To deal with the global and regional issues including food security, climate change, land degradation, biodiversity loss, water resource management, and ecosystem health, detailed accurate spatial soil information is ...To deal with the global and regional issues including food security, climate change, land degradation, biodiversity loss, water resource management, and ecosystem health, detailed accurate spatial soil information is urgently needed. This drives the worldwide development of digital soil mapping. In recent years, significant progresses have been made in different aspects of digital soil mapping. The main purpose of this paper is to provide a review for the major progresses of digital soil mapping in the last decade. First, we briefly described the rise of digital soil mapping and outlined important milestones and their influence, and main paradigms in digital soil mapping. Then, we reviewed the progresses in legacy soil data, environmental covariates, soil sampling, predictive models and the applications of digital soil mapping products. Finally, we summarized the main trends and future prospect as revealed by studies up to now. We concluded that although the digital soil mapping is now moving towards mature to meet various demands of soil information, challenges including new theories, methodologies and applications of digital soil mapping, especially for highly heterogeneous and human-affected environments, still exist and need to be addressed in the future.展开更多
The vertical distribution and migration of Cu,Zn,Pb,and Cd in two forest soil profiles near an industrial emission source were investigated using a high resolution sampling method together with reference element Ti.On...The vertical distribution and migration of Cu,Zn,Pb,and Cd in two forest soil profiles near an industrial emission source were investigated using a high resolution sampling method together with reference element Ti.One-meter soil profile was sectioned horizontally at 2 cm intervals in the first 40 cm,5 cm intervals in the next 40 cm,and 10 cm intervals in the last 20 cm.The migration distance and rate of heavy metals in the soil profiles were calculated according to their relative concentrations in the profiles,as calibrated by the reference element Ti.The enrichment of heavy metals appeared in the uppermost layer of the forest soil,and the soil heavy metal concentrations decreased down the profile until reaching their background values.The calculated average migration rates of Cd,Cu,Pb,and Zn were 0.70,0.33,0.37,and 0.76 cm year-1,respectively,which were comparable to other methods.A simulation model was proposed,which could well describe the distribution of Cu,Zn,Pb,and Cd in natural forest soils.展开更多
Environmental covariates are the basis of predictive soil mapping.Their selection determines the performance of soil mapping to a great extent,especially in cases where the number of soil samples is limited but soil s...Environmental covariates are the basis of predictive soil mapping.Their selection determines the performance of soil mapping to a great extent,especially in cases where the number of soil samples is limited but soil spatial heterogeneity is high.In this study,we proposed an integrated method to select environmental covariates for predictive soil depth mapping.First,candidate variables that may influence the development of soil depth were selected based on pedogenetic knowledge.Second,three conventional methods(Pearson correlation analysis(PsCA),generalized additive models(GAMs),and Random Forest(RF))were used to generate optimal combinations of environmental covariates.Finally,three optimal combinations were integrated to produce a final combination based on the importance and occurrence frequency of each environmental covariate.We tested this method for soil depth mapping in the upper reaches of the Heihe River Basin in Northwest China.A total of 129 soil sampling sites were collected using a representative sampling strategy,and RF and support vector machine(SVM)models were used to map soil depth.The results showed that compared to the set of environmental covariates selected by the three conventional selection methods,the set of environmental covariates selected by the proposed method achieved higher mapping accuracy.The combination from the proposed method obtained a root mean square error(RMSE)of 11.88 cm,which was 2.25–7.64 cm lower than the other methods,and an R^2 value of 0.76,which was 0.08–0.26 higher than the other methods.The results suggest that our method can be used as an alternative to the conventional methods for soil depth mapping and may also be effective for mapping other soil properties.展开更多
A SOTER-based automatic procedure for qualitative land evaluation is developed. This procedure was created in the automated land evaluation system (ALES). The objective was to design a procedure that allows for a quic...A SOTER-based automatic procedure for qualitative land evaluation is developed. This procedure was created in the automated land evaluation system (ALES). The objective was to design a procedure that allows for a quick separation of potentially suitable from non-suitable SOTER units for the intended land use, indicating constraints to different kinds of land use. Different kinds of land are unequal1y suited to various uses, land eva1uation is the assessment of the suitability of a tract of land for a specified kind of land use. In practice this implicates the comparison (matching) between the requirements of a specified land use and the properties of the land. Land evaluation concepts and definitions are treated in the paper. The ALES is a computer program that allows land evaluators to build their own knowledge-based system with which they can compute the physical and economical suitability of map units in accordance with FAO framework for land evaluation. The ALES program works with so-called decision trees, being hierarchical multiway keys in which the leaves are results (e.g., severity levels of land qualities), and the interior nodes of the tree are decision criteria (e.g., land characteristic values). These trees are traversed by the program to compute an evaluation using actual land data for each map unit. SOTAL is a SOTER-based qualitative model developed in ALES for physical land evaluation in which presently three land utilization types (LUTs) are distinguished, i.e., cultivated banana, coffee and rubber under different input and technological conditions. These LUTs are characterized by 11 landuse requirements and evaluated by matching the land use requirements with the corresponding land qualities. The paper elaborates on the criteria used in SOTAL for land quality assessment and how a final suitability rating is achieved on the basis of the rated land qualities. Results are visualized through G1S-generated maps as products in response to the specific information and data needs of decision and policy makers.展开更多
Soil depth is critical for eco-hydrological modeling,carbon storage calculation and land evaluation.However,its spatial variation is poorly understood and rarely mapped.With a limited number of sparse samples,how to p...Soil depth is critical for eco-hydrological modeling,carbon storage calculation and land evaluation.However,its spatial variation is poorly understood and rarely mapped.With a limited number of sparse samples,how to predict soil depth in a large area of complex landscapes is still an issue.This study constructed an ensemble machine learning model,i.e.,quantile regression forest,to quantify the relationship between soil depth and environmental conditions.The model was then combined with a rich set of environmental covariates to predict spatial variation of soil depth and straightforwardly estimate the associated predictive uncertainty in the 140000 km^(2)Heihe River basin of northwestern China.A total of 275 soil depth observation points and 26 covariates were used.The results showed a model predictive accuracy with coefficient of determination(R)of 0.587 and root mean square error(RMSE)of 2.98 cm(square root scale),i.e.,almost 60% of soil depth variation explained.The resulting soil depth map clearly exhibited regional patterns as well as local details.Relatively deep soils occurred in low lying landscape positions such as valley bottoms and plains while shallow soils occurred in high and steep landscape positions such as hillslopes,ridges and terraces.The oases had much deeper soils than outside semi-desert areas,the middle of an alluvial plain had deeper soils than its margins,and the middle of a lacustrine plain had shallower soils than its margins.Large predictive uncertainty mainly occurred in areas with a lack of soil survey points.Both pedogenic and geomorphic processes contributed to the shaping of soil depth pattern of this basin but the latter was dominant.This findings may be applicable to other similar basins in cold and arid regions around the world.展开更多
OBJECTIVE GubenyiliuⅡ(GYⅡ),a traditional Chinese medicine(TCM)formula used in our hospital,has shown beneficial effects in cancer patients.In this study,we investigated the molecular mechanisms underlying the benefi...OBJECTIVE GubenyiliuⅡ(GYⅡ),a traditional Chinese medicine(TCM)formula used in our hospital,has shown beneficial effects in cancer patients.In this study,we investigated the molecular mechanisms underlying the beneficial effects of GYⅡon murine breast cancer models.METHODS Inhibition of tumor growth and metastasis was evaluated by assessment of tumor weight and analysis of bioluminescent signal after a homograft inoculation.Viability of cultured breast cancer cells was determined using MTT assay andreal-time cell analysis(RTCA).Cell migratory ability was evaluated by Transwell?assay and wound healing assay.Subsequently,the potential anti-tumor and anti-metastatic mechanism was investigated by Western blotting and Immunohistochemistry.RESULTS GYⅡshowed significant inhibitory effects on tumor growth and metastasis in the murine breast cancer model.And GYⅡsuppressed theproliferation of 4T1 and MCF-7 cells in a dose-dependent manner.A better inhibitory effect on 4T1 cells proliferation and migration was found in sub-fractions(SF)of GYⅡ.Moreover,heparanase expression and degree of angiogenesis were reduced in tumor tissues.Western blotting analysis showed decreased expression of heparanase and growth factors in the cells treated with GYⅡand its sub-fractions(SF2 and SF3),there by a reduction in phosphorylation of ERK and AKT.CONCLUSION GYⅡexerts anti-tumor growth and anti-metastatic effects on murine breast cancer model.Sub-fractions 2 and 3 exhibits higher potency of the anti-tumor activity that is,at least partly,associated with decreased heparanase and growth factor sexpression,which subsequently sup-pressed activation of ERK and AKT pathways.展开更多
Pedogenetic soil horizons are one of the fundamental building blocks of modern soil classification; however, in soils of urban areas which are often strongly disturbed by human activities, horizons are difficult to di...Pedogenetic soil horizons are one of the fundamental building blocks of modern soil classification; however, in soils of urban areas which are often strongly disturbed by human activities, horizons are difficult to distinguish but substitutive morphological layers may be identified. To identify the characteristic soil layers in an urban environment, 224 soil layers of 36 in-situ pedons were examined and described in urban and suburban Nanjing, and 27 variables were extracted for multivariate analysis. Three groups and six subdivisions were identified by TwoStep cluster analysis combined with hierarchical cluster analysis based on factor scores. Soil forming factors and soil forming processes could be interpreted from the principal component analysis （PCA） of variables, cluster analysis of soil layers, and discriminant analysis of soil layer groups and their subdivisions. Parent materials, moisture regimes, organic matter accumulation, and especially nutrient accumulation were the main causes of characteristic soil layer formations. The numerical approaches used in this study were useful tools for characteristic soil layer identification of urban soils.展开更多
OBJECTIVE To investigate the inhibitory effects of Spatholobus Suberectus Column Extract(SSCE)on estrogen receptor positive(ER+)breast cancer cel MCF-7and its possible molecular mechanism.METHODS MCF-7cells were cultu...OBJECTIVE To investigate the inhibitory effects of Spatholobus Suberectus Column Extract(SSCE)on estrogen receptor positive(ER+)breast cancer cel MCF-7and its possible molecular mechanism.METHODS MCF-7cells were cultured without estrogen and with 17-β-estrogen(10-8mol·L-1),respectively,then treated with SSCE(0,40,80,160,320μg·m L-1).MTT assay was employed to evaluate cell viability.Flow cytometry assays were performed to underlying apoptosis and detecting cel cycle of MCF-7 cells treated with SSCE(0,80,160,320μg·mL-1).Wound healing assays was conducted to detect the migration ability.Dual luciferase reporter system was used to detect the activity of p-ERα,p-ERβpresented in intra-nuclear estrogen response element(ERE).Western blotting assay was employed to identify the expression of protein such as Bax,Bcl-2,p-ERα,p-ERβ,ERK1/2,p-ERK1/2,AKT,p-AKT,m TOR,p-m TOR,PI3K,p-PI3K.RESULTS It showed that SSCE(80,160and 320μg·mL-1)significantly decreased the viability of MCF-7.SSCE also triggered apoptosis,arrested cell cycle at G0/G1phase,inhibited migration.Dual luciferase reporter system showed that SSCE suppressed intra-nuclear p-ER activity,Western blotting analysis confirmed that SSCE did repress the expression of phosphorylated-ER alpha(p-ERα),ERK1/2,p-ERK1/2,AKT,p-AKT,pmT OR,PI3K,p-PI3K,which indicate that SSCE suppress MAPK PI3K/AKT signal pathway.CONCLUSION Our result showed that SSCE cause ER+MCF-7 cells apoptosis,G0/G1phase arresting,migration decreasing,via hypo-active of ER,suppress MAPK PI3K/AKT pathway.展开更多
Due to continuous decreases in arable land area and continuous population increases,Chinese soil scientists face great challenges in meeting food demands,mitigating adverse environmental impacts,and sustaining or enha...Due to continuous decreases in arable land area and continuous population increases,Chinese soil scientists face great challenges in meeting food demands,mitigating adverse environmental impacts,and sustaining or enhancing soil productivity under intensive agriculture.With the aim of promoting the application of soil science knowledge,this paper reviews the achievements of Chinese scientists in soil resource use and management,soil fertility,global change mitigation and soil biology over the last 30 years.During this period,soil resource science has provided essential support for the use and exploitation of Chinese soil resources,and has itself developed through introduction of new theories such as Soil Taxonomy and new technologies such as remote sensing.Soil fertility science has contributed to the alleviation and elimination of impeding physical and chemical factors that constrain availability of essential nutrients and water in soils,the understanding of nutrient cycling in agroecosystems,and the increase in nutrient use efficiency for sustainable crop production.Chinese soil scientists have contributed to the understanding of the cropland's role in global change,particularly to the understanding of methane and nitrous oxide emission from rice fields and the effect of elevated carbon dioxide and ozone on rice-wheat system.Soil biology research has progressed in biological N fixation,distribution of fauna in Chinese soils,and bioremediation of polluted soils.A new generation of soil scientists has arisen in the last three decades.The gaps between research and application in these soil science fields are also discussed.展开更多
The use of landscape covariates to variability of soil properties in similar estimate soil properties is not suitable topographic and vegetation conditions. for the areas of low relief due to the high A new method wa...The use of landscape covariates to variability of soil properties in similar estimate soil properties is not suitable topographic and vegetation conditions. for the areas of low relief due to the high A new method was implemented to map regional soil texture （in terms of sand, silt and clay contents） by hypothesizing that the change in the land surface diurnal temperature difference （DTD） is related to soil texture in case of a relatively homogeneous rainfall input. To examine this hypothesis, the DTDs from moderate resolution imagine spectroradiometer （MODIS） during a selected time period, i.e., after a heavy rainfall between autumn harvest and autumn sowing, were classified using fuzzy-c-means （FCM） clustering. Six classes were generated, and for each class, the sand （〉 0.05 mm）, silt （0.002-0.05 mm） and clay （〈 0.002 mm） contents at the location of maximum membership value were considered as the typical values of that class. A weighted average model was then used to digitally map soil texture. The results showed that the predicted map quite accurately reflected the regional soil variation. A validation dataset produced estimates of error for the predicted maps of sand, silt and clay contents at root mean of squared error values of 8.4%, 7.8% and 2.3%, respectively, which is satisfactory in a practical context. This study thus provided a methodology that can help improve the accuracy and efficiency of soil texture mapping in plain areas using easily available data sources.展开更多
Six typical red clay profiles were sampled from Tangxi （TX）, Langyaz （LYZ）, South Shangshanwen （SSW）, Xianqiao （XQ）, Qijian （Q J） and Huhaitang （HHT） of Jinhua-Quzhou Basin, Zhejiang Province of China to e...Six typical red clay profiles were sampled from Tangxi （TX）, Langyaz （LYZ）, South Shangshanwen （SSW）, Xianqiao （XQ）, Qijian （Q J） and Huhaitang （HHT） of Jinhua-Quzhou Basin, Zhejiang Province of China to evaluate the characteristics of grain size composition, distribution and parameters of red clays and to reveal the origin of red clays and interpret possible implications for paleoclimate in subtropical China. The results showed that red clays in TX, LYZ and SSW were fine and uniform, with no 〉 2 mm gravels and little 〉 63μm fraction. They had a high content of 10-50 μm fraction, so-called ＂basic dust fraction＂, and showed unimodal distributions, which were very comparable to those of the Xiashu Loess in southeastern China and the loess in North China. All these features reflected marked aeolian characteristics of the red clays in these areas. Red clays in XQ and QJ were much coarser than those in TjjX, LYZ and SSW, with high contents of 〉 63μm fraction and even containing 〉 2 mm gravels in some layers. The grain size distribution patterns showed significantly progressive trends from the lower profile to the upmost layer and could not be compared with those of the loess in North China or the Xiashu Loess, implying they might be derived from underlying parent rocks and had some inherited properties from bedrock. Red clays in HHT had high contents of 〉 63μm fraetion and contain many 〉 2 mm gravels in each layer. The grain size frequency curves showed multiple-peaks and some abrupt variations were also observed on the profile, revealing its alluvial or diluvial origin in HHT. The multiple origins of red clays reflected the diversity and complexity of the Quaternary environment in South China. It can be concluded that grain size is an effective proxy indicator for the origin of most deposits.展开更多
基金supported by the National Natural Science Foundation of China (91325301, 41571130051)
文摘To deal with the global and regional issues including food security, climate change, land degradation, biodiversity loss, water resource management, and ecosystem health, detailed accurate spatial soil information is urgently needed. This drives the worldwide development of digital soil mapping. In recent years, significant progresses have been made in different aspects of digital soil mapping. The main purpose of this paper is to provide a review for the major progresses of digital soil mapping in the last decade. First, we briefly described the rise of digital soil mapping and outlined important milestones and their influence, and main paradigms in digital soil mapping. Then, we reviewed the progresses in legacy soil data, environmental covariates, soil sampling, predictive models and the applications of digital soil mapping products. Finally, we summarized the main trends and future prospect as revealed by studies up to now. We concluded that although the digital soil mapping is now moving towards mature to meet various demands of soil information, challenges including new theories, methodologies and applications of digital soil mapping, especially for highly heterogeneous and human-affected environments, still exist and need to be addressed in the future.
基金the National Natural Science Foundation of China (No40625001)the Knowledge Innovation Pro-gram of the Chinese Academy of Sciences (NoKZCX2-YW-409)the Jiangsu Provincial Natural Science Foundation of China (NoBK2004167)
文摘The vertical distribution and migration of Cu,Zn,Pb,and Cd in two forest soil profiles near an industrial emission source were investigated using a high resolution sampling method together with reference element Ti.One-meter soil profile was sectioned horizontally at 2 cm intervals in the first 40 cm,5 cm intervals in the next 40 cm,and 10 cm intervals in the last 20 cm.The migration distance and rate of heavy metals in the soil profiles were calculated according to their relative concentrations in the profiles,as calibrated by the reference element Ti.The enrichment of heavy metals appeared in the uppermost layer of the forest soil,and the soil heavy metal concentrations decreased down the profile until reaching their background values.The calculated average migration rates of Cd,Cu,Pb,and Zn were 0.70,0.33,0.37,and 0.76 cm year-1,respectively,which were comparable to other methods.A simulation model was proposed,which could well describe the distribution of Cu,Zn,Pb,and Cd in natural forest soils.
基金supported financially by the National Natural Science Foundation of China (91325301, 41571212 and 41137224)the Project of "One-Three-Five" Strategic Planning & Frontier Sciences of the Institute of Soil Science, Chinese Academy of Sciences (ISSASIP1622)the National Key Basic Research Special Foundation of China (2012FY112100)
文摘Environmental covariates are the basis of predictive soil mapping.Their selection determines the performance of soil mapping to a great extent,especially in cases where the number of soil samples is limited but soil spatial heterogeneity is high.In this study,we proposed an integrated method to select environmental covariates for predictive soil depth mapping.First,candidate variables that may influence the development of soil depth were selected based on pedogenetic knowledge.Second,three conventional methods(Pearson correlation analysis(PsCA),generalized additive models(GAMs),and Random Forest(RF))were used to generate optimal combinations of environmental covariates.Finally,three optimal combinations were integrated to produce a final combination based on the importance and occurrence frequency of each environmental covariate.We tested this method for soil depth mapping in the upper reaches of the Heihe River Basin in Northwest China.A total of 129 soil sampling sites were collected using a representative sampling strategy,and RF and support vector machine(SVM)models were used to map soil depth.The results showed that compared to the set of environmental covariates selected by the three conventional selection methods,the set of environmental covariates selected by the proposed method achieved higher mapping accuracy.The combination from the proposed method obtained a root mean square error(RMSE)of 11.88 cm,which was 2.25–7.64 cm lower than the other methods,and an R^2 value of 0.76,which was 0.08–0.26 higher than the other methods.The results suggest that our method can be used as an alternative to the conventional methods for soil depth mapping and may also be effective for mapping other soil properties.
基金UNDP Project CPR/96/105 "Sustainable Land Management for Agricultural Production in Hainan Province"
文摘A SOTER-based automatic procedure for qualitative land evaluation is developed. This procedure was created in the automated land evaluation system (ALES). The objective was to design a procedure that allows for a quick separation of potentially suitable from non-suitable SOTER units for the intended land use, indicating constraints to different kinds of land use. Different kinds of land are unequal1y suited to various uses, land eva1uation is the assessment of the suitability of a tract of land for a specified kind of land use. In practice this implicates the comparison (matching) between the requirements of a specified land use and the properties of the land. Land evaluation concepts and definitions are treated in the paper. The ALES is a computer program that allows land evaluators to build their own knowledge-based system with which they can compute the physical and economical suitability of map units in accordance with FAO framework for land evaluation. The ALES program works with so-called decision trees, being hierarchical multiway keys in which the leaves are results (e.g., severity levels of land qualities), and the interior nodes of the tree are decision criteria (e.g., land characteristic values). These trees are traversed by the program to compute an evaluation using actual land data for each map unit. SOTAL is a SOTER-based qualitative model developed in ALES for physical land evaluation in which presently three land utilization types (LUTs) are distinguished, i.e., cultivated banana, coffee and rubber under different input and technological conditions. These LUTs are characterized by 11 landuse requirements and evaluated by matching the land use requirements with the corresponding land qualities. The paper elaborates on the criteria used in SOTAL for land quality assessment and how a final suitability rating is achieved on the basis of the rated land qualities. Results are visualized through G1S-generated maps as products in response to the specific information and data needs of decision and policy makers.
基金supported by the National Natural Science Foundation of China(41130530,91325301 and 42071072)。
文摘Soil depth is critical for eco-hydrological modeling,carbon storage calculation and land evaluation.However,its spatial variation is poorly understood and rarely mapped.With a limited number of sparse samples,how to predict soil depth in a large area of complex landscapes is still an issue.This study constructed an ensemble machine learning model,i.e.,quantile regression forest,to quantify the relationship between soil depth and environmental conditions.The model was then combined with a rich set of environmental covariates to predict spatial variation of soil depth and straightforwardly estimate the associated predictive uncertainty in the 140000 km^(2)Heihe River basin of northwestern China.A total of 275 soil depth observation points and 26 covariates were used.The results showed a model predictive accuracy with coefficient of determination(R)of 0.587 and root mean square error(RMSE)of 2.98 cm(square root scale),i.e.,almost 60% of soil depth variation explained.The resulting soil depth map clearly exhibited regional patterns as well as local details.Relatively deep soils occurred in low lying landscape positions such as valley bottoms and plains while shallow soils occurred in high and steep landscape positions such as hillslopes,ridges and terraces.The oases had much deeper soils than outside semi-desert areas,the middle of an alluvial plain had deeper soils than its margins,and the middle of a lacustrine plain had shallower soils than its margins.Large predictive uncertainty mainly occurred in areas with a lack of soil survey points.Both pedogenic and geomorphic processes contributed to the shaping of soil depth pattern of this basin but the latter was dominant.This findings may be applicable to other similar basins in cold and arid regions around the world.
基金The project supported by National Natural Science Foundation of China(81202840,81373815)Specialized Research Fund for the Doctoral Program of Higher Education of China(20131107110014)+1 种基金Beijing Natural Science Foundation(7162084)Swedish Cancer Foundation(150815)
文摘OBJECTIVE GubenyiliuⅡ(GYⅡ),a traditional Chinese medicine(TCM)formula used in our hospital,has shown beneficial effects in cancer patients.In this study,we investigated the molecular mechanisms underlying the beneficial effects of GYⅡon murine breast cancer models.METHODS Inhibition of tumor growth and metastasis was evaluated by assessment of tumor weight and analysis of bioluminescent signal after a homograft inoculation.Viability of cultured breast cancer cells was determined using MTT assay andreal-time cell analysis(RTCA).Cell migratory ability was evaluated by Transwell?assay and wound healing assay.Subsequently,the potential anti-tumor and anti-metastatic mechanism was investigated by Western blotting and Immunohistochemistry.RESULTS GYⅡshowed significant inhibitory effects on tumor growth and metastasis in the murine breast cancer model.And GYⅡsuppressed theproliferation of 4T1 and MCF-7 cells in a dose-dependent manner.A better inhibitory effect on 4T1 cells proliferation and migration was found in sub-fractions(SF)of GYⅡ.Moreover,heparanase expression and degree of angiogenesis were reduced in tumor tissues.Western blotting analysis showed decreased expression of heparanase and growth factors in the cells treated with GYⅡand its sub-fractions(SF2 and SF3),there by a reduction in phosphorylation of ERK and AKT.CONCLUSION GYⅡexerts anti-tumor growth and anti-metastatic effects on murine breast cancer model.Sub-fractions 2 and 3 exhibits higher potency of the anti-tumor activity that is,at least partly,associated with decreased heparanase and growth factor sexpression,which subsequently sup-pressed activation of ERK and AKT pathways.
基金the National Natural Science Foundation of China (No40625001)the Knowledge Innovation Program of the Chinese Academy of Sciences (NoKZCX2-YW-409)
文摘Pedogenetic soil horizons are one of the fundamental building blocks of modern soil classification; however, in soils of urban areas which are often strongly disturbed by human activities, horizons are difficult to distinguish but substitutive morphological layers may be identified. To identify the characteristic soil layers in an urban environment, 224 soil layers of 36 in-situ pedons were examined and described in urban and suburban Nanjing, and 27 variables were extracted for multivariate analysis. Three groups and six subdivisions were identified by TwoStep cluster analysis combined with hierarchical cluster analysis based on factor scores. Soil forming factors and soil forming processes could be interpreted from the principal component analysis （PCA） of variables, cluster analysis of soil layers, and discriminant analysis of soil layer groups and their subdivisions. Parent materials, moisture regimes, organic matter accumulation, and especially nutrient accumulation were the main causes of characteristic soil layer formations. The numerical approaches used in this study were useful tools for characteristic soil layer identification of urban soils.
基金The project supported by Beijing Natural Science Foundation(7122083)Beijing Science and Technology Projec(tD161100005116005)
文摘OBJECTIVE To investigate the inhibitory effects of Spatholobus Suberectus Column Extract(SSCE)on estrogen receptor positive(ER+)breast cancer cel MCF-7and its possible molecular mechanism.METHODS MCF-7cells were cultured without estrogen and with 17-β-estrogen(10-8mol·L-1),respectively,then treated with SSCE(0,40,80,160,320μg·m L-1).MTT assay was employed to evaluate cell viability.Flow cytometry assays were performed to underlying apoptosis and detecting cel cycle of MCF-7 cells treated with SSCE(0,80,160,320μg·mL-1).Wound healing assays was conducted to detect the migration ability.Dual luciferase reporter system was used to detect the activity of p-ERα,p-ERβpresented in intra-nuclear estrogen response element(ERE).Western blotting assay was employed to identify the expression of protein such as Bax,Bcl-2,p-ERα,p-ERβ,ERK1/2,p-ERK1/2,AKT,p-AKT,m TOR,p-m TOR,PI3K,p-PI3K.RESULTS It showed that SSCE(80,160and 320μg·mL-1)significantly decreased the viability of MCF-7.SSCE also triggered apoptosis,arrested cell cycle at G0/G1phase,inhibited migration.Dual luciferase reporter system showed that SSCE suppressed intra-nuclear p-ER activity,Western blotting analysis confirmed that SSCE did repress the expression of phosphorylated-ER alpha(p-ERα),ERK1/2,p-ERK1/2,AKT,p-AKT,pmT OR,PI3K,p-PI3K,which indicate that SSCE suppress MAPK PI3K/AKT signal pathway.CONCLUSION Our result showed that SSCE cause ER+MCF-7 cells apoptosis,G0/G1phase arresting,migration decreasing,via hypo-active of ER,suppress MAPK PI3K/AKT pathway.
文摘Due to continuous decreases in arable land area and continuous population increases,Chinese soil scientists face great challenges in meeting food demands,mitigating adverse environmental impacts,and sustaining or enhancing soil productivity under intensive agriculture.With the aim of promoting the application of soil science knowledge,this paper reviews the achievements of Chinese scientists in soil resource use and management,soil fertility,global change mitigation and soil biology over the last 30 years.During this period,soil resource science has provided essential support for the use and exploitation of Chinese soil resources,and has itself developed through introduction of new theories such as Soil Taxonomy and new technologies such as remote sensing.Soil fertility science has contributed to the alleviation and elimination of impeding physical and chemical factors that constrain availability of essential nutrients and water in soils,the understanding of nutrient cycling in agroecosystems,and the increase in nutrient use efficiency for sustainable crop production.Chinese soil scientists have contributed to the understanding of the cropland's role in global change,particularly to the understanding of methane and nitrous oxide emission from rice fields and the effect of elevated carbon dioxide and ozone on rice-wheat system.Soil biology research has progressed in biological N fixation,distribution of fauna in Chinese soils,and bioremediation of polluted soils.A new generation of soil scientists has arisen in the last three decades.The gaps between research and application in these soil science fields are also discussed.
基金Supported by the Basic Research Program of Jiangsu Province,China (No. BK2008058)the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-409)
文摘The use of landscape covariates to variability of soil properties in similar estimate soil properties is not suitable topographic and vegetation conditions. for the areas of low relief due to the high A new method was implemented to map regional soil texture （in terms of sand, silt and clay contents） by hypothesizing that the change in the land surface diurnal temperature difference （DTD） is related to soil texture in case of a relatively homogeneous rainfall input. To examine this hypothesis, the DTDs from moderate resolution imagine spectroradiometer （MODIS） during a selected time period, i.e., after a heavy rainfall between autumn harvest and autumn sowing, were classified using fuzzy-c-means （FCM） clustering. Six classes were generated, and for each class, the sand （〉 0.05 mm）, silt （0.002-0.05 mm） and clay （〈 0.002 mm） contents at the location of maximum membership value were considered as the typical values of that class. A weighted average model was then used to digitally map soil texture. The results showed that the predicted map quite accurately reflected the regional soil variation. A validation dataset produced estimates of error for the predicted maps of sand, silt and clay contents at root mean of squared error values of 8.4%, 7.8% and 2.3%, respectively, which is satisfactory in a practical context. This study thus provided a methodology that can help improve the accuracy and efficiency of soil texture mapping in plain areas using easily available data sources.
基金Supported by the National Natural Science Foundation of China(Nos.41071002 and 41071142)the Zhejiang Provincial Natural Science Foundation of China(Nos.LQ13D010002 and X506313)the Knowledge Innovation Program of the Chinese Academy of Sciences(Nos.KZCX2-YW-409 and KZCX2-EW-405-1)
文摘Six typical red clay profiles were sampled from Tangxi （TX）, Langyaz （LYZ）, South Shangshanwen （SSW）, Xianqiao （XQ）, Qijian （Q J） and Huhaitang （HHT） of Jinhua-Quzhou Basin, Zhejiang Province of China to evaluate the characteristics of grain size composition, distribution and parameters of red clays and to reveal the origin of red clays and interpret possible implications for paleoclimate in subtropical China. The results showed that red clays in TX, LYZ and SSW were fine and uniform, with no 〉 2 mm gravels and little 〉 63μm fraction. They had a high content of 10-50 μm fraction, so-called ＂basic dust fraction＂, and showed unimodal distributions, which were very comparable to those of the Xiashu Loess in southeastern China and the loess in North China. All these features reflected marked aeolian characteristics of the red clays in these areas. Red clays in XQ and QJ were much coarser than those in TjjX, LYZ and SSW, with high contents of 〉 63μm fraction and even containing 〉 2 mm gravels in some layers. The grain size distribution patterns showed significantly progressive trends from the lower profile to the upmost layer and could not be compared with those of the loess in North China or the Xiashu Loess, implying they might be derived from underlying parent rocks and had some inherited properties from bedrock. Red clays in HHT had high contents of 〉 63μm fraetion and contain many 〉 2 mm gravels in each layer. The grain size frequency curves showed multiple-peaks and some abrupt variations were also observed on the profile, revealing its alluvial or diluvial origin in HHT. The multiple origins of red clays reflected the diversity and complexity of the Quaternary environment in South China. It can be concluded that grain size is an effective proxy indicator for the origin of most deposits.
