We have explored the use of the Na+-H+ ionophore monensin as a potential tool for the investigation of membrane assembly and transport in retinal photoreceptors. Autoradiographic analysis of frog retinas incubated with [3H]leucine in the presence of monensin revealed a lack of concentrated silver grains ("bands") at the base of the rod outer segments, in contrast to controls. This is indicative...

Diffusion of a small tracer sphere (apoferritin) in isotropic and nematic networks [of fd virus] is discussed. For a tracer sphere that is smaller than the mesh size of the network, screened hydrodynamic interactions between the sphere and the network determine its diffusion coefficient. A theory is developed for such interactions as well as their relation to the long-time self-diffusion coeffi...

Mutations in the retinal pigment epithelium gene encoding RPE65 are a cause of the incurable early-onset recessive human retinal degenerations known as Leber congenital amaurosis. Rpe65-deficient mice, a model of Leber congenital amaurosis, have no rod photopigment and severely impaired rod physiology. We analyzed retinoid flow in this model and then intervened by using oral 9-cis-retinal, atte...

A rectangular rod is placed in a flow field flowing parallel to a flat plate. Effect of chord-thickness ratio of rectangular rod on developing vortex shedding downstream to the rod is studied. Then, for each one of the aspect ratios, the distance of the rod from the neighboring flat plate is reduced until the rod sticks to the flat plate. In each case, the effect of the flat plate boundary laye...

Attractive forces between anisotropic inclusions in the membrane of a vesicle The fluctuation-induced interaction between two rod-like, rigid inclusions in a fluid vesicle is studied by means of canonical ensemble Monte Carlo simulations. The vesicle membrane is represented by a triangulated network of hard spheres. Five rigidly connected hard spheres form rod-like inclusions that can leap betw...

The electrophoresis of a rigid sphere along the axis of a cylindrical pore is investigated theoretically. Previous analysis is extended to the case where the effects of double-layer polarization and electroosmotic flow can be significant. The influences of the surface potential, the thickness of the double layer, and the relative size of a pore on the electrophoretic behavior of a sphere are di...

A wrapping-on-a-rod technique is presented and demonstrated successfully to realize broadband microfiber-based highly birefringent (Hi-Bi) devices with 3D geometry. By wrapping a circular microfiber (MF) on a Teflon-coated rod (2 mm in diameter), a large and broadband birefringence can be obtained utilizing a rod-microfiber-air (RMA) structure. Wavelength scanning method is used to measure the ...