Two atmospheric circulation systems, the mid-latitude Westerlies and the Asian summer monsoon (ASM), play key roles in northern-hemisphere climatic changes. However, the variability of the Westerlies in Asia and their relationship to the ASM remain unclear. Here, we present the longest and highest-resolution drill core from Lake Qinghai on the northeastern Tibetan Plateau (TP), which uniquely records the variability of both the Westerlies and the ASM since 32 ka, reflecting the interplay of these two systems. These records document the anti-phase relationship of the Westerlies and the ASM for both glacial-interglacial and glacial millennial timescales. During the last glaciation, the influence of the Westerlies dominated; prominent dust-rich intervals, correlated with Heinrich events, reflect intensified Westerlies linked to northern high-latitude climate. During the Holocene, the dominant ASM circulation, punctuated by weak events, indicates linkages of the ASM to orbital forcing, North Atlantic abrupt events, and perhaps solar activity changes.
Computer models suggest that the Holocene Optimum for East Asian summer monsoon precipitation occurred at different times in different regions of China. Previous studies indicate that this time-transgressive Holocene Optimum should have been experienced about 3000 yr ago in southern China. In this study we describe a section which allows us to test this timing directly. We have closely examined high-resolution eutrophic peat/mud sequences covering the past 18,000 cal yr at Dahu, Jiangxi, on the southern boundary of the mid subtropical zone in China. Late Pleistocene successions in the Dahu record indicate cooler and much wetter conditions relative to synchronous events in north-central China. Our results indicate that the Holocene Optimum occurred between ca. 10,000 and 6000 cal yr ago in southern China, consistent with the global pattern. Conditions were relatively dry and cold from 6000 to 4000 cal yr ago. Our data also support the conclusion that the last deglaciation to early Holocene in the south was much wetter, resulting in the formation of dense broad-leaved forests, which could have acted to moderate land temperature f10,000 to 6000 cal yr ago, yielding a stable early-Holocene climate. After 6000 cal yr, forest reduction led to unstable land temperatures, and possibly to a northerly shift of the subtropical high-pressure system. Whatever the mechanism, these changes resulted in decreased precipitation between 6000 and 4000 cal yr B.P. in southern China.
Interleukin- (IL-) 35 and IL-37 are newly discovered immune-suppressing cytokines. They have been described in inflammatory diseases such as collagen-induced arthritis and asthma. However, their expressions in inflammatory bowel disease (IBD) patients have not been yet explored. Our aim was to evaluate serum and inflamed mucosal levels in IBD patients. In 20 ulcerative colitis (UC) patients, 7 Crohn's disease (CD) patients, and 15 healthy subjects, cytokine levels in serum were determined using ELISA and mucosal expression studies were performed by immunohistochemistry, quantitative real-time PCR, and Western blot. The results showed that serums IL-35 and IL-37 levels were significantly decreased in UC and CD patients compared with healthy subjects. The cytokines levels correlated inversely with UC activity. IL-35 was expressed in infiltrating immune cells while IL-37 in intestinal epithelial cells as well as inflammatory cells. IBD patients had significantly higher Ebi3, p35 (two subunits of IL-35), and IL-37b gene expressions; IL-35 and IL-37 protein expressions were higher in IBD patients compared with controls. The study showed that serums IL-35 and IL-37 might be potentially novel biomarkers for IBD. Intestinal IL-35 and IL-37 proteins are upregulated, suggesting that regulating the expression of the two cytokines may provide a new possible target for the treatment of IBD.
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