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Soil bacterial and fungal communities resilience to long-term nitrogen addition in subtropical forests in China
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作者 Xinlei Fu Yunze Dai +3 位作者 Jun Cui Pengfei Deng Wei Fan Xiaoniu Xu 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期95-108,共14页
Atmospheric nitrogen(N)deposition is predicted to increase,especially in the subtropics.However,the responses of soil microorganisms to long-term N addition at the molecular level in N-rich subtropical forests have no... Atmospheric nitrogen(N)deposition is predicted to increase,especially in the subtropics.However,the responses of soil microorganisms to long-term N addition at the molecular level in N-rich subtropical forests have not been clarified.A long-term nutrient addition experiment was conducted in a subtropical evergreen old-growth forest in China.The four treatments were:control,low N(50 kg N ha^(-1)a^(-1)),high N(100 kg N ha^(-1)a^(-1)),and combined N and phosphorus(P)(100 kg N ha^(-1)a^(-1)+50 kg P ha^(-1)a^(-1)).Metagenomic sequencing characterized diversity and composition of soil microbial communities and used to construct bacterial/fungal co-occurrence networks.Nutrient-treated soils were more acidic and had higher levels of dissolved organic carbon than controls.There were no significant differences in microbial diversity and community composition across treatments.The addition of nutrients increased the abundance of copiotrophic bacteria and potentially beneficial microorganisms(e.g.,Gemmatimonadetes,Chaetomium,and Aureobasidium).Low N addition increased microbiome network connectivity.Three rare fungi were identified as module hubs under nutrient addition,indicating that low abundance fungi were more sensitive to increased nutrients.The results indicate that the overall composition of microbial communities was stable but not static to long-term N addition.Our findings provide new insights that can aid predictions of the response of soil microbial communities to long-term N addition. 展开更多
关键词 long-term nitrogen addition Old-growth subtropical forest METAGENOMICS Beneficial microorganisms Co-occurrence network
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Community-led total sanitation(CLTS)implementation in West Mamprusi Municipal Assembly in Ghana.What do communities think eleven years on?
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作者 Elijah Adam Emmanuel Badu 《Global Health Journal》 2024年第2期67-73,共7页
Objective Access to improved sanitation is a fundamental human right and an important aspect of Public Health.However,an estimated thousands of people in Ghana especially,the West Mamprusi Municipal Assembly(WMMA)stil... Objective Access to improved sanitation is a fundamental human right and an important aspect of Public Health.However,an estimated thousands of people in Ghana especially,the West Mamprusi Municipal Assembly(WMMA)still have no access to adequate toilet facilities.This has brought untold health repercussions to the inhabitants,the community,and the environment at large.To address this menace,the community-led total sanitation(CLTS)was implemented.This study aimed to assess communities’perspectives on the implementation of CLTS and to understand the factors influencing its success and failures.Methods A mixed-method approach involving sequential qualitative and quantitative methods was employed in this study.Participants for the quantitative study were randomly selected and surveyed using questionnaires.The qualitative study employed focus group discussion involving purposively sampled participants including assembly members,opinion leaders,and assembly staff.Results The CLTS program in WMMA realized an apparent use of construction and proper use of household latrines leading to a reduction of open defecation free(ODF)and two communities achieving sanitized status in the history of the study area,enabling the training of latrine artisans and natural leaders to facilitate the CLTS expansion and sustainability,improved sanitation and hygiene,strengthened the enforcement of community rules and regulations and many others.Conclusion The CLTS program has received more widespread acceptance in the study area than the previous government policy of constructing public toilets,which was greeted with massive failures due to poor implementation.To ensure that gains achieved through CLTS implementation are sustained longer,it is recommended that chiefs and opinion leaders should be involved in the CLTS programs to ensure checks and enforcement.The entrenchment of bylaws and more education to address enduring myths and misconceptions will sustain the program.Subsidies in the form of sanitation loans for latrine construction materials by the government and supporting non-governmental organizations(NGOs)will be paramount in sustaining ODF. 展开更多
关键词 community-led total sanitation(CLTS) community development Ghana SANITATION
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Analysis of Distribution of Public Toilets within Walking Range around Communities of the Elderly under the Model of Community Home-based Care for the Elderly: A Case Study of Changxindian, Fengtai District, Beijing
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作者 TIAN Jiaqi ZHANG Miao HU Yan 《Journal of Landscape Research》 2024年第2期35-37,41,共4页
In recent years,under the influence of multiple factors such as traditional ideas and living economic conditions,the aging population in China continues to increase.Most of the elderly are more inclined to aged at hom... In recent years,under the influence of multiple factors such as traditional ideas and living economic conditions,the aging population in China continues to increase.Most of the elderly are more inclined to aged at home,and the first places for elderly activities are communities and the surrounding environment,which greatly affects the convenience of life and happiness of the elderly.In this paper,Changxindian area in Fengtai District of Beijing was as the research object,and detailed calculation and analysis were carried out by using POI data and arcGIS software.The relative location of residential areas and surrounding public toilets was explored,and the best location of public toilets in the daily walking area under the model of community home-based care for the elderly was further studied. 展开更多
关键词 Home-based care for the elderly The elderly Public toilets community
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Imperative for long-term management and surveillance in Kawasaki disease
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作者 Yan Pan Fu-Yong Jiao 《World Journal of Clinical Cases》 SCIE 2025年第4期61-63,共3页
Kawasaki disease(KD)is a significant pediatric vasculitis known for its potential to cause severe coronary artery complications.Despite the effectiveness of initial treatments,such as intravenous immunoglobulin,KD pat... Kawasaki disease(KD)is a significant pediatric vasculitis known for its potential to cause severe coronary artery complications.Despite the effectiveness of initial treatments,such as intravenous immunoglobulin,KD patients can experience long-term cardiovascular issues,as evidenced by a recent case report of an adult who suffered a ST-segment elevation myocardial infarction due to previous KD in the World Journal of Clinical Cases.This editorial emphasizes the critical need for long-term management and regular surveillance to prevent such complications.By drawing on recent research and case studies,we advocate for a structured approach to follow-up care that includes routine cardiac evaluations and preventive measures. 展开更多
关键词 Kawasaki disease long-term management Coronary artery aneurysm SURVEILLANCE Preventive care
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Long-term changes of phytoplankton community in Xiagu waters of Xiamen,China 被引量:15
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作者 CHEN Baohong XU Zhuhua +4 位作者 ZHOU Qiulin CHEN Changping GAO Yahui YANG Shengyun JI Weidong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2010年第6期104-114,共11页
Long-term changes of phytoplankton community by water sampling method in Xiagu Sea waters of Xiamen,China,were investigated in this study.Species composition of the phytoplankton community in these waters changed grea... Long-term changes of phytoplankton community by water sampling method in Xiagu Sea waters of Xiamen,China,were investigated in this study.Species composition of the phytoplankton community in these waters changed greatly since the 1950s.The numbers of Dinophyta species increased significantly,although Bacillariophyta species are generally dominant.The succession of dominant species in phytoplankton community is obvious: large-size dominant species such as Biddulphia sinensis of the 1950s were gradually replaced by small-size ones such as Cyclotella striata and Nitzschia closterium,and species that still maintain dominant such as Skeletonema costatum are also small ones,leading the whole phytoplankton community of smaller size.Cell density of phytoplankton community increased greatly,among which cell density of the most dominant species Skeletonema costatum have been increasing in exponent function.Margalef index of phytoplankton community decreased,indicating decline of biodiversity of the community,and dominant character of Skeletonema costatum increased.Generally,the structure of the entire phytoplankton community is becoming more and more singular and unstable,which makes the occurrence of red tides more frequent.The succession in the phytoplankton community is related to the long-term changes in marine environment,influenced by human activities and global climate changes,especially the increases of nutrient content. 展开更多
关键词 PHYTOPLANKTON community structure XIAMEN water sampling long-term
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Interaction of soil microbial communities and phosphorus fractions under long-term fertilization in paddy soil 被引量:4
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作者 Muhammad QASWAR Waqas AHMED +8 位作者 HUANG Jing LIU Kai-lou ZHANG Lu HAN Tian-fu DU Jiang-xue Sehrish ALI Hafeez UR-RAHIM HUANG Qing-hai ZHANG Hui-min 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2022年第7期2134-2144,共11页
Understanding the impact of biological activities on the soil phosphorus(P)distribution under long-term fertilizer application can facilitate better soil P fertility management.Therefore,the primary objectives of this... Understanding the impact of biological activities on the soil phosphorus(P)distribution under long-term fertilizer application can facilitate better soil P fertility management.Therefore,the primary objectives of this study were to investigate the effect of long-term(since 1981)fertilizer application on the soil P fractions and microbial community and to evaluate correlations between the microbial community structure and P distribution.The following treatments were implemented in a long-term field trial:no fertilization(CK),inorganic N and K(NK),inorganic P and K(PK),inorganic N,P and K(NPK)and manure+NPK(MNPK)fertilization.The study showed that the soil pH,soil organic carbon and total and available N and P concentrations were considerably higher in the MNPK treatment than in the CK treatment.The soil microbial biomass C,N and P concentrations were also significantly higher in the MNPK treatment than in the CK treatment.Among fertilization treatments,theβ-1,4-glucosidase,α-1,4-glucosidase,urease,acid phosphatase and phosphodiesterase activities were the highest in the MNPK treatment.Compared to inorganic fertilization,the MNPK treatment increased the labile soil P fractions and decreased the residual soil P concentration.Continuous fertilization significantly affected the soil microbial composition.The total phospholipid fatty acid(PLFA)concentrations in the NK,PK,NPK and MNPK treatments were 23.3,43.1,48.7 and 87.7%higher,respectively,than in the CK treatment.A significant correlation was observed between the microbial community and soil P fractions.Moreover,the aggregated boosted tree(ABT)model showed that among the various soil biochemical properties,the total PLFA concentration was the factor that most influenced the active P pool,accounting for 35.4%of the relative influence of all soil biochemical properties examined.These findings reveal that combined manure and inorganic fertilizer application is a better approach than applying inorganic fertilizer alone for sustaining long-term P fertility by mediating soil biological activity. 展开更多
关键词 enzyme activities long-term fertilization microbial community microbial biomass phosphorus fraction
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Bacterial Community Structure and Diversity in a Black Soil as Affected by Long-Term Fertilization 被引量:46
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作者 WEI Dan YANG Qian +4 位作者 ZHANG Jun-Zheng WANG Shuang CHEN Xue-Li ZHANG Xi-Lin LI Wei-Qun 《Pedosphere》 SCIE CAS CSCD 2008年第5期582-592,共11页
Black soil (Mollisol) is one of the main soil types in northeastern China. Biolog and polymerase chain reactiondenaturing gradient gel electrophoresis (PCR-DGGE) methods were used to examine the influence of vario... Black soil (Mollisol) is one of the main soil types in northeastern China. Biolog and polymerase chain reactiondenaturing gradient gel electrophoresis (PCR-DGGE) methods were used to examine the influence of various fertilizer combinations on the structure and function of the bacterial community in a black soil collected from Harbin, Heilongjiang Province. Biolog results showed that substrate richness and catabolic diversity of the soil bacterial community were the greatest in the chemical fertilizer and chemical fertilizer+manure treatments. The metabolic ability of the bacterial community in the manure treatment was similar to the control. DGGE fingerprinting indicated similarity in the distribution of most 16S rDNA bands among all treatments, suggesting that microorganisms with those bands were stable and not influenced by fertilization. However, chemical fertilizer increased the diversity of soil bacterial community. Principal com- ponent analysis of Biolog and DGGE data revealed that the structure and function of the bacterial community were similar in the control and manure treatments, suggesting that the application of manure increased the soil microbial population, but had no effect on the bacterial community structure. Catabolic function was similar in the chemical fertilizer and chemical fertilizer+manure treatments, but the composition structure of the soil microbes differed between them. The use of chemical fertilizers could result in a decline in the catabolic activity of fast-growing or eutrophic bacteria. 展开更多
关键词 bacteria community black soil chemical fertilizer DIVERSITY MANURE
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Long-term ecological interactions between nutrient and phytoplankton community in the Changjiang estuary 被引量:9
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作者 江涛 俞志明 +2 位作者 宋秀贤 曹西华 袁涌铨 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第4期887-898,共12页
Both nitrate((NO_3)^-) and soluble reactive phosphate((PO_4)^(3-)) concentration in the freshwater end-member at the mouth of the Changjiang River have increased dramatically since the 1960s.Within the same period in ... Both nitrate((NO_3)^-) and soluble reactive phosphate((PO_4)^(3-)) concentration in the freshwater end-member at the mouth of the Changjiang River have increased dramatically since the 1960s.Within the same period in the sea area,with surface salinity>30,(NO_3)^-concentration has shown an obvious increase,(PO_4)^(3-) has not changed greatly and dissolved reactive silica((SiO_3)^(2-)) has deceased dramatically.An examination of the elemental ratio of(NO_3)^-to(PO_4)^(3-) at the mouth of the Changjiang River did not show a systematic trend from the 1960s to 2000s largely because both nutrients increased simultaneously.In comparison,the elemental ratio of dissolved inorganic nitrogen(DIN) to(PO_4)^(3-) in surface seawater,with salinity>22,has shown a clearly increasing trend.Furthermore,an overall historical change of the(SiO_3)^(2-):(PO_4)^(3-) ratio has undergone a reverse trend in this area.Based on the changes of(SiO_3)^(2-):(PO_4)^(3-) and DIN:(PO_4)^(3-) ratios,we can conclude that an overall historical change of(SiO_3)^(2-):DIN ratio has decreased in this area from the 1950-1960s to 2000s.The argument that phytoplankton productivity in the Changjiang estuary has been enhanced by increasing nutrient input from the riverine transport was supported by these results.A comparative study analyzing the shift of phytoplankton composition from the mid-1980s to 2000s was also made.The results indicated that the average yearly percentage of diatom species in the Changjiang estuary has decreased from 84.6% during 1985-1986 to 69.8% during 2004-2005.Furthermore,the average yearly percentage of diatom abundance in the Changjiang estuary decreased from 99.5% during to 75.5% over the same time period,while the abundance of dinoflagellates has increased dramatically,from 0.7% to 25.4%. 展开更多
关键词 EUTROPHICATION NUTRIENTS phytoplankton community Changjiang estuary
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Impact of Long-Term Fertilization on Community Structure of Ammonia Oxidizing and Denitrifying Bacteria Based on amoA and nirK Genes in a Rice Paddy from Tai Lake Region,China 被引量:9
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作者 JIN Zhen-jiang LI Lian-qing +3 位作者 LIU Xiao-yu PAN Gen-xing Qaiser Hussein LIU Yong-zhuo 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第10期2286-2298,共13页
Ammonia oxidizing (AOB) and denitrifying bacteria (DNB) play an important role in soil nitrogen transformation in natural and agricultural ecosystems. Effects of long-term fertilization on abundance and community ... Ammonia oxidizing (AOB) and denitrifying bacteria (DNB) play an important role in soil nitrogen transformation in natural and agricultural ecosystems. Effects of long-term fertilization on abundance and community composition of AOB and DNB were studied with targeting ammonia monooxygenase (amoA) and nitrite reductase (nirK) genes using polymerase chain reaction- denaturing gradient gel electrophoresis (PCR-DGGE) and real-time PCR, respectively. A field trial with different fertilization treatments in a rice paddy from Tai Lake region, centre East China was used in this study, including no fertilizer application (NF), balanced chemical fertilizers (CF), combined organic/inorganic fertilizer of balanced chemical fertilizers plus pig manure (CFM), and plus rice straw return (CFS). The abundances and riehnesses of amoA and nirK were increased in CF, CFM and CFS compared to NF. Principle component analysis of DGGE profiles showed significant difference in nirK and amoA genes composition between organic amended (CFS and CFM) and the non-organic amended (CF and NF) plots. Number of amoA copies was significantly positively correlated with normalized soil nutrient richness (NSNR) of soil organic carbon (SOC) and total nitrogen (T-N), and that of nirK copies was with NSNR of SOC, T-N plus total phosphorus. Moreover, nitrification potential showed a positive correlation with SOC content, while a significantly lower denitrification potential was found under CFM compared to under CFS. Therefore, SOC accumulation accompanied with soil nutrient richness under long-term balanced and organic/inorganic combined fertilization promoted abundance and diversity of AOB and DNB in the rice paddy. 展开更多
关键词 long-term fertilization ammonia oxidizing bacteria denitrifying bacteria abundance rice paddy
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Response of soil fungal community to long-term chromium contamination 被引量:10
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作者 Jin HU De-long MENG +3 位作者 Xue-duan LIU Yi-li LIANG Hua-qun YIN Hong-wei LIU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第9期1838-1846,共9页
To further study the fungal community in heavy metal contaminated ecosystems,soil samples were collected from an abandoned chromium(Cr)factory,and fungal community was analyzed by Illumina sequencing of Internal Trans... To further study the fungal community in heavy metal contaminated ecosystems,soil samples were collected from an abandoned chromium(Cr)factory,and fungal community was analyzed by Illumina sequencing of Internal Transcribed Spacer(ITS)amplicons.The results showed that Cr contamination changed the composition and structure of soil fungal community,but didn’t change the diversity.Fungus showed various responses to Cr contamination.LEfSe analysis revealed that the biomarker changed a lot in the Cr-contaminated samples in comparison with that in the control samples.The changes in fungal community may be caused by the direct toxic effects on fungi by high concentration of Cr and the significant change in soil properties resulting from Cr contamination.Among all the Cr fractions,organic matter-bound Cr and exchangeable Cr showed significant effects on the fungal community and organic matter also showed a significant effect on soil fungal community. 展开更多
关键词 fungal community ALPHA-DIVERSITY BETA-DIVERSITY Cr contamination high-throughput sequencing
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Responses of N_2O reductase gene(nosZ)-denitrifier communities to long-term fertilization follow a depth pattern in calcareous purplish paddy soil 被引量:5
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作者 WANG Ying-yan LU Sheng-e +5 位作者 XIANG Quan-ju YU Xiu-mei ZHAO Ke ZHANG Xiao-ping TU Shi-hua GU Yun-fu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第11期2597-2611,共15页
The effect of long-term fertilization on soil denitrifying communities was analysed by measuring the abundance and diversity of the nitrous oxide (N2O) reductase gene, nosZ. Soil samples were collected from plots of... The effect of long-term fertilization on soil denitrifying communities was analysed by measuring the abundance and diversity of the nitrous oxide (N2O) reductase gene, nosZ. Soil samples were collected from plots of a long-term fertilization experiment established in 1982 in Suining City, China. The fertilizer treatments were no fertilizer (CK), three chemical fertilizer (CF) treatments (N, NP, NPK), manure (M) alone, and manure with chemical fertilizers (NM, NPM, NPKM). The abundance and diversity of the denitrifying bacteria were assessed by real-time quantitative PCR, terminal restriction fragment length polymorphism (T-RFLP), and cloning and sequencing of nosZ genes. The diversity and abundance of nosZ-denitrifiers was higher in soil amended with manure and chemical fertilizers (CFM) than in soil amended with CF alone, and the highest in topsoil (0-20 cm). The nosZ-denitrifier community composition was more complex in CFM soil than in CF soil: Specific species were detected only in the CFM soil. The abundance of nosZ-denitrifier in the NPKM treatment was approximately two times higher than that in the CK, N, and NPK treatments. Most of the cloned nosZ sequences were closely related to nosZ sequences from Bradyrhizobiaceae and Rhodospirillaceae in Alphaproteobacteria. Of the measured abiotic factors, soil organic matter correlated significantly with the abundance (P〈0.01); available phosphorus correlated significantly with the topsoil community composition (P〈0.01), whereas soil organic matter correlated significantly with the subsoil (20-90 cm) community composition (P〈0.01). This study demonstrated that long-term CFM fertilization affected both the abundance and composition of the nosZ-denitrifier community. 展开更多
关键词 fertilization community abundance DENITRIFIERS soil depth
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Long-term rice-rice-green manure rotation changing the microbial communities in typical red paddy soil in South China 被引量:29
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作者 GAO Song-juan ZHANG Ren-gang +8 位作者 CAO Wei-dong FAN Yuan-yuan GAO Ju-sheng HUANG Jing BAI Jin-shun ZENG Nao-hua CHANG Dan-na Shimizu Katsu-yoshi Kristian Thorup-Kristensen 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2015年第12期2512-2520,共9页
On the basis of a long-term(30 years) field experiment that involved four rotation systems, rice-rice-winter fallow(RRF), rice-rice-ryegrass(RRG), rice-rice-rape(RRP), and rice-rice-milk vetch(RRV), this stu... On the basis of a long-term(30 years) field experiment that involved four rotation systems, rice-rice-winter fallow(RRF), rice-rice-ryegrass(RRG), rice-rice-rape(RRP), and rice-rice-milk vetch(RRV), this study described the effects of green manure on the microbial communities in the red paddy soils using 454 pyrosequencing for the 16 S r RNA gene. The Chao1 richness and non-parametric Shannon's index increased in all soil samples that received green manure treatments. The communities' structures with the green manure applications were significantly dissimilar from that under the winter fallow. Using Metastats tests, many genera in the RRG, RRP and RRV soils were significantly different from those in the RRF soil, including a number of genera that functioned in the nitrogen and sulfur cycles. Analyses of the genera with these functions revealed the shifts in microbial ecosystem functions after long-term green manuring. Changes in the microbial communities increased the ammonium supply and decreased the soil acidification in green-manure-amended soils. Together, these data suggested powerful effects of green manure on both the microbial communities and the biogeochemical cycle driven by the shifts in bacterial functional groups. 展开更多
关键词 green manure community structure community function 16S rRNA gene double rice
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A comprehensive analysis of the response of the fungal community structure to long-term continuous cropping in three typical upland crops 被引量:11
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作者 LIU Hang PAN Feng-juan +4 位作者 HAN Xiao-zeng SONG Feng-bin ZHANG Zhi-ming YAN Jun XU Yan-li 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2020年第3期866-880,共15页
Certain agricultural management practices are known to affect the soil microbial community structure;however,knowledge of the response of the fungal community structure to the long-term continuous cropping and rotatio... Certain agricultural management practices are known to affect the soil microbial community structure;however,knowledge of the response of the fungal community structure to the long-term continuous cropping and rotation of soybean,maize and wheat in the same agroecosystem is limited.We assessed the fungal abundance,composition and diversity among soybean rotation,maize rotation and wheat rotation systems and among long-term continuous cropping systems of soybean,maize and wheat as the effect of crop types on fungal community structure.We compared these fungal parameters of same crop between long-term crop rotation and continuous cropping systems as the effect of cropping systems on fungal community structure.The fungal abundance and composition were measured by quantitative real-time PCR and Illumina MiSeq sequencing.The results revealed that long-term continuous soybean cropping increased the soil fungal abundance compared with soybean rotation,and the fungal abundance was decreased in long-term continuous maize cropping compared with maize rotation.The long-term continuous soybean cropping also exhibited increased soil fungal diversity.The variation in the fungal community structure among the three crops was greater than that between long-term continuous cropping and rotation cropping.Mortierella,Guehomyces and Alternaria were the most important contributors to the dissimilarity of the fungal communities between the continuous cropping and rotation cropping of soybean,maize and wheat.There were 11 potential pathogen and 11 potential biocontrol fungi identified,and the relative abundance of most of the potential pathogenic fungi increased during the long-term continuous cropping of all three crops.The relative abundance of most biocontrol fungi increased in long-term continuous soybean cropping but decreased in long-term continuous maize and wheat cropping.Our results indicate that the response of the soil fungal community structure to long-term continuous cropping varies based upon crop types. 展开更多
关键词 continuous cropping crop rotation fungal community structure Illumina MiSeq sequencing
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Bacterial Community Structure in a Mollisol Under Long-Term Natural Restoration, Cropping, and Bare Fallow History Estimated by PCR-DGGE 被引量:15
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作者 WANG Guang-Hua JIN Jian LIU Jun-Jie CHEN Xue-Li LIU Ju-Dong LIU Xiao-Bing 《Pedosphere》 SCIE CAS CSCD 2009年第2期156-165,共10页
Soil microbial biomass and community structures are commonly used as indicators for soil quality and fertility. A investigation was performed to study the effects of long-term natural restoration, cropping, and bare f... Soil microbial biomass and community structures are commonly used as indicators for soil quality and fertility. A investigation was performed to study the effects of long-term natural restoration, cropping, and bare fallow managements on the soil microbial biomass and bacterial community structures in depths of 0-10, 20 30, and 40-50 cm in a black soil (Mollisol). Microbial biomass was estimated from chloroform fumigation-extraction, and bacterial community structures were determined by analysis of 16S rDNA using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR- DGGE). Experimental results showed that microbial biomass significantly declined with soil depth in the managements of restoration and cropping, but not in the bare fallow. DGGE profiles indicated that the band number in top 0-10 cm soils was less than that in depth of 20-30 or 40-50 cm. These suggested that the microbial population was high but the bacterial community structure was simple in the topsoil. Cluster and principle component analysis based on DGGE banding patterns showed that the bacterial community structure was affected by soil depth more primarily than by managements, and the succession of bacterial community as increase of soil depth has a similar tendency in the three managements. Fourteen predominating DGGE bands were excised and sequenced, in which 6 bands were identified as the taxa of Verrueomicrobia, 2 bands as Actinobacteria, 2 bands as α-Proteobacteria, and the other 4 bands as 8-Proteobacteria, Aeidobacteria, Nitrospira, and unclassified bacteria. In addition, the sequences of 11 DGGE bands were closely related to uncultured bacteria. Thus, the bacterial community structure in black soil was stable, and the predominating bacterial groups were uncultured. 展开更多
关键词 bacterial community black soil denaturing gradient gel electrophoresis (DGGE) polymerase chain reaction (PCR) soil depth
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Effects of long-term straw incorporation on nematode community composition and metabolic footprint in a rice–wheat cropping system 被引量:3
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作者 CHEN Yun-feng XIA Xian-ge +4 位作者 HU Cheng LIU Dong-hai QIAO Yan LI Shuang-lai FAN Xian-peng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2021年第8期2265-2276,共12页
Soil nematode communities can provide valuable information about the structure and functions of soil food webs,and are sensitive to agricultural practices,including short-term straw incorporation.However,currently,suc... Soil nematode communities can provide valuable information about the structure and functions of soil food webs,and are sensitive to agricultural practices,including short-term straw incorporation.However,currently,such effects under longterm straw incorporation conditions at different fertility levels are largely unknown.Thus,we conducted a 13-year ongoing experiment to evaluate the effects of long-term straw incorporation on the structure and functions of the soil food web in low and high fertility soils through analyzing its effects on nematode communities,food web indices and metabolic footprints.Four treatments were included:straw removal(–S)under non-fertilized(–NPK)or fertilized(+NPK)conditions;and straw incorporation(+S)under–NPK or+NPK conditions.Soil samples from a 0–20 cm depth layer were collected when wheat and rice were harvested.Compared with straw removal,straw incorporation increased the abundances of total nematodes,bacterivores,plant-parasites and omnivores-predators,as well the relative abundances of omnivores-predators with increases of 73.06,89.29,95.31,238.98,and 114.61%in–NPK soils and 16.23,2.23,19.01,141.38,and 90.23%in+NPK soils,respectively.Regardless of sampling times and fertilization effects,straw incorporation increased the diversity and community stability of nematodes,as indicated by the Shannon-Weaver diversity index and maturity index.Enrichment and structure index did not show significant responses to straw incorporation,but a slight increase was observed in the structure index.The analysis of nematode metabolic footprints showed that straw incorporation increased the plant-parasite footprint and structure footprint by 97.27 and 305.39%in–NPK soils and by 11.29 and 149.56%in+NPK soils,but did not significantly influence enrichment,bacterivore and fungivore footprints.In conclusion,long-term straw incorporation,particularly under a low fertility level,favored the soil nematodes and regulated the soil food web mainly via a top-down effect. 展开更多
关键词 soil nematodes community composition metabolic footprint straw incorporation rice-wheat cropping system top-down effect
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The research of the community-home elderly long-term care service system 被引量:1
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作者 Qiang Zhu 《International English Education Research》 2015年第6期3-5,共3页
With the rapid development of the aging of the population, the demand of long-term care services in the elderly is growing. Because of family miniaturization, core, and currently limited social accumulation are diffic... With the rapid development of the aging of the population, the demand of long-term care services in the elderly is growing. Because of family miniaturization, core, and currently limited social accumulation are difficult to meet the demand of the elderly in long-term care.Community provides the elderly long-term care services, and provides the elderly all kinds of household helping services. They just make up for the inadequacy of the family and society.And how to make the community elderly long-term care services become more suitable for the needs of the elderly at home, provide better service for the elderly, are our current problems to be solved. 展开更多
关键词 community home endowment long-term care services Elderly care needs.
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A local fuzzy method based on “p-strong” community for detecting communities in networks 被引量:1
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作者 沈毅 任刚 +1 位作者 刘洋 徐家丽 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第6期589-595,共7页
In this paper,we propose a local fuzzy method based on the idea of "p-strong" community to detect the disjoint and overlapping communities in networks.In the method,a refined agglomeration rule is designed for agglo... In this paper,we propose a local fuzzy method based on the idea of "p-strong" community to detect the disjoint and overlapping communities in networks.In the method,a refined agglomeration rule is designed for agglomerating nodes into local communities,and the overlapping nodes are detected based on the idea of making each community strong.We propose a contribution coefficient bvcito measure the contribution of an overlapping node to each of its belonging communities,and the fuzzy coefficients of the overlapping node can be obtained by normalizing the bvci to all its belonging communities.The running time of our method is analyzed and varies linearly with network size.We investigate our method on the computergenerated networks and real networks.The testing results indicate that the accuracy of our method in detecting disjoint communities is higher than those of the existing local methods and our method is efficient for detecting the overlapping nodes with fuzzy coefficients.Furthermore,the local optimizing scheme used in our method allows us to partly solve the resolution problem of the global modularity. 展开更多
关键词 NETWORKS local fuzzy method overlapping communities fuzzy coefficients
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Changes in microbial community composition in the leaf litter of successional communities after volcanic eruptions of Mount Usu, northern Japan 被引量:2
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作者 Michiru OTAKI Fumiko TAKEUCHI Shiro TSUYUZAKI 《Journal of Mountain Science》 SCIE CSCD 2016年第9期1652-1662,共11页
Changes in the fungal and bacterial biomass and community structure in litter after the volcanic eruptions of Mount Usu, northern Japan were investigated using a chronosequence approach, which is widely used for analy... Changes in the fungal and bacterial biomass and community structure in litter after the volcanic eruptions of Mount Usu, northern Japan were investigated using a chronosequence approach, which is widely used for analyzing vegetation succession. The vegetation changed from bare ground (10 years after the eruptions) with little plant cover and poor soil to monotonic grassland dominated by Polygonum sachalinense with undeveloped soil (33 years) and then to deciduous broad-leaved forest dominated by Populus maximowiczii with diverse species composition and well-developed soil (100 years). At three chronosequential sites, we evaluated the compositions of phospholipid fatty acids (PLFAs), carbon (C) and nitrogen (N) contents and the isotope ratios of C (δ13C) and N (δ15N) in the litter of two dominant species, Polygonum sachalinense and Populus maximowiezii. The C/N ratio, δ13C and δ15N in the litter of these two species were higher in the forest than that in the bare ground and grassland. The PLFAs gradually increased from the bare ground to the forest, showing that microbial biomass increased with the development of the soil and/or vegetation. The fungi-to-bacteria ratio of PLFA was constant at 5.3 ± 1.4 in all three sites, suggesting that fungi were predominant. A canonical correspondence analysis suggested that the PLFA comoosition was related to the successional ages and the developing soil properties (P 〈 0.05, ANOSIM). The chrono- sequential analysis effectively detected the successional changes in both microbial and plant communities. 展开更多
关键词 Volcanic succession Fungi-to-bacteriaratio Litter decomposition Microbial community Phospholipid fatty acids (PLFAs) Primary succession
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Impact of Long-Term Fertilization on Cropland Soil Fauna Community at Loess Soil, Shannxi, China 被引量:1
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作者 LIN Ying-hua YANG Xue-yun +3 位作者 ZHANG Fu-dao GU Qiao-zhen SUN Ben-hua MA Lu-jun 《Agricultural Sciences in China》 CAS CSCD 2005年第12期924-930,共7页
The relationship between long-term fertilization and cropland network for soil fertility and fertilizers in Loess soil of Shannxi soil fauna was studied at the station's experiment research Provincefrom Jul. 2001 to ... The relationship between long-term fertilization and cropland network for soil fertility and fertilizers in Loess soil of Shannxi soil fauna was studied at the station's experiment research Provincefrom Jul. 2001 to Oct. 2002. Six types of long-term fertilizer were carried out for this study including non-fertilizer (CK), abandonment (ABAND), nitrogenous and phosphors and potassium fertilizers combined (NPK), straw and NPK (SNPK), organic material and NPK (MNPK) and 1.5 times MNPK (1.5MNPK). 72 soil samples were collected and 5 495 species of cropland soil fauna obtained by handsorting and Cobb methods at 4 times, belonging to 6 Phyla, 11 Classes, 22 Orders, 2 Superfamilies, 61 Families and 35 Genera. The result showed that different fertilizer had significantly impacted on the cropland soil fauna (F = 2.24, P〈0.007). The number of the cropland soil fauna was related to the soil physicochemical properties caused by long-term fertilization. The result by principal component analysis, focusing on the number of 15 key soil fauna species group's diversity, evenness of community and the total soil fauna individuals indicated that the effects of SNPK, NPK, MNPK and 1.5MNPK were significantly different from that of the cropland soil fauna, in which, SNPK and NPK had the positive effect on cropland soil fauna, and MNPK and 1.5 MNPK had the negative affect, others could not be explained. By principal component I, the synthetic effect of different fertilization on the total soil fauna individuals and the group was most significant, and the effect was little on evenness and diversity. By value of eigenvectors, the maximum one was 9.6248, and the minimum one was - 1.0904, that means the 6 types of fertilization did not affect evenly the cropland soil fauna. 展开更多
关键词 Cropland soil fauna community diversity Long term fertilization Principal component analysis Loss soi of Shannxi
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Clinical manifestations,diagnosis and long-term prognosis of adult autoimmune enteropathy:Experience from Peking Union Medical College Hospital 被引量:2
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作者 Mu-Han Li Ge-Chong Ruan +9 位作者 Wei-Xun Zhou Xiao-Qing Li Sheng-Yu Zhang Yang Chen Xiao-Yin Bai Hong Yang Yu-Jie Zhang Peng-Yu Zhao Ji Li Jing-Nan Li 《World Journal of Gastroenterology》 SCIE CAS 2024年第19期2523-2537,共15页
BACKGROUND Autoimmune enteropathy(AIE)is a rare disease whose diagnosis and long-term prognosis remain challenging,especially for adult AIE patients.AIM To improve overall understanding of this disease’s diagnosis an... BACKGROUND Autoimmune enteropathy(AIE)is a rare disease whose diagnosis and long-term prognosis remain challenging,especially for adult AIE patients.AIM To improve overall understanding of this disease’s diagnosis and prognosis.METHODS We retrospectively analyzed the clinical,endoscopic and histopathological characteristics and prognoses of 16 adult AIE patients in our tertiary medical center between 2011 and 2023,whose diagnosis was based on the 2007 diagnostic criteria.RESULTS Diarrhea in AIE patients was characterized by secretory diarrhea.The common endoscopic manifestations were edema,villous blunting and mucosal hyperemia in the duodenum and ileum.Villous blunting(100%),deep crypt lymphocytic infiltration(67%),apoptotic bodies(50%),and mild intraepithelial lymphocytosis(69%)were observed in the duodenal biopsies.Moreover,there were other remarkable abnormalities,including reduced or absent goblet cells(duodenum 94%,ileum 62%),reduced or absent Paneth cells(duodenum 94%,ileum 69%)and neutrophil infiltration(duodenum 100%,ileum 69%).Our patients also fulfilled the 2018 diagnostic criteria but did not match the 2022 diagnostic criteria due to undetectable anti-enterocyte antibodies.All patients received glucocorticoid therapy as the initial medication,of which 14/16 patients achieved a clinical response in 5(IQR:3-20)days.Immunosuppressants were administered to 9 patients with indications of steroid dependence(6/9),steroid refractory status(2/9),or intensified maintenance medication(1/9).During the median of 20.5 months of followup,2 patients died from multiple organ failure,and 1 was diagnosed with non-Hodgkin’s lymphoma.The cumulative relapse-free survival rates were 62.5%,55.6%and 37.0%at 6 months,12 months and 48 months,respectively.CONCLUSION Certain histopathological findings,including a decrease or disappearance of goblet and Paneth cells in intestinal biopsies,might be potential diagnostic criteria for adult AIE.The long-term prognosis is still unsatisfactory despite corticosteroid and immunosuppressant medications,which highlights the need for early diagnosis and novel medications. 展开更多
关键词 Autoimmune enteropathy Clinical manifestations Diagnostic criteria Pathological features long-term prognosis
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