328 research outputs found

    Removal of phosphate from phosphohistidine in proteins

    Get PDF
    AbstractKinetic constants of KM = 0.8 μM, 3 μM and 1.6 μM, and kcat = 9 s−1, 7 s−1 or 9 s−1 were determined for histidine dephosphorylation by protein phosphatases 1, 2A and 2C respectively. IC50 values were determined for the inhibition of protein phosphatase 1 by inhibitor 1 (IC50 = 1 nM), inhibitor-2 (IC50 = 3 nM) and okadaic acid (IC50 = 30 nM) and for the inhibition of protein phosphatase 2A by okadaic acid (IC50 = 0.02 nM) and microcystin-LR (IC50 = 1 nM). Inhibitor-1 (Ki = 0.7 nM) and okadaic acid (Ki = 32 nM) are noncompetitive with protein phosphatase 1. some of the IC50 values were low enough to violate the assumptions of the usual inhibition equations and a more general approach to the analysis of the data was used. On the basis of these kinetic parameters and the presence of phosphohistidine, the major cellular protein serine/threonine phosphatases are likely to act as protein histidine phosphatases in the cell

    Alfabetización ambiental : análisis del proceso de alfabetización ambiental y su relación con el desarrollo sustentable y propuesta de una herramienta que permita cuantificar el nivel de conocimiento suficiente para completar el proceso de alfabetización ambiental

    Get PDF
    In a holistic vision, our present global society, thanks to the fast speed of the spread of information permits a wider consciousness of the frequency and the scope of natural phenomena and economic disasters. This disasters are directly or indirectly man-made, and result often in the loss of human life and economic value. A bigger understanding of the scope and consequences is relevant. The present research work intention is to diagnose the level of environmental knowledge of a sample of the pre-university level students at the University of Buenos Aires in order to develop tools to bridge the gap between scientific knowledge and common thought/misconception. Through environmental education we will increase social and human capital and also enhance social sensitivity and commitment to a healthy natural environment, and facilitate . The text introduction is on material describing issues related to education, market failures, loss and/or lack of social values and the lack of opportunity in Argentine society. The work also contextualize the minimum of knowledge necessary to be considered knowledgeable about one¿s environment, both natural and man-made. The description of the estate of art, economy, environment, and social life, and the anthropological activities which have impact on the environment, facilitate a focus on the behavioral aspects of the study: ethical, moral, social dimensions and on the compatibility between Environmental Education and Sustainable Development. The impacts of the context are highlighted, it includes the difficulties the population faces at work, the socio-economic consequences of unemployment, and of the resulting poverty, the unequal distribution of wealth, and participation and involvement, or lack thereof, of individuals and communities in the taking of decisions that involve changes to the environment are all addressed. In paragraph nine, I will present the study and its conclusions. From the results we can infer that the average university-aged public shows very little knowledge of the problems facing our natural environment. This lack of knowledge means it is difficult for them to be involved with or make commitments to taking actions that will improve their environment. Also it is shown that without Environmental Education it will be impossible to make this vital sector of our population sensitive to the issues and to elicit public involvement in the search for solutions that will mitigate negative impacts on the environmentLa sociedad globalizada, disfruta de una gran velocidad de transmisión de datos, que dota de inmediatez a informaciones diversas sobre fenómenos naturales inclusive los de carácter catastrófico. Es conocido que el ser humano realiza intervenciones diferentes, directas o indirectas, y a pesar de que observamos con frecuencia elevadas pérdidas de vidas y económicas, suelen ser fenómenos insuficientemente comprendidos en su alcance y consecuencias. La presente investigación trata de estructurar conocimientos para mejorar la relación del ser humano con el ambiente. Se pretende concretar un diagnóstico del nivel de Alfabetización Ambiental de una muestra de la población pre universitaria de la Universidad de Buenos Aires y también, de lograr una herramienta que permita reducir la brecha entre el conocimiento científico y el saber popular, para generar un capital humano y social sensible y comprometido con la problemática ambiental y que posibilite el desarrollo de futuras investigaciones para que las personas actúen de manera responsable ante los fenómenos adversos. La tesis se ha desarrollado a partir de una descripción de la problemática educativa, los fallos de mercado y, las crisis de valores y falta de oportunidades, como contextualización para aproximar a la población los conocimientos mínimos necesarios para facilitar la salida del analfabetismo ambiental. Se expone el estado del arte socio ambiental y económico, describiendo las actividades antrópicas impactantes en el medio. Se concluye la parte expositiva focalizándose en lo conductual, tanto en lo ético como en la moral social y en la compatibilización entre la Educación Ambiental y el Desarrollo Sostenible. Se menciona la problemática de la Población y el trabajo, las consecuencias socio económicas del empleo y el desempleo, la pobreza y la inequidad de la distribución de la renta nacional, la participación social y el involucramiento individual y comunitario en la toma de decisiones relativas a los problemas ambientales. La parte experimental se despliega mediante la presentación del caso y sus conclusiones, con los resultados de la investigación: es posible inferir que los estudiantes promedio de la muestra poblacional de la universidad pública estudiada, disponen de poco conocimiento de la problemática ambiental lo cual no les facilita involucrarse ni comprometerse, pero queda demostrado que sin educación, sin Alfabetización Ambiental, es imposible conseguir su sensibilización a la problemática o el involucramiento social en la búsqueda de solucionar, mitigar o reducir los impactos adverso

    Senate called to order at 11:10 a.m. President pro Tempore Amodei presiding.

    Get PDF
    Lord, You have given us eyes to see and ears to hear. But, in our task of crafting legislation, often those gifts by themselves are not enough. Grant us vision and understanding as we seek how to best govern Your people. AMEN. Pledge of allegiance to the Flag. Senator Raggio moved that further reading of the Journal be dispensed with, and the President pro Tempore and Secretary be authorized to make the necessary corrections and additions. Motion carried. REPORTS OF COMMITTEE

    Climacteric fruit ripening: Ethylene-dependent and independent regulation of ripening pathways in melon fruit

    Get PDF
    Cantaloupe melons have a typical climacteric behaviour with ethylene playing a major role in the regulation of the ripening process and affecting the ripening rate. Crossing of Cantaloupe Charentais melon with a non-climacteric melon indicated that the climacteric character is genetically dominant and conferred by two duplicated loci only. However, other experiments made by crossing two non-climacteric melons have generated climacteric fruit, indicating that different and complex genetic regulation exists for the climacteric character. Suppression of ethylene production by antisense ACC oxidase RNA in Charentais melon has shown that, while many ripening pathways were regulated by ethylene (synthesis of aroma volatiles, respiratory climacteric and degreening of the rind), some were ethylene-independent (initiation of climacteric, sugar accumulation, loss of acidity and coloration of the pulp). Softening of the flesh comprised both ethylene-dependent and independent components that were correlated with differential regulation of cell wall degrading genes. These results indicate that climacteric (ethylene-dependent) and non-climacteric (ethylene-independent) regulation coexist during climacteric fruit ripening. In addition, ethylenesuppressed melons allowed demonstrating that the various ethylene-dependent events exhibited differential sensitivity to ethylene and that ethylene was promoting sensitivity to chilling injury. Throughout this review, the data generated with melon are compared with those obtained with tomato and other fruit

    Modified atmosphere packaging confers additional chilling tolerance on ethylene-inhibited cantaloupe Charentais melon fruit

    Get PDF
    Cantaloupe Charentais melon fruits are subject to chilling injury when stored at low temperatures, around 2 °C. Ethylene-suppressed cantaloupe Charentais melon, expressing a 1-aminocyclopropane-1-carboxylic acid (ACC)-oxidase gene in antisense orientation, showed strong, but not total, resistance to chilling injury, allowing an extended storage at low temperatures. Modified atmosphere packaging (MAP) is known to alleviate chilling injury symptoms in a variety of chilling-sensitive horticultural commodities. In the present work, we have compared the effects of MAP in non-retractile plastic film and storage in air on ethylene production, respiratory activity, development of chilling injury symptoms, water loss, ion leakage and accumulation of ethanol and acetaldehyde in wild-type and ethylene-suppressed melons, during storage at 2 °C and after re-warming at 22 °C. MAP reduced chilling injury and extended the postharvest life of wild-type fruit and conferred additional chilling resistance on ethylene-suppressed melons. Reduction of ethylene production and water loss are necessary to prevent chilling injury symptoms in melon

    Fruit flies : disinfestation, techniques used, possible application to mango

    Full text link
    Introduction. The methods of fruit disinfestation against fruit flies use processes (physical methods) which differ according to the export country and fruit which must be disinfested. The term definitions are made clear and the various treatments are presented. Heat treatments. For mango, treatments usable for disinfestation can only utilize heat, because of the strong sensitivity of this fruit to cold temperatures. The heat treatments in general consist of using an immersion in hot water by a system of batches or an uninterrupted bath. These treatments are then followed or not by a fruit fast cooling which can be carried out by ventilation (cold air) or hydrocooling (water). Heat can also be obtained by use of forced hot air or hot vapor, because a higher temperature than 45 °C kills fly eggs and larvae. Microwave treatments. The use of microwaves is also a technique which makes it possible to increase the temperature in the fruit heart. Irradiation. The last possible solution is the use of irradiation, which uses a principle different from the preceding treatments. Conclusion. In comparison with the most current treatments (vapor heat treatment and forced hot-air treatment), the hot water treatment has many advantages: it is easy to implement, it is quick, it kills surface parasitic organisms, it makes it possible to clean the fruit surface and its cost only corresponds to approximately 10%of the cost of one vapor heat treatment. It would thus be recommended for mango disinfestation

    Maintaining postharvest quality of cold stored ‘Hass’ avocados by altering the fatty acids content and composition with the use of natural volatile compounds – methyl jasmonate and methyl salicylate

    Get PDF
    BACKGROUND: Low temperature is often used to reduce metabolic processes and extend the storage of fruit, however, in the case of avocado the temperature below 3 °C would often result in development of physiological disorders associated with chilling injury. The objective of this study was to investigate the ability of methyl jasmonate (MeJA) and methyl salicylate (MeSA) vapours to alleviate the chilling injury in ‘Hass’ avocado fruit kept at 2 °C for 21 d followed by 6-7 d shelf-life at 20 °C, simulating supply chain conditions. RESULTS: The incidence and severity of chilling injury was significantly reduced in MeJA and MeSA exposed fruit, especially at 100 µmol l-1. The mechanism involved improved membrane integrity via alteration of the fatty acids content and composition, down-regulation of LOX gene expression and reduced activity of lipoxygenase. CONCLUSION: Methyl jasmonate and methyl salicylate have the potential for being used with ‘Hass’ avocado fruit shipped at low temperature by reducing their susceptibility to chilling injury
    corecore