37,354 research outputs found

    Inequalities in purchase of mosquito nets and willingness to pay for insecticide-treated nets in Nigeria: Challenges for malaria control interventions

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    Objective: To explore the equity implications of insecticide-treated nets (ITN) distribution programmes that are based on user charges. Methods: A questionnaire was used to collect information on previous purchase of untreated nets and hypothetical willingness to pay (WTP) for ITNs from a random sample of householders. A second survey was conducted one month later to collect information on actual purchases of ITNs. An economic status index was used for characterizing inequity. Major findings: The lower economic status quintiles were less likely to have previously purchased untreated nets and also had a lower hypothetical and actual WTP for ITNs. Conclusion: ITN distribution programmes need to take account of the diversity in WTP for ITNs if they are to ensure equity in access to the nets. This could form part of the overall poverty reduction strategy.This study received financial support from the UNDP/World Bank/WHO Special Programme for Research and Training in Tropical diseases

    Vibrational-Rotational Spectroscopy for Planetary Atmospheres, volume 2

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    The planetary atmospheres are investigated for their chemical composition. Hydrogen, methane, ethylene, acetylene, and ethane were studied. Various spectroscopic investigations were made

    Vibrational-Rotational Spectroscopy For Planetary Atmospheres, volume 1

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    Comprehensive information on the composition and dynamics of the varied planetary atmospheres is summarized. New observations resulted in new demands for supporting laboratory studies. Spectra observed from spacecraft used to interpret planetary atmospheric structure measurements, to aid in greenhouse and cloud physics calculations, and to plan future experiments are discussed. Current findings and new ideas of physicists, chemists, and planetry astronomers relating to the knowledge of the structure of things large and small, of planets and of molecules are summarized

    Subsonic longitudinal aerodynamic characteristics of a vectored-engine-over-wing configuration having spanwise leading-edge vortex enhancement

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    A configuration which integrates a close coupled canard wing combination, spanwise blowing for enhancement of the wing leading edge vortex, an engine-over-wing concept, and a wing trailing edge coanda-effect flap is studied. The data on the configuration are presented in tabular from without discussion. The investigation was conducted in the Langley 7- by 10-foot high speed tunnel at a Mach number of 0.166 through an angle-of-attack range from -2 to 22 deg. Rectangular main engine nozzles of aspect ratio 4, 6, and 8 were tested over a momentum coefficient range from 1.0 to 1.8

    In situ analysis for intelligent control

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    We report a pilot study on in situ analysis of backscatter data for intelligent control of a scientific instrument on an Autonomous Underwater Vehicle (AUV) carried out at the Monterey Bay Aquarium Research Institute (MBARI). The objective of the study is to investigate techniques which use machine intelligence to enable event-response scenarios. Specifically we analyse a set of techniques for automated sample acquisition in the water-column using an electro-mechanical "Gulper", designed at MBARI. This is a syringe-like sampling device, carried onboard an AUV. The techniques we use in this study are clustering algorithms, intended to identify the important distinguishing characteristics of bodies of points within a data sample. We demonstrate that the complementary features of two clustering approaches can offer robust identification of interesting features in the water-column, which, in turn, can support automatic event-response control in the use of the Gulper

    Subsonic longitudinal aerodynamic characteristics and engine pressure distributions for an aircraft with an integrated scramjet designed for Mach 6 cruise

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    A 1/10-scale model of a proposed hypersonic aircraft with an integrated scramjet was tested. The investigation took place over a Mach number range from 0.2 to 0.7 and an angle of attack range from 2 deg to approximately 17 deg at a sideslip angle of 0 deg. The primary configuration variables studied were engine location, internal engine geometry, and external engine geometry. The results are presented without analysis

    Radiolysis of Macromolecular Organic Material in Mars-Relevant Mineral Matrices

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    The fate of organic material on Mars after deposition is crucial to interpreting the source of these molecules. Previous work has addressed how various organic compounds at millimeter depths in sediments respond to ultraviolet radiation. In contrast, this study addressed how highenergy particle radiation (200MeV protons, simulating the effect of galactic cosmic rays and solar wind at depths of <45 cm) inuences organic macromolecules in sediments. Specically, we report the generation of organicacid radiolysis products after exposure to radiation doses equivalent to geological time scales (17 Myr). We found that formate and oxalate were produced from a variety of organic starting materials and mineral matrices. Unlike ultravioletdriven reactions that can invoke Fenton chemistry to produce organic acids, our work suggests that irradiation of semiconductor surfaces, such as TiO2 or possible clay minerals found on Mars, forms oxygen and hydroxyl radical species, which can break down macromolecules into organic acids. We also investigated the metastability of benzoate in multiple mineral matrices. Benzoate was added to samples prior to irradiation and persisted up to 500 kGys of exposure. Our ndings suggest that organic acids are likely a major component of organic material buried at depth on Mars

    America's health care problem: an economic perspective

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    Soaring health care expenditures and the large number of uninsured Americans-now estimated at 35 million-have received much public attention in recent years. The widespread concerns have led to demands for substantial reform of the U.S. health care system. ; Beverly Fox, Lori Taylor, and Mine Yucel identify several distortions in the current health care system that may be contributing to overconsumption of health care by some and underconsumption of health care by others, and thus may be leading to excessively high expenditures and the problems of the uninsured. These distortions include tax subsidies for employer-provided health insurance, regulations and industry practices that restrict the supply of health care professionals, and the noncompetitive nature of the health insurance industry. Effective health care reform must address these distortions rather than nondistortionary elements of the system, such as producer and consumer uncertainty and the changing demographic composition of the U.S. population.Medical care
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