The Karhunen-Loève transform (KLT) is an optimal method for dimensionality reduction, widely applied in image compression, reconstruction and retrieval, pattern recognition and classification. The basic idea consists in evaluating, starting from a set of representative examples, a reduced space, which takes into account the structure of the data distribution as much as possible, and representin...

Australia has been cited as a weak link in anthropogenic models of megafauna extinction, but recent work suggests instead that the evidence for rapid extinction shortly after human arrival is robust. The global model is revisited, based on the contention that late Pleistocene megafauna extinctions took place rapidly on islands, and some islands (such as Australia and the Americas) are much larg...