52,869 research outputs found
Ghanaâs National Health Insurance Scheme in the Context of the Health MDGs â An Empirical Evaluation Using Propensity Score Matching
In 2003 the Government of Ghana established a National Health Insurance Scheme (NHIS) to improve health care access for Ghanaians and eventually replace the cashand- carry system. This study evaluates the NHIS to determine whether it is fulfi lling its purpose in the context of the Millennium Development Goals #4 and #5 which deal with the health of women and children. We use Propensity Score Matching techniques to balance the relevant background characteristics in our survey data and compare health outcomes of recent mothers who are enrolled in the NHIS with those who are not. Our fi ndings suggest that NHIS women are more likely to receive prenatal care, deliver at a hospital, have their deliveries attended by trained health professionals, and experience less birth complications. We conclude that NHIS is an eff ective tool for increasing health care access, and improving health outcomes.Health insurance, prenatal care, Millennium Development Goals, Propensity Score Matching
Explicit correlation and intermolecular interactions: Investigating carbon dioxide complexes with the CCSD(T)-F12 method
We have optimized the lowest energy structures and calculated interaction energies for the COââAr, COââNâ, COââCO, COââHâO, and COââNHâ dimers with the recently developed explicitly correlated coupled cluster singles doubles and perturbative triples [CCSD(T)]-F12 methods and the associated VXZ-F12 (where X = D,T,Q) basis sets. For a given cardinal number, we find that results obtained with the CCSD(T)-F12 methods are much closer to the CCSD(T) complete basis set limit than the conventional CCSD(T) results. The relatively modest increase in the computational cost between explicit and conventional CCSD(T) is more than compensated for by the impressive accuracy of the CCSD(T)-F12 method. We recommend use of the CCSD(T)-F12 methods in combination with the VXZ-F12 basis sets for the accurate determination of equilibrium geometries and interaction energies of weakly bound electron donor acceptor complexes
Quantifying cooperative intermolecular interactions for improved carbon dioxide capture materials
We have optimized the geometry and calculated interaction energies for over 100 different complexes of COâ with various combinations of electron accepting (Lewis acid) and electron donating (Lewis base) molecules. We have used the recently developed explicitly correlated coupled cluster singles doubles and perturbative triples [CCSD(T)-F12] methods and the associated VXZ-F12 (where X = D,T,Q) basis sets. We observe only modest changes in the geometric parameters of COâ upon complexation, which suggests that the geometry of COâ adsorbed in a nanoporous material should be similar to that of COâ in gas phase. When COâ forms a complex with two Lewis acids via the two electron rich terminal oxygen atoms, the interaction energy is less than twice what would be expected for the same complex involving a single Lewis acid. We consider a series of complexes that exhibit simultaneous COâ-Lewis acid and COâ-Lewis base intermolecular interactions, with total interaction energies spanning 14.1â105.9 kJ molâ»Âč. For these cooperative complexes, we find that the total interaction energy is greater than the sum of the interaction energies of the constituent complexes. Furthermore, the intermolecular distances of the cooperative complexes are contracted as compared to the constituent complexes. We suggest that metal-organic-framework or similar nanoporous materials could be designed with adsorption sites specifically tailored for COâ to allow cooperative intermolecular interactions, facilitating enhanced COâ adsorption
Financing the U.S. Health System: Issues and Options for Change
Explores key issues of health reform and options for financing health care -- redirecting funds to more effective uses, rolling back tax cuts, modifying tax exclusions for health benefits, an employer play-or-pay model, and a value-added tax
The Manifestation of Stress and Rumination in Musicians
Here we offer a brief review of research on individual differences that are common to musicians, focusing on our own work on rumination and stress. Rumination and stress have been linked with depression and negative health outcomes. We discuss two of our published studies and two new, unpublished replications that find elevated levels of rumination and stress in musicians. Further, we review literature that finds this combination of rumination and stress might be especially toxic. Even though people frequently use music to help combat stress, musicians may not be taking advantage of their frequent exposure to music, further exacerbating the problem. Interventions aimed at alleviating stress and rumination might prove helpful to musicians
Attenuation of the Ganglion Cell Layer in a Premature Infant Revealed with Handheld Spectral Domain Optical Coherence Tomography
Purpose: To report on subclinical retinal abnormalities shown through handheld spectral domain optical coherence tomography on a premature infant.
Methods: Case report.
Results: The initial and follow-up exams on a premature infant revealed severely attenuated ganglion cell and nerve fiber layers. There was cystoid macular edema in both eyes at the initial visits, which resolved by the 1-year follow-up.
Discussion: Optical coherence tomography can reveal significant retinal abnormalities in premature infants which are not detectable through funduscopic exam. Documenting such findings may be useful for the comprehensive management of vision problems in children with a history of premature birth
Minimal Unitary Realizations of Exceptional U-duality Groups and Their Subgroups as Quasiconformal Groups
We study the minimal unitary representations of noncompact exceptional groups
that arise as U-duality groups in extended supergravity theories. First we give
the unitary realizations of the exceptional group E_{8(-24)} in SU*(8) as well
as SU(6,2) covariant bases. E_{8(-24)} has E_7 X SU(2) as its maximal compact
subgroup and is the U-duality group of the exceptional supergravity theory in
d=3. For the corresponding U-duality group E_{8(8)} of the maximal supergravity
theory the minimal realization was given in hep-th/0109005. The minimal unitary
realizations of all the lower rank noncompact exceptional groups can be
obtained by truncation of those of E_{8(-24)} and E_{8(8)}. By further
truncation one can obtain the minimal unitary realizations of all the groups of
the "Magic Triangle". We give explicitly the minimal unitary realizations of
the exceptional subgroups of E_{8(-24)} as well as other physically interesting
subgroups. These minimal unitary realizations correspond, in general, to the
quantization of their geometric actions as quasi-conformal groups as defined in
hep-th/0008063.Comment: 28 pages. Latex commands removed from the abstract for the arXiv. No
changes in the manuscrip
Abelian Z-theory: NLSM amplitudes and alpha'-corrections from the open string
In this paper we derive the tree-level S-matrix of the effective theory of
Goldstone bosons known as the non-linear sigma model (NLSM) from string theory.
This novel connection relies on a recent realization of tree-level
open-superstring S-matrix predictions as a double copy of super-Yang-Mills
theory with Z-theory --- the collection of putative scalar effective field
theories encoding all the alpha'-dependence of the open superstring. Here we
identify the color-ordered amplitudes of the NLSM as the low-energy limit of
abelian Z-theory. This realization also provides natural higher-derivative
corrections to the NLSM amplitudes arising from higher powers of alpha' in the
abelian Z-theory amplitudes, and through double copy also to Born-Infeld and
Volkov-Akulov theories. The Kleiss-Kuijf and Bern-Carrasco-Johansson relations
obeyed by Z-theory amplitudes thereby apply to all alpha'-corrections of the
NLSM. As such we naturally obtain a cubic-graph parameterization for the
abelian Z-theory predictions whose kinematic numerators obey the duality
between color and kinematics to all orders in alpha'.Comment: 37 pages; v2: references, explanations and arguments for
factorization added; published versio
A Search for Lost Planets in the Kepler Multi-planet Systems and the Discovery of the Long-period, Neptune-sized Exoplanet Kepler-150 f
The vast majority of the 4700 confirmed planets and planet candidates
discovered by the Kepler mission were first found by the Kepler pipeline. In
the pipeline, after a transit signal is found, all data points associated with
those transits are removed, creating a "Swiss cheese"-like light curve full of
holes, which is then used for subsequent transit searches. These holes could
render an additional planet undetectable (or "lost"). We examine a sample of
114 stars with confirmed planets to evaluate the effect of this "Swiss
cheesing". A simulation determines that the probability that a transiting
planet is lost due to the transit masking is low, but non-negligible, reaching
a plateau at lost in the period range of days. We then
model all planet transits and subtract out the transit signals for each star,
restoring the in-transit data points, and use the Kepler pipeline to search the
transit-subtracted (i.e., transit-cleaned) light curves. However, the pipeline
did not discover any credible new transit signals. This demonstrates the
validity and robustness of the Kepler pipeline's choice to use transit masking
over transit subtraction. However, a follow-up visual search through all the
transit-subtracted data, which allows for easier visual identification of new
transits, revealed the existence of a new, Neptune-sized exoplanet (Kepler-150
f) and a potential single transit of a likely false positive (Kepler-208).
Kepler-150 f ( days, R)
is confirmed with confidence using a combination of the planet
multiplicity argument, a false positive probability analysis, and a transit
duration analysis.Comment: 11 pages, 5 figures, 2 tables. Accepted into A
- âŠ