Learning with simulations: Influence of a computer simulation with hand- on activities on students' learning of the physics capacitors' concepts

The persistence of this study was to investigate the contribution of a computer simulation to students´ learning of physics concepts (charging and discharging of capacitors). Interactive computer simulation (Crocodile simulation) was used to spread over the aim of this study. This attempt assesses the progress in understanding the concepts by grade 11 Scientific section after four complete periods (200 minutes) in two different situations: 1- using only a computer simulation; 2-using computer simulation with “hand- on” activities. The progress was measured through post-test. The results of both descriptive and inferential statistics show that the learners’ understanding of capacitors’ concepts that can be enhanced and were highly achieved when learners used the computer simulation combined with “hand- on” activities. The use of Hands-on activities was identified as the cause of this differentiation.

Xenotransplantation: history, problems and development prospects

The paper reviews the milestones and prerequisites in the history of the emergence and development of xenotransplantation. The currently existing barriers (immunological, infectious, genetic, ethical, and regulatory) to the development of this organ and tissue transplantation type have been studied. Available data on theoretical research and experimental studies have been reviewed. The prospects for performing xenotransplantation in various combination of species have been assessed. The forms and variants of the xenograft rejection reaction have been described. Genetic engineering approaches to overcoming xenoimmunological incompatibility are described. An assessment is made of ways to overcome existing barriers and prospects for the further development of xenotransplantation as a scientific section of transplantology.