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1. chinaXiv:201910.00048 [pdf]

Monitoring the impact of climate change and human activities on grassland vegetation dynamics in the northeastern Qinghai-Tibet Plateau of China during 2000–2015

XIONG Qinli ; XIAO Yang; Marwa Waseem A HALMY ; Mohammed A DAKHIL; LIANG Pinghan; LIU Chenggang; ZHANG Lin; Bikram PANDEY; PAN Kaiwen; Sameh B EL KAFRAWAY; CHEN Jun
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology

Climate change and human activities can influence vegetation net primary productivity (NPP), a key component of natural ecosystems. The Qinghai-Tibet Plateau of China, in spite of its significant natural and cultural values, is one of the most susceptible regions to climate change and human disturbances in the world. To assess the impact of climate change and human activities on vegetation dynamics in the grassland ecosystems of the northeastern Qinghai-Tibet Plateau, we applied a time-series trend analysis to normalized difference vegetation index (NDVI) datasets from 2000 to 2015 and compared these spatiotemporal variations with trends in climatic variables over the same time period. The constrained ordination approach (redundancy analysis) was used to determine which climatic variables or human-related factors mostly in?uenced the variation of NDVI. Furthermore, in order to determine whether current conservation measures and programs are effective in ecological protection and reconstruction, we divided the northeastern Qinghai-Tibet Plateau into two parts: the Three-River Headwater conservation area (TRH zone) in the south and the non-conservation area (NTRH zone) in the north. The results indicated an overall (73.32%) increasing trend of vegetation NPP in grasslands throughout the study area. During the period 2000–2015, NDVI in the TRH and NTRH zones increased at the rates of 0.0015/a and 0.0020/a, respectively. Specifically, precipitation accounted for 9.2% of the total variation in NDVI, while temperature accounted for 13.4%. In addition, variation in vegetation NPP of grasslands responded not only to long- and short-term changes in climate, as conceptualized in non-equilibrium theory, but also to the impact of human activities and their associated perturbations. The redundancy analysis successfully separated the relative contributions of climate change and human activities, of which village population and agricultural gross domestic product were the two most important contributors to the NDVI changes, explaining 17.8% and 17.1% of the total variation of NDVI (with the total contribution >30.0%), respectively. The total contribution percentages of climate change and human activities to the NDVI variation were 27.5% and 34.9%, respectively, in the northeastern Qinghai-Tibet Plateau. Finally, our study shows that the grassland restoration in the study area was enhanced by protection measures and programs in the TRH zone, which explained 7.6% of the total variation in NDVI.

submitted time 2019-10-26 From cooperative journals:《Journal of Arid Land》 Hits4552Downloads523 Comment 0

2. chinaXiv:201605.01499 [pdf]

YAP Enhances Autophagic Flux to Promote Breast Cancer Cell Survival in Response to Nutrient Deprivation

Song, Qinghe; Mao, Beibei; Cheng, Jinbo; Gao, Yuhao; Yuan, Zengqiang; Song, Qinghe; Gao, Yuhao; Yuan, Zengqiang; Jiang, Ke; Meng, Songshu; Chen, Jun
Subjects: Biology >> Biophysics

The Yes-associated protein (YAP), a transcriptional coactivator inactivated by the Hippo tumor suppressor pathway, functions as an oncoprotein in a variety of cancers. However, its contribution to breast cancer remains controversial. This study investigated the role of YAP in breast cancer cells under nutrient deprivation (ND). Here, we show that YAP knockdown sensitized MCF7 breast cancer cells to nutrient deprivation-induced apoptosis. Furthermore, in response to ND, YAP increased the autolysosome degradation, thereby enhancing the cellular autophagic flux in breast cancer cells. Of note, autophagy is crucial for YAP to protect MCF7 cells from apoptosis under ND conditions. In addition, the TEA domain (TEAD) family of growth-promoting transcription factors was indispensable for YAP-mediated regulation of autophagy. Collectively, our data reveal a role for YAP in promoting breast cancer cell survival upon ND stress and uncover an unappreciated function of YAP/TEAD in the regulation of autophagy.

submitted time 2016-05-12 Hits1430Downloads870 Comment 0

3. chinaXiv:201605.01376 [pdf]

The Endoplasmic Reticulum Adaptor Protein ERAdP Initiates NK Cell Activation via the Ubc13-Mediated NF-kappa B Pathway

Chen, Jun; Hao, Lu; Li, Chong; Ye, Buqing; Du, Ying; Zhang, Honglian; Zhu, Pingping; Liu, Benyu; Yang, Liuliu; Fan, Zusen; Chen, Jun; Hao, Lu; Long, Bo; Long, Bo; Li, Peifeng; Tian, Yong
Subjects: Biology >> Biophysics >> Immunology

NK cells play a pivotal role in innate immune responses against pathogenic infections. However, the underlying mechanisms driving defined NK functions remain largely elusive. In this study, we identified a novel endoplasmic reticulum (ER) membrane protein, ER adaptor protein (ERAdP), which is constitutively expressed in human and mouse NK cells. ERAdP is expressed at low levels in peripheral NK cells of hepatitis B virus-associated hepatocellular carcinoma patients. We show that ERAdP initiates NK cell activation through the NF-kappa B pathway. Notably, ERAdP interacts with ubiquitin-conjugating enzyme 13 (Ubc13) to potentiate its charging activity. Thus, ERAdP augments Ubc13-mediated NF-kappa B essential modulator ubiquitination to trigger the Ubc13-mediated NF-kappa B pathway, leading to NK cell activation. Finally, ERAdP transgenic mice display hyperactivated NK cells that are more resistant to pathogenic infections. Therefore, understanding the mechanism of ERAdP-mediated NK cell activation will provide strategies for treatment of infectious diseases.

submitted time 2016-05-12 Hits2051Downloads1110 Comment 0

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