Race, Ethnicity and the Dynamics of Health Insurance Coverage

Using matched data from the 1996 to 2004 Current Population Survey (CPS), we examine racial patterns in annual transitions into and out of health insurance coverage. We first decompose racial differences in static health insurance coverage rates into group differences in transition rates into and out of health insurance coverage. The low rate of health insurance coverage among African-Americans is due almost entirely to higher annual rates of losing health insurance than whites. Among the uninsured, African-Americans have similar rates of gaining health insurance in the following year as whites. Estimates from the matched CPS also indicate that the lower rate of health insurance coverage among Asians is almost entirely accounted for by a relatively high rate of losing health insurance. In contrast to these findings, differences in health insurance coverage between Latinos and whites are due to group differences in both the rate of health insurance loss and gain. Using logit regression estimates, we also calculate non-linear decompositions for the racial gaps in health insurance loss and gain. We find that two main factors are responsible for differences in health insurance loss between working-age whites and minorities: job loss and education level. Higher rates of job loss account for 30 percent of the health insurance gap for African-Americans and Asians, and 16 percent of the health insurance gap for Latinos. Lower levels of education explain roughly 15 percent of the gap for African-Americans and Latinos (Asians' higher levels of education serve to close the gap). Higher rates of welfare and SSI participation among African-Americans also serve to widen the gap in health insurance loss by 8 percent.race, health insurance, insurance dynamics

Mission Capabilities of Ion Engines Using SNAP-8 Power Supplies

Mission performance capabilities of ion engines powered by the 30 kw and 60 kw SNAP-8 power supplies are compared for the following missions: a 24-hr equatorial satellite, a 100 n mi lunar satellite, a 500 n mi Mars satellite, a Mercury probe, and an out-of-the-ecliptic probe. The capabilities of arc- jet engines and chemical engines for the same missions are compared with those of the ion engines. The majority of the comparisons are for 8500-lb spacecraft which are boosted into a 300 n mi orbit by the Atlas-Centaur. Variations in initial orbit altitude, the use of actual launch dates rather than dates based on simplifying assumptions, and the combined use of chemical and electrical propulsion systems were also evaluated in terms of their effect on mission performance

Modeling the strategic trading of electricity assets

We analyze how strategic asset trading can be used to gain competitive advantage. In the case of electricity markets, companies seek to improve the value of their generating portfolios by acquiring, or selling, power plants. Accordingly, we derive the basic determinants of plant value, explaining how a particular productive asset may have different values for different firms. From this, we develop an evolutionary model to understand how market structure interacts with strategic asset trading to increase the competitive advantage of firms, and furthermore, how this depends upon the actual price-setting microstructure in the wholesale market itselfCompetitive advantage, computational learning, auctions, asset trading, simulation, electricity markets

Mission Capabilities of Ion Engines. Phase II

Payloads and mission times were calculated for space vehicles propelled by ion rockets using nuclear power supplies having specific weights from 10 t o 50 lb/kw. Included in the study were five missions: low-altitude lunar satellite, low-altitude Venus satellite, solar probe, Saturn probe, and a Jupiter satellite with a circular orbit at the altitude of Jupiter's fourth moon. The variation of payload with the ration of power supply weight to gross weight was studied and the optimum power levels thereby determined. The ion rocket payload capabilities were compared with those of high-thrust vehicles using hydrogen-oxygen rockets and tungsten-core nuclear rockets; in addition the performance of high- and low-thrust systems staged in combination has been investigated. Launch vehicles considered in this study were the Atlas-Centaur, the Saturn C-1, and the Saturn C-5

Disorder Effects in Fluctuating One-Dimensional Interacting Systems

The zero temperature localization of interacting electrons coupled to a two-dimensional quenched random potential, and constrained to move on a fluctuating one-dimensional string embedded in the disordered plane, is studied using a perturbative renormalization group approach. In the reference frame of the electrons the impurities are dynamical and their localizing effect is expected to decrease. We consider several models for the string dynamics and find that while the extent of the delocalized regime indeed grows with the degree of string fluctuations, the critical interaction strength, which determines the localization-delocalization transition for infinitesimal disorder,does not change unless the fluctuations are softer than those of a simple elastic string.Comment: 15 page

Spin currents in superconductors

It is argued that experiments on rotating superconductors provide evidence for the existence of macroscopic spin currents in superconductors in the absence of applied external fields. Furthermore it is shown that the model of hole superconductivity predicts the existence of such currents in all superconductors. In addition it is pointed out that spin currents are required within a related macroscopic (London-like) electrodynamic description of superconductors recently proposed. The spin current arises through an intrinsic spin Hall effect when negative charge is expelled from the interior of the metal upon the transition to the superconducting state

A generic multi-flex-body dynamics, controls simulation tool for space station

An order (n) multiflex body Space Station simulation tool is introduced. The flex multibody modeling is generic enough to model all phases of Space Station from build up through to Assembly Complete configuration and beyond. Multibody subsystems such as the Mobile Servicing System (MSS) undergoing a prescribed translation and rotation are also allowed. The software includes aerodynamic, gravity gradient, and magnetic field models. User defined controllers can be discrete or continuous. Extensive preprocessing of 'body by body' NASTRAN flex data is built in. A significant aspect, too, is the integrated controls design capability which includes model reduction and analytic linearization

Academic Primer Series: Five Key Papers for Consulting Clinician Educators.

INTRODUCTION: Clinician educators are often asked to perform consultations for colleagues. Invitations to consult and advise others on local problems can help foster great collaborations between centers, and allows for an exchange of ideas between programs. In this article, the authors identify and summarize several key papers to assist emerging clinician educators with the consultation process. METHODS: A consensus-building process was used to generate a list of key papers that describe the importance and significance of educational consulting, informed by social media sources. A three-round voting methodology, akin to a Delphi study, determined the most impactful papers from the larger list. RESULTS: Summaries of the five most highly rated papers on education consultation are presented in this paper. These papers were determined by a mixed group of junior and senior faculty members, who have summarized these papers with respect to their relevance for their peer groups. CONCLUSION: Five key papers on the educational consultation process are presented in this paper. These papers offer background and perspective to help junior faculty gain a grasp of consultation processes

Implications of observation-fact modifiers to i2b2 ontologies

Biomedical translational research can be facilitated by integrating clinical and research data. In particular, study cohort identification and hypothesis generation is enabled by the mining of integrated clinical observations and research resources. The informatics for integrating biology and the bedside, or i2b2, framework is widely used for this biomedical data mining. The i2b2 star schema data model using entity-attribute-value (EA V) formatted concepts is a very efficient strategy for querying large amounts of data. However, until the most recent i2b2 release, the utility of the platform was somewhat constrained by the limitations on being able to express facts about facts - i.e., modify the observations about the patients. We have found that exploiting the new modifier functionality has significantly and favorably impacted the design of i2b2 ontologies, leading to easier and more meaningful query results. Copyright © 2011 IEEE