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Color Discrimination (color + discrimination)
Selected AbstractsDissecting the pathogenic mechanisms of mutations in the pore region of the human cone photoreceptor cyclic nucleotide-gated channel,HUMAN MUTATION, Issue 7 2010Katja Koeppen Abstract The CNGA3 gene encodes the A3 subunit of the cone photoreceptor cyclic nucleotide-gated (CNG) channel, an essential component of the phototransduction cascade. Certain mutations in CNGA3 cause autosomal recessive achromatopsia, a retinal disorder characterized by severely reduced visual acuity, lack of color discrimination, photophobia, and nystagmus. We identified three novel mutations in the pore-forming region of CNGA3 (L363P, G367V, and E376K) in patients diagnosed with achromatopsia. We assessed the expression and function of channels with these three new and two previously described mutations (S341P and P372S) in a heterologous HEK293 cell expression system using Western blot, subcellular localization on the basis of immunocytochemistry, calcium imaging, and patch clamp recordings. In this first comparative functional analysis of disease-associated mutations in the pore of a CNG channel, we found impaired surface expression of S341P, L363P, and P372S mutants and reduced macroscopic currents for channels with the mutations S341P, G367V, and E376K. Calcium imaging and patch clamp experiments after incubation at 37°C revealed nonfunctional homo- and heteromeric channels in all five mutants, but incubation at 27°C combined with coexpression of the B3 subunit restored residual function of channels with the mutations S341P, G367V, and E376K. Hum Mutat 31:830,839, 2010. © 2010 Wiley-Liss, Inc. [source] The Militarization of Urban Marginality: Lessons from the Brazilian MetropolisINTERNATIONAL POLITICAL SOCIOLOGY, Issue 1 2008Loïc Wacquant This article examines the workings and effects of the penalization of poverty in urban Brazil at century's turn to uncover the deep logic of punitive containment as state strategy for the management of dispossessed and dishonored populations in the polarizing city in the age of triumphant neoliberalism. It shows how ramifying criminal violence (fed by extreme inequality and mass poverty), class and color discrimination in judicial processing, unchecked police brutality, and the catastrophic condition and chaotic operation of the carceral system combine to make the aggressive deployment of the penal apparatus in Brazil a surefire recipe for further disorder and disrespect for the law at the bottom of the urban hierarchy and steers the country into an institutional impasse. The policy of punitive containment pursued by political elites as a complement to the deregulation of the economy in the 1990s leads from the penalization to the militarization of urban marginality, under which residents of the declining favelas are treated as virtual enemies of the nation, tenuous trust in public institutions is undermined, and the spiral of violence accelerated. Brazil thus serves as a historical revelator of the full consequences of the penal disposal of the human detritus of a society swamped by social and physical insecurity. Drawing parallels between penal activity in the Brazilian and the U.S. metropolis further reveals that the neighborhoods of urban relegation wherein the marginal and stigmatized fractions of the postindustrial working class concentrate are the prime targets and proving ground upon which the neoliberal penal state is concretely being assembled, tried, and tested. Their study is therefore of urgent interest to analysts of international politics and state power at the dawn of the twenty-first century. [source] Effects of maternal occupational exposure to organic solvents on offspring visual functioning: A prospective controlled studyBIRTH DEFECTS RESEARCH, Issue 3 2001Christine Till Background Previous studies in adults and animals with high level exposure to organic solvents suggested impairments in visual functioning. The objective of this pilot study was to examine the effects of maternal occupational exposure to organic solvents during pregnancy on offspring color vision and visual acuity, the development of which may be especially vulnerable to organic solvent exposure. Methods We conducted a prospective cohort study of 32 offspring of women who were exposed occupationally to organic solvents during pregnancy compared with 27 nonexposed children. Monocular and binocular color vision and visual acuity were assessed using the Minimalist Test and the Cardiff Cards, respectively. Children with known hereditary color vision loss were excluded. Results Solvent-exposed children had significantly higher error scores on red-green and blue-yellow color discrimination, as well as poorer visual acuity compared with the control group. Exposure index (an estimated measure of exposure intensity) was not significantly related to color discrimination or visual acuity score. Despite excluding all children with a known family history of color vision loss, clinical red-green color vision loss was found among 3 of the 32 exposed children compared with none of the matched controls. Conclusions These preliminary findings suggest that occupational exposure to organic solvents during pregnancy is associated with an increased risk of color vision and visual acuity impairment in offspring. The importance of routine visual function screening in risk assessment after prenatal exposure to chemicals warrants further attention. Teratology 64:134,141, 2001. © 2001 Wiley-Liss, Inc. [source] Measurement of memory of colorCOLOR RESEARCH & APPLICATION, Issue 4 2002H. H. Seliger Abstract Colors produced by monochromatic wavelengths of light viewed in isolation have been used as the only visual variables in short-term delayed matching (DM) and long-term recall (LTR) protocols to quantify three types of color memory in individuals with normal color vision. Measurements were normally distributed, so that color memories of individuals could be compared in terms of means and standard deviations. The variance of LTR of colors of familiar objects is shown to be separable into two portions, one due to "preferred colors" and the other due to individuals' precisions of matching. The wavelength dependence of DM exhibited minima of standard deviations at the same wavelengths as those reported for color discrimination measured by bipartite wavelength matching, and these wavelengths were shown to occur at the wavelengths of the intersections of cone spectral sensitivities. In an intermediate "green" region of relatively constant color discrimination, it was possible to combine DM measurements for different wavelengths for statistical analysis. The standard deviations of DM for individuals of a healthy population were normally distributed, providing a 95% upper confidence limit for identifying individuals with possible short-term memory impairment. Preliminary measurements of standard deviations of DM for delay times of , 1 s were consistent with a proposed rapidly decaying color imagery memory. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 233,242, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10067 [source] | ||||||||||