The application of artificial neural networks to the interpretation and classification of freshwater benthic invertebrate communities

This thesis presents a thorough and principled investigation into the application of artificial neural networks to the biological monitoring of freshwater. It contains original ideas on the classification and interpretation of benthic macroinvertebrates, and aims to demonstrate their superiority over the biotic systems currently used in the UK to report river water quality. The conceptual basis of a new biological classification system is described, and a full review and analysis of a number of river data sets is presented. The biological classification is compared to the common biotic systems using data from the Upper Trent catchment. This data contained 292 expertly classified invertebrate samples identified to mixed taxonomic levels. The neural network experimental work concentrates on the classification of the invertebrate samples into biological class, where only a subset of the sample is used to form the classification. Other experimentation is conducted into the identification of novel input samples, the classification of samples from different biotopes and the use of prior information in the neural network models. The biological classification is shown to provide an intuitive interpretation of a graphical representation, generated without reference to the class labels, of the Upper Trent data. The selection of key indicator taxa is considered using three different approaches; one novel, one from information theory and one from classical statistical methods. Good indicators of quality class based on these analyses are found to be in good agreement with those chosen by a domain expert. The change in information associated with different levels of identification and enumeration of taxa is quantified. The feasibility of using neural network classifiers and predictors to develop numeric criteria for the biological assessment of sediment contamination in the Great Lakes is also investigated.

Representing the Unrepresentable: The Photographs of Lee Miller at Buchenwald and Dachau

This article proposes a reflection on what the historian Saul Friedlander called ���the limits of representation��� of the massacres and genocides, in order to provide evidence to help settle the old debate about the Holocaust unrepresentability. To achieve this, we will carry out a textual analysis of five of the most painful images that the American photographer Lee Miller realized in the Nazi concentration camps of Buchenwald and Dachau, in April 1945. The war correspondent, who had been Man Ray���s assistant photographer, muse and lover, witnessed the horror, and if she knew how to represent it, that was, in a great extent, thanks to its surreal look.

Met��foras del amor en la poes��a de la Grecia antigua (I): la ��pica y la l��rica arcaicas

Partiendo del concepto de met��fora cognitiva, que complementa al m��s conocido de met��fora literaria, y analizando la base conceptual que a ambas subyace, pretendemos un cuidadoso an��lisis de los textos de poes��a ��pica y l��rica arcaicas, sin olvidar la importancia fundamental del contexto cultural en que estos surgen, para obtener una mejor comprensi��n de la forma en que los griegos conceptualizaban el sentimiento amoroso.

"Sub Tiberio quies"? Judaea���s Political Situation under the Prefects (6-41 c.e.), between Reality and Ideology

Deeply conflicting views on the political situation of Judaea under the Roman prefects (6-41 c.e.) have been offered. According to some scholars, this was a period of persistent political unrest and agitation, whilst according to a widespread view it was a quiescent period of political calm (reflected in Tacitus��� phrase sub Tiberio quies). The present article critically examines again the main available sources ���particularly Josephus, the canonical Gospels and Tacitus��� in order to offer a more reliable historical reconstruction. The conclusions drawn by this survey calls into question some widespread and insufficiently nuanced views on the period. This, in turn, allows a reflection on the non-epistemic factors which might contribute to explain the origin of such views.