Climate Change and Drought Events in the Geochemical Records of the Lacustrine Deposits in the Southeastern Tibetan Plateau

Abstract

Lacustrine deposits at the margin of the southeastern Tibetan Plateau (SETP) are sensitive indicators for the evolution of the southwest Asian monsoon (SWAM) during the Quaternary. Thus, they can provide insight into the Quaternary climatic history and their relationship with global climatic changes. The results of the geochemical analysis of the Xiaozhongdian Basin section at the SETP suggest that SiO2 had the highest content of the major elements followed by Al2O3. The order of the abundance of the major elements was generally as follows: SiO2>Al2O3>Fe2O3>CaO>MgO>K2O>TiO2>Na2O>MnO2. The geochemical proxies, such as chemical index of alteration (CIA), the index of compositional variability (ICV) and (CaO+K2O+Na2O)/Al2O3, indicate the weak chemical weathering and the aridification of the margin of the SETP during the Heinrich events. In addition, the aridification of the SETP during the Heinrich events may be closely related to the cold signals transmitted from the high latitudes of the North Atlantic to the TP, and the effect caused the cooling effect to be very strong on the TP as a result of the upper-level westerly jet stream and then reduced the suction action associated with the SWAM, thus accelerating the drying rate of Xiaozhongdian Basin, which was amplifying the degree of drought in Heinrich events.

Insulin Promotes the Proliferation of Human Umbilical Cord Matrix-Derived Mesenchymal Stem Cells by Activating the Akt-Cyclin D1 Axis

“…Consistent with previous studies showing that insulin has pro-proliferative effects on various cell types [ 12 , 14 , 22 ], we demonstrated that insulin at concentrations higher than 2.5 μ M dose-dependently increased the number of UCM-MSC in SFM via promoting their proliferation ( Figure 1(a) ). However, it should be noted that, despite obtaining similar results in UCM-MSC, several investigators reported that insulin at merely nanomolar concentrations significantly increases the proliferation rate of human astrocytes and hepatocytes within 72 h [ 23 , 24 ], which is inconsistent with our data showing that physiologically relevant concentrations of insulin (0.1–1.0 μ M) had no significant effect on UCM-MSC proliferation.…”

Pathogenesis and Immune Response of Ebinur Lake Virus: A Newly Identified Orthobunyavirus That Exhibited Strong Virulence in Mice

“…The stained sections were evaluated for EBIV immunoreactivity by Image-Pro Plus 6.0 software (Media Cybernetics, Inc., Silver Spring, MD, United States), and the accumulated optical density (IOD) and the corresponding brown-yellow positive area were provided with three randomly selected fields of view (200×). Finally, each group was represented by the accumulated optical density IOD (SUM; Zhang et al, 2016 ; Liu et al, 2019 ). All the above were performed at Wuhan Biotechnology Corporation.…”

Spatial–temporal characteristics of drought and flood disasters in Yunnan Province on the margin of the Tibetan Plateau over the past 620 years

“…Yunnan covers a total area of 394,000 km 2 , and it has the type of complex and diverse landscape, and the mountainous area accounts for more than 87%. On account of influences of Indian monsoon, East Asian monsoon, westerly wind and the Tibet Plateau, it has abundant precipitation with an average annual rainfall of 1280 mm, unbalanced distribution of precipitation in season and region, the rainy season (May to October) accounts for over 80% (Zhang et al, 2016). The vegetation is mainly composed of a subtropical evergreen broadleaved forest, a subalpine coniferous forest, a tropical rainforest and a tropical seasonal rainforest (Niu et al, 2020).…”