325 research outputs found

    Theory for polymer coils with necklaces of micelles

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    If many micelles adsorb onto the same polymer molecule then they are said to form a necklace. A minimal model of such a necklace is proposed and shown to be almost equivalent to a 1-dimensional fluid with nearest-neighbour interactions. The thermodynamic functions of this fluid are obtained and then used to predict the change in the critical micellar concentration of the surfactant in the presence of the polymer. If the amount of polymer is not too large there are two critical micellar concentrations, one for micelles in necklaces and one for free micelles.Comment: 12 pages, 5 figure

    Manipulation of the follicular phase: Uterodomes and pregnancy - is there a correlation?

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    BACKGROUND: Manipulation of the follicular phase uterine epithelium in women undergoing infertility treatment, has not generally shown differing morphological effects on uterine epithelial characteristics using Scanning Electron Microscopy (SEM) and resultant pregnancy rates have remained suboptimal utilising these manipulations. The present study observed manipulation of the proliferative epithelium, with either 7 or 14 days of sequential oestrogen (E) therapy followed by progesterone (P) and assessed the appearance of pinopods (now called uterodomes) for their usefulness as potential implantation markers in seven women who subsequently became pregnant. Three endometrial biopsies per patient were taken during consecutive cycles: day 19 of a natural cycle - (group 1), days 11/12 of a second cycle after 7 days E then P - (group 2), and days 19/22 of a third cycle after 14 days E then P - (group 3). Embryo transfer (ET) was performed in a subsequent long treatment cycle (as per Group 3). RESULTS: Seven pregnancies resulted in seven viable births including one twins and one miscarriage. Analysis of the individual regimes showed 5 days of P treatment to have a higher correlation for uterodomes in all 3 cycles observed individually. It was also observed that all 7 women demonstrated the appearance of uterodomes in at least one of their cycles. CONCLUSIONS: We conclude that manipulation of the follicular phase by shortening the period of E exposure to 7 days, does not compromise uterine epithelial morphology and we add weight to the conclusion that uterodomes indicate a receptive endometrium for implantation

    Search for Lorentz and CPT Violation Effects in Muon Spin Precession

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    The spin precession frequency of muons stored in the (g−2)(g-2) storage ring has been analyzed for evidence of Lorentz and CPT violation. Two Lorentz and CPT violation signatures were searched for: a nonzero Δωa\Delta\omega_{a} (=ωaμ+−ωaμ−\omega_{a}^{\mu^{+}}-\omega_{a}^{\mu^{-}}); and a sidereal variation of ωaμ±\omega_{a}^{\mu^{\pm}}. No significant effect is found, and the following limits on the standard-model extension parameters are obtained: bZ=−(1.0±1.1)×10−23b_{Z} =-(1.0 \pm 1.1)\times 10^{-23} GeV; (mμdZ0+HXY)=(1.8±6.0×10−23)(m_{\mu}d_{Z0}+H_{XY}) = (1.8 \pm 6.0 \times 10^{-23}) GeV; and the 95% confidence level limits bˇ⊥μ+<1.4×10−24\check{b}_{\perp}^{\mu^{+}}< 1.4 \times 10^{-24} GeV and bˇ⊥μ−<2.6×10−24\check{b}_{\perp}^{\mu^{-}} < 2.6 \times 10^{-24} GeV.Comment: 5 pages, 3 figures, submitted to Physical Review Letters, Modified to answer the referees suggestion

    Final Report of the Muon E821 Anomalous Magnetic Moment Measurement at BNL

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    We present the final report from a series of precision measurements of the muon anomalous magnetic moment, a_mu = (g-2)/2. The details of the experimental method, apparatus, data taking, and analysis are summarized. Data obtained at Brookhaven National Laboratory, using nearly equal samples of positive and negative muons, were used to deduce a_mu(Expt) = 11 659 208.0(5.4)(3.3) x 10^-10, where the statistical and systematic uncertainties are given, respectively. The combined uncertainty of 0.54 ppm represents a 14-fold improvement compared to previous measurements at CERN. The standard model value for a_mu includes contributions from virtual QED, weak, and hadronic processes. While the QED processes account for most of the anomaly, the largest theoretical uncertainty, ~0.55 ppm, is associated with first-order hadronic vacuum polarization. Present standard model evaluations, based on e+e- hadronic cross sections, lie 2.2 - 2.7 standard deviations below the experimental result.Comment: Summary paper of E821 Collaboration measurements of the muon anomalous magnetic moment, each reported earlier in Letters or Brief Reports; 96 pages, 41 figures, 16 tables. Revised version submitted to PR

    News from the Muon (g-2) Experiment at BNL

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    The magnetic moment anomaly a_mu = (g_mu - 2) / 2 of the positive muon has been measured at the Brookhaven Alternating Gradient Synchrotron with an uncertainty of 0.7 ppm. The new result, based on data taken in 2000, agrees well with previous measurements. Standard Model evaluations currently differ from the experimental result by 1.6 to 3.0 standard deviations.Comment: Talk presented at RADCOR - Loops and Legs 2002, Kloster Banz, Germany, September 8-13 2002, to be published in Nuclear Physics B (Proc. Suppl.); 5 pages, 3 figure

    An Improved Limit on the Muon Electric Dipole Moment

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    Three independent searches for an electric dipole moment (EDM) of the positive and negative muons have been performed, using spin precession data from the muon g-2 storage ring at Brookhaven National Laboratory. Details on the experimental apparatus and the three analyses are presented. Since the individual results on the positive and negative muon, as well as the combined result, d=-0.1(0.9)E-19 e-cm, are all consistent with zero, we set a new muon EDM limit, |d| < 1.9E-19 e-cm (95% C.L.). This represents a factor of 5 improvement over the previous best limit on the muon EDM.Comment: 19 pages, 15 figures, 7 table

    Search for Lorentz and CPT Violation Effects in Muon Spin Precession

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    The spin precession frequency of muons stored in the (g−2)(g-2) storage ring has been analyzed for evidence of Lorentz and CPT violation. Two Lorentz and CPT violation signatures were searched for: a nonzero Δωa\Delta\omega_{a} (=ωaμ+−ωaμ−\omega_{a}^{\mu^{+}}-\omega_{a}^{\mu^{-}}); and a sidereal variation of ωaμ±\omega_{a}^{\mu^{\pm}}. No significant effect is found, and the following limits on the standard-model extension parameters are obtained: bZ=−(1.0±1.1)×10−23b_{Z} =-(1.0 \pm 1.1)\times 10^{-23} GeV; (mμdZ0+HXY)=(1.8±6.0×10−23)(m_{\mu}d_{Z0}+H_{XY}) = (1.8 \pm 6.0 \times 10^{-23}) GeV; and the 95% confidence level limits bˇ⊥μ+<1.4×10−24\check{b}_{\perp}^{\mu^{+}}< 1.4 \times 10^{-24} GeV and bˇ⊥μ−<2.6×10−24\check{b}_{\perp}^{\mu^{-}} < 2.6 \times 10^{-24} GeV.Comment: 5 pages, 3 figures, submitted to Physical Review Letters, Modified to answer the referees suggestion
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