The rice stem bug, Tibraca limbativentris Stal. (Hemiptera: Pentatomidae) is one of the most important pests of rice crops, especially irrigated crops. Plant defence strategies against these bugs may involve the emission of chemical compounds, which are released following herbivore attacks, directly or indirectly harming pest performance. The aim of this study was to evaluate the influence of constitutive and herbivory-induced volatiles from rice plants (Oryza sativa L.) on the behavioural responses of T. limbativentris adults and egg parasitoids Trissolcus basalis (Wollaston) and Telenomus podisi (Ashmead) (Hymenoptera, Platygastridae). Plant volatiles were collected from undamaged plants of the rice cultivar IRGA 424 and from plants that suffered herbivory by five males or five females of T. limbativentris. Air-entrainment extracts were analysed by GC-flame ionization detector and GC-MS, and insect responses evaluated in a 'Y' olfactometer. T. limbativentris feeding damaged on rice plants induced the release of 16 volatiles compounds in a higher amounts compared to undamaged plants The main compounds induced were (E)-2-hexenal, (E)-2-octen-1-ol, methyl salicylate and α-muurolene. Female bugs were significantly attracted to air-entrainment extracts containing volatiles from undamaged plants compared with air-entrainment extracts containing volatiles emitted from plants damaged by T. limbativentris, whereas males showed no preference. Telenomus podisi females were significantly attracted to volatiles from air-entrainment extracts of plants damaged by females, whereas T. basalis showed no preference. These results suggest that rice plants may be emitting defence compounds, which could be avoided by T. limbativentris females and also acted indirectly by attracting natural enemies.
Objetivo: identificar os saberes e práticas de saúde da população amazônica no uso das plantas medicinais. Método: A pesquisa refere-se a uma revisão integrativa da literatura científica realizada em publicações no período dos últimos cinco anos – de 2016 a 2021, em bases de dados BVS, LILACS, PubMed/Medline, e no Portal de periódicos da CAPES. Em todas as bases, os descritores usados foram “plantas medicinais” and “Amazônia”, com o operador booleano “and”. Resultados: Foram selecionados 11 artigos, que tratavam do conhecimento tradicional local sobre o uso de plantas medicinais como fundamental na manutenção da saúde nas comunidades amazônicas. Conclusão: o estudo permitiu apontara diversidade de plantas para a utilização e para o desenvolvimento de novos medicamentos, bem como a necessidade da valorização de conhecimento tradicional e sociocultural no uso dessas ervas, sejam em suas folhas, frutos, caules ou raízes.
Juventude extrativista como sujeito de participação e fortalecimento comunitário 11 AbstractThe youth and the younger generations have been gaining increasing recognition in the development of nations. In Brazil youth-related issues have been on the rise throughout the twenty-first century. A range of programs have been introduced by the federal government in order to create youth leaderships and value the youth. Although we are enjoying a good moment of demographic potentialities for the youth, there is a need for participatory research aimed at strengthening youth participation in protected areas. The aim of this article was to analyze the participation of the youth from Tefé National Forest (Floresta Nacional de Tefé), in the State of Amazonas, Brazil, regarding the educational challenges for popular participation. Thus, we believe that we can engage in dialogue with a view to finding viable alternatives that make training conditions possible as well as encouraging autonomy in the youth, which will help in strengthening the protected areas through collective youth empowerment.
Breast cancer patients with disseminated metastatic disease still have a very unfavorable prognosis. Investigations into the molecular mechanisms that underlie metastasis formation have a high priority and can possibly result in improved therapeutic interventions. The process of oncogenic epithelial to mesenchymal transition (EMT) has recently become a focus in cancer research because it encompasses many of the phenotypic traits characteristic of metastatic cells, e.g., increased motility, invasion, anoikis resistance, immunosuppression, and cancer stem cell potential. A number of central cellular signaling pathways and transcription factors have been implied in the control of EMT and metastasis formation, among them signal originating from the activation of the transforming growth factor β (TGFβ), epithelial growth factor, Wnt, Notch, and Hedgehog pathways. We have investigated the contribution of TGFβ signaling to metastasis-related cellular properties. TGFβ signaling can have tumor-suppressive and -promoting effects depending on the tumor type and the stage of tumor progression. TGFβ can inhibit the proliferation of mammary epithelial cells (MECs), but it can also induce EMT, invasion, and metastasis, possibly through Smad-independent signaling events. We investigated the effects of TGFβ pathway inhibition on the proliferation, differentiation, and invasion of both normal and malignant MECs. shRNA-mediated downregulation of the Smad4 protein in non-tumorigenic HC11 and tumorigenic 4T1 cells promotes the invasiveness of both cell lines. Mammary gland reconstitution studies, with primary MECs expressing shSmad4, resulted only in subtle effects on the glandular morphogenesis. Orthotopic transplantation of shSmad4-transduced 4T1 tumor cells caused the accelerated growth of mammary tumors and enhanced colonization and macroscopic lung metastases when compared to control cells. Surprisingly, the expression of Smad4 was restored, and a strong activation of Stat3 was found in the metastatic lesions present in the lungs. These lesions express metastatic factors, such as angiopoietin-like-4 and the inhibitor of DNA binding/differentiation 1. We suggest that the downregulation of Smad4 inhibits the tumor-suppressive effects of TGFβ signaling and enhances tumor growth. The downregulation, however, was only transient, and the reactivation of Smad4 expression caused the reversal of EMT, mesenchymal to epithelial transition, and thereby promoted metastasis formation in the lungs.
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