| 1. |
- An, Wenling, et al.
(författare)
-
Enhanced Recent Local Moisture Recycling on the Northwestern Tibetan Plateau Deduced From Ice Core Deuterium Excess Records
- 2017
-
Ingår i: Journal of Geophysical Research - Atmospheres. - 2169-897X .- 2169-8996. ; 122:23, s. 12541-12556
-
Tidskriftsartikel (refereegranskat)abstract
- Local moisture recycling plays an essential role in maintaining an active hydrological cycle of the Tibetan Plateau (TP). Previous studies were largely limited to the seasonal time scale due to short and sparse observations, especially for the northwestern TP. In this study, we used a two-component mixing model to estimate local moisture recycling over the past decades from the deuterium excess records of two ice cores (i.e., Chongce and Zangser Kangri) from the northwestern TP. The results show that on average almost half of the precipitation on the northwestern TP is provided by local moisture recycling. In addition, the local moisture recycling ratio has increased evidently on the northwestern TP, suggesting an enhanced hydrological cycle. This recent increase could be due to the climatic and environmental changes on the TP in the past decades. Rapid increases in temperature and precipitation have enhanced evaporation. Changes of land surface of plateau have significantly increased evapotranspiration. All of these have intensified local moisture recycling. However, the mixing model used in this study only includes a limited number of climate factors. Some of the extreme values of moisture recycling ratio could be caused by large-scale atmospheric circulation and other climatic and weather events. Moreover, the potential mechanisms for the increase in local recycling need to be further examined, since the numeric simulations from climate models did not reproduce the increased contribution of local moisture recycling in precipitation.
|
|
| 2. |
- Nookaew, Intawat, 1977, et al.
(författare)
-
Transcriptome signatures in Helicobacter pylori-infected mucosa identifies acidic mammalian chitinase loss as a corpus atrophy marker
- 2013
-
Ingår i: BMC Medical Genomics. - : Springer Science and Business Media LLC. - 1755-8794. ; 6:41
-
Tidskriftsartikel (refereegranskat)abstract
- The majority of gastric cancer cases are believed to be caused by chronic infection with the bacterium Helicobacter pylori, and atrophic corpus gastritis is a predisposing condition to gastric cancer development. We aimed to increase understanding of the molecular details of atrophy by performing a global transcriptome analysis of stomach tissue. Biopsies from patients with different stages of H. pylori infection were taken from both the antrum and corpus mucosa and analyzed on microarrays. The stages included patients without current H. pylori infection, H. pylori-infected without corpus atrophy and patients with current or past H. pylori-infection with corpus-predominant atrophic gastritis. Using clustering and integrated analysis, we found firm evidence for antralization of the corpus mucosa of atrophy patients. This antralization harbored gain of gastrin expression, as well as loss of expression of corpus-related genes, such as genes associated with acid production, energy metabolism and blood clotting. The analyses provided detailed molecular evidence for simultaneous intestinal metaplasia (IM) and spasmolytic polypeptide expressing metaplasia (SPEM) in atrophic corpus tissue. Finally, acidic mammalian chitinase, a chitin-degrading enzyme produced by chief cells, was shown to be strongly down-regulated in corpus atrophy. Transcriptome analysis revealed several gene groups which are related to development of corpus atrophy, some of which were increased also in H. pylori-infected non-atrophic patients. Furthermore, loss of acidic chitinase expression is a promising marker for corpus atrophy.
|
|
