24,711 research outputs found

    The association between county political inclination and obesity: Results from the 2012 presidential election in the United States.

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    ObjectiveWe examined whether stable, county-level, voter preferences were significantly associated with county-level obesity prevalence using data from the 2012 US Presidential election. County voting preference for the 2012 Republican Party presidential candidate was used as a proxy for voter endorsement of personal responsibility approaches to reducing population obesity risk versus approaches featuring government-sponsored, multi-sectoral efforts like those recommended by the Centers for Disease Control Centers for Disease Control (CDC, 2009).MethodCartographic visualization and spatial analysis were used to evaluate the geographic clustering of obesity prevalence rates by county, and county-level support for the Republican Party candidate in the 2012 U.S. presidential election. The spatial analysis informed the spatial econometric approach employed to model the relationship between political preferences and other covariates with obesity prevalence.ResultsAfter controlling for poverty rate, percent African American and Latino populations, educational attainment, and spatial autocorrelation in the error term, we found that higher county-level obesity prevalence rates were associated with higher levels of support for the 2012 Republican Party presidential candidate.ConclusionFuture public health efforts to understand and reduce obesity risk may benefit from increased surveillance of this and similar linkages between political preferences and health risks

    A Caratheodory theorem for the bidisk via Hilbert space methods

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    If \ph is an analytic function bounded by 1 on the bidisk \D^2 and \tau\in\tb is a point at which \ph has an angular gradient \nabla\ph(\tau) then \nabla\ph(\la) \to \nabla\ph(\tau) as \la\to\tau nontangentially in \D^2. This is an analog for the bidisk of a classical theorem of Carath\'eodory for the disk. For \ph as above, if \tau\in\tb is such that the lim inf\liminf of (1-|\ph(\la)|)/(1-\|\la\|) as \la\to\tau is finite then the directional derivative D_{-\de}\ph(\tau) exists for all appropriate directions \de\in\C^2. Moreover, one can associate with \ph and τ\tau an analytic function hh in the Pick class such that the value of the directional derivative can be expressed in terms of hh

    Facial behaviour of analytic functions on the bidisk

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    We prove that if ϕ\phi is an analytic function bounded by 1 on the bidisk and τ\tau is a point in a face of the bidisk at which ϕ\phi satisfies Caratheodory's condition then both ϕ\phi and the angular gradient ϕ\nabla\phi exist and are constant on the face. Moreover, the class of all ϕ\phi with prescribed ϕ(τ)\phi(\tau) and ϕ(τ)\nabla\phi(\tau) can be parametrized in terms of a function in the two-variable Pick class. As an application we solve an interpolation problem with nodes that lie on faces of the bidisk.Comment: 18 pages. We have replaced an erroneous proof of Theorem 5.4(1) by a valid proo

    Operator monotone functions and L\"owner functions of several variables

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    We prove generalizations of L\"owner's results on matrix monotone functions to several variables. We give a characterization of when a function of dd variables is locally monotone on dd-tuples of commuting self-adjoint nn-by-nn matrices. We prove a generalization to several variables of Nevanlinna's theorem describing analytic functions that map the upper half-plane to itself and satisfy a growth condition. We use this to characterize all rational functions of two variables that are operator monotone

    Jet transport performance in thunderstorm wind shear conditions

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    Several hours of three dimensional wind data were collected in the thunderstorm approach-to-landing environment, using an instrumented Queen Air airplane. These data were used as input to a numerical simulation of aircraft response, concentrating on fixed-stick assumptions, while the aircraft simulated an instrument landing systems approach. Output included airspeed, vertical displacement, pitch angle, and a special approach deterioration parameter. Theory and the results of approximately 1000 simulations indicated that about 20 percent of the cases contained serious wind shear conditions capable of causing a critical deterioration of the approach. In particular, the presence of high energy at the airplane's phugoid frequency was found to have a deleterious effect on approach quality. Oscillations of the horizontal wind at the phugoid frequency were found to have a more serious effect than vertical wind. A simulation of Eastern flight 66, which crashed at JFK in 1975, served to illustrate the points of the research. A concept of a real-time wind shear detector was outlined utilizing these results

    An airport wind shear detection and warning system using Doppler radar: A feasibility study

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    A feasibility study was conducted to determine whether ground based Doppler radar could measure the wind along the path of an approaching aircraft with sufficient accuracy to predict aircraft performance. Forty-three PAR approaches were conducted, with 16 examined in detail. In each, Doppler derived longitudinal winds were compared to aircraft measured winds; in approximately 75 percent of the cases, the Doppler and aircraft winds were in acceptable agreement. In the remaining cases, errors may have been due to a lack of Doppler resolution, a lack of co-location of the two sampling volumes, the presence of eddy or vortex like disturbances within the pulse volume, or the presence of point targets in antenna side lobes. It was further concluded that shrouding techniques would have reduced the side lobe problem. A ground based Doppler radar operating in the optically clear air, provides the appropriate longitudinal winds along an aircraft's intended flight path

    The composition of HB stars : RR Lyrae variables

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    We used moderately high-resolution, high S/N spectra to study the chemical composition of 10 field ab-type RR Lyrae stars. A new temperature scale was determined from literature Infrared Flux Method measures of subdwarfs and the Kurucz (1992) model atmospheres, and used to calibrate colors for both dwarfs and RR Lyraes. The applicability of Kurucz (1992) model atmospheres in the analysis of RR Lyraes at minimum light was analyzed: we found that they are able to reproduce colors, excitation and ionization equilibria as well as the wings of Halpha. We derived abundances for 21 species. The metal abundances of the program stars span the range -2.50<[Fe/H]<+0.17$. Lines of most elements are found to form in LTE conditions. Fe lines satisfy very well the excitation and ionization equilibria. RR Lyraes share the typical abundance pattern of other stars of similar [Fe/H]: alpha-elements are overabundant by about 0.4dex and Mn is underabundant by about 0.6dex in stars with [Fe/H]<-1. Significant departures from LTE are found only for a few species. We used our new [Fe/H] abundances, as well as values from Butler and coworkers (corrected to our system), and from high resolution spectroscopy of globular clusters giants, to obtain a new calibration of the DeltaS index: [Fe/H]= -0.194(\pm 0.011)DeltaS -0.08(\pm 0.18) and to update the metallicity calibration of the Ca II K line index: [Fe/H]= 0.65(\pm 0.17)W'(K) -3.49(\pm 0.39). Finally, our new metallicity scale was used to revise the [Fe/H] dependence of the absolute magnitude of RR Lyrae stars, Mv: Mv = 0.20(\pm 0.03)[Fe/H] + 1.06(\pm 0.04).Comment: 59 pages, Latex using aaspp.sty, ps-files of text, tables (21) and figures (23) available from ftp://boas3.bo.astro.it/pub/gisella To appear in October 1995 Astronomical Journa

    Counterexample Guided Abstraction Refinement Algorithm for Propositional Circumscription

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    Circumscription is a representative example of a nonmonotonic reasoning inference technique. Circumscription has often been studied for first order theories, but its propositional version has also been the subject of extensive research, having been shown equivalent to extended closed world assumption (ECWA). Moreover, entailment in propositional circumscription is a well-known example of a decision problem in the second level of the polynomial hierarchy. This paper proposes a new Boolean Satisfiability (SAT)-based algorithm for entailment in propositional circumscription that explores the relationship of propositional circumscription to minimal models. The new algorithm is inspired by ideas commonly used in SAT-based model checking, namely counterexample guided abstraction refinement. In addition, the new algorithm is refined to compute the theory closure for generalized close world assumption (GCWA). Experimental results show that the new algorithm can solve problem instances that other solutions are unable to solve
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