular beam experiments are reported for several combinations of halogen atoms ( 2 P) scattered off rare gas-rare gas atoms ( 1 S 0 ), namely, F + Ne, F + Ar, F + Kr, F + Xe, C1 + Xe. The scattering is described by an elastic model appropriate to Hund's case c coupling. With the use of this model, the X 1/2, I 3/2, and II 1/2 interaction potential energy curves are derived by fitting calculated differential cross sections, based on analytic representations of the potentials, to the data. The F - Xe X 1/2 potential shows a significant bonding qualitatively different than for the other F-rare gases. The I 3/2 and II 1/2 potentials closely resemble the van der Waals interactions of the one electron richer ground state rare gas-rare gas systems. Coupled-channel scattering calculations are carried out for F + Ar, F + Xe, and C1 + Xe using the realistic potential curves derived earlier. The results justify the use of the elastic model, and give additional information on intramultiplet and intermultiplet transitions. The transitions are found to be governed by the crossing of the two Ω = 1/2 potentials in the complex plane. The measured I (theta) and I (THETA) derived from the coupled-channel computations show small oscillations or perturbations (Stueckelberg oscillations) though quantitative agreement is not obtained.The nature of the anomalous F - Xe X 1/2 potential is discussed as is the approximation of a constant spin orbit coupling over the experimentally accessible range of internuclear distances for these open shell molecules. 55 references

  10. Microglia P2Y13 Receptors Prevent Astrocyte Proliferation Mediated by P2Y1 Receptors

    Directory of Open Access Journals (Sweden)

    Clara Quintas

    2018-05-01

    Full Text Available Cerebral inflammation is a common feature of several neurodegenerative diseases that requires a fine interplay between astrocytes and microglia to acquire appropriate phenotypes for an efficient response to neuronal damage. During brain inflammation, ATP is massively released into the extracellular medium and converted into ADP. Both nucleotides acting on P2 receptors, modulate astrogliosis through mechanisms involving microglia-astrocytes communication. In previous studies, primary cultures of astrocytes and co-cultures of astrocytes and microglia were used to investigate the influence of microglia on astroglial proliferation induced by ADPβS, a stable ADP analog. In astrocyte cultures, ADPβS increased cell proliferation through activation of P2Y1 and P2Y12 receptors, an effect abolished in co-cultures (of astrocytes with ∼12.5% microglia. The possibility that the loss of the ADPβS-mediated effect could have been caused by a microglia-induced degradation of ADPβS or by a preferential microglial localization of P2Y1 or P2Y12 receptors was excluded. Since ADPβS also activates P2Y13 receptors, the contribution of microglial P2Y13 receptors to prevent the proliferative effect of ADPβS in co-cultures was investigated. The results obtained indicate that P2Y13 receptors are low expressed in astrocytes and mainly expressed in microglia. Furthermore, in co-cultures, ADPβS induced astroglial proliferation in the presence of the selective P2Y13 antagonist MRS 2211 (3 μM and of the selective P2Y12 antagonist AR-C66096 (0.1 μM, suggesting that activation of microglial P2Y12 and P2Y13 receptors may induce the release of messengers that inhibit astroglial proliferation mediated by P2Y1,12 receptors. In this microglia-astrocyte paracrine communication, P2Y12 receptors exert opposite effects in astroglial proliferation as a result of its cellular localization: cooperating in astrocytes with P2Y1 receptors to directly stimulate proliferation and in

  11. Iterative approximation of the solution of a monotone operator equation in certain Banach spaces

    International Nuclear Information System (INIS)

    Chidume, C.E.

    1988-01-01

    Let X=L p (or l p ), p ≥ 2. The solution of the equation Ax=f, f is an element of X is approximated in X by an iteration process in each of the following two cases: (i) A is a bounded linear mapping of X into itself which is also bounded below; and, (ii) A is a nonlinear Lipschitz mapping of X into itself and satisfies ≥ m |x-y| 2 , for some constant m > 0 and for all x, y in X, where j is the single-valued normalized duality mapping of X into X* (the dual space of X). A related result deals with the iterative approximation of the fixed point of a Lipschitz strictly pseudocontractive mapping in X. (author). 12 refs

  12. Cosmological applications of Padé approximant

    International Nuclear Information System (INIS)

    Wei, Hao; Yan, Xiao-Peng; Zhou, Ya-Nan

    2014-01-01

    As is well known, in mathematics, any function could be approximated by the Padé approximant. The Padé approximant is the best approximation of a function by a rational function of given order. In fact, the Padé approximant often gives better approximation of the function than truncating its Taylor series, and it may still work where the Taylor series does not converge. In the present work, we consider the Padé approximant in two issues. First, we obtain the analytical approximation of the luminosity distance for the flat XCDM model, and find that the relative error is fairly small. Second, we propose several parameterizations for the equation-of-state parameter (EoS) of dark energy based on the Padé approximant. They are well motivated from the mathematical and physical points of view. We confront these EoS parameterizations with the latest observational data, and find that they can work well. In these practices, we show that the Padé approximant could be an useful tool in cosmology, and it deserves further investigation

  13. Cosmological applications of Padé approximant

    Science.gov (United States)

    Wei, Hao; Yan, Xiao-Peng; Zhou, Ya-Nan

    2014-01-01

    As is well known, in mathematics, any function could be approximated by the Padé approximant. The Padé approximant is the best approximation of a function by a rational function of given order. In fact, the Padé approximant often gives better approximation of the function than truncating its Taylor series, and it may still work where the Taylor series does not converge. In the present work, we consider the Padé approximant in two issues. First, we obtain the analytical approximation of the luminosity distance for the flat XCDM model, and find that the relative error is fairly small. Second, we propose several parameterizations for the equation-of-state parameter (EoS) of dark energy based on the Padé approximant. They are well motivated from the mathematical and physical points of view. We confront these EoS parameterizations with the latest observational data, and find that they can work well. In these practices, we show that the Padé approximant could be an useful tool in cosmology, and it deserves further investigation.

  14. A New Approach to Rational Discrete-Time Approximations to Continuous-Time Fractional-Order Systems

    OpenAIRE

    Matos , Carlos; Ortigueira , Manuel ,

    2012-01-01

    Part 10: Signal Processing; International audience; In this paper a new approach to rational discrete-time approximations to continuous fractional-order systems of the form 1/(sα+p) is proposed. We will show that such fractional-order LTI system can be decomposed into sub-systems. One has the classic behavior and the other is similar to a Finite Impulse Response (FIR) system. The conversion from continuous-time to discrete-time systems will be done using the Laplace transform inversion integr...

  15. HDL activation of endothelial sphingosine-1-phosphate receptor-1 (S1P1) promotes regeneration and suppresses fibrosis in the liver.

    Science.gov (United States)

    Ding, Bi-Sen; Liu, Catherine H; Sun, Yue; Chen, Yutian; Swendeman, Steven L; Jung, Bongnam; Chavez, Deebly; Cao, Zhongwei; Christoffersen, Christina; Nielsen, Lars Bo; Schwab, Susan R; Rafii, Shahin; Hla, Timothy

    2016-12-22

    Regeneration of hepatic sinusoidal vasculature is essential for non-fibrotic liver regrowth and restoration of its metabolic capacity. However, little is known about how this specialized vascular niche is regenerated. Here we show that activation of endothelial sphingosine-1-phosphate receptor-1 (S1P 1 ) by its natural ligand bound to HDL (HDL-S1P) induces liver regeneration and curtails fibrosis. In mice lacking HDL-S1P, liver regeneration after partial hepatectomy was impeded and associated with aberrant vascular remodeling, thrombosis and peri-sinusoidal fibrosis. Notably, this "maladaptive repair" phenotype was recapitulated in mice that lack S1P 1 in the endothelium. Reciprocally, enhanced plasma levels of HDL-S1P or administration of SEW2871, a pharmacological agonist specific for S1P 1 enhanced regeneration of metabolically functional vasculature and alleviated fibrosis in mouse chronic injury and cholestasis models. This study shows that natural and pharmacological ligands modulate endothelial S1P 1 to stimulate liver regeneration and inhibit fibrosis, suggesting that activation of this pathway may be a novel therapeutic strategy for liver fibrosis.

  16. Marginalized approximate filtering of state-space models

    Czech Academy of Sciences Publication Activity Database

    Dedecius, Kamil

    2018-01-01

    Roč. 32, č. 1 (2018), s. 1-12 ISSN 0890-6327 R&D Projects: GA ČR(CZ) GA16-09848S Institutional support: RVO:67985556 Keywords : approximate filtering * marginalized filters * particle filtering Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 1.708, year: 2016 http://library.utia.cas.cz/separaty/2017/AS/dedecius-0478074.pdf

  17. Towards Comprehension of the ABCB1/P-Glycoprotein Role in Chronic Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Raquel C. Maia

    2018-01-01

    Full Text Available Abstract: The introduction of imatinib (IM, a BCR-ABL1 tyrosine kinase inhibitor (TKI, has represented a significant advance in the first-line treatment of chronic myeloid leukemia (CML. However, approximately 30% of patients need to discontinue IM due to resistance or intolerance to this drug. Both resistance and intolerance have also been observed in treatment with the second-generation TKIs—dasatinib, nilotinib, and bosutinib—and the third-generation TKI—ponatinib. The mechanisms of resistance to TKIs may be BCR-ABL1-dependent and/or BCR-ABL1-independent. Although the role of efflux pump P-glycoprotein (Pgp, codified by the ABCB1 gene, is unquestionable in drug resistance of many neoplasms, a longstanding question exists about whether Pgp has a firm implication in TKI resistance in the clinical scenario. The goal of this review is to offer an overview of ABCB1/Pgp expression/activity/polymorphisms in CML. Understanding how interactions, associations, or cooperation between Pgp and other molecules—such as inhibitor apoptosis proteins, microRNAs, or microvesicles—impact IM resistance risk may be critical in evaluating the response to TKIs in CML patients. In addition, new non-TKI compounds may be necessary in order to overcome the resistance mediated by Pgp in CML.

  18. Metformin and Resveratrol Inhibited High Glucose-Induced Metabolic Memory of Endothelial Senescence through SIRT1/p300/p53/p21 Pathway.

    Science.gov (United States)

    Zhang, Erli; Guo, Qianyun; Gao, Haiyang; Xu, Ruixia; Teng, Siyong; Wu, Yongjian

    2015-01-01

    Endothelial senescence plays crucial roles in diabetic vascular complication. Recent evidence indicated that transient hyperglycaemia could potentiate persistent diabetic vascular complications, a phenomenon known as "metabolic memory." Although SIRT1 has been demonstrated to mediate high glucose-induced endothelial senescence, whether and how "metabolic memory" would affect endothelial senescence through SIRT1 signaling remains largely unknown. In this study, we investigated the involvement of SIRT1 axis as well as the protective effects of resveratrol (RSV) and metformin (MET), two potent SIRT1 activators, during the occurrence of "metabolic memory" of cellular senescence (senescent "memory"). Human umbilical vascular endothelial cells (HUVECs) were cultured in either normal glucose (NG)/high glucose (HG) media for 6 days, or 3 days of HG followed by 3 days of NG (HN), with or without RSV or MET treatment. It was shown that HN incubation triggered persistent downregulation of deacetylase SIRT1 and upregulation of acetyltransferase p300, leading to sustained hyperacetylation (at K382) and activation of p53, and subsequent p53/p21-mediated senescent "memory." In contrast, senescent "memory" was abrogated by overexpression of SIRT1 or knockdown of p300. Interestingly, we found that SIRT1 and p300 could regulate each other in response to HN stimulation, suggesting that a delicate balance between acetyltransferases and deacetylases may be particularly important for sustained acetylation and activation of non-histone proteins (such as p53), and eventually the occurrence of "metabolic memory." Furthermore, we found that RSV or MET treatment prevented senescent "memory" by modulating SIRT1/p300/p53/p21 pathway. Notably, early and continuous treatment of MET, but not RSV, was particularly important for preventing senescent "memory." In conclusion, short-term high glucose stimulation could induce sustained endothelial senescence via SIRT1/p300/p53/p21 pathway. RVS or MET

  19. The continuing saga of the /sup 1/P/sub 1/ (q-barq) mesonic states

    International Nuclear Information System (INIS)

    Dalitz, R.H.; Tuan, S.F.

    1986-01-01

    The mesonic states predicted by the quark model to have the structure (q-barq) do not allow all combinations possible for the quantum numbers (JPC). The happy situation for the /sup 3/P/sub J/ states does not hold for the /sup 1/P/sub 1/ state. The experimenter is therefore faced by a double difficulty, the difficulty of forming the /sup 1/P/sub 1/ through the channels available to him and the difficulty of detecting the /sup 1/P/sub 1/ state when it is formed. The difficulty about the detection and study of /sup 1/P/sub 1/ states is not intrinsic but circumstantial. It is not intrinsic because the B-meson is readily produced and studied, the same being true for Q/sub B/, although this has been a more confused situation because of the mixing between the Q/sub A/ and Q/sub B/ states. Porter has devoted considerable attention to the search for the /sup 1/P/sub 1/ (c-barc) state and the authors outline that discussion in this paper. They also describe the formation of the state Psi' (3685), since this has a large cross section in e/sup +/e/sup -/ annihilation, and to look for the /sup 1/P/sub 1/ state as a product among its decay modes

  20. Expectation Consistent Approximate Inference

    DEFF Research Database (Denmark)

    Opper, Manfred; Winther, Ole

    2005-01-01

    We propose a novel framework for approximations to intractable probabilistic models which is based on a free energy formulation. The approximation can be understood from replacing an average over the original intractable distribution with a tractable one. It requires two tractable probability dis...

  1. Approximate number and approximate time discrimination each correlate with school math abilities in young children.

    Science.gov (United States)

    Odic, Darko; Lisboa, Juan Valle; Eisinger, Robert; Olivera, Magdalena Gonzalez; Maiche, Alejandro; Halberda, Justin

    2016-01-01

    What is the relationship between our intuitive sense of number (e.g., when estimating how many marbles are in a jar), and our intuitive sense of other quantities, including time (e.g., when estimating how long it has been since we last ate breakfast)? Recent work in cognitive, developmental, comparative psychology, and computational neuroscience has suggested that our representations of approximate number, time, and spatial extent are fundamentally linked and constitute a "generalized magnitude system". But, the shared behavioral and neural signatures between number, time, and space may alternatively be due to similar encoding and decision-making processes, rather than due to shared domain-general representations. In this study, we investigate the relationship between approximate number and time in a large sample of 6-8 year-old children in Uruguay by examining how individual differences in the precision of number and time estimation correlate with school mathematics performance. Over four testing days, each child completed an approximate number discrimination task, an approximate time discrimination task, a digit span task, and a large battery of symbolic math tests. We replicate previous reports showing that symbolic math abilities correlate with approximate number precision and extend those findings by showing that math abilities also correlate with approximate time precision. But, contrary to approximate number and time sharing common representations, we find that each of these dimensions uniquely correlates with formal math: approximate number correlates more strongly with formal math compared to time and continues to correlate with math even when precision in time and individual differences in working memory are controlled for. These results suggest that there are important differences in the mental representations of approximate number and approximate time and further clarify the relationship between quantity representations and mathematics. Copyright

  2. Approximation and Computation

    CERN Document Server

    Gautschi, Walter; Rassias, Themistocles M

    2011-01-01

    Approximation theory and numerical analysis are central to the creation of accurate computer simulations and mathematical models. Research in these areas can influence the computational techniques used in a variety of mathematical and computational sciences. This collection of contributed chapters, dedicated to renowned mathematician Gradimir V. Milovanovia, represent the recent work of experts in the fields of approximation theory and numerical analysis. These invited contributions describe new trends in these important areas of research including theoretic developments, new computational alg

  3. Approximate modal analysis using Fourier decomposition

    International Nuclear Information System (INIS)

    Kozar, Ivica; Jericevic, Zeljko; Pecak, Tatjana

    2010-01-01

    The paper presents a novel numerical approach for approximate solution of eigenvalue problem and investigates its suitability for modal analysis of structures with special attention on plate structures. The approach is based on Fourier transformation of the matrix equation into frequency domain and subsequent removal of potentially less significant frequencies. The procedure results in a much reduced problem that is used in eigenvalue calculation. After calculation eigenvectors are expanded and transformed back into time domain. The principles are presented in Jericevic [1]. Fourier transform can be formulated in a way that some parts of the matrix that should not be approximated are not transformed but are fully preserved. In this paper we present formulation that preserves central or edge parts of the matrix and compare it with the formulation that performs transform on the whole matrix. Numerical experiments on transformed structural dynamic matrices describe quality of the approximations obtained in modal analysis of structures. On the basis of the numerical experiments, from the three approaches to matrix reduction one is recommended.

  4. Resummation of perturbative QCD by pade approximants

    International Nuclear Information System (INIS)

    Gardi, E.

    1997-01-01

    In this lecture I present some of the new developments concerning the use of Pade Approximants (PA's) for resuming perturbative series in QCD. It is shown that PA's tend to reduce the renormalization scale and scheme dependence as compared to truncated series. In particular it is proven that in the limit where the β function is dominated by the 1-loop contribution, there is an exact symmetry that guarantees invariance of diagonal PA's under changing the renormalization scale. In addition it is shown that in the large β 0 approximation diagonal PA's can be interpreted as a systematic method for approximating the flow of momentum in Feynman diagrams. This corresponds to a new multiple scale generalization of the Brodsky-Lepage-Mackenzie (BLM) method to higher orders. I illustrate the method with the Bjorken sum rule and the vacuum polarization function. (author)

  5. Constrained Optimization via Stochastic approximation with a simultaneous perturbation gradient approximation

    DEFF Research Database (Denmark)

    Sadegh, Payman

    1997-01-01

    This paper deals with a projection algorithm for stochastic approximation using simultaneous perturbation gradient approximation for optimization under inequality constraints where no direct gradient of the loss function is available and the inequality constraints are given as explicit functions...... of the optimization parameters. It is shown that, under application of the projection algorithm, the parameter iterate converges almost surely to a Kuhn-Tucker point, The procedure is illustrated by a numerical example, (C) 1997 Elsevier Science Ltd....

  6. Regulation of P2Y1 receptor traffic by sorting Nexin 1 is retromer independent.

    Science.gov (United States)

    Nisar, Shaista; Kelly, Eamonn; Cullen, Pete J; Mundell, Stuart J

    2010-04-01

    The activity and traffic of G-protein coupled receptors (GPCRs) is tightly controlled. Recent work from our laboratory has shown that P2Y(1) and P2Y(12) responsiveness is rapidly and reversibly modulated in human platelets and that the underlying mechanism requires receptor trafficking as an essential part of this process. However, little is known about the molecular mechanisms underlying P2Y receptor traffic. Sorting nexin 1 (SNX1) has been shown to regulate the endosomal sorting of cell surface receptors either to lysosomes where they are downregulated or back to the cell surface. These functions may in part be due to interactions of SNX1 with the mammalian retromer complex. In this study, we investigated the role of SNX1 in P2Y receptor trafficking. We show that P2Y(1) receptors recycle via a slow recycling pathway that is regulated by SNX1, whereas P2Y(12) receptors return to the cell surface via a rapid route that is SNX1 independent. SNX1 inhibition caused a dramatic increase in the rate of P2Y(1) receptor recycling, whereas inhibition of Vps26 and Vps35 known to be present in retromer had no effect, indicating that SNX1 regulation of P2Y(1) receptor recycling is retromer independent. In addition, inhibition of SNX4, 6 and 17 proteins did not affect P2Y(1) receptor recycling. SNX1 has also been implicated in GPCR degradation; however, we provide evidence that P2Y receptor degradation is SNX1 independent. These data describe a novel function of SNX1 in the regulation of P2Y(1) receptor recycling and suggest that SNX1 plays multiple roles in endocytic trafficking of GPCRs.

  7. (p,n) and (n,p) reactions as probes of isovector giant monopole resonances

    International Nuclear Information System (INIS)

    Auerbach, N.; Bowman, J.D.; Franey, M.A.; Love, W.G.

    1983-01-01

    Nucleon charge exchange reactions are explored as prospective probes of isovector giant monopole resonances. Using charge exchange transition densities based on random-phase approximation sum rules, distorted wave impulse approximation calculations are made for the (p,n) and (n,p) reactions exciting the isovector giant monopole resonances in several nuclei at bombarding energies of 120 and 800 MeV. Based on our calculations, the charge exchange reactions at 800 MeV appear more promising

  8. The pMSSM10 after LHC Run 1

    International Nuclear Information System (INIS)

    De Vries, K.J.; Buchmueller, O.

    2015-04-01

    We present a frequentist analysis of the parameter space of the pMSSM10, in which the following 10 soft SUSY-breaking parameters are specified independently at the mean scalar top mass scale M SUSY ≡√(m t 1 m t 2 ): the gaugino masses M 1,2,3 , the 1st-and 2nd-generation squark masses m q 1 =m q 2 , the third-generation squark mass m q 3 , a common slepton mass M l and a common trilinear mixing parameter A, the Higgs mixing parameter μ, the pseudoscalar Higgs mass M A and tan β. We use the MultiNest sampling algorithm with ∝1.2 x 10 9 points to sample the pMSSM10 parameter space. A dedicated study shows that the sensitivities to strongly-interacting SUSY masses of ATLAS and CMS searches for jets, leptons+E T signals depend only weakly on many of the other pMSSM10 parameters. With the aid of the Atom and Scorpion codes, we also implement the LHC searches for EW-interacting sparticles and light stops, so as to confront the pMSSM10 parameter space with all relevant SUSY searches. In addition, our analysis includes Higgs mass and rate measurements using the HiggsSignals code, SUSY Higgs exclusion bounds, the measurements B-physics observables, EW precision observables, the CDM density and searches for spin-independent DM scattering. We show that the pMSSM10 is able to provide a SUSY interpretation of (g-2) μ , unlike the CMSSM, NUHM1 and NUHM2. As a result, we find (omitting Higgs rates) that the minimum χ 2 /d.o.f.=20.5/18 in the pMSSM10, corresponding to a χ 2 probability of 30.8 %, to be compared with χ 2 /d.o.f.=32.8/24(31.1/23)(30.3/22) in the CMSSM (NUHM1) (NUHM2). We display 1-dimensional likelihood functions for SUSY masses, and show that they may be significantly lighter in the pMSSM10 than in the CMSSM, NUHM1 and NUHM2. We discuss the discovery potential of future LHC runs, e + e - colliders and direct detection experiments.

  9. Some results in Diophantine approximation

    DEFF Research Database (Denmark)

    Pedersen, Steffen Højris

    the basic concepts on which the papers build. Among other it introduces metric Diophantine approximation, Mahler’s approach on algebraic approximation, the Hausdorff measure, and properties of the formal Laurent series over Fq. The introduction ends with a discussion on Mahler’s problem when considered......This thesis consists of three papers in Diophantine approximation, a subbranch of number theory. Preceding these papers is an introduction to various aspects of Diophantine approximation and formal Laurent series over Fq and a summary of each of the three papers. The introduction introduces...

  10. Calculations of resonances parameters for the ((2s2) 1Se, (2s2p) 1,3P0) and ((3s2) 1Se, (3s3p) 1,3P0) doubly excited states of helium-like ions with Z≤10 using a complex rotation method implemented in Scilab

    Science.gov (United States)

    Gning, Youssou; Sow, Malick; Traoré, Alassane; Dieng, Matabara; Diakhate, Babacar; Biaye, Mamadi; Wagué, Ahmadou

    2015-01-01

    In the present work a special computational program Scilab (Scientific Laboratory) in the complex rotation method has been used to calculate resonance parameters of ((2s2) 1Se, (2s2p) 1,3P0) and ((3s2) 1Se, (3s3p) 1,3P0) states of helium-like ions with Z≤10. The purpose of this study required a mathematical development of the Hamiltonian applied to Hylleraas wave function for intrashell states, leading to analytical expressions which are carried out under Scilab computational program. Results are in compliance with recent theoretical calculations.

  11. SUMO regulates p21Cip1 intracellular distribution and with p21Cip1 facilitates multiprotein complex formation in the nucleolus upon DNA damage.

    Science.gov (United States)

    Brun, Sonia; Abella, Neus; Berciano, Maria T; Tapia, Olga; Jaumot, Montserrat; Freire, Raimundo; Lafarga, Miguel; Agell, Neus

    2017-01-01

    We previously showed that p21Cip1 transits through the nucleolus on its way from the nucleus to the cytoplasm and that DNA damage inhibits this transit and induces the formation of p21Cip1-containing intranucleolar bodies (INoBs). Here, we demonstrate that these INoBs also contain SUMO-1 and UBC9, the E2 SUMO-conjugating enzyme. Furthermore, whereas wild type SUMO-1 localized in INoBs, a SUMO-1 mutant, which is unable to conjugate with proteins, does not, suggesting the presence of SUMOylated proteins at INoBs. Moreover, depletion of the SUMO-conjugating enzyme UBC9 or the sumo hydrolase SENP2 changed p21Cip1 intracellular distribution. In addition to SUMO-1 and p21Cip1, cell cycle regulators and DNA damage checkpoint proteins, including Cdk2, Cyclin E, PCNA, p53 and Mdm2, and PML were also detected in INoBs. Importantly, depletion of UBC9 or p21Cip1 impacted INoB biogenesis and the nucleolar accumulation of the cell cycle regulators and DNA damage checkpoint proteins following DNA damage. The impact of p21Cip1 and SUMO-1 on the accumulation of proteins in INoBs extends also to CRM1, a nuclear exportin that is also important for protein translocation from the cytoplasm to the nucleolus. Thus, SUMO and p21Cip1 regulate the transit of proteins through the nucleolus, and that disruption of nucleolar export by DNA damage induces SUMO and p21Cip1 to act as hub proteins to form a multiprotein complex in the nucleolus.

  12. Test of distorted wave kinematic coupling approximation calculations for knockout reactions

    International Nuclear Information System (INIS)

    Jain, A.K.

    1990-01-01

    A test has been devised to check the validity of conventional distorted-wave impulse approximation (DWIA) treatment of knockout reactions. The conventional DWIA formalism separates the three-body final state Schroedinger equation for a knockout reaction into two two-body Schroedinger equations by assuming an asymptotic constant value for the three-body coupling term commonly known as the kinematic coupling approximation (KCA). In the test case, which consists of an extreme asymmetric situation where one of the distorting optical potentials is assumed to vanish, the three-body final state Schroedinger equation can be solved exactly as a product of two two-body solutions using one particular set of relative coordinates. Large influence of the three-body coupling term is seen in the comparison of the exact and KCA results for (α,2α) and (p,pα) knockout reactions when the distorting optical potentials are weakly absorbing

  13. Bounded-Degree Approximations of Stochastic Networks

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, Christopher J.; Pinar, Ali; Kiyavash, Negar

    2017-06-01

    We propose algorithms to approximate directed information graphs. Directed information graphs are probabilistic graphical models that depict causal dependencies between stochastic processes in a network. The proposed algorithms identify optimal and near-optimal approximations in terms of Kullback-Leibler divergence. The user-chosen sparsity trades off the quality of the approximation against visual conciseness and computational tractability. One class of approximations contains graphs with speci ed in-degrees. Another class additionally requires that the graph is connected. For both classes, we propose algorithms to identify the optimal approximations and also near-optimal approximations, using a novel relaxation of submodularity. We also propose algorithms to identify the r-best approximations among these classes, enabling robust decision making.

  14. Cloning and tissue expression of cytochrome P450 1B1 and 1C1 ...

    African Journals Online (AJOL)

    Cytochrome P450 1 (CYP1) is widely used as an indicator of exposure to environmental contaminants. In the study, two full-length complementary DNAs encode for CYP1B1 and CYP1C1 were cloned from medaka liver exposed to 500 ppb β-naphthoflavone for 24 h. CYP1B1, having 1984 bp, contains an open reading ...

  15. Anti-liver-kidney microsome antibody type 1 recognizes human cytochrome P450 db1.

    Science.gov (United States)

    Gueguen, M; Yamamoto, A M; Bernard, O; Alvarez, F

    1989-03-15

    Anti-liver-kidney microsome antibody type 1 (LKM1), present in the sera of a group of children with autoimmune hepatitis, was recently shown to recognize a 50 kDa protein identified as rat liver cytochromes P450 db1 and db2. High homology between these two members of the rat P450 IID subfamily and human P450 db1 suggested that anti-LKM1 antibody is directed against this human protein. To test this hypothesis, a human liver cDNA expression library in phage lambda GT-11 was screened using rat P450 db1 cDNA as a probe. Two human cDNA clones were found to be identical to human P450 db1 by restriction mapping. Immunoblot analysis using as antigen, the purified fusion protein from one of the human cDNA clones showed that only anti-LKM1 with anti-50 kDa reactivity recognized the fusion protein. This fusion protein was further used to develop an ELISA test that was shown to be specific for sera of children with this disease. These results: 1) identify the human liver antigen recognized by anti-LKM1 auto-antibodies as cytochrome P450 db1, 2) allow to speculate that mutation on the human P450 db1 gene could alter its expression in the hepatocyte and make it auto-antigenic, 3) provide a simple and specific diagnostic test for this disease.

  16. Space-angle approximations in the variational nodal method

    International Nuclear Information System (INIS)

    Lewis, E. E.; Palmiotti, G.; Taiwo, T.

    1999-01-01

    The variational nodal method is formulated such that the angular and spatial approximations maybe examined separately. Spherical harmonic, simplified spherical harmonic, and discrete ordinate approximations are coupled to the primal hybrid finite element treatment of the spatial variables. Within this framework, two classes of spatial trial functions are presented: (1) orthogonal polynomials for the treatment of homogeneous nodes and (2) bilinear finite subelement trial functions for the treatment of fuel assembly sized nodes in which fuel-pin cell cross sections are represented explicitly. Polynomial and subelement trial functions are applied to benchmark water-reactor problems containing MOX fuel using spherical harmonic and simplified spherical harmonic approximations. The resulting accuracy and computing costs are compared

  17. Biochemical and immunological characterization of recombinant allergen Lol p 1.

    Science.gov (United States)

    Tamborini, E; Faccini, S; Lidholm, J; Svensson, M; Brandazza, A; Longhi, R; Groenlund, H; Sidoli, A; Arosio, P

    1997-11-01

    Pollen from perennial rye grass (Lolium perenne), a major cause of type-I allergy worldwide, contains a complex mixture of allergenic proteins among which Lol p 1 is one of the most important. We describe the expression, purification and characterization of a recombinant Lol p 1 overproduced in Escherichia coli. The recombinant allergen, expressed in high yields and purified in milligram amounts, bound to specific IgE antibodies from human sera, induced histamine release from sensitized human basophils, and elicited rabbit antisera that recognize specifically recombinant Lol p 1 and natural Lol p 1 of pollen extract. Recombinant Lol p 1 was used to develop ImmunoCAP assays for analysis of 150 sera that were Radioallergosorbent test positive to L. perenne pollen. In 130 of them (87%) the assay detected a significant level of IgE antibodies to Lol p 1, reaching on average 37% of the level obtained with a test for IgE to the whole grass pollen extract. To map epitopes on Lol p 1, we produced three deletion mutants [des-(116-240)-Lol p 1, des-(1-88)-Lol p 1 and des-(133-189)-Lol p 1], which were efficiently expressed in bacteria. These all showed a strong reactivity with the specific rabbit IgG antibodies, but lacked most or all the allergenic properties of recombinant Lol p 1. A study of the antigenic structure of Lol p 1 was performed using the three deletion mutants and a set of 17-18-residue overlapping synthetic peptides covering the whole allergen sequence. The results indicate that human IgE and rabbit IgG antibodies bind to distinct regions of Lol p 1, and that at least some important IgE epitopes are mainly conformational. The findings suggest that recombinant allergens constitute useful reagents for further development of serological diagnosis of allergy, and that it should be possible to produce immunogenic fragments of allergenic proteins without allergenic properties.

  18. Crystal Structure of the Yeast Nicotinamidase Pnc1p

    OpenAIRE

    Hu, Gang; Taylor, Alexander B.; McAlister-Henn, Lee; Hart, P. John

    2007-01-01

    The yeast nicotinamidase Pnc1p acts in transcriptional silencing by reducing levels of nicotinamide, an inhibitor of the histone deacetylase Sir2p. The Pnc1p structure was determined at 2.9 Å resolution using MAD and MIRAS phasing methods after inadvertent crystallization during the pursuit of the structure of histidine-tagged yeast isocitrate dehydrogenase (IDH). Pnc1p displays a cluster of surface histidine residues likely responsible for its co-fractionation with IDH from Ni2+-coupled chro...

  19. Exit Strategies: S1P Signaling and T Cell Migration.

    Science.gov (United States)

    Baeyens, Audrey; Fang, Victoria; Chen, Cynthia; Schwab, Susan R

    2015-12-01

    Whereas the role of sphingosine 1-phosphate receptor 1 (S1PR1) in T cell egress and the regulation of S1P gradients between lymphoid organs and circulatory fluids in homeostasis are increasingly well understood, much remains to be learned about S1P signaling and distribution during an immune response. Recent data suggest that the role of S1PR1 in directing cells from tissues into circulatory fluids is reprised again and again, particularly in guiding activated T cells from non-lymphoid tissues into lymphatics. Conversely, S1P receptor 2 (S1PR2), which antagonizes migration towards chemokines, confines cells within tissues. Here we review the current understanding of the roles of S1P signaling in activated T cell migration. In this context, we outline open questions, particularly regarding the shape of S1P gradients in different tissues in homeostasis and inflammation, and discuss recent strategies to measure S1P. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Juvenile Moyamoya and Craniosynostosis in a Child with Deletion 1p32p31: Expanding the Clinical Spectrum of 1p32p31 Deletion Syndrome and a Review of the Literature

    Directory of Open Access Journals (Sweden)

    Paolo Prontera

    2017-09-01

    Full Text Available Moyamoya angiopathy (MA is a rare cerebrovascular disorder characterised by the progressive occlusion of the internal carotid artery. Its aetiology is uncertain, but a genetic background seems likely, given the high MA familial rate. To investigate the aetiology of craniosynostosis and juvenile moyamoya in a 14-year-old male patient, we performed an array-comparative genomic hybridisation revealing a de novo interstitial deletion of 8.5 Mb in chromosome region 1p32p31. The deletion involved 34 protein coding genes, including NF1A, whose haploinsufficiency is indicated as being mainly responsible for the 1p32-p31 chromosome deletion syndrome phenotype (OMIM 613735. Our patient also has a deleted FOXD3 of the FOX gene family of transcription factors, which plays an important role in neural crest cell growth and differentiation. As the murine FOXD3−/− model shows craniofacial anomalies and abnormal common carotid artery morphology, it can be hypothesised that FOXD3 is involved in the pathogenesis of the craniofacial and vascular defects observed in our patient. In support of our assumption, we found in the literature another patient with a syndromic form of MA who had a deletion involving another FOX gene (FOXC1. In addition to describing the clinical history of our patient, we have reviewed all of the available literature concerning other patients with a 1p32p31 deletion, including cases from the Decipher database, and we have also reviewed the genetic disorders associated with MA, which is a useful guide for the diagnosis of syndromic form of MA.

  1. Distinct HIC1-SIRT1-p53 Loop Deregulation in Lung Squamous Carcinoma and Adenocarcinoma Patients

    Directory of Open Access Journals (Sweden)

    Ruo-Chia Tseng

    2009-08-01

    Full Text Available A HIC1-SIRT1-p53 circular loop in which hypermethylation in cancer 1 (HIC1 represses the transcription of SIRT1 that deacetylates and inactivates p53 thus leading to HIC1 inactivation has been identified in cell and animal models. However, the alteration and prognostic effects of HIC1-SIRT1-p53 circular loop have never been demonstrated in human cancer patients. We examine the HIC1-SIRT1-p53 alterations in 118 lung cancer patients to define their etiological roles in tumorigenesis. We found that patients with lung squamous cell carcinoma with low p53 acetylation and SIRT1 expression mostly showed low HIC1 expression, confirming deregulation of HIC1-SIRT1-p53 circular loop in the clinical model. Interestingly, the expression of deleted in breast cancer 1 (DBC1, which blocks the interaction between SIRT1 deacetylase and p53, led to acetylated p53 in patients with lung adenocarcinoma. However, epigenetic alteration of HIC1 promoter by posttranslational modifications of histones and promoter hypermethylation favoring the compacted chromatin production attenuated the transcriptional induction by acetylated p53. Importantly, lung cancer patients with altered HIC1-SIRT1-p53 circular regulation showed poor prognosis. Our data show the first valid clinical evidence of the deregulation of HIC1-SIRT1-p53 loop in lung tumorigenesis and prognosis. Distinct status of p53 acetylation/deacetylation and HIC1 alteration mechanism result from different SIRT1-DBC1 control and epigenetic alteration in lung squamous cell carcinoma and lung adenocarcinoma.

  2. Crystal structure of the yeast nicotinamidase Pnc1p.

    Science.gov (United States)

    Hu, Gang; Taylor, Alexander B; McAlister-Henn, Lee; Hart, P John

    2007-05-01

    The yeast nicotinamidase Pnc1p acts in transcriptional silencing by reducing levels of nicotinamide, an inhibitor of the histone deacetylase Sir2p. The Pnc1p structure was determined at 2.9A resolution using MAD and MIRAS phasing methods after inadvertent crystallization during the pursuit of the structure of histidine-tagged yeast isocitrate dehydrogenase (IDH). Pnc1p displays a cluster of surface histidine residues likely responsible for its co-fractionation with IDH from Ni(2+)-coupled chromatography resins. Researchers expressing histidine-tagged proteins in yeast should be aware of the propensity of Pnc1p to crystallize, even when overwhelmed in concentration by the protein of interest. The protein assembles into extended helical arrays interwoven to form an unusually robust, yet porous superstructure. Comparison of the Pnc1p structure with those of three homologous bacterial proteins reveals a common core fold punctuated by amino acid insertions unique to each protein. These insertions mediate the self-interactions that define the distinct higher order oligomeric states attained by these molecules. Pnc1p also acts on pyrazinamide, a substrate analog converted by the nicotinamidase from Mycobacterium tuberculosis into a product toxic to that organism. However, we find no evidence for detrimental effects of the drug on yeast cell growth.

  3. Measurement of the production cross section ratio $\\sigma(\\chi_{b2}(1\\mathrm{P}))/ \\sigma(\\chi_{b1}(1\\mathrm{P}))$ in pp collisions at $\\sqrt{s}$ = 8 TeV

    CERN Document Server

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