Associação de artropódes versus cactáceas nativas nos Estados da Paraíba e Pernambuco.

As cactáceas atualmente encontradas em áreas semi-áridas de todo mundo, são consideradas, em determinadas épocas do ano como única fonte de alimentos para os animais.Resumo 1608-1

Prospeccion biogeoquimica del oro en el yacimiento de Pau-a-Pique, Estado de Mato Grosso, Brasil

During the dry season (July-August 1997) eleven samples of soil-plant pairs were collected in the Pau-a-Pique gold deposit, southwestern of Amazonic Craton, about 440 km NW of Cuiabá city. The area contains rocks of Aguapeí Group, Rondonian Belt and recent cover. The area has a steep relief covered by thin soils. The vegetation is sparse and predominantly composed of xerophitic shrubs. Two kinds of plant species were sampled, one belonging to the Annonaceae family and the other one to the Piperaceae family. The ashes of these plants and the soils were analysed by INAA and ICP. The highest gold contents are found in the ashes of plants collected in the colluvium soil (white mica, clay minerals and Fe-oxyhydroxides) covering the hydrothermal halo of the deposit. In the soil, the highest gold values are those from eluvium related to the quartz veins. The higher gold values in plants respect to the soils suggest that the plants could be useful to establish hydrothermal targets.Se recogieron once muestras de pares suelo-planta durante la estación seca (julioagosto 1997) en el yacimiento de oro de Pau-a-Pique al suroeste del cratón Amazónico, unos 440 km al NO de la ciudad de Cuiabá. La geología de esta zona presenta rocas pertenecientes al Gmpo Aguapeí y al Cinturón Rondónico, así como sedimentos recientes de cobertera. La topografía presenta relieves abruptos y los suelos forman una delgada lámina. La vegetación es escasa y predominan los arbustos xerófitos. Se muestrearon dos especies de plantas, una de ellas perteneciente a la familia Annonaceae, y la otra a la familia Piperaceae. Las cenizas de estas plantas y de sus suelos fueron analizadas mediante las técnicas de INAA y ICP. Los más altos contenidos en oro se encontraron en las cenizas de las plantas recogidas en los coluviones (mica blanca, arcillas y oxihidróxidos de Fe) que recubren el halo hidrotermal de los depósitos. En el suelo, los valores más altos del oro corresponden a los productos relacionados con la meteorización de las vetas de cuarzo. El mayor contenido en oro en las plantas con respecto a los suelos sugiere que éstas pueden ser utilizadas para localizar posibles yacimientos hidrotermales

Prospecção de Dactylopius (Hemiptera, Coccoidea) na Paraíba, Pernambuco e Ceará em Opuntia ficus-indica.

A palma gigante (Opuntiaficus-indica) é a cultivar mais plantada na região nordeste do Brasil, devido a seu alto grau de resistência à seca e elevadas temperaturas, sua adaptabilidade a solos poucos férteis, alta produtividade decorrente da eficiência no uso da água, possibilitando a sobrevivênciade bovinos, caprinos e ovinos, nos períodos de seca e estiagem prolongadas.Resumo 1627-

Regioisomeric and substituent effects upon the outcome of the reaction of 1-borodienes with nitrosoarene compounds

A study of the reactivity of 1-borodienes with nitrosoarene compounds has been carried out showing an outcome that differs according to the hybridization state of the boron moiety. Using an sp2 boron substituent, a one-pot hetero-Diels–Alder/ring contraction cascade occurred to afford N-arylpyrroles with low to good yields depending on the electronic properties of the substituents on the borodiene, whereas an sp3 boron substituent led to the formation of stable boro-oxazines with high regioselectivity in most of the cases, in moderate to good yields. 1H and 11B NMR studies on two boro-oxazine regioisomers showed that selective deprotection can be performed. Formation of either the pyrrole or the furan derivative is pH- and regioisomer-structure-dependent. The results obtained, together with previous B3LYP calculations, support mechanistic proposals which suggest that pyrrole, or furan, formation proceeds via oxazine formation, followed by a boryl rearrangement and an intramolecular addition–elimination sequence

Algal Photosynthesis as the Primary Driver for a Sustainable Development in Energy, Feed, and Food Production

High oil prices and global warming that accompany the use of fossil fuels are an incentive to find alternative forms of energy supply. Photosynthetic biofuel production represents one of these since for this, one uses renewable resources. Sunlight is used for the conversion of water and CO2 into biomass. Two strategies are used in parallel: plant-based production via sugar fermentation into ethanol and biodiesel production through transesterification. Both, however, exacerbate other problems, including regional nutrient balancing and the world's food supply, and suffer from the modest efficiency of photosynthesis. Maximizing the efficiency of natural and engineered photosynthesis is therefore of utmost importance. Algal photosynthesis is the system of choice for this particularly for energy applications. Complete conversion of CO2 into biomass is not necessary for this. Innovative methods of synthetic biology allow one to combine photosynthetic and fermentative metabolism via the so-called Photanol approach to form biofuel directly from Calvin cycle intermediates through use of the naturally transformable cyanobacterium Synechocystis sp. PCC 6803. Beyond providing transport energy and chemical feedstocks, photosynthesis will continue to be used for food and feed applications. Also for this application, arguments of efficiency will become more and more important as the size of the world population continues to increase. Photosynthetic cells can be used for food applications in various innovative forms, e.g., as a substitute for the fish proteins in the diet supplied to carnivorous fish or perhaps—after acid hydrolysis—as a complex, animal-free serum for growth of mammalian cells in vitro

Marine Carotenoids: Biological Functions and Commercial Applications

Carotenoids are the most common pigments in nature and are synthesized by all photosynthetic organisms and fungi. Carotenoids are considered key molecules for life. Light capture, photosynthesis photoprotection, excess light dissipation and quenching of singlet oxygen are among key biological functions of carotenoids relevant for life on earth. Biological properties of carotenoids allow for a wide range of commercial applications. Indeed, recent interest in the carotenoids has been mainly for their nutraceutical properties. A large number of scientific studies have confirmed the benefits of carotenoids to health and their use for this purpose is growing rapidly. In addition, carotenoids have traditionally been used in food and animal feed for their color properties. Carotenoids are also known to improve consumer perception of quality; an example is the addition of carotenoids to fish feed to impart color to farmed salmon