Improved color constancy in honey bees enabled by parallel visual projections from dorsal ocelli.

PubMed

Garcia, Jair E; Hung, Yu-Shan; Greentree, Andrew D; Rosa, Marcello G P; Endler, John A; Dyer, Adrian G

2017-07-18

How can a pollinator, like the honey bee, perceive the same colors on visited flowers, despite continuous and rapid changes in ambient illumination and background color? A hundred years ago, von Kries proposed an elegant solution to this problem, color constancy, which is currently incorporated in many imaging and technological applications. However, empirical evidence on how this method can operate on animal brains remains tenuous. Our mathematical modeling proposes that the observed spectral tuning of simple ocellar photoreceptors in the honey bee allows for the necessary input for an optimal color constancy solution to most natural light environments. The model is fully supported by our detailed description of a neural pathway allowing for the integration of signals originating from the ocellar photoreceptors to the information processing regions in the bee brain. These findings reveal a neural implementation to the classic color constancy problem that can be easily translated into artificial color imaging systems.

Working Memory Is Related to Perceptual Processing: A Case from Color Perception

ERIC Educational Resources Information Center

Allen, Elizabeth C.; Beilock, Sian L.; Shevell, Steven K.

2011-01-01

We explored the relation between individual differences in working memory (WM) and color constancy, the phenomenon of color perception that allows us to perceive the color of an object as relatively stable under changes in illumination. Successive color constancy (measured by first viewing a colored surface under a particular illumination and…

Experience-Dependent Color Constancy in Guppies (Poecilia reticulata)

PubMed Central

Intskirveli, I. E.; Roinishvili, M. O.; Kezeli, A. R.

2002-01-01

We investigated the ability to recognize the color of surfaces in fish (Poecilia reticulata), bred from birth in conditions of artificial light with constant spectral content. The capacity for color constancy significantly deteriorated when compared that to the control group. Further alteration of lighting conditions and transfer into natural daylight conditions restored the suppressed function to its normal level. We suggest that the color constancy function belongs in the visual system-response functions, the full development of which requires the accumulation of individual visual experience. PMID:12757371

Experience-dependent color constancy in guppies (Poecilia reticulata).

PubMed

Intskirveli, I E; Roinishvili, M O; Kezeli, A R

2002-01-01

We investigated the ability to recognize the color of surfaces in fish (Poecilia reticulata), bred from birth in conditions of artificial light with constant spectral content. The capacity for color constancy significantly deteriorated when compared that to the control group. Further alteration of lighting conditions and transfer into natural daylight conditions restored the suppressed function to its normal level. We suggest that the color constancy function belongs in the visual system-response functions, the full development of which requires the accumulation of individual visual experience.

Lightness Constancy in Surface Visualization

PubMed Central

Szafir, Danielle Albers; Sarikaya, Alper; Gleicher, Michael

2016-01-01

Color is a common channel for displaying data in surface visualization, but is affected by the shadows and shading used to convey surface depth and shape. Understanding encoded data in the context of surface structure is critical for effective analysis in a variety of domains, such as in molecular biology. In the physical world, lightness constancy allows people to accurately perceive shadowed colors; however, its effectiveness in complex synthetic environments such as surface visualizations is not well understood. We report a series of crowdsourced and laboratory studies that confirm the existence of lightness constancy effects for molecular surface visualizations using ambient occlusion. We provide empirical evidence of how common visualization design decisions can impact viewers’ abilities to accurately identify encoded surface colors. These findings suggest that lightness constancy aids in understanding color encodings in surface visualization and reveal a correlation between visualization techniques that improve color interpretation in shadow and those that enhance perceptions of surface depth. These results collectively suggest that understanding constancy in practice can inform effective visualization design. PMID:26584495

Illuminant color estimation based on pigmentation separation from human skin color

NASA Astrophysics Data System (ADS)

Tanaka, Satomi; Kakinuma, Akihiro; Kamijo, Naohiro; Takahashi, Hiroshi; Tsumura, Norimichi

2015-03-01

Human has the visual system called "color constancy" that maintains the perceptive colors of same object across various light sources. The effective method of color constancy algorithm was proposed to use the human facial color in a digital color image, however, this method has wrong estimation results by the difference of individual facial colors. In this paper, we present the novel color constancy algorithm based on skin color analysis. The skin color analysis is the method to separate the skin color into the components of melanin, hemoglobin and shading. We use the stationary property of Japanese facial color, and this property is calculated from the components of melanin and hemoglobin. As a result, we achieve to propose the method to use subject's facial color in image and not depend on the individual difference among Japanese facial color.

Color constancy by characterization of illumination chromaticity

NASA Astrophysics Data System (ADS)

Nikkanen, Jarno T.

2011-05-01

Computational color constancy algorithms play a key role in achieving desired color reproduction in digital cameras. Failure to estimate illumination chromaticity correctly will result in invalid overall colour cast in the image that will be easily detected by human observers. A new algorithm is presented for computational color constancy. Low computational complexity and low memory requirement make the algorithm suitable for resource-limited camera devices, such as consumer digital cameras and camera phones. Operation of the algorithm relies on characterization of the range of possible illumination chromaticities in terms of camera sensor response. The fact that only illumination chromaticity is characterized instead of the full color gamut, for example, increases robustness against variations in sensor characteristics and against failure of diagonal model of illumination change. Multiple databases are used in order to demonstrate the good performance of the algorithm in comparison to the state-of-the-art color constancy algorithms.

Categorical color constancy for simulated surfaces.

PubMed

Olkkonen, Maria; Hansen, Thorsten; Gegenfurtner, Karl R

2009-11-12

Color constancy is the ability to perceive constant surface colors under varying lighting conditions. Color constancy has traditionally been investigated with asymmetric matching, where stimuli are matched over two different contexts, or with achromatic settings, where a stimulus is made to appear gray. These methods deliver accurate information on the transformations of single points of color space under illuminant changes, but can be cumbersome and unintuitive for observers. Color naming is a fast and intuitive alternative to matching, allowing data collection from a large portion of color space. We asked observers to name the colors of 469 Munsell surfaces with known reflectance spectra simulated under five different illuminants. Observers were generally as consistent in naming the colors of surfaces under different illuminants as they were naming the colors of the same surfaces over time. The transformations in category boundaries caused by illuminant changes were generally small and could be explained well with simple linear models. Finally, an analysis of the pattern of naming consistency across color space revealed that largely the same hues were named consistently across illuminants and across observers even after correcting for category size effects. This indicates a possible relationship between perceptual color constancy and the ability to consistently communicate colors.

Color constancy: phenomenal or projective?

PubMed

Reeves, Adam J; Amano, Kinjiro; Foster, David H

2008-02-01

Naive observers viewed a sequence of colored Mondrian patterns, simulated on a color monitor. Each pattern was presented twice in succession, first under one daylight illuminant with a correlated color temperature of either 16,000 or 4000 K and then under the other, to test for color constancy. The observers compared the central square of the pattern across illuminants, either rating it for sameness of material appearance or sameness of hue and saturation or judging an objective property-that is, whether its change of color originated from a change in material or only from a change in illumination. Average color constancy indices were high for material appearance ratings and binary judgments of origin and low for hue-saturation ratings. Individuals' performance varied, but judgments of material and of hue and saturation remained demarcated. Observers seem able to separate phenomenal percepts from their ontological projections of mental appearance onto physical phenomena; thus, even when a chromatic change alters perceived hue and saturation, observers can reliably infer the cause, the constancy of the underlying surface spectral reflectance.

No Measured Effect of a Familiar Contextual Object on Color Constancy.

PubMed

Kanematsu, Erika; Brainard, David H

2014-08-01

Some familiar objects have a typical color, such as the yellow of a banana. The presence of such objects in a scene is a potential cue to the scene illumination, since the light reflected from them should on average be consistent with their typical surface reflectance. Although there are many studies on how the identity of an object affects how its color is perceived, little is known about whether the presence of a familiar object in a scene helps the visual system stabilize the color appearance of other objects with respect to changes in illumination. We used a successive color matching procedure in three experiments designed to address this question. Across the experiments we studied a total of 6 subjects (2 in Experiment 1, 3 in Experiment 2, and 4 in Experiment 3) with partial overlap of subjects between experiments. We compared measured color constancy across conditions in which a familiar object cue to the illuminant was available with conditions in which such a cue was not present. Overall, our results do not reveal a reliable improvement in color constancy with the addition of a familiar object to a scene. An analysis of the experimental power of our data suggests that if there is such an effect, it is small: less than approximately a change of 0.09 in a constancy index where an absence of constancy corresponds to an index value of 0 and perfect constancy corresponds to an index value of 1.

No Measured Effect of a Familiar Contextual Object on Color Constancy

PubMed Central

Kanematsu, Erika; Brainard, David H.

2013-01-01

Some familiar objects have a typical color, such as the yellow of a banana. The presence of such objects in a scene is a potential cue to the scene illumination, since the light reflected from them should on average be consistent with their typical surface reflectance. Although there are many studies on how the identity of an object affects how its color is perceived, little is known about whether the presence of a familiar object in a scene helps the visual system stabilize the color appearance of other objects with respect to changes in illumination. We used a successive color matching procedure in three experiments designed to address this question. Across the experiments we studied a total of 6 subjects (2 in Experiment 1, 3 in Experiment 2, and 4 in Experiment 3) with partial overlap of subjects between experiments. We compared measured color constancy across conditions in which a familiar object cue to the illuminant was available with conditions in which such a cue was not present. Overall, our results do not reveal a reliable improvement in color constancy with the addition of a familiar object to a scene. An analysis of the experimental power of our data suggests that if there is such an effect, it is small: less than approximately a change of 0.09 in a constancy index where an absence of constancy corresponds to an index value of 0 and perfect constancy corresponds to an index value of 1. PMID:25313267

HDR imaging and color constancy: two sides of the same coin?

NASA Astrophysics Data System (ADS)

McCann, John J.

2011-01-01

At first, we think that High Dynamic Range (HDR) imaging is a technique for improved recordings of scene radiances. Many of us think that human color constancy is a variation of a camera's automatic white balance algorithm. However, on closer inspection, glare limits the range of light we can detect in cameras and on retinas. All scene regions below middle gray are influenced, more or less, by the glare from the bright scene segments. Instead of accurate radiance reproduction, HDR imaging works well because it preserves the details in the scene's spatial contrast. Similarly, on closer inspection, human color constancy depends on spatial comparisons that synthesize appearances from all the scene segments. Can spatial image processing play similar principle roles in both HDR imaging and color constancy?

Retinex Image Processing: Improved Fidelity To Direct Visual Observation

NASA Technical Reports Server (NTRS)

Jobson, Daniel J.; Rahman, Zia-Ur; Woodell, Glenn A.

1996-01-01

Recorded color images differ from direct human viewing by the lack of dynamic range compression and color constancy. Research is summarized which develops the center/surround retinex concept originated by Edwin Land through a single scale design to a multi-scale design with color restoration (MSRCR). The MSRCR synthesizes dynamic range compression, color constancy, and color rendition and, thereby, approaches fidelity to direct observation.

Color constancy in 3D-2D face recognition

NASA Astrophysics Data System (ADS)

Meyer, Manuel; Riess, Christian; Angelopoulou, Elli; Evangelopoulos, Georgios; Kakadiaris, Ioannis A.

2013-05-01

Face is one of the most popular biometric modalities. However, up to now, color is rarely actively used in face recognition. Yet, it is well-known that when a person recognizes a face, color cues can become as important as shape, especially when combined with the ability of people to identify the color of objects independent of illuminant color variations. In this paper, we examine the feasibility and effect of explicitly embedding illuminant color information in face recognition systems. We empirically examine the theoretical maximum gain of including known illuminant color to a 3D-2D face recognition system. We also investigate the impact of using computational color constancy methods for estimating the illuminant color, which is then incorporated into the face recognition framework. Our experiments show that under close-to-ideal illumination estimates, one can improve face recognition rates by 16%. When the illuminant color is algorithmically estimated, the improvement is approximately 5%. These results suggest that color constancy has a positive impact on face recognition, but the accuracy of the illuminant color estimate has a considerable effect on its benefits.

White constancy method for mobile displays

NASA Astrophysics Data System (ADS)

Yum, Ji Young; Park, Hyun Hee; Jang, Seul Ki; Lee, Jae Hyang; Kim, Jong Ho; Yi, Ji Young; Lee, Min Woo

2014-03-01

In these days, consumer's needs for image quality of mobile devices are increasing as smartphone is widely used. For example, colors may be perceived differently when displayed contents under different illuminants. Displayed white in incandescent lamp is perceived as bluish, while same content in LED light is perceived as yellowish. When changed in perceived white under illuminant environment, image quality would be degraded. Objective of the proposed white constancy method is restricted to maintain consistent output colors regardless of the illuminants utilized. Human visual experiments are performed to analyze viewers'perceptual constancy. Participants are asked to choose the displayed white in a variety of illuminants. Relationship between the illuminants and the selected colors with white are modeled by mapping function based on the results of human visual experiments. White constancy values for image control are determined on the predesigned functions. Experimental results indicate that propsed method yields better image quality by keeping the display white.

Color constancy in dermatoscopy with smartphone

NASA Astrophysics Data System (ADS)

Cugmas, Blaž; Pernuš, Franjo; Likar, Boštjan

2017-12-01

The recent spread of cheap dermatoscopes for smartphones can empower patients to acquire images of skin lesions on their own and send them to dermatologists. Since images are acquired by different smartphone cameras under unique illumination conditions, the variability in colors is expected. Therefore, the mobile dermatoscopic systems should be calibrated in order to ensure the color constancy in skin images. In this study, we have tested a dermatoscope DermLite DL1 basic, attached to Samsung Galaxy S4 smartphone. Under the controlled conditions, jpeg images of standard color patches were acquired and a model between an unknown device-dependent RGB and a deviceindependent Lab color space has been built. Results showed that median and the best color error was 7.77 and 3.94, respectively. Results are in the range of a human eye detection capability (color error ≈ 4) and video and printing industry standards (color error is expected to be between 5 and 6). It can be concluded that a calibrated smartphone dermatoscope can provide sufficient color constancy and can serve as an interesting opportunity to bring dermatologists closer to the patients.

What #theDress reveals about the role of illumination priors in color perception and color constancy

PubMed Central

Aston, Stacey; Hurlbert, Anya

2018-01-01

The disagreement between people who named #theDress (the Internet phenomenon of 2015) “blue and black” versus “white and gold” is thought to be caused by individual differences in color constancy. It is hypothesized that observers infer different incident illuminations, relying on illumination “priors” to overcome the ambiguity of the image. Different experiences may drive the formation of different illumination priors, and these may be indicated by differences in chronotype. We assess this hypothesis, asking whether matches to perceived illumination in the image and/or perceived dress colors relate to scores on the morningness-eveningness questionnaire (a measure of chronotype). We find moderate correlations between chronotype and illumination matches (morning types giving bluer illumination matches than evening types) and chronotype and dress body matches, but these are significant only at the 10% level. Further, although inferred illumination chromaticity in the image explains variation in the color matches to the dress (confirming the color constancy hypothesis), color constancy thresholds obtained using an established illumination discrimination task are not related to dress color perception. We also find achromatic settings depend on luminance, suggesting that subjective white point differences may explain the variation in dress color perception only if settings are made at individually tailored luminance levels. The results of such achromatic settings are inconsistent with their assumed correspondence to perceived illumination. Finally, our results suggest that perception and naming are disconnected, with observers reporting different color names for the dress photograph and their isolated color matches, the latter best capturing the variation in the matches. PMID:28793353

Low levels of specularity support operational color constancy, particularly when surface and illumination geometry can be inferred

PubMed Central

Lee, Robert J.; Smithson, Hannah E.

2016-01-01

We tested whether surface specularity alone supports operational color constancy – the ability to discriminate changes in illumination or reflectance. Observers viewed short animations of illuminant or reflectance changes in rendered scenes containing a single spherical surface, and were asked to classify the change. Performance improved with increasing specularity, as predicted from regularities in chromatic statistics. Peak performance was impaired by spatial rearrangements of image pixels that disrupted the perception of illuminated surfaces, but was maintained with increased surface complexity. The characteristic chromatic transformations that are available with non-zero specularity are useful for operational color constancy, particularly if accompanied by appropriate perceptual organisation. PMID:26974938

Color constancy: enhancing von Kries adaption via sensor transformations

NASA Astrophysics Data System (ADS)

Finlayson, Graham D.; Drew, Mark S.; Funt, Brian V.

1993-09-01

Von Kries adaptation has long been considered a reasonable vehicle for color constancy. Since the color constancy performance attainable via the von Kries rule strongly depends on the spectral response characteristics of the human cones, we consider the possibility of enhancing von Kries performance by constructing new `sensors' as linear combinations of the fixed cone sensitivity functions. We show that if surface reflectances are well-modeled by 3 basis functions and illuminants by 2 basis functions then there exists a set of new sensors for which von Kries adaptation can yield perfect color constancy. These new sensors can (like the cones) be described as long-, medium-, and short-wave sensitive; however, both the new long- and medium-wave sensors have sharpened sensitivities -- their support is more concentrated. The new short-wave sensor remains relatively unchanged. A similar sharpening of cone sensitivities has previously been observed in test and field spectral sensitivities measured for the human eye. We present simulation results demonstrating improved von Kries performance using the new sensors even when the restrictions on the illumination and reflectance are relaxed.

How temporal cues can aid colour constancy

PubMed Central

Foster, David H.; Amano, Kinjiro; Nascimento, Sérgio M. C.

2007-01-01

Colour constancy assessed by asymmetric simultaneous colour matching usually reveals limited levels of performance in the unadapted eye. Yet observers can readily discriminate illuminant changes on a scene from changes in the spectral reflectances of the surfaces making up the scene. This ability is probably based on judgements of relational colour constancy, in turn based on the physical stability of spatial ratios of cone excitations under illuminant changes. Evidence is presented suggesting that the ability to detect violations in relational colour constancy depends on temporal transient cues. Because colour constancy and relational colour constancy are closely connected, it should be possible to improve estimates of colour constancy by introducing similar transient cues into the matching task. To test this hypothesis, an experiment was performed in which observers made surface-colour matches between patterns presented in the same position in an alternating sequence with period 2 s or, as a control, presented simultaneously, side-by-side. The degree of constancy was significantly higher for sequential presentation, reaching 87% for matches averaged over 20 observers. Temporal cues may offer a useful source of information for making colour-constancy judgements. PMID:17515948

Investigation of Color Constancy in 4.5-Month-Old Infants under a Strict Control of Luminance Contrast for Individual Participants

ERIC Educational Resources Information Center

Yang, Jiale; Kanazawa, So; Yamaguchi, Masami K.; Kuriki, Ichiro

2013-01-01

The current study examined color constancy in infants using a familiarization paradigm. We first obtained isoluminance in each infant as defined by the minimum motion paradigm and used these data to control the luminance of stimuli in the main experiments. In the familiarization phase of the main experiment, two identical smiling face patterns…

Information-Adaptive Image Encoding and Restoration

NASA Technical Reports Server (NTRS)

Park, Stephen K.; Rahman, Zia-ur

1998-01-01

The multiscale retinex with color restoration (MSRCR) has shown itself to be a very versatile automatic image enhancement algorithm that simultaneously provides dynamic range compression, color constancy, and color rendition. A number of algorithms exist that provide one or more of these features, but not all. In this paper we compare the performance of the MSRCR with techniques that are widely used for image enhancement. Specifically, we compare the MSRCR with color adjustment methods such as gamma correction and gain/offset application, histogram modification techniques such as histogram equalization and manual histogram adjustment, and other more powerful techniques such as homomorphic filtering and 'burning and dodging'. The comparison is carried out by testing the suite of image enhancement methods on a set of diverse images. We find that though some of these techniques work well for some of these images, only the MSRCR performs universally well oil the test set.

A Comparison of the Multiscale Retinex With Other Image Enhancement Techniques

NASA Technical Reports Server (NTRS)

Rahman, Zia-Ur; Woodell, Glenn A.; Jobson, Daniel J.

1997-01-01

The multiscale retinex with color restoration (MSRCR) has shown itself to be a very versatile automatic image enhancement algorithm that simultaneously provides dynamic range compression, color constancy, and color rendition. A number of algorithms exist that provide one or more of these features, but not all. In this paper we compare the performance of the MSRCR with techniques that are widely used for image enhancement. Specifically, we compare the MSRCR with color adjustment methods such as gamma correction and gain/offset application, histogram modification techniques such as histogram equalization and manual histogram adjustment, and other more powerful techniques such as homomorphic filtering and 'burning and dodging'. The comparison is carried out by testing the suite of image enhancement methods on a set of diverse images. We find that though some of these techniques work well for some of these images, only the MSRCR performs universally well on the test set.

Disparity, motion, and color information improve gloss constancy performance.

PubMed

Wendt, Gunnar; Faul, Franz; Ekroll, Vebjørn; Mausfeld, Rainer

2010-09-01

S. Nishida and M. Shinya (1998) found that observers have only a limited ability to recover surface-reflectance properties under changes in surface shape. Our aim in the present study was to investigate how the degree of surface-reflectance constancy depends on the availability of information that may help to infer the reflectance and shape properties of surfaces. To this end, we manipulated the availability of (i) motion-induced information (static vs. dynamic presentation), (ii) disparity information (with the levels "monocular," "surface disparity," and "surface + highlight disparity"), and (iii) color information (grayscale stimuli vs. hue differences between diffuse and specular reflections). The task of the subjects was to match the perceived lightness and glossiness between two surfaces with different spatial frequency and amplitude by manipulating the diffuse component and the exponent of the Phong lighting model in one of the surfaces. Our results indicate that all three types of information improve the constancy of glossiness matches--both in isolation and in combination. The lightness matching data only revealed an influence of motion and color information. Our results indicate, somewhat counterintuitively, that motion information has a detrimental effect on lightness constancy.

Color constancy using bright-neutral pixels

NASA Astrophysics Data System (ADS)

Wang, Yanfang; Luo, Yupin

2014-03-01

An effective illuminant-estimation approach for color constancy is proposed. Bright and near-neutral pixels are selected to jointly represent the illuminant color and utilized for illuminant estimation. To assess the representing capability of pixels, bright-neutral strength (BNS) is proposed by combining pixel chroma and brightness. Accordingly, a certain percentage of pixels with the largest BNS is selected to be the representative set. For every input image, a proper percentage value is determined via an iterative strategy by seeking the optimal color-corrected image. To compare various color-corrected images of an input image, image color-cast degree (ICCD) is devised using means and standard deviations of RGB channels. Experimental evaluation on standard real-world datasets validates the effectiveness of the proposed approach.

Spatial filtering, color constancy, and the color-changing dress.

PubMed

Dixon, Erica L; Shapiro, Arthur G

2017-03-01

The color-changing dress is a 2015 Internet phenomenon in which the colors in a picture of a dress are reported as blue-black by some observers and white-gold by others. The standard explanation is that observers make different inferences about the lighting (is the dress in shadow or bright yellow light?); based on these inferences, observers make a best guess about the reflectance of the dress. The assumption underlying this explanation is that reflectance is the key to color constancy because reflectance alone remains invariant under changes in lighting conditions. Here, we demonstrate an alternative type of invariance across illumination conditions: An object that appears to vary in color under blue, white, or yellow illumination does not change color in the high spatial frequency region. A first approximation to color constancy can therefore be accomplished by a high-pass filter that retains enough low spatial frequency content so as to not to completely desaturate the object. We demonstrate the implications of this idea on the Rubik's cube illusion; on a shirt placed under white, yellow, and blue illuminants; and on spatially filtered images of the dress. We hypothesize that observer perceptions of the dress's color vary because of individual differences in how the visual system extracts high and low spatial frequency color content from the environment, and we demonstrate cross-group differences in average sensitivity to low spatial frequency patterns.

Color constancy in natural scenes explained by global image statistics

PubMed Central

Foster, David H.; Amano, Kinjiro; Nascimento, Sérgio M. C.

2007-01-01

To what extent do observers' judgments of surface color with natural scenes depend on global image statistics? To address this question, a psychophysical experiment was performed in which images of natural scenes under two successive daylights were presented on a computer-controlled high-resolution color monitor. Observers reported whether there was a change in reflectance of a test surface in the scene. The scenes were obtained with a hyperspectral imaging system and included variously trees, shrubs, grasses, ferns, flowers, rocks, and buildings. Discrimination performance, quantified on a scale of 0 to 1 with a color-constancy index, varied from 0.69 to 0.97 over 21 scenes and two illuminant changes, from a correlated color temperature of 25,000 K to 6700 K and from 4000 K to 6700 K. The best account of these effects was provided by receptor-based rather than colorimetric properties of the images. Thus, in a linear regression, 43% of the variance in constancy index was explained by the log of the mean relative deviation in spatial cone-excitation ratios evaluated globally across the two images of a scene. A further 20% was explained by including the mean chroma of the first image and its difference from that of the second image and a further 7% by the mean difference in hue. Together, all four global color properties accounted for 70% of the variance and provided a good fit to the effects of scene and of illuminant change on color constancy, and, additionally, of changing test-surface position. By contrast, a spatial-frequency analysis of the images showed that the gradient of the luminance amplitude spectrum accounted for only 5% of the variance. PMID:16961965

Color constancy in natural scenes explained by global image statistics.

PubMed

Foster, David H; Amano, Kinjiro; Nascimento, Sérgio M C

2006-01-01

To what extent do observers' judgments of surface color with natural scenes depend on global image statistics? To address this question, a psychophysical experiment was performed in which images of natural scenes under two successive daylights were presented on a computer-controlled high-resolution color monitor. Observers reported whether there was a change in reflectance of a test surface in the scene. The scenes were obtained with a hyperspectral imaging system and included variously trees, shrubs, grasses, ferns, flowers, rocks, and buildings. Discrimination performance, quantified on a scale of 0 to 1 with a color-constancy index, varied from 0.69 to 0.97 over 21 scenes and two illuminant changes, from a correlated color temperature of 25,000 K to 6700 K and from 4000 K to 6700 K. The best account of these effects was provided by receptor-based rather than colorimetric properties of the images. Thus, in a linear regression, 43% of the variance in constancy index was explained by the log of the mean relative deviation in spatial cone-excitation ratios evaluated globally across the two images of a scene. A further 20% was explained by including the mean chroma of the first image and its difference from that of the second image and a further 7% by the mean difference in hue. Together, all four global color properties accounted for 70% of the variance and provided a good fit to the effects of scene and of illuminant change on color constancy, and, additionally, of changing test-surface position. By contrast, a spatial-frequency analysis of the images showed that the gradient of the luminance amplitude spectrum accounted for only 5% of the variance.

Perceptual approach for unsupervised digital color restoration of cinematographic archives

NASA Astrophysics Data System (ADS)

Chambah, Majed; Rizzi, Alessandro; Gatta, Carlo; Besserer, Bernard; Marini, Daniele

2003-01-01

The cinematographic archives represent an important part of our collective memory. We present in this paper some advances in automating the color fading restoration process, especially with regard to the automatic color correction technique. The proposed color correction method is based on the ACE model, an unsupervised color equalization algorithm based on a perceptual approach and inspired by some adaptation mechanisms of the human visual system, in particular lightness constancy and color constancy. There are some advantages in a perceptual approach: mainly its robustness and its local filtering properties, that lead to more effective results. The resulting technique, is not just an application of ACE on movie images, but an enhancement of ACE principles to meet the requirements in the digital film restoration field. The presented preliminary results are satisfying and promising.

Auditory color constancy: calibration to reliable spectral properties across nonspeech context and targets.

PubMed

Stilp, Christian E; Alexander, Joshua M; Kiefte, Michael; Kluender, Keith R

2010-02-01

Brief experience with reliable spectral characteristics of a listening context can markedly alter perception of subsequent speech sounds, and parallels have been drawn between auditory compensation for listening context and visual color constancy. In order to better evaluate such an analogy, the generality of acoustic context effects for sounds with spectral-temporal compositions distinct from speech was investigated. Listeners identified nonspeech sounds-extensively edited samples produced by a French horn and a tenor saxophone-following either resynthesized speech or a short passage of music. Preceding contexts were "colored" by spectral envelope difference filters, which were created to emphasize differences between French horn and saxophone spectra. Listeners were more likely to report hearing a saxophone when the stimulus followed a context filtered to emphasize spectral characteristics of the French horn, and vice versa. Despite clear changes in apparent acoustic source, the auditory system calibrated to relatively predictable spectral characteristics of filtered context, differentially affecting perception of subsequent target nonspeech sounds. This calibration to listening context and relative indifference to acoustic sources operates much like visual color constancy, for which reliable properties of the spectrum of illumination are factored out of perception of color.

Resiliency of the Multiscale Retinex Image Enhancement Algorithm

NASA Technical Reports Server (NTRS)

Rahman, Zia-Ur; Jobson, Daniel J.; Woodell, Glenn A.

1998-01-01

The multiscale retinex with color restoration (MSRCR) continues to prove itself in extensive testing to be very versatile automatic image enhancement algorithm that simultaneously provides dynamic range compression, color constancy, and color rendition, However, issues remain with regard to the resiliency of the MSRCR to different image sources and arbitrary image manipulations which may have been applied prior to retinex processing. In this paper we define these areas of concern, provide experimental results, and, examine the effects of commonly occurring image manipulation on retinex performance. In virtually all cases the MSRCR is highly resilient to the effects of both the image source variations and commonly encountered prior image-processing. Significant artifacts are primarily observed for the case of selective color channel clipping in large dark zones in a image. These issues are of concerning the processing of digital image archives and other applications where there is neither control over the image acquisition process, nor knowledge about any processing done on th data beforehand.

Surface-illuminant ambiguity and color constancy: effects of scene complexity and depth cues.

PubMed

Kraft, James M; Maloney, Shannon I; Brainard, David H

2002-01-01

Two experiments were conducted to study how scene complexity and cues to depth affect human color constancy. Specifically, two levels of scene complexity were compared. The low-complexity scene contained two walls with the same surface reflectance and a test patch which provided no information about the illuminant. In addition to the surfaces visible in the low-complexity scene, the high-complexity scene contained two rectangular solid objects and 24 paper samples with diverse surface reflectances. Observers viewed illuminated objects in an experimental chamber and adjusted the test patch until it appeared achromatic. Achromatic settings made tinder two different illuminants were used to compute an index that quantified the degree of constancy. Two experiments were conducted: one in which observers viewed the stimuli directly, and one in which they viewed the scenes through an optical system that reduced cues to depth. In each experiment, constancy was assessed for two conditions. In the valid-cue condition, many cues provided valid information about the illuminant change. In the invalid-cue condition, some image cues provided invalid information. Four broad conclusions are drawn from the data: (a) constancy is generally better in the valid-cue condition than in the invalid-cue condition: (b) for the stimulus configuration used, increasing image complexity has little effect in the valid-cue condition but leads to increased constancy in the invalid-cue condition; (c) for the stimulus configuration used, reducing cues to depth has little effect for either constancy condition: and (d) there is moderate individual variation in the degree of constancy exhibited, particularly in the degree to which the complexity manipulation affects performance.

[Research on developping the spectral dataset for Dunhuang typical colors based on color constancy].

PubMed

Liu, Qiang; Wan, Xiao-Xia; Liu, Zhen; Li, Chan; Liang, Jin-Xing

2013-11-01

The present paper aims at developping a method to reasonably set up the typical spectral color dataset for different kinds of Chinese cultural heritage in color rendering process. The world famous wall paintings dating from more than 1700 years ago in Dunhuang Mogao Grottoes was taken as typical case in this research. In order to maintain the color constancy during the color rendering workflow of Dunhuang culture relics, a chromatic adaptation based method for developping the spectral dataset of typical colors for those wall paintings was proposed from the view point of human vision perception ability. Under the help and guidance of researchers in the art-research institution and protection-research institution of Dunhuang Academy and according to the existing research achievement of Dunhuang Research in the past years, 48 typical known Dunhuang pigments were chosen and 240 representative color samples were made with reflective spectral ranging from 360 to 750 nm was acquired by a spectrometer. In order to find the typical colors of the above mentioned color samples, the original dataset was devided into several subgroups by clustering analysis. The grouping number, together with the most typical samples for each subgroup which made up the firstly built typical color dataset, was determined by wilcoxon signed rank test according to the color inconstancy index comprehensively calculated under 6 typical illuminating conditions. Considering the completeness of gamut of Dunhuang wall paintings, 8 complementary colors was determined and finally the typical spectral color dataset was built up which contains 100 representative spectral colors. The analytical calculating results show that the median color inconstancy index of the built dataset in 99% confidence level by wilcoxon signed rank test was 3.28 and the 100 colors are distributing in the whole gamut uniformly, which ensures that this dataset can provide reasonable reference for choosing the color with highest color constancy during the color rendering process of Dunhuang cultural heritage.

The effect of memory and context changes on color matches to real objects.

PubMed

Allred, Sarah R; Olkkonen, Maria

2015-07-01

Real-world color identification tasks often require matching the color of objects between contexts and after a temporal delay, thus placing demands on both perceptual and memory processes. Although the mechanisms of matching colors between different contexts have been widely studied under the rubric of color constancy, little research has investigated the role of long-term memory in such tasks or how memory interacts with color constancy. To investigate this relationship, observers made color matches to real study objects that spanned color space, and we independently manipulated the illumination impinging on the objects, the surfaces in which objects were embedded, and the delay between seeing the study object and selecting its color match. Adding a 10-min delay increased both the bias and variability of color matches compared to a baseline condition. These memory errors were well accounted for by modeling memory as a noisy but unbiased version of perception constrained by the matching methods. Surprisingly, we did not observe significant increases in errors when illumination and surround changes were added to the 10-minute delay, although the context changes alone did elicit significant errors.

Image enhancement and color constancy for a vehicle-mounted change detection system

NASA Astrophysics Data System (ADS)

Tektonidis, Marco; Monnin, David

2016-10-01

Vehicle-mounted change detection systems allow to improve situational awareness on outdoor itineraries of inter- est. Since the visibility of acquired images is often affected by illumination effects (e.g., shadows) it is important to enhance local contrast. For the analysis and comparison of color images depicting the same scene at different time points it is required to compensate color and lightness inconsistencies caused by the different illumination conditions. We have developed an approach for image enhancement and color constancy based on the center/surround Retinex model and the Gray World hypothesis. The combination of the two methods using a color processing function improves color rendition, compared to both methods. The use of stacked integral images (SII) allows to efficiently perform local image processing. Our combined Retinex/Gray World approach has been successfully applied to image sequences acquired on outdoor itineraries at different time points and a comparison with previous Retinex-based approaches has been carried out.

Chromatic aberration and the roles of double-opponent and color-luminance neurons in color vision.

PubMed

Vladusich, Tony

2007-03-01

How does the visual cortex encode color? I summarize a theory in which cortical double-opponent color neurons perform a role in color constancy and a complementary set of color-luminance neurons function to selectively correct for color fringes induced by chromatic aberration in the eye. The theory may help to resolve an ongoing debate concerning the functional properties of cortical receptive fields involved in color coding.

Colorimetric Characterization of Mobile Devices for Vision Applications.

PubMed

de Fez, Dolores; Luque, Maria José; García-Domene, Maria Carmen; Camps, Vicente; Piñero, David

2016-01-01

Available applications for vision testing in mobile devices usually do not include detailed setup instructions, sacrificing rigor to obtain portability and ease of use. In particular, colorimetric characterization processes are generally obviated. We show that different mobile devices differ also in colorimetric profile and that those differences limit the range of applications for which they are most adequate. The color reproduction characteristics of four mobile devices, two smartphones (Samsung Galaxy S4, iPhone 4s) and two tablets (Samsung Galaxy Tab 3, iPad 4), have been evaluated using two procedures: 3D LUT (Look Up Table) and a linear model assuming primary constancy and independence of the channels. The color reproduction errors have been computed with the CIEDE2000 color difference formula. There is good constancy of primaries but large deviations of additivity. The 3D LUT characterization yields smaller reproduction errors and dispersions for the Tab 3 and iPhone 4 devices, but for the iPad 4 and S4, both models are equally good. The smallest reproduction errors occur with both Apple devices, although the iPad 4 has the highest number of outliers of all devices with both colorimetric characterizations. Even though there is good constancy of primaries, the large deviations of additivity exhibited by the devices and the larger reproduction errors make any characterization based on channel independence not recommendable. The smartphone screens show, in average, the best color reproduction performance, particularly the iPhone 4, and therefore, they are more adequate for applications requiring precise color reproduction.

Image processing analysis of traditional Gestalt vision experiments

NASA Astrophysics Data System (ADS)

McCann, John J.

2002-06-01

In the late 19th century, the Gestalt Psychology rebelled against the popular new science of Psychophysics. The Gestalt revolution used many fascinating visual examples to illustrate that the whole is greater than the sum of all the parts. Color constancy was an important example. The physical interpretation of sensations and their quantification by JNDs and Weber fractions were met with innumerable examples in which two 'identical' physical stimuli did not look the same. The fact that large changes in the color of the illumination failed to change color appearance in real scenes demanded something more than quantifying the psychophysical response of a single pixel. The debates continues today with proponents of both physical, pixel-based colorimetry and perceptual, image- based cognitive interpretations. Modern instrumentation has made colorimetric pixel measurement universal. As well, new examples of unconscious inference continue to be reported in the literature. Image processing provides a new way of analyzing familiar Gestalt displays. Since the pioneering experiments by Fergus Campbell and Land, we know that human vision has independent spatial channels and independent color channels. Color matching data from color constancy experiments agrees with spatial comparison analysis. In this analysis, simple spatial processes can explain the different appearances of 'identical' stimuli by analyzing the multiresolution spatial properties of their surrounds. Benary's Cross, White's Effect, the Checkerboard Illusion and the Dungeon Illusion can all be understood by the analysis of their low-spatial-frequency components. Just as with color constancy, these Gestalt images are most simply described by the analysis of spatial components. Simple spatial mechanisms account for the appearance of 'identical' stimuli in complex scenes. It does not require complex, cognitive processes to calculate appearances in familiar Gestalt experiments.

Flower Constancy, Insect Psychology, and Plant Evolution

NASA Astrophysics Data System (ADS)

Chittka, Lars; Thomson, James D.; Waser, Nickolas M.

Individuals of some species of pollinating insects tend to restrict their visits to only a few of the available plant species, in the process bypassing valuable food sources. The question of why this flower constancy exists is a rich and important one with implications for the organization of natural communities of plants, floral evolution, and our understanding of the learning processes involved in finding food. Some scientists have assumed that flower constancy is adaptive per se. Others argued that constancy occurs because memory capacity for floral features in insects is limited, but attempts to identify the limitations often remained rather simplistic. We elucidate now different sensory and motor memories from natural foraging tasks are stored and retrieved, using concepts from modern learning science and visual search, and conclude that flower constancy is likely to have multiple causes. Possible constraints favoring constancy are interference sensitivity of short-term memory, and temporal limitations on retrieving information from long-term memory as rapidly as from short-term memory, but further empirical evidence is needed to substantiate these possibilities. In addition, retrieving memories may be slower and more prone to errors when there are several options than when an insect copes with only a single task. In addition to memory limitations, we also point out alternative explanations for flower constancy. We then consider the way in which floral parameters, such as interplant distances, nectar rewards, flower morphology, and floral color (as seen through bees' eyes) affect constancy. Finally, we discuss the implications of pollinator constancy for plant evolution. To date there is no evidence that flowers have diverged to favor constancy, although the appropriate tests may not have yet been conducted. However, there is good evidence against the notion that pollinator constancy is involved in speciation or maintenance of plant species integrity.

The Application of Support Vector Machine (svm) Using Cielab Color Model, Color Intensity and Color Constancy as Features for Ortho Image Classification of Benthic Habitats in Hinatuan, Surigao del Sur, Philippines

NASA Astrophysics Data System (ADS)

Cubillas, J. E.; Japitana, M.

2016-06-01

This study demonstrates the application of CIELAB, Color intensity, and One Dimensional Scalar Constancy as features for image recognition and classifying benthic habitats in an image with the coastal areas of Hinatuan, Surigao Del Sur, Philippines as the study area. The study area is composed of four datasets, namely: (a) Blk66L005, (b) Blk66L021, (c) Blk66L024, and (d) Blk66L0114. SVM optimization was performed in Matlab® software with the help of Parallel Computing Toolbox to hasten the SVM computing speed. The image used for collecting samples for SVM procedure was Blk66L0114 in which a total of 134,516 sample objects of mangrove, possible coral existence with rocks, sand, sea, fish pens and sea grasses were collected and processed. The collected samples were then used as training sets for the supervised learning algorithm and for the creation of class definitions. The learned hyper-planes separating one class from another in the multi-dimensional feature space can be thought of as a super feature which will then be used in developing the C (classifier) rule set in eCognition® software. The classification results of the sampling site yielded an accuracy of 98.85% which confirms the reliability of remote sensing techniques and analysis employed to orthophotos like the CIELAB, Color Intensity and One dimensional scalar constancy and the use of SVM classification algorithm in classifying benthic habitats.

Color constancy for an unseen surface.

PubMed

Norman, Liam J; Akins, Kathleen; Heywood, Charles A; Kentridge, Robert W

2014-12-01

The illumination of a scene strongly affects our perception of objects in that scene, e.g., the pages of a book illuminated by candlelight will appear quite yellow relative to other types of artificial illuminants. Yet at the same time, the reader still judges the pages as white, their surface color unaffected by the interplay of paper and illuminant. It has been shown empirically that we can indeed report two quite different interpretations of "color": one is dependent on the constant surface spectral reflectance of an object (surface color) and the other on the power of light of different wavelengths reflected from that object (reflected color). How then are these two representations related? The common view, dating from Aristotle, is that our experience of surface color is derived from reflected color or, in more familiar terms, that color perception follows from color sensation. By definition, color constancy requires that vision "discounts the illuminant"; thus, it seems reasonable that vision begins with the color of objects as they naively appear and that we infer from their appearances their surface color. Here, we question this classic view. We use metacontrast-masked priming and, by presenting the unseen prime and the visible mask under different illuminants, dissociate two ways in which the prime matched the mask: in surface color or in reflected color. We find that priming of the mask occurs when it matches the prime in surface color, not reflected color. It follows that color perception can arise without prior color sensation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Generalization of color-difference formulas for any illuminant and any observer by assuming perfect color constancy in a color-vision model based on the OSA-UCS system.

PubMed

Oleari, Claudio; Melgosa, Manuel; Huertas, Rafael

2011-11-01

The most widely used color-difference formulas are based on color-difference data obtained under D65 illumination or similar and for a 10° visual field; i.e., these formulas hold true for the CIE 1964 observer adapted to D65 illuminant. This work considers the psychometric color-vision model based on the Optical Society of America-Uniform Color Scales (OSA-UCS) system previously published by the first author [J. Opt. Soc. Am. A 21, 677 (2004); Color Res. Appl. 30, 31 (2005)] with the additional hypothesis that complete illuminant adaptation with perfect color constancy exists in the visual evaluation of color differences. In this way a computational procedure is defined for color conversion between different illuminant adaptations, which is an alternative to the current chromatic adaptation transforms. This color conversion allows the passage between different observers, e.g., CIE 1964 and CIE 1931. An application of this color conversion is here made in the color-difference evaluation for any observer and in any illuminant adaptation: these transformations convert tristimulus values related to any observer and illuminant adaptation to those related to the observer and illuminant adaptation of the definition of the color-difference formulas, i.e., to the CIE 1964 observer adapted to the D65 illuminant, and then the known color-difference formulas can be applied. The adaptations to the illuminants A, C, F11, D50, Planckian and daylight at any color temperature and for CIE 1931 and CIE 1964 observers are considered as examples, and all the corresponding transformations are given for practical use.

Improving color constancy by discounting the variation of camera spectral sensitivity

NASA Astrophysics Data System (ADS)

Gao, Shao-Bing; Zhang, Ming; Li, Chao-Yi; Li, Yong-Jie

2017-08-01

It is an ill-posed problem to recover the true scene colors from a color biased image by discounting the effects of scene illuminant and camera spectral sensitivity (CSS) at the same time. Most color constancy (CC) models have been designed to first estimate the illuminant color, which is then removed from the color biased image to obtain an image taken under white light, without the explicit consideration of CSS effect on CC. This paper first studies the CSS effect on illuminant estimation arising in the inter-dataset-based CC (inter-CC), i.e., training a CC model on one dataset and then testing on another dataset captured by a distinct CSS. We show the clear degradation of existing CC models for inter-CC application. Then a simple way is proposed to overcome such degradation by first learning quickly a transform matrix between the two distinct CSSs (CSS-1 and CSS-2). The learned matrix is then used to convert the data (including the illuminant ground truth and the color biased images) rendered under CSS-1 into CSS-2, and then train and apply the CC model on the color biased images under CSS-2, without the need of burdensome acquiring of training set under CSS-2. Extensive experiments on synthetic and real images show that our method can clearly improve the inter-CC performance for traditional CC algorithms. We suggest that by taking the CSS effect into account, it is more likely to obtain the truly color constant images invariant to the changes of both illuminant and camera sensors.

Efficient image enhancement using sparse source separation in the Retinex theory

NASA Astrophysics Data System (ADS)

Yoon, Jongsu; Choi, Jangwon; Choe, Yoonsik

2017-11-01

Color constancy is the feature of the human vision system (HVS) that ensures the relative constancy of the perceived color of objects under varying illumination conditions. The Retinex theory of machine vision systems is based on the HVS. Among Retinex algorithms, the physics-based algorithms are efficient; however, they generally do not satisfy the local characteristics of the original Retinex theory because they eliminate global illumination from their optimization. We apply the sparse source separation technique to the Retinex theory to present a physics-based algorithm that satisfies the locality characteristic of the original Retinex theory. Previous Retinex algorithms have limited use in image enhancement because the total variation Retinex results in an overly enhanced image and the sparse source separation Retinex cannot completely restore the original image. In contrast, our proposed method preserves the image edge and can very nearly replicate the original image without any special operation.

A gestalt account of lightness illusions.

PubMed

Gilchrist, Alan

2014-01-01

Illusions of lightness offer valuable clues to how lightness values are computed by the visual system. The traditional domain of lightness illusions must be expanded to include failures of constancy, as there is no distinction between these categories. Just as lightness is (relatively) constant in the face of changes in illumination level, so it is equally constant in the face of changes in background reflectance. Simultaneous lightness contrast, the most familiar lightness illusion, is fairly weak, and represents a failure of background-independent lightness constancy. It is argued that a combination of the highest-luminance rule of anchoring plus the Kardos idea of codetermination can account for most lightness illusions. Kardos suggested that the lightness value of a target surface is partly determined relative to the field of illumination (or framework) in which it is embedded, and partly relative to the neighboring field of illumination. Although Kardos did not apply his principle of codetermination to failures of background-independent constancy such as the simultaneous contrast illusion, this can be done rather easily by defining a framework as a perceptual group instead of identifying it strictly with an objective field of illumination.

Application Principles for Multicolored Displays: A Workshop Report

DTIC Science & Technology

1990-01-01

Currently two systems, CIELUV and CIELAB , are recommended by the CIE for preliminary trials. Both systems start with measurement of the CIE chromaticity...difficulties in the extrapolation. In order to predict color appearance and take into account color constancy, both the CIELUV and CIELAB systems...both CIELUV and CIELAB it is possible to calculate approximate correlates of the perceived attributes of lightness, hue, saturation, and perceived

The Constancy of Colored After-Images

PubMed Central

Zeki, Semir; Cheadle, Samuel; Pepper, Joshua; Mylonas, Dimitris

2017-01-01

We undertook psychophysical experiments to determine whether the color of the after-image produced by viewing a colored patch which is part of a complex multi-colored scene depends on the wavelength-energy composition of the light reflected from that patch. Our results show that it does not. The after-image, just like the color itself, depends on the ratio of light of different wavebands reflected from it and its surrounds. Hence, traditional accounts of after-images as being the result of retinal adaptation or the perceptual result of physiological opponency, are inadequate. We propose instead that the color of after-images is generated after colors themselves are generated in the visual brain. PMID:28539878

Color Algebras

NASA Technical Reports Server (NTRS)

Mulligan, Jeffrey B.

2017-01-01

A color algebra refers to a system for computing sums and products of colors, analogous to additive and subtractive color mixtures. The difficulty addressed here is the fact that, because of metamerism, we cannot know with certainty the spectrum that produced a particular color solely on the basis of sensory data. Knowledge of the spectrum is not required to compute additive mixture of colors, but is critical for subtractive (multiplicative) mixture. Therefore, we cannot predict with certainty the multiplicative interactions between colors based solely on sensory data. There are two potential applications of a color algebra: first, to aid modeling phenomena of human visual perception, such as color constancy and transparency; and, second, to provide better models of the interactions of lights and surfaces for computer graphics rendering.

Effects of chromatic image statistics on illumination induced color differences.

PubMed

Lucassen, Marcel P; Gevers, Theo; Gijsenij, Arjan; Dekker, Niels

2013-09-01

We measure the color fidelity of visual scenes that are rendered under different (simulated) illuminants and shown on a calibrated LCD display. Observers make triad illuminant comparisons involving the renderings from two chromatic test illuminants and one achromatic reference illuminant shown simultaneously. Four chromatic test illuminants are used: two along the daylight locus (yellow and blue), and two perpendicular to it (red and green). The observers select the rendering having the best color fidelity, thereby indirectly judging which of the two test illuminants induces the smallest color differences compared to the reference. Both multicolor test scenes and natural scenes are studied. The multicolor scenes are synthesized and represent ellipsoidal distributions in CIELAB chromaticity space having the same mean chromaticity but different chromatic orientations. We show that, for those distributions, color fidelity is best when the vector of the illuminant change (pointing from neutral to chromatic) is parallel to the major axis of the scene's chromatic distribution. For our selection of natural scenes, which generally have much broader chromatic distributions, we measure a higher color fidelity for the yellow and blue illuminants than for red and green. Scrambled versions of the natural images are also studied to exclude possible semantic effects. We quantitatively predict the average observer response (i.e., the illuminant probability) with four types of models, differing in the extent to which they incorporate information processing by the visual system. Results show different levels of performance for the models, and different levels for the multicolor scenes and the natural scenes. Overall, models based on the scene averaged color difference have the best performance. We discuss how color constancy algorithms may be improved by exploiting knowledge of the chromatic distribution of the visual scene.

Thermal and optical aspects of glob-top design for phosphor converted white LED light sources

NASA Astrophysics Data System (ADS)

Sommer, Christian; Fulmek, Paul; Nicolics, Johann; Schweitzer, Susanne; Nemitz, Wolfgang; Hartmann, Paul; Pachler, Peter; Hoschopf, Hans; Schrank, Franz; Langer, Gregor; Wenzl, Franz P.

2013-09-01

For a systematic approach to improve the white light quality of phosphor converted light-emitting diodes (LEDs) for general lighting applications it is imperative to get the individual sources of error for correlated color temperature (CCT) reproducibility and maintenance under control. In this regard, it is of essential importance to understand how geometrical, optical and thermal properties of the color conversion elements (CCE), which typically consist of phosphor particles embedded in a transparent matrix material, affect the constancy of a desired CCT value. In this contribution we use an LED assembly consisting of an LED die mounted on a printed circuit board by chip-on-board technology and a CCE with a glob-top configuration on the top of it as a model system and discuss the impact of the CCE shape and size on CCT constancy with respect to substrate reflectivity and thermal load of the CCEs. From these studies, some general conclusions for improved glob-top design can be drawn.

How Children Respond to Art.

ERIC Educational Resources Information Center

Nodelman, Perry

1984-01-01

This essay discusses 13 pictorial devices with which one must be familiar to understand the illustrations in Virginia Lee Burton's "Mike Mulligan and His Steam Shovel." Color constancy, implied background, sharply drawn lines, abstractions of caricature, use of perspective, face on objects, and picture book narration are noted. (EJS)

Gamut relativity: a new computational approach to brightness and lightness perception.

PubMed

Vladusich, Tony

2013-01-09

This article deconstructs the conventional theory that "brightness" and "lightness" constitute perceptual dimensions corresponding to the physical dimensions of luminance and reflectance, and builds in its place the theory that brightness and lightness correspond to computationally defined "modes," rather than dimensions, of perception. According to the theory, called gamut relativity, "blackness" and "whiteness" constitute the perceptual dimensions (forming a two-dimensional "blackness-whiteness" space) underlying achromatic color perception (black, white, and gray shades). These perceptual dimensions are postulated to be related to the neural activity levels in the ON and OFF channels of vision. The theory unifies and generalizes a number of extant concepts in the brightness and lightness literature, such as simultaneous contrast, anchoring, and scission, and quantitatively simulates several challenging perceptual phenomena, including the staircase Gelb effect and the effects of task instructions on achromatic color-matching behavior, all with a single free parameter. The theory also provides a new conception of achromatic color constancy in terms of the relative distances between points in blackness-whiteness space. The theory suggests a host of striking conclusions, the most important of which is that the perceptual dimensions of vision should be generically specified according to the computational properties of the brain, rather than in terms of "reified" physical dimensions. This new approach replaces the computational goal of estimating absolute physical quantities ("inverse optics") with the goal of computing object properties relatively.

Towards representation of a perceptual color manifold using associative memory for color constancy.

PubMed

Seow, Ming-Jung; Asari, Vijayan K

2009-01-01

In this paper, we propose the concept of a manifold of color perception through empirical observation that the center-surround properties of images in a perceptually similar environment define a manifold in the high dimensional space. Such a manifold representation can be learned using a novel recurrent neural network based learning algorithm. Unlike the conventional recurrent neural network model in which the memory is stored in an attractive fixed point at discrete locations in the state space, the dynamics of the proposed learning algorithm represent memory as a nonlinear line of attraction. The region of convergence around the nonlinear line is defined by the statistical characteristics of the training data. This learned manifold can then be used as a basis for color correction of the images having different color perception to the learned color perception. Experimental results show that the proposed recurrent neural network learning algorithm is capable of color balance the lighting variations in images captured in different environments successfully.

Number of perceptually distinct surface colors in natural scenes.

PubMed

Marín-Franch, Iván; Foster, David H

2010-09-30

The ability to perceptually identify distinct surfaces in natural scenes by virtue of their color depends not only on the relative frequency of surface colors but also on the probabilistic nature of observer judgments. Previous methods of estimating the number of discriminable surface colors, whether based on theoretical color gamuts or recorded from real scenes, have taken a deterministic approach. Thus, a three-dimensional representation of the gamut of colors is divided into elementary cells or points which are spaced at one discrimination-threshold unit intervals and which are then counted. In this study, information-theoretic methods were used to take into account both differing surface-color frequencies and observer response uncertainty. Spectral radiances were calculated from 50 hyperspectral images of natural scenes and were represented in a perceptually almost uniform color space. The average number of perceptually distinct surface colors was estimated as 7.3 × 10(3), much smaller than that based on counting methods. This number is also much smaller than the number of distinct points in a scene that are, in principle, available for reliable identification under illuminant changes, suggesting that color constancy, or the lack of it, does not generally determine the limit on the use of color for surface identification.

Target recognitions in multiple-camera closed-circuit television using color constancy

NASA Astrophysics Data System (ADS)

Soori, Umair; Yuen, Peter; Han, Ji Wen; Ibrahim, Izzati; Chen, Wentao; Hong, Kan; Merfort, Christian; James, David; Richardson, Mark

2013-04-01

People tracking in crowded scenes from closed-circuit television (CCTV) footage has been a popular and challenging task in computer vision. Due to the limited spatial resolution in the CCTV footage, the color of people's dress may offer an alternative feature for their recognition and tracking. However, there are many factors, such as variable illumination conditions, viewing angles, and camera calibration, that may induce illusive modification of intrinsic color signatures of the target. Our objective is to recognize and track targets in multiple camera views using color as the detection feature, and to understand if a color constancy (CC) approach may help to reduce these color illusions due to illumination and camera artifacts and thereby improve target recognition performance. We have tested a number of CC algorithms using various color descriptors to assess the efficiency of target recognition from a real multicamera Imagery Library for Intelligent Detection Systems (i-LIDS) data set. Various classifiers have been used for target detection, and the figure of merit to assess the efficiency of target recognition is achieved through the area under the receiver operating characteristics (AUROC). We have proposed two modifications of luminance-based CC algorithms: one with a color transfer mechanism and the other using a pixel-wise sigmoid function for an adaptive dynamic range compression, a method termed enhanced luminance reflectance CC (ELRCC). We found that both algorithms improve the efficiency of target recognitions substantially better than that of the raw data without CC treatment, and in some cases the ELRCC improves target tracking by over 100% within the AUROC assessment metric. The performance of the ELRCC has been assessed over 10 selected targets from three different camera views of the i-LIDS footage, and the averaged target recognition efficiency over all these targets is found to be improved by about 54% in AUROC after the data are processed by the proposed ELRCC algorithm. This amount of improvement represents a reduction of probability of false alarm by about a factor of 5 at the probability of detection of 0.5. Our study concerns mainly the detection of colored targets; and issues for the recognition of white or gray targets will be addressed in a forthcoming study.

Which are the colors of the dress? Review of an atypical optic illusion.

PubMed

González Martín-Moro, J; Prieto Garrido, F; Gómez Sanz, F; Fuentes Vega, I; Castro Rebollo, M; Moreno Martín, P

2018-04-01

In 2015 the picture of a dress went viral on social media. A significant proportion of the population saw it as golden and white (G&W), while another significant proportion saw it as blue and black (B&B). The aim of this article is to review the related literature. Bibliographic search conducted in Pubmed and Google. The algorithm used was: (color OR colour) AND (dress OR #thedress). The search was limited to the years 2015-2017. No language restrictions were used. The references of the located articles were used to widen the search. The search algorithm retrieved 23 articles related to the topic. Most of the works have been published in journals in the field of perception. Most works address the topic from the point of view of chromatic constancy. Genetic factors seem to have a low weight in the way the dress is perceived. There are few studies on the potential influence of ocular factors. This illusion has gained little attention in ophthalmology journals. Although colour constancy is certainly involved, there is still no theory available to explain the dichotomous character of this optical illusion. Copyright © 2018 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

WhitebalPR: automatic white balance by polarized reflections

NASA Astrophysics Data System (ADS)

Fischer, Gregor; Kolbe, Karin; Sajjaa, Matthias

2008-02-01

This new color constancy method is based on the polarization degree of that light which is reflected at the surface of an object. The subtraction of at least two images taken under different polarization directions detects the polarization degree of the neutrally reflected portions and eliminates the remitted non-polarized colored portions. Two experiments have been designed to clarify the performance of the procedure, one to multicolored objects and another to objects of different surface characteristics. The results show that the mechanism of eliminating the remitted, non-polarized colored portions of light works very fine. Independent from its color, different color pigments seem to be suitable for measuring the color of the illumination. The intensity and also the polarization degree of the reflected light depend on the surface properties significantly. The results exhibit a high accuracy of measuring the color of the illumination for glossy and matt surfaces. Only strongly scattering surfaces account for a weak signal level of the difference image and a reduced accuracy. An embodiment is proposed to integrate the new method into digital cameras.

Color Algebras

NASA Technical Reports Server (NTRS)

Mulligan, Jeffrey B.

2017-01-01

A color algebra refers to a system for computing sums and products of colors, analogous to additive and subtractive color mixtures. We would like it to match the well-defined algebra of spectral functions describing lights and surface reflectances, but an exact correspondence is impossible after the spectra have been projected to a three-dimensional color space, because of metamerism physically different spectra can produce the same color sensation. Metameric spectra are interchangeable for the purposes of addition, but not multiplication, so any color algebra is necessarily an approximation to physical reality. Nevertheless, because the majority of naturally-occurring spectra are well-behaved (e.g., continuous and slowly-varying), color algebras can be formulated that are largely accurate and agree well with human intuition. Here we explore the family of algebras that result from associating each color with a member of a three-dimensional manifold of spectra. This association can be used to construct a color product, defined as the color of the spectrum of the wavelength-wise product of the spectra associated with the two input colors. The choice of the spectral manifold determines the behavior of the resulting system, and certain special subspaces allow computational efficiencies. The resulting systems can be used to improve computer graphic rendering techniques, and to model various perceptual phenomena such as color constancy.

Color appearance of familiar objects: effects of object shape, texture, and illumination changes.

PubMed

Olkkonen, Maria; Hansen, Thorsten; Gegenfurtner, Karl R

2008-05-26

People perceive roughly constant surface colors despite large changes in illumination. The familiarity of colors of some natural objects might help achieve this feat through direct modulation of the objects' color appearance. Research on memory colors and color appearance has yielded controversial results and due to the employed methods has often confounded perceptual with semantic effects. We studied the effect of memory colors on color appearance by presenting photographs of fruit on a monitor under various simulated illuminations and by asking observers to make either achromatic or typical color settings without placing demands on short-term memory or semantic processing. In a control condition, we presented photographs of 3D fruit shapes without texture and 2D outline shapes. We found that (1) achromatic settings for fruit were systematically biased away from the gray point toward the opposite direction of a fruit's memory color; (2) the strength of the effect depended on the degree of naturalness of the stimuli; and (3) the effect was evident under all tested illuminations, being strongest for illuminations whose chromaticity was closest to the stimulus chromaticity. We conclude that the visual identity of an object has a measurable effect on color perception, and that this effect is robust under illuminant changes, indicating its potential significance as an additional mechanism for color constancy.

Computational models of human vision with applications

NASA Technical Reports Server (NTRS)

Wandell, B. A.

1985-01-01

Perceptual problems in aeronautics were studied. The mechanism by which color constancy is achieved in human vision was examined. A computable algorithm was developed to model the arrangement of retinal cones in spatial vision. The spatial frequency spectra are similar to the spectra of actual cone mosaics. The Hartley transform as a tool of image processing was evaluated and it is suggested that it could be used in signal processing applications, GR image processing.

Project Report: Reducing Color Rivalry in Imagery for Conjugated Multiple Bandpass Filter Based Stereo Endoscopy

NASA Technical Reports Server (NTRS)

Ream, Allen

2011-01-01

A pair of conjugated multiple bandpass filters (CMBF) can be used to create spatially separated pupils in a traditional lens and imaging sensor system allowing for the passive capture of stereo video. This method is especially useful for surgical endoscopy where smaller cameras are needed to provide ample room for manipulating tools while also granting improved visualizations of scene depth. The significant issue in this process is that, due to the complimentary nature of the filters, the colors seen through each filter do not match each other, and also differ from colors as seen under a white illumination source. A color correction model was implemented that included optimized filter selection, such that the degree of necessary post-processing correction was minimized, and a chromatic adaptation transformation that attempted to fix the imaged colors tristimulus indices based on the principle of color constancy. Due to fabrication constraints, only dual bandpass filters were feasible. The theoretical average color error after correction between these filters was still above the fusion limit meaning that rivalry conditions are possible during viewing. This error can be minimized further by designing the filters for a subset of colors corresponding to specific working environments.

Illumination estimation via thin-plate spline interpolation.

PubMed

Shi, Lilong; Xiong, Weihua; Funt, Brian

2011-05-01

Thin-plate spline interpolation is used to interpolate the chromaticity of the color of the incident scene illumination across a training set of images. Given the image of a scene under unknown illumination, the chromaticity of the scene illumination can be found from the interpolated function. The resulting illumination-estimation method can be used to provide color constancy under changing illumination conditions and automatic white balancing for digital cameras. A thin-plate spline interpolates over a nonuniformly sampled input space, which in this case is a training set of image thumbnails and associated illumination chromaticities. To reduce the size of the training set, incremental k medians are applied. Tests on real images demonstrate that the thin-plate spline method can estimate the color of the incident illumination quite accurately, and the proposed training set pruning significantly decreases the computation.

Spatial imaging in color and HDR: prometheus unchained

NASA Astrophysics Data System (ADS)

McCann, John J.

2013-03-01

The Human Vision and Electronic Imaging Conferences (HVEI) at the IS and T/SPIE Electronic Imaging meetings have brought together research in the fundamentals of both vision and digital technology. This conference has incorporated many color disciplines that have contributed to the theory and practice of today's imaging: color constancy, models of vision, digital output, high-dynamic-range imaging, and the understanding of perceptual mechanisms. Before digital imaging, silver halide color was a pixel-based mechanism. Color films are closely tied to colorimetry, the science of matching pixels in a black surround. The quanta catch of the sensitized silver salts determines the amount of colored dyes in the final print. The rapid expansion of digital imaging over the past 25 years has eliminated the limitations of using small local regions in forming images. Spatial interactions can now generate images more like vision. Since the 1950's, neurophysiology has shown that post-receptor neural processing is based on spatial interactions. These results reinforced the findings of 19th century experimental psychology. This paper reviews the role of HVEI in color, emphasizing the interaction of research on vision and the new algorithms and processes made possible by electronic imaging.

Does reproductive isolation reflect the segregation of color forms in Spiranthes sinensis (Pers.) Ames complex (Orchidaceae) in the Chinese Himalayas?

PubMed

Tao, Zhi-Bin; Ren, Zong-Xin; Bernhardt, Peter; Liang, Huan; Li, Hai-Dong; Zhao, Yan-Hui; Wang, Hong; Li, De-Zhu

2018-06-01

Isolation between species, or taxa sharing a common lineage, depends primarily on the relative strengths of various reproductive barriers. Previous studies on reproductive isolation between orchids emphasized mechanical and ethological barriers in flowers of species showing food and/or sexual mimicry. In this study, we investigated and quantified a series of prepollination and postpollination barriers between pink and white forms of Spiranthes sinensis sl, a nectar-secreting complex. We generated ML trees based on trn S-G and mat K to explore phylogenetic relationships in this species complex. Spiranthes sinensis sl segregated from some other congeners, but the white form constituted a distinct clade in relation to the pink form. The white form secreted 2-Phenylethanol as it is a single-scent compound and was pollinated almost exclusively by native, large-bodied Apis cerana and Bombus species (Apidae). Apis cerana showed a high floral constancy to this form. The scentless, pink form was pollinated primarily by smaller bees in the genera Ceratina (Apidae), and members of the family Halictidae, with infrequent visits by A. cerana and Bombus species. Fruit set and the production of large embryos following interform pollination treatments were significantly lower compared to intraform pollination results for the white form. Our results suggested that pollinator isolation, based on color and scent cues, may result in greater floral constancy in white populations when both forms are sympatric as two different, guilds of pollinators forage selectively preventing or reducing prospective gene flow. Postpollination barriers appear weaker than prepollination barriers but they also play a role in interform isolation, especially in the white form. Our findings suggest that floral color forms in S. sinensis do not represent an unbalanced polymorphism. Interpretations of the evolutionary status of these forms are discussed.

New experimental diffractive-optical data on E.Land's Retinex mechanism in human color vision: Part II

NASA Astrophysics Data System (ADS)

Lauinger, N.

2007-09-01

A better understanding of the color constancy mechanism in human color vision [7] can be reached through analyses of photometric data of all illuminants and patches (Mondrians or other visible objects) involved in visual experiments. In Part I [3] and in [4, 5 and 6] the integration in the human eye of the geometrical-optical imaging hardware and the diffractive-optical hardware has been described and illustrated (Fig.1). This combined hardware represents the main topic of the NAMIROS research project (nano- and micro- 3D gratings for optical sensors) [8] promoted and coordinated by Corrsys 3D Sensors AG. The hardware relevant to (photopic) human color vision can be described as a diffractive or interference-optical correlator transforming incident light into diffractive-optical RGB data and relating local RGB onto global RGB data in the near-field behind the 'inverted' human retina. The relative differences at local/global RGB interference-optical contrasts are available to photoreceptors (cones and rods) only after this optical pre-processing.

An experimental test of the effects of gender constancy on sex typing.

PubMed

Arthur, Andrea E; Bigler, Rebecca S; Ruble, Diane N

2009-12-01

This study provides an experimental test of the hypothesis that level of gender constancy understanding affects children's sex typing. Preschool-age children (N=62, mean age=47 months) were randomly assigned to experimental lessons that taught that biological traits (including gender) are either fixed (pro-constancy condition) or mutable (anti-constancy condition). Posttests revealed that the lessons were effective; children in the pro-constancy condition showed higher gender constancy and appearance-reality distinction scores than did children in the anti-constancy condition. Sex typing did not, however, differ between treatment conditions at immediate and 3-month posttesting.

Method of improving a digital image

NASA Technical Reports Server (NTRS)

Jobson, Daniel J. (Inventor); Woodell, Glenn A. (Inventor); Rahman, Zia-ur (Inventor)

1999-01-01

A method of improving a digital image is provided. The image is initially represented by digital data indexed to represent positions on a display. The digital data is indicative of an intensity value I.sub.i (x,y) for each position (x,y) in each i-th spectral band. The intensity value for each position in each i-th spectral band is adjusted to generate an adjusted intensity value for each position in each i-th spectral band in accordance with ##EQU1## where S is the number of unique spectral bands included in said digital data, W.sub.n is a weighting factor and * denotes the convolution operator. Each surround function F.sub.n (x,y) is uniquely scaled to improve an aspect of the digital image, e.g., dynamic range compression, color constancy, and lightness rendition. The adjusted intensity value for each position in each i-th spectral band is filtered with a common function and then presented to a display device. For color images, a novel color restoration step is added to give the image true-to-life color that closely matches human observation.

Retinex at 50: color theory and spatial algorithms, a review

NASA Astrophysics Data System (ADS)

McCann, John J.

2017-05-01

Retinex Imaging shares two distinct elements: first, a model of human color vision; second, a spatial-imaging algorithm for making better reproductions. Edwin Land's 1964 Retinex Color Theory began as a model of human color vision of real complex scenes. He designed many experiments, such as Color Mondrians, to understand why retinal cone quanta catch fails to predict color constancy. Land's Retinex model used three spatial channels (L, M, S) that calculated three independent sets of monochromatic lightnesses. Land and McCann's lightness model used spatial comparisons followed by spatial integration across the scene. The parameters of their model were derived from extensive observer data. This work was the beginning of the second Retinex element, namely, using models of spatial vision to guide image reproduction algorithms. Today, there are many different Retinex algorithms. This special section, "Retinex at 50," describes a wide variety of them, along with their different goals, and ground truths used to measure their success. This paper reviews (and provides links to) the original Retinex experiments and image-processing implementations. Observer matches (measuring appearances) have extended our understanding of how human spatial vision works. This paper describes a collection very challenging datasets, accumulated by Land and McCann, for testing algorithms that predict appearance.

Flower constancy in insect pollinators

PubMed Central

Ratnieks, Francis L.W.

2011-01-01

As first noted by Aristotle in honeybee workers, many insect pollinators show a preference to visit flowers of just one species during a foraging trip. This “flower constancy” probably benefits plants, because pollen is more likely to be deposited on conspecific stigmas. But it is less clear why insects should ignore rewarding alternative flowers. Many researchers have argued that flower constancy is caused by constraints imposed by insect nervous systems rather than because flower constancy is itself an efficient foraging method. We argue that this view is unsatisfactory because it both fails to explain why foragers flexibly adjust the degree of flower constancy and does not explain why foragers of closely related species show different degrees of constancy. While limitations of the nervous system exist and are likely to influence flower constancy to some degree, the observed behavioural flexibility suggests that flower constancy is a successful foraging strategy given the insect’s own information about different foraging options. PMID:22446521

Scene Context Dependency of Pattern Constancy of Time Series Imagery

NASA Technical Reports Server (NTRS)

Woodell, Glenn A.; Jobson, Daniel J.; Rahman, Zia-ur

2008-01-01

A fundamental element of future generic pattern recognition technology is the ability to extract similar patterns for the same scene despite wide ranging extraneous variables, including lighting, turbidity, sensor exposure variations, and signal noise. In the process of demonstrating pattern constancy of this kind for retinex/visual servo (RVS) image enhancement processing, we found that the pattern constancy performance depended somewhat on scene content. Most notably, the scene topography and, in particular, the scale and extent of the topography in an image, affects the pattern constancy the most. This paper will explore these effects in more depth and present experimental data from several time series tests. These results further quantify the impact of topography on pattern constancy. Despite this residual inconstancy, the results of overall pattern constancy testing support the idea that RVS image processing can be a universal front-end for generic visual pattern recognition. While the effects on pattern constancy were significant, the RVS processing still does achieve a high degree of pattern constancy over a wide spectrum of scene content diversity, and wide ranging extraneousness variations in lighting, turbidity, and sensor exposure.

Determinants of Colour Constancy and the Blue Bias

PubMed Central

Gegenfurtner, Karl

2017-01-01

We investigated several sensory and cognitive determinants of colour constancy across 40 illumination hues. In the first experiment, we measured colour naming for the illumination and for the colour induced by the illumination on the colorimetric grey. Results confirmed that the induced colours are approximately complementary to the colour of the illumination. In the second experiment, we measured colour constancy using achromatic adjustments. Average colour constancy was perfect under the blue daylight illumination and decreased in colour directions away from the blue daylight illumination due to undershooting and a strong blue bias. Apart from this blue bias, colour constancy was not related to illumination discrimination and to chromatic detection measured previously with the same setup and stimuli. We also observed a strong negative relationship between the degree of colour constancy and the consensus of naming the illumination colour. Constancy coincided with a low naming consensus, in particular because bluish illumination colours were sometimes seen as achromatic. Blue bias and category consensus alone explained >68%, and all determinants together explained >94% of the variance of achromatic adjustments. These findings suggest that colour constancy is optimised for blue daylight. PMID:29348910

Rethinking Colour Constancy.

PubMed

Logvinenko, Alexander D; Funt, Brian; Mirzaei, Hamidreza; Tokunaga, Rumi

2015-01-01

Colour constancy needs to be reconsidered in light of the limits imposed by metamer mismatching. Metamer mismatching refers to the fact that two objects reflecting metameric light under one illumination may reflect non-metameric light under a second; so two objects appearing as having the same colour under one illuminant can appear as having different colours under a second. Yet since Helmholtz, object colour has generally been believed to remain relatively constant. The deviations from colour constancy registered in experiments are usually thought to be small enough that they do not contradict the notion of colour constancy. However, it is important to determine how the deviations from colour constancy relate to the limits metamer mismatching imposes on constancy. Hence, we calculated metamer mismatching's effect for the 20 Munsell papers and 8 pairs of illuminants employed in the colour constancy study by Logvinenko and Tokunaga and found it to be so extensive that the two notions-metamer mismatching and colour constancy-must be mutually exclusive. In particular, the notion of colour constancy leads to some paradoxical phenomena such as the possibility of 20 objects having the same colour under chromatic light dispersing into a hue circle of colours under neutral light. Thus, colour constancy refers to a phenomenon, which because of metamer mismatching, simply cannot exist. Moreover, it obscures the really important visual phenomenon; namely, the alteration of object colours induced by illumination change. We show that colour is not an independent, intrinsic attribute of an object, but rather an attribute of an object/light pair, and then define a concept of material colour in terms of equivalence classes of such object/light pairs. We suggest that studying the shift in material colour under a change in illuminant will be more fruitful than pursuing colour constancy's false premise that colour is an intrinsic attribute of an object.

The Development of Gender Constancy in Early Childhood and Its Relation to Time Comprehension and False-Belief Understanding

ERIC Educational Resources Information Center

Zmyj, Norbert; Bischof-Köhler, Doris

2015-01-01

What is the developmental course of children's gender constancy? Do other cognitive abilities such as time comprehension and false-belief understanding foster gender constancy and the subcomponents gender stability and gender consistency? We examined the development of gender constancy and its relation to time comprehension and false-belief…

Colour constancy in insects.

PubMed

Chittka, Lars; Faruq, Samia; Skorupski, Peter; Werner, Annette

2014-06-01

Colour constancy is the perceptual phenomenon that the colour of an object appears largely unchanged, even if the spectral composition of the illuminating light changes. Colour constancy has been found in all insect species so far tested. Especially the pollinating insects offer a remarkable opportunity to study the ecological significance of colour constancy since they spend much of their adult lives identifying and choosing between colour targets (flowers) under continuously changing ambient lighting conditions. In bees, whose colour vision is best studied among the insects, the compensation provided by colour constancy is only partial and its efficiency depends on the area of colour space. There is no evidence for complete 'discounting' of the illuminant in bees, and the spectral composition of the light can itself be used as adaptive information. In patchy illumination, bees adjust their spatial foraging to minimise transitions between variously illuminated zones. Modelling allows the quantification of the adaptive benefits of various colour constancy mechanisms in the economy of nature. We also discuss the neural mechanisms and cognitive operations that might underpin colour constancy in insects.

Structures in color space

NASA Astrophysics Data System (ADS)

Petrov, Alexander P.

1996-09-01

Classic colorimetry and the traditionally used color space do not represent all perceived colors (for example, browns look dark yellow in colorimetric conditions of observation) so, the specific goal of this work is to suggest another concept of color and to prove that the corresponding set of colors is complete. The idea of our approach attributing color to surface patches (not to the light) immediately ties all the problems of color perception and vision geometry. The equivalence relation in the linear space of light fluxes F established by a procedure of colorimetry gives us a 3D color space H. By definition we introduce a sample (sigma) (surface patch) as a linear mapping (sigma) : L yields H, where L is a subspace of F called the illumination space. A Dedekind structure of partial order can be defined in the set of the samples: two samples (alpha) and (Beta) belong to one chromatic class if ker(alpha) equals ker(Beta) and (alpha) > (Beta) if ker(alpha) ker(Beta) . The maximal elements of this chain create the chromatic class BLACK. There can be given geometrical arguments for L to be 3D and it can be proved that in this case the minimal element of the above Dedekind structure is unique and the corresponding chromatic class is called WHITE containing the samples (omega) such that ker(omega) equals {0} L. Color is defined as mapping C: H yields H and assuming color constancy the complete set of perceived colors is proved to be isomorphic to a subset C of 3 X 3 matrices. This subset is convex, limited and symmetrical with E/2 as the center of symmetry. The problem of metrization of the color space C is discussed and a color metric related to shape, i.e., to vision geometry, is suggested.

Properties of a center/surround retinex. Part 1: Signal processing design

NASA Technical Reports Server (NTRS)

Rahaman, Zia-Ur

1995-01-01

The last version of Edwin Land's retinex model for human vision's lightness and color constancy has been implemented. Previous research has established the mathematical foundations of Land's retinex but has not examined specific design issues and their effects on the properties of the retinex operation. Here we describe the signal processing design of the retinex. We find that the placement of the logarithmic function is important and produces best results when placed after the surround formation. We also find that best rendition is obtained for a 'canonical' gain-offset applied after the retinex operation.

A Large Catalog of Multiwavelength GRB Afterglows. I. Color Evolution and Its Physical Implication

NASA Astrophysics Data System (ADS)

Li, Liang; Wang, Yu; Shao, Lang; Wu, Xue-Feng; Huang, Yong-Feng; Zhang, Bing; Ryde, Felix; Yu, Hoi-Fung

2018-02-01

The spectrum of gamma-ray burst (GRB) afterglows can be studied with color indices. Here, we present a large comprehensive catalog of 70 GRBs with multiwavelength optical transient data on which we perform a systematic study to find the temporal evolution of color indices. We categorize them into two samples based on how well the color indices are evaluated. The Golden sample includes 25 bursts mostly observed by GROND, and the Silver sample includes 45 bursts observed by other telescopes. For the Golden sample, we find that 96% of the color indices do not vary over time. However, the color indices do vary during short periods in most bursts. The observed variations are consistent with effects of (i) the cooling frequency crossing the studied energy bands in a wind medium (43%) and in a constant-density medium (30%), (ii) early dust extinction (12%), (iii) transition from reverse-shock to forward-shock emission (5%), or (iv) an emergent SN emission (10%). We also study the evolutionary properties of the mean color indices for different emission episodes. We find that 86% of the color indices in the 70 bursts show constancy between consecutive ones. The color index variations occur mainly during the late GRB–SN bump, the flare, and early reverse-shock emission components. We further perform a statistical analysis of various observational properties and model parameters (spectral index {β }o{CI}, electron spectral indices p CI, etc.) using color indices. Overall, we conclude that ∼90% of colors are constant in time and can be accounted for by the simplest external forward-shock model, while the varying color indices call for more detailed modeling.

Preliminary study of visual effect of multiplex hologram

NASA Astrophysics Data System (ADS)

Fu, Huaiping; Xiong, Bingheng; Yang, Hong; Zhang, Xueguo

2004-06-01

The process of any movement of real object can be recorded and displayed by a multiplex holographic stereogram. An embossing multiplex holographic stereogram and a multiplex rainbow holographic stereogram have been made by us, the multiplex rainbow holographic stereogram reconstructs the dynamic 2D line drawing of speech organs, the embossing multiplex holographic stereogram reconstructs the process of an old man drinking water. In this paper, we studied the visual result of an embossing multiplex holographic stereogram made with 80 films of 2-D pictures. Forty-eight persons of aged from 13 to 67 were asked to see the hologram and then to answer some questions about the feeling of viewing. The results indicate that this kind of holograms could be accepted by human visual sense organ without any problem. This paper also discusses visual effect of the multiplex holography stereograms base on visual perceptual psychology. It is open out that the planar multiplex holograms can be recorded and present the movement of real animal and object. Not only have the human visual perceptual constancy for shape, just as that size, color, etc... but also have visual perceptual constancy for binocular parallax.

Biosynthetic and functional color-scent associations in flowers of Papaver nudicaule and its impact on pollinators.

PubMed

Martinez-Harms, Jaime; Warskulat, Anne-Christin; Dudek, Bettina; Kunert, Grit; Lorenz, Sybille; Hansson, Bill S; Schneider, Bernd

2018-04-26

Despite the increasing evidence for biosynthetic connections between flower pigments and volatiles, examples of such relationships in polymorphic plant species remains limited. Here, we investigated color-scent associations in flowers from Papaver nudicaule (Papaveraceae). We determined the spectral reflectance and the scent composition of flowers of four color cultivars. We found that pigments and volatiles occur in specific combinations in flowers of P. nudicaule. The presence of indole in the bouquets is strongly associated with the occurrence of yellow pigments called nudicaulins, for which indole is one of the final biosynthetic precursors. While yellow flowers emit an excess of indole, orange flowers consume it during nudicaulin production and lack the substance in their bouquet. Using the honeybee, Apis mellifera, we evaluated how color and scent affect the discrimination of these flowers by pollinators. Honeybees were able to discriminate artificial odor mixtures resembling the natural flower odors. Bees trained with stimuli combining colors and odors showed an improved discrimination performance. Our results indicate that the indole moiety of nudicaulins and emitted indole might be products of the same biochemical pathway. We propose that conserved pathways account for the evolution of color-scent associations in P. nudicaule and that these associations positively affect flower constancy of pollinators. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantitative studies of animal colour constancy: using the chicken as model

PubMed Central

2016-01-01

Colour constancy is the capacity of visual systems to keep colour perception constant despite changes in the illumination spectrum. Colour constancy has been tested extensively in humans and has also been described in many animals. In humans, colour constancy is often studied quantitatively, but besides humans, this has only been done for the goldfish and the honeybee. In this study, we quantified colour constancy in the chicken by training the birds in a colour discrimination task and testing them in changed illumination spectra to find the largest illumination change in which they were able to remain colour-constant. We used the receptor noise limited model for animal colour vision to quantify the illumination changes, and found that colour constancy performance depended on the difference between the colours used in the discrimination task, the training procedure and the time the chickens were allowed to adapt to a new illumination before making a choice. We analysed literature data on goldfish and honeybee colour constancy with the same method and found that chickens can compensate for larger illumination changes than both. We suggest that future studies on colour constancy in non-human animals could use a similar approach to allow for comparison between species and populations. PMID:27170714

Properties of a center/surround retinex. Part 2: Surround design

NASA Technical Reports Server (NTRS)

Jobson, Daniel J.; Woodell, Glenn A.

1995-01-01

The last version of Edwin Land's retinex model for human vision's lightness and color constancy has been implemented. Previous research has established the mathematical foundations of Land's retinex but has not examined specific design issues and their effects on the properties of the retinex operation. We have sought to define a practical implementation of the retinex without particular concern for its validity as a model for human lightness and color perception. Here we describe issues involved in designing the surround function. We find that there is a trade-off between rendition and dynamic range compression that is governed by the surround space constant. Various functional forms for the retinex surround are evaluated and a Gaussian form is found to perform better than the inverse square suggested by Land. Preliminary testing led to the design of a Gaussian surround with a space constant of 80 pixels as a reasonable compromise between dynamic range compression and rendition.

Clear water radiances for atmospheric correction of coastal zone color scanner imagery

NASA Technical Reports Server (NTRS)

Gordon, H. R.; Clark, D. K.

1981-01-01

The possibility of computing the inherent sea surface radiance for regions of clear water from coastal zone color scanner (CZCS) imagery given only a knowledge of the local solar zenith angle is examined. The inherent sea surface radiance is related to the upwelling and downwelling irradiances just beneath the sea surface, and an expression is obtained for a normalized inherent sea surface radiance which is nearly independent of solar zenith angle for low phytoplankton pigment concentrations. An analysis of a data base consisting of vertical profiles of upwelled spectral radiance and pigment concentration, which was used in the development of the CZCS program, confirms the virtual constancy of the normalized inherent sea surface radiance at wavelengths of 520 and 550 nm for cases when the pigment concentration is less than 0.25 mg/cu m. A strategy is then developed for using the normalized inherent sea surface radiance in the atmospheric correction of CZCS imagery.

The impact of individual materials parameters on color temperature reproducibility among phosphor converted LED sources

NASA Astrophysics Data System (ADS)

Schweitzer, Susanne; Nemitz, Wolfgang; Sommer, Christian; Hartmann, Paul; Fulmek, Paul; Nicolics, Johann; Pachler, Peter; Hoschopf, Hans; Schrank, Franz; Langer, Gregor; Wenzl, Franz P.

2014-09-01

For a systematic approach to improve the white light quality of phosphor converted light-emitting diodes (LEDs) for general lighting applications it is imperative to get the individual sources of error for color temperature reproducibility under control. In this regard, it is imperative to understand how compositional, optical and materials properties of the color conversion element (CCE), which typically consists of phosphor particles embedded in a transparent matrix material, affect the constancy of a desired color temperature of a white LED source. In this contribution we use an LED assembly consisting of an LED die mounted on a printed circuit board (PCB) by chip-on-board technology and a CCE with a glob-top configuration as a model system and discuss the impact of potential sources for color temperature deviation among individual devices. Parameters that are investigated include imprecisions in the amount of materials deposition, deviations from the target value for the phosphor concentration in the matrix material, deviations from the target value for the particle sizes of the phosphor material, deviations from the target values for the refractive indexes of phosphor and matrix material as well as deviations from the reflectivity of the substrate surface. From these studies, some general conclusions can be drawn which of these parameters have the largest impact on color deviation and have to be controlled most precisely in a fabrication process in regard of color temperature reproducibility among individual white LED sources.

Stereoscopic depth constancy

PubMed Central

Guan, Phillip

2016-01-01

Depth constancy is the ability to perceive a fixed depth interval in the world as constant despite changes in viewing distance and the spatial scale of depth variation. It is well known that the spatial frequency of depth variation has a large effect on threshold. In the first experiment, we determined that the visual system compensates for this differential sensitivity when the change in disparity is suprathreshold, thereby attaining constancy similar to contrast constancy in the luminance domain. In a second experiment, we examined the ability to perceive constant depth when the spatial frequency and viewing distance both changed. To attain constancy in this situation, the visual system has to estimate distance. We investigated this ability when vergence, accommodation and vertical disparity are all presented accurately and therefore provided veridical information about viewing distance. We found that constancy is nearly complete across changes in viewing distance. Depth constancy is most complete when the scale of the depth relief is constant in the world rather than when it is constant in angular units at the retina. These results bear on the efficacy of algorithms for creating stereo content. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269596

Single-Scale Retinex Using Digital Signal Processors

NASA Technical Reports Server (NTRS)

Hines, Glenn; Rahman, Zia-Ur; Jobson, Daniel; Woodell, Glenn

2005-01-01

The Retinex is an image enhancement algorithm that improves the brightness, contrast and sharpness of an image. It performs a non-linear spatial/spectral transform that provides simultaneous dynamic range compression and color constancy. It has been used for a wide variety of applications ranging from aviation safety to general purpose photography. Many potential applications require the use of Retinex processing at video frame rates. This is difficult to achieve with general purpose processors because the algorithm contains a large number of complex computations and data transfers. In addition, many of these applications also constrain the potential architectures to embedded processors to save power, weight and cost. Thus we have focused on digital signal processors (DSPs) and field programmable gate arrays (FPGAs) as potential solutions for real-time Retinex processing. In previous efforts we attained a 21 (full) frame per second (fps) processing rate for the single-scale monochromatic Retinex with a TMS320C6711 DSP operating at 150 MHz. This was achieved after several significant code improvements and optimizations. Since then we have migrated our design to the slightly more powerful TMS320C6713 DSP and the fixed point TMS320DM642 DSP. In this paper we briefly discuss the Retinex algorithm, the performance of the algorithm executing on the TMS320C6713 and the TMS320DM642, and compare the results with the TMS320C6711.

The inconstant "principle of constancy".

PubMed

Kanzer, M

1983-01-01

A review of the principle of constancy, as it appeared in Freud's writings, shows that it was inspired by his clinical observations, first with Breuer in the field of cathartic therapy and then through experiences in the early usage of psychoanalysis. The recognition that memories repressed in the unconscious created increasing tension, and that this was relieved with dischargelike phenomena when the unconscious was made conscious, was the basis for his claim to originality in this area. The two principles of "neuronic inertia" Freud expounded in the Project (1895), are found to offer the key to the ambiguous definition of the principle of constancy he was to offer in later years. The "original" principle, which sought the complete discharge of energy (or elimination of stimuli), became the forerunner of the death drive; the "extended" principle achieved balances that were relatively constant, but succumbed in the end to complete discharge. This was the predecessor of the life drives. The relation between the constancy and pleasure-unpleasure principles was maintained for twenty-five years largely on an empirical basis which invoked the concept of psychophysical parallelism between "quantity" and "quality." As the links between the two principles were weakened by clinical experiences attendant upon the growth of ego psychology, a revision of the principle of constancy was suggested, and it was renamed the Nirvana principle. Actually it was shifted from alignment with the "extended" principle of inertia to the original, so that "constancy" was incongruously identified with self-extinction. The former basis for the constancy principle, the extended principle of inertia, became identified with Eros. Only a few commentators seem aware of this radical transformation, which has been overlooked in the Standard Edition of Freud's writings. Physiological biases in the history and conception of the principle of constancy are noted in the Standard Edition. The historical antecedents of the principle of constancy, especially in relation to the teachings and influence of J. F. Herbart (1776-1841), do much to bridge the gap between psychological and neurophysiological aspects of Freud's ideas about constancy and its associated doctrine, psychic determinism. Freud's later teachings about the Nirvana principle and Eros suggest a continuum of "constancies" embodied in the structural and functional development of the mental apparatus as it evolves from primal unity with the environment (e.g., the mother-child unit) and differentiates in patterns that organize the inner and outer worlds in relation to each other.

An Experimental Test of the Effects of Gender Constancy on Sex Typing

ERIC Educational Resources Information Center

Arthur, Andrea E.; Bigler, Rebecca S.; Ruble, Diane N.

2009-01-01

This study provides an experimental test of the hypothesis that level of gender constancy understanding affects children's sex typing. Preschool-age children (N = 62, mean age = 47 months) were randomly assigned to experimental lessons that taught that biological traits (including gender) are either fixed (pro-constancy condition) or mutable…

The Role of Gender Constancy in Early Gender Development

ERIC Educational Resources Information Center

Ruble, Diane N.; Taylor, Lisa J.; Cyphers, Lisa; Greulich, Faith K.; Lurye, Leah E.; Shrout, Patrick E.

2007-01-01

Kohlberg's (1966) hypothesis that the attainment of gender constancy motivates children to attend to gender norms was reevaluated by examining these links in relation to age. Ninety-four 3- to 7-year-old children were interviewed to assess whether and how constancy mediates age-related changes in gender-related beliefs. As expected, results…

Basic characteristics of simultaneous color contrast revisited.

PubMed

Ekroll, Vebjørn; Faul, Franz

2012-10-01

In this article, we present evidence supporting the hypothesis that the local mechanism of simultaneous color contrast is the same as the mechanism responsible for the crispening effect and the gamut expansion effect. A theoretically important corollary of this hypothesis is that the basic characteristics of simultaneous contrast are at odds with traditional laws. First, this hypothesis implies that the direction of the simultaneous contrast effect in color space is given by the vector from surround to target and not--as traditionally assumed--by the hue complementary to that of the surround. Second, it implies that the size of the simultaneous contrast effect depends on the difference between the target and surround colors in a way that challenges Kirschmann's fourth law. The widespread belief in the traditional laws, we argue, is due to the confounding influence of temporal adaptation.

Rethinking Colour Constancy

PubMed Central

Logvinenko, Alexander D.; Funt, Brian; Mirzaei, Hamidreza; Tokunaga, Rumi

2015-01-01

Colour constancy needs to be reconsidered in light of the limits imposed by metamer mismatching. Metamer mismatching refers to the fact that two objects reflecting metameric light under one illumination may reflect non-metameric light under a second; so two objects appearing as having the same colour under one illuminant can appear as having different colours under a second. Yet since Helmholtz, object colour has generally been believed to remain relatively constant. The deviations from colour constancy registered in experiments are usually thought to be small enough that they do not contradict the notion of colour constancy. However, it is important to determine how the deviations from colour constancy relate to the limits metamer mismatching imposes on constancy. Hence, we calculated metamer mismatching’s effect for the 20 Munsell papers and 8 pairs of illuminants employed in the colour constancy study by Logvinenko and Tokunaga and found it to be so extensive that the two notions—metamer mismatching and colour constancy—must be mutually exclusive. In particular, the notion of colour constancy leads to some paradoxical phenomena such as the possibility of 20 objects having the same colour under chromatic light dispersing into a hue circle of colours under neutral light. Thus, colour constancy refers to a phenomenon, which because of metamer mismatching, simply cannot exist. Moreover, it obscures the really important visual phenomenon; namely, the alteration of object colours induced by illumination change. We show that colour is not an independent, intrinsic attribute of an object, but rather an attribute of an object/light pair, and then define a concept of material colour in terms of equivalence classes of such object/light pairs. We suggest that studying the shift in material colour under a change in illuminant will be more fruitful than pursuing colour constancy’s false premise that colour is an intrinsic attribute of an object. PMID:26356217

a New Color Correction Method for Underwater Imaging

NASA Astrophysics Data System (ADS)

Bianco, G.; Muzzupappa, M.; Bruno, F.; Garcia, R.; Neumann, L.

2015-04-01

Recovering correct or at least realistic colors of underwater scenes is a very challenging issue for imaging techniques, since illumination conditions in a refractive and turbid medium as the sea are seriously altered. The need to correct colors of underwater images or videos is an important task required in all image-based applications like 3D imaging, navigation, documentation, etc. Many imaging enhancement methods have been proposed in literature for these purposes. The advantage of these methods is that they do not require the knowledge of the medium physical parameters while some image adjustments can be performed manually (as histogram stretching) or automatically by algorithms based on some criteria as suggested from computational color constancy methods. One of the most popular criterion is based on gray-world hypothesis, which assumes that the average of the captured image should be gray. An interesting application of this assumption is performed in the Ruderman opponent color space lαβ, used in a previous work for hue correction of images captured under colored light sources, which allows to separate the luminance component of the scene from its chromatic components. In this work, we present the first proposal for color correction of underwater images by using lαβ color space. In particular, the chromatic components are changed moving their distributions around the white point (white balancing) and histogram cutoff and stretching of the luminance component is performed to improve image contrast. The experimental results demonstrate the effectiveness of this method under gray-world assumption and supposing uniform illumination of the scene. Moreover, due to its low computational cost it is suitable for real-time implementation.

Effect of time spacing on the perceived color

NASA Astrophysics Data System (ADS)

Roch, Sylvain; Hardeberg, Jon Y.; Nussbaum, Peter

2007-01-01

One of latest developments for pre-press applications is the concept of soft proofing, which aims to provide an accurate preview on a monitor of how the final document will appear once it is printed. At the core of this concept is the problem of identifying, for any printed color, the most similar color the monitor can display. This problem is made difficult by such factors as varying viewing conditions, color gamut limitations, or the less studied time spacing. Color matching experiments are usually done by examining samples viewed simultaneously. However, in soft proofing applications, the proof and the print are not always viewed together. This paper attempts to shed more light on the difference between simultaneous and time-spaced color matching, in order to contribute to improving the accuracy of soft proofs. A color matching experiment setup has been established in which observers were asked to match a color patch displayed on a LCD monitor, by adjusting its RGB values, to another color patch printed out on paper. In the first part of the experiment the two colors were viewed simultaneously. In the second part, the observers were asked to produce the match according to a previously memorized color. According to the obtained results, the color appearance attributes lightness and chroma were the most difficult components for the observers to remember, generating huge differences with the simultaneous match, whereas hue was the component which varied the least. This indicates that for soft proofing, getting the hues right is of primordial importance.

The Development of Sex-Gender Constancy Among Children in Four Cultures.

ERIC Educational Resources Information Center

Munroe, Ruth H.; Munroe, Robert L.

The study examines the acquisition of gender constancy in children as it relates to cultural, socioenvironmental, or individual differences. Gender constancy refers to the stages from simple identification of biological sex of self and others, to the understanding that one's sex is stable over time, and to comprehension of one's sex as consistent…

Development of phonological constancy: 19-month-olds, but not 15-month-olds, identify words in a non-native regional accent.

PubMed

Mulak, Karen E; Best, Catherine T; Tyler, Michael D; Kitamura, Christine; Irwin, Julia R

2013-01-01

By 12 months, children grasp that a phonetic change to a word can change its identity (phonological distinctiveness). However, they must also grasp that some phonetic changes do not (phonological constancy). To test development of phonological constancy, sixteen 15-month-olds and sixteen 19-month-olds completed an eye-tracking task that tracked their gaze to named versus unnamed images for familiar words spoken in their native (Australian) and an unfamiliar non-native (Jamaican) regional accent of English. Both groups looked longer at named than unnamed images for Australian pronunciations, but only 19-month-olds did so for Jamaican pronunciations, indicating that phonological constancy emerges by 19 months. Vocabulary size predicted 15-month-olds' identifications for the Jamaican pronunciations, suggesting vocabulary growth is a viable predictor for phonological constancy development. © 2013 The Authors. Child Development © 2013 Society for Research in Child Development, Inc.

Development of phonological constancy: 19-month-olds, but not 15-month-olds, identify words in a non-native regional accent

PubMed Central

Mulak, Karen E.; Best, Catherine T.; Tyler, Michael D.; Kitamura, Christine; Irwin, Julia R.

2014-01-01

By 12 months, children grasp that a phonetic change to a word can change its identity (phonological distinctiveness). However, they must also grasp that some phonetic changes do not (phonological constancy). To test development of phonological constancy, 16 15-month-olds and 16 19-month-olds completed an eye-tracking task that tracked their gaze to named versus unnamed images for familiar words spoken in their native (Australian) and an unfamiliar non-native (Jamaican) regional accent of English. Both groups looked longer at named than unnamed images for Australian pronunciations, but only 19-month-olds did so for Jamaican pronunciations, indicating that phonological constancy emerges by 19 months. Vocabulary size predicted 15-month-olds' identifications for the Jamaican pronunciations, suggesting vocabulary growth is a viable predictor for phonological constancy development. PMID:23521607

Constancy of the relation between floc size and density in San Francisco Bay

USGS Publications Warehouse

Ganju, N.K.; Schoellhamer, D.H.; Murrell, M.C.; Gartner, J.W.; Wright, S.A.; ,

2007-01-01

The size and density of fine-sediment aggregates, or flocs, govern their transport and depositional properties. While the mass and volume concentrations of flocs can be measured directly or by optical methods, they must be determined simultaneously to gain an accurate density measurement. Results are presented from a tidal cycle study in San Francisco Bay, where mass concentration was determined directly, and volume concentration was measured in 32 logarithmically spaced size bins by laser-diffraction methods. The relation between floc size and density is investigated assuming a constant primary particle size and fractal floc dimension. This relation is validated with measurements from several sites throughout San Francisco Bay. The constancy of this relation implies a uniform primary particle size throughout the Bay, as well as uniform aggregation/disaggregation mechanisms (which modify fractal dimension). The exception to the relation is identified during near-bed measurements, when advected flocs mix with recently resuspended flocs from the bed, which typically have a higher fractal dimension than suspended flocs. The constant relation for suspended flocs simplifies monitoring and numerical modeling of suspended sediment in San Francisco Bay. ?? 2007 Elsevier B.V. All rights reserved.

Does the chromatic Mach bands effect exist?

PubMed

Tsofe, Avital; Spitzer, Hedva; Einav, Shmuel

2009-06-30

The achromatic Mach bands effect is a well-known visual illusion, discovered over a hundred years ago. This effect has been investigated thoroughly, mainly for its brightness aspect. The existence of Chromatic Mach bands, however, has been disputed. In recent years it has been reported that Chromatic Mach bands are not perceived under controlled iso-luminance conditions. However, here we show that a variety of Chromatic Mach bands, consisting of chromatic and achromatic regions, separated by a saturation ramp, can be clearly perceived under iso-luminance and iso-brightness conditions. In this study, observers' eye movements were recorded under iso-brightness conditions. Several observers were tested for their ability to perceive the Chromatic Mach bands effect and its magnitude, across different cardinal and non-cardinal Chromatic Mach bands stimuli. A computational model of color adaptation, which predicted color induction and color constancy, successfully predicts this variation of Chromatic Mach bands. This has been tested by measuring the distance of the data points from the "achromatic point" and by calculating the shift of the data points from predicted complementary lines. The results suggest that the Chromatic Mach bands effect is a specific chromatic induction effect.

Optimized Multi-Spectral Filter Array Based Imaging of Natural Scenes.

PubMed

Li, Yuqi; Majumder, Aditi; Zhang, Hao; Gopi, M

2018-04-12

Multi-spectral imaging using a camera with more than three channels is an efficient method to acquire and reconstruct spectral data and is used extensively in tasks like object recognition, relighted rendering, and color constancy. Recently developed methods are used to only guide content-dependent filter selection where the set of spectral reflectances to be recovered are known a priori. We present the first content-independent spectral imaging pipeline that allows optimal selection of multiple channels. We also present algorithms for optimal placement of the channels in the color filter array yielding an efficient demosaicing order resulting in accurate spectral recovery of natural reflectance functions. These reflectance functions have the property that their power spectrum statistically exhibits a power-law behavior. Using this property, we propose power-law based error descriptors that are minimized to optimize the imaging pipeline. We extensively verify our models and optimizations using large sets of commercially available wide-band filters to demonstrate the greater accuracy and efficiency of our multi-spectral imaging pipeline over existing methods.

Optimized Multi-Spectral Filter Array Based Imaging of Natural Scenes

PubMed Central

Li, Yuqi; Majumder, Aditi; Zhang, Hao; Gopi, M.

2018-01-01

Multi-spectral imaging using a camera with more than three channels is an efficient method to acquire and reconstruct spectral data and is used extensively in tasks like object recognition, relighted rendering, and color constancy. Recently developed methods are used to only guide content-dependent filter selection where the set of spectral reflectances to be recovered are known a priori. We present the first content-independent spectral imaging pipeline that allows optimal selection of multiple channels. We also present algorithms for optimal placement of the channels in the color filter array yielding an efficient demosaicing order resulting in accurate spectral recovery of natural reflectance functions. These reflectance functions have the property that their power spectrum statistically exhibits a power-law behavior. Using this property, we propose power-law based error descriptors that are minimized to optimize the imaging pipeline. We extensively verify our models and optimizations using large sets of commercially available wide-band filters to demonstrate the greater accuracy and efficiency of our multi-spectral imaging pipeline over existing methods. PMID:29649114

The bandwidth of consolidation into visual short-term memory (VSTM) depends on the visual feature

PubMed Central

Miller, James R.; Becker, Mark W.; Liu, Taosheng

2014-01-01

We investigated the nature of the bandwidth limit in the consolidation of visual information into visual short-term memory. In the first two experiments, we examined whether previous results showing differential consolidation bandwidth for color and orientation resulted from methodological differences by testing the consolidation of color information with methods used in prior orientation experiments. We briefly presented two color patches with masks, either sequentially or simultaneously, followed by a location cue indicating the target. Participants identified the target color via button-press (Experiment 1) or by clicking a location on a color wheel (Experiment 2). Although these methods have previously demonstrated that two orientations are consolidated in a strictly serial fashion, here we found equivalent performance in the sequential and simultaneous conditions, suggesting that two colors can be consolidated in parallel. To investigate whether this difference resulted from different consolidation mechanisms or a common mechanism with different features consuming different amounts of bandwidth, Experiment 3 presented a color patch and an oriented grating either sequentially or simultaneously. We found a lower performance in the simultaneous than the sequential condition, with orientation showing a larger impairment than color. These results suggest that consolidation of both features share common mechanisms. However, it seems that color requires less information to be encoded than orientation. As a result two colors can be consolidated in parallel without exceeding the bandwidth limit, whereas two orientations or an orientation and a color exceed the bandwidth and appear to be consolidated serially. PMID:25317065

Development of Phonological Constancy: 19-Month-Olds, but Not 15-Month-Olds, Identify Words in a Non-Native Regional Accent

ERIC Educational Resources Information Center

Mulak, Karen E.; Best, Catherine T.; Tyler, Michael D.; Kitamura, Christine; Irwin, Julia R.

2013-01-01

By 12 months, children grasp that a phonetic change to a word can change its identity ("phonological distinctiveness"). However, they must also grasp that some phonetic changes do "not" ("phonological constancy"). To test development of phonological constancy, sixteen 15-month-olds and sixteen 19-month-olds completed…

Effects of memory colour on colour constancy for unknown coloured objects

PubMed Central

Granzier, Jeroen J M; Gegenfurtner, Karl R

2012-01-01

The perception of an object's colour remains constant despite large variations in the chromaticity of the illumination—colour constancy. Hering suggested that memory colours, the typical colours of objects, could help in estimating the illuminant's colour and therefore be an important factor in establishing colour constancy. Here we test whether the presence of objects with diagnostical colours (fruits, vegetables, etc) within a scene influence colour constancy for unknown coloured objects in the scene. Subjects matched one of four Munsell papers placed in a scene illuminated under either a reddish or a greenish lamp with the Munsell book of colour illuminated by a neutral lamp. The Munsell papers were embedded in four different scenes—one scene containing diagnostically coloured objects, one scene containing incongruent coloured objects, a third scene with geometrical objects of the same colour as the diagnostically coloured objects, and one scene containing non-diagnostically coloured objects (eg, a yellow coffee mug). All objects were placed against a black background. Colour constancy was on average significantly higher for the scene containing the diagnostically coloured objects compared with the other scenes tested. We conclude that the colours of familiar objects help in obtaining colour constancy for unknown objects. PMID:23145282

Effects of memory colour on colour constancy for unknown coloured objects.

PubMed

Granzier, Jeroen J M; Gegenfurtner, Karl R

2012-01-01

The perception of an object's colour remains constant despite large variations in the chromaticity of the illumination-colour constancy. Hering suggested that memory colours, the typical colours of objects, could help in estimating the illuminant's colour and therefore be an important factor in establishing colour constancy. Here we test whether the presence of objects with diagnostical colours (fruits, vegetables, etc) within a scene influence colour constancy for unknown coloured objects in the scene. Subjects matched one of four Munsell papers placed in a scene illuminated under either a reddish or a greenish lamp with the Munsell book of colour illuminated by a neutral lamp. The Munsell papers were embedded in four different scenes-one scene containing diagnostically coloured objects, one scene containing incongruent coloured objects, a third scene with geometrical objects of the same colour as the diagnostically coloured objects, and one scene containing non-diagnostically coloured objects (eg, a yellow coffee mug). All objects were placed against a black background. Colour constancy was on average significantly higher for the scene containing the diagnostically coloured objects compared with the other scenes tested. We conclude that the colours of familiar objects help in obtaining colour constancy for unknown objects.

Chromatic illumination discrimination ability reveals that human colour constancy is optimised for blue daylight illuminations.

PubMed

Pearce, Bradley; Crichton, Stuart; Mackiewicz, Michal; Finlayson, Graham D; Hurlbert, Anya

2014-01-01

The phenomenon of colour constancy in human visual perception keeps surface colours constant, despite changes in their reflected light due to changing illumination. Although colour constancy has evolved under a constrained subset of illuminations, it is unknown whether its underlying mechanisms, thought to involve multiple components from retina to cortex, are optimised for particular environmental variations. Here we demonstrate a new method for investigating colour constancy using illumination matching in real scenes which, unlike previous methods using surface matching and simulated scenes, allows testing of multiple, real illuminations. We use real scenes consisting of solid familiar or unfamiliar objects against uniform or variegated backgrounds and compare discrimination performance for typical illuminations from the daylight chromaticity locus (approximately blue-yellow) and atypical spectra from an orthogonal locus (approximately red-green, at correlated colour temperature 6700 K), all produced in real time by a 10-channel LED illuminator. We find that discrimination of illumination changes is poorer along the daylight locus than the atypical locus, and is poorest particularly for bluer illumination changes, demonstrating conversely that surface colour constancy is best for blue daylight illuminations. Illumination discrimination is also enhanced, and therefore colour constancy diminished, for uniform backgrounds, irrespective of the object type. These results are not explained by statistical properties of the scene signal changes at the retinal level. We conclude that high-level mechanisms of colour constancy are biased for the blue daylight illuminations and variegated backgrounds to which the human visual system has typically been exposed.

The Mary Ingraham Bunting Institute of Radcliffe College.

DTIC Science & Technology

1992-08-31

scientists -- biologists Elena Budrene and Doris Stern, and geologist Constance Soja -- had also been fellows during the 1990-91 fellowship year. Beginning...Balanced Cross Sections" Constance X. Soja , Geology, Harvard University "Tectonic Controls on Reef Development During the Silurian" Doris Naimark Stern...other better-situated scholars like geologists Constance Soja and Barbara Sheffels, and molecular biologists Elena Budrene and Orna Resnekov, the

The role of gender constancy in early gender development.

PubMed

Ruble, Diane N; Taylor, Lisa J; Cyphers, Lisa; Greulich, Faith K; Lurye, Leah E; Shrout, Patrick E

2007-01-01

Kohlberg's (1966) hypothesis that the attainment of gender constancy motivates children to attend to gender norms was reevaluated by examining these links in relation to age. Ninety-four 3- to 7-year-old children were interviewed to assess whether and how constancy mediates age-related changes in gender-related beliefs. As expected, results indicated a general pattern of an increase in stereotype knowledge, the importance and positive evaluation of one's own gender category, and rigidity of beliefs between the ages of 3 and 5. Moreover, the stability phase, rather than full constancy, mediated some of these relations. After age 5, rigidity generally decreased with age, with relations primarily mediated by consistency.

Israeli Kindergarten Children's Gender Constancy for Others' Counter-Stereotypic Toy Play and Appearance: The Role of Sibling Gender and Relative Age

ERIC Educational Resources Information Center

Karniol, Rachel

2009-01-01

To test divergent theoretical predictions as to the impact of having a younger or older, same-sex sibling or opposite-sex sibling on other gender constancy, Israeli kindergarten children in two-child families responded to a gender constancy task in which a male and female picture target engaged in counter-stereotypic toy play and adopted…

Chromatic Illumination Discrimination Ability Reveals that Human Colour Constancy Is Optimised for Blue Daylight Illuminations

PubMed Central

Pearce, Bradley; Crichton, Stuart; Mackiewicz, Michal; Finlayson, Graham D.; Hurlbert, Anya

2014-01-01

The phenomenon of colour constancy in human visual perception keeps surface colours constant, despite changes in their reflected light due to changing illumination. Although colour constancy has evolved under a constrained subset of illuminations, it is unknown whether its underlying mechanisms, thought to involve multiple components from retina to cortex, are optimised for particular environmental variations. Here we demonstrate a new method for investigating colour constancy using illumination matching in real scenes which, unlike previous methods using surface matching and simulated scenes, allows testing of multiple, real illuminations. We use real scenes consisting of solid familiar or unfamiliar objects against uniform or variegated backgrounds and compare discrimination performance for typical illuminations from the daylight chromaticity locus (approximately blue-yellow) and atypical spectra from an orthogonal locus (approximately red-green, at correlated colour temperature 6700 K), all produced in real time by a 10-channel LED illuminator. We find that discrimination of illumination changes is poorer along the daylight locus than the atypical locus, and is poorest particularly for bluer illumination changes, demonstrating conversely that surface colour constancy is best for blue daylight illuminations. Illumination discrimination is also enhanced, and therefore colour constancy diminished, for uniform backgrounds, irrespective of the object type. These results are not explained by statistical properties of the scene signal changes at the retinal level. We conclude that high-level mechanisms of colour constancy are biased for the blue daylight illuminations and variegated backgrounds to which the human visual system has typically been exposed. PMID:24586299

Simultaneous image reproduction on CRT screen: Moves ultrasonic sectional view and electrocardiogram curves

NASA Technical Reports Server (NTRS)

1978-01-01

A method for simultaneous reproduction of images, requiring different amounts of time to reproduce, on a cathode ray tube (CRT) screen is disclosed. Ultrasonic sectional views and electrocardiogram curves are simultaneously reproduced on the CRT screen by producing the images on different areas of a screen with two phosphors having different persistence times and luminous colors, within the times required for the appearance of the images. In front of the area on which is produced the image requiring the shorter time is a color filter which is permeable to the color of the phosphor with the shorter persistence time by which absorbs the color of the other phosphor.

Competition in saccade target selection reveals attentional guidance by simultaneously active working memory representations.

PubMed

Beck, Valerie M; Hollingworth, Andrew

2017-02-01

The content of visual working memory (VWM) guides attention, but whether this interaction is limited to a single VWM representation or functional for multiple VWM representations is under debate. To test this issue, we developed a gaze-contingent search paradigm to directly manipulate selection history and examine the competition between multiple cue-matching saccade target objects. Participants first saw a dual-color cue followed by two pairs of colored objects presented sequentially. For each pair, participants selectively fixated an object that matched one of the cued colors. Critically, for the second pair, the cued color from the first pair was presented either with a new distractor color or with the second cued color. In the latter case, if two cued colors in VWM interact with selection simultaneously, we expected the second cued color object to generate substantial competition for selection, even though the first cued color was used to guide attention in the immediately previous pair. Indeed, in the second pair, selection probability of the first cued color was substantially reduced in the presence of the second cued color. This competition between cue-matching objects provides strong evidence that both VWM representations interacted simultaneously with selection. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Simultaneous contrast and gamut relativity in achromatic color perception.

PubMed

Vladusich, Tony

2012-09-15

Simultaneous contrast refers to the respective whitening or blackening of physically identical image regions surrounded by regions of low or high luminance, respectively. A common method of measuring the strength of this effect is achromatic color matching, in which subjects adjust the luminance of a target region to achieve an achromatic color match with another region. Here I present psychophysical data questioning the assumption--built into many models of achromatic color perception--that achromatic colors are represented as points in a one-dimensional (1D) perceptual space, or an absolute achromatic color gamut. I present an alternative model in which the achromatic color gamut corresponding to a target region is defined relatively, with respect to surround luminance. Different achromatic color gamuts in this model correspond to different 1D lines through a 2D perceptual space composed of blackness and whiteness dimensions. Each such line represents a unique gamut of achromatic colors ranging from black to white. I term this concept gamut relativity. Achromatic color matches made between targets surrounded by regions of different luminance are shown to reflect the relative perceptual distances between points lying on different gamut lines. The model suggests a novel geometrical approach to simultaneous contrast and achromatic color matching in terms of the vector summation of local luminance and contrast components, and sets the stage for a unified computational theory of achromatic color perception. 2012 Elsevier Ltd. All rights reserved

Proprioceptive Distance Cues Restore Perfect Size Constancy in Grasping, but Not Perception, When Vision Is Limited.

PubMed

Chen, Juan; Sperandio, Irene; Goodale, Melvyn Alan

2018-03-19

Our brain integrates information from multiple modalities in the control of behavior. When information from one sensory source is compromised, information from another source can compensate for the loss. What is not clear is whether the nature of this multisensory integration and the re-weighting of different sources of sensory information are the same across different control systems. Here, we investigated whether proprioceptive distance information (position sense of body parts) can compensate for the loss of visual distance cues that support size constancy in perception (mediated by the ventral visual stream) [1, 2] versus size constancy in grasping (mediated by the dorsal visual stream) [3-6], in which the real-world size of an object is computed despite changes in viewing distance. We found that there was perfect size constancy in both perception and grasping in a full-viewing condition (lights on, binocular viewing) and that size constancy in both tasks was dramatically disrupted in the restricted-viewing condition (lights off; monocular viewing of the same but luminescent object through a 1-mm pinhole). Importantly, in the restricted-viewing condition, proprioceptive cues about viewing distance originating from the non-grasping limb (experiment 1) or the inclination of the torso and/or the elbow angle of the grasping limb (experiment 2) compensated for the loss of visual distance cues to enable a complete restoration of size constancy in grasping but only a modest improvement of size constancy in perception. This suggests that the weighting of different sources of sensory information varies as a function of the control system being used. Copyright © 2018 Elsevier Ltd. All rights reserved.

Detecting and accounting for violations of the constancy assumption in non-inferiority clinical trials.

PubMed

Koopmeiners, Joseph S; Hobbs, Brian P

2018-05-01

Randomized, placebo-controlled clinical trials are the gold standard for evaluating a novel therapeutic agent. In some instances, it may not be considered ethical or desirable to complete a placebo-controlled clinical trial and, instead, the placebo is replaced by an active comparator with the objective of showing either superiority or non-inferiority to the active comparator. In a non-inferiority trial, the experimental treatment is considered non-inferior if it retains a pre-specified proportion of the effect of the active comparator as represented by the non-inferiority margin. A key assumption required for valid inference in the non-inferiority setting is the constancy assumption, which requires that the effect of the active comparator in the non-inferiority trial is consistent with the effect that was observed in previous trials. It has been shown that violations of the constancy assumption can result in a dramatic increase in the rate of incorrectly concluding non-inferiority in the presence of ineffective or even harmful treatment. In this paper, we illustrate how Bayesian hierarchical modeling can be used to facilitate multi-source smoothing of the data from the current trial with the data from historical studies, enabling direct probabilistic evaluation of the constancy assumption. We then show how this result can be used to adapt the non-inferiority margin when the constancy assumption is violated and present simulation results illustrating that our method controls the type-I error rate when the constancy assumption is violated, while retaining the power of the standard approach when the constancy assumption holds. We illustrate our adaptive procedure using a non-inferiority trial of raltegravir, an antiretroviral drug for the treatment of HIV.

Detecting and Accounting for Violations of the Constancy Assumption in Non-Inferiority Clinical Trials

PubMed Central

Koopmeiners, Joseph S.; Hobbs, Brian P.

2016-01-01

Randomized, placebo-controlled clinical trials are the gold standard for evaluating a novel therapeutic agent. In some instances, it may not be considered ethical or desirable to complete a placebo-controlled clinical trial and, instead, the placebo is replaced by an active comparator (AC) with the objective of showing either superiority or non-inferiority to the AC. In a non-inferiority trial, the experimental treatment is considered non-inferior if it retains a pre-specified proportion of the effect of the AC as represented by the non-inferiority margin. A key assumption required for valid inference in the non-inferiority setting is the constancy assumption, which requires that the effect of the AC in the non-inferiority trial is consistent with the effect that was observed in previous trials. It has been shown that violations of the constancy assumption can result in a dramatic increase in the rate of incorrectly concluding non-inferiority in the presence of ineffective or even harmful treatment. In this paper, we illustrate how Bayesian hierarchical modeling can be used to facilitate multi-source smoothing of the data from the current trial with the data from historical studies, enabling direct probabilistic evaluation of the constancy assumption. We then show how this result can be used to adapt the non-inferiority margin when the constancy assumption is violated and present simulation results illustrating that our method controls the type-I error rate when the constancy assumption is violated, while retaining the power of the standard approach when the constancy assumption holds. We illustrate our adaptive procedure using a non-inferiority trial of raltegravir, an antiretroviral drug for the treatment of HIV. PMID:27587591

Spatial constancy mechanisms in motor control

PubMed Central

Medendorp, W. Pieter

2011-01-01

The success of the human species in interacting with the environment depends on the ability to maintain spatial stability despite the continuous changes in sensory and motor inputs owing to movements of eyes, head and body. In this paper, I will review recent advances in the understanding of how the brain deals with the dynamic flow of sensory and motor information in order to maintain spatial constancy of movement goals. The first part summarizes studies in the saccadic system, showing that spatial constancy is governed by a dynamic feed-forward process, by gaze-centred remapping of target representations in anticipation of and across eye movements. The subsequent sections relate to other oculomotor behaviour, such as eye–head gaze shifts, smooth pursuit and vergence eye movements, and their implications for feed-forward mechanisms for spatial constancy. Work that studied the geometric complexities in spatial constancy and saccadic guidance across head and body movements, distinguishing between self-generated and passively induced motion, indicates that both feed-forward and sensory feedback processing play a role in spatial updating of movement goals. The paper ends with a discussion of the behavioural mechanisms of spatial constancy for arm motor control and their physiological implications for the brain. Taken together, the emerging picture is that the brain computes an evolving representation of three-dimensional action space, whose internal metric is updated in a nonlinear way, by optimally integrating noisy and ambiguous afferent and efferent signals. PMID:21242137

Stanford/NASA-Ames Center of Excellence in model-based human performance

NASA Technical Reports Server (NTRS)

Wandell, Brian A.

1990-01-01

The human operator plays a critical role in many aeronautic and astronautic missions. The Stanford/NASA-Ames Center of Excellence in Model-Based Human Performance (COE) was initiated in 1985 to further our understanding of the performance capabilities and performance limits of the human component of aeronautic and astronautic projects. Support from the COE is devoted to those areas of experimental and theoretical work designed to summarize and explain human performance by developing computable performance models. The ultimate goal is to make these computable models available to other scientists for use in design and evaluation of aeronautic and astronautic instrumentation. Within vision science, two topics have received particular attention. First, researchers did extensive work analyzing the human ability to recognize object color relatively independent of the spectral power distribution of the ambient lighting (color constancy). The COE has supported a number of research papers in this area, as well as the development of a substantial data base of surface reflectance functions, ambient illumination functions, and an associated software package for rendering and analyzing image data with respect to these spectral functions. Second, the COE supported new empirical studies on the problem of selecting colors for visual display equipment to enhance human performance in discrimination and recognition tasks.

Smart light random memory sprays Retinex: a fast Retinex implementation for high-quality brightness adjustment and color correction.

PubMed

Banić, Nikola; Lončarić, Sven

2015-11-01

Removing the influence of illumination on image colors and adjusting the brightness across the scene are important image enhancement problems. This is achieved by applying adequate color constancy and brightness adjustment methods. One of the earliest models to deal with both of these problems was the Retinex theory. Some of the Retinex implementations tend to give high-quality results by performing local operations, but they are computationally relatively slow. One of the recent Retinex implementations is light random sprays Retinex (LRSR). In this paper, a new method is proposed for brightness adjustment and color correction that overcomes the main disadvantages of LRSR. There are three main contributions of this paper. First, a concept of memory sprays is proposed to reduce the number of LRSR's per-pixel operations to a constant regardless of the parameter values, thereby enabling a fast Retinex-based local image enhancement. Second, an effective remapping of image intensities is proposed that results in significantly higher quality. Third, the problem of LRSR's halo effect is significantly reduced by using an alternative illumination processing method. The proposed method enables a fast Retinex-based image enhancement by processing Retinex paths in a constant number of steps regardless of the path size. Due to the halo effect removal and remapping of the resulting intensities, the method outperforms many of the well-known image enhancement methods in terms of resulting image quality. The results are presented and discussed. It is shown that the proposed method outperforms most of the tested methods in terms of image brightness adjustment, color correction, and computational speed.

Propagation characteristics of two-color laser pulses in homogeneous plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hemlata,; Saroch, Akanksha; Jha, Pallavi

2015-11-15

An analytical and numerical study of the evolution of two-color, sinusoidal laser pulses in cold, underdense, and homogeneous plasma has been presented. The wave equations for the radiation fields driven by linear as well as nonlinear contributions due to the two-color laser pulses have been set up. A variational technique is used to obtain the simultaneous equations describing the evolution of the laser spot size, pulse length, and chirp parameter. Numerical methods are used to graphically analyze the simultaneous evolution of these parameters due to the combined effect of the two-color laser pulses. Further, the pulse parameters are compared withmore » those obtained for a single laser pulse. Significant focusing, compression, and enhanced positive chirp is obtained due to the combined effect of simultaneously propagating two-color pulses as compared to a single pulse propagating in plasma.« less

A blind human expert echolocator shows size constancy for objects perceived by echoes.

PubMed

Milne, Jennifer L; Anello, Mimma; Goodale, Melvyn A; Thaler, Lore

2015-01-01

Some blind humans make clicking noises with their mouth and use the reflected echoes to perceive objects and surfaces. This technique can operate as a crude substitute for vision, allowing human echolocators to perceive silent, distal objects. Here, we tested if echolocation would, like vision, show size constancy. To investigate this, we asked a blind expert echolocator (EE) to echolocate objects of different physical sizes presented at different distances. The EE consistently identified the true physical size of the objects independent of distance. In contrast, blind and blindfolded sighted controls did not show size constancy, even when encouraged to use mouth clicks, claps, or other signals. These findings suggest that size constancy is not a purely visual phenomenon, but that it can operate via an auditory-based substitute for vision, such as human echolocation.

[Physician from Constance doctor of medicine Georg Vogelin (1508-1542), an early follower of Copernicus].

PubMed

Burmeister, K H

1999-01-01

Georg Vogelin was born in Constance as the son of the town clerk. He studied the artes liberales and medicine at Wittenberg (since 1523) and Montpellier (since 1527). From 1531 onwards he practiced as a medical doctor in Constance. In 1542 Vogelin died of the plague in Constance. Vogelin was very close friends with the medical doctor Achilles Pirmin Gasser (1505-1577) and Georg Joachim Rheticus (1514-1574), a well known pupil of Copernicus. He was amongst the first supporters of the teachings of Copernicus. Gasser, who published the second edition of Rheticus' "Narratio prima" (Basle 1541), dedicated this edition to Georg Vogelin. In this book Vogelin published a poem in Latin. In the poem he described the teachings of Copernicus ("Terraque iam currit, credita stare prius") and recommended the academic community to approve Copernicus' theory.

Storage ring two-color free-electron laser

DOE PAGES

Yan, J.; Hao, H.; Li, J. Y.; ...

2016-07-05

We report a systematic experimental study of a storage ring two-color free-electron laser (FEL) operating simultaneously in the infrared (IR) and ultraviolet (UV) wavelength regions. The two-color FEL lasing has been realized using a pair of dual-band high-reflectivity FEL mirrors with two different undulator configurations. We have demonstrated independent wavelength tuning in a wide range for each lasing color, as well as harmonically locked wavelength tuning when the UV lasing occurs at the second harmonic of the IR lasing. Precise power control of two-color lasing with good power stability has also been achieved. In addition, the impact of the degradationmore » of FEL mirrors on the two-color FEL operation is reported. Moreover, we have investigated the temporal structures of the two-color FEL beams, showing simultaneous two-color micropulses with their intensity modulations displayed as FEL macropulses.« less

Size constancy in bat biosonar? Perceptual interaction of object aperture and distance.

PubMed

Heinrich, Melina; Wiegrebe, Lutz

2013-01-01

Perception and encoding of object size is an important feature of sensory systems. In the visual system object size is encoded by the visual angle (visual aperture) on the retina, but the aperture depends on the distance of the object. As object distance is not unambiguously encoded in the visual system, higher computational mechanisms are needed. This phenomenon is termed "size constancy". It is assumed to reflect an automatic re-scaling of visual aperture with perceived object distance. Recently, it was found that in echolocating bats, the 'sonar aperture', i.e., the range of angles from which sound is reflected from an object back to the bat, is unambiguously perceived and neurally encoded. Moreover, it is well known that object distance is accurately perceived and explicitly encoded in bat sonar. Here, we addressed size constancy in bat biosonar, recruiting virtual-object techniques. Bats of the species Phyllostomus discolor learned to discriminate two simple virtual objects that only differed in sonar aperture. Upon successful discrimination, test trials were randomly interspersed using virtual objects that differed in both aperture and distance. It was tested whether the bats spontaneously assigned absolute width information to these objects by combining distance and aperture. The results showed that while the isolated perceptual cues encoding object width, aperture, and distance were all perceptually well resolved by the bats, the animals did not assign absolute width information to the test objects. This lack of sonar size constancy may result from the bats relying on different modalities to extract size information at different distances. Alternatively, it is conceivable that familiarity with a behaviorally relevant, conspicuous object is required for sonar size constancy, as it has been argued for visual size constancy. Based on the current data, it appears that size constancy is not necessarily an essential feature of sonar perception in bats.

Parts Color Matching Scanner for Edge Gluing - Research That Works

Treesearch

Richard W. Conners; D.Earl Kline; Philip A. Araman

1996-01-01

This paper presents an automatic color sorting system for hardwood edge-glued panel parts. The color sorting system simultaneously examines both faces of a panel part and then determines which face has the "best" color given specified color uniformity and priority defined by management. The real-time color sorting system hardware and color matching hardware...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, J.; Hao, H.; Li, J. Y.

We report a systematic experimental study of a storage ring two-color free-electron laser (FEL) operating simultaneously in the infrared (IR) and ultraviolet (UV) wavelength regions. The two-color FEL lasing has been realized using a pair of dual-band high-reflectivity FEL mirrors with two different undulator configurations. We have demonstrated independent wavelength tuning in a wide range for each lasing color, as well as harmonically locked wavelength tuning when the UV lasing occurs at the second harmonic of the IR lasing. Precise power control of two-color lasing with good power stability has also been achieved. In addition, the impact of the degradationmore » of FEL mirrors on the two-color FEL operation is reported. Moreover, we have investigated the temporal structures of the two-color FEL beams, showing simultaneous two-color micropulses with their intensity modulations displayed as FEL macropulses.« less

Orthogonal Relations and Color Constancy in Dichromatic Colorblindness

PubMed Central

Pridmore, Ralph W.

2014-01-01

This paper employs uniform color space to analyze relations in dichromacy (protanopia, deuteranopia, tritanopia). Fifty percent or less of dichromats represent the classical reduction form of trichromacy, where one of three cones is inoperative but normal trichromatic color mixture such as complementary colors (pairs that mix white) are accepted by the dichromat, whose data can thus be plotted to CIE chromaticity spaces. The remaining dichromats comprise many and varied more-complex gene arrays from mutations, recombinations, etc. Though perhaps a minority, the three reductionist types provide a simple standard, in genotype and phenotype, to which the more complex remainder may be compared. Here, previously published data on dichromacy are plotted and analyzed in CIELUV uniform color space to find spatial relations in terms of color appearance space (e.g., hue angle). Traditional residual (seen) hues for protanopia and deuteranopia (both red–green colorblindness) are yellow and blue, but analysis indicates the protanopic residual hues are more greenish yellow and reddish blue than in tradition. Results for three illuminants (D65, D50, B) imply four principles in the spatial structure of dichromacy: (1) complementarity of confusion hue pairs and of residual hue pairs; (2) orthogonality of confusion locus and residual hues locus at their intersection with the white point, in each dichromatic type; (3) orthogonality of protanopic and tritanopic confusion loci; and (4) inverse relations between protanopic and tritanopic systems generally, such that one's confusion hues are the other's residual hues. Two of the three dichromatic systems do not represent components of normal trichromatic vision as sometimes thought but are quite different. Wavelength shifts between illuminants demonstrate chromatic adaptation correlates exactly with that in trichromatic vision. In theory these results clarify relations in and between types of dichromacy. They also apply in Munsell and CIELAB color spaces but inexactly to the degree they employ inexact complementarity. PMID:25211128

Orthogonal relations and color constancy in dichromatic colorblindness.

PubMed

Pridmore, Ralph W

2014-01-01

This paper employs uniform color space to analyze relations in dichromacy (protanopia, deuteranopia, tritanopia). Fifty percent or less of dichromats represent the classical reduction form of trichromacy, where one of three cones is inoperative but normal trichromatic color mixture such as complementary colors (pairs that mix white) are accepted by the dichromat, whose data can thus be plotted to CIE chromaticity spaces. The remaining dichromats comprise many and varied more-complex gene arrays from mutations, recombinations, etc. Though perhaps a minority, the three reductionist types provide a simple standard, in genotype and phenotype, to which the more complex remainder may be compared. Here, previously published data on dichromacy are plotted and analyzed in CIELUV uniform color space to find spatial relations in terms of color appearance space (e.g., hue angle). Traditional residual (seen) hues for protanopia and deuteranopia (both red-green colorblindness) are yellow and blue, but analysis indicates the protanopic residual hues are more greenish yellow and reddish blue than in tradition. Results for three illuminants (D65, D50, B) imply four principles in the spatial structure of dichromacy: (1) complementarity of confusion hue pairs and of residual hue pairs; (2) orthogonality of confusion locus and residual hues locus at their intersection with the white point, in each dichromatic type; (3) orthogonality of protanopic and tritanopic confusion loci; and (4) inverse relations between protanopic and tritanopic systems generally, such that one's confusion hues are the other's residual hues. Two of the three dichromatic systems do not represent components of normal trichromatic vision as sometimes thought but are quite different. Wavelength shifts between illuminants demonstrate chromatic adaptation correlates exactly with that in trichromatic vision. In theory these results clarify relations in and between types of dichromacy. They also apply in Munsell and CIELAB color spaces but inexactly to the degree they employ inexact complementarity.

Machine Vision System for Color Sorting Wood Edge-Glued Panel Parts

Treesearch

Qiang Lu; S. Srikanteswara; W. King; T. Drayer; Richard Conners; D. Earl Kline; Philip A. Araman

1997-01-01

This paper describes an automatic color sorting system for hardwood edge-glued panel parts. The color sorting system simultaneously examines both faces of a panel part and then determines which face has the "better" color given specified color uniformity and priority defined by management. The real-time color sorting system software and hardware are briefly...

Lake Constance

Atmospheric Science Data Center

2013-04-17

... the left-hand side of the image is bordered by Switzerland, Germany, and Austria, and has several names. Lake Constance (also written as ... is about 70 kilometers from the lakeside town of Konstanz, Germany. An annual Celtic music festival is hosted on the Swiss shores of Lake ...

Spatial and temporal aspects of chromatic adaptation and their functional significance for colour constancy.

PubMed

Werner, Annette

2014-11-01

Illumination in natural scenes changes at multiple temporal and spatial scales: slow changes in global illumination occur in the course of a day, and we encounter fast and localised illumination changes when visually exploring the non-uniform light field of three-dimensional scenes; in addition, very long-term chromatic variations may come from the environment, like for example seasonal changes. In this context, I consider the temporal and spatial properties of chromatic adaptation and discuss their functional significance for colour constancy in three-dimensional scenes. A process of fast spatial tuning in chromatic adaptation is proposed as a possible sensory mechanism for linking colour constancy to the spatial structure of a scene. The observed middlewavelength selectivity of this process is particularly suitable for adaptation to the mean chromaticity and the compensation of interreflections in natural scenes. Two types of sensory colour constancy are distinguished, based on the functional differences of their temporal and spatial scales: a slow type, operating at a global scale for the compensation of the ambient illumination; and a fast colour constancy, which is locally restricted and well suited to compensate region-specific variations in the light field of three dimensional scenes. Copyright © 2014 Elsevier B.V. All rights reserved.

Dimming-discrete-multi-tone (DMT) for simultaneous color control and high speed visible light communication.

PubMed

Sung, Jiun-Yu; Chow, Chi-Wai; Yeh, Chien-Hung

2014-04-07

Visible light communication (VLC) using LEDs has attracted significant attention recently for the future secure, license-free and electromagnetic-interference (EMI)-free optical wireless communication. Dimming technique in LED lamp is advantageous for energy efficiency. Color control can be performed in the red-green-blue (RGB) LEDs by using dimming technique. It is highly desirable to employ dimming technique to provide simultaneous color and dimming control and high speed VLC. Here, we proposed and demonstrated a LED dimming control using dimming-discrete-multi-tone (DMT) modulation. High speed DMT-based VLC with simultaneous color and dimming control is demonstrated for the first time to the best of our knowledge. Demonstration and analyses for several modulation conditions and transmission distances are performed, for instance, demonstrating the data rate of 103.5 Mb/s (using RGB LED) with fast Fourier transform (FFT) size of 512.

Gender Constancy and the Effects of Sex-typed Televised Toy Commercials.

ERIC Educational Resources Information Center

Ruble, Diane N.; And Others

1981-01-01

Presents a cognitive-developmental analysis of the effects of televised, sex-stereotypic information on children's behavior and attitudes towards toy play. Subjects were 100 children, ages four to six divided into groups exhibiting high and low gender-constancy. (Author/CM)

Mystery #2 Answer

Atmospheric Science Data Center

2013-04-22

... D.   A lakeside town hosts an annual celebration of Celtic music. Answer: B is false Lake Constance provides drinking water for ... lakeside town of   Konstanz, Germany. An annual Celtic music festival is hosted on the Swiss shores of Lake Constance at the town of ...

Infrared actuation-induced simultaneous reconfiguration of surface color and morphology for soft robotics.

PubMed

Banisadr, Seyedali; Chen, Jian

2017-12-13

Cephalopods, such as cuttlefish, demonstrate remarkable adaptability to the coloration and texture of their surroundings by modulating their skin color and surface morphology simultaneously, for the purpose of adaptive camouflage and signal communication. Inspired by this unique feature of cuttlefish skins, we present a general approach to remote-controlled, smart films that undergo simultaneous changes of surface color and morphology upon infrared (IR) actuation. The smart film has a reconfigurable laminated structure that comprises an IR-responsive nanocomposite actuator layer and a mechanochromic elastomeric photonic crystal layer. Upon global or localized IR irradiation, the actuator layer exhibits fast, large, and reversible strain in the irradiated region, which causes a synergistically coupled change in the shape of the laminated film and color of the mechanochromic elastomeric photonic crystal layer in the same region. Bending and twisting deformations can be created under IR irradiation, through modulating the strain direction in the actuator layer of the laminated film. Furthermore, the laminated film has been used in a remote-controlled inchworm walker that can directly couple a color-changing skin with the robotic movements. Such remote-controlled, smart films may open up new application possibilities in soft robotics and wearable devices.

3D simulation of the influence of internal mixing dynamics on the propagation of river plumes in Lake Constance

NASA Astrophysics Data System (ADS)

Pflugbeil, Thomas; Pöschke, Franziska; Noffke, Anna; Winde, Vera; Wolf, Thomas

2017-04-01

Lake Constance is one of most important drinking water resources in southern Germany. Furthermore, the lake and its catchment is a meaningful natural habitat as well as economical and cultural area. In this context, sustainable development and conservation of the lake ecosystem and drinking water quality is of high importance. However, anthropogenic pressures (e.g. waste water, land use, industry in catchment area) on the lake itself and its external inflows are high. The project "SeeZeichen" (ReWaM-project cluster by BMBF, funding number 02WRM1365) is investigating different immission pathways (groundwater, river, superficial inputs) and their impact on the water quality of Lake Constance. The investigation includes the direct inflow areas as well as the lake-wide context. The present simulation study investigates the mixing dynamics of Lake Constance and its impacts on river inflows and vice versa. It considers different seasonal (mixing and stratification periods), hydrological (flood events, average and low discharge) and transport conditions (sediment loads). The simulations are focused on two rivers: The River Alpenrhein delivers about 60 % of water and material input into Lake Constance. The River Schussen was chosen since it is highly anthropogenic influenced. For this purpose, a high-resolution three-dimensional hydrodynamic model of the Lake Constance is set up with Delft3D-Flow model system. The model is calibrated and validated with long term data sets of water levels, discharges and temperatures. The model results will be analysed for residence times of river water within the lake and particle distributions to evaluate potential impacts of river plume water constituents on the general water quality of the lake.

Chemical reactivation of resin-embedded pHuji adds red for simultaneous two-color imaging with EGFP

PubMed Central

Guo, Wenyan; Liu, Xiuli; Liu, Yurong; Gang, Yadong; He, Xiaobin; Jia, Yao; Yin, Fangfang; Li, Pei; Huang, Fei; Zhou, Hongfu; Wang, Xiaojun; Gong, Hui; Luo, Qingming; Xu, Fuqiang; Zeng, Shaoqun

2017-01-01

The pH-sensitive fluorescent proteins enabling chemical reactivation in resin are useful tools for fluorescence microimaging. EGFP or EYFP is good for such applications. For simultaneous two-color imaging, a suitable red fluorescent protein is an urgent need. Here a pH-sensitive red fluorescent protein, pHuji, is selected and verified to remain pH-sensitive in HM20 resin. We observe 183% fluorescence intensity of pHuji in resin-embeded mouse brain and 29.08-fold fluorescence intensity of reactivated pHuji compared to the quenched state. pHuji and EGFP can be quenched and chemically reactivated simultaneously in resin, thus enabling simultaneous two-color micro-optical sectioning tomography of resin-embedded mouse brain. This method may greatly facilitate the visualization of neuronal morphology and neural circuits to promote understanding of the structure and function of the brain. PMID:28717566

Chemical reactivation of resin-embedded pHuji adds red for simultaneous two-color imaging with EGFP.

PubMed

Guo, Wenyan; Liu, Xiuli; Liu, Yurong; Gang, Yadong; He, Xiaobin; Jia, Yao; Yin, Fangfang; Li, Pei; Huang, Fei; Zhou, Hongfu; Wang, Xiaojun; Gong, Hui; Luo, Qingming; Xu, Fuqiang; Zeng, Shaoqun

2017-07-01

The pH-sensitive fluorescent proteins enabling chemical reactivation in resin are useful tools for fluorescence microimaging. EGFP or EYFP is good for such applications. For simultaneous two-color imaging, a suitable red fluorescent protein is an urgent need. Here a pH-sensitive red fluorescent protein, pHuji, is selected and verified to remain pH-sensitive in HM20 resin. We observe 183% fluorescence intensity of pHuji in resin-embeded mouse brain and 29.08-fold fluorescence intensity of reactivated pHuji compared to the quenched state. pHuji and EGFP can be quenched and chemically reactivated simultaneously in resin, thus enabling simultaneous two-color micro-optical sectioning tomography of resin-embedded mouse brain. This method may greatly facilitate the visualization of neuronal morphology and neural circuits to promote understanding of the structure and function of the brain.

Development of Phonological Constancy

PubMed Central

Best, Catherine T.; Tyler, Michael D.; Gooding, Tiffany N.; Orlando, Corey B.; Quann, Chelsea A.

2009-01-01

Efficient word recognition depends on detecting critical phonetic differences among similar-sounding words, or sensitivity to phonological distinctiveness, an ability evident at 19 months of age but unreliable at 14 to 15 months of age. However, little is known about phonological constancy, the equally crucial ability to recognize a word's identity across natural phonetic variations, such as those in cross-dialect pronunciation differences. We show that 15- and 19-month-old children recognize familiar words spoken in their native dialect, but that only the older children recognize familiar words in a dissimilar nonnative dialect, providing evidence for emergence of phonological constancy by 19 months. These results are compatible with a perceptual-attunement account of developmental change in early word recognition, but not with statistical-learning or phonological accounts. Thus, the complementary skills of phonological constancy and distinctiveness both appear at around 19 months of age, together providing the child with a fundamental insight that permits rapid vocabulary growth and later reading acquisition. PMID:19368700

Evolution, Development and Function of Vertebrate Cone Oil Droplets

PubMed Central

Toomey, Matthew B.; Corbo, Joseph C.

2017-01-01

To distinguish colors, the nervous system must compare the activity of distinct subtypes of photoreceptors that are maximally sensitive to different portions of the light spectrum. In vertebrates, a variety of adaptations have arisen to refine the spectral sensitivity of cone photoreceptors and improve color vision. In this review article, we focus on one such adaptation, the oil droplet, a unique optical organelle found within the inner segment of cone photoreceptors of a diverse array of vertebrate species, from fish to mammals. These droplets, which consist of neutral lipids and carotenoid pigments, are interposed in the path of light through the photoreceptor and modify the intensity and spectrum of light reaching the photosensitive outer segment. In the course of evolution, the optical function of oil droplets has been fine-tuned through changes in carotenoid content. Species active in dim light reduce or eliminate carotenoids to enhance sensitivity, whereas species active in bright light precisely modulate carotenoid double bond conjugation and concentration among cone subtypes to optimize color discrimination and color constancy. Cone oil droplets have sparked the curiosity of vision scientists for more than a century. Accordingly, we begin by briefly reviewing the history of research on oil droplets. We then discuss what is known about the developmental origins of oil droplets. Next, we describe recent advances in understanding the function of oil droplets based on biochemical and optical analyses. Finally, we survey the occurrence and properties of oil droplets across the diversity of vertebrate species and discuss what these patterns indicate about the evolutionary history and function of this intriguing organelle. PMID:29276475

Optimization of Ocean Color Algorithms: Application to Satellite Data Merging

NASA Technical Reports Server (NTRS)

Maritorena, Stephane; Siegel, David A.; Morel, Andre

2003-01-01

The objective of our program is to develop and validate a procedure for ocean color data merging which is one of the major goals of the SIMBIOS project. The need for a merging capability is dictated by the fact that since the launch of MODIS on the Terra platform and over the next decade, several global ocean color missions from various space agencies are or will be operational simultaneously. The apparent redundancy in simultaneous ocean color missions can actually be exploited to various benefits. The most obvious benefit is improved coverage. The patchy and uneven daily coverage from any single sensor can be improved by using a combination of sensors. Beside improved coverage of the global Ocean the merging of Ocean color data should also result in new, improved, more diverse and better data products with lower uncertainties. Ultimately, ocean color data merging should result in the development of a unified, scientific quality, ocean color time series, from SeaWiFS to NPOESS and beyond. Various approaches can be used for ocean color data merging and several have been tested within the frame of the SIMBIOS program. As part of the SIMBIOS Program, we have developed a merging method for ocean color data. Conversely to other methods our approach does not combine end-products like the subsurface chlorophyll concentration (chl) from different sensors to generate a unified product. Instead, our procedure uses the normalized water-leaving radiances (L(sub WN)(lambda)) from single or multiple sensors and uses them in the inversion of a semi-analytical ocean color model that allows the retrieval of several ocean color variables simultaneously. Beside ensuring simultaneity and consistency of the retrievals (all products are derived from a single algorithm), this model-based approach has various benefits over techniques that blend end-products (e.g. chlorophyll): 1) it works with single or multiple data sources regardless of their specific bands, 2) it exploits band redundancies and band differences, 3) it accounts for uncertainties in the (L(sub WN)(lambda)) data and, 4) it provides uncertainty estimates for the retrieved variables.

Universal Trade-Off between Power, Efficiency, and Constancy in Steady-State Heat Engines

NASA Astrophysics Data System (ADS)

Pietzonka, Patrick; Seifert, Udo

2018-05-01

Heat engines should ideally have large power output, operate close to Carnot efficiency and show constancy, i.e., exhibit only small fluctuations in this output. For steady-state heat engines, driven by a constant temperature difference between the two heat baths, we prove that out of these three requirements only two are compatible. Constancy enters quantitatively the conventional trade-off between power and efficiency. Thus, we rationalize and unify recent suggestions for overcoming this simple trade-off. Our universal bound is illustrated for a paradigmatic model of a quantum dot solar cell and for a Brownian gyrator delivering mechanical work against an external force.

Simultaneous Determination of Acetaminophen and Synthetic Color(s) by Derivative Spectroscopy in Syrup Formulations and Validation by HPLC: Exposure Risk of Colors to Children.

PubMed

Rastogi, Shanya Das; Dixit, Sumita; Tripathi, Anurag; Das, Mukul

2015-06-01

Color additives are used in pediatric syrup formulations as an excipient; though not pre-requisite, but pediatric syrup formulations are normally colored. An attempt has been made to measure simultaneously the single drug, acetaminophen (AT), along with the colors, carmoisine (CA), erythrosine (ET), and sunset yellow FCF (SSY) added in it by three derivative spectroscopy methods namely, 1st order, ratio, and differential derivative methods. Moreover, evaluation has been made for the exposure assessment of the colors added as excipient because some colors have been reported to cause allergic reactions and hypersensitivity in children. The present methods provide simple, accurate, and reproducible quantitative determination of the drug, AT, along with the color in synthetic mixtures and commercial drug formulations without any interference. The limit of detection varied from 0.0001-0.31 μg/ml while limit of quantification ranged from 0.002-1.04 μg/ml in all the three methods. The calibration curve of all the three derivative methods exhibited good linear relationship with excellent regression coefficients (0.9986-1.000). Both intra-day and inter-day precisions showed %RSD value less than 2% while the percentage recovery was found between 96.8-103.8%. The sensitivity of the proposed methods is almost comparable to HPLC and thus, can be used for determination of drug AT, and color simultaneously in pharmaceutical formulation on routine basis. The present methods also showed that colors like SSY and ET are saturating more than 50% of acceptable daily intake (ADI) value which is alarming and needs to be considered for modification by regulatory authorities to safeguard the health of children.

Colors, humors and evil eye: indigenous classification and treatment of childhood diarrhea in highland Guatemala.

PubMed

Burleigh, E; Dardano, C; Cruz, J R

1990-11-01

Focal group interviews on indigenous perceptions and reported management of childhood diarrhea were conducted in 1987-88 in Guatemala as a part of a prospective epidemiological field study of chronic diarrhea. Six cognitive schemata were identified, each with specific causes, a linked progression of concepts, symptoms, signs, and diagnostic characteristics. Nearly all were related to the humoral theory of disease, including the concept of evil eye. Diarrheal disease was conceptualized in the village as a set of processes which could be either "hot" or "cold" rather than as an unchanging single-symptom entity occupying only one spot on the humoral continuum. Clarification of the temporal relationship between concepts was found to be essential to the understanding of these indigenously-defined schemata. Stool color reflecting humoral theory was the primary concept used in household-level diagnosis. Reported behavior associated with these cognitive schemata (traditional treatments, pharmaceutical and dietary management) showed remarkable constancy, and adhered for the most part to the humoral concept of equilibrium. These included the use of oral rehydration solutions (ORS) and liquids. The applied importance of humoral theory to home-based use of ORS is discussed briefly as is the indigenous definition of dehydration.

Constance Mellon's "Library Anxiety": An Appreciation and a Critique

ERIC Educational Resources Information Center

Gremmels, Gillian S.

2015-01-01

In this article, the author recollects her memories reading Constance A. Mellon's article, "Library Anxiety: A Grounded Theory and Its Development," when it appeared in the March 1986 issue of "College & Research Libraries." She was a reference librarian at at DePauw University in Indiana at the time, helping students…

Simultaneous detection of multiple DNA targets by integrating dual-color graphene quantum dot nanoprobes and carbon nanotubes.

PubMed

Qian, Zhaosheng; Shan, Xiaoyue; Chai, Lujing; Chen, Jianrong; Feng, Hui

2014-12-01

Simultaneous detection of multiple DNA targets was achieved based on a biocompatible graphene quantum dots (GQDs) and carbon nanotubes (CNTs) platform through spontaneous assembly between dual-color GQD-based probes and CNTs and subsequently self-recognition between DNA probes and targets. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design and characterization of an optimized simultaneous color and near-infrared fluorescence rigid endoscopic imaging system

NASA Astrophysics Data System (ADS)

Venugopal, Vivek; Park, Minho; Ashitate, Yoshitomo; Neacsu, Florin; Kettenring, Frank; Frangioni, John V.; Gangadharan, Sidhu P.; Gioux, Sylvain

2013-12-01

We report the design, characterization, and validation of an optimized simultaneous color and near-infrared (NIR) fluorescence rigid endoscopic imaging system for minimally invasive surgery. This system is optimized for illumination and collection of NIR wavelengths allowing the simultaneous acquisition of both color and NIR fluorescence at frame rates higher than 6.8 fps with high sensitivity. The system employs a custom 10-mm diameter rigid endoscope optimized for NIR transmission. A dual-channel light source compatible with the constraints of an endoscope was built and includes a plasma source for white light illumination and NIR laser diodes for fluorescence excitation. A prism-based 2-CCD camera was customized for simultaneous color and NIR detection with a highly efficient filtration scheme for fluorescence imaging of both 700- and 800-nm emission dyes. The performance characterization studies indicate that the endoscope can efficiently detect fluorescence signal from both indocyanine green and methylene blue in dimethyl sulfoxide at the concentrations of 100 to 185 nM depending on the background optical properties. Finally, we performed the validation of this imaging system in vivo during a minimally invasive procedure for thoracic sentinel lymph node mapping in a porcine model.

Automatic Color Sorting of Hardwood Edge-Glued Panel Parts

Treesearch

D. Earl Kline; Richard Conners; Qiang Lu; Philip A. Araman

1997-01-01

This paper describes an automatic color sorting system for red oak edge-glued panel parts. The color sorting system simultaneously examines both faces of a panel part and then determines which face has the "best" color, and sorts the part into one of a number of color classes at plant production speeds. Initial test results show that the system generated over...

Demosaiced pixel super-resolution for multiplexed holographic color imaging

PubMed Central

Wu, Yichen; Zhang, Yibo; Luo, Wei; Ozcan, Aydogan

2016-01-01

To synthesize a holographic color image, one can sequentially take three holograms at different wavelengths, e.g., at red (R), green (G) and blue (B) parts of the spectrum, and digitally merge them. To speed up the imaging process by a factor of three, a Bayer color sensor-chip can also be used to demultiplex three wavelengths that simultaneously illuminate the sample and digitally retrieve individual set of holograms using the known transmission spectra of the Bayer color filters. However, because the pixels of different channels (R, G, B) on a Bayer color sensor are not at the same physical location, conventional demosaicing techniques generate color artifacts in holographic imaging using simultaneous multi-wavelength illumination. Here we demonstrate that pixel super-resolution can be merged into the color de-multiplexing process to significantly suppress the artifacts in wavelength-multiplexed holographic color imaging. This new approach, termed Demosaiced Pixel Super-Resolution (D-PSR), generates color images that are similar in performance to sequential illumination at three wavelengths, and therefore improves the speed of holographic color imaging by 3-fold. D-PSR method is broadly applicable to holographic microscopy applications, where high-resolution imaging and multi-wavelength illumination are desired. PMID:27353242

Genetically distinct colour morphs of European perch Perca fluviatilis in Lake Constance differ in susceptibility to macroparasites.

PubMed

Roch, S; Behrmann-Godel, J; Brinker, A

2015-01-21

The unusual yellow-finned morph of European perch Perca fluviatilis found in Lake Constance suffers more severely from macroparasite infections, including the tapeworm Triaenophorus nodulosus and the gill worm Ancyrocephalus percae, than conspecifics elsewhere. Microsatellite analysis of yellow-finned P. fluviatilis and red-finned variant recently discovered in Lake Constance revealed significant genetic differentiation. Red-finned P. fluviatilis and fish with mixed fin colour, suggested backcrosses between red and yellow-finned colour morphs, exhibit better resilience to parasite infection, suggesting that the inability of the yellow-finned morph to reject macroparasites may have a genetic basis. © 2015 The Fisheries Society of the British Isles.

All set, indeed! N2pc components reveal simultaneous attentional control settings for multiple target colors.

PubMed

Grubert, Anna; Eimer, Martin

2016-08-01

To study whether top-down attentional control processes can be set simultaneously for different visual features, we employed a spatial cueing procedure to measure behavioral and electrophysiological markers of task-set contingent attentional capture during search for targets defined by 1 or 2 possible colors (one-color and two-color tasks). Search arrays were preceded by spatially nonpredictive color singleton cues. Behavioral spatial cueing effects indicative of attentional capture were elicited only by target-matching but not by distractor-color cues. However, when search displays contained 1 target-color and 1 distractor-color object among gray nontargets, N2pc components were triggered not only by target-color but also by distractor-color cues both in the one-color and two-color task, demonstrating that task-set nonmatching items attracted attention. When search displays contained 6 items in 6 different colors, so that participants had to adopt a fully feature-specific task set, the N2pc to distractor-color cues was eliminated in both tasks, indicating that nonmatching items were now successfully excluded from attentional processing. These results demonstrate that when observers adopt a feature-specific search mode, attentional task sets can be configured flexibly for multiple features within the same dimension, resulting in the rapid allocation of attention to task-set matching objects only. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Young Teachers' Attitudes towards School and Their Change towards Conservatism on Entering the Profession--A Reply.

ERIC Educational Resources Information Center

Cloetta, Bernhard; And Others

1987-01-01

Reviews criticisms of the Constance research project on the shift towards conservatism in young teachers' attitudes. Concludes that Hansel's 1985 criticism remains speculative and empirically unsound, and that De Brabander's (1987) theoretical approach does not produce an adequate critique of the Constance questionnaire on teachers' attitudes…

Revisiting the Principle of Relative Constancy: Consumer Mass Media Expenditures in Belgium.

ERIC Educational Resources Information Center

Dupagne, Michel; Green, R. Jeffery

1996-01-01

Proposes two new econometric models for testing the principle of relative constancy (PRC). Reports on regression and cointegration analyses conducted with Belgian mass media expenditure data from 1953-91. Suggests that alternative mass media expenditure models should be developed because PRC lacks of economic foundation and sound empirical…

Constance D'Arcy Mackay: A Historiographical Perspective.

ERIC Educational Resources Information Center

van de Water, Manon

1995-01-01

States that Constance D'Arcy Mackay was instrumental in defining the genre of children's theater in the early 20th century. Discusses her career highlights. Concludes that Mackay played a pivotal role in the "making" of the history of children's theater in the United States, and that while little of her personal history is known, her…

The Relationship among Localization Skill, Existence Constancy and Object Permanence.

ERIC Educational Resources Information Center

Townes-Rosenwein, Linda

Two component skills of object permanence were studied: existence constancy -- the infants' ability to expect that an object continues to exist after it is hidden, and localization skill -- infants' ability to search in the correct place for a hidden object. Contradictions within the literature may occur because of task lability caused by failure…

CONSTANCY OF THE RELATION BETWEEN FLOC SIZE AND DENSITY IN SAN FRANCISCO BAY

EPA Science Inventory

Ganju, N.K., D.H. Schoellhamer, M.C. Murrell, J.W. Gartner and S.A. Wright. In press. Constancy of the Relation Between Floc Size and Density in San Francisco Bay. In: INTERCOH 2003: Proceedings of the 7th International Conference on Nearshore and Estuarine Cohesive Sediment Tran...

Pollen Load and Flower Constancy of Three Species of Stingless Bees (Hymenoptera, Apidae, Meliponinae)

PubMed Central

Pangestika, Norita Widya; Atmowidi, Tri; Kahono, Sih

2017-01-01

The genera of stingless bees play an important role as pollinators of plants. These bees are actively involved in the pollination of agricultural crops and known to have preferences in selecting flowers to pollinate. The aims of this study were to analyse the pollen load and flower constancy in Tetragonula laeviceps, Lepidotrigona terminata, and Heterotrigona itama. Each individual of species stingless bees collected and was put in a 1.5 mL micro-tube contain 0.5 mL 70% ethanol:glycerol (4:1). Pollen loads on each individual of stingless bees was counted by hemocytometer. Flower constancy of stingless bees was measured based on percentage of pollen type loaded on the body. Results showed that the pollen loads of H. itama was the highest (31392 pollen grains) followed by L. terminata (23017 pollen grains) and T. laeviceps (8015 pollen grains). These species also demonstrated different flower constancy, T. laeviceps on Poaceae flowers (76.49%), L. terminata on Euphorbiaceae flowers (80.46%), and H. itama on Solanaceae flowers (83.33%). PMID:28890769

Automated Algorithm to Detect Changes in Geostationary Satellites Configuration and Cross-Tagging

DTIC Science & Technology

2015-10-18

Color Photometry Catalog (GCPC) and Geo Observations with Latitudinal Diversity Simultaneously ( GOLDS ) data sets are used to simulate configuration...stabilized geostationary satellites in the Geostationary Observations with Latitudinal Diversity Simultaneously ( GOLDS ) and GEO satellite Color...107.3o W. The GOLDS campaign was conducted in two phases, both lead by AFRL’s Space Vehicles Directorate with the participation of a consortium

Loss of 3-D shape constancy in interior spaces: the basis of the Ames-room illusion.

PubMed

Dorward, F M; Day, R H

1997-01-01

The apparently rectangular form of the irregularly shaped Ames room is explained in terms of a loss of interior 3-D shape constancy consequent on viewing the room with one eye through a small specifically positioned aperture. In the absence of retinal disparity and motion parallax the appearance of the room is held to shift markedly toward the rectangular dimensions of its retinal image. Three experiments designed to test this explanation with a miniature (one-tenth size) version of the Ames room No 1 with the matched 2-D shape of the back wall and as an index of interior 3-D shape are reported. The experiments showed that interior constancy was almost fully restored with binocular viewing of the room (experiment 1). The effect with a 'skeletal' version of the room was about the same as that with the conventional version and was clearly evident when the back wall or its frame version was presented alone (experiment 2), and it varied according to whether the interior perspective corresponded with that of the Ames or a rectangular room (experiment 3). Experiment 3 also showed that a rectangular room is significantly distorted when the interior perspective accords with that of the Ames room. These outcomes are construed as supporting the loss-of-constancy explanation and as showing that the Ames-room effect is one of a class of illusions attributable to the absence of stimulus correlates that normally sustain visual shape constancy.

Technology to sort lumber by color and grain for furniture parts

Treesearch

D. Earl Kline; Richard Conners; Philip A. Araman

2000-01-01

This paper describes an automatic color and grain sorting system for wood edge-glued panel parts. The color sorting system simultaneously examines both faces of a panel part and then determines which face has the "best" color, and sorts the part into one of a number of color classes at plant production speeds. In-plant test results show that the system...

Size Constancy in Bat Biosonar? Perceptual Interaction of Object Aperture and Distance

PubMed Central

Heinrich, Melina; Wiegrebe, Lutz

2013-01-01

Perception and encoding of object size is an important feature of sensory systems. In the visual system object size is encoded by the visual angle (visual aperture) on the retina, but the aperture depends on the distance of the object. As object distance is not unambiguously encoded in the visual system, higher computational mechanisms are needed. This phenomenon is termed “size constancy”. It is assumed to reflect an automatic re-scaling of visual aperture with perceived object distance. Recently, it was found that in echolocating bats, the ‘sonar aperture’, i.e., the range of angles from which sound is reflected from an object back to the bat, is unambiguously perceived and neurally encoded. Moreover, it is well known that object distance is accurately perceived and explicitly encoded in bat sonar. Here, we addressed size constancy in bat biosonar, recruiting virtual-object techniques. Bats of the species Phyllostomus discolor learned to discriminate two simple virtual objects that only differed in sonar aperture. Upon successful discrimination, test trials were randomly interspersed using virtual objects that differed in both aperture and distance. It was tested whether the bats spontaneously assigned absolute width information to these objects by combining distance and aperture. The results showed that while the isolated perceptual cues encoding object width, aperture, and distance were all perceptually well resolved by the bats, the animals did not assign absolute width information to the test objects. This lack of sonar size constancy may result from the bats relying on different modalities to extract size information at different distances. Alternatively, it is conceivable that familiarity with a behaviorally relevant, conspicuous object is required for sonar size constancy, as it has been argued for visual size constancy. Based on the current data, it appears that size constancy is not necessarily an essential feature of sonar perception in bats. PMID:23630598

Color correction with blind image restoration based on multiple images using a low-rank model

NASA Astrophysics Data System (ADS)

Li, Dong; Xie, Xudong; Lam, Kin-Man

2014-03-01

We present a method that can handle the color correction of multiple photographs with blind image restoration simultaneously and automatically. We prove that the local colors of a set of images of the same scene exhibit the low-rank property locally both before and after a color-correction operation. This property allows us to correct all kinds of errors in an image under a low-rank matrix model without particular priors or assumptions. The possible errors may be caused by changes of viewpoint, large illumination variations, gross pixel corruptions, partial occlusions, etc. Furthermore, a new iterative soft-segmentation method is proposed for local color transfer using color influence maps. Due to the fact that the correct color information and the spatial information of images can be recovered using the low-rank model, more precise color correction and many other image-restoration tasks-including image denoising, image deblurring, and gray-scale image colorizing-can be performed simultaneously. Experiments have verified that our method can achieve consistent and promising results on uncontrolled real photographs acquired from the Internet and that it outperforms current state-of-the-art methods.

Blindness to a simultaneous change of all elements in a scene, unless there is a change in summary statistics.

PubMed

Saiki, Jun; Holcombe, Alex O

2012-03-06

Sudden change of every object in a display is typically conspicuous. We find however that in the presence of a secondary task, with a display of moving dots, it can be difficult to detect a sudden change in color of all the dots. A field of 200 dots, half red and half green, half moving rightward and half moving leftward, gave the appearance of two surfaces. When all 200 dots simultaneously switched color between red and green, performance in detecting the switch was very poor. A key display characteristic was that the color proportions on each surface (summary statistics) were not affected by the color switch. When the color switch is accompanied by a change in these summary statistics, people perform well in detecting the switch, suggesting that the secondary task does not disrupt the availability of this statistical information. These findings suggest that when the change is missed, the old and new colors were represented, but the color-location pattern (binding of colors to locations) was not represented or not compared. Even after extended viewing, changes to the individual color-location pattern are not available, suggesting that the feeling of seeing these details is misleading.

Optimized universal color palette design for error diffusion

NASA Astrophysics Data System (ADS)

Kolpatzik, Bernd W.; Bouman, Charles A.

1995-04-01

Currently, many low-cost computers can only simultaneously display a palette of 256 color. However, this palette is usually selectable from a very large gamut of available colors. For many applications, this limited palette size imposes a significant constraint on the achievable image quality. We propose a method for designing an optimized universal color palette for use with halftoning methods such as error diffusion. The advantage of a universal color palette is that it is fixed and therefore allows multiple images to be displayed simultaneously. To design the palette, we employ a new vector quantization method known as sequential scalar quantization (SSQ) to allocate the colors in a visually uniform color space. The SSQ method achieves near-optimal allocation, but may be efficiently implemented using a series of lookup tables. When used with error diffusion, SSQ adds little computational overhead and may be used to minimize the visual error in an opponent color coordinate system. We compare the performance of the optimized algorithm to standard error diffusion by evaluating a visually weighted mean-squared-error measure. Our metric is based on the color difference in CIE L*AL*B*, but also accounts for the lowpass characteristic of human contrast sensitivity.

Optimization Of Ocean Color Algorithms: Application To Satellite And In Situ Data Merging. Chapter 9

NASA Technical Reports Server (NTRS)

Maritorena, Stephane; Siegel, David A.; Morel, Andre

2003-01-01

The objective of our program is to develop and validate a procedure for ocean color data merging which is one of the major goals of the SIMBIOS project (McClain et al., 1995). The need for a merging capability is dictated by the fact that since the launch of MODIS on the Terra platform and over the next decade, several global ocean color missions from various space agencies are or will be operational simultaneously. The apparent redundancy in simultaneous ocean color missions can actually be exploited to various benefits. The most obvious benefit is improved coverage (Gregg et al., 1998; Gregg & Woodward, 1998). The patchy and uneven daily coverage from any single sensor can be improved by using a combination of sensors. Beside improved coverage of the global ocean the merging of ocean color data should also result in new, improved, more diverse and better data products with lower uncertainties. Ultimately, ocean color data merging should result in the development of a unified, scientific quality, ocean color time series, from SeaWiFS to NPOESS and beyond. Various approaches can be used for ocean color data merging and several have been tested within the frame of the SIMBIOS program (see e.g. Kwiatkowska & Fargion, 2003, Franz et al., 2003). As part of the SIMBIOS Program, we have developed a merging method for ocean color data. Conversely to other methods our approach does not combine end-products like the subsurface chlorophyll concentration (chl) from different sensors to generate a unified product. Instead, our procedure uses the normalized waterleaving radiances (LwN( )) from single or multiple sensors and uses them in the inversion of a semianalytical ocean color model that allows the retrieval of several ocean color variables simultaneously. Beside ensuring simultaneity and consistency of the retrievals (all products are derived from a single algorithm), this model-based approach has various benefits over techniques that blend end-products (e.g. chlorophyll): 1) it works with single or multiple data sources regardless of their specific bands, 2) it exploits band redundancies and band differences, 3) it accounts for uncertainties in the LwN( ) data and, 4) it provides uncertainty estimates for the retrieved variables.

Joint estimation of motion and illumination change in a sequence of images

NASA Astrophysics Data System (ADS)

Koo, Ja-Keoung; Kim, Hyo-Hun; Hong, Byung-Woo

2015-09-01

We present an algorithm that simultaneously computes optical flow and estimates illumination change from an image sequence in a unified framework. We propose an energy functional consisting of conventional optical flow energy based on Horn-Schunck method and an additional constraint that is designed to compensate for illumination changes. Any undesirable illumination change that occurs in the imaging procedure in a sequence while the optical flow is being computed is considered a nuisance factor. In contrast to the conventional optical flow algorithm based on Horn-Schunck functional, which assumes the brightness constancy constraint, our algorithm is shown to be robust with respect to temporal illumination changes in the computation of optical flows. An efficient conjugate gradient descent technique is used in the optimization procedure as a numerical scheme. The experimental results obtained from the Middlebury benchmark dataset demonstrate the robustness and the effectiveness of our algorithm. In addition, comparative analysis of our algorithm and Horn-Schunck algorithm is performed on the additional test dataset that is constructed by applying a variety of synthetic bias fields to the original image sequences in the Middlebury benchmark dataset in order to demonstrate that our algorithm outperforms the Horn-Schunck algorithm. The superior performance of the proposed method is observed in terms of both qualitative visualizations and quantitative accuracy errors when compared to Horn-Schunck optical flow algorithm that easily yields poor results in the presence of small illumination changes leading to violation of the brightness constancy constraint.

What predicts the strength of simultaneous color contrast?

PubMed Central

Ratnasingam, Sivalogeswaran; Anderson, Barton L.

2017-01-01

The perceived color of a uniform image patch depends not only on the spectral content of the light that reaches the eye but also on its context. One of the most extensively studied forms of context dependence is a simultaneous contrast display: a center-surround display containing a homogeneous target embedded in a homogenous surround. A number of models have been proposed to account for the chromatic transformations of targets induced by such surrounds, but they were typically derived in the restricted context of experiments using achromatic targets with surrounds that varied along the cardinal axes of color space. There is currently no theoretical consensus that predicts the target color that produces the largest perceived color difference for two arbitrarily chosen surround colors, or what surround would give the largest color induction for an arbitrarily chosen target. Here, we present a method for assessing simultaneous contrast that avoids some of the methodological issues that arise with nulling and matching experiments and diminishes the contribution of temporal adaption. Observers were presented with pairs of center-surround patterns and ordered them from largest to smallest in perceived dissimilarity. We find that the perceived difference for two arbitrarily chosen surrounds is largest when the target falls on the line connecting the two surrounds in color space. We also find that the magnitude of induction is larger for larger differences between chromatic targets and surrounds of the same hue. Our results are consistent with the direction law (Ekroll & Faul, 2012b), and with a generalization of Kirschmann's fourth law, even for viewing conditions that do not favor temporal adaptation. PMID:28245494

Using the Dual-Target Cost to Explore the Nature of Search Target Representations

ERIC Educational Resources Information Center

Stroud, Michael J.; Menneer, Tamaryn; Cave, Kyle R.; Donnelly, Nick

2012-01-01

Eye movements were monitored to examine search efficiency and infer how color is mentally represented to guide search for multiple targets. Observers located a single color target very efficiently by fixating colors similar to the target. However, simultaneous search for 2 colors produced a dual-target cost. In addition, as the similarity between…

Gender Constancy and the "Cost" of Sex-Typed Behavior: A Test of the Conflict Hypothesis.

ERIC Educational Resources Information Center

Frey, Karin S.; Ruble, Diane N.

1992-01-01

Children between 5 and 10 years of age watched boys and girls endorse toys of varying attractiveness and then play with the toys. Boys with gender constancy spent more time than other boys in playing with unattractive sex-typed toys. Among girls, toy play was related to the toy's attractiveness. (BC)

Messages for Educational Leadership: The Constance E. Clayton Lectures 1998-2007. Black Studies and Critical Thinking. Volume 34

ERIC Educational Resources Information Center

Slaughter-Defoe, Diana T., Ed.

2012-01-01

Urban education is an interdisciplinary field, characterized by introducing many perspectives to research pertaining to educational policy and to the practice of educating youth whose lives unfold in densely populated urban metropolitan areas. This book celebrates Constance Clayton's eleven-year tenure as superintendent of the School District of…

Constance "Connie" Hanf (1917-2002): The Mentor and the Model

ERIC Educational Resources Information Center

Reitman, David; McMahon, Robert J.

2013-01-01

This article provides an account of the impact of Constance Hanf, Ph.D., developer of the well-known two-stage parent training model that bears her name. Past colleagues, interns, postdoctoral students, and undergraduate trainees reflect on their experiences with Dr. Hanf and comment on her influence on their careers, as well as the impact of the…

The Relation between Gender Labelling and Gender Constancy in Preschool Children.

ERIC Educational Resources Information Center

Zucker, Kenneth J.; Yoannidis, Tom

The relationship between preschool children's level of gender understanding and their ability to identify gender-linked attributes was examined. Participants were 26 3-year-old and 30 4-year-old children who were administered a single-cue gender labelling task, Slaby and Frey's (1975) gender constancy test, and the Peabody Picture Vocabulary Test.…

Simultaneous Multi-Filter Optical Photometry of GEO Debris

NASA Technical Reports Server (NTRS)

Seitzer, Patrick; Cowardin, Heather; Barker, Edwin S.; Abercromby, Kira; Kelecy, Thomas

2011-01-01

Information on the physical characteristics of unresolved pieces of debris comes from an object's brightness, and how it changes with time and wavelength. True colors of tumbling, irregularly shaped objects can be accurately determined only if the intensity at all wavelengths is measured at the same time. In this paper we report on simultaneous photometric observations of objects at geosynchronous orbit (GEO) using two telescopes at Cerro Tololo Inter-American Observatory (CTIO). The CTIO/SMARTS 0.9-m observes in a Johnson B filter, while the 0.6-m MODEST (Michigan Orbital DEbris Survey Telescope) observes in a Cousins R filter. The two CCD cameras are electronically synchronized so that the exposure start time and duration are the same for both telescopes. Thus we obtain the brightness as a function of time in two passbands simultaneously, and can determine the true color of the object at any time. We will report here on such calibrated measurements made on a sample of GEO objects and what is the distribution of the observed B-R colors. In addition, using this data set, we will show what colors would be observed if the observations in different filters were obtained sequentially, as would be the case for conventional imaging observations with a single detector on a single telescope. Finally, we will compare our calibrated colors of GEO debris with colors determined in the laboratory of selected materials actually used in spacecraft construction.

DSP Implementation of the Retinex Image Enhancement Algorithm

NASA Technical Reports Server (NTRS)

Hines, Glenn; Rahman, Zia-Ur; Jobson, Daniel; Woodell, Glenn

2004-01-01

The Retinex is a general-purpose image enhancement algorithm that is used to produce good visual representations of scenes. It performs a non-linear spatial/spectral transform that synthesizes strong local contrast enhancement and color constancy. A real-time, video frame rate implementation of the Retinex is required to meet the needs of various potential users. Retinex processing contains a relatively large number of complex computations, thus to achieve real-time performance using current technologies requires specialized hardware and software. In this paper we discuss the design and development of a digital signal processor (DSP) implementation of the Retinex. The target processor is a Texas Instruments TMS320C6711 floating point DSP. NTSC video is captured using a dedicated frame-grabber card, Retinex processed, and displayed on a standard monitor. We discuss the optimizations used to achieve real-time performance of the Retinex and also describe our future plans on using alternative architectures.

Asteroid observations and planetary atmospheres analysis

NASA Technical Reports Server (NTRS)

Baum, W. A.; Millis, R. L.; Bowell, E. L. G.

1975-01-01

Photoelectric observations of Eros and 30 other asteroids providing information on their surface characteristics, shape, and rotation axes are reported. Photographs of 18 asteroids and 4 comets yielding accurate position information on various dates were obtained. Photometric observations were made of the Saturn satellite lapetus, and electronographic images of the Uranus and Neptune satellites were obtained experimentally with a Spectracon tube to assess photometry by that method. Planetary patrol photographs of Venus and deconvolved area scans of Uranus were taken. UBV photometry of the Galilean satellites for the period 1973-1974 was completely analyzed and accepted for publication. An improved magnitude and color index for Minas were derived from 1974 area scans. A special photomultiplier tube with a suppressor grid was incorporated into a pulse-counting photometer with special added circuitry for carrying out the observations concerning the constancy of solar system dimensions over cosmic time.

Developing a machine vision system for simultaneous prediction of freshness indicators based on tilapia (Oreochromis niloticus) pupil and gill color during storage at 4°C.

PubMed

Shi, Ce; Qian, Jianping; Han, Shuai; Fan, Beilei; Yang, Xinting; Wu, Xiaoming

2018-03-15

The study assessed the feasibility of developing a machine vision system based on pupil and gill color changes in tilapia for simultaneous prediction of total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA) and total viable counts (TVC) during storage at 4°C. The pupils and gills were chosen and color space conversion among RGB, HSI and L ∗ a ∗ b ∗ color spaces was performed automatically by an image processing algorithm. Multiple regression models were established by correlating pupil and gill color parameters with TVB-N, TVC and TBA (R 2 =0.989-0.999). However, assessment of freshness based on gill color is destructive and time-consuming because gill cover must be removed before images are captured. Finally, visualization maps of spoilage based on pupil color were achieved using image algorithms. The results show that assessment of tilapia pupil color parameters using machine vision can be used as a low-cost, on-line method for predicting freshness during 4°C storage. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficient Colorful Perovskite Solar Cells Using a Top Polymer Electrode Simultaneously as Spectrally Selective Antireflection Coating.

PubMed

Jiang, Youyu; Luo, Bangwu; Jiang, Fangyuan; Jiang, Fuben; Fuentes-Hernandez, Canek; Liu, Tiefeng; Mao, Lin; Xiong, Sixing; Li, Zaifang; Wang, Tao; Kippelen, Bernard; Zhou, Yinhua

2016-12-14

Organometal halide perovskites have shown excellent optoelectronic properties and have been used to demonstrate a variety of semiconductor devices. Colorful solar cells are desirable for photovoltaic integration in buildings and other aesthetically appealing applications. However, the realization of colorful perovskite solar cells is challenging because of their broad and large absorption coefficient that commonly leads to cells with dark-brown colors. Herein, for the first time, we report a simple and efficient strategy to achieve colorful perovskite solar cells by using the transparent conducting polymer (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), PEDOT:PSS) as a top electrode and simultaneously as an spectrally selective antireflection coating. Vivid colors across the visible spectrum are attained by engineering optical interference effects among the transparent PEDOT:PSS polymer electrode, the hole-transporting layer and the perovskite layer. The colored perovskite solar cells display power conversion efficiency values from 12.8 to 15.1% (from red to blue) when illuminated from the FTO glass side and from 11.6 to 13.8% (from red to blue) when illuminated from the PEDOT:PSS side. The new approach provides an advanced solution for fabricating colorful perovskite solar cells with easy processing and high efficiency.

Right Temporal Cortex is Critical for Utilization of Melodic Contextual Cues in a Pitch Constancy Task

ERIC Educational Resources Information Center

Warrier, Catherine M.; Zatorre, Robert J.

2004-01-01

Pitch constancy, perceiving the same pitch from tones with differing spectral shapes, requires one to extract the fundamental frequency from two sets of harmonics and compare them. We previously showed this difficult task to be easier when tonal context is present, presumably because the context creates a tonal reference point from which to judge…

Detection of IMRT delivery errors based on a simple constancy check of transit dose by using an EPID

NASA Astrophysics Data System (ADS)

Baek, Tae Seong; Chung, Eun Ji; Son, Jaeman; Yoon, Myonggeun

2015-11-01

Beam delivery errors during intensity modulated radiotherapy (IMRT) were detected based on a simple constancy check of the transit dose by using an electronic portal imaging device (EPID). Twenty-one IMRT plans were selected from various treatment sites, and the transit doses during treatment were measured by using an EPID. Transit doses were measured 11 times for each course of treatment, and the constancy check was based on gamma index (3%/3 mm) comparisons between a reference dose map (the first measured transit dose) and test dose maps (the following ten measured dose maps). In a simulation using an anthropomorphic phantom, the average passing rate of the tested transit dose was 100% for three representative treatment sites (head & neck, chest, and pelvis), indicating that IMRT was highly constant for normal beam delivery. The average passing rate of the transit dose for 1224 IMRT fields from 21 actual patients was 97.6% ± 2.5%, with the lower rate possibly being due to inaccuracies of patient positioning or anatomic changes. An EPIDbased simple constancy check may provide information about IMRT beam delivery errors during treatment.

Filling in the retinal image

NASA Technical Reports Server (NTRS)

Larimer, James; Piantanida, Thomas

1990-01-01

The optics of the eye form an image on a surface at the back of the eyeball called the retina. The retina contains the photoreceptors that sample the image and convert it into a neural signal. The spacing of the photoreceptors in the retina is not uniform and varies with retinal locus. The central retinal field, called the macula, is densely packed with photoreceptors. The packing density falls off rapidly as a function of retinal eccentricity with respect to the macular region and there are regions in which there are no photoreceptors at all. The retinal regions without photoreceptors are called blind spots or scotomas. The neural transformations which convert retinal image signals into percepts fills in the gaps and regularizes the inhomogeneities of the retinal photoreceptor sampling mosaic. The filling-in mechamism plays an important role in understanding visual performance. The filling-in mechanism is not well understood. A systematic collaborative research program at the Ames Research Center and SRI in Menlo Park, California, was designed to explore this mechanism. It was shown that the perceived fields which are in fact different from the image on the retina due to filling-in, control some aspects of performance and not others. Researchers have linked these mechanisms to putative mechanisms of color coding and color constancy.

Anionic Photopolymerization of Methyl-2-Cyanoacrylate and Simultaneous Color Formation

DTIC Science & Technology

2000-11-15

Anionic polymerization of methyl 2-cyanoacrylate initiated by photoinduced heterolysis of crystal violet leuconitrile (CVCN) and of malachite green leucohydroxide (MGOH) is demonstrated. Polymerization is accompanied by color formation.

Interracial Contact and Racial Constancy: A Multi-Site Study of Racial Intergroup Bias in 3-5 Year Old Anglo-British Children

ERIC Educational Resources Information Center

Rutland, Adam; Cameron, Lindsey; Bennett, Laura; Ferrell, Jennifer

2005-01-01

This paper examined the influence of interracial contact and racial constancy on the racial intergroup bias of young Anglo-British children. This multi-site study was conducted in areas of Great Britain that varied in terms of racial diversity. The study also investigated whether preschool children express bias on positive, but not negative,…

Moral and Legal Issues Surrounding Terminal Sedation and Physician Assisted Suicide

DTIC Science & Technology

2002-09-23

1 MORAL AND LEGAL ISSUES SURROUNDING TERMINAL SEDATION AND PHYSICIAN ASSISTED SUICIDE by CONSTANCE ReJENNA BRADLEY B.S., United States Air Force...Title and Subtitle Moral and Legal Issues Surrounding Terminal Sedation and Physician-Assisted Suicide Contract Number Grant Number Program...Constance ReJenna (M.A., Philosophy) Moral and Legal Issues Surrounding Terminal Sedation and Physician Assisted Suicide Thesis directed by Instructor

The Principle of Relativity and the Indeterminacy of Special Relativity

ERIC Educational Resources Information Center

de Abreu, Rodrigo; Guerra, Vasco

2008-01-01

This work ends a trilogy devoted to a journey into the foundations of special relativity. The first paper debated the meaning of the constancy of the two-way speed of light and its close relation to the conceptualization of time. The second one addressed the question of the possible constancy of the one-way speed of light and the trivial--but,…

Incubation behavior of king eiders on the coastal plain of Northern Alaska

USGS Publications Warehouse

Bentzen, R.L.; Powell, A.N.; Phillips, Laura M.; Suydam, R.S.

2010-01-01

Incubating birds balance their energetic demands during incubation with the needs of the developing embryos. Incubation behavior is correlated with body size; larger birds can accumulate more endogenous reserves and maintain higher incubation constancy. King eiders (Somateria spectabilis) contend with variable and cold spring weather, little nesting cover, and low food availability, and thus are likely to rely heavily on endogenous reserves to maintain high incubation constancy. We examined the patterns of nest attendance of king eiders at Teshekpuk and Kuparuk, Alaska (2002-2005) in relation to clutch size, daily temperature, and endogenous reserves to explore factors controlling incubation behavior. Females at Kuparuk had higher constancy (98.5 ?? 0.2%, n = 30) than at Teshekpuk (96.9 ?? 0.8%, n = 26), largely due to length of recesses. Mean recess length ranged from 21.5 to 23.7 min at Kuparuk, and from 28.5 to 51.2 min at Teshekpuk. Mean body mass on arrival at breeding grounds (range; Teshekpuk 1,541-1,805, Kuparuk 1,616-1,760), and at the end of incubation (Teshekpuk 1,113-1,174, Kuparuk 1,173-1,183), did not vary between sites or among years (F < 1.1, P > 0.3). Daily constancy increased 1% with every 5??C increase in minimum daily temperature (??min = 0.005, 95% CI 0.002, 0.009). Higher constancy combined with similar mass loss at Kuparuk implies that females there met foraging requirements with shorter recesses. Additionally, females took more recesses at low temperatures, suggesting increased maintenance needs which were potentially ameliorated by feeding during these recesses, indicating that metabolic costs and local foraging conditions drove incubation behavior. ?? 2010 US Government.

Self-referenced axial chromatic dispersion measurement in multiphoton microscopy through 2-color THG imaging.

PubMed

Du, Yu; Zhuang, Ziwei; He, Jiexing; Liu, Hongji; Qiu, Ping; Wang, Ke

2018-05-16

With tunable excitation light, multiphoton microscopy (MPM) is widely used for imaging biological structures at subcellular resolution. Axial chromatic dispersion, present in virtually every transmissive optical system including the multiphoton microscope, leads to focal (and the resultant image) plane separation. Here we demonstrate experimentally a technique to measure the axial chromatic dispersion in a multiphoton microscope, using simultaneous 2-color third-harmonic generation (THG) imaging excited by a 2-color soliton source with tunable wavelength separation. Our technique is self-referenced, eliminating potential measurement error when 1-color tunable excitation light is used which necessitates reciprocating motion of the mechanical translation stage. Using this technique, we demonstrate measured axial chromatic dispersion with 2 different objective lenses in a multiphoton microscope. Further measurement in a biological sample also indicates that this axial chromatic dispersion, in combination with 2-color imaging, may open up opportunity for simultaneous imaging of two different axial planes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

BRDF invariant stereo using light transport constancy.

PubMed

Wang, Liang; Yang, Ruigang; Davis, James E

2007-09-01

Nearly all existing methods for stereo reconstruction assume that scene reflectance is Lambertian and make use of brightness constancy as a matching invariant. We introduce a new invariant for stereo reconstruction called light transport constancy (LTC), which allows completely arbitrary scene reflectance (bidirectional reflectance distribution functions (BRDFs)). This invariant can be used to formulate a rank constraint on multiview stereo matching when the scene is observed by several lighting configurations in which only the lighting intensity varies. In addition, we show that this multiview constraint can be used with as few as two cameras and two lighting configurations. Unlike previous methods for BRDF invariant stereo, LTC does not require precisely configured or calibrated light sources or calibration objects in the scene. Importantly, the new constraint can be used to provide BRDF invariance to any existing stereo method whenever appropriate lighting variation is available.

Constance mirror program: Progress and plans

NASA Technical Reports Server (NTRS)

Klinkowstein, R. E.; Mauel, M. E.; Irby, J. H.; Smullin, L. D.; Voldman, S. H.

1981-01-01

The current state of the mechanics of the Constance II experiment, the physics results gathered, the motivation background, and future plans for the Constance II experiment are reviewed. Several improvements have been made and several experimental investigations have been completed. These include the construction/installation/testing of: (1) liquid-nitrogen cooled, Ioffe bars installed, (2) a diverter coil (3) the 100 kW ICRF generator, (4) the data acquisition system, and (5) the optimum hot-iron operation of the machine with Titanium and pulsed-gas plasma guns. Measurements were made of the density, temperature, and radius of the plasma. Ion-cyclotron fluctuations were observed, their bandwidth measured, and data collected demonstrating resonance heating. New X-ray diagnostics were designed and purchased, and progress on the Thomson scattering was made. Finally, a new hot cathode gun was designed and constructed.

Simultaneous hand-held contact color fundus and SD-OCT imaging for pediatric retinal diseases (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ruggeri, Marco; Hernandez, Victor; De Freitas, Carolina; Relhan, Nidhi; Silgado, Juan; Manns, Fabrice; Parel, Jean-Marie

2016-03-01

Hand-held wide-field contact color fundus photography is currently the standard method to acquire diagnostic images of children during examination under anesthesia and in the neonatal intensive care unit. The recent development of portable non-contact hand-held OCT retinal imaging systems has proved that OCT is of tremendous help to complement fundus photography in the management of pediatric patients. Currently, there is no commercial or research system that combines color wide-field digital fundus and OCT imaging in a contact-fashion. The contact of the probe with the cornea has the advantages of reducing motion experienced by the photographer during the imaging and providing fundus and OCT images with wider field of view that includes the periphery of the retina. In this study we produce proof of concept for a contact-type hand-held unit for simultaneous color fundus and OCT live view of the retina of pediatric patients. The front piece of the hand-held unit consists of a contact ophthalmoscopy lens integrating a circular light guide that was recovered from a digital fundus camera for pediatric imaging. The custom-made rear piece consists of the optics to: 1) fold the visible aerial image of the fundus generated by the ophthalmoscopy lens on a miniaturized level board digital color camera; 2) conjugate the eye pupil to the galvanometric scanning mirrors of an OCT delivery system. Wide-field color fundus and OCT images were simultaneously obtained in an eye model and sequentially obtained on the eye of a conscious 25 year-old human subject with healthy retina.

Requirements for the Military Message System (MMS) Family: Data Types and User Commands.

DTIC Science & Technology

1986-04-11

AD-A167 126 REQUIREMENTS FOR THE MILITARY MESSASE SYSTEM (NHS) i FRILY: DATA TYPES AND USER CONNNDS(U) NAVAL RESEARCH LAB WASHINGTON DC C L HEITHEVER... System (MMS) Family: Data Types and User Commands CONSTANCE L. HEITMEYER Computer Science and Systems Branch I Information Technology Division April 11...Security Classification) Requirements for the Military Message System (MMS) Family: Data Types and User Commands 12. PERSONAL AUTHOR(S) Heitmeer, Constance

Effects of constant immigration on the dynamics and persistence of stable and unstable Drosophila populations

PubMed Central

Dey, Snigdhadip; Joshi, Amitabh

2013-01-01

Constant immigration can stabilize population size fluctuations but its effects on extinction remain unexplored. We show that constant immigration significantly reduced extinction in fruitfly populations with relatively stable or unstable dynamics. In unstable populations with oscillations of amplitude around 1.5 times the mean population size, persistence and constancy were unrelated. Low immigration enhanced persistence without affecting constancy whereas high immigration increased constancy without enhancing persistence. In relatively stable populations with erratic fluctuations of amplitude close to the mean population size, both low and high immigration enhanced persistence. In these populations, the amplitude of fluctuations relative to mean population size went down due to immigration, and their dynamics were altered to low-period cycles. The effects of immigration on the population size distribution and intrinsic dynamics of stable versus unstable populations differed considerably, suggesting that the mechanisms by which immigration reduced extinction risk depended on underlying dynamics in complex ways. PMID:23470546

Pseudo color ghost coding imaging with pseudo thermal light

NASA Astrophysics Data System (ADS)

Duan, De-yang; Xia, Yun-jie

2018-04-01

We present a new pseudo color imaging scheme named pseudo color ghost coding imaging based on ghost imaging but with multiwavelength source modulated by a spatial light modulator. Compared with conventional pseudo color imaging where there is no nondegenerate wavelength spatial correlations resulting in extra monochromatic images, the degenerate wavelength and nondegenerate wavelength spatial correlations between the idle beam and signal beam can be obtained simultaneously. This scheme can obtain more colorful image with higher quality than that in conventional pseudo color coding techniques. More importantly, a significant advantage of the scheme compared to the conventional pseudo color coding imaging techniques is the image with different colors can be obtained without changing the light source and spatial filter.

Optimization of Ocean Color Algorithms: Application to Satellite Data Merging

NASA Technical Reports Server (NTRS)

Ritorena, Stephane; Siegel, David A.; Morel, Andre

2004-01-01

The objective of the program is to develop and validate a procedure for ocean color data merging, which is one of the major goals of the SIMBIOS project. As part of the SIMBIOS Program, we have developed a merging method for ocean color data. Conversely to other methods our approach does not combine end-products like the subsurface chlorophyll concentration (chl) from different sensors to generate a unified product. Instead, our procedure uses the normalized water-leaving radiances L((sub wN)(lambda)) from single or multiple sensors and uses them in the inversion of a semi-analytical ocean color model that allows the retrieval of several ocean color variables simultaneously. Beside ensuring simultaneity and consistency of the retrievals (all products are derived from a single algorithm), this model-based approach has various benefits over techniques that blend end-products (e.g. chlorophyll): 1) It works with single or multiple data sources regardless of their specific bands; 2) It exploits band redundancies and band differences; 3) It accounts for uncertainties in the L((sub wN)(lambda)) data; 4) It provides uncertainty estimates for the retrieved variables.

A simple method for electron energy constancy measurement

PubMed Central

King, R. Paul; Anderson, R. Scott

2001-01-01

A device is described for use in confirming the energy constancy of clinical electron beams. A wedge shaped absorber is placed over an ionization chamber leading to an energy dependent response. A measurement under the energy filter is divided by a measurement in air to correct for the inherent energy dependence of the chamber. A nearly linear response is demonstrated. PACS number(s): 87.52.–g, 87.53.–j, 87.66.–a PMID:11674838

Vertical Mixing In Western Lake Constance Due To Long Internal Waves

NASA Astrophysics Data System (ADS)

Boehrer, B.

Current profiles in the pelagic waters of western Lake Constance have been broken up into modes of the internal wave equation [1,2]. All current profiles can be well represented by a combination of the first and second mode wave. The temporal vari- ation of the modal composition with the interaction of the first and second mode im- plies current shear at varying depths. From current and density profiles, the gradient Richardson number can be evaluated in its spatial and temporal pattern with occa- tional occurence of supercritical values at all depths, also in the deep hypolimnion. An empiric connection between gradient Richardson number and diapycnical mixing [3] is applied to yield a profile of vertical transport coefficients, which can be com- pared with transport coefficients from gradient flux calculations of temperature and electrical conductivity profiles [4]. [1] B. Boehrer, J. Ilmberger and K.O. Münnich (2000): Vertical Structure of Current in Western Lake Constance, JGR-Oceans, 105 (12), 28823-28835 [2] B. Boehrer (2000): Modal Response of a Deep Stratified Lake: Western Lake Con- stance, JGR-Oceans, 105 (12), 28837-28845 [3] H. Peeters, M.C. Gregg and J.M. Toole (1988): On the parameterization of equa- torial turbulence, JGR, 93, 1199-1218 [4] G. Heinz, J. Ilmberger and M. Schimmele (1990): Vertical Mixing in Überlinger See, western part of Lake Constance, Aquat. Sci., 52(3), 256-268

Incubation behaviour of Greater Scaup Aythya marila on the Yukon-Kuskokwim Delta, Alaska

USGS Publications Warehouse

Flint, Paul L.

2003-01-01

This study examined the incubation behaviour of Greater Scaup Aythya marila on the Yukon-Kuskokwim Delta, Alaska. The goals of the study were to describe the incubation behaviour of Greater Scaup in terms of incubation constancy, recess frequency and recess length. The use of endogenous reserves by Greater Scaup was examined by determining weight loss over the incubation period. Further, intraspecific variation in incubation constancy was considered in terms of hypotheses regarding timing of reproduction. Constancy (% time on nest) averaged 59% during egg laying and increased to 83% during incubation. Patterns of daily incubation constancy varied among females, with no overall trend. Females took an average of 4.3 recesses per day, with an average length of 57 minutes. Body mass declined by 6.4 g day-1 and females initiating nests later tended to be lighter. These data suggest that while Greater Scaup utilise some stored reserves during incubation, they probably meet most of their energetic demands by foraging during incubation recesses. These data are not consistent with the hypothesis that females are initiating nests before adequate forage is available in the spring to meet the demands of egg production and maintenance. Thus, the observed delay in the onset of nesting by Greater Scaup, relative to other sympatric nesting species, does not appear to be related to inadequate forage to meet nutritional requirements.

Kirschmann's Fourth Law.

PubMed

Bosten, J M; Mollon, J D

2012-01-15

Kirschmann's Fourth Law states that the magnitude of simultaneous color contrast increases with the saturation of the inducing surround, but that the rate of increase reduces as saturation increases. Others since Kirschmann have agreed and disagreed. Here we show that the form of the relationship between simultaneous color contrast and inducer saturation depends on the method of measurement. Functions were measured by four methods: (i) asymmetric matching with a black surround, (ii) asymmetric matching with a surround metameric to equal energy white, (iii) dichoptic matching, and (iv) nulling an induced sinusoidal modulation. Results from the asymmetric matching conditions agreed with Kirschmann, whereas results from nulling and from dichoptic matching showed a more linear increase in simultaneous contrast with the saturation of the inducer. We conclude that the method certainly affects the conclusions reached, and that there may not be any "fair" way of measuring simultaneous contrast. Copyright © 2011 Elsevier Ltd. All rights reserved.

Subset selective search on the basis of color and preview.

PubMed

Donk, Mieke

2017-01-01

In the preview paradigm observers are presented with one set of elements (the irrelevant set) followed by the addition of a second set among which the target is presented (the relevant set). Search efficiency in such a preview condition has been demonstrated to be higher than that in a full-baseline condition in which both sets are simultaneously presented, suggesting that a preview of the irrelevant set reduces its influence on the search process. However, numbers of irrelevant and relevant elements are typically not independently manipulated. Moreover, subset selective search also occurs when both sets are presented simultaneously but differ in color. The aim of the present study was to investigate how numbers of irrelevant and relevant elements contribute to preview search in the absence and presence of a color difference between subsets. In two experiments it was demonstrated that a preview reduced the influence of the number of irrelevant elements in the absence but not in the presence of a color difference between subsets. In the presence of a color difference, a preview lowered the effect of the number of relevant elements but only when the target was defined by a unique feature within the relevant set (Experiment 1); when the target was defined by a conjunction of features (Experiment 2), search efficiency as a function of the number of relevant elements was not modulated by a preview. Together the results are in line with the idea that subset selective search is based on different simultaneously operating mechanisms.

Multi-dimensional effects of color on the world wide web

NASA Astrophysics Data System (ADS)

Morton, Jill

2002-06-01

Color is the most powerful building material of visual imagery on the World Wide Web. It must function successfully as it has done historically in traditional two-dimensional media, as well as address new challenges presented by this electronic medium. The psychological, physiological, technical and aesthetic effects of color have been redefined by the unique requirements of the electronic transmission of text and images on the Web. Color simultaneously addresses each of these dimensions in this electronic medium.

Spatio-temporal niche partitioning of closely related picocyanobacteria clades and phycocyanin pigment types in Lake Constance (Germany).

PubMed

Becker, Sven; Sánchez-Baracaldo, Patricia; Singh, Arvind K; Hayes, Paul K

2012-05-01

We found that the clade-specific abundance dynamics of Synechococcus type picocyanobacteria in the pelagic and littoral zone macro-habitats of Lake Constance (Germany) challenge the hypothesis of a regular annual succession of picocyanobacteria genotypes in temperate zone lakes. Methods used in this study were quantitative Taq nuclease assays (TNA), denaturing gradient gel electrophoresis (DGGE), a 19-month time series analysis (with two isothermal and two stratified periods) and genotyping of a new littoral phycocyanin (PC)-rich Synechococcus strain collection. The recorded differences between the two macro-habitats and between seasons or years, and the observed effect of water column mixis in winter on the inversion of clade-specific dominance ratios in Lake Constance might explain the known inter-annual differences in abundance and dynamics of the autotrophic picoplankton (APP) in lakes. The APP in Lake Constance shows a high genetic diversity with a low overall abundance, similar to the APP in the Baltic Sea, but different from Lake Biwa in Japan or lakes in the UK. Our results indicate that APP bloom events in both macro-habitats of Lake Constance are driven by phycoerythrin-rich Synechococcus genotypes of the Subalpine Cluster I. DGGE revealed the presence of a diverse periphyton (biofilm) community of the PC-rich Synechococcus pigment type in the littoral zone in early spring, when no such community was detectable in the pelagic habitat. A more sensitive and quantitative approach with TNA, however, revealed an intermittent presence of one PC-rich genotype in the plankton. We discuss the seasonal development of the pelagic and littoral PC-rich community, and while we cannot rule out a strain isolation bias, we found that isolated PC-rich strains from the pelagic habitat have different genotypes when compared to new littoral strains. We also observed littoral substrates colonized by specific PC-rich Synechococcus genotypes. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

SU-E-T-257: Output Constancy: Reducing Measurement Variations in a Large Practice Group

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hedrick, K; Fitzgerald, T; Miller, R

2014-06-01

Purpose: To standardize output constancy check procedures in a large medical physics practice group covering multiple sites, in order to identify and reduce small systematic errors caused by differences in equipment and the procedures of multiple physicists. Methods: A standardized machine output constancy check for both photons and electrons was instituted within the practice group in 2010. After conducting annual TG-51 measurements in water and adjusting the linac to deliver 1.00 cGy/MU at Dmax, an acrylic phantom (comparable at all sites) and PTW farmer ion chamber are used to obtain monthly output constancy reference readings. From the collected charge reading,more » measurements of air pressure and temperature, and chamber Ndw and Pelec, a value we call the Kacrylic factor is determined, relating the chamber reading in acrylic to the dose in water with standard set-up conditions. This procedure easily allows for multiple equipment combinations to be used at any site. The Kacrylic factors and output results from all sites and machines are logged monthly in a central database and used to monitor trends in calibration and output. Results: The practice group consists of 19 sites, currently with 34 Varian and 8 Elekta linacs (24 Varian and 5 Elekta linacs in 2010). Over the past three years, the standard deviation of Kacrylic factors measured on all machines decreased by 20% for photons and high energy electrons as systematic errors were found and reduced. Low energy electrons showed very little change in the distribution of Kacrylic values. Small errors in linac beam data were found by investigating outlier Kacrylic values. Conclusion: While the use of acrylic phantoms introduces an additional source of error through small differences in depth and effective depth, the new standardized procedure eliminates potential sources of error from using many different phantoms and results in more consistent output constancy measurements.« less

MO-FG-202-04: Gantry-Resolved Linac QA for VMAT: A Comprehensive and Efficient System Using An Electronic Portal Imaging Device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zwan, B J; University of Newcastle, Newcastle, NSW; Barnes, M

2016-06-15

Purpose: To automate gantry-resolved linear accelerator (linac) quality assurance (QA) for volumetric modulated arc therapy (VMAT) using an electronic portal imaging device (EPID). Methods: A QA system for VMAT was developed that uses an EPID, frame-grabber assembly and in-house developed image processing software. The system relies solely on the analysis of EPID image frames acquired without the presence of a phantom. Images were acquired at 8.41 frames per second using a frame grabber and ancillary acquisition computer. Each image frame was tagged with a gantry angle from the linac’s on-board gantry angle encoder. Arc-dynamic QA plans were designed to assessmore » the performance of each individual linac component during VMAT. By analysing each image frame acquired during the QA deliveries the following eight machine performance characteristics were measured as a function of gantry angle: MLC positional accuracy, MLC speed constancy, MLC acceleration constancy, MLC-gantry synchronisation, beam profile constancy, dose rate constancy, gantry speed constancy, dose-gantry angle synchronisation and mechanical sag. All tests were performed on a Varian iX linear accelerator equipped with a 120 leaf Millennium MLC and an aS1000 EPID (Varian Medical Systems, Palo Alto, CA, USA). Results: Machine performance parameters were measured as a function of gantry angle using EPID imaging and compared to machine log files and the treatment plan. Data acquisition is currently underway at 3 centres, incorporating 7 treatment units, at 2 weekly measurement intervals. Conclusion: The proposed system can be applied for streamlined linac QA and commissioning for VMAT. The set of test plans developed can be used to assess the performance of each individual components of the treatment machine during VMAT deliveries as a function of gantry angle. The methodology does not require the setup of any additional phantom or measurement equipment and the analysis is fully automated to allow for regular routine testing.« less

Simultaneous enhancement of photo- and electroluminescence in white organic light-emitting devices by localized surface plasmons of silver nanoclusters

NASA Astrophysics Data System (ADS)

Yu, Jingting; Zhu, Wenqing; Shi, Guanjie; Zhai, Guangsheng; Qian, Bingjie; Li, Jun

2017-02-01

White organic light-emitting devices (WOLEDs) with enhanced current efficiency and negligible color shifting equipped with an internal color conversion layer (CCL) were fabricated. They were attained by embedding a single layer of silver nanoclusters (SNCs) between the CCL and light-emitting layer (EML). The simultaneous enhancement of the photoluminescence (PL) of the CCL and electroluminescence (EL) of the EML were realized by controlling the thickness and size of the SNCs to match the localized surface plasmon resonance spectrum with the PL spectrum of the CCL and the EL spectrum of the EML. The WOLED with optimal SNCs demonstrated a 25.81% enhancement in current efficiency at 60 mA cm-2 and good color stability over the entire range of current density.

Near-simultaneous ultraviolet and optical spectrophotometry of T Tauri stars

NASA Technical Reports Server (NTRS)

Goodrich, Robert W.; Herbig, G. H.

1986-01-01

A set of near-simultaneous ultraviolet and optical spectra and UBVR(J)I(J) photometry of five T Tauri stars has been analyzed for the shape of the energy distribution shortward of 3000 A. The far-ultraviolet continua of these stars are very much stronger than the level of light scattered from longer wavelengths in the IUE spectrograph. The results, expressed as two-color plots, show that the UV colors of T Tauri stars differ significantly from those expected from their optical spectral types. Although these particular K-type T Tauri stars are not extreme members of the class, they have the UV colors of A stars. The spectral shape of this UV excess is approximately that expected from published chromospheric models of T Tauri stars.

Factors influencing hand/eye synchronicity in the computer age.

PubMed

Grant, A H

1992-09-01

In using a computer, the relation of vision to hand/finger actuated keyboard usage in performing fine motor-coordinated functions is influenced by the physical location, size, and collective placement of the keys. Traditional nonprehensile flat/rectangular keyboard applications usually require a high and nearly constant level of visual attention. Biometrically shaped keyboards would allow for prehensile hand-posturing, thus affording better tactile familiarity with the keys, requiring less intense and less constant level of visual attention to the task, and providing a greater measure of freedom from having to visualize the key(s). Workpace and related physiological changes, aging, onset of monocularization (intermittent lapsing of binocularity for near vision) that accompanies presbyopia, tool colors, and background contrast are factors affecting constancy of visual attention to task performance. Capitas extension, excessive excyclotorsion, and repetitive strain injuries (such as carpal tunnel syndrome) are common and debilitating concomitants to computer usage. These problems can be remedied by improved keyboard design. The salutary role of mnemonics in minimizing visual dependency is discussed.

Expedition 52 Crew Patch-042517

NASA Image and Video Library

2016-11-17

ISS052-s-001 (01/27/2016) --- Orbiting the Earth continuously since 1998, the International Space Station (ISS) is one of our greatest engineering achievements. It is depicted in gold, symbolic of constancy and excellence. Flying directly toward a sunrise represents the ISS’s contributions to a bright future. That sunrise and the Earth beneath ituses blue, white, red, and green, the combined national colors of Italy, Russia, and the United States, symbolizing the crew’s cohesiveness. Crewmember names are in blue symbolizing devotion and loyalty. The white border represents sunlight unscattered by the Earth’s atmosphere. Symbolic of new Russian and U.S. spacecraft that will further human exploration, the patch is shaped as a capsule. The number 52 is drawn as a path eventually leading to Mars. Finally, the stars symbolize the values of leadership, trust, teamwork, and excellence lived by mission control teams throughout the history of human space programs, as well as their global vigilance in operating the ISS.

Coherence of particulate beam attenuation and backscattering coefficients in diverse open ocean environments.

PubMed

Westberry, Toby K; Dall'Olmo, Giorgio; Boss, Emmanuel; Behrenfeld, Michael J; Moutin, Thierry

2010-07-19

We present an extensive data set of particle attenuation (c(p)), backscattering (b(bp)), and chlorophyll concentration (Chl) from a diverse set of open ocean environments. A consistent observation in the data set is the strong coherence between c(p) and b(bp) and the resulting constancy of the backscattering ratio (0.010 +/- 0.002). The strong covariability between c(p) and b(bp) must be rooted in one or both of two explanations, 1) the size distribution of particles in the ocean is remarkably conserved and particle types responsible for c(p) and b(bp) covary, 2) the same particle types exert influence on both quantities. Therefore, existing relationships between c(p) or Chl:c(p) and phytoplankton biomass and physiological indices can be conceptually extended to the use of b(bp). This finding lends support to use of satellite-derived Chl and b(bp) for investigation of phytoplankton biomass and physiology and broadens the applications of existing ocean color retrievals.

Information Sharing within the COEA Process

DTIC Science & Technology

1993-12-01

Foster. Cost Accounting . EnO Cliffs NJ: Prentice Hall, 1991. Irwin, F.C. An Expert System For Measuring. Inting. and Managing System Performance Factors...AD-A273 906 /El~lhll~lR~IUiM "AFIT/GIR/LAR/93D-9 DTIC ELECTE DEC2 11993 INFORMATION SHARING WITHIN THE COEA PROCESS THESIS Constance S . Maginnis, GS...the Requirements for the Degree of Master of Science in Information Resource Management Constance S . Maginnis, B.S. Michael J. Monroe, M.A. GS-13, USAF

Age, class and race discrimination: their interactions and associations with mental health among Brazilian university students.

PubMed

Bastos, João Luiz; Barros, Aluisio J D; Celeste, Roger Keller; Paradies, Yin; Faerstein, Eduardo

2014-01-01

Although research on discrimination and health has progressed significantly, it has tended to focus on racial discrimination and US populations. This study explored different types of discrimination, their interactions and associations with common mental disorders among Brazilian university students, in Rio de Janeiro in 2010. Associations between discrimination and common mental disorders were examined using multiple logistic regression models, adjusted for confounders. Interactions between discrimination and socio-demographics were tested. Discrimination attributed to age, class and skin color/race were the most frequently reported. In a fully adjusted model, discrimination attributed to skin color/race and class were both independently associated with increased odds of common mental disorders. The simultaneous reporting of skin color/race, class and age discrimination was associated with the highest odds ratio. No significant interactions were found. Skin color/race and class discrimination were important, but their simultaneous reporting, in conjunction with age discrimination, were associated with the highest occurrence of common mental disorders.

Synaesthesia and colour constancy.

PubMed

Erskine, Holly; Mattingley, Jason B; Arnold, Derek H

2013-04-01

Grapheme-colour synaesthesia is an atypical condition characterized by the perception of colours when reading achromatic text. We investigated the level of colour processing responsible for these experiences. To do so, we tapped a central characteristic of colour perception. In different lighting conditions the same wavelength of light can prompt the perception of different colours. This helps humans recognize distinctive coloured objects despite changes in illumination. We wanted to see if synaesthetic colours were generated at a neural locus that was susceptible to colour constancy analyses. We used colour matching and naming tasks to examine interactions between simulated coloured illuminants and synaesthetic colours. Neither synaesthetic colour matching or naming was impacted. This contrasted with non-synaesthetic control participants, who performed the colour-matching task with graphemes physically coloured to mimic synaesthesia. Our data suggest that synaesthetic colour signals are not generated at lower-levels of colour processing, but are introduced at higher levels of analysis and are therefore not impacted by the processes responsible for perceptual constancy. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Simultaneous Red - Blue Lidar and Airborne Impactor Measurements

NASA Technical Reports Server (NTRS)

McCormick, M. P.; Blifford, I. H.; Fuller, W. H.; Grams, G. W.

1973-01-01

Simultaneous two-color (0.6943 micrometers and 0.3472 micrometers) LIDAR measurements were made in the troposphere and lower stratosphere over Boulder, Colorado during March 1973. In addition, on the evening of March 26, airborne single-stage impactor measurements were made at four altitudes-- 10,500, 25,000, 33,000 and 43,000 feet MSL. These data were integrated at constant altitude for 15,45, 45, and 60 minutes respectively. The LIDAR data were taken with Langley's 48" LIDAR using a dichroic beamsplitter to separate the return at 0.6943 micrometers and 0.3472 micrometers. The analog waveforms for both colors were digitized simultaneously; one on an NCAR data acquisition system and the other on the 48" Langley data acquisition system. A discussion of the preliminary results from these measurements will be presented.

Mechanical properties of elytra from Tribolium castaneum wild-type and body color mutant strains

USDA-ARS?s Scientific Manuscript database

Cuticle tanning in insects involves simultaneous cuticular hardening and pigmentation. The dynamic mechanical properties of the highly modified and cuticle-rich forewings (elytra) from Tribolium castaneum (red flour beetle) body color mutant strains were investigated to determine the relationship b...

Robust colour constancy in red-green dichromats

PubMed Central

Linhares, João M. M.; Moreira, Humberto; Lillo, Julio; Nascimento, Sérgio M. C.

2017-01-01

Colour discrimination has been widely studied in red-green (R-G) dichromats but the extent to which their colour constancy is affected remains unclear. This work estimated the extent of colour constancy for four normal trichromatic observers and seven R-G dichromats when viewing natural scenes under simulated daylight illuminants. Hyperspectral imaging data from natural scenes were used to generate the stimuli on a calibrated CRT display. In experiment 1, observers viewed a reference scene illuminated by daylight with a correlated colour temperature (CCT) of 6700K; observers then viewed sequentially two versions of the same scene, one illuminated by either a higher or lower CCT (condition 1, pure CCT change with constant luminance) or a higher or lower average luminance (condition 2, pure luminance change with a constant CCT). The observers’ task was to identify the version of the scene that looked different from the reference scene. Thresholds for detecting a pure CCT change or a pure luminance change were estimated, and it was found that those for R-G dichromats were marginally higher than for normal trichromats regarding CCT. In experiment 2, observers viewed sequentially a reference scene and a comparison scene with a CCT change or a luminance change above threshold for each observer. The observers’ task was to identify whether or not the change was an intensity change. No significant differences were found between the responses of normal trichromats and dichromats. These data suggest robust colour constancy mechanisms along daylight locus in R-G dichromacy. PMID:28662218

Robust colour constancy in red-green dichromats.

PubMed

Álvaro, Leticia; Linhares, João M M; Moreira, Humberto; Lillo, Julio; Nascimento, Sérgio M C

2017-01-01

Colour discrimination has been widely studied in red-green (R-G) dichromats but the extent to which their colour constancy is affected remains unclear. This work estimated the extent of colour constancy for four normal trichromatic observers and seven R-G dichromats when viewing natural scenes under simulated daylight illuminants. Hyperspectral imaging data from natural scenes were used to generate the stimuli on a calibrated CRT display. In experiment 1, observers viewed a reference scene illuminated by daylight with a correlated colour temperature (CCT) of 6700K; observers then viewed sequentially two versions of the same scene, one illuminated by either a higher or lower CCT (condition 1, pure CCT change with constant luminance) or a higher or lower average luminance (condition 2, pure luminance change with a constant CCT). The observers' task was to identify the version of the scene that looked different from the reference scene. Thresholds for detecting a pure CCT change or a pure luminance change were estimated, and it was found that those for R-G dichromats were marginally higher than for normal trichromats regarding CCT. In experiment 2, observers viewed sequentially a reference scene and a comparison scene with a CCT change or a luminance change above threshold for each observer. The observers' task was to identify whether or not the change was an intensity change. No significant differences were found between the responses of normal trichromats and dichromats. These data suggest robust colour constancy mechanisms along daylight locus in R-G dichromacy.

MoniQA: a general approach to monitor quality assurance

NASA Astrophysics Data System (ADS)

Jacobs, J.; Deprez, T.; Marchal, G.; Bosmans, H.

2006-03-01

MoniQA ("Monitor Quality Assurance") is a new, non-commercial, independent quality assurance software application developed in our medical physics team. It is a complete Java TM - based modular environment for the evaluation of radiological viewing devices and it thus fits in the global quality assurance network of our (film less) radiology department. The purpose of the software tool is to guide the medical physicist through an acceptance protocol and the radiologist through a constancy check protocol by presentation of the necessary test patterns and by automated data collection. Data are then sent to a central management system for further analysis. At the moment more than 55 patterns have been implemented, which can be grouped in schemes to implement protocols (i.e. AAPMtg18, DIN and EUREF). Some test patterns are dynamically created and 'drawn' on the viewing device with random parameters as is the case in a recently proposed new pattern for constancy testing. The software is installed on 35 diagnostic stations (70 monitors) in a film less radiology department. Learning time was very limited. A constancy check -with the new pattern that assesses luminance decrease, resolution problems and geometric distortion- takes only 2 minutes and 28 seconds per monitor. The modular approach of the software allows the evaluation of new or emerging test patterns. We will report on the software and its usability: practicality of the constancy check tests in our hospital and on the results from acceptance tests of viewing stations for digital mammography.

Multicolor Super-Resolution Fluorescence Imaging via Multi-Parameter Fluorophore Detection

PubMed Central

Bates, Mark; Dempsey, Graham T; Chen, Kok Hao; Zhuang, Xiaowei

2012-01-01

Understanding the complexity of the cellular environment will benefit from the ability to unambiguously resolve multiple cellular components, simultaneously and with nanometer-scale spatial resolution. Multicolor super-resolution fluorescence microscopy techniques have been developed to achieve this goal, yet challenges remain in terms of the number of targets that can be simultaneously imaged and the crosstalk between color channels. Herein, we demonstrate multicolor stochastic optical reconstruction microscopy (STORM) based on a multi-parameter detection strategy, which uses both the fluorescence activation wavelength and the emission color to discriminate between photo-activatable fluorescent probes. First, we obtained two-color super-resolution images using the near-infrared cyanine dye Alexa 750 in conjunction with a red cyanine dye Alexa 647, and quantified color crosstalk levels and image registration accuracy. Combinatorial pairing of these two switchable dyes with fluorophores which enhance photo-activation enabled multi-parameter detection of six different probes. Using this approach, we obtained six-color super-resolution fluorescence images of a model sample. The combination of multiple fluorescence detection parameters for improved fluorophore discrimination promises to substantially enhance our ability to visualize multiple cellular targets with sub-diffraction-limit resolution. PMID:22213647

Bias Selective Operation of Sb-Based Two-Color Photodetectors

NASA Technical Reports Server (NTRS)

Abedin, M. N.; Refaat, Tamer F.; Bhat, Ishwara B.; Xiao, Yegao; Johnson, David G.

2006-01-01

Multicolor detectors have a strong potential to replace conventional single-color detectors in application dealing with the simultaneous detection of more than one wavelength. This will lead to the reduction of heavy and complex optical components now required for spectral discrimination for multi-wavelengths applications. This multicolor technology is simpler, lighter, compact and cheaper with respect to the single-color ones. In this paper, Sb-based two-color detectors fabrication and characterization are presented. The color separation is achieved by fabricating dual band pn junction on a GaSb substrate. The first band consists of an InGaAsSb pn junction for long wavelength detection, while the second band consists of a GaSb pn junction for shorter wavelength detection. Three metal contacts were deposited to access the individual junctions. Surface morphology of multi-layer thin films and also device characteristics of quasi-dual band photodetector were characterized using standard optical microscope and electro-optic techniques respectively. Dark current measurements illustrated the diode behavior of both lattice-matched detector bands. Spectral response measurements indicated either independent operation of both detectors simultaneously, or selective operation of one detector, by the polarity of the bias voltage, while serially accessing both devices.

Dual-colored graphene quantum dots-labeled nanoprobes/graphene oxide: functional carbon materials for respective and simultaneous detection of DNA and thrombin

NASA Astrophysics Data System (ADS)

Qian, Zhao Sheng; Shan, Xiao Yue; Chai, Lu Jing; Chen, Jian Rong; Feng, Hui

2014-10-01

Convenient and simultaneous detection of multiple biomarkers such as DNA and proteins with biocompatible materials and good analytical performance still remains a challenge. Herein, we report the respective and simultaneous detection of DNA and bovine α-thrombin (thrombin) entirely based on biocompatible carbon materials through a specially designed fluorescence on-off-on process. Colorful fluorescence, high emission efficiency, good photostability and excellent compatibility enables graphene quantum dots (GQDs) as the best choice for fluorophores in bioprobes, and thus two-colored GQDs as labeling fluorophores were chemically bonded with specific oligonucleotide sequence and aptamer to prepare two probes targeting the DNA and thrombin, respectively. Each probe can be assembled on the graphene oxide (GO) platform spontaneously by π-π stacking and electrostatic attraction; as a result, fast electron transfer in the assembly efficiently quenches the fluorescence of probe. The presence of DNA or thrombin can trigger the self-recognition between capturing a nucleotide sequence and its target DNA or between thrombin and its aptamer due to their specific hybridization and duplex DNA structures or the formation of apatamer-substrate complex, which is taken advantage of in order to achieve a separate quantitative analysis of DNA and thrombin. A dual-functional biosensor for simultaneous detection of DNA and thrombin was also constructed by self-assembly of two probes with distinct colors and GO platform, and was further evaluated with the presence of various concentrations of DNA and thrombin. Both biosensors serving as a general detection model for multiple species exhibit outstanding analytical performance, and are expected to be applied in vivo because of the excellent biocompatibility of their used materials.

The fabrication of a multi-spectral lens array and its application in assisting color blindness

NASA Astrophysics Data System (ADS)

Di, Si; Jin, Jian; Tang, Guanrong; Chen, Xianshuai; Du, Ruxu

2016-01-01

This article presents a compact multi-spectral lens array and describes its application in assisting color-blindness. The lens array consists of 9 microlens, and each microlens is coated with a different color filter. Thus, it can capture different light bands, including red, orange, yellow, green, cyan, blue, violet, near-infrared, and the entire visible band. First, the fabrication process is described in detail. Second, an imaging system is setup and a color blindness testing card is selected as the sample. By the system, the vision results of normal people and color blindness can be captured simultaneously. Based on the imaging results, it is possible to be used for helping color-blindness to recover normal vision.

Effects of display characteristics and individual differences on preferences of VDT icon design.

PubMed

Shieh, Kong-King; Ko, Ya-Hsien

2005-04-01

This study explored the effects of display characteristics such as target/background color combination, single/simultaneous presentation, and individual differences by sex, and design specialty on preferences of VDT icon design. The results indicated black targets (black-on-white, black-on-yellow) and black backgrounds (red-on-black, yellow-on-black) were the most popular and white targets (white-on-red, white-on-black) and white backgrounds (blue-on-white, red-on-white) were the second most popular. As for the chromatic color combinations, yellow-on-blue was the most favored. Subjects rated color combinations under single presentation higher than those under simultaneous presentation. Women rated purplish targets and rated purplish and blue backgrounds higher than men. Subjects with design background favored black more either as a target or background, but they favored turquoise less than those without design background.

Spatial carrier color digital speckle pattern interferometry for absolute three-dimensional deformation measurement

NASA Astrophysics Data System (ADS)

Gao, Xinya; Wang, Yonghong; Li, Junrui; Dan, Xizuo; Wu, Sijin; Yang, Lianxiang

2017-06-01

It is difficult to measure absolute three-dimensional deformation using traditional digital speckle pattern interferometry (DSPI) when the boundary condition of an object being tested is not exactly given. In practical applications, the boundary condition cannot always be specifically provided, limiting the use of DSPI in real-world applications. To tackle this problem, a DSPI system that is integrated by the spatial carrier method and a color camera has been established. Four phase maps are obtained simultaneously by spatial carrier color-digital speckle pattern interferometry using four speckle interferometers with different illumination directions. One out-of-plane and two in-plane absolute deformations can be acquired simultaneously without knowing the boundary conditions using the absolute deformation extraction algorithm based on four phase maps. Finally, the system is proved by experimental results through measurement of the deformation of a flat aluminum plate with a groove.

Dual-Tasking Alleviated Sleep Deprivation Disruption in Visuomotor Tracking: An fMRI Study

ERIC Educational Resources Information Center

Gazes, Yunglin; Rakitin, Brian C.; Steffener, Jason; Habeck, Christian; Butterfield, Brady; Basner, Robert C.; Ghez, Claude; Stern, Yaakov

2012-01-01

Effects of dual-responding on tracking performance after 49-h of sleep deprivation (SD) were evaluated behaviorally and with functional magnetic resonance imaging (fMRI). Continuous visuomotor tracking was performed simultaneously with an intermittent color-matching visual detection task in which a pair of color-matched stimuli constituted a…

Color and alcohol removal for the simultaneous detection of amino acids and sugars in wine by two-dimensional ion chromatography.

PubMed

Fa, Yun; Liu, Yinghui; Xu, Aihua; Yu, Yuexue; Li, Fangfang; Liu, Huizhou

2017-09-15

An effective pretreatment method for wine color removal by a PS-DVB SPE cartridge and online alcohol elimination by valve switching was presented. The optimum parameters for color removal were investigated: 40-μm and 100Å poly (styrene)-divinylbenzene (PS-DVB) (0.4g) was selected as the color removal material and 5mL of ethanol (10%) as the elution solvent for sample pretreatment under given condition. Moreover, an accurate and automated two-dimensional ion chromatography method for the simultaneous detection of amino acids and sugars was achieved with two valves after injection without alcohol interference. The method had a mean correlation coefficient of >0.99 and a repeatability of 0.92%-4.30% for eight replicates. The mean recovery of six red wine samples were 97.6%, 96.6%, 96.1%, 95.9%, 97.3% and 96.4% respectively. And this method successfully analyzed the amino acid and sugar contents of six wine samples of different origins. Copyright © 2017. Published by Elsevier B.V.

A Dual-Modality System for Both Multi-Color Ultrasound-Switchable Fluorescence and Ultrasound Imaging

PubMed Central

Kandukuri, Jayanth; Yu, Shuai; Cheng, Bingbing; Bandi, Venugopal; D’Souza, Francis; Nguyen, Kytai T.; Hong, Yi; Yuan, Baohong

2017-01-01

Simultaneous imaging of multiple targets (SIMT) in opaque biological tissues is an important goal for molecular imaging in the future. Multi-color fluorescence imaging in deep tissues is a promising technology to reach this goal. In this work, we developed a dual-modality imaging system by combining our recently developed ultrasound-switchable fluorescence (USF) imaging technology with the conventional ultrasound (US) B-mode imaging. This dual-modality system can simultaneously image tissue acoustic structure information and multi-color fluorophores in centimeter-deep tissue with comparable spatial resolutions. To conduct USF imaging on the same plane (i.e., x-z plane) as US imaging, we adopted two 90°-crossed ultrasound transducers with an overlapped focal region, while the US transducer (the third one) was positioned at the center of these two USF transducers. Thus, the axial resolution of USF is close to the lateral resolution, which allows a point-by-point USF scanning on the same plane as the US imaging. Both multi-color USF and ultrasound imaging of a tissue phantom were demonstrated. PMID:28165390

Two-Photon Probes for Lysosomes and Mitochondria: Simultaneous Detection of Lysosomes and Mitochondria in Live Tissues by Dual-Color Two-Photon Microscopy Imaging.

PubMed

Lim, Chang Su; Hong, Seung Taek; Ryu, Seong Shick; Kang, Dong Eun; Cho, Bong Rae

2015-10-01

Novel two-photon (TP) probes were developed for lysosomes (PLT-yellow) and mitochondria (BMT-blue and PMT-yellow). These probes emitted strong TP-excited fluorescence in cells at widely separated wavelength regions and displayed high organelle selectivity, good cell permeability, low cytotoxicity, and pH insensitivity. The BMT-blue and PLT-yellow probes could be utilized to detect lysosomes and mitochondria simultaneously in live tissues by using dual-color two-photon microscopy, with minimum interference from each other. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Medical diagnosis system and method with multispectral imaging. [depth of burns and optical density of the skin

NASA Technical Reports Server (NTRS)

Anselmo, V. J.; Reilly, T. H. (Inventor)

1979-01-01

A skin diagnosis system includes a scanning and optical arrangement whereby light reflected from each incremental area (pixel) of the skin is directed simultaneously to three separate light filters, e.g., IR, red, and green. As a result, the three devices simultaneously produce three signals which are directly related to the reflectance of light of different wavelengths from the corresponding pixel. These three signals for each pixel after processing are used as inputs to one or more output devices to produce a visual color display and/or a hard copy color print, for one usable as a diagnostic aid by a physician.

Effects of environmental factors on incubation patterns of Greater Sage-Grouse

USGS Publications Warehouse

Coates, Peter S.; Delehanty, David J.

2008-01-01

Birds in which only one sex incubates the eggs are often faced with a direct conflict between foraging to meet metabolic needs and incubation. Knowledge of environmental and ecological factors that shape life-history strategies of incubation is limited. We used continuous videography to make precise measurements of female Greater Sage-Grouse (Centrocercus urophasianus) incubation constancy (percentage of time spent at the nest in a 24-hour period) and recess duration. We used an information-theoretic approach to evaluate incubation patterns in relation to grouse age, timing of incubation, raven abundance, microhabitat, weather, and food availability. Overall, sage-grouse females showed an incubation constancy of 96% and a distinctive bimodal distribution of brief incubation recesses that peaked at sunset and 30 min prior to sunrise. Grouse typically returned to their nests during low light conditions. Incubation constancy of yearlings was lower than that of adults, particularly in the later stages of incubation. Yearlings spent more time away from nests later in the morning and earlier in the evening compared to adults. Video images revealed that nearly all predation events by Common Ravens (Corvus corax), the most frequently recorded predator at sage-grouse nests, took place during mornings and evenings after sunrise and before sunset, respectively. These were the times of the day when sage-grouse typically returned from incubation recesses. Recess duration was negatively related to raven abundance. We found evidence that incubation constancy increased with greater visual obstruction, usually from vegetation, of nests. An understanding of how incubation patterns relate to environmental factors will help managers make decisions aimed at increasing productivity through successful incubation.

Small or far away? Size and distance perception in the praying mantis

PubMed Central

Bissianna, Geoffrey

2016-01-01

Stereo or ‘3D’ vision is an important but costly process seen in several evolutionarily distinct lineages including primates, birds and insects. Many selective advantages could have led to the evolution of stereo vision, including range finding, camouflage breaking and estimation of object size. In this paper, we investigate the possibility that stereo vision enables praying mantises to estimate the size of prey by using a combination of disparity cues and angular size cues. We used a recently developed insect 3D cinema paradigm to present mantises with virtual prey having differing disparity and angular size cues. We predicted that if they were able to use these cues to gauge the absolute size of objects, we should see evidence for size constancy where they would strike preferentially at prey of a particular physical size, across a range of simulated distances. We found that mantises struck most often when disparity cues implied a prey distance of 2.5 cm; increasing the implied distance caused a significant reduction in the number of strikes. We, however, found no evidence for size constancy. There was a significant interaction effect of the simulated distance and angular size on the number of strikes made by the mantis but this was not in the direction predicted by size constancy. This indicates that mantises do not use their stereo vision to estimate object size. We conclude that other selective advantages, not size constancy, have driven the evolution of stereo vision in the praying mantis. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269605

Cues to viewing distance for stereoscopic depth constancy.

PubMed

Glennerster, A; Rogers, B J; Bradshaw, M F

1998-01-01

A veridical estimate of viewing distance is required in order to determine the metric structure of objects from binocular stereopsis. One example of a judgment of metric structure, which we used in our experiment, is the apparently circular cylinder task (E B Johnston, 1991 Vision Research 31 1351-1360). Most studies report underconstancy in this task when the stimulus is defined purely by binocular disparities. We examined the effect of two factors on performance: (i) the richness of the cues to viewing distance (using either a naturalistic setting with many cues to viewing distance or a condition in which the room and the monitors were obscured from view), and (ii) the range of stimulus disparities (cylinder depths) presented during an experimental run. We tested both experienced subjects (who had performed the task many times before under full-cue conditions) and naïve subjects. Depth constancy was reduced for the naïve subjects (from 62% to 46%) when the position of the monitors was obscured. Under similar conditions, the experienced subjects showed no reduction in constancy. In a second experiment, using a forced-choice method of constant stimuli, we found that depth constancy was reduced from 64% to 23% in naïve subjects and from 77% to 55% in experienced subjects when the same set of images was presented at all viewing distances rather than using a set of stimulus disparities proportional to the correct setting. One possible explanation of these results is that, under reduced-cue conditions, the range of disparities presented is used by the visual system as a cue to viewing distance.

Development of two color laser diagnostics for the ITER poloidal polarimeter.

PubMed

Kawahata, K; Akiyama, T; Tanaka, K; Nakayama, K; Okajima, S

2010-10-01

Two color laser diagnostics using terahertz laser sources are under development for a high performance operation of the Large Helical Device and for future fusion devices such as ITER. So far, we have achieved high power laser oscillation lines simultaneously oscillating at 57.2 and 47.7 μm by using a twin optically pumped CH(3)OD laser, and confirmed the original function, compensation of mechanical vibration, of the two color laser interferometer. In this article, application of the two color laser diagnostics to the ITER poloidal polarimeter and recent hardware developments will be described.

Pseudo-color coding method for high-dynamic single-polarization SAR images

NASA Astrophysics Data System (ADS)

Feng, Zicheng; Liu, Xiaolin; Pei, Bingzhi

2018-04-01

A raw synthetic aperture radar (SAR) image usually has a 16-bit or higher bit depth, which cannot be directly visualized on 8-bit displays. In this study, we propose a pseudo-color coding method for high-dynamic singlepolarization SAR images. The method considers the characteristics of both SAR images and human perception. In HSI (hue, saturation and intensity) color space, the method carries out high-dynamic range tone mapping and pseudo-color processing simultaneously in order to avoid loss of details and to improve object identifiability. It is a highly efficient global algorithm.

Dodging the cosmic curvature to probe the constancy of the speed of light

NASA Astrophysics Data System (ADS)

Cai, Rong-Gen; Guo, Zong-Kuan; Yang, Tao

2016-08-01

We develop a new model-independent method to probe the constancy of the speed of light c. In our method, the degeneracy between the cosmic curvature and the speed of light can be eliminated, which makes the test more natural and general. Combining the independent observations of Hubble parameter H(z) and luminosity distance dL(z), we use the model-independent smoothing technique, Gaussian processes, to reconstruct them and then detect variation of the speed of light. We find no signal of deviation from the present value of the speed of light c0. Moreover, to demonstrate the improvement in probing the constancy of the speed of light from future experiments, we produce a series of simulated data. The Dark Energy Survey will be able to detect Δc/c0 ~ 1% at ~ 1.5σ confidence level and Δc/c0 ~ 2% at ~ 3σ confidence level. If the errors are reduced to one-tenth of the expected DES ones, it can detect a Δc/c0 ~ 0.1% variation at ~ 2σ confidence level.

Perception of Upright: Multisensory Convergence and the Role of Temporo-Parietal Cortex

PubMed Central

Kheradmand, Amir; Winnick, Ariel

2017-01-01

We inherently maintain a stable perception of the world despite frequent changes in the head, eye, and body positions. Such “orientation constancy” is a prerequisite for coherent spatial perception and sensorimotor planning. As a multimodal sensory reference, perception of upright represents neural processes that subserve orientation constancy through integration of sensory information encoding the eye, head, and body positions. Although perception of upright is distinct from perception of body orientation, they share similar neural substrates within the cerebral cortical networks involved in perception of spatial orientation. These cortical networks, mainly within the temporo-parietal junction, are crucial for multisensory processing and integration that generate sensory reference frames for coherent perception of self-position and extrapersonal space transformations. In this review, we focus on these neural mechanisms and discuss (i) neurobehavioral aspects of orientation constancy, (ii) sensory models that address the neurophysiology underlying perception of upright, and (iii) the current evidence for the role of cerebral cortex in perception of upright and orientation constancy, including findings from the neurological disorders that affect cortical function. PMID:29118736

Effect of perceptual load on conceptual processing: an extension of Vermeulen's theory.

PubMed

Xie, Jiushu; Wang, Ruiming; Sun, Xun; Chang, Song

2013-10-01

The effect of color and shape load on conceptual processing was studied. Perceptual load effects have been found in visual and auditory conceptual processing, supporting the theory of embodied cognition. However, whether different types of visual concepts, such as color and shape, share the same perceptual load effects is unknown. In the current experiment, 32 participants were administered simultaneous perceptual and conceptual tasks to assess the relation between perceptual load and conceptual processing. Keeping color load in mind obstructed color conceptual processing. Hence, perceptual processing and conceptual load shared the same resources, suggesting embodied cognition. Color conceptual processing was not affected by shape pictures, indicating that different types of properties within vision were separate.

Color-binding errors during rivalrous suppression of form.

PubMed

Hong, Sang Wook; Shevell, Steven K

2009-09-01

How does a physical stimulus determine a conscious percept? Binocular rivalry provides useful insights into this question because constant physical stimulation during rivalry causes different visual experiences. For example, presentation of vertical stripes to one eye and horizontal stripes to the other eye results in a percept that alternates between horizontal and vertical stripes. Presentation of a different color to each eye (color rivalry) produces alternating percepts of the two colors or, in some cases, a color mixture. The experiments reported here reveal a novel and instructive resolution of rivalry for stimuli that differ in both form and color: perceptual alternation between the rivalrous forms (e.g., horizontal or vertical stripes), with both eyes' colors seen simultaneously in separate parts of the currently perceived form. Thus, the colors presented to the two eyes (a) maintain their distinct neural representations despite resolution of form rivalry and (b) can bind separately to distinct parts of the perceived form.

True color scanning laser ophthalmoscopy and optical coherence tomography handheld probe

PubMed Central

LaRocca, Francesco; Nankivil, Derek; Farsiu, Sina; Izatt, Joseph A.

2014-01-01

Scanning laser ophthalmoscopes (SLOs) are able to achieve superior contrast and axial sectioning capability compared to fundus photography. However, SLOs typically use monochromatic illumination and are thus unable to extract color information of the retina. Previous color SLO imaging techniques utilized multiple lasers or narrow band sources for illumination, which allowed for multiple color but not “true color” imaging as done in fundus photography. We describe the first “true color” SLO, handheld color SLO, and combined color SLO integrated with a spectral domain optical coherence tomography (OCT) system. To achieve accurate color imaging, the SLO was calibrated with a color test target and utilized an achromatizing lens when imaging the retina to correct for the eye’s longitudinal chromatic aberration. Color SLO and OCT images from volunteers were then acquired simultaneously with a combined power under the ANSI limit. Images from this system were then compared with those from commercially available SLOs featuring multiple narrow-band color imaging. PMID:25401032

One-step simultaneous differential scanning calorimetry-FTIR microspectroscopy to quickly detect continuous pathways in the solid-state glucose/asparagine Maillard reaction.

PubMed

Hwang, Deng-Fwu; Hsieh, Tzu-Feng; Lin, Shan-Yang

2013-01-01

The stepwise reaction pathway of the solid-state Maillard reaction between glucose (Glc) and asparagine (Asn) was investigated using simultaneous differential scanning calorimetry (DSC)-FTIR microspectroscopy. The color change and FTIR spectra of Glc-Asn physical mixtures (molar ratio = 1:1) preheated to different temperatures followed by cooling were also examined. The successive reaction products such as Schiff base intermediate, Amadori product, and decarboxylated Amadori product in the solid-state Glc-Asn Maillard reaction were first simultaneously evidenced by this unique DSC-FTIR microspectroscopy. The color changed from white to yellow-brown to dark brown, and appearance of new IR peaks confirmed the formation of Maillard reaction products. The present study clearly indicates that this unique DSC-FTIR technique not only accelerates but also detects precursors and products of the Maillard reaction in real time.

Iterative color-multiplexed, electro-optical processor.

PubMed

Psaltis, D; Casasent, D; Carlotto, M

1979-11-01

A noncoherent optical vector-matrix multiplier using a linear LED source array and a linear P-I-N photodiode detector array has been combined with a 1-D adder in a feedback loop. The resultant iterative optical processor and its use in solving simultaneous linear equations are described. Operation on complex data is provided by a novel color-multiplexing system.

All set! Evidence of simultaneous attentional control settings for multiple target colors.

PubMed

Irons, Jessica L; Folk, Charles L; Remington, Roger W

2012-06-01

Although models of visual search have often assumed that attention can only be set for a single feature or property at a time, recent studies have suggested that it may be possible to maintain more than one attentional control setting. The aim of the present study was to investigate whether spatial attention could be guided by multiple attentional control settings for color. In a standard spatial cueing task, participants searched for either of two colored targets accompanied by an irrelevantly colored distractor. Across five experiments, results consistently showed that nonpredictive cues matching either target color produced a significant spatial cueing effect, while irrelevantly colored cues did not. This was the case even when the target colors could not be linearly separated from irrelevantly cue colors in color space, suggesting that participants were not simply adopting one general color set that included both target colors. The results could not be explained by intertrial priming by previous targets, nor could they be explained by a single inhibitory set for the distractor color. Overall, the results are most consistent with the maintenance of multiple attentional control settings.

Role of Gestalt grouping in selective attention: evidence from the Stroop task.

PubMed

Lamers, Martijn J M; Roelofs, Ardi

2007-11-01

Selective attention has been intensively studied using the Stroop task. Evidence suggests that Stroop interference in a color-naming task arises partly because of visual attention sharing between color and word: Removing the target color after 150 msec reduces interference (Neumann, 1986). Moreover, removing both the color and the word simultaneously reduces interference less than does removing the color only (La Heij, van der Heijden, & Plooij, 2001). These findings could also be attributed to Gestalt grouping principles, such as common fate. We report three experiments in which the role of Gestalt grouping was further investigated. Experiment I replicated the reduced interference, using words and color patches. In Experiment 2, the color patch was not removed but only repositioned (<2 degrees) after 100 msec, which also reduced interference. In Experiment 3, the distractor was repositioned while the target remained stationary, again reducing interference. These results indicate a role for Gestalt grouping in selective attention.

Colorful displays signal male quality in a tropical anole lizard

NASA Astrophysics Data System (ADS)

Cook, Ellee G.; Murphy, Troy G.; Johnson, Michele A.

2013-10-01

Parasites influence colorful ornaments and their behavioral display in many animal hosts. Because coloration and display behavior are often critical components of communication, variation in these traits may have important implications for individual fitness, yet it remains unclear whether such traits are signals of quality in many taxa. We investigated the association between ectoparasitic mite load and the color and behavioral use of the throat fan (dewlap) by male Anolis brevirostris lizards. We found that heavily parasitized lizards exhibited lower body condition, duller dewlaps, and less frequent dewlap displays than less parasitized individuals. Our results thus suggest that highly parasitized individuals invest less in both ornamental color and behavioral display of that color. Because the two components of the signal simultaneously provide information on male quality, this study provides novel support for the long-standing hypothesis that colorful traits may function as social or sexual signals in reptiles.

The Development and Validation of the Algebra Curriculum Based Measure: A Measure of Preschool Children's Sorting and Classifying Skills

ERIC Educational Resources Information Center

Maherally, Mohammad Iqbal

2014-01-01

The purpose of this study was to develop and validate an assessment tool entitled the Algebra Curriculum Based Measure (ACBM) with the intent of measuring preschool children's sorting and classifying skills based on one attribute (color, shape, and size) and two attributes (color and shape) simultaneously; and their ability to explain their…

Simultaneous dual-color fluorescence microscope: a characterization study.

PubMed

Li, Zheng; Chen, Xiaodong; Ren, Liqiang; Song, Jie; Li, Yuhua; Zheng, Bin; Liu, Hong

2013-01-01

High spatial resolution and geometric accuracy is crucial for chromosomal analysis of clinical cytogenetic applications. High resolution and rapid simultaneous acquisition of multiple fluorescent wavelengths can be achieved by utilizing concurrent imaging with multiple detectors. However, such class of microscopic systems functions differently from traditional fluorescence microscopes. To develop a practical characterization framework to assess and optimize the performance of a high resolution and dual-color fluorescence microscope designed for clinical chromosomal analysis. A dual-band microscopic imaging system utilizes a dichroic mirror, two sets of specially selected optical filters, and two detectors to simultaneously acquire two fluorescent wavelengths. The system's geometric distortion, linearity, the modulation transfer function, and the dual detectors' alignment were characterized. Experiment results show that the geometric distortion at lens periphery is less than 1%. Both fluorescent channels show linear signal responses, but there exists discrepancy between the two due to the detectors' non-uniform response ratio to different wavelengths. In terms of the spatial resolution, the two contrast transfer function curves trend agreeably with the spatial frequency. The alignment measurement allows quantitatively assessing the cameras' alignment. A result image of adjusted alignment is demonstrated to show the reduced discrepancy by using the alignment measurement method. In this paper, we present a system characterization study and its methods for a specially designed imaging system for clinical cytogenetic applications. The presented characterization methods are not only unique to this dual-color imaging system but also applicable to evaluation and optimization of other similar multi-color microscopic image systems for improving their clinical utilities for future cytogenetic applications.

Constance Pascal's Chagrins d'amour et psychoses (1935): a French psychiatrist's views on psychoanalysis.

PubMed

Gordon, Felicia

2015-03-01

In 1935 Constance Pascal (1877-1937), France's first woman psychiatrist, published Chagrins d'amour et psychoses (The Sorrows of Love and Psychosis). My analysis of her monograph will consider: her major article leading up to Chagrins; Pascal's debts to her predecessors, particularly Morel and Kretschmer; her relationship to the French psychoanalytic movement; her co-option of psychoanalysis as a tool in her own therapeutic work with patients in the state psychiatric system; and her social/cultural interpretations of her woman patients. The literary and philosophic aspects of her work are emphasized as well as her contribution to French psychiatry. © The Author(s) 2014.

Viewing distance matter to perceived intensity of facial expressions

PubMed Central

Gerhardsson, Andreas; Högman, Lennart; Fischer, Håkan

2015-01-01

In our daily perception of facial expressions, we depend on an ability to generalize across the varied distances at which they may appear. This is important to how we interpret the quality and the intensity of the expression. Previous research has not investigated whether this so called perceptual constancy also applies to the experienced intensity of facial expressions. Using a psychophysical measure (Borg CR100 scale) the present study aimed to further investigate perceptual constancy of happy and angry facial expressions at varied sizes, which is a proxy for varying viewing distances. Seventy-one (42 females) participants rated the intensity and valence of facial expressions varying in distance and intensity. The results demonstrated that the perceived intensity (PI) of the emotional facial expression was dependent on the distance of the face and the person perceiving it. An interaction effect was noted, indicating that close-up faces are perceived as more intense than faces at a distance and that this effect is stronger the more intense the facial expression truly is. The present study raises considerations regarding constancy of the PI of happy and angry facial expressions at varied distances. PMID:26191035

Articulation effects in lightness: historical background and theoretical implications.

PubMed

Gilchrist, Alan L; Annan, Vidal

2002-01-01

The concept of articulation was first introduced by Katz [1935 The World of Colour (London: Kegan Paul, Trench, Trubner & Co)] to refer to the degree of complexity within a field. Katz, who created the basic research methods for studying lightness constancy, found that the greater the degree of articulation within a field of illumination, the greater the degree of constancy. Even though this concept has been largely forgotten, there is much empirical evidence for Katz's principle, and the effects on lightness are very strong. However, when articulation is increased within a framework that does not coincide with a region of illumination, constancy is weakened. Kardos (1934 Zeitschrift für Psychologie Ergänzungband 23) advanced the concept of co-determination, according to which the lightness of a surface is determined relative to more than one field of illumination. Gilchrist et al (1999 Psychological Review 106 795-834) argue that the fields concept should be replaced by the more operational frameworks concept and that a wide variety of lightness errors can be explained by a modification of the Katz principle: the greater the articulation within a perceptual framework, the stronger the anchoring of lightness values within that framework.

Dodging the cosmic curvature to probe the constancy of the speed of light

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, Rong-Gen; Guo, Zong-Kuan; Yang, Tao, E-mail: cairg@itp.ac.cn, E-mail: guozk@itp.ac.cn, E-mail: yangtao@itp.ac.cn

We develop a new model-independent method to probe the constancy of the speed of light c . In our method, the degeneracy between the cosmic curvature and the speed of light can be eliminated, which makes the test more natural and general. Combining the independent observations of Hubble parameter H ( z ) and luminosity distance d {sub L} ( z ), we use the model-independent smoothing technique, Gaussian processes, to reconstruct them and then detect variation of the speed of light. We find no signal of deviation from the present value of the speed of light c {sub 0}.more » Moreover, to demonstrate the improvement in probing the constancy of the speed of light from future experiments, we produce a series of simulated data. The Dark Energy Survey will be able to detect Δ c / c {sub 0} ∼ 1% at ∼ 1.5σ confidence level and Δ c / c {sub 0} ∼ 2% at ∼ 3σ confidence level. If the errors are reduced to one-tenth of the expected DES ones, it can detect a Δ c / c {sub 0} ∼ 0.1% variation at ∼ 2σ confidence level.« less

Color temperature measurement in laser-driven shock waves

NASA Astrophysics Data System (ADS)

Hall, T. A.; Benuzzi, A.; Batani, D.; Beretta, D.; Bossi, S.; Faral, B.; Koenig, M.; Krishnan, J.; Löautwer, Th.; Mahdieh, M.

1997-06-01

A simultaneous measurement of color temperature and shock velocity in laser-driven shocks is presented. The color temperature was measured from the target rear side emissivity, and the shock velocity by using stepped targets. A very good planarity of the shock was ensured by the phase zone plate smoothing technique. A simple model of the shock luminosity has been developed in order to estimate the shock temperature from the experimental rear side emissivity. Results have been compared to temperatures obtained from the shock velocity for a material of a known equation of state.

Use of Multiangle Satellite Observations to Retrieve Aerosol Properties and Ocean Color

NASA Technical Reports Server (NTRS)

Martonchik, John V.; Diner, David; Khan, Ralph

2005-01-01

A new technique is described for retrieving aerosol over ocean water and the associated ocean color using multiangle satellite observations. Unlike current satellite aerosol retrieval algorithms which only utilize observations at red wavelengths and longer, with the assumption that these wavelengths have a negligible ocean (water-leaving radiance), this new algorithm uses all available spectral bands and simultaneously retrieves both aerosol properties and the spectral ocean color. We show some results of case studies using MISR data, performed over different water conditions (coastal water, blooms, and open water).

In vivo tooth-color measurement with a new 3D intraoral scanning system in comparison to conventional digital and visual color determination methods.

PubMed

Mehl, Albert; Bosch, Gabriel; Fischer, Carolin; Ender, Andreas

Three-dimensional (3D) intraoral scanning systems allow for the simultaneous acquisition of 3D information about tooth surfaces and a photorealistic view of the patient's tooth colors. The goal of this study was the in vivo comparison of a new 3D scanner with a color acquisition mode and conventional visual and digital color measurements. The colors of 40 teeth of 20 patients were evaluated in seven ways: 1) By dentists using the Vita 3D-Master; 2) By dental technicians using the Vita 3D-Master; 3) With the 3Shape Trios device; 4) With the Vita Easyshade device; 5) With the Vita Easyshade Advance device; 6) With the SpectroShade device; and 7) With the SpectroShade Micro device. Digital measurements of Groups 3 to 7 were repeated three times for each tooth. For all groups, both the CIE Lab values and the Vita 3D-Master values were recorded. The repeatability and relative accuracy of the Vita 3D-Master values were analyzed statistically using Pearson's chi-squared test (α < 0.05). ΔE values were calculated from the CIE Lab values, which served as a basis for performing multidimensional scaling (MDS) and evaluating differences between the groups using the one-way ANOVA with post hoc Tamhane's test (α < 0.05). The results of the ΔE values showed that clinically relevant differences between the evaluation by dentists, dental technicians, and the intraoral scanning device (3Shape) are negligible. The intraoral 3D scanning device (Group 3) and the digital systems (Groups 4 to 7) did not differ significantly in the repeatability of color shade management. The SpectroShade Micro (Group 7) had significantly better relative accuracy than the other devices. The results demonstrate that intraoral scanning systems can be used to measure both tooth color and tooth surface in 3D. Intraoral optical scanning devices allow for the acquisition of accurate 3D surface data. Tooth color can be evaluated simultaneously and can be used to determine the color of restorations without requiring additional conventional color-measurement methods.

The principle of relativity and the indeterminacy of special relativity

NASA Astrophysics Data System (ADS)

de Abreu, Rodrigo; Guerra, Vasco

2008-01-01

This work ends a trilogy devoted to a journey into the foundations of special relativity. The first paper debated the meaning of the constancy of the two-way speed of light and its close relation to the conceptualization of time. The second one addressed the question of the possible constancy of the one-way speed of light and the trivial—but, unfortunately, even now somewhat controversial—question of the compatibility between the assumption of a special system of reference and Einstein's special relativity. The present study deals with the principle of relativity. Its historical evolution is reviewed and a 'weak' formulation is defended. It is emphasized that many assertions usually associated with special relativity, such as the 'relativity of time dilation' and 'relativity of space contraction' are indeed philosophical statements, as it has been established already by several authors in the past. Nonetheless, most teachers and scientists still believe nowadays they are implied by the theory and by the group property of the Lorentz transformation. This is by no means so, as it is reviewed and elucidated with the simple example on space contraction. It is argued that the lack of knowledge of the true value of the one-way speed of light in empty space leaves the theory undetermined. Einstein's special relativity corresponds to a simple and very elegant solution to this problem, allowing the study of relative motion without any concern with the study of absolute motion, which is considered to be superfluous. However, its standard interpretation is minimalist and even misleading. A large number of researchers have discussed this question, mostly within the conventionality of simultaneity thesis. The typical formulation of this thesis provides some new physical insight and points out the problem, but does not solve it. In contrast, it often leads to a labyrinth of difficult language which is herein clarified.

Global color and albedo variations on Io

USGS Publications Warehouse

McEwen, A.S.

1988-01-01

Three multispectral mosaics of Io have been produced from Voyager imaging data: a global mosaic from each of the Voyager 1 and Voyager 2 data sets and a high-resolution mosaic of the region surrounding the volcano Ra Patera. The mosaics are maps of normal albedo and color in accurate geometric map formats. Io's photometric behavior, mapped with a two-image technique, is spatially variable, especially in the bright white areas. The disk-integrated color and albedo of the satellite have been remarkably constant over recent decades, despite the volcanic activity and the many differences between Voyager 1 and 2 images (acquired just 4 months apart). This constancy is most likely due to the consistent occurrence of large Pele-type plumes with relatively dark, red deposits in the region from long 240 to 360??. A transient brightening southeast of Pele during the Voyager 1 encounter was probably due to real changes in surface and/or atmospheric materials, rather than to photometric behavior. The intrinsic spectral variability of Io, as seen in a series of two-dimensional histograms of the multispectral mosaics, consists of continuous variation among three major spectral end members. The data were mapped into five spectral units to compare them with laboratory measurements of candidate surface materials and to show the planimetric distributions. Unit 1 is best fit by the spectral reflectance of ordinary elemental sulfur, and it is closely associated with the Peletype plume deposits. Unit 2 is strongly confined to the polar caps above about latitude ??50??, but its composition is unknown. Unit 5 is probably SO2 with relatively minor contamination; it is concentrated in the equatorial region and near the long-lived Prometheus-type plumes. Units 3 and 4 are gradational between units 1 and 5. In addition to SO2 and elemental sulfur, other plausible components of the surface are polysulfur oxides, FeCl2, Na2S, and NaHS. ?? 1988.

Simultaneous monitoring of independent gene expression patterns in two types of cocultured fibroblasts with different color-emitting luciferases

PubMed Central

Noguchi, Takako; Ikeda, Masaaki; Ohmiya, Yoshihiro; Nakajima, Yoshihiro

2008-01-01

Background Luciferase assay systems enable the real-time monitoring of gene expression in living cells. We have developed a dual-color luciferase assay system in which the expression of multiple genes can be tracked simultaneously using green- and red-emitting beetle luciferases. We have applied the system to monitoring independent gene expressions in two types of cocultured fibroblasts in real time. Results Two Rat-1 cell lines were established that stably express either green- or red-emitting luciferases under the control of the mBmal1 promoter, a canonical clock gene. We cocultured these cell lines, and gene expression profiles in both were monitored simultaneously. The circadian rhythms of these cell lines are independent, oscillating following their intrinsic circadian phases, even when cocultured. Furthermore, the independent rhythms were synchronized by medium change as an external stimulus. Conclusion Using this system, we successfully monitored independent gene expression patterns in two lines of cocultured fibroblasts. PMID:18416852

Feature-binding errors after eye movements and shifts of attention.

PubMed

Golomb, Julie D; L'heureux, Zara E; Kanwisher, Nancy

2014-05-01

When people move their eyes, the eye-centered (retinotopic) locations of objects must be updated to maintain world-centered (spatiotopic) stability. Here, we demonstrated that the attentional-updating process temporarily distorts the fundamental ability to bind object locations with their features. Subjects were simultaneously presented with four colors after a saccade-one in a precued spatiotopic target location-and were instructed to report the target's color using a color wheel. Subjects' reports were systematically shifted in color space toward the color of the distractor in the retinotopic location of the cue. Probabilistic modeling exposed both crude swapping errors and subtler feature mixing (as if the retinotopic color had blended into the spatiotopic percept). Additional experiments conducted without saccades revealed that the two types of errors stemmed from different attentional mechanisms (attention shifting vs. splitting). Feature mixing not only reflects a new perceptual phenomenon, but also provides novel insight into how attention is remapped across saccades.

[Use of computer technologies for studying the morphological characteristics of the iris color in anthropology].

PubMed

Dorofeeva, A A; Khrustalev, A V; Krylov, Iu V; Bocharov, D A; Negasheva, M A

2010-01-01

Digital images of the iris were received for study peculiarities of the iris color during the anthropological examination of 578 students aged 16-24 years. Simultaneously with the registration of the digital images, the visual assessment of the eye color was carried out using the traditional scale of Bunak, based on 12 ocular prostheses. Original software for automatic determination of the iris color based on 12 classes scale of Bunak was designed, and computer version of that scale was developed. The software proposed allows to conduct the determination of the iris color with high validity based on numerical evaluation; its application may reduce the bias due to subjective assessment and methodological divergences of the different researchers. The software designed for automatic determination of the iris color may help develop both theoretical and applied anthropology, it may be used in forensic and emergency medicine, sports medicine, medico-genetic counseling and professional selection.

Color Change for Thermoregulation versus Camouflage in Free-Ranging Lizards.

PubMed

Smith, Kathleen R; Cadena, Viviana; Endler, John A; Kearney, Michael R; Porter, Warren P; Stuart-Fox, Devi

2016-12-01

Animal coloration has multiple functions including thermoregulation, camouflage, and social signaling, and the requirements of each function may sometimes conflict. Many terrestrial ectotherms accommodate the multiple functions of color through color change. However, the relative importance of these functions and how color-changing species accommodate them when they do conflict are poorly understood because we lack data on color change in the wild. Here, we show that the color of individual radio-tracked bearded dragon lizards, Pogona vitticeps, correlates strongly with background color and less strongly, but significantly, with temperature. We found no evidence that individuals simultaneously optimize camouflage and thermoregulation by choosing light backgrounds when hot or dark backgrounds when cold. In laboratory experiments, lizards showed both UV-visible (300-700 nm) and near-infrared (700-2,100 nm) reflectance changes in response to different background and temperature treatments, consistent with camouflage and thermoregulatory functions, respectively, but with no interaction between the two. Overall, our results suggest that wild bearded dragons change color to improve both thermoregulation and camouflage but predominantly adjust for camouflage, suggesting that compromising camouflage may entail a greater potential immediate survival cost.

Multimodal digital color imaging system for facial skin lesion analysis

NASA Astrophysics Data System (ADS)

Bae, Youngwoo; Lee, Youn-Heum; Jung, Byungjo

2008-02-01

In dermatology, various digital imaging modalities have been used as an important tool to quantitatively evaluate the treatment effect of skin lesions. Cross-polarization color image was used to evaluate skin chromophores (melanin and hemoglobin) information and parallel-polarization image to evaluate skin texture information. In addition, UV-A induced fluorescent image has been widely used to evaluate various skin conditions such as sebum, keratosis, sun damages, and vitiligo. In order to maximize the evaluation efficacy of various skin lesions, it is necessary to integrate various imaging modalities into an imaging system. In this study, we propose a multimodal digital color imaging system, which provides four different digital color images of standard color image, parallel and cross-polarization color image, and UV-A induced fluorescent color image. Herein, we describe the imaging system and present the examples of image analysis. By analyzing the color information and morphological features of facial skin lesions, we are able to comparably and simultaneously evaluate various skin lesions. In conclusion, we are sure that the multimodal color imaging system can be utilized as an important assistant tool in dermatology.

Impacts of selected stimulation patterns on the perception threshold in electrocutaneous stimulation

PubMed Central

2011-01-01

Background Consistency is one of the most important concerns to convey stable artificially induced sensory feedback. However, the constancy of perceived sensations cannot be guaranteed, as the artificially evoked sensation is a function of the interaction of stimulation parameters. The hypothesis of this study is that the selected stimulation parameters in multi-electrode cutaneous stimulation have significant impacts on the perception threshold. Methods The investigated parameters included the stimulated location, the number of active electrodes, the number of pulses, and the interleaved time between a pair of electrodes. Biphasic, rectangular pulses were applied via five surface electrodes placed on the forearm of 12 healthy subjects. Results Our main findings were: 1) the perception thresholds at the five stimulated locations were significantly different (p < 0.0001), 2) dual-channel simultaneous stimulation lowered the perception thresholds and led to smaller variance in perception thresholds compared to single-channel stimulation, 3) the perception threshold was inversely related to the number of pulses, and 4) the perception threshold increased with increasing interleaved time when the interleaved time between two electrodes was below 500 μs. Conclusions To maintain a consistent perception threshold, our findings indicate that dual-channel simultaneous stimulation with at least five pulses should be used, and that the interleaved time between two electrodes should be longer than 500 μs. We believe that these findings have implications for design of reliable sensory feedback codes. PMID:21306616

Color Restoration of RGBN Multispectral Filter Array Sensor Images Based on Spectral Decomposition.

PubMed

Park, Chulhee; Kang, Moon Gi

2016-05-18

A multispectral filter array (MSFA) image sensor with red, green, blue and near-infrared (NIR) filters is useful for various imaging applications with the advantages that it obtains color information and NIR information simultaneously. Because the MSFA image sensor needs to acquire invisible band information, it is necessary to remove the IR cut-offfilter (IRCF). However, without the IRCF, the color of the image is desaturated by the interference of the additional NIR component of each RGB color channel. To overcome color degradation, a signal processing approach is required to restore natural color by removing the unwanted NIR contribution to the RGB color channels while the additional NIR information remains in the N channel. Thus, in this paper, we propose a color restoration method for an imaging system based on the MSFA image sensor with RGBN filters. To remove the unnecessary NIR component in each RGB color channel, spectral estimation and spectral decomposition are performed based on the spectral characteristics of the MSFA sensor. The proposed color restoration method estimates the spectral intensity in NIR band and recovers hue and color saturation by decomposing the visible band component and the NIR band component in each RGB color channel. The experimental results show that the proposed method effectively restores natural color and minimizes angular errors.

Evaluation of photo-mutagenicity and photo-cytotoxicity of food coloring agents.

PubMed

Arimoto-Kobayashi, Sakae; Machida, Masaki; Okamoto, Keinosuke; Yamaguchi, Akie

2005-05-01

Pigments extracted from natural products are widely used for food coloration in Japan. An investigation concerning the photo-mutagenicity and photo-carcinogenicity of frequently used colorants in Japan was performed. Colorants examined were from Laccifer lacca (lac-color), Coccus cacti (cochineal-color), Carthamus tinctorius (carthamus yellow), Gardenia augusta (gardenia yellow and gardenia blue), Monascus anka and Monascus purpureus (monascus red), the skin of Vitis vinifera and Vitis labrusca (grape-skin color), Tamarindus indica (tamarind brown) and Beta vulgaris (beet red). No significant increase in bacterial mutation was found when Salmonella typhimurium TA98, TA100 and TA102 were simultaneously treated with colorants and subjected to UVA irradiation for 30 min. When colorant solutions were subjected to UVA irradiation for 4 h, irradiated solutions containing lac-color became slightly mutagenic toward S.typhimurium TA98 without metabolic activation. A decrease in cell survival resulted when WTK-1 cells were subjected to UVA irradiation for 60 min in the presence of purpurin at 1 mg/ml. Delayed cytotoxicity was also observed following 24 h incubation in fresh medium of samples that were subjected to UVA irradiation for 60 min in the presence of colorant (carthamus yellow, grape-skin color, gardenia blue, cochineal-color, monascus red or purpurin).

Color Restoration of RGBN Multispectral Filter Array Sensor Images Based on Spectral Decomposition

PubMed Central

Park, Chulhee; Kang, Moon Gi

2016-01-01

A multispectral filter array (MSFA) image sensor with red, green, blue and near-infrared (NIR) filters is useful for various imaging applications with the advantages that it obtains color information and NIR information simultaneously. Because the MSFA image sensor needs to acquire invisible band information, it is necessary to remove the IR cut-offfilter (IRCF). However, without the IRCF, the color of the image is desaturated by the interference of the additional NIR component of each RGB color channel. To overcome color degradation, a signal processing approach is required to restore natural color by removing the unwanted NIR contribution to the RGB color channels while the additional NIR information remains in the N channel. Thus, in this paper, we propose a color restoration method for an imaging system based on the MSFA image sensor with RGBN filters. To remove the unnecessary NIR component in each RGB color channel, spectral estimation and spectral decomposition are performed based on the spectral characteristics of the MSFA sensor. The proposed color restoration method estimates the spectral intensity in NIR band and recovers hue and color saturation by decomposing the visible band component and the NIR band component in each RGB color channel. The experimental results show that the proposed method effectively restores natural color and minimizes angular errors. PMID:27213381

Progress in color reflection holography

NASA Astrophysics Data System (ADS)

Bjelkhagen, Hans I.; Huang, Qiang; Jeong, Tung H.

1998-02-01

The recording technique of Denisyuk color reflection holograms has been simplified by using `white' laser light. The Slavich red-green-blue (RGB) sensitized ultra-high resolution silver halide emulsion was used for the hologram recording. The employed laser wavelengths were 633 nm, 531 nm, and 476 nm, generated by a helium-neon, a mixed argon- krypton ion, and an argon ion laser, respectively. A beam combination mechanism with dichroic filters enabled a simultaneously RGB exposure, which made the color balance and overall exposure energy easy to control as well as simplifying the recording procedure. Various approaches have been investigated in generating color hologram which have sufficiently high diffraction efficiency combined with improved color saturation. A specially designed test object consisting of the 1931 CIE chromaticity diagram, a rainbow ribbon cable, pure yellow dots, and a cloisonne elephant was used for color recording experiments. In addition, the Macbeth Color Checker chart was used. Both colorimetric evaluation and scattering noise measurements were performed using the PR-650 Photo Research SpectraScan SpectraCalorimeter.

Color multiplexing method to capture front and side images with a capsule endoscope.

PubMed

Tseng, Yung-Chieh; Hsu, Hsun-Ching; Han, Pin; Tsai, Cheng-Mu

2015-10-01

This paper proposes a capsule endoscope (CE), based on color multiplexing, to simultaneously record front and side images. Only one lens associated with an X-cube prism is employed to catch the front and side view profiles in the CE. Three color filters and polarizers are placed on three sides of an X-cube prism. When objects locate at one of the X-cube's three sides, front and side view profiles of different colors will be caught through the proposed lens and recorded at the color image sensor. The proposed color multiplexing CE (CMCE) is designed with a field of view of up to 210 deg and a 180 lp/mm resolution under f-number 2.8 and overall length 13.323 mm. A ray-tracing simulation in the CMCE with the color multiplexing mechanism verifies that the CMCE not only records the front and side view profiles at the same time, but also has great image quality at a small size.

Apparent size contrasts of retinal images and size constancy as determinants of the moon illusion.

PubMed

Smith, O W; Smith, P C; Geist, C C; Zimmermann, R R

1978-06-01

Kaufman and Rock (1962) and Rock and Kaufman (1962) concluded that the moon illusion is a function of and attributable to apparent distance. They also reported a large framing effect as an exception. Analysis of the effect suggests two components which can account for the illusion independently of apparent distance. These are apparent size contrasts of visual images of discriminable features or objects of the earth with the moon's image and size constancy of the features or objects plus the interactions of the two. Apparent distances to horizons are always a consequence of the necessary conditions for the illusion. They are related to the illusion but are not a determinant of it.

Stokes image reconstruction for two-color microgrid polarization imaging systems.

PubMed

Lemaster, Daniel A

2011-07-18

The Air Force Research Laboratory has developed a new microgrid polarization imaging system capable of simultaneously reconstructing linear Stokes parameter images in two colors on a single focal plane array. In this paper, an effective method for extracting Stokes images is presented for this type of camera system. It is also shown that correlations between the color bands can be exploited to significantly increase overall spatial resolution. Test data is used to show the advantages of this approach over bilinear interpolation. The bounds (in terms of available reconstruction bandwidth) on image resolution are also provided.

Race, embodiment and later life: Re-animating aging bodies of color.

PubMed

Rajan-Rankin, Sweta

2018-06-01

This theoretical essay examines the intersections between race, ethnicity and old age from an inter-disciplinary lens. Drawing on cultural gerontology (especially embodied aging studies) and post-colonial perspectives on aging, it explores how an emphasis on the body and embodiment can serve as a conceptual lens for understanding racialized aging bodies. A tentative framework for analysis is proposed. The concept of exile explores how bodies of color and older bodies are denigrated through the hegemonic (white, youth-centered, masculinist) gaze. Re-animation can take place by transcending double-consciousness: 'seeing beyond' the dominant gaze. Othering and otherness are explored in relation to both raced and aging bodies. The limits of ethnic aging are scrutinized at an epistemic level, simultaneously informing, and obscuring the understanding of lived experiences of racialized ethnic minorities in old age. Visible and invisible difference provide a way of unpacking the simultaneous hypervisibility of older (female) bodies of color, and their invisibility in institutional and policy discourses. De-coloniality is considered, by exploring ways to resist hegemonic power through embodied ways of knowing. This article concludes by exploring how recent methodological innovations - especially the visual and sensory turn - can offer new ways of understanding the lived experiences of aging bodies of color. Copyright © 2018 The Author. Published by Elsevier Inc. All rights reserved.

A Study on Visibility Estimation of Web-Safe Colors using Paired Comparison and Discriminant Analysis

NASA Astrophysics Data System (ADS)

Saito, Daisuke; Saito, Keiichi; Notomi, Kazuhiro; Saito, Masao

This paper presents the visibility ordering of several web safe colors. The research of web page visibility is important because of the rapid dissemination of the World Wide Web. The combination of a foreground color and a background color is an important factor in providing sufficient visibility. Therefore, the rating of color combination visibility is necessary when developing accessible web sites. In this study, the visibility of several web-safe color combinations was examined using psychological methodology, i.e., paired comparison. Eighteen chromatic and 3 achromatic web-safe colors were employed for visual stimuli. Twenty-eight subjects ranging from ages 21 to 75 were recruited, and all were with normal color sensation. They looked at two different colored characters simultaneously on the white background and were instructed to identify which one enabled them to see more clearly. In examining the relationship between the psychological rankings of the color combinations and the visual sensations, each color combination was first scored as to the visibility by Thurstone's paired comparison technique. Secondly, the visual sensation was deduced by applying Weber-Fechner's law to the luminance of the foreground colors. As results, the luminance of a foreground color influenced the visibility; however the visibility rating is difficult only using the luminance of web-safe colors. These indicate that the chromaticity and chroma saturation are necessary in rating of chromatic web-safe color visibility.

A Study on Visibility Rating of Several Representative Web-Safe Colors

NASA Astrophysics Data System (ADS)

Saito, Daisuke; Saito, Keiichi; Notomi, Kazuhiro; Saito, Masao

This paper presents the visibility ordering of several web-safe colors. The research of web site visibility is important because of the rapid dissemination of the World Wide Web. The combination of a foreground color and a background color is an important factor in providing sufficient visibility. Therefore, the rating of color combination visibility is necessary when developing accessible web sites. In this study, the visibility of several web-safe color combinations was examined using psychological methodology, i.e., a paired comparison. Eighteen chromatic web-safe colors were employed for visual stimuli. Nine students ranging from ages 21 to 29 (average 23.7) were recruited, and all were with normal color sensation. These nine subjects looked at two different colored characters simultaneously on the white background and were instructed to identify which one enabled them to see more clearly. In examining the relationship between the psychological rankings of the color combinations and the visual sensations, each color combination was first scored as to the visibility by Thurstone's paired comparisons technique. Secondly, the visual sensation was deduced by applying Weber-Fechner's law to the luminance of the foreground colors. As results, the luminance of a foreground color influenced the visibility; however the visibility rating is difficult only using the luminance of web-safe colors. These indicate that the chromaticity and chroma saturation are necessary in rating of chromatic web-safe color visibility.

A proposed protocol for acceptance and constancy control of computed tomography systems: a Nordic Association for Clinical Physics (NACP) work group report.

PubMed

Kuttner, Samuel; Bujila, Robert; Kortesniemi, Mika; Andersson, Henrik; Kull, Love; Østerås, Bjørn Helge; Thygesen, Jesper; Tarp, Ivanka Sojat

2013-03-01

Quality assurance (QA) of computed tomography (CT) systems is one of the routine tasks for medical physicists in the Nordic countries. However, standardized QA protocols do not yet exist and the QA methods, as well as the applied tolerance levels, vary in scope and extent at different hospitals. To propose a standardized protocol for acceptance and constancy testing of CT scanners in the Nordic Region. Following a Nordic Association for Clinical Physics (NACP) initiative, a group of medical physicists, with representatives from four Nordic countries, was formed. Based on international literature and practical experience within the group, a comprehensive standardized test protocol was developed. The proposed protocol includes tests related to the mechanical functionality, X-ray tube, detector, and image quality for CT scanners. For each test, recommendations regarding the purpose, equipment needed, an outline of the test method, the measured parameter, tolerance levels, and the testing frequency are stated. In addition, a number of optional tests are briefly discussed that may provide further information about the CT system. Based on international references and medical physicists' practical experiences, a comprehensive QA protocol for CT systems is proposed, including both acceptance and constancy tests. The protocol may serve as a reference for medical physicists in the Nordic countries.

Measurement of exercise habits and prediction of leisure-time activity in established exercise.

PubMed

Tappe, Karyn A; Glanz, Karen

2013-01-01

Habit formation may be important to maintaining repetitive healthy behaviors like exercise. Existing habit questionnaires only measure part of the definition of habit (automaticity; frequency). A novel habit questionnaire was evaluated that measured contextual cueing. We designed a two-stage observational cohort study of regular exercisers. For stage 1, we conducted an in-person interview on a university campus. For stage 2, we conducted an internet-based survey. Participants were 156 adults exercising at least once per week. A novel measure, The Exercise Habit Survey (EHS) assessed contextual cueing through 13 questions on constancy of place, time, people, and exercise behaviors. A subset of the Self-Report Habit Index (SRHI), measuring automaticity, was also collected along with measures of intention and self-efficacy, and the International Physical Activity Questionnaire (IPAQ), leisure-time section. The EHS was evaluated using factor analysis and test-retest reliability. Its correlation to other exercise predictors and exercise behavior was evaluated using Pearson's r and hierarchical regression. Results suggested that the EHS comprised four subscales (People, Place, Time, Exercise Constancy). Only Exercise Constancy correlated significantly with SRHI. Only the People subscale predicted IPAQ exercise metabolic equivalents. The SRHI was a strong predictor. Contextual cueing is an important aspect of habit but measurement methodologies warrant refinement and comparison by different methods.

Optimizing the temporal dynamics of light to human perception.

PubMed

Rieiro, Hector; Martinez-Conde, Susana; Danielson, Andrew P; Pardo-Vazquez, Jose L; Srivastava, Nishit; Macknik, Stephen L

2012-11-27

No previous research has tuned the temporal characteristics of light-emitting devices to enhance brightness perception in human vision, despite the potential for significant power savings. The role of stimulus duration on perceived contrast is unclear, due to contradiction between the models proposed by Bloch and by Broca and Sulzer over 100 years ago. We propose that the discrepancy is accounted for by the observer's "inherent expertise bias," a type of experimental bias in which the observer's life-long experience with interpreting the sensory world overcomes perceptual ambiguities and biases experimental outcomes. By controlling for this and all other known biases, we show that perceived contrast peaks at durations of 50-100 ms, and we conclude that the Broca-Sulzer effect best describes human temporal vision. We also show that the plateau in perceived brightness with stimulus duration, described by Bloch's law, is a previously uncharacterized type of temporal brightness constancy that, like classical constancy effects, serves to enhance object recognition across varied lighting conditions in natural vision-although this is a constancy effect that normalizes perception across temporal modulation conditions. A practical outcome of this study is that tuning light-emitting devices to match the temporal dynamics of the human visual system's temporal response function will result in significant power savings.

Influence of gender constancy and social power on sex-linked modeling.

PubMed

Bussey, K; Bandura, A

1984-12-01

Competing predictions derived from cognitive-developmental theory and social learning theory concerning sex-linked modeling were tested. In cognitive-developmental theory, gender constancy is considered a necessary prerequisite for the emulation of same-sex models, whereas according to social learning theory, sex-role development is promoted through a vast system of social influences with modeling serving as a major conveyor of sex role information. In accord with social learning theory, even children at a lower level of gender conception emulated same-sex models in preference to opposite-sex ones. Level of gender constancy was associated with higher emulation of both male and female models rather than operating as a selective determinant of modeling. This finding corroborates modeling as a basic mechanism in the sex-typing process. In a second experiment we explored the limits of same-sex modeling by pitting social power against the force of collective modeling of different patterns of behavior by male and female models. Social power over activities and rewarding resources produced cross-sex modeling in boys, but not in girls. This unexpected pattern of cross-sex modeling is explained by the differential sex-typing pressures that exist for boys and girls and socialization experiences that heighten the attractiveness of social power for boys.

Incubation behavior of Spectacled Eiders on the Yukon-Kuskokwim Delta, Alaska

USGS Publications Warehouse

Flint, Paul L.; Grand, J.B.

1999-01-01

We studied incubation behavior of Spectacled Eiders (Somateria fischeri) on the Yukon-Kuskokwim Delta in 1996. We trapped 19 females on their nests and weighed them in early incubation and again at hatch. Average daily weight loss for incubating females was 16.6 ?? 1.0 g day-1, which resulted in a cumulative loss of 26% of body weight throughout incubation. Nest attendance was monitored for a portion of the incubation period using temperature sensing artificial eggs. Incubation constancy averaged 90 ?? 1%. Average recess length was 37.1 ?? 0.9 min, and nests cooled an average of 4.2 ?? 0.1??C during recesses. Recess frequency averaged 2.5 ?? 0.1 recesses day-1, and most recesses (70%) occurred between 10:00 and 22: 00. Incubation constancy varied among females, but was not related to changes in body weight or incubation period. There was no influence of ambient temperature on incubation recess length, however most recesses were taken during the warmest part of the day. We found considerable variation among females in patterns of daily incubation constancy, nest cooling, recess frequency, and recess length. It is not clear from our results what factors constrain incubation behavior of Spectacled Eiders, but we suggest that individual females respond to a complex suite of variables.

Simultaneous optical and IR photometry of the T Tauri star RU LUPI

NASA Astrophysics Data System (ADS)

Giovannelli, F.; Errico, L.; Vittone, A. A.; Rossi, C.

1991-01-01

Two simultaneous optical and IR photometric observation runs of RU Lupi were carried out at the ESO in February 1983 and in June 1986 within the framework of a large multifrequency coordinated campaign of observations. RU Lupi was found in two different states. In the first case the star was in 'quiescence', in the second it was brighter and showed larger variations due to flare like event (FLE). A positive correlation between luminosity and its variations has been found. A Fourier analysis of the light curve available in literature was performed to point out the rotational period. The analysis of these data excludes any periodicity. The color-color diagnostic diagram clearly shows that RU Lupi variability is mainly due to a strong photospheric and chromospheric activity.

Simultaneous Near-Infrared Radiant Heating and UV Radiation for Inactivating Escherichia coli O157:H7 and Salmonella enterica Serovar Typhimurium in Powdered Red Pepper (Capsicum annuum L.)

PubMed Central

Ha, Jae-Won

2013-01-01

This study was conducted to investigate the efficacy of the simultaneous application of near-infrared (NIR) heating and UV irradiation for reducing populations of food-borne pathogens, including Salmonella enterica serovar Typhimurium and Escherichia coli O157:H7 in red pepper powder and to clarify the mechanisms of the lethal effect of the NIR-UV combined treatment. Also, the effect of the combination treatment on quality was determined by measuring changes in color and pungency constituents. Simultaneous NIR-UV combined treatment for 5 min achieved 3.34- and 2.78-log CFU reductions in S. Typhimurium and E. coli O157:H7, respectively, which involved 1.86- and 1.31-log CFU reductions, respectively, which were attributed to the synergistic effect. Through qualitative and quantitative analyses, damage to the cell envelope was identified as the main factor contributing to the synergistic lethal effect of NIR-UV combined treatment. Color values and capsaicin and dihydrocapsaicin content of NIR-UV simultaneously treated red pepper powder were not significantly (P > 0.05) different from those of untreated samples. These results suggest that simultaneous application of NIR and UV treatment can be effectively used to control food-borne pathogens in powdered red pepper without affecting quality. PMID:23956394

Simultaneous near-infrared radiant heating and UV radiation for inactivating Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in powdered red pepper (Capsicum annuum L.).

PubMed

Ha, Jae-Won; Kang, Dong-Hyun

2013-11-01

This study was conducted to investigate the efficacy of the simultaneous application of near-infrared (NIR) heating and UV irradiation for reducing populations of food-borne pathogens, including Salmonella enterica serovar Typhimurium and Escherichia coli O157:H7 in red pepper powder and to clarify the mechanisms of the lethal effect of the NIR-UV combined treatment. Also, the effect of the combination treatment on quality was determined by measuring changes in color and pungency constituents. Simultaneous NIR-UV combined treatment for 5 min achieved 3.34- and 2.78-log CFU reductions in S. Typhimurium and E. coli O157:H7, respectively, which involved 1.86- and 1.31-log CFU reductions, respectively, which were attributed to the synergistic effect. Through qualitative and quantitative analyses, damage to the cell envelope was identified as the main factor contributing to the synergistic lethal effect of NIR-UV combined treatment. Color values and capsaicin and dihydrocapsaicin content of NIR-UV simultaneously treated red pepper powder were not significantly (P > 0.05) different from those of untreated samples. These results suggest that simultaneous application of NIR and UV treatment can be effectively used to control food-borne pathogens in powdered red pepper without affecting quality.

Waiting for O2

NASA Astrophysics Data System (ADS)

Zahnle, K. J.; Catling, D. C.; Claire, M.

2011-12-01

Oxygenic photosynthesis appears to be a necessary condition for the creation of an oxygen-rich atmosphere like Earth's. But available geological and geochemical evidence suggests that oxygenic photosynthesis appeared hundreds of millions of years before the oxygen-rich atmosphere was fully established. The interregnum implies that at least one other necessary condition for O2 had to be met. Here we argue that the second condition was the irreversible oxidation of the surface and crust by hydrogen escape. This is the same cause as it is for other planets with oxidized surfaces, such as Mars. The link between hydrogen escape and oxygen is direct because the primary process in oxygenic photosynthesis is splitting H2O into hydrogen and O2. Gradual oxidation of the surface and crust eventually brought Earth to a tipping point where free O2 became more stable than competing reduced gases such as CH4; or put another way, the system evolved to the point where surface oxidation under a reducing atmosphere could not keep pace with hydrogen escape. Because hydrogen escape is no faster than other geological processes that govern the long-term redox budget of the atmosphere, the approach to oxygen's final triumph would have been fitful and punctuated by episodes of oxygenation, as the record suggests was the case. The duration of the interregnum was determined by the rate of hydrogen escape and by the size of the reduced reservoir that needed to be oxidized before O2 became favored. If hydrogen escape was responsible for O2, it may be possible to account for the rough constancy of del 13C as a rough constancy of the H2/CO2 ratio in volcanic gases that follows from the constancy of the mantle's oxygen fugacity and a rough constancy in the H2O/CO2 ratio in subducted materials.

The effects of heterospecifics and climatic conditions on incubation behavior within a mixed-species colony

USGS Publications Warehouse

Coates, Peter S.; Brussee, Brianne E.; Hothem, Roger L.; Howe, Kristy H.; Casazza, Michael L.; Eadie, John M.

2016-01-01

Parental incubation behavior largely influences nest survival, a critical demographic process in avian population dynamics, and behaviors vary across species with different life history breeding strategies. Although research has identified nest survival advantages of mixing colonies, behavioral mechanisms that might explain these effects is largely lacking. We examined parental incubation behavior using video-monitoring techniques on Alcatraz Island, California, of black-crowned night-heron Nycticorax nycticorax(hereinafter, night-heron) in a mixed-species colony with California gulls Larus californicus and western gulls L. occidentalis. We first quantified general nesting behaviors (i.e. incubation constancy, and nest attendance), and a suite of specific nesting behaviors (i.e. inactivity, vigilance, preening, and nest maintenance) with respect to six different daily time periods. We employed linear mixed effects models to investigate environmental and temporal factors as sources of variation in incubation constancy and nest attendance using 211 nest days across three nesting seasons (2010–2012). We found incubation constancy (percent of time on the eggs) and nest attendance (percent of time at the nest) were lower for nests that were located < 3 m from one or more gull nest, which indirectly supports the predator protection hypothesis, whereby heterospecifics provide protection allowing more time for foraging and other self-maintenance activities. To our knowledge, this is the first empirical evidence of the influence of one nesting species on the incubation behavior of another. We also identified distinct differences between incubation constancy and nest attentiveness, indicating that these biparental incubating species do not share similar energetic constraints as those that are observed for uniparental species. Additionally, we found that variation in incubation behavior was a function of temperature and precipitation, where the strength of these effects was dependent on the time of day. Overall, these findings strengthen our understanding of incubation behavior and nest ecology of a colonial-nesting species.

Preliminary data for the 20 May 1974, simultaneous evaluation of remote sensors experiment. [water pollution monitoring

NASA Technical Reports Server (NTRS)

Johnson, R. W.; Batten, C. E.; Bowker, D. E.; Bressette, W. E.; Grew, G. W.

1975-01-01

Several remote sensors were simultaneously used to collect data over the tidal James River from Hopewell to Norfolk, Virginia. Sensors evaluated included the Multichannel-Ocean Color Sensor, multispectral scanners, and multispectral photography. Ground truth measurements and remotely sensed data are given. Preliminary analysis indicates that suspended sediment and concentrated industrial effluent are observable from all sensors.

Simultaneous fast measurement of circuit dynamics at multiple sites across the mammalian brain

PubMed Central

Kim, Christina K; Yang, Samuel J; Pichamoorthy, Nandini; Young, Noah P; Kauvar, Isaac; Jennings, Joshua H; Lerner, Talia N; Berndt, Andre; Lee, Soo Yeun; Ramakrishnan, Charu; Davidson, Thomas J; Inoue, Masatoshi; Bito, Haruhiko; Deisseroth, Karl

2017-01-01

Real-time activity measurements from multiple specific cell populations and projections are likely to be important for understanding the brain as a dynamical system. Here we developed frame-projected independent-fiber photometry (FIP), which we used to record fluorescence activity signals from many brain regions simultaneously in freely behaving mice. We explored the versatility of the FIP microscope by quantifying real-time activity relationships among many brain regions during social behavior, simultaneously recording activity along multiple axonal pathways during sensory experience, performing simultaneous two-color activity recording, and applying optical perturbation tuned to elicit dynamics that match naturally occurring patterns observed during behavior. PMID:26878381

Granular activated carbon based microbial fuel cell for simultaneous decolorization of real dye wastewater and electricity generation.

PubMed

Kalathil, Shafeer; Lee, Jintae; Cho, Moo Hwan

2011-12-15

Decolorization of dye wastewater before discharge is pivotal because of its immense color and toxicities. In this study, a granular activated carbon based microbial fuel cell (GACB-MFC) was used without using any expensive materials like Nafion membrane and platinum catalyst for simultaneous decolorization of real dye wastewater and bioelectricity generation. After 48 hours of GACB-MFC operation, 73% color was removed at anode and 77% color was removed at cathode. COD removal was 71% at the anode and 76% at the cathode after 48 hours. Toxicity measurements showed that cathode effluent was almost nontoxic after 24 hours. The anode effluent was threefold less toxic compared to original dye wastewater after 48 hours. The GACB-MFC produced a power density of 1.7 W/m(3) with an open circuit voltage 0.45 V. One of the advantages of the GACB-MFC system is that pH was automatically adjusted from 12.4 to 7.2 and 8.0 at the anode and cathode during 48 hours operation. Copyright © 2011 Elsevier B.V. All rights reserved.

Demonstration of KHILS two-color IR projection capability

NASA Astrophysics Data System (ADS)

Jones, Lawrence E.; Coker, Jason S.; Garbo, Dennis L.; Olson, Eric M.; Murrer, Robert Lee, Jr.; Bergin, Thomas P.; Goldsmith, George C., II; Crow, Dennis R.; Guertin, Andrew W.; Dougherty, Michael; Marler, Thomas M.; Timms, Virgil G.

1998-07-01

For more than a decade, there has been considerable discussion about using different IR bands for the detection of low contrast military targets. Theory predicts that a target can have little to no contrast against the background in one IR band while having a discernible signature in another IR band. A significant amount of effort has been invested towards establishing hardware that is capable of simultaneously imaging in two IR bands to take advantage of this phenomenon. Focal plane arrays (FPA) are starting to materialize with this simultaneous two-color imaging capability. The Kinetic Kill Vehicle Hardware-in-the-loop Simulator (KHILS) team of the Air Force Research Laboratory and the Guided Weapons Evaluation Facility (GWEF), both at Eglin AFB, FL, have spent the last 10 years developing the ability to project dynamic IR scenes to imaging IR seekers. Through the Wideband Infrared Scene Projector (WISP) program, the capability to project two simultaneous IR scenes to a dual color seeker has been established at KHILS. WISP utilizes resistor arrays to produce the IR energy. Resistor arrays are not ideal blackbodies. The projection of two IR colors with resistor arrays, therefore, requires two optically coupled arrays. This paper documents the first demonstration of two-color simultaneous projection at KHILS. Agema cameras were used for the measurements. The Agema's HgCdTe detector has responsivity from 4 to 14 microns. A blackbody and two IR filters (MWIR equals 4.2 t 7.4 microns, LWIR equals 7.7 to 13 microns) were used to calibrate the Agema in two bands. Each filter was placed in front of the blackbody one at a time, and the temperature of the blackbody was stepped up in incremental amounts. The output counts from the Agema were recorded at each temperature. This calibration process established the radiance to Agema output count curves for the two bands. The WISP optical system utilizes a dichroic beam combiner to optically couple the two resistor arrays. The transmission path of the beam combiner provided the LWIR (6.75 to 12 microns), while the reflective path produced the MWIR (3 to 6.5 microns). Each resistor array was individually projected into the Agema through the beam combiner at incremental output levels. Once again the Agema's output counts were recorded at each resistor array output level. These projections established the resistor array output to Agema count curves for the MWIR and LWIR resistor arrays. Using the radiance to Agema counts curves, the MWIR and LWIR resistor array output to radiance curves were established. With the calibration curves established, a two-color movie was projected and compared to the generated movie radiance values. By taking care to correctly account for the spectral qualities of the Agema camera, the calibration filters, and the diachroic beam combiner, the projections matched the theoretical calculations. In the near future, a Lockheed- Martin Multiple Quantum Well camera with true two-color IR capability will be tested.

A demonstration of direct access to colored stimuli following cueing by color.

PubMed

Navon, David; Kasten, Ronen

2011-09-01

To test whether cueing by color can affect orienting without first computing the location of the cued color, the impact of reorienting on the validity effect was examined. In Experiment 1 subjects were asked to detect a black dot target presented at random on either of two colored forms. The forms started being presented 750 ms before the onset of a central cue (either an arrow or a colored square). In some proportion of the trials the colors switched locations 150 ms after cue onset, simultaneously with target onset. The color switch was not found to retard responses following a color cue more than following a location cue. Furthermore, it did not reduce the validity effect of the color cue: Though the validity effect of the location cue was quite larger than the validity effect of the color cue, both effects were additive with the presence/absence of a color switch. In Experiment 2, subjects were rather asked to detect a change in shape of one of the colored forms. In this case, color switch was found to affect performance even less following a color cue. The fact that across experiments, color switch did not retard neither responding nor orienting selectively in the color cue condition, indicates that when attention is set to a certain color, reorienting to a new object following color switch does not require re-computing the address of the cued color. That finding is argued to embarrass a strong space-based view of visual attention. Copyright © 2011 Elsevier B.V. All rights reserved.

Theoretical design of multi-colored semi-transparent organic solar cells with both efficient color filtering and light harvesting

PubMed Central

Wen, Long; Chen, Qin; Sun, Fuhe; Song, Shichao; Jin, Lin; Yu, Yan

2014-01-01

Solar cells incorporated with multi-coloring capability not only offer an aesthetic solution to bridge the gap between solar modules and building decorations but also open up the possibility for self-powered colorful display. In this paper, we proposed a multi-colored semi-transparent organic solar cells (TOSCs) design containing metallic nanostructures with the both high color purity and efficiency based on theoretical considerations. By employing guided mode resonance effect, the multi-colored TOSC behave like an efficient color filter that selectively transmits light with the desired wavelengths and generates electricity with light of other wavelengths. Broad range of coloring and luminosity adjusting for the transmission light can be achieved by simply tuning the period and the duty cycle of the metallic nanostructures. Furthermore, accompanying with the efficient color filtering characteristics, the optical absorption of TOSCs was improved due to the marked suppression of transmission loss at the off-resonance wavelengths and the increased light trapping in TOSCs. The mechanisms of the light guiding in photoactive layer and broadband backward scattering from the metallic nanostructures were identified to make an essential contribution to the improved light-harvesting. By enabling efficient color control and high efficiency simultaneously, this approach holds great promise for future versatile photovoltaic energy utilization. PMID:25391756

Divided spatial attention and feature-mixing errors.

PubMed

Golomb, Julie D

2015-11-01

Spatial attention is thought to play a critical role in feature binding. However, often multiple objects or locations are of interest in our environment, and we need to shift or split attention between them. Recent evidence has demonstrated that shifting and splitting spatial attention results in different types of feature-binding errors. In particular, when two locations are simultaneously sharing attentional resources, subjects are susceptible to feature-mixing errors; that is, they tend to report a color that is a subtle blend of the target color and the color at the other attended location. The present study was designed to test whether these feature-mixing errors are influenced by target-distractor similarity. Subjects were cued to split attention across two different spatial locations, and were subsequently presented with an array of colored stimuli, followed by a postcue indicating which color to report. Target-distractor similarity was manipulated by varying the distance in color space between the two attended stimuli. Probabilistic modeling in all cases revealed shifts in the response distribution consistent with feature-mixing errors; however, the patterns differed considerably across target-distractor color distances. With large differences in color, the findings replicated the mixing result, but with small color differences, repulsion was instead observed, with the reported target color shifted away from the other attended color.

Theoretical design of multi-colored semi-transparent organic solar cells with both efficient color filtering and light harvesting.

PubMed

Wen, Long; Chen, Qin; Sun, Fuhe; Song, Shichao; Jin, Lin; Yu, Yan

2014-11-13

Solar cells incorporated with multi-coloring capability not only offer an aesthetic solution to bridge the gap between solar modules and building decorations but also open up the possibility for self-powered colorful display. In this paper, we proposed a multi-colored semi-transparent organic solar cells (TOSCs) design containing metallic nanostructures with the both high color purity and efficiency based on theoretical considerations. By employing guided mode resonance effect, the multi-colored TOSC behave like an efficient color filter that selectively transmits light with the desired wavelengths and generates electricity with light of other wavelengths. Broad range of coloring and luminosity adjusting for the transmission light can be achieved by simply tuning the period and the duty cycle of the metallic nanostructures. Furthermore, accompanying with the efficient color filtering characteristics, the optical absorption of TOSCs was improved due to the marked suppression of transmission loss at the off-resonance wavelengths and the increased light trapping in TOSCs. The mechanisms of the light guiding in photoactive layer and broadband backward scattering from the metallic nanostructures were identified to make an essential contribution to the improved light-harvesting. By enabling efficient color control and high efficiency simultaneously, this approach holds great promise for future versatile photovoltaic energy utilization.

The Control of Single-color and Multiple-color Visual Search by Attentional Templates in Working Memory and in Long-term Memory.

PubMed

Grubert, Anna; Carlisle, Nancy B; Eimer, Martin

2016-12-01

The question whether target selection in visual search can be effectively controlled by simultaneous attentional templates for multiple features is still under dispute. We investigated whether multiple-color attentional guidance is possible when target colors remain constant and can thus be represented in long-term memory but not when they change frequently and have to be held in working memory. Participants searched for one, two, or three possible target colors that were specified by cue displays at the start of each trial. In constant-color blocks, the same colors remained task-relevant throughout. In variable-color blocks, target colors changed between trials. The contralateral delay activity (CDA) to cue displays increased in amplitude as a function of color memory load in variable-color blocks, which indicates that cued target colors were held in working memory. In constant-color blocks, the CDA was much smaller, suggesting that color representations were primarily stored in long-term memory. N2pc components to targets were measured as a marker of attentional target selection. Target N2pcs were attenuated and delayed during multiple-color search, demonstrating less efficient attentional deployment to color-defined target objects relative to single-color search. Importantly, these costs were the same in constant-color and variable-color blocks. These results demonstrate that attentional guidance by multiple-feature as compared with single-feature templates is less efficient both when target features remain constant and can be represented in long-term memory and when they change across trials and therefore have to be maintained in working memory.

Ipsilateral visual illusion after unilateral posterior cerebral artery infarction: a report of two cases.

PubMed

Hong, Yoon Hee; Lim, Tae-Sung; Yong, Suk Woo; Moon, So Young

2010-08-15

In cases of unilateral posterior cerebral artery (PCA) infarction, abnormal visual perception in the ipsilateral visual field, which is usually believed to be intact, is not met frequently and may confuse doctors during evaluation. Recently, we observed two patients who presented with contralateral hemianopsia accompanied by ipsilateral visual illusions after acute unilateral PCA infarctions. Their visual illusion was characterized by zooming in, macropsia or micropsia. These symptoms appeared to be related to deficits in size constancy. Lesions of both patients commonly involved the ipsilateral forceps major. The consistent presentation observed in these two patients suggests that dominance of size constancy can be located in the left hemisphere in some individuals. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Xylocopa bees in tropical coastal sand dunes: use of resources and their floral syndromes.

PubMed

Figueiredo, N; Gimenes, M; de Miranda, M D; Oliveira-Rebouças, P

2013-06-01

Large bees such as species from Xylocopa Latreille are usually associated with pollination in tropical sand dune areas, which frequently present shrubby herbaceous vegetation adapted to conditions of high salinity, high solar radiation and strong winds. We report on the diversity of Xylocopa and the plants they visited to collect nectar and pollen, focusing on the floral syndromes they present in these plants and on the breadth of the trophic niche in a tropical sand dune fragment over the year. The field work was carried out monthly in Baixio (Bahia, Brazil; Northern Coast Environmental Protection Area) from April 2008 to March 2009, over two consecutive days, from 06:30 AM to 05:00 PM. The medium-large body sized Xylocopa (Neoxylocopa) cearensis Ducke and Xylocopa (Schonnherria) subcyanea Pérez were noticeable for their frequency, constancy on the flowers and sharing of plant species. Xylocopa spp. visited plants with flowers of different shapes, colors, inflorescence arrangement and syndromes. However, their resource collections were mainly concentrated on Cuphea brachiata, Waltheria cinerascens, Croton sellowii and Chamaecrista ramosa, which may be considered key species for Xylocopa spp. maintenance in coastal sand dune and restinga environments in Northeast Brazil.

Optical Flow Estimation for Flame Detection in Videos

PubMed Central

Mueller, Martin; Karasev, Peter; Kolesov, Ivan; Tannenbaum, Allen

2014-01-01

Computational vision-based flame detection has drawn significant attention in the past decade with camera surveillance systems becoming ubiquitous. Whereas many discriminating features, such as color, shape, texture, etc., have been employed in the literature, this paper proposes a set of motion features based on motion estimators. The key idea consists of exploiting the difference between the turbulent, fast, fire motion, and the structured, rigid motion of other objects. Since classical optical flow methods do not model the characteristics of fire motion (e.g., non-smoothness of motion, non-constancy of intensity), two optical flow methods are specifically designed for the fire detection task: optimal mass transport models fire with dynamic texture, while a data-driven optical flow scheme models saturated flames. Then, characteristic features related to the flow magnitudes and directions are computed from the flow fields to discriminate between fire and non-fire motion. The proposed features are tested on a large video database to demonstrate their practical usefulness. Moreover, a novel evaluation method is proposed by fire simulations that allow for a controlled environment to analyze parameter influences, such as flame saturation, spatial resolution, frame rate, and random noise. PMID:23613042

Tuning emission color of electroluminescence from two organic interfacial exciplexes by modulating the thickness of middle gadolinium complex layer

NASA Astrophysics Data System (ADS)

Li, Mingtao; Li, Wenlian; Chen, Lili; Kong, Zhiguo; Chu, Bei; Li, Bin; Hu, Zhizhi; Zhang, Zhiqiang

2006-02-01

Electroluminescent colors of organic light-emitting diodes (OLEDs) can be tuned by modulating the thickness of gadolinium (Gd) complex layer sandwiched between an electron-transporting layer (ETL) and a hole-transporting layer (HTL). The emission colors, which originate from the two interfacial exciplexes simultaneously, can be tuned from green to orange by increasing the thickness of the Gd-complex layer. The atom force microscope images have proved that there are many gaps in the thinner Gd-complex layers. Therefore, besides the exciplex formation between Gd complex and HTL, the exciplex between ETL and HTL is also formed. The results demonstrate that a simple way of color tuning can be realized by inserting a thin layer of color tuning material between HTL with lower ionization potentials and ETL with higher electron affinities. Moreover, photovoltaic device and white OLED based on the two exciplexes are also discussed.

Gamut mapping in a high-dynamic-range color space

NASA Astrophysics Data System (ADS)

Preiss, Jens; Fairchild, Mark D.; Ferwerda, James A.; Urban, Philipp

2014-01-01

In this paper, we present a novel approach of tone mapping as gamut mapping in a high-dynamic-range (HDR) color space. High- and low-dynamic-range (LDR) images as well as device gamut boundaries can simultaneously be represented within such a color space. This enables a unified transformation of the HDR image into the gamut of an output device (in this paper called HDR gamut mapping). An additional aim of this paper is to investigate the suitability of a specific HDR color space to serve as a working color space for the proposed HDR gamut mapping. For the HDR gamut mapping, we use a recent approach that iteratively minimizes an image-difference metric subject to in-gamut images. A psychophysical experiment on an HDR display shows that the standard reproduction workflow of two subsequent transformations - tone mapping and then gamut mapping - may be improved by HDR gamut mapping.

High throughput fabrication of large-area plasmonic color filters by soft-X-ray interference lithography.

PubMed

Sun, Libin; Hu, Xiaolin; Wu, Qingjun; Wang, Liansheng; Zhao, Jun; Yang, Shumin; Tai, Renzhong; Fecht, Hans-Jorg; Zhang, Dong-Xian; Wang, Li-Qiang; Jiang, Jian-Zhong

2016-08-22

Plasmonic color filters in mass production have been restricted from current fabrication technology, which impede their applications. Soft-X-ray interference lithography (XIL) has recently generated considerable interest as a newly developed technique for the production of periodic nano-structures with resolution theoretically below 4 nm. Here we ameliorate XIL by adding an order sorting aperture and designing the light path properly to achieve perfect-stitching nano-patterns and fast fabrication of large-area color filters. The fill factor of nanostructures prepared on ultrathin Ag films can largely affect the transmission minimum of plasmonic color filters. By changing the fill factor, the color can be controlled flexibly, improving the utilization efficiency of the mask in XIL simultaneously. The calculated data agree well with the experimental results. Finally, an underlying mechanism has been uncovered after systematically analyzing the localized surface plasmon polaritons (LSPPs) coupling in electric field distribution.

Multistabilities and symmetry-broken one-color and two-color states in closely coupled single-mode lasers.

PubMed

Clerkin, Eoin; O'Brien, Stephen; Amann, Andreas

2014-03-01

We theoretically investigate the dynamics of two mutually coupled, identical single-mode semi-conductor lasers. For small separation and large coupling between the lasers, symmetry-broken one-color states are shown to be stable. In this case the light outputs of the lasers have significantly different intensities while at the same time the lasers are locked to a single common frequency. For intermediate coupling we observe stable symmetry-broken two-color states, where both lasers lase simultaneously at two optical frequencies which are separated by up to 150 GHz. Using a five-dimensional model, we identify the bifurcation structure which is responsible for the appearance of symmetric and symmetry-broken one-color and two-color states. Several of these states give rise to multistabilities and therefore allow for the design of all-optical memory elements on the basis of two coupled single-mode lasers. The switching performance of selected designs of optical memory elements is studied numerically.

Multistabilities and symmetry-broken one-color and two-color states in closely coupled single-mode lasers

NASA Astrophysics Data System (ADS)

Clerkin, Eoin; O'Brien, Stephen; Amann, Andreas

2014-03-01

We theoretically investigate the dynamics of two mutually coupled, identical single-mode semi-conductor lasers. For small separation and large coupling between the lasers, symmetry-broken one-color states are shown to be stable. In this case the light outputs of the lasers have significantly different intensities while at the same time the lasers are locked to a single common frequency. For intermediate coupling we observe stable symmetry-broken two-color states, where both lasers lase simultaneously at two optical frequencies which are separated by up to 150 GHz. Using a five-dimensional model, we identify the bifurcation structure which is responsible for the appearance of symmetric and symmetry-broken one-color and two-color states. Several of these states give rise to multistabilities and therefore allow for the design of all-optical memory elements on the basis of two coupled single-mode lasers. The switching performance of selected designs of optical memory elements is studied numerically.

Simultaneous direct detection of Shiga-toxin producing Escherichia coli (STEC) strains by optical biosensing with oligonucleotide-functionalized gold nanoparticles

NASA Astrophysics Data System (ADS)

Quintela, Irwin A.; de Los Reyes, Benildo G.; Lin, Chih-Sheng; Wu, Vivian C. H.

2015-01-01

A simultaneous direct detection of Shiga-toxin producing strains of E. coli (STEC; ``Big Six'' - O26, O45, O103, O111, O121, and O145) as well as O157 strains by optical biosensing with oligonucleotide-functionalized gold nanoparticles (AuNPs) was developed. Initially, conserved regions of stx genes were amplified by asymmetric polymerase chain reaction (asPCR). Pairs of single stranded thiol-modified oligonucleotides (30-mer) were immobilized onto AuNPs and used as probes to capture regions of stx1 (119-bp) and/or stx2 (104-bp) genes from STEC strains. DNA samples from pure cultures and food samples were sandwich hybridized with AuNP-oligo probes at optimal conditions (50 °C, 30 min). A complex was formed from the hybridization of AuNP-probes and target DNA fragments that retained the initial red color of the reaction solutions. For non-target DNA, a color change from red to purplish-blue was observed following an increase in salt concentration, thus providing the basis of simultaneous direct colorimetric detection of target DNA in the samples. Enrichment and pooling systems were incorporated to efficiently process a large number of food samples (ground beef and blueberries) and detection of live targets. The detection limit was <1 log CFU g-1, requiring less than 1 h to complete after DNA sample preparation with 100% specificity. Gel electrophoresis verified AuNP-DNA hybridization while spectrophotometric data and transmission electron microscope (TEM) images supported color discrimination based on the occurrence of molecular aggregation. In conclusion, the significant features of this approach took advantage of the unique colorimetric properties of AuNPs as a low-cost and simple approach yet with high specificity for simultaneous detection of STEC strains.A simultaneous direct detection of Shiga-toxin producing strains of E. coli (STEC; ``Big Six'' - O26, O45, O103, O111, O121, and O145) as well as O157 strains by optical biosensing with oligonucleotide-functionalized gold nanoparticles (AuNPs) was developed. Initially, conserved regions of stx genes were amplified by asymmetric polymerase chain reaction (asPCR). Pairs of single stranded thiol-modified oligonucleotides (30-mer) were immobilized onto AuNPs and used as probes to capture regions of stx1 (119-bp) and/or stx2 (104-bp) genes from STEC strains. DNA samples from pure cultures and food samples were sandwich hybridized with AuNP-oligo probes at optimal conditions (50 °C, 30 min). A complex was formed from the hybridization of AuNP-probes and target DNA fragments that retained the initial red color of the reaction solutions. For non-target DNA, a color change from red to purplish-blue was observed following an increase in salt concentration, thus providing the basis of simultaneous direct colorimetric detection of target DNA in the samples. Enrichment and pooling systems were incorporated to efficiently process a large number of food samples (ground beef and blueberries) and detection of live targets. The detection limit was <1 log CFU g-1, requiring less than 1 h to complete after DNA sample preparation with 100% specificity. Gel electrophoresis verified AuNP-DNA hybridization while spectrophotometric data and transmission electron microscope (TEM) images supported color discrimination based on the occurrence of molecular aggregation. In conclusion, the significant features of this approach took advantage of the unique colorimetric properties of AuNPs as a low-cost and simple approach yet with high specificity for simultaneous detection of STEC strains. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr05869k

Simultaneous Photometric and Spectroscopic Solution for AW Cam

NASA Astrophysics Data System (ADS)

Frey, J. R.; Angione, R. J.; Sievers, J. R.

2010-07-01

We present the first four color Stromgren uvby photometric observations of the eclipsing binary system AW Cam along with the first simultaneous photometric and spectroscopic solution. This solution produced a detached system with a mass ratio of 0.45 consisting of an A1 primary and an F8 secondary, both in the main sequence band. The Hipparcos/Tycho Catalogue gives V = 8.24 and a parallax = 2.17 mas.

Geologic interpretation of HCMM and aircraft thermal data

NASA Technical Reports Server (NTRS)

1982-01-01

Progress on the Heat Capacity Mapping Mission (HCMM) follow-on study is reported. Numerous image products for geologic interpretation of both HCMM and aircraft thermal data were produced. These include, among others, various combinations of the thermal data with LANDSAT and SEASAT data. The combined data sets were displayed using simple color composites, principal component color composites and black and white images, and hue, saturation intensity color composites. Algorithms for incorporating both atmospheric and elevation data simultaneously into the digital processing for creation of quantitatively correct thermal inertia images, are in the final development stage. A field trip to Death Valley was undertaken to field check the aircraft and HCMM data.

Monolithic multi-color light emission/detection device

DOEpatents

Wanlass, Mark W.

1995-01-01

A single-crystal, monolithic, tandem, multi-color optical transceiver device is described, including (a) an InP substrate having upper and lower surfaces, (b) a first junction on the upper surface of the InP substrate, (c) a second junction on the first junction. The first junction is preferably GaInAsP of defined composition, and the second junction is preferably InP. The two junctions are lattice matched. The second junction has a larger energy band gap than the first junction. Additional junctions having successively larger energy band gaps may be included. The device is capable of simultaneous and distinct multi-color emission and detection over a single optical fiber.

Using SysRem as an Alternative Photometry Technique

NASA Astrophysics Data System (ADS)

Marshall, S.; Williams, J.; Mazeh, T.; Walker, G.; Strelnitski, V.

2010-02-01

In SysRem, a statistical photometric algorithm for the search for new variable objects (Tamuz et al. 2005; Mazeh et al. 2007), the correction for systematic errors for star i on frame j is expressed as the product of two coefficients, a_j and c_i. SysRem introduces some distortion to the light curves, because unknown variations of variable objects influence c_i and a_j. Shporer et al. (2007) applied SysRem for photometry of a known star with transiting planet, WASP-1b. To minimize the influence of target's variability, only the comparison stars were used for finding a_j; then c_t for the target was determined by minimizing the residuals from the best fitting model of the transit. We investigated further the possibility of using modified SysRem for precise photometry of known targets. Here we report on the results obtained with a version similar to that used by Shporer et al. (2007, hereafter ``SysRem-ph''). The target was a constant V = 11.12 star from Landolt cluster SA98 (Landolt 1992). Observations were performed on the 0.6-m MMO reflector with the Princeton Instruments E2V, 512× 512, CCD camera, on two nights, with filters V (74 frames) and I (76 frames), with 90 s and 40 s exposures per frame, respectively. The reductions were made by JW and GW. JW compared SysRem-ph with the ``grey'' differential photometry (in which the differences in colors and positions of stars are not taken into account) and with the regular SysRem, and GW - the results of ``grey'' and ``color'' differential photometry (Hardie 1962). Eight comparison stars were used by JW and 12 by GW. The results for the four data sets can be summarized as follows: (1) Regular SysRem produced standard deviations (STDEV) of 3-5 mmag, close to the predicted photon noise (≈ 4 mmag); (2) SysRem-ph gave larger STDEV than regular SysRem (by 0.8-0.9 mmag) but smaller than ``grey'' photometry (by 0.5-1.6 mmag); and (3) ``Color'' differential photometry was better than ``grey'' photometry by 1-2 mmag. We conclude that for one-color photometry of variable objects with identifiable periods of constancy, SysRem-ph can be a good alternative to the traditional ``grey'' differential photometry. The higher precision of SysRem-ph is due to the capability of SysRem to account for the differences in color and position of the involved stars, without prior knowledge of these differences (Mazeh et al. 2007).

Development of a PC interface board for true color control using an Ar Kr white-light laser

NASA Astrophysics Data System (ADS)

Shin, Yongjin; Park, Sohee; Kim, Youngseop; Lee, Jangwoen

2006-06-01

For the optimal laser display, it is crucial to select and control color signals of proper wavelengths in order to construct a wide range of laser display colors. In traditional laser display schemes, color control has been achieved through the mechanical manipulation of red, green, and blue (RGB) laser beam intensities using color filters. To maximize the effect of a laser display and its color contents, it is desirable to generate laser beams with wide selection of wavelengths. We present an innovative laser display control technique, which generates six channel laser wavelengths from a white-light laser using a RF-controlled polychromatic acousto optical modulator (PCAOM). This technique enables us not only to control the intensity of individual channels, but also to achieve true color signals for the laser beam display including RGB, yellow, cyan, and violet (YCV), and other intermediate colors. For the optimal control of the PCAOM and galvano-mirror, we designed and fabricated a PC interface board. Using this PC control, we separated the white-light from an Ar-Kr mixed gas laser into various wavelengths and reconstructed them into different color schemes. Also we demonstrated the effective control and simultaneous display of reconstructed true color laser beams on a flat screen.

Correlated photometric and polarimetric phenomena in AM Herculis

NASA Technical Reports Server (NTRS)

Priedhorsky, W. C.; Krzeminski, W.; Tapia, S.

1978-01-01

Via simultaneous multicolor photometry and polarimetry of AM Herculis, we find correlations among polarization, flux, and color in the V and I bands in periodic and nonperiodic (i.e., flickering) activity. The primary minimum observed in both bands is accompanied by a blueward shift of the (B - R) color and a decrease in the absolute value of the percent circular polarization in the V band. Outside primary minimum, peaks of flickering activity tend to be associated with an increase in the absolute value of the circular polarization and the concurrent reddening of the (B - R) and (R - I) colors. The visual light curve of AM Her can be explained by a flickering, circularly polarized light source which is obscured at primary minimum, and is redder than the total system color in the URVRI bands.

3D-shape of objects with straight line-motion by simultaneous projection of color coded patterns

NASA Astrophysics Data System (ADS)

Flores, Jorge L.; Ayubi, Gaston A.; Di Martino, J. Matías; Castillo, Oscar E.; Ferrari, Jose A.

2018-05-01

In this work, we propose a novel technique to retrieve the 3D shape of dynamic objects by the simultaneous projection of a fringe pattern and a homogeneous light pattern which are both coded in two of the color channels of a RGB image. The fringe pattern, red channel, is used to retrieve the phase by phase-shift algorithms with arbitrary phase-step, while the homogeneous pattern, blue channel, is used to match pixels from the test object in consecutive images, which are acquired at different positions, and thus, to determine the speed of the object. The proposed method successfully overcomes the standard requirement of projecting fringes of two different frequencies; one frequency to extract object information and the other one to retrieve the phase. Validation experiments are presented.

Quantum well infrared photodetector simultaneously working in the two atmospheric windows

NASA Astrophysics Data System (ADS)

Huo, Y. H.; Ma, W. Q.; Zhang, Y. H.; Chong, M.; Yang, T.; Chen, L. H.; Shi, Y. L.

2009-07-01

We have demonstrated a dual-band quantum well infrared photodetector (QWIP) exhibiting simultaneous photoresponse both in the mid and the long wavelength atmospheric windows of 3-5 μm and of 8-12 μm, but the device only has two ohmic contacts. The structure of the device was achieved by sequentially growing a mid wavelength part (MWQWIP) followed by a long wavelength part (LWQWIP) separated by an n+ layer. Comparing with the conventional dual-band QWIP device utilizing three ohmic contacts, our QWIP is promising to greatly facilitate the two-color focal plane array (FPA) fabrication by reducing the number of the indium bump per pixel from three to one just like a monochromatic FPA fabrication; another advantage may be that this QWIP FAP boasts two-color detection capability while only using a monochromatic readout integrated circuit.

Preparation of drinking water used in water supply systems of the towns Zrenjanin and Temerin by electrochemical methods.

PubMed

Orescanin, Visnja; Kollar, Robert; Nad, Karlo; Mikulic, Nenad

2013-01-01

The aim of this work was the development and application of the pilot plant with the capacity of 1000 L/day for the purification of groundwater used for human consumption characterized with high concentration of arsenic and increased values of organic pollutants, ammonia, nitrites, color and turbidity. For that purpose, groundwater from the production wells supplying the towns Zrenjanin and Temerin (Vojvodina, Serbia) was used. Due to its complex composition, the purification system required the combination of the electroreduction/electrocoagulation, using iron and aluminum electrode plates with/without ozonation, followed by the electromagnetic treatment and the finally by the simultaneous ozonation/UV treatment. The electroreduction was used for the removal of nitrates, nitrites, and Cr(VI), while the removal of arsenic, heavy metals, suspended solids, color and turbidity required the application of the electrocoagulation with simultaneous ozonation. Organic contaminants and ammonia were removed completely in the last treatment step by applying the simultaneous ozonation/UV treatment. All measured parameters in the purified water were significantly lower compared to the regulated values. Under the optimum treatment conditions, the removal efficiencies for color, turbidity, suspended solids, total arsenic, total chromium, Ni(II), total copper, sulfates, fluorides, chemical oxygen demand, ammonia, nitrates, and nitrites were 100%. The removal efficiencies of the total manganese and iron were 85.19% and 97.44%, respectively, whilst the final concentrations were 4 and 7 μg/L, respectively.

[Simultaneous determination of 6 forbidden colorants in cosmetics by high performance liquid chromatography-tandem mass spectrometry].

PubMed

Lin, Weixuan; Sun, Xingquan; Zhao, Xuerong; Xu, Wei; Guo, Guiyuan

2012-05-01

A method of high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has been established for the simultaneous determination of six forbidden colorants including Sudan IV, Acid Violet 49, Sudan Blue 2, Solvent Red 49, Basic Violet 1 and Pigment Orange 5 in cream and powdery matrix cosmetics. The samples were extracted with ethanol-acetonitrile (3:2, v/v) solution by ultrasonic technique for 20 min, then centrifuged for purification and enriched by nitrogen blowing sequentially. The analytes were isolated on a Luna C18 column (150 mm x 2.1 mm, 5 microm) by gradient elution with methanol and 10 mmol/L ammonium acetate as the mobile phases, and detected by MS/MS in the multiple reaction monitoring (MRM) mode. The qualitative analysis was based on the retention time and the relative abundance ratio of the characteristic ions, and the quantitative analysis on calibration curve method. The results showed that the limits of quantification (LOQ, S/N= 10) of the six colorants ranged from 0.1 to 10 microg/kg and the average recoveries were from 86.67% to 98.22% with the relative standard deviations (RSDs) from 4.01% to 7.01%. The method is simple and rapid with high sensitivity and good reproducibility, and suitable for the determination of the six forbidden colorants in cosmetics.

A novel and easy FxCycle™ violet based flow cytometric method for simultaneous assessment of DNA ploidy and six-color immunophenotyping.

PubMed

Tembhare, Prashant; Badrinath, Yajamanam; Ghogale, Sitaram; Patkar, Nikhil; Dhole, Nilesh; Dalavi, Pooja; Kunder, Nikesh; Kumar, Ashok; Gujral, Sumeet; Subramanian, P G

2016-03-01

Abnormal DNA ploidy is a valuable prognostic factor in many neoplasms, especially in hematological neoplasms like B-cell acute lymphoblastic leukemia (B-ALL) and multiple myeloma (MM). Current methods of flow-cytometric (FC) DNA-ploidy evaluation are either technically difficult or limited to three- to four-color immunophenotyping and hence, challenging to evaluate DNA-ploidy in minute tumor population with background rich of its normal counterpart cells and other hematopoietic cells. We standardized a novel sensitive and easy method of simultaneous evaluation of six- to seven-color immunophenotyping and DNA-ploidy using a dye-FxCycle Violet (FCV). Linearity, resolution, and coefficient of variation (CV) for FCV were studied using chicken erythrocyte nuclei. Ploidy results of FCV were compared with Propidium iodide (PI) in 20 samples and intra-assay variation for FCV was studied. Using this six-color immunophenotyping & FCV-protocol DNA-ploidy was determined in bone-marrow samples from 124 B-ALL & 50 MM patients. Dilution experiment was also conducted to determine the sensitivity in detection of aneuploidy in minute tumor population. FCV revealed high linearity and resolution in 450/50 channel. On comparison with PI, CV of Go/G1-peak with FCV (mean-CV 4.1%) was slightly higher than PI (mean-CV 2.9%) but had complete agreement in ploidy results. Dilution experiment showed that aneuploidy could be accurately detected up to the limit of 0.01% tumor cells. Intra-assay variation was very low with CV of 0.005%. In B-ALL, hypodiploidy was noted in 4%, hyperdiploidy in 24%, near-hyperdiploidy in 13% and remaining 59% were diploid. In MM, hypodiploidy was in 2%, hyperdiploidy in 58%, near-hyperdiploidy in 8% and remaining 30% were diploid. FCV-based DNA-ploidy method is a sensitive and easy method for simultaneous evaluation of six-color immunophenotyping and DNA analysis. It is useful in DNA-ploidy evaluation of minute tumor population in cases like minimal residual disease and MM precursor conditions. © 2015 International Society for Advancement of Cytometry.

New yellow Ba 0.93Eu 0.07Al 2O 4 phosphor for warm-white light-emitting diodes through single-emitting-center conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xufan; Budai, John D.; Liu, Feng

2013-01-01

Phosphor-converted white light-emitting diodes for indoor illumination need to be warm-white (i.e., correlated color temperature <4000 K) with good color rendition (i.e., color rendering index >80). However, no single-phosphor, single-emitting-center-converted white light-emitting diodes can simultaneously satisfy the color temperature and rendition requirements due to the lack of sufficient red spectral component in the phosphors’ emission spectrum. Here, we report a new yellow Ba 0.93Eu 0.07Al 2O 4 phosphor that has a new orthorhombic lattice structure and exhibits a broad yellow photoluminescence band with sufficient red spectral component. Warm-white emissions with correlated color temperature <4000 K and color rendering index >80more » were readily achieved when combining the Ba 0.93Eu 0.07Al 2O 4 phosphor with a blue light-emitting diode (440–470 nm). This study demonstrates that warm-white light-emitting diodes with high color rendition (i.e., color rendering index >80) can be achieved based on single-phosphor, single-emitting-center conversion.« less

Seasonal and habitat-related distribution pattern of Synechococcus genotypes in Lake Constance.

PubMed

Becker, Sven; Richl, Petra; Ernst, Anneliese

2007-10-01

The abundance and distribution of Synechococcus spp. in the autotrophic picoplankton of Lake Constance, were followed in the pelagic and littoral habitat by qPCR over 2 years. One genotype, represented by isolated phycoerythrin-rich strain BO 8807, showed a seasonal distribution pattern in both habitats. Before a stable thermal stratification, the maximum of both the Synechococcus population and genotype BO 8807 occurred at 15 or 20 m water depth in the pelagic habitat. During the summer stratification, when the absolute abundance of all Synechococcus spp. was highest above 15 m, the absolute and relative abundance of genotype BO 8807 was maximal at 20 m. These results indicate that Synechococcus spp. or single genotypes are present in deep maxima in Lake Constance. The in situ dynamics of genotype BO 8807 is consistent with the observation that isolated strain BO 8807 requires higher phosphate concentrations for maximum growth rates than a strain from the same phylogenetic cluster that dominates the pelagic summer population. In contrast to these findings, low genome numbers of phycocyanin-rich genotype BO 8805 were found temporarily only in both the littoral and pelagic plankton. Microscopy revealed that PC-rich cells in general occurred preferentially in the littoral habitat. We discuss our results with respect to the versatility of picocyanobacteria of the evolutionary lineage VI of cyanobacteria, and a habitat-related distribution pattern of Synechococcus genotypes.

Causality and headache triggers

PubMed Central

Turner, Dana P.; Smitherman, Todd A.; Martin, Vincent T.; Penzien, Donald B.; Houle, Timothy T.

2013-01-01

Objective The objective of this study was to explore the conditions necessary to assign causal status to headache triggers. Background The term “headache trigger” is commonly used to label any stimulus that is assumed to cause headaches. However, the assumptions required for determining if a given stimulus in fact has a causal-type relationship in eliciting headaches have not been explicated. Methods A synthesis and application of Rubin’s Causal Model is applied to the context of headache causes. From this application the conditions necessary to infer that one event (trigger) causes another (headache) are outlined using basic assumptions and examples from relevant literature. Results Although many conditions must be satisfied for a causal attribution, three basic assumptions are identified for determining causality in headache triggers: 1) constancy of the sufferer; 2) constancy of the trigger effect; and 3) constancy of the trigger presentation. A valid evaluation of a potential trigger’s effect can only be undertaken once these three basic assumptions are satisfied during formal or informal studies of headache triggers. Conclusions Evaluating these assumptions is extremely difficult or infeasible in clinical practice, and satisfying them during natural experimentation is unlikely. Researchers, practitioners, and headache sufferers are encouraged to avoid natural experimentation to determine the causal effects of headache triggers. Instead, formal experimental designs or retrospective diary studies using advanced statistical modeling techniques provide the best approaches to satisfy the required assumptions and inform causal statements about headache triggers. PMID:23534872

Color inference in visual communication: the meaning of colors in recycling.

PubMed

Schloss, Karen B; Lessard, Laurent; Walmsley, Charlotte S; Foley, Kathleen

2018-01-01

People interpret abstract meanings from colors, which makes color a useful perceptual feature for visual communication. This process is complicated, however, because there is seldom a one-to-one correspondence between colors and meanings. One color can be associated with many different concepts (one-to-many mapping) and many colors can be associated with the same concept (many-to-one mapping). We propose that to interpret color-coding systems, people perform assignment inference to determine how colors map onto concepts. We studied assignment inference in the domain of recycling. Participants saw images of colored but unlabeled bins and were asked to indicate which bins they would use to discard different kinds of recyclables and trash. In Experiment 1, we tested two hypotheses for how people perform assignment inference. The local assignment hypothesis predicts that people simply match objects with their most strongly associated color. The global assignment hypothesis predicts that people also account for the association strengths between all other objects and colors within the scope of the color-coding system. Participants discarded objects in bins that optimized the color-object associations of the entire set, which is consistent with the global assignment hypothesis. This sometimes resulted in discarding objects in bins whose colors were weakly associated with the object, even when there was a stronger associated option available. In Experiment 2, we tested different methods for encoding color-coding systems and found that people were better at assignment inference when color sets simultaneously maximized the association strength between assigned color-object parings while minimizing associations between unassigned pairings. Our study provides an approach for designing intuitive color-coding systems that facilitate communication through visual media such as graphs, maps, signs, and artifacts.

Terrestrial passage theory of the moon illusion.

PubMed

Reed, C F

1984-12-01

Theories of the celestial, or moon, illusion have neglected geometric characteristics of movement along and above the surface of the earth. The illusion occurs because the characteristics of terrestrial passage are attributed to celestial passage. In terrestrial passage, the visual angle subtended by an object changes discriminably as an essentially invariant function of elevation above the horizon. In celestial passage, by contrast, change in visual angle is indiscriminable at all elevations. If a terrestrial object gains altitude, its angular subtense fails to follow the expansion projected for an orbital course: Angular diminution or constancy is equivalent to distancing. On the basis of terrestrial projections, a similar failure of celestial objects in successive elevations is also equivalent to distancing. The illusion occurs because of retinal image constancy, not--as traditionally stated--despite it.

Inconstancy in predator/prey ratios in Quaternary large mammal communities of Italy, with an appraisal of mechanisms

NASA Astrophysics Data System (ADS)

Raia, Pasquale; Meloro, Carlo; Barbera, Carmela

2007-03-01

Constancy in predator/prey ratio (PPR) is a controversial issue in ecological research. Published reports support both constancy and inconstancy of the ratio in animal communities. Only a few studies, however, specifically address its course through time. Here we study the course of predator/prey ratio in communities of large Plio-Pleistocene mammals in Italy. After controlling for taphonomic biases, we find strong support for PPR inconstancy through time. Extinction, dispersal events, and differences in body size trends between predators and their prey were found to affect the ratio, which was distributed almost bimodally. We suggest that this stepwise dynamic in PPR indicates changes in ecosystem functioning. Prey richness was controlled by predation when PPR was high and by resources when PPR was low.

Behavioral research in pigeons with ARENA: An automated remote environmental navigation apparatus

PubMed Central

Leising, Kenneth J.; Garlick, Dennis; Parenteau, Michael; Blaisdell, Aaron P.

2009-01-01

Three experiments established the effectiveness of an Automated Remote Environmental Navigation Apparatus (ARENA) developed in our lab to study behavioral processes in pigeons. The technology utilizes one or more wireless modules, each capable of presenting colored lights as visual stimuli to signal reward and of detecting subject peck responses. In Experiment 1, subjects were instrumentally shaped to peck at a single ARENA module following an unsuccessful autoshaping procedure. In Experiment 2, pigeons were trained with a simultaneous discrimination procedure during which two modules were illuminated different colors; pecks to one color (S+) were reinforced while pecks to the other color (S−) were not. Pigeons learned to preferentially peck the module displaying the S+. In Experiment 3, two modules were lit the same color concurrently from a set of six colors in a conditional discrimination task. For three of the colors pecks to the module in one location (e.g., upper quadrant) were reinforced while for the remaining colors pecks at the other module (e.g., lower quadrant) were reinforced. After learning this discrimination, the color-reinforced location assignments were reversed. Pigeons successfully acquired the reversal. ARENA is an automated system for open-field studies and a more ecologically valid alternative to the touchscreen. PMID:19429204

Spatio-spectral color filter array design for optimal image recovery.

PubMed

Hirakawa, Keigo; Wolfe, Patrick J

2008-10-01

In digital imaging applications, data are typically obtained via a spatial subsampling procedure implemented as a color filter array-a physical construction whereby only a single color value is measured at each pixel location. Owing to the growing ubiquity of color imaging and display devices, much recent work has focused on the implications of such arrays for subsequent digital processing, including in particular the canonical demosaicking task of reconstructing a full color image from spatially subsampled and incomplete color data acquired under a particular choice of array pattern. In contrast to the majority of the demosaicking literature, we consider here the problem of color filter array design and its implications for spatial reconstruction quality. We pose this problem formally as one of simultaneously maximizing the spectral radii of luminance and chrominance channels subject to perfect reconstruction, and-after proving sub-optimality of a wide class of existing array patterns-provide a constructive method for its solution that yields robust, new panchromatic designs implementable as subtractive colors. Empirical evaluations on multiple color image test sets support our theoretical results, and indicate the potential of these patterns to increase spatial resolution for fixed sensor size, and to contribute to improved reconstruction fidelity as well as significantly reduced hardware complexity.

A New Two-Color Infrared Photodetector Design Using INGAAS/INALAS Coupled Quantum Wells

DTIC Science & Technology

1999-08-01

that spans the mid-wave infrared (MWIR) and the long-wave infrared ( LWIR ) atmospheric transmission windows of 3 to 5 and 8 to 12 µm, respectively...This leads to natural pixel registration in an FPA application. QWIP FPAs operating in two LWIR bands have been demonstrated,2 and, recently, the...Abstract unlimited Number of Pages 15 color FPA with simultaneous readout of an LWIR (9-µm peak) and an MWIR (5.1-µm peak) band was tested3 and shown to

Dual-color three-dimensional STED microscopy with a single high-repetition-rate laser

PubMed Central

Han, Kyu Young; Ha, Taekjip

2016-01-01

We describe a dual-color three-dimensional stimulated emission depletion (3D-STED) microscopy employing a single laser source with a repetition rate of 80 MHz. Multiple excitation pulses synchronized with a STED pulse were generated by a photonic crystal fiber and the desired wavelengths were selected by an acousto-optic tunable filter with high spectral purity. Selective excitation at different wavelengths permits simultaneous imaging of two fluorescent markers at a nanoscale resolution in three dimensions. PMID:26030581

Investigation of crack initiation with a three color digital holographic interferometer

NASA Astrophysics Data System (ADS)

Karray, Mayssa; Poilane, Christophe; Mounier, Denis; Gargoury, Mohamed; Picart, Pascal

2012-10-01

This paper proposes a three-color holographic interferometer devoted to the deformation analysis of a composite material submitted to a short beam shear test. The simultaneous recording of three laser wavelengths using a triple CCD sensor results in the evaluation of shear strains at the lateral surface of the sample. Such an evaluation provides a pertinent parameter to detect premature crack in the structure, long before it becomes visible on the real time stress/strain curve, or with a classical microscope.

A simulation study on the constancy of cardiac energy metabolites during workload transition.

PubMed

Saito, Ryuta; Takeuchi, Ayako; Himeno, Yukiko; Inagaki, Nobuya; Matsuoka, Satoshi

2016-12-01

The cardiac energy metabolites such as ATP, phosphocreatine, ADP and NADH are kept relatively constant during physiological cardiac workload transition. How this is accomplished is not yet clarified, though Ca 2+ has been suggested to be one of the possible mechanisms. We constructed a detailed mathematical model of cardiac mitochondria based on experimental data and studied whether known Ca 2+ -dependent regulation mechanisms play roles in the metabolite constancy. Model simulations revealed that the Ca 2+ -dependent regulation mechanisms have important roles under the in vitro condition of isolated mitochondria where malate and glutamate were mitochondrial substrates, while they have only a minor role and the composition of substrates has marked influence on the metabolite constancy during workload transition under the simulated in vivo condition where many substrates exist. These results help us understand the regulation mechanisms of cardiac energy metabolism during physiological cardiac workload transition. The cardiac energy metabolites such as ATP, phosphocreatine, ADP and NADH are kept relatively constant over a wide range of cardiac workload, though the mechanisms are not yet clarified. One possible regulator of mitochondrial metabolism is Ca 2+ , because it activates several mitochondrial enzymes and transporters. Here we constructed a mathematical model of cardiac mitochondria, including oxidative phosphorylation, substrate metabolism and ion/substrate transporters, based on experimental data, and studied whether the Ca 2+ -dependent activation mechanisms play roles in metabolite constancy. Under the in vitro condition of isolated mitochondria, where malate and glutamate were used as mitochondrial substrates, the model well reproduced the Ca 2+ and inorganic phosphate (P i ) dependences of oxygen consumption, NADH level and mitochondrial membrane potential. The Ca 2+ -dependent activations of the aspartate/glutamate carrier and the F 1 F o -ATPase, and the P i -dependent activation of Complex III were key factors in reproducing the experimental data. When the mitochondrial model was implemented in a simple cardiac cell model, simulation of workload transition revealed that cytoplasmic Ca 2+ concentration ([Ca 2+ ] cyt ) within the physiological range markedly increased NADH level. However, the addition of pyruvate or citrate attenuated the Ca 2+ dependence of NADH during the workload transition. Under the simulated in vivo condition where malate, glutamate, pyruvate, citrate and 2-oxoglutarate were used as mitochondrial substrates, the energy metabolites were more stable during the workload transition and NADH level was almost insensitive to [Ca 2+ ] cyt . It was revealed that mitochondrial substrates have a significant influence on metabolite constancy during cardiac workload transition, and Ca 2+ has only a minor role under physiological conditions. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Evaluation of Ocean Color Scanner (OCS) photographic and digital data: Santa Barbara Channel test site, 29 October 1975 overflight

NASA Technical Reports Server (NTRS)

Kraus, S. P.; Estes, J. E.; Kronenberg, M. R.; Hajic, E. J.

1977-01-01

A summary of Ocean Color Scanner data was examined to evaluate detection and discrimination capabilities of the system for marine resources, oil pollution and man-made sea surface targets of opportunity in the Santa Barbara Channel. Assessment of the utility of OCS for the determination of sediment transport patterns along the coastal zone was a secondary goal. Data products provided 1975 overflight were in digital and analog formats. In evaluating the OCS data, automated and manual procedures were employed. A total of four channels of data in digital format were analyzed, as well as three channels of color combined imagery, and four channels of black and white imagery. In addition, 1:120,000 scale color infrared imagery acquired simultaneously with the OCS data were provided for comparative analysis purposes.

Modulation-frequency encoded multi-color fluorescent DNA analysis in an optofluidic chip.

PubMed

Dongre, Chaitanya; van Weerd, Jasper; Besselink, Geert A J; Vazquez, Rebeca Martinez; Osellame, Roberto; Cerullo, Giulio; van Weeghel, Rob; van den Vlekkert, Hans H; Hoekstra, Hugo J W M; Pollnau, Markus

2011-02-21

We introduce a principle of parallel optical processing to an optofluidic lab-on-a-chip. During electrophoretic separation, the ultra-low limit of detection achieved with our set-up allows us to record fluorescence from covalently end-labeled DNA molecules. Different sets of exclusively color-labeled DNA fragments-otherwise rendered indistinguishable by spatio-temporal coincidence-are traced back to their origin by modulation-frequency-encoded multi-wavelength laser excitation, fluorescence detection with a single ultrasensitive, albeit color-blind photomultiplier, and Fourier analysis decoding. As a proof of principle, fragments obtained by multiplex ligation-dependent probe amplification from independent human genomic segments, associated with genetic predispositions to breast cancer and anemia, are simultaneously analyzed.

Temperature measurements of micro-droplets using pulsed 2-color laser-induced fluorescence with MDR-enhanced energy transfer

NASA Astrophysics Data System (ADS)

Palmer, Johannes; Reddemann, Manuel A.; Kirsch, Valeri; Kneer, Reinhold

2016-12-01

In this work, a new measurement system is presented for studying temperature of micro-droplets by pulsed 2-color laser-induced fluorescence. Pulsed fluorescence excitation allows motion blur suppression and thus simultaneous measurements of droplet size, velocity and temperature. However, high excitation intensities of pulsed lasers lead to morphology-dependent resonances inside micro-droplets, which are accompanied by disruptive stimulated emission. Investigations showed that stimulated emission can be avoided by enhanced energy transfer via an additional dye. The suitability and accuracy of the new pulsed method are verified on the basis of a spectroscopic analysis and comparison to continuously excited 2-color laser-induced fluorescence.

Monolithic multi-color light emission/detection device

DOEpatents

Wanlass, M.W.

1995-02-21

A single-crystal, monolithic, tandem, multi-color optical transceiver device is described, including (a) an InP substrate having upper and lower surfaces, (b) a first junction on the upper surface of the InP substrate, (c) a second junction on the first junction. The first junction is preferably GaInAsP of defined composition, and the second junction is preferably InP. The two junctions are lattice matched. The second junction has a larger energy band gap than the first junction. Additional junctions having successively larger energy band gaps may be included. The device is capable of simultaneous and distinct multi-color emission and detection over a single optical fiber. 5 figs.

Accounting for the water-leaving radiance in the simultaneous retrieval of atmosphere and ocean properties from collocated polarimeters and lidar measurements: results for the SABOR campaign

NASA Astrophysics Data System (ADS)

Chowdhary, J.; Brian, C.; Stamnes, S.; Hostetler, C. A.; Cetinic, I.; Slade, W. H.; Hu, Y.

2017-12-01

Ocean spectra typically contribute less than 10% to top-of-atmosphere (TOA) radiance observations in the visible (VIS). The remaining 90% of TOA radiance originates from scattering in the atmosphere which needs to be removed (i.e. corrected) but varies substantially with the aerosol present at the time of observation. The traditional approach for atmospheric correction (AC), used for ocean color sensors such as SeaWiFS, MODIS, and VIIRS, estimates aerosol scattering properties from TOA radiance observations in the near-infrared/short-wave infrared (NIR/SWIR) where the ocean becomes dark. The aerosol model is subsequently used to compute the atmospheric scattering contribution to the TOA radiance in the VIS. The final step is to subtract this computed scattering contribution from the real (i.e. observed) TOA radiance. As an alternative to the traditional approach for AC, we retrieve the atmosphere (i.e., aerosol) and ocean (i.e., color) properties simultaneously from measurements in the VIS. To separate the information content for the atmosphere and ocean, we use lidar measurements and multi-angle polarization measurements. Lidar and polarimeter measurements are powerful tools to enhance the ocean product retrievals from conventional ocean color sensors, and are under consideration to accompany future generation ocean color sensors. Here, we present results of simultaneous atmosphere-ocean retrievals using collocated airborne lidar and polarimeter data that were acquired during the Ship-Aircraft Bio-Optical Research (SABOR) campaign. We discuss 2 hydrosol models (which differ in number of free parameters) that were used for these inversions. We then compare our ocean retrievals with measurements obtained from the accompanying cruise ship. Finally, we touch upon a next generation of hydrosol models that accommodates the unique sensitivity of ocean lidar profiles to plankton morphology.

Accurate chromatic control and color rendering optimization in LED lighting systems using junction temperature feedback

NASA Astrophysics Data System (ADS)

Sisto, Marco Michele; Gauvin, Jonny

2014-09-01

Accurate color control of LED lighting systems is a challenging task: noticeable chromaticity shifts are commonly observed in mixed-color and phosphor converted LEDs due to intensity dimming. Furthermore, the emitted color varies with the LED temperature. We present a novel color control method for tri-chromatic and tetra-chromatic LEDs, which enable to set and maintain the LED emission at a target color, or combination of correlated color temperature (CCT) and intensity. The LED color point is maintained over variations in the LED junctions' temperatures and intensity dimming levels. The method does not require color feedback sensors, so to minimize system complexity and cost, but relies on estimation of the LED junctions' temperatures from the junction voltages. If operated with tetra-chromatic LEDs, the method allows meeting an additional optimization criterion: for example, the maximization of a color rendering metric like the Color Rendering Index (CRI) or the Color Quality Scale (CQS), thus providing a high quality and clarity of colors on the surface illuminated by the LED. We demonstrate the control of a RGBW LED at target D65 white point with CIELAB color difference metric triangle;a,bE < 1 for simultaneous variations of flux from approximately 30 lm to 100 lm and LED heat sink temperature from 25°C to 58°C. In the same conditions, we demonstrate a CCT error <1%. Furthermore, the method allows varying the LED CCT from 5500K to 8000K while maintaining luminance within 1% of target. Further work is ongoing to evaluate the stability of the method over LED aging.

Dual-Color Bioluminescence Imaging for Simultaneous Monitoring of the Intestinal Persistence of Lactobacillus plantarum and Lactococcus lactis in Living Mice

PubMed Central

Poiret, Sabine; Dennin, Véronique; Boutillier, Denise; Lacorre, Delphine Armelle; Foligné, Benoit; Pot, Bruno

2015-01-01

Lactic acid bacteria are found in the gastrointestinal tract of mammals and have received tremendous attention due to their health-promoting properties. We report the development of two dual-color luciferase-producing Lactobacillus (Lb.) plantarum and Lactococcus (Lc.) lactis strains for noninvasive simultaneous tracking in the mouse gastrointestinal tract. We previously described the functional expression of the red luciferase mutant (CBRluc) from Pyrophorus plagiophthalamus in Lb. plantarum NCIMB8826 and Lc. lactis MG1363 (C. Daniel, S. Poiret, V. Dennin, D. Boutillier, and B. Pot, Appl Environ Microbiol 79:1086–1094, 2013, http://dx.doi.org/10.1128/AEM.03221-12). In this study, we determined that CBRluc is a better-performing luciferase for in vivo localization of both lactic acid bacteria after oral administration than the green click beetle luciferase mutant construct developed in this study. We further established the possibility to simultaneously detect red- and green-emitting lactic acid bacteria by dual-wavelength bioluminescence imaging in combination with spectral unmixing. The difference in spectra of light emission by the red and green click beetle luciferase mutants and dual bioluminescence detection allowed in vitro and in vivo quantification of the red and green emitted signals; thus, it allowed us to monitor the dynamics and fate of the two bacterial populations simultaneously. Persistence and viability of both strains simultaneously administered to mice in different ratios was studied in vivo in anesthetized mice and ex vivo in mouse feces. The application of dual-luciferase-labeled bacteria has considerable potential to simultaneously study the interactions and potential competitions of different targeted bacteria and their hosts. PMID:26025906

Constancy and diversity in the flavivirus fusion peptide.

PubMed

Seligman, Stephen J

2008-02-14

Flaviviruses include the mosquito-borne dengue, Japanese encephalitis, yellow fever and West Nile and the tick-borne encephalitis viruses. They are responsible for considerable world-wide morbidity and mortality. Viral entry is mediated by a conserved fusion peptide containing 16 amino acids located in domain II of the envelope protein E. Highly orchestrated conformational changes initiated by exposure to acidic pH accompany the fusion process and are important factors limiting amino acid changes in the fusion peptide that still permit fusion with host cell membranes in both arthropod and vertebrate hosts. The cell-fusing related agents, growing only in mosquitoes or insect cell lines, possess a different homologous peptide. Analysis of 46 named flaviviruses deposited in the Entrez Nucleotides database extended the constancy in the canonical fusion peptide sequences of mosquito-borne, tick-borne and viruses with no known vector to include more recently-sequenced viruses. The mosquito-borne signature amino acid, G104, was also found in flaviviruses with no known vector and with the cell-fusion related viruses. Despite the constancy in the canonical sequences in pathogenic flaviviruses, mutations were surprisingly frequent with a 27% prevalence of nonsynonymous mutations in yellow fever virus fusion peptide sequences, and 0 to 7.4% prevalence in the others. Six of seven yellow fever patients whose virus had fusion peptide mutations died. In the cell-fusing related agents, not enough sequences have been deposited to estimate reliably the prevalence of fusion peptide mutations. However, the canonical sequences homologous to the fusion peptide and the pattern of disulfide linkages in protein E differed significantly from the other flaviviruses. The constancy of the canonical fusion peptide sequences in the arthropod-borne flaviviruses contrasts with the high prevalence of mutations in most individual viruses. The discrepancy may be the result of a survival advantage accompanying sequence diversity (quasispecies) involving the fusion peptide. Limited clinical data with yellow fever virus suggest that the presence of fusion peptide mutants is not associated with a decreased case fatality rate. The cell-fusing related agents may have substantial differences from other flaviviruses in their mechanism of viral entry into the host cell.

Integration of color, orientation, and size functional domains in the ventral pathway

PubMed Central

Ghose, Geoffrey M.; Ts’o, Daniel Y.

2017-01-01

Abstract. Functional specialization within the extrastriate areas of the ventral pathway associated with visual form analysis is poorly understood. Studies comparing the functional selectivities of neurons within the early visual areas have found that there are more similar than different between the areas. We simultaneously imaged visually evoked activation over regions of V2 and V4 and parametrically varied three visual attributes for which selectivity exists in both areas: color, orientation, and size. We found that color selective regions were observed in both areas and were of similar size and spatial distribution. However, two major areal distinctions were observed: V4 contained a greater number and diversity of color-specific regions than V2 and exhibited a higher degree of overlap between domains for different functional attributes. In V2, size and color regions were largely segregated from orientation domains, whereas in V4 both color and size regions overlapped considerably with orientation regions. Our results suggest that higher-order composite selectivities in the extrastriate cortex may arise organically from the interactions afforded by an overlap of functional domains for lower order selectivities. PMID:28573155

Simultaneous RGB lasing from a single-chip polymer device.

PubMed

Yamashita, Kenichi; Takeuchi, Nobutaka; Oe, Kunishige; Yanagi, Hisao

2010-07-15

This Letter describes the fabrication and operation of a single-chip white-laser device. The laser device has a multilayered structure consisting of three laser layers. Each laser layer comprises polymer claddings and a waveguide core doped with organic dye. In each laser layer, grating corrugations were fabricated by UV-nanoimprint lithography that act as distributed-feedback cavity structures. Under optical pumping, lasing output with red, green, and blue colors was simultaneously obtained from the sample edge.

Simultaneous and quantitative monitoring of co-cultured Pseudomonas aeruginosa and Staphylococcus aureus with antibiotics on a diffusometric platform

NASA Astrophysics Data System (ADS)

Chung, Chih-Yao; Wang, Jhih-Cheng; Chuang, Han-Sheng

2017-04-01

Successful treatments against bacterial infections depend on antimicrobial susceptibility testing (AST). However, conventional AST requires more than 24 h to obtain an outcome, thereby contributing to high patient mortality. An antibiotic therapy based on experiences is therefore necessary for saving lives and escalating the emergence of multidrug-resistant pathogens. Accordingly, a fast and effective drug screen is necessary for the appropriate administration of antibiotics. The mixed pathogenic nature of infectious diseases emphasizes the need to develop an assay system for polymicrobial infections. On this basis, we present a novel technique for simultaneous and quantitative monitoring of co-cultured microorganisms by coupling optical diffusometry with bead-based immunoassays. This simple integration simultaneously achieves a rapid AST analysis for two pathogens. Triple color particles were simultaneously recorded and subsequently analyzed by functionalizing different fluorescent color particles with dissimilar pathogen-specific antibodies. Results suggested that the effect of the antibiotic, gentamicin, on co-cultured Pseudomonas aeruginosa and Staphylococcus aureus was effectively distinguished by the proposed technique. This study revealed a multiplexed and time-saving (within 2 h) platform with a small sample volume (~0.5 μL) and a low initial bacterial count (50 CFU per droplet, ~105 CFU/mL) for continuously monitoring the growth of co-cultured microorganisms. This technique provides insights into timely therapies against polymicrobial diseases in the near future.

Early steps of supported bilayer formation probed by single vesicle fluorescence assays.

PubMed Central

Johnson, Joseph M; Ha, Taekjip; Chu, Steve; Boxer, Steven G

2002-01-01

We have developed a single vesicle assay to study the mechanisms of supported bilayer formation. Fluorescently labeled, unilamellar vesicles (30-100 nm diameter) were first adsorbed to a quartz surface at low enough surface concentrations to visualize single vesicles. Fusion and rupture events during the bilayer formation, induced by the subsequent addition of unlabeled vesicles, were detected by measuring two-color fluorescence signals simultaneously. Lipid-conjugated dyes monitored the membrane fusion while encapsulated dyes reported on the vesicle rupture. Four dominant pathways were observed, each exhibiting characteristic two-color fluorescence signatures: 1) primary fusion, in which an unlabeled vesicle fuses with a labeled vesicle on the surface, is signified by the dequenching of the lipid-conjugated dyes followed by rupture and final merging into the bilayer; 2) simultaneous fusion and rupture, in which a labeled vesicle on the surface ruptures simultaneously upon fusion with an unlabeled vesicle; 3) no dequenching, in which loss of fluorescence signal from both dyes occur simultaneously with the final merger into the bilayer; and 4) isolated rupture (pre-ruptured vesicles), in which a labeled vesicle on the surface spontaneously undergoes content loss, a process that occurs with high efficiency in the presence of a high concentration of Texas Red-labeled lipids. Vesicles that have undergone content loss appear to be more fusogenic than intact vesicles. PMID:12496104

Slantingly cross loading sample system enables simultaneous performance of separation and mixture to detect molecular interactions on thin-layer chromatography.

PubMed

Shimizu-Yumoto, Hiroko; Hayashi, Nobuyuki; Ichimura, Kazuo; Nakayama, Masayoshi

2012-07-06

Anthocyanins are major flower pigments that can be affected by copigments, colorless compounds that can modify anthocyanin coloration to more intense and bluer. Thin-layer chromatography (TLC) is an available technique to separate and analyze anthocyanins and copigments. To easily and comprehensively detect copigments, we added function of mixture of compounds to TLC; by slantingly cross loading samples on TLC, compounds are symmetrically developed at various angle lines from the upper origin to individual R(f) values and cross each other in an orderly fashion, where mixture is simultaneously performed with separation. Occurrence of copigments can be detected as a coloration change on the developed line of anthocyanin. Pink sweet pea (Lathyrus odoratus L.) petals were analyzed by the cross-TLC and a more intense spot and a paler spot on the anthocyanin line were detected. As each spot overlapped with an ultraviolet absorbance line, each of these ultraviolet absorption compounds was purified and identified as kaempferol 3-rhamnoside and 2-cyanoethyl-isoxazolin-5-one, respectively. Whereas kaempferol 3-rhamnoside is a flavonoid and had a general copigment effect of more intense and bluer coloration change, 2-cyanoethyl-isoxazolin-5-one is a compound whose structure is outside of conventional categories of copigments and had a novel effect to change anthocyanin coloration paler while maintaining color tone. We determined that the search for copigments should be carried out without pre-existing prediction of structures and effects. We have shown that slantingly cross loading samples system on plate-type chromatography is an effective technique for such comprehensive analysis of molecular interaction. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Object properties and cognitive load in the formation of associative memory during precision lifting.

PubMed

Li, Yong; Randerath, Jennifer; Bauer, Hans; Marquardt, Christian; Goldenberg, Georg; Hermsdörfer, Joachim

2009-01-03

When we manipulate familiar objects in our daily life, our grip force anticipates the physical demands right from the moment of contact with the object, indicating the existence of a memory for relevant object properties. This study explores the formation and consolidation of the memory processes that associate either familiar (size) or arbitrary object features (color) with object weight. In the general task, participants repetitively lifted two differently weighted objects (580 and 280 g) in a pseudo-random order. Forty young healthy adults participated in this study and were randomly distributed into four groups: Color Cue Single task (CCS, blue and red, 9.8(3)cm(3)), Color Cue Dual task (CCD), No Cue (NC) and Size Cue (SC, 9.8(3) and 6(3)cm(3)) group. All groups performed a repetitive precision grasp-lift task and were retested with the same protocol after a 5-min pause. The CCD group was also required to simultaneously perform a memory task during each lift of differently weighted objects coded by color. The results show that groups lifting objects with arbitrary or familiar features successfully formed the association between object weight and manipulated object features and incorporated this into grip force programming, as observed in the different scaling of grip force and grip force rate for different object weights. An arbitrary feature, i.e., color, can be sufficiently associated with object weight, however with less strength than the familiar feature of size. The simultaneous memory task impaired anticipatory force scaling during repetitive object lifting but did not jeopardize the learning process and the consolidation of the associative memory.

The role of lightness, hue and saturation in feature-based visual attention.

PubMed

Stuart, Geoffrey W; Barsdell, Wendy N; Day, Ross H

2014-03-01

Visual attention is used to select part of the visual array for higher-level processing. Visual selection can be based on spatial location, but it has also been demonstrated that multiple locations can be selected simultaneously on the basis of a visual feature such as color. One task that has been used to demonstrate feature-based attention is the judgement of the symmetry of simple four-color displays. In a typical task, when symmetry is violated, four squares on either side of the display do not match. When four colors are involved, symmetry judgements are made more quickly than when only two of the four colors are involved. This indicates that symmetry judgements are made one color at a time. Previous studies have confounded lightness, hue, and saturation when defining the colors used in such displays. In three experiments, symmetry was defined by lightness alone, lightness plus hue, or by hue or saturation alone, with lightness levels randomised. The difference between judgements of two- and four-color asymmetry was maintained, showing that hue and saturation can provide the sole basis for feature-based attentional selection. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

VARiD: a variation detection framework for color-space and letter-space platforms.

PubMed

Dalca, Adrian V; Rumble, Stephen M; Levy, Samuel; Brudno, Michael

2010-06-15

High-throughput sequencing (HTS) technologies are transforming the study of genomic variation. The various HTS technologies have different sequencing biases and error rates, and while most HTS technologies sequence the residues of the genome directly, generating base calls for each position, the Applied Biosystem's SOLiD platform generates dibase-coded (color space) sequences. While combining data from the various platforms should increase the accuracy of variation detection, to date there are only a few tools that can identify variants from color space data, and none that can analyze color space and regular (letter space) data together. We present VARiD--a probabilistic method for variation detection from both letter- and color-space reads simultaneously. VARiD is based on a hidden Markov model and uses the forward-backward algorithm to accurately identify heterozygous, homozygous and tri-allelic SNPs, as well as micro-indels. Our analysis shows that VARiD performs better than the AB SOLiD toolset at detecting variants from color-space data alone, and improves the calls dramatically when letter- and color-space reads are combined. The toolset is freely available at http://compbio.cs.utoronto.ca/varid.

Data Images and Other Graphical Displays for Directional Data

NASA Technical Reports Server (NTRS)

Morphet, Bill; Symanzik, Juergen

2005-01-01

Vectors, axes, and periodic phenomena have direction. Directional variation can be expressed as points on a unit circle and is the subject of circular statistics, a relatively new application of statistics. An overview of existing methods for the display of directional data is given. The data image for linear variables is reviewed, then extended to directional variables by displaying direction using a color scale composed of a sequence of four or more color gradients with continuity between sequences and ordered intuitively in a color wheel such that the color of the 0deg angle is the same as the color of the 360deg angle. Cross over, which arose in automating the summarization of historical wind data, and color discontinuity resulting from the use a single color gradient in computational fluid dynamics visualization are eliminated. The new method provides for simultaneous resolution of detail on a small scale and overall structure on a large scale. Example circular data images are given of a global view of average wind direction of El Nino periods, computed rocket motor internal combustion flow, a global view of direction of the horizontal component of earth's main magnetic field on 9/15/2004, and Space Shuttle solid rocket motor nozzle vectoring.

Contrast enhancement of bite mark images using the grayscale mixer in ACR in Photoshop®.

PubMed

Evans, Sam; Noorbhai, Suzanne; Lawson, Zoe; Stacey-Jones, Seren; Carabott, Romina

2013-05-01

Enhanced images may improve bite mark edge definition, assisting forensic analysis. Current contrast enhancement involves color extraction, viewing layered images by channel. A novel technique, producing a single enhanced image using the grayscale mix panel within Adobe Camera Raw®, has been developed and assessed here, allowing adjustments of multiple color channels simultaneously. Stage 1 measured RGB values in 72 versions of a color chart image; eight sliders in Photoshop® were adjusted at 25% intervals, all corresponding colors affected. Stage 2 used a bite mark image, and found only red, orange, and yellow sliders had discernable effects. Stage 3 assessed modality preference between color, grayscale, and enhanced images; on average, the 22 survey participants chose the enhanced image as better defined for nine out of 10 bite marks. The study has shown potential benefits for this new technique. However, further research is needed before use in the analysis of bite marks. © 2013 American Academy of Forensic Sciences.

Single master regulatory gene coordinates the evolution and development of butterfly color and iridescence

PubMed Central

Zhang, Linlin

2017-01-01

The optix gene has been implicated in butterfly wing pattern adaptation by genetic association, mapping, and expression studies. The actual developmental function of this gene has remained unclear, however. Here we used CRISPR/Cas9 genome editing to show that optix plays a fundamental role in nymphalid butterfly wing pattern development, where it is required for determination of all chromatic coloration. optix knockouts in four species show complete replacement of color pigments with melanins, with corresponding changes in pigment-related gene expression, resulting in black and gray butterflies. We also show that optix simultaneously acts as a switch gene for blue structural iridescence in some butterflies, demonstrating simple regulatory coordination of structural and pigmentary coloration. Remarkably, these optix knockouts phenocopy the recurring “black and blue” wing pattern archetype that has arisen on many independent occasions in butterflies. Here we demonstrate a simple genetic basis for structural coloration, and show that optix plays a deeply conserved role in butterfly wing pattern development. PMID:28923944

Single master regulatory gene coordinates the evolution and development of butterfly color and iridescence.

PubMed

Zhang, Linlin; Mazo-Vargas, Anyi; Reed, Robert D

2017-10-03

The optix gene has been implicated in butterfly wing pattern adaptation by genetic association, mapping, and expression studies. The actual developmental function of this gene has remained unclear, however. Here we used CRISPR/Cas9 genome editing to show that optix plays a fundamental role in nymphalid butterfly wing pattern development, where it is required for determination of all chromatic coloration. optix knockouts in four species show complete replacement of color pigments with melanins, with corresponding changes in pigment-related gene expression, resulting in black and gray butterflies. We also show that optix simultaneously acts as a switch gene for blue structural iridescence in some butterflies, demonstrating simple regulatory coordination of structural and pigmentary coloration. Remarkably, these optix knockouts phenocopy the recurring "black and blue" wing pattern archetype that has arisen on many independent occasions in butterflies. Here we demonstrate a simple genetic basis for structural coloration, and show that optix plays a deeply conserved role in butterfly wing pattern development.

Color-Space-Based Visual-MIMO for V2X Communication †

PubMed Central

Kim, Jai-Eun; Kim, Ji-Won; Park, Youngil; Kim, Ki-Doo

2016-01-01

In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance. PMID:27120603

Color-Space-Based Visual-MIMO for V2X Communication.

PubMed

Kim, Jai-Eun; Kim, Ji-Won; Park, Youngil; Kim, Ki-Doo

2016-04-23

In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance.

Discrimination Learning in Children

ERIC Educational Resources Information Center

Ochocki, Thomas E.; And Others

1975-01-01

Examined the learning performance of 192 fourth-, fifth-, and sixth-grade children on either a two or four choice simultaneous color discrimination task. Compared the use of verbal reinforcement and/or punishment, under conditions of either complete or incomplete instructions. (Author/SDH)

MASSCLEANage—Stellar Cluster Ages from Integrated Colors

NASA Astrophysics Data System (ADS)

Popescu, Bogdan; Hanson, M. M.

2010-11-01

We present the recently updated and expanded MASSCLEANcolors, a database of 70 million Monte Carlo models selected to match the properties (metallicity, ages, and masses) of stellar clusters found in the Large Magellanic Cloud (LMC). This database shows the rather extreme and non-Gaussian distribution of integrated colors and magnitudes expected with different cluster age and mass and the enormous age degeneracy of integrated colors when mass is unknown. This degeneracy could lead to catastrophic failures in estimating age with standard simple stellar population models, particularly if most of the clusters are of intermediate or low mass, like in the LMC. Utilizing the MASSCLEANcolors database, we have developed MASSCLEANage, a statistical inference package which assigns the most likely age and mass (solved simultaneously) to a cluster based only on its integrated broadband photometric properties. Finally, we use MASSCLEANage to derive the age and mass of LMC clusters based on integrated photometry alone. First, we compare our cluster ages against those obtained for the same seven clusters using more accurate integrated spectroscopy. We find improved agreement with the integrated spectroscopy ages over the original photometric ages. A close examination of our results demonstrates the necessity of solving simultaneously for mass and age to reduce degeneracies in the cluster ages derived via integrated colors. We then selected an additional subset of 30 photometric clusters with previously well-constrained ages and independently derive their age using the MASSCLEANage with the same photometry with very good agreement. The MASSCLEANage program is freely available under GNU General Public License.

Hyperspectral imaging of cuttlefish camouflage indicates good color match in the eyes of fish predators.

PubMed

Chiao, Chuan-Chin; Wickiser, J Kenneth; Allen, Justine J; Genter, Brock; Hanlon, Roger T

2011-05-31

Camouflage is a widespread phenomenon throughout nature and an important antipredator tactic in natural selection. Many visual predators have keen color perception, and thus camouflage patterns should provide some degree of color matching in addition to other visual factors such as pattern, contrast, and texture. Quantifying camouflage effectiveness in the eyes of the predator is a challenge from the perspectives of both biology and optical imaging technology. Here we take advantage of hyperspectral imaging (HSI), which records full-spectrum light data, to simultaneously visualize color match and pattern match in the spectral and the spatial domains, respectively. Cuttlefish can dynamically camouflage themselves on any natural substrate and, despite their colorblindness, produce body patterns that appear to have high-fidelity color matches to the substrate when viewed directly by humans or with RGB images. Live camouflaged cuttlefish on natural backgrounds were imaged using HSI, and subsequent spectral analysis revealed that most reflectance spectra of individual cuttlefish and substrates were similar, rendering the color match possible. Modeling color vision of potential di- and trichromatic fish predators of cuttlefish corroborated the spectral match analysis and demonstrated that camouflaged cuttlefish show good color match as well as pattern match in the eyes of fish predators. These findings (i) indicate the strong potential of HSI technology to enhance studies of biological coloration and (ii) provide supporting evidence that cuttlefish can produce color-coordinated camouflage on natural substrates despite lacking color vision.

How do we select multiple features? Transient costs for selecting two colors rather than one, persistent costs for color-location conjunctions.

PubMed

Lo, Shih-Yu; Holcombe, Alex O

2014-02-01

In a previous study Lo, Howard, & Holcombe (Vision Research 63:20-33, 2012), selecting two colors did not induce a performance cost, relative to selecting one color. For example, requiring possible report of both a green and a red target did not yield a worse performance than when both targets were green. Yet a cost of selecting multiple colors was observed when selection needed be contingent on both color and location. When selecting a red target to the left and a green target to the right, superimposing a green distractor to the left and a red distractor to the right impeded performance. Possibly, participants cannot confine attention to a color at a particular location. As a result, distractors that share the target colors disrupt attentional selection of the targets. The attempt to select the targets must then be repeated, which increases the likelihood that the trial terminates when selection is not effective, even for long trials. Consistent with this, here we find a persistent cost of selecting two colors when the conjunction of color and location is needed, but the cost is confined to short exposure durations when the observer just has to monitor red and green stimuli without the need to use the location information. These results suggest that selecting two colors is time-consuming but effective, whereas selection of simultaneous conjunctions is never entirely successful.

Cosmic ray exposure ages of iron meteorites, complex irradiation and the constancy of cosmic ray flux in the past

NASA Technical Reports Server (NTRS)

Marti, K.; Lavielle, B.; Regnier, S.

1984-01-01

While previous calculations of potassium ages assumed a constant cosmic ray flux and a single stage (no change in size) exposure of iron meteorites, present calculations relaxed these constancy assumptions and the results reveal multistage irradiations for some 25% of the meteorites studied, implying multiple breakup in space. The distribution of exposure ages suggests several major collisions (based on chemical composition and structure), although the calibration of age scales is not yet complete. It is concluded that shielding-corrected (corrections which depend on size and position of sample) production rates are consistent for the age bracket of 300 to 900 years. These production rates differ in a systematic way from those calculated for present day fluxes of cosmic rays (such as obtained for the last few million years).

Activity and Diversity of Methanotrophic Bacteria at Methane Seeps in Eastern Lake Constance Sediments ▿

PubMed Central

Deutzmann, Jörg S.; Wörner, Susanne; Schink, Bernhard

2011-01-01

The activity and community structure of aerobic methanotrophic communities were investigated at methane seeps (pockmarks) in the littoral and profundal zones of an oligotrophic freshwater lake (Lake Constance, Germany). Measurements of potential methane oxidation rates showed that sediments inside littoral pockmarks are hot spots of methane oxidation. Potential methane oxidation rates at littoral pockmark sites exceeded the rates of the surrounding sediment by 2 orders of magnitude. Terminal restriction fragment length polymorphism (T-RFLP) analysis of the pmoA gene revealed major differences in the methanotrophic community composition between littoral pockmarks and the surrounding sediments. Clone library analysis confirmed that one distinct Methylobacter-related group dominates the community at littoral pockmarks. In profundal sediments, the differences between pockmarks and surrounding sediments were found to be less pronounced. PMID:21335392

Relating streamflow characteristics to specialized insectivores in the Tennessee River Valley: a regional approach

USGS Publications Warehouse

Knight, Rodney R.; Gregory, M. Brian; Wales, Amy K.

2008-01-01

Analysis of hydrologic time series and fish community data across the Tennessee River Valley identified three hydrologic metrics essential to habitat suitability and food availability for insectivorous fish communities in streams of the Tennessee River Valley: constancy (flow stability or temporal invariance), frequency of moderate flooding (frequency of habitat disturbance), and rate of streamflow recession. Initial datasets included 1100 fish community sites and 300 streamgages. Reduction of these datasets to sites with coexisting data yielded 33 sites with streamflow and fish community data for analysis. Identification of critical hydrologic metrics was completed using a multivariate correlation procedure that maximizes the rank correlation between the hydrologic metrics and fish community resemblance matrices. Quantile regression was used to define thresholds of potential ranges of insectivore scores for given values of the hydrologic metrics. Increased values of constancy and insectivore scores were positively correlated. Constancy of streamflow maintains wetted perimeter, which is important for providing habitat for fish spawning and increased surface area for invertebrate colonization and reproduction. Site scores for insectivorous fish increased as the frequency of moderate flooding (3 times the median annual streamflow) decreased, suggesting that insectivorous fish communities respond positively to less frequent disturbance and a more stable habitat. Increased streamflow recession rates were associated with decreased insectivore scores. Increased streamflow recession can strand fish in pools and other areas that are disconnected from flowing water and remove invertebrates as food sources that were suspended during high-streamflow events.

Optofluidic wavelength division multiplexing for single-virus detection

PubMed Central

Ozcelik, Damla; Parks, Joshua W.; Wall, Thomas A.; Stott, Matthew A.; Cai, Hong; Parks, Joseph W.; Hawkins, Aaron R.; Schmidt, Holger

2015-01-01

Optical waveguides simultaneously transport light at different colors, forming the basis of fiber-optic telecommunication networks that shuttle data in dozens of spectrally separated channels. Here, we reimagine this wavelength division multiplexing (WDM) paradigm in a novel context––the differentiated detection and identification of single influenza viruses on a chip. We use a single multimode interference (MMI) waveguide to create wavelength-dependent spot patterns across the entire visible spectrum and enable multiplexed single biomolecule detection on an optofluidic chip. Each target is identified by its time-dependent fluorescence signal without the need for spectral demultiplexing upon detection. We demonstrate detection of individual fluorescently labeled virus particles of three influenza A subtypes in two implementations: labeling of each virus using three different colors and two-color combinatorial labeling. By extending combinatorial multiplexing to three or more colors, MMI-based WDM provides the multiplexing power required for differentiated clinical tests and the growing field of personalized medicine. PMID:26438840

Prediction of textural attributes using color values of banana (Musa sapientum) during ripening.

PubMed

Jaiswal, Pranita; Jha, Shyam Narayan; Kaur, Poonam Preet; Bhardwaj, Rishi; Singh, Ashish Kumar; Wadhawan, Vishakha

2014-06-01

Banana is an important sub-tropical fruit in international trade. It undergoes significant textural and color transformations during ripening process, which in turn influence the eating quality of the fruit. In present study, color ('L', 'a' and 'b' value) and textural attributes of bananas (peel, fruit and pulp firmness; pulp toughness; stickiness) were studied simultaneously using Hunter Color Lab and Texture Analyser, respectively, during ripening period of 10 days at ambient atmosphere. There was significant effect of ripening period on all the considered textural characteristics and color properties of bananas except color value 'b'. In general, textural descriptors (peel, fruit and pulp firmness; and pulp toughness) decreased during ripening except stickiness, while color values viz 'a' and 'b' increased with ripening barring 'L' value. Among various textural attributes, peel toughness and pulp firmness showed highest correlation (r) with 'a' value of banana peel. In order to predict textural properties using color values of banana, five types of equations (linear/polynomial/exponential/logarithmic/power) were fitted. Among them, polynomial equation was found to be the best fit (highest coefficient of determination, R(2)) for prediction of texture using color properties for bananas. The pulp firmness, peel toughness and pulp toughness showed R(2) above 0.84 with indicating its potentiality of the fitted equations for prediction of textural profile of bananas non-destructively using 'a' value.

Color silver halide hologram production and mastering

NASA Astrophysics Data System (ADS)

Bjelkhagen, Hans I.; Huang, Qiang

1997-04-01

Color reflection holograms recorded with the Denisyuk geometry have been demonstrated by the recently formed HOLOS Corporation in New Hampshire. The Slavich red-green-blue (RGB) sensitized ultra-high resolution silver halide emulsion was used for the hologram recording. The employed laser wavelengths were 647 nm, 532 nm, and 476 nm, generated by an argon ion, a frequency doubled Nd:YAG, and a krypton ion laser, respectively. A beam combination mechanism with dichroic filters enabled a simultaneous RGB exposure, which made the color balance and overall exposure energy easy to control as well as simplifying the recording procedure. HOLOS has been producing limited edition color holograms in various sizes from 4' X 5' to 12' X 16'. A 30 foot long optical table and high power lasers will enable HOLOS to record color holograms up to the size of one meter square in the near future. Various approaches have been investigated in generating color hologram masters which have sufficiently high diffraction efficiency to contact copy the color images onto photopolymer materials. A specially designed test object including the 1931 CIE chromaticity diagram, a rainbow ribbon cable, pure yellow dots, and a cloisonne elephant was used for color recording experiments. In addition, the Macbeth Color Checker chart was used. Both colorimetric evaluation and scattering noise measurements were performed using the PR-650 Photo Research SpectraScan SpectraCalorimeter.

Spatial patterns of correlated scale size and scale color in relation to color pattern elements in butterfly wings.

PubMed

Iwata, Masaki; Otaki, Joji M

2016-02-01

Complex butterfly wing color patterns are coordinated throughout a wing by unknown mechanisms that provide undifferentiated immature scale cells with positional information for scale color. Because there is a reasonable level of correspondence between the color pattern element and scale size at least in Junonia orithya and Junonia oenone, a single morphogenic signal may contain positional information for both color and size. However, this color-size relationship has not been demonstrated in other species of the family Nymphalidae. Here, we investigated the distribution patterns of scale size in relation to color pattern elements on the hindwings of the peacock pansy butterfly Junonia almana, together with other nymphalid butterflies, Vanessa indica and Danaus chrysippus. In these species, we observed a general decrease in scale size from the basal to the distal areas, although the size gradient was small in D. chrysippus. Scales of dark color in color pattern elements, including eyespot black rings, parafocal elements, and submarginal bands, were larger than those of their surroundings. Within an eyespot, the largest scales were found at the focal white area, although there were exceptional cases. Similarly, ectopic eyespots that were induced by physical damage on the J. almana background area had larger scales than in the surrounding area. These results are consistent with the previous finding that scale color and size coordinate to form color pattern elements. We propose a ploidy hypothesis to explain the color-size relationship in which the putative morphogenic signal induces the polyploidization (genome amplification) of immature scale cells and that the degrees of ploidy (gene dosage) determine scale color and scale size simultaneously in butterfly wings. Copyright © 2015 Elsevier Ltd. All rights reserved.

Color Perception in Pediatric Patient Room Design: American versus Korean Pediatric Patients.

PubMed

Phillip Park, Jin Gyu; Park, Changbae

2013-01-01

This study simultaneously addresses the issues of the scarcity of information about pediatric patient color preferences, conflicting findings about the impact of culture on color preferences, and limitations of previous research instruments. Effects of culture and gender on color preferences were investigated using American and Korean pediatric patients. Much of the existing research in environmental design has focused on environments for healthy children and adults, but those findings cannot be confidently applied to environments for pediatric patients. In previous studies, the impact of culture on color preferences has been suggested, though the effects appear to vary. Moreover, the results of previous studies were typically based on perceptions of small color chips, which are different from seeing a color on wall surfaces. Previous studies also failed to control for confounding variables such as color attributes and light sources. Instead of using color chips, this study used physical model simulation to investigate environmental color preferences in real contexts. Cultural difference was found in white. Other than white, no significant cultural difference was found. Gender differences were found across both of the groups. Korean pediatric patients showed significantly higher preference scores for white than Americans did. Other than white, both groups reported blue and green as their most preferred colors; white was the least preferred. Both groups reported similar gender effects. Overall, male patients reported significantly lower preference scores for red and purple than female patients did. These results can help healthcare providers and professionals better understand appropriate colors for pediatric populations. Evidence-based design, healing environment, patients, pediatric, satisfaction.

Simultaneous Luminescence Pressure and Temperature Mapping

NASA Technical Reports Server (NTRS)

Buck, Gregory M. (Inventor)

1998-01-01

A simultaneous luminescence pressure and temperature mapping system is developed including improved dye application techniques for surface temperature and pressure measurements from 5 torr to 1000 torr with possible upgrade to from 0.5 torr to several atmospheres with improved camera resolution. Adsorbed perylene dye on slip-cast silica is pressure (oxygen) sensitive and reusable to relatively high temperatures (-150 C). Adsorbed luminescence has an approximately linear color shift with temperature, which can be used for independent temperature mapping and brightness pressure calibration with temperature.

Simultaneous Luminescence Pressure and Temperature Mapping System

NASA Technical Reports Server (NTRS)

Buck, Gregory M. (Inventor)

1995-01-01

A simultaneous luminescence pressure and temperature mapping system is developed including improved dye application techniques for surface temperature and pressure measurements from 5 torr to 1000 torr with possible upgrade to from 0.5 torr to several atmospheres with improved camera resolution. Adsorbed perylene dye on slip-cast silica is pressure (oxygen) sensitive and reusable to relatively high temperatures (approximately 150 C). Adsorbed luminescence has an approximately linear color shift with temperature, which can be used for independent temperature mapping and brightness pressure calibration with temperature.

Congressional Tribute to Constance Baker Motley Act of 2013

THOMAS, 113th Congress

Sen. Blumenthal, Richard [D-CT

2013-06-12

Senate - 06/12/2013 Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

An Acid Hydrocarbon: A Chemical Paradox

ERIC Educational Resources Information Center

Burke, Jeffrey T.

2004-01-01

The chemical paradox of cyclopentadiene, a hydrocarbon, producing bubbles like a Bronsted acid is observed. The explanation that it is the comparative thermodynamic constancy of the fragrant cyclopentadienyl anion, which produces the powerful effect, resolves the paradox.

Are There Really Animals Like That? No Cell Division.

ERIC Educational Resources Information Center

Blackwelder, R. E.; Garoian, G. S.

1984-01-01

Provides examples of animals in which growth occurs without cell division. Indicates that this phenomenon (called cell constancy or eutely) is an oddity of development that has arisen independently in several animal groups. (JN)

Characteristic vector analysis of inflection ratio spectra: New technique for analysis of ocean color data

NASA Technical Reports Server (NTRS)

Grew, G. W.

1985-01-01

Characteristic vector analysis applied to inflection ratio spectra is a new approach to analyzing spectral data. The technique applied to remote data collected with the multichannel ocean color sensor (MOCS), a passive sensor, simultaneously maps the distribution of two different phytopigments, chlorophyll alpha and phycoerythrin, the ocean. The data set presented is from a series of warm core ring missions conducted during 1982. The data compare favorably with a theoretical model and with data collected on the same mission by an active sensor, the airborne oceanographic lidar (AOL).

Coordinated X-ray and optical observations of Scorpius X-1

NASA Technical Reports Server (NTRS)

Augusteijn, T.; Karatasos, K.; Papadakis, M.; Paterakis, G.; Kikuchi, S.; Brosch, N.; Leibowitz, E.; Hertz, P.; Mitsuda, K.; Dotani, T.

1992-01-01

We present the results of coordinated, partly simultaneous, optical and X-ray (Ginga) observations of the low-mass X-ray binary Sco X-1. We find that the division between the optically bright and faint state, at a blue magnitude B = 12.8, corresponds to the change from the normal to the flaring branch in the X-ray color-color diagram as proposed by Priedhorsky et al. (1986). From archival Walraven data we find that in both optical states the orbital light curve is approximately sinusoidal, and have a similar amplitudes.

Theory of dispersive microlenses

NASA Technical Reports Server (NTRS)

Herman, B.; Gal, George

1993-01-01

A dispersive microlens is a miniature optical element which simultaneously focuses and disperses light. Arrays of dispersive mircolenses have potential applications in multicolor focal planes. They have a 100 percent optical fill factor and can focus light down to detectors of diffraction spot size, freeing up areas on the focal plane for on-chip analog signal processing. Use of dispersive microlenses allows inband color separation within a pixel and perfect scene registration. A dual-color separation has the potential for temperature discrimination. We discuss the design of dispersive microlenses and present sample results for efficient designs.

Single-Shot Optical Sectioning Using Two-Color Probes in HiLo Fluorescence Microscopy

PubMed Central

Muro, Eleonora; Vermeulen, Pierre; Ioannou, Andriani; Skourides, Paris; Dubertret, Benoit; Fragola, Alexandra; Loriette, Vincent

2011-01-01

We describe a wide-field fluorescence microscope setup which combines HiLo microscopy technique with the use of a two-color fluorescent probe. It allows one-shot fluorescence optical sectioning of thick biological moving sample which is illuminated simultaneously with a flat and a structured pattern at two different wavelengths. Both homogenous and structured fluorescence images are spectrally separated at detection and combined similarly with the HiLo microscopy technique. We present optically sectioned full-field images of Xenopus laevis embryos acquired at 25 images/s frame rate. PMID:21641327

Multilayer coatings on glass for painting protection and optimized color rendering

NASA Astrophysics Data System (ADS)

Piegari, Angela; Polato, Pietro

2002-06-01

Optical coatings offer a solution to the problem of damage to paintings, caused by ultraviolet and infrared radiation, by cutting radiation wavelengths outside the visible range. Simultaneously, these coatings can enhance an observer's viewing of the paintings by reducing the reflections from ordinary glass panes. All these functions should be performed by the same coating. The design of such a coating, as well as the evaluation of existing products, requires the definition of an appropriate merit function in which coating absorption, high transparency, and color rendering are combined.

Astronaut David Scott watching hammer and feather fall to lunar surface

NASA Technical Reports Server (NTRS)

1971-01-01

Astronaut David R. Scott, Apollo 15 commander, watches a geological hammer and a feather hit the lunar surface simultaneously in a test of Galileo's law of motion concerning falling bodies, as seen in this color reproduction taken from a transmission made by the RCA color television camera mounted on the Lunar Roving Vehicle. Scott released the hammer from his right hand and the feather from his left at the same instant. This experiment occured toward the end of the third and final lunar surface extravehicular activity.

Carolinas Communication Annual, 1999.

ERIC Educational Resources Information Center

McLennan, David B.

1999-01-01

This 1999 issue of the "Carolinas Communication Annual" contains the following articles: "The Unmade Analogy: Alcohol and Abortion" (Richard W. Leeman); "Say, You Want a Revolution" (Roy Schwartzman and Constance Y. Green); "Exploring the Relationship between Perceived Narrativity and Persuasiveness"…

Limit on the present temporal variation of the fine structure constant.

PubMed

Peik, E; Lipphardt, B; Schnatz, H; Schneider, T; Tamm, Chr; Karshenboim, S G

2004-10-22

The comparison of different atomic transition frequencies over time can be used to determine the present value of the temporal derivative of the fine structure constant alpha in a model-independent way without assumptions on constancy or variability of other parameters, allowing tests of the consequences of unification theories. We have measured an optical transition frequency at 688 THz in 171Yb+ with a cesium atomic clock at 2 times separated by 2.8 yr and find a value for the fractional variation of the frequency ratio f(Yb)/f(Cs) of (-1.2+/-4.4)x10(-15) yr(-1), consistent with zero. Combined with recently published values for the constancy of other transition frequencies this measurement sets an upper limit on the present variability of alpha at the level of 2.0x10(-15) yr(-1) (1sigma), corresponding so far to the most stringent limit from laboratory experiments.

On analyzing colour constancy approach for improving SURF detector performance

NASA Astrophysics Data System (ADS)

Zulkiey, Mohd Asyraf; Zaki, Wan Mimi Diyana Wan; Hussain, Aini; Mustafa, Mohd. Marzuki

2012-04-01

Robust key point detector plays a crucial role in obtaining a good tracking feature. The main challenge in outdoor tracking is the illumination change due to various reasons such as weather fluctuation and occlusion. This paper approaches the illumination change problem by transforming the input image through colour constancy algorithm before applying the SURF detector. Masked grey world approach is chosen because of its ability to perform well under local as well as global illumination change. Every image is transformed to imitate the canonical illuminant and Gaussian distribution is used to model the global change. The simulation results show that the average number of detected key points have increased by 69.92%. Moreover, the average of improved performance cases far out weight the degradation case where the former is improved by 215.23%. The approach is suitable for tracking implementation where sudden illumination occurs frequently and robust key point detection is needed.

Simple single-emitting layer hybrid white organic light emitting with high color stability

NASA Astrophysics Data System (ADS)

Nguyen, C.; Lu, Z. H.

2017-10-01

Simultaneously achieving a high efficiency and color quality at luminance levels required for solid-state lighting has been difficult for white organic light emitting diodes (OLEDs). Single-emitting layer (SEL) white OLEDs, in particular, exhibit a significant tradeoff between efficiency and color stability. Furthermore, despite the simplicity of SEL white OLEDs being its main advantage, the reported device structures are often complicated by the use of multiple blocking layers. In this paper, we report a highly simplified three-layered white OLED that achieves a low turn-on voltage of 2.7 V, an external quantum efficiency of 18.9% and power efficiency of 30 lm/W at 1000 cd/cm2. This simple white OLED also shows good color quality with a color rendering index of 75, CIE coordinates (0.42, 0.46), and little color shifting at high luminance. The device consists of a SEL sandwiched between a hole transport layer and an electron transport layer. The SEL comprises a thermally activated delayer fluorescent molecule having dual functions as a blue emitter and as a host for other lower energy emitters. The improved color stability and efficiency in such a simple device structure is explained as due to the elimination of significant energy barriers at various organic-organic interfaces in the traditional devices having multiple blocking layers.

Photoresponsive Smart Coloration Electrochromic Supercapacitor.

PubMed

Yun, Tae Gwang; Kim, Donghyuk; Kim, Yong Ho; Park, Minkyu; Hyun, Seungmin; Han, Seung Min

2017-08-01

Electrochromic devices have been widely adopted in energy saving applications by taking advantage of the electrode coloration, but it is critical to develop a new electrochromic device that can undergo smart coloration and can have a wide spectrum in transmittance in response to input light intensity while also functioning as a rechargeable energy storage system. In this study, a photoresponsive electrochromic supercapacitor based on cellulose-nanofiber/Ag-nanowire/reduced-graphene-oxide/WO 3 -composite electrode that is capable of undergoing "smart" reversible coloration while simultaneously functioning as a reliable energy-storage device is developed. The fabricated device exhibits a high coloration efficiency of 64.8 cm 2 C -1 and electrochemical performance with specific capacitance of 406.0 F g -1 , energy/power densities of 40.6-47.8 Wh kg -1 and 6.8-16.9 kW kg -1 . The electrochromic supercapacitor exhibits excellent cycle reliability, where 75.0% and 94.1% of its coloration efficiency and electrochemical performance is retained, respectively, beyond 10 000 charge-discharge cycles. Cyclic fatigue tests show that the developed device is mechanically durable and suitable for wearable electronics applications. The smart electrochromic supercapacitor system is then integrated with a solar sensor to enable photoresponsive coloration where the transmittance changes in response to varying light intensity. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metacontrast masking is processed before grapheme-color synesthesia.

PubMed

Bacon, Michael Patrick; Bridgeman, Bruce; Ramachandran, Vilayanur S

2013-01-01

We investigated the physiological mechanism of grapheme-color synesthesia using metacontrast masking. A metacontrast target is rendered invisible by a mask that is delayed by about 60 ms; the target and mask do not overlap in space or time. Little masking occurs, however, if the target and mask are simultaneous. This effect must be cortical, because it can be obtained dichoptically. To compare the data for synesthetes and controls, we developed a metacontrast design in which nonsynesthete controls showed weaker dichromatic masking (i.e., the target and mask were in different colors) than monochromatic masking. We accomplished this with an equiluminant target, mask, and background for each observer. If synesthetic color affected metacontrast, synesthetes should show monochromatic masking more similar to the weak dichromatic masking among controls, because synesthetes could add their synesthetic color to the monochromatic condition. The target-mask pairs used for each synesthete were graphemes that elicited strong synesthetic colors. We found stronger monochromatic than dichromatic U-shaped metacontrast for both synesthetes and controls, with optimal masking at an asynchrony of 66 ms. The difference in performance between the monochromatic and dichromatic conditions in the synesthetes indicates that synesthesia occurs at a later processing stage than does metacontrast masking.

New feature of the neutron color image intensifier

NASA Astrophysics Data System (ADS)

Nittoh, Koichi; Konagai, Chikara; Noji, Takashi; Miyabe, Keisuke

2009-06-01

We developed prototype neutron color image intensifiers with high-sensitivity, wide dynamic range and long-life characteristics. In the prototype intensifier (Gd-Type 1), a terbium-activated Gd 2O 2S is used as the input-screen phosphor. In the upgraded model (Gd-Type 2), Gd 2O 3 and CsI:Na are vacuum deposited to form the phosphor layer, which improved the sensitivity and the spatial uniformity. A europium-activated Y 2O 2S multi-color scintillator, emitting red, green and blue photons with different intensities, is utilized as the output screen of the intensifier. By combining this image intensifier with a suitably tuned high-sensitive color CCD camera, higher sensitivity and wider dynamic range could be simultaneously attained than that of the conventional P20-phosphor-type image intensifier. The results of experiments at the JRR-3M neutron radiography irradiation port (flux: 1.5×10 8 n/cm 2/s) showed that these neutron color image intensifiers can clearly image dynamic phenomena with a 30 frame/s video picture. It is expected that the color image intensifier will be used as a new two-dimensional neutron sensor in new application fields.

Photonic Crystal Structures with Tunable Structure Color as Colorimetric Sensors

PubMed Central

Wang, Hui; Zhang, Ke-Qin

2013-01-01

Colorimetric sensing, which transduces environmental changes into visible color changes, provides a simple yet powerful detection mechanism that is well-suited to the development of low-cost and low-power sensors. A new approach in colorimetric sensing exploits the structural color of photonic crystals (PCs) to create environmentally-influenced color-changeable materials. PCs are composed of periodic dielectrics or metallo-dielectric nanostructures that affect the propagation of electromagnetic waves (EM) by defining the allowed and forbidden photonic bands. Simultaneously, an amazing variety of naturally occurring biological systems exhibit iridescent color due to the presence of PC structures throughout multi-dimensional space. In particular, some kinds of the structural colors in living organisms can be reversibly changed in reaction to external stimuli. Based on the lessons learned from natural photonic structures, some specific examples of PCs-based colorimetric sensors are presented in detail to demonstrate their unprecedented potential in practical applications, such as the detections of temperature, pH, ionic species, solvents, vapor, humidity, pressure and biomolecules. The combination of the nanofabrication technique, useful design methodologies inspired by biological systems and colorimetric sensing will lead to substantial developments in low-cost, miniaturized and widely deployable optical sensors. PMID:23539027

The association of color memory and the enumeration of multiple spatially overlapping sets.

PubMed

Poltoratski, Sonia; Xu, Yaoda

2013-07-09

Using dot displays, Halberda, Sires, and Feigenson (2006) showed that observers could simultaneously encode the numerosity of two spatially overlapping sets and the superset of all items at a glance. With the brief display and the masking used in Halberda et al., the task required observers to encode the colors of each set in order to select and enumerate all the dots in that set. As such, the observed capacity limit for set enumeration could reflect a limit in visual short-term memory (VSTM) capacity for the set color rather than a limit in set enumeration per se. Here, we largely replicated Halberda et al. and found successful enumeration of approximately two sets (the superset was not probed). We also found that only about two and a half colors could be remembered from the colored dot displays whether or not the enumeration task was performed concurrently with the color VSTM task. Because observers must remember the color of a set prior to enumerating it, the under three-item VSTM capacity for color necessarily dictates that set enumeration capacity in this paradigm could not exceed two sets. Thus, the ability to enumerate multiple spatially overlapping sets is likely limited by VSTM capacity to retain the discriminating feature of these sets. This relationship suggests that the capacity for set enumeration cannot be considered independently from the capacity for the set's defining features.

Basic and Applied Aspects of Color Tuning of Bioluminescence Systems

NASA Astrophysics Data System (ADS)

Ohmiya, Yoshihiro

2005-09-01

V. Viviani et al. [Biochemistry 38 (1999) 8271] were the first to succeed in cloning the red-emitting enzyme from the South American railroad worm, which is the only bioluminescent organism known to emit a red-colored light. The application of red bioluminescence has been our goal because the transmittance of longer-wavelength light is superior to that of the other colors for visualization of biological functions in living cells. Now, different color luciferases, which emit with wavelength maxima ranging from 400 to 630 nm, are available and are being used. For example, based on different color luciferases, Nakajima et al. developed a tricolor reporter in vitro assay system based on these different color luciferases in which the expression of three genes can be monitored simultaneously. On the other hand, bioluminescence resonance energy transfer (BRET) is a natural phenomenon caused by the intermolecular interaction between a bioluminescent protein and a fluorophore on a second protein, resulting in the light from the bioluminescence reaction having the spectrum of the fluorophore. Otsuji et al. [Anal. Biochem. 329 (2004) 230] showed that the change in the efficiency of energy transfer in intramolecular BRET can quantify cellular functions in living cells. In this review, I introduce the basic mechanisms of color tuning in bioluminescent systems and new applications based on color tuning in the life sciences.

MASSCLEANage-STELLAR CLUSTER AGES FROM INTEGRATED COLORS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popescu, Bogdan; Hanson, M. M., E-mail: popescb@mail.uc.ed, E-mail: margaret.hanson@uc.ed

2010-11-20

We present the recently updated and expanded MASSCLEANcolors, a database of 70 million Monte Carlo models selected to match the properties (metallicity, ages, and masses) of stellar clusters found in the Large Magellanic Cloud (LMC). This database shows the rather extreme and non-Gaussian distribution of integrated colors and magnitudes expected with different cluster age and mass and the enormous age degeneracy of integrated colors when mass is unknown. This degeneracy could lead to catastrophic failures in estimating age with standard simple stellar population models, particularly if most of the clusters are of intermediate or low mass, like in the LMC.more » Utilizing the MASSCLEANcolors database, we have developed MASSCLEANage, a statistical inference package which assigns the most likely age and mass (solved simultaneously) to a cluster based only on its integrated broadband photometric properties. Finally, we use MASSCLEANage to derive the age and mass of LMC clusters based on integrated photometry alone. First, we compare our cluster ages against those obtained for the same seven clusters using more accurate integrated spectroscopy. We find improved agreement with the integrated spectroscopy ages over the original photometric ages. A close examination of our results demonstrates the necessity of solving simultaneously for mass and age to reduce degeneracies in the cluster ages derived via integrated colors. We then selected an additional subset of 30 photometric clusters with previously well-constrained ages and independently derive their age using the MASSCLEANage with the same photometry with very good agreement. The MASSCLEANage program is freely available under GNU General Public License.« less

Site-Specific Three-Color Labeling of α-Synuclein via Conjugation to Uniquely Reactive Cysteines during Assembly by Native Chemical Ligation.

PubMed

Lee, Taehyung C; Moran, Crystal R; Cistrone, Philip A; Dawson, Philip E; Deniz, Ashok A

2018-04-12

Single-molecule fluorescence is widely used to study conformational complexity in proteins, and has proven especially valuable with intrinsically disordered proteins (IDPs). Protein studies using dual-color single-molecule Förster resonance energy transfer (smFRET) are now quite common, but many could benefit from simultaneous measurement of multiple distances through multi-color labeling. Such studies, however, have suffered from limitations in site-specific incorporation of more than two dyes per polypeptide. Here we present a fully site-specific three-color labeling scheme for α-synuclein, an IDP with important putative functions and links to Parkinson disease. The convergent synthesis combines native chemical ligation with regiospecific cysteine protection of expressed protein fragments to permit highly controlled labeling via standard cysteine-maleimide chemistry, enabling more global smFRET studies. Furthermore, this modular approach is generally compatible with recombinant proteins and expandable to accommodate even more complex experiments, such as by labeling with additional colors. Copyright © 2018 Elsevier Ltd. All rights reserved.

Immune challenges and visual signalling in tree frogs

NASA Astrophysics Data System (ADS)

Desprat, Julia L.; Lengagne, Thierry; Mondy, Nathalie

2017-04-01

In animals, mate-choice is often based on sexual signals that carry information and help the receiver make the best choice to improve the receiver's fitness. Orange visual sexual signals have been hypothesised to carry immune information because they are often due to carotenoid pigments which are also involved in immunity response. Although many studies have focused on the direct relationships between coloration and immunocompetence, few studies have simultaneously studied immunocompetent response and coloration variation after an immune challenge. We tested this hypothesis on starved and ad libitum-fed males of the European tree frog Hyla arborea. Our results show that male coloration is not a reliable indicator of its immune response capacity in this species. However, after an immune challenge induced by a PHA ( Phaseolus vulgaris phytohaemagglutinin) injection, starved males presented a significant coloration loss and this alteration was related to the immune response intensity. Taken together, these results suggest that the brighter (lighter) coloration may be used as a cue by female to exclude males with a recent immune challenge, due to diseases or parasites for example.

A color-corrected strategy for information multiplexed Fourier ptychographic imaging

NASA Astrophysics Data System (ADS)

Wang, Mingqun; Zhang, Yuzhen; Chen, Qian; Sun, Jiasong; Fan, Yao; Zuo, Chao

2017-12-01

Fourier ptychography (FP) is a novel computational imaging technique that provides both wide field of view (FoV) and high-resolution (HR) imaging capacity for biomedical imaging. Combined with information multiplexing technology, wavelength multiplexed (or color multiplexed) FP imaging can be implemented by lighting up R/G/B LED units simultaneously. Furthermore, a HR image can be recovered at each wavelength from the multiplexed dataset. This enhances the efficiency of data acquisition. However, since the same dataset of intensity measurement is used to recover the HR image at each wavelength, the mean value in each channel would converge to the same value. In this paper, a color correction strategy embedded in the multiplexing FP scheme is demonstrated, which is termed as color corrected wavelength multiplexed Fourier ptychography (CWMFP). Three images captured by turning on a LED array in R/G/B are required as priori knowledge to improve the accuracy of reconstruction in the recovery process. Using the reported technique, the redundancy requirement of information multiplexed FP is reduced. Moreover, the accuracy of reconstruction at each channel is improved with correct color reproduction of the specimen.

Insights from event-related potentials into the temporal and hierarchical organization of the ventral and dorsal streams of the visual system in selective attention.

PubMed

Martín-Loeches, M; Hinojosa, J A; Rubia, F J

1999-11-01

The temporal and hierarchical relationships between the dorsal and the ventral streams in selective attention are known only in relation to the use of spatial location as the attentional cue mediated by the dorsal stream. To improve this state of affairs, event-related brain potentials were recorded while subjects attended simultaneously to motion direction (mediated by the dorsal stream) and to a property mediated by the ventral stream (color or shape). At about the same time, a selection positivity (SP) started for attention mediated by both streams. However, the SP for color and shape peaked about 60 ms later than motion SP. Subsequently, a selection negativity (SN) followed by a late positive component (LPC) were found simultaneously for attention mediated by both streams. A hierarchical relationship between the two streams was not observed, but neither SN nor LPC for one property was completely insensitive to the values of the other property.

Do differences in sensitivity between native and invasive amphipods explain their coexistence in Lake Constance? A case study with lambda-cyhalothrin.

PubMed

Bundschuh, Mirco; Gergs, René; Schadt, Sebastian; Schulz, Ralf

2013-07-01

Invasive species are considered as one of the major threats for biodiversity worldwide. The Ponto-Caspian species Dikerogammarus villosus, for instance, spread throughout continental Europe and was recorded for the first time also within Lake Constance in 2003. Although D. villosus is a highly competitive species it was not capable of replacing the native Gammarus roeselii completely in this ecosystem, especially in the riparian zones of the highly agriculturally used island "Reichenau". As differences in pesticide sensitivity between both amphipod species may explain their distribution, the present study assessed the implication of the highly toxic pyrethroid lambda-cyhalothrin, which is authorized for application in the Lake Constance region, assuming the invasive species being more sensitive than the native one. However, both the feeding activity bioassays, which measured the leaf consumption over 7d (n=20), as well as the predation bioassay, which measured the predation rate upon Baetis nymphs in concert with the feeding activity on leaf material over 96 h (n=13), revealed an up to 5-fold higher tolerance of D. villosus towards lambda-cyhalothrin. These results suggest the investigated insecticide not being the trigger for the observed distribution pattern of both amphipod species. Hence, other factors like the diversity of habitat structures or the levels of ammonia may have facilitated the coexistence. Nevertheless, the present study uncovered a high leaf-shredding efficacy of the invasive species D. villosus suggesting that its role in the leaf decomposition process may have been underestimated in the past. Copyright © 2013 Elsevier Ltd. All rights reserved.

Colour Constancy Beyond the Classical Receptive Field.

PubMed

Akbarinia, Arash; Parraga, C Alejandro

2017-09-18

The problem of removing illuminant variations to preserve the colours of objects (colour constancy) has already been solved by the human brain using mechanisms that rely largely on centre-surround computations of local contrast. In this paper we adopt some of these biological solutions described by long known physiological findings into a simple, fully automatic, functional model (termed Adaptive Surround Modulation or ASM). In ASM, the size of a visual neuron's receptive field (RF) as well as the relationship with its surround varies according to the local contrast within the stimulus, which in turn determines the nature of the centre-surround normalisation of cortical neurons higher up in the processing chain. We modelled colour constancy by means of two overlapping asymmetric Gaussian kernels whose sizes are adapted based on the contrast of the surround pixels, resembling the change of RF size. We simulated the contrast-dependent surround modulation by weighting the contribution of each Gaussian according to the centre-surround contrast. In the end, we obtained an estimation of the illuminant from the set of the most activated RFs' outputs. Our results on three single-illuminant and one multi-illuminant benchmark datasets show that ASM is highly competitive against the state-of-the-art and it even outperforms learning-based algorithms in one case. Moreover, the robustness of our model is more tangible if we consider that our results were obtained using the same parameters for all datasets, that is, mimicking how the human visual system operates. These results might provide an insight on how dynamical adaptation mechanisms contribute to make object's colours appear constant to us.

African American race and HIV virological suppression: beyond disparities in clinic attendance.

PubMed

Howe, Chanelle J; Napravnik, Sonia; Cole, Stephen R; Kaufman, Jay S; Adimora, Adaora A; Elston, Beth; Eron, Joseph J; Mugavero, Michael J

2014-06-15

Racial disparities in clinic attendance may contribute to racial disparities in plasma human immunodeficiency virus type 1 : HIV-1) RNA levels among HIV-positive patients in care. Data from 946 African American and 535 Caucasian patients receiving HIV care at the University of North Carolina Center for AIDS Research HIV clinic between January 1, 1999, and August 1, 2012, were used to estimate the association between African American race and HIV virological suppression (i.e., undetectable HIV-1 RNA) when racial disparities in clinic attendance were lessened. Clinic attendance was measured as the proportion of scheduled clinic appointments attended (i.e., visit adherence) or the proportion of six 4-month intervals with at least 1 attended scheduled clinic appointment (i.e., visit constancy). In analyses accounting for patient characteristics, the risk ratio for achieving suppression when comparing African Americans with Caucasians was 0.91 (95% confidence interval: 0.85, 0.98). Lessening disparities in adherence or constancy lowered disparities in virological suppression by up to 44.4% and 11.1%, respectively. Interventions that lessen disparities in adherence may be more effective in eliminating disparities in suppression than interventions that lessen disparities in constancy. Given that gaps in care were limited to be no more than 2 years for both attendance measures, the impact of lessening disparities in adherence may be overstated. © The Author 2014. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Design and fabrication of dichroic mirrors for color separation and recombination of the Kr-Ar laser (white laser)

NASA Astrophysics Data System (ADS)

Park, Jungho; Park, Youngjun; Hwang, Young M.

1997-10-01

Cut-off filters reject all the radiation below and transmit all the above a certain wavelength and vice versa. In this paper, we will study the design and fabrication of a short wave pass or a long wave pass dichroic mirrors for color separation and recombination from the R.G.B. color beam source. In the laser display system, color separation and recombination is very important. We designed the coating layers so that the best performance may be obtained from a 45 degree incident s-polarized light. The following fabrication specification is satisfied in our color separation/recombination of the Kr-Ar laser source. The first dichroic mirror for the blue color separation, maximized on reflectance and transmittance as R > 99% in the blue regions (400 approximately 490 nm) and T > 90% in the green and red region (510 approximately 700 nm). The second dichroic mirror for the color recombination maximized the reflectance and transmittance as R > 99% in the range of 510 approximately 700 nm and T > 90% in the blue color region. In the third dichroic mirror for which it used the color separation and recombination of the green and red simultaneously, maximized the reflectance and transmittance as R > 99% in the green region (510 approximately 560 nm) and T > 90% in the red region. These fabricated mirrors were applied in our laser display projection system. We obtained an excellent result.

Asynchronous origins of ectomycorrhizal clades of Agaricales.

PubMed

Ryberg, Martin; Matheny, P Brandon

2012-05-22

The ectomycorrhizal (ECM) symbiosis is the most widespread biotrophic nutritional mode in mushroom-forming fungi. ECM fungi include, though are not limited to, about 5000 described species of Agaricales from numerous, independently evolved lineages. Two central hypotheses suggest different explanations for the origin of ECM fungal diversity: (i) dual origins, initially with the Pinaceae in the Jurassic and later with angiosperms during the Late Cretaceous, and (ii) a simultaneous and convergent radiation of ECM lineages in response to cooling climate during the Palaeogene and advancing temperate ECM plant communities. Neither of these hypotheses is supported here. While we demonstrate support for asynchronous origins of ECM Agaricales, the timing of such events appears to have occurred more recently than suggested by the first hypothesis, first during the Cretaceous and later during the Palaeogene. We are also unable to reject models of rate constancy, which suggests that the diversity of ECM Agaricales is not a consequence of convergent rapid radiations following evolutionary transitions from saprotrophic to ECM habits. ECM lineages of Agaricales differ not only in age, but also in rates of diversification and rate of substitution at nuclear ribosomal RNA loci. These results question the biological uniformity of the ECM guild.

Asynchronous origins of ectomycorrhizal clades of Agaricales

PubMed Central

Ryberg, Martin; Matheny, P. Brandon

2012-01-01

The ectomycorrhizal (ECM) symbiosis is the most widespread biotrophic nutritional mode in mushroom-forming fungi. ECM fungi include, though are not limited to, about 5000 described species of Agaricales from numerous, independently evolved lineages. Two central hypotheses suggest different explanations for the origin of ECM fungal diversity: (i) dual origins, initially with the Pinaceae in the Jurassic and later with angiosperms during the Late Cretaceous, and (ii) a simultaneous and convergent radiation of ECM lineages in response to cooling climate during the Palaeogene and advancing temperate ECM plant communities. Neither of these hypotheses is supported here. While we demonstrate support for asynchronous origins of ECM Agaricales, the timing of such events appears to have occurred more recently than suggested by the first hypothesis, first during the Cretaceous and later during the Palaeogene. We are also unable to reject models of rate constancy, which suggests that the diversity of ECM Agaricales is not a consequence of convergent rapid radiations following evolutionary transitions from saprotrophic to ECM habits. ECM lineages of Agaricales differ not only in age, but also in rates of diversification and rate of substitution at nuclear ribosomal RNA loci. These results question the biological uniformity of the ECM guild. PMID:22171078

Two-color short-pulse laser altimeter measurements of ocean surface backscatter

NASA Technical Reports Server (NTRS)

Abshire, James B.; Mcgarry, Jan F.

1987-01-01

The timing and correlation properties of pulsed laser backscatter from the ocean surface have been measured with a two-color short-pulse laser altimeter. The Nd:YAG laser transmitted 70- and 35-ps wide pulses simultaneously at 532 and 355 nm at nadir, and the time-resolved returns were recorded by a receiver with 800-ps response time. The time-resolved backscatter measured at both 330-m and 1291-m altitudes showed little pulse broadening due to the submeter laser spot size. The differential delay of the 355-nm and 532-nm backscattered waveforms were measured with a rms error of about 75 ps. The change in aircraft altitudes also permitted the change in atmospheric pressure to be estimated by using the two-color technique.

LED Surgical Task Lighting Scoping Study: A Hospital Energy Alliance Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tuenge, Jason R.

Tungsten-halogen (halogen) lamps have traditionally been used to light surgical tasks in hospitals, even though they are in many respects ill-suited to the application due to the large percentage of radiant energy outside the visible spectrum and issues with color rendering/quality. Light-emitting diode (LED) technology offers potential for adjustable color and improved color rendition/quality, while simultaneously reducing side-effects from non-visible radiant energy. It also has the potential for significant energy savings, although this is a fairly narrow application in the larger commercial building energy use sector. Based on analysis of available products and Hospital Energy Alliance member interest, it ismore » recommended that a product specification and field measurement procedure be developed for implementation in demonstration projects.« less

Women and Leadership in Sport.

ERIC Educational Resources Information Center

DeFrantz, Anita L.

1988-01-01

The history of women's participation in the Olympics is reviewed briefly. Women in positions of leadership of the International Olympic Committee and other sport organizations are mentioned. The lives of Constance Applebee, Eva Auchincloss, Rusty Kanogi, and Wilma Rudolph are highlighted. (MT)

The guidance of spatial attention during visual search for color combinations and color configurations.

PubMed

Berggren, Nick; Eimer, Martin

2016-09-01

Representations of target-defining features (attentional templates) guide the selection of target objects in visual search. We used behavioral and electrophysiological measures to investigate how such search templates control the allocation of attention in search tasks where targets are defined by the combination of 2 colors or by a specific spatial configuration of these colors. Target displays were preceded by spatially uninformative cue displays that contained items in 1 or both target-defining colors. Experiments 1 and 2 demonstrated that, during search for color combinations, attention is initially allocated independently and in parallel to all objects with target-matching colors, but is then rapidly withdrawn from objects that only have 1 of the 2 target colors. In Experiment 3, targets were defined by a particular spatial configuration of 2 colors, and could be accompanied by nontarget objects with a different configuration of the same colors. Attentional guidance processes were unable to distinguish between these 2 types of objects. Both attracted attention equally when they appeared in a cue display, and both received parallel focal-attentional processing and were encoded into working memory when they were presented in the same target display. Results demonstrate that attention can be guided simultaneously by multiple features from the same dimension, but that these guidance processes have no access to the spatial-configural properties of target objects. They suggest that attentional templates do not represent target objects in an integrated pictorial fashion, but contain separate representations of target-defining features. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Four-color single-molecule fluorescence with noncovalent dye labeling to monitor dynamic multimolecular complexes.

PubMed

DeRocco, Vanessa; Anderson, Trevor; Piehler, Jacob; Erie, Dorothy A; Weninger, Keith

2010-11-01

To enable studies of conformational changes within multimolecular complexes, we present a simultaneous, four-color single molecule fluorescence methodology implemented with total internal reflection illumination and camera-based, wide-field detection. We further demonstrate labeling histidine-tagged proteins noncovalently with Tris-nitrilotriacetic acid (Tris-NTA)-conjugated dyes to achieve single molecule detection. We combine these methods to colocalize the mismatch repair protein MutSα on DNA while monitoring MutSα-induced DNA bending using Förster resonance energy transfer (FRET) and to monitor assembly of membrane-tethered SNARE protein complexes.

Four-color single molecule fluorescence with noncovalent dye labeling to monitor dynamic multimolecular complexes

PubMed Central

DeRocco, Vanessa C.; Anderson, Trevor; Piehler, Jacob; Erie, Dorothy A.; Weninger, Keith

2010-01-01

To allow studies of conformational changes within multi-molecular complexes, we present a simultaneous, 4-color single molecule fluorescence methodology implemented with total internal reflection illumination and camera based, wide-field detection. We further demonstrate labeling histidine-tagged proteins non-covalently with tris-Nitrilotriacetic acid (tris-NTA) conjugated dyes to achieve single molecule detection. We combine these methods to co-localize the mismatch repair protein MutSα on DNA while monitoring MutSα-induced DNA bending using Förster resonance energy transfer (FRET) and to monitor assembly of membrane-tethered SNARE protein complexes. PMID:21091445

An eye tracking investigation of color-location binding in infants' visual short-term memory.

PubMed

Oakes, Lisa M; Baumgartner, Heidi A; Kanjlia, Shipra; Luck, Steven J

2017-01-01

Two experiments examined 8- and 10-month-old infants' ( N = 71) binding of object identity (color) and location information in visual short-term memory (VSTM) using a one-shot change detection task . Building on previous work using the simultaneous streams change detection task, we confirmed that 8- and 10-month-old infants are sensitive to changes in binding between identity and location in VSTM. Further, we demonstrated that infants recognize specifically what changed in these events. Thus, infants' VSTM for binding is robust and can be observed in different procedures and with different stimuli.

Reliability generalization: a viable key for establishing validity generalization

NASA Technical Reports Server (NTRS)

Kennedy, R. S.; Turnage, J. J.

1991-01-01

Even with radical restriction of range, reliability coefficients from 10 studies gave an average interstudy value of .74, suggesting constancy of reliability over diverse experiments. A value from a new test can help index reliability of tests not previously studied.

Reading Recovery.

ERIC Educational Resources Information Center

Jones, Joanna R., Ed.

1992-01-01

This issue of the Arizona Reading Journal focuses on the theme "reading recovery" and includes the following articles: "Why Is an Inservice Programme for Reading Recovery Teachers Necessary?" (Marie M. Clay); "What Is Reading Recovery?" (Gay Su Pinnell); "Teaching a Hard To Teach Child" (Constance A.…

A Physiologist's View of Homeostasis

ERIC Educational Resources Information Center

Modell, Harold; Cliff, William; Michael, Joel; McFarland, Jenny; Wenderoth, Mary Pat; Wright, Ann

2015-01-01

Homeostasis is a core concept necessary for understanding the many regulatory mechanisms in physiology. Claude Bernard originally proposed the concept of the constancy of the "milieu interieur," but his discussion was rather abstract. Walter Cannon introduced the term "homeostasis" and expanded Bernard's notion of…

Research on Design of Tri-color Shift Device

NASA Astrophysics Data System (ADS)

Xu, Ping; Yuan, Xia; Huang, Haixuan; Yang, Tuo; Huang, Yanyan; Zhu, Tengfei; Tang, Shaotuo; Peng, Wenda

2016-11-01

An azimuth-tuned tri-color shift device based on an embedded subwavelength one-dimensional rectangular structure with single period is proposed. High reflection efficiencies for both TE and TM polarizations can be achieved simultaneously. Under an oblique incidence of 60°, the reflection efficiencies can reach up to 85, 86, and 100 % in blue (azimuth of 24°), green (azimuth of 63°), and red (azimuth of 90°) waveband, respectively. Furthermore, the laws of influence of device period, groove depth, coating thickness, and incident angle on reflection characteristics are investigated and exposed, and feasibility of the device is demonstrated. The proposed device realizes tri-color shift for natural light using a simple structure. It exhibits high efficiency as well as good security. Such a device can be fabricated by the existing embossing and coating technique. All these break through the limit of bi-color shift anti-counterfeiting technology and have great applications in the field of optically variable image security.

Real-time biodetection using a smartphone-based dual-color surface plasmon resonance sensor

NASA Astrophysics Data System (ADS)

Liu, Qiang; Yuan, Huizhen; Liu, Yun; Wang, Jiabin; Jing, Zhenguo; Peng, Wei

2018-04-01

We proposed a compact and cost-effective red-green dual-color fiber optic surface plasmon resonance (SPR) sensor based on the smartphone. Inherent color selectivity of phone cameras was utilized for real-time monitoring of red and green color channels simultaneously, which can reduce the chance of false detection and improve the sensitivity. Because there are no external prisms, complex optical lenses, or diffraction grating, simple optical configuration is realized. It has a linear response in a refractive index range of 1.326 to 1.351 (R2 = 0.991) with a resolution of 2.3 × 10 - 4 RIU. We apply it for immunoglobulin G (IgG) concentration measurement. Experimental results demonstrate that a linear SPR response was achieved for IgG concentrations varying from 0.02 to 0.30 mg / ml with good repeatability. It may find promising applications in the fields of public health and environment monitoring owing to its simple optics design and applicability in real-time, label-free biodetection.

Corrections to MODIS Terra Calibration and Polarization Trending Derived from Ocean Color Products

NASA Technical Reports Server (NTRS)

Meister, Gerhard; Eplee, Robert E.; Franz, Bryan A.

2014-01-01

Remotely sensed ocean color products require highly accurate top-of-atmosphere (TOA) radiances, on the order of 0.5% or better. Due to incidents both prelaunch and on-orbit, meeting this requirement has been a consistent problem for the MODIS instrument on the Terra satellite, especially in the later part of the mission. The NASA Ocean Biology Processing Group (OBPG) has developed an approach to correct the TOA radiances of MODIS Terra using spatially and temporally averaged ocean color products from other ocean color sensors (such as the SeaWiFS instrument on Orbview-2 or the MODIS instrument on the Aqua satellite). The latest results suggest that for MODIS Terra, both linear polarization parameters of the Mueller matrix are temporally evolving. A change to the functional form of the scan angle dependence improved the quality of the derived coefficients. Additionally, this paper demonstrates that simultaneously retrieving polarization and gain parameters improves the gain retrieval (versus retrieving the gain parameter only).

Ground-based Spectroscopic Observation of Jovian Surface Structures by Using the Portable Spectrometer.

NASA Astrophysics Data System (ADS)

Iwasaki, K.; Ito, H.; Tabe, I.; Hirota, S.; Suzuki, H.

2017-12-01

Stripe patterns called belts or zones with various colors persist on Jovian surface. Anticyclonic vortices called an oval with various scales and colors are maintained and drifted in the boundary between zones and belts. Some ovals have different colors despite they are formed simultaneously in the same latitude region. Color changes of ovals after an interaction with other ovals have been also reported [Sánchez-Lavega et al., JGR, 2013]. The great red spot (GRS) is one of the most remarkable structures in the Jupiter and recognized since 300 years ago by sketch and photographic observations. Recently, NASA spacecraft, JUNO has revealed more complex and fine features with various colors. A close relationship between dynamics of Jovian atmosphere and local colors is well known [Sánchez-Lavega et al., JGR, 2013] though detailed mechanisms connecting them are not fully understood. Thus, the color of the each structures is thought to be one of the keys to investigate dynamics of the Jovian atmosphere. In this study, ground-based spectroscopic observations focusing on Jovian surface structures have been conducted since December 2015. The observation is carried out by combining a telescope with a small unit for spectroscopy consists of a CCD camera and a spectrometer. The spectrometer can measure a spectrum of a selected area within an image data simultaneously obtained by the CCD camera. Dimensions and weight of the spectroscopy are only 18cm × 14cm × 4cm and 300 g, respectively. This high portability of the spectrometer enables flexible observations; we can bring the spectrometer to a public observatory which has a large telescope in a location with high clear skies rate in desired observation period. The spectra are converted and corrected to an absolute radiance at the top of atmosphere, by using a radiometric calibration data obtained with an integrating sphere and measured extinction coefficients of the local atmosphere. In this talk, temporal variations in the spectrum of representative Jovian structures such as NEB, EZ, SEB, GRS observed by using the spectrometer during December 2015 to July 2017 are reported. A comparison with the past spaceborn observation conducted by the multiband camera onboard Cassini spacecraft [Ordonez-Etxeberria et al., Icarus, 2015] is also performed for verification of the observations.

Extending color primary set in spectral vector error diffusion by multilevel halftoning

NASA Astrophysics Data System (ADS)

Norberg, Ole; Nyström, Daniel

2013-02-01

Ever since its origin in the late 19th century, a color reproduction technology has relied on a trichromatic color reproduction approach. This has been a very successful method and also fundamental for the development of color reproduction devices. Trichromatic color reproduction is sufficient to approximate the range of colors perceived by the human visual system. However, tricromatic systems only have the ability to match colors when the viewing illumination for the reproduction matches that of the original. Furthermore, the advancement of digital printing technology has introduced printing systems with additional color channels. These additional color channels are used to extend the tonal range capabilities in light and dark regions and to increase color gamut. By an alternative approach the addition color channels can also be used to reproduce the spectral information of the original color. A reproduced spectral match will always correspond to original independent of lighting situation. On the other hand, spectral color reproductions also introduce a more complex color processing by spectral color transfer functions and spectral gamut mapping algorithms. In that perspective, spectral vector error diffusion (sVED) look like a tempting approach with a simple workflow where the inverse color transfer function and halftoning is performed simultaneously in one single operation. Essential for the sVED method are the available color primaries, created by mixing process colors. Increased numbers of as well as optimal spectral characteristics of color primaries are expected to significantly improve the color accuracy of the spectral reproduction. In this study, sVED in combination with multilevel halftoning has been applied on a ten channel inkjet system. The print resolution has been reduced and the underlying physical high resolution of the printer has been used to mix additional primaries. With ten ink channels and halfton cells built-up by 2x2 micro dots where each micro dot can be a combination of all ten inks the number of possible ink combinations gets huge. Therefore, the initial study has been focused on including lighter colors to the intrinsic primary set. Results from this study shows that by this approach the color reproduction accuracy increases significantly. The RMS spectral difference to target color for multilevel halftoning is less than 1/6 of the difference achieved by binary halftoning.

Implementation of a microprocessor-based visual-evoked cortical potential recording and analysis system.

PubMed

Wilson, A; Fram, D; Sistar, J

1981-06-01

An Imsai 8080 microcomputer is being used to simultaneously generate a color graphics stimulus display and to record visual-evoked cortical potentials. A brief description of the hardware and software developed for this system is presented. Data storage and analysis techniques are also discussed.

Estimation of kinetic parameters of anthocyanins and color degradation in vitamin C fortified cranberry juice during storage.

PubMed

Roidoung, Sunisa; Dolan, Kirk D; Siddiq, Muhammad

2017-04-01

Color degradation in cranberry juice during storage is the most common consumer complaint. To enhance nutritional quality, juice is typically fortified with vitamin C. This study determined effect of gallic acid, a natural antioxidant, for the preservation of anthocyanins (ACYs) and color, and estimated kinetics of ACYs and color degradation. Juice, fortified with 40-80mg/100mL vitamin C and 0-320mg/100mL gallic acid, was pasteurized at 85°C for 1min and stored at 23°C for 16days. Total monomeric anthocyanins and red color intensity were evaluated spectrophotometrically and data were used to determine degradation rate constants (k values) and order of reaction (n) of ACYs and color. Due to high correlation, k and n could not be estimated simultaneously. To overcome this difficulty, both n and k were held at different constant values in separate analyses to allow accurate estimation of each. Parameters n and k were modeled empirically as functions of vitamin C, and of vitamin C and gallic acid, respectively. Reaction order n ranged from 1.2 to 4.4, and decreased with increasing vitamin C concentration. The final model offers an effective tool that could be used for predicting ACYs and color retention in cranberry juice during storage. Copyright © 2017. Published by Elsevier Ltd.

Conspicuous female ornamentation and tests of male mate preference in threespine sticklebacks (Gasterosteus aculeatus).

PubMed

Wright, Daniel Shane; Pierotti, Michele E R; Rundle, Howard D; McKinnon, Jeffrey S

2015-01-01

Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus) populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope) of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks.

Conspicuous Female Ornamentation and Tests of Male Mate Preference in Threespine Sticklebacks (Gasterosteus aculeatus)

PubMed Central

Wright, Daniel Shane; Pierotti, Michele E. R.; Rundle, Howard D.; McKinnon, Jeffrey S.

2015-01-01

Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus) populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope) of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks. PMID:25806520

Commissioning and quality assurance for VMAT delivery systems: An efficient time-resolved system using real-time EPID imaging.

PubMed

Zwan, Benjamin J; Barnes, Michael P; Hindmarsh, Jonathan; Lim, Seng B; Lovelock, Dale M; Fuangrod, Todsaporn; O'Connor, Daryl J; Keall, Paul J; Greer, Peter B

2017-08-01

An ideal commissioning and quality assurance (QA) program for Volumetric Modulated Arc Therapy (VMAT) delivery systems should assess the performance of each individual dynamic component as a function of gantry angle. Procedures within such a program should also be time-efficient, independent of the delivery system and be sensitive to all types of errors. The purpose of this work is to develop a system for automated time-resolved commissioning and QA of VMAT control systems which meets these criteria. The procedures developed within this work rely solely on images obtained, using an electronic portal imaging device (EPID) without the presence of a phantom. During the delivery of specially designed VMAT test plans, EPID frames were acquired at 9.5 Hz, using a frame grabber. The set of test plans was developed to individually assess the performance of the dose delivery and multileaf collimator (MLC) control systems under varying levels of delivery complexities. An in-house software tool was developed to automatically extract features from the EPID images and evaluate the following characteristics as a function of gantry angle: dose delivery accuracy, dose rate constancy, beam profile constancy, gantry speed constancy, dynamic MLC positioning accuracy, MLC speed and acceleration constancy, and synchronization between gantry angle, MLC positioning and dose rate. Machine log files were also acquired during each delivery and subsequently compared to information extracted from EPID image frames. The largest difference between measured and planned dose at any gantry angle was 0.8% which correlated with rapid changes in dose rate and gantry speed. For all other test plans, the dose delivered was within 0.25% of the planned dose for all gantry angles. Profile constancy was not found to vary with gantry angle for tests where gantry speed and dose rate were constant, however, for tests with varying dose rate and gantry speed, segments with lower dose rate and higher gantry speed exhibited less profile stability. MLC positional accuracy was not observed to be dependent on the degree of interdigitation. MLC speed was measured for each individual leaf and slower leaf speeds were shown to be compensated for by lower dose rates. The test procedures were found to be sensitive to 1 mm systematic MLC errors, 1 mm random MLC errors, 0.4 mm MLC gap errors and synchronization errors between the MLC, dose rate and gantry angle controls systems of 1°. In general, parameters measured by both EPID and log files agreed with the plan, however, a greater average departure from the plan was evidenced by the EPID measurements. QA test plans and analysis methods have been developed to assess the performance of each dynamic component of VMAT deliveries individually and as a function of gantry angle. This methodology relies solely on time-resolved EPID imaging without the presence of a phantom and has been shown to be sensitive to a range of delivery errors. The procedures developed in this work are both comprehensive and time-efficient and can be used for streamlined commissioning and QA of VMAT delivery systems. © 2017 American Association of Physicists in Medicine.

Very-long-term and short-term chromatic adaptation: are their influences cumulative?

PubMed

Belmore, Suzanne C; Shevell, Steven K

2011-02-09

Very-long-term (VLT) chromatic adaptation results from exposure to an altered chromatic environment for days or weeks. Color shifts from VLT adaptation are observed hours or days after leaving the altered environment. Short-term chromatic adaptation, on the other hand, results from exposure for a few minutes or less, with color shifts measured within seconds or a few minutes after the adapting light is extinguished; recovery to the pre-adapted state is complete in less than an hour. Here, both types of adaptation were combined. All adaptation was to reddish-appearing long-wavelength light. Shifts in unique yellow were measured following adaptation. Previous studies demonstrate shifts in unique yellow due to VLT chromatic adaptation, but shifts from short-term chromatic adaptation to comparable adapting light can be far greater than from VLT adaptation. The question considered here is whether the color shifts from VLT adaptation are cumulative with large shifts from short-term adaptation or, alternatively, does simultaneous short-term adaptation eliminate color shifts caused by VLT adaptation. The results show the color shifts from VLT and short-term adaptation together are cumulative, which indicates that both short-term and very-long-term chromatic adaptation affect color perception during natural viewing. Copyright © 2010 Elsevier Ltd. All rights reserved.

Enhancement of low light level images using color-plus-mono dual camera.

PubMed

Jung, Yong Ju

2017-05-15

In digital photography, the improvement of imaging quality in low light shooting is one of the users' needs. Unfortunately, conventional smartphone cameras that use a single, small image sensor cannot provide satisfactory quality in low light level images. A color-plus-mono dual camera that consists of two horizontally separate image sensors, which simultaneously captures both a color and mono image pair of the same scene, could be useful for improving the quality of low light level images. However, an incorrect image fusion between the color and mono image pair could also have negative effects, such as the introduction of severe visual artifacts in the fused images. This paper proposes a selective image fusion technique that applies an adaptive guided filter-based denoising and selective detail transfer to only those pixels deemed reliable with respect to binocular image fusion. We employ a dissimilarity measure and binocular just-noticeable-difference (BJND) analysis to identify unreliable pixels that are likely to cause visual artifacts during image fusion via joint color image denoising and detail transfer from the mono image. By constructing an experimental system of color-plus-mono camera, we demonstrate that the BJND-aware denoising and selective detail transfer is helpful in improving the image quality during low light shooting.

Why Have Multiple Plastic Responses? Interactions between Color Change and Heat Avoidance Behavior in Battus philenor Larvae.

PubMed

Nielsen, Matthew E; Papaj, Daniel R

2017-06-01

Having multiple plastic responses to a change in the environment, such as increased temperature, can be adaptive for two major reasons: synergy (the plastic responses perform better when expressed simultaneously) or complementarity (each plastic response provides a greater net benefit in a different environmental context). We investigated these hypotheses for two forms of temperature-induced plasticity of Battus philenor caterpillars in southern Arizona populations: color change (from black to red at high temperatures) and heat avoidance behavior (movement from host to elevated refuges at high host temperatures). Field assays using aluminum models showed that the cooling effect of the red color is greatly reduced in a refuge position relative to that on a host. Field assays with live caterpillars demonstrated that refuge seeking is much more important for survival under hot conditions than coloration; however, in those assays, red coloration reduced the need to seek refuges. Our results support the complementarity hypothesis: refuge seeking facilitates survival during daily temperature peaks, while color change reduces the need to leave the host over longer warm periods. We propose that combinations of rapid but costly short-term behavioral responses and slow but efficient long-term morphological responses may be common when coping with temperature change.

Visual fields and eye morphology support color vision in a color-changing crab-spider.

PubMed

Insausti, Teresita C; Defrize, Jérémy; Lazzari, Claudio R; Casas, Jérôme

2012-03-01

Vision plays a major role in many spiders, being involved in prey hunting, orientation or substrate choice, among others. In Misumena vatia, which experiences morphological color changes, vision has been reported to be involved in substrate color matching. Electrophysiological evidence reveals that at least two types of photoreceptors are present in this species, but these data are not backed up by morphological evidence. This work analyzes the functional structure of the eyes of this spider and relates it to its color-changing abilities. A broad superposition of the visual field of the different eyes was observed, even between binocular regions of principal and secondary eyes. The frontal space is simultaneously analyzed by four eyes. This superposition supports the integration of the visual information provided by the different eye types. The mobile retina of the principal eyes of this spider is organized in three layers of three different types of rhabdoms. The third and deepest layer is composed by just one large rhabdom surrounded by dark screening pigments that limit the light entry. The three pairs of secondary eyes have all a single layer of rhabdoms. Our findings provide strong support for an involvement of the visual system in color matching in this spider. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Psychoanalytic Study of the Child, Volume XXIV.

ERIC Educational Resources Information Center

Eissler, Ruth S.; And Others

Articles on psychoanalytic theory concern libidinal object constancy and mental representation, the unrememberable and unforgettable (repression), and the motive, meaning, and causality of anthropomorphism. Discussions of normal and pathological development include the following: levels of verbal communication in the schizophrenic child, a review…

Epitaxial Growth of Hetero-Ln-MOF Hierarchical Single Crystals for Domain- and Orientation-Controlled Multicolor Luminescence 3D Coding Capability.

PubMed

Pan, Mei; Zhu, Yi-Xuan; Wu, Kai; Chen, Ling; Hou, Ya-Jun; Yin, Shao-Yun; Wang, Hai-Ping; Fan, Ya-Nan; Su, Cheng-Yong

2017-11-13

Core-shell or striped heteroatomic lanthanide metal-organic framework hierarchical single crystals were obtained by liquid-phase anisotropic epitaxial growth, maintaining identical periodic organization while simultaneously exhibiting spatially segregated structure. Different types of domain and orientation-controlled multicolor photophysical models are presented, which show either visually distinguishable or visible/near infrared (NIR) emissive colors. This provides a new bottom-up strategy toward the design of hierarchical molecular systems, offering high-throughput and multiplexed luminescence color tunability and readability. The unique capability of combining spectroscopic coding with 3D (three-dimensional) microscale spatial coding is established, providing potential applications in anti-counterfeiting, color barcoding, and other types of integrated and miniaturized optoelectronic materials and devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Demosaiced pixel super-resolution in digital holography for multiplexed computational color imaging on-a-chip (Conference Presentation)

NASA Astrophysics Data System (ADS)

Wu, Yichen; Zhang, Yibo; Luo, Wei; Ozcan, Aydogan

2017-03-01

Digital holographic on-chip microscopy achieves large space-bandwidth-products (e.g., >1 billion) by making use of pixel super-resolution techniques. To synthesize a digital holographic color image, one can take three sets of holograms representing the red (R), green (G) and blue (B) parts of the spectrum and digitally combine them to synthesize a color image. The data acquisition efficiency of this sequential illumination process can be improved by 3-fold using wavelength-multiplexed R, G and B illumination that simultaneously illuminates the sample, and using a Bayer color image sensor with known or calibrated transmission spectra to digitally demultiplex these three wavelength channels. This demultiplexing step is conventionally used with interpolation-based Bayer demosaicing methods. However, because the pixels of different color channels on a Bayer image sensor chip are not at the same physical location, conventional interpolation-based demosaicing process generates strong color artifacts, especially at rapidly oscillating hologram fringes, which become even more pronounced through digital wave propagation and phase retrieval processes. Here, we demonstrate that by merging the pixel super-resolution framework into the demultiplexing process, such color artifacts can be greatly suppressed. This novel technique, termed demosaiced pixel super-resolution (D-PSR) for digital holographic imaging, achieves very similar color imaging performance compared to conventional sequential R,G,B illumination, with 3-fold improvement in image acquisition time and data-efficiency. We successfully demonstrated the color imaging performance of this approach by imaging stained Pap smears. The D-PSR technique is broadly applicable to high-throughput, high-resolution digital holographic color microscopy techniques that can be used in resource-limited-settings and point-of-care offices.

Objective criteria for acceptability and constancy tests of digital subtraction angiography.

PubMed

de las Heras, Hugo; Torres, Ricardo; Fernández-Soto, José Miguel; Vañó, Eliseo

2016-01-01

Demonstrate an objective procedure to quantify image quality in digital subtraction angiography (DSA) and suggest thresholds for acceptability and constancy tests. Series of images were obtained in a DSA system simulating a small (paediatric) and a large patient using the dynamic phantom described in the IEC and DIN standards for acceptance tests of DSA equipment. Image quality was quantified using measurements of contrast-to-noise ratio (CNR). Overall scores combining the CNR of 10-100 mg/ml Iodine at a vascular diameter of 1-4 mm in a homogeneous background were defined. Phantom entrance surface air kerma (Ka,e) was measured with an ionisation chamber. The visibility of a low-contrast vessel in DSA images has been identified with a CNR value of 0.50 ± 0.03. Despite using 14 times more Ka,e (8.85 vs 0.63 mGy/image), the protocol for large patients showed a decrease in the overall score CNRsum of 67% (4.21 ± 0.06 vs 2.10 ± 0.05). The uncertainty in the results of the objective method was below 5%. Objective evaluation of DSA images using CNR is feasible with dedicated phantom measurements. An objective methodology has been suggested for acceptance tests compliant with the IEC/DIN standards. The defined overall scores can serve to fix a reproducible baseline for constancy tests, as well as to study the device stability within one acquisition series and compare different imaging protocols. This work provides aspects that have not been included in the recent European guidelines on Criteria for Acceptability of Medical Radiological Equipment. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

CONSTANCES: a general prospective population-based cohort for occupational and environmental epidemiology: cohort profile.

PubMed

Goldberg, Marcel; Carton, Matthieu; Descatha, Alexis; Leclerc, Annette; Roquelaure, Yves; Santin, Gaëlle; Zins, Marie

2017-01-01

WHY THE COHORT WAS SET UP?: CONSTANCES is a general-purpose cohort with a focus on occupational and environmental factors. CONSTANCES was designed as a randomly selected sample of French adults aged 18-69 years at inception; 200 000 participants will be included. At enrolment, the participants are invited to complete questionnaires and to attend a health screening centre (HSC) for a health examination. A biobank will be set up. The follow-up includes an yearly self-administered questionnaire, a periodic visit to an HSC and linkage to social and national health administrative databases. Data collected for participants include social and demographic characteristics, socioeconomic status, life events and behaviours. Regarding occupational and environmental factors, a wealth of data on organisational, chemical, biological, biomechanical and psychosocial lifelong exposure, as well as residential characteristics, are collected at enrolment and during follow-up. The health data cover a wide spectrum: self-reported health scales, reported prevalent and incident diseases, long-term chronic diseases and hospitalisations, sick-leaves, handicaps, limitations, disabilities and injuries, healthcare usage and services provided, and causes of death. To take into account non-participation and attrition, a random cohort of non-participants was set up and will be followed through the same national databases as participants. Inclusions begun at the end of 2012 and more than 110 000 participants were already included by September 2016. Several projects on occupational and environmental risks already applied to a public call for nested research projects. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

3-Dimensional Scene Perception during Active Electrolocation in a Weakly Electric Pulse Fish

PubMed Central

von der Emde, Gerhard; Behr, Katharina; Bouton, Béatrice; Engelmann, Jacob; Fetz, Steffen; Folde, Caroline

2010-01-01

Weakly electric fish use active electrolocation for object detection and orientation in their environment even in complete darkness. The African mormyrid Gnathonemus petersii can detect object parameters, such as material, size, shape, and distance. Here, we tested whether individuals of this species can learn to identify 3-dimensional objects independently of the training conditions and independently of the object's position in space (rotation-invariance; size-constancy). Individual G. petersii were trained in a two-alternative forced-choice procedure to electrically discriminate between a 3-dimensional object (S+) and several alternative objects (S−). Fish were then tested whether they could identify the S+ among novel objects and whether single components of S+ were sufficient for recognition. Size-constancy was investigated by presenting the S+ together with a larger version at different distances. Rotation-invariance was tested by rotating S+ and/or S− in 3D. Our results show that electrolocating G. petersii could (1) recognize an object independently of the S− used during training. When only single components of a complex S+ were offered, recognition of S+ was more or less affected depending on which part was used. (2) Object-size was detected independently of object distance, i.e. fish showed size-constancy. (3) The majority of the fishes tested recognized their S+ even if it was rotated in space, i.e. these fishes showed rotation-invariance. (4) Object recognition was restricted to the near field around the fish and failed when objects were moved more than about 4 cm away from the animals. Our results indicate that even in complete darkness our G. petersii were capable of complex 3-dimensional scene perception using active electrolocation. PMID:20577635

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keller, J; Lockamy, V; Harrison, A

Purpose: To support radiobiological research with the Xstrahl small animal radiation research platform (SARRP) by developing a simple and effective method using commercially available optically stimulated luminescent dosimeters (OSLDs) that ensures dose output consistency. Methods: The SARRP output is calibrated according to the vendor standards and TG-61 protocol utilizing an ADCL calibrated ion chamber and electrometer at 2 cm depth of solid water. A cross calibration is performed by replacing the ion chamber with five OSLDs at the 2 cm depth. The OSLDs are irradiated to 500 cGy with 220 keV at 13 mA (78s delivery time) with a coppermore » filter for an uncollimated 17×17 cm{sup 2} aperture. Instead of the absolute dose, the total amount of raw counts are collected from the OSLD reader and used for analysis. This constancy procedure was performed two more times over the course of three weeks with two OLSDs for validity. Results: The average reading for all OSLDs is 494939 with a 1-sigma standard deviation of the 5.8%. With an acceptable dose output range of ±10%, the OSLD readings have a counts range of [445445, 544433]. Conclusion: This method of using nanoDot™ OSLDs to perform output constancy checks for the SARRP ensures the output of the device is within 10% from the time of calibration and is convenient as well as time efficient. Because this, the frequency of output checks can be increased, which can improve the output stability for research with this device. The output trend of the SARRP will continue to be monitored in the future to establish a timeline for constancy checks and recalibration.« less

Pollinator visitation in populations of tristylous Eichhornia paniculata in northeastern Brazil.

PubMed

Husband, Brian C; Barrett, Spencer C H

1992-03-01

The frequencies of floral morphs in populations of tristylous Eichhornia paniculata often deviate from the theoretical expectation of equality. This variation is associated with the breakdown of tristyly and the evolution of self-fertilization. Differences in morph frequencies could result from selection pressures due to variable levels of insect visitation to populations and contrasting foraging behavior among the floral morphs. We estimated pollinator densities in 16 populations and quantified visitation sequences to morphs in five populations of E. paniculata in northeastern Brazil. Foraging behavior among floral morphs was measured as the frequency of visits to morphs relative to their frequency in the population (preference) and number of flights between inflorescences of the same versus different morphs (constancy). Pollinator density (number/m 2 /minute) was not correlated with population size, plant density or morph diversity. Pollinator densities varied most among populations of less than 200 plants. Whether pollinators discriminated among the morphs, depended on whether they primarily collected nectar or pollen. In four populations, nectar-feeding bees (Ancyloscelis and Florilegus spp.) and butterflies showed no consistent preference or constancy among the morphs. In contrast, pollen-collecting bees (Trigona sp.) visited a lower proportion of longstyled inflorescences than expected and tended to visit more mid-and short-styled inflorescences in succession, once they were encountered. Pollinator constancy for morphs did not result from differences in inflorescence production or spatial patchiness among the morphs. Although non-random pollinator visitation to morphs in heterostylous populations could potentially affect mating and hence morph frequencies, the observed visitation patterns in this study do not provide evidence that pollinators play a major role in influencing floral morph frequencies.

Covalent immobilization of metal–organic frameworks onto the surface of nylon—a new approach to the functionalization and coloration of textiles

PubMed Central

Yu, Ming; Li, Wanxin; Wang, Ziqiang; Zhang, Bowu; Ma, Hongjuan; Li, Linfan; Li, Jingye

2016-01-01

The prevention of refractory organic pollution caused by conventional dyeing and the development of new fabrics with various functions are two issues to be solved urgently in the field of textile fabrication. Here, we report a new environmentally friendly route for the simultaneous coloration and functionalization of textiles by the covalent immobilization of a metal–organic framework, Cr-based MIL-101(Cr), onto the surfaces of nylon fabrics by co-graft polymerization with 2-hydroxyethyl acrylate initiated by γ-ray irradiation. The Cr(III) clusters color the nylon fabric, and the color intensity varies with the MIL-101 content, providing a “green” textile coloration method that is different from conventional dyeing processes. An X-ray diffraction (XRD) analysis shows that the nanoporous structure of the original MIL-101 particles is retained during radiation-induced graft polymerization. Numerous nanopores are introduced onto the surface of the nylon fabric, which demonstrated better sustained-release-of-aroma performance versus pristine nylon fabric in tests. The modified fabrics exhibit laundering durability, with MIL-101 nanoparticles intact on the nylon surface after 30 h of dry cleaning. PMID:26948405

A Müllerian mimicry ring in Appalachian millipedes.

PubMed

Marek, Paul E; Bond, Jason E

2009-06-16

Few biological phenomena provide such an elegant and straightforward example of evolution by natural selection as color mimicry among unrelated organisms. By mimicking the appearance of a heavily defended aposematic species, members of a second species gain protection from predators and, potentially, enhanced fitness. Mimicking a preexisting warning advertisement is economical because a potentially costly novel one can be avoided; simultaneously, the addition of more aposematic individuals enhances the overall warning effect. The better-known mimetic systems comprise tropical taxa, but here, we show a remarkable example of color mimicry in 7 species of blind, cyanide-generating millipedes endemic to the Appalachian Mountains of temperate North America. Because these millipedes lack eyes, there is no sexual selection or intraspecific signaling for coloration, providing an ideal system for mimicry studies. We document a Müllerian symbiosis where unrelated species vary in color and pattern over geographical space but appear identical where they co-occur. By using spectral color data, estimations of evolutionary history, and detailed field observations of species abundance, we test 4 predictions of Müllerian mimicry theory and begin to unravel the story of an elaborate mimetic diversification in the forests of Appalachia.

Color image analysis of contaminants and bacteria transport in porous media

NASA Astrophysics Data System (ADS)

Rashidi, Mehdi; Dehmeshki, Jamshid; Daemi, Mohammad F.; Cole, Larry; Dickenson, Eric

1997-10-01

Transport of contaminants and bacteria in aqueous heterogeneous saturated porous systems have been studied experimentally using a novel fluorescent microscopic imaging technique. The approach involves color visualization and quantification of bacterium and contaminant distributions within a transparent porous column. By introducing stained bacteria and an organic dye as a contaminant into the column and illuminating the porous regions with a planar sheet of laser beam, contaminant and bacterial transport processes through the porous medium can be observed and measured microscopically. A computer controlled color CCD camera is used to record the fluorescent images as a function of time. These images are recorded by a frame accurate high resolution VCR and are then analyzed using a color image analysis code written in our laboratories. The color images are digitized this way and simultaneous concentration and velocity distributions of both contaminant and bacterium are evaluated as a function of time and pore characteristics. The approach provides a unique dynamic probe to observe these transport processes microscopically. These results are extremely valuable in in-situ bioremediation problems since microscopic particle-contaminant- bacterium interactions are the key to understanding and optimization of these processes.

A Müllerian mimicry ring in Appalachian millipedes

PubMed Central

Marek, Paul E.; Bond, Jason E.

2009-01-01

Few biological phenomena provide such an elegant and straightforward example of evolution by natural selection as color mimicry among unrelated organisms. By mimicking the appearance of a heavily defended aposematic species, members of a second species gain protection from predators and, potentially, enhanced fitness. Mimicking a preexisting warning advertisement is economical because a potentially costly novel one can be avoided; simultaneously, the addition of more aposematic individuals enhances the overall warning effect. The better-known mimetic systems comprise tropical taxa, but here, we show a remarkable example of color mimicry in 7 species of blind, cyanide-generating millipedes endemic to the Appalachian Mountains of temperate North America. Because these millipedes lack eyes, there is no sexual selection or intraspecific signaling for coloration, providing an ideal system for mimicry studies. We document a Müllerian symbiosis where unrelated species vary in color and pattern over geographical space but appear identical where they co-occur. By using spectral color data, estimations of evolutionary history, and detailed field observations of species abundance, we test 4 predictions of Müllerian mimicry theory and begin to unravel the story of an elaborate mimetic diversification in the forests of Appalachia. PMID:19487663

Rapid method for quantification of seven synthetic pigments in colored Chinese steamed buns using UFLC-MS/MS without SPE.

PubMed

Gao, He-Gang; Gong, Wen-Jie; Zhao, Yong-Gang

2015-01-01

Synthetic pigments are still used instead of natural pigments in many foods and their residues in food could be an important risk to human health. A simple and rapid analytical method combining the low-cost extraction protocol with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) was developed for the simultaneous determination of seven synthetic pigments used in colored Chinese steamed buns. For the first time, ethanol/ammonia solution/water (7:2:1, v/v/v) was used as extraction solution for the synthetic pigments in colored Chinese steamed buns. The results showed that the property of the extraction solution used in this method was more effective than critic acid solution, which is used in the polyamide adsorption method. The limits of quantification for the seven synthetic pigments ranged from 0.15 to 0.50 μg/kg. The present method was successfully applied to samples of colored Chinese steamed buns for food-safety risk monitoring in Zhejiang Province, China. The results found sunset yellow pigment in six out of 300 colored Chinese steamed buns (from 0.50 to 32.6 μg/kg).

An ultra-small, multi-point, and multi-color photo-detection system with high sensitivity and high dynamic range.

PubMed

Anazawa, Takashi; Yamazaki, Motohiro

2017-12-05

Although multi-point, multi-color fluorescence-detection systems are widely used in various sciences, they would find wider applications if they are miniaturized. Accordingly, an ultra-small, four-emission-point and four-color fluorescence-detection system was developed. Its size (space between emission points and a detection plane) is 15 × 10 × 12 mm, which is three-orders-of-magnitude smaller than that of a conventional system. Fluorescence from four emission points with an interval of 1 mm on the same plane was respectively collimated by four lenses and split into four color fluxes by four dichroic mirrors. Then, a total of sixteen parallel color fluxes were directly input into an image sensor and simultaneously detected. The emission-point plane and the detection plane (the image-sensor surface) were parallel and separated by a distance of only 12 mm. The developed system was applied to four-capillary array electrophoresis and successfully achieved Sanger DNA sequencing. Moreover, compared with a conventional system, the developed system had equivalent high fluorescence-detection sensitivity (lower detection limit of 17 pM dROX) and 1.6-orders-of-magnitude higher dynamic range (4.3 orders of magnitude).

Simple approach to three-color two-photon microscopy by a fiber-optic wavelength convertor.

PubMed

Li, Kuen-Che; Huang, Lynn L H; Liang, Jhih-Hao; Chan, Ming-Che

2016-11-01

A simple approach to multi-color two-photon microscopy of the red, green, and blue fluorescent indicators was reported based on an ultra-compact 1.03-μm femtosecond laser and a nonlinear fiber. Inside the nonlinear fiber, the 1.03-μm laser pulses were simultaneously blue-shifted to 0.6~0.8 μm and red-shifted to 1.2~1.4 μm region by the Cherenkov radiation and fiber Raman gain effects. The wavelength-shifted 0.6~0.8 μm and 1.2~1.4 μm radiations were co-propagated with the residual non-converted 1.03-μm pulses inside the same nonlinear fiber to form a fiber-output three-color femtosecond source. The application of the multi-wavelength sources on multi-color two-photon fluorescence microscopy were also demonstrated. Overall, due to simple system configuration, convenient wavelength conversion, easy wavelength tunability within the entire 0.7~1.35 μm bio-penetration window and less requirement for high power and bulky light sources, the simple approach to multi-color two-photon microscopy could be widely applicable as an easily implemented and excellent research tool for future biomedical and possibly even clinical applications.

Color appearance in stereoscopy

NASA Astrophysics Data System (ADS)

Gadia, Davide; Rizzi, Alessandro; Bonanomi, Cristian; Marini, Daniele; Galmonte, Alessandra; Agostini, Tiziano

2011-03-01

The relationship between color and lightness appearance and the perception of depth has been studied since a while in the field of perceptual psychology and psycho-physiology. It has been found that depth perception affects the final object color and lightness appearance. In the stereoscopy research field, many studies have been proposed on human physiological effects, considering e.g. geometry, motion sickness, etc., but few has been done considering lightness and color information. Goal of this paper is to realize some preliminar experiments in Virtual Reality in order to determine the effects of depth perception on object color and lightness appearance. We have created a virtual test scene with a simple 3D simultaneous contrast configuration. We have created three different versions of this scene, each with different choices of relative positions and apparent size of the objects. We have collected the perceptual responses of several users after the observation of the test scene in the Virtual Theater of the University of Milan, a VR immersive installation characterized by a semi-cylindrical screen that covers 120° of horizontal field of view from an observation distance of 3.5 m. We present a description of the experiments setup and procedure, and we discuss the obtained results.

Proceedings: Conference on Compensatory/Remedial Education.

ERIC Educational Resources Information Center

Fea, Henry R., Ed.; And Others

This document presents the papers and discussions from the Conference on Compensatory/Remedial Education. The contents include: "Institutional Programs for the Low Achievers" by Joan G. Roloff; "Communication in Compensatory Education" by Henry R. Fea; "Seminar: Special Programs for Minorities" by Constance Acholonu; "Seminar: Special Programs for…

Preferred Retirement Timing and Retirement Satisfaction in Women.

ERIC Educational Resources Information Center

Szinovacz, Maximiliane

1987-01-01

Explored retirement conditions affecting women's preferred retirement timing and retirement satisfaction in 115 women retirees. Revealed that women's life goals, sex role constancy over the years, the economic impact of retirement, and respondents' control over determination of retirement timing were relevant issues. (Author/KS)

Integrating Curriculum in a Total Quality School.

ERIC Educational Resources Information Center

Jenkins, Kenneth D.; Jenkins, Doris M.

1998-01-01

Examined the changes implemented by teachers at Brown Barge Middle School, in Pensacola, Florida, to improve curriculum. Notes the teachers' use of total quality education principles and describes six propositions of change: achieving constancy of purpose, building quality, continuous improvement, student-centered approach, using data, and…

Applying Continuous Quality Improvement Principles in Secondary School Vocational Education, with Emphasis on Special Populations.

ERIC Educational Resources Information Center

McLean, Gary N.

1993-01-01

Principles of quality management applicable to education for secondary special populations include process orientation, cascading, top commitment, vertical/horizontal communication, continuous improvement, shared vision, primacy of customers, investment in people, constancy of purpose, and shared goal setting. (JOW)

Alternatives for discounting in the analysis of noninferiority trials.

PubMed

Snapinn, Steven M

2004-05-01

Determining the efficacy of an experimental therapy relative to placebo on the basis of an active-control noninferiority trial requires reference to historical placebo-controlled trials. The validity of the resulting comparison depends on two key assumptions: assay sensitivity and constancy. Since the truth of these assumptions cannot be verified, it seems logical to raise the standard of evidence required to declare efficacy; this concept is referred to as discounting. It is not often recognized that two common design and analysis approaches, setting a noninferiority margin and requiring preservation of a fraction of the standard therapy's effect, are forms of discounting. The noninferiority margin is a particularly poor approach, since its degree of discounting depends on an irrelevant factor. Preservation of effect is more reasonable, but it addresses only the constancy assumption, not the issue of assay sensitivity. Gaining consensus on the most appropriate approach to the design and analysis of noninferiority trials will require a common understanding of the concept of discounting.

Calibration of the Galactic Cosmic Ray Flux

NASA Technical Reports Server (NTRS)

Mathew, K. J.; Marti, K.

2004-01-01

We report first Xe data on the cross-calibration of I-129-Xe-129(sub n) ages with conventional CRE ages, a method which is expected to provide information on the long-term constancy of the galactic cosmic ray (GCR) flux. We studied isotopic signatures of Xe released in stepwise heating, decomposition and melting of troilites in the Cape York iron meteorite to identify isotopic shifts in Xe-129 and Xe-131 due to neutron capture in Te-128 and Te-130. We also resolve components due to extinct 129I, spallation and fission Xe. There has recently been much speculation on the constancy of GCR over long time scales, as may be inferred from iron meteorites. If GCRs originate from supernova events, this provides the basis for postulating increased fluxes at locations with higher than average densities of supernovae, specifically in OB-associations. The solar system at present appears to be inside a local bubble between spiral arms and may experience an increased GCR flux.

Long-term development of hypolimnetic oxygen depletion rates in the large Lake Constance.

PubMed

Rhodes, Justin; Hetzenauer, Harald; Frassl, Marieke A; Rothhaupt, Karl-Otto; Rinke, Karsten

2017-09-01

This study investigates over 30 years of dissolved oxygen dynamics in the deep interior of Lake Constance (max. depth: 250 m). This lake supplies approximately four million people with drinking water and has undergone strong re-oligotrophication over the past decades. We calculated depth-specific annual oxygen depletion rates (ODRs) during the period of stratification and found that 50% of the observed variability in ODR was already explained by a simple separation into a sediment- and volume-related oxygen consumption. Adding a linear factor for water depth further improved the model indicating that oxygen depletion increased substantially along the depth. Two other factors turned out to significantly influence ODR: total phosphorus as a proxy for the lake's trophic state and mean oxygen concentration in the respective depth layer. Our analysis points to the importance of nutrient reductions as effective management measures to improve and protect the oxygen status of such large and deep lakes.

Gender constancy and the effects of sex-typed televised toy commercials.

PubMed

Ruble, D N; Balaban, T; Cooper, J

1981-06-01

The present study represented a cognitive-developmental analysis of the effects of televised, sex-stereotypic information on children's behavior and attitudes toward toy play. The subjects were 50 male and 50 female 4-6-year-olds divided into high and low gender-constancy levels. As the children watched a cartoon, they either saw a commercial of a gender-neutral toy that showed 2 boys or 2 girls playing with the toy, or they saw no commercial (control). As predicted, only the high gender-constant children were differentially affected by the sex-role information in the different commercial conditions. Children at this stage who saw opposite-sex children playing with the toy avoided spending time with the toy and stated verbally that the toy was more appropriate for an opposite-sex sibling, relative to children in the 2 other conditions. The results are discussed in terms of their implications for theories of sex-role development and in terms of the role that television may play in maintaining sex stereotypes and sex-typed behavior.

[Comparison of genetic diversity (RAPD) of ex situ collections and natural populations of Naufraga balearica Constance & Cannon].

PubMed

Fridlender, A; Boisselier-Dubayle, M C

2000-04-01

Naufraga balearica Constance & Cannon (Hydrocotyloideae) cultivated in the Botanical Gardens of Lyon, Brest and Porquerolles stem from two or three shoots collected in Corsica in 1981. The genetic diversity of these plants was evaluated using RAPD markers (random amplified polymorphic DNA). It was compared with the diversity found in individuals collected from five natural sites in Majorca. Only a few patterns were present in the collections derived from the Corsican shoots. The plants kept in the Botanical Gardens appeared to be of clonal origin: most individuals (81%) showed a 'dominant pattern'. In contrast, nearly all individuals sampled in the natural populations of the Balearic Islands exhibited a unique pattern. The five populations appeared genetically distinct; the individuals probably resulted from cross-fertilizations. The cultivated Corsican plants from Lyon, Brest and Porquerolles appeared genetically closely related to the individuals sampled in the population of Cala San Vicente in Majorca. The spontaneity of this paleoendemic in Corsica was discussed.

Bipedicled Preexpanded Forehead Flaps for Simultaneous Reconstruction of Total Nasal and Upper Lip Subunits: A Novel Approach to Complex Facial Resurfacing.

PubMed

Su, Weijie; Min, Peiru; Sadigh, Parviz; Grassetti, Luca; Lazzeri, Davide; Munnee, Krishna; Pu, Zheming; Zhang, Yixin

2016-06-01

Background Reconstruction of the central facial subunits is a complex and challenging task. In cases in which both the nasal and upper lip subunits are involved, a technique that can reconstruct both aesthetic units with tissue of similar color and texture from a single donor site will be ideal. In this article we present our experience with the bipedicled preexpanded forehead flap for simultaneous nasal and upper lip resurfacing. Patients and Methods Between January 2012 and January 2015 we used this technique in the simultaneous reconstruction of total nasal and upper lip subunits in five patients. All cases were for burns scar resurfacing. Results Good aesthetic results were achieved in each of our five cases to date and no complications were encountered. All donor sites closed primarily with aesthetically pleasing well-concealed linear scars. In all cases small modifications such as philtral shaping and further flap thinning were performed under local anesthesia between 6 and 12 months postoperatively Conclusion The preexpanded forehead flap provides an unparalleled color and texture match when it comes to facial resurfacing. When both total nasal and upper lip resurfacings are required, it is possible to achieve this in a single sitting from a single donor site by using a bipedicled preexpanded forehead flap. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Using counts to simultaneously estimate abundance and detection probabilities in a salamander community

USGS Publications Warehouse

Dodd, C.K.; Dorazio, R.M.

2004-01-01

A critical variable in both ecological and conservation field studies is determining how many individuals of a species are present within a defined sampling area. Labor intensive techniques such as capture-mark-recapture and removal sampling may provide estimates of abundance, but there are many logistical constraints to their widespread application. Many studies on terrestrial and aquatic salamanders use counts as an index of abundance, assuming that detection remains constant while sampling. If this constancy is violated, determination of detection probabilities is critical to the accurate estimation of abundance. Recently, a model was developed that provides a statistical approach that allows abundance and detection to be estimated simultaneously from spatially and temporally replicated counts. We adapted this model to estimate these parameters for salamanders sampled over a six vear period in area-constrained plots in Great Smoky Mountains National Park. Estimates of salamander abundance varied among years, but annual changes in abundance did not vary uniformly among species. Except for one species, abundance estimates were not correlated with site covariates (elevation/soil and water pH, conductivity, air and water temperature). The uncertainty in the estimates was so large as to make correlations ineffectual in predicting which covariates might influence abundance. Detection probabilities also varied among species and sometimes among years for the six species examined. We found such a high degree of variation in our counts and in estimates of detection among species, sites, and years as to cast doubt upon the appropriateness of using count data to monitor population trends using a small number of area-constrained survey plots. Still, the model provided reasonable estimates of abundance that could make it useful in estimating population size from count surveys.

Visual Speech-Training Aid for the Deaf

NASA Technical Reports Server (NTRS)

Miller, Robert J.

1987-01-01

Teaching deaf to speak aided by electronic system provides striking colored, pictorial representation of sound; energy at different frequencies as function of time. Other modalities, such as nasality, intra-oral pressure, and lip-muscle contraction, pictorialized simultaneously. Use of standard components, including personal microcomputer, helps reduce cost below prior voice-training systems. Speech-training system, microphone output separated by filters into narrow frequency bands, changed into digital signals, formatted by computer, and displayed on television screen. Output from other sensors displayed simultaneously or screen split to allow sound produced by student to be compared with that of teacher.

Accuracy, resolution, and cost comparisons between small format and mapping cameras for environmental mapping

NASA Technical Reports Server (NTRS)

Clegg, R. H.; Scherz, J. P.

1975-01-01

Successful aerial photography depends on aerial cameras providing acceptable photographs within cost restrictions of the job. For topographic mapping where ultimate accuracy is required only large format mapping cameras will suffice. For mapping environmental patterns of vegetation, soils, or water pollution, 9-inch cameras often exceed accuracy and cost requirements, and small formats may be better. In choosing the best camera for environmental mapping, relative capabilities and costs must be understood. This study compares resolution, photo interpretation potential, metric accuracy, and cost of 9-inch, 70mm, and 35mm cameras for obtaining simultaneous color and color infrared photography for environmental mapping purposes.

Single-shot optical sectioning using two-color probes in HiLo fluorescence microscopy.

PubMed

Muro, Eleonora; Vermeulen, Pierre; Ioannou, Andriani; Skourides, Paris; Dubertret, Benoit; Fragola, Alexandra; Loriette, Vincent

2011-06-08

We describe a wide-field fluorescence microscope setup which combines HiLo microscopy technique with the use of a two-color fluorescent probe. It allows one-shot fluorescence optical sectioning of thick biological moving sample which is illuminated simultaneously with a flat and a structured pattern at two different wavelengths. Both homogenous and structured fluorescence images are spectrally separated at detection and combined similarly with the HiLo microscopy technique. We present optically sectioned full-field images of Xenopus laevis embryos acquired at 25 images/s frame rate. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Efficient image projection by Fourier electroholography.

PubMed

Makowski, Michał; Ducin, Izabela; Kakarenko, Karol; Kolodziejczyk, Andrzej; Siemion, Agnieszka; Siemion, Andrzej; Suszek, Jaroslaw; Sypek, Maciej; Wojnowski, Dariusz

2011-08-15

An improved efficient projection of color images is presented. It uses a phase spatial light modulator with three iteratively optimized Fourier holograms displayed simultaneously--each for one primary color. This spatial division instead of time division provides stable images. A pixelated structure of the modulator and fluctuations of liquid crystal molecules cause a zeroth-order peak, eliminated by additional wavelength-dependent phase factors shifting it before the image plane, where it is blocked with a matched filter. Speckles are suppressed by time integration of variable speckle patterns generated by additional randomizations of an initial phase and minor changes of the signal. © 2011 Optical Society of America

On Seeing Reddish Green and Yellowish Blue.

ERIC Educational Resources Information Center

Crane, Hewitt D.; Piantanida, Thomas P.

1983-01-01

Stabilization of the retinal image of the boundary between a pair of red/green or yellow/blue stripes, but not their outer edges, results in the entire region being perceived simultaneously as both red/green or yellow/blue. This suggests that the percepts of reddish-green/yellowish-blue apparently are possible in corticocortical color vision…

Film Language: A Student-Made Dictionary.

ERIC Educational Resources Information Center

Poteet, G. Howard

1967-01-01

The failure of verbal descriptions to convey an understanding of film terminology led to a student production of a 20-minute color film that defines various film methods by illustrating them. A technique is shown on the screen and simultaneous soundtrack narration explains how this technique can be used. When the narration lasts longer than the…

An inexpensive programmable illumination microscope with active feedback.

PubMed

Tompkins, Nathan; Fraden, Seth

2016-02-01

We have developed a programmable illumination system capable of tracking and illuminating numerous objects simultaneously using only low-cost and reused optical components. The active feedback control software allows for a closed-loop system that tracks and perturbs objects of interest automatically. Our system uses a static stage where the objects of interest are tracked computationally as they move across the field of view allowing for a large number of simultaneous experiments. An algorithmically determined illumination pattern can be applied anywhere in the field of view with simultaneous imaging and perturbation using different colors of light to enable spatially and temporally structured illumination. Our system consists of a consumer projector, camera, 35-mm camera lens, and a small number of other optical and scaffolding components. The entire apparatus can be assembled for under $4,000.

Preserving American Folk Heritage through Story and Song.

ERIC Educational Resources Information Center

Jalongo, Mary Renck

Underscoring folklore's appropriateness to multicultural classroom settings are its connection with past and present cultures, its constancy and change, and its potential for oral transmission of human values. Most importantly, folktales and songs enable children to participate in the history of universal human emotions. To effectively include…

Scaling up IT: Weighing the Options, Maintaining the Balance.

ERIC Educational Resources Information Center

Griffiths, Jose-Marie

1999-01-01

Discusses the integration of information technology into an institution of higher education, based on experiences at the University of Tennessee at Knoxville and the University of Michigan. Topics include changes in user populations; leadership; infrastructure; teamwork; organizational priorities; attitudes and expectations; and the constancy of…

Schools for Cities: Urban Strategies. NEA Series on Design.

ERIC Educational Resources Information Center

Haar, Sharon, Ed.

This monograph presents papers from the 2000 Mayors' Institute on City Design and the public forum that followed it. Essays include: "Schools for Cities: Urban Strategies" (Sharon Haar); "Reenvisioning Schools; The Mayors' Questions" (Leah Ray); "Why Johnny Can't Walk to School" (Constance E. Beaumont); "Lessons…

Effects of subjective preference of colors on attention-related occipital theta oscillations.

PubMed

Kawasaki, Masahiro; Yamaguchi, Yoko

2012-01-02

Human daily behaviors are often affected by subjective preferences. Studies have shown that physical responses are affected by unconscious preferences before conscious decision making. Accordingly, attention-related neural activities could be influenced by unconscious preferences. However, few neurological data exist on the relationship between visual attention and subjective preference. To address this issue, we focused on lateralization during visual attention and investigated the effects of subjective color preferences on visual attention-related brain activities. We recorded electroencephalograph (EEG) data during a preference judgment task that required 19 participants to choose their preferred color from 2 colors simultaneously presented to the right and left hemifields. In addition, to identify oscillatory activity during visual attention, we conducted a control experiment in which the participants focused on either the right or the left color without stating their preference. The EEG results showed enhanced theta (4-6 Hz) and decreased alpha (10-12 Hz) activities in the right and left occipital electrodes when the participants focused on the color in the opposite hemifield. Occipital theta synchronizations also increased contralaterally to the hemifield to which the preferred color was presented, whereas the alpha desynchronizations showed no lateralization. The contralateral occipital theta activity lasted longer than the ipsilateral occipital theta activity. Interestingly, theta lateralization was observed even when the preferred color was presented to the unattended side in the control experiment, revealing the strength of the preference-related theta-modulation effect irrespective of visual attention. These results indicate that subjective preferences modulate visual attention-related brain activities. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

Photometric Separation of Stellar Properties Using SDSS Filters

NASA Astrophysics Data System (ADS)

Lenz, Dawn D.; Newberg, Jo; Rosner, Robert; Richards, Gordon T.; Stoughton, Chris

1998-12-01

Using synthetic photometry of Kurucz model spectra, we explore the colors of stars as a function of temperature, metallicity, and surface gravity with Sloan Digital Sky Survey (SDSS) filters, u'g'r'i'z'. The synthetic colors show qualitative agreement with the few published observations in these filters. We find that the locus of synthetic stars is basically two-dimensional for 4500 < T < 8000 K, which precludes simultaneous color separation of the three basic stellar characteristics we consider. Colors including u' contain the most information about normal stellar properties; measurements in this filter are also important for selecting white dwarfs. We identify two different subsets of the locus in which the loci separate by either metallicity or surface gravity. For 0.5 < g' - r' < 0.8 (corresponding roughly to G stars), the locus separates by metallicity; for photometric error of a few percent, we estimate metallicity to within ~0.5 dex in this range. In the range -0.15 < g' - r' < 0.00 (corresponding roughly to A stars), the locus shows separation by surface gravity. In both cases, we show that it is advantageous to use more than two colors when determining stellar properties by color. Strategic observations in SDSS filters are required to resolve the source of a ~5% discrepancy between synthetic colors of Gunn-Stryker stars, Kurucz models, and external determinations of the metallicities and surface gravities. The synthetic star colors can be used to investigate the properties of any normal star and to construct analytic expressions for the photometric prediction of stellar properties in special cases.

Multispectral computational ghost imaging with multiplexed illumination

NASA Astrophysics Data System (ADS)

Huang, Jian; Shi, Dongfeng

2017-07-01

Computational ghost imaging has attracted wide attention from researchers in many fields over the last two decades. Multispectral imaging as one application of computational ghost imaging possesses spatial and spectral resolving abilities, and is very useful for surveying scenes and extracting detailed information. Existing multispectral imagers mostly utilize narrow band filters or dispersive optical devices to separate light of different wavelengths, and then use multiple bucket detectors or an array detector to record them separately. Here, we propose a novel multispectral ghost imaging method that uses one single bucket detector with multiplexed illumination to produce a colored image. The multiplexed illumination patterns are produced by three binary encoded matrices (corresponding to the red, green and blue colored information, respectively) and random patterns. The results of the simulation and experiment have verified that our method can be effective in recovering the colored object. Multispectral images are produced simultaneously by one single-pixel detector, which significantly reduces the amount of data acquisition.

The use of Skylab data to study the early detection of insect infestations and density and distribution of host plants

NASA Technical Reports Server (NTRS)

Hart, W. G.; Ingle, S. J.; Davis, M. R.

1975-01-01

The detection of insect infestations and the density and distribution of host plants were studied using Skylab data, aerial photography and ground truth simultaneously. Additional ground truth and aerial photography were acquired between Skylab passes. Three test areas were selected: area 1, of high density citrus, was located northwest of Mission, Texas; area 2, 20 miles north of Weslaco, Texas, irrigated pastures and brush-covered land; area 3 covered the entire Lower Rio Grande Valley and adjacent areas of Mexico. A color composite picture of S-190A data showed patterns of vegetation on both sides of the Rio Grande River clearly delineating the possible avenues of entry of pest insects from Mexico into the United States or from the United States into Mexico. Vegetation that could be identified with conventional color and color IR film included: citrus, brush, sugarcane, alfalfa, irrigated and unimproved pastures.

Synthesis of nano silver on cellulosic denim fabric producing yellow colored garment with antibacterial properties.

PubMed

Maryan, Ali Sadeghian; Montazer, Majid; Harifi, Tina

2015-01-22

In this study, an aged-look denim fabric with antibacterial property was prepared in one single step process. For this purpose, the simultaneous antibacterial finishing and discoloration of denim fabric was carried out through reduction of indigo dye and silver nitrate by glucose in alkaline media using a conventional garment washing machine. The uniform distribution of silver nanoparticles on the fiber surface was confirmed by scanning electron microscope and energy dispersive X-ray spectroscopy. The treated fabrics were also characterized by X-ray diffraction (XRD) and Raman spectroscopy. Due to the color changes during the process, the color coordinates of the treated samples were also measured. Findings suggest the potential of the proposed method in producing old-look denim fabric with desirable yellow appearance and reasonable antibacterial activity against Staphylococcus aureus and Escherichia coli with low toxicity for human. Copyright © 2014 Elsevier Ltd. All rights reserved.

Color vision in the giant panda (Ailuropoda melanoleuca).

PubMed

Kelling, Angela S; Snyder, Rebecca J; Marr, M Jackson; Bloomsmith, Mollie A; Gardner, Wendy; Maple, Terry L

2006-05-01

Hue discrimination abilities of giant pandas were tested, controlling for brightness. Subjects were 2 adult giant pandas (1 male and 1 female). A simultaneous discrimination procedure without correction was used. In five tasks, white, black, and five saturations each of green, blue, and red served as positive stimuli that were paired with one or two comparison stimuli consisting of 16 saturations of gray. To demonstrate discrimination, the subjects were required to choose the positive stimulus in 16 of 20 trials (80% correct) for three consecutivesessions. Both subjects reached criterion forgreen and red. The female subject also reached criterion for blue. The male was not tested for blue. This study is a systematic replication of Bacon and Burghardt's (1976) color discrimination experiment on black bears. The results suggest that color vision in the giant panda is comparable to that of black bears and other carnivores that are not strictly nocturnal.

Two-color field enhancement at an STM junction for spatiotemporally resolved photoemission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meng, Xiang; Jin, Wencan; Yang, Hao

Here, we report measurements and numerical simulations of ultrafast laser-excited carrier flow across a scanning tunneling microscope (STM) junction. The current from a nanoscopic tungsten tip across a ~1 nm vacuum gap to a silver surface is driven by a two-color excitation scheme that uses an optical delay-modulation technique to extract the two-color signal from background contributions. The role of optical field enhancements in driving the current is investigated using density functional theory and full three-dimensional finite-difference time-domain computations. We find that simulated field-enhanced two-photon photoemission (2PPE) currents are in excellent agreement with the observed exponential decay of the two-colormore » photoexcited current with increasing tip–surface separation, as well as its optical-delay dependence. The results suggest an approach to 2PPE with simultaneous subpicosecond temporal and nanometer spatial resolution.« less

Photometric stereo endoscopy.

PubMed

Parot, Vicente; Lim, Daryl; González, Germán; Traverso, Giovanni; Nishioka, Norman S; Vakoc, Benjamin J; Durr, Nicholas J

2013-07-01

While color video endoscopy has enabled wide-field examination of the gastrointestinal tract, it often misses or incorrectly classifies lesions. Many of these missed lesions exhibit characteristic three-dimensional surface topographies. An endoscopic system that adds topographical measurements to conventional color imagery could therefore increase lesion detection and improve classification accuracy. We introduce photometric stereo endoscopy (PSE), a technique which allows high spatial frequency components of surface topography to be acquired simultaneously with conventional two-dimensional color imagery. We implement this technique in an endoscopic form factor and demonstrate that it can acquire the topography of small features with complex geometries and heterogeneous optical properties. PSE imaging of ex vivo human gastrointestinal tissue shows that surface topography measurements enable differentiation of abnormal shapes from surrounding normal tissue. Together, these results confirm that the topographical measurements can be obtained with relatively simple hardware in an endoscopic form factor, and suggest the potential of PSE to improve lesion detection and classification in gastrointestinal imaging.

Two-color field enhancement at an STM junction for spatiotemporally resolved photoemission

DOE PAGES

Meng, Xiang; Jin, Wencan; Yang, Hao; ...

2017-06-30

Here, we report measurements and numerical simulations of ultrafast laser-excited carrier flow across a scanning tunneling microscope (STM) junction. The current from a nanoscopic tungsten tip across a ~1 nm vacuum gap to a silver surface is driven by a two-color excitation scheme that uses an optical delay-modulation technique to extract the two-color signal from background contributions. The role of optical field enhancements in driving the current is investigated using density functional theory and full three-dimensional finite-difference time-domain computations. We find that simulated field-enhanced two-photon photoemission (2PPE) currents are in excellent agreement with the observed exponential decay of the two-colormore » photoexcited current with increasing tip–surface separation, as well as its optical-delay dependence. The results suggest an approach to 2PPE with simultaneous subpicosecond temporal and nanometer spatial resolution.« less

Dual-Color Click Beetle Luciferase Heteroprotein Fragment Complementation Assays

PubMed Central

Villalobos, Victor; Naik, Snehal; Bruinsma, Monique; Dothager, Robin S.; Pan, Mei-Hsiu; Samrakandi, Mustapha; Moss, Britney; Elhammali, Adnan; Piwnica-Worms, David

2010-01-01

Summary Understanding the functional complexity of protein interactions requires mapping biomolecular complexes within the cellular environment over biologically-relevant time scales. Herein we describe a novel set of reversible, multicolored heteroprotein complementation fragments based on various firefly and click beetle luciferases that utilize the same substrate, D-luciferin. Luciferase heteroprotein fragment complementation systems enabled dual-color quantification of two discreet pairs of interacting proteins simultaneously or two distinct proteins interacting with a third shared protein in live cells. Using real-time analysis of click beetle green and click beetle red luciferase heteroprotein fragment complementation applied to β-TrCP, an E3-ligase common to the regulation of both β-catenin and IκBα, GSK3β was identified as a novel candidate kinase regulating IκBα processing. These dual-color protein interaction switches may enable directed dynamic analysis of a variety of protein interactions in living cells. PMID:20851351

Digital methods of recording color television images on film tape

NASA Astrophysics Data System (ADS)

Krivitskaya, R. Y.; Semenov, V. M.

1985-04-01

Three methods are now available for recording color television images on film tape, directly or after appropriate finish of signal processing. Conventional recording of images from the screens of three kinescopes with synthetic crystal face plates is still most effective for high fidelity. This method was improved by digital preprocessing of brightness color-difference signal. Frame-by-frame storage of these signals in the memory in digital form is followed by gamma and aperture correction and electronic correction of crossover distortions in the color layers of the film with fixing in accordance with specific emulsion procedures. The newer method of recording color television images with line arrays of light-emitting diodes involves dichromic superposing mirrors and a movable scanning mirror. This method allows the use of standard movie cameras, simplifies interlacing-to-linewise conversion and the mechanical equipment, and lengthens exposure time while it shortens recording time. The latest image transform method requires an audio-video recorder, a memory disk, a digital computer, and a decoder. The 9-step procedure includes preprocessing the total color television signal with reduction of noise level and time errors, followed by frame frequency conversion and setting the number of lines. The total signal is then resolved into its brightness and color-difference components and phase errors and image blurring are also reduced. After extraction of R,G,B signals and colorimetric matching of TV camera and film tape, the simultaneous R,B, B signals are converted from interlacing to sequential triades of color-quotient frames with linewise scanning at triple frequency. Color-quotient signals are recorded with an electron beam on a smoothly moving black-and-white film tape under vacuum. While digital techniques improve the signal quality and simplify the control of processes, not requiring stabilization of circuits, image processing is still analog.

In vivo, two-color multiphoton microscopy using a femtosecond diamond Raman laser

NASA Astrophysics Data System (ADS)

Jarrett, Jeremy W.; Perillo, Evan P.; Hassan, Ahmed; Miller, David R.; Dunn, Andrew K.

2018-02-01

Multiphoton microscopy is an essential tool for detailed study of neurovascular structure and function. Wavelength mixing of synchronized laser sources—two-color multiphoton microscopy—increases the spectral window of excitable fluorophores without the need for wavelength tuning. However, implementation of two-color microscopy requires a dual output laser source, which is typically costly and complicated. We have developed a relatively simple and low-cost diamond Raman laser pumped with a ytterbium fiber amplifier. The dual output system generates excitation light at both 1060 nm (pump wavelength) and 1250 nm (first Stokes emission of diamond laser) which, when temporally and spatially overlapped, yield an effective two-color excitation wavelength of 1160 nm. This source provides an almost complete coverage of fluorophores excitable within the range of 1000-1300 nm. When compared with 1060 nm excitation, twocolor excitation at 1160 nm offers a 90% increase in signal for many far-red emitting fluorescent proteins (e.g. tdKatushka2). We demonstrate multicolor imaging of tdKatushka2 and Hoechst 33342 via simultaneous two-color twophoton, and two-color three-photon microscopy in engineered 3-D multicellular spheroids. Additionally, we show that this laser system is capable of in vivo imaging in mouse cortex to nearly 1 mm in depth with two-color excitation. This system can also be used to excite genetically encoded calcium indicators (e.g. RCaMP and GCaMP), which will be paramount in studying neuronal activity.

Color Retinal Image Enhancement Based on Luminosity and Contrast Adjustment.

PubMed

Zhou, Mei; Jin, Kai; Wang, Shaoze; Ye, Juan; Qian, Dahong

2018-03-01

Many common eye diseases and cardiovascular diseases can be diagnosed through retinal imaging. However, due to uneven illumination, image blurring, and low contrast, retinal images with poor quality are not useful for diagnosis, especially in automated image analyzing systems. Here, we propose a new image enhancement method to improve color retinal image luminosity and contrast. A luminance gain matrix, which is obtained by gamma correction of the value channel in the HSV (hue, saturation, and value) color space, is used to enhance the R, G, and B (red, green and blue) channels, respectively. Contrast is then enhanced in the luminosity channel of L * a * b * color space by CLAHE (contrast-limited adaptive histogram equalization). Image enhancement by the proposed method is compared to other methods by evaluating quality scores of the enhanced images. The performance of the method is mainly validated on a dataset of 961 poor-quality retinal images. Quality assessment (range 0-1) of image enhancement of this poor dataset indicated that our method improved color retinal image quality from an average of 0.0404 (standard deviation 0.0291) up to an average of 0.4565 (standard deviation 0.1000). The proposed method is shown to achieve superior image enhancement compared to contrast enhancement in other color spaces or by other related methods, while simultaneously preserving image naturalness. This method of color retinal image enhancement may be employed to assist ophthalmologists in more efficient screening of retinal diseases and in development of improved automated image analysis for clinical diagnosis.

Single-tube, non-isotopic, multiplex PCR/OLA assay and sequence-coded separation for simultaneous screening of 31 cystic fibrosis mutations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brinson, E.C.; Adriano, T.; Bloch, W.

1994-09-01

We have developed a rapid, single-tube, non-isotopic assay that screens a patient sample for the presence of 31 cystic fibrosis (CF) mutations. This assay can identify these mutations in a single reaction tube and a single electrophoresis run. Sample preparation is a simple, boil-and-go procedure, completed in less than an hour. The assay is composed of a 15-plex PCR, followed by a 61-plex oligonucleotide ligation assay (OLA), and incorporates a novel detection scheme, Sequence Coded Separation. Initially, the multiplex PCR amplifies 15 relevant segments of the CFTR gene, simultaneously. These PCR amplicons serve as templates for the multiplex OLA, whichmore » detects the normal or mutant allele at all loci, simultaneously. Each polymorphic site is interrogated by three oligonucleotide probes, a common probe and two allele-specific probes. Each common probe is tagged with a fluorescent dye, and the competing normal and mutant allelic probes incorporate different, non-nucleotide, mobility modifiers. These modifiers are composed of hexaethylene oxide (HEO) units, incorporated as HEO phosphoramidite monomers during automated DNA synthesis. The OLA is based on both probe hybridization and the ability of DNA ligase to discriminate single base mismatches at the junction between paired probes. Each single tube assay is electrophoresed in a single gel lane of a 4-color fluorescent DNA sequencer (Applied Biosystems, Model 373A). Each of the ligation products is identified by its unique combination of electrophoretic mobility and one of three colors. The fourth color is reserved for the in-lane size standard, used by GENESCAN{sup TM} software (Applied Biosystems) to size the OLA electrophoresis products. The Genotyper{sub TM} software (Applied Biosystems) decodes these Sequence-Coded-Separation data to create a patient summary report for all loci tested.« less

Splitting attention across the two visual fields in visual short-term memory.

PubMed

Delvenne, Jean-Francois; Holt, Jessica L

2012-02-01

Humans have the ability to attentionally select the most relevant visual information from their extrapersonal world and to retain it in a temporary buffer, known as visual short-term memory (VSTM). Research suggests that at least two non-contiguous items can be selected simultaneously when they are distributed across the two visual hemifields. In two experiments, we show that attention can also be split between the left and right sides of internal representations held in VSTM. Participants were asked to remember several colors, while cues presented during the delay instructed them to orient their attention to a subset of memorized colors. Experiment 1 revealed that orienting attention to one or two colors strengthened equally participants' memory for those colors, but only when they were from separate hemifields. Experiment 2 showed that in the absence of attentional cues the distribution of the items in the visual field per se had no effect on memory. These findings strongly suggest the existence of independent attentional resources in the two hemifields for selecting and/or consolidating information in VSTM. Copyright © 2011 Elsevier B.V. All rights reserved.

Generation of coherent two-color pulses at two adjacent harmonics in a seeded free-electron laser

NASA Astrophysics Data System (ADS)

Zhao, Zhouyu; Li, Heting; Jia, Qika

2018-02-01

The growing requirements of pump-probe techniques and nonlinear optics experiments greatly promote the studies of two-color free-electron lasers (FELs). We propose a new method to generate coherent two-color pulses in a high-gain harmonic generation (HGHG) FEL. In this scheme, an initial tilted electron beam is sent though the modulator and dispersive section of an HGHG FEL to generate the bunching at harmonics of the seed laser. Then a transverse gradient undulator (TGU) is adopted as the radiator and in such radiator, only two separated fractions of the tilted beam will resonate at two adjacent harmonics of the seed laser and are enabled to emit the coherent two-color pulses simultaneously. The time separation between the two pulses are on the order of hundreds of femtoseconds, and can be precisely controlled by varying the tilted amplitude of the electron beam and/or the transverse gradient of the TGU radiator. Numerical simulations confirm the validity and feasibility of this scheme in the extreme ultraviolet waveband.

Laser Digital Cinema

NASA Astrophysics Data System (ADS)

Takeuchi, Eric B.; Flint, Graham W.; Bergstedt, Robert; Solone, Paul J.; Lee, Dicky; Moulton, Peter F.

2001-03-01

Electronic cinema projectors are being developed that use a digital micromirror device (DMDTM) to produce the image. Photera Technologies has developed a new architecture that produces truly digital imagery using discrete pulse trains of red, green, and blue light in combination with a DMDTM where in the number of pulses that are delivered to the screen during a given frame can be defined in a purely digital fashion. To achieve this, a pulsed RGB laser technology pioneered by Q-Peak is combined with a novel projection architecture that we refer to as Laser Digital CameraTM. This architecture provides imagery wherein, during the time interval of each frame, individual pixels on the screen receive between zero and 255 discrete pulses of each color; a circumstance which yields 24-bit color. Greater color depth, or increased frame rate is achievable by increasing the pulse rate of the laser. Additionally, in the context of multi-screen theaters, a similar architecture permits our synchronously pulsed RGB source to simultaneously power three screens in a color sequential manner; thereby providing an efficient use of photons, together with the simplifications which derive from using a single DMDTM chip in each projector.

In-situ USAXS/SAXS Investigation of Tunable Structural Color in Amorphous Photonic Crystals During Electrophoretic Deposition

NASA Astrophysics Data System (ADS)

Bukosky, Scott; Hammons, Joshua; Han, Jinkyu; Freyman, Megan; Lee, Elaine; Cook, Caitlyn; Kuntz, Joshua; Worsley, Marcus; Han, Thomas Yong; Ristenpart, William; Pascall, Andrew

2017-11-01

Amorphous photonic crystals (APCs) formed via electrophoretic deposition (EPD) exhibit non-iridescent, angle-independent, structural colors believed to arise from changes in the particle-particle interactions and inter-particle spacing, representing a potential new paradigm for display technologies. However, particle dynamics on nanometer length scales that govern the displayed color, crystallinity, and other characteristics of the photonic structures, are not well understood. In this work, in-situ USAXS/SAXS studies of three-dimensional colloidal particle arrays were performed in order to identify their structural response to applied external electric fields. These results were compared to simultaneously acquired UV-Vis spectra to tie the overall electrically induced structure of the APCs directly to the observed changes in visible color. The structural evolution of the APCs provides new information regarding the correlation between nano-scale particle-particle interactions and the corresponding optical response. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-736068.

Presentation-order effects for aesthetic stimulus preference.

PubMed

Englund, Mats P; Hellström, Åke

2012-10-01

For preference comparisons of paired successive musical excerpts, Koh (American Journal of Psychology, 80, 171-185, 1967) found time-order effects (TOEs) that correlated negatively with stimulus valence-the first (vs. the second) of two unpleasant (vs. two pleasant) excerpts tended to be preferred. We present three experiments designed to investigate whether valence-level-dependent order effects for aesthetic preference (a) can be accounted for using Hellström's (e.g., Journal of Experimental Psychology: Human Perception and Performance, 5, 460-477, 1979) sensation-weighting (SW) model, (b) can be generalized to successive and to simultaneous visual stimuli, and (c) vary, in accordance with the stimulus weighting, with interstimulus interval (ISI; for successive stimuli) or stimulus duration (for simultaneous stimuli). Participants compared paired successive jingles (Exp. 1), successive color patterns (Exp. 2), and simultaneous color patterns (Exp. 3), selecting the preferred stimulus. The results were well described by the SW model, which provided a better fit than did two extended versions of the Bradley-Terry-Luce model. Experiments 1 and 2 revealed higher weights for the second stimulus than for the first, and negatively valence-level-dependent TOEs. In Experiment 3, there was no laterality effect on the stimulus weighting and no valence-level-dependent space-order effects (SOEs). In terms of the SW model, the valence-level-dependent TOEs can be explained as a consequence of differential stimulus weighting in combination with stimulus valence varying from low to high, and the absence of valence-level-dependent SOEs as a consequence of the absence of differential weighting. For successive stimuli, there were no important effects of ISI on weightings and TOEs, and, for simultaneous stimuli, duration had only a small effect on the weighting.

Two color holographic interferometry for microgravity application

NASA Technical Reports Server (NTRS)

Trolinger, James D.

1993-01-01

Holographic interferometry is a primary candidate for the measurement of temperature and concentration in various crystal growth experiments destined for space. The method measures refractive index changes in the experiment test cell. A refractive index change can be caused by concentration changes, temperature changes, or a combination of temperature and concentration changes. If the refractive index changes are caused by temperature and concentration changes occurring simultaneously in the experiment test cell, the contributions by the two effects cannot be separated by conventional measurement methods. By using two wavelengths, two independent interferograms can be produced from the reconstruction of the hologram. The two interferograms will be different due to dispersion properties of fluid materials. These differences provide the additional information that allows the separation of simultaneously occurring temperature and concentration gradients. There is no other technique available that can provide this type of information. The primary objectives of this effort are to experimentally verify the mathematical theory of two color holographic interferometry and to determine the practical value of this technique for space application. To achieve these objectives, the accuracy and sensitivity of the technique must be determined for geometry's and materials that are relevant to the Materials Processing in the Space program of NASA. This will be achieved through the use of a specially designed two-color holographic interferometry breadboard optical system. In addition to experiments to achieve the primary goals, the breadboard will also provide inputs to the design of an optimum space flight system.

Improving the Perceptual Performance of Learning Disabled Second Graders through Computer Assisted Instruction.

ERIC Educational Resources Information Center

Burke, James P.

The practicum designed a perceptual activities program for learning disabled second graders using computer-assisted instruction. The program develops skills involving visual motor coordination, figure-ground differentiation, form constancy, position in space, and spatial relationships. Five behavioral objectives for each developmental area were…

Three Centuries of American Inequality.

ERIC Educational Resources Information Center

Lindert, Peter H.; Williamson, Jeffrey G.

Income inequality in the United States displays considerable variance since the seventeenth century. There is no eternal constancy to the degree of inequality in total income, in labor earnings, or in income from conventional nonhuman wealth either before or after the effects of government taxes and spending. When all the necessary adjustments to…

Evaluating the Effectiveness of a Personal Response System in the Classroom

ERIC Educational Resources Information Center

Shaffer, Dennis M.; Collura, Michael J.

2009-01-01

We evaluated the effectiveness of the use of an electronic personal response system (or "clickers") during an introductory psychology lecture on perceptual constancy. We graphed and projected student responses to questions during the lecture onto a large-screen display in Microsoft PowerPoint. The distributions of answers corresponded…

Specialist Osmia bees forage indiscriminately among hybridizing Balsamorhiza floral hosts

Treesearch

James H. Cane

2011-01-01

Pollinators, even floral generalists (=polyleges), typically specialize during individual foraging bouts, infrequently switching between floral hosts. Such transient floral constancy restricts pollen flow, and thereby gene flow, to conspecific flowers in mixed plant communities. Where incipient flowering species meet, however, weak cross-fertility and often similar...

Shame: The Emotional Basis of Library Anxiety

ERIC Educational Resources Information Center

McAfee, Erin L.

2018-01-01

In 1986, Constance Mellon found that 75 to 85 percent of undergraduate students experienced library anxiety as well as shame about their anxiety. Fifteen years earlier, Helen Block Lewis began her groundbreaking research in shame theory. This paper explores the affective components of library anxiety using the pioneering research of Constance…

Structural Integrity in Measures of Self Concept.

ERIC Educational Resources Information Center

Stenner, A. Jackson; Katzenmeyer, W.G.

Structural integrity of a measure is defined in terms of its replicability, constancy, invariance, and stability. Work completed in the development and validation of the Self Observation Scales (SOS) Primary Level (Stenner and Katzenmeyer, 1973) serves to illustrate one method of establishing structural integrity. The name of each scale of the SOS…

Making Sense of Multiple Interpretations

ERIC Educational Resources Information Center

Dougherty, Jack

2004-01-01

Some teaching innovations arise from a combination of good intentions, last-minute planning, and incredible luck. In this article, the author discusses the different interpretations of the students on Constance Curry's 'Silver Rights' and David Cecelski's 'Along Freedom Road,' the two books he assigns to the class in the history of education…

History of Physics and Conceptual Constructions: The Case of Magnetism

ERIC Educational Resources Information Center

Voutsina, Lambrini; Ravanis, Konstantinos

2011-01-01

This study documents the mental representations of magnetism constructed by students aged 15-17 and attempts to investigate whether these display the characteristics of models with an inner cohesiveness and constancy; whether they share common features with typical historical models of the Sciences; and whether they evolve through conventional…

Recognizing and honoring the life and achievements of Constance Baker Motley, a judge for the United States District Court, Southern District of New York.

THOMAS, 111th Congress

Rep. Rangel, Charles B. [D-NY-15

2009-02-10

House - 07/26/2010 Referred to the Subcommittee on the Constitution, Civil Rights, and Civil Liberties. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Mechanical Device Traces Parabolas

NASA Technical Reports Server (NTRS)

Soper, Terry A.

1989-01-01

Mechanical device simplifies generation of parabolas of various focal lengths. Based on fundamental geometrical construction of parabola. Constancy of critical total distance enforced by maintaining cable in tension. Applications of device include design of paraboloidal antennas, approximating catenaries on drawings of powerlines or long-wire antennas, and general tracing of parabolas on drawings.

Total Quality Management Case Study in a Navy Headquarters Organization

DTIC Science & Technology

1990-02-01

A-0 APPENDIX B--DEMING’S 14 PRINCIPLES OF MANAGEMENT .............................. B-0 APPENDIX C--NAVAIR QM B CHARTER...Taylor, Logistics Intern A-I APPENDIX B DEMING’S 14 PRINCIPLES OF MANAGEMENT B-0 DEMING’S 14 PRINCIPLES OF MANAGEMENT 1. Create constancy of purpose

Alaska High Altitude Photography Program

NASA Technical Reports Server (NTRS)

Petersen, Earl V.; Knutson, Martin A.; Ekstrand, Robert E.

1986-01-01

In 1978, the Alaska High Altitude Photography Program was initiated to obtain simultaneous black and white and color IR aerial photography of Alaska. Dual RC-10 and Zeiss camera systems were used for this program on NASA's U-2 and WB-57F, respectively. Data collection, handling, and distribution are discussed as well as general applications and the current status.

Pulse Oximetry in the Physics Lab: A Colorful Alternative to Traditional Optics Curricula

ERIC Educational Resources Information Center

Kutschera, Ellynne; Dunlap, Justin C.; Byrd, Misti; Norlin, Casey; Widenhorn, Ralf

2013-01-01

We designed a physics laboratory exercise around pulse oximetry, a noninvasive medical technique used to assess a patient's blood oxygen saturation. An alternative to a traditional optics and light lab, this exercise teaches the principles of light absorption, spectroscopy, and the properties of light, while simultaneously studying a common…

Color-Changing Microfiber-Based Multifunctional Window Screen for Capture and Visualized Monitoring of NH3.

PubMed

Wang, Zhen; Yuan, Xinxin; Cong, Shan; Chen, Zhigang; Li, Qingwen; Geng, Fengxia; Zhao, Zhigang

2018-05-02

Air pollution is one of the most serious issues affecting the world today. Instead of expensive and energy-intensive air filtering devices, a fiber-based transparent air filter coated on a window screen is seen as one of the state-of-the-art filtration technologies to combat the seriously growing problem, delivering the advantages of simplicity, convenience, and high filtering efficiency. However, such a window screen is currently limited to particulate matter (PM) filtration and ineffective with other air pollutants. Here, we report the use of a newfangled type of color-changing fibers, porous Prussian blue analogues (CuHCF)/polymer composite microfibers, for transparent window screens toward air pollutant filtration. To increase pollution filtration, pores and dimples are purposely introduced to the fibers using binary solvent systems through a nonsolvent-induced phase separation mechanism. Such composite microfibers overcome some of the limitations of those previously used fibers and could simultaneously capture PM 2.5 , PM 10 , and NH 3 with high efficiency. More interestingly, a distinct color change is observed upon exposure to air pollutants in such window screens, which provides multifunctional capability of simultaneous pollutant capture and naked eye screening of the pollutant amount. Specifically, in the case of long-term exposure to low-concentration NH 3 , the symbol displayed in such window screens changes from yellow color to brown and the coloration rate is directly controlled by the NH 3 concentration, which may serve as a careful reminder for those people who are repeatedly exposed to low-concentration ammonia gas (referred to as chronic poisoning). In contrast, after short-term exposure to a high concentration of ammonia gas, the yellow symbol immediately becomes blackened, which provides timely information about the risk of acute ammonia poisoning or even ammonia explosion. Further spectroscopic results show that the chromatic behaviors in response to different concentrations of NH 3 are fundamentally different, which is related to the different locations of ammonia in the lattice of CuHCF, either in its interstitial sites or at the Fe(CN) 6 vacancy sites, largely distinguished by the absence or presence of atmospheric moisture.

Evolution of male coloration during a post-Pleistocene radiation of Bahamas mosquitofish (Gambusia hubbsi).

PubMed

Martin, Ryan A; Riesch, Rüdiger; Heinen-Kay, Justa L; Langerhans, R Brian

2014-02-01

Sexual signal evolution can be complex because multiple factors influence the production, transmission, and reception of sexual signals, as well as receivers' responses to them. To grasp the relative importance of these factors in generating signal diversity, we must simultaneously investigate multiple selective agents and signaling traits within a natural system. We use the model system of the radiation of Bahamas mosquitofish (Gambusia hubbsi) inhabiting blue holes to test the effects of resource availability, male body size and other life-history traits, key aspects of the transmission environment, sex ratio, and predation risk on variation in multiple male color traits. Consistent with previous work examining other traits in this system, several color traits have repeatedly diverged between predation regimes, exhibiting greater elaboration in the absence of predators. However, other factors proved influential as well, with variation in resource levels, body size, relative testes size, and background water color being especially important for several color traits. For one prominent signaling trait, orange dorsal fins, we further confirmed a genetic basis underlying population differences using a laboratory common-garden experiment. We illustrate a promising approach for gaining a detailed understanding of the many contributing factors in the evolution of multivariate sexual signals. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Improved Efficiency and Enhanced Color Quality of Light-Emitting Diodes with Quantum Dot and Organic Hybrid Tandem Structure.

PubMed

Zhang, Heng; Feng, Yuanxiang; Chen, Shuming

2016-10-03

Light-emitting diodes based on organic (OLEDs) and colloidal quantum dot (QLEDs) are widely considered as next-generation display technologies because of their attractive advantages such as self-emitting and flexible form factor. The OLEDs exhibit relatively high efficiency, but their color saturation is quite poor compared with that of QLEDs. In contrast, the QLEDs show very pure color emission, but their efficiency is lower than that of OLEDs currently. To combine the advantages and compensate for the weaknesses of each other, we propose a hybrid tandem structure which integrates both OLED and QLED in a single device architecture. With ZnMgO/Al/HATCN interconnecting layer, hybrid tandem LEDs are successfully fabricated. The demonstrated hybrid tandem devices feature high efficiency and high color saturation simultaneously; for example, the devices exhibit maximum current efficiency and external quantum efficiency of 96.28 cd/A and 25.90%, respectively. Meanwhile, the full width at half-maximum of the emission spectra is remarkably reduced from 68 to 44 nm. With the proposed hybrid tandem structure, the color gamut of the displays can be effectively increased from 81% to 100% NTSC. The results indicate that the advantages of different LED technologies can be combined in a hybrid tandem structure.