The use of improved high yielding crop varieties is an important avenue for reducing hunger and food insecurity in developing countries. Using cross-sectional data obtained from a survey conducted during 2013 crop sea...The use of improved high yielding crop varieties is an important avenue for reducing hunger and food insecurity in developing countries. Using cross-sectional data obtained from a survey conducted during 2013 crop season, we performed a probit model (plot-level analysis) to determine the probability of adopting new improved rice varieties (NIRVs) by smallholder farmers particularly from two main agro-ecological regions (hills and tropical plain terai regions) of Central Nepal. The results revealed that education, extension services and seed access play significant roles in adoption decisions. Additionally, farm and field characteristic variables such as farm size, endowment of favorable land type (e.g. lowlands), and animal power (e.g. oxen) are the key factors influencing the probability of adopting NIRVs. The results showed that technology specific variables (e.g. yield potential and acceptability) are significant for explaining adoption behavior, implying that it is important to take farmers' preferences to varietal characteristics into consideration in the design of a research and development program. Given the significant role played by extension and access related variables, increased emphasis on information dissemination, field demonstration, and farmers' participatory research and training programs to popularize new rice varieties and enhance their adoption rate are required. This also suggests that policy intervention should be made on improving the educational status of farming households, and developing programs on varietal package of rice seed which offer farmers a variety of choices among the appropriate pools of germplasm. Such programs ultimately help farmers develop more profit-oriented behavior which are necessary to enhance adoption rate, production and food security in the long run.展开更多
An improved biosorbent of thiourea modified chitosan microsphere(TMCM) with high specific surface,favorable mechanical strength and excellent adsorption performance had been synthesized via microfluidic technology. ...An improved biosorbent of thiourea modified chitosan microsphere(TMCM) with high specific surface,favorable mechanical strength and excellent adsorption performance had been synthesized via microfluidic technology. Polyethylene glycol was used as a significant component added in aqueous solution of chitosan to produce such microspheres through droplets forming, chemical crosslinking and pores creating. For the improvement of adsorption capacity, thiourea was considered as an excellent choice in increasing amino functional group by graft modification. The SEM, FTIR and EDS were employed to detect distinct features of TMCM. Copper(Ⅱ) was used to test the adsorption performance of TMCM. The experimental results indicated that TMCM exhibited higher adsorption capacity(q_e= 60.6 mg g_(-1)) and faster adsorption rate than that non-modified chitosan microsphere(NMCM).The adsorption kinetic was described well by the pseudo-second order kinetic model, which suggested that chemical adsorption along with electrons transferring was dominant in adsorption process.展开更多
Allele specific expression is essential for cellular programming and development and the diversity of cellular phenotypes. Traditional analysis methods utilize RNA and depend on single nucleotide polymorphisms,thus to...Allele specific expression is essential for cellular programming and development and the diversity of cellular phenotypes. Traditional analysis methods utilize RNA and depend on single nucleotide polymorphisms,thus to suffer from limited amount of materials for analysis. The rapid development of next-generation sequencing technologies provides more comprehensive and powerful approaches to analyze the genomic, epigenetic, and transcriptomic data, and further to detect and measure allele specific expressions. It will potentially enhance the understanding of the allele specific expressions, their complexities, and the effect on biological processes. In this paper, we extensively review the state-of-art enabling technologies and tools to analyze, detect, and measure allele specific expressions, compare their features, and point out the future trend of the methods.展开更多
The present water pollution situation at watershed level in China has been systematically analyzed.The causes of water pollution are attributed to the extensive economic developmental pattern,poor wastewater treatment...The present water pollution situation at watershed level in China has been systematically analyzed.The causes of water pollution are attributed to the extensive economic developmental pattern,poor wastewater treatment,and a lack of nonpoint pollution control.The problems of water pollution control at watershed level include a lack of thought and approach,developmental delay in the environmental standard system,an inadequate monitoring ability,and an inefficient implementation of laws and regulations.From 2006 to 2020,water pollution control and governance will be a national key specific project of science and technology in China.The strategies of this project include establishing a water pollution control system at watershed level,orienting a healthy aquatic ecosystem,conducting risk management,and using comprehensive methods.The goal is to establish and complete a technological system of pollution control and management in three five-year phases.The main tasks are to develop common technologies,management systems,and mechanisms for lake eutrophication control,river pollution control,urban water environmental pollution control,potable water safety,and water environmental management.The bottlenecks of water pollution control and management in China could be systematically removed,and the demonstration of the system engineering approach will be conducted at selected key watersheds.展开更多
We propose a systematic method to deduce and synthesize the Dafny programs.First,the specification of problem is described in strict mathematical language.Then,the derivation process uses program specification transfo...We propose a systematic method to deduce and synthesize the Dafny programs.First,the specification of problem is described in strict mathematical language.Then,the derivation process uses program specification transformation technology to perform equivalent transformation.Furthermore,Dafny program is synthesized through the obtained recursive relationship and loop invariants.Finally,the functional correctness of Dafny program is automatically verified by Dafny verifier or online tool.Through this method,we deduce and synthesize Dafny programs for many typical problems such as the cube sum problem,the minimum(or maximum)contiguous subarray problems,several searching problems,several sorting problems,and so on.Due to space limitation,we only illustrate the development process of Dafny programs for two typical problems:the minimum contiguous subarray problem and the new local bubble sorting problem.It proves that our method can effectively improve the correctness and reliability of Dafny program developed.What’s more,we demonstrate the potential of the deductive synthesis method by developing a new local bubble Sorting program.展开更多
文摘The use of improved high yielding crop varieties is an important avenue for reducing hunger and food insecurity in developing countries. Using cross-sectional data obtained from a survey conducted during 2013 crop season, we performed a probit model (plot-level analysis) to determine the probability of adopting new improved rice varieties (NIRVs) by smallholder farmers particularly from two main agro-ecological regions (hills and tropical plain terai regions) of Central Nepal. The results revealed that education, extension services and seed access play significant roles in adoption decisions. Additionally, farm and field characteristic variables such as farm size, endowment of favorable land type (e.g. lowlands), and animal power (e.g. oxen) are the key factors influencing the probability of adopting NIRVs. The results showed that technology specific variables (e.g. yield potential and acceptability) are significant for explaining adoption behavior, implying that it is important to take farmers' preferences to varietal characteristics into consideration in the design of a research and development program. Given the significant role played by extension and access related variables, increased emphasis on information dissemination, field demonstration, and farmers' participatory research and training programs to popularize new rice varieties and enhance their adoption rate are required. This also suggests that policy intervention should be made on improving the educational status of farming households, and developing programs on varietal package of rice seed which offer farmers a variety of choices among the appropriate pools of germplasm. Such programs ultimately help farmers develop more profit-oriented behavior which are necessary to enhance adoption rate, production and food security in the long run.
基金support by National Basic Research Program of China(No.2014CB748500)National Natural Science Foundation of China(Nos.51578239,51322805)
文摘An improved biosorbent of thiourea modified chitosan microsphere(TMCM) with high specific surface,favorable mechanical strength and excellent adsorption performance had been synthesized via microfluidic technology. Polyethylene glycol was used as a significant component added in aqueous solution of chitosan to produce such microspheres through droplets forming, chemical crosslinking and pores creating. For the improvement of adsorption capacity, thiourea was considered as an excellent choice in increasing amino functional group by graft modification. The SEM, FTIR and EDS were employed to detect distinct features of TMCM. Copper(Ⅱ) was used to test the adsorption performance of TMCM. The experimental results indicated that TMCM exhibited higher adsorption capacity(q_e= 60.6 mg g_(-1)) and faster adsorption rate than that non-modified chitosan microsphere(NMCM).The adsorption kinetic was described well by the pseudo-second order kinetic model, which suggested that chemical adsorption along with electrons transferring was dominant in adsorption process.
文摘Allele specific expression is essential for cellular programming and development and the diversity of cellular phenotypes. Traditional analysis methods utilize RNA and depend on single nucleotide polymorphisms,thus to suffer from limited amount of materials for analysis. The rapid development of next-generation sequencing technologies provides more comprehensive and powerful approaches to analyze the genomic, epigenetic, and transcriptomic data, and further to detect and measure allele specific expressions. It will potentially enhance the understanding of the allele specific expressions, their complexities, and the effect on biological processes. In this paper, we extensively review the state-of-art enabling technologies and tools to analyze, detect, and measure allele specific expressions, compare their features, and point out the future trend of the methods.
基金the project of the National Key Specific Project of Science and Technology of China for“Water Pollution Control and Governance,”“Functional zoning of river basin water ecology and water quality target oriented management technology”(Grant No.2008ZX07526).
文摘The present water pollution situation at watershed level in China has been systematically analyzed.The causes of water pollution are attributed to the extensive economic developmental pattern,poor wastewater treatment,and a lack of nonpoint pollution control.The problems of water pollution control at watershed level include a lack of thought and approach,developmental delay in the environmental standard system,an inadequate monitoring ability,and an inefficient implementation of laws and regulations.From 2006 to 2020,water pollution control and governance will be a national key specific project of science and technology in China.The strategies of this project include establishing a water pollution control system at watershed level,orienting a healthy aquatic ecosystem,conducting risk management,and using comprehensive methods.The goal is to establish and complete a technological system of pollution control and management in three five-year phases.The main tasks are to develop common technologies,management systems,and mechanisms for lake eutrophication control,river pollution control,urban water environmental pollution control,potable water safety,and water environmental management.The bottlenecks of water pollution control and management in China could be systematically removed,and the demonstration of the system engineering approach will be conducted at selected key watersheds.
基金Supported by the National Natural Science Foundation of China(61762049,61862033,61902162,11804133)Natural Science Foundation of Jiangxi Province(20202BABL202025,20202BABL202026,20202BAB202015)。
文摘We propose a systematic method to deduce and synthesize the Dafny programs.First,the specification of problem is described in strict mathematical language.Then,the derivation process uses program specification transformation technology to perform equivalent transformation.Furthermore,Dafny program is synthesized through the obtained recursive relationship and loop invariants.Finally,the functional correctness of Dafny program is automatically verified by Dafny verifier or online tool.Through this method,we deduce and synthesize Dafny programs for many typical problems such as the cube sum problem,the minimum(or maximum)contiguous subarray problems,several searching problems,several sorting problems,and so on.Due to space limitation,we only illustrate the development process of Dafny programs for two typical problems:the minimum contiguous subarray problem and the new local bubble sorting problem.It proves that our method can effectively improve the correctness and reliability of Dafny program developed.What’s more,we demonstrate the potential of the deductive synthesis method by developing a new local bubble Sorting program.