7 research outputs found

    First record of a chalicothere from the Miocene of Myanmar

    No full text
    Here we describe the first record of a chalicothere from the Miocene of Myanmar. The chalicothere, documented by a partial mandible, was unearthed from the lower portion of the Irrawaddy Formation in the region of Magway, Central Myanmar. The Burmese material belongs to an early late Miocene fauna which recently yielded hominoid remains attributed to Khoratpithecus. The specimen, which is attributed to a chalicotheriine, does not reliably match with any described Miocene Eurasian species of this subfamily, suggesting the possibility it belongs to a new taxon. The discovery of a chalicotheriine in the surroundings of Magway contributes to the hypothesis that closed habitats were an important component of the paleoenvironment of Khoratpithecus

    Microstructures and Stabilization Mechanisms of Nanocrystalline Iron-Chromium Alloys with Hafnium Addition

    No full text
    The low thermal stability of nanocrystalline metals severely limits their applications at high temperatures. In this study, we investigate the nanocrystalline stabilization mechanisms for Fe-14Cr alloys with 1, 2, and 4 at. pct Hf addition at 1173 K (900 °C). Microstructural characterizations using aberration-corrected scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy reveal high density of HfO2 nanoparticles with sizes of ~4 nm dispersed throughout the ferritic matrix. This indicates that kinetic stabilization by HfO2 nanoparticle pinning is primarily responsible for the observed high thermal stability. In addition, some Hf and Cr segregation on grain boundaries is observed in the Fe-14Cr-4Hf, suggesting the existence of thermodynamic stabilization at high Hf content. Second-phase precipitations such as hafnium carbide, M23C6, and Fe-Cr-Hf intermetallic phase are also found in the Fe-14Cr-4Hf, but their large sizes and inter-spacing suggest that their contribution to stabilization is minimal

    A review and meta-analysis of the impact of intestinal worms on child growth and nutrition

    Get PDF
    More than a half of the world's population are infected with one or more species of intestinal worms of which the nematodes Ascaris lumbricoides, Trichuris trichiura and the hookworms are the most common and important in terms of child health. This paper: (1) introduces the main species of intestinal worms with particular attention to intestinal nematodes; (2) examines how such worms may affect child growth and nutrition; (3) reviews the biological and epidemiological factors that influence the effects that worms can have on the growth and nutrition of children; (4) considers the many factors that can affect the impact of treatment with anthelmintic drugs; (5) presents the results of a meta-analysis of studies of the effect of treating worm infections on child growth and nutrition; (6) discusses the results in terms of what is reasonable to expect that deworming alone can achieve; (7) describes some important characteristics of an ideal study of the effects of deworming; and (8) comments on the implications for programmes of recommendations concerning mass deworming
    corecore