The evolving maintenance of certification process: update on the financial status of the medical boards

Medical board organizations have accumulated large asset balances, in part due to the monetization of physician board recertification, as well as capital gains in positive investment conditions. Physicians across the country have raised concerns regarding the effectiveness and efficiency of existing recertification processes, to which the American Board of Medical Specialties and independent accreditation boards have responded with newly instituted changes. The present article analyzes the publicly available F990 tax forms of the medical boards in an effort to provide data to the ongoing debate. Although some boards have begun to mobilize assets in recent years, many continue to accumulate wealth. It remains to be seen whether the new recertification programs will bring about change or perpetuate organizational wealth

Unlimited simultaneous discrimination intervals in regression Technical report no. 90

Unlimited simultaneous discrimination intervals in linear regression

Temporal Analysis of Activity Patterns of Editors in Collaborative Mapping Project of OpenStreetMap

In the recent years Wikis have become an attractive platform for social studies of the human behaviour. Containing millions records of edits across the globe, collaborative systems such as Wikipedia have allowed researchers to gain a better understanding of editors participation and their activity patterns. However, contributions made to Geo-wikis_wiki-based collaborative mapping projects_ differ from systems such as Wikipedia in a fundamental way due to spatial dimension of the content that limits the contributors to a set of those who posses local knowledge about a specific area and therefore cross-platform studies and comparisons are required to build a comprehensive image of online open collaboration phenomena. In this work, we study the temporal behavioural pattern of OpenStreetMap editors, a successful example of geo-wiki, for two European capital cities. We categorise different type of temporal patterns and report on the historical trend within a period of 7 years of the project age. We also draw a comparison with the previously observed editing activity patterns of Wikipedia.Comment: Submitte

Energy balance in a low pressure capacitive discharge driven by a double-saddle antenna

A radio frequency (rf) plasma is created at low pressure (∼1 mTorr) in the source tube of a “helicon” excited diffusion system in the absence of a dc magnetic field. The coupling is capacitive for the low source power of 160 W at 13.56 MHz considered here. Temperature measurements of the glass source tube yield a plasma power deposition of ∼35 W. The plasma parameters (density, potential, electron temperature) were measured using a retarding field energy analyzer. An analytical model based on the measuredplasma parameters and on additional external parameters measured in the matching box (rf voltages and phase, rf current) is developed. The model takes into account the geometry of the double saddle rf antenna. It is found that the inside of the glass wall adjacent to the antenna wire charges negatively. Ion acceleration into the glass along the antenna and fast electrons escaping the plasma account for most of the power deposition to the walls (∼16.8 W). Secondary electrons liberated by ions impinging onto the glass along the antenna contribute a power of ∼4.6 W. Adding the power of 3.7 W deposited to the part of the tube not affected by the antenna, the total power deposition responsible for the temperature rise of the tube is found to be about 25 W. The model shows that the power deposition is strongly nonuniform along the tube as a result of the antenna geometry. An estimate of the power deposited into the electrons by stochastic heating yields ∼1.4 W, compared to an estimate of 5.8 W for the measured power loss from electrons

Oseledets' Splitting of Standard-like Maps

For the class of differentiable maps of the plane and, in particular, for standard-like maps (McMillan form), a simple relation is shown between the directions of the local invariant manifolds of a generic point and its contribution to the finite-time Lyapunov exponents (FTLE) of the associated orbit. By computing also the point-wise curvature of the manifolds, we produce a comparative study between local Lyapunov exponent, manifold's curvature and splitting angle between stable/unstable manifolds. Interestingly, the analysis of the Chirikov-Taylor standard map suggests that the positive contributions to the FTLE average mostly come from points of the orbit where the structure of the manifolds is locally hyperbolic: where the manifolds are flat and transversal, the one-step exponent is predominantly positive and large; this behaviour is intended in a purely statistical sense, since it exhibits large deviations. Such phenomenon can be understood by analytic arguments which, as a by-product, also suggest an explicit way to point-wise approximate the splitting.Comment: 17 pages, 11 figure

Testosterone Influence on Gene Expression in Lacrimal Glands of Mouse Models of Sjögren Syndrome

Purpose: Sjögren syndrome is an autoimmune disorder that occurs almost exclusively in women and is associated with extensive inflammation in lacrimal tissue, an immune-mediated destruction and/or dysfunction of glandular epithelial cells, and a significant decrease in aqueous tear secretion. We discovered that androgens suppress the inflammation in, and enhance the function of, lacrimal glands in female mouse models (e.g., MRL/MpJ-Tnfrsf6lpr [MRL/lpr]) of Sjögren syndrome. In contrast, others have reported that androgens induce an anomalous immunopathology in lacrimal glands of nonobese diabetic/LtJ (NOD) mice. We tested our hypothesis that these hormone actions reflect unique, strain- and tissue-specific effects, which involve significant changes in the expression of immune-related glandular genes. Methods: Lacrimal glands were obtained from age-matched, adult, female MRL/lpr and NOD mice after treatment with vehicle or testosterone for up to 3 weeks. Tissues were processed for analysis of differentially expressed mRNAs using CodeLink Bioarrays and Affymetrix GeneChips. Data were analyzed with bioinformatics and statistical software. Results: Testosterone significantly influenced the expression of numerous immune-related genes, ontologies, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in lacrimal glands of MRL/lpr and NOD mice. The nature of this hormone-induced immune response was dependent upon the autoimmune strain, and was not duplicated within lacrimal tissues of nonautoimmune BALB/c mice. The majority of immune-response genes regulated by testosterone were of the inflammatory type. Conclusions: Our findings support our hypothesis and indicate a major role for the lacrimal gland microenvironment in mediating androgen effects on immune gene expression

Xenon ion beam characterization in a helicon double layer thruster

A current-free electric double layer is created in a helicon double layer thruster operating with xenon and compared to a recently developed theory. The Xe⁺ion beam formed by acceleration through the potential drop of the double layer is characterized radially using an electrostatic ion energy analyzer. For operating conditions of 500W rf power, 0.07mTorr gas pressure, and a maximum magnetic field of 125G, the measuredbeamvelocity is about 6kms⁻¹, the beam area is about 150cm², and the measuredbeam divergence is less than 6°

Oxford Handbook Of American Political Development

Scholars working in or sympathetic to American political development (APD) share a commitment to accurately understanding the history of American politics – and thus they question stylized facts about America’s political evolution. Like other approaches to American politics, APD prizes analytical rigor, data collection, the development and testing of theory, and the generation of provocative hypotheses. Much APD scholarship indeed overlaps with the American politics subfield and its many well developed literatures on specific institutions or processes (for example Congress, judicial politics, or party competition), specific policy domains (welfare policy, immigration), the foundations of (in)equality in American politics (the distribution of wealth and income, race, ethnicity, gender, class, and sexual and gender orientation), public law, and governance and representation. What distinguishes APD is careful, systematic thought about the ways that political processes, civic ideals, the political construction of social divisions, patterns of identity formation, the making and implementation of public policies, contestation over (and via) the Constitution, and other formal and informal institutions and processes evolve over time – and whether (and how) they alter, compromise, or sustain the American liberal democratic regime. APD scholars identify, in short, the histories that constitute American politics. They ask: what familiar or unfamiliar elements of the American past illuminate the present? Are contemporary phenomena that appear new or surprising prefigured in ways that an APD approach can bring to the fore? If a contemporary phenomenon is unprecedented then how might an accurate understanding of the evolution of American politics unlock its significance

Electron heating mechanisms in dual frequency capacitive discharges

We discuss electron heating mechanisms in the sheath regions of dual-frequency capacitive discharges, with the twin aims of identifying the dominant mechanisms and supplying closed-form expressions from which the heating power can be estimated. We show that the heating effect produced by either Ohmic or collisionless heating is much larger when the discharge is excited by a superposition of currents at two frequencies than if either current had acted alone. This coupling effect occurs because the lower frequency current, while not directly heating the electrons to any great extent, strongly affects the spatial structure of the discharge in the sheath regions

Electron surface layer at the interface of a plasma and a dielectric wall

We study the potential and the charge distribution across the interface of a plasma and a dielectric wall. For this purpose, the charge bound to the wall is modelled as a quasi-stationary electron surface layer which satisfies Poisson's equation and minimizes the grand canonical potential of the wall-thermalized excess electrons constituting the wall charge. Based on an effective model for a graded interface taking into account the image potential and the offset of the conduction band to the potential just outside the dielectric, we specifically calculate the potential and the electron distribution for magnesium oxide, silicon dioxide and sapphire surfaces in contact with a helium discharge. Depending on the electron affinity of the surface, we find two vastly different behaviors. For negative electron affinity, electrons do not penetrate into the wall and an external surface charge is formed in the image potential, while for positive electron affinity, electrons penetrate into the wall and a space charge layer develops in the interior of the dielectric. We also investigate how the electron surface layer merges with the bulk of the dielectric.Comment: 15 pages, 9 figures, accepted versio