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Using machine learning algorithms to estimate stand volume growth of Larix and Quercus forests based on national-scale Forest Inventory data in China 被引量:2
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作者 Huiling Tian Jianhua Zhu +8 位作者 Xiao He xinyun chen Zunji Jian chenyu Li Qiangxin Ou Qi Li Guosheng Huang Changfu Liu Wenfa Xiao 《Forest Ecosystems》 SCIE CSCD 2022年第3期396-406,共11页
Estimating the volume growth of forest ecosystems accurately is important for understanding carbon sequestration and achieving carbon neutrality goals.However,the key environmental factors affecting volume growth diff... Estimating the volume growth of forest ecosystems accurately is important for understanding carbon sequestration and achieving carbon neutrality goals.However,the key environmental factors affecting volume growth differ across various scales and plant functional types.This study was,therefore,conducted to estimate the volume growth of Larix and Quercus forests based on national-scale forestry inventory data in China and its influencing factors using random forest algorithms.The results showed that the model performances of volume growth in natural forests(R^(2)=0.65 for Larix and 0.66 for Quercus,respectively)were better than those in planted forests(R^(2)=0.44 for Larix and 0.40 for Quercus,respectively).In both natural and planted forests,the stand age showed a strong relative importance for volume growth(8.6%–66.2%),while the edaphic and climatic variables had a limited relative importance(<6.0%).The relationship between stand age and volume growth was unimodal in natural forests and linear increase in planted Quercus forests.And the specific locations(i.e.,altitude and aspect)of sampling plots exhibited high relative importance for volume growth in planted forests(4.1%–18.2%).Altitude positively affected volume growth in planted Larix forests but controlled volume growth negatively in planted Quercus forests.Similarly,the effects of other environmental factors on volume growth also differed in both stand origins(planted versus natural)and plant functional types(Larix versus Quercus).These results highlighted that the stand age was the most important predictor for volume growth and there were diverse effects of environmental factors on volume growth among stand origins and plant functional types.Our findings will provide a good framework for site-specific recommendations regarding the management practices necessary to maintain the volume growth in China's forest ecosystems. 展开更多
关键词 Stand volume growth Stand origin Plant functional type National forest inventory data Random forest algorithms
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Epidemiology of community pre-hypertensive patients and related risk factors in Chengdu city
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作者 xinyun chen Yafei Yan +8 位作者 Fang Qin Xiaojing Jiang Bo Yu Fang Shang Jian Liu Yuelei Wu Dan Tang Yuanyuan Yao Tingjie Zhang 《Family Medicine and Community Health》 2013年第3期27-32,共6页
Objective:This study aims to explore the epidemiologic characteristics of pre-hypertension,its related risk factors of cardiovascular diseases and its relativity with metabolic disorders among community residents of C... Objective:This study aims to explore the epidemiologic characteristics of pre-hypertension,its related risk factors of cardiovascular diseases and its relativity with metabolic disorders among community residents of Chengdu city.Methods:Cluster random sampling was performed in three districts and counties of Chengdu.A total of 3524 residents(resident for≥1 year,≥18 years of age)were enrolled in the investigation.All the participants were interviewed in the questionnaire survey.Physical examination,blood pressure measurements,and blood sampling were also performed.Results:The overall prevalence of pre-hypertension was 34.07%.The prevalence of prehyper-tension was higher in males than in females(41.16%vs.23.89%,P<0.05).The prevalence of pre-hypertension among patients with systolic/diastolic blood pressures of 120-129 mmHg/80-84 mmHg and 130-139 mmHg/85-89 mmHg were 34.90%and 17.16%,respectively.The prevalence of pre-hypertension increased with age,reaching a peak at 30-39 years(39.93%),and then declined.Multi-ple risk factors for cardiovascular disease were more common in patients with hypertension and pre-hypertension than in the population with normal blood pressure.Pre-hypertension was associated with increased fasting blood glucose and increased relative risks of hypertriglyceridemia,hyperuricemia,overweight,obesity,and abdominal obesity,compared with patients who had normal blood pressure.Conclusion:The prevalence of pre-hypertension in residents of Chengdu was high.Multiple metabolic disorders were already present in the population,and multiple cardiovascular disease risk factors were more common than in the population with normal blood pressure.Early screening for cardiovascular risk factors should be performed in patients with pre-hypertension.In addition,comprehensive measures,such as lifestyle improvement and medications,should be implemented. 展开更多
关键词 PRE-HYPERTENSION Epidemiological characteristics Multiple metabolic disorders Cardiovascular risk factor Early screening Lifestyle improvement
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The roles of Mesp family proteins: functional diversity and redundancy in differentiation of pluripotent stem cells and mammalian mesodermal development
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作者 Qianqian Liang chen Xu +8 位作者 xinyun chen Xiuya Li Chao Lu Ping Zhou Lianhua Yin Ruizhe Qian Sifeng chen Zhendong Ling Ning Sun 《Protein & Cell》 SCIE CAS CSCD 2015年第8期553-561,共9页
Mesp family proteins comprise two members named mesodermal posterior 1 (Mespl) and mesodermal pos- terior 2 (Mesp2). Both Mespl and Mesp2 are transcrilption factors and they share an almost identical basic helix-l... Mesp family proteins comprise two members named mesodermal posterior 1 (Mespl) and mesodermal pos- terior 2 (Mesp2). Both Mespl and Mesp2 are transcrilption factors and they share an almost identical basic helix-loop-helix motif. They have been shown to play critical regulating roles in mammalian heart and somite development. Mespl sits in the core of the complicated regulatory network for generation of cardiovascular progenitors while Mesp2 is central for somitogenesis. Here we summarize the similarities and differences in their molecular functions during mammalian early mesodermal development and discuss possible future research directions for further study of the functions of Mespl and Mesp2. A comprehensive knowledge of molecular functions of Mesp family proteins will even- tually help us better understand mammalian heart development and somitogenesis as well as improve the production of specific ceil types from pluripotent stem cells for future regenerative therapies. 展开更多
关键词 Mesp transcription factor pluripotent stemcells cardiovascular differentiation SOMITOGENESIS
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