370 research outputs found

    The Robertson v. Princeton Case: Too Important to Be Left to the Lawyers

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    Offers comments from eleven contributors on the Robertson family's donor rights suit against the Woodrow Wilson School of Public and International Affairs for violation of donor intent. Explores its effects on and implications for the nonprofit sector

    Motion microscopy for visualizing and quantifying small motions

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    Although the human visual system is remarkable at perceiving and interpreting motions, it has limited sensitivity, and we cannot see motions that are smaller than some threshold. Although difficult to visualize, tiny motions below this threshold are important and can reveal physical mechanisms, or be precursors to large motions in the case of mechanical failure. Here, we present a “motion microscope,” a computational tool that quantifies tiny motions in videos and then visualizes them by producing a new video in which the motions are made large enough to see. Three scientific visualizations are shown, spanning macroscopic to nanoscopic length scales. They are the resonant vibrations of a bridge demonstrating simultaneous spatial and temporal modal analysis, micrometer vibrations of a metamaterial demonstrating wave propagation through an elastic matrix with embedded resonating units, and nanometer motions of an extracellular tissue found in the inner ear demonstrating a mechanism of frequency separation in hearing. In these instances, the motion microscope uncovers hidden dynamics over a variety of length scales, leading to the discovery of previously unknown phenomena

    A search for W bb and W Higgs production in ppbar collisions at sqrt(s)=1.96 TeV

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    We present a search for W b \bar{b} production in p \bar{p} collisions at sqrt{s}=1.96 TeV in events containing one electron, an imbalance in transverse momentum, and two b-tagged jets. Using 174 pb-1 of integrated luminosity accumulated by the D0 experiment at the Fermilab Tevatron collider, and the standard-model description of such events, we set a 95% C.L. upper limit on W b \bar{b}productionof6.6pbforbquarkswithtransversemomentapTb>20GeVandbbˉseparationinpseudorapidityazimuthspaceDeltaRbb>0.75.Restrictingthesearchtooptimizedbbˉmassintervalsprovidesupperlimitson production of 6.6 pb for b quarks with transverse momenta p_T^b > 20 GeV and b \bar{b} separation in pseudorapidity-azimuth space Delta R_bb > 0.75. Restricting the search to optimized b \bar{b} mass intervals provides upper limits on WHproductionof9.0 production of 9.0-12.2pb,forHiggsbosonmassesof10512.2 pb, for Higgs-boson masses of 105-$135 GeV.Comment: 7 pages, 4 figures, 1 table, submitted to Physical Review Letter

    Chlorpromazine versus placebo for schizophrenia

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    Measurement of the Ratio of B+ and B0 Meson Lifetimes

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    The ratio of B+ and B0 meson lifetimes was measured using data collected in 2002-2004 by the D0 experiment in Run II of the Fermilab Tevatron Collider. These mesons were reconstructed in B -> mu+ nu D*- X decays, which are dominated by B0, and B ->mu+ nu D0bar X decays, which are dominated by B+. The ratio of lifetimes is measured to be t+/t0 = 1.080 +- 0.016(stat) +- 0.014(syst).Comment: 7 pages, 2 figures, LaTeX, to be submitted to Physical Review Letter

    A Search for the Flavor-Changing Neutral Current Decay B0_s -> mu^+mu^- in pp(bar) Collisions at \sqrt{s} = 1.96 TeV with the D0 Detector

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    We present the results of a search for the flavor-changing neutral current decay B0_s -> mu+ mu- using a data set with integrated luminosity of 240 pb^{-1} of pp(bar) collisions at sqrt{s}=1.96 TeV collected with the D0 detector in Run II of the Fermilab Tevatron collider. We find the upper limit on the branching fraction to be Br(B0_s -> mu+ mu-) \leq 5.0 x 10^{-7} at the 95% C.L. assuming no contributions from the decay B0_d -> mu+ mu- in the signal region. This limit is the most stringent upper bound on the branching fraction B0_s -> mu+ mu- to date.Comment: 7 pages, 3 figures, LaTeX, to be submitted to Physical Review Letters, minor changes to text, reference adde

    Search for the standard model Higgs boson decaying to a bbˉb\bar{b} pair in events with no charged leptons and large missing transverse energy using the full CDF data set

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    We report on a search for the standard model Higgs boson produced in association with a vector boson in the full data set of proton-antiproton collisions at s=1.96\sqrt{s} = 1.96 TeV recorded by the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45 fb1^{-1}. We consider events having no identified charged lepton, a transverse energy imbalance, and two or three jets, of which at least one is consistent with originating from the decay of a bb quark. We place 95% credibility level upper limits on the production cross section times standard model branching fraction for several mass hypotheses between 90 and 150GeV/c2150 \mathrm{GeV}/c^2. For a Higgs boson mass of 125GeV/c2125 \mathrm{GeV}/c^2, the observed (expected) limit is 6.7 (3.6) times the standard model prediction.Comment: Accepted by Phys. Rev. Let

    Do organizational climate and competitive strategy moderate the relationship between human resource management and productivity?

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    This study examined whether the effectiveness of human resource management (HRM)practices is contingent on organizational climate and competitive strategy The concepts of internol and external fit suggest that the positive relationship between HRM and subsequent productivity will be stronger for firms with a positive organizational climate and for firms using differentiation strategies. Resource allocation theories of motivation, on the other hand, predict that the relationship between HRM and productivity will be stronger for firms with a poor climate because employees working in these firms should have the greatest amount of spare capacity. The results supported the resource allocation argument
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