220 research outputs found

    Comparison of asian soybean rust chemical control on a susceptible and a resistant cultivar in Brazil.

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    The development of resistant cultivars to the Asian soybean rust (ASR), caused by Phakopsora pachyrhizi, brought an additional tool to the disease management in Brazil. ASR develops slower in resistant cultivars than in susceptible ones, allowing a reduction of the number of fungicide sprays, but chemical control is still necessary. A field trial was conducted in Ponta Grossa, Parana State, in order to compare the effects of ASR chemical control with four fungicide formulations, in both resistant (BRSGO 7560) and susceptible (CD 249 RR) soybean cultivars. The fungicides were applied twice, beginning at soybean growth stage R3?R4, when first uredinia were observed, and at soybean stage R5.3?R5.4. The fungicides used were premix formulations of pyraclostrobin + epoxiconazole + fluxapyroxad (40+64.8+40 g a.i./ha), azoxystrobin + cyproconazole (60+24 g a.i./ha), pyraclostrobin + epoxiconazole (79.8+30 g a.i./ha), and epoxiconazole (125 g a.i./ha). The ASR severity at soybean growth stage R7 on nonsprayed plots reached 75.4% on the resistant cultivar and 98.6% on the susceptible cultivar. Lower ASR severity index were observed in the resistant cultivar, with the treatments pyraclostrobin + epoxiconazole (9.8%), pyraclostrobin + epoxiconazole + fluxapyroxad (10.5%), and azoxystrobin + cyproconazole (10.9%), with an average of disease control ranging from 90.8 to 91.3%. The treatments with pyraclostrobin + epoxiconazole and pyraclostrobin + epoxiconazole + fluxapyroxad provided the lower yield reductions on both soybean cultivars. The yield and grain weight reductions in the nonsprayed treatment were 32 and 28%, respectively, on the resistant cultivar and 44 and 32%, respectively, on the susceptible cultivar

    Applications of IGY antibodies to influenza a virus detection in infected cells by immunocytochemistry.

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    Introduction and objectives: Influenza is a disease caused by infection of the host respiratory tract by influenza type A virus that affects a wide variety of species, including human, swine, equine, poultry and sea mammals. The viral RNA is encapsidated by the nucleoprotein (NP), which is a highly conserved protein among influenza A viruses. Detection of influenza virus can be accomplished by assessing specific immune response to the virus, by direct detection of viral RNA or virus antigen in infected tissues. Some diagnostic tests use antibodies produced in mammals to influenza virus detection. However, due to high cost and concerns related to animal welfare, alternative production of antibodies in mammals has been described. The immunoglobulin Y (IgY) is a class of antibodies in poultry that is transferred to the egg yolk. These antibodies are easy to obtain from eggs and their use has been described for immunotherapy, immunodiagnosis and research. The objective of this study was to produce IgY antibodies anti-NP in laying hens immunized with influenza A virus NP, and to evaluate the purified IgY antibodies in influenza virus detection

    21 de setiembre: día de la ciencia y la técnica

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    Con motivo del 3O aniversario de la instauración del 21 de setiembre como día de la Ciencia y la Técnica en la Provincia de Buenos Aires, la CIC le ha solicitado a un grupo selecto de científicos, su opinión sobre aspectos esenciales del quehacer científico y tecnológico. El presente texto contiene los siguientes trabajos: - Consideraciones acerca de la investigacion técnico-científica sobre materiales, por Eduardo R. Abril. - Ciencia y tecnología de alimentos, por Pedro Cattáneo - Ciencia y tecnología en química orgánica por Venancio Deulofeu. - Ciencia y tecnología - recursos humanos por Ernesto E. Galloni. - Discurso de apertura de la reunion sobre ciencia y tecnologia realizada en Mar del Plata del 6 al 8 de julio de 1978 por Luis F. Leloir. - Incidencia de la investigación en el desarrollo de la metalurgia por Roberto F. Recoder. - Importancia de la investigación matemática en la sociedad contemporánea por Luis A. Santaló. - La investigación en fisicoquímica y su proyección en el desarrollo científico y tecnológico por Hans J. Schumacher

    ESR, raman and conductivity studies on fractionated poly(2-methoxyaniline-5-sulfonic acid)

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    Synthesis methods used to produce poly(2-methoxyaniline-5-sulfonic acid) (PMAS), a water soluble, self-doped conducting polymer, have been shown to form two distinctly different polymer fractions with molecular weights of approximately 2 kDa and 8 -10 kDa. The low molecular weight (LMWT) PMAS fraction is redox inactive and non-conducting while the high molecular weight (HMWT) PMAS is electro-active with electrical conductivities of 0.94 0.05 S cm-1. Previous investigations have illustrated the different photochemical and electrochemical properties of these fractions, but have not correlated these properties with the structural and electronic interactions that drive them. Incomplete purification of the PMAS mixture, typically via bag dialysis, has been shown to result in a mixture of approximately 50:50 HMWT:LMWT PMAS with electrical conductivity significantly lower at approximately 0.10 to 0.26 S cm-1. The difference between the electrical conductivities of these fractions has been investigated by the controlled addition of the non-conducting LMWT PMAS fraction into the HMWT PMAS composite film with the subsequent electronic properties investigated by solid-state ESR and Raman spectroscopies. These studies illustrate strong electronic intereactions of the insulating LMWT PMAS with the emeraldine salt HMWT PMAS to substantially alter the population of the electronic charge carriers in the conducting polymer. ESR studies on these mixtures, when compared to HMWT PMAS, exhibited a lower level of electron spin in the presence of LMWT PMAS indicative of the the formation of low spin bipolarons without a change the oxidation state of the conducting HMWT fraction

    Innate immunity in chicken lines developed by Embrapa Suínos e Aves: antimicrobial activity of macrophages and serum.

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    Abstract: The objective of this study was to compare the antimicrobial activity of macrophages and serum in laying hen (MM, CC, and CCc) and broiler chicken lineages (TT and LL). Macrophages were evaluated for phagocytic and antimicrobial activity. Microbicidal serum activity was evaluated by the resistance test for serum and the agar test. The results showed that phagocytic activity was higher in males of the MM strain, with 13% of macrophages presenting phagocytosis, while the other lineages studied, and even female MM, presented a rate of 6% of phagocytic cells. However, antimicrobial activity in macrophages from males of CCc lineage and females of TT lineage were higher, eliminating more than 30% of the Salmonella enterica inoculum, while in the other strains, the results were similar, with inoculum reduction below 30%. In the serum resistance assay, female laying lines presented higher antibacterial activity than female broiler lines. In the trials to evaluate the microbicide activity of the serum, females of both broiler and laying lineages presented higher performance when compared with males of the same lineage. Females of laying hen lines (MM and CC) present a greater antibacterium activity than males. These results can contribute to a better understanding of the immune response in broiler chicken and laying hen lineages, to aid development of lineages of birds more resistant to pathogen

    METHYLPHENIDATE: PROCONVULSANT EFFECT AND ACTION ON ACETYL CHOLINESTERASE ACTIVITY IN YOUNG AND ADULT MICE

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    Objective: Methylphenidate (MPH) is a derivative of piperidine, structurally related to amphetamine. It is the most widely psychostimulant used in Brazil for treating attention deficit disorder and hyperactivity. This drug was investigated in an epilepsy model induced by pilocarpine and on acetylcholinesterase (AChE) activity in young and adult mice. Methods: The control group was treated with saline. The treated groups received MPH (2.5, 5, 10 or 20 mg/kg) in single dose, followed by pilocarpine (400mg/Kg). The groups were observed for1h after treatment. Results: MPH, in all doses, was efficacious in decreasing both the latency to first seizures and the survival percentage in young and adult animals. Determination of AChE activity in the hippocampus and striatum of young and adult animals, after pilocarpine-induced status epilepticus, demonstrated that pretreatment with MPH reduced AChE activity only in the striatum. Conclusion: Our findings suggest that MPH has proconvulsant action and cholinergic neurotransmission system can play a role in this effect
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