Ministry of Agriculture

About: Ministry of Agriculture is a government organization based out in Rio de Janeiro, Brazil. It is known for research contribution in the topics: Biology & Chemistry. The organization has 1153 authors who have published 1189 publications receiving 14442 citations.

Validação interlaboratorial do teste de polarização fluorescente para o diagnóstico sorológico da brucelose bovina

Abstract: Esta investigacao teve por objetivo validar o teste de polarizacao fluorescente (TPF) para o diagnostico sorologico da brucelose bovina, determinando a sensibilidade (SE) e a especificidade relativas (SP) e verificando a reprodutibilidade do teste em quatro laboratorios no Brasil. Foram selecionadas 1.389 amostras de soro sanguineo, as quais foram inicialmente submetidas aos testes do antigeno acidificado tamponado (AAT) e mercaptoetanol (2-ME). As mesmas amostras foram submetidas a reacao de fixacao de complemento (RFC) e ao TPF. Para a avaliacao do TPF, foi adotada a combinacao dos resultados do AAT, da RFC e do 2-ME, utilizados como populacao de referencia (padrao-ouro). Para a determinacao do ponto de corte do TPF que proporciona a melhor combinacao de sensibilidade e especificidade, foi usada a analise TG-ROC. A concordância entre os resultados dos quatro laboratorios foi determinada com base no indicador kappa e no coeficiente de correlacao de Pearson. Os pontos de corte do TPF situaram-se entre 85,2 e 93,6 mP, conforme o laboratorio. A sensibilidade variou de 91,7 a 97,3%, e a especificidade situou-se na faixa de 82,6 a 98,3%. Na comparacao entre os resultados do TPF dos quatro laboratorios, o indicador kappa ficou entre 0,69 e 0,95, o que indica, na maioria das situacoes, reprodutibilidade excelente, e o coeficiente de correlacao variou entre 0,76 e 0,99. Os resultados indicaram que o TPF apresentou bom desempenho, na maioria das situacoes, com sensibilidade e especificidade elevadas. Em comparacao com os testes convencionais, o TPF apresenta as vantagens de ser de execucao mais rapida e mais facil e nao estar sujeito a ocorrencia de prozona, como a RFC e o 2-ME, nem de atividade anticomplementar, como a RFC.

Evaluation of Mycosphaerella impact on eucalypts plantations in Portugal.

Abstract: Mycosphaerella leaf disease (MLD) is one of the most important diseases of eucalypts plantations worldwide. However, only recently it has become relevant in Portugal. Caused by a complex of Mycosphaerella species, this disease reduces the photosynthetic area and can cause tree defoliation. In extreme cases it causes reduction in the volume of wood produced. In order to relate the observed symptoms of MLD with the presence of the pathogen and at the same time obtaining an evaluation of eucalypt clones and family susceptibility, two experimental plantations were established in places where the disease has been detected. Data on the percentage of affected crown (necrosis or defoliation) were collected and some of the Mycosphaerella species present were identified (M. africana, M. communis, M. grandis, M. lateralis, M. marksii, M. nubilosa, M. parva, M. vespa and M. walkeri).

Uso do 1-metilciclopropeno no controle da maturação de maçãs cv. 'Royal Gala'

Abstract: - In the present work were evaluated the effects of 1-MCP on ‘Royal Gala’ apples ripening. The apples were harvested at two ripen essstages: Ripeness stage at harvest one apples were with 82, 4 N flesh firmness, 0,36 % malic acid and 14,10 oBrix. Ethylene prod ution of these appleswas about 2,0 nL.g -1 .h . Apples of ripeness stage 2 produced about 17,0 nL.g -1 .h -1 ethylene and had flesh firmness values 79,96 N, 0,33 % malic acidand 13,74 oBrix. The apples were treated with 1-methylcyclopropene (1-MCP) using three concentrations and one control, 0, 325, 625 and 1250 nL.L -1 which were applied during 48 hours at temperature of 20 ± 2 oC. After this time the fruits were stored during 60 days at the s ame temperature. Fleshfirmness, titratable acidity, soluble solids and ethylene production were evaluated at every 10 days. All concentrations of the 1-MCP product havereduced the fruit’s ethylene production and delayed the occurrence of the climacteric peak independently of the ripening stage. The treatments with1-MCP also gave the bigger values of pulp firmness and titratable acidity.

Determination of steroids in bovine hair: Validation of a microwave-assisted chemical derivatization method using liquid chromatography-tandem mass spectrometry and in vivo studies.

Abstract: Hair analysis has attracted great attention in the regulatory analysis of food-producing animals, particularly due to the wider detection window of veterinary drugs in this matrix and also the possibility of confirming parent drugs with minimum metabolization. This work involved the development and validation of a quantitative liquid chromatography-tandem mass spectrometry method to determine 25 steroids and steroid esters in bovine hair. Sensitivity was improved using a fast and effective microwave-assisted chemical derivatization with methoxyamine hydrochloride. The validation was conducted in accordance with the Decision 657/2002/EC guidelines. An animal experimentation procedure was performed on 12 bovine animals in which two commercial formulations containing boldenone undecylenate and testosterone propionate were administrated via intramuscular injections on the neck. The samples were collected for 78 days in which the detection of the administrated analytes was only observed near the application sites. For some of the monitored days, no analyte was detected on the neck area. Since the migration of the analytes was not observed in areas other than the application site, false-negative results should be carefully considered when monitoring animal hair samples.