This study demonstrates that the color vision of foraging Japanese yellow swallowtail butterflies, Papilio xuthus, involves simultaneous color contrast. We trained newly emerged Papilio to select a disk of pale green among a set of differently colored disks presented on a black background. When the same set of disks was presented on blue background, the pale green-trained butterflies selected b...

Stigma is a crucial structure of female reproductive organ in plants. Stigma color is usually regarded as an important trait in variety identification in some species, but the molecular mechanism of stigma color formation remains elusive. Here, we characterized a tomato mutant, yellow stigma (ys), that shows yellow rather than typical green color in the stigma. Analysis of pigment contents reve...

Flesh color in Irish potato varieties ranges from almost pure white to a deep canary yellow. The yellowish tinge of "white-fleshed" varieties is intensified after dehydration, becoming a definite yellow if the tubers have been harvested in an immature state, as is the case with material grown in the south (1, 2). This residual yellow color, when it occurred, was at one time considered by the Ar...

BACKGROUND Color morphs of an insect species are known to vary in activities of detoxifying enzymes and associated susceptibility to insecticides. In Diaphorina citri, three color morphs are known to occur. In the present study, susceptibility to four insecticides was compared among gray/brown, blue/green and orange/yellow color morphs of field-collected D. citri. RESULTS The orange/yellow mo...

World knowledge influences how we perceive the world. This study shows that this influence is at least partly mediated by declarative memory. Dutch and German participants categorized hues from a yellow-to-orange continuum on stimuli that were prototypically orange or yellow and that were also associated with these color labels. Both groups gave more "yellow" responses if an ambiguous hue occur...

This paper reviews the published literature that is concerned with color vision impairment from industrial and environmental exposure to neurotoxic substances, and we evaluated whether testing for color vision impairment could be an affordable procedure for assessing these neurotoxic effects. In general, most cases of congenital color vision impairment are red-green, and blue-yellow impairment ...

BACKGROUND Individuals with attention-deficit/hyperactivity disorder (ADHD) are reported to manifest visual problems (including ophthalmological and color perception, particularly for blue-yellow stimuli), but findings are inconsistent. Accordingly, this study investigated visual function and color perception in adolescents with ADHD using color Visual Evoked Potentials (cVEP), which provides a...

A case of a predominantly yellow primary superficial spreading melanoma arising on the back of a 44-year-old woman is presented. Possible causes of the clinical and dermatoscopic yellow color are discussed. Staining with the histochemical stain, Sudan Black, revealed a differential uptake compared to a closely matched control melanoma. We speculate that the clinical and dermatoscopic yellow col...

BACKGROUND Computer image analysis techniques have decreased effects of observer biases, and increased the sensitivity and the throughput of immunohistochemistry (IHC) as a tissue-based procedure for the evaluation of diseases. METHODS We adapted a Cyan/Magenta/Yellow/Key (CMYK) model for automated computer image analysis to quantify IHC stains in hematoxylin counterstained histological secti...

Studies on the formation of ommochrome pigment granules are very few, despite their generalized occurrence as screening pigments in insect eyes. This is particularly true for ommochrome granules responsible for epidermal coloration. The aims of this study were to characterize the localization of major body pigments in a color changing mimetic spider, Misumena vatia (Thomisidae), and to describe...