Selective activity of diselenides against Aedes aegypti (Diptera: Culicidae) larvae

Abstract INTRODUCTION: Aedes aegypti (L.) is the major vector of arboviruses that causes serious public health concerns in tropical and subtropical countries. METHODS: We examined the larvicidal activity of 1,2-diphenyldiselenide [(PhSe)2] and 1,2-bis(4-chlorophenyl) diselenide [(p-ClPhSe)2] and determine its toxicity to different non-target organisms. RESULTS: (PhSe)2 and (p-ClPhSe)2 killed Ae. aegypti L3 larvae with LC50/24h values of 65.63 µM (20.48 mg/L) and 355.19 µM (135.33 mg/L), respectively. (PhSe)2 was not toxic to the four model organisms. CONCLUSIONS: (PhSe)2 is a larvicidal compound with selective action against Ae. aegypti larvae. The mechanisms of action of (PhSe)2 under field conditions remain to be investigated.

Effects of extrinsic feedback on the motor learning after stroke

Aim: This study aims to investigate the effects of the type of extrinsic feedback provided equally in terms of timing and frequency of delivery on the motor learning after stroke. Methods: Twenty post-stroke individuals were distributed randomly into two groups according to the type of feedback provided: knowledge of performance experimental group (KPEG) and knowledge of results experimental group (KREG). Additionally, a control group (CG) was consisted of 20 healthy individuals age- and feedback-matched with the experimental groups. The task was a pointing skill performed in a virtual reality system. The acquisition phase consisted of 3 days/ 75 trials per day. Two retention tests (ret1 and ret2) were run after four days from the acquisition phase. Dependent variable measures were defined by motor performance and movement pattern. Results: The statistical analysis showed interaction effect F(3,108 = 49.13, p = 0.01) among KPEG and KREG. Based on the motor performance parameters (score) the KPEG improved performance significantly from pre to post (p = 0.001), and maintain it from pre to ret1 (p = 0.002), and from the pre to ret2 (p = 0.001). However, the KREG only showed a difference in motor performance from the pre to post (p = 0.003). Compared to the KREG, the KPEG showed improvement on the movement pattern based on the smoothness (p = 0.004), which suggests that the KPEG performed more corrections of movements in relation to the CG and KREG groups. Conclusion: These findings suggest that KP allowed better motor learning in individuals after stroke.(AU)

Development of a transformation system for Penicillium brevicompactum based on the Fusarium oxysporum nitrate reductase gene

Penicillium brevicompactum é um fungo filamentoso que apresenta um potencial para a aplicacão industrial devido a sua eficiente producão de enzimas do complexo pectinolítico. Neste trabalho foi desenvolvido um sistema de transformacão heterólogo para P. brevicompactum baseado na complementacão de um mutante nitrato redutase. Mutantes nitrato redutase foram obtidos pela resistência ao clorato de sódio em uma taxa de 23,24per center. O mutante denominado 4457-18X foi escolhido para os experimentos de transformacão com o vetor pNH24, que contém o gene da nitrato redutase de Fusarium oxysporum. Uma freqüência de cerca de 3 transformantes/mg de DNA foi obtida utilizando-se o vetor pNH24 na forma circular e um aumento de cerca de 10 vezes nessa freqüência foi alcancado com a utilizacão desse vetor linearizado com a enzima de restricão Xba I. A análise dos transformantes pela técnica de hibridizacão revelou uma tendência do vetor linearizado diminuir o número de integracões em relacão ao vetor circular. A integracão foi aleatória e estável nos transformantes analisados. O estabelecimento de um sistema de transformacão para P. brevicompactum é essencial para a manipulacão genética desse microrganismo.