O tratamento de questões sociocientíficas na formação de futuros professores de ciências: possibilidades e desafios nas vozes dos licenciandos

The perspective STSE (Science-Technology-Society-Environment) was recently implemented in the training courses for science teachers in Brazil, and proposes greater coordination of scientific knowledge with subjective questions that constitute the science, enables discussion of the nature of science and its implications for social and environmental issues. The present work aims to contribute to training of science teachers that approximates the current demands of contemporary society. Having as theoretical reasons the implications of STSE Movement in science teaching, we bring some considerations on pedagogical practices of undergraduates in Biological Sciences held within its Supervised. Through content analysis of the speeches of undergraduates, we can identify contributions and limitations that treatment of socio-scientific issues (SSI) revealed in the process, putting to discuss some aspects that are tangent training teachers committed to a contextualized view of science and scientific training. It discusses, among them, the relationship theory and practice in supervised training of future teachers’ conceptions about the implications of the STSE perspective in science teaching and science teacher positioning ahead controversial themes.

Relationship between global structural parameters and Enzyme Commission hierarchy: Implications for function prediction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A structure-activity relationship study of quinone compounds with trypanocidal activity

A set of 25 quinone compounds with anti-trypanocidal activity was studied by using the density functional theory (DFT) method in order to calculate atomic and molecular properties to be correlated with the biological activity. The chemometric methods principal component analysis (PCA), hierarchical cluster analysis (HCA), stepwise discriminant analysis (SDA), Kth nearest neighbor (KNN) and soft independent modeling of class analogy (SIMCA) were used to obtain possible relationships between the calculated descriptors and the biological activity studied and to predict the anti-trypanocidal activity of new quinone compounds from a prediction set. Four descriptors were responsible for the separation between the active and inactive compounds: T-5 (torsion angle), QTS1 (sum of absolute values of the atomic charges), VOLS2 (volume of the substituent at region B) and HOMO-1 (energy of the molecular orbital below HOMO). These descriptors give information on the kind of interaction that occurs between the compounds and the biological receptor. The prediction study was done with a set of three new compounds by using the PCA, HCA, SDA, KNN and SIMCA methods and two of them were predicted as active against the Trypanosoma cruzi. (c) 2005 Elsevier SAS. All rights reserved.

Quantum mechanical modeling of excited electronic states and their relationship to cathodoluminescence of BaZrO3

First-principles calculations set the comprehension over performance of novel cathodoluminescence (CL) properties of BaZrO3 prepared through microwave-assisted hydrothermal. Ground (singlet, s*) and excited (singlet s** and triplet t**) electronic states were built from zirconium displacement of 0.2 Å in {001} direction. Each ground and excited states were characterized by the correlation of their corresponding geometry with electronic structures and Raman vibrational frequencies which were also identified experimentally. A kind of optical polarization switching was identified by the redistribution of 4dz2 and 4dxz (Zr) orbitals and 2pz O orbital. As a consequence, asymmetric bending and stretching modes theoretically obtained reveal a direct dependence with their polyhedral intracluster and/or extracluster ZrO6 distortions with electronic structure. Then, CL of the as-synthesized BaZrO3 can be interpreted as a result of stable triplet excited states, which are able to trap electrons, delaying the emission process due to spin multiplicity changes. © 2013 AIP Publishing LLC.