293 resultados para 1384
Resumo:
Three new C-glucosylxanthones, 2-(2'-O-trans-caffeoyl)-C-beta-D-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone (1), 2-(2'-O-trans-cinnamoyl)-C-beta-D-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone (2), and 2-(2'-O-trans-coumaroyl)-C-beta-D-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone (3), were isolated from the stems of Arrabidaea samydoides, in addition to three known C-glucosylxanthones, mangiferin (4), 2-(2'-O-benzoyl)-C-beta-D-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone (5), and muraxanthone (6). Their chemical structures were assigned on the basis of MS and 1D and 2D NMR experiments. Xanthones 1-6 showed moderate free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) as well as antioxidant activity evidenced by redox properties measured on ElCD-HPLC.
Resumo:
The objective of this study was to investigate the influence of different levels of biofertilizers from cattle and swine manure on the structural, morphogenetic and productive characteristics of Brachiaria brizantha cv. Piata. The experiment was arranged in a completely randomized factorial design with split plots. The plots were defined by eight treatments: two biofertilizers (cattle and swine), four levels (0, 100, 200 and 300 kg N.ha(-1)) and subplots by four different cutting periods. The cutting for plant uniformity was performed at 45 days after sowing at 15 cm above the soil surface. The biofertilizeres were applied in a single level, after the cutting of plants, in rates of 0, 0.23 and 0.19, 0.45 and 0.38, 0.68 and 0.57 liters pot(-1) for the biofertilizers from cattle and swine manure, respectively. These rates were also equivalent to levels of 0, 100, 200 and 300 kg N.ha(-1). There was no significant difference between the types of biofertilizers as there was no interaction between them and the different levels, hence both biofertilizers could be applied without any loss of nutrient intake by the plants used in this experiment. There was a significant difference between the production of green and dry matter, the leaf appearance rate, phyllochron, leaf and pseudostem elongation rates, number of green leaves, final leaf length, number and weight of tillers, according to the increase of nitrogen rates, following linear prediction model. Effect of the cutting periods was also observed, once the plants harvested during the summer presented greater performance of structural and morphogenetic characteristics.
Resumo:
The effect of propylthiouracil oral treatment (400 mg/day per bird for 20 days) on body and thyroid weight, rectal temperature and plasma metabolic parameters of ducks (Cairina moschata) was determined. Propylthiouracil treatment produced a reduction (P less than .01) in body weight and an increase (P less than .01) in thyroid weight. The antithyroid drug also produced a decrease in rectal temperature starting from the 15th day of treatment, but did not significantly change blood glucose. Plasma free fatty acids and cholesterol concentrations progressively increased from the 5th and 10th day, respectively, in treated animals.
Resumo:
The present paper evaluates meta-heuristic approaches to solve a soft drink industry problem. This problem is motivated by a real situation found in soft drink companies, where the lot sizing and scheduling of raw materials in tanks and products in lines must be simultaneously determined. Tabu search, threshold accepting and genetic algorithms are used as procedures to solve the problem at hand. The methods are evaluated with a set of instance already available for this problem. This paper also proposes a new set of complex instances. The computational results comparing these approaches are reported. © 2008 IEEE.
Resumo:
Incluye bibliografía
Resumo:
The text analyzes the debates put forward in the defense for a humanist curriculum in the Brazilian secondary schools me the period from 1920 and 1960. Basing on the articles published in the periodic of national circulating and texts by educators who problematize the question f humanism as the orientation guide for the curriculum, the text highlights the positions of the intellectuals connected to the Catholic Churcho beside the thoughts of the secondary school teachers and the intellectuals of the progressive tendency. The analyses also show how the humanism notion is going to be transformed along the twentieth century and how this notion was enrooted in the Brazilian culture.
Resumo:
The central theme of this article is the research in education. The aim is to bring up the contribution developed by Mirian Limoeiro Cardoso in Brazil for the production of knowledge in education, besides the propositions of foreign authors, often used as references to base of the research. The starting point, here described, is the statement that the empirical real is not the object of knowledge, but what is presented as an object to be known, is always the real that, in different forms, is an object involved by theory. Thinking about the research in this view the necessecity of revision of the meaning of the object to be known, the object that is also an educative action in its different and several manifestations and the discussion of its importance for the teachers? and researchers? formation.
Resumo:
This paper discussed the professor's role in teacher education during the trainee activities. Several scenarios were identified in the literature and the potential improvement that tutorial actions could have was highlighted. Three main dimensions of tutorial actions were proposed: education is to advise for life, to advise is to support the student to perceive alternative processes, attitudes and perceptions and to advise is to develop the student towards his or her learning process. It is proposed that the professor exercise educational tutoring and not only specific tutoring, these last ones usually focused on the classroom only.
Resumo:
Includes bibliography
Resumo:
Incluye Bibliografía
Resumo:
Incluye Bibliografía
Resumo:
Incluye Bibliografía
Resumo:
Construction techniques with ruler and the compasses, fundamental on Euclidean geometry, have been related to modern algebraic theories such as solving equations and extension of bodies from the works by Paolo Ruffini (1765-1822), Niels Henrik Abel (1802-1829) and Evariste Galois (1811-1832). This relation could provide an answer to some famous problems, from ancient Greece, such as doubling the cube, the trisection Angle, the Quadrature of the Circle and the construction of regular polygons, which remained unsolved for over two thousand years. Also important for our purposes are the notions of algebraic numbers, transcendental and the criteria for constructability, of those numbers. The objective of this study is to reconstruct relevant steps of geometric constructions with ruler (unmarked) and the compasses, from the elementary to the outcome buildings, in the nineteenth century, considering those mentioned problems.
Resumo:
Based on Clovis Bevilaqua’s four biographies which present three stigmas of the character - being the son of a priest, engaged in a large grammatical legal controversy with Rui Barbosa in making the Civil Code of 1917 and married to a wife of exotic modes - we discuss the built memory of Amelia Carolina Freitas Bevilaqua, who is marked as a pioneer of the feminist movement in Brazil and also upstart writer who aspired to join the Brazilian Academy of Letters. Among other negative adjectives, she was sloppy, not vain and misaligned in dress, futile or adulterous.