3,233 research outputs found

    The Basic Communication Course at U.S. Colleges and Universities: VI

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    This is the sixth in a series of investigations of the basic communication course, begun in 1968 by members of the Undergraduate Speech Instruction Interest Group of the Speech Association of America. This study was replicated in 1974, 1980, 1985, and 1990. Each of these studies gathered and reported information on instructional practices and administrative issues in the basic course at two- and four-year colleges and universities. In this study, the survey instrument from 1990 was revised to reflect contemporary concerns and mailed to the National Communication Association mailing list of 1500 schools. Data were analyzed and presented from 292 responding schools covering institutional demographics and (1) general approach and orientation to the basic course, (2) pedagogy (which subsumes seven sub-categories), (3) enrollment description and dynamics, and (4) administrative concerns. Comparisons to past and studies indicate the basic communication course is thriving and growing, but some of the same problems continue today that beset the course in the past

    On the Convergence of the Born Series in Optical Tomography with Diffuse Light

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    We provide a simple sufficient condition for convergence of Born series in the forward problem of optical diffusion tomography. The condition does not depend on the shape or spatial extent of the inhomogeneity but only on its amplitude.Comment: 23 pages, 7 figures, submitted to Inverse Problem

    Abundances in the Neutral Interstellar Medium of I Zw 18 from FUSE Observations

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    We report on new FUSE far-UV spectroscopy of the most metal-poor blue compact dwarf galaxy I Zw 18. The new data represent an improvement over previous FUSE spectra by a factor of 1.7 in the signal-to-noise. Together with a larger spectral coverage (917-1188 angstroms), this allows us to characterize absorption lines in the interstellar medium with unprecedented accuracy. The kinematics averaged over the large sampled region shows no clear evidence of gas inflows or outflows. The H I absorption is interstellar with a column density of 2.2 (+0.6,-0.5} * 10^21 cm^(-2). A conservative 3 sigma upper limit of 5.25 * 10^(14) cm^(-2) is derived for the column density of diffuse H_2. From a simultaneous fitting of metal absorption lines in the interstellar medium, we infer the following abundances: [Fe/H] = -1.76 +/- 0.12, [O/H] = -2.06 +/- 0.28, [Si/H] = -2.09 +/- 0.12, [Ar/H] = -2.27 +/- 0.13, and [N/H] = -2.88 +/- 0.11. This is in general several times lower than in the H II regions. The only exception is iron, whose abundance is the same. The abundance pattern of the interstellar medium suggests ancient star-formation activity with an age of at least a Gyr that enriched the H I phase. Around 470 SNe Ia are required to produce the iron content. A more recent episode that started 10 to several 100 Myr ago is responsible for the additional enrichment of alpha-elements and nitrogen in the H II regions.Comment: 48 pages including 3 tables (Latex) and 7 figures (postscript). Accepted for publication in the Astrophysical Journa

    1939: Abilene Christian College Bible Lectures - Full Text

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    Delivered in the Auditorium of Abilene Christian College, February, 1939, Abilene, Texas Published October, 1939 PRICE, $1.00 FIRM FOUNDATION PUBLISHING HOUSE Austin, Texas

    Topical Polyethylene Glycol as a Novel Chemopreventive Agent for Oral Cancer via Targeting of Epidermal Growth Factor Response

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    Head and neck squamous cell carcinoma (HNSCC) is a major cause of morbidity and mortality underscoring the need for safe and effective chemopreventive strategies. Targeting epidermal growth factor receptor (EGFR) is attractive in that it is an early critical event in HNSCC pathogenesis. However, current agents lack efficacy or have unacceptable toxicity. Several groups have demonstrated that the over-the-counter medication, polyethylene glycol (PEG) has remarkable chemopreventive efficacy against colon carcinogenesis. Importantly, we reported that this effect is mediated through EGFR internalization/degradation. In the current study, we investigated the chemopreventive efficacy of this agent against HNSCC, using both the well validated animal model 4-NQO (4-nitroquinoline 1-oxide) rat model and cell culture with the human HNSCC cell line SCC-25. We demonstrated that daily topical application of 10% PEG-8000 in the oral cavity (tongue and cavity wall) post 4NQO initiation resulted in a significant reduction in tumor burden (both, tumor size and tumors/tumor bearing rat) without any evidence of toxicity. Immunohistochemical studies depicted decreased proliferation (number of Ki67-positive cells) and reduced expression of EGFR and its downstream effectors cyclin D1 in the tongue mucosa of 4NQO-rats treated with PEG. We showed that EGFR was also markedly downregulated in SCC-25 cells by PEG-8000 with a concomitant induction of G1-S phase cell-cycle arrest, which was potentially mediated through upregulated p21cip1/waf1. In conclusion, we demonstrate, for the first time, that PEG has promising efficacy and safety as a chemopreventive efficacy against oral carcinogenesis

    Search for the Higgs boson in events with missing transverse energy and b quark jets produced in proton-antiproton collisions at s**(1/2)=1.96 TeV

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    We search for the standard model Higgs boson produced in association with an electroweak vector boson in events with no identified charged leptons, large imbalance in transverse momentum, and two jets where at least one contains a secondary vertex consistent with the decay of b hadrons. We use ~1 fb-1 integrated luminosity of proton-antiproton collisions at s**(1/2)=1.96 TeV recorded by the CDF II experiment at the Tevatron. We find 268 (16) single (double) b-tagged candidate events, where 248 +/- 43 (14.4 +/- 2.7) are expected from standard model background processes. We place 95% confidence level upper limits on the Higgs boson production cross section for several Higgs boson masses ranging from 110 GeV/c2 to 140 GeV/c2. For a mass of 115 GeV/c2 the observed (expected) limit is 20.4 (14.2) times the standard model prediction.Comment: 8 pages, 2 figures, submitted to Phys. Rev. Let

    Isolation of Flow and Nonflow Correlations by Two- and Four-Particle Cumulant Measurements of Azimuthal Harmonics in sNN=\sqrt{s_{_{\rm NN}}} = 200 GeV Au+Au Collisions

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    A data-driven method was applied to measurements of Au+Au collisions at sNN=\sqrt{s_{_{\rm NN}}} = 200 GeV made with the STAR detector at RHIC to isolate pseudorapidity distance Δη\Delta\eta-dependent and Δη\Delta\eta-independent correlations by using two- and four-particle azimuthal cumulant measurements. We identified a component of the correlation that is Δη\Delta\eta-independent, which is likely dominated by anisotropic flow and flow fluctuations. It was also found to be independent of η\eta within the measured range of pseudorapidity η<1|\eta|<1. The relative flow fluctuation was found to be 34%±2%(stat.)±3%(sys.)34\% \pm 2\% (stat.) \pm 3\% (sys.) for particles of transverse momentum pTp_{T} less than 22 GeV/cc. The Δη\Delta\eta-dependent part may be attributed to nonflow correlations, and is found to be 5%±2%(sys.)5\% \pm 2\% (sys.) relative to the flow of the measured second harmonic cumulant at Δη>0.7|\Delta\eta| > 0.7
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