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An important topic in genomic sequence analysis is the identification of protein coding regions. In this context, several coding DNA model-independent methods, based on the occurrence of specific patterns of nucleotides at coding regions, have been proposed. Nonetheless, these methods have not been completely suitable due to their dependence on an(More)
We have examined the functional architecture of the turtle Pseudemys scripta elegans retina with respect to colour processing, extending spectral stimulation into the ultraviolet, which has not been studied previously in the inner retina. We addressed two questions. (i) Is it possible to deduce the ultraviolet cone spectral sensitivity function through(More)
Motivated by a recently proposed biologically-inspired face recognition approach, psychophysical experiments have been carried out. We measured recognition performance of polar frequency filtered face images using an 8alternatives forced-choice method. Test stimuli were generated by converting the images from the spatial to the polar frequency domain using(More)
To study processing of UV stimuli in the retina of the turtle, Trachemys dorbignii, we recorded intracellular responses to spectral light from 89 cells: 54 horizontal (47 monophasic, five (R/G) biphasic and two (Y/B) triphasic), 14 bipolar, 12 amacrine, and nine ganglion cells. Spectral sensitivities were measured with monochromatic flashes or with the(More)
Recent electrophysiological studies indicate that cells in the LGN, V1, V2, and V4 areas in monkeys are specifically sensitive to Cartesian, polar and hyperbolic stimuli. We have characterized the contrast sensitivity functions (CSF) to stimuli defined in these coordinates with the two-alternatives forced-choice paradigm. CSFs to Cartesian, concentric, and(More)
Recent physiological experiments support behavioral and morphological evidence for a fourth type of cone in the turtle retina, maximally sensitive in the ultraviolet (UV). This cone type has not yet been included in the models proposed for connectivity between cones and horizontal cells. In this study, we examined the inputs of UV, S, M, and L cones to(More)
We investigated the color vision pattern in Cebus apella monkeys by means of electroretinogram measurements (ERG) and genetic analysis. Based on ERG we could discriminate among three types of dichromatic males. Among females, this classification is more complex and requires additional genetic analysis. We found five among 10 possible different phenotypes,(More)
We present a novel local-based face verification system whose components are analogous to those of biological systems. In the proposed system, after global registration and normalization, three eye regions are converted from the spatial to polar frequency domain by a Fourier-Bessel Transform. The resulting representations are embedded in a dissimilarity(More)
We present an automatic face verification system inspired by known properties of biological systems. In the proposed algorithm the whole image is converted from the spatial to polar frequency domain by a Fourier-Bessel Transform (FBT). Using the whole image is compared to the case where only face image regions (local analysis) are considered. The resulting(More)