5,251 research outputs found

    Speech Communication at Iowa State University: A History of Broken Promises and Shifting Leadership

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    This article attempts to offer a constructive analysis of pressures applied to the Department of Speech Communication at Iowa State University and the circumstances which have resulted in the changes that have occurred, as of September 1995. The department has been in a state of instability and insecurity for more than 20 years. There has long been a sense of foreboding over the department, probably since it began to expand its curriculum beyond simply offering basic public speaking. In the fall of 1986, the department was a multi-focus department, composed of four separate interest areas, including speech communication, theater, telecommunicative arts and communication disorders. The one constant, whether the focus is on one of the sub-group of department executive officers or on the college as a whole, was the fact that speech communication was not prioritized

    The clustering and bias of radio-selected AGN and star-forming galaxies in the COSMOS field

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    Dark matter haloes in which galaxies reside are likely to have a significant impact on their evolution. We investigate the link between dark matter haloes and their constituent galaxies by measuring the angular two-point correlation function of radio sources, using recently released 3 GHz imaging over $\sim 2 \ \mathrm{deg}^2oftheCOSMOSfield.WesplittheradiosourcepopulationintoStarFormingGalaxies(SFGs)andActiveGalacticNuclei(AGN),andfurtherseparatetheAGNintoradiativelyefficientandinefficientaccreters.Restrictingouranalysisto of the COSMOS field. We split the radio source population into Star Forming Galaxies (SFGs) and Active Galactic Nuclei (AGN), and further separate the AGN into radiatively efficient and inefficient accreters. Restricting our analysis to z<1,wefindSFGshaveabias,, we find SFGs have a bias, b = 1.5 ^{+0.1}_{-0.2},atamedianredshiftof, at a median redshift of z=0.62.Ontheotherhand,AGNaresignificantlymorestronglyclusteredwith. On the other hand, AGN are significantly more strongly clustered with b = 2.1\pm 0.2atamedianredshiftof0.7.ThissupportstheideathatAGNarehostedbymoremassivehaloesthanSFGs.WealsofindlowaccretionrateAGNaremoreclustered( at a median redshift of 0.7. This supports the idea that AGN are hosted by more massive haloes than SFGs. We also find low-accretion rate AGN are more clustered (b = 2.9 \pm 0.3)thanhighaccretionrateAGN() than high-accretion rate AGN (b = 1.8^{+0.4}_{-0.5})atthesameredshift() at the same redshift (z \sim 0.7),suggestingthatlowaccretionrateAGNresideinhighermasshaloes.ThissupportspreviousevidencethattherelativelyhotgasthatinhabitsthemostmassivehaloesisunabletobeeasilyaccretedbythecentralAGN,causingthemtobeinefficient.WealsofindevidencethatlowaccretionrateAGNappeartoresideinhalomassesof), suggesting that low-accretion rate AGN reside in higher mass haloes. This supports previous evidence that the relatively hot gas that inhabits the most massive haloes is unable to be easily accreted by the central AGN, causing them to be inefficient. We also find evidence that low-accretion rate AGN appear to reside in halo masses of M_{h} \sim 3-4 \times 10^{13}h^{-1}MM_{\odot}atallredshifts.Ontheotherhand,theefficientaccretersresideinhaloesof at all redshifts. On the other hand, the efficient accreters reside in haloes of M_{h} \sim 1-2 \times 10^{13}h^{-1}MM_{\odot}atlowredshiftbutcanresideinrelativelylowermasshaloesathigherredshifts.Thiscouldbeduetotheincreasedprevalenceofcoldgasinlowermasshaloesat at low redshift but can reside in relatively lower mass haloes at higher redshifts. This could be due to the increased prevalence of cold gas in lower mass haloes at z \ge 1comparedto compared to z<1$.Comment: 20 pages, 10 figures, 1 table, accepted by MNRA

    4He experiments can serve as a database for determining the three-nucleon force

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    We report on microscopic calculations for the 4He compound system in the framework of the resonating group model employing realistic nucleon-nucleon and three nucleon forces. The resulting scattering phase shifts are compared to those of a comprehensive R-matrix analysis of all data in this system, which are available in numerical form. The agreement between calculation and analysis is in most cases very good. Adding three-nucleon forces yields in many cases large effects. For a few cases the new agreement is striking. We relate some differencies between calculation and analysis to specific data and discuss neccessary experiments to clarify the situation. From the results we conclude that the data of the 4He system might be well suited to determine the structure of the three-nucleon force.Comment: title changed,note added, format of figures changed, appearance of figures in black-and-white changed, Phys. Rev. C accepte

    Search for the Radiative Capture d+d->^4He+\gamma Reaction from the dd\mu Muonic Molecule State

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    A search for the muon catalyzed fusion reaction dd --> ^4He +\gamma in the dd\mu muonic molecule was performed using the experimental \mu CF installation TRITON and NaI(Tl) detectors for \gamma-quanta. The high pressure target filled with deuterium at temperatures from 85 K to 800 K was exposed to the negative muon beam of the JINR phasotron to detect \gamma-quanta with energy 23.8 MeV. The first experimental estimation for the yield of the radiative deuteron capture from the dd\mu state J=1 was obtained at the level n_{\gamma}\leq 2\times 10^{-5} per one fusion.Comment: 9 pages, 3 Postscript figures, submitted to Phys. At. Nuc

    Collective modes in uniaxial incommensurate-commensurate systems with the real order parameter

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    The basic Landau model for uniaxial systems of the II class is nonintegrable, and allows for various stable and metastable periodic configurations, beside that representing the uniform (or dimerized) ordering. In the present paper we complete the analysis of this model by performing the second order variational procedure, and formulating the combined Floquet-Bloch approach to the ensuing nonstandard linear eigenvalue problem. This approach enables an analytic derivation of some general conclusions on the stability of particular states, and on the nature of accompanied collective excitations. Furthermore, we calculate numerically the spectra of collective modes for all states participating in the phase diagram, and analyze critical properties of Goldstone modes at all second order and first order transitions between disordered, uniform and periodic states. In particular it is shown that the Goldstone mode softens as the underlying soliton lattice becomes more and more dilute.Comment: 19 pages, 16 figures, REVTeX, to be published in Journal of Physics A: Mathematical and Genera

    Incidence of diabetic retinopathy in people with type 2 diabetes mellitus attending the Diabetic Retinopathy Screening Service for Wales: retrospective analysis

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    Objectives To determine the incidence of any and referable diabetic retinopathy in people with type 2 diabetes mellitus attending an annual screening service for retinopathy and whose first screening episode indicated no evidence of retinopathy

    Kinetics of photoinduced ordering in azo-dye films: two-state and diffusion models

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    We study the kinetics of photoinduced ordering in the azo-dye SD1 photoaligning layers and present the results of modeling performed using two different phenomenological approaches. A phenomenological two state model is deduced from the master equation for an ensemble of two-level molecular systems. Using an alternative approach, we formulate the two-dimensional (2D) diffusion model as the free energy Fokker-Planck equation simplified for the limiting regime of purely in-plane reorientation. The models are employed to interpret the irradiation time dependence of the absorption order parameters extracted from the available experimental data by using the exact solution to the light transmission problem for a biaxially anisotropic absorbing layer. The transient photoinduced structures are found to be biaxially anisotropic whereas the photosteady and the initial states are uniaxial.Comment: revtex4, 34 pages, 9 figure

    The ‘Galilean Style in Science’ and the Inconsistency of Linguistic Theorising

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    Chomsky’s principle of epistemological tolerance says that in theoretical linguistics contradictions between the data and the hypotheses may be temporarily tolerated in order to protect the explanatory power of the theory. The paper raises the following problem: What kinds of contradictions may be tolerated between the data and the hypotheses in theoretical linguistics? First a model of paraconsistent logic is introduced which differentiates between week and strong contradiction. As a second step, a case study is carried out which exemplifies that the principle of epistemological tolerance may be interpreted as the tolerance of week contradiction. The third step of the argumentation focuses on another case study which exemplifies that the principle of epistemological tolerance must not be interpreted as the tolerance of strong contradiction. The reason for the latter insight is the unreliability and the uncertainty of introspective data. From this finding the author draws the conclusion that it is the integration of different data types that may lead to the improvement of current theoretical linguistics and that the integration of different data types requires a novel methodology which, for the time being, is not available

    The ‘Galilean Style in Science’ and the Inconsistency of Linguistic Theorising

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    Chomsky’s principle of epistemological tolerance says that in theoretical linguistics contradictions between the data and the hypotheses may be temporarily tolerated in order to protect the explanatory power of the theory. The paper raises the following problem: What kinds of contradictions may be tolerated between the data and the hypotheses in theoretical linguistics? First a model of paraconsistent logic is introduced which differentiates between week and strong contradiction. As a second step, a case study is carried out which exemplifies that the principle of epistemological tolerance may be interpreted as the tolerance of week contradiction. The third step of the argumentation focuses on another case study which exemplifies that the principle of epistemological tolerance must not be interpreted as the tolerance of strong contradiction. The reason for the latter insight is the unreliability and the uncertainty of introspective data. From this finding the author draws the conclusion that it is the integration of different data types that may lead to the improvement of current theoretical linguistics and that the integration of different data types requires a novel methodology which, for the time being, is not available

    Synthesis of the elements in stars: forty years of progress

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    Forty years ago Burbidge, Burbidge, Fowler, and Hoyle combined what we would now call fragmentary evidence from nuclear physics, stellar evolution and the abundances of elements and isotopes in the solar system as well as a few stars into a synthesis of remarkable ingenuity. Their review provided a foundation for forty years of research in all of the aspects of low energy nuclear experiments and theory, stellar modeling over a wide range of mass and composition, and abundance studies of many hundreds of stars, many of which have shown distinct evidence of the processes suggested by B2FH. In this review we summarize progress in each of these fields with emphasis on the most recent developments
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