8,430 research outputs found
Entry and Competition in Local Hospital Markets
There has been considerable consolidation in the hospital industry in recent years. Over 900 deals occurred from 1994-2000, and many local markets, even in large urban areas, have been reduced to monopolies, duopolies or triopolies. This surge in consolidation has led to concern about its effect on competition in local markets for hospital services. In this paper we examine the impact of market structure on competition in local hospital markets – specifically, does competition increase with the number of firms? We extend the entry model developed by Bresnahan and Reiss to make use of quantity information and apply it to data on the US hospital industry. The results from the estimation are striking. In the hospital markets we examine, entry leads to markets quickly becoming competitive. Entry reduces variable profits and increases quality. Indeed, most of the effects of entry come from having a second and possibly a third firm enter the market. The use of quantity information allows us to infer that entry is welfare increasing.analysis of health care markets
Household Demand for Employer-Based Health Insurance
We use the 1996 Medical Expenditure Panel Survey to estimate a model of household demand for employer-based health insurance, explicitly investigating differences in behavior between households with two potential sources of coverage and those with one source. Own and cross-price elasticities are estimated for three types of health plans, including exclusive provider organizations, any provider organizations, and mixed provider organizations. We find that the premium, family size, income, and wealth significantly affect demand. Our elasticity estimates reveal an overall, small behavioral response to changes in price with respect to health plan switching and take-up. Finally, we discuss the implications of our findings with respect to employer benefit design.
Advanced Coordinated Beamforming for the Downlink of Future LTE Cellular Networks
Modern cellular networks in traditional frequency bands are notoriously
interference-limited especially in urban areas, where base stations are
deployed in close proximity to one another. The latest releases of Long Term
Evolution (LTE) incorporate features for coordinating downlink transmissions as
an efficient means of managing interference. Recent field trial results and
theoretical studies of the performance of joint transmission (JT) coordinated
multi-point (CoMP) schemes revealed, however, that their gains are not as high
as initially expected, despite the large coordination overhead. These schemes
are known to be very sensitive to defects in synchronization or information
exchange between coordinating bases stations as well as uncoordinated
interference. In this article, we review recent advanced coordinated
beamforming (CB) schemes as alternatives, requiring less overhead than JT CoMP
while achieving good performance in realistic conditions. By stipulating that,
in certain LTE scenarios of increasing interest, uncoordinated interference
constitutes a major factor in the performance of CoMP techniques at large, we
hereby assess the resilience of the state-of-the-art CB to uncoordinated
interference. We also describe how these techniques can leverage the latest
specifications of current cellular networks, and how they may perform when we
consider standardized feedback and coordination. This allows us to identify
some key roadblocks and research directions to address as LTE evolves towards
the future of mobile communications.Comment: 16 pages, 6 figures, accepted to IEEE Communications Magazin
Beneficial hemodynamic effects of inhibiting ANP catabolism in congestive heart failure
Pepper, Beverly (escultora)Primer pla de l'obra. També conegut com a "Cel caigut, Espiral arbrada", realitzat amb cerà mica
Un test de rémanence pour l'évaluation des moustiquaires imprégnées basé sur la vitesse du knock-down
High sensitivity variable-temperature infrared nanoscopy of conducting oxide interfaces
Probing the local transport properties of two-dimensional electron systems
(2DES) confined at buried interfaces requires a non-invasive technique with a
high spatial resolution operating in a broad temperature range. In this paper,
we investigate the scattering-type scanning near field optical microscopy as a
tool for studying the conducting LaAlO3/SrTiO3 interface from room temperature
down to 6 K. We show that the near-field optical signal, in particular its
phase component, is highly sensitive to the transport properties of the
electron system present at the interface. Our modelling reveals that such
sensitivity originates from the interaction of the AFM tip with coupled
plasmon-phonon modes with a small penetration depth. The model allows us to
quantitatively correlate changes in the optical signal with the variation of
the 2DES transport properties induced by cooling and by electrostatic gating.
To probe the spatial resolution of the technique, we image conducting
nano-channels written in insulating heterostructures with a voltage-biased tip
of an atomic force microscope.Comment: 19 pages, 5 figure
Antitumorigenic Evaluation of Thalidomide Alone and in Combination with Cisplatin in DBA2/J Mice
Thalidomide's reported ability to inhibit angiogenesis has led to clinical trials determining its effectiveness in combating various types of cancer. This study explored thalidomide's antitumorigenic potential when administered alone and in combination with cisplatin to DBA2/J mice whose tumors were induced by murine erythroleukemic cells. Thalidomide treatment alone produced no significant inhibitory effect on tumor development and metastasis. Mice that received both drugs had significantly lower incidences of both primary and secondary tumors as compared to the untreated control group. Cisplatin, administered alone or in combination with thalidomide, led to a significant delay in tumor formation and a longer life span than was recorded in untreated mice. However, the combination treatment results were not significantly different from those of cisplatin treatment used as a single agent. In in vitro cell multiplication studies using murine erythroleukemic and murine endothelial cells, thalidomide failed to inhibit cell proliferation. However, cisplatin treatment with or without thalidomide, significantly inhibited the multiplication of both cell lines in a dose dependent manner. Thalidomide does not appear to be a beneficial adjuvant to cisplatin treatment
Les salicornietum emerici et ramosissimae du littoral méditerranéen français
En este trabajo, los áutores señalan precisiones taxonómicas y corológicas sobre las Salicornias anuales del litoral mediterráneo francés. Salicornia emerie!, tetraploide y Salicornia ramosissima diploide tienen una distribución mediterránea, atlántica alcanzando Bretaña y el 5. de Inglaterra. En el Mediterráneo definen dos asociaciones territoriales, Arthocnemo-Salieornietum emerieiy Arthorocnemo-Salicornietum ramosissimae la primera en la franja interna y la segunda en la franja externa de las lagunas sobre sustrato mineral clorurado y sujeto a desecación estival
An acoustic analog to the dynamical Casimir effect in a Bose-Einstein condensate
We have realized an acoustic analog to the Dynamical Casimir effect. The
density of a trapped Bose-Einstein condensate is modulated by changing the trap
stiffness. We observe the creation of correlated excitations with equal and
opposite momenta, and show that for a well defined modulation frequency, the
frequency of the excitations is half that of the trap modulation frequency.Comment: Includes supplemental informatio
Non - linear radio frequency wave : sheath interaction in magnetized plasma edge : the role of the fast wave
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