4,773 research outputs found

    Toxic effects of Ricinus communis non-protein trypsin inhibitor on Spodoptera frugiperda (J. E. Smith) (Lepidoptera:Noctuidae)

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    In the study reported herein, we aimed to isolate a trypsin inhibitor from Ricinus communis leaves through chromatographic and spectrometric techniques and evaluate its toxic effects on the development of Spodoptera frugiperda larvae. Plant extracts were submitted to fractionation in adsorption column. The fraction 10, which showed the highest inhibitory activity, were incorporated into an artificial diet at the concentrations of 0, 0.06, 0.12, 0.25 and 0.5%, and offered to S. frugiperda larvae. Fresh weight of larvae, food consumed and weight of eliminated faeces were registered. Based on these parameters the following nutritional index were calculated: Relative Consumption Rate (RCR), Relative Metabolic Rate (RMR), Relative Growth Rate (RGR), Approximated Digestibility (AD), Efficiency of Ingested Food Conversion (EIC), Efficiency of Digested Food Conversion (EDC) and the Metabolic Cost (100 - EDC). The inhibitor at 0.5% concentration was deleterious to S. frugiperda, extending the larval stage in 11 days, with higher RCR and ECD, and lower RGR, ECI and ECD. Therefore, the trypsin inhibitor from leaves of R. communis affected the S. frugiperda larval development, being promising in studies of alternative and sustainable control methods for lepidopteran pest species.Keywords: Castor beans, enzymatic inhibition, integrated pest management, plant defense against herbivor

    Instalações zootécnicas visando a produção de silagem.

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    Editado por Almir Vieira Silva e José de Brito Lourenço Júnior

    Pollen spectrum of honey of Apis mellifera L. and stingless bees (Hymenoptera: Apidae) from the semi-arid region of Bahia State, Brazil

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    Pollen in honey reflects its botanical origin and melissopalynology is used to identify origin, type, and quantities of pollen grains of the botanical species visited by bees. This study aimed to identify the pollen spectrum of honeys from Apis mellifera and stingless bees produced in the semi-arid region of Bahia, Brazil. We analysed 78 honey samples, which were submitted to the acetolysis process for identification and quantification of pollen types. Fabaceae, Asteraceae and Euphorbiaceae were the most predominant families in pollen types. For Fabaceae, the most representative pollen types were Chamaecrista 1, Mimosa caesalpiniifolia, Mimosa pudica, Mimosa tenuiflora, Prosopis and Senna. The results indicate that the flora explored by the bees to collect nectar is diverse in the semi-arid region of Bahia and the honeys analysed were classified as multifloral.info:eu-repo/semantics/publishedVersio

    Avaliação de cultivares de mandioca em ambientes de Tabuleiros e Agreste inseridos nos Estados da Bahia e Sergipe: safra 2010/2011.

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    O objetivo deste trabalho foi averiguar o desempenho de vinte e nove cultivares de mandioca, quanto às variáveis altura da planta, rendimentos da parte aérea, de raízes tuberosas e de amido e teores de matéria seca e de amido nos municípios de Cruz das Almas/BA e Umbaúba/SE, inseridos em áreas de Tabuleiros Costeiros desses estados e, São Domingos/SE, localizado no Agreste sergipano, para fins de recomendação. Foram plantados dois ensaios na safra 2010-2011, utilizando-se o delineamento experimental em blocos ao acaso com três repetições dos 29 tratamentos. Esses ensaios foram colhidos aos 12 e 15 meses após o plantio. Detectaram-se, nas análises de variância conjuntas, diferenças entre as cultivares e os ambientes e inconsistência no comportamento das cultivares perante as condições ambientais, para todas variáveis estudadas. As cultivares de mandioca BRS Caipira, Irará, Clone 9783/13, BRS Tapioqueira, Preta do Sul, Poti Branca, Mucuri, Sergipe e Lagoão apresentaram bom desempenho agronômico, justificando suas recomendações para exploração comercial visando a produção de amido em áreas dos Tabuleiros Costeiros e Agreste dos Estados da Bahia e Sergipe, por associarem produtividades elevadas de raízes tuberosas a elevados rendimentos de amido, permitindo a maximização do produto final por unidade de área cultivadabitstream/item/118386/1/Avaliacao-de-cultivares-de-mandioca-BP-85.pd

    Desempenho de cultivares de mandioca no Nordeste brasileiro na safra 2009/2010.

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    O objetivo deste trabalho foi averiguar o comportamento de cultivares de mandioca em diferentes épocas de colheita e ambientes de produção visando atender as necessidades dos produtores de mandioca do Nordeste brasileiro., Os ensaios foram realizados no ano agrícola de 2009/2010, nos estados da Bahia, Sergipe, Pernambuco e Rio Grande do Norte. O delineamento experimental adotado nos experimentos foi o de blocos ao acaso, com três repetições, nos quais 16 cultivares de mandioca foram avaliadas. Os resultados permitem inferir que as cultivares BRS Caipira, BRS Tapioqueira, BRS Poti Branca, Irará, Kiriris e o Clone 9783/13 consubstanciam-se em alternativas promissoras para a mandiocultura regional, por apresentarem altas produtividades tanto de raízes tuberosas, quanto de amido e biomassa da parte aérea.bitstream/item/118385/1/Desempenho-de-Cultivares-BP-84.pd

    Constituents and antiproliferative activity of extracts from leaves of Croton macrobothrys

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    Croton macrobothrys Baill, Euphorbiaceae, is a tree from the Atlantic Forest in Southern Brazil, used in traditional medicine and popularly known as "dragon's blood" and "pau-sangue". Leaf n-hexane, dichloromethane and methanol extracts were analyzed by GC/MS and evaluated for their in vitro antiproliferative activity on cell lines 786-0 (kidney), HT-29 (colon), K562 (leukemia), NCI-ADR/RES (drug resistant ovary), NCI-H460 (lung), MCF-7 (mammary), PC-3 (prostate), OVCAR-3 (ovary), U251 (glioma) and UACC-62 (melanoma). The dicloromethane extract exhibited activity against all cell lines at the concentration 25 µg/mL, in particular on cell lines NCI-H460 (GI50 0.33 μg/mL) and K5662 (GI50 0.91 μg/mL). Relevant constituents in dichloromethane extract are the alkaloids corydine and salutaridine, as well as the diterpenes geranylgeraniol and crotonin-derived clerodanes

    Modulatory effects of cAMP and PKC activation on gap junctional intercellular communication among thymic epithelial cells

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    <p>Abstract</p> <p>Background</p> <p>We investigated the effects of the signaling molecules, cyclic AMP (cAMP) and protein-kinase C (PKC), on gap junctional intercellular communication (GJIC) between thymic epithelial cells (TEC).</p> <p>Results</p> <p>Treatment with 8-Br-cAMP, a cAMP analog; or forskolin, which stimulates cAMP production, resulted in an increase in dye transfer between adjacent TEC, inducing a three-fold enhancement in the mean fluorescence of coupled cells, ascertained by flow cytometry after calcein transfer. These treatments also increased Cx43 mRNA expression, and stimulated Cx43 protein accumulation in regions of intercellular contacts. VIP, adenosine, and epinephrine which may also signal through cyclic nucleotides were tested. The first two molecules did not mimic the effects of 8-Br-cAMP, however epinephrine was able to increase GJIC suggesting that this molecule functions as an endogenous inter-TEC GJIC modulators. Stimulation of PKC by phorbol-myristate-acetate inhibited inter-TEC GJIC. Importantly, both the enhancing and the decreasing effects, respectively induced by cAMP and PKC, were observed in both mouse and human TEC preparations. Lastly, experiments using mouse thymocyte/TEC heterocellular co-cultures suggested that the presence of thymocytes does not affect the degree of inter-TEC GJIC.</p> <p>Conclusions</p> <p>Overall, our data indicate that cAMP and PKC intracellular pathways are involved in the homeostatic control of the gap junction-mediated communication in the thymic epithelium, exerting respectively a positive and negative role upon cell coupling. This control is phylogenetically conserved in the thymus, since it was seen in both mouse and human TEC preparations. Lastly, our work provides new clues for a better understanding of how the thymic epithelial network can work as a physiological syncytium.</p

    Bioactivity Evaluation of Plant Extracts Used in Indigenous Medicine against the Snail, Biomphalaria glabrata

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    This investigation examined the molluscicidal and larvicidal activity of eight plants that are used in the traditional medicine of the Pankararé indigenous people in the Raso da Catarina region, Bahia state, Brazil. The tested plants were chosen based on the results of previous studies. Only those plants that were used either as insect repellents or to treat intestinal parasitic infections were included in the study. Crude extracts (CEs) of these plants were tested for their larvicidal activity (against Aedes aegypti larvae in the fourth instar) and molluscicidal activity (against the snail Biomphalaria glabrata). The plant species Scoparia dulcis and Helicteres velutina exhibited the best larvicidal activities (LC50 83.426 mg/L and LC50 138.896 mg/L, resp.), and Poincianella pyramidalis, Chenopodium ambrosoides, and Mimosa tenuiflora presented the best molluscicidal activities (LC50 0.94 mg/L, LC50 13.51 mg/L, and LC50 20.22 mg/L, resp.). As we used crude extracts as the tested materials, further study is warranted to isolate and purify the most active compounds
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