Results 171 to 180 of about 8,717 (203)

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
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Melanopsin Forms a Functional Short-Wavelength Photopigment

Biochemistry, 2003
Recently, melanopsin has emerged as the leading candidate for the elusive photopigment of the mammalian circadian system. This novel opsin-like protein is expressed in retinal ganglion cells that form the retinohypothalamic tract, a neuronal connection between the retina and the suprachiasmatic nucleus.
Lucy A, Newman, Marquis T, Walker, R Lane, Brown, Thomas W, Cronin, Phyllis R, Robinson   +4 more
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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
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Studies on the photopigment system in Phycomyces

Biochemical and Biophysical Research Communications, 1970
Abstract Light-induced changes in optical density in the region of the action spectra of Phycomyces have been found in vivo and in vitro . The optical density changes are reversed after incubation in the dark for 5 to 12 min. Fluorescence excitation peaks at 345 and 460 nm are demonstrated to reflect the optical density changes ...
D S, Berns, J R, Vaughn
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Foveal dark adaptation, photopigment regeneration, and aging

Visual Neuroscience, 1992
AbstractFoveal dark adaptation in 58 subjects and photopigment regeneration in 60 subjects from 10–78 years of age exhibit parallel slowing of recovery rate with increasing age, with significant correlation of the two functions among individuals. The data are suggestive of an initial slight decline in rate before age 50, followed by a greater decline ...
D C, Coile, H D, Baker
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Densitometric measurement of human cone photopigment kinetics

Vision Research, 1983
We measured the radiance response function for steady state bleaching lights and the regeneration of the cone visual photopigments using the continuous recording densitometer described by v. Norren and v.d. Kraats. Measurements made on 5 deuteranopes, 1 protanope and 2 color-normal observers were similar. The radiance response function was steeper than
Smith, V.C., Pokorny, J., Norren, D. van
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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
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Photopigments des cônes humains

Documenta Ophthalmologica, 1969
On propose l'hypothese que les trois pigments photosensibles des cones de la retine humaine obeissent a la regle de Dartnall, c'est a dire que les courbes de leurs spectres d'action sont identiques a une translation pres, parallelement a l'axe des abscisses, quand celui-ci est gradue en frequences. Cette hypothese semble en bon accord avec l'experience
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Plant and fungal photopigments

Wiley Interdisciplinary Reviews: Membrane Transport and Signaling, 2012
AbstractLight is both an energy source and a carrier of information. Changes in light intensity, direction, quality, spectral composition, and the metronomic predictability of the Earths' light‐dark cycles carry vital information about the environment. Photoreceptors have evolved that sense these characteristics of light and trigger cellular signaling ...
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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
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