4,470 research outputs found

    Finding the skills for tomorrow: Information literacy and museum information professionals

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    The VST telescope control software in the ESO VLT environment

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    The VST (VLT Survey Telescope) is a 2.6 m Alt-Az telescope to be installed at Mount Paranal in Chile, in the European Southern Observatory (ESO) site. The VST is a wide-field imaging facility planned to supply databases for the ESO Very Large Telescope (VLT) science and carry out stand-alone observations in the UV to I spectral range. This paper will focus mainly on control software aspects, describing the VST software architecture in the context of the whole ESO VLT control concept. The general architecture and the main components of the control software will be described.Comment: 3 pages, 2 figures, ICALEPCS 2001 Conference, PSN#THAP05

    Absolute FKBP binding affinities obtained via non-equilibrium unbinding simulations

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    We compute absolute binding affinities for two ligands bound to the FKBP protein using non-equilibrium unbinding simulations. The methodology is straight-forward, requiring little or no modification to many modern molecular simulation packages. The approach makes use of a physical pathway, eliminating the need for complicated alchemical decoupling schemes. Results of this study are promising. For the ligands studied here the binding affinities are typically estimated within less than 4.0 kJ/mol of the target values; and the target values are within less than 1.0 kJ/mol of experiment. These results suggest that non-equilibrium simulation could provide a simple and robust means to estimate protein-ligand binding affinities.Comment: 9 pages, 3 figures (no necessary color). Changes made to methodology and results between revision

    Ground State of the Easy-Axis Rare-Earth Kagom\'e Langasite Pr3_3Ga5_5SiO14_{14}

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    We report muon spin relaxation (μ\muSR) and 69,71^{69,71}Ga nuclear quadrupolar resonance (NQR) local-probe investigations of the kagom\'e compound Pr3_3Ga5_5SiO14_{14}. Small quasi-static random internal fields develop below 40 K and persist down to our base temperature of 21 mK. They originate from hyperfine-enhanced 141^{141}Pr nuclear magnetism which requires a non-magnetic Pr3+^{3+} crystal-field (CF) ground state. Besides, we observe a broad maximum of the relaxation rate at 10\simeq 10 K which we attribute to the population of the first excited magnetic CF level. Our results yield a Van-Vleck paramagnet picture, at variance with the formerly proposed spin-liquid ground state.Comment: minor change

    The X-ray nebula of the filled center supernova remnant 3C58 and its interaction with the environment

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    An \xmm observation of the plerionic supernova remnant 3C58 has allowed us to study the X-ray nebula with unprecedented detail. A spatially resolved spectral analysis with a resolution of 8\arcsec has yielded a precise determination of the relation between the spectral index and the distance from the center. We do not see any evidence for bright thermal emission from the central core. In contrast with previous ASCA and {\em Einstein} results, we derive an upper limit to the black-body 0.5-10 keV luminosity and emitting area of 1.8×10321.8\times 10^{32} \ergsec and 1.3×10101.3\times 10^{10} cm2^2, respectively, ruling out emission from the hot surface of the putative neutron star and also excluding the "outer-gap" model for hot polar caps. We have performed for the first time a spectral analysis of the outer regions of the X-ray nebula, where most of the emission is still non-thermal, but where the addition of a soft (kT=0.2-0.3 keV) optically thin plasma component is required to fit the spectrum at E<1E<1 keV. This component provides 6% of the whole remnant observed flux in the 0.5-10.0 keV band. We show that a Sedov interpretation is incompatible with the SN1181-3C58 association, unless there is a strong deviation from electron-ion energy equipartition, and that an origin of this thermal emission in terms of the expansion of the nebula into the ejecta core nicely fits all the radio and X-ray observations.Comment: 10 pages, 7 figures, accepted for publication in A&

    Ni abundance in the core of the Perseus Cluster: an answer to the significance of resonant scattering

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    Using an XMM-Newton observation of the Perseus cluster we show that the excess in the flux of the 7-8 keV line complex previously detected by ASCA and BeppoSAX is due to an overabundance of Nickel rather than to an anomalously high Fe Heβ\beta/Fe Heα\alpha ratio. This observational fact leads to the main result that resonant scattering, which was assumed to be responsible for the supposed anomalous Fe Heβ\beta/Fe Heα\alpha ratio, is no longer required. The absence of resonant scattering points towards the presence of significant gas motions (either turbulent or laminar) in the core of the Perseus cluster.Comment: 29 pages, 10 bw figures, accepted for publication in the Astrophysical Journa

    Structural Identity Theory and the Dynamics of Cross-Cultural Work Groups

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    The creation of a global village, transnational corporations, internet and similar influences remind us constantly that a science of organizations and management is incomplete without the integration of concepts of culture and self-awareness. It is no longer appropriate to discuss organizational activities and employee actions without incorporating a more complete view of where such activities take place. Not only must we include an immediate social context, but we must deal with the international and cultural aspects of the social world as well. More than ever, understanding of employee action requires knowledge of how action is related to the environment in which it is embedded. Using this general focus, we examine a number of significant issues concerning cultural influences on work groups and teams. Our emphasis is the extension and elaboration of other reviews concerning work teams evaluated cross-culturally. The interested reader is referred to a number of articles including Mann (1980), Triandis (1994), Tannenbaum (1980), Earley and Gibson (in press), Granrose and Oskamp (1997), and Ravlin et al. (in press) among others. Our review contains three sections, the first of which is a discussion of traditional approaches to studying teams including the emphasis used in this chapter. In the second section, we use our framework to review literature concerning cultural influences in relation to work teams. Finally, we make a number of recommendations for future research and indicate how our contextual-structural approach extends existing lines of work

    Single domain magnetic helicity and triangular chirality in structurally enantiopure Ba3NbFe3Si2O14

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    A novel doubly chiral magnetic order is found out in the structurally chiral langasite compound Ba3_3NbFe3_3Si2_2O14_{14}. The magnetic moments are distributed over planar frustrated triangular lattices of triangle units. On each of these they form the same triangular configuration. This ferro-chiral arrangement is helically modulated from plane to plane. Unpolarized neutron scattering on a single crystal associated with spherical neutron polarimetry proved that a single triangular chirality together with a single helicity is stabilized in an enantiopure crystal. A mean field analysis allows discerning the relevance on this selection of a twist in the plane to plane supersuperexchange paths
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