Results 131 to 140 of about 3,923 (179)

Mapping cone photopigment optical density

Journal of the Optical Society of America A: Optics and Image Science, and Vision, 1993
The distribution of cone photopigment across the retina affects the amount of light captured by cones at each retinal location. Cone photopigment optical density is measured in two ways, with reflectometry and/or with color matching. Color matching measures a higher optical density than does reflectometry.
Ann E Elsner, Stephen A Burns
exaly   +3 more sources

The effects of photopigment depletion on brightness and threshold

Vision Research, 1978
Abstract Viewing an intense light depletes the store of regenerated photopigment within the receptors, thereby reducing the proportion of quanta in a subsequent stimulus that can be absorbed by the regenerated photopigment. This effect of photopigment depletion is often thought to play an insignificant role in the adaptation process.
Wilson S Geisler
exaly   +3 more sources

Insect Photopigments: Photoreceptor Spectral Sensitivities and Visual Adaptations

2014
The spectral sensitivity of photoreceptors is primarily determined by the expressed rhodopsins. After a brief introduction to the photochemistry of insect rhodopsins, the relatively simple case of bee visual pigments and photoreceptors is described, followed by the more complicated cases of butterflies and flies.
Arikawa, Kentaro, Stavenga, Doekele G.
openaire   +1 more source

Photopigments and photoentrainment in the Syrian golden hamster

Brain Research, 1997
The Syrian golden hamster (Mesocricetus auratus) is an important model in the study of circadian rhythms. However, as in other mammals, little is known about the photoreceptors that mediate circadian entrainment. Using immunocytochemistry and RNA blot hybridization, we found no evidence for the presence of blue-/UV-sensitive opsin.
M, von Schantz, S M, Argamaso-Hernan, A, Szél, R G, Foster   +3 more
openaire   +2 more sources

Individual differences in photopigments

Annual Meeting Optical Society of America, 1986
Variations in color vision have long been understood as reflecting variations in the photopigment complement. Beyond those photopigment variations that account for the differences between the classical color vision phenotypes, there are several lines of evidence to suggest further variation in the spectral positioning of photopigments found in ...
Jay Neitz, Gerald H. Jacobs
openaire   +1 more source

Cone photopigments in nocturnal and diurnal procyonids

Journal of Comparative Physiology A, 1992
Procyonids are small, New World carnivores distributed among some 6 genera. Electroretinogram (ERG) flicker photometry was used to measure the spectra of the cone photopigments for members of two nocturnal species, the raccoon (Procyon lotor) and the kinkajou (Potos flavus), and a diurnal species, the coati (Nasua nasua).
G H, Jacobs, J F, Deegan
openaire   +2 more sources

The Photopigments in an Insect Retina

1973
Colour vision is not an exclusive property of vertebrates. Also insects can discriminate wavelengths. The best known example is the honeybee, as shown by training experiments (1) and electrophysiological recordings (2,3). The peripheral wavelength discrimination is accomplished by at least three receptor types. The spectral sensitivity of the receptors
G. Höglund, K. Hamdorf, H. Langer, R. Paulsen, J. Schwemer   +4 more
openaire   +1 more source

Absorption characteristics of oriented photopigments in microvilli

Biological Cybernetics, 1976
We have analysed the effects of photopigment orientation in microvilli membranes on the absorption properties of rhabdomeres.
J N, Israelachvili, M, Wilson
openaire   +2 more sources

Looking at a circadian photopigment

Trends in Neurosciences, 2001
The photopigments in the human eye that transduce light for vision are known, but now a group of volunteers has given up several nights of sleep to help researchers better understand how the human eye transduces light for circadian and neuroendocrine effects as well. Each night, the subjects’ pupils were dilated and exposed to a different wavelength of
openaire   +1 more source

Photopigments of the lateral eye ofLimulus

Journal of Comparative Physiology ? A, 1976
Photoreceptor membrane fractions of the lateral eye ofLimulus were solubilized in the detergent emulphogene, and three photobleachable materials were observed with respectiveλ max values at 330nm±10nm, 450 nm±10 nm, and 530 nm±10 nm. A530 is the pigment which had been reported earlier by Hubbard and Wald (1960), and it can be separated from A330 and ...
R. M. Benolken, Maureen B. Maude, Robert E. Anderson   +2 more
openaire   +1 more source