905 resultados para Cotton gins and ginning


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This thesis explores the inter-related attempts to secure the legitimation of risk and democracy with regard to Bt cotton, a genetically modified crop, in the state of Andhra Pradesh in India. The research included nine months of ethnographic fieldwork, extensive library and newspaper research, as well as university attendance in India, undertaken between June, 2010 and March, 2011. This comparative study (involving organic, NPM and Bt cotton cultivation) was conducted in three villages in Telangana, a region which was granted secession from Andhra Pradesh in July, 2013, and in Hyderabad, the state capital. Andhra Pradesh is renowned for its agrarian crisis and farmer suicides, as well as for the conflict which Bt cotton represents. This study adopts the categories of legitimation developed by Van Leeuwen (2007; 2008) in order to explore the theory of risk society (Beck, 1992; 1994; 1999; 2009), and the Habermasian (1996: 356-366) core-periphery model as means of theoretically analysing democratic legitimacy. The legitimation of risk and democracy in relation to Bt cotton refers to normative views on the way in which power should be exercised with regard to risk differentiation, construction and definition. The analysis finds that the more legitimate the exercise of power, the lower the exposure to risk as a concern for the collective. This also has consequences for the way in which resources are distributed, knowledge constructed, and democratic praxis institutionalised as a concern for social and epistemic justice. The thesis argues that the struggle to legitimate risk and democracy has implications not only for the constitution of the new state of Telangana and the region’s development, but also for the emergence of global society and the future development of humanity as a whole.

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Human respiratory syncytial virus (HRSV) is the most important viral cause of severe respiratory tract disease in infants. Two subgroups (A and B) have been identified, which cocirculate during, or alternate between, yearly epidemics and cause indistinguishable disease. Existing in vitro and in vivo models of HRSV focus almost exclusively on subgroup A viruses. Here, a recombinant (r) subgroup B virus (rHRSV(B05)) was generated based on a consensus genome sequence obtained directly from an unpassaged clinical specimen from a hospitalized infant. An additional transcription unit containing the gene encoding enhanced green fluorescent protein (EGFP) was introduced between the phosphoprotein and matrix genes (position 5) of the genome to generate rHRSV(B05)EGFP(5). The recombinant viruses replicated efficiently in both HEp-2 cells and in well-differentiated normal human bronchial cells grown at air-liquid interface. Intranasal infection of cotton rats (Sigmodon hispidus) resulted in high numbers of EGFP(+) cells in epithelia of the nasal septum and conchae. When administered in a relatively large inoculum volume, the virus also replicated efficiently in bronchiolar epithelial cells and spread extensively in both the upper and lower respiratory tracts. Virus replication was not observed in ciliated epithelial cells of the trachea. This is the first virulent rHRSV strain with the genetic composition of a currently circulating wild-type virus. In vivo tracking of infected cells by means of EGFP fluorescence in the absence of cytopathic changes increases the sensitivity of virus detection in HRSV pathogenesis studies.

IMPORTANCE

Virology as a discipline has depended on monitoring cytopathic effects following virus culture in vitro. However, wild-type viruses isolated from patients often do not cause significant changes to infected cells, necessitating blind passage. This can lead to genetic and phenotypic changes and the generation of high-titer, laboratory-adapted viruses with diminished virulence in animal models of disease. To address this, we determined the genome sequence of an unpassaged human respiratory syncytial virus from a sample obtained directly from an infected infant, assembled a molecular clone, and recovered a wild-type recombinant virus. Addition of a gene encoding enhanced green fluorescent protein allowed this wild-type virus to be tracked in primary human cells and living animals in the absence of significant cytopathic effects. Imaging of fluorescent cells proved to be a highly valuable tool for monitoring the spread of virus and may help improve assays for evaluating novel intervention strategies.

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Raman spectroscopy has been applied to characterize fiber dyes and determine the discriminating ability of the method. Black, blue, and red acrylic, cotton, and wool samples were analyzed. Four excitation sources were used to obtain complementary responses in the case of fluorescent samples. Fibers that did not provide informative spectra using a given laser were usually detected using another wavelength. For any colored acrylic, the 633-nm laser did not provide Raman information. The 514-nm laser provided the highest discrimination for blue and black cotton, but half of the blue cottons produced noninformative spectra. The 830-nm laser exhibited the highest discrimination for red cotton. Both visible lasers provided the highest discrimination for black and blue wool, and NIR lasers produced remarkable separation for red and black wool. This study shows that the discriminating ability of Raman spectroscopy depends on the fiber type, color, and the laser wavelength.

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This paper describes some of the results of a detailed farm-level survey of 32 small-scale cotton farmers in the Makhathini Flats region of South Africa. The aim was to assess and measure some of the impacts (especially in terms of savings in pesticide and labour as well as benefits to human health) attributable to the use of insect-tolerant Bt cotton. The study reveals a direct cost benefit for Bt growers of SAR416 ($51) per hectare per season due to a reduction in the number of insecticide applications. Cost savings emerged in the form of lower requirements for pesticide, but also important were reduced requirements for water and labour. The reduction in the number of sprays was particularly beneficial to women who do some spraying and children who collect water and assist in spraying. The increasing adoption rate of Bt cotton appears to have a health benefit measured in terms of reported rates of accidental insecticide poisoning. These appear to be declining as the uptake of Bt cotton increases. However, the understanding of refugia and their management by local farmers are deficient and need improving. Finally, Bt cotton growers emerge as more resilient in absorbing price fluctuations.

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The study reported presents the findings relating to commercial growing of genetically-modified Bt cotton in South Africa by a large sample of smallholder farmers over three seasons (1998/99, 1999/2000, 2000/01) following adoption. The analysis presents constructs and compares groupwise differences for key variables in Bt v. non-Bt technology and uses regressions to further analyse the production and profit impacts of Bt adoption. Analysis of the distribution of benefits between farmers due to the technology is also presented. In parallel with these socio-economic measures, the toxic loads being presented to the environment following the introduction of Bt cotton are monitored in terms of insecticide active ingredient (ai) and the Biocide Index. The latter adjusts ai to allow for differing persistence and toxicity of insecticides. Results show substantial and significant financial benefits to smallholder cotton growers of adopting Bt cotton over three seasons in terms of increased yields, lower insecticide spray costs and higher gross margins. This includes one particularly wet, poor growing season. In addition, those with the smaller holdings appeared to benefit proportionately more from the technology (in terms of higher gross margins) than those with larger holdings. Analysis using the Gini-coefficient suggests that the Bt technology has helped to reduce inequality amongst smallholder cotton growers in Makhathini compared to what may have been the position if they had grown conventional cotton. However, while Bt growers applied lower amounts of insecticide and had lower Biocide Indices (per ha) than growers of non-Bt cotton, some of this advantage was due to a reduction in non-bollworm insecticide. Indeed, the Biocide Index for all farmers in the population actually increased with the introduction of Bt cotton. The results indicate the complexity of such studies on the socio-economic and environmental impacts of GM varieties in the developing world.

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Results of a large-scale survey of resource-poor smallholder cotton farmers in South Africa over three years conclusively show that adopters of Bt cotton have benefited in terms of higher yields, lower pesticide use, less labour for pesticide application and substantially higher gross margins per hectare. These benefits were clearly related to the technology, and not to preferential adoption by farmers who were already highly efficient. The smallest producers are shown to have benefited from adoption of the Bt variety as much as, if not more than, larger producers. Moreover, evidence from hospital records suggests a link between declining pesticide poisonings and adoption of the Bt variety.

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Response of cotton (Gossypium hirsutum L. cv. NIAB-78) to salinity, in terms of seed germination, seedling root growth and root Na+ and K+ content was determined in a laboratory experiment. Cotton seeds were exposed to increasing salinity levels using germination water with Sodium chloride concentrations of 0, 50, 100, 150 and 200 mM, to provide different degrees of salt stress. Germinated seeds were counted and roots were harvested at 24, 48, 72 and 96 h after the start of the experiment. It appeared that seed germination was only slightly affected by an increase in salinity (in most cases the differences between treatment were non-significant), whereas root length, root growth rate, root fresh and dry weights were severely affected, generally highly significant differences in these variables were found for comparisons involving most combinations of salinity levels, in particular with increased incubation period. K+ contents decreased with increasing salinity levels, although differences in K+ content were only significant when comparing the control and the 4 salinity levels. Na+ content of the roots increased with increasing levels of NaCl in the germination water, suggesting an exchange of K+ for Na+. The ratio K+/Na+ strongly decreased with rising levels of salinity from around 4.5 for the control to similar to 1 at 200 mM NaCl.

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The paper reports the findings of a study designed to consider the impact of the adoption of Bt cotton on markets, businesses, and institutional arrangements in India. Given that evidence to date suggests that widespread adoption of Bt cotton by farmers is likely to increase production, this study aims to assess possible implications for markets (access to inputs, prices of inputs and outputs, etc.) and local industries and to identify potential winners and losers. The results suggest that there are impacts on the cotton industry following from the release of Bt hybrids, and so far the impacts are most noticeable "upstream" (i.e., the input suppliers), where companies are rapidly moving away from the sale of bollworm insecticide and attempting to sell Bt seeds. Seed companies are looking for partnerships with Monsanto, the owner of the Bt gene. One reason that companies are keen to move away from insecticide is so they can avoid the need for credit supply to their customers. Seed purchase is not normally through credit, whereas insecticide purchase is. Issues for companies "downstream" (gins, textile manufacturers) relate more to the better quality of Bt cotton and the need for adequate segregation of Bt and non-Bt cotton.

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Genetically modified (GM) cotton was approved for commercial cultivation in 2002. Hybrids to date have carried the Bt (Bacillus thuringiensis) gene, which confers resistance to Lepidoptera and certain Coleoptera. As well as "official" Bt hybrids (i.e., those that have gone through a formal approval process), there are "unofficial" Bt hybrids produced without such approval. The owners of the official hybrids, Monsanto-Mahyco, claim that the unofficial hybrids are not as good and could even damage the perception of Bt cotton amongst farmers. Anti-GM groups claim that neither type of Bt hybrid provides either yield or economic advantages over non-Bt hybrids. This paper reports the first study of official versus unofficial versus non-Bt hybrids in India (622 farmers in Gujarat State) with the specific aim of comparing one hypothesized ranking in terms of gross margin of (a) official Bt hybrids, (b) unofficial Bt hybrids, and (c) non-Bt hybrids. Results suggest that the official Bt varieties (MECH 12 and MECH 162) significantly outperform the unofficial varieties in terms of gross margin. However, unofficial, locally produced Bt hybrids can also perform significantly better than non-Bt hybrids, although second-generation (F2) Bt seed appears to have no yield advantage compared to non-Bt hybrids but can save on insecticide use. The paper explores some of the implications of this ranking.

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This paper describes some of the results of a detailed farm-level survey of 32 small-scale cotton farmers in the Makhathini Flats region of South Africa. The aim was to assess and measure some of the impacts (especially in terms of savings in pesticide and labour as well as benefits to human health) attributable to the use of insect-tolerant Bt cotton. The study reveals a direct cost benefit for Bt growers of SAR416 ($51) per hectare per season due to a reduction in the number of insecticide applications. Cost savings emerged in the form of lower requirements for pesticide, but also important were reduced requirements for water and labour. The reduction in the number of sprays was particularly beneficial to women who do some spraying and children who collect water and assist in spraying. The increasing adoption rate of Bt cotton appears to have a health benefit measured in terms of reported rates of accidental insecticide poisoning. These appear to be declining as the uptake of Bt cotton increases. However, the understanding of refugia and their management by local farmers are deficient and need improving. Finally, Bt cotton growers emerge as more resilient in absorbing price fluctuations.

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40.00% 40.00%

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The study reported presents the findings relating to commercial growing of genetically-modified Bt cotton in South Africa by a large sample of smallholder farmers over three seasons (1998/99, 1999/2000, 2000/01) following adoption. The analysis presents constructs and compares groupwise differences for key variables in Bt v. non-Bt technology and uses regressions to further analyse the production and profit impacts of Bt adoption. Analysis of the distribution of benefits between farmers due to the technology is also presented. In parallel with these socio-economic measures, the toxic loads being presented to the environment following the introduction of Bt cotton are monitored in terms of insecticide active ingredient (ai) and the Biocide Index. The latter adjusts ai to allow for differing persistence and toxicity of insecticides. Results show substantial and significant financial benefits to smallholder cotton growers of adopting Bt cotton over three seasons in terms of increased yields, lower insecticide spray costs and higher gross margins. This includes one particularly wet, poor growing season. In addition, those with the smaller holdings appeared to benefit proportionately more from the technology (in terms of higher gross margins) than those with larger holdings. Analysis using the Gini-coefficient suggests that the Bt technology has helped to reduce inequality amongst smallholder cotton growers in Makhathini compared to what may have been the position if they had grown conventional cotton. However, while Bt growers applied lower amounts of insecticide and had lower Biocide Indices (per ha) than growers of non-Bt cotton, some of this advantage was due to a reduction in non-bollworm insecticide. Indeed, the Biocide Index for all farmers in the population actually increased with the introduction of Bt cotton. The results indicate the complexity of such studies on the socio-economic and environmental impacts of GM varieties in the developing world.