RESUMO
The investigation of triggers causing the onset and intensification of Northern Hemisphere Glaciation (NHG) during the late Pliocene is essential for understanding the global climate system, with important implications for projecting future climate changes. Despite their critical roles in the global climate system, influences of land-ocean interactions on high-latitude ice sheets remain largely unexplored. Here, we present a high-resolution Asian dust record from Ocean Drilling Program Site 1208 in the North Pacific, which lies along the main route of the westerlies. Our data indicate that atmosphere-land-ocean interactions affected aeolian dust emissions through modulating moisture and vegetation in dust source regions, highlighting a critical role of terrestrial systems in initiating the NHG as early as 3.6 Myr ago. Combined with additional multi-proxy and model results, we further show that westerly wind strength was enhanced, mainly at low-to-middle tropospheric levels, during major glacial events at about 3.3 and 2.7 Myr ago. We suggest that coupled responses of Earth's surface dynamics and atmospheric circulation in the Plio-Pleistocene likely involved feedbacks related to changes in paleogeography, ocean circulation, and global climate.
RESUMO
VP7 of group A rotavirus (RVA) contains major neutralizing epitopes. Using the antigenic protein VP6 as the vector, chimeric proteins carrying foreign epitopes have been shown to possess good immunoreactivity and immunogenicity. In the present study, using modified VP6 as the vector, three chimeric proteins carrying epitopes derived from VP7 of RVA were constructed. The results showed that the chimeric proteins reacted with anti-VP6 and with SA11 and Wa virus strains. Antibodies from guinea pigs inoculated with the chimeric proteins recognized VP6 and VP7 of RVA and protected mammalian cells from SA11 and Wa infection in vitro. The neutralizing activities of the antibodies against the chimeric proteins were significantly higher than those against the vector protein VP6F. Thus, development of chimeric vaccines carrying VP7 epitopes using VP6 as a vector could be a promising alternative to enhance immunization against RVAs.