Video lectures and online activities to engage students in a flipped classroom

In recent years there have been several proposals for alternative pedagogical practices. Most of these proposals are based in the, so called, “active learning”, in opposition to the common “passive learning”, which is centered on transmission of information inside classrooms as well as recognized as teacher-centered procedure. In an active learning pedagogical structure, students have a more participative role in the overall learning/teaching process, being encouraged to face new learning challenges like, for instance, solving problems and developing projects, in an autonomous approach trying to make them, consequently, able to build their own knowledge. The flipped or “inverted” classroom is one of these active learning pedagogical methodologies that emphasizes a learner-centered instruction. According to this approach, the first contact that students have with the content on a particular curriculum subject is not transmitted by the lecturer in the classroom, this teaching strategy requires students to assess and analyze the specific subject before attending to class, therefore the informational component from the lecture is the homework, and class time is dedicated to exercises and assignments, always with support from the instructor, who acts as a facilitator, helping students when needed and offering supplementary explanation as required. The main objective of this paper is to discuss and explore how the use of different types of instructional videos and online activities may be implemented in the flipped classroom procedure (as means of incorporating new content and teaching new competencies) and to describe students’ perceptions of this approach within a course in a Higher Education Institution (HEI), presenting some positive and negative features of this pedagogical practice.

Molecular and biochemical mechanisms involved in the toxicity of a marine cyanobacteria compound on cancer cell lines

In recent years marine biotechnology has revealed a crucial role in the future of bioindustry. Among the many marine resources, cyanobacteria have shown great potential in the production of bioactive compounds with diverse applicability. The pharmacological potential of these organisms has been one of the most explored areas in particular its antibacterial, antifungal and anticancer potential. This work was based on the assessment of potential anticancer compound E13010 F 5.4 isolated from marine cyanobacteria strain Synechocystis salina LEGE 06099. Thus the aim of this work was to explore molecular and biochemical mechanisms underlying the bioactivity detected in human cancer cells, specifically in lines RKO colon carcinoma and HT-29. The isolation of the compound was performed from biomass obtained by large-scale culture. To obtain the compound fractionation was carried and confirmation and isolation performed by Nuclear Magnetic Resonance (NMR), Thin Layer Chromatography (TLC) and High-Performance Liquid Chromatography (HPLC). Cell viability assays were performed based on reduction of 3- (4,5-dimetiltiaziol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) to assess the cytotoxic potential of the compound. From the battery of cell lines RKO (colon carcinoma), HT-29 (colorectal adenocarcinoma), MG-63 (osteosarcoma) and T47D (breast carcinoma) the cell lines RKO and HT-29 were selected for elucidation of mechanisms of cytotoxicity. For the elucidation of the mechanisms involved in cytotoxicity the cell lines RKO and HT29 were exposed to the compound. A genomic approach based in the mRNA expression of genes involved in apoptosis and cell cycle by Real-Time PCR and a proteomic approach based on the separation of proteins by two-dimensional electrophoresis (2DGE) was performed. For mRNA expression were selected the genes RPL8, HPRT1, VDAC, SHMT2, CCNE, CCNB1, P21CIP, BCL-2 and BAD and for proteomics isoelectric focussing between 3 – 10 and molecular weight of 19 – 117 kDa separated by polyacrylamide gels (2DGE). The MTT results confirmed the reduction of the cell viability. The RT-PCR results for the expression of genes studied were not yet fully elucidative. For the cell line RKO there was a significant reduction in the expression of the gene P21CIP, and a tendency for reduction in the BAD gene expression and for increased expression of gene CCNB1, pointing to an effort for cell proliferation. In HT-29 cell line, there was a tendency for increase in the expression of P21CIP and BAD, which may explain the reduction in cell viability. The 2DGE results indicate proteomic patterns with differentially altered spots in the treated and control cells with both qualitative and quantitative differences, and differences in response between the RKO and HT-29 cell lines.