An exploratory study of gendered differences in young tourists perception of danger within London

This paper studies young tourists' perception of danger within the urban holiday environment of London, England. The study of perceived danger is important not only in its own right, but also because of the influence it may have on use of leisure spaces and times. This research assesses gender and group composition differences in perception of danger, addressing the relatively neglected issues of men's perception and the relationship between the genders. For the purpose of this paper 'danger' was assessed by studying how safe, relaxed, vulnerable, threatened, and at risk people felt while in London. The study found a number of similarities and differences between the men and women studied, in terms of how they perceived danger and their group composition during the day and nigh-time. These results indicate that gender may not be the only influence on perception and behaviour, and that men and women should not be regarded as-homogenous cohorts. (C) 2001 Elsevier Science Ltd. All rights reserved.

The last dicynodont: An Australian Cretaceous relict

Some long-forgotten fossil evidence reveals that a dicynodont (mammal-like reptile of the infraorder Dicynodontia) inhabited Australia as recently as the Early Cretaceous, ca. 110 Myr after the supposed extinction of dicynodonts in the Late Triassic. This remarkably late occurrence more than doubles the known duration of dicynodont history (from ca. 63 Myr to ca. 170 Myr) and betrays the profound impact of geographical isolation on Australian terrestrial faunas through the Mesozoic. Australia's late-surviving dicynodont may be envisaged as a counterpart of the ceratopians (homed dinosaurs) in Cretaceous tetrapod faunas of Asia and North America.

Coloured oil droplets enhance colour discrimination

The eyes of most diurnal reptiles and birds contain coloured retinal filters-oil droplets. Although these filters are widespread, their adaptive advantage remains uncertain. To understand why coloured oil droplets appeared and were retained during evolution, I consider both the benefits and the costs of light filtering in the retina. Oil droplets decrease cone quantum catch and reduce the overlap in sensitivity between spectrally adjacent cones. The reduction of spectral overlap increases the volume occupied by object colours in a cone space, whereas the decrease in quantum catch increases noise, and thus reduces the discriminability of similar colours. The trade-off between these two effects determines the total benefit of oil droplets. Calculations show that coloured oil droplets increase the number of object colours that can be discriminated, and thus are beneficial for colour vision.