Wavelets and their associated transforms are highly efficient when approximating and analyzing onedimensional signals. However, multivariate signals such as images or videos typically exhibit curvilinear singularities, which wavelets are provably deficient of sparsely approximating and also of analyzing in the sense of, for instance, detecting their direction. Shearlets are a directional repres...

This paper introduces a Parseval frame of shearlets for the representation of 3D data, which is especially designed to handle geometric features such as discontinuous boundaries with very high efficiency. This system of 3D shearlets forms a multiscale pyramid of well-localized waveforms at various locations and orientations, which become increasingly thin and elongated at fine scales. We prove ...

BACKGROUND Although the circadian clock in the mammalian retina regulates many physiological processes in the retina, it is not known whether and how the clock controls the neuronal pathways involved in visual processing. METHODOLOGY/PRINCIPAL FINDINGS By recording the light responses of rabbit axonless (A-type) horizontal cells under dark-adapted conditions in both the day and night, we foun...

Sensory systems must avoid saturation to encode a wide range of stimulus intensities. One way the retina accomplishes this is by using both dim-light-sensing rod and bright-light-sensing cone photoreceptor circuits. OFF cone bipolar cells are a key point in this process, as they receive both excitatory input from cones and inhibitory input from AII amacrine cells via the rod pathway. However, i...

Simultaneous measurements of photocurrent and outer segment Ca2+ were made from isolated salamander cone photoreceptors. While recording the photocurrent from the inner segment, which was drawn into a suction pipette, a laser spot confocal technique was employed to evoke fluorescence from the outer segment of a cone loaded with the Ca2+ indicator fluo-3. When a dark-adapted cone was exposed to ...

BACKGROUND Intra-uterine growth restriction (IUGR) has been associated with increased predisposition to age-related complications. We tested the hypothesis that rat offspring models of IUGR would exhibit exacerbated, age-related retinal dysfunction. METHODS Female Sprague-Dawley rats (maintained at 11.5% O2 from gestational day 15 to 21 to induce IUGR) and control offspring (maintained at 21%...

PURPOSE To test the feasibility of scanning laser densitometry with a modified Rodenstock scanning laser ophthalmoscope (SLO) to measure the rod and cone photopigment distribution in patients with retinal diseases. METHODS Scanning laser densitometry was performed using a modified Rodenstock scanning laser ophthalmoscope. The distribution of the photopigments was calculated from dark adapted ...

Cones are primarily involved in photopic vision and light adaptation. Rods responsible for scotopic dark The typical time-courses of adaptations have been known century. However, information regarding the minimal adaptation time electroretinography (ERG) pupillography would be helpful practical applications clinical efficiency. Therefore, we investigated relationship between parameters ERG pupi...

We have examined the effects of changes in extracellular ionic composition on cone and retinal pigment epithelium (RPE) retinomotor movements in cultured isolated teleost retinas. In vivo, the myoid portion of teleost cones contracts in the light and elongates in the dark; RPE pigment disperses in the light and aggregates in the dark. In vitro, cones of dark-adapted (DA) retinas cultured in con...

Over the whole course of dark adaptation, light- and color detection thresholds were measured. At 6 degrees in the nasal visual field, the effect of wavelength was examined. After the rod-cone break (Kohlrausch kink), the color threshold began to rise while the light threshold was progressively decreasing. The rise of the color threshold was more remarkable as the test wavelength was more close...