2,062 research outputs found
Mechanisms of Spontaneous Current Generation in an Inhomogeneous d-Wave Superconductor
A boundary between two d-wave superconductors or an s-wave and a d-wave
superconductor generally breaks time-reversal symmetry and can generate
spontaneous currents due to proximity effect. On the other hand, surfaces and
interfaces in d-wave superconductors can produce localized current-carrying
states by supporting the T-breaking combination of dominant and subdominant
order parameters. We investigate spontaneous currents in the presence of both
mechanisms and show that at low temperature, counter-intuitively, the
subdominant coupling decreases the amplitude of the spontaneous current due to
proximity effect. Superscreening of spontaneous currents is demonstrated to be
present in any d-d (but not s-d) junction and surface with d+id' order
parameter symmetry. We show that this supercreening is the result of
contributions from the local magnetic moment of the condensate to the
spontaneous current.Comment: 4 pages, 5 figures, RevTe
Medicaid as an Investment in Children: What is the Long-Term Impact on Tax Receipts?
We use administrative data from the IRS to examine the long-term impact of childhood Medicaid expansions. We use eligibility variation by cohort and state that we can relate to outcomes graphically. We find that children with greater Medicaid eligibility paid more in cumulative taxes by age 28. They collected less in EITC payments, and the women had higher cumulative wages. Our estimates imply that the government will recoup 56 cents of each dollar spent on childhood Medicaid by the time these children reach age 60. This return does not include estimated private gains from increased college attendance and decreased mortality
Electromagnetic multipole moments of elementary spin-1/2, 1, and 3/2 particles
We study multipole decompositions of the electromagnetic currents of
spin-1/2, 1, and 3/2 particles described in terms of Lagrangians designed to
reproduce representation specific wave equations which are second order in the
momenta and which emerge within the recently elaborated Poincar\'e covariant
projector method. We calculate the electric multipoles of the above spins for
the spinor, the four-vector, and the four-vector--spinor representations,
attend to the most general non-Lagrangian spin-3/2 currents which are allowed
by Lorentz invariance to be of third order in the momenta and construct the
linear current equivalent of identical multipole moments of one of them. We
conclude that such non-Lagrangian currents are not necessarily more general
than the two-term currents emerging within the covariant projector method. We
compare our results with those of the conventional Proca-, and Rarita-Schwinger
frameworks. Finally, we test the representation dependence of the multipoles by
placing spin-1 and spin-3/2 in the respective (1,0)(0,1), and
(3/2,0)(0,3/2) single-spin representations. We observe representation
independence of the charge monopoles and the magnetic dipoles, in contrast to
the higher multipoles, which turn out to be representation dependent. In
particular, we find the bi-vector to be characterized by an
electric quadrupole moment of opposite sign to the one found in ,
and consequently, to the boson. Our finding points toward the possibility
that the meson could transform as part of an antisymmetric tensor with
an meson-like state as its representation companion.Comment: 27 pages, 2 figure
Developing predictive models of health literacy.
IntroductionLow health literacy (LHL) remains a formidable barrier to improving health care quality and outcomes. Given the lack of precision of single demographic characteristics to predict health literacy, and the administrative burden and inability of existing health literacy measures to estimate health literacy at a population level, LHL is largely unaddressed in public health and clinical practice. To help overcome these limitations, we developed two models to estimate health literacy.MethodsWe analyzed data from the 2003 National Assessment of Adult Literacy (NAAL), using linear regression to predict mean health literacy scores and probit regression to predict the probability of an individual having 'above basic' proficiency. Predictors included gender, age, race/ethnicity, educational attainment, poverty status, marital status, language spoken in the home, metropolitan statistical area (MSA) and length of time in U.S.ResultsAll variables except MSA were statistically significant, with lower educational attainment being the strongest predictor. Our linear regression model and the probit model accounted for about 30% and 21% of the variance in health literacy scores, respectively, nearly twice as much as the variance accounted for by either education or poverty alone.ConclusionsMultivariable models permit a more accurate estimation of health literacy than single predictors. Further, such models can be applied to readily available administrative or census data to produce estimates of average health literacy and identify communities that would benefit most from appropriate, targeted interventions in the clinical setting to address poor quality care and outcomes related to LHL
International Health Regulations
On Tuesday, April 6, 2010, the George Washington University School of Public Health and Health Services (GW SPHHS) hosted the annual Southby Distinguished Lectureship in Comparative Health Policy on the International Health Regulations. This lectureship gave an overview of the U.S. Government\u27s approach to addressing the challenges, policies, and opportunities related to both domestic and international implementation of the IHR (2005).
Introductory remarks were given by GW School of Public Health faculty, including Josef Reum, Interim Dean; Professor Sara Rosenbaum, Chair of the Department of Health Policy & Hirsh Professor of Health Law and Policy; Richard Southby, Executive Dean Emeritus; and Rebecca Katz, Assistant Professor, Department of Health Policy.
The plenary speakers were Mr. Andrew Weber, Assistant to the Secretary of Defense for Nuclear, Chemical and Biological Defense Programs at the Department of Defense; Dr. Nicole Lurie, Assistant Secretary for Preparedness and Response at the Department of Health and Human Services; and Dr. Scott Dowell, Director of the Global Disease Detection Program at the Centers for Disease Control and Prevention.
The discussants were: Dr. Julie Fischer, Stimson Center; Ms. Jennifer Kates, Kaiser Family Foundation; and Dr. Stephen Morrison, Center for Strategic and International Studies
Space power distribution system technology. Volume 2: Autonomous power management
Electrical power subsystem requirements, power management system functional requirements, algorithms, power management subsystem, hardware development, and trade studies and analyses are discussed
Space power distribution system technology. Volume 1: Reference EPS design
The multihundred kilowatt electrical power aspects of a mannable space platform in low Earth orbit is analyzed from a cost and technology viewpoint. At the projected orbital altitudes, Shuttle launch and servicing are technically and economically viable. Power generation is specified as photovoltaic consistent with projected planning. The cost models and trades are based upon a zero interest rate (the government taxes concurrently as required), constant dollars (1980), and costs derived in the first half of 1980. Space platform utilization of up to 30 years is evaluated to fully understand the impact of resupply and replacement as satellite missions are extended. Such lifetimes are potentially realizable with Shuttle servicing capability and are economically desirable
Inexperienced clinicians can extract pathoanatomic information from MRI narrative reports with high reproducibility for use in research/quality assurance
<p>Abstract</p> <p>Background</p> <p>Although reproducibility in reading MRI images amongst radiologists and clinicians has been studied previously, no studies have examined the reproducibility of inexperienced clinicians in extracting pathoanatomic information from magnetic resonance imaging (MRI) narrative reports and transforming that information into quantitative data. However, this process is frequently required in research and quality assurance contexts. The purpose of this study was to examine inter-rater reproducibility (agreement and reliability) among an inexperienced group of clinicians in extracting spinal pathoanatomic information from radiologist-generated MRI narrative reports.</p> <p>Methods</p> <p>Twenty MRI narrative reports were randomly extracted from an institutional database. A group of three physiotherapy students independently reviewed the reports and coded the presence of 14 common pathoanatomic findings using a categorical electronic coding matrix. Decision rules were developed after initial coding in an effort to resolve ambiguities in narrative reports. This process was repeated a further three times using separate samples of 20 MRI reports until no further ambiguities were identified (total n = 80). Reproducibility between trainee clinicians and two highly trained raters was examined in an arbitrary coding round, with agreement measured using percentage agreement and reliability measured using unweighted Kappa (<it>k</it>). Reproducibility was then examined in another group of three trainee clinicians who had not participated in the production of the decision rules, using another sample of 20 MRI reports.</p> <p>Results</p> <p>The mean percentage agreement for paired comparisons between the initial trainee clinicians improved over the four coding rounds (97.9-99.4%), although the greatest improvement was observed after the first introduction of coding rules. High inter-rater reproducibility was observed between trainee clinicians across 14 pathoanatomic categories over the four coding rounds (agreement range: 80.8-100%; reliability range <it>k </it>= 0.63-1.00). Concurrent validity was high in paired comparisons between trainee clinicians and highly trained raters (agreement 97.8-98.1%, reliability <it>k </it>= 0.83-0.91). Reproducibility was also high in the second sample of trainee clinicians (inter-rater agreement 96.7-100.0% and reliability <it>k </it>= 0.76-1.00; intra-rater agreement 94.3-100.0% and reliability <it>k </it>= 0.61-1.00).</p> <p>Conclusions</p> <p>A high level of radiological training is not required in order to transform MRI-derived pathoanatomic information from a narrative format to a quantitative format with high reproducibility for research or quality assurance purposes.</p
Neighborhood Effects on Health: Concentrated Advantage and Disadvantage
We investigate an alternative conceptualization of neighborhood context and its association with health. Using an index that measures a continuum of concentrated advantage and disadvantage, we examine whether the relationship between neighborhood conditions and health varies by socio-economic status. Using NHANES III data geo-coded to census tracts, we find that while largely uneducated neighborhoods are universally deleterious, individuals with more education benefit from living in highly educated neighborhoods to a greater degree than individuals with lower levels of education
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