50 research outputs found

    Resistencia de cultivares de frijol (Phaseolus vulgaris) a Spodoptera frugiperda (Lepidoptera: Noctuidae).

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    Spodoptera frugiperda (Lepidoptera: Noctuidae) es una plaga que provoca daños en los cultivos de fríjol al reducir el área foliar y destruir las estructuras reproductivas. Este trabajo tuvo como objetivo evaluar los tipos y niveles de resistencia de cultivares de frijol a S. frugiperda. Los cultivares evaluados fueron: BRS Ametista, Pérola, BRS Notável, BRS Realce, Jalo Precoce, BRS Campeiro, BRS Agreste, BRS Cometa, BRS Executivo y BRS Pitanga, en el Laboratorio de Entomología Agrícola del Instituto Federal Goiano, Campus de Urataí, Brasil. Antixenosis, a libre y no libre escogencia y antibiosis se evaluaron en laboratorio (25 ± 2 °C, 70 ± 10 % HR y fotoperiodo 14 h). Los cultivares BRS Pitanga, BRS Executivo, BRS Notável y BRS Campeiro presentaron antixenosis y BRS Realce antibiosis a S. frugiperda. Sin embargo, no se sabe si los niveles de resistencia, exhibidos en el laboratorio, son suficientemente altos que representen un valor económico de campo para los agricultores. Por lo tanto, el próximo paso es evaluar, en condiciones de campo, los cultivares que mostraron mayor resistencia en las pruebas de laboratorio. Si las evaluaciones de campo indican niveles de resistencia suficientes, para tener un valor práctico, estos cultivares pueden utilizarse como fuentes en el programa de mejoramiento o ser utilizados directamente por los agricultores

    Comunidade de joaninhas (Coleoptera: Coccinellidae) em consórcio de couve (Brassica oleraceae var. acephala) com coentro (Coriandrum sativum) sob manejo orgânico.

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    As abordagens agroecológicas de produção orgânica vegetal visam a diversificação dos cultivos, estimulando a persistência, a abundância e a diversidade de inimigos naturais que atuam no controle biológico de insetos-pragas. Nesse contexto, o presente estudo teve por objetivos determinar a diversidade e a estrutura da comunidade de joaninhas predadoras (Coleoptera: Coccinellidae) associados a pulgões em couve, cultivada em consórcio com coentro. O estudo foi realizado na unidade experimental de produção integrada lavoura-pecuária denominada de Sistema Integrado de Produção Agroecológica, SIPA, em Seropédica, RJ. Os tratamentos foram consórcio de couve com coentro e o monocultivo de couve. A diversidade de joaninhas foi determinada por meio da coleta de indivíduos através de amostragens por remoção. Um total de 25 espécies de joaninhas está presente no SIPA. Não houve infestação por pulgões na couve consorciada com coentro, o qual foi usado pelas joaninhas como sítio de alimentação, oviposição, abrigo para larvas, pupas e adultos, além de acasalamento

    Copépodes e isópodes parasitos de nove espécies de peixes marinhos (Osteichthyes) do litoral do Estado do Rio de Janeiro, Brasil

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    Entre fevereiro de 2009 a junho de 2012, 368 espécimes de nove espécies de peixes marinhos (Osteichthyes) coletados ao longo da costa do Estado do Rio de Janeiro (21° - 23° S, 41° - 45° W), foram necropsiados para estudar sua fauna parasita de Copepoda e Isopoda. Foram identificadas 11 espécies de copépodes e três espécies de isópodes parasitos. Sendo coletados 852 espécimes de copépodes e quatro de isópodes. O mais prevalente e abundante dentre os crustáceos parasitos foi Taeniacanthus lagocephali Pearse, 1952, enquanto Coryphaena hippurus Linnaeus, 1758 foi a espécie de hospedeiro com a maior diversidade de espécies de ectoparasitos. Os gêneros Ceratothoa Dana, 1852 e Mothocya Hope, 1851 são registrados pela primeira vez para o Brasil neste estudo

    High-concentration carbamide peroxide can reduce the sensitivity caused by in-office tooth bleaching: a single-blinded randomized controlled trial

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    Objectives: A single-blinded, randomized, parallel clinical trial evaluated the use of 37% carbamide peroxide (CP) on bleaching effectiveness and tooth sensitivity reported by patients undergoing in-office tooth bleaching, in comparison with the results of using 35% hydrogen peroxide. Material and Methods:Forty patients were allocated to receive two sessions of in-office tooth bleaching using either 35% hydrogen peroxide (HP) or 37% CP. Each patient’s sensitivity level was evaluated during and up to 24 h after bleaching. The effectiveness of the bleaching procedures was evaluated with a spectrophotometer one week after each session and 30 days after the last session. The impact of tooth bleaching on the patients’ perceptions regarding smile changes, in addition to the bleaching procedures and their results, were also recorded. Absolute and relative sensitivity risks were calculated. Data on sensitivity level were analyzed using the Mann-Whitney or T-test, and data from the color evaluation were subjected to 2-way repeated measures ANOVA. Results: The use of CP reduced the risk and level of tooth sensitivity to values close to zero, whereas the difference between the bleaching agents disappeared after 24 h. An increased bleaching effect was observed for HP, mainly due to an improved reduction of redness and yellowness. Participants perceived improved tooth bleaching for HP and reduced sensitivity for CP, but no differences regarding the comfort of the techniques were noted. Conclusions: In our study, 37% CP resulted in reduced tooth sensitivity but decreased the tooth bleaching effectiveness. However, both bleaching agents resulted in high levels of patient satisfaction

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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