4,900 research outputs found

    SAGE 1 and SAM 2 measurements of 1 micron aerosol extinction in the free troposphere

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    The SAGE 1 and SAM 2 satellite sensors were designed to measure, with global coverage, the 1 micron extinction produced by the stratospheric aerosol. In the absence of high altitude cloud, similar measurements may be made for the free tropospheric aerosol. Median extinction values in the Northern Hemisphere, for altitudes between 5 and 10 km, are found to be one-half to one order of magnitude greater than values at corresponding latitudes in the Southern Hemisphere. In addition, a seasonal increase by a factor of 1.5 yields 2 is observed in both hemispheres in local spring and summer. Following major volcanic eruptions, a long-lived enhancement of the aerosol extinction is observed for altitudes above 5 km

    Experiments feeding butter-milk

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    The objects of the following feeding trials were to determine the relative values of wash water from the creamery churn, of buttermilk fed alone, and in conjunction with soaked corn, and to determine the effect of corn following a long period of feeding with a very narrow ratio. Each lot was given all the diluted milk that it would drink. The total solids of this milk amounted to 4.5 per cent, being about one-half the total solids in ordinary buttermilk, showing that the milk was reduced about one-half its value. Lot two was fed ,two pounds of shelled corn, soaked, per day and head. Lot three was fed four pounds of shelled corn, soaked, per day and head. Lot four was fed all the corn they would eat which was from six to seven pounds per day and head. The result for lot one shows that the so-called wash water is not a sustaining ration. The pigs losing a little rising one-half pound of live weight per day and head. A part of this loss can be accounted for in stomach contents

    Combined density-functional and dynamical cluster quantum Monte Carlo calculations for three-band Hubbard models for hole-doped cuprate superconductors

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    Using a combined local density functional theory (LDA-DFT) and quantum Monte Carlo (QMC) dynamic cluster approximation approach, the parameter dependence of the superconducting transition temperature Tc of several single-layer hole-doped cuprate superconductors with experimentally very different Tcmax is investigated. The parameters of two different three-band Hubbard models are obtained using the LDA and the downfolding Nth-order muffin-tin orbital technique with N=0 and 1 respectively. QMC calculations on 4-site clusters show that the d-wave transition temperature Tc depends sensitively on the parameters. While the N=1 MTO basis set which reproduces all three pdσpd\sigma bands leads to a d-wave transition, the N=0 set which merely reproduces the LDA Fermi surface and velocities does not

    Advancing the Right to Health Through Global Organizations: The Potential Role of a Framework Convention on Global Health

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    Organizations, partnerships, and alliances form the building blocks of global governance. Global health organizations thus have the potential to play a formative role in determining the extent to which people are able to realize their right to health. This article examines how major global health organizations, such as WHO, the Global Fund to Fight AIDS, TB and Malaria, UNAIDS, and GAVI approach human rights concerns, including equality, accountability, and inclusive participation. We argue that organizational support for the right to health must transition from ad hoc and partial to permanent and comprehensive. Drawing on the literature and our knowledge of global health organizations, we offer good practices that point to ways in which such agencies can advance the right to health, covering nine areas: 1) participation and representation in governance processes; 2) leadership and organizational ethos; 3) internal policies; 4) norm-setting and promotion; 5) organizational leadership through advocacy and communication; 6) monitoring and accountability; 7) capacity building; 8) funding policies; and 9) partnerships and engagement. In each of these areas, we offer elements of a proposed Framework Convention on Global Health (FCGH), which would commit state parties to support these standards through their board membership and other interactions with these agencies. We also explain how the FCGH could incorporate these organizations into its overall financing framework, initiate a new forum where they collaborate with each other, as well as organizations in other regimes, to advance the right to health, and ensure sufficient funding for right to health capacity building. We urge major global health organizations to follow the leadership of the UN Secretary-General and UNAIDS to champion the FCGH. It is only through a rights-based approach, enshrined in a new Convention, that we can expect to achieve health for all in our lifetimes

    A boxy bulge in the Milky Way. Inversion of the stellar statistics equation with 2MASS data

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    Inverting the stellar statistics equation from 2MASS star counts, we obtain the 3D density distribution of the Galactic bulge as well as its luminosity function in the K-band. This results in a boxy bulge with axial ratios 1:0.5:0.4 and a major axis angle with respect to the Sun-galactic center of 203520^\circ-35^\circ .Comment: 5 pages, accepted to be published in A&

    Macro Implications of a Complete Transformation of U.S. Agricultural Production to Organic Farming Practices

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    A national interregional linear programming model of U.S. agriculture is used to evaluate and compare two conventional and three organic production alternatives. The objective is to estimate the effects on production, supply prices, land use, farm income, and export potential, of a complete transformation of U.S. agriculture to organic practices. Crop yields and production costs are estimated for 150 producing regions for seven crops under both conventional and organic methods. Results indicate that compared to conventional methods, widespread organic farming leads to a decrease in total production, lower export potential, higher supply prices, higher value of production, lower costs of production, and higher net farm income. U.S. domestic crop demand can be met with organic methods, but would be more expensive. Some interregional shifts in crop production would also occur

    Polaronic signature in the metallic phase of La0.7Ca0.3MnO3 films detected by scanning tunneling spectroscopy

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    In this work we map tunnel conductance curves with nanometric spatial resolution, tracking polaronic quasiparticle excitations when cooling across the insulator-to-metal transition in La0.7Ca0.3MnO3 films. In the insulating phase the spectral signature of polarons, a depletion of conductance at low bias flanked by peaks, is detected all over the scanned surface. These features are still observed at the transition and persist on cooling into the metallic phase. Polaron-binding energy maps reveal that polarons are not confined to regions embedded in a highly-conducting matrix but are present over the whole field of view both above and below the transition temperature.Comment: 10 pages, 4 figure

    Resonance-like piezoelectric electron-phonon interaction in layered structures

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    We show that mismatch of the piezoelectric parameters between layers of multiple-quantum well structures leads to modification of the electron-phonon interaction. In particular, short-wavelength phonons propagating perpendicular to the layers with wavevector close to 2πn/d2\pi n/d, where dd is the period of the structure, induce a strong smoothly-varying component of the piezo-potential. As a result, they interact efficiently with 2D electrons. It is shown, that this property leads to emission of collimated quasi-monochromatic beams of high-frequency acoustic phonons from hot electrons in multiple-quantum well structures. We argue that this effect is responsible for the recently reported monochromatic transverse phonon emission from optically excited GaAs/AlAs superlattices, and provide additional experimental evidences of this.Comment: 6 pages, 7 figure

    Elliptical-core two mode fiber sensors and devices incorporating photoinduced refractive index gratings

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    Results of experiments performed using germanium-doped, elliptical core, two-mode optical fibers whose sensitivity to strain was spatially varied through the use of chirped, refractive-index gratings permanently induced into the core using Argon-ion laser light are presented. This type of distributed sensor falls into the class of eighted-fiber sensors which, through a variety of means, weight the strain sensitivity of a fiber according to a specified spatial profile. We describe results of a weighted-fiber vibration mode filter which successfully enhances the particular vibration mode whose spatial profile corresponds to the profile of the grating chirp. We report on the high temperature survivability of such grating-based sensors and discuss the possibility of multiplexing more than one sensor within a single fiber

    Synthesis and Recognition Properties of Higher Order Tetrathiafulvalene (Ttf) Calix N Pyrroles (N=4-6)

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    Two new benzoTTF-annulated calix[n]pyrroles (n = 5 and 6) were synthesized via a one-step acid catalyzed condensation reaction and fully characterized via single crystallographic analyses. As compared to the known tetra-TTF annulated calix[4]pyrrole, which is also produced under the conditions of the condensation reaction, the expanded calix[n]pyrroles (n = 5 and 6) are characterized by a larger cavity size and a higher number of TTF units (albeit the same empirical formula). Analysis of the binding isotherms obtained from UV-Vis spectroscopic titrations carried out in CHCl3 in the presence of both anionic (Cl-, Br-, I-, CH3COO-, H2PO4-, and HSO4-) and neutral (1,3,5-trinitrobenzene (TNB) and 2,4,6-trinitrotoluene (TNT)) substrates revealed that as a general rule the calix[6]pyrrole derivative proved to be the most efficient molecular receptor for anions, while the calix[4]pyrrole congener proves most effective for the recognition of TNB and TNT. These findings are rationalized in terms of the number of electron rich TTF subunits and NH hydrogen bond donor groups within the series, as well as an ability to adopt conformations suitable for substrate recognition, and are supported by solid state structural analyses.National Science Foundation CHE 1057904, 0741973Robert A. Welch Foundation F-1018Danish Natural Science Research Council (FNU) 272-08-0047, 11-106744WCU (World Class University) program of Korea R32-2010-10217-0Villum FoundationChemistr
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