5,307 research outputs found
Market Forces and the Public Good: Competition Among Hospitals and Provision of Indigent Care
The research presented here focuses on the impact of competitive forces on the provision of social or merit goods by non-profit hospitals. We specifically examine the behavior of altruistic non-profit hospitals in the supply of charity care. The effects of competitive pressures and past charity care provision on the supply of philanthropic donations to nonprofit hospitals are also examined. Empirical models of the supply of donations and charity care are specified and estimated using data on nonprofit hospitals in Florida for the years 1980-1984. The coefficient estimates imply strong income effects in the charity care supply equations. This raises the possibility that competitive pressures and limits on hospital payments, under public insurance programs, may reduce the supply of indigent care. The results from the supply of donations models suggest that philanthropic donations will alleviate the competitive pressures to a small degree.
Anisoplanicity studies within NGC6871
Images corrected with adaptive optics benefit from an increase in the amount of flux contained within the diffraction-limited core. The degree of this correction is measured by the Strehl ratio, equal to the ratio of the maximum observed intensity to the maximum theoretical intensity. Natural guide star adaptive optics systems are limited by the need for a guide star of adequate magnitude within suitable proximity to the science target. Thus, the above-described benefit can only be obtained for objects over a fraction of the total sky. Two nights of imaging the central region of the open star cluster NGC6871 with the Palomar Adaptive Optics System has supplied measurements of the Strehl ratio for numerous stars within the field. These measurements were used to calculate K band isoplanatic angles of 39 arcseconds (UT 1999 May 31) and 50 arcseconds (UT 1999 August 1). These isoplanatic angles are compared to those derived from Kolmogorov atmospheric theory, and their implications for adaptive optics systems are discussed
Tendinosis develops from age- and oxygen tension-dependent modulation of Rac1 activity.
Age-related tendon degeneration (tendinosis) is characterized by a phenotypic change in which tenocytes display characteristics of fibrochondrocytes and mineralized fibrochondrocytes. As tendon degeneration has been noted in vivo in areas of decreased tendon vascularity, we hypothesized that hypoxia is responsible for the development of the tendinosis phenotype, and that these effects are more pronounced in aged tenocytes. Hypoxic (1% O2 ) culture of aged, tendinotic, and young human tenocytes resulted in a mineralized fibrochondrocyte phenotype in aged tenocytes, and a fibrochondrocyte phenotype in young and tendinotic tenocytes. Investigation of the molecular mechanism responsible for this phenotype change revealed that the fibrochondrocyte phenotype in aged tenocytes occurs with decreased Rac1 activity in response to hypoxia. In young hypoxic tenocytes, however, the fibrochondrocyte phenotype occurs with concomitant decreased Rac1 activity coupled with increased RhoA activity. Using pharmacologic and adenoviral manipulation, we confirmed that these hypoxic effects on the tenocyte phenotype are linked directly to the activity of RhoA/Rac1 GTPase in in vitro human cell culture and tendon explants. These results demonstrate that hypoxia drives tenocyte phenotypic changes, and provide a molecular insight into the development of human tendinosis that occurs with aging
Sparse-matrix wavefront reconstruction: simulations and experiments
Adaptive optics systems with Shack-Hartmann wavefront sensors require reconstruction of the atmospheric phase error from subaperture slope measurements, with every sensor in the array being used in the computation of each actuator command. This fully populated reconstruction matrix can result in a significant computational burden for adaptive optics systems with large numbers of actuators. A method for generating sparse wavefront reconstruction matrices for adaptive optics is proposed. The method exploits the relevance of nearby subaperture slope measurements for control of an individual actuator, and relies upon the limited extent of the influence function for a zonal deformable mirror. Relying only on nearby sensor information can significantly reduce the calculation time for wavefront reconstruction. In addition, a hierarchic controller is proposed to recover some of the global wavefront information. The performance of these sparse wavefront reconstruction matrices was evaluated in simulation, and tested on the Palomar Adaptive Optics System. This paper presents some initial results from the simulations and experiments
Silviculture and the red-cockaded woodpecker: Where do we go from here?
Recent standards and guidelines for the protection and management of red-cockaded woodpecker habitat within 3/4 mi of colony sites, and also thinning within colonies to reduce basal area and midstory will have a significant effect on National Forest lands. The relation of these thinnings to forest pest management will be examined as well as the area of forest involved. Current fire regulations in relation to prescribed burns and potential fuel buildup will be examined. Plans for research, including disturbances, hazard, and risk rating for southern pine beetle and landscape changes will be presented
Oxygen ion dynamics in the Earth's ring current: Van Allen probes observations
Oxygen (O+) enhancements in the inner magnetosphere are often observed during geomagnetically active times, such as geomagnetic storms. In this study, we quantitatively examine the difference in ring current dynamics with and without a substantial O+ ion population based on almost 6 years of Van Allen Probes observations. Our results have not only confirmed previous finding of the role of O+ ions to the ring current but also found that abundant O+ ions are always present during large storms when sym-H < -60 nT without exception, whilst having the pressure ratio () between O+ and proton (H+) larger than 0.8 and occasionally even larger than 1 when L < 3. Simultaneously, the pressure anisotropy decreases with decreasing sym-H and increasing L shell. The pressure anisotropy decrease during the storm main phase is likely related to the pitch angle isotropization processes. In addition, we find that increases during the storm main phase and then decreases during the storm recovery phase, suggesting faster buildup and decay of O+ pressure compared to H+ ions, which are probably associated with some species dependent source and/or energization as well as loss processes in the inner magnetosphere.Accepted manuscrip
Liver imaging reporting and data system: An expert consensus statement
The increasing incidence and high morbidity and mortality of hepatocellular carcinoma (HCC) have inspired the creation of the Liver Imaging Reporting and Data System (LI-RADS). LI-RADS aims to reduce variability in exam interpretation, improve communication, facilitate clinical therapeutic decisions, reduce omission of pertinent information, and facilitate the monitoring of outcomes. LI-RADS is a dynamic process, which is updated frequently. In this article, we describe the LI-RADS 2014 version (v2014), which marks the second update since the initial version in 2011
Effect of body mass index and alcohol consumption on liver disease: analysis of data from two prospective cohort studies
Objective To investigate whether alcohol consumption and raised body mass index (BMI) act together to increase risk of liver disease
Optical characterization of the PALM-3000 3388-actuator deformable mirror
We describe the lab characterization of the new 3,388-actuator deformable mirror (DM3388) produced by Xinetics, Inc. for the PALM-3000 adaptive optics (AO) system1 under development by Jet Propulsion Laboratory and Caltech Optical Observatories. This square grid 66-by-66 actuator mirror has the largest number of actuators of any deformable mirror currently available and will enable high-contrast imaging for direct exoplanet imaging science at the Palomar 200" diameter Hale Telescope. We present optical measurements of the powered and unpowered mirror surface, influence functions, linearity of the actuators, and creep of the actuators. We also quantify the effect of changes in humidity
Recent Cases
Laurence M. Hamric
The instant decision demonstrates the inability of the Court, on its own or with the meager guidance provided by Congress, to discern a clear standard by which to measure the propriety of union organizational activity in light of current federal labor and antitrust law. Faced with a fact pattern that did not embody an apparent anticompetitive intent, a classic conspiracy between labor and non-labor entities, or activity clearly unrelated to the legitimate union interest in achieving better wages and working conditions, the Court was forced to abandon the clear showing test of Pennington, the intimately related test of Jewel Tea\u27 and, perhaps, even the Allen Bradley doctrine.
=============================
William G. Scott
By extending federal jurisdiction to encompass all robbery and extortion potentially affecting interstate commerce, the instant decision not only reflects, but substantially contributes to, the increasing federalization of intrastate crime under the commerce clause. In light of the decision\u27s broad rationale, the case may portend virtually unlimited expansion of federal jurisdiction into the field of crime control. At the very least, the decision constitutes authority for extending the jurisdictional range of other affecting commerce statutes to encompass all conduct potentially affecting commerce. It is difficult to conceive of any criminal activity, no matter how localized, that remains beyond the scope of the instant rationale.
===========================
Mitchell M. Purvis
The instant decision, relying on one side of conflicting precedent from other circuits, does little to reconcile the divergent answers to the issue raised by the Hayden caveat: what limits, if any, on searches and seizures should be developed to replace the discredited categorizations of the mere evidence rule. The Bennett decision,considering whether an item that possessed the requisite characteristics for protection under the privilege against self-incrimination consequently was proscribed as an object of a reasonable search and seizure, began a series of opinions obscuring the focus of this issue by failing to recognize that the amendments jointly protect overlapping substantive values through procedurally distinct mechanisms.
===========================
George M. Kryder, III
The instant court attempted to resolve the tension between these interests by permitting rejection of the entire agreement only after a substantial showing that continued operations would lead to collapse of the business. The court then would require a debtor-in-possession to bargain with the incumbent employees. A better approach would be to permit rejection of only those portions of the collective bargaining agreement that the court finds onerous and burdensome, while leaving in force the remaining portions of the agreement upon which the employees have relied. Such an analysis would afford employees greater protection than merely imposing an obligation to bargain, while simultaneously allowing the debtor-in-possession to renegotiate the burdensome provisions of the old agreement.
================================
Richard Michael Pitt
The instant court recognized at the outset that the proper extraterritorial application of the securities laws was not to be found in the language of the acts. Neither did the court consider the SEC\u27s disclaimer of the applicability of registration requirements to be controlling. Rather, the court looked to case law and foreign relations policy in determining subject matter jurisdiction. The court analyzed, one at a time, the jurisdictional bases relied upon by the lower court. Considering first the defendants\u27 activities within the United States, the court noted its holding in IT v. Vencap, Ltd., that the United States was not to be a breeding ground for fraud
- …