The Relation Between Managed Care Market Share and the Treatment of Elderly Fee-For-Service Patients with Myocardial Infarction

Managed care may affect medical treatments for non-managed-care patients if it alters local market structure or physician behavior. We investigate whether higher levels of overall managed care market share are associated with greater use of recommended therapies for fee-for-service patients with acute myocardial infarction using data on 112,900 fee-for-service Medicare beneficiaries residing in one of 320 metropolitan statistical areas, with age >= 65 years, and admitted with an acute myocardial infarction between February 1994 and July 1995 from the Cooperative Cardiovascular Project. After adjustment for patient characteristics, severity of illness, characteristics of the hospital of admission, specialty of treating physicians, and other area characteristics, patients treated in areas with high levels of managed care had greater relative use of beta-blockers during hospitalization and at discharge and aspirin during hospitalization and at discharge, consistent with more appropriate care. Patients in high HMO areas may be less likely to receive angiography when compared to areas with low levels of managed care, although this result was only marginally significant. In unadjusted comparisons, patients in high HMO market share areas had lower 30 day mortality, but there were no differences in 30 day mortality when all of the control variables were included in the model. We conclude that managed care can have widespread effects on the treatment of patients and the quality of care they receive, even for patients not enrolled in managed care organizations.

CDTI target selection criteria

A Cockpit Display of Traffic Information (CDTI) is a cockpit instrument which provides information to the aircrew on the relative location of aircraft traffic in the vicinity of their aircraft (township). In addition, the CDTI may provide information to assist in navigation and in aircraft control. It is usually anticipated that the CDTI will be integrated with a horizontal situation indicator used for navigational purposes and/or with a weather radar display. In this study, several sets of aircraft traffic data are analyzed to determine statistics on the number of targets that will be displayed on a CDTI using various target selection criteria. Traffic data were obtained from an Atlanta Terminal Area Simulation and from radar tapes recorded at the Atlanta and Miami terminal areas. Results are given in the form of plots showing the average percentage of time (or probability) that an aircraft equipped with a CDTI would observe from 0 to 10 other aircraft on the display for range settings on the CDTI up to 30 n. mi. and using various target discrimination techniques

Effective Control of Chronic γ-Herpesvirus Infection by Unconventional MHC Class Ia–Independent CD8 T Cells

Control of virus infection is mediated in part by major histocompatibility complex (MHC) Class Ia presentation of viral peptides to conventional CD8 T cells. Although important, the absolute requirement for MHC Class Ia–dependent CD8 T cells for control of chronic virus infection has not been formally demonstrated. We show here that mice lacking MHC Class Ia molecules (K(b−/−)xD(b−/−) mice) effectively control chronic γ-herpesvirus 68 (γHV68) infection via a robust expansion of β(2)-microglobulin (β(2)-m)-dependent, but CD1d-independent, unconventional CD8 T cells. These unconventional CD8 T cells expressed: (1) CD8αβ and CD3, (2) cell surface molecules associated with conventional effector/memory CD8 T cells, (3) TCRαβ with a significant Vβ4, Vβ3, and Vβ10 bias, and (4) the key effector cytokine interferon-γ (IFNγ). Unconventional CD8 T cells utilized a diverse TCR repertoire, and CDR3 analysis suggests that some of that repertoire may be utilized even in the presence of conventional CD8 T cells. This is the first demonstration to our knowledge that β(2)-m–dependent, but Class Ia–independent, unconventional CD8 T cells can efficiently control chronic virus infection, implicating a role for β(2)-n–dependent non-classical MHC molecules in control of chronic viral infection. We speculate that similar unconventional CD8 T cells may be able to control of other chronic viral infections, especially when viruses evade immunity by inhibiting generation of Class Ia–restricted T cells

The equation of state of solid nickel aluminide

The pressure-volume-temperature equation of state of the intermetallic compound NiAl was calculated theoretically, and compared with experimental measurements. Electron ground states were calculated for NiAl in the CsCl structure, using density functional theory, and were used to predict the cold compression curve and the density of phonon states. The Rose form of compression curve was found to reproduce the ab initio calculations well in compression but exhibited significant deviations in expansion. A thermodynamically-complete equation of state was constructed for NiAl. Shock waves were induced in crystals of NiAl by the impact of laser-launched Cu flyers and by launching NiAl flyers into transparent windows of known properties. The TRIDENT laser was used to accelerate the flyers to speeds between 100 and 600m/s. Point and line-imaging laser Doppler velocimetry was used to measure the acceleration of the flyer and the surface velocity history of the target. The velocity histories were used to deduce the stress state, and hence states on the principal Hugoniot and the flow stress. Flyers and targets were recovered from most experiments. The effect of elasticity and plastic flow in the sample and window was assessed. The ambient isotherm reproduced static compression data very well, and the predicted Hugoniot was consistent with shock compression data

Quantum critical behavior in the heavy Fermion single crystal Ce(Ni0.935_{0.935}Pd0.065_{0.065})2_2Ge2_2

We have performed magnetic susceptibility, specific heat, resistivity, and inelastic neutron scattering measurements on a single crystal of the heavy Fermion compound Ce(Ni$_{0.935}$Pd$_{0.065}$)$_2$Ge$_2$, which is believed to be close to a quantum critical point (QCP) at T = 0. At lowest temperature(1.8-3.5 K), the magnetic susceptibility behaves as $\chi(T)-\chi (0)$ $\propto$ $T^{-1/6}$ with $\chi (0) = 0.032 \times 10^{-6}$ m$^3$/mole (0.0025 emu/mole). For $T<$ 1 K, the specific heat can be fit to the formula $\Delta C/T = \gamma_0 - T^{1/2}$ with $\gamma_0$ of order 700 mJ/mole-K$^2$. The resistivity behaves as $\rho = \rho_0 + AT^{3/2}$ for temperatures below 2 K. This low temperature behavior for $\gamma (T)$ and $\rho (T)$ is in accord with the SCR theory of Moriya and Takimoto\cite{Moriya}. The inelastic neutron scattering spectra show a broad peak near 1.5 meV that appears to be independent of $Q$; we interpret this as Kondo scattering with $T_K =$ 17 K. In addition, the scattering is enhanced near $Q$=(1/2, 1/2, 0) with maximum scattering at $\Delta E$ = 0.45 meV; we interpret this as scattering from antiferromagnetic fluctuations near the antiferromagnetic QCP.Comment: to be published in J. Phys: Conference Serie

Factors associated with cognitive achievement in late childhood and adolescence: the Young Lives cohort study of children in Ethiopia, India, Peru, and Vietnam

Background There is a well-established link between various measures of socioeconomic status and the schooling achievement and cognition of children. However, less is known about how cognitive development is impacted by childhood improvements in growth, a common indicator of child nutritional status. This study examines the relationship between socioeconomic status and child growth and changes in cognitive achievement scores in adolescents from resource-poor settings. Methods Using an observational cohort of more than 3000 children from four low- and middle-income countries, this study examines the association between cognitive achievement scores and household economic, educational, and nutritional resources to give a more accurate assessment of the influence of families on cognitive development. A composite measure of cognition when children were approximately 8, 12, and 15 years of age was constructed. Household factors included maternal schooling, wealth, and children’s growth. Results A positive and statistically significant relationship between household factors and child cognition was found for each country. If parents have more schooling, household wealth increases, or child growth improves, then children’s cognitive scores improve over time. Results for control variables are less consistent. Conclusion Our findings suggest there is a consistent and strong association between parental schooling, wealth, and child growth with child cognitive achievement. Further, these findings demonstrate that a household’s ability to provide adequate nutrition is as important as economic and education resources even into late childhood and adolescence. Hence, efforts to improve household resources, both early in a child’s life and into adolescence, and to continue to promote child growth beyond the first few years of life have the potential to help children over the life course by improving cognition

Positron-molecule interactions: resonant attachment, annihilation, and bound states

This article presents an overview of current understanding of the interaction of low-energy positrons with molecules with emphasis on resonances, positron attachment and annihilation. Annihilation rates measured as a function of positron energy reveal the presence of vibrational Feshbach resonances (VFR) for many polyatomic molecules. These resonances lead to strong enhancement of the annihilation rates. They also provide evidence that positrons bind to many molecular species. A quantitative theory of VFR-mediated attachment to small molecules is presented. It is tested successfully for selected molecules (e.g., methyl halides and methanol) where all modes couple to the positron continuum. Combination and overtone resonances are observed and their role is elucidated. In larger molecules, annihilation rates from VFR far exceed those explicable on the basis of single-mode resonances. These enhancements increase rapidly with the number of vibrational degrees of freedom. While the details are as yet unclear, intramolecular vibrational energy redistribution to states that do not couple directly to the positron continuum appears to be responsible for these enhanced annihilation rates. Downshifts of the VFR from the vibrational mode energies have provided binding energies for thirty species. Their dependence upon molecular parameters and their relationship to positron-atom and positron-molecule binding energy calculations are discussed. Feshbach resonances and positron binding to molecules are compared with the analogous electron-molecule (negative ion) cases. The relationship of VFR-mediated annihilation to other phenomena such as Doppler-broadening of the gamma-ray annihilation spectra, annihilation of thermalized positrons in gases, and annihilation-induced fragmentation of molecules is discussed.Comment: 50 pages, 40 figure