74 research outputs found
THE NEW COMMONS IN AGRICULTURE: LESSONS FROM THE MARGINS AND SRI IN INDIA
N° ISBN - 978-2-7380-1284-5International audienceWith increasing evidence of the unfavourable ecological footprint of the industrialagricultural paradigm, ominous climate changes, and embarrassing social and economic crises in India manifested in farmer suicides over the last decade, there is an urgent need for India's agricultural research system to give more attention to sustainability as well as equity in innovation systems. This requires openness to acknowledging past failures and a willingness to reconfigure the research system's relations with non-research actors. This paper looks at possible lessons to guide this reconfiguration by examining the rapid and surprising spread of a novel sustainable innovation in India – the System of Rice Intensification (SRI). SRI shows how a less hierarchical and less linear architecture of innovation has enabled a new ‘knowledge commons' to emerge in Indian agriculture, contributing substantially to household-level food security, also enabling farmers to cope with vulnerabilities. Open innovation in SRI has enabled the creation of this new commons in an era when privatization of agricultural knowledge has gained sway. Rainfed areas that have been marginal to the Green Revolution are becoming more central to the establishment of sustainability regimes. This innovation has been enabled by the extensive use of the internet, based on new kinds of networking within civil society playing an important role ensuring collaboration among diverse actors from the farm to the national level. The paper highlights the importance of facilitating knowledge dialogues, learning alliances and innovation networks to enhance innovation capacities. ‘Open innovation' and the new ‘commons' have important policy implications for the future of innovation systems and sustainable development
Transcription elongation factor NusA is a general antagonist of Rho-dependent termination in Escherichia coli
NusA is an essential protein that binds to RNA polymerase and also to the nascent RNA and influences transcription by inducing pausing and facilitating the process of transcription termination/antitermination. Its participation in Rho-dependent transcription termination has been perceived, but the molecular nature of this involvement is not known. We hypothesized that, because both Rho and NusA are RNA-binding proteins and have the potential to target the same RNA, the latter is likely to influence the global pattern of the Rho-dependent termination. Analyses of the nascent RNA binding properties and consequent effects on the Rho-dependent termination functions of specific NusA-RNA binding domain mutants revealed an existence of Rho-NusA direct competition for the overlapping nut (NusA-binding site) and rut (Rho-binding site) sites on the RNA. This leads to delayed entry of Rho at the rut site that inhibits the latter's RNA release process. High density tiling microarray profiles of these NusA mutants revealed that a significant number of genes, together with transcripts from intergenic regions, are up-regulated. Interestingly, the majority of these genes were also up-regulated when the Rho function was compromised. These results provide strong evidence for the existence of NusA-binding sites in different operons that are also the targets of Rho-dependent terminations. Our data strongly argue in favor of a direct competition between NusA and Rho for the access of specific sites on the nascent transcripts in different parts of the genome. We propose that this competition enables NusA to function as a global antagonist of the Rho function, which is unlike its role as a facilitator of hairpin-dependent termination
A multipronged strategy of an anti-terminator protein to overcome Rho-dependent transcription termination
One of the important role of Rho-dependent transcription termination in bacteria is to prevent gene expressions from the bacteriophage DNA. The transcription anti-termination systems of the lambdoid phages have been designed to overcome this Rho action. The anti-terminator protein N has three interacting regions, which interact with the mRNA, with the NusA and with the RNA polymerase. Here, we show that N uses all these interaction modules to overcome the Rho action. N and Rho co-occupy their overlapping binding sites on the nascent RNA (the nutR/tR1 site) and this configuration slows down the rate of ATP hydrolysis and the rate of RNA release by Rho from the elongation complex. N-RNA polymerase interaction is not too important for this Rho inactivation process near/at the nutR site. This interaction becomes essential when the elongation complex moves away from the nutR site. From the unusual NusA-dependence property of a Rho mutant E134K, a suppressor of N, we deduced that the N-NusA complex in the anti-termination machinery reduces the efficiency of Rho by removing NusA from the termination pathway. We propose that NusA-remodelling is also one of the mechanisms used by N to overcome the termination signals
Artemisinin resistance in Plasmodium falciparum malaria.
BACKGROUND: Artemisinin-based combination therapies are the recommended first-line treatments of falciparum malaria in all countries with endemic disease. There are recent concerns that the efficacy of such therapies has declined on the Thai-Cambodian border, historically a site of emerging antimalarial-drug resistance. METHODS: In two open-label, randomized trials, we compared the efficacies of two treatments for uncomplicated falciparum malaria in Pailin, western Cambodia, and Wang Pha, northwestern Thailand: oral artesunate given at a dose of 2 mg per kilogram of body weight per day, for 7 days, and artesunate given at a dose of 4 mg per kilogram per day, for 3 days, followed by mefloquine at two doses totaling 25 mg per kilogram. We assessed in vitro and in vivo Plasmodium falciparum susceptibility, artesunate pharmacokinetics, and molecular markers of resistance. RESULTS: We studied 40 patients in each of the two locations. The overall median parasite clearance times were 84 hours (interquartile range, 60 to 96) in Pailin and 48 hours (interquartile range, 36 to 66) in Wang Pha (P<0.001). Recrudescence confirmed by means of polymerase-chain-reaction assay occurred in 6 of 20 patients (30%) receiving artesunate monotherapy and 1 of 20 (5%) receiving artesunate-mefloquine therapy in Pailin, as compared with 2 of 20 (10%) and 1 of 20 (5%), respectively, in Wang Pha (P=0.31). These markedly different parasitologic responses were not explained by differences in age, artesunate or dihydroartemisinin pharmacokinetics, results of isotopic in vitro sensitivity tests, or putative molecular correlates of P. falciparum drug resistance (mutations or amplifications of the gene encoding a multidrug resistance protein [PfMDR1] or mutations in the gene encoding sarco-endoplasmic reticulum calcium ATPase6 [PfSERCA]). Adverse events were mild and did not differ significantly between the two treatment groups. CONCLUSIONS: P. falciparum has reduced in vivo susceptibility to artesunate in western Cambodia as compared with northwestern Thailand. Resistance is characterized by slow parasite clearance in vivo without corresponding reductions on conventional in vitro susceptibility testing. Containment measures are urgently needed. (ClinicalTrials.gov number, NCT00493363, and Current Controlled Trials number, ISRCTN64835265.
Redundancy of primary RNA-binding functions of the bacterial transcription terminator Rho
The bacterial transcription terminator, Rho, terminates transcription at half of the operons. According to the classical model derived from in vitro assays on a few terminators, Rho is recruited to the transcription Elongation Complex (EC) by recognizing specific sites (rut) on the nascent RNA. Here, we explored the mode of in vivo recruitment process of Rho. We show that sequence specific recognition of the rut site, in majority of the Rho-dependent terminators, can be compromised to a great extent without seriously affecting the genome-wide termination function as well as the viability of Escherichia coli. These terminators function optimally only through a NusG-assisted recruitment and activation of Rho. Our data also indicate that at these terminators, Rho-EC-bound NusG interaction facilitates the isomerization of Rho into a translocase-competent form by stabilizing the interactions of mRNA with the secondary RNA binding site, thereby overcoming the defects of the primary RNA binding functions
INFLUENCE OF ORGANIC MANURES ON PRODUCTIVITY OF TWO VARIETIES OF RICE
Field experiment was conducted during 2003-04 to study the effect of vermicompost, farmyard manure and water hyacinth compost in comparison to chemically fertilized and unfertilized plots on crop-plants in HYV Swarna and local variety Magaisal. The experiment followed split plot design with two varieties of rice in the main plots and five nutrient sources randomized in sub plots. Signifi cant variation in grain yield between the varieties, among the nutrient sources and their interactions was observed. Grain yield recorded in HYV Swarna was higher to local variety Mugaisal irrespective of the treatments and hence Swarna was considered to be more tolerant to Mugaisal. Among the nutrient sources, treatment with vermicompost imparted maximum grain yield to all other nutrient sources irrespective of varieties
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