2,744 research outputs found

    Law and Quantitative Multivariate Analysis: An Encounter

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    This Article chronicles one attempt to blend the sophisticated science of statistics with the mysterious art of the law in an antitrust case. Once again, we hope to provide lawyers with an understanding of a tool which can be used in resolving complex factual questions wherever they arise, not merely in an antitrust context. Although the lawyer will not emerge from this encounter as an accomplished statistician or economist, he may be able to talk to his fellow social scientists and to achieve a more fruitful application of social science techniques to the law

    Free Radicals in Superfluid Liquid Helium Nanodroplets: A Pyrolysis Source for the Production of Propargyl Radical

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    An effusive pyrolysis source is described for generating a continuous beam of radicals under conditions appropriate for the helium droplet pick-up method. Rotationally resolved spectra are reported for the ν1\nu_1 vibrational mode of the propargyl radical in helium droplets at 3322.15 cm1^{-1}. Stark spectra are also recorded that allow for the first experimental determination of the permanent electric dipole moment of propargyl, namely -0.150 D and -0.148 D for ground and excited state, respectively, in good agreement with previously reported ab initio results of -0.14 D [1]. The infrared spectrum of the ν1\nu_1 mode of propargyl-bromide is also reported. The future application of these methods for the production of novel radical clusters is discussed

    Challenge pools of hepatitis C virus genotypes 1-6 prototype strains: replication fitness and pathogenicity in chimpanzees and human liver-chimeric mouse models

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    Chimpanzees represent the only animal model for studies of the natural history of hepatitis C virus (HCV). To generate virus stocks of important HCV variants, we infected chimpanzees with HCV strains of genotypes 1-6 and determined the infectivity titer of acute-phase plasma pools in additional animals. The courses of first- and second-passage infections were similar, with early appearance of viremia, HCV RNA titers of >10(4.7) IU/mL, and development of acute hepatitis; the chronicity rate was 56%. The challenge pools had titers of 10(3)-10(5) chimpanzee infectious doses/mL. Human liver-chimeric mice developed high-titer infections after inoculation with the challenge viruses of genotypes 1-6. Inoculation studies with different doses of the genotype 1b pool suggested that a relatively high virus dose is required to consistently infect chimeric mice. The challenge pools represent a unique resource for studies of HCV molecular virology and for studies of pathogenesis, protective immunity, and vaccine efficacy in vivo

    Evidence for a Self-Bound Liquid State and the Commensurate-Incommensurate Coexistence in 2D 3^3He on Graphite

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    We made heat-capacity measurements of two dimensional (2D) 3^3He adsorbed on graphite preplated with monolayer 4^4He in a wide temperature range (0.1 T\leq T \leq 80 mK) at densities higher than that for the 4/7 phase (= 6.8 nm2^{-2}). In the density range of 6.8 ρ\leq \rho \leq 8.1 nm2^{-2}, the 4/7 phase is stable against additional 3^3He atoms up to 20% and they are promoted into the third layer. We found evidence that such promoted atoms form a self-bound 2D Fermi liquid with an approximate density of 1 nm2^{-2} from the measured density dependence of the γ\gamma-coefficient of heat capacity. We also show evidence for the first-order transition between the commensurate 4/7 phase and the ferromagnetic incommensurate phase in the second layer in the density range of 8.1 ρ\leq \rho \leq 9.5 nm2^{-2}.Comment: 6 pages, 4 figure

    Changes in the Adult GluN2B Associated Proteome following Adolescent Intermittent Ethanol Exposure

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    Adolescent alcohol use is the strongest predictor for alcohol use disorders. In rodents, adolescents have distinct responses to acute ethanol, and prolonged alcohol exposure during adolescence can maintain these phenotypes into adulthood. One brain region that is particularly sensitive to the effects of both acute and chronic ethanol exposure is the hippocampus. Adolescent intermittent ethanol exposure (AIE) produces long lasting changes in hippocampal synaptic plasticity and dendritic morphology, as well as in the susceptibility to acute ethanol-induced spatial memory impairment. Given the pattern of changes in hippocampal structure and function, one potential target for these effects is the ethanol sensitive GluN2B subunit of the NMDA receptor, which is known to be involved in synaptic plasticity and dendritic morphology. Thus we sought to determine if there were persistent changes in hippocampal GluN2B signaling cascades following AIE. We employed a previously validated GluN2B-targeted proteomic strategy that was used to identify novel signaling mechanisms altered by chronic ethanol exposure in the adult hippocampus. We collected adult hippocampal tissue (P70) from rats that had been given 2 weeks of AIE from P30-45. Tissue extracts were fractionated into synaptic and non-synaptic pools, immuno-precipitated for GluN2B, and then analyzed using proteomic methods. We detected a large number of proteins associated with GluN2B. AIE produced significant changes in the association of many proteins with GluN2B in both synaptic and non-synaptic fractions. Intriguingly the number of proteins changed in the non-synaptic fraction was double that found in the synaptic fraction. Some of these proteins include those involved in glutamate signaling cytoskeleton rearrangement, calcium signaling, and plasticity. Disruptions in these pathways may contribute to the persistent cellular and behavioral changes found in the adult hippocampus following AIE. Further, the robust change in non-synaptic proteins suggests that AIE may prime this signaling pathway for future ethanol exposures in adulthood

    Observations of the Crab Nebula and its pulsar in the far-ultraviolet and in the optical

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    We present HST/STIS far-UV observations of the Crab nebula and its pulsar. Broad, blueshifted absorption arising in the nebula is seen in C IV 1550, reaching about 2500 km/s. This can be interpreted as evidence for a fast outer shell, and we adopt a spherically symmetric model to constrain the properties of this. We find that the density appears to decrease outward in the shell. A lower limit to the mass is 0.3 solar masses with an accompanying kinetic energy of 1.5EE{49} ergs. A massive 10^{51} erg shell cannot be excluded, but is less likely if the density profile is much steeper than R^{-4} and the velocity is <6000 km/s. The observations cover the region 1140-1720 A. With the time-tag mode of the spectrograph we obtain the pulse profile. It is similar to that in the near-UV, although the primary peak is marginally narrower. Together with the near-UV data, and new optical data from NOT, our spectrum of the pulsar covers the entire region from 1140-9250 A. Dereddening the spectrum gives a flat spectrum for E(B-V)=0.52, R=3.1. This dereddened spectrum of the Crab pulsar can be fitted by a power law with spectral index alpha_{\nu} = 0.11 +/- 0.04. The main uncertainty is the amount and characteristics of the interstel- lar reddening, and we have investigated the dependence of \alpha_{\nu} on E(B-V) and R. In the extended emission covered by our 25" x 0.5" slit in the far-UV, we detect C IV 1550 and He II 1640 emission lines from the Crab nebula. Several interstellar absorption lines are detected toward the pulsar. The Ly alpha absorption indicates a column density of 3.0+/-0.5\EE{21} cm^{-2} of neutral hydrogen, which agrees well with our estimate of E(B-V)=0.52 mag. Other lines show no evidence of severe depletion of metals in atomic gas.Comment: 18 pages emulateapj style, including 10 figures. ApJ, accepte

    Ursinus College Alumni Journal, November 1955

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    Program for new dormitories underway • Business, the alumnus, and the cost of higher education • Campbell Soup Company establishes fund • James Hirst named to honor society • 18th annual performance announced of the Messiah • Attendance increases in the Ursinus College Evening School • Some notes from the Dean\u27s office • Registrar\u27s report on fall enrollment • Ursinus forum 1955-1956 • Max C. Putney \u2718 author of The Man of Galilee • South Jersey alumni honor Dr. McClure • Binder named Dean at Thiel College • Berks County alumni hold clam bake • Dr. Sherman A. Eger \u2725 describes new operation for high blood pressure • James J. Herron \u2732 elected vice-president of Dun & Bradstreet, Inc. • Alumni eligible for Fulbright scholarships • Ursinus Women\u27s Club • Committee to review alumni constitution • A Fulbrighter in Japan • 1955 Loyalty Fund report • Sick transit - or - She perks no more • Curtain Club presents The Madwoman of Chaillot • Class of \u2756 elects permanent alumni officers • Mrs. Snyder new preceptress at Duryea Hall • G. E. reports on its corporate alumnus program • Regional alumni groups plan student trip • Warren K. Hess \u2731 addresses state school directors • 51\u27ers quartet meet after four years • History art collection • Sports review: Soccer report; Facts about the coaching staff; Alumni varsity basketball game • News about ourselves • Weddings • Births • Necrologyhttps://digitalcommons.ursinus.edu/alumnijournal/1054/thumbnail.jp

    A Comparison of Lifting-Line and CFD Methods with Flight Test Data from a Research Puma Helicopter

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    Four lifting-line methods were compared with flight test data from a research Puma helicopter and the accuracy assessed over a wide range of flight speeds. Hybrid Computational Fluid Dynamics (CFD) methods were also examined for two high-speed conditions. A parallel analytical effort was performed with the lifting-line methods to assess the effects of modeling assumptions and this provided insight into the adequacy of these methods for load predictions
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