Spin-orbit and impurity scattering in an integrable electron model: Exact results for dynamic correlations

We introduce an integrable model of spin-polarized interacting electrons subject to a spin-conserving spin-orbit interaction. Using Bethe Ansatz and conformal field theory we calculate the exact large-time single-electron and density correlations and find that while the spin-orbit interaction enhances the single-electron Green's function, the density correlations get suppressed. Adding a localized impurity and coupling it to the electrons so that integrability is preserved, the dynamic correlations are found to change significantly after a quantum quench with the impurity interaction switched on suddenly. When the electrons are confined to a periodic structure, the correlations are indifferent to the location of the impurity and only carry an imprint of its intrinsic properties. We conjecture that this unusual feature originates from the integrability of the model.Comment: 8 pages, 1 figur

Reproduction of the Lyman α irradiance variability from analysis of full-disk images in the CaII K-line

We have compared three years of daily CaII K-line images from the Big Bear Solar Observatory (BBSO) with HI Lymanα irradiance data from the Upper Atmosphere Research Satellite (UARS). The daily full-disk CaII K-line images are reduced to a new index of integrated excess emission, which reproduces both the 27 day rotational modulation and the solar cycle decrease in Lyα irradiance. Our analysis shows that while plages reproduce the 27-day variation quite well, the total K-line emission excess above the quiet background is needed to reproduce the secular solar cycle trend in the Lyα irradiance. The resulting K-line index exhibits a high degree of correlation (0.9) with the time series of measured Lyα flux

Is Misoprostol Cost-effective in the Prevention of Nonsteroidal Anti-inflammatory Drug—Induced Gastropathy in Patients With Chronic Arthritis?

Whether misoprostol, a synthetic prostaglandin E1 analogue, should be routinely prescribed along with nonsteriodal anti-inflammatory drugs (NSAIDS) to prevent gastric damage is of great clinical importance and has profound cost implications. No consensus exists on whether misoprostol cotherapy results in a cost-saving, is cost-effective, or is costly. The different conclusions reached by five economic evaluations of misoprostol can be explained solely by the assumed absolute risk reduction of symptomatic ulcer, which was more than seven times greater in the studies that concluded that misoprostol was cost-effective than in a study that concluded misoprostol to be costly. Since no study has directly shown the effectiveness of misoprostol cotherapy in preventing clinically significant ulcer disease (ie, hemorrhage and preforation), it is impossible to judge which assumptions are most appropriate. The absence of firm data on the rate of NSAID-induced gastric ulcers reduced by misoprostol makes it impossible to conclude whether it is cost-effective in patients with chronic arthritis who use NSAIDS

Addendum to ``Multichannel Kondo screening in a one-dimensional correlated electron system''

This is an addendum to our previous work cond-mat/9705048 (published in Europhysics Letters 41, 213 (1998)), clarifying the construction of the two-particle scattering matrices used for studying the magnetic impurity behavior in a multichannel correlated host.Comment: Addendum to cond-mat/9705048 (Europhys. Lett. 41, 213 (1998)

Renormalization Group Approach to Spectral Properties of the Two-Channel Anderson Impurity Model

The impurity Green function and dynamical susceptibilties for the two-channel Anderson impurity model are calculated. An exact expression for the self-energy of the impurity Green function is derived. The imaginary part of the self-energy scales as \sqrt{|\w/T_K|} for $T\to 0$ serving as a hallmark for non-Fermi behavior. The many-body resonance is pinned to a universal value $1/(2\pi\Delta)$ at \w=0. Its shape becomes increasingly more symmetric for the Kondo-regimes of the model. The dynamical susceptibilities are governed by two energy scales $T_K$ and $T_h$ and approach a constant value for \w\to 0, whereas relation \chi''(\w)\propto \w holds for the single channel model.Comment: 4 pages, 4 figure, revte

Standard gamble, time trade-off and rating scale: Experimental results on the ranking properties of QALYs

This paper compares the relative performance of quality adjusted life years (QALYs) based on quality weights elicited by rating scale (RS), time trade-off (TTO) and standard gamble (SG). The standard against which relative performance is assessed is individual preference elicited by direct ranking. The correlation between predicted and direct ranking is significantly higher for TTO-QALYs than for RS-QALYs and SG-QALYs. This holds both based on mean Spearman rank correlation coefficients calculated per individual and based on two social choice rules: the method of majority voting and the Borda rule. Undiscounted TTO-QALYs are more consistent with direct ranking than discounted TTO-QALY