Antocianinas em extratos vegetais: aplicação em titulação ácido-base e identificação via cromatografia líquida/espectrometria de massas

Anthocyanins extracted from picao, quaresmeira, petunia, flamboyant, purple ipe, lobeira, pata de vaca, jaboticaba, purple cabbage and jambul were evaluated as natural acid-base indicators. Anthocyanins in extracts were identified using HPLC/MS. Clear, rapid change in color at final-point titration was observed for extracts but only picao showed strong change in pH. Indirect determination of carbonate in limestone using a natural indicator was performed and results compared with phenolphthalein indicator and potentiometer titration. Optimal results were obtained with picao but other extracts showed good accuracy and precision.

Structural aspects and floristic similarity among tropical dry forest fragments with different management histories in northern Minas Gerais, Brazil

In order to produce useful knowledge to the initiatives of protection and management of forest fragments, more specifically for tropical dry forests which suffer with frequent anthropic activities, and due to the lack of specific studies, this article aimed describe the structure and the floristic similarity among three areas of dry forest with different management histories. The study was developed in Capitão Enéas municipality, Northern Minas Gerais, Brazil, where three fragments were evaluated, being one in regeneration for 30 years, another submitted to occasional fire and the third with selective cut in small scale. The sampling was developed through the point quarter method considering all the alive phanerophyte individuals with circumference at breast height (CBH) > 15 cm. In the three fragments, 512 individuals, distributed in 60 species, 47 genera, and 23 families were sampled. The most representative families were Fabaceae (26), Anacardiaceae (4), Bignoniaceae (3) and Combretaceae (3). However, fourteen families were represented by only one species. Only eight species were common to all fragments - Myracrodruon urundeuva standed out with 26.9% of all sampled individuals - while a great number of species were exclusive of each fragment. The floristic and structural differences between the fragments are possibly related to the history and intensity of management in each area besides the topography variations and the presence or absence of limestone outcrops. These results show the importance of each fragment, indicating that the loss of anyone would cause negative impacts on the regional flora and consequently to the associated biodiversity.

SUBSTRATE, LIME, PHOSPHORUS AND TOPDRESS FERTILIZATION IN MACAW PALM SEEDLING PRODUCTION

ABSTRACT The macaw palm [Acrocomia aculeata (Jacq.) Lood. ex Mart] has been domesticated to subsidize biodiesel production programs in Brazil. However, little is known about the seedling production of this species. This study aimed to evaluate substrate mixtures, limestone and phosphorus rates for substrate amendment and topdressing frequency in macaw palm seedlings. Three trials were conducted in a greenhouse up to six months of nursery cultivation. Trial 1: determination of percent mineral and organic fractions of seven substrate mixtures. Trial 2: evaluation of four limerates for soil amendment versus four phosphorus rates. Trial 3: evaluation of N, K and Mg topdressing frequency. Significant differences were found in the three trials for most of the variables (plant height, leaf number, shoot dry mass, root dry mass, vigor and bulb diameter). The main results obtained were as follow: Trial1 - the best seedling growth was observed in substrates with at least 25% organic matter. Trial2 -lime rates ranging from 0.50 to 1.25 kg associated with 3 to 4 kg of single superphosphate per m3 of substrate provided the best seedling growth. Trial 3 - topdressing fertilization provided better development of seedlings regardless of frequency.

Producción mediática y religiosidad: dinámicas transnacionales de las comunicaciones evangélicas

La circulación internacional de bienes simbólicos a través de los medios de comunicación ha generado numerosos debates sobre los modos de interpretar y analizar los procesos comunicacionales en las tramas culturales contemporáneas. En este trabajo nos referimos a la conformación de una cadena de radiofonía evangélica con sede en Miami, integrada por radios afiliadas que retransmiten la señal en distintas ciudades de Latinoamérica. Las características de esta red nos permiten indagar las problemáticas de la globalización, transnacionalización y localización cultural en el ámbito de la religiosidad y los medios de comunicación. Profundizamos en las articulaciones espaciales, las mediaciones culturales y las interrelaciones entre iglesias, medios de comunicación y públicos evangélicos configuradas en el contexto de la producción cultural evangélica internacional.