O aproveitamento do resíduo da indústria do sisal no controle de larvas de mosquitos

Descreve-se o aproveitamento do resíduo do desfibramento das folhas de Agave sisalana, como um larvicida para o combate a mosquitos transmissores de doenças tropicais. Durante 24 horas, larvas de Aedes aegypti e Culex quinquefasciatus foram expostas a concentrações diferentes do extrato da planta para determinar as concentrações letais. Para A. aegypti foi constatada a CL50 em 322ppm e para C. quinquefasciatus em 183ppm. Foi investigada a ação de saponinas existentes na planta, ficando evidenciado que o resíduo de A. sisalana é ativo através da interação de vários dos seus componentes. Este extrato poderá ser utilizado em campo, na concentração de 100ppm para C. quinquefasciatus com um aumento do tempo de exposição para três dias, obtendo-se uma mortalidade de 100% das larvas. Este produto, porém, não é recomendado para o controle de A. aegypti, devido à necessidade de uma alta concentração para a obtenção de 100% de mortalidade das larvas e ao fato destas se desenvolverem preferencialmente em água potável.

Various pyrethroids on bednets and curtains

Verandah trap huts in Tanzania village were used to assess the effectiveness if impregnated bednets and curtains in preventing hut entry and feeding by, and in killing of, Anopheles gambiae and An. funestus. Permethrin, deltamethrin, lambdacyhalothrin and pyrethrum were used for impregnation of damaged or undamaged bednets, sisal eaves curtains or bed curtains made of polypropylene fibre. The performance of the synthetic pyrethroids did not differ statistically significantly, except that on a damage net permethrin was better at preventing feeding. sisal eaves curtains deterred mosquitoes from hut entry but did not kill those that had entered. In assessing damaged nets and curtains it must be recognised that anything less than the best vector control may have no appreciable impact on holoendemic malaria.

Institutional entrepreneurship and professionalization of the rural development of the sisal region in Brazil

This work analyses the professionalization of rural development in the Brazilian Northeastern region and how this created opportunities for entrepreneurship when the professional practices of funding bodies were transformed in accordance with local reality. This professionalization has its own characteristics, including fluid formats and the rolling out of networks, and it contributes to the theorization and dissemination of certain practices instead of being concentrated in professional associations and formal links with educational institutions. The main implications are commonly related to institutional processes related to professionalization, such as the emergence of certain organizational formats and the dissemination of professional practices that are considered legitimate. An additional consequence was observed in the area of rural development: the ideas and practices disseminated through professionalization were reinterpreted when the local entrepreneurs adapted them to their own thinking and needs.

DIETARY FIBRE CONTENT, PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY IN SOURSOPS (Annona muricata L.)

ABSTRACT Healthy eating is associated with the consumption of fruits, which are notable for their beneficial effects on human health. The aim of this study was to evaluate the proximate composition, composition of fibers and components with antioxidant activity in soursops varieties Crioula, Lisa and Morada of physiological maturity (PM) and mature (M). The protein, lipid and moisture contents did not differ between soursop varieties, but the ash contents were higher in the Morada-PM (0.56%±0.03) and the Morada-M (0.82%±0.10) varieties. The Crioula-M variety showed higher levels of total dietary fibre (5.76%±0.12). The Lisa-M variety showed higher levels of insoluble dietary fibre (4.46%±0.00). The Lisa-M variety also showed a higher level of phenolic compounds (284.25 mg gallic acid/100 g of soursop pulp), differing significantly (p <0.05) from the Crioula-PM soursop (154.40 mg of gallic acid/100 g of soursop pulp). Under the DPPH• system, the soursops that showed highest antioxidant activity were the Crioula-M (EC50 of 156.40 g.g DPPH-1) and the Crioula-PM (EC50 of 162.41 g.g DPPH-1), which differed significantly from the Morada soursops. The results suggest that the consumption of soursops is useful for increasing concentrations of bioactive compounds and dietary fibre.

Características físicas e químicas de substratos à base de pó de coco e resíduo de sisal para produção de mudas de sabiá (Mimosa caesalpiniaefolia Benth)

O experimento foi instalado com o objetivo de analisar as características físicas e químicas ocorridas em substratos com diferentes concentrações de pó de coco (PC), resíduo de sisal (RS) e Argissolo Vermelho- Amarelo distrófico (Arg), no crescimento de mudas de sabiá (Mimosa caesalpiniaefolia Benth), produzidas em recipientes com capacidade para 2 dm³. O delineamento utilizado foi o inteiramente casualizado, com 13 tratamentos e quatro repetições, contendo oito vasos por repetição, num total de 416 unidades amostrais. Avaliaram-se as características físicas e químicas, bem como as variáveis da altura total das plantas e do diâmetro do coleto a cada 30 dias, a área foliar, o número de folhas e a massa seca da parte aérea. Recomenda-se o uso de pó de coco como componente para substratos, pois suas propriedades físicas e químicas, aliadas à sua estrutura e durabilidade, apresentaram condições para a produção de mudas de sabiá. Não se recomenda o uso do resíduo de sisal como componente para substratos na produção de mudas de sabiá, pois esse resíduo revelou valores de condutividade elétrica (CE) e pH inadequados ao cultivo.

Characterization and treatment of sisal fiber residues for cement-based composite application

Sisal fiber is an important agricultural product used in the manufacture of ropes, rugs and also as a reinforcement of polymeric or cement-based composites. However, during the fiber production process a large amount of residues is generated which currently have a low potential for commercial use. The aim of this study is to characterize the agricultural residues by the production and improvement of sisal fiber, called field bush and refugo and verify the potentiality of their use in the reinforcement of cement-based composites. The residues were treated with wet-dry cycles and evaluated using tensile testing of fibers, scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Compatibility with the cement-based matrix was evaluated through the fiber pull-out test and flexural test in composites reinforced with 2 % of sisal residues. The results indicate that the use of treated residue allows the production of composites with good mechanical properties that are superior to the traditional composites reinforced with natural sisal fibers.