PURPOSE To identify changes in S- and M-sensitive cone opsin gene expression following retinal detachment (RD) and reattachment. METHODS Cat retinas were detached for 1, 3, 7, or 28 days, or reattached after 1 h, 1 day, or 3 days of RD and fixed in 4% paraformaldehyde. Pieces of mid-peripheral retina were removed from the same region of each detached, normal (attached), and reattached retina ...

‎let $g$ be a finite group and $nu(g)$ denote the number of conjugacy classes of non-normal subgroups of $g$‎. ‎in this paper‎, ‎all nilpotent groups $g$ with $nu(g)=3$ are classified‎.

The early zebrafish brain contains a simple axon scaffold of longitudinal tracts connected by commissures. Neurons in the nucleus of the posterior commissure (nuc PC) project growth cones along a specific route in this axonal scaffold, raising the possibility that specific axons in the early scaffold guide nuc PC growth cones. We tested this possibility by analyzing the behavior of nuc PC growt...

We measured frequency-of-seeing curves for tiny (1.125 and 3.375 min arc) stimuli flashed briefly at absolute threshold to estimate the density of foveal cones in normals and in subjects with Stargardt's macular dystrophy. Foveal absolute thresholds for Stargardt's were elevated 1.5 log units over normal. Analysis using Poisson counting statistics indicated that the quantal absorption to stimul...

Given a flat, projective morphism Y → T from an equidimensional scheme to a nonsingular curve and a subscheme Z of Y , we give conditions under which specialization of the Segre class s(NZY ) of the normal cone of Z in Y implies flatness of the normal cone. We apply this result to study when the relative tangent star cone of a flat family is flat.

1. The tangent cone. We can estimate the directional derivative and gradient of a smooth function quickly and easily using finite difference formulas. While rather inaccurate, such estimates have some appeal, needing neither calculus rules nor even a closed-form expression for the function. In the variational geometry of sets, the role of derivatives and gradients are played by the cones of “ta...

The normal cone to a constraint set plays a key role in optimization theory, algorithms, and applications. We consider the question of how to approximate the normal cone to a set under the assumption that the set is provided through an oracle function or collection of oracle functions, but contains some exploitable structure. We provide a new simplex gradient based approximation technique that ...

Neurons of the nucleus of the posterior commissure (nuc PC), an identifiable cluster of neurons in the embryonic zebrafish brain, project growth cones ventrally along the posterior commissure to the anterior tegmentum where the PC intersects two longitudinal tracts, the tract of the postoptic commissure (TPOC) and the medial longitudinal fasciculus (MLF). Once at the intersection, nuc PC growth...

the big eye kilka, clupeonella grimmi, is a marine fish living in depth of 20 to 200 meter of the caspian sea. its eye and retina were processed for histological and sem studies. paraffin embedded retina was cut radially and tangentially in 5 ?m thickness and stained with hematoxylin and eosin method. the unstained sections were manipulated for sem image observations. tangential retinal section...