2,707 research outputs found

    New QCD Sum Rules for Nucleons in Nuclear Matter

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    Two new QCD sum rules for nucleons in nuclear matter are obtained from a mixed correlator of spin-1/2 and spin-3/2 interpolating fields. These new sum rules, which are insensitive to the poorly known four-quark condensates, provide additional information on the nucleon scalar self-energy. These new sum rules are analyzed along with previous spin-1/2 interpolator-based sum rules which are also insensitive to the poorly known four-quark condensates. The analysis indicates consistency with the expectations of relativistic nuclear phenomenology at nuclear matter saturation density. However, a weaker density dependence near saturation is suggested. Using previous estimates of in-medium condensate uncertainties, we find M∗=0.64−0.09+0.13M^* = 0.64^{+0.13}_{-0.09} GeV and Σv=0.29−0.10+0.06\Sigma_v = 0.29^{+0.06}_{-0.10} GeV at nuclear matter saturation density.Comment: 10 page RevTeX Manuscript with embedded figures. Revised manuscript accepted for publication. This and related papers may also be obtained from http://www.phys.washington.edu/~derek/Publications.htm

    Analysis of the genome sequence of an alpaca coronavirus

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    AbstractCoronaviral infection of New World camelids was first identified in 1998 in llamas and alpacas with severe diarrhea. In order to understand this infection, one of the coronavirus isolates was sequenced and analyzed. It has a genome of 31,076 nt including the poly A tail at the 3â€Č end. This virus designated as ACoV-00-1381 (ACoV) encodes all 10 open reading frames (ORFs) characteristic of Group 2 bovine coronavirus (BCoV). Phylogenetic analysis showed that the ACoV genome is clustered closely (>99.5% identity) with two BCoV strains, ENT and LUN, and was also closely related to other BCoV strains (Mebus, Quebec, DB2), a human corona virus (strain 043) (>96%), and porcine hemagglutinating encephalomyelitis virus (>93% identity). A total of 145 point mutations and one nucleotide deletion were found relative to the BCoV ENT. Most of the ORFs were highly conserved; however, the predicted spike protein (S) has 9 and 12 amino acid differences from BCoV LUN and ENT, respectively, and shows a higher relative number of changes than the other proteins. Phylogenetic analysis suggests that ACoV shares the same ancestor as BCoV ENT and LUN

    The effects of an experimental programme to support students’ autonomy on the overt behaviours of physical education teachers

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    Although the benefits of autonomy supportive behaviours are now well established in the literature, very few studies have attempted to train teachers to offer a greater autonomy support to their students. In fact, none of these studies has been carried out in physical education (PE). The purpose of this study is to test the effects of an autonomy-supportive training on overt behaviours of teaching among PE teachers. The experimental group included two PE teachers who were first educated on the benefits of an autonomy supportive style and then followed an individualised guidance programme during the 8 lessons of a teaching cycle. Their behaviours were observed and rated along 3 categories (i.e., autonomy supportive, neutral and controlling) and were subsequently compared to those of three teachers who formed the control condition. The results showed that teachers in the experimental group used more autonomy supportive and neutral behaviours than those in the control group, but no difference emerged in relation to controlling behaviours. We discuss the implications for schools of our findings

    Effect of Iodine Doping on Bi2_{2}Sr2_{2}Ca1_{1}Cu2_{2}Ox_{x}: Charge Transfer or Interlayer Coupling?

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    A comparative study has been made of iodine-intercalated Bi2_{2}Sr2_{2}Ca1_{1}Cu2_{2}Ox_{x} single crystal and 1 atm O2_{2} annealed Bi2_{2}Sr2_{2}Ca1_{1}Cu1_{1}Ox_{x} single crystal using AC susceptibility measurement, X-ray photoemission (XPS) and angle-resolved ultraviolet photoemission spectroscopy (ARUPS). AC susceptibility measurement indicates that O2_{2}-doped samples studied have Tc_{c} of 84 o^{o}K, whereas Tc_{c} of Iodine-doped samples studied are 80 o^{o}K. XPS Cu 2p core level data establish that the hole concentration in the CuO2_{2} planes are essentially the same for these two kinds of samples. ARUPS measurements show that electronic structure of the normal states near the Fermi level has been strongly affected by iodine intercalation. We conclude that the dominant effect of iodine doping is to alter the interlayer coupling.Comment: LBL 9 pages, APS_Revtex. 5 Figures, available upon request. UW-Madison preprin

    Numerical approximation of the Euler-Poisson-Boltzmann model in the quasineutral limit

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    This paper analyzes various schemes for the Euler-Poisson-Boltzmann (EPB) model of plasma physics. This model consists of the pressureless gas dynamics equations coupled with the Poisson equation and where the Boltzmann relation relates the potential to the electron density. If the quasi-neutral assumption is made, the Poisson equation is replaced by the constraint of zero local charge and the model reduces to the Isothermal Compressible Euler (ICE) model. We compare a numerical strategy based on the EPB model to a strategy using a reformulation (called REPB formulation). The REPB scheme captures the quasi-neutral limit more accurately

    Relating imperatives to action

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    The aim of this chapter is to provide an analysis of the use of logically complex imperatives, in particular, imperatives of the form Do A1 or A2 and Do A, if B. We argue for an analysis of imperatives in terms of classical logic which takes into account the influence of background information on imperatives. We show that by doing so one can avoid some counter-intuitive results which have been associated with analyses of imperatives in terms of classical logic. In particular, I address Hamblin's observations concerning rule-like imperatives and Ross' Paradox. The analysis is carried out within an agent-based logical framework. This analysis explicates what it means for an agent to have a successful policy for action with respect to satisfying his or her commitments, where some of these commitments have been introduced as a result of imperative language use

    On the current correlators in QCD at finite temperature

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    Current correlators in QCD at a finite temperature TT are considered from the viewpoint of operator product expansion. It is stressed that at low TT the heat bath must be represented by hadronic, and not quark-gluon states. A possibility to express the results in terms of TT-dependent resonance masses is discussed. It is demonstrated that in order T2T^2 the masses do not move and the only phenomenon which occurs is a parity and isospin mixing.Comment: 6 pages, TPI-MINN-92/64-
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