A model for emergency medicine education in post-conflict Liberia

AbstractThe specialty of emergency medicine (EM) remains largely underdeveloped in many parts of the world including Africa. Within West Africa the Liberian health care system was presented with incredible challenges in the immediate post conflict years. One significant challenge facing the country was the paucity of health care providers. In 2006, only 122 physicians were practising in Liberia (one for every 26,782 citizens), only 87 of them Liberian national physicians. The public health indicators in post conflict Liberia suffered as a result of the overburdened system. Many indicators placed Liberia as having the worst health survivability in the world. Significantly, morbidity and mortality associated with unaddressed emergent presentations remained high.This article describes a unique paradigm for addressing the deficit in human capacity for emergency health care in the Republic of Liberia. This system was designed and supported by a consortium of academic medical centres in the United States working in conjunction with a local non-governmental organisation, Health Education and Relief Through Teaching (HEARTT). Since 2007, the consortium has delivered virtually uninterrupted emergency medical care and medical education at the largest teaching hospital in Liberia. The Liberian programme objectives included supervising and directing emergency medical care, providing a model for curriculum development, building capacity for medical education, and improving systems-based EM practice. The collaboration of multiple academic institutions in bringing emergency medical services and academic EM teaching to a post-conflict setting remains a unique model for introducing the development of acute care in a developing country

Degenerate flag varieties: moment graphs and Schr\"oder numbers

We study geometric and combinatorial properties of the degenerate flag varieties of type A. These varieties are acted upon by the automorphism group of a certain representation of a type A quiver, containing a maximal torus T. Using the group action, we describe the moment graphs, encoding the zero- and one-dimensional T-orbits. We also study the smooth and singular loci of the degenerate flag varieties. We show that the Euler characteristic of the smooth locus is equal to the large Schr\"oder number and the Poincar\'e polynomial is given by a natural statistics counting the number of diagonal steps in a Schr\"oder path. As an application we obtain a new combinatorial description of the large and small Schr\"oder numbers and their q-analogues.Comment: 25 page

Anisotropic Superexchange for nearest and next nearest coppers in chain, ladder and lamellar cuprates

We present a detailed calculation of the magnetic couplings between nearest-neighbor and next-nearest-neighbor coppers in the edge-sharing geometry, ubiquitous in many cuprates. In this geometry, the interaction between nearest neighbor coppers is mediated via two oxygens, and the Cu-O-Cu angle is close to 90 degrees. The derivation is based on a perturbation expansion of a general Hubbard Hamiltonian, and produces numerical estimates for the various magnetic energies. In particular we find the dependence of the anisotropy energies on the angular deviation away from the 90 degrees geometry of the Cu-O-Cu bonds. Our results are required for the correct analysis of the magnetic structure of various chain, ladder and lamellar cuprates.Comment: 13 pages, Latex, 7 figure

Interplay of Electron-Phonon Interaction and Electron Correlation in High Temperature Superconductivity

We study the electron-phonon interaction in the strongly correlated superconducting cuprates. Two types of the electron-phonon interactions are introduced in the $t-J$ model; the diagonal and off-diagonal interactions which modify the formation energy of the Zhang-Rice singlet and its transfer integral, respectively. The characteristic phonon-momentum $(\vec q)$ and electron-momentum $(\vec k)$ dependence resulted from the off-diagonal coupling can explain a variety of experiments. The vertex correction for the electron-phonon interaction is formulated in the SU(2) slave-boson theory by taking into account the collective modes in the superconducting ground states. It is shown that the vertex correction enhances the attractive potential for the d-wave paring mediated by phonon with $\vec q=(\pi(1-\delta), 0)$ around $\delta \cong 0.3$ which corresponds to the half-breathing mode of the oxygen motion.Comment: 14 pages, 13 figure

Wavefunction of a Black Hole and the Dynamical Origin of Entropy

Recently it was proposed to explain the dynamical origin of the entropy of a black hole by identifying its dynamical degrees of freedom with states of quantum fields propagating in the black-hole's interior. The present paper contains the further development of this approach. The no-boundary proposal (analogous to the Hartle-Hawking no-boundary proposal in quantum cosmology) is put forward for defining the wave function of a black hole. This wave function is a functional on the configuration space of physical fields (including the gravitational one) on the three-dimensional space with the Einstein-Rosen bridge topology.It is shown that in the limit of small perturbations on the Kruskal background geometry the no-boundary wave function coincides with the Hartle-Hawking vacuum state. The invariant definition of inside and outside modes is proposed. The density matrix describing the internal state of a black hole is obtained by averaging over the outside modes. This density matrix is used to define the entropy of a black hole, which is to be divergent. It is argued that the quantum fluctuations of the horizon which are internally present in the proposed formalism may give the necessary cut-off and provide a black hole with the finite entropy.Comment: 39 pages, LaTeX misprint is corrected, original text is not modifie

Future and potential spending on health 2015-40: Development assistance for health, and government, prepaid private, and out-of-pocket health spending in 184 countries

Background: The amount of resources, particularly prepaid resources, available for health can affect access to health care and health outcomes. Although health spending tends to increase with economic development, tremendous variation exists among health financing systems. Estimates of future spending can be beneficial for policy makers and planners, and can identify financing gaps. In this study, we estimate future gross domestic product (GDP), all-sector government spending, and health spending disaggregated by source, and we compare expected future spending to potential future spending. Methods: We extracted GDP, government spending in 184 countries from 1980-2015, and health spend data from 1995-2014. We used a series of ensemble models to estimate future GDP, all-sector government spending, development assistance for health, and government, out-of-pocket, and prepaid private health spending through 2040. We used frontier analyses to identify patterns exhibited by the countries that dedicate the most funding to health, and used these frontiers to estimate potential health spending for each low-income or middle-income country. All estimates are inflation and purchasing power adjusted. Findings: We estimated that global spending on health will increase from US$9.21 trillion in 2014 to$24.24 trillion (uncertainty interval [UI] 20.47-29.72) in 2040. We expect per capita health spending to increase fastest in upper-middle-income countries, at 5.3% (UI 4.1-6.8) per year. This growth is driven by continued growth in GDP, government spending, and government health spending. Lower-middle income countries are expected to grow at 4.2% (3.8-4.9). High-income countries are expected to grow at 2.1% (UI 1.8-2.4) and low-income countries are expected to grow at 1.8% (1.0-2.8). Despite this growth, health spending per capita in low-income countries is expected to remain low, at $154 (UI 133-181) per capita in 2030 and$195 (157-258) per capita in 2040. Increases in national health spending to reach the level of the countries who spend the most on health, relative to their level of economic development, would mean $321 (157-258) per capita was available for health in 2040 in low-income countries. Interpretation: Health spending is associated with economic development but past trends and relationships suggest that spending will remain variable, and low in some low-resource settings. Policy change could lead to increased health spending, although for the poorest countries external support might remain essential