768 research outputs found

    Studies on the Effect of Temperature on the Development of Soft Rot of Cabbage (Brassica oleracea var. Capitata) Caused by Erwinia carotovora sub Sp. Carotovora

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    Soft rot is one of the destructive diseases of vegetables including cabbage worldwide. Since the temperature is one of the important factors for destructive nature of disease during storage and transportation, experiments were conducted to standardize optimum temperature for the growth of pathogen which revealed pathogen could grow at all the temperatures from 15 to 40°C. Marked higher growth was recorded at 30°C and considerable growth was at 25 and 35°C. During the study of effect of temperature on soft rot disease after 4 and 6 days of storage at different temperatures it was concluded that 30-35°C mostly favor the soft rot in cabbage and thus emphasis is to be given to prevent the disease during the prevailing temperatures in the region, in order to prevent losses due to the disease in cabbage and other hosts of the same pathogen

    Mechanism of Fluoride Uptake by Hydroxyapatite from Acidic Fluoride Solutions: I. Theoretical Considerations

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    A mathematical model for the mechanism of calcium fluoride formation on hydroxyapatite in buffered fluoride solutions is proposed. It takes into account the physical and chemical processes that occur during the reaction. With the model it is possible to evaluate a priori the fluoride uptake potential of fluoride solutions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67263/2/10.1177_00220345700490066601.pd

    Effect of Silver Ions on Ethylene Metabolism of Mustard Grown Under Irrigated and Non- irrigated Conditions

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    A field experiment was conducted during the winter season of 2004-2005 at the Experimental farm of Aligarh Muslim University, Aligarh, India on mustard (Brassica juncea L. Czen and Coss, cultivar Alankar) under irrigated and non -irrigated  conditions to evaluate the application of 0  and 200 µl/L  ethrel (E200) or 1 mM silver thiosulphate (S) at flowering stage along with a basal  uniform application of 80 kg N ha-1 on leaf area, plant dry mass, net photosynthetic rate and seed yield. Silver thoisulphate, which inhibits the physiological action of ethylene was used in the experiment with ethrel. Ethrel is a source of ethylene and its effects are manifested through physiological action of ethylene. Ethrel 200 µl/L (E200) treatment enhanced leaf area, net photosynthetic rate, plant dry mass and seed yield by 10.6, 9.1, 7.7 and 11.6% over S treatment. So silver thiosulphate (S) reduces the physiological action of ethrel (source of ethylene) in this study. This clearly indicates that silver ions used in this experiment in the form of silver thiosulphate inhibits the action of ethylene metabolism in mustard

    Biopesticides: Ecofriendly and biorational alternatives to vegetable production and environmental sustainability

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    Insect pests, nematodes and plant diseases of vegetables are generally controlled by frequent applications of chemical pesticides with an objective to increase crop productivity and obtain greater profit in conventional farming. With consumers' awareness and perception, vegetables without residue of chemicals are being preferred in local and export markets. For this purpose, plant-derived crude products or formulated pesticides can be eco-friendly, effective and economical for an average producer. Several pressures have accelerated the search for more environmentally and toxicologically safe and more selective and efficacious pesticides. Biopesticides, including microbial pesticides, entomopathogenic nematodes, baculoviruses, plant derived pesticides, and insect pheromones are receiving increased exposure in scientific annals as alternatives to chemical pesticides and also as key components of integrated pest management (IPM) systems. The reality, however, is that biopesticides currently represent only a small fraction (1.3%) of the world pesticide market. However, the growth rate for biopesticides over the next 10 years has been forecast at 10–l5% per annum in contrast to 2% for chemical pesticides. It is imperative to make aware the farming community regarding the use of biopesticides to reduce the environmental pollution

    Acid-induced aggregation and gelation of heat-treated chia proteins

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    This work studied for the first time the acid-induced aggregation and gelation of heat-treated chia protein isolates obtained by extraction at pH 10 or 12 (CPI10 and CPI12, respectively). The aggregation state of proteins was modified during acidification. The size of the aggregates was reduced for both samples when the pH decreased but below pH 4.5 further protein aggregation took place for CPI12. Gelation of CPI12 was completed after about 30 min of acidification with glucone-δ-lactone. By contrast, this period was not enough to reach a constant value in G′ for CPI10. When gelation was ensured, confocal laser scanning micrographs from those gels revealed a coarse and irregular structure with large pores (median size of diameters: 30 μm). Instead, micrographs from CPI12 cold gels showed a more regular and interconnected network, with smaller pores (median size of diameters: 9 μm). These differences are consistent with a higher elastic behaviour ((Formula presented.) = 13.6 ± 0.1 Pa).Fil: López, Débora Natalia. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química y Física. Área Fisicoquímica; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Química e Ingeniería-Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Ingrassia, Romina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química y Física. Área Fisicoquímica; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Busti, Pablo Andres. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química y Física. Área Fisicoquímica; ArgentinaFil: Wagner, Jorge Ricardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Boeris, Valeria. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química y Física. Área Fisicoquímica; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Química e Ingeniería-Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Spelzini, Darío. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química y Física. Área Fisicoquímica; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Química e Ingeniería-Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentin

    Effect of ethrel and nitrogen on nitrate reductase activity, photosynthesis, biomass and yield of mustard (Brassica juncea L. Czern and Coss)

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          The plants of mustard (Brassica juncea L. Czern and Coss; cultivar Alankar) were treated with 200 µL/L ethrel (2-chloro ethyl phosphonic acid) at flowering stage (60 d after sowing) along with basal application of nitrogen 40, 60, and 80 kg N ha-1. Effect of ethrel and nitrogen on leaf area index (LAI), net photosynthetic rate (PN), nitrate reductase (NR) activity and plant dry mass were recorded at 80 and 100 d after sowing. At harvest pods plant-1, 1000 seed mass and seed yield were recorded. Ethrel 200 µL/L x 80 kg N ha-1 treatment enhanced all the characteristics studied during the experiment

    Physical Model for Plaque Action in the Tooth-Plaque-Saliva System

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    A physical model describing the interrelationships of demineralization, remineralization, plaque thickness, glucose levels, and plaque enzymatic activity was presented. Selection of constants and variations of the parameters were kept in the range of possible in vivo situations. The results of calculations were discussed and correlated with the results of in vivo studies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66483/2/10.1177_00220345700490013001.pd

    Complete sequence-based pathway analysis by differential on-chip DNA and RNA extraction from a single cell

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    Abstract We demonstrate on-chip, differential DNA and RNA extraction from a single cell using a microfluidic chip and a two-stage lysis protocol. This method enables direct use of the whole extract, without additional washing steps, reducing sample loss. Using this method, the tumor driving pathway in individual cells from a colorectal cancer cell line was determined by applying a Bayesian computational pathway model to sequences obtained from the RNA fraction of a single cell and, the mutations driving the pathway were determined by analyzing sequences obtained from the DNA fraction of the same single cell. This combined functional and mutational pathway assessment of a single cell could be of significant value for dissecting cellular heterogeneity in tumors and analyzing single circulating tumor cells

    Functional characterization of a melon alcohol acyl-transferase gene family involved in the biosynthesis of ester volatiles. Identification of the crucial role of a threonine residue for enzyme activity

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    Volatile esters, a major class of compounds contributing to the aroma of many fruit, are synthesized by alcohol acyl-transferases (AAT). We demonstrate here that, in Charentais melon (Cucumis melo var. cantalupensis), AAT are encoded by a gene family of at least four members with amino acid identity ranging from 84% (Cm-AAT1/Cm-AAT2) and 58% (Cm-AAT1/Cm-AAT3) to only 22% (Cm-AAT1/Cm-AAT4). All encoded proteins, except Cm-AAT2, were enzymatically active upon expression in yeast and show differential substrate preferences. Cm-AAT1 protein produces a wide range of short and long-chain acyl esters but has strong preference for the formation of E-2-hexenyl acetate and hexyl hexanoate. Cm-AAT3 also accepts a wide range of substrates but with very strong preference for producing benzyl acetate. Cm-AAT4 is almost exclusively devoted to the formation of acetates, with strong preference for cinnamoyl acetate. Site directed mutagenesis demonstrated that the failure of Cm-AAT2 to produce volatile esters is related to the presence of a 268-alanine residue instead of threonine as in all active AAT proteins. Mutating 268-A into 268-T of Cm-AAT2 restored enzyme activity, while mutating 268-T into 268-A abolished activity of Cm-AAT1. Activities of all three proteins measured with the prefered substrates sharply increase during fruit ripening. The expression of all Cm-AAT genes is up-regulated during ripening and inhibited in antisense ACC oxidase melons and in fruit treated with the ethylene antagonist 1-methylcyclopropene (1-MCP), indicating a positive regulation by ethylene. The data presented in this work suggest that the multiplicity of AAT genes accounts for the great diversity of esters formed in melon

    Efeito do tratamento com aminoetoxivinilglicina (AVG) na queda pré-colheita e na maturação dos frutos em macieiras

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    ABSTRACTApple trees cultivars Gala and Fuji were sprayed four weeks before commercial harvest with aminoethoxyvinilglycine (AVG), at doses of 0, 125, or 250 mg L-1, and assessed for preharvest fruit drop, fruit growth, and maturation on tree. In 'Gala', 64 days after AVG spraying, fruit drop for control treatment was 85%, and AVG (at 125 and 250 mg L-1) reduced it to 10%. In 'Fuji', 64 days after AVG spraying, fruit drop for control was 6%, while treatments with AVG (at 125 and 250 mg L-1) increased fruit drop to 10%. AVG was a powerful retardant of fruit maturation for 'Gala' but not for 'Fuji'. In 'Gala', the most affected attribute was the skin background color, followed, in decreasing order, by soluble solids content, the starch index, skin red color, the flesh firmness, and titratable acidity. In 'Gala', only flesh firmness retention was improved by increasing AVG dose from 125 mg L-1 to 250 mg L-1. The AVG at 250 mg L-1 inhibited "Gala" late fruit growth but not 'Fuji'. __________________________________________________________________________________ RESUMOMacieiras, das cultivares Gala e Fuji, foram pulverizadas quatro semanas antes do início da colheita comercial dos frutos com aminoetoxivinilglicina (AVG), nas concentrações de 0; 125 ou 250 mg L-1, e avaliadas quanto à queda de frutos na pré-colheita, o crescimento e maturação dos frutos. Na cultivar Gala, 64 dias após a pulverização com AVG, a queda pré-colheita no tratamento-controle era de 85%, mas os tratamentos com AVG (125 e 250 mg L-1) reduziram esta queda para 10%. Na cultivar Fuji, 64 dias após a pulverização com AVG, a queda de frutos no tratamento-controle era de 6%, e os tratamentos com AVG (125 e 250 mg L-1) aumentaram esta queda para 10%. Tratamentos com AVG retardaram substancialmente a maturação dos frutos da cultivar Gala, mas não da 'Fuji'. Na cultivar Gala, o atributo mais afetado foi a cor de fundo da casca, seguido, em ordem decrescente, pelo conteúdo de sólidos solúveis totais, índice de iodo-amido, cor vermelha da casca, firmeza de polpa e acidez titulável. Na cultivar Gala, apenas a retenção de firmeza de polpa foi significativamente aumentada com o aumento na concentração de AVG de 125 mg L-1 para 250 mg L-1. A concentração de 250 mg L-1 inibiu o crescimento final de frutos na cultivar Gala, mas não na 'Fuji'
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