Accountable Care Organizations in California: Promise and Performance

California has more accountable care organizations (ACOs) than any other state in the country, with particularly rapid growth over the past two years. This report introduces new evidence that ACOs improve the quality of care, increase patient satisfaction, and may reduce costs

White Hats Chasing Black Hats: Careers in IT and the Skills Required to Get There

The aim of this paper is to illuminate the exciting world in which “white hat crackers” operate and to suggest topics that can help prepare students to enter this high-demand field. While currently there is extraordinary demand for graduates to fill these positions that have relatively high starting salaries, employers find it difficult to hire students right out of universities who possess the right technical and social skill sets. The education needed to execute the requisite tasks is dynamic, broad and difficult, and there is a severe lack of qualified entrants into the industry. Accordingly, we suggest twelve subject areas to which students interested in the field should be exposed. The suggested framework is the by-product of the authors’ industry experience, which includes presentations at Defcon and Blackhat. It is our hope that by describing the activities of “white hat crackers” and highlighting the basic social and technical skill sets required to be successful in this area, faculty members can become valuable partners in filling the pipeline with well-prepared graduates. We conclude the paper by suggesting that students in all business disciplines should have exposure to these topics that we consider to be an integral part of general information systems literacy

Tropical Geometry and the Motivic Nearby Fiber

We construct motivic invariants of a subvariety of an algebraic torus from its tropicalization and initial degenerations. More specifically, we introduce an invariant of a compactification of such a variety called the "tropical motivic nearby fiber." This invariant specializes in the schon case to the Hodge-Deligne polynomial of the limit mixed Hodge structure of a corresponding degeneration. We give purely combinatorial expressions for this Hodge-Deligne polynomial in the cases of schon hypersurfaces and smooth tropical varieties. We also deduce a formula for the Euler characteristic of a general fiber of the degeneration.Comment: 27 pages. Compositio Mathematica, to appea

Panel II

Each in its Ordered Place : The Spatiality of Suffering in Faulkner\u27s The Sound and the Fury / Eric Matthew Bledsoe, Florida State University Women in Motion: Escaping Yoknapatawpha / Lori Watkins Fulton, William Carey University Jamestown and Jimson Weed : Autochthnous Territory in The Sound and the Fury / Kita Douglas, University of Victori

Equivariant Sheaves

In this article we review some recent developments in heterotic compactifications. In particular we review an ``inherently toric'' description of certain sheaves, called equivariant sheaves, that has recently been discussed in the physics literature. We outline calculations that can be performed with these objects, and also outline more general phenomena in moduli spaces of sheaves.Comment: 20 pages, LaTeX, 1 figure, invited paper to appear in the special issue of the journal Chaos, Solitons, and Fractals on "Superstrings, M, F, S, ... Theory" (M.S. El Naschie and C. Castro, editors

Constraints on the Atmospheric Circulation and Variability of the Eccentric Hot Jupiter XO-3b

We report secondary eclipse photometry of the hot Jupiter XO-3b in the 4.5~$\mu$m band taken with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. We measure individual eclipse depths and center of eclipse times for a total of twelve secondary eclipses. We fit these data simultaneously with two transits observed in the same band in order to obtain a global best-fit secondary eclipse depth of $0.1580\pm 0.0036\%$ and a center of eclipse phase of $0.67004\pm 0.00013$. We assess the relative magnitude of variations in the dayside brightness of the planet by measuring the size of the residuals during ingress and egress from fitting the combined eclipse light curve with a uniform disk model and place an upper limit of 0.05$\%$. The new secondary eclipse observations extend the total baseline from one and a half years to nearly three years, allowing us to place an upper limit on the periastron precession rate of $2.9\times 10^{-3}$ degrees/day the tightest constraint to date on the periastron precession rate of a hot Jupiter. We use the new transit observations to calculate improved estimates for the system properties, including an updated orbital ephemeris. We also use the large number of secondary eclipses to obtain the most stringent limits to date on the orbit-to-orbit variability of an eccentric hot Jupiter and demonstrate the consistency of multiple-epoch Spitzer observations.Comment: 14 pages, 11 figures, published by Ap

Seeing double with K2: Testing re-inflation with two remarkably similar planets around red giant branch stars

Despite more than 20 years since the discovery of the first gas giant planet with an anomalously large radius, the mechanism for planet inflation remains unknown. Here, we report the discovery of EPIC228754001.01, an inflated gas giant planet found with the NASA K2 Mission, and a revised mass for another inflated planet, K2-97b. These planets reside on ~9 day orbits around host stars which recently evolved into red giants. We constrain the irradiation history of these planets using models constrained by asteroseismology and Keck/HIRES spectroscopy and radial velocity measurements. We measure planet radii of 1.31 +\- 0.11 Rjup and and 1.30 +\- 0.07 Rjup, respectively. These radii are typical for planets receiving the current irradiation, but not the former, zero age main sequence irradiation of these planets. This suggests that the current sizes of these planets are directly correlated to their current irradiation. Our precise constraints of the masses and radii of the stars and planets in these systems allow us to constrain the planetary heating efficiency of both systems as 0.03% +0.03%/-0.02%. These results are consistent with a planet re-inflation scenario, but suggest the efficiency of planet re-inflation may be lower than previously theorized. Finally, we discuss the agreement within 10% of stellar masses and radii, and planet masses, radii, and orbital periods of both systems and speculate that this may be due to selection bias in searching for planets around evolved stars.Comment: 18 pages, 15 figures, accepted to AJ. Figures 11, 12, and 13 are the key figures of the pape

The Mass of the White Dwarf Companion in the Self-Lensing Binary KOI-3278: Einstein vs. Newton

KOI-3278 is a self-lensing stellar binary consisting of a white-dwarf secondary orbiting a Sun-like primary star. Kruse and Agol (2014) noticed small periodic brightenings every 88.18 days in the Kepler photometry and interpreted these as the result of microlensing by a white dwarf with about 63$\%$ of the mass of the Sun. We obtained two sets of spectra for the primary that allowed us to derive three sets of spectroscopic estimates for its effective temperature, surface gravity, and metallicity for the first time. We used these values to update the Kruse and Agol (2014) Einsteinian microlensing model, resulting in a revised mass for the white dwarf of $0.539^{+0.022}_{-0.020} \, M_{\odot}$. The spectra also allowed us to determine radial velocities and derive orbital solutions, with good agreement between the two independent data sets. An independent Newtonian dynamical MCMC model of the combined velocities yielded a mass for the white dwarf of $0.5122^{+0.0057}_{-0.0058} \, M_{\odot}$. The nominal uncertainty for the Newtonian mass is about four times better than for the Einsteinian, $\pm 1.1\%$ vs. $\pm 4.1\%$ and the difference between the two mass determinations is $5.2 \%$. We then present a joint Einsteinian microlensing and Newtonian radial velocity model for KOI-3278, which yielded a mass for the white dwarf of $0.5250^{+0.0082}_{-0.0089} \, M_{\odot}$. This joint model does not rely on any white dwarf evolutionary models or assumptions on the white dwarf mass-radius relation. We discuss the benefits of a joint model of self-lensing binaries, and how future studies of these systems can provide insight into the mass-radius relation of white dwarfs.Comment: ApJ Accepted; 22 Pages, 8 Figures, 6 Tables and 4 Supplementary Table

Skeleta of affine hypersurfaces

A smooth affine hypersurface Z of complex dimension n is homotopy equivalent to an n-dimensional cell complex. Given a defining polynomial f for Z as well as a regular triangulation T\u394 of its Newton polytope \u394, we provide a purely combinatorial construction of a compact topological space S as a union of components of real dimension n, and prove that S embeds into Z as a deformation retract. In particular, Z is homotopy equivalent to S