This paper studies how the price movements of pork,chicken and egg respond to those of related cost factors in short terms in Chinese market.We employ a linear quantile approach not only to explore potential data hete...This paper studies how the price movements of pork,chicken and egg respond to those of related cost factors in short terms in Chinese market.We employ a linear quantile approach not only to explore potential data heteroscedasticity but also to generate confidence bands for the purpose of price stability study.We then evaluate our models by comparing the prediction intervals generated from the quantile regression models with in-sample and out-of-sample forecasts.Using monthly data from January 2000 to October 2010,we observed these findings：（i） the price changes of cost factors asymmetrically and unequally influence those of the livestock across different quantiles;（ii） the performance of our models is robust and consistent for both in-sample and out-of-sample forecasts;（iii） the confidence intervals generated from 0.05th and 0.95th quantile regression models are good methods to forecast livestock price fluctuation.展开更多
Ensuring an acceptable level of edible agro-products quality and safety is necessary to provide adequate protection for con- sumers. It is the first time that we analyzed the edible agro-products quality and safety is...Ensuring an acceptable level of edible agro-products quality and safety is necessary to provide adequate protection for con- sumers. It is the first time that we analyzed the edible agro-products quality and safety issues in the supply chain, including production, processing, circulation, and consumption. The results indicate that the agro-products quality and safety levels improves steadily, and the supervision system and standardization system are both enhanced significantly, however, certain challenges still remain in each stage of the supply chain and the entire supervision process. Finally, five recommendations regarding four aspects （production, processing, circulation, and consumption） are concluded.展开更多
The paper studies the relationship, adjustment ability, path, efficiency and intensity of price transmission in the swine industry chain in China, which consists of the prices of corn, compound feed for fattening pig,...The paper studies the relationship, adjustment ability, path, efficiency and intensity of price transmission in the swine industry chain in China, which consists of the prices of corn, compound feed for fattening pig, piglet, pig and pork. Monthly prices covering a period of 18 yr （1994-2011） are analyzed using a Market-Chain Cooperated Model （MCM）. The empirical results show that there exists a stable long-term cointegration and short-term dynamic relationship in the price system. First, the adjustment speed of each price series is very slow and the transmission path is top-down and one-way significantly. Second, the price from upstream to downstream lags about 2 mort, while there is no lag in price transmission from midstream to downstream. Third, in terms of price transmission intensity, the price of pig impacted greatly on pork price, not only in the current period but also through the whole period. Besides, the price of corn has the largest lagged effects on pork price. According to the above empirical results, we suggest that government should strengthen monitoring and early warning of the swine industry chain, especially the upstream and midstream, attach great importance to the timely adjustment of feed prices and perfect the measures of price subsidy.展开更多
This paper establishes a short-term prediction model of weekly retail prices for eggs based on chaotic neural network with the weekly retail prices of eggs from January 2008 to December 2012 in China.In the process of...This paper establishes a short-term prediction model of weekly retail prices for eggs based on chaotic neural network with the weekly retail prices of eggs from January 2008 to December 2012 in China.In the process of determining the structure of the chaotic neural network,the number of input layer nodes of the network is calculated by reconstructing phase space and computing its saturated embedding dimension,and then the number of hidden layer nodes is estimated by trial and error.Finally,this model is applied to predict the retail prices of eggs and compared with ARIMA.The result shows that the chaotic neural network has better nonlinear fitting ability and higher precision in the prediction of weekly retail price of eggs.The empirical result also shows that the chaotic neural network can be widely used in the field of short-term prediction of agricultural prices.展开更多
The study analyses the theoretical mechanism through which environmental regulation affects the dairy industry’s technological progress,with a particular focus on how the effect is conditional on farm size.Using the ...The study analyses the theoretical mechanism through which environmental regulation affects the dairy industry’s technological progress,with a particular focus on how the effect is conditional on farm size.Using the input–output data of dairy farms of different sizes from 2009 to 2019 in 10 Chinese provinces/autonomous regions in China and the quantitative measurement index of environmental regulation,the study estimates environmental regulation’s heterogeneous influences on the dairy industry’s technological progress by dynamic panel data models.The empirical results suggest that,first,environmental regulation has a U-type influence on the technological progress of dairy farming.The U-type influence means moving from pollution control’s high cost and low technology progress to the high profit and high innovation input generated by optimizing the breeding structure.Second,the promotion of dairy farming technology depends on farm size.The effect of environmental regulation on technological progress in moderately large-farms showed a U-type relationship.In contrast,the effect in free-range and large-size dairy farms showed a linear and positive relationship.The government should further strengthen environmental regulation based on advancing moderately large-farms in compliance with market mechanisms in the long run.Particular attention should be paid to the forms of environmental regulation so that dairy cattle breeding technology can break through the inflection point of the“U”curve as soon as possible and ensure the significance of the rising stage.Along the way,technical support should be provided for realizing environmental protection and economic growth.展开更多
OBJECTIVE The Ginkgo Leaf Extract and Armillariella Mellea Powders Oral(Yinxingmihuan Koufu Rongye,YXMH),a representative drug for"Treating both Brain and Heart",showed considerable clinical effects in isch⁃...OBJECTIVE The Ginkgo Leaf Extract and Armillariella Mellea Powders Oral(Yinxingmihuan Koufu Rongye,YXMH),a representative drug for"Treating both Brain and Heart",showed considerable clinical effects in isch⁃emic cardiovascular and cerebral vascular diseases.Recently,it is reported that YXMH has the potential for treating myocardial and cerebral ischemia related mental disorders,such as post stroke depression(PSD)and chronic heart disease(CHD)associated anxiety disorder.However,its mechanism has not been clearly elucidated.Meanwhile,increasing evidence revealed that there are close functional links between depression and habenular nucleus.The present study investigates the underlying mechanism of YXMH on attenuating the inflammation of microglia in habenular nucleus through CX3CL1-CX3CR1 axis in in a rat model of PSD.METHODS Rats were randomly devided into sham group,model group,Ginaton group(18 mg·kg^-1),Armillariella Mellea group(600 mg·kg-1),Fluoxetine group(10 mg·kg^-1),YXMH high-dose group(618 mg·kg^-1)and YXMH low-dose group(309 mg·kg^-1).The PSD model was induced by transarterial microembolization combined with sleep deprivation(2-Chloro-D-phenylalanine,PCPA,IH,200 mg·kg^-1,for 3 times,before the behavior test)in SD male rats.Then rats were treated with corresponding medicaments through gavage once a day until 3 weeks later,followed by body mass measurement,neurological deficit score evaluation,gripping strength and thermal withdrawl latency measurement,as well as depression related behavioral indicators,the open field test(OFT)and sucrose preference test.The pathological morphological changes of habenular nucleus was observed by HE staining,the expression of IBA-1 was measured and analyzed by immunohistochemistry staining,and alterations of proteins and genes related to the CX3CL1-CX3CR1 axis were analyzed using Western blotting(CX3CL1,CX3CR1)and real-time polymerase chain reaction(PCR)(CX3CL1,CX3CR1).RESULTS Compared with the sham group,rats in the model group manifested as decreased body mass,deficient neurological behavior and gripping strength,reduced loco⁃motor activity and sugar water consumption,as well as elevated thermal withdrawl latency(P<0.05,P<0.01).Mean⁃while,the pathological morphology of the habenular nucleus on the ischemic hemisphere showed significant neuronal degeneration,microglial proliferation,inflammatory cells and glia cells infiltration,together with up-regualted expression of IBA-1,CX3CL1,CX3CR1 protein and CX3CL1,CX3CR1 mRNA.YXMH attenuated inflammation of microglia in habenular nucleus through improving pathological morphology,inhibiting IBA-1 activation,down-regulating the expres⁃sion of CX3CL1 and CX3CR1 proteins and genes,and thus improved the behavior performance of ischemic injury and depression.CONCLUSION YXMH ameliorates neurological deficit and depressive behavior in rat model of PSD induced by transarterial microembolization combined with sleep deprivation,and the mechanism is probably related to attenu⁃ating inflammation of microglia in habenular nucleus through CX3CL1-CX3CR1 axis.展开更多
基金supported by the Key Project of National Key Technology R&D Program of China(2009BADA9B01)
文摘This paper studies how the price movements of pork,chicken and egg respond to those of related cost factors in short terms in Chinese market.We employ a linear quantile approach not only to explore potential data heteroscedasticity but also to generate confidence bands for the purpose of price stability study.We then evaluate our models by comparing the prediction intervals generated from the quantile regression models with in-sample and out-of-sample forecasts.Using monthly data from January 2000 to October 2010,we observed these findings：（i） the price changes of cost factors asymmetrically and unequally influence those of the livestock across different quantiles;（ii） the performance of our models is robust and consistent for both in-sample and out-of-sample forecasts;（iii） the confidence intervals generated from 0.05th and 0.95th quantile regression models are good methods to forecast livestock price fluctuation.
基金supported by the Special Program of Agricultural Information (Agricultural Information Monitoring and Early Warning)supported by the Ministry of Agriculture of Chinathe Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences, China (CAAS-ASTIP-2015-AII-02)
文摘Ensuring an acceptable level of edible agro-products quality and safety is necessary to provide adequate protection for con- sumers. It is the first time that we analyzed the edible agro-products quality and safety issues in the supply chain, including production, processing, circulation, and consumption. The results indicate that the agro-products quality and safety levels improves steadily, and the supervision system and standardization system are both enhanced significantly, however, certain challenges still remain in each stage of the supply chain and the entire supervision process. Finally, five recommendations regarding four aspects （production, processing, circulation, and consumption） are concluded.
基金supported by the Key Projects of National Key Technology R&D Program during the 12th Five-Year Plan period(2012BAH20B04)the 948 Program of MoA of China(2012-Z1)the Technology and Construction of Agricultural Information Monitoring and Early Warning System of China(2012-ZL017)
文摘The paper studies the relationship, adjustment ability, path, efficiency and intensity of price transmission in the swine industry chain in China, which consists of the prices of corn, compound feed for fattening pig, piglet, pig and pork. Monthly prices covering a period of 18 yr （1994-2011） are analyzed using a Market-Chain Cooperated Model （MCM）. The empirical results show that there exists a stable long-term cointegration and short-term dynamic relationship in the price system. First, the adjustment speed of each price series is very slow and the transmission path is top-down and one-way significantly. Second, the price from upstream to downstream lags about 2 mort, while there is no lag in price transmission from midstream to downstream. Third, in terms of price transmission intensity, the price of pig impacted greatly on pork price, not only in the current period but also through the whole period. Besides, the price of corn has the largest lagged effects on pork price. According to the above empirical results, we suggest that government should strengthen monitoring and early warning of the swine industry chain, especially the upstream and midstream, attach great importance to the timely adjustment of feed prices and perfect the measures of price subsidy.
基金financially supported by the National KeyTechnology R&D Program during the 12th Five-Year Plan period(2012BAH20B04)the 948 Program of Ministry of Agriculture,China(2013-Z1)
文摘This paper establishes a short-term prediction model of weekly retail prices for eggs based on chaotic neural network with the weekly retail prices of eggs from January 2008 to December 2012 in China.In the process of determining the structure of the chaotic neural network,the number of input layer nodes of the network is calculated by reconstructing phase space and computing its saturated embedding dimension,and then the number of hidden layer nodes is estimated by trial and error.Finally,this model is applied to predict the retail prices of eggs and compared with ARIMA.The result shows that the chaotic neural network has better nonlinear fitting ability and higher precision in the prediction of weekly retail price of eggs.The empirical result also shows that the chaotic neural network can be widely used in the field of short-term prediction of agricultural prices.
基金supported by the Ministry of Agriculture and Rural Affairs,China(125D0301)。
文摘The study analyses the theoretical mechanism through which environmental regulation affects the dairy industry’s technological progress,with a particular focus on how the effect is conditional on farm size.Using the input–output data of dairy farms of different sizes from 2009 to 2019 in 10 Chinese provinces/autonomous regions in China and the quantitative measurement index of environmental regulation,the study estimates environmental regulation’s heterogeneous influences on the dairy industry’s technological progress by dynamic panel data models.The empirical results suggest that,first,environmental regulation has a U-type influence on the technological progress of dairy farming.The U-type influence means moving from pollution control’s high cost and low technology progress to the high profit and high innovation input generated by optimizing the breeding structure.Second,the promotion of dairy farming technology depends on farm size.The effect of environmental regulation on technological progress in moderately large-farms showed a U-type relationship.In contrast,the effect in free-range and large-size dairy farms showed a linear and positive relationship.The government should further strengthen environmental regulation based on advancing moderately large-farms in compliance with market mechanisms in the long run.Particular attention should be paid to the forms of environmental regulation so that dairy cattle breeding technology can break through the inflection point of the“U”curve as soon as possible and ensure the significance of the rising stage.Along the way,technical support should be provided for realizing environmental protection and economic growth.
基金National Natural Science Foundation of China(8187304081403141)
文摘OBJECTIVE The Ginkgo Leaf Extract and Armillariella Mellea Powders Oral(Yinxingmihuan Koufu Rongye,YXMH),a representative drug for"Treating both Brain and Heart",showed considerable clinical effects in isch⁃emic cardiovascular and cerebral vascular diseases.Recently,it is reported that YXMH has the potential for treating myocardial and cerebral ischemia related mental disorders,such as post stroke depression(PSD)and chronic heart disease(CHD)associated anxiety disorder.However,its mechanism has not been clearly elucidated.Meanwhile,increasing evidence revealed that there are close functional links between depression and habenular nucleus.The present study investigates the underlying mechanism of YXMH on attenuating the inflammation of microglia in habenular nucleus through CX3CL1-CX3CR1 axis in in a rat model of PSD.METHODS Rats were randomly devided into sham group,model group,Ginaton group(18 mg·kg^-1),Armillariella Mellea group(600 mg·kg-1),Fluoxetine group(10 mg·kg^-1),YXMH high-dose group(618 mg·kg^-1)and YXMH low-dose group(309 mg·kg^-1).The PSD model was induced by transarterial microembolization combined with sleep deprivation(2-Chloro-D-phenylalanine,PCPA,IH,200 mg·kg^-1,for 3 times,before the behavior test)in SD male rats.Then rats were treated with corresponding medicaments through gavage once a day until 3 weeks later,followed by body mass measurement,neurological deficit score evaluation,gripping strength and thermal withdrawl latency measurement,as well as depression related behavioral indicators,the open field test(OFT)and sucrose preference test.The pathological morphological changes of habenular nucleus was observed by HE staining,the expression of IBA-1 was measured and analyzed by immunohistochemistry staining,and alterations of proteins and genes related to the CX3CL1-CX3CR1 axis were analyzed using Western blotting(CX3CL1,CX3CR1)and real-time polymerase chain reaction(PCR)(CX3CL1,CX3CR1).RESULTS Compared with the sham group,rats in the model group manifested as decreased body mass,deficient neurological behavior and gripping strength,reduced loco⁃motor activity and sugar water consumption,as well as elevated thermal withdrawl latency(P<0.05,P<0.01).Mean⁃while,the pathological morphology of the habenular nucleus on the ischemic hemisphere showed significant neuronal degeneration,microglial proliferation,inflammatory cells and glia cells infiltration,together with up-regualted expression of IBA-1,CX3CL1,CX3CR1 protein and CX3CL1,CX3CR1 mRNA.YXMH attenuated inflammation of microglia in habenular nucleus through improving pathological morphology,inhibiting IBA-1 activation,down-regulating the expres⁃sion of CX3CL1 and CX3CR1 proteins and genes,and thus improved the behavior performance of ischemic injury and depression.CONCLUSION YXMH ameliorates neurological deficit and depressive behavior in rat model of PSD induced by transarterial microembolization combined with sleep deprivation,and the mechanism is probably related to attenu⁃ating inflammation of microglia in habenular nucleus through CX3CL1-CX3CR1 axis.
