914 resultados para Composite polymer blend. Polyethylene terephthalate. Polyethylenemethyl acrylate. And cotton linter
Resumo:
Este artículo busca describir y analizar las acciones y reacciones que generó sobre el discurso y práctica del actor social cooperativo, la crisis del cultivo algodonero durante los años '60 en la Argentina. Se toma el caso de la Cooperativa Agrícola Algodonera La Banda Limitada (CAALBA) de Santiago del Estero. Asociación de pequeños productores inserta en un entramado de relaciones con instituciones de la sociedad civil y el Estado que -en términos gramscianos- fueron compartimentos con interacción en el marco de las disputas hegemónicas sobre el proyecto de desarrollo social. Se presentan también a lo largo del trabajo a la CAALBA ante estos nuevos escenarios, así como fue la Corporación del Río Dulce
Resumo:
Este artículo busca describir y analizar las acciones y reacciones que generó sobre el discurso y práctica del actor social cooperativo, la crisis del cultivo algodonero durante los años '60 en la Argentina. Se toma el caso de la Cooperativa Agrícola Algodonera La Banda Limitada (CAALBA) de Santiago del Estero. Asociación de pequeños productores inserta en un entramado de relaciones con instituciones de la sociedad civil y el Estado que -en términos gramscianos- fueron compartimentos con interacción en el marco de las disputas hegemónicas sobre el proyecto de desarrollo social. Se presentan también a lo largo del trabajo a la CAALBA ante estos nuevos escenarios, así como fue la Corporación del Río Dulce
Resumo:
We tested the hypothesis that light activation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is inhibited by moderately elevated temperature through an effect on Rubisco activase. When cotton (Gossypium hirsutum L.) or wheat (Triticum aestivum L.) leaf tissue was exposed to increasing temperatures in the light, activation of Rubisco was inhibited above 35 and 30°C, respectively, and the relative inhibition was greater for wheat than for cotton. The temperature-induced inhibition of Rubisco activation was fully reversible at temperatures below 40°C. In contrast to activation state, total Rubisco activity was not affected by temperatures as high as 45°C. Nonphotochemical fluorescence quenching increased at temperatures that inhibited Rubisco activation, consistent with inhibition of Calvin cycle activity. Initial and maximal chlorophyll fluorescence were not significantly altered until temperatures exceeded 40°C. Thus, electron transport, as measured by Chl fluorescence, appeared to be more stable to moderately elevated temperatures than Rubisco activation. Western-blot analysis revealed the formation of high-molecular-weight aggregates of activase at temperatures above 40°C for both wheat and cotton when inhibition of Rubisco activation was irreversible. Physical perturbation of other soluble stromal enzymes, including Rubisco, phosphoribulokinase, and glutamine synthetase, was not detected at the elevated temperatures. Our evidence indicates that moderately elevated temperatures inhibit light activation of Rubisco via a direct effect on Rubisco activase.
Resumo:
Parasitic and predatory arthropods often prevent plants from being severely damaged by killing herbivores as they feed on the plants. Recent studies show that a variety of plants, when injured by herbivores, emit chemical signals that guide natural enemies to the herbivores. It is unlikely that herbivore-damaged plants initiate the production of chemicals solely to attract parasitoids and predators. The signaling role probably evolved secondarily from plant responses that produce toxins and deterrents against herbivores and antibiotics against pathogens. To effectively function as signals for natural enemies, the emitted volatiles should be clearly distinguishable from background odors, specific for prey or host species that feed on the plant, and emitted at times when the natural enemies forage. Our studies on the phenomena of herbivore-induced emissions of volatiles in corn and cotton plants and studies conducted by others indicate that (i) the clarity of the volatile signals is high, as they are unique for herbivore damage, produced in relatively large amounts, and easily distinguishable from background odors; (ii) specificity is limited when different herbivores feed on the same plant species but high as far as odors emitted by different plant species and genotypes are concerned; (iii) the signals are timed so that they are mainly released during the daytime, when natural enemies tend to forage, and they wane slowly after herbivory stops.
Resumo:
O glyphosate é o principal herbicida utilizado no manejo de plantas daninhas na agricultura, aplicado em alguns sistemas de forma repetitiva ao longo de cada ano. Esta prática selecionou biótipos resistentes de espécies de plantas daninhas, sendo o capim-amargoso (Digitaria insularis) selecionado no Brasil. Portanto, se tornam necessários estudos para entender, manejar e reduzir a infestação do capim-amargoso resistente ao glyphosate. Dessa forma, esta pesquisa foi desenvolvida com os objetivos de: (i) mapear áreas do Brasil com possíveis infestações de capim-amargoso resistente ao glyphosate; (ii) avaliar alternativas químicas de seu manejo; (iii) elucidar os mecanismos de resistência ao glyphosate e; (iv) avaliar a herança genética dos genes que conferem resistência ao glyphosate. Para o desenvolvimento dos experimentos foram coletadas sementes de biótipos potencialmente resistentes de diversas regiões do Brasil onde ocorreram falhas de controle de D. insularis após a aplicação de glyphosate. Na primeira etapa da pesquisa foram realizados experimentos para determinação de uma dose discriminatória de triagementre as populações resistentes e suscetíveis ao glyphosate, através de curvas de dose-resposta, para identificar a resistência ao Glyphosate, sendo que estes dados foram utilizados para mapear a ocorrência de biótipos resistentes em algumas regiões do país. Na segunda etapa foi conduzido um experimento em casa-de-vegetação visando encontrar herbicidas alternativos ao Glyphosate para controle do capim-amargoso, utilizando herbicidas recomendados para as culturas do milho e algodão, tanto em condições de aplicação de pré como em pós-emergência da planta daninha. Na terceira etapa foram realizados ensaios para determinar a existência de absorção e translocação diferencial do glyphosate em biótipos suscetíveis e resistentes, juntamente com a análise molecular para comparar a região 106 do gene que codifica a EPSPs nestes biótipos. Por fim um estudo de polinização cruzada foi conduzido para avaliar se genes de resistência ao glyphosate são transferidos para a geração seguinte após inflorescências de biótipos suscetíveis serem acondicionadas com as de biótipos resistentes, submetendo a geração seguinte a experimentos de curva de dose-resposta com o glyphosate. Através do modelo de curva dose-resposta do programa estatístico R, determinou-se a dose de 960 g e.a ha-1, como a dose utilizada para triagem dos biótipos oriundos de diferentes regiões do Brasil. Com isto foram gerados mapas indicando a presença ou ausência de resistência ao herbicida, sendo que as região oeste do Paraná e sul do Mato Grosso do Sul apresentam maior número de localidades com a presença de biótipos resistentes. As alternativas de controle viáveis como pós-emergentes no estádio de um a dois perfilhos, foram os herbicidas Nicosulfuron, Imazapic + Imazapyr, Atrazine, Haloxifop-methyl e Tepraloxydim. Na pré-emergência do capim-amargoso os herbicidas Atrazine, Isoxaflutole, S-metolachlor, Clomazone, Diuron e Flumioxazin se apresentaram como eficazes para o controle desta espécie. Os resultados do experimento de absorção, translocação e comparação da região 106 não mostraram diferenças entre os biótipos resistente e suscetível. O experimento sobre cruzamento entre biótipos resistente e suscetível determinou a espécie D. insularis como autógama e sem transferência de genes que causam a resistência ao glyphosate.
Resumo:
Plantas transgênicas que expressam toxinas de Bacillus thuringiensis Berliner (Bt) têm sido amplamente utilizadas para o controle de Spodoptera frugiperda (J. E. Smith) no Brasil. Entretanto, a evolução da resistência é um dos maiores entraves para a continuidade do uso desta tecnologia. Para subsidiar programas de Manejo da Resistência de Insetos (MRI), foram conduzidos estudos para o aprimoramento dos programas de manejo da resistência de S. frugiperda a tecnologias Bt. Foram realizadas estudos para determinar a dominância funcional da resistência de S. frugiperda a tecnologias Bt mediante a avaliação da sobrevivência de larvas neonatas provenientes das linhagens de S. frugiperda resistentes ao milho Herculex® que expressa a proteína Cry1F (HX-R), ao milho YieldGard VT PRO™ que expressa as proteínas Cry1A.105 e Cry2Ab2 (VT-R), ao milho PowerCore™ que expressa as proteínas Cry1A.105, Cry2Ab2 e Cry1F (PW-R), e ao milho Agrisure Viptera™ que expressa a proteína Vip3Aa20 (Vip-R), além da linhagem suscetível (Sus) e de suas respectivas linhagens heterozigotas em diversas tecnologias de milho e algodão Bt. Posteriormente, um método prático para o monitoramento fenotípico da suscetibilidade a diferentes tecnologias de milho e algodão Bt foi testado a partir da avaliação da sobrevivência de larvas neonatas em folhas de plantas Bt em populações de S. frugiperda provenientes dos Estados do Rio Grande do Sul, Paraná, São Paulo, Goiás e Bahia na safra agrícola 2014/15. E por último, a estimativa da frequência de alelos de resistência de S. frugiperda a Vip3Aa20 foi validada pelo método de F1 screen. Em geral, observou-se alta mortalidade dos heterozigotos nas tecnologias Bt testadas, comprovando que a resistência de S. frugiperda a proteínas Bt é funcionalmente recessiva o que suporta a estratégia de refúgio em programas de MRI. Verificou-se também que linhagens resistentes a eventos que expressam proteínas Cry não sobrevivem em tecnologias que expressam proteína Vip. No monitoramento prático da suscetibilidade a tecnologias Bt, sobrevivência larval superior a 70% foi observada para populações de campo do Paraná, Goiás e Bahia no milho Herculex®. Em tecnologias de milho PowerCore™ e YieldGard VT PRO™ houve sobrevivência larval variando de 1,1 a 17,9%. Em contraste, não houve sobreviventes em tecnologias de milho Viptera™. Em algodão WideStrike® que expressa as proteínas Cry1Ac e Cry1F, sobrevivência acima de 41% foi observada para populações de campo de S. frugiperda. A sobrevivência larval em Bollgard II® que expressa as proteínas Cry1Ac e Cry2Ab2 variou de 14 a 40%. No algodão TwinLink® que expressa as proteínas Cry1Ab e Cry2Ae, a sobrevivência larval das populações foi menor que 20%. O método de F1 screen foi eficiente na detecção de alelos de resistência a Vip3Aa20 em populações de S. frugiperda provenientes de diferentes regiões produtoras de milho no Brasil na safra 2014/2015. De 263 isofamílias testadas, foram detectadas três isofamílias positivas oriundas do Paraná, Mato Grosso e Goiás. A frequência de resistência estimada a Vip3Aa20 variou de 0,0140 a 0,0367 nas populações avaliadas, sendo que a frequência total foi de 0,0076. Neste estudo, fornecemos informações para refinar as estratégias de MRI, além de introduzir novas técnicas para monitorar a resistência de S. frugiperda a tecnologias Bt no Brasil.
Resumo:
En el siguiente trabajo se realiza la impregnación de diferentes sustratos poliméricos con agentes biocidas y con un colorante textil, comúnmente empleados en los procesos de acabados textiles. En este estudio se realiza la selección del colorante Disperse Red 167 (DR167), mediante la comparación de solubilidad en CO2 supercrítico (scCO2) entre varios colorantes dispersos. Los agentes biocidas seleccionados han sido; esencia de clavo (eugenol) y aceite esencial de orégano. Se ha realizado la impregnación de diferentes sustratos poliméricos; poliéster (PES), polipropileno (PP), y algodón (CO), en diferentes condiciones. En total se realizaron impregnaciones utilizando diez concentraciones relativas del DR167. El objetivo principal es determinar las condiciones óptimas de procesado para cada sustrato. Para determinar el rendimiento de la tintura en scCO2 se han representado los diagramas cromáticos de las muestras tintadas en diferentes condiciones. Las muestras de PES son las que presentan mayor rendimiento de color, sabiendo que esta es la única fibra que presenta afinidad con el DR167. Para determinar el efecto de inhibición de las bacterias se han realizado ensayos de actividad antimicrobiana y actividad fungicida. Puede indicarse que sí se observó cierta actividad inhibitoria frente algunos microorganismos, como Staphylococcus aureus, mientras que no se observó una actividad inhibitoria importante frente a otros como Pseudomonas aeruginosa.
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: Map of the city of New Orleans showing location of exposition grounds and all approaches thereto by land & water, [by] the World's Industrial and Cotton Centennial Exposition, New Orleans, La., U.S.A., Department of Installation. It was published by The Exposition ca. 1884. Scale [ca. 1:2,000]. Covers also adjacent portions of Jefferson and St. Bernard Parishes. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Louisiana State Plane Coordinate System, South NAD83 (in Feet) (Fipszone 1702). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, or other information associated with the principal map. This map shows features such as exposition grounds, railroads, roads, canals, levees, drainage, block numbers, land ownership in outlying areas, selected public and industrial buildings, cemeteries, Parish boundaries, ferry routes, and more. Depths shown by soundings. Includes inset views, plans, and engravings: Perspective view of the buildings and grounds from the Northeast -- Mexican national headquarters -- Grand Rapids (Mich.) furniture pavilion -- [South pass] -- View of New Orleans in 1719 -- Railroad map of Louisiana and Texas -- Plan of New Orleans in 1770 by Capt.n Pittman of the British Army -- Ground plan -- United States and state exhibits -- Art gallery -- Main building -- Factories and Mills -- Horticultural hall. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection as part of the Imaging the Urban Environment project. Maps selected for this project represent major urban areas and cities of the world, at various time periods. These maps typically portray both natural and manmade features at a large scale. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.
Resumo:
We tested the hypothesis that light activation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is inhibited by moderately elevated temperature through an effect on Rubisco activase. When cotton (Gossypium hirsutum L.) or wheat (Triticum aestivum L.) leaf tissue was exposed to increasing temperatures in the light, activation of Rubisco was inhibited above 35 and 30°C, respectively, and the relative inhibition was greater for wheat than for cotton. The temperature-induced inhibition of Rubisco activation was fully reversible at temperatures below 40°C. In contrast to activation state, total Rubisco activity was not affected by temperatures as high as 45°C. Nonphotochemical fluorescence quenching increased at temperatures that inhibited Rubisco activation, consistent with inhibition of Calvin cycle activity. Initial and maximal chlorophyll fluorescence were not significantly altered until temperatures exceeded 40°C. Thus, electron transport, as measured by Chl fluorescence, appeared to be more stable to moderately elevated temperatures than Rubisco activation. Western-blot analysis revealed the formation of high-molecular-weight aggregates of activase at temperatures above 40°C for both wheat and cotton when inhibition of Rubisco activation was irreversible. Physical perturbation of other soluble stromal enzymes, including Rubisco, phosphoribulokinase, and glutamine synthetase, was not detected at the elevated temperatures. Our evidence indicates that moderately elevated temperatures inhibit light activation of Rubisco via a direct effect on Rubisco activase.
Resumo:
Mode of access: Internet.
Resumo:
American cotton crop movements--An address delivered at the International Convention of Cotton Spinners, Manufacturers and Cotton Growers, Atlanta, Georgia, Oct. 8, 1907 / S.T. Hubbard--An exposition of the methods of business in "cotton futures" as conducted in the New York, New Orleans and Liverpool markets / A.B. Shepperson--Nature and uses of cotton contracts--The economic position of the New York Cotton Exchange and its relation to the cotton trade / A.R. Marsh--The New York Cotton Exchange and its contract for delivery of cotton / S.T. Hubbard.
Resumo:
Preface.--Joekel, S.L. The crop mortgage system in Texas.--Haney, L.H. The need and possibility of coöperative rural credity in Texas.--Trenckmann, W. Cop̈erative agricultural credit.--Lamaster, C.E. Coöperative production by farmers.--Wythe, George. Coöperative marketing of fruit, truck and cotton, chiefly in Texas.--Voorhies, H.L. Farmers' educational and coöperative union in Texas.--Leonard, W.E. Seasonal industries and their labor supplies in Texas.--Leftwich, S.M. The farm labor problem.--Griffin, M.H. A study in highway administration with special reference to Texas needs.--Vaughan, F.L. Railway rates and services as affecting the Texas farmer.--Randolph, Ralph. The theory and practice of speculation on produce exchanges.--Donaldson, W.T. Farm tenure in Texas.--Dailey, B.E. Our system of taxation and its effect on the farmer.--Index.
Resumo:
Bt transgenic cotton has not shown the same level of resistance to bollworm in China, as in other major Bt cotton growing areas of the world. The objective of this study was to investigate the effects of high temperature on the CryIA insecticidal protein content and nitrogen metabolism, in the leaf of Bt transgenic cotton. The study was undertaken on two transgenic cotton cultivars, one conventional (Xinyang 822) and the other a hybrid (Kumian No. 1), during the 2001 and 2002 growing seasons at the Yangzhou University Farm, Yangzhou, China. In the 2001 study, potted cotton plants were exposed to 37 C for 24 h under glasshouse conditions at three growth stages peak square, peak flowering and peak boll developing periods. Based on the 2001 results, in 2002 the same two cultivars were exposed to the same temperature for 48 h at two growth stages-peak flowering and boll developing periods. The results of the study indicated that the insecticidal protein content of the leaf was not significantly affected by the stress during the square and flowering periods. However, exposure to high temperature for 24h during the boll period reduced the CryIA protein content by approximately 51% in the cultivar Kumian No 1, and 30% in Xinyang 822 in the 2001 study, and by approximately 73 and 63% for 48 h with the same cultivars, respectively, in the 2002 study. Glutamic-pyruvic transaminase (GPT) activity, total free amino acid and soluble protein content, and the activity of protease in the leaf, showed relatively little change in response to high temperature in the flowering period. However, exposure to high temperature in the boll period resulted in the following changes - a reduction of GPT activity, a sharp increase in free amino acid content, a significant decrease in soluble protein content, and significant increases in the activity of protease. The results suggest that high temperature may result in the degradation of soluble protein in the leaf, with a resulting decline in the level of the toxin CryIA. It is believed that this may be the cause of the reduced efficacy of Bt cotton in growing conditions in China, where temperatures during the boll period often reach 36-40° C. © 2004 Elsevier B.V All rights reserved.
Resumo:
v. 13, n. 2, p. 82-92, 2016.
Resumo:
The CQ Cotton Regional Extension project has been a key to the delivery of emerging, cutting edge research information and knowledge to the Central Queensland cotton industry. The direct relevance of southern research to cotton production under the conditions experienced in CQ always has been an issue which could be addressed through regional assessment and adaptation. The project links the national research to the region through development and extension, with a strong focus on the major industry production issues including but not limited to disease, Integrated Pest Management (IPM), soils, nutrition and integrated weed management. Susan Mass has supported the implementation of national industry-wide programs particularly the industry Best Management Practices program (myBMP). This project has successfully transitioned to a focus on delivering national outcomes in target lead areas as part of National Development and Delivery Team established by Cotton CRC, CRDC and Cotton Australia, while maintaining a regional extension presence for Central Queensland cotton & grain farming systems. Susan Mass has very effectively merged and integrated strong regional extension support to cotton growers in Central Queensland with delivery of industry extension priorities across the entire industry in the Development and Delivery Team model. Susan is the target lead for disease and farm hygiene. Recognising the challenges of having regionally relevant research in Central Queensland, this project has facilitated locally based research including boll rot, Bt cotton resistance management, and mealybug biology through strong collaborations. This collaborative approach has included linkage to Department of Environment and Resource Managmeent (DERM) groups and myBMP programs resulting in a high uptake in CQ.