The importance of enhancing sludge dewaterability is increasing due to the considerable impact of excess sludge volume on disposal costs and on overall sludge management. This study presents an innovative approach to ...The importance of enhancing sludge dewaterability is increasing due to the considerable impact of excess sludge volume on disposal costs and on overall sludge management. This study presents an innovative approach to enhance dewaterability of anaerobic digestate（AD） harvested from a wastewater treatment plant. The combination of zero valent iron（ZVI, 0–4.0 g/g total solids（TS）） and hydrogen peroxide（HP, 0–90 mg/g TS） under pH 3.0 significantly enhanced the AD dewaterability. The largest enhancement of AD dewaterability was achieved at 18 mg HP/g TS and 2.0 g ZVI/g TS, with the capillary suction time reduced by up to 90%. Economic analysis suggested that the proposed HP and ZVI treatment has more economic benefits in comparison with the classical Fenton reaction process. The destruction of extracellular polymeric substances and cells as well as the decrease of particle size were supposed to contribute to the enhanced AD dewaterability by HP ＋ ZVI conditioning.展开更多
[Objective]The objective of the study was to elucidate the duplicate collinearity diagnosis method for soil nutrient and provide basis for establishment of multiple regression model of relationship between independent...[Objective]The objective of the study was to elucidate the duplicate collinearity diagnosis method for soil nutrient and provide basis for establishment of multiple regression model of relationship between independent variable and depen-dent variable in fruit trees.[Method]An investigation on soil nutrients and'Fuji'fruit quality was conducted at 153 commercial apple orchards in the production re-gions of 51 counties in China from 2011 to 2012.At first,the regression equation was used to do the duplicate collinearity diagnosis,and then the partial least squares regression was used to analyze the weights of different soil nutrients that affected the fruit quality and screen out main soil nutrients.[Result]The results showed the conditional number between soil nutrients was 61.31,and the correlation coefficient of soil pH and available calcium,iron was 0.82 and-0.824 respectively,which demonstrated that there was multicollinearity between various soil nutrient contents.The soil organic matter,total nitrogen,available potassium,available nitro-gen,available phosphorus,available zinc,available iron and available boron showed positive effect Ioadings on fruit quality,while the}oadings and weights of the effects of available calcium and pH on fruit quality were negative.The variable importance for projection method was adopted to get the orders of the effects of major soil nu-trients on fruit quality,which was in the order of soil available calcium,nitrogen,available iron,available phosphorous,organic matter and available boron.The solu-ble solid content of the fruit was affected by soil organic matter,available phospho-rus,available iron,available boron and soil pH.[Conclusion]This study provided an analysis method and theoretical basis for the study and analysis on the relationships between dependent variables and multi-objective optimization,as well as the effects of soil nutrients on fruit quality in fruit tree.展开更多
To address the difficulty of detecting low embedding rate and high-concealment CNV-QIM(complementary neighbor vertices-quantization index modulation)steganography in low bit-rate speech codec,the code-word correlation...To address the difficulty of detecting low embedding rate and high-concealment CNV-QIM(complementary neighbor vertices-quantization index modulation)steganography in low bit-rate speech codec,the code-word correlation model based on a BiLSTM(bi-directional long short-term memory)neural network is built to obtain the correlation features of the LPC codewords in speech codec in this paper.Then,softmax is used to classify and effectively detect low embedding rate CNV-QIM steganography in VoIP streams.The experimental results show that for speech steganography of short samples with low embedding rate,the BiLSTM method in this paper has a superior detection accuracy than state-of-the-art methods of the RNN-SM(recurrent neural network-steganalysis model)and SS-QCCN(simplest strong quantization codeword correlation network).At an embedding rate of 20%and a duration of 3 s,the detection accuracy of BiLSTM method reaches 75.7%,which is higher than that of RNNSM by 11.7%.Furthermore,the average testing time of samples(100%embedding)is 0.3 s,which shows that the method can realize real-time steganography detection of VoIP streams.展开更多
In arid and semi-arid irrigated croplands,the excessive accumulation of soluble salts in the root zone is an extensive problem that seriously limits crop yield and water productivity(WP).To avoid affects the yield pot...In arid and semi-arid irrigated croplands,the excessive accumulation of soluble salts in the root zone is an extensive problem that seriously limits crop yield and water productivity(WP).To avoid affects the yield potential of crops,the application of extra irrigation for leaching of excessive salts from the root zone was required.Quantitative knowledge of effects of the irrigation water salinity and leaching fraction(LF)on the relative yield(RY)and the unit water productivity of crop evapotranspiration(UWPET)and the unit water productivity of irrigation water(UWPI)were becoming gradually important.This article provided theoretical models for estimating the UWPs(UWPET and UWPI)and optimizing leaching fraction according to irrigation water salinity.In the present study,eight levels of irrigation water salinity(ECw=0.25,0.50,0.75,1,2,3,4,and 5 dS/m)and 39 levels of LF values ranging from 0.04 to 0.80 were set and tested to assessing their effects on the RY and UWPs for four typical crops(barley,bean,wheat,and maize)with different salt tolerance levels.Almost every curve determined between the UWPs and LFs for the four crops had an inflection point.It was indicated that the UWPET and UWPI could be maximized by optimizing the LF under different irrigation water salinities.Furthermore,the linear regression relationships were established to estimate the maximum values of UWPs and their corresponding optimal LFs for four crops by using the irrigation water salinity.Moreover,the theoretical models for estimating the UWPs were validated by data of wheat from previous literature,and the models could be suitable with acceptable relative errors when LFs ranging from 0.07 to 0.17.展开更多
In previous study, we found that the chemokine receptor 9 （CCR9） was highly expressed on CD4^＋T cells from patients with T-cell lineage acute lymphocytic leukemia （T-ALL） and mediated leukemia cell infiltration a...In previous study, we found that the chemokine receptor 9 （CCR9） was highly expressed on CD4^＋T cells from patients with T-cell lineage acute lymphocytic leukemia （T-ALL） and mediated leukemia cell infiltration and metastasis. Combined use of interleukin 2 （IL-2） and IL-4 promoted the internalization of CCR9 and therefore attenuated leukemia cell infiltration and metastasis. In this study, we preliminarily investigated the mechanism of internalization of CCR9 on MOLT4 cell model （a human leukemia T-cell line, naturally expresses CCR9） and found that IL-2 upregulated the cell surface expression of IL-4Rα （CD124） greatly, whereas IL-4 had no significant influence on α （CD25） and β subunits （CD122） of IL-2R. Moreover, specific inhibitors, such as staurosporine, H89 and heparin, inhibited internalization of CCR9, which indicated a role of protein kinase C （PKC） and G protein-coupled kinase 2 （GRK2）, respectively. Furthermore, GRK2 was upregulated and translocated to cell membrane in IL-2 and IL-4 treated cells which indicated that PKC could be a prerequisite for GRK2 activity.展开更多
Since 2005,the application of nano carbon(NC)in agriculture and environmental remediation has received considerable attention with most of the research focusing on plant growth and heavy metal absorption.However,littl...Since 2005,the application of nano carbon(NC)in agriculture and environmental remediation has received considerable attention with most of the research focusing on plant growth and heavy metal absorption.However,little is known about the potential effects of NC on soil erosion and nutrient loss.In this study,rainfall simulation tests were conducted on a soil plot(1 m×1 m,located in a semi-arid loess region of northwestern China),in which a mixture(5-cm below the soil surface)of NC(0,0.1%,0.5%,0.7% and 1.0% on a mass base)and sandy soil(same as the one in the plot)was embedded as three bands(5 cm wide,1 m long and 5 cm thick)at the three positions(top,middle and bottom of the plot),respectively.Before the rainfall simulation test,a mixed solution of potassium bromide(1.0 mol/L KBr),potassium nitrate(1.0 mol/L KNO_(3)),monopotassium phosphate(1.0 mol/L KH_(2)PQ_(4))was sprayed on the soil surface.Results showed that the sandy soil on the Loess Plateau with 0.7%NC addition(36.47 kg/hm^(2) on a mass basis)could improve soil water runoff,sediment yield,and nutrient loss in the semi-arid loess region of northwestern China,in addition to preventing soil water from deep percolation.Therefore,NC may have a great potential in soil erosion control on the Loess Plateau of China.展开更多
Soil amendment is one of the most effective methods to improve saline-alkali soil.In this study,laboratory experiments were conducted to verify the effect of 13 kinds of amendments and their combinations(Citric acid(N...Soil amendment is one of the most effective methods to improve saline-alkali soil.In this study,laboratory experiments were conducted to verify the effect of 13 kinds of amendments and their combinations(Citric acid(NM),Phosphogypsum(LS),Aluminum sulfate+citric acid(AL+NM),Aluminum sulfate+phosphogypsum(AL+LS),Aluminum sulfate+citric acid+phosphogypsum(HH),Zeolite(Z),Acidified zeolite(ZH),Aluminum sulfate(AL),Aluminum sulfate+zeolite(AL+Z),Aluminum sulfate+acidified zeolite(AL+ZH),Poly Aluminum chloride(ALCL),Polyaluminium chloride+zeolite(ALCL+Z),Polyaluminium chloride+acidified zeolite(ALCL+ZH))on soil pH,metal cations content,exchangeable Na+,exchangeable sodium percentage(ESP)in the lab.And then the five most effective amendments(Z,ZH,AL,AL+Z,and AL+ZH)were chosen applying both in dry field(maize field)and paddy field to evaluate their improvement on soda saline-alkali soil and crop yield in the northeast Songnen Plain,China.The lab results showed that AL,AL+Z and AL+ZH treatments could significantly reduce the pH in soil solution and increase the content of metal cations.Z and ZH treatments could adsorb metal cations in soil.Both in dry and paddy fields,all five treatments could increase the soil saturated hydraulic conductivity(Ks),increased from 9.63 to 60.02 mm/d and 0.18 to 33.25 mm/d,respectively,of which the AL treatment was the best;all five treatments could reduce the content of exchangeable Na+in soil,and decrease by 38.62%-61.33%and 25.24%-71.53%,respectively,of which the AL+ZH treatment was the best;all treatments could reduce soil exchangeable sodium percentage,and decrease by 0.14-0.22 and 0.14-0.41,respectively,of which the AL+ZH treatment was the best;AL,AL+Z and AL+ZH treatments could improve soil organic matter content;all treatments could effectively improve the yield of crops,and increase 23.98%-60.75%and 52.51%-260.21%,respectively,of which the AL treatment was the best in dry field and the AL+ZH treatment was the best in paddy field.The effect of AL treatment was the best in dry field and AL+ZH treatment was the best in paddy field of soda saline-alkali soil.This study could provide instructive information for the chemical improvement and agricultural utilization of soda saline-alkali soils in the world.展开更多
Salt stress is considered one of the primary threats to cotton production.Although cotton is found to have reasonable salt tolerance,it is sensitive to salt stress during the seedling stage.This research aimed to prop...Salt stress is considered one of the primary threats to cotton production.Although cotton is found to have reasonable salt tolerance,it is sensitive to salt stress during the seedling stage.This research aimed to propose an effective method for rapidly detecting salt stress of cotton seedlings using multicolor fluorescence-multispectral reflectance imaging coupled with deep learning.A prototyping platform that can obtain multicolor fluorescence and multispectral reflectance images synchronously was developed to get different characteristics of each cotton seedling.The experiments revealed that salt stress harmed cotton seedlings with an increase in malondialdehyde and a decrease in chlorophyll content,superoxide dismutase,and catalase after 17 days of salt stress.The Relief algorithm and principal component analysis were introduced to reduce data dimension with the first 9 principal component images(PC1 to PC9)accounting for 95.2%of the original variations.An optimized EfficientNet-B2(EfficientNet-OB2),purposely used for a fixed resource budget,was established to detect salt stress by optimizing a proportional number of convolution kernels assigned to the first convolution according to the corresponding contributions of PC1 to PC9 images.EfficientNet-OB2 achieved an accuracy of 84.80%,91.18%,and 95.10%for 5,10,and 17 days of salt stress,respectively,which outperformed EfficientNet-B2 and EfficientNet-OB4 with higher training speed and fewer parameters.The results demonstrate the potential of combining multicolor fluorescence-multispectral reflectance imaging with the deep learning model EfficientNet-OB2 for salt stress detection of cotton at the seedling stage,which can be further deployed in mobile platforms for high-throughput screening in the field.展开更多
基金the Australian Research Council Discovery Early Career Researcher Award(No.DE160100667)the Australian Research Council Discovery Project(No.DP170102812)+1 种基金the Philanthropic Grant for Early Career Engineering Researcher(No.GE12015)the postdoctoral fellowship support from the Japan Society for the Promotion of Science(JSPS)(No.268245)
文摘The importance of enhancing sludge dewaterability is increasing due to the considerable impact of excess sludge volume on disposal costs and on overall sludge management. This study presents an innovative approach to enhance dewaterability of anaerobic digestate（AD） harvested from a wastewater treatment plant. The combination of zero valent iron（ZVI, 0–4.0 g/g total solids（TS）） and hydrogen peroxide（HP, 0–90 mg/g TS） under pH 3.0 significantly enhanced the AD dewaterability. The largest enhancement of AD dewaterability was achieved at 18 mg HP/g TS and 2.0 g ZVI/g TS, with the capillary suction time reduced by up to 90%. Economic analysis suggested that the proposed HP and ZVI treatment has more economic benefits in comparison with the classical Fenton reaction process. The destruction of extracellular polymeric substances and cells as well as the decrease of particle size were supposed to contribute to the enhanced AD dewaterability by HP ＋ ZVI conditioning.
文摘[Objective]The objective of the study was to elucidate the duplicate collinearity diagnosis method for soil nutrient and provide basis for establishment of multiple regression model of relationship between independent variable and depen-dent variable in fruit trees.[Method]An investigation on soil nutrients and'Fuji'fruit quality was conducted at 153 commercial apple orchards in the production re-gions of 51 counties in China from 2011 to 2012.At first,the regression equation was used to do the duplicate collinearity diagnosis,and then the partial least squares regression was used to analyze the weights of different soil nutrients that affected the fruit quality and screen out main soil nutrients.[Result]The results showed the conditional number between soil nutrients was 61.31,and the correlation coefficient of soil pH and available calcium,iron was 0.82 and-0.824 respectively,which demonstrated that there was multicollinearity between various soil nutrient contents.The soil organic matter,total nitrogen,available potassium,available nitro-gen,available phosphorus,available zinc,available iron and available boron showed positive effect Ioadings on fruit quality,while the}oadings and weights of the effects of available calcium and pH on fruit quality were negative.The variable importance for projection method was adopted to get the orders of the effects of major soil nu-trients on fruit quality,which was in the order of soil available calcium,nitrogen,available iron,available phosphorous,organic matter and available boron.The solu-ble solid content of the fruit was affected by soil organic matter,available phospho-rus,available iron,available boron and soil pH.[Conclusion]This study provided an analysis method and theoretical basis for the study and analysis on the relationships between dependent variables and multi-objective optimization,as well as the effects of soil nutrients on fruit quality in fruit tree.
基金This research was supported by the National Natural Science Foundation of China(No.61862002).
文摘To address the difficulty of detecting low embedding rate and high-concealment CNV-QIM(complementary neighbor vertices-quantization index modulation)steganography in low bit-rate speech codec,the code-word correlation model based on a BiLSTM(bi-directional long short-term memory)neural network is built to obtain the correlation features of the LPC codewords in speech codec in this paper.Then,softmax is used to classify and effectively detect low embedding rate CNV-QIM steganography in VoIP streams.The experimental results show that for speech steganography of short samples with low embedding rate,the BiLSTM method in this paper has a superior detection accuracy than state-of-the-art methods of the RNN-SM(recurrent neural network-steganalysis model)and SS-QCCN(simplest strong quantization codeword correlation network).At an embedding rate of 20%and a duration of 3 s,the detection accuracy of BiLSTM method reaches 75.7%,which is higher than that of RNNSM by 11.7%.Furthermore,the average testing time of samples(100%embedding)is 0.3 s,which shows that the method can realize real-time steganography detection of VoIP streams.
基金This research was financially supported by the National Natural Science Foundation of China(Grant Nos.41830754,U1706211,41977007,51679190,51979220)and National Key R&D Program of China(Grant Nos.2016YFC0501401)and Natural Science Foundation of Shaanxi Province(2018JQ5094).
文摘In arid and semi-arid irrigated croplands,the excessive accumulation of soluble salts in the root zone is an extensive problem that seriously limits crop yield and water productivity(WP).To avoid affects the yield potential of crops,the application of extra irrigation for leaching of excessive salts from the root zone was required.Quantitative knowledge of effects of the irrigation water salinity and leaching fraction(LF)on the relative yield(RY)and the unit water productivity of crop evapotranspiration(UWPET)and the unit water productivity of irrigation water(UWPI)were becoming gradually important.This article provided theoretical models for estimating the UWPs(UWPET and UWPI)and optimizing leaching fraction according to irrigation water salinity.In the present study,eight levels of irrigation water salinity(ECw=0.25,0.50,0.75,1,2,3,4,and 5 dS/m)and 39 levels of LF values ranging from 0.04 to 0.80 were set and tested to assessing their effects on the RY and UWPs for four typical crops(barley,bean,wheat,and maize)with different salt tolerance levels.Almost every curve determined between the UWPs and LFs for the four crops had an inflection point.It was indicated that the UWPET and UWPI could be maximized by optimizing the LF under different irrigation water salinities.Furthermore,the linear regression relationships were established to estimate the maximum values of UWPs and their corresponding optimal LFs for four crops by using the irrigation water salinity.Moreover,the theoretical models for estimating the UWPs were validated by data of wheat from previous literature,and the models could be suitable with acceptable relative errors when LFs ranging from 0.07 to 0.17.
基金This study was supported by the National Natural Science Foundation of China （No. 30570780）, National Ministry of Education Doctoral Fund （No. 200804860039） and Department of Science and Technology of Hubei Province, China （No. 2006AA301B64）.
文摘In previous study, we found that the chemokine receptor 9 （CCR9） was highly expressed on CD4^＋T cells from patients with T-cell lineage acute lymphocytic leukemia （T-ALL） and mediated leukemia cell infiltration and metastasis. Combined use of interleukin 2 （IL-2） and IL-4 promoted the internalization of CCR9 and therefore attenuated leukemia cell infiltration and metastasis. In this study, we preliminarily investigated the mechanism of internalization of CCR9 on MOLT4 cell model （a human leukemia T-cell line, naturally expresses CCR9） and found that IL-2 upregulated the cell surface expression of IL-4Rα （CD124） greatly, whereas IL-4 had no significant influence on α （CD25） and β subunits （CD122） of IL-2R. Moreover, specific inhibitors, such as staurosporine, H89 and heparin, inhibited internalization of CCR9, which indicated a role of protein kinase C （PKC） and G protein-coupled kinase 2 （GRK2）, respectively. Furthermore, GRK2 was upregulated and translocated to cell membrane in IL-2 and IL-4 treated cells which indicated that PKC could be a prerequisite for GRK2 activity.
基金The authors sincerely acknowledge that this work was financially supported jointly by National Natural Science Foundation of China(41371239,51239009)Science and Technology Planning Project of Shaanxi Province(2013kjxx-38).
文摘Since 2005,the application of nano carbon(NC)in agriculture and environmental remediation has received considerable attention with most of the research focusing on plant growth and heavy metal absorption.However,little is known about the potential effects of NC on soil erosion and nutrient loss.In this study,rainfall simulation tests were conducted on a soil plot(1 m×1 m,located in a semi-arid loess region of northwestern China),in which a mixture(5-cm below the soil surface)of NC(0,0.1%,0.5%,0.7% and 1.0% on a mass base)and sandy soil(same as the one in the plot)was embedded as three bands(5 cm wide,1 m long and 5 cm thick)at the three positions(top,middle and bottom of the plot),respectively.Before the rainfall simulation test,a mixed solution of potassium bromide(1.0 mol/L KBr),potassium nitrate(1.0 mol/L KNO_(3)),monopotassium phosphate(1.0 mol/L KH_(2)PQ_(4))was sprayed on the soil surface.Results showed that the sandy soil on the Loess Plateau with 0.7%NC addition(36.47 kg/hm^(2) on a mass basis)could improve soil water runoff,sediment yield,and nutrient loss in the semi-arid loess region of northwestern China,in addition to preventing soil water from deep percolation.Therefore,NC may have a great potential in soil erosion control on the Loess Plateau of China.
基金the National Natural Science Foundation of China(Grant No.41977007,No.41807131,No.41830754)China Postdoctoral Science Foundation(Grant No.2019M653707)+1 种基金Research project of State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China(Grant No.2019KJCXTD-4,QJNY-2019-01)this study was supported by:China Three Gorges Corporation and it contributes to the following projects:BHT/0869.
文摘Soil amendment is one of the most effective methods to improve saline-alkali soil.In this study,laboratory experiments were conducted to verify the effect of 13 kinds of amendments and their combinations(Citric acid(NM),Phosphogypsum(LS),Aluminum sulfate+citric acid(AL+NM),Aluminum sulfate+phosphogypsum(AL+LS),Aluminum sulfate+citric acid+phosphogypsum(HH),Zeolite(Z),Acidified zeolite(ZH),Aluminum sulfate(AL),Aluminum sulfate+zeolite(AL+Z),Aluminum sulfate+acidified zeolite(AL+ZH),Poly Aluminum chloride(ALCL),Polyaluminium chloride+zeolite(ALCL+Z),Polyaluminium chloride+acidified zeolite(ALCL+ZH))on soil pH,metal cations content,exchangeable Na+,exchangeable sodium percentage(ESP)in the lab.And then the five most effective amendments(Z,ZH,AL,AL+Z,and AL+ZH)were chosen applying both in dry field(maize field)and paddy field to evaluate their improvement on soda saline-alkali soil and crop yield in the northeast Songnen Plain,China.The lab results showed that AL,AL+Z and AL+ZH treatments could significantly reduce the pH in soil solution and increase the content of metal cations.Z and ZH treatments could adsorb metal cations in soil.Both in dry and paddy fields,all five treatments could increase the soil saturated hydraulic conductivity(Ks),increased from 9.63 to 60.02 mm/d and 0.18 to 33.25 mm/d,respectively,of which the AL treatment was the best;all five treatments could reduce the content of exchangeable Na+in soil,and decrease by 38.62%-61.33%and 25.24%-71.53%,respectively,of which the AL+ZH treatment was the best;all treatments could reduce soil exchangeable sodium percentage,and decrease by 0.14-0.22 and 0.14-0.41,respectively,of which the AL+ZH treatment was the best;AL,AL+Z and AL+ZH treatments could improve soil organic matter content;all treatments could effectively improve the yield of crops,and increase 23.98%-60.75%and 52.51%-260.21%,respectively,of which the AL treatment was the best in dry field and the AL+ZH treatment was the best in paddy field.The effect of AL treatment was the best in dry field and AL+ZH treatment was the best in paddy field of soda saline-alkali soil.This study could provide instructive information for the chemical improvement and agricultural utilization of soda saline-alkali soils in the world.
基金supported by the National Natural Science Foundation of China(Grant Nos.41977007 and 41830754)the Outstanding Young Scientific Research Talents Program of Fujian Agriculture and Forestry University(Grant No.xjq202117)the Open Research Fund Program of State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xian University of Technology(Grant No.2021KFKT-6).
文摘Salt stress is considered one of the primary threats to cotton production.Although cotton is found to have reasonable salt tolerance,it is sensitive to salt stress during the seedling stage.This research aimed to propose an effective method for rapidly detecting salt stress of cotton seedlings using multicolor fluorescence-multispectral reflectance imaging coupled with deep learning.A prototyping platform that can obtain multicolor fluorescence and multispectral reflectance images synchronously was developed to get different characteristics of each cotton seedling.The experiments revealed that salt stress harmed cotton seedlings with an increase in malondialdehyde and a decrease in chlorophyll content,superoxide dismutase,and catalase after 17 days of salt stress.The Relief algorithm and principal component analysis were introduced to reduce data dimension with the first 9 principal component images(PC1 to PC9)accounting for 95.2%of the original variations.An optimized EfficientNet-B2(EfficientNet-OB2),purposely used for a fixed resource budget,was established to detect salt stress by optimizing a proportional number of convolution kernels assigned to the first convolution according to the corresponding contributions of PC1 to PC9 images.EfficientNet-OB2 achieved an accuracy of 84.80%,91.18%,and 95.10%for 5,10,and 17 days of salt stress,respectively,which outperformed EfficientNet-B2 and EfficientNet-OB4 with higher training speed and fewer parameters.The results demonstrate the potential of combining multicolor fluorescence-multispectral reflectance imaging with the deep learning model EfficientNet-OB2 for salt stress detection of cotton at the seedling stage,which can be further deployed in mobile platforms for high-throughput screening in the field.
