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Relationship between longitudinal changes in lipid composition and ischemic stroke among hypertensive patients
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作者 Cheng-Cheng Wei Yu-Qing Huang Cheng-Hong Yu 《World Journal of Clinical Cases》 SCIE 2025年第4期18-27,共10页
BACKGROUND Dyslipidemia was strongly linked to stroke,however the relationship between dyslipidemia and its components and ischemic stroke remained unexplained.AIM To investigate the link between longitudinal changes ... BACKGROUND Dyslipidemia was strongly linked to stroke,however the relationship between dyslipidemia and its components and ischemic stroke remained unexplained.AIM To investigate the link between longitudinal changes in lipid profiles and dyslipidemia and ischemic stroke in a hypertensive population.METHODS Between 2013 and 2014,6094 hypertension individuals were included in this,and ischemic stroke cases were documented to the end of 2018.Longitudinal changes of lipid were stratified into four groups:(1)Normal was transformed into normal group;(2)Abnormal was transformed into normal group;(3)Normal was transformed into abnormal group;and(4)Abnormal was transformed into abnormal group.To examine the link between longitudinal changes in dyslipidemia along with its components and the risk of ischemic stroke,we utilized multivariate Cox proportional hazards models with hazard ratio(HR)and 95%CI.RESULTS The average age of the participants was 62.32 years±13.00 years,with 329 women making up 54.0%of the sample.Over the course of a mean follow-up of 4.8 years,143 ischemic strokes happened.When normal was transformed into normal group was used as a reference,after full adjustments,the HR for dyslipidemia and ischemic stroke among abnormal was transformed into normal group,normal was transformed into abnormal group and abnormal was transformed into abnormal Wei CC et al.Dyslipidemia changed and ischemic stroke WJCC https://www.wjgnet.com 2 February 6,2025 Volume 13 Issue 4 group were 1.089(95%CI:0.598-1.982;P=0.779),2.369(95%CI:1.424-3.941;P<0.001)and 1.448(95%CI:1.002-2.298;P=0.047)(P for trend was 0.233),respectively.CONCLUSION In individuals with hypertension,longitudinal shifts from normal to abnormal in dyslipidemia-particularly in total and low-density lipoprotein cholesterol-were significantly associated with the risk of ischemic stroke. 展开更多
关键词 Longitudinal change HYPERTENSION DYSLIPIDEMIA Lipid profile Ischemic stroke
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Macular microvascular and structural changes on optical coherence tomography angiography in atypical optic neuritis
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作者 Chinmay Mahatme Madhurima Kaushik +2 位作者 Veerappan Rathinasabapathy Saravanan Karthik Kumar Virna M Shah 《World Journal of Methodology》 2025年第1期88-94,共7页
BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic im... BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases. 展开更多
关键词 Optical coherence tomography angiography Atypical optic neuritis Macular microvascular changes Neuromyelitis optica spectrum disorders Myelin oligodendrocyte glycoprotein antibody disorder
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Technological Progress,Structural Change and China's Energy Efficiency 被引量:2
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作者 Wang Junsong He Canfei 《Chinese Journal of Population,Resources and Environment》 2009年第2期44-49,共6页
China has witnessed rapid economic development since 1978, and during the time, energy production and consumption developed at a tremendous speed as well. Energy efficiency which can be measured by energy consumption ... China has witnessed rapid economic development since 1978, and during the time, energy production and consumption developed at a tremendous speed as well. Energy efficiency which can be measured by energy consumption per unit of GDP, however, experienced continuous decrease. Theoretically, the change of energy efficiency can be attributed to industry structural change and technological change. In order to explain the transformation of Chinese energy efficiency, we adopt logarithmic mean Divisia index techniques to decompose changes in energy intensity in the period of 1994-2005. We find that technological change is the dominant contributor in the decline of energy intensity, but the contribution has declined since 2001. The change in industry structure has decreased the energy intensity before 1998, but raised the intensity after 1998. Decomposed technological effects for all sectors indicate that technological progresses in high energy consuming industries such as raw chemical materials and chemical products, smelting and pressing of ferrous metals, manufacture of non-metallic mineral products and household contribute are the principal drivers of China's declining energy intensity. 展开更多
关键词 technological change structural change energy efficiency energy intensity
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Socio-economic and energy-environmental impacts of technological change on China's agricultural development under the carbon neutrality strategy 被引量:1
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作者 Hong-Dian Jiang Rui Yu Xiang-Yan Qian 《Petroleum Science》 SCIE EI CAS CSCD 2023年第2期1289-1299,共11页
Promoting agricultural modernisation through technological change is an important strategy for China.China's carbon neutrality strategy is leading to systemic socio-economic changes that could exacerbate the uncer... Promoting agricultural modernisation through technological change is an important strategy for China.China's carbon neutrality strategy is leading to systemic socio-economic changes that could exacerbate the uncertainty of agricultural development.Therefore,applying a computable general equilibrium(CGE)model,this study characterises the agricultural sector in detail,introducing endogenous technological change proxied by research and development(R&D)to assess the impact of different technological change scenarios on agricultural development under the carbon neutrality target.The results show that allocating carbon revenue for R&D inputs can mitigate the significant negative impact of achieving carbon neutrality on knowledge capital and production in agricultural sectors.Overall,using carbon revenue only for R&D input in crop sectors has the optimal effect on increasing the agricultural sectors'knowledge capital,improving crop production and profit,reducing crop external dependence and promoting the synergistic reduction of carbon and pollutant emissions.However,this scenario has the largest negative impact on macro-economics and household welfare.In contrast,allocating carbon revenue to promote technological change in broader non-energy sectors or both crops and non-energy sectors can effectively mitigate negative socio-economic impacts,but the positive impact on agricultural development is minimal.These findings provide practical insights for the rational use of carbon revenue to expand agricultural R&D investment and ensure balanced agricultural and economic development under the carbon neutrality target. 展开更多
关键词 Endogenous technological change R&D investment Agriculture development Computable general equilibrium
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Economic Implications of CO2 Emission Reduction in Japan Applying a Dynamic CGE Model with Endogenous Technological Change: Use of Emission Permit Revenue 被引量:1
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作者 Ken'ichi Matsumoto 《Journal of Environmental Science and Engineering(B)》 2012年第8期945-956,共12页
This study analyzes the economic and environmental impacts of a climate change measure in Japan using a single-country dynamic computable general equilibrium model with technological change as an endogenous variable. ... This study analyzes the economic and environmental impacts of a climate change measure in Japan using a single-country dynamic computable general equilibrium model with technological change as an endogenous variable. In this way, a comprehensive analysis of the relationships between climate change and its measures, technology, and economy has been done. The model uses technological change as the accumulation of knowledge capital that is derived from research and development investment. The study investigates the impacts of a climate change measure considering the use of emission permit revenue and technological change induced by the policy implementation in the Japanese economy. Simulation results show that there is compatibility between CO2 emission reduction and positive effects on GDP that depends on the ways of the revenue use and technological change induced by emission reduction. However, it is not possible to find the ways to realize positive effects on both GDP and welfare simultaneously in the study. The sensitivity analysis for the elasticity of substitution between knowledge capital and other inputs also confirms the obtained results. 展开更多
关键词 Dynamic CGE model endogenous technological change R&D investment climate change policy revenue recycling.
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Productivity Growth, Technological Progress, and Efficiency Change in Vietnamese Manufacturing Industries: A Stochastic Frontier Approach 被引量:1
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作者 Nguyen Khac Minh Pham Van Khanh +1 位作者 Nguyen Thi Minh Nguyen Thi Phuong Anh 《Open Journal of Statistics》 2012年第2期224-235,共12页
This study applies a stochastic frontier production approach to decompose the sources of total productivity (TFP) growth into technical progress and changes in technical efficiency of 8057 firms in Vietnamese manufact... This study applies a stochastic frontier production approach to decompose the sources of total productivity (TFP) growth into technical progress and changes in technical efficiency of 8057 firms in Vietnamese manufacturing industries during 2003-2007. Using both total manufacturing industry and sub-manufacturing industrial regressions, the analysis focuses on the trend of technological progress (TP) and technical efficiency change (TEC), and the role of productivity change in economic growth. According to the estimated results, the annual technical progress for the manufacturing industry and sub-manufacturing industries are calculated directly from the estimated parameters of the translog stochastic frontier production function by taking a partial derivative of output with respect to time t. The average technical changes in manufacturing industry and sub-manufacturing industries are positive, with an average technical change about 5.2%, 5.8%, 5.4%, 11.8%, 4.6%, 4.1%, 7.3%, 4.8%, 4.8% and 4.8% for total sample, food products & beverages, textile & wearing apparel, footwear, paper & products, industrial chemicals, rubber & plastic products, non- metallic mineral, basic & fabricated metal and other sub-industries, respectively. Total TFP in the manufacturing sector has grown at the annual rate of 0.052, although the rate of growth decreased continuously during the sample period. For the sub-industry estimates during the sample period, TFP grew fastest in the footwear sub-industry, with annual average growth rate of 11.8%, followed by the rubber & plastic products with a rate of 7.3%, and the food products & beverages with a rate of 5.8% per annum. 展开更多
关键词 TOTAL Factor PRODUCTIVITY TECHNICAL Efficiency change technological Progress Stochastic FRONTIER Approach VIETNAMESE Manufacturing Industry
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A RCK Model with Endogenous Fertility and Exogenous Technological Change
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作者 CAI Dong han College of Mathematics and Computer Science, Wuhan University, Wuhan 430072, China 《Wuhan University Journal of Natural Sciences》 CAS 2000年第2期137-142,共6页
The technological change as an exogenous variable is introduced into the RCK model with endogenous fertility in this paper. It is proved that the model has at least a nonzero steady state and the nonzero steady state ... The technological change as an exogenous variable is introduced into the RCK model with endogenous fertility in this paper. It is proved that the model has at least a nonzero steady state and the nonzero steady state is unique when the parameters satisfies some conditions. By phrase protrait analysis, the unique nonzero steady state is saddle and the economy has a unique optimal growth path. The results obtained implies that the relationship between the technological change and population growth rate determinated by the economic structure and the parental ethies. For the economy in which the parents is selfish, promoting the technological change rate decreases the fertility at the steady state. On the other hand, for the economy in which the parents is less selfish, the fertility increases as the technological change rate increases. 展开更多
关键词 C K model FERTILITY technological change economic growth
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Changes in Total Factor Productivity,Technological Progress and Efficiency of Banana Industry in China 被引量:2
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作者 Fang WANG Qinghe HUAN +2 位作者 Youpeng KE Jianchun GUO Qiudong LIU 《Asian Agricultural Research》 2017年第8期19-23,30,共6页
Based on the DEA-based Malmquist index method,the total factor productivity was calculated for 5 major banana production areas in 2003-2004,and it was further divided into technological progress and technical efficien... Based on the DEA-based Malmquist index method,the total factor productivity was calculated for 5 major banana production areas in 2003-2004,and it was further divided into technological progress and technical efficiency.The results show that the total factor productivity of banana industry in China was 1.3% in the sample period,mainly due to technological progress,the average growth rate was 2.6%,while the pure technical efficiency and scale efficiency was -0.1% and -1.2% respectively.The improvement of total factor productivity in banana industry in China relied mainly on technological progress,cultivation of new banana varieties,management of high quality cultivation,popularization and application of water conservation and fertilizer saving technology,and injury-free picking technologies.The pure technical efficiency and scale efficiency of banana production were negative,indicating that the management level of banana was not high.The effect of scale economy of this industry through agglomeration and consolidation is still to be practiced.Banana growers should promote the improvement of large scale and management level of the banana industry at the same time of promoting the technological progress. 展开更多
关键词 Banana industry Total factor productivity technological progress Technical efficiency
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Combating climate change calls for a global technological cooperation system built on the concept of ecological civilization 被引量:2
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作者 Jiani Jiang Wentao Wang +1 位作者 Can Wang Yanhua Liu 《Chinese Journal of Population,Resources and Environment》 2017年第1期21-31,共11页
Climate change has been considered as the most paramount global environmental problem and the biggest externality throughout the history of human development. Accordingly, the world is facing unprecedented technologic... Climate change has been considered as the most paramount global environmental problem and the biggest externality throughout the history of human development. Accordingly, the world is facing unprecedented technological innovation and collaborative demands to deal with climate change. In the 2015 Paris Agreement, a long-term vision of technology development and transfer implementation was proposed, and policy and financial support for technological innovation in the area of climate change was advocated. These terms aim to enable developing countries to acquire the necessary technology in the early stage of the technology cycle to address climate change challenge. However, the traditional technological innovation and cooperation mode based on industrial civilization can hardly meet the technical demands of global climate protection. To ensure the continuous development and deployment of technology in a required scale and pace, a new global technical cooperation system is proposed to develop based on the philosophy of ecological civilization. The core contents of this system are supposed be as follows:to implement all-win cooperation targets, adhering to cooperation principles of Eco-man, adopt cooperation content that reflects synergy, pursue cooperation based on mutual trust, encourage participation of multiple actors, and promote sharing of cooperative outputs. 展开更多
关键词 Climate change technologytransfer ecologicalcivilization INTERNATIONALCOOPERATION
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Economic Analysis of CO2 Emission Abatement Applying a Dynamic CGE Model with Endogenous Technological Change: Impacts of the Time Horizon
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作者 K. Matsumoto 《Journal of Environmental Science and Engineering》 2011年第11期1454-1463,共10页
We evaluate economic and environmental impacts of climate change mitigation in a country scale considering various time horizons in the analysis applying a single-country dynamic computable general equilibrium model w... We evaluate economic and environmental impacts of climate change mitigation in a country scale considering various time horizons in the analysis applying a single-country dynamic computable general equilibrium model with endogenous technological change. Although there is a possibility that Gross Domestic Product (GDP) becomes larger for the abatement cases than the baseline case in the earlier years, it tends to be lower than that in the later years. The longer the time horizon and/or the more severe the abatement, the larger the negative impacts will be. When subsidizing R&D investment, increase in GDP compared to the baseline case is realized in the middle of the time horizon, and the larger increase tends to be observed for the longer-term cases. These results would be due to technological change induced by the subsidies and emission abatement. Environmental indicators are also improved. We showed that the results were influenced by the target time horizon when using an intertemporal dynamic model. 展开更多
关键词 Endogenous technological change intertemporal dynamic CGE time horizon economic impact climate change policy
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Economic Impacts of Renewable Power Generation Technologies and the Role of Endogenous Technological Change 被引量:1
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作者 Christian Lutz Markus Flaute +1 位作者 Ulrike Lehr Kirsten S. Wiebe 《Open Journal of Applied Sciences》 2015年第11期696-704,共9页
This paper brings together the debate on economic impacts of renewable energy (RE) deployment and the discussion on modelling endogenous technological change on the global markets for the different renewable power gen... This paper brings together the debate on economic impacts of renewable energy (RE) deployment and the discussion on modelling endogenous technological change on the global markets for the different renewable power generation technologies. Economic impacts of RE deployment are still mostly discussed on national level, where different effects have been identified. Recent research for Germany shows positive effects on the macro level and different distributional impacts. High investment in solar photovoltaics (PV) from 2010 to 2012 and induced increases in the RE sur-charge are the main drivers. At the same time, cost reductions for wind and solar PV take place on global markets, with global learning curves explaining the cost reductions very well. This calls for better including the international dimension into the modelling. The complex feedback loops between global cost curves and national policies, which react to global learning with some time lags, are not yet integrated into complex economic models. These models have to capture different RE technologies, different industries, either delivering the RE technologies or strongly depending on electricity prices, which are influenced by national support policies and macroeconomic development. As a first step to better understand the role of international markets, assumptions on RE exports based on global scenarios can be used. Results show the importance of global markets at least for the German RE industries. If the international dimension is taken into account, mainly positive economic impacts of further RE deployment can be observed. 展开更多
关键词 RENEWABLE Power GENERATION TECHNOLOGIES ECONOMIC Impacts Global MARKETS Learning CURVES
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Technological Change as a Monetary Phenomenon
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作者 Krzysztof Wasniewski 《Economics World》 2018年第3期203-216,共14页
This article attempts to study the function of monetary systems as networks of communication,which facilitate the channelling of social effort in the presence of exogenous conditions.A model of monetary system is bein... This article attempts to study the function of monetary systems as networks of communication,which facilitate the channelling of social effort in the presence of exogenous conditions.A model of monetary system is being proposed,where monetary balances are algorithms of response,built up in the presence of uncertainty induced by technological change.Empirical research brought in support to that model demonstrates a strong and negative correlation between the velocity of money and the share of aggregate depreciation in current output,with intriguing links to exogenous mechanisms of energy absorption in the local social system. 展开更多
关键词 MONETARY SYSTEMS technological change
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Impact of the Technological and Organizational Change on the Productivity and the Structure of Skill in the Tunisians Firms
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《Journalism and Mass Communication》 2013年第4期254-267,共14页
The introduction of information and communication technologies (ICT) in the operation of businesses seems to contribute to the occurrence of important changes in the organizational practices, which, in turn, have an... The introduction of information and communication technologies (ICT) in the operation of businesses seems to contribute to the occurrence of important changes in the organizational practices, which, in turn, have an undeniable effect on the productivity and the request for qualification. Accordingly, this paper suggests an evaluation of the impact of technological and organizational innovations on the economic performances of the Tunisian firms (productivity and employment) in the period between 1997 and 2000. The technological innovations are approximated by the investments in software and hardware, and those are related to the organization of the costs of subcontracting. 展开更多
关键词 information and communication technologies (ICT) organizational change PRODUCTIVITY SKILL Tunisianfirms
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Recent advances in graphene-based phase change composites for thermal energy storage and management 被引量:2
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作者 Qiang Zhu Pin Jin Ong +4 位作者 Si Hui Angela Goh Reuben J.Yeo Suxi Wang Zhiyuan Liu Xian Jun Loh 《Nano Materials Science》 EI CAS CSCD 2024年第2期115-138,共24页
Energy storage and conservation are receiving increased attention due to rising global energy demands.Therefore,the development of energy storage materials is crucial.Thermal energy storage(TES)systems based on phase ... Energy storage and conservation are receiving increased attention due to rising global energy demands.Therefore,the development of energy storage materials is crucial.Thermal energy storage(TES)systems based on phase change materials(PCMs)have increased in prominence over the past two decades,not only because of their outstanding heat storage capacities but also their superior thermal energy regulation capability.However,issues such as leakage and low thermal conductivity limit their applicability in a variety of settings.Carbon-based materials such as graphene and its derivatives can be utilized to surmount these obstacles.This study examines the recent advancements in graphene-based phase change composites(PCCs),where graphene-based nanostructures such as graphene,graphene oxide(GO),functionalized graphene/GO,and graphene aerogel(GA)are incorporated into PCMs to substantially enhance their shape stability and thermal conductivity that could be translated to better storage capacity,durability,and temperature response,thus boosting their attractiveness for TES systems.In addition,the applications of these graphene-based PCCs in various TES disciplines,such as energy conservation in buildings,solar utilization,and battery thermal management,are discussed and summarized. 展开更多
关键词 Phase change material NANOCOMPOSITES Solar energy Sustainable energy Thermo-regulation
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Precipitation and anthropogenic activities regulate the changes of NDVI in Zhegucuo Valley on the southern Tibetan Plateau 被引量:1
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作者 ZHAO Wanglin WANG Hengying +1 位作者 ZHANG Huifang ZHANG Lin 《Journal of Mountain Science》 SCIE CSCD 2024年第2期607-618,共12页
Whether climate change or anthropogenic activities play a more pivotal role in regulating vegetation growth on the Tibetan Plateau is still controversial.A better understanding on grassland changes at a fine scale may... Whether climate change or anthropogenic activities play a more pivotal role in regulating vegetation growth on the Tibetan Plateau is still controversial.A better understanding on grassland changes at a fine scale may provide important guidance for local government policy and grassland management.Using two of the most reliable satellite NDVI products(MODIS NDVI and SPOT NDVI),we evaluated the dynamic of grasslands in the Zhegucuo valley on the southern Tibetan Plateau from 2000 to 2020,and analyzed its driving factors and relative influences of climate change and anthropogenic activities.Here,the key indicators of climate change were assumed to be precipitation and temperature.The main results were:(1)the grassland NDVI in Zhegucuo valley did not reflect a significant temporal change during the last 21 years.The variation of precipitation during the early growing season(GSP)resembled that of NDVI,and the GSP was positively correlated with NDVI.At the pixel level,the partial correlation analysis showed that 37.79%of the pixels depicted a positive relationship between GSP and NDVI,while 11.32%of the pixels showed a negative relationship between temperature during the early growing season(GST)and NDVI.(2)In view of the spatial distribution,the areas mainly controlled by GSP were generally distributed in the southern part,while those affected by GST stood in the eastern part,mainly around the Zhegucuo lake where most population in Cuomei County settled down.(3)Decreasing NDVI trends were mainly occurred in alpine steppe at lower elevations rather than alpine meadow at higher elevations.(4)The residual trend(RESTREND)analysis further indicated that the anthropogenic activities played a more pivotal role in regulating the annual changes of NDVI rather than climate factors in this area.Future studies should pay more attention on climate extremes rather than the simple temporal trends.Also,the influence of human activities on alpine grassland needs to be accessed and fully considered in future sustainable management. 展开更多
关键词 Anthropogenic activities Climate change PRECIPITATION FENCING Vegetation degradation
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Global Change in Agricultural Flash Drought over the 21st Century 被引量:1
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作者 Emily BLACK 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第2期209-220,I0002-I0019,共30页
Agricultural flash droughts are high-impact phenomena, characterized by rapid soil moisture dry down. The ensuing dry conditions can persist for weeks to months, with detrimental effects on natural ecosystems and crop... Agricultural flash droughts are high-impact phenomena, characterized by rapid soil moisture dry down. The ensuing dry conditions can persist for weeks to months, with detrimental effects on natural ecosystems and crop cultivation. Increases in the frequency of these rare events in a future warmer climate would have significant societal impact. This study uses an ensemble of 10 Coupled Model Intercomparison Project(CMIP) models to investigate the projected change in agricultural flash drought during the 21st century. Comparison across geographical regions and climatic zones indicates that individual events are preceded by anomalously low relative humidity and precipitation, with long-term trends governed by changes in temperature, relative humidity, and soil moisture. As a result of these processes, the frequency of both upperlevel and root-zone flash drought is projected to more than double in the mid-and high latitudes over the 21st century, with hot spots developing in the temperate regions of Europe, and humid regions of South America, Europe, and southern Africa. 展开更多
关键词 flash drought climate change soil moisture agricultural drought CMIP
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Shikimic acid accelerates phase change and flowering in Chinese jujube 被引量:1
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作者 Xianwei Meng Zhiguo Liu +11 位作者 Li Dai Weiqiang Zhao Jiurui Wang Lili Wang Yuanpei Cui Ying Li Yinshan Cui Yao Zhang Luyao Wang Fengjiao Yu Jin Zhao Mengjun Liu 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第2期413-424,共12页
The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely un... The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely unknown. Shikimic acid (ShA) pathway is a main metabolic pathway closely related to the synthesis of hormones and many important secondary metabolites participating in plant phase change. So,whether ShA regulates phase change in plants is worth clarifying. Here, the distinct morphological characteristics and the underlying mechanisms of phase change in jujube (Ziziphus jujuba Mill.), an important fruit tree native to China with nutritious fruit and outstanding tolerance abiotic stresses, were clarified. A combined transcriptome and metabolome analysis found that ShA is positively involved in jujube(Yuhong’×Xing 16’) phase change. The genes in the upstream of ShA synthesis pathway (ZjDAHPS, ZjDHQS and ZjSDH), the contents of ShA and the downstream secondary metabolites like phenols were significantly upregulated in the phase change period. Further, the treatment of spraying exogenous ShA verified that ShA at a very low concentration (60 mg·L^(-1)) can substantially speed up the phase change and flowering of jujube and other tested plants including Arabidopsis, tomato and wheat. The exogenous ShA (60 mg·L^(-1)) treatment in jujube seedlings could increase the accumulation of endogenous ShA, enhance leaf photosynthesis and the synthesis of phenols especially flavonoids and phenolic acids, and promote the expression of genes (ZjCOs, ZjNFYs and ZjPHYs) involved in flowering pathway. Basing on above results, we put forward a propose for the underlying mechanism of ShA regulating phase change, and a hypothesis that ShA could be considered a phytohormone-like substance because it is endogenous, ubiquitous, movable and highly efficient at very low concentrations. This study highlights the critical role of ShA in plant phase change and its phytohormone-like properties. 展开更多
关键词 Ziziphus jujuba Mill. Phase change FLOWERING Shikimic acid TRANSCRIPTOME METABOLOME
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Uphill or downhill?Cropland use change and its drivers from the perspective of slope spectrum 被引量:2
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作者 PAN Sipei LIANG Jiale +1 位作者 CHEN Wanxu PENG Yelin 《Journal of Mountain Science》 SCIE CSCD 2024年第2期484-499,共16页
The continuous decrease of low-slope cropland resources caused by construction land crowding poses huge threat to regional sustainable development and food security.Slope spectrum analysis of topographic and geomorphi... The continuous decrease of low-slope cropland resources caused by construction land crowding poses huge threat to regional sustainable development and food security.Slope spectrum analysis of topographic and geomorphic features is considered as a digital terrain analysis method which reflects the macro-topographic features by using micro-topographic factors.However,pieces of studies have extended the concept of slope spectrum in the field of geoscience to construction land to explore its expansion law,while research on the slope trend of cropland from that perspective remains rare.To address the gap,in virtue of spatial analysis and geographically weighted regression(GWR)model,the cropland use change in the Yangtze River Basin(YRB)from 2000 to 2020 was analyzed and the driving factors were explored from the perspective of slope spectrum.Results showed that the slope spectrum curves of cropland area-frequency in the YRB showed a first upward then a downward trend.The change curve of the slope spectrum of cropland in each province(municipality)exhibited various distribution patterns.Quantitative analysis of morphological parameters of cropland slope spectrum revealed that the further down the YRB,the stronger the flattening characteristics,the more obvious the concentration.The province experienced the greatest downhill cropland climbing(CLC)was Shannxi,while province experienced the highest uphill CLC was Zhejiang.The most common cropland use change type in the YRB was horizontal expansion type.The factors affecting average cropland climbing index(ACCI)were quite stable in different periods,while population density(POP)changed from negative to positive during the study period.This research is of practical significance for the rational utilization of cropland at the watershed scale. 展开更多
关键词 Cropland climbing Land use change Slope spectrum Driving factors Geographically weighted regression Yangtze River Basin
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Projected changes in extreme snowfall events over the Tibetan Plateau based on a set of RCM simulations 被引量:1
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作者 Yuanhai Fu Xuejie Gao 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第5期3-9,共7页
Extreme snowfall events over the Tibetan Plateau(TP)cause considerable damage to local society and natural ecosystems.In this study,the authors investigate the projected changes in such events over the TP and its surr... Extreme snowfall events over the Tibetan Plateau(TP)cause considerable damage to local society and natural ecosystems.In this study,the authors investigate the projected changes in such events over the TP and its surrounding areas based on an ensemble of a set of 21st century climate change projections using a regional climate model,RegCM4.The model is driven by five CMIP5 global climate models at a grid spacing of 25 km,under the RCP4.5 and RCP8.5 pathways.Four modified ETCCDI extreme indices-namely,SNOWTOT,S1mm,S10mm,and Sx5day-are employed to characterize the extreme snowfall events.RegCM4 generally reproduces the spatial distribution of the indices over the region,although with a tendency of overestimation.For the projected changes,a general decrease in SNOWTOT is found over most of the TP,with greater magnitude and better cross-simulation agreement over the eastern part.All the simulations project an overall decrease in S1mm,ranging from a 25%decrease in the west and to a 50%decrease in the east of the TP.Both S10mm and Sx5day are projected to decrease over the eastern part and increase over the central and western parts of the TP.Notably,S10mm shows a marked increase(more than double)with high cross-simulation agreement over the central TP.Significant increases in all four indices are found over the Tarim and Qaidam basins,and northwestern China north of the TP.The projected changes show topographic dependence over the TP in the latitudinal direction,and tend to decrease/increase in low-/high-altitude areas. 展开更多
关键词 Extreme snowfall Regional climate model Tibetan plateau Climate change
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Climate change drives flooding risk increases in the Yellow River Basin 被引量:1
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作者 Hengxing Lan Zheng Zhao +9 位作者 Langping Li Junhua Li Bojie Fu Naiman Tian Ruixun Lai Sha Zhou Yanbo Zhu Fanyu Zhang Jianbing Peng John J.Clague 《Geography and Sustainability》 CSCD 2024年第2期193-199,共7页
The Yellow River Basin(YRB)has experienced severe floods and continuous riverbed elevation throughout history.Global climate change has been suggested to be driving a worldwide increase in flooding risk.However,owing ... The Yellow River Basin(YRB)has experienced severe floods and continuous riverbed elevation throughout history.Global climate change has been suggested to be driving a worldwide increase in flooding risk.However,owing to insufficient evidence,the quantitative correlation between flooding and climate change remains illdefined.We present a long time series of maximum flood discharge in the YRB dating back to 1843 compiled from historical documents and instrument measurements.Variations in yearly maximum flood discharge show distinct periods:a dramatic decreasing period from 1843 to 1950,and an oscillating gentle decreasing from 1950 to 2021,with the latter period also showing increasing more extreme floods.A Mann-Kendall test analysis suggests that the latter period can be further split into two distinct sub-periods:an oscillating gentle decreasing period from 1950 to 2000,and a clear recent increasing period from 2000 to 2021.We further predict that climate change will cause an ongoing remarkable increase in future flooding risk and an∼44.4 billion US dollars loss of floods in the YRB in 2100. 展开更多
关键词 Flooding risk Risk management Climate change Flood discharge Extreme precipitation
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