Free radical scavenging activity of Pterogyne nitens Tul. (Fabaceae)

As part of our ongoing research on antioxidant agents from Brazilian flora, twenty extracts and fractions obtained from Pterogyne nitens Tulasne (Fabaceae) were screened for free radical scavenging activity by using ABTS [2,2’-azinobis(3-ethylenebenzothiazoline-6-sulfonic acid)] and DPPH (2,2-diphenyl-1-picrylhydrazyl-hydrate) radicals colorimetric assay and -carotene bleaching test. The strongest activity was found in ethyl acetate fraction from the stem barks, exhibiting IC50 values (inìg/ml) of 2.10 ± 0.1 and 10.2 ± 0.3 on ABTS•+ and DPPH•, respectively. Additionally, chromatographic fractionation of stem barks yielding myricetin, quercitrin and mirycetrin, three flavonols with remarkable antioxidant activity

Avaliação da aprendizagem: concepções de professores e alunos sobre a prática escolar na construção do conhecimento

This research aims to understand the students and Science teachers’ view about the learning evaluation by means of their teaching practices about knowledge construction in relation to the gaps that involve the school sphere, the didactic instruments used in the classroom, the way of evaluating and the structuring principles of the curriculum adopted in the teaching-learning process of the students. The research involved three public schools from the city of João Pessoa-Paraíba focusing on Secondary school 9th grade in Science classes. The methodology used was a qualitative approach, the data was collected through questionnaires applied to teachers and students mentioned above and was substantiated by the concepts of Piaget; Vygotsky; Hoffmann. After applying the questionnaires from the analysis made, It was known that most of the teachers use diagnostic and classificatory evaluations to verify the learning progress of the students and there is no appreciation for autonomy, previous knowledge, and social interactions. The results demonstrate that the teachers' conceptions are not in agreement with the theories about cognitive development and evaluation practice, even less educational documents that treat about this theme. It was clear that the teachers still need to review, to reflect and to plan their teaching methodology for obtaining good results and develop abilities that can improve the students cognition. The production of this work had the intention to contribute to Education, helping all the researchers to understand a little bit what happens to the teachers’ evaluation process through their practices and the learning of process of the students may look for new perceptions, constructivist understandings and evaluation about teaching-learning process that the students become capable individuals to idealize their own ideas about knowledge construction.O referido trabalho teve como objetivo compreender as concepções de alunos e professores sobre a avaliação da aprendizagem mediante a prática de ensino adotada na construção do saber, dos instrumentos avaliativos empregados em sala, do modo de avaliar e dos princípios estruturantes do currículo adotados no processo de ensino-aprendizagem do educando. A pesquisa envolveu três escolas da rede pública da cidade de João Pessoa-PB, que teve como foco turmas do 9º ano do ensino fundamental II ao ensino de ciências. Sendo aplicada a pesquisa qualitativa como metodologia adotada desse trabalho, os dados foram coletados através de questionários aplicados aos docentes e alunos das mencionadas turmas, que foram fundamentados nas teorias de Piaget; Vygotsky; Hoffmann. Após a aplicação dos questionários, a partir da análise realizada, foi verificado que a maioria dos docentes aplica para constatar o progresso da aprendizagem do alunado avaliações do tipo diagnóstica e classificatória e, que pouco prezam a autonomia, o conhecimento prévio, as interações sociais. Os resultados demonstram que as concepções dos docentes não estão em total concordância com as teorias sobre o desenvolvimento cognitivo e a prática avaliativa e, com os documentos educacionais que trata sobre o mencionado tema. Ficou evidente que os docentes ainda precisam rever, refletir e planejar sua metodologia de ensino para obtenção de bons resultados e desenvolver habilidades que possam melhorar a cognição dos educandos. A elaboração deste trabalho teve a intenção de contribuir para a educação, ajudando a todos os pesquisadores a entender um pouco sobre o que perpassar no processo avaliativo dos docentes mediante suas práticas e aprendizagem do educando, para que possam seguir em busca de novas percepções e compreensões construtivista do ensino-aprendizagem e da avaliação, onde os alunos se tornem indivíduos capazes de idealizar suas próprias idéias na construção do saber

Lipidomic profile as a non-invasive tool to predict endometrial receptivity in freeze-all cycles

sem informação331i336i336sem informaçãosem informaçãosem informaçã

Clonal diversity and conservation genetics of the medicinal plant Carapichea ipecacuanha (Rubiaceae)

The roots of the understorey shrub Carapichea ipecacuanha (ipecac) have medicinal properties, and the uprooting of wild plants has supplied most of the world demand for this species. Although under severe population decline, C. ipecacuanha lacks legal protection. In the wild, the aerial stems of ipecac clump together to form clusters with well-defined borders. Cluster size may range from several to hundreds of aerial stems. To investigate the extent of clonality among aerial stems in ipecac clusters, we sampled 50 wild clusters (a total of 291 aerial stems) and screened them with 89 inter-simple sequence repeat (ISSR) markers. The 291 aerial stems were grouped into 42 putative clones. The clonal groups generally consisted of aerial stems from the same cluster, and there was little or no genetic differentiation among aerial stems at the cluster level. These findings suggest that strategies designed to conserve ipecac in situ should not rely upon census data, which are based on the number of aerial stems per cluster and the number of clusters per population, because such data greatly underestimate the species effective population size and genetic diversity. Our results also indicate that this species needs protection at a federal level

Clustering Evolutionary Stock Market Model

As a typical representation of complex networks studied relatively thoroughly, financial market presents some special details, such as its nonconservation and opinions spreading. In this model, agents congregate to form some clusters, which may grow or collapse with the evolution of the system. To mimic an open market, we allow some ones participate in or exit the market suggesting that the number of the agents would fluctuate. Simulation results show that the large events are frequent in the fluctuations of the stock price generated by the artificial stock market when compared with a normal process and the price return distribution is a \emph{l\'{e}vy} distribution in the central part followed by an approximately exponential truncation.Comment: 9 pages, 8 figure