MovieMaker: a web server for rapid rendering of protein motions and interactions

PubMed Central

Maiti, Rajarshi; Van Domselaar, Gary H.; Wishart, David S.

2005-01-01

MovieMaker is a web server that allows short (∼10 s), downloadable movies of protein motions to be generated. It accepts PDB files or PDB accession numbers as input and automatically calculates, renders and merges the necessary image files to create colourful animations covering a wide range of protein motions and other dynamic processes. Users have the option of animating (i) simple rotation, (ii) morphing between two end-state conformers, (iii) short-scale, picosecond vibrations, (iv) ligand docking, (v) protein oligomerization, (vi) mid-scale nanosecond (ensemble) motions and (vii) protein folding/unfolding. MovieMaker does not perform molecular dynamics calculations. Instead it is an animation tool that uses a sophisticated superpositioning algorithm in conjunction with Cartesian coordinate interpolation to rapidly and automatically calculate the intermediate structures needed for many of its animations. Users have extensive control over the rendering style, structure colour, animation quality, background and other image features. MovieMaker is intended to be a general-purpose server that allows both experts and non-experts to easily generate useful, informative protein animations for educational and illustrative purposes. MovieMaker is accessible at . PMID:15980488

Field-Portable Pixel Super-Resolution Colour Microscope

PubMed Central

Greenbaum, Alon; Akbari, Najva; Feizi, Alborz; Luo, Wei; Ozcan, Aydogan

2013-01-01

Based on partially-coherent digital in-line holography, we report a field-portable microscope that can render lensfree colour images over a wide field-of-view of e.g., >20 mm2. This computational holographic microscope weighs less than 145 grams with dimensions smaller than 17×6×5 cm, making it especially suitable for field settings and point-of-care use. In this lensfree imaging design, we merged a colorization algorithm with a source shifting based multi-height pixel super-resolution technique to mitigate ‘rainbow’ like colour artefacts that are typical in holographic imaging. This image processing scheme is based on transforming the colour components of an RGB image into YUV colour space, which separates colour information from brightness component of an image. The resolution of our super-resolution colour microscope was characterized using a USAF test chart to confirm sub-micron spatial resolution, even for reconstructions that employ multi-height phase recovery to handle dense and connected objects. To further demonstrate the performance of this colour microscope Papanicolaou (Pap) smears were also successfully imaged. This field-portable and wide-field computational colour microscope could be useful for tele-medicine applications in resource poor settings. PMID:24086742

Field-portable pixel super-resolution colour microscope.

PubMed

Greenbaum, Alon; Akbari, Najva; Feizi, Alborz; Luo, Wei; Ozcan, Aydogan

2013-01-01

Based on partially-coherent digital in-line holography, we report a field-portable microscope that can render lensfree colour images over a wide field-of-view of e.g., >20 mm(2). This computational holographic microscope weighs less than 145 grams with dimensions smaller than 17×6×5 cm, making it especially suitable for field settings and point-of-care use. In this lensfree imaging design, we merged a colorization algorithm with a source shifting based multi-height pixel super-resolution technique to mitigate 'rainbow' like colour artefacts that are typical in holographic imaging. This image processing scheme is based on transforming the colour components of an RGB image into YUV colour space, which separates colour information from brightness component of an image. The resolution of our super-resolution colour microscope was characterized using a USAF test chart to confirm sub-micron spatial resolution, even for reconstructions that employ multi-height phase recovery to handle dense and connected objects. To further demonstrate the performance of this colour microscope Papanicolaou (Pap) smears were also successfully imaged. This field-portable and wide-field computational colour microscope could be useful for tele-medicine applications in resource poor settings.

The development of vector based 2.5D print methods for a painting machine

NASA Astrophysics Data System (ADS)

Parraman, Carinna

2013-02-01

Through recent trends in the application of digitally printed decorative finishes to products, CAD, 3D additive layer manufacturing and research in material perception, [1, 2] there is a growing interest in the accurate rendering of materials and tangible displays. Although current advances in colour management and inkjet printing has meant that users can take for granted high-quality colour and resolution in their printed images, digital methods for transferring a photographic coloured image from screen to paper is constrained by pixel count, file size, colorimetric conversion between colour spaces and the gamut limits of input and output devices. This paper considers new approaches to applying alternative colour palettes by using a vector-based approach through the application of paint mixtures, towards what could be described as a 2.5D printing method. The objective is to not apply an image to a textured surface, but where texture and colour are integral to the mark, that like a brush, delineates the contours in the image. The paper describes the difference between the way inks and paints are mixed and applied. When transcribing the fluid appearance of a brush stroke, there is a difference between a halftone printed mark and a painted mark. The issue of surface quality is significant to subjective qualities when studying the appearance of ink or paint on paper. The paper provides examples of a range of vector marks that are then transcribed into brush stokes by the painting machine.

MovieMaker: a web server for rapid rendering of protein motions and interactions.

PubMed

Maiti, Rajarshi; Van Domselaar, Gary H; Wishart, David S

2005-07-01

MovieMaker is a web server that allows short ( approximately 10 s), downloadable movies of protein motions to be generated. It accepts PDB files or PDB accession numbers as input and automatically calculates, renders and merges the necessary image files to create colourful animations covering a wide range of protein motions and other dynamic processes. Users have the option of animating (i) simple rotation, (ii) morphing between two end-state conformers, (iii) short-scale, picosecond vibrations, (iv) ligand docking, (v) protein oligomerization, (vi) mid-scale nanosecond (ensemble) motions and (vii) protein folding/unfolding. MovieMaker does not perform molecular dynamics calculations. Instead it is an animation tool that uses a sophisticated superpositioning algorithm in conjunction with Cartesian coordinate interpolation to rapidly and automatically calculate the intermediate structures needed for many of its animations. Users have extensive control over the rendering style, structure colour, animation quality, background and other image features. MovieMaker is intended to be a general-purpose server that allows both experts and non-experts to easily generate useful, informative protein animations for educational and illustrative purposes. MovieMaker is accessible at http://wishart.biology.ualberta.ca/moviemaker.

Crowdsourcing as an Analytical Method: Metrology of Smartphone Measurements in Heritage Science.

PubMed

Brigham, Rosie; Grau-Bové, Josep; Rudnicka, Anna; Cassar, May; Strlic, Matija

2018-06-18

This research assesses the precision, repeatability, and accuracy of crowdsourced scientific measurements, and whether their quality is sufficient to provide usable results. Measurements of colour and area were chosen because of the possibility of producing them with smartphone cameras. The quality of the measurements was estimated experimentally by comparing data contributed by anonymous participants in heritage sites with reference measurements of known accuracy and precision. Participants performed the measurements by taking photographs with their smartphones, from which colour and dimensional data could be extracted. The results indicate that smartphone measurements provided by citizen scientists can be used to measure changes in colour, but that the performance is strongly dependent on the measured colour coordinate. The same method can be used to measure areas when the difference in colour with the neighbouring areas is large enough. These results render the method useful in some heritage science contexts, but higher precision would be desirable. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

No rainbow for grey bamboo sharks: evidence for the absence of colour vision in sharks from behavioural discrimination experiments.

PubMed

Schluessel, V; Rick, I P; Plischke, K

2014-11-01

Despite convincing data collected by microspectrophotometry and molecular biology, rendering sharks colourblind cone monochromats, the question of whether sharks can perceive colour had not been finally resolved in the absence of any behavioural experiments compensating for the confounding factor of brightness. The present study tested the ability of juvenile grey bamboo sharks to perceive colour in an experimental design based on a paradigm established by Karl von Frisch using colours in combination with grey distractor stimuli of equal brightness. Results showed that contrasts but no colours could be discriminated. Blue and yellow stimuli were not distinguished from a grey distractor stimulus of equal brightness but could be distinguished from distractor stimuli of varying brightness. In addition, different grey stimuli were distinguished significantly above chance level from one another. In conclusion, the behavioural results support the previously collected physiological data on bamboo sharks, which mutually show that the grey bamboo shark, like several marine mammals, is a cone monochromate and colourblind.

Does Ethylene Treatment Mimic the Effects of Pollination on Floral Lifespan and Attractiveness?

PubMed Central

VAN DOORN, WOUTER G.

2002-01-01

In some species pollination may result in rapid changes in perianth colour and form (petal senescence and abscission, flower closure), rendering the flowers less attractive to pollinators. It has been suggested that this effect is mediated by ethylene. Flowers from about 200 species and 50 families were exposed to ethylene (3 ppm for 24 h at 20 °C). The effects on petal senescence and abscission have been described previously. Flower closure and perianth colour changes were generally ethylene‐sensitive, but responses showed no consistency within families. Several flowers known to respond to pollination by rapid cessation of attractiveness were also exposed to ethylene: this produced the same effect as pollination, both on flower colour and form. Species that respond to pollination by changing flower form or colour were found exclusively in families in which the species are generally ethylene‐sensitive (with regard to changes in perianth form and colour). However, several families are generally ethylene‐sensitive but contain no species reported to respond to pollination. PMID:12096797

Cloud-based Monte Carlo modelling of BSSRDF for the rendering of human skin appearance (Conference Presentation)

NASA Astrophysics Data System (ADS)

Doronin, Alexander; Rushmeier, Holly E.; Meglinski, Igor; Bykov, Alexander V.

2016-03-01

We present a new Monte Carlo based approach for the modelling of Bidirectional Scattering-Surface Reflectance Distribution Function (BSSRDF) for accurate rendering of human skin appearance. The variations of both skin tissues structure and the major chromophores are taken into account correspondingly to the different ethnic and age groups. The computational solution utilizes HTML5, accelerated by the graphics processing units (GPUs), and therefore is convenient for the practical use at the most of modern computer-based devices and operating systems. The results of imitation of human skin reflectance spectra, corresponding skin colours and examples of 3D faces rendering are presented and compared with the results of phantom studies.

Poly(vinylpyrrolidone) supported copper nanoclusters: glutathione enhanced blue photoluminescence for application in phosphor converted light emitting devices

NASA Astrophysics Data System (ADS)

Wang, Zhenguang; Susha, Andrei S.; Chen, Bingkun; Reckmeier, Claas; Tomanec, Ondrej; Zboril, Radek; Zhong, Haizheng; Rogach, Andrey L.

2016-03-01

Poly(vinylpyrrolidone) supported Cu nanoclusters were synthesized by reduction of Cu(ii) ions with ascorbic acid in water, and initially showed blue photoluminescence with a quantum yield of 8%. An enhancement of the emission quantum yield has been achieved by treatment of Cu clusters with different electron-rich ligands, with the most pronounced effect (photoluminescence quantum yield of 27%) achieved with glutathione. The bright blue emission of glutathione treated Cu NCs is fully preserved in the solid state powder, which has been combined with commercial green and red phosphors to fabricate down-conversion white light emitting diodes with a high colour rendering index of 92.Poly(vinylpyrrolidone) supported Cu nanoclusters were synthesized by reduction of Cu(ii) ions with ascorbic acid in water, and initially showed blue photoluminescence with a quantum yield of 8%. An enhancement of the emission quantum yield has been achieved by treatment of Cu clusters with different electron-rich ligands, with the most pronounced effect (photoluminescence quantum yield of 27%) achieved with glutathione. The bright blue emission of glutathione treated Cu NCs is fully preserved in the solid state powder, which has been combined with commercial green and red phosphors to fabricate down-conversion white light emitting diodes with a high colour rendering index of 92. Electronic supplementary information (ESI) available: The optical spectra of control experiments for Cu NC synthesis, optimization of the reaction conditions, and spectra for LEDs chips and blue LEDs. See DOI: 10.1039/c6nr00806b

Using digital colour to increase the realistic appearance of SEM micrographs of bloodstains.

PubMed

Hortolà, Policarp

2010-10-01

Although in the scientific-research literature the micrographs from scanning electron microscopes (SEMs) are usually displayed in greyscale, the potential of colour resources provided by the SEM-coupled image-acquiring systems and, subsidiarily, by image-manipulation free softwares deserves be explored as a tool for colouring SEM micrographs of bloodstains. After acquiring greyscale SEM micrographs of a (dark red to the naked eye) human blood smear on grey chert, they were manually obtained in red tone using both the SEM-coupled image-acquiring system and an image-manipulation free software, as well as they were automatically generated in thermal tone using the SEM-coupled system. Red images obtained by the SEM-coupled system demonstrated lower visual-discrimination capability than the other coloured images, whereas those in red generated by the free software rendered better magnitude of scopic information than the red images generated by the SEM-coupled system. Thermal-tone images, although were further from the real sample colour than the red ones, not only increased their realistic appearance over the greyscale images, but also yielded the best visual-discrimination capability among all the coloured SEM micrographs, and fairly enhanced the relief effect of the SEM micrographs over both the greyscale and the red images. The application of digital colour by means of the facilities provided by an SEM-coupled image-acquiring system or, when required, by an image-manipulation free software provides a user-friendly, quick and inexpensive way of obtaining coloured SEM micrographs of bloodstains, avoiding to do sophisticated, time-consuming colouring procedures. Although this work was focused on bloodstains, well probably other monochromatic or quasi-monochromatic samples are also susceptible of increasing their realistic appearance by colouring them using the simple methods utilized in this study.

Texturing of continuous LOD meshes with the hierarchical texture atlas

NASA Astrophysics Data System (ADS)

Birkholz, Hermann

2006-02-01

For the rendering of detailed virtual environments, trade-offs have to be made between image quality and rendering time. An immersive experience of virtual reality always demands high frame-rates with the best reachable image qual-ity. Continuous Level of Detail (cLoD) triangle-meshes provide an continuous spectrum of detail for a triangle mesh that can be used to create view-dependent approximations of the environment in real-time. This enables the rendering with a constant number of triangles and thus with constant frame-rates. Normally the construction of such cLoD mesh representations leads to the loss of all texture information of the original mesh. To overcome this problem, a parameter domain can be created, in order to map the surface properties (colour, texture, normal) to it. This parameter domain can be used to map the surface properties back to arbitrary approximations of the original mesh. The parameter domain is often a simplified version of the mesh to be parameterised. This limits the reachable simplification to the domain mesh which has to map the surface of the original mesh with the least possible stretch. In this paper, a hierarchical domain mesh is presented, that scales between very coarse domain meshes and good property-mapping.

Color appearance and color rendering of HDR scenes: an experiment

NASA Astrophysics Data System (ADS)

Parraman, Carinna; Rizzi, Alessandro; McCann, John J.

2009-01-01

In order to gain a deeper understanding of the appearance of coloured objects in a three-dimensional scene, the research introduces a multidisciplinary experimental approach. The experiment employed two identical 3-D Mondrians, which were viewed and compared side by side. Each scene was subjected to different lighting conditions. First, we used an illumination cube to diffuse the light and illuminate all the objects from each direction. This produced a low-dynamicrange (LDR) image of the 3-D Mondrian scene. Second, in order to make a high-dynamic range (HDR) image of the same objects, we used a directional 150W spotlight and an array of WLEDs assembled in a flashlight. The scenes were significant as each contained exactly the same three-dimensional painted colour blocks that were arranged in the same position in the still life. The blocks comprised 6 hue colours and 5 tones from white to black. Participants from the CREATE project were asked to consider the change in the appearance of a selection of colours according to lightness, hue, and chroma, and to rate how the change in illumination affected appearance. We measured the light coming to the eye from still-life surfaces with a colorimeter (Yxy). We captured the scene radiance using multiple exposures with a number of different cameras. We have begun a programme of digital image processing of these scene capture methods. This multi-disciplinary programme continues until 2010, so this paper is an interim report on the initial phases and a description of the ongoing project.

Signal conflict in spider webs driven by predators and prey

PubMed Central

Blackledge, T. A.

1998-01-01

Variation in the sensory physiologies of organisms can bias the receptions of signals, driving the direction of signal evolution. Sensory drive in the evolution of signals may be particularly important for organisms that confront trade-offs in signal design between the need for conspicuousness to allow effective transfer of information and the need for crypsis of the signal to unintended receivers. Several genera of orb-weaving spiders include conspicuous silk designs, stabilimenta, in the centre of their webs. Stabilimenta can be highly visible signals to predators, warning them of the presence of a noxious, sticky silk web. However, stabilimenta can also be used by prey as a signal in avoidance of webs, creating a trade-off in signal visibility. I argue that the derived spectral properties of stabilimentum silk have resulted in part from this conflict. The innate colour preferences of insects, their ability to learn colours, and the spectral properties of flowers all suggest that the reflectance spectra of stabilimenta renders them relatively cryptic to many insect prey, while maintaining their visibility to vertebrate predators.

Cross-modal prediction changes the timing of conscious access during the motion-induced blindness.

PubMed

Chang, Acer Y C; Kanai, Ryota; Seth, Anil K

2015-01-01

Despite accumulating evidence that perceptual predictions influence perceptual content, the relations between these predictions and conscious contents remain unclear, especially for cross-modal predictions. We examined whether predictions of visual events by auditory cues can facilitate conscious access to the visual stimuli. We trained participants to learn associations between auditory cues and colour changes. We then asked whether congruency between auditory cues and target colours would speed access to consciousness. We did this by rendering a visual target subjectively invisible using motion-induced blindness and then gradually changing its colour while presenting congruent or incongruent auditory cues. Results showed that the visual target gained access to consciousness faster in congruent than in incongruent trials; control experiments excluded potentially confounding effects of attention and motor response. The expectation effect was gradually established over blocks suggesting a role for extensive training. Overall, our findings show that predictions learned through cross-modal training can facilitate conscious access to visual stimuli. Copyright © 2014 Elsevier Inc. All rights reserved.

Changes in water quality in the Owabi water treatment plant in Ghana

NASA Astrophysics Data System (ADS)

Akoto, Osei; Gyamfi, Opoku; Darko, Godfred; Barnes, Victor Rex

2017-03-01

The study was conducted on the status of the quality of water from the Owabi water treatment plant that supplies drinking water to Kumasi, a major city in Ghana, to ascertain the change in quality of water from source to point-of-use. Physico-chemical, bacteriological water quality parameters and trace metal concentration of water samples from five different treatment points from the Owabi water treatment plant were investigated. The raw water was moderately hard with high turbidity and colour that exceeds the WHO guideline limits. Nutrient concentrations were of the following order: NH3 < NO2 - < NO3 - < PO4 3- < SO4 2- and were all below WHO permissible level for drinking water in all the samples at different stages of treatment. Trace metal concentrations of the reservoir were all below WHO limit except chromium (0.06 mg/L) and copper (0.24 mg/L). The bacteriological study showed that the raw water had total coliform (1,766 cfu/100 mL) and faecal coliform (257 cfu/100 mL) that exceeded the WHO standard limits, rendering it unsafe for domestic purposes without treatment. Colour showed strong positive correlation with turbidity ( r = 0.730), TSS ( r ≥ 0.922) and alkalinity (0.564) significant at p < 0.01. The quality of the treated water indicates that colour, turbidity, Cr and Cu levels reduced and fall within the WHO permissible limit for drinking water. Treatment process at the water treatment plant is adjudged to be good.

Attended but unseen: visual attention is not sufficient for visual awareness.

PubMed

Kentridge, R W; Nijboer, T C W; Heywood, C A

2008-02-12

Does any one psychological process give rise to visual awareness? One candidate is selective attention-when we attend to something it seems we always see it. But if attention can selectively enhance our response to an unseen stimulus then attention cannot be a sufficient precondition for awareness. Kentridge, Heywood & Weiskrantz [Kentridge, R. W., Heywood, C. A., & Weiskrantz, L. (1999). Attention without awareness in blindsight. Proceedings of the Royal Society of London, Series B, 266, 1805-1811; Kentridge, R. W., Heywood, C. A., & Weiskrantz, L. (2004). Spatial attention speeds discrimination without awareness in blindsight. Neuropsychologia, 42, 831-835.] demonstrated just such a dissociation in the blindsight subject GY. Here, we test whether the dissociation generalizes to the normal population. We presented observers with pairs of coloured discs, each masked by the subsequent presentation of a coloured annulus. The discs acted as primes, speeding discrimination of the colour of the annulus when they matched in colour and slowing it when they differed. We show that the location of attention modulated the size of this priming effect. However, the primes were rendered invisible by metacontrast-masking and remained unseen despite being attended. Visual attention could therefore facilitate processing of an invisible target and cannot, therefore, be a sufficient precondition for visual awareness.

Structural control of InP/ZnS core/shell quantum dots enables high-quality white LEDs.

PubMed

Kumar, Baskaran Ganesh; Sadeghi, Sadra; Melikov, Rustamzhon; Aria, Mohammad Mohammadi; Jalali, Houman Bahmani; Ow-Yang, Cleva W; Nizamoglu, Sedat

2018-08-24

Herein, we demonstrate that the structural and optical control of InP-based quantum dots (QDs) can lead to high-performance light-emitting diodes (LEDs). Zinc sulphide (ZnS) shells passivate the InP QD core and increase the quantum yield in green-emitting QDs by 13-fold and red-emitting QDs by 8-fold. The optimised QDs are integrated in the liquid state to eliminate aggregation-induced emission quenching and we fabricated white LEDs with a warm, neutral and cool-white appearance by the down-conversion mechanism. The QD-functionalized white LEDs achieve luminous efficiency (LE) up to 14.7 lm W -1 and colour-rendering index up to 80. The structural and optical control of InP/ZnS core/shell QDs enable 23-fold enhancement in LE of white LEDs compared to ones containing only QDs of InP core.

Colour differences in Caucasian and Oriental women's faces illuminated by white LED sources.

PubMed

Melgosa, M; Richard, N; Fernández-Maloigne, C; Xiao, K; de Clermont-Gallerande, H; Jost-Boissard, S; Okajima, K

2018-04-10

To provide an approach to facial contrast, analysing CIELAB colour differences (ΔE* ab,10 ) and its components in women's faces from two different ethnic groups, illuminated by modern white light-emitting diodes (LEDs) or traditional illuminants recommended by the International Commission on Illumination (CIE). We performed spectrophotometric measurements of spectral reflectance factors on forehead and cheek of 87 young healthy women (50 Caucasians and 37 Orientals), plus 5 commercial red lipsticks. We considered a set of 10 white LED illuminants, representative of technologies currently available on the market, plus 8 main illuminants currently recommended by the CIE, representative of conventional incandescent, daylight, and fluorescent light sources. Under each of these 18 illuminants we analysed the magnitude and components of ΔE* ab,10 between Caucasian and Oriental women (considering cheek and forehead), as well as for cheek-forehead and cheek-lipsticks in Caucasian and Oriental women. Colour-inconstancy indices for cheek, forehead, and lipsticks were computed, assuming D65 and A as reference illuminants. ΔE* ab,10 between forehead and cheek were quantitatively and qualitatively different in Orientals and Caucasians, but discrepancies with respect to average values for 18 illuminants were small (1.5% and 5.0% for Orientals and Caucasians, respectively). ΔE* ab,10 between Caucasians and Orientals were also quantitatively and qualitatively different both for forehead and cheek, and discrepancies with respect to average values were again small (1.0% and 3.9% for forehead and cheek, respectively). ΔE* ab,10 between lipsticks and cheek were at least 2 times higher than those between forehead and cheek. Regarding ΔE* ab,10 between lipsticks and cheeks, discrepancies with respect to average values were in the range 1.5% - 12.3%, although higher values of up to 54.2% were found for a white RGB LED. This white RGB LED provided the highest average colour-inconstancy indices: 17.1 and 11.5 CIELAB units, under reference illuminants D65 and A, respectively. Colour contrasts in women's faces under CIE standard illuminants for outdoor and indoor conditions may be strongly altered by using specific white LEDs. More research needs to be done on the impact of spectral power distribution of light sources with high colour rendering indices on visual colour appearance of cosmetic products. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The drama of illumination: artist's approaches to the creation of HDR in paintings and prints

NASA Astrophysics Data System (ADS)

Parraman, Carinna

2010-02-01

For many centuries artists have considered and depicted illumination in art, from the effect of sunlight on objects at different times of the day, of shadows and highlights as cast by the moon, through indirect light as that through an open window or the artificial light of the candle or firelight. The presentation will consider artists who were fascinated by the phenomena of natural and artificial illumination and how they were able to render the natural world as a form of dynamic range through pigment. Artists have been long aware of the psychological aspects of the juxtaposition of colour in exploiting the optical qualities and arranging visual effects in painting and prints. Artists in the 16th century were attempting to develop an extended dynamic range through multi-colour, wood-block printing. Artists working at the height of naturalist realism in the 17th through the 19th century were fascinated by the illusory nature of light on objects. The presentation will also consider the interpretation of dynamic range through the medium of mezzotint, possibly the most subtle of printing methods, which was used by printers to copy paintings, and to create highly original works of art containing a dynamic range of tones.

Conspicuous plumage colours are highly variable

PubMed Central

Szecsenyi, Beatrice; Nakagawa, Shinichi; Peters, Anne

2017-01-01

Elaborate ornamental traits are often under directional selection for greater elaboration, which in theory should deplete underlying genetic variation. Despite this, many ornamental traits appear to remain highly variable and how this essential variation is maintained is a key question in evolutionary biology. One way to address this question is to compare differences in intraspecific variability across different types of traits to determine whether high levels of variation are associated with specific trait characteristics. Here we assess intraspecific variation in more than 100 plumage colours across 55 bird species to test whether colour variability is linked to their level of elaboration (indicated by degree of sexual dichromatism and conspicuousness) or their condition dependence (indicated by mechanism of colour production). Conspicuous colours had the highest levels of variation and conspicuousness was the strongest predictor of variability, with high explanatory power. After accounting for this, there were no significant effects of sexual dichromatism or mechanisms of colour production. Conspicuous colours may entail higher production costs or may be more sensitive to disruptions during production. Alternatively, high variability could also be related to increased perceptual difficulties inherent to discriminating highly elaborate colours. Such psychophysical effects may constrain the exaggeration of animal colours. PMID:28100823

Conspicuous plumage colours are highly variable.

PubMed

Delhey, Kaspar; Szecsenyi, Beatrice; Nakagawa, Shinichi; Peters, Anne

2017-01-25

Elaborate ornamental traits are often under directional selection for greater elaboration, which in theory should deplete underlying genetic variation. Despite this, many ornamental traits appear to remain highly variable and how this essential variation is maintained is a key question in evolutionary biology. One way to address this question is to compare differences in intraspecific variability across different types of traits to determine whether high levels of variation are associated with specific trait characteristics. Here we assess intraspecific variation in more than 100 plumage colours across 55 bird species to test whether colour variability is linked to their level of elaboration (indicated by degree of sexual dichromatism and conspicuousness) or their condition dependence (indicated by mechanism of colour production). Conspicuous colours had the highest levels of variation and conspicuousness was the strongest predictor of variability, with high explanatory power. After accounting for this, there were no significant effects of sexual dichromatism or mechanisms of colour production. Conspicuous colours may entail higher production costs or may be more sensitive to disruptions during production. Alternatively, high variability could also be related to increased perceptual difficulties inherent to discriminating highly elaborate colours. Such psychophysical effects may constrain the exaggeration of animal colours. © 2017 The Author(s).

Real-time colouring and filtering with graphics shaders

NASA Astrophysics Data System (ADS)

Vohl, D.; Fluke, C. J.; Barnes, D. G.; Hassan, A. H.

2017-11-01

Despite the popularity of the Graphics Processing Unit (GPU) for general purpose computing, one should not forget about the practicality of the GPU for fast scientific visualization. As astronomers have increasing access to three-dimensional (3D) data from instruments and facilities like integral field units and radio interferometers, visualization techniques such as volume rendering offer means to quickly explore spectral cubes as a whole. As most 3D visualization techniques have been developed in fields of research like medical imaging and fluid dynamics, many transfer functions are not optimal for astronomical data. We demonstrate how transfer functions and graphics shaders can be exploited to provide new astronomy-specific explorative colouring methods. We present 12 shaders, including four novel transfer functions specifically designed to produce intuitive and informative 3D visualizations of spectral cube data. We compare their utility to classic colour mapping. The remaining shaders highlight how common computation like filtering, smoothing and line ratio algorithms can be integrated as part of the graphics pipeline. We discuss how this can be achieved by utilizing the parallelism of modern GPUs along with a shading language, letting astronomers apply these new techniques at interactive frame rates. All shaders investigated in this work are included in the open source software shwirl (Vohl 2017).

Red fluorescence of the triplefin Tripterygion delaisi is increasingly visible against background light with increasing depth.

PubMed

Bitton, Pierre-Paul; Harant, Ulrike K; Fritsch, Roland; Champ, Connor M; Temple, Shelby E; Michiels, Nico K

2017-03-01

The light environment in water bodies changes with depth due to the absorption of short and long wavelengths. Below 10 m depth, red wavelengths are almost completely absent rendering any red-reflecting animal dark and achromatic. However, fluorescence may produce red coloration even when red light is not available for reflection. A large number of marine taxa including over 270 fish species are known to produce red fluorescence, yet it is unclear under which natural light environment fluorescence contributes perceptively to their colours. To address this question we: (i) characterized the visual system of Tripterygion delaisi, which possesses fluorescent irides, (ii) separated the colour of the irides into its reflectance and fluorescence components and (iii) combined these data with field measurements of the ambient light environment to calculate depth-dependent perceptual chromatic and achromatic contrasts using visual modelling. We found that triplefins have cones with at least three different spectral sensitivities, including differences between the two members of the double cones, giving them the potential for trichromatic colour vision. We also show that fluorescence contributes increasingly to the radiance of the irides with increasing depth. Our results support the potential functionality of red fluorescence, including communicative roles such as species and sex identity, and non-communicative roles such as camouflage.

Most and Least Preferred Colours Differ According to Object Context: New Insights from an Unrestricted Colour Range

PubMed Central

Jonauskaite, Domicele; Mohr, Christine; Antonietti, Jean-Philippe; Spiers, Peter M.; Althaus, Betty; Anil, Selin; Dael, Nele

2016-01-01

Humans like some colours and dislike others, but which particular colours and why remains to be understood. Empirical studies on colour preferences generally targeted most preferred colours, but rarely least preferred (disliked) colours. In addition, findings are often based on general colour preferences leaving open the question whether results generalise to specific objects. Here, 88 participants selected the colours they preferred most and least for three context conditions (general, interior walls, t-shirt) using a high-precision colour picker. Participants also indicated whether they associated their colour choice to a valenced object or concept. The chosen colours varied widely between individuals and contexts and so did the reasons for their choices. Consistent patterns also emerged, as most preferred colours in general were more chromatic, while for walls they were lighter and for t-shirts they were darker and less chromatic compared to least preferred colours. This meant that general colour preferences could not explain object specific colour preferences. Measures of the selection process further revealed that, compared to most preferred colours, least preferred colours were chosen more quickly and were less often linked to valenced objects or concepts. The high intra- and inter-individual variability in this and previous reports furthers our understanding that colour preferences are determined by subjective experiences and that most and least preferred colours are not processed equally. PMID:27022909

Most and Least Preferred Colours Differ According to Object Context: New Insights from an Unrestricted Colour Range.

PubMed

Jonauskaite, Domicele; Mohr, Christine; Antonietti, Jean-Philippe; Spiers, Peter M; Althaus, Betty; Anil, Selin; Dael, Nele

2016-01-01

Humans like some colours and dislike others, but which particular colours and why remains to be understood. Empirical studies on colour preferences generally targeted most preferred colours, but rarely least preferred (disliked) colours. In addition, findings are often based on general colour preferences leaving open the question whether results generalise to specific objects. Here, 88 participants selected the colours they preferred most and least for three context conditions (general, interior walls, t-shirt) using a high-precision colour picker. Participants also indicated whether they associated their colour choice to a valenced object or concept. The chosen colours varied widely between individuals and contexts and so did the reasons for their choices. Consistent patterns also emerged, as most preferred colours in general were more chromatic, while for walls they were lighter and for t-shirts they were darker and less chromatic compared to least preferred colours. This meant that general colour preferences could not explain object specific colour preferences. Measures of the selection process further revealed that, compared to most preferred colours, least preferred colours were chosen more quickly and were less often linked to valenced objects or concepts. The high intra- and inter-individual variability in this and previous reports furthers our understanding that colour preferences are determined by subjective experiences and that most and least preferred colours are not processed equally.

Production of an anthocyanin-rich food colourant from Thymus moroderi and its application in foods.

PubMed

Díaz-García, Miriam Cristina; Castellar, María Rosario; Obón, José María; Obón, Concepción; Alcaraz, Francisco; Rivera, Diego

2015-04-01

Anthocyanins and other polyphenols from flowers and bracts of Thymus sp. are studied. An anthocyanin-rich food colourant with interesting high antioxidant activity from Thymus moroderi has been obtained, and applied to colour foods. Anthocyanins and other polyphenols from T. moroderi and another five Thymus sp. were extracted in methanol/hydrochloric acid 0.1 mol L(-1) (50/50, v/v) 2 h stirring at 50 °C. They were identified and quantified by HPLC-PDA-MS and UHPLC-PDA-fluorescence, as total individual polyphenols. Total polyphenols were also determined. Flowers had higher anthocyanins and other polyphenols concentrations than bracts; for example, total polyphenols content of T. moroderi were 131.58 and 61.98 g GAE kg(-1) vegetal tissue, respectively. A liquid concentrated colourant was obtained from T. moroderi using water/citric acid as solvent. It was characterised and compared with other two commercial anthocyanin-rich food colourants from red grape skin and red carrot (colour strength of 1.7 and 3.6 AU, respectively). T. moroderi colourant had 1.2 AU colour strength, and high storage stability (>97.1% remaining colour after 110 days at 4 °C). It showed a higher polyphenols content than commercial colourants. Its antioxidant activity was 0.707 mmol Trolox eq. g(-1) plant dry weight, 69.5 times higher than red carrot. The three colourants were applied to colour yogurts, giving pinky tonalities. The colour did not change evidently (ΔE*(ab)  < 3) when stored under refrigeration during 1 month. T. moroderi can be a source of anthocyanin-rich food colourant (E-163) with both high polyphenols content and high antioxidant activity. This colourant gives a stable colour to a yogurt during 1 month. These results expand the use of natural colourants. © 2014 Society of Chemical Industry.

Fruit over sunbed: carotenoid skin colouration is found more attractive than melanin colouration.

PubMed

Lefevre, Carmen E; Perrett, David I

2015-01-01

Skin colouration appears to play a pivotal part in facial attractiveness. Skin yellowness contributes to an attractive appearance and is influenced both by dietary carotenoids and by melanin. While both increased carotenoid colouration and increased melanin colouration enhance apparent health in Caucasian faces by increasing skin yellowness, it remains unclear, firstly, whether both pigments contribute to attractiveness judgements, secondly, whether one pigment is clearly preferred over the other, and thirdly, whether these effects depend on the sex of the face. Here, in three studies, we examine these questions using controlled facial stimuli transformed to be either high or low in (a) carotenoid colouration, or (b) melanin colouration. We show, firstly, that both increased carotenoid colouration and increased melanin colouration are found attractive compared to lower levels of these pigments. Secondly, we show that carotenoid colouration is consistently preferred over melanin colouration when levels of colouration are matched. In addition, we find an effect of the sex of stimuli with stronger preferences for carotenoids over melanin in female compared to male faces, irrespective of the sex of the observer. These results are interpreted as reflecting preferences for sex-typical skin colouration: men have darker skin than women and high melanization in male faces may further enhance this masculine trait, thus carotenoid colouration is not less desirable, but melanin colouration is relatively more desirable in males compared to females. Taken together, our findings provide further support for a carotenoid-linked health-signalling system that is highly important in mate choice.

A multi-directional backlight for a wide-angle, glasses-free three-dimensional display.

PubMed

Fattal, David; Peng, Zhen; Tran, Tho; Vo, Sonny; Fiorentino, Marco; Brug, Jim; Beausoleil, Raymond G

2013-03-21

Multiview three-dimensional (3D) displays can project the correct perspectives of a 3D image in many spatial directions simultaneously. They provide a 3D stereoscopic experience to many viewers at the same time with full motion parallax and do not require special glasses or eye tracking. None of the leading multiview 3D solutions is particularly well suited to mobile devices (watches, mobile phones or tablets), which require the combination of a thin, portable form factor, a high spatial resolution and a wide full-parallax view zone (for short viewing distance from potentially steep angles). Here we introduce a multi-directional diffractive backlight technology that permits the rendering of high-resolution, full-parallax 3D images in a very wide view zone (up to 180 degrees in principle) at an observation distance of up to a metre. The key to our design is a guided-wave illumination technique based on light-emitting diodes that produces wide-angle multiview images in colour from a thin planar transparent lightguide. Pixels associated with different views or colours are spatially multiplexed and can be independently addressed and modulated at video rate using an external shutter plane. To illustrate the capabilities of this technology, we use simple ink masks or a high-resolution commercial liquid-crystal display unit to demonstrate passive and active (30 frames per second) modulation of a 64-view backlight, producing 3D images with a spatial resolution of 88 pixels per inch and full-motion parallax in an unprecedented view zone of 90 degrees. We also present several transparent hand-held prototypes showing animated sequences of up to six different 200-view images at a resolution of 127 pixels per inch.

A dual-emitting core-shell carbon dot-silica-phosphor composite for white light emission

NASA Astrophysics Data System (ADS)

Chen, Yonghao; Lei, Bingfu; Zheng, Mingtao; Zhang, Haoran; Zhuang, Jianle; Liu, Yingliang

2015-11-01

A unique dual-emitting core-shell carbon dot-silica-phosphor (CDSP) was constructed from carbon dots (CDs), tetraethoxysilane (TEOS) and Sr2Si5N8:Eu2+ phosphor through a one-pot sol-gel method. Blue emitting CDs uniformly disperse in the silica layer covering the orange emitting phosphor via a polymerization process, which makes CDSP achieve even white light emission. Tunable photoluminescence of CDSP is observed and the preferable white light emission is achieved through changing the excitation wavelength or controlling the mass ratio of the phosphor. When CDSP powders with a phosphor rate of 3.9% and 5.1% are excited at a wavelength of 400 nm, preferable white light emission is observed, with Commission Internationale de l'Eclairage (CIE) coordinates of (0.32, 0.32) and (0.34, 0.32), respectively. Furthermore, CDSP can mix well with epoxy resin to emit strong and even white light, and based on this, a CDSP-based white LED with a high colour rendering index (CRI) of 94 was fabricated.A unique dual-emitting core-shell carbon dot-silica-phosphor (CDSP) was constructed from carbon dots (CDs), tetraethoxysilane (TEOS) and Sr2Si5N8:Eu2+ phosphor through a one-pot sol-gel method. Blue emitting CDs uniformly disperse in the silica layer covering the orange emitting phosphor via a polymerization process, which makes CDSP achieve even white light emission. Tunable photoluminescence of CDSP is observed and the preferable white light emission is achieved through changing the excitation wavelength or controlling the mass ratio of the phosphor. When CDSP powders with a phosphor rate of 3.9% and 5.1% are excited at a wavelength of 400 nm, preferable white light emission is observed, with Commission Internationale de l'Eclairage (CIE) coordinates of (0.32, 0.32) and (0.34, 0.32), respectively. Furthermore, CDSP can mix well with epoxy resin to emit strong and even white light, and based on this, a CDSP-based white LED with a high colour rendering index (CRI) of 94 was fabricated. Electronic supplementary information (ESI) available: Characterization methods, SEM and TEM images, fluorescence spectra and CIE coordinates of CDSP. See DOI: 10.1039/c5nr05637c

Colour calibration of a laboratory computer vision system for quality evaluation of pre-sliced hams.

PubMed

Valous, Nektarios A; Mendoza, Fernando; Sun, Da-Wen; Allen, Paul

2009-01-01

Due to the high variability and complex colour distribution in meats and meat products, the colour signal calibration of any computer vision system used for colour quality evaluations, represents an essential condition for objective and consistent analyses. This paper compares two methods for CIE colour characterization using a computer vision system (CVS) based on digital photography; namely the polynomial transform procedure and the transform proposed by the sRGB standard. Also, it presents a procedure for evaluating the colour appearance and presence of pores and fat-connective tissue on pre-sliced hams made from pork, turkey and chicken. Our results showed high precision, in colour matching, for device characterization when the polynomial transform was used to match the CIE tristimulus values in comparison with the sRGB standard approach as indicated by their ΔE(ab)(∗) values. The [3×20] polynomial transfer matrix yielded a modelling accuracy averaging below 2.2 ΔE(ab)(∗) units. Using the sRGB transform, high variability was appreciated among the computed ΔE(ab)(∗) (8.8±4.2). The calibrated laboratory CVS, implemented with a low-cost digital camera, exhibited reproducible colour signals in a wide range of colours capable of pinpointing regions-of-interest and allowed the extraction of quantitative information from the overall ham slice surface with high accuracy. The extracted colour and morphological features showed potential for characterizing the appearance of ham slice surfaces. CVS is a tool that can objectively specify colour and appearance properties of non-uniformly coloured commercial ham slices.

Colour-cueing in visual search.

PubMed

Laarni, J

2001-02-01

Several studies have shown that people can selectively attend to stimulus colour, e.g., in visual search, and that preknowledge of a target colour can improve response speed/accuracy. The purpose was to use a form-identification task to determine whether valid colour precues can produce benefits and invalid cues costs. The subject had to identify the orientation of a "T"-shaped element in a ring of randomly-oriented "L"s when either two or four of the elements were differently coloured. Contrary to Moore and Egeth's (1998) recent findings, colour-based attention did affect performance under data-limited conditions: Colour cues produced benefits when processing load was high; when the load was reduced, they incurred only costs. Surprisingly, a valid colour cue succeeded in improving performance in the high-load condition even when its validity was reduced to the chance level. Overall, the results suggest that knowledge of a target colour does not facilitate the processing of the target, but makes it possible to prioritize it.

Influence of skin colour on diagnostic accuracy of the jaundice meter JM 103 in newborns.

PubMed

Samiee-Zafarghandy, S; Feberova, J; Williams, K; Yasseen, A S; Perkins, S L; Lemyre, B

2014-11-01

To assess the diagnostic accuracy of the JM 103 as a screening tool for neonatal jaundice and explore differential effects based on skin colour. We prospectively compared the transcutaneous bilirubin (TcB) and serum bilirubin (TSB) measurements of newborns over a 3 month-period. Skin colour was assigned via reference colour swatches. Diagnostic measures of the TcB/TSB comparison were made and clinically relevant TcB cut-off values were determined for each skin colour group. 451 infants (51 light, 326 medium and 74 dark skin colour) were recruited. The association between TcB and TSB was high for all skin colours (rs>0.9). The Bland-Altman analysis showed an absolute mean difference between the two measures of 13.3±26.4 µmol/L with broad limits of agreement (-39.4-66.0 µmol/L), with TcB underestimating TSB in light and medium skin colours and overestimating in dark skin colour. Diagnostic measures were also consistently high across skin colours, with no clinically significant differences observed. The JM 103 is a useful screening tool to identify infants in need of serum bilirubin, regardless of skin colour. The effect of skin colour on the accuracy of this device at high levels of serum bilirubin could not be assessed fully due to small numbers in the light and dark groups. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Temperature, but Not Available Energy, Affects the Expression of a Sexually Selected Ultraviolet (UV) Colour Trait in Male European Green Lizards

PubMed Central

Bajer, Katalin; Molnár, Orsolya; Török, János; Herczeg, Gábor

2012-01-01

Background Colour signals are widely used in intraspecific communication and often linked to individual fitness. The development of some pigment-based (e.g. carotenoids) colours is often environment-dependent and costly for the signaller, however, for structural colours (e.g. ultraviolet [UV]) this topic is poorly understood, especially in terrestrial ectothermic vertebrates. Methodology/Principal Findings In a factorial experiment, we studied how available energy and time at elevated body temperature affects the annual expression of the nuptial throat colour patch in male European green lizards (Lacerta viridis) after hibernation and before mating season. In this species, there is a female preference for males with high throat UV reflectance, and males with high UV reflectance are more likely to win fights. We found that (i) while food shortage decreased lizards' body condition, it did not affect colour development, and (ii) the available time for maintaining high body temperature affected the development of UV colour without affecting body condition or other colour traits. Conclusions/Significance Our results demonstrate that the expression of a sexually selected structural colour signal depends on the time at elevated body temperature affecting physiological performance but not on available energy gained from food per se in an ectothermic vertebrate. We suggest that the effect of high ambient temperature on UV colour in male L. viridis makes it an honest signal, because success in acquiring thermally favourable territories and/or effective behavioural thermoregulation can both be linked to individual quality. PMID:22479611

Scalable, full-colour and controllable chromotropic plasmonic printing

PubMed Central

Xue, Jiancai; Zhou, Zhang-Kai; Wei, Zhiqiang; Su, Rongbin; Lai, Juan; Li, Juntao; Li, Chao; Zhang, Tengwei; Wang, Xue-Hua

2015-01-01

Plasmonic colour printing has drawn wide attention as a promising candidate for the next-generation colour-printing technology. However, an efficient approach to realize full colour and scalable fabrication is still lacking, which prevents plasmonic colour printing from practical applications. Here we present a scalable and full-colour plasmonic printing approach by combining conjugate twin-phase modulation with a plasmonic broadband absorber. More importantly, our approach also demonstrates controllable chromotropic capability, that is, the ability of reversible colour transformations. This chromotropic capability affords enormous potentials in building functionalized prints for anticounterfeiting, special label, and high-density data encryption storage. With such excellent performances in functional colour applications, this colour-printing approach could pave the way for plasmonic colour printing in real-world commercial utilization. PMID:26567803

Scalable, full-colour and controllable chromotropic plasmonic printing.

PubMed

Xue, Jiancai; Zhou, Zhang-Kai; Wei, Zhiqiang; Su, Rongbin; Lai, Juan; Li, Juntao; Li, Chao; Zhang, Tengwei; Wang, Xue-Hua

2015-11-16

Plasmonic colour printing has drawn wide attention as a promising candidate for the next-generation colour-printing technology. However, an efficient approach to realize full colour and scalable fabrication is still lacking, which prevents plasmonic colour printing from practical applications. Here we present a scalable and full-colour plasmonic printing approach by combining conjugate twin-phase modulation with a plasmonic broadband absorber. More importantly, our approach also demonstrates controllable chromotropic capability, that is, the ability of reversible colour transformations. This chromotropic capability affords enormous potentials in building functionalized prints for anticounterfeiting, special label, and high-density data encryption storage. With such excellent performances in functional colour applications, this colour-printing approach could pave the way for plasmonic colour printing in real-world commercial utilization.

Dynamic plasmonic colour display

NASA Astrophysics Data System (ADS)

Duan, Xiaoyang; Kamin, Simon; Liu, Na

2017-02-01

Plasmonic colour printing based on engineered metasurfaces has revolutionized colour display science due to its unprecedented subwavelength resolution and high-density optical data storage. However, advanced plasmonic displays with novel functionalities including dynamic multicolour printing, animations, and highly secure encryption have remained in their infancy. Here we demonstrate a dynamic plasmonic colour display technique that enables all the aforementioned functionalities using catalytic magnesium metasurfaces. Controlled hydrogenation and dehydrogenation of the constituent magnesium nanoparticles, which serve as dynamic pixels, allow for plasmonic colour printing, tuning, erasing and restoration of colour. Different dynamic pixels feature distinct colour transformation kinetics, enabling plasmonic animations. Through smart material processing, information encoded on selected pixels, which are indiscernible to both optical and scanning electron microscopies, can only be read out using hydrogen as a decoding key, suggesting a new generation of information encryption and anti-counterfeiting applications.

Dynamic plasmonic colour display.

PubMed

Duan, Xiaoyang; Kamin, Simon; Liu, Na

2017-02-24

Plasmonic colour printing based on engineered metasurfaces has revolutionized colour display science due to its unprecedented subwavelength resolution and high-density optical data storage. However, advanced plasmonic displays with novel functionalities including dynamic multicolour printing, animations, and highly secure encryption have remained in their infancy. Here we demonstrate a dynamic plasmonic colour display technique that enables all the aforementioned functionalities using catalytic magnesium metasurfaces. Controlled hydrogenation and dehydrogenation of the constituent magnesium nanoparticles, which serve as dynamic pixels, allow for plasmonic colour printing, tuning, erasing and restoration of colour. Different dynamic pixels feature distinct colour transformation kinetics, enabling plasmonic animations. Through smart material processing, information encoded on selected pixels, which are indiscernible to both optical and scanning electron microscopies, can only be read out using hydrogen as a decoding key, suggesting a new generation of information encryption and anti-counterfeiting applications.

Dynamic plasmonic colour display

PubMed Central

Duan, Xiaoyang; Kamin, Simon; Liu, Na

2017-01-01

Plasmonic colour printing based on engineered metasurfaces has revolutionized colour display science due to its unprecedented subwavelength resolution and high-density optical data storage. However, advanced plasmonic displays with novel functionalities including dynamic multicolour printing, animations, and highly secure encryption have remained in their infancy. Here we demonstrate a dynamic plasmonic colour display technique that enables all the aforementioned functionalities using catalytic magnesium metasurfaces. Controlled hydrogenation and dehydrogenation of the constituent magnesium nanoparticles, which serve as dynamic pixels, allow for plasmonic colour printing, tuning, erasing and restoration of colour. Different dynamic pixels feature distinct colour transformation kinetics, enabling plasmonic animations. Through smart material processing, information encoded on selected pixels, which are indiscernible to both optical and scanning electron microscopies, can only be read out using hydrogen as a decoding key, suggesting a new generation of information encryption and anti-counterfeiting applications. PMID:28232722

Object knowledge modulates colour appearance.

PubMed

Witzel, Christoph; Valkova, Hanna; Hansen, Thorsten; Gegenfurtner, Karl R

2011-01-01

We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis.

Object knowledge modulates colour appearance

PubMed Central

Witzel, Christoph; Valkova, Hanna; Hansen, Thorsten; Gegenfurtner, Karl R

2011-01-01

We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis. PMID:23145224

New design opportunities with OVI

NASA Astrophysics Data System (ADS)

Bleikolm, Anton F.

1998-04-01

Optically Variable Ink (OVITM) chosen for its unique colour shifting properties is applied to the currencies of more than 50 countries. An significant colour difference at viewing angles of 90 degrees and 30 degrees respectively makes colour copying impossible. New manufacturing techniques for the interference pigment (OVP) provide ever better cost/performance ratios. Screen printing presses newly available on the market guarantee production speeds of 8000 sheets/hour or 130 meters/minute in the case of web printing, perfectly in line with the traditional equipment for manufacturing of currency. Specifically developed ink formulations allow UV-curing at high speed or oxidative drying to create highly mechanically and chemically resistant colour shifting prints. The unique colour shifting characteristics together with overprinting in intaglio give design opportunities providing the best protection against colour copying or commercial reprint. Specific designs of OVP together with high security ingredients allow the formulation of machine readable optically variable inks useful for the authentication and sorting of documents.

Dual mode operation, highly selective nanohole array-based plasmonic colour filters

NASA Astrophysics Data System (ADS)

Fouladi Mahani, Fatemeh; Mokhtari, Arash; Mehran, Mahdiyeh

2017-09-01

Taking advantage of nanostructured metal films as plasmonic colour filters (PCFs) has been evolved remarkably as an alternative to the conventional technologies of chemical colour filtering. However, most of the proposed PCFs depict a poor colour purity focusing on generating either the additive or subtractive colours. In this paper, we present dual mode operation PCFs employing an opaque aluminium film patterned with sub-wavelength holes. Subtractive colours like cyan, magenta, and yellow are the results of reflection mode of these filters yielding optical efficiencies as high as 70%-80% and full width at half maximum of the stop-bands up to 40-50 nm. The colour selectivity of the transmission mode for the additive colours is also significant due to their enhanced performance through the utilization of a relatively thick aluminium film in contact with a modified dielectric environment. These filters provide a simple design with one-step lithography in addition to compatibility with the conventional CMOS processes. Moreover, they are polarization insensitive due to their symmetric geometry. A complete palette of pure subtractive and additive colours has been realized with potential applications, such as multispectral imaging, CMOS image sensors, displays, and colour printing.

Dual mode operation, highly selective nanohole array-based plasmonic colour filters.

PubMed

Mahani, Fatemeh Fouladi; Mokhtari, Arash; Mehran, Mahdiyeh

2017-09-20

Taking advantage of nanostructured metal films as plasmonic colour filters (PCFs) has been evolved remarkably as an alternative to the conventional technologies of chemical colour filtering. However, most of the proposed PCFs depict a poor colour purity focusing on generating either the additive or subtractive colours. In this paper, we present dual mode operation PCFs employing an opaque aluminium film patterned with sub-wavelength holes. Subtractive colours like cyan, magenta, and yellow are the results of reflection mode of these filters yielding optical efficiencies as high as 70%-80% and full width at half maximum of the stop-bands up to 40-50 nm. The colour selectivity of the transmission mode for the additive colours is also significant due to their enhanced performance through the utilization of a relatively thick aluminium film in contact with a modified dielectric environment. These filters provide a simple design with one-step lithography in addition to compatibility with the conventional CMOS processes. Moreover, they are polarization insensitive due to their symmetric geometry. A complete palette of pure subtractive and additive colours has been realized with potential applications, such as multispectral imaging, CMOS image sensors, displays, and colour printing.

Consumer exposures to anthocyanins from colour additives, colouring foodstuffs and from natural occurrence in foods.

PubMed

Tennant, David R; Klingenberg, Andreas

2016-06-01

Anthocyanins are responsible for the red/blue colour of grapes, currants, and other fruits and vegetables. They may also be extracted for use as colour additives (E163) or concentrated for use as colouring foods. Consumer exposures have been assessed using data on natural occurrence, use levels and frequencies from food manufacturers and European food consumption data. Intakes from natural occurrence can be up to 4 mg kg bw(-1) day(-1) at the mean and up to 17 mg kg bw(-1) day(-1) for children who are high level consumers of red/black berries and small fruits. High-level intakes for children from food colour and colouring food applications lie in the range 0.3-6.3 mg kg bw(-1) day(-1) and for adults at 0.6-2.8 mg kg bw(-1) day(-1). Exposures from food colour use and colouring foods separately or combined are therefore lower than those from natural occurrence in foods.

Raman identification of cuneiform tablet pigments: emphasis and colour technology in ancient Mesopotamian mid-third millennium.

PubMed

Chiriu, Daniele; Ricci, Pier Carlo; Carbonaro, Carlo Maria; Nadali, Davide; Polcaro, Andrea; Collins, Paul

2017-03-01

Cuneiform tablets tell the life and culture of Sumerian people in a sort of black and white tale because of the binary engraving technique. A leading question arises: did Mesopotamian people apply some kind of colour to decorate their tablets or to put emphasis on selected words? Some administrative and literary Sumerian cuneiform tablets of mid-third Millennium B.C. from the site of Kish (central Mesopotamia, modern Iraq) were dug up in twentieth-century and stored at the Ashmolean Museum of the Oxford University. Non-destructive micro-Raman spectroscopy is a powerful technique to detect the presence of residual pigments eventually applied to the engraving signs. Yellow, orange, red and white pigments have been detected and a possible identification has been proposed in this work. In particular yellow pigments are identified as Crocoite (PbCrO 4 ), Lead stannate (Pb 2 SnO 4 ); red pigments - hematite (Fe 2 O 3 ) and cuprite (Cu 2 O); White pigments - Lead carbonate (PbCO 3 ), calcium phosphate (Ca 3 (PO 4 ) 2 ), titanium dioxide (TiO 2 ), gypsum (CaSO 4 .2H 2 O); orange pigment a composition of red and yellow compounds. These results suggest that Sumerian people invented a new editorial style, to overcome the binary logic of engraving process and catch the reader's eye by decorating cuneiform tablets. Finally, the coloured rendering of the tablet in their original view is proposed.

Printing colour at the optical diffraction limit.

PubMed

Kumar, Karthik; Duan, Huigao; Hegde, Ravi S; Koh, Samuel C W; Wei, Jennifer N; Yang, Joel K W

2012-09-01

The highest possible resolution for printed colour images is determined by the diffraction limit of visible light. To achieve this limit, individual colour elements (or pixels) with a pitch of 250 nm are required, translating into printed images at a resolution of ∼100,000 dots per inch (d.p.i.). However, methods for dispensing multiple colourants or fabricating structural colour through plasmonic structures have insufficient resolution and limited scalability. Here, we present a non-colourant method that achieves bright-field colour prints with resolutions up to the optical diffraction limit. Colour information is encoded in the dimensional parameters of metal nanostructures, so that tuning their plasmon resonance determines the colours of the individual pixels. Our colour-mapping strategy produces images with both sharp colour changes and fine tonal variations, is amenable to large-volume colour printing via nanoimprint lithography, and could be useful in making microimages for security, steganography, nanoscale optical filters and high-density spectrally encoded optical data storage.

Structural colour printing from a reusable generic nanosubstrate masked for the target image

NASA Astrophysics Data System (ADS)

Rezaei, M.; Jiang, H.; Kaminska, B.

2016-02-01

Structural colour printing has advantages over traditional pigment-based colour printing. However, the high fabrication cost has hindered its applications in printing large-area images because each image requires patterning structural pixels in nanoscale resolution. In this work, we present a novel strategy to print structural colour images from a pixelated substrate which is called a nanosubstrate. The nanosubstrate is fabricated only once using nanofabrication tools and can be reused for printing a large quantity of structural colour images. It contains closely packed arrays of nanostructures from which red, green, blue and infrared structural pixels can be imprinted. To print a target colour image, the nanosubstrate is first covered with a mask layer to block all the structural pixels. The mask layer is subsequently patterned according to the target colour image to make apertures of controllable sizes on top of the wanted primary colour pixels. The masked nanosubstrate is then used as a stamp to imprint the colour image onto a separate substrate surface using nanoimprint lithography. Different visual colours are achieved by properly mixing the red, green and blue primary colours into appropriate ratios controlled by the aperture sizes on the patterned mask layer. Such a strategy significantly reduces the cost and complexity of printing a structural colour image from lengthy nanoscale patterning into high throughput micro-patterning and makes it possible to apply structural colour printing in personalized security features and data storage. In this paper, nanocone array grating pixels were used as the structural pixels and the nanosubstrate contains structures to imprint the nanocone arrays. Laser lithography was implemented to pattern the mask layer with submicron resolution. The optical properties of the nanocone array gratings are studied in detail. Multiple printed structural colour images with embedded covert information are demonstrated.

Predicting the long-term durability of hemp-lime renders in inland and coastal areas using Mediterranean, Tropical and Semi-arid climatic simulations.

PubMed

Arizzi, Anna; Viles, Heather; Martín-Sanchez, Inés; Cultrone, Giuseppe

2016-01-15

Hemp-based composites are eco-friendly building materials as they improve energy efficiency in buildings and entail low waste production and pollutant emissions during their manufacturing process. Nevertheless, the organic nature of hemp enhances the bio-receptivity of the material, with likely negative consequences for its long-term performance in the building. The main purpose of this study was to study the response at macro- and micro-scale of hemp-lime renders subjected to weathering simulations in an environmental cabinet (one year was condensed in twelve days), so as to predict their long-term durability in coastal and inland areas with Mediterranean, Tropical and Semi-arid climates, also in relation with the lime type used. The simulated climatic conditions caused almost unnoticeable mass, volume and colour changes in hemp-lime renders. No efflorescence or physical breakdown was detected in samples subjected to NaCl, because the salt mainly precipitates on the surface of samples and is washed away by the rain. Although there was no visible microbial colonisation, alkaliphilic fungi (mainly Penicillium and Aspergillus) and bacteria (mainly Bacillus and Micrococcus) were isolated in all samples. Microbial growth and diversification were higher under Tropical climate, due to heavier rainfall. The influence of the bacterial activity on the hardening of samples has also been discussed here and related with the formation and stabilisation of vaterite in hemp-lime mixes. This study has demonstrated that hemp-lime renders show good durability towards a wide range of environmental conditions and factors. However, it might be useful to take some specific preventive and maintenance measures to reduce the bio-receptivity of this material, thus ensuring a longer durability on site. Copyright © 2015 Elsevier B.V. All rights reserved.

Selective interference reveals dissociation between memory for location and colour.

PubMed

Vuontela, V; Rämä, P; Raninen, A; Aronen, H J; Carlson, S

1999-08-02

The aim was to study whether there is indication of a dissociation in processing of visuospatial and colour information in working memory in humans. Experimental subjects performed visuospatial and colour n-back tasks with and without visuospatial and colour distractive stimuli presented in the middle of the delay period to specifically affect mnemonic processing of task-related information. In the high memory-load condition, the visuospatial, but not the colour, task was selectively disrupted by visuospatial but not colour distractors. When subvocal rehearsal of the memoranda in the colour task was prevented by articulatory suppression; colour task performance was also selectively disrupted by distractors qualitatively similar to the memoranda. The results support the suggestion that visual working memory for location is processed separate from that for colour.

Reproducing the old masters: applying colour mixing and painting methodologies to inkjet printing

NASA Astrophysics Data System (ADS)

Olen, Melissa; Padfield, Joseph; Parraman, Carinna

2014-01-01

This research investigates multi-channel inkjet printing methods, which deviate from standard colour management workflows by reflecting on art historical processes, including the construction of colour in old master works, to reproduce specific colour pigment mixes in print. This is approached by incorporating artist colour mixing principles relevant to traditional art making processes through direct n-channel printing and the implementation of multiple pass printing. By demanding specific ink colourants to be employed in print, as well as the application of mixing colour though layering, we can mimic the effects of the traditional processes. These printing methods also generate colour through a variety of colour mixtures that may not have been employed or achieved by the printer driver. The objective of this research is to explore colour mixing and layering techniques in the printing of inkjet reproductions of original artworks that will maintain subtle colour transitions in dark shadow regions. While these colours are lost in traditional inkjet reproduction, by using direct n-channel editing capabilities to reproduce a painted original with high dynamic range we can improve colour variation in the shadow regions.

Bumblebees (Bombus terrestris) and honeybees (Apis mellifera) prefer similar colours of higher spectral purity over trained colours.

PubMed

Rohde, Katja; Papiorek, Sarah; Lunau, Klaus

2013-03-01

Differences in the concentration of pigments as well as their composition and spatial arrangement cause intraspecific variation in the spectral signature of flowers. Known colour preferences and requirements for flower-constant foraging bees predict different responses to colour variability. In experimental settings, we simulated small variations of unicoloured petals and variations in the spatial arrangement of colours within tricoloured petals using artificial flowers and studied their impact on the colour choices of bumblebees and honeybees. Workers were trained to artificial flowers of a given colour and then given the simultaneous choice between three test colours: either the training colour, one colour of lower and one of higher spectral purity, or the training colour, one colour of lower and one of higher dominant wavelength; in all cases the perceptual contrast between the training colour and the additional test colours was similarly small. Bees preferred artificial test flowers which resembled the training colour with the exception that they preferred test colours with higher spectral purity over trained colours. Testing the behaviour of bees at artificial flowers displaying a centripetal or centrifugal arrangement of three equally sized colours with small differences in spectral purity, bees did not prefer any type of artificial flowers, but preferentially choose the most spectrally pure area for the first antenna contact at both types of artificial flowers. Our results indicate that innate preferences for flower colours of high spectral purity in pollinators might exert selective pressure on the evolution of flower colours.

Colour and pattern change against visually heterogeneous backgrounds in the tree frog Hyla japonica.

PubMed

Kang, Changku; Kim, Ye Eun; Jang, Yikweon

2016-03-02

Colour change in animals can be adaptive phenotypic plasticity in heterogeneous environments. Camouflage through background colour matching has been considered a primary force that drives the evolution of colour changing ability. However, the mechanism to which animals change their colour and patterns under visually heterogeneous backgrounds (i.e. consisting of more than one colour) has only been identified in limited taxa. Here, we investigated the colour change process of the Japanese tree frog (Hyla japonica) against patterned backgrounds and elucidated how the expression of dorsal patterns changes against various achromatic/chromatic backgrounds with/without patterns. Our main findings are i) frogs primarily responded to the achromatic differences in background, ii) their contrasting dorsal patterns were conditionally expressed dependent on the brightness of backgrounds, iii) against mixed coloured background, frogs adopted intermediate forms between two colours. Using predator (avian and snake) vision models, we determined that colour differences against different backgrounds yielded perceptible changes in dorsal colours. We also found substantial individual variation in colour changing ability and the levels of dorsal pattern expression between individuals. We discuss the possibility of correlational selection on colour changing ability and resting behaviour that maintains the high variation in colour changing ability within population.

Automated colour identification in melanocytic lesions.

PubMed

Sabbaghi, S; Aldeen, M; Garnavi, R; Varigos, G; Doliantis, C; Nicolopoulos, J

2015-08-01

Colour information plays an important role in classifying skin lesion. However, colour identification by dermatologists can be very subjective, leading to cases of misdiagnosis. Therefore, a computer-assisted system for quantitative colour identification is highly desirable for dermatologists to use. Although numerous colour detection systems have been developed, few studies have focused on imitating the human visual perception of colours in melanoma application. In this paper we propose a new methodology based on QuadTree decomposition technique for automatic colour identification in dermoscopy images. Our approach mimics the human perception of lesion colours. The proposed method is trained on a set of 47 images from NIH dataset and applied to a test set of 190 skin lesions obtained from PH2 dataset. The results of our proposed method are compared with a recently reported colour identification method using the same dataset. The effectiveness of our method in detecting colours in dermoscopy images is vindicated by obtaining approximately 93% accuracy when the CIELab1 colour space is used.

Highly polymorphic colour vision in a New World monkey with red facial skin, the bald uakari (Cacajao calvus).

PubMed

Corso, Josmael; Bowler, Mark; Heymann, Eckhard W; Roos, Christian; Mundy, Nicholas I

2016-04-13

Colour vision is highly variable in New World monkeys (NWMs). Evidence for the adaptive basis of colour vision in this group has largely centred on environmental features such as foraging benefits for differently coloured foods or predator detection, whereas selection on colour vision for sociosexual communication is an alternative hypothesis that has received little attention. The colour vision of uakaris (Cacajao) is of particular interest because these monkeys have the most dramatic red facial skin of any primate, as well as a unique fission/fusion social system and a specialist diet of seeds. Here, we investigate colour vision in a wild population of the bald uakari,C. calvus, by genotyping the X-linked opsin locus. We document the presence of a polymorphic colour vision system with an unprecedented number of functional alleles (six), including a novel allele with a predicted maximum spectral sensitivity of 555 nm. This supports the presence of strong balancing selection on different alleles at this locus. We consider different hypotheses to explain this selection. One possibility is that trichromacy functions in sexual selection, enabling females to choose high-quality males on the basis of red facial coloration. In support of this, there is some evidence that health affects facial coloration in uakaris, as well as a high prevalence of blood-borne parasitism in wild uakari populations. Alternatively, the low proportion of heterozygous female trichromats in the population may indicate selection on different dichromatic phenotypes, which might be related to cryptic food coloration. We have uncovered unexpected diversity in the last major lineage of NWMs to be assayed for colour vision, which will provide an interesting system to dissect adaptation of polymorphic trichromacy. © 2016 The Author(s).

Bees' subtle colour preferences: how bees respond to small changes in pigment concentration

NASA Astrophysics Data System (ADS)

Papiorek, Sarah; Rohde, Katja; Lunau, Klaus

2013-07-01

Variability in flower colour of animal-pollinated plants is common and caused, inter alia, by inter-individual differences in pigment concentrations. If and how pollinators, especially bees, respond to these small differences in pigment concentration is not known, but it is likely that flower colour variability impacts the choice behaviour of all flower visitors that exhibit innate and learned colour preferences. In behavioural experiments, we simulated varying pigment concentrations and studied its impact on the colour choices of bumblebees and honeybees. Individual bees were trained to artificial flowers having a specific concentration of a pigment, i.e. Acridine Orange or Aniline Blue, and then given the simultaneous choice between three test colours including the training colour, one colour of lower and one colour of higher pigment concentration. For each pigment, two set-ups were provided, covering the range of low to middle and the range of middle to high pigment concentrations. Despite the small bee-subjective perceptual contrasts between the tested stimuli and regardless of training towards medium concentrations, bees preferred neither the training stimuli nor the stimuli offering the highest pigment concentration but more often chose those stimuli offering the highest spectral purity and the highest chromatic contrast against the background. Overall, this study suggests that bees choose an intermediate pigment concentration due to its optimal conspicuousness. It is concluded that the spontaneous preferences of bees for flower colours of high spectral purity might exert selective pressure on the evolution of floral colours and of flower pigmentation.

Individual quality explains association between plumage colouration, arrival dates and mate acquisition in yellow warblers (Setophaga petechia).

PubMed

Jones, Teri B; Drake, Anna; Green, David J

2014-05-07

In many bird species colour traits influence social dominance and breeding success. In our study we first evaluated whether the colour of the basic plumage (tail feathers grown at the end of the breeding season), that provides an index of individual quality, influenced winter habitat use by yellow warblers. We then evaluated whether winter habitat use (inferred using δ13C and δ15N signatures of winter grown greater-coverts) influenced alternate plumage colouration, after controlling for individual quality using basic plumage colouration. Finally, we investigated whether basic and alternate plumage colouration influenced arrival dates, mate acquisition, breeding phenology and reproductive success of yellow warblers breeding in southern (Revelstoke, B.C.) and arctic (Inuvik, N.W.T.) Canada. The colour (chroma and hue) of tail feathers, grown on the breeding grounds, was not related to subsequent winter habitat use. Greater covert and tail feather colour (chroma and hue) were correlated, suggesting genetics and/or individual quality played a role in pigment deposition. After controlling for individual difference in tail colour, δ13C values did not explain any variation in greater covert colour, but birds with high δ15N signatures had greater coverts with higher chroma. Male arrival dates varied with tail chroma in Revelstoke and tail hue in Inuvik. Males that arrived early paired with older and/or more colourful mates that initiated clutches earlier, and at one site (Revelstoke) were more likely to fledge young. In addition, in Revelstoke (but not Inuvik) males with high tail hue also acquired more colourful mates. In contrast, after controlling for individual differences in tail colour, greater covert colour did not affect male arrival date, the quality of the mate obtained or reproductive success in either population. Our results suggest that plumage colour effects on breeding phenology and mate acquisition result from differences in the intrinsic quality of individuals rather than a carry-over effect of winter habitat use.

Individual quality explains association between plumage colouration, arrival dates and mate acquisition in yellow warblers (Setophaga petechia)

PubMed Central

2014-01-01

Background In many bird species colour traits influence social dominance and breeding success. In our study we first evaluated whether the colour of the basic plumage (tail feathers grown at the end of the breeding season), that provides an index of individual quality, influenced winter habitat use by yellow warblers. We then evaluated whether winter habitat use (inferred using δ13C and δ15N signatures of winter grown greater-coverts) influenced alternate plumage colouration, after controlling for individual quality using basic plumage colouration. Finally, we investigated whether basic and alternate plumage colouration influenced arrival dates, mate acquisition, breeding phenology and reproductive success of yellow warblers breeding in southern (Revelstoke, B.C.) and arctic (Inuvik, N.W.T.) Canada. Results The colour (chroma and hue) of tail feathers, grown on the breeding grounds, was not related to subsequent winter habitat use. Greater covert and tail feather colour (chroma and hue) were correlated, suggesting genetics and/or individual quality played a role in pigment deposition. After controlling for individual difference in tail colour, δ13C values did not explain any variation in greater covert colour, but birds with high δ15N signatures had greater coverts with higher chroma. Male arrival dates varied with tail chroma in Revelstoke and tail hue in Inuvik. Males that arrived early paired with older and/or more colourful mates that initiated clutches earlier, and at one site (Revelstoke) were more likely to fledge young. In addition, in Revelstoke (but not Inuvik) males with high tail hue also acquired more colourful mates. In contrast, after controlling for individual differences in tail colour, greater covert colour did not affect male arrival date, the quality of the mate obtained or reproductive success in either population. Conclusions Our results suggest that plumage colour effects on breeding phenology and mate acquisition result from differences in the intrinsic quality of individuals rather than a carry-over effect of winter habitat use. PMID:24886073

Human hair pigmentation--biological aspects.

PubMed

Tobin, D J

2008-08-01

Skin and hair colour contribute significantly to our overall visual appearance and to social/sexual communication. Despite their shared origins in the embryologic neural crest, the hair follicle and epidermal pigmentary units occupy distinct, although open, cutaneous compartments. They can be distinguished principally on the basis of the former's stringent coupling to the hair growth cycle compared with the latter's continuous melanogenesis. The biosynthesis of melanin and its subsequent transfer from melanocyte to hair bulb keratinocytes depend on the availability of melanin precursors and on a raft of signal transduction pathways that are both highly complex and commonly redundant. These signalling pathways can be both dependent and independent of receptors, act through auto-, para- or intracrine mechanisms and can be modified by hormonal signals. Despite many shared features, follicular melanocytes appear to be more sensitive than epidermal melanocytes to ageing influences. This can be seen most dramatically in hair greying/canities and this is likely to reflect significant differences in the epidermal and follicular microenvironments. The hair follicle pigmentary unit may also serve as an important environmental sensor, whereby hair pigment contributes to the rapid excretion of heavy metals, chemicals and toxins from the body by their selective binding to melanin; rendering the hair fibre a useful barometer of exposures. The recent availability of advanced cell culture methodologies for isolated hair follicle melanocytes and for intact anagen hair follicle organ culture should provide the research tools necessary to elucidate the regulatory mechanisms of hair follicle pigmentation. In the longer term, it may be feasible to develop hair colour modifiers of a biological nature to accompany those based on chemicals.

Pollinators show flower colour preferences but flowers with similar colours do not attract similar pollinators

PubMed Central

Reverté, Sara; Retana, Javier; Gómez, José M.; Bosch, Jordi

2016-01-01

Background and aims Colour is one of the main floral traits used by pollinators to locate flowers. Although pollinators show innate colour preferences, the view that the colour of a flower may be considered an important predictor of its main pollinators is highly controversial because flower choice is highly context-dependent, and initial innate preferences may be overridden by subsequent associative learning. Our objective is to establish whether there is a relationship between flower colour and pollinator composition in natural communities. Methods We measured the flower reflectance spectrum and pollinator composition in four plant communities (85 plant species represented by 109 populations, and 32 305 plant–pollinator interactions in total). Pollinators were divided into six taxonomic groups: bees, ants, wasps, coleopterans, dipterans and lepidopterans. Key Results We found consistent associations between pollinator groups and certain colours. These associations matched innate preferences experimentally established for several pollinators and predictions of the pollination syndrome theory. However, flowers with similar colours did not attract similar pollinator assemblages. Conclusions The explanation for this paradoxical result is that most flower species are pollination generalists. We conclude that although pollinator colour preferences seem to condition plant–pollinator interactions, the selective force behind these preferences has not been strong enough to mediate the appearance and maintenance of tight colour-based plant–pollinator associations. PMID:27325897

Conditioning with compound stimuli in Drosophila melanogaster in the flight simulator.

PubMed

Brembs, B; Heisenberg, M

2001-08-01

Short-term memory in Drosophila melanogaster operant visual learning in the flight simulator is explored using patterns and colours as a compound stimulus. Presented together during training, the two stimuli accrue the same associative strength whether or not a prior training phase rendered one of the two stimuli a stronger predictor for the reinforcer than the other (no blocking). This result adds Drosophila to the list of other invertebrates that do not exhibit the robust vertebrate blocking phenomenon. Other forms of higher-order learning, however, were detected: a solid sensory preconditioning and a small second-order conditioning effect imply that associations between the two stimuli can be formed, even if the compound is not reinforced.

Protaeolidiella atra Baba, 1955 versus Pleurolidia juliae Burn, 1966: One or two species?

NASA Astrophysics Data System (ADS)

Carmona, Leila; Pola, Marta; Gosliner, Terrence M.; Cervera, Juan Lucas

2015-06-01

Protaeolidiella atra Baba, 1955 and Pleurolidia juliae Burn, 1966 are two species traditionally regarded as the members of Aeolidiidae but recently attributed to Facelinidae. Because of their apparent similarities, Rudman (J Molluscan Stud 56:505-514, 1990) rendered P. juliae as a junior synonym of P. atra. In this paper, we conducted a review of both species and completed their descriptions with new data regarding the anatomy of the reproductive system . P. atra and P. juliae have differences in their colouration, number of cerata and characteristics of their reproductive system. Based on these differences, we conclude that these species are not conspecific and should be regarded as distinct taxa.

Assessment of colour changes during storage of elderberry juice concentrate solutions using the optimization method.

PubMed

Walkowiak-Tomczak, Dorota; Czapski, Janusz; Młynarczyk, Karolina

2016-01-01

Elderberries are a source of dietary supplements and bioactive compounds, such as anthocyanins. These dyes are used in food technology. The aim of the study was to assess the changes in colour parameters, anthocyanin contents and sensory attributes in solutions of elderberry juice concentrates during storage in a model system and to determine predictability of sensory attributes of colour in solutions based on regression equations using the response surface methodology. The experiment was carried out according to the 3-level factorial design for three factors. Independent variables included pH, storage time and temperature. Dependent variables were assumed to be the components and colour parameters in the CIE L*a*b* system, pigment contents and sensory attributes. Changes in colour components X, Y, Z and colour parameters L*, a*, b*, C* and h* were most dependent on pH values. Colour lightness L* and tone h* increased with an increase in experimental factors, while the share of the red colour a* and colour saturation C* decreased. The greatest effect on the anthocyanin concentration was recorded for storage time. Sensory attributes deteriorated during storage. The highest correlation coefficients were found between the value of colour tone h* and anthocyanin contents in relation to the assessment of the naturalness and desirability of colour. A high goodness-of-fit of the model to data and high values of R2 for regression equations were obtained for all responses. The response surface method facilitates optimization of experimental factor values in order to obtain a specific attribute of the product, but not in all cases of the experiment. Within the tested range of factors, it is possible to predict changes in anthocyanin content and the sensory attributes of elderberry juice concentrate solutions as food dye, on the basis of the lack of a fit test. The highest stability of dyes and colour of elderberry solutions was found in the samples at pH 3.0, which confirms the advisability of using an anthocyanin preparation to shape the colour of high-acidity food products, such as fruit fillings, beverages,desserts.

Estimates of dietary exposure of children to artificial food colours in Kuwait.

PubMed

Husain, A; Sawaya, W; Al-Omair, A; Al-Zenki, S; Al-Amiri, H; Ahmed, N; Al-Sinan, M

2006-03-01

To assess the intake of artificial food colour additives by 5-14-year-old children in the State of Kuwait, a 24-h dietary recall was conducted twice on 3141 male and female Kuwaiti and non-Kuwaiti children from 58 schools. The determination of colour additives in 344 foods items consumed was performed using high-performance liquid chromatography with diode array detector. A comparison with the Food and Agriculture Organization and World Health Organization acceptable daily intakes (ADIs) was undertaken to evaluate the potential risk associated with the consumption of artificial colour additives by children in Kuwait. The results indicated that out of nine permitted colours, four exceeded their ADIs by factors of 2-8: tartrazine, sunset yellow, carmoisine and allura red. Further, follow-up studies to provide insight into potential adverse health effects associated with the high intakes of these artificial colour additives on the test population are warranted.

Cow biological type affects ground beef colour stability.

PubMed

Raines, Christopher R; Hunt, Melvin C; Unruh, John A

2009-12-01

To determine the effects of cow biological type on colour stability of ground beef, M. semimembranosus from beef-type (BSM) and dairy-type (DSM) cows was obtained 5d postmortem. Three blends (100% BSM, 50% BSM+50% DSM, 100% DSM) were adjusted to 90% and 80% lean points using either young beef trim (YBT) or beef cow trim (BCT), then packaged in high oxygen (High-O(2); 80% O(2)) modified atmosphere (MAP). The BSM+YBT patties had the brightest colour initially, but discoloured rapidly. Although DSM+BCT patties had the darkest colour initially, they discoloured least during display. Metmyoglobin reducing ability of ground DSM was up to fivefold greater than ground BSM, and TBARS values of BSM was twofold greater than DSM by the end of display (4d). Though initially darker than beef cow lean, dairy cow lean has a longer display colour life and may be advantageous to retailers using High-O(2) MAP.

The colour of fitness: plumage coloration and lifetime reproductive success in the tawny owl

PubMed Central

Brommer, Jon E; Ahola, Kari; Karstinen, Teuvo

2005-01-01

We studied variation in plumage colour and life history in a population of tawny owls (Strix aluco) in southern Finland, using 26 years of data on individually marked male and female owls. Colour was scored on a semi-continuous scale from pale grey to reddish brown. Colour scoring was repeatable and showed a bimodal distribution (grey and brown morph) in both sexes. During the study period, colour composition was stable in the study population in both sexes. The sexes did not mate assortatively with respect to their colour. Colour was a highly heritable trait and was under selection. Grey-coloured male and female owls had a higher lifetime production of fledglings, and grey-coloured male (but not female) owls produced more recruits during their lifetime than brown individuals. Selection on colour was mediated through viability selection and not through fecundity selection. Our results reveal remarkably strong selection on a genetically determined phenotypic trait. PMID:16024349

Colour and pattern change against visually heterogeneous backgrounds in the tree frog Hyla japonica

PubMed Central

Kang, Changku; Kim, Ye Eun; Jang, Yikweon

2016-01-01

Colour change in animals can be adaptive phenotypic plasticity in heterogeneous environments. Camouflage through background colour matching has been considered a primary force that drives the evolution of colour changing ability. However, the mechanism to which animals change their colour and patterns under visually heterogeneous backgrounds (i.e. consisting of more than one colour) has only been identified in limited taxa. Here, we investigated the colour change process of the Japanese tree frog (Hyla japonica) against patterned backgrounds and elucidated how the expression of dorsal patterns changes against various achromatic/chromatic backgrounds with/without patterns. Our main findings are i) frogs primarily responded to the achromatic differences in background, ii) their contrasting dorsal patterns were conditionally expressed dependent on the brightness of backgrounds, iii) against mixed coloured background, frogs adopted intermediate forms between two colours. Using predator (avian and snake) vision models, we determined that colour differences against different backgrounds yielded perceptible changes in dorsal colours. We also found substantial individual variation in colour changing ability and the levels of dorsal pattern expression between individuals. We discuss the possibility of correlational selection on colour changing ability and resting behaviour that maintains the high variation in colour changing ability within population. PMID:26932675

Study of structural colour of Hebomoia glaucippe butterfly wing scales

NASA Astrophysics Data System (ADS)

Shur, V. Ya; Kuznetsov, D. K.; Pryakhina, V. I.; Kosobokov, M. S.; Zubarev, I. V.; Boymuradova, S. K.; Volchetskaya, K. V.

2017-10-01

Structural colours of Hebomoia glaucippe butterfly wing scales have been studied experimentally using high resolution scanning electron microscopy. Visualization of scales structures and computer simulation allowed distinguishing correlation between nanostructures on the scales and their colour.

Colour Changes on the Surface of the Rock Materials Due to UV-A and UV-B Rays

NASA Astrophysics Data System (ADS)

Binal, Adil; Ayderman, Aykut; Sel, Aylin

2015-04-01

The colour of the rocks used in the current buildings, and historical monuments is an important parameter in architecture and engineering. In addition, engineering geologists use the colour in order to identify the weathering class of rock material. The main colour of the stone, especially, are affected by the mineral size, the colour of the primary minerals and matrix material, as well as the colour of the accessory minerals. Due to atmospheric effects, changes in the outer surface colour of the rocks used as siding materials occur with over time. Factors causing the colour change are carbon dioxide (CO2), ozone (O3), sulphate (SO2, SO3) and nitrate (NOx) from the atmosphere with aerosols as well as UV rays from the sun. There is no more work in the literature on colour changes caused by UV-A and UV-B rays. In this study, the effects of ultraviolet in the colour of the surfaces of basalt, limestone, ignimbrite, travertine and sandstone have been simulated with a new experimental device in the laboratory medium. Lutron colour analyser (RGB-1002) was used for the measurements of RGB colours. Colour differences between the beginning and end of tests were determined with the standard practice for calculation of colour tolerances and colour differences from instrumentally measured colour coordinates (ASTM D2244). As a result of the experiments performed, lighten that seem on dark-grey micritic limestone (colour change ratio, CCR: 17.06) and basalt samples (CCR: 8.24) become even visually noticeable. Black and red ignimbrite samples having high porosity were presented the lower rate of colour changes. Finally, colour darkening has been observed in the light-coloured travertine (CCR: 13.8) and sandstone samples (CCR: 20.99).

Real-time and interactive virtual Doppler ultrasound

NASA Astrophysics Data System (ADS)

Hirji, Samira; Downey, Donal B.; Holdsworth, David W.; Steinman, David A.

2005-04-01

This paper describes our "virtual" Doppler ultrasound (DUS) system, in which colour DUS (CDUS) images and DUS spectrograms are generated on-the-fly and displayed in real-time in response to position and orientation cues provided by a magnetically tracked handheld probe. As the presence of complex flow often confounds the interpretation of Doppler ultrasound data, this system will serve to be a fundamental tool for training sonographers and gaining insight into the relationship between ambiguous DUS images and complex blood flow dynamics. Recently, we demonstrated that DUS spectra could be realistically simulated in real-time, by coupling a semi-empirical model of the DUS physics to a 3-D computational fluid dynamics (CFD) model of a clinically relevant flow field. Our system is an evolution of this approach where a motion-tracking device is used to continuously update the origin and orientation of a slice passing through a CFD model of a stenosed carotid bifurcation. After calibrating our CFD model onto a physical representation of a human neck, virtual CDUS images from an instantaneous slice are then displayed at a rate of approximately 15 Hz by simulating, on-the-fly, an array of DUS spectra and colour coding the resulting spectral mean velocity using a traditional Doppler colour scale. Mimicking a clinical examination, the operator can freeze the CDUS image on-screen, and a spectrogram corresponding to the selected sample volume location is rendered at a higher frame rate of at least 30 Hz. All this is achieved using an inexpensive desktop workstation and commodity graphics card.

Correlation between ethylene emission and skin colour changes during papaya (Carica papaya L.) fruit ripening

NASA Astrophysics Data System (ADS)

da Silva, M. G.; Oliveira, J. G.; Vitoria, A. P.; Corrêa, S. F.; Pereira, M. G.; Campostrini, E.; Santos, E. O.; Cavalli, A.; Vargas, H.

2005-06-01

The skin colour changes and ethylene emission rates were monitored during papaya (C. papaya L.) fruit ripening. Two groups of papaya (‘Formosa’ and ‘Solo’) were applied in this study. The total colour difference was used as measured parameter and the corresponding half time of its saturation was used as correlation parameter. A high correlation factor between the saturation half time and corresponding climacteric peak time was found. It was concluded that high ethylene emission rate in ‘Solo’ fruit promotes a quick change of the total colour difference.

Pollinators show flower colour preferences but flowers with similar colours do not attract similar pollinators.

PubMed

Reverté, Sara; Retana, Javier; Gómez, José M; Bosch, Jordi

2016-08-01

Colour is one of the main floral traits used by pollinators to locate flowers. Although pollinators show innate colour preferences, the view that the colour of a flower may be considered an important predictor of its main pollinators is highly controversial because flower choice is highly context-dependent, and initial innate preferences may be overridden by subsequent associative learning. Our objective is to establish whether there is a relationship between flower colour and pollinator composition in natural communities. We measured the flower reflectance spectrum and pollinator composition in four plant communities (85 plant species represented by 109 populations, and 32 305 plant-pollinator interactions in total). Pollinators were divided into six taxonomic groups: bees, ants, wasps, coleopterans, dipterans and lepidopterans. We found consistent associations between pollinator groups and certain colours. These associations matched innate preferences experimentally established for several pollinators and predictions of the pollination syndrome theory. However, flowers with similar colours did not attract similar pollinator assemblages. The explanation for this paradoxical result is that most flower species are pollination generalists. We conclude that although pollinator colour preferences seem to condition plant-pollinator interactions, the selective force behind these preferences has not been strong enough to mediate the appearance and maintenance of tight colour-based plant-pollinator associations. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Colour space influence for vegetation image classification application to Caribbean forest and agriculture

NASA Astrophysics Data System (ADS)

Abadi, M.; Grandchamp, E.

2008-10-01

This paper deals with a comparison of different colour space in order to improve high resolution images classification. The background of this study is the measure of the agriculture impact on the environment in islander context. Biodiversity is particularly sensitive and relevant in such areas and the follow-up of the forest front is a way to ensure its preservation. Very high resolution satellite images are used such as QuickBird and IKONOS scenes. In order to segment the images into forest and agriculture areas, we characterize both ground covers with colour and texture features. A classical unsupervised classifier is then used to obtain labelled areas. As features are computed on coloured images, we can wonder if the colour space choice is relevant. This study has been made considering more than fourteen colour spaces (RGB, YUV, Lab, YIQ, YCrCs, XYZ, CMY, LMS, HSL, KLT, IHS, I1I2I3, HSV, HSI, etc.) and shows the visual and quantitative superiority of IHS on all others. For conciseness reasons, results only show RGB, I1I2I3 and IHS colour spaces.

Role of high molecular mass organics in colour formation during biological treatment of pulp and paper wastewater.

PubMed

Milestone, C B; Stuthridge, T R; Fulthorpe, R R

2007-01-01

This paper forms part of series of biological treatment colour behaviour studies. Surveys across a range of mills have observed colour increases in aerated stabilisation basins of 20-45%. Much of the colour formation has been demonstrated to occur in high molecular mass effluent organic constituents (HMM) present in bleach plant effluents. Removing material greater than 3000 Da essentially eliminated the colour forming ability in both E and D stage wastewaters. We have also shown that pulp and paper sludges contain anaerobic bacteria capable of reducing humic like materials. Colour formation was correlated to the anoxic conditions and the availability of readily biodegradable organic constituents during the wastewater treatment process. Overall, these studies suggest that colour formation in pulp and paper biological treatment systems may be caused by anaerobic bacteria using HMM material from the bleaching effluents as an electron acceptor for growth. This leads to the reduction of the material, which in turn leads to non-reversible internal changes, such as intra-molecular polymerisation or formation of chromophoric functional groups.

Plain faces are more expressive: comparative study of facial colour, mobility and musculature in primates

PubMed Central

Santana, Sharlene E.; Dobson, Seth D.; Diogo, Rui

2014-01-01

Facial colour patterns and facial expressions are among the most important phenotypic traits that primates use during social interactions. While colour patterns provide information about the sender's identity, expressions can communicate its behavioural intentions. Extrinsic factors, including social group size, have shaped the evolution of facial coloration and mobility, but intrinsic relationships and trade-offs likely operate in their evolution as well. We hypothesize that complex facial colour patterning could reduce how salient facial expressions appear to a receiver, and thus species with highly expressive faces would have evolved uniformly coloured faces. We test this hypothesis through a phylogenetic comparative study, and explore the underlying morphological factors of facial mobility. Supporting our hypothesis, we find that species with highly expressive faces have plain facial colour patterns. The number of facial muscles does not predict facial mobility; instead, species that are larger and have a larger facial nucleus have more expressive faces. This highlights a potential trade-off between facial mobility and colour patterning in primates and reveals complex relationships between facial features during primate evolution. PMID:24850898

On the roles of colour and scent in a specialized floral mimicry system

PubMed Central

Vereecken, Nicolas J.; Schiestl, Florian P.

2009-01-01

Background and Aims Sexually deceptive orchids achieve cross-pollination by mimicking the mating signals of female insects, generally hymenopterans. This pollination mechanism is often highly specific as it is based primarily on the mimicry of mating signals, especially the female sex pheromones of the targeted pollinator. Like many deceptive orchids, the Mediterranean species Ophrys arachnitiformis shows high levels of floral trait variation, especially in the colour of the perianth, which is either green or white/pinkinsh within populations. The adaptive significance of perianth colour polymorphism and its influence on pollinator visitation rates in sexually deceptive orchids remain obscure. Methods The relative importance of floral scent versus perianth colour in pollinator attraction in this orchid pollinator mimicry system was evaluated by performing floral scent analyses by gas chromatography-mass spectrometry (GC-MS) and behavioural bioassays with the pollinators under natural conditions were performed. Key Results The relative and absolute amounts of behaviourally active compounds are identical in the two colour morphs of O. arachnitiformis. Neither presence/absence nor the colour of the perianth (green versus white) influence attractiveness of the flowers to Colletes cunicularius males, the main pollinator of O. arachnitiformis. Conclusion Chemical signals alone can mediate the interactions in highly specialized mimicry systems. Floral colour polymorphism in O. arachnitiformis is not subjected to selection imposed by C. cunicularius males, and an interplay between different non-adaptive processes may be responsible for the maintenance of floral colour polymorphism both within and among populations. PMID:19692390

On the roles of colour and scent in a specialized floral mimicry system.

PubMed

Vereecken, Nicolas J; Schiestl, Florian P

2009-11-01

Sexually deceptive orchids achieve cross-pollination by mimicking the mating signals of female insects, generally hymenopterans. This pollination mechanism is often highly specific as it is based primarily on the mimicry of mating signals, especially the female sex pheromones of the targeted pollinator. Like many deceptive orchids, the Mediterranean species Ophrys arachnitiformis shows high levels of floral trait variation, especially in the colour of the perianth, which is either green or white/pinkinsh within populations. The adaptive significance of perianth colour polymorphism and its influence on pollinator visitation rates in sexually deceptive orchids remain obscure. The relative importance of floral scent versus perianth colour in pollinator attraction in this orchid pollinator mimicry system was evaluated by performing floral scent analyses by gas chromatography-mass spectrometry (GC-MS) and behavioural bioassays with the pollinators under natural conditions were performed. The relative and absolute amounts of behaviourally active compounds are identical in the two colour morphs of O. arachnitiformis. Neither presence/absence nor the colour of the perianth (green versus white) influence attractiveness of the flowers to Colletes cunicularius males, the main pollinator of O. arachnitiformis. Chemical signals alone can mediate the interactions in highly specialized mimicry systems. Floral colour polymorphism in O. arachnitiformis is not subjected to selection imposed by C. cunicularius males, and an interplay between different non-adaptive processes may be responsible for the maintenance of floral colour polymorphism both within and among populations.

Design and Implementation of High-Performance GIS Dynamic Objects Rendering Engine

NASA Astrophysics Data System (ADS)

Zhong, Y.; Wang, S.; Li, R.; Yun, W.; Song, G.

2017-12-01

Spatio-temporal dynamic visualization is more vivid than static visualization. It important to use dynamic visualization techniques to reveal the variation process and trend vividly and comprehensively for the geographical phenomenon. To deal with challenges caused by dynamic visualization of both 2D and 3D spatial dynamic targets, especially for different spatial data types require high-performance GIS dynamic objects rendering engine. The main approach for improving the rendering engine with vast dynamic targets relies on key technologies of high-performance GIS, including memory computing, parallel computing, GPU computing and high-performance algorisms. In this study, high-performance GIS dynamic objects rendering engine is designed and implemented for solving the problem based on hybrid accelerative techniques. The high-performance GIS rendering engine contains GPU computing, OpenGL technology, and high-performance algorism with the advantage of 64-bit memory computing. It processes 2D, 3D dynamic target data efficiently and runs smoothly with vast dynamic target data. The prototype system of high-performance GIS dynamic objects rendering engine is developed based SuperMap GIS iObjects. The experiments are designed for large-scale spatial data visualization, the results showed that the high-performance GIS dynamic objects rendering engine have the advantage of high performance. Rendering two-dimensional and three-dimensional dynamic objects achieve 20 times faster on GPU than on CPU.

Protoporphyrin-IX fluorescence guided surgical resection in high-grade gliomas: The potential impact of human colour perception.

PubMed

Petterssen, Max; Eljamel, Sarah; Eljamel, Sam

2014-09-01

Protoporphyrin-IX (Pp-IX) fluorescence had been used frequently in recent years to guide microsurgical resection of high-grade gliomas (HGG), particularly following the publication of a randomized controlled trial demonstrating its advantages. However, Pp-IX fluorescence is dependent upon the surgeons' eyes' perception of red fluorescent colour. This study was designed to evaluate human eye fluorescence perception and establish a fluorescence scale. 20 of 108 pre-recorded images from intraoperative fluorescence of HGG were used to construct an 8-panel visual analogue fluorescence scale. The scale was validated by testing 56 participants with normal colour vision and three red-green colour-blind participants. For intra-rater agreement ten participants were tested twice and for inter-observer reliability the whole cohort were tested. The intra- and inter-observer reliability of the scale in normal colour vision participants was excellent. The scale was less reliable in the violet-blue panels of the scale. Colour-blind participants were not able to distinguish between red fluorescence and blue-violet colours. The 8-panel fluorescence scale is valid in differentiating red, pink and blue colours in a fluorescence surgical field among participants with normal colour perception and potentially useful to standardize fluorescence-guided surgery. However, colourblind surgeons should not use fluorescence-guided surgery. Copyright © 2014 Elsevier B.V. All rights reserved.

Exploring the functional nature of synaesthetic colour: Dissociations from colour perception and imagery.

PubMed

Chiou, Rocco; Rich, Anina N; Rogers, Sebastian; Pearson, Joel

2018-08-01

Individuals with grapheme-colour synaesthesia experience anomalous colours when reading achromatic text. These unusual experiences have been said to resemble 'normal' colour perception or colour imagery, but studying the nature of synaesthesia remains difficult. In the present study, we report novel evidence that synaesthetic colour impacts conscious vision in a way that is different from both colour perception and imagery. Presenting 'normal' colour prior to binocular rivalry induces a location-dependent suppressive bias reflecting local habituation. By contrast, a grapheme that evokes synaesthetic colour induces a facilitatory bias reflecting priming that is not constrained to the inducing grapheme's location. This priming does not occur in non-synaesthetes and does not result from response bias. It is sensitive to diversion of visual attention away from the grapheme, but resistant to sensory perturbation, reflecting a reliance on cognitive rather than sensory mechanisms. Whereas colour imagery in non-synaesthetes causes local priming that relies on the locus of imagined colour, imagery in synaesthetes caused global priming not dependent on the locus of imagery. These data suggest a unique psychophysical profile of high-level colour processing in synaesthetes. Our novel findings and method will be critical to testing theories of synaesthesia and visual awareness. Copyright © 2018 Elsevier B.V. All rights reserved.

How to scientifically assess a restoration project: a case study

NASA Astrophysics Data System (ADS)

Alvarez de Buergo, M.; Fort, R.; Freire, D. M.; Lopez-Arce, P.; Vazquez-Calvo, C.

2012-04-01

Commonly, it is said that there is lack of communication among scientists, conservators, restorers, project managers and architects. But sometimes this communication flows, and we can find enormous benefits from and for all the participating agents. This is the case we present in this work, in which technical agents in charge of the restoration of a building, asked for some scientific advice to perform the restoration of a heritage building. The results were successful and fantastic for both of them, in terms of one part asking for consultation and the other answering to the demands and resolving real problems. This is the case of a marvellous Renaissance building (Medinaceli Dukes palace, 15th-16th centuries) in the central area of Spain (Cogolludo, Guadalajara). Focused on the restoration project, we were asked for consultancy on how to solve matters like the assessment of the already fixed in project cleaning method for the stone façades, the efficacy and durability methods for some conservation products to be applied, the presence or not of a patina on the stone; the viability of using some restoration mortars, and the origin of some efflorescences that came out just after placed in the building a restoration rendering mortar. Responses to these matters were answered by performing tests both in the lab and on site in the building. The efficiency and effects on stone of the blasting cleaning method was assessed by first analysing the nature and thickness of the surface deposits to be removed (SEM-EDS analyses); secondly, roughness and colour measurements were performed, and thirdly, SEM-EDS analyses were carried out again to determine whether the cleaning method was able to remove part of the surface deposits, completely, or even part of the stone substrate. Some conservation products were tested on stone specimens, both their efficacy and their durability, concluding that it was better not to apply any of them. A patina was found on the stone façade under SEM, probably applied for colouring and homogenizing purpose, and below it and on the stone, an acrylic film was analysed. It was in good state, and its removal could be worse and more dangerous to the substrate than leaving it. Two restoration mortars were tested to characterize them and to determine their durability, the results showing that one of them was much better than the other. Finally, a restoration render was analysed and we found, by analysing it and the raw materials used for its preparation, that one of them, a marketed cement, had a very high content on sulfates, responsible for the efflorescences (sulphate compounds) that appeared just after the render was placed in the building, this resulting on stopping using this product in the restoration project. Consequently, conservation science should be considered as not only useful but essential for cultural heritage conservation, besides it is cost-saving, because failed interventions are much more expensive in the short, medium and long term.

An experimental test of the contributions and condition dependence of microstructure and carotenoids in yellow plumage coloration

PubMed Central

Shawkey, Matthew D; Hill, Geoffrey E; McGraw, Kevin J; Hood, Wendy R; Huggins, Kristal

2006-01-01

A combination of structural and pigmentary components is responsible for many of the colour displays of animals. Despite the ubiquity of this type of coloration, neither the relative contribution of structures and pigments to variation in such colour displays nor the relative effects of extrinsic factors on the structural and pigment-based components of such colour has been determined. Understanding the sources of colour variation is important because structures and pigments may convey different information to conspecifics. In an experiment on captive American goldfinches Carduelis tristis, we manipulated two parameters, carotenoid availability and food availability, known to affect the expression of carotenoid pigments in a full-factorial design. Yellow feathers from these birds were then analysed in two ways. First, we used full-spectrum spectrometry and high-performance liquid chromatography to examine the extent to which variation in white structural colour and total carotenoid content was associated with variation in colour properties of feathers. The carotenoid content of yellow feathers predicted two colour parameters (principal component 1—representing high values of ultraviolet and yellow chroma and low values of violet–blue chroma—and hue). Two different colour parameters (violet–blue and yellow chroma) from white de-pigmented feathers, as well as carotenoid content, predicted reflectance measurements from yellow feathers. Second, we determined the relative effects of our experimental manipulations on white structural colour and yellow colour. Carotenoid availability directly affected yellow colour, while food availability affected it only in combination with carotenoid availability. None of our manipulations had significant effects on the expression of white structural colour. Our results suggest that the contribution of microstructures to variation in the expression of yellow coloration is less than the contribution of carotenoid content, and that carotenoid deposition is more dependent on extrinsic variability than is the production of white structural colour. PMID:17015356

An experimental test of the contributions and condition dependence of microstructure and carotenoids in yellow plumage coloration.

PubMed

Shawkey, Matthew D; Hill, Geoffrey E; McGraw, Kevin J; Hood, Wendy R; Huggins, Kristal

2006-12-07

A combination of structural and pigmentary components is responsible for many of the colour displays of animals. Despite the ubiquity of this type of coloration, neither the relative contribution of structures and pigments to variation in such colour displays nor the relative effects of extrinsic factors on the structural and pigment-based components of such colour has been determined. Understanding the sources of colour variation is important because structures and pigments may convey different information to conspecifics. In an experiment on captive American goldfinches Carduelis tristis, we manipulated two parameters, carotenoid availability and food availability, known to affect the expression of carotenoid pigments in a full-factorial design. Yellow feathers from these birds were then analysed in two ways. First, we used full-spectrum spectrometry and high-performance liquid chromatography to examine the extent to which variation in white structural colour and total carotenoid content was associated with variation in colour properties of feathers. The carotenoid content of yellow feathers predicted two colour parameters (principal component 1--representing high values of ultraviolet and yellow chroma and low values of violet-blue chroma-and hue). Two different colour parameters (violet-blue and yellow chroma) from white de-pigmented feathers, as well as carotenoid content, predicted reflectance measurements from yellow feathers. Second, we determined the relative effects of our experimental manipulations on white structural colour and yellow colour. Carotenoid availability directly affected yellow colour, while food availability affected it only in combination with carotenoid availability. None of our manipulations had significant effects on the expression of white structural colour. Our results suggest that the contribution of microstructures to variation in the expression of yellow coloration is less than the contribution of carotenoid content, and that carotenoid deposition is more dependent on extrinsic variability than is the production of white structural colour.

Sputum colour can identify patients with neutrophilic inflammation in asthma

PubMed Central

Gibson, Peter; Lochrin, Alyssa J; Wood, Lisa; Baines, Katherine J; Simpson, Jodie L

2017-01-01

Introduction Sputum colour is associated with neutrophilic inflammation in chronic bronchitis and chronic obstructive pulmonary disease (COPD). Neutrophilia and sputum expectoration is notable in asthma, but whether sputum colour is associated with and predicts the presence of neutrophilic inflammation in asthma is unknown. The objective of the study is to assess the ability of sputum colour in distinguishing asthma inflammatory phenotypes. Methods Induced sputum samples collected from 271 adults with stable asthma were retrospectively assessed. Sputum colour was determined using the BronkoTest sputum colour chart and correlated to differential cell counts and CXCL-8 concentration. Neutrophilic inflammation was defined as an age-corrected sputum neutrophil proportion (≥61.6% for age 20–40 years; ≥63.2% for age 40–60 and ≥67.2% for age >60 years), whereas neutrophilic bronchitis (NB) was defined as high total cell count (≥5.1×106 cells/mL) plus an increased age-corrected neutrophil proportion. The optimal cut-off for sputum colour to predict neutrophilic inflammation and NB was determined using receiver operator characteristic curve analysis. Results A sputum colour score of ≥3 represented and predicted neutrophilic inflammation with modest accuracy (area under the curve (AUC)=0.64; p<0.001, specificity=78.4%, sensitivity=49.2%). Participants with a sputum colour score of ≥3 had significantly (p<0.05) higher CXCL-8, total cells and neutrophil number and proportion. Sputum colour score was also positively correlated with these factors. Sputum colour score ≥3 predicted NB with reasonably good accuracy (AUC=0.79, p<0.001, specificity=79.3%, sensitivity=70.7%). Conclusions Visual gradation of sputum colour in asthma relates to high total cell count and neutrophilic inflammation. Assessment of sputum colour can identify adults with asthma who are likely to have NB without the need for sputum processing and differential cell count, which may facilitate asthma management. PMID:29071085

Investigation of the chemomarkers correlated with flower colour in different organs of Catharanthus roseus using NMR-based metabolomics.

PubMed

Pan, Qifang; Dai, Yuntao; Nuringtyas, Tri Rini; Mustafa, Natali Rianika; Schulte, Anna Elisabeth; Verpoorte, Robert; Choi, Young Hae

2014-01-01

Flower colour is a complex phenomenon that involves a wide range of secondary metabolites of flowers, for example phenolics and carotenoids as well as co-pigments. Biosynthesis of these metabolites, though, occurs through complicated pathways in many other plant organs. The analysis of the metabolic profile of leaves, stems and roots, for example, therefore may allow the identification of chemomarkers related to the final expression of flower colour. To investigate the metabolic profile of leaves, stems, roots and flowers of Catharanthus roseus and the possible correlation with four flower colours (orange, pink, purple and red). (1) H-NMR and multivariate data analysis were used to characterise the metabolites in the organs. The results showed that flower colour is characterised by a special pattern of metabolites such as anthocyanins, flavonoids, organic acids and sugars. The leaves, stems and roots also exhibit differences in their metabolic profiles according to the flower colour. Plants with orange flowers featured a relatively high level of kaempferol analogues in all organs except roots. Red-flowered plants showed a high level of malic acid, fumaric acid and asparagine in both flowers and leaves, and purple and pink flowering plants exhibited high levels of sucrose, glucose and 2,3-dihydroxy benzoic acid. High concentrations of quercetin analogues were detected in flowers and leaves of purple-flowered plants. There is a correlation between the metabolites specifically associated to the expression of different flower colours and the metabolite profile of other plant organs and it is therefore possible to predict the flower colours by detecting specific metabolites in leaves, stems or roots. This may have interesting application in the plant breeding industry. Copyright © 2013 John Wiley & Sons, Ltd.

UV durable colour pigment doped SmA liquid crystal composites for outdoor trans-reflective bi-stable displays

NASA Astrophysics Data System (ADS)

Xu, H.; Davey, A. B.; Crossland, W. A.; Chu, D. P.

2012-10-01

High brightness trans-reflective bi-stable displays based on smectic A (SmA) liquid crystals (LCs) can have nearly perfect transparency in the clear state and very high reflection in the scattered state. Because the LC material in use is stable under UV radiation, this kind of displays can stand for strong day-light and therefore be ideal for outdoor applications from e-books to public signage and advertisement. However, the colour application has been limited because the traditional colourants in use are conventional dyes which are lack of UV stability and that their colours are easily photo bleached. Here we present a colour SmA display demonstrator using pigments as colourant. Mixing pigments with SmA LCs and maintain the desirable optical switching performance is not straightforward. We show here how it can be done, including how to obtain fine sized pigment nano-particles, the effects of particle size and size distribution on the display performance. Our optimized pigments/SmA compositions can be driven by a low frequency waveform (~101Hz) to a scattered state to exhibit colour while by a high frequency waveform (~103Hz) to a cleared state showing no colour. Finally, we will present its excellent UV life-time (at least <7.2 years) in comparison with that of dye composition (~2.4 years). The complex interaction of pigment nano-particles with LC molecules and the resulting effects on the LC electro-optical performances are still to be fully understood. We hope this work will not only demonstrate a new and practical approach for outdoor reflective colour displays but also provide a new material system for fundamental liquid crystal colloid research work.

Morphological and colour morph clines along an altitudinal gradient in the meadow grasshopper Pseudochorthippus parallelus.

PubMed

Köhler, Günter; Samietz, Jörg; Schielzeth, Holger

2017-01-01

Many animals show altitudinal clines in size, shape and body colour. Increases in body size and reduction in the length of body appendices in colder habitats are usually attributed to improved heat conservation at lower surface-to-volume ratios (known as Bergmann's and Allen's rule, respectively). However, the patterns are more variable and sometimes reversed in small ectotherms that are affected by shortened growing seasons. Altitude can also affect colouration. The thermal melanism hypothesis predicts darker colours under cooler conditions because of a thermoregulatory advantage. Darker colours may also be favoured at high altitudes for reasons of UV protection or habitat-dependent crypsis. We studied altitudinal variation in morphology and colour in the colour-polymorphic meadow grasshopper Pseudochorthippus parallelus based on 563 individuals from 17 populations sampled between 450 and 2,500 m asl. Pronotum length did not change with altitude, while postfemur length decreased significantly in both sexes. Tegmen (forewing) length decreased in males, but not in females. The results indicate that while body size, as best quantified by pronotum length, was remarkably constant, extended appendices were reduced at high altitudes. The pattern thus follows Allen's rule, but neither Bergmann's nor converse Bergmann's rule. These results indicate that inference of converse Bergmann's rule based on measurements from appendices should be treated with some caution. Colour morph ratios showed significant changes in both sexes from lowland populations dominated by green individuals to high-altitude populations dominated by brown ones. The increase of brown morphs was particularly steep between 1,500 and 2,000 m asl. The results suggest shared control of colour in males and females and local adaptation along the altitudinal gradient following the predictions of the thermal melanism hypothesis. Interestingly, both patterns, the reduction of body appendices and the higher frequency of brown individuals, may be explained by a need for efficient thermoregulation under high-altitude conditions.

The perception of isoluminant coloured stimuli of amblyopic eye and defocused eye

NASA Astrophysics Data System (ADS)

Krumina, Gunta; Ozolinsh, Maris; Ikaunieks, Gatis

2008-09-01

In routine eye examination the visual acuity usually is determined using standard charts with black letters on a white background, however contrast and colour are important characteristics of visual perception. The purpose of research was to study the perception of isoluminant coloured stimuli in the cases of true and simulated amlyopia. We estimated difference in visual acuity with isoluminant coloured stimuli comparing to that for high contrast black-white stimuli for true amblyopia and simulated amblyopia. Tests were generated on computer screen. Visual acuity was detected using different charts in two ways: standard achromatic stimuli (black symbols on a white background) and isoluminant coloured stimuli (white symbols on a yellow background, grey symbols on blue, green or red background). Thus isoluminant tests had colour contrast only but had no luminance contrast. Visual acuity evaluated with the standard method and colour tests were studied for subjects with good visual acuity, if necessary using the best vision correction. The same was performed for subjects with defocused eye and with true amblyopia. Defocus was realized with optical lenses placed in front of the normal eye. The obtained results applying the isoluminant colour charts revealed worsening of the visual acuity comparing with the visual acuity estimated with a standard high contrast method (black symbols on a white background).

Physicochemical characteristics and quality parameters of a beef product subjected to chemical preservatives and high hydrostatic pressure.

PubMed

Giménez, Belén; Graiver, Natalia; Califano, Alicia; Zaritzky, Noemí

2015-02-01

The use of high hydrostatic pressure (HHP) on fresh beef causes a deleterious effect on red colour. A beef product subjected to HHP exhibiting acceptable colour and microbiological stability was developed; the process requires as a first step the immersion in a preservative solution containing ascorbic acid, sodium nitrite, and sodium chloride. Desirability functions were used to optimise the composition of this solution in order to maintain the colour attributes minimising the concentration of sodium nitrite. The product was packed in low gas permeability film before HHP treatment. The effect of the applied pressure (300, 600 MPa) on quality parameters (colour,texture) was analysed. The stability of the product during storage at 4 °C was determined by microbial counts, colour, texture, and exudate. The combination of treatments provided acceptable colour and microbiological stability during four and six weeks of refrigerated storage after the product has been subjected to 300 and 600 MPa, respectively.

Human Commercial Models' Eye Colour Shows Negative Frequency-Dependent Selection.

PubMed

Forti, Isabela Rodrigues Nogueira; Young, Robert John

2016-01-01

In this study we investigated the eye colour of human commercial models registered in the UK (400 female and 400 male) and Brazil (400 female and 400 male) to test the hypothesis that model eye colour frequency was the result of negative frequency-dependent selection. The eye colours of the models were classified as: blue, brown or intermediate. Chi-square analyses of data for countries separated by sex showed that in the United Kingdom brown eyes and intermediate colours were significantly more frequent than expected in comparison to the general United Kingdom population (P<0.001). In Brazil, the most frequent eye colour brown was significantly less frequent than expected in comparison to the general Brazilian population. These results support the hypothesis that model eye colour is the result of negative frequency-dependent selection. This could be the result of people using eye colour as a marker of genetic diversity and finding rarer eye colours more attractive because of the potential advantage more genetically diverse offspring that could result from such a choice. Eye colour may be important because in comparison to many other physical traits (e.g., hair colour) it is hard to modify, hide or disguise, and it is highly polymorphic.

IRIS COLOUR CLASSIFICATION SCALES – THEN AND NOW

PubMed Central

Grigore, Mariana; Avram, Alina

2015-01-01

Eye colour is one of the most obvious phenotypic traits of an individual. Since the first documented classification scale developed in 1843, there have been numerous attempts to classify the iris colour. In the past centuries, iris colour classification scales has had various colour categories and mostly relied on comparison of an individual’s eye with painted glass eyes. Once photography techniques were refined, standard iris photographs replaced painted eyes, but this did not solve the problem of painted/ printed colour variability in time. Early clinical scales were easy to use, but lacked objectivity and were not standardised or statistically tested for reproducibility. The era of automated iris colour classification systems came with the technological development. Spectrophotometry, digital analysis of high-resolution iris images, hyper spectral analysis of the human real iris and the dedicated iris colour analysis software, all accomplished an objective, accurate iris colour classification, but are quite expensive and limited in use to research environment. Iris colour classification systems evolved continuously due to their use in a wide range of studies, especially in the fields of anthropology, epidemiology and genetics. Despite the wide range of the existing scales, up until present there has been no generally accepted iris colour classification scale. PMID:27373112

IRIS COLOUR CLASSIFICATION SCALES--THEN AND NOW.

PubMed

Grigore, Mariana; Avram, Alina

2015-01-01

Eye colour is one of the most obvious phenotypic traits of an individual. Since the first documented classification scale developed in 1843, there have been numerous attempts to classify the iris colour. In the past centuries, iris colour classification scales has had various colour categories and mostly relied on comparison of an individual's eye with painted glass eyes. Once photography techniques were refined, standard iris photographs replaced painted eyes, but this did not solve the problem of painted/ printed colour variability in time. Early clinical scales were easy to use, but lacked objectivity and were not standardised or statistically tested for reproducibility. The era of automated iris colour classification systems came with the technological development. Spectrophotometry, digital analysis of high-resolution iris images, hyper spectral analysis of the human real iris and the dedicated iris colour analysis software, all accomplished an objective, accurate iris colour classification, but are quite expensive and limited in use to research environment. Iris colour classification systems evolved continuously due to their use in a wide range of studies, especially in the fields of anthropology, epidemiology and genetics. Despite the wide range of the existing scales, up until present there has been no generally accepted iris colour classification scale.

The colour of pain: can patients use colour to describe osteoarthritis pain?

PubMed

Wylde, Vikki; Wells, Victoria; Dixon, Samantha; Gooberman-Hill, Rachael

2014-03-01

The aim of the present study was to explore patients' views on the acceptability and feasibility of using colour to describe osteoarthritis (OA) pain, and whether colour could be used to communicate pain to healthcare professionals. Six group interviews were conducted with 17 patients with knee OA. Discussion topics included first impressions about using colour to describe pain, whether participants could associate their pain with colour, how colours related to changes to intensity and different pain qualities, and whether they could envisage using colour to describe pain to healthcare professionals. The group interviews indicated that, although the idea of using colour was generally acceptable, it did not suit all participants as a way of describing their pain. The majority of participants chose red to describe high-intensity pain; the reasons given were because red symbolized inflammation, fire, anger and the stop signal in a traffic light system. Colours used to describe the absence of pain were chosen because of their association with positive emotional feelings, such as purity, calmness and happiness. A range of colours was chosen to represent changes in pain intensity. Aching pain was consistently identified as being associated with colours such as grey or black, whereas sharp pain was described using a wider selection of colours. The majority of participants thought that they would be able to use colour to describe their pain to healthcare professionals, although issues around the interpretability and standardization of colour were raised. For some patients, using colour to describe their pain experience may be a useful tool to improve doctor-patient communication. Copyright © 2013 John Wiley & Sons, Ltd.

Automatic perception and synaesthesia: evidence from colour and photism naming in a stroop-negative priming task.

PubMed

Lupiáñez, Juan; Callejas, Alicia

2006-02-01

It is widely assumed that synaesthetic perception is highly automatic, as shown by Stroop test. Furthermore, it has been shown that, although automatic, it can be suppressed leading to Negative Priming (NP). However, these assumptions have not been consistently investigated, as not many papers have measured Stroop in synaesthesia, and only one used a NP procedure. Two experiments were carried out in a female synaesthete (MA), and 13 control participants, in which numbers and letters were displayed in colours either congruent or incongruent with MA's photisms. In contrast to control participants, MA showed significant Stroop effect both when naming the colours and when naming the photisms (slower RT when naming a colour or photism that was incongruently coloured versus congruently coloured). For comparison, we also report a control experiment in which the first letters of colour names were displayed in either congruent (e.g., B in blue) or incongruent (e.g., B in red) colours. Significant Stroop and NP effects were found when a control group named the displayed colour of these letters. The synaesthesic Stroop effect shown by MA was greater than that observed in the Control Experiment when MA was to name the displayed colour, but smaller when she was to name the photism of the stimuli. Regarding NP, MA showed an effect similar to that observed in the Control Experiment, but only when she was to name the photisms of the stimuli. Altogether, these results show that synaesthetic perception is highly automatic and difficult to inhibit.

Efficient and bright organic light-emitting diodes on single-layer graphene electrodes

NASA Astrophysics Data System (ADS)

Li, Ning; Oida, Satoshi; Tulevski, George S.; Han, Shu-Jen; Hannon, James B.; Sadana, Devendra K.; Chen, Tze-Chiang

2013-08-01

Organic light-emitting diodes are emerging as leading technologies for both high quality display and lighting. However, the transparent conductive electrode used in the current organic light-emitting diode technologies increases the overall cost and has limited bendability for future flexible applications. Here we use single-layer graphene as an alternative flexible transparent conductor, yielding white organic light-emitting diodes with brightness and efficiency sufficient for general lighting. The performance improvement is attributed to the device structure, which allows direct hole injection from the single-layer graphene anode into the light-emitting layers, reducing carrier trapping induced efficiency roll-off. By employing a light out-coupling structure, phosphorescent green organic light-emitting diodes exhibit external quantum efficiency >60%, while phosphorescent white organic light-emitting diodes exhibit external quantum efficiency >45% at 10,000 cd m-2 with colour rendering index of 85. The power efficiency of white organic light-emitting diodes reaches 80 lm W-1 at 3,000 cd m-2, comparable to the most efficient lighting technologies.

Testing the AUDI2000 colour-difference formula for solid colours using some visual datasets with usefulness to automotive industry

NASA Astrophysics Data System (ADS)

Martínez-García, Juan; Melgosa, Manuel; Gómez-Robledo, Luis; Li, Changjun; Huang, Min; Liu, Haoxue; Cui, Guihua; Luo, M. Ronnier; Dauser, Thomas

2013-11-01

Colour-difference formulas are tools employed in colour industries for objective pass/fail decisions of manufactured products. These objective decisions are based on instrumental colour measurements which must reliably predict the subjective colour-difference evaluations performed by observers' panels. In a previous paper we have tested the performance of different colour-difference formulas using the datasets employed at the development of the last CIErecommended colour-difference formula CIEDE2000, and we found that the AUDI2000 colour-difference formula for solid (homogeneous) colours performed reasonably well, despite the colour pairs in these datasets were not similar to those typically employed in the automotive industry (CIE Publication x038:2013, 465-469). Here we have tested again AUDI2000 together with 11 advanced colour-difference formulas (CIELUV, CIELAB, CMC, BFD, CIE94, CIEDE2000, CAM02-UCS, CAM02-SCD, DIN99d, DIN99b, OSA-GP-Euclidean) for three visual datasets we may consider particularly useful to the automotive industry because of different reasons: 1) 828 metallic colour pairs used to develop the highly reliable RIT-DuPont dataset (Color Res. Appl. 35, 274-283, 2010); 2) printed samples conforming 893 colour pairs with threshold colour differences (J. Opt. Soc. Am. A 29, 883-891, 2012); 3) 150 colour pairs in a tolerance dataset proposed by AUDI. To measure the relative merits of the different tested colour-difference formulas, we employed the STRESS index (J. Opt. Soc. Am. A 24, 1823-1829, 2007), assuming a 95% confidence level. For datasets 1) and 2), AUDI2000 was in the group of the best colour-difference formulas with no significant differences with respect to CIE94, CIEDE2000, CAM02-UCS, DIN99b and DIN99d formulas. For dataset 3) AUDI2000 provided the best results, being statistically significantly better than all other tested colour-difference formulas.

The unsuitability of HTML-based colour charts for estimating animal colours--a comment on Berggren and Merilä (2004).

PubMed

Stevens, Martin; Cuthill, Innes C

2005-08-30

A variety of techniques are used to study the colours of animal signals, including the use of visual matching to colour charts. This paper aims to highlight why they are generally an unsatisfactory tool for the measurement and classification of animal colours and why colour codes based on HTML (really RGB) standards, as advocated in a recent paper, are particularly inappropriate. There are many theoretical arguments against the use of colour charts, not least that human colour vision differs markedly from that of most other animals. However, the focus of this paper is the concern that, even when applied to humans, there is no simple 1:1 mapping from an RGB colour space to the perceived colours in a chart (the results are both printer- and illumination-dependent). We support our criticisms with data from colour matching experiments with humans, involving self-made, printed colour charts. Colour matching experiments with printed charts involving 11 subjects showed that the choices made by individuals were significantly different between charts that had exactly the same RGB values, but were produced from different printers. Furthermore, individual matches tended to vary under different lighting conditions. Spectrophotometry of the colour charts showed that the reflectance spectra of the charts varied greatly between printers and that equal steps in RGB space were often far from equal in terms of reflectance on the printed charts. In addition to outlining theoretical criticisms of the use of colour charts, our empirical results show that: individuals vary in their perception of colours, that different printers produce strikingly different results when reproducing what should be the same chart, and that the characteristics of the light irradiating the surface do affect colour perception. Therefore, we urge great caution in the use of colour charts to study animal colour signals. They should be used only as a last resort and in full knowledge of their limitations, with specially produced charts made to high industry standards.

THE COLOUR GLASS CONDENSATE: AN INTRODUCTION

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

IANCU,E.; LEONIDOV,A.; MCLERRAN,L.

2001-08-06

In these lectures, the authors develop the theory of the Colour Glass Condensate. This is the matter made of gluons in the high density environment characteristic of deep inelastic scattering or hadron-hadron collisions at very high energy. The lectures are self contained and comprehensive. They start with a phenomenological introduction, develop the theory of classical gluon fields appropriate for the Colour Glass, and end with a derivation and discussion of the renormalization group equations which determine this effective theory.

Colour removal and carbonyl by-production in high dose ozonation for effluent polishing.

PubMed

Mezzanotte, V; Fornaroli, R; Canobbio, S; Zoia, L; Orlandi, M

2013-04-01

Experimental tests have been conducted to investigate the efficiency and the by-product generation of high dose ozonation (10-60 mg O3 L(-1)) for complete colour removal from a treated effluent with an important component of textile dyeing wastewater. The effluent is discharged into an effluent-dominated stream where no dilution takes place, and, thus, the quality requirement for the effluents is particularly strict. 30, 60 and 90 min contact times were adopted. Colour was measured as absorbance at 426, 558 and 660 nm wavelengths. pH was monitored throughout the experiments. The experimental work showed that at 50 mg L(-1) colour removal was complete and at 60 mg O3 L(-1) the final aldehyde concentration ranged between 0.72 and 1.02 mg L(-1). Glyoxal and methylglyoxal concentrations were directly related to colour removal, whereas formaldehyde, acetaldehyde, acetone and acrolein were not. Thus, the extent of colour removal can be used to predict the increase in glyoxal and methylglyoxal concentrations. As colour removal can be assessed by a simple absorbance measurement, in contrast to the analysis of specific carbonyl compounds, which is much longer and complex, the possibility of using colour removal as an indicator for predicting the toxic potential of ozone by-products for textile effluents is of great value. Copyright © 2013 Elsevier Ltd. All rights reserved.

Low Predictability of Colour Polymorphism in Introduced Guppy (Poecilia reticulata) Populations in Panama

PubMed Central

Martínez, Celestino; Chavarría, Carmen; Sharpe, Diana M. T.; De León, Luis Fernando

2016-01-01

Colour polymorphism is a recurrent feature of natural populations, and its maintenance has been studied in a range of taxa in their native ranges. However, less is known about whether (and how) colour polymorphism is maintained when populations are removed from their native environments, as in the case of introduced species. We here address this issue by analyzing variation in colour patterns in recently-discovered introduced populations of the guppy (Poecilia reticulata) in Panama. Specifically, we use classic colour analysis to estimate variation in the number and the relative area of different colour spots across low predation sites in the introduced Panamanian range of the species. We then compare this variation to that found in the native range of the species under low- and high predation regimes. We found aspects of the colour pattern that were both consistent and inconsistent with the classical paradigm of colour evolution in guppies. On one hand, the same colours that dominated in native populations (orange, iridescent and black) were also the most dominant in the introduced populations in Panama. On the other, there were no clear differences between either introduced-low and native low- and high predation populations. Our results are therefore only partially consistent with the traditional role of female preference in the absence of predators, and suggest that additional factors could influence colour patterns when populations are removed from their native environments. Future research on the interaction between female preference and environmental variability (e.g. multifarious selection), could help understand adaptive variation in this widely-introduced species, and the contexts under which variation in adaptive traits parallels (or not) variation in the native range. PMID:26863538

Low Predictability of Colour Polymorphism in Introduced Guppy (Poecilia reticulata) Populations in Panama.

PubMed

Martínez, Celestino; Chavarría, Carmen; Sharpe, Diana M T; De León, Luis Fernando

2016-01-01

Colour polymorphism is a recurrent feature of natural populations, and its maintenance has been studied in a range of taxa in their native ranges. However, less is known about whether (and how) colour polymorphism is maintained when populations are removed from their native environments, as in the case of introduced species. We here address this issue by analyzing variation in colour patterns in recently-discovered introduced populations of the guppy (Poecilia reticulata) in Panama. Specifically, we use classic colour analysis to estimate variation in the number and the relative area of different colour spots across low predation sites in the introduced Panamanian range of the species. We then compare this variation to that found in the native range of the species under low- and high predation regimes. We found aspects of the colour pattern that were both consistent and inconsistent with the classical paradigm of colour evolution in guppies. On one hand, the same colours that dominated in native populations (orange, iridescent and black) were also the most dominant in the introduced populations in Panama. On the other, there were no clear differences between either introduced-low and native low- and high predation populations. Our results are therefore only partially consistent with the traditional role of female preference in the absence of predators, and suggest that additional factors could influence colour patterns when populations are removed from their native environments. Future research on the interaction between female preference and environmental variability (e.g. multifarious selection), could help understand adaptive variation in this widely-introduced species, and the contexts under which variation in adaptive traits parallels (or not) variation in the native range.

Coherence across consciousness levels: Symmetric visual displays spare working memory resources.

PubMed

Dumitru, Magda L

2015-12-15

Two studies demonstrate that the need for coherence could nudge individuals to use structural similarities between binary visual displays and two concurrent cognitive tasks to unduly solve the latter in similar fashion. In an overt truth-judgement task, participants decided whether symmetric colourful displays matched conjunction or disjunction descriptions (e.g., "the black and/or the orange"). In the simultaneous covert categorisation task, they decided whether a colour name (e.g., "black") described a two-colour object or half of a single-colour object. Two response patterns emerged as follows. Participants either acknowledged or rejected matches between disjunction descriptions and two visual stimuli and, similarly, either acknowledged or rejected matches between single colour names and two-colour objects or between single colour names and half of single-colour objects. These findings confirm the coherence hypothesis, highlight the role of coherence in preserving working-memory resources, and demonstrate an interaction between high-level and low-level consciousness. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of memory load on hemispheric asymmetries of colour memory.

PubMed

Clapp, Wes; Kirk, Ian J; Hausmann, Markus

2007-03-01

Hemispheric asymmetries in colour perception have been a matter of debate for some time. Recent evidence suggests that lateralisation of colour processing may be largely task specific. Here we investigated hemispheric asymmetries during different types and phases of a delayed colour-matching (recognition) memory task. A total of 11 male and 12 female right-handed participants performed colour-memory tasks. The task involved presentation of a set of colour stimuli (encoding), and subsequent indication (forced choice) of which colours in a larger set had previously appeared at the retrieval or recognition phase. The effect of memory load (set size), and the effect of lateralisation at the encoding or retrieval phases were investigated. Overall, the results indicate a right hemisphere advantage in colour processing, which was particularly pronounced in high memory load conditions, and was seen in males rather than female participants. The results suggest that verbal (mnemonic) strategies can significantly affect the magnitude of hemispheric asymmetries in a non-verbal task.

Optical colour image watermarking based on phase-truncated linear canonical transform and image decomposition

NASA Astrophysics Data System (ADS)

Su, Yonggang; Tang, Chen; Li, Biyuan; Lei, Zhenkun

2018-05-01

This paper presents a novel optical colour image watermarking scheme based on phase-truncated linear canonical transform (PT-LCT) and image decomposition (ID). In this proposed scheme, a PT-LCT-based asymmetric cryptography is designed to encode the colour watermark into a noise-like pattern, and an ID-based multilevel embedding method is constructed to embed the encoded colour watermark into a colour host image. The PT-LCT-based asymmetric cryptography, which can be optically implemented by double random phase encoding with a quadratic phase system, can provide a higher security to resist various common cryptographic attacks. And the ID-based multilevel embedding method, which can be digitally implemented by a computer, can make the information of the colour watermark disperse better in the colour host image. The proposed colour image watermarking scheme possesses high security and can achieve a higher robustness while preserving the watermark’s invisibility. The good performance of the proposed scheme has been demonstrated by extensive experiments and comparison with other relevant schemes.

Evolution of colour vision in mammals.

PubMed

Jacobs, Gerald H

2009-10-12

Colour vision allows animals to reliably distinguish differences in the distributions of spectral energies reaching the eye. Although not universal, a capacity for colour vision is sufficiently widespread across the animal kingdom to provide prima facie evidence of its importance as a tool for analysing and interpreting the visual environment. The basic biological mechanisms on which vertebrate colour vision ultimately rests, the cone opsin genes and the photopigments they specify, are highly conserved. Within that constraint, however, the utilization of these basic elements varies in striking ways in that they appear, disappear and emerge in altered form during the course of evolution. These changes, along with other alterations in the visual system, have led to profound variations in the nature and salience of colour vision among the vertebrates. This article concerns the evolution of colour vision among the mammals, viewing that process in the context of relevant biological mechanisms, of variations in mammalian colour vision, and of the utility of colour vision.

Evolution of colour vision in mammals

PubMed Central

Jacobs, Gerald H.

2009-01-01

Colour vision allows animals to reliably distinguish differences in the distributions of spectral energies reaching the eye. Although not universal, a capacity for colour vision is sufficiently widespread across the animal kingdom to provide prima facie evidence of its importance as a tool for analysing and interpreting the visual environment. The basic biological mechanisms on which vertebrate colour vision ultimately rests, the cone opsin genes and the photopigments they specify, are highly conserved. Within that constraint, however, the utilization of these basic elements varies in striking ways in that they appear, disappear and emerge in altered form during the course of evolution. These changes, along with other alterations in the visual system, have led to profound variations in the nature and salience of colour vision among the vertebrates. This article concerns the evolution of colour vision among the mammals, viewing that process in the context of relevant biological mechanisms, of variations in mammalian colour vision, and of the utility of colour vision. PMID:19720656

It is all in the face: carotenoid skin coloration loses attractiveness outside the face.

PubMed

Lefevre, C E; Ewbank, M P; Calder, A J; von dem Hagen, E; Perrett, D I

2013-01-01

Recently, the importance of skin colour for facial attractiveness has been recognized. In particular, dietary carotenoid-induced skin colour has been proposed as a signal of health and therefore attractiveness. While perceptual results are highly consistent, it is currently not clear whether carotenoid skin colour is preferred because it poses a cue to current health condition in humans or whether it is simply seen as a more aesthetically pleasing colour, independently of skin-specific signalling properties. Here, we tested this question by comparing attractiveness ratings of faces to corresponding ratings of meaningless scrambled face images matching the colours and contrasts found in the face. We produced sets of face and non-face stimuli with either healthy (high-carotenoid coloration) or unhealthy (low-carotenoid coloration) colour and asked participants for attractiveness ratings. Results showed that, while for faces increased carotenoid coloration significantly improved attractiveness, there was no equivalent effect on perception of scrambled images. These findings are consistent with a specific signalling system of current condition through skin coloration in humans and indicate that preferences are not caused by sensory biases in observers.

Synthetic food colours in saffron solutions, saffron rice and saffron chicken from restaurants in Tehran, Iran.

PubMed

Moradi-Khatoonabadi, Zhila; Amirpour, Mansooreh; AkbariAzam, Maryam

2015-01-01

Saffron solutions, saffron rice and saffron chicken samples were considered for synthetic colours as additives, which are forbidden according to Iranian national standards. Samples were taken from restaurants of three locations and analysed by high-performance liquid chromatography. Of the total 573 samples, 52% were positive for at least one colour. The most prevalent colours were Tartrazine, Quinoline Yellow and Sunset Yellow, with 44%, 9.1% and 8.4% of the samples testing positive for these colours, respectively. Carmoisine and Ponceau were both detected only in 0.5% of the positive samples and found only in saffron solution. In conclusion, synthetic food colours, especially Tartrazine should be regarded as a potential risk in saffron and its related food. Therefore, new attempts for food safety and quality should be undertaken to eliminate the use of these colours in restaurants.

Laser-induced plasmonic colours on metals

NASA Astrophysics Data System (ADS)

Guay, Jean-Michel; Calà Lesina, Antonino; Côté, Guillaume; Charron, Martin; Poitras, Daniel; Ramunno, Lora; Berini, Pierre; Weck, Arnaud

2017-07-01

Plasmonic resonances in metallic nanoparticles have been used since antiquity to colour glasses. The use of metal nanostructures for surface colourization has attracted considerable interest following recent developments in plasmonics. However, current top-down colourization methods are not ideally suited to large-scale industrial applications. Here we use a bottom-up approach where picosecond laser pulses can produce a full palette of non-iridescent colours on silver, gold, copper and aluminium. We demonstrate the process on silver coins weighing up to 5 kg and bearing large topographic variations (~1.5 cm). We find that colours are related to a single parameter, the total accumulated fluence, making the process suitable for high-throughput industrial applications. Statistical image analyses of laser-irradiated surfaces reveal various nanoparticle size distributions. Large-scale finite-difference time-domain computations based on these nanoparticle distributions reproduce trends seen in reflectance measurements, and demonstrate the key role of plasmonic resonances in colour formation.

Laser-induced plasmonic colours on metals

PubMed Central

Guay, Jean-Michel; Calà Lesina, Antonino; Côté, Guillaume; Charron, Martin; Poitras, Daniel; Ramunno, Lora; Berini, Pierre; Weck, Arnaud

2017-01-01

Plasmonic resonances in metallic nanoparticles have been used since antiquity to colour glasses. The use of metal nanostructures for surface colourization has attracted considerable interest following recent developments in plasmonics. However, current top-down colourization methods are not ideally suited to large-scale industrial applications. Here we use a bottom-up approach where picosecond laser pulses can produce a full palette of non-iridescent colours on silver, gold, copper and aluminium. We demonstrate the process on silver coins weighing up to 5 kg and bearing large topographic variations (∼1.5 cm). We find that colours are related to a single parameter, the total accumulated fluence, making the process suitable for high-throughput industrial applications. Statistical image analyses of laser-irradiated surfaces reveal various nanoparticle size distributions. Large-scale finite-difference time-domain computations based on these nanoparticle distributions reproduce trends seen in reflectance measurements, and demonstrate the key role of plasmonic resonances in colour formation. PMID:28719576

Effects of radio frequency and high pressure steam sterilisation on the colour and flavour of prepared Nostoc sphaeroides.

PubMed

Xu, Jicheng; Zhang, Min; An, Yanjun; Roknul, Azam Sm; Adhikari, Benu

2018-03-01

Nostoc sphaeroides has been used as a highly effective herbal medicine and dietary supplement for thousands of years. The desired dark green colour of fresh N. sphaeroides is converted into an undesirable dark brown during conventional high pressure (HP) steam sterilisation. Radio frequency (RF) sterilisation technology was used in this study to determine its effectiveness in sterilising N. sphaeroides and to achieve better preservation of natural colour and desirable flavour. Sterilisation was carried out using a 6 kW, 27 MHz RF instrument for 10, 20 and 30 min. The degree of microbial kill and the effects of RF sterilisation on colour and flavour were determined and compared with those obtained from HP steam (121 °C, 30 min) sterilisation. The effects of RF sterilisation on colour and flavour (measured using electronic nose) parameters were significantly lower than that in HP steam sterilisation. The RF sterilisation carried out for 20 min achieved logarithmic reduction of bacterial population and met China's national standard while preserving the colour and flavour better. Results of the present study indicated that application of RF sterilisation would improve the quality of sterilised N. sphaeroides and broaden its application in the food and health food industries. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Skin colour assessment of replanted fingers in digital images and its reliability for the incorporation of images in nursing progress notes.

PubMed

Terashima, Taiko; Yoshimura, Sadako

2018-03-01

To determine whether nurses can accurately assess the skin colour of replanted fingers displayed as digital images on a computer screen. Colour measurement and clinical diagnostic methods for medical digital images have been studied, but reproducing skin colour on a computer screen remains difficult. The inter-rater reliability of skin colour assessment scores was evaluated. In May 2014, 21 nurses who worked on a trauma ward in Japan participated in testing. Six digital images with different skin colours were used. Colours were scored from both digital images and direct patient's observation. The score from a digital image was defined as the test score, and its difference from the direct assessment score as the difference score. Intraclass correlation coefficients were calculated. Nurses' opinions were classified and summarised. The intraclass correlation coefficients for the test scores were fair. Although the intraclass correlation coefficients for the difference scores were poor, they improved to good when three images that might have contributed to poor reliability were excluded. Most nurses stated that it is difficult to assess skin colour in digital images; they did not think it could be a substitute for direct visual assessment. However, most nurses were in favour of including images in nursing progress notes. Although the inter-rater reliability was fairly high, the reliability of colour reproduction in digital images as indicated by the difference scores was poor. Nevertheless, nurses expect the incorporation of digital images in nursing progress notes to be useful. This gap between the reliability of digital colour reproduction and nurses' expectations towards it must be addressed. High inter-rater reliability for digital images in nursing progress notes was not observed. Assessments of future improvements in colour reproduction technologies are required. Further digitisation and visualisation of nursing records might pose challenges. © 2017 John Wiley & Sons Ltd.

Satisfaction with appearance and the desired treatment to improve aesthetics.

PubMed

Al-Zarea, Bader K

2013-01-01

Objective. To identify participants' satisfaction with appearance and the desired treatment to improve aesthetics. Materials and Methods. 220 participants (127 males and 93 females, mean age = 21.4 ± 1.5 years) were recruited into the study. A structured questionnaire was used to assess patients' satisfaction with appearance and what treatment they desire to improve aesthetics. Participants scored the level of satisfaction with appearance using visual analogue scale. Results. The VAS mean score of satisfaction with general appearance was 6.8 ± 2.3. Half participants were dissatisfied with tooth appearance and 65.9% were dissatisfied with tooth colour. Higher VAS scores were associated with higher desire for all treatments that improve tooth appearance (P < .05). Dissatisfaction with tooth appearance increased with increased dissatisfaction with teeth colour, feeling of poor tooth alignment, presence of fractured anterior teeth, and increased desire for orthodontic, crowns, and dentures treatments (P < .05). Dissatisfaction with tooth colour was associated with increased desire for tooth whitening and tooth coloured fillings (P < .05). Conclusions. Participants had high levels of dissatisfaction with tooth appearance and tooth colour. Dissatisfaction with tooth colour contributed to the increased dissatisfaction with tooth appearance. Dissatisfaction with tooth appearance, colour, alignment, and condition was significantly related to high desire for aesthetic treatments.

Organic-on-silicon complementary metal-oxide-semiconductor colour image sensors.

PubMed

Lim, Seon-Jeong; Leem, Dong-Seok; Park, Kyung-Bae; Kim, Kyu-Sik; Sul, Sangchul; Na, Kyoungwon; Lee, Gae Hwang; Heo, Chul-Joon; Lee, Kwang-Hee; Bulliard, Xavier; Satoh, Ryu-Ichi; Yagi, Tadao; Ro, Takkyun; Im, Dongmo; Jung, Jungkyu; Lee, Myungwon; Lee, Tae-Yon; Han, Moon Gyu; Jin, Yong Wan; Lee, Sangyoon

2015-01-12

Complementary metal-oxide-semiconductor (CMOS) colour image sensors are representative examples of light-detection devices. To achieve extremely high resolutions, the pixel sizes of the CMOS image sensors must be reduced to less than a micron, which in turn significantly limits the number of photons that can be captured by each pixel using silicon (Si)-based technology (i.e., this reduction in pixel size results in a loss of sensitivity). Here, we demonstrate a novel and efficient method of increasing the sensitivity and resolution of the CMOS image sensors by superposing an organic photodiode (OPD) onto a CMOS circuit with Si photodiodes, which consequently doubles the light-input surface area of each pixel. To realise this concept, we developed organic semiconductor materials with absorption properties selective to green light and successfully fabricated highly efficient green-light-sensitive OPDs without colour filters. We found that such a top light-receiving OPD, which is selective to specific green wavelengths, demonstrates great potential when combined with a newly designed Si-based CMOS circuit containing only blue and red colour filters. To demonstrate the effectiveness of this state-of-the-art hybrid colour image sensor, we acquired a real full-colour image using a camera that contained the organic-on-Si hybrid CMOS colour image sensor.

Organic-on-silicon complementary metal–oxide–semiconductor colour image sensors

PubMed Central

Lim, Seon-Jeong; Leem, Dong-Seok; Park, Kyung-Bae; Kim, Kyu-Sik; Sul, Sangchul; Na, Kyoungwon; Lee, Gae Hwang; Heo, Chul-Joon; Lee, Kwang-Hee; Bulliard, Xavier; Satoh, Ryu-Ichi; Yagi, Tadao; Ro, Takkyun; Im, Dongmo; Jung, Jungkyu; Lee, Myungwon; Lee, Tae-Yon; Han, Moon Gyu; Jin, Yong Wan; Lee, Sangyoon

2015-01-01

Complementary metal–oxide–semiconductor (CMOS) colour image sensors are representative examples of light-detection devices. To achieve extremely high resolutions, the pixel sizes of the CMOS image sensors must be reduced to less than a micron, which in turn significantly limits the number of photons that can be captured by each pixel using silicon (Si)-based technology (i.e., this reduction in pixel size results in a loss of sensitivity). Here, we demonstrate a novel and efficient method of increasing the sensitivity and resolution of the CMOS image sensors by superposing an organic photodiode (OPD) onto a CMOS circuit with Si photodiodes, which consequently doubles the light-input surface area of each pixel. To realise this concept, we developed organic semiconductor materials with absorption properties selective to green light and successfully fabricated highly efficient green-light-sensitive OPDs without colour filters. We found that such a top light-receiving OPD, which is selective to specific green wavelengths, demonstrates great potential when combined with a newly designed Si-based CMOS circuit containing only blue and red colour filters. To demonstrate the effectiveness of this state-of-the-art hybrid colour image sensor, we acquired a real full-colour image using a camera that contained the organic-on-Si hybrid CMOS colour image sensor. PMID:25578322

Tests of commercial colour CMOS cameras for astronomical applications

NASA Astrophysics Data System (ADS)

Pokhvala, S. M.; Reshetnyk, V. M.; Zhilyaev, B. E.

2013-12-01

We present some results of testing commercial colour CMOS cameras for astronomical applications. Colour CMOS sensors allow to perform photometry in three filters simultaneously that gives a great advantage compared with monochrome CCD detectors. The Bayer BGR colour system realized in colour CMOS sensors is close to the astronomical Johnson BVR system. The basic camera characteristics: read noise (e^{-}/pix), thermal noise (e^{-}/pix/sec) and electronic gain (e^{-}/ADU) for the commercial digital camera Canon 5D MarkIII are presented. We give the same characteristics for the scientific high performance cooled CCD camera system ALTA E47. Comparing results for tests of Canon 5D MarkIII and CCD ALTA E47 show that present-day commercial colour CMOS cameras can seriously compete with the scientific CCD cameras in deep astronomical imaging.

The unsuitability of html-based colour charts for estimating animal colours – a comment on Berggren and Merilä (2004)

PubMed Central

Stevens, Martin; Cuthill, Innes C

2005-01-01

Background A variety of techniques are used to study the colours of animal signals, including the use of visual matching to colour charts. This paper aims to highlight why they are generally an unsatisfactory tool for the measurement and classification of animal colours and why colour codes based on HTML (really RGB) standards, as advocated in a recent paper, are particularly inappropriate. There are many theoretical arguments against the use of colour charts, not least that human colour vision differs markedly from that of most other animals. However, the focus of this paper is the concern that, even when applied to humans, there is no simple 1:1 mapping from an RGB colour space to the perceived colours in a chart (the results are both printer- and illumination-dependent). We support our criticisms with data from colour matching experiments with humans, involving self-made, printed colour charts. Results Colour matching experiments with printed charts involving 11 subjects showed that the choices made by individuals were significantly different between charts that had exactly the same RGB values, but were produced from different printers. Furthermore, individual matches tended to vary under different lighting conditions. Spectrophotometry of the colour charts showed that the reflectance spectra of the charts varied greatly between printers and that equal steps in RGB space were often far from equal in terms of reflectance on the printed charts. Conclusion In addition to outlining theoretical criticisms of the use of colour charts, our empirical results show that: individuals vary in their perception of colours, that different printers produce strikingly different results when reproducing what should be the same chart, and that the characteristics of the light irradiating the surface do affect colour perception. Therefore, we urge great caution in the use of colour charts to study animal colour signals. They should be used only as a last resort and in full knowledge of their limitations, with specially produced charts made to high industry standards. PMID:16131394

Enhancing weak transient signals in SEVIRI false colour imagery: application to dust source detection in southern Africa

NASA Astrophysics Data System (ADS)

Murray, Jon E.; Brindley, Helen E.; Bryant, Robert G.; Russell, Jacqui E.; Jenkins, Katherine F.

2013-04-01

Understanding the processes governing the availability and entrainment of mineral dust into the atmosphere requires dust sources to be identified and the evolution of dust events to be monitored. To achieve this aim a wide range of approaches have been developed utilising observations from a variety of different satellite sensors. Global maps of source regions and their relative strengths have been derived from instruments in low Earth orbit (e.g. Total Ozone Monitoring Spectrometer (TOMS) (Prospero et al., 2002), MODerate resolution Imaging Spectrometer (MODIS) (Ginoux et al., 2012)). Instruments such as MODIS can also be used to improve precise source location (Baddock et al., 2009) but the information available is restricted to the satellite overpass times which may not be coincident with active dust emission from the source. Hence, at a regional scale, some of the more successful approaches used to characterise the activity of different sources use high temporal resolution data available from instruments in geostationary orbit. For example, the widely used red-green-blue (RGB) dust scheme developed by Lensky and Rosenfeld (2008) (hereafter LR2008) makes use of observations from selected thermal channels of the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) in a false colour rendering scheme in which dust appears pink. This scheme has provided the basis for numerous studies of north African dust sources and factors governing their activation (e.g. Schepanski et al., 2007, 2009, 2012). However, the LR2008 imagery can fail to identify dust events due to the effects of atmospheric moisture, variations in dust layer height and optical properties, and surface conditions (Brindley et al., 2012). Here we introduce a new method designed to circumvent some of these issues and enhance the signature of dust events using observations from SEVIRI. The approach involves the derivation of a composite clear-sky signal for selected channels on an individual time-step and pixel basis. These composite signals are subtracted from each observation in the relevant channels to enhance weak transient signals associated with low levels of dust emission. Different channel combinations are then rendered in false colour imagery to better identify dust source locations and activity. We have applied this new clear-sky difference (CSD) algorithm over three key source regions in southern Africa: the Makgadikgadi Basin, Etosha Pan, and the Namibian and western South African coast. Case studies indicate that advantages associated with the CSD approach include an improved ability to detect dust and distinguish multiple sources, the observation of source activation earlier in the diurnal cycle, and an improved ability to pinpoint dust source locations. These advantages are confirmed by a survey of four-years of data, comparing the results obtained using the CSD technique with those derived from LR2008 dust imagery. On average the new algorithm more than doubles the number of dust events identified, with the greatest improvement for the Makgadigkadi Basin and coastal regions. We anticipate exploiting this new activation record derived using the CSD approach to better understand the surface and meteorological conditions controlling dust uplift and subsequent atmospheric transport.

Processing speed can monitor stimulant-medication effects in adults with attention deficit disorder with hyperactivity.

PubMed

Nielsen, Niels Peter; Wiig, Elisabeth H; Bäck, Svante; Gustafsson, Jan

2017-05-01

Treatment responses to methylphenidate by adults with ADHD are generally monitored against DSM-IV/DSM-V symptomatology, rating scales or interviews during reviews. To evaluate the use of single- and dual-dimension processing-speed and efficiency measures to monitor the effects of pharmacological treatment with methylphenidate after a short period off medication. A Quick Test of Cognitive Speed (AQT) monitored the effects of immediate-release methylphenidate in 40 previously diagnosed and medicated adults with ADHD. Processing speed was evaluated with prior prescription medication, without medication after a 2-day period off ADHD medication, and with low-dose (10/20 mg) and high-dose (20/40 mg) methylphenidate hydrochloride (Medikinet IR). Thirty-three participants responded to the experimental treatments. One-way ANOVA with post-hoc analysis (Scheffe) indicated significant main effects for single dimension colour and form and dual-dimension colour-form naming. Post-hoc analysis indicated statistical differences between the no- and high-dose medication conditions for colour and form, measures of perceptual speed. For colour-form naming, a measure of cognitive speed, there was a significant difference between no- and low-dose medication and between no- and high-dose medications, but not between low- and high-dose medications. Results indicated that the AQT tests effectively monitored incremental effects of the methylphenidate dose on processing speed after a 2-day period off medication. Thus, perceptual (colour and form) and cognitive speed (two-dimensional colour-form naming) and processing efficiency (lowered shift costs) increased measurably with high-dose medication. These preliminary findings warrant validation with added measures of associated behavioural and cognitive changes.

Divergence in cryptic leaf colour provides local camouflage in an alpine plant.

PubMed

Niu, Yang; Chen, Zhe; Stevens, Martin; Sun, Hang

2017-10-11

The efficacy of camouflage through background matching is highly environment-dependent, often resulting in intraspecific colour divergence in animals to optimize crypsis in different visual environments. This phenomenon is largely unexplored in plants, although several lines of evidence suggest they do use crypsis to avoid damage by herbivores. Using Corydalis hemidicentra, an alpine plant with cryptic leaf colour, we quantified background matching between leaves and surrounding rocks in five populations based on an approximate model of their butterfly enemy's colour perception. We also investigated the pigment basis of leaf colour variation and the association between feeding risk and camouflage efficacy. We show that plants exhibit remarkable colour divergence between populations, consistent with differences in rock appearances. Leaf colour varies because of a different quantitative combination of two basic pigments-chlorophyll and anthocyanin-plus different air spaces. As expected, leaf colours are better matched against their native backgrounds than against foreign ones in the eyes of the butterfly. Furthermore, improved crypsis tends to be associated with a higher level of feeding risk. These results suggest that divergent cryptic leaf colour may have evolved to optimize local camouflage in various visual environments, extending our understanding of colour evolution and intraspecific phenotype diversity in plants. © 2017 The Author(s).

Attentional load attenuates synaesthetic priming effects in grapheme-colour synaesthesia.

PubMed

Mattingley, Jason B; Payne, Jonathan M; Rich, Anina N

2006-02-01

One of the hallmarks of grapheme-colour synaesthesia is that colours induced by letters, digits and words tend to interfere with the identification of coloured targets when the two colours are different, i.e., when they are incongruent. In a previous investigation (Mattingley et al., 2001) we found that this synaesthetic congruency effect occurs when an achromatic-letter prime precedes a coloured target, but that the effect disappears when the letter is pattern masked to prevent conscious recognition of its identity. Here we investigated whether selective attention modulates the synaesthetic congruency effect in a letter-priming task. Fourteen grapheme-colour synaesthetes and 14 matched, non-synaesthetic controls participated. The amount of selective attention available to process the letter-prime was limited by having participants perform a secondary visual task that involved discriminating pairs of gaps in adjacent limbs of a diamond surrounding the prime. In separate blocks of trials the attentional load of the secondary task was systematically varied to yield 'low load' and 'high load' conditions. We found a significant congruency effect for synaesthetes, but not for controls, when they performed a secondary attention-demanding task during presentation of the letter prime. Crucially, however, the magnitude of this priming was significantly reduced under conditions of high-load relative to low-load, indicating that attention plays an important role in modulating synaesthesia. Our findings help to explain the observation that synaesthetic colour experiences are often weak or absent during attention-demanding tasks.

Behavioural evidence of colour vision in free flying stingless bees.

PubMed

Spaethe, J; Streinzer, M; Eckert, J; May, S; Dyer, A G

2014-06-01

Colour vision was first demonstrated with behavioural experiments in honeybees 100 years ago. Since that time a wealth of quality physiological data has shown a highly conserved set of trichromatic colour receptors in most bee species. Despite the subsequent wealth of behavioural research on honeybees and bumblebees, there currently is a relative dearth of data on stingless bees, which are the largest tribe of the eusocial bees comprising of more than 600 species. In our first experiment we tested Trigona cf. fuscipennis, a stingless bee species from Costa Rica in a field setting using the von Frisch method and show functional colour vision. In a second experiment with these bees, we use a simultaneous colour discrimination test designed for honeybees to enable a comparative analysis of relative colour discrimination. In a third experiment, we test in laboratory conditions Tetragonula carbonaria, an Australian stingless bee species using a similar simultaneous colour discrimination test. Both stingless bee species show relatively poorer colour discrimination compared to honeybees and bumblebees; and we discuss the value of being able to use these behavioural methods to efficiently extend our current knowledge of colour vision and discrimination in different bee species.

Reversible colour change in Arthropoda.

PubMed

Umbers, Kate D L; Fabricant, Scott A; Gawryszewski, Felipe M; Seago, Ainsley E; Herberstein, Marie E

2014-11-01

The mechanisms and functions of reversible colour change in arthropods are highly diverse despite, or perhaps due to, the presence of an exoskeleton. Physiological colour changes, which have been recorded in 90 arthropod species, are rapid and are the result of changes in the positioning of microstructures or pigments, or in the refractive index of layers in the integument. By contrast, morphological colour changes, documented in 31 species, involve the anabolism or catabolism of components (e.g. pigments) directly related to the observable colour. In this review we highlight the diversity of mechanisms by which reversible colour change occurs and the evolutionary context and diversity of arthropod taxa in which it has been observed. Further, we discuss the functions of reversible colour change so far proposed, review the limited behavioural and ecological data, and argue that the field requires phylogenetically controlled approaches to understanding the evolution of reversible colour change. Finally, we encourage biologists to explore new model systems for colour change and to engage scientists from other disciplines; continued cross-disciplinary collaboration is the most promising approach to this nexus of biology, physics, and chemistry. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

Adaptive Colour Contrast Coding in the Salamander Retina Efficiently Matches Natural Scene Statistics

PubMed Central

Vasserman, Genadiy; Schneidman, Elad; Segev, Ronen

2013-01-01

The visual system continually adjusts its sensitivity to the statistical properties of the environment through an adaptation process that starts in the retina. Colour perception and processing is commonly thought to occur mainly in high visual areas, and indeed most evidence for chromatic colour contrast adaptation comes from cortical studies. We show that colour contrast adaptation starts in the retina where ganglion cells adjust their responses to the spectral properties of the environment. We demonstrate that the ganglion cells match their responses to red-blue stimulus combinations according to the relative contrast of each of the input channels by rotating their functional response properties in colour space. Using measurements of the chromatic statistics of natural environments, we show that the retina balances inputs from the two (red and blue) stimulated colour channels, as would be expected from theoretical optimal behaviour. Our results suggest that colour is encoded in the retina based on the efficient processing of spectral information that matches spectral combinations in natural scenes on the colour processing level. PMID:24205373

Iridescent colour production in hairs of blind golden moles (Chrysochloridae).

PubMed

Snyder, Holly K; Maia, Rafael; D'Alba, Liliana; Shultz, Allison J; Rowe, Karen M C; Rowe, Kevin C; Shawkey, Matthew D

2012-06-23

Relative to other metazoans, the mammalian integument is thought to be limited in colour. In particular, while iridescence is widespread among birds and arthropods, it has only rarely been reported in mammals. Here, we examine the colour, morphology and optical mechanisms in hairs from four species of golden mole (Mammalia: Chrysochloridae) that are characterized by sheens ranging from purple to green. Microspectrophotometry reveals that this colour is weak and variable. Iridescent hairs are flattened and have highly reduced cuticular scales, providing a broad and smooth surface for light reflection. These scales form multiple layers of light and dark materials of consistent thickness, strikingly similar to those in the elytra of iridescent beetles. Optical modelling suggests that the multi-layers produce colour through thin-film interference, and that the sensitivity of this mechanism to slight changes in layer thickness and number explains colour variability. While coloured integumentary structures are typically thought to evolve as sexual ornaments, the blindness of golden moles suggests that the colour may be an epiphenomenon resulting from evolution via other selective factors, including the ability to move and keep clean in dirt and sand.

Tunable white light of a Ce3+,Tb3+,Mn2+ triply doped Na2Ca3Si2O8 phosphor for high colour-rendering white LED applications: tunable luminescence and energy transfer.

PubMed

Lü, Wei; Xu, Huawei; Huo, Jiansheng; Shao, Baiqi; Feng, Yang; Zhao, Shuang; You, Hongpeng

2017-07-18

A tunable white light emitting Na 2 Ca 3 Si 2 O 8 :Ce 3+ ,Tb 3+ ,Mn 2+ phosphor with a high color rendering index (CRI) has been prepared. Under UV excitation, Na 2 Ca 3 Si 2 O 8 :Ce 3+ phosphors present blue luminescence and exhibit a broad excitation ranging from 250 to 400 nm. When codoping Tb 3+ /Mn 2+ ions into Na 2 Ca 3 Si 2 O 8 , energy transfer from Ce 3+ to Tb 3+ and Ce 3+ to Mn 2+ ions is observed from the spectral overlap between Ce 3+ emission and Tb 3+ /Mn 2+ excitation spectra. The energy-transfer efficiencies and corresponding mechanisms are discussed in detail. The mechanism of energy transfer from Ce 3+ to Tb 3+ is demonstrated to be a dipole-quadrupole mechanism by the Inokuti-Hirayama model. The wavelength-tunable white light can be realized by coupling the emission bands centered at 440, 550 and 590 nm ascribed to the contribution from Ce 3+ , Tb 3+ and Mn 2+ , respectively. The commission on illumination value of color tunable emission can be tuned by controlling the content of Ce 3+ , Tb 3+ and Mn 2+ . Temperature-dependent luminescence spectra proved the good thermal stability of the as-prepared phosphor. White LEDs with CRI = 93.5 are finally fabricated using a 365 nm UV chip and the as-prepared Na 2 Ca 3 Si 2 O 8 :Ce 3+ ,Tb 3+ ,Mn 2+ phosphor. All the results suggest that Na 2 Ca 3 Si 2 O 8 :Ce 3+ ,Tb 3+ ,Mn 2+ can act as potential color-tunable and single-phase white emission phosphors for possible applications in UV based white LEDs.

Limits of colour vision in dim light.

PubMed

Kelber, Almut; Lind, Olle

2010-09-01

Humans and most vertebrates have duplex retinae with multiple cone types for colour vision in bright light, and one single rod type for achromatic vision in dim light. Instead of comparing signals from multiple spectral types of photoreceptors, such species use one highly sensitive receptor type thus improving the signal-to-noise ratio at night. However, the nocturnal hawkmoth Deilephila elpenor, the nocturnal bee Xylocopa tranquebarica and the nocturnal gecko Tarentola chazaliae can discriminate colours at extremely dim light intensities. To be able to do so, they sacrifice spatial and temporal resolution in favour of colour vision. We review what is known about colour vision in dim light, and compare colour vision thresholds with the optical sensitivity of the photoreceptors in selected animal species with lens and compound eyes. © 2010 The Authors, Ophthalmic and Physiological Optics © 2010 The College of Optometrists.

Radiation resistant polypropylene blended with mobilizer,. antioxidants and nucleating agent

NASA Astrophysics Data System (ADS)

Shamshad, A.; Basfar, A. A.

2000-03-01

Post-irradiation storage of medical disposables prepared from isotactic polypropylene renders them brittle due to degradation. To avoid this, isotactic polypropylene [(is)PP] was blended with a mobilizer, dioctyl pthallate (DOP), three antioxidants (hindered amines and a secondary antioxidant) and benzoic acid to obtain radiation-resistant, thermally-stable and transparent material. Different formulations prepared were subjected to gamma radiation to doses of 25 and 50 kGy. Tests of breakage on bending after ageing in an oven at 70°C up to 12 months have shown that the addition of DOP and the antioxidants imparts improved radiation and thermal stability as compared to (is)PP alone or its blend with DOP. All the formulations irradiated or otherwise demonstrated excellent colour stability even after accelerated ageing at 70°C for prolonged periods.

Dissecting the mechanism of Solanum lycopersicum and Solanum chilense flower colour formation.

PubMed

Gao, M; Qu, H; Gao, L; Chen, L; Sebastian, R S J; Zhao, L

2015-01-01

Flowers are the defining feature of angiosperms, and function as indispensable organs for sexual reproduction. Flower colour typically plays an important role in attracting pollinators, and can show considerable variation, even between closely related species. For example, domesticated tomato (S. lycopersicum) has orange/yellow flowers, while the wild relative S. chilense (accession LA2405) has bright yellow flowers. In this study, the mechanism of flower colour formation in these two species was compared by evaluating the accumulation of carotenoids, assessing the expression genes related to carotenoid biosynthetic pathways and observing chromoplast ultrastructure. In S. chilense petals, genes associated with the lutein branch of the carotenoid biosynthetic pathway, phytoene desaturase (PDS), ζ-carotene desaturase (ZDS), lycopene β-cyclase (LCY-B), β-ring hydroxylase (CRTR-B) and ε-ring hydroxylase (CRTR-E), were highly expressed, and this was correlated with high levels of lutein accumulation. In contrast, PDS, ZDS and CYC-B from the neoxanthin biosynthetic branch were highly expressed in S. lycopersicum anthers, leading to increased β-carotene accumulation and hence an orange/yellow colour. Changes in the size, amount and electron density of plastoglobules in chromoplasts provided further evidence of carotenoid accumulation and flower colour formation. Taken together, these results reveal the biochemical basis of differences in carotenoid pigment accumulation and colour between petals and anthers in tomato. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

Textile wastewater treatment: colour and COD removal of reactive black-5 by ozonation

NASA Astrophysics Data System (ADS)

Suryawan, I. W. K.; Helmy, Q.; Notodarmojo, S.

2018-01-01

Textile industries produced a large amount of highly coloured wastewater containing variety of dyes in different concentrations. Due to the high concentration of organics in the effluents and the higher stability of modern synthetic dyes, the conventional biological treatment methods are ineffective for the complete colour removal and degradation of organics and dyes. On the other hand, physical-chemical treatment are not destructive, mainly just concentrate and separate the pollutants phases. This research paper investigates the removal of colour and chemical oxygen demand/COD from textile wastewater using ozone treatment. Varied ozone dosages of 1.16; 3.81; 18.79; and 40.88 mg/minute were used in the experiment. Varied wastewater containing Reactive Black 5 (RB-5) concentrations of 40 mg/L, 100 mg/L were also applied. Research result showed the highest colour removal efficiency of 96.9 % was achieved after 5 hours incubation time, while the highest COD removal efficiency of 77.5% was achieved after 2 hours incubation time.

Oculomotor capture by colour singletons depends on intertrial priming.

PubMed

Becker, Stefanie I

2010-10-12

In visual search, an irrelevant colour singleton captures attention when the colour of the distractor changes across trials (e.g., from red to green), but not when the colour remains constant (Becker, 2007). The present study shows that intertrial changes of the distractor colour also modulate oculomotor capture: an irrelevant colour singleton distractor was only selected more frequently than the inconspicuous nontargets (1) when its features had switched (compared to the previous trial), or (2) when the distractor had been presented at the same position as the target on the previous trial. These results throw doubt on the notion that colour distractors capture attention and the eyes because of their high feature contrast, which is available at an earlier point in time than information about specific feature values. Instead, attention and eye movements are apparently controlled by a system that operates on feature-specific information, and gauges the informativity of nominally irrelevant features. Copyright © 2010 Elsevier Ltd. All rights reserved.

Classification of pre-sliced pork and Turkey ham qualities based on image colour and textural features and their relationships with consumer responses.

PubMed

Iqbal, Abdullah; Valous, Nektarios A; Mendoza, Fernando; Sun, Da-Wen; Allen, Paul

2010-03-01

Images of three qualities of pre-sliced pork and Turkey hams were evaluated for colour and textural features to characterize and classify them, and to model the ham appearance grading and preference responses of a group of consumers. A total of 26 colour features and 40 textural features were extracted for analysis. Using Mahalanobis distance and feature inter-correlation analyses, two best colour [mean of S (saturation in HSV colour space), std. deviation of b*, which indicates blue to yellow in L*a*b* colour space] and three textural features [entropy of b*, contrast of H (hue of HSV colour space), entropy of R (red of RGB colour space)] for pork, and three colour (mean of R, mean of H, std. deviation of a*, which indicates green to red in L*a*b* colour space) and two textural features [contrast of B, contrast of L* (luminance or lightness in L*a*b* colour space)] for Turkey hams were selected as features with the highest discriminant power. High classification performances were reached for both types of hams (>99.5% for pork and >90.5% for Turkey) using the best selected features or combinations of them. In spite of the poor/fair agreement among ham consumers as determined by Kappa analysis (Kappa-value<0.4) for sensory grading (surface colour, colour uniformity, bitonality, texture appearance and acceptability), a dichotomous logistic regression model using the best image features was able to explain the variability of consumers' responses for all sensorial attributes with accuracies higher than 74.1% for pork hams and 83.3% for Turkey hams. Copyright 2009 Elsevier Ltd. All rights reserved.

Language use statistics and prototypical grapheme colours predict synaesthetes' and non-synaesthetes' word-colour associations.

PubMed

Goodhew, Stephanie C; Kidd, Evan

2017-02-01

Synaesthesia is the neuropsychological phenomenon in which individuals experience unusual sensory associations, such as experiencing particular colours in response to particular words. While it was once thought the particular pairings between stimuli were arbitrary and idiosyncratic to particular synaesthetes, there is now growing evidence for a systematic psycholinguistic basis to the associations. Here we sought to assess the explanatory value of quantifiable lexical association measures (via latent semantic analysis; LSA) in the pairings observed between words and colours in synaesthesia. To test this, we had synaesthetes report the particular colours they experienced in response to given concept words, and found that language association between the concept and colour words provided highly reliable predictors of the reported pairings. These results provide convergent evidence for a psycholinguistic basis to synaesthesia, but in a novel way, showing that exposure to particular patterns of associations in language can predict the formation of particular synaesthetic lexical-colour associations. Consistent with previous research, the prototypical synaesthetic colour for the first letter of the word also played a role in shaping the colour for the whole word, and this effect also interacted with language association, such that the effect of the colour for the first letter was stronger as the association between the concept word and the colour word in language increased. Moreover, when a group of non-synaesthetes were asked what colours they associated with the concept words, they produced very similar reports to the synaesthetes that were predicted by both language association and prototypical synaesthetic colour for the first letter of the word. This points to a shared linguistic experience generating the associations for both groups. Copyright © 2016 Elsevier B.V. All rights reserved.

Colour break in reverse bicolour daffodils is associated with the presence of Narcissus mosaic virus

PubMed Central

2011-01-01

Background Daffodils (Narcissus pseudonarcissus) are one of the world's most popular ornamentals. They also provide a scientific model for studying the carotenoid pigments responsible for their yellow and orange flower colours. In reverse bicolour daffodils, the yellow flower trumpet fades to white with age. The flowers of this type of daffodil are particularly prone to colour break whereby, upon opening, the yellow colour of the perianth is observed to be 'broken' into patches of white. This colour break symptom is characteristic of potyviral infections in other ornamentals such as tulips whose colour break is due to alterations in the presence of anthocyanins. However, reverse bicolour flowers displaying colour break show no other virus-like symptoms such as leaf mottling or plant stunting, leading some to argue that the carotenoid-based colour breaking in reverse bicolour flowers may not be caused by virus infection. Results Although potyviruses have been reported to cause colour break in other flower species, enzyme-linked-immunoassays with an antibody specific to the potyviral family showed that potyviruses were not responsible for the occurrence of colour break in reverse bicolour daffodils. Colour break in this type of daffodil was clearly associated with the presence of large quantities of rod-shaped viral particles of lengths 502-580 nm in tepals. Sap from flowers displaying colour break caused red necrotic lesions on Gomphrena globosa, suggesting the presence of potexvirus. Red necrotic lesions were not observed in this indicator plant when sap from reverse bicolour flowers not showing colour break was used. The reverse transcriptase polymerase reactions using degenerate primers to carla-, potex- and poty-viruses linked viral RNA with colour break and sequencing of the amplified products indicated that the potexvirus Narcissisus mosaic virus was the predominant virus associated with the occurrence of the colour break. Conclusions High viral counts were associated with the reverse bicolour daffodil flowers that were displaying colour break but otherwise showed no other symptoms of infection. Narcissus mosaic virus was the virus that was clearly linked to the carotenoid-based colour break. PMID:21854646

White organic light-emitting diodes with fluorescent tube efficiency.

PubMed

Reineke, Sebastian; Lindner, Frank; Schwartz, Gregor; Seidler, Nico; Walzer, Karsten; Lüssem, Björn; Leo, Karl

2009-05-14

The development of white organic light-emitting diodes (OLEDs) holds great promise for the production of highly efficient large-area light sources. High internal quantum efficiencies for the conversion of electrical energy to light have been realized. Nevertheless, the overall device power efficiencies are still considerably below the 60-70 lumens per watt of fluorescent tubes, which is the current benchmark for novel light sources. Although some reports about highly power-efficient white OLEDs exist, details about structure and the measurement conditions of these structures have not been fully disclosed: the highest power efficiency reported in the scientific literature is 44 lm W(-1) (ref. 7). Here we report an improved OLED structure which reaches fluorescent tube efficiency. By combining a carefully chosen emitter layer with high-refractive-index substrates, and using a periodic outcoupling structure, we achieve a device power efficiency of 90 lm W(-1) at 1,000 candelas per square metre. This efficiency has the potential to be raised to 124 lm W(-1) if the light outcoupling can be further improved. Besides approaching internal quantum efficiency values of one, we have also focused on reducing energetic and ohmic losses that occur during electron-photon conversion. We anticipate that our results will be a starting point for further research, leading to white OLEDs having efficiencies beyond 100 lm W(-1). This could make white-light OLEDs, with their soft area light and high colour-rendering qualities, the light sources of choice for the future.

Incorporating Colour Information for Computer-Aided Diagnosis of Melanoma from Dermoscopy Images: A Retrospective Survey and Critical Analysis

PubMed Central

Drew, Mark S.

2016-01-01

Cutaneous melanoma is the most life-threatening form of skin cancer. Although advanced melanoma is often considered as incurable, if detected and excised early, the prognosis is promising. Today, clinicians use computer vision in an increasing number of applications to aid early detection of melanoma through dermatological image analysis (dermoscopy images, in particular). Colour assessment is essential for the clinical diagnosis of skin cancers. Due to this diagnostic importance, many studies have either focused on or employed colour features as a constituent part of their skin lesion analysis systems. These studies range from using low-level colour features, such as simple statistical measures of colours occurring in the lesion, to availing themselves of high-level semantic features such as the presence of blue-white veil, globules, or colour variegation in the lesion. This paper provides a retrospective survey and critical analysis of contributions in this research direction. PMID:28096807

Directional Limits on Motion Transparency Assessed Through Colour-Motion Binding.

PubMed

Maloney, Ryan T; Clifford, Colin W G; Mareschal, Isabelle

2018-03-01

Motion-defined transparency is the perception of two or more distinct moving surfaces at the same retinal location. We explored the limits of motion transparency using superimposed surfaces of randomly positioned dots defined by differences in motion direction and colour. In one experiment, dots were red or green and we varied the proportion of dots of a single colour that moved in a single direction ('colour-motion coherence') and measured the threshold direction difference for discriminating between two directions. When colour-motion coherences were high (e.g., 90% of red dots moving in one direction), a smaller direction difference was required to correctly bind colour with direction than at low coherences. In another experiment, we varied the direction difference between the surfaces and measured the threshold colour-motion coherence required to discriminate between them. Generally, colour-motion coherence thresholds decreased with increasing direction differences, stabilising at direction differences around 45°. Different stimulus durations were compared, and thresholds were higher at the shortest (150 ms) compared with the longest (1,000 ms) duration. These results highlight different yet interrelated aspects of the task and the fundamental limits of the mechanisms involved: the resolution of narrowly separated directions in motion processing and the local sampling of dot colours from each surface.

Effects of surface inactivation, high temperature drying and preservative treatment on surface roughness and colour of alder and beech wood

NASA Astrophysics Data System (ADS)

Aydin, Ismail; Colakoglu, Gursel

2005-10-01

Although extensive research has been conducted in wood surface quality analysis, a unified approach to surface quality characterisation does not exist. Measurements of the variation in surface roughness and surface colour are used widely for the evaluation of wood surface quality. Colour is a basic visual feature for wood and wood-based products. Colour measurement is one of the quality control tests that should be carried out because the colour deviations are spotted easily by the consumers. On the other hand, a common problem faced by plywood manufacturers is panel delamination, for which a major cause is poor quality glue-bonds resulting from rough veneer. Rotary cut veneers with dimensions of 500 mm × 500 mm × 2 mm manufactured from alder ( Alnus glutinosa subsp. barbata) and beech ( Fagus orientalis Lipsky) logs were used as materials in this study. Veneer sheets were oven-dried in a veneer dryer at 110 °C (normal drying temperature) and 180 °C (high drying temperature) after peeling process. The surfaces of some veneers were then exposed at indoor laboratory conditions to obtain inactive wood surfaces for glue bonds, and some veneers were treated with borax, boric acid and ammonium acetate solutions. After these treatments, surface roughness and colour measurements were made on veneer surfaces. High temperature drying process caused a darkening on the surfaces of alder and beech veneers. Total colour change value (Δ E*) increased linear with increasing exposure time. Among the treatment solutions, ammonium acetate caused the biggest colour change while treatment with borax caused the lowest changes in Δ E* values. Considerable changes in surface roughness after preservative treatment did not occur on veneer surfaces. Generally, no clear changes were obtained or the values mean roughness profile ( Ra) decreased slightly in Ra values after the natural inactivation process.

Global skin colour prediction from DNA.

PubMed

Walsh, Susan; Chaitanya, Lakshmi; Breslin, Krystal; Muralidharan, Charanya; Bronikowska, Agnieszka; Pospiech, Ewelina; Koller, Julia; Kovatsi, Leda; Wollstein, Andreas; Branicki, Wojciech; Liu, Fan; Kayser, Manfred

2017-07-01

Human skin colour is highly heritable and externally visible with relevance in medical, forensic, and anthropological genetics. Although eye and hair colour can already be predicted with high accuracies from small sets of carefully selected DNA markers, knowledge about the genetic predictability of skin colour is limited. Here, we investigate the skin colour predictive value of 77 single-nucleotide polymorphisms (SNPs) from 37 genetic loci previously associated with human pigmentation using 2025 individuals from 31 global populations. We identified a minimal set of 36 highly informative skin colour predictive SNPs and developed a statistical prediction model capable of skin colour prediction on a global scale. Average cross-validated prediction accuracies expressed as area under the receiver-operating characteristic curve (AUC) ± standard deviation were 0.97 ± 0.02 for Light, 0.83 ± 0.11 for Dark, and 0.96 ± 0.03 for Dark-Black. When using a 5-category, this resulted in 0.74 ± 0.05 for Very Pale, 0.72 ± 0.03 for Pale, 0.73 ± 0.03 for Intermediate, 0.87±0.1 for Dark, and 0.97 ± 0.03 for Dark-Black. A comparative analysis in 194 independent samples from 17 populations demonstrated that our model outperformed a previously proposed 10-SNP-classifier approach with AUCs rising from 0.79 to 0.82 for White, comparable at the intermediate level of 0.63 and 0.62, respectively, and a large increase from 0.64 to 0.92 for Black. Overall, this study demonstrates that the chosen DNA markers and prediction model, particularly the 5-category level; allow skin colour predictions within and between continental regions for the first time, which will serve as a valuable resource for future applications in forensic and anthropologic genetics.

SVGenes: a library for rendering genomic features in scalable vector graphic format.

PubMed

Etherington, Graham J; MacLean, Daniel

2013-08-01

Drawing genomic features in attractive and informative ways is a key task in visualization of genomics data. Scalable Vector Graphics (SVG) format is a modern and flexible open standard that provides advanced features including modular graphic design, advanced web interactivity and animation within a suitable client. SVGs do not suffer from loss of image quality on re-scaling and provide the ability to edit individual elements of a graphic on the whole object level independent of the whole image. These features make SVG a potentially useful format for the preparation of publication quality figures including genomic objects such as genes or sequencing coverage and for web applications that require rich user-interaction with the graphical elements. SVGenes is a Ruby-language library that uses SVG primitives to render typical genomic glyphs through a simple and flexible Ruby interface. The library implements a simple Page object that spaces and contains horizontal Track objects that in turn style, colour and positions features within them. Tracks are the level at which visual information is supplied providing the full styling capability of the SVG standard. Genomic entities like genes, transcripts and histograms are modelled in Glyph objects that are attached to a track and take advantage of SVG primitives to render the genomic features in a track as any of a selection of defined glyphs. The feature model within SVGenes is simple but flexible and not dependent on particular existing gene feature formats meaning graphics for any existing datasets can easily be created without need for conversion. The library is provided as a Ruby Gem from https://rubygems.org/gems/bio-svgenes under the MIT license, and open source code is available at https://github.com/danmaclean/bioruby-svgenes also under the MIT License. dan.maclean@tsl.ac.uk.

MTO-like reference mask modeling for advanced inverse lithography technology patterns

NASA Astrophysics Data System (ADS)

Park, Jongju; Moon, Jongin; Son, Suein; Chung, Donghoon; Kim, Byung-Gook; Jeon, Chan-Uk; LoPresti, Patrick; Xue, Shan; Wang, Sonny; Broadbent, Bill; Kim, Soonho; Hur, Jiuk; Choo, Min

2017-07-01

Advanced Inverse Lithography Technology (ILT) can result in mask post-OPC databases with very small address units, all-angle figures, and very high vertex counts. This creates mask inspection issues for existing mask inspection database rendering. These issues include: large data volumes, low transfer rate, long data preparation times, slow inspection throughput, and marginal rendering accuracy leading to high false detections. This paper demonstrates the application of a new rendering method including a new OASIS-like mask inspection format, new high-speed rendering algorithms, and related hardware to meet the inspection challenges posed by Advanced ILT masks.

Porphyrins produce uniquely ephemeral animal colouration: a possible signal of virginity

NASA Astrophysics Data System (ADS)

Galván, Ismael; Camarero, Pablo R.; Mateo, Rafael; Negro, Juan J.

2016-12-01

Colours that underlie animal pigmentation can either be permanent or renewable in the short term. Here we describe the discovery of a conspicuous salmon-pink colouration in the base of bustard feathers and down that has never been reported because of its extraordinarily brief expression. HPLC analyses indicated that its constituent pigments are coproporphyrin III and protoporphyrin IX, which are prone to photodegradation. Accordingly, an experimental exposure of feathers of three bustard species to sunlight produced a rapid disappearance of the salmon-pink colouration, together with a marked decrease in reflectance around 670 nm coinciding with the absorption of porphyrin photoproducts. The disappearance of the salmon-pink colouration can occur in a period as short as 12 min, likely making it the most ephemeral colour phenotype in any extant bird. The presence of this colour trait in males performing sexual displays may thus indicate to females a high probability that the males were performing their first displays and would engage in their first copulations in the breeding season. In dominant males, sperm quality decreases over successive copulations, thus porphyrin-based colouration may evolve as a signal of virginity that allows females to maximize their fitness in lek mating systems.

Optical Addressing of Multi-Colour Photochromic Material Mixture for Volumetric Display.

PubMed

Hirayama, Ryuji; Shiraki, Atsushi; Naruse, Makoto; Nakamura, Shinichiro; Nakayama, Hirotaka; Kakue, Takashi; Shimobaba, Tomoyoshi; Ito, Tomoyoshi

2016-08-16

This is the first study to demonstrate that colour transformations in the volume of a photochromic material (PM) are induced at the intersections of two control light channels, one controlling PM colouration and the other controlling decolouration. Thus, PM colouration is induced by position selectivity, and therefore, a dynamic volumetric display may be realised using these two control lights. Moreover, a mixture of multiple PM types with different absorption properties exhibits different colours depending on the control light spectrum. Particularly, the spectrum management of the control light allows colour-selective colouration besides position selectivity. Therefore, a PM-based, full-colour volumetric display is realised. We experimentally construct a mixture of two PM types and validate the operating principles of such a volumetric display system. Our system is constructed simply by mixing multiple PM types; therefore, the display hardware structure is extremely simple, and the minimum size of a volume element can be as small as the size of a molecule. Volumetric displays can provide natural three-dimensional (3D) perception; therefore, the potential uses of our system include high-definition 3D visualisation for medical applications, architectural design, human-computer interactions, advertising, and entertainment.

Optical Addressing of Multi-Colour Photochromic Material Mixture for Volumetric Display

NASA Astrophysics Data System (ADS)

Hirayama, Ryuji; Shiraki, Atsushi; Naruse, Makoto; Nakamura, Shinichiro; Nakayama, Hirotaka; Kakue, Takashi; Shimobaba, Tomoyoshi; Ito, Tomoyoshi

2016-08-01

This is the first study to demonstrate that colour transformations in the volume of a photochromic material (PM) are induced at the intersections of two control light channels, one controlling PM colouration and the other controlling decolouration. Thus, PM colouration is induced by position selectivity, and therefore, a dynamic volumetric display may be realised using these two control lights. Moreover, a mixture of multiple PM types with different absorption properties exhibits different colours depending on the control light spectrum. Particularly, the spectrum management of the control light allows colour-selective colouration besides position selectivity. Therefore, a PM-based, full-colour volumetric display is realised. We experimentally construct a mixture of two PM types and validate the operating principles of such a volumetric display system. Our system is constructed simply by mixing multiple PM types; therefore, the display hardware structure is extremely simple, and the minimum size of a volume element can be as small as the size of a molecule. Volumetric displays can provide natural three-dimensional (3D) perception; therefore, the potential uses of our system include high-definition 3D visualisation for medical applications, architectural design, human-computer interactions, advertising, and entertainment.

Colour blindness does not preclude fame as an artist: celebrated Australian artist Clifton Pugh was a protanope.

PubMed

Cole, Barry L; Harris, Ross W

2009-09-01

The aim was to make a posthumous diagnosis of the abnormal colour vision of the acclaimed artist Clifton Pugh and to analyse his use of colours to discern the strategies he used to overcome his limited colour perception. A pedigree of Pugh's family was constructed by searching public records. Pugh had no daughters but he had two older brothers, one of whom was still living. We tested the colour vision of this brother and one of his daughters and one of his grandsons. Three children of the other brother were questioned about the colour vision of their father and one daughter was tested for heterozygosity with the Medmont C100. Four observers with normal colour vision categorised the colours used by Pugh in a sample of 59 of his paintings. Protanopic transformations of some of these paintings were made using the Vischeck algorithms to gain an appreciation of how Pugh saw his own paintings. The validity of the transformations was tested by asking a protanope to report if the transformations looked the same as the normal colour images of 10 of Pugh's paintings. Pugh's brother was a severe protan. His daughter showed Schmidt's sign and was a carrier of the protan gene and her son was a protanope. The oldest brother was reported as having normal colour vision. Therefore, it is almost certain that Clifton Pugh was a protanope. Pugh used all colours in his paintings but preferred to structure them on brown, black and blue or, for high key paintings, on cream or flesh colours. He used greens and purples sparingly. The protanopic Vischeck transformations did not always look the same as the normal colour image for the protanope observer. A severe colour vision deficiency does not preclude success as a painter. It is a handicap but there are strategies artists can use to overcome it.

Calibration and characterisation of the Gaia Red Clump

NASA Astrophysics Data System (ADS)

Ruiz-Dern, L.; Babusiaux, C.; Arenou, F.; Danielski, C.; Turon, C.; Sartoretti, P.

2018-04-01

We present new empirical Colour-Colour and Effective Temperature-Colour Gaia Red Clump calibrations. The selected sample takes into account high photometric quality, good spectrometric metallicity, homogeneous effective temperatures and low interstellar extinctions. From those calibrations we developed a method to derive the absolute magnitude, temperature and extinction of the Gaia RC. We tested our colour and extinction estimates on stars with measured spectroscopic effective temperatures and Diffuse Interstellar Band (DIB) constraints. Within the Gaia Validation team these calibrations are also being used, together with asteroseismic constraints, to check the parallax zero-point with Red Clump stars.

Correlation of natural tooth colour with aging in the Spanish population.

PubMed

Gómez Polo, Cristina; Gómez Polo, Miguel; Montero, Javier; Martínez Vazquez De Parga, Juan Antonio; Celemin Viñuela, Alicia

2015-10-01

To analyse natural tooth colour in the Spanish population according to the colour coordinates lightness (L*), chroma (C*), hue (h*), red-green axis (a*) and yellow-blue axis (b*) in order to quantify the correlation and changes of tooth colour with age and sex. Natural tooth colour was measured in a sample of 1,361 Spanish participants of both sexes distributed within an age range of 16 to 89 years. The Easyshade Compact spectrophotometer was used and the CIELAB and CIELCh systems were followed. Pearson's bivariate correlations between age and colour coordinates were highly significant for L* (r=-0.674, P≤0.001), h* (r=-0.468, P≤0.001) and C* (r=0.417, P≤0.001). The correlation between age and colour coordinates was stronger for men than for women, for all colour coordinates. The results showed that C*, b* and a* increased by 0.60, 0.56 and 0.26 units/year on average, respectively, whereas L* and h* decreased progressively with age (by 0.60 units/year, on average), and colour differences increased in a systematic way as the gap between the ages being compared grew wider. The strongest correlation was found between age and L*, then between age and h* (both inverse relationships) and then between age and a*, C* and b* (direct relationships). In addition, a similar degree of change in the colour coordinates L*, C* and h* (of 0.60 units/year on average) was observed for natural tooth colour. Knowledge of the chromatic range of natural teeth may help to choose colour for the replacement of missing elements. © 2015 FDI World Dental Federation.

Blue-yellow colour vision impairment and cognitive deficits in occasional and dependent stimulant users.

PubMed

Hulka, Lea M; Wagner, Michael; Preller, Katrin H; Jenni, Daniela; Quednow, Boris B

2013-04-01

Specific blue-yellow colour vision impairment has been reported in dependent cocaine users and it was postulated that drug-induced changes in retinal dopamine neurotransmission are responsible. However, it is unclear whether these changes are confined to chronic cocaine users, whether they are specific for dopaminergic stimulants such as cocaine and amphetamine and whether they are related to cognitive functions such as working memory, encoding and consolidation. In 47 occasional and 29 dependent cocaine users, 23 MDMA (commonly known as 'ecstasy') users and 47 stimulant-naive controls, colour vision discrimination was measured with the Lanthony Desaturated Panel D-15 Test and memory performance with the Auditory Verbal Learning Test. Both occasional and dependent cocaine users showed higher colour confusion indices than controls. Users of the serotonergic stimulant MDMA (26%), occasional (30%) and dependent cocaine users (34%) exhibited more frequent blue-yellow colour vision disorders compared to controls (9%). Inferior performance of MDMA users was caused by a subgroup with high amphetamine co-use (55%), while MDMA use alone was not associated with decreased blue-yellow discrimination (0%). Cognitive performance was worse in cocaine users with colour vision disorder compared to users and controls with intact colour vision and both colour vision impairment and cognitive deficits were related to cocaine use. Occasional cocaine and amphetamine use might induce blue-yellow colour vision impairment, whereas the serotonergic stimulant MDMA does not impair colour vision. The association between colour vision impairment and cognitive deficits in cocaine users may reflect that retinal and cerebral dopamine alterations are linked to a certain degree.

Colour and stability assessment of blue ferric anthocyanin chelates in liquid pectin-stabilised model systems.

PubMed

Buchweitz, M; Brauch, J; Carle, R; Kammerer, D R

2013-06-01

The formation of blue coloured ferric anthocyanin chelates and their colour stability during storage and thermal treatment were monitored in a pH range relevant to food (3.6-5.0). Liquid model systems were composed of different types of Citrus pectins, juices (J) and the respective phenolic extracts (E) from elderberry (EB), black currant (BC), red cabbage (RC) and purple carrot (PC) in the presence of ferric ions. For EB, BC and PC, pure blue colours devoid of a violet tint were exclusively observed for the phenolic extracts and at pH values ≥ 4.5 in model systems containing high methoxylated and amidated pectins, respectively. Colour and its stability strongly depended on the amount of ferric ions and the plant source; however, colour decay could generally be described as a pseudo-first-order kinetics. Despite optimal colour hues for RC-E and RC-J, storage and heat stabilities were poor. Highest colour intensities and best stabilities were observed for model systems containing PC-E at a molar anthocyanin:ferric ion ratio of 1:2. Ascorbic and lactic acids interfered with ferric ions, thus significantly affecting blue colour evolution and stability. Colour loss strongly depended on heat exposure with activation energies ranging between 60.5 and 78.4 kJ/mol. The comprehensive evaluation of the interrelationship of pigment source, pH conditions and pectin type on chelate formation and stability demonstrated that ferric anthocyanin chelates are promising natural blue food colourants. Copyright © 2012 Elsevier Ltd. All rights reserved.

Continuously Tunable, Polarization Controlled, Colour Palette Produced from Nanoscale Plasmonic Pixels.

PubMed

Balaur, Eugeniu; Sadatnajafi, Catherine; Kou, Shan Shan; Lin, Jiao; Abbey, Brian

2016-06-17

Colour filters based on nano-apertures in thin metallic films have been widely studied due to their extraordinary optical transmission and small size. These properties make them prime candidates for use in high-resolution colour displays and high accuracy bio-sensors. The inclusion of polarization sensitive plasmonic features in such devices allow additional control over the electromagnetic field distribution, critical for investigations of polarization induced phenomena. Here we demonstrate that cross-shaped nano-apertures can be used for polarization controlled color tuning in the visible range and apply fundamental theoretical models to interpret key features of the transmitted spectrum. Full color transmission was achieved by fine-tuning the periodicity of the apertures, whilst keeping the geometry of individual apertures constant. We demonstrate this effect for both transverse electric and magnetic fields. Furthermore we have been able to demonstrate the same polarization sensitivity even for nano-size, sub-wavelength sets of arrays, which is paramount for ultra-high resolution compact colour displays.

Continuously Tunable, Polarization Controlled, Colour Palette Produced from Nanoscale Plasmonic Pixels

PubMed Central

Balaur, Eugeniu; Sadatnajafi, Catherine; Kou, Shan Shan; Lin, Jiao; Abbey, Brian

2016-01-01

Colour filters based on nano-apertures in thin metallic films have been widely studied due to their extraordinary optical transmission and small size. These properties make them prime candidates for use in high-resolution colour displays and high accuracy bio-sensors. The inclusion of polarization sensitive plasmonic features in such devices allow additional control over the electromagnetic field distribution, critical for investigations of polarization induced phenomena. Here we demonstrate that cross-shaped nano-apertures can be used for polarization controlled color tuning in the visible range and apply fundamental theoretical models to interpret key features of the transmitted spectrum. Full color transmission was achieved by fine-tuning the periodicity of the apertures, whilst keeping the geometry of individual apertures constant. We demonstrate this effect for both transverse electric and magnetic fields. Furthermore we have been able to demonstrate the same polarization sensitivity even for nano-size, sub-wavelength sets of arrays, which is paramount for ultra-high resolution compact colour displays. PMID:27312072

Colour formation in fermented sausages by meat-associated staphylococci with different nitrite- and nitrate-reductase activities.

PubMed

Gøtterup, Jacob; Olsen, Karsten; Knøchel, Susanne; Tjener, Karsten; Stahnke, Louise H; Møller, Jens K S

2008-04-01

Three Staphylococcus strains, S. carnosus, S. simulans and S. saprophyticus, selected due to their varying nitrite and/or nitrate-reductase activities, were used to initiate colour formation during sausage fermentation. During fermentation of sausages with either nitrite or nitrate added, colour was followed by L(∗)a(∗)b measurements and the content of nitrosylmyoglobin (MbFe(II)NO) quantified by electron spin resonance (ESR). MbFe(II)NO was rapidly formed in sausages with added nitrite independent of the presence of nitrite reducing bacteria, whereas the rate of MbFe(II)NO formation in sausages with added nitrate depended on the specific Staphylococcus strain. Strains with high nitrate-reductase activity showed a significantly faster rate of pigment formation, but other factors were of influence as well. Product stability for the sliced, packaged sausage was evaluated as surface colour and oxidation by autofluorescence and hexanal content, respectively. No significant direct effect of the Staphylococcus addition was observed, however, there was a clear correspondence between high initial amount of MbFe(II)NO in the different sausages and the colour stability during storage. Autofluorescence data correlated well with hexanal content, and may be used as predictive tools. Overall, nitrite- and nitrate-reductase activities of Staphylococcus strains in nitrite-cured sausages were of limited importance regarding colour development, while in nitrate-cured sausages strains with higher nitrate reductase activity were crucial for ensuring optimal colour formation during initial fermentation stages.

Simultaneous removal of colour, phosphorus and disinfection from treated wastewater using an agent synthesized from amorphous silica and hydrated lime.

PubMed

Yamashita, Takahiro; Aketo, Tsuyoshi; Minowa, Nobutaka; Sugimoto, Kiyomi; Yokoyama, Hiroshi; Ogino, Akifumi; Tanaka, Yasuo

2013-01-01

An agent synthesized from amorphous silica and hydrated lime (CSH-lime) was investigated for its ability to simultaneously remove the colour, phosphorus and disinfection from the effluents from wastewater treatment plants on swine farms. CSH-lime removed the colour and phosphate from the effluents, with the colour-removal effects especially high at pH 12, and phosphorous removal was more effective in strongly alkaline conditions (pH > 10). Colour decreased from 432 +/-111 (mean +/- SD) to 107 +/- 41 colour units and PO4(3-)P was reduced from 45 +/- 39 mg/L to undetectable levels at the CSH-lime dose of 2.0% w/v. Moreover, CSH-lime reduced the total organic carbon from 99.0 to 37.9 mg/L at the dose of 2.0% w/v and was effective at inactivating total heterotrophic and coliform bacteria. However, CSH-lime did not remove nitrogen compounds such as nitrite, nitrate and ammonium. Colour was also removed from dye solutions by CSH-lime, at the same dose.

Sexual dichromatism in frogs: natural selection, sexual selection and unexpected diversity.

PubMed

Bell, Rayna C; Zamudio, Kelly R

2012-12-07

Sexual dichromatism, a form of sexual dimorphism in which males and females differ in colour, is widespread in animals but has been predominantly studied in birds, fishes and butterflies. Moreover, although there are several proposed evolutionary mechanisms for sexual dichromatism in vertebrates, few studies have examined this phenomenon outside the context of sexual selection. Here, we describe unexpectedly high diversity of sexual dichromatism in frogs and create a comparative framework to guide future analyses of the evolution of these sexual colour differences. We review what is known about evolution of colour dimorphism in frogs, highlight alternative mechanisms that may contribute to the evolution of sexual colour differences, and compare them to mechanisms active in other major groups of vertebrates. In frogs, sexual dichromatism can be dynamic (temporary colour change in males) or ontogenetic (permanent colour change in males or females). The degree and the duration of sexual colour differences vary greatly across lineages, and we do not detect phylogenetic signal in the distribution of this trait, therefore frogs provide an opportunity to investigate the roles of natural and sexual selection across multiple independent derivations of sexual dichromatism.

Iris pigmentation as a quantitative trait: variation in populations of European, East Asian and South Asian ancestry and association with candidate gene polymorphisms.

PubMed

Edwards, Melissa; Cha, David; Krithika, S; Johnson, Monique; Cook, Gillian; Parra, Esteban J

2016-03-01

In this study, we present a new quantitative method to measure iris colour based on high-resolution photographs. We applied this method to analyse iris colour variation in a sample of individuals of East Asian, European and South Asian ancestry. We show that measuring iris colour using the coordinates of the CIELAB colour space uncovers a significant amount of variation that is not captured using conventional categorical classifications, such as 'brown', 'blue' or 'green'. We tested the association of a selected panel of polymorphisms with iris colour in each population group. Six markers showed significant associations with iris colour in the European sample, three in the South Asian sample and two in the East Asian sample. We also observed that the marker HERC2 rs12913832, which is the main determinant of 'blue' versus 'brown' iris colour in European populations, is also significantly associated with central heterochromia in the European sample. © 2015 The Authors. Pigment Cell & Melanoma Research Published by John Wiley & Sons Ltd.

Spatio-temporal colour correction of strongly degraded movies

NASA Astrophysics Data System (ADS)

Islam, A. B. M. Tariqul; Farup, Ivar

2011-01-01

The archives of motion pictures represent an important part of precious cultural heritage. Unfortunately, these cinematography collections are vulnerable to different distortions such as colour fading which is beyond the capability of photochemical restoration process. Spatial colour algorithms-Retinex and ACE provide helpful tool in restoring strongly degraded colour films but, there are some challenges associated with these algorithms. We present an automatic colour correction technique for digital colour restoration of strongly degraded movie material. The method is based upon the existing STRESS algorithm. In order to cope with the problem of highly correlated colour channels, we implemented a preprocessing step in which saturation enhancement is performed in a PCA space. Spatial colour algorithms tend to emphasize all details in the images, including dust and scratches. Surprisingly, we found that the presence of these defects does not affect the behaviour of the colour correction algorithm. Although the STRESS algorithm is already in itself more efficient than traditional spatial colour algorithms, it is still computationally expensive. To speed it up further, we went beyond the spatial domain of the frames and extended the algorithm to the temporal domain. This way, we were able to achieve an 80 percent reduction of the computational time compared to processing every single frame individually. We performed two user experiments and found that the visual quality of the resulting frames was significantly better than with existing methods. Thus, our method outperforms the existing ones in terms of both visual quality and computational efficiency.

The Colour and Stereo Surface Imaging System (CaSSIS) for the ExoMars Trace Gas Orbiter

USGS Publications Warehouse

Thomas, N.; Cremonese, G.; Ziethe, R.; Gerber, M.; Brändli, M.; Bruno, G.; Erismann, M.; Gambicorti, L.; Gerber, T.; Ghose, K.; Gruber, M.; Gubler, P.; Mischler, H.; Jost, J.; Piazza, D.; Pommerol, A.; Rieder, M.; Roloff, V.; Servonet, A.; Trottmann, W.; Uthaicharoenpong, T.; Zimmermann, C.; Vernani, D.; Johnson, M.; Pelò, E.; Weigel, T.; Viertl, J.; De Roux, N.; Lochmatter, P.; Sutter, G.; Casciello, A.; Hausner, T.; Ficai Veltroni, I.; Da Deppo, V.; Orleanski, P.; Nowosielski, W.; Zawistowski, T.; Szalai, S.; Sodor, B.; Tulyakov, S.; Troznai, G.; Banaskiewicz, M.; Bridges, J.C.; Byrne, S.; Debei, S.; El-Maarry, M. R.; Hauber, E.; Hansen, C.J.; Ivanov, A.; Keszthelyil, L.; Kirk, Randolph L.; Kuzmin, R.; Mangold, N.; Marinangeli, L.; Markiewicz, W. J.; Massironi, M.; McEwen, A.S.; Okubo, Chris H.; Tornabene, L.L.; Wajer, P.; Wray, J.J.

2017-01-01

The Colour and Stereo Surface Imaging System (CaSSIS) is the main imaging system onboard the European Space Agency’s ExoMars Trace Gas Orbiter (TGO) which was launched on 14 March 2016. CaSSIS is intended to acquire moderately high resolution (4.6 m/pixel) targeted images of Mars at a rate of 10–20 images per day from a roughly circular orbit 400 km above the surface. Each image can be acquired in up to four colours and stereo capability is foreseen by the use of a novel rotation mechanism. A typical product from one image acquisition will be a 9.5 km×∼45 km">9.5 km×∼45 km9.5 km×∼45 km swath in full colour and stereo in one over-flight of the target thereby reducing atmospheric influences inherent in stereo and colour products from previous high resolution imagers. This paper describes the instrument including several novel technical solutions required to achieve the scientific requirements.

"Light-box" accelerated growth of poinsettias: LED-only illumination

NASA Astrophysics Data System (ADS)

Weerasuriya, Charitha; Detez, Stewart; Hock Ng, Soon; Hughes, Andrew; Callaway, Michael; Harrison, Iain; Katkus, Tomas; Juodkazis, Saulius

2018-01-01

For the current commercialized agricultural industry which requires a reduced product lead time to customer and supply all year round, an artificial light emitting diodes (LEDs)-based illumination has high potential due to high efficiency of electrical-to-light conversion. The main advantage of the deployed Red Green Blue Amber LED lighting system is colour mixing capability, which means ability to generate all the colours in the spectrum by using three or four primary colours LEDs. The accelerated plant growth was carried out in a "light-box" which was made to generate an artificial day/night cycle by moving the colour mixing ratio along the colour temperature curve of the chromaticity diagram. The control group of plants form the same initial batch was grown on the same shelf in a greenhouse at the same conditions with addition of artificial illumination by incandescent lamps for few hours. Costs and efficiency projections of LED lamps for horticultural applications is discussed together with required capital investment. The total cost of the "light-box" including LED lamps and electronics was 850 AUD.

Instant coffee as a source of antioxidant-rich and sugar-free coloured compounds for use in bakery: Application in biscuits.

PubMed

Passos, Cláudia P; Kukurová, Kristína; Basil, Eva; Fernandes, Pedro A R; Neto, Andreia; Nunes, Fernando M; Murkovic, Michael; Ciesarová, Zuzana; Coimbra, Manuel A

2017-09-15

Ammonia caramels are the most common antioxidant colour agent used in bakery formulations, although their high sugars content. An alternative could be coffee melanoidins, which are brown coloured compounds with antioxidant properties, readily available from instant coffee. However, high caffeine content is limiting its direct application. To evaluate the possibility of obtaining coloured melanoidin-rich, sugars- and caffeine-poor fractions from instant coffee, in this work, simple procedures based on their ethanol insolubility (fraction EtPp) or retention by ultrafiltration (fraction HWSn) were exploited. Melanoidins incorporation into biscuits formulation (amounts of 1, 5 and 10% w/w related to flour content) resulted in acceptable coloured products with higher antioxidant activity. The biscuits supplemented with 1% EtPp or HWSn had a low caffeine content. The caffeine of one espresso coffee was equivalent to 130 biscuits containing EtPp and 31 biscuits containing HWSn. Besides, both fractions did not promote extra formation of acrylamide or 5-hydroxymethylfurfural during baking. Copyright © 2017 Elsevier Ltd. All rights reserved.

Why fruits go to the dark side

NASA Astrophysics Data System (ADS)

Schaefer, H. Martin

2011-11-01

The colours of fleshy fruits are usually attributed to attract seed dispersers to the plant. A cursory look at the gaudy colours of fleshy fruits on offer in a local fruit stall gives the impression that plants use primarily bright colours to attract fruit consumer. This impression is misleading; many small fruits 'go to the dark side' and become dark purple or black when ripe. Intermingled in foliage, these colours, which are produced by anthocyanins, can be fairly inconspicuous and are thus not easily reconciled with a signalling function to attract seed dispersers. In this review I therefore discuss complementary hypotheses on the function and evolution of fruit colouration. First, I focus on the evidence that fruit colours indeed function as signals to attract seed dispersers. I then show that anthocyanins, the most prevalent fruit pigments, are important dietary antioxidants that can be selected by blackcaps ( Sylvia atricapilla) which are important avian seed dispersers of many European plants. Moreover, the consumption of anthocyanins increases the likelihood that blackcaps mount an immune response during immune challenges. As a next step, I review evidence that anthocyanins accumulate in fruit skin in response to abiotic factors, in particular high illumination coupled with low temperature favour the increase of anthocyanins. Finally, I show that anthocyanins can also be selected for by fruit antagonists, consumers that do not disperse seeds. In particular, high contents of anthocyanins strongly reduce fungal growth in fruit tissue. Taken together, there are various selective pressures which likely influence fruit colour evolution. Currently, the relative importance of each of these selective agents is unknown. There is consequently a need to develop a more encompassing framework on fruit colour evolution.

Colour and label evaluation of commercial pasteurised red juices and related drinks.

PubMed

Fallico, B; Arena, E; Chiappara, E; Ballistreri, G

2010-01-01

Despite growing demand by consumers for healthy beverages, artificial colours are still widely used. Levels of anthocyanins and artificial colours were determined by HPLC with UV-Vis detection in red orange juices and other red beverages (nectar, juice-based, health, carbonated and sports drinks). The contribution of pigments to the visible colour of the beverage was calculated. Red orange juice samples contained about 34 mg l(-1) of anthocyanins, which were responsible for about 92% of the visible colour. Red juice-based drinks, containing from 0% to 30% of red orange, berry, grape or pomegranate juices, had low levels of anthocyanins (about 7 mg l(-1)) and high levels of E129 (about 32 mg l(-1)), which were responsible for about 90.7% of the colour of these beverages. Red health drinks, enriched with vitamins and polyphenols, contained from 3% to 50% of red fruit juices. Also in this case the E129 levels were higher (about 22 mg l(-1)) than anthocyanins (about 9 mg l(-1)), and were responsible for the colour of the beverages (76.1%). High levels of artificial colours were found in red orange carbonated drinks, but in comparable amounts with those found in the other beverage samples, while anthocyanins were only present in trace amounts. Although all of the beverages claimed to contain red fruits on the labels, no correlation was found between the level of anthocyanins and the declared percentage of red fruits. These labels generally conformed with the requirements of the law, but food product labels can often be misleading to consumers about the real characteristics of the product.

Colour-barcoded magnetic microparticles for multiplexed bioassays.

PubMed

Lee, Howon; Kim, Junhoi; Kim, Hyoki; Kim, Jiyun; Kwon, Sunghoon

2010-09-01

Encoded particles have a demonstrated value for multiplexed high-throughput bioassays such as drug discovery and clinical diagnostics. In diverse samples, the ability to use a large number of distinct identification codes on assay particles is important to increase throughput. Proper handling schemes are also needed to readout these codes on free-floating probe microparticles. Here we create vivid, free-floating structural coloured particles with multi-axis rotational control using a colour-tunable magnetic material and a new printing method. Our colour-barcoded magnetic microparticles offer a coding capacity easily into the billions with distinct magnetic handling capabilities including active positioning for code readouts and active stirring for improved reaction kinetics in microscale environments. A DNA hybridization assay is done using the colour-barcoded magnetic microparticles to demonstrate multiplexing capabilities.

Polishing of treated palm oil mill effluent (POME) from ponding system by electrocoagulation process.

PubMed

Bashir, Mohammed J K; Mau Han, Tham; Jun Wei, Lim; Choon Aun, Ng; Abu Amr, Salem S

2016-01-01

As the ponding system used to treat palm oil mill effluent (POME) frequently fails to satisfy the discharge standard in Malaysia, the present study aimed to resolve this problem using an optimized electrocoagulation process. Thus, a central composite design (CCD) module in response surface methodology was employed to optimize the interactions of process variables, namely current density, contact time and initial pH targeted on maximum removal of chemical oxygen demand (COD), colour and turbidity with satisfactory pH of discharge POME. The batch study was initially designed by CCD and statistical models of responses were subsequently derived to indicate the significant terms of interactive process variables. All models were verified by analysis of variance showing model significances with Prob > F < 0.01. The optimum performance was obtained at the current density of 56 mA/cm(2), contact time of 65 min and initial pH of 4.5, rendering complete removal of colour and turbidity with COD removal of 75.4%. The pH of post-treated POME of 7.6 was achieved, which is suitable for direct discharge. These predicted outputs were subsequently confirmed by insignificant standard deviation readings between predicted and actual values. This optimum condition also permitted the simultaneous removal of NH3-N, and various metal ions, signifying the superiority of the electrocoagulation process optimized by CCD.

Pupal colour plasticity in a tropical butterfly, Mycalesis mineus (Nymphalidae: Satyrinae).

PubMed

Mayekar, Harshad Vijay; Kodandaramaiah, Ullasa

2017-01-01

Lepidopteran insects have provided excellent study systems for understanding adaptive phenotypic plasticity. Although there are a few well-studied examples of adult plasticity among tropical butterflies, our understanding of plasticity of larval and pupal stages is largely restricted to temperate butterflies. The environmental parameters inducing phenotypic plasticity and the selective pressures acting on phenotypes are likely to differ across tropical and temperate climate regimes. We tested the influence of relative humidity (RH), a prominent yet under-appreciated tropical climatic component, along with pupation substrate, larval development time, pupal sex and weight in determining pupal colour in the tropical satyrine butterfly Mycalesis mineus. Pupae of this butterfly are either brown or green or very rarely intermediate. Larvae were reared at high (85%) and low (60%) RH at a constant temperature. Proportions of green and brown pupae were expected to vary across low and high RH and pupation substrates in order to enhance crypsis. Brown pupae were more common at low RH than at high RH, as predicted, and developed faster than green pupae. Pupal colour was correlated with pupation substrate. Choice of pupation substrate differed across RH treatments. It is unclear whether pupal colour influences substrate selection or whether substrate influences pupal colour. Our study underscores the need for further work to understand the basis of pupal plasticity in tropical butterflies.

Lack of tumour pigmentation in conjunctival melanoma is associated with light iris colour and worse prognosis.

PubMed

Brouwer, Niels J; Marinkovic, Marina; Luyten, Gregorius P M; Shields, Carol L; Jager, Martine J

2018-05-18

To investigate whether differences in iris colour, skin colour and tumour pigmentation are related to clinical outcome in conjunctival melanoma. Data of 70 patients with conjunctival melanoma from the Leiden University Medical Center (Leiden, The Netherlands) and 374 patients from the Wills Eye Hospital (Philadephia, USA) were reviewed. The relation between iris colour, skin colour and tumour pigmentation versus clinical parameters and outcome was investigated using univariate and multivariate regression analyses. A light iris colour (blue, grey, green) was present in 261 (59%) patients and a dark colour (hazel, brown) in 183 (41%). A low tumour pigmentation was detected in 130 (40%) and a high pigmentation in 197 (60%) patients. Low tumour pigmentation was associated with light iris colour (p=0.021) but not related to skin colour (p=0.92). In univariate analysis, neither iris nor skin colour was related to clinical outcome, while a low tumour pigmentation was related to metastasis formation (HR 2.37, p=0.004) and death (HR 2.42, p=0.020). In multivariate analysis, low tumour pigmentation was related to the development of recurrences (HR 1.63, p=0.043), metastasis formation (HR 2.48, p=0.004) and death (HR 2.60, p=0.014). Lightly pigmented tumours occurred especially in individuals with lightly coloured irises. While iris colour or skin colour was not significantly related to clinical outcome, a low tumour pigmentation was related to a worse outcome in patients with conjunctival melanoma. The amount and type of melanin in conjunctival melanocytes may be involved in the pathogenesis and behaviour of selected conjunctival melanoma. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The astronomer of the duchess -- Life and work of Franz Xaver von Zach 1754-1832. (German Title: Der Astronom der Herzogin -- Leben und Werk von Franz Xaver von Zach 1754-1832)

NASA Astrophysics Data System (ADS)

Brosche, Peter

The astronomer, geodesist, geographer and historian of science Franz Xaver von Zach (1754-1832) lived and worked in several European countries. Duke Ernst II of Saxe-Gotha-Altenburg appointed him as the founding scientist of his Seeberg Observatory. This was the place of his strongest activity. Why should we have an interest in him today? There is a rational and an emotional answer. First, he has rendered organisational services to his sciences which are equivalent to a great scientific achievement. Second, Zach was a very colourful character, travelled across many states in a time of radical changes and had connections with many colleagues and public figures. Images from his life therefore provide outlooks, insights and relations.

Seamless Image Mosaicking via Synchronization

NASA Astrophysics Data System (ADS)

Santellani, E.; Maset, E.; Fusiello, A.

2018-05-01

This paper proposes an innovative method to create high-quality seamless planar mosaics. The developed pipeline ensures good robustness against many common mosaicking problems (e.g., misalignments, colour distortion, moving objects, parallax) and differs from other works in the literature because a global approach, known as synchronization, is used for image registration and colour correction. To better conceal the mosaic seamlines, images are cut along specific paths, computed using a Voronoi decomposition of the mosaic area and a shortest path algorithm. Results obtained on challenging real datasets show that the colour correction mitigates significantly the colour variations between the original images and the seams on the final mosaic are not evident.

Laser induced single spot oxidation of titanium

NASA Astrophysics Data System (ADS)

Jwad, Tahseen; Deng, Sunan; Butt, Haider; Dimov, S.

2016-11-01

Titanium oxides have a wide range of applications in industry, and they can be formed on pure titanium using different methods. Laser-induced oxidation is one of the most reliable methods due to its controllability and selectivity. Colour marking is one of the main applications of the oxidation process. However, the colourizing process based on laser scanning strategies is limited by the relative large processing area in comparison to the beam size. Single spot oxidation of titanium substrates is proposed in this research in order to increase the resolution of the processed area and also to address the requirements of potential new applications. The method is applied to produce oxide films with different thicknesses and hence colours on titanium substrates. High resolution colour image is imprinted on a sheet of pure titanium by converting its pixels' colours into laser parameter settings. Optical and morphological periodic surface structures are also produced by an array of oxide spots and then analysed. Two colours have been coded into one field and the dependencies of the reflected colours on incident and azimuthal angles of the light are discussed. The findings are of interest to a range of application areas, as they can be used to imprint optical devices such as diffusers and Fresnel lenses on metallic surfaces as well as for colour marking.

Colour compatibility between teeth and dental shade guides in Quinquagenarians and Septuagenarians.

PubMed

Cocking, C; Cevirgen, E; Helling, S; Oswald, M; Corcodel, N; Rammelsberg, P; Reinelt, G; Hassel, A J

2009-11-01

The aim of this investigation was to determine colour compatibility between dental shade guides, namely, VITA Classical (VC) and VITA 3D-Master (3D), and human teeth in quinquagenarians and septuagenarians. Tooth colour, described in terms of L*a*b* values of the middle third of facial tooth surface of 1391 teeth, was measured using VITA Easyshade in 195 subjects (48% female). These were compared with the colours (L*a*b* values) of the shade tabs of VC and 3D. The mean coverage error and the percentage of tooth colours being within a given colour difference (DeltaE(ab)) from the tabs of VC and 3D were calculated. For comparison, hypothetical, optimized, population-specific shade guides were additionally calculated based on discrete optimization techniques for optimizing coverage. Mean coverage error was DeltaE(ab) = 3.51 for VC and DeltaE(ab) = 2.96 for 3D. Coverage of tooth colours by the tabs of VC and 3D within DeltaE(ab) = 2 was 23% and 24%, respectively, (DeltaE(ab)

Keeping It in Three Dimensions: Measuring the Development of Mental Rotation in Children with the Rotated Colour Cube Test (RCCT).

PubMed

Lütke, Nikolay; Lange-Küttner, Christiane

2015-08-03

This study introduces the new Rotated Colour Cube Test (RCCT) as a measure of object identification and mental rotation using single 3D colour cube images in a matching-to-sample procedure. One hundred 7- to 11-year-old children were tested with aligned or rotated cube models, distracters and targets. While different orientations of distracters made the RCCT more difficult, different colours of distracters had the opposite effect and made the RCCT easier because colour facilitated clearer discrimination between target and distracters. Ten-year-olds performed significantly better than 7- to 8-year-olds. The RCCT significantly correlated with children's performance on the Raven's Coloured Progressive Matrices Test (RCPM) presumably due to the shared multiple-choice format, but the RCCT was easier, as it did not require sequencing. Children from families with a high socio-economic status performed best on both tests, with boys outperforming girls on the more difficult RCCT test sections.

Linear increases in BOLD response associated with increasing proportion of incongruent trials across time in a colour Stroop task.

PubMed

Mitchell, Rachel L C

2010-05-01

Selective attention is popularly assessed with colour Stroop tasks in which participants name the ink colour of colour words, whilst resisting interference from the natural tendency to read the words. Prior studies hinted that the key brain regions (dorsolateral prefrontal (dlPFC) and anterior cingulate cortex (ACC)) may vary their degree of involvement, dependent on attentional demand. This study aimed to determine whether a parametrically varied increase in attentional demand resulted in linearly increased activity in these regions, and/or whether additional regions would be recruited during high attentional demand. Twenty-eight healthy young adults underwent fMRI whilst naming the font colour of colour words. Linear increases in BOLD response were assessed with increasing percentage incongruent trials per block (0, 20, 40, 60, 80, and 100%). Whilst ACC activation increased linearly according to incongruity level, dlPFC activity appeared constant. Together with behavioural evidence of reduced Stroop interference, these data support a load-dependent conflict-related response in ACC, but not dlPFC.

Type of packaging affects the colour stability of vitamin E enriched beef.

PubMed

Nassu, Renata T; Uttaro, Bethany; Aalhus, Jennifer L; Zawadski, Sophie; Juárez, Manuel; Dugan, Michael E R

2012-12-01

Colour stability is a very important parameter for meat retail display, as appearance of the product is the deciding factor for consumers at time of purchase. This study investigated the possibility of extending appearance shelf-life through the combined use of packaging method (overwrapping - OVER, modified atmosphere - MAP, vacuum skin packaging - VSP and a combination of modified atmosphere and vacuum skin packaging - MAPVSP) and antioxidants (vitamin E enriched beef). Retail attributes (appearance, lean colour, % surface discolouration), as well as colour space analysis of images for red, green and blue parameters were measured over 18days. MAPVSP provided the most desirable retail appearance during the first 4days of retail display, while VSP-HB had the best colour stability. Overall, packaging type was more influential than α-tocopherol levels on meat colour stability, although α-tocopherol levels (>4μgg(-1) meat) had a protective effect when using high oxygen packaging methods. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Spectral response data for development of cool coloured tile coverings

NASA Astrophysics Data System (ADS)

Libbra, Antonio; Tarozzi, Luca; Muscio, Alberto; Corticelli, Mauro A.

2011-03-01

Most ancient or traditional buildings in Italy show steep-slope roofs covered by red clay tiles. As the rooms immediately below the roof are often inhabited in historical or densely urbanized centres, the combination of low solar reflectance of tile coverings and low thermal inertia of either wooden roof structures or sub-tile insulation panels makes summer overheating a major problem. The problem can be mitigated by using tiles coated with cool colours, that is colours with the same spectral response of clay tiles in the visible, but highly reflecting in the near infrared range, which includes more than half of solar radiation. Cool colours can yield the same visible aspect of common building surfaces, but higher solar reflectance. Studies aimed at developing cool colour tile coverings for traditional Italian buildings have been started. A few coating solutions with the typical red terracotta colour have been produced and tested in the laboratory, using easily available materials. The spectral response and the solar reflectance have been measured and compared with that of standard tiles.

Comparative study of qualitative and quantitative methods to determine toxicity level of Aspergillus flavus isolates in maize.

PubMed

Shekhar, Meena; Singh, Nirupma; Dutta, Ram; Kumar, Shrvan; Mahajan, Vinay

2017-01-01

An attempt was made to compare between easy and inexpensive qualitative method (ammonia vapour test) and analytical methods (thin layer chromatography and enzyme-linked immunosorbent assay) for identification of aflatoxigenic isolates of Aspergillus flavus in maize. In this comparative study the toxicity level of A. flavus isolates exhibited 100% agreement among ammonia vapour test, ELISA and TLC for highly toxigenic (>2000 ppb) and toxigenic (501-2000 ppb) isolates while 88.5% agreement observed for least toxic (<20 ppb) isolates. In ammonia vapour test 51% of A. flavus isolates showed creamish or no colour change corresponding to least toxic/atoxic (<20ppb) category estimated by ELISA. Similarly 22% highly toxic isolates exhibited plum red colour, 12% moderately toxic indicated pink colour and 10% toxic isolates showed red colour. However, 11.5% isolates were found to be false positive in cream colour category (least toxic) and 28.5% false negatives in pink colour (moderately toxic) category. The isolates from different agroclimatic zones of maize in India showed high variability for aflatoxin B1 (AFB1) production potential ranging from 0.214-8116.61 ppb. Toxigenic potential of Aspergillus flavus isolates in culture was further validated by inoculating maize grain sample with four different isolates with varied toxin producing ability. With good agreement percentage between cultural and analytical methods the study concludes the ammonia vapour test to be easy, inexpensive, reliable and time saving method that can be used for segregating or pre-screening of contaminated samples from bulk food/feed stock.

Estimated daily intake and safety of FD&C food-colour additives in the US population.

PubMed

Bastaki, Maria; Farrell, Thomas; Bhusari, Sachin; Bi, Xiaoyu; Scrafford, Carolyn

2017-06-01

A refined exposure assessment was undertaken to calculate the estimated daily intake (EDI) of the seven FD&C straight-colour additives and five FD&C colour lakes ('synthetic' food colours) approved in the United States. The EDIs were calculated for the US population as a whole and specific age groups, including children aged 2-5 and 6-12 years, adolescents aged 13-18 years, and adults aged 19 or more y. Actual use data were collected from an industry survey of companies that are users of these colour additives in a variety of products, with additional input from food colour manufacturers. Food-consumption data were obtained from the National Health and Nutrition Examination Survey (NHANES). The assessment was further refined by adjusting the intake to more realistic scenarios based on the fraction of products containing colour within specific food categories using data provided by the Mintel International Group Ltd. The results of the analysis indicate that (1) the use levels reported by the industry are consistent with the concentrations measured analytically by the US Food and Drug Administration; and (2) exposure to food-colour additives in the United States by average and high-intake consumers is well below the acceptable daily intake (ADI) of each colour additive as published by the Joint WHO/FAO Committee on Food Additives (JECFA) and allows wide margins of safety. It is concluded that food colour use as currently practised in the United States is safe and does not result in excessive exposure to the population, even at conservative ranges of food consumption and levels of use.

The Influence of Colour on Memory Performance: A Review

PubMed Central

Dzulkifli, Mariam Adawiah; Mustafar, Muhammad Faiz

2013-01-01

Human cognition involves many mental processes that are highly interrelated, such as perception, attention, memory, and thinking. An important and core cognitive process is memory, which is commonly associated with the storing and remembering of environmental information. An interesting issue in memory research is on ways to enhance memory performance, and thus, remembering of information. Can colour result in improved memory abilities? The present paper highlights the relationship between colours, attention, and memory performance. The significance of colour in different settings is presented first, followed by a description on the nature of human memory. The role of attention and emotional arousal on memory performance is discussed next. The review of several studies on colours and memory are meant to explain some empirical works done in the area and related issues that arise from such studies. PMID:23983571

The influence of colour on memory performance: a review.

PubMed

Dzulkifli, Mariam Adawiah; Mustafar, Muhammad Faiz

2013-03-01

Human cognition involves many mental processes that are highly interrelated, such as perception, attention, memory, and thinking. An important and core cognitive process is memory, which is commonly associated with the storing and remembering of environmental information. An interesting issue in memory research is on ways to enhance memory performance, and thus, remembering of information. Can colour result in improved memory abilities? The present paper highlights the relationship between colours, attention, and memory performance. The significance of colour in different settings is presented first, followed by a description on the nature of human memory. The role of attention and emotional arousal on memory performance is discussed next. The review of several studies on colours and memory are meant to explain some empirical works done in the area and related issues that arise from such studies.

First Results from the AKARI FU-HYU Mission Program

NASA Astrophysics Data System (ADS)

Pearson, C.; Serjeant, S.; Takagi, T.; Jeong, W.-S.; Negrello, M.; Matsuhara, H.; Wada, T.; Oyabu, S.; Lee, H. M.; Im, M.

2009-12-01

The AKARI FU-HYU mission program has carried out mid-infrared imaging of several well studied Spitzer fields. This imaging fills in the wavelength coverage lacking from the Spitzer surveys and gives an extremely high scientific return for minimal input for AKARI. We select fields already rich in multi-wavelength data from radio to X-ray wavelengths and present the results from our initial analysis in the GOODS-N field. We utilize the comprehansive multiwavelength coverage in the GOODS-N field to produce a multiwavelength catalogue from infrared to ultraviolet wavelengths including photometric redshifts. Using the FU-HYU catalogue we present colour-colour diagrams that map the passage of PAH features through our observation bands. These colour-colours diagrams are used as tools to extract anomalous colour populations, in particular a population of Silicate Break galaxies from the GOODS-N field.

Demosaicing images from colour cameras for digital image correlation

NASA Astrophysics Data System (ADS)

Forsey, A.; Gungor, S.

2016-11-01

Digital image correlation is not the intended use for consumer colour cameras, but with care they can be successfully employed in such a role. The main obstacle is the sparsely sampled colour data caused by the use of a colour filter array (CFA) to separate the colour channels. It is shown that the method used to convert consumer camera raw files into a monochrome image suitable for digital image correlation (DIC) can have a significant effect on the DIC output. A number of widely available software packages and two in-house methods are evaluated in terms of their performance when used with DIC. Using an in-plane rotating disc to produce a highly constrained displacement field, it was found that the bicubic spline based in-house demosaicing method outperformed the other methods in terms of accuracy and aliasing suppression.

Automaticity and localisation of concurrents predicts colour area activity in grapheme-colour synaesthesia.

PubMed

Gould van Praag, Cassandra D; Garfinkel, Sarah; Ward, Jamie; Bor, Daniel; Seth, Anil K

2016-07-29

In grapheme-colour synaesthesia (GCS), the presentation of letters or numbers induces an additional 'concurrent' experience of colour. Early functional MRI (fMRI) investigations of GCS reported activation in colour-selective area V4 during the concurrent experience. However, others have failed to replicate this key finding. We reasoned that individual differences in synaesthetic phenomenology might explain this inconsistency in the literature. To test this hypothesis, we examined fMRI BOLD responses in a group of grapheme-colour synaesthetes (n=20) and matched controls (n=20) while characterising the individual phenomenology of the synaesthetes along dimensions of 'automaticity' and 'localisation'. We used an independent functional localiser to identify colour-selective areas in both groups. Activations in these areas were then assessed during achromatic synaesthesia-inducing, and non-inducing conditions; we also explored whole brain activations, where we sought to replicate the existing literature regarding synaesthesia effects. Controls showed no significant activations in the contrast of inducing > non-inducing synaesthetic stimuli, in colour-selective ROIs or at the whole brain level. In the synaesthete group, we correlated activation within colour-selective ROIs with individual differences in phenomenology using the Coloured Letters and Numbers (CLaN) questionnaire which measures, amongst other attributes, the subjective automaticity/attention in synaesthetic concurrents, and their spatial localisation. Supporting our hypothesis, we found significant correlations between individual measures of synaesthetic phenomenology and BOLD responses in colour-selective areas, when contrasting inducing against non-inducing stimuli. Specifically, left-hemisphere colour area responses were stronger for synaesthetes scoring high on phenomenological localisation and automaticity/attention, while right-hemisphere colour area responses showed a relationship with localisation only. In exploratory whole brain analyses, the BOLD response within several other areas was also correlated with these phenomenological factors, including the intra-parietal sulcus, insula, precentral and supplementary motor areas. Our findings reveal a network of regions underlying synaesthetic phenomenology and they help reconcile the diversity of previous results regarding colour-selective BOLD responses during synaesthesia, by establishing a bridge between neural responses and individual synaesthetic phenomenology. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Doppler ultrasonography of the anterior knee tendons in elite badminton players: colour fraction before and after match.

PubMed

Koenig, M J; Torp-Pedersen, S; Boesen, M I; Holm, C C; Bliddal, H

2010-02-01

Anterior knee tendon problems are seldom reported in badminton players although the game is obviously stressful to the lower extremities. Painful anterior knee tendons are common among elite badminton players. The anterior knee tendons exhibit colour Doppler activity. This activity increases after a match. Painful tendons have more Doppler activity than tendons without pain. Cohort study. 72 elite badminton players were interviewed about training, pain and injuries. The participants were scanned with high-end ultrasound equipment. Colour Doppler was used to examine the tendons of 64 players before a match and 46 players after a match. Intratendinous colour Doppler flow was measured as colour fraction (CF). The tendon complex was divided into three loci: the quadriceps tendon, the proximal patellar tendon and the insertion on the tibial tuberosity. Interview: Of the 72 players, 62 players had problems with 86 tendons in the lower extremity. Of these 86 tendons, 48 were the anterior knee tendons. Ultrasound: At baseline, the majority of players (87%) had colour Doppler flow in at least one scanning position. After a match, the percentage of the knee complexes involved did not change. CF increased significantly in the dominant leg at the tibial tuberosity; single players had a significantly higher CF after a match at the tibial tuberosity and in the patellar tendon both before and after a match. Painful tendons had the highest colour Doppler activity. Most elite badminton players had pain in the anterior knee tendons and intratendinous Doppler activity both before and after match. High levels of Doppler activity were associated with self-reported ongoing pain.

Does egg colouration reflect male condition in birds?

NASA Astrophysics Data System (ADS)

Martínez-Padilla, Jesús; Dixon, Heather; Vergara, Pablo; Pérez-Rodríguez, Lorenzo; Fargallo, Juan A.

2010-05-01

How colouration provides information about individuals in birds has been a central issue in recent decades. Although much information has been derived, little is known about the adaptive significance of egg colouration in birds. A recent idea suggests that biliverdin- and porphyrin-pigmented eggs may act as a post-mating sexual signal for males to assess female quality. In birds, it is common for males to influence prelaying female condition by courtship feeding. Using Eurasian kestrels, a species that lays protoporphyrin-pigmented eggs, we descriptively assessed the influence of male feeding on egg pigmentation by considering female phenotype, condition, breeding parameters and male body condition. We found that older females and females with greyer tails (an index of individual quality) produce highly pigmented eggs. However, male body condition was the only variable that explained egg colouration when considered together with the female-related variables. Therefore, females that mated with males in better condition laid highly pigmented eggs. With the same species, we also explored the cost of producing protoporphyrin-pigmented eggs using a food-supply experiment before the laying period. Food supplementation did not increase egg pigmentation, but hatching success and egg mass were positively related to egg colouration only in food supplied pairs. We suggest that egg colouration might be costly to produce and probably suggests egg quality. However, this cost cannot be explained by female quality, but by male condition instead. In general, our results do not support the theory that egg colouration is a post-mating sexual signal in species where males determine female condition at the time of laying.

Effect of font size, italics, and colour count on web usability.

PubMed

Bhatia, Sanjiv K; Samal, Ashok; Rajan, Nithin; Kiviniemi, Marc T

2011-04-01

Web usability measures the ease of use of a website. This study attempts to find the effect of three factors - font size, italics, and colour count - on web usability. The study was performed using a set of tasks and developing a survey questionnaire. We performed the study using a set of human subjects, selected from the undergraduate students taking courses in psychology. The data computed from the tasks and survey questionnaire were statistically analysed to find if there was any effect of font size, italics, and colour count on the three web usability dimensions. We found that for the student population considered, there was no significant effect of font size on usability. However, the manipulation of italics and colour count did influence some aspects of usability. The subjects performed better for pages with no italics and high italics compared to moderate italics. The subjects rated the pages that contained only one colour higher than the web pages with four or six colours. This research will help web developers better understand the effect of font size, italics, and colour count on web usability in general, and for young adults, in particular.

Effect of font size, italics, and colour count on web usability

PubMed Central

Samal, Ashok; Rajan, Nithin; Kiviniemi, Marc T.

2013-01-01

Web usability measures the ease of use of a website. This study attempts to find the effect of three factors – font size, italics, and colour count – on web usability. The study was performed using a set of tasks and developing a survey questionnaire. We performed the study using a set of human subjects, selected from the undergraduate students taking courses in psychology. The data computed from the tasks and survey questionnaire were statistically analysed to find if there was any effect of font size, italics, and colour count on the three web usability dimensions. We found that for the student population considered, there was no significant effect of font size on usability. However, the manipulation of italics and colour count did influence some aspects of usability. The subjects performed better for pages with no italics and high italics compared to moderate italics. The subjects rated the pages that contained only one colour higher than the web pages with four or six colours. This research will help web developers better understand the effect of font size, italics, and colour count on web usability in general, and for young adults, in particular. PMID:24358055

Colour Stability of Various Types of Acrylic Teeth Exposed to Coffee, Tea and Cola

PubMed Central

S, Mousavi; S, Narimani; S, Hekmatfar; K, Jafari

2016-01-01

Statement of Problem: Acrylic teeth of dentures are prone to discoloration due to frequent exposure to different colouring solutions in the oral environment. Thus, in order to maintain their aesthetic appearance, they must possess high colour stability while exposed to colorant solutions. Objectives: To compare the colour stability of three different brands of acrylic teeth following immersion in coffee, tea and cola. Materials and Methods: This in vitro experimental study was conducted on 90 acrylic teeth in three groups (n = 30) of Ivoclar (Italy), PolyDent (Slovenia) and Apple (Iran). The teeth were immersed in coffee, cola and tea for one, three and six weeks (the teeth were not in contact with each other). Colour parameters were assessed before and after immersion using a spectrophotometer, and overall change in colour parameters was calculated. The overall colour change (ΔE) of the three groups at different time points was analyzed using one-way ANOVA. Pairwise comparisons were performed using Tukey’s test. Results: Coffee caused the greatest colour change in Apple acrylic teeth after six weeks (mean ΔE of 4.6 for coffee and 3.4 for tea and cola). Tea caused an almost equal colour change in the three groups. The greatest colour change in the Ivoclar teeth occurred in cola after six weeks (mean ΔE of 3.3, 3.4 and 2.8 for cola, tea and coffee, respectively). The greatest ΔE occurred at six weeks and was the highest in Apple, followed by PolyDent and then Ivoclar teeth in coffee (mean ΔE of 4.6, 3.4 and 3.3, respectively p < 0.001). Conclusions: Despite the significant colour change in the three groups, ΔE in Ivoclar group was within the clinically acceptable range of ≤ 3.3. A slight colour change was expected regarding the Apple and PolyDent acrylic teeth clinically. PMID:28959762

Colour Stability of Various Types of Acrylic Teeth Exposed to Coffee, Tea and Cola.

PubMed

S, Mousavi; S, Narimani; S, Hekmatfar; K, Jafari

2016-12-01

Acrylic teeth of dentures are prone to discoloration due to frequent exposure to different colouring solutions in the oral environment. Thus, in order to maintain their aesthetic appearance, they must possess high colour stability while exposed to colorant solutions. To compare the colour stability of three different brands of acrylic teeth following immersion in coffee, tea and cola. This in vitro experimental study was conducted on 90 acrylic teeth in three groups (n = 30) of Ivoclar (Italy), PolyDent (Slovenia) and Apple (Iran). The teeth were immersed in coffee, cola and tea for one, three and six weeks (the teeth were not in contact with each other). Colour parameters were assessed before and after immersion using a spectrophotometer, and overall change in colour parameters was calculated. The overall colour change (ΔE) of the three groups at different time points was analyzed using one-way ANOVA. Pairwise comparisons were performed using Tukey's test. Coffee caused the greatest colour change in Apple acrylic teeth after six weeks (mean ΔE of 4.6 for coffee and 3.4 for tea and cola). Tea caused an almost equal colour change in the three groups. The greatest colour change in the Ivoclar teeth occurred in cola after six weeks (mean ΔE of 3.3, 3.4 and 2.8 for cola, tea and coffee, respectively). The greatest ΔE occurred at six weeks and was the highest in Apple, followed by PolyDent and then Ivoclar teeth in coffee (mean ΔE of 4.6, 3.4 and 3.3, respectively p < 0.001). Despite the significant colour change in the three groups, ΔE in Ivoclar group was within the clinically acceptable range of ≤ 3.3. A slight colour change was expected regarding the Apple and PolyDent acrylic teeth clinically.

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.

Filling schemes of silver dots inkjet-printed on pixelated nanostructured surfaces

NASA Astrophysics Data System (ADS)

Alan, Sheida; Jiang, Hao; Shahbazbegian, Haleh; Patel, Jasbir N.; Kaminska, Bozena

2017-03-01

Recently, our group demonstrated an inkjet-based technique to enable high-throughput, versatile and full-colour printing of structural colours on generic pixelated nanostructures, termed as molded ink on nanostructured surfaces. The printed colours are controlled by the area of printed silver on the pixelated red, green and blue polymer nanostructure arrays. This paper investigates the behaviour of jetted silver ink droplets on nanostructured surfaces and the microscale dot patterns implemented during printing process, for achieving accurate and consistent colours in the printed images. The surface wettability and the schemes of filling silver dots inside the subpixels are crucial to the quality of printed images. Several related concepts and definitions are introduced, such as filling ratio, full dots per subpixel (DPSP), number of printable colours, colour leaking and dot merging. In our experiments, we first chemically modified the surface to control the wettability and dot size. From each type of modified surface, various filling schemes were experimented and the printed results were evaluated with comprehensive considerations on the number of printable colours and the negative effects of colour leaking and dot merging. Rational selection of the best filling scheme resulted in a 2-line filling scheme using 20 μm dot spacing and line spacing capable of printing 9261 different colours with 121 pixel per inch display resolution, on low-wettability surface. This study is of vital importance for scaling up the printing technique in industrial applications and provides meaningful insights for inkjet-printing on nanostructures.

Solvent-free optical recording of structural colours on pre-imprinted photocrosslinkable nanostructures

NASA Astrophysics Data System (ADS)

Jiang, Hao; Rezaei, Mohamad; Abdolahi, Mahssa; Kaminska, Bozena

2017-09-01

Optical digital information storage media, despite their ever-increasing storage capacity and data transfer rate, are vulnerable to the potential risk of turning inaccessible. For this reason, long-term eye-readable full-colour optical archival storage is in high demand for preserving valuable information from cultural, intellectual, and scholarly resources. However, the concurrent requirements in recording colours inexpensively and precisely, and preserving colours for the very long term (for at least 100 years), have not yet been met by existing storage techniques. Structural colours hold the promise to overcome such challenges. However, there is still the lack of an inexpensive, rapid, reliable, and solvent-free optical patterning technique for recording structural colours. In this paper, we introduce an enabling technique based on optical and thermal patterning of nanoimprinted SU-8 nanocone arrays. Using photocrosslinking and thermoplastic flow of SU-8, diffractive structural colours of nanocone arrays are recorded using ultra-violet (UV) exposure followed by the thermal development and reshaping of nanocones. Different thermal treatment procedures in reshaping nanocones are investigated and compared, and two-step progressive baking is found to allow the controllable reshaping of nanocones. The height of the nanocones and brightness of diffractive colours are modulated by varying the UV exposure dose to enable grey-scale patterning. An example of recorded full-colour image through half-tone patterning is also demonstrated. The presented technique requires only low-power continuous-wave UV light and is very promising to be adopted for professional and consumer archival storage applications.

Simultaneous three wavelength imaging with a scanning laser ophthalmoscope.

PubMed

Reinholz, F; Ashman, R A; Eikelboom, R H

1999-11-01

Various imaging properties of scanning laser ophthalmoscopes (SLO) such as contrast or depth discrimination, are superior to those of the traditional photographic fundus camera. However, most SLO are monochromatic whereas photographic systems produce colour images, which inherently contain information over a broad wavelength range. An SLO system has been modified to allow simultaneous three channel imaging. Laser light sources in the visible and infrared spectrum were concurrently launched into the system. Using different wavelength triads, digital fundus images were acquired at high frame rates. Favourable wavelengths combinations were established and high contrast, true (red, green, blue) or false (red, green, infrared) colour images of the retina were recorded. The monochromatic frames which form the colour image exhibit improved distinctness of different retinal structures such as the nerve fibre layer, the blood vessels, and the choroid. A multi-channel SLO combines the advantageous imaging properties of a tunable, monochrome SLO with the benefits and convenience of colour ophthalmoscopy. The options to modify parameters such as wavelength, intensity, gain, beam profile, aperture sizes, independently for every channel assign a high degree of versatility to the system. Copyright 1999 Wiley-Liss, Inc.

High-quality slab-based intermixing method for fusion rendering of multiple medical objects.

PubMed

Kim, Dong-Joon; Kim, Bohyoung; Lee, Jeongjin; Shin, Juneseuk; Kim, Kyoung Won; Shin, Yeong-Gil

2016-01-01

The visualization of multiple 3D objects has been increasingly required for recent applications in medical fields. Due to the heterogeneity in data representation or data configuration, it is difficult to efficiently render multiple medical objects in high quality. In this paper, we present a novel intermixing scheme for fusion rendering of multiple medical objects while preserving the real-time performance. First, we present an in-slab visibility interpolation method for the representation of subdivided slabs. Second, we introduce virtual zSlab, which extends an infinitely thin boundary (such as polygonal objects) into a slab with a finite thickness. Finally, based on virtual zSlab and in-slab visibility interpolation, we propose a slab-based visibility intermixing method with the newly proposed rendering pipeline. Experimental results demonstrate that the proposed method delivers more effective multiple-object renderings in terms of rendering quality, compared to conventional approaches. And proposed intermixing scheme provides high-quality intermixing results for the visualization of intersecting and overlapping surfaces by resolving aliasing and z-fighting problems. Moreover, two case studies are presented that apply the proposed method to the real clinical applications. These case studies manifest that the proposed method has the outstanding advantages of the rendering independency and reusability. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Unravelling Galaxy Components

NASA Astrophysics Data System (ADS)

Kennedy, Rebecca

2017-06-01

This thesis aims to understand more about the developmental histories of galaxies and their internal components by studying the wavelength dependence of their spatial structure. I use a large sample of low-redshift galaxies with optical–near-IR imaging from the GAMA survey, which have been fitted with Sérsic and Sérsic + exponential functions in nine wavebands simultaneously, using software developed by the MegaMorph project. The first section of this thesis examines how the sizes and radial profiles of galaxies vary with wavelength. To quantify the wavelength dependence of effective radius I use the ratio, R, of measurements in two restframe bands. The dependence of Sérsic index on wavelength, N, is computed correspondingly. I show that accounting for different redshift and luminosity selections partly reconciles variations between several recent studies. Dividing galaxies by visual morphology confirms the behaviour inferred using morphological proxies, although our quantitative measurements allow me to study larger and fainter samples. I then demonstrate that varying dust opacity and disc inclination can account for features of the joint distribution of R and N for late-type galaxies. However, dust does not appear to explain the highest values of R and N. The bulge-disc nature of galaxies must also contribute to the wavelength-dependence of their structure. The second section of this thesis studies radial colour gradients across the galaxy population. I use the multi-wavelength information provided by MegaMorph analysis of galaxy light profiles to calculate intrinsic colour gradients, and divide into six subsamples split by overall Sérsic index (n) and galaxy colour. I find a bimodality in the colour gradients of high- and low-n galaxies in all wavebands which varies with overall galaxy luminosity. Global trends in colour gradients therefore result from combining the contrasting behaviour of a number of different galaxy populations. The ubiquity of strong negative colour gradients supports the picture of inside-out growth through gas accretion for blue, low-n galaxies, and through dry minor mergers for red, high-n galaxies. An exception is the blue high-n population which has properties indicative of dissipative major mergers. In the third section of this thesis I apply bulge-disc decompositions to my sample of galaxies, in order to discover the structural origin of the wavelength dependences found in the previous two chapters. I find that most galaxies with a substantial disc, even those with no discernible bulge, display a high value of N. The increase in Sérsic index to longer wavelengths is therefore intrinsic to discs, apparently resulting from radial variations in stellar population and/or dust reddening. Similarly, low values of R (< 1) are found to be ubiquitous, implying an element of universality in galaxy colour gradients. I also study how bulge and disc colour distributions vary with galaxy type. I find that, rather than all bulges being red and all discs being blue in absolute terms, both components become redder for galaxies with redder total colours. I even observe that bulges in bluer galaxies are typically bluer than discs in red galaxies, and that bulges and discs are closer in colour for fainter galaxies. Trends in total colour are therefore not solely due to the colour or flux dominance of the bulge or disc.

Holi colours contain PM10 and can induce pro-inflammatory responses.

PubMed

Bossmann, Katrin; Bach, Sabine; Höflich, Conny; Valtanen, Kerttu; Heinze, Rita; Neumann, Anett; Straff, Wolfgang; Süring, Katrin

2016-01-01

At Holi festivals, originally celebrated in India but more recently all over the world, people throw coloured powder (Holi powder, Holi colour, Gulal powder) at each other. Adverse health effects, i.e. skin and ocular irritations as well as respiratory problems may be the consequences. The aim of this study was to uncover some of the underlying mechanisms. We analysed four different Holi colours regarding particle size using an Electric field cell counting system. In addition, we incubated native human cells with different Holi colours and determined their potential to induce a pro-inflammatory response by quantifying the resulting cytokine production by means of ELISA (Enzyme Linked Immunosorbent Assay) and the resulting leukocyte oxidative burst by flow cytometric analysis. Moreover, we performed the XTT (2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) and Propidium iodide cytotoxicity tests and we measured the endotoxin content of the Holi colour samples by means of the Limulus Amebocyte Lysate test (LAL test). We show here that all tested Holi colours consist to more than 40 % of particles with an aerodynamic diameter smaller than 10 μm, so called PM10 particles (PM, particulate matter). Two of the analysed Holi powders contained even more than 75 % of PM10 particles. Furthermore we demonstrate in cell culture experiments that Holi colours can induce the production of the pro-inflammatory cytokines TNF-α (Tumor necrosis factor-α), IL-6 (Interleukine-6) and IL-1β (Interleukine-1β). Three out of the four analysed colours induced a significantly higher cytokine response in human PBMCs (Peripheral Blood Mononuclear Cells) and whole blood than corn starch, which is often used as carrier substance for Holi colours. Moreover we show that corn starch and two Holi colours contain endotoxin and that certain Holi colours display concentration dependent cytotoxic effects in higher concentration. Furthermore we reveal that in principle Holi colours and corn starch are able to generate an oxidative burst in human granulocytes and monocytes. In Holi colour 1 we detected a fungal contamination. Some of the observed unwanted health effects of Holi colours might be explained by the high content of PM10 particles in conjunction with the possible induction of a pro-inflammatory response and an oxidative leukocyte burst.

Aqueous two-phase based on ionic liquid liquid-liquid microextraction for simultaneous determination of five synthetic food colourants in different food samples by high-performance liquid chromatography.

PubMed

Sha, Ou; Zhu, Xiashi; Feng, Yanli; Ma, Weixing

2015-05-01

A rapid and effective method of aqueous two-phase systems based on ionic liquid microextraction for the simultaneous determination of five synthetic food colourants (tartrazine, sunset yellow, amaranth, ponceau 4R and brilliant blue) in food samples was established. High-performance liquid chromatography coupled with an ultraviolet detector of variable wavelength was used for the determinations. 1-alkyl-3-methylimidazolium bromide was selected as the extraction reagent. The extraction efficiency of the five colourants in the proposed system is influenced by the types of salts, concentrations of salt and [CnMIM]Br, as well as the extracting time. Under the optimal conditions, the extraction efficiencies for these five colourants were above 95%. The phase behaviours of aqueous two-phase system and extraction mechanism were investigated by UV-vis spectroscopy. This method was applied to the analysis of the five colourants in real food samples with the detection limit of 0.051-0.074 ng/mL. Good spiked recoveries from 93.2% to 98.9% were obtained. Copyright © 2014 Elsevier Ltd. All rights reserved.

Rapid all-in-one three-step immunoassay for non-instrumental detection of ochratoxin A in high-coloured herbs and spices.

PubMed

Goryacheva, Irina Yu; De Saeger, Sarah; Nesterenko, Irina S; Eremin, Sergei A; Van Peteghem, Carlos

2007-05-15

A feasible three-step method for ochratoxin A (OTA) rapid detection was developed and applied for OTA screening in high-coloured matrices such as liquorice, ginger, nutmeg, black pepper, white pepper and Capsicum spp. spices at a control level of 10mugkg(-1). The method was based on the clean-up tandem immunoassay column and involved three steps: extract application, washing step and application of chromogenic substrate. A significant simplification of the assay was reached by using an additional frit with conjugate inside the clean-up tandem immunoassay column. The time for analysis was less than 10min, including 5min for colour development. Results were visually evaluated as colour development for negative result or no colour development for positive result. The method was coupled with a simple methanol-based extraction. A total of 27 samples were screened for OTA with the proposed method. It was shown that two samples of red pepper and one sample of liquorice, pili-pili, chilli and cayenne were contaminated with OTA above the control level at 10mugkg(-1), but none of tested ginger, nutmeg, black pepper and white pepper.

White light emitting device based on single-phase CdS quantum dots.

PubMed

Li, Feng; Nie, Chao; You, Lai; Jin, Xiao; Zhang, Qin; Qin, Yuancheng; Zhao, Feng; Song, Yinglin; Chen, Zhongping; Li, Qinghua

2018-05-18

White light emitting diodes (WLEDs) based on quantum dots (QDs) are emerging as robust candidates for white light sources, however they are suffering from the problem of energy loss resulting from the re-absorption and self-absorption among the employed QDs of different peak wavelengths. It still remains a challenging task to construct WLEDs based on single-phase QD emitters. Here, CdS QDs with short synthesis times are introduced to the fabrication of WLEDs. With a short synthesis time, on one hand, CdS QDs with a small diameter with blue emission can be obtained. On the other hand, surface reconstruction barely has time to occur, and the surface is likely defect-ridden, which enables the existence of a broad emission covering the range of green, yellow and red regions. This is essential for the white light emission of CdS QDs, and is very important for WLED applications. The temporal evolution of the PL spectra for CdS QDs was obtained to investigate the influence of growth time on the luminescent properties. The CdS QDs with a growth time of 0.5 min exhibited a colour rendering index (CRI) of 79.5 and a correlated colour temperature (CCT) of 6238 K. With increasing reaction time, the colour coordinates of the CdS QDs will move away from the white light region in the CIE 1931 chromaticity diagram. By integrating the as prepared white light emission CdS QDs with a violet GaN chip, WLEDs were fabricated. The fabricated WLEDs exhibited a CRI of 87.9 and a CCT of 4619 K, which satisfy the demand of general illumination. The luminous flux and the luminous efficiency of the fabricated WLEDs, being less advanced than current commercial white light sources, can be further improved, meaning there is a need for much more in-depth studies on white light emission CdS QDs.

White light emitting device based on single-phase CdS quantum dots

NASA Astrophysics Data System (ADS)

Li, Feng; Nie, Chao; You, Lai; Jin, Xiao; Zhang, Qin; Qin, Yuancheng; Zhao, Feng; Song, Yinglin; Chen, Zhongping; Li, Qinghua

2018-05-01

White light emitting diodes (WLEDs) based on quantum dots (QDs) are emerging as robust candidates for white light sources, however they are suffering from the problem of energy loss resulting from the re-absorption and self-absorption among the employed QDs of different peak wavelengths. It still remains a challenging task to construct WLEDs based on single-phase QD emitters. Here, CdS QDs with short synthesis times are introduced to the fabrication of WLEDs. With a short synthesis time, on one hand, CdS QDs with a small diameter with blue emission can be obtained. On the other hand, surface reconstruction barely has time to occur, and the surface is likely defect-ridden, which enables the existence of a broad emission covering the range of green, yellow and red regions. This is essential for the white light emission of CdS QDs, and is very important for WLED applications. The temporal evolution of the PL spectra for CdS QDs was obtained to investigate the influence of growth time on the luminescent properties. The CdS QDs with a growth time of 0.5 min exhibited a colour rendering index (CRI) of 79.5 and a correlated colour temperature (CCT) of 6238 K. With increasing reaction time, the colour coordinates of the CdS QDs will move away from the white light region in the CIE 1931 chromaticity diagram. By integrating the as prepared white light emission CdS QDs with a violet GaN chip, WLEDs were fabricated. The fabricated WLEDs exhibited a CRI of 87.9 and a CCT of 4619 K, which satisfy the demand of general illumination. The luminous flux and the luminous efficiency of the fabricated WLEDs, being less advanced than current commercial white light sources, can be further improved, meaning there is a need for much more in-depth studies on white light emission CdS QDs.

A chameleon-inspired stretchable electronic skin with interactive colour changing controlled by tactile sensing

PubMed Central

Chou, Ho-Hsiu; Nguyen, Amanda; Chortos, Alex; To, John W.F.; Lu, Chien; Mei, Jianguo; Kurosawa, Tadanori; Bae, Won-Gyu; Tok, Jeffrey B.-H.; Bao, Zhenan

2015-01-01

Some animals, such as the chameleon and cephalopod, have the remarkable capability to change their skin colour. This unique characteristic has long inspired scientists to develop materials and devices to mimic such a function. However, it requires the complex integration of stretchability, colour-changing and tactile sensing. Here we show an all-solution processed chameleon-inspired stretchable electronic skin (e-skin), in which the e-skin colour can easily be controlled through varying the applied pressure along with the applied pressure duration. As such, the e-skin's colour change can also be in turn utilized to distinguish the pressure applied. The integration of the stretchable, highly tunable resistive pressure sensor and the fully stretchable organic electrochromic device enables the demonstration of a stretchable electrochromically active e-skin with tactile-sensing control. This system will have wide range applications such as interactive wearable devices, artificial prosthetics and smart robots. PMID:26300307

Polarization-independent actively tunable colour generation on imprinted plasmonic surfaces

PubMed Central

Franklin, Daniel; Chen, Yuan; Vazquez-Guardado, Abraham; Modak, Sushrut; Boroumand, Javaneh; Xu, Daming; Wu, Shin-Tson; Chanda, Debashis

2015-01-01

Structural colour arising from nanostructured metallic surfaces offers many benefits compared to conventional pigmentation based display technologies, such as increased resolution and scalability of their optical response with structure dimensions. However, once these structures are fabricated their optical characteristics remain static, limiting their potential application. Here, by using a specially designed nanostructured plasmonic surface in conjunction with high birefringence liquid crystals, we demonstrate a tunable polarization-independent reflective surface where the colour of the surface is changed as a function of applied voltage. A large range of colour tunability is achieved over previous reports by utilizing an engineered surface which allows full liquid crystal reorientation while maximizing the overlap between plasmonic fields and liquid crystal. In combination with imprinted structures of varying periods, a full range of colours spanning the entire visible spectrum is achieved, paving the way towards dynamic pixels for reflective displays. PMID:26066375

A chameleon-inspired stretchable electronic skin with interactive colour changing controlled by tactile sensing.

PubMed

Chou, Ho-Hsiu; Nguyen, Amanda; Chortos, Alex; To, John W F; Lu, Chien; Mei, Jianguo; Kurosawa, Tadanori; Bae, Won-Gyu; Tok, Jeffrey B-H; Bao, Zhenan

2015-08-24

Some animals, such as the chameleon and cephalopod, have the remarkable capability to change their skin colour. This unique characteristic has long inspired scientists to develop materials and devices to mimic such a function. However, it requires the complex integration of stretchability, colour-changing and tactile sensing. Here we show an all-solution processed chameleon-inspired stretchable electronic skin (e-skin), in which the e-skin colour can easily be controlled through varying the applied pressure along with the applied pressure duration. As such, the e-skin's colour change can also be in turn utilized to distinguish the pressure applied. The integration of the stretchable, highly tunable resistive pressure sensor and the fully stretchable organic electrochromic device enables the demonstration of a stretchable electrochromically active e-skin with tactile-sensing control. This system will have wide range applications such as interactive wearable devices, artificial prosthetics and smart robots.

The influence of working memory on the anger superiority effect.

PubMed

Moriya, Jun; Koster, Ernst H W; De Raedt, Rudi

2014-01-01

The anger superiority effect shows that an angry face is detected more efficiently than a happy face. However, it is still controversial whether attentional allocation to angry faces is a bottom-up process or not. We investigated whether the anger superiority effect is influenced by top-down control, especially working memory (WM). Participants remembered a colour and then searched for differently coloured facial expressions. Just holding the colour information in WM did not modulate the anger superiority effect. However, when increasing the probabilities of trials in which the colour of a target face matched the colour held in WM, participants were inclined to direct attention to the target face regardless of the facial expression. Moreover, the knowledge of high probability of valid trials eliminated the anger superiority effect. These results suggest that the anger superiority effect is modulated by top-down effects of WM, the probability of events and expectancy about these probabilities.

Determination of HER2 amplification in primary breast cancer using dual-colour chromogenic in situ hybridization is comparable to fluorescence in situ hybridization: a European multicentre study involving 168 specimens.

PubMed

García-Caballero, Tomás; Grabau, Dorthe; Green, Andrew R; Gregory, John; Schad, Arno; Kohlwes, Elke; Ellis, Ian O; Watts, Sarah; Mollerup, Jens

2010-03-01

Fluorescence in situ hybridization (FISH) can be used to reveal several genomic imbalances relevant to proper cancer diagnosis and to the correct treatment regime. However, FISH requires expensive and advanced fluorescence microscopes in addition to expertise in fluorescence microscopy. To determine whether a newly developed dual-colour chromogenic in situ hybridization (CISH) method is a suitable alternative to FISH, we analysed the human epidermal growth factor receptor 2 gene (HER2) amplification level of 168 breast cancer specimens using dual-colour CISH and FISH and compared the results. We found 100% agreement between HER2 status determined by FISH and dual-colour CISH. Furthermore, we observed that the time used to score slides was significantly reduced by 28% in dual-colour CISH compared with the FISH protocol. Concordance between HER2 protein status and dual-colour CISH or FISH was equally good with an overall agreement of 96.8%. Correlation between the HER2/centromere 17 gene ratios obtained with dual-colour CISH and FISH was highly significant with an overall correlation coefficient (rho) of 0.96. We conclude that dual-colour CISH and bright field microscopy are excellent alternatives to FISH when analysing the HER2 status of primary breast cancer.

Molluscan shell colour.

PubMed

Williams, Suzanne T

2017-05-01

The phylum Mollusca is highly speciose, and is the largest phylum in the marine realm. The great majority of molluscs are shelled, including nearly all bivalves, most gastropods and some cephalopods. The fabulous and diverse colours and patterns of molluscan shells are widely recognised and have been appreciated for hundreds of years by collectors and scientists alike. They serve taxonomists as characters that can be used to recognise and distinguish species, however their function for the animal is sometimes less clear and has been the focus of many ecological and evolutionary studies. Despite these studies, almost nothing is known about the evolution of colour in molluscan shells. This review summarises for the first time major findings of disparate studies relevant to the evolution of shell colour in Mollusca and discusses the importance of colour, including the effects of visual and non-visual selection, diet and abiotic factors. I also summarise the evidence for the heritability of shell colour in some taxa and recent efforts to understand the molecular mechanisms underpinning synthesis of shell colours. I describe some of the main shell pigments found in Mollusca (carotenoids, melanin and tetrapyrroles, including porphyrins and bile pigments), and their durability in the fossil record. Finally I suggest that pigments appear to be distributed in a phylogenetically relevant manner and that the synthesis of colour is likely to be energetically costly. © 2016 Cambridge Philosophical Society.

Nutrition warnings as front-of-pack labels: influence of design features on healthfulness perception and attentional capture.

PubMed

Cabrera, Manuel; Machín, Leandro; Arrúa, Alejandra; Antúnez, Lucía; Curutchet, María Rosa; Giménez, Ana; Ares, Gastón

2017-12-01

Warnings are a new directive front-of-pack (FOP) nutrition labelling scheme that highlights products with high content of key nutrients. The design of warnings influences their ability to catch consumers' attention and to clearly communicate their intended meaning, which are key determinants of their effectiveness. The aim of the present work was to evaluate the influence of design features of warnings as a FOP nutrition labelling scheme on perceived healthfulness and attentional capture. Five studies with a total of 496 people were carried out. In the first study, the association of colour and perceived healthfulness was evaluated in an online survey in which participants had to rate their perceived healthfulness of eight colours. In the second study, the influence of colour, shape and textual information on perceived healthfulness was evaluated using choice-conjoint analysis. The third study focused on implicit associations between two design features (shape and colour) on perceived healthfulness. The fourth and fifth studies used visual search to evaluate the influence of colour, size and position of the warnings on attentional capture. Perceived healthfulness was significantly influenced by shape, colour and textual information. Colour was the variable with the largest contribution to perceived healthfulness. Colour, size and position of the warnings on the labels affected attentional capture. Results from the experiments provide recommendations for the design of warnings to identify products with unfavourable nutrient profile.

Balancing selection maintains cryptic colour morphs.

PubMed

Wellenreuther, Maren

2017-11-01

Animals display incredibly diverse colour patterns, a testament to evolution's endless innovation in shaping life. In many species, the interplay between males and females in the pursuit of mates has driven the evolution of a myriad of colour forms, from the flashy peacock tail feathers to the tiniest colour markings in damselflies. In others, colour provides crypsis by allowing to blend into the background and to escape the eyes of predators. While the obvious benefits of this dazzling diversity for reproduction and survival seem straightforward, its maintenance is not. Theory predicts that genetic drift and various forms of selection reduce variation over time, making the persistence of colour variants over generations a puzzle. In this issue of Molecular Ecology, Lindtke et al. () study the cryptic colour morphs of Timema cristinae walking sticks to shed light on the genetic architecture and mechanisms that allow colour polymorphism maintenance over long timescales. By combining genome-wide data with phenotyping information from natural populations, they were able to map the green and melanistic colour to one genomic region with highly reduced effective recombination rate between two main chromosomal variants, consistent with an inversion polymorphism. These two main chromosomal variants showed geographically widespread heterozygote excess, and genomic signatures consistent with long-term balancing selection. A younger chromosomal variant was detected for the third morph, the green-striped colour morphs, in the same genomic regions as the melanistic and the green-unstriped morphs. Together, these results suggest that the genetic architecture of cryptic T. cristinae morphs is caused by nonrecombining genomic blocks that have been maintained over extended time periods by balancing selection making this study one of the few available empirical examples documenting that balancing selection of various forms may play an important role in maintaining adaptive genetic variation in nature. © 2017 John Wiley & Sons Ltd.

The Border Star 85 Survey: Toward an Archeology of Landscapes

DTIC Science & Technology

1988-12-12

historic properties on that highly active military tire TRU method as implemented) were inadequate for installation. rendering determinations of National...Dofia Ana phase settlement, such required only minimal reporting sufficient to render Na- that one could speculate as to how and why variation among...this dependent upon precipitation. In normal or high rainfall sort are complicated, however, by factors that render them years there would be many

Total polyphenols, catechin profiles and antioxidant activity of tea products from purple leaf coloured tea cultivars.

PubMed

Kerio, L C; Wachira, F N; Wanyoko, J K; Rotich, M K

2013-02-15

Black (aerated) and green (unaerated) tea products, processed from 10 green and 18 purple leaf coloured cultivars of Kenyan origin, and two tea products, from the Japanese cultivars, Yabukita and Yutakamidori, were assayed for total polyphenols (TP) content, individual catechin profiles and in vitro antioxidant capacity (AA). In addition, the phenolic content of the tea products was determined using the Folin-Ciocalteu phenol reagent. Catechin fractions were identified using reverse phase high performance liquid chromatography (HPLC) with a binary gradient elution system. The AA% of the tea products was determined using a 2,2'-diphenyl picrylhydrazyl (DPPH) radical assay method. The results showed that TPs, catechin profiles and antioxidant activities were significantly (p≤0.05) higher in unaerated than in aerated teas. Tea products from the purple leaf coloured tea cultivars had levels of TPs, total catechin (TC) and antioxidant activities similar to those from the green leaf coloured cultivars, except for teas from the Japanese cultivars that were very low in the assayed parameters. Caffeine content was significantly (p≤0.05) lower in products from the purple leaf coloured cultivars than in those from the green leaf coloured tea cultivars. Antioxidant activity (%) was higher in tea products from the Kenyan germplasm than in those from the Japanese cultivars. Antioxidant potency of tea products was significantly (r=0.789(∗∗), p≤0.01) influenced by the total anthocyanin content of the purple leaf coloured cultivars. Cyanidin-3-O-glucoside was the anthocyanin most highly correlated with AA% (r=0.843(∗∗), p≤0.01 in unaerated tea). Total catechins in the unaerated products from the green leaf coloured tea cultivars were also significantly correlated with antioxidant capacity (r=0.818(∗∗), p≤0.01). Results from this study suggest that the antioxidant potency of teas is dependent on the predominant flavonoid compound, the type of tea cultivar and the processing method. Copyright © 2012 Elsevier Ltd. All rights reserved.

The structural coloration of textile materials using self-assembled silica nanoparticles

NASA Astrophysics Data System (ADS)

Gao, Weihong; Rigout, Muriel; Owens, Huw

2017-09-01

The work presented investigates how to produce structural colours on textile materials by applying a surface coating of silica nanoparticles (SNPs). Uniform SNPs with particle diameters in a controlled micron size range (207-350 nm) were synthesized using a Stöber-based solvent varying (SV) method which has been reported previously. Photonic crystals (PCs) were formed on the surface of a piece of textile fabric through a process of natural sedimentation self-assembly of the colloidal suspension containing uniform SNPs. Due to the uniformity and a particular diameter range of the prepared SNPs, structural colours were observed from the fabric surface due to the Bragg diffraction of white light with the ordered structure of the silica PCs. By varying the mean particle diameter, a wide range of spectral colours from red to blue were obtained. The comparison of structural colours on fabrics and on glasses suggests that a smooth substrate is critical when producing materials with high colour intensity and spatial uniformity. This work suggested a promising approach to colour textile materials without the need for traditional dyes and/or pigments. [Figure not available: see fulltext.

Strategies to limit colour changes when fortifying food products with iron.

PubMed

Habeych, Edwin; van Kogelenberg, Violet; Sagalowicz, Laurent; Michel, Martin; Galaffu, Nicola

2016-10-01

Iron, vitamin A, zinc and iodine have been recognized to be the micronutrients with the largest deficiencies worldwide. Among these, iron is highly reactive and may lead to negatively perceived organoleptic changes in products such as dull colour and off-taste. The colour change originated in fortified fruit-containing food products was confirmed to be the result of the complexation of iron and polyphenols. Phenolic compounds with two or more vicinal hydroxy benzyl moieties in their structure, such as catechols and pyrogallols were investigated for their ability to give bathochromic shift phenomena when mixed with iron salts. Furthermore, strategies for limiting colour development were based on: 1) pH adjustment; 2) saturation of polyphenols with unreactive divalent metal ions; 3) suppression of iron reactivity through complexation. Some of these strategies showed a significant improvement in colour stability, with the best results achieved by the latter. The findings in model systems gave a good insight of the mechanisms involved in colour changes, and results were transferable to iron fortified banana puree. Copyright © 2016 Elsevier Ltd. All rights reserved.

The structural coloration of textile materials using self-assembled silica nanoparticles.

PubMed

Gao, Weihong; Rigout, Muriel; Owens, Huw

2017-01-01

The work presented investigates how to produce structural colours on textile materials by applying a surface coating of silica nanoparticles (SNPs). Uniform SNPs with particle diameters in a controlled micron size range (207-350 nm) were synthesized using a Stöber-based solvent varying (SV) method which has been reported previously. Photonic crystals (PCs) were formed on the surface of a piece of textile fabric through a process of natural sedimentation self-assembly of the colloidal suspension containing uniform SNPs. Due to the uniformity and a particular diameter range of the prepared SNPs, structural colours were observed from the fabric surface due to the Bragg diffraction of white light with the ordered structure of the silica PCs. By varying the mean particle diameter, a wide range of spectral colours from red to blue were obtained. The comparison of structural colours on fabrics and on glasses suggests that a smooth substrate is critical when producing materials with high colour intensity and spatial uniformity. This work suggested a promising approach to colour textile materials without the need for traditional dyes and/or pigments. Graphical abstract.

OCoc- from Ocean Colour to Organic Carbon

NASA Astrophysics Data System (ADS)

Heim, B.; Overduin, P. P.; Schirrmeister, L.; Lantuit, H.; Doerffer, R.

2009-12-01

Enhanced permafrost warming and increased arctic river discharges have heightened concern about the input of terrigenous matter into Arctic coastal waters. The ‘OCoc-from Ocean Colour to Organic Carbon’ project (IPY-project 1176), funded by the German Research Foundation (DFG), is an Ocean Colour study joined with the Arctic Coastal Dynamics ACD network and Arctic Circum-polar Coastal Observatory Network ACCO-Net (IPY-project 90). OCoc uses Ocean Colour satellite data for synoptical monitoring of organic matter fluxes from fluvial and coastal sources. Initial results from German-Russian expeditions at the southeastern Laptev Sea Coast (Arctic Siberia, Russia) in August 2008 and August 2009 are presented. Large parts of this coastal zone are characterized by highly erosive organic-rich material. Ocean Colour MERIS Reduced Resolution (RR)-LIB data of the have been processed towards optical aquatic parameters using Beam-Visat4.2 and the MERIS case2 regional processor for coastal application (C2R). Calculated aquatic parameters are absorption and backscattering coefficients, apparent optical properties such as the first attenuation depth (‘Z90’) and calculated concentrations of chlorophyll, total suspended matter and coloured dissolved organic matter absorption from the water leaving reflectances. Initial comparisons with expedition data (Secchi depths, cDOM) show that the MERIS-C2R optical parameters ’total absorption’ and the first attenuation depth, ’Z90’, seem adequately to represent true conditions. High attenuation values in the spectral blue wavelength range may serve as tracer for the organic-rich terrigenous input. The synoptic information of Ocean Colour products will provide valuable spatial and dynamical information on the Organic Carbon and sediment fluxes from the Siberian permafrost coast.

Investigating the impact of age-depended hair colour darkening during childhood on DNA-based hair colour prediction with the HIrisPlex system.

PubMed

Kukla-Bartoszek, Magdalena; Pośpiech, Ewelina; Spólnicka, Magdalena; Karłowska-Pik, Joanna; Strapagiel, Dominik; Żądzińska, Elżbieta; Rosset, Iwona; Sobalska-Kwapis, Marta; Słomka, Marcin; Walsh, Susan; Kayser, Manfred; Sitek, Aneta; Branicki, Wojciech

2018-06-06

Predictive DNA analysis of externally visible characteristics exerts an increasing influence on contemporary forensic and anthropological investigations, with pigmentation traits currently being the most advanced for predictive modelling. Since pigmentation prediction error in some cases may be due to the result of age-related hair colour darkening, and sex influence in eye colour, this study aims to investigate these less explored phenomena on a group of juvenile individuals. Pigmentation phenotypes of children between the age of 6-13 years old were evaluated, in addition to data about their hair colour during early childhood from a select number of these individuals. The HIrisPlex models for DNA-based eye and hair colour prediction were used with input from SNP genotyping using massive parallel sequencing. Analysis of the total group of 476 children showed high accuracy in blue (AUC = 0.89) and brown (AUC = 0.91) eye colour prediction, while hair colour was predicted with AUC = 0.64 for blond, AUC = 0.64 for brown and AUC = 0.97 for red. 70.8% (n = 143) of the total number of children phenotypically blond for hair colour during early childhood progressed to brown during advanced childhood. In 70.6% (n = 101) of those cases, an incorrect blond hair prediction was made during the time of analysis. A noticeable decline in AUC values for blond (from 0.76 to 0.65) and brown (from 0.72 to 0.64) were observed when comparing hair colour prediction outcomes for the phenotypes recorded for the two different time points (at the age of 2-3 and 6-13). The number of incorrect blond hair colour predictions was significantly higher in children with brown hair at age 6-13 who were blond at early childhood (n = 47, 32.9%), relative to children who had brown hair at both time points (n = 6, 9.4%). However, in 28.0% (n = 40) of children who did experience hair colour darkening, HIrisPlex provided the correct prediction for the darkened hair colour phenotype, despite them being blond in early childhood. Our study implies that HIrisPlex can correctly predict adult hair colour in some individuals who experience age-related hair colour darkening during adolescence. However, in most instances prediction seems to default to the pre-adolescent hair colour for individuals with this phenomenon. In the future, the full adolescent age range in which hair colour darkening can occur should be considered in the study samples used for training hair colour prediction models to obtain a more complete picture of the phenomenon and its impact on DNA-based hair colour prediction in adults. Copyright © 2018 Elsevier B.V. All rights reserved.

Investment in testes, sperm-duct glands and lipid reserves differs between male morphs but not between early and late breeding season in Pomatoschistus minutus.

PubMed

Kvarnemo, C; Svensson, O; Manson, W

2010-05-01

This study of the sand goby Pomatoschistus minutus, a nest-holding fish with paternal care, focused on gonadal investment among males of different sizes collected early and late in the breeding season. All males caught at the nest had breeding colour, whereas trawl-caught fish consisted of males both with and without colour. The absence or presence of breeding colour was a good predictor of testes investment. Compared to males with breeding colour, males without colour were smaller in body size but had extraordinarily large testes. In absolute terms, testes mass of males without breeding colour was on average 3.4 times greater than those of males with breeding colour. Since small colourless males are known to reproduce as sneaker males, this heavy investment in testes probably reflects that they are forced to spawn under sperm competition. Contrary to testes size, sperm-duct glands were largest among males with breeding colour. These glands produce mucins used for making sperm-containing mucous trails that males place in the nest before and during spawning. Since both sneakers and nest-holders potentially could benefit from having large glands, this result is intriguing. Yet, high mucus production may be more important for nest-holders, because it also protects developing embryos from infections. There was no significant effect of season on body size, testes or sperm-duct glands size, but colourless males tended to be less common late in the season. Possibly this may indicate that individual small colourless males develop into their more colourful counterparts within the breeding season.

Rockpool Gobies Change Colour for Camouflage

PubMed Central

Stevens, Martin; Lown, Alice E.; Denton, Alexander M.

2014-01-01

Camouflage is found in a wide range of species living in numerous habitat types, offering protection from visually guided predators. This includes many species from the intertidal zone, which must cope with background types diverse in appearance and with multiple predator groups foraging at high and low tide. Many animals are capable of either relatively slow (hours, days, weeks) or rapid (seconds and minutes) colour change in order to better resemble the background against which they are found, but most work has been restricted to a few species or taxa. It is often suggested that many small intertidal fish are capable of colour change for camouflage, yet little experimental work has addressed this. Here, we test rock gobies (Gobius paganellus) for colour change abilities, and whether they can tune their appearance to match the background. In two experiments, we place gobies on backgrounds of different brightness (black or white), and of different colours (red and blue) and use digital image analysis and modelling of predator (avian) vision to quantify colour and luminance (perceived lightness) changes and camouflage. We find that gobies are capable of rapid colour change (occurring within one minute), and that they can change their luminance on lighter or darker backgrounds. When presented on backgrounds of different colours, gobies also change their colour (hue and saturation) while keeping luminance the same. These changes lead to predicted improvements in camouflage match to the background. Our study shows that small rockpool fish are capable of rapid visual change for concealment, and that this may be an important mechanism in many species to avoid predation, especially in complex heterogeneous environments. PMID:25333382

Rockpool gobies change colour for camouflage.

PubMed

Stevens, Martin; Lown, Alice E; Denton, Alexander M

2014-01-01

Camouflage is found in a wide range of species living in numerous habitat types, offering protection from visually guided predators. This includes many species from the intertidal zone, which must cope with background types diverse in appearance and with multiple predator groups foraging at high and low tide. Many animals are capable of either relatively slow (hours, days, weeks) or rapid (seconds and minutes) colour change in order to better resemble the background against which they are found, but most work has been restricted to a few species or taxa. It is often suggested that many small intertidal fish are capable of colour change for camouflage, yet little experimental work has addressed this. Here, we test rock gobies (Gobius paganellus) for colour change abilities, and whether they can tune their appearance to match the background. In two experiments, we place gobies on backgrounds of different brightness (black or white), and of different colours (red and blue) and use digital image analysis and modelling of predator (avian) vision to quantify colour and luminance (perceived lightness) changes and camouflage. We find that gobies are capable of rapid colour change (occurring within one minute), and that they can change their luminance on lighter or darker backgrounds. When presented on backgrounds of different colours, gobies also change their colour (hue and saturation) while keeping luminance the same. These changes lead to predicted improvements in camouflage match to the background. Our study shows that small rockpool fish are capable of rapid visual change for concealment, and that this may be an important mechanism in many species to avoid predation, especially in complex heterogeneous environments.

Ornament size and colour as alternative strategies for effective communication in gliding lizards.

PubMed

Klomp, D A; Ord, T J; Das, I; Diesmos, A; Ahmad, N; Stuart-Fox, D

2016-09-01

Sexual ornamentation needs to be conspicuous to be effective in attracting potential mates and defending territories and indeed, a multitude of ways exists to achieve this. Two principal mechanisms for increasing conspicuousness are to increase the ornament's colour or brightness contrast against the background and to increase the size of the ornament. We assessed the relationship between the colour and size of the dewlap, a large extendible throat-fan, across a range of species of gliding lizards (Agamidae; genus Draco) from Malaysia and the Philippines. We found a negative relationship across species between colour contrast against the background and dewlap size in males, but not in females, suggesting that males of different species use increasing colour contrast and dewlap size as alternative strategies for effective communication. Male dewlap size also increases with increasing sexual size dimorphism, and dewlap colour and brightness contrast increase with increasing sexual dichromatism in colour and brightness, respectively, suggesting that sexual selection may act on both dewlap size and colour. We further found evidence that relative predation intensity, as measured from predator attacks on models placed in the field, may play a role in the choice of strategy (high chromatic contrast or large dewlap area) a species employs. More broadly, these results highlight that each component in a signal (such as colour or size) may be influenced by different selection pressures and that by assessing components individually, we can gain a greater understanding of the evolution of signal diversity. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

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

Identification of Shell Colour Pigments in Marine Snails Clanculus pharaonius and C. margaritarius (Trochoidea; Gastropoda)

PubMed Central

Ito, S.; Wakamatsu, K.; Goral, T.; Edwards, N. P.; Wogelius, R. A.; Henkel, T.; de Oliveira, L. F. C.; Maia, L. F.; Strekopytov, S.; Speiser, D. I.; Marsden, J. T.

2016-01-01

Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ideally, in order to begin to understand the evolution and ecology of colour in nature, it is important to identify and, where possible, fully characterise pigments using biochemical methods. The phylum Mollusca includes some of the most beautiful exemplars of biological pigmentation, with the vivid colours of sea shells particularly prized by collectors and scientists alike. Biochemical studies of molluscan shell colour were fairly common in the last century, but few of these studies have been confirmed using modern methods and very few shell pigments have been fully characterised. Here, we use modern chemical and multi-modal spectroscopic techniques to identify two porphyrin pigments and eumelanin in the shell of marine snails Clanculus pharaonius and C margaritarius. The same porphyrins were also identified in coloured foot tissue of both species. We use high performance liquid chromatography (HPLC) to show definitively that these porphyrins are uroporphyrin I and uroporphyrin III. Evidence from confocal microscopy analyses shows that the distribution of porphyrin pigments corresponds to the striking pink-red of C. pharaonius shells, as well as pink-red dots and lines on the early whorls of C. margaritarius and yellow-brown colour of later whorls. Additional HPLC results suggest that eumelanin is likely responsible for black spots. We refer to the two differently coloured porphyrin pigments as trochopuniceus (pink-red) and trochoxouthos (yellow-brown) in order to distinguish between them. Trochopuniceus and trochoxouthos were not found in the shell of a third species of the same superfamily, Calliostoma zizyphinum, despite its superficially similar colouration, suggesting that this species has different shell pigments. These findings have important implications for the study of colour and pattern in molluscs specifically, but in other taxa more generally, since this study shows that homology of visible colour cannot be assumed without identification of pigments. PMID:27367426

Identification of Shell Colour Pigments in Marine Snails Clanculus pharaonius and C. margaritarius (Trochoidea; Gastropoda).

PubMed

Williams, S T; Ito, S; Wakamatsu, K; Goral, T; Edwards, N P; Wogelius, R A; Henkel, T; de Oliveira, L F C; Maia, L F; Strekopytov, S; Jeffries, T; Speiser, D I; Marsden, J T

2016-01-01

Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ideally, in order to begin to understand the evolution and ecology of colour in nature, it is important to identify and, where possible, fully characterise pigments using biochemical methods. The phylum Mollusca includes some of the most beautiful exemplars of biological pigmentation, with the vivid colours of sea shells particularly prized by collectors and scientists alike. Biochemical studies of molluscan shell colour were fairly common in the last century, but few of these studies have been confirmed using modern methods and very few shell pigments have been fully characterised. Here, we use modern chemical and multi-modal spectroscopic techniques to identify two porphyrin pigments and eumelanin in the shell of marine snails Clanculus pharaonius and C margaritarius. The same porphyrins were also identified in coloured foot tissue of both species. We use high performance liquid chromatography (HPLC) to show definitively that these porphyrins are uroporphyrin I and uroporphyrin III. Evidence from confocal microscopy analyses shows that the distribution of porphyrin pigments corresponds to the striking pink-red of C. pharaonius shells, as well as pink-red dots and lines on the early whorls of C. margaritarius and yellow-brown colour of later whorls. Additional HPLC results suggest that eumelanin is likely responsible for black spots. We refer to the two differently coloured porphyrin pigments as trochopuniceus (pink-red) and trochoxouthos (yellow-brown) in order to distinguish between them. Trochopuniceus and trochoxouthos were not found in the shell of a third species of the same superfamily, Calliostoma zizyphinum, despite its superficially similar colouration, suggesting that this species has different shell pigments. These findings have important implications for the study of colour and pattern in molluscs specifically, but in other taxa more generally, since this study shows that homology of visible colour cannot be assumed without identification of pigments.

The role of meaning in grapheme-colour synaesthesia.

PubMed

Dixon, Mike J; Smilek, Daniel; Duffy, Patricia L; Zanna, Mark P; Merikle, Philip M

2006-02-01

When the synaesthete, J, is shown black graphemes, in addition to perceiving the black digits or letters she also experiences highly specific colours that overlay the graphemes (e.g., 5 is pink, S is green). We used ambiguous graphemes in a Stroop-type task to show that the exact same forms (e.g., 5) can elicit different synaesthetic colours depending on whether they are interpreted as digits or letters. J was shown strings of black digits (e.g., 3 4 5 6 7) or words (e.g., M U S I C for 1 sec. All but one of the graphemes then disappeared and the remaining grapheme changed to a colour that J had to name as quickly as possible. The key trials involved coloured graphemes that were ambiguous (e.g., the 5 in the strings above could be interpreted either as a digit or as a letter). On congruent trials, the colour of the ambiguous target grapheme was the same as J's photism for the digit or letter interpretations of the grapheme. On incongruent trials, the colours of the ambiguous target graphemes were different than the colours of J's photisms for the digit or letter interpretations of the graphemes. On digit-context incongruent trials, the ambiguous graphemes were presented in J's colour for the letter-interpretations of the graphemes, whereas on letter-context incongruent trials, the ambiguous graphemes were presented in J's colours for the digit-interpretations of the graphemes. Thus the same ambiguous grapheme (e.g., a pink 5) served as a congruent stimulus in one context and an incongruent stimulus in another context. J's response times showed that ambiguous graphemes elicited different photisms depending on whether they were interpreted as digits or letters. This finding suggests that it is not the form but the meaning of graphemes (whether they are interpreted as digits or letters) that determines the colours of synaesthetic photisms.

A comparative study of fluorescent and LED lighting in industrial facilities

NASA Astrophysics Data System (ADS)

Perdahci PhD, C.; Akin BSc, H. C.; Cekic Msc, O.

2018-05-01

Industrial facilities have always been in search for reducing outgoings and minimizing energy consumption. Rapid developments in lighting technology require more energy efficient solutions not only for industries but also for many sectors and for households. Addition of solid-state technology has brought LED lamps into play and with LED lamp usage, efficacy level has reached its current values. Lighting systems which uses fluorescent and LED lamps have become the prior choice for many industrial facilities. This paper presents a comparative study about fluorescent and LED based indoor lighting systems for a warehouse building in an industrial facility in terms of lighting distribution values, colour rendering, power consumption, energy efficiency and visual comfort. Both scenarios have been modelled and simulated by using Relux and photometric data for the luminaires have been gathered by conducting tests and measurements in an accredited laboratory.

The effect of orthographic and emotional neighbourhood in a colour categorization task.

PubMed

Camblats, Anna-Malika; Mathey, Stéphanie

2016-02-01

This study investigated whether and how the strength of reading interference in a colour categorization task can be influenced by lexical competition and the emotional characteristics of words not directly presented. Previous findings showed inhibitory effects of high-frequency orthographic and emotional neighbourhood in the lexical decision task. Here, we examined the effect of orthographic neighbour frequency according to the emotional valence of the higher-frequency neighbour in an emotional orthographic Stroop paradigm. Stimuli were coloured neutral words that had either (1) no orthographic neighbour (e.g. PISTIL [pistil]), (2) one neutral higher-frequency neighbour (e.g. tirade [tirade]/TIRAGE [draw]) or (3) one negative higher-frequency neighbour (e.g. idiome [idiom]/IDIOTE [idiotic]). The results showed that colour categorization times were longer for words with no orthographic neighbour than for words with one neutral neighbour of higher frequency and even longer when the higher-frequency neighbour was neutral rather than negative. Thus, it appears not only that the orthographic neighbourhood of the coloured stimulus words intervenes in a colour categorization task, but also that the emotional content of the neighbour contributes to response times. These findings are discussed in terms of lexical competition between the stimulus word and non-presented orthographic neighbours, which in turn would modify the strength of reading interference on colour categorization times.

Pollinator responses to floral colour change, nectar, and scent promote reproductive fitness in Quisqualis indica (Combretaceae).

PubMed

Yan, Juan; Wang, Gang; Sui, Yi; Wang, Menglin; Zhang, Ling

2016-04-13

Floral colour change is visual signals for pollinators to avoid old flowers and increase pollination efficiency. Quisqualis indica flowers change colour from white to pink to red may be associated with a shift from moth to butterfly pollination. To test this hypothesis, we investigated Q. indica populations in Southwest China. Flowers secreted nectar continuously from the evening of anthesis until the following morning, then decreased gradually with floral colour change. The scent compounds in the three floral colour stages were similar; however, the scent composition was different, and the scent emission rate decreased from the white to red stage. Dichogamy in Q. indica prevents self-pollination and interference of male and female functions. Controlled pollinations demonstrated that this species is self-incompatible and needs pollinators for seed production. Different pollinators were attracted in each floral colour stage; mainly moths at night and bees and butterflies during the day. Observations of open-pollinated inflorescences showed that white flowers had a higher fruit set than pink or red flowers, indicating the high contribution of moths to reproductive success. We concluded that the nectar and scent secretion are related to floral colour change in Q. indica, in order to attract different pollinators and promote reproductive fitness.

Does temporal contiguity moderate contingency learning in a speeded performance task?

PubMed

Schmidt, James R; De Houwer, Jan

2012-01-01

In four experiments, we varied the time between the onset of distracting nonwords and target colour words in a word-word version of the colour-word contingency learning paradigm. Contingencies were created by pairing a distractor nonword more often with one target colour word than with other colour words. A contingency effect corresponds to faster responses to the target colour word on high-contingency trials (i.e., distractor nonword followed by the target colour word with which it appears most often) than on low-contingency trials (i.e., distractor nonword followed by a target colour word with which it appears only occasionally). Roughly equivalent-sized contingency effects were found at stimulus-onset asynchronies (SOAs) of 50, 250, and 450 ms in Experiment 1, and 50, 500, and 1,000 ms in Experiment 2. In Experiment 3, a contingency effect was observed at SOAs of -50, -200, and -350 ms. In Experiment 4, interstimulus interval (ISI) was varied along with SOA, and learning was equivalent for 200-, 700-, and 1,200-ms SOAs. Together, these experiments suggest that the distracting stimulus does not need to be presented in close temporal contiguity with the response to induce learning. Relations to past research on causal judgement and implications for further contingency learning research are discussed.

Ultrahigh field magnetic resonance and colour Doppler real-time fusion imaging of the orbit--a hybrid tool for assessment of choroidal melanoma.

PubMed

Walter, Uwe; Niendorf, Thoralf; Graessl, Andreas; Rieger, Jan; Krüger, Paul-Christian; Langner, Sönke; Guthoff, Rudolf F; Stachs, Oliver

2014-05-01

A combination of magnetic resonance images with real-time high-resolution ultrasound known as fusion imaging may improve ophthalmologic examination. This study was undertaken to evaluate the feasibility of orbital high-field magnetic resonance and real-time colour Doppler ultrasound image fusion and navigation. This case study, performed between April and June 2013, included one healthy man (age, 47 years) and two patients (one woman, 57 years; one man, 67 years) with choroidal melanomas. All cases underwent 7.0-T magnetic resonance imaging using a custom-made ocular imaging surface coil. The Digital Imaging and Communications in Medicine volume data set was then loaded into the ultrasound system for manual registration of the live ultrasound image and fusion imaging examination. Data registration, matching and then volume navigation were feasible in all cases. Fusion imaging provided real-time imaging capabilities and high tissue contrast of choroidal tumour and optic nerve. It also allowed adding a real-time colour Doppler signal on magnetic resonance images for assessment of vasculature of tumour and retrobulbar structures. The combination of orbital high-field magnetic resonance and colour Doppler ultrasound image fusion and navigation is feasible. Multimodal fusion imaging promises to foster assessment and monitoring of choroidal melanoma and optic nerve disorders. • Orbital magnetic resonance and colour Doppler ultrasound real-time fusion imaging is feasible • Fusion imaging combines the spatial and temporal resolution advantages of each modality • Magnetic resonance and ultrasound fusion imaging improves assessment of choroidal melanoma vascularisation.

Failure strength of the bovine caudal disc under internal hydrostatic pressure.

PubMed

Schechtman, Helio; Robertson, Peter A; Broom, Neil D

2006-01-01

The structure of the disc is both complex and inhomogeneous, and it functions as a successful load-bearing organ by virtue of the integration of its various structural regions. These same features also render it impossible to assess the failure strength of the disc from isolated tissue samples, which at best can only yield material properties. This study investigated the intrinsic failure strength of the intact bovine caudal disc under a simple mode of internal hydrostatic pressure. Using a hydraulic actuator, coloured hydrogel was injected under monitored pressure into the nucleus through a hollow screw insert which passed longitudinally through one of the attached vertebrae. Failure did not involve vertebra/endplate structures. Rather, failure of the disc annulus was indicated by the simultaneous manifestation of a sudden loss of gel pressure, a flood of gel colouration appearing in the outer annulus and audible fibrous tearing. A mean hydrostatic failure pressure of 18+/-3 MPa was observed which was approximated as a thick-wall hoop stress of 45+/-7 MPa. The experiment provides a measurement of the intrinsic strength of the disc using a method of internal hydrostatic loading which avoids any disruption of the complex architecture of the annular wall. Although the disc in vivo is subjected to a much more complex pattern of loading than is achieved using simple hydrostatic pressurization, this latter mode provides a useful tool for investigating alterations in intrinsic disc strength associated with prior loading history or degeneration.

Modelling memory colour region for preference colour reproduction

NASA Astrophysics Data System (ADS)

Zeng, Huanzhao; Luo, Ronnier

2010-01-01

Colour preference adjustment is an essential step for colour image enhancement and perceptual gamut mapping. In colour reproduction for pictorial images, properly shifting colours away from their colorimetric originals may produce more preferred colour reproduction result. Memory colours, as a portion of the colour regions for colour preference adjustment, are especially important for preference colour reproduction. Identifying memory colours or modelling the memory colour region is a basic step to study preferred memory colour enhancement. In this study, we first created gamut for each memory colour region represented as a convex hull, and then used the convex hull to guide mathematical modelling to formulate the colour region for colour enhancement.

The use of an ordinary colour scanner to fingerprint sediment sources in the South African Karoo.

PubMed

Pulley, Simon; Rowntree, Kate

2016-01-01

The widespread adoption of sediment fingerprinting methodologies for the purpose of catchment management has been restricted by the high cost of tracer analysis as well as the potential for significant uncertainties to be present in results. Sediment colour has shown potential to be an inexpensive tracer able to discriminate between sediment sources. However, at present colour has not been demonstrated to be conservative during sediment erosion and transport. Sediment particle size and organic matter have been shown to strongly affect sediment colour, introducing significant uncertainties associated with its use. This study aimed to assess the suitability of colour as a tracer when it is measured using a commercially available colour scanner. The use of hydrogen peroxide (H2O2) to decompose sediment-associated organic matter was assessed as a means of minimising uncertainty. The impact of particle size on the accurate use of colour signatures as a tracer was also assessed. It was concluded that colour performed comparably to mineral magnetic signatures and showed good potential for use as a tracer. The use of H2O2 pre-treatment and limitation of the analysis to either the <32 μm or the >32 μm fraction of the samples were indicated to be important methods to limit uncertainties associated with organic matter and particle size. The methods used were considerably more time and cost effective than the measurement of most conventional tracers. Copyright © 2015 Elsevier Ltd. All rights reserved.

Desorption of biocides from renders modified with acrylate and silicone.

PubMed

Styszko, Katarzyna; Bollmann, Ulla E; Wangler, Timothy P; Bester, Kai

2014-01-01

Biocides are used in the building industry to prevent algal, bacterial and fungal growth on polymericrenders and thus to protect buildings. However, these biocides are leached into the environment. To better understand this leaching, the sorption/desorption of biocides in polymeric renders was assessed. In this study the desorption constants of cybutryn, carbendazim, iodocarb, isoproturon, diuron, dichloro-N-octylisothiazolinone and tebuconazole towards acrylate and silicone based renders were assessed at different pH values. At pH 9.5 (porewater) the constants for an acrylate based render varied between 8 (isoproturon) and 9634 (iodocarb) and 3750 (dichloro-N-octylisothiazolinone), respectively. The values changed drastically with pH value. The results for the silicone based renders were in a similar range and usually the compounds with high sorption constants for one polymer also had high values for the other polymer. Comparison of the octanol water partitioning constants (Kow) with the render/water partitioning constants (Kd) revealed similarities, but no strong correlation. Adding higher amounts of polymer to the render material changed the equilibria for dichloro-N-octylisothiazolinone, tebuconazole, cybutryn, carbendazim but not for isoproturon and diuron. Copyright © 2013 Elsevier Ltd. All rights reserved.

Colour and spatial cueing in low-prevalence visual search.

PubMed

Russell, Nicholas C C; Kunar, Melina A

2012-01-01

In visual search, 30-40% of targets with a prevalence rate of 2% are missed, compared to 7% of targets with a prevalence rate of 50% (Wolfe, Horowitz, & Kenner, 2005). This "low-prevalence" (LP) effect is thought to occur as participants are making motor errors, changing their response criteria, and/or quitting their search too soon. We investigate whether colour and spatial cues, known to improve visual search when the target has a high prevalence (HP), benefit search when the target is rare. Experiments 1 and 2 showed that although knowledge of the target's colour reduces miss errors overall, it does not eliminate the LP effect as more targets were missed at LP than at HP. Furthermore, detection of a rare target is significantly impaired if it appears in an unexpected colour-more so than if the prevalence of the target is high (Experiment 2). Experiment 3 showed that, if a rare target is exogenously cued, target detection is improved but still impaired relative to high-prevalence conditions. Furthermore, if the cue is absent or invalid, the percentage of missed targets increases. Participants were given the option to correct motor errors in all three experiments, which reduced but did not eliminate the LP effect. The results suggest that although valid colour and spatial cues improve target detection, participants still miss more targets at LP than at HP. Furthermore, invalid cues at LP are very costly in terms of miss errors. We discuss our findings in relation to current theories and applications of LP search.

Analysing photonic structures in plants

PubMed Central

Vignolini, Silvia; Moyroud, Edwige; Glover, Beverley J.; Steiner, Ullrich

2013-01-01

The outer layers of a range of plant tissues, including flower petals, leaves and fruits, exhibit an intriguing variation of microscopic structures. Some of these structures include ordered periodic multilayers and diffraction gratings that give rise to interesting optical appearances. The colour arising from such structures is generally brighter than pigment-based colour. Here, we describe the main types of photonic structures found in plants and discuss the experimental approaches that can be used to analyse them. These experimental approaches allow identification of the physical mechanisms producing structural colours with a high degree of confidence. PMID:23883949

Enhanced attosecond pulse generation in the vacuum ultraviolet using a two-colour driving field for high harmonic generation

NASA Astrophysics Data System (ADS)

Matía-Hernando, P.; Witting, T.; Walke, D. J.; Marangos, J. P.; Tisch, J. W. G.

2018-03-01

High-harmonic radiation in the extreme ultraviolet and soft X-ray spectral regions can be used to generate attosecond pulses and to obtain structural and dynamic information in atoms and molecules. However, these sources typically suffer from a limited photon flux. An additional issue at lower photon energies is the appearance of satellites in the time domain, stemming from insufficient temporal gating and the spectral filtering required for the isolation of attosecond pulses. Such satellites limit the temporal resolution. The use of multi-colour driving fields has been proven to enhance the harmonic yield and provide additional control, using the relative delays between the different spectral components for waveform shaping. We describe here a two-colour high-harmonic source that combines a few-cycle near-infrared pulse with a multi-cycle second harmonic pulse, with both relative phase and carrier-envelope phase stabilization. We observe strong modulations in the harmonic flux, and present simulations and experimental results supporting the suppression of satellites in sub-femtosecond pulses at 20 eV compared to the single colour field case, an important requirement for attosecond pump-probe measurements.

Colour vision in AIDS patients without HIV retinopathy.

PubMed

Sommerhalder, J; Baglivo, E; Barbey, C; Hirschel, B; Roth, A; Pelizzone, M

1998-11-01

Patients suffering from AIDS develop ocular complications, the most frequent being HIV retinopathy. It is however not clear, if functional visual impairments can be observed as early indicators of ocular complications, before clinical diagnosis of HIV retinopathy is made at fundus examination. To address this issue, we measured colour vision in a group of 49 AIDS subjects with normal clinical fundi using the 'two equation method'. This method, combining red-green Rayleigh and the blue-green Moreland metameric matches, enables more complete and quantitative assessments of colour vision than those based on pigmentary tests. Data were collected on our computer controlled colorimeter and compared to those of normal subjects. While most AIDS subjects without HIV retinopathy demonstrated normal colour vision, a significant portion of them had wider matches than normal subjects (11% for the Rayleigh equation and 16% for the Moreland equation). Furthermore, matching ranges of the Moreland equation were significantly correlated with CD4 lymphocyte counts. Patients with low CD4 values tended to produce larger matching ranges than the patients with high CD4 values. A within subject study on 17 patients confirmed this trend and showed that the patients who increased/decreased their CD4 blood counts generally improved/impaired their colour discrimination in the Moreland match. No such correlation was found between the matching ranges of the Rayleigh equation and the CD4 counts. These results show that colour discrimination is slightly reduced in some AIDS subjects, although there are no detectable ocular complications. They also suggest two different types of colour vision impairments in AIDS patients without retinopathy: one reversible process affecting colour discrimination in the blue-green range; and another irreversible process affecting colour discrimination in the red-green range.

Applying colour science in colour design

NASA Astrophysics Data System (ADS)

Luo, Ming Ronnier

2006-06-01

Although colour science has been widely used in a variety of industries over the years, it has not been fully explored in the field of product design. This paper will initially introduce the three main application fields of colour science: colour specification, colour-difference evaluation and colour appearance modelling. By integrating these advanced colour technologies together with modern colour imaging devices such as display, camera, scanner and printer, some computer systems have been recently developed to assist designers for designing colour palettes through colour selection by means of a number of widely used colour order systems, for creating harmonised colour schemes via a categorical colour system, for generating emotion colours using various colour emotional scales and for facilitating colour naming via a colour-name library. All systems are also capable of providing accurate colour representation on displays and output to different imaging devices such as printers.

Influence of bottle storage time on colour, phenolic composition and sensory properties of sweet red wines.

PubMed

Marquez, Ana; Serratosa, Maria P; Merida, Julieta

2014-03-01

Changes in colour and phenolic composition in sweet red wines made from Merlot, Syrah and Tempranillo grapes were studied in order to assess the influence of bottle storage over a period of 12months. For this purpose, wine colour parameters, sensory analysis and concentrations of monomeric anthocyanins, pyranoanthocyanins, methylmethine-mediated condensation adducts, flavan3-ol derivatives and flavonols were measured. Hue increased and red colours decreased with the storage time, particularly over the first 3months. The concentrations of low molecular weight flavan-3-ol derivatives decreased with time due to the effect of their conversion into tannins of high molecular weight. In addition, the glycosylated flavonols decreased through hydrolysis to give the corresponding aglycones. Overall, the concentration of phenolic compounds decreased markedly with storage time, whereas the antioxidant activity in the wines remained constant throughout. A panel of expert tasters judged the colour, aroma and flavour of all initial and final wines to be acceptable. Copyright © 2013 Elsevier Ltd. All rights reserved.

Using shape to turn off blinking for two-colour multiexciton emission in CdSe/CdS tetrapods

NASA Astrophysics Data System (ADS)

Mishra, Nimai; Orfield, Noah J.; Wang, Feng; Hu, Zhongjian; Krishnamurthy, Sachidananda; Malko, Anton V.; Casson, Joanna L.; Htoon, Han; Sykora, Milan; Hollingsworth, Jennifer A.

2017-05-01

Semiconductor nanostructures capable of emitting from two excited states and thereby of producing two photoluminescence colours are of fundamental and potential technological significance. In this limited class of nanocrystals, CdSe/CdS core/arm tetrapods exhibit the unusual trait of two-colour (red and green) multiexcitonic emission, with green emission from the CdS arms emerging only at high excitation fluences. Here we show that by synthetic shape-tuning, both this multi-colour emission process, and blinking and photobleaching behaviours of single tetrapods can be controlled. Specifically, we find that the properties of dual emission and single-nanostructure photostability depend on different structural parameters--arm length and arm diameter, respectively--but that both properties can be realized in the same nanostructure. Furthermore, based on results of correlated photoluminescence and transient absorption measurements, we conclude that hole-trap filling in the arms and partial state-filling in the core are necessary preconditions for the observation of multiexciton multi-colour emission.

Using shape to turn off blinking for two-colour multiexciton emission in CdSe/CdS tetrapods

PubMed Central

Mishra, Nimai; Orfield, Noah J.; Wang, Feng; Hu, Zhongjian; Krishnamurthy, Sachidananda; Malko, Anton V.; Casson, Joanna L.; Htoon, Han; Sykora, Milan; Hollingsworth, Jennifer A.

2017-01-01

Semiconductor nanostructures capable of emitting from two excited states and thereby of producing two photoluminescence colours are of fundamental and potential technological significance. In this limited class of nanocrystals, CdSe/CdS core/arm tetrapods exhibit the unusual trait of two-colour (red and green) multiexcitonic emission, with green emission from the CdS arms emerging only at high excitation fluences. Here we show that by synthetic shape-tuning, both this multi-colour emission process, and blinking and photobleaching behaviours of single tetrapods can be controlled. Specifically, we find that the properties of dual emission and single-nanostructure photostability depend on different structural parameters—arm length and arm diameter, respectively—but that both properties can be realized in the same nanostructure. Furthermore, based on results of correlated photoluminescence and transient absorption measurements, we conclude that hole-trap filling in the arms and partial state-filling in the core are necessary preconditions for the observation of multiexciton multi-colour emission. PMID:28497776

Using shape to turn off blinking for two-colour multiexciton emission in CdSe/CdS tetrapods

DOE PAGES

Mishra, Nimai; Orfield, Noah Jeremiah; Wang, Feng; ...

2017-05-12

Here, semiconductor nanostructures capable of emitting from two excited states and thereby of producing two photoluminescence colours are of fundamental and potential technological significance. In this limited class of nanocrystals, CdSe/CdS core/arm tetrapods exhibit the unusual trait of two-colour (red and green) multiexcitonic emission, with green emission from the CdS arms emerging only at high excitation fluences. Here we show that by synthetic shape-tuning, both this multi-colour emission process, and blinking and photobleaching behaviours of single tetrapods can be controlled. Specifically, we find that the properties of dual emission and single-nanostructure photostability depend on different structural parameters—arm length and armmore » diameter, respectively—but that both properties can be realized in the same nanostructure. Furthermore, based on results of correlated photoluminescence and transient absorption measurements, we conclude that hole-trap filling in the arms and partial state-filling in the core are necessary preconditions for the observation of multiexciton multi-colour emission.« less

Using shape to turn off blinking for two-colour multiexciton emission in CdSe/CdS tetrapods

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

Mishra, Nimai; Orfield, Noah Jeremiah; Wang, Feng

Here, semiconductor nanostructures capable of emitting from two excited states and thereby of producing two photoluminescence colours are of fundamental and potential technological significance. In this limited class of nanocrystals, CdSe/CdS core/arm tetrapods exhibit the unusual trait of two-colour (red and green) multiexcitonic emission, with green emission from the CdS arms emerging only at high excitation fluences. Here we show that by synthetic shape-tuning, both this multi-colour emission process, and blinking and photobleaching behaviours of single tetrapods can be controlled. Specifically, we find that the properties of dual emission and single-nanostructure photostability depend on different structural parameters—arm length and armmore » diameter, respectively—but that both properties can be realized in the same nanostructure. Furthermore, based on results of correlated photoluminescence and transient absorption measurements, we conclude that hole-trap filling in the arms and partial state-filling in the core are necessary preconditions for the observation of multiexciton multi-colour emission.« less

Developments in the recovery of colour in fine art prints using spatial image processing

NASA Astrophysics Data System (ADS)

Rizzi, A.; Parraman, C.

2010-06-01

Printmakers have at their disposal a wide range of colour printing processes. The majority of artists will utilise high quality materials with the expectation that the best materials and pigments will ensure image permanence. However, as many artists have experienced, this is not always the case. Inks, papers and materials can deteriorate over time. For artists and conservators who need to restore colour or tone to a print could benefit from the assistance of spatial colour enhancement tools. This paper studies two collections from the same edition of fine art prints that were made in 1991. The first edition has been kept in an archive and not exposed to light. The second edition has been framed and exposed to light for about 18 years. Previous experiments using colour enhancement methods [9,10] have involved a series of photographs that had been taken under poor or extreme lighting conditions, fine art works, scanned works. There are a range of colour enhancement methods: Retinex, RSR, ACE, Histogram Equalisation, Auto Levels, which are described in this paper. In this paper we will concentrate on the ACE algorithm and use a range of parameters to process the printed images and describe these results.

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.

True and false memory for colour names versus actual colours: support for the visual distinctiveness heuristic in memory for colour information.

PubMed

Eslick, Andrea N; Kostic, Bogdan; Cleary, Anne M

2010-06-01

In a colour variation of the Deese-Roediger-McDermott (DRM) false memory paradigm, participants studied lists of words critically related to a nonstudied colour name (e.g., "blood, cherry, scarlet, rouge ... "); they later showed false memory for the critical colour name (e.g., "red"). Two additional experiments suggest that participants generate colour imagery in response to such colour-related DRM lists. First, participants claim to experience colour imagery more often following colour-related than standard non-colour-related DRM lists; they also rate their colour imagery as more vivid following colour-related lists. Second, participants exhibit facilitative priming for critical colours in a dot selection task that follows words in the colour-related DRM list, suggesting that colour-related DRM lists prime participants for the actual critical colours themselves. Despite these findings, false memory for critical colour names does not extend to the actual colours themselves (font colours). Rather than leading to source confusion about which colours were self-generated and which were studied, presenting the study lists in varied font colours actually worked to reduce false memory overall. Results are interpreted within the framework of the visual distinctiveness hypothesis.

Poseidon's paintbox : historical archives of ocean colour in global-change perspective

NASA Astrophysics Data System (ADS)

Wernand, M. R.

2011-11-01

In the thesis introduction issues are discussed on the historical background of marine optics and on marine optical devices that were used over the past centuries to observe and measure; as in all sciences, in marine optics we can see a steady development: that of ‘measuring’, beginning many centuries ago, to 'knowing' and since less than a century to the understanding of the phenomenon. Hereafter, six themes are treated successively. The first theme, ‘Ocean optics from 1600 (Hudson) to 1930 (Raman), shift in interpretation of natural water colouring’, addresses the question of why it took so long a time to explain the phenomenon ‘the colouring of the sea’, especially the blue colour, despite the age-long interest of sailors, for practical purposes of navigation and detection of fish - of which more later. The second theme ‘On the history of the Secchi disc’, describes the search to establish methods for the determination of (sea) water clarity concerning purposes of navigation (near coast colour changes) just mentioned to detect shoals, and for a more basic purpose, tracing lost objects. The search to determine the clarity of lakes and seas culminated in the invention of the Secchi disc, used since the late 19th century. The third theme, ‘Spectral analysis of the Forel-Ule ocean colour comparator scale’, addresses the accuracy of a colour scale proposed, used in limnology and oceanography. Scale observations are put into perspective with contemporary measurements on the colour of the sea. The fourth theme, ‘Ocean colour changes in the North Pacific since 1930’, handles the question whether long-term ocean colour changes using historic Forel-Ule observations, in this part of the ocean made very frequently over time, can be determined in relation to global change. In principal global warming may cause a gradual change in ocean colour due to the effect of biological, chemical and physical aspects of the ocean-surface. The fifth theme, ‘MERIS-based ocean colour classification using the Forel-Ule scale’, addresses the question whether a relation can be established between the old Forel-Ule methodology, the classification of ocean colour by means of one of the scale colours, and the more recent satellite ocean colour methodology. The sixth theme, ‘Trends in ocean colour and chlorophyll concentration since 1889 to present’, addresses decadal colour changes per ocean and sea, using the longest available Forel-Ule dataset and confirms the possibility to transform these colour changes into chlorophyll concentration (indicative of the biomass of marine planktonic microalgae) changes. Such a transformation is needed to provide a link to the present in which chlorophyll concentrations are determined by using new technologies such as satellite remote sensing calibrated with high-performance liquid chromatography (HPLC) pigment analysis to determine marine microalgae pigments.

Colour Preference to Emotions in Relation to the Anxiety Level among School Children in Puducherry – A Cross-Sectional Study

PubMed Central

Prathima, Gajula Shivashankarappa; Sajeev, Renganathan; Kayalvizhi, Gurusamy; Ramesh, Venkatesan; Ezhumalai, Govindasamy

2016-01-01

Introduction Dental setting plays an important role in child’s behavior and cooperation to the planned dental treatment. Adding attractive colours to the dental environment and by incorporating colourful equipments can make the child feel good and be at ease. This study tries to convey the relationship between colours and dental anxiety among children. Aim To evaluate the colour preference to emotions in relation to children’s age, gender and anxiety level. Materials and Methods A total of 382 children aged 6-12 years were randomly selected from schools in and around Puducherry. Modified dental anxiety scale was recorded by a calibrated examiner. Each question was scored from one (not anxious) to five (extremely anxious); such that the total score ranges from 5 to 25, wherein a score of 15 or more was considered to be anxious. Based on this, children were divided into anxious and non-anxious groups. All the children were provided with eight different coloured crayon pencils and were asked to shade two cartoon emoticons indicating happiness and sadness with their preferred colour. Values were tabulated and statistically analyzed to evaluate the association between the variables using Z test, Chi-square, Chi-square goodness of fit and odds ratio. (p≤0.05 was considered statistically significant). Results Among 382 children, 77% (294) were graded as anxious and 23% (88) as non- anxious. For positive emotion (happiness), 31.2% (119) children preferred blue followed by pink 29.3% (112). For negative emotion (sadness), 52.1% (199) of children preferred black and 46.9% (179) preferred red. Association between colour and emotion was highly significant (p= 0.005). Conclusion From the colours preferred by the children in our study, it can be concluded that colours like blue and pink in the dental set-up could enhance a positive attitude while black and red could develop a negative outlook in their mind. PMID:27630948

Colour Preference to Emotions in Relation to the Anxiety Level among School Children in Puducherry - A Cross-Sectional Study.

PubMed

Annamary, Kattakayam; Prathima, Gajula Shivashankarappa; Sajeev, Renganathan; Kayalvizhi, Gurusamy; Ramesh, Venkatesan; Ezhumalai, Govindasamy

2016-07-01

Dental setting plays an important role in child's behavior and cooperation to the planned dental treatment. Adding attractive colours to the dental environment and by incorporating colourful equipments can make the child feel good and be at ease. This study tries to convey the relationship between colours and dental anxiety among children. To evaluate the colour preference to emotions in relation to children's age, gender and anxiety level. A total of 382 children aged 6-12 years were randomly selected from schools in and around Puducherry. Modified dental anxiety scale was recorded by a calibrated examiner. Each question was scored from one (not anxious) to five (extremely anxious); such that the total score ranges from 5 to 25, wherein a score of 15 or more was considered to be anxious. Based on this, children were divided into anxious and non-anxious groups. All the children were provided with eight different coloured crayon pencils and were asked to shade two cartoon emoticons indicating happiness and sadness with their preferred colour. Values were tabulated and statistically analyzed to evaluate the association between the variables using Z test, Chi-square, Chi-square goodness of fit and odds ratio. (p≤0.05 was considered statistically significant). Among 382 children, 77% (294) were graded as anxious and 23% (88) as non- anxious. For positive emotion (happiness), 31.2% (119) children preferred blue followed by pink 29.3% (112). For negative emotion (sadness), 52.1% (199) of children preferred black and 46.9% (179) preferred red. Association between colour and emotion was highly significant (p= 0.005). From the colours preferred by the children in our study, it can be concluded that colours like blue and pink in the dental set-up could enhance a positive attitude while black and red could develop a negative outlook in their mind.

GEMAS: Colours of dry and moist agricultural soil samples of Europe

NASA Astrophysics Data System (ADS)

Klug, Martin; Fabian, Karl; Reimann, Clemens

2016-04-01

High resolution HDR colour images of all Ap samples from the GEMAS survey were acquired using a GeoTek Linescan camera. Three measurements of dry and wet samples with increasing exposure time and increasing illumination settings produced a set of colour images at 50μm resolution. Automated image processing was used to calibrate the six images per sample with respect to the synchronously measured X-Rite colorchecker chart. The calibrated images were then fit to Munsell soil colours that were measured in the same way. The results provide overview maps of dry and moist European soil colours. Because colour is closely linked to iron mineralogy, carbonate, silicate and organic carbon content the results can be correlated to magnetic, mineralogical, and geochemical properties. In combination with the full GEMAS chemical and physical measurements, this yields a valuable data set for calibration and interpretation of visible satellite colour data with respect to chemical composition and geological background, soil moisture, and soil degradation. This data set will help to develop new methods for world-wide characterization and monitoring of agricultural soils which is essential for quantifying geologic and human impact on the critical zone environment. It furthermore enables the scientific community and governmental authorities to monitor consequences of climatic change, to plan and administrate economic and ecological land use, and to use the data set for forensic applications.

Highly-sensitive electrochemical sensing platforms for food colourants based on the property-tuning of porous carbon.

PubMed

Cheng, Qin; Xia, Shanhong; Tong, Jianhua; Wu, Kangbing

2015-08-05

It is very challenging to develop highly-sensitive analytical platforms for toxic synthetic colourants that widely added in food samples. Herein, a series of porous carbon (PC) was prepared using CaCO3 nanoparticles (nano-CaCO3) as the hard template and starch as the carbon precursor. Characterizations of scanning electron microscopy and transmission electron microscopy indicated that the morphology and porous structure were controlled by the weight ratio of starch and nano-CaCO3. The electrochemical behaviours of four kinds of widely-used food colourants, Sunset yellow, Tartrazine, Ponceau 4R and Allura red, were studied. On the surface of PC samples, the oxidation signals of colourants enhanced obviously, and more importantly, the signal enhancement abilities of PC were also dependent on the starch/nano-CaCO3 weight ratio. The greatly-increased electron transfer ability and accumulation efficiency were the main reason for the enhanced signals of colourants, as confirmed by electrochemical impedance spectroscopy and chronocoulometry. The prepared PC-2 sample by 1:1 starch/nano-CaCO3 weight ratio was more active for the oxidation of food colourtants, and increased the signals by 89.4-fold, 79.3-fold, 47.3-fold and 50.7-fold for Sunset yellow, Tartrazine, Ponceau 4R and Allura red. As a result, a highly-sensitive electrochemical sensing platform was developed, and the detection limits were 1.4, 3.5, 2.1 and 1.7 μg L(-1) for Sunset yellow, Tartrazine, Ponceau 4R and Allura red. The practical application of this new sensing platform was demonstrated using drink samples, and the detected results consisted with the values that obtained by high-performance liquid chromatography. Copyright © 2015 Elsevier B.V. All rights reserved.

Protoclusters with evolved populations around radio galaxies at z ~ 2.5

NASA Astrophysics Data System (ADS)

Kajisawa, Masaru; Kodama, Tadayuki; Tanaka, Ichi; Yamada, Toru; Bower, Richard

2006-09-01

We report the discovery of protocluster candidates around high-redshift radio galaxies at z ~ 2.5 on the basis of clear statistical excess of colour-selected galaxies around them seen in the deep near-infrared imaging data obtained with CISCO on the Subaru Telescope. We have observed six targets, all at similar redshifts at z ~ 2.5, and our data reach J = 23.5, H = 22.6 and K = 21.8 (5σ) and cover a 1.6 × 1.6 arcmin2 field centred on each radio galaxy. We apply colour cuts in JHK bands in order to exclusively search for galaxies located at high redshifts, z > 2. Over the magnitude range of 19.5 < K < 21.5, we see a significant excess of red galaxies with J - K > 2.3 by a factor of 2 around the combined radio galaxies fields compared to those found in the general field of the Great Observatories Origins Deep Survey-South (GOODS-S). The excess of galaxies around the radio galaxies fields becomes more than a factor of 3 around 19.5 < K < 20.5 when the two-colour cuts are applied with JHK bands. Such overdensity of the colour-selected galaxies suggests that those fields tend to host high-density regions at high redshifts, although there seems to be the variety of the density of the colour-selected galaxies in each field. In particular, two radio galaxies fields out of the six observed fields show very strong density excess and these are likely to be protoclusters associated with the radio galaxies which would evolve into rich clusters of galaxies dominated by old passively evolving galaxies.

Bad Colourmaps Can Hide Big Structures

NASA Astrophysics Data System (ADS)

Kovesi, Peter

2014-05-01

Colourmaps are often selected with little awareness of the perceptual distortions they might introduce. A colourmap can be thought of as a line or curve drawn through a three dimensional colour space. Individual data values are mapped to positions along this line which, in turn, allows them to be mapped to a colour. For a colourmap to be effective it is important that the perceptual contrast that occurs as one moves along the line in the colour space is close to uniform. Many colourmaps are designed as piecewise linear paths through RGB space. This is a poor colour space to use because it is not perceptually uniform. Accordingly many colourmaps supplied by vendors have uneven perceptual contrast over their range. They may include points of locally high colour contrast leading you to think there might be some anomaly in your data when there is none. Conversely, colourmaps may also have flat spots of low perceptual contrast that prevent you from seeing features in your data. In some cases it is possible for structures having a magnitude of 10% of the full data range to be completely hidden by a flat spot in the colourmap. The deficiencies of many colourmaps can be revealed using a simple test image consisting of a high frequency sine wave superimposed on a ramp function. The amplitude of the sine wave is modulated from a maximum value at the top of the image to zero at the bottom. Ideally the sine wave should be uniformly visible across the image at all points on the ramp. For many colourmaps this will not be the case. At the very bottom of the image, where the sine wave amplitude has been modulated to 0, we just have a linear ramp which simply reproduces the colourmap. Given that the underlying data is a featureless ramp the colourmap should not induce the perception of any features across the bottom of the test image. Good colourmaps are difficult to design. A greyscale colourmap is generally a safe choice but is not always what is desired. For non-greyscale colourmaps the perceptual colour contrast between adjacent entries of the map should be constant across the whole colourmap. In addition, and more importantly, the colour lightness change between successive entries in the colourmap should also be constant. These conditions, if observed, constrain the design of colourmaps considerably, and they exclude the construction of rainbow style colourmaps. It is shown that good colourmaps can be formed from smooth curves constructed in a perceptually uniform colour space such as CIELAB. Colour lightness values should be monotonically increasing at a constant rate while at the same time the colourmap curve should stay close to the boundary of the colour space gamut to ensure that the colours are vivid.

Does colour preference have a role in colour term acquisition?

PubMed

Pitchford, Nicola J; Davis, Emma E; Scerif, Gaia

2009-11-01

A developmental association exists between colour preference and emerging colour term acquisition in young children. Colour preference might influence colour term acquisition by directing attention towards or away from a particular colour, making it more or less memorable. To investigate the role that colour preference may have in the acquisition of colour terms, experimental tasks of colour preference, discrimination, attention, memory, and new colour term learning, were given to three groups of participants (preschool children; primary school children; and adults). Each task utilized the same colour stimuli, which were four computer-simulated colours, matched perceptually to four different Munsell chips, drawn from the same colour category. Three colours varied systematically from an anchor colour (10PB 4/8) only in saturation (10PB 4/4), luminance (10PB 6/8), or hue (5P 4/8). Results showed that within-category colour preferences emerged with age, and that when established within individuals, most preferred colours were named significantly more accurately than least preferred colours, although this association did not appear to be mediated directly by attention or memory. Rather, perceptual saliency was shown to have a mediating role, to some extent, in determining the relationship between colour preference and the cognitive processing of colour.

Limited mate availability decreases reproductive success of fragmented populations of Linnaea borealis, a rare, clonal self-incompatible plant

PubMed Central

Scobie, A. R.; Wilcock, C. C.

2009-01-01

Background and Aims Small populations of rare plant species are increasingly reported to have high levels of reproductive failure. The objective of this study was to understand the principal constraints on sexual reproduction in small fragmented populations of a rare clonal self-incompatible plant. Methods The pollinator spectrum, diversity of flower colour, natural pollination and fruit-set levels of L. borealis were examined in Scotland. Artificially crossed seed production was compared within and between different flower colour types and patches. Key Results Linnaea borealis was pollinated by a diverse spectrum of insect species and the principal pollinators were muscid, syrphid and empid flies which mostly moved only small distances (<0·25 m) between flowers when foraging. Natural pollination levels were high, indicating high pollinator effectiveness, but fruit set was very low in most patches. Flower colour diversity was low in most patches and only those with a diversity of flower colour types had high fruiting success. Pollination experiments showed L. borealis to be highly self-incompatible and artificial crosses within and between patches and flower colour types confirmed that low fruit success was the result of a lack of compatible mates and limited pollen movement between them. Evidence of isolation from pollen exchange was apparent at as little as 6 m and severe at 30 m and beyond. Conclusions Limited mate availability and isolation from pollen exchange compromise the reproductive success of fragmented populations of L. borealis in Scotland. A diversity of compatible mates situated within close proximity (<6 m) is the key requirement to ensure high natural fruiting success. This study emphasizes that an understanding of the breeding system, pollinator spectrum and potential for interconnectivity via pollinator movement are fundamental to identify isolation distances and to establish when conservation intervention is necessary for rare species. PMID:19181748

HRSCview: a web-based data exploration system for the Mars Express HRSC instrument

NASA Astrophysics Data System (ADS)

Michael, G.; Walter, S.; Neukum, G.

2007-08-01

The High Resolution Stereo Camera (HRSC) on the ESA Mars Express spacecraft has been orbiting Mars since January 2004. By spring 2007 it had returned around 2 terabytes of image data, covering around 35% of the Martian surface in stereo and colour at a resolu-tion of 10-20 m/pixel. HRSCview provides a rapid means to explore these images up to their full resolu-tion with the data-subsetting, sub-sampling, stretching and compositing being carried out on-the-fly by the image server. It is a joint website of the Free University of Berlin and the German Aerospace Center (DLR). The system operates by on-the-fly processing of the six HRSC level-4 image products: the map-projected ortho-rectified nadir pan-chromatic and four colour channels, and the stereo-derived DTM (digital terrain model). The user generates a request via the web-page for an image with several parameters: the centre of the view in surface coordinates, the image resolution in metres/pixel, the image dimensions, and one of several colour modes. If there is HRSC coverage at the given location, the necessary segments are extracted from the full orbit images, resampled to the required resolution, and composited according to the user's choice. In all modes the nadir channel, which has the highest resolu-tion, is included in the composite so that the maximum detail is always retained. The images are stretched ac-cording to the current view: this applies to the eleva-tion colour scale, as well as the nadir brightness and the colour channels. There are modes for raw colour, stretched colour, enhanced colour (exaggerated colour differences), and a synthetic 'Mars-like' colour stretch. A colour ratio mode is given as an alternative way to examine colour differences (R=IR/R, G=R/G and B=G/B). The final image is packaged as a JPEG file and returned to the user over the web. Each request requires approximately 1 second to process. A link is provided from each view to a data product page, where header items describing the full map-projected science data product are displayed, and a direct link to the archived data products on the ESA Planetary Science Archive (PSA) is provided. At pre-sent the majority of the elevation composites are de-rived from the HRSC Preliminary 200m DTMs gener-ated at the German Aerospace Center (DLR), which will not be available as separately downloadable data products. These DTMs are being progressively super-seded by systematically generated higher resolution archival DTMs, also from DLR, which will become available for download through the PSA, and be simi-larly accessible via HRSCview. At the time of writing this abstract (May 2007), four such high resolution DTMs are available for download via the HRSCview data product pages (for images from orbits 0572, 0905, 1004, and 2039).

Colour discrimination, colour naming and colour preferences among individuals with Alzheimer's disease.

PubMed

Wijk, H; Berg, S; Sivik, L; Steen, B

1999-12-01

To study the ability of colour naming, colour discrimination and colour preference in Alzheimer's disease (AD). Descriptive, consecutive sample. Fifty subjects >65 years with AD. Testing colour discrimination, colour naming and colour preferences. Ability to detect colour differences in the yellow, red, blue and green areas, ability to assign a name to 22 colour samples, ability to rank seven colours in order of preference. Discrimination ability was significantly better in the yellow and red area and for lightness variations. Cognitive decline had a significant impact on naming mixed colours and using elaborate colour names. Severity of dementia did not affect the preference rank order of colours. Ability to discriminate is affected in AD, with most errors in the blue and green area. Naming colours shows a cognitive decline. Preferences for colour are stable despite the disease. Copyright 1999 John Wiley & Sons, Ltd.

A colour image reproduction framework for 3D colour printing

NASA Astrophysics Data System (ADS)

Xiao, Kaida; Sohiab, Ali; Sun, Pei-li; Yates, Julian M.; Li, Changjun; Wuerger, Sophie

2016-10-01

In this paper, the current technologies in full colour 3D printing technology were introduced. A framework of colour image reproduction process for 3D colour printing is proposed. A special focus was put on colour management for 3D printed objects. Two approaches, colorimetric colour reproduction and spectral based colour reproduction are proposed in order to faithfully reproduce colours in 3D objects. Two key studies, colour reproduction for soft tissue prostheses and colour uniformity correction across different orientations are described subsequently. Results are clear shown that applying proposed colour image reproduction framework, performance of colour reproduction can be significantly enhanced. With post colour corrections, a further improvement in colour process are achieved for 3D printed objects.

The colour of a football outfit affects visibility and team success.

PubMed

Olde Rikkert, Joris; Haes, Vincent De; Barsingerhorn, Annemiek D; Theelen, Thomas; Olde Rikkert, Marcel G M

2015-01-01

We investigated the impact of the colour of football outfits on localising football players and on the results of football matches. Two studies were conducted: an experimental study examining the effects of outfit colour on the assessment of the positions of computer-animated football players in a video set-up (study 1) and a retrospective study on professional football clubs' performances dependent on their outfit colours (study 2). The studies were conducted with 18 human volunteers aged 15-18 years (study 1) and league results from 10 professional European football teams over 17 years (1995-2013) (study 2). We analysed the number of correct assessments of the positions of virtual football players with different outfit colours (study 1) and analysed the relationship between match results and outfits' colours (study 2). Study 1 showed that the position of players wearing white outfits was better assessed in 5.2% of the trials compared to players wearing green outfits (P = 0.007). Study 2 showed that Manchester City conceded less goals against in away games in highly visible kits (r = 0.62; P = 0.024), while Newcastle United conceded less goals and won more points while playing in kits associated with low visibility (r = 0.63; P = 0.007; r = 0.50; P = 0.040, respectively). We conclude that the colour of football outfits affects evaluations of football players' positions on the field, with white tricots resulting in the best location assessment. The outfit colour may indirectly influence football match results, warranting more attention to the home and away shirts by team managers and football scientists.

The Mendelian inheritance of rare flesh and shell colour variants in the black-lipped pearl oyster (Pinctada margaritifera).

PubMed

Ky, Chin-Long; Nakasai, Seiji; Pommier, Steve; Sham Koua, Manaarii; Devaux, Dominique

2016-10-01

Pinctada margaritifera is French Polynesia's most economically important aquaculture species. This pearl oyster has the specific ability to produce cultured pearls with a very wide range of colours, depending on the colour phenotypes of donor oysters used. Its aquaculture is still based on natural spat collection from wild stocks. We investigated three rare colour variants of P. margaritifera - orange flesh, and red and white shell colour phenotypes - in comparison with the wild-type black flesh and shell commonly found in this species. The study aimed to assess the geographic distribution and genetic basis of these colour variants. Colour frequencies were evaluated during transfer and graft processes of pearl oyster seed captured at collector stations. Among the collection locations studied, Mangareva Island showed the highest rate of the orange flesh phenotype, whereas Takaroa and Takume atolls had relatively high rates of red and white shell phenotypes respectively. Broodstocks were made of these rare colour variants, and crosses were performed to produce first- and second-generation progenies to investigate segregation. The results were consistent with Mendelian ratios and suggest a distinct model with no co-dominance: (i) a two-allele model for flesh trait, whereby the orange allele is recessive to the black fleshed type, and (ii) a three-allele model for shell trait, whereby the black wild-type allele is dominant to the red coloration, which is dominant to the white shell. Furthermore, the proposed model provides the basis for producing selected donor pearl oyster lines through hatchery propagation. © 2016 Stichting International Foundation for Animal Genetics.

Manakins can produce iridescent and bright feather colours without melanosomes.

PubMed

Igic, Branislav; D'Alba, Liliana; Shawkey, Matthew D

2016-06-15

Males of many species often use colourful and conspicuous ornaments to attract females. Among these, male manakins (family: Pipridae) provide classic examples of sexual selection favouring the evolution of bright and colourful plumage coloration. The highly iridescent feather colours of birds are most commonly produced by the periodic arrangement of melanin-containing organelles (melanosomes) within barbules. Melanin increases the saturation of iridescent colours seen from optimal viewing angles by absorbing back-scattered light; however, this may reduce the wide-angle brightness of these signals, contributing to a dark background appearance. We examined the nanostructure of four manakin species (Lepidothrix isidorei, L. iris, L. nattereri and L. coeruleocapilla) to identify how they produce their bright plumage colours. Feather barbs of all four species were characterized by dense and fibrous internal spongy matrices that likely increase scattering of light within the barb. The iridescent, yet pale or whitish colours of L. iris and L. nattereri feathers were produced not by periodically arranged melanosomes within barbules, but by periodic matrices of air and β-keratin within barbs. Lepidothrix iris crown feathers were able to produce a dazzling display of colours with small shifts in viewing geometry, likely because of a periodic nanostructure, a flattened barb morphology and disorder at a microstructural level. We hypothesize that iridescent plumage ornaments of male L. iris and L. nattereri are under selection to increase brightness or luminance across wide viewing angles, which may potentially increase their detectability by females during dynamic and fast-paced courtship displays in dim light environments. © 2016. Published by The Company of Biologists Ltd.

Use of Colour and Interactive Animation in Learning 3D Vectors

ERIC Educational Resources Information Center

Iskander, Wejdan; Curtis, Sharon

2005-01-01

This study investigated the effects of two computer-implemented techniques (colour and interactive animation) on learning 3D vectors. The participants were 43 female Saudi Arabian high school students. They were pre-tested on 3D vectors using a paper questionnaire that consisted of calculation and visualization types of questions. The students…

First CaSSIS Colour Images of Mars

NASA Astrophysics Data System (ADS)

Alfred, M.; Pommerol, A.; Thomas, N.; Cremonese, G.

2017-12-01

The Colour and Stereo Surface Imaging System (CaSSIS) on board ESA's Exomars Trace Gas Orbiter has acquired its first images of the surface of Mars on the 22nd and 26th of November, 2016. This commissioning campaign on the initial capture orbit was highly successful, allowing us to test the instrument, establish its performance and collect detailed images from the surface. Many of them have been publicly released within days following acquisition. These images and other commissioning data have demonstrated that the capabilities of the instrument are fully in-line with expectation. Although a colour image of Phobos produced from observations acquired on the 26th of November was rapidly released, the calibration and production of colour images from the surface of Mars proved to be more challenging. Having fixed technical issues, acquired and processed necessary in-flight calibration data, we have recently recalibrated the whole dataset, improving significantly the quality of the data and allowing us, for the first time, to produce high-quality colour images from the surface of Mars with CaSSIS data. The absolute calibration of the instrument is currently verified using stellar observations but the values of reflectivity obtained in each of the four colour channels for the surfaces of Mars and Phobos already show good consistency with other orbital data. The timing of CaSSIS acquisitions is very accurate and results in good colour matching, as already verified on-ground during the calibration campaign. The first few images acquired on the 22nd of November, shortly after TGO crossed the morning terminator, show unique views of the dusty terrains of the Tharsis region with solar incidence angle ranging between 60° and 80°. Comparison with images of the same areas acquired at later local times by other orbiters shows intriguing differences, related in particular to the brightness and colour of the floor of dust-filled craters that look bluer in the morning than in the afternoon. These observations and possible explanations of these changes in terms of diurnal volatile cycles will be presented and discussed, providing a glimpse into the future scientific activities permitted by CaSSIS once the nominal science phase begins in 2018.

High pressure applied to frozen ham at different process stages. 2. Effect on the sensory attributes and on the colour characteristics of dry-cured ham.

PubMed

Serra, X; Grèbol, N; Guàrdia, M D; Guerrero, L; Gou, P; Masoliver, P; Gassiot, M; Sárraga, C; Monfort, J M; Arnau, J

2007-01-01

This paper describes the effect of high pressure (400MPa and 600MPa) applied to frozen hams at early stages of the dry-cured ham process: green hams (GH) and hams at the end of the resting stage (ERS), on the appearance, some texture and flavour parameters and on the instrumental colour characteristics of dry-cured hams. Pressurized hams showed slightly lower visual colour intensity than the control ones. In general, pressurization did not have a significant effect on the flavour characteristics of the final product. The 600-MPa hams from the ERS process showed significantly lower crumbliness and higher fibrousness scores than the control and the 400-MPa hams. However, none of these differences were enough to affect the overall sensory quality of the hams negatively. Regarding instrumental colour characteristics (L(∗)a(∗)b(∗)), an increase in lightness was observed in the biceps femoris muscle from GH hams pressurized at 400MPa and 600MPa but not in the ERS hams.

Covert linear polarization signatures from brilliant white two-dimensional disordered wing structures of the phoenix damselfly.

PubMed

Nixon, M R; Orr, A G; Vukusic, P

2017-05-01

The damselfly Pseudolestes mirabilis reflects brilliant white on the ventral side of its hindwings and a copper-gold colour on the dorsal side. Unlike many previous investigations of odonate wings, in which colour appearances arise either from multilayer interference or from wing-membrane pigmentation, the whiteness on the wings of P. mirabilis results from light scattered by a specialized arrangement of flattened waxy fibres and the copper-gold colour is produced by pigment-based filtering of this light scatter. The waxy fibres responsible for this optical signature effectively form a structure that is disordered in two dimensions and this also gives rise to distinct optical linear polarization. It is a structure that provides a mechanism enabling P. mirabilis to display its bright wing colours efficiently for territorial signalling, both passively while perched, in which the sunlit copper-gold upperside is presented against a highly contrasting background of foliage, and actively in territorial contests in which the white underside is also presented. It also offers a template for biomimetic high-intensity broadband reflectors that have a pronounced polarization signature. © 2017 The Author(s).

High-contrast and fast electrochromic switching enabled by plasmonics

PubMed Central

Xu, Ting; Walter, Erich C.; Agrawal, Amit; Bohn, Christopher; Velmurugan, Jeyavel; Zhu, Wenqi; Lezec, Henri J.; Talin, A. Alec

2016-01-01

With vibrant colours and simple, room-temperature processing methods, electrochromic polymers have attracted attention as active materials for flexible, low-power-consuming devices. However, slow switching speeds in devices realized to date, as well as the complexity of having to combine several distinct polymers to achieve a full-colour gamut, have limited electrochromic materials to niche applications. Here we achieve fast, high-contrast electrochromic switching by significantly enhancing the interaction of light—propagating as deep-subwavelength-confined surface plasmon polaritons through arrays of metallic nanoslits, with an electrochromic polymer—present as an ultra-thin coating on the slit sidewalls. The switchable configuration retains the short temporal charge-diffusion characteristics of thin electrochromic films, while maintaining the high optical contrast associated with thicker electrochromic coatings. We further demonstrate that by controlling the pitch of the nanoslit arrays, it is possible to achieve a full-colour response with high contrast and fast switching speeds, while relying on just one electrochromic polymer. PMID:26814453

High-contrast and fast electrochromic switching enabled by plasmonics

DOE PAGES

Xu, Ting; Walter, Erich C.; Agrawal, Amit; ...

2016-01-27

With vibrant colours and simple, room-temperature processing methods, electrochromic polymers have attracted attention as active materials for flexible, low-power-consuming devices. However, slow switching speeds in devices realized to date, as well as the complexity of having to combine several distinct polymers to achieve a full-colour gamut, have limited electrochromic materials to niche applications. Here we achieve fast, high-contrast electrochromic switching by significantly enhancing the interaction of light—propagating as deep-subwavelength-confined surface plasmon polaritons through arrays of metallic nanoslits, with an electrochromic polymer—present as an ultra-thin coating on the slit sidewalls. The switchable configuration retains the short temporal charge-diffusion characteristics of thinmore » electrochromic films, while maintaining the high optical contrast associated with thicker electrochromic coatings. In conclusion, we further demonstrate that by controlling the pitch of the nanoslit arrays, it is possible to achieve a full-colour response with high contrast and fast switching speeds, while relying on just one electrochromic polymer.« less

Multi-particle three-dimensional coordinate estimation in real-time optical manipulation

NASA Astrophysics Data System (ADS)

Dam, J. S.; Perch-Nielsen, I.; Palima, D.; Gluckstad, J.

2009-11-01

We have previously shown how stereoscopic images can be obtained in our three-dimensional optical micromanipulation system [J. S. Dam et al, Opt. Express 16, 7244 (2008)]. Here, we present an extension and application of this principle to automatically gather the three-dimensional coordinates for all trapped particles with high tracking range and high reliability without requiring user calibration. Through deconvolving of the red, green, and blue colour planes to correct for bleeding between colour planes, we show that we can extend the system to also utilize green illumination, in addition to the blue and red. Applying the green colour as on-axis illumination yields redundant information for enhanced error correction, which is used to verify the gathered data, resulting in reliable coordinates as well as producing visually attractive images.

Adaptive camouflage: what can be learned from the wetting behaviour of the tropical flat bugs Dysodius lunatus and Dysodiusmagnus.

PubMed

Hischen, Florian; Reiswich, Vladislav; Kupsch, Desirée; De Mecquenem, Ninon; Riedel, Michael; Himmelsbach, Markus; Weth, Agnes; Heiss, Ernst; Armbruster, Oskar; Heitz, Johannes; Baumgartner, Werner

2017-08-15

The neotropical flat bug species Dysodius lunatus and Dysodius magnus show a fascinating camouflage principle, as their appearance renders the animal hardly visible on the bark of trees. However, when getting wet due to rain, bark changes its colour and gets darker. In order to keep the camouflage effect, it seems that some Dysodius species benefit from their ability to hold a water film on their cuticle and therefore change their optical properties when also wetted by water. This camouflage behaviour requires the insect to have a hydrophilic surface and passive surface structures which facilitate the liquid spreading. Here we show morphological and chemical characterisations of the surface, especially the cuticular waxes of D. magnus Scanning electron microscopy revealed that the animal is covered with pillar-like microstructures which, in combination with a surprising chemical hydrophilicity of the cuticle waxes, render the bug almost superhydrophilic: water spreads immediately across the surface. We could theoretically model this behaviour assuming the effect of hemi-wicking (a state in which a droplet sits on a rough surface, partwise imbibing the structure around).  Additionally the principle was abstracted and a laser-patterned polymer surface, mimicking the structure and contact angle of Dysodius wax, shows exactly the behaviour of the natural role model - immediate spreading of water and the formation of a thin continuous water film changing optical properties of the surface. © 2017. Published by The Company of Biologists Ltd.

Adaptive camouflage: what can be learned from the wetting behaviour of the tropical flat bugs Dysodius lunatus and Dysodius magnus

PubMed Central

Reiswich, Vladislav; Kupsch, Desirée; De Mecquenem, Ninon; Riedel, Michael; Himmelsbach, Markus; Weth, Agnes; Heiss, Ernst; Armbruster, Oskar; Heitz, Johannes; Baumgartner, Werner

2017-01-01

ABSTRACT The neotropical flat bug species Dysodius lunatus and Dysodius magnus show a fascinating camouflage principle, as their appearance renders the animal hardly visible on the bark of trees. However, when getting wet due to rain, bark changes its colour and gets darker. In order to keep the camouflage effect, it seems that some Dysodius species benefit from their ability to hold a water film on their cuticle and therefore change their optical properties when also wetted by water. This camouflage behaviour requires the insect to have a hydrophilic surface and passive surface structures which facilitate the liquid spreading. Here we show morphological and chemical characterisations of the surface, especially the cuticular waxes of D. magnus. Scanning electron microscopy revealed that the animal is covered with pillar-like microstructures which, in combination with a surprising chemical hydrophilicity of the cuticle waxes, render the bug almost superhydrophilic: water spreads immediately across the surface. We could theoretically model this behaviour assuming the effect of hemi-wicking (a state in which a droplet sits on a rough surface, partwise imbibing the structure around).  Additionally the principle was abstracted and a laser-patterned polymer surface, mimicking the structure and contact angle of Dysodius wax, shows exactly the behaviour of the natural role model – immediate spreading of water and the formation of a thin continuous water film changing optical properties of the surface. PMID:28811303

The colour preference control based on two-colour combinations

NASA Astrophysics Data System (ADS)

Hong, Ji Young; Kwak, Youngshin; Park, Du-Sik; Kim, Chang Yeong

2008-02-01

This paper proposes a framework of colour preference control to satisfy the consumer's colour related emotion. A colour harmony algorithm based on two-colour combinations is developed for displaying the images with several complementary colour pairs as the relationship of two-colour combination. The colours of pixels belonging to complementary colour areas in HSV colour space are shifted toward the target hue colours and there is no colour change for the other pixels. According to the developed technique, dynamic emotions by the proposed hue conversion can be improved and the controlled output image shows improved colour emotions in the preference of the human viewer. The psychophysical experiments are conducted to investigate the optimal model parameters to produce the most pleasant image to the users in the respect of colour emotions.

Interactions between colour and synaesthetic colour: an effect of simultaneous colour contrast on synaesthetic colours.

PubMed

Nijboer, Tanja C W; Gebuis, Titia; te Pas, Susan F; van der Smagt, Maarten J

2011-01-01

We investigated whether simultaneous colour contrast affects the synaesthetic colour experience and normal colour percept in a similar manner. We simultaneously presented a target stimulus (i.e. grapheme) and a reference stimulus (i.e. hash). Either the grapheme or the hash was presented on a saturated background of the same or opposite colour category as the synaesthetic colour and the other stimulus on a grey background. In both conditions, grapheme-colour synaesthetes were asked to colour the hash in a colour similar to the synaesthetic colour of the grapheme. Controls that were pair-matched to the synaesthetes performed the same experiment, but for them, the grapheme was presented in the colour induced by the grapheme in synaesthetes. When graphemes were presented on a grey and the hash on a coloured background, a traditional simultaneous colour-contrast effect was found for controls as well as synaesthetes. When graphemes were presented on colour and the hash on grey, the controls again showed a traditional simultaneous colour-contrast effect, whereas the synaesthetes showed the opposite effect. Our results show that synaesthetic colour experiences differ from normal colour perception; both are susceptible to different surrounding colours, but not in a comparable manner. Copyright © 2010 Elsevier Ltd. All rights reserved.

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.

Characterisation of the n-colour printing process using the spot colour overprint model.

PubMed

Deshpande, Kiran; Green, Phil; Pointer, Michael R

2014-12-29

This paper is aimed at reproducing the solid spot colours using the n-colour separation. A simplified numerical method, called as the spot colour overprint (SCOP) model, was used for characterising the n-colour printing process. This model was originally developed for estimating the spot colour overprints. It was extended to be used as a generic forward characterisation model for the n-colour printing process. The inverse printer model based on the look-up table was implemented to obtain the colour separation for n-colour printing process. Finally the real-world spot colours were reproduced using 7-colour separation on lithographic offset printing process. The colours printed with 7 inks were compared against the original spot colours to evaluate the accuracy. The results show good accuracy with the mean CIEDE2000 value between the target colours and the printed colours of 2.06. The proposed method can be used successfully to reproduce the spot colours, which can potentially save significant time and cost in the printing and packaging industry.

The colour of an avifauna: A quantitative analysis of the colour of Australian birds

PubMed Central

Delhey, Kaspar

2015-01-01

Animal coloration is a poorly-understood aspect of phenotypic variability. Here I expand initial studies of the colour gamut of birds by providing the first quantitative description of the colour variation of an entire avifauna: Australian landbirds (555 species). The colour of Australian birds occupies a small fraction (19%) of the entire possible colour space and colour variation is extremely uneven. Most colours are unsaturated, concentrated in the centre of colour space and based on the deposition of melanins. Other mechanisms of colour production are less common but account for larger portions of colour space and for most saturated colours. Male colours occupy 45–25% more colour space than female colours, indicating that sexual dichromatism translates into a broader range of male colours. Male-exclusive colours are often saturated, at the edge of chromatic space, and have most likely evolved for signalling. While most clades of birds occupy expected or lower-than-expected colour volumes, parrots and cockatoos (Order Psittaciformes) occupy a much larger volume than expected. This uneven distribution of colour variation across mechanisms of colour production, sexes and clades is probably shared by avifaunas in other parts of the world, but this remains to be tested with comparable data. PMID:26679370

Connecting massive galaxies to dark matter haloes in BOSS - I. Is galaxy colour a stochastic process in high-mass haloes?

NASA Astrophysics Data System (ADS)

Saito, Shun; Leauthaud, Alexie; Hearin, Andrew P.; Bundy, Kevin; Zentner, Andrew R.; Behroozi, Peter S.; Reid, Beth A.; Sinha, Manodeep; Coupon, Jean; Tinker, Jeremy L.; White, Martin; Schneider, Donald P.

2016-08-01

We use subhalo abundance matching (SHAM) to model the stellar mass function (SMF) and clustering of the Baryon Oscillation Spectroscopic Survey (BOSS) `CMASS' sample at z ˜ 0.5. We introduce a novel method which accounts for the stellar mass incompleteness of CMASS as a function of redshift, and produce CMASS mock catalogues which include selection effects, reproduce the overall SMF, the projected two-point correlation function wp, the CMASS dn/dz, and are made publicly available. We study the effects of assembly bias above collapse mass in the context of `age matching' and show that these effects are markedly different compared to the ones explored by Hearin et al. at lower stellar masses. We construct two models, one in which galaxy colour is stochastic (`AbM' model) as well as a model which contains assembly bias effects (`AgM' model). By confronting the redshift dependent clustering of CMASS with the predictions from our model, we argue that that galaxy colours are not a stochastic process in high-mass haloes. Our results suggest that the colours of galaxies in high-mass haloes are determined by other halo properties besides halo peak velocity and that assembly bias effects play an important role in determining the clustering properties of this sample.

Characteristic analysis and simulation for polysilicon comb micro-accelerometer

NASA Astrophysics Data System (ADS)

Liu, Fengli; Hao, Yongping

2008-10-01

High force update rate is a key factor for achieving high performance haptic rendering, which imposes a stringent real time requirement upon the execution environment of the haptic system. This requirement confines the haptic system to simplified environment for reducing the computation cost of haptic rendering algorithms. In this paper, we present a novel "hyper-threading" architecture consisting of several threads for haptic rendering. The high force update rate is achieved with relatively large computation time interval for each haptic loop. The proposed method was testified and proved to be effective with experiments on virtual wall prototype haptic system via Delta Haptic Device.

Independent effects of colour on object identification and memory.

PubMed

Lloyd-Jones, Toby J; Nakabayashi, Kazuyo

2009-02-01

We examined the effects of colour on object identification and memory using a study-test priming procedure with a coloured-object decision task at test (i.e., deciding whether an object is correctly coloured). Objects were selected to have a single associated colour and were either correctly or incorrectly coloured. In addition, object shape and colour were either spatially integrated (i.e., colour fell on the object surface) or spatially separated (i.e., colour formed the background to the object). Transforming the colour of an object from study to test (e.g., from a yellow banana to a purple banana) reduced priming of response times, as compared to when the object was untransformed. This utilization of colour information in object memory was not contingent upon colour falling on the object surface or whether the resulting configuration was of a correctly or incorrectly coloured object. In addition, we observed independent effects of colour on response times, whereby coloured-object decisions were more efficient for correctly than for incorrectly coloured objects but only when colour fell on the object surface. These findings provide evidence for two distinct mechanisms of shape-colour binding in object processing.

ADASY (Active Daylighting System)

NASA Astrophysics Data System (ADS)

Vázquez-Moliní, Daniel; González-Montes, Mario; Fernández-Balbuena, Antonio Á.; Bernabéu, Eusebio; García-Botella, Ángel; García-Rodríguez, Lucas; Pohl, Wilfried

2009-08-01

The main objective of ADASY (Active Daylighting System) work is to design a façade static daylighting system oriented to office applications, mainly. The goal of the project is to save energy by guiding daylight into a building for lighting purpose. With this approach we can reduce the electrical load for artificial lighting, completing it with sustainable energy. The collector of the system is integrated on a vertical façade and its distribution guide is always horizontal inside of the false ceiling. ADASY is designed with a specific patent pending caption system, a modular light-guide and light extractor luminaire system. Special care has been put on the final cost of the system and its building integration purpose. The current ADASY configuration is able to illuminate 40 m2 area with a 300lx-400lx level in the mid time work hours; furthermore it has a good enough spatial uniformity distribution and a controlled glare. The data presented in this study are the result of simulation models and have been confirmed by a physical scaled prototype. ADASY's main advantages over regular illumination systems are: -Low maintenance; it has not mobile pieces and therefore it lasts for a long time and require little attention once installed. - No energy consumption; solar light continue working even if there has been a power outage. - High quality of light: the colour rendering of light is very high - Psychological benefits: People working with daylight get less stress and more comfort, increasing productivity. - Health benefits

Novel quantitative pigmentation phenotyping enhances genetic association, epistasis, and prediction of human eye colour.

PubMed

Wollstein, Andreas; Walsh, Susan; Liu, Fan; Chakravarthy, Usha; Rahu, Mati; Seland, Johan H; Soubrane, Gisèle; Tomazzoli, Laura; Topouzis, Fotis; Vingerling, Johannes R; Vioque, Jesus; Böhringer, Stefan; Fletcher, Astrid E; Kayser, Manfred

2017-02-27

Success of genetic association and the prediction of phenotypic traits from DNA are known to depend on the accuracy of phenotype characterization, amongst other parameters. To overcome limitations in the characterization of human iris pigmentation, we introduce a fully automated approach that specifies the areal proportions proposed to represent differing pigmentation types, such as pheomelanin, eumelanin, and non-pigmented areas within the iris. We demonstrate the utility of this approach using high-resolution digital eye imagery and genotype data from 12 selected SNPs from over 3000 European samples of seven populations that are part of the EUREYE study. In comparison to previous quantification approaches, (1) we achieved an overall improvement in eye colour phenotyping, which provides a better separation of manually defined eye colour categories. (2) Single nucleotide polymorphisms (SNPs) known to be involved in human eye colour variation showed stronger associations with our approach. (3) We found new and confirmed previously noted SNP-SNP interactions. (4) We increased SNP-based prediction accuracy of quantitative eye colour. Our findings exemplify that precise quantification using the perceived biological basis of pigmentation leads to enhanced genetic association and prediction of eye colour. We expect our approach to deliver new pigmentation genes when applied to genome-wide association testing.

Discriminant Analysis of Defective and Non-Defective Field Pea (Pisum sativum L.) into Broad Market Grades Based on Digital Image Features.

PubMed

McDonald, Linda S; Panozzo, Joseph F; Salisbury, Phillip A; Ford, Rebecca

2016-01-01

Field peas (Pisum sativum L.) are generally traded based on seed appearance, which subjectively defines broad market-grades. In this study, we developed an objective Linear Discriminant Analysis (LDA) model to classify market grades of field peas based on seed colour, shape and size traits extracted from digital images. Seeds were imaged in a high-throughput system consisting of a camera and laser positioned over a conveyor belt. Six colour intensity digital images were captured (under 405, 470, 530, 590, 660 and 850nm light) for each seed, and surface height was measured at each pixel by laser. Colour, shape and size traits were compiled across all seed in each sample to determine the median trait values. Defective and non-defective seed samples were used to calibrate and validate the model. Colour components were sufficient to correctly classify all non-defective seed samples into correct market grades. Defective samples required a combination of colour, shape and size traits to achieve 87% and 77% accuracy in market grade classification of calibration and validation sample-sets respectively. Following these results, we used the same colour, shape and size traits to develop an LDA model which correctly classified over 97% of all validation samples as defective or non-defective.

Pterin pigment granules are responsible for both broadband light scattering and wavelength selective absorption in the wing scales of pierid butterflies

PubMed Central

Morehouse, Nathan I; Vukusic, Peter; Rutowski, Ron

2006-01-01

A small but growing literature indicates that many animal colours are produced by combinations of structural and pigmentary mechanisms. We investigated one such complex colour phenotype: the highly chromatic wing colours of pierid butterflies including oranges, yellows and patterns which appear white to the human eye, but strongly absorb the ultraviolet (UV) wavelengths visible to butterflies. Pierids produce these bright colours using wing scales that contain collections of minute granules. However, to date, no work has directly characterized the molecular composition or optical properties of these granules. We present results that indicate these granules contain pterin pigments. We also find that pterin granules increase light reflection from single wing scales, such that wing scales containing denser granule arrays reflect more light than those with less dense granule collections. As male wing scales contain more pterin granules than those of females, the sexual dichromatism found in many pierid species can be explained by differences in wing scale pterin deposition. Additionally, the colour pattern elements produced by these pterins are known to be important during mating interactions in a number of pierid species. Therefore, we discuss the potential relevance of our results within the framework of sexual selection and colour signal evolution. PMID:17164199

Floral colours in a world without birds and bees: the plants of Macquarie Island.

PubMed

Shrestha, M; Lunau, K; Dorin, A; Schulze, B; Bischoff, M; Burd, M; Dyer, A G

2016-09-01

We studied biotically pollinated angiosperms on Macquarie Island, a remote site in the Southern Ocean with a predominately or exclusively dipteran pollinator fauna, in an effort to understand how flower colour affects community assembly. We compared a distinctive group of cream-green Macquarie Island flowers to the flora of likely source pools of immigrants and to a continental flora from a high latitude in the northern hemisphere. We used both dipteran and hymenopteran colour models and phylogenetically informed analyses to explore the chromatic component of community assembly. The species with cream-green flowers are very restricted in colour space models of both fly vision and bee vision and represent a distinct group that plays a very minor role in other communities. It is unlikely that such a community could form through random immigration from continental source pools. Our findings suggest that fly pollination has imposed a strong ecological filter on Macquarie Island, favouring floral colours that are rare in continental floras. This is one of the strongest demonstrations that plant-pollinator interactions play an important role in plant community assembly. Future work exploring colour choices by dipteran flower visitors would be valuable. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

Automatic CDR Estimation for Early Glaucoma Diagnosis

PubMed Central

Sarmiento, A.; Sanchez-Morillo, D.; Jiménez, S.; Alemany, P.

2017-01-01

Glaucoma is a degenerative disease that constitutes the second cause of blindness in developed countries. Although it cannot be cured, its progression can be prevented through early diagnosis. In this paper, we propose a new algorithm for automatic glaucoma diagnosis based on retinal colour images. We focus on capturing the inherent colour changes of optic disc (OD) and cup borders by computing several colour derivatives in CIE L∗a∗b∗ colour space with CIE94 colour distance. In addition, we consider spatial information retaining these colour derivatives and the original CIE L∗a∗b∗ values of the pixel and adding other characteristics such as its distance to the OD centre. The proposed strategy is robust due to a simple structure that does not need neither initial segmentation nor removal of the vascular tree or detection of vessel bends. The method has been extensively validated with two datasets (one public and one private), each one comprising 60 images of high variability of appearances. Achieved class-wise-averaged accuracy of 95.02% and 81.19% demonstrates that this automated approach could support physicians in the diagnosis of glaucoma in its early stage, and therefore, it could be seen as an opportunity for developing low-cost solutions for mass screening programs. PMID:29279773

Discriminant Analysis of Defective and Non-Defective Field Pea (Pisum sativum L.) into Broad Market Grades Based on Digital Image Features

PubMed Central

McDonald, Linda S.; Panozzo, Joseph F.; Salisbury, Phillip A.; Ford, Rebecca

2016-01-01

Field peas (Pisum sativum L.) are generally traded based on seed appearance, which subjectively defines broad market-grades. In this study, we developed an objective Linear Discriminant Analysis (LDA) model to classify market grades of field peas based on seed colour, shape and size traits extracted from digital images. Seeds were imaged in a high-throughput system consisting of a camera and laser positioned over a conveyor belt. Six colour intensity digital images were captured (under 405, 470, 530, 590, 660 and 850nm light) for each seed, and surface height was measured at each pixel by laser. Colour, shape and size traits were compiled across all seed in each sample to determine the median trait values. Defective and non-defective seed samples were used to calibrate and validate the model. Colour components were sufficient to correctly classify all non-defective seed samples into correct market grades. Defective samples required a combination of colour, shape and size traits to achieve 87% and 77% accuracy in market grade classification of calibration and validation sample-sets respectively. Following these results, we used the same colour, shape and size traits to develop an LDA model which correctly classified over 97% of all validation samples as defective or non-defective. PMID:27176469

Novel quantitative pigmentation phenotyping enhances genetic association, epistasis, and prediction of human eye colour

PubMed Central

Wollstein, Andreas; Walsh, Susan; Liu, Fan; Chakravarthy, Usha; Rahu, Mati; Seland, Johan H.; Soubrane, Gisèle; Tomazzoli, Laura; Topouzis, Fotis; Vingerling, Johannes R.; Vioque, Jesus; Böhringer, Stefan; Fletcher, Astrid E.; Kayser, Manfred

2017-01-01

Success of genetic association and the prediction of phenotypic traits from DNA are known to depend on the accuracy of phenotype characterization, amongst other parameters. To overcome limitations in the characterization of human iris pigmentation, we introduce a fully automated approach that specifies the areal proportions proposed to represent differing pigmentation types, such as pheomelanin, eumelanin, and non-pigmented areas within the iris. We demonstrate the utility of this approach using high-resolution digital eye imagery and genotype data from 12 selected SNPs from over 3000 European samples of seven populations that are part of the EUREYE study. In comparison to previous quantification approaches, (1) we achieved an overall improvement in eye colour phenotyping, which provides a better separation of manually defined eye colour categories. (2) Single nucleotide polymorphisms (SNPs) known to be involved in human eye colour variation showed stronger associations with our approach. (3) We found new and confirmed previously noted SNP-SNP interactions. (4) We increased SNP-based prediction accuracy of quantitative eye colour. Our findings exemplify that precise quantification using the perceived biological basis of pigmentation leads to enhanced genetic association and prediction of eye colour. We expect our approach to deliver new pigmentation genes when applied to genome-wide association testing. PMID:28240252

Visual awareness of objects and their colour.

PubMed

Pilling, Michael; Gellatly, Angus

2011-10-01

At any given moment, our awareness of what we 'see' before us seems to be rather limited. If, for instance, a display containing multiple objects is shown (red or green disks), when one object is suddenly covered at random, observers are often little better than chance in reporting about its colour (Wolfe, Reinecke, & Brawn, Visual Cognition, 14, 749-780, 2006). We tested whether, when object attributes (such as colour) are unknown, observers still retain any knowledge of the presence of that object at a display location. Experiments 1-3 involved a task requiring two-alternative (yes/no) responses about the presence or absence of a colour-defined object at a probed location. On this task, if participants knew about the presence of an object at a location, responses indicated that they also knew about its colour. A fourth experiment presented the same displays but required a three-alternative response. This task did result in a data pattern consistent with participants' knowing more about the locations of objects within a display than about their individual colours. However, this location advantage, while highly significant, was rather small in magnitude. Results are compared with those of Huang (Journal of Vision, 10(10, Art. 24), 1-17, 2010), who also reported an advantage for object locations, but under quite different task conditions.

Decolourization of remazol black-5 textile dyes using moving bed bio-film reactor

NASA Astrophysics Data System (ADS)

Pratiwi, R.; Notodarmojo, S.; Helmy, Q.

2018-01-01

The desizing and dyeing processes in the textile industries produces wastewaster containing high concentration of organic matter and colour, so it needs treatment before released to environment. In this research, removal of azo dye (Remazol Black 5/RB 5) and organic as COD was performed using Moving Bed Biofilm Reactor (MBBR). MBBR is biological treatment process with attached growth media system that can increase removal of organic matter in textile wastewater. The effectiveness of ozonation as pre-treatment process to increase the removal efficiency in MBBR was studied. The results showed that in MBBR batch system with detention time of 1 hour, pre-treatment with ozonation prior to MBBR process able to increase the colour removal efficiency of up to 86.74%. While on the reactor without ozone pre-treatment, the colour removal efficiency of up to 68.6% was achieved. From the continuous reactor experiments found that both colour and COD removal efficiency depends on time detention of RB-5 dyes in the system. The higher of detention time, the higher of colour and COD removal efficiency. It was found that optimum removal of colour and COD was achieved in 24 hour detention time with its efficiency of 96.9% and 89.13%, respectively.

Reliability of the Raven Coloured Progressive Matrices for Anglo and for Mexican-American Children.

ERIC Educational Resources Information Center

Valencia, Richard R.

1984-01-01

Investigated the internal consistency reliability estimates of the Raven Coloured Progressive Matrices (CPM) for 96 Anglo and Mexican American third-grade boys from low socioeconomic status background. The results showed that the reliability estimates of the CPM for the two ethnic groups were acceptably high and extremely similar in magnitude.…

Who You Callin' White?! A Critical Counter-Story on Colouring White Identity

ERIC Educational Resources Information Center

Matias, Cheryl E.

2013-01-01

This action research, which utilizes critical race theory's counter-storytelling, analyses a process of debunking White students' epistemology of ignorance in a history course at an urban public high school. After piloting a raced curriculum that deliberately re-centers marginalized counter-stories of students of colour, I document its…

Male bumblebees, Bombus terrestris, perform equally well as workers in a serial colour-learning task

PubMed Central

Wolf, Stephan; Chittka, Lars

2016-01-01

The learning capacities of males and females may differ with sex-specific behavioural requirements. Bumblebees provide a useful model system to explore how different lifestyles are reflected in learning abilities, because their (female but sterile) workers and males engage in fundamentally different behaviour routines. Bumblebee males, like workers, embark on active flower foraging but in contrast to workers they have to trade off their feeding with mate search, potentially affecting their abilities to learn and utilize floral cues efficiently during foraging. We used a serial colour-learning task with freely flying males and workers to compare their ability to flexibly learn visual floral cues with reward in a foraging scenario that changed over time. Male bumblebees did not differ from workers in both their learning speed and their ability to overcome previously acquired associations, when these ceased to predict reward. In all foraging tasks we found a significant improvement in choice accuracy in both sexes over the course of the training. In both sexes, the characteristics of the foraging performance depended largely on the colour difference of the two presented feeder types. Large colour distances entailed fast and reliable learning of the rewarding feeders whereas choice accuracy on highly similar colours improved significantly more slowly. Conversely, switching from a learned feeder type to a novel one was fastest for similar feeder colours and slow for highly different ones. Overall, we show that behavioural sex dimorphism in bumblebees did not affect their learning abilities beyond the mating context. We discuss the possible drivers and limitations shaping the foraging abilities of males and workers and implications for pollination ecology. We also suggest stingless male bumblebees as an advantageous alternative model system for the study of pollinator cognition. PMID:26877542

Real-time volume rendering of digital medical images on an iOS device

NASA Astrophysics Data System (ADS)

Noon, Christian; Holub, Joseph; Winer, Eliot

2013-03-01

Performing high quality 3D visualizations on mobile devices, while tantalizingly close in many areas, is still a quite difficult task. This is especially true for 3D volume rendering of digital medical images. Allowing this would empower medical personnel a powerful tool to diagnose and treat patients and train the next generation of physicians. This research focuses on performing real time volume rendering of digital medical images on iOS devices using custom developed GPU shaders for orthogonal texture slicing. An interactive volume renderer was designed and developed with several new features including dynamic modification of render resolutions, an incremental render loop, a shader-based clipping algorithm to support OpenGL ES 2.0, and an internal backface culling algorithm for properly sorting rendered geometry with alpha blending. The application was developed using several application programming interfaces (APIs) such as OpenSceneGraph (OSG) as the primary graphics renderer coupled with iOS Cocoa Touch for user interaction, and DCMTK for DICOM I/O. The developed application rendered volume datasets over 450 slices up to 50-60 frames per second, depending on the specific model of the iOS device. All rendering is done locally on the device so no Internet connection is required.

Floral scent emitted by white and coloured morphs in orchids.

PubMed

Dormont, L; Delle-Vedove, R; Bessière, J-M; Schatz, B

2014-04-01

Polymorphism of floral signals, such as colour and odour, is widespread in flowering plants and often considered to be adaptive, reflecting various pollinator preferences for particular floral traits. Several authors have recently hypothesized that particular associations exist between floral colour and scent, which would result from shared biochemistry between these two floral traits. In this study, we compared the chemical composition of floral volatiles emitted by white- and purple-flowered morphs of three different orchid species, including two food-deceptive species (Orchis mascula and Orchis simia) and a food-rewarding species (Anacamptis coriophora fragrans). We found clear interspecific differences in floral odours. As expected from their pollination strategy, the two deceptive orchids showed high inter-individual variation of floral volatiles, whereas the food-rewarding A. c. fragrans showed low variation of floral scent. Floral volatiles did not differ overall between white- and coloured-flowered morphs in O. mascula and A. c. fragrans, while O. simia exhibited different volatile profiles between the two colour morphs. However, a detailed analysis restricted to benzenoid compounds (which are associated with the production of floral anthocyanin pigments) showed that white inflorescences emitted more volatiles of the shikimic pathway than coloured ones, both for O. mascula and O. simia. These results are consistent with the current hypothesis that shared biochemistry creates pleiotropic links between floral colour and scent. Whether intraspecific variation of floral signals actually affects pollinator attraction and influences the reproductive success of these orchids remains to be determined. Copyright © 2014 Elsevier Ltd. All rights reserved.

Real-time photorealistic stereoscopic rendering of fire

NASA Astrophysics Data System (ADS)

Rose, Benjamin M.; McAllister, David F.

2007-02-01

We propose a method for real-time photorealistic stereo rendering of the natural phenomenon of fire. Applications include the use of virtual reality in fire fighting, military training, and entertainment. Rendering fire in real-time presents a challenge because of the transparency and non-static fluid-like behavior of fire. It is well known that, in general, methods that are effective for monoscopic rendering are not necessarily easily extended to stereo rendering because monoscopic methods often do not provide the depth information necessary to produce the parallax required for binocular disparity in stereoscopic rendering. We investigate the existing techniques used for monoscopic rendering of fire and discuss their suitability for extension to real-time stereo rendering. Methods include the use of precomputed textures, dynamic generation of textures, and rendering models resulting from the approximation of solutions of fluid dynamics equations through the use of ray-tracing algorithms. We have found that in order to attain real-time frame rates, our method based on billboarding is effective. Slicing is used to simulate depth. Texture mapping or 2D images are mapped onto polygons and alpha blending is used to treat transparency. We can use video recordings or prerendered high-quality images of fire as textures to attain photorealistic stereo.

A curved surface micro-moiré method and its application in evaluating curved surface residual stress

NASA Astrophysics Data System (ADS)

Zhang, Hongye; Wu, Chenlong; Liu, Zhanwei; Xie, Huimin

2014-09-01

The moiré method is typically applied to the measurement of deformations of a flat surface while, for a curved surface, this method is rarely used other than for projection moiré or moiré interferometry. Here, a novel colour charge-coupled device (CCD) micro-moiré method has been developed, based on which a curved surface micro-moiré (CSMM) method is proposed with a colour CCD and optical microscope (OM). In the CSMM method, no additional reference grating is needed as a Bayer colour filter array (CFA) installed on the OM in front of the colour CCD image sensor performs this role. Micro-moiré fringes with high contrast are directly observed with the OM through the Bayer CFA under the special condition of observing a curved specimen grating. The principle of the CSMM method based on a colour CCD micro-moiré method and its application range and error analysis are all described in detail. In an experiment, the curved surface residual stress near a welded seam on a stainless steel tube was investigated using the CSMM method.

Treatment of melanoidin wastewater by anaerobic digestion and coagulation.

PubMed

Arimi, Milton M; Zhang, Yongjun; Götz, Gesine; Geißen, Sven-Uwe

2015-01-01

Melanoidins are dark-coloured recalcitrant pollutants found in many industrial wastewaters including coffee-manufacturing effluent, molasses distillery wastewater (MDWW) and other wastewater with molasses as the raw material. The wastewaters are mostly treated with anaerobic digestion after some dilution to minimize the inhibition effect. However, the dark colour and recalcitrant dissolved organic carbon (DOC) mainly caused by melanoidin are not effectively removed. The aim of this study was to investigate the removal of colour and remnant DOC by different coagulants from anaerobically digested MDWW. From the six coagulants tested, ferric chloride had the highest melanoidin (48%), colour (92.7%) and DOC (63.3%) removal at pH 5 and a dosage of 1.6 g/l. Both polymer and inorganic salt coagulants tested had optimal colour, melanoidin and DOC removal at acidic pH. The molecular size distribution of synthetic melanoidins by liquid chromatography-organic carbon detection indicated a preferential removal of high-molecular-weight melanoidins over low weight melanoidins by the coagulation. Further studies should focus on how to improve biodegradability of the treated effluent for it to be reused as dilution water for anaerobic digestion.

Determination of diffusion coefficients of biocides on their passage through organic resin-based renders.

PubMed

Styszko, Katarzyna; Kupiec, Krzysztof

2016-10-01

In this study the diffusion coefficients of isoproturon, diuron and cybutryn in acrylate and silicone resin-based renders were determined. The diffusion coefficients were determined using measuring concentrations of biocides in the liquid phase after being in contact with renders for specific time intervals. The mathematical solution of the transient diffusion equation for an infinite plate contacted on one side with a limited volume of water was used to calculate the diffusion coefficient. The diffusion coefficients through the acrylate render were 8.10·10(-9) m(2) s(-1) for isoproturon, 1.96·10(-9) m(2) s(-1) for diuron and 1.53·10(-9) m(2) s(-1) for cybutryn. The results for the silicone render were lower by one order of magnitude. The compounds with a high diffusion coefficient for one polymer had likewise high values for the other polymer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Conventional freezing plus high pressure-low temperature treatment: Physical properties, microbial quality and storage stability of beef meat.

PubMed

Fernández, Pedro P; Sanz, Pedro D; Molina-García, Antonio D; Otero, Laura; Guignon, Bérengère; Vaudagna, Sergio R

2007-12-01

Meat high-hydrostatic pressure treatment causes severe decolouration, preventing its commercialisation due to consumer rejection. Novel procedures involving product freezing plus low-temperature pressure processing are here investigated. Room temperature (20°C) pressurisation (650MPa/10min) and air blast freezing (-30°C) are compared to air blast freezing plus high pressure at subzero temperature (-35°C) in terms of drip loss, expressible moisture, shear force, colour, microbial quality and storage stability of fresh and salt-added beef samples (Longissimus dorsi muscle). The latter treatment induced solid water transitions among ice phases. Fresh beef high pressure treatment (650MPa/20°C/10min) increased significantly expressible moisture while it decreased in pressurised (650MPa/-35°C/10min) frozen beef. Salt addition reduced high pressure-induced water loss. Treatments studied did not change fresh or salt-added samples shear force. Frozen beef pressurised at low temperature showed L, a and b values after thawing close to fresh samples. However, these samples in frozen state, presented chromatic parameters similar to unfrozen beef pressurised at room temperature. Apparently, freezing protects meat against pressure colour deterioration, fresh colour being recovered after thawing. High pressure processing (20°C or -35°C) was very effective reducing aerobic total (2-log(10) cycles) and lactic acid bacteria counts (2.4-log(10) cycles), in fresh and salt-added samples. Frozen+pressurised beef stored at -18°C during 45 days recovered its original colour after thawing, similarly to just-treated samples while their counts remain below detection limits during storage.

Development of an algorithm for improving quality and information processing capacity of MathSpeak synthetic speech renderings.

PubMed

Isaacson, M D; Srinivasan, S; Lloyd, L L

2010-01-01

MathSpeak is a set of rules for non speaking of mathematical expressions. These rules have been incorporated into a computerised module that translates printed mathematics into the non-ambiguous MathSpeak form for synthetic speech rendering. Differences between individual utterances produced with the translator module are difficult to discern because of insufficient pausing between utterances; hence, the purpose of this study was to develop an algorithm for improving the synthetic speech rendering of MathSpeak. To improve synthetic speech renderings, an algorithm for inserting pauses was developed based upon recordings of middle and high school math teachers speaking mathematic expressions. Efficacy testing of this algorithm was conducted with college students without disabilities and high school/college students with visual impairments. Parameters measured included reception accuracy, short-term memory retention, MathSpeak processing capacity and various rankings concerning the quality of synthetic speech renderings. All parameters measured showed statistically significant improvements when the algorithm was used. The algorithm improves the quality and information processing capacity of synthetic speech renderings of MathSpeak. This increases the capacity of individuals with print disabilities to perform mathematical activities and to successfully fulfill science, technology, engineering and mathematics academic and career objectives.

Method to optimize patch size based on spatial frequency response in image rendering of the light field

NASA Astrophysics Data System (ADS)

Zhang, Wei; Wang, Yanan; Zhu, Zhenhao; Su, Jinhui

2018-05-01

A focused plenoptic camera can effectively transform angular and spatial information to yield a refocused rendered image with high resolution. However, choosing a proper patch size poses a significant problem for the image-rendering algorithm. By using a spatial frequency response measurement, a method to obtain a suitable patch size is presented. By evaluating the spatial frequency response curves, the optimized patch size can be obtained quickly and easily. Moreover, the range of depth over which images can be rendered without artifacts can be estimated. Experiments show that the results of the image rendered based on frequency response measurement are in accordance with the theoretical calculation, which indicates that this is an effective way to determine the patch size. This study may provide support to light-field image rendering.

Does Colour Preference Have a Role in Colour Term Acquisition?

ERIC Educational Resources Information Center

Pitchford, Nicola J.; Davis, Emma E.; Scerif, Gaia

2009-01-01

A developmental association exists between colour preference and emerging colour term acquisition in young children. Colour preference might influence colour term acquisition by directing attention towards or away from a particular colour, making it more or less memorable. To investigate the role that colour preference may have in the acquisition…

The role of colour in implicit and explicit memory performance.

PubMed

Vernon, David; Lloyd-Jones, Toby J

2003-07-01

We present two experiments that examine the effects of colour transformation between study and test (from black and white to colour and vice versa, of from incorrectly coloured to correctly coloured and vice versa) on implicit and explicit measures of memory for diagnostically coloured natural objects (e.g., yellow banana). For naming and coloured-object decision (i.e., deciding whether an object is correctly coloured), there were shorter response times to correctly coloured-objects than to black-and-white and incorrectly coloured-objects. Repetition priming was equivalent for the different stimulus types. Colour transformation did not influence priming of picture naming, but for coloured-object decision priming was evident only for objects remaining the same from study to test. This was the case for both naming and coloured-object decision as study tasks. When participants were asked to consciously recognize objects that they had named or made coloured-object decisions to previously, whilst ignoring their colour, colour transformation reduced recognition efficiency. We discuss these results in terms of the flexibility of object representations that mediate priming and recognition.

Confounding environmental colour and distribution shape leads to underestimation of population extinction risk.

PubMed

Fowler, Mike S; Ruokolainen, Lasse

2013-01-01

The colour of environmental variability influences the size of population fluctuations when filtered through density dependent dynamics, driving extinction risk through dynamical resonance. Slow fluctuations (low frequencies) dominate in red environments, rapid fluctuations (high frequencies) in blue environments and white environments are purely random (no frequencies dominate). Two methods are commonly employed to generate the coloured spatial and/or temporal stochastic (environmental) series used in combination with population (dynamical feedback) models: autoregressive [AR(1)] and sinusoidal (1/f) models. We show that changing environmental colour from white to red with 1/f models, and from white to red or blue with AR(1) models, generates coloured environmental series that are not normally distributed at finite time-scales, potentially confounding comparison with normally distributed white noise models. Increasing variability of sample Skewness and Kurtosis and decreasing mean Kurtosis of these series alter the frequency distribution shape of the realised values of the coloured stochastic processes. These changes in distribution shape alter patterns in the probability of single and series of extreme conditions. We show that the reduced extinction risk for undercompensating (slow growing) populations in red environments previously predicted with traditional 1/f methods is an artefact of changes in the distribution shapes of the environmental series. This is demonstrated by comparison with coloured series controlled to be normally distributed using spectral mimicry. Changes in the distribution shape that arise using traditional methods lead to underestimation of extinction risk in normally distributed, red 1/f environments. AR(1) methods also underestimate extinction risks in traditionally generated red environments. This work synthesises previous results and provides further insight into the processes driving extinction risk in model populations. We must let the characteristics of known natural environmental covariates (e.g., colour and distribution shape) guide us in our choice of how to best model the impact of coloured environmental variation on population dynamics.

Effect of colouring green stage zirconia on the adhesion of veneering ceramics with different thermal expansion coefficients

PubMed Central

Aktas, Guliz; Sahin, Erdal; Vallittu, Pekka; Özcan, Mutlu; Lassila, Lippo

2013-01-01

This study evaluated the adhesion of zirconia core ceramics with their corresponding veneering ceramics, having different thermal expansion coefficients (TECs), when zirconia ceramics were coloured at green stage. Zirconia blocks (N=240; 6 mm×7 mm×7 mm) were manufactured from two materials namely, ICE Zirconia (Group 1) and Prettau Zirconia (Group 2). In their green stage, they were randomly divided into two groups. Half of the specimens were coloured with colouring liquid (shade A2). Three different veneering ceramics with different TEC (ICE Ceramic, GC Initial Zr and IPS e.max Ceram) were fired on both coloured and non-coloured zirconia cores. Specimens of high noble alloys (Esteticor Plus) veneered with ceramic (VM 13) (n=16) acted as the control group. Core–veneer interface of the specimens were subjected to shear force in the Universal Testing Machine (0.5 mm⋅min−1). Neither the zirconia core material (P=0.318) nor colouring (P=0.188) significantly affected the results (three-way analysis of variance, Tukey's test). But the results were significantly affected by the veneering ceramic (P=0.000). Control group exhibited significantly higher mean bond strength values (45.7±8) MPa than all other tested groups ((27.1±4.1)−(39.7±4.7) and (27.4±5.6)−(35.9±4.7) MPa with and without colouring, respectively) (P<0.001). While in zirconia–veneer test groups, predominantly mixed type of failures were observed with the veneering ceramic covering <1/3 of the substrate surface, in the metal–ceramic group, veneering ceramic was left adhered >1/3 of the metal surface. Colouring zirconia did not impair adhesion of veneering ceramic, but veneering ceramic had a significant influence on the core–veneer adhesion. Metal–ceramic adhesion was more reliable than all zirconia–veneer ceramics tested. PMID:24158142

Effect of colouring green stage zirconia on the adhesion of veneering ceramics with different thermal expansion coefficients.

PubMed

Aktas, Guliz; Sahin, Erdal; Vallittu, Pekka; Ozcan, Mutlu; Lassila, Lippo

2013-12-01

This study evaluated the adhesion of zirconia core ceramics with their corresponding veneering ceramics, having different thermal expansion coefficients (TECs), when zirconia ceramics were coloured at green stage. Zirconia blocks (N=240; 6 mm×7 mm×7 mm) were manufactured from two materials namely, ICE Zirconia (Group 1) and Prettau Zirconia (Group 2). In their green stage, they were randomly divided into two groups. Half of the specimens were coloured with colouring liquid (shade A2). Three different veneering ceramics with different TEC (ICE Ceramic, GC Initial Zr and IPS e.max Ceram) were fired on both coloured and non-coloured zirconia cores. Specimens of high noble alloys (Esteticor Plus) veneered with ceramic (VM 13) (n=16) acted as the control group. Core-veneer interface of the specimens were subjected to shear force in the Universal Testing Machine (0.5 mm⋅min(-1)). Neither the zirconia core material (P=0.318) nor colouring (P=0.188) significantly affected the results (three-way analysis of variance, Tukey's test). But the results were significantly affected by the veneering ceramic (P=0.000). Control group exhibited significantly higher mean bond strength values (45.7±8) MPa than all other tested groups ((27.1±4.1)-(39.7±4.7) and (27.4±5.6)-(35.9±4.7) MPa with and without colouring, respectively) (P<0.001). While in zirconia-veneer test groups, predominantly mixed type of failures were observed with the veneering ceramic covering <1/3 of the substrate surface, in the metal-ceramic group, veneering ceramic was left adhered >1/3 of the metal surface. Colouring zirconia did not impair adhesion of veneering ceramic, but veneering ceramic had a significant influence on the core-veneer adhesion. Metal-ceramic adhesion was more reliable than all zirconia-veneer ceramics tested.

Prediction of a nail polish colour applied on a nail.

PubMed

Monpeurt, C; Cinotti, E; Razafindrakoto, J; Rubegni, P; Fimiani, M; Perrot, J L; Hebert, M

2018-02-01

The colour of a nail polish varies according to the nail on which it is applied. The objective of this study was to predict the colour of the nail polish on a given nail and to study how the colour varies depending on the nail polish thickness. Six nail polishes were applied in one, two and three layers on the nails of one subject, thus forming eighteen samples. The spectral reflectances of the eighteen nail polishes applied on the nails with different thicknesses were obtained by spectrophotometry. The spectral reflectances of the nails without polish were also measured using the same technique. The thicknesses of nail polishes were measured by high-definition optical coherence tomography (HD-OCT). Then, to determine the physical parameters of the nail polish itself, we applied the six nail polishes on an opacity drawdown chart and we measured the spectral reflectance and the thickness of each patch using spectrophotometry and HD-OCT, respectively. The Kubelka-Munk theory was used to get the predicted spectral reflectance of the nail polish applied on the nail according to the polish thickness by knowing the parameter of the polish itself and the spectral reflectance of the nail. The predicted spectral reflectances were finally compared with those measured directly on the nails. The predicted spectral reflectances were rather close to measured ones. Consequently, knowing the colour of the nail without polish and the optical parameters of the nail polish itself, we can estimate the colour of the nail polish applied on the nail depending on its thickness. Our study showed that the Kubelka-Munk theory can be used to predict the nail polish colour. The ability to predict the real colour of a nail polish applied on a nail could help a nail polish manufacturer to improve his polish formulae in order to obtain a precise colour. © 2017 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Mechanisms, functions and ecology of colour vision in the honeybee.

PubMed

Hempel de Ibarra, N; Vorobyev, M; Menzel, R

2014-06-01

Research in the honeybee has laid the foundations for our understanding of insect colour vision. The trichromatic colour vision of honeybees shares fundamental properties with primate and human colour perception, such as colour constancy, colour opponency, segregation of colour and brightness coding. Laborious efforts to reconstruct the colour vision pathway in the honeybee have provided detailed descriptions of neural connectivity and the properties of photoreceptors and interneurons in the optic lobes of the bee brain. The modelling of colour perception advanced with the establishment of colour discrimination models that were based on experimental data, the Colour-Opponent Coding and Receptor Noise-Limited models, which are important tools for the quantitative assessment of bee colour vision and colour-guided behaviours. Major insights into the visual ecology of bees have been gained combining behavioural experiments and quantitative modelling, and asking how bee vision has influenced the evolution of flower colours and patterns. Recently research has focussed on the discrimination and categorisation of coloured patterns, colourful scenes and various other groupings of coloured stimuli, highlighting the bees' behavioural flexibility. The identification of perceptual mechanisms remains of fundamental importance for the interpretation of their learning strategies and performance in diverse experimental tasks.

The neural correlate of colour distances revealed with competing synaesthetic and real colours.

PubMed

Laeng, Bruno; Hugdahl, Kenneth; Specht, Karsten

2011-03-01

Synaesthetes claim to perceive illusory colours when reading alphanumeric symbols so that two colours are said to be bound to the same letter or digit (i.e., the colour of the ink, e.g., black, and an additional, synaesthetic, colour). To explore the neural correlates of this phenomenon, we used a Stroop single-letter colour-naming task and found that distances in colour space between the illusory and real colours of a letter target (as computed from either the RGB or CIExyY coordinates of colours) systematically influenced the degree of neuronal activation in colour-processing brain regions. The synaesthetes also activated the same fronto-parietal network during the classic colour-word Stroop task and single-letter tasks. We conclude that the same neural substrate that supports the conscious experience of colour, as triggered by physical wavelength, supports the experience of synaesthetic colours. Thus, two colour attributes (one that is wavelength-dependent and one that is illusory) can be bound to the same stimulus position and simultaneously engage the colour areas in proportion to their similarity in colour space. Copyright © 2009 Elsevier Srl. All rights reserved.

Measurements and modelling of the influence of dentine colour and enamel on tooth colour.

PubMed

Battersby, Paul D; Battersby, Stephen J

2015-03-01

We provide a quantitative predictive model for the extent to which coloured dentine, visible through the enamel, contributes to tooth colour. Our model uses (L(*),a(*),b(*)) measurements rather than spectral measurements. We have used a model system, composed of a slice of bovine enamel placed on top of coloured paper. We have measured the colour of the enamel-paper combination, as an analogue for a tooth, and have related this to the colour of the paper, as an analogue for dentine. By changing the paper colour, we have been able to explore how the colour of dentine determines tooth colour, according to our model system. We have also compared hydrated and desiccated samples. In qualitative terms, superimposing the enamel on top of the paper increases the "lightness" for all colours tested except white while simultaneously reducing the chromaticity, a measure of the extent to which the colour differs from grey. Desiccated enamel is much more effective at increasing the lightness and reducing the chromaticity than hydrated enamel. Quantitatively, our measurements are reproduced by the mathematical model we have developed to within 2% in "lightness" and about 8% in chromaticity. We are able to predict the colour of an analogue for a tooth, composed of bovine enamel and coloured paper, from the colour of an analogue for the dentine, the coloured paper alone, with good accuracy. This understanding provides insights into the role of dentine colour in determining tooth colour. Our work helps quantify the importance of dentine colour, compared to other, extrinsic causes of colour, such as staining, in determining the visible colour of teeth. Our predicted colours represent a baseline to which extrinsic sources will add. Copyright © 2015. Published by Elsevier Ltd.

Covert colour processing in colour agnosia.

PubMed

Nijboer, Tanja C W; van Zandvoort, Martine J E; de Haan, Edward H F

2006-01-01

Patients with colour agnosia can perceive colours and are able to match coloured patches on hue, but are unable to identify or categorise colours. It is a rare condition and there is as yet no agreement on the clinical definition or a generally accepted explanation. In line with observations from object agnosia and prosopagnosia, we hypothesised that (some of) these patients might still be able to process colour information at an implicit level. In this study, we investigated this possibility of implicit access to colour semantics and colour names in a man (MAH) who suffers from developmental colour agnosia. We designed two experimental computer tasks: an associative colour priming task with a lexical decision response and a reversed Stroop task. The results of these experiments suggest that there is indeed automatic processing of colour, although MAH was unable to explicitly use colour information.

Foundations for Measuring Volume Rendering Quality

NASA Technical Reports Server (NTRS)

Williams, Peter L.; Uselton, Samuel P.; Chancellor, Marisa K. (Technical Monitor)

1997-01-01

The goal of this paper is to provide a foundation for objectively comparing volume rendered images. The key elements of the foundation are: (1) a rigorous specification of all the parameters that need to be specified to define the conditions under which a volume rendered image is generated; (2) a methodology for difference classification, including a suite of functions or metrics to quantify and classify the difference between two volume rendered images that will support an analysis of the relative importance of particular differences. The results of this method can be used to study the changes caused by modifying particular parameter values, to compare and quantify changes between images of similar data sets rendered in the same way, and even to detect errors in the design, implementation or modification of a volume rendering system. If one has a benchmark image, for example one created by a high accuracy volume rendering system, the method can be used to evaluate the accuracy of a given image.

Distributed rendering for multiview parallax displays

NASA Astrophysics Data System (ADS)

Annen, T.; Matusik, W.; Pfister, H.; Seidel, H.-P.; Zwicker, M.

2006-02-01

3D display technology holds great promise for the future of television, virtual reality, entertainment, and visualization. Multiview parallax displays deliver stereoscopic views without glasses to arbitrary positions within the viewing zone. These systems must include a high-performance and scalable 3D rendering subsystem in order to generate multiple views at real-time frame rates. This paper describes a distributed rendering system for large-scale multiview parallax displays built with a network of PCs, commodity graphics accelerators, multiple projectors, and multiview screens. The main challenge is to render various perspective views of the scene and assign rendering tasks effectively. In this paper we investigate two different approaches: Optical multiplexing for lenticular screens and software multiplexing for parallax-barrier displays. We describe the construction of large-scale multi-projector 3D display systems using lenticular and parallax-barrier technology. We have developed different distributed rendering algorithms using the Chromium stream-processing framework and evaluate the trade-offs and performance bottlenecks. Our results show that Chromium is well suited for interactive rendering on multiview parallax displays.

The Formation and Binding of Gold Nanoparticles onto Wool Fibres

NASA Astrophysics Data System (ADS)

Johnston, James H.; Burridge, Kerstin A.; Kelly, Fern M.

2009-07-01

This paper presents the novel use of nanosize gold with different plasmon resonance colours, as stable colourfast colourants on wool fibres for use in high quality fabrics and textiles. The gold nanoparticles are synthesised by the controlled reduction of Au3+ in the AuCl4- complex to Au0 onto the surface of the wool where they attach to the S in the cystine amino acids in wool keratin proteins. Scanning electronmicroscopy shows the nanoparticles are present on the cuticles of the fibre surface and are concentrated at the edges of these cuticles. EDS analysis shows a strong correlation of Au with S and X-ray photoelectron spectroscopy suggests Au-S bond formation. Hence the nanogold colourants are chemically bound to the wool fibre surface and do not fade as traditional organic dyes do. A range of coloured fibres have been produced.

Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierrae from California

USGS Publications Warehouse

Purvis, O.W.; Bennett, J.P.; Spratt, J.

2011-01-01

An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour. Copyright ?? 2011 British Lichen Society.

Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierra from California

USGS Publications Warehouse

Purvis, O.W.; Bennett, J.P.; Spratt, J.

2011-01-01

An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour.

Evaluation of a visual layering methodology for colour coding control room displays.

PubMed

Van Laar, Darren; Deshe, Ofer

2002-07-01

Eighteen people participated in an experiment in which they were asked to search for targets on control room like displays which had been produced using three different coding methods. The monochrome coding method displayed the information in black and white only, the maximally discriminable method contained colours chosen for their high perceptual discriminability, the visual layers method contained colours developed from psychological and cartographic principles which grouped information into a perceptual hierarchy. The visual layers method produced significantly faster search times than the other two coding methods which did not differ significantly from each other. Search time also differed significantly for presentation order and for the method x order interaction. There was no significant difference between the methods in the number of errors made. Participants clearly preferred the visual layers coding method. Proposals are made for the design of experiments to further test and develop the visual layers colour coding methodology.

Actively addressed single pixel full-colour plasmonic display

NASA Astrophysics Data System (ADS)

Franklin, Daniel; Frank, Russell; Wu, Shin-Tson; Chanda, Debashis

2017-05-01

Dynamic, colour-changing surfaces have many applications including displays, wearables and active camouflage. Plasmonic nanostructures can fill this role by having the advantages of ultra-small pixels, high reflectivity and post-fabrication tuning through control of the surrounding media. However, previous reports of post-fabrication tuning have yet to cover a full red-green-blue (RGB) colour basis set with a single nanostructure of singular dimensions. Here, we report a method which greatly advances this tuning and demonstrates a liquid crystal-plasmonic system that covers the full RGB colour basis set, only as a function of voltage. This is accomplished through a surface morphology-induced, polarization-dependent plasmonic resonance and a combination of bulk and surface liquid crystal effects that manifest at different voltages. We further demonstrate the system's compatibility with existing LCD technology by integrating it with a commercially available thin-film-transistor array. The imprinted surface interfaces readily with computers to display images as well as video.

The Formation and Binding of Gold Nanoparticles onto Wool Fibres

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

Johnston, James H.; Burridge, Kerstin A.; Kelly, Fern M.

2009-07-23

This paper presents the novel use of nanosize gold with different plasmon resonance colours, as stable colourfast colourants on wool fibres for use in high quality fabrics and textiles. The gold nanoparticles are synthesised by the controlled reduction of Au{sup 3+} in the AuCl{sub 4}{sup -} complex to Au{sup 0} onto the surface of the wool where they attach to the S in the cystine amino acids in wool keratin proteins. Scanning electronmicroscopy shows the nanoparticles are present on the cuticles of the fibre surface and are concentrated at the edges of these cuticles. EDS analysis shows a strong correlationmore » of Au with S and X-ray photoelectron spectroscopy suggests Au-S bond formation. Hence the nanogold colourants are chemically bound to the wool fibre surface and do not fade as traditional organic dyes do. A range of coloured fibres have been produced.« less

Determination of synthetic food dyes in commercial soft drinks by TLC and ion-pair HPLC.

PubMed

de Andrade, Francisca Ivani; Florindo Guedes, Maria Izabel; Pinto Vieira, Ícaro Gusmão; Pereira Mendes, Francisca Noélia; Salmito Rodrigues, Paula Alves; Costa Maia, Carla Soraya; Marques Ávila, Maria Marlene; de Matos Ribeiro, Luzara

2014-08-15

Synthetic food colourings were analyzed on commercial carbonated orange and grape soft drinks produced in Ceará State, Brazil. Tartrazine (E102), Amaranth (E123), Sunset Yellow (E110) and Brilliant Blue (E133) were extracted from soft drinks using C18 SPE and identified by thin layer chromatography (TLC), this method was used to confirm the composition of food colouring in soft drinks stated on label. The concentration of food colouring in soft drink was determined by ion-pair high performance liquid chromatography with photodiode array detection. The results obtained with the samples confirm that the identification and quantification methods are recommended for quality control of the synthetic colours in soft drinks, as well as to determine whether the levels and lables complies with the recommendations of food dyes legislation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inkjet printing-based volumetric display projecting multiple full-colour 2D patterns

NASA Astrophysics Data System (ADS)

Hirayama, Ryuji; Suzuki, Tomotaka; Shimobaba, Tomoyoshi; Shiraki, Atsushi; Naruse, Makoto; Nakayama, Hirotaka; Kakue, Takashi; Ito, Tomoyoshi

2017-04-01

In this study, a method to construct a full-colour volumetric display is presented using a commercially available inkjet printer. Photoreactive luminescence materials are minutely and automatically printed as the volume elements, and volumetric displays are constructed with high resolution using easy-to-fabricate means that exploit inkjet printing technologies. The results experimentally demonstrate the first prototype of an inkjet printing-based volumetric display composed of multiple layers of transparent films that yield a full-colour three-dimensional (3D) image. Moreover, we propose a design algorithm with 3D structures that provide multiple different 2D full-colour patterns when viewed from different directions and experimentally demonstrate prototypes. It is considered that these types of 3D volumetric structures and their fabrication methods based on widely deployed existing printing technologies can be utilised as novel information display devices and systems, including digital signage, media art, entertainment and security.

Towards metal chalcogenide nanowire-based colour-sensitive photodetectors

NASA Astrophysics Data System (ADS)

Butanovs, Edgars; Butikova, Jelena; Zolotarjovs, Aleksejs; Polyakov, Boris

2018-01-01

In recent years, nanowires have been shown to exhibit high photosensitivities, and, therefore are of interest in a variety of optoelectronic applications, for example, colour-sensitive photodetectors. In this study, we fabricated two-terminal PbS, In2S3, CdS and ZnSe single-nanowire photoresistor devices and tested applicability of these materials under the same conditions for colour-sensitive (405 nm, 532 nm and 660 nm) light detection. Nanowires were grown via atmospheric pressure chemical vapour transport method, their structure and morphology were characterized by scanning and transmission electron microscopy (SEM and TEM), X-ray diffraction (XRD), and optical properties were investigated with photoluminescence (PL) measurements. Single-nanowire photoresistors were fabricated via in situ nanomanipulations inside SEM, using focused ion beam (FIB) cutting and electron-beam-assisted platinum welding; their current-voltage characteristics and photoresponse values were measured. Applicability of the tested nanowire materials for colour-sensitive light detection is discussed.

Image Simulation and Assessment of the Colour and Spatial Capabilities of the Colour and Stereo Surface Imaging System (CaSSIS) on the ExoMars Trace Gas Orbiter

NASA Astrophysics Data System (ADS)

Tornabene, Livio L.; Seelos, Frank P.; Pommerol, Antoine; Thomas, Nicholas; Caudill, C. M.; Becerra, Patricio; Bridges, John C.; Byrne, Shane; Cardinale, Marco; Chojnacki, Matthew; Conway, Susan J.; Cremonese, Gabriele; Dundas, Colin M.; El-Maarry, M. R.; Fernando, Jennifer; Hansen, Candice J.; Hansen, Kayle; Harrison, Tanya N.; Henson, Rachel; Marinangeli, Lucia; McEwen, Alfred S.; Pajola, Maurizio; Sutton, Sarah S.; Wray, James J.

2018-02-01

This study aims to assess the spatial and visible/near-infrared (VNIR) colour/spectral capabilities of the 4-band Colour and Stereo Surface Imaging System (CaSSIS) aboard the ExoMars 2016 Trace Grace Orbiter (TGO). The instrument response functions for the CaSSIS imager was used to resample spectral libraries, modelled spectra and to construct spectrally ( i.e., in I/F space) and spatially consistent simulated CaSSIS image cubes of various key sites of interest and for ongoing scientific investigations on Mars. Coordinated datasets from Mars Reconnaissance Orbiter (MRO) are ideal, and specifically used for simulating CaSSIS. The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) provides colour information, while the Context Imager (CTX), and in a few cases the High-Resolution Imaging Science Experiment (HiRISE), provides the complementary spatial information at the resampled CaSSIS unbinned/unsummed pixel resolution (4.6 m/pixel from a 400-km altitude). The methodology used herein employs a Gram-Schmidt spectral sharpening algorithm to combine the ˜18-36 m/pixel CRISM-derived CaSSIS colours with I/F images primarily derived from oversampled CTX images. One hundred and eighty-one simulated CaSSIS 4-colour image cubes (at 18-36 m/pixel) were generated (including one of Phobos) based on CRISM data. From these, thirty-three "fully"-simulated image cubes of thirty unique locations on Mars ( i.e., with 4 colour bands at 4.6 m/pixel) were made. All simulated image cubes were used to test both the colour capabilities of CaSSIS by producing standard colour RGB images, colour band ratio composites (CBRCs) and spectral parameters. Simulated CaSSIS CBRCs demonstrated that CaSSIS will be able to readily isolate signatures related to ferrous (Fe2+) iron- and ferric (Fe3+) iron-bearing deposits on the surface of Mars, ices and atmospheric phenomena. Despite the lower spatial resolution of CaSSIS when compared to HiRISE, the results of this work demonstrate that CaSSIS will not only compliment HiRISE-scale studies of various geological and seasonal phenomena, it will also enhance them by providing additional colour and geologic context through its wider and longer full-colour coverage (˜9.4 × 50 km), and its increased sensitivity to iron-bearing materials from its two IR bands (RED and NIR). In a few examples, subtle surface changes that were not easily detected by HiRISE were identified in the simulated CaSSIS images. This study also demonstrates the utility of the Gram-Schmidt spectral pan-sharpening technique to extend VNIR colour/spectral capabilities from a lower spatial resolution colour/spectral dataset to a single-band or panchromatic image greyscale image with higher resolution. These higher resolution colour products (simulated CaSSIS or otherwise) are useful as means to extend both geologic context and mapping of datasets with coarser spatial resolutions. The results of this study indicate that the TGO mission objectives, as well as the instrument-specific mission objectives, will be achievable with CaSSIS.

Performance assessment of Vita Easy Shade spectrophotometer on colour measurement of aesthetic dental materials.

PubMed

AlGhazali, N; Burnside, G; Smith, R W; Preston, A J; Jarad, F D

2011-12-01

Four different shades were used to produce 20 samples of resin-based composite and 20 samples of porcelain to evaluate the performance ability of an intra oral test spectrophotometer compared to a reference spectrophotometer. The absolute colour coordinates CIELAB values measured with both spectrophotometers were significantly different (p < 0.001). However, a high correlation was found (p < 0.001) despite the low concordance noticed. The colour difference deltaE* values calculated between different shades also were significantly different between both spectrophotometers (p < 0.05). Therefore, the Easy Shade can be used in dental practice and dental research with some limitations.

An ecological alternative to Snodgrass & Vanderwart: 360 high quality colour images with norms for seven psycholinguistic variables.

PubMed

Moreno-Martínez, Francisco Javier; Montoro, Pedro R

2012-01-01

This work presents a new set of 360 high quality colour images belonging to 23 semantic subcategories. Two hundred and thirty-six Spanish speakers named the items and also provided data from seven relevant psycholinguistic variables: age of acquisition, familiarity, manipulability, name agreement, typicality and visual complexity. Furthermore, we also present lexical frequency data derived from Internet search hits. Apart from the high number of variables evaluated, knowing that it affects the processing of stimuli, this new set presents important advantages over other similar image corpi: (a) this corpus presents a broad number of subcategories and images; for example, this will permit researchers to select stimuli of appropriate difficulty as required, (e.g., to deal with problems derived from ceiling effects); (b) the fact of using coloured stimuli provides a more realistic, ecologically-valid, representation of real life objects. In sum, this set of stimuli provides a useful tool for research on visual object- and word-processing, both in neurological patients and in healthy controls.

Put on that colour, it fits your emotion: Colour appropriateness as a function of expressed emotion.

PubMed

Dael, Nele; Perseguers, Marie-Noëlle; Marchand, Cynthia; Antonietti, Jean-Philippe; Mohr, Christine

2016-01-01

People associate affective meaning with colour, and this may influence decisions about colours. Hue is traditionally considered the most salient descriptor of colour and colour-affect associations, although colour brightness and saturation seem to have particularly strong affective connotations. To test whether colour choices can be driven by emotion, we investigated whether and how colour hue, brightness, and saturation are systematically associated with bodily expressions of positive (joy) and negative (fear) emotions. Twenty-five non-colour-blind participants viewed videos of these expressions and selected for each video the most appropriate colour using colour sliders providing values for hue, brightness, and saturation. The overall colour choices were congruent with the expressed emotion--that is, participants selected brighter and more saturated colours for joy expressions than for fear expressions. Also, colours along the red-yellow spectrum were deemed more appropriate for joy expressions and cyan-bluish hues for fear expressions. The current study adds further support to the role of emotion in colour choices by (a) showing that emotional information is spontaneously used in an unconstrained choice setting, (b) extending to ecologically valid stimuli occurring in everyday encounters (dressed bodies), and (c) suggesting that all colour parameters are likely to be important when processing affective nonverbal person information, though not independently from each other.

Selection for increased muscling in Angus cattle did not increase the glycolytic potential or negatively impact pH decline, retail colour stability or mineral content.

PubMed

McGilchrist, P; Greenwood, P L; Pethick, D W; Gardner, G E

2016-04-01

This study determined the impact of selection for greater muscling in Angus cattle on myofibre characteristics, muscle enzymatics, retail colour stability, pH decline and mineral content of the semimembranosus (SM), semitendinosus (ST) and longissimus thoracis (LT). Muscle from 10 low muscled (low) and 11 high muscled (high) steers were analysed. The high steers had myofibres 22% and 24% larger in cross-sectional area in the SM and ST (P<0.05), and 8.6% less type IIX myofibres in the LT than the low steers (P<0.05). The highs had 4.9% lower lactate dehydrogenase activity, 10.2% and 12.3% higher citrate synthase and isocitrate dehydrogenase activity than lows (P<0.05). The highs had 27% more iron in the LT (P<0.05). The results indicate that the oxidative capacity of muscle can be maintained in more muscular cattle with no detrimental effects to mineral content, pH decline or retail colour stability. Myofibre hypertrophy is one mechanism leading to greater muscle mass of these high muscled cattle. Copyright © 2015 Elsevier Ltd. All rights reserved.

Birds see the true colours of fruits to live off the fat of the land

PubMed Central

Schaefer, H. Martin; Valido, Alfredo; Jordano, Pedro

2014-01-01

Communication is a characteristic of life, but its reliability and basic definition are hotly debated. Theory predicts that trade among mutualists requires high reliability. Here, we show that moderate reliability already allows mutualists to optimize their rewards. The colours of Mediterranean fleshy-fruits indicate lipid rewards (but not other nutrients) to avian seed dispersers on regional and local scales. On the regional scale, fruits with high lipid content were significantly darker and less chromatic than congeners with lower lipid content. On the local scale, two warbler species (Sylvia atricapilla and Sylvia borin) selected fruit colours that were less chromatic, and thereby maximized their intake of lipids—a critical resource during migration and wintering. Crucially, birds were able to maximize lipid rewards with moderate reliability from visual fruit colours (r2 = 0.44–0.60). We suggest that mutualisms require only that any association between the quality and sensory aspects of signallers is learned through multiple, repeated interactions. Because these conditions are often fulfilled, also in social communication systems, we contend that selection on reliability is less intense than hitherto assumed. This may contribute to explaining the extraordinary diversity of signals, including that of plant reproductive displays. PMID:24403330

Colours sometimes count: awareness and bidirectionality in grapheme-colour synaesthesia.

PubMed

Johnson, Addie; Jepma, Marieke; de Jong, Ritske

2007-10-01

Three experiments were conducted with 10 grapheme-colour synaesthetes and 10 matched controls to investigate (a) whether awareness of the inducer grapheme is necessary for synaesthetic colour induction and (b) whether grapheme-colour synaesthesia may be bidirectional in the sense that not only do graphemes induce colours, but that colours influence the processing of graphemes. Using attentional blink and Stroop paradigms with digit targets, we found that some synaesthetes did report "seeing" synaesthetic colours even when they were not able to report the inducing digit. Moreover, congruency effects (effects of matching the colour of digit presentation with the synaesthetic colour associated with that digit) suggested that grapheme-colour synaesthesia can be bidirectional, at least for some synaesthetes.

Prefrontal cortex contributions to episodic retrieval monitoring and evaluation.

PubMed

Cruse, Damian; Wilding, Edward L

2009-11-01

Although the prefrontal cortex (PFC) plays roles in episodic memory judgments, the specific processes it supports are not understood fully. Event-related potential (ERP) studies of episodic retrieval have revealed an electrophysiological modulation - the right-frontal ERP old/new effect - which is thought to reflect activity in PFC. The functional significance of this old/new effect remains a matter of debate, and this study was designed to test two accounts: (i) that the effect indexes processes linked to the monitoring or evaluation of the products of retrieval in service of task demands, or (ii) that it indexes the number of internal decisions required for a task judgment. Participants studied words in one of two colours. In a subsequent retrieval task, old (studied) and new words were presented in a neutral colour. Participants made initial old/new judgments, along with study colour judgments to words thought to be old. They also indicated their confidence (high/low) in the colour decision. Right-frontal ERP old/new effects were larger for high than for low confidence correct colour judgments, and the magnitude of the right-frontal effect was correlated with the proportions of low confidence judgments that were made. Because the numbers of decisions associated with these response categories are equivalent, these findings do not support a decision-based account of the right-frontal ERP old/new effect. Rather, the correlation between confidence and the magnitude of the effect links it with retrieval monitoring and evaluation processes.

Processing-in-Memory Enabled Graphics Processors for 3D Rendering

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

Xie, Chenhao; Song, Shuaiwen; Wang, Jing

2017-02-06

The performance of 3D rendering of Graphics Processing Unit that convents 3D vector stream into 2D frame with 3D image effects significantly impact users’ gaming experience on modern computer systems. Due to the high texture throughput in 3D rendering, main memory bandwidth becomes a critical obstacle for improving the overall rendering performance. 3D stacked memory systems such as Hybrid Memory Cube (HMC) provide opportunities to significantly overcome the memory wall by directly connecting logic controllers to DRAM dies. Based on the observation that texel fetches significantly impact off-chip memory traffic, we propose two architectural designs to enable Processing-In-Memory based GPUmore » for efficient 3D rendering.« less

A unified framework for building high performance DVEs

NASA Astrophysics Data System (ADS)

Lei, Kaibin; Ma, Zhixia; Xiong, Hua

2011-10-01

A unified framework for integrating PC cluster based parallel rendering with distributed virtual environments (DVEs) is presented in this paper. While various scene graphs have been proposed in DVEs, it is difficult to enable collaboration of different scene graphs. This paper proposes a technique for non-distributed scene graphs with the capability of object and event distribution. With the increase of graphics data, DVEs require more powerful rendering ability. But general scene graphs are inefficient in parallel rendering. The paper also proposes a technique to connect a DVE and a PC cluster based parallel rendering environment. A distributed multi-player video game is developed to show the interaction of different scene graphs and the parallel rendering performance on a large tiled display wall.

Framework for cognitive analysis of dynamic perfusion computed tomography with visualization of large volumetric data

NASA Astrophysics Data System (ADS)

Hachaj, Tomasz; Ogiela, Marek R.

2012-10-01

The proposed framework for cognitive analysis of perfusion computed tomography images is a fusion of image processing, pattern recognition, and image analysis procedures. The output data of the algorithm consists of: regions of perfusion abnormalities, anatomy atlas description of brain tissues, measures of perfusion parameters, and prognosis for infracted tissues. That information is superimposed onto volumetric computed tomography data and displayed to radiologists. Our rendering algorithm enables rendering large volumes on off-the-shelf hardware. This portability of rendering solution is very important because our framework can be run without using expensive dedicated hardware. The other important factors are theoretically unlimited size of rendered volume and possibility of trading of image quality for rendering speed. Such rendered, high quality visualizations may be further used for intelligent brain perfusion abnormality identification, and computer aided-diagnosis of selected types of pathologies.

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 handicap of abnormal colour vision.

PubMed

Cole, Barry L

2004-07-01

All people with abnormal colour vision, except for a few mildly affected deuteranomals, report that they experience problems with colour in everyday life and at work. Contemporary society presents them with increasing problems because colour is now so widely used in printed materials and in computer displays. Equal opportunity law gives them protection against unfair discrimination in employment, so a decision to exclude a person from employment on the grounds of abnormal colour vision must now be well supported by good evidence and sound argument. This paper reviews the investigations that have contributed to understanding the nature and consequences of the problems they have. All those with abnormal colour vision are at a disadvantage with comparative colour tasks that involve precise matching of colours or discrimination of fine colour differences either because of their loss of colour discrimination or anomalous perception of metamers. The majority have problems when colour is used to code information, in man-made colour codes and in naturally occurring colour codes that signal ripeness of fruit, freshness of meat or illness. They can be denied the benefit of colour to mark out objects and organise complex visual displays. They may be unreliable when a colour name is used as an identifier. They are slower and less successful in search when colour is an attribute of the target object or is used to organise the visual display. Because those with the more severe forms of abnormal colour vision perceive a very limited gamut of colours, they are at a disadvantage in the pursuit and appreciation of those forms of art that use colour.

Developmental colour agnosia.

PubMed

van Zandvoort, Martine J E; Nijboer, Tanja C W; de Haan, Edward

2007-08-01

Colour agnosia concerns the inability to recognise colours despite intact colour perception, semantic memory for colour information, and colour naming. Patients with selective colour agnosia have been described and the deficit is associated with left hemisphere damage. Here we report a case study of a 43-year-old man who was referred to us with a stroke in his right cerebellar hemisphere. During the standard assessment it transpired that he was unable to name coloured patches. Detailed assessment of his colour processing showed that he suffers from a selective colour agnosia. As he claimed to have had this problem all his life, and the fact that the infratentorial infarct that he had incurred was in an area far away from the brain structures that are known to be involved in colour processing, we suggest that he is the first reported case of developmental colour agnosia.

16 CFR 1610.39 - Shipments under section 11(c) of the Act.

Code of Federal Regulations, 2014 CFR

2014-01-01

... duly authorized agent so as to render them not so highly flammable under the provisions of section 4 of.... 1610.39 Section 1610.39 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT... processing to render them not so highly flammable as to be dangerous when worn by individuals, shall contain...

16 CFR 1610.39 - Shipments under section 11(c) of the Act.

Code of Federal Regulations, 2010 CFR

2010-01-01

... duly authorized agent so as to render them not so highly flammable under the provisions of section 4 of.... 1610.39 Section 1610.39 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT... processing to render them not so highly flammable as to be dangerous when worn by individuals, shall contain...

16 CFR 1610.39 - Shipments under section 11(c) of the Act.

Code of Federal Regulations, 2011 CFR

2011-01-01

... duly authorized agent so as to render them not so highly flammable under the provisions of section 4 of.... 1610.39 Section 1610.39 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT... processing to render them not so highly flammable as to be dangerous when worn by individuals, shall contain...

16 CFR 1610.39 - Shipments under section 11(c) of the Act.

Code of Federal Regulations, 2012 CFR

2012-01-01

... duly authorized agent so as to render them not so highly flammable under the provisions of section 4 of.... 1610.39 Section 1610.39 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT... processing to render them not so highly flammable as to be dangerous when worn by individuals, shall contain...

A data distributed parallel algorithm for ray-traced volume rendering

NASA Technical Reports Server (NTRS)

Ma, Kwan-Liu; Painter, James S.; Hansen, Charles D.; Krogh, Michael F.

1993-01-01

This paper presents a divide-and-conquer ray-traced volume rendering algorithm and a parallel image compositing method, along with their implementation and performance on the Connection Machine CM-5, and networked workstations. This algorithm distributes both the data and the computations to individual processing units to achieve fast, high-quality rendering of high-resolution data. The volume data, once distributed, is left intact. The processing nodes perform local ray tracing of their subvolume concurrently. No communication between processing units is needed during this locally ray-tracing process. A subimage is generated by each processing unit and the final image is obtained by compositing subimages in the proper order, which can be determined a priori. Test results on both the CM-5 and a group of networked workstations demonstrate the practicality of our rendering algorithm and compositing method.

A Parallel Rendering Algorithm for MIMD Architectures

NASA Technical Reports Server (NTRS)

Crockett, Thomas W.; Orloff, Tobias

1991-01-01

Applications such as animation and scientific visualization demand high performance rendering of complex three dimensional scenes. To deliver the necessary rendering rates, highly parallel hardware architectures are required. The challenge is then to design algorithms and software which effectively use the hardware parallelism. A rendering algorithm targeted to distributed memory MIMD architectures is described. For maximum performance, the algorithm exploits both object-level and pixel-level parallelism. The behavior of the algorithm is examined both analytically and experimentally. Its performance for large numbers of processors is found to be limited primarily by communication overheads. An experimental implementation for the Intel iPSC/860 shows increasing performance from 1 to 128 processors across a wide range of scene complexities. It is shown that minimal modifications to the algorithm will adapt it for use on shared memory architectures as well.

Detection and discrimination of colour, a comparison of physiological and psychophysical data

NASA Astrophysics Data System (ADS)

Valberg, A.; Lee, B. B.

1989-01-01

Whereas the physiological basis of colorimetry (colour matches) is well understood in terms of the trireceptor theory of colour vision, colour discrimination and scaling still lack a comparable foundation. We present here experimental data that demonstrate how sensitivity and responsiveness of different types of cone-opponent and non-opponent cells of the macaque monkey correlate with human threshold sensitivity on the one hand, and how they in combination can be used to construct a suprathreshold equidistant colour space. Psychophysical thresholds correlate well with the threshold envelope of the most sensitive cells when stimuli are projected upon a steady white background. Detection thresholds for stimuli of differing wavelength and purity (saturation) generally indicate a transition from a phasic non-opponent system to a tonic opponent system of on-centre cells as purity increases. Detection and chromatic discrimination thresholds coincide only for long and short wavelengths of high purity, whereas they differ for mid-spectral lights. Different cell types may thus support detection and discrimination with different stimuli. With chromatic scaling of surface colours on the other hand, when stimuli are darker than an adaptation field still other cell types are needed. We demonstrate that it is possible, from a combination of on- and off-opponent cells, to reconstruct a uniform colour space, using summed outputs of cells with the same cone combination and vector addition for cells with different combinations. Different hues are represented by opponent cells with inputs from different cone types, the hue percept being related to the ratio of the activities of these cell systems.

Seeing red primes tomato: evidence for comparable priming from colour and colour name primes to semantically related word targets.

PubMed

Nijboer, Tanja C W; van Zandvoort, Martine J E; de Haan, Edward H F

2006-12-01

There is ample evidence that an independent processing stream exists that subserves the perception and appreciation of colour. Neurophysiological research has identified separate brain mechanisms for the processing of wavelength and colour, and neuropsychological studies have revealed selective colour disorders, such as achromatopsia, colour agnosia, and colour anomia. The aim of the present study is to investigate whether the perception of colour may, despite its independent processing, influence other cognitive functions. Specifically, we investigate the possibility that the perception of a colour influences higher order processes such as the activation of semantically related concepts. We designed an associative priming task involving a colour prime (e.g. a red patch or the word RED) and a lexical decision response to a semantically related ('tomato' vs. 'timato') or unrelated ('grass' vs. 'griss') word target. The results of this experiment indicate that there is comparable facilitation of accessing colour-related semantics through the perception of a colour or the reading of a colour name. This suggests that colour has a direct effect on higher order level, cognitive processing. These results are discussed in terms of current models of colour processing.

Effects of colour on preview search: anticipatory and inhibitory biases for colour.

PubMed

Braithwaite, Jason J; Humphreys, Glyn W; Hodsoll, John

2004-01-01

Two experiments are reported examining the effects of colour grouping, colour change and target colour foreknowledge under preview search conditions (Watson and Humphreys, 1997). In Experiment 1 we manipulated the colour homogeneity of the old items at initial presentation, and the colour these items subsequently changed into. In all cases participants knew the colour of the target. We found that when the old items changed into the same colour as the new search set, search performance was affected. In Experiment 2 participants did not know the colour of the target. Here we found evidence for a negative colour-based carry-over effect that slowed search for new targets carrying the colour of the old items. This occurred even when the old items changed their original colour and the new target was a singleton. Collectively the results suggest an important role for both colour grouping and colour-based inhibition in the successful rejection of old distractors. The consequence of this, however, is that new stimuli that may carry the critical attribute may take longer to detect. We discuss the results in relation to prior 'feature-blind' accounts of preview effects on visual search.

Influence of drug colour on perceived drug effects and efficacy.

PubMed

Tao, Da; Wang, Tieyan; Wang, Tieshan; Qu, Xingda

2018-02-01

A drug's physical characteristics, such as colour, could be factors influencing its therapeutic effects. It is not well understood whether people's expectations on drug effects and efficacy are affected by colour, especially among Chinese population. This study was conducted to examine people's expectations on drug effects and efficacy on the basis of drug colour, and to reveal possible gender differences in colour-related drug expectations. Participants (n = 224) were asked to classify seven single-coloured and six two-coloured capsules into one of four categories of drug effects, and to indicate the strength of drug efficacy. It is found that all the coloured capsules yielded non-chance distributions in classifications of drug effects, with six single-coloured and four two-coloured capsules associated with specific drug effects. Colour also conveyed differential strengths of drug efficacy in general and in relation to specific drug effects. There were gender differences in drug expectations for some colours and colour combinations. Practitioner Summary: Drug colour was found to have impacts on perceived drug effects and efficacy. The findings from the present study can be used by ergonomics practitioners to design appropriate drug colours in support of drug differentiation, therapeutic effects and medication adherence.

Volatile composition and sensory quality of Spanish pomegranates (Punica granatum L.).

PubMed

Calín-Sánchez, Angel; Martínez, Juan J; Vázquez-Araújo, Laura; Burló, Francisco; Melgarejo, Pablo; Carbonell-Barrachina, Angel A

2011-02-01

Pomegranate is highly valued for its health-promoting effects. Fruits of nine pomegranate cultivars were analysed for volatile compounds, antioxidant activity and quality parameters, including maturity index and CIEL*a*b* colour. Volatile compounds were isolated from fresh juices using hydrodistillation; extracts were analysed using gas chromatography/mass spectrometry. Fruit colour was influenced by cultivar and grouping of cultivars according to their taste (sweet, sour-sweet or sour), with sweet fruits having more intense red colour and higher lightness values. A total of 18 compounds were found in pomegranate aroma profiles, including monoterpenes, aldehydes, alcohols, monoterpenoids and linear hydrocarbons. The most abundant compound were trans-2-hexenal, 3-carene, α-terpinene and α-terpineol. The total concentration of volatiles ranged from 1.7 to 10.9 g kg(-1) . Overall consumer liking of pomegranate juices was associated with the presence of monoterpenes such as α-pinene, β-pinene, β-myrcene, limonene and γ-terpinene. The presence of aldehydes such as hexanol, hexanal and cis-3-hexenol was correlated with poor overall consumer liking. Fruits from the cultivar Mollar de Elche 2 were those most suited for juice processing because they had the highest total concentration of volatiles, which was related to high overall consumer liking, intense and acceptable fresh pomegranate odour and flavour (high scores of satisfaction degree), medium intensity of red colour and low sourness. 2010 Society of Chemical Industry.

Extraction and analysis of carotenoids from the New Zealand sea urchin Evechinus chloroticus gonads.

PubMed

Garama, Daniel; Bremer, Phil; Carne, Alan

2012-01-01

Sea urchin gonad (roe) is a highly valued food in Japan and North America. Gonad price is strongly influenced by quality, with appearance, especially colour being a major determinant. Previous attempts to extract a carotenoid profile from the New Zealand sea urchin species Evechinus chloroticus have been challenging due to the large amount of lipid present in the gonad. A carotenoid extraction and high performance liquid chromatography (HPLC) analysis method was developed to reduce lipid contamination by incorporating a saponification and lipid cold precipitation in the extraction procedure. This method enabled greater carotenoid purity and enhanced analysis by HPLC. Echinenone was found to be the main carotenoid present in all E. chloroticus gonads. Dark coloured gonads contained higher levels of fucoxanthin/fucoxanthinol, β-carotene and xanthophylls such as astaxanthin and canthaxanthin. This information on the modification and deposition of carotenoids will help in the development of diets to enhance gonad colour.

An odorant congruent with a colour cue is selectively perceived in an odour mixture.

PubMed

Arao, Mari; Suzuki, Maya; Katayama, Jun'ich; Akihiro, Yagi

2012-01-01

Odour identification can be influenced by colour cues. This study examined the mechanism underlying this colour context effect. We hypothesised that a specific odour component congruent with a colour would be selectively perceived in preference to another odour component in a binary odour mixture. We used a ratio estimation method under two colour conditions, a binary odour mixture (experiment 1) and single chemicals presented individually (experiment 2). Each colour was congruent with one of the odour components. Participants judged the perceived mixture ratio in each odour container on which a colour patch was pasted. An influence of colour was not observed when the odour stimulus did not contain the odour component congruent with the colour (experiment 2); however, the odour component congruent with the colour was perceived as more dominant when the odour stimulus did contain the colour-congruent odorant (experiment 1). This pattern indicates that a colour-congruent odour component is selectively perceived in an odour mixture. This finding suggests that colours can enhance the perceptual representation of the colour-associated component in an odour mixture.

Colour in digital pathology: a review.

PubMed

Clarke, Emily L; Treanor, Darren

2017-01-01

Colour is central to the practice of pathology because of the use of coloured histochemical and immunohistochemical stains to visualize tissue features. Our reliance upon histochemical stains and light microscopy has evolved alongside a wide variation in slide colour, with little investigation into the implications of colour variation. However, the introduction of the digital microscope and whole-slide imaging has highlighted the need for further understanding and control of colour. This is because the digitization process itself introduces further colour variation which may affect diagnosis, and image analysis algorithms often use colour or intensity measures to detect or measure tissue features. The US Food and Drug Administration have released recent guidance stating the need to develop a method of controlling colour reproduction throughout the digitization process in whole-slide imaging for primary diagnostic use. This comprehensive review introduces applied basic colour physics and colour interpretation by the human visual system, before discussing the importance of colour in pathology. The process of colour calibration and its application to pathology are also included, as well as a summary of the current guidelines and recommendations regarding colour in digital pathology. © 2016 John Wiley & Sons Ltd.

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

The GhTT2_A07 gene is linked to the brown colour and natural flame retardancy phenotypes of Lc1 cotton (Gossypium hirsutum L.) fibres

PubMed Central

Hinchliffe, Doug J.; Condon, Brian D.; Thyssen, Gregory; Naoumkina, Marina; Madison, Crista A.; Reynolds, Michael; Delhom, Christopher D.; Fang, David D.; Li, Ping; McCarty, Jack

2016-01-01

Some naturally coloured brown cotton fibres from accessions of Gossypium hirsutum L. can be used to make textiles with enhanced flame retardancy (FR). Several independent brown fibre loci have been identified and mapped to chromosomes, but the underlying genes have not yet been identified, and the mechanism of lint fibre FR is not yet fully understood. In this study, we show that both the brown colour and enhanced FR of the Lc1 lint colour locus are linked to a 1.4Mb inversion on chromosome A07 that is immediately upstream of a gene with similarity to Arabidopsis TRANSPARENT TESTA 2 (TT2). As a result of the alternative upstream sequence, the transcription factor GhTT2_A07 is highly up-regulated in developing fibres. In turn, genes in the phenylpropanoid metabolic pathway are activated, leading to biosynthesis of proanthocyanidins and accumulation of inorganic elements. We show that enhanced FR and anthocyanin precursors appear in developing brown fibres well before the brown colour is detectible, demonstrating for the first time that the polymerized proanthocyanidins that constitute the brown colour are not the source of enhanced FR. Identifying the particular colourless metabolite that provides Lc1 cotton with enhanced FR could help minimize the use of synthetic chemical flame retardant additives in textiles. PMID:27567364

Site-directed mutagenesis of firefly luciferase: implication of conserved residue(s) in bioluminescence emission spectra among firefly luciferases.

PubMed

Tafreshi, Narges Kh; Sadeghizadeh, Majid; Emamzadeh, Rahman; Ranjbar, Bijan; Naderi-Manesh, Hossein; Hosseinkhani, Saman

2008-05-15

The bioluminescence colours of firefly luciferases are determined by assay conditions and luciferase structure. Owing to red light having lower energy than green light and being less absorbed by biological tissues, red-emitting luciferases have been considered as useful reporters in imaging technology. A set of red-emitting mutants of Lampyris turkestanicus (Iranian firefly) luciferase has been made by site-directed mutagenesis. Among different beetle luciferases, those from Phrixothrix (railroad worm) emit either green or red bioluminescence colours naturally. By substitution of three specific amino acids using site-specific mutagenesis in a green-emitting luciferase (from L. turkestanicus), the colour of emitted light was changed to red concomitant with decreasing decay rate. Different specific mutations (H245N, S284T and H431Y) led to changes in the bioluminescence colour. Meanwhile, the luciferase reaction took place with relative retention of its basic kinetic properties such as K(m) and relative activity. Structural comparison of the native and mutant luciferases using intrinsic fluorescence, far-UV CD spectra and homology modelling revealed a significant conformational change in mutant forms. A change in the colour of emitted light indicates the critical role of these conserved residues in bioluminescence colour determination among firefly luciferases. Relatively high specific activity and emission of red light might make these mutants suitable as reporters for the study of gene expression and bioluminescence imaging.

An integrated anaerobic digestion and UV photocatalytic treatment of distillery wastewater.

PubMed

Apollo, Seth; Onyango, Maurice S; Ochieng, Aoyi

2013-10-15

Anaerobic up-flow fixed bed reactor and annular photocatalytic reactor were used to study the efficiency of integrated anaerobic digestion (AD) and ultraviolet (UV) photodegradation of real distillery effluent and raw molasses wastewater (MWW). It was found that UV photodegradation as a stand-alone technique achieved colour removal of 54% and 69% for the distillery and MWW, respectively, with a COD reduction of <20% and a negligible BOD reduction. On the other hand, AD as a single treatment technique was found to be effective in COD and BOD reduction with efficiencies of above 75% and 85%, respectively, for both wastewater samples. However, the AD achieved low colour removal efficiency, with an increase in colour intensity of 13% recorded when treating MWW while a colour removal of 51% was achieved for the distillery effluent. The application of UV photodegradation as a pre-treatment method to the AD process reduced the COD removal and biogas production efficiency. However, an integration in which UV photodegradation was employed as a post-treatment to the AD process achieved high COD removal of above 85% for both wastewater samples, and colour removal of 88% for the distillery effluent. Thus, photodegradation can be employed as a post-treatment technique to an AD system treating distillery effluent for complete removal of the biorecalcitrant and colour imparting compounds. Copyright © 2013 Elsevier B.V. All rights reserved.

Lethal visceral traumatic injuries secondary to child abuse: a case of practical application of autopsy, radiological and microscopic studies.

PubMed

Dedouit, Fabrice; Mallinger, Béatrice; Guilbeau-Frugier, Céline; Rougé, Daniel; Rousseau, Hervé; Telmon, Norbert

2011-03-20

A 3-year-old boy child died at home. The circumstances of death appeared unclear to the police investigators and a medicolegal autopsy was carried out. External examination revealed diffuse ecchymoses of varying colours. Postmortem imaging using plain X-rays and multislice computed tomography (MSCT) was performed prior to autopsy and pathological study. These investigations revealed fractures at the posterior arch of the ninth left rib. No cerebral and pericerebral traumatic lesions were diagnosed. In the abdomen, haemoperitoneum and pneumoperitoneum secondary to duodenal perforation and liver laceration were observed. At autopsy, a complete pancreatic fracture and duodenal transection were noted, accounting for the MSCT appearance. Furthermore, autopsy revealed the presence of bilateral intramuscular intercostal haemorrhages and a fracture of the eighth left rib at its posterior arch. This case report illustrates the valuable assistance rendered by MSCT as well as its limitations in diagnosing abuse when a child dies in unclear circumstances. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Colouring in the "black-box": Alternative renderings of scientific visualisations in two comic book cosmologies.

PubMed

Locke, Simon

2013-04-01

Two somewhat contrasting views of public uses of scientific visualisations argue that they are "black-boxed" with meaning given by the scientific community or they are "polysemic" with meaning given by the context of presentation. This paper argues that whether they are treated as black-boxed or not and in what manner this is done is itself part of the meaning given by context. Thus, "black-boxing" is done not only by scientists but also by members of the public. The argument is illustrated by reference to two recent comic books, Dave Sim's Cerebus and Alan Moore's Promethea, in which the authors present cosmological visions of the universe using scientific visualisations to create a sense of realism. From analysis of their use of images of planet Earth and the human foetus it is argued that, although the images are black-boxed, the authors re-work them aesthetically to suit their specific moral and cosmological views.

Cellulose, hemicelluloses, lignin and ash content of some organic materials and their suitability for use as paper pulp supplements.

PubMed

Ververis, C; Georghiou, K; Danielidis, D; Hatzinikolaou, D G; Santas, P; Santas, R; Corleti, V

2007-01-01

Freshwater algal biomass and orange and lemon peels were assessed as tissue paper pulp supplements. Cellulose and hemicellulose contents of algal biomass were 7.1% and 16.3%, respectively, whereas for citrus peels cellulose content ranged from 12.7% to 13.6% and hemicellulose from 5.3% to 6.1%. For all materials, lignin and ash content was 2% or lower, rendering them suitable for use as paper pulp supplements. The addition of algal biomass to paper pulp increased its mechanical strength significantly. However, brightness was adversely affected by chlorophyll. The addition of citrus peels in paper pulp had no effect on breaking length, increased bursting strength and decreased tearing resistance. Brightness was negatively affected at proportions of 10%, because citrus peel particles behave as coloured pigments. The cost of both materials is about 45% lower than that of conventional pulp, resulting in a 0.9-4.5% reduction in final paper price upon their addition to the pulp.

The colour wheels of art, perception, science and physiology

NASA Astrophysics Data System (ADS)

Harkness, Nick

2006-06-01

Colour is not the domain of any one discipline be it art, philosophy, psychology or science. Each discipline has its own colour wheel and this presentation examines the origins and philosophies behind the colour circles of Art, Perception, Science and Physiology (after image) with reference to Aristotle, Robert Boyle, Leonardo da Vinci, Goethe, Ewald Hering and Albert Munsell. The paper analyses and discusses the differences between the four colour wheels using the Natural Colour System® notation as the reference for hue (the position of colours within each of the colour wheels). Examination of the colour wheels shows the dominance of blue in the wheels of art, science and physiology particularly at the expense of green. This paper does not consider the three-dimensionality of colour space its goal was to review the hue of a colour with regard to its position on the respective colour wheels.

IceT users' guide and reference.

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

Moreland, Kenneth D.

2011-01-01

The Image Composition Engine for Tiles (IceT) is a high-performance sort-last parallel rendering library. In addition to providing accelerated rendering for a standard display, IceT provides the unique ability to generate images for tiled displays. The overall resolution of the display may be several times larger than any viewport that may be rendered by a single machine. This document is an overview of the user interface to IceT.

Colour categories are reflected in sensory stages of colour perception when stimulus issues are resolved.

PubMed

Forder, Lewis; He, Xun; Franklin, Anna

2017-01-01

Debate exists about the time course of the effect of colour categories on visual processing. We investigated the effect of colour categories for two groups who differed in whether they categorised a blue-green boundary colour as the same- or different-category to a reliably-named blue colour and a reliably-named green colour. Colour differences were equated in just-noticeable differences to be equally discriminable. We analysed event-related potentials for these colours elicited on a passive visual oddball task and investigated the time course of categorical effects on colour processing. Support for category effects was found 100 ms after stimulus onset, and over frontal sites around 250 ms, suggesting that colour naming affects both early sensory and later stages of chromatic processing.

Colour categories are reflected in sensory stages of colour perception when stimulus issues are resolved

PubMed Central

He, Xun; Franklin, Anna

2017-01-01

Debate exists about the time course of the effect of colour categories on visual processing. We investigated the effect of colour categories for two groups who differed in whether they categorised a blue-green boundary colour as the same- or different-category to a reliably-named blue colour and a reliably-named green colour. Colour differences were equated in just-noticeable differences to be equally discriminable. We analysed event-related potentials for these colours elicited on a passive visual oddball task and investigated the time course of categorical effects on colour processing. Support for category effects was found 100 ms after stimulus onset, and over frontal sites around 250 ms, suggesting that colour naming affects both early sensory and later stages of chromatic processing. PMID:28542426

Image simulation and assessment of the colour and spatial capabilities of the Colour and Stereo Surface Imaging System (CaSSIS) on the ExoMars Trace Gas Orbiter

USGS Publications Warehouse

Tornabene, Livio L.; Seelos, Frank P.; Pommerol, Antoine; Thomas, Nicolas; Caudill, Christy M.; Becerra, Patricio; Bridges, John C.; Byrne, Shane; Cardinale, Marco; Chojnacki, Matthew; Conway, Susan J.; Cremonese, Gabriele; Dundas, Colin M.; El-Maarry, M. R.; Fernando, Jennifer; Hansen, Candice J.; Hansen, Kayle; Harrison, Tanya N.; Henson, Rachel; Marinangeli, Lucia; McEwen, Alfred S.; Pajola, Maurizio; Sutton, Sarah S.; Wray, James J.

2018-01-01

This study aims to assess the spatial and visible/near-infrared (VNIR) colour/spectral capabilities of the 4-band Colour and Stereo Surface Imaging System (CaSSIS) aboard the ExoMars 2016 Trace Grace Orbiter (TGO). The instrument response functions for the CaSSIS imager was used to resample spectral libraries, modelled spectra and to construct spectrally (i.e., in I/F space) and spatially consistent simulated CaSSIS image cubes of various key sites of interest and for ongoing scientific investigations on Mars. Coordinated datasets from Mars Reconnaissance Orbiter (MRO) are ideal, and specifically used for simulating CaSSIS. The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) provides colour information, while the Context Imager (CTX), and in a few cases the High-Resolution Imaging Science Experiment (HiRISE), provides the complementary spatial information at the resampled CaSSIS unbinned/unsummed pixel resolution (4.6 m/pixel from a 400-km altitude). The methodology used herein employs a Gram-Schmidt spectral sharpening algorithm to combine the ∼18–36 m/pixel CRISM-derived CaSSIS colours with I/F images primarily derived from oversampled CTX images. One hundred and eighty-one simulated CaSSIS 4-colour image cubes (at 18–36 m/pixel) were generated (including one of Phobos) based on CRISM data. From these, thirty-three “fully”-simulated image cubes of thirty unique locations on Mars (i.e., with 4 colour bands at 4.6 m/pixel) were made. All simulated image cubes were used to test both the colour capabilities of CaSSIS by producing standard colour RGB images, colour band ratio composites (CBRCs) and spectral parameters. Simulated CaSSIS CBRCs demonstrated that CaSSIS will be able to readily isolate signatures related to ferrous (Fe2+) iron- and ferric (Fe3+) iron-bearing deposits on the surface of Mars, ices and atmospheric phenomena. Despite the lower spatial resolution of CaSSIS when compared to HiRISE, the results of this work demonstrate that CaSSIS will not only compliment HiRISE-scale studies of various geological and seasonal phenomena, it will also enhance them by providing additional colour and geologic context through its wider and longer full-colour coverage (∼9.4×50">∼9.4×50∼9.4×50 km), and its increased sensitivity to iron-bearing materials from its two IR bands (RED and NIR). In a few examples, subtle surface changes that were not easily detected by HiRISE were identified in the simulated CaSSIS images. This study also demonstrates the utility of the Gram-Schmidt spectral pan-sharpening technique to extend VNIR colour/spectral capabilities from a lower spatial resolution colour/spectral dataset to a single-band or panchromatic image greyscale image with higher resolution. These higher resolution colour products (simulated CaSSIS or otherwise) are useful as means to extend both geologic context and mapping of datasets with coarser spatial resolutions. The results of this study indicate that the TGO mission objectives, as well as the instrument-specific mission objectives, will be achievable with CaSSIS.

Colour is more than hue: preferences for compiled colour traits in the stingless bees Melipona mondury and M. quadrifasciata.

PubMed

Koethe, Sebastian; Bossems, Jessica; Dyer, Adrian G; Lunau, Klaus

2016-10-01

The colour vision of bees has been extensively analysed in honeybees and bumblebees, but few studies consider the visual perception of stingless bees (Meliponini). In a five-stage experiment the preference for colour intensity and purity, and the preference for the dominant wavelength were tested by presenting four colour stimuli in each test to freely flying experienced workers of two stingless bee species, Melipona mondury and Melipona quadrifasciata. The results with bee-blue, bee-UV-blue and bee-green colours offered in four combinations of varying colour intensity and purity suggest a complex interaction between these colour traits for the determination of colour choice. Specifically, M. mondury preferred bee-UV-blue colours over bee-green, bee-blue and bee-blue-green colours while M. quadrifasciata preferred bee-green colour stimuli. Moreover in M. mondury the preferences were different if the background colour was changed from grey to green. There was a significant difference between species where M. mondury preferred UV-reflecting over UV-absorbing bee-blue-green colour stimuli, whereas M. quadrifasciata showed an opposite preference. The different colour preferences of the free flying bees in identical conditions may be caused by the bees' experience with natural flowers precedent to the choice tests, suggesting reward partitioning between species.

Colour in flux: describing and printing colour in art

NASA Astrophysics Data System (ADS)

Parraman, Carinna

2008-01-01

This presentation will describe artists, practitioners and scientists, who were interested in developing a deeper psychological, emotional and practical understanding of the human visual system who were working with wavelength, paint and other materials. From a selection of prints at The Prints and Drawings Department at Tate London, the presentation will refer to artists who were motivated by issues relating to how colour pigment was mixed and printed, to interrogate and explain colour perception and colour science, and in art, how artists have used colour to challenge the viewer and how a viewer might describe their experience of colour. The title Colour in Flux refers, not only to the perceptual effect of the juxtaposition of one colour pigment with another, but also to the changes and challenges for the print industry. In the light of screenprinted examples from the 60s and 70s, the presentation will discuss 21 st century ideas on colour and how these notions have informed the Centre for Fine Print Research's (CFPR) practical research in colour printing. The latter part of this presentation will discuss the implications for the need to change methods in mixing inks that moves away from existing colour spaces, from non intuitive colour mixing to bespoke ink sets, colour mixing approaches and colour mixing methods that are not reliant on RGB or CMYK.

Rock images classification by using deep convolution neural network

NASA Astrophysics Data System (ADS)

Cheng, Guojian; Guo, Wenhui

2017-08-01

Granularity analysis is one of the most essential issues in authenticate under microscope. To improve the efficiency and accuracy of traditional manual work, an convolutional neural network based method is proposed for granularity analysis from thin section image, which chooses and extracts features from image samples while build classifier to recognize granularity of input image samples. 4800 samples from Ordos basin are used for experiments under colour spaces of HSV, YCbCr and RGB respectively. On the test dataset, the correct rate in RGB colour space is 98.5%, and it is believable in HSV and YCbCr colour space. The results show that the convolution neural network can classify the rock images with high reliability.

Do bees like Van Gogh's Sunflowers?

NASA Astrophysics Data System (ADS)

Chittka, Lars; Walker, Julian

2006-06-01

Flower colours have evolved over 100 million years to address the colour vision of their bee pollinators. In a much more rapid process, cultural (and horticultural) evolution has produced images of flowers that stimulate aesthetic responses in human observers. The colour vision and analysis of visual patterns differ in several respects between humans and bees. Here, a behavioural ecologist and an installation artist present bumblebees with reproductions of paintings highly appreciated in Western society, such as Van Gogh's Sunflowers. We use this unconventional approach in the hope to raise awareness for between-species differences in visual perception, and to provoke thinking about the implications of biology in human aesthetics and the relationship between object representation and its biological connotations.

Narrow-band filters for ocean colour imager

NASA Astrophysics Data System (ADS)

Krol, Hélène; Chazallet, Frédéric; Archer, Julien; Kirchgessner, Laurent; Torricini, Didier; Grèzes-Besset, Catherine

2017-11-01

During the last few years, the evolution of deposition technologies of optical thin films coatings and associated in-situ monitoring methods enables us today to successfully answer the increasingly request of space systems for Earth observation. Geostationary satellite COMS-1 (Communication, Ocean, Meteorological Satellite-1) of Astrium has the role of ensuring meteorological observation as well as monitoring of the oceans. It is equipped with a colour imager to observe the marine ecosystem through 8 bands in the visible spectrum with a ground resolution of 500m. For that, this very high technology instrument is constituted with a filters wheel in front of the oceanic colour imager with 8 narrow band filters carried out and qualified by Cilas.

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

The role of pollinators in maintaining variation in flower colour in the Rocky Mountain columbine, Aquilegia coerulea

PubMed Central

Thairu, Margaret W.; Brunet, Johanne

2015-01-01

Background and Aims Flower colour varies within and among populations of the Rocky Mountain columbine, Aquilegia coerulea, in conjunction with the abundance of its two major pollinators, hawkmoths and bumble-bees. This study seeks to understand whether the choice of flower colour by these major pollinators can help explain the variation in flower colour observed in A. coerulea populations. Methods Dual choice assays and experimental arrays of blue and white flowers were used to determine the preference of hawkmoths and bumble-bees for flower colour. A test was made to determine whether a differential preference for flower colour, with bumble-bees preferring blue and hawkmoths white flowers, could explain the variation in flower colour. Whether a single pollinator could maintain a flower colour polymorphism was examined by testing to see if preference for a flower colour varied between day and dusk for hawkmoths and whether bumble-bees preferred novel or rare flower colour morphs. Key Results Hawkmoths preferred blue flowers under both day and dusk light conditions. Naïve bumble-bees preferred blue flowers but quickly learned to forage randomly on the two colour morphs when similar rewards were presented in the flowers. Bees quickly learned to associate a flower colour with a pollen reward. Prior experience affected the choice of flower colour by bees, but they did not preferentially visit novel flower colours or rare or common colour morphs. Conclusions Differences in flower colour preference between the two major pollinators could not explain the variation in flower colour observed in A. coerulea. The preference of hawkmoths for flower colour did not change between day and dusk, and bumble-bees did not prefer a novel or a rare flower colour morph. The data therefore suggest that factors other than pollinators may be more likely to affect the flower colour variation observed in A. coerulea. PMID:25808657

Looking at anything that is green when hearing "frog": how object surface colour and stored object colour knowledge influence language-mediated overt attention.

PubMed

Huettig, Falk; Altmann, Gerry T M

2011-01-01

Three eye-tracking experiments investigated the influence of stored colour knowledge, perceived surface colour, and conceptual category of visual objects on language-mediated overt attention. Participants heard spoken target words whose concepts are associated with a diagnostic colour (e.g., "spinach"; spinach is typically green) while their eye movements were monitored to (a) objects associated with a diagnostic colour but presented in black and white (e.g., a black-and-white line drawing of a frog), (b) objects associated with a diagnostic colour but presented in an appropriate but atypical colour (e.g., a colour photograph of a yellow frog), and (c) objects not associated with a diagnostic colour but presented in the diagnostic colour of the target concept (e.g., a green blouse; blouses are not typically green). We observed that colour-mediated shifts in overt attention are primarily due to the perceived surface attributes of the visual objects rather than stored knowledge about the typical colour of the object. In addition our data reveal that conceptual category information is the primary determinant of overt attention if both conceptual category and surface colour competitors are copresent in the visual environment.

Luminescent zinc(ii) and copper(i) complexes for high-performance solution-processed monochromic and white organic light-emitting devices.

PubMed

Cheng, Gang; So, Gary Kwok-Ming; To, Wai-Pong; Chen, Yong; Kwok, Chi-Chung; Ma, Chensheng; Guan, Xiangguo; Chang, Xiaoyong; Kwok, Wai-Ming; Che, Chi-Ming

2015-08-01

The synthesis and spectroscopic properties of luminescent tetranuclear zinc(ii) complexes of substituted 7-azaindoles and a series of luminescent copper(i) complexes containing 7,8-bis(diphenylphosphino)-7,8-dicarba- nido -undecaborate ligand are described. These complexes are stable towards air and moisture. Thin film samples of the luminescent copper(i) complexes in 2,6-dicarbazolo-1,5-pyridine and zinc(ii) complexes in poly(methyl methacrylate) showed emission quantum yields of up to 0.60 (for Cu-3 ) and 0.96 (for Zn-1 ), respectively. Their photophysical properties were examined by ultrafast time-resolved emission spectroscopy, temperature dependent emission lifetime measurements and density functional theory calculations. Monochromic blue and orange solution-processed OLEDs with these Zn(ii) and Cu(i) complexes as light-emitting dopants have been fabricated, respectively. Maximum external quantum efficiency (EQE) of 5.55% and Commission Internationale de l'Eclairage (CIE) coordinates of (0.16, 0.19) were accomplished with the optimized Zn-1 -OLED while these values were, respectively 15.64% and (0.48, 0.51) for the optimized Cu-3 -OLED. Solution-processed white OLEDs having maximum EQE of 6.88%, CIE coordinates of (0.42, 0.44), and colour rendering index of 81 were fabricated by using these luminescent Zn(ii) and Cu(i) complexes as blue and orange light-emitting dopant materials, respectively.

A Bayesian Model of the Memory Colour Effect.

PubMed

Witzel, Christoph; Olkkonen, Maria; Gegenfurtner, Karl R

2018-01-01

According to the memory colour effect, the colour of a colour-diagnostic object is not perceived independently of the object itself. Instead, it has been shown through an achromatic adjustment method that colour-diagnostic objects still appear slightly in their typical colour, even when they are colourimetrically grey. Bayesian models provide a promising approach to capture the effect of prior knowledge on colour perception and to link these effects to more general effects of cue integration. Here, we model memory colour effects using prior knowledge about typical colours as priors for the grey adjustments in a Bayesian model. This simple model does not involve any fitting of free parameters. The Bayesian model roughly captured the magnitude of the measured memory colour effect for photographs of objects. To some extent, the model predicted observed differences in memory colour effects across objects. The model could not account for the differences in memory colour effects across different levels of realism in the object images. The Bayesian model provides a particularly simple account of memory colour effects, capturing some of the multiple sources of variation of these effects.

A Bayesian Model of the Memory Colour Effect

PubMed Central

Olkkonen, Maria; Gegenfurtner, Karl R.

2018-01-01

According to the memory colour effect, the colour of a colour-diagnostic object is not perceived independently of the object itself. Instead, it has been shown through an achromatic adjustment method that colour-diagnostic objects still appear slightly in their typical colour, even when they are colourimetrically grey. Bayesian models provide a promising approach to capture the effect of prior knowledge on colour perception and to link these effects to more general effects of cue integration. Here, we model memory colour effects using prior knowledge about typical colours as priors for the grey adjustments in a Bayesian model. This simple model does not involve any fitting of free parameters. The Bayesian model roughly captured the magnitude of the measured memory colour effect for photographs of objects. To some extent, the model predicted observed differences in memory colour effects across objects. The model could not account for the differences in memory colour effects across different levels of realism in the object images. The Bayesian model provides a particularly simple account of memory colour effects, capturing some of the multiple sources of variation of these effects. PMID:29760874

16 CFR § 1610.39 - Shipments under section 11(c) of the Act.

Code of Federal Regulations, 2013 CFR

2013-01-01

... finished by the undersigned or by a duly authorized agent so as to render them not so highly flammable...§ 1610.39 Section § 1610.39 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS... finishing or processing to render them not so highly flammable as to be dangerous when worn by individuals...

16 CFR 1611.39 - Shipments under section 11(c) of the act.

Code of Federal Regulations, 2011 CFR

2011-01-01

... undersigned or by a duly authorized agent so as to render them not so highly flammable under the provisions of.... 1611.39 Section 1611.39 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT... processing to render them not so highly flammable as to be dangerous when worn by individuals, shall contain...

16 CFR 1611.39 - Shipments under section 11(c) of the act.

Code of Federal Regulations, 2014 CFR

2014-01-01

... undersigned or by a duly authorized agent so as to render them not so highly flammable under the provisions of.... 1611.39 Section 1611.39 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT... processing to render them not so highly flammable as to be dangerous when worn by individuals, shall contain...

16 CFR 1611.39 - Shipments under section 11(c) of the act.

Code of Federal Regulations, 2012 CFR

2012-01-01

... undersigned or by a duly authorized agent so as to render them not so highly flammable under the provisions of.... 1611.39 Section 1611.39 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT... processing to render them not so highly flammable as to be dangerous when worn by individuals, shall contain...

Colour Coding of Maps for Colour Deficient Observers.

PubMed

Røise, Anne Kari; Kvitle, Anne Kristin; Green, Phil

2016-01-01

We evaluate the colour coding of a web map traffic information service based on profiles simulating colour vision deficiencies. Based on these simulations and principles for universal design, we propose adjustments of the existing colours creating more readable maps for the colour vision deficient observers.

Children's colour choices for completing drawings of affectively characterised topics.

PubMed

Burkitt, Esther; Barrett, Martyn; Davis, Alyson

2003-03-01

This study was designed to explore whether or not children systematically use particular colours when completing drawings of affectively characterised topics. Three hundred and thirty 4-11-year-old children were subdivided into three conditions, colouring in a drawing of a man, a dog, or a tree, respectively. The children completed two test sessions in counterbalanced order. In one session, children rated and ranked ten colours in order of preference. In the other session, children completed three colouring tasks in which they had to colour in three identical figures but which had been given different affective characterisations: a neutrally characterised figure, a figure characterised as nasty, and a figure characterised as nice. It was found that, in all age groups and for all topics, the children used their more preferred colours for the nice figures, their least preferred colours for the nasty figures, and colours rated intermediately for the neutral figures. It was also found that, in all age groups and for all topics, black tended to be the most frequently chosen colour for colouring in the drawings of the negatively characterised figures. By contrast, primary colours were predominantly selected for the neutral figure, while a wide range of mainly primary and secondary colours were chosen for colouring in the nice figure. These results suggest that children are able to alter systematically their use of colour during picture completion tasks in response to differential affective topic characterisations, and that even very young children are able to use colours symbolically.

Visualising fragrances through colours: the mediating role of emotions.

PubMed

Schifferstein, Hendrik N J; Tanudjaja, Inge

2004-01-01

To facilitate communication about fragrances, one can use the colours people tend to associate with their smells. We investigated to what extent odour-colour correspondences for fine fragrances can be accounted for by underlying emotional associations. Odour-colour matches and degree-of-fit judgments revealed that odours were matched to colours non-randomly. Matching colours differed mainly on blackness (brightness), and less on chromaticness (saturation) and hue. Furthermore, we found a consistent negative relationship between odour-colour degree-of-fit ratings and the difference between the odour scores and the colour scores on one of the emotion dimensions (pleasure). This suggests that emotional associations may partly underlie odour-colour correspondences.

The effect of coloured overlays and lenses on reading: a systematic review of the literature.

PubMed

Griffiths, Philip G; Taylor, Robert H; Henderson, Lisa M; Barrett, Brendan T

2016-09-01

There are many anecdotal claims and research reports that coloured lenses and overlays improve reading performance. Here we present the results of a systematic review of this literature and examine the quality of the evidence. We systematically reviewed the literature concerning the effect of coloured lenses or overlays on reading performance by searching the PsychInfo, Medline and Embase databases. This revealed 51 published items (containing 54 data sets). Given that different systems are in use for issuing coloured overlays or lenses, we reviewed the evidence under four separate system headings (Intuitive, Irlen, Harris/Chromagen and Other), classifying each published item using the Cochrane Risk of Bias tool. Although the different colour systems have been subjected to different amounts of scientific scrutiny, the results do not differ according to the system type, or whether the sample under investigation was classified as having visual stress (or a similarly defined condition), reading difficulty, or both. The majority of studies are subject to 'high' or 'uncertain' risk of bias in one or more key aspects of study design or outcome, with studies at lower risk from bias providing less support for the benefit of coloured lenses/overlays on reading ability. While many studies report improvements with coloured lenses, the effect size is generally small and/or similar to the improvement found with a placebo condition. We discuss the strengths and shortcomings of the published literature and, whilst acknowledging the difficulties associated with conducting trials of this type, offer some suggestions about how future trials might be conducted. Consistent with previous reviews and advice from several professional bodies, we conclude that the use of coloured lenses or overlays to ameliorate reading difficulties cannot be endorsed and that any benefits reported by individuals in clinical settings are likely to be the result of placebo, practice or Hawthorne effects. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

Psychophysical Evaluation of Congenital Colour Vision Deficiency: Discrimination between Protans and Deutans Using Mollon-Reffin’s Ellipses and the Farnsworth-Munsell 100-Hue Test

PubMed Central

Bento-Torres, Natáli Valim Oliver; Rodrigues, Anderson Raiol; Côrtes, Maria Izabel Tentes; Bonci, Daniela Maria de Oliveira; Ventura, Dora Fix

2016-01-01

We have used the Farnsworth-Munsell 100-hue (FM 100) test and Mollon-Reffin (MR) test to evaluate the colour vision of 93 subjects, 30.4 ± 9.7 years old, who had red-green congenital colour vision deficiencies. All subjects lived in Belém (State of Pará, Brazil) and were selected by the State of Pará Traffic Department. Selection criteria comprised the absence of visual dysfunctions other than Daltonism and no history of systemic diseases that could impair the visual system performance. Results from colour vision deficient were compared with those from 127 normal trichromats, 29.3 ± 10.3 years old. For the MR test, measurements were taken around five points of the CIE 1976 colour space, along 20 directions irradiating from each point, in order to determine with high-resolution the corresponding colour discrimination ellipses (MacAdam ellipses). Three parameters were used to compare results obtained from different subjects: diameter of circle with same ellipse area, ratio between ellipse’s long and short axes, and ellipse long axis angle. For the FM 100 test, the parameters were: logarithm of the total number of mistakes and positions of mistakes in the FM diagram. Data were also simultaneously analysed in two or three dimensions as well as by using multidimensional cluster analysis. For the MR test, Mollon-Reffin Ellipse #3 (u’ = 0.225, v’ = 0.415) discriminated more efficiently than the other four ellipses between protans and deutans once it provided larger angular difference in the colour space between protan and deutan confusion lines. The MR test was more sensitive than the FM 100 test. It separated individuals by dysfunctional groups with greater precision, provided a more sophisticated quantitative analysis, and its use is appropriate for a more refined evaluation of different phenotypes of red-green colour vision deficiencies. PMID:27101124

Second-order statistics of colour codes modulate transformations that effectuate varying degrees of scene invariance and illumination invariance.

PubMed

Mausfeld, Rainer; Andres, Johannes

2002-01-01

We argue, from an ethology-inspired perspective, that the internal concepts 'surface colours' and 'illumination colours' are part of the data format of two different representational primitives. Thus, the internal concept of 'colour' is not a unitary one but rather refers to two different types of 'data structure', each with its own proprietary types of parameters and relations. The relation of these representational structures is modulated by a class of parameterised transformations whose effects are mirrored in the idealised computational achievements of illumination invariance of colour codes, on the one hand, and scene invariance, on the other hand. Because the same characteristics of a light array reaching the eye can be physically produced in many different ways, the visual system, then, has to make an 'inference' whether a chromatic deviation of the space-averaged colour codes from the neutral point is due to a 'non-normal', ie chromatic, illumination or due to an imbalanced spectral reflectance composition. We provide evidence that the visual system uses second-order statistics of chromatic codes of a single view of a scene in order to modulate corresponding transformations. In our experiments we used centre surround configurations with inhomogeneous surrounds given by a random structure of overlapping circles, referred to as Seurat configurations. Each family of surrounds has a fixed space-average of colour codes, but differs with respect to the covariance matrix of colour codes of pixels that defines the chromatic variance along some chromatic axis and the covariance between luminance and chromatic channels. We found that dominant wavelengths of red-green equilibrium settings of the infield exhibited a stable and strong dependence on the chromatic variance of the surround. High variances resulted in a tendency towards 'scene invariance', low variances in a tendency towards 'illumination invariance' of the infield.

Psychophysical Evaluation of Congenital Colour Vision Deficiency: Discrimination between Protans and Deutans Using Mollon-Reffin's Ellipses and the Farnsworth-Munsell 100-Hue Test.

PubMed

Bento-Torres, Natáli Valim Oliver; Rodrigues, Anderson Raiol; Côrtes, Maria Izabel Tentes; Bonci, Daniela Maria de Oliveira; Ventura, Dora Fix; Silveira, Luiz Carlos de Lima

2016-01-01

We have used the Farnsworth-Munsell 100-hue (FM 100) test and Mollon-Reffin (MR) test to evaluate the colour vision of 93 subjects, 30.4 ± 9.7 years old, who had red-green congenital colour vision deficiencies. All subjects lived in Belém (State of Pará, Brazil) and were selected by the State of Pará Traffic Department. Selection criteria comprised the absence of visual dysfunctions other than Daltonism and no history of systemic diseases that could impair the visual system performance. Results from colour vision deficient were compared with those from 127 normal trichromats, 29.3 ± 10.3 years old. For the MR test, measurements were taken around five points of the CIE 1976 colour space, along 20 directions irradiating from each point, in order to determine with high-resolution the corresponding colour discrimination ellipses (MacAdam ellipses). Three parameters were used to compare results obtained from different subjects: diameter of circle with same ellipse area, ratio between ellipse's long and short axes, and ellipse long axis angle. For the FM 100 test, the parameters were: logarithm of the total number of mistakes and positions of mistakes in the FM diagram. Data were also simultaneously analysed in two or three dimensions as well as by using multidimensional cluster analysis. For the MR test, Mollon-Reffin Ellipse #3 (u' = 0.225, v' = 0.415) discriminated more efficiently than the other four ellipses between protans and deutans once it provided larger angular difference in the colour space between protan and deutan confusion lines. The MR test was more sensitive than the FM 100 test. It separated individuals by dysfunctional groups with greater precision, provided a more sophisticated quantitative analysis, and its use is appropriate for a more refined evaluation of different phenotypes of red-green colour vision deficiencies.

Hue-specific colour memory impairment in an individual with intact colour perception and colour naming.

PubMed

Jakobson, L S; Pearson, P M; Robertson, B

2008-01-15

Cases of hue-selective dyschomatopsias, together with the results of recent optical imaging studies [Xiao, Y., Casti, A. R. R., Xiao, J., & Kaplan, E. (2006). A spatially organized representation of colour in macaque primary visual cortex. Perception, 35, ECVP Abstract Supplement; Xiao, Y., Wang, Y., & Felleman, D. J. (2003). A spatially organized representation of colour in macaque cortical area V2. Nature, 421, 535-539], have provided support for the idea that different colours are processed in spatially distinct regions of extrastriate cortex. In the present report, we provide evidence suggesting that a similar, but distinct, map may exist for representations of colour in memory. This evidence comes from observations of a young woman (QP) who demonstrates an isolated deficit in colour memory secondary to a concussive episode. Despite having normal colour perception and colour naming skills, and above-average memory skills in other domains, QP's ability to recall visually encoded colour information over short retention intervals is dramatically impaired. Her long-term memory for colour and her colour imagery skills are also abnormal. Surprisingly, however, these impairments are not seen with all hues; specifically, her ability to remember or imagine blue shades is spared. This interesting case contributes to the literature suggesting that colour perception, naming, and memory can be clinically dissociated, and provides insights into the organization of colour information in memory.

Crocins with High Levels of Sugar Conjugation Contribute to the Yellow Colours of Early-Spring Flowering Crocus Tepals

PubMed Central

Rubio Moraga, Angela; Ahrazem, Oussama; Rambla, José Luis; Granell, Antonio; Gómez Gómez, Lourdes

2013-01-01

Crocus sativus is the source of saffron spice, the processed stigma which accumulates glucosylated apocarotenoids known as crocins. Crocins are found in the stigmas of other Crocuses, determining the colourations observed from pale yellow to dark red. By contrast, tepals in Crocus species display a wider diversity of colours which range from purple, blue, yellow to white. In this study, we investigated whether the contribution of crocins to colour extends from stigmas to the tepals of yellow Crocus species. Tepals from seven species were analysed by UPLC-PDA and ESI-Q-TOF-MS/MS revealing for the first time the presence of highly glucosylated crocins in this tissue. β-carotene was found to be the precursor of these crocins and some of them were found to contain rhamnose, never before reported. When crocin profiles from tepals were compared with those from stigmas, clear differences were found, including the presence of new apocarotenoids in stigmas. Furthermore, each species showed a characteristic profile which was not correlated with the phylogenetic relationship among species. While gene expression analysis in tepals of genes involved in carotenoid metabolism showed that phytoene synthase was a key enzyme in apocarotenoid biosynthesis in tepals. Expression of a crocetin glucosyltransferase, previously identified in saffron, was detected in all the samples. The presence of crocins in tepals is compatible with the role of chromophores to attract pollinators. The identification of tepals as new sources of crocins is of special interest given their wide range of applications in medicine, cosmetics and colouring industries. PMID:24058441

Pseudoisochromatic test plate colour representation dependence on printing technology

NASA Astrophysics Data System (ADS)

Luse, K.; Fomins, S.; Ozolinsh, M.

2012-08-01

The aim of the study is to determine best printing technology for creation of colour vision deficiency tests. Valid tests for protanopia and deuteranopia were created from perceived colour matching experiments from printed colour samples by colour deficient individuals. Calibrated EpsonStylus Pro 7800 printer for ink prints and Noritsu HD 3701 digital printer for photographic prints were used. Multispectral imagery (by tunable liquid crystal filters system CRI Nuance Vis 07) data analysis show that in case of ink prints, the measured pixel colour coordinate dispersion (in the CIExy colour diagram) of similar colour arrays is smaller than in case of photographic printing. The print quality in terms of colour coordinate dispersion for printing methods used is much higher than in case of commercially available colour vision deficiency tests.

Environmental and hormonal factors controlling reversible colour change in crab spiders.

PubMed

Llandres, Ana L; Figon, Florent; Christidès, Jean-Philippe; Mandon, Nicole; Casas, Jérôme

2013-10-15

Habitat heterogeneity that occurs within an individual's lifetime may favour the evolution of reversible plasticity. Colour reversibility has many different functions in animals, such as thermoregulation, crypsis through background matching and social interactions. However, the mechanisms underlying reversible colour changes are yet to be thoroughly investigated. This study aims to determine the environmental and hormonal factors underlying morphological colour changes in Thomisus onustus crab spiders and the biochemical metabolites produced during these changes. We quantified the dynamics of colour changes over time: spiders were kept in yellow and white containers under natural light conditions and their colour was measured over 15 days using a spectrophotometer. We also characterised the chemical metabolites of spiders changing to a yellow colour using HPLC. Hormonal control of colour change was investigated by injecting 20-hydroxyecdysone (20E) into spiders. We found that background colouration was a major environmental factor responsible for colour change in crab spiders: individuals presented with white and yellow backgrounds changed to white and yellow colours, respectively. An ommochrome precursor, 3-OH-kynurenine, was the main pigment responsible for yellow colour. Spiders injected with 20E displayed a similar rate of change towards yellow colouration as spiders kept in yellow containers and exposed to natural sunlight. This study demonstrates novel hormonal manipulations that are capable of inducing reversible colour change.

Exposure of Polish children to Southampton food colours.

PubMed

Gajda-Wyrębek, J; Kuźma, K; Świtka, A; Jarecka, J; Beresińska, M; Postupolski, J

2017-01-01

A study published in 2007 showed that the intake of six food colours (the so-called 'Southampton colours') may have an adverse effect on activity and attention in children. The present study set out to assess the exposure of Polish children (3 and 8-9 years old, n = 149) to six of the target colours. Two methods were used to evaluate colour consumption by children: scenario 1 using the maximum permitted levels (MPLs) and actual food consumption data; and scenario 2 using the actual levels in food and actual food consumption data. The data on the actual consumption of food containing the colours was collected using a 7-day questionnaire survey. The results of laboratory analysis of food consumed by children provided data on the actual levels of the colours in food. Consumption of the colours estimated by scenario 1 in any case did not exceed the acceptable daily intakes (ADIs) of the colours in both age groups of children. For more refined colour intake (scenario 2), isolated cases exceeding the ADI were recorded for four colours, but assuming that manufacturers comply with the current legislation on MPL of colours in food, the intake of the colours assessed in scenario 2 should not be a reason for exceeding of ADIs for the target food colours.

Geographical variation in colour of female threespine stickleback (Gasterosteus aculeatus)

PubMed Central

Ingram, Travis; Bolnick, Daniel I.

2018-01-01

The ecological multifunctionality of colour often results in multiple selective pressures operating on a single trait. Most research on colour evolution focuses on males because they are the most conspicuous sex in most species. This bias can limit inferences about the ecological drivers of colour evolution. For example, little is known about population divergence in colour of female threespine stickleback (Gasterosteus aculeatus), which is among the most intensively-studied model vertebrates in evolution, ecology, and behaviour. In contrast, the evolution and ecology of colour in male stickleback has received considerable attention. One aspect of female colouration that is lacking previous research is non-ornamental body colour. Non-ornamental colour can play defensive and social roles, and indicate other aspects of female stickleback ecology. To remedy this knowledge gap, we measured the colour and brightness of one dorsal and one ventral lateral area on female stickleback from nine lake populations on Vancouver Island. We found that lake populations varied in overall colour brightness and dorso-ventral contrast. In addition, we found that female brightness increased with lake size, indicating potential ecological drivers of these colour differences. Our results demonstrate that there is substantial scope for future research on female colour diversification, which has been overlooked because past researchers focused on dramatic male nuptial colours. PMID:29785354

Geographical variation in colour of female threespine stickleback (Gasterosteus aculeatus).

PubMed

French, Connor M; Ingram, Travis; Bolnick, Daniel I

2018-01-01

The ecological multifunctionality of colour often results in multiple selective pressures operating on a single trait. Most research on colour evolution focuses on males because they are the most conspicuous sex in most species. This bias can limit inferences about the ecological drivers of colour evolution. For example, little is known about population divergence in colour of female threespine stickleback ( Gasterosteus aculeatus ), which is among the most intensively-studied model vertebrates in evolution, ecology, and behaviour. In contrast, the evolution and ecology of colour in male stickleback has received considerable attention. One aspect of female colouration that is lacking previous research is non-ornamental body colour. Non-ornamental colour can play defensive and social roles, and indicate other aspects of female stickleback ecology. To remedy this knowledge gap, we measured the colour and brightness of one dorsal and one ventral lateral area on female stickleback from nine lake populations on Vancouver Island. We found that lake populations varied in overall colour brightness and dorso-ventral contrast. In addition, we found that female brightness increased with lake size, indicating potential ecological drivers of these colour differences. Our results demonstrate that there is substantial scope for future research on female colour diversification, which has been overlooked because past researchers focused on dramatic male nuptial colours.

Two-colour chewing gum mixing ability test for evaluating masticatory performance in children with mixed dentition: validity and reliability study.

PubMed

Kaya, M S; Güçlü, B; Schimmel, M; Akyüz, S

2017-11-01

The unappealing taste of the chewing material and the time-consuming repetitive task in masticatory performance tests using artificial foodstuff may discourage children from performing natural chewing movements. Therefore, the aim was to determine the validity and reliability of a two-colour chewing gum mixing ability test for masticatory performance (MP) assessment in mixed dentition children. Masticatory performance was tested in two groups: systemically healthy fully dentate young adults and children in mixed dentition. Median particle size was assessed using a comminution test, and a two-colour chewing gum mixing ability test was applied for MP analysis. Validity was tested with Pearson correlation, and reliability was tested with intra-class correlation coefficient, Pearson correlation and Bland-Altman plots. Both comminution and two-colour chewing gum mixing ability tests revealed statistically significant MP differences between children (n = 25) and adults (n = 27, both P < 0·01). Pearson correlation between comminution and two-colour chewing gum mixing ability tests was positive and significant (r = 0·418, P = 0·002). Correlations for interobserver reliability and test-retest values were significant (r = 0·990, P = 0·0001 and r = 0·995, P = 0·0001). Although both methods could discriminate MP differences, the comminution test detected these differences generally in a wider range compared to two-colour chewing gum mixing ability test. However, considering the high reliability of the results, the two-colour chewing gum mixing ability test can be used to assess masticatory performance in children, especially at non-clinical settings. © 2017 John Wiley & Sons Ltd.

Tobacco TTG2 and ARF8 function concomitantly to control flower colouring by regulating anthocyanin synthesis genes.

PubMed

Li, P; Chen, X; Sun, F; Dong, H

2017-07-01

Recently we elucidated that tobacco TTG2 cooperates with ARF8 to regulate the vegetative growth and seed production. Here we show that TTG2 and ARF8 control flower colouring by regulating expression of ANS and DFR genes, which function in anthocyanin biosynthesis. Genetic modifications that substantially altered expression levels of the TTG2 gene and production quantities of TTG2 protein were correlated with flower development and colouring. Degrees of flower colour were increased by TTG2 overexpression but decreased through TTG2 silencing, in coincidence with high and low concentrations of anthocyanins in flowers. Of five genes involved in the anthocyanin biosynthesis pathway, only ANS and DFR were TTG2-regulated and displayed enhancement and diminution of expression with TTG2 overexpression and silencing, respectively. The floral expression of ANS and DFR also needed a functional ARF8 gene, as ANS and DFR expression were attenuated by ARF8 silencing, which concomitantly diminished the role of TTG2 in anthocyanin production. While ARF8 required TTG2 to be expressed by itself and to regulate ANS and DFR expression, the concurrent presence of normally functional TTG2 and ARF8 was critical for floral production of anthocyanins and also for flower colouration. Our data suggest that TTG2 functions concomitantly with ARF8 to control degrees of flower colour by regulating expression of ANS and DFR, which are involved in the anthocyanin biosynthesis pathway. ARF8 depends on TTG2 to regulate floral expression of ANS and DFR with positive effects on anthocyanin production and flower colour. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

Exposure estimate for FD&C colour additives for the US population.

PubMed

Doell, Diana L; Folmer, Daniel E; Lee, Hyoung S; Butts, Kyla M; Carberry, Susan E

2016-05-01

Dietary exposures to the seven food, drug, and cosmetic (FD&C) colour additives that are approved for general use in food in the United States were estimated for the US population (aged 2 years and older), children (aged 2-5 years) and teenage boys (aged 13-18 years) based on analytical levels of the FD&C colour additives in foods. Approximately 600 foods were chosen for analysis, based on a survey of product labels, for the levels of FD&C colour additives. Dietary exposure was estimated using both 2-day food consumption data from the combined 2007-10 National Health and Nutrition Examination Survey (NHANES) and 10-14-day food consumption data from the 2007-10 NPD Group, Inc. National Eating Trends - Nutrient Intake Database (NPD NET-NID). Dietary exposure was estimated at the mean and 90th percentile using three different exposure scenarios: low exposure, average exposure and high exposure, to account for the range in the amount of each FD&C colour additive for a given food. For all populations and all exposure scenarios, the highest cumulative eaters-only exposures in food were determined for FD&C Red No. 40, FD&C Yellow No. 5 and FD&C Yellow No. 6. In addition, the eaters-only exposure was estimated for individual food categories in order to determine which food categories contributed the most to the exposure for each FD&C colour additive. Breakfast Cereal, Juice Drinks, Soft Drinks, and Frozen Dairy Desserts/Sherbet (also referred to as Ice Cream, Frozen Yogurt, Sherbet (including Bars, Sticks, Sandwiches)) were the major contributing food categories to exposure for multiple FD&C colour additives for all three populations.

Cigarette brand variant portfolio strategy and the use of colour in a darkening market.

PubMed

Greenland, Steven J

2015-03-01

To evaluate cigarette branding strategies used to segment a market with some of the toughest tobacco controls. To document brand variant and packaging portfolios and assess the role played by colour before plain packaging, as well as consider the threat that recently implemented legislation poses for tobacco manufacturers. Brand variant and packaging details were extracted from manufacturer ingredient reports, as well as a retail audit of Australian supermarkets. Details were also collected for other product categories to provide perspective on cigarette portfolios. Secondary and primary data sources were analysed to evaluate variant and packaging portfolio strategy. In Australia, 12 leading cigarette brands supported 120 brand variants. Of these 61 had names with a specific colour and a further 26 had names with colour connotation. There were 338 corresponding packaging configurations, with most variants available in the primary cigarette distribution channel in four pack size options. Tobacco companies microsegment Australian consumers with highly differentiated product offerings and a family branding strategy that helps ameliorate the effects of marketing restrictions. To date, tobacco controls have had little negative impact upon variant and packaging portfolios, which have continued to expand. Colour has become a key visual signifier differentiating one variant from the next, and colour names are used to extend brand lines. However, the role of colour, as a heuristic to simplify consumer decision-making processes, becomes largely redundant with plain packaging. Plain packaging's impact upon manufacturers' branding strategies is therefore likely to be significant. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

The selectivity of responses to red-green colour and achromatic contrast in the human visual cortex: an fMRI adaptation study.

PubMed

Mullen, Kathy T; Chang, Dorita H F; Hess, Robert F

2015-12-01

There is controversy as to how responses to colour in the human brain are organized within the visual pathways. A key issue is whether there are modular pathways that respond selectively to colour or whether there are common neural substrates for both colour and achromatic (Ach) contrast. We used functional magnetic resonance imaging (fMRI) adaptation to investigate the responses of early and extrastriate visual areas to colour and Ach contrast. High-contrast red-green (RG) and Ach sinewave rings (0.5 cycles/degree, 2 Hz) were used as both adapting stimuli and test stimuli in a block design. We found robust adaptation to RG or Ach contrast in all visual areas. Cross-adaptation between RG and Ach contrast occurred in all areas indicating the presence of integrated, colour and Ach responses. Notably, we revealed contrasting trends for the two test stimuli. For the RG test, unselective processing (robust adaptation to both RG and Ach contrast) was most evident in the early visual areas (V1 and V2), but selective responses, revealed as greater adaptation between the same stimuli than cross-adaptation between different stimuli, emerged in the ventral cortex, in V4 and VO in particular. For the Ach test, unselective responses were again most evident in early visual areas but Ach selectivity emerged in the dorsal cortex (V3a and hMT+). Our findings support a strong presence of integrated mechanisms for colour and Ach contrast across the visual hierarchy, with a progression towards selective processing in extrastriate visual areas. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Exposure estimate for FD&C colour additives for the US population

PubMed Central

Folmer, Daniel E.; Lee, Hyoung S.; Butts, Kyla M.; Carberry, Susan E.

2016-01-01

Dietary exposures to the seven food, drug, and cosmetic (FD&C) colour additives that are approved for general use in food in the United States were estimated for the US population (aged 2 years and older), children (aged 2–5 years) and teenage boys (aged 13–18 years) based on analytical levels of the FD&C colour additives in foods. Approximately 600 foods were chosen for analysis, based on a survey of product labels, for the levels of FD&C colour additives. Dietary exposure was estimated using both 2-day food consumption data from the combined 2007–10 National Health and Nutrition Examination Survey (NHANES) and 10–14-day food consumption data from the 2007–10 NPD Group, Inc. National Eating Trends – Nutrient Intake Database (NPD NET-NID). Dietary exposure was estimated at the mean and 90th percentile using three different exposure scenarios: low exposure, average exposure and high exposure, to account for the range in the amount of each FD&C colour additive for a given food. For all populations and all exposure scenarios, the highest cumulative eaters-only exposures in food were determined for FD&C Red No. 40, FD&C Yellow No. 5 and FD&C Yellow No. 6. In addition, the eaters-only exposure was estimated for individual food categories in order to determine which food categories contributed the most to the exposure for each FD&C colour additive. Breakfast Cereal, Juice Drinks, Soft Drinks, and Frozen Dairy Desserts/Sherbet (also referred to as Ice Cream, Frozen Yogurt, Sherbet (including Bars, Sticks, Sandwiches)) were the major contributing food categories to exposure for multiple FD&C colour additives for all three populations. PMID:27092991

Synaesthetic colour in the brain: beyond colour areas. A functional magnetic resonance imaging study of synaesthetes and matched controls.

PubMed

van Leeuwen, Tessa M; Petersson, Karl Magnus; Hagoort, Peter

2010-08-10

In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e.g., letters elicit colour). Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory integration. In several neuroimaging studies, enhanced brain activity for grapheme-colour synaesthesia has been found in ventral-occipital areas that are also involved in real colour processing. Our question was whether the neural correlates of synaesthetically induced colour and real colour experience are truly shared. First, in a free viewing functional magnetic resonance imaging (fMRI) experiment, we located main effects of synaesthesia in left superior parietal lobule and in colour related areas. In the left superior parietal lobe, individual differences between synaesthetes (projector-associator distinction) also influenced brain activity, confirming the importance of the left superior parietal lobe for synaesthesia. Next, we applied a repetition suppression paradigm in fMRI, in which a decrease in the BOLD (blood-oxygenated-level-dependent) response is generally observed for repeated stimuli. We hypothesized that synaesthetically induced colours would lead to a reduction in BOLD response for subsequently presented real colours, if the neural correlates were overlapping. We did find BOLD suppression effects induced by synaesthesia, but not within the colour areas. Because synaesthetically induced colours were not able to suppress BOLD effects for real colour, we conclude that the neural correlates of synaesthetic colour experience and real colour experience are not fully shared. We propose that synaesthetic colour experiences are mediated by higher-order visual pathways that lie beyond the scope of classical, ventral-occipital visual areas. Feedback from these areas, in which the left parietal cortex is likely to play an important role, may induce V4 activation and the percept of synaesthetic colour.

Evaluation of Staining-Dependent Colour Changes in Resin Composites Using Principal Component Analysis

PubMed Central

Manojlovic, D.; Lenhardt, L.; Milićević, B.; Antonov, M.; Miletic, V.; Dramićanin, M. D.

2015-01-01

Colour changes in Gradia Direct™ composite after immersion in tea, coffee, red wine, Coca-Cola, Colgate mouthwash, and distilled water were evaluated using principal component analysis (PCA) and the CIELAB colour coordinates. The reflection spectra of the composites were used as input data for the PCA. The output data (scores and loadings) provided information about the magnitude and origin of the surface reflection changes after exposure to the staining solutions. The reflection spectra of the stained samples generally exhibited lower reflection in the blue spectral range, which was manifested in the lower content of the blue shade for the samples. Both analyses demonstrated the high staining abilities of tea, coffee, and red wine, which produced total colour changes of 4.31, 6.61, and 6.22, respectively, according to the CIELAB analysis. PCA revealed subtle changes in the reflection spectra of composites immersed in Coca-Cola, demonstrating Coca-Cola’s ability to stain the composite to a small degree. PMID:26450008

On transitions in the behaviour of tabu search algorithm TabuCol for graph colouring

NASA Astrophysics Data System (ADS)

Chalupa, D.

2018-01-01

Even though tabu search is one of the most popular metaheuristic search strategies, its understanding in terms of behavioural transitions and parameter tuning is still very limited. In this paper, we present a theoretical and experimental study of a popular tabu search algorithm TabuCol for graph colouring. We show that for some instances, there are sharp transitions in the behaviour of TabuCol, depending on the value of tabu tenure parameter. The location of this transition depends on graph structure and may also depend on its size. This is further supported by an experimental study of success rate profiles, which we define as an empirical measure of these transitions. We study the success rate profiles for a range of graph colouring instances, from 2-colouring of trees and forests to several instances from the DIMACS benchmark. These reveal that TabuCol may exhibit a spectrum of different behaviours ranging from simple transitions to highly complex probabilistic behaviour.

Use of a flor velum yeast for modulating colour, ethanol and major aroma compound contents in red wine.

PubMed

Moreno, Juan; Moreno-García, Jaime; López-Muñoz, Beatriz; Mauricio, Juan Carlos; García-Martínez, Teresa

2016-12-15

The most important and negative effect of the global warming for winemakers in warm and sunny regions is the observed lag between industrial and phenolic grape ripeness, so only it is possible to obtain an acceptable colour when the ethanol content of wine is high. By contrast, the actual market trends are to low ethanol content wines. Flor yeast growing a short time under velum conditions, decreases the ethanol and volatile acidity contents, has a favorable effect on the colour and astringency and significantly changes the wine content in 1-propanol, isobutanol, acetaldehyde, 1,1-diethoxiethane and ethyl lactate. The Principal Component Analysis of six enological parameters or five aroma compounds allows to classify the wines subjected to different velum formation conditions. The obtained results in two tasting sessions suggest that the flor yeast helps to modulate the ethanol, astringency and colour and supports a new biotechnological perspective for red winemakers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Can colours be used to segment words when reading?

PubMed

Perea, Manuel; Tejero, Pilar; Winskel, Heather

2015-07-01

Rayner, Fischer, and Pollatsek (1998, Vision Research) demonstrated that reading unspaced text in Indo-European languages produces a substantial reading cost in word identification (as deduced from an increased word-frequency effect on target words embedded in the unspaced vs. spaced sentences) and in eye movement guidance (as deduced from landing sites closer to the beginning of the words in unspaced sentences). However, the addition of spaces between words comes with a cost: nearby words may fall outside high-acuity central vision, thus reducing the potential benefits of parafoveal processing. In the present experiment, we introduced a salient visual cue intended to facilitate the process of word segmentation without compromising visual acuity: each alternating word was printed in a different colour (i.e., ). Results only revealed a small reading cost of unspaced alternating colour sentences relative to the spaced sentences. Thus, present data are a demonstration that colour can be useful to segment words for readers of spaced orthographies. Copyright © 2015 Elsevier B.V. All rights reserved.

Actively addressed single pixel full-colour plasmonic display

PubMed Central

Franklin, Daniel; Frank, Russell; Wu, Shin-Tson; Chanda, Debashis

2017-01-01

Dynamic, colour-changing surfaces have many applications including displays, wearables and active camouflage. Plasmonic nanostructures can fill this role by having the advantages of ultra-small pixels, high reflectivity and post-fabrication tuning through control of the surrounding media. However, previous reports of post-fabrication tuning have yet to cover a full red-green-blue (RGB) colour basis set with a single nanostructure of singular dimensions. Here, we report a method which greatly advances this tuning and demonstrates a liquid crystal-plasmonic system that covers the full RGB colour basis set, only as a function of voltage. This is accomplished through a surface morphology-induced, polarization-dependent plasmonic resonance and a combination of bulk and surface liquid crystal effects that manifest at different voltages. We further demonstrate the system's compatibility with existing LCD technology by integrating it with a commercially available thin-film-transistor array. The imprinted surface interfaces readily with computers to display images as well as video. PMID:28488671

Evaluation of Staining-Dependent Colour Changes in Resin Composites Using Principal Component Analysis.

PubMed

Manojlovic, D; Lenhardt, L; Milićević, B; Antonov, M; Miletic, V; Dramićanin, M D

2015-10-09

Colour changes in Gradia Direct™ composite after immersion in tea, coffee, red wine, Coca-Cola, Colgate mouthwash, and distilled water were evaluated using principal component analysis (PCA) and the CIELAB colour coordinates. The reflection spectra of the composites were used as input data for the PCA. The output data (scores and loadings) provided information about the magnitude and origin of the surface reflection changes after exposure to the staining solutions. The reflection spectra of the stained samples generally exhibited lower reflection in the blue spectral range, which was manifested in the lower content of the blue shade for the samples. Both analyses demonstrated the high staining abilities of tea, coffee, and red wine, which produced total colour changes of 4.31, 6.61, and 6.22, respectively, according to the CIELAB analysis. PCA revealed subtle changes in the reflection spectra of composites immersed in Coca-Cola, demonstrating Coca-Cola's ability to stain the composite to a small degree.

Anthocyanins of Coloured Wheat Genotypes in Specific Response to SalStress.

PubMed

Mbarki, Sonia; Sytar, Oksana; Zivcak, Marek; Abdelly, Chedly; Cerda, Artemio; Brestic, Marian

2018-06-23

The present study investigated the effect of salt stress on the development of adaptive responses and growth parameters of different coloured wheat genotypes. The different coloured wheat genotypes have revealed variation in the anthocyanin content, which may affect the development of adaptive responses under increasing salinity stress. In the early stage of treatment with salt at a lower NaCl concentration (100 mM), anthocyanins and proline accumulate, which shows rapid development of the stress reaction. A dose-dependent increase in flavonol content was observed for wheat genotypes with more intense purple-blue pigmentation after treatment with 150 mM and 200 mM NaCl. The content of Na⁺ and K⁺ obtained at different levels of salinity based on dry weight (DW) was more than 3 times greater than the control, with a significant increase of both ions under salt stress. Overall, our results demonstrated that coloured wheat genotypes with high anthocyanin content are able to maintain significantly higher dry matter production after salt stress treatment.

Development of Fire Detection Algorithm at Its Early Stage Using Fire Colour and Shape Information

NASA Astrophysics Data System (ADS)

Suleiman Abdullahi, Zainab; Hamisu Dalhatu, Shehu; Hassan Abdullahi, Zakariyya

2018-04-01

Fire can be defined as a state in which substances combined chemically with oxygen from the air and give out heat, smoke and flame. Most of the conventional fire detection techniques such as smoke, fire and heat detectors respectively have a problem of travelling delay and also give a high false alarm. The algorithm begins by loading the selected video clip from the database developed to identify the present or absence of fire in a frame. In this approach, background subtraction was employed. If the result of subtraction is less than the set threshold, the difference is ignored and the next frame is taken. However, if the difference is equal to or greater than the set threshold then it subjected to colour and shape test. This is done by using combined RGB colour model and shape signature. The proposed technique was very effective in detecting fire compared to those technique using only motion or colour clues.

Spectral energy distributions and colours of hot subluminous stars

NASA Astrophysics Data System (ADS)

Heber, Ulrich; Irrgang, Andreas; Schaffenroth, Johannes

2018-02-01

Photometric surveys at optical, ultraviolet, and infrared wavelengths provide ever-growing datasets as major surveys proceed. Colour-colour diagrams are useful tools to identify classes of star and provide large samples. However, combining all photometric measurements of a star into a spectral energy distribution will allow quantitative analyses to be carried out. We demonstrate how to construct and exploit spectral energy distributions and colours for sublumious B (sdB) stars. The aim is to identify cool companions to hot subdwarfs and to determine atmospheric parameters of apparently single sdB stars as well as composite spectrum sdB binaries.We analyse two sdB stars with high-quality photometric data which serve as our benchmarks, the apparently single sdB HD205805 and the sdB + K5 binary PG 0749+658, briefly present preliminary results for the sample of 142 sdB binaries with known orbits, and discuss future prospects from ongoing all-sky optical space- (Gaia) and ground-based (e.g. SkyMapper) as well as NIR surveys.

µ-XRF Studies on the Colour Brilliance in Ancient Wool Carpets

PubMed Central

Meyer, Markus; Borca, Camelia N.; Huthwelker, Thomas; Bieber, Manfred; Meßlinger, Karl; Fink, Rainer H.

2017-01-01

Many handmade ancient and recent oriental wool carpets show outstanding brilliance and persistence of colour that is not achieved by common industrial dyeing procedures. Anthropologists have suggested the influence of wool fermentation prior to dyeing as key technique to achieve the high dyeing quality. By means of μ-XRF elemental mapping of mordant metals we corroborate this view and show a deep and homogenous penetration of colourants into fermented wool fibres. Furthermore we are able to apply this technique and prove that the fermentation process for ancient specimens cannot be investigated by standard methods due to the lack of intact cuticle layers. This finding suggests a broad range of further investigations that will contribute to a deeper understanding of the development of traditional dyeing techniques. Spectroscopic studies add information on the oxidation states of the metal ions within the respective mordant-dye-complexes and suggest a partial charge transfer as basis for a significant colour change when Fe mordants are used. PMID:29109824

An extensive colour palette in Roman villas in Burgos, Northern Spain: a Raman spectroscopic analysis.

PubMed

Villar, S E J; Edwards, H G M

2005-05-01

Seventy-five specimens from thirty fragments of Roman villa wall-paintings from sites in Burgos Castilla y Leon, Spain, have been analysed by Raman spectroscopy. This is the first time that a Raman spectrocopic study of Roman wall-paintings from Spain has been reported. The extensive range of tonalities and colour compositions contrasts with the results found in other provinces of the Roman Empire, for example Romano-British villas. Calcite, aragonite, haematite, caput mortuum, cinnabar, limonite, goethite, cuprorivaite, lazurite, green earth, carbon and verdigris have been found as pigments. Some mineral mixtures with different tonalities have been made using different strategies to those more usually found. Of particular interest is the assignation of the Tarna mine for the origin of the cinnabar used for obtaining the red colour in some specimens analysed here. The wide range of colours, tonalities and minerals found in some of the sites studied in this work is suggestive of a high social status for the community.

Review paper on current technologies for decolourisation of textile wastewaters: perspectives for anaerobic biotechnology.

PubMed

dos Santos, André B; Cervantes, Francisco J; van Lier, Jules B

2007-09-01

Dyes are natural and xenobiotic compounds that make the world more beautiful through coloured substances. However, the release of coloured wastewaters represents a serious environmental problem and a public health concern. Colour removal, especially from textile wastewaters, has been a big challenge over the last decades, and up to now there is no single and economically attractive treatment that can effectively decolourise dyes. In the passed years, notable achievements were made in the use of biotechnological applications to textile wastewaters not only for colour removal but also for the complete mineralization of dyes. Different microorganisms such as aerobic and anaerobic bacteria, fungi and actinomycetes have been found to catalyse dye decolourisation. Moreover, promising results were obtained in accelerating dye decolourisation by adding mediating compounds and/or changing process conditions to high temperatures. This paper provides a critical review on the current technologies available for decolourisation of textile wastewaters and it suggests effective and economically attractive alternatives.

High fitness costs of climate change-induced camouflage mismatch.

PubMed

Zimova, Marketa; Mills, L Scott; Nowak, J Joshua

2016-03-01

Anthropogenic climate change has created myriad stressors that threaten to cause local extinctions if wild populations fail to adapt to novel conditions. We studied individual and population-level fitness costs of a climate change-induced stressor: camouflage mismatch in seasonally colour molting species confronting decreasing snow cover duration. Based on field measurements of radiocollared snowshoe hares, we found strong selection on coat colour molt phenology, such that animals mismatched with the colour of their background experienced weekly survival decreases up to 7%. In the absence of adaptive response, we show that these mortality costs would result in strong population-level declines by the end of the century. However, natural selection acting on wide individual variation in molt phenology might enable evolutionary adaptation to camouflage mismatch. We conclude that evolutionary rescue will be critical for hares and other colour molting species to keep up with climate change. © 2016 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

The role of pollinators in maintaining variation in flower colour in the Rocky Mountain columbine, Aquilegia coerulea.

PubMed

Thairu, Margaret W; Brunet, Johanne

2015-05-01

Flower colour varies within and among populations of the Rocky Mountain columbine, Aquilegia coerulea, in conjunction with the abundance of its two major pollinators, hawkmoths and bumble-bees. This study seeks to understand whether the choice of flower colour by these major pollinators can help explain the variation in flower colour observed in A. coerulea populations. Dual choice assays and experimental arrays of blue and white flowers were used to determine the preference of hawkmoths and bumble-bees for flower colour. A test was made to determine whether a differential preference for flower colour, with bumble-bees preferring blue and hawkmoths white flowers, could explain the variation in flower colour. Whether a single pollinator could maintain a flower colour polymorphism was examined by testing to see if preference for a flower colour varied between day and dusk for hawkmoths and whether bumble-bees preferred novel or rare flower colour morphs. Hawkmoths preferred blue flowers under both day and dusk light conditions. Naïve bumble-bees preferred blue flowers but quickly learned to forage randomly on the two colour morphs when similar rewards were presented in the flowers. Bees quickly learned to associate a flower colour with a pollen reward. Prior experience affected the choice of flower colour by bees, but they did not preferentially visit novel flower colours or rare or common colour morphs. Differences in flower colour preference between the two major pollinators could not explain the variation in flower colour observed in A. coerulea. The preference of hawkmoths for flower colour did not change between day and dusk, and bumble-bees did not prefer a novel or a rare flower colour morph. The data therefore suggest that factors other than pollinators may be more likely to affect the flower colour variation observed in A. coerulea. Published by Oxford University Press on behalf of the Annals of Botany Company 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Multivariate methods to visualise colour-space and colour discrimination data.

PubMed

Hastings, Gareth D; Rubin, Alan

2015-01-01

Despite most modern colour spaces treating colour as three-dimensional (3-D), colour data is usually not visualised in 3-D (and two-dimensional (2-D) projection-plane segments and multiple 2-D perspective views are used instead). The objectives of this article are firstly, to introduce a truly 3-D percept of colour space using stereo-pairs, secondly to view colour discrimination data using that platform, and thirdly to apply formal statistics and multivariate methods to analyse the data in 3-D. This is the first demonstration of the software that generated stereo-pairs of RGB colour space, as well as of a new computerised procedure that investigated colour discrimination by measuring colour just noticeable differences (JND). An initial pilot study and thorough investigation of instrument repeatability were performed. Thereafter, to demonstrate the capabilities of the software, five colour-normal and one colour-deficient subject were examined using the JND procedure and multivariate methods of data analysis. Scatter plots of responses were meaningfully examined in 3-D and were useful in evaluating multivariate normality as well as identifying outliers. The extent and direction of the difference between each JND response and the stimulus colour point was calculated and appreciated in 3-D. Ellipsoidal surfaces of constant probability density (distribution ellipsoids) were fitted to response data; the volumes of these ellipsoids appeared useful in differentiating the colour-deficient subject from the colour-normals. Hypothesis tests of variances and covariances showed many statistically significant differences between the results of the colour-deficient subject and those of the colour-normals, while far fewer differences were found when comparing within colour-normals. The 3-D visualisation of colour data using stereo-pairs, as well as the statistics and multivariate methods of analysis employed, were found to be unique and useful tools in the representation and study of colour. Many additional studies using these methods along with the JND and other procedures have been identified and will be reported in future publications. © 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.

False-colour palette generation using a reference colour gamut

NASA Astrophysics Data System (ADS)

Green, Phil

2015-01-01

Monochrome images are often converted to false-colour images, in which arbitrary colours are assigned to regions of the image to aid recognition of features within the image. Criteria for selection of colour palettes vary according to the application, but may include distinctiveness, extensibility, consistency, preference, meaningfulness and universality. A method for defining a palette from colours on the surface of a reference gamut is described, which ensures that all colours in the palette have the maximum chroma available for the given hue angle in the reference gamut. The palette can be re-targeted to a reproduction medium as needed using colour management, and this method ensures consistency between cross-media colour reproductions using the palette.

The effect of high-pressure processing on colour, bioactive compounds, and antioxidant activity in smoothies during refrigerated storage.

PubMed

Andrés, Víctor; Villanueva, María J; Tenorio, María D

2016-02-01

The effects of high-pressure processing--HPP--(450 and 600 MPa/3 min/20 °C) on the colour, carotenoids, ascorbic acid, polyphenols and antioxidant activity (FRAP and DPPH) of a smoothie were compared to thermal processing (80 °C/3 min). Stability during 45 days at 4 °C was also evaluated. HPP samples showed slight differences (p < 0.05) in colour compared to untreated smoothies. Both HPP significantly increased the extractability of lycopene, β-carotene and polyphenols compared to untreated samples. After HPP, ascorbic acid was retained by more than 92% of the initial content. The best results for antioxidant activity were obtained when HPP was applied at 600 MPa. FRAP and DPPH showed a high correlation with ascorbic acid (R(2) = 0.7135 and 0.8107, respectively) and polyphenolic compounds (R(2) = 0.6819 and 0.6935, respectively), but not with total carotenoids. Changes in bioactive compounds during the storage period were lower in the HPP smoothie than in the thermal-treated sample. Copyright © 2015 Elsevier Ltd. All rights reserved.

An Ecological Alternative to Snodgrass & Vanderwart: 360 High Quality Colour Images with Norms for Seven Psycholinguistic Variables

PubMed Central

Moreno-Martínez, Francisco Javier; Montoro, Pedro R.

2012-01-01

This work presents a new set of 360 high quality colour images belonging to 23 semantic subcategories. Two hundred and thirty-six Spanish speakers named the items and also provided data from seven relevant psycholinguistic variables: age of acquisition, familiarity, manipulability, name agreement, typicality and visual complexity. Furthermore, we also present lexical frequency data derived from Internet search hits. Apart from the high number of variables evaluated, knowing that it affects the processing of stimuli, this new set presents important advantages over other similar image corpi: (a) this corpus presents a broad number of subcategories and images; for example, this will permit researchers to select stimuli of appropriate difficulty as required, (e.g., to deal with problems derived from ceiling effects); (b) the fact of using coloured stimuli provides a more realistic, ecologically-valid, representation of real life objects. In sum, this set of stimuli provides a useful tool for research on visual object-and word- processing, both in neurological patients and in healthy controls. PMID:22662166

Memory colours affect colour appearance.

PubMed

Witzel, Christoph; Olkkonen, Maria; Gegenfurtner, Karl R

2016-01-01

Memory colour effects show that colour perception is affected by memory and prior knowledge and hence by cognition. None of Firestone & Scholl's (F&S's) potential pitfalls apply to our work on memory colours. We present a Bayesian model of colour appearance to illustrate that an interaction between perception and memory is plausible from the perspective of vision science.

Binding of motion and colour is early and automatic.

PubMed

Blaser, Erik; Papathomas, Thomas; Vidnyánszky, Zoltán

2005-04-01

At what stages of the human visual hierarchy different features are bound together, and whether this binding requires attention, is still highly debated. We used a colour-contingent motion after-effect (CCMAE) to study the binding of colour and motion signals. The logic of our approach was as follows: if CCMAEs can be evoked by targeted adaptation of early motion processing stages, without allowing for feedback from higher motion integration stages, then this would support our hypothesis that colour and motion are bound automatically on the basis of spatiotemporally local information. Our results show for the first time that CCMAE's can be evoked by adaptation to a locally paired opposite-motion dot display, a stimulus that, importantly, is known to trigger direction-specific responses in the primary visual cortex yet results in strong inhibition of the directional responses in area MT of macaques as well as in area MT+ in humans and, indeed, is perceived only as motionless flicker. The magnitude of the CCMAE in the locally paired condition was not significantly different from control conditions where the different directions were spatiotemporally separated (i.e. not locally paired) and therefore perceived as two moving fields. These findings provide evidence that adaptation at an early, local motion stage, and only adaptation at this stage, underlies this CCMAE, which in turn implies that spatiotemporally coincident colour and motion signals are bound automatically, most probably as early as cortical area V1, even when the association between colour and motion is perceptually inaccessible.

Automatic system for detecting pornographic images

NASA Astrophysics Data System (ADS)

Ho, Kevin I. C.; Chen, Tung-Shou; Ho, Jun-Der

2002-09-01

Due to the dramatic growth of network and multimedia technology, people can more easily get variant information by using Internet. Unfortunately, it also makes the diffusion of illegal and harmful content much easier. So, it becomes an important topic for the Internet society to protect and safeguard Internet users from these content that may be encountered while surfing on the Net, especially children. Among these content, porno graphs cause more serious harm. Therefore, in this study, we propose an automatic system to detect still colour porno graphs. Starting from this result, we plan to develop an automatic system to search porno graphs or to filter porno graphs. Almost all the porno graphs possess one common characteristic that is the ratio of the size of skin region and non-skin region is high. Based on this characteristic, our system first converts the colour space from RGB colour space to HSV colour space so as to segment all the possible skin-colour regions from scene background. We also apply the texture analysis on the selected skin-colour regions to separate the skin regions from non-skin regions. Then, we try to group the adjacent pixels located in skin regions. If the ratio is over a given threshold, we can tell if the given image is a possible porno graph. Based on our experiment, less than 10% of non-porno graphs are classified as pornography, and over 80% of the most harmful porno graphs are classified correctly.

A new scoring model for characterization of adnexal masses based on two-dimensional gray-scale and colour Doppler sonographic features

PubMed Central

Abbas, A.M.; Zahran, K.M.; Nasr, A.; Kamel, H.S.

2014-01-01

Objective: To determine the most discriminating two-dimensional gray-scale and colour Doppler sonographic features that allow differentiation between malignant and benign adnexal masses, and to develop a scoring model that would enable more accurate diagnosis with those features. Methods: A cross sectional prospective study was conducted on patients scheduled for surgery due to presence of adnexal masses at Woman’s Health Center, Assiut University, Egypt between October 2012 and October 2013. All patients were evaluated by 2D ultrasound for morphological features of the masses combined with colour Doppler examination of their vessels. The final diagnosis, based on histopathological analysis, was used as a gold standard. Results: One hundred forty-six patients were recruited, 104 with benign masses, 42 with malignant masses. Features that allowed statistically significant discrimination of benignity from malignancy were; volume of mass, type of mass, presence and thickness of septae, presence and length of papillary projections, location of vessels at colour Doppler and colour score. A scoring model was formulated combining these features together; Assiut Scoring Model (ASM). The cut-off level with the highest accuracy in detection of malignancy, was ≥6, had a sensitivity of 93.5% and specificity of 92.2%. Conclusion: Our Scoring Model; a multiparameter scoring using four gray-scale ultrasound and two colour Doppler features, had shown a high sensitivity and specificity for prediction of malignancy in adnexal masses compared with previous scoring systems. PMID:25009729

The GhTT2_A07 gene is linked to the brown colour and natural flame retardancy phenotypes of Lc1 cotton (Gossypium hirsutum L.) fibres.

PubMed

Hinchliffe, Doug J; Condon, Brian D; Thyssen, Gregory; Naoumkina, Marina; Madison, Crista A; Reynolds, Michael; Delhom, Christopher D; Fang, David D; Li, Ping; McCarty, Jack

2016-10-01

Some naturally coloured brown cotton fibres from accessions of Gossypium hirsutum L. can be used to make textiles with enhanced flame retardancy (FR). Several independent brown fibre loci have been identified and mapped to chromosomes, but the underlying genes have not yet been identified, and the mechanism of lint fibre FR is not yet fully understood. In this study, we show that both the brown colour and enhanced FR of the Lc1 lint colour locus are linked to a 1.4Mb inversion on chromosome A07 that is immediately upstream of a gene with similarity to Arabidopsis TRANSPARENT TESTA 2 (TT2). As a result of the alternative upstream sequence, the transcription factor GhTT2_A07 is highly up-regulated in developing fibres. In turn, genes in the phenylpropanoid metabolic pathway are activated, leading to biosynthesis of proanthocyanidins and accumulation of inorganic elements. We show that enhanced FR and anthocyanin precursors appear in developing brown fibres well before the brown colour is detectible, demonstrating for the first time that the polymerized proanthocyanidins that constitute the brown colour are not the source of enhanced FR. Identifying the particular colourless metabolite that provides Lc1 cotton with enhanced FR could help minimize the use of synthetic chemical flame retardant additives in textiles. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Quantifying plant colour and colour difference as perceived by humans using digital images.

PubMed

Kendal, Dave; Hauser, Cindy E; Garrard, Georgia E; Jellinek, Sacha; Giljohann, Katherine M; Moore, Joslin L

2013-01-01

Human perception of plant leaf and flower colour can influence species management. Colour and colour contrast may influence the detectability of invasive or rare species during surveys. Quantitative, repeatable measures of plant colour are required for comparison across studies and generalisation across species. We present a standard method for measuring plant leaf and flower colour traits using images taken with digital cameras. We demonstrate the method by quantifying the colour of and colour difference between the flowers of eleven grassland species near Falls Creek, Australia, as part of an invasive species detection experiment. The reliability of the method was tested by measuring the leaf colour of five residential garden shrub species in Ballarat, Australia using five different types of digital camera. Flowers and leaves had overlapping but distinct colour distributions. Calculated colour differences corresponded well with qualitative comparisons. Estimates of proportional cover of yellow flowers identified using colour measurements correlated well with estimates obtained by measuring and counting individual flowers. Digital SLR and mirrorless cameras were superior to phone cameras and point-and-shoot cameras for producing reliable measurements, particularly under variable lighting conditions. The analysis of digital images taken with digital cameras is a practicable method for quantifying plant flower and leaf colour in the field or lab. Quantitative, repeatable measurements allow for comparisons between species and generalisations across species and studies. This allows plant colour to be related to human perception and preferences and, ultimately, species management.

Quantifying Plant Colour and Colour Difference as Perceived by Humans Using Digital Images

PubMed Central

Kendal, Dave; Hauser, Cindy E.; Garrard, Georgia E.; Jellinek, Sacha; Giljohann, Katherine M.; Moore, Joslin L.

2013-01-01

Human perception of plant leaf and flower colour can influence species management. Colour and colour contrast may influence the detectability of invasive or rare species during surveys. Quantitative, repeatable measures of plant colour are required for comparison across studies and generalisation across species. We present a standard method for measuring plant leaf and flower colour traits using images taken with digital cameras. We demonstrate the method by quantifying the colour of and colour difference between the flowers of eleven grassland species near Falls Creek, Australia, as part of an invasive species detection experiment. The reliability of the method was tested by measuring the leaf colour of five residential garden shrub species in Ballarat, Australia using five different types of digital camera. Flowers and leaves had overlapping but distinct colour distributions. Calculated colour differences corresponded well with qualitative comparisons. Estimates of proportional cover of yellow flowers identified using colour measurements correlated well with estimates obtained by measuring and counting individual flowers. Digital SLR and mirrorless cameras were superior to phone cameras and point-and-shoot cameras for producing reliable measurements, particularly under variable lighting conditions. The analysis of digital images taken with digital cameras is a practicable method for quantifying plant flower and leaf colour in the field or lab. Quantitative, repeatable measurements allow for comparisons between species and generalisations across species and studies. This allows plant colour to be related to human perception and preferences and, ultimately, species management. PMID:23977275

Prevalence of Colour Vision Anomalies Amongst Dental Professionals and its Effect on Shade Matching of Teeth.

PubMed

Khosla, Amrit; Maini, Anuj Paul; Wangoo, Anuj; Singh, Sukhman; Mehar, Damanpreet Kaur

2017-01-01

The success of a restoration is dependent on accurate shade matching of teeth leading to studies evaluating the factors affecting the perception of shades. Colour vision anomalies including colour blindness have been found to exist in the population and it has been thought to be a potential factor affecting the colour perception ability. The present study was done to evaluate the prevalence of colour vision anomalies and its effect on matching of shades of teeth. A total of 147 dental professionals were randomly selected for the study and were first tested for visual acuity using the Snellen's Eye Chart so as to carry on the study with only those operators who had a vision of 6/6. Then, the Ishihara's colour charts were used to test the operators for colour vision handicap. In the last stage of the study, test for accuracy of shade selection was done using the Vitapan Classical shade guide. The shade guide tabs were covered to avoid bias. Percentage was used to calculate the prevalence of colour vision handicap and its effect on matching of shades of teeth as compared to normal vision, which was evaluated using Chi square test. Nineteen operators had colour vision anomalies out of hundred operators and only two operators presented with colour blindness. Colour vision anomaly was more prevalent than colour blindness and it was also found that it was more prevalent in males than females. The difference between the accuracy of shade matching between the operators with normal vision and colour vision defect and operators with normal vision and colour blindness was statistically not significant. Colour blindness and colour vision handicap are rare conditions, with the latter being more common in the population. According to our study, it was concluded that no statistically significant difference existed amongst the operators with normal vision and colour vision anomaly or operators with normal vision and colour blindness during the matching of shades of teeth.

View compensated compression of volume rendered images for remote visualization.

PubMed

Lalgudi, Hariharan G; Marcellin, Michael W; Bilgin, Ali; Oh, Han; Nadar, Mariappan S

2009-07-01

Remote visualization of volumetric images has gained importance over the past few years in medical and industrial applications. Volume visualization is a computationally intensive process, often requiring hardware acceleration to achieve a real time viewing experience. One remote visualization model that can accomplish this would transmit rendered images from a server, based on viewpoint requests from a client. For constrained server-client bandwidth, an efficient compression scheme is vital for transmitting high quality rendered images. In this paper, we present a new view compensation scheme that utilizes the geometric relationship between viewpoints to exploit the correlation between successive rendered images. The proposed method obviates motion estimation between rendered images, enabling significant reduction to the complexity of a compressor. Additionally, the view compensation scheme, in conjunction with JPEG2000 performs better than AVC, the state of the art video compression standard.

Colour bio-factories: Towards scale-up production of anthocyanins in plant cell cultures.

PubMed

Appelhagen, Ingo; Wulff-Vester, Anders Keim; Wendell, Micael; Hvoslef-Eide, Anne-Kathrine; Russell, Julia; Oertel, Anne; Martens, Stefan; Mock, Hans-Peter; Martin, Cathie; Matros, Andrea

2018-06-08

Anthocyanins are widely distributed, glycosylated, water-soluble plant pigments, which give many fruits and flowers their red, purple or blue colouration. Their beneficial effects in a dietary context have encouraged increasing use of anthocyanins as natural colourants in the food and cosmetic industries. However, the limited availability and diversity of anthocyanins commercially have initiated searches for alternative sources of these natural colourants. In plants, high-level production of secondary metabolites, such as anthocyanins, can be achieved by engineering of regulatory genes as well as genes encoding biosynthetic enzymes. We have used tobacco lines which constitutively produce high levels of cyanidin 3-O-rutinoside, delphinidin 3-O-rutinoside or a novel anthocyanin, acylated cyanidin 3-O-(coumaroyl) rutinoside to generate cell suspension cultures. The cell lines are stable in their production rates and superior to conventional plant cell cultures. Scale-up of anthocyanin production in small scale fermenters has been demonstrated. The cell cultures have also proven to be a suitable system for production of 13 C-labelled anthocyanins. Our method for anthocyanin production is transferable to other plant species, such as Arabidopsis thaliana, demonstrating the potential of this approach for making a wide range of highly-decorated anthocyanins. The tobacco cell cultures represent a customisable and sustainable alternative to conventional anthocyanin production platforms and have considerable potential for use in industrial and medical applications of anthocyanins. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

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.

Geographic divergence and colour change in response to visual backgrounds and illumination intensity in bearded dragons.

PubMed

Cadena, Viviana; Smith, Kathleen R; Endler, John A; Stuart-Fox, Devi

2017-03-15

Animals may improve camouflage by both dynamic colour change and local evolutionary adaptation of colour but we have little understanding of their relative importance in colour-changing species. We tested for differences in colour change in response to background colour and light intensity in two populations of central bearded dragon lizards ( Pogona vitticeps ) representing the extremes in body coloration and geographical range. We found that bearded dragons change colour in response to various backgrounds and that colour change is affected by illumination intensity. Within-individual colour change was similar in magnitude in the two populations but varied between backgrounds. However, at the endpoints of colour change, each population showed greater similarity to backgrounds that were representative of the local habitat compared with the other population, indicating local adaptation to visual backgrounds. Our results suggest that even in species that change colour, both phenotypic plasticity and geographic divergence of coloration may contribute to improved camouflage. © 2017. Published by The Company of Biologists Ltd.

Understanding WCAG2.0 Colour Contrast Requirements Through 3D Colour Space Visualisation.

PubMed

Sandnes, Frode Eika

2016-01-01

Sufficient contrast between text and background is needed to achieve sufficient readability. WCAG2.0 provides a specific definition of sufficient contrast on the web. However, the definition is hard to understand and most designers thus use contrast calculators to validate their colour choices. Often, such checks are performed after design and this may be too late. This paper proposes a colour selection approach based on three-dimensional visualisation of the colour space. The complex non-linear relationships between the colour components become comprehendible when viewed in 3D. The method visualises the available colours in an intuitive manner and allows designers to check a colour against the set of other valid colours. Unlike the contrast calculators, the proposed method is proactive and fun to use. A colour space builder was developed and the resulting models were viewed with a point cloud viewer. The technique can be used as both a design tool and a pedagogical aid to teach colour theory and design.

Pairwise mixture model for unmixing partial volume effect in multi-voxel MR spectroscopy of brain tumour patients

NASA Astrophysics Data System (ADS)

Olliverre, Nathan; Asad, Muhammad; Yang, Guang; Howe, Franklyn; Slabaugh, Gregory

2017-03-01

Multi-Voxel Magnetic Resonance Spectroscopy (MV-MRS) provides an important and insightful technique for the examination of the chemical composition of brain tissue, making it an attractive medical imaging modality for the examination of brain tumours. MRS, however, is affected by the issue of the Partial Volume Effect (PVE), where the signals of multiple tissue types can be found within a single voxel and provides an obstacle to the interpretation of the data. The PVE results from the low resolution achieved in MV-MRS images relating to the signal to noise ratio (SNR). To counteract PVE, this paper proposes a novel Pairwise Mixture Model (PMM), that extends a recently reported Signal Mixture Model (SMM) for representing the MV-MRS signal as normal, low or high grade tissue types. Inspired by Conditional Random Field (CRF) and its continuous variant the PMM incorporates the surrounding voxel neighbourhood into an optimisation problem, the solution of which provides an estimation to a set of coefficients. The values of the estimated coefficients represents the amount of each tissue type (normal, low or high) found within a voxel. These coefficients can then be visualised as a nosological rendering using a coloured grid representing the MV-MRS image overlaid on top of a structural image, such as a Magnetic Resonance Image (MRI). Experimental results show an accuracy of 92.69% in classifying patient tumours as either low or high grade compared against the histopathology for each patient. Compared to 91.96% achieved by the SMM, the proposed PMM method demonstrates the importance of incorporating spatial coherence into the estimation as well as its potential clinical usage.

Colour correct: the interactive effects of food label nutrition colouring schemes and food category healthiness on health perceptions.

PubMed

Nyilasy, Gergely; Lei, Jing; Nagpal, Anish; Tan, Joseph

2016-08-01

The purpose of the present study was to examine the effects of food label nutrition colouring schemes in interaction with food category healthiness on consumers' perceptions of food healthiness. Three streams of colour theory (colour attention, colour association and colour approach-avoidance) in interaction with heuristic processing theory provide consonant predictions and explanations for the underlying psychological processes. A 2 (food category healthiness: healthy v. unhealthy)×3 (food label nutrient colouring schemes: healthy=green, unhealthy=red (HGUR) v. healthy=red, unhealthy=green (HRUG) v. no colour (control)) between-subjects design was used. The research setting was a randomised-controlled experiment using varying formats of food packages and nutritional information colouring. Respondents (n 196) sourced from a national consumer panel, USA. The findings suggest that, for healthy foods, the nutritional colouring schemes reduced perceived healthiness, irrespective of which nutrients were coloured red or green (healthinesscontrol=4·86; healthinessHGUR=4·10; healthinessHRUG=3·70). In contrast, for unhealthy foods, there was no significant difference in perceptions of food healthiness when comparing different colouring schemes against the control. The results make an important qualification to the common belief that colour coding can enhance the correct interpretation of nutrition information and suggest that this incentive may not necessarily support healthier food choices in all situations.

Robust colour calibration of an imaging system using a colour space transform and advanced regression modelling.

PubMed

Jackman, Patrick; Sun, Da-Wen; Elmasry, Gamal

2012-08-01

A new algorithm for the conversion of device dependent RGB colour data into device independent L*a*b* colour data without introducing noticeable error has been developed. By combining a linear colour space transform and advanced multiple regression methodologies it was possible to predict L*a*b* colour data with less than 2.2 colour units of error (CIE 1976). By transforming the red, green and blue colour components into new variables that better reflect the structure of the L*a*b* colour space, a low colour calibration error was immediately achieved (ΔE(CAL) = 14.1). Application of a range of regression models on the data further reduced the colour calibration error substantially (multilinear regression ΔE(CAL) = 5.4; response surface ΔE(CAL) = 2.9; PLSR ΔE(CAL) = 2.6; LASSO regression ΔE(CAL) = 2.1). Only the PLSR models deteriorated substantially under cross validation. The algorithm is adaptable and can be easily recalibrated to any working computer vision system. The algorithm was tested on a typical working laboratory computer vision system and delivered only a very marginal loss of colour information ΔE(CAL) = 2.35. Colour features derived on this system were able to safely discriminate between three classes of ham with 100% correct classification whereas colour features measured on a conventional colourimeter were not. Copyright © 2012 Elsevier Ltd. All rights reserved.

Chromatic VEP in children with congenital colour vision deficiency.

PubMed

Tekavčič Pompe, Manca; Stirn Kranjc, Branka; Brecelj, Jelka

2010-09-01

Visual evoked potentials to chromatic stimulus (cVEP) are believed to selectively test the parvocellular visual pathway which is responsible for processing information about colour. The aim was to evaluate cVEP in children with red-green congenital colour vision deficiency. VEP responses of 15 colour deficient children were compared to 31 children with normal colour vision. An isoluminant red-green stimulus composed of horizontal gratings was presented in an onset-offset manner. The shape of the waveform was studied, as well as the latency and amplitude of positive (P) and negative (N) waves. cVEP response did not change much with increased age in colour deficient children, whereas normative data showed changes from a predominantly positive to a negative response with increased age. A P wave was present in 87% of colour deficient children (and in 100% of children with normal colour vision), whereas the N wave was absent in a great majority of colour deficient children and was present in 80% of children with normal colour vision. Therefore, the amplitude of the whole response (N-P) decreased linearly with age in colour deficient children, whereas in children with normal colour vision it increased linearly. P wave latency shortened with increased age in both groups. cVEP responses differ in children with congenital colour vision deficiency compared to children with normal colour vision. © 2010 The Authors, Ophthalmic and Physiological Optics © 2010 The College of Optometrists.

Working memory in children and adolescents with Down syndrome: evidence from a colour memory experiment.

PubMed

Laws, Glynis

2002-03-01

This paper reports information on the visual and verbal short-term memory of individuals with Down syndrome. Colour memory in 16 children and adolescents with Down syndrome was compared with that of 16 typically developing children matched for receptive vocabulary. It was suggested that focal colours should be remembered more successfully than non-focal colours on the basis that the former could be remembered using a verbal recoding strategy. However, children with Down syndrome, for whom a deficit in verbal short-term memory makes the use of such a strategy unlikely, should remember focal and non-focal colours equally well. More importantly, if individuals with Down syndrome have more developed visual memory abilities than control children, they should outperform them in recognising non-focal colours. Although the group with Down syndrome demonstrated significantly better Corsi blocks performance than controls, and displayed similar levels of colour knowledge, no advantage for colour memory was found. Non-focal colours were remembered by individuals with Down syndrome as successfully as focal colours but there was no indication of a visual memory advantage over controls. Focal colours were remembered significantly more successfully than non-focal colours by the typically developing children. Their focal colour memory was significantly related to digit span, but only Corsi span was related to focal colour memory in the group with Down syndrome.

The effects of stimulus competition and voluntary attention on colour-graphemic synaesthesia.

PubMed

Rich, Anina N; Mattingley, Jason B

2003-10-06

Colour-graphemic synaesthetes experience vivid colours when reading letters, digits and words. We examined the effect of stimulus competition and attention on these unusual colour experiences in 14 synaesthetes and 14 non-synaesthetic controls. Participants named the colour of hierarchical local-global stimuli in which letters at each level elicited synaesthetic colours that were congruent or incongruent with the display colour. Synaesthetes were significantly slower to name display colours when either level was incongruent than when both levels were congruent. This effect was significantly reduced when synaesthetes focused attention on one level while the congruency of letters at the ignored level was varied. These findings suggest that competition between multiple inducers and mechanisms of voluntary attention influence colour-graphemic synaesthesia.

Whole high-quality light environment for humans and plants

NASA Astrophysics Data System (ADS)

Sharakshane, Anton

2017-11-01

Plants sharing a single light environment on a spaceship with a human being and bearing a decorative function should look as natural and attractive as possible. And consequently they can be illuminated only with white light with a high color rendering index. Can lighting optimized for a human eye be effective and appropriate for plants? Spectrum-based effects have been compared under artificial lighting of plants by high-pressure sodium lamps and general-purpose white LEDs. It has been shown that for the survey sample phytochrome photo-equilibria does not depend significantly on the parameters of white LED light, while the share of phytoactive blue light grows significantly as the color temperature increases. It has been revealed that yield photon flux is proportional to luminous efficacy and increases as the color temperature decreases, general color rendering index Ra and the special color rendering index R14 (green leaf) increase. General-purpose white LED lamps with a color temperature of 2700 K, Ra > 90 and luminous efficacy of 100 lm/W are as efficient as the best high-pressure sodium lamps, and at a higher luminous efficacy their yield photon flux per joule is even bigger in proportion. Here we show that demand for high color rendering white LED light is not contradictory to the agro-technical objectives.

An exploratory study of linguistic-colour associations across languages in multilingual synaesthetes.

PubMed

Barnett, Kylie J; Feeney, Joanne; Gormley, Michael; Newell, Fiona N

2009-07-01

In one of the most common forms of synaesthesia, linguistic-colour synaesthesia, colour is induced by stimuli such as numbers, letters, days of the week, and months of the year. It is not clear, however, whether linguistic-colour synaesthesia is determined more by higher level semantic information--that is, word meaning--or by lower level grapheme or phoneme structure. To explore this issue, we tested whether colour is consistently induced by grapheme or phoneme form or word meaning in bilingual and trilingual linguistic-colour synaesthetes. We reasoned that if the induced colour was related to word meaning, rather than to the acoustic or visual properties of the words, then the induced colours would remain consistent across languages. We found that colours were not consistently related to word meaning across languages. Instead, induced colours were more related to form properties of the word across languages, particularly visual structure. However, the type of inducing stimulus influenced specific colour associations. For example, colours to months of the year were more consistent across languages than were colours to numbers or days of the week. Furthermore, the effect of inducing stimuli was also associated with the age of acquisition of additional languages. Our findings are discussed with reference to a critical period in language acquisition on synaesthesia.

Why do seals have cones? Behavioural evidence for colour-blindness in harbour seals.

PubMed

Scholtyssek, Christine; Kelber, Almut; Dehnhardt, Guido

2015-03-01

All seals and cetaceans have lost at least one of two ancestral cone classes and should therefore be colour-blind. Nevertheless, earlier studies showed that these marine mammals can discriminate colours and a colour vision mechanism has been proposed which contrasts signals from cones and rods. However, these earlier studies underestimated the brightness discrimination abilities of these animals, so that they could have discriminated colours using brightness only. Using a psychophysical discrimination experiment, we showed that a harbour seal can solve a colour discrimination task by means of brightness discrimination alone. Performing a series of experiments in which two harbour seals had to discriminate the brightness of colours, we also found strong evidence for purely scotopic (rod-based) vision at light levels that lead to mesopic (rod-cone-based) vision in other mammals. This finding speaks against rod-cone-based colour vision in harbour seals. To test for colour-blindness, we used a cognitive approach involving a harbour seal trained to use a concept of same and different. We tested this seal with pairs of isoluminant stimuli that were either same or different in colour. If the seal had perceived colour, it would have responded to colour differences between stimuli. However, the seal responded with "same", providing strong evidence for colour-blindness.

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

Scalable Multi-Platform Distribution of Spatial 3d Contents

NASA Astrophysics Data System (ADS)

Klimke, J.; Hagedorn, B.; Döllner, J.

2013-09-01

Virtual 3D city models provide powerful user interfaces for communication of 2D and 3D geoinformation. Providing high quality visualization of massive 3D geoinformation in a scalable, fast, and cost efficient manner is still a challenging task. Especially for mobile and web-based system environments, software and hardware configurations of target systems differ significantly. This makes it hard to provide fast, visually appealing renderings of 3D data throughout a variety of platforms and devices. Current mobile or web-based solutions for 3D visualization usually require raw 3D scene data such as triangle meshes together with textures delivered from server to client, what makes them strongly limited in terms of size and complexity of the models they can handle. In this paper, we introduce a new approach for provisioning of massive, virtual 3D city models on different platforms namely web browsers, smartphones or tablets, by means of an interactive map assembled from artificial oblique image tiles. The key concept is to synthesize such images of a virtual 3D city model by a 3D rendering service in a preprocessing step. This service encapsulates model handling and 3D rendering techniques for high quality visualization of massive 3D models. By generating image tiles using this service, the 3D rendering process is shifted from the client side, which provides major advantages: (a) The complexity of the 3D city model data is decoupled from data transfer complexity (b) the implementation of client applications is simplified significantly as 3D rendering is encapsulated on server side (c) 3D city models can be easily deployed for and used by a large number of concurrent users, leading to a high degree of scalability of the overall approach. All core 3D rendering techniques are performed on a dedicated 3D rendering server, and thin-client applications can be compactly implemented for various devices and platforms.

Plasmonic colour generation

NASA Astrophysics Data System (ADS)

Kristensen, Anders; Yang, Joel K. W.; Bozhevolnyi, Sergey I.; Link, Stephan; Nordlander, Peter; Halas, Naomi J.; Mortensen, N. Asger

2017-01-01

Plasmonic colours are structural colours that emerge from resonant interactions between light and metallic nanostructures. The engineering of plasmonic colours is a promising, rapidly emerging research field that could have a large technological impact. We highlight basic properties of plasmonic colours and recent nanofabrication developments, comparing technology-performance indicators for traditional and nanophotonic colour technologies. The structures of interest include diffraction gratings, nanoaperture arrays, thin films, and multilayers and structures that support Mie resonances and whispering-gallery modes. We discuss plasmonic colour nanotechnology based on localized surface plasmon resonances, such as gap plasmons and hybridized disk-hole plasmons, which allow for colour printing with sub-diffraction resolution. We also address a range of fabrication approaches that enable large-area printing and nanoscale lithography compatible with complementary metal-oxide semiconductor technologies, including nanoimprint lithography and self-assembly. Finally, we review recent developments in dynamically reconfigurable plasmonic colours and in the laser-induced post-processing of plasmonic colour surfaces.

The effect of colour on children's cognitive performance.

PubMed

Brooker, Alice; Franklin, Anna

2016-06-01

The presence of red appears to hamper adults' cognitive performance relative to other colours (see Elliot & Maier, 2014, Ann. Rev. Psychol. 65, 95). Here, we investigate whether colour affects cognitive performance in 8- and 9-year-olds. Children completed a battery of tasks once in the presence of a coloured screen that was one of eight colours and once in the presence of a grey screen. Performance was assessed for each colour relative to the grey baseline, and differences across colours were compared. We find a significant difference in performance across colours, with significantly worse performance in the presence of red than grey. The effect of colour did not significantly interact with task. The findings suggest that colour can affect children's cognitive performance and that there is a detrimental effect of red. Findings are related to the adult literature and implications for educational contexts are discussed. © 2015 The British Psychological Society.

Immersive Molecular Visualization with Omnidirectional Stereoscopic Ray Tracing and Remote Rendering

PubMed Central

Stone, John E.; Sherman, William R.; Schulten, Klaus

2016-01-01

Immersive molecular visualization provides the viewer with intuitive perception of complex structures and spatial relationships that are of critical interest to structural biologists. The recent availability of commodity head mounted displays (HMDs) provides a compelling opportunity for widespread adoption of immersive visualization by molecular scientists, but HMDs pose additional challenges due to the need for low-latency, high-frame-rate rendering. State-of-the-art molecular dynamics simulations produce terabytes of data that can be impractical to transfer from remote supercomputers, necessitating routine use of remote visualization. Hardware-accelerated video encoding has profoundly increased frame rates and image resolution for remote visualization, however round-trip network latencies would cause simulator sickness when using HMDs. We present a novel two-phase rendering approach that overcomes network latencies with the combination of omnidirectional stereoscopic progressive ray tracing and high performance rasterization, and its implementation within VMD, a widely used molecular visualization and analysis tool. The new rendering approach enables immersive molecular visualization with rendering techniques such as shadows, ambient occlusion lighting, depth-of-field, and high quality transparency, that are particularly helpful for the study of large biomolecular complexes. We describe ray tracing algorithms that are used to optimize interactivity and quality, and we report key performance metrics of the system. The new techniques can also benefit many other application domains. PMID:27747138

Effect of colour of drugs: systematic review of perceived effect of drugs and of their effectiveness.

PubMed

de Craen, A J; Roos, P J; de Vries, A L; Kleijnen, J

To assess the impact of the colour of a drug's formulation on its perceived effect and its effectiveness and to examine whether antidepressant drugs available in the Netherlands are different in colour from hypnotic, sedative, and anxiolytic drugs. Systematic review of 12 published studies. Six studies examined the perceived action of different coloured drugs and six the influence of the colour of a drug on its effectiveness. The colours of samples of 49 drugs affecting the central nervous system were assessed using a colour atlas. Perceived stimulant action versus perceived depressant action of colour of drugs; the trials that assessed the effect of drugs in different colours were done in patients with different diseases and had different outcome measures. The studies on perceived action of coloured drugs showed that red, yellow, and orange are associated with a stimulant effect, while blue and green are related to a tranquillising effect. The trials that assessed the impact of the colour of drugs on their effectiveness showed inconsistent differences between colours. The quality of the methods of these trials was variable. Hypnotic, sedative, and anxiolytic drugs were more likely than antidepressants to be green, blue, or purple. Colours affect the perceived action of a drug and seem to influence the effectiveness of a drug. Moreover, a relation exists between the colouring of drugs that affect the central nervous system and the indications for which they are used. Research contributing to a better understanding of the effect of the colour of drugs is warranted.

The effect of colour congruency on shape discriminations of novel objects.

PubMed

Nicholson, Karen G; Humphrey, G Keith

2004-01-01

Although visual object recognition is primarily shape driven, colour assists the recognition of some objects. It is unclear, however, just how colour information is coded with respect to shape in long-term memory and how the availability of colour in the visual image facilitates object recognition. We examined the role of colour in the recognition of novel, 3-D objects by manipulating the congruency of object colour across the study and test phases, using an old/new shape-identification task. In experiment 1, we found that participants were faster at correctly identifying old objects on the basis of shape information when these objects were presented in their original colour, rather than in a different colour. In experiments 2 and 3, we found that participants were faster at correctly identifying old objects on the basis of shape information when these objects were presented with their original part-colour conjunctions, rather than in different or in reversed part-colour conjunctions. In experiment 4, we found that participants were quite poor at the verbal recall of part-colour conjunctions for correctly identified old objects, presented as grey-scale images at test. In experiment 5, we found that participants were significantly slower at correctly identifying old objects when object colour was incongruent across study and test, than when background colour was incongruent across study and test. The results of these experiments suggest that both shape and colour information are stored as part of the long-term representation of these novel objects. Results are discussed in terms of how colour might be coded with respect to shape in stored object representations.

Benthic macroinvertebrate community structure in 20 streams of varying pH and humic content.

PubMed

Kullberg, A

1992-01-01

The structure of stream benthic macroinvertebrate communities in relation to pH and humic content was studied in 20 second and third-order forest streams in southern Sweden. Streams varied in pH from 4.2 to 8.0, and in humic content from a colour of 5 to 1200 mg Pt litre(-1). There was a positive relationship between pH and species richness, with a discontinuity occurring at pH approximately 5.7. At pH > 5.7, species richness decreased with increasing colour. At pH < 5.7 there was a positive correlation between species richness and humic concentration up to a colour of about 200-300 mg Pt litre(-1). this may be explained by high concentrations, 0.4-0.9 mg litre(-1), of labile monomeric Al occurring in the low coloured acid streams. In streams with a colour > 200 mg Pt litre(-1) labile monomeric Al was less than 0.2 mg litre(-1). There was no significant change in species richness above this threshold, but a shift in species composition towards a dominance of Plecoptera and Chironomidae. This threshold model seems to explain the observed differences in stream benthic community structure better than a simple linear relationship with pH or humic content.

A missense mutation in melanocortin 1 receptor is associated with the red coat colour in donkeys.

PubMed

Abitbol, M; Legrand, R; Tiret, L

2014-12-01

The seven donkey breeds recognised by the French studbook are characterised by few coat colours: black, bay and grey. Normand bay donkeys seldom give birth to red foals, a colour more commonly seen and recognised in American miniature donkeys. Red resembles the equine chestnut colour, previously attributed to a mutation in the melanocortin 1 receptor gene (MC1R). We used a panel of 124 donkeys to identify a recessive missense c.629T>C variant in MC1R that showed a perfect association with the red coat colour. This variant leads to a methionine to threonine substitution at position 210 in the protein. We showed that methionine 210 is highly conserved among vertebrate melanocortin receptors. Previous in silico and in vitro analyses predicted this residue to lie within a functional site. Our in vivo results emphasised the pivotal role played by this residue, the alteration of which yielded a phenotype fully compatible with a loss of function of MC1R. We thus propose to name the c.629T>C allele in donkeys the e allele, which further enlarges the panel of recessive MC1R loss-of-function alleles described in animals and humans. © 2014 Stichting International Foundation for Animal Genetics.

VizieR Online Data Catalog: 12um ISOCAM survey of the ESO-Sculptor field (Seymour+, 2007)

NASA Astrophysics Data System (ADS)

Seymour, N.; Rocca-Volmerange, B.; de Lapparent, V.

2007-11-01

We present a detailed reduction of a mid-infrared 12um (LW10 filter) ISOCAM open time observation performed on the ESO-Sculptor Survey field (Arnouts et al., 1997A&AS..124..163A). A complete catalogue of 142 sources (120 galaxies and 22 stars), detected with high significance (equivalent to 5{sigma}), is presented above an integrated flux density of 0.31mJy. Star/galaxy separation is performed by a detailed study of colour-colour diagrams. The catalogue is complete to 1mJy and, below this flux density, the incompleteness is corrected using two independent methods. The first method uses stars and the second uses optical counterparts of the ISOCAM galaxies; these methods yield consistent results. We also apply an empirical flux density calibration using stars in the field. For each star, the 12um flux density is derived by fitting optical colours from a multi-band {chi}2 to stellar templates (BaSel-2.0) and using empirical optical-IR colour-colour relations. This article is a companion analysis to our 2007 paper (Rocca-Volmerange et al. 2007A&A...475..801R) where the 12um faint galaxy counts are presented and analysed per galaxy type with the evolutionary code PEGASE.3. (1 data file).

Association of cigarette smoking with skin colour in Japanese women.

PubMed

Tamai, Yuya; Tsuji, Michiko; Wada, Keiko; Nakamura, Kozue; Hayashi, Makoto; Takeda, Noriyuki; Yasuda, Keigo; Nagata, Chisato

2014-05-01

Having a lighter skin tone is highly valued among many Asian women. If skin colour is affected by smoking, women may be motivated to avoid tobacco or quit smoking. The present study examined the association of tobacco smoking with skin colour in Japanese women. Information on smoking habits was obtained through a self-administered questionnaire completed by 939 Japanese women aged 20-74 in Gifu, Japan, during 2003-2006. Skin colour was examined on the inner side of the upper and lower arm and on the forehead using a Mexameter device (a narrow-band reflective spectrophotometer), which expressed results as a melanin index and erythema index. Current smokers had higher melanin indices than never-smokers and former smokers for all measured sites. The number of cigarettes smoked per day, the years of smoking and pack-years were significantly positively associated with melanin indices for all measured sites after adjustments for age, body mass index, lifetime sun exposure, and room temperature and humidity. Smoking was also significantly associated with erythema indices on the inner upper and lower arms. These data suggest that smoking is associated with a darker skin colour. If our findings are confirmed by further studies, they could be used in antismoking campaigns or by smoking cessation services.

Egg colour matching in an African cuckoo, as revealed by ultraviolet-visible reflectance spectrophotometry.

PubMed Central

Cherry, M I; Bennett, A T

2001-01-01

Despite major differences between human and avian colour vision, previous studies of cuckoo egg mimicry have used human colour vision (or standards based thereon) to assess colour matching. Using ultraviolet-visible reflectance spectrophotometry (300-700 nm), we measured museum collections of eggs of the red-chested cuckoo and its hosts. The first three principal components explained more than 99% of the variance in spectra, and measures of cuckoo host egg similarity derived from these transformations were compared with measures of cuckoo host egg similarity estimated by human observers unaware of the hypotheses we were testing. Monte Carlo methods were used to simulate laying of cuckoo eggs at random in nests. Results showed that host and cuckoo eggs were very highly matched for an ultraviolet versus greenness component, which was not detected by humans. Furthermore, whereas cuckoo and host were dissimilar in achromatic brightness, humans did not detect this difference. Our study thus reveals aspects of cuckoo-host egg colour matching which have hitherto not been described. These results suggest subtleties and complexities in the evolution of host-cuckoo egg mimicry that were not previously suspected. Our results also have the potential to explain the longstanding paradox that some host species accept cuckoo eggs that are non-mimetic to the human eye. PMID:11297172

Task probability and report of feature information: what you know about what you 'see' depends on what you expect to need.

PubMed

Pilling, Michael; Gellatly, Angus

2013-07-01

We investigated the influence of dimensional set on report of object feature information using an immediate memory probe task. Participants viewed displays containing up to 36 coloured geometric shapes which were presented for several hundred milliseconds before one item was abruptly occluded by a probe. A cue presented simultaneously with the probe instructed participants to report either about the colour or shape of the probe item. A dimensional set towards the colour or shape of the presented items was induced by manipulating task probability - the relative probability with which the two feature dimensions required report. This was done across two participant groups: One group was given trials where there was a higher report probability of colour, the other a higher report probability of shape. Two experiments showed that features were reported most accurately when they were of high task probability, though in both cases the effect was largely driven by the colour dimension. Importantly the task probability effect did not interact with display set size. This is interpreted as tentative evidence that this manipulation influences feature processing in a global manner and at a stage prior to visual short term memory. Copyright © 2013 Elsevier B.V. All rights reserved.

The colours of humanity: the evolution of pigmentation in the human lineage.

PubMed

Jablonski, Nina G; Chaplin, George

2017-07-05

Humans are a colourful species of primate, with human skin, hair and eye coloration having been influenced by a great variety of evolutionary forces throughout prehistory. Functionally naked skin has been the physical interface between the physical environment and the human body for most of the history of the genus Homo , and hence skin coloration has been under intense natural selection. From an original condition of protective, dark, eumelanin-enriched coloration in early tropical-dwelling Homo and Homo sapiens , loss of melanin pigmentation occurred under natural selection as Homo sapiens dispersed into non-tropical latitudes of Africa and Eurasia. Genes responsible for skin, hair and eye coloration appear to have been affected significantly by population bottlenecks in the course of Homo sapiens dispersals. Because specific skin colour phenotypes can be created by different combinations of skin colour-associated genetic markers, loss of genetic variability due to genetic drift appears to have had negligible effects on the highly redundant genetic 'palette' for the skin colour. This does not appear to have been the case for hair and eye coloration, however, and these traits appear to have been more strongly influenced by genetic drift and, possibly, sexual selection.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

Combined anaerobic digestion and photocatalytic treatment of distillery effluent in fluidized bed reactors focusing on energy conservation.

PubMed

Apollo, Seth; Aoyi, Ochieng

2016-09-01

Anaerobic digestion (AD) can remove substantial amount of organic load when applied in treating distillery effluent but it is ineffective in colour reduction. Conversely, photodegradation is effective in colour reduction but has high energy requirement. A study on the synergy of a combined AD and ultra violet (UV) photodegradation treatment of distillery effluent was carried out in fluidized bed reactors to evaluate pollution reduction and energy utilization efficiencies. The combined process improved colour removal from 41% to 85% compared to that of AD employed as a stand-alone process. An overall corresponding total organic carbon (TOC) reduction of 83% was achieved. The bioenergy production by the AD step was 14.2 kJ/g total organic carbon (TOC) biodegraded while UV lamp energy consumption was 0.9 kJ/mg TOC, corresponding to up to 100% colour removal. Electrical energy per order analysis for the photodegradation process showed that the bioenergy produced was 20% of that required by the UV lamp to photodegrade 1 m(3) of undiluted pre-AD treated effluent up to 75% colour reduction. It was concluded that a combined AD-UV system for treatment of distillery effluent is effective in organic load removal and can be operated at a reduced cost.

Colour Perception in ADHD

ERIC Educational Resources Information Center

Banaschewski, Tobias; Ruppert, Sinje; Tannock, Rosemary; Albrecht, Bjorn; Becker, Andreas; Uebel, Henrik; Sergeant, Joseph A.; Rothenberger, Aribert

2006-01-01

Attention-deficit/hyperactivity disorder (ADHD) is associated with unexplained impairments on speeded naming of coloured stimuli. These deficits may reflect hypofunctioning retinal dopaminergic mechanisms impairing particularly blue-yellow colour discrimination. Colour perception and rapid colour naming ability were investigated in 14 children…

A Handheld LED Coloured-Light Mixer for Students to Learn Collaboratively the Primary Colours of Light

ERIC Educational Resources Information Center

Nopparatjamjomras, Suchai; Chitaree, Ratchapak; Panijpan, Bhinyo

2009-01-01

To overcome students' inaccurate prior knowledge on primary additive colours, a coloured-light mixer has been constructed to enable students to observe directly the colours produced and reach the conclusion by themselves that the three primary colours of light are red, green, and blue (NOT red, yellow, and blue). Three closely packed tiny…

The "Human Colour" Crayon: Investigating the Attitudes and Perceptions of Learners Regarding Race and Skin Colour

ERIC Educational Resources Information Center

Alexander, Neeske; Costandius, Elmarie

2017-01-01

Some coloured and black learners in South Africa use a light orange or pink crayon to represent themselves in art. Many learners name this colour "human colour" or "skin colour". This is troublesome, because it could reflect exclusionary ways of representing race in images and language. This case study, conducted with two…

Colour image segmentation using unsupervised clustering technique for acute leukemia images

NASA Astrophysics Data System (ADS)

Halim, N. H. Abd; Mashor, M. Y.; Nasir, A. S. Abdul; Mustafa, N.; Hassan, R.

2015-05-01

Colour image segmentation has becoming more popular for computer vision due to its important process in most medical analysis tasks. This paper proposes comparison between different colour components of RGB(red, green, blue) and HSI (hue, saturation, intensity) colour models that will be used in order to segment the acute leukemia images. First, partial contrast stretching is applied on leukemia images to increase the visual aspect of the blast cells. Then, an unsupervised moving k-means clustering algorithm is applied on the various colour components of RGB and HSI colour models for the purpose of segmentation of blast cells from the red blood cells and background regions in leukemia image. Different colour components of RGB and HSI colour models have been analyzed in order to identify the colour component that can give the good segmentation performance. The segmented images are then processed using median filter and region growing technique to reduce noise and smooth the images. The results show that segmentation using saturation component of HSI colour model has proven to be the best in segmenting nucleus of the blast cells in acute leukemia image as compared to the other colour components of RGB and HSI colour models.

Colour preferences and colour vision in poultry chicks.

PubMed

Ham, A D; Osorio, D

2007-08-22

The dramatic colours of biological communication signals raise questions about how animals perceive suprathreshold colour differences, and there are long-standing questions about colour preferences and colour categorization by non-human species. This study investigates preferences of foraging poultry chicks (Gallus gallus) as they peck at coloured objects. Work on colour recognition often deals with responses to monochromatic lights and how animals divide the spectrum. We used complementary colours, where the intermediate is grey, and related the chicks' choices to three models of the factors that may affect the attractiveness. Two models assume that attractiveness is determined by a metric based on the colour discrimination threshold either (i) by chromatic contrast against the background or (ii) relative to an internal standard. An alternative third model is that categorization is important. We tested newly hatched and 9-day-old chicks with four pairs of (avian) complementary colours, which were orange, blue, red and green for humans. Chromatic contrast was more relevant to newly hatched chicks than to 9-day-old birds, but in neither case could contrast alone account for preferences; especially for orange over blue. For older chicks, there is evidence for categorization of complementary colours, with a boundary at grey.

Key indicator tools for shallow slope failure assessment using soil chemical property signatures and soil colour variables.

PubMed

Othman, Rashidi; Hasni, Shah Irani; Baharuddin, Zainul Mukrim; Hashim, Khairusy Syakirin Has-Yun; Mahamod, Lukman Hakim

2017-10-01

Slope failure has become a major concern in Malaysia due to the rapid development and urbanisation in the country. It poses severe threats to any highway construction industry, residential areas, natural resources and tourism activities. The extent of damages that resulted from this catastrophe can be lessened if a long-term early warning system to predict landslide prone areas is implemented. Thus, this study aims to characterise the relationship between Oxisols properties and soil colour variables to be manipulated as key indicators to forecast shallow slope failure. The concentration of each soil property in slope soil was evaluated from two different localities that consist of 120 soil samples from stable and unstable slopes located along the North-South Highway (PLUS) and East-West Highway (LPT). Analysis of variance established highly significant difference (P < 0.0001) between the locations, the total organic carbon (TOC), soil pH, cation exchange capacity (CEC), soil texture, soil chromaticity and all combinations of interactions. The overall CIELAB analysis leads to the conclusion that the CIELAB variables lightness L*, c* (Chroma) and h* (Hue) provide the most information about soil colour and other related soil properties. With regard to the relationship between colour variables and soil properties, the analysis detected that soil texture, organic carbon, iron oxide and aluminium concentration were the key factors that strongly correlate with soil colour variables at the studied area. Indicators that could be used to predict shallow slope failure were high value of L*(62), low values of c* (20) and h* (66), low concentration of iron (53 mg kg -1 ) and aluminium oxide (37 mg kg -1 ), low soil TOC (0.5%), low CEC (3.6 cmol/kg), slightly acidic soil pH (4.9), high amount of sand fraction (68%) and low amount of clay fraction (20%).

Single Marker and Haplotype-Based Association Analysis of Semolina and Pasta Colour in Elite Durum Wheat Breeding Lines Using a High-Density Consensus Map.

PubMed

N'Diaye, Amidou; Haile, Jemanesh K; Cory, Aron T; Clarke, Fran R; Clarke, John M; Knox, Ron E; Pozniak, Curtis J

2017-01-01

Association mapping is usually performed by testing the correlation between a single marker and phenotypes. However, because patterns of variation within genomes are inherited as blocks, clustering markers into haplotypes for genome-wide scans could be a worthwhile approach to improve statistical power to detect associations. The availability of high-density molecular data allows the possibility to assess the potential of both approaches to identify marker-trait associations in durum wheat. In the present study, we used single marker- and haplotype-based approaches to identify loci associated with semolina and pasta colour in durum wheat, the main objective being to evaluate the potential benefits of haplotype-based analysis for identifying quantitative trait loci. One hundred sixty-nine durum lines were genotyped using the Illumina 90K Infinium iSelect assay, and 12,234 polymorphic single nucleotide polymorphism (SNP) markers were generated and used to assess the population structure and the linkage disequilibrium (LD) patterns. A total of 8,581 SNPs previously localized to a high-density consensus map were clustered into 406 haplotype blocks based on the average LD distance of 5.3 cM. Combining multiple SNPs into haplotype blocks increased the average polymorphism information content (PIC) from 0.27 per SNP to 0.50 per haplotype. The haplotype-based analysis identified 12 loci associated with grain pigment colour traits, including the five loci identified by the single marker-based analysis. Furthermore, the haplotype-based analysis resulted in an increase of the phenotypic variance explained (50.4% on average) and the allelic effect (33.7% on average) when compared to single marker analysis. The presence of multiple allelic combinations within each haplotype locus offers potential for screening the most favorable haplotype series and may facilitate marker-assisted selection of grain pigment colour in durum wheat. These results suggest a benefit of haplotype-based analysis over single marker analysis to detect loci associated with colour traits in durum wheat.

Seasonal variation in coat characteristics, tick loads, cortisol levels, some physiological parameters and temperature humidity index on Nguni cows raised in low- and high-input farms

NASA Astrophysics Data System (ADS)

Katiyatiya, C. L. F.; Muchenje, V.; Mushunje, A.

2015-06-01

Seasonal variations in hair length, tick loads, cortisol levels, haematological parameters (HP) and temperature humidity index (THI) in Nguni cows of different colours raised in two low-input farms, and a commercial stud was determined. The sites were chosen based on their production systems, climatic characteristics and geographical locations. Zazulwana and Komga are low-input, humid-coastal areas, while Honeydale is a high-input, dry-inland Nguni stud farm. A total of 103 cows, grouped according to parity, location and coat colour, were used in the study. The effects of location, coat colour, hair length and season were used to determine tick loads on different body parts, cortisol levels and HP in blood from Nguni cows. Highest tick loads were recorded under the tail and the lowest on the head of each of the animals ( P < 0.05). Zazulwana cows recorded the highest tick loads under the tails of all the cows used in the study from the three farms ( P < 0.05). High tick loads were recorded for cows with long hairs. Hair lengths were longest during the winter season in the coastal areas of Zazulwana and Honeydale ( P < 0.05). White and brown-white patched cows had significantly longer ( P < 0.05) hair strands than those having a combination of red, black and white colour. Cortisol and THI were significantly lower ( P < 0.05) in summer season. Red blood cells, haematoglobin, haematocrit, mean cell volumes, white blood cells, neutrophils, lymphocytes, eosinophils and basophils were significantly different ( P < 0.05) as some associated with age across all seasons and correlated to THI. It was concluded that the location, coat colour and season had effects on hair length, cortisol levels, THI, HP and tick loads on different body parts and heat stress in Nguni cows.

Developmental validation of the IrisPlex system: determination of blue and brown iris colour for forensic intelligence.

PubMed

Walsh, Susan; Lindenbergh, Alexander; Zuniga, Sofia B; Sijen, Titia; de Knijff, Peter; Kayser, Manfred; Ballantyne, Kaye N

2011-11-01

The IrisPlex system consists of a highly sensitive multiplex genotyping assay together with a statistical prediction model, providing users with the ability to predict blue and brown human eye colour from DNA samples with over 90% precision. This 'DNA intelligence' system is expected to aid police investigations by providing phenotypic information on unknown individuals when conventional DNA profiling is not informative. Falling within the new area of forensic DNA phenotyping, this paper describes the developmental validation of the IrisPlex assay following the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines for the application of DNA-based eye colour prediction to forensic casework. The IrisPlex assay produces complete SNP genotypes with only 31pg of DNA, approximately six human diploid cell equivalents, and is therefore more sensitive than commercial STR kits currently used in forensics. Species testing revealed human and primate specificity for a complete SNP profile. The assay is capable of producing accurate results from simulated casework samples such as blood, semen, saliva, hair, and trace DNA samples, including extremely low quantity samples. Due to its design, it can also produce full profiles with highly degraded samples often found in forensic casework. Concordance testing between three independent laboratories displayed reproducible results of consistent levels on varying types of simulated casework samples. With such high levels of sensitivity, specificity, consistency and reliability, this genotyping assay, as a core part of the IrisPlex system, operates in accordance with SWGDAM guidelines. Furthermore, as we demonstrated previously, the IrisPlex eye colour prediction system provides reliable results without the need for knowledge on the bio-geographic ancestry of the sample donor. Hence, the IrisPlex system, with its model-based prediction probability estimation of blue and brown human eye colour, represents a useful tool for immediate application in accredited forensic laboratories, to be used for forensic intelligence in tracing unknown individuals from crime scene samples. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Colour Terms Affect Detection of Colour and Colour-Associated Objects Suppressed from Visual Awareness

PubMed Central

Forder, Lewis; Taylor, Olivia; Mankin, Helen; Scott, Ryan B.; Franklin, Anna

2016-01-01

The idea that language can affect how we see the world continues to create controversy. A potentially important study in this field has shown that when an object is suppressed from visual awareness using continuous flash suppression (a form of binocular rivalry), detection of the object is differently affected by a preceding word prime depending on whether the prime matches or does not match the object. This may suggest that language can affect early stages of vision. We replicated this paradigm and further investigated whether colour terms likewise influence the detection of colours or colour-associated object images suppressed from visual awareness by continuous flash suppression. This method presents rapidly changing visual noise to one eye while the target stimulus is presented to the other. It has been shown to delay conscious perception of a target for up to several minutes. In Experiment 1 we presented greyscale photos of objects. They were either preceded by a congruent object label, an incongruent label, or white noise. Detection sensitivity (d’) and hit rates were significantly poorer for suppressed objects preceded by an incongruent label compared to a congruent label or noise. In Experiment 2, targets were coloured discs preceded by a colour term. Detection sensitivity was significantly worse for suppressed colour patches preceded by an incongruent colour term as compared to a congruent term or white noise. In Experiment 3 targets were suppressed greyscale object images preceded by an auditory presentation of a colour term. On congruent trials the colour term matched the object’s stereotypical colour and on incongruent trials the colour term mismatched. Detection sensitivity was significantly poorer on incongruent trials than congruent trials. Overall, these findings suggest that colour terms affect awareness of coloured stimuli and colour- associated objects, and provide new evidence for language-perception interaction in the brain. PMID:27023274

Colour Terms Affect Detection of Colour and Colour-Associated Objects Suppressed from Visual Awareness.

PubMed

Forder, Lewis; Taylor, Olivia; Mankin, Helen; Scott, Ryan B; Franklin, Anna

2016-01-01

The idea that language can affect how we see the world continues to create controversy. A potentially important study in this field has shown that when an object is suppressed from visual awareness using continuous flash suppression (a form of binocular rivalry), detection of the object is differently affected by a preceding word prime depending on whether the prime matches or does not match the object. This may suggest that language can affect early stages of vision. We replicated this paradigm and further investigated whether colour terms likewise influence the detection of colours or colour-associated object images suppressed from visual awareness by continuous flash suppression. This method presents rapidly changing visual noise to one eye while the target stimulus is presented to the other. It has been shown to delay conscious perception of a target for up to several minutes. In Experiment 1 we presented greyscale photos of objects. They were either preceded by a congruent object label, an incongruent label, or white noise. Detection sensitivity (d') and hit rates were significantly poorer for suppressed objects preceded by an incongruent label compared to a congruent label or noise. In Experiment 2, targets were coloured discs preceded by a colour term. Detection sensitivity was significantly worse for suppressed colour patches preceded by an incongruent colour term as compared to a congruent term or white noise. In Experiment 3 targets were suppressed greyscale object images preceded by an auditory presentation of a colour term. On congruent trials the colour term matched the object's stereotypical colour and on incongruent trials the colour term mismatched. Detection sensitivity was significantly poorer on incongruent trials than congruent trials. Overall, these findings suggest that colour terms affect awareness of coloured stimuli and colour- associated objects, and provide new evidence for language-perception interaction in the brain.

The correlation between radiative surface defect states and high color rendering index from ZnO nanotubes

PubMed Central

2011-01-01

Combined surface, structural and opto-electrical investigations are drawn from the chemically fashioned ZnO nanotubes and its heterostructure with p-GaN film. A strong correlation has been found between the formation of radiative surface defect states in the nanotubes and the pure cool white light possessing averaged eight color rendering index value of 96 with appropriate color temperature. Highly important deep-red color index value has been realized > 95 which has the capability to render and reproduce natural and vivid colors accurately. Diverse types of deep defect states and their relative contribution to the corresponding wavelengths in the broad emission band is suggested. PMID:21878100

Lipid oxidation in minced beef meat with added Krebs cycle substrates to stabilise colour.

PubMed

Yi, G; Grabež, V; Bjelanovic, M; Slinde, E; Olsen, K; Langsrud, O; Phung, V T; Haug, A; Oostindjer, M; Egelandsdal, B

2015-11-15

Krebs cycle substrates (KCS) can stabilise the colour of packaged meat by oxygen reduction. This study tested whether this reduction releases reactive oxygen species that may lead to lipid oxidation in minced meat under two different storage conditions. KCS combinations of succinate and glutamate increased peroxide forming potential (PFP, 1.18-1.32 mmol peroxides/kg mince) and thiobarbituric acid reactive substances (TBARS, 0.30-0.38 mg malondialdehyde (MDA) equivalents/kg mince) under low oxygen storage conditions. Both succinate and glutamate were metabolised. Moreover, under high oxygen (75%) storage conditions, KCS combinations of glutamate, citrate and malate increased PFP (from 1.22 to 1.29 mmol peroxides/kg) and TBARS (from 0.37 to 0.40 mg MDA equivalents/kg mince). Only glutamate was metabolised. The KCS combinations that were added to stabilise colour were metabolised during storage, and acted as pro-oxidants that promoted lipid oxidation in both high and low oxygen conditions. Copyright © 2015. Published by Elsevier Ltd.

Luminescence and luminescence quenching of highly efficient Y2Mo4O15:Eu3+ phosphors and ceramics

PubMed Central

Janulevicius, Matas; Marmokas, Paulius; Misevicius, Martynas; Grigorjevaite, Julija; Mikoliunaite, Lina; Sakirzanovas, Simas; Katelnikovas, Arturas

2016-01-01

A good LED phosphor must possess strong enough absorption, high quantum yields, colour purity, and quenching temperatures. Our synthesized Y2Mo4O15:Eu3+ phosphors possess all of these properties. Excitation of these materials with near-UV or blue radiation yields bright red emission and the colour coordinates are relatively stable upon temperature increase. Furthermore, samples doped with 50% Eu3+ showed quantum yields up to 85%, what is suitable for commercial application. Temperature dependent emission spectra revealed that heavily Eu3+ doped phosphors possess stable emission up to 400 K and lose half of the efficiency only at 515 K. In addition, ceramic disks of Y2Mo4O15:75%Eu3+ phosphor with thickness of 0.71 and 0.98 mm were prepared and it turned out that they efficiently convert radiation of 375 and 400 nm LEDs to the red light, whereas combination with 455 nm LED yields purple colour. PMID:27180941

Luminescence and luminescence quenching of highly efficient Y2Mo4O15:Eu(3+) phosphors and ceramics.

PubMed

Janulevicius, Matas; Marmokas, Paulius; Misevicius, Martynas; Grigorjevaite, Julija; Mikoliunaite, Lina; Sakirzanovas, Simas; Katelnikovas, Arturas

2016-05-16

A good LED phosphor must possess strong enough absorption, high quantum yields, colour purity, and quenching temperatures. Our synthesized Y2Mo4O15:Eu(3+) phosphors possess all of these properties. Excitation of these materials with near-UV or blue radiation yields bright red emission and the colour coordinates are relatively stable upon temperature increase. Furthermore, samples doped with 50% Eu(3+) showed quantum yields up to 85%, what is suitable for commercial application. Temperature dependent emission spectra revealed that heavily Eu(3+) doped phosphors possess stable emission up to 400 K and lose half of the efficiency only at 515 K. In addition, ceramic disks of Y2Mo4O15:75%Eu(3+) phosphor with thickness of 0.71 and 0.98 mm were prepared and it turned out that they efficiently convert radiation of 375 and 400 nm LEDs to the red light, whereas combination with 455 nm LED yields purple colour.

Follow-up of solar lentigo depigmentation with a retinaldehyde-based cream by clinical evaluation and calibrated colour imaging.

PubMed

Questel, E; Durbise, E; Bardy, A-L; Schmitt, A-M; Josse, G

2015-05-01

To assess an objective method evaluating the effects of a retinaldehyde-based cream (RA-cream) on solar lentigines; 29 women randomly applied RA-cream on lentigines of one hand and a control cream on the other, once daily for 3 months. A specific method enabling a reliable visualisation of the lesions was proposed, using high-magnification colour-calibrated camera imaging. Assessment was performed using clinical evaluation by Physician Global Assessment score and image analysis. Luminance determination on the numeric images was performed either on the basis of 5 independent expert's consensus borders or probability map analysis via an algorithm automatically detecting the pigmented area. Both image analysis methods showed a similar lightening of ΔL* = 2 after a 3-month treatment by RA-cream, in agreement with single-blind clinical evaluation. High-magnification colour-calibrated camera imaging combined with probability map analysis is a fast and precise method to follow lentigo depigmentation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Binding of multiple features in memory by high-functioning adults with autism spectrum disorder.

PubMed

Bowler, Dermot M; Gaigg, Sebastian B; Gardiner, John M

2014-09-01

Diminished episodic memory and diminished use of semantic information to aid recall by individuals with autism spectrum disorder (ASD) are both thought to result from diminished relational binding of elements of complex stimuli. To test this hypothesis, we asked high-functioning adults with ASD and typical comparison participants to study grids in which some cells contained drawings of objects in non-canonical colours. Participants were told at study which features (colour, item, location) would be tested in a later memory test. In a second experiment, participants studied similar grids and were told that they would be tested on object-location or object-colour combinations. Recognition of combinations was significantly diminished in ASD, which survived covarying performance on the Color Trails Test (D'Elia et al. Color trails test. Professional manual. Psychological Assessment Resources, Lutz, 1996), a test of executive difficulties. The findings raise the possibility that medial temporal as well as frontal lobe processes are dysfunctional in ASD.

Specific deficit of colour-colour short-term memory binding in sporadic and familial Alzheimer's disease.

PubMed

Parra, Mario A; Sala, Sergio Della; Abrahams, Sharon; Logie, Robert H; Méndez, Luis Guillermo; Lopera, Francisco

2011-06-01

Short-term memory binding of visual features which are processed across different dimensions (shape-colour) is impaired in sporadic Alzheimer's disease, familial Alzheimer's disease, and in asymptomatic carriers of familial Alzheimer's disease. This study investigated whether Alzheimer's disease also impacts on within-dimension binding processes. The study specifically explored whether visual short-term memory binding of features of the same type (colour-colour) is sensitive to Alzheimer's disease. We used a neuropsychological battery and a short-term memory binding task to assess patients with sporadic Alzheimer's disease (Experiment 1), familial Alzheimer's disease (Experiment 2) due to the mutation E280A of the Presenilin-1 gene and asymptomatic carriers of the mutation. The binding task assessed change detection within arrays of unicoloured objects (Colour Only) or bicoloured objects the colours of which had to be remembered separately (Unbound Colours) or together (Bound Colours). Performance on the Bound Colours condition (1) explained the largest proportion of variance between patients (sporadic and familial Alzheimer's disease), (2) combined more sensitivity and specificity for the disease than other more traditional neuropsychological tasks, (3) identified asymptomatic carriers of the mutation even when traditional neuropsychological measures and other measures of short-term memory did not and, (4) contrary to shape-colour binding, correlated with measures of hippocampal functions. Colour-colour binding and shape-colour binding both appear to be sensitive to AD even though they seem to rely on different brain mechanisms. Copyright © 2011 Elsevier Ltd. All rights reserved.

Colour detection thresholds in faces and colour patches.

PubMed

Tan, Kok Wei; Stephen, Ian D

2013-01-01

Human facial skin colour reflects individuals' underlying health (Stephen et al 2011 Evolution & Human Behavior 32 216-227); and enhanced facial skin CIELab b* (yellowness), a* (redness), and L* (lightness) are perceived as healthy (also Stephen et al 2009a International Journal of Primatology 30 845-857). Here, we examine Malaysian Chinese participants' detection thresholds for CIELab L* (lightness), a* (redness), and b* (yellowness) colour changes in Asian, African, and Caucasian faces and skin coloured patches. Twelve face photos and three skin coloured patches were transformed to produce four pairs of images of each individual face and colour patch with different amounts of red, yellow, or lightness, from very subtle (deltaE = 1.2) to quite large differences (deltaE = 9.6). Participants were asked to decide which of sequentially displayed, paired same-face images or colour patches were lighter, redder, or yellower. Changes in facial redness, followed by changes in yellowness, were more easily discriminated than changes in luminance. However, visual sensitivity was not greater for redness and yellowness in nonface stimuli, suggesting red facial skin colour special salience. Participants were also significantly better at recognizing colour differences in own-race (Asian) and Caucasian faces than in African faces, suggesting the existence of cross-race effect in discriminating facial colours. Humans' colour vision may have been selected for skin colour signalling (Changizi et al 2006 Biology Letters 2 217-221), enabling individuals to perceive subtle changes in skin colour, reflecting health and emotional status.

The Brazilian Air Force Uniform Distribution Process: Using Lean Thinking, Statistical Process Control and Theory of Constraints to Address Improvement Opportunities

DTIC Science & Technology

2015-03-26

universal definition” (Evans & Lindsay, 1996). Heizer and Render (2010) argue that several definitions of this term are user-based, meaning, that quality...for example, really good ice cream has high butterfat levels.” ( Heizer & Render , 2010). Garvin, in his Competing in Eight Dimensions of Quality...Montgomery, 2005). As for definition purposes, the concept adopted by this research was provided by Heizer and Render (2010), for whom Statistical Process

Reproducibility of electronic tooth colour measurements.

PubMed

Ratzmann, Anja; Klinke, Thomas; Schwahn, Christian; Treichel, Anja; Gedrange, Tomasz

2008-10-01

Clinical methods of investigation, such as tooth colour determination, should be simple, quick and reproducible. The determination of tooth colours usually relies upon manual comparison of a patient's tooth colour with a colour ring. After some days, however, measurement results frequently lack unequivocal reproducibility. This study aimed to examine an electronic method for reliable colour measurement. The colours of the teeth 14 to 24 were determined by three different examiners in 10 subjects using the colour measuring device Shade Inspector. In total, 12 measurements per tooth were taken. Two measurement time points were scheduled to be taken, namely at study onset (T(1)) and after 6 months (T(2)). At either time point, two measurement series per subject were taken by the different examiners at 2-week intervals. The inter-examiner and intra-examiner agreement of the measurement results was assessed. The concordance for lightness and colour intensity (saturation) was represented by the intra-class correlation coefficient. The categorical variable colour shade (hue) was assessed using the kappa statistic. The study results show that tooth colour can be measured independently of the examiner. Good agreement was found between the examiners.

Turn the temperature to turquoise: cues for colour change in the male chameleon grasshopper (Kosciuscola tristis) (Orthoptera: Acrididae).

PubMed

Umbers, Kate D L

2011-09-01

Rapid, reversible colour change is unusual in animals, but is a feature of male chameleon grasshoppers (Kosciuscola tristis). Understanding what triggers this colour change is paramount to developing hypotheses explaining its evolutionary significance. In a series of manipulative experiments the author quantified the effects of temperature, and time of day, as well as internal body temperature, on the colour of male K. tristis. The results suggest that male chameleon grasshoppers change colour primarily in response to temperature and that the rate of colour change varies considerably, with the change from black to turquoise occurring up to 10 times faster than the reverse. Body temperature changed quickly (within 10min) in response to changes in ambient temperature, but colour change did not match this speed and thus colour is decoupled from internal temperature. This indicates that male colour change is driven primarily by ambient temperature but that their colour does not necessarily reflect current internal temperature. I propose several functional hypotheses for male colour change in K. tristis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Prevalence of Colour Vision Anomalies Amongst Dental Professionals and its Effect on Shade Matching of Teeth

PubMed Central

Maini, Anuj Paul; Wangoo, Anuj; Singh, Sukhman; Mehar, Damanpreet Kaur

2017-01-01

Abstract Introduction The success of a restoration is dependent on accurate shade matching of teeth leading to studies evaluating the factors affecting the perception of shades. Colour vision anomalies including colour blindness have been found to exist in the population and it has been thought to be a potential factor affecting the colour perception ability. Aim The present study was done to evaluate the prevalence of colour vision anomalies and its effect on matching of shades of teeth. Materials and Methods A total of 147 dental professionals were randomly selected for the study and were first tested for visual acuity using the Snellen’s Eye Chart so as to carry on the study with only those operators who had a vision of 6/6. Then, the Ishihara’s colour charts were used to test the operators for colour vision handicap. In the last stage of the study, test for accuracy of shade selection was done using the Vitapan Classical shade guide. The shade guide tabs were covered to avoid bias. Percentage was used to calculate the prevalence of colour vision handicap and its effect on matching of shades of teeth as compared to normal vision, which was evaluated using Chi square test. Results Nineteen operators had colour vision anomalies out of hundred operators and only two operators presented with colour blindness. Colour vision anomaly was more prevalent than colour blindness and it was also found that it was more prevalent in males than females. The difference between the accuracy of shade matching between the operators with normal vision and colour vision defect and operators with normal vision and colour blindness was statistically not significant. Conclusion Colour blindness and colour vision handicap are rare conditions, with the latter being more common in the population. According to our study, it was concluded that no statistically significant difference existed amongst the operators with normal vision and colour vision anomaly or operators with normal vision and colour blindness during the matching of shades of teeth. PMID:28274040

A generalized equation for the calculation of receptor noise limited colour distances in n-chromatic visual systems

PubMed Central

Clark, R. C.; Brebner, J. S.

2017-01-01

Researchers must assess similarities and differences in colour from an animal's eye view when investigating hypotheses in ecology, evolution and behaviour. Nervous systems generate colour perceptions by comparing the responses of different spectral classes of photoreceptor through colour opponent mechanisms, and the performance of these mechanisms is limited by photoreceptor noise. Accordingly, the receptor noise limited (RNL) colour distance model of Vorobyev and Osorio (Vorobyev & Osorio 1998 Proc. R. Soc. Lond. B 265, 351–358 (doi:10.1098/rspb.1998.0302)) generates predictions about the discriminability of colours that agree with behavioural data, and consequently it has found wide application in studies of animal colour vision. Vorobyev and Osorio (1998) provide equations to calculate RNL colour distances for animals with di-, tri- and tetrachromatic vision, which is adequate for many species. However, researchers may sometimes wish to compute RNL colour distances for potentially more complex colour visual systems. Thus, we derive a simple, single formula for the computation of RNL distance between two measurements of colour, equivalent to the published di-, tri- and tetrachromatic equations of Vorobyev and Osorio (1998), and valid for colour visual systems with any number of types of noisy photoreceptors. This formula will allow the easy application of this important colour visual model across the fields of ecology, evolution and behaviour. PMID:28989773

The evolution of colour pattern complexity: selection for conspicuousness favours contrasting within-body colour combinations in lizards.

PubMed

Pérez I de Lanuza, G; Font, E

2016-05-01

Many animals display complex colour patterns that comprise several adjacent, often contrasting colour patches. Combining patches of complementary colours increases the overall conspicuousness of the complex pattern, enhancing signal detection. Therefore, selection for conspicuousness may act not only on the design of single colour patches, but also on their combination. Contrasting long- and short-wavelength colour patches are located on the ventral and lateral surfaces of many lacertid lizards. As the combination of long- and short-wavelength-based colours generates local chromatic contrast, we hypothesized that selection may favour the co-occurrence of lateral and ventral contrasting patches, resulting in complex colour patterns that maximize the overall conspicuousness of the signal. To test this hypothesis, we performed a comparative phylogenetic study using a categorical colour classification based on spectral data and descriptive information on lacertid coloration collected from the literature. Our results demonstrate that conspicuous ventral (long-wavelength-based) and lateral (short-wavelength-based) colour patches co-occur throughout the lacertid phylogeny more often than expected by chance, especially in the subfamily Lacertini. These results suggest that selection promotes the evolution of the complex pattern rather than the acquisition of a single conspicuous colour patch, possibly due to the increased conspicuousness caused by the combination of colours with contrasting spectral properties. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Colour stability of maxillofacial silicone elastomers: a review of the literature.

PubMed

Kulkarni, R S; Nagda, S J

2014-09-01

Colour degradation is a serious limitation of maxillofacial silicone elastomers and most silicone facial prostheses have to be remade within 1 year due to colour deterioration. A comprehensive review of the literature was completed using MEDLINE and PubMed Library databases. This was supplemented with a manual search of selected journals and textbooks. English language articles published in peer-reviewed journals from 1966 to January 2012 in which colour stability of silicone elastomers was evaluated using standard research protocols were included. In all, 127 articles were identified and 23 met the inclusion criteria. Current literature reveals that average colour stability of maxillofacial silicone prostheses is 6-12 months, and inherent unstable nature of silicones is responsible for the color degradation. Opacifiers, oil pigments and inorganic colourants may have a protective effect on colour stability of prostheses. Organic colourants, ultraviolet (UV) light, cleansing solutions, dust and aging can adversely affect colour stability of silicone prostheses. A direct comparison between studies has not been possible, because of the differences in experimental set-up such as materials tested, colourants used, or method of aging. There appears to be a need for a standardised test protocol for colour stability of maxillofacial materials. Colour degradation limits the useful lifespan of maxillofacial silicones. Improvements in colour stability is possible with the use of certain nano opacifiers, UV absorbers, photoprotective agents, and use of inorganic pigments and metal oxides.

Impact of colour blindness on recognition of haematuria in bladder cancer patients.

PubMed

Katmawi-Sabbagh, Samer; Haq, Ahsanul; Jain, Sunila; Subhas, Gokul; Turnham, Helen

2009-01-01

Colour blindness might lead to failure in recognizing frank haematuria. Our aim is to investigate as to whether colour-blind males who develop bladder cancer present later with less favourable histology. Two hundred male patients with bladder cancer were assessed using Ishihara plate test for colour deficiency. Degree of haematuria, method of presentation and initial histologic findings were also determined. Colour-blind patients who develop bladder cancer present with less favourable histology compared with non-colour-blind (p = 0.01). Colour blindness was associated with presentation with more advanced bladder tumours.

Colour application on mammography image segmentation

NASA Astrophysics Data System (ADS)

Embong, R.; Aziz, N. M. Nik Ab.; Karim, A. H. Abd; Ibrahim, M. R.

2017-09-01

The segmentation process is one of the most important steps in image processing and computer vision since it is vital in the initial stage of image analysis. Segmentation of medical images involves complex structures and it requires precise segmentation result which is necessary for clinical diagnosis such as the detection of tumour, oedema, and necrotic tissues. Since mammography images are grayscale, researchers are looking at the effect of colour in the segmentation process of medical images. Colour is known to play a significant role in the perception of object boundaries in non-medical colour images. Processing colour images require handling more data, hence providing a richer description of objects in the scene. Colour images contain ten percent (10%) additional edge information as compared to their grayscale counterparts. Nevertheless, edge detection in colour image is more challenging than grayscale image as colour space is considered as a vector space. In this study, we implemented red, green, yellow, and blue colour maps to grayscale mammography images with the purpose of testing the effect of colours on the segmentation of abnormality regions in the mammography images. We applied the segmentation process using the Fuzzy C-means algorithm and evaluated the percentage of average relative error of area for each colour type. The results showed that all segmentation with the colour map can be done successfully even for blurred and noisy images. Also the size of the area of the abnormality region is reduced when compare to the segmentation area without the colour map. The green colour map segmentation produced the smallest percentage of average relative error (10.009%) while yellow colour map segmentation gave the largest percentage of relative error (11.367%).

Formation of automatic letter-colour associations in non-synaesthetes through likelihood manipulation of letter-colour pairings.

PubMed

Kusnir, Flor; Thut, Gregor

2012-12-01

Grapheme-colour synaesthesia is a well-characterized phenomenon in which achromatic letters and/or digits automatically and systematically trigger specific colour sensations. Models of its underlying mechanisms diverge on a central question: whether triggered sensations reflect (1) an overdeveloped capacity in normal cross-modal processing (i.e., sharing characteristics with the general population), or rather (2) qualitatively deviant processing (i.e., unique to a few individuals). To test to what extent synaesthesia-like (automatic) letter-colour associations may be learned by non-synaesthetes into adulthood, implied by (1), we developed a learning paradigm that aimed to implicitly train such associations via a visual search task that employed statistical probability learning of specific letter-colour pairs. In contrast to previous synaesthesia-training studies (Cohen Kadosh, Henik, Catena, Walsh, & Fuentes, 2009; Meier & Rothen, 2009), here all participants were naïve as to the end-goal of the experiment (i.e., the formation of letter-colour associations), mimicking the learning conditions of acquired grapheme-colour synaesthesia (Hancock, 2006; Witthoft & Winawer, 2006). In two experiments, we found evidence for significant binding of colours to letters by non-synaesthetes. These newly-formed associations showed synaesthesia-like characteristics, because they correlated in strength with performance on individual synaesthetic Stroop-tasks (experiment 1), and because interference between the learned (associated) colour and the real colour during letter processing depended on their relative positions in colour space (opponent vs. non-opponent colours, experiment 2) suggesting automatic formation on a perceptual rather than conceptual level, analogous to synaesthesia. Although not evoking conscious colour percepts, these learned, synaesthesia-like associations in non-synaesthetes support that common mechanisms may underlie letter-colour associations in synaesthetes and non-synaesthetes. Copyright © 2012 Elsevier Ltd. All rights reserved.

A comparison of the carotenoid accumulation in Capsicum varieties that show different ripening colours: deletion of the capsanthin-capsorubin synthase gene is not a prerequisite for the formation of a yellow pepper.

PubMed

Ha, Sun-Hwa; Kim, Jung-Bong; Park, Jong-Sug; Lee, Shin-Woo; Cho, Kang-Jin

2007-01-01

Ripe pepper (Capsicum sp.) fruits can display a range of colours from white to deep red. To understand better the regulatory mechanisms of the carotenoid biosynthetic pathways that underlie these ripening colours, Capsicum varieties that show seven different fully ripe colour types were analysed. The levels and composition of the carotenoid accumulation in these samples at different stages of ripening were measured, and the resulting data were analysed in conjunction with the expression patterns of the carotenoid biosynthetic genes. It was found that red peppers accumulate increasing levels of total carotenoids during ripening, whereas non-red peppers accumulate lower levels of total carotenoids of varying composition. The expression levels of the phytoene synthase, phytoene desaturase, and capsanthin-capsorubin synthase (Ccs) genes are high in peppers with high levels of total carotenoid, whereas one or two of these genes are not expressed in peppers with lower levels of total carotenoid. Surprisingly, it was found that the Ccs gene is present in two Capsicum varieties whose ripe colour is yellow. This gene has never previously been shown to be present in yellow peppers. Sequence analyses of the Ccs gene further revealed two structural mutations in yellow peppers that may result in either a premature stop-codon or a frame-shift. Taken together with the fact that the Ccs transcript is not detectable in yellow peppers, our current results suggest that nonsense-mediated transcriptional gene silencing of Ccs and not the deletion of this gene is responsible for yellow ripening in Capsicum.

Identifying the source of colours in the Jovian atmosphere

NASA Astrophysics Data System (ADS)

Braude, Ashwin; Irwin, Patrick; Orton, Glenn S.; Fletcher, Leigh

2016-10-01

We wish to identify the source of Jupiter's colours through spectral analysis of images of Jupiter in the visible-to-near-infrared in conjunction with observations made by Juno in the mid-infrared and at super-high frequency. Three sets of observations were made of Jupiter by the MUSE integral-field spectrograph between 2014-2016 in the spectral range 0.48-0.93um, and reduced using a standard pipeline. Some large high-altitude hazes were observed in 2014 in the North Tropical Zone and the North Temperate Belt which appeared to have vanished by 2016. A single spectral image cube from 2014 was selected for analysis, and attempts at retrieving vertical cloud profiles, imaginary refractive indices and single-scattering albedos using the Nemesis radiative transfer model were made in different locations on Jupiter corresponding to the most prominent features close to the Equatorial region. Differences in lower tropospheric cloud altitude and opacity were found between the zones and the belts, and the belt cloud particles were seen to be significantly more blue-absorbing than the zone particles. Attempts were made at retrieving the real refractive index of the cloud particles in the upper tropospheric haze, where the majority of the colour-producing particles, or 'chromophores', are thought to be located, and values of refractive index greater than that of ammonia ice were observed, indicating the presence of a foreign substance. Further ground-based observations from MUSE in the visible and from TEXES in the mid-Infrared combined with localised observations from Juno later this year should shed more light on the origin of the colour-producing substance in the Jovian clouds, as well as of any seasonal changes in colour.