G-Protein receptor kinase 1 (GRK1) ("rhodopsin kinase") is necessary for the inactivation of photoactivated rhodopsin, the light receptor of the G-protein transduction cascade of rod photoreceptors. GRK1 has also been reported to be present in retinal cones in which its function is unknown. To examine the role of GRK1 in retinal cone signaling pathways, we measured in mice having null mutations...

The effects of prolonged (greater than 2 hr) darkness and background illumination on the light responsiveness of cone horizontal cells were examined in isolated, superfused white perch retinas. In retinas from fish maintained in complete darkness for more than 2 hr, cone horizontal cells had a resting membrane potential of about -18 mV, and they generated only slow, low-amplitude (3-4 mV) respo...

Chinese agricultural investments in the Southern Cone and Brazil-China soy-meat complex are playing a pivotal role international reordering of contemporary food regime. China's neo-mercantilist strategy, as exemplified by COFCO, carries elements both continuity rupture with this process. With an assertive yet flexible COFCO has adapted to internal requirements, specificities host countries, geo...

This paper first proposes a novel image separation method based on the hyperanalytic shearlet. By combining the advantages of both the hyperanalytic wavelet transform and the shear operation, hyperanalytic shearlet is easy to implement and also has a low redundancy. By using such transform and the orthonormal wavelet, a new geometric separation dictionary is obtained which can sparsely represen...

OBJECTIVE To report the clinical, functional, and in vivo microanatomic characteristics of a family with choroideremia with a deletion of the entire gene that encodes for the Rab escort protein 1 (CHM). METHODS We performed clinical examination, flash electroretinography (ERG), light- and dark-adapted perimetry, and optical coherence tomography; reviewed medical records; and obtained the medi...

PURPOSE To determine the temporal kinetics of the simultaneous translocation of arrestin and rod alpha-transducin in mice exposed to different lighting environments and to compare the subcellular compartmentation of cone alpha-transducin with arrestin. METHODS Double labeling immunofluorescence microscopy and image analysis are used to visualize and quantify the concentrations of rod arrestin...

Recent physiological evidence suggests that cones do not light adapt at low light levels. To assess whether adaptation is cone-selective at low light levels, the red-green detection mechanism was isolated. Thresholds were measured with a large test flash, which stimulated the L and M cones in different fixed amplitude ratios, on different colored adapting fields. Thresholds were plotted in L an...

The retina uses two photoreceptor types to encode the wide range of light intensities in the natural environment. Rods mediate vision in dim light, whereas cones mediate vision in bright light. Mouse photoreceptors include only 3% cones, and the majority of these coexpress two opsins (short- and middle-wavelength sensitive, S and M), with peak sensitivity to either ultraviolet (360 nm) or green...