Spectral tuning of pigments underlying red-green color vision

Variations in the absorption spectra of cone photopigments over the spectral range of about 530 to 562 nanometers are a principal cause of individual differences in human color vision and of differences in color vision within and across other primates. To study the molecular basis of these variations, nucleotide sequences were determined for eight primate photopigment genes. The spectral peaks of the pigments specified by these genes spanned the range from 530 to 562 nanometers. Comparisons of the deduced amino acid sequences of these eight pigments suggest that three amino acid substitutions produce the approximately 30-nanometer difference in spectral peaks of the pigments underlying human red-green color vision, and red shifts of specific magnitudes are produced by replacement of nonpolar with hydroxyl-bearing amino acids at each of the three critical positions.     

彩色多普勒能量图与彩色多普勒血流图诊断肝血管瘤效果的比较

目的 :比较彩色多普勒能量图 (CDE)与彩色多普勒血流图 (CDFI)诊断肝血管瘤的效果。方法 :用 CDE与CDFI观察 2 8例 (36个 )肝血管瘤内的血流情况 ,比较两者的血流显示率。结果 :CDE和 CDFI对肝血管瘤内血流的显示率分别为 94.4%和 2 8.9% ,两者差异有非常显著性 (P<0 .0 1)。结论 :CDE对肝血管瘤的敏感性明显高于 CDFI,表明CDE对肝血管瘤的诊断及鉴别诊断有较大的应用价值。     

彩叶植物叶色表达机制研究进展

彩叶植物因其独特的叶色表达近年来在园林绿化中备受关注,应用越来越广泛.综述了国内外影响彩叶植物叶色表达的主要物质花青苷及其合成相关酶、生理生化及分子机制方面的研究进展,以期为园林树种叶色改良和育种提供理论依据.     

Ultraviolet reflection of a male butterfly: interference color caused by thin-layer elaboration of wing scales

Males of the butterfly Eurema lisa, like many other members of the family Pieridae, reflect ultraviolet light. The color is structural rather than pigmentary, and originates from optical interference in a microscopic lamellar system associated with ridges on the outer scales of the wing. The dimensions and angular orientation of the lamellar system conform to predictions based on physical measurement of the spectral characteristics, including "color shifts" with varying angles of incidence, of the reflected ultraviolet light. The female lacks such scales and is consequently nonreflectant. The ultraviolet dimorphism supposedly serves as the basis for sexual recognition in courtship.     

The developmental role of Agouti in color pattern evolution

Animal color patterns can affect fitness in the wild; however, little is known about the mechanisms that control their formation and subsequent evolution. We took advantage of two locally camouflaged populations of Peromyscus mice to show that the negative regulator of adult pigmentation, Agouti, also plays a key developmental role in color pattern evolution. Genetic and functional analyses showed that ventral-specific embryonic expression of Agouti establishes a prepattern by delaying the terminal differentiation of ventral melanocytes. Moreover, a skin-specific increase in both the level and spatial domain of Agouti expression prevents melanocyte maturation in a regionalized manner, resulting in a novel and adaptive color pattern. Thus, natural selection favors late-acting, tissue-specific changes in embryonic Agouti expression to produce large changes in adult color pattern.     

Compound eyes: localization of two color receptors in the same ommatidium

The compound eye of the cockroach Periplaneta has receptors for ultraviolet light (maximum sensitivity at 365 nanometers) and green light (maximum sensitivity at 510 nanometers). Single photoreceptor cells in the compound eye were impaled, identified by spectral response, and marked with dye-filled microelectrodes. Using two diferent dyes, we showed that both types of receptors can be found in the same ommatidium.     

彩叶植物叶色变化及相关影响因子研究进展

彩叶植物的叶色表达受遗传因素和外部环境因子共同影响。文章从基因和遗传、彩叶形成中叶片生理生化变化、影响彩叶形成的生态因子、叶片结构及其他相关影响因子等几方面论述了国内外有关彩叶植物叶色表达的研究概况,并对彩叶植物今后的研究方向提出了展望,以期为彩叶植物叶色改良和新品种选育提供理论依据。     

Opponent color cells in the cat lateral geniculate nucleus

A microelectrode survey of the cat lateral geniculate has uncovered an infrequent new type of lateral geniculate cell in layer B with "on" center responses to short wavelengths and "off" center responses to long wavelengths. The short wavelength responses are mediated by cones with peak sensitivity at about 450 nanometers, and the long wavelength responses by cones with peak sensitivity at 556 nanometers. Two of double opponent color cells also had double opponent features.     

基于ISSR标记的不同体色瓯江彩鲤种质鉴定

应用ISSR分子标记技术对5种体色瓯江彩鲤(Cyprinus carpio var.color)("全红"、"粉玉"、"粉花"、"麻花"和"大花")进行遗传多样性分析,筛选出的14条引物在5种体色瓯江彩鲤中共检测到125个位点,多态位点比率达68%,有效等位基因数为1.479 3,期望杂合度为0.273 9,Shannon多样性指数为0.401 0;5种不同体色瓯江彩鲤间的平均遗传距离为0.342 4,NJ法和UPMGA法对它们进行聚类分析显示"粉玉"、"粉花"和"全红"为一支,"麻花"和"大花"为另一支。应用引物848扩增的3个多态性位点构建了这5种不同体色瓯江彩鲤的DNA指纹图谱,可为不同体色瓯江彩鲤种质鉴定提供快捷、准确的鉴定结果。     

Prolonged color blindness induced by intense spectral lights in rhesus monkeys

Prolonged exposure of rhesus monkeys to intense blue light produces long-term changes which are consistent with loss of response of those cones that contain a photopigment with peak absorption at 445 nanometers. The 90 percent reduction of spectral sensitivity in the blue region has lasted more than 5 months. Reduced sensitivity to long wavelengths is produced by adaptation to light of 520 nanometers. This reduced sensitivity, which lasts no more than 30 days, is attributed to a temporary loss of response of the cones containing a photopigment with peak absorption at 535 nanometers.     

Contours and contrast: responses of monkey lateral geniculate nucleus cells to luminance and color figures

The responses of single units in the monkey lateral geniculate nucleus to different portions of figures which differed from their backgrounds in color and brightness were examined. Border enhancement was found in the response to luminance figures but not in the response to color figures. In addition, cells showed border enhancement only in the case of a figure which produced an increment (as opposed to a decrement) in their firing rates. In situations in which very striking brightness contrast is seen perceptually, the cells do not show the corresponding changes in firing rate across the whole pattern. The lateral inhibitory mechanisms found in the retina and geniculate can thus account for luminance border enhancement, but not entirely for simultaneous brightness or color contrast, for which other cortical processes of some sort must be responsible.     

瓯江彩鲤体色与生长的遗传-环境互作分析

对五种体色的瓯江彩鲤进行稻田、网箱和水泥池生长对比试验,探讨体色与生长的遗传-环境互作。结果表明:瓯江彩鲤的体色与生长率存在一定程度的互作效应,在稻田中,“全红”和“麻花”彩鲤的生长率显著地高于其它三种体色(P<0.05);在网箱中,“大花”、“粉玉”和“粉花”彩鲤的生长率显著地高于“全红”和“麻花”彩鲤(P<0.05);在池塘中,“大花”彩鲤的生长率极显著高于其它四种体色彩鲤(P<0.01),而其它四种体色彩鲤的生长性能不存在显著差异(P>0.05)。由此认为,“全红”和“麻花”彩鲤比较适合稻田饲养,“大花”、“粉玉”和“粉花”彩鲤比较适合网箱或池塘饲养。“粉花”彩鲤与环境的互作效应最大。     

瓯江彩鲤体色与生长的遗传-环境互作分析

对五种体色的瓯江彩鲤进行稻田、网箱和水泥池生长对比试验,探讨体色与生长的遗传-环境互作。结果表明:瓯江彩鲤的体色与生长率存在一定程度的互作效应,在稻田中,“全红”和“麻花”彩鲤的生长率显著地高于其它三种体色(P<0.05);在网箱中,“大花”、“粉玉”和“粉花”彩鲤的生长率显著地高于“全红”和“麻花”彩鲤(P<0.05);在池塘中,“大花”彩鲤的生长率极显著高于其它四种体色彩鲤(P<0.01),而其它四种体色彩鲤的生长性能不存在显著差异(P>0.05)。由此认为,“全红”和“麻花”彩鲤比较适合稻田饲养,“大花”、“粉玉”和“粉花”彩鲤比较适合网箱或池塘饲养。“粉花”彩鲤与环境的互作效应最大。     

天蚕不同蛾色产卵与幼虫体色的调查

对不同蛾色分离、产卵数量、幼虫体色、茧色和茧质调查结果表明：蛾色不同其造卵数和产卵数有差异,产卵数量最高的是黄色蛾早×黄色蛾6组合,平均为260粒,产卵净度达86．5％。浅灰色、黑色和暗黑色产卵量较低;幼虫体色可分为浅黄色和绿色2个类型,幼虫体色不同,其茧色也有差异,可分为黄色、浅黄色、浅绿色和绿色;不同茧色的茧层率差异不显著,雄茧高于雌茧的茧层率1％左右。     

A single amino acid mutation contributes to adaptive beach mouse color pattern

Natural populations of beach mice exhibit a characteristic color pattern, relative to their mainland conspecifics, driven by natural selection for crypsis. We identified a derived, charge-changing amino acid mutation in the melanocortin-1 receptor (Mc1r) in beach mice, which decreases receptor function. In genetic crosses, allelic variation at Mc1r explains 9.8% to 36.4% of the variation in seven pigmentation traits determining color pattern. The derived Mc1r allele is present in Florida's Gulf Coast beach mice but not in Atlantic coast mice with similar light coloration, suggesting that different molecular mechanisms are responsible for convergent phenotypic evolution. Here, we link a single mutation in the coding region of a pigmentation gene to adaptive quantitative variation in the wild.     

彩色多普勒超声对乳腺肿瘤的诊断价值

目的探讨彩色多普勒超声对乳腺肿瘤的诊断价值。方法选取经术后病理证实的乳腺癌119例,乳腺良性肿瘤47例,分析其声像图特征。结果超声诊断乳腺癌111例,误诊8例,良性肿瘤44例,误诊3例。超声诊断乳腺癌的准确性、特异性及敏感性分别为93．4％、84．6％及97．4％,阳性预测值和阴性预测值分别为93．3％和93．6％。边缘毛刺、纵／横比≥1、后方回声衰减、沙砾样钙化、RI等指标在鉴别乳腺良恶性肿瘤中差异有统计学意义（P〈0．01）。结论高频彩色多普勒超声对乳腺癌的鉴别诊断有重要价值。     

Segregation of form, color, movement, and depth: anatomy, physiology, and perception

Anatomical and physiological observations in monkeys indicate that the primate visual system consists of several separate and independent subdivisions that analyze different aspects of the same retinal image: cells in cortical visual areas 1 and 2 and higher visual areas are segregated into three interdigitating subdivisions that differ in their selectivity for color, stereopsis, movement, and orientation. The pathways selective for form and color seem to be derived mainly from the parvocellular geniculate subdivisions, the depth- and movement-selective components from the magnocellular. At lower levels, in the retina and in the geniculate, cells in these two subdivisions differ in their color selectivity, contrast sensitivity, temporal properties, and spatial resolution. These major differences in the properties of cells at lower levels in each of the subdivisions led to the prediction that different visual functions, such as color, depth, movement, and form perception, should exhibit corresponding differences. Human perceptual experiments are remarkably consistent with these predictions. Moreover, perceptual experiments can be designed to ask which subdivisions of the system are responsible for particular visual abilities, such as figure/ground discrimination or perception of depth from perspective or relative movement--functions that might be difficult to deduce from single-cell response properties.     

Attentional modulation of neural processing of shape, color, and velocity in humans

Positron emission tomography (PET) was used to measure changes in regional cerebral blood flow of normal subjects, while they were discriminating different attributes (shape, color, and velocity) of the same set of visual stimuli. Psychophysical evidence indicated that the sensitivity for discriminating subtle stimulus changes was higher when subjects focused attention on one attribute than when they divided attention among several attributes. Correspondingly, attention enhanced the activity of different regions of extrastriate visual cortex that appear to be specialized for processing information related to the selected attribute.     

彩色多普勒超声对乳腺癌腋窝淋巴结转移的诊断价值

目的:评价彩色多普勒超声与临床触诊诊断乳腺癌腋窝淋巴结转移的灵敏度、特异度和准确度性。方法:应用双盲法对53例(55侧)行乳腺癌根治术患者的术前触诊、超声检查及术后病理检查进行对比分析。结果:55侧中,病理证实41侧有淋巴结转移,临床触诊和超声检出侧分别为35侧和39侧,触诊的灵敏度、特异度、诊断符合率分别为68.3%、50.0%、63.6%,超声则分别为87.8%、78.6%、85.5%,两组间的灵敏度及诊断符合率差异有统计学意义(P<0.05或<0.01),特异度则差异无统计学意义(P>0.05)。结论:超声检查腋窝淋巴结的灵敏度及诊断符合率均高于触诊,可作为诊断淋巴结转移的常规检查项目。     

英国皇家园艺学会比色卡颜色特征及其在盆栽香石竹花色测定上的应用

为明确植物常用颜色测定工具英国皇家园艺学会比色卡(Royal Horticultural Society Color Chart，RHSCC)的颜色特征及其在花色测定应用上的科学性，以884个RHSCC色号和150个盆栽香石竹品种花色为研究对象，采用色差仪测定法和色卡目测比对法进行颜色测定，利用统计学方法和色差公式进行颜色分析。结果表明:RHSCC 884个色号在高明度、红色及黄色分量区分布密集；在a^*b^*二维分布上集中于第I和第II象限；60个色号两两间最小色差值为0.50~1.50，其中4个色号处于不同UPOV(国际植物新品种保护联盟)色组。RHSCC目测法结果显示，150个盆栽香石竹品种中，47个品种花色难以比对到准确的RHSCC色号(花色及其近似色卡色差值>6.00)；部分品种花色可比对到2个RHSCC色号(色卡间色差值<3.00)。RHSCC目测法对品种分组的结果表明，粉色系颜色区间过大，白色和深紫色系区间过小；黄绿色、黄色和绿色3个色系难以在颜色阈值上区分；多数色系含有游离颜色等问题。综上，RHSCC在花色测定时需要考虑其局限性，包括部分色号间色差值过小，人眼分辨困难；部分颜色未覆盖，导致观测结果不准确；比对结果难以有效用于品种分组等。