Cat colour vision: one cone process or several?

L-cone pigment genes expressed in normal colour vision

To directly test the hypothesis that only two pigment genes are expressed from the X-chromosome array, we examined expressed M and L pigment gene sequences from > 100 male eye donors. In this sample, there were eight men who expressed high levels of more than one L pigment gene in addition to M pigment genes. The fact that these eyes expressed both L and M pigment genes at significant levels su...

F_0 estimation of one or several voices

A methodology is presented for fundamental frequency estimation of one or more voices. The signal is modeled as the sum of one or more periodic signals, and the parameters estimated by search with interpolation. Accurate, reliable estimates are obtained for each frame without tracking or continuity constraints, and without the use of specific instrument models (although their use might further ...

Colour-Vision and Colour-Blindness

Colour vision

The immense range of colours that we see belies the relative simplicity of the system underlying colour vision. We see colours because each of the three distinct types of cone photoreceptor in our retinae is sensitive to a different range of wavelengths of light. The L, M and S cones, colloquially called red (R), green (G), and blue (B), are selective for long, middle and short wavelengths, res...

Colour vision

Editorial Colour vision 2006 is an important bicentenary for the Ulster Medical Society. In 806, the Belfast Medical Society was founded and the later formation of the Belfast Clinical and Pathological Society in 853, allowed amalgamation of both societies to form the current Ulster Medical Society in 862. The vision of the early founders of the Belfast Medical Society, was far sighted, and som...