98,547 research outputs found

    Calorimetric detection of neutral-atom content of ion beam

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    Energy deposition technique deduces neutral-beam flux or dose from measured values of incremental resistance increases in platinum wire passed through beam. Steady-state heat balance analysis led to equivalent neutral-beam current. Method was used to detect neutral-atom content of 60-keV argon ion beam

    Aids and Economic Growth: A Human Capital Approach

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    It is estimated that by 2001 20 million people had died from AIDS, which is now the world´s fourth biggest cause of death. While the highest prevalence and death rates and number of infected persons are reported for sub-Saharan Africa, where life expectancies at birth are declining rapidly and infant mortality rates are increasing, there is evidence that the epidemic is accelerating in Asia and Eastern Europe. While the human and social costs of the HIV/AIDS epidemic are the major causes for concern, the econometric results reported in this paper indicate that the macroeconomic affects of the HIV/AIDS epidemic have been substantial; especially in Africa where the average marginal negative impact on income per capita of a one percent increase in HIV prevalence rate is 0.59 percent. Even in countries where the HIV prevalence rates are lower the marginal impacts are non trivial

    The impact of HIV and AIDS on Africa's economic development

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    The macroeconomic effects of HIV/AIDS in Africa are substantial, and policies fill. dealing with them may be controversial-one is whether expensive antiretroviral drugs Should be targeted at economically productive groups of people. The authors review the evidence and consider how economic theory can contribute to our response to the pandemic

    Astrophysically robust systematics removal using variational inference: application to the first month of Kepler data

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    Space-based transit search missions such as Kepler are collecting large numbers of stellar light curves of unprecedented photometric precision and time coverage. However, before this scientific goldmine can be exploited fully, the data must be cleaned of instrumental artefacts. We present a new method to correct common-mode systematics in large ensembles of very high precision light curves. It is based on a Bayesian linear basis model and uses shrinkage priors for robustness, variational inference for speed, and a de-noising step based on empirical mode decomposition to prevent the introduction of spurious noise into the corrected light curves. After demonstrating the performance of our method on a synthetic dataset, we apply it to the first month of Kepler data. We compare the results, which are publicly available, to the output of the Kepler pipeline's pre-search data conditioning, and show that the two generally give similar results, but the light curves corrected using our approach have lower scatter, on average, on both long and short timescales. We finish by discussing some limitations of our method and outlining some avenues for further development. The trend-corrected data produced by our approach are publicly available.Comment: 15 pages, 13 figures, accepted for publication in MNRA
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