106 research outputs found

    Interferência Do Volume De Calda, Crescimento Dos Frutos E Precipitação Pluviométrica Sobre Os Depósitos Da Pulverização No Período De Controle Da Mancha Preta Dos Citros

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    Citrus black spot (CBS) caused by Guignardia citricarpa is one of the most serious Brazilian citrus diseases. This study aims to assess the interference of three application volumes in spray deposition citrus fruit, as well as fruit growth and rainfall effects on spray deposit reduction during the CBS control period. The experiment was carried out in a commercial citrus orchard, with sixteen-year-old trees of the Valencia variety, in Mogi Guaçu, São Paulo State, Brazil. The spray volumes were: 3.5 (1333L ha-1), 4.5 (1714L ha-1) and 8.5 (3238L ha-1) litres per tree, sprayed by an airblast sprayer using fungicides at recommended periods for disease control. The spray deposition quantification and residue was done by spectrophotometry using a copper oxychloride tracer. Samples were collected in three height zones of the tree (top, middle and bottom) and placed between trees on line plantation. Spray depositions were significantly smaller in the first application as a consequence of reduced fruit size. The spray losses on average for each day of rainfall ranged from 4.0 to 5.7%. There was no significant difference between application volumes regarding spray deposition on citrus fruit,which makes possible the reduction of application volumes, however, it is necessary to improve spraying techniques for the top zone of the citrus tree. © 2016, Universidade Federal de Santa Maria. All rights reserved.46582583

    The anisotropic Ashkin-Teller model: a renormalization group study

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    The two-dimensional ferromagnetic anisotropic Ashkin-Teller model is investigated through a real-space renormalization-group approach. The critical frontier, separating five distinct phases, recover all the known exacts results for the square lattice. The correlation length (νT)(\nu_T) and crossover (ϕ)(\phi) critical exponents are also calculated. With the only exception of the four-state Potts critical point, the entire phase diagram belongs to the Ising universality class.Comment: 3 ps figures, accepted for publication in Physica

    Singular open book structures from real mappings

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    We prove extensions of Milnor's theorem for germs with nonisolated singularity and use them to find new classes of genuine real analytic mappings ψ\psi with positive dimensional singular locus \Sing \psi \subset \psi^{-1}(0), for which the Milnor fibration exists and yields an open book structure with singular binding.Comment: more remark

    Synthesis, anti-toxoplasma gondii and antimicrobial activities of 2-hydrazolyl-3-phenyl-5-(4-nitrobenzylidene)-4-thiazolidinone substituted derivatives

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    A novel series of 2-hydrazolyl-3-phenyl-5-(4-nitrobenzylidene)-4-thiazolidinone substituted (3a-p) has been synthesized. The intermediates 2-hydrazolyl-3-phenyl-4-thiazolidinone substituted (2a-p) were prepared by condensation of benzaldehyde 4-phenyl-3-thiosemicarbazone substituted (1a-p) with ethyl chloroacetate. Theses intermediates were submitted to reaction with ethyl 2-cyano-3-(4-nitrophenyl)-acetate to give the title compounds. The 4-thiazolidinones were screened for their anti-Toxoplasma gondii, and all derivatives promoted decrease of percentage of infection of Vero cells, with elimination of intracellular tachyzoites. The LD50 ranged around 0.5 mM for the intracellular parasites and were higher than 10 mM for Vero cells. According to results of antimicrobial activity, only two compounds showed significant inhibition against M. luteus, but demonstrated higher values of MIC and MBC when compared with standard drug.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Synthesis, Cytotoxic and Antimicrobial activities of 5-benzylidene-2- [(pyridine-2-ylmethylene)hydrazono]-thiazolidin-4-one Derivatives

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    A novel series of 5-benzylidene-2-[(pyridine-2-ylmethylene)hydrazono]-thiazolidin-4-ones 3a-i has been synthesized. 2-[(Pyridine-2-ylmethylene)hydrazono]-thiazolidin-4-ones 2a-c were also obtained and used as intermediates to give the target compounds. The in vitro cytotoxic activity was evaluated for both series. The findings obtained showed that the compounds 2a, 2b, 3b and 3c were effective against the HEp-2 cell lines with IC50 in the 1.6 - 0.5 μg/mL range, whereas the compounds 2a (IC50 = 3.6 μg/mL), 2b (IC50 = 2.4 μg/mL) and 3f (IC50 = 3.5 μg/mL) showed good inhibitory effects against HT-29 cell lines. As complementary biological test, all 4-thiazolidinones were evaluated for antimicrobial activity against various bacterial and fungal species.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Synthesis, anti-toxoplasma gondii and antimicrobial activities of 2-hydrazolyl-3-phenyl-5-(4-nitrobenzylidene)-4-thiazolidinone substituted derivatives

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    A novel series of 2-hydrazolyl-3-phenyl-5-(4-nitrobenzylidene)-4-thiazolidinone substituted (3a-p) has been synthesized. The intermediates 2-hydrazolyl-3-phenyl-4-thiazolidinone substituted (2a-p) were prepared by condensation of benzaldehyde 4-phenyl-3-thiosemicarbazone substituted (1a-p) with ethyl chloroacetate. Theses intermediates were submitted to reaction with ethyl 2-cyano-3-(4-nitrophenyl)-acetate to give the title compounds. The 4-thiazolidinones were screened for their anti-Toxoplasma gondii, and all derivatives promoted decrease of percentage of infection of Vero cells, with elimination of intracellular tachyzoites. The LD50 ranged around 0.5 mM for the intracellular parasites and were higher than 10 mM for Vero cells. According to results of antimicrobial activity, only two compounds showed significant inhibition against M. luteus, but demonstrated higher values of MIC and MBC when compared with standard drug.Colegio de Farmacéuticos de la Provincia de Buenos Aire
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