Avaliação de métodos de escarificação na superação de dormência de chizolobium parahyba (vell.) blake (Fabaceae: caesalpinioideae)

Dormancy caused by the tegument's impermeability to water is a feature of Schizolobium parahyba seeds. So that the best methodology for overcoming the species's dormancy may be determined, the seeds were submitted to mechanical scarification treatments, using sandpaper and scissors, on the opposite side of the hilum. Chemical scarification was also undertaken with sulfuric (H2SO4) and hydrochloric (HCl) acids for 30 minutes. Seeds were distributed in groups of 25 units in four petri plates. The experiment was undertaken in a BOD germination chamber at 25°C and 120 μmol.m^-2.s^-1. Data were used to calculate the germination capacity (G%), the Germination Velocity Index (IVG) and Mean Germination Time (TM). Imbibation curve was also calculated to analyze the dormancy type of the seeds by using the three-phase model where phase FI was completed in 6 hours and FIII was initiated after 12 hours of imbibation. Results show that whereas pre-germinative treatments trigger S. parahyba germination, mechanical scarification is the most effective method to overcome the species's dormancy.

Focando na variação: Métodos e aplicações do conceito de diversidade beta em ecossistemas aquáticos

Ecologists usually estimate means, but devote much less attention to variation. The study of variation is a key aspect to understand natural systems and to make predictions regarding them. In community ecology, most studies focus on local species diversity (alpha diversity), but only in recent decades have ecologists devoted proper attention to variation in community composition among sites (beta diversity). This is in spite of the fact that the first attempts to estimate beta diversity date back to the pioneering work by Koch and Whittaker in the 1950s. Progress in the last decade has been made in the development both of methods and of hypotheses about the origin and maintenance of variation in community composition. For instance, methods are available to partition total diversity in a region (gamma diversity), in a local component (alpha), and several beta diversities, each corresponding to one scale in a hierarchy. The popularization of the so-called raw-data approach (based on partial constrained ordination techniques) and the distance-based approach (based on correlation of dissimilarity/distance matrices) have allowed many ecologists to address current hypotheses about beta diversity patterns. Overall, these hypotheses are based on niche and neutral theory, accounting for the relative roles of environmental and spatial processes (or a combination of them) in shaping metacommunities. Recent studies have addressed these issues on a variety of spatial and temporal scales, habitats and taxonomic groups. Moreover, life history and functional traits of species such as dispersal abilities and rarity have begun to be considered in studies of beta diversity. In this article we briefly review some of these new tools and approaches developed in recent years, and illustrate them by using case studies in aquatic ecosystems.

Extração de vias combinando métodos de detecção de regiões e linhas em imagens de intensidade de pulso laser

This paper aims at extracting street centerlines from previously isolated street regions by using the image of laser scanning intensity. In this image, streets are easily identified, since they manifest as dark, elongate ribbons contrasting with background objects. The intensity image is segmented by using the region growing technique, which generates regions representing the streets. From these regions, the street centerlines are extracted in two manners. The first one is through the Steger lines detection method combined with a line length thresholding by which lines being shorter than a minimum length are removed. The other manner is by combining the skeletonization method of regions based on the Medial Axis Transform and with a pruning process to eliminate as much as possible the ramifications. Experiments showed that the Steger-based method provided results better than the method based on skeletonization.

Determinação de GMP e CMP* no leite por métodos espectrofotométrico (ANSM) e cromatográfico (HPLC) - parâmetros metodológicos (*glicomacropeptídeo e caseinomacropeptídeo)

Glycomacropeptide is a glycosilated fraction of bovine kappa-casein that remains soluble when milk is clotted by rennin. Determinations of milk sialic acid content are useful because its concentration reflects the amount of free GMP of milk. In normal milk these amounts are very low, 12 to 16 times lower than in sweet whey. Therefore, its determination may be applied to verify possible frauds with whey addictions, since it works as a fingerprint. With the description of a new spectrophotometric method for determination of free GMP (ANSM) occurred a simplification of procedures, being faster than others (HPLC method), without loss of accuracy. However, due to variations of glycosilation in kappa-casein between animals, during the lactation period, due to mastitis and yet due to proteolysis on milk, it was necessary to know these variations to interpret correctly the analytical results. It was analyzed 1,703 samples of producer's raw milk and 1,189 samples of processed milk (HTST and UHT). The results showed that normal milk from herd (producer's milk) have only small amounts of free GMP, with A470nm = 0.232±0.088 or 3.89±1.25 mg of sialic acid/L. The upper limit of this distribution was A = 0.496; thus every bigger value may represent a problem, being outside of normal distribution.

Estado nutricional de mangueiras determinado pelos métodos DRIS e CND

Different procedures for the integrated method of diagnosis and recommendation may influence the accuracy of foliar diagnosis of mango. Thus, the objective of this study was to compare the diagnosis of nutritional status of mango obtained by different methods of assessing nutritional status, comparing multivariate relations (method CND) with bivariate relationships (DRIS) i.e., variations in the use of specific or preliminary standards and a logarithmic transformation of the data. The macro and micronutrient leaf analysis results of 63 mango orchards of Lower-middle São Francisco River Valley, Brazil, were used. To interpret nutritional status the Potential Response to Fertilization (PRA) criteria was used. The CND and DRIS methods, with and without logarithmic transformation and using specific or preliminary standards, which showed similar performance in assessing the nutritional status of the mango in Lower-middle San Francisco. Mango orchards in the semiarid region of northeast Brazil, the micronutrient deficiencies (Zn, Fe and Cu) were more frequent than macronutrient deficiency.

Avaliação in vitro de diferentes métodos de análises de fungitoxicidade de óleos essenciais

Environmental problems caused by synthetic fungicides have increased the search for alternative methods of control of plant diseases. The objective was to evaluate the effect of essential oil of citronella grass, on the fungus Rhizoctonia solani, in different methods of in vitro fungitoxicity. We used a randomized design in a factorial design with four replications, where the factors were composed of four methods for assessing the in vitro fungitoxicity of the essential oil of citronella grass (essential oil diluted in Tween 80 (0.5%) and embedded in the culture medium PDA (potato dextrose agar) still melting, essential oil diluted in Tween 80 (0.5%) and distributed on the surface of the PDA; oil essential diluted in Tween 80 (0.5%) and distributed on filter paper attached to the inner surface of the lid of the Petri dish, pure essential oil and distributed on the surface of the culture medium, and control) and five evaluation periods (2, 4, 6, 8 and 10 days of incubation). Was used 0.25μL mL-1 of citronella oil in all treatments. Of the treatments evaluated the use of pure oil distributed on the surface of the culture medium was more effective in reducing the mycelial diameter in all evaluations. In this method the rate of mycelial growth was 9,02 mm day-1, reaching in last evaluation 79,77 mm.

Desenvolvimento de métodos analíticos qualitativos para a análise de darunavir comprimidos

Darunavir is a protease inhibitor used in the treatment of HIV infection. It is a pillar of the drug cocktail for patients diagnosed with the virus. Quality control in the pharmaceutical industry, to verify the content of active substance and study the physicochemical characteristics of the drug, is essential to ensure final product quality. Until now, standardized methods for the analysis of darunavir have not been available in official compendia. This justifies new research, to develop and validate analytical methods, as well as physicochemical and pharmaceutical analysis for this drug, both as a raw material and a finished product. Thus, in this study, (a) the average weight of darunavir tablets and (b) the melting point of the pure drug were determined, and the following analytical techniques were performed: (c) thin-layer chromatography, (d) ultraviolet spectroscopy, (e) infrared spectroscopy and (f) high performance liquid chromatography. By developing the above techniques, it is possible to make a qualitative assessment of the quality of darunavir tablets.

Controle de mofo-cinzento (amphobotrys ricini) da mamoneira (ricinus communis l.) por métodos químico, biológico e com óleos essenciais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Métodos não convencionais para avaliação da porosidade e da densidade do solo de um latossolo vermelho

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)