182 research outputs found
Evolution of Crop-dairy Production Systems in South India from 1971 to 2002
It is widely believed that not only a Green Revolution in a crop sector but also a White Revolution in a dairy sector has generated the great momentum of agricultural development in India since the late 1960s. However, due to the dominance of sector-specific analyses, the importance of the interaction between these two sectors has been neglected in the existing literature. The interaction is important in that the dairy sector provides manure to crop production while the crop sector supplies fodder to the dairy. Using household data collected in Tamil Nadu, India for three decades from 1971, we show the increase of fodder production as a byproduct of Green Revolution in 1970s enabled subsequent White Revolution in 1980s and the byproduct of the White Revolution, i.e. increased manure availability, is enhancing the recent revival of organic farming system for sustainable agricultural development.Green revolution, White revolution, agricultural system, India, Production Economics, M3, O13, Q12, Q13, Q56,
The Dissemination of Private Wells and Double Tragedies: The Overexploitation of Groundwater among Well Users and Increased Poverty among Non-Well Users in Tamil Nadu, India
This paper investigates the impact of the dissemination of modern irrigation systems, i.e. private wells with pumps, on the livelihood not only among the farmers who have access to wells but also among the farmers who have no access to wells and thus rely solely on traditional irrigation systems called tank irrigation systems. The analysis is based on a village and household data set collected in Tamil Nadu, India where tank irrigation systems have been managed collectively for rice cultivation. Our statistical analyses predict that once declines in collective management occur due to the dissemination of private wells, the rice yield and income of the no-well-access farmers alone will decrease, resulting in increased poverty among them. Our analyses also find that the dissemination leads to the overexploitation of groundwater, and thus results in no significant increase in rice profit among the well-access farmers. In this way, the dissemination of private wells creates double tragedies: not only increased poverty among the no-well-access farmers but also overexploitation and profit reduction among the well-access farmers.irrigation, well, common property, poverty, India, Resource /Energy Economics and Policy, O3, O13, Q25,
Glucose-responsive hydrogel electrode for biocompatible glucose transistor
In this paper, we propose a highly sensitive and biocompatible glucose sensor using a semiconductor-based field effect transistor (FET) with a functionalized hydrogel. The principle of the FET device contributes to the easy detection of ionic charges with high sensitivity, and the hydrogel coated on the electrode enables the specific detection of glucose with biocompatibility. The copolymerized hydrogel on the Au gate electrode of the FET device is optimized by controlling the mixture ratio of biocompatible 2-hydroxyethylmethacrylate (HEMA) as the main monomer and vinylphenylboronic acid (VPBA) as a glucose-responsive monomer. The gate surface potential of the hydrogel FETs shifts in the negative direction with increasing glucose concentration from 10 ÎĽM to 40 mM, which results from the increase in the negative charges on the basis of the diol-binding of PBA derivatives with glucose molecules in the hydrogel. Moreover, the hydrogel coated on the gate suppresses the signal noise caused by the nonspecific adsorption of proteins such as albumin. The hydrogel FET can serve as a highly sensitive and biocompatible glucose sensor in in vivo or ex vivo applications such as eye contact lenses and sheets adhering to the skin
The possibility of a rice green revolution in large-scale irrigation schemes in Sub-Saharan Africa
This paper investigates the potential of and constraints to a rice Green Revolution in Sub-Saharan Africa's large-scale irrigation schemes, using data from Uganda, Mozambique, Burkina Faso, Mali, Niger, and Senegal. The authors find that adequate irrigation, chemical fertilizer, and labor inputs are the key to high productivity. Chemical fertilizer is expensive in Uganda and Mozambique and is barely used. This is aggravated when water access is limited because of the complementarities between fertilizer and irrigation. Meanwhile, in the schemes located in four countries in West Africa's Sahel region, where water access is generally good and institutional support for chemical fertilizer exists, rice farmers achieve attractive yields. Some countries'wage rate is high and thus mechanization could be one solution for this constraint. Improvement of credit access also facilitates the purchase of expensive fertilizer or the employment of hired labor.Crops&Crop Management Systems,Irrigation and Drainage,Water Supply and Systems,Regional Economic Development,Water and Industry
Can Africa replicate Asia's green revolution in rice ?
Asia's green revolution in rice was transformational and improved the lives of millions of poor households. Rice has become an increasingly important part of African diets and imports of rice have grown. Agronomists point out that large areas in Africa are well suited for rice and are encouraged by the field tests of new rice varieties. So is Africa poised for its own green revolution in rice? This study reviews the recent literature on rice technologies and their impact on productivity, incomes, and poverty, and compares current conditions in Africa with the conditions that prevailed in Asia as its rice revolution got under way. An important conclusion is that, to a degree, a rice revolution has already begun in Africa. Moreover, many of the same practices that have proved successful in Asia and in Africa can be applied where yields are currently low. At the same time, for many reasons, Africa's rice revolution has been, and will continue to be, characterized by a mosaic of successes, situated where the conditions are right for new technologies to take hold. This can have profound effects in some places. But because diets, markets, and geography are heterogeneous in Africa, the successful transformation of the Africa's rice sector must be matched by productivity gains in other crops to fully launch Africa's Green Revolution.Agricultural Research,Crops&Crop Management Systems,Climate Change and Agriculture,Food&Beverage Industry,Agricultural Knowledge&Information Systems
Catecholamine Detection Using a Functionalized Poly(L-dopa)-Coated Gate Field-Effect Transistor
A highly sensitive catecholamine (CA) sensor was created using a biointerface layer composed of a biopolymer and a potentiometric detection device. For the detection of CAs, 3-aminophenylboronic acid (3-NH2-PBA) was reacted with the carboxyl side chain of L-3,4-dihydroxyphenylalanine (L-dopa, LD) and the PBA-modified L-dopa was directly copolymerized with LD on an Au electrode, resulting in a 3.5 nm thick PBA-modified poly(PBA–LD/LD) layer-coated Au electrode. By connecting the PBA–LD-coated Au electrode to a field-effect transistor (FET), the molecular charge changes at the biointerface of the Au electrode, which was caused by di-ester binding of the PBA–CA complex, were transduced into gate surface potential changes. Effective CAs included LD, dopamine (DA), norepinephrine (NE), and epinephrine (EP). The surface potential of the PBA–LD-coated Au changed after the addition of 40 nM of each CA solution; notably, the PBA–LD-coated Au showed a higher sensitivity to LD because the surface potential change could already be observed after 1 nM of LD was added. The fundamental parameter analyses of the PBA–LD to CA affinity from the surface potential shift against each CA concentration indicated the highest affinity to LD (binding constant (Ks): 1.68 × 106 M–1, maximum surface potential shift (Vmax): 182 mV). Moreover, the limit of detection for each CA was 3.5 nM in LD, 12.0 nM in DA, 7.5 nM in NE, and 12.6 nM in EP. From these results, it is concluded that the poly(PBA–LD/LD)-coated gate FET could become a useful biosensor for neurotransmitters, hormones, and early detection of Parkinson’s disease
Increasing Seed System Efficiency in Africa: Concepts, Strategies and Issues
The purpose of this paper is to provide a conceptual framework that can be used by agricultural leaders, administrators, policy makers, and seed program managers to (1) understand key factors affecting seed system development; and (2) compare organizational and institutional strategies for increasing seed system effectiveness. A literature review of recent studies on seed system development in Sub-Saharan Africa (SSA) was undertaken to achieve these objectives. The studies reviewed included published and unpublished reports, monographs, and case studies.food security, food policy, Sub-Saharan Africa, seed system, Crop Production/Industries, Downloads July 2008-July 2009: 22, F0,
Biocompatible Poly(catecholamine)-Film Electrode for Potentiometric Cell Sensing
Surface-coated poly(catecholamine) (pCA) films have attracted attention as biomaterial interfaces owing to their biocompatible and physicochemical characteristics. In this paper, we report that pCA-film-coated electrodes are useful for potentiometric biosensing devices. Four different types of pCA film—L-dopa, dopamine, norepinephrine, and epinephrine—with thicknesses in the range of 7–27 nm were electropolymerized by oxidation on Au electrodes by using cyclic voltammetry. By using the pCA-film electrodes, the pH responsivities were found to be 39.3 to 47.7 mV/pH within the pH range of 1.68 to 10.01 on the basis of the equilibrium reaction with hydrogen ions and the functional groups of the pCAs. The pCA films suppressed nonspecific signals generated by other ions (Na+, K+, Ca2+) and proteins such as albumin. Thus, the pCA-film electrodes can be used in pH-sensitive and pH-selective biosensors. HeLa cells were cultivated on the surface of the pCA-film electrodes to monitor cellular activities. The surface potential of the pCA-film electrodes changed markedly because of cellular activity; therefore, the change in the hydrogen ion concentration around the cell/pCA-film interface could be monitored in real time. This was caused by carbon dioxide or lactic acid that is generated by cellular respiration and dissolves in the culture medium, resulting in the change of hydrogen concentration. pCA-film electrodes are suitable for use in biocompatible and pH-responsive biosensors, enabling the more selective detection of biological phenomena
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