7 research outputs found
Controversies or complexity in the relationship between temporal auditory processing and aging?
O presente artigo faz uma revisão breve da literatura sobre envelhecimento auditivo, abordando especificamente o envelhecimento do processamento temporal auditivo. São descritos os procedimentos experimentais para estudo de processamento temporal auditivo. São discutidos estudos sobre os efeitos do envelhecimento na detecção de interrupções em ruídos e tons puros, bem como estudos sobre a relação entre o processamento temporal auditivo e o reconhecimento de fala, entre sujeitos jovens e idosos. São descritas algumas das principais controvérsias sobre a relação entre processamento auditivo temporal e reconhecimento de fala. As diferenças entre os resultados encontrados nos estudos desta área são interpretadas em termos da complexidade dos procedimentos de avaliação de processamento temporal auditivo adotados. Finalmente, são apresentadas sugestões sobre direções futuras para pesquisa.The present article contains a brief review of the literature concerning auditory aging, describing specifical studies on aging of temporal auditory processing. Experimental procedures for research on temporal auditory processing are described. Studies about the effects of aging on the detection of gaps in noises and pure tones, as well as studies on the relationship between temporal auditory processing and speech recognition, among young and aged subjects, are discussed. Some of the main controversies about the relationship between temporal auditory processing and speech recognition are described. The differences found among the results of the studies in this area are interpreted in terms of the complexity of the procedures of assessment of temporal auditory processing adopted. Finally, suggestions about future directions of research are presented
Controvérsias ou complexidade na relação entre processamento temporal auditivo e envelhecimento?
Chemical composition and larvicidal activity of Rollinia leptopetala (Annonaceae)
The aim of present study was to describe the chemical composition of the essential oils from the leaf and stem of Rollinia leptopetala R. E. Fries (Annonaceae) and to evaluate the larvicidal activities of these essential oils, of the methanol extract from roots of this plant and of the oxoaporphine alkaloid, liriodenine (1) against the third-instar of Aedes aegypti larvae. The methanol extract from the roots showed larvicidal activity with LC50 64.6 ± 1.5 ppm. Higher activity was observed for the isolated alkaloid liriodenine (1), LC50 3.6 ± 0.4 ppm. The essential oils from the leaves and stems, also exhibited larvicidal activity with LC50 104.7 ± 0.2 and 34.7 ± 0.3 ppm, respectively. These results suggest R. leptopetala as a source of natural larvicidal compounds. This is the first report about the chemical composition and larvicidal activity of the leaf and stem essential oils of R. leptopetala