The following investigations were conducted to evaluate grassy strips of different age for organic arable fields. From September 2009 to October 2010, adult ground beetles were sampled by pitfall traps in three grassy...The following investigations were conducted to evaluate grassy strips of different age for organic arable fields. From September 2009 to October 2010, adult ground beetles were sampled by pitfall traps in three grassy strips (2, 4, and 9 years old), their adjacent cropping areas, their field edges, and a control field (age 0) in Schleswig-Holstein, northern Germany. Carabid assemblages were similar among the fields, strips and edges. Grassy strips and edges had higher species richness and lower activity density than the control field. Activity density increased with increasing distance from the field edge in grassy strips and in the adjacent fields. In cropping areas, species richness andShannon’s H increased with increasing age of strips, whereas evenness and activity density decreased with increasing distance from the field edges. Compared to carnivorous and phytophagous carbides, omnivorous species were affected less by age of strips and distance from field margins. In the strips, species richness of the dominant species increased with age and decreased with distance, but the effect of strip age on species richness was still found in more than150 mfrom the margin. A positive effect of the age of grassy strips on species richness was found for cropping fields, grassy strips and field edges. Old grassy strips also exerted greater influence on the species richness and biodiversity of the adjacent arable fields than the younger strips.展开更多
The properties of grassy edge-localized modes(ELMs)in EAST in the favorable and unfavorable Btare statistically studied.Statistical analysis indicates that there is no systematical difference in the frequencies of gra...The properties of grassy edge-localized modes(ELMs)in EAST in the favorable and unfavorable Btare statistically studied.Statistical analysis indicates that there is no systematical difference in the frequencies of grassy ELMs under the two different magnetic configurations in the similar parameter spaces.The high-frequency grassy ELM(fELM>1 k Hz)in unfavorable Bt is dependent on the high poloidal betaβpand high triangularityδu,while the high-frequency grassy ELM(fELM>1k Hz)in favorable Btappears to rely on the high plasma density.A frequently occurring phenomenon in favorable Btdefined as‘clustered ELM’seems to be the most evident difference in ELM behavior between favorable and unfavorable Bt.Statistical analysis shows that larger plasma-wall outer gap,longer plasma elongation,lower low-hybrid wave heating power and electron cyclotron resonance heating power favor the occurrence of clustered grassy ELMs.Further studies indicate that the generation of clustered grassy ELMs could be correlated with the lower electron temperature in the bulk plasma.展开更多
The aim of this study was to analyze the effects of mechanical perforation of a golf course grassy sward, subject to maintenance machinery traffic and golf players trampling on its compaction and density. The evolutio...The aim of this study was to analyze the effects of mechanical perforation of a golf course grassy sward, subject to maintenance machinery traffic and golf players trampling on its compaction and density. The evolution of soil compaction state after aeration was also conducted in four stages of measurement. This operation aims to improve the structure and soil texture, which is also called ＂perforation＂ or ＂coring＂. The taken cores leaving on the soil holes of adjustable depth and density （350 holes/mE） are made with an aerator machine called Vertidrain. Soil resistance to penetration and density were determined at the initial state before aeration as well as 10, 20, and 30 days after aeration. Compared to the initial state, the results show that mechanical aeration greatly affects the grassy sward ground by reducing its resistance to penetration as 35% and 43% decrease in penetration resistance were noticed at 5 cm depth l0 and 20 days after aeration, respectively. Also, resistance to penetration decreased by 41% and 48% at 15 cm depth during the same two periods of time with a relatively constant moisture content. However, soil resistance to penetration at 5 and 15 cm depths only decreased by 21% and 26%, respectively. Regarding the soil density measured after aeration, a significant improvement at the 1% level with the method of variance analysis was observed compared to that at the initial state （e.g. 1.33 g·cm^-3） Indeed, the density was 1.29, 1.26 and 1.30 gcm^-3 10, 20 and 30 days after aeration, respectively.展开更多
In a golf course located at El Kantaoui, Sousse, Tunisia, this study was carried out over a sandy soil grassy sward to investigate the effects of mechanical aeration （perforation of the sward with an aerators machine...In a golf course located at El Kantaoui, Sousse, Tunisia, this study was carried out over a sandy soil grassy sward to investigate the effects of mechanical aeration （perforation of the sward with an aerators machine called ＂Vertidrain＂） on its compaction and hydraulic conductivity. For this purpose, many soil cores were extracted using a 1.6 e.g. m effective width Verti-Drain aerator equipped with hollow spades spaced 65 e.g. mm apart. Aeration was performed at a rate of 350 holes/m2. Soil resistance to penetration and permeability were determined at the initial state before aeration as well as 10, 20, and 30 days after aeration. Compared to the initial state, the results showed that mechanical aeration greatly affects the grassy sward ground by reducing its resistance to penetration as 35% and 43% decrease in penetration resistance were noticed at 5 e.g. cm depth 10 and 20 days after aeration, respectively. Also, resistance to penetration decreased by 41% and 48% at 15 e.g. cm depth during the same two periods of time with a relatively constant moisture content. However, soil resistance to penetration at 5 and 15 e.g. cm depths only decreased by 21% and 26%, respectively. Regarding the soil hydraulic conductivity measured after aeration, a significant improvement at the 1% level with the method of variance analysis, was observed compared to that at the initial state （4.9 e.g. cm hl）. Indeed, the hydraulic conductivity was 12.5, 13, and 14.1 e.g. cm h-1 10, 20, and 30 days after aeration, respectively.展开更多
Change silt charge of water in the rivers can negatively be reflected in throughput the rivers beds,stability of coast,change of river structures,disappearance of boggy places,etc.In work questions of variabilit...Change silt charge of water in the rivers can negatively be reflected in throughput the rivers beds,stability of coast,change of river structures,disappearance of boggy places,etc.In work questions of variability silt charge waters in the river Sluch in time and on length of the river are considered.It is revealed that in time average and maximal silt charge waters decrease.While on length of the river change silt charge waters is shown not precisely,similar on some increase silt charge waters to a mouth of the river.The researches led by the factorial analysis and graphic-analytical method on the basis of long-term materials of measurement of charges of water have shown that,on a part of posts average depth of water in the river grows,and on others-cyclically changes with the general tendency to reduction.Average speed in them,accordingly,falls and grows.Stratification of interrelations of a silt charge with other factors on years is observed.The reasons of reduction of a silt charge are:1)agrarian and forest meliorative actions on a catchments of the river,hydraulic engineering construction;2)grassy bed of the river;3)change of a climate that promotes growth of temperature of a surface of soils and grassy bed of the river.In developed natural-climatic conditions expediently application on reservoirs of the antierosion organization of territory of the land tenure including agrarian-forests-meliorative actions that will allow to adjust outflow of a moisture from reservoirs to lower warming up of a surface of the soils,to provide against a high water protection and it will favorably be reflected in manufacture of agricultural production.展开更多
Chromium hexacyanoferrate (CrHCF) modified grassy carbon electrode (GC) in different electrolytes was studied by cyclic voltammetry and in situ FTIR spectroelectrochemistry. The results indicate that the behavior of C...Chromium hexacyanoferrate (CrHCF) modified grassy carbon electrode (GC) in different electrolytes was studied by cyclic voltammetry and in situ FTIR spectroelectrochemistry. The results indicate that the behavior of CrHCF firm can be understood in term of two structures: Cr1/3Cr(III)Fe(II)(CN), and MCr(III)Fe(II)(CN)(6). Besides,the film exists in amorphous state: the outer layer is porous film, while the inner layer is relatively compact. According to the electrochemical reaction of CrHCF, the lattice can contract and expand with the cations' diffusion.展开更多
The ubiquitin-proteasome system(UPS)is an important post-translational regulatory mechanism that controls many cellular functions in eukaryotes.Here,we show that stable expression of P3 protein encoded by Rice grassy ...The ubiquitin-proteasome system(UPS)is an important post-translational regulatory mechanism that controls many cellular functions in eukaryotes.Here,we show that stable expression of P3 protein encoded by Rice grassy stunt virus(RGSV),a negative-strand RNA virus in the Bunyavirales,causes developmental abnormities similar to the disease symptoms caused by RGSV,such as dwarfing and excess tillering,in transgenic rice plants.We found that both transgenic expression of P3 and RGSV infection induce ubiquitination and UPS-dependent degradation of rice NUCLEAR RNA POLYMERASE D1a(OsNRPD1a),one of two orthologs of the largest subunit of plant-specific RNA polymerase IV(Pol IV),which is required for RNA-directed DNA methylation(RdDM).Furthermore,we identified a P3-inducible U-box type E3 ubiquitin ligase,designated as P3-inducible protein 1(P3IP1),which interacts with OsNRPD1a and mediates its ubiquitination and UPS-dependent degradation in vitro and in vivo.Notably,both knockdown of OsNRPD1 and overexpression of P3IP1 in rice plants induced developmental phenotypes similar to RGSV disease symptomss.Taken together,our findings reveal a novel virulence mechanism whereby plant pathogens target host RNA Pol IV for UPS-dependent degradation to induce disease symptoms.Our study also identified an E3 ubiquitin ligase,which targets the RdDM compotent NRPD1 for UPS-mediated degradation in rice.展开更多
Introduction:Forests form a major component of the carbon(C)reserves in the world’s ecosystems.However,little is known on how management influences C stocks of woody vegetation,particularly in dry areas.We developed ...Introduction:Forests form a major component of the carbon(C)reserves in the world’s ecosystems.However,little is known on how management influences C stocks of woody vegetation,particularly in dry areas.We developed regression models for two dominant tree species to predict C stocks and quantified the potential of community managed forests as C sinks.Methods:Plots were randomly selected from community-managed natural forest,herbivore exclosures,and from communal grazing land.Tree and shrub biomass were estimated using a regression model on the most dominant woody species while herbaceous biomass was determined using destructive sampling.Results:The simplest model,based on only one single predictor variable,showed a good fit to the data for both species(Juniperus procera and Acacia abyssinica).Diameter at breast height(r2>0.95)was a more reliable predictor than height(r2>0.54),crown diameter(r2>0.68)(p<0.001).The C content of the total biomass for the managed natural forest and the exclosure were estimated as,58.11 and 22.29 Mg ha−1,respectively,while that for the grazing land was 7.76 Mg ha−1,and the mean carbon content between the three land uses were significantly different(p<0.05).Conclusions:We conclude that forests managed by the community have a high potential for C sequestration and storage and their conservation should be promoted.展开更多
Aims to determine the detectability of a global weedy perennial weed Hypochaeris radicata and its relationship with five common observer,species and environmental variables.Methods trained independent observers conduc...Aims to determine the detectability of a global weedy perennial weed Hypochaeris radicata and its relationship with five common observer,species and environmental variables.Methods trained independent observers conducted time-limited repeat sur-veys of H.radicata during autumn in an endangered grassy box-gum woodland ecosystem in south-east australia.single-species single-season site-occupancy modelling was used to determine if detectability of H.radicata was altered by five covariates,observer,litter height,grazing,maximum plant height and flowering state.Important Findings Detectability for H.radicata varied significantly with observer,litter height,plant maximum height and flowering state,but not with graz-ing.Despite significant observer-specific variation,there was a con-sistent increase in detectability with plant height and when plants are in flower for all observers.Detectability generally decreased as litter height increases.Perfect or constant detection rates cannot be assumed in plant surveys,even for easily recognizable plants in simple survey conditions.understanding how detectability is influ-enced by common survey variables can help improve the efficacy of plant monitoring programs by quantifying the extent of uncertainty in inferences made from survey data,or by determining optimal sur-vey conditions to increase the reliability of collected data.For plants with traits similar to H.radicata,surveying when most plants are at maximum height or in flower,increasing search intensity when litter levels are high and minimizing observer-related heterogeneity are potentially simple and effective ways to reduce detection errors.We speculate that detection rates may be lower,more variable and involve additional covariates when surveying during the peak flow-ering spring season with the presence of more warm season and taller annual species.展开更多
文摘The following investigations were conducted to evaluate grassy strips of different age for organic arable fields. From September 2009 to October 2010, adult ground beetles were sampled by pitfall traps in three grassy strips (2, 4, and 9 years old), their adjacent cropping areas, their field edges, and a control field (age 0) in Schleswig-Holstein, northern Germany. Carabid assemblages were similar among the fields, strips and edges. Grassy strips and edges had higher species richness and lower activity density than the control field. Activity density increased with increasing distance from the field edge in grassy strips and in the adjacent fields. In cropping areas, species richness andShannon’s H increased with increasing age of strips, whereas evenness and activity density decreased with increasing distance from the field edges. Compared to carnivorous and phytophagous carbides, omnivorous species were affected less by age of strips and distance from field margins. In the strips, species richness of the dominant species increased with age and decreased with distance, but the effect of strip age on species richness was still found in more than150 mfrom the margin. A positive effect of the age of grassy strips on species richness was found for cropping fields, grassy strips and field edges. Old grassy strips also exerted greater influence on the species richness and biodiversity of the adjacent arable fields than the younger strips.
基金supported by the National Magnetic Confinement Fusion Energy R&D Program of China(No.2017YFE0301300)National Natural Science Foundation of China(Nos.12005257 and 11905143)+1 种基金the Key Research Program of Frontier Sciences,the CASHIPS Director’s Fund(No.YZJJ2020QN13)Special Research Assistant Funding of CAS and China Postdoctoral Science Foundation(No.2020M671913)。
文摘The properties of grassy edge-localized modes(ELMs)in EAST in the favorable and unfavorable Btare statistically studied.Statistical analysis indicates that there is no systematical difference in the frequencies of grassy ELMs under the two different magnetic configurations in the similar parameter spaces.The high-frequency grassy ELM(fELM>1 k Hz)in unfavorable Bt is dependent on the high poloidal betaβpand high triangularityδu,while the high-frequency grassy ELM(fELM>1k Hz)in favorable Btappears to rely on the high plasma density.A frequently occurring phenomenon in favorable Btdefined as‘clustered ELM’seems to be the most evident difference in ELM behavior between favorable and unfavorable Bt.Statistical analysis shows that larger plasma-wall outer gap,longer plasma elongation,lower low-hybrid wave heating power and electron cyclotron resonance heating power favor the occurrence of clustered grassy ELMs.Further studies indicate that the generation of clustered grassy ELMs could be correlated with the lower electron temperature in the bulk plasma.
文摘The aim of this study was to analyze the effects of mechanical perforation of a golf course grassy sward, subject to maintenance machinery traffic and golf players trampling on its compaction and density. The evolution of soil compaction state after aeration was also conducted in four stages of measurement. This operation aims to improve the structure and soil texture, which is also called ＂perforation＂ or ＂coring＂. The taken cores leaving on the soil holes of adjustable depth and density （350 holes/mE） are made with an aerator machine called Vertidrain. Soil resistance to penetration and density were determined at the initial state before aeration as well as 10, 20, and 30 days after aeration. Compared to the initial state, the results show that mechanical aeration greatly affects the grassy sward ground by reducing its resistance to penetration as 35% and 43% decrease in penetration resistance were noticed at 5 cm depth l0 and 20 days after aeration, respectively. Also, resistance to penetration decreased by 41% and 48% at 15 cm depth during the same two periods of time with a relatively constant moisture content. However, soil resistance to penetration at 5 and 15 cm depths only decreased by 21% and 26%, respectively. Regarding the soil density measured after aeration, a significant improvement at the 1% level with the method of variance analysis was observed compared to that at the initial state （e.g. 1.33 g·cm^-3） Indeed, the density was 1.29, 1.26 and 1.30 gcm^-3 10, 20 and 30 days after aeration, respectively.
文摘In a golf course located at El Kantaoui, Sousse, Tunisia, this study was carried out over a sandy soil grassy sward to investigate the effects of mechanical aeration （perforation of the sward with an aerators machine called ＂Vertidrain＂） on its compaction and hydraulic conductivity. For this purpose, many soil cores were extracted using a 1.6 e.g. m effective width Verti-Drain aerator equipped with hollow spades spaced 65 e.g. mm apart. Aeration was performed at a rate of 350 holes/m2. Soil resistance to penetration and permeability were determined at the initial state before aeration as well as 10, 20, and 30 days after aeration. Compared to the initial state, the results showed that mechanical aeration greatly affects the grassy sward ground by reducing its resistance to penetration as 35% and 43% decrease in penetration resistance were noticed at 5 e.g. cm depth 10 and 20 days after aeration, respectively. Also, resistance to penetration decreased by 41% and 48% at 15 e.g. cm depth during the same two periods of time with a relatively constant moisture content. However, soil resistance to penetration at 5 and 15 e.g. cm depths only decreased by 21% and 26%, respectively. Regarding the soil hydraulic conductivity measured after aeration, a significant improvement at the 1% level with the method of variance analysis, was observed compared to that at the initial state （4.9 e.g. cm hl）. Indeed, the hydraulic conductivity was 12.5, 13, and 14.1 e.g. cm h-1 10, 20, and 30 days after aeration, respectively.
文摘Change silt charge of water in the rivers can negatively be reflected in throughput the rivers beds,stability of coast,change of river structures,disappearance of boggy places,etc.In work questions of variability silt charge waters in the river Sluch in time and on length of the river are considered.It is revealed that in time average and maximal silt charge waters decrease.While on length of the river change silt charge waters is shown not precisely,similar on some increase silt charge waters to a mouth of the river.The researches led by the factorial analysis and graphic-analytical method on the basis of long-term materials of measurement of charges of water have shown that,on a part of posts average depth of water in the river grows,and on others-cyclically changes with the general tendency to reduction.Average speed in them,accordingly,falls and grows.Stratification of interrelations of a silt charge with other factors on years is observed.The reasons of reduction of a silt charge are:1)agrarian and forest meliorative actions on a catchments of the river,hydraulic engineering construction;2)grassy bed of the river;3)change of a climate that promotes growth of temperature of a surface of soils and grassy bed of the river.In developed natural-climatic conditions expediently application on reservoirs of the antierosion organization of territory of the land tenure including agrarian-forests-meliorative actions that will allow to adjust outflow of a moisture from reservoirs to lower warming up of a surface of the soils,to provide against a high water protection and it will favorably be reflected in manufacture of agricultural production.
文摘Chromium hexacyanoferrate (CrHCF) modified grassy carbon electrode (GC) in different electrolytes was studied by cyclic voltammetry and in situ FTIR spectroelectrochemistry. The results indicate that the behavior of CrHCF firm can be understood in term of two structures: Cr1/3Cr(III)Fe(II)(CN), and MCr(III)Fe(II)(CN)(6). Besides,the film exists in amorphous state: the outer layer is porous film, while the inner layer is relatively compact. According to the electrochemical reaction of CrHCF, the lattice can contract and expand with the cations' diffusion.
基金This work was supported by the National Natural Science Foundation of China(no.31772128,31722045,U1905203,and 31701757)the Fok Ying Tung Education Foundation(161024).
文摘The ubiquitin-proteasome system(UPS)is an important post-translational regulatory mechanism that controls many cellular functions in eukaryotes.Here,we show that stable expression of P3 protein encoded by Rice grassy stunt virus(RGSV),a negative-strand RNA virus in the Bunyavirales,causes developmental abnormities similar to the disease symptoms caused by RGSV,such as dwarfing and excess tillering,in transgenic rice plants.We found that both transgenic expression of P3 and RGSV infection induce ubiquitination and UPS-dependent degradation of rice NUCLEAR RNA POLYMERASE D1a(OsNRPD1a),one of two orthologs of the largest subunit of plant-specific RNA polymerase IV(Pol IV),which is required for RNA-directed DNA methylation(RdDM).Furthermore,we identified a P3-inducible U-box type E3 ubiquitin ligase,designated as P3-inducible protein 1(P3IP1),which interacts with OsNRPD1a and mediates its ubiquitination and UPS-dependent degradation in vitro and in vivo.Notably,both knockdown of OsNRPD1 and overexpression of P3IP1 in rice plants induced developmental phenotypes similar to RGSV disease symptomss.Taken together,our findings reveal a novel virulence mechanism whereby plant pathogens target host RNA Pol IV for UPS-dependent degradation to induce disease symptoms.Our study also identified an E3 ubiquitin ligase,which targets the RdDM compotent NRPD1 for UPS-mediated degradation in rice.
文摘Introduction:Forests form a major component of the carbon(C)reserves in the world’s ecosystems.However,little is known on how management influences C stocks of woody vegetation,particularly in dry areas.We developed regression models for two dominant tree species to predict C stocks and quantified the potential of community managed forests as C sinks.Methods:Plots were randomly selected from community-managed natural forest,herbivore exclosures,and from communal grazing land.Tree and shrub biomass were estimated using a regression model on the most dominant woody species while herbaceous biomass was determined using destructive sampling.Results:The simplest model,based on only one single predictor variable,showed a good fit to the data for both species(Juniperus procera and Acacia abyssinica).Diameter at breast height(r2>0.95)was a more reliable predictor than height(r2>0.54),crown diameter(r2>0.68)(p<0.001).The C content of the total biomass for the managed natural forest and the exclosure were estimated as,58.11 and 22.29 Mg ha−1,respectively,while that for the grazing land was 7.76 Mg ha−1,and the mean carbon content between the three land uses were significantly different(p<0.05).Conclusions:We conclude that forests managed by the community have a high potential for C sequestration and storage and their conservation should be promoted.
文摘Aims to determine the detectability of a global weedy perennial weed Hypochaeris radicata and its relationship with five common observer,species and environmental variables.Methods trained independent observers conducted time-limited repeat sur-veys of H.radicata during autumn in an endangered grassy box-gum woodland ecosystem in south-east australia.single-species single-season site-occupancy modelling was used to determine if detectability of H.radicata was altered by five covariates,observer,litter height,grazing,maximum plant height and flowering state.Important Findings Detectability for H.radicata varied significantly with observer,litter height,plant maximum height and flowering state,but not with graz-ing.Despite significant observer-specific variation,there was a con-sistent increase in detectability with plant height and when plants are in flower for all observers.Detectability generally decreased as litter height increases.Perfect or constant detection rates cannot be assumed in plant surveys,even for easily recognizable plants in simple survey conditions.understanding how detectability is influ-enced by common survey variables can help improve the efficacy of plant monitoring programs by quantifying the extent of uncertainty in inferences made from survey data,or by determining optimal sur-vey conditions to increase the reliability of collected data.For plants with traits similar to H.radicata,surveying when most plants are at maximum height or in flower,increasing search intensity when litter levels are high and minimizing observer-related heterogeneity are potentially simple and effective ways to reduce detection errors.We speculate that detection rates may be lower,more variable and involve additional covariates when surveying during the peak flow-ering spring season with the presence of more warm season and taller annual species.
