Relato de experiência exitosa na convivência com saúvas (Atta spp.) em sistema agroflorestal no Território do Recôncavo da Bahia.

A agricultura familiar no Brasil exerce importante papel como principal fonte de abastecimento de alimentos do mercado interno, gera renda e contribui para a produção agrícola brasileira. A técnica denominada agrofloresta ou Sistema Agroflorestal (SAF) é viável para a agricultura familiar por reunir vantagens econômicas, sociais e ambientais (CENSO AGROPECUÁRIO, 2006). Segundo Viana (1997), a busca de sistemas de produção apropriados em termos socioambientais e viáveis economicamente é um elemento central nas estratégias voltadas para o desenvolvimento rural sustentável

Evidence for Antisense Transcription Associated with MicroRNA Target mRNAs in Arabidopsis

Antisense transcription is a pervasive phenomenon, but its source and functional significance is largely unknown. We took an expression-based approach to explore microRNA (miRNA)-related antisense transcription by computational analyses of published whole-genome tiling microarray transcriptome and deep sequencing small RNA (smRNA) data. Statistical support for greater abundance of antisense transcription signatures and smRNAs was observed for miRNA targets than for paralogous genes with no miRNA cleavage site. Antisense smRNAs were also found associated with MIRNA genes. This suggests that miRNA-associated “transitivity” (production of small interfering RNAs through antisense transcription) is more common than previously reported. High-resolution (3 nt) custom tiling microarray transcriptome analysis was performed with probes 400 bp 5′ upstream and 3′ downstream of the miRNA cleavage sites (direction relative to the mRNA) for 22 select miRNA target genes. We hybridized RNAs labeled from the smRNA pathway mutants, including hen1-1, dcl1-7, hyl1-2, rdr6-15, and sgs3-14. Results showed that antisense transcripts associated with miRNA targets were mainly elevated in hen1-1 and sgs3-14 to a lesser extent, and somewhat reduced in dcl11-7, hyl11-2, or rdr6-15 mutants. This was corroborated by semi-quantitative reverse transcription PCR; however, a direct correlation of antisense transcript abundance in MIR164 gene knockouts was not observed. Our overall analysis reveals a more widespread role for miRNA-associated transitivity with implications for functions of antisense transcription in gene regulation. HEN1 and SGS3 may be links for miRNA target entry into different RNA processing pathways

Laser treatment of experimentally induced chronic arthritis

In this work, we investigated the effects of He-Ne laser irradiation on the inflammatory process induced in the articular cartilage of the right knee of guinea pigs. Through electron microscopy analysis it was possible to identify the induced arthritis in the articular cartilage and its modification after the laser treatment. The laser radiation promoted a reduction in the proliferation of the inflammatory cells in the damaged tissue and also induced the formation of cartilage bridges that tied the destroyed parts favoring the formation of a repaired tissue in the injured cartilage. (C) 2000 Elsevier B.V. B.V. All rights reserved

Investigação da cinética de sinterização para o estágio inicial no sistema SnO2: ZnO Investigation of the sintering kinetics for initial stage in SnO2: ZnO system

A sinterização do sistema SnO2:0,6 mol% ZnO, obtido via mistura de pós, foi investigada por dilatometria sob taxa de aquecimento constante de 2,5, 5,0 e 10,0 ºC.min-1. Os modelos clássicos de sinterização de Woolfrey-Bannister e Johnson foram utilizados para analisar o estágio inicial da sinterização e calcular a energia de ativação. Os valores de energia de ativação determinados por esses modelos são de 547 kJ.mol-1 e 511 kJ.mol-1 para Woolfrey-Bannister e Johnson, respectivamente. Verificou-se a coexistência de dois mecanismos de sinterização, difusão na rede e difusão por contorno de grão, para o estágio inicial da sinterização do sistema SnO2:0,6 mol% ZnO.The sintering of SnO2:0.6 mol% ZnO obtained by powder mixtures was investigated by dilatometry at constant heating rates 2.5, 5.0 and 10.0 ºC.min-1. Using classical sintering models of Woolfrey-Bannister and Johnson to analyze the initial stage sintering, the calculated activation energy was 547 kJ.mol-1 and 511 kJ.mol-1, respectively. The coexistence of the two sintering mechanisms, volume diffusion and grain boundary diffusion, was found to control the initial stage sintering of the SnO2:0.6 mol % ZnO system