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- Interactive and Multimedia Contents Associated with a System for Computer-Aided AssessmentPublication . Paiva, Rui; Ferreira, S. Milton; Mendes, G. Ana; Eusébio, M. J. AugustoThis article presents a research study addressing the development, implementation, evaluation, and use of Interactive Modules for Online Training (MITO) of mathematics in higher education. This work was carried out in the context of the MITO project, which combined several features of the learning and management system Moodle, the computer-aided assessment for mathematics STACK, the mathematical software GeoGebra, several packages from the type-setting program LaTeX, and tutorial videos. A total of 1,962 students participated in this study. Two groups of students taking a calculus course were selected for a deeper analysis. With regard to usability and functionality, the results indicate that MITO scored well in almost all aspects, which is fundamental for their introduction into formal university courses. The analysis of the data reveals that the use of MITO educational contents by students mainly occurs about 1 week and a half prior to the evaluations. Moreover, there is a strong correlation between the results of online assessments on MITO in a continuous assessment model and the final grade on the course.
- Coupled cell networks: Hopf bifurcation and interior symmetryPublication . Antoneli, Fernando; Dias, Ana; Paiva, RuiWe consider interior symmetric coupled cell networks where a group of permutations of a subset of cells partially preserves the network structure. In this setup, the full analogue of the Equivariant Hopf Theorem for networks with symmetries was obtained by Antoneli, Dias and Paiva (Hopf bifurcation in coupled cell networks with interior symmetries, SIAM J. Appl. Dynam. Sys. 7 (2008) 220-248). In this work we present an alternative proof of this result using center manifold reduction.
- Influence of Blood Contamination on Push-Out Bond Strength of Three Calcium Silicate-Based Materials to Root DentinPublication . Paulo, Cristina Rodrigues; Marques, Joana A.; Sequeira, Diana B.; Diogo, Patrícia; Paiva, Rui; Palma, Paulo J.; Santos, João MiguelA proper bond between root canal filling materials and dentin surface is essential to resist dislodgement and guarantee long-term success. Blood exposure is likely to occur in various clinical situations in which calcium silicate-based materials are used; therefore, it is fundamental to render data concerning the influence of blood on bond strength. The present study aims to evaluate the effect of blood contamination on the push-out bond strength obtained with three different biomaterials to root canal dentin; Ninety extracted human mono-radicular permanent teeth were selected. The root canals were prepared with Gates Glidden burs until a diameter of 1.10 mm was achieved. Teeth were then randomly divided into six experimental groups (n = 15) according to the presence/absence of blood contamination and biomaterial used for root canal filling (ProRoot® MTA, Biodentine™, and TotalFill® BC Putty). After one week, each root was sectioned in three segments (coronal, middle, and apical regions). Specimens were then submitted to push-out bond strength tests. Fracture pattern evaluation was performed. The significance level was set at 5%.; Blood contamination did not affect the push-out bond strength of any of the three tested calcium silicate-based cements (p > 0.05). Regardless of blood contamination, TotalFill showed statistically higher push-out bond strength when compared with Biodentine (p = 0.040) and MTA (p = 0.004). Biodentine exhibited higher bond strength than MTA (p = 0.043). Biomaterials’ comparison within each radicular segment revealed statistically superior bond strength of both Biodentine and TotalFill over MTA (p < 0.05) in the coronal segment. TotalFill presented higher push-out bond strength regarding the apical segment compared to Biodentine (p = 0.003). Fractures were mostly adhesive.; Overall results indicate TotalFill presents the highest push-out bond strength values, followed by Biodentine and, lastly, MTA. Blood contamination did not affect the dislodgement resistance. Biomaterials’ comparison within each radicular segment revealed both TotalFill and Biodentine as the preferable alternatives for application in the coronal region. TotalFill might be the biomaterial of choice for placement in the apical region.