分类： 地球科学 >> 地理学 提交时间： 2023-03-19 合作期刊: 《干旱区科学》
摘要：The impact of socioeconomic development on land-use and land-cover change (LUCC) in river basins varies spatially and temporally. Exploring the spatiotemporal evolutionary trends and drivers of LUCC under regional disparities is the basis for the sustainable development and management of basins. In this study, the Weihe River Basin (WRB) in China was selected as a typical basin, and the WRB was divided into the upstream of the Weihe River Basin (UWRB), the midstream of the Weihe River Basin (MWRB), the downstream of the Weihe River Basin (DWRB), the Jinghe River Basin (JRB), and the Luohe River Basin (LRB). Based on land-use data (cultivated land, forestland, grassland, built-up land, bare land, and water body) from 1985 to 2020, we analyzed the spatiotemporal heterogeneity of LUCC in the WRB using a land-use transfer matrix and a dynamic change model. The driving forces of LUCC in the WRB in different periods were detected using the GeoDetector, and the selected influencing factors included meteorological factors (precipitation and temperature), natural factors (elevation, slope, soil, and distance to rivers), social factors (distance to national highway, distance to railway, distance to provincial highway, and distance to expressway), and human activity factors (population density and gross domestic product (GDP)). The results indicated that the types and intensities of LUCC conversions showed considerable disparities across different sub-basins, where complex conversions among cultivated land, forestland, and grassland occurred in the LRB, JRB, and UWRB, with higher dynamic change before 2000. The conversion of other land-use types to built-up land was concentrated in the UWRB, MWRB, and DWRB, with substantial increases after 2000. Additionally, the driving effects of the influencing factors on LUCC in each sub-basin also exhibited distinct diversity, with the LRB and JRB being influenced by the meteorological and social factors, and the UWRB, MWRB, and DWRB being driven by human activity factors. Moreover, the interaction of these influencing factors indicated an enhanced effect on LUCC. This study confirmed the spatiotemporal heterogeneity effects of socioeconomic status on LUCC in the WRB under regional differences, contributing to the sustainable development of the whole basin by managing sub-basins according to local conditions.
分类： 医学、药学 >> 基础医学 提交时间： 2023-05-22
Qin, Lijuan
Wang, Jiuru
Cheng, Fang
Zhang, Han
Zheng, Huaguo
Liu, Yongai
Liang, Zhentao
Wang, Baifeng
Wang, Haoyu
Ju, Ying
Tian, Huaqin
Meng, Songdong
摘要： Songdong MENG conceived of the project. Huaqin TIAN, Ying JU supervised the project. Lijuan QIN, Fang CHENG, and Jiuru WANG performed the experiments and analyzed the data. Lijuan QIN edited the original draft. Yongai LIU, Han ZHANG, Huaguo ZHENG, Baifeng WANG, Zhentao LIANG, and Haoyu WANG assisted with performing the experiments. Songdong MENG, Lijuan QIN, and Ying JU wrote the manuscript.
分类： 生物学 >> 生物物理学 >> 生物物理、生物化学与分子生物学 提交时间： 2016-05-11
Cui, Feng
Chang, Hai-Jing
Mao, Yun
Zhang, Han-Ying
Lu, Li-Xia
Yan, Shuai-Guo
Qiao, Chuan-Ling
Li, Mei-Xia
Liu, Li
Chang, Hai-Jing
Lang, Ming-Lin
Mao, Yun
Yan, Shuai-Guo
摘要： Carboxylesterases are mainly involved in the mediation of metabolic resistance of many insects to organophosphate (OP) insecticides. Carboxylesterases underwent two divergent evolutionary events: (1) quantitative mechanism characterized by the overproduction of carboxylesterase protein; and (2) qualitative mechanism caused by changes in enzymatic properties because of mutation from glycine/alanine to aspartate at the 151 site (G/A151D) or from tryptophan to leucine at the 271 site (W271L), following the numbering of Drosophila melanogaster AChE. Qualitative mechanism has been observed in few species. However, whether this carboxylesterase mutation mechanism is prevalent in insects remains unclear. In this study, wild-type, G/A151D and W271L mutant carboxylesterases from Culex pipiens and Aphis gossypii were subjected to germline transformation and then transferred to D. melanogaster. These germlines were ubiquitously expressed as induced by tub-Gal4. In carboxylesterase activity assay, the introduced mutant carboxylesterase did not enhance the overall carboxylesterase activity of flies. This result indicated that G/A151D or W271L mutation disrupted the original activities of the enzyme. Less than 1.5-fold OP resistance was only observed in flies expressing A. gossypii mutant carboxylesterases compared with those expressing A. gossypii wild-type carboxylesterase. However, transgenic flies universally showed low resistance to OP insecticides compared with non-transgenic flies. The flies expressing A. gossypii W271L mutant esterase exhibited 1.5-fold resistance to deltamethrin, a pyrethroid insecticide compared with non-transgenic flies. The present transgenic Drosophila system potentially showed that a quantitative increase in carboxylesterases induced broader resistance of insects to insecticides than a qualitative change. (C) 2014 Elsevier Inc. All rights reserved.
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