The challenge Africa faces the most is how to feed the 2.4 billion people in 2050. This will require a transformational agriculture. Africa doesn’t need subsistence agriculture, but rather agriculture linked to the m...The challenge Africa faces the most is how to feed the 2.4 billion people in 2050. This will require a transformational agriculture. Africa doesn’t need subsistence agriculture, but rather agriculture linked to the market where market demand and the consuming habits are taken in consideration. Agriculture evolves in an environment where small holders are linked to markets (national and regional), where economies of complementarity and economies of scale are taken advantage of by producers and private sector. In short, Africa will need a paradigm shift to industrialise and commercialise its agriculture sector in order to increase food production, and income and to create jobs in and outside the sector. Africa needs agribusiness and agro-industries to domesticate the benefits of the sector, to create wealth in the sector and retain that wealth in the continent. Agricultural commodities regional value chains for increased food should be the target for Africa. The continent remains the region with the highest prevalence of under-nourishment. Since agriculture remains the mainstay of most African economies except the mineral producers, the sector deserves a close attention from leaders. It accounts for 65% of employment and 40% of Africa’s export earnings and accounts for 17% of the GDP. This shows how important the sector is. Agriculture needs to be seen as a conduit for farmers to get connected to markets, a conduit for revenue, for jobs and for transformation. Africa needs to come back on the international scene as food sufficient continent and even food exporter. This can be achieved only with a stable, productive agricultural resource base. Thus, achieving and sustaining food security and economic prosperity in Africa will require significant efforts to modernize the continent’s agriculture sector through injection of agribusiness and agro-industries and through the application of science and technology in agriculture. In essence, agriculture needs to be viewed as knowledge based entrepreneurial activity. Smart investments in agriculture will have multiplier effects for the whole economy and hence induce prosperity to other sectors. In recent years, a renewed focus on agriculture has been evident in policy and development agendas across the African continent. This paper outlines the status of agriculture, agribusiness and agro-industries in Africa, their role in the agenda of agricultural transformation and economic transformation and the focus on regional value chain to increase food production, transformation and trade. The paper adopts a new thinking in agriculture, which reflects a regional value chain approach. The author covers such issues as: need for agricultural transformation, the role of value chain in agricultural sector, the need for regional value chain for increased income and increased food, the role of markets and the common denominator of all, the regional integration to push forward the African agriculture agenda. Evidence shows that it is agricultural growth, through its leverage effects on the rest of the economy that typically enables poor countries, poor regions and ultimately poor households to take the first steps toward economic transformation. Therefore agricultural productivity, at the small holder’s level, has the potential to lift millions of Africa’s vulnerable out of poverty and provide sustainable jobs. Other factors, namely “the rapid urbanization” and “increased population growth”, are quoted to be of critical importance. Africa population is projected to double, attaining the 2.3 billion people mark over the next 40 years representing half of the globe’s total population. This could trigger competition for resources and can have devastating effects on natural resources if not rightly channelled.展开更多
Based on the research on regional industrial chain innovation and development in the context of Guangzhou-Foshan City,this paper examines the industrial complementarity between Guangzhou and Foshan and finds that whil...Based on the research on regional industrial chain innovation and development in the context of Guangzhou-Foshan City,this paper examines the industrial complementarity between Guangzhou and Foshan and finds that while Guangzhou-Foshan City is developing,there are still some issues,such as the homogenization and competition of industrial development,a lack of profound integration of industrial chain with innovation chain,and the need to optimize the innovative coordination system.Finally,it proposes some countermeasures to promote the innovation and development of Guangzhou-Foshan regional industrial chain from several aspects,including implementing regional advanced industrial base and modern industrial chain,promoting the deep integration of industrial chain with innovation chain,and optimizing the spatial layout of collaborative innovation.展开更多
The heavy chain variable region genes of 5 human polyreactive mAbs generated in our laboratory have been cloned and sequenced using polymerase chain reaction (PCR) technique. We found that 2 and 3 mAbs utilized genes ...The heavy chain variable region genes of 5 human polyreactive mAbs generated in our laboratory have been cloned and sequenced using polymerase chain reaction (PCR) technique. We found that 2 and 3 mAbs utilized genes of the VHIV and VHIII families, respectively. The former 2 VH segments were in germline configuration. A common VH segment, with the best similarity of 90.1 % to the published VHIII germline genes, was utilized by 2 different rearranged genes encoding the V regions of other 3 mAbs. This strongly suggests that the common VH segment is a unmutated copy of an unidentified germline VHIII gene. All these polyreactive mAbs displayed a large NDN region (VH-D-JH junction). The entire H chain V regions of these polyreactive mAbs are unusually basic. The analysis of the charge properties of these mAbs as well as those of other poly- and mono- reactive mAbs from literatures prompts us to propose that the charged amino acids with a particular distribution along the H chain V region,especially the binding sites (CDRs), may be an important structural feature involved in antibody polyreactivity.展开更多
In the bone marrow and spleen,the developing B cell populations undergo both negative and positive selections to shape their B cell receptor repertoire.To gain insight into the shift of the immunoglobulin heavy(IgH)ch...In the bone marrow and spleen,the developing B cell populations undergo both negative and positive selections to shape their B cell receptor repertoire.To gain insight into the shift of the immunoglobulin heavy(IgH)chain repertoire during B cell development,we undertook large scale Igμchain repertoire analysis of pre-B,immature B and spleen B cell populations.We found that the majority of VH gene segments,VH families,JH and D gene segments,were observed to have significantly different usage frequencies when three B cell populations were compared,but the usage profile of the VH,D,and JH genes between different B cell populations showed high correlations.In both productive and nonproductive rearrangements,the length of CDRH3 shortened significantly on average when B cells entered the periphery.However,the CDRH3 length distribution of nonproductive rearrangements did not follow a Gaussian distribution,but decreased successively in the order 3n–2,3n–1 and 3n,suggesting a direct correlation between mRNA stability and CDRH3 length patterns of nonproductive rearrangements.Further analysis of the individual components comprising CDRH3 of productive rearrangements indicated that the decrease in CDRH3 length was largely due to the reduction of N addition at the 5′and 3′junctions.Moreover,with development,the amino acid content of CDRH3 progressed toward fewer positively charged and nonpolar residues but more polar residues.All these data indicated that the expressed Igμchain repertoire,especially the repertoire of CDRH3,was fine-tuned when B cells passed through several checkpoints of selection during the process of maturation.展开更多
文摘The challenge Africa faces the most is how to feed the 2.4 billion people in 2050. This will require a transformational agriculture. Africa doesn’t need subsistence agriculture, but rather agriculture linked to the market where market demand and the consuming habits are taken in consideration. Agriculture evolves in an environment where small holders are linked to markets (national and regional), where economies of complementarity and economies of scale are taken advantage of by producers and private sector. In short, Africa will need a paradigm shift to industrialise and commercialise its agriculture sector in order to increase food production, and income and to create jobs in and outside the sector. Africa needs agribusiness and agro-industries to domesticate the benefits of the sector, to create wealth in the sector and retain that wealth in the continent. Agricultural commodities regional value chains for increased food should be the target for Africa. The continent remains the region with the highest prevalence of under-nourishment. Since agriculture remains the mainstay of most African economies except the mineral producers, the sector deserves a close attention from leaders. It accounts for 65% of employment and 40% of Africa’s export earnings and accounts for 17% of the GDP. This shows how important the sector is. Agriculture needs to be seen as a conduit for farmers to get connected to markets, a conduit for revenue, for jobs and for transformation. Africa needs to come back on the international scene as food sufficient continent and even food exporter. This can be achieved only with a stable, productive agricultural resource base. Thus, achieving and sustaining food security and economic prosperity in Africa will require significant efforts to modernize the continent’s agriculture sector through injection of agribusiness and agro-industries and through the application of science and technology in agriculture. In essence, agriculture needs to be viewed as knowledge based entrepreneurial activity. Smart investments in agriculture will have multiplier effects for the whole economy and hence induce prosperity to other sectors. In recent years, a renewed focus on agriculture has been evident in policy and development agendas across the African continent. This paper outlines the status of agriculture, agribusiness and agro-industries in Africa, their role in the agenda of agricultural transformation and economic transformation and the focus on regional value chain to increase food production, transformation and trade. The paper adopts a new thinking in agriculture, which reflects a regional value chain approach. The author covers such issues as: need for agricultural transformation, the role of value chain in agricultural sector, the need for regional value chain for increased income and increased food, the role of markets and the common denominator of all, the regional integration to push forward the African agriculture agenda. Evidence shows that it is agricultural growth, through its leverage effects on the rest of the economy that typically enables poor countries, poor regions and ultimately poor households to take the first steps toward economic transformation. Therefore agricultural productivity, at the small holder’s level, has the potential to lift millions of Africa’s vulnerable out of poverty and provide sustainable jobs. Other factors, namely “the rapid urbanization” and “increased population growth”, are quoted to be of critical importance. Africa population is projected to double, attaining the 2.3 billion people mark over the next 40 years representing half of the globe’s total population. This could trigger competition for resources and can have devastating effects on natural resources if not rightly channelled.
基金The school-level academic fund general project“Research on Innovation and Development of Regional Industrial Chain Under the Background of Guangzhou-Foshan City”(Project Number:xsjj202114zsb20)。
文摘Based on the research on regional industrial chain innovation and development in the context of Guangzhou-Foshan City,this paper examines the industrial complementarity between Guangzhou and Foshan and finds that while Guangzhou-Foshan City is developing,there are still some issues,such as the homogenization and competition of industrial development,a lack of profound integration of industrial chain with innovation chain,and the need to optimize the innovative coordination system.Finally,it proposes some countermeasures to promote the innovation and development of Guangzhou-Foshan regional industrial chain from several aspects,including implementing regional advanced industrial base and modern industrial chain,promoting the deep integration of industrial chain with innovation chain,and optimizing the spatial layout of collaborative innovation.
文摘The heavy chain variable region genes of 5 human polyreactive mAbs generated in our laboratory have been cloned and sequenced using polymerase chain reaction (PCR) technique. We found that 2 and 3 mAbs utilized genes of the VHIV and VHIII families, respectively. The former 2 VH segments were in germline configuration. A common VH segment, with the best similarity of 90.1 % to the published VHIII germline genes, was utilized by 2 different rearranged genes encoding the V regions of other 3 mAbs. This strongly suggests that the common VH segment is a unmutated copy of an unidentified germline VHIII gene. All these polyreactive mAbs displayed a large NDN region (VH-D-JH junction). The entire H chain V regions of these polyreactive mAbs are unusually basic. The analysis of the charge properties of these mAbs as well as those of other poly- and mono- reactive mAbs from literatures prompts us to propose that the charged amino acids with a particular distribution along the H chain V region,especially the binding sites (CDRs), may be an important structural feature involved in antibody polyreactivity.
基金This work was supported by the National Basic Research Program of China(2010CB945300).
文摘In the bone marrow and spleen,the developing B cell populations undergo both negative and positive selections to shape their B cell receptor repertoire.To gain insight into the shift of the immunoglobulin heavy(IgH)chain repertoire during B cell development,we undertook large scale Igμchain repertoire analysis of pre-B,immature B and spleen B cell populations.We found that the majority of VH gene segments,VH families,JH and D gene segments,were observed to have significantly different usage frequencies when three B cell populations were compared,but the usage profile of the VH,D,and JH genes between different B cell populations showed high correlations.In both productive and nonproductive rearrangements,the length of CDRH3 shortened significantly on average when B cells entered the periphery.However,the CDRH3 length distribution of nonproductive rearrangements did not follow a Gaussian distribution,but decreased successively in the order 3n–2,3n–1 and 3n,suggesting a direct correlation between mRNA stability and CDRH3 length patterns of nonproductive rearrangements.Further analysis of the individual components comprising CDRH3 of productive rearrangements indicated that the decrease in CDRH3 length was largely due to the reduction of N addition at the 5′and 3′junctions.Moreover,with development,the amino acid content of CDRH3 progressed toward fewer positively charged and nonpolar residues but more polar residues.All these data indicated that the expressed Igμchain repertoire,especially the repertoire of CDRH3,was fine-tuned when B cells passed through several checkpoints of selection during the process of maturation.