How Much Uncompensated Care do Doctors Provide?

The magnitude of provider uncompensated care has become an important public policy issue. Yet existing measures of uncompensated care are flawed because they compare uninsured payments to list prices, not to the prices actually paid by the insured. We address this issue using a novel source of data from a vendor that processes financial data for almost 4000 physicians. We measure uncompensated care as the net amount that physicians lose by lower payments from the uninsured than from the insured. Our best estimate is that physicians provide negative uncompensated care to the uninsured, earning more on uninsured patients than on insured patients with comparable treatments. Even our most conservative estimates suggest that uncompensated care amounts to only 0.8% of revenues, or at most $3.2 billion nationally. These results highlight the important distinction between charges and payments, and point to the need for a re-definition of uncompensated care in the health sector going forward.

Maximum Likelihood for Matrices with Rank Constraints

Maximum likelihood estimation is a fundamental optimization problem in statistics. We study this problem on manifolds of matrices with bounded rank. These represent mixtures of distributions of two independent discrete random variables. We determine the maximum likelihood degree for a range of determinantal varieties, and we apply numerical algebraic geometry to compute all critical points of their likelihood functions. This led to the discovery of maximum likelihood duality between matrices of complementary ranks, a result proved subsequently by Draisma and Rodriguez.Comment: 22 pages, 1 figur

Verifying the no-hair property of massive compact objects with intermediate-mass-ratio inspirals in advanced gravitational-wave detectors

The detection of gravitational waves from the inspiral of a neutron star or stellar-mass black hole into an intermediate-mass black hole (IMBH) promises an entirely new look at strong-field gravitational physics. Gravitational waves from these intermediate-mass-ratio inspirals (IMRIs), systems with mass ratios from ~10:1 to ~100:1, may be detectable at rates of up to a few tens per year by Advanced LIGO/Virgo and will encode a signature of the central body's spacetime. Direct observation of the spacetime will allow us to use the "no-hair" theorem of general relativity to determine if the IMBH is a Kerr black hole (or some more exotic object, e.g. a boson star). Using modified post-Newtonian (pN) waveforms, we explore the prospects for constraining the central body's mass-quadrupole moment in the advanced-detector era. We use the Fisher information matrix to estimate the accuracy with which the parameters of the central body can be measured. We find that for favorable mass and spin combinations, the quadrupole moment of a non-Kerr central body can be measured to within a ~15% fractional error or better using 3.5 pN order waveforms; on the other hand, we find the accuracy decreases to ~100% fractional error using 2 pN waveforms, except for a narrow band of values of the best-fit non-Kerr quadrupole moment.Comment: Second version, 12 pages, 5 figures, accepted by PR

Evaluation of phosphorus, calcium, and magnesium content in commercially available foods formulated for healthy cats.

BackgroundHigh dietary phosphorus (P) and low calcium-to-phosphorus ratio (Ca:P) are associated with kidney damage in cats. There are no established guidelines for dietary P maximum for cats.ObjectivesTo quantify crude protein, P, Ca, and magnesium (Mg) concentrations in cat foods and compare among food formats (dry, canned, raw), primary protein ingredients, protein concentrations (low, moderate, high), grain-free versus grain-containing foods, foods intended for adult maintenance versus all life stages, and cost.SamplesEighty-two commercial nonprescription cat foods.MethodsDescriptive study. Mineral concentrations were measured using inductively coupled argon plasma-optical emission spectroscopy. Crude protein was measured using the Dumas nitrogen combustion method. Mineral and crude protein concentrations were compared among food categories.ResultsTwenty-seven foods contained ≥3.6 g P/1000 kcal metabolizable energy (ME), of which 7 exceeded 4.8 g/1000 kcal ME. Thirteen foods had low Ca:P ratio (≤1.0). The low-protein diet group had no products ≥3.6 g P/1000 kcal ME, which was significantly different compared to the high-protein diet group (52% of products had ≥3.6 g P/1000 kcal ME; P = .01). No significant differences in P content and Ca:P ratio were found among other diet categories. Canned foods had significantly lower Mg compared to dry (P < .001) and raw (P = .007) foods. Declared minimum P and Ca were significantly lower than analyzed concentrations (P = .0005 and P = .003, respectively).Conclusions and clinical importanceThe high number of foods with high P and low Ca suggest that pet food regulatory reform should be considered

Las cuotas de género en el municipio de La Paz, Estado de México y la construcción de sujetos políticos. Un enfoque de género. 2009-2012

Este artículo ofrece conocer el tema de las cuotas de género y cuál es el aporte para la construcción de las mujeresregidoras como sujetos políticos capaces de incidir en la política local en el municipio de La Paz, Estado deMéxico, desde un enfoque de género. También fue importante identificar los factores culturales (patriarcales),políticos (intereses) que obstaculizan o impulsan su participación política y las prácticas que las promuevencomo sujetos políticos. La metodología empleada fue cualitativa. La técnica manejada fue la entrevista semi-estructurada en donde se exploró el discurso y la subjetividad de las y los entrevistados. Los resultados describenque las cuotas de género son apenas perceptibles a nivel local, donde existe una cultura política patriarcal queno contribuye a la construcción de una ciudadanía política. Esta barrera cultural se opone a la intervención delas mujeres en los asuntos públicos por su condición de género