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Sample records for 2p core levels

  1. Detection of subsurface core-level shifts in Si 2p core-level photoemission from Si(111)-(1x1):As

    SciTech Connect

    Paggel, J.J.; Hasselblatt, M.; Horn, K.

    1997-04-01

    The (7 x 7) reconstruction of the Si(111) surface arises from a lowering energy through the reduction of the number of dangling bonds. This reconstruction can be removed by the adsorption of atoms such as hydrogen which saturate the dangling bonds, or by the incorporation of atoms, such as arsenic which, because of the additional electron it possesses, can form three bonds and a nonreactive lone pair orbital from the remaining two electrons. Core and valence level photoemission and ion scattering data have shown that the As atoms replace the top silicon atoms. Previous core level spectra were interpreted in terms of a bulk and a single surface doublet. The authors present results demonstrate that the core level spectrum contains two more lines. The authors assign these to subsurface silicon layers which also experience changes in the charge distribution when a silicon atom is replaced by an arsenic atom. Subsurface core level shifts are not unexpected since the modifications of the electronic structure and/or of photohole screening are likely to decay into the bulk and not just to affect the top-most substrate atoms. The detection of subsurface components suggests that the adsorption of arsenic leads to charge flow also in the second double layer of the Si(111) surface. In view of the difference in atomic radius between As and Si, it was suggested that the (1 x 1): As surface is strained. The presence of charge rearrangement up to the second double layer implies that the atomic coordinates also exhibit deviations from their ideal Si(111) counterparts, which might be detected through a LEED I/V or photoelectron diffraction analysis.

  2. Structural origin of Si-2p core-level shifts from Si(100)-c[4x2] surface: A spectral x-ray photoelectron diffraction study

    SciTech Connect

    Chen, X.; Tonner, B.P.; Denlinger, J.

    1997-04-01

    The authors have performed angle-resolved x-ray photoelectron diffraction (XPD) from a Si(100)-c(4x2) surface to study the structural origin of Si-2p core-level shifts. In the experiment, the highly resolved surface Si-2p core-level spectra were measured as a fine grid of hemisphere and photon energies, using the SpectroMicroscopy Facility {open_quotes}ultraESCA{close_quotes} instrument. By carefully decomposing the spectra into several surface peaks, the authors are able to obtain surface-atom resolved XPD patterns. Using a multiple scattering analysis, they derived a detailed atomic model for the Si(100)-c(4x2) surface. In this model, the asymmetric dimers were found tilted by 11.5 plus/minus 2.0 degrees with bond length of 2.32 plus/minus 0.05{angstrom}. By matching model XPD patterns to experiment, the authors can identify which atoms in the reconstructed surface are responsible for specific photoemission lines in the 2p spectrum.

  3. Hidden relationship between the electrical conductivity and the Mn 2p core-level photoemission spectra in La{sub 1-x}Sr{sub x}MnO{sub 3}

    SciTech Connect

    Hishida, T.; Ohbayashi, K.; Saitoh, T.

    2013-01-28

    Core-level electronic structure of La{sub 1-x}Sr{sub x}MnO{sub 3} has been studied by x-ray photoemission spectroscopy (XPS). We first report, by the conventional XPS, the well-screened shoulder structure in Mn 2p{sub 3/2} peak, which had been observed only by hard x-ray photoemission spectroscopy so far. Multiple-peak analysis revealed that the Mn{sup 4+} spectral weight was not proportional to the nominal hole concentration x, indicating that a simple Mn{sup 3+}/Mn{sup 4+} intensity ratio analysis may result in a wrong quantitative elemental analysis. Considerable weight of the shoulder at x = 0.0 and the fact that the shoulder weight was even slightly going down from x = 0.2 to 0.4 were not compatible with the idea that this weight simply represents the metallic behavior. Further analysis found that the whole Mn 2p{sub 3/2} peak can be decomposed into four portions, the Mn{sup 4+}, the (nominal) Mn{sup 3+}, the shoulder, and the other spectral weight located almost at the Mn{sup 3+} location. We concluded that this weight represents the well-screened final state at Mn{sup 4+} sites, whereas the shoulder is known as that of the Mn{sup 3+} states. We found that the sum of these two spectral weight has an empirical relationship to the conductivity evolution with x.

  4. Electron-ion-ion triple-coincidence spectroscopic study of site-specific fragmentation caused by Si:2p core-level photoionization of F{sub 3}SiCH{sub 2}CH{sub 2}Si(CH{sub 3}){sub 3} vapor

    SciTech Connect

    Nagaoka, S.; Hino, M.; Takemoto, M.; Pruemper, G.; Fukuzawa, H.; Liu, X.-J.; Lischke, T.; Ueda, K.; Tamenori, Y.; Harries, J.; Suzuki, I. H.; Takahashi, O.; Okada, K.; Tabayashi, K.

    2007-02-15

    Site-specific fragmentation caused by Si:2p core-level photoionization of F{sub 3}SiCH{sub 2}CH{sub 2}Si(CH{sub 3}){sub 3} vapor was studied by means of high-resolution energy-selected-electron photoion-photoion triple-coincidence spectroscopy. The ab initio molecular orbital method was used for the theoretical description. F{sub 3}SiCH{sub 2}CH{sub 2}{sup +}-Si(CH{sub 3}){sub 3}{sup +} ion pairs were produced by the 2p photoionization of the Si atoms bonded to the three methyl groups, and SiF{sup +}-containing ion pairs were produced by the 2p photoionization of the Si atoms bonded to the three F atoms.

  5. Al 2p core exciton in AlxGa1-xAs

    NASA Astrophysics Data System (ADS)

    Nithianandam, Jeyasingh; Schnatterly, Stephen E.

    1990-08-01

    Al L2,3 x-ray emission spectra from AlxGa1-xAs of varying aluminum concentration are presented. The nature of the Al 2p core exciton observed in these spectra is discussed. Some comments are also made on the effects of anion disorder in these alloys.

  6. Precision lifetime measurements of the 2p levels in lithium

    SciTech Connect

    Berry, H.G.; Kurtz, C.; Tanner, C.E.

    1995-08-01

    These measurements are motivated by the theoretical challenges posed by lithium. The three-electron lithium atom is one of the simplest atomic systems with which to test atomic structure calculations. Recently, there were several ab initio calculations of the lithium 2s-2p oscillator strengths, which agree to 0.15%. However, the theoretical results differ by 5 sigma from the precise fast-beam-laser lifetime measurement of Gaupp and Andra (Berlin). Hence the need for a new independent and precise measurement. Improvements were added to the fast beam laser techniques developed for cesium in order to measure the lithium 2p state lifetime. Although the technique is similar to that of cesium, the lithium atom presents a few new complications. Since the atom is lighter, it travels more quickly through the interaction and detection regions. Therefore, the 670 nm wavelength requires a dye laser to produce sufficient intensity to populate the excited state. Unfortunately, the intensity of the dye laser is inherently less stable than that of a diode laser. Another complication is that the ion-beam intensity is much more sensitive to fluctuations in the accelerating voltage. Two detectors were added: one to monitor the ion-beam intensity, and the other to monitor the laser power. With the information from the additional detectors, a new data analysis scheme was developed. Sufficient data were taken to evaluate the benefits of the new detectors. No additional work is planned at Argonne for this experiment.

  7. Photoexcitation and photoionization from the 2p53p[5/2]2,3 levels in neon

    NASA Astrophysics Data System (ADS)

    Baig, M. A.; Bokhari, I. A.; Rafiq, M.; Kalyar, M. A.; Hussian, T.; Ali, Raheel; Piracha, N. K.

    2011-07-01

    We present measurements of the excitation spectra from the 2p53p [5/2]3,2 levels in neon using two-step laser excitation and ionization in conjunction with an optogalvanic detection in dc and rf discharge cells. The 2p53p [5/2]3,2 intermediate levels have been approached via the collisionally populated 2p53s [3/2]2 metastable level. The Rydberg series 2p5(2P3/2)nd [7/2]4 (12 ⩽ n ⩽ 44), 2p5(2P3/2)ns [3/2]2 (13 ⩽ n ⩽ 35) and the parity forbidden transitions 2p5(2P3/2)np [5/2]3 (13 ⩽ n ⩽ 19) have been observed from the 2p53p [5/2]3 level, whereas the 2p5(2P3/2)nd [7/2]3 (12 ⩽ n ⩽ 44), 2p5(2P3/2)ns [3/2]2 (13 ⩽ n ⩽ 35), and 2p5(2P1/2)nd' [5/2]3 (9 ⩽ n ⩽ 12) Rydberg series have been observed from the 2p53p[5/2]2 level in accordance with the ΔJ = ΔK = ± 1 selection rules. The photoionization cross sections from the 2p53p [5/2]3 intermediate level have been measured at eight ionizing laser wavelengths (399, 395, 390, 385, 380, 370, 364, and 355 nm) and that from the 2p53p [5/2]2 level at 401.8 nm. These measurements are in excellent agreement with the experimental values reported in the literature, while the experimental data lie much below the theoretically calculated photoionization cross sections curve.

  8. Lamb shift in the hydrogen atom: Lifetime of the 2p{1/2}level

    SciTech Connect

    Karshenboim, S.G.

    1995-05-01

    Corrections of order {alpha}(Z{alpha}){sup 2} to the width of the 2p{1/2} level in the hydrogen atom are considered in the logarithmic approximation. The ratio of this width to the splitting of n=2 states can be measured to high accuracy. With the aid of the experimental data available for this ratio, the new value for the Lamb splitting is found to be 1057.8576(21) MHz. 17 refs.

  9. Beam-foil spectroscopical study of the 1s2s2p and 1s2p 2 quartet levels of Mg 9+ and Al 10+

    NASA Astrophysics Data System (ADS)

    Hellmann, H.; Träbert, E.

    1985-07-01

    Results of recent measurements of the fine structure and multiplet separation of the lowest quartet terms of doubly excited three-electron ions of Mg and Al are compared with other experiments and with theory. Preliminary results of lifetime measurements of 1s2p 24P 1/2.3/2 levels are presented. They confirm the recent calculation by Chen. Crasemann and Mark and contradict older calculations by Tunnell and Bhalla.

  10. High-pressure polymorphism of Fe[subscript 2]P and its implications for meteorites and Earth's core

    SciTech Connect

    Dera, P.; Lavina, B.; Borkowski, L.A.; Prakapenka, V.B.; Sutton, S.R.; Rivers, M.L.; Downs, R.T.; Boctor, N.Z.; Prewitt, C.T.

    2008-05-19

    Minerals with composition (Fe,Ni){sub 2}P, are rare, though important accessory phases in iron and chondritic meteorites. The occurrence of these minerals in meteorites is believed to originate either from the equilibrium condensation of protoplanetary materials in solar nebulae or from the later accretion and condensation processes in the cores of parent bodies. Fe-Ni phosphides are considered a possible candidate for a minor phase present in the Earth's core, and at least partially responsible for the observed density deficit with respect to pure iron. We report results of high-pressure high-temperature X-ray diffraction experiments with synthetic barringerite (Fe{sub 2}P) up to 40 GPa and 1400 K. A new phase transition to the Co{sub 2}Si-type structure has been found at 8.0 GPa, upon heating. The high-pressure phase can be metastably quenched to ambient conditions at room temperature, and then, if heated again, transforms back to barringerite, providing an important constraint on the thermodynamic history of meteorite.

  11. Characterizing the Global Impact of P2P Overlays on the AS-Level Underlay

    NASA Astrophysics Data System (ADS)

    Rasti, Amir Hassan; Rejaie, Reza; Willinger, Walter

    This paper examines the problem of characterizing and assessing the global impact of the load imposed by a Peer-to-Peer (P2P) overlay on the AS-level underlay. In particular, we capture Gnutella snapshots for four consecutive years, obtain the corresponding AS-level topology snapshots of the Internet and infer the AS-paths associated with each overlay connection. Assuming a simple model of overlay traffic, we analyze the observed load imposed by these Gnutella snapshots on the AS-level underlay using metrics that characterize the load seen on individual AS-paths and by the transit ASes, illustrate the churn among the top transit ASes during this 4-year period, and describe the propagation of traffic within the AS-level hierarchy.

  12. Calculation and evaluation of energy levels and radiative rates for 2s{sup 2}2p{sup 6}-2s2p{sup 6}np and 2s{sup 2}2p{sup 6}-2s{sup 2}2p{sup 5}nd(4{<=}n{<=}20) transitions in Cu XX

    SciTech Connect

    Zhang, Z.R.; Cheng, X.L.; Li, H.F.; Liu, Z.J.; Sun, X.W.

    2012-07-15

    Energy levels, oscillator strengths, and radiative rates have been calculated for 2s{sup 2}2p{sup 6}-2s2p{sup 6}np and 2s{sup 2}2p{sup 6}-2s{sup 2}2p{sup 5}nd transitions with 4{<=}n{<=}20 in Cu XX ions. In the calculations, the Flexible Atomic Code has been used, and systematic analysis and evaluation of the accuracy of the calculated results for the two types of transitions are also given with different indicators. It is shown that the results for the transitions with a 2s hole are greatly improved by using the present method comparing to those from RELAC code. Furthermore, our results show that the energy levels of the 2s2p{sup 6}(n+1)l and 2s{sup 2}2p{sup 5}(n+2)l configurations closely interact with those of the 2s2p{sup 6}np series and it is essential to include the 2s{sup 2}2p{sup 5}(n+1)l configurations in the calculations for the 2s{sup 2}2p{sup 5}nd series.

  13. Trends in adsorbate induced core level shifts

    NASA Astrophysics Data System (ADS)

    Nilsson, Viktor; Van den Bossche, Maxime; Hellman, Anders; Grönbeck, Henrik

    2015-10-01

    Photoelectron core level spectroscopy is commonly used to monitor atomic and molecular adsorption on metal surfaces. As changes in the electron binding energies are convoluted measures with different origins, calculations are often used to facilitate the decoding of experimental signatures. The interpretation could in this sense benefit from knowledge on trends in surface core level shifts for different metals and adsorbates. Here, density functional theory calculations have been used to systematically evaluate core level shifts for (111) and (100) surfaces of 3d, 4d, and 5d transition metals upon CO, H, O and S adsorption. The results reveal trends and several non-intuitive cases. Moreover, the difficulties correlating core level shifts with charging and d-band shifts are underlined.

  14. Influence of chemical bonds on the lifetime of the molecular-field-split 2p levels in H{sub 2}S

    SciTech Connect

    Bueno, Andre Machado; Brito, Arnaldo Naves de; Fink, Reinhold F.; Baessler, Margit; Bjoerneholm, Olle; Burmeister, Florian; Feifel, Raimund; Miron, Catalin; Sorensen, Stacey L.; Wang Honghong; Svensson, Svante

    2003-02-01

    Different lifetime broadenings in molecular-field-split 2p core levels in H{sub 2}S are predicted theoretically and are identified in an experimental investigation of the S 2p Auger electron spectrum. The measurements were performed for the transition to the vibrationally resolved X{sup 1}A{sub 1} ground state of H{sub 2}S{sup 2+}. The lifetimes of the 3e{sub 1/2} and 5e{sub 1/2} levels of the 2p ionized molecule are found to be 64 and 74 meV, respectively. This unambiguous determination of the lifetime difference of 10{+-}1 meV is only possible as the 4e{sub 1/2}{yields}X{sup 1}A{sub 1}(2b{sub 1}{sup -2}) decay channel that overlaps the 5e{sub 1/2}{yields}X{sup 1}A{sub 1}(2b{sub 1}{sup -2}) channel is practically suppressed in Auger decay in H{sub 2}S. The lifetime difference is confirmed by ab initio calculations. A theoretical analysis shows that it results from the mutual orientation of the core hole in the intermediate states and the valence electron density in the sulfur 3p orbitals. Both are strongly influenced by the chemical bond. Thus the observed effect is the direct result of a fundamental property of molecular electronic structure.

  15. Electron Impact Excitation of Autoionizing Levels of Kr and Xe Between the (sup 2)P(sub 3/2) and (sup 2)P(sub 1/2) Ionic Limits

    NASA Technical Reports Server (NTRS)

    LeClair, L. R.; Trajmar, S.

    1996-01-01

    We have observed electrons ejected from autoionizing levels which lie between the (sup 2)P(sub 3/2) and (sup 2)P(sub 1/2) ionic limits for Kr and Xe. Kinetic energy spectra of the ejected electrons were obtained following electron impact excitation of the target gases by using time-of-flight spectroscopy in a crossed beam experiment. Spectral features which correspond to electrons ejected from both odd and even parity autoionizing levels have been identified.

  16. Measurement of the 7p{sup 2}P{sub 3/2} Level Lifetime in Atomic Francium

    SciTech Connect

    Zhao, W.Z.; Simsarian, J.E.; Orozco, L.A.; Shi, W.; Sprouse, G.D.

    1997-06-01

    We present the first measurement of an atomic radiative lifetime in Fr. We use a time-correlated single photon counting technique with a cold sample of {sup 210}Fr atoms in a magneto-optic trap. The results are a precision experimental test of the atomic many-body perturbation theory applied to the heaviest alkali. The lifetime for the 7p {sup 2}P{sub 3/2} level of 21.02(16) ns gives a value for the reduced transition matrix element between the levels 7s {sup 2}S{sub 1/2} {r_arrow} 7p {sup 2}P{sub 3/2} of 5.898(22)a{sub {infinity}} atomic units. {copyright} {ital 1997} {ital The American Physical Society}

  17. Selective recovery of minor trivalent actinides from high level liquid waste by R-BTP/SiO2-P adsorbents

    NASA Astrophysics Data System (ADS)

    Sano, Yuichi; Surugaya, Naoki; Yamamoto, Masahiko

    2010-03-01

    Concerning the selective recovery of minor trivalent actinides (MA(III) = Am(III) and Cm(III)) from high level liquid waste (HLLW) by extraction chromatography, adsorption and elution behaviours of MA(III) and fission products (FP) in a nitric acid media were studied using iHex-BTP/SiO2-P adsorbents, which is expected to show high adsorption affinity for MA(III) even in concentrated HNO3 solution, such as HLLW. In the batch experiments, Pd showed strong adsorption on iHex-BTP/SiO2-P adsorbents under any concentration of HNO3. The MA(III) and heavy Ln(III) (Sm(III), Eu(III) and Gd(III)) were also adsorbed at the condition of high HNO3 concentration, but they showed no adsorption under low HNO3concentration. The separation factor for MA(III)/heavy Ln(III) took the maximum value (over 100) at around 1mol/dm3 HNO3. It was difficult to elute MA(III) or heavy Ln(III) selectively by HNO3 from the iHex-BTP/SiO2-P adsorbents degradated by γ-ray irradiation. The chromatographic separation of real HLLW by an iHex-BTP/SiO2-P column showed that MA(III) could be recovered selectively by adjusting the acidity of the feed solution, i.e. HLLW, to 1mol/dm3 and using H2O as eluant. The adsorption of Pd(II) can be decreased by the addition of appropriate complexing reagents, e.g. DTPA, into HLLW without any effects on the MA(III) adsorption.

  18. Decay processes of the core-excited states 1s2p3 for Be-like systems with Z=8-54

    NASA Astrophysics Data System (ADS)

    Sang, C. C.; Sun, Y.; Hu, F.

    2016-08-01

    On the basis of a fully relativistic multiconfiguration Dirac-Fock method, a systematic study has been carried out for the energies, radiative and non-radiative (Auger) decay processes of the core-excited states 1s2p3 for Be-like ions with Z=8-54. The energies and radiative transition rates are smoothly varying functions of Z. Auger rates do not change significantly with Z as the radiative rates do. Electron correlation effects on the energies and the radiative transition rates are investigated. Good agreement is found between our results and other theoretical data.

  19. Core-level excitation and fragmentation of chlorine dioxide

    NASA Astrophysics Data System (ADS)

    Flesch, R.; Plenge, J.; Rühl, E.

    2006-03-01

    Inner-shell excitation and fragmentation of chlorine dioxide (OClO) in the Cl 2p- and O 1s-excitation regime is reported. The electronic structure of the element-selectively excited radical is studied by X-ray absorption and total cation yields. A comparison of both approaches allows us to estimate the absolute photoionization cross-section and the ionization yield near the Cl 2p- and O 1s-absorption edges. The latter quantity is characteristically enhanced in core-ionization continua. We observe below both core-absorption edges intense core-to-valence-transitions. These are assigned in comparison with related work on core-excited sulfur dioxide. These results give clear evidence that the highest molecular orbital of OClO is half-filled. High-resolution spectra recorded in the Cl 2p-regime show evidence for Rydberg transitions. The extrapolation of the term values of the low-lying Rydberg states allows us to derive the Cl 2p-ionization energy of OClO. Fragmentation of core-excited OClO is reported. Photoelectron-photoion-coincidence (PEPICO) spectra are recorded, indicating that singly and doubly charged fragments are formed. Fission of the doubly and multiply charged OClO leads to singly charged fragments. These are measured by photoion-photoion-coincidence (PIPICO) spectra, where characteristic changes in intensity of the fission channels in the Cl 2p- and O 1s-continuum are observed.

  20. Interaction among Btn1p, Btn2p, and Ist2p reveals potential interplay among the vacuole, amino acid levels, and ion homeostasis in the yeast Saccharomyces cerevisiae.

    PubMed

    Kim, Yoojin; Chattopadhyay, Subrata; Locke, Sarahjane; Pearce, David A

    2005-02-01

    Btn2p, a novel cytosolic coiled-coil protein in Saccharomyces cerevisiae, was previously shown to interact with and to be necessary for the correct localization of Rhb1p, a regulator of arginine uptake, and Yif1p, a Golgi protein. We now report the biochemical and physical interactions of Btn2p with Ist2p, a plasma membrane protein that is thought to have a function in salt tolerance. A deletion in Btn2p (btn2Delta strains) results in a failure to correctly localize Ist2p, and strains lacking Btn2p and Ist2p (btn2Delta ist2Delta strains) are unable to grow in the presence of 0.5 or 1.0 M NaCl. Btn2p was originally identified as being up-regulated in a btn1Delta strain, which lacks the vacuolar-lysosomal membrane protein, Btn1p, and serves as a model for Batten disease. This up-regulation of Btn2p was shown to contribute to the maintenance of a stable vacuolar pH in the btn1Delta strain. Btn1p was subsequently shown to be required for the optimal transport of arginine into the vacuole. Interestingly, btn1Delta ist2Delta strains are also unable to grow in the presence of 0.5 or 1.0 M NaCl, and ist2Delta suppresses the vacuolar arginine transport defect in btn1Delta strains. Although further investigation is required, we speculate that altered vacuolar arginine transport in btn1Delta strains represents a mechanism for maintaining or balancing cellular ion homeostasis. Btn2p interacts with at least three proteins that are seemingly involved in different biological functions in different subcellular locations. Due to these multiple interactions, we conclude that Btn2p may play a regulatory role across the cell in response to alterations in the intracellular environment that may be caused by changes in amino acid levels or pH, a disruption in protein trafficking, or imbalances in ion homeostasis resulting from either genetic or environmental manipulation.

  1. Electrodeposited Co{sub 93.2}P{sub 6.8} nanowire arrays with core-shell microstructure and perpendicular magnetic anisotropy

    SciTech Connect

    Nasirpouri, F.; Peighambari, S. M.; Samardak, A. S. Ognev, A. V.; Sukovatitsina, E. V.; Modin, E. B.; Chebotkevich, L. A.; Komogortsev, S. V.; Bending, S. J.

    2015-05-07

    We demonstrate the formation of an unusual core-shell microstructure in Co{sub 93.2}P{sub 6.8} nanowires electrodeposited by alternating current (ac) in an alumina template. By means of transmission electron microscopy, it is shown that the coaxial-like nanowires contain amorphous and crystalline phases. Analysis of the magnetization data for Co-P alloy nanowires indicates that a ferromagnetic core is surrounded by a weakly ferromagnetic or non-magnetic phase, depending on the phosphor content. The nanowire arrays exhibit an easy axis of magnetization parallel to the wire axis. For this peculiar composition and structure, the coercivity values are 2380 ± 50 and 1260 ± 35 Oe, parallel and perpendicular to the plane directions of magnetization, respectively. This effect is attributed to the core-shell structure making the properties and applications of these nanowires similar to pure cobalt nanowires with an improved perpendicular anisotropy.

  2. A Fast, Robust Matrix-Free Multi-level Preconditioner for Hybrid Marker-In-Cell Q2-P1 Finite Element Discretisations with Applications to Lithospheric Deformation

    NASA Astrophysics Data System (ADS)

    May, D. A.; Le Pourhiet, L.

    2012-12-01

    The use of a mixed finite element formulation to discretise Stokes equations, coupled with a particle based Lagrangian representation of the material lithology is a common numerical technique employed within geodynamics to study large deformation processes. The extension of this methodology to enable high-resolution, three-dimensional simulations still represents a number of significant computational challenges. Of most concern are the high computational memory requirements of the favoured Q2-P1 element, and the development of efficient, 'light-weight' and robust linear and non-linear solvers, which are performant on multi-core, massively parallel computational hardware. Our objective is to develop a 'cheap' and efficient methodology utilizing the mixed element Q2-P1, to study 3D geodynamic processes including subduction, rifting and folding with the inclusion of visco-plastic materials. For this class of problems, careful treatment of all of the aforementioned technical challenges is essential to achieve high resolution simulations. Here, I describe a flexible methodology which aims to rectify all of these issues. The key to the approach is 1) always pose the discrete problem in defect-correction form and 2) utilise a mixture of assembled and matrix-free operations to evaluate the non-linear residual and apply the operators and smoothers required to define the multi-level preconditioner for the Jacobian. The performance characteristics of the matrix-free, multi-level preconditioning strategy is demonstrated by considering several 3D visco-plastic models. The robustness of the preconditioner and non-linear solver with respect to the viscosity contrast and the topology of the viscosity field, together with the parallel scalability will be demonstrated.

  3. Relationships Between Complex Core Level Spectra and Materials Properties

    SciTech Connect

    Nelin, Constance J.; Bagus, Paul S.; Ilton, Eugene S.; Chambers, Scott A.; Kuhlenbeck, Helmut; Freund, Hans-Joachim

    2010-12-01

    The XPS of many oxides are quite complex and there may be several peaks of significant intensity for each subshell. These peaks arise from many-electron effects, which normally are treated with configuration interaction (CI) wavefunctions where static correlation effects are taken into account. It is common to use semiempirical methods to determine the matrix elements of the CI Hamiltonian and there are few rigorous CI calculations where parameters are not adjusted to fit experiment. In contrast, we present, in the present work, theoretical XPS spectra obtained with rigorous CI wavefunctions for CeO2 where the XPS are especially complex; several different core levels are studied. This study uses an embedded CeO8 cluster model to represent bulk CeO2 and the relativistic CI wavefunctions are determined using four-component spinors from Dirac-Fock calculations. In particular, we examine the importance of interatomic many-body effects where there is a transfer of electrons from occupied oxygen 2p orbitals into empty cation orbitals as it is common to ascribe the complex XPS to this effect. We also contrast the importance of many-body charge-transfer effects for the isoelectronic cations of Ce4+ and La3+. The long-range goal of this work is to relate the XPS features to the nature of the chemical bonding in CeO2 and we describe our progress toward this goal.

  4. Structure and behavior of the barringerite Ni end-member, Ni[subscript 2]P, at deep Earth conditions and implications for natural Fe-Ni phosphides in planetary cores

    SciTech Connect

    Dera, P.; Lavina, B.; Borkowski, L.A.; Prakapenka, V.B.; Sutton, S.R.; Rivers, M.L.; Downs, R.T.; Boctor, N.Z.; Prewitt, C.T.

    2009-06-01

    High pressure and high temperature behavior of synthetic Ni{sub 2}P has been studied in a laser-heated diamond anvil cell up to 50 GPA and 2200 K. Incongruent melting associated with formation of pyrite-type NiP{sub 2} and amorphous Ni-P alloy was found at an intermediate pressure range, between 6.5 and 40 GPa. Above GPa, Ni{sub 2}P melts congruently. At room conditions, Ni{sub 2}P has hexagonal C22-type structure, and without heating it remains in this structure to at least 50 GPa. With a bulk modulus K{sub 0} = 201(8) GPa and K' = 4.2(6), Ni{sub 2}P is noticeable less compressible than hcp Fe, as well as all previously described iron phosphides, and its presence in the Earth core would favorable lower the core density. In contrast to Fe{sub 2}P, the c/a ratio in Ni{sub 2}P decreases on compression because of the lack of ferromagnetic interaction along the c direction. Lack of the C22{yields}C23 transition in the Ni{sub 2}P rules out a stabilizing effect of Ni on the orthorhombic phase of natural (Fe{sub 1-x}Ni{sub x}){sub 2}P allabogdanite.

  5. Radiative lifetimes of the 2s2p2(4P) metastable levels of N III

    NASA Technical Reports Server (NTRS)

    Fang, Z.; Kwong, Victor H. S.; Parkinson, W. H.

    1993-01-01

    The radiative decay rates of N III 175 nm intersystem lines were measured in the laboratory by recording the time dependence of photon intensities emitted as the 2s2p2(4P) metastable term of N(2+) ions decay to the 2s22p(2P0) ground term. A cylindrical radio frequency ion trap was used to store the electron impact-produced N(2+) ions. The radiative decay signals were analyzed by multiexponential least-squares fits to the data. The measured radiative decay rates to the ground term are 1019(+/- 64)/s for 4P sub 1/2, 74.5(+/- 5.4)/s for 4P sub 3/2, and 308( +/- 22)/s for 4P sub 5/2. Comparisons of the measured values with theoretical values are presented.

  6. Spin polarization and magnetic dichroism in core-level photoemission from ferromagnets

    SciTech Connect

    Menchero, J G

    1997-05-01

    In this thesis we present a theoretical investigation of angle- and spin-resolved core-level photoemission from ferromagnetic Fe and Ni. We also consider magneto-dichroic effects due to reversal of the photon helicity or reversal of the sample magnetization direction. In chapter 1, we provide a brief outline of the history of photoemission, and show how it has played an important role in the development of modern physics. We then review the basic elements of the theory of core-level photoemission, and discuss the validity of the some of the commonly-used approximations. In chapter 2, we present a one-electron theory to calculate spin- and angle-resolved photoemission spectra for an arbitrary photon polarization. The Hamiltonian includes both spin-orbit and exchange interactions. As test cases for the theory, we calculate the spin polarization and magnetic dichroism for the Fe 2p core level, and find that agreement with experiment is very good.

  7. Health Occupations Orientation Level Core Curriculum.

    ERIC Educational Resources Information Center

    Boyum, Paula G.; And Others

    This guide is intended for use in teaching a secondary-level orientation course in health occupations that is designed to prepare students for employment in all types of health care facilities and for entry into postsecondary programs. The guide is divided into two parts. The first part consists of a teacher's guide and 11 instructional units…

  8. Hyperfine splitting of the 2s1/2 and 2p1/2 levels in Li- and be-like ions of (59)(141) Pr.

    PubMed

    Beiersdorfer, P; Träbert, E; Brown, G V; Clementson, J; Thorn, D B; Chen, M H; Cheng, K T; Sapirstein, J

    2014-06-13

    High-resolution spectroscopy of the 2s(1/2)-2p(1/2) transition in the extreme ultraviolet region is shown to resolve the level splitting induced by the nuclear magnetic field of both the 2s(1/2) and the 2p(1/2) levels in lithiumlike (141)Pr(56+) and of the 2s(1/2)2p(1/2) (3)P(1) level in berylliumlike (141)Pr(55+). The (141)Pr ions are an ideal test of this measurement approach because their energy levels are known well from first principles and are unaffected by small energy contributions from QED and nuclear magnetization effects. The accuracy attained in the measured 196.5 ± 1.2 meV 2s(1/2) splitting is more than an order of magnitude better than that achieved before using crystal spectroscopy of the 2s(1/2)-2p(3/2) x-ray transition and at the level needed to implement a proposed scheme for disentangling the contributions from QED and nuclear magnetization effects in higher-Z ions, such as (209)Bi.

  9. Ab-initio multi-configuration Dirac-Hartree-Fock calculation on the lifetimes of levels in 2p53s configuration of neutral neon

    NASA Astrophysics Data System (ADS)

    Li, J. G.; Verdebout, S.; Godefroid, M.

    2012-11-01

    Large-scale calculations have been performed using the GRASP2K package to accurately determine the lifetime of levels in 2p53s configuration of neutral neon. In particular, we calculated the hyperfine-induced transition rates from two metastable levels 3P20,0 to the ground state for odd Ne isotopes. It was found that hyperfine interactions drastically quench the lifetime of these two levels.

  10. Language Arts Core Curriculum: Secondary Core Curriculum Standards. Levels 7-12, Language Arts (Drama). Revised.

    ERIC Educational Resources Information Center

    Utah State Board of Education, Salt Lake City.

    This curriculum guide presents the core standards and objectives for level 7-12 language arts instruction in Utah. The curriculum guide begins with a statement of the elementary and secondary school program of studies and high school graduation requirements. After a brief statement on the importance of language arts and core curriculum standards…

  11. Physics of the Be(0001) surface core-level spectrum

    SciTech Connect

    Feibelman, P.J.; Stumpf, R. )

    1994-12-15

    First-principles calculations for slabs as many as 13 layers thick show that the three surface core-level features observed on Be(0001) correspond to core-electron ionizations in its three outermost atomic layers. The calculations also imply that the experimental peak identified with core ionization in the bulk is a composite; theoretical core-ionization potentials for the fourth and deeper layers differ by as much as 90 meV. The sign and surprisingly large magnitudes of the Be(0001) surface core-level shifts (SCLS's) are attributed to unusually large surface-state contributions to the three outer layers' local densities of states. Both initial- and final-state effects are substantial in the SCLS's, and their contributions are additive.

  12. Core level excitations—A fingerprint of structural and electronic properties of epitaxial silicene

    SciTech Connect

    Friedlein, R. Fleurence, A.; Aoyagi, K.; Yamada-Takamura, Y.; Jong, M. P. de; Van Bui, H.; Wiggers, F. B.; Yoshimoto, S.; Koitaya, T.; Shimizu, S.; Noritake, H.; Mukai, K.; Yoshinobu, J.

    2014-05-14

    From the analysis of high-resolution Si 2p photoelectron and near-edge x-ray absorption fine structure (NEXAFS) spectra, we show that core level excitations of epitaxial silicene on ZrB{sub 2}(0001) thin films are characteristically different from those of sp{sup 3}-hybridized silicon. In particular, it is revealed that the lower Si 2p binding energies and the low onset in the NEXAFS spectra as well as the occurrence of satellite features in the core level spectra are attributed to the screening by low-energy valence electrons and interband transitions between π bands, respectively. The analysis of observed Si 2p intensities related to chemically distinct Si atoms indicates the presence of at least one previously unidentified component. The presence of this component suggests that the observation of stress-related stripe domains in scanning tunnelling microscopy images is intrinsically linked to the relaxation of Si atoms away from energetically unfavourable positions.

  13. Measurement of the metastable lifetime for the 2s^2 2p^2 ^1So level in O^2+

    NASA Technical Reports Server (NTRS)

    Smith, S. J.; Cadez, I.; Chutjian, A.; Niimura, M.

    2004-01-01

    The radiative lifetime of the 1S0 level was found to be 540 +/- 27 ms. This is in good agreement with a previous measurement and with a number of theoretical calculations. Metastable lifetimes, when combined with collisional excitation rates, can provide a diagnostic for electron density Ne in a stellar or solar plasma.

  14. Idaho Marketing Education Core Curriculum. Career Sustaining Level, Specialist Level, Supervisory Level, Entrepreneurial Level.

    ERIC Educational Resources Information Center

    Miller, Linda Wise; Winn, Richard

    This document contains Idaho's marketing education (ME) core curriculum. Presented first are a list of 22 ME strategies that are aligned with the Idaho State Division of Vocational-Technical Education's strategic plan and a chart detailing the career pathways of ME in Idaho (arts and communication, business and management, health services, human…

  15. Exploring the core level shift origin of sulfur and thiolates on Pd(111) surfaces.

    PubMed

    Salvarezza, Roberto Carlos; Carro, Pilar

    2015-10-01

    Thiol molecules on planar metal surfaces are widely used for building sensing and electronic devices and also as capping agents to protect and to control the size and shape of nanoparticles. In the case of Pd the thiol molecules exhibit a complex behavior because C-S bond scission is possible, resulting in a significant amount of co-adsorbed S. Therefore identification of these species on Pd is a key point for many applications, a task that is usually achieved by XPS. Here we show, from DFT calculations, that the core level shift (CLS) of the S 2p binding energy (BE) of thiol and sulfur on different thiol-Pd(111) surface models strongly depends on the adsorbed or subsurface state of sulfur atoms. Our results reflect the complexity of S 2p BE behavior and contribute to understanding and reanalyzing the experimental data of thiolated Pd surfaces.

  16. District Level Leadership: Core Leadership Practices for Sustainable Change

    ERIC Educational Resources Information Center

    Feagan, Roger W.; Kupka, Cynthia J.; Laubenstein, Michelle M.; Miller, Dana L.

    2009-01-01

    This report describes the findings of a doctoral team project regarding core leadership practices that support sustainable academic change. The project team reviewed literature related to sustainable change, reform models, and leadership. The empirical research regarding the relationship between district level leadership practices that contribute…

  17. Delivering Core Engineering Concepts to Secondary Level Students

    ERIC Educational Resources Information Center

    Merrill, Chris; Custer, Rodney L.; Daugherty, Jenny; Westrick, Martin; Zeng, Yong

    2008-01-01

    Through the efforts of National Center for Engineering and Technology Education (NCETE), three core engineering concepts within the realm of engineering design have emerged as crucial areas of need within secondary level technology education. These concepts are constraints, optimization, and predictive analysis (COPA). COPA appears to be at the…

  18. Facile aqueous synthesis and electromagnetic properties of novel 3D urchin-like glass/Ni-Ni(3)P/Co(2)P(2)O(7) core/shell/shell composite hollow structures.

    PubMed

    An, Zhenguo; Zhang, Jingjie; Pan, Shunlong

    2010-04-14

    Novel 3D urchin-like glass/Ni-Ni(3)P/Co(2)P(2)O(7) core/shell/shell composite hollow structures are fabricated for the first time by controlled stepwise assembly of granular Ni-Ni(3)P alloy and ribbon-like Co(2)P(2)O(7) nanocrystals on hollow glass spheres in aqueous solutions at mild conditions. It is found that the shell structure and the overall morphology of the products can be tailored by properly tuning the annealing temperature. The as-obtained composite core/shell/shell products possess low density (ca. 1.18 g cm(-3)) and shape-dependent magnetic and microwave absorbing properties, and thus may have some promising applications in the fields of low-density magnetic materials, microwave absorbers, etc. Based on a series of contrast experiments, the probable formation mechanism of the core/shell/shell hierarchical structures is proposed. This work provides an additional strategy to prepare core/shell composite spheres with tailored shell morphology and electromagnetic properties. PMID:20379530

  19. Core-level shifts in fcc random alloys: A first-principles approach

    NASA Astrophysics Data System (ADS)

    Olovsson, W.; Göransson, C.; Pourovskii, L. V.; Johansson, B.; Abrikosov, I. A.

    2005-08-01

    First-principles theoretical calculations of the core-level binding-energy shift (CLS) for eight binary face-centered-cubic (fcc) disordered alloys, CuPd, AgPd, CuNi, NiPd, CuAu, PdAu, CuPt, and NiPt, are carried out within density-functional theory (DFT) using the coherent potential approximation. The shifts of the Cu and Ni 2p3/2 , Ag and Pd 3d5/2 , and Pt and Au 4f7/2 core levels are calculated according to the complete screening picture, which includes both initial-state (core-electron energy eigenvalue) and final-state (core-hole screening) effects in the same scheme. The results are compared with available experimental data, and the agreement is shown to be good. The CLSs are analyzed in terms of initial- and final-state effects. We also compare the complete screening picture with the CLS obtained by the transition-state method, and find very good agreement between these two alternative approaches for the calculations within the DFT. In addition the sensitivity of the CLS to relativistic and magnetic effects is studied.

  20. Relativistically prolonged lifetime of the 2s2p 3P0 level of zero nuclear-spin beryllium-like ions

    NASA Astrophysics Data System (ADS)

    Fritzsche, S.; Surzhykov, A.; Volotka, A.

    2015-10-01

    The E1M1 transition rate of the 2s2p{ }3{P}0\\to 2{s}2{ }1{S}0 line in beryllium-like ions has been calculated within the framework of relativistic second-order perturbation theory. Both multiconfiguration and quantum-electrodynamical computations have been carried out independently to better understand and test for all major electron-electron correlation contributions in the representation of the initial, intermediate and final states. By comparing the results from these methods, which agree well for all ions along the beryllium isoelectronic sequence, the lifetime of the metastable 2s2p 3P0 level is found to be longer by about 2-3 orders of magnitude for all medium and heavy elements than was estimated previously. This makes the 3P0 level of beryllium-like ions to one of the longest living (low-lying) electronic excitations of a tightly bound system with potential applications for atomic clocks and in astro physics and plasma physics.

  1. Study on separation of platinum group metals from high level liquid waste using macroporous (MOTDGA-TOA)/SiO{sub 2}-P silica-based absorbent

    SciTech Connect

    Ito, Tatsuya; Kim, Seong-Yun; Xu, Yuanlai; Hitomi, Keitaro; Ishii, Keizo; Nagaishi, Ryuji; Kimura, Takaumi

    2013-07-01

    The recovery of platinum group metals (PGMs) from high level liquid waste (HLLW) by macroporous silica-based adsorbent, (MOTDGA-TOA)/SiO{sub 2}-P has been developed by impregnating two extractants of N,N'-dimethyl-N,N'-di-n-octyl-thio-diglycolamide (MOTDGA) and tri-n-octylamine (TOA) into a silica/polymer composite support (SiO{sub 2}-P). The adsorption of Ru(III), Rh(III) and Pd(II) have been investigated in simulated HLLW by batch method. The adsorbent has shown good uptake property for Pd(II). In addition, the combined use of MOTDGA and TOA improved the adsorption of Ru(III) and Rh(III) better than the individual use of them. The usability of adsorbent in radiation fields was further confirmed by irradiation experiments. The adsorbent remained to have the uptake capability for PGMs over the absorbed dose of 100 kGy, corresponding with one really adsorbed by the adsorbent, and showed good retention capability for Pd(II) even at the absorbed dose of 800 kGy. The chromatographic separation of metal ions was demonstrated with the adsorbent packed column, there is no influence of Re(VII) (instead of Tc) on the excellent separation behavior of Pd(II). (authors)

  2. Gamma thermometer based reactor core liquid level detector

    SciTech Connect

    Burns, T.J.

    1983-09-20

    A system is provided which employs a modified gamma thermometer for determining the liquid coolant level within a nuclear reactor core. The gamma thermometer which normally is employed to monitor local core heat generation rate (reactor power), is midified by thermocouple junctions and leads to obtain an unambiguous indication of the presence or absence of coolant liquid at the gamma thermometer location. A signal processor generates a signal based on the thermometer surface heat transfer coefficient by comparing the signals from the thermocouples at the thermometer location. The generated signal is a direct indication of loss of coolant due to the change in surface heat transfer when coolant liquid drops below the thermometer location. The loss of coolant indication is independent of reactor power at the thermometer location. Further, the same thermometer may still be used for the normal power monitoring function.

  3. Gamma thermometer based reactor core liquid level detector

    DOEpatents

    Burns, Thomas J.

    1983-01-01

    A system is provided which employs a modified gamma thermometer for determining the liquid coolant level within a nuclear reactor core. The gamma thermometer which normally is employed to monitor local core heat generation rate (reactor power), is modified by thermocouple junctions and leads to obtain an unambiguous indication of the presence or absence of coolant liquid at the gamma thermometer location. A signal processor generates a signal based on the thermometer surface heat transfer coefficient by comparing the signals from the thermocouples at the thermometer location. The generated signal is a direct indication of loss of coolant due to the change in surface heat transfer when coolant liquid drops below the thermometer location. The loss of coolant indication is independent of reactor power at the thermometer location. Further, the same thermometer may still be used for the normal power monitoring function.

  4. Disparity between beta-core levels in pregnancy urine and serum: implications for the origin of urinary beta-core.

    PubMed

    Wehmann, R E; Blithe, D L; Akar, A H; Nisula, B C

    1990-02-01

    We used a highly purified preparation of the naturally occurring core fragment of hCG beta (beta-core) and a new RIA for beta-core to investigate the concentrations and behavior of beta-core in serum and urine. We collected serum and 24-h urine specimens from healthy pregnant women during the first trimester of pregnancy. The concentrations of beta-core in serum were determined by analysis of fractions eluted from Sephadex G-100. Serum concentrations of beta-core immunoreactivity were very low (0.13-1.25 micrograms/L), while large amounts of beta-core were excreted in urine during pregnancy (as much as 4-5 mg/day). Interference with measurement by serum factors did not account for the low levels of beta-core immunoreactivity in pregnancy serum. Based on the known urinary clearance rate of beta-core in healthy nonpregnant subjects, we calculated that urinary clearance of serum beta-core accounts for only about 1% of the beta-core in pregnancy urine. We conclude that during pregnancy, the concentrations of beta-core in plasma are measurable, but extremely low, and that most of the beta-core in urine is derived by mechanisms other than urinary clearance of serum beta-core; most likely, these mechanisms involve nephrogenous production of beta-core from precursor molecules such as hCG and hCG beta.

  5. Core level binding energies of functionalized and defective graphene.

    PubMed

    Susi, Toma; Kaukonen, Markus; Havu, Paula; Ljungberg, Mathias P; Ayala, Paola; Kauppinen, Esko I

    2014-01-01

    X-ray photoelectron spectroscopy (XPS) is a widely used tool for studying the chemical composition of materials and it is a standard technique in surface science and technology. XPS is particularly useful for characterizing nanostructures such as carbon nanomaterials due to their reduced dimensionality. In order to assign the measured binding energies to specific bonding environments, reference energy values need to be known. Experimental measurements of the core level signals of the elements present in novel materials such as graphene have often been compared to values measured for molecules, or calculated for finite clusters. Here we have calculated core level binding energies for variously functionalized or defected graphene by delta Kohn-Sham total energy differences in the real-space grid-based projector-augmented wave density functional theory code (GPAW). To accurately model extended systems, we applied periodic boundary conditions in large unit cells to avoid computational artifacts. In select cases, we compared the results to all-electron calculations using an ab initio molecular simulations (FHI-aims) code. We calculated the carbon and oxygen 1s core level binding energies for oxygen and hydrogen functionalities such as graphane-like hydrogenation, and epoxide, hydroxide and carboxylic functional groups. In all cases, we considered binding energy contributions arising from carbon atoms up to the third nearest neighbor from the functional group, and plotted C 1s line shapes by using experimentally realistic broadenings. Furthermore, we simulated the simplest atomic defects, namely single and double vacancies and the Stone-Thrower-Wales defect. Finally, we studied modifications of a reactive single vacancy with O and H functionalities, and compared the calculated values to data found in the literature.

  6. Multiple-Level Regulation of 2,4-Diacetylphloroglucinol Production by the Sigma Regulator PsrA in Pseudomonas fluorescens 2P24

    PubMed Central

    Wu, Xiaogang; Liu, Jiucheng; Zhang, Wei; Zhang, Liqun

    2012-01-01

    Background Pseudomonas fluorescens 2P24 is a rhizospheric bacterium that aggressively colonizes the plant roots. It produces the antibiotic 2,4-diacetylphoroglucinol (2,4-DAPG), which contributes to the protection of various crop plants against soil borne diseases caused by bacterial and fungal pathogens. The biosynthesis of 2,4-DAPG is regulated at the transcriptional level in the expression of the phlACBD operon as well as at the posttranscriptional level by the Gac/Rsm signal transduction pathway. However, the detailed mechanism of such regulation is not clear. Methodology/Principal Findings In this study, we identified a binding site for the sigma regulator PsrA in the promoter region of the phlA gene. Electrophoretic mobility shift experiments revealed direct and specific binding of PsrA to the phlA promoter region. Consistent with the fact that its binding site locates within the promoter region of phlA, PsrA negatively regulates phlA expression, and its inactivation led to significant increase in 2,4-DAPG production. Interestingly, PsrA also activates the expression of the sigma factor RpoS, which negatively regulates 2,4-DAPG production by inducing the expression of the RNA-binding protein RsmA. Conclusions/Significance These results suggest that PsrA is an important regulator that modulates 2,4-DAPG biosynthesis at both transcriptional and posttranscriptional levels. PMID:23209661

  7. Core-level positive-ion and negative-ion fragmentation of gaseous and condensed HCCl3 using synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Lu, K. T.; Chen, J. M.; Lee, J. M.; Haw, S. C.; Liang, Y. C.; Deng, M. J.

    2011-07-01

    We investigated the dissociation dynamics of positive-ion and negative-ion fragments of gaseous and condensed HCCl3 following photoexcitation of Cl 2p electrons to various resonances. Based on ab initio calculations at levels HF/cc-pVTZ and QCISD/6-311G*, the first doublet structures in Cl L-edge x-ray absorption spectrum of HCCl3 are assigned to transitions from the Cl (2P3/2,1/2) initial states to the 10a1* orbitals. The Cl 2p → 10a1* excitation of HCCl3 induces a significant enhancement of the Cl+ desorption yield in the condensed phase and a small increase in the HCCl+ yield in the gaseous phase. Based on the resonant photoemission of condensed HCCl3, excitations of Cl 2p electrons to valence orbitals decay predominantly via spectator Auger transitions. The kinetic energy distributions of Cl+ ion via the Cl 2p → 10a1* excitation are shifted to higher energy ˜0.2 eV and ˜0.1 eV relative to those via the Cl 2p → 10e* excitation and Cl 2p → shape resonance excitation, respectively. The enhancement of the yields of ionic fragments at specific core-excited resonance states is assisted by a strongly repulsive surface that is directly related to the spectator electrons localized in the antibonding orbitals. The Cl- anion is significantly reinforced in the vicinity of Cl 2p ionization threshold of gaseous HCCl3, mediated by photoelectron recapture through post-collision interaction.

  8. Alkyl-terminated Si(111) surfaces: A high-resolution, core level photoelectron spectroscopy study

    SciTech Connect

    Terry, J.; Linford, M.R.; Wigren, C.; Cao, R.; Pianetta, P.; Chidsey, C.E.

    1999-01-01

    The bonding of alkyl monolayers to Si(111) surfaces has been studied with high-resolution core level photoelectron spectroscopy (PES). Two very different wet-chemical methods have been used to prepare the alkyl monolayers: (i) Olefin insertion into the H{endash}Si bond of the H{endash}Si(111) surface, and (ii) replacement of Cl on the Cl{endash}Si(111) surface by an alkyl group from an alkyllithium reagent. In both cases, PES has revealed a C 1s component shifted to lower binding energy and a Si 2p component shifted to higher binding energy. Both components are attributed to the presence of a C{endash}Si bond at the interface. Along with photoelectron diffraction data [Appl. Phys. Lett. {bold 71}, 1056, (1997)], these data are used to show that these two synthetic methods can be used to functionalize the Si(111) surface. {copyright} {ital 1999 American Institute of Physics.}

  9. Visual Arts, Levels 7-12. Secondary Core Curriculum Standards.

    ERIC Educational Resources Information Center

    Utah State Office of Education, Salt Lake City.

    This Utah state curriculum guide calls for one 7-8th grade course (0.5 unit) of visual arts education to fulfill the visual arts Component requirement of the core curriculum. Up to three visual arts courses may be taken at the 9-12th grades as fulfillment of the 1.5 core art units required. Core options include courses in ceramics, jewelry,…

  10. Science, Levels 7-12. Secondary Core Curriculum Standards.

    ERIC Educational Resources Information Center

    Utah State Board of Education, Salt Lake City. Div. of Curriculum and Instruction.

    This document presents the core science curriculum standards which must be completed by all students as a requisite for graduation from Utah's secondary schools. Contained within are the elementary and secondary school program of studies and high school graduation requirements. Each course entry for grades 7-12 contains: course title, unit of…

  11. Core-level attosecond transient absorption spectroscopy of laser-dressed solid films of Si and Zr

    NASA Astrophysics Data System (ADS)

    Seres, Enikoe; Seres, Jozsef; Serrat, Carles; Namba, Shinichi

    2016-10-01

    We investigated experimentally as well as theoretically the ultrafast response of the wave function of the conduction band (CB) of Si and Zr to a near-infrared laser field using extreme ultraviolet (XUV) absorption spectroscopy in the spectral range of 80-220 eV. The measured dynamics of the XUV transmission demonstrates that the wave function of the CB follows the electric field of the dressing laser pulse. In these terms, laser dressing was earlier mainly studied on gases. Measurements with two-femtosecond and 200-attosecond temporal steps were performed in the vicinity of the Si L2 ,3 edge near 100 eV, the Si L1 edge near 150 eV, and the Zr M4 ,5 edge near 180 eV. The observed changes were dependent on the core states being excited by the XUV probe pulse. At the 2 p to CB transitions of Si, the XUV transmission increased via the effect of the dressing laser pulse, while at the 2 s to CB transition of Si and the 3 d to CB transition of Zr, the XUV transmission decreased. Furthermore, beats between the transition from 2 p1 /2 and 2 p3 /2 levels of Si and from 3 d3 /2 and 3 d5 /2 levels of Zr were observed with 20.7 fs and 3.6 fs periods.

  12. Core level photoelectron spectroscopy on the lanthanide-induced hydrolysis of DNA

    NASA Astrophysics Data System (ADS)

    Shigekawa, Hidemi; Ikawa, Hiroyuki; Yoshizaki, Ryozo; Iijima, Yoshitoki; Sumaoka, Jun; Komiyama, Makoto

    1996-03-01

    The electronic structures of the complexes of diphenyl phosphate (DPP), a model compound of DNA, with lanthanide ions have been investigated to shed light on the mechanism of the cerium (IV)-induced nonenzymatic hydrolysis of DNA. Binding energies of the P 2p core level of DPP were 134.2 eV for the complexes with La(III), Eu(III), and Lu(III), and was 134.4 eV for the Ce(IV) complex, when the metal/DPP molar ratio was 1:1. When the molar ratio was increased, only Ce(IV), the most active metal ion for DNA hydrolysis, showed a chemical shift of ˜0.5 eV toward the higher binding energy region. The chemical shift of ˜0.5 eV toward the higher binding energy region. The chemical shift was due to the systematic increase in the intensity of the higher binding energy component. The observed change in the electronic structure of the DPP-Ce(IV) complex may be related to the superb ability of Ce(IV) for the hydrolysis of DNA.

  13. Spin-Orbit Effects in Spin-Resolved L2,3 Core Level Photoemission of 3d Ferromagnetic Thin Films

    SciTech Connect

    Komesu, T; Waddill, G D; Yu, S W; Butterfield, M; Tobin, J G

    2007-10-02

    We present spin-resolved 2p core level photoemission for the 3d transition metal films of Fe and Co grown on Cu(100). We observe clear spin asymmetry in the main 2p core level photoemission peaks of Fe and Co films consistent with trends in the bulk magnetic moments. The spin polarization can be strongly enhanced, by variation of the experimental geometry, when the photoemission is undertaken with circularly polarized light, indicating that spin-orbit interaction can have a profound in spin polarized photoemission. Further spin polarized photoemission studies using variable circularly polarized light at high photon energies, high flux are indicated, underscoring the value of synchrotron measurements at facilities with increased beam stability.

  14. Alkaline Earth Core Level Photoemission Spectroscopy of High-Temperature Superconductors

    NASA Technical Reports Server (NTRS)

    Vasquez, R.

    1993-01-01

    This paper examines photoemission measurements of the alkaline Earth core levels of high-temperature superconductors and related materials, models that seek to explain the large negative shifts observed relative to the corresponding alkaline Earth metals, and the effect of lattice site disorder on the core level spectra and the presence or absence of intrinsic surface peaks.

  15. Lifetime for Li-like Ti 1s2s2p {sup 4}P{sub 5/2}{sup o} level using a mode of beam-two-foil experiments

    SciTech Connect

    Nandi, T.; Ahmad, Nissar; Wani, A.A.

    2005-08-15

    The option of varying thickness of the fixed foil in the beam-two-foil technique has been incorporated in our experimental setup. It gives an opportunity to explore a new mode of this technique. In the current study, we have investigated the lifetime of the 1s2s2p {sup 4}P{sub 5/2}{sup o} level in Li-like titanium using this technique. The data showed a dependence of foil thickness of the fixed foil on the interactions of levels produced in the first foil. Average lifetime obtained for the Li-like titanium 1s2s2p {sup 4}P{sub 5/2}{sup o} level (200{+-}12 ps) is compared very well with the earlier theoretical and experimental values.

  16. An investigation of core liquid level depression in small break loss-of-coolant accidents

    SciTech Connect

    Schultz, R.R.; Watkins, J.C. ); Motley, F.E.; Stumpf, H. ); Chen, Y.S. . Div. of Systems Research)

    1991-08-01

    Core liquid level depression can result in partial core dryout and heatup early in a small break loss-of-coolant accident (SBLOCA) transient. Such behavior occurs when steam, trapped in the upper regions of the reactor primary system (between the loop seal and the core inventory), moves coolant out of the core region and uncovers the rod upper elevations. The net result is core liquid level depression. Core liquid level depression and subsequent core heatups are investigated using subscale data from the ROSA-IV Program's 1/48-scale Large Scale Test Facility (LSTF) and the 1/1705-scale Semiscale facility. Both facilities are Westinghouse-type, four-loop, pressurized water reactor simulators. The depression phenomena and factors which influence the minimum core level are described and illustrated using examples from the data. Analyses of the subject experiments, conducted using the TRAC-PF1/MOD1 (Version 12.7) thermal-hydraulic code, are also described and summarized. Finally, the response of a typical Westinghouse four-loop plant (RESAR-3S) was calculated to qualitatively study coal liquid level depression in a full-scale system. 31 refs., 37 figs., 6 tabs.

  17. Reliable measurement of the Li-like {sub 22}{sup 48}Ti 1s2s2p {sup 4}P{sub 5/2}{sup o} level lifetime by beam-foil and beam-two-foil experiments

    SciTech Connect

    Nandi, T.; Ahmad, Nissar; Wani, A. A.; Marketos, P.

    2006-03-15

    We have determined the lifetime of the Li-like {sub 22}{sup 48}Ti 1s2s2p {sup 4}P{sub 5/2}{sup o} level (210.5{+-}13.5 ps) using data from its x-ray decay channel through beam single- and two-foil experiments, coupled to a multicomponent iterative growth and decay analysis. Theoretical lifetime estimates for this zero-nuclear-spin ion lies within the uncertainty range of our experimental results, indicating that blending contributions to this level from the He-like 1s2p {sup 3}P{sub 2}{sup o} and 1s2s {sup 3}S{sub 1} levels are eliminated within the current approach. A previously reported discrepancy between experimental and theoretical 1s2s2p {sup 4}P{sub 5/2}{sup o} level lifetimes in {sub 23}{sup 51}V may, as a result, be attributed to hyperfine quenching.

  18. Core-Substituted Naphthalenediimides: LUMO Levels Revisited, in Comparison with Preylenediimides with Sulfur Redox Switches in the Core.

    PubMed

    Miros, François N; Matile, Stefan

    2016-06-01

    Core-substituted naphthalenediimides (NDIs) attract increasing attention to bind, transport, and transform electrons, anions, anionic intermediates, and anionic transition states, and to shine as most colorful rainbow fluorophores. The energy level of their lowest unoccupied molecular orbital (LUMO) is decisive for many of these applications. Here, differential pulse voltammetry (DPV) measurements for a consistent series of NDIs are reported to extract exact LUMO levels under identical conditions. The influence of primary and secondary substituents in the core and on the primary imides is compared with general trends for the reliable prediction of LUMO levels in functional systems. Emphasis is on sulfur redox switches in the NDI core because of their frequent use as isostructural probes for π acidity. The same sulfur redox chemistry is expanded to perylenediimides (PDIs), and LUMO engineering is discussed in a broader context, including also fullerenes, aminonaphthalimides (ANIs), and aminoperyleneimides (APIs). The result is a comprehensive reference table that graphically maps out the LUMO space covered by the leading families of electronaccepting aromatics. This graphical summary of general trends in the π-acidic space is expected to be both inspiring and quite useful in practice. PMID:27551658

  19. A Cul-3-BTB ubiquitylation pathway regulates junctional levels and asymmetry of core planar polarity proteins

    PubMed Central

    Strutt, Helen; Searle, Elizabeth; Thomas-MacArthur, Victoria; Brookfield, Rosalind; Strutt, David

    2013-01-01

    The asymmetric localisation of core planar polarity proteins at apicolateral junctions is required to specify cell polarity in the plane of epithelia. This asymmetric distribution of the core proteins is proposed to require amplification of an initial asymmetry by feedback loops. In addition, generation of asymmetry appears to require the regulation of core protein levels, but the importance of such regulation and the underlying mechanisms is unknown. Here we show that ubiquitylation acts through more than one mechanism to control core protein levels in Drosophila, and that without this regulation cellular asymmetry is compromised. Levels of Dishevelled at junctions are regulated by a Cullin-3-Diablo/Kelch ubiquitin ligase complex, the activity of which is most likely controlled by neddylation. Furthermore, activity of the deubiquitylating enzyme Fat facets is required to maintain Flamingo levels at junctions. Notably, ubiquitylation does not alter the total cellular levels of Dishevelled or Flamingo, but only that of the junctional population. When junctional core protein levels are either increased or decreased by disruption of the ubiquitylation machinery, their asymmetric localisation is reduced and this leads to disruption of planar polarity at the tissue level. Loss of asymmetry by altered core protein levels can be explained by reference to feedback models for amplification of asymmetry. PMID:23487316

  20. Nuclear reactor with low-level core coolant intake

    DOEpatents

    Challberg, Roy C.; Townsend, Harold E.

    1993-01-01

    A natural-circulation boiling-water reactor has skirts extending downward from control rod guide tubes to about 10 centimeters from the reactor vessel bottom. The skirts define annular channels about control rod drive housings that extend through the reactor vessel bottom. Recirculating water is forced in through the low-level entrances to these channels, sweeping bottom water into the channels in the process. The sweeping action prevents cooler water from accumulating at the bottom. This in turn minimizes thermal shock to bottom-dwelling components as would occur when accumulated cool water is swept away and suddenly replaced by warmer water.

  1. A first-principles core-level XPS study on the boron impurities in germanium crystal

    SciTech Connect

    Yamauchi, Jun; Yoshimoto, Yoshihide; Suwa, Yuji

    2013-12-04

    We systematically investigated the x-ray photoelectron spectroscopy (XPS) core-level shifts and formation energies of boron defects in germanium crystals and compared the results to those in silicon crystals. Both for XPS core-level shifts and formation energies, relationship between defects in Si and Ge is roughly linear. From the similarity in the formation energy, it is expected that the exotic clusters like icosahedral B12 exist in Ge as well as in Si.

  2. Effects of valence-valence, core-valence and core-core correlations on the fine-structure energy levels in Zn-like ions

    NASA Astrophysics Data System (ADS)

    Hu, F.; Jiang, G.; Yang, J. M.; Wang, C. K.; Zhao, X. F.; Hao, L. H.

    2011-01-01

    We report on large ab initio calculation for the 4s^2- 4s4p transitions in the Zinc-like sequence, using the multi-configuration Dirac-Hartree-Fock method. Results for fine-structure energy levels, the wavelengths, transition rates and lifetimes between Z = 70 (Yb) and Z= 92 (U) are presented and compared with other theories and experiments. The calculated values including core-valence correlation are found to be similar and to compare very well with other theories and experiments values. We believe that our extensive calculated values can guide experimentalists in identifying the fine-structure levels in their future work.

  3. Skin-depth lattice strain, core-level trap depression and valence charge polarization of Al surfaces

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Bo, Maolin; Liu, Yonghui; Guo, Yongling; Wang, Haibin; Yue, Jian; Huang, Yongli

    2016-01-01

    Clarifying the origin for surface core-level shift (SCLS) and gaining quantitative information regarding the coordination-resolved local strain, binding energy (BE) shift and cohesive energy change have been a challenge. Here, we show that a combination of the bond order-length-strength (BOLS) premise, X-ray photoelectron spectroscopy (XPS) and the ab initio density functional theory (DFT) calculations of aluminum (Al) 2p3/2 energy shift of Al surfaces has enabled us to derive such information, namely, (i) the 2p3/2 energy of an isolated Al atom (72.146 ± 0.003eV) and its bulk shift (0.499 eV); (ii) the skin lattice contracts by up to 12.5% and the BE density increases by 70%; and (iii) the cohesive energy drops up to 38%. It is affirmed that the shorter and stronger bonds between under-coordinated atoms provide a perturbation to the Hamiltonian and hence lead to the local strain, quantum entrapment and valence charge polarization. Findings should help in understanding the phenomena of surface pre-melting and skin-high elasticity, in general.

  4. Measures for the Final Common Core of Constructs. The Project on State-Level Child Outcomes.

    ERIC Educational Resources Information Center

    Child Trends, Inc., Washington, DC.

    The Project on State-Level Child Outcomes, a federal project designed to improve the measurement of child outcomes in state welfare evaluations and in other state data systems. This document provides measures for the common core of constructs that state representatives developed at the second national-level meeting of the Project's planning phase.…

  5. Isotope shift of the 1s2p {sup 3}P{sub 0}-1s2s {sup 1}S{sub 0} level splitting in heavy He-like ions: Implications for atomic parity-nonconservation studies

    SciTech Connect

    Ferro, Fabrizio; Artemyev, Anton; Surzhykov, Andrey; Stoehlker, Thomas

    2010-06-15

    Heavy He-like ions are considered to be promising candidates for atomic parity-nonconservation (PNC) studies, thanks to their relatively simple atomic structure and the significant mixing between the almost degenerate (for the atomic numbers Z{approx}64 and Z{approx}91) opposite-parity levels 1s2s {sup 1}S{sub 0} and 1s2p {sup 3}P{sub 0}. A number of experiments exploiting this level mixing have been proposed, and their implementation requires a precise knowledge of the 2 {sup 3}P{sub 0}-2 {sup 1}S{sub 0} energy splitting for different nuclear charges and isotopes. In this paper we performed a theoretical analysis of the level splitting, employing the relativistic many-body perturbation theory and including QED corrections for all isotopes in the intervals 54{<=}Z{<=}71 and 86{<=}Z{<=}93. Possible candidates for future experimental PNC studies are discussed.

  6. Femtomagnetism in graphene induced by core level excitation of organic adsorbates

    PubMed Central

    Ravikumar, Abhilash; Baby, Anu; Lin, He; Brivio, Gian Paolo; Fratesi, Guido

    2016-01-01

    We predict the induction or suppression of magnetism in the valence shell of physisorbed and chemisorbed organic molecules on graphene occurring on the femtosecond time scale as a result of core level excitations. For physisorbed molecules, where the interaction with graphene is dominated by van der Waals forces and the system is non-magnetic in the ground state, numerical simulations based on density functional theory show that the valence electrons relax towards a spin polarized configuration upon excitation of a core-level electron. The magnetism depends on efficient electron transfer from graphene on the femtosecond time scale. On the other hand, when graphene is covalently functionalized, the system is magnetic in the ground state showing two spin dependent mid gap states localized around the adsorption site. At variance with the physisorbed case upon core-level excitation, the LUMO of the molecule and the mid gap states of graphene hybridize and the relaxed valence shell is not magnetic anymore. PMID:27089847

  7. High resolution core level spectroscopy of hydrogen-terminated (1 0 0) diamond

    NASA Astrophysics Data System (ADS)

    Schenk, A. K.; Rietwyk, K. J.; Tadich, A.; Stacey, A.; Ley, L.; Pakes, C. I.

    2016-08-01

    Synchrotron-based photoelectron spectroscopy experiments are presented that address a long standing inconsistency in the treatment of the C1s core level of hydrogen terminated (1 0 0) diamond. Through a comparison of surface and bulk sensitive measurements we show that there is a surface related core level component to lower binding energy of the bulk diamond component; this component has a chemical shift of -0.16+/- 0.05 eV which has been attributed to carbon atoms which are part of the hydrogen termination. Additionally, our results indicate that the asymmetry of the hydrogen terminated (1 0 0) diamond C1s core level is an intrinsic aspect of the bulk diamond peak which we have attributed to sub-surface carbon layers.

  8. Modeling Shallow Core-Level Transitions in the Reflectance Spectra of Gallium-Containing Semiconductors

    NASA Astrophysics Data System (ADS)

    Stoute, Nicholas; Aspnes, David

    2012-02-01

    The electronic structure of covalent materials is typically approached by band theory. However, shallow core level transitions may be better modeled by an atomic-scale approach. We investigate shallow d-core level reflectance spectra in terms of a local atomic-multiplet theory, a novel application of a theory typically used for higher-energy transitions on more ionic type material systems. We examine specifically structure in reflectance spectra of GaP, GaAs, GaSb, GaSe, and GaAs1-xPx due to transitions that originate from Ga3d core levels and occur in the 20 to 25 eV range. We model these spectra as a Ga^+3 closed-shell ion whose transitions are influenced by perturbations on 3d hole-4p electron final states. These are specifically spin-orbit effects on the hole and electron, and a crystal-field effect on the hole, attributed to surrounding bond charges and positive ligand anions. Empirical radial-strength parameters were obtained by least-squares fitting. General trends with respect to anion electronegativity are consistent with expectations. In addition to the spin-orbit interaction, crystal-field effects play a significant role in breaking the degeneracy of the d levels, and consequently are necessary to understand shallow 3d core level spectra.

  9. Deglacial and lake level fluctuation history recorded in cores, Beaver Lake, Upper Peninsula, Michigan

    USGS Publications Warehouse

    Fisher, Timothy G.; Whitman, Richard L.

    1999-01-01

    Sediment cores collected from the littoral and pelagic zones of Beaver Lake, Michigan record fluctuations in the water level of Lake Superior. Beaver Lake is a small 300 ha lake in Pictured Rocks National Lakeshore (PRNL) now separated from Lake Superior by a dune-capped barrier bar. Cores were collected using a vibracorer from a lake-ice platform in February 1997. A 2.85 m long core in 10 m of water contains well-sorted sand, rhythmites, peat, interbedded sand and gyttja, and is capped with 1 m of massive gyttja. A 9480 BP AMS age from the basal sand provides a minimum deglacial date for the area. Further analysis indicates a sand-dominated depositional environment from a low lake stand at approximately 8500 BP to present. An approximate 8800 BP red to gray sediment color transition records either the cessation of meltwater input from Lake Agassiz or receding ice, while a younger similarly colored transition, 6600 BP in age, likely records sediment reworking in the coastal zone. Four AMS ages on peat range from 8520 to 7340 BP and are indicative of the Houghton low phase. Burial of the peat by stratified sand and gyttja after 7340 BP indicates a rising lake level. Peat at a higher level in the lake basin, encountered in shallow littoral cores, ranges in age from 6800 to 6420 BP, which estimates a 0.91 m rise/century in lake level to the Nipissing level by 5000 BP.

  10. Surface core-level shifts and atomic coordination at a stepped W(110) surface

    SciTech Connect

    Riffe, D.M.; Kim, B.; Erskine, J.L. ); Shinn, N.D. )

    1994-11-15

    Core-level 4[ital f][sub 7/2] photoemission spectra have been measured from a single, bifacial W crystal, which has both a flat W(110) and a vicinal, stepped W(110) [W(320)] surface. This procedure reduces uncertainties in the quantitative description of peaks in the spectra from W(320). Various analyses, including nonlinear least-squares curve fitting, show that the average surface core-level shift (SCS) for W(320) is only [similar to][minus]140 meV, compared to [minus]310 meV for W(110) and that, at a maximum, only two of five terrace rows are isoelectronic to W(110) surface atoms. The absence of a large SCS for the step-edge atoms contradicts earlier interpretations of W(320) core-level spectra and departs significantly from expectations based on atomic-coordination models or tight-binding calculations of a bulk truncated surface. We suggest that systematic errors are responsible for the differences in reported core-level shifts for W(320). Implications of possible step-edge-driven atomic rearrangements are discussed.

  11. Reader Identity and the Common Core: Agency and Identity in Leveled Reading

    ERIC Educational Resources Information Center

    Abodeeb-Gentile, Theresa; Zawilinski, Lisa

    2013-01-01

    This article moves beyond the common core and leveled literacy instruction to demonstrate how diverse learners in one fourth grade classroom, challenged teacher authority in an effort to position themselves as capable readers. In doing so, they implored the teachers to consider the social context of reading as an essential component to the ways in…

  12. Polymers and Cross-Linking: A CORE Experiment to Help Students Think on the Submicroscopic Level

    ERIC Educational Resources Information Center

    Bruce, Mitchell R. M.; Bruce, Alice E.; Avargil, Shirly; Amar, Francois G.; Wemyss, Thomas M.; Flood, Virginia J.

    2016-01-01

    The Polymers and Cross-Linking experiment is presented via a new three phase learning cycle: CORE (Chemical Observations, Representations, Experimentation), which is designed to model productive chemical inquiry and to promote a deeper understanding about the chemistry operating at the submicroscopic level. The experiment is built on two familiar…

  13. Understanding electronegative effects in core-level electron spectroscopies; application to the high temperature superconductors

    NASA Astrophysics Data System (ADS)

    Ramaker, David E.

    1989-12-01

    The nature of the core level reflected in x ray photoelectron spectroscopy, Auger electron spectrosocopy, and x ray absorption near edge structure is considered. An understanding of the effects of anion and cation electronegativity on spectra for the transition metal halides is obtained. This knowledge is applied to understand similar spectra for the high temperature superconductors.

  14. Core-level binding-energy shifts for the metallic elements

    NASA Astrophysics Data System (ADS)

    Johansson, Börje; Mårtensson, Nils

    1980-05-01

    A general treatment of core-level binding-energy shifts in metals relative to the free atom is introduced and applied to all elemental metals in the Periodic Table. The crucial ingredients of the theoretical description are (a) the assumption of a fully screened final state in the metallic case and (b) the (Z+1) approximation for the screening valence charge distribution around the core-ionized site. This core-ionized site is, furthermore, treated as an impurity in an otherwise perfect metal. The combination of the complete screening picture and the (Z+1) approximation makes it possible to introduce a Born-Haber cycle which connects the initial state with the final state of the core-ionization process. From this cycle it becomes evident that the main contributions to the core-level shift are the cohesive energy difference between the (Z+1) and Z metal and an appropriate ionization energy of the (Z+1) atom (usually the first ionization potential). The appearance of the ionization potential in the shift originates from the assumption of a charge-neutral final state, while the contribution from the cohesive energies essentially describes the change of bonding properties between the initial and final state of the site. The calculated shifts show very good agreement with available experimental values (at present, for 19 elements). For the other elements we have made an effort to combine experimental ionization potentials with theoretical calculations in order to obtain accurate estimates of some of the atomic-core-level binding energies. Such energies together with measured metallic binding energies give "pseudoexperimental" shifts for many elements. Our calculated core-level shifts agree exceedingly well also with these data. For some of the transition elements the core-level shift shows a deviating behavior in comparison with that of neighboring elements. This is shown to be due to a difference in the atomic ground-state configuration, such as, for example, d5s in

  15. On sulfur core level binding energies in thiol self-assembly and alternative adsorption sites: An experimental and theoretical study

    SciTech Connect

    Jia, Juanjuan; Kara, Abdelkader E-mail: vladimir.esaulov@u-psud.fr; Pasquali, Luca; Bendounan, Azzedine; Sirotti, Fausto; Esaulov, Vladimir A. E-mail: vladimir.esaulov@u-psud.fr

    2015-09-14

    Characteristic core level binding energies (CLBEs) are regularly used to infer the modes of molecular adsorption: orientation, organization, and dissociation processes. Here, we focus on a largely debated situation regarding CLBEs in the case of chalcogen atom bearing molecules. For a thiol, this concerns the case when the CLBE of a thiolate sulfur at an adsorption site can be interpreted alternatively as due to atomic adsorption of a S atom, resulting from dissociation. Results of an investigation of the characteristics of thiol self-assembled monolayers (SAMs) obtained by vacuum evaporative adsorption are presented along with core level binding energy calculations. Thiol ended SAMs of 1,4-benzenedimethanethiol (BDMT) obtained by evaporation on Au display an unconventional CLBE structure at about 161.25 eV, which is close to a known CLBE of a S atom on Au. Adsorption and CLBE calculations for sulfur atoms and BDMT molecules are reported and allow delineating trends as a function of chemisorption on hollow, bridge, and atop sites and including the presence of adatoms. These calculations suggest that the 161.25 eV peak is due to an alternative adsorption site, which could be associated to an atop configuration. Therefore, this may be an alternative interpretation, different from the one involving the adsorption of atomic sulfur resulting from the dissociation process of the S–C bond. Calculated differences in S(2p) CLBEs for free BDMT molecules, SH group sulfur on top of the SAM, and disulfide are also reported to clarify possible errors in assignments.

  16. First-principles interpretation of core-level spectroscopy of photoelectrochemical materials and processes

    NASA Astrophysics Data System (ADS)

    Pemmaraju, Sri Chaitanya Das; Prendergast, David

    2014-03-01

    We present two case studies of first-principles theoretical methods applied in conjunction with experimental core-level spectroscopy measurements to investigate the electronic structure and dynamical processes in molecular and interfacial systems relevant to photoelectrochemical (PEC) technologies. In the first, we study the core-level and valence spectroscopies of two zinc(II)-porphyrin based Donor-pi-Acceptor (D-p-A) dyes using the occupancy-constrained excited electron and core-hole (XCH) approach and time-dependent density functional theory (TDDFT) simulations. In the second, we use constrained DFT and TDDFT to interpret measured transient core-level shifts in time-resolved femtosecond x-ray photoelectron spectroscopy, investigating the dynamics of the electron injection process from a N3 dye molecule chemisorbed onto a ZnO substrate. These studies illustrate the utility of first-principles methods in guiding the design of better PEC materials. This work was performed at the Molecular Foundry, LBNL, supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

  17. Tetrapeptide unfolding dynamics followed by core-level spectroscopy: a first-principles approach.

    PubMed

    Taioli, Simone; Simonucci, Stefano; A Beccara, Silvio; Garavelli, Marco

    2015-05-01

    In this work we demonstrate that core level analysis is a powerful tool for disentangling the dynamics of a model polypeptide undergoing conformational changes in solution and disulphide bond formation. In particular, we present computer simulations within both initial and final state approximations of 1s sulphur core level shifts (S1s CLS) of the CYFC (cysteine-phenylalanine-tyrosine-cysteine) tetrapeptide for different folding configurations. Using increasing levels of accuracy, from Hartree-Fock and density functional theory to configuration interaction via a multiscale algorithm capable of reducing drastically the computational cost of electronic structure calculations, we find that distinct peptide arrangements present S1s CLS sizeably different (in excess of 0.5 eV) with respect to the reference disulfide bridge state. This approach, leading to experimentally detectable signals, may represent an alternative to other established spectroscopic techniques.

  18. Interference of fluorescence x-rays and coherent excitation of core levels

    SciTech Connect

    Ma, Y. |; Blume, M.

    1994-08-01

    The question of coherence in inelastic x-ray absorption and fluorescence processes among identical interacting atoms is studied using a simple diatomic model. Conditions for the coherence are discussed in terms of energy scales, such as the core hole life-time, instrument energy resolutions, and the splitting of the electronic levels. As in the classical Young double-slit experiment, the primary requirement is that it be impossible to determine which atom has undergone the excitation-decay process.

  19. 2p2 Team News

    NASA Astrophysics Data System (ADS)

    Jones, H.

    2000-06-01

    The 2p2 Team continued towards the implementation at the 2.2-m of the same BOB (Broker for Observation Blocks) observing interface as seen at other ESO telescopes. This requires an interface to be written between the existing BOB software and the non-VLT compatible control software for the Wide-Field Imager (WFI) and 2.2-m. Cristian Urrutia, Tatiana Paz and Eduardo Robledo are heading its development. With this software in place, observers can use the VLT Phase 2 Proposal Preparation System (P2PP) for definition of their exposures, whether they are for Visitor or Service Mode.

  20. Strongly correlated valence electrons and core-level chemical bonding of Lithium at terapascal pressures

    NASA Astrophysics Data System (ADS)

    Hu, Anguang; Zhang, Fan

    2015-03-01

    As the simplest pure metal, lithium exhibits some novel properties on electrical conductivity and crystal structures under high pressure. All-electron density functional theory simulations, recently developed by using the linear combination of localized Slater atomic orbitals, revealed that the bandwidth of its valence bands remains almost unchanged within about 3.5 eV even up to a terapascal pressure range. This indicates that the development from delocalized to strongly correlated electronic systems takes place under compression, resulting in metal-semiconductor and superconductivity transitions together with a sequence of new high-pressure crystal phases, discovered experimentally. In contrast to the valence bands, the core-level bands become broadening up to about 10 eV at terapascal pressures. It means the transformation from chemical non-bonding to bonding for core electrons. Thus, dense lithium under compression can be characterized as core-level chemical bonding and a completely new class of strongly correlated materials with narrow bands filled in s-electron shells only.

  1. Gamma-thermometer-based reactor-core liquid-level detector. [PWR

    SciTech Connect

    Burns, T.J.

    1981-06-16

    A system is provided which employs a modified gamma thermometer for determining the liquid coolant level within a nuclear reactor core. The gamma thermometer which normally is employed to monitor local core heat generation rate (reactor power), is modified by thermocouple junctions and leads to obtain an unambiguous indication of the presence or absence of coolant liquid at the gamma thermometer location. A signal processor generates a signal based on the thermometer surface heat transfer coefficient by comparing the signals from the thermocouples at the thermometer location. The generated signal is a direct indication of loss of coolant due to the change in surface heat transfer when coolant liquid drops below the thermometer location. The loss of coolant indication is independent of reactor power at the thermometer location. Further, the same thermometer may still be used for the normal power monitoring function.

  2. Data Sharing in P2P Systems

    NASA Astrophysics Data System (ADS)

    Hayek, Rabab; Raschia, Guillaume; Valduriez, Patrick; Mouaddib, Noureddine

    In this chapter, we survey P2P data sharing systems. All along, we focus on the evolution from simple file-sharing systems, with limited functionalities, to Peer Data Management Systems (PDMS) that support advanced applications with more sophisticated data management techniques. Advanced P2P applications are dealing with semantically rich data (e.g., XML documents, relational tables), using a high-level SQL-like query language. We start our survey with an overview over the existing P2P network architectures, and the associated routing protocols. Then, we discuss data indexing techniques based on their distribution degree and the semantics they can capture from the underlying data. We also discuss schema management techniques which allow integrating heterogeneous data. We conclude by discussing the techniques proposed for processing complex queries (e.g., range and join queries). Complex query facilities are necessary for advanced applications which require a high level of search expressiveness. This last part shows the lack of querying techniques that allow for an approximate query answering.

  3. Production Level CFD Code Acceleration for Hybrid Many-Core Architectures

    NASA Technical Reports Server (NTRS)

    Duffy, Austen C.; Hammond, Dana P.; Nielsen, Eric J.

    2012-01-01

    In this work, a novel graphics processing unit (GPU) distributed sharing model for hybrid many-core architectures is introduced and employed in the acceleration of a production-level computational fluid dynamics (CFD) code. The latest generation graphics hardware allows multiple processor cores to simultaneously share a single GPU through concurrent kernel execution. This feature has allowed the NASA FUN3D code to be accelerated in parallel with up to four processor cores sharing a single GPU. For codes to scale and fully use resources on these and the next generation machines, codes will need to employ some type of GPU sharing model, as presented in this work. Findings include the effects of GPU sharing on overall performance. A discussion of the inherent challenges that parallel unstructured CFD codes face in accelerator-based computing environments is included, with considerations for future generation architectures. This work was completed by the author in August 2010, and reflects the analysis and results of the time.

  4. Characterization of YBa 2Cu 3O x using core- and valence-level XPS

    NASA Astrophysics Data System (ADS)

    Brundle, C. R.; Fowler, D. E.

    1993-12-01

    Hundreds of papers have been published involving the photoelectron spectroscopy of the high- Tc superconducting oxides since 1987. The early work, originally on bulk-sintered material, sputtered films, and later on "single crystals", concentrated on finding "unusual" features in valence- or core-level spectra to relate to electronic structure effects which might explain the superconducting mechanism. The majority of this work has not adequately taken into account the facts that (a) photoemission probes only the top few monolayers of material, and (b) in many cases the top few layers are completely unrepresentative of the bulk material. This is particularly true for YBa 2Cu 3O x, where the surface is extremely reactive, unstable, and prone to contaminating phases, even when prepared under UHV conditions. This has led to a flood of misinformation concerning the true characteristic spectra of this material and their interpretation. In this paper, we present core- and valence-level XPS for YBa 2Cu 3O x single-crystal, bulk-sintered, and thin-film samples, and show that, when artifacts are eliminated, the characteristic spectra are the same, to first order, and easily allow distinction of surfaces consisting of the genuine orthorhombic phase ( x > 6.4) from those with the non-superconducting tetragonal phase ( x<6.4) or contaminant or reaction-product phases. With this information, it is possible to eliminate much of the previous literature discussion and also to follow the material changes occuring, for instance, during annealing, adsorption and reaction. We then discuss some detailed interpretations, including the DOS observed at and near EF, the explanations for the ˜1.5 eV chemical shift in Ba core-level BE between orthorhombic and tetragonal forms, and the implications of the very low O(1s) BE of the orthorhombic form.

  5. Photoemission core-level shifts reveal the thiolate-Au(111) interface

    SciTech Connect

    Groenbeck, Henrik; Odelius, Michael

    2010-08-15

    The nature of the thiolate/Au(111) interface is a long-standing puzzle. It has been suggested that thiolates drive surface reconstruction, however, a consensus regarding the adsorption configuration is missing. Herein, the density-functional theory is used to evaluate surface core-level shifts (SCLSs) for methyl thiolates on Au(111) assuming a representative set of different surface reconstructions. The SCLSs are found to provide sensitive fingerprints of the anchoring configuration, and it is only thiolate adsorption in the form of MeS-Au-SMe complexes that can be reconciled with experimental data.

  6. Washington State Core Competencies Model Curriculum: English as a Second Language, Level 3. Version 1.0

    ERIC Educational Resources Information Center

    Hagen, Stacey, Ed.; And Others

    The Washington State Core Competencies Project is designed to implement competency-based adult education in the state's 38 adult basic education programs. A model curriculum was developed and field-tested over several years. The resulting curriculum outline of core competencies for English as a Second Language, level 3, is presented here. The…

  7. Washington State Core Competencies Model Curriculum: English as a Second Language, Level 2. Version 1.0.

    ERIC Educational Resources Information Center

    Hagen, Stacey, Ed.; And Others

    The Washington State Core Competencies Project is designed to implement competency-based adult education in the state's 38 adult basic education programs. A model curriculum was developed and field-tested over several years. The resulting curriculum outline of core competencies for English as a Second Language, level 2, is presented here. The…

  8. Quanty for core level spectroscopy - excitons, resonances and band excitations in time and frequency domain

    NASA Astrophysics Data System (ADS)

    Haverkort, Maurits W.

    2016-05-01

    Depending on the material and edge under consideration, core level spectra manifest themselves as local excitons with multiplets, edge singularities, resonances, or the local projected density of states. Both extremes, i.e., local excitons and non-interacting delocalized excitations are theoretically well under control. Describing the intermediate regime, where local many body interactions and band-formation are equally important is a challenge. Here we discuss how Quanty, a versatile quantum many body script language, can be used to calculate a variety of different core level spectroscopy types on solids and molecules, both in the frequency as well as the time domain. The flexible nature of Quanty allows one to choose different approximations for different edges and materials. For example, using a newly developed method merging ideas from density renormalization group and quantum chemistry [1-3], Quanty can calculate excitons, resonances and band-excitations in x-ray absorption, photoemission, x-ray emission, fluorescence yield, non-resonant inelastic x-ray scattering, resonant inelastic x-ray scattering and many more spectroscopy types. Quanty can be obtained from: http://www.quanty.org.

  9. Core-Level Crossing and the High-Pressure Equation of State of Heavy Elements

    NASA Astrophysics Data System (ADS)

    Wills, John

    2015-06-01

    The structural properties of the 5d transition metal osmium have recently been probed at static pressures up to ~ 770 GPa. In this study, anomalies in the hcp c/a ratio were found at pressures of in the vicinity of 150 GPa and 440 GPa. The anomaly at 150 GPa approximately coincides in pressure with an electron topological transition (ETT) observed in Density Functional Theory (DFT) band structure. However, no ETT is observed at higher pressures. Instead, we find that the anomaly in the c / a ratio of osmium is correlated with the crossing of the 5p3 / 2 and 4f7 / 2 ``core'' levels, which at this pressure are found to have bandwidths ~ .2-.3 Ry, in our DFT calculations. In this talk, I discuss the calculated structural properties and calculated equation of state of osmium and other heavy 5d elements at pressures less than 1 TPa and the effect of core-level crossing on the equation of state and structural properties of these elements.

  10. Angle and temperature dependence of magnetic circular dichroism in core-level photoemission from Gd(0001)

    SciTech Connect

    Denecke, R.; Morais, J.; Ynzunza, R. X.; Menchero, J. G.; Liesegang, J.; Rice, M.; Kortright, J.; Hussain, Z.; Fadley, C. S.

    1997-04-01

    Magnetic dichroism in core-level photoelectron emission from solids represents a promising new element-specific probe of surface and interface atomic structure and magnetic order. One way of measuring such effects is by using photoelectrons excited by circular polarized radiation, thus leading to magnetic circular dichroism (MCD) if the intensity with right-circular polarized (RCP) light is not equal to that with left-circular polarized (LCP) light. The spin-integrated photoelectron intensity in a certain emission direction also in general depends on the direction of the magnetization in a magnetic material. In fact, if the magnetization lies in a surface mirror plane, then inverting its direction can provide a second way of measuring MCD. Purely atomic theoretical models have been successful in explaining many aspects of such data. By varying the emission direction one also probes the geometric structure of the sample. But such MCD in photoelectron angular distributions (MCDAD) then has to be interpreted also in terms of photoelectron diffraction. Measuring the temperature dependence of such MCD effects also provides a useful tool for studying magnetic transition temperatures. The authors have here studied such effects in core-level emission from Gd(0001).

  11. The Systems Biology Markup Language (SBML) Level 3 Package: Layout, Version 1 Core.

    PubMed

    Gauges, Ralph; Rost, Ursula; Sahle, Sven; Wengler, Katja; Bergmann, Frank Thomas

    2015-09-04

    Many software tools provide facilities for depicting reaction network diagrams in a visual form. Two aspects of such a visual diagram can be distinguished: the layout (i.e.: the positioning and connections) of the elements in the diagram, and the graphical form of the elements (for example, the glyphs used for symbols, the properties of the lines connecting them, and so on). For software tools that also read and write models in SBML (Systems Biology Markup Language) format, a common need is to store the network diagram together with the SBML representation of the model. This in turn raises the question of how to encode the layout and the rendering of these diagrams. The SBML Level 3 Version 1 Core specification does not provide a mechanism for explicitly encoding diagrams, but it does provide a mechanism for SBML packages to extend the Core specification and add additional syntactical constructs. The Layout package for SBML Level 3 adds the necessary features to SBML so that diagram layouts can be encoded in SBML files, and a companion package called SBML Rendering specifies how the graphical rendering of elements can be encoded. The SBML Layout package is based on the principle that reaction network diagrams should be described as representations of entities such as species and reactions (with direct links to the underlying SBML elements), and not as arbitrary drawings or graphs; for this reason, existing languages for the description of vector drawings (such as SVG) or general graphs (such as GraphML) cannot be used.

  12. Pressure-induced crossing of the core levels in 5 d metals

    NASA Astrophysics Data System (ADS)

    Tal, Alexey A.; Katsnelson, Mikhail I.; Ekholm, Marcus; Jönsson, H. Johan M.; Dubrovinsky, Leonid; Dubrovinskaia, Natalia; Abrikosov, Igor A.

    2016-05-01

    A pressure-induced interaction between core electrons, the core-level crossing (CLC) transition, has been observed in hcp Os at P ≈400 GPa [L. Dubrovinsky et al., Nature (London) 525, 226 (2015)], 10.1038/nature14681. By carrying out a systematic theoretical study for all metals of the 5 d series (Hf, Ta, W, Re, Os, Ir, Pt, Au) we have found that the CLC transition is a general effect for this series of metals. While in Pt it occurs at ≈1500 GPa , at a pressure substantially higher than in Os, in Ir it occurs already at 80 GPa. Moreover, we predict that in Re the CLC transition may take place already at ambient pressure. We explain the effect of the CLC and analyze the shift of the transition pressure across the series within the Thomas-Fermi model. In particular, we show that the effect has many common features with the atomic collapse in rare-earth elements.

  13. Core-level x-ray photoemission: Deviations from threshold behavior

    NASA Astrophysics Data System (ADS)

    Cox, D. L.; Frota, H. O.; Oliveira, L. N.; Wilkins, J. W.

    1985-07-01

    We present a systematic numerical study of core-level x-ray photoemission intensity in metals, with emphasis upon studying the deviations from behavior asymptotically close to threshold. For a model with a contact potential and linear conduction-electron dispersion, we have evaluated the photoemission intensity for core-hole phase shifts δ(0) between 0.05π and 0.5π. We find the following results. (i) The asymptotic regime extends out to 0.01 to 0.1 times the conduction bandwidth (D) from threshold. The range of the asymptotic regime decreases with increasing (absolute) phase shift. (ii) The linear relation between the integrated photoemission intensity and the asymptotic form holds for all phase shifts above ~0.1D. Due to our normalization procedure we cannot say whether it holds below this value. (iii) Discrepancies exist between numerical estimates of the deviations from asymptotic behavior and approximate analytic estimates. (iv) A definition of the frequency-dependent threshold singularity exponent α(ω) in terms of a moment of the photoemission intensity is stable out to the conduction-band edge and may prove useful to experimentalists attempting to extract exponents from their data.

  14. Atomic signatures of local environment from core-level spectroscopy in β -Ga2O3

    NASA Astrophysics Data System (ADS)

    Cocchi, Caterina; Zschiesche, Hannes; Nabok, Dmitrii; Mogilatenko, Anna; Albrecht, Martin; Galazka, Zbigniew; Kirmse, Holm; Draxl, Claudia; Koch, Christoph T.

    2016-08-01

    We present a joint theoretical and experimental study on core-level excitations from the oxygen K edge of β -Ga2O3 . A detailed analysis of the electronic structure reveals the importance of O-Ga hybridization effects in the conduction region. The spectrum from O 1 s core electrons is dominated by excitonic effects, which overall redshift the absorption onset by 0.5 eV, and significantly redistribute the intensity to lower energies. Analysis of the spectra obtained within many-body perturbation theory reveals atomic fingerprints of the inequivalent O atoms. From the comparison of energy-loss near-edge fine-structure (ELNES) spectra computed with respect to different crystal planes, with measurements recorded under the corresponding diffraction conditions, we show how the spectral contributions of specific O atoms can be enhanced while quenching others. These results suggest ELNES, combined with ab initio many-body theory, as a very powerful technique to characterize complex systems, with sensitivity to individual atomic species and to their local environment.

  15. Recommendations for Training in Pediatric Psychology: Defining Core Competencies Across Training Levels

    PubMed Central

    Janicke, David M.; McQuaid, Elizabeth L.; Mullins, Larry L.; Robins, Paul M.; Wu, Yelena P.

    2014-01-01

    Objective As a field, pediatric psychology has focused considerable efforts on the education and training of students and practitioners. Alongside a broader movement toward competency attainment in professional psychology and within the health professions, the Society of Pediatric Psychology commissioned a Task Force to establish core competencies in pediatric psychology and address the need for contemporary training recommendations. Methods The Task Force adapted the framework proposed by the Competency Benchmarks Work Group on preparing psychologists for health service practice and defined competencies applicable across training levels ranging from initial practicum training to entry into the professional workforce in pediatric psychology. Results Competencies within 6 cluster areas, including science, professionalism, interpersonal, application, education, and systems, and 1 crosscutting cluster, crosscutting knowledge competencies in pediatric psychology, are presented in this report. Conclusions Recommendations for the use of, and the further refinement of, these suggested competencies are discussed. PMID:24719239

  16. Broadband single-photon-level memory in a hollow-core photonic crystal fibre

    NASA Astrophysics Data System (ADS)

    Sprague, M. R.; Michelberger, P. S.; Champion, T. F. M.; England, D. G.; Nunn, J.; Jin, X.-M.; Kolthammer, W. S.; Abdolvand, A.; Russell, P. St. J.; Walmsley, I. A.

    2014-04-01

    Storing information encoded in light is critical for realizing optical buffers for all-optical signal processing and quantum memories for quantum information processing. These proposals require efficient interaction between atoms and a well-defined optical mode. Photonic crystal fibres can enhance light-matter interactions and have engendered a broad range of nonlinear effects; however, the storage of light has proven elusive. Here, we report the first demonstration of an optical memory in a hollow-core photonic crystal fibre. We store gigahertz-bandwidth light in the hyperfine coherence of caesium atoms at room temperature using a far-detuned Raman interaction. We demonstrate a signal-to-noise ratio of 2.6:1 at the single-photon level and a memory efficiency of 27 +/- 1%. Our results demonstrate the potential of a room-temperature fibre-integrated optical memory for implementing local nodes of quantum information networks.

  17. Physics of the Be(10{bar 1} 0) Surface Core Level Spectrum

    SciTech Connect

    Lizzit, S.; Pohl, K. |; Baraldi, A.; Comelli, G.; Fritzsche, V.; Plummer, E.W. |; Stumpf, R.; Hofmann, P. ||

    1998-10-01

    Photoelectron diffraction has been utilized to confirm the theoretical prediction that the surface core level shifts observed for Be(10{bar 1}0) have been improperly assigned. The original assignment based upon the relative intensity of the shifted components was intuitively obvious: the peak with the largest shift of {minus}0.7 eV with respect to the bulk was associated with the surface plane, the next peak shifted by {minus}0.5 eV stems from the second layer, and the third peak at {minus}0.22 eV from the third and fourth layers. First-principles theory and our experimental data show that the largest shift is associated with the second plane, not the first plane. {copyright} {ital 1998} {ital The American Physical Society }

  18. Exciton and core-level electron confinement effects in transparent ZnO thin films

    PubMed Central

    Mosquera, Adolfo A.; Horwat, David; Rashkovskiy, Alexandr; Kovalev, Anatoly; Miska, Patrice; Wainstein, Dmitry; Albella, Jose M.; Endrino, Jose L.

    2013-01-01

    The excitonic light emission of ZnO films have been investigated by means of photoluminescence measurements in ultraviolet-visible region. Exciton confinement effects have been observed in thin ZnO coatings with thickness below 20 nm. This is enhanced by a rise of the intensity and a blue shift of the photoluminescence peak after extraction of the adsorbed species upon annealing in air. It is found experimentally that the free exciton energy (determined by the photoluminescence peak) is inversely proportional to the square of the thickness while core-level binding energy is inversely proportional to the thickness. These findings correlate very well with the theory of kinetic and potential confinements.

  19. Characterization of tuyere-level core-drill coke samples from blast furnace operation

    SciTech Connect

    S. Dong; N. Paterson; S.G. Kazarian; D.R. Dugwell; R. Kandiyoti

    2007-12-15

    A suite of tuyere-level coke samples have been withdrawn from a working blast furnace during coal injection, using the core-drilling technique. The samples have been characterized by size exclusion chromatography (SEC), Fourier transform Raman spectroscopy (FT-RS), and X-ray powder diffraction (XRD) spectroscopy. The 1-methyl-2-pyrrolidinone (NMP) extracts of the cokes sampled from the 'bosh', the rear of the 'bird's nest', and the 'dead man' zones were found by SEC to contain heavy soot-like materials (ca. 10{sup 7}-10{sup 8} apparent mass units). In contrast, NMP extracts of cokes taken from the raceway and the front of the 'bird's nest' only contained a small amount of material of relatively lower apparent molecular mass (up to ca. 10{sup 5} u). Since the feed coke contained no materials extractable by the present method, the soot-like materials are thought to have formed during the reactions of volatile matter released from the injectant coal, probably via dehydrogenation and repolymerization of the tars. The Raman spectra of the NMP-extracted core-drilled coke samples showed variations reflecting their temperature histories. Area ratios of D-band to G-band decreased as the exposure temperature increased, while intensity ratios of D to G band and those of 2D to G bands increased with temperature. The graphitic (G), defect (D), and random (R) fractions of the carbon structure of the cokes were also derived from the Raman spectra. The R fractions decreased with increasing temperature, whereas G fractions increased, while the D fractions showed a more complex variation with temperature. These data appear to give clues regarding the graphitization mechanism of tuyere-level cokes in the blast furnace. 41 refs., 9 figs., 6 tabs.

  20. The Systems Biology Markup Language (SBML) Level 3 Package: Layout, Version 1 Core.

    PubMed

    Gauges, Ralph; Rost, Ursula; Sahle, Sven; Wengler, Katja; Bergmann, Frank Thomas

    2015-01-01

    Many software tools provide facilities for depicting reaction network diagrams in a visual form. Two aspects of such a visual diagram can be distinguished: the layout (i.e.: the positioning and connections) of the elements in the diagram, and the graphical form of the elements (for example, the glyphs used for symbols, the properties of the lines connecting them, and so on). For software tools that also read and write models in SBML (Systems Biology Markup Language) format, a common need is to store the network diagram together with the SBML representation of the model. This in turn raises the question of how to encode the layout and the rendering of these diagrams. The SBML Level 3 Version 1 Core specification does not provide a mechanism for explicitly encoding diagrams, but it does provide a mechanism for SBML packages to extend the Core specification and add additional syntactical constructs. The Layout package for SBML Level 3 adds the necessary features to SBML so that diagram layouts can be encoded in SBML files, and a companion package called SBML Rendering specifies how the graphical rendering of elements can be encoded. The SBML Layout package is based on the principle that reaction network diagrams should be described as representations of entities such as species and reactions (with direct links to the underlying SBML elements), and not as arbitrary drawings or graphs; for this reason, existing languages for the description of vector drawings (such as SVG) or general graphs (such as GraphML) cannot be used. PMID:26528565

  1. Optimisation of glaciological parameters for ice core chronology by implementing counted layers between identified depth levels

    NASA Astrophysics Data System (ADS)

    Bazin, L.; Lemieux-Dudon, B.; Landais, A.; Guillevic, M.; Kindler, P.; Parrenin, F.; Martinerie, P.

    2014-08-01

    A~recent coherent chronology has been built for 4 Antarctic ice cores and the NorthGRIP (NGRIP) Greenland ice core (Antarctic Ice Core Chronology 2012, AICC2012) using a bayesian approach for ice core dating (Datice). When building the AICC2012 chronology, and in order to prevent any confusion with official ice cores chronology, it has been imposed that the AICC2012 chronology for NGRIP should respect exactly the GICC05 chronology based on layer counting. However, such a strong tuning did not satisfy the hypothesis of independence of background parameters and observations for the NGRIP core as required by Datice. We present here the implementation in Datice of a new type of markers that is better suited to constraints deduced from layer counting: the markers of age-difference. Using this type of markers for NGRIP in a 5 cores dating exercise with Datice, we have performed several sensitivity tests and show that the new ice core chronologies obtained with these new markers do not differ by more than 400 years from AICC2012 for Antarctic ice cores and by more than 130 years from GICC05 for NGRIP over the last 60 000 years. With this new parameterization, the accumulation rate and lock-in depth associated with NGRIP are more coherent with independent estimates than those obtained in AICC2012. While these new chronologies should not be used yet as new ice core chronologies, the improved methodology presented here should be considered in the next coherent ice core dating exercise.

  2. Antibody to Hepatitis B Core Antigen Levels in the Natural History of Chronic Hepatitis B

    PubMed Central

    Jia, Wei; Song, Liu-Wei; Fang, Yu-Qing; Wu, Xiao-Feng; Liu, Dan-Yang; Xu, Chun; Wang, Xiao-Mei; Wang, Wen; Lv, Dong-Xia; Li, Jun; Deng, Yong-Qiong; Wang, Yan; Huo, Na; Yu, Min; Xi, Hong-Li; Liu, Dan; Zhou, Yi-Xing; Wang, Gui-Qiang; Xia, Ning-Shao; Zhang, Ming-Xiang

    2014-01-01

    Abstract Previous studies have revealed antibody to hepatitis B core antigen (anti-HBc) levels as a predictor of treatment response in hepatitis B early antigen (HBeAg)-positive chronic hepatitis B (CHB) patients in both interferon and nucleos(t)ide analog therapy cohorts. However, there is no information about anti-HBc levels in the natural history of CHB. This study aimed to define anti-HBc levels of different phases in the natural history of CHB. Two hundred eleven treatment-naive CHB patients were included in the study. They were classified into 4 phases: immune tolerance (IT) phase (n = 39), immune clearance (IC) phase (n = 48), low or no-replicative (LR) phase (n = 55), and HBeAg-negative hepatitis (ENH, n = 69). Fifty patients who were HBsAg negative and anti-HBc positive were also recruited as past HBV infection (PBI) control group. Anti-HBc levels were measured by a newly developed double-sandwich immunoassay. Correlation of anti-HBc levels with alanine aminotransferase (ALT) and other HBV-related markers within each phase was performed. Serum anti-HBc levels were statistically significant between patients in different phases of CHB (P < 0.001). The median anti-HBc levels were: IT (3.17 log10 IU/mL), IC (4.39 log10 IU/mL), LR (3.29 log10 IU/mL), ENH (4.12 log10 IU/mL), and PBI (0.61 log10 IU/mL). There existed a strong correlation in IC (r = 0.489, P < 0.001), a poor correlation in ENH (r = 0.275, P = 0.042), and no correlation in patients with ALT reached 5 times upper limit of normal (r = 0.120, P = 0.616). Anti-HBc levels show significant differences during the natural course of CHB. These results may provide some potentially useful insights into hepatitis B pathogenesis and immune activation against hepatitis B virus. PMID:25546679

  3. Initial condition for efficient mapping of level set algorithms on many-core architectures

    NASA Astrophysics Data System (ADS)

    Tornai, Gábor János; Cserey, György

    2014-12-01

    In this paper, we investigated the effect of adding more small curves to the initial condition which determines the required number of iterations of a fast level set (LS) evolution. As a result, we discovered two new theorems and developed a proof on the worst case of the required number of iterations. Furthermore, we found that these kinds of initial conditions fit well to many-core architectures. To show this, we have included two case studies which are presented on different platforms. One runs on a graphical processing unit (GPU) and the other is executed on a cellular nonlinear network universal machine (CNN-UM). With the new initial conditions, the steady-state solutions of the LS are reached in less than eight iterations depending on the granularity of the initial condition. These dense iterations can be calculated very quickly on many-core platforms according to the two case studies. In the case of the proposed dense initial condition on GPU, there is a significant speedup compared to the sparse initial condition in all cases since our dense initial condition together with the algorithm utilizes the properties of the underlying architecture. Therefore, greater performance gain can be achieved (up to 18 times speedup compared to the sparse initial condition on GPU). Additionally, we have validated our concept against numerically approximated LS evolution of standard flows (mean curvature, Chan-Vese, geodesic active regions). The dice indexes between the fast LS evolutions and the evolutions of the numerically approximated partial differential equations are in the range of 0.99±0.003.

  4. Li induced effects in the core level and π-band electronic structure of graphene grown on C-face SiC

    SciTech Connect

    Johansson, Leif I. Xia, Chao; Virojanadara, Chariya

    2015-11-15

    Studies of the effects induced in the electronic structure after Li deposition, and subsequent heating, on graphene samples prepared on C-face SiC are reported. The as prepared graphene samples are essentially undoped, but after Li deposition, the Dirac point shifts down to 1.2 eV below the Fermi level due to electron doping. The shape of the C 1s level also indicates a doping concentration of around 10{sup 14 }cm{sup −2} after Li deposition, when compared with recent calculated results of core level spectra of graphene. The C 1s, Si 2p, and Li 1s core level results show little intercalation directly after deposition but that most of the Li has intercalated after heating at 280 °C. Heating at higher temperatures leads to desorption of Li from the sample, and at 1030 °C, Li can no longer be detected on the sample. The single π-band observable from multilayer C-face graphene samples in conventional angle resolved photoelectron spectroscopy is reasonably sharp both on the initially prepared sample and after Li deposition. After heating at 280 °C, the π-band appears more diffuse and possibly split. The Dirac point becomes located at 0.4 eV below the Fermi level, which indicates occurrence of a significant reduction in the electron doping concentration. Constant energy photoelectron distribution patterns extracted from the as prepared graphene C-face sample and also after Li deposition and heating at 280 °C look very similar to earlier calculated distribution patterns for monolayer graphene.

  5. Electronic states of BP, BP +, BP -, B 2P 2, B2P2- and B2P2+

    NASA Astrophysics Data System (ADS)

    Linguerri, Roberto; Komiha, Najia; Oswald, Rainer; Mitrushchenkov, Alexander; Rosmus, Pavel

    2008-05-01

    Using augmented sextuple zeta basis sets and internally contracted multireference configuration interaction (MRCI) wavefunctions, potential energy, electric dipole and transition moments have been computed for the X 3Π, a 1Σ +, b 1Π and A 3Σ - states of BP, X 2Σ + and A 2Π states of BP - and X 4Σ - and A 4Π states of BP +. From these data spectroscopic constants, radiative transition probabilities and photoelectron spectra of BP - and BP have been evaluated. The non-vanishing spin-orbit coupling elements between the four low lying triplet and singlet states of the neutral BP have also been calculated from MRCI wavefunctions. The treatment of the corresponding perturbations in the manifold of dense rovibrational states in the three lowest states would require a precise knowledge of the electronic excitation energies. Our best singlet-triplet separations (X-a) are calculated to be 2412 cm -1 (MRCI) and 2482 cm -1 (restricted coupled cluster with perturbative triples (RCCSD(T))) with an estimated error bound of about ±200 cm -1. All three states have long radiative lifetimes with cascading among the rovibrational levels of different states. The ionization energy IE e of BP is calculated to be 9.22 eV (MRCI) and 9.48 eV (RCCSD(T)), the electron affinity EA e 2.51 eV (MRCI) and 2.74 eV (RCCSD(T)). The photoelectron spectra of BP and BP - have been obtained from the Franck-Condon factors of the MRCI potentials. For the UV spectroscopy the dipole allowed radiative transition probabilities are given for A 3Σ - ↔ X 3Π, b 1Π ↔ a 1Σ + of BP, A 2Π ↔ X 2Σ + of BP - and A 4Π ↔ X 4Σ - of BP +. The ionization energy IE e of B 2P 2 of 8.71 eV and the electron affinity EA e of 2.34 eV have been calculated by the RCCSD(T)/aVQZ approach. Also the harmonic vibrational wavenumbers for the electronic ground states of the ions B2P2+ and B2P2- are given.

  6. Social Studies. Levels 7-12. Revised. Secondary Core Curriculum Standards.

    ERIC Educational Resources Information Center

    Utah State Board of Education, Salt Lake City.

    The Utah 1991 revised social studies core curriculum guide specifies standards that must be completed by all students in grades 7-12 in order to meet Utah graduation standards. A review of the K-6 social studies curriculum also is included. The core curriculum is intended to represent ideas, concepts, and skills that provide a basic social studies…

  7. Elementary Core Curriculum Standards, Levels K-6, Reading/Language Arts. Revised.

    ERIC Educational Resources Information Center

    Utah State Board of Education, Salt Lake City.

    This paper presents the revised Core Curriculum standards (the essential ideas, concepts, and skills) for the K-6 reading language arts required of students in Utah. It notes that the Core should be taught with respect for differences in learning styles, learning rates, and individual capabilities without losing sight of the common goals.…

  8. Raising FLAGS: Renewing Core French at the Pre-Service Teacher Level

    ERIC Educational Resources Information Center

    Carr, Wendy

    2010-01-01

    A new program for core French teacher candidates called FLAGS (French Language and Global Studies) was established at the University of British Columbia (UBC) in 2007. The program is intended for those who are keen to teach core French and possess rudimentary proficiency in the language but may not necessarily have the same proficiency or prior…

  9. The Systems Biology Markup Language (SBML): Language Specification for Level 3 Version 1 Core.

    PubMed

    Hucka, Michael; Bergmann, Frank T; Hoops, Stefan; Keating, Sarah M; Sahle, Sven; Schaff, James C; Smith, Lucian P; Wilkinson, Darren J

    2015-01-01

    Computational models can help researchers to interpret data, understand biological function, and make quantitative predictions. The Systems Biology Markup Language (SBML) is a file format for representing computational models in a declarative form that can be exchanged between different software systems. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Version 1 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML as well as their encoding in XML, the eXtensible Markup Language. This specification also defines validation rules that determine the validity of an SBML document, and provides many examples of models in SBML form. Other materials and software are available from the SBML project web site, http://sbml.org/. PMID:26528564

  10. Intellectual property protection of IP cores through high-level watermarking

    NASA Astrophysics Data System (ADS)

    Castillo, E.; Meyer-Baese, U.; García, A.; Parrilla, L.; Lloris, A.

    2007-04-01

    In this paper a watermarking technique for Intellectual Property Protection (IPP) of FPGA-based systems is proposed. The aim is to protect the author rights of reusable IP cores by means of a digital signature that uniquely identifies both the original design and the design recipient. The proposed watermarking technique relies on a procedure that spreads the digital signature in cells of memory structures at Hardware Description Language (HDL) design level, not increasing the area of the system. This signature is preserved through synthesis, placement and routing processes. The technique includes a procedure for signature extraction requiring minimal modifications to the system. Thus, it is possible to detect the ownership rights without interfering the normal operation of the system and providing high invulnerability. To illustrate the properties of the proposed watermarking technique, both protected and unprotected design examples are compared in terms of area and performance. The analysis of the results shows that the area increase is very low while throughput penalization is almost negligible.

  11. The effect of core level crossing on the high-pressure equation of state of osmium

    NASA Astrophysics Data System (ADS)

    Wills, John

    2015-03-01

    The equation of state of the 5d transition metal osmium has been studied with a combination of experiment and theory at pressures up to 500 GPa. The experimental results show a c/a ratio increasing by approximately 1 percent over this pressure range and displaying anomalies at pressures near 180 GPa and near 400 GPa. We have use all-electron fully relativistic density functional theory (DFT) calculations to study the cold equation of state and structural parameters of osmium at pressures up to 500 GPa, using one LDA and two GGA functionals. The increase in the c/a ratio agrees well with experiment, and we find anomalies, although less extreme, near the experimentally observed pressures. We find that the high pressure anomaly coincides with the crossing and hybridization of the 4f(7/2) and 5p(3/2) semi-core levels. In this talk we discuss the theoretical results and methodology and the possible implication for the equations of state of the 5d transition and actinide metals.

  12. The Systems Biology Markup Language (SBML): Language Specification for Level 3 Version 1 Core.

    PubMed

    Hucka, Michael; Bergmann, Frank T; Hoops, Stefan; Keating, Sarah M; Sahle, Sven; Schaff, James C; Smith, Lucian P; Wilkinson, Darren J

    2015-09-04

    Computational models can help researchers to interpret data, understand biological function, and make quantitative predictions. The Systems Biology Markup Language (SBML) is a file format for representing computational models in a declarative form that can be exchanged between different software systems. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Version 1 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML as well as their encoding in XML, the eXtensible Markup Language. This specification also defines validation rules that determine the validity of an SBML document, and provides many examples of models in SBML form. Other materials and software are available from the SBML project web site, http://sbml.org/.

  13. Intermediate Coupling For Core-Level Excited States: Consequences For X-Ray Absorption Spectroscopy

    SciTech Connect

    Bagus, Paul S.; Sassi, Michel JPC; Rosso, Kevin M.

    2015-04-15

    The origin of the complex NEXAFS features of X-Ray Absorption, XAS, spectra in transition metal complexes is analyzed and interpreted in terms of the angular momentum coupling of the open shell electrons. Especially for excited configurations where a core-electron is promoted to an open valence shell, the angular momentum coupling is intermediate between the two limits of Russell- Saunders, RS, coupling where spin-orbit splitting of the electron shells is neglected and j-j coupling where this splitting is taken as dominant. The XAS intensities can be understood in terms of two factors: (1) The dipole selection rules that give the allowed excited RS multiplets and (2) The contributions of these allowed multiplets to the wavefunctions of the intermediate coupled levels. It is shown that the origin of the complex XAS spectra is due to the distribution of the RS allowed multiplets over several different intermediate coupled excited levels. The specific case that is analyzed is the L2,3 edge XAS of an Fe3+ cation, because this cation allows a focus on the angular momentum coupling to the exclusion of other effects; e.g., chemical bonding. Arguments are made that the properties identified for this atomic case are relevant for more complex materials. The analysis is based on the properties of fully relativistic, ab initio, many-body wavefunctions for the initial and final states of the XAS process. The wavefunction properties considered include the composition of the wavefunctions in terms of RS multiplets and the occupations of the spin-orbit split open shells; the latter vividly show whether the coupling is j-j or not.

  14. Engineering task plan for upgrades to the leveling jacks on core sample trucks number 3 and 4

    SciTech Connect

    KOSTELNIK, A.J.

    1999-02-24

    Characterizing the waste in underground storage tanks at the Hanford Site is accomplished by obtaining a representative core sample for analysis. Core sampling is one of the numerous techniques that have been developed for use given the environmental and field conditions at the Hanford Site. Core sampling is currently accomplished using either Push Mode Core Sample Truck No.1 or; Rotary Mode Core Sample Trucks No.2, 3 or 4. Past analysis (WHC 1994) has indicated that the Core Sample Truck (CST) leveling jacks are structurally inadequate when lateral loads are applied. WHC 1994 identifies many areas where failure could occur. All these failures are based on exceeding the allowable stresses listed in the American Institute of Steel Construction (AISC) code. The mode of failure is for the outrigger attachments to the truck frame to fail resulting in dropping of the CST and possible overturning (Ref. Ziada and Hundal, 1996). Out of level deployment of the truck can exceed the code allowable stresses in the structure. Calculations have been performed to establish limits for maintaining the truck level when lifting. The calculations and the associated limits are included in appendix A. The need for future operations of the CSTS is limited. Sampling is expected to be complete in FY-2001. Since there is limited time at risk for continued use of the CSTS with the leveling controls without correcting the structural problems, there are several design changes that could give incremental improvements to the operational safety of the CSTS with limited impact on available operating time. The improvements focus on making the truck easier to control during lifting and leveling. Not all of the tasks identified in this ETP need to be performed. Each task alone can improve the safety. This engineering task plan is the management plan document for implementing the necessary additional structural analysis. Any additional changes to meet requirements of standing orders shall require a

  15. Nucleophilic substitution at phosphorus centers (SN2@p).

    PubMed

    van Bochove, Marc A; Swart, Marcel; Bickelhaupt, F Matthias

    2007-12-01

    We have studied the characteristics of archetypal model systems for bimolecular nucleophilic substitution at phosphorus (SN2@P) and, for comparison, at carbon (SN2@C) and silicon (SN2@Si) centers. In our studies, we applied the generalized gradient approximation (GGA) of density functional theory (DFT) at the OLYP/TZ2P level. Our model systems cover nucleophilic substitution at carbon in X(-)+CH3Y (SN2@C), at silicon in X(-)+SiH3Y (SN2@Si), at tricoordinate phosphorus in X(-)+PH2Y (SN2@P3), and at tetracoordinate phosphorus in X(-)+POH2Y (SN2@P4). The main feature of going from SN2@C to SN2@P is the loss of the characteristic double-well potential energy surface (PES) involving a transition state [X--CH3--Y]- and the occurrence of a single-well PES with a stable transition complex, namely, [X--PH2--Y]- or [X--POH2--Y](-). The differences between SN2@P3 and SN2@P4 are relatively small. We explored both the symmetric and asymmetric (i.e. X, Y=Cl, OH) SN2 reactions in our model systems, the competition between backside and frontside pathways, and the dependence of the reactions on the conformation of the reactants. Furthermore, we studied the effect, on the symmetric and asymmetric SN2@P3 and S(N)2@P4 reactions, of replacing hydrogen substituents at the phosphorus centers by chlorine and fluorine in the model systems X(-)+PR2Y and X(-)+POR2Y, with R=Cl, F. An interesting phenomenon is the occurrence of a triple-well PES not only in the symmetric, but also in the asymmetric SN2@P4 reactions of X(-)+POCl2--Y. PMID:17990249

  16. Pronounced Surface Band Bending of Thin-Film Silicon Revealed by Modeling Core Levels Probed with Hard X-rays.

    PubMed

    Wippler, David; Wilks, Regan G; Pieters, Bart E; van Albada, Sacha J; Gerlach, Dominic; Hüpkes, Jürgen; Bär, Marcus; Rau, Uwe

    2016-07-13

    Enhancing the probing depth of photoemission studies by using hard X-rays allows the investigation of buried interfaces of real-world device structures. However, it also requires the consideration of photoelectron-signal attenuation when evaluating surface effects. Here, we employ a computational model incorporating surface band bending and exponential photoelectron-signal attenuation to model depth-dependent spectral changes of Si 1s and Si 2s core level lines. The data were acquired from hydrogenated boron-doped microcrystalline thin-film silicon, which is applied in silicon-based solar cells. The core level spectra, measured by hard X-ray photoelectron spectroscopy using different excitation energies, reveal the presence of a 0.29 nm thick surface oxide layer. In the silicon film a downward surface band bending of eVbb = -0.65 eV over ∼6 nm obtained via inverse modeling explains the observed core level shifts and line broadening. Moreover, the computational model allows the extraction of the "real" Si 1s and Si 2s bulk core level binding energies as 1839.13 and 150.39 eV, and their natural Lorentzian line widths as 496 and 859 meV, respectively. These values significantly differ from those directly extracted from the measured spectra. Because band bending usually occurs at material surfaces we highly recommend the detailed consideration of signal integration over depth for quantitative statements from depth-dependent measurements.

  17. Energy levels, Auger branching ratios, and radiative rates of the core-excited states of B-like carbon

    SciTech Connect

    Sun Yan; Gou Bingcong; Chen Feng

    2011-09-28

    Energy levels, Auger branching ratios, and radiative rates of the core-excited states of B-like carbon are calculated by the saddle-point variation and saddle-point complex-rotation methods. Relativistic and mass polarization corrections are included using first-order perturbation theory. Calculated Auger channel energies and branching ratios are used to identify high-resolution Auger spectrum in the 300-keV C{sup +}{yields} CH{sub 4} collision experiment. It is found that Auger decay of these five-electron core-excited states gives significant contributions to Auger spectrum in the range of 238-280 eV.

  18. Core sampling beneath low-level radioactive-waste burial trenches, West Valley, Cattaraugus County, New York

    USGS Publications Warehouse

    Prudic, David E.

    1979-01-01

    A technique was developed for collecting cores for radiometric analysis from beneath a low-level radioactive-waste landfill to determine the rates of downward radionuclide migration below the trenches. A closed pipe was driven through the buried waste, and a removable point withdrawn. The hole was then advanced by alternately pushing a coring device, then driving an inner casing to the depth reached by the coring device and cleaning out cuttings from within the casing. The effectiveness of the technique was limited by inability to predict the location of impenetrable objects within the waste in some parts of the burial ground and difficulty in detecting when the end of the pipe first penetrated undisturbed material beneath the trench floor. Geophysical logs of the completed hole were used to help determine the trench-floor depth. (USGS).

  19. Direct imaging the upconversion nanocrystal core/shell structure at the subnanometer level: shell thickness dependence in upconverting optical properties.

    PubMed

    Zhang, Fan; Che, Renchao; Li, Xiaomin; Yao, Chi; Yang, Jianping; Shen, Dengke; Hu, Pan; Li, Wei; Zhao, Dongyuan

    2012-06-13

    Lanthanide-doped upconversion nanoparticles have shown considerable promise in solid-state lasers, three-dimensional flat-panel displays, and solar cells and especially biological labeling and imaging. It has been demonstrated extensively that the epitaxial coating of upconversion (UC) core crystals with a lattice-matched shell can passivate the core and enhance the overall upconversion emission intensity of the materials. However, there are few papers that report a precise link between the shell thickness of core/shell nanoparticles and their optical properties. This is mainly because rare earth fluoride upconversion core/shell structures have only been inferred from indirect measurements to date. Herein, a reproducible method to grow a hexagonal NaGdF(4) shell on NaYF(4):Yb,Er nanocrystals with monolayer control thickness is demonstrated for the first time. On the basis of the cryo-transmission electron microscopy, rigorous electron energy loss spectroscopy, and high-angle annular dark-field investigations on the core/shell structure under a low operation temperature (96 K), direct imaging the NaYF(4):Yb,Er@NaGdF(4) nanocrystal core/shell structure at the subnanometer level was realized for the first time. Furthermore, a strong linear link between the NaGdF(4) shell thickness and the optical response of the hexagonal NaYF(4):Yb,Er@NaGdF(4) core/shell nanocrystals has been established. During the epitaxial growth of the NaGdF(4) shell layer by layer, surface defects of the nanocrystals can be gradually passivated by the homogeneous shell deposition process, which results in the obvious enhancement in overall UC emission intensity and lifetime and is more resistant to quenching by water molecules. PMID:22545710

  20. Direct imaging the upconversion nanocrystal core/shell structure at the subnanometer level: shell thickness dependence in upconverting optical properties.

    PubMed

    Zhang, Fan; Che, Renchao; Li, Xiaomin; Yao, Chi; Yang, Jianping; Shen, Dengke; Hu, Pan; Li, Wei; Zhao, Dongyuan

    2012-06-13

    Lanthanide-doped upconversion nanoparticles have shown considerable promise in solid-state lasers, three-dimensional flat-panel displays, and solar cells and especially biological labeling and imaging. It has been demonstrated extensively that the epitaxial coating of upconversion (UC) core crystals with a lattice-matched shell can passivate the core and enhance the overall upconversion emission intensity of the materials. However, there are few papers that report a precise link between the shell thickness of core/shell nanoparticles and their optical properties. This is mainly because rare earth fluoride upconversion core/shell structures have only been inferred from indirect measurements to date. Herein, a reproducible method to grow a hexagonal NaGdF(4) shell on NaYF(4):Yb,Er nanocrystals with monolayer control thickness is demonstrated for the first time. On the basis of the cryo-transmission electron microscopy, rigorous electron energy loss spectroscopy, and high-angle annular dark-field investigations on the core/shell structure under a low operation temperature (96 K), direct imaging the NaYF(4):Yb,Er@NaGdF(4) nanocrystal core/shell structure at the subnanometer level was realized for the first time. Furthermore, a strong linear link between the NaGdF(4) shell thickness and the optical response of the hexagonal NaYF(4):Yb,Er@NaGdF(4) core/shell nanocrystals has been established. During the epitaxial growth of the NaGdF(4) shell layer by layer, surface defects of the nanocrystals can be gradually passivated by the homogeneous shell deposition process, which results in the obvious enhancement in overall UC emission intensity and lifetime and is more resistant to quenching by water molecules.

  1. Grade Level and Performance on the Core Battery, 1986-87 National Administration.

    ERIC Educational Resources Information Center

    DeMauro, Gerald E.

    Among the three NTE Core Battery tests, Professional Knowledge purports to measure skills that are acquired only after academic experience as an education major, while Communication Skills and General Knowledge both purport to measure skills that do not require this specialized experience. The scores of education majors for the 1986-87 national…

  2. Common Core State Standards in 2014: Curriculum and Professional Development at the District Level

    ERIC Educational Resources Information Center

    Rentner, Diane Stark; Kober, Nancy

    2014-01-01

    The Common Core State Standards (CCSS) in mathematics and English language arts (ELA) outline the knowledge and skills that students are expected to learn throughout their K-12 education in order to be prepared for college and careers when they graduate. As of October 2014, 42 states and the District of Columbia have adopted the standards in both…

  3. Microstructure-dependent mechanical properties of electrospun core-shell scaffolds at multi-scale levels.

    PubMed

    Horner, Christopher B; Ico, Gerardo; Johnson, Jed; Zhao, Yi; Nam, Jin

    2016-06-01

    Mechanical factors among many physiochemical properties of scaffolds for stem cell-based tissue engineering significantly affect tissue morphogenesis by controlling stem cell behaviors including proliferation and phenotype-specific differentiation. Core-shell electrospinning provides a unique opportunity to control mechanical properties of scaffolds independent of surface chemistry, rendering a greater freedom to tailor design for specific applications. In this study, we synthesized electrospun core-shell scaffolds having different core composition and/or core-to-shell dimensional ratios. Two independent biocompatible polymer systems, polyetherketoneketone (PEKK) and gelatin as the core materials while maintaining the shell polymer with polycaprolactone (PCL), were utilized. The mechanics of such scaffolds was analyzed at the microscale and macroscales to determine the potential implications it may hold for cell-material and tissue-material interactions. The mechanical properties of individual core-shell fibers were controlled by core-shell composition and structure. The individual fiber modulus correlated with the increase in percent core size ranging from 0.55±0.10GPa to 1.74±0.22GPa and 0.48±0.12GPa to 1.53±0.12GPa for the PEKK-PCL and gelatin-PCL fibers, respectively. More importantly, it was demonstrated that mechanical properties of the scaffolds at the macroscale were dominantly determined by porosity under compression. The increase of scaffold porosity from 70.2%±1.0% to 93.2%±0.5% by increasing the core size in the PEKK-PCL scaffold resulted in the decrease of the compressive elastic modulus from 227.67±20.39kPa to 14.55±1.43kPa while a greater changes in the porosity of gelatin-PCL scaffold from 54.5%±4.2% to 89.6%±0.4% resulted in the compressive elastic modulus change from 484.01±30.18kPa to 17.57±1.40kPa. On the other hand, the biphasic behaviors under tensile mechanical loading result in a range from a minimum of 5.42±1.05MPa to a maximum

  4. Microstructure-dependent mechanical properties of electrospun core-shell scaffolds at multi-scale levels.

    PubMed

    Horner, Christopher B; Ico, Gerardo; Johnson, Jed; Zhao, Yi; Nam, Jin

    2016-06-01

    Mechanical factors among many physiochemical properties of scaffolds for stem cell-based tissue engineering significantly affect tissue morphogenesis by controlling stem cell behaviors including proliferation and phenotype-specific differentiation. Core-shell electrospinning provides a unique opportunity to control mechanical properties of scaffolds independent of surface chemistry, rendering a greater freedom to tailor design for specific applications. In this study, we synthesized electrospun core-shell scaffolds having different core composition and/or core-to-shell dimensional ratios. Two independent biocompatible polymer systems, polyetherketoneketone (PEKK) and gelatin as the core materials while maintaining the shell polymer with polycaprolactone (PCL), were utilized. The mechanics of such scaffolds was analyzed at the microscale and macroscales to determine the potential implications it may hold for cell-material and tissue-material interactions. The mechanical properties of individual core-shell fibers were controlled by core-shell composition and structure. The individual fiber modulus correlated with the increase in percent core size ranging from 0.55±0.10GPa to 1.74±0.22GPa and 0.48±0.12GPa to 1.53±0.12GPa for the PEKK-PCL and gelatin-PCL fibers, respectively. More importantly, it was demonstrated that mechanical properties of the scaffolds at the macroscale were dominantly determined by porosity under compression. The increase of scaffold porosity from 70.2%±1.0% to 93.2%±0.5% by increasing the core size in the PEKK-PCL scaffold resulted in the decrease of the compressive elastic modulus from 227.67±20.39kPa to 14.55±1.43kPa while a greater changes in the porosity of gelatin-PCL scaffold from 54.5%±4.2% to 89.6%±0.4% resulted in the compressive elastic modulus change from 484.01±30.18kPa to 17.57±1.40kPa. On the other hand, the biphasic behaviors under tensile mechanical loading result in a range from a minimum of 5.42±1.05MPa to a maximum

  5. Species-level core oral bacteriome identified by 16S rRNA pyrosequencing in a healthy young Arab population

    PubMed Central

    Al-hebshi, Nezar Noor; Abdulhaq, Ahmed; Albarrag, Ahmed; Basode, Vinod Kumar; Chen, Tsute

    2016-01-01

    Background Reports on the composition of oral bacteriome in Arabs are lacking. In addition, the majority of previous studies on other ethnic groups have been limited by low-resolution taxonomic assignment of next-generation sequencing reads. Furthermore, there has been a conflict about the existence of a ‘core’ bacteriome. Objective The objective of this study was to characterize the healthy core oral bacteriome in a young Arab population at the species level. Methods Oral rinse DNA samples obtained from 12 stringently selected healthy young subjects of Arab origin were pyrosequenced (454's FLX chemistry) for the bacterial 16S V1–V3 hypervariable region at an average depth of 11,500 reads. High-quality, non-chimeric reads ≥380 bp were classified to the species level using the recently described, prioritized, multistage assignment algorithm. A core bacteriome was defined as taxa present in at least 11 samples. The Chao2, abundance-based coverage estimator (ACE), and Shannon indices were computed to assess species richness and diversity. Results Overall, 557 species-level taxa (211±42 per subject) were identified, representing 122 genera and 13 phyla. The core bacteriome comprised 55 species-level taxa belonging to 30 genera and 7 phyla, namely Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, Fusobacteria, Saccharibacteria, and SR1. The core species constituted between 67 and 87% of the individual bacteriomes. However, the abundances differed by up to three orders of magnitude among the study subjects. On average, Streptococcus mitis, Rothia mucilaginosa, Haemophilus parainfluenzae, Neisseria flavescence/subflava group, Prevotella melaninogenica, and Veillonella parvula group were the most abundant. Streptococcus sp. C300, a taxon never reported in the oral cavity, was identified as a core species. Species richness was estimated at 586 (Chao2) and 614 (ACE) species, whereas diversity (Shannon index) averaged at 3.99. Conclusions A species-level

  6. Levels of metals and semimetals in sedimentary cores in Bertioga Channel, Brazil

    NASA Astrophysics Data System (ADS)

    Sartoretto, J. R.; Salaroli, A.; Figueira, R. C.

    2013-05-01

    The Baixada Santista is one of the most exploited and populated regions of São Paulo state. During the last decades, due to intense industrialization the Baixada Santista has passed through a strong process of environmental degradation. Metals in sediments are persistent, present toxicity in varied concentrations and may be deposited reaching biota habitats. In this context, high concentrations of metals represent environmental concern to costal management. Bertioga Channel is part of this complex system and is known mainly by a wide adjacent mangrove area. The channel is 25 km long, connecting the upstream region of Santos estuary to the adjacent ocean through an inlet located at the city of Bertioga. Urban development generates the concern of potential waste influx from surrounding streams, generating deposits and contaminating surface sediments along the channel, which may lead to adjacent coastal issues. The objective of this study was to characterize the concentration of the following metals at Bertioga Channel sediments: Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sc, V and Zn. Five sediment cores were sampled along the channel and analyzed. Determination of metals concentration was based on methods SW 846 US EPA 3050B and EPA 7471. High As concentrations were observed at all cores, with considerable concentration similarity between the first and second sampling points. Analytical results showed that cores Bertioga 4 and Bertioga 5 have accumulated high quantity of metals and semimetals, mainly As, Cd and Cr. Normalization of concentration values showed low contamination at the cores. Nevertheless, As and Hg values indicated moderate to significant contamination at a few sampling points. Despite of the low probability of contamination demonstrated by the normalized values, increasing at the sediment surface of Enrichment Factor (ER), Pollution Load Index (PLI) and Sediment Pollution Index (SPI) parameters were observed. Results indicate that industrialization

  7. Theoretical predictions of the impact of nuclear dynamics and environment on core-level spectra of organic molecules

    NASA Astrophysics Data System (ADS)

    Prendergast, David; Schwartz, Craig; Uejio, Janel; Saykally, Richard

    2009-03-01

    Core-level spectroscopy provides an element-specific probe of local electronic structure and bonding, but linking details of atomic structure to measured spectra relies heavily on accurate theoretical interpretation. We present first principles simulations of the x-ray absorption of a range of organic molecules both in isolation and aqueous solvation, highlighting the spectral impact of internal nuclear motion as well as solvent interactions. Our approach uses density functional theory with explicit inclusion of the core-level excited state within a plane-wave supercell framework. Nuclear degrees of freedom are sampled using various molecular dynamics techniques. We indicate specific cases for molecules in their vibrational ground state at experimental conditions, where nuclear quantum effects must be included. Prepared by LBNL under Contract DE-AC02-05CH11231.

  8. The electronic characterization of biphenylene—Experimental and theoretical insights from core and valence level spectroscopy

    SciTech Connect

    Lüder, Johann; Sanyal, Biplab; Eriksson, Olle; Brena, Barbara; Puglia, Carla; Simone, Monica de; Totani, Roberta; Coreno, Marcello; Grazioli, Cesare

    2015-02-21

    In this paper, we provide detailed insights into the electronic structure of the gas phase biphenylene molecule through core and valence spectroscopy. By comparing results of X-ray Photoelectron Spectroscopy (XPS) measurements with ΔSCF core-hole calculations in the framework of Density Functional Theory (DFT), we could decompose the characteristic contributions to the total spectra and assign them to non-equivalent carbon atoms. As a difference with similar molecules like biphenyl and naphthalene, an influence of the localized orbitals on the relative XPS shifts was found. The valence spectrum probed by photoelectron spectroscopy at a photon energy of 50 eV in conjunction with hybrid DFT calculations revealed the effects of the localization on the electronic states. Using the transition potential approach to simulate the X-ray absorption spectroscopy measurements, similar contributions from the non-equivalent carbon atoms were determined from the total spectrum, for which the slightly shifted individual components can explain the observed asymmetric features.

  9. Molecular Spectroscopy in Hollow-Core Photonic Crystal Fiber at the 10 kHz Level

    NASA Astrophysics Data System (ADS)

    Wang, Chenchen; Knabe, Kevin; Wu, Shun; Lim, Jinkang; Tillman, Karl; Washburn, Brian; Corwin, Kristan; Wheeler, Natalie; Couny, Francois; Benabid, Fetah

    2010-03-01

    High-accuracy spectroscopy in hollow-core photonic crystal fiber (HC-PCF) is desirable for many applications, including frequency references and trace gas analysis. We demonstrate the narrowest sub-Doppler linewidths attained in HC-PCF using large-core kagome structured fiber. Such fibers can yield highly accurate frequency measurements that are about two orders of magnitude higher than previously reported. A fiber laser is locked to the ^12C2H2 ν1+ν3 P(13) transition inside kagome fiber, and compared with two optical frequency combs referenced to a GPS-disciplined Rb oscillator. The absolute frequency of the measured line center agrees with those measured in power build-up cavities to within 9.3 kHz (1 σ error). Approaches to further narrow the linewidths and improve systematic errors are investigated. The present system thus combines accuracy approaching that of power build-up cavities with the potential to be compact, robust, and integrated into an all-fiber system for a portable near-infrared frequency reference. Supported by AFOSR FA9950-05-1-0304 and NSF ECS-0449295.

  10. Determinants of Default in P2P Lending

    PubMed Central

    2015-01-01

    This paper studies P2P lending and the factors explaining loan default. This is an important issue because in P2P lending individual investors bear the credit risk, instead of financial institutions, which are experts in dealing with this risk. P2P lenders suffer a severe problem of information asymmetry, because they are at a disadvantage facing the borrower. For this reason, P2P lending sites provide potential lenders with information about borrowers and their loan purpose. They also assign a grade to each loan. The empirical study is based on loans’ data collected from Lending Club (N = 24,449) from 2008 to 2014 that are first analyzed by using univariate means tests and survival analysis. Factors explaining default are loan purpose, annual income, current housing situation, credit history and indebtedness. Secondly, a logistic regression model is developed to predict defaults. The grade assigned by the P2P lending site is the most predictive factor of default, but the accuracy of the model is improved by adding other information, especially the borrower’s debt level. PMID:26425854

  11. Determinants of Default in P2P Lending.

    PubMed

    Serrano-Cinca, Carlos; Gutiérrez-Nieto, Begoña; López-Palacios, Luz

    2015-01-01

    This paper studies P2P lending and the factors explaining loan default. This is an important issue because in P2P lending individual investors bear the credit risk, instead of financial institutions, which are experts in dealing with this risk. P2P lenders suffer a severe problem of information asymmetry, because they are at a disadvantage facing the borrower. For this reason, P2P lending sites provide potential lenders with information about borrowers and their loan purpose. They also assign a grade to each loan. The empirical study is based on loans' data collected from Lending Club (N = 24,449) from 2008 to 2014 that are first analyzed by using univariate means tests and survival analysis. Factors explaining default are loan purpose, annual income, current housing situation, credit history and indebtedness. Secondly, a logistic regression model is developed to predict defaults. The grade assigned by the P2P lending site is the most predictive factor of default, but the accuracy of the model is improved by adding other information, especially the borrower's debt level.

  12. Determinants of Default in P2P Lending.

    PubMed

    Serrano-Cinca, Carlos; Gutiérrez-Nieto, Begoña; López-Palacios, Luz

    2015-01-01

    This paper studies P2P lending and the factors explaining loan default. This is an important issue because in P2P lending individual investors bear the credit risk, instead of financial institutions, which are experts in dealing with this risk. P2P lenders suffer a severe problem of information asymmetry, because they are at a disadvantage facing the borrower. For this reason, P2P lending sites provide potential lenders with information about borrowers and their loan purpose. They also assign a grade to each loan. The empirical study is based on loans' data collected from Lending Club (N = 24,449) from 2008 to 2014 that are first analyzed by using univariate means tests and survival analysis. Factors explaining default are loan purpose, annual income, current housing situation, credit history and indebtedness. Secondly, a logistic regression model is developed to predict defaults. The grade assigned by the P2P lending site is the most predictive factor of default, but the accuracy of the model is improved by adding other information, especially the borrower's debt level. PMID:26425854

  13. Yes we can! Eliminating health disparities as part of the core business of nursing on a global level.

    PubMed

    Villeneuve, Michael J

    2008-11-01

    Nurses in the 21st century are being called to rise to new levels of practice, including a more influential leadership at senior levels of policy development. Decades of research, good will, and a revolutionary civil rights movement have not resolved the world's staggering health outcome disparities. Nursing has a solution: Many of the most troubling disparities are amenable to effective intervention by the world's nurses through their clinical and policy work. The author challenges nurses to imagine the impact on global health if the elimination of disparities is the core goal of nursing for the 21st century. Moving from individuals and communities to systems levels, nurses must be versed in a range of system-level vital signs that affect policy development including economics, demographics, and access to care. Setting our sights on the elimination of health disparities offers a rallying point around which nursing can coalesce and set human health on a new and more equitable course.

  14. Yes we can! Eliminating health disparities as part of the core business of nursing on a global level.

    PubMed

    Villeneuve, Michael J

    2008-11-01

    Nurses in the 21st century are being called to rise to new levels of practice, including a more influential leadership at senior levels of policy development. Decades of research, good will, and a revolutionary civil rights movement have not resolved the world's staggering health outcome disparities. Nursing has a solution: Many of the most troubling disparities are amenable to effective intervention by the world's nurses through their clinical and policy work. The author challenges nurses to imagine the impact on global health if the elimination of disparities is the core goal of nursing for the 21st century. Moving from individuals and communities to systems levels, nurses must be versed in a range of system-level vital signs that affect policy development including economics, demographics, and access to care. Setting our sights on the elimination of health disparities offers a rallying point around which nursing can coalesce and set human health on a new and more equitable course. PMID:19074199

  15. 2p radioactivity studied by tracking technique

    SciTech Connect

    Mukha, Ivan

    2010-06-01

    The recent advance in experimental studies of short-lived exotic nuclei beyond the proton drip line is presented. In particular, in-flight decays of proton-unbound nuclei with picosecond lifetimes can be probed by a novel technique which tracks all decay products precisely, and the decay vertices as well as the angular correlations of the fragments are deduced from the measured trajectories. The corresponding pioneering experiment which identified a previously-unknown isotope {sup 19}Mg and its two-proton (2p) radioactivity as well as studied the reference 2p decay of the known isotope {sup 16}Ne is described. Systematic studies of other 2p precursors beyond the proton drip line are foreseen with this powerful technique whose sensitivity is larger by factor of 30 in comparison with a conventional invariant-mass method. The 2p radioactivity candidates {sup 30}Ar, {sup 34}Ca and {sup 26}S are discussed. Information about the respective one-proton unbound nuclei can be obtained with this technique by evaluating proton-heavy-fragment correlations. Systematic studies of nuclei beyond the proton drip line, e.g., the well-known proton resonances above the 'waiting points' in the astrophysical rp-process, {sup 69}Br and {sup 73}Br are feasible.

  16. Genome-wide Mapping of the Coactivator Ada2p Yields Insight into the Functional Roles of SAGA/ADA Complex in Candida albicans

    PubMed Central

    Sellam, Adnane; Askew, Christopher; Epp, Elias; Lavoie, Hugo; Whiteway, Malcolm

    2009-01-01

    The SAGA/ADA coactivator complex, which regulates numerous cellular processes by coordinating histone acetylation, is widely conserved throughout eukaryotes, and analysis of the Candida albicans genome identifies the components of this complex in the fungal pathogen. We investigated the multiple functions of SAGA/ADA in C. albicans by determining the genome-wide occupancy of Ada2p using chromatin immunoprecipitation (ChIP). Ada2p is recruited to 200 promoters upstream of genes involved in different stress-response functions and metabolic processes. Phenotypic and transcriptomic analysis of ada2 mutant showed that Ada2p is required for the responses to oxidative stress, as well as to treatments with tunicamycin and fluconazole. Ada2p recruitment to the promoters of oxidative resistance genes is mediated by the transcription factor Cap1p, and coactivator function were also established for Gal4p, which recruits Ada2p to the promoters of glycolysis and pyruvate metabolism genes. Cooccupancy of Ada2p and the drug resistance regulator Mrr1p on the promoters of core resistance genes characterizing drug resistance in clinical strains was also demonstrated. Ada2p recruitment to the promoters of these genes were shown to be completely dependent on Mrr1p. Furthermore, ADA2 deletion causes a decrease in H3K9 acetylation levels of target genes, thus illustrating its importance for histone acetyl transferase activity. PMID:19279142

  17. Study of muons near shower cores at sea level using the E594 neutrino detector

    NASA Technical Reports Server (NTRS)

    Goodman, J. A.; Gupta, S. C.; Freudenreich, H.; Sivaprasad, K.; Tonwar, S. C.; Yodh, G. B.; Ellsworth, R. W.; Goodman, M. C.; Bogert, D.; Burnstein, R.

    1985-01-01

    The E594 neutrino detector has been used to study the lateral distribution of muons of energy 3 GeV near shower cores. The detector consists of a 340 ton fine grain calorimeter with 400,000 cells of flash chamber and dimensions of 3.7 m x 20 m x 3.7 m (height). The average density in the calorimeter is 1.4 gm/sq cm, and the average Z is 21. The detector was triggered by four 0.6 sq m scintillators placed immediately on the top of the calorimeter. The trigger required at least two of these four counters. The accompanying extensive air showers (EAS) was sampled by 14 scintillation counters located up to 15 m from the calorimeter. Several off line cuts have been applied to the data. Demanding five particles in at least two of the trigger detectors, a total of 20 particles in all of them together, and an arrival angle for the shower 450 deg reduced the data sample to 11053 events. Of these in 4869 cases, a computer algorithm found at least three muons in the calorimeter.

  18. Core-level spectra and molecular deformation in adsorption: V-shaped pentacene on Al(001).

    PubMed

    Baby, Anu; Lin, He; Brivio, Gian Paolo; Floreano, Luca; Fratesi, Guido

    2015-01-01

    By first-principle simulations we study the effects of molecular deformation on the electronic and spectroscopic properties as it occurs for pentacene adsorbed on the most stable site of Al(001). The rationale for the particular V-shaped deformed structure is discussed and understood. The molecule-surface bond is made evident by mapping the charge redistribution. Upon X-ray photoelectron spectroscopy (XPS) from the molecule, the bond with the surface is destabilized by the electron density rearrangement to screen the core hole. This destabilization depends on the ionized carbon atom, inducing a narrowing of the XPS spectrum with respect to the molecules adsorbed hypothetically undistorted, in full agreement to experiments. When looking instead at the near-edge X-ray absorption fine structure (NEXAFS) spectra, individual contributions from the non-equivalent C atoms provide evidence of the molecular orbital filling, hybridization, and interchange induced by distortion. The alteration of the C-C bond lengths due to the V-shaped bending decreases by a factor of two the azimuthal dichroism of NEXAFS spectra, i.e., the energy splitting of the sigma resonances measured along the two in-plane molecular axes.

  19. Core-level spectra and molecular deformation in adsorption: V-shaped pentacene on Al(001)

    PubMed Central

    Lin, He; Brivio, Gian Paolo; Floreano, Luca; Fratesi, Guido

    2015-01-01

    Summary By first-principle simulations we study the effects of molecular deformation on the electronic and spectroscopic properties as it occurs for pentacene adsorbed on the most stable site of Al(001). The rationale for the particular V-shaped deformed structure is discussed and understood. The molecule–surface bond is made evident by mapping the charge redistribution. Upon X-ray photoelectron spectroscopy (XPS) from the molecule, the bond with the surface is destabilized by the electron density rearrangement to screen the core hole. This destabilization depends on the ionized carbon atom, inducing a narrowing of the XPS spectrum with respect to the molecules adsorbed hypothetically undistorted, in full agreement to experiments. When looking instead at the near-edge X-ray absorption fine structure (NEXAFS) spectra, individual contributions from the non-equivalent C atoms provide evidence of the molecular orbital filling, hybridization, and interchange induced by distortion. The alteration of the C–C bond lengths due to the V-shaped bending decreases by a factor of two the azimuthal dichroism of NEXAFS spectra, i.e., the energy splitting of the sigma resonances measured along the two in-plane molecular axes. PMID:26734516

  20. The casein kinases Yck1p and Yck2p act in the secretory pathway, in part, by regulating the Rab exchange factor Sec2p

    PubMed Central

    Stalder, Danièle; Novick, Peter J.

    2016-01-01

    Sec2p is a guanine nucleotide exchange factor that activates Sec4p, the final Rab GTPase of the yeast secretory pathway. Sec2p is recruited to secretory vesicles by the upstream Rab Ypt32p acting in concert with phosphatidylinositol-4-phosphate (PI(4)P). Sec2p also binds to the Sec4p effector Sec15p, yet Ypt32p and Sec15p compete against each other for binding to Sec2p. We report here that the redundant casein kinases Yck1p and Yck2p phosphorylate sites within the Ypt32p/Sec15p binding region and in doing so promote binding to Sec15p and inhibit binding to Ypt32p. We show that Yck2p binds to the autoinhibitory domain of Sec2p, adjacent to the PI(4)P binding site, and that addition of PI(4)P inhibits Sec2p phosphorylation by Yck2p. Loss of Yck1p and Yck2p function leads to accumulation of an intracellular pool of the secreted glucanase Bgl2p, as well as to accumulation of Golgi-related structures in the cytoplasm. We propose that Sec2p is phosphorylated after it has been recruited to secretory vesicles and the level of PI(4)P has been reduced. This promotes Sec2p function by stimulating its interaction with Sec15p. Finally, Sec2p is dephosphorylated very late in the exocytic reaction to facilitate recycling. PMID:26700316

  1. [VIEW Level, Special Education Core Curriculum Manual.] I.E.P. Development Guide.

    ERIC Educational Resources Information Center

    Bergen County Region III, Demerest, NJ. Div. of Special Education.

    The Individualized Educational Program development guide is intended for handicapped students at the VIEW level (Vocational Instruction and Experience Workshop). Goals, objectives, and activities are specified for each of seven categories (sample subsections in parentheses): (1) assembly skills (collating, sorting, filing, folding); (2)…

  2. The Special Education Core Curriculum Manual: Competency Level -- Communication Skills, Mathematics, Life Skills, and Study Skills.

    ERIC Educational Resources Information Center

    Margolis, Leonard; And Others

    The manual is intended to provide basic objectives and teaching strategies for teachers of handicapped children at the upper elementary and secondary level in the areas of communication, mathematics, life skills, and study skills. Each subject area is divided into sub-sections under which learning objectives and associated teaching activities are…

  3. Energies and E1, M1, E2, and M2 transition rates for states of the 2s22p3, 2s2p4, and 2p5 configurations in nitrogen-like ions between F III and Kr XXX

    NASA Astrophysics Data System (ADS)

    Rynkun, P.; Jönsson, P.; Gaigalas, G.; Froese Fischer, C.

    2014-03-01

    Based on relativistic wavefunctions from multiconfiguration Dirac-Hartree-Fock and configuration interaction calculations, E1, M1, E2, and M2 transition rates, weighted oscillator strengths, and lifetimes are evaluated for the states of the (1s2)2s22p3,2s2p4, and 2p5 configurations in all nitrogen-like ions between F III and Kr XXX. The wavefunction expansions include valence, core-valence, and core-core correlation effects through single-double multireference expansions to increasing sets of active orbitals. The computed energies agree very well with experimental values, with differences of only 300-600 cm-1 for the majority of the levels and ions in the sequence. Computed transitions rates are in close agreement with available data from MCHF-BP calculations by Tachiev and Froese Fischer [G.I. Tachiev, C. Froese Fischer, A&A 385 (2002) 716].

  4. Surface effects on core-level binding energies and valence in thulium chalcogenides

    NASA Astrophysics Data System (ADS)

    Kaindl, G.; Laubschat, C.; Reihl, B.; Pollak, R. A.; Mårtensson, N.; Holtzberg, F.; Eastman, D. E.

    1982-08-01

    Vacuum-cleaved (100) surfaces of mixed-valent TmSe, divalent TmTe, and trivalent TmS were studied by high-resolution, angle-integrated photoelectron spectroscopy with the use of synchrotron radiation in the energy range 30<=hν<=110 eV. In the topmost surface layers of TmSe and TmTe the 4f levels are found to be shifted to higher binding energies by 0.32+/-0.04 and 0.41+/-0.05 eV, respectively. In both TmSe and TmS the topmost surface layers are divalent. In the case of TmSe a separation of the Tm2+ 4f12 spectral feature into surface and bulk contributions allows a determination of the bulk mean valence v¯=2.55+/-0.05. While a shift of the Se 3d levels to lower binding energy is observed for Se atoms in the topmost surface layer of TmSe, no such shift can be resolved for the Te 4d levels of TmTe. The surface-derived divalent spectral features can be quenched completely in all three cases by exposure of the surfaces to submonolayer amounts of oxygen, resulting in the formation of trivalent surface oxides. Values for the electron mean free path l are derived from the observed surface- and bulk-spectral intensities, with l decreasing with decreasing electron kinetic energy down to ≅45 eV. Smaller singularity indices α of the Doniach-Sunjić line shapes as well as smaller extrinsic losses are observed for photoemission from the divalent surface layers as compared to the bulk.

  5. The core and conserved role of MAL is homeostatic regulation of actin levels.

    PubMed

    Salvany, Lara; Muller, Julius; Guccione, Ernesto; Rørth, Pernille

    2014-05-15

    The transcription cofactor MAL is regulated by free actin levels and thus by actin dynamics. MAL, together with its DNA-binding partner, SRF, is required for invasive cell migration and in experimental metastasis. Although MAL/SRF has many targets, we provide genetic evidence in both Drosophila and human cellular models that actin is the key target that must be regulated by MAL/SRF for invasive cell migration. By regulating MAL/SRF activity, actin protein feeds back on production of actin mRNA to ensure sufficient supply of actin. This constitutes a dedicated homeostatic feedback system that provides a foundation for cellular actin dynamics.

  6. Core level regulatory network of osteoblast as molecular mechanism for osteoporosis and treatment

    PubMed Central

    Zhu, Xiaomei; Li, Jun; Liang, Yuhong; Liu, Tao; Zhu, Yanxia; Zhang, Bingbing; Tan, Shuang; Guo, Huajie; Guan, Shuguang; Ao, Ping; Zhou, Guangqian

    2016-01-01

    To develop and evaluate the long-term prophylactic treatment for chronic diseases such as osteoporosis requires a clear view of mechanism at the molecular and systems level. While molecular signaling pathway studies for osteoporosis are extensive, a unifying mechanism is missing. In this work, we provide experimental and systems-biology evidences that a tightly connected top-level regulatory network may exist, which governs the normal and osteoporotic phenotypes of osteoblast. Specifically, we constructed a hub-like interaction network from well-documented cross-talks among estrogens, glucocorticoids, retinoic acids, peroxisome proliferator-activated receptor, vitamin D receptor and calcium-signaling pathways. The network was verified with transmission electron microscopy and gene expression profiling for bone tissues of ovariectomized (OVX) rats before and after strontium gluconate (GluSr) treatment. Based on both the network structure and the experimental data, the dynamical modeling predicts calcium and glucocorticoids signaling pathways as targets for GluSr treatment. Modeling results further reveal that in the context of missing estrogen signaling, the GluSr treated state may be an outcome that is closest to the healthy state. PMID:26783964

  7. Core level regulatory network of osteoblast as molecular mechanism for osteoporosis and treatment.

    PubMed

    Yuan, Ruoshi; Ma, Shengfei; Zhu, Xiaomei; Li, Jun; Liang, Yuhong; Liu, Tao; Zhu, Yanxia; Zhang, Bingbing; Tan, Shuang; Guo, Huajie; Guan, Shuguang; Ao, Ping; Zhou, Guangqian

    2016-01-26

    To develop and evaluate the long-term prophylactic treatment for chronic diseases such as osteoporosis requires a clear view of mechanism at the molecular and systems level. While molecular signaling pathway studies for osteoporosis are extensive, a unifying mechanism is missing. In this work, we provide experimental and systems-biology evidences that a tightly connected top-level regulatory network may exist, which governs the normal and osteoporotic phenotypes of osteoblast. Specifically, we constructed a hub-like interaction network from well-documented cross-talks among estrogens, glucocorticoids, retinoic acids, peroxisome proliferator-activated receptor, vitamin D receptor and calcium-signaling pathways. The network was verified with transmission electron microscopy and gene expression profiling for bone tissues of ovariectomized (OVX) rats before and after strontium gluconate (GluSr) treatment. Based on both the network structure and the experimental data, the dynamical modeling predicts calcium and glucocorticoids signaling pathways as targets for GluSr treatment. Modeling results further reveal that in the context of missing estrogen signaling, the GluSr treated state may be an outcome that is closest to the healthy state. PMID:26783964

  8. Core-level spectroscopy investigation of the Mo{sub 0.75}Re{sub 0.25}(100) surface

    SciTech Connect

    Lyman, P.F.; Zehner, D.M.

    1993-10-01

    Preferential surface segregation in the Mo{sub 0.75}(100) surface region was investigated using high-resolution core-level spectroscopy with synchrotron radiation. The magnitude and direction of the surface core-level shifts observed in this study can be qualitatively understood by comparison to W and Mo core-level shifts. Measured core-level intensities are found to be consistent with the segregation of Mo to the surface of the alloy, with an enrichment of Re in the second layer (as found in previous investigations). It is inferred that both Tc and Os will segregate to the Mo{sub 0.75}Re{sub 0.25}(100) surface.

  9. A Novel Syndrome Affecting Multiple Mitochondrial Functions, Located by Microcell-Mediated Transfer to Chromosome 2p14-2p13

    PubMed Central

    Seyda, Agnieszka; Newbold, Robert F.; Hudson, Thomas J.; Verner, Andrei; MacKay, Neviana; Winter, Susan; Feigenbaum, Annette; Malaney, Suzann; Gonzalez-Halphen, Diego; Cuthbert, Andrew P.; Robinson, Brian H.

    2001-01-01

    We have studied cultured skin fibroblasts from three siblings and one unrelated individual, all of whom had fatal mitochondrial disease manifesting soon after birth. After incubation with 1 mM glucose, these four cell strains exhibited lactate/pyruvate ratios that were six times greater than those of controls. On further analysis, enzymatic activities of the pyruvate dehydrogenase complex, the 2-oxoglutarate dehydrogenase complex, NADH cytochrome c reductase, succinate dehydrogenase, and succinate cytochrome c reductase were severely deficient. In two of the siblings the enzymatic activity of cytochrome oxidase was mildly decreased (by ∼50%). Metabolite analysis performed on urine samples taken from these patients revealed high levels of glycine, leucine, valine, and isoleucine, indicating abnormalities of both the glycine-cleavage system and branched-chain α-ketoacid dehydrogenase. In contrast, the activities of fibroblast pyruvate carboxylase, mitochondrial aconitase, and citrate synthase were normal. Immunoblot analysis of selected complex III subunits (core 1, cyt c1, and iron-sulfur protein) and of the pyruvate dehydrogenase complex subunits revealed no visible changes in the levels of all examined proteins, decreasing the possibility that an import and/or assembly factor is involved. To elucidate the underlying molecular defect, analysis of microcell-mediated chromosome-fusion was performed between the present study's fibroblasts (recipients) and a panel of A9 mouse:human hybrids (donors) developed by Cuthbert et al. (1995). Complementation was observed between the recipient cells from both families and the mouse:human hybrid clone carrying human chromosome 2. These results indicate that the underlying defect in our patients is under the control of a nuclear gene, the locus of which is on chromosome 2. A 5-cM interval has been identified as potentially containing the critical region for the unknown gene. This interval maps to region 2p14-2p13. PMID

  10. Multi-configuration Dirac-Hartree-Fock calculations of the transition rates of 2s22p2 - 2s2p3 and 2s2p3 - 2s22pnl (n ≥ 3) E1 transitions of N+

    NASA Astrophysics Data System (ADS)

    Shen, Xiaozhi; Liu, Juan; Zhou, Fuyang

    2016-10-01

    Wavefunctions were determined using the multi-configuration Dirac-Hartree-Fock method. The core-core, core-valence, valence correlation, Breit interaction and quantum electrodynamics effects, as well as some higher-order correlation effects, were considered to obtain accurate wavelengths (λ), oscillator strengths (gf) and transition rates (A) of 2s22p2 - 2s2p3, 2s2p3 - 2s22pnl (n ≥ 3) and 2s2p3 - 2s2p23s E1 transitions. The branching ratio of 2s2p3 5S^o_2 (namely Aλ2143.45/Aλ2139.68) based on the latest calculation of 2.462 ± 0.119 is recommended for the determination of a nebula's electron temperature and electron density. The largest calculated gf value of 2s2p3 - 2s22p4p is λ630.65, differing from that of λ1060.2 (i.e. 2s2p3 3P^o_2 - 2s22p4p 3S1) that was observed with the largest intensities in the Orion Nebula spectrum. In addition, the energy levels and the splittings of 2s2p3, the extremely difficult calculations of the rates of two-electron one-photon transitions as well as those of the very small intercombination A of 2s2p3 5S^o_2 were studied in detail. Because of the weak spin-orbit interaction, accurately calculating the levels 3P^o_{1,2,0} (or 3D^o_{3,2,1}) and their transition matrix elements is very sensitive to relativistic and electron correlation effects. A special case for this is when the transition operators synchronously applied to wavefunctions with regard to 2s2p3 3Po and 2s22pnl (n = 4) become extremely sensitive to some higher-order correlation effects.

  11. Evidence of the nature of core-level photoemission satellites using angle-resolved photoemission extended fine structure

    SciTech Connect

    Moler, E.J.; Kellar, S.A.; Huff, W.R.A.

    1997-04-01

    The authors present a unique method of experimentally determining the angular momentum and intrinsic/extrinsic origin of core-level photoemission satellites by examining the satellite diffraction pattern in the Angle Resolved Photoemission Extended Fine Structure (ARPEFS) mode. They show for the first time that satellite peaks not associated with chemically differentiated atomic species display an ARPEFS intensity oscillation. They present ARPEFS data for the carbon 1s from ({radical}3x{radical}3)R30 CO/Cu(111) and p2mg(2xl)CO/Ni(110), nitrogen 1s from c(2x2) N{sub 2}/Ni(100), cobalt 1s from p(1x1)Co/Cu(100), and nickel 3p from clean nickel (111). The satellite peaks and tails of the Doniach-Sunjic line shapes in all cases exhibit ARPEFS curves which indicate an angular momentum identical to the main peak and are of an intrinsic nature.

  12. Electron capture by a metastable ion in the collision Ar8+(2p53s)3P0,2+H2 at low velocity

    NASA Astrophysics Data System (ADS)

    Bliman, S.; Cornille, M.; Huber, B. A.; Nordgren, J.; Rubensson, J. E.

    2001-03-01

    Single-electron (SC) and double-electron capture (DC) in collisions of metastable Ar8+ ions with H2 have been studied by using X-VUV and Auger spectroscopy at 10 keV per charge. SC by the long-lived metastable ion Ar8+(2p53s)3P0.2 mostly populates inner-shell excited Na-like Ar7+**[(2p53s)3P,nl]2.4Lj levels with n=5, a small fraction going to n=4. With the use of radiative and Auger decay rates, the observed X-VUV and Auger spectra are analyzed and compared with the spectra obtained by other authors. It is shown that the stabilization of these core-excited states is both radiative and autoionizing. DC by the metastable projectile reveals the formation of triply excited Ar6+*** ions. They stabilize along two Auger decay steps: the first one gives a low-energy electron, associated with the decay to the intermediate continua Ar7+(2p53l3l'), while the second step-originating from these Ar7+(2p53l3l') levels-gives a higher-energy electron, characteristic of the decay to the only available continuum Ar8+(2p6)1S0.

  13. Adsorption and dissociation of acidic trace gases on ice surfaces - caught in the act with core level spectroscopy

    NASA Astrophysics Data System (ADS)

    Waldner, Astrid; Orlando, Fabrizio; Ammann, Markus; Kleibert, Armin; Huthwelker, Thomas; Peter, Thomas; Bartels-Rausch, Thorsten

    2015-04-01

    Chemistry and physical processes in Earth's ice and snow cover can change the composition of the atmosphere and the contaminant content of the cryosphere. They have thus direct impacts on geochemical cycles and the climate system. Our ability to predict the fate of chemicals in snow or air masses in exchange with the cryosphere on a regional scale or to model those in snow chemistry models is currently hampered by our limited understanding of the underlying mechanisms on a molecular level. So far, direct experimental observations under environmentally relevant conditions of the ice surface and of the adsorption of trace gases to it are very limited. The unique approach of this study is to combine two surface sensitive spectroscopic methods to directly probe the hydrogen-bonding network at the ice surface ( ~1 nm depth) and the concentration, depth profile (~1 to 10 nm), and dissociation degree of the dopant. We present first core-electron photoemission (XPS) and partial electron yield X-ray absorption (NEXAFS) measurements of formic acid adsorbed to ice at 240 K. The analysis of oxygen NEXAFS spectra reveals information on changes in the hydrogen-bonding network of the ice surface upon adsorption of formic acid. Depth profiles based on XPS measurements indicate that the adsorbed acid stays at the ice surface. Furthermore we obtained a preliminary estimation of the degree of formic acid dissociation at the ice surface. Results are compared to earlier core-electron studies of several trace gases adsorbed to ice at 240 K and compared to results from more traditional method to and snow to reveal fundamental aspects of the ice surface and how it interacts with dopants. Even with the focus on adsorption of acidic trace gases to ice, results of this study will thus be of high relevance also for other chemical processes in ice and snow. This is of interest not only in environmental science but also in material science, cryobiology, and astrophysics.

  14. In-fiber liquid-level probe based on Michelson interferometer via dual-mode elliptical multilayer-core fiber

    NASA Astrophysics Data System (ADS)

    Liang, Xiao; Ren, Guobin; Li, Yang; Liu, Zhibo; Wei, Huai; Jian, Shuisheng

    2016-07-01

    An in-fiber liquid-level probe fabricated from homemade dual-mode elliptical multilayer-core fiber (EMCF) was proposed and experimentally demonstrated. The proposed sensor simply consists of a segment of the EMCF with one end coated with silver film, and a Michelson interferometer is roughly established when light from single-mode fiber incident from the other end. The detected interference patterns, rather clean due to the few-mode property, shift as the liquid level due to strong interaction between high-order modes and measurands through evanescent waves. Both the propagation characteristics and operation principle of such a sensor were demonstrated in detail, and sensitivities of 33.48, 43.35, and 48.93 pm/mm corresponding to liquid indices of 1.333, 1.353, and 1.373 were successfully achieved with a 50-mm EMCF probe, respectively. Moreover, the proposed sensor had the potential to discriminate measurand index after proper calibration.

  15. Engineering task plan for the development, fabrication and installation of rotary mode core sample truck grapple hoist box level wind system

    SciTech Connect

    BOGER, R.M.

    1999-05-12

    This Engineering Task Plan is to design, generate fabrication drawings, fabricate, test, and install the grapple hoist level wind system for Rotary Mode Core Sample Trucks (RMCST) 3 and 4. Deliverables will include generating fabrication drawings, fabrication of one level wind system, updating fabrication drawings as required, and installation of level wind systems on RMCST 3 or 4. The installation of the level wind systems will be done during a preventive maintenance outage.

  16. Three-Year Outcomes of Transcatheter Aortic Valve Implantation in Patients With Varying Levels of Surgical Risk (from the CoreValve ADVANCE Study).

    PubMed

    Barbanti, Marco; Schiltgen, Molly; Verdoliva, Sarah; Bosmans, Johan; Bleiziffer, Sabine; Gerckens, Ulrich; Wenaweser, Peter; Brecker, Stephen; Gulino, Simona; Tamburino, Corrado; Linke, Axel

    2016-03-01

    This study compared 3-year clinical outcomes of patients who underwent transcatheter aortic valve implantation with the Society of Thoracic Surgeons (STS) score ≤7% to those of patients with a score >7%. Data were drawn from the ADVANCE study, a multinational post-market clinical trial that enrolled real-world patients with severe aortic stenosis treated with the CoreValve bioprosthesis. Events were independently adjudicated using Valve Academic Research Consortium-1 definitions. A total of 996 patients were implanted: STS ≤7% (n = 697, median STS 4.3%, interquartile range 3.1% to 5.4%) and STS >7% (n = 298, median STS 9.7%, interquartile range 8.0% to 12.4%). At 3 years, the STS ≤7% group had lower rates of all-cause mortality (28.6 vs 45.9, p <0.01) and cardiovascular mortality (19.0 vs 30.2, p <0.01) than the STS >7% group. No differences were observed in cerebrovascular accidents, vascular complications, bleeding, or myocardial infarction. In patients with STS ≤7%, mortality at 3 years was higher in those with moderate or severe aortic regurgitation (AR) at discharge than in those with mild or less AR (39.9% vs 22.9%; hazard ratio 1.98; 95% confidence interval 1.37 to 2.86; p <0.01). Conversely, the severity of AR at discharge did not affect 3-year mortality in patients with STS >7% (42.9% vs 44.6%, moderate/severe vs mild/less; hazard ratio 1.04; 95% confidence interval, 0.62 to 1.75; p = 0.861; p for interaction = 0.047). In conclusion, patients with STS ≤7% had lower rates of all-cause and cardiovascular mortality at 3 years after transcatheter aortic valve implantation. Complication rates were low and stable in both groups, demonstrating the safety of this procedure for patients at various levels of surgical risk.

  17. Three-Year Outcomes of Transcatheter Aortic Valve Implantation in Patients With Varying Levels of Surgical Risk (from the CoreValve ADVANCE Study).

    PubMed

    Barbanti, Marco; Schiltgen, Molly; Verdoliva, Sarah; Bosmans, Johan; Bleiziffer, Sabine; Gerckens, Ulrich; Wenaweser, Peter; Brecker, Stephen; Gulino, Simona; Tamburino, Corrado; Linke, Axel

    2016-03-01

    This study compared 3-year clinical outcomes of patients who underwent transcatheter aortic valve implantation with the Society of Thoracic Surgeons (STS) score ≤7% to those of patients with a score >7%. Data were drawn from the ADVANCE study, a multinational post-market clinical trial that enrolled real-world patients with severe aortic stenosis treated with the CoreValve bioprosthesis. Events were independently adjudicated using Valve Academic Research Consortium-1 definitions. A total of 996 patients were implanted: STS ≤7% (n = 697, median STS 4.3%, interquartile range 3.1% to 5.4%) and STS >7% (n = 298, median STS 9.7%, interquartile range 8.0% to 12.4%). At 3 years, the STS ≤7% group had lower rates of all-cause mortality (28.6 vs 45.9, p <0.01) and cardiovascular mortality (19.0 vs 30.2, p <0.01) than the STS >7% group. No differences were observed in cerebrovascular accidents, vascular complications, bleeding, or myocardial infarction. In patients with STS ≤7%, mortality at 3 years was higher in those with moderate or severe aortic regurgitation (AR) at discharge than in those with mild or less AR (39.9% vs 22.9%; hazard ratio 1.98; 95% confidence interval 1.37 to 2.86; p <0.01). Conversely, the severity of AR at discharge did not affect 3-year mortality in patients with STS >7% (42.9% vs 44.6%, moderate/severe vs mild/less; hazard ratio 1.04; 95% confidence interval, 0.62 to 1.75; p = 0.861; p for interaction = 0.047). In conclusion, patients with STS ≤7% had lower rates of all-cause and cardiovascular mortality at 3 years after transcatheter aortic valve implantation. Complication rates were low and stable in both groups, demonstrating the safety of this procedure for patients at various levels of surgical risk. PMID:26762727

  18. O- and H-induced surface core level shifts on Ru(0001): prevalence of the additivity rule

    NASA Astrophysics Data System (ADS)

    Lizzit, S.; Zhang, Y.; Kostov, K. L.; Petaccia, L.; Baraldi, A.; Menzel, D.; Reuter, K.

    2009-04-01

    In previous work on adsorbate-induced surface core level shifts (SCLSs), the effects caused by O atom adsorption on Rh(111) and Ru(0001) were found to be additive: the measured shifts for first-layer Ru atoms depended linearly on the number of directly coordinated O atoms. Density-functional theory calculations quantitatively reproduced this effect, allowed separation of initial- and final-state contributions, and provided an explanation in terms of a roughly constant charge transfer per O atom. We have now conducted similar measurements and calculations for three well-defined adsorbate and coadsorbate layers containing O and H atoms: (1 × 1)-H, (2 × 2)-(O+H) and (2 × 2)-(O+3H) on Ru(0001). As H is stabilized in fcc sites in the prior two structures and in hcp sites in the latter, this enables us to not only study coverage and coadsorption effects on the adsorbate-induced SCLSs, but also the sensitivity to similar adsorption sites. Remarkably good agreement is obtained between experiment and calculations for the energies and geometries of the layers, as well as for all aspects of the SCLS values. The additivity of the next-neighbor adsorbate-induced SCLSs is found to prevail even for the coadsorbate structures. While this confirms the suggested use of SCLSs as fingerprints of the adsorbate configuration, their sensitivity is further demonstrated by the slightly different shifts unambiguously determined for H adsorption in either fcc or hcp hollow sites.

  19. Ce Core-Level Spectroscopy, and Magnetic and Electrical Transport Properties of Lightly Ce-Doped YCoO3

    NASA Astrophysics Data System (ADS)

    Kobayashi, Yoshihiko; Koike, Tsuyoshi; Okawa, Mario; Takayanagi, Ryohei; Takei, Shohei; Minohara, Makoto; Kobayashi, Masaki; Horiba, Koji; Kumigashira, Hiroshi; Yasui, Akira; Ikenaga, Eiji; Saitoh, Tomohiko; Asai, Kichizo

    2016-11-01

    We have investigated the Ce and Co core level spectroscopy, and the magnetic and electrical transport properties of lightly Ce-doped YCoO3. We have successfully synthesized single-phase Y1-xCexCoO3 for 0.0 ≤ x ≤ 0.1 by the sol-gel method. Hard X-ray photoelectron and X-ray absorption spectroscopy experiments reveal that the introduced Ce ions are tetravalent, which is considered to be the first case of electron doping into bulk trivalent Co oxides with perovskite RECoO3 (RE: rare-earth element or Y) caused by RE site substitution. The magnitude of the effective magnetic moment peff obtained from the temperature dependence of magnetic susceptibility χ(T) at higher temperatures is close to that for high-spin Co2+ introduced by the Ce doping, implying that the electrons doped into the Co site induce Co2+ with a high-spin state. For x = 0.1, ferromagnetic ordering is observed below about 7 K. Electrical transport properties such as resistivity and thermoelectric power show that negative electron-like carriers are introduced by Ce substitution.

  20. Energies and E1, M1, E2, and M2 transition rates for states of the 2s{sup 2}2p{sup 3}, 2s2p{sup 4}, and 2p{sup 5} configurations in nitrogen-like ions between F III and Kr XXX

    SciTech Connect

    Rynkun, P.; Jönsson, P.; Gaigalas, G.; Froese Fischer, C.

    2014-03-15

    Based on relativistic wavefunctions from multiconfiguration Dirac–Hartree–Fock and configuration interaction calculations, E1, M1, E2, and M2 transition rates, weighted oscillator strengths, and lifetimes are evaluated for the states of the (1s{sup 2})2s{sup 2}2p{sup 3},2s2p{sup 4}, and 2p{sup 5} configurations in all nitrogen-like ions between F III and Kr XXX. The wavefunction expansions include valence, core–valence, and core–core correlation effects through single–double multireference expansions to increasing sets of active orbitals. The computed energies agree very well with experimental values, with differences of only 300–600 cm{sup −1} for the majority of the levels and ions in the sequence. Computed transitions rates are in close agreement with available data from MCHF-BP calculations by Tachiev and Froese Fischer [G.I. Tachiev, C. Froese Fischer, A and A 385 (2002) 716].

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

    DOE R&D Accomplishments Database

    Chu, S.

    1976-10-01

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

  2. Double photoionization of helium from the 1s2p {}^{3}{\\rm{P}} excited state

    NASA Astrophysics Data System (ADS)

    Li, Y.; Pindzola, M. S.; Colgan, J.

    2016-10-01

    Time-dependent close-coupling (TDCC) calculations are carried out for the double photoionization of Helium in the 1{{s}}2{{p}}{}3{{P}} excited state. TDCC {l}1{l}2L results are presented for the total and energy differential cross sections for the 1{{s}}2{{p}}{}3{{P}} term. TDCC {l}1{j}1{l}2{j}2J results are presented for the total and energy differential cross sections for the 1{{s}}2{{p}}{}3{{{P}}}{0,1,2} levels. Differences found between the level resolved double photoionization cross sections are due to varying degrees of continuum correlation found in the outgoing two electrons.

  3. Chemical bonding and charge redistribution - Valence band and core level correlations for the Ni/Si, Pd/Si, and Pt/Si systems

    NASA Technical Reports Server (NTRS)

    Grunthaner, P. J.; Grunthaner, F. J.; Madhukar, A.

    1982-01-01

    Via a systematic study of the correlation between the core and valence level X-ray photoemission spectra, the nature of the chemical bonding and charge redistribution for bulk transition metal silicides has been examined. Particular emphasis is placed on Pt2Si and PtSi. It is observed that the strength of the metal (d)-silicon (p) interaction increases in the order Ni2Si, Pd2Si, Pt2Si. It is also observed that both the metal and silicon core lines shift to higher binding energy as the silicides are formed. The notion of charge redistribution for metallic bonds is invoked to explain these data.

  4. Deduction of the chemical state and the electronic structure of Nd{sub 2}Fe{sub 14}B compound from X-ray photoelectron spectroscopy core-level and valence-band spectra

    SciTech Connect

    Wang, Jing; Liang, Le; Zhang, Lanting E-mail: lmsun@sjtu.edu.cn; Sun, Limin E-mail: lmsun@sjtu.edu.cn; Hirano, Shinichi

    2014-10-28

    Characterization of chemical state and electronic structure of the technologically important Nd{sub 2}Fe{sub 14}B compound is attractive for understanding the physical nature of its excellent magnetic properties. X-ray photoelectron spectroscopy (XPS) study of such rare-earth compound is important and also challenging due to the easy oxidation of surface and small photoelectron cross-sections of rare-earth 4f electrons and B 2p electrons, etc. Here, we reported an investigation based on XPS spectra of Nd{sub 2}Fe{sub 14}B compound as a function of Ar ion sputtering time. The chemical state of Fe and that of B in Nd{sub 2}Fe{sub 14}B compound can be clearly determined to be 0 and −3, respectively. The Nd in Nd{sub 2}Fe{sub 14}B compound is found to have the chemical state of close to +3 instead of +3 as compared with the Nd in Nd{sub 2}O{sub 3}. In addition, by comparing the valence-band spectrum of Nd{sub 2}Fe{sub 14}B compound to that of the pure Fe, the contributions from Nd, Fe, and B to the valence-band structure of Nd{sub 2}Fe{sub 14}B compound is made more clear. The B 2p states and B 2s states are identified to be at ∼11.2 eV and ∼24.6 eV, respectively, which is reported for the first time. The contribution from Nd 4f states can be identified both in XPS core-level spectrum and XPS valence-band spectrum. Although Nd 4f states partially hybridize with Fe 3d states, Nd 4f states are mainly localized in Nd{sub 2}Fe{sub 14}B compound.

  5. High Level Analysis, Design and Validation of Distributed Mobile Systems with CoreASM

    NASA Astrophysics Data System (ADS)

    Farahbod, R.; Glässer, U.; Jackson, P. J.; Vajihollahi, M.

    System design is a creative activity calling for abstract models that facilitate reasoning about the key system attributes (desired requirements and resulting properties) so as to ensure these attributes are properly established prior to actually building a system. We explore here the practical side of using the abstract state machine (ASM) formalism in combination with the CoreASM open source tool environment for high-level design and experimental validation of complex distributed systems. Emphasizing the early phases of the design process, a guiding principle is to support freedom of experimentation by minimizing the need for encoding. CoreASM has been developed and tested building on a broad scope of applications, spanning computational criminology, maritime surveillance and situation analysis. We critically reexamine here the CoreASM project in light of three different application scenarios.

  6. 2p-2p decay of {sup 8}C and isospin-allowed 2p decay of the isobaric-analog state in {sup 8}B

    SciTech Connect

    Charity, R. J.; Elson, J. M.; Manfredi, J.; Shane, R.; Sobotka, L. G.; Chajecki, Z.; Coupland, D.; Iwasaki, H.; Kilburn, M.; Lee, Jenny; Lynch, W. G.; Sanetullaev, A.; Tsang, M. B.; Winkelbauer, J.; Youngs, M.; Marley, S. T.; Shetty, D. V.; Wuosmaa, A. H.; Ghosh, T. K.

    2010-10-15

    {sup 8}C is found to decay to four protons and an {alpha} particle in two 2p emission steps. The correlations between the protons in the first step ({sup 8}C to {sup 6}Be) exhibit a significant enhancement in the region of the decay phase space where the two protons have small relative energy, a region sometimes called the diproton region. The decay of the isobaric analog of {sup 8}C in {sup 8}B is also found to decay by 2p emission. This is the first case of isospin-allowed 2p decay between isobaric analog states.

  7. Unified interpretation of Hund's first and second rules for 2p and 3p atoms.

    PubMed

    Oyamada, Takayuki; Hongo, Kenta; Kawazoe, Yoshiyuki; Yasuhara, Hiroshi

    2010-10-28

    A unified interpretation of Hund's first and second rules for 2p (C, N, O) and 3p (Si, P, S) atoms is given by Hartree-Fock (HF) and multiconfiguration Hartree-Fock (MCHF) methods. Both methods exactly satisfy the virial theorem, in principle, which enables one to analyze individual components of the total energy E(=T+V(en)+V(ee)), where T, V(en), and V(ee) are the kinetic, the electron-nucleus attraction, and the electron-electron repulsion energies, respectively. The correct interpretation for each of the two rules can only be achieved under the condition of the virial theorem 2T+V=0 by investigating how V(en) and V(ee) interplay to attain the lower total potential energy V(=V(en)+V(ee)). The stabilization of the more stable states for all the 2p and 3p atoms is ascribed to a greater V(en) that is caused by contraction of the valence orbitals accompanied with slight expansion of the core orbitals. The contraction of the valence orbitals for the two rules is a consequence of reducing the Hartree screening of the nucleus at short interelectronic distances. The reduced screening in the first rule is due to a greater amount of Fermi hole contributions in the state with the highest total spin-angular momentum S. The reduced screening in the second rule is due to the fact that two valence electrons are more likely to be on opposite sides of the nucleus in the state with the highest total orbital-angular momentum L. For each of the two rules, the inclusion of correlation does not qualitatively change the HF interpretation, but HF overestimates the energy difference ∣ΔE∣ between two levels being compared. The magnitude of the correlation energy is significantly larger for the lower L states than for the higher L states since two valence electrons in the lower L states are less likely to be on opposite sides of the nucleus. The MCHF evaluation of ∣ΔE∣ is in excellent agreement with experiment. The present HF and MCHF calculations demonstrate the above statements

  8. Unified interpretation of Hund's first and second rules for 2p and 3p atoms.

    PubMed

    Oyamada, Takayuki; Hongo, Kenta; Kawazoe, Yoshiyuki; Yasuhara, Hiroshi

    2010-10-28

    A unified interpretation of Hund's first and second rules for 2p (C, N, O) and 3p (Si, P, S) atoms is given by Hartree-Fock (HF) and multiconfiguration Hartree-Fock (MCHF) methods. Both methods exactly satisfy the virial theorem, in principle, which enables one to analyze individual components of the total energy E(=T+V(en)+V(ee)), where T, V(en), and V(ee) are the kinetic, the electron-nucleus attraction, and the electron-electron repulsion energies, respectively. The correct interpretation for each of the two rules can only be achieved under the condition of the virial theorem 2T+V=0 by investigating how V(en) and V(ee) interplay to attain the lower total potential energy V(=V(en)+V(ee)). The stabilization of the more stable states for all the 2p and 3p atoms is ascribed to a greater V(en) that is caused by contraction of the valence orbitals accompanied with slight expansion of the core orbitals. The contraction of the valence orbitals for the two rules is a consequence of reducing the Hartree screening of the nucleus at short interelectronic distances. The reduced screening in the first rule is due to a greater amount of Fermi hole contributions in the state with the highest total spin-angular momentum S. The reduced screening in the second rule is due to the fact that two valence electrons are more likely to be on opposite sides of the nucleus in the state with the highest total orbital-angular momentum L. For each of the two rules, the inclusion of correlation does not qualitatively change the HF interpretation, but HF overestimates the energy difference ∣ΔE∣ between two levels being compared. The magnitude of the correlation energy is significantly larger for the lower L states than for the higher L states since two valence electrons in the lower L states are less likely to be on opposite sides of the nucleus. The MCHF evaluation of ∣ΔE∣ is in excellent agreement with experiment. The present HF and MCHF calculations demonstrate the above statements

  9. Pseudogene CYP4Z2P 3′UTR promotes angiogenesis in breast cancer

    SciTech Connect

    Zheng, Lufeng; Li, Xiaoman; Gu, Yi; Ma, Yihua; Xi, Tao

    2014-10-24

    Highlights: • A new critical role of pseudogene CYP4Z2P 3′UTR in breast cancer is proposed. • We examine the level of pseudogene CYP4Z2P 3′UTR in breast cancer tissues. • The functions of CYP4Z2P 3′UTR and mechanism were studied. • The mechanism provides new insights for the breast cancer progression. - Abstract: Pseudogenes have long been marked as “false” genes, which are similar with real genes but have no apparent function. The 3′UTR is well-known to regulate gene expression post-transcriptionally. Our recent evidence, however, indicates novel functional roles of pseudogene CYP4Z2P 3′UTR (Z2P-UTR). We found that ectopic expression of Z2P-UTR in breast cancer cells significantly increased the expression of VEGF-A without affecting cell proliferation in vitro. Meanwhile, conditioned medium (CM) from Z2P-UTR overexpression cells enhanced proliferation, migration and tube formation of HUVEC, and promoted angiogenesis in ex vivo models. Also, CM increased the expression of VEGFR2 in HUVEC. Our data suggest that Z2P-UTR can promote breast cancer angiogenesis partly via paracrine pathway of VEGF-A/VEGFR2.

  10. Preservice Secondary Teachers Perceptions of College-Level Mathematics Content Connections with the Common Core State Standards for Mathematics

    ERIC Educational Resources Information Center

    Olson, Travis A.

    2016-01-01

    Preservice Secondary Mathematics Teachers (PSMTs) were surveyed to identify if they could connect early-secondary mathematics content (Grades 7-9) in the Common Core State Standards for Mathematics (CCSSM) with mathematics content studied in content courses for certification in secondary teacher preparation programs. Respondents were asked to…

  11. Energetic Landscape of MDM2-p53 Interactions by Computational Mutagenesis of the MDM2-p53 Interaction

    PubMed Central

    Thayer, Kelly M.; Beyer, George A.

    2016-01-01

    The ubiquitin ligase MDM2, a principle regulator of the tumor suppressor p53, plays an integral role in regulating cellular levels of p53 and thus a prominent role in current cancer research. Computational analysis used MUMBO to rotamerize the MDM2-p53 crystal structure 1YCR to obtain an exhaustive search of point mutations, resulting in the calculation of the ΔΔG comprehensive energy landscape for the p53-bound regulator. The results herein have revealed a set of residues R65-E69 on MDM2 proximal to the p53 hydrophobic binding pocket that exhibited an energetic profile deviating significantly from similar residues elsewhere in the protein. In light of the continued search for novel competitive inhibitors for MDM2, we discuss possible implications of our findings on the drug discovery field. PMID:26992014

  12. Energetic Landscape of MDM2-p53 Interactions by Computational Mutagenesis of the MDM2-p53 Interaction.

    PubMed

    Thayer, Kelly M; Beyer, George A

    2016-01-01

    The ubiquitin ligase MDM2, a principle regulator of the tumor suppressor p53, plays an integral role in regulating cellular levels of p53 and thus a prominent role in current cancer research. Computational analysis used MUMBO to rotamerize the MDM2-p53 crystal structure 1YCR to obtain an exhaustive search of point mutations, resulting in the calculation of the ΔΔG comprehensive energy landscape for the p53-bound regulator. The results herein have revealed a set of residues R65-E69 on MDM2 proximal to the p53 hydrophobic binding pocket that exhibited an energetic profile deviating significantly from similar residues elsewhere in the protein. In light of the continued search for novel competitive inhibitors for MDM2, we discuss possible implications of our findings on the drug discovery field. PMID:26992014

  13. Comparison of two fluid warming devices for maintaining body core temperature during living donor liver transplantation: Level 1 H-1000 vs. Fluid Management System 2000

    PubMed Central

    Han, Sangbin; Choi, Junghee; Ko, Justin Sangwook; Gwak, Misook; Lee, Suk-Koo

    2014-01-01

    Background Rapid fluid warming has been a cardinal measure to maintain normothermia during fluid resuscitation of hypovolemic patients. A previous laboratory simulation study with different fluid infusion rates showed that a fluid warmer using magnetic induction is superior to a warmer using countercurrent heat exchange. We tested whether the simulation-based result is translated into the clinical liver transplantation. Methods Two hundred twenty recipients who underwent living donor liver transplantation between April 2009 and October 2011 were initially screened. Seventeen recipients given a magnetic induction warmer (FMS2000) were matched 1 : 1 with those given a countercurrent heat exchange warmer (Level-1 H-1000) based on propensity score. Matched variables included age, gender, body mass index, model for end-stage liver disease score, graft size and time under anesthesia. Core temperatures were taken at predetermined time points. Results Level-1 and FMS groups had comparable core temperature throughout the surgery from skin incision, the beginning/end of the anhepatic phase to skin closure. (P = 0.165, repeated measures ANOVA). The degree of core temperature changes within the dissection, anhepatic and postreperfusion phase were also comparable between the two groups. The minimum intraoperative core temperature was also comparable (Level 1, 35.6℃ vs. FMS, 35.4℃, P = 0.122). Conclusions A countercurrent heat exchange warmer and magnetic induction warmer displayed comparable function regarding the maintenance of core temperature and prevention of hypothermia during living donor liver transplantation. The applicability of the two devices in liver transplantation needs to be evaluated in various populations and clinical settings. PMID:25368785

  14. Supporting Collaboration and Creativity Through Mobile P2P Computing

    NASA Astrophysics Data System (ADS)

    Wierzbicki, Adam; Datta, Anwitaman; Żaczek, Łukasz; Rzadca, Krzysztof

    Among many potential applications of mobile P2P systems, collaboration applications are among the most prominent. Examples of applications such as Groove (although not intended for mobile networks), collaboration tools for disaster recovery (the WORKPAD project), and Skype's collaboration extensions, all demonstrate the potential of P2P collaborative applications. Yet, the development of such applications for mobile P2P systems is still difficult because of the lack of middleware.

  15. O 1s core-level shifts at the anatase TiO2(101)/N3 photovoltaic interface: Signature of H-bonded supramolecular assembly

    NASA Astrophysics Data System (ADS)

    Patrick, Christopher E.; Giustino, Feliciano

    2011-08-01

    We here report an atomic-scale first-principles investigation of the O 1s core-level shifts at the interface between TiO2 and the dye N3 found in dye-sensitized solar cells. We first perform extensive validation of our computational setup in the case of small molecules containing carboxylic acid groups in the gas phase. Then we calculate the O 1s core-level shifts for a variety of atomistic models of the TiO2/N3 interface. We investigate in detail the effects of water contamination, dye packing density, exchange and correlation functionals, and hydrogen-bonding interactions on the calculated core-level spectra. The quantitative comparison between our calculated core-level shifts and measured photoemission spectra [Johansson , J. Phys. Chem. BJPCBFK1520-610610.1021/jp0525282 109, 22256 (2005)] leads us to propose a new atomic-scale model of the TiO2/N3 interface, where the dyes are arranged in supramolecular H-bonded assemblies. Our interface models describe dry TiO2/N3 films as in [Johansson , J. Phys. Chem. BJPCBFK1520-610610.1021/jp0525282 109, 22256 (2005)], and are of direct relevance to solid-state dye-sensitized solar cells. Our present work suggests that the adsorption energetics is not a reliable indicator of the quality of an interface model, and highlights the importance of combining experimental and computational spectroscopy for determining the atomic-scale structure of nanostructured solar cell interfaces.

  16. The importance of L1 ORF2p cryptic sequence to ORF2p fragment-mediated cytotoxicity.

    PubMed

    Christian, Claiborne M; Kines, Kristine J; Belancio, Victoria P

    2016-01-01

    The Long Interspersed Element 1 (LINE1 or L1) ORF2 protein (ORF2p) can cause DNA damage through the activity of its endonuclease domain (EN). The DNA double-strand breaks (DSB) introduced by the ORF2p EN have the potential to be mutagenic. Previously, our lab has shown that ORF2p fragments containing the EN domain could be expressed in mammalian cells and have variable cytotoxicity. Inclusion of the ORF2p sequence C-terminal to the EN domain in these fragments both reduced the cytotoxicity of these fragments and increased their presence in the nucleus as detected by Western blot analysis. Here, we identify the amino acids (aa 270-274) in the newly-identified ORF2p Cryptic region (Cry) that may be important to the subcellular localization and cytotoxic potential of these EN-containing ORF2p fragments. PMID:27583184

  17. Observation of core-level binding energy shifts between (100) surface and bulk atoms of epitaxial CuInSe{sub 2}

    SciTech Connect

    Nelson, A.J.; Berry, G.; Rockett, A.

    1997-04-01

    Core-level and valence band photoemission from semiconductors has been shown to exhibit binding energy differences between surface atoms and bulk atoms, thus allowing one to unambiguously distinguish between the two atomic positions. Quite clearly, surface atoms experience a potential different from the bulk due to the lower coordination number - a characteristic feature of any surface is the incomplete atomic coordination. Theoretical accounts of this phenomena are well documented in the literature for III-V and II-VI semiconductors. However, surface state energies corresponding to the equilibrium geometry of (100) and (111) surfaces of Cu-based ternary chalcopyrite semiconductors have not been calculated or experimental determined. These compounds are generating great interest for optoelectronic and photovoltaic applications, and are an isoelectronic analog of the II-VI binary compound semiconductors. Surface core-level binding energy shifts depend on the surface cohesive energies, and surface cohesive energies are related to surface structure. For ternary compound semiconductor surfaces, such as CuInSe{sub 2}, one has the possibility of variations in surface stoichiometry. Applying standard thermodynamical calculations which consider the number of individual surface atoms and their respective chemical potentials should allow one to qualitatively determine the magnitude of surface core-level shifts and, consequently, surface state energies.

  18. Isotope shifts of the 2 p3 /2-2 p1 /2 transition in B-like ions

    NASA Astrophysics Data System (ADS)

    Zubova, N. A.; Malyshev, A. V.; Tupitsyn, I. I.; Shabaev, V. M.; Kozhedub, Y. S.; Plunien, G.; Brandau, C.; Stöhlker, Th.

    2016-05-01

    Isotope shifts of the 2 p3 /2-2 p1 /2 transition in B-like ions are evaluated for a wide range of the nuclear charge number: Z =8 -92 . The calculations of the relativistic nuclear recoil and nuclear size effects are performed using a large-scale configuration-interaction Dirac-Fock-Sturm method. The corresponding QED corrections are also taken into account. The results of the calculations are compared with the theoretical values obtained with other methods. The accuracy of the isotope shifts of the 2 p3 /2-2 p1 /2 transition in B-like ions is significantly improved.

  19. Functional Diversification of Fungal Glutathione Transferases from the Ure2p Class

    PubMed Central

    Thuillier, Anne; Ngadin, Andrew A.; Thion, Cécile; Billard, Patrick; Jacquot, Jean-Pierre; Gelhaye, Eric; Morel, Mélanie

    2011-01-01

    The glutathione-S-transferase (GST) proteins represent an extended family involved in detoxification processes. They are divided into various classes with high diversity in various organisms. The Ure2p class is especially expanded in saprophytic fungi compared to other fungi. This class is subdivided into two subclasses named Ure2pA and Ure2pB, which have rapidly diversified among fungal phyla. We have focused our analysis on Basidiomycetes and used Phanerochaete chrysosporium as a model to correlate the sequence diversity with the functional diversity of these glutathione transferases. The results show that among the nine isoforms found in P. chrysosporium, two belonging to Ure2pA subclass are exclusively expressed at the transcriptional level in presence of polycyclic aromatic compounds. Moreover, we have highlighted differential catalytic activities and substrate specificities between Ure2pA and Ure2pB isoforms. This diversity of sequence and function suggests that fungal Ure2p sequences have evolved rapidly in response to environmental constraints. PMID:22164343

  20. Circadian regulation of chloroplast transcription in Chlamydomonas is accompanied by little or no fluctuation in RPOD levels or core RNAP activity.

    PubMed

    Kawazoe, Ryo; Mahan, Kristina M; Venghaus, Brad E; Carter, Matthew L; Herrin, David L

    2012-12-01

    In Chlamydomonas growing under 24 h light-dark cycles, chloroplast transcription is under circadian clock control, and peaks early in the morning. The peak (but not trough) requires ongoing cytoplasmic translation, as it is sensitive to cycloheximide (CH). The chloroplast transcriptional apparatus in Chlamydomonas is simpler than in land plants, with only one type of RNA polymerase (RNAP, bacterial) and apparently only one sigma factor (RPOD). Core RNAP can be assayed in vitro with a non-sigma factor dependent template, and is sensitive to rifampicin. We developed a membrane-based assay for RNAP activity, and used it to determine that core activity is only weakly affected by pre-treating cells with CH. Moreover, core chloroplast RNAP activity was steady during a 24 h light-dark cycle. Levels of the sigma factor (RPOD) were examined using western blots, and found to fluctuate less than 25 % during light-dark cycles. These data indicate that circadian regulation of chloroplast transcription is distinct from regulation by sulfur availability, which involves significant changes in RPOD levels. The implications of this data for hypotheses that purport to explain the circadian control mechanism are discussed.

  1. Drug release from film-coated chlorpheniramine maleate nonpareil beads: effect of water-soluble polymer, coating level, and soluble core material.

    PubMed

    Tang, L; Schwartz, J B; Porter, S C; Schnaare, R L; Wigent, R J

    2000-01-01

    The purpose of this research was to use a new drug release model to study the effects of formulation parameters on drug release from a film-coated chlorpheniramine (CPM) nonpareil system. The film-coated CPM nonpareils were prepared by using a fluid bed apparatus. A hydroxylpropylmethylcellulose (HPMC) solution was blended with an aqueous ethylcellulose dispersion (Surelease) to adjust the permeability of the film. The apparent permeability of samples was obtained from dissolution data using a previously reported drug release equation. The apparent permeability was plotted versus the film coating level or the HPMC concentration in the film. When the natural logarithm of the apparent permeability versus coating level was graphed, a biphasic plot was observed in the group without HPMC in the film, showing the occurrence of a critical coating level. It was suggested that a mechanically formed porous film (due to an incomplete coating) could change to a nonporous film after the bead was completely coated. However, in the group that contained 12% HPMC in the film, the critical coating level was not observed. A porous film, formed by the leaching out of the water-soluble polymer, would not change to a nonporous film even after the bead is completely coated. Through a mathematical derivation, the decrease of apparent permeability versus coating level was related to the reduction of the total hole area. The apparent permeability was found to increase with the HPMC concentration. After a critical concentration was reached, the further addition of HPMC into the film caused a rapid increase in apparent permeability. The critical HPMC concentration was related to a minimum domain formation concentration (MDFC). A rapid increase of the drug release was observed when the dissolution profile of a sample made from a regular sugar nonpareil core (soluble) was compared with the sample made from a precoated nonpareil core (insoluble), which suggests that the drug release can be

  2. Phospholipid flippases Lem3p-Dnf1p and Lem3p-Dnf2p are involved in the sorting of the tryptophan permease Tat2p in yeast.

    PubMed

    Hachiro, Takeru; Yamamoto, Takaharu; Nakano, Kenji; Tanaka, Kazuma

    2013-02-01

    The type 4 P-type ATPases are flippases that generate phospholipid asymmetry in membranes. In budding yeast, heteromeric flippases, including Lem3p-Dnf1p and Lem3p-Dnf2p, translocate phospholipids to the cytoplasmic leaflet of membranes. Here, we report that Lem3p-Dnf1/2p are involved in transport of the tryptophan permease Tat2p to the plasma membrane. The lem3Δ mutant exhibited a tryptophan requirement due to the mislocalization of Tat2p to intracellular membranes. Tat2p was relocalized to the plasma membrane when trans-Golgi network (TGN)-to-endosome transport was inhibited. Inhibition of ubiquitination by mutations in ubiquitination machinery also rerouted Tat2p to the plasma membrane. Lem3p-Dnf1/2p are localized to endosomal/TGN membranes in addition to the plasma membrane. Endocytosis mutants, in which Lem3p-Dnf1/2p are sequestered to the plasma membrane, also exhibited the ubiquitination-dependent missorting of Tat2p. These results suggest that Tat2p is ubiquitinated at the TGN and missorted to the vacuolar pathway in the lem3Δ mutant. The NH(2)-terminal cytoplasmic region of Tat2p containing ubiquitination acceptor lysines interacted with liposomes containing acidic phospholipids, including phosphatidylserine. This interaction was abrogated by alanine substitution mutations in the basic amino acids downstream of the ubiquitination sites. Interestingly, a mutant Tat2p containing these substitutions was missorted in a ubiquitination-dependent manner. We propose the following model based on these results; Tat2p is not ubiquitinated when the NH(2)-terminal region is bound to membrane phospholipids, but if it dissociates from the membrane due to a low level of phosphatidylserine caused by perturbation of phospholipid asymmetry in the lem3Δ mutant, Tat2p is ubiquitinated and then transported from the TGN to the vacuole.

  3. Photoionization studies of the 2p resonances of atomic calcium

    NASA Astrophysics Data System (ADS)

    Obst, B.; Hansen, J. E.; Sonntag, B.; Wernet, Ph.; Zimmermann, P.

    2002-06-01

    The Ca 2p resonances at 345-355 eV were studied by photoion and photoelectron spectroscopy using monochromatized synchrotron radiation and atomic-beam technique. The analysis of the excitation and decay of these resonances shows strong configuration mixing between the different subshells of the valence electrons 4s, 3d, and 4p. In the case of the 2p-13/2 resonance structure at 348 eV there are two excited states with nearly equal contributions from the configuration 2p53d4s2 and 2p53d24s, which gives rise to strong variations of the resonantly enhanced 3p4(3d,4s)3 photoelectron lines when scanning the photon energy across the resonance.

  4. Trisomy 2p: Analysis of unusual phenotypic findings

    SciTech Connect

    Lurie, I.W.; Ilyina, H.G.; Gurevich, D.B.

    1995-01-16

    We present three probands with partial trisomies 2p21-23 due to ins(4;2)(q21;p21p23) pat, 2p23-pter due to t(2;4)(p23;q35)mat, and 2p21-pter due to t(2;11)(p21;q23.3)mat. More than 50 cases of partial trisomy 2p have been reviewed and some abnormalities, unusual for most other types of structural autosomal imbalance, have been found in patients with inherited forms of 2p trisomy and in their non-karyotyped sibs. Neural tube defects (anencephaly, occipital encephalocele, and spina bifida) were found in five probands and 4/6 affected non-karyotyped sibs. The only triplicated segment common to all was 2p24. Different forms of {open_quotes}broncho-pulmonary a/hypoplasia{close_quotes} (including two cases of lung agenesis) were described in four patients (overlapping triplicated segment was 2p21-p25). Three patients (with overlapping triplicated segment 2p23-p25) had diaphragmatic hernia. Abnormal rotation of the heart or L-transposition of large vessels (with or without visceral heterotaxia) was found in two infants (overlapping triplicated segment 2p23-p24). In two patients with common triplicated segment 2p22.3-p25, neuroblastoma has been described. The occurrence of all these defects may be explained either by the action of the same gene(s) mapped to 2p24 or by action of some independent factors located in different segments of the short arm. Although the latter hypothesis is much less probable, it can not be rejected at the present time. We propose the existence of a genetic system controlling surveillance of an abnormal embryo to explain the phenotypic differences between patients with the same imbalance within a family. In some {open_quotes}restrictive{close_quotes} combinations the abnormal embryos will die, although in {open_quotes}permissive{close_quotes} combinations they can survive. 47 refs., 2 figs., 3 tabs.

  5. Network Awareness in P2P-TV Applications

    NASA Astrophysics Data System (ADS)

    Traverso, Stefano; Leonardi, Emilio; Mellia, Marco; Meo, Michela

    The increasing popularity of applications for video-streaming based on P2P paradigm (P2P-TV) is raising the interest of both broadcasters and network operators. The former see a promising technology to reduce the cost of streaming content over the Internet, while offering a world-wide service. The latter instead fear that the traffic offered by these applications can grow without control, affecting other services, and possibly causing network congestion and collapse. The “Network-Aware P2P-TV Application over Wise Networks” FP7 project aims at studying and developing a novel P2P-TV application offering the chance to broadcast high definition video to broadcasters and to carefully manage the traffic offered by peers to the network, therefore avoiding worries to Internet providers about network overload. In such context, we design a simulator to evaluate performance of different P2P-TV solutions, to compare them both considering end-users’ and network providers’ perspectives, such as quality of service perceived by subscribers and link utilization. In this paper, we provide some results that show how effective can be a network aware P2P-TV system.

  6. Genetic heterogeneity of gingival fibromatosis on chromosome 2p

    PubMed Central

    Shashi, V.; Pallos, D.; Pettenati, M.; Cortelli, J.; Fryns, J.; von Kap-Herr, C.; Hart, T.

    1999-01-01

    Gingival fibromatosis (GF) occurs in several genetic forms as a simple Mendelian trait, in malformation syndromes, and in some chromosomal disorders. Specific genes responsible for GF have not been identified. An autosomal dominant form of hereditary gingival fibromatosis (HGF, MIM 135300) was recently mapped to chromosome 2p21 in a large Brazilian family and there was an earlier report of GF in a boy with a cytogenetic duplication involving 2p13→p21. We thus hypothesised that a common gene locus may be responsible for GF in both the Brazilian family and the boy with the chromosome 2p duplication. We performed additional genetic linkage studies on the Brazilian family and molecular cytogenetic studies on the patient with the cytogenetic duplication to correlate more precisely the genetic interval of the HGF phenotype with the duplicated 2p interval. Additional linkage analysis of new family members resulted in refinement of the candidate region for HGF to an 8 Mb region. Molecular cytogenetic analysis of the 2p13→p21 duplication associated with GF showed that the duplicated region was proximal to the candidate interval for HGF. Thus, our results support the presence of two different gene loci on chromosome 2p that are involved in GF.


Keywords: gingival fibromatosis; chromosome duplication; chromosome 2 PMID:10507724

  7. Density Functional Theory Study of the Energetics, Electronic Structure, and Core-Level Shifts of NO Adsorption on the Pt(111) Surface

    SciTech Connect

    Zeng, Z. H.; Da Silva, J. L. F.; Deng, H. Q.; Li, W. X.

    2009-01-01

    In this work, we report a first-principles investigation of the energetics, structures, electronic properties, and core-level shifts of NO adsorption on the Pt(111) surface. Our calculations are based on density functional theory within the framework of the ultrasoft pseudopotential plane-wave and the all-electron projected augmented-wave methods. We found that at 0.25, 0.50, and 0.75 monolayer, NO adsorbs preferentially in the fcc, fcc+top, and fcc+top+hcp sites, respectively. The geometric parameters, adsorption energies, vibrational frequencies, and work-function changes are in good agreement with the experimental data. The interaction between NO and Pt(111) was found to follow a donation-back-donation process, in which the NO {sigma} states donate electrons to the substrate Pt d states, while the substrate Pt d states back donate to the NO {pi} states. Though there is an overall net charge transfer from the substrate to the NO adsorbate regardless of the adsorption sites and coverages, the spatial redistribution of the transferred electron is site dependent. The charge accumulation for NO in the top sites occurs closer to the surface than NO in the hollow sites, which results in the reduction of the Pt(111) surface work function for the top NO but an increase for the hollow NO. The core-level shifts of the topmost surface Pt atoms coordinated with top and hollow NO molecules at different coverages are in excellent agreement with experiments. In contrast, the N 1s core-level shifts between top and hollow NO ({approx}0.7 eV) deviated significantly from the zero shift found in experiments. Our analysis indicates that the difference may come from the thermal vibration and rotation of adsorbed NO on the Pt(111) surface.

  8. A study of a sector spectrophotometer and auroral O+(2P-2D) emissions

    NASA Technical Reports Server (NTRS)

    Swenson, G. R.

    1976-01-01

    The metastable O+(2P-2D) auroral emission was investigated. The neighboring OH contaminants and low intensity levels of the emission itself necessitated the evolution of an instrument capable of separating the emission from the contaminants and having a high sensitivity in the wavelength region of interest. A new type of scanning photometer was developed and its properties are discussed. The theoretical aspects of auroral electron interaction with atomic oxygen and the resultant O+(2P-2D) emissions were examined in conjunction with N2(+)1NEG emissions. Ground based measurements of O+(2P-2D) auroral emission intensities were made using the spatial scanning photometer (sector spectrophotometer). Simultaneous measurements of N2(+)1NEG sub 1,0 emission intensity were made in the same field of view using a tilting photometer. Time histories of the ratio of these two emissions made in the magnetic zenith during auroral breakup periods are given. Theories of I sub 7319/I sub 4278 of previous investigators were presented. A rocket measurement of N2(+)1NEG sub 0,0 and O+(2P-2D) emission in aurora was examined in detail and was found to agree with the ground based measurements. Theoretical examination resulted in the deduction of the electron impact efficiency generating O+(2P) and also suggests a large source of O+(2P) at low altitude. A possible source is charge exchange of N+(1S) with OI(3P).

  9. Levels and ages of selenium and metals in sedimentary cores of Ise Bay as determined by 210-Pb dating technique

    SciTech Connect

    Itoh, K.; Chikuma, M.; Tanaka, H.

    1987-08-01

    Ise Bay is connected with estuaries of Nagoya harbor which is one of the most active industrial areas in Japan. Nagoya harbor estuaries are recipient of a large quantity of municipal and industrial discharge. The land boundaries of estuaries are sites of the manufacturing industries and they are utilized by oil tankers and cargo vessels. Accumulation of various kinds of metal such as selenium, mercury, zinc, copper, lead, and chromium have occurred in sediments for many years. The authors have carried out an extensive investigation on the selenium pollution of sea water and sediments of Nagoya harbor estuaries. The input of selenium to Ise Bay has occurred ever since the industrial activity was established in Nagoya city. Investigators have reported the sedimentary record of metals of Tokyo Bay, Osaka Bay and Seto Inland Sea. Some investigators reported the pollution caused by polynuclear aromatic hydrocarbon in sediments of Ise Bay, but did not mention metals. The authors determined metals including selenium in sedimentary core samples. The ages of those samples were already estimated by 210-Pb dating technique.

  10. Dim2p, a KH-domain protein required for small ribosomal subunit synthesis

    PubMed Central

    VANROBAYS, EMMANUEL; GÉLUGNE, JEAN-PAUL; CAIZERGUES-FERRER, MICHÈLE; LAFONTAINE, DENIS L.J.

    2004-01-01

    Recent proteomic analyses are revealing the dynamics of preribosome assembly. Following cleavage at processing site A2, which generates the 20S pre-rRNA (the immediate precursor to the 18S rRNA), early RRPs (ribosomal RNA processing factors) are released in bulk from the preribosomes, and the resulting pre-40S subunits are left associated with a limited set of proteins that we refer to as the SSU RRP complex. Dim2p, a core constituent of the SSU RRP complex and conserved KH-domain containing protein, is required for pre-rRNA processing and is associated with early nucleolar and late cytoplasmic pre-rRNA species. Consistently, Dim2p shuttles between the nucle(ol)us and the cytoplasm, a trafficking that is tightly regulated by growth. The association of Dim2p with the 18S rRNA dimethyltransferase Dim1p, as well as its requirement for pre-rRNA processing at cleavage sites A1 and A2 and for 18S rRNA dimethylation, suggest that Dim2p may recruit Dim1p to nucleolar pre-rRNAs through its KH domain. PMID:15037774

  11. 1S core-level spectroscopy of graphite: The effects of phonons on emission and absorption and validity of the final-state rule

    NASA Astrophysics Data System (ADS)

    Franck, C. P.; Schnatterly, S. E.; Zutavern, F. J.; Aton, T.; Cafolla, T.; Carson, R. D.

    1985-04-01

    We have used both electron-induced soft x-ray emission and fast inelastic electron scattering to observe 1S core-level emission and absorption in graphite near threshold. Linear phonon coupling with partial relaxation is found to quantitatively explain the absorption linewidth, the emission broadening, and the unusually large difference between emission and absorption threshold energies (Stokes shift). Both emission and absorption line shapes quantitatively obey the final-state rule, which asserts that the best single-particle potential describing these many electron processes is the final-state potential.

  12. A suggested emergency medicine boot camp curriculum for medical students based on the mapping of Core Entrustable Professional Activities to Emergency Medicine Level 1 milestones

    PubMed Central

    Lamba, Sangeeta; Wilson, Bryan; Natal, Brenda; Nagurka, Roxanne; Anana, Michael; Sule, Harsh

    2016-01-01

    Background An increasing number of students rank Emergency Medicine (EM) as a top specialty choice, requiring medical schools to provide adequate exposure to EM. The Core Entrustable Professional Activities (EPAs) for Entering Residency by the Association of American Medical Colleges combined with the Milestone Project for EM residency training has attempted to standardize the undergraduate and graduate medical education goals. However, it remains unclear as to how the EPAs correlate to the milestones, and who owns the process of ensuring that an entering EM resident has competency at a certain minimum level. Recent trends establishing specialty-specific boot camps prepare students for residency and address the variability of skills of students coming from different medical schools. Objective Our project’s goal was therefore to perform a needs assessment to inform the design of an EM boot camp curriculum. Toward this goal, we 1) mapped the core EPAs for graduating medical students to the EM residency Level 1 milestones in order to identify the possible gaps/needs and 2) conducted a pilot procedure workshop that was designed to address some of the identified gaps/needs in procedural skills. Methods In order to inform the curriculum of an EM boot camp, we used a systematic approach to 1) identify gaps between the EPAs and EM milestones (Level 1) and 2) determine what essential and supplemental competencies/skills an incoming EM resident should ideally possess. We then piloted a 1-day, three-station advanced ABCs procedure workshop based on the identified needs. A pre-workshop test and survey assessed knowledge, preparedness, confidence, and perceived competence. A post-workshop survey evaluated the program, and a posttest combined with psychomotor skills test using three simulation cases assessed students’ skills. Results Students (n=9) reported increased confidence in the following procedures: intubation (1.5–2.1), thoracostomy (1.1–1.9), and central venous

  13. Synthetic, Spectroscopic, and Electrochemical Studies of the Isomerically-Rich [M(CO)(2)(P(2)P')X](+/0) (M = Mn, Re; X = Cl, Br; P(2)P' = eta(3)-Ph(2)P(CH(2))(2)P(Ph)(CH(2))(2)PPh(2)) System: Structural Characterization of a Novel Pair of Diastereoisomers of cis,mer-Re(CO)(2)(P(2)P')Cl.

    PubMed

    Bond, Alan M.; Colton, Ray; Gable, Robert W.; Mackay, Maureen F.; Walter, Jacky N.

    1997-03-12

    Reaction of Mn(CO)(5)X (X = Cl, Br) with Ph(2)P(CH(2))(2)P(Ph)(CH(2))(2)PPh(2) (P(2)P') in refluxing xylene led to the formation of isomerically pure cis,mer-Mn(CO)(2)(eta(3)-P(2)P')X. Cyclic voltammograms in dichloromethane (0.1 M Bu(4)NPF(6)) show a reversible one-electron oxidation (process 1, E(1/2) = 0.142 V) to give cis,mer-[Mn(CO)(2)(P(2)P')X](+). However, in acetone (0.1 M Bu(4)NPF(6)) at room temperature, process 1 is not reversible and an additional redox process 4 (E(1/2) = 0.048 V) is observed. Process 4 is not observed at low temperatures, and at higher temperatures in acetone it merges with process 1 and also a new reversible redox couple (process 5, E(1/2) = -0.411 V) appears. A combination of electrolyses, chemical oxidation, and subsequent reduction, coupled with IR and (31)P NMR spectroscopies and electrospray mass spectrometry (ESMS), is used to show that processes 1, 4, and 5 are all associated with redox and interconversion reactions of different isomers of Mn(CO)(2)(P(2)P')X and [Mn(CO)(2)(P(2)P')X](+). Other irreversible processes due to oxidation of the different isomers of [Mn(CO)(2)(P(2)P')X](+) are observed at very positive potentials. Reaction between Re(CO)(5)X and P(2)P' in refluxing mesitylene gives a soluble product and a small amount of precipitate. The major soluble product was identified as cis,mer-Re(CO)(2)(P(2)P')X, and the oxidative chemistry is similar to that of the manganese analogues. The precipitate consists of five compounds, one of which was cis,mer-Re(CO)(2)(P(2)P')X. The new compounds A-D were identified as follows: A is cis,mer-{Re(CO)(2)(P(2)P')X}(2), a dimeric species with bridging P(2)P' ligands. The spectroscopic data for B indicated that it was a form of cis,mer-Re(CO)(2)(P(2)P')X, but not the same as the major product. Compound C is cis,fac-Re(CO)(2)(P(2)P')X, and compound D was shown to be fac-[Re(CO)(3)(P(2)P')]X. The crystal structures of cis,mer-Re(CO)(2)(P(2)P')Cl(I) and cis,mer-Re(CO)(2)(P(2)P')Cl(II) show

  14. Kinetic Energy Distribution of H(2p) Atoms from Dissociative Excitation of H2

    NASA Technical Reports Server (NTRS)

    Ajello, Joseph M.; Ahmed, Syed M.; Kanik, Isik; Multari, Rosalie

    1995-01-01

    The kinetic energy distribution of H(2p) atoms resulting from electron impact dissociation of H2 has been measured for the first time with uv spectroscopy. A high resolution uv spectrometer was used for the measurement of the H Lyman-alpha emission line profiles at 20 and 100 eV electron impact energies. Analysis of the deconvolved 100 eV line profile reveals the existence of a narrow line peak and a broad pedestal base. Slow H(2p) atoms with peak energy near 80 meV produce the peak profile, which is nearly independent of impact energy. The wings of H Lyman-alpha arise from dissociative excitation of a series of doubly excited Q(sub 1) and Q(sub 2) states, which define the core orbitals. The fast atom energy distribution peaks at 4 eV.

  15. Monitoring autophagic flux using Ref(2)P, the Drosophila p62 ortholog.

    PubMed

    DeVorkin, Lindsay; Gorski, Sharon M

    2014-09-02

    Human p62, also known as Sequestome-1 (SQSTM1), is a multifunctional scaffold protein that contains many domains, including a Phox/Bem1P (PB1) multimerization domain, an ubiquitin-associated (UBA) domain, and a light chain 3 (LC3) recognition sequence. p62 binds ubiquitinated proteins and targets them for degradation by the proteasome. In addition, p62 directly binds LC3; this may serve as a mechanism to deliver ubiquitinated proteins for degradation by autophagy. During this process, p62 itself is degraded. The inhibition of autophagy leads to the accumulation of p62, indicating that it can be used as a marker of autophagic flux. Ref(2)P (refractory to sigma P), the Drosophila ortholog of p62, is also required for the formation of ubiquitinated protein aggregates. Ref(2)P contains a putative LC3-interacting region, and genetic inhibition of autophagy in Drosophila leads to the accumulation of Ref(2)P protein levels. Thus, like p62, Ref(2)P may serve as a marker of autophagic flux. Here we provide two procedures to examine Ref(2)P protein levels in Drosophila ovaries.

  16. An efficient query mechanism base on P2P networks

    NASA Astrophysics Data System (ADS)

    Wang, Xiaohua; Mu, Aiqin; Zhao, Defang

    2013-07-01

    How to implement the efficient query is the key problem deployed on P2P networks. This paper analyses the shortage of several query algorithm, and presents a new algorithm DDI, which means distributed searching with double indices. It discusses the popularity of documents and the linking status of the networks, and calculates the availability of the nodes in whole network, determines the route of the query process. It compares the items of time using, the quantity of requests and update information by the emulate experiments. Along with the rapid development of computer network technology, peer-to-peer (referred to as P2P) network research has gradually become mature, and it is widely used in different fields, some large P2P computing project has entered the implementation stage. At present, many more popular software systems such as Gnutella, Freenet, Napster are deployed based on P2P technology. How to achieve effective information query has become one of the key problems of P2P research.

  17. Protecting Data Privacy in Structured P2P Networks

    NASA Astrophysics Data System (ADS)

    Jawad, Mohamed; Serrano-Alvarado, Patricia; Valduriez, Patrick

    P2P systems are increasingly used for efficient, scalable data sharing. Popular applications focus on massive file sharing. However, advanced applications such as online communities (e.g., medical or research communities) need to share private or sensitive data. Currently, in P2P systems, untrusted peers can easily violate data privacy by using data for malicious purposes (e.g., fraudulence, profiling). To prevent such behavior, the well accepted Hippocratic database principle states that data owners should specify the purpose for which their data will be collected. In this paper, we apply such principles as well as reputation techniques to support purpose and trust in structured P2P systems. Hippocratic databases enforce purpose-based privacy while reputation techniques guarantee trust. We propose a P2P data privacy model which combines the Hippocratic principles and the trust notions. We also present the algorithms of PriServ, a DHT-based P2P privacy service which supports this model and prevents data privacy violation. We show, in a performance evaluation, that PriServ introduces a small overhead.

  18. [Vertical distribution and relationship between 210Pb(ex) activities and nutrients in sediment cores of two different eutrophication level lakes].

    PubMed

    Wang, Xiao-Lei; Yang, Hao; Gu, Zhu-Jun; Zhang, Ming-Li

    2014-07-01

    The 210Pb(ex) activities and nutrient (TOC, TN and TP) contents in sediment cores of Fuxian Lake and Dianchi Lake were measured by traditional methods, as well as their vertical distribution and relationship were also comparatively analyzed in this paper. The study results indicated that the vertical distributions of 210Pb(ex) and nutrients were significantly different between Fuxian Lake and Dianchi Lake. The variation amplitude of 210Pb(ex) activities in Dianchi Lake was higher than that in Fuxian Lake. The disordered distribution characteristics of 210Pb(ex) in Dianchi Lake surface sediments were closely related to physicochemical migration of lead caused by human activities. The variation trends of nutrients in sediment cores were corresponded to local natural evolution and human activities in different historical periods. Relationship between 210Pb(ex) activities and nutrients were mainly affected by the nutrition level of lakes. The greater the lake eutrophication level was, the stronger the correlation was found. To the individual nutrient indicators, similar characteristics were shown in the two lakes, and the order was TOC > TP > TN.

  19. Angle-resolved photoemission extended fine structure of the Ni 3p, Cu 3s, and Cu 3p core levels of the respective clean (111) surfaces

    SciTech Connect

    Huff, W.R. |; Chen, Y.; Kellar, S.A.; Moler, E.J. |; Hussain, Z.; Huang, Z.Q.; Zheng, Y.; Shirley, D.A.

    1997-07-01

    We report a non-s initial-state angle-resolved photoemission extended fine-structure (ARPEFS) study of clean surfaces for the purpose of further understanding the technique. The surface structure sensitivity of ARPEFS applied to clean surfaces and to arbitrary initial states is studied using normal photoemission data taken from the Ni 3p core levels of a Ni(111) single crystal and the Cu 3s and the Cu 3p core levels of a Cu(111) single crystal. The Fourier transforms of these clean surface data are dominated by backscattering. Unlike the s initial-state data, the p initial-state data show a peak in the Fourier transform corresponding to in-plane scattering from the six nearest neighbors to the emitter. Evidence was seen for single-scattering events from the same plane as the emitters and double-scattering events. Using a recently developed, multiple-scattering calculation program, ARPEFS data from clean surfaces and from p initial states can be modeled to high precision. Although there are many layers of emitters when measuring photoemission from a clean surface, test calculations show that the ARPEFS signal is dominated by photoemission from atoms in the first two crystal layers. Thus ARPEFS applied to clean surfaces is sensitive to surface reconstruction. The best-fit calculation for clean Ni(111) indicates an expansion of the first two layers. {copyright} {ital 1997} {ital The American Physical Society}

  20. Performance of the TPSS Functional on Predicting Core Level Binding Energies of Main Group Elements Containing Molecules: A Good Choice for Molecules Adsorbed on Metal Surfaces.

    PubMed

    Pueyo Bellafont, Noèlia; Viñes, Francesc; Illas, Francesc

    2016-01-12

    Here we explored the performance of Hartree-Fock (HF), Perdew-Burke-Ernzerhof (PBE), and Tao-Perdew-Staroverov-Scuseria (TPSS) functionals in predicting core level 1s binding energies (BEs) and BE shifts (ΔBEs) for a large set of 68 molecules containing a wide variety of functional groups for main group elements B → F and considering up to 185 core levels. A statistical analysis comparing with X-ray photoelectron spectroscopy (XPS) experiments shows that BEs estimations are very accurate, TPSS exhibiting the best performance. Considering ΔBEs, the three methods yield very similar and excellent results, with mean absolute deviations of ∼0.25 eV. When considering relativistic effects, BEs deviations drop approaching experimental values. So, the largest mean percentage deviation is of 0.25% only. Linear trends among experimental and estimated values have been found, gaining offsets with respect to ideality. By adding relativistic effects to offsets, HF and TPSS methods underestimate experimental values by solely 0.11 and 0.05 eV, respectively, well within XPS chemical precision. TPSS is posed as an excellent choice for the characterization, by XPS, of molecules on metal solid substrates, given its suitability in describing metal substrates bonds and atomic and/or molecular orbitals.

  1. Holocene lake level changes at a lowland lake in northeastern Germany inferred from acoustic sub-bottom profiling and a transect of sediment cores

    NASA Astrophysics Data System (ADS)

    Dietze, Elisabeth; Zawiska, Izabela; Słowiński, Michał; Brauer, Achim

    2015-04-01

    Holocene lake level changes were studied at Lake Fürstenseer See, a typical lake with complex basin morphology in northeastern German sandur area. An acoustic sub-bottom profile and a transect of four long sediment cores in the deepest lake sub-basin were analyzed. The cores were dated with AMS-14C and correlated with multiple proxies (sediment facies, μ-XRF, macrofossils, subfossil Cladocera, carbonate isotopes). At sites in 10 and 15 m water depth, shifts in the sand-mud boundary, i.e. sediment limit sensu Digerfeldt (1986), allowed quantitative estimates of the absolute amplitude of lake level changes. At sites in 20 and 23 m water depth, the negative correlation of Ca and Ti reflect lake level changes qualitatively. During high lake stands massive organic muds were deposited. Lower lake levels isolated the lake sub-basins which reduced the overall water circulation and lead to the deposition of Ti-poor carbonate muds. Furthermore, macrofossil and subfossil Cladocera analyses were used as proxies for the intense reworking at the slope and for the trophic state of the lake, respectively. Lake levels were up to 4 m higher, e.g. around 5000 cal. yrs BP and during the Medieval time period (see also Kaiser et al., 2014). During the early to mid-Holocene (between 9400 and 6400 cal. yrs BP), Lake Fürstenseer See fluctuated at an at least 3-m lower level. Further water level changes can be related to known climatic events and regional human impact. Digerfeldt, G., 1986. Studies on past lake-level fluctuations. In Berglund, B. (ed.), Handbook of Holocene Palaeoecology and Palaeohydrology: 127-144. John Wiley & Sons, New York. Kaiser, K., Küster, M., Fülling, A., Theuerkauf, M., Dietze, E., Graventein, H., Koch, P.J., Bens, O., Brauer, A., 2014. Littoral landforms and pedosedimentary sequences indicating late Holocene lake-level changes in northern central Europe ' A case study from northeastern Germany. Geomorphology 216, 58-78.

  2. Negative photoion spectroscopy of freon molecules in the vicinity of the Cl 2p edge

    SciTech Connect

    Scully, S.W.J.; Mackie, R.A.; Browning, R.; Dunn, K.F.; Latimer, C.J.

    2004-10-01

    Polar photodissociation of CF{sub n}Cl{sub 4-n} (n=0-2) has been studied using synchrotron radiation within the energy range 195-217 eV. The first observations of negative photoion fragments from these molecules after core excitation are reported. In addition to observing a number of previously known resonances two additional resonant states, just above the Cl 2p ionization limit, are observed and play an important role in the polar photodissociation process. The difficulties in identifying these above threshold spin-split features using negative photoion spectroscopy are discussed.

  3. Effect of metallothionein core promoter region polymorphism on cadmium, zinc and copper levels in autopsy kidney tissues from a Turkish population

    SciTech Connect

    Kayaalti, Zeliha; Mergen, Goerkem; Soeylemezoglu, Tuelin

    2010-06-01

    Metallothioneins (MTs) are metal-binding, low molecular weight proteins and are involved in pathophysiological processes like metabolism of essential metals, metal ion homeostasis and detoxification of heavy metals. Metallothionein expression is induced by various heavy metals especially cadmium, mercury and zinc; MTs suppress toxicity of heavy metals by binding themselves to these metals. The aim of this study was to investigate the association between the - 5 A/G metallothionein 2A (MT2A) single nucleotide polymorphism (SNP) and Cd, Zn and Cu levels in the renal cortex from autopsy cases. MT2A core promoter region - 5 A/G SNP was analyzed by PCR-RFLP method using 114 autopsy kidney tissues and the genotype frequencies of this polymorphism were found as 87.7% homozygote typical (AA), 11.4% heterozygote (AG) and 0.9% homozygote atypical (GG). In order to assess the Cd, Zn and Cu levels in the same autopsy kidney tissues, a dual atomic absorption spectrophotometer system was used and the average levels of Cd, Zn and Cu were measured as 95.54 {+-} 65.58 {mu}g/g, 181.20 {+-} 87.72 {mu}g/g and 17.14 {+-} 16.28 {mu}g/g, respectively. As a result, no statistical association was found between the - 5 A/G SNP in the MT2A gene and the Zn and Cu levels in the renal cortex (p > 0.05), but considerably high accumulation of Cd was monitored for individuals having AG (151.24 {+-} 60.21 {mu}g/g) and GG genotypes (153.09 {mu}g/g) compared with individuals having AA genotype (87.72 {+-} 62.98 {mu}g/g) (p < 0.05). These results show that the core promoter region polymorphism of metallothionein 2A increases the accumulation of Cd in human renal cortex.

  4. Fragrance material review on 2-(p-tolyloxy)ethyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2-(p-tolyloxy)ethyl acetate when used as a fragrance ingredient is presented. 2-(p-tolyloxy)ethyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-(p-tolyloxy)ethyl acetate were evaluated, then summarized, and includes physical properties data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  5. Fragrance material review on 2-(p-tolyloxy)ethyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2-(p-tolyloxy)ethyl acetate when used as a fragrance ingredient is presented. 2-(p-tolyloxy)ethyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-(p-tolyloxy)ethyl acetate were evaluated, then summarized, and includes physical properties data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414652

  6. Faraday effect in Sn2P2S6 crystals.

    PubMed

    Krupych, Oleh; Adamenko, Dmytro; Mys, Oksana; Grabar, Aleksandr; Vlokh, Rostyslav

    2008-11-10

    We have revealed a large Faraday rotation in tin thiohypodiphosphate (Sn(2)P(2)S(6)) crystals, which makes this material promising for magneto-optics. The effective Faraday tensor component and the Verdet constant for the direction of the optic axis have been determined by measuring the pure Faraday rotation in Sn(2)P(2)S(6) crystals with both the single-ray and small-angular polarimetric methods at the normal conditions and a wavelength of 632.8 nm. The effective Verdet constant is found to be equal to 115 rad/T x m.

  7. Dissociative recombination of molecular ions in the He-Ne plasma. Partial rate constants of atoms formation in the 2 p 53d and 2 p 54d configurations

    NASA Astrophysics Data System (ADS)

    Ivanov, V. A.; Petrovskaya, A. S.; Skoblo, Yu. E.

    2016-02-01

    A spectroscopic study of population processes was carried out for states of the neon atom of the 2 p 53 d configuration in the discharge afterglow in helium with a small admixture of neon ([Ne]/[He] ≈ 10-5) at a pressure of 38 Torr. Based on the comparative analysis of time dependences of the spectral line intensities of the Ne I 2 p 53 d → 2 p 53 d and 2 p 54 d → 2 p 53 d transitions and ratio of ion densities [Ne 2 + ]/[HeNe+], it has been found that the formation of excited Ne(2 p 53 d) atoms in the afterglow caused by two dissociative recombination processes: HeNe+ + e → Ne(2 p 53 d) + Ne and Ne 2 + + e → Ne(2 p 53 d) + Ne. Distributions of population fluxes of the 2 p 53 d levels Γ _{3{d_t}}^{HeN{e^ + }} and Γ _{3{d_t}}^{Ne_2^ + }—were obtained for each of these processes.

  8. Systems-level response to point mutations in a core metabolic enzyme modulates genotype-phenotype relationship.

    PubMed

    Bershtein, Shimon; Choi, Jeong-Mo; Bhattacharyya, Sanchari; Budnik, Bogdan; Shakhnovich, Eugene

    2015-04-28

    Linking the molecular effects of mutations to fitness is central to understanding evolutionary dynamics. Here, we establish a quantitative relation between the global effect of mutations on the E. coli proteome and bacterial fitness. We created E. coli strains with specific destabilizing mutations in the chromosomal folA gene encoding dihydrofolate reductase (DHFR) and quantified the ensuing changes in the abundances of 2,000+ E. coli proteins in mutant strains using tandem mass tags with subsequent LC-MS/MS. mRNA abundances in the same E. coli strains were also quantified. The proteomic effects of mutations in DHFR are quantitatively linked to phenotype: the SDs of the distributions of logarithms of relative (to WT) protein abundances anticorrelate with bacterial growth rates. Proteomes hierarchically cluster first by media conditions, and within each condition, by the severity of the perturbation to DHFR function. These results highlight the importance of a systems-level layer in the genotype-phenotype relationship.

  9. Low-level detection and quantification of Plutonium(III, IV, V,and VI) using a liquid core waveguide

    SciTech Connect

    Wilson, Richard E.; Hu, Yung-Jin; Nitsche, Heino

    2003-06-28

    Understanding the aqueous chemistry of plutonium, in particular in environmental conditions, is often complicated by plutonium's complex redox chemistry. Because plutonium possesses four oxidation states, all of which can coexist in solution, a reliable method for the identification of these oxidation states is needed. The identification of plutonium oxidation states at low levels in aqueous solution is often accomplished through an indirect determination using series of liquid-liquid extraction procedures using oxidation state specific reagents such as HDEHP and TTA. While these methods, coupled with radioactive counting techniques provide superior limits of detection they may influence the plutonium redox equilibrium, are time consuming, waste intensive and costly. Other analytical methods such as mass spectrometry and radioactive counting as stand alone methods provide excellent detection limits but lack the ability to discriminate between the oxidation states of the plutonium ions in solution.

  10. Rapid measurement of perchlorate in polar ice cores down to sub-ng L(-1) levels without pre-concentration.

    PubMed

    Peterson, Kari; Cole-Dai, Jihong; Brandis, Derek; Cox, Thomas; Splett, Scott

    2015-10-01

    An ion chromatography-electrospray ionization-tandem mass spectrometry (IC-ESI-MS/MS) method has been developed for rapid and accurate measurement of perchlorate in polar snow and ice core samples in which perchlorate concentrations are expected to be as low as 0.1 ng L(-1). Separation of perchlorate from major inorganic species in snow is achieved with an ion chromatography system interfaced to an AB SCIEX triple quadrupole mass spectrometer operating in multiple reaction monitoring mode. Under optimized conditions, the limit of detection and lower limit of quantification without pre-concentration have been determined to be 0.1 and 0.3 ng L(-1), respectively, with a linear dynamic range of 0.3-10.0 ng L(-1) in routine measurement. These represent improvements over previously reported methods using similar analytical techniques. The improved method allows fast, accurate, and reproducible perchlorate quantification down to the sub-ng L(-1) level and will facilitate perchlorate measurement in the study of natural perchlorate production with polar ice cores in which perchlorate concentrations are anticipated to vary in the low and sub-ng L(-1) range. Initial measurements of perchlorate in ice core samples from central Greenland show that typical perchlorate concentrations in snow dated prior to the Industrial Revolution are about 0.8 ng L(-1), while perchlorate concentrations are significantly higher in recent (post-1980) snow, suggesting that anthropogenic sources are a significant contributor to perchlorate in the current environment.

  11. Composite Cores

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Spang & Company's new configuration of converter transformer cores is a composite of gapped and ungapped cores assembled together in concentric relationship. The net effect of the composite design is to combine the protection from saturation offered by the gapped core with the lower magnetizing requirement of the ungapped core. The uncut core functions under normal operating conditions and the cut core takes over during abnormal operation to prevent power surges and their potentially destructive effect on transistors. Principal customers are aerospace and defense manufacturers. Cores also have applicability in commercial products where precise power regulation is required, as in the power supplies for large mainframe computers.

  12. Time-related dynamics of variation in core clock gene expression levels in tissues relevant to the immune system.

    PubMed

    Mazzoccoli, G; Sothern, R B; Greco, A; Pazienza, V; Vinciguerra, M; Liu, S; Cai, Y

    2011-01-01

    Immune parameters show rhythmic changes with a 24-h periodicity driven by an internal circadian timing system that relies on clock genes (CGs). CGs form interlocked transcription-translation feedback loops to generate and maintain 24-h mRNA and protein oscillations. In this study we evaluate and compare the profiles and the dynamics of variation of CG expression in peripheral blood, and two lymphoid tissues of mice. Expression levels of seven recognized key CGs (mBmal1, mClock, mPer1, mPer2, mCry1, mCry2, and Rev-erbalpha) were evaluated by quantitative RT- PCR in spleen, thymus and peripheral blood of C57BL/6 male mice housed on a 12-h light (L)-dark (D) cycle and sacrificed every 4 h for 24 h (3-4 mice/time point). We found a statistically significant time-effect in spleen (S), thymus (T) and blood (B) for the original values of expression level of mBmal1 (S), mClock (T, B), mPer1 (S, B), mPer2 (S), mCry1 (S), mCry2 (B) and mRev-Erbalpha (S, T, B) and for the fractional variation calculated between single time-point expression value of mBmal1 (B), mPer2 (T), mCry2 (B) and mRev-Erbalpha (S). A significant 24-h rhythm was validated for five CGs in blood (mClock, mPer1, mPer2, mCry2, mRev-Erbalpha), for four CGs in the spleen (mBmal1, mPer1, mPer2, mRev-Erbalpha), and for three CGs in the thymus (mClock, mPer2, mRev-Erbalpha). The original values of acrophases for mBmal1, mClock, mPer1, mPer2, mCry1 and mCry2 were very similar for spleen and thymus and advanced by several hours for peripheral blood compared to the lymphoid tissues, whereas the phases of mRev-Erbalpha were coincident for all three tissues. In conclusion, central and peripheral lymphoid tissues in the mouse show different sequences of activation of clock gene expression compared to peripheral blood. These differences may underlie the compartmental pattern of web functioning in the immune system.

  13. Time-related dynamics of variation in core clock gene expression levels in tissues relevant to the immune system.

    PubMed

    Mazzoccoli, G; Sothern, R B; Greco, A; Pazienza, V; Vinciguerra, M; Liu, S; Cai, Y

    2011-01-01

    Immune parameters show rhythmic changes with a 24-h periodicity driven by an internal circadian timing system that relies on clock genes (CGs). CGs form interlocked transcription-translation feedback loops to generate and maintain 24-h mRNA and protein oscillations. In this study we evaluate and compare the profiles and the dynamics of variation of CG expression in peripheral blood, and two lymphoid tissues of mice. Expression levels of seven recognized key CGs (mBmal1, mClock, mPer1, mPer2, mCry1, mCry2, and Rev-erbalpha) were evaluated by quantitative RT- PCR in spleen, thymus and peripheral blood of C57BL/6 male mice housed on a 12-h light (L)-dark (D) cycle and sacrificed every 4 h for 24 h (3-4 mice/time point). We found a statistically significant time-effect in spleen (S), thymus (T) and blood (B) for the original values of expression level of mBmal1 (S), mClock (T, B), mPer1 (S, B), mPer2 (S), mCry1 (S), mCry2 (B) and mRev-Erbalpha (S, T, B) and for the fractional variation calculated between single time-point expression value of mBmal1 (B), mPer2 (T), mCry2 (B) and mRev-Erbalpha (S). A significant 24-h rhythm was validated for five CGs in blood (mClock, mPer1, mPer2, mCry2, mRev-Erbalpha), for four CGs in the spleen (mBmal1, mPer1, mPer2, mRev-Erbalpha), and for three CGs in the thymus (mClock, mPer2, mRev-Erbalpha). The original values of acrophases for mBmal1, mClock, mPer1, mPer2, mCry1 and mCry2 were very similar for spleen and thymus and advanced by several hours for peripheral blood compared to the lymphoid tissues, whereas the phases of mRev-Erbalpha were coincident for all three tissues. In conclusion, central and peripheral lymphoid tissues in the mouse show different sequences of activation of clock gene expression compared to peripheral blood. These differences may underlie the compartmental pattern of web functioning in the immune system. PMID:22230394

  14. Measurement and Analysis of P2P IPTV Program Resource

    PubMed Central

    Chen, Xingshu; Wang, Haizhou; Zhang, Qi

    2014-01-01

    With the rapid development of P2P technology, P2P IPTV applications have received more and more attention. And program resource distribution is very important to P2P IPTV applications. In order to collect IPTV program resources, a distributed multi-protocol crawler is proposed. And the crawler has collected more than 13 million pieces of information of IPTV programs from 2009 to 2012. In addition, the distribution of IPTV programs is independent and incompact, resulting in chaos of program names, which obstructs searching and organizing programs. Thus, we focus on characteristic analysis of program resources, including the distributions of length of program names, the entropy of the character types, and hierarchy depth of programs. These analyses reveal the disorderly naming conventions of P2P IPTV programs. The analysis results can help to purify and extract useful information from chaotic names for better retrieval and accelerate automatic sorting of program and establishment of IPTV repository. In order to represent popularity of programs and to predict user behavior and popularity of hot programs over a period, we also put forward an analytical model of hot programs. PMID:24772008

  15. Measurement and analysis of P2P IPTV program resource.

    PubMed

    Wang, Wenxian; Chen, Xingshu; Wang, Haizhou; Zhang, Qi; Wang, Cheng

    2014-01-01

    With the rapid development of P2P technology, P2P IPTV applications have received more and more attention. And program resource distribution is very important to P2P IPTV applications. In order to collect IPTV program resources, a distributed multi-protocol crawler is proposed. And the crawler has collected more than 13 million pieces of information of IPTV programs from 2009 to 2012. In addition, the distribution of IPTV programs is independent and incompact, resulting in chaos of program names, which obstructs searching and organizing programs. Thus, we focus on characteristic analysis of program resources, including the distributions of length of program names, the entropy of the character types, and hierarchy depth of programs. These analyses reveal the disorderly naming conventions of P2P IPTV programs. The analysis results can help to purify and extract useful information from chaotic names for better retrieval and accelerate automatic sorting of program and establishment of IPTV repository. In order to represent popularity of programs and to predict user behavior and popularity of hot programs over a period, we also put forward an analytical model of hot programs.

  16. Warm Core Structure and Mid-Level Intrusion in Hurricane Bonnie (1998) During Landfalling on 26 August 1998

    NASA Technical Reports Server (NTRS)

    Heymsfield, G. M.; Halverson, J.

    2004-01-01

    On 26 August 1998 during CAMEX-3, Hurricane Bonnie was overflown by the NASA ER-2 aircraft instrumented with the EDOP X-Band radar and other instrumentation. Bonnie was an asymmetric storm on this day with several prominent features during its brush with the East coast. One of these features was strong intrusion of dry air on the west side of the storm. During the interaction of this westerly shear with the storm, the precipitation band rotates cyclonically from northwest to the south of the storm center. In this paper, we examine the structure of this dry intrusion and its effect on the storm. The EDOP observations are analyzed along with dropsondes, flight-level observations (NASA DC-8 and NOAA P3), and satellite data. The most apparent feature of the EDOP observations are the strong shears in the interface between the western eyewall updraft, and the dry intrusion. Mammatus are formed along this interface reminiscent of convective rear inflows, and suggestive of intense drying of the air through subsidence. This observation as well as other aspects of the analysis are related to recent numerical simulations of Hurricane Bonnie.

  17. Systems-level response to point mutations in a core metabolic enzyme modulates genotype-phenotype relationship.

    PubMed

    Bershtein, Shimon; Choi, Jeong-Mo; Bhattacharyya, Sanchari; Budnik, Bogdan; Shakhnovich, Eugene

    2015-04-28

    Linking the molecular effects of mutations to fitness is central to understanding evolutionary dynamics. Here, we establish a quantitative relation between the global effect of mutations on the E. coli proteome and bacterial fitness. We created E. coli strains with specific destabilizing mutations in the chromosomal folA gene encoding dihydrofolate reductase (DHFR) and quantified the ensuing changes in the abundances of 2,000+ E. coli proteins in mutant strains using tandem mass tags with subsequent LC-MS/MS. mRNA abundances in the same E. coli strains were also quantified. The proteomic effects of mutations in DHFR are quantitatively linked to phenotype: the SDs of the distributions of logarithms of relative (to WT) protein abundances anticorrelate with bacterial growth rates. Proteomes hierarchically cluster first by media conditions, and within each condition, by the severity of the perturbation to DHFR function. These results highlight the importance of a systems-level layer in the genotype-phenotype relationship. PMID:25892240

  18. The evolution of Ga and As core levels in the formation of Fe/GaAs (001): A high resolution soft x-ray photoelectron spectroscopic study

    SciTech Connect

    Thompson, Jamie D. W.; Neal, James R.; Shen, Tiehan H.; Morton, Simon A.; Tobin, James G.; Dan Waddill, G.; Matthew, Jim A. D.; Greig, Denis; Hopkinson, Mark

    2008-07-15

    A high resolution soft x-ray photoelectron spectroscopic study of Ga and As 3d core levels has been conducted for Fe/GaAs (001) as a function of Fe thickness. This work has provided unambiguous evidence of substrate disrupting chemical reactions induced by the Fe overlayer--a quantitative analysis of the acquired spectra indicates significantly differing behavior of Ga and As during Fe growth, and our observations have been compared with existing theoretical models. Our results demonstrate that the outdiffusing Ga and As remain largely confined to the interface region, forming a thin intermixed layer. Whereas at low coverages Fe has little influence on the underlying GaAs substrate, the onset of substrate disruption when the Fe thickness reaches 3.5 A results in major changes in the energy distribution curves (EDCs) of both As and Ga 3d cores. Our quantitative analysis suggests the presence of two additional As environments of metallic character: one bound to the interfacial region and another which, as confirmed by in situ oxidation experiments, surface segregates and persists over a wide range of overlayer thickness. Analysis of the corresponding Ga 3d EDCs found not two, but three additional environments--also metallic in nature. Two of the three are interface resident whereas the third undergoes outdiffusion at low Fe coverages. Based on the variations of the integrated intensities of each component, we present a schematic of the proposed chemical makeup of the Fe/GaAs (001) system.

  19. The evolution of Ga and As core levels in the formation of Fe/GaAs (001):A high resolution soft x-ray photoelectron spectroscopic study

    SciTech Connect

    Thompson, Jamie; Neal, James; Shen, Tiehan; Morton, Simon; Tobin, James; Waddill, George Dan; Matthew, Jim; Greig, Denis; Hopkinson, Mark

    2008-07-14

    A high resolution soft x-ray photoelectron spectroscopic study of Ga and As 3d core levels has been conducted for Fe/GaAs (001) as a function of Fe thickness. This work has provided unambiguous evidence of substrate disrupting chemical reactions induced by the Fe overlayer--a quantitative analysis of the acquired spectra indicates significantly differing behavior of Ga and As during Fe growth, and our observations have been compared with existing theoretical models. Our results demonstrate that the outdiffusing Ga and As remain largely confined to the interface region, forming a thin intermixed layer. Whereas at low coverages Fe has little influence on the underlying GaAs substrate, the onset of substrate disruption when the Fe thickness reaches 3.5 Angstrom results in major changes in the energy distribution curves (EDCs) of both As and Ga 3d cores. Our quantitative analysis suggests the presence of two additional As environments of metallic character: one bound to the interfacial region and another which, as confirmed by in situ oxidation experiments, surface segregates and persists over a wide range of overlayer thickness. Analysis of the corresponding Ga 3d EDCs found not two, but three additional environments--also metallic in nature. Two of the three are interface resident whereas the third undergoes outdiffusion at low Fe coverages. Based on the variations of the integrated intensities of each component, we present a schematic of the proposed chemical makeup of the Fe/GaAs (001) system.

  20. Determining polarity and dislocation core structures at atomic level for epitaxial AlN/(0001)6H-SiC from a single image in HRTEM.

    PubMed

    Cui, Y X; Wang, Y M; Wen, C; Ge, B H; Li, F H; Chen, Y; Chen, H

    2013-03-01

    The polarity of epitaxial AlN film grown on (0001)6H-SiC and dislocation core structures in the film have been studied using a 200 kV LaB6 high-resolution transmission electron microscope of point resolution about 0.2 nm. A posterior image processing technique, the image deconvolution, was utilized to transform a single [21¯1¯0] image that does not intuitively represent the structure into the projected structure map. The adjacent Al and N projected atomic columns with the interatomic distance 0.109 nm can be distinguished from each other by analyzing the image contrast change with the sample thickness based on the pseudo-weak phase object approximation. This makes possible to derive the polarity and core structures of partial dislocations in the epitaxial AlN film at atomic level from a single image without relying on any other additional structure information. The atomic configurations for two partial dislocations containing a 10-atom ring and a 12-atom ring, respectively, have been attained. The method is available for II-VI and other III-V compounds. Its principle and procedure are briefly introduced.

  1. The Evolution of Ga and As Core Levels in the Formation of Fe/GaAs(001): A High Resolution Soft X-ray Photoelectron Spectroscopic Study

    SciTech Connect

    Thompson, J W; Neal, J R; Shen, T H; Morton, S A; Tobin, J G; Waddill, G D; Matthew, J D; Greig, D; Hopkinson, M

    2006-12-08

    A high resolution soft x-ray photoelectron spectroscopic study of Ga and As 3d core levels has been conducted for Fe/GaAs (001) as a function of Fe thickness. This work has provided unambiguous evidence of substrate disrupting chemical reactions induced by the Fe overlayer--a quantitative analysis of the acquired spectra indicates significantly differing behavior of Ga and As during Fe growth, and our observations have been compared with existing theoretical models. Our results demonstrate that the outdiffusing Ga and As remain largely confined to the interface region, forming a thin intermixed layer. Whereas at low coverages Fe has little influence on the underlying GaAs substrate, the onset of substrate disruption when the Fe thickness reaches 3.5 {angstrom} results in major changes in the energy distribution curves (EDCs) of both As and Ga 3d cores. Our quantitative analysis suggests the presence of two new As environments of metallic character; one bound to the interfacial region and another which, as confirmed by in-situ oxidation experiments, surface segregates and persists over a wide range of overlayer thickness. Analysis of the corresponding Ga 3d EDCs found not two, but three new environments--also metallic in nature. Two of the three are interface-resident whereas the third undergoes outdiffusion at low Fe coverages. Based on the variations of the integrated intensities of each component, we present a schematic of the proposed chemical make-up of the Fe/GaAs (001) system.

  2. Ab initio study of reactive collisions between Rb((2)S) or Rb((2)P) and OH(-)((1)Σ(+)).

    PubMed

    Kas, Milaim; Loreau, Jérôme; Liévin, Jacques; Vaeck, Nathalie

    2016-05-28

    A theoretical rate constant for the associative detachment reaction Rb((2)S) + OH(-)((1)Σ(+)) → RbOH((1)Σ(+)) + e(-) of 4 × 10(-10) cm(3) s(-1) at 300 K has been calculated. This result agrees with the experimental rate constant of 2-1 (+2)×10(-10)cm(3)s(-1) obtained by Deiglmayr et al. [Phys. Rev. A 86, 043438 (2012)] for a temperature between 200 K and 600 K. A Langevin-based dynamics which depends on the crossing point between the anion (RbOH(-)) and neutral (RbOH) potential energy surfaces has been used. The calculations were performed using the ECP28MDF effective core potential to describe the rubidium atom at the CCSD(T) level of theory and extended basis sets. The effect of ECPs and basis set on the height of the crossing point, and hence the rate constant, has been investigated. The temperature dependence of the latter is also discussed. Preliminary work on the potential energy surface for the excited reaction channel Rb((2)P) + OH(-)((1)Σ(+)) calculated at the CASSCF-icMRCI level of theory is presented. We qualitatively discuss the charge transfer and associative detachment reactions arising from this excited entrance channel.

  3. Ab initio study of reactive collisions between Rb(2S) or Rb(2P) and OH-(1Σ+)

    NASA Astrophysics Data System (ADS)

    Kas, Milaim; Loreau, Jérôme; Liévin, Jacques; Vaeck, Nathalie

    2016-05-01

    A theoretical rate constant for the associative detachment reaction Rb(2S) + OH-(1Σ+) → RbOH(1Σ+) + e- of 4 × 10-10 cm3 s-1 at 300 K has been calculated. This result agrees with the experimental rate constant of 2- 1 + 2 × 1 0 - 10 cm 3 s - 1 obtained by Deiglmayr et al. [Phys. Rev. A 86, 043438 (2012)] for a temperature between 200 K and 600 K. A Langevin-based dynamics which depends on the crossing point between the anion (RbOH-) and neutral (RbOH) potential energy surfaces has been used. The calculations were performed using the ECP28MDF effective core potential to describe the rubidium atom at the CCSD(T) level of theory and extended basis sets. The effect of ECPs and basis set on the height of the crossing point, and hence the rate constant, has been investigated. The temperature dependence of the latter is also discussed. Preliminary work on the potential energy surface for the excited reaction channel Rb(2P) + OH-(1Σ+) calculated at the CASSCF-icMRCI level of theory is presented. We qualitatively discuss the charge transfer and associative detachment reactions arising from this excited entrance channel.

  4. Ab initio study of reactive collisions between Rb((2)S) or Rb((2)P) and OH(-)((1)Σ(+)).

    PubMed

    Kas, Milaim; Loreau, Jérôme; Liévin, Jacques; Vaeck, Nathalie

    2016-05-28

    A theoretical rate constant for the associative detachment reaction Rb((2)S) + OH(-)((1)Σ(+)) → RbOH((1)Σ(+)) + e(-) of 4 × 10(-10) cm(3) s(-1) at 300 K has been calculated. This result agrees with the experimental rate constant of 2-1 (+2)×10(-10)cm(3)s(-1) obtained by Deiglmayr et al. [Phys. Rev. A 86, 043438 (2012)] for a temperature between 200 K and 600 K. A Langevin-based dynamics which depends on the crossing point between the anion (RbOH(-)) and neutral (RbOH) potential energy surfaces has been used. The calculations were performed using the ECP28MDF effective core potential to describe the rubidium atom at the CCSD(T) level of theory and extended basis sets. The effect of ECPs and basis set on the height of the crossing point, and hence the rate constant, has been investigated. The temperature dependence of the latter is also discussed. Preliminary work on the potential energy surface for the excited reaction channel Rb((2)P) + OH(-)((1)Σ(+)) calculated at the CASSCF-icMRCI level of theory is presented. We qualitatively discuss the charge transfer and associative detachment reactions arising from this excited entrance channel. PMID:27250305

  5. Kinetics of the Reactions of Cl((sup 2)P(sub J)) and Br((sup 2)P(sub 3/2)) with O3

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Kreutter, K. D.; Wine, P. H.

    1997-01-01

    A laser flash photolysis-resonance fluorescence technique has been employed to study the kinetics of the important stratospheric reactions Cl((sup 2)P(sub J)) + O3 yields ClO + O2 and Br((sup 2)P(sub 3/2)) + O3 yields BrO + O2 as a function of temperature. The temperature dependence observed for the Cl((sup 2)P(sub J)) + O3 reaction is nonArrhenius, but can be adequately described by the following two Arrhenius expressions (units are cu cm/(molecule.s), errors are 2 sigma and represent precision only): k(sub 1)(T) = (1.19 +/- 0.21) x 10(exp -11) exp[(-33 +/- 37)/T] for T = 189-269 K and k(sub 1)(T) = (2.49 +/- 0.38) x 10(exp -11) exp[(-233 +/- 46)/T] for 269-385 K. At temperatures below 230 K, the rate coefficients determined in this study are faster than any reported previously. Incorporation of our values for k(sub 1)(T) into stratospheric models would increase calculated ClO levels and decrease calculated HCI levels; hence the calculated efficiency of ClO catalyzed ozone destruction would increase. The temperature dependence observed for the Br((sup 2)P(sub 3/2)) + O3 reaction is adequately described by the following Arrhenius expression (units are cu cm/(molecule.s), errors are 2 sigma and represent precision only): k(sub 2)(T) = (1.50 +/- 0.16) x 10(exp -11)exp[(-775 +/- 30)/T for 195-392 K. While not in quantitative agreement with Arrhenius parameters reported in most previous studies, our results almost exactly reproduce the average of all earlier studies and therefore will not affect the choice of k(sub 2)(T) for use in modeling stratospheric BrO2 chemistry.

  6. 3s- and 3p-core level excitations in 3d-transition metal oxides from electron-energy-loss spectroscopy

    NASA Astrophysics Data System (ADS)

    Steiner, P.; Zimmermann, R.; Reinert, F.; Engel, Th.; Hüfner, S.

    1995-03-01

    3s- and 3p-core level excitations for a large number of 3d-transition metal oxides, with a formal 3d occupation from 3d0 to 3d10, have been measured by electron energy loss spectroscopy in reflection geometry (REELS) with primary energies 200 eV≤ E 0≤1600 eV. Their intensities decrease systematically with the formal 3d-count, classifying them as transitions to empty 3d-states. The structure of the 3s excitations is analysed in detail and is compared to the 3s-XPS photoemission spectra of the samples. This 3s-REELS structure and its change with the 3d occupation can be explained by the assumption that the excitation arises mainly from a 3s23dn→3s13dn+1 quadrupole transition.

  7. The Current Status of the Space Station Biological Research Project: a Core Facility Enabling Multi-Generational Studies under Slectable Gravity Levels

    NASA Astrophysics Data System (ADS)

    Santos, O.

    2002-01-01

    The Space Station Biological Research Project (SSBRP) has developed a new plan which greatly reduces the development costs required to complete the facility. This new plan retains core capabilities while allowing for future growth. The most important piece of equipment required for quality biological research, the 2.5 meter diameter centrifuge capable of accommodating research specimen habitats at simulated gravity levels ranging from microgravity to 2.0 g, is being developed by NASDA, the Japanese space agency, for the SSBRP. This is scheduled for flight to the ISS in 2007. The project is also developing a multi-purpose incubator, an automated cell culture unit, and two microgravity habitat holding racks, currently scheduled for launch in 2005. In addition the Canadian Space Agency is developing for the project an insect habitat, which houses Drosophila melanogaster, and provides an internal centrifuge for 1 g controls. NASDA is also developing for the project a glovebox for the contained manipulation and analysis of biological specimens, scheduled for launch in 2006. This core facility will allow for experimentation on small plants (Arabidopsis species), nematode worms (C. elegans), fruit flies (Drosophila melanogaster), and a variety of microorganisms, bacteria, yeast, and mammalian cells. We propose a plan for early utilization which focuses on surveys of changes in gene expression and protein structure due to the space flight environment. In the future, the project is looking to continue development of a rodent habitat and a plant habitat that can be accommodated on the 2.5 meter centrifuge. By utilizing the early phases of the ISS to broadly answer what changes occur at the genetic and protein level of cells and organisms exposed to the ISS low earth orbit environment, we can generate interest for future experiments when the ISS capabilities allow for direct manipulation and intervention of experiments. The ISS continues to hold promise for high quality, long

  8. K2P potassium channels, mysterious and paradoxically exciting.

    PubMed

    Goldstein, Steve A N

    2011-08-01

    New evidence reveals that the common electrolyte disorder hypokalemia can induce K2P1 channels that are normally selective for K+ to break the rules and conduct Na+. This defiant behavior leads to paradoxical depolarization of many cells in the heart, increasing the risk for lethal arrhythmia. The new research resolves a mystery uncovered 50 years ago and bestows an array of new riddles. Here, I discuss how K2P1 might achieve this alchemy--through stable residence of the K+ selectivity filter in a Na+-conductive state between its open and C-inactive configurations--and predict that other K+ channels and environmental stimuli will be discovered to produce the same excitatory misconduct. PMID:21868351

  9. A micro-payment architecture for P2P networks

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; Zhao, Zheng; Xiong, Xiao; Shi, Qingwei

    2007-09-01

    An important goal in P2P networks is that all peers provide resources. However, free riding and tragedy of common are real issues in P2P networks. To resolve these problems, most of the existing work is concerning probabilistic estimation to evaluate the trustworthiness or mechanism design to provide incentive. Instead of design a protocol to solve free riding, we build a micro-payment architecture for these existing protocols using virtual currency which can be more precisely measured and easily be replaced by reputation or other tokens. Our system can avoid from long-term trust learning interactions and high cost of collecting and analyzing reputation information. It can also provide peers incentive to truly report their connection type and security to malicious attacks.

  10. Supporting seamless mobility for P2P live streaming.

    PubMed

    Kim, Eunsam; Kim, Sangjin; Lee, Choonhwa

    2014-01-01

    With advent of various mobile devices with powerful networking and computing capabilities, the users' demand to enjoy live video streaming services such as IPTV with mobile devices has been increasing rapidly. However, it is challenging to get over the degradation of service quality due to data loss caused by the handover. Although many handover schemes were proposed at protocol layers below the application layer, they inherently suffer from data loss while the network is being disconnected during the handover. We therefore propose an efficient application-layer handover scheme to support seamless mobility for P2P live streaming. By simulation experiments, we show that the P2P live streaming system with our proposed handover scheme can improve the playback continuity significantly compared to that without our scheme.

  11. Supporting Seamless Mobility for P2P Live Streaming

    PubMed Central

    Kim, Eunsam; Kim, Sangjin; Lee, Choonhwa

    2014-01-01

    With advent of various mobile devices with powerful networking and computing capabilities, the users' demand to enjoy live video streaming services such as IPTV with mobile devices has been increasing rapidly. However, it is challenging to get over the degradation of service quality due to data loss caused by the handover. Although many handover schemes were proposed at protocol layers below the application layer, they inherently suffer from data loss while the network is being disconnected during the handover. We therefore propose an efficient application-layer handover scheme to support seamless mobility for P2P live streaming. By simulation experiments, we show that the P2P live streaming system with our proposed handover scheme can improve the playback continuity significantly compared to that without our scheme. PMID:24977171

  12. Determination of lead isotopes in a new Greenland deep ice core at the sub-picogram per gram level by thermal ionization mass spectrometry using an improved decontamination method.

    PubMed

    Han, Changhee; Burn-Nunes, Laurie J; Lee, Khanghyun; Chang, Chaewon; Kang, Jung-Ho; Han, Yeongcheol; Hur, Soon Do; Hong, Sungmin

    2015-08-01

    An improved decontamination method and ultraclean analytical procedures have been developed to minimize Pb contamination of processed glacial ice cores and to achieve reliable determination of Pb isotopes in North Greenland Eemian Ice Drilling (NEEM) deep ice core sections with concentrations at the sub-picogram per gram level. A PL-7 (Fuso Chemical) silica-gel activator has replaced the previously used colloidal silica activator produced by Merck and has been shown to provide sufficiently enhanced ion beam intensity for Pb isotope analysis for a few tens of picograms of Pb. Considering the quantities of Pb contained in the NEEM Greenland ice core and a sample weight of 10 g used for the analysis, the blank contribution from the sample treatment was observed to be negligible. The decontamination and analysis of the artificial ice cores and selected NEEM Greenland ice core sections confirmed the cleanliness and effectiveness of the overall analytical process.

  13. DNA Compaction by Yeast Mitochondrial Protein ABF2p

    SciTech Connect

    Friddle, R W; Klare, J E; Noy, A; Corzett, M; Balhorn, R; Baskin, R J; Martin, S S; Baldwin, E P

    2003-05-09

    We used high resolution Atomic Force Microscopy (AFM) to image compaction of linear and circular DNA by the yeast mitochondrial protein ABF2p , which plays a major role in maintaining mitochondrial DNA. AFM images show that protein binding induces drastic bends in the DNA backbone for both linear and circular DNA. At high concentration of ABF2p DNA collapses into a tight globular structure. We quantified the compaction of linear DNA by measuring the end-to-end distance of the DNA molecule at increasing concentrations of ABF2p. We also derived a polymer statistical mechanics model that gives quantitative description of compaction observed in our experiments. This model shows that a number of sharp bends in the DNA backbone is often sufficient to cause DNA compaction. Comparison of our model with the experimental data showed excellent quantitative correlation and allowed us to determine binding characteristics for ABF2. Our studies indicate that ABF2 compacts DNA through a novel mechanism that involves bending of DNA backbone. We discuss the implications of such a mechanism for mitochondrial DNA maintenance.

  14. Pure P2P mediation system: A mappings discovery approach

    NASA Astrophysics Data System (ADS)

    selma, El yahyaoui El idrissi; Zellou, Ahmed; Idri, Ali

    2015-02-01

    The information integration systems consist in offering a uniform interface to provide access to a set of autonomous and distributed information sources. The most important advantage of this system is that it allows users to specify what they want, rather than thinking about how to get the responses. The works realized in this area have particular leads to two major classes of integration systems: the mediation systems based on the paradigm mediator / adapter and peer to peer systems (P2P). The combination of both systems has led to a third type; is the mediation P2P systems. The P2P systems are large-scale systems, self-organized and distributed. They allow the resource management in a completely decentralized way. However, the integration of structured information sources, heterogeneous and distributed proves to be a complex problem. The objective of this work is to propose an approach to resolve conflicts and establish a mapping between the heterogeneous elements. This approach is based on clustering; the latter is to group similar Peers that share common information in the same subnet. Thus, to facilitate the heterogeneity, we introduced three additional layers of our hierarchy of peers: internal schema, external schema and Schema directory peer. We used linguistic techniques, and precisely the name correspondence technique, that is based on the similarity of names to propose a correspondence.

  15. A Measurement of g2p at Low Q2

    NASA Astrophysics Data System (ADS)

    Cummings, M.

    2016-02-01

    Jefferson Lab has been at the forefront of a program to study the polarized structure of nucleons using electron scattering. Measurements of the spin dependent structure functions, g1 and g2, have proven to be powerful tools in testing and understanding QCD. The neutron structure function g2n has been measured extensively in Hall A at Jefferson Lab over a wide range of Q2, but data for g2p remains scarce. This docment will discuss the g2p experiment, which ran in Hall A at Jefferson Lab in the spring of 2012, and will provide the first measurement of g2p in the resonance region; covering 0.02 < Q2 < 0.2 GeV2. The 0th moment of g2 provides a test of the Burkhardt-Cottingham sum rule, which states that the integral of g2 over the Bjorken scaling variable x goes to zero. This sum rule, valid for all values of Q2, has been satisfied for the neutron, but a violation is suggested for the proton at high Q2. The 2nd moment allows for a benchmark test of χPT at low Q2. Specifically, the behavior of the longitudinally-transverse spin polarizability (δLT), as χPT calculations of this quantity deviate significantly from the measured neutron data. This document will discuss the current status of the analysis along with preliminary results.

  16. Gas-to-cluster effects in S 2p-excited SF{sub 6}

    SciTech Connect

    Flesch, Roman; Serdaroglu, Ertugrul; Ruehl, Eckart; Brykalova, Xenia O.; Kan, Elena I.; Klyushina, Ekaterina S.; Krivosenko, Yuri S.; Pavlychev, Andrey A.

    2013-04-14

    High resolution X-ray spectroscopic studies on free SF{sub 6} molecules and SF{sub 6} clusters near the S 2p ionization thresholds are reported. Spectral changes occurring in clusters for the intense molecular-like S 2p{sub 1/2,3/2}{yields} 6a{sub 1g}-, 2t{sub 2g}-, and 4e{sub g}-resonances are examined in detail. Neither gas-to-cluster spectral shifts nor changes in peak shape are observed for the pre-edge 6a{sub 1g}-band. Significant changes in band shape and distinct gas-to-cluster shifts occur in the S 2p{sub 1/2,3/2}{yields} 2t{sub 2g}- and 4e{sub g}-transitions. These are found in the S 2p-ionization continua. The quasiatomic approach is used to assign the experimental results. It is shown that a convolution of asymmetric and symmetric contributions from Lorentzian and Gaussian line shapes allows us to model the spectral distribution of oscillator strength for the S 2p{sub 1/2,3/2}{yields} 2t{sub 2g}-, and 4e{sub g}-transitions. The asymmetry is due to trapping of the photoelectron within the finite size potential barrier. The Lorentzian contribution is found to be dominating in the line shape of the S 2p{yields} 2t{sub 2g}- and 4e{sub g}-bands. The spectroscopic parameters of the spin-orbit components of both the 2t{sub 2g}- and 4e{sub g}-bands are extracted and their gas-to-cluster changes are analyzed. The photoelectron trapping times in free and clustered SF{sub 6} molecules are determined. Specifically, it is shown that spectral changes in clusters reflected in core-to-valence-transitions are due to a superposition of the singly scattered photoelectron waves at the neighboring molecules with the primary and multiply scattered waves within the molecular cage.

  17. Thermal stability of the HfO2/SiO2 interface for sub-0.1 μm complementary metal-oxide-semiconductor gate oxide stacks: A valence band and quantitative core-level study by soft x-ray photoelectron spectroscopy

    NASA Astrophysics Data System (ADS)

    Barrett, N.; Renault, O.; Damlencourt, J.-F.; Martin, F.

    2004-12-01

    Synchrotron-radiation photoelectron spectroscopy is used to study the valence-band structure and the core-level photoemission spectra of HfO2 ultrathin films grown onto SiO2/Si substrates by atomic layer deposition (ALD). We determine the band offsets (valence and conduction) of HfO2 to Si as a function of postdeposition annealing treatments (under an inert N2 atmosphere or in situ in ultrahigh vacuum) and find a significant evolution, the conduction-band offset remaining larger than 1.5eV. The Si2p and the Hf4f core-level spectra give detailed information on the composition and the spatial extent of the interfacial Hf silicate layer formed between the SiO2 bottom oxide and the HfO2 ALD thin film. By a quantitative treatment of the Si2p core-level intensities, we examine the thermal stability of the interface silicate after postdeposition annealing under N2 and in situ annealing in ultrahigh vacuum (UHV), both at 800°C. The as-deposited layer gives rise to a HfO2/Hf0.35Si0.65O2/SiO2 stack with corresponding thicknesses of 0.74/0.51/0.73nm. After postdeposition annealing at 800°C in a N2 atmosphere, this becomes a HfO2/Hf0.31Si0.69O2/SiO2 stack with corresponding thicknesses of 0.71:0.58:0.91nm. In situ annealing in UHV, on the other hand, gives a HfO2/Hf0.35Si0.65O2/SiO2 stack with corresponding thicknesses of 0.65:0.70:0.76nm. The former favors an extension of both the silicate and the SiO2 interface layers, whereas the latter develops only the silicate layer.

  18. Tretinoin-loaded lipid-core nanocapsules decrease reactive oxygen species levels and improve bovine embryonic development during in vitro oocyte maturation.

    PubMed

    Lucas, Caroline Gomes; Remião, Mariana Härter; Komninou, Eliza Rossi; Domingues, William Borges; Haas, Cristina; Leon, Priscila Marques Moura de; Campos, Vinicius Farias; Ourique, Aline; Guterres, Silvia S; Pohlmann, Adriana R; Basso, Andrea Cristina; Seixas, Fabiana Kömmling; Beck, Ruy Carlos Ruver; Collares, Tiago

    2015-12-01

    In vitro oocyte maturation (IVM) protocols can be improved by adding chemical supplements to the culture media. Tretinoin is considered an important retinoid in embryonic development and its association with lipid-core nanocapsules (TTN-LNC) represents an innovative way of improving its solubility, and chemical stability, and reducing its toxicity. The effects of supplementing IVM medium with TTN-LNC was evaluated by analyzing production of reactive oxygen species (ROS), S36-phosphorilated-p66Shc levels and caspase activity in early embryonic development, and expression of apoptosis and pluripotency genes in blastocysts. The lowest concentration tested (0.25μM) of TTN-LNC generated higher blastocyst rate, lower ROS production and S36-p66Shc amount. Additionally, expression of BAX and SHC1 were lower in both non-encapsulated tretinoin (TTN) and TTN-LNC-treated groups. Nanoencapsulation allowed the use of smaller concentrations of tretinoin to supplement IVM medium thus reducing toxic effects related with its use, decreasing ROS levels and apoptose frequency, and improving the blastocyst rates.

  19. Disentangling Holocene lake level changes with a transect of lake sediment cores - a case study from Lake Fürstenseer See, northeastern Germany

    NASA Astrophysics Data System (ADS)

    Dietze, Elisabeth; Slowinski, Michal; Kienel, Ulrike; Zawiska, Izabela; Brauer, Achim

    2014-05-01

    Deciphering the main processes contributing to lake and landscape evolution in the northern central European lowlands on different temporal scales is one of the main targets of the Virtual Institute of Integrated Climate and Landscape Evolution Analysis (ICLEA) of the Helmholtz Association. In the context of future climatic changes especially the hydrological system is a vulnerable landscape component that showed considerably large changes in the recent past. The analysis of lake sediment archives can help to infer long-term dynamics of regional lake and groundwater levels, although available proxy information needs to be studied carefully, as water level changes are only one trigger. Lake Fürstenseer See (53°19'N, 13°12'E, lake level in 2009: 63.3 m a.s.l.) formed after the retreat of the Weichselian ice sheet in a subglacial channel in the direct forefront of the Pommerian ice margin. The ~2 km2 large lake (zmax = 24.5 m) has a (sub-) surficial catchment area of ~(20) 40 km2 including other smaller lakes and peatlands. In the past, the lake system was artificially dammed for the operation of water mills. Located within the well-drained sandur substrate, the lake levels vary with groundwater levels in response to hydrological and catchment-related groundwater recharge. Detrital matter input from fluvial activity can be excluded. Lake sediment cores at four sites along a transect down to 23 m water depth show distinct sediment facies patterns. Stratigraphic descriptions and non-destructive continuous micro-XRF scanning allowed the differentiation of the main sediment facies, which were microscopically described using thin sections. Quantification of total organic and inorganic matter (TOC, TIC, C/N-composition) and discontinuous macrorest, diatom and Cladocera analysis helped to approach the sedimentation history. Stable isotopes of (delta-180, delta-13C) were used for characterization of carbonates. A high amount of non-reworked terrestrial plant remains from

  20. Uncovering the behavior of Hf2Te2P and the candidate Dirac metal Zr2Te2P

    NASA Astrophysics Data System (ADS)

    Chen, K.-W.; Das, S.; Rhodes, D.; Memaran, S.; Besara, T.; Siegrist, T.; Manousakis, E.; Balicas, L.; Baumbach, R. E.

    2016-04-01

    Results are reported for single crystal specimens of Hf2Te2P and compared to its structural analogue Zr2Te2P, which was recently proposed to be a potential reservoir for Dirac physics [1]. Both materials are produced using the iodine vapor phase transport method and the resulting crystals are exfoliable. The bulk electrical transport and thermodynamic properties indicate Fermi liquid behavior at low temperature for both compounds. Quantum oscillations are observed in magnetization measurements for fields applied parallel but not perpendicular to the c-axis, suggesting that the Fermi surfaces are quasi-two dimensional. Frequencies are determined from quantum oscillations for several parts of the Fermi surfaces. Lifshitz-Kosevich fits to the temperature dependent amplitudes of the oscillations reveal small effective masses, with a particularly small value {{m}\\ast}=0.046{{m}0} for the α branch of Zr2Te2P. Electronic structure calculations are in good agreement with quantum oscillation results and illustrate the effect of a stronger spin-orbit interaction going from Zr to Hf. These results suggest that by using appropriate tuning parameters this class of materials may deepen the pool of novel Dirac phenomena.

  1. A Quantitative Content Analysis of the Common Core State Standards Compared to Missouri's Grade-Level Expectations Using the Revised Bloom's Taxonomy Framework

    ERIC Educational Resources Information Center

    Gallia, Toni

    2012-01-01

    With the pressure in education to develop a 21st century learner with higher-level thinking skills, many educators connected previous state curriculum to the Common Core State Standards (CCSS). Missouri's Department of Education experts paired the previous state's curriculum known as the Missouri Grade Level Expectations (MO GLEs) with a…

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

    PubMed

    Chen, Lei; Liu, Liangyu; Wang, Mingpeng; Fu, Jiafang; Zhang, Zhaojie; Hou, Jin; Bao, Xiaoming

    2013-01-01

    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.

  3. Transitions 2s/2/ 2p/k/ - 2s 2p/k+1/ of the F I, O I, and N I isoelectronic sequences. [in laser plasma spectra

    NASA Technical Reports Server (NTRS)

    Doschek, G. A.; Cowan, R. D.; Cohen, L.; Feldman, U.

    1974-01-01

    Transitions of the type 2s/2/ 2p/k/ - 2s 2p/k+1/ have been identified for the elements from titanium through nickel for ions of the fluorine, oxygen, and nitrogen isoelectronic sequences. Wavelengths, visual intensity estimates, and energies are given. The energy differences of levels of the ground configuration are compared with predictions based on semiempirical equations derived by Edlen. Some of the lines of these isoelectronic sequences should be strong lines in solar-flare spectra.

  4. Coralloid Co2P2O7 Nanocrystals Encapsulated by Thin Carbon Shells for Enhanced Electrochemical Water Oxidation.

    PubMed

    Chang, Yingxue; Shi, Nai-En; Zhao, Shulin; Xu, Dongdong; Liu, Chunyan; Tang, Yu-Jia; Dai, Zhihui; Lan, Ya-Qian; Han, Min; Bao, Jianchun

    2016-08-31

    Core-shell nanohybrids containing cheap inorganic nanocrystals and nanocarbon shells are promising electrocatalysts for water splitting or other renewable energy options. Despite that great progress has been achieved, biomimetic synthesis of metal phosphates@nanocarbon core-shell nanohybrids remains a challenge, and their use for electrocatalytic oxygen evolution reaction (OER) has not been explored. In this paper, novel nanohybrids composed of coralloid Co2P2O7 nanocrystal cores and thin porous nanocarbon shells are synthesized by combination of the structural merits of supramolecular polymer gels and a controllable thermal conversion technique, i.e., temperature programmable annealing of presynthesized supramolecular polymer gels that contain cobalt salt and phytic acid under a proper gas atmosphere. Electrocatalytic tests in alkaline solution show that such nanohybrids exhibit greatly enhanced electrocatalytic OER performance compared with that of Co2P2O7 nanostructure. At a current density of 10 mA cm(-2), their overpotential is 0.397 V, which is much lower than that of Co2P2O7 nanostructures, amorphous Co-Pi nanomaterials, Co(PO3)2 nanosheets, Pt/C, and some reported OER catalysts, and close to that of commercial IrO2. Most importantly, both of their current density at the overpotential over 0.40 V and durability are superior to those of IrO2 catalyst. As revealed by a series of spectroscopic and electrochemical analyses, their enhanced electrocatalytic performance results from the presence of thin porous nanocarbon shells, which not only improve interfacial electron penetration or transfer dynamics but also vary the coordination environment and increase the number of active 5-coordinated Co(2+) sites in Co2P2O7 cores. PMID:27500553

  5. Quantitative hepatitis B core antibody level is associated with inflammatory activity in treatment-naïve chronic hepatitis B patients.

    PubMed

    Li, Min-Ran; Lu, Jian-Hua; Ye, Li-Hong; Sun, Xing-Li; Zheng, Yan-Hua; Liu, Zhi-Quan; Zhang, Hai-Cong; Liu, Yun-Yan; Lv, Ying; Huang, Yan; Dai, Er-Hei

    2016-08-01

    Previous studies have shown that hepatitis B core antibody (anti-HBc) levels vary during different phases of disease in treatment-naïve chronic hepatitis B (CHB) patients and can be used as a predictor of both interferon-α and nucleoside analogue therapy response. However, there is no information on the association between the quantitative serum anti-HBc (qAnti-HBc) level and liver inflammation in CHB patients. Therefore, we investigated these relationships in a large cohort of treatment-naïve CHB patients. A total of 624 treatment-naïve CHB patients were included in the study. The serum qAnti-HBc level was moderately correlated with ALT and AST levels (P < 0.001) in both hepatitis B e antigen-positive (HBeAg [+]) and HBeAg-negative (HBeAg [-]) CHB patients. CHB patients with no to mild inflammation (G0-1) had significantly lower serum qAnti-HBc levels than patients with moderate to severe inflammation (G2-4) (P < 0.001). Receiver operating characteristic analysis suggested that a serum qAnti-HBc cut-off value of 4.36 log10 IU/mL provided a sensitivity of 71.68%, specificity of 73.81%, positive predictive value of 78.43%, and negative predictive value of 66.24% in HBeAg (+) CHB patients with moderate to severe inflammation (G≥2). A cut-off value of 4.62 log10 IU/mL provided a sensitivity of 54.29%, specificity of 90.00%, positive predictive value of 95.00%, and negative predictive value of 36.00% in HBeAg (-) CHB patients with moderate to severe inflammation (G≥2). Serum qAnti-HBc levels were positively associated with liver inflammation grade. Furthermore, we identified optimal serum qAnti-HBc cut-off values for the prediction of inflammation activity in both HBeAg (+) and HBeAg (-) treatment-naïve CHB patients. PMID:27559949

  6. Theoretical Stark widths and shifts of spectral lines of 2p5nf and 2p55g configurations of Mg III

    NASA Astrophysics Data System (ADS)

    Moreno-Díaz, Cristina; Alonso-Medina, Aurelia; Colón, Cristóbal

    2014-11-01

    In this paper, we report theoretical Stark widths and shifts calculated using the Griem semi-empirical approach, which corresponds to 111 spectral lines of Mg III. The values of these Stark broadening parameters of spectral lines that arise from levels of 2p5nf and 2p55g configurations of Mg III are presented in the literature for the first time. The aim of this work is to provide values to estimate the electron density of plasma Mg III in astrophysics and industrial applications. The data are presented for the temperatures T = 0.5-10.0 (104 K) and for an electron density of 1017 cm-3. The matrix of elements used in these calculations has been determined from 23 configurations of Mg III: 2s22p6, 2s22p53p, 2s22p54p, 2s22p54f and 2s22p55f for the even parity and 2s22p5ns (n = 3-6), 2s22p5nd (n = 3-9), 2s22p55g and 2s2p6np (n = 3-8) for the odd parity. For the intermediate coupling calculations, we use the standard method of least square fitting from experimental energy levels by means of Cowan’s computer code. Lines with wavelengths of 134.6460, 135.2800, 189.0380, 190.0043, 192.8424, 408.2939 and 409.4375 nm have high probabilities and also have high values of broadening. Therefore, these lines can be used in some applications. A common regularity for the Stark width of the 189.038 nm spectral line of Mg III is discussed.

  7. N-Myristoylation regulates the axonal distribution of the fragile X-related protein FXR2P

    PubMed Central

    Stackpole, Emily E.; Akins, Michael R.; Fallon, Justin R.

    2014-01-01

    Fragile X Syndrome, the leading cause of inherited intellectual disability and autism, is caused by loss of function of Fragile X mental retardation protein (FMRP). FMRP is an RNA binding protein that regulates local protein synthesis in the somatodendritic compartment. However, emerging evidence also indicates important roles for FMRP in axonal and presynaptic function. In particular, FMRP and its homolog FXR2P localize axonally and presynaptically to discrete endogenous structures in the brain termed Fragile X granules (FXGs). FXR2P is a component of all FXGs and is necessary for the axonal and presynaptic localization of FMRP to these structures. We therefore sought to identify and characterize structural features of FXR2P that regulate its axonal localization. Sequence analysis reveals that FXR2P harbors a consensus N-terminal myristoylation sequence (MGXXXS) that is absent in FMRP. Using click chemistry with wild type and an unmyristoylatable G2A mutant we demonstrate that FXR2P is N-myristoylated on glycine 2, establishing it as a lipid-modified RNA binding protein. To investigate the role of FXR2P N-myristoylation in neurons we generated fluorescently tagged wild type and unmyristoylatable FXR2P (WT and G2A, respectively) and expressed them in primary cortical cultures. Both FXR2PWT and FXR2PG2A are expressed at equivalent overall levels and are capable of forming FMRP-containing axonal granules. However, FXR2PWT granules are largely restricted to proximal axonal segments while granules formed with unmyristoylatable FXR2PG2A are localized throughout the axonal arbor, including in growth cones. These studies indicate that N-terminal myristoylation of the RNA binding protein FXR2P regulates its localization within the axonal arbor. Moreover, since FMRP localization within axonal domains requires its association with FXR2P, these findings suggest that FXR2P lipid modification is a control point for the axonal and presynaptic distribution of FMRP. PMID:25109237

  8. Spectrometer Optics Calibration for Jefferson Lab g2^p Experiment

    NASA Astrophysics Data System (ADS)

    Gu, Chao

    2013-04-01

    The proton spin-dependent structure function g2^p in the resonance region has been measured in a recent experiment at Jefferson Lab's Hall A. The goal of this experiment is to determine the g2^p structure function in the Q^2 region of 0.02-0.20 GeV^2 by using a transversely polarized NH3 target. The Hall A High Resolution Spectrometers (HRS) were used to provide an inclusive measurement of scattered electrons at 5.69^o. A pair of septum magnets were used to bend the 5.69^o scatted electrons into the 12.5^o spectrometers. A full optics calibration of the spectrometer is required to extract the kinematic quantities at the interaction vertex. However, the calibration procedure is challenging due to the complications from the strong transverse target field (2.5 T and 5.0 T) and the varied field configurations of the septum magnets. The details of the optics calibration and the progress will be described in this talk.

  9. KSi2P3: A new layered phosphidopolysilicate (IV)

    NASA Astrophysics Data System (ADS)

    Feng, Kai; Kang, Lei; Yin, Wenlong; Hao, Wenyu; Lin, Zheshuai; Yao, Jiyong; Wu, Yicheng

    2013-09-01

    A new ternary phosphidopolysilicate (IV), KSi2P3, has been synthesized by high temperature solid state reaction. The compound crystallizes in a new structure type in the monoclinic space group C2/c with a=10.1327(5) Å, b=10.1382(5) Å, c=21.1181(10) Å, β=96.88(0)°, and Z=8. In the structure, all SiP4 tetrahedra are connected with each other by corner-sharing P atoms to form [P3]-∞2 layers, which are stacked along c direction and separated by K+ cations. The two-dimensional structure of KSi2P3 contrasts with those of the two known members in the ternary A/Si/P (A=alkali metal) system, namely Na5SiP3 (zero-dimensional) and K2SiP2 (one-dimensional), which contains less amount of Si. The band gap deduced from UV-vis-IR diffuse reflectance spectrum is 1.72 eV.

  10. Fragrance material review on 2-p-tolylethanol.

    PubMed

    Scognamiglio, J; Jones, L; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2-p-tolylethanol when used as a fragrance ingredient is presented. 2-p-tolylethanol is a member of the fragrance structural group Aryl Alkyl Alcohols and is a primary alcohol. The AAAs are a structurally diverse class of fragrance ingredients that includes primary, secondary, and tertiary alkyl alcohols covalently bonded to an aryl (Ar) group, which may be either a substituted or unsubstituted benzene ring. The common structural element for the AAA fragrance ingredients is an alcohol group-C-(R1)(R2)OH and generically the AAA fragrances can be represented as an Ar-C-(R1)(R2)OH or Ar-Alkyl-C-(R1)(R2)OH group. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. A safety assessment of the entire Aryl Alkyl Alcohols will be published simultaneously with this document; please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all other branched chain saturated alcohols in fragrances.

  11. The RP-Mdm2-p53 Pathway and Tumorigenesis

    PubMed Central

    Miliani de Marval, Paula L.; Zhang, Yanping

    2011-01-01

    The dynamic processes of cell growth and division are under constant surveillance. As one of the primary “gatekeepers” of the cell, the p53 tumor suppressor plays a major role in sensing and responding to a variety of stressors to maintain cellular homeostasis. Recent studies have shown that inhibition of ribosomal biogenesis can activate p53 through ribosomal protein (RP)-mediated suppression of Mdm2 E3 ligase activity. Mutations in Mdm2 that disrupt RP binding have been detected in human cancers; however, the physiological significance of the RP-Mdm2 interaction is not completely understood. We generated mice carrying a single cysteine-to-phenylalanine substitution in the central zinc finger of Mdm2 (Mdm2C305F) that disrupts Mdm2’s binding to RPL11 and RPL5. Despite being developmentally normal and maintaining an intact p53 response to DNA damage, the Mdm2C305F mice demonstrate a diminished p53 response to perturbations in ribosomal biogenesis, providing the first in vivo evidence for an RP-Mdm2-p53 signaling pathway. Here we review some recent studies about RP-Mdm2-p53 signaling and speculate on the relevance of this pathway to human cancer. PMID:21406728

  12. The Complex Core Level Spectra of CeO2: An Analysis in Terms of Atomic and Charge Transfer Effects

    SciTech Connect

    Bagus, Paul S; Nelin, Constance J; Ilton, Eugene S; Baron, Martin; Abbott, Heather; Primorac, Elena; Kuhlenbeck, Helmut; Shaikhutdinov, Shamil; Freund, Hans-Joachim

    2010-03-05

    We present a rigorous parameter-free theoretical treatment of the Ce 4s and 5s photoelectron spectra of CeO2. In the currently accepted model the satellite structure in the photoelectron spectra is explained in terms of a mixed valence (Ce 4f0 O 2p6, Ce 4f1 O 2p5, and Ce 4f2 O 2p4) configurations. We show that charge transfer (CT) into Ce 5d as well as configurations involving intra-atomic movement of charge must be considered in addition and compute their contributions to the spectra.

  13. Identification of lysines within membrane-anchored Mga2p120 that are targets of Rsp5p ubiquitination and mediate mobilization of tethered Mga2p90

    PubMed Central

    Bhattacharya, Sabyasachi; Shcherbik, Natalia; Vasilescu, Julian; Smith, Jeffrey C.; Figeys, Daniel; Haines, Dale S.

    2009-01-01

    Summary Mga2p90 is an endoplasmic reticulum (ER) localized transcription factor that is released from the ER membrane by a unique ubiquitin-dependent mechanism. Mga2p90 mobilization requires poly-ubiquitination of its associating membrane-bound Mga2p120 anchor and subsequent Mga2p120-Mga2p90 complex disassembly that is mediated by ATPase Cdc48p and its heteromeric ubiquitin-binding adaptor Npl4p-Ufd1p. Although previous studies have identified the ubiquitin ligase (i.e. Rsp5p) and ligase binding site on Mga2p120 that play a role in this process, the amino acids of Mga2p120 that are targets of ubiquitination and promote Mga2p90 mobilization are unknown. We have identified using mass spectrometry analysis of in vitro ubiquitinated Mga2p120-Mga2p90 complex that lysines 983 and 985 contained within the carboxy-terminal domain of Mga2p120 are Rsp5p-directed ubiquitin conjugation sites. Mutation of these residues as well as proximally located lysine 980 results in suppression of Mga2p120 ubiquitination in vitro and in vivo, inefficient liberation of Mga2p90 by Cdc48pNpl4p/Ufd1p in vitro, and ER retention of Mga2p in cells. Moreover, mga2Δ/spt23ts harboring Rsp5p binding and conjugation mga2 mutants express low OLE1 (an Mga2p90 target gene) transcripts and display reduced growth. We conclude that residues 980, 983 and 985 are targets of Rsp5p-induced poly-ubiquitination and mediate Cdc48pNpl4p/Ufd1p-dependent Mga2p90-Mga2p120 separation and Mga2p90 mobilization. PMID:19061897

  14. Heterogeneous and hyperfine interactions between valence states of molecular iodine correlating with the I(2P1/2) + I(2P1/2) dissociation limit

    NASA Astrophysics Data System (ADS)

    Baturo, Vera V.; Cherepanov, Igor N.; Lukashov, Sergey S.; Poretsky, Sergey A.; Pravilov, Anatoly M.; Zhironkin, Anatoly I.

    2016-05-01

    Detailed analysis of interactions between all 0g + , 1u, and 0u - weakly bound states of iodine molecule correlating with the I(2P1/2) + I(2P1/2) (bb) dissociation limit has been performed. For this purpose, the 0u - (bb) state has been described using analysis of rotationally resolved excitation spectra of luminescence from the g 0g - state populated in a three-step three-color perturbation facilitated excitation scheme via the 0u - state. Energies of 41 rovibrational levels, molecular constants, and potential energy curve have been determined. Energy gaps between closest rovibrational levels of the 0u - and 0g + , 1u (bb) states are found to be large, ˜6 cm-1. However, interaction of all three 0g + , 1u, and 0u - (bb) states has been observed. It has been found that the 0u - and 1u electronic states are mixed by heterogeneous interactions, while their mixing with the 0g + one is due to hyperfine interactions predominantly. Admixture coefficients and electronic matrix elements of the coupling between the 0g + ˜1u, 0g + ˜ 0u - , and 0u - ˜1u states have been estimated.

  15. Information Orientation, Information Technology Governance, and Information Technology Service Management: A Multi-Level Approach for Teaching the MBA Core Information Systems Course

    ERIC Educational Resources Information Center

    Beachboard, John; Aytes, Kregg

    2011-01-01

    Core MBA IT courses have tended to be survey courses that cover important topics but often do not sufficiently engage students. The result is that many top-ranked MBA programs have not found such courses useful enough to include in their core MBA requirements. In this paper, we present a design of an MBA course emphasizing information technology…

  16. Kinetics of the Reactions of F((sup 2)P) and Cl((sup 2)P) with HNO3

    NASA Technical Reports Server (NTRS)

    Wine, P. H.; Wells, J. R.; Nicovich, J. M.

    1997-01-01

    The kinetics of the reactions of HNO3 with fluorine (k(sub 1)) and Chlorine (k(sub 2)) atoms have been studied by using a time-resolved long-path laser absorption technique to monitor the appearance of product NO3 radicals following 351-nm pulsed laser photolysis of X2/HNO3/He mixtures (X = F,Cl). Absolute rate coefficients for the F((sup 2)P) + HNO reaction have been determined over the temperature range 260-373 K. Between 260 and 320 K, the data are adequately represented by the Arrhenius expression k(sub 1)(T) = (6.0 +/- 2.6) x 10(exp -12) exp[(40 +/- 120)/T]cu cm/(molecule.s). Between 335 and 373 K, the rate coefficient is found to be (2.0 +/- 0.3) x 10(exp -11)cu cm/(molecule.s) independent of temperature. The observed temperature dependence suggests that reaction proceeds via competing direct abstraction and complex pathways. No NO3 production was observed in the experiments with X equals Cl, thus establishing that k(sub 2)(298 K) is less than 2 x 10(exp -16) cu cm/(molecule.s). The Cl((sup 2)P) + HNO reaction was also investigated by using a pulsed laser photolysis-resonance fluorescence technique to monitor the decay of Cl((sup 2)P). Upper limit values for k(sub 2) obtained from these experiments, in units of 10(exp -16)cu cm/(molecule.s), are 13 at 298 K and 10 at 400 K.

  17. The influence of oxygen adsorption on the NEXAFS and core-level XPS spectra of the C{sub 60} derivative PCBM

    SciTech Connect

    Brumboiu, Iulia Emilia Eriksson, Olle; Brena, Barbara; Ericsson, Leif; Hansson, Rickard; Moons, Ellen

    2015-02-07

    Fullerenes have been a main focus of scientific research since their discovery due to the interesting possible applications in various fields like organic photovoltaics (OPVs). In particular, the derivative [6,6]-phenyl-C{sub 60}-butyric acid methyl ester (PCBM) is currently one of the most popular choices due to its higher solubility in organic solvents compared to unsubstituted C{sub 60}. One of the central issues in the field of OPVs is device stability, since modules undergo deterioration (losses in efficiency, open circuit voltage, and short circuit current) during operation. In the case of fullerenes, several possibilities have been proposed, including dimerization, oxidation, and impurity related deterioration. We have studied by means of density functional theory the possibility of oxygen adsorption on the C{sub 60} molecular moiety of PCBM. The aim is to provide guidelines for near edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS) measurements which can probe the presence of atomic or molecular oxygen on the fullerene cage. By analysing several configurations of PCBM with one or more adsorbed oxygen atoms, we show that a joint core level XPS and O1s NEXAFS investigation could be effectively used not only to confirm oxygen adsorption but also to pinpoint the bonding configuration and the nature of the adsorbate.

  18. First-principle calculation of core level binding energies of Li{sub x}PO{sub y}N{sub z} solid electrolyte

    SciTech Connect

    Guille, Émilie; Vallverdu, Germain Baraille, Isabelle

    2014-12-28

    We present first-principle calculations of core-level binding energies for the study of insulating, bulk phase, compounds, based on the Slater-Janak transition state model. Those calculations were performed in order to find a reliable model of the amorphous Li{sub x}PO{sub y}N{sub z} solid electrolyte which is able to reproduce its electronic properties gathered from X-ray photoemission spectroscopy (XPS) experiments. As a starting point, Li{sub 2}PO{sub 2}N models were investigated. These models, proposed by Du et al. on the basis of thermodynamics and vibrational properties, were the first structural models of Li{sub x}PO{sub y}N{sub z}. Thanks to chemical and structural modifications applied to Li{sub 2}PO{sub 2}N structures, which allow to demonstrate the relevance of our computational approach, we raise an issue concerning the possibility of encountering a non-bridging kind of nitrogen atoms (=N{sup −}) in Li{sub x}PO{sub y}N{sub z} compounds.

  19. New Enzyme Immunoassay for Detection of Hepatitis B Virus Core Antigen (HBcAg) and Relation between Levels of HBcAg and HBV DNA

    PubMed Central

    Kimura, Tatsuji; Rokuhara, Akinori; Matsumoto, Akihiro; Yagi, Shintaro; Tanaka, Eiji; Kiyosawa, Kendo; Maki, Noboru

    2003-01-01

    A new enzyme immunoassay specific for hepatitis B virus (HBV) core antigen (HBcAg) was developed. In order to detect HBcAg, specimens were pretreated with detergents to release HBcAg from the HBV virion and disassemble it to dimers, and simultaneously, the treatment inactivated anti-HBc antibodies. HBcAg detected by the assay peaked with HBV DNA in density gradient fractions of HBV-positive sera. The assay showed a wide detection range from 2 to 100,000 pg/ml. We observed no interference from anti-HBc antibody or blood components, but the assay was inhibited by very high concentrations (>1 μg/ml; corresponding to 80 signal/cutoff) of HBeAg. When the cutoff value was tentatively set at 4 pg/ml, all healthy control (HBsAg and HBV DNA negative, n = 160) and anti-hepatitis C virus-positive (n = 55) sera were identified as negative. HBcAg concentrations correlated very closely with HBV DNA (r = 0.946, n = 145) in 216 samples from 72 hepatitis B patients. In seroconversion panels, HBcAg concentrations changed in parallel with HBV DNA levels. The assay, therefore, offers a simple method for monitoring hepatitis B patients. With a series of sera during lamivudine therapy, HBV DNA levels fell sharply and the HBcAg concentration also decreased, but the change in HBcAg was smaller and more gradual. The supposed mechanism of these changes and their clinical significance are discussed. PMID:12734224

  20. Complete nucleotide sequence analysis of plasmids in strains of Staphylococcus aureus clone USA300 reveals a high level of identity among isolates with closely related core genome sequences.

    PubMed

    Kennedy, Adam D; Porcella, Stephen F; Martens, Craig; Whitney, Adeline R; Braughton, Kevin R; Chen, Liang; Craig, Carly T; Tenover, Fred C; Kreiswirth, Barry N; Musser, James M; DeLeo, Frank R

    2010-12-01

    A community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strain known as pulsed-field type USA300 (USA300) is epidemic in the United States. Previous comparative whole-genome sequencing studies demonstrated that there has been recent clonal emergence of a subset of USA300 isolates, which comprise the epidemic clone. Although the core genomes of these isolates are closely related, the level of diversity among USA300 plasmids was not resolved. Inasmuch as these plasmids might contribute to significant gene diversity among otherwise closely related USA300 isolates, we performed de novo sequencing of endogenous plasmids from 10 previously characterized USA300 clinical isolates obtained from different geographic locations in the United States. All isolates tested contained small (2- to 3-kb) and/or large (27- to 30-kb) plasmids. The large plasmids encoded heavy metal and/or antimicrobial resistance elements, including those that confer resistance to cadmium, bacitracin, macrolides, penicillin, kanamycin, and streptothricin, although all isolates were sensitive to minocycline, doxycycline, trimethoprim-sulfamethoxazole, vancomycin, teicoplanin, and linezolid. One of the USA300 isolates contained an archaic plasmid that encoded staphylococcal enterotoxins R, J, and P. Notably, the large plasmids (27 to 28 kb) from 8 USA300 isolates--those that comprise the epidemic USA300 clone--were virtually identical (99% identity) and similar to a large plasmid from strain USA300_TCH1516 (a previously sequenced USA300 strain from Houston, TX). These plasmids are largely divergent from the 37-kb plasmid of FPR3757, the first sequenced USA300 strain. The high level of plasmid sequence identity among the majority of closely related USA300 isolates is consistent with the recent clonal emergence hypothesis for USA300.

  1. Molecular Orbital Simulations of Metal 1s2p Resonant Inelastic X-ray Scattering.

    PubMed

    Guo, Meiyuan; Källman, Erik; Sørensen, Lasse Kragh; Delcey, Mickaël G; Pinjari, Rahul V; Lundberg, Marcus

    2016-07-28

    For first-row transition metals, high-resolution 3d electronic structure information can be obtained using resonant inelastic X-ray scattering (RIXS). In the hard X-ray region, a K pre-edge (1s→3d) excitation can be followed by monitoring the dipole-allowed Kα (2p→1s) or Kβ (3p→1s) emission, processes labeled 1s2p or 1s3p RIXS. Here the restricted active space (RAS) approach, which is a molecular orbital method, is used for the first time to study hard X-ray RIXS processes. This is achieved by including the two sets of core orbitals in different partitions of the active space. Transition intensities are calculated using both first- and second-order expansions of the wave vector, including, but not limited to, electric dipoles and quadrupoles. The accuracy of the approach is tested for 1s2p RIXS of iron hexacyanides [Fe(CN)6](n-) in ferrous and ferric oxidation states. RAS simulations accurately describe the multiplet structures and the role of 2p and 3d spin-orbit coupling on energies and selection rules. Compared to experiment, relative energies of the two [Fe(CN)6](3-) resonances deviate by 0.2 eV in both incident energy and energy transfer directions, and multiplet splittings in [Fe(CN)6](4-) are reproduced within 0.1 eV. These values are similar to what can be expected for valence excitations. The development opens the modeling of hard X-ray scattering processes for both solution catalysts and enzymatic systems. PMID:27398775

  2. The Role of Vibrational Excitation on the Dynamics of the F(^2P) + HCl → FH + Cl(2P) Hydrogen-Transfer Reaction

    NASA Astrophysics Data System (ADS)

    Ray, Sara E.; Vissers, G. W. M.; McCoy, Anne B.

    2010-06-01

    Recently, open-shell systems have gained interest in experimental and theoretical science. What proves interesting about these open-shell systems is that the potential energy surfaces often contain a van der Waals well in the reactant or product channel that allows researchers to probe the pre-reactive species. Here we present the results of time-dependent quantum wave packet calculations on the asymmetric hydrogen-transfer reaction of F(^SUP>2P) + HCl. In these calculations, the reaction is initiated by vibrationally exciting the HCl stretching motion of the pre-reactive F\\cdotsHCl complex in the van der Waals well. The wave packet is propagated on a three-dimensional, fully coupled potential energy surface that has been constructed based on electronic energies calculated at the multi-reference configuration interation+Davidson correction (MRCI+Q) level of theory with an aug-cc-pVnZ (n=2,3,4) basis. Product state distributions were calculated for reactions initiated in the first three vibrationally excited states of HCl, v=1, 2, and 3. Specifically, we analyzed the final electronic, vibrational, and rotational distributions. Previous studies on the hydrogen-transfer reaction of the Cl(^2P) + HCl system focused on whether vibrational excitation of the HCl stretch would promote the reaction and if so, how the reaction dynamics reflect the coupling among the diabatic potential surfaces that describe this system. We also compare our F(^2P) + HCl results to those of this related system. M. P. Deskevich, M. Y. Hayes, K. Takahashi, R. T. Skodje, and D. J. Nesbitt J. Chem. Phys., 124(22) 224303 (2006) G. W. M. Vissers and A. B. McCoy J. Phys Chem. A, 110 5978 (2006)

  3. P2P proteomics -- data sharing for enhanced protein identification

    PubMed Central

    2012-01-01

    Background In order to tackle the important and challenging problem in proteomics of identifying known and new protein sequences using high-throughput methods, we propose a data-sharing platform that uses fully distributed P2P technologies to share specifications of peer-interaction protocols and service components. By using such a platform, information to be searched is no longer centralised in a few repositories but gathered from experiments in peer proteomics laboratories, which can subsequently be searched by fellow researchers. Methods The system distributively runs a data-sharing protocol specified in the Lightweight Communication Calculus underlying the system through which researchers interact via message passing. For this, researchers interact with the system through particular components that link to database querying systems based on BLAST and/or OMSSA and GUI-based visualisation environments. We have tested the proposed platform with data drawn from preexisting MS/MS data reservoirs from the 2006 ABRF (Association of Biomolecular Resource Facilities) test sample, which was extensively tested during the ABRF Proteomics Standards Research Group 2006 worldwide survey. In particular we have taken the data available from a subset of proteomics laboratories of Spain's National Institute for Proteomics, ProteoRed, a network for the coordination, integration and development of the Spanish proteomics facilities. Results and Discussion We performed queries against nine databases including seven ProteoRed proteomics laboratories, the NCBI Swiss-Prot database and the local database of the CSIC/UAB Proteomics Laboratory. A detailed analysis of the results indicated the presence of a protein that was supported by other NCBI matches and highly scored matches in several proteomics labs. The analysis clearly indicated that the protein was a relatively high concentrated contaminant that could be present in the ABRF sample. This fact is evident from the information that

  4. Introns Regulate Gene Expression in Cryptococcus neoformans in a Pab2p Dependent Pathway

    PubMed Central

    Goebels, Carolin; Thonn, Aline; Gonzalez-Hilarion, Sara; Rolland, Olga; Moyrand, Frederique; Beilharz, Traude H.; Janbon, Guilhem

    2013-01-01

    Most Cryptococccus neoformans genes are interrupted by introns, and alternative splicing occurs very often. In this study, we examined the influence of introns on C. neoformans gene expression. For most tested genes, elimination of introns greatly reduces mRNA accumulation. Strikingly, the number and the position of introns modulate the gene expression level in a cumulative manner. A screen for mutant strains able to express functionally an intronless allele revealed that the nuclear poly(A) binding protein Pab2 modulates intron-dependent regulation of gene expression in C. neoformans. PAB2 deletion partially restored accumulation of intronless mRNA. In addition, our results demonstrated that the essential nucleases Rrp44p and Xrn2p are implicated in the degradation of mRNA transcribed from an intronless allele in C. neoformans. Double mutant constructions and over-expression experiments suggested that Pab2p and Xrn2p could act in the same pathway whereas Rrp44p appears to act independently. Finally, deletion of the RRP6 or the CID14 gene, encoding the nuclear exosome nuclease and the TRAMP complex associated poly(A) polymerase, respectively, has no effect on intronless allele expression. PMID:23966870

  5. Multicast Services over Structured P2P Networks

    NASA Astrophysics Data System (ADS)

    Manzanares-Lopez, Pilar; Malgosa-Sanahuja, Josemaria; Muñoz-Gea, Juan Pedro; Sanchez-Aarnoutse, Juan Carlos

    IP multicast functionality was defined as an efficient method to transmit datagrams to a group of receivers. However, although a lot of research work has been done in this technology, IP multicast has not spread out over the Internet as much as expected, reducing its use for local environments (i.e., LANs). The peer-to-peer networks paradigm can be used to overcome the IP multicast limitations. In this new scenario (called Application Layer Multicast or ALM), the multicast functionality is changed from network to application layer. Although ALM solution can be classified into unstructured and structured solutions, the last ones are the best option to offer multicast services due to the effectiveness in the discovery nodes, their mathematical definition and the totally decentralized management. In this chapter we are going to offer a tutorial of the main structured ALM solutions, but introducing two novelties with respect to related surveys in the past: first, the systematic description of most representative structured ALM solution in OverSim (one of the most popular p2p simulation frameworks). Second, some simulation comparatives between flooding-based and tree-based structured ALM solution are also presented.

  6. Migration of Dust Particles from Comet 2P Encke

    NASA Technical Reports Server (NTRS)

    Ipatov, S. I.

    2003-01-01

    We investigated the migration of dust particles under the gravitational influence of all planets (except for Pluto), radiation pressure, Poynting-Robertson drag and solar wind drag for Beta equal to 0.002, 0.004, 0.01, 0.05, 0.1, 0.2, and 0.4. For silicate particles such values of Beta correspond to diameters equal to about 200, 100, 40, 9, 4, 2, and 1 microns, respectively. We used the Bulirsh-Stoer method of integration, and the relative error per integration step was taken to be less than lo-'. Initial orbits of the particles were close to the orbit of Comet 2P Encke. We considered initial particles near perihelion (runs denoted as Delta tsub o, = 0), near aphelion (Delta tsub o, = 0.5), and also studied their initial positions when the comet moved for Pa/4 after perihelion passage (such runs are denoted as Delta tsub o, =i 0.25), where Pa is the period of the comet. Variations in time T when perihelion was passed was varied with a step 0.1 day for series 'S' and with a step 1 day for series 'L'. For each Beta we considered N = 101 particles for "S" runs and 150 particles for "L" runs.

  7. Moment analysis method as applied to the 2S --> 2P transition in cryogenic alkali metal/rare gas matrices.

    PubMed

    Terrill Vosbein, Heidi A; Boatz, Jerry A; Kenney, John W

    2005-12-22

    The moment analysis method (MA) has been tested for the case of 2S --> 2P ([core]ns1 --> [core]np1) transitions of alkali metal atoms (M) doped into cryogenic rare gas (Rg) matrices using theoretically validated simulations. Theoretical/computational M/Rg system models are constructed with precisely defined parameters that closely mimic known M/Rg systems. Monte Carlo (MC) techniques are then employed to generate simulated absorption and magnetic circular dichroism (MCD) spectra of the 2S --> 2P M/Rg transition to which the MA method can be applied with the goal of seeing how effective the MA method is in re-extracting the M/Rg system parameters from these known simulated systems. The MA method is summarized in general, and an assessment is made of the use of the MA method in the rigid shift approximation typically used to evaluate M/Rg systems. The MC-MCD simulation technique is summarized, and validating evidence is presented. The simulation results and the assumptions used in applying MA to M/Rg systems are evaluated. The simulation results on Na/Ar demonstrate that the MA method does successfully re-extract the 2P spin-orbit coupling constant and Landé g-factor values initially used to build the simulations. However, assigning physical significance to the cubic and noncubic Jahn-Teller (JT) vibrational mode parameters in cryogenic M/Rg systems is not supported.

  8. Ligand field splittings in core level transitions for transition metal (TM) oxides: Tanabe-Sugano diagrams and (TM) dangling bonds in vacated O-atom defects

    NASA Astrophysics Data System (ADS)

    Lucovsky, Gerry; Wu, Kun; Pappas, Brian; Whitten, Jerry

    2013-04-01

    Defect states in the forbidden band-gap below the conduction band edge are active as electron traps in nano-grain high-) transition metal (TM) oxides with thickness >0.3 nm, e.g., ZrO2 and HfO2. These oxides have received considerable attention as gate-dielectrics in complementary metal oxide semiconductor (CMOS) devices, and more recently are emerging as candidates for charge storage and memory devices. To provide a theoretical basis for device functionality, ab-initio many-electron theory is combined with X-ray absorption spectroscopy (XAS) to study O K edge and TM core level transitions. These studies identify ligand field splittings (ΔLF) for defect state features,. When compared with those obtained from O-atom and TM-atom core spectroscopic transitions, this provides direct information about defect state sun-nm bonding arrangements. comparisons are made for (i) elemental TiO2 and Ti2O3 with different formal ionic charges, Ti4+ and Ti3+ and for (ii) Magneli Phase alloys, TinO2n-1, n is an integer 9>=n>3, and (TiO2)x(HfO2)1-x alloys. The alloys display multi-valent behavior from (i) different ionic-charge states, (ii} local bond-strain, and (iii) metallic hopping transport. The intrinsic bonding defects in TM oxides are identified as pairs of singly occupied dangling bonds. For 6-fold coordinated Ti-oxides defect excited states in 2nd derivative O K pre-edge spectra are essentially the same as single Ti-atom d2 transitions in Tanabe-Sugano (T-S) diagrams. O-vacated site defects in 8-fold coordinated ZrO2 and HfO2 are described by d8 T-S diagrams. T-S defect state ordering and splittings are functions of the coordination and symmetry of vacated site bordering TM atoms. ΔLF values from the analysis of T-S diagrams indicate medium range order (MRO) extending to 3rd and 4th nearest-neighbor (NN) TM-atoms. Values are different for 6-fold Ti, and 8-fold ZrO2 and HfO2, and scale inversely with differences in respective formal ionic radii. O-vacated site bonding

  9. Diselenophosphate-Induced Conversion of an Achiral [Cu 20 H 11 {S 2 P(O i Pr) 2 } 9 ] into a Chiral [Cu 20 H 11 {Se 2 P(O i Pr) 2 } 9 ] Polyhydrido Nanocluster

    DOE PAGES

    Dhayal, Rajendra S.; Liao, Jian-Hong; Wang, Xiaoping; Liu, Yu-Chiao; Chiang, Ming-His; Kahlal, Samia; Saillard, Jean-Yves; Liu, C. W.

    2015-11-09

    A polyhydrido copper nanocluster, [Cu20H11{Se2P(OiPr)2}9] (2H), which exhibits an intrinsically chiral inorganic core of C-3 symmetry, was synthesized from achiral [Cu20H11{S2P(OiPr)2}9] (1(H)) of C-3h symmetry by a ligand-exchange method. Likewise, the structure has a distorted cuboctahedral Cu-13 core, two triangular faces of which are capped along the C-3 axis, one by a Cu-6 cupola and the other by a single Cu atom. The Cu-20 framework is further stabilized by 9 diselenophosphate and 11 hydride ligands. The number of hydride, phosphorus, and selenium resonances and their splitting patterns in multinuclear NMR spectra of 2(H) indicate that the chiral Cu20H11 core retainsmore » its C-3 symmetry in solution. Moreover, the 11 hydride ligands were located by neutron diffraction experiments and shown to be capping (3)-H and interstitial (5)-H ligands (in square-pyramidal and trigonal-bipyramidal cavities), as supported by DFT calculations on [Cu20H11(Se2PH2)9] (2H') as a simplified model.« less

  10. Atomic parameters for the 2{p}^{5}3p\\;{}^{2}{[3/2]}_{2}-2{p}^{5}3s\\;{}^{2}{[3/2]}_{2}^{o} transition of Ne I relevant in nuclear physics

    NASA Astrophysics Data System (ADS)

    Li, Jiguang; Godefroid, Michel; Wang, Jianguo

    2016-06-01

    We calculated the magnetic dipole hyperfine interaction constants and the electric field gradients of 2{p}53p{}2{[3/2]}2 and 2{p}53s{}2[3/2{]}2o levels of Ne I by using the multiconfiguration Dirac–Hartree–Fock method. The electronic factors contributing to the isotope shifts were also estimated for the λ =614.5 {{nm}} transition connecting these two states. Electron correlation and relativistic effects including the Breit interaction were investigated in detail. Combining with recent measurements, we extracted the nuclear quadrupole moment values for 20Ne and 23Ne with a smaller uncertainty than the current available data. Isotope shifts in the 2{p}53p{}2{[3/2]}2-2{p}53s{}2[3/2{]}2o transition based on the present calculated field- and mass-shift parameters are in good agreement with the experimental values. However, the field shifts in this transition are two or three orders of magnitude smaller than the mass shifts, making rather difficult to deduce changes in nuclear-charge mean-square radii. According to our theoretical predictions, we suggest using instead transitions connecting levels arising from the 2p53s configuration to the ground state, for which the normal mass shift and specific mass shift contributions counteract each other, producing relatively small mass shifts that are only one order of magnitude larger than relatively large field shifts, especially for the 2{p}53s{}2[1/2{]}1o-2{p}6{}1{S}0 transition.

  11. Atomic parameters for the 2{p}^{5}3p\\;{}^{2}{[3/2]}_{2}-2{p}^{5}3s\\;{}^{2}{[3/2]}_{2}^{o} transition of Ne I relevant in nuclear physics

    NASA Astrophysics Data System (ADS)

    Li, Jiguang; Godefroid, Michel; Wang, Jianguo

    2016-06-01

    We calculated the magnetic dipole hyperfine interaction constants and the electric field gradients of 2{p}53p{}2{[3/2]}2 and 2{p}53s{}2[3/2{]}2o levels of Ne I by using the multiconfiguration Dirac-Hartree-Fock method. The electronic factors contributing to the isotope shifts were also estimated for the λ =614.5 {{nm}} transition connecting these two states. Electron correlation and relativistic effects including the Breit interaction were investigated in detail. Combining with recent measurements, we extracted the nuclear quadrupole moment values for 20Ne and 23Ne with a smaller uncertainty than the current available data. Isotope shifts in the 2{p}53p{}2{[3/2]}2-2{p}53s{}2[3/2{]}2o transition based on the present calculated field- and mass-shift parameters are in good agreement with the experimental values. However, the field shifts in this transition are two or three orders of magnitude smaller than the mass shifts, making rather difficult to deduce changes in nuclear-charge mean-square radii. According to our theoretical predictions, we suggest using instead transitions connecting levels arising from the 2p53s configuration to the ground state, for which the normal mass shift and specific mass shift contributions counteract each other, producing relatively small mass shifts that are only one order of magnitude larger than relatively large field shifts, especially for the 2{p}53s{}2[1/2{]}1o-2{p}6{}1{S}0 transition.

  12. 24. A CORE WORKER DISPLAYS THE CORE BOX AND CORES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. A CORE WORKER DISPLAYS THE CORE BOX AND CORES FOR A BRASS GATE VALVE BODY MADE ON A CORE BOX, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  13. CORE SATURATION BLOCKING OSCILLATOR

    DOEpatents

    Spinrad, R.J.

    1961-10-17

    A blocking oscillator which relies on core saturation regulation to control the output pulse width is described. In this arrangement an external magnetic loop is provided in which a saturable portion forms the core of a feedback transformer used with the thermionic or semi-conductor active element. A first stationary magnetic loop establishes a level of flux through the saturation portion of the loop. A second adjustable magnet moves the flux level to select a saturation point giving the desired output pulse width. (AEC)

  14. Ribosomal protein L4 is a novel regulator of the MDM2-p53 loop

    PubMed Central

    He, Xia; Li, Yuhuang; Dai, Mu-Shui; Sun, Xiao-Xin

    2016-01-01

    A number of ribosomal proteins (RPs) have been shown to play a critical role in coordinating ribosome biogenesis with cell growth and proliferation by suppressing MDM2 to induce p53 activation. While how the MDM2-p53 pathway is regulated by multiple RPs is unclear, it remains to be interesting to identify additional RPs that can regulate this pathway. Here we report that ribosomal protein L4 (RPL4) directly interacts with MDM2 at the central acidic domain and suppresses MDM2-mediated p53 ubiquitination and degradation, leading to p53 stabilization and activation. Interestingly, overexpression of RPL4 promotes the binding of MDM2 to RPL5 and RPL11 and forms a complex with RPL5, RPL11 and MDM2 in cells. Conversely, knockdown of RPL4 also induces p53 levels and p53-dependent cell cycle arrest. This p53-dependent effect requires both RPL5 and RPL11, suggesting that depletion of RPL4 triggers ribosomal stress. Together, our results reveal that balanced levels of RPL4 are critical for normal cell growth and proliferation via regulating the MDM2-p53 loop. PMID:26908445

  15. Influence of zinc deficiency on AKT-MDM2-P53 signaling axes in normal and malignant human prostate cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With prostate being the highest zinc-accumulating tissue before the onset of cancer, the effects of physiologic levels of zinc on Akt-Mdm2-p53 and Akt-p21 signaling axes in human normal prostate epithelial cells (PrEC) and malignant prostate LNCaP cells were examined. Cells were cultured for 6 d in...

  16. Notes on Operations. The Core Record: A New Bibliographic Standard.

    ERIC Educational Resources Information Center

    Cromwell, Willy

    1994-01-01

    Describes a proposed core-level bibliographic standard that combines the cost effectiveness of minimal-level cataloging with full-level cataloging's utility for library cooperation. The process of developing core-level standards, a definition of a core record, comparisons of core records with minimal- and full-level records, and implementation…

  17. Modulation of K2P2.1 and K2P10.1 K+ channel sensitivity to carvedilol by alternative mRNA translation initiation

    PubMed Central

    Kisselbach, J; Seyler, C; Schweizer, P A; Gerstberger, R; Becker, R; Katus, H A; Thomas, D

    2014-01-01

    Background and Purpose The β-receptor antagonist carvedilol blocks a range of ion channels. K2P2.1 (TREK1) and K2P10.1 (TREK2) channels are expressed in the heart and regulated by alternative translation initiation (ATI) of their mRNA, producing functionally distinct channel variants. The first objective was to investigate acute effects of carvedilol on human K2P2.1 and K2P10.1 channels. Second, we sought to study ATI-dependent modulation of K2P K+ current sensitivity to carvedilol. Experimental Approach Using standard electrophysiological techniques, we recorded currents from wild-type and mutant K2P2.1 and K2P10.1 channels in Xenopus oocytes and HEK 293 cells. Key Results Carvedilol concentration-dependently inhibited K2P2.1 channels (IC50,oocytes = 20.3 μM; IC50,HEK = 1.6 μM) and this inhibition was frequency-independent. When K2P2.1 isoforms generated by ATI were studied separately in oocytes, the IC50 value for carvedilol inhibition of full-length channels (16.5 μM) was almost 5-fold less than that for the truncated channel variant (IC50 = 79.0 μM). Similarly, the related K2P10.1 channels were blocked by carvedilol (IC50,oocytes = 24.0 μM; IC50,HEK = 7.6 μM) and subject to ATI-dependent modulation of drug sensitivity. Conclusions and Implications Carvedilol targets K2P2.1 and K2P10.1 K+ channels. This previously unrecognized mechanism supports a general role of cardiac K2P channels as antiarrhythmic drug targets. Furthermore, the work reveals that the sensitivity of the cardiac ion channels K2P2.1 and K2P10.1 to block was modulated by alternative mRNA translation initiation. PMID:25168769

  18. Isotopic and hydrologic responses of small, closed lakes to climate variability: Comparison of measured and modeled lake level and sediment core oxygen isotope records

    NASA Astrophysics Data System (ADS)

    Steinman, Byron A.; Abbott, Mark B.; Nelson, Daniel B.; Stansell, Nathan D.; Finney, Bruce P.; Bain, Daniel J.; Rosenmeier, Michael F.

    2013-03-01

    Simulations conducted using a coupled lake-catchment isotope mass balance model forced with continuous precipitation, temperature, and relative humidity data successfully reproduce (within uncertainty limits) long-term (i.e., multidecadal) trends in reconstructed lake surface elevations and sediment core oxygen isotope (δ18O) values at Castor Lake and Scanlon Lake, north-central Washington. Error inherent in sediment core dating methods and uncertainty in climate data contribute to differences in model reconstructed and measured short-term (i.e., sub-decadal) sediment (i.e., endogenic and/or biogenic carbonate) δ18O values, suggesting that model isotopic performance over sub-decadal time periods cannot be successfully investigated without better constrained climate data and sediment core chronologies. Model reconstructions of past lake surface elevations are consistent with estimates obtained from aerial photography. Simulation results suggest that precipitation is the strongest control on lake isotopic and hydrologic dynamics, with secondary influence by temperature and relative humidity. This model validation exercise demonstrates that lake-catchment oxygen isotope mass balance models forced with instrumental climate data can reproduce lake hydrologic and isotopic variability over multidecadal (or longer) timescales, and therefore, that such models could potentially be used for quantitative investigations of paleo-lake responses to hydroclimatic change.

  19. Core layering

    NASA Astrophysics Data System (ADS)

    Jacobson, S. A.; Rubie, D. C.; Hernlund, J. W.; Morbidelli, A.

    2015-12-01

    We have created a planetary accretion and differentiation model that self-consistently builds and evolves Earth's core. From this model, we show that the core grows stably stratified as the result of rising metal-silicate equilibration temperatures and pressures, which increases the concentrations of light element impurities into each newer core addition. This stable stratification would naturally resist convection and frustrate the onset of a geodynamo, however, late giant impacts could mechanically mix the distinct accreted core layers creating large homogenous regions. Within these regions, a geodynamo may operate. From this model, we interpret the difference between the planetary magnetic fields of Earth and Venus as a difference in giant impact histories. Our planetary accretion model is a numerical N-body integration of the Grand Tack scenario [1]—the most successful terrestrial planet formation model to date [2,3]. Then, we take the accretion histories of Earth-like and Venus-like planets from this model and post-process the growth of each terrestrial planet according to a well-tested planetary differentiation model [4,5]. This model fits Earth's mantle by modifying the oxygen content of the pre-cursor planetesimals and embryos as well as the conditions of metal-silicate equilibration. Other non-volatile major, minor and trace elements included in the model are assumed to be in CI chondrite proportions. The results from this model across many simulated terrestrial planet growth histories are robust. If the kinetic energy delivered by larger impacts is neglected, the core of each planet grows with a strong stable stratification that would significantly impede convection. However, if giant impact mixing is very efficient or if the impact history delivers large impacts late, than the stable stratification can be removed. [1] Walsh et al. Nature 475 (2011) [2] O'Brien et al. Icarus 223 (2014) [3] Jacobson & Morbidelli PTRSA 372 (2014) [4] Rubie et al. EPSL 301

  20. The splitting and oscillator strengths for the 2S/2/S-2p/2/P/0/ doublet in lithium-like sulfur. [during Skylab observed solar flares

    NASA Technical Reports Server (NTRS)

    Pegg, D. J.; Forester, J. P.; Elston, S. B.; Griffin, P. M.; Peterson, R. S.; Thoe, R. S.; Vane, C. R.; Sellin, I. A.; Groeneveld, K.-O.

    1977-01-01

    The beam-foil technique has been used to study the 2S(2)S-2p(2)P(0) doublet in S XIV. The results confirm the doublet splitting measured aboard Skylab during solar flare events. In addition, the oscillator strengths for the resonance transitions comprising this doublet have been measured and found to agree well with recent relativistic f-value calculations.

  1. Casein kinase II is required for the spindle assembly checkpoint by regulating Mad2p in fission yeast

    SciTech Connect

    Shimada, Midori; Yamamoto, Ayumu; Murakami-Tonami, Yuko; Nakanishi, Makoto; Yoshida, Takashi; Aiba, Hirofumi; Murakami, Hiroshi

    2009-10-23

    The spindle checkpoint is a surveillance mechanism that ensures the fidelity of chromosome segregation in mitosis. Here we show that fission yeast casein kinase II (CK2) is required for this checkpoint function. In the CK2 mutants mitosis occurs in the presence of a spindle defect, and the spindle checkpoint protein Mad2p fails to localize to unattached kinetochores. The CK2 mutants are sensitive to the microtubule depolymerising drug thiabendazole, which is counteracted by ectopic expression of mad2{sup +}. The level of Mad2p is low in the CK2 mutants. These results suggest that CK2 has a role in the spindle checkpoint by regulating Mad2p.

  2. TIDI Neutral Winds From O2 P Branch Broadband Filter

    NASA Astrophysics Data System (ADS)

    Wu, Q.; Killeen, T.; Gablehouse, R.; Johnson, R.; Solomon, S.; Skinner, W.; Niciejewski, R.; Ortland, D.; Gell, D.

    A new operational mode for the instrument has been designed to incorporate a broadband filter, which allows most of the O2 (0-0) P branch to pass through. The broadband filter data increases the signal level by an order of magnitude, which greatly increases the accuracy of the neutral wind allowing more detailed analysis of the migrating and non-migrating tide in the MLT region. Already the new wind data have shown strong non-migrating tide component. Comparisons with ground-based radar measurements show a much better consistency. We will report these new data and tidal analysis results

  3. Hepatitis B core-related antigen (HBcrAg) levels in the natural history of hepatitis B virus infection in a large European cohort predominantly infected with genotypes A and D.

    PubMed

    Maasoumy, B; Wiegand, S B; Jaroszewicz, J; Bremer, B; Lehmann, P; Deterding, K; Taranta, A; Manns, M P; Wedemeyer, H; Glebe, D; Cornberg, M

    2015-06-01

    Hepatitis B core-related antigen (HBcrAg) has been suggested as an additional marker of hepatitis B virus (HBV) infection. HBcrAg combines the antigenic reactivity resulting from denatured hepatitis B e antigen (HBeAg), HBV core antigen and an artificial core-related protein (p22cr). In Asian patients, high levels of HBcrAg have been suggested to be an independent risk factor for hepatocellular carcinoma, while low levels could guide safe cessation of treatment with nucleos(t)ide analogues. We here studied HBcrAg levels in different phases of HBV infection in a large European cohort predominantly infected with genotypes A and D: HBeAg-positive immune tolerance (n = 30), HBeAg-positive immune clearance (IC) (n = 60), HBeAg-negative hepatitis (ENH) (n = 50), HBeAg-negative inactive/quiescent carrier phase (c) (n = 109) and acute hepatitis B (n = 8). Median HBcrAg levels were high in the immune tolerance and immune clearance phases (8.41 and 8.11 log U/mL, respectively), lower in ENH subjects (4.82 log U/mL) but only 2.00 log U/mL in ENQ subjects. Correlation between HBcrAg and HBV DNA varied among the different phases of HBV infection, while HBcrAg moderately correlated with hepatitis B surface antigen in all phases. ENQ patients had HBcrAg levels <3 log U/mL in 79%, in contrast to only 12% in the ENH group. HBcrAg levels vary significantly during the different phases of HBV infection. HBcrAg may serve as valuable marker for virus replication and reflect the transcriptional activity of intrahepatic cccDNA. In HBeAg-negative patients, HBcrAg may help to distinguish between inactive carriers (ENQ) and those with active disease (ENH).

  4. Induction of intranuclear membranes by overproduction of Opi1p and Scs2p, regulators for yeast phospholipid biosynthesis, suggests a mechanism for Opi1p nuclear translocation.

    PubMed

    Masuda, Miki; Oshima, Ayaka; Noguchi, Tetsuko; Kagiwada, Satoshi

    2016-03-01

    In the yeast Saccharomyces cerevisiae, the expression of phospholipid biosynthetic genes is suppressed by the Opi1p negative regulator. Opi1p enters into the nucleoplasm from the nuclear membrane to suppress the gene expression under repressing conditions. The binding of Opi1p to the nuclear membrane requires an integral membrane protein, Scs2p and phosphatidic acid (PA). Although it is demonstrated that the association of Opi1p with membranes is affected by PA levels, how Opi1p dissociates from Scs2p is unknown. Here, we found that fluorescently labelled Opi1p accumulated on a perinuclear region in an Scs2p-dependent manner. Electron microscopic analyses indicated that the perinuclear region consists of intranuclear membranes, which may be formed by the invagination of the nuclear membrane due to the accumulation of Opi1p and Scs2p in a restricted area. As expected, localization of Opi1p and Scs2p in the intranuclear membranes was detected by immunoelectron microscopy. Biochemical analysis showed that Opi1p recovered in the membrane fraction was detergent insoluble while Scs2p was soluble, implying that Opi1p behaves differently from Scs2p in the fraction. We hypothesize that Opi1p dissociates from Scs2p after targeting to the nuclear membrane, making it possible to be released from the membrane quickly when PA levels decrease. PMID:26590299

  5. Core-Noise Research

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2012-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015 (N+1), 2020 (N+2), and 2025 (N+3) timeframes; SFW strategic thrusts and technical challenges; SFW advanced subsystems that are broadly applicable to N+3 vehicle concepts, with an indication where further noise research is needed; the components of core noise (compressor, combustor and turbine noise) and a rationale for NASA's current emphasis on the combustor-noise component; the increase in the relative importance of core noise due to turbofan design trends; the need to understand and mitigate core-noise sources for high-efficiency small gas generators; and the current research activities in the core-noise area, with additional details given about forthcoming updates to NASA's Aircraft Noise Prediction Program (ANOPP) core-noise prediction capabilities, two NRA efforts (Honeywell International, Phoenix, AZ and University of Illinois at Urbana-Champaign, respectively) to improve the understanding of core-noise sources and noise propagation through the engine core, and an effort to develop oxide/oxide ceramic-matrix-composite (CMC) liners for broadband noise attenuation suitable for turbofan-core application. Core noise must be addressed to ensure that the N+3 noise goals are met. Focused, but long-term, core-noise research is carried out to enable the advanced high-efficiency small gas-generator subsystem, common to several N+3 conceptual designs, needed to meet NASA's technical challenges. Intermediate updates to prediction tools are implemented as the understanding of the source structure and engine-internal propagation effects is improved. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The

  6. Numerical nonlinear inelastic analysis of stiffened shells of revolution. Volume 3: Engineer's program manual for STARS-2P digital computer program

    NASA Technical Reports Server (NTRS)

    Svalbonas, V.; Levine, H.; Ogilvie, P.

    1975-01-01

    Engineering programming information is presented for the STARS-2P (shell theory automated for rotational structures-2P (plasticity)) digital computer program, and FORTRAN 4 was used in writing the various subroutines. The execution of this program requires the use of thirteen temporary storage units. The program was initially written and debugged on the IBM 370-165 computer and converted to the UNIVAC 1108 computer, where it utilizes approximately 60,000 words of core. Only basic FORTRAN library routines are required by the program: sine, cosine, absolute value, and square root.

  7. Angle-resolved study of Ar 2p{sub 1/2,3/2}{sup -1} ns,d resonant Auger decay

    SciTech Connect

    Farhat, A.; Humphrey, M.; Langer, B.

    1997-04-01

    The Auger decay of core excited states in rare gases has been subject to rather intense investigation over a number of years due to its complex nature. The authors have measured the intensity distributions and angular distributions ({beta} parameters) for the Auger decay spectra following each of the 2p{sub 1/2,3/2} {r_arrow} 4s, 3d, 4d resonant excitations in argon. This report presents their result only for the angular distributions ({beta} parameters) of the 2p{sub 1/2}{sup {minus}1}4s resonance.

  8. New superhindered polydentate polyphosphine ligands P(CH2CH2P(t)Bu2)3, PhP(CH2CH2P(t)Bu2)2, P(CH2CH2CH2P(t)Bu2)3, and their ruthenium(II) chloride complexes.

    PubMed

    Gilbert-Wilson, Ryan; Field, Leslie D; Bhadbhade, Mohan M

    2012-03-01

    The synthesis and characterization of the extremely hindered phosphine ligands, P(CH(2)CH(2)P(t)Bu(2))(3) (P(2)P(3)(tBu), 1), PhP(CH(2)CH(2)P(t)Bu(2))(2) (PhP(2)P(2)(tBu), 2), and P(CH(2)CH(2)CH(2)P(t)Bu(2))(3) (P(3)P(3)(tBu), 3) are reported, along with the synthesis and characterization of ruthenium chloro complexes RuCl(2)(P(2)P(3)(tBu)) (4), RuCl(2)(PhP(2)P(2)(tBu)) (5), and RuCl(2)(P(3)P(3)(tBu)) (6). The bulky P(2)P(3)(tBu) (1) and P(3)P(3)(tBu) (3) ligands are the most sterically encumbered PP(3)-type ligands so far synthesized, and in all cases, only three phosphorus donors are able to bind to the metal center. Complexes RuCl(2)(PhP(2)P(2)(tBu)) (5) and RuCl(2)(P(3)P(3)(tBu)) (6) were characterized by crystallography. Low temperature solution and solid state (31)P{(1)H} NMR were used to demonstrate that the structure of RuCl(2)(P(2)P(3)(tBu)) (4) is probably analogous to that of RuCl(2)(PhP(2)P(2)(tBu)) (5) which had been structurally characterized.

  9. Sea-level and provenance controlled clay mineral assemblage since the last 19 ka in the southern South China Sea: records of Core MD05-2894 off the Sunda Shelf

    NASA Astrophysics Data System (ADS)

    Wang, H.; Liu, Z.; Colin, C.; Sathiamurthy, E.; Hantoro, W. S.; Zhao, Y.

    2010-12-01

    High-resolution clay mineral assemblage at Core MD05-2894 (7°2.25'N, 111°33.11'E, water depth 1982 m) in the southern South China Sea is used to investigate the provenance and transport process of fine-grained sediments since the last 19 ka. In order to perform the source analysis, clay minerals in surface sediments of various potential source areas are also analyzed, including the Mekong River, Malay Peninsula, Sumatra, Borneo, and the Sunda Shelf. Clay mineralogical results at Core MD05-2894 indicate the sea level rise as the principal factor to drive provenance changes. During the late glacial stage, the Sunda Shelf was exposed. High values of smectite (average 32%) and kaolinite (27%) at the core suggest a large contribution of fine-grained sediments transported by the potential Sunda paleo-drainage system from Malaysia Peninsula and Sumatra, where kaolinite and smectite are rich. During the deglaciation when the sea level rises, illite and chlorite contents increased with a similar pattern, whereas kaolinite and smectite contents decreased, suggesting more sediment contribution from the Mekong River and Northwest Borneo. During the Holocene, variations in four clay mineral contents keep relatively stable with more illite and chlorite contents than those of the deglaciation and last glacial stage, indicating a mixture of various provenances.

  10. Classical trajectory study of alignment effects in the capture process: He 2+-Li ∗(2pΣ,2pΠ) collisions

    NASA Astrophysics Data System (ADS)

    Perumal, A. N.; Tripathi, D. N.

    1998-08-01

    A simulation method (CTMC) has been used to investigate the selectivity and alignment effects on the capture process in He 2+-Li ∗(2pΣ,2pΠ) collisions. The anomalous results of the experiment (∼ 50% error) as well as the AO calculation of Gieler et al. in case of capture into He II ( n = 4) from the initial Li ∗ (2pΣ) state are not found in the present work. Relative velocity and spatial overlap together mainly control the capture process in ion-atom collisions. The n-distribution of the final capture state is also presented.

  11. Evolutionary divergence of Ure2pA glutathione transferases in wood degrading fungi.

    PubMed

    Roret, Thomas; Thuillier, Anne; Favier, Frédérique; Gelhaye, Eric; Didierjean, Claude; Morel-Rouhier, Mélanie

    2015-10-01

    The intracellular systems of detoxification are crucial for the survival of wood degrading fungi. Within these systems, glutathione transferases could play a major role since this family of enzymes is specifically extended in lignolytic fungi. In particular the Ure2p class represents one third of the total GST number in Phanerochaete chrysosporium. These proteins have been phylogenetically split into two subclasses called Ure2pA and Ure2pB. Ure2pB can be classified as Nu GSTs because of shared structural and functional features with previously characterized bacterial isoforms. Ure2pA can rather be qualified as Nu-like GSTs since they exhibit a number of differences. Ure2pA possess a classical transferase activity, a more divergent catalytic site and a higher structural flexibility for some of them, compared to Nu GSTs. The characterization of four members of this Ure2pA subclass (PcUre2pA4, PcUre2pA5, PcUre2pA6 and PcUre2pA8) revealed specific functional and structural features, suggesting that these enzymes have rapidly evolved and differentiated, probably to adapt to the complex chemical environment associated with wood decomposition.

  12. Identifying candidate genes for 2p15p16.1 microdeletion syndrome using clinical, genomic, and functional analysis

    PubMed Central

    Bagheri, Hani; Badduke, Chansonette; Qiao, Ying; Colnaghi, Rita; Abramowicz, Iga; Alcantara, Diana; Dunham, Christopher; Wen, Jiadi; Wildin, Robert S.; Nowaczyk, Malgorzata J.M.; Eichmeyer, Jennifer; Lehman, Anna; Maranda, Bruno; Martell, Sally; Shan, Xianghong; Lewis, Suzanne M.E.; O’Driscoll, Mark; Gregory-Evans, Cheryl Y.

    2016-01-01

    The 2p15p16.1 microdeletion syndrome has a core phenotype consisting of intellectual disability, microcephaly, hypotonia, delayed growth, common craniofacial features, and digital anomalies. So far, more than 20 cases of 2p15p16.1 microdeletion syndrome have been reported in the literature; however, the size of the deletions and their breakpoints vary, making it difficult to identify the candidate genes. Recent reports pointed to 4 genes (XPO1, USP34, BCL11A, and REL) that were included, alone or in combination, in the smallest deletions causing the syndrome. Here, we describe 8 new patients with the 2p15p16.1 deletion and review all published cases to date. We demonstrate functional deficits for the above 4 candidate genes using patients’ lymphoblast cell lines (LCLs) and knockdown of their orthologs in zebrafish. All genes were dosage sensitive on the basis of reduced protein expression in LCLs. In addition, deletion of XPO1, a nuclear exporter, cosegregated with nuclear accumulation of one of its cargo molecules (rpS5) in patients’ LCLs. Other pathways associated with these genes (e.g., NF-κB and Wnt signaling as well as the DNA damage response) were not impaired in patients’ LCLs. Knockdown of xpo1a, rel, bcl11aa, and bcl11ab resulted in abnormal zebrafish embryonic development including microcephaly, dysmorphic body, hindered growth, and small fins as well as structural brain abnormalities. Our multifaceted analysis strongly implicates XPO1, REL, and BCL11A as candidate genes for 2p15p16.1 microdeletion syndrome. PMID:27699255

  13. Identifying candidate genes for 2p15p16.1 microdeletion syndrome using clinical, genomic, and functional analysis

    PubMed Central

    Bagheri, Hani; Badduke, Chansonette; Qiao, Ying; Colnaghi, Rita; Abramowicz, Iga; Alcantara, Diana; Dunham, Christopher; Wen, Jiadi; Wildin, Robert S.; Nowaczyk, Malgorzata J.M.; Eichmeyer, Jennifer; Lehman, Anna; Maranda, Bruno; Martell, Sally; Shan, Xianghong; Lewis, Suzanne M.E.; O’Driscoll, Mark; Gregory-Evans, Cheryl Y.

    2016-01-01

    The 2p15p16.1 microdeletion syndrome has a core phenotype consisting of intellectual disability, microcephaly, hypotonia, delayed growth, common craniofacial features, and digital anomalies. So far, more than 20 cases of 2p15p16.1 microdeletion syndrome have been reported in the literature; however, the size of the deletions and their breakpoints vary, making it difficult to identify the candidate genes. Recent reports pointed to 4 genes (XPO1, USP34, BCL11A, and REL) that were included, alone or in combination, in the smallest deletions causing the syndrome. Here, we describe 8 new patients with the 2p15p16.1 deletion and review all published cases to date. We demonstrate functional deficits for the above 4 candidate genes using patients’ lymphoblast cell lines (LCLs) and knockdown of their orthologs in zebrafish. All genes were dosage sensitive on the basis of reduced protein expression in LCLs. In addition, deletion of XPO1, a nuclear exporter, cosegregated with nuclear accumulation of one of its cargo molecules (rpS5) in patients’ LCLs. Other pathways associated with these genes (e.g., NF-κB and Wnt signaling as well as the DNA damage response) were not impaired in patients’ LCLs. Knockdown of xpo1a, rel, bcl11aa, and bcl11ab resulted in abnormal zebrafish embryonic development including microcephaly, dysmorphic body, hindered growth, and small fins as well as structural brain abnormalities. Our multifaceted analysis strongly implicates XPO1, REL, and BCL11A as candidate genes for 2p15p16.1 microdeletion syndrome.

  14. The Common Core Takes Hold

    ERIC Educational Resources Information Center

    Rothman, Robert

    2014-01-01

    A survey administered in the spring of 2013 by the Center on Education Policy (CEP) inquired into the implementation of Common Core State Standards at that time. Based on self-reports by state officials, the survey found that curricula aligned to the common core were already being taught in at least some districts or grade levels. All states…

  15. Core-Noise

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2010-01-01

    This presentation is a technical progress report and near-term outlook for NASA-internal and NASA-sponsored external work on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system level noise metrics for the 2015, 2020, and 2025 timeframes; the emerging importance of core noise and its relevance to the SFW Reduced-Noise-Aircraft Technical Challenge; the current research activities in the core-noise area, with some additional details given about the development of a high-fidelity combustion-noise prediction capability; the need for a core-noise diagnostic capability to generate benchmark data for validation of both high-fidelity work and improved models, as well as testing of future noise-reduction technologies; relevant existing core-noise tests using real engines and auxiliary power units; and examples of possible scenarios for a future diagnostic facility. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Noise-Aircraft Technical Challenge aims to enable concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical for enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor designs could increase

  16. Amplification of 2p as a Genomic Marker for Transformation in Lymphoma

    PubMed Central

    Kwiecinska, Anna; Ichimura, Koichi; Berglund, Mattias; Dinets, Andrii; Sulaiman, Luqman; Collins, V Peter; Larsson, Catharina; Porwit, Anna; Lagercrantz, Svetlana Bajalica

    2014-01-01

    To outline further genetic mechanisms of transformation from follicular lymphoma (FL) to diffuse large B-cell lymphoma (DLBCL), we have performed whole genome array-CGH in 81 tumors from 60 patients [29 de novo DLBCL (dnDLBCL), 31 transformed DLBCL (tDLBCL), and 21 antecedent FL]. In 15 patients, paired tumor samples (primary FL and a subsequent tDLBCL) were available, among which three possessed more than two subsequent tumors, allowing us to follow specific genetic alterations acquired before, during, and after the transformation. Gain of 2p15–16.1 encompassing, among others, the REL, BCL11A, USP34, COMMD1, and OTX1 genes was found to be more common in the tDLBCL compared with dnDLBCL (P < 0.001). Furthermore, a high-level amplification of 2p15–16.1 was also detected in the FL stage prior to transformation, indicating its importance during the transformation event. Quantitative real-time PCR showed a higher level of amplification of REL, USP34, and COMMD1 (all involved in the NFκΒ-pathway) compared with BCL11A, which indicates that the altered genes disrupting the NFκΒ pathway may be the driver genes of transformation rather than the previously suggested BCL11A. Moreover, a 17q21.33 amplification was exclusively found in tDLBCL, never in FL (P < 0.04) or dnDLBCL, indicating an upregulation of genes of importance during the later phase of transformation. Taken together, our study demonstrates potential genomic markers for disease progression to clinically more aggressive forms. We also confirm the importance of the TP53-, CDKN2A-, and NFκΒ-pathways for the transformation from FL to DLBCL. © 2014 Wiley Periodicals, Inc. PMID:24832791

  17. Core Noise Reduction

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduce-Perceived-Noise Technical Challenge; and the current research activities in the core noise area. Recent work1 on the turbine-transmission loss of combustor noise is briefly described, two2,3 new NRA efforts in the core-noise area are outlined, and an effort to develop CMC-based acoustic liners for broadband noise reduction suitable for turbofan-core application is delineated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. The Subsonic Fixed Wing Project's Reduce-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries.

  18. Control of sigma virus multiplication by the ref(2)P gene of Drosophila melanogaster: an in vivo study of the PB1 domain of Ref(2)P.

    PubMed

    Carré-Mlouka, A; Gaumer, S; Gay, P; Petitjean, A M; Coulondre, C; Dru, P; Bras, F; Dezélée, S; Contamine, D

    2007-05-01

    Ref(2)P has been described as one of the Drosophila proteins that interacts with the sigma virus cycle. We generated alleles to identify critical residues involved in the restrictive (inhibiting viral multiplication) or permissive (allowing viral multiplication) character of Ref(2)P. We demonstrate that permissive alleles increase the ability of the sigma virus to infect Drosophila when compared to null alleles and we confirm that restrictive alleles decrease this capacity. Moreover, we have created alleles unfunctional in viral cycling while functional for Ref(2)P fly functions. This type of allele had never been observed before and shows that fly- and virus-related activities of Ref(2)P are separable. The viral status of Ref(2)P variants is determined by the amino-terminal PB1 domain polymorphism. In addition, an isolated PB1 domain mimics virus-related functions even if it is similar to a loss of function toward fly-related activities. The evolutionary tree of the Ref(2)P PB1 domain that we could build on the basis of the natural allele sequences is in agreement with an evolution of PB1 domain due to successive transient selection waves.

  19. Mercury's Core

    NASA Astrophysics Data System (ADS)

    Peale, S. J.

    2005-05-01

    In determining Mercury's core structure from its rotational properties, the location of Cassini state 1 is crucial. Convincing radar evidence indicates that the mantle rests on a liquid layer (Margot et al. 2005), but there are no empirical constraints on the moment of inertia C/MR2, which constraints must wait for the determination of the gravitational coefficients J2 and C22 from the MESSENGER orbiting spacecraft, and an accurate determination of the obliquity of the Cassini state. Tidal and core-mantle dissipation drive the spin to the Cassini state with a time scale O(105) years, so the spin should occupy the Cassini state and thereby define its obliquity---unless there has been a recent excitation of a free precession of the spin. Another way the spin might be displaced from the Cassini state is if the variations in the orbital elements, which change the position of the Cassini state, cause the spin axis to lag behind as it attempts to follow the state. Fortunately, the solid angle the spin axis encloses as it precesses around the Cassini state is an adiabatic invariant, and it is conserved if the orbital element variations are slow compared to the precession rate. As the precession period is O(1000) years, and the time scales of orbital parameter variations are O(105) years, the spin axis should remain very close to the Cassini state if it were ever close. But how close is close? The increasing precision of the radar and eventual spacecraft measurements warrants a check on the likely proximity of the spin axis to the Cassini state. By numerically following the positions of the spin axis and Cassini state with orbital parameters varying with time scales and amplitudes comparable to the real variations, we show that the spin should remain within 1″ of the Cassini state once dissipative torques bring it there. The current spin axis position should thus define the Cassini state sufficiently to put reasonably tight constraints on the core structure

  20. Core Noise - Increasing Importance

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduced-Perceived-Noise Technical Challenge; and the current research activities in the core-noise area, with additional details given about the development of a high-fidelity combustor-noise prediction capability as well as activities supporting the development of improved reduced-order, physics-based models for combustor-noise prediction. The need for benchmark data for validation of high-fidelity and modeling work and the value of a potential future diagnostic facility for testing of core-noise-reduction concepts are indicated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor

  1. In vivo imaging of Ca2+, pH, and reactive oxygen species using fluorescent probes in plants.

    PubMed

    Swanson, Sarah J; Choi, Won-Gyu; Chanoca, Alexandra; Gilroy, Simon

    2011-01-01

    Changes in the levels of Ca(2+), pH, and reactive oxygen species (ROS) are recognized as key cellular regulators involved in diverse physiological and developmental processes in plants. Critical to understanding how they exert such widespread control is an appreciation of their spatial and temporal dynamics at levels from organ to organelle and from seconds to many hours. With appropriate controls, fluorescent sensors can provide a robust approach with which to quantify such changes in Ca(2+), pH, and ROS in real time, in vivo. The fluorescent cellular probes available for visualization split into two broad classes: (a) dyes and (b) an increasingly diverse set of genetically encoded sensors based around green fluorescent proteins (GFPs). The GFP probes in particular can be targeted to well-defined subcellular locales, offering the possibility of high-resolution mapping of these signals within the cell.

  2. Hepatitis B Virus Core Promoter Double Mutations (A1762T, G1764A) Are Associated with Lower Levels of Serum Dihydrolipoyl Dehydrogenase

    PubMed Central

    Jiang, Zhi-Hua; Chen, Qin-Yan; Harrison, Tim J.; Li, Guo-Jian; Wang, Xue-Yan; Li, Hai; Hu, Li-Ping; Li, Kai-Wen; Yang, Qing-Li; Tan, Chao; Fang, Zhong-Liao

    2016-01-01

    Objectives The aim of this study was to identify serum proteins with differential concentrations between hepatocellular carcinoma (HCC) patients and HBsAg asymptomatic carriers among individuals infected with hepatitis B virus (HBV) with basal core promoter (BCP) double mutations (A1762T, G1764A). Methods iTRAQ and liquid chromatography-tandem mass spectrometry were used to identify differentially expressed protein, and an ELISA test was used for the validation test. Results The total number of proteins identified was 1,125, of which 239 showed statistically significant differences in their expression. The relative concentrations of serum dihydrolipoyl dehydrogenase (DLD), which showed the most significant correlation with liver diseases and infection, were significantly lower in HCC patients than asymptomatic HBsAg carriers and individuals negative for HBsAg. However, only the difference between HCC patients with BCP double mutations and HBsAg-negative individuals could be confirmed by ELISA. Meanwhile, we found that the concentrations of serum DLD in those infected with HBV with BCP double mutations were significantly lower than in individuals with the wild-type BCP. However, the difference in the concentrations of serum DLD between individuals with wild-type BCP and those negative for HBsAg was not significant. Conclusions HBV with BCP double mutations are associated with lower concentrations of serum DLD. PMID:27303803

  3. Influence of growth conditions on RNA levels in relation to activity of core metabolic enzymes in the parasitic protists Trypanosoma brucei and Trichomonas vaginalis.

    PubMed

    ter Kuile, B H; Bonilla, Y

    1999-03-01

    Levels of mRNAs encoding metabolic enzymes and their cellular activities were measured on continuous culture samples of the parasitic protists Trypanosoma brucei and Trichomonas vaginalis. The organisms were grown in chemostats at varying growth rates under glucose limitation or in the presence of excess glucose (EG), resulting in extensive adaptation of the cellular activities of glycolytic enzymes. rRNA and mRNA for beta-tubulin were monitored as controls. In Trypanosoma brucei levels of all RNAs showed a biphasic dependence on growth rate (= dilution rate D), with a sharp increase at higher D values. Cellular RNA levels of Trichomonas vaginalis rate-limited by glucose decreased slightly with increasing D. In EG-grown cells the opposite trend was observed. Equal levels for both carbon regimes were observed at intermediate D values. In both species the ratio between rRNA and mRNA encoding beta-tubulin was constant, independent of the carbon regime. mRNA encoding metabolic enzymes showed varying degrees of correlation with rRNA and beta-tubulin mRNA. In contrast, there was little to no correlation between mRNA levels and the activities of the enzymes they encode, even though only one of these is allosterically regulated. The data indicate that RNA levels in Trypanosoma brucei and Trichomonas vaginalis are determined by growth rate and in the latter species by the availability of the carbon and energy source. Rates of synthesis of metabolic enzymes are most likely regulated at the post-transcriptional level.

  4. The excitation and collisional deactivation of metastable N/2P/ atoms in auroras

    NASA Technical Reports Server (NTRS)

    Zipf, E. C.; Espy, P. J.; Boyle, C. F.

    1980-01-01

    The concentration and altitude distribution of metastable N(2P) atoms was measured in a diffuse IBC II(+) auroral arc. The dominant N(2P) source is shown to be the dissociative excitation of N2 by electron impact with a minor contribution from the dissociative recombination of N2(+) ions. The possibility that an ion-molecule process involving atomic oxygen and vibrationally excited N2(+) ions is a significant N(2P) source is examined. Values for the proportional yield of N(+), N(2P), N(2D), and N(4S) atoms from electron-impact dissociation of N2 under optically thick conditions are given.

  5. Therapeutic targeting of two-pore-domain potassium (K(2P)) channels in the cardiovascular system.

    PubMed

    Wiedmann, Felix; Schmidt, Constanze; Lugenbiel, Patrick; Staudacher, Ingo; Rahm, Ann-Kathrin; Seyler, Claudia; Schweizer, Patrick A; Katus, Hugo A; Thomas, Dierk

    2016-05-01

    The improvement of treatment strategies in cardiovascular medicine is an ongoing process that requires constant optimization. The ability of a therapeutic intervention to prevent cardiovascular pathology largely depends on its capacity to suppress the underlying mechanisms. Attenuation or reversal of disease-specific pathways has emerged as a promising paradigm, providing a mechanistic rationale for patient-tailored therapy. Two-pore-domain K(+) (K(2P)) channels conduct outward K(+) currents that stabilize the resting membrane potential and facilitate action potential repolarization. K(2P) expression in the cardiovascular system and polymodal K2P current regulation suggest functional significance and potential therapeutic roles of the channels. Recent work has focused primarily on K(2P)1.1 [tandem of pore domains in a weak inwardly rectifying K(+) channel (TWIK)-1], K(2P)2.1 [TWIK-related K(+) channel (TREK)-1], and K(2P)3.1 [TWIK-related acid-sensitive K(+) channel (TASK)-1] channels and their role in heart and vessels. K(2P) currents have been implicated in atrial and ventricular arrhythmogenesis and in setting the vascular tone. Furthermore, the association of genetic alterations in K(2P)3.1 channels with atrial fibrillation, cardiac conduction disorders and pulmonary arterial hypertension demonstrates the relevance of the channels in cardiovascular disease. The function, regulation and clinical significance of cardiovascular K(2P) channels are summarized in the present review, and therapeutic options are emphasized.

  6. Pex19p contributes to peroxisome inheritance in the association of peroxisomes to Myo2p.

    PubMed

    Otzen, Marleen; Rucktäschel, Robert; Thoms, Sven; Emmrich, Kerstin; Krikken, Arjen M; Erdmann, Ralf; van der Klei, Ida J

    2012-07-01

    During budding of yeast cells peroxisomes are distributed over mother cell and bud, a process that involves the myosin motor protein Myo2p and the peroxisomal membrane protein Inp2p. Here, we show that Pex19p, a peroxin implicated in targeting and complex formation of peroxisomal membrane proteins, also plays a role in peroxisome partitioning. Binding studies revealed that Pex19p interacts with the cargo-binding domain of Myo2p. We identified mutations in Myo2p that specifically reduced binding to Pex19p, but not to Inp2p. The interaction between Myo2p and Pex19p was also reduced by a mutation that blocked Pex19p farnesylation. Microscopy revealed that the Pex19p-Myo2p interaction is important for peroxisome inheritance, because mutations that affect this interaction hamper peroxisome inheritance in vivo. Together these data suggest that both Inp2p and Pex19p are required for proper association of peroxisomes to Myo2p.

  7. Simulation of Mini-Magnetospheric Plasma Propulsion (M2P2) Interacting with an External Plasma Wind

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.; Euripides, P.; Ziemba, T.; Slough, J.; Giersch, L.

    2003-01-01

    Substantial progress has been made over the last year in the development of the laboratory Mini-Magnetospheric Plasma Propulsion (M2P2) prototype. The laboratory testing has shown that that the plasma can be produced at high neutral gas efficiency, at high temperatures (a few tens of eV) with excellent confinement up to the point where chamber wall interactions dominate the physics. This paper investigates the performance of the prototype as it is opposed by an external plasma acting as a surrogate for the solar wind. The experiments were performed in 5ft diameter by 6ft long vacuum chamber at the University of Washington. The solar wind source comprised of a 33 kWe arc jet attached to a 200 kWe inductively generated plasma source. The dual plasma sources allow the interaction to be studied for different power levels, shot duration and production method. It is shown that plasma from the solar wind source (SWS) is able to penetrate the field of the M2P2 magnetic when no plasma is present. With operation of the M2P2 plasma source at only 1.5 kWe, the penetration of the SWS even at the highest power of operation at 200 kWe is stopped. This deflection is shown to be greatly enhanced over that produced by the magnet alone. In addition it is shown that with the presence of the SWS, M2P2 is able to produce enhanced magnetized plasma production out to at least 10 magnet radii where the field strength is only marginally greater than the terrestrial field. The results are consistent with the initial predictions that kWe M2P2 systems would be able to deflect several hundred kWe plasma winds to produce enhanced propulsion for a spacecraft.

  8. Deactivation of Ni2P/SiO2 catalyst in hydrodechlorination of chlorobenzene

    NASA Astrophysics Data System (ADS)

    Chen, Jixiang; Ci, Donghui; Yang, Qing; Li, Kelun

    2014-11-01

    The deactivation of the Ni2P/SiO2 catalyst in the hydrodechlorination of chlorobenzene was studied. To better illuminate the reasons for the deactivation, the effect of HCl on the structure and activity of Ni2P/SiO2 was investigated. For comparison, the deactivation of the Ni/SiO2 catalyst was also involved. It was found that the Ni2P particles possessed good resistance to HCl poison and to sintering, which is ascribed to the electron-deficiency of Niδ+(0 < δ < 1) site in Ni2P. Acted as the Lewis and Brönsted acid site, the Niδ+ site and the Psbnd OH group on Ni2P/SiO2 catalyzed the formation of the carbonaceous deposit that was difficultly eliminated by hydrogenation. The carbonaceous deposit covered the active sites and might also induce a decrease in the Ni2P crystallinity, subsequently leading to the Ni2P/SiO2 deactivation. Different from Ni2P/SiO2, Ni/SiO2 was mainly deactivated by the chlorine poison and the sintering of nickel crystallites.

  9. A Study of Perkins 2P1 Graduation Performance Rates at Virginia Western Community College

    ERIC Educational Resources Information Center

    Archer, J. Andrew.

    2006-01-01

    "2P1" is the Carl Perkins label for an institution's graduation performance rate. Systems receiving Perkins funds, like Virginia's 23 community colleges, are expected to meet a federally approved 2P1 target rate. For the 3-year period 1999-2001 Virginia Western Community College (VWCC) was one of seven community colleges in the VCCS (Virginia…

  10. 29 CFR 1917.22 - Hazardous cargo 2 (See § 1917.2(p)).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... § 1917.2(p)). 2 The Department of Transportation and the United States Coast Guard apply requirements related to handling, storing and transportation of hazardous cargo (see 33 CFR part 126, 46 CFR, 49 CFR... 29 Labor 7 2010-07-01 2010-07-01 false Hazardous cargo 2 (See § 1917.2(p)). 1917.22 Section...

  11. 29 CFR 1917.22 - Hazardous cargo 2 (See § 1917.2(p)).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... § 1917.2(p)). 2 The Department of Transportation and the United States Coast Guard apply requirements related to handling, storing and transportation of hazardous cargo (see 33 CFR part 126, 46 CFR, 49 CFR... 29 Labor 7 2014-07-01 2014-07-01 false Hazardous cargo 2 (See § 1917.2(p)). 1917.22 Section...

  12. 29 CFR 1917.22 - Hazardous cargo 2 (See § 1917.2(p)).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... § 1917.2(p)). 2 The Department of Transportation and the United States Coast Guard apply requirements related to handling, storing and transportation of hazardous cargo (see 33 CFR part 126, 46 CFR, 49 CFR... 29 Labor 7 2011-07-01 2011-07-01 false Hazardous cargo 2 (See § 1917.2(p)). 1917.22 Section...

  13. 29 CFR 1917.22 - Hazardous cargo 2 (See § 1917.2(p)).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... § 1917.2(p)). 2 The Department of Transportation and the United States Coast Guard apply requirements related to handling, storing and transportation of hazardous cargo (see 33 CFR part 126, 46 CFR, 49 CFR... 29 Labor 7 2013-07-01 2013-07-01 false Hazardous cargo 2 (See § 1917.2(p)). 1917.22 Section...

  14. 29 CFR 1917.22 - Hazardous cargo 2 (See § 1917.2(p)).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... § 1917.2(p)). 2 The Department of Transportation and the United States Coast Guard apply requirements related to handling, storing and transportation of hazardous cargo (see 33 CFR part 126, 46 CFR, 49 CFR... 29 Labor 7 2012-07-01 2012-07-01 false Hazardous cargo 2 (See § 1917.2(p)). 1917.22 Section...

  15. Spin polarization and magnetic dichroism in photoemission from core and valence states in localized magnetic systems. IV. Core-hole polarization in resonant photoemission

    NASA Astrophysics Data System (ADS)

    van der Laan, Gerrit; Thole, B. T.

    1995-12-01

    A simple theory is presented for core-hole polarization probed by resonant photoemission in a two-steps approximation. After excitation from a core level to the valence shell, the core hole decays into two shallower core holes under emission of an electron. The nonspherical core hole and the final state selected cause a specific angle and spin distribution of the emitted electron. The experiment is characterized by the ground-state moments, the polarization of the light, and the spin and angular distribution of the emitted electron. The intensity is a sum over ground-state expectation values of tensor operators times the probability to create a polarized core hole using polarized light, times the probability for decay of such a core hole into the final state. We give general expressions for the angle- and spin-dependent intensities in various regimes of Coulomb and spin-orbit interaction: LS, LSJ, and jjJ coupling. The core-polarization analysis, which generalizes the use of sum rules in x-ray absorption spectroscopy where the integrated peak intensities give ground-state expectation values of the spin and orbital moment operators, makes it possible to measure different linear combinations of these operators. As an application the 2p3/23p3p decay in ferromagnetic nickel is calculated using Hartree-Fock values for the radial matrix elements and phase factors, and compared with experiment, the dichroism is smaller in the 3P final state but stronger in the 1D, 1S peak.

  16. Fuzzy-rule-based Adaptive Resource Control for Information Sharing in P2P Networks

    NASA Astrophysics Data System (ADS)

    Wu, Zhengping; Wu, Hao

    With more and more peer-to-peer (P2P) technologies available for online collaboration and information sharing, people can launch more and more collaborative work in online social networks with friends, colleagues, and even strangers. Without face-to-face interactions, the question of who can be trusted and then share information with becomes a big concern of a user in these online social networks. This paper introduces an adaptive control service using fuzzy logic in preference definition for P2P information sharing control, and designs a novel decision-making mechanism using formal fuzzy rules and reasoning mechanisms adjusting P2P information sharing status following individual users' preferences. Applications of this adaptive control service into different information sharing environments show that this service can provide a convenient and accurate P2P information sharing control for individual users in P2P networks.

  17. Magnetic circular dichroism in the ion yield of polarized chromium atoms at the 2p edge

    SciTech Connect

    Pruemper, G.; Viefhaus, J.; Becker, U.; Kroeger, S.; Mueller, R.; Zimmermann, P.; Martins, M.

    2003-09-01

    The effect of magnetic dichroism in the partial and total ion yield of chromium, i.e., the absorption of polarized chromium vapor was observed in the gas phase. The measurements were performed at the 2p edge and at photon energies above the 2p edge. The structure of the dichroism at the 2p edge can be understood by including the coupling of the 2p hole with the 3d and 4s shells. Our experimental results for the dichroism at the 2p edge are similar to results of solid-state experiments. Implications for the sum rules used as a standard tool to calculate the spin and orbital momentum are discussed.

  18. Convergence of Internet and TV: The Commercial Viability of P2P Content Delivery

    NASA Astrophysics Data System (ADS)

    de Boever, Jorn

    The popularity of (illegal) P2P (peer-to-peer) file sharing has a disruptive impact on Internet traffic and business models of content providers. In addition, several studies have found an increasing demand for bandwidth consuming content, such as video, on the Internet. Although P2P systems have been put forward as a scalable and inexpensive model to deliver such content, there has been relatively little economic analysis of the potentials and obstacles of P2P systems as a legal and commercial content distribution model. Many content providers encounter uncertainties regarding the adoption or rejection of P2P networks to spread content over the Internet. The recent launch of several commercial, legal P2P content distribution platforms increases the importance of an integrated analysis of the Strengths, Weaknesses, Opportunities and Threats (SWOT).

  19. Core Journal Lists: Classic Tool, New Relevance

    ERIC Educational Resources Information Center

    Paynter, Robin A.; Jackson, Rose M.; Mullen, Laura Bowering

    2010-01-01

    Reviews the historical context of core journal lists, current uses in collection assessment, and existing methodologies for creating lists. Outlines two next generation core list projects developing new methodologies and integrating novel information/data sources to improve precision: a national-level core psychology list and the other a local…

  20. Estimation of turbulence characteristics of the low-level eyewall and outer-core regions in intense Hurricanes Allen (1980) and Hugo (1989)

    NASA Astrophysics Data System (ADS)

    Zhang, J. A.; Marks, F. D.; Montgomery, M.; Lorsolo, S.

    2010-12-01

    Turbulent transport processes in the atmospheric boundary layer play an important role in the intensification and maintenance of a hurricane vortex. However, direct measurement of turbulence in the hurricane boundary layer has been scarce. This study analyzes the flight-level data collected by research aircraft that penetrated the eyewalls of Category 5 Hurricane Hugo (1989) and Category 4 Hurricane Allen (1980) between 1 km and the sea surface. Momentum flux, turbulent kinetic energy (TKE) and vertical eddy diffusivity are estimated before and during the eyewall penetrations. Spatial scales of turbulent eddies are determined through spectral analysis. The turbulence parameters estimated for the eyewall penetration leg are found to be nearly an order of magnitude larger than those for the leg outside the eyewall at similar altitudes. In the low-level intense eyewall region, the horizontal length scale of dominant turbulent eddies is found to be between 500 - 3000 m and the corresponding vertical length scale is approximately 100 - 200 m. The results suggest also that it is unwise to include the eyewall vorticity maximum (EVM) in the turbulence parameter estimation, since the EVMs are likely to be quasi two-dimensional vortex structures that are embedded within the three dimensional turbulence on the inside edge of the eyewall.

  1. Electron Excitation Cross Sections for the C II Transitions 2s(exp 2)2p P-2(exp 0) yields 2s2p(exp 2) P-4, D-2, and S-2

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

    Experimental and theoretical excitation cross sections are reported for the transitions 2s(exp 2) 2p-2(exp 0) yield 2s2p(exp 2)P-4, D-2, and S-2 in C II. The transition wavelengths (energies) are 2324 A (5.34 eV), 1335 x (9.29 eV), and 1036 A (11.97 eV), respectively. Use is made of electron energy-loss and merged beams methods. The energy range covered is from below each threshold (4 - 11 eV) to 15-24 eV. As in previous work with O II, care was taken to assess and minimize the metastable fraction in the C II beam, to account for contributions from nearby energy-loss features, and to collect the full angular range of inelastically scattered electrons. A comparison is made for each transition between experiment and new 8-state R-matrix calculations. Subject headings: atomic data ultraviolet: general

  2. Kinetics of an oxygen - iodine active medium with iodine atoms optically pumped on the 2P1/2 - 2P3/2 transition

    NASA Astrophysics Data System (ADS)

    Zagidullin, M. V.; Malyshev, M. S.; Azyazov, V. N.

    2015-08-01

    The kinetics of the processes occurring in an O2 - I2 - He - H2O gas flow in which photodissociation of molecular iodine at a wavelength close to 500 nm and excitation of atomic iodine on the 2P1/2 - 2P3/2 transition by narrow-band radiation near 1315 nm are implemented successively has been analysed. It is shown that implementation of these processes allows one to form an oxygen - iodine medium with a high degree of dissociation of molecular iodine and a relative content of singlet oxygen O2(a1Δ) exceeding 10%. Having formed a supersonic gas flow with a temperature ~100 K from this medium, one can reach a small-signal gain of about 10-2 cm-1 on the 2P1/2 - 2P3/2 transition in iodine atoms. The specific power per unit flow cross section in the oxygen - iodine laser with this active medium may reach ~100 W cm-2.

  3. Aberrant activation of the androgen receptor by NF-kappaB2/p52 in prostate cancer cells.

    PubMed

    Nadiminty, Nagalakshmi; Lou, Wei; Sun, Meng; Chen, Jun; Yue, Jiao; Kung, Hsing-Jien; Evans, Christopher P; Zhou, Qinghua; Gao, Allen C

    2010-04-15

    Prostate cancer initiation and progression are uniquely dependent on the androgen receptor (AR). Even when the cancer progresses to a castration-resistant stage, AR signaling remains active via a variety of mechanisms. In the present study, we showed that NF-kappaB/p52 can activate the AR, resulting in increased transactivation of AR-responsive genes, such as PSA and NKX3.1, in a ligand-independent manner. NF-kappaB2/p52 enhances nuclear translocation and activation of AR by interacting with its NH(2)-terminal domain and enhances the recruitment of coactivators such as p300 to the promoters of AR-dependent genes. These results were confirmed in three different prostate cancer cell lines: LAPC-4 (wild-type AR), LNCaP (mutant AR), and C4-2 (castration resistant). Transfection of p52 into LAPC-4 and LNCaP cells (which express low levels of p52) showed increased activation of the endogenous AR. Downregulation of endogenous p52 in C4-2 cells resulted in abrogation of AR constitutive activation. Comparison of the relative effects of p52 and p65 (RelA) showed that p52, but not p65, could activate the AR. Collectively, these findings, together with previous reports that the levels of NF-kappaB2/p52 are elevated in prostate cancer cells and that active NF-kappaB2/p52 promotes prostate cancer cell growth in vitro and in vivo, suggest that NF-kappaB2/p52 may play a critical role in the progression of castration-resistant prostate cancer.

  4. Critical CRBR core pressure

    SciTech Connect

    Ju, F.D.

    1980-06-01

    The conditions are detailed under which gas pressure will cause or initiate failure in the structural containment of the fuel core. The Clinch River Breeder Reactor Plant is the prototype structure. Two general classes of problems have been studied, representing two entirely distinct configurations of containment failure. The first model determines the minimum pressure to lift a portion or the entire core from its containment. The second model estimates the critical pressure above which the fuel rods interior to the hexagonal fuel can warp, leading to blockage of the gas passages. Such blockage might cause further buildup of the gas pressure to a level causing the failure of the fuel rod containment in the hexagonal fuel container.

  5. Attosecond photoionization dynamics with stimulated core-valence transitions

    NASA Astrophysics Data System (ADS)

    You, Jhih-An; Rohringer, Nina; Dahlström, Jan Marcus

    2016-03-01

    We investigate ionization of neon atoms by an isolated attosecond pump pulse in the presence of two coherent extreme ultraviolet or x-ray probe fields. The probe fields are tuned to a core-valence transition in the residual ion and induce spectral shearing of the photoelectron distributions. We show that the photoelectron-ion coincidence signal contains an interference pattern that depends on the temporal structure of the attosecond pump pulse and the stimulated core-valence transition. Many-body perturbation theory is used to compute "atomic response times" for the processes and we find strikingly different behavior for stimulation to the outer-core hole (2 p ↔2 s ) and stimulation to the inner-core hole (2 p ↔1 s ). The response time of the inner-core transition is found to be comparable to that of state-of-the-art laser-based characterization techniques for attosecond pulses.

  6. Solution structure of the ubiquitin-binding domain in Swa2p from Saccharomyces cerevisiae.

    PubMed

    Chim, Nicholas; Gall, Walter E; Xiao, Jing; Harris, Mark P; Graham, Todd R; Krezel, Andrzej M

    2004-03-01

    The SWA2/AUX1 gene has been proposed to encode the Saccharomyces cerevisiae ortholog of mammalian auxilin. Swa2p is required for clathrin assembly/dissassembly in vivo, thereby implicating it in intracellular protein and lipid trafficking. While investigating the 287-residue N-terminal region of Swa2p, we found a single stably folded domain between residues 140 and 180. Using binding assays and structural analysis, we established this to be a ubiquitin-associated (UBA) domain, unidentified by bioinformatics of the yeast genome. We determined the solution structure of this Swa2p domain and found a characteristic three-helix UBA fold. Comparisons of structures of known UBA folds reveal that the position of the third helix is quite variable. This helix in Swa2p UBA contains a bulkier tyrosine in place of smaller residues found in other UBAs and cannot pack as close to the second helix. The molecular surface of Swa2p UBA has a mostly negative potential, with a single hydrophobic surface patch found also in the UBA domains of human protein, HHR23A. The presence of a UBA domain implicates Swa2p in novel roles involving ubiquitin and ubiquitinated substrates. We propose that Swa2p is a multifunctional protein capable of recognizing several proteins through its protein-protein recognition domains. PMID:14997574

  7. Cloning, sequence analysis and radiation hybrid mapping of a mammalian KRT2p gene.

    PubMed

    Miller, A B; Lowe, J K; Ostrander, E A; Galibert, F; Murphy, K E

    2001-09-01

    We report here on the cloning, characterization and radiation hybrid mapping of the canine basic keratin gene KRT2p. The gene spans 8.3 kb, consists of nine exons and eight introns, and is characterized by the typical features of both basic keratins and keratins in general, including glycine-rich head and tail domains, which flank an alpha-helical rod domain of approximately 310 amino acids. Comparisons of sequence and structure reveal that canine KRT2p is strikingly similar to human KRT2p. Alignment of the predicted amino acid sequences for human and dog reveals greater than 80% identity. In the rod domain, the amino acid identity exceeds 90%. We note, however, that canine KRT2p encodes a protein 21 residues longer than human K2p due to the insertion of a glycine repeat motif, GG(G)X, in the head and tail domains of the canine gene. This is the first report of the nearly complete genome sequence for KRT2p of any organism. Radiation hybrid mapping of canine KRT2p to chromosome 27 of the dog is also reported. PMID:11793249

  8. Uranium droplet core nuclear rocket

    NASA Technical Reports Server (NTRS)

    Anghaie, Samim

    1991-01-01

    Uranium droplet nuclear rocket is conceptually designed to utilize the broad temperature range ofthe liquid phase of metallic uranium in droplet configuration which maximizes the energy transfer area per unit fuel volume. In a baseline system dissociated hydrogen at 100 bar is heated to 6000 K, providing 2000 second of Isp. Fission fragments and intense radian field enhance the dissociation of molecular hydrogen beyond the equilibrium thermodynamic level. Uranium droplets in the core are confined and separated by an axisymmetric vortex flow generated by high velocity tangential injection of hydrogen in the mid-core regions. Droplet uranium flow to the core is controlled and adjusted by a twin flow nozzle injection system.

  9. Lateral MoS2 p-n junctions formed by chemical doping method

    NASA Astrophysics Data System (ADS)

    Yoo, Won Jong; Choi, Min Sup; Qu, Deshun; Lee, Daeyeong; Liu, Xiaochi; Jang, Youngdae; Kim, Changsik; Ryu, Jungjin

    2015-03-01

    Interests on transition metal dichalcogenides, especially MoS2, are growing immensely due to its semiconducting nature with visible light range bandgap and strong light absorption property, which can pave the way to replace Si-based electronics and realize flexible and transparent electronics. For more versatile applications and industrialization, however, a proper doping process is required because various devices such as photonics and tunneling devices are composed of p-n junctions. Here, we demonstrated the formation of lateral MoS2 p-n junction by using partially stacked of hBN and p-doping with Au Cl3 solution. The fabricated devices showed an ideal rectifying behavior with ideality factor about 1. Under the exposure of monochromatic light, it revealed the properties of conventional p-n diode and also highly efficient photonic properties, showing feasibility to be applied for photovoltaic cells and photodetectors. Furthermore, we fabricated novel tunneling devices with similar device structure where local gates are located under MoS2. Its Fermi level can be effectively controlled by local gate modulation, so that the tunneling current can flow by band-to-band tunneling. This study provides an effective way to realize the practical devices such as photonics and tun

  10. Efficient Plasma Production in Low Background Neutral Pressures with the M2P2 Prototype

    NASA Technical Reports Server (NTRS)

    Ziemba, T.; Euripides, P.; Winglee, R.; Slough, J.; Giersch, L.

    2003-01-01

    Mini-Magnetospheric Plasma Propulsion (M2P2) seeks the creation of a large-scale (10 km radius) magnetic wall or bubble (i.e. a magnetosphere) by the electromagnetic inflation of a small-scale (20 cm radius) dipole magnet. The inflated magnetosphere will intercept the solar wind and thereby provide high-speed propulsion with modest power and fuel requirements due to the gain provided by the ambient medium. Magnetic field inflation is produced by the injection of plasma onto the dipole magnetic field eliminating the need for large mechanical structures and added material weight at launch. For successful inflation of the magnetic bubble a beta near unity must be achieved along the imposed dipole field. This is dependent on the plasma parameters that can be achieved with a plasma source that provide continuous operation at the desired power levels of 1 to 2 kilowatts. Over the last two years we have been developing a laboratory prototype to demonstrate the inflation of the magnetic field under space-like conditions. In this paper we will present some of the latest results from the prototype development at the University of Washington and show that the prototype can produce high ionization efficiencies while operating in near space like neutral background pressures producing electron temperatures of a few tens of electron volts. This allows for operation with propellant expenditures lower than originally estimated.

  11. Proteome of Salmonella enterica serotype Tyhimurium Grown in Low Mg2+/pH Medium

    SciTech Connect

    Shi, Liang; Ansong, Charles; Smallwood, Heather S.; Rommereim, Leah M.; McDermott, Jason E.; Brewer, Heather M.; Norbeck, Angela D.; Taylor, Ronald C.; Gustin, Jean K.; Heffron, Fred; Smith, Richard D.; Adkins, Joshua N.

    2009-09-04

    To determine the impact of a low Mg2+/pH defined growth medium (MgM) on the proteome of Salmonella enterica serotype Typhimurium, we cultured S. Typhimurium cells in the medium under two different conditions termed MgM Shock and MgM Dilution and then comparatively analyzed the bacterial cells harvested from these conditions by a global proteomic approach. Proteomic results showed that MgM Shock and MgM Dilution differentially affected the S. Typhimurium proteome. MgM Shock induced a group of proteins whose induction usually occurred at low O2 level, while MgM Dilution induced those related to the type III secretion system (T3SS) of Salmonella Pathogenicity Island 2 (SPI2) and those involved in thiamine or biotin biosynthesis. The metabolic state of the S. Typhimurium cells grown under MgM Shock condition also differed significantly from that under MgM Dilution condition. Western blot analysis not only confirmed the proteomic results, but also showed that the abundances of SPI2-T3SS proteins SsaQ and SseE and biotin biosynthesis proteins BioB and BioD increased after S. Typhimurium infection of RAW 264.7 macrophages. Deletion of the gene encoding BioB reduced the bacterial ability to replicate inside the macrophages, suggesting a biotin-limited environment encountered by S. Typhimurium within RAW 264.7 macrophages.

  12. Dual-core antiresonant hollow core fibers.

    PubMed

    Liu, Xuesong; Fan, Zhongwei; Shi, Zhaohui; Ma, Yunfeng; Yu, Jin; Zhang, Jing

    2016-07-25

    In this work, dual-core antiresonant hollow core fibers (AR-HCFs) are numerically demonstrated, based on our knowledge, for the first time. Two fiber structures are proposed. One is a composite of two single-core nested nodeless AR-HCFs, exhibiting low confinement loss and a circular mode profile in each core. The other has a relatively simple structure, with a whole elliptical outer jacket, presenting a uniform and wide transmission band. The modal couplings of the dual-core AR-HCFs rely on a unique mechanism that transfers power through the air. The core separation and the gap between the two cores influence the modal coupling strength. With proper designs, both of the dual-core fibers can have low phase birefringence and short modal coupling lengths of several centimeters.

  13. Reverse-engineering the atomic-scale structure of the TiO2/N3 interface in dye-sensitized solar cells using O1s core-level shifts

    NASA Astrophysics Data System (ADS)

    Patrick, Christopher; Giustino, Feliciano

    2011-03-01

    Dye-sensitized solar cells employing mesoporous titania films sensitized with ruthenium-based dyes have shown consistently good performance over the past two decades. Understanding the process of charge injection in these devices requires accurate atomistic models of the interface between the light-absorbing dye and the semiconducting substrate. Despite considerable efforts devoted to the experimental and theoretical investigation of such interfaces, their atomistic nature remains controversial. In this work we pursue a novel computational approach to the study of the semiconductor/dye interface which does not rely on the calculated adsorption energies. In our approach we reverse-engineer photoemission data through the first-principles calculation of O1s core-level spectra for a number of candidate interface models. Our calculations allow us to discard some of the adsorption geometries previously proposed and point to an interface model which reconciles conflicting assignments based either on photoemission or infrared data.

  14. Absolute cross sections for near-threshold electron-impact excitation of the 2s 2S-->2p 2P transition in C3+

    NASA Astrophysics Data System (ADS)

    Bannister, M. E.; Chung, Y.-S.; Djurić, N.; Wallbank, B.; Woitke, O.; Zhou, S.; Dunn, G. H.; Smith, A. C.

    1998-01-01

    Absolute total cross sections for electron-impact excitation of the 2s 2S-->2p 2P transition in C3+ were measured from 7.35 eV to 8.45 eV using the merged electron-ion-beams energy-loss technique. The results settle the discrepancy between two previous experiments using the crossed-beams fluorescence method, being in very good agreement with the older results [P. O. Taylor, D. Gregory, G. H. Dunn, R. A. Phaneuf, and D. H. Crandall, Phys. Rev. Lett. 39, 1256 (1977)] but less so with the more recent ones [D. W. Savin, L. D. Gardner, D. B. Reisenfeld, A. R. Young, and J. L. Kohl, Phys. Rev. A 51, 2162 (1995)]. The present measurements are also in good agreement with unitarized Coulomb-Born and close-coupling calculations.

  15. The Effect of Etching Time on Rectifying Characteristic in SnO2/p-Si and SnO2/p-PoSi Heterojunction Schottky Diodes

    NASA Astrophysics Data System (ADS)

    Biaram, Alireza; Eshghi, Hosein

    2013-03-01

    We have fabricated SnO2/p-Si and SnO2/p-PoSi heterojunction diodes by spray pyrolysis method. To prepare porous Si substrates, the etching time was varied from 10 to 20 and 30 mins. In these samples, the SEM micrographs showed a distributed pore areas surrounded by columnar walls with various height. The data analysis of the rectified I-V characteristic, using thermionic emission Schottky diode theory, showed that although the barrier height is about 0.5-0.6 eV in all samples other two important diode parameters, i.e. the ideality factor n and the series resistance rs, are strongly etching time-dependant and are increased with increasing the etching time.

  16. Security Issues for P2P-Based Voice- and Video-Streaming Applications

    NASA Astrophysics Data System (ADS)

    Seedorf, Jan

    P2P computing offers a new interesting field for security researchers. Being highly distributed and lacking centralised, trusted entities for bootstrapping security mechanisms, these systems demand novel approaches for decentralised security solutions.

  17. 2. P.S. Rittermann, Photographer February 1995 BUILDING 990, WEST SIDE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. P.S. Rittermann, Photographer February 1995 BUILDING 990, WEST SIDE. - Presidio of San Francisco, Flammable Storage Building Submarine Mine Depot, Fort Point vicinity, Long Avenue, San Francisco, San Francisco County, CA

  18. Amyloid-like properties of Saccharomyces cerevisiae cell wall glucantransferase Bgl2p

    PubMed Central

    Plotnikova, Tatyana A; Gorkovskii, Anton A; Selyakh, Irina O; Galzitskaya, Oxana V; Bezsonov, Evgeniy E; Gellissen, Gerd; Kulaev, Igor S

    2008-01-01

    Glucantransferase Bgl2p is a major conserved cell wall constituent described for a wide range of yeast species. In the baker's yeast Saccharomyces cerevisiae it is the only non-covalently bound cell wall protein that cannot be released from cell walls by sequential SDS and trypsin treatment. It contains seven amyloidogenic determinants. Circular dichroism analysis and fluorescence spectroscopy with thioflavin T indicate the presence of β-sheet structures in Bgl2p isolates. Bgl2p forms fibrils, a process that is enforced in the presence of other cell wall components. Thus the data obtained is the first evidence for amyloid-like properties of yeast cell wall protein—glucantransferase Bgl2p. PMID:19098439

  19. 49 CFR 178.33 - Specification 2P; inner nonrefillable metal receptacles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 2P; inner nonrefillable metal receptacles. 178.33 Section 178.33 Transportation Other Regulations Relating to Transportation (Continued... nonrefillable metal receptacles....

  20. 49 CFR 178.33 - Specification 2P; inner nonrefillable metal receptacles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Specification 2P; inner nonrefillable metal receptacles. 178.33 Section 178.33 Transportation Other Regulations Relating to Transportation PIPELINE AND... nonrefillable metal receptacles....

  1. 49 CFR 178.33 - Specification 2P; inner nonrefillable metal receptacles.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 2P; inner nonrefillable metal receptacles. 178.33 Section 178.33 Transportation Other Regulations Relating to Transportation (Continued... nonrefillable metal receptacles....

  2. 49 CFR 178.33 - Specification 2P; inner nonrefillable metal receptacles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 2P; inner nonrefillable metal receptacles. 178.33 Section 178.33 Transportation Other Regulations Relating to Transportation (Continued... nonrefillable metal receptacles....

  3. A study of angle-resolved photoemission extended fine structure as applied to the Ni 3p, Cu 3s, and Cu 3p core levels of the respective clean (111) surfaces

    SciTech Connect

    Huff, W.R.A.; Moler, E.J.; Kellar, S.A.

    1997-04-01

    The first non-s initial state angle-resolved photoemission extended fine structure (ARPEFS) study of clean surfaces for the purpose of further understanding the technique is reported. The surface structure sensitivity of ARPEFS applied to clean surfaces and to arbitrary initial states is studied using normal photoemission data taken from the Ni 3p core levels of a Ni(111) single crystal and the Cu 3s and the Cu 3p core-levels of a Cu(111) single crystal. The Fourier transforms of these clean surface data are dominated by backscattering. Unlike the s initial state data, the p initial state data show a peak in the Fourier transform corresponding to in-plane scattering from the six nearest-neighbors to the emitter. Evidence was seen for single-scattering events from in the same plane as the emitters and double-scattering events. Using a newly developed, multiple-scattering calculation program, ARPEFS data from clean surfaces and from p initial states can be modeled to high precision. Although there are many layers of emitters when measuring photoemission from a clean surface, test calculations show that the ARPEFS signal is dominated by photoemission from atoms in the first two crystal layers. Thus, ARPEFS applied to clean surfaces is sensitive to surface reconstruction. The known contraction of the first two Cu(111) layers is confirmed. The best-fit calculation for clean Ni(111) indicates an expansion of the first two layers. To better understand the ARPEFS technique, the authors studied s and non-s initial state photoemission from clean metal surfaces.

  4. Genomic organization and chromosomal localization of the murine 2 P domain potassium channel gene Kcnk8: conservation of gene structure in 2 P domain potassium channels.

    PubMed

    Bockenhauer, D; Nimmakayalu, M A; Ward, D C; Goldstein, S A; Gallagher, P G

    2000-12-31

    A 2 P domain potassium channel expressed in eye, lung, and stomach, Kcnk8, has recently been identified. To initiate further biochemical and genetic studies of this channel, we assembled the murine Kcnk8 cDNA sequence, characterized the genomic structure of the Kcnk8 gene, determined its chromosomal localization, and analyzed its activity in a Xenopus laevis oocyte expression system. The composite cDNA has an open reading frame of 1029 bp and encodes a protein of 343 amino acids with a predicted molecular mass of 36 kDa. Structure analyses predict 2 P domains and four potential transmembrane helices with a potential single EF-hand motif and four potential SH3-binding motifs in the COOH-terminus. Cloning of the Kcnk8 chromosomal gene revealed that it is composed of three exons distributed over 4 kb of genomic DNA. Genome database searching revealed that one of the intron/exon boundaries identified in Kcnk8 is present in other mammalian 2 P domain potassium channels genes and many C. elegans 2P domain potassium channel genes, revealing evolutionary conservation of gene structure. Using fluorescence in situ hybridization, the murine Kcnk8 gene was mapped to chromosome 19, 2B, the locus of the murine dancer phenotype, and syntenic to 11q11-11q13, the location of the human homologue. No significant currents were generated in a Xenopus laevis oocyte expression system using the composite Kcnk8 cDNA sequence, suggesting, like many potassium channels, additional channel subunits, modulator substances, or cellular chaperones are required for channel function.

  5. An Efficient, Scalable and Robust P2P Overlay for Autonomic Communication

    NASA Astrophysics Data System (ADS)

    Li, Deng; Liu, Hui; Vasilakos, Athanasios

    The term Autonomic Communication (AC) refers to self-managing systems which are capable of supporting self-configuration, self-healing and self-optimization. However, information reflection and collection, lack of centralized control, non-cooperation and so on are just some of the challenges within AC systems. Since many self-* properties (e.g. selfconfiguration, self-optimization, self-healing, and self-protecting) are achieved by a group of autonomous entities that coordinate in a peer-to-peer (P2P) fashion, it has opened the door to migrating research techniques from P2P systems. P2P's meaning can be better understood with a set of key characteristics similar to AC: Decentralized organization, Self-organizing nature (i.e. adaptability), Resource sharing and aggregation, and Fault-tolerance. However, not all P2P systems are compatible with AC. Unstructured systems are designed more specifically than structured systems for the heterogeneous Internet environment, where the nodes' persistence and availability are not guaranteed. Motivated by the challenges in AC and based on comprehensive analysis of popular P2P applications, three correlative standards for evaluating the compatibility of a P2P system with AC are presented in this chapter. According to these standards, a novel Efficient, Scalable and Robust (ESR) P2P overlay is proposed. Differing from current structured and unstructured, or meshed and tree-like P2P overlay, the ESR is a whole new three dimensional structure to improve the efficiency of routing, while information exchanges take in immediate neighbors with local information to make the system scalable and fault-tolerant. Furthermore, rather than a complex game theory or incentive mechanism, asimple but effective punish mechanism has been presented based on a new ID structure which can guarantee the continuity of each node's record in order to discourage negative behavior on an autonomous environment as AC.

  6. Structure And Function of the Yeast U-Box-Containing Ubiquitin Ligase Ufd2p

    SciTech Connect

    Tu, D.; Li, W.; Ye, Y.; Brunger, A.T.

    2009-06-04

    Proteins conjugated by Lys-48-linked polyubiquitin chains are preferred substrates of the eukaryotic proteasome. Polyubiquitination requires an activating enzyme (E1), a conjugating enzyme (E2), and a ligase (E3). Occasionally, these enzymes only assemble short ubiquitin oligomers, and their extension to full length involves a ubiquitin elongating factor termed E4. Ufd2p, as the first E4 identified to date, is involved in the degradation of misfolded proteins of the endoplasmic reticulum and of a ubiquitin-{beta}-GAL fusion substrate in Saccharomyces cerevisiae. The mechanism of action of Ufd2p is unknown. Here we describe the crystal structure of the full-length yeast Ufd2p protein. Ufd2p has an elongated shape consisting of several irregular Armadillo-like repeats with two helical hairpins protruding from it and a U-box domain flexibly attached to its C terminus. The U-box of Ufd2p has a fold similar to that of the RING (Really Interesting New Gene) domain that is present in certain ubiquitin ligases. Accordingly, Ufd2p has all of the hallmarks of a RING finger-containing ubiquitin ligase: it associates with its cognate E2 Ubc4p via its U-box domain and catalyzes the transfer of ubiquitin from the E2 active site to Ufd2p itself or to an acceptor ubiquitin molecule to form unanchored diubiquitin oligomers. Thus, Ufd2p can function as a bona fide E3 ubiquitin ligase to promote ubiquitin chain elongation on a substrate.

  7. Gating, Regulation, and Structure in K2P K+ Channels: In Varietate Concordia?

    PubMed

    Niemeyer, María Isabel; Cid, L Pablo; González, Wendy; Sepúlveda, Francisco V

    2016-09-01

    K2P K(+) channels with two pore domains in tandem associate as dimers to produce so-called background conductances that are regulated by a variety of stimuli. Whereas gating in K2P channels has been poorly understood, recent developments have provided important clues regarding the gating mechanism for this family of proteins. Two modes of gating present in other K(+) channels have been considered. The first is the so-called activation gating that occurs by bundle crossing and the splaying apart of pore-lining helices commanding ion passage. The second mode involves a change in conformation at the selectivity filter (SF), which impedes ion flow at this narrow portion of the conduction pathway and accounts for extracellular pH modulation of several K2P channels. Although some evidence supports the existence of an activation gate in K2P channels, recent results suggest that perhaps all stimuli, even those sensed at a distant location in the protein, are also mediated by SF gating. Recently resolved crystal structures of K2P channels in conductive and nonconductive conformations revealed that the nonconductive state is reached by blockade by a lipid acyl chain that gains access to the channel cavity through intramembrane fenestrations. Here we discuss whether this novel type of gating, proposed so far only for membrane tension gating, might mediate gating in response to other stimuli or whether SF gating is the only type of opening/closing mechanism present in K2P channels. PMID:27268784

  8. Occupied and unoccupied electronic structures of an L-cysteine film studied by core-absorption and resonant photoelectron spectroscopies

    NASA Astrophysics Data System (ADS)

    Kamada, M.; Hideshima, T.; Azuma, J.; Yamamoto, I.; Imamura, M.; Takahashi, K.

    2016-04-01

    Unoccupied and occupied electronic structures of an L-cysteine film have been studied by absorption and resonant photoelectron spectroscopies. Core absorptions at S-L, C-K, N-K, and O-K levels indicate that the lower unoccupied states are predominantly composed of oxygen-2p, carbon-2p, and sulfur-4s+3d orbitals, while higher unoccupied states may be attributed dominantly to nitrogen-np (n ≥ 3), oxygen-np (n ≥ 3), and sulfur-ns+md (n ≥ 4, m ≥ 3) orbitals. Resonant photoelectron spectra at S-L23 and O-K levels indicate that the highest occupied state is originated from sulfur-3sp orbitals, while oxygen-2sp orbitals contribute to the deeper valence states. The delocalization lifetimes of the oxygen-1s and sulfur-2p excited states are estimated from a core-hole clock method to be about 9 ± 1 and 125 ± 25 fs, respectively.

  9. Lifetime of inner-shell hole states of Ar (2p) and Kr (3d) using equation-of-motion coupled cluster method

    SciTech Connect

    Ghosh, Aryya; Vaval, Nayana; Pal, Sourav

    2015-07-14

    Auger decay is an efficient ultrafast relaxation process of core-shell or inner-shell excited atom or molecule. Generally, it occurs in femto-second or even atto-second time domain. Direct measurement of lifetimes of Auger process of single ionized and double ionized inner-shell state of an atom or molecule is an extremely difficult task. In this paper, we have applied the highly correlated complex absorbing potential-equation-of-motion coupled cluster (CAP-EOMCC) approach which is a combination of CAP and EOMCC approach to calculate the lifetime of the states arising from 2p inner-shell ionization of an Ar atom and 3d inner-shell ionization of Kr atom. We have also calculated the lifetime of Ar{sup 2+}(2p{sup −1}3p{sup −1}) {sup 1}D, Ar{sup 2+}(2p{sup −1}3p{sup −1}) {sup 1}S, and Ar{sup 2+}(2p{sup −1}3s{sup −1}) {sup 1}P double ionized states. The predicted results are compared with the other theoretical results as well as experimental results available in the literature.

  10. WEAVE core processing system

    NASA Astrophysics Data System (ADS)

    Walton, Nicholas A.; Irwin, Mike; Lewis, James R.; Gonzalez-Solares, Eduardo; Dalton, Gavin; Trager, Scott; Aguerri, J. Alfonso L.; Allende Prieto, Carlos; Benn, Chris R.; Abrams, Don Carlos; Picó, Sergio; Middleton, Kevin; Lodi, Marcello; Bonifacio, Piercarlo

    2014-07-01

    WEAVE is an approved massive wide field multi-object optical spectrograph (MOS) currently entering its build phase, destined for use on the 4.2-m William Herschel Telescope (WHT). It will be commissioned and begin survey operations in 2017. This paper describes the core processing system (CPS) system being developed to process the bulk data flow from WEAVE. We describe the processes and techniques to be used in producing the scientifically validated 'Level 1' data products from the WEAVE data. CPS outputs will include calibrated one-d spectra and initial estimates of basic parameters such as radial velocities (for stars) and redshifts (for galaxies).

  11. Characterization of G2P[4] rotavirus strains causing outbreaks of gastroenteritis in the Northern Territory, Australia, in 1999, 2004 and 2009.

    PubMed

    Donato, Celeste M; Cowley, Daniel; Donker, Nicole C; Bogdanovic-Sakran, Nada; Snelling, Thomas L; Kirkwood, Carl D

    2014-12-01

    Outbreaks of rotavirus diarrhea cause a large disease burden in the Alice Springs region of the Northern Territory, Australia. The introduction of the rotavirus vaccine Rotarix® has been associated with an increase in detection of G2P[4] strains in many countries. However, G2P[4] emergence has also been observed in vaccine-naive countries, suggesting a general global increase in the circulation of G2P[4] strains. A G2P[4] rotavirus outbreak occurred in 2009, 28 months after the introduction of the Rotarix® vaccine and 43 children were hospitalized. Pre-vaccine introduction, G2P[4] strains were observed associated with large outbreaks in 1999 and 2004. To determine the genetic relationship between these strains whole genome sequence analysis was conducted on representative strains from each of the G2P[4] outbreaks, in 1999, 2004 and 2009. Phylogenetic analysis revealed the majority of genes from 2009 outbreak strain clustered with contemporary global strains, while the VP7 gene clustered with contemporary and older strains and was antigenically distinct to the majority of contemporary global G2P[4] strains; suggesting the strain was an intragenogroup reassortant. The 1999 and 2009 strains appear to share similar evolutionary origins, and both had a high degree of genetic identity to previously identified Australian and global strains. Conversely, the 2004 outbreak strain was more divergent in comparison to Australian and global strains. The 1999 and 2004 outbreaks likely occurred due to the accumulation of immunologically naïve children in the population following low levels of G2P[4] rotavirus disease in the community in the years prior to each outbreak. The 2009 outbreak was associated with moderate vaccine coverage in the population and vaccine efficacy against the strain was low. The circulation of this unusual strain in the population combined with low vaccine coverage and diminished vaccine efficacy likely contributed to the outbreak occurring in this

  12. Core and Off-Core Processes in Systems Engineering

    NASA Technical Reports Server (NTRS)

    Breidenthal, Julian; Forsberg, Kevin

    2010-01-01

    An emerging methodology of organizing systems-engineering plans is based on a concept of core and off-core processes or activities. This concept has emerged as a result of recognition of a risk in the traditional representation of systems-engineering plans by a Vee model alone, according to which a large system is decomposed into levels of smaller subsystems, then integrated through levels of increasing scope until the full system is constructed. Actual systems-engineering activity is more complicated, raising the possibility that the staff will become confused in the absence of plans which explain the nature and ordering of work beyond the traditional Vee model.

  13. Mechanisms of charge transport in anisotype n-TiO{sub 2}/p-CdTe heterojunctions

    SciTech Connect

    Brus, V. V.; Ilashchuk, M. I.; Kovalyuk, Z. D.; Maryanchuk, P. D.; Ulyanytsky, K. S.; Gritsyuk, B. N.

    2011-08-15

    Surface-barrier anisotype n-TiO{sub 2}/p-CdTe heterojunctions are fabricated by depositing thin titanium-dioxide films on a freshly cleaved surface of single-crystalline cadmium-telluride wafers by reactive magnetron sputtering. It is established that the electric current through the heterojunctions under investigation is formed by generation-recombination processes in the space-charge region via a deep energy level and tunneling through the potential barrier. The depth and nature of the impurity centers involved in the charge transport are determined.

  14. 2P/Encke, the Taurid complex NEOs and the Maribo and Sutter's Mill meteorites

    NASA Astrophysics Data System (ADS)

    Tubiana, C.; Snodgrass, C.; Michelsen, R.; Haack, H.; Böhnhardt, H.; Fitzsimmons, A.; Williams, I. P.

    2015-12-01

    Aims: 2P/Encke is a short period comet that was discovered in 1786 and has been extensively observed and studied for more than 200 years. The Taurid meteoroid stream has long been linked with 2P/Encke owing to a good match of their orbital elements, even though the comet's activity is not strong enough to explain the number of observed meteors. Various small near-Earth objects (NEOs) have been discovered with orbits that can be linked to 2P/Encke and the Taurid meteoroid stream. Maribo and Sutter's Mill are CM type carbonaceous chondrite that fell in Denmark on January 17, 2009 and April 22, 2012, respectively. Their pre-atmospheric orbits place them in the middle of the Taurid meteoroid stream, which raises the intriguing possibility that comet 2P/Encke could be the parent body of CM chondrites. Methods: To investigate whether a relationship between comet 2P/Encke, the Taurid complex associated NEOs, and CM chondrites exists, we performed photometric and spectroscopic studies of these objects in the visible wavelength range. We observed 2P/Encke and 10 NEOs on August 2, 2011 with the FORS instrument at the 8.2 m Very Large Telescope on Cerro Paranal (Chile). Results: Images in the R filter, used to investigate the possible presence of cometary activity around the nucleus of 2P/Encke and the NEOs, show that no resolved coma is present. None of the FORS spectra show the 700 nm absorption feature due to hydrated minerals that is seen in the CM chondrite meteorites. All objects show featureless spectra with moderate reddening slopes at λ< 800 nm. Apart for 2003 QC10 and 1999 VT25, which show a flatter spectrum, the spectral slope of the observed NEOs is compatible with that of 2P/Encke. However, most of the NEOs show evidence of a silicate absorption in lower S/N data at λ> 800 nm, which is not seen in 2P/Encke, which suggests that they are not related. Conclusions: Despite similar orbits, we find no spectroscopic evidence for a link between 2P/Encke, the Taurid

  15. P2P-based botnets: structural analysis, monitoring, and mitigation

    SciTech Connect

    Yan, Guanhua; Eidenbenz, Stephan; Ha, Duc T; Ngo, Hung Q

    2008-01-01

    Botnets, which are networks of compromised machines that are controlled by one or a group of attackers, have emerged as one of the most serious security threats on the Internet. With an army of bots at the scale of tens of thousands of hosts or even as large as 1.5 million PCs, the computational power of botnets can be leveraged to launch large-scale DDoS (Distributed Denial of Service) attacks, sending spamming emails, stealing identities and financial information, etc. As detection and mitigation techniques against botnets have been stepped up in recent years, attackers are also constantly improving their strategies to operate these botnets. The first generation of botnets typically employ IRC (Internet Relay Chat) channels as their command and control (C&C) centers. Though simple and easy to deploy, the centralized C&C mechanism of such botnets has made them prone to being detected and disabled. Against this backdrop, peer-to-peer (P2P) based botnets have emerged as a new generation of botnets which can conceal their C&C communication. Recently, P2P networks have emerged as a covert communication platform for malicious programs known as bots. As popular distributed systems, they allow bots to communicate easily while protecting the botmaster from being discovered. Existing work on P2P-based hotnets mainly focuses on measurement of botnet sizes. In this work, through simulation, we study extensively the structure of P2P networks running Kademlia, one of a few widely used P2P protocols in practice. Our simulation testbed incorporates the actual code of a real Kademlia client software to achieve great realism, and distributed event-driven simulation techniques to achieve high scalability. Using this testbed, we analyze the scaling, reachability, clustering, and centrality properties of P2P-based botnets from a graph-theoretical perspective. We further demonstrate experimentally and theoretically that monitoring bot activities in a P2P network is difficult

  16. Core-core and core-valence correlation

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1988-01-01

    The effect of (1s) core correlation on properties and energy separations was analyzed using full configuration-interaction (FCI) calculations. The Be 1 S - 1 P, the C 3 P - 5 S and CH+ 1 Sigma + or - 1 Pi separations, and CH+ spectroscopic constants, dipole moment and 1 Sigma + - 1 Pi transition dipole moment were studied. The results of the FCI calculations are compared to those obtained using approximate methods. In addition, the generation of atomic natural orbital (ANO) basis sets, as a method for contracting a primitive basis set for both valence and core correlation, is discussed. When both core-core and core-valence correlation are included in the calculation, no suitable truncated CI approach consistently reproduces the FCI, and contraction of the basis set is very difficult. If the (nearly constant) core-core correlation is eliminated, and only the core-valence correlation is included, CASSCF/MRCI approached reproduce the FCI results and basis set contraction is significantly easier.

  17. EuCo2P2 : A model molecular-field helical Heisenberg antiferromagnet

    NASA Astrophysics Data System (ADS)

    Sangeetha, N. S.; Cuervo-Reyes, Eduardo; Pandey, Abhishek; Johnston, D. C.

    2016-07-01

    The metallic compound EuCo2P2 with the body-centered tetragonal ThCr2Si2 structure containing Eu spins-7/2 was previously shown from single-crystal neutron diffraction measurements to exhibit a helical antiferromagnetic (AFM) structure below TN=66.5 K with the helix axis along the c axis and with the ordered moments aligned within the a b plane. Here we report crystallography, electrical resistivity, heat capacity, magnetization, and magnetic susceptibility measurements on single crystals of this compound. We demonstrate that EuCo2P2 is a model molecular-field helical Heisenberg antiferromagnet from comparisons of the anisotropic magnetic susceptibility χ , high-field magnetization, and magnetic heat capacity of EuCo2P2 single crystals at temperature T ≤TN with the predictions of our recent formulation of molecular-field theory. Values of the Heisenberg exchange interactions between the Eu spins are derived from the data. The low-T magnetic heat capacity ˜T3 arising from spin-wave excitations with no anisotropy gap is calculated and found to be comparable to the lattice heat capacity. The density of states at the Fermi energy of EuCo2P2 and the related compound BaCo2P2 are found from the heat capacity data to be large, 10 and 16 states/eV per formula unit for EuCo2P2 and BaCo2P2 , respectively. These values are enhanced by a factor of ˜2.5 above those found from DFT electronic structure calculations for the two compounds. The calculations also find ferromagnetic Eu-Eu exchange interactions within the a b plane and AFM interactions between Eu spins in nearest- and next-nearest planes, in agreement with the MFT analysis of χa b(T ≤TN) .

  18. EuCo2P2: A Model Molecular-Field Helical Heisenberg Antiferromagnet

    DOE PAGES

    Sangeetha, N. S.; Cuervo-Reyes, Eduardo; Pandey, Abhishek; Johnston, D. C.

    2016-07-19

    The metallic compound EuCo2P2 with the body-centered tetragonal ThCr2Si2 structure containing Eu spins-7/2 was previously shown from single-crystal neutron diffraction measurements to exhibit a helical antiferromagnetic (AFM) structure below TN=66.5 K with the helix axis along the c axis and with the ordered moments aligned within the ab plane. Here we report crystallography, electrical resistivity, heat capacity, magnetization, and magnetic susceptibility measurements on single crystals of this compound. We demonstrate that EuCo2P2 is a model molecular-field helical Heisenberg antiferromagnet from comparisons of the anisotropic magnetic susceptibility χ, high-field magnetization, and magnetic heat capacity of EuCo2P2 single crystals at temperature T≤TNmore » with the predictions of our recent formulation of molecular-field theory. Values of the Heisenberg exchange interactions between the Eu spins are derived from the data. The low-T magnetic heat capacity ~T3 arising from spin-wave excitations with no anisotropy gap is calculated and found to be comparable to the lattice heat capacity. The density of states at the Fermi energy of EuCo2P2 and the related compound BaCo2P2 are found from the heat capacity data to be large, 10 and 16 states/eV per formula unit for EuCo2P2 and BaCo2P2, respectively. These values are enhanced by a factor of ~2.5 above those found from DFT electronic structure calculations for the two compounds. Additionally, the calculations also find ferromagnetic Eu–Eu exchange interactions within the ab plane and AFM interactions between Eu spins in nearest- and next-nearest planes, in agreement with the MFT analysis of χab(T≤TN).« less

  19. EuCo2P2: A model molecular-field helical Heisenberg antiferromagnet

    DOE PAGES

    Sangeetha, N. S.; Cuervo-Reyes, Eduardo; Pandey, Abhishek; Johnston, D. C.

    2016-07-19

    Here, the metallic compound EuCo2P2 with the body-centered tetragonal ThCr2Si2 structure containing Eu spins-7/2 was previously shown from single-crystal neutron diffraction measurements to exhibit a helical antiferromagnetic (AFM) structure below TN=66.5 K with the helix axis along the c axis and with the ordered moments aligned within the ab plane. Here we report crystallography, electrical resistivity, heat capacity, magnetization, and magnetic susceptibility measurements on single crystals of this compound. We demonstrate that EuCo2P2 is a model molecular-field helical Heisenberg antiferromagnet from comparisons of the anisotropic magnetic susceptibility χ, high-field magnetization, and magnetic heat capacity of EuCo2P2 single crystals at temperaturemore » T ≤ TN with the predictions of our recent formulation of molecular-field theory. Values of the Heisenberg exchange interactions between the Eu spins are derived from the data. The low-T magnetic heat capacity ~T3 arising from spin-wave excitations with no anisotropy gap is calculated and found to be comparable to the lattice heat capacity. The density of states at the Fermi energy of EuCo2P2 and the related compound BaCo2P2 are found from the heat capacity data to be large, 10 and 16 states/eV per formula unit for EuCo2P2 and BaCo2P2, respectively. These values are enhanced by a factor of ~2.5 above those found from DFT electronic structure calculations for the two compounds. The calculations also find ferromagnetic Eu–Eu exchange interactions within the ab plane and AFM interactions between Eu spins in nearest- and next-nearest planes, in agreement with the MFT analysis of χab(T ≤ TN).« less

  20. IMP2/p62 induces genomic instability and an aggressive hepatocellular carcinoma phenotype.

    PubMed

    Kessler, S M; Laggai, S; Barghash, A; Schultheiss, C S; Lederer, E; Artl, M; Helms, V; Haybaeck, J; Kiemer, A K

    2015-01-01

    Hepatocellular carcinoma (HCC) represents the third leading cause of cancer-related deaths and commonly develops in inflammatory environments. The IGF2 mRNA-binding protein IMP2-2/IGF2BP2-2/p62 was originally identified as an autoantigen in HCC. Aim of this study was to investigate a potential pathophysiological role of p62 in hepatocarcinogenesis. Human HCC tissue showed overexpression of IMP2, which strongly correlated with the fetal markers AFP and DLK1/Pref-1/FA-1 and was particularly elevated in tumors with stem-like features and hypervascularization. Molecular classification of IMP2-overexpressing tumors revealed an aggressive phenotype. Livers of mice overexpressing the IMP2 splice variant p62 highly expressed the stem cell marker DLK1 and secreted DLK1 into the blood. p62 was oncogenic: diethylnitrosamine (DEN)-treated p62 transgenic mice exhibited a higher tumor incidence and multiplicity than wild types. Tumors of transgenics showed a more aggressive and stem-like phenotype and displayed more oncogenic chromosomal aberrations determined with aCGH analysis. DEN-treated p62 transgenic mice exhibited distinct signs of inflammation, such as inflammatory cytokine expression and oxidative stress markers, that is, thiobarbituric acid-reactive substance (TBARS) levels. Reactive oxygen species (ROS) production was elevated in HepG2 cells, which either overexpressed p62 or were treated with DLK1. p62 induced this ROS production by a DLK1-dependent induction and activation of the small Rho-GTPase RAC1, activating NADPH oxidase and being overexpressed in human HCC. Our data indicate that p62/IMP2 promotes hepatocarcinogenesis by an amplification of inflammation. PMID:26426686

  1. IMP2/p62 induces genomic instability and an aggressive hepatocellular carcinoma phenotype

    PubMed Central

    Kessler, S M; Laggai, S; Barghash, A; Schultheiss, C S; Lederer, E; Artl, M; Helms, V; Haybaeck, J; Kiemer, A K

    2015-01-01

    Hepatocellular carcinoma (HCC) represents the third leading cause of cancer-related deaths and commonly develops in inflammatory environments. The IGF2 mRNA-binding protein IMP2-2/IGF2BP2-2/p62 was originally identified as an autoantigen in HCC. Aim of this study was to investigate a potential pathophysiological role of p62 in hepatocarcinogenesis. Human HCC tissue showed overexpression of IMP2, which strongly correlated with the fetal markers AFP and DLK1/Pref-1/FA-1 and was particularly elevated in tumors with stem-like features and hypervascularization. Molecular classification of IMP2-overexpressing tumors revealed an aggressive phenotype. Livers of mice overexpressing the IMP2 splice variant p62 highly expressed the stem cell marker DLK1 and secreted DLK1 into the blood. p62 was oncogenic: diethylnitrosamine (DEN)-treated p62 transgenic mice exhibited a higher tumor incidence and multiplicity than wild types. Tumors of transgenics showed a more aggressive and stem-like phenotype and displayed more oncogenic chromosomal aberrations determined with aCGH analysis. DEN-treated p62 transgenic mice exhibited distinct signs of inflammation, such as inflammatory cytokine expression and oxidative stress markers, that is, thiobarbituric acid-reactive substance (TBARS) levels. Reactive oxygen species (ROS) production was elevated in HepG2 cells, which either overexpressed p62 or were treated with DLK1. p62 induced this ROS production by a DLK1-dependent induction and activation of the small Rho-GTPase RAC1, activating NADPH oxidase and being overexpressed in human HCC. Our data indicate that p62/IMP2 promotes hepatocarcinogenesis by an amplification of inflammation. PMID:26426686

  2. Activation of protein kinase C-mitogen-activated protein kinase signaling in response to inositol starvation triggers Sir2p-dependent telomeric silencing in yeast.

    PubMed

    Lee, Sojin; Gaspar, Maria L; Aregullin, Manuel A; Jesch, Stephen A; Henry, Susan A

    2013-09-27

    Depriving wild type yeast of inositol, a soluble precursor for phospholipid, phosphoinositide, and complex sphingolipid synthesis, activates the protein kinase C (PKC)-MAPK signaling pathway, which plays a key role in the activation of NAD(+)-dependent telomeric silencing. We now report that triggering PKC-MAPK signaling by inositol deprivation or by blocking inositol-containing sphingolipid synthesis with aureobasidin A results in increased telomeric silencing regulated by the MAPK, Slt2p, and the NAD(+)-dependent deacetylase, Sir2p. Consistent with the dependence on NAD(+) in Sir2p-regulated silencing, we found that inositol depletion induces the expression of BNA2, which is required for the de novo synthesis of NAD(+). Moreover, telomeric silencing is greatly reduced in bna2Δ and npt1Δ mutants, which are defective in de novo and salvage pathways for NAD(+) synthesis, respectively. Surprisingly, however, omitting nicotinic acid from the growth medium, which reduces cellular NAD(+) levels, leads to increased telomeric silencing in the absence of inositol and/or at high temperature. This increase in telomeric silencing in response to inositol starvation is correlated to chronological life span extension but is Sir2p-independent. We conclude that activation of the PKC-MAPK signaling by interruption of inositol sphingolipid synthesis leads to increased Sir2p-dependent silencing and is dependent upon the de novo and salvage pathways for NAD(+) synthesis but is not correlated with cellular NAD(+) levels.

  3. Raman spectroscopic study of (Ph 2P) 2CCH 2 and [(Ph 2P) 2CCH 2]W(CO) 4

    NASA Astrophysics Data System (ADS)

    Fickert, C.; Posset, U.; Kiefer, W.

    1997-06-01

    The Raman and IR spectra of 1,1-bis[diphenylphosphino]ethene (Ph 2P) 2CCH 2 (vdpp) and the tetracarbonyl tungsten complex (vdpp)W(CO) 4 have been recorded. Vibrational assignments are proposed based on local symmetry considerations. For the vinylidene stretching mode a coordination shift is observed from 1588 cm -1 in polycrystalline vdpp to 1581 cm -1 in its tetracarbonyl tungsten complex. From a comparison of the v(CO) splitting pattern with those of related complexes monoclinic structure with factor group C2h and four formula units per unit cell is concluded.

  4. Synthesis, characterization and photocatalytic performance of PbS/Ni2P flowers

    NASA Astrophysics Data System (ADS)

    Liu, Shuling; Han, Lefang; Liu, Hui

    2016-11-01

    Flower-like PbS/Ni2P composites were synthesized by a facile two-step chemical route. The morphology and structure of the resulting composites were investigated by SEM and TEM images and XRD spectra, respectively. The results showed that the as-obtained composites were composed of the cubic PbS flowers and hexagonal Ni2P nanoparticles, and Ni2P nanoparticles coated on the surfaces of flower-like PbS microstructure. It was found that changing the molar ratio to 3:1, flower-like PbS/Ni2P composites have been successfully synthesized by using cationic cetyltrimethylammonium bromide(CTAB) and anionic sodium dodecyl sulfate (SDS) as template. Furthermore, using methylene blue(MB) as a model organic pollutant, the photocatalytic degradation experiments indicated that the as-prepared composites showed enhanced photocatalytic degradation activity for methylene blue(75%) which is as higher as that of the only flower-like PbS (16.6%) and only Ni2P nanoparticles (44.8%) at the same time. This work may be expected to find its potential application in water pollution treatment.

  5. Large-Scale Mini-Magnetosphere Plasma Propulsion (M2P2) Experiments

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.; Slough, J.; Ziemba, T.; Euripides, P.; Adrian, M. L.; Gallagher, D.; Craven, P.; Tomlinson, W.; Cravens, J.; Burch, J.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Mini-Magnetosphere Plasma Propulsion (M2P2) is an innovative plasma propulsion system that has the potential to propel spacecraft at unprecedented speeds of 50 to 80 km per second with a low-power requirement of approx. 1 kW per 100 kg of payload and approx. 1 kg of neutral gas [fuel] consumption per day of acceleration. Acceleration periods from several days to a few months are envisioned. High specific impulse and efficiency are achieved through coupling of the spacecraft to the 400 km per second solar wind through an artificial magnetosphere. The mini-magnetosphere or inflated magnetic bubble is produced by the injection of cold dense plasma into a spacecraft-generated magnetic field envelope. Magnetic bubble inflation is driven by electromagnetic processes thereby avoiding the material and deployment problems faced by mechanical solar sail designs, Here, we present the theoretical design of M2P2 as well as initial results from experimental testing of an M2P2 prototype demonstrating: 1) inflation of the dipole magnetic field geometry through the internal injection of cold plasma; and 2) deflection of and artificial solar wind by the prototype M2P2 system. In addition, we present plans for direct laboratory measurement of thrust imparted to a prototype M2P2 by an artificial solar wind during the summer of 2001.

  6. Large-Scale Mini-Magnetosphere Plasma Propulsion (M2P2) Experiments

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.; Slough, J.; Ziemba, T.; Euripides, P.; Gallagher, D.; Craven, P.; Adrian, M. L.; Tomlinson, W.; Cravens, J.; Burch, J.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Mini-Magnetosphere Plasma Propulsion (M2P2) is an innovative plasma propulsion system that has the potential to propel spacecraft at unprecedented speeds of 50 to 80 km/s, with a low power requirement of approx. 1 kW per 100 kg of payload and -1 kg of neutral gas [fuel] consumption per day of acceleration. Acceleration periods from several days to a few months are envisioned. High specific impulse and efficiency are achieved through coupling of the spacecraft to the 400 km/s. solar wind through an artificial magnetosphere. The mini-magnetosphere or inflated magnetic bubble is produced by the injection of cold dense plasma into a spacecraft-generated magnetic field envelope. Magnetic bubble inflation is driven by electromagnetic processes thereby avoiding the material and deployment problems faced by mechanical solar sail designs. Here, we present the theoretical design of M2P2 as well as initial results from experimental testing of an M2P2 prototype demonstrating: 1) inflation of the dipole magnetic field geometry through the internal injection of cold plasma; and 2) deflection of and artificial solar wind by the prototype M2P2 system. In addition, we present plans for direct laboratory measurement of thrust imparted to a prototype M2P2 by an artificial solar wind during the summer of 2001.

  7. A Non-canonical Voltage-Sensing Mechanism Controls Gating in K2P K+ Channels

    PubMed Central

    Schewe, Marcus; Nematian-Ardestani, Ehsan; Sun, Han; Musinszki, Marianne; Cordeiro, Sönke; Bucci, Giovanna; de Groot, Bert L.; Tucker, Stephen J.; Rapedius, Markus; Baukrowitz, Thomas

    2016-01-01

    Summary Two-pore domain (K2P) K+ channels are major regulators of excitability that endow cells with an outwardly rectifying background “leak” conductance. In some K2P channels, strong voltage-dependent activation has been observed, but the mechanism remains unresolved because they lack a canonical voltage-sensing domain. Here, we show voltage-dependent gating is common to most K2P channels and that this voltage sensitivity originates from the movement of three to four ions into the high electric field of an inactive selectivity filter. Overall, this ion-flux gating mechanism generates a one-way “check valve” within the filter because outward movement of K+ induces filter opening, whereas inward movement promotes inactivation. Furthermore, many physiological stimuli switch off this flux gating mode to convert K2P channels into a leak conductance. These findings provide insight into the functional plasticity of a K+-selective filter and also refine our understanding of K2P channels and the mechanisms by which ion channels can sense voltage. PMID:26919430

  8. Is the X (3915 ) the χc 0(2 P )?

    NASA Astrophysics Data System (ADS)

    Olsen, Stephen Lars

    2015-03-01

    The Particle Data Group Meson Summary Table lists the X (3915 ) meson, an ω J /ψ mass peak seen in B →K ω J /ψ decays and γ γ →ω J /ψ two-photon fusion reactions, as the χc 0(2 P ), the 23P0 charmonium state. Here, with some reasonable assumptions, it is shown that if the X (3915 ) is the χc 0(2 P ), the measured strength of the γ γ →X (3915 ) signal implies an upper limit on the branching fraction B (χc 0(2 P )→ω J /ψ ) that is below a lower limit inferred for the same quantity from the B →K X (3915 ) decay rate. Also, the absence any signal for X (3915 )→D0D¯0 in B+→K+D0D¯0 decays is used to infer the limit B (X (3915 )→D0D¯0)<1.2 ×B (X (3915 )→ω J /ψ ). This contradicts expectations that χc 0(2 P ) decays to D0D¯0 should be a dominant process, while decays to ω J /ψ , which are Okubo-Zweig-Iizuka suppressed, should be relatively rare. These, plus reasons given earlier by Guo and Meissner, raise concerns about the X (3915 )=χc 0(2 P ) assignment.

  9. Secure mobile agent for telemedicine based on P2P networks.

    PubMed

    Hsu, Wen-Shin; Pan, Jiann-I

    2013-06-01

    Exploring intelligent mobile agent (MA) technology for assisting medical services or transmitting personal patient-health information in telemedicine applications has been widely investigated. Conversely, peer-to-peer (P2P) networking has become one of the most popular applications used in the Internet because of its benefits for easy-to-manage resources and because it balances workloads. Therefore, constructing an agent-based telemedicine platform based on P2P networking architecture is necessary. The main purpose of this paper is to construct a safe agent-based telemedicine that based on P2P networking architecture. Two themes are addressed in this paper: (a) the P2P network architecture for an agent-based telemedicine service, and (b) the security mechanisms for the proposed telemedicine networking architecture. When an MA contains patient information and migrates from one host to another through the Internet, it can be attacked by other software agents or agent platforms that can illegally access patient information. The proposed P2P network architecture is based on the JXTA protocol and provides two types of telemedicine service models: the predictable service model and unpredictable service model. This architecture employs a two-layer safety mechanism for MAs (i.e., time-limited black boxes and RSA undetachable signature technologies), to provide a secure solution for agent-based telemedicine services. PMID:23605144

  10. Saccharomyces cerevisiae phospholipase C regulates transcription of Msn2p-dependent stress-responsive genes.

    PubMed

    Demczuk, Agnieszka; Guha, Nilanjan; Nguyen, Peter H; Desai, Parima; Chang, Jennifer; Guzinska, Katarzyna; Rollins, Janet; Ghosh, Chandra C; Goodwin, Leslie; Vancura, Ales

    2008-06-01

    Phosphatidylinositol phosphates are involved in signal transduction, cytoskeletal organization, and membrane trafficking. Inositol polyphosphates, produced from phosphatidylinositol phosphates by the phospholipase C-dependent pathway, regulate chromatin remodeling. We used genome-wide expression analysis to further investigate the roles of Plc1p (phosphoinositide-specific phospholipase C in Saccharomyces cerevisiae) and inositol polyphosphates in transcriptional regulation. Plc1p contributes to the regulation of approximately 2% of yeast genes in cells grown in rich medium. Most of these genes are induced by nutrient limitation and other environmental stresses and are derepressed in plc1 Delta cells. Surprisingly, genes regulated by Plc1p do not correlate with gene sets regulated by Swi/Snf or RSC chromatin remodeling complexes but show correlation with genes controlled by Msn2p. Our results suggest that the increased expression of stress-responsive genes in plc1 Delta cells is mediated by decreased cyclic AMP synthesis and protein kinase A (PKA)-mediated phosphorylation of Msn2p and increased binding of Msn2p to stress-responsive promoters. Accordingly, plc1 Delta cells display other phenotypes characteristic of cells with decreased PKA activity. Our results are consistent with a model in which Plc1p acts together with the membrane receptor Gpr1p and associated G(alpha) protein Gpa2p in a pathway separate from Ras1p/Ras2p and converging on PKA.

  11. The Clathrin Adaptor Gga2p Is a Phosphatidylinositol 4-phosphate Effector at the Golgi Exit

    PubMed Central

    Demmel, Lars; Gravert, Maike; Ercan, Ebru; Habermann, Bianca; Müller-Reichert, Thomas; Kukhtina, Viktoria; Haucke, Volker; Baust, Thorsten; Sohrmann, Marc; Kalaidzidis, Yannis; Klose, Christian; Beck, Mike; Peter, Matthias

    2008-01-01

    Phosphatidylinositol 4-phosphate (PI(4)P) is a key regulator of membrane transport required for the formation of transport carriers from the trans-Golgi network (TGN). The molecular mechanisms of PI(4)P signaling in this process are still poorly understood. In a search for PI(4)P effector molecules, we performed a screen for synthetic lethals in a background of reduced PI(4)P and found the gene GGA2. Our analysis uncovered a PI(4)P-dependent recruitment of the clathrin adaptor Gga2p to the TGN during Golgi-to-endosome trafficking. Gga2p recruitment to liposomes is stimulated both by PI(4)P and the small GTPase Arf1p in its active conformation, implicating these two molecules in the recruitment of Gga2p to the TGN, which ultimately controls the formation of clathrin-coated vesicles. PI(4)P binding occurs through a phosphoinositide-binding signature within the N-terminal VHS domain of Gga2p resembling a motif found in other clathrin interacting proteins. These data provide an explanation for the TGN-specific membrane recruitment of Gga2p. PMID:18287542

  12. A hybrid CDN-P2P system for Earth observation data delivery

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Li, Bin; Gong, Jianya; Guo, Wei

    2008-12-01

    This paper presents a P2P approach to the delivery of earth-observation data. Conventional P2P networks can speed up data delivery but suffers the problem of stability when handling spatial data. We design a hybrid CDN-P2P strategy to speed up data delivery while maintaining stability. We tested our strategy in a simulation environment in which performance of data transfer is observed against different bandwidths. The results show that the hybrid approach performs much better than the conventional only-server and only-peers model. Dynamic allocation of peers and predownload are also presented as strategies to address the special needs of spatial data delivery.

  13. Kinetic-arrest-induced phase coexistence and metastability in (Mn,Fe ) 2(P ,Si )

    NASA Astrophysics Data System (ADS)

    Miao, X. F.; Mitsui, Y.; Dugulan, A. Iulian; Caron, L.; Thang, N. V.; Manuel, P.; Koyama, K.; Takahashi, K.; van Dijk, N. H.; Brück, E.

    2016-09-01

    Neutron diffraction, Mössbauer spectroscopy, magnetometry, and in-field x-ray diffraction are employed to investigate the magnetoelastic phase transition in hexagonal (Mn,Fe ) 2(P ,Si ) compounds. (Mn,Fe ) 2(P ,Si ) compounds undergo for certain compositions a second-order paramagnetic (PM) to a spin-density-wave (SDW) phase transition before further transforming into a ferromagnetic (FM) phase via a first-order phase transition. The SDW-FM transition can be kinetically arrested, causing the coexistence of FM and untransformed SDW phases at low temperatures. Our in-field x-ray diffraction and magnetic relaxation measurements clearly reveal the metastability of the untransformed SDW phase. This unusual magnetic configuration originates from the strong magnetoelastic coupling and the mixed magnetism in hexagonal (Mn,Fe ) 2(P ,Si ) compounds.

  14. A resources monitoring architecture for P2P file-sharing systems

    NASA Astrophysics Data System (ADS)

    Wang, Wenxian; Chen, Xingshu; Wang, Haizhou

    2013-07-01

    Resources monitoring is an important problem of the overall efficient usage and control of P2P file-sharing systems. The resources of file-sharing systems can include all distributing servers, programs and peers. Several researches have tried to address this issue, but most of them illuminated P2P traffic characterization, identification and user behavior. Based on previous work, we present a resources monitoring architecture for P2P file-sharing systems. The monitoring architecture employs a hierarchical structure and provides systemic monitoring including resources discovery, relative information extraction and analysis, trace and location. It gives a systematic framework for file-sharing resources monitoring. And a prototype system has been developed based on the framework.

  15. The N2-P3 complex of the evoked potential and human performance

    NASA Technical Reports Server (NTRS)

    Odonnell, Brian F.; Cohen, Ronald A.

    1988-01-01

    The N2-P3 complex and other endogenous components of human evoked potential provide a set of tools for the investigation of human perceptual and cognitive processes. These multidimensional measures of central nervous system bioelectrical activity respond to a variety of environmental and internal factors which have been experimentally characterized. Their application to the analysis of human performance in naturalistic task environments is just beginning. Converging evidence suggests that the N2-P3 complex reflects processes of stimulus evaluation, perceptual resource allocation, and decision making that proceed in parallel, rather than in series, with response generation. Utilization of these EP components may provide insights into the central nervous system mechanisms modulating task performance unavailable from behavioral measures alone. The sensitivity of the N2-P3 complex to neuropathology, psychopathology, and pharmacological manipulation suggests that these components might provide sensitive markers for the effects of environmental stressors on the human central nervous system.

  16. Atomic resolution crystal structure of Sapp2p, a secreted aspartic protease from Candida parapsilosis.

    PubMed

    Dostál, Jiří; Pecina, Adam; Hrušková-Heidingsfeldová, Olga; Marečková, Lucie; Pichová, Iva; Řezáčová, Pavlina; Lepšík, Martin; Brynda, Jiří

    2015-12-01

    The virulence of the Candida pathogens is enhanced by the production of secreted aspartic proteases, which therefore represent possible targets for drug design. Here, the crystal structure of the secreted aspartic protease Sapp2p from Candida parapsilosis was determined. Sapp2p was isolated from its natural source and crystallized in complex with pepstatin A, a classical aspartic protease inhibitor. The atomic resolution of 0.83 Å allowed the protonation states of the active-site residues to be inferred. A detailed comparison of the structure of Sapp2p with the structure of Sapp1p, the most abundant C. parapsilosis secreted aspartic protease, was performed. The analysis, which included advanced quantum-chemical interaction-energy calculations, uncovered molecular details that allowed the experimentally observed equipotent inhibition of both isoenzymes by pepstatin A to be rationalized.

  17. Atypical features of a Ure2p glutathione transferase from Phanerochaete chrysosporium.

    PubMed

    Thuillier, Anne; Roret, Thomas; Favier, Frédérique; Gelhaye, Eric; Jacquot, Jean-Pierre; Didierjean, Claude; Morel-Rouhier, Mélanie

    2013-07-11

    Glutathione transferases (GSTs) are known to transfer glutathione onto small hydrophobic molecules in detoxification reactions. The GST Ure2pB1 from Phanerochaete chrysosporium exhibits atypical features, i.e. the presence of two glutathione binding sites and a high affinity towards oxidized glutathione. Moreover, PcUre2pB1 is able to efficiently deglutathionylate GS-phenacylacetophenone. Catalysis is not mediated by the cysteines of the protein but rather by the one of glutathione and an asparagine residue plays a key role in glutathione stabilization. Interestingly PcUre2pB1 interacts in vitro with a GST of the omega class. These properties are discussed in the physiological context of wood degrading fungi.

  18. Galactomannan Downregulates the Inflammation Responses in Human Macrophages via NFκB2/p100

    PubMed Central

    Toledano, Víctor; Hernández-Jiménez, Enrique; Cubillos-Zapata, Carolina; Flandez, Marta; Álvarez, Enrique; Varela-Serrano, Aníbal; Cantero, Ramón; Valles, Gema; García-Rio, Francisco; López-Collazo, Eduardo

    2015-01-01

    We show that galactomannan, a polysaccharide consisting of a mannose backbone with galactose side groups present on the cell wall of several fungi, induces a reprogramming of the inflammatory response in human macrophages through dectin-1 receptor. The nuclear factor kappa-light-chain-enhancer of activated B cells 2 (NFκB2)/p100 was overexpressed after galactomannan challenge. Knocking down NFκB2/p100 using small interfering RNA (siRNA) indicated that NFκB2/p100 expression is a crucial factor in the progression of the galactomannan-induced refractoriness. The data presented in this study could be used as a modulator of inflammatory response in clinical situations where refractory state is required. PMID:26441484

  19. High-pressure elastic properties of cubic Ir2P from ab initio calculations

    NASA Astrophysics Data System (ADS)

    Sun, Xiao-Wei; Bioud, Nadhira; Fu, Zhi-Jian; Wei, Xiao-Ping; Song, Ting; Li, Zheng-Wei

    2016-10-01

    A study of the high-pressure elastic properties of new synthetic Ir2P in the anti-fluorite structure is conducted using ab initio calculations based on density functional theory. The elastic constants C11, C12 and C44 for the cubic Ir2P are obtained by the stress-strain method and the elastic stability calculations under pressure indicate that it is stable at least 100 GPa. Additionally, the electronic density of states, the aggregate elastic moduli, that is bulk modulus, shear modulus, and Young's modulus along with the Debye temperature, Poisson's ratio, and elastic anisotropy factor are all successfully obtained. Moreover, the pressure dependence of the longitudinal and shear wave velocities in three different directions [100], [110], and [111] for Ir2P are also predicted for the first time.

  20. EVALUATING POLLUTION PREVENTION PROGRESS (P2P) III: AN ENVIRONMENTAL TOOL FOR SCREENING IN PRODUCT LIFE CYCLE ASSESSMENT AND CHEMICAL PROCESS DESIGN

    EPA Science Inventory

    P2P is a computer-based tool that supports the comparison of process and product alternatives in terms of environmental impacts. This tool provides screening-level information for use in process design and in product LCA. Twenty one impact categories and data for approximately ...

  1. The -5 A/G single-nucleotide polymorphism in the core promoter region of MT2A and its effect on allele-specific gene expression and Cd, Zn and Cu levels in laryngeal cancer.

    PubMed

    Starska, Katarzyna; Krześlak, Anna; Forma, Ewa; Olszewski, Jurek; Morawiec-Sztandera, Alina; Aleksandrowicz, Paweł; Lewy-Trenda, Iwona; Bryś, Magdalena

    2014-10-15

    Metallothioneins (MTs) are low molecular weight, cysteine-rich heavy metal-binding proteins which participate in the mechanisms of Zn homeostasis, and protect against toxic metals. MTs contain metal-thiolate cluster groups and suppress metal toxicity by binding to them. The aim of this study was to determine the -5 A/G (rs28366003) single-nucleotide polymorphism (SNP) in the core promoter region of the MT2A gene and to investigate its effect on allele-specific gene expression and Cd, Zn and Cu content in squamous cell laryngeal cancer (SCC) and non-cancerous laryngeal mucosa (NCM) as a control. The MT2A promoter region -5 A/G SNP was determined by restriction fragment length polymorphism using 323 SCC and 116 NCM. MT2A gene analysis was performed by quantitative real-time PCR. The frequency of A allele carriage was 94.2% and 91.8% in SCC and NCM, respectively, while G allele carriage was detected in 5.8% and 8.2% of SCC and NCM samples, respectively. As a result, a significant association was identified between the -5 A/G SNP in the MT2A gene with mRNA expression in both groups. Metal levels were analyzed by flame atomic absorption spectrometry. The significant differences were identified between A/A and both the A/G and G/G genotypes, with regard to the concentration of the contaminating metal. The Spearman rank correlation results showed that the MT2A expression and Cd, Zn, Cu levels were negatively correlated. Results obtained in this study suggest that -5 A/G SNP in MT2A gene may have an effect on allele-specific gene expression and accumulation of metal levels in laryngeal cancer.

  2. Evolution of superconductivity and magnetism in La1-xYbxRu2P2

    NASA Astrophysics Data System (ADS)

    Roncaioli, Connor; Hodovanets, Halyna; Saha, Shanta; Paglione, Johnpierre

    LaRu2P2, with a 4.1 K transition, is the first known pnictide-based superconductor. Sharing structural and electronic elements similar to those of the unconventional Fe-pnictide superconductors, it is of interest to investigate the parameter space in which a superconducting ground state survives. We present preliminary indications of more interesting magnetic behavior and structural tuning behavior when paramagnetic Yb is substituted for La in La1-xYbxRu2P2, and investigate potential heavy fermion behavior in the Yb end-member of this series.

  3. Transfer to the continuum calculations of quasifree (p,pn) and (p,2p) reactions

    NASA Astrophysics Data System (ADS)

    Gomez-Ramos, M.; Moro, A. M.

    2016-05-01

    Nucleon removal (p, pn) and (p, 2p) reactions at intermediate energies have gained renewed attention in recent years as a tool to extract information from exotic nuclei. The information obtained from these experiments is expected to be sensitive to deeper portions of the wave function of the removed nucleon than knockout reactions with heavier targets. In this contribution, we present calculations for (p, 2p) and (p, pn) reactions performed within the so-called transfer to the continuum method (TR*). Results for stable and unstable nuclei are presented, and compared with experimental data, when available.

  4. Design and implementation of telemetry seismic data acquisition system based on embedded P2P Ethernet

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Lin, J.; Chen, Z.

    2011-12-01

    A new design of telemetry seismic data acquisition system is presented which uses embedded, point to point (P2P) Ethernet networks. In our presentation, we explain the idea and motivation behind the use of P2P Ethernet topology and show the problems when such topology is used in seismic acquisition system. The presented paper focuses on the network protocols developed by us which include the generation of route table and dynamic IP address management. This new design has been implemented based on ARM and FPGA, which we have tested in laboratory and seismic exploration.

  5. Quantum electrodynamics corrections to the 2P fine splitting in Li.

    PubMed

    Puchalski, Mariusz; Pachucki, Krzysztof

    2014-08-15

    We consider quantum electrodynamics (QED) corrections to the fine splitting E(2P_{3/2})-E(2P_{1/2}) in the Li atom. We derive complete formulas for the mα^{6} and mα^{7}lnα contributions and calculate them numerically using highly optimized, explicitly correlated basis functions. The obtained results are in agreement with the most recent measurement, helping to resolve discrepancies between former ones and lay the foundation for the investigation of QED effects in light, many-electron atoms.

  6. Are 2P/Encke, the Taurid complex NEOs and CM chondrites related?

    NASA Astrophysics Data System (ADS)

    Tubiana, C.; Snodgrass, C.; Michelsen, R.; Haack, H.; Fitzsimmons, A.; Williams, I.; Boehnhardt, H.

    2013-09-01

    Comet 2P/Encke is a short-period comet that was discovered in 1786 and has been extensively observed and studied for more than 200 years. It has an orbital period of 3.3 years and its orbit is dynamically decoupled from Jupiter's control due to gravitational interaction with terrestrial planets [6]. It is the only comet known on such an orbit, making it unique. Capture from the outer solar system onto its current orbit is very unlikely and even a continuous smooth dynamical evolution has a low probability as this requires a continuous period when it is dormant in order to avoid the volatiles from the nucleus becoming exhausted and making the current observed activity impossible. An origin in the asteroid belt is a possibility especially in view of the recently discovered main belt comets. The nucleus of 2P/Encke is dark (geometric albedo of 0.047 ± 0.023 [3]), has an effective radius of 2.4 ± 0.3 km [3] and it has polarimetric properties that are unique compared to other measured types of solar system objects, such as asteroids, TNOs, cometary dust, Centaurs [2]. The colors of 2P/Encke's nucleus are typical for comets, but no spectra of the nucleus in the visible wavelength range exist so far. The Taurid meteoroid stream has long been linked with 2P/Encke, but the activity of the comet is not strong enough to explain the number of observed meteors. It has been suggested that the meteoroid stream was caused by the break up of a larger parent body, which left comet 2P/Encke and other various small bodies along with a stream of dust. Various small near-Earth objects (NEOs) have been discovered with orbits that can be linked with 2P/Encke and the Taurid meteoroid stream [1]. Though many of the associations are spurious due to the low inclination of 2P/Encke's orbit, many NEO's have evolved in a similar way to 2P/Encke overa period of 5000 years [8] suggesting some relationship. In addition to dynamical properties, common taxonomic properties can also provide an

  7. SR-2P Vaginal Microbicide Gel Provides Protection against Herpes Simplex Virus 2 When Administered as a Combined Prophylactic and Postexposure Therapeutic

    PubMed Central

    Fields, Scott A.; Bhatia, Gaurav; Fong, Julie M.; Liu, Mingtao

    2015-01-01

    Previously, we demonstrated that a single prophylactic dose of SR-2P, a novel dual-component microbicide gel comprising acyclovir and tenofovir, led to a modest increase in mouse survival following a lethal challenge of herpes simplex virus 2 (HSV-2). Here, we show that a dose of SR-2P administered 24 h prior to infection provides some protection against the virus, but to a lesser degree than SR-2P administered either once a day for 2 days or 1 h prior to infection. None of the prophylactic doses blocked infection by the virus, and all resulted in 80 to 100% lethality. However, given that a prophylactic dose still provided a significant reduction in overall clinical score, reduced rate of body weight loss, and increased median survival of the mice, we examined whether a repetitive dose regimen (postinfection) in addition to the prophylactic dose could prevent death and reduce the levels of virus in mice. Nearly all (9 of 10 in each group) of the mice that received SR-2P for 2 days prior to infection or that received SR-2P 1 h prior to infection and were administered SR-2P once a day for 10 days after infection showed no clinical symptoms of infection and no viral loads in vaginal swabs and survived for 28 days postinfection. Conversely, mice receiving no treatment or an identical vehicle treatment demonstrated advanced clinical signs and did not survive past day 9 postinfection. We conclude that SR-2P is an effective anti-HSV-2 agent in mice. PMID:26149989

  8. PRC2 complexes with JARID2, MTF2, and esPRC2p48 in ES cells to modulate ES cell pluripotency and somatic cell reprogramming.

    PubMed

    Zhang, Zhuo; Jones, Amanda; Sun, Chiao-Wang; Li, Chao; Chang, Chia-Wei; Joo, Heui-Yun; Dai, Qian; Mysliwiec, Matthew R; Wu, Li-Chen; Guo, Yahong; Yang, Wei; Liu, Kaimao; Pawlik, Kevin M; Erdjument-Bromage, Hediye; Tempst, Paul; Lee, Youngsook; Min, Jinrong; Townes, Tim M; Wang, Hengbin

    2011-02-01

    Polycomb repressive complex two (PRC2) has been implicated in embryonic stem (ES) cell pluripotency; however, the mechanistic roles of this complex are unclear. It was assumed that ES cells contain PRC2 with the same subunit composition as that identified in HeLa cells and Drosophila embryos. Here, we report that PRC2 in mouse ES cells contains at least three additional subunits: JARID2, MTF2, and a novel protein denoted esPRC2p48. JARID2, MTF2, and esPRC2p48 are highly expressed in mouse ES cells compared to differentiated cells. Importantly, knockdowns of JARID2, MTF2, or esPRC2p48 alter the level of PRC2-mediated H3K27 methylation and result in the expression of differentiation-associated genes in ES cells. Interestingly, expression of JARID2, MTF2, and esPRC2p48 together, but not individually, enhances Oct4/Sox2/Klf4-mediated reprogramming of mouse embryonic fibroblasts (MEFs) into induced pluripotent stem cells, whereas knockdown or knockout of JARID2, MTF2, or esPRC2p48 significantly inhibits reprogramming. JARID2, MTF2, and esPRC2p48 modulate H3K27 methylation and facilitate repression of lineage-associated gene expression when transduced into MEFs, and synergistically stimulate the histone methyltransferase activity of PRC2 in vitro. Therefore, these studies identify JARID2, MTF2, and esPRC2p48 as important regulatory subunits of PRC2 in ES cells and reveal critical functions of these subunits in modulating PRC2's activity and gene expression both in ES cells and during somatic cell reprogramming.

  9. Inner Core Rotation from Geomagnetic Westward Drift and a Stationary Spherical Vortex in Earth's Core

    NASA Technical Reports Server (NTRS)

    Voorhies, C. V.

    1999-01-01

    The idea that geomagnetic westward drift indicates convective leveling of the planetary momentum gradient within Earth's core is pursued in search of a differentially rotating mean state, upon which various oscillations and secular effects might be superimposed. The desired state conforms to roughly spherical boundary conditions, minimizes dissipative interference with convective cooling in the bulk of the core, yet may aide core cooling by depositing heat in the uppermost core and lower mantle. The variational calculus of stationary dissipation applied to a spherical vortex within the core yields an interesting differential rotation profile akin to spherical Couette flow bounded by thin Hartmann layers. Four boundary conditions are required. To concentrate shear induced dissipation near the core-mantle boundary, these are taken to be: (i) no-slip at the core-mantle interface; (ii) geomagnetically estimated bulk westward flow at the base of the core-mantle boundary layer; (iii) no-slip at the inner-outer core interface; and, to describe magnetic locking of the inner core to the deep outer core, (iv) hydrodynamically stress-free at the inner-outer core boundary. By boldly assuming the axial core angular momentum anomaly to be zero, the super-rotation of the inner core is calculated to be at most 1.5 degrees per year.

  10. Inner Core Rotation from Geomagnetic Westward Drift and a Stationary Spherical Vortex in Earth's Core

    NASA Technical Reports Server (NTRS)

    Voorhies, Coerte V.

    1998-01-01

    The idea that geomagnetic westward drift indicates convective leveling of the planetary momentum gradient within Earth's core is pursued in search of a differentially rotating mean state, upon which various oscillations and secular effects might be superimposed. The desired state conforms to roughly spherical boundary conditions, minimizes dissipative interference with convective cooling in the bulk of the core, yet may aid core cooling by depositing heat in the uppermost core and lower mantle. The variational calculus of stationary dissipation applied to a spherical vortex within the core yields an interesting differential rotation profile, akin to spherical Couette flow bounded by thin Hartmann layers. Four boundary conditions are required. To concentrate shear induced dissipation near the core-mantle boundary, these are taken to be: (i) no-slip at the core-mantle interface; (ii) geomagnetically estimated bulk westward flow at the base of the core-mantle boundary layer; (iii) no-slip at the inner-outer core interface; and, to describe magnetic locking of the inner core to the deep outer core; (iv) hydrodynamically stress-free at the inner-outer core boundary. By boldly assuming the axial core angular momentum anomaly to be zero, the super-rotation of the inner core relative to the mantle is calculated to be at most 1.5 deg./yr.

  11. Academic Rigor: The Core of the Core

    ERIC Educational Resources Information Center

    Brunner, Judy

    2013-01-01

    Some educators see the Common Core State Standards as reason for stress, most recognize the positive possibilities associated with them and are willing to make the professional commitment to implementing them so that academic rigor for all students will increase. But business leaders, parents, and the authors of the Common Core are not the only…

  12. Spectroscopic investigations and quantum chemical computational study of (E)-4-methoxy-2-[(p-tolylimino)methyl]phenol.

    PubMed

    Kosar, Basak; Albayrak, Cigdem

    2011-01-01

    In this work the electronic structure of (E)-4-methoxy-2-[(p-tolylimino)methyl]phenol has been characterized by the B3LYP/6-31G(d) level by using density functional theory. The experimental infrared and electronic absorption spectra have been obtained and compared with the theoretically obtained ones. Molecular electrostatic potential map has been evaluated; natural bond orbital and frontier molecular orbitals analysis have been performed from the optimized geometry. The energetic behavior of the title compound has been examined in solvent media using polarizable continuum model. The non-linear optical properties have been computed with the same level of theory. In addition, the changes of thermodynamic properties have been obtained in the range of 100-500 K.

  13. The − 5 A/G single-nucleotide polymorphism in the core promoter region of MT2A and its effect on allele-specific gene expression and Cd, Zn and Cu levels in laryngeal cancer

    SciTech Connect

    Starska, Katarzyna; Krześlak, Anna; Forma, Ewa; Morawiec-Sztandera, Alina; Aleksandrowicz, Paweł; Lewy-Trenda, Iwona; and others

    2014-10-15

    Metallothioneins (MTs) are low molecular weight, cysteine-rich heavy metal-binding proteins which participate in the mechanisms of Zn homeostasis, and protect against toxic metals. MTs contain metal-thiolate cluster groups and suppress metal toxicity by binding to them. The aim of this study was to determine the − 5 A/G (rs28366003) single-nucleotide polymorphism (SNP) in the core promoter region of the MT2A gene and to investigate its effect on allele-specific gene expression and Cd, Zn and Cu content in squamous cell laryngeal cancer (SCC) and non-cancerous laryngeal mucosa (NCM) as a control. The MT2A promoter region − 5 A/G SNP was determined by restriction fragment length polymorphism using 323 SCC and 116 NCM. MT2A gene analysis was performed by quantitative real-time PCR. The frequency of A allele carriage was 94.2% and 91.8% in SCC and NCM, respectively, while G allele carriage was detected in 5.8% and 8.2% of SCC and NCM samples, respectively. As a result, a significant association was identified between the − 5 A/G SNP in the MT2A gene with mRNA expression in both groups. Metal levels were analyzed by flame atomic absorption spectrometry. The significant differences were identified between A/A and both the A/G and G/G genotypes, with regard to the concentration of the contaminating metal. The Spearman rank correlation results showed that the MT2A expression and Cd, Zn, Cu levels were negatively correlated. Results obtained in this study suggest that − 5 A/G SNP in MT2A gene may have an effect on allele-specific gene expression and accumulation of metal levels in laryngeal cancer. - Highlights: • MT2A gene expression and metal content in laryngeal cancer tissues • Association between SNP (rs28366003) and expression of MT2A • Significant associations between the SNP and Cd, Zn and Cu levels • Negative correlation between MT2A gene expression and Cd, Zn and Cu levels.

  14. Effect of electrical steel grade on transformer core audible noise

    NASA Astrophysics Data System (ADS)

    Valkovic, Z.

    1994-05-01

    The effect of different core material grades (M4, MOH and ZDKH) on noise level was investigated experimentally on single-phase dry-type transformer models. Two types of core design were used (conventional mitred overlapping and step-lap overlapping). The models with MOH and ZDKH material have roughly the same noise levels. The models with M4 grade material have higher noise levels than those with MOH or ZDKH, but the difference depends on core induction and core design.

  15. 1s2s2p{sup 2}3s {sup 6}P-1s2p{sup 3}3s {sup 6}S{sup o} Transitions in O IV

    SciTech Connect

    Lin Bin; Berry, H. Gordon; Shibata, Tomohiro; Livingston, A. Eugene; Savukov, Igor; Garnir, Henri-Pierre; Bastin, Thierry; Desesquelles, J.

    2003-06-01

    The energies and lifetimes of doubly excited sextet states of boron-like O IV, F V, and Ne VI are calculated with the multiconfiguration Hartree-Fock approach, including QED and higher-order corrections, and also with the multiconfiguration Dirac-Fock GRASP code. The wavelengths and transition rates of electric-dipole transitions from the inner-shell excited terms 1s2s2p{sup 2}3s {sup 6}P-1s2p{sup 3}3s {sup 6}S{sup o} are investigated by beam-foil spectroscopy in the XUV spectral region. The predicted transition wavelengths agree with the experiment. The higher-order corrections, fine structures, and spectrum with high wavelength resolution are found to be critically important in these comparisons. Nine new lines have been identified. The ground sextet states of boronlike atoms are metastable and well above several ionization levels. These are possible candidates for XUV and soft x-ray lasers.

  16. Core to College Evaluation: Exploring the Use of Multiple Measures for Placement into College-Level Courses. Seeking Alternatives or Improvements to the Use of a Single Standardized Test

    ERIC Educational Resources Information Center

    Bracco, Kathy Reeves; Dadgar, Mina; Austin, Kim; Klarin, Becca; Broek, Marie; Finkelstein, Neal; Mundry, Susan; Bugler, Dan

    2014-01-01

    "Core to College: Preparing Students for College Readiness and Success" is a three-year initiative. The initiative's mission is to "facilitate greater coordination between K-12 and postsecondary education systems around implementation of the Common Core State Standards (CCSS) and aligned assessments." Its aim is to foster…

  17. Couplings between Chern-Simons gravities and 2p-branes

    SciTech Connect

    Miskovic, Olivera; Zanelli, Jorge

    2009-08-15

    The interaction between Chern-Simons (CS) theories and localized external sources (2p-branes) is analyzed. This interaction generalizes the minimal coupling between a point charge (0-brane) and a gauge connection. The external currents that define the 2p branes are covariantly constant (D-2p-1)-forms coupled to (2p-1) CS forms. The general expression for the sources--charged with respect to the corresponding gauge algebra--is presented, focusing on two special cases: 0-branes and (D-3)-branes. In any dimension, 0-branes are constructed as topological defects produced by a surface deficit of (D-2)-sphere in anti-de Sitter space, and they are not constant curvature spaces for D>3. They correspond to dimensionally continued black holes with negative mass. On the other hand, in the case of CS (super) gravities, the (D-3)-branes are naked conical singularities (topological defects) obtained by identification of points with a Killing vector. In 2+1 dimensions, extremal spinning branes of this type are Bogomol'nyi-Prasad-Sommerfield states. Stable (D-3)-branes are shown to exist also in higher dimensions, as well. Classical field equations are also discussed, and in the presence of sources there is a large number of inequivalent and disconnected sectors in solution space.

  18. 76 FR 65558 - Rescission of Social Security Ruling 97-2p

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-21

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY ADMINISTRATION Rescission of Social Security Ruling 97-2p AGENCY: Social Security Administration. ACTION: Notice of rescission of Social Security Ruling. SUMMARY: In accordance with 20 CFR 402.35(b)(1),...

  19. Scalable P2P Overlays of Very Small Constant Degree: An Emerging Security Threat

    NASA Astrophysics Data System (ADS)

    Jelasity, Márk; Bilicki, Vilmos

    In recent years peer-to-peer (P2P) technology has been adopted by Internet-based malware as a fault tolerant and scalable communication medium for self-organization and survival. It has been shown that malicious P2P networks would be nearly impossible to uncover if they operated in a stealth mode, that is, using only a small constant number of fixed overlay connections per node for communication. While overlay networks of a small constant maximal degree are generally considered to be unscalable, we argue in this paper that it is possible to design them to be scalable, efficient and robust. This is an important finding from a security point of view: we show that stealth mode P2P malware that is very difficult to discover with state-of-the-art methods is a plausible threat. In this paper we discuss algorithms and theoretical results that support the scalability of stealth mode overlays, and we present realistic simulations using an event based implementation of a proof-of-concept system. Besides P2P botnets, our results are also applicable in scenarios where relying on a large number of overlay connections per node is not feasible because of cost or the limited number of communication channels available.

  20. Highly efficient acousto-optic diffraction in Sn2P2S6 crystals.

    PubMed

    Martynyuk-Lototska, I Yu; Mys, O G; Grabar, A A; Stoika, I M; Vysochanskii, Yu M; Vlokh, R O

    2008-01-01

    We have studied the acousto-optic (AO) diffraction in Sn2P2S6 crystals and found that they manifest high values of an AO figure of merit. The above crystals may therefore be used as highly efficient materials in different AO applications.

  1. Calculation of total differential cross section: Na(/sup 2/P)+Xe p

    SciTech Connect

    DeVries, P.L.

    1984-03-01

    A quantum-mechanical treatment is used to determine the total differential cross section for collisions of excited sodium atoms with xenon. A rainbowlike structure in the angular distribution is predicted for collisions involving sodium in the /sup 2/P/sub 1/2/ state.

  2. Brr2p carboxy-terminal Sec63 domain modulates Prp16 splicing RNA helicase

    PubMed Central

    Cordin, Olivier; Hahn, Daniela; Alexander, Ross; Gautam, Amit; Saveanu, Cosmin; Barrass, J. David; Beggs, Jean D.

    2014-01-01

    RNA helicases are essential for virtually all cellular processes, however, their regulation is poorly understood. The activities of eight RNA helicases are required for pre-mRNA splicing. Amongst these, Brr2p is unusual in having two helicase modules, of which only the amino-terminal helicase domain appears to be catalytically active. Using genetic and biochemical approaches, we investigated interaction of the carboxy-terminal helicase module, in particular the carboxy-terminal Sec63-2 domain, with the splicing RNA helicase Prp16p. Combining mutations in BRR2 and PRP16 suppresses or enhances physical interaction and growth defects in an allele-specific manner, signifying functional interactions. Notably, we show that Brr2p Sec63-2 domain can modulate the ATPase activity of Prp16p in vitro by interfering with its ability to bind RNA. We therefore propose that the carboxy-terminal helicase module of Brr2p acquired a regulatory function that allows Brr2p to modulate the ATPase activity of Prp16p in the spliceosome by controlling access to its RNA substrate/cofactor. PMID:25428373

  3. Radiationless S 1 → S 0 phenyl deactivation pathway: an investigation of iodine-marked bi-phenyl on a silicon surface by means of time resolved core-level photoelectron spectroscopy

    NASA Astrophysics Data System (ADS)

    Michelswirth, Martin; Dachraoui, Hatem; Mattay, Jochen; Heinzmann, Ulrich

    2012-02-01

    The S 1 → S 0 radiationless deactivation of iodine terminated bi-phenyl immobilized on a silicon surface was probed by analysing the I4d signature (BE: 45.6 eV, 47.3 eV) by means of High Harmonic Generation (HHG) based photoelectron spectroscopy. Modifications of the 4d5/2,3/2 spectroscopic contents spanning about 0.2 ps after UV activation (266 nm) were verified as showing a transient molecular response character. A localization to the terminated phenyl substructure in the complex structural environment on the surface was ensured according to the core-level nature of the recorded I4d. The activation of the bi-phenyl achieved by UV irradiation, corresponding to the UV absorption band-edge, was verified as being dominated by a Bπ → Bπ* phenyl excitation. Time-Dependent Density Functional Theory (TD-DFT) modellings were therefore performed. They were matched to Configuration Interaction semi-empirical calculations (CI-MNDO) verifying the Rustagi-Ducuing relation. The simulated singlet-singlet excitation spectrum was referenced to the spectra of an iodine terminated monomer and a linear oligophenyl chain (N = 8). Thus the deactivation response studied was assigned to a conical intersection promoted ? reaction pathway.

  4. Semiconducting ZnSnN2 thin films for Si/ZnSnN2 p-n junctions

    NASA Astrophysics Data System (ADS)

    Qin, Ruifeng; Cao, Hongtao; Liang, Lingyan; Xie, Yufang; Zhuge, Fei; Zhang, Hongliang; Gao, Junhua; Javaid, Kashif; Liu, Caichi; Sun, Weizhong

    2016-04-01

    ZnSnN2 is regarded as a promising photovoltaic absorber candidate due to earth-abundance, non-toxicity, and high absorption coefficient. However, it is still a great challenge to synthesize ZnSnN2 films with a low electron concentration, in order to promote the applications of ZnSnN2 as the core active layer in optoelectronic devices. In this work, polycrystalline and high resistance ZnSnN2 films were fabricated by magnetron sputtering technique, then semiconducting films were achieved after post-annealing, and finally Si/ZnSnN2 p-n junctions were constructed. The electron concentration and Hall mobility were enhanced from 2.77 × 1017 to 6.78 × 1017 cm-3 and from 0.37 to 2.07 cm2 V-1 s-1, corresponding to the annealing temperature from 200 to 350 °C. After annealing at 300 °C, the p-n junction exhibited the optimum rectifying characteristics, with a forward-to-reverse ratio over 103. The achievement of this ZnSnN2-based p-n junction makes an opening step forward to realize the practical application of the ZnSnN2 material. In addition, the nonideal behaviors of the p-n junctions under both positive and negative voltages are discussed, in hope of suggesting some ideas to further improve the rectifying characteristics.

  5. Multiple regulatory roles of the carboxy terminus of Ste2p a yeast GPCR.

    PubMed

    Kim, Kyeong-Man; Lee, Yong-Hun; Akal-Strader, Ayca; Uddin, M Seraj; Hauser, Melinda; Naider, Fred; Becker, Jeffrey M

    2012-01-01

    Signaling and internalization of Ste2p, a model G protein-coupled receptor (GPCR) from the yeast Saccharomyces cerevisiae, are reported to be regulated by phosphorylation status of serine (S) and threonine (T) residues located in the cytoplasmic C-terminus. Although the functional roles of S/T residues located in certain C-terminus regions are relatively well characterized, systemic analyses have not been conducted for all the S/T residues that are spread throughout the C-terminus. A point mutation to alanine was introduced into the S/T residues located within three intracellular loops and the C-terminus individually or in combination. A series of functional assays such as internalization, FUS1-lacZ induction, and growth arrest were conducted in comparison between WT- and mutant Ste2p. The Ste2p in which all S/T residues in the C-terminus were mutated to alanine was more sensitive to α-factor, suggesting that phosphorylation in the C-terminus exerts negative regulatory activities on the Ste2p signaling. C-terminal S/T residues proximal to the seventh transmembrane domain were important for ligand-induced G protein coupling but not for receptor internalization. Sites on the central region of the C-terminus regulated both constitutive and ligand-induced internalization. Residues on the distal part were important for constitutive desensitization and modulated the G protein signaling mediated through the proximal part of the C-terminus. This study demonstrated that the C-terminus contains multiple functional domains with differential and interdependent roles in regulating Ste2p function in which the S/T residues located in each domain play critical roles. PMID:22100461

  6. Genitourinary Defects Associated with Genomic Deletions in 2p15 Encompassing OTX1

    PubMed Central

    Jorgez, Carolina J.; Rosenfeld, Jill A.; Wilken, Nathan R.; Vangapandu, Hima V.; Sahin, Aysegul; Pham, Dung; Carvalho, Claudia M. B.; Bandholz, Anne; Miller, Amanda; Weaver, David D.; Burton, Barbara; Babu, Deepti; Bamforth, John S.; Wilks, Timothy; Flynn, Daniel P.; Roeder, Elizabeth; Patel, Ankita; Cheung, Sau W.; Lupski, James R.; Lamb, Dolores J.

    2014-01-01

    Normal development of the genitourinary (GU) tract is a complex process that frequently goes awry. In male children the most frequent congenital GU anomalies are cryptorchidism (1–4%), hypospadias (1%) and micropenis (0.35%). Bladder exstrophy and epispadias complex (BEEC) (1∶47000) occurs less frequently but significantly impacts patients' lives. Array comparative genomic hybridization (aCGH) identified seven individuals with overlapping deletions in the 2p15 region (66.0 kb-5.6 Mb). Six of these patients have GU defects, while the remaining patient has no GU defect. These deletions encompass the transcription factor OTX1. Subjects 2–7 had large de novo CNVs (2.39–6.31 Mb) and exhibited features similar to those associated with the 2p15p16.1 and 2p15p14 microdeletion syndromes, including developmental delay, short stature, and variable GU defects. Subject-1 with BEEC had the smallest deletion (66 kb), which deleted only one copy of OTX1. Otx1-null mice have seizures, prepubescent transient growth retardation and gonadal defects. Two subjects have short stature, two have seizures, and six have GU defects, mainly affecting the external genitalia. The presence of GU defects in six patients in our cohort and eight of thirteen patients reported with deletions within 2p14p16.1 (two with deletion of OTX1) suggest that genes in 2p15 are important for GU development. Genitalia defects in these patients could result from the effect of OTX1 on pituitary hormone secretion or on the regulation of SHH signaling, which is crucial for development of the bladder and genitalia. PMID:25203062

  7. A new barium titanium (III) pyrophosphate: BaTi 2(P 2O 7) 2

    NASA Astrophysics Data System (ADS)

    Wang, Shumin; Hwu, Shiou-Jyh

    1991-01-01

    The new barium titanium (III) pyrophosphate BaTi 2(P 2O 7) 2 has been prepared by conventional high temperature solid state reaction at 900°C in a fused silica tube. BaTi 2(P 2O 7) 2 crystallizes with four formula units in a cell with dimensions a = 10.680(3) Å, b = 10.564(4) Å, c = 9.834(4) Å/, β = 102.88(3)° and V = 1081.6(6) Å 3 in space group C 62h  C {2}/{c} (No. 15) of the monoclinic system. The single crystal structure refinement gives a final structure solution with R index on F2o of 0.018 for 99 variables and GOF = 1.05. BaTi 2(P 2O 7) 2 displays a new layered type structure which consists of layers of slightly distorted TiO 6 octahedra with (P 2O 7) and (BaO 10) polyhedra between the layers. The structural framework is built up from corner-sharing TiO 6 octahedra and P 2O 7 pyrophosphate groups, to give rise to [Ti 2(P 2O 7) 2] 2- units and to form tunnels where the barium cations reside. Magnetic susceptibility measurements on selected single crystals confirm the presence of Ti 3+ ( d1) ions with spin S = {1}/{2}. The high oxidative thermal stability of BaTi 2(P 2O 7) 2 versus the stabilities of other trivalent titanium cation-containing compounds, including Ti 2O 3, TiPO 4, and BaTi 2(PO 4) 3, owing to possible anion matrix effects are discussed.

  8. O2, pH, and redox potential microprofiles around Potamogeton malaianus measured using microsensors.

    PubMed

    Dong, Bin; Han, Ruiming; Wang, Guoxiang; Cao, Xun

    2014-01-01

    This study aimed to elucidate the effects of periphyton on the microprofiles of oxygen (O2), pH, and oxidation-reduction potential around the stems and leaves of a submerged macrophyte Potamogeton malaianus and on the plant growth in the eutrophic shallow Taihu Lake, China. The microprofiles were measured using a motorized microprofiling system equipped with microsensors. The leaf age of the macrophyte and periphyton exerted significant effects on the microprofiles of O2, pH, and oxidation-reduction potential. O2 concentration and pH increased whereas the oxidation-reduction potential decreased with decreasing distance to the stem/leaf surface. The fluctuation amplitudes of O2, pH, and oxidation-reduction potential were the largest in the microprofiles of mature leaves and the lowest in senescent leaves. The periphyton increased the thickness of the broad diffusive boundary layer and fluctuation amplitudes of O2, pH, and oxidation-reduction potential. When the periphyton was removed, the thickness of the broad diffusive boundary layer in the microprofiles of stems, senescent leaves, and mature leaves reduced by 29.0%, 49.72%, and 70.34%, and the O2, pH, and oxidation-reduction potential fluctuation amplitudes also declined accordingly. Our results suggest that a thick periphyton exerted negative effects on the growth of macrophytes by providing extensive shading and creating a barrier that hindered the transport of dissolved substances such as O2, and led to premature decline in macrophytes in the eutrophic Taihu Lake. The consequent implications can help to elucidate the control mechanism of the broad diffusive boundary layer around macrophytes on nutrient cycling in eutrophic waters and to better understand the role of this layer in the Taihu Lake and other similar eutrophic waters. PMID:25004129

  9. O2, pH, and Redox Potential Microprofiles around Potamogeton malaianus Measured Using Microsensors

    PubMed Central

    Dong, Bin; Han, Ruiming; Wang, Guoxiang; Cao, Xun

    2014-01-01

    This study aimed to elucidate the effects of periphyton on the microprofiles of oxygen (O2), pH, and oxidation-reduction potential around the stems and leaves of a submerged macrophyte Potamogeton malaianus and on the plant growth in the eutrophic shallow Taihu Lake, China. The microprofiles were measured using a motorized microprofiling system equipped with microsensors. The leaf age of the macrophyte and periphyton exerted significant effects on the microprofiles of O2, pH, and oxidation-reduction potential. O2 concentration and pH increased whereas the oxidation-reduction potential decreased with decreasing distance to the stem/leaf surface. The fluctuation amplitudes of O2, pH, and oxidation-reduction potential were the largest in the microprofiles of mature leaves and the lowest in senescent leaves. The periphyton increased the thickness of the broad diffusive boundary layer and fluctuation amplitudes of O2, pH, and oxidation-reduction potential. When the periphyton was removed, the thickness of the broad diffusive boundary layer in the microprofiles of stems, senescent leaves, and mature leaves reduced by 29.0%, 49.72%, and 70.34%, and the O2, pH, and oxidation-reduction potential fluctuation amplitudes also declined accordingly. Our results suggest that a thick periphyton exerted negative effects on the growth of macrophytes by providing extensive shading and creating a barrier that hindered the transport of dissolved substances such as O2, and led to premature decline in macrophytes in the eutrophic Taihu Lake. The consequent implications can help to elucidate the control mechanism of the broad diffusive boundary layer around macrophytes on nutrient cycling in eutrophic waters and to better understand the role of this layer in the Taihu Lake and other similar eutrophic waters. PMID:25004129

  10. Crystal structure of an archaeal Ski2p-like protein from Pyrococcus horikoshii OT3.

    PubMed

    Zhang, Xiaodong; Nakashima, Takashi; Kakuta, Yoshimitsu; Yao, Min; Tanaka, Isao; Kimura, Makoto

    2008-01-01

    The Ski complex composed of Ski2p, Ski3p, and Ski8p plays an essential role in the 3' to 5' cytoplasmic mRNA degradation pathway in yeast. Ski2p is a putative RNA helicase, belonging in the DExD/H-box protein families and conserved in eukarya as well as in archaea. The gene product (Ph1280p) from the hyperthermophilic archaeon Pyrococcus horikoshii OT3 shows sequence homology with Ski2p, sharing 22.6% identical amino acids with a central region of Ski2p. In order to gain structural information about the Ski2p-like RNA helicase, we overproduced Ph1280p in Escherichia coli cells, and purified it to apparent homogeneity. Ph1280p exhibits DNA/RNA-dependent ATPase activity with an optimal temperature at approximately 90 degrees C. The crystal structure of Ph1280p has been solved at a resolution of 3.5 A using single-wavelength anomalous dispersion (SAD) and selenomethionyl (Se-Met)-substituted protein. Ph1280p comprises four subdomains; the two N-terminal subdomains (N1 and N2) fold into an RecA-like architecture with the conserved helicase motifs, while the two C-terminal subdomains (C1 and C2) fold into alpha-helical structures containing a winged helix (WH)-fold and helix-hairpin-helix (HhH)-fold, respectively. Although the structure of each of the Ph1280p subdomains can be individually superimposed on the corresponding domains in other helicases, such as the Escherichia coli DNA helicase RecQ, the relative orientation of the helicase and C-terminal subdomains in Ph1280p is significantly different from that of other helicases. This structural feature is implicated in substrate specificity for the Ski2-like helicase and would play a critical role in the 3' to 5' cytoplasmic mRNA degradation in the Ski complex. PMID:18042682

  11. α and 2 p 2 n emission in fast neutron-induced reactions on 60Ni

    NASA Astrophysics Data System (ADS)

    Fotiades, N.; Devlin, M.; Haight, R. C.; Nelson, R. O.; Kunieda, S.; Kawano, T.

    2015-06-01

    Background: The cross sections for populating the residual nucleus in the reaction ZAX(n,x) Z -2 A -4Y exhibit peaks as a function of incident neutron energy corresponding to the (n ,n'α ) reaction and, at higher energy, to the (n ,2 p 3 n ) reaction. The relative magnitudes of these peaks vary with the Z of the target nucleus. Purpose: Study fast neutron-induced reactions on 60Ni. Locate experimentally the nuclear charge region along the line of stability where the cross sections for α emission and for 2 p 2 n emission in fast neutron-induced reactions are comparable as a further test of reaction models. Methods: Data were taken by using the Germanium Array for Neutron-Induced Excitations. The broad-spectrum pulsed neutron beam of the Los Alamos Neutron Science Center's Weapons Neutron Research facility provided neutrons in the energy range from 1 to 250 MeV. The time-of-flight technique was used to determine the incident-neutron energies. Results: Absolute partial cross sections for production of seven discrete Fe γ rays populated in 60Ni (n ,α /2 p x n γ ) reactions with 2 ≤x ≤5 were measured for neutron energies 1 MeV2 p 2 n and 2 p 3 n emission at higher incident energies in the nuclear charge region around Fe.

  12. Prevalence of Serologic Hepatitis B Markers in Blood Donors From Puebla, Mexico: The Association of Relatively High Levels of Anti-Core Antibodies With the Detection of Surface Antigen and Genomic DNA

    PubMed Central

    Sosa-Jurado, Francisca; Hilda Rosas-Murrieta, Nora; Guzman-Flores, Belinda; Perez Zempoaltecalt, Cintia; Patricia Sanchez Torres, Ana; Ramirez Rosete, Leticia; Bernal-Soto, Maribel; Marquez-Dominguez, Luis; Melendez-Mena, Daniel; Angel Mendoza Torres, Miguel; Teresa Lopez Delgado, Maria; Reyes-Leyva, Julio; Vallejo-Ruiz, Veronica; Santos-Lopez, Gerardo

    2016-01-01

    Background The hepatitis B virus (HBV) causes chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. Surface antigen (HBsAg) detection is a definitive test that can confirm HBV infection, while the presence of antibodies against the core protein (anti-HBc) suggests either a previous or ongoing infection or occult hepatitis B infection (OBI). Objectives The aim of the present study was to determine the prevalence of anti-HBc and HBsAg in blood donors. Further, the study aimed to estimate the anti-HBc level at which HBV DNA is detected in putative OBI cases, as well as to search for mutations in the “a” determinant associated with the non-detection of HBsAg in serum. Patients and Methods We conducted a cross-sectional study from 2003–2009. The study included 120,552 blood donors from the state of Puebla, Mexico. Different commercial systems based on microparticles (enzymatic (MEIA) or chemiluminescent (CMIA)) were used to determine the HBsAg and anti-HBc levels. For the detection of HBV DNA, a nested polymerase chain reaction (nested PCR) was used and the genotypes were determined using Sanger sequencing. Results Of the 120,552 blood donors, 1437 (1.19%, 95% CI: 1.12 - 1.26) were reactive to anti-HBc, while 82 (0.066%, 95% CI: 0.053 - 0.079) were reactive to HBsAg. Some 156 plasma samples collected in 2009 from anti-HBc-positive/HBsAg-negative blood donors were submitted for HBV DNA detection in a search for probable OBI. Viral DNA was detected in 27/156 (17.3%, 95% CI: 11.5 - 23.1). Our results show an association between HBV DNA or HBsAg and anti-HBc S/CO levels ≥ 4.0. All DNA samples were identified as genotype H and some “a” determinant mutations were identified, although none corresponded to mutations previously reported to hinder the detection of HBsAg by commercial immunoassays. Conclusions We observed that as the anti-HBc levels increase, there is a higher prevalence of the viral protein HBsAg in blood donors. Samples testing positive

  13. Prevalence of Serologic Hepatitis B Markers in Blood Donors From Puebla, Mexico: The Association of Relatively High Levels of Anti-Core Antibodies With the Detection of Surface Antigen and Genomic DNA

    PubMed Central

    Sosa-Jurado, Francisca; Hilda Rosas-Murrieta, Nora; Guzman-Flores, Belinda; Perez Zempoaltecalt, Cintia; Patricia Sanchez Torres, Ana; Ramirez Rosete, Leticia; Bernal-Soto, Maribel; Marquez-Dominguez, Luis; Melendez-Mena, Daniel; Angel Mendoza Torres, Miguel; Teresa Lopez Delgado, Maria; Reyes-Leyva, Julio; Vallejo-Ruiz, Veronica; Santos-Lopez, Gerardo

    2016-01-01

    Background The hepatitis B virus (HBV) causes chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. Surface antigen (HBsAg) detection is a definitive test that can confirm HBV infection, while the presence of antibodies against the core protein (anti-HBc) suggests either a previous or ongoing infection or occult hepatitis B infection (OBI). Objectives The aim of the present study was to determine the prevalence of anti-HBc and HBsAg in blood donors. Further, the study aimed to estimate the anti-HBc level at which HBV DNA is detected in putative OBI cases, as well as to search for mutations in the “a” determinant associated with the non-detection of HBsAg in serum. Patients and Methods We conducted a cross-sectional study from 2003–2009. The study included 120,552 blood donors from the state of Puebla, Mexico. Different commercial systems based on microparticles (enzymatic (MEIA) or chemiluminescent (CMIA)) were used to determine the HBsAg and anti-HBc levels. For the detection of HBV DNA, a nested polymerase chain reaction (nested PCR) was used and the genotypes were determined using Sanger sequencing. Results Of the 120,552 blood donors, 1437 (1.19%, 95% CI: 1.12 - 1.26) were reactive to anti-HBc, while 82 (0.066%, 95% CI: 0.053 - 0.079) were reactive to HBsAg. Some 156 plasma samples collected in 2009 from anti-HBc-positive/HBsAg-negative blood donors were submitted for HBV DNA detection in a search for probable OBI. Viral DNA was detected in 27/156 (17.3%, 95% CI: 11.5 - 23.1). Our results show an association between HBV DNA or HBsAg and anti-HBc S/CO levels ≥ 4.0. All DNA samples were identified as genotype H and some “a” determinant mutations were identified, although none corresponded to mutations previously reported to hinder the detection of HBsAg by commercial immunoassays. Conclusions We observed that as the anti-HBc levels increase, there is a higher prevalence of the viral protein HBsAg in blood donors. Samples testing positive

  14. Binding the Atypical RA Domain of Ste50p to the Unfolded Opy2p Cytoplasmic Tail Is Essential for the High-Osmolarity Glycerol Pathway

    PubMed Central

    Ekiel, Irena; Sulea, Traian; Jansen, Gregor; Kowalik, Maria; Minailiuc, Ovidiu; Cheng, Jing; Harcus, Doreen; Cygler, Miroslaw; Whiteway, Malcolm

    2009-01-01

    Activation of the high-osmolarity glycerol (HOG) pathway for osmoregulation in the yeast Saccharomyces cerevisiae involves interaction of the adaptor Ste50p with the cytoplasmic tail of single-transmembrane protein Opy2p. We have determined the solution structure of the Ste50p-RA (Ras association) domain, and it shows an atypical RA fold lacking the β1 and β2 strands of the canonical motif. Although the core of the RA domain is fully functional in the pheromone response, an additional region is required for the HOG pathway activation. Two peptide motifs within the intrinsically disordered cytoplasmic tail of Opy2p defined by NMR spectroscopy physically interact with the Step50p-RA domain. These Opy2p-derived peptides bind overlapping regions of the Step50p-RA domain with similarly weak affinities, suggesting a multivalent interaction of these proteins as a crucial point of control of the HOG pathway. As well, overall selection of signaling pathways depends on functionally distinct regions of the Ste50p-RA domain, implicating this element in the control of global regulatory decisions. PMID:19846660

  15. HTTF Core Stress Analysis

    SciTech Connect

    Brian D. Hawkes; Richard Schultz

    2012-07-01

    In accordance with the need to determine whether cracking of the ceramic core disks which will be constructed and used in the High Temperature Test Facility (HTTF) for heatup and cooldown experiments, a set of calculation were performed using Abaqus to investigate the thermal stresses levels and likelihood for cracking. The calculations showed that using the material properties provided for the Greencast 94F ceramic, cracking is predicted to occur. However, this modeling does not predict the size or length of the actual cracks. It is quite likely that cracks will be narrow with rough walls which would impede the flow of coolant gases entering the cracks. Based on data recorded at Oregon State University using Greencast 94F samples that were heated and cooled at prescribed rates, it was concluded that the likelihood that the cracks would be detrimental to the experimental objectives is small.

  16. Extended calculations of level and transition properties in the nitrogen isoelectronic sequence: Cr XVIII, Fe XX, Ni XXII, and Zn XXIV

    NASA Astrophysics Data System (ADS)

    Radžiūtė, L.; Ekman, J.; Jönsson, P.; Gaigalas, G.

    2015-10-01

    Extensive multiconfiguration Dirac-Hartree-Fock (MCDHF) calculations and relativistic configuration interaction (RCI) calculations are performed for 272 states of the 2s22p3, 2s2p4, 2p5, 2s22p23l, 2s2p33l, and 2p43l (l = 0,1,2) configurations in the nitrogen-like ions Cr XVIII, Fe XX, Ni XXII, and Zn XXIV. Valence, core-valence, and core-core electron correlation effects are accounted for through large configuration state function expansions. Calculated energy levels are compared with data from other calculations and with experimental data from the NIST database. Landé gJ-factors; hyperfine structures; isotope shifts; and radiative electric dipole (E1), electric quadrupole (E2), and magnetic dipole (M1) transition rates are given for all ions. The accuracy of the calculated energy levels is high enough to facilitate identification of observed spectral lines involving the 2l43l' configurations, for which experimental data are largely missing. Tables 5-21 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/582/A61

  17. Core Design Applications

    1995-07-12

    CORD-2 is intended for core desigh applications of pressurized water reactors. The main objective was to assemble a core design system which could be used for simple calculations (such as frequently required for fuel management) as well as for accurate calculations (for example, core design after refueling).

  18. Benefits of a High School Core Curriculum

    ERIC Educational Resources Information Center

    ACT, Inc., 2006

    2006-01-01

    Since the publication of "A Nation at Risk", ACT has recommended that students take a core curriculum in high school in order to be prepared for college-level work. ACT's recommended core curriculum consists of four years of English and three years each of mathematics, science, and social studies. The benefits to students of taking the right…

  19. Reactor core isolation cooling system

    DOEpatents

    Cooke, F.E.

    1992-12-08

    A reactor core isolation cooling system includes a reactor pressure vessel containing a reactor core, a drywell vessel, a containment vessel, and an isolation pool containing an isolation condenser. A turbine is operatively joined to the pressure vessel outlet steamline and powers a pump operatively joined to the pressure vessel feedwater line. In operation, steam from the pressure vessel powers the turbine which in turn powers the pump to pump makeup water from a pool to the feedwater line into the pressure vessel for maintaining water level over the reactor core. Steam discharged from the turbine is channeled to the isolation condenser and is condensed therein. The resulting heat is discharged into the isolation pool and vented to the atmosphere outside the containment vessel for removing heat therefrom. 1 figure.

  20. Reactor core isolation cooling system

    DOEpatents

    Cooke, Franklin E.

    1992-01-01

    A reactor core isolation cooling system includes a reactor pressure vessel containing a reactor core, a drywell vessel, a containment vessel, and an isolation pool containing an isolation condenser. A turbine is operatively joined to the pressure vessel outlet steamline and powers a pump operatively joined to the pressure vessel feedwater line. In operation, steam from the pressure vessel powers the turbine which in turn powers the pump to pump makeup water from a pool to the feedwater line into the pressure vessel for maintaining water level over the reactor core. Steam discharged from the turbine is channeled to the isolation condenser and is condensed therein. The resulting heat is discharged into the isolation pool and vented to the atmosphere outside the containment vessel for removing heat therefrom.

  1. Novel preparation of highly dispersed Ni2P embedded in carbon framework and its improved catalytic performance

    NASA Astrophysics Data System (ADS)

    Wang, Shan; Wang, Kang; Wang, Xitao

    2016-11-01

    Highly dispersed Ni2P embedded in carbon framework with different phosphidation temperature was prepared through carbonizing Ni-alginate gel and followed by phosphidation with PPh3 in liquid phase. The significant effects of phosphidation temperature on Ni2P particle size and catalytic properties for isobutane dehydrogenation to isobutene were investigated. The results showed that Ni2P catalyst derived from the Ni-alginate gel (Ni2P-ADC), consisting of Ni2P particles embedded in carbon walls, possessed smaller particle size and more active site compared with Ni2P catalyst supported on active carbon (Ni2P/AC) prepared by impregnation method. The Ni2P-ADC catalyst phosphorized at 578 K for 3 h exhibited the highest catalytic performance, with the corresponding selectivity of isobutene approaching 89% and conversion approaching 15% after reaction for 4.5 h at 833 K, whereas Ni2P/AC catalyst prepared by impregnation method displays a much lower catalytic activity. The improved catalytic performance of the Ni2P-ADC can be ascribed to the smaller and highly dispersed Ni2P particles incorporated into carbon framework resulting from Ni-alginate gel.

  2. Calculation of Computational Complexity for Radix-2 (p) Fast Fourier Transform Algorithms for Medical Signals.

    PubMed

    Amirfattahi, Rassoul

    2013-10-01

    Owing to its simplicity radix-2 is a popular algorithm to implement fast fourier transform. Radix-2(p) algorithms have the same order of computational complexity as higher radices algorithms, but still retain the simplicity of radix-2. By defining a new concept, twiddle factor template, in this paper, we propose a method for exact calculation of multiplicative complexity for radix-2(p) algorithms. The methodology is described for radix-2, radix-2 (2) and radix-2 (3) algorithms. Results show that radix-2 (2) and radix-2 (3) have significantly less computational complexity compared with radix-2. Another interesting result is that while the number of complex multiplications in radix-2 (3) algorithm is slightly more than radix-2 (2), the number of real multiplications for radix-2 (3) is less than radix-2 (2). This is because of the twiddle factors in the form of which need less number of real multiplications and are more frequent in radix-2 (3) algorithm.

  3. Optoelectronic devices based on MoTe2 p-n junction

    NASA Astrophysics Data System (ADS)

    Bie, Ya-Qing; Heuck, Mikkel; Furchi, Marco; Grosso, Gabriele; Zheng, Jiabao; Cao, Yuan; Navarro-Moratalla, Efren; Englund, Dirk; Jarillo-Herrero, Pablo

    2D transition metal dichalcogenides (2D-TMD), such as MoS2, have been verified with many remarkable physical properties, which include an indirect to direct band transition as a function of thickness and a valley dependent spin polarization. One of the 2D-TMD family members, 2H-MoTe2 has been shown to be a direct bandgap semiconductor as a monolayer and bilayer with a near infrared (NIR) bandgap of about 1.1eV. However, optoelectronic devices based on MoTe2 were so far not experimentally demonstrated. Here, we will present a high on-off ratio MoTe2 p-n junction enabled by a hexagonal boron nitride encapsulation technique. Our study of the MoTe2 p-n junction devices sheds light on designing efficient NIR optoelectronic devices such as photodetectors and energy harvesting cells and light emitters.

  4. PISA: Federated Search in P2P Networks with Uncooperative Peers

    NASA Astrophysics Data System (ADS)

    Ren, Zujie; Shou, Lidan; Chen, Gang; Chen, Chun; Bei, Yijun

    Recently, federated search in P2P networks has received much attention. Most of the previous work assumed a cooperative environment where each peer can actively participate in information publishing and distributed document indexing. However, little work has addressed the problem of incorporating uncooperative peers, which do not publish their own corpus statistics, into a network. This paper presents a P2P-based federated search framework called PISA which incorporates uncooperative peers as well as the normal ones. In order to address the indexing needs for uncooperative peers, we propose a novel heuristic query-based sampling approach which can obtain high-quality resource descriptions from uncooperative peers at relatively low communication cost. We also propose an effective method called RISE to merge the results returned by uncooperative peers. Our experimental results indicate that PISA can provide quality search results, while utilizing the uncooperative peers at a low cost.

  5. Photoionization from the 5p {sup 2}P{sub 3/2} state of rubidium

    SciTech Connect

    Nadeem, Ali; Haq, S. U.

    2011-06-15

    We report two-step photoionization studies from the 5p {sup 2}P{sub 3/2} excited state of rubidium using two dye lasers simultaneously pumped by a common Nd:YAG laser in conjunction with a thermionic diode ion detector. The photoionization cross section at the first ionization threshold is measured as 18.8 {+-} 3 Mb and at excess energies of 0.013, 0.106, 0.229, and 0.329 eV is measured as 15, 13.6, 12.6, and 12.5 Mb, respectively. The measured value of the photoionization cross section at the threshold is used to calibrate the oscillator strengths of the 5p {sup 2}P{sub 3/2}{yields}nd {sup 2}D{sub 5/2} (22 {<=}n{<=} 52) Rydberg transitions.

  6. Hemi bonds and noncovalent interactions in the cational systems (XH2P: SHY)+

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Li, An Yong

    2016-08-01

    Quantum chemistry ab initio MP2 and CCSD calculations were performed to investigate the P⋯S hemi bonds and noncovalent interactions in the radical cational systems (H3P:SH2)+, (FH2P:SH2)+ and (H3P:SHF)+. The hydride dimer (H3P:SH2)+ has a P⋯S hemi bonding structure and a H-bonding structure, (FH2P:SH2)+ has two hemi bonding structures and a proton-transferred H-bonding structure, (H3P:SHF)+ has two hemi bonding structures and three noncovalent structures. It is remarkable that these hemi bonds also have characters of pnicogen and chalcogen bonds. The binding energy, stability and bonding nature of the hemi bonds were presented.

  7. A study of the physical properties of single crystalline Fe5B2P

    NASA Astrophysics Data System (ADS)

    Lamichhane, Tej N.; Taufour, Valentin; Thimmaiah, Srinivasa; Parker, David S.; Bud'ko, Sergey L.; Canfield, Paul C.

    2016-03-01

    Single crystals of Fe5B2P were grown by self-flux growth technique. Structural and electrical and magnetic anisotropic properties are studied. The Curie temperature of Fe5B2P is determined to be 655±2 K. The saturation magnetization is determined to be 1.72 μB/Fe at 2 K. The temperature variation of the anisotropy constant K1 is determined for the first time, reaching ∼ 0.50 MJ/m3 at 2 K, and it is comparable to that of hard ferrites. The saturation magnetization is found to be larger than the hard ferrites. The first principle calculations of saturation magnetization and anisotropy constant are found to be consistent with the experimental results.

  8. Banded transformer cores

    NASA Technical Reports Server (NTRS)

    Mclyman, C. W. T. (Inventor)

    1974-01-01

    A banded transformer core formed by positioning a pair of mated, similar core halves on a supporting pedestal. The core halves are encircled with a strap, selectively applying tension whereby a compressive force is applied to the core edge for reducing the innate air gap. A dc magnetic field is employed in supporting the core halves during initial phases of the banding operation, while an ac magnetic field subsequently is employed for detecting dimension changes occurring in the air gaps as tension is applied to the strap.

  9. Fragmentation of methyl chloride photoexcited near Cl (2p) by mass spectrometry

    NASA Astrophysics Data System (ADS)

    Thissen, Roland; Simon, Marc; Hubin-Franskin, M.-J.

    1994-11-01

    The evolution of the fragmentation pathways of the methylchloride around the Cl 2p edge has been studied by use of charge separation mass spectrometry. Some fragmentation patterns are discussed in the frame of rapid fragmentation of the neutral and dissociation pathways characteristic of singly or multiply charged species. The correlation of the evolution of the charge separation spectra with the initial excitation process is used to give a definitive attribution to the pre-edge features present in the absorption spectrum.

  10. Derivatives of benzimidazole: vasodilator activity of 2-(p-chloro-alpha-hydroxybenzyl)-benzimidazole hydrochloride. Preliminary study.

    PubMed

    Demenge, P; Carraz, G; Luu Duc, C; Silice, C

    1979-01-01

    The effects of 2-(p-chloro-alpha-hydroxybenzyl)-benzimidazole hydrochloride (HBBPC) have been studied in the rabbit and rat. Most of these studies were performed comparatively with reference vasodilators and papaverine. HBBPC vasodilator activity is nearly the same as that of papaverine in the isolated rabbit ear. The characteristic of the vasoactive action of HBBPC seems to reside in its duration. The mechanism of action of HBBPC seems of peripheral type, that is to say it acts on the vascular smooth muscle.

  11. Spin- and angle-resolved spectroscopy of S 2p photoionization in the hydrogen sulfide molecule

    SciTech Connect

    Turri, G.; Snell, G.; Canton, S.E.; Bilodeau, R.C.; Langer, B.; Martins, M.; Kukk, E.; Cherepkov, N.; Bozek, J.D.; Kilcoyne, A.L.; Berrah, N.

    2004-08-01

    Angle- and spin-resolved photoelectron spectroscopy with circularly and linearly polarized synchrotron radiation were used to study the electronic structure of the hydrogen sulfide molecule. A strong effect of the molecular environment appears in the spin-resolved measurements and, although less clearly, in the angular distribution of the sulfur 2p photoelectrons. The anisotropy and spin parameters of the three main spectral components have been obtained. The validity of simple atomic models in explaining the results is discussed.

  12. α and 2p2n emission in fast neutron-induced reactions on Ni60

    DOE PAGES

    Fotiades, N.; Devlin, M.; Haight, R. C.; Nelson, R. O.; Kunieda, S.; Kawano, T.

    2015-06-19

    The cross sections for populating the residual nucleus in the reaction AZX(n,x)A-4Z-2Y exhibit peaks as a function of incident neutron energy corresponding to the (n,n'α) reaction and, at higher energy, to the (n,2p3n) reaction. In addition, the relative magnitudes of these peaks vary with the Z of the target nucleus.

  13. Production and Identification of Wheat-Agropyron cristatum 2P Translocation Lines.

    PubMed

    Li, Huanhuan; Lv, Mingjie; Song, Liqiang; Zhang, Jinpeng; Gao, Ainong; Li, Lihui; Liu, Weihua

    2016-01-01

    Agropyron cristatum (L.) Gaertn. (2n = 28, PPPP), a wild relative of common wheat, possesses many potentially valuable traits that can be transferred to common wheat through breeding programs. The wheat-A. cristatum disomic addition and translocation lines can be used as bridge materials to introduce alien chromosomal segments to wheat. Wheat-A. cristatum 2P disomic addition line II-9-3 was highly resistant to powdery mildew and leaf rust, which was reported in our previous study. However, some translocation lines induced from II-9-3 have not been reported. In this study, some translocation lines were induced from II-9-3 by 60Co-γ irradiation and gametocidal chromosome 2C and then identified by cytological methods. Forty-nine wheat-A. cristatum translocation lines were obtained and various translcoation types were identified by GISH (genomic in situ hybridization), such as whole-arm, segmental and intercalary translocations. Dual-color FISH (fluorescent in situ hybridization) was applied to identify the wheat chromosomes involved in the translocations, and the results showed that A. cristatum 2P chromosome segments were translocated to the different wheat chromosomes, including 1A, 2A, 3A, 4A, 5A, 6A, 7A, 3B, 5B, 7B, 1D, 4D and 6D. Many different types of wheat-A. cristatum alien translocation lines would be valuable for not only identifying and cloning A. cristatum 2P-related genes and understanding the genetics and breeding effects of the translocation between A. cristatum chromosome 2P and wheat chromosomes, but also providing new germplasm resources for the wheat genetic improvement. PMID:26731742

  14. Production and Identification of Wheat-Agropyron cristatum 2P Translocation Lines

    PubMed Central

    Li, Huanhuan; Lv, Mingjie; Song, Liqiang; Zhang, Jinpeng; Gao, Ainong; Li, Lihui; Liu, Weihua

    2016-01-01

    Agropyron cristatum (L.) Gaertn. (2n = 28, PPPP), a wild relative of common wheat, possesses many potentially valuable traits that can be transferred to common wheat through breeding programs. The wheat-A. cristatum disomic addition and translocation lines can be used as bridge materials to introduce alien chromosomal segments to wheat. Wheat-A. cristatum 2P disomic addition line II-9-3 was highly resistant to powdery mildew and leaf rust, which was reported in our previous study. However, some translocation lines induced from II-9-3 have not been reported. In this study, some translocation lines were induced from II-9-3 by 60Co-γ irradiation and gametocidal chromosome 2C and then identified by cytological methods. Forty-nine wheat-A. cristatum translocation lines were obtained and various translcoation types were identified by GISH (genomic in situ hybridization), such as whole-arm, segmental and intercalary translocations. Dual-color FISH (fluorescent in situ hybridization) was applied to identify the wheat chromosomes involved in the translocations, and the results showed that A. cristatum 2P chromosome segments were translocated to the different wheat chromosomes, including 1A, 2A, 3A, 4A, 5A, 6A, 7A, 3B, 5B, 7B, 1D, 4D and 6D. Many different types of wheat-A. cristatum alien translocation lines would be valuable for not only identifying and cloning A. cristatum 2P-related genes and understanding the genetics and breeding effects of the translocation between A. cristatum chromosome 2P and wheat chromosomes, but also providing new germplasm resources for the wheat genetic improvement. PMID:26731742

  15. Elastic, magnetic and electronic properties of iridium phosphide Ir2P.

    PubMed

    Wang, Pei; Wang, Yonggang; Wang, Liping; Zhang, Xinyu; Yu, Xiaohui; Zhu, Jinlong; Wang, Shanmin; Qin, Jiaqian; Leinenweber, Kurt; Chen, Haihua; He, Duanwei; Zhao, Yusheng

    2016-01-01

    Cubic (space group: Fmm) iridium phosphide, Ir2P, has been synthesized at high pressure and high temperature. Angle-dispersive synchrotron X-ray diffraction measurements on Ir2P powder using a diamond-anvil cell at room temperature and high pressures (up to 40.6 GPa) yielded a bulk modulus of B0 = 306(6) GPa and its pressure derivative B0' = 6.4(5). Such a high bulk modulus attributed to the short and strongly covalent Ir-P bonds as revealed by first - principles calculations and three-dimensionally distributed [IrP4] tetrahedron network. Indentation testing on a well-sintered polycrystalline sample yielded the hardness of 11.8(4) GPa. Relatively low shear modulus of ~64 GPa from theoretical calculations suggests a complicated overall bonding in Ir2P with metallic, ionic, and covalent characteristics. In addition, a spin glass behavior is indicated by magnetic susceptibility measurements. PMID:26905444

  16. Elastic, magnetic and electronic properties of iridium phosphide Ir2P

    DOE PAGES

    Wang, Pei; Wang, Yonggang; Wang, Liping; Zhang, Xinyu; Yu, Xiaohui; Zhu, Jinlong; Wang, Shanmin; Qin, Jiaqian; Leinenweber, Kurt; Chen, Haihua; et al

    2016-02-24

    Cubic (space group: Fm3¯m) iridium phosphide, Ir2P, has been synthesized at high pressure and high temperature. Angle-dispersive synchrotron X-ray diffraction measurements on Ir2P powder using a diamond-anvil cell at room temperature and high pressures (up to 40.6 GPa) yielded a bulk modulus of B0 = 306(6) GPa and its pressure derivative B0'= 6.4(5). Such a high bulk modulus attributed to the short and strongly covalent Ir-P bonds as revealed by first – principles calculations and three-dimensionally distributed [IrP4] tetrahedron network. Indentation testing on a well–sintered polycrystalline sample yielded the hardness of 11.8(4) GPa. Relatively low shear modulus of ~64 GPamore » from theoretical calculations suggests a complicated overall bonding in Ir2P with metallic, ionic, and covalent characteristics. Additionally, a spin glass behavior is indicated by magnetic susceptibility measurements.« less

  17. Fragrance material review on 2-(p-Menth-1-ene-10-yl) cyclopentanone.

    PubMed

    Scognamiglio, J; Jones, L; Letizia, C S; Api, A M

    2012-10-01

    A toxicologic and dermatologic review of 2-(p-Menth-1-ene-10-yl) cyclopentanone when used as a fragrance ingredient is presented. 2-(p-Menth-1-ene-10-yl) cyclopentanone is a member of the fragrance structural group ketones cyclopentanones and cyclopentenones. The common characteristic structural element of the group members is a cyclopentanone or cyclopentenone ring with a straight or branched chain alkane or alkene substituent. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-(p-Menth-1-ene-10-yl) cyclopentanone were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, repeated dose, and genotoxicity data. A safety assessment of the entire cyclopentanones and cyclopentenones will be published simultaneously with this document; please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all cyclopentanones and cyclopentenones in fragrances.

  18. Duplication 2p25 in a child with clinical features of CHARGE syndrome.

    PubMed

    Sperry, Ethan D; Schuette, Jane L; van Ravenswaaij-Arts, Conny M A; Green, Glenn E; Martin, Donna M

    2016-05-01

    CHARGE syndrome is a dominant disorder characterized by ocular colobomata, heart defects, choanal atresia, retardation of growth and development, genital hypoplasia, and ear abnormalities including deafness and vestibular disorders. The majority of individuals with CHARGE have pathogenic variants in the gene encoding CHD7, a chromatin remodeling protein. Here, we present a 15-year-old girl with clinical features of CHARGE syndrome and a de novo 6.5 Mb gain of genomic material at 2p25.3-p25.2. The duplicated region contained 24 genes, including the early and broadly expressed transcription factor gene SOX11. Analysis of 28 other patients with CHARGE showed no SOX11 copy number changes or pathogenic sequence variants. To our knowledge, this child's chromosomal abnormality is unique and represents the first co-occurrence of duplication 2p25 and clinical features of CHARGE syndrome. We compare our patient's phenotype to ten previously published patients with isolated terminal duplication 2p, and elaborate on the clinical diagnosis of CHARGE in the context of atypical genetic findings. PMID:26850571

  19. Reevaluation of the O(+)(2P) reaction rate coefficients derived from Atmosphere Explorer C observations

    NASA Technical Reports Server (NTRS)

    Chang, T.; Torr, D. G.; Richards, P. G.; Solomon, S. C.

    1993-01-01

    O(+)(2P) is an important species for studies of the ionosphere and thermosphere: its emission at 7320 A can be used as a diagnostic of the thermospheric atomic oxygen density. Unfortunately, there are no laboratory measurements of the O and N2 reaction rates which are needed to determine the major sinks of (O+)(2p). We have recalculated the O and N2 reaction rates for O(+) (2P) using recent improvements in the solar EUV flux, cross sections, and photoelectron fluxes. For the standard solar EUV flux, the new N2 reaction rate of 3.4 +/- 1.5 x 10 exp -10 cu cm/s is close to the value obtained by Rusch et al. (1977), but the new O reaction rate of 4.0 +/- 1.9 x 10 exp -10 cu cm/sec is about 8 times larger. These new reaction rates are derived using neutral densities, electron density, and solar EUV fluxes measured by Atmosphere Explorer C in 1974 during solar minimum. The new theoretical emission rates are in good agreement with the data for the two orbits studied by Rusch et al.

  20. Elastic, magnetic and electronic properties of iridium phosphide Ir2P

    PubMed Central

    Wang, Pei; Wang, Yonggang; Wang, Liping; Zhang, Xinyu; Yu, Xiaohui; Zhu, Jinlong; Wang, Shanmin; Qin, Jiaqian; Leinenweber, Kurt; Chen, Haihua; He, Duanwei; Zhao, Yusheng

    2016-01-01

    Cubic (space group: Fmm) iridium phosphide, Ir2P, has been synthesized at high pressure and high temperature. Angle-dispersive synchrotron X-ray diffraction measurements on Ir2P powder using a diamond-anvil cell at room temperature and high pressures (up to 40.6 GPa) yielded a bulk modulus of B0 = 306(6) GPa and its pressure derivative B0′ = 6.4(5). Such a high bulk modulus attributed to the short and strongly covalent Ir-P bonds as revealed by first – principles calculations and three-dimensionally distributed [IrP4] tetrahedron network. Indentation testing on a well–sintered polycrystalline sample yielded the hardness of 11.8(4) GPa. Relatively low shear modulus of ~64 GPa from theoretical calculations suggests a complicated overall bonding in Ir2P with metallic, ionic, and covalent characteristics. In addition, a spin glass behavior is indicated by magnetic susceptibility measurements. PMID:26905444

  1. A cooperated P2P GIS for loose coupled governmental application

    NASA Astrophysics Data System (ADS)

    Li, Chenyu; Xie, Kunqing; Ma, Xiujun; Cai, Cuo; Sun, Yanfeng

    2007-06-01

    Current governmental applications are of large scale and always compute-intensive and data-intensive, and we focus on introducing P2P computing to facilitate loose coupled governmental applications in this paper. As GIS data is always deposited in locationally distributed nodes, which are probably administrated under spatial databases, the global range is divided into regions to eliminate complicated consistency maintenance and unnecessary message exchanging, and hierarchical spatial indexes are designed for efficient locating spatial resources and low control cost. When executing, a user submitted global spatial query are firstly parsed to sequential subtasks refer to distributed spatial index, and then dynamically passed to appropriate nodes and cooperatively accomplished. Nodes intercommunicate by cooperating messages, which are sent directly to the destination. Besides collaboration process of sequential execution, a dynamic alternative participant approach for failure handling of the sequential execution is provided, which saves the expensive rollback or abort. And this paper also designed and implemented a p2p based loose governmental application prototype, in which nodes intercommunicate via p2p network sub layer, also a user interface is implemented to manage the request from user and eventually reply a result.

  2. Autoionization study of the Argon 2p satellites excited near the argon 2s threshold

    SciTech Connect

    Wang, H.; Glans, P.; Hemmers, O.

    1997-04-01

    The dynamics of near-threshold photoionization is a complex phenomenon in which the many-electron character of the wavefunctions plays an important role. According to generalized time-independent resonant scattering theory, the transition matrix element from an initial state to a final state is the summation of the amplitudes of direct photoionization and an indirect term in which intermediate states are involved and the resonant behavior is embedded. Studies of the interference effects of intermediate states have been explored in the cases where the direct term is negligible. In the present work, electron time-of-flight spectra of the Ar 2p satellites were measured at two angles (magic and 0{degrees}) in the dipole plane with the exciting photon energy tuned in the vicinity of the Ar 2s threshold. For excitation far below or above the 2s threshold, the 2p satellites spectrum is dominated by 3p to np shakeup contributions upon the ionization of a 2p electron.

  3. Elastic, magnetic and electronic properties of iridium phosphide Ir2P.

    PubMed

    Wang, Pei; Wang, Yonggang; Wang, Liping; Zhang, Xinyu; Yu, Xiaohui; Zhu, Jinlong; Wang, Shanmin; Qin, Jiaqian; Leinenweber, Kurt; Chen, Haihua; He, Duanwei; Zhao, Yusheng

    2016-02-24

    Cubic (space group: Fmm) iridium phosphide, Ir2P, has been synthesized at high pressure and high temperature. Angle-dispersive synchrotron X-ray diffraction measurements on Ir2P powder using a diamond-anvil cell at room temperature and high pressures (up to 40.6 GPa) yielded a bulk modulus of B0 = 306(6) GPa and its pressure derivative B0' = 6.4(5). Such a high bulk modulus attributed to the short and strongly covalent Ir-P bonds as revealed by first - principles calculations and three-dimensionally distributed [IrP4] tetrahedron network. Indentation testing on a well-sintered polycrystalline sample yielded the hardness of 11.8(4) GPa. Relatively low shear modulus of ~64 GPa from theoretical calculations suggests a complicated overall bonding in Ir2P with metallic, ionic, and covalent characteristics. In addition, a spin glass behavior is indicated by magnetic susceptibility measurements.

  4. Cortical regulation of cell size by a sizer cdr2p

    PubMed Central

    Pan, Kally Z; Saunders, Timothy E; Flor-Parra, Ignacio; Howard, Martin; Chang, Fred

    2014-01-01

    Cells can, in principle, control their size by growing to a specified size before commencing cell division. How any cell actually senses its own size remains poorly understood. The fission yeast Schizosaccharomyces pombe are rod-shaped cells that grow to ∼14 µm in length before entering mitosis. In this study, we provide evidence that these cells sense their surface area as part of this size control mechanism. We show that cells enter mitosis at a certain surface area, as opposed to a certain volume or length. A peripheral membrane protein kinase cdr2p has properties of a dose-dependent ‘sizer’ that controls mitotic entry. As cells grow, the local cdr2p concentration in nodes at the medial cortex accumulates as a measure of cell surface area. Our findings, which challenge a previously proposed pom1p gradient model, lead to a new model in which cells sense their size by using cdr2p to probe the surface area over the whole cell and relay this information to the medial cortex. DOI: http://dx.doi.org/10.7554/eLife.02040.001 PMID:24642412

  5. 8-Triazolylpurines: Towards Fluorescent Inhibitors of the MDM2/p53 Interaction.

    PubMed

    Pettersson, Mariell; Bliman, David; Jacobsson, Jimmy; Nilsson, Jesper R; Min, Jaeki; Iconaru, Luigi; Guy, R Kiplin; Kriwacki, Richard W; Andréasson, Joakim; Grøtli, Morten

    2015-01-01

    Small molecule nonpeptidic mimics of α-helices are widely recognised as protein-protein interaction (PPIs) inhibitors. Protein-protein interactions mediate virtually all important regulatory pathways in a cell, and the ability to control and modulate PPIs is therefore of great significance to basic biology, where controlled disruption of protein networks is key to understanding network connectivity and function. We have designed and synthesised two series of 2,6,9-substituted 8-triazolylpurines as α-helix mimetics. The first series was designed based on low energy conformations but did not display any biological activity in a biochemical fluorescence polarisation assay targeting MDM2/p53. Although solution NMR conformation studies demonstrated that such molecules could mimic the topography of an α-helix, docking studies indicated that the same compounds were not optimal as inhibitors for the MDM2/p53 interaction. A new series of 8-triazolylpurines was designed based on a combination of docking studies and analysis of recently published inhibitors. The best compound displayed low micromolar inhibitory activity towards MDM2/p53 in a biochemical fluorescence polarisation assay. In order to evaluate the applicability of these compounds as biologically active and intrinsically fluorescent probes, their absorption/emission properties were measured. The compounds display fluorescent properties with quantum yields up to 50%.

  6. Patient and Community-Level Socio-Demographic Characteristics Associated with Emergency Department Visits for Childhood Injury; A Retrospective Analysis of Data from the Pediatric Emergency Care Applied Research Network (PECARN) Core Data Project 2004–2008

    PubMed Central

    Macy, Michelle L.; Zonfrillo, Mark R.; Cook, Lawrence J.; Funai, Tomohiko; Goldstick, Jason; Stanley, Rachel M.; Chamberlain, James M.; Cunningham, Rebecca M.; Lipton, Robert; Alpern, Elizabeth R.

    2015-01-01

    Objective To examine pediatric emergency department (ED) visits over 5 years, trends in injury severity, and associations between injury-related ED visit outcome and patient and community-level socio-demographic characteristics. Study design Retrospective analysis of administrative data provided to the Pediatric Emergency Care Applied Research Network Core Data Project, 2004–2008. Home addresses were geocoded to determine census block group and associated socio-demographic characteristics. Maximum Abbreviated Injury Scale severity and Severity Classification System scores were calculated. Generalized estimating equations were used to test for associations between socio-demographic characteristics and admission or transfer among injury-related ED visits. Results Overall ED visits and injury-related visits increased from 2004 to 2008 at study sites. Of 2,833,676 successfully geocoded visits, 700,821 (24.7%) were injury-related. The proportion of higher severity injury-related visits remained consistent. Nearly 10% of injury-related visits resulted in admission or transfer each year. After adjusting for age, sex, payer, and injury severity, odds of admission or transfer were lower among minority children and children from areas with moderate and high prevalence of poverty. Conclusions Pediatric injury-related ED visits to included sites increased over the study period while injury severity, anticipated resource utilization, and visit outcomes remained stable, with low rates of admission or transfer. Socio-demographic differences in injury-related visits and ED disposition were apparent. ED-based injury surveillance is essential to understand disparities, inform targets for prevention programs, and reduce the overall burden of childhood injuries. PMID:26141551

  7. Social capital and core network ties: a validation study of individual-level social capital measures and their association with extra- and intra-neighborhood ties, and self-rated health.

    PubMed

    Moore, Spencer; Bockenholt, Ulf; Daniel, Mark; Frohlich, Katherine; Kestens, Yan; Richard, Lucie

    2011-03-01

    Research on social capital and health has assumed that measures of trust, participation, and perceived cohesion capture aspects of people's neighborhood social connections. This study uses data on the personal networks of 2707 Montreal adults in 300 different neighborhoods to examine the association of socio-demographic and social capital variables with the likelihood of having core ties, core neighborhood ties, and high self-rated health (SRH). Persons with higher household income were more likely to have core ties, but less likely to have core neighborhood ties. Persons with greater diversity in extra-neighborhood network capital were more likely to have core ties, and persons with greater diversity in intra-neighborhood network capital were more likely to have core neighborhood ties. Generalized trust, perceived neighborhood cohesion, and extra-neighborhood network diversity were shown associated with high SRH. Conventional measures of social capital may not capture network mechanisms. Findings suggest a critical appraisal of the mechanisms linking social capital and health, and the further delineation of network and psychosocial mechanisms in understanding these links.

  8. HYDRATE CORE DRILLING TESTS

    SciTech Connect

    John H. Cohen; Thomas E. Williams; Ali G. Kadaster; Bill V. Liddell

    2002-11-01

    The ''Methane Hydrate Production from Alaskan Permafrost'' project is a three-year endeavor being conducted by Maurer Technology Inc. (MTI), Noble, and Anadarko Petroleum, in partnership with the U.S. DOE National Energy Technology Laboratory (NETL). The project's goal is to build on previous and ongoing R&D in the area of onshore hydrate deposition. The project team plans to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope includes drilling and coring one well on Anadarko leases in FY 2003 during the winter drilling season. A specially built on-site core analysis laboratory will be used to determine some of the physical characteristics of the hydrates and surrounding rock. Prior to going to the field, the project team designed and conducted a controlled series of coring tests for simulating coring of hydrate formations. A variety of equipment and procedures were tested and modified to develop a practical solution for this special application. This Topical Report summarizes these coring tests. A special facility was designed and installed at MTI's Drilling Research Center (DRC) in Houston and used to conduct coring tests. Equipment and procedures were tested by cutting cores from frozen mixtures of sand and water supported by casing and designed to simulate hydrate formations. Tests were conducted with chilled drilling fluids. Tests showed that frozen core can be washed out and reduced in size by the action of the drilling fluid. Washing of the core by the drilling fluid caused a reduction in core diameter, making core recovery very difficult (if not impossible). One successful solution was to drill the last 6 inches of core dry (without fluid circulation). These tests demonstrated that it will be difficult to capture core when drilling in permafrost or hydrates without implementing certain safeguards. Among the coring tests was a simulated hydrate formation comprised of coarse, large

  9. Dissociation of deep-core-excited CH{sub 3}Cl

    SciTech Connect

    Hansen, D.L.; Martin, R.; Vanderford, B.

    1997-04-01

    Using x-rays from B.L. 9.3.1, a space-focused time-of-flight (TOF) was used to study photofragmentation of CH{sub 3}Cl following excitation in the neighborhood of the Cl K-shell threshold ({approximately} 2.8 keV). Multi-ion coincidence measurements were used to search for selective dissociation of specific bonds in the molecule. Such selectivity has been observed for excitation near outer-core-level thresholds (e.g., Cl 2p), but this is the first study in deep core levels, where very-short core-hole lifetimes and Auger cascade effects may influence fragmentation. Both high-resolution time-of-flight spectroscopy and multi-coincidence photoelectron-photoion-photoion (PE-PIPICO), as well as photoelectron-photoion-photoion-photoion (PE3PICO) measurements were performed. Dramatic changes in the line shapes for different fragment ions are observed as a function of the excitation energy, and are attributed to selective dissociation of the CH{sub 3}Cl molecule along the C-Cl bond. In addition, pronounced angular distributions of the ejected ions are observed on resonance.

  10. 23. CORE WORKER OPERATING A COREBLOWER THAT PNEUMATICALLY FILLED CORE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. CORE WORKER OPERATING A CORE-BLOWER THAT PNEUMATICALLY FILLED CORE BOXES WITH RESIGN IMPREGNATED SAND AND CREATED A CORE THAT THEN REQUIRED BAKING, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  11. Core-Cutoff Tool

    NASA Technical Reports Server (NTRS)

    Gheen, Darrell

    2007-01-01

    A tool makes a cut perpendicular to the cylindrical axis of a core hole at a predetermined depth to free the core at that depth. The tool does not damage the surrounding material from which the core was cut, and it operates within the core-hole kerf. Coring usually begins with use of a hole saw or a hollow cylindrical abrasive cutting tool to make an annular hole that leaves the core (sometimes called the plug ) in place. In this approach to coring as practiced heretofore, the core is removed forcibly in a manner chosen to shear the core, preferably at or near the greatest depth of the core hole. Unfortunately, such forcible removal often damages both the core and the surrounding material (see Figure 1). In an alternative prior approach, especially applicable to toxic or fragile material, a core is formed and freed by means of milling operations that generate much material waste. In contrast, the present tool eliminates the damage associated with the hole-saw approach and reduces the extent of milling operations (and, hence, reduces the waste) associated with the milling approach. The present tool (see Figure 2) includes an inner sleeve and an outer sleeve and resembles the hollow cylindrical tool used to cut the core hole. The sleeves are thin enough that this tool fits within the kerf of the core hole. The inner sleeve is attached to a shaft that, in turn, can be attached to a drill motor or handle for turning the tool. This tool also includes a cutting wire attached to the distal ends of both sleeves. The cutting wire is long enough that with sufficient relative rotation of the inner and outer sleeves, the wire can cut all the way to the center of the core. The tool is inserted in the kerf until its distal end is seated at the full depth. The inner sleeve is then turned. During turning, frictional drag on the outer core pulls the cutting wire into contact with the core. The cutting force of the wire against the core increases with the tension in the wire and

  12. Direct binding of the Kex2p cytosolic tail to the VHS domain of yeast Gga2p facilitates TGN to prevacuolar compartment transport and is regulated by phosphorylation

    PubMed Central

    De, Mithu; Abazeed, Mohamed E.; Fuller, Robert S.

    2013-01-01

    Human Golgi-localized, γ-ear–containing, ADP-ribosylation factor–binding proteins (Ggas) bind directly to acidic dileucine sorting motifs in the cytosolic tails (C-tails) of intracellular receptors. Despite evidence for a role in recruiting ubiquitinated cargo, it remains unclear whether yeast Ggas also function by binding peptide-sorting signals directly. Two-hybrid analysis shows that the Gga1p and Gga2p Vps27, Hrs, Stam (VHS) domains both bind a site in the Kex2p C-tail and that the Gga2p VHS domain binds a site in the Vps10p C-tail. Binding requires deletion of an apparently autoinhibitory sequence in the Gga2p hinge. Ser780 in the Kex2p C-tail is crucial for binding: an Ala substitution blocks but an Asp substitution permits binding. Biochemical assays using purified Gga2p VHS–GGA and TOM1 (GAT) and glutathione S-transferase–Kex2p C-tail fusions show that Gga2p binds directly to the Kex2p C-tail, with relative affinities Asp780 > Ser780 > Ala780. Affinity-purified antibody against a peptide containing phospho-Ser­780 recognizes wild-type Kex2p but not S780A Kex2p, showing that Ser780 is phosphorylated in vivo; phosphorylation of Ser780 is up-regulated by cell wall–damaging drugs. Finally, mutation of Ser780 alters trafficking of Kex2p both in vivo and in cell-free trans-Golgi network (TGN)–prevacuolar compartment (PVC) transport. Thus yeast Gga adaptors facilitate TGN–PVC transport by direct binding of noncanonical phosphoregulated Gga-binding sites in cargo molecules. PMID:23408788

  13. Identifying ELIXIR Core Data Resources

    PubMed Central

    Durinx, Christine; McEntyre, Jo; Appel, Ron; Apweiler, Rolf; Barlow, Mary; Blomberg, Niklas; Cook, Chuck; Gasteiger, Elisabeth; Kim, Jee-Hyub; Lopez, Rodrigo; Redaschi, Nicole; Stockinger, Heinz; Teixeira, Daniel; Valencia, Alfonso

    2016-01-01

    The core mission of ELIXIR is to build a stable and sustainable infrastructure for biological information across Europe. At the heart of this are the data resources, tools and services that ELIXIR offers to the life-sciences community, providing stable and sustainable access to biological data. ELIXIR aims to ensure that these resources are available long-term and that the life-cycles of these resources are managed such that they support the scientific needs of the life-sciences, including biological research. ELIXIR Core Data Resources are defined as a set of European data resources that are of fundamental importance to the wider life-science community and the long-term preservation of biological data. They are complete collections of generic value to life-science, are considered an authority in their field with respect to one or more characteristics, and show high levels of scientific quality and service. Thus, ELIXIR Core Data Resources are of wide applicability and usage. This paper describes the structures, governance and processes that support the identification and evaluation of ELIXIR Core Data Resources. It identifies key indicators which reflect the essence of the definition of an ELIXIR Core Data Resource and support the promotion of excellence in resource development and operation. It describes the specific indicators in more detail and explains their application within ELIXIR’s sustainability strategy and science policy actions, and in capacity building, life-cycle management and technical actions. Establishing the portfolio of ELIXIR Core Data Resources and ELIXIR Services is a key priority for ELIXIR and publicly marks the transition towards a cohesive infrastructure. PMID:27803796

  14. Core sample extractor

    NASA Technical Reports Server (NTRS)

    Akins, James; Cobb, Billy; Hart, Steve; Leaptrotte, Jeff; Milhollin, James; Pernik, Mark

    1989-01-01

    The problem of retrieving and storing core samples from a hole drilled on the lunar surface is addressed. The total depth of the hole in question is 50 meters with a maximum diameter of 100 millimeters. The core sample itself has a diameter of 60 millimeters and will be two meters in length. It is therefore necessary to retrieve and store 25 core samples per hole. The design utilizes a control system that will stop the mechanism at a certain depth, a cam-linkage system that will fracture the core, and a storage system that will save and catalogue the cores to be extracted. The Rod Changer and Storage Design Group will provide the necessary tooling to get into the hole as well as to the core. The mechanical design for the cam-linkage system as well as the conceptual design of the storage device are described.

  15. Accurate ab initio potential energy surface, thermochemistry, and dynamics of the Br(2P, 2P(3∕2)) + CH4 → HBr + CH3 reaction.

    PubMed

    Czakó, Gábor

    2013-04-01

    Chemically accurate full-dimensional non-spin-orbit and spin-orbit (SO) ground-state potential energy surfaces (PESs) are obtained for the Br + CH4 → HBr + CH3 reaction by fitting 21 574 composite ab initio energy points. The composite method considers electron correlation methods up to CCSD(T), basis sets up to aug-cc-pwCVTZ-PP, correlation of the core electrons, scalar relativistic effects via an effective core potential (ECP), and SO corrections, thereby achieving an accuracy better than 0.5 kcal∕mol. Benchmark structures and relative energies are computed for the stationary points using the ab initio focal-point analysis (FPA) scheme based on both ECP and Douglas-Kroll approaches providing all-electron relativistic CCSDT(Q)∕complete-basis-set quality energies. The PESs accurately describe the saddle point of the abstraction reaction and the van der Waals complexes in the entrance and product channels. The SO-corrected PES provides a classical barrier height of 7285(7232 ± 50) cm(-1), De values of 867(799 ± 10) and 399(344 ± 10) cm(-1) for the complexes CH3-HBr and CH3-BrH, respectively, and reaction endothermicity of 7867(7857 ± 50) cm(-1), in excellent agreement with the new, FPA-based benchmark data shown in parentheses. The difference between the Br + CH4 asymptotes of the non-SO and SO PESs is 1240 cm(-1), in good agreement with the experiment (1228 cm(-1)). Quasiclassical trajectory calculations based on more than 13 million trajectories for the late-barrier Br + CH4(vk = 0, 1) [k = 1, 2, 3, 4] reactions show that the vibrational energy, especially the excitation of the stretching modes, activates the reaction much more efficiently than translational energy, in agreement with the extended Polanyi rules. Angular distributions show dominant backward scattering for the ground-state reaction and forward scattering for the stretching-excited reactions. The reactivity on the non-SO PES is about 3-5 times larger than that on the SO PES in a wide

  16. Trx2p-dependent Regulation of Saccharomyces cerevisiae Oxidative Stress Response by the Skn7p Transcription Factor under Respiring Conditions

    PubMed Central

    Gómez-Pastor, Rocío; Garre, Elena; Pérez-Torrado, Roberto; Matallana, Emilia

    2013-01-01

    The whole genome analysis has demonstrated that wine yeasts undergo changes in promoter regions and variations in gene copy number, which make them different to lab strains and help them better adapt to stressful conditions during winemaking, where oxidative stress plays a critical role. Since cytoplasmic thioredoxin II, a small protein with thiol-disulphide oxidoreductase activity, has been seen to perform important functions under biomass propagation conditions of wine yeasts, we studied the involvement of Trx2p in the molecular regulation of the oxidative stress transcriptional response on these strains. In this study, we analyzed the expression levels of several oxidative stress-related genes regulated by either Yap1p or the co-operation between Yap1p and Skn7p. The results revealed a lowered expression for all the tested Skn7p dependent genes in a Trx2p-deficient strain and that Trx2p is essential for the oxidative stress response during respiratory metabolism in wine yeast. Additionally, activity of Yap1p and Skn7p dependent promoters by β-galactosidase assays clearly demonstrated that Skn7p-dependent promoter activation is affected by TRX2 gene deficiency. Finally we showed that deleting the TRX2 gene causes Skn7p hyperphosphorylation under oxidative stress conditions. We propose Trx2p to be a new positive efector in the regulation of the Skn7p transcription factor that controls phosphorylation events and, therefore, modulates the oxidative stress response in yeast. PMID:24376879

  17. Efficient data replication for the delivery of high-quality video content over P2P VoD advertising networks

    NASA Astrophysics Data System (ADS)

    Ho, Chien-Peng; Yu, Jen-Yu; Lee, Suh-Yin

    2011-12-01

    Recent advances in modern television systems have had profound consequences for the scalability, stability, and quality of transmitted digital data signals. This is of particular significance for peer-to-peer (P2P) video-on-demand (VoD) related platforms, faced with an immediate and growing demand for reliable service delivery. In response to demands for high-quality video, the key objectives in the construction of the proposed framework were user satisfaction with perceived video quality and the effective utilization of available resources on P2P VoD networks. This study developed a peer-based promoter to support online advertising in P2P VoD networks based on an estimation of video distortion prior to the replication of data stream chunks. The proposed technology enables the recovery of lost video using replicated stream chunks in real time. Load balance is achieved by adjusting the replication level of each candidate group according to the degree-of-distortion, thereby enabling a significant reduction in server load and increased scalability in the P2P VoD system. This approach also promotes the use of advertising as an efficient tool for commercial promotion. Results indicate that the proposed system efficiently satisfies the given fault tolerances.

  18. Nonadiabatic dynamics in the CH{sub 3}+HCl{yields}CH{sub 4}+Cl({sup 2}P{sub J}) reaction

    SciTech Connect

    Retail, Bertrand; Pearce, Julie K.; Murray, Craig; Orr-Ewing, Andrew J.

    2005-03-08

    Nonadiabatic dynamics in the title reaction have been investigated by 2+1 REMPI detection of the Cl({sup 2}P{sub 3/2}) and Cl{sup *}({sup 2}P{sub 1/2}) products. Reaction was initiated by photodissociation of CH{sub 3}I at 266 nm within a single expansion of a dilute mixture of CH{sub 3}I and HCl in argon, giving a mean collision energy of 7800 cm{sup -1} in the center-of-mass frame. Significant production of Cl* was observed, with careful checks made to ensure that no additional photochemical or inelastic scattering sources of Cl* perturbed the measurements. The fraction of the total yield of Cl({sup 2}P{sub J}) atoms formed in the J=(1/2) level at this collision energy was 0.150{+-}0.024, and must arise from nonadiabatic dynamics because the ground potential energy surface correlates to CH{sub 4}+Cl({sup 2}P{sub 3/2}) products.

  19. Trx2p-dependent regulation of Saccharomyces cerevisiae oxidative stress response by the Skn7p transcription factor under respiring conditions.

    PubMed

    Gómez-Pastor, Rocío; Garre, Elena; Pérez-Torrado, Roberto; Matallana, Emilia

    2013-01-01

    The whole genome analysis has demonstrated that wine yeasts undergo changes in promoter regions and variations in gene copy number, which make them different to lab strains and help them better adapt to stressful conditions during winemaking, where oxidative stress plays a critical role. Since cytoplasmic thioredoxin II, a small protein with thiol-disulphide oxidoreductase activity, has been seen to perform important functions under biomass propagation conditions of wine yeasts, we studied the involvement of Trx2p in the molecular regulation of the oxidative stress transcriptional response on these strains. In this study, we analyzed the expression levels of several oxidative stress-related genes regulated by either Yap1p or the co-operation between Yap1p and Skn7p. The results revealed a lowered expression for all the tested Skn7p dependent genes in a Trx2p-deficient strain and that Trx2p is essential for the oxidative stress response during respiratory metabolism in wine yeast. Additionally, activity of Yap1p and Skn7p dependent promoters by β-galactosidase assays clearly demonstrated that Skn7p-dependent promoter activation is affected by TRX2 gene deficiency. Finally we showed that deleting the TRX2 gene causes Skn7p hyperphosphorylation under oxidative stress conditions. We propose Trx2p to be a new positive efector in the regulation of the Skn7p transcription factor that controls phosphorylation events and, therefore, modulates the oxidative stress response in yeast. PMID:24376879

  20. Highly excited core resonances in photoionization of Fe xvii: Implications for plasma opacities

    SciTech Connect

    Nahar, Sultana N.; Pradhan, Anil K.; Chen Guoxin; Eissner, Werner

    2011-05-15

    A comprehensive study of high-accuracy photoionization cross sections is carried out using the relativistic Breit-Pauli R-matrix (BPRM) method for (h{nu}+Fe xvii {yields} Fe xviii +e). Owing to its importance in high-temperature plasmas, the calculations cover a large energy range, particularly the myriad photoexcitation-of-core (PEC) resonances including the n=3 levels not heretofore considered. The calculations employ a close-coupling wave-function expansion of 60 levels of the core ion Fe xviii ranging over a wide energy range of nearly 900 eV between the n=2 and n=3 levels. Strong-coupling effects due to dipole transition arrays 2p{sup 5}{yields}2p{sup 4}(3s,3d) manifest themselves as large PEC resonances throughout this range and enhance the effective photoionization cross sections orders of magnitude above the background. Comparisons with the erstwhile Opacity Project (OP) and other previous calculations show that the currently available cross sections considerably underestimate the bound-free cross sections. A level-identification scheme is used for spectroscopic designation of the 454 bound fine structure levels of Fe xvii, with n{<=}10, l{<=}9, and 0{<=}J{<=}8 of even and odd parities, obtained using the ab initio BPRM method (compared to 181 LS bound states in the OP work). The calculated energies are compared with those available from the National Institute for Standards and Technology database, which lists 63 levels with very good agreement. Level-specific photoionization cross sections are computed for all levels. In addition, partial cross sections for leaving the core ion Fe xvii in the ground state are also obtained. These results should be relevant to modeling of astrophysical and laboratory plasma sources requiring (i) photoionization rates, (ii) extensive nonlocal-thermodynamic-equilibrium models, (iii) total unified electron-ion recombination rates including radiative and dielectronic recombination, and (iv) plasma opacities. We particularly

  1. The core paradox.

    NASA Technical Reports Server (NTRS)

    Kennedy, G. C.; Higgins, G. H.

    1973-01-01

    Rebuttal of suggestions from various critics attempting to provide an escape from the seeming paradox originated by Higgins and Kennedy's (1971) proposed possibility that the liquid in the outer core was thermally stably stratified and that this stratification might prove a powerful inhibitor to circulation of the outer core fluid of the kind postulated for the generation of the earth's magnetic field. These suggestions are examined and shown to provide no reasonable escape from the core paradox.

  2. Expression of bcl-2, p53 and Ki-67 in arsenical skin cancers.

    PubMed

    Chang, C H; Tsai, R K; Chen, G S; Yu, H S; Chai, C Y

    1998-10-01

    To investigate the regulation of apoptosis and proliferation in arsenic-induced skin cancers, we examined the expression of bcl-2, p53, and Ki-67 using immunohistochemical staining. Thirty patients with Bowen's disease (BD), ten with basal cell carcinoma (BCC), eight with squamous cell carcinoma (SCC) and eleven of perilesional normal skin (PLN) of the non-sun exposure sites from endemic area were examined. The results showed that: 1) bcl-2 was expressed in all of the BCC homogeneously, in none of the SCC, and in 12/30 of the BD focally or homogeneously; 2) p53 was expressed in all of the arsenical skin cancers with a labelling index of 75 +/- 14% of BD, 50 +/- 17% of BCC, 61 +/- 15% of SCC, and also in all of the perilesional normal skin with a labelling index of 55 +/- 24%; 3) Ki-67 was expressed in all of the skin cancers with labelling index of 58 +/- 17% of BD, 12 +/- 7% of BCC, 47 +/- 21% of SCC, and in 9/11 of PLN with a labelling index of 41 +/- 24%. Expression of bcl-2 in BCC or BD is related to the phenotype of germinative basal cell. The constant expression of bcl-2 i early dysplastic cells of BD and the earliest expression of P53 in the basal cells of perilesional normal skin indicate that the initial step of arsenic-induced carcinogenesis is from the basal germinative cells. There is no mutual relationship between bcl-2, p53 or Ki-67 expression in any type of the arsenical skin cancers, but there is a positive correlation between p53 and Ki-67 expression identified in perilesional normal skin. BD had the highest labelling index of p53 and Ki-67.

  3. Affinity Purification and Characterization of a G-Protein Coupled Receptor, Saccharomyces cerevisiae Ste2p

    SciTech Connect

    Lee, Byung-Kwon; Jung, Kyung-Sik; Son, Cagdas D; Kim, Heejung; Verberkmoes, Nathan C; Arshava, Boris; Naider, Fred; Becker, Jeffrey Marvin

    2007-01-01

    We present a rare example of a biologically active G protein coupled receptor (GPCR) whose purity and identity were verified by mass spectrometry after being purified to near homogeneity from its native system. An overexpression vector was constructed to encode the Saccharomyces cerevisiae GPCR -factor receptor (Ste2p, the STE2 gene product) containing a 9-amino acid sequence of rhodopsin that served as an epitope/affinity tag. In the construct, two glycosylation sites and two cysteine residues were removed to aid future structural and functional studies. The receptor was expressed in yeast cells and was detected as a single band in a western blot indicating the absence of glycosylation. Tests of the epitope-tagged, mutated receptor showed it maintained its full biological activity. For extraction of Ste2p, yeast membranes were solubilized with 0.5 % n-dodecyl maltoside (DM). Approximately 120 g of purified -factor receptor was obtained per liter of culture by single-step affinity chromatography using a monoclonal antibody to the rhodopsin epitope. The binding affinity (Kd) of the purified -factor receptor in DM micelles was 28 nM as compared to Kd = 12.7 nM for Ste2p in cell membranes, and approximately 40 % of the purified receptor was correctly folded as judged by ligand saturation binding. About 50 % of the receptor sequence was retrieved from MALDITOF and nanospray mass spectrometry after CNBr digestion of the purified receptor. The methods described will enable structural studies of the -factor receptor and may provide an efficient technique to purify other GPCRs that have been functionally expressed in yeast.

  4. Core-core and core-valence correlation

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1988-01-01

    The effect of 1s core correlation on properties and energy separations are analyzed using full configuration-interaction (FCI) calculations. The Be1S - 1P, the C 3P - 5S,m and CH(+) 1Sigma(+) - 1Pi separations, and CH(+) spectroscopic constants, dipole moment, and 1Sigma(+) - 1Pi transition dipole moment have been studied. The results of the FCI calculations are compared to those obtained using approximate methods.

  5. Wave mixing in nominally undoped Sn2P2S6 at high light intensities

    NASA Astrophysics Data System (ADS)

    Shumelyuk, A.; Wesner, M.; Imlau, M.; Odoulov, S.

    2009-06-01

    The intensity dependence of the photorefractive response of Sn2P2S6 is studied for the Kr+-laser wavelength of 647 nm and pump-beam intensities of up to 10 W/cm2. A considerable enhancement of the two-beam coupling gain factor with increasing intensity at a grating spacing of ≃1 μm is attributed to a light-induced increase of the effective trap density. The large gain reached at high intensities is applied for the build up of a double phase conjugate mirror with a sub-millisecond switch-on time.

  6. Hermès, a collaborative environment at IN2P3

    NASA Astrophysics Data System (ADS)

    Helft, Christian

    2010-04-01

    IN2P3, the institute bringing together HEP laboratories in France, opened a videoconferencing service in 2002 based on an industry standard H323 MCU (Multiple Control Unit). This service has steadily grown since then, serving other French scientific communities in addition to HEP and reaching an average of about thirty conferences a day. The relatively small amount of manpower required to deploy and maintain this facility can be explained by the very sound design and the large array of built-in capabilities offered by the equipment that replaced the original equipment purchased in 2005.

  7. Acoustic and elastic properties of Sn(2)P(2)S(6) crystals.

    PubMed

    Mys, O; Martynyuk-Lototska, I; Grabar, A; Vlokh, R

    2009-07-01

    We present the results concerned with acoustic and elastic properties of Sn(2)P(2)S(6) crystals. The complete matrices of elastic stiffness and compliance coefficients are determined in both the crystallographic coordinate system and the system associated with eigenvectors of the elastic stiffness tensor. The acoustic slowness surfaces are constructed and the propagation and polarization directions of the slowest acoustic waves promising for acousto-optic interactions are determined on this basis. The acoustic obliquity angle and the deviation of polarization of the acoustic waves from purely transverse or longitudinal states are quantitatively analysed.

  8. Electron-phonon interaction and superconductivity in BaIr2P2.

    PubMed

    Billington, D

    2016-10-01

    Detailed calculations of the electronic structure, phonons and electron-phonon coupling of the superconducting compound BaIr2P2 were performed from first-principles. The electronic structure showed excellent agreement with the available experimental data. The total electron-phonon coupling constant was [Formula: see text] and the logarithmically averaged phonon frequency was [Formula: see text] K. From the Allen-Dynes formula, with [Formula: see text], the superconducting critical temperature was estimated to be [Formula: see text] K, which is in excellent agreement with the experiment. These results indicate that the electron-phonon coupling is of moderate strength and is easily capable of supporting the observed superconductivity.

  9. Towards accurate node-based detection of P2P botnets.

    PubMed

    Yin, Chunyong

    2014-01-01

    Botnets are a serious security threat to the current Internet infrastructure. In this paper, we propose a novel direction for P2P botnet detection called node-based detection. This approach focuses on the network characteristics of individual nodes. Based on our model, we examine node's flows and extract the useful features over a given time period. We have tested our approach on real-life data sets and achieved detection rates of 99-100% and low false positives rates of 0-2%. Comparison with other similar approaches on the same data sets shows that our approach outperforms the existing approaches.

  10. The Measurement and Modeling of a P2P Streaming Video Service

    NASA Astrophysics Data System (ADS)

    Gao, Peng; Liu, Tao; Chen, Yanming; Wu, Xingyao; El-Khatib, Yehia; Edwards, Christopher

    Most of the work on grid technology in video area has been generally restricted to aspects of resource scheduling and replica management. The traffic of such service has a lot of characteristics in common with that of the traditional video service. However the architecture and user behavior in Grid networks are quite different from those of traditional Internet. Considering the potential of grid networks and video sharing services, measuring and analyzing P2P IPTV traffic are important and fundamental works in the field grid networks.

  11. Electronic Structure and Phase Transition in Ferroelectic Sn2P2S6 Crystal

    PubMed Central

    Glukhov, Konstantin; Fedyo, Kristina; Banys, Juras; Vysochanskii, Yulian

    2012-01-01

    An analysis of the P2S6 cluster electronic structure and its comparison with the crystal valence band in the paraelectric and ferroelectric phases has been done by first-principles calculations for Sn2P2S6 ferroelectrics. The origin of ferroelectricity has been outlined. It was established that the spontaneous polarization follows from the stereochemical activity of the electron lone pair of tin cations, which is determined by hybridization with P2S6 molecular orbitals. The chemical bonds covalence increase and rearrangement are related to the valence band changes at transition from the paraelectric phase to the ferroelectric phase. PMID:23203069

  12. Towards Accurate Node-Based Detection of P2P Botnets

    PubMed Central

    2014-01-01

    Botnets are a serious security threat to the current Internet infrastructure. In this paper, we propose a novel direction for P2P botnet detection called node-based detection. This approach focuses on the network characteristics of individual nodes. Based on our model, we examine node's flows and extract the useful features over a given time period. We have tested our approach on real-life data sets and achieved detection rates of 99-100% and low false positives rates of 0–2%. Comparison with other similar approaches on the same data sets shows that our approach outperforms the existing approaches. PMID:25089287

  13. A 2-substituted prodiginine, 2-(p-hydroxybenzyl)prodigiosin, from Pseudoalteromonas rubra.

    PubMed

    Fehér, Domonkos; Barlow, Russell S; Lorenzo, Patricia S; Hemscheidt, Thomas K

    2008-11-01

    In the course of work aimed at the discovery of new pharmaceutical lead compounds from marine bacteria, a lipophilic extract of the bacterium Pseudoalteromonas rubra displayed significant cytotoxicity against SKOV-3, a human ovarian adenocarcinoma cell line. Bioassay-directed fractionation of this extract resulted in the isolation of a series of known and new prodiginine-type azafulvenes. The structure of the major metabolite was elucidated by interpretation of spectroscopic data as a 2-substituted prodigiosin, which we named 2-(p-hydroxybenzyl)prodigiosin (HBPG).

  14. AN Core Analysis

    NASA Astrophysics Data System (ADS)

    Barbarino, Andrea; Tomatis, Daniele

    2014-06-01

    Several alternative approximations of neutron transport have been proposed in years to move around the known limitations imposed by neutron diffusion in the modeling of nuclear cores. However, only a few complied with the industrial requirements of fast numerical computation, concentrating more on physical accuracy. In this work, the AN transport methodology is discussed with particular interest in core performance calculations. The implementation of the methodology in full core codes is discussed with particular attention to numerical issues and to the integration within the entire simulation process. Finally, first results from core studies in AN transport are analyzed in detail and compared to standard results of neutron diffusion.

  15. Core Research Center

    USGS Publications Warehouse

    Hicks, Joshua; Adrian, Betty

    2009-01-01

    The Core Research Center (CRC) of the U.S. Geological Survey (USGS), located at the Denver Federal Center in Lakewood, Colo., currently houses rock core from more than 8,500 boreholes representing about 1.7 million feet of rock core from 35 States and cuttings from 54,000 boreholes representing 238 million feet of drilling in 28 States. Although most of the boreholes are located in the Rocky Mountain region, the geologic and geographic diversity of samples have helped the CRC become one of the largest and most heavily used public core repositories in the United States. Many of the boreholes represented in the collection were drilled for energy and mineral exploration, and many of the cores and cuttings were donated to the CRC by private companies in these industries. Some cores and cuttings were collected by the USGS along with other government agencies. Approximately one-half of the cores are slabbed and photographed. More than 18,000 thin sections and a large volume of analytical data from the cores and cuttings are also accessible. A growing collection of digital images of the cores are also becoming available on the CRC Web site Internet http://geology.cr.usgs.gov/crc/.

  16. A Small Conserved Domain in the Yeast Spa2p Is Necessary and Sufficient for Its Polarized Localization

    PubMed Central

    Arkowitz, Robert A.; Lowe, Nick

    1997-01-01

    SPA2 encodes a yeast protein that is one of the first proteins to localize to sites of polarized growth, such as the shmoo tip and the incipient bud. The dynamics and requirements for Spa2p localization in living cells are examined using Spa2p green fluorescent protein fusions. Spa2p localizes to one edge of unbudded cells and subsequently is observable in the bud tip. Finally, during cytokinesis Spa2p is present as a ring at the mother–daughter bud neck. The bud emergence mutants bem1 and bem2 and mutants defective in the septins do not affect Spa2p localization to the bud tip. Strikingly, a small domain of Spa2p comprised of 150 amino acids is necessary and sufficient for localization to sites of polarized growth. This localization domain and the amino terminus of Spa2p are essential for its function in mating. Searching the yeast genome database revealed a previously uncharacterized protein which we name, Sph1p (Spa2p homolog), with significant homology to the localization domain and amino terminus of Spa2p. This protein also localizes to sites of polarized growth in budding and mating cells. SPH1, which is similar to SPA2, is required for bipolar budding and plays a role in shmoo formation. Overexpression of either Spa2p or Sph1p can block the localization of either protein fused to green fluorescent protein, suggesting that both Spa2p and Sph1p bind to and are localized by the same component. The identification of a 150–amino acid domain necessary and sufficient for localization of Spa2p to sites of polarized growth and the existence of this domain in another yeast protein Sph1p suggest that the early localization of these proteins may be mediated by a receptor that recognizes this small domain. PMID:9214378

  17. Investigating the relationship between k-core and s-core network decompositions

    NASA Astrophysics Data System (ADS)

    Eidsaa, Marius; Almaas, Eivind

    2016-05-01

    Network decomposition methods, such as the much used k-core analysis, are able to identify globally central regions of networks. The decomposition approaches are hierarchical and identify nested sets of nodes with increasing centrality properties. While most studies have been concerned with unweighted networks, i.e. k-core analysis, recent works have introduced network decomposition methods that apply to weighted networks. Here, we investigate the relationship between k-core decomposition for unweighted networks and s-core decomposition for weighted networks by systematically employing a link-weight scheme that gradually discretizes the link weights. We applied this approach to the Erdős-Rényi model and the scale-free configuration model for five different weight distributions, and two empirical networks, the US air traffic network and a Facebook network. We find that (1) both uniformly random and positively correlated link-weight distributions give rise to highly stable s-core decompositions with respect to discretization levels. (2) For negatively correlated link-weight distributions, the resulting s-core decomposition has no similarity to the k-cores. Since several combinations of network topology and link-weight distributions give rise to a core-structure that is highly similar to the full s-core for a large range of link-discretization levels, it is possible to significantly speed up the numerical s-core analysis for these situations.

  18. Can Psychiatric Rehabilitation Be Core to CORE?

    ERIC Educational Resources Information Center

    Olney, Marjorie F.; Gill, Kenneth J.

    2016-01-01

    Purpose: In this article, we seek to determine whether psychiatric rehabilitation principles and practices have been more fully incorporated into the Council on Rehabilitation Education (CORE) standards, the extent to which they are covered in four rehabilitation counseling "foundations" textbooks, and how they are reflected in the…

  19. The fluffy core of Enceladus

    NASA Astrophysics Data System (ADS)

    Roberts, James H.

    2015-09-01

    Enceladus is well known for its young south polar terrain, observed by Cassini to emit several GW of heat as well as plumes of vapor and ice. The source of this energy is believed to be tidal dissipation. However, the observed south polar heat flux cannot be sustained over the age of the Solar System. Furthermore, thermal evolution models suggest that any global subsurface ocean should freeze on a timescale of tens to hundreds of My, sharply reducing future tidal heating, unless large amounts of antifreeze are present in the ocean. Here I propose an alternative internal structure for Enceladus, in which the silicate core is fragmented, and that the tidal deformation of the core may be partially controlled by interstitial ice. I find that fragmentation of the core increases tidal dissipation by a factor of 20, consistent with the long-term dynamically sustainable level, even when the interior is completely frozen, but only if the interior starts out warm and tidal heating is strong from the beginning. If this is not the case, radioactive heating will be insufficient to prevent the interior from cooling. Although an ocean need not be present in order for the interior to experience significant tidal heating, all models that dissipate enough heat to prevent runaway cooling are also warm enough to have an ocean. Tidal dissipation in the weak core provides an additional source of heat that may prevent a global subsurface ocean from freezing.

  20. Research on Robustness of Tree-based P2P Streaming

    NASA Astrophysics Data System (ADS)

    Chu, Chen; Yan, Jinyao; Ding, Kuangzheng; Wang, Xi

    Research on P2P streaming media is a hot topic in the area of Internet technology. It has emerged as a promising technique. This new paradigm brings a number of unique advantages such as scalability, resilience and also effectiveness in coping with dynamics and heterogeneity. However, There are also many problems in P2P streaming media systems using traditional tree-based topology such as the bandwidth limits between parents and child nodes; node's joining or leaving has a great effect on robustness of tree-based topology. This paper will introduce a method of measuring the robustness of tree-based topology: using network measurement, we observe and record the bandwidth between all the nodes, analyses the correlation between all the sibling flows, measure the robustness of tree-based topology. And the result shows that in the Tree-based topology, the different links which have similar routing paths would share the bandwidth bottleneck, reduce the robustness of the Tree-based topology.

  1. Pressure Induced Enhancement of Superconductivity in LaRu2P2

    NASA Astrophysics Data System (ADS)

    Li, Baoxuan; Lu, Pengchao; Liu, Jianzhong; Sun, Jian; Li, Sheng; Zhu, Xiyu; Wen, Hai-Hu

    2016-04-01

    To explore new superconductors beyond the copper-based and iron-based systems is very important. The Ru element locates just below the Fe in the periodic table and behaves like the Fe in many ways. One of the common thread to induce high temperature superconductivity is to introduce moderate correlation into the system. In this paper, we report the significant enhancement of superconducting transition temperature from 3.8 K to 5.8 K by using a pressure only of 1.74 ± 0.05 GPa in LaRu2P2 which has an iso-structure of the iron-based 122 superconductors. The ab-initio calculation shows that the superconductivity in LaRu2P2 at ambient pressure can be explained by the McMillan’s theory with strong electron-phonon coupling. However, it is difficult to interpret the enhancement of Tc versus pressure within this picture. Detailed analysis of the pressure induced evolution of resistivity and upper critical field Hc2(T) reveals that the increase of Tc with pressure may be accompanied by the involvement of extra electron-boson interaction. This suggests that the Ru-based system has some commonality as the Fe-based superconductors.

  2. Pressure Induced Enhancement of Superconductivity in LaRu2P2.

    PubMed

    Li, Baoxuan; Lu, Pengchao; Liu, Jianzhong; Sun, Jian; Li, Sheng; Zhu, Xiyu; Wen, Hai-Hu

    2016-01-01

    To explore new superconductors beyond the copper-based and iron-based systems is very important. The Ru element locates just below the Fe in the periodic table and behaves like the Fe in many ways. One of the common thread to induce high temperature superconductivity is to introduce moderate correlation into the system. In this paper, we report the significant enhancement of superconducting transition temperature from 3.8 K to 5.8 K by using a pressure only of 1.74 ± 0.05 GPa in LaRu2P2 which has an iso-structure of the iron-based 122 superconductors. The ab-initio calculation shows that the superconductivity in LaRu2P2 at ambient pressure can be explained by the McMillan's theory with strong electron-phonon coupling. However, it is difficult to interpret the enhancement of Tc versus pressure within this picture. Detailed analysis of the pressure induced evolution of resistivity and upper critical field Hc2(T) reveals that the increase of Tc with pressure may be accompanied by the involvement of extra electron-boson interaction. This suggests that the Ru-based system has some commonality as the Fe-based superconductors. PMID:27086696

  3. Secular variation of activity in comets 2P/Encke and 9P/Tempel 1

    NASA Technical Reports Server (NTRS)

    Haken, Michael; AHearn, Michael F.; Feldman, Paul D.; Budzien, Scott A.

    1995-01-01

    We compare production rates of H20 derived from International Ultraviolet Explorer (IUE) spectra from multiple apparitions of 2 comets, 2P/Encke and 9P/Tempel 1, whose orbits are in near-resonance with that of the Earth. Since model-induced errors are primarily a function of observing geometry, the close geometrical matches afforded by the resonance condition results in the cancellation of such errors when taking ratios of production rates. Giving careful attention to the variation of model parameters with solar activity, we find marginal evidence of change in 2P/Encke: a 1-sigma pre-perihelion decrease averaging 4%/revolution over 4 apparitions from 1980-1994, and a 1-sigma post-perihelion increase of 16%/revolution for 2 successive apparitions in 1984 and 1987. We find for 9P/Tempel 1, however, a 7-sigma decrease of 29%/revolution over 3 apparitions from 1983-1994, even after correcting for a tracking problem which made the fluxes systematically low. We speculate on a possible association of the character of long-term brightness variations with physical properties of the nucleus, and discuss implications for future research.

  4. Pressure Induced Enhancement of Superconductivity in LaRu2P2.

    PubMed

    Li, Baoxuan; Lu, Pengchao; Liu, Jianzhong; Sun, Jian; Li, Sheng; Zhu, Xiyu; Wen, Hai-Hu

    2016-04-18

    To explore new superconductors beyond the copper-based and iron-based systems is very important. The Ru element locates just below the Fe in the periodic table and behaves like the Fe in many ways. One of the common thread to induce high temperature superconductivity is to introduce moderate correlation into the system. In this paper, we report the significant enhancement of superconducting transition temperature from 3.8 K to 5.8 K by using a pressure only of 1.74 ± 0.05 GPa in LaRu2P2 which has an iso-structure of the iron-based 122 superconductors. The ab-initio calculation shows that the superconductivity in LaRu2P2 at ambient pressure can be explained by the McMillan's theory with strong electron-phonon coupling. However, it is difficult to interpret the enhancement of Tc versus pressure within this picture. Detailed analysis of the pressure induced evolution of resistivity and upper critical field Hc2(T) reveals that the increase of Tc with pressure may be accompanied by the involvement of extra electron-boson interaction. This suggests that the Ru-based system has some commonality as the Fe-based superconductors.

  5. Cooperation enhanced by indirect reciprocity in spatial prisoner's dilemma games for social P2P systems

    NASA Astrophysics Data System (ADS)

    Tian, Lin-Lin; Li, Ming-Chu; Wang, Zhen

    2016-11-01

    With the growing interest in social Peer-to-Peer (P2P) applications, relationships of individuals are further exploited to improve the performances of reputation systems. It is an on-going challenge to investigate how spatial reciprocity aids indirect reciprocity in sustaining cooperation in practical P2P environments. This paper describes the construction of an extended prisoner's dilemma game on square lattice networks with three strategies, i.e., defection, unconditional cooperation, and reciprocal cooperation. Reciprocators discriminate partners according to their reputations based on image scoring, where mistakes in judgment of reputations may occur. The independent structures of interaction and learning neighborhood are discussed, with respect to the situation in which learning environments differ from interaction networks. The simulation results have indicated that the incentive mechanism enhances cooperation better in structured peers than among a well-mixed population. Given the realistic condition of inaccurate reputation scores, defection is still successfully held down when the players interact and learn within the unified neighborhoods. Extensive simulations have further confirmed the positive impact of spatial structure on cooperation with different sizes of lattice neighborhoods. And similar conclusions can also be drawn on regular random networks and scale-free networks. Moreover, for the separated structures of the neighborhoods, the interaction network has a critical effect on the evolution dynamics of cooperation and learning environments only have weaker impacts on the process. Our findings further provide some insights concerning the evolution of collective behaviors in social systems.

  6. Ferromagnetism in the Kondo-lattice compound CePd2P2.

    PubMed

    Tran, Vinh Hung; Bukowski, Zbigniew

    2014-06-25

    We report physical properties of CePd2P2 crystallizing in the tetragonal ThCr2Si2-type structure (space group I4/mmm). Dc-magnetic susceptibility, magnetization, specific heat, electrical resistivity and magnetoresistance measurements establish a ferromagnetic ordering below the Curie temperature TC = 28.4 ± 0.2 K. Critical analysis of isothermal and isofield magnetization yields critical exponents of β = 0.405 ± 0.005, γ = 1.11 ± 0.05 and δ = 3.74 ± 0.04. The ordered state is characterized by saturation moment Ms ∼ 0.98μB and magnon energy gap Δ/kB ∼25–35 K. The studied properties reflect a competing influence of the Kondo and crystalline electric field (CEF) interactions. The strength of the Kondo effect is assigned by a low-temperature Kondo scale TK ∼19 ± 10 K and a high-temperature Kondo scale TK ~ H 117 } 10 K. A model of the inelastic scattering of the conduction electrons with an exchanged CEF energy ΔCEF was applied to the magnetic resistivity. An average value ΔCEF = 260 ± 30 K is consistent in the relationships with TK and TK H. We argue that the CePd2P2 compound appears to be a new ferromagnetic Kondo-lattice among the Ce-based intermetallics.

  7. PROMINENCE THREAD SEISMOLOGY USING THE P{sub 1}/2P{sub 2} RATIO

    SciTech Connect

    DIaz, A. J.; Oliver, R.; Ballester, J. L. E-mail: ramon.oliver@uib.e

    2010-12-20

    Prominence threads are expected to be cold plasma condensations in a long magnetic tube. Because of this density inhomogeneity along the magnetic field, the ratio of the fundamental transverse mode period to twice that of its first overtone, P{sub 1}/2P{sub 2}, must differ from 1. We investigate the dependence of this ratio on the equilibrium parameters of prominence threads and its possible use as a diagnostic tool for prominence seismology. Using the low-beta plasma approximation, we follow the procedure of previous works to obtain the frequencies and spatial distribution of the modes. We also check the thin tube approximation and find it reasonably accurate. The period ratio P{sub 1}/2P{sub 2} is found to be greater than unity, in contrast with coronal loops, for which the effect of inhomogeneities is to make this ratio smaller than 1. The ratio is very sensitive to the thread length, while the dependence on other parameters is less important for threads than for coronal loops. Hence, the period ratio can be used to obtain an estimation of the length of the supporting magnetic tube, since the thread length is known from observations. The obtained value of the tube length does not depend on other parameters, so their potential for prominence seismology may be great.

  8. The family of K2P channels: salient structural and functional properties

    PubMed Central

    Feliciangeli, Sylvain; Chatelain, Frank C; Bichet, Delphine; Lesage, Florian

    2015-01-01

    Potassium channels participate in many biological functions, from ion homeostasis to generation and modulation of the electrical membrane potential. They are involved in a large variety of diseases. In the human genome, 15 genes code for K+ channels with two pore domains (K2P). These channels form dimers of pore-forming subunits that produce background conductances finely regulated by a range of natural and chemical effectors, including signalling lipids, temperature, pressure, pH, antidepressants and volatile anaesthetics. Since the cloning of TWIK1, the prototypical member of this family, a lot of work has been carried out on their structure and biology. These studies are still in progress, but data gathered so far show that K2P channels are central players in many processes, including ion homeostasis, hormone secretion, cell development and excitability. A growing number of studies underline their implication in physiopathological mechanisms, such as vascular and pulmonary hypertension, cardiac arrhythmias, nociception, neuroprotection and depression. This review gives a synthetic view of the most noticeable features of these channels. PMID:25530075

  9. Incentive Mechanism for P2P Content Sharing over Heterogenous Access Networks

    NASA Astrophysics Data System (ADS)

    Sato, Kenichiro; Hashimoto, Ryo; Yoshino, Makoto; Shinkuma, Ryoichi; Takahashi, Tatsuro

    In peer-to-peer (P2P) content sharing, users can share their content by contributing their own resources to one another. However, since there is no incentive for contributing contents or resources to others, users may attempt to obtain content without any contribution. To motivate users to contribute their resources to the service, incentive-rewarding mechanisms have been proposed. On the other hand, emerging wireless technologies, such as IEEE 802.11 wireless local area networks, beyond third generation (B3G) cellular networks and mobile WiMAX, provide high-speed Internet access for wireless users. Using these high-speed wireless access, wireless users can use P2P services and share their content with other wireless users and with fixed users. However, this diversification of access networks makes it difficult to appropriately assign rewards to each user according to their contributions. This is because the cost necessary for contribution is different in different access networks. In this paper, we propose a novel incentive-rewarding mechanism called EMOTIVER that can assign rewards to users appropriately. The proposed mechanism uses an external evaluator and interactive learning agents. We also investigate a way of appropriately controlling rewards based on the system service's quality and managing policy.

  10. Nanostructured Ni2 P as a Robust Catalyst for the Hydrolytic Dehydrogenation of Ammonia-Borane.

    PubMed

    Peng, Cheng-Yun; Kang, Lei; Cao, Shuang; Chen, Yong; Lin, Zhe-Shuai; Fu, Wen-Fu

    2015-12-21

    Ammonia-borane (AB) is a promising chemical hydrogen-storage material. However, the development of real-time, efficient, controllable, and safe methods for hydrogen release under mild conditions is a challenge in the large-scale use of hydrogen as a long-term solution for future energy security. A new class of low-cost catalytic system is presented that uses nanostructured Ni2 P as catalyst, which exhibits excellent catalytic activity and high sustainability toward hydrolysis of ammonia-borane with the initial turnover frequency of 40.4 mol(H2)  mol(Ni2P) (-1)  min(-1) under air atmosphere and at ambient temperature. This value is higher than those reported for noble-metal-free catalysts, and the obtained Arrhenius activation energy (Ea =44.6 kJ mol(-1) ) for the hydrolysis reaction is comparable to Ru-based bimetallic catalysts. A clearly mechanistic analysis of the hydrolytic reaction of AB based on experimental results and a density functional theory calculation is presented. PMID:26545954

  11. A P2P Framework for Developing Bioinformatics Applications in Dynamic Cloud Environments.

    PubMed

    Lin, Chun-Hung Richard; Wen, Chun-Hao; Lin, Ying-Chih; Tung, Kuang-Yuan; Lin, Rung-Wei; Lin, Chun-Yuan

    2013-01-01

    Bioinformatics is advanced from in-house computing infrastructure to cloud computing for tackling the vast quantity of biological data. This advance enables large number of collaborative researches to share their works around the world. In view of that, retrieving biological data over the internet becomes more and more difficult because of the explosive growth and frequent changes. Various efforts have been made to address the problems of data discovery and delivery in the cloud framework, but most of them suffer the hindrance by a MapReduce master server to track all available data. In this paper, we propose an alternative approach, called PRKad, which exploits a Peer-to-Peer (P2P) model to achieve efficient data discovery and delivery. PRKad is a Kademlia-based implementation with Round-Trip-Time (RTT) as the associated key, and it locates data according to Distributed Hash Table (DHT) and XOR metric. The simulation results exhibit that our PRKad has the low link latency to retrieve data. As an interdisciplinary application of P2P computing for bioinformatics, PRKad also provides good scalability for servicing a greater number of users in dynamic cloud environments.

  12. Rotavirus G2P[4] detection in fresh vegetables and oysters in Mexico City.

    PubMed

    Quiroz-Santiago, Carolina; Vázquez-Salinas, Carlos; Natividad-Bonifacio, Ivan; Barrón-Romero, Blanca Lilia; Quiñones-Ramírez, Elsa Irma

    2014-11-01

    Rotaviruses are the principal cause of dehydration caused by diarrhea in children younger than 2 years of age. Although these viral infections have mainly been associated with ingestion of fecally contaminated food and water, few studies have addressed the presence of the virus in food that is consumed raw or slightly cooked. In this work, 30 oyster samples and 33 vegetable samples were examined for the presence of rotavirus genotypes to evaluate their potential to produce gastrointestinal infections. The rotaviruses were identified by reverse transcriptase PCR amplification of the VP7 gene. G and P genotyping was also performed by reverse transcriptase PCR, with a detection sensitivity of up to 15 PFU/ml. Rotaviruses were found in 17 (26.9%) of 63 samples (10 oysters and 7 vegetables). The G2 genotype was found in 11 (64.7%) of 17 of the rotavirus strains, and 16 (94.1%) of 17 had the P[4] genotype. The combined genotypes found most frequently were G2P[4] (10 [58.82%] of 17), GNTP[4] (6 [35.29%] of 17), and G2P[NT] (1 [5.8%] of 17).

  13. TASK-2: a K2P K+ channel with complex regulation and diverse physiological functions

    PubMed Central

    Cid, L. Pablo; Roa-Rojas, Hugo A.; Niemeyer, María I.; González, Wendy; Araki, Masatake; Araki, Kimi; Sepúlveda, Francisco V.

    2013-01-01

    TASK-2 (K2P5.1) is a two-pore domain K+ channel belonging to the TALK subgroup of the K2P family of proteins. TASK-2 has been shown to be activated by extra- and intracellular alkalinization. Extra- and intracellular pH-sensors reside at arginine 224 and lysine 245 and might affect separate selectivity filter and inner gates respectively. TASK-2 is modulated by changes in cell volume and a regulation by direct G-protein interaction has also been proposed. Activation by extracellular alkalinization has been associated with a role of TASK-2 in kidney proximal tubule bicarbonate reabsorption, whilst intracellular pH-sensitivity might be the mechanism for its participation in central chemosensitive neurons. In addition to these functions TASK-2 has been proposed to play a part in apoptotic volume decrease in kidney cells and in volume regulation of glial cells and T-lymphocytes. TASK-2 is present in chondrocytes of hyaline cartilage, where it is proposed to play a central role in stabilizing the membrane potential. Additional sites of expression are dorsal root ganglion neurons, endocrine and exocrine pancreas and intestinal smooth muscle cells. TASK-2 has been associated with the regulation of proliferation of breast cancer cells and could become target for breast cancer therapeutics. Further work in native tissues and cells together with genetic modification will no doubt reveal the details of TASK-2 functions that we are only starting to suspect. PMID:23908634

  14. Pressure Induced Enhancement of Superconductivity in LaRu2P2

    PubMed Central

    Li, Baoxuan; Liu, Jianzhong; Sun, Jian; Li, Sheng; Zhu, Xiyu; Wen, Hai-Hu

    2016-01-01

    To explore new superconductors beyond the copper-based and iron-based systems is very important. The Ru element locates just below the Fe in the periodic table and behaves like the Fe in many ways. One of the common thread to induce high temperature superconductivity is to introduce moderate correlation into the system. In this paper, we report the significant enhancement of superconducting transition temperature from 3.8 K to 5.8 K by using a pressure only of 1.74 ± 0.05 GPa in LaRu2P2 which has an iso-structure of the iron-based 122 superconductors. The ab-initio calculation shows that the superconductivity in LaRu2P2 at ambient pressure can be explained by the McMillan’s theory with strong electron-phonon coupling. However, it is difficult to interpret the enhancement of Tc versus pressure within this picture. Detailed analysis of the pressure induced evolution of resistivity and upper critical field Hc2(T) reveals that the increase of Tc with pressure may be accompanied by the involvement of extra electron-boson interaction. This suggests that the Ru-based system has some commonality as the Fe-based superconductors. PMID:27086696

  15. Polymodal activation of the TREK-2 K2P channel produces structurally distinct open states.

    PubMed

    McClenaghan, Conor; Schewe, Marcus; Aryal, Prafulla; Carpenter, Elisabeth P; Baukrowitz, Thomas; Tucker, Stephen J

    2016-06-01

    The TREK subfamily of two-pore domain (K2P) K(+) channels exhibit polymodal gating by a wide range of physical and chemical stimuli. Crystal structures now exist for these channels in two main states referred to as the "up" and "down" conformations. However, recent studies have resulted in contradictory and mutually exclusive conclusions about the functional (i.e., conductive) status of these two conformations. To address this problem, we have used the state-dependent TREK-2 inhibitor norfluoxetine that can only bind to the down state, thereby allowing us to distinguish between these two conformations when activated by different stimuli. Our results reconcile these previously contradictory gating models by demonstrating that activation by pressure, temperature, voltage, and pH produce more than one structurally distinct open state and reveal that channel activation does not simply involve switching between the up and down conformations. These results also highlight the diversity of structural mechanisms that K2P channels use to integrate polymodal gating signals. PMID:27241700

  16. CCQE, 2p2h excitations and ν—energy reconstruction

    SciTech Connect

    Nieves, J.; Simo, I. Ruiz; Sánchez, F.; Vacas, M. J. Vicente

    2015-05-15

    We analyze the MiniBooNE muon neutrino CCQE-like dσ/dT{sub μ} d cos θ{sub μ} data using a theoretical model that, among other nuclear effects, includes RPA correlations and 2p2h (multinucleon) mechanisms. These corrections turn out to be essential for the description of the data. We find that MiniBooNE CCQE-like data are fully compatible with former determinations of the nucleon axial mass M{sub A} ∼ 1.05 GeV. This is in sharp contrast with several previous analysis where anomalously large values of M{sub A} ∼ 1.4 GeV have been suggested. We also show that because of the the multinucleon mechanism effects, the algorithm used to reconstruct the neutrino energy is not adequate when dealing with quasielastic-like events. Finally, we analyze the MiniBooNE unfolded cross section, and show that it exhibits an excess (deficit) of low (high) energy neutrinos, which is an artifact of the unfolding process that ignores 2p2h mechanisms.

  17. Fusion protein His-Hsp65-6IA2P2 prevents type 1 diabetes through nasal immunization in NOD Mice.

    PubMed

    Lu, Shiping; Li, Guoliang; Liu, Kunfeng; Yang, Xue; Cao, Rongyue; Zong, Li; Long, Jun; Jin, Liang; Wu, Jie

    2016-06-01

    Human heat shock protein 60 (Hsp60), is an endogenous β-cells autoantigen, it could postpone the onset of insulitis and sooner type 1 diabetes mellitus. P277 is one of Hsp65 determinants at position 437-469 of amino acids cascaded. Meanwhile, it's already well-known that there were several better anti-diabetic B epitopes, such as insulinoma antigen-2 (IA-2). Currently, fusion protein IA2P2 has constructed in order to enhance its pharmacological efficacy. In addition, added homologous bacterial-derived Hsp65 and His tag were beneficial to protein immunogenicity and purification separately. So, finally we examined a fusion protein His-Hsp65-6IA2P2 could regulate Th2 immune response and reduce natural diabetic incidence in NOD mice. We constructed two express vector pET28a-His-Hsp65-6P277 and pET28a-His-Hsp65-6IA2P2. After purification, we observed that triple intranasal administration of these two fusion protein in 4-week-old NOD mice maintained normal blood glucose and weight, with a lower diabetic or insulitis incidence. Consistent with induced splenic T cells proliferation and tolerance, His-Hsp65-6IA2P2-treated mice performed reduced IFN-γ and increased IL-10 level. In conclusion, we suggested that fusion protein His-Hsp65-6IA2P2 could be reconstructed and purified successively. Furthermore, nasal administration of this fusion protein could rebalance T cells population and prevent T1DM.

  18. Mercury's core evolution

    NASA Astrophysics Data System (ADS)

    Deproost, Marie-Hélène; Rivoldini, Attilio; Van Hoolst, Tim

    2016-10-01

    Remote sensing data of Mercury's surface by MESSENGER indicate that Mercury formed under reducing conditions. As a consequence, silicon is likely the main light element in the core together with a possible small fraction of sulfur. Compared to sulfur, which does almost not partition into solid iron at Mercury's core conditions and strongly decreases the melting temperature, silicon partitions almost equally well between solid and liquid iron and is not very effective at reducing the melting temperature of iron. Silicon as the major light element constituent instead of sulfur therefore implies a significantly higher core liquidus temperature and a decrease in the vigor of compositional convection generated by the release of light elements upon inner core formation.Due to the immiscibility in liquid Fe-Si-S at low pressure (below 15 GPa), the core might also not be homogeneous and consist of an inner S-poor Fe-Si core below a thinner Si-poor Fe-S layer. Here, we study the consequences of a silicon-rich core and the effect of the blanketing Fe-S layer on the thermal evolution of Mercury's core and on the generation of a magnetic field.

  19. Ice Core Investigations

    ERIC Educational Resources Information Center

    Krim, Jessica; Brody, Michael

    2008-01-01

    What can glaciers tell us about volcanoes and atmospheric conditions? How does this information relate to our understanding of climate change? Ice Core Investigations is an original and innovative activity that explores these types of questions. It brings together popular science issues such as research, climate change, ice core drilling, and air…

  20. NFE Core Bibliographies.

    ERIC Educational Resources Information Center

    Michigan State Univ., East Lansing. Inst. for International Studies in Education.

    This collection of core bibliographies, which expands on an initial bibliography published in 1979 of the core resources housed in the Non-Formal Education Information Center at Michigan State University, comprises a basic stock of materials on nonformal education and women in development that have been contributed by development planners,…