Lecithin retinol acyl transferase (LRAT) and retinal pigment epithelium protein 65 (RPE65) are key enzymes of the retinoid cycle. In Lrat(-/-) and Rpe65(-/-) mice, models of human Leber congenital amaurosis, the retinoid cycle is disrupted and 11-cis-retinal, the chromophore of visual pigments, is not produced. The Lrat(-/-) and Rpe65(-/-) retina phenotype presents with rapid sectorial cone deg...

The retinal cones of teleost fish contract at dawn and elongate at dusk. We have previously reported that we can selectively induce detergent-lysed models of cones to undergo either reactivated contraction or reactivated elongation, with rates and morphology comparable to those observed in vivo. Reactivated contraction is ATP dependent, activated by Ca2+, and inhibited by cAMP. In addition, rea...

A series of experiments has been conducted in the NASA HYPULSE Expansion Tube, in both CO2 and air test gases, in order to obtain data for comparison with computational results and to assess the capability for performing hypervelocity heat-transfer studies in this facility. Heat-transfer measurements were made in both test gases on 70 deg sphere-cone models and on hemisphere models of various r...

Mutations in the elongation of very long chain fatty acid 4 (ELOVL4) gene cause Stargardt macular dystrophy 3 (STGD3), a rare, juvenile-onset, autosomal dominant form of macular degeneration. Although several mouse models have already been generated to investigate the link between the three identified disease-causing mutations in the ELOVL4 gene, none of these models recapitulates the early-ons...

PURPOSE To define the nature and estimate the molecular weight range of soluble endogenous retinal trophic activities on cone photoreceptor survival in two models of cone degeneration. METHODS Diffusible factors from dissociated retinal cell cultures of 8-day normal-sighted (C57BL/6J) mice were tested for cone-survival-promoting activity by two approaches and by using two independent photorec...

In this paper we study a special class of convex optimization problems called conically ordered convex programs (COCP), where the feasible region is given as the level set of a vector-valued nonlinear mapping, expressed as a nonnegative combination of convex functions. The nonnegativity of the vectors is defined using a pre-described conic ordering. The new model extends the ordinary convex pro...

The shutoff mechanisms of the rod visual transduction cascade involve G-protein-coupled receptor (GPCR) kinase 1 (GRK1) phosphorylation of light-activated rhodopsin (R*) followed by rod arrestin binding. Deactivation of the cone phototransduction cascade in the mammalian retina is delineated poorly. In this study we sought to explore the potential mechanisms underlying the quenching of the phot...

PURPOSE Due to the low abundance of cone photoreceptors in the mouse retina and the scarcity of alternative animal models, little is known about mechanisms of cone degeneration. Nrl knockout mice develop exclusively the cone-type of photoreceptors. However, the cone photoreceptor layer in Nrl(-/-) mice displays an irregular morphology with severe rosette formation. Retinas of Rpe65(-/-);Nrl(-/-...

In this paper, we first present a new important property for Bouligand tangent cone (contingent cone) of a star-shaped set. We then establish optimality conditions for Pareto minima and proper ideal efficiencies in nonsmooth vector optimization problems by means of Bouligand tangent cone of image set, where the objective is generalized cone convex set-valued map, in general real normed spaces.