Technology and innovation in teaching genetics: project-based learning in the construction of cloning strategies

Project-based learning (PBL) is an active student-centred form of instruction that uses a project as a central vehicle of knowledge acquisition. Besides its high potential in developing structured thinking, constructive investigations, and improving the students’ responsibility and autonomy, this methodology is not strongly applied in Science degrees, where standardised tests and fixed protocol-driven laboratorial applications are still the dominant ways to assess academic achievement. This research involved the implementation of a PBL in teaching gene cloning strategies to third-year students of the BSc Biotechnology course. The methodology was conducted in four stages, integrating two curricular units, Genetic Engineering, and Integrated-Laboratories VB. Firstly, the project was conceptualised in Genetic Engineering theoretical classes with tutorial support. Secondly, the planned protocol was applied in the laboratory with tutor supervision. Thirdly, collaboration, communication, and reflection skills were emphasized with a poster presentation. Finally, an evaluation questionnaire was applied. The study's main findings were: 1) none of the students have ever had PBL, 2) the majority of students achieved better comprehension and acquired stronger theoretical knowledge, 3) they gained more autonomy in the laboratory, and 4) strongly recommended this methodology. However, students also acknowledged that the PBL approach was more time and study demanding.A aprendizagem baseada em projetos (ABP) é uma forma ativa de ensino centrada no estudante que usa um projeto como veículo central de aquisição de conhecimento. Apesar do elevado potencial para desenvolver um pensamento estruturado, investigações construtivas e promover responsabilidade e autonomia, esta metodologia não é usualmente aplicada nas licenciaturas em Ciências, onde testes padronizados e práticas laboratoriais com protocolos fixos ainda são as formas dominantes de avaliação. Este estudo envolveu a implementação da ABP no ensino de estratégias de clonagem, com estudantes do terceiro ano da Licenciatura em Biotecnologia. A metodologia foi desenvolvida em quatro etapas, integrando duas unidades curriculares, Engenharia Genética e Laboratórios VB. Inicialmente, o projeto foi conceptualizado nas aulas teóricas de Engenharia Genética com suporte tutorial. Posteriormente, o protocolo planeado foi implementado no laboratório com supervisão. Em terceiro, as competências de colaboração, comunicação e reflexão foram enfatizadas com a apresentação de um poster. Por fim, foi aplicado um questionário de avaliação. As principais conclusões foram: 1) nenhum dos estudantes tinha experienciado a ABP, 2) a maioria compreendeu e adquiriu conhecimentos teóricos mais sólidos, 3) adquiriram mais autonomia no laboratório e 4) recomendam fortemente. No entanto, os estudantes reconheceram que a ABP consistiu numa aprendizagem mais exigente.info:eu-repo/semantics/publishedVersio

Performance of two-dimensional Doppler echocardiography for the assessment of infarct size and left ventricular function in rats

Although echocardiography has been used in rats, few studies have determined its efficacy for estimating myocardial infarct size. Our objective was to estimate the myocardial infarct size, and to evaluate anatomic and functional variables of the left ventricle. Myocardial infarction was produced in 43 female Wistar rats by ligature of the left coronary artery. Echocardiography was performed 5 weeks later to measure left ventricular diameter and transverse area (mean of 3 transverse planes), infarct size (percentage of the arc with infarct on 3 transverse planes), systolic function by the change in fractional area, and diastolic function by mitral inflow parameters. The histologic measurement of myocardial infarction size was similar to the echocardiographic method. Myocardial infarct size ranged from 4.8 to 66.6% when determined by histology and from 5 to 69.8% when determined by echocardiography, with good correlation (r = 0.88; P < 0.05; Pearson correlation coefficient). Left ventricular diameter and mean diastolic transverse area correlated with myocardial infarct size by histology (r = 0.57 and r = 0.78; P < 0.0005). The fractional area change ranged from 28.5 ± 5.6 (large-size myocardial infarction) to 53.1 ± 1.5% (control) and correlated with myocardial infarct size by echocardiography (r = -0.87; P < 0.00001) and histology (r = -0.78; P < 00001). The E/A wave ratio of mitral inflow velocity for animals with large-size myocardial infarction (5.6 ± 2.7) was significantly higher than for all others (control: 1.9 ± 0.1; small-size myocardial infarction: 1.9 ± 0.4; moderate-size myocardial infarction: 2.8 ± 2.3). There was good agreement between echocardiographic and histologic estimates of myocardial infarct size in rats