7,354 research outputs found

    Deep Space Network utilization for flight projects, calendar year 1981

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    A report on the utilization of the Deep Space Network during calendar year 1981 in support of all flight projects is presented. The network expended 63% of its total capability in support of Space Flight projects

    Requirement of the FATC domain of protein kinase Tel1 for localization to DNA ends and target protein recognition

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    Two large phosphatidylinositol 3-kinase-related protein kinases (PIKKs), ATM and ATR, play a central role in the DNA damage response pathway. PIKKs contain a highly conserved extreme C-terminus called the FRAP-ATM-TRRAP-C-terminal (FATC) domain. In budding yeast, ATM and ATR correspond to Tel1 and Mec1, respectively. In this study, we characterized functions of the FATC domain of Tel1 by introducing substitution or truncation mutations. One substitution mutation, termed tel1-21, and a truncation mutation, called tel1- Î"C, did not significantly affect the expression level. The tel1-21 mutation impaired the cellular response to DNA damage and conferred moderate telomere maintenance defect. In contrast, the tel1-Î"C mutation behaved like a null mutation, conferring defects in both DNA damage response and telomere maintenance. Tel1-21 protein localized to DNA ends as effectively as wild-type Tel1 protein, whereas Tel1-Î"C protein failed. Introduction of a hyperactive TEL1-hy mutation suppressed the tel1-21 mutation but not the tel1-Î"C mutation. In vitro analyses revealed that both Tel1-21 and Tel1-Î"C proteins undergo efficient autophosphorylation but exhibit decreased kinase activities toward the exogenous substrate protein, Rad53. Our results show that the FATC domain of Tel1 mediates localization to DNA ends and contributes to phosphorylation of target proteins. © 2015 Ogi, Goto, Ghosh, et al

    Design for adaption - Making timber buildings ready for circular use and extended service life

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    The construction sector has a significant share of Green House Gas emission and raw material consumption globally. Among common construction materials, timber has a long tradition of numerous applications as a renewable material. The implementation of the concept of circularity in the process of the construction of timber buildings has a high potential sustainability impact. The concept of design for adaption is to extend the service life of timber building to the maximum in several life cycles. In this paper the demand regarding circularity is analysed from interviews with different stakeholders and their economic, social and environmental incentive. The possibility to assess the sustainability impact of design for adaption are evaluated. Different examples of existing practices and potential solutions for design for deconstruction and adaption are summarized

    Efficient LZ78 factorization of grammar compressed text

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    We present an efficient algorithm for computing the LZ78 factorization of a text, where the text is represented as a straight line program (SLP), which is a context free grammar in the Chomsky normal form that generates a single string. Given an SLP of size nn representing a text SS of length NN, our algorithm computes the LZ78 factorization of TT in O(nN+mlogN)O(n\sqrt{N}+m\log N) time and O(nN+m)O(n\sqrt{N}+m) space, where mm is the number of resulting LZ78 factors. We also show how to improve the algorithm so that the nNn\sqrt{N} term in the time and space complexities becomes either nLnL, where LL is the length of the longest LZ78 factor, or (Nα)(N - \alpha) where α0\alpha \geq 0 is a quantity which depends on the amount of redundancy that the SLP captures with respect to substrings of SS of a certain length. Since m=O(N/logσN)m = O(N/\log_\sigma N) where σ\sigma is the alphabet size, the latter is asymptotically at least as fast as a linear time algorithm which runs on the uncompressed string when σ\sigma is constant, and can be more efficient when the text is compressible, i.e. when mm and nn are small.Comment: SPIRE 201

    O(αs)O(\alpha_s) Corrections to BXse+eB \to X_s e^+ e^- Decay in the 2HDM

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    O(αs)O(\alpha_s) QCD corrections to the inclusive BXse+eB \to X_s e^+ e^- decay are investigated within the two - Higgs doublet extension of the standard model (2HDM). The analysis is performed in the so - called off-resonance region; the dependence of the obtained results on the choice of the renormalization scale is examined in details. It is shown that O(αs)O(\alpha_s) corrections can suppress the BXse+eB \to X_s e^+ e^- decay width up to 1.5÷31.5 \div 3 times (depending on the choice of the dilepton invariant mass ss and the low - energy scale μ\mu). As a result, in the experimentally allowed range of the parameters space, the relations between the BXse+eB \to X_s e^+ e^- branching ratio and the new physics parameters are strongly affected. It is found also that though the renormalization scale dependence of the BXse+eB \to X_s e^+ e^- branching is significantly reduced, higher order effects in the perturbation theory can still be nonnegligible.Comment: 16 pages, latex, including 6 figures and 3 table

    Anomalous magnetotransport in (Y1x_{1-x}Gdx_{x})Co2_{2} alloys: interplay of disorder and itinerant metamagnetism

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    New mechanism of magnetoresistivity in itinerant metamagnets with a structural disorder is introduced basing on analysis of experimental results on magnetoresistivity, susceptibility, and magnetization of structurally disordered alloys (Y1x_{1-x}Gdx_{x})Co2_{2}. In this series, YCo2_{2} is an enhanced Pauli paramagnet, whereas GdCo2_{2} is a ferrimagnet (Tc_{\rm c}=400 K) with Gd sublattice coupled antiferromagnetically to the itinerant Co-3d electrons. The alloys are paramagnetic for x<0.12x < 0.12. Large positive magnetoresistivity has been observed in the alloys with magnetic ground state at temperatures T<<Tc_{\rm c}. We show that this unusual feature is linked to a combination of structural disorder and metamagnetic instability of itinerant Co-3d electrons. This new mechanism of the magnetoresistivity is common for a broad class of materials featuring a static magnetic disorder and itinerant metamagnetism.Comment: 7 pages 7 figure

    Quadrupolar effect and rattling motion in heavy fermion superconductor PrOs_4Sb_{12}

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    The elastic properties of a filled skutterudite PrOs_4Sb_{12} with a heavy Fermion superconductivity at T_C=1.85 K have been investigated. The elastic softening of (C_{11}-C_{12})/2 and C_{44} with lowering temperature down to T_C indicates that the quadrupolar fluctuation due to the CEF state plays a role for the Cooper paring in superconducting phase of PrOs_4Sb_{12}. A Debye-type dispersion in the elastic constants around 30 K revealed a thermally activated Gamma_{23} rattling due to the off-center Pr-atom motion obeying tau=tau_{0}exp(E/k_{B}T) with an attempt time tau_0=8.8*10^{-11} sec and an activation energy E=168 K. It is remarkable that the charge fluctuation of the off-center motion with Gamma_{23} symmetry may mix with the quadrupolar fluctuation and enhance the elastic softening of (C_{11}-C_{12})/2 just above T_C.Comment: 5 pages, 4 figures, to be published to Phys. Rev.

    On the equivalence principle and gravitational and inertial mass relation of classical charged particles

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    We show that the locally constant force necessary to get a stable hyperbolic motion regime for classical charged point particles, actually, is a combination of an applied external force and of the electromagnetic radiation reaction force. It implies, as the strong Equivalence Principle is valid, that the passive gravitational mass of a charged point particle should be slight greater than its inertial mass. An interesting new feature that emerges from the unexpected behavior of the gravitational and inertial mass relation, for classical charged particles, at very strong gravitational field, is the existence of a critical, particle dependent, gravitational field value that signs the validity domain of the strong Equivalence Principle. For electron and proton, these critical field values are gc4.8×1031m/s2g_{c}\simeq 4.8\times 10^{31}m/s^{2} and gc8.8×1034m/s2g_{c}\simeq 8.8\times 10^{34}m/s^{2}, respectively

    Hole Doping Effects on Spin-gapped Na2Cu2TeO6 via Topochemical Na Deficiency

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    We report the magnetic susceptibility and NMR studies of a spin-gapped layered compound Na2Cu2TeO6 (the spin gap Δ\Delta\sim 250 K), the hole doping effect on the Cu2TeO6 plane via a topochemical Na deficiency by soft chemical treatment, and the static spin vacancy effect by nonmagnetic impurity Zn substitution for Cu. A finite Knight shift at the 125^{125}Te site was observed for pure Na2Cu2TeO6. The negative hyperfine coupling constant 125Atr^{125}A_{tr} is an evidence for the existence of a superexchange pathway of the Cu-O-Te-O-Cu bond. It turned out that both the Na deficiency and Zn impurities induce a Curie-type magnetism in the uniform spin susceptibility in an external magnetic field of 1 T, but only the Zn impurities enhance the low-temperature 23^{23}Na nuclear spin-lattice relaxation rate whereas the Na deficiency suppresses it. A spin glass behavior was observed for the Na-deficient samples but not for the Zn-substituted samples. The dynamics of the unpaired moments of the doped holes are different from that of the spin vacancy in the spin-gapped Cu2TeO6 planes.Comment: 4 pages, 7 figures, to be published in J. Phys. Soc. Jpn. Vol. 75, No. 8 (2006

    Quadrupole Susceptibility of Gd-Based Filled Skutterudite Compounds

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    It is shown that quadrupole susceptibility can be detected in Gd compounds contrary to our textbook knowledge that Gd3+^{3+} ion induces pure spin moment due to the Hund's rules in an LSLS coupling scheme. The ground-state multiplet of Gd3+^{3+} is always characterized by JJ=7/2, where JJ denotes total angular momentum, but in a jj-jj coupling scheme, one ff electron in jj=7/2 octet carries quadrupole moment, while other six electrons fully occupy jj=5/2 sextet, where jj denotes one-electron total angular momentum. For realistic values of Coulomb interaction and spin-orbit coupling, the ground-state wavefunction is found to contain significant amount of the jj-jj coupling component. From the evaluation of quadrupole susceptibility in a simple mean-field approximation, we point out a possibility to detect the softening of elastic constant in Gd-based filled skutterudites.Comment: 8 pages, 4 figure
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