J. Ullrich Physikalisches Institut der Universität, Pfaffenwaldring 57, D-7000 Stuttgart Z. Naturforsch. 40c, 685 — 692 (1985); received May 24, 1985 Rhodopseudomonas sphaeroides, Bacteriochlorophyll a, Bacteriopheophytin a, Bacteriopheophorbide a, Pigment aggregation A series of pigments of the bacteriopheophytin a spectral type have been isolated from ageing cultures of Rhodopseudomonas sphae...

The objective of the present study was to test the hypothesis that the acclimation to different light intensities in the diatom Phaeodactylum tricornutum is controlled by light quality perception mechanisms. Therefore, semi-continuous cultures of P. tricornutum were illuminated with equal amounts of photosynthetically absorbed radiation of blue (BL), white (WL), and red light (RL) and in combin...

Drawing upon reflectance behavior of woodland colors involving dark brown in the UV-Vis-IR bands, two colored pigments were used to print cotton/polyester Co/PET goods. Inorganic nanoparticles of TiO2, ZnO and AL2O3 were also loaded onto the printing formulation. The reflectance profile of treated samples was studied using Jasco V-670 reflectance spectrophotometer. SEM analysis of printed fabri...

The underwater environment places unique constraints on the vision of cetaceans compared to their terrestrial mammalian counterparts. Water absorbs and filters light affecting both the intensity and spectral distribution of light available for vision. Therefore, the aquatic environment restricts the spectral distribution of photons and limits the distance at which objects may be observed. The c...

L ight serves two major purposes in biological systems: the transduction of light to chemical free energy, photosynthesis, and the transduction of light to initiate a signaling pathway, to sense the environment. In animals, retinal pigments underlie signaling by light: vision and photoperiodism. Indeed, the use of retinal, the aldehyde of vitamin A, by visual pigments for their chromophore was ...

Electrical responses (ERG) to light flashes of various wavelengths and energies were obtained from the dorsal median ocellus and lateral compound eye of Limulus under dark and chromatic light adaptation. Spectral mechanisms were studied by analyzing (a) response waveforms, e.g. response area, rise, and fall times as functions of amplitude, (b) slopes of amplitude-energy functions, and (c) spect...

The eyes of crayfish were exposed to lights of known spectral composition, and the course of regeneration was followed in the dark by measuring the content of rhodopsin and metarhodopsin in single rhabdoms isolated at various times after the adaptation, using an assay that is based on the fluorescence of metarhodopsin. Complete recovery requires several days in the dark after intense adaptation...

Recent episodes of mass coral bleaching, the loss of symbiotic dinoflagellates or photosynthetic pigment from hermatypic corals, have been triggered by elevated sea temperatures. Photosynthetic irradiance is an important secondary factor. Host based pigments (pocilloporins or Green Fluorescent Protein homologues) have been proposed to reduce the impact of elevated temperature by shading the din...

The visual pigment present in the photoreceptor cells of the retina is a member of the family of G protein-coupled receptors and contains an 11-cis-retinal as a light-absorbing chromophore. Light induces conformational changes in the protein moiety of the visual pigment through cis-trans isomerization of the chromophore, which leads to the activation of a G protein-mediated signal transduction ...

Why do plants reflect in the green and have a "red edge" in the red, and should extrasolar photosynthesis be the same? We provide (1) a brief review of how photosynthesis works, (2) an overview of the diversity of photosynthetic organisms, their light harvesting systems, and environmental ranges, (3) a synthesis of photosynthetic surface spectral signatures, and (4) evolutionary rationales for ...