3 resultados para Northern world
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
Background: The pig-tailed macaques are the only Old World monkeys known to be susceptible to human immunodeficiency virus type 1 (HIV-1) infection. We have previously reported that the TRIM5-Cyclophilin A (TRIMCyp) fusion in pig-tailed macaques (Macaca n
Resumo:
Using a radiolarian-based transfer function, mean annual sea surface temperature (SST) and seasonal temperature range are reconstructed through the last 10,500yrs in the northern Okinawa Trough. Down-core SST estimates reveal that throughout the Holocene the changes of mean annual SST display a three-step trend: (i) an early Holocene continuous warming between 10,500 and 8500yr BP which ends up with a abrupt cooling at about 8200yr BP; (ii) a relatively stable middle Holocene with high SST that lasted until 3200yr BP; and (iii) a late-Holocene distinct SST decline between 3200 and 500yr BP. This pattern is in agreement with the ice core and terrestrial paleoclimatic records in the Chinese continent and other regions of the world. Five cooling events with abrupt mean annual SST drops, which occur at similar to 300-600, 1400, 3100, 4600-5100 and 8200yr BP, are recognized during the last 10,500yrs. Comparison of our results with records of GISP2 ice core and marine sediment in North Atlantic region suggests these cooling events are strongly coupled, which implies a possible significant climatic correlation between high- and low-latitude areas. (C) 2007 Elsevier Ltd and INQUA. All rights reserved.
Resumo:
We monitored UVA, UVB, and solar radiation from August 2001 to 2003 on the northern Qinghai-Tibetan Plateau to characterize the diurnal and seasonal variations of UV radiation on the world's highest plateau. Daily UVB radiation and the ratio of UVB to total solar radiation increased significantly when the atmospheric ozone concentration decreased as estimated by the total ozone mapping spectrometer (TOMS), as well as when cloud coverage decreased. The UVB/UVA ratio also showed a significant increase when the TOMS ozone concentration decreased in the morning. The seasonal variation pattern of UVB, however, was closely correlated with solar elevation but was little affected by the seasonal pattern of the atmospheric ozone amount. Compared to observations from the central plateau, the magnitude of the UVB increase attributed to ozone depletion was smaller at the northern edge. The study suggests that the temporal variation of ground UV radiation is determined by both solar elevation and the ozone amount, but the spatial difference on the plateau is likely to be ascribed mainly to the spatial variation of the ozone amount. (c) 2007 Published by Elsevier B.V.