1,227 research outputs found

    A Malaria Ecology Index Predicted Spatial and Temporal Variation of Malaria Burden and Efficacy of Antimalarial Interventions Based on African Serological Data.

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    Reducing the global health burden of malaria is complicated by weak reporting systems for infectious diseases and a paucity of vital statistics registration. This limits our ability to predict changes in malaria health burden intensity, target antimalarial resources where needed, and identify malaria impacts in retrospective data. We refined and deployed a temporally and spatially varying Malaria Ecology Index (MEI) incorporating climatological and ecological data to estimate malaria transmission strength and validate it against cross-sectional serology data from 39,875 children from seven sub-Saharan African countries. The MEI is strongly associated with malaria burden; a 1 standard deviation higher MEI is associated with a 50-117% increase in malaria risk and a 3-5 g/dL lower level of Hg. Results show that the relationship between malaria ecology and disease burden is attenuated with sufficient coverage of insecticide treated nets (ITNs) or indoor residual spraying (IRS). Having both ITNs and IRS reduce the added risk from adverse malaria ecology conditions by half. Readily available climate and ecology data can be used to estimate the spatial and temporal variation in malaria disease burden, providing a feasible alternative to direct surveillance. This will help target resources for malaria programs in the absence of national coverage of active case detection systems, and facilitate malaria research using retrospective health data

    Effect of canopy cover and specific leaf area on endophyte diversity in Rhododendron macrophyllum and Acer macrophyllum

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    Nearly all plants share an asymptomatic symbiosis with many different kinds of endophytes: fungi and bacteria that exist within the plants. Despite their pervasiveness, much remains a mystery surrounding why these relationships exist. It is known that in certain circumstances the endophytes provide pathogen resistance for host plants. The purpose of this study was to identify certain factors that affect endophyte diversity. We chose to measure specific leaf area and canopy cover while collecting leaves from Rhododendron macrophyllum and Acer macrophyllum. These were chosen to represent low and high SLA. We predicted that leaves with low SLA will have fewer morphospecies due to more investment in leaf structure, thus having more built-in defenses. Sections of these leaves were plated on a mycelium medium to watch for growth. Endophytes were morphotyped by size, shape, and color. As predicted, Maple leaves showed 23% greater endophyte richness than Rhododendrons. Assuming a beneficial symbiotic relationship, it might be the possible that certain plants with a greater investment in leaf structure are not as reliant on endophyte protection. Canopy cover was not shown to have a significant affect on endophyte diversity and it was the same across leaf-types. To further address this issue, more plants would be needed to get a broader spectrum of SLA values. Further studies should aim at identifying if the endophytes are providing their hosts benefits and what those might be

    Sweden\u27s Great Escape: Industrialization and The Changing Productivity Cost of Winter

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    We combine a paleoclimate reconstruction of the North Atlantic Oscillation (NAO)- a key determinant of Scandinavian winter intensity- with four centuries of historical production data from Sweden, to examine the changing influence of climate variability on production over time. We find the colder, drier winters associated with the negative phase of the NAO led to reduced economic production for much of Swedish history, and that this relationship changed with development: during industrialization, Sweden underwent a transition from ‘level’ effects, where harsh winters lowered average incomes, to ‘growth’ effects, where it reduced growth in improving living standards. Post-industrialization, neither ‘level’ nor ‘growth’ effects remain. We use sectoral production data to show that the growth effects uncovered in the industrialization period are strongest in the sectors of the economy most exposed to the climate and of greatest importance to the industrialization process, namely, transport, manufacturing and construction

    Transitioning to accrual accounting in the public sector

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    Public sector entities’ aim is to provide services to their citizens. They operate in a specific environment and thus, their accounting system differs from the one used by business enterprises, and its development moves towards greater achievement of the international financial communication, in terms of comparing financial statements between various governments. The purpose of this research paper is to give insight into the current state and the perspectives for further development of the public sector’s accounting system over the implementation of the accrual-based accounting in order to reach further harmonization and unification of financial reporting and thus comparability of public sector’s results in different countries, a much better understanding of financial statements, and taking further measures and making decisions based on results. Accrual accounting provides a comprehensive view of a government’s assets and liabilities, and of its financial performance and cash flows for the period under review. Accrual accounting standards reflect the long-term economic impact of political decisions reflected in financial statements

    Genetic Variation Between Populations of Plethodon hubrichti

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    Undergraduate Basi

    Debris Disks in the Scorpius-Centaurus OB Association Resolved by ALMA

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    We present a CO(2-1) and 1240 um continuum survey of 23 debris disks with spectral types B9-G1, observed at an angular resolution of 0.5-1 arcsec with the Atacama Large Millimeter/Submillimeter Array (ALMA). The sample was selected for large infrared excess and age ~10 Myr, to characterize the prevalence of molecular gas emission in young debris disks. We identify three CO-rich debris disks, plus two additional tentative (3-sigma) CO detections. Twenty disks were detected in the continuum at the >3-sigma level. For the 12 disks in the sample that are spatially resolved by our observations, we perform an independent analysis of the interferometric continuum visibilities to constrain the basic dust disk geometry, as well as a simultaneous analysis of the visibilities and broad-band spectral energy distribution to constrain the characteristic grain size and disk mass. The gas-rich debris disks exhibit preferentially larger outer radii in their dust disks, and a higher prevalence of characteristic grain sizes smaller than the blowout size. The gas-rich disks do not exhibit preferentially larger dust masses, contrary to expectations for a scenario in which a higher cometary destruction rate would be expected to result in a larger mass of both CO and dust. The three debris disks in our sample with strong CO detections are all around A stars: the conditions in disks around intermediate-mass stars appear to be the most conducive to the survival or formation of CO.Comment: 16 pages, 6 figures, accepted for publication in Ap

    Ice Dynamics Preceding Catastrophic Disintegration of the Floating Part of Jakobshavn Isbrie, Greenland

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    The floating terminal of Jakobshavn Isbr ae, the fastest Greenland ice stream, has disintegrated since 2002, resulting in a doubling of ice velocity and rapidly lowering inland ice elevations. Conditions prior to disintegration were modeled using control theory in a plane-stress solution, and the Missoula model of ice-shelf flow. Both approaches pointed to a mechanism that inhibits ice flow and that is not captured by either approach. Jamming of flow, an inherent property of granular materials passing through a constriction (Jakobshavn Isfjord), is postulated as the mechanism. Rapid disintegration of heavily crevassed floating ice accompanies break-up of the ice jam

    Ice Dynamics Preceding Catastrophic Disintegration of the Floating Part of Jakobshavn Isbræ, Greenland

    Get PDF
    The floating terminal of Jakobshavn Isbræ, the fastest Greenland ice stream, has disintegrated since 2002, resulting in a doubling of ice velocity and rapidly lowering inland ice elevations. Conditions prior to disintegration were modeled using control theory in a plane-stress solution, and the Missoula model of ice-shelf flow. Both approaches pointed to a mechanism that inhibits ice flow and that is not captured by either approach. Jamming of flow, an inherent property of granular materials passing through a constriction (Jakobshavn Isfjord), is postulated as the mechanism. Rapid disintegration of heavily crevassed floating ice accompanies break-up of the ice jam
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