We propose a generic pigment model suitable for digital painting in a wide range of genres including traditional Chinese painting and water-based painting. The model embodies a simulation of the pigment-water solution and its interaction with the brush and the paper at the level of pigment particles; such a level of detail is needed for achieving highly intricate effects by the artist. The simu...

Microtubule (MT)-based organelle transport is driven by MT motor proteins that move cargoes towards MT minus-ends clustered in the cell center (dyneins), or plus-ends extended to the periphery (kinesins). Cells are able to rapidly switch the direction of transport in response to external cues, but the signaling events that control switching remain poorly understood. Here, we examined the signal...

The characteristic dark color of Diadema antillarum is chiefly attributable to a black pigment, most of which is contained in large epidermal chromatophores (see Fig. 1). A red pigment is also present, but is easily separable from the black, being readily soluble in ethanol and acetone, whereas the black is not. The nature of the red pigment is unknown and we have not studied its properties. Co...

In the teleost eye, the melanin granules of the retinal pigment epithelium (RPE) move in response to changes in light conditions. In the dark, pigment granules aggregate toward the cell base, and in the light, they disperse into long apical projections. Isolated RPE cells from the green sunfish (Lepomis cyanellus) were used to investigate the mechanism and regulation of pigment movement. Changi...

When 3,4-dihydroxyphenylalanine is oxidized in the presence of phenol oxidases (2,3) or by silver oxide (4), a red pigment is formed. Enzymically, this pigment is converted to a melanin. In the absence of enzyme, it has been shown that the pigment may rearrange to either Zcarboxy-5,6-dihydroxyindole or to 5,6-dihydroxyindole (5). The structure of the red pigment has therefore been inferred to b...

A study was made of the diffusion of the red pigment echinochrome from the eggs of the sea urchin, Arbacia punctulata, into sea water. Unfertilized eggs retained their pigment, over periods of hours. Outward diffusion of pigment from unfertilized eggs normally is entirely negligible, or does not occur at all. Enchancing the calcium or potassium content of the artificial sea water (while retaini...

Diaryl azo pigments play an important role as yellow pigments for printing inks, with an annual pigment production of more than 50,000 t. The crystal structures of Pigment Yellow 12 (PY12), Pigment Yellow 13 (PY13), Pigment Yellow 14 (PY14), and Pigment Yellow 83 (PY83) were determined from X-ray powder data using lattice energy minimizations and subsequent Rietveld refinements. Details of the ...

PURPOSE Orange pigment is an important sign of malignancy in melanocytic tumors. There is a question as to whether the pigment accumulation is inside of macrophages or retinal pigment epithelial (RPE) cells. We investigated which cells are involved with this color alteration. METHODS We examined enucleated specimens from two patients with choroidal melanoma and dense orange pigment on fundus ...

Pigment patterns of fishes are a tractable system for studying the genetic and cellular bases for postembryonic phenotypes. In the zebrafish Danio rerio, neural crest-derived pigment cells generate different pigment patterns during different phases of the life cycle. Whereas early larvae exhibit simple stripes of melanocytes and silver iridophores in a background of yellow xanthophores, this pi...