University of Coimbra

About: University of Coimbra is a education organization based out in Coimbra, Portugal. It is known for research contribution in the topics: Population & Mitochondrion. The organization has 14318 authors who have published 43067 publications receiving 994733 citations. The organization is also known as: UC & Universidade dos Estudos Gerais.

Particle swarm based Data Mining Algorithms for classification tasks

Abstract: Particle Swarm Optimisers are inherently distributed algorithms where the solution for a problem emerges from the interactions between many simple individual agents called particles. This article proposes the use of the Particle Swarm Optimiser as a new tool for Data Mining. In the first phase of our research, three different Particle Swarm Data Mining Algorithms were implemented and tested against a Genetic Algorithm and a Tree Induction Algorithm (J48). From the obtained results, Particle Swarm Optimisers proved to be a suitable candidate for classification tasks. The second phase was dedicated to improving one of the Particle Swarm optimiser variants in terms of attribute type support and temporal complexity. The data sources here used for experimental testing are commonly used and considered as a de facto standard for rule discovery algorithms reliability ranking. The results obtained in these domains seem to indicate that Particle Swarm Data Mining Algorithms are competitive, not only with other evolutionary techniques, but also with industry standard algorithms such as the J48 algorithm, and can be successfully applied to more demanding problem domains.

Antifungal activity of the essential oil of Thymus pulegioides on Candida, Aspergillus and dermatophyte species.

Abstract: The composition of the essential oil of Thymus pulegioides and its antifungal activity on Candida, Aspergillus and dermatophyte fungal strains were studied. Essential oil from the aerial parts of the plant was obtained by hydrodistillation and analysed by GC and GC-MS. The oil showed high contents of carvacrol and thymol. The MIC and minimal lethal concentration were used to evaluate the antifungal activity against Candida (seven clinical isolates and four ATCC type strains), Aspergillus [five clinical isolates, and two Coleccion Espanola de Cultivos Tipo (CECT) and two ATCC type strains] and five clinical dermatophyte strains. Antifungal activity was evaluated for the essential oil and for its main components. To clarify its mechanism of action on yeasts and filamentous fungi, flow-cytometric studies of cytoplasmic membrane integrity were performed, and the effect on the amount of ergosterol was investigated. Results showed that T. pulegioides essential oil exhibited a significant activity against clinically relevant fungi, mainly due to lesion formation in the cytoplasmic membrane and a considerable reduction of the ergosterol content. The present study indicates that T. pulegioides essential oil has considerable antifungal activity, deserving further investigation for clinical applications.