Organic and inorganic sedimentary parameters in and off the Changjiang Estuary have been analyzed to reconstruct historical trends in eutrophication and hypoxia over the last century. The lipid biomarker concentration...
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Organic and inorganic sedimentary parameters in and off the Changjiang Estuary have been analyzed to reconstruct historical trends in eutrophication and hypoxia over the last century. The lipid biomarker concentrations in the Changjiang Estuary mud area,(CEMA) indicated eutrophication accelerated after the 1970s. Meanwhile, Mo/Al indicated hypoxia has increased since 1960s. Eutrophication and hypoxia in the CEMA are primarily a result of the dramatically increased load of terrestrial nutrients from the Changjiang to the East China Sea. The lipid biomarker concentrations in the southwest Cheju Island mud area (SCIMA) showed primary production is controlled mainly by changes in regional climate and marine current. No significant hypoxia occurred in the SCIMA over the past century as indicated by Mo/Al. Therefore, geochemical indicators of eutrophication and hypoxia revealed different patterns between the CEMA and SCIMA, suggesting the role of river-derived nutrients in sustaining eutrophication and hypoxia in the CEMA since the 1960s. (C) 2015 Elsevier Ltd. All rights reserved.
作者：
zhao GuangwuJiang xuwenZhejiang Agr & Forestry Univ
Coll Agr & Food Sci Key Lab Qual Improvement Agr Prod Zhejiang Prov Linan Zhejiang Peoples R China Qingdao Agr Univ
Coll Agron & Plant Protect Shangdong Prov Key Lab Dryland Technol Qingdao Shandong Peoples R China
Masson pine (Pinus massoniana Lamb.) is an important timber species and is widely planted in southern China. A large quantity of seed is required for sowing each year. However, low germination in the nursery has resul...
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Masson pine (Pinus massoniana Lamb.) is an important timber species and is widely planted in southern China. A large quantity of seed is required for sowing each year. However, low germination in the nursery has resulted in low seedling yields with a consequent negative impact on the Masson pine afforestation program. The purpose of our study was to determine whether gibberellin (GA(3)) or indole-3-acetic acid (IAA) would be more effective in propagating the species from seeds for afforestation and to elucidate their effects on seed respiration and endogenous hormone levels. Seeds were soaked in GA(3) and IAA solutions of different concentrations at 25 degrees C in the dark for 24 hours, and a germination test was conducted. Seed respiration was measured indirectly by estimating oxygen consumption in a closed system. Endogenous hormone levels were analyzed by gas chromatography/mass spectrometry (GC/MS). The germination test showed that the most significant promotion of seed germination and seedling vigor occurred at 5 x 10(-5) M GA(3) in both varieties and that the effects of IAA were variety dependent. Oxygen-sensing measurements showed that increased metabolism time, critical oxygen pressure, and relative germination time were decreased and the oxygen metabolism rate was increased in IAA-and GA3-treated seeds. GC/MS analysis showed that the application of 5 x 10(-5) M GA(3) decreased the endogenous abscisic acid (ABA) content, but increased IAA and GA(1), levels. Our experiment suggests that exogenous GA(3) improves seed germination and seedling vigor of Masson pine through promoting seed respiration or lowering the ABA level and stimulating IAA and GA(1), biosynthesis.
Mammalian target of rapamycin complex 1 (mTORC1) is a key regulator of cell growth and metabolism. Its activity is controlled by various types of signals, including growth factors, nutrients, and stresses. In this stu...
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Mammalian target of rapamycin complex 1 (mTORC1) is a key regulator of cell growth and metabolism. Its activity is controlled by various types of signals, including growth factors, nutrients, and stresses. In this study, we show that changes in expression levels of two antiapoptotic proteins, Bcl-2 and Bcl-X-L, also affect mTORC1 signaling activity. In cells overexpressing Bcl-X-L, mTORC1 activity is increased and becomes less sensitive to growth factor or nutrient conditions. In contrast, reduction in expression levels of the two antiapoptotic proteins inhibits mTORC1 signaling activity. Our results suggest that the effect of Bcl-2 and Bcl-X-L on mTORC1 is mediated by FKBP38, an inhibitor of mTORC1. The two proteins compete with mTORC1 for FKBP38 binding and hence alter mTORC1 activity. This study reveals a novel cross-talk between Bcl-2/X-L and mTORC1 signaling, which is likely to contribute to cancer development.
An efficient, convenient, and environmentally benign protocol for preparation of various polysubstituted pyridines under mild reaction conditions is described.
An efficient, convenient, and environmentally benign protocol for preparation of various polysubstituted pyridines under mild reaction conditions is described.
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