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Effects of electrolyte balance on intestinal barrier, amino acid metabolism, and mTORC1 signaling pathway in piglets fed lowprotein diets

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Animal Nutrition 2024年第2期17卷 408-417页

作者： Qian Lin Xiaodian Tu Xin Li Feiyang Gou Lin Ding Zeqing Lu Jie Feng Yongfei Ying Caihong Hu College of Animal Sciences Zhejiang University Key Laboratory of Molecular Animal Nutrition (Zhejiang University) Ministry of Education Animal Husbandry Technology Promotion and Breeding Livestock and Poultry monitoring station of Zhejiang Province

A proper dietary electrolyte balance(dEB) is essential to ensure optimal growth performance of piglets. In the low-protein diet, this balance may be affected by the reduction of soybean meal and the inclusion of high levels of synthetic amino acids. The objective of this experiment was to evaluate the optimal dEB of low-protein diets and its impact on the growth performance of piglets. A total of 108 piglets(initial age of35 d) were randomly divided into 3 groups with 6 replicates of 6 pigs each as follows: low electrolyte diet(LE group; dEB = 150 milliequivalents [mEq]/kg); medium electrolyte diet(ME group; dEB = 250 m Eq/kg);high electrolyte diet(HE group; d EB = 350 mEq/kg). Results indicated that the LE and HE diet significantly decreased the average daily gain, average daily feed intake, and crude protein digestibility(P < 0.05) in piglets. Meanwhile, LE diets disrupted the structural integrity of the piglets' intestines and decreased jejunal tight junction protein(occludin and claudin-1) expression(P < 0.05). Additionally, the pH and HCO3 in the arterial blood of piglets in the LE group were lower than those in the ME and HE groups(P < 0.05).Interestingly, the LE diet significantly increased lysine content in piglet serum(P < 0.05), decreased the levels of arginine, leucine, glutamic acid, and alanine(P < 0.05), and inhibited the mammalian target of rapamycin complex 1(mTORC1) pathway by decreasing the phosphorylation abundance of key proteins. In summary, the dietary electrolyte imbalance could inhibit the activation of the mTORC1 signaling pathway,which might be a key factor in the influence of the dEB on piglet growth performance and intestinal ***, second-order polynomial(quadratic) regression analysis showed that the optimal dEB of piglets in the low-protein diet was 250 to 265 mEq/kg.

关键词： Low-protein Dietary electrolyte balance Piglet Mammalian target of rapamycin complex 1

Systematic and long-term technical validity of toxicity determination and early warning of heavy metal pollution based on an automatic water-toxicity-determination-system

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Frontiers of Environmental Science & Engineering 2024年第8期18卷 59-71页

作者： Yue Yi Baoguo Wang Xuemei Yi Fan Zha Haisen Lin Zhijun Zhou Yanhong Ge Hong Liu School of Life Science Beijing Institute of TechnologyBeijing 100081China Institute of Environmental Biology and Life Support Technology School of Biological Science and Medical EngineeringBeihang UniversityBeijing 100191China Infore Environment Technology Group Foshan 528000China Jiangmen Ecological Environment monitoring station Jiangmen 529000China Guangzhou Sub-branch of Guangdong Ecological and Environmental monitoring Center Guangzhou 510000China

Water toxicity determination with electrochemically active bacteria(EAB)shows promise for providing early warnings for heavy metal pollution in ***,thus far,only idealized tests with a few types of heavy metals have been *** this study,an automatic water-toxicitydetermination system with high technical maturity was established,and the toxicological properties of common heavy metals were systematically *** results demonstrated that the common heavy metals linearly inhibited EAB currents in the range of 0.1 mg/L to 0.5 mg/*** toxicity ranking of the tested heavy metals was Pb^(2+)>Tl^(3+)>Cu^(2+)>Cd^(2+)>Zn^(2+)>Ni^(2+)>Hg^(2+)>As^(3+).The toxicity interaction mainly exhibited an antagonistic effect in binary heavy metal *** system can accurately determine surface water toxicity and rapidly monitor heavy metal pollution,with good repeatability and a long ***,this study demonstrates that EAB are capable of long-term(>60 d)surface water quality monitoring and on-site early warning of heavy metal pollution.

关键词： Biological early warning system Electrochemically active bacteria Water toxicity determination Biosensor Heavy metal pollution Early warning

Comparison of fish communities using environmental DNA metabarcoding and capture methods in a plateau Erhai Lake,China

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Journal of Oceanology and Limnology 2024年第5期42卷 1597-1608页

作者： Hong CHEN Wanchao HE Fenge YANG Li LIAO Chengjie YIN Yushun CHEN Longgen GUO State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China University of Chinese Academy of Sciences Beijing 100049China Dali monitoring station of Yunnan Ecology and Environment Bureau Dali 671000China

Environmental DNA(eDNA)has been used as an important tool for fish diversity analysis,which can greatly solve the problems in traditional survey ***,little work has been done on the actual monitoring accuracy of *** this study,we analyzed the current status of fish resources in Erhai Lake in Yunnan,SW China,by dividing the lake into three sectors according to habitat differences,and compared the results of eDNA and traditional capture methods to investigate the shortcomings of the current analysis of eDNA results.A total of 27 fish species were detected by eDNA and traditional capture methods,including 20 and 19 fish species,respectively,and additional differences in fish composition between the two *** alpha diversity showed higher fish abundance and lower fish diversity by eDNA method compared to the traditional capture method,demonstrating that eDNA was not superior for use in fish diversity *** community similarity analysis showed that community differences were generally significant for eDNA(P<0.05).RDA analysis indicated that environmental factors did not significantly affect fish communities monitored by the eDNA ***,water temperature,aquatic plants,and water depth had significant(P<0.05)effects on fish communities in the traditional capture method,suggesting that eDNA results are insensitive to the effects of environmental *** results illustrate the effectiveness of eDNA in fish identification and the issues in quantification compared to traditional capture ***,combining eDNA with traditional methods is a more effective method for analyzing eDNA metabarcoding,following which the protocols of both quantitative methods can be designed to explore the regularity of eDNA quantification.

关键词： environmental DNA traditional capture method fish communities habitat differences Erhai Lake

Unveiling evapotranspiration patterns and energy balance in a subalpine forest of the Qinghai-Tibet Plateau:observations and analysis from an eddy covariance system

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Journal of Forestry Research 2024年第3期35卷 175-188页

作者： Niu Zhu Jinniu Wang Dongliang Luo Xufeng Wang Cheng Shen Ning Wu Ning Zhang Binghui Tian Aihong Gai Chengdu Institute of Biology Chinese Academy of SciencesChengdu 610041People's Republic of China College of Resources and Environmental Sciences Gansu Agricultural UniversityLanzhou 730070People's Republic of China Mangkang Ecological monitoring station Tibet Ecological Security Barrier Ecological Monitoring NetworkQamdo 854500People's Republic of China Northwest Institute of Eco Environmental Resources Chinese Academy of SciencesLanzhou 730000People's Republic of China

Evapotranspiration is an important parameter used to characterize the water cycle of *** under-stand the properties of the evapotranspiration and energy balance of a subalpine forest in the southeastern Qinghai-Tibet Plateau,an open-path eddy covariance system was set up to monitor the forest from November 2020 to October 2021 in a core area of the Three Parallel Rivers in the Qing-hai-Tibet *** results show that the evapotranspira-tion peaked daily,the maximum occurring between 11:00 and 15:*** factors had significant effects on evapotranspiration,among them,net radiation the greatest(R^(2)=0.487),and relative humidity the least(R^(2)=0.001).The energy flux varied considerably in different seasons and sensible heat flux accounted for the main part of turbulent *** energy balance ratio in the dormant season was less than that in the growing season,and there is an energy imbalance at the site on an annual time scale.

关键词： Evapotranspiration Energy balance Subalpine forest Three Parallel Rivers region Southeast Qinghai-Tibet Plateau

Effects of the conversion of natural tropical rainforest to monoculture rubber plantations on soil hydrological processes

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Journal of Plant Ecology 2024年第2期17卷 122-133页

作者： Qiaoyan Chen Ruiyu Fu Siyuan Cheng Dong Qiao Zhongmin Hu Zijia Zhang Licong Dai Hainan Baoting Tropical Rainforest Ecosystem Observation and Research station School of Ecology and EnvironmentHainan UniversityHaikou 570228China Center for Eco-Environment Restoration Engineering of Hainan Province Hainan UniversityHaikou 570228China Hainan Ecological Environment monitoring Center Haikou 570100China

Rubber plantations have increased signifcantly under unprecedented economic growth in tropical areas,which leads to soil degradation and thereby alters soil hydrological ***,our understanding of how forest conversion affects soil hydrological processes remains ***,we collected soil samples from secondary forests(SF)and rubber plantations(RP)to determine the soil hydrological *** found the topsoil(0-20 cm)water retention in SF was higher than that of RP but displayed the contrast pattern in a deeper soil layer(20-60 cm).Meanwhile,the soil infltration rates among the two vegetation types decreased signifcantly with infltration time,with higher stable soil infltration rates in SF than those in ***,soil properties were also impacted by the forest conversion,such as the topsoil capillary porosity(CP)and total porosity(TP)in SF were higher than those of RP but contrasted in a deep soil *** comparison,the topsoil bulk density(BD)in SF was lower than that of RP,but contrasted in the deep soil layer and reached a signifcant level in the 0-10 and 40-50 cm(P<0.05).Overall,the soil water retention was mainly determined by the CP,which could explain 31.56%of the total variance in soil water retention,followed by TP(26.57%)and soil BD(26.47%),whereas soil texture exerts a weak effect on soil water ***,we can conclude that the conversion of tropical rainforest into rubber plantations may accelerate soil erosion owing to its lower topsoil water retention and soil infltration rates.

关键词： soil water retention soil infltration soil physicochemical properties rubber plantations secondary forest

Quantitative contributions of climate change and human activities to vegetation dynamics in the Zoige Plateau from 2001 to 2020

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Journal of Mountain Science 2024年第9期21卷 3031-3046页

作者： GAO Bing LIU Enqin YANG Yang YANG Man YAO Yang GUAN Lei FENG Yiwen College of Geography and Planning Chengdu University of TechnologyChengdu 610059China Key Laboratory of Smart Earth Beijing 100029China Sichuan Provincial Soil and Water Conservation Ecological Environment monitoring station Chengdu 610041China College of Earth and Planetary Sciences Chengdu University of TechnologyChengdu 610059China

Climate change and human activities such as overgrazing and rapid development of tourism simultaneously affected the vegetation of the Zoige ***,the spatiotemporal variations of vegetation and the relative contributions of climate change and human activities to these vegetation dynamics remain ***,clarifying how and why the vegetation on the Zoige Plateau changed can provide a scientific basis for the sustainable development of the ***,we investigate NDVI trends using the Normalized Difference Vegetation Index(NDVI)as an indicator of vegetation greenness and distinguish the relative effects of climate changes and human activities on vegetation changes by utilizing residual trend analysis and the *** find a tendency of vegetation greening from 2001 to 2020,with significant greening accounting for 21.44%of the entire ***,browning area expanded rapidly after *** temperatures are the primary driver of vegetation changes in the Zoige *** variations and human activities were responsible for 65.57%and 34.43%of vegetation greening,and 39.14%and 60.86%of vegetation browning,respectively,with browning concentrated along the Yellow,Black and White *** to 2001-2010,the inhibitory effect of human activity and climate fluctuations on vegetation grew dramatically between 2011 and 2020.

关键词： Vegetation change Climate change Residual trend analysis Geodetector Human activities Zoige plateau

A Quantitative seismic Topographic Effect Prediction Method Based upon BP Neural Network Algorithm and FEM Simulation

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Journal of Earth Science 2024年第4期35卷 1355-1366页

作者： Qifeng Jiang Mianshui Rong Wei Wei Tingting Chen Shandong seismic Hazard Prevention Center Shandong Earthquake AgencyJinan250014China Shandong Institute of Earthquake Engineering Jinan250021China Key Laboratory of Urban Security and Disaster Engineering of China Ministry of Education Beijing University of TechnologyBeijing100124China Publicity and Education Center Shandong Earthquake AgencyJinan250014China Shandong Earthquake station Shandong Earthquake AgencyJinan250014China

Topography can strongly affect ground motion,and studies of the quantification of hill surfaces’topographic effect are relatively *** this paper,a new quantitative seismic topographic effect prediction method based upon the BP neural network algorithm and three-dimensional finite element method(FEM)was *** FEM simulation results were compared with seismic records and the results show that the PGA and response spectra have a tendency to increase with increasing elevation,but the correlation between PGA amplification factors and slope is not obvious for low *** BP neural network models were established for the prediction of amplification factors of PGA and response *** kinds of input variables’combinations which are convenient to achieve are proposed in this paper for the prediction of amplification factors of PGA and response spectra,*** absolute values of prediction errors can be mostly within 0.1 for PGA amplification factors,and they can be mostly within 0.2 for response spectra’s amplification *** input variables’combination can achieve better prediction performance while the other one has better expandability of the predictive ***,the BP models only employ one hidden layer with about a hundred nodes,which makes it efficient for training.

关键词： seismic topographic effect finite element method BP neural network algorithm earthquake disaster prevention

Spatial-temporal differentiation and influencing factors of rural settlements in mountainous areas: an example of Liangshan Yi Autonomous Prefecture, Southwestern China

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Journal of Mountain Science 2024年第1期21卷 218-235页

作者： WANG Yumeng DENG Qingchun YANG Haiqing LIU Hui YANG Feng ZHAO Yakai School of Geographical Sciences China West Normal UniversityNanchong 637009China Sichuan Provincial Engineering Laboratory of monitoring and Control for Soil Erosion in Dry Valleys China West Normal UniversityNanchong 637009China Liangshan Soil Erosion and Ecological Restoration in Dry Valleys Observation and Research station Xide 616753China

Rural settlement is the basic spatial unit for compact communities in rural area. Scientific exploration of spatial-temporal differentiation and its influencing factors is the premise of spatial layout rationalization. Based on land use data of Liangshan Yi Autonomous Prefecture(hereinafter referred to as Liangshan Prefecture) in Sichuan Province, China from 1980 to 2020, compactness index, fractal dimension, imbalance index, location entropy and the optimal parameters-based geographical detector(OPGD) model are used to analyze the spatial-temporal evolution of the morphological characteristics of rural settlements, and to explore the influence of natural geographical factors, socioeconomic factors, and policy factors on the spatial differentiation of rural settlements. The results show that:(1) From 1980 to 2020, the rural settlements area in Liangshan Prefecture increased by 15.96 km^(2). In space, the rural settlements are generally distributed in a local aggregation, dense in the middle and sparse around the periphery. In 2015, the spatial density and expansion index of rural settlements reached the peak.(2) From 1980 to 2020, the compactness index decreased from 0.7636 to 0.7496, the fractal dimension increased from 1.0283 to 1.0314, and the fragmentation index decreased from 0.1183 to 0.1047. The spatial morphological structure of rural settlements tended to be loose, the shape contour tended to be complex, the degree of fragmentation decreased, and the spatial distribution was significantly imbalanced.(3) The results of OPGD detection in 2015 show that the influence of each factor is slope(0.2371) > traffic accessibility(0.2098) > population(0.1403) > regional GDP(0.1325) > elevation(0.0987) > poverty alleviation(0). The results of OPGD detection in 2020 show that the influence of each factor is slope(0.2339) > traffic accessibility(0.2198) > population(0.1432) > regional GDP(0.1219) > poverty alleviation(0.0992) > elevation(0.093). Natural geographical facto

关键词： Rural settlements Location entropy Geographical detector Spatiotemporal differentiation Influencing factors

Atmospheric iron deposition in a megacity of northwest China:Solubility,speciation,and deposition fluxes

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Particuology 2024年第7期90卷 383-393页

作者： Xiaotao Yang Pingping Liu Zhiwei Xue Hao Zhang Xuan Li Hongmei Xu Zhenxing Shen Department of Environmental Science and Engineering Xi'an Jiaotong UniversityXi'anChina State Key Laboratory of Loess and Quaternary National Key R&D of China Geology Institute of Earth EnvironmentChinese Academy of SciencesXi'anChina No.203 Research Institute of Nuclear Industry Xi'an710086China Xi'an Environmental monitoring station Xi'an 710054China

Atmospheric iron has crucial effects on biogeochemical cycles,atmospheric processing,global climate,and human *** this study,atmospheric dustfall samples were collected from six functional areas in Xi'an,China,from 2020 to *** spatiotemporal distributions and deposition fluxes of total and water-soluble(ws)Fe as well as the speciation and potential sources of ws-Fe were *** areas had the highest concentrations of total Fe and ws-Fe,which were mainly due to copious emissions of heavy metals during *** total Fe concentrations peaked in spring,primarily due to the substantial input of crustal dust,which also led to the lowest Fe solubility in this *** contrast,the highest levels of ws-Fe occurred during winter due to an increase in biomass *** the water-soluble forms,ws-Fe(II)was dominant and accounted for 74.8%of the total amount of *** dust was the main contributor to total Fe,whereas biomass burning primarily contributed to peak ws-Fe *** average total and ws-Fe deposition fluxes in Xi'an were the highest in spring and lowest in autumn,which were related to the distributions of the dustfall deposition fluxes and their Fe contents during these *** study provided a broader and comprehensive understanding of atmospheric iron deposition in Chinese urban area,which is of positive significance for understanding atmospheric chemistry and global climate change.

关键词： Atmospheric dustfall Iron Speciation distribution Seasonal variation Functional area Sources