Detecção de elementos estranhos em modelos inspirados em imunologia

Mestrado em Engenharia FísicaNeste trabalho é apresentado um algoritmo para detecção de elementos estranhos (nonself) baseado no mecanismo de Frustração Celular. Este mecanismo apresenta uma nova abordagem às interacções celulares que ocorrem no sistema imunológico adaptativo. O conceito é o de que qualquer elemento estranho estabelecerá interacções menos frustradas do que os restantes elementos do sistema, podendo por isso, através do seu comportamento anómalo, ser detectado. O algoritmo proposto possui vantagens em relação aos sistemas imunológicos artificiais mais conhecidos. Entre elas está a possibilidade de obter detecção perfeita com um número reduzido de detectores. Nesta tese, analisa-se comparativamente este algoritmo com algoritmos de selecção negativa existentes na literatura.In this work an algorithm for nonself detection is presented, based on the Cellular Frustration mechanism. This mechanism presents a novel approach to cellular interactions occurring in the adaptive immune system. The concept is that any nonself element will establish less frustrated interactions than the remaining elements of the system, can thus, by its anomalous behaviour, be detected. The proposed algorithm has advantages over the most know artificial immune systems. Among the advantages there is the possibility to achieve perfect detection using a reduced number of detectors. In this thesis, this algorithm is analysed comparatively to negative selection algorithms that can be found in literature

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved