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

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 implementation of binding blocks in the classroom

NASA Astrophysics Data System (ADS)

Wright, A. J.; Willett, H. V.; Beanland, S. R.; Carson, M.; Davies, R. A.; Duffett, G.; Pastore, A.

2017-09-01

We discuss a series of activities for A-level students which can be carried out using the binding blocks three dimensional chart of nuclides. The planned activities cover four main sections which can be linked to the A-level curriculum; nuclear decays (as seen through the different colours on the chart), medical physics (medical isotopes highlighted on the chart), fusion on Earth (binding energy demonstrated through tower heights) and stellar fusion (which has a limit at 56Fe, illustrated by the decreasing tower heights).

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.

Minor Planet Science with the VISTA Hemisphere Survey

NASA Astrophysics Data System (ADS)

Popescu, M.; Licandro, J.; Morate, D.; de León, J.; Nedelcu, D. A.

2017-03-01

We have carried out a serendipitous search for Solar System objects imaged by the VISTA Hemisphere Survey (VHS) and have identified 230 375 valid detections for 39 947 objects. This information is available in three catalogues, entitled MOVIS. The distributions of the data in colour-colour plots show clusters identified with the different taxonomic asteroid types. Diagrams that use (Y-J) colour separate the spectral classes more effectively than any other method based on colours. In particular, the end-class members A-, D-, R-, and V-types occupy well-defined regions and can be easily identified. About 10 000 asteroids were classified taxonomically using a probabilistic approach. The distribution of basaltic asteroids across the Main Belt was characterised using the MOVIS colours: 477 V-type candidates were found, of which 244 are outside the Vesta dynamical family.

Colour spectrum and resin-type determine the concentration and composition of Polycyclic Aromatic Hydrocarbons (PAHs) in plastic pellets.

PubMed

Fisner, Mara; Majer, Alessandra; Taniguchi, Satie; Bícego, Márcia; Turra, Alexander; Gorman, Daniel

2017-09-15

This study assessed the concentration and composition of Polycyclic Aromatic Hydrocarbons (PAHs) in plastic pellets, collected from sandy beaches and considered different resin and colour tones. Results showed that polyethylene pellets, while displaying a greater range of total PAH concentrations did not differ significantly from polypropylene pellets. More importantly, both resin types demonstrated predictable increases in total PAH across a spectrum of darkening colour tones. Multivariate comparisons of 36 PAH groups, further showed considerable variability across resin type and colour, with lighter coloured pellets comprising lower molecular weight, while darker pellets contained higher weight PAHs. Overall, we show predictable variation in PAH concentrations and compositions of plastic pellets of different ages and resin types that will directly influence the potential for toxicological effects. Our findings suggest that monitoring programs should take these attributes into account when assessing the environmental risks of microplastic contamination of marine and coastal habitats. Copyright © 2017 Elsevier Ltd. All rights reserved.

Special tinted contact lens on colour-defects.

PubMed

Mutilab, H A; Sharanjeet-Kaur; Keu, L K; Choo, P F

2012-01-01

The objective of this study was to determine the visual function of colour-deficient subjects when wearing special red tint contact lenses. A total of 17 subjects with congenital colour vision deficiency (14 deutans and 3 protans), voluntarily participated in this study. The average age for the subjects was 23.00 ± 4.06 years old. Visual functions tested were visual acuity (LogMAR), contrast sensitivity (FACT Chart) and stereopsis (TNO and Howard Dolman tests). Two types of special red tint lenses were used in this study; Type I (light red) and Type II (dark red). The protans and deutans showed no significant changes in visual acuity and contrast sensitivity when wearing either type of contact lens. Stereopsis testing using the Horward-Dolman test gave no significant changes but significant differences were seen using the TNO test. Stereopsis using the TNO test was significantly poorer with the red tinted contact lenses compared to without for both protons and deutans. Testing binocularly with Ishihara plates showed that 88% (n=15) of patients passed the test with Type I and Type II contact lenses. When D15 test was done, 3 patients (17.6%) were 'normal' when using the Type I contact lenses and 2 patients (11.8%) were 'normal' when using the Type II contact lenses. However, with FM100Hue test, most patients showed deutan responses. Total error scores (TES) were found to be higher with Type I and Type II contact lenses compared to without. The Type I and II special tinted contact lens used in this study did not cause a reduction of visual acuity and contrast sensitivity for the colour defects. Stereopsis was also not reduced with the Type I and Type II contact lenses for the colour defects except when tested with the TNO test. Colour vision defects became difficult to detect using the Ishihara plates but FM100Hue test did not show any improvement with the Type I and Type II contact lenses.

Corticosterone regulates multiple colour traits in Lacerta [Zootoca] vivipara males.

PubMed

San-Jose, L M; Fitze, P S

2013-12-01

Ornamental colours usually evolve as honest signals of quality, which is supported by the fact that they frequently depend on individual condition. It has generally been suggested that some, but not all types of ornamental colours are condition dependent, indicating that different evolutionary mechanisms underlie the evolution of multiple types of ornamental colours even when these are exhibited by the same species. Stress hormones, which negatively affect condition, have been shown to affect colour traits based on different pigments and structures, suggesting that they mediate condition dependence of multiple ornament types both among and within individuals. However, studies investigating effects of stress hormones on different ornament types within individuals are lacking, and thus, evidence for this hypothesis is scant. Here, we investigated whether corticosterone mediates condition dependence of multiple ornaments by manipulating corticosterone levels and body condition (via food availability) using a two-factorial design and by assessing their effect on multiple colour traits in male common lizards. Corticosterone negatively affected ventral melanin- and carotenoid-based coloration, whereas food availability did not affect coloration, despite its significant effect on body condition. The corticosterone effect on melanin- and carotenoid-based coloration demonstrates the condition dependence of both ornaments. Moreover, corticosterone affected ventral coloration and had no effect on the nonsexually selected dorsal coloration, showing specific effects of corticosterone on ornamental ventral colours. This suggests that corticosterone simultaneously mediates condition dependence of multiple colour traits and that it therefore accounts for covariation among them, which may influence their evolution via correlational selection. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

Influence of artificial accelerated ageing on the colour stability of paints used for ocular prosthesis iris painting.

PubMed

Mundim, Fabrício M; Antunes, Pedro L; Sousa, Ana Beatriz S; Garcia, Lucas F R; Pires-de-Souza, Fernanda C P

2012-06-01

To evaluate the colour stability of paints used for ocular prosthesis iris painting submitted for accelerated artificial ageing (AAA). Forty specimens of acrylic resin for sclera (16 × 2 mm) were made and separated into eight groups (n = 10) according to the type of paint (gouache, GP; oil, OP; acrylic AP; and composite resin for characterisation, CR) and the colours used (blue/brown). After drying (72 h), a new layer of colourless acrylic resin was applied and the initial colour readout was performed (Spectrophotometer PCB 6807). New colour readouts were performed after AAA, and ΔE was calculated. Statistical analysis (two-way anova-Bonferroni, p < 0.05) demonstrated that the brown colour showed lower ΔE means in comparison with the blue colour, with statistically significant difference for AP only. Blue colour showed no statistically significant difference with regard to the type of paint used. Brown AP showed lower ΔE than the other groups, with significant difference for OP and GP. GP showed greater alteration in ΔE for the brown colour, being statistically similar only to OP. Only the AP group for brown pigment shows clinically acceptable values for colour stability after AAA. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

Maintaining mimicry diversity: optimal warning colour patterns differ among microhabitats in Amazonian clearwing butterflies.

PubMed

Willmott, Keith R; Robinson Willmott, Julia C; Elias, Marianne; Jiggins, Chris D

2017-05-31

Mimicry is one of the best-studied examples of adaptation, and recent studies have provided new insights into the role of mimicry in speciation and diversification. Classical Müllerian mimicry theory predicts convergence in warning signal among protected species, yet tropical butterflies are exuberantly diverse in warning colour patterns, even within communities. We tested the hypothesis that microhabitat partitioning in aposematic butterflies and insectivorous birds can lead to selection for different colour patterns in different microhabitats and thus help maintain mimicry diversity. We measured distribution across flight height and topography for 64 species of clearwing butterflies (Ithomiini) and their co-mimics, and 127 species of insectivorous birds, in an Amazon rainforest community. For the majority of bird species, estimated encounter rates were non-random for the two most abundant mimicry rings. Furthermore, most butterfly species in these two mimicry rings displayed the warning colour pattern predicted to be optimal for anti-predator defence in their preferred microhabitats. These conclusions were supported by a field trial using butterfly specimens, which showed significantly different predation rates on colour patterns in two microhabitats. We therefore provide the first direct evidence to support the hypothesis that different mimicry patterns can represent stable, community-level adaptations to differing biotic environments. © 2017 The Author(s).

Maintaining mimicry diversity: optimal warning colour patterns differ among microhabitats in Amazonian clearwing butterflies

PubMed Central

Robinson Willmott, Julia C.

2017-01-01

Mimicry is one of the best-studied examples of adaptation, and recent studies have provided new insights into the role of mimicry in speciation and diversification. Classical Müllerian mimicry theory predicts convergence in warning signal among protected species, yet tropical butterflies are exuberantly diverse in warning colour patterns, even within communities. We tested the hypothesis that microhabitat partitioning in aposematic butterflies and insectivorous birds can lead to selection for different colour patterns in different microhabitats and thus help maintain mimicry diversity. We measured distribution across flight height and topography for 64 species of clearwing butterflies (Ithomiini) and their co-mimics, and 127 species of insectivorous birds, in an Amazon rainforest community. For the majority of bird species, estimated encounter rates were non-random for the two most abundant mimicry rings. Furthermore, most butterfly species in these two mimicry rings displayed the warning colour pattern predicted to be optimal for anti-predator defence in their preferred microhabitats. These conclusions were supported by a field trial using butterfly specimens, which showed significantly different predation rates on colour patterns in two microhabitats. We therefore provide the first direct evidence to support the hypothesis that different mimicry patterns can represent stable, community-level adaptations to differing biotic environments. PMID:28539522

Colour vision experimental studies in teaching of optometry

NASA Astrophysics Data System (ADS)

Ozolinsh, Maris; Ikaunieks, Gatis; Fomins, Sergejs

2005-10-01

Following aspects related to human colour vision are included in experimental lessons for optometry students of University of Latvia. Characteristics of coloured stimuli (emitting and reflective), determination their coordinates in different colour spaces. Objective characteristics of transmitting of colour stimuli through the optical system of eye together with various types of appliances (lenses, prisms, Fresnel prisms). Psychophysical determination of mono- and polychromatic stimuli perception taking into account physiology of eye, retinal colour photoreceptor topography and spectral sensitivity, spatial and temporal characteristics of retinal receptive fields. Ergonomics of visual perception, influence of illumination and glare effects, testing of colour vision deficiencies.

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.

Mixing apples with oranges: Visual attention deficits in schizophrenia.

PubMed

Caprile, Claudia; Cuevas-Esteban, Jorge; Ochoa, Susana; Usall, Judith; Navarra, Jordi

2015-09-01

Patients with schizophrenia usually present cognitive deficits. We investigated possible anomalies at filtering out irrelevant visual information in this psychiatric disorder. Associations between these anomalies and positive and/or negative symptomatology were also addressed. A group of individuals with schizophrenia and a control group of healthy adults performed a Garner task. In Experiment 1, participants had to rapidly classify visual stimuli according to their colour while ignoring their shape. These two perceptual dimensions are reported to be "separable" by visual selective attention. In Experiment 2, participants classified the width of other visual stimuli while trying to ignore their height. These two visual dimensions are considered as being "integral" and cannot be attended separately. While healthy perceivers were, in Experiment 1, able to exclusively respond to colour, an irrelevant variation in shape increased colour-based reaction times (RTs) in the group of patients. In Experiment 2, RTs when classifying width increased in both groups as a consequence of perceiving a variation in the irrelevant dimension (height). However, this interfering effect was larger in the group of schizophrenic patients than in the control group. Further analyses revealed that these alterations in filtering out irrelevant visual information correlated with positive symptoms in PANSS scale. A possible limitation of the study is the relatively small sample. Our findings suggest the presence of attention deficits in filtering out irrelevant visual information in schizophrenia that could be related to positive symptomatology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of clay liquid detergent for Islamic cleansing and the stability study.

PubMed

Angkatavanich, J; Dahlan, W; Nimmannit, U; Sriprasert, V; Sulongkood, N

2009-04-01

Clay liquid detergents (CLDs) were developed for cleansing religiously-prohibited dirt ('najis') according to Islamic law. Four types of clay were selected: marl, kaolin, bentonite and veegum. After product development trials, five CLD formulations with varying combinations of clays were qualified for stability testing. Three exaggerated temperature conditions were considered: 4 degrees C for 24 h, 50 degrees C for 7 days, and 40 degrees C for 1 month. The CLDs were also evaluated at 30, 60 and 90 days after production, while being stored at room temperature (RT30, RT60 and RT90). Physical and chemical characteristics including pH, colour, viscosity, surface tension, foam tests and sensory liking scores were evaluated. Our results showed that the kaolin-based formula, F2, had an optimal pH (closest to skin pH) of 5.08. The other formulas ranged from pH 6 to 8. Colour shades of the CLDs ranged from white, to creamy white, to mildly greenish-white. The foaming properties of the CLDs, the means +/- SD of foam heights at 0 and 5 min, using the Ross-Miles test, were 19.13 +/- 0.25 to 20.88 +/- 0.45 cm at RT90 and were comparable with those of commercial detergents. Foam stability of all CLDs was high, as shown from the foam heights between 0 and 5 min being not significantly different (P > 0.05). The surface tensions, means +/- SD, of CLD solutions were between 27.94 +/- 0.08 and 28.72 +/- 0.04 mN m(-1), which were slightly better than the surface tension of 29.08 +/- 0.04 mN m(-1) for sodium lauryl sulphate. There was a weak negative relationship between surface activity and foam height, based on the pooled data of the CLDs (R(2) = 0.209, P < 0.01). The viscosity of four CLDs ranged from 16 317 to 49 036 mPa s. In conclusion, CLDs can be formulated with good stability. F2 (kaolin-based, with a white, creamy texture) was the best CLD formula. It had the highest surface activity, moderate lathering and pleasant physical appearance.

Do type 2 diabetes patients without diabetic retinopathy or subjects with impaired fasting glucose have impaired colour vision? The Okubo Color Study Report.

PubMed

Shoji, T; Sakurai, Y; Sato, H; Chihara, E; Takeuchi, M

2011-07-01

To investigate associations between fasting plasma glucose level and the prevalence of acquired colour vision impairment in type 2 diabetes patients without diabetic retinopathy. Participants in this cross-sectional study of male officials aged 20-60 yr in the Japanese Self Defence Force, underwent colour vision testing, ophthalmic examination, a standardized interview and examination of venous blood samples. Ishihara plates, a Lanthony 15-hue desaturated panel and Standard Pseudoisochromatic Plates Part 2 were used to examine colour vision. The Farnsworth-Munsell 100-hue test was performed to define acquired colour vision impairment. Cardiovascular disease risk factors were determined from serum blood samples, physical records and an interview. We performed logistic regression analysis adjusted for age, diagnosed hypertension, dyslipidaemia, cataract, glaucoma, being overweight, smoking status and alcohol intake. Crude and adjusted odds ratios were calculated for three glucose levels, which included normal fasting glucose, impaired fasting glucose and diabetes. Out of a total of 1042 men enrolled, 872 were eligible for the study, and 31 were diagnosed with acquired colour vision impairment. As compared with the subjects with normal fasting glucose (< 5.6 mmol/l), the crude odds ratio for acquired colour vision impairment was 0.93 (95% CI 0.32-2.74) for the subjects with impaired fasting glucose (5.6-6.9 mmol/l) and 8.07 (95% CI 2.48-26.22) for the patients with type 2 diabetes. The multiple-adjusted odds ratios were 0.77 (95% CI 0.25-2.34) for the subjects with impaired fasting glucose and 5.89 (95% CI 1.55-22.40) for the patients with type 2 diabetes. Our findings suggest that there is a dramatically increased prevalence of acquired colour vision impairment in type 2 diabetes patients without diabetic retinopathy which might be attributable to another pathogenesis associated with diabetic retinopathy. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.

Colour learning when foraging for nectar and pollen: bees learn two colours at once.

PubMed

Muth, Felicity; Papaj, Daniel R; Leonard, Anne S

2015-09-01

Bees are model organisms for the study of learning and memory, yet nearly all such research to date has used a single reward, nectar. Many bees collect both nectar (carbohydrates) and pollen (protein) on a single foraging bout, sometimes from different plant species. We tested whether individual bumblebees could learn colour associations with nectar and pollen rewards simultaneously in a foraging scenario where one floral type offered only nectar and the other only pollen. We found that bees readily learned multiple reward-colour associations, and when presented with novel floral targets generalized to colours similar to those trained for each reward type. These results expand the ecological significance of work on bee learning and raise new questions regarding the cognitive ecology of pollination. © 2015 The Author(s).

Inheritance of coat colour in the Anatolian shepherd dog.

PubMed

Robinson, R

1989-01-01

The predominant colour of the Anatolian Shepherd dog varies from a dark fawn to light red, with a variable black muzzle and face (mask). Evidence is presented that the colour is due to the dominant yellow allele (Ay) of the agouti locus. Two other frequent colours are white spotting, due to the piebald allele (sp), and the chinchilla allele (ch). Two rarer colours are the agouti wolf-grey wild type (A+) and a light fawn with a blue facial mask, due to the dilution allele (d).

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.

Egg production and quality under three housing systems in the tropics.

PubMed

Varguez-Montero, Grissly; Sarmiento-Franco, Luis; Santos-Ricalde, Ronald; Segura-Correa, Jose

2012-02-01

The aim of this study was to evaluate egg production and quality of Rhode Island Red (RIR) laying hens in an outdoor system in the subhumid tropic. Eighty RIR laying hens were measured in two periods and housed randomly under three treatments: outdoor (O), indoor (I) and in conventional cages (C). Egg weight (55.88, 53.76 and 57.16 g, for O, I and C, respectively), food intake/hen/day (138.94, 129.74 and 162.90 g, for O, I and C, respectively) and food efficiency (3.13, 3.22 and 3.96 for O, I and C, respectively) were significantly (P < 0.05) influenced by housing system; however, both egg production and final body weight were not different (P > 0.05). Yolk colour (10.76, 9.94 and 10.08 colour scale, for O, I and C, respectively), albumen weight (92.63, 92.28 and 90.08 g, for O, I and C, respectively) and yolk weight (15.19, 14.61, 15.48 g for O, I and C, respectively) were significantly (P < 0.05) influenced by housing system, but albumen height, Haugh units and egg shell weight remained similar (P > 0.05). Under the conditions of this study, outdoor egg production seems to be a sustainable system comparable to the commercial type based on wired cages.

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.

Colour cues proved to be more informative for dogs than brightness.

PubMed

Kasparson, Anna A; Badridze, Jason; Maximov, Vadim V

2013-09-07

The results of early studies on colour vision in dogs led to the conclusion that chromatic cues are unimportant for dogs during their normal activities. Nevertheless, the canine retina possesses two cone types which provide at least the potential for colour vision. Recently, experiments controlling for the brightness information in visual stimuli demonstrated that dogs have the ability to perform chromatic discrimination. Here, we show that for eight previously untrained dogs colour proved to be more informative than brightness when choosing between visual stimuli differing both in brightness and chromaticity. Although brightness could have been used by the dogs in our experiments (unlike previous studies), it was not. Our results demonstrate that under natural photopic lighting conditions colour information may be predominant even for animals that possess only two spectral types of cone photoreceptors.

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

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.

Observed Type II supernova colours from the Carnegie Supernova Project-I

NASA Astrophysics Data System (ADS)

de Jaeger, T.; Anderson, J. P.; Galbany, L.; González-Gaitán, S.; Hamuy, M.; Phillips, M. M.; Stritzinger, M. D.; Contreras, C.; Folatelli, G.; Gutiérrez, C. P.; Hsiao, E. Y.; Morrell, N.; Suntzeff, N. B.; Dessart, L.; Filippenko, A. V.

2018-06-01

We present a study of observed Type II supernova (SN II) colours using optical/near-infrared photometric data from the Carnegie Supernovae Project-I. We analyse four colours (B - V, u - g, g - r, and g - Y) and find that SN II colour curves can be described by two linear regimes during the photospheric phase. The first (s1, colour) is steeper and has a median duration of ˜40 d. The second, shallower slope (s2, colour) lasts until the end of the `plateau' (˜80 d). The two slopes correlate in the sense that steeper initial colour curves also imply steeper colour curves at later phases. As suggested by recent studies, SNe II form a continuous population of objects from the colour point of view as well. We investigate correlations between the observed colours and a range of photometric and spectroscopic parameters including the absolute magnitude, the V-band light-curve slopes, and metal-line strengths. We find that less luminous SNe II appear redder, a trend that we argue is not driven by uncorrected host-galaxy reddening. While there is significant dispersion, we find evidence that redder SNe II (mainly at early epochs) display stronger metal-line equivalent widths. Host-galaxy reddening does not appear to be a dominant parameter, neither driving observed trends nor dominating the dispersion in observed colours. Intrinsic SN II colours are most probably dominated by photospheric temperature differences, with progenitor metallicity possibly playing a minor role. Such temperature differences could be related to differences in progenitor radius, together with the presence or absence of circumstellar material close to the progenitor stars.

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.

Skin of colour: Characteristics and disease.

PubMed

Zaidi, Zohra

2017-02-01

Skin colour varies from pale white to very dark. Fitzpatrick's skin phototypes are based on the person's skin colour and its response to sun exposure in terms of burning and tanning of the skin. Fitzpatrick's type 1V-V1 is known as the skin of colour and type 1-111 is the fair or white skin. The colour of the skin and texture of the hair are the most apparent phenotype to differentiate the different races; this correlates closely with the geography and ultraviolet radiation of the sun. There are notable differences in skin disease incidence, presentation, and treatment based on skin type. Differences in skin anatomy and physiology between the fair skin and the skin of colour may explain disparities in skin disorders and provide insight into appropriate differences in the management of cutaneous disease. Differences in culture and habits may produce skin lesions unknown to the local physicians. Temperature, humidity and rainfall are closely interwoven with the fauna and flora of the area. Hot and humid climate favours bacterial and fungal infections. Today in this multicultural society due to globalization, a physician has to see patients from all over the globe. There is a need for the physicians to know the diseases of people from different racial and ethnic backgrounds for early diagnosis and treatment.

Coevolution of coloration and colour vision?

PubMed

Lind, Olle; Henze, Miriam J; Kelber, Almut; Osorio, Daniel

2017-07-05

The evolutionary relationship between signals and animal senses has broad significance, with potential consequences for speciation, and for the efficacy and honesty of biological communication. Here we outline current understanding of the diversity of colour vision in two contrasting groups: the phylogenetically conservative birds, and the more variable butterflies. Evidence for coevolution of colour signals and vision exists in both groups, but is limited to observations of phenotypic differences between visual systems, which might be correlated with coloration. Here, to illustrate how one might interpret the evolutionary significance of such differences, we used colour vision modelling based on an avian eye to evaluate the effects of variation in three key characters: photoreceptor spectral sensitivity, oil droplet pigmentation and the proportions of different photoreceptor types. The models predict that physiologically realistic changes in any one character will have little effect, but complementary shifts in all three can substantially affect discriminability of three types of natural spectra. These observations about the adaptive landscape of colour vision may help to explain the general conservatism of photoreceptor spectral sensitivities in birds. This approach can be extended to other types of eye and spectra to inform future work on coevolution of coloration and colour vision.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

Bleed-through correction for rendering and correlation analysis in multi-colour localization microscopy

PubMed Central

Kim, Dahan; Curthoys, Nikki M.; Parent, Matthew T.; Hess, Samuel T.

2015-01-01

Multi-colour localization microscopy has enabled sub-diffraction studies of colocalization between multiple biological species and quantification of their correlation at length scales previously inaccessible with conventional fluorescence microscopy. However, bleed-through, or misidentification of probe species, creates false colocalization and artificially increases certain types of correlation between two imaged species, affecting the reliability of information provided by colocalization and quantified correlation. Despite the potential risk of these artefacts of bleed-through, neither the effect of bleed-through on correlation nor methods of its correction in correlation analyses has been systematically studied at typical rates of bleed-through reported to affect multi-colour imaging. Here, we present a reliable method of bleed-through correction applicable to image rendering and correlation analysis of multi-colour localization microscopy. Application of our bleed-through correction shows our method accurately corrects the artificial increase in both types of correlations studied (Pearson coefficient and pair correlation), at all rates of bleed-through tested, in all types of correlations examined. In particular, anti-correlation could not be quantified without our bleed-through correction, even at rates of bleed-through as low as 2%. Demonstrated with dichroic-based multi-colour FPALM here, our presented method of bleed-through correction can be applied to all types of localization microscopy (PALM, STORM, dSTORM, GSDIM, etc.), including both simultaneous and sequential multi-colour modalities, provided the rate of bleed-through can be reliably determined. PMID:26185614

Bleed-through correction for rendering and correlation analysis in multi-colour localization microscopy.

PubMed

Kim, Dahan; Curthoys, Nikki M; Parent, Matthew T; Hess, Samuel T

2013-09-01

Multi-colour localization microscopy has enabled sub-diffraction studies of colocalization between multiple biological species and quantification of their correlation at length scales previously inaccessible with conventional fluorescence microscopy. However, bleed-through, or misidentification of probe species, creates false colocalization and artificially increases certain types of correlation between two imaged species, affecting the reliability of information provided by colocalization and quantified correlation. Despite the potential risk of these artefacts of bleed-through, neither the effect of bleed-through on correlation nor methods of its correction in correlation analyses has been systematically studied at typical rates of bleed-through reported to affect multi-colour imaging. Here, we present a reliable method of bleed-through correction applicable to image rendering and correlation analysis of multi-colour localization microscopy. Application of our bleed-through correction shows our method accurately corrects the artificial increase in both types of correlations studied (Pearson coefficient and pair correlation), at all rates of bleed-through tested, in all types of correlations examined. In particular, anti-correlation could not be quantified without our bleed-through correction, even at rates of bleed-through as low as 2%. Demonstrated with dichroic-based multi-colour FPALM here, our presented method of bleed-through correction can be applied to all types of localization microscopy (PALM, STORM, dSTORM, GSDIM, etc.), including both simultaneous and sequential multi-colour modalities, provided the rate of bleed-through can be reliably determined.

Reduction of non-enzymatic browning of orange juice and semi-concentrates by removal of reaction substrate.

PubMed

Sharma, Satish K; Juyal, Shashibala; Rao, V K; Yadav, V K; Dixit, A K

2014-07-01

A study was conducted to standardize the technology for the removal of amino acids (one of the browning reaction substrates) from sweet orange cv. Malta Common juice to reduce colour and quality deterioration in single strength juice and during subsequent concentration. Juice of sweet orange (Citrus sinensis) cv. Malta Common fruits was extracted by screw type juice extractor, preserved in 500 ppm SO2 and clarified by using "Pectinase CCM" enzyme (0.2% for 2 h at 50 ± 2 °C). For removal of amino acids juice was passed under gravity through a glass column packed with an acidic cation exchange resin (CER), Dowex-50 W and quantity to be treated in one lot was standardized. The CER treated and untreated juices were concentrated to 15 and 30°Brix in a rotary vacuum evaporator. Results indicate that 121 ml of orange juice when passed through a glass column (5 cm internal diameter) packed with cation exchange resin (Dowex-50 W) upto a height of 8 cm, could remove about 98.4% of the amino acids with minimum losses in other juice constituents. With cation exchange resin treatment, the non-enzymatic browning and colour deterioration of orange juice semi-concentrates was reduced to about 3 folds in comparison to untreated counterparts. The retention of vitamin C and sugars was also better in semi-concentrates prepared from cation exchange resin treated juice. Thus, cation exchange resin treatment of orange juice prior to concentration and storage is highly beneficial in reduction of non-enzymatic browning, colour deterioration and retention of nutritional, sensory quality of product during preparation and storage.

Colour stabilities of three types of orthodontic clear aligners exposed to staining agents

PubMed Central

Liu, Chen-Lu; Sun, Wen-Tian; Liao, Wen; Lu, Wen-Xin; Li, Qi-Wen; Jeong, Yunho; Liu, Jun; Zhao, Zhi-He

2016-01-01

The aim of this study was to evaluate and compare the colour stabilities of three types of orthodontic clear aligners exposed to staining agents in vitro. Sixty clear orthodontic aligners produced by three manufacturers (Invisalign, Angelalign, and Smartee) were immersed in three staining solutions (coffee, black tea, and red wine) and one control solution (distilled water). After 12-h and 7-day immersions, the aligners were washed in an ultrasonic cleaner and measured with a colourimeter. The colour changes (ΔE*) were calculated on the basis of the Commission Internationale de I'Eclairage L*a*b* colour system (CIE L*a*b*), and the results were then converted into National Bureau of Standards (NBS) units. Fourier transformation infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) were conducted to observe the molecular and morphologic alterations to the aligner surfaces, respectively. The three types of aligners exhibited slight colour changes after 12 h of staining, with the exception of the Invisalign aligners stained with coffee. The Invisalign aligners exhibited significantly higher ΔE* values (ranging from 0.30 to 27.81) than those of the Angelalign and Smartee aligners (ΔE* values ranging from 0.33 to 1.89 and 0.32 to 1.61, respectively, P<0.05). FT-IR analysis confirmed that the polymer-based structure of aligners did not exhibit significant chemical differences before and after the immersions. The SEM results revealed different surface alterations to the three types of aligner materials after the 7-day staining. The three types of aesthetic orthodontic appliances exhibited colour stability after the 12-h immersion, with the exception of the Invisalign aligners stained by coffee. The Invisalign aligners were more prone than the Angelalign and Smartee aligners to pigmentation. Aligner materials may be improved by considering aesthetic colour stability properties. PMID:27660048

Colour stabilities of three types of orthodontic clear aligners exposed to staining agents.

PubMed

Liu, Chen-Lu; Sun, Wen-Tian; Liao, Wen; Lu, Wen-Xin; Li, Qi-Wen; Jeong, Yunho; Liu, Jun; Zhao, Zhi-He

2016-12-16

The aim of this study was to evaluate and compare the colour stabilities of three types of orthodontic clear aligners exposed to staining agents in vitro. Sixty clear orthodontic aligners produced by three manufacturers (Invisalign, Angelalign, and Smartee) were immersed in three staining solutions (coffee, black tea, and red wine) and one control solution (distilled water). After 12-h and 7-day immersions, the aligners were washed in an ultrasonic cleaner and measured with a colourimeter. The colour changes (ΔE*) were calculated on the basis of the Commission Internationale de I'Eclairage L*a*b* colour system (CIE L*a*b*), and the results were then converted into National Bureau of Standards (NBS) units. Fourier transformation infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) were conducted to observe the molecular and morphologic alterations to the aligner surfaces, respectively. The three types of aligners exhibited slight colour changes after 12 h of staining, with the exception of the Invisalign aligners stained with coffee. The Invisalign aligners exhibited significantly higher ΔE* values (ranging from 0.30 to 27.81) than those of the Angelalign and Smartee aligners (ΔE* values ranging from 0.33 to 1.89 and 0.32 to 1.61, respectively, P<0.05). FT-IR analysis confirmed that the polymer-based structure of aligners did not exhibit significant chemical differences before and after the immersions. The SEM results revealed different surface alterations to the three types of aligner materials after the 7-day staining. The three types of aesthetic orthodontic appliances exhibited colour stability after the 12-h immersion, with the exception of the Invisalign aligners stained by coffee. The Invisalign aligners were more prone than the Angelalign and Smartee aligners to pigmentation. Aligner materials may be improved by considering aesthetic colour stability properties.

Analysis of colour stability of selected provisional prosthetic materials: an in vitro study.

PubMed

Koczorowski, Ryszard; Linkowska-Swidzińska, Kamila; Gedrange, Tomasz; Swidziński, Teodor

2009-08-01

Prosthetic restorative materials (that are) used for temporary fixed dentures tend to exhibit variable discolouration over several weeks of use. The aim of this study was to perform a spectrophotometric analysis of the influence of selected discolouring factors on the colour stability of provisional prosthetic materials in vitro. In the study, the following prosthetic materials for short-term use in the oral cavity were evaluated: Luxatemp, Structur 2S.C., Protemp II, Zhermacryl STC and Dentalon Plus. Samples of these materials were immersed in coffee, tea and dark fruit juice for 60 h at different pH values. Colour was evaluated by determining the monochromatic coefficients of light reflected by the samples, using a spectrophotometric method. Results received in artificial light (illuminant A) were compared with those obtained in daylight (illuminant D65). Changes in colour and its parameters according to the CIE L*a*b* system were analysed. The analysis (of the colour and colour parameters) of the tested materials in two types of light showed that Structur displayed the greatest tendency to discolouration and that the least tendency to discolouration was exhibited by Dentalon Plus. The fact that colour parameters obtained in two types of light were not identical suggests that changes in the colour of the same material may be perceived differently, depending on the illuminant. Provisional prosthetic materials show variable colour stability under different conditions in the oral cavity. The colour of prosthetic materials may be perceived differently, depending on the illuminant and the effect of the environment in which they are used.

Molecular logic behind the three-way stochastic choices that expand butterfly colour vision.

PubMed

Perry, Michael; Kinoshita, Michiyo; Saldi, Giuseppe; Huo, Lucy; Arikawa, Kentaro; Desplan, Claude

2016-07-14

Butterflies rely extensively on colour vision to adapt to the natural world. Most species express a broad range of colour-sensitive Rhodopsin proteins in three types of ommatidia (unit eyes), which are distributed stochastically across the retina. The retinas of Drosophila melanogaster use just two main types, in which fate is controlled by the binary stochastic decision to express the transcription factor Spineless in R7 photoreceptors. We investigated how butterflies instead generate three stochastically distributed ommatidial types, resulting in a more diverse retinal mosaic that provides the basis for additional colour comparisons and an expanded range of colour vision. We show that the Japanese yellow swallowtail (Papilio xuthus, Papilionidae) and the painted lady (Vanessa cardui, Nymphalidae) butterflies have a second R7-like photoreceptor in each ommatidium. Independent stochastic expression of Spineless in each R7-like cell results in expression of a blue-sensitive (Spineless(ON)) or an ultraviolet (UV)-sensitive (Spineless(OFF)) Rhodopsin. In P. xuthus these choices of blue/blue, blue/UV or UV/UV sensitivity in the two R7 cells are coordinated with expression of additional Rhodopsin proteins in the remaining photoreceptors, and together define the three types of ommatidia. Knocking out spineless using CRISPR/Cas9 (refs 5, 6) leads to the loss of the blue-sensitive fate in R7-like cells and transforms retinas into homogeneous fields of UV/UV-type ommatidia, with corresponding changes in other coordinated features of ommatidial type. Hence, the three possible outcomes of Spineless expression define the three ommatidial types in butterflies. This developmental strategy allowed the deployment of an additional red-sensitive Rhodopsin in P. xuthus, allowing for the evolution of expanded colour vision with a greater variety of receptors. This surprisingly simple mechanism that makes use of two binary stochastic decisions coupled with local coordination may prove to be a general means of generating an increased diversity of developmental outcomes.

An investigation of spatial representation of pitch in individuals with congenital amusia.

PubMed

Lu, Xuejing; Sun, Yanan; Thompson, William Forde

2017-09-01

Spatial representation of pitch plays a central role in auditory processing. However, it is unknown whether impaired auditory processing is associated with impaired pitch-space mapping. Experiment 1 examined spatial representation of pitch in individuals with congenital amusia using a stimulus-response compatibility (SRC) task. For amusic and non-amusic participants, pitch classification was faster and more accurate when correct responses involved a physical action that was spatially congruent with the pitch height of the stimulus than when it was incongruent. However, this spatial representation of pitch was not as stable in amusic individuals, revealed by slower response times when compared with control individuals. One explanation is that the SRC effect in amusics reflects a linguistic association, requiring additional time to link pitch height and spatial location. To test this possibility, Experiment 2 employed a colour-classification task. Participants judged colour while ignoring a concurrent pitch by pressing one of two response keys positioned vertically to be congruent or incongruent with the pitch. The association between pitch and space was found in both groups, with comparable response times in the two groups, suggesting that amusic individuals are only slower to respond to tasks involving explicit judgments of pitch.

The influence of the microscope lamp filament colour temperature on the process of digital images of histological slides acquisition standardization.

PubMed

Korzynska, Anna; Roszkowiak, Lukasz; Pijanowska, Dorota; Kozlowski, Wojciech; Markiewicz, Tomasz

2014-01-01

The aim of this study is to compare the digital images of the tissue biopsy captured with optical microscope using bright field technique under various light conditions. The range of colour's variation in immunohistochemically stained with 3,3'-Diaminobenzidine and Haematoxylin tissue samples is immense and coming from various sources. One of them is inadequate setting of camera's white balance to microscope's light colour temperature. Although this type of error can be easily handled during the stage of image acquisition, it can be eliminated with use of colour adjustment algorithms. The examination of the dependence of colour variation from microscope's light temperature and settings of the camera is done as an introductory research to the process of automatic colour standardization. Six fields of view with empty space among the tissue samples have been selected for analysis. Each field of view has been acquired 225 times with various microscope light temperature and camera white balance settings. The fourteen randomly chosen images have been corrected and compared, with the reference image, by the following methods: Mean Square Error, Structural SIMilarity and visual assessment of viewer. For two types of backgrounds and two types of objects, the statistical image descriptors: range, median, mean and its standard deviation of chromaticity on a and b channels from CIELab colour space, and luminance L, and local colour variability for objects' specific area have been calculated. The results have been averaged for 6 images acquired in the same light conditions and camera settings for each sample. The analysis of the results leads to the following conclusions: (1) the images collected with white balance setting adjusted to light colour temperature clusters in certain area of chromatic space, (2) the process of white balance correction for images collected with white balance camera settings not matched to the light temperature moves image descriptors into proper chromatic space but simultaneously the value of luminance changes. So the process of the image unification in a sense of colour fidelity can be solved in separate introductory stage before the automatic image analysis.

The Colour of Words.

ERIC Educational Resources Information Center

Farrar, Bernice Lever

Students from the ages of 13 or 14 onward need to know the "colours of words" which can let them live fully in the rainbow of life, thus eliminating student fears associated with written language and of being pawns of those who have the power of words, especially written words. Colour coding the eight basic types of work that words can…

Lightness and Hue Perception: The Bezold-Brucke Effect and Colour Basic Categories

ERIC Educational Resources Information Center

Lillo, Julio; Aguado, Luis; Moreira, Humberto; Davies, Ian

2004-01-01

Using surface colours as stimuli, the present research was aimed at the two following goals: (1) To determine the chromatic angles related to categorical effects type B-B (Bezold-Brucke). (2) To determine the colourimetric characteristics compatible with each Spanish colour basic category. To get these goals the full set of tiles included in the…

Clinical colour vision tests.

PubMed

Dain, Stephen J

2004-07-01

The structure and function of the available and significant clinical colour vision tests are reviewed in the light of the needs in the clinical examination of congenital and acquired colour vision deficiencies. The tests are grouped and described as pseudo-isochromatic plates, arrangement tests, matching tests and vocational tests. The colorimetric constructions of the test types are described and the efficiency of their performance and usefulness discussed. Recommendations are made for basic and extended test batteries, when examining of congenital and acquired colour vision deficiencies in the consulting room.

Iris colour in relation to myopia among Chinese school-aged children.

PubMed

Pan, Chen-Wei; Qiu, Qin-Xiao; Qian, Deng-Juan; Hu, Dan-Ning; Li, Jun; Saw, Seang-Mei; Zhong, Hua

2018-01-01

Understanding the association of iris colour and myopia may provide further insights into the role of the wavelength of lights in the pathophysiology of myopia. We aim to assess the association of iris colour and myopia in a school-based sample of Chinese students. Two thousand three hundred and forty-six Year 7 students from 10 middle schools (93.5% response rate) aged 13-14 years in Mojiang, a small county located in Southwestern China, participated in the study. We obtained standardised slit lamp photographs and developed a grading system assessing iris colour (higher grade denoting a darker iris). Refractive error was measured after cycloplegia using an autorefractor by optometrists or trained technicians. An IOLMaster (www.zeiss.com) was used to measure ocular biometric parameters including axial length (AL). Of all the study participants, 693 (29.5%) were affected by myopia with the prevalence estimates being higher in girls (36.8%; 95% confidence interval [CI]: 34.0, 39.6) than in boys (22.8%; 95% CI: 20.4, 25.1) (p < 0.001). After adjusting for gender, height, parental history of myopia, time spent on computer, time spent watching TV, time spent outdoors, and time spent reading and writing, participants with a darker iris colour tended to have a higher prevalence of myopia, a more myopic refraction and a longer AL. Dose-response relationships were observed in all regression models (p for trend <0.05). Darker iris colour was associated with more myopic refractive errors and longer ALs among Chinese school-aged children and this association was independent of other known myopia-related risk factors. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

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.

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.

The dual rod system of amphibians supports colour discrimination at the absolute visual threshold

PubMed Central

Yovanovich, Carola A. M.; Koskela, Sanna M.; Nevala, Noora; Kondrashev, Sergei L.

2017-01-01

The presence of two spectrally different kinds of rod photoreceptors in amphibians has been hypothesized to enable purely rod-based colour vision at very low light levels. The hypothesis has never been properly tested, so we performed three behavioural experiments at different light intensities with toads (Bufo) and frogs (Rana) to determine the thresholds for colour discrimination. The thresholds of toads were different in mate choice and prey-catching tasks, suggesting that the differential sensitivities of different spectral cone types as well as task-specific factors set limits for the use of colour in these behavioural contexts. In neither task was there any indication of rod-based colour discrimination. By contrast, frogs performing phototactic jumping were able to distinguish blue from green light down to the absolute visual threshold, where vision relies only on rod signals. The remarkable sensitivity of this mechanism comparing signals from the two spectrally different rod types approaches theoretical limits set by photon fluctuations and intrinsic noise. Together, the results indicate that different pathways are involved in processing colour cues depending on the ecological relevance of this information for each task. This article is part of the themed issue ‘Vision in dim light’. PMID:28193811

Young, metal-enriched cores in early-type dwarf galaxies in the Virgo cluster based on colour gradients

NASA Astrophysics Data System (ADS)

Urich, Linda; Lisker, Thorsten; Janz, Joachim; van de Ven, Glenn; Leaman, Ryan; Boselli, Alessandro; Paudel, Sanjaya; Sybilska, Agnieszka; Peletier, Reynier F.; den Brok, Mark; Hensler, Gerhard; Toloba, Elisa; Falcón-Barroso, Jesús; Niemi, Sami-Matias

2017-10-01

Early-type dwarf galaxies are not simply featureless, old objects, but were found to be much more diverse, hosting substructures and a variety of stellar population properties. To explore the stellar content of faint early-type galaxies, and to investigate in particular those with recent central star formation, we study colours and colour gradients within one effective radius in optical (g - r) and near-infrared (I - H) bands for 120 Virgo cluster early-type galaxies with - 19 mag

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

[An experimental evaluation of the efficacy of 4 types of detergents for 3 types of dyes to which workers in color-printing plants are exposed].

PubMed

Terzaghi, G F; Settimi, L; Peverelli, C; Sevosi, L; Duca, P G

1996-01-01

The efficacy of 4 commercial cleansing products was tested with 3 colouring agents widely used in the dyeing industry in a randomised double blind trail involving 8 workers each time. A between-detergents statistically significant difference was observed; the interaction (detergents x colouring agents) was significant. The efficacy of type A detergent was higher for type I-III dyers, while the efficacy of type C detergent, which widely used was lowest.

Marked colour divergence in the gliding membranes of a tropical lizard mirrors population differences in the colour of falling leaves

PubMed Central

Klomp, D. A.; Stuart-Fox, D.; Das, I.; Ord, T. J.

2014-01-01

Populations of the Bornean gliding lizard, Draco cornutus, differ markedly in the colour of their gliding membranes. They also differ in local vegetation type (mangrove forest versus lowland rainforest) and consequently, the colour of falling leaves (red and brown/black in mangrove versus green, brown and black in rainforest). We show that the gliding membranes of these lizards closely match the colours of freshly fallen leaves in the local habitat as they appear to the visual system of birds (their probable predators). Furthermore, gliding membranes more closely resembled colours of local fallen leaves than standing foliage or fallen leaves in the other population's habitat. This suggests that the two populations have diverged in gliding membrane coloration to match the colours of their local falling leaves, and that mimicking falling leaves is an adaptation that functions to reduce predation by birds. PMID:25540157

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.

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 effects of colour and valence on news evaluation.

PubMed

Kaspar, Kai; Grümmer, Melanie; Kießler, Antje; Neuß, Celina; Schröter, Franziska

2017-12-01

Research across different fields of psychology has reported effects of colour cues on a variety of cognitive processes. Especially, the colour red has been shown to have striking influences. In the context of media reception, however, colour effects have been widely neglected so far. This study made a first step in this direction by investigating the effects of the colour red (compared with blue and grey) on the way news articles are evaluated. Two types of news were framed by a coloured border while the valence of the news content additionally varied. Based on 369 participants who read and evaluated the news articles online, we observed effects for colour cues and news valence in the absence of an interaction effect, indicating that the colour red induced approach motivation. However, only the contrast between red and grey reached statistical significance, indicating that chromatic and achromatic colours may differ in their perceived visual saliency. Overall, these results provide an important complement to previous studies and have practical implications for media researchers and producers. © 2015 International Union of Psychological Science.

Parallel inputs to memory in bee colour vision.

PubMed

Horridge, Adrian

2016-03-01

In the 19(th) century, it was found that attraction of bees to light was controlled by light intensity irrespective of colour, and a few critical entomologists inferred that vision of bees foraging on flowers was unlike human colour vision. Therefore, quite justly, Professor Carl von Hess concluded in his book on the Comparative Physiology of Vision (1912) that bees do not distinguish colours in the way that humans enjoy. Immediately, Karl von Frisch, an assistant in the Zoology Department of the same University of Münich, set to work to show that indeed bees have colour vision like humans, thereby initiating a new research tradition, and setting off a decade of controversy that ended only at the death of Hess in 1923. Until 1939, several researchers continued the tradition of trying to untangle the mechanism of bee vision by repeatedly testing trained bees, but made little progress, partly because von Frisch and his legacy dominated the scene. The theory of trichromatic colour vision further developed after three types of receptors sensitive to green, blue, and ultraviolet (UV), were demonstrated in 1964 in the bee. Then, until the end of the century, all data was interpreted in terms of trichromatic colour space. Anomalies were nothing new, but eventually after 1996 they led to the discovery that bees have a previously unknown type of colour vision based on a monochromatic measure and distribution of blue and measures of modulation in green and blue receptor pathways. Meanwhile, in the 20(th) century, search for a suitable rationalization, and explorations of sterile culs-de-sac had filled the literature of bee colour vision, but were based on the wrong theory.

Removal of colour, turbidity, oil and grease for slaughterhouse wastewater using electrocoagulation method

NASA Astrophysics Data System (ADS)

Yusoff, Mohd Suffian; Azwan, Azlyza Mohd; Zamri, Mohd Faiz Muaz Ahmad; Aziz, Hamidi Abdul

2017-10-01

In this study electrocoagulation method is used to treat slaughterhouse wastewaters. The aim of this study is to determine the efficiency of electrocoagulation method for the removal of colour, turbidity, oil and grease of slaughterhouse wastewaters. The factors of electrode types, and voltage applied during treatment are the study parameters. The types of electrode used are Aluminium (Al) grade 6082 and Iron (Fe) grade 1050. Meanwhile, the ranges of voltage applied are 2, 4, 6, 8 volts at a time interval of 10, 20 and 30 minutes respectively. The effect of these factors on the removal of fat oil and grease (FOG), colour and turbidity are analyzed. The results show maximum removal of FOG, colour and turbidity are recorded using Fe electrode at 8 V of applied voltage with 30 minutes of treatment time. The increase in treatment time of the cell will also increase the amount of hydrogen bubbles at the cathode which results in a greater upwards flux and a faster removal of FOG,, turbidity and colour. The removal of FOG, colour and turbidity are 98%, 92% and 91 % respectively. Meanwhile, by using Al electrodes in the same condition, the removal of FOG, colour and turbidity are 91%, 85% and 87 % respectively. Whereas by using Fe-Al as electrodes pairs, the removal of FOG, colour and turbidity are found to be at 90%, 87% and 76 % respectively. In this case, the Fe-Fe pair electrodes have been proven to provide better performance for FOG, colour and turbidity removals of slaughterhouse wastewaters. Therefore, it is feasible to be considered as an alternative method for wastewater treatment.

New UBVRI colour distributions in E-type galaxies . I. The data

NASA Astrophysics Data System (ADS)

Idiart, T. P.; Michard, R.; de Freitas Pacheco, J. A.

2002-01-01

New colour distributions have been derived from wide field UBVRI frames for 36 northern bright elliptical galaxies and a few lenticulars. The classical linear representations of colours against log r were derived, with some improvements in the accuracy of the zero point colours and of the gradients. The radial range of significant measurements was enlarged both towards the galaxy center and towards the outskirts of each object. Thus, the ``central colours'', integrated within a radius of 3\\arcsec, and the ``outermost colours'' averaged near the muV =24 surface brightness could also be obtained. Some typical deviations of colour profiles from linearity are described. Colour-colour relations of interest are presented. Very tight correlations are found between the U-V colour and the Mg2 line-index, measured either at the Galaxian center or at the effective radius. Based in part on observations collected at the Observatoire de Haute-Provence. Tables 9-11 plus detailed tables for each object are available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/383/30

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.

The influence of slope and peatland vegetation type on riverine dissolved organic carbon and water colour at different scales.

PubMed

Parry, L E; Chapman, P J; Palmer, S M; Wallage, Z E; Wynne, H; Holden, J

2015-09-15

Peatlands are important sources of fluvial carbon. Previous research has shown that riverine dissolved organic carbon (DOC) concentrations are largely controlled by soil type. However, there has been little work to establish the controls of riverine DOC within blanket peatlands that have not undergone major disturbance from drainage or burning. A total of 119 peatland catchments were sampled for riverine DOC and water colour across three drainage basins during six repeated sampling campaigns. The topographic characteristics of each catchment were determined from digital elevation models. The dominant vegetation cover was mapped using 0.5m resolution colour infrared aerial images, with ground-truthed validation revealing 82% accuracy. Forward and backward stepwise regression modelling showed that mean slope was a strong (and negative) determinant of DOC and water colour in blanket peatland river waters. There was a weak role for plant functional type in determining DOC and water colour. At the basin scale, there were major differences between the models depending on the basin. The dominance of topographic predictors of DOC found in our study, combined with a weaker role of vegetation type, paves the way for developing improved planning tools for water companies operating in peatland catchments. Using topographic data and aerial imagery it will be possible to predict which tributaries will typically yield lower DOC concentrations and which are therefore more suitable and cost-effective as raw water intakes. Copyright © 2015 Elsevier B.V. All rights reserved.

Diagnosing synaesthesia with online colour pickers: maximising sensitivity and specificity.

PubMed

Rothen, Nicolas; Seth, Anil K; Witzel, Christoph; Ward, Jamie

2013-04-30

The most commonly used method for formally assessing grapheme-colour synaesthesia (i.e., experiencing colours in response to letter and/or number stimuli) involves selecting colours from a large colour palette on several occasions and measuring consistency of the colours selected. However, the ability to diagnose synaesthesia using this method depends on several factors that have not been directly contrasted. These include the type of colour space used (e.g., RGB, HSV, CIELUV, CIELAB) and different measures of consistency (e.g., city block and Euclidean distance in colour space). This study aims to find the most reliable way of diagnosing grapheme-colour synaesthesia based on maximising sensitivity (i.e., ability of a test to identify true synaesthetes) and specificity (i.e., ability of a test to identify true non-synaesthetes). We show, applying ROC (receiver operating characteristics) to binary classification of a large sample of self-declared synaesthetes and non-synaesthetes, that the consistency criterion (i.e., cut-off value) for diagnosing synaesthesia is considerably higher than the current standard in the field. We also show that methods based on perceptual CIELUV and CIELAB colour models (rather than RGB and HSV colour representations) and Euclidean distances offer an even greater sensitivity and specificity than most currently used measures. Together, these findings offer improved heuristics for the behavioural assessment of grapheme-colour synaesthesia. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of chopping time, meat source and storage temperature on the colour of New Zealand type fresh beef sausages.

PubMed

Boles, J A; Mikkelsen, V L; Swan, J E

1998-05-01

The colour stability of finely chopped fresh sausages made from post-rigor, pre-rigor salt added (1.5% w/w) or pre-rigor no salt added beef mince was evaluated using a Hunter Miniscan (L (∗) a (∗) b (∗)) and sensory colour panel. Batters were chopped for various times and sausages stored at -1.5 °, + 4.0 ° and + 8.0 °C. Regardless of meat source or chopping time, colour stability was greatest at -1.5 °C. Panellists found the colour of all sausages stored at -1.5 °C acceptable for at least six days. Sausages made from unsalted pre-rigor mince had markedly better colour stability than those made from the other meats, especially when stored at 4 °C or 8 °C.

From spectral information to animal colour vision: experiments and concepts.

PubMed

Kelber, Almut; Osorio, Daniel

2010-06-07

Many animals use the spectral distribution of light to guide behaviour, but whether they have colour vision has been debated for over a century. Our strong subjective experience of colour and the fact that human vision is the paradigm for colour science inevitably raises the question of how we compare with other species. This article outlines four grades of 'colour vision' that can be related to the behavioural uses of spectral information, and perhaps to the underlying mechanisms. In the first, even without an (image-forming) eye, simple organisms can compare photoreceptor signals to locate a desired light environment. At the next grade, chromatic mechanisms along with spatial vision guide innate preferences for objects such as food or mates; this is sometimes described as wavelength-specific behaviour. Here, we compare the capabilities of di- and trichromatic vision, and ask why some animals have more than three spectral types of receptors. Behaviours guided by innate preferences are then distinguished from a grade that allows learning, in part because the ability to learn an arbitrary colour is evidence for a neural representation of colour. The fourth grade concerns colour appearance rather than colour difference: for instance, the distinction between hue and saturation, and colour categorization. These higher-level phenomena are essential to human colour perception but poorly known in animals, and we suggest how they can be studied. Finally, we observe that awareness of colour and colour qualia cannot be easily tested in animals.

Costs of storing colour and complex shape in visual working memory: Insights from pupil size and slow waves.

PubMed

Kursawe, Michael A; Zimmer, Hubert D

2015-06-01

We investigated the impact of perceptual processing demands on visual working memory of coloured complex random polygons during change detection. Processing load was assessed by pupil size (Exp. 1) and additionally slow wave potentials (Exp. 2). Task difficulty was manipulated by presenting different set sizes (1, 2, 4 items) and by making different features (colour, shape, or both) task-relevant. Memory performance in the colour condition was better than in the shape and both condition which did not differ. Pupil dilation and the posterior N1 increased with set size independent of type of feature. In contrast, slow waves and a posterior P2 component showed set size effects but only if shape was task-relevant. In the colour condition slow waves did not vary with set size. We suggest that pupil size and N1 indicates different states of attentional effort corresponding to the number of presented items. In contrast, slow waves reflect processes related to encoding and maintenance strategies. The observation that their potentials vary with the type of feature (simple colour versus complex shape) indicates that perceptual complexity already influences encoding and storage and not only comparison of targets with memory entries at the moment of testing. Copyright © 2015 Elsevier B.V. All rights reserved.

Frequencies of genes for coat colour and horns in Nordic cattle breeds

PubMed Central

Kantanen, Juha; Olsaker, Ingrid; Brusgaard, Klaus; Eythorsdottir, Emma; Holm, Lars-Erik; Lien, Sigbjørn; Danell, Birgitta; Adalsteinsson, Stefan

2000-01-01

Gene frequencies of coat colour and horn types were assessed in 22 Nordic cattle breeds in a project aimed at establishing genetic profiles of the breeds under study. The coat colour loci yielding information on genetic variation were: extension, agouti, spotting, brindle, dun dilution and colour sided. The polled locus was assessed for two alleles. A profound variation between breeds was observed in the frequencies of both colour and horn alleles, with the older breeds generally showing greater variation in observed colour, horn types and segregating alleles than the modern breeds. The correspondence between the present genetic distance matrix and previous molecular marker distance matrices was low (r = 0.08 – 0.12). The branching pattern of a neighbour-joining tree disagreed to some extent with the molecular data structure. The current data indicates that 70% of the total genetic variation could be explained by differences between the breeds, suggesting a much greater breed differentiation than typically found at protein and microsatellite loci. The marked differentiation of the cattle breeds and observed disagreements with the results from the previous molecular data in the topology of the phylogenetic trees are most likely a result of selection on phenotypic characters analysed in this study. PMID:14736370

The effect of polyploidy and hybridization on the evolution of floral colour in Nicotiana (Solanaceae)

PubMed Central

McCarthy, Elizabeth W.; Arnold, Sarah E. J.; Chittka, Lars; Le Comber, Steven C.; Verity, Robert; Dodsworth, Steven; Knapp, Sandra; Kelly, Laura J.; Chase, Mark W.; Baldwin, Ian T.; Kovařík, Aleš; Mhiri, Corinne; Taylor, Lin; Leitch, Andrew R.

2015-01-01

Background and Aims Speciation in angiosperms can be accompanied by changes in floral colour that may influence pollinator preference and reproductive isolation. This study investigates whether changes in floral colour can accompany polyploid and homoploid hybridization, important processes in angiosperm evolution. Methods Spectral reflectance of corolla tissue was examined for 60 Nicotiana (Solanaceae) accessions (41 taxa) based on spectral shape (corresponding to pigmentation) as well as bee and hummingbird colour perception in order to assess patterns of floral colour evolution. Polyploid and homoploid hybrid spectra were compared with those of their progenitors to evaluate whether hybridization has resulted in floral colour shifts. Key Results Floral colour categories in Nicotiana seem to have arisen multiple times independently during the evolution of the genus. Most younger polyploids displayed an unexpected floral colour, considering those of their progenitors, in the colour perception of at least one pollinator type, whereas older polyploids tended to resemble one or both of their progenitors. Conclusions Floral colour evolution in Nicotiana is weakly constrained by phylogeny, and colour shifts do occur in association with both polyploid and homoploid hybrid divergence. Transgressive floral colour in N. tabacum has arisen by inheritance of anthocyanin pigmentation from its paternal progenitor while having a plastid phenotype like its maternal progenitor. Potentially, floral colour evolution has been driven by, or resulted in, pollinator shifts. However, those polyploids that are not sympatric (on a regional scale) with their progenitor lineages are typically not divergent in floral colour from them, perhaps because of a lack of competition for pollinators. PMID:25979919

Soil cover by natural trees in agroforestry systems

NASA Astrophysics Data System (ADS)

Diaz-Ambrona, C. G. H.; Almoguera Millán, C.; Tarquis Alfonso, A.

2009-04-01

The dehesa is common agroforestry system in the Iberian Peninsula. These open oak parklands with silvo-pastoral use cover about two million hectares. Traditionally annual pastures have been grazed by cows, sheep and also goats while acorns feed Iberian pig diet. Evergreen oak (Quercus ilex L.) has other uses as fuelwood collection and folder after tree pruning. The hypothesis of this work is that tree density and canopy depend on soil types. We using the spanish GIS called SIGPAC to download the images of dehesa in areas with different soil types. True colour images were restoring to a binary code, previously canopy colour range was selected. Soil cover by tree canopy was calculated and number of trees. Processing result was comparable to real data. With these data we have applied a dynamic simulation model Dehesa to determine evergreen oak acorn and annual pasture production. The model Dehesa is divided into five submodels: Climate, Soil, Evergreen oak, Pasture and Grazing. The first three require the inputs: (i) daily weather data (maximum and minimum temperatures, precipitation and solar radiation); (ii) the soil input parameters for three horizons (thickness, field capacity, permanent wilting point, and bulk density); and (iii) the tree characterization of the dehesa (tree density, canopy diameter and height, and diameter of the trunk). The influence of tree on pasture potential production is inversely proportional to the canopy cover. Acorn production increase with tree canopy cover until stabilizing itself, and will decrease if density becomes too high (more than 80% soil tree cover) at that point there is competition between the trees. Main driving force for dehesa productivity is soil type for pasture, and tree cover for acorn production. Highest pasture productivity was obtained on soil Dystric Planosol (Alfisol), Dystric Cambisol and Chromo-calcic-luvisol, these soils only cover 22.4% of southwest of the Iberian peninssula. Lowest productivity was obtained on Dystric Lithosol.

Effect of light, packaging condition and dark storage durations on colour and lipid oxidative stability of cooked ham.

PubMed

Haile, Demewez Moges; De Smet, Stefaan; Claeys, Erik; Vossen, Els

2013-04-01

The colour and lipid oxidative stability of sliced cooked ham stored at 4 °C were studied in relation to dark storage duration, lighting and packaging conditions. Colour stability was monitored by instrumental colour measurement (CIE L*a*b* colour space) whereas lipid stability was measured by the determination of the 2-thiobarbituric acid reactive substances (TBARS). A significantly higher discoloration observed in products wrapped in foil and kept in light than products wrapped in foil and kept in dark. Colour loss was estimated by loss of redness (a*), a*/b*, nitrosomyoglobin, chroma (C); or increase of lightness (L*), MetMb, hue angle (H°). Colour loss was more dependent upon photochemical process than dark storage duration and packaging types. Lipid oxidation was not significantly affected by light exposure. However lipid oxidation was significantly affected by dark storage duration as noticed from better lipid stability of products stored for short duration in dark. Better colour stability was observed on products packed in MAP with less residual oxygen.

Thresholds and noise limitations of colour vision in dim light

PubMed Central

Yovanovich, Carola

2017-01-01

Colour discrimination is based on opponent photoreceptor interactions, and limited by receptor noise. In dim light, photon shot noise impairs colour vision, and in vertebrates, the absolute threshold of colour vision is set by dark noise in cones. Nocturnal insects (e.g. moths and nocturnal bees) and vertebrates lacking rods (geckos) have adaptations to reduce receptor noise and use chromatic vision even in very dim light. In contrast, vertebrates with duplex retinae use colour-blind rod vision when noisy cone signals become unreliable, and their transition from cone- to rod-based vision is marked by the Purkinje shift. Rod–cone interactions have not been shown to improve colour vision in dim light, but may contribute to colour vision in mesopic light intensities. Frogs and toads that have two types of rods use opponent signals from these rods to control phototaxis even at their visual threshold. However, for tasks such as prey or mate choice, their colour discrimination abilities fail at brighter light intensities, similar to other vertebrates, probably limited by the dark noise in cones. This article is part of the themed issue 'Vision in dim light’. PMID:28193810

Effects of coloured lighting on the perception of interior spaces.

PubMed

Odabaşioğlu, Seden; Olguntürk, Nіlgün

2015-02-01

Use of coloured lighting in interior spaces has become prevalent in recent years. Considerable importance is ascribed to coloured lighting in interior and lighting design. The effects of colour on the perception of interior spaces have been studied as surface colour; but here, the effects of three different types of chromatic light were investigated. The lighting differed in colour (red, green and white) and perceptions of interior space were assessed. 97 participants (59 women, 38 men; M age = 21.4 yr.) evaluated the experiment room on a questionnaire assessing eight evaluative factors: Pleasantness, Arousal, Aesthetics, Usefulness, Comfort, Spaciousness, Colour, and Lighting quality. Perceptions of the room differed by colour of lighting for some of the evaluative factors, but there was no sex difference in perceptions. Interior spaces may be perceived as equally pleasant under white, green and red lighting. Under white lighting a space is perceived as more useful, spacious, clear, and luminous. Green lighting would make the same effect. Green and white lighting were perceived equally comfortable in an interior space. Chromatic coloured lighting was perceived to be more aesthetic than white lighting. The results support previous findings for some evaluative factors, but differed for others.

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).

Psychophysiological evidence for the genuineness of swimming-style colour synaesthesia.

PubMed

Rothen, Nicolas; Nikolić, Danko; Jürgens, Uta Maria; Mroczko-Wąsowicz, Aleksandra; Cock, Josephine; Meier, Beat

2013-03-01

Recently, swimming-style colour synaesthesia was introduced as a new form of synaesthesia. A synaesthetic Stroop test was used to establish its genuineness. Since Stroop interference can occur for any type of overlearned association, in the present study we used a modified Stroop test and psychophysiological synaesthetic conditioning to further establish the genuineness of this form of synaesthesia. We compared the performance of a swimming-style colour synaesthete and a control who was trained on swimming-style colour associations. Our results showed that behavioural aspects of swimming-style colour synaesthesia can be mimicked in a trained control. Importantly, however, our results showed a psychophysiological conditioning effect for the synaesthete only. We discuss the theoretical relevance of swimming-style colour synaesthesia according to different models of synaesthesia. We conclude that swimming-style colour synaesthesia is a genuine form of synaesthesia, can be mimicked behaviourally in non-synaesthetes, and is best explained by a re-entrant feedback model. Copyright © 2012 Elsevier Inc. All rights reserved.

Colour stability of aesthetic brackets: ceramic and plastic.

PubMed

Filho, Hibernon Lopes; Maia, Lúcio Henrique; Araújo, Marcus V; Eliast, Carlos Nelson; Ruellas, Antônio Carlos O

2013-05-01

The colour stability of aesthetic brackets may differ according to their composition, morphology and surface property, which may consequently influence their aesthetic performance. To assess the colour stability of aesthetic brackets (ceramic and plastic) after simulating aging and staining. Twelve commercially manufactured ceramic brackets and four different plastic brackets were assessed. To determine possible colour change (change of E*(ab)) and the value of the NBS (National Bureau of Standards) unit system, spectrophotometric colour measurements for CIE L*, a* and b* were taken before and after the brackets were aged and stained. Statistical analysis was undertaken using a one-way ANOVA analysis of variance and a Tukey multiple comparison test (alpha = 0.05). The colour change between the various (ceramic and plastic) materials was not significant (p > 0.05), but still varied significantly (p < 0.001) between the brackets of the same composition or crystalline structure and among commercial brands. Colour stability cannot be confirmed simply by knowing the type of material and crystalline composition or structure.

Marked colour divergence in the gliding membranes of a tropical lizard mirrors population differences in the colour of falling leaves.

PubMed

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

2014-12-01

Populations of the Bornean gliding lizard, Draco cornutus, differ markedly in the colour of their gliding membranes. They also differ in local vegetation type (mangrove forest versus lowland rainforest) and consequently, the colour of falling leaves (red and brown/black in mangrove versus green, brown and black in rainforest). We show that the gliding membranes of these lizards closely match the colours of freshly fallen leaves in the local habitat as they appear to the visual system of birds (their probable predators). Furthermore, gliding membranes more closely resembled colours of local fallen leaves than standing foliage or fallen leaves in the other population's habitat. This suggests that the two populations have diverged in gliding membrane coloration to match the colours of their local falling leaves, and that mimicking falling leaves is an adaptation that functions to reduce predation by birds. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Camouflage through colour change: mechanisms, adaptive value and ecological significance

PubMed Central

Flores, Augusto A. V.

2017-01-01

Animals from a wide range of taxonomic groups are capable of colour change, of which camouflage is one of the main functions. A considerable amount of past work on this subject has investigated species capable of extremely rapid colour change (in seconds). However, relatively slow colour change (over hours, days, weeks and months), as well as changes arising via developmental plasticity are probably more common than rapid changes, yet less studied. We discuss three key areas of colour change and camouflage. First, we review the mechanisms underpinning colour change and developmental plasticity for camouflage, including cellular processes, visual feedback, hormonal control and dietary factors. Second, we discuss the adaptive value of colour change for camouflage, including the use of different camouflage types. Third, we discuss the evolutionary–ecological implications of colour change for concealment, including what it can tell us about intraspecific colour diversity, morph-specific strategies, and matching to different environments and microhabitats. Throughout, we discuss key unresolved questions and present directions for future work, and highlight how colour change facilitates camouflage among habitats and arises when animals are faced with environmental changes occurring over a range of spatial and temporal scales. This article is part of the themed issue ‘Animal coloration: production, perception, function and application’. PMID:28533459

Personality predicts the vibrancy of colour imagery: The case of synaesthesia.

PubMed

Hossain, Shyla R; Simner, Julia; Ipser, Alberta

2017-07-01

In this study we show that personality traits predict the physical qualities of mentally generated colours, using the case of synaesthesia. Developmental grapheme-colour synaesthetes have the automatic lifelong association of colours paired to letters or digits. Although these colours are internal mental constructs, they can be measured along physical dimensions such as saturation and luminance. The personality of synaesthetes can also be quantified using self-report questionnaires relating, for example, to the five major traits of Conscientiousness, Extraversion, Agreeableness, Neuroticism, and Openness to Experience. In this paper, we bring together both types of quality by examining whether the personality of individual synaesthetes predicts their synaesthetic colours. Twenty grapheme-colour synaesthetes were tested with the Big Five Inventory (BFI) personality questionnaire. Their synaesthesia was also tested in terms of consistency and average colour saturation and luminance. Two major results were found: although personality did not influence the overall robustness (i.e., consistency) of synaesthesia, it predicted the nature of synaesthetes' colours: the trait of Openness was positively correlated with the saturation of synaesthetic colours. Our study provides evidence that personality and internal perception are intertwined, and suggests future avenues of research for investigating the associations between the two. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tooth colour change with Ozicure Oxygen Activator: a comparative in vitro tooth bleaching study.

PubMed

Grundlingh, A A; Grossman, E S; Witcomb, M J

2012-08-01

This in vitro study compared a new tooth bleaching product, Ozicure Oxygen Activator (O3, RSA) with Opalescence Quick (Ultradent, USA) using a randomised block design to assess tooth colour change. Colour change, stability and relapse in canine, incisor and premolar teeth was assessed following three bleach treatments and subsequent tooth colour assessment. Ninety nine teeth (canines, incisors and premolars), which were caries free, had no surface defects and were within the colour range 1M2 and 5M3 were selected. Teeth were randomly divided into the three experimental groups: Opalescence Quick, Ozicure Oxygen Activator and control. The three experimental groups received three treatments of one hour each over three consecutive days. Tooth colour was assessed using the Vitapan 3D Master Tooth Guide (VITA, Germany). A General Linear Models test for analysis of variance for a fractional design with significance set at P < 0.05 was used to test for significance. Both bleaching methods significantly lightened the teeth (P < 0.0001). Tooth colour change was mainly after the first hour of tooth bleaching. The tooth type was significant in tooth colour change (P = 0.0416). Tooth colour relapse and resistance to colour change were observed. Ozicure Oxygen Activator bleached teeth in a manner and to an extent similar to Opalescence Quick.

Camouflage through colour change: mechanisms, adaptive value and ecological significance.

PubMed

Duarte, Rafael C; Flores, Augusto A V; Stevens, Martin

2017-07-05

Animals from a wide range of taxonomic groups are capable of colour change, of which camouflage is one of the main functions. A considerable amount of past work on this subject has investigated species capable of extremely rapid colour change (in seconds). However, relatively slow colour change (over hours, days, weeks and months), as well as changes arising via developmental plasticity are probably more common than rapid changes, yet less studied. We discuss three key areas of colour change and camouflage. First, we review the mechanisms underpinning colour change and developmental plasticity for camouflage, including cellular processes, visual feedback, hormonal control and dietary factors. Second, we discuss the adaptive value of colour change for camouflage, including the use of different camouflage types. Third, we discuss the evolutionary-ecological implications of colour change for concealment, including what it can tell us about intraspecific colour diversity, morph-specific strategies, and matching to different environments and microhabitats. Throughout, we discuss key unresolved questions and present directions for future work, and highlight how colour change facilitates camouflage among habitats and arises when animals are faced with environmental changes occurring over a range of spatial and temporal scales.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Authors.

Behavioural evidence for colour vision in an elasmobranch.

PubMed

Van-Eyk, Sarah M; Siebeck, Ulrike E; Champ, Connor M; Marshall, Justin; Hart, Nathan S

2011-12-15

Little is known about the sensory abilities of elasmobranchs (sharks, skates and rays) compared with other fishes. Despite their role as apex predators in most marine and some freshwater habitats, interspecific variations in visual function are especially poorly studied. Of particular interest is whether they possess colour vision and, if so, the role(s) that colour may play in elasmobranch visual ecology. The recent discovery of three spectrally distinct cone types in three different species of ray suggests that at least some elasmobranchs have the potential for functional trichromatic colour vision. However, in order to confirm that these species possess colour vision, behavioural experiments are required. Here, we present evidence for the presence of colour vision in the giant shovelnose ray (Glaucostegus typus) through the use of a series of behavioural experiments based on visual discrimination tasks. Our results show that these rays are capable of discriminating coloured reward stimuli from other coloured (unrewarded) distracter stimuli of variable brightness with a success rate significantly different from chance. This study represents the first behavioural evidence for colour vision in any elasmobranch, using a paradigm that incorporates extensive controls for relative stimulus brightness. The ability to discriminate colours may have a strong selective advantage for animals living in an aquatic ecosystem, such as rays, as a means of filtering out surface-wave-induced flicker.

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%).

Red-green colour blindness in Singaporean children.

PubMed

Chia, Audrey; Gazzard, Gus; Tong, Louis; Zhang, Xiaoe; Sim, Ee-Ling; Fong, Allan; Mei Saw, Seang

2008-07-01

X-linked red-green colour blindness is the most common form of colour blindness. Various studies suggest that, worldwide, 2-8% of men are afflicted with this condition. The purpose of this study is to determine the prevalence of red-green colour blindness in Singaporean schoolchildren. A total of 1249 children aged 13-15 years were screened using the Ishihara 24-plate edition book during the School Cohort study of the Risk factors for Myopia visit. A total of 1210 children (96.8%) managed to correctly identify at least 13 of the initial 15 plates and were deemed to have normal colour vision.Thirty-three children (32 boys, one girl) were only able to identify nine or less plates and were considered to be colour blind. Overall, 5.4% (95% confidence interval 3%, 7%) of Chinese, 4.9% (1%, 9%) of Malay and 4.9% (2%, 11%) of Indian boys were colour blind (P = 0.97). Classification plates 16-17 were useful in determining deutran or protan tendencies in only 14 (43%) of the 33 children identified as being colour blind. 5.3% of boys and 0.2% of girls were found to be colour blind in this Singapore-based study. Although the Ishihara test proved useful in identifying colour-blind children, other tests are required to accurately classify the types of red-green colour blindness in these children.

Structurally coloured secondary particles composed of black and white colloidal particles.

PubMed

Takeoka, Yukikazu; Yoshioka, Shinya; Teshima, Midori; Takano, Atsushi; Harun-Ur-Rashid, Mohammad; Seki, Takahiro

2013-01-01

This study investigated the colourful secondary particles formed by controlling the aggregation states of colloidal silica particles and the enhancement of the structural colouration of the secondary particles caused by adding black particles. We obtained glossy, partially structurally coloured secondary particles in the absence of NaCl, but matte, whitish secondary particles were obtained in the presence of NaCl. When a small amount of carbon black was incorporated into both types of secondary particles, the incoherent multiple scattering of light from the amorphous region was considerably reduced. However, the peak intensities in the reflection spectra, caused by Bragg reflection and by coherent single wavelength scattering, were only slightly decreased. Consequently, a brighter structural colour of these secondary particles was observed with the naked eye. Furthermore, when magnetite was added as a black particle, the coloured secondary particles could be moved and collected by applying an external magnetic field.

Structurally Coloured Secondary Particles Composed of Black and White Colloidal Particles

PubMed Central

Takeoka, Yukikazu; Yoshioka, Shinya; Teshima, Midori; Takano, Atsushi; Harun-Ur-Rashid, Mohammad; Seki, Takahiro

2013-01-01

This study investigated the colourful secondary particles formed by controlling the aggregation states of colloidal silica particles and the enhancement of the structural colouration of the secondary particles caused by adding black particles. We obtained glossy, partially structurally coloured secondary particles in the absence of NaCl, but matte, whitish secondary particles were obtained in the presence of NaCl. When a small amount of carbon black was incorporated into both types of secondary particles, the incoherent multiple scattering of light from the amorphous region was considerably reduced. However, the peak intensities in the reflection spectra, caused by Bragg reflection and by coherent single wavelength scattering, were only slightly decreased. Consequently, a brighter structural colour of these secondary particles was observed with the naked eye. Furthermore, when magnetite was added as a black particle, the coloured secondary particles could be moved and collected by applying an external magnetic field. PMID:23917891

Self-reported skin colour and erythemal sensitivity vs. objectively measured constitutive skin colour in an African population with predominantly dark skin.

PubMed

Wright, Caradee Y; Wilkes, Marcus; du Plessis, Johan L; Reeder, Anthony I

2015-11-01

Skin colour is an important factor in skin-related diseases. Accurate determination of skin colour is important for disease prevention and supporting healthy sun behaviour, yet such data are lacking for dark skin types. Self-perceived, natural skin colour and sun-skin reaction were compared with objectively measured skin colour among an African population with predominantly dark skin. Unexposed skin of 556 adults (70.1% Black) was measured with a reflectance spectrophotometer to calculate an individual typology angle (°ITA). Participants reported self-perceived skin colour and erythemal sensitivity. There was a strong, positive monotonic correlation between self-reported and measured skin colour (Spearman ρ = 0.6438, P < 0.001), but only a weak correlation between self-reported erythemal sensitivity and measured skin colour (Spearman ρ = 0.2713, P < 0.001). Self-report biases in underestimation and overestimation of skin colour were evident. Many participants with 'dark brown' and 'black' skin had difficulty in classifying erythemal sensitivity. In Africa, self-reported skin colour could potentially be used in lieu of spectrophotometer measurements, but options for questions on sunburn and tanning require suitable adjustment. Our study provides evidence of range in °ITA values among residents in Africa and reinforces previous results that self-report may be reliable for determining skin colour, but not erythemal sensitivity, for dark skin individuals. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The colour-magnitude relation as a constraint on the formation of rich cluster galaxies

NASA Astrophysics Data System (ADS)

Bower, Richard G.; Kodama, Tadayuki; Terlevich, Ale

1998-10-01

The colours and magnitudes of early-type galaxies in galaxy clusters are strongly correlated. The existence of such a correlation has been used to infer that early-type galaxies must be old passively evolving systems. Given the dominance of early-type galaxies in the cores of rich clusters, this view sits uncomfortably with the increasing fraction of blue galaxies found in clusters at intermediate redshifts, and with the late formation of galaxies favoured by cold dark matter type cosmologies. In this paper, we make a detailed investigation of these issues and examine the role that the colour-magnitude relation can play in constraining the formation history of galaxies currently found in the cores of rich clusters. We start by considering the colour evolution of galaxies after star formation ceases. We show that the scatter of the colour-magnitude relation places a strong constraint on the spread in age that is allowed for the bulk of the stellar population. In the extreme case that the stars are formed in a single event, the spread in age cannot be more than 4 Gyr. Although the bulk of stars must be formed in a short period, continuing formation of stars in a fraction of the galaxies is not so strongly constrained. We examine a model in which star formation occurs over an extended period of time in most galaxies with star formation being truncated randomly. This model is consistent with the formation of stars in a few systems until look-back times of ~5Gyr. An extension of this type of star formation history allows us to reconcile the small present-day scatter of the colour-magnitude relation with the observed blue galaxy fractions of intermediate redshift galaxy clusters. In addition to setting a limit on the variations in luminosity-weighted age between the stellar populations of cluster galaxies, the colour-magnitude relation can also be used to constrain the degree of merging between pre-existing stellar systems. This test relies on the slope of the colour-magnitude relation: mergers between galaxies of unequal mass tend to reduce the slope of the relation and to increase its scatter. We show that random mergers between galaxies very rapidly remove any well-defined colour-magnitude correlation. This model is not physically motivated, however, and we prefer to examine the merger process using a self-consistent merger tree. In such a model there are two effects. First, massive galaxies preferentially merge with systems of similar mass. Secondly, the rate of mass growth is considerably smaller than for the random merger case. As a result of both of these effects, the colour-magnitude correlation persists through a larger number of merger steps. The passive evolution of galaxy colours and their averaging in dissipationless mergers provide opposing constraints on the formation of cluster galaxies in a hierarchical model. At the level of current constraints, a compromise solution appears possible. The bulk of the stellar population must have formed before z=1, but cannot have formed in mass units much less than about half the mass of a present-day L_* galaxy. In this case, the galaxies are on average old enough that stellar population evolution is weak, yet formed recently enough that mass growth resulting from mergers is small.

The effect of polyploidy and hybridization on the evolution of floral colour in Nicotiana (Solanaceae).

PubMed

McCarthy, Elizabeth W; Arnold, Sarah E J; Chittka, Lars; Le Comber, Steven C; Verity, Robert; Dodsworth, Steven; Knapp, Sandra; Kelly, Laura J; Chase, Mark W; Baldwin, Ian T; Kovařík, Aleš; Mhiri, Corinne; Taylor, Lin; Leitch, Andrew R

2015-06-01

Speciation in angiosperms can be accompanied by changes in floral colour that may influence pollinator preference and reproductive isolation. This study investigates whether changes in floral colour can accompany polyploid and homoploid hybridization, important processes in angiosperm evolution. Spectral reflectance of corolla tissue was examined for 60 Nicotiana (Solanaceae) accessions (41 taxa) based on spectral shape (corresponding to pigmentation) as well as bee and hummingbird colour perception in order to assess patterns of floral colour evolution. Polyploid and homoploid hybrid spectra were compared with those of their progenitors to evaluate whether hybridization has resulted in floral colour shifts. Floral colour categories in Nicotiana seem to have arisen multiple times independently during the evolution of the genus. Most younger polyploids displayed an unexpected floral colour, considering those of their progenitors, in the colour perception of at least one pollinator type, whereas older polyploids tended to resemble one or both of their progenitors. Floral colour evolution in Nicotiana is weakly constrained by phylogeny, and colour shifts do occur in association with both polyploid and homoploid hybrid divergence. Transgressive floral colour in N. tabacum has arisen by inheritance of anthocyanin pigmentation from its paternal progenitor while having a plastid phenotype like its maternal progenitor. Potentially, floral colour evolution has been driven by, or resulted in, pollinator shifts. However, those polyploids that are not sympatric (on a regional scale) with their progenitor lineages are typically not divergent in floral colour from them, perhaps because of a lack of competition for pollinators. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Carotenoid accumulation in orange-pigmented Capsicum annuum fruit, regulated at multiple levels

PubMed Central

Rodriguez-Uribe, Laura; Guzman, Ivette; Rajapakse, Wathsala; Richins, Richard D.; O’Connell, Mary A.

2012-01-01

The pericarp of Capsicum fruit is a rich dietary source of carotenoids. Accumulation of these compounds may be controlled, in part, by gene transcription of biosynthetic enzymes. The carotenoid composition in a number of orange-coloured C. annuum cultivars was determined using HPLC and compared with transcript abundances for four carotenogenic enzymes, Psy, LcyB, CrtZ-2, and Ccs determined by qRT-PCR. There were unique carotenoid profiles as well as distinct patterns of transcription of carotenogenic enzymes within the seven orange-coloured cultivars. In one cultivar, ‘Fogo’, carrying the mutant ccs-3 allele, transcripts were detected for this gene, but no CCS protein accumulated. The premature stop termination in ccs-3 prevented expression of the biosynthetic activity to synthesize the capsanthin and capsorubin forms of carotenoids. In two other orange-coloured cultivars, ‘Orange Grande’ and ‘Oriole’, both with wild-type versions of all four carotenogenic enzymes, no transcripts for Ccs were detected and no red pigments accumulated. Finally, in a third case, the orange-coloured cultivar, Canary, transcripts for all four of the wild-type carotenogenic enzymes were readily detected yet no CCS protein appeared to accumulate and no red carotenoids were synthesized. In the past, mutations in Psy and Ccs have been identified as the loci controlling colour in the fruit. Now there is evidence that a non-structural gene may control colour development in Capsicum. PMID:21948863

Carotenoid accumulation in orange-pigmented Capsicum annuum fruit, regulated at multiple levels.

PubMed

Rodriguez-Uribe, Laura; Guzman, Ivette; Rajapakse, Wathsala; Richins, Richard D; O'Connell, Mary A

2012-01-01

The pericarp of Capsicum fruit is a rich dietary source of carotenoids. Accumulation of these compounds may be controlled, in part, by gene transcription of biosynthetic enzymes. The carotenoid composition in a number of orange-coloured C. annuum cultivars was determined using HPLC and compared with transcript abundances for four carotenogenic enzymes, Psy, LcyB, CrtZ-2, and Ccs determined by qRT-PCR. There were unique carotenoid profiles as well as distinct patterns of transcription of carotenogenic enzymes within the seven orange-coloured cultivars. In one cultivar, 'Fogo', carrying the mutant ccs-3 allele, transcripts were detected for this gene, but no CCS protein accumulated. The premature stop termination in ccs-3 prevented expression of the biosynthetic activity to synthesize the capsanthin and capsorubin forms of carotenoids. In two other orange-coloured cultivars, 'Orange Grande' and 'Oriole', both with wild-type versions of all four carotenogenic enzymes, no transcripts for Ccs were detected and no red pigments accumulated. Finally, in a third case, the orange-coloured cultivar, Canary, transcripts for all four of the wild-type carotenogenic enzymes were readily detected yet no CCS protein appeared to accumulate and no red carotenoids were synthesized. In the past, mutations in Psy and Ccs have been identified as the loci controlling colour in the fruit. Now there is evidence that a non-structural gene may control colour development in Capsicum.

Yellow and the Novel Aposematic Signal, Red, Protect Delias Butterflies from Predators

PubMed Central

Wee, Jocelyn Liang Qi

2017-01-01

Butterflies of the South Asian and Australian genus Delias possess striking colours on the ventral wings that are presumed to serve as warning signals to predators. However, this has not been shown empirically. Here we experimentally tested whether the colours of one member of this diverse genus, Delias hyparete, function as aposematic signals. We constructed artificial paper models with either a faithful colour representation of D. hyparete, or with all of its colours converted to grey scale. We also produced models where single colours were left intact, while others were converted to grey-scale or removed entirely. We placed all model types simultaneously in the field, attached to a live mealworm, and measured relative attack rates at three separate field sites. Faithful models of D. hyparete, suffered the least amount of attacks, followed by grey-scale models with unaltered red patches, and by grey-scale models with unaltered yellow patches. We conclude that red and yellow colours function as warning signals. By mapping dorsal and ventral colouration onto a phylogeny of Delias, we observed that yellow and red colours appear almost exclusively on the ventral wing surfaces, and that basal lineages have mostly yellow, white, and black wings, whereas derived lineages contain red colour in addition to the other colours. Red appears to be, thus, a novel adaptive trait in this lineage of butterflies. PMID:28060944

Yellow and the Novel Aposematic Signal, Red, Protect Delias Butterflies from Predators.

PubMed

Wee, Jocelyn Liang Qi; Monteiro, Antónia

2017-01-01

Butterflies of the South Asian and Australian genus Delias possess striking colours on the ventral wings that are presumed to serve as warning signals to predators. However, this has not been shown empirically. Here we experimentally tested whether the colours of one member of this diverse genus, Delias hyparete, function as aposematic signals. We constructed artificial paper models with either a faithful colour representation of D. hyparete, or with all of its colours converted to grey scale. We also produced models where single colours were left intact, while others were converted to grey-scale or removed entirely. We placed all model types simultaneously in the field, attached to a live mealworm, and measured relative attack rates at three separate field sites. Faithful models of D. hyparete, suffered the least amount of attacks, followed by grey-scale models with unaltered red patches, and by grey-scale models with unaltered yellow patches. We conclude that red and yellow colours function as warning signals. By mapping dorsal and ventral colouration onto a phylogeny of Delias, we observed that yellow and red colours appear almost exclusively on the ventral wing surfaces, and that basal lineages have mostly yellow, white, and black wings, whereas derived lineages contain red colour in addition to the other colours. Red appears to be, thus, a novel adaptive trait in this lineage of butterflies.

The prevalence of tooth discolouration and the self-satisfaction with tooth colour in a Chinese urban population.

PubMed

Xiao, J; Zhou, X D; Zhu, W C; Zhang, B; Li, J Y; Xu, X

2007-05-01

To determine the prevalence of tooth discolouration, self-satisfaction with tooth colour, and correlation with socio-demographic-behavioural factors in adults and teenagers in Chengdu, China. A cross-sectional survey. 405 Chinese urban adults and teenagers from a multistage random probability sample. Tooth colour was measured on the maxillary central incisors using a colorimeter. Tooth discolouration was determined according to the discolouration level figure and evaluation criteria. Self-satisfaction with tooth colour was assessed on a five-point qualitative scale. Data were coded and analyzed using SPSS software. The mean values for L*, a* and b* were 70.67 (s.d. 1.91), 4.29 (s.d. 2.05) and 17.51 (s.d. 4.13), respectively. Age and sex were the most important factors associated with tooth colour (P < 0.05). About half of the study population (48.9%) suffered from some tooth discolouration, and 52.6% were dissatisfied with their tooth colour. Education and smoking were significant factors affecting self-satisfaction with tooth colour (P < 0.05). Tooth discolouration is common among the Chinese, and many Chinese are dissatisfied with their tooth colour. Self-satisfaction with tooth colour decreased with increasing severity of discolouration. Further research is needed to determine types of tooth discolouration among broader regions in China.

The transcriptional landscape of seasonal coat colour moult in the snowshoe hare.

PubMed

Ferreira, Mafalda S; Alves, Paulo C; Callahan, Colin M; Marques, João P; Mills, L Scott; Good, Jeffrey M; Melo-Ferreira, José

2017-08-01

Seasonal coat colour change is an important adaptation to seasonally changing environments but the evolution of this and other circannual traits remains poorly understood. In this study, we use gene expression to understand seasonal coat colour moulting in wild snowshoe hares (Lepus americanus). We used hair colour to follow the progression of the moult, simultaneously sampling skin from three moulting stages in hares collected during the peak of the spring moult from white winter to brown summer pelage. Using RNA sequencing, we tested whether patterns of expression were consistent with predictions based on the established phases of the hair growth cycle. We found functionally consistent clustering across skin types, with 766 genes differentially expressed between moult stages. "White" pelage showed more differentially expressed genes that were upregulated relative to other skin types, involved in the transition between late telogen (quiescent stage) and the onset of anagen (proliferative stage). Skin samples from transitional "intermediate" and "brown" pelage were transcriptionally similar and resembled the regressive transition to catagen (regressive stage). We also detected differential expression of several key circadian clock and pigmentation genes, providing important means to dissect the bases of alternate seasonal colour morphs. Our results reveal that pelage colour is a useful biomarker for seasonal change but that there is a consistent lag between the main gene expression waves and change in visible coat colour. These experiments establish that developmental sampling from natural populations of nonmodel organisms can provide a crucial resource to dissect the genetic basis and evolution of complex seasonally changing traits. © 2017 John Wiley & Sons Ltd.

Behavioural, ecological, and evolutionary aspects of diversity in frog colour patterns.

PubMed

Rojas, Bibiana

2017-05-01

The role of colours and colour patterns in behavioural ecology has been extensively studied in a variety of contexts and taxa, while almost overlooked in many others. For decades anurans have been the focus of research on acoustic signalling due to the prominence of vocalisations in their communication. Much less attention has been paid to the enormous diversity of colours, colour patterns, and other types of putative visual signals exhibited by frogs. With the exception of some anecdotal observations and studies, the link between colour patterns and the behavioural and evolutionary ecology of anurans had not been addressed until approximately two decades ago. Since then, there has been ever-increasing interest in studying how colouration is tied to different aspects of frog behaviour, ecology and evolution. Here I review the literature on three different contexts in which frog colouration has been recently studied: predator-prey interactions, intraspecific communication, and habitat use; and I highlight those aspects that make frogs an excellent, yet understudied, group to examine the role of colour in the evolution of anti-predation strategies and animal communication systems. Further, I argue that in addition to natural-history observations, more experiments are needed in order to elucidate the functions of anuran colouration and the selective pressures involved in its diversity. To conclude, I encourage researchers to strengthen current experimental approaches, and suggest future directions that may broaden our current understanding of the adaptive value of anuran colour pattern diversity. © 2016 Cambridge Philosophical Society.

Colour changes by laser irradiation of reddish building limestones

NASA Astrophysics Data System (ADS)

Grossi, C. M.; Benavente, D.

2016-10-01

We have used X-ray photoelectron spectroscopy (XPS) as a novel method to investigate the causes of colour changes in a reddish limestone under irradiation by a Q-switched Nd:YAG 1064 nm laser. We irradiated clean dry and wet surfaces of Pidramuelle Roja, a building stone frequently used in the Asturian heritage, at fluences ranging from 0.12 to 1.47 J cm-2. We measured the colour coordinates and undertook XPS analysis of the state of oxidation of iron both before and after irradiation. Visible colour changes and potential aesthetic damage occurred on dry surfaces from a fluence of 0.31 J cm-2, with the stone showing a greening effect and very intense darkening. The colour change on dry surfaces was considerably higher than on wet surfaces, which at the highest fluence (1.47 J cm-2) was also above the human visual detection threshold. The use of XPS demonstrated that the change in colour (chroma and hue) is associated with a reduction in the iron oxidation state on dry surfaces during laser irradiation. This points out to a potential routinary use of XPS to analyse causes of colour changes during laser cleaning in other types of coloured building stones.

Thresholds and noise limitations of colour vision in dim light.

PubMed

Kelber, Almut; Yovanovich, Carola; Olsson, Peter

2017-04-05

Colour discrimination is based on opponent photoreceptor interactions, and limited by receptor noise. In dim light, photon shot noise impairs colour vision, and in vertebrates, the absolute threshold of colour vision is set by dark noise in cones. Nocturnal insects (e.g. moths and nocturnal bees) and vertebrates lacking rods (geckos) have adaptations to reduce receptor noise and use chromatic vision even in very dim light. In contrast, vertebrates with duplex retinae use colour-blind rod vision when noisy cone signals become unreliable, and their transition from cone- to rod-based vision is marked by the Purkinje shift. Rod-cone interactions have not been shown to improve colour vision in dim light, but may contribute to colour vision in mesopic light intensities. Frogs and toads that have two types of rods use opponent signals from these rods to control phototaxis even at their visual threshold. However, for tasks such as prey or mate choice, their colour discrimination abilities fail at brighter light intensities, similar to other vertebrates, probably limited by the dark noise in cones.This article is part of the themed issue 'Vision in dim light'. © 2017 The Author(s).

Gene therapy for red-green colour blindness in adult primates

PubMed Central

Mancuso, Katherine; Hauswirth, William W.; Li, Qiuhong; Connor, Thomas B.; Kuchenbecker, James A.; Mauck, Matthew C.; Neitz, Jay; Neitz, Maureen

2009-01-01

Red-green colour blindness, which results from the absence of either the long- (L) or middle- (M) wavelength-sensitive visual photopigments, is the most common single locus genetic disorder. Here, the possibility of curing colour blindness using gene therapy was explored in experiments on adult monkeys that had been colour blind since birth. A third type of cone pigment was added to dichromatic retinas, providing the receptoral basis for trichromatic colour vision. This opened a new avenue to explore the requirements for establishing the neural circuits for a new dimension of colour sensation. Classic visual deprivation experiments1 have led to the expectation that neural connections established during development would not appropriately process an input that was not present from birth. Therefore, it was believed that treatment of congenital vision disorders would be ineffective unless administered to the very young. Here, however, addition of a third opsin in adult red-green colour-deficient primates was sufficient to produce trichromatic colour vision behaviour. Thus, trichromacy can arise from a single addition of a third cone class and it does not require an early developmental process. This provides a positive outlook for the potential of gene therapy to cure adult vision disorders. PMID:19759534

Gene therapy for red-green colour blindness in adult primates.

PubMed

Mancuso, Katherine; Hauswirth, William W; Li, Qiuhong; Connor, Thomas B; Kuchenbecker, James A; Mauck, Matthew C; Neitz, Jay; Neitz, Maureen

2009-10-08

Red-green colour blindness, which results from the absence of either the long- (L) or the middle- (M) wavelength-sensitive visual photopigments, is the most common single locus genetic disorder. Here we explore the possibility of curing colour blindness using gene therapy in experiments on adult monkeys that had been colour blind since birth. A third type of cone pigment was added to dichromatic retinas, providing the receptoral basis for trichromatic colour vision. This opened a new avenue to explore the requirements for establishing the neural circuits for a new dimension of colour sensation. Classic visual deprivation experiments have led to the expectation that neural connections established during development would not appropriately process an input that was not present from birth. Therefore, it was believed that the treatment of congenital vision disorders would be ineffective unless administered to the very young. However, here we show that the addition of a third opsin in adult red-green colour-deficient primates was sufficient to produce trichromatic colour vision behaviour. Thus, trichromacy can arise from a single addition of a third cone class and it does not require an early developmental process. This provides a positive outlook for the potential of gene therapy to cure adult vision disorders.

Cat colour vision: evidence for more than one cone process

PubMed Central

Daw, N. W.; Pearlman, A. L.

1970-01-01

1. The ability of cats to distinguish colours was investigated at mesopic and photopic levels to test the hypothesis that cats discriminate wavelength by using rods in conjunction with a single type of cone. 2. Cats were trained to distinguish red from cyan, and orange from cyan at the mesopic level. They retained the ability to make this discrimination when the coloured stimuli were placed against a background bright enough to saturate the rods. 3. One cat was also tested after being exposed to a bright white light of 9000 cd/m2 for a period of 5 min, and found able to distinguish red from cyan. 4. These results suggest that cats have more than one type of cone. Subsequent recordings from single units in the lateral geniculate nucleus showed that there are rare opponent colour units in layer B with input from a green-absorbing cone and a blue-absorbing cone. ImagesPlate 1 PMID:5500987

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.

Integrated Parallel Processes: The Elements of Meaning in Language. Volume IV.

DTIC Science & Technology

1981-11-01

times linguistics and psychology have sought them. Religion is deeply involved, and anthropology and sociology are in important ways relevant. The...quite cir’rly. No matter what heights the human mind can at- tain, it can work only with the organs it has and the functions peculiar to them. Eyes that...is speci- fied. If a neighborhood is specified with respect to outline, colour and texture, then all objects in a sufficiently small neighborhood will

The effect of warp tension on the colour of jacquard fabric made with different weaves structures

NASA Astrophysics Data System (ADS)

Karnoub, A.; Kadi, N.; Holmudd, O.; Peterson, J.; Skrifvars, M.

2017-10-01

The aims of this paper is to demonstrate the effect of warp tension on fabric colour for several types of weaves structures, and found a relationship between them. The image analyse technique used to determine the proportion of yarns colour appearance, the advantage of this techniques is the rapidity and reliability. The woven fabric samples are consisting of a polyester warp yarn with continuous filaments and density of 33 end/cm, a polypropylene weft yarn with a density of 24 pick/cm, and the warp tension ranged between 12-22 cN/tex. The experimental results demonstrated the effect of the warp tension on the colour of fabric, and this effect is related to several factors, where the large proportion of warp appearance leads to larger effect on fabric colour. The difference in the value of colour differences ΔEcmc is larger is in the range 16 to 20 cN/tex of warp tension. Using statistical methods, a mathematical model to calculate the amount of the colour difference ΔEcmc caused by the change in warp tension had been proposed.

Nutritional status of children under 5 years of age in Brazil: evidence of nutritional epidemiological polarisation.

PubMed

Pereira, Ingrid Freitas da Silva; Andrade, Lára de Melo Barbosa; Spyrides, Maria Helena Constatino; Lyra, Clélia de Oliveira

2017-10-01

The objective of this study was to evaluate the nutritional status of children under 5 years of age in Brazil in 2009 and its association with social and demographic factors. Data from the Household Budget Survey (Pesquisa de Orçamento Familiar - POF 2008-2009) were used, in which the nutritional profile was evaluated according to the weight-for-age (W/A), height-for-age (H/A) and weight-for-height (W/H) indices (n = 14,569). The association was estimated by applying the Pearson association test, a logistic regression and a correspondence analysis. The correspondence analysis showed a higher association of thinness with children in the North and Northeast regions, in families with lower levels of income and in those of black colour/race. Overweight and obesity had a stronger relationship with children living in the South, Southeast and Central-West, in males, in those from urban areas, in those of Caucasian colour/race, in those aged 3 years and in those from families with intermediate income ranges. Overweight and obesity showed a heterogeneous spatial distribution amongst Brazilian states. A nutritional epidemiological polarisation that presents a major challenge for public health is indicated: we must reduce nutritional deficiencies and promote healthy eating habits from childhood to improve the nutritional and epidemiological profiles and mortality of the population.

Solar radiation stress in climbing snails: behavioural and intrinsic features define the Hsp70 level in natural populations of Xeropicta derbentina (Pulmonata).

PubMed

Di Lellis, Maddalena A; Seifan, Merav; Troschinski, Sandra; Mazzia, Christophe; Capowiez, Yvan; Triebskorn, Rita; Köhler, Heinz-R

2012-11-01

Ectotherms from sunny and hot environments need to cope with solar radiation. Mediterranean land snails of the superfamily Helicoidea feature a behavioural strategy to escape from solar radiation-induced excessive soil heating by climbing up vertical objects. The height of climbing, and also other parameters like shell colouration pattern, shell orientation, shell size, body mass, actual internal and shell surface temperature, and the interactions between those factors may be expected to modulate proteotoxic effects in snails exposed to solar radiation and, thus, their stress response. Focussing on natural populations of Xeropicta derbentina, we conducted a 'snapshot' field study using the individual Hsp70 level as a proxy for proteotoxic stress. In addition to correlation analyses, an IT-model selection approach based on Akaike's Information Criterion was applied to evaluate a set of models with respect to their explanatory power and to assess the relevance of each of the above-mentioned parameters for individual stress, by model averaging and parameter estimation. The analysis revealed particular importance of the individuals' shell size, height above ground, the shell colouration pattern and the interaction height × orientation. Our study showed that a distinct set of behavioural traits and intrinsic characters define the Hsp70 level and that environmental factors and individual features strongly interact.

The shape of the face template: geometric distortions of faces and their detection in natural scenes.

PubMed

Pongakkasira, Kaewmart; Bindemann, Markus

2015-04-01

Human face detection might be driven by skin-coloured face-shaped templates. To explore this idea, this study compared the detection of faces for which the natural height-to-width ratios were preserved with distorted faces that were stretched vertically or horizontally. The impact of stretching on detection performance was not obvious when faces were equated to their unstretched counterparts in terms of their height or width dimension (Experiment 1). However, stretching impaired detection when the original and distorted faces were matched for their surface area (Experiment 2), and this was found with both vertically and horizontally stretched faces (Experiment 3). This effect was evident in accuracy, response times, and also observers' eye movements to faces. These findings demonstrate that height-to-width ratios are an important component of the cognitive template for face detection. The results also highlight important differences between face detection and face recognition. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of retinopathy on the achromatic and chromatic vision of patients with type 2 diabetes

PubMed Central

2014-01-01

Background Luminance contrast sensitivity and colour vision are considered to have great predictive value in the evaluation of type 2 diabetic retinopathy. However, these two visual characteristics have seldom been investigated in the same group of patients. In the present study we measured contrast sensitivity and colour vision in a group of patients with type 2 diabetes and correlated the results with estimates of common metabolic markers for the disease. A subgroup of the patients had no clinical signs of retinopathy. Methods The vision of 27 patients (n = 50 eyes) with type 2 diabetes, with retinopathy (n = 20 eyes), or without retinopathy (n = 30 eyes) were evaluated using two psychophysical tests, the Farnsworth–Munsell 100 hue test (FM 100), and measurements of the luminance contrast sensitivity at 11 spatial frequencies. The results were compared with measurements obtained from an age-matched control group (n = 32), and were correlated with the level of glycated haemoglobin, glycaemic level, and time of disease onset. Signs of retinopathy were identified during the ophthalmological examinations. Results Contrast sensitivity and colour vision impairments were present at different levels in diabetes patients. Eyes with retinopathy showed more severe vision loss than eyes without retinopathy. The FM 100 test was more sensitive for separation of patients from controls. Colour vision loss had no colour axes preference. The contrast sensitivity test appeared to have some advantage in differentiating patients with retinopathy from patients without retinopathy. Conclusions Both methods can be useful to follow the visual function of diabetic patients and should be used together to discriminate patients from controls, as well as to identify early signs of retinal damage. PMID:25174264

Lambmeat colour values (HunterLab CIE and reflectance) are influenced by aperture size (5 mm v. 25 mm).

PubMed

Holman, Benjamin W B; Ponnampalam, Eric N; van de Ven, Remy J; Kerr, Matthew G; Hopkins, David L

2015-02-01

The effect of aperture size on the assessment of lamb meat colour values (L*, a*, b* and R630/580)was investigated. Two experiments using 2 HunterLab MiniScan colorimeters (large [25 mm] and small [5 mm] apertures) were conducted: 1) coloured tiles were measured and 2) unaged lamb (n = 65) m. longissimus lumborum (LL) and m. semimembranosus (SM) muscles were measured over 2.5 d under simulated retail display. For Experiment three, 2 different colorimeters were used on lamb (n = 36) LL aged for 6 weeks before measurement over 4 don simulated retail display. Coloured tile a* and b* values were unaffected by aperture size, but L* values and the R630/580 ratio were influenced by aperture size. The effect of aperture size on lamb meat colour measurements varied with display time and muscle type. The large aperture size generally provided the highest colorimetric values, and is recommended for measuring lamb meat colour.

Colour coding scrubs as a means of improving perioperative communication.

PubMed

Litak, Dominika

2011-05-01

Effective communication within the operating department is essential for achieving patient safety. A large part of the perioperative communication is non-verbal. One type of non-verbal communication is 'object communication', the most common form of which is clothing. The colour coding of clothing such as scrubs has the potential to optimise perioperative communication with the patients and between the staff. A colour contains a coded message, and is a visual cue for an immediate identification of personnel. This is of key importance in the perioperative environment. The idea of colour coded scrubs in the perioperative setting has not been much explored to date and, given the potential contributiontowards improvement of patient outcomes, deserves consideration.

Prevalence of colour blindness among the first year medical & dental students of Mymensingh Medical College, Bangladesh.

PubMed

Hossain, M I; Nahar, L; Dad, M S; Islam, M F; Uddin, M M

2013-10-01

The purpose of this study was to detect the etiology, type and prevalence of colour blindness & to create awareness among the blind personnel. A survey of colour blindness among 239 ( male-87 & female-152) Medical and Dental first year students during their medical checkup before admission into Mymensingh Medical College in the session of 2012-2013 was done. Among them 8(male-7, female-1) were colour blind and prevalence was 3.35 % with a marked male predominance (male 8.04%, female 0.66 %). In view of the potential difficulties faced by such personnel in clinical works, detection during medical admission allowed appropriate counseling regarding subject selection for their future carrier.

A neuronal circuit for colour vision based on rod-cone opponency.

PubMed

Joesch, Maximilian; Meister, Markus

2016-04-14

In bright light, cone-photoreceptors are active and colour vision derives from a comparison of signals in cones with different visual pigments. This comparison begins in the retina, where certain retinal ganglion cells have 'colour-opponent' visual responses-excited by light of one colour and suppressed by another colour. In dim light, rod-photoreceptors are active, but colour vision is impossible because they all use the same visual pigment. Instead, the rod signals are thought to splice into retinal circuits at various points, in synergy with the cone signals. Here we report a new circuit for colour vision that challenges these expectations. A genetically identified type of mouse retinal ganglion cell called JAMB (J-RGC), was found to have colour-opponent responses, OFF to ultraviolet (UV) light and ON to green light. Although the mouse retina contains a green-sensitive cone, the ON response instead originates in rods. Rods and cones both contribute to the response over several decades of light intensity. Remarkably, the rod signal in this circuit is antagonistic to that from cones. For rodents, this UV-green channel may play a role in social communication, as suggested by spectral measurements from the environment. In the human retina, all of the components for this circuit exist as well, and its function can explain certain experiences of colour in dim lights, such as a 'blue shift' in twilight. The discovery of this genetically defined pathway will enable new targeted studies of colour processing in the brain.

Occupational colour vision requirements for police officers.

PubMed

Birch, Jennifer; Chisholm, Catharine M

2008-11-01

Inclusion of public service professions in the UK Disability Discrimination Act in 2004 prompted a review of occupational colour vision requirements for police officers. Changes in the regulations which existed prior to 2003 were proposed. The aim of this study was to obtain the views of serving police officers in Northern Ireland on the importance of good colour discrimination in everyday police work and on the recruitment regulations for patrol constables introduced in 2003 in mainland UK. These views were obtained by means of a questionnaire and informal discussions. More than 65% of police officers who responded to the questionnaire considered that good colour vision was very important for effective policing. Fewer than 2% considered that colour vision was unimportant. Experienced police officers agreed that the employment of colour-deficient patrol constables, as permitted in the new regulations, would lead to reduced efficiency and organisational difficulties at the local level. A number of everyday activities were described which showed the need for accurate colour discrimination. The change in recruitment policy and the lack of clarity in the new regulations show inadequate appreciation of the needs of the occupation, of different types of colour vision anomalies and of the diagnostic function of colour vision tests. Failure to provide guidance on appropriate colour vision tests, examination procedures and counselling services is likely to result in inconsistent employment policies in different police forces. It is recommended that the colour vision standard in place prior to 2003 is reinstated at the recruitment stage. The Ishihara test should be used for screening, and colour-deficient applicants further examined with the Farnsworth D15 test as a replacement for the City University Test 2nd edition.

On the biology of Tropidurus delanonis, Baur (Iguanidae).

PubMed

Werner, D I

1978-08-01

A field study of Tropidurus delanonis was carried out on an uninhabited island (Hood) of the Galapagos Archipelago over 18 months. The purpose of the study is to show the interrelation between social structure, behaviour and ecological aspects of the iguanid lizard Tropidurus delanonis. Five lizard categories are distinguished and the interrelation between colouration type and behaviour is shown. Data are given on population structure, composition and flexibility, reproductive cycle, clutch size, ontogeny and changes in colouration and behaviour. Detailed maps show the distribution of female and male territories and the area occupied by those male male that attempt to acquire a territory. The biomass is calculated for all categories in resect to total area available and to favorable and unfavorable areas within the observation area. The significance of various colouration types was tested experimentally.

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

PubMed

Werner, Annette

2014-11-01

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

The ATLAS3D project - XXVII. Cold gas and the colours and ages of early-type galaxies

NASA Astrophysics Data System (ADS)

Young, Lisa M.; Scott, Nicholas; Serra, Paolo; Alatalo, Katherine; Bayet, Estelle; Blitz, Leo; Bois, Maxime; Bournaud, Frédéric; Bureau, Martin; Crocker, Alison F.; Cappellari, Michele; Davies, Roger L.; Davis, Timothy A.; de Zeeuw, P. T.; Duc, Pierre-Alain; Emsellem, Eric; Khochfar, Sadegh; Krajnović, Davor; Kuntschner, Harald; McDermid, Richard M.; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Weijmans, Anne-Marie

2014-11-01

We present a study of the cold gas contents of the ATLAS3D early-type galaxies, in the context of their optical colours, near-ultraviolet colours and Hβ absorption line strengths. Early-type (elliptical and lenticular) galaxies are not as gas poor as previously thought, and at least 40 per cent of local early-type galaxies are now known to contain molecular and/or atomic gas. This cold gas offers the opportunity to study recent galaxy evolution through the processes of cold gas acquisition, consumption (star formation) and removal. Molecular and atomic gas detection rates range from 10 to 34 per cent in red sequence early-type galaxies, depending on how the red sequence is defined, and from 50 to 70 per cent in blue early-type galaxies. Notably, massive red sequence early-type galaxies (stellar masses >5 × 1010 M⊙, derived from dynamical models) are found to have H I masses up to M(H I)/M* ˜ 0.06 and H2 masses up to M(H2)/M* ˜ 0.01. Some 20 per cent of all massive early-type galaxies may have retained atomic and/or molecular gas through their transition to the red sequence. However, kinematic and metallicity signatures of external gas accretion (either from satellite galaxies or the intergalactic medium) are also common, particularly at stellar masses ≤5 × 1010 M⊙, where such signatures are found in ˜50 per cent of H2-rich early-type galaxies. Our data are thus consistent with a scenario in which fast rotator early-type galaxies are quenched former spiral galaxies which have undergone some bulge growth processes, and in addition, some of them also experience cold gas accretion which can initiate a period of modest star formation activity. We discuss implications for the interpretation of colour-magnitude diagrams.

Wine bottle colour and oxidative spoilage: whole bottle light exposure experiments under controlled and uncontrolled temperature conditions.

PubMed

Dias, Daniel A; Clark, Andrew C; Smith, Trevor A; Ghiggino, Kenneth P; Scollary, Geoffrey R

2013-06-15

Exposure of a Chardonnay wine to light from a mercury vapour lamp under controlled temperature conditions showed that colour enhancement was dependent on bottle colour. The increase in colouration was Antique Green

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.

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.

Beyond the subjective experience of colour: An experimental case study of grapheme-texture synesthesia.

PubMed

Banno, Hayaki; Koga, Hiroki; Yamamoto, Hiroki; Saiki, Jun

2017-07-01

This study was a case investigation of grapheme-texture synestheste TH, a female who subjectively reported experiencing a visual association between grapheme and colour/texture. First, we validated the existence of a synesthetic association in an objective manner. Involuntarily elicited experience is a major hallmark that is common to different types of synesthetes. Our results indicated interference between physical and synesthetic texture, suggesting the involuntary occurrence of synesthetic textural experience. We analysed the behavioural measures using the EZ diffusion model. The result suggested that TH's synesthetic experience was dissociable from that of briefly trained associative processing of non-synesthetes. Second, we investigated how the synesthetic experience of colour and texture dimensions was bound in the visual representation. We found that the interference effects of colour and texture were not independent. This suggested that in the elicited experience, the colour and texture features construct an integrated representation.

Predicting stellar angular diameters from V, IC, H and K photometry

NASA Astrophysics Data System (ADS)

Adams, Arthur D.; Boyajian, Tabetha S.; von Braun, Kaspar

2018-01-01

Determining the physical properties of microlensing events depends on having accurate angular sizes of the source star. Using long baseline optical interferometry, we are able to measure the angular sizes of nearby stars with uncertainties ≤2 per cent. We present empirically derived relations of angular diameters which are calibrated using both a sample of dwarfs/subgiants and a sample of giant stars. These relations are functions of five colour indices in the visible and near-infrared, and have uncertainties of 1.8-6.5 per cent depending on the colour used. We find that a combined sample of both main-sequence and evolved stars of A-K spectral types is well fitted by a single relation for each colour considered. We find that in the colours considered, metallicity does not play a statistically significant role in predicting stellar size, leading to a means of predicting observed sizes of stars from colour alone.

Interactions between colour-producing mechanisms and their effects on the integumentary colour palette.

PubMed

Shawkey, Matthew D; D'Alba, Liliana

2017-07-05

Animal integumentary coloration plays a crucial role in visual communication and camouflage, and varies extensively among and within species and populations. To understand the pressures underlying such diversity, it is essential to elucidate the mechanisms by which animals have created novel integumentary coloration. Colours can be produced by selective absorption of light by skin pigments, through light scattering by structured or unstructured tissues, or by a combination of pigments and nanostructures. In this review, we highlight our current understanding of the interactions between pigments and structural integumentary tissues and molecules. We analyse the available evidence suggesting that these combined mechanisms are capable of creating colours and optical properties unachievable by either mechanism alone, thereby effectively expanding the animal colour palette. Moreover, structural and pigmentary colour mechanisms frequently interact in unexpected and overlooked ways, suggesting that classification of colours as being of any particular type may be difficult. Finally, we discuss how these mixtures are useful for investigating the largely unknown genetic, developmental and physical processes generating phenotypic diversity.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

Mapping the timecourse of goal-directed attention to location and colour in human vision.

PubMed

Adams, Rachel C; Chambers, Christopher D

2012-03-01

Goal-directed attention prioritises perception of task-relevant stimuli according to location, features, or onset time. In this study we compared the behavioural timecourse of goal-directed selection to locations and colours by varying the stimulus-onset asynchrony (SOA) between cue and target in a strategic cueing paradigm. Participants reported the presence or absence of a target following prior information regarding its location or colour. Results revealed that preparatory selection by colour is more effective at enhancing perceptual sensitivity than selection by location, even though both types of cue provided equivalent overall information. More detailed analysis revealed that this advantage arose due a limitation of spatial attention in maintaining a sufficiently broad focus (>2°) for target detection across multiple stimuli. In contrast, when target stimuli fell within 2° of the spatial attention spotlight, the strategic advantages and speed of spatial and colour attention were equated. Our findings are consistent with the conclusion that, under spatially optimal conditions, prior spatial and colour information are equally proficient at guiding top-down selection. When spatial locations are ambiguous, however, colour-based selection is the more efficient mechanism. Copyright © 2012 Elsevier B.V. All rights reserved.

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

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…

Colour of fat, and colour, fatty acid composition and sensory characteristics of muscle from heifers offered alternative forages to grass silage in a finishing ration.

PubMed

Moloney, A P; Mooney, M T; Kerry, J P; Stanton, C; O'Kiely, P

2013-11-01

The effect of type of silage offered to beef heifers during the finishing period on aspects of beef quality was determined. In two experiments, a diet based on grass silage (GS) was compared with a diet based on maize silage (MS) or whole-crop wheat silage (WCW). Compared to the GS-based diet, increasing the amount of MS linearly increased fat whiteness while the increase in fat whiteness due to WCW was dependent on the stage of crop maturity at harvesting. There was no effect of diet on muscle colour or on muscle pH measured at 48h post-mortem, drip loss, taste panel traits after 14days ageing or shear force values at 2, 7 or 14days ageing. The alternative silages decreased the n-3 polyunsaturated fatty acid proportion and increased the linoleic:linolenic acid ratio in intramuscular lipid. It is concluded that type of silage affects fat colour and fatty acid composition of muscle but not the other muscle characteristics examined. Copyright © 2013 Elsevier Ltd. All rights reserved.

The VIMOS Public Extragalactic Redshift Survey (VIPERS). The coevolution of galaxy morphology and colour to z 1

NASA Astrophysics Data System (ADS)

Krywult, J.; Tasca, L. A. M.; Pollo, A.; Vergani, D.; Bolzonella, M.; Davidzon, I.; Iovino, A.; Gargiulo, A.; Haines, C. P.; Scodeggio, M.; Guzzo, L.; Zamorani, G.; Garilli, B.; Granett, B. R.; de la Torre, S.; Abbas, U.; Adami, C.; Bottini, D.; Cappi, A.; Cucciati, O.; Franzetti, P.; Fritz, A.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; Marulli, F.; Polletta, M.; Tojeiro, R.; Zanichelli, A.; Arnouts, S.; Bel, J.; Branchini, E.; Coupon, J.; De Lucia, G.; Ilbert, O.; McCracken, H. J.; Moscardini, L.; Takeuchi, T. T.

2017-02-01

Context. The study of the separation of galaxy types into different classes that share the same characteristics, and of the evolution of the specific parameters used in the classification are fundamental for understanding galaxy evolution. Aims: We explore the evolution of the statistical distribution of galaxy morphological properties and colours combining high-quality imaging data from the CFHT Legacy Survey with the large number of redshifts and extended photometry from the VIPERS survey. Methods: Galaxy structural parameters were combined with absolute magnitudes, colours and redshifts in order to trace evolution in a multi-parameter space. Using a new method we analysed the combination of colours and structural parameters of early- and late-type galaxies in luminosity-redshift space. Results: We find that both the rest-frame colour distributions in the (U-B) vs. (B-V) plane and the Sérsic index distributions are well fitted by a sum of two Gaussians, with a remarkable consistency of red-spheroidal and blue-disky galaxy populations, over the explored redshift (0.5 < z < 1) and luminosity (-1.5 < B-B∗ < 1.0) ranges. The combination of the rest-frame colour and Sérsic index as a function of redshift and luminosity allows us to present the structure of both galaxy types and their evolution. We find that early-type galaxies display only a slow change in their concentrations after z = 1. Their high concentrations were already established at z 1 and depend much more strongly on their luminosity than redshift. In contrast, late-type galaxies clearly become more concentrated with cosmic time with only little evolution in colour, which remains dependent mainly on their luminosity. Conclusions: The combination of rest-frame colours and Sérsic index as a function of redshift and luminosity leads to a precise statistical description of the structure of galaxies and their evolution. Additionally, the proposed method provides a robust way to split galaxies into early and late types. Based on observations collected at the European Southern Observatory, Cerro Paranal, Chile, using the Very Large Telescope under programs 182.A-0886 and partly 070.A-9007. Also based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. The VIPERS web site is http://vipers.inaf.it/A table of the fitted parameters is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/598/A120

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.

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.

Colour discrimination ellipses in choroideremia.

PubMed

Seitz, Immanuel P; Jolly, Jasleen K; Dominik Fischer, M; Simunovic, Matthew P

2018-04-01

The purpose of this study was to characterise alterations in colour discrimination in a cohort of patients with choroideremia prior to gene therapy, using a test previously validated for use in patients with retinal dystrophies. We tested 20 eyes of 10 patients with a diagnosis of choroideremia and an age-matched cohort of 10 eyes of 10 normal controls using the "Cambridge Colour Test" (CCT), in which subjects are required to distinguish the gap in a C presented in one of 4 orientations in a Stilling-type array. Colour discrimination was probed along eight axes in the CIE L*u*v* colour space, and the resulting data were plotted in the CIE 1976 chromaticity diagram and fitted with least-squares ellipses. Subsequently, we estimated the achromatic area for each subject by calculating the area of the resultant discrimination ellipse and calculated sensitivity thresholds along relevant colour confusion axes. Colour discrimination-as quantified by log 10 of the ellipse area expressed in square 1/1000th 2 units in CIE 1976-was 2.26 (range 1.82 to 2.67) for normal subjects and 3.85 (range 2.35 to 5.41) for choroideremia patients. There was a statistically significant correlation between both achromatic area and red-green colour discrimination at the CCT and BCVA, and to a lesser degree between blue colour discrimination at the CCT and BCVA. The majority of ellipses in choroideremia were aligned close to the tritan axis, and loss of sensitivity was significantly larger in the tritan direction than in the red-green. The majority of our patients demonstrated greater loss in tritan discrimination than in red-green colour discrimination using the CCT. There was a significant correlation between achromatic area and BCVA. In keeping with our current understanding of the machinery of colour vision, there was a significant correlation between BCVA and colour discrimination thresholds, which was stronger for red-green colour discrimination, than for tritan colour discrimination. We propose that this and similar tests of colour discrimination may prove to be suitable tools for assessing functional outcomes in gene therapy trials for choroideremia.

The evolution of early-type galaxies in nearby clusters: breaking the age-metallicity degeneracy with Spitzer IRS Blue Peak-Up Imaging

NASA Astrophysics Data System (ADS)

Bressan, Alessandro; Buson, Lucio; Clemens, Marcel; Danese, Luigi; Granato, Gian Luigi; Panuzzo, Pasquale; Rampazzo, Roberto; Silva, Laura; Valdes, Jose Ramon

2005-06-01

We have shown with Cycle 1 observations that Spitzer has the capability of disentangling age and metallicity in old stellar populations. By looking to the broad emission feature left by dust enshrouded asymptotic giant branch stars above 9.7 microns, Spitzer IRS can provide direct evidence that the colour- magnitude relation of Virgo ellipticals is mainly driven by metallicity. However, with the IRS spectrograph we can only probe the bright tail of the colour-magnitude relation, and only in the nearest cluster. We propose to use IRS Blue Peak-Up, the only Spitzer band that looks directly in the core of that spectral feature, to reach fainter galaxies. We will perform a thorough investigation of early type galaxies along the colour-magnitude relation in Virgo and in Coma clusters. These observations, when coupled with already existing IRAC and Optical-NIR observations, will allow a) an unbiased census of the stellar populations in cluster early type galaxies; b) an estimate of the AGB material recycled into the ISM in these systems; c) a direct check of the universality of the colour- magnitude relation on a wide range of magnitudes; d) a spatial study of the stellar populations within the galaxies, e.g. investigating differences between bulge and disk populations within S0; e) the most secure reference frame with which to compare the evolution of early type galaxies in other environments (groups and field).

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.

Texture Profile and Color Determination on Local and Imported Meat Available in Semarang City, Indonesia

NASA Astrophysics Data System (ADS)

Arifin, Mukh; Ni'matullah Al-Baarri, Ahmad; Etza Setiani, Bhakti; Fazriyati Siregar, Risa

2018-02-01

This study was done for analysing the texture profile and colour performance in local and imported meat in Semarang, Indonesia. Two types of available meat were compared in the hardness, cohesiveness, springiness, adhesiveness and the colour L*a*b* performance. Five fresh beef cut of round meats from local and imported meat were used in this experiments. Data were analysed statistically using T-test. The results showed that local beef exhibit higher in the springiness than imported beef resulting in the remarkable differences. The colour analysis showed that imported beef provided remarkable higher in L* value than local beef. Resulting significant differences among two types of beef. As conclusion, these value might provide the notable of differences among local and imported meat and may give preferences status to the user for further application in meat processing.

Coherent modulation of stimulus colour can affect visually induced self-motion perception.

PubMed

Nakamura, Shinji; Seno, Takeharu; Ito, Hiroyuki; Sunaga, Shoji

2010-01-01

The effects of dynamic colour modulation on vection were investigated to examine whether perceived variation of illumination affects self-motion perception. Participants observed expanding optic flow which simulated their forward self-motion. Onset latency, accumulated duration, and estimated magnitude of the self-motion were measured as indices of vection strength. Colour of the dots in the visual stimulus was modulated between white and red (experiment 1), white and grey (experiment 2), and grey and red (experiment 3). The results indicated that coherent colour oscillation in the visual stimulus significantly suppressed the strength of vection, whereas incoherent or static colour modulation did not affect vection. There was no effect of the types of the colour modulation; both achromatic and chromatic modulations turned out to be effective in inhibiting self-motion perception. Moreover, in a situation where the simulated direction of a spotlight was manipulated dynamically, vection strength was also suppressed (experiment 4). These results suggest that observer's perception of illumination is critical for self-motion perception, and rapid variation of perceived illumination would impair the reliabilities of visual information in determining self-motion.

How hollow melanosomes affect iridescent colour production in birds

PubMed Central

Eliason, Chad M.; Bitton, Pierre-Paul; Shawkey, Matthew D.

2013-01-01

Developmental constraints and trade-offs can limit diversity, but organisms have repeatedly evolved morphological innovations that overcome these limits by expanding the range and functionality of traits. Iridescent colours in birds are commonly produced by melanin-containing organelles (melanosomes) organized into nanostructured arrays within feather barbules. Variation in array type (e.g. multilayers and photonic crystals, PCs) is known to have remarkable effects on plumage colour, but the optical consequences of variation in melanosome shape remain poorly understood. Here, we used a combination of spectrophotometric, experimental and theoretical methods to test how melanosome hollowness—a morphological innovation largely restricted to birds—affects feather colour. Optical analyses of hexagonal close-packed arrays of hollow melanosomes in two species, wild turkeys (Meleagris gallopavo) and violet-backed starlings (Cinnyricinclus leucogaster), indicated that they function as two-dimensional PCs. Incorporation of a larger dataset and optical modelling showed that, compared with solid melanosomes, hollow melanosomes allow birds to produce distinct colours with the same energetically favourable, close-packed configurations. These data suggest that a morphological novelty has, at least in part, allowed birds to achieve their vast morphological and colour diversity. PMID:23902909

Global Interior Robot Localisation by a Colour Content Image Retrieval System

NASA Astrophysics Data System (ADS)

Chaari, A.; Lelandais, S.; Montagne, C.; Ahmed, M. Ben

2007-12-01

We propose a new global localisation approach to determine a coarse position of a mobile robot in structured indoor space using colour-based image retrieval techniques. We use an original method of colour quantisation based on the baker's transformation to extract a two-dimensional colour pallet combining as well space and vicinity-related information as colourimetric aspect of the original image. We conceive several retrieving approaches bringing to a specific similarity measure [InlineEquation not available: see fulltext.] integrating the space organisation of colours in the pallet. The baker's transformation provides a quantisation of the image into a space where colours that are nearby in the original space are also nearby in the output space, thereby providing dimensionality reduction and invariance to minor changes in the image. Whereas the distance [InlineEquation not available: see fulltext.] provides for partial invariance to translation, sight point small changes, and scale factor. In addition to this study, we developed a hierarchical search module based on the logic classification of images following rooms. This hierarchical module reduces the searching indoor space and ensures an improvement of our system performances. Results are then compared with those brought by colour histograms provided with several similarity measures. In this paper, we focus on colour-based features to describe indoor images. A finalised system must obviously integrate other type of signature like shape and texture.

Influence of Texture and Colour in Breast TMA Classification

PubMed Central

Fernández-Carrobles, M. Milagro; Bueno, Gloria; Déniz, Oscar; Salido, Jesús; García-Rojo, Marcial; González-López, Lucía

2015-01-01

Breast cancer diagnosis is still done by observation of biopsies under the microscope. The development of automated methods for breast TMA classification would reduce diagnostic time. This paper is a step towards the solution for this problem and shows a complete study of breast TMA classification based on colour models and texture descriptors. The TMA images were divided into four classes: i) benign stromal tissue with cellularity, ii) adipose tissue, iii) benign and benign anomalous structures, and iv) ductal and lobular carcinomas. A relevant set of features was obtained on eight different colour models from first and second order Haralick statistical descriptors obtained from the intensity image, Fourier, Wavelets, Multiresolution Gabor, M-LBP and textons descriptors. Furthermore, four types of classification experiments were performed using six different classifiers: (1) classification per colour model individually, (2) classification by combination of colour models, (3) classification by combination of colour models and descriptors, and (4) classification by combination of colour models and descriptors with a previous feature set reduction. The best result shows an average of 99.05% accuracy and 98.34% positive predictive value. These results have been obtained by means of a bagging tree classifier with combination of six colour models and the use of 1719 non-correlated (correlation threshold of 97%) textural features based on Statistical, M-LBP, Gabor and Spatial textons descriptors. PMID:26513238

Reliability of tristimulus colourimetry in the assessment of cutaneous bruise colour.

PubMed

Scafide, Katherine N; Sheridan, Daniel J; Taylor, Laura A; Hayat, Matthew J

2016-06-01

Bruising is one of the most common types of injury clinicians observe among victims of violence and other trauma patients. However, research has shown commonly used qualitative description of cutaneous bruise colour via the naked eye is subjective and unreliable. No published work has formally evaluated the reliability of tristimulus colourimetry as an alternative for assessing bruise colour, despite its clinical and research applications in accurately assessing skin colour. The purpose of this study was to systematically evaluate the test-retest and inter-observer reliability of tristimulus colourimetry in the assessment of cutaneous bruise colour. Two researchers obtained repeated tristimulus colourimetry measures of cutaneous bruises with participants of diverse skin colour. Measures were obtained using the Minolta CR-400 Chomameter. Commission Internationale d'Eclairage (CIE) L*a*b* colour space was used. Data was analysed using intraclass correlation coefficients (ICC), Cronbach's alpha, and minimal detectable change (MDC) on all three L*a*b* values. The colorimeter demonstrated excellent test-retest or intra-rater reliability (L* ICC=0.999; a* ICC=0.973; b* ICC=0.892) and inter-rater reliability (L* ICC=0.997; a* ICC=0.976; b* ICC=0.982). With consistent placement, the tristimulus colourimetry is reliable for the objective assessment and documentation of cutaneous bruise colour for purposes of clinical practice and research. Recommendations for use in practice/research are provided. Copyright © 2016 Elsevier Ltd. All rights reserved.

A transparent look at the measurement and application of colour rendering in the use of LED light sources

NASA Astrophysics Data System (ADS)

Leuschner, F. W.; Van Der Westhuyzen, J. G. J.

2014-06-01

The technology for the measurement of colour rendering and colour quality is not new, but many parameters related to this issue are currently changing. A number of standard methods were developed and are used by different specialty areas of the lighting industry. CIE 13.3 has been the accepted standard implemented by many users and used for many years. Light-emitting Diode (LED) technology moves at a rapid pace and, as this lighting source finds wider acceptance, it appears that traditional colour-rendering measurement methods produce inconsistent results. Practical application of various types of LEDs yielded results that challenged conventional thinking regarding colour measurement of light sources. Recent studies have shown that the anatomy and physiology of the human eye is more complex than formerly accepted. Therefore, the development of updated measurement methodology also forces a fresh look at functioning and colour perception of the human eye, especially with regard to LEDs. This paper includes a short description of the history and need for the measurement of colour rendering. Some of the traditional measurement methods are presented and inadequacies are discussed. The latest discoveries regarding the functioning of the human eye and the perception of colour, especially when LEDs are used as light sources, are discussed. The unique properties of LEDs when used in practical applications such as luminaires are highlighted.

The genetics of colour in fat-tailed sheep: a review.

PubMed

Lundie, Roger S

2011-10-01

Fat-tailed sheep come in various colours-most are either brown (tan) or black. In some, most of the body is white with the tan or black colour restricted to the front portion of the body or to just around the eyes, muzzle and parts of the legs. The Karakul breed is important for the production of lamb skins of various colours for the fashion industry. As well as the black and tan colours there are Karakuls bred for grey or roan shades, a white colour or one of the numerous Sur shades. In the Sur shades, the base of the birthcoat fibre is one of a number of dark shades and the tip a lighter or white shade. All these colours and many others are the result of the interaction of various genes that determine the specifics of the coat colour of the sheep. A number of sets of nomenclature and symbols have been used to represent the various loci and their alleles that are involved. In the 1980s and 1990s, a standardised set, based closely on those of the mouse and other species was developed. Using this as the framework, the alleles of the Extension, Agouti, Brown, Spotting, Pigmented Head and Roan loci are described using fat-tailed sheep (mainly Damara, Karakul and Persian) as examples. Further discussion includes other types of "white markings," the Ticking locus and the Sur loci.

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.

A mutation in the MATP gene causes the cream coat colour in the horse

PubMed Central

Mariat, Denis; Taourit, Sead; Guérin, Gérard

2003-01-01

In horses, basic colours such as bay or chestnut may be partially diluted to buckskin and palomino, or extremely diluted to cream, a nearly white colour with pink skin and blue eyes. This dilution is expected to be controlled by one gene and we used both candidate gene and positional cloning strategies to identify the "cream mutation". A horse panel including reference colours was established and typed for different markers within or in the neighbourhood of two candidate genes. Our data suggest that the causal mutation, a G to A transition, is localised in exon 2 of the MATP gene leading to an aspartic acid to asparagine substitution in the encoded protein. This conserved mutation was also described in mice and humans, but not in medaka. PMID:12605854

Synaesthesia: when coloured sounds taste sweet.

PubMed

Beeli, Gian; Esslen, Michaela; Jäncke, Lutz

2005-03-03

Synaesthesia is the involuntary physical experience of a cross-modal linkage--for example, hearing a tone (the inducing stimulus) evokes an additional sensation of seeing a colour (concurrent perception). Of the different types of synaesthesia, most have colour as the concurrent perception, with concurrent perceptions of smell or taste being rare. Here we describe the case of a musician who experiences different tastes in response to hearing different musical tone intervals, and who makes use of her synaesthetic sensations in the complex task of tone-interval identification. To our knowledge, this combination of inducing stimulus and concurrent perception has not been described before.

Dichromatic Colour Vision in Wallabies as Characterised by Three Behavioural Paradigms

PubMed Central

Ebeling, Wiebke; Hemmi, Jan M.

2014-01-01

Despite lacking genetic evidence of a third cone opsin in the retina of any Australian marsupial, most species tested so far appear to be trichromatic. In the light of this, we have re-examined colour vision of the tammar wallaby which had previously been identified as a dichromat. Three different psychophysical tests, based on an operant conditioning paradigm, were used to confirm that colour perception in the wallaby can be predicted and conclusively explained by the existence of only two cone types. Firstly, colour-mixing experiments revealed a Confusion Point between the three primary colours of a LCD monitor that can be predicted by the cone excitation ratio of the short- and middle-wavelength sensitive cones. Secondly, the wavelength discrimination ability in the wallaby, when tested with monochromatic stimuli, was found to be limited to a narrow range between 440 nm and 500 nm. Lastly, an experiment designed to test the wallaby’s ability to discriminate monochromatic lights from a white light provided clear evidence for a Neutral Point around 485 nm where discrimination consistently failed. Relative colour discrimination seemed clearly preferred but it was possible to train a wallaby to perform absolute colour discriminations. The results confirm the tammar wallaby as a dichromat, and so far the only behaviourally confirmed dichromat among the Australian marsupials. PMID:24489742

Tsukamoto fuzzy implementation to identify the pond water quality of koi

NASA Astrophysics Data System (ADS)

Qur'ania, A.; Verananda, D. I.

2017-01-01

The colour quality of koi was affected by the water quality in the pond. Koi fish have a diversity of types differentiated based on the body colour groups, such as one colour pattern, two colour patterns, three colours patterns and even more. Each colour characteristic of the koi have different handling, particularly in the handling of water quality, this is because the colour pigments in the body was affected by the composition of water quality include temperature, pH, TDS, do and salinity. The data of koi fish used were sanke, sowa, kohaku, shiro, yamabuki, ogon and chagoi. The aim of this study is to make an application to inform the condition of the pool water quality that can help breeders to know the water quality that will improve the handling strategies through water media. Tsukamoto Fuzzy method used to produce the three outputs namely water quality, water grade, and water conditions. The output of water quality consists of four categories, namely optimal, moderate, poor, and very poor. The output of water grade consists of grade A to D, while the output of water conditions consist of an excellent, good, bad, and very bad. Input to the application consists of five parameters, namely water temperature, pH, TDS, do and salinity.

Dichromatic colour vision in wallabies as characterised by three behavioural paradigms.

PubMed

Ebeling, Wiebke; Hemmi, Jan M

2014-01-01

Despite lacking genetic evidence of a third cone opsin in the retina of any Australian marsupial, most species tested so far appear to be trichromatic. In the light of this, we have re-examined colour vision of the tammar wallaby which had previously been identified as a dichromat. Three different psychophysical tests, based on an operant conditioning paradigm, were used to confirm that colour perception in the wallaby can be predicted and conclusively explained by the existence of only two cone types. Firstly, colour-mixing experiments revealed a Confusion Point between the three primary colours of a LCD monitor that can be predicted by the cone excitation ratio of the short- and middle-wavelength sensitive cones. Secondly, the wavelength discrimination ability in the wallaby, when tested with monochromatic stimuli, was found to be limited to a narrow range between 440 nm and 500 nm. Lastly, an experiment designed to test the wallaby's ability to discriminate monochromatic lights from a white light provided clear evidence for a Neutral Point around 485 nm where discrimination consistently failed. Relative colour discrimination seemed clearly preferred but it was possible to train a wallaby to perform absolute colour discriminations. The results confirm the tammar wallaby as a dichromat, and so far the only behaviourally confirmed dichromat among the Australian marsupials.

UV Light Reveals the Diversity of Jurassic Shell Colour Patterns: Examples from the Cordebugle Lagerstätte (Calvados, France)

PubMed Central

Caze, Bruno; Merle, Didier; Schneider, Simon

2015-01-01

Viewed under UV light the diverse and exceptionally well-preserved molluscs from the Late Jurassic Cordebugle Konservat Lagerstätte (Calvados, Normandy, France) reveal fluorescent fossil shell colour patterns predating the oldest previously known instance of such patterns by 100 Myr. Evidently, residual colour patterns are observable in Mesozoic molluscs by application of this non-destructive method, provided the shells are not decalcified or recrystallized. Among 46 species which are assigned to twelve gastropod families and eight bivalve families, no less than 25 species yielded positive results. Out of nine colour pattern morphologies that have been distinguished six occur in gastropods and three in bivalves. The presence of these variant morphologies clearly indicates a significant pre-Cenozoic diversification of colour patterns, especially in gastropods. In addition, the occurrence of two distinct types of fluorescence highlights a major difference in the chemical composition of the pigments involved in colour pattern formation in gastropods. This discovery enables us to discriminate members of higher clades, i.e. the Vetigastropoda emitting red fluorescence from the Caenogastropoda and Heterobranchia emitting whitish-beige to yellow fluorescence. Consequently, fluorescent colour patterns may help to allocate part of the numerous enigmatic Mesozoic gastropod taxa to their correct systematic position. PMID:26039592

Wafer bonding process for building MEMS devices

NASA Astrophysics Data System (ADS)

Pabo, Eric F.; Meiler, Josef; Matthias, Thorsten

2014-06-01

The technology for the measurement of colour rendering and colour quality is not new, but many parameters related to this issue are currently changing. A number of standard methods were developed and are used by different specialty areas of the lighting industry. CIE 13.3 has been the accepted standard implemented by many users and used for many years. Light-emitting Diode (LED) technology moves at a rapid pace and, as this lighting source finds wider acceptance, it appears that traditional colour-rendering measurement methods produce inconsistent results. Practical application of various types of LEDs yielded results that challenged conventional thinking regarding colour measurement of light sources. Recent studies have shown that the anatomy and physiology of the human eye is more complex than formerly accepted. Therefore, the development of updated measurement methodology also forces a fresh look at functioning and colour perception of the human eye, especially with regard to LEDs. This paper includes a short description of the history and need for the measurement of colour rendering. Some of the traditional measurement methods are presented and inadequacies are discussed. The latest discoveries regarding the functioning of the human eye and the perception of colour, especially when LEDs are used as light sources, are discussed. The unique properties of LEDs when used in practical applications such as luminaires are highlighted.

Skin colour typology and suntanning pathways.

PubMed

Chardon, A; Cretois, I; Hourseau, C

1991-08-01

Synopsis The evaluation of sun-product efficacy, with laboratory solar simulators or in actual sun, implicates clinical and subjective assessment of the various skin responses in terms of wavelengths constitutive of solar light. These photobiological responses vary according to skin types and particularly to basic skin melanic content, i.e. with skin colour. Now, the instrumental measurement of live skin colour has become easier to perform, fast and reliable. Based on the standard CIE-L*a*b* colour system and correlated with the human eye, this technique was used to define the skin colour domain of the caucasian population, to propose a skin colour classification, and then to objectively follow, over a three week period, the dynamics and kinetics of tanning induced by UVB, UVA and UVB +/- A multi-exposures on the three skin categories. The specific directions in the three-dimensional L*a*b* colour space of the tanning components, i.e. erythema, immediate pigmentation and constitutional melanization, as well as the resulting tanning pathways, were analysed and defined in the three-dimensional colour space, using a vectorial method. The UVB, UVA and UVB +/- A tannings were differentiated by their intensity, their hue and especially their lasting capacity: UVA tanning clearly appeared more lasting than UVB. In addition, the UVA*UVB interaction on tanning intensity was not found to be significant. With the skin colour classification and the tanning models, this comprehensive study supplies a basic tool for the colorimetric interpretation of the skin phenomena involved, provided that this interpretation is always considered in the three dimensions of the colour space. It also suggests some useful practical applications for sun product formulation and evaluation.

Galaxy and Mass Assembly (GAMA): variation in galaxy structure across the green valley

NASA Astrophysics Data System (ADS)

Kelvin, Lee S.; Bremer, Malcolm N.; Phillipps, Steven; James, Philip A.; Davies, Luke J. M.; De Propris, Roberto; Moffett, Amanda J.; Percival, Susan M.; Baldry, Ivan K.; Collins, Chris A.; Alpaslan, Mehmet; Bland-Hawthorn, Joss; Brough, Sarah; Cluver, Michelle; Driver, Simon P.; Hashemizadeh, Abdolhosein; Holwerda, Benne W.; Laine, Jarkko; Lara-Lopez, Maritza A.; Liske, Jochen; Maciejewski, Witold; Napolitano, Nicola R.; Penny, Samantha J.; Popescu, Cristina C.; Sansom, Anne E.; Sutherland, Will; Taylor, Edward N.; van Kampen, Eelco; Wang, Lingyu

2018-07-01

Using a sample of 472 local Universe (z < 0.06) galaxies in the stellar mass range 10.25 {<} log {M}_{\\star }/{M}_{⊙} {<} 10.75, we explore the variation in galaxy structure as a function of morphology and galaxy colour. Our sample of galaxies is subdivided into red, green, and blue colour groups and into elliptical and non-elliptical (disk-type) morphologies. Using Kilo-Degree Survey (KiDS) and Visible and Infrared Survey Telescope for Astronomy (VISTA) Kilo-Degree Infrared Galaxy Survey (VIKING) derived postage stamp images, a group of eight volunteers visually classified bars, rings, morphological lenses, tidal streams, shells, and signs of merger activity for all systems. We find a significant surplus of rings (2.3σ) and lenses (2.9σ) in disk-type galaxies as they transition across the green valley. Combined, this implies a joint ring/lens green valley surplus significance of 3.3σ relative to equivalent disk-types within either the blue cloud or the red sequence. We recover a bar fraction of {˜ }44 per cent which remains flat with colour, however, we find that the presence of a bar acts to modulate the incidence of rings and (to a lesser extent) lenses, with rings in barred disk-type galaxies more common by ˜20-30 percentage points relative to their unbarred counterparts, regardless of colour. Additionally, green valley disk-type galaxies with a bar exhibit a significant 3.0σ surplus of lenses relative to their blue/red analogues. The existence of such structures rules out violent transformative events as the primary end-of-life evolutionary mechanism, with a more passive scenario the favoured candidate for the majority of galaxies rapidly transitioning across the green valley.

Galaxy and Mass Assembly (GAMA): Variation in Galaxy Structure Across the Green Valley

NASA Astrophysics Data System (ADS)

Kelvin, Lee S.; Bremer, Malcolm N.; Phillipps, Steven; James, Philip A.; Davies, Luke J. M.; De Propris, Roberto; Moffett, Amanda J.; Percival, Susan M.; Baldry, Ivan K.; Collins, Chris A.; Alpaslan, Mehmet; Bland-Hawthorn, Joss; Brough, Sarah; Cluver, Michelle; Driver, Simon P.; Hashemizadeh, Abdolhosein; Holwerda, Benne W.; Laine, Jarkko; Lara-Lopez, Maritza A.; Liske, Jochen; Maciejewski, Witold; Napolitano, Nicola R.; Penny, Samantha J.; Popescu, Cristina C.; Sansom, Anne E.; Sutherland, Will; Taylor, Edward N.; van Kampen, Eelco; Wang, Lingyu

2018-04-01

Using a sample of 472 local Universe (z < 0.06) galaxies in the stellar mass range 10.25< log M_{\\star }/M_{⊙}<10.75, we explore the variation in galaxy structure as a function of morphology and galaxy colour. Our sample of galaxies is sub-divided into red, green and blue colour groups and into elliptical and non-elliptical (disk-type) morphologies. Using KiDS and VIKING derived postage stamp images, a group of eight volunteers visually classified bars, rings, morphological lenses, tidal streams, shells and signs of merger activity for all systems. We find a significant surplus of rings (2.3σ) and lenses (2.9σ) in disk-type galaxies as they transition across the green valley. Combined, this implies a joint ring/lens green valley surplus significance of 3.3σ relative to equivalent disk-types within either the blue cloud or the red sequence. We recover a bar fraction of ˜44% which remains flat with colour, however, we find that the presence of a bar acts to modulate the incidence of rings and (to a lesser extent) lenses, with rings in barred disk-type galaxies more common by ˜20 - 30 percentage points relative to their unbarred counterparts, regardless of colour. Additionally, green valley disk-type galaxies with a bar exhibit a significant 3.0σ surplus of lenses relative to their blue/red analogues. The existence of such structures rules out violent transformative events as the primary end-of-life evolutionary mechanism, with a more passive scenario the favoured candidate for the majority of galaxies rapidly transitioning across the green valley.

Botanical origin, colour, granulation, and sensory properties of the Harenna forest honey, Bale, Ethiopia.

PubMed

Belay, Abera; Solomon, W K; Bultossa, Geremew; Adgaba, Nuru; Melaku, Samuel

2015-01-15

In this study, the Harenna forest honey samples were investigated with respect to their botanical origin, granulation, colour and sensory properties. Sixteen honey samples were collected from two representative sites (Chiri, C, and Wabero, W) using random sampling techniques. Botanical origin was investigated using qualitative pollen analysis by counting 500 pollen grains using harmonised methods of melissopalynology. Granulation, colour, and sensory properties of honey were determined by visual observation, using Pfund grader, acceptability and preference tests, respectively. Honey samples were also tested for tetracycline. Honey obtained from Wabero is originated dominantly from Syzygium guineense while Chiri was multifloral. The colour of honey ranged from 34 to 85 with light amber and extra light amber colours. The honey samples were free from tetracycline residue and form coarse granules slowly. Significant variation (p>0.05) in sensory preference and acceptability tests not observed due to hive types and locations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Classical lepidopteran wing scale colouration in the giant butterfly-moth Paysandisia archon.

PubMed

Stavenga, Doekele G; Leertouwer, Hein L; Meglič, Andrej; Drašlar, Kazimir; Wehling, Martin F; Pirih, Primož; Belušič, Gregor

2018-01-01

The palm borer moth Paysandisia archon (Castniidae; giant butterfly-moths) has brown dorsal forewings and strikingly orange-coloured dorsal hindwings with white spots surrounded by black margins. Here, we have studied the structure and pigments of the wing scales in the various coloured wing areas, applying light and electron microscopy and (micro)spectrophotometry, and we analysed the spatial reflection properties with imaging scatterometry. The scales in the white spots are unpigmented, those in the black and brown wing areas contain various amounts of melanin, and the orange wing scales contain a blue-absorbing ommochrome pigment. In all scale types, the upper lamina acts as a diffuser and the lower lamina as a thin film interference reflector, with thickness of about 200 nm. Scale stacking plays an important role in creating the strong visual signals: the colour of the white eyespots is created by stacks of unpigmented blue scales, while the orange wing colour is strongly intensified by stacking the orange scales.

Selection for intramuscular fat and lean meat yield will improve the bloomed colour of Australian lamb loin meat.

PubMed

Calnan, H B; Jacob, R H; Pethick, D W; Gardner, G E

2017-09-01

The colour of bloomed m. longissimus was measured 24h post slaughter for 8165 lamb carcasses produced over 5years across 8 sites in Australia. Intramuscular fat across a 2 to 8% range and shortloin fat weight were positively associated with meat lightness (L*), redness (a*), yellowness (b*), hue and chroma (P<0.01). Shortloin muscle weight was negatively associated with these meat colour parameters (P<0.01), although this was largely accounted for by correlated changes in intramuscular fat (P<0.01). The effect of sire breeding values for lamb weight, shortloin muscle depth and fat depth on loin L*, a*, b*, hue and chroma were small and varied between lambs of different sire type, dam breed and sex. Thus selection for lean meat yield will have neutral or positive effects on meat colour, while selection for increased intramuscular fat will make the bloomed colour of lamb meat lighter and redder. Copyright © 2017. Published by Elsevier Ltd.

Polarization properties and microfacet-based modelling of white, grey and coloured matte diffuse reflection standards

NASA Astrophysics Data System (ADS)

Quast, T.; Schirmacher, A.; Hauer, K.-O.; Koo, A.

2018-02-01

To elucidate the influence of polarization in diffuse reflectometry, we performed a series of measurements in several bidirectional geometries and determined the Stokes parameters of the diffusely reflected radiation. Different types of matte reflection standards were used, including several common white standards and ceramic colour standards. The dependence of the polarization on the sample type, wavelength and geometry have been studied systematically, the main influence factors have been identified: The effect is largest at large angles of incidence or detection and at wavelengths where the magnitude of the reflectance is small. The results for the colour standards have been modelled using a microfacet-based reflection theory which is derived from the well-known model of Torrance and Sparrow. Although the theory is very simple and only has three free parameters, the agreement with the measured data is very good, all essential features of the data can be reproduced by the model.

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

Detection experiments with humans implicate visual predation as a driver of colour polymorphism dynamics in pygmy grasshoppers

PubMed Central

2013-01-01

Background Animal colour patterns offer good model systems for studies of biodiversity and evolution of local adaptations. An increasingly popular approach to study the role of selection for camouflage for evolutionary trajectories of animal colour patterns is to present images of prey on paper or computer screens to human ‘predators’. Yet, few attempts have been made to confirm that rates of detection by humans can predict patterns of selection and evolutionary modifications of prey colour patterns in nature. In this study, we first analyzed encounters between human ‘predators’ and images of natural black, grey and striped colour morphs of the polymorphic Tetrix subulata pygmy grasshoppers presented on background images of unburnt, intermediate or completely burnt natural habitats. Next, we compared detection rates with estimates of capture probabilities and survival of free-ranging grasshoppers, and with estimates of relative morph frequencies in natural populations. Results The proportion of grasshoppers that were detected and time to detection depended on both the colour pattern of the prey and on the type of visual background. Grasshoppers were detected more often and faster on unburnt backgrounds than on 50% and 100% burnt backgrounds. Striped prey were detected less often than grey or black prey on unburnt backgrounds; grey prey were detected more often than black or striped prey on 50% burnt backgrounds; and black prey were detected less often than grey prey on 100% burnt backgrounds. Rates of detection mirrored previously reported rates of capture by humans of free-ranging grasshoppers, as well as morph specific survival in the wild. Rates of detection were also correlated with frequencies of striped, black and grey morphs in samples of T. subulata from natural populations that occupied the three habitat types used for the detection experiment. Conclusions Our findings demonstrate that crypsis is background-dependent, and implicate visual predation as an important driver of evolutionary modifications of colour polymorphism in pygmy grasshoppers. Our study provides the clearest evidence to date that using humans as ‘predators’ in detection experiments may provide reliable information on the protective values of prey colour patterns and of natural selection and microevolution of camouflage in the wild. PMID:23639215

Coloured Petri Net Refinement Specification and Correctness Proof with Coq

NASA Technical Reports Server (NTRS)

Choppy, Christine; Mayero, Micaela; Petrucci, Laure

2009-01-01

In this work, we address the formalisation of symmetric nets, a subclass of coloured Petri nets, refinement in COQ. We first provide a formalisation of the net models, and of their type refinement in COQ. Then the COQ proof assistant is used to prove the refinement correctness lemma. An example adapted from a protocol example illustrates our work.

Dermoscopic nevus patterns in skin of colour: a prospective, cross-sectional, morphological study in individuals with skin type V and VI.

PubMed

Lallas, A; Reggiani, C; Argenziano, G; Kyrgidis, A; Bakos, R; Masiero, N C M S; Scheibe, A B; Cabo, H; Ozdemir, F; Sortino-Rachou, A M; Turk, B Gerceker; Moscarella, E; Longo, C; Zalaudek, I

2014-11-01

Most of the knowledge on the prevailing dermoscopic patterns of acquired melanocytic nevi (AMV) is based on studies in Caucasians, while little research focuses on the dermoscopic variability in nevi in skin of colour. To analyse the prevalent dermoscopic nevus patterns in subjects with a skin type (ST) V and VI. Prospective, cross-sectional, morphological study was conducted in six clinics with enrolment of consecutive individuals with a ST V or VI. Digital dermoscopic images of selected representative AMN were assessed for dermoscopic colours, morphological patterns and pigment distribution. Analysis of 300 nevi from subjects with ST V and VI revealed significant differences in the nevus pattern between these two groups. The majority of nevi in ST V revealed a reticular pattern, whereas persons with ST VI more frequently exhibited a structureless pattern. Black, blue and grey were more frequent in ST VI, whereas the vast majority of nevi in ST V individuals showed dark brown colour. Our study provides new insights into the nevus pattern in individuals with a dark pigmentary trait, which may aid the diagnosis and management of nevi in this patients group. © 2013 European Academy of Dermatology and Venereology.

Sensory generalization and learning about novel colours by poultry chicks.

PubMed

Osorio, Daniel; Ham, Abigail D; Gonda, Zsusanna; Andrew, Richard J

2009-07-01

In nature animals constantly encounter novel stimuli and need to generalize from known stimuli. The animal may then learn about the novel stimulus. Hull (1947) suggested that as they learn animals distinguish knowledge based on direct experience from inference by generalization and in support of this view suggested that if a subject is directly trained to a stimulus subsequent extinction of responses is slower than when the response is based on generalization. Such an effect is also predicted by Bayesian models that relate the rate of learning to uncertainty in the estimate of stimulus value. We find support for this prediction when chicks learn about a novel colour (orange) if the initial evaluation is based on similarity to known colours (red, yellow). Specifically, if an expected food reward is absent the rate of extinction of the response to the novel stimulus exceeds that for the familiar colours. Interestingly, the change in relative preference for novel and familiar stimuli occurs after a delay of an hour. This type of delay has not, to our knowledge, been reported in previous studies of single-trial learning, but given its importance of generalization in natural behaviour this type of learning may have wide relevance.

An optical/NIR survey of globular clusters in early-type galaxies. III. On the colour bimodality of globular cluster systems

NASA Astrophysics Data System (ADS)

Chies-Santos, A. L.; Larsen, S. S.; Cantiello, M.; Strader, J.; Kuntschner, H.; Wehner, E. M.; Brodie, J. P.

2012-03-01

Context. The interpretation that bimodal colour distributions of globular clusters (GCs) reflect bimodal metallicity distributions has been challenged. Non-linearities in the colour to metallicity conversions caused for example by the horizontal branch (HB) stars may be responsible for transforming a unimodal metallicity distribution into a bimodal (optical) colour distribution. Aims: We study optical/near-infrared (NIR) colour distributions of the GC systems in 14 E/S0 galaxies. Methods: We test whether the bimodal feature, generally present in optical colour distributions, remains in the optical/NIR ones. The latter colour combination is a better metallicity proxy than the former. We use KMM and GMM tests to quantify the probability that different colour distributions are better described by a bimodal, as opposed to a unimodal distribution. Results: We find that double-peaked colour distributions are more commonly seen in optical than in optical/NIR colours. For some of the galaxies where the optical (g - z) distribution is clearly bimodal, a bimodal distribution is not preferred over a unimodal one at a statistically significant level for the (g - K) and (z - K) distributions. The two most cluster-rich galaxies in our sample, NGC 4486 and NGC 4649, show some interesting differences. The (g - K) distribution of NGC 4649 is better described by a bimodal distribution, while this is true for the (g - K) distribution of NGC 4486 GCs only if restricted to a brighter sub-sample with small K-band errors (<0.05 mag). Formally, the K-band photometric errors cannot be responsible for blurring bimodal metallicity distributions to unimodal (g - K) colour distributions. However, simulations including the extra scatter in the colour-colour diagrams (not fully accounted for in the photometric errors) show that such scatter may contribute to the disappearance of bimodality in (g - K) for the full NGC 4486 sample. For the less cluster-rich galaxies results are inconclusive due to poorer statistics. Conclusions: A bimodal optical colour distribution is not necessarily an indication of an underlying bimodal metallicity distribution. Horizontal branch morphology may play an important role in shaping some of the optical GC colour distributions. However, we find tentative evidence that the (g - K) colour distributions remain bimodal in the two cluster-rich galaxies in our sample (NGC 4486 and NGC 4649) when restricted to clusters with small K-band photometric errors. This bimodality becomes less pronounced when including objects with larger errors, or for the (z - K) colour distributions. Deeper observations of large numbers of GCs will be required to reach more secure conclusions.

Genetics and evolution of colour patterns in reptiles.

PubMed

Olsson, Mats; Stuart-Fox, Devi; Ballen, Cissy

2013-01-01

The study of coloration in the polyphyletic reptilians has flourished in the last two decades, in particular with respect to the underlying genetics of colour traits, the function of colours in social interactions, and ongoing selection on these traits in the wild. The taxonomic bias, however, is profound: at this level of resolution almost all available information is for diurnal lizards. Therefore, we focus on case studies, for which there are as complete causal sequences of colour evolution as possible, from phenotypic expression of variation in colour, to ongoing selection in the wild. For work prior to 1992 and for a broader coverage of reptilian coloration we refer the readers to Cooper and Greenburg's (Biology of the Reptilia, 1992) review. There are seven major conclusions we would like to emphasise: (a) visual systems in diurnal lizards are broadly conserved but among the wider range of reptiles in general, there is functionally important variation in the number and type of photoreceptors, spectral tuning of photopigments and optical properties of the eye; (b) coloration in reptiles is a function of complex interactions between structural and pigmentary components, with implications for both proximate control and condition dependence of colour expression; (c) studies of colour-variable species have enabled estimates of heritability of colour and colour patterns, which often show a simple Mendelian pattern of inheritance; (d) colour-polymorphic lizard species sometimes, but not always, show striking differences in genetically encoded reproductive tactics and provide useful models for studying the evolution and maintenance of polymorphism; (e) both male and female colours are sometimes, but not always, a significant component of socio-sexual signalling, often based on multiple traits; (f) evidence for effects of hormones and condition on colour expression, and trade-offs with immunocompetence and parasite load, is variable; (g) lizards show fading of colours in response to physiological stress and ageing and are hence likely to be appropriate models for work on the interactions between handicaps, indicator traits, parasitology and immunoecology. Copyright © 2013 Elsevier Ltd. All rights reserved.

Gas discharge headlights and visibility of coloured road signs.

PubMed

Venkatachalam, Kannan; Smith, George

2000-01-01

BACKGROUND: Automotive headlamps mostly use the tungsten halogen bulb but several years ago a new type of headlamp, the gas discharge bulb, was introduced. Because of the different spectral output of this type of lamp, there has been a suggestion that it may affect the colour recognition and sign conspicuity under night-time conditions. In this study, the visibility of the road signs is used to examine the effect of the gas discharge lamp's spectrum compared with that of the conventional halogen headlamp. METHODS: The spectral output of the lamps and the spectral reflectance of common-coloured road signs were measured using a Spectra-Pritchard spectroradiometer. Using luminous reflectance data, chromaticity co-ordinates and the colorimetric shift of the road signs, when illuminated by gas discharge lamps, were plotted using CIE x,y co-ordinate system. Colour rendering indices of the lamp were calculated using Munsell samples and road signs as proscribed by the CIE Publication. In addition, the visibility index of the road signs was calculated using Adrian's 'Visibility of Target' model. RESULTS: The gas discharge headlamp has more energy in the blue region and less energy in the red region of the spectrum than the halogen headlamp. The general colour rendering index of the gas discharge lamp is higher than that of the halogen lamp. When compared with daylight, all coloured road signs used in this study have less colorimetric shift when illuminated by the gas discharge headlamp than by the halogen headlamp. CONCLUSION: The result indicates that the gas discharge lamp, while having a very different spectrum from daylight or tungsten halogen lamps, should not have a deleterious effect on sign detection or recognition, when compared to daylight or tungsten halogen lamps.

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

The control of attentional target selection in a colour/colour conjunction task.

PubMed

Berggren, Nick; Eimer, Martin

2016-11-01

To investigate the time course of attentional object selection processes in visual search tasks where targets are defined by a combination of features from the same dimension, we measured the N2pc component as an electrophysiological marker of attentional object selection during colour/colour conjunction search. In Experiment 1, participants searched for targets defined by a combination of two colours, while ignoring distractor objects that matched only one of these colours. Reliable N2pc components were triggered by targets and also by partially matching distractors, even when these distractors were accompanied by a target in the same display. The target N2pc was initially equal in size to the sum of the two N2pc components to the two different types of partially matching distractors and became superadditive from approximately 250 ms after search display onset. Experiment 2 demonstrated that the superadditivity of the target N2pc was not due to a selective disengagement of attention from task-irrelevant partially matching distractors. These results indicate that attention was initially deployed separately and in parallel to all target-matching colours, before attentional allocation processes became sensitive to the presence of both matching colours within the same object. They suggest that attention can be controlled simultaneously and independently by multiple features from the same dimension and that feature-guided attentional selection processes operate in parallel for different target-matching objects in the visual field.

Are the unken reflex and the aposematic colouration of Red-Bellied Toads efficient against bird predation?

PubMed Central

Caorsi, Valentina Zaffaroni; Colombo, Patrick; Abadie, Michelle; Brack, Ismael Verrastro; Dasoler, Bibiana Terra; Borges-Martins, Márcio

2018-01-01

Aposematic signals as well as body behaviours may be important anti-predator defences. Species of the genus Melanophryniscus are characterised by having toxic lipophilic alkaloids in the skin and for presenting a red ventral colouration, which can be observed when they perform the behaviour called the unken reflex. Both the reflex behaviour and the colouration pattern are described as defence mechanisms. However, there are currently no studies testing their effectiveness against predators. This study aimed to test experimentally if both ventral conspicuous colouration and the unken reflex in Melanophryniscus cambaraensis function as aposematic signals against visually oriented predators (birds). We simulated the species studied using three different clay toad models as follows: (a) in a normal position with green coloured bodies, (b) in the unken reflex position with green coloured body and extremities and (c) in the unken reflex position with a green body and red extremities. Models were distributed on a known M. cambaraensis breeding site and in the adjacent forest. More than half of the attacks on the models were from birds; however, there was no preference for any model type. Thus, just the presence of the red colour associated with the motionless unken reflex position does not seem to prevent attacks from potential predators. It is possible that the effective aposematic signal in Melanophryniscus is achieved through the unken reflex movement together with the subsequent exhibition of the warning colouration and the secretion of toxins. PMID:29596437

Colour blindness of the movement-detecting system of the spider Cupiennius salei.

PubMed

Orlando, Eva; Schmid, Axel

2011-02-15

The nocturnal wandering spider Cupiennius salei has one pair of principal eyes and three pairs of secondary eyes located on the prosoma, which differ in both morphology and function. Their spectral sensitivity, measured with intracellular recordings, is due to three different types of photoreceptors with absorbance maxima in the mid-range of the spectrum, at 480 nm and 520 nm and in the UV at 360 nm. Based on these physiological data colour vision might be possible. In the present study, the ability to discriminate coloured moving stimuli from grey backgrounds was tested. The perception of moving coloured stripes in front of backgrounds with 29 different grey levels was measured by using extracellular recordings from the anterior median eye muscles as a monitoring system. Each of these eyes has two muscles, which increase their activity when moving stimuli are presented in front of a secondary eye. This variation in eye muscle activity can be recorded extracellulary in a living spider using a single channel telemetry device. If colour perception exists, the animal should be able to detect a moving coloured stripe in front of any grey level. Blue, green and red stripes were used as moving stimuli, in front of all 29 grey backgrounds. The results indicate that C. salei is not able to discriminate the coloured stimuli from distinct shades of grey. It is therefore evident that the movement-detecting system in this spider appears to be colour blind.

Phenotypic characterisation of colour stability of lamb meat.

PubMed

Jacob, Robin H; D'Antuono, Mario F; Gilmour, Arthur R; Warner, Robyn D

2014-02-01

A study was undertaken, using 2701 overwrapped loin samples aged for 5 days and subjected to a simulated retail display (SRD) for 3 days; sourced from lambs in the Cooperative Research Centre for Sheep Industry Innovation information nucleus flock, born 2007-2009. The ratio of reflectance of light in the wavelengths of 630 nm and 580 nm (oxy/met) was measured daily during the SRD, using a Hunterlab spectrophotometer. A series of linear mixed models was fitted to the oxy/met and time data to compare 4 breed types and identify relevant covariates, of 19, using a forward selection process. Breed type, pH at 24 h post slaughter and Linoleic acid concentration (LA) were the most important factors and covariates, in that order. Merino breed type, high pH and high LA reduced colour stability. Fitting a spline model to predict the time for oxy/met to reach a set value, represents an alternative to comparing oxy/met at a set time, for describing colour stability. Copyright © 2012 The Authors. Published by Elsevier Ltd.. All rights reserved.

Use of colour Doppler and M-mode ultrasonography to confirm the location of an epidural catheter - a retrospective case series.

PubMed

Elsharkawy, Hesham; Sonny, Abraham; Govindarajan, Srinivasa Raghavan; Chan, Vincent

2017-05-01

Epidural anesthesia and analgesia has a reported failure rate ranging from 13% to 32%. We describe a technique using colour Doppler and M-mode ultrasonography to determine the position of the epidural catheter after placement in adults. This retrospective review included 37 adult patients who received postoperative epidural analgesia and underwent technically difficult epidural catheter placement. The demographic characteristics, type of surgery, use of ultrasonography, method of insertion, intervertebral level, and success of epidural localization using colour Doppler were noted for each patient. Pain scores on postoperative day 1 and the presence of a patchy block were also reviewed. Colour Doppler study helped to indicate the catheter's path from the skin to the epidural space during saline injection in 33 patients (89%). Saline flow within the epidural space (catheter tip confirmation) was successfully detected with colour Doppler in 25 patients (67.5%) and with M-mode ultrasonography in 28 patients (75%). Appropriate dermatomal analgesia was noted in 35 patients (94.5%) during local anesthetic infusion. Our preliminary data suggest the feasibility of using colour Doppler and M-mode ultrasonography to confirm proper epidural catheter placement.

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.

Gaze Duration Biases for Colours in Combination with Dissonant and Consonant Sounds: A Comparative Eye-Tracking Study with Orangutans.

PubMed

Mühlenbeck, Cordelia; Liebal, Katja; Pritsch, Carla; Jacobsen, Thomas

2015-01-01

Research on colour preferences in humans and non-human primates suggests similar patterns of biases for and avoidance of specific colours, indicating that these colours are connected to a psychological reaction. Similarly, in the acoustic domain, approach reactions to consonant sounds (considered as positive) and avoidance reactions to dissonant sounds (considered as negative) have been found in human adults and children, and it has been demonstrated that non-human primates are able to discriminate between consonant and dissonant sounds. Yet it remains unclear whether the visual and acoustic approach-avoidance patterns remain consistent when both types of stimuli are combined, how they relate to and influence each other, and whether these are similar for humans and other primates. Therefore, to investigate whether gaze duration biases for colours are similar across primates and whether reactions to consonant and dissonant sounds cumulate with reactions to specific colours, we conducted an eye-tracking study in which we compared humans with one species of great apes, the orangutans. We presented four different colours either in isolation or in combination with consonant and dissonant sounds. We hypothesised that the viewing time for specific colours should be influenced by dissonant sounds and that previously existing avoidance behaviours with regard to colours should be intensified, reflecting their association with negative acoustic information. The results showed that the humans had constant gaze durations which were independent of the auditory stimulus, with a clear avoidance of yellow. In contrast, the orangutans did not show any clear gaze duration bias or avoidance of colours, and they were also not influenced by the auditory stimuli. In conclusion, our findings only partially support the previously identified pattern of biases for and avoidance of specific colours in humans and do not confirm such a pattern for orangutans.

Gaze Duration Biases for Colours in Combination with Dissonant and Consonant Sounds: A Comparative Eye-Tracking Study with Orangutans

PubMed Central

Mühlenbeck, Cordelia; Liebal, Katja; Pritsch, Carla; Jacobsen, Thomas

2015-01-01

Research on colour preferences in humans and non-human primates suggests similar patterns of biases for and avoidance of specific colours, indicating that these colours are connected to a psychological reaction. Similarly, in the acoustic domain, approach reactions to consonant sounds (considered as positive) and avoidance reactions to dissonant sounds (considered as negative) have been found in human adults and children, and it has been demonstrated that non-human primates are able to discriminate between consonant and dissonant sounds. Yet it remains unclear whether the visual and acoustic approach–avoidance patterns remain consistent when both types of stimuli are combined, how they relate to and influence each other, and whether these are similar for humans and other primates. Therefore, to investigate whether gaze duration biases for colours are similar across primates and whether reactions to consonant and dissonant sounds cumulate with reactions to specific colours, we conducted an eye-tracking study in which we compared humans with one species of great apes, the orangutans. We presented four different colours either in isolation or in combination with consonant and dissonant sounds. We hypothesised that the viewing time for specific colours should be influenced by dissonant sounds and that previously existing avoidance behaviours with regard to colours should be intensified, reflecting their association with negative acoustic information. The results showed that the humans had constant gaze durations which were independent of the auditory stimulus, with a clear avoidance of yellow. In contrast, the orangutans did not show any clear gaze duration bias or avoidance of colours, and they were also not influenced by the auditory stimuli. In conclusion, our findings only partially support the previously identified pattern of biases for and avoidance of specific colours in humans and do not confirm such a pattern for orangutans. PMID:26466351

The phylogenetic significance of colour patterns in marine teleost larvae

PubMed Central

Baldwin, Carole C

2013-01-01

Ichthyologists, natural-history artists, and tropical-fish aquarists have described, illustrated, or photographed colour patterns in adult marine fishes for centuries, but colour patterns in marine fish larvae have largely been neglected. Yet the pelagic larval stages of many marine fishes exhibit subtle to striking, ephemeral patterns of chromatophores that warrant investigation into their potential taxonomic and phylogenetic significance. Colour patterns in larvae of over 200 species of marine teleosts, primarily from the western Caribbean, were examined from digital colour photographs, and their potential utility in elucidating evolutionary relationships at various taxonomic levels was assessed. Larvae of relatively few basal marine teleosts exhibit erythrophores, xanthophores, or iridophores (i.e. nonmelanistic chromatophores), but one or more of those types of chromatophores are visible in larvae of many basal marine neoteleosts and nearly all marine percomorphs. Whether or not the presence of nonmelanistic chromatophores in pelagic marine larvae diagnoses any major teleost taxonomic group cannot be determined based on the preliminary survey conducted, but there is a trend toward increased colour from elopomorphs to percomorphs. Within percomorphs, patterns of nonmelanistic chromatophores may help resolve or contribute evidence to existing hypotheses of relationships at multiple levels of classification. Mugilid and some beloniform larvae share a unique ontogenetic transformation of colour pattern that lends support to the hypothesis of a close relationship between them. Larvae of some tetraodontiforms and lophiiforms are strikingly similar in having the trunk enclosed in an inflated sac covered with xanthophores, a character that may help resolve the relationships of these enigmatic taxa. Colour patterns in percomorph larvae also appear to diagnose certain groups at the interfamilial, familial, intergeneric, and generic levels. Slight differences in generic colour patterns, including whether the pattern comprises xanthophores or erythrophores, often distinguish species. The homology, ontogeny, and possible functional significance of colour patterns in larvae are discussed. Considerably more investigation of larval colour patterns in marine teleosts is needed to assess fully their value in phylogenetic reconstruction. PMID:24039297

Properties of Am, Delta Del and Delta SCT stars in the VBLUW system

NASA Astrophysics Data System (ADS)

Wiertz, M. J. J.; van Genderen, A. M.

1983-05-01

VBLUW photometric observations of 115 Am, δ Del, and δ Sct stars are presented and discussed. The spread with respect to the main sequence in the two-colour diagrams is mainly attributed to gravity effects. Temperatures and gravities compare reasonably well with those of Davis Philip et al. (1976) based on uvbyß photometry. However, the temperatures derived by Babu and Shylaja (1981, 1982) and based on spectral energy distribution, reveal that the photometric temperatures (and thus also gravities) are underestimated. The relation between the temperature sensitive colour indices V-B (of the VBLUW system), b-y (ubvyß system) and B2-V1 (Geneva system) for A/F type stars is investigated. A PLC relation for the colour V-B is derived using Breger's (1979) relation for the colour b-y.

Self-assessment of pubertal Tanner stage by realistic colour images in representative Chinese obese and non-obese children and adolescents.

PubMed

Sun, Ying; Tao, Fang-Biao; Su, Pu-Yu

2012-04-01

This investigation aims to evaluate the validity of self-assessment of pubertal Tanner stage in representative Chinese children and adolescents. The study is a nationally representative cross-sectional survey in eight research sites in the large project entitled 'China Puberty Research Collaboration'. Weight, height, self-assessed pubertal Tanner stage and physical examination of pubic hair in each gender, breast development in girls and genital development in boys from were analysed. Realistic colour images of pubertal rating were used as self-assessment of pubertal stage. A large proportion of subjects aged 7.9-18.9 years old were capable of identifying their own pubertal Tanner stage accurately or close to the rater's assessments. Obese group tends to overestimate their pubertal development compared to non-obese peers, except for genital assessment in boys. The k values for non-obese and obese girls were 0.619 (p < 0.0001) and 0.527 (p < 0.0001), respectively, while the k values for non-obese and obese boys were 0.503 (p < 0.0001) and 0.352 (p < 0.0001). Self-assessment of the pubertal stage by using realistic colour images could be a better alternative assessment tool for large epidemiological puberty research compared with Tanner's original black and white pictures. © 2011 The Author(s)/Acta Paediatrica © 2011 Foundation Acta Paediatrica.

Photometric catalogue for stars in Selected Areas and other fields inthe RGU-system (X). Photometry of fields in and near to the Milky Way: Anticenter 5, Carina (IC 2581), Centaurus III, Aquila II, Cassiopeia(NGC 7654).

NASA Astrophysics Data System (ADS)

Becker, W.; Fenkart, R. P.; Spaenhauer, A.; Alfaro, E. A.; Kandemir, G.; Karaali, S.; Fang, C.; Garcia-Pelayo, J. M.; Steppe, H.; Topaktas, L.

The tenth volume of the Basle Photometric Catalogues contains the G-magnitudes, as well as the long- (G-R) and short-wave (U-G) colour indices of the stars in five galactic fields. Additionally, data as obtained from the interpretationof the two-colour diagrams are given, i.e.: if the star in question has been identified as a main-sequence star of either population, or asa late-type giant, or if it is blended on the photographic plates of one or more colours.

Fundus autofluorescence and colour fundus imaging compared during telemedicine screening in patients with diabetes.

PubMed

Kolomeyer, Anton M; Baumrind, Benjamin R; Szirth, Bernard C; Shahid, Khadija; Khouri, Albert S

2013-06-01

We investigated the use of fundus autofluorescence (FAF) imaging in screening the eyes of patients with diabetes. Images were obtained from 50 patients with type 2 diabetes undergoing telemedicine screening with colour fundus imaging. The colour and FAF images were obtained with a 15.1 megapixel non-mydriatic retinal camera. Colour and FAF images were compared for pathology seen in nonproliferative and proliferative diabetic retinopathy (NPDR and PDR, respectively). A qualitative assessment was made of the ease of detecting early retinopathy changes and the extent of existing retinopathy. The mean age of the patients was 47 years, most were male (82%) and most were African American (68%). Their mean visual acuity was 20/45 and their mean intraocular pressure was 14.3 mm Hg. Thirty-eight eyes (76%) did not show any diabetic retinopathy changes on colour or FAF imaging. Seven patients (14%) met the criteria for NPDR and five (10%) for severe NPDR or PDR. The most common findings were microaneurysms, hard exudates and intra-retinal haemorrhages (IRH) (n = 6 for each). IRH, microaneurysms and chorioretinal scars were more easily visible on FAF images. Hard exudates, pre-retinal haemorrhage and fibrosis, macular oedema and Hollenhorst plaque were easier to identify on colour photographs. The value of FAF imaging as a complementary technique to colour fundus imaging in detecting diabetic retinopathy during ocular screening warrants further investigation.

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.

Quantifying Variability of Avian Colours: Are Signalling Traits More Variable?

PubMed Central

Delhey, Kaspar; Peters, Anne

2008-01-01

Background Increased variability in sexually selected ornaments, a key assumption of evolutionary theory, is thought to be maintained through condition-dependence. Condition-dependent handicap models of sexual selection predict that (a) sexually selected traits show amplified variability compared to equivalent non-sexually selected traits, and since males are usually the sexually selected sex, that (b) males are more variable than females, and (c) sexually dimorphic traits more variable than monomorphic ones. So far these predictions have only been tested for metric traits. Surprisingly, they have not been examined for bright coloration, one of the most prominent sexual traits. This omission stems from computational difficulties: different types of colours are quantified on different scales precluding the use of coefficients of variation. Methodology/Principal Findings Based on physiological models of avian colour vision we develop an index to quantify the degree of discriminable colour variation as it can be perceived by conspecifics. A comparison of variability in ornamental and non-ornamental colours in six bird species confirmed (a) that those coloured patches that are sexually selected or act as indicators of quality show increased chromatic variability. However, we found no support for (b) that males generally show higher levels of variability than females, or (c) that sexual dichromatism per se is associated with increased variability. Conclusions/Significance We show that it is currently possible to realistically estimate variability of animal colours as perceived by them, something difficult to achieve with other traits. Increased variability of known sexually-selected/quality-indicating colours in the studied species, provides support to the predictions borne from sexual selection theory but the lack of increased overall variability in males or dimorphic colours in general indicates that sexual differences might not always be shaped by similar selective forces. PMID:18301766

In multiple situational light settings, visual observation for skin colour assessment is comparable with colorimeter measurement.

PubMed

Wright, C Y; Wilkes, M; du Plessis, J L; Reeder, A I; Albers, P N

2016-08-01

Finding inexpensive and reliable techniques for assessing skin colour is important, given that it is related to several adverse human health outcomes. Visual observation is considered a subjective approach assessment and, even when made by trained assessor, concern has been raised about the need for controlled lighting in the study venue. The aim of this study is to determine whether visual skin colour assessments correlate with objective skin colour measurements in study venues with different lighting types and configurations. Two trained investigators, with confirmed visual acuity, visually classified the inner, upper arm skin colour of 556 adults using Munsell(®) colour classifications converted to Individual Typology Angle (°ITA) values based on published data. Skin colour at the same anatomic site was also measured using a colorimeter. Each participant was assessed in one of 10 different buildings, each with a different study day. Munsell(®) -derived °ITA values were compared to colorimeter °ITA values for the full sample and by building/day. We found a strong positive, monotonic correlation between Munsell(®) derived °ITA values and colorimeter °ITA values for all participants (Spearman ρ = 0.8585, P < 0.001). Similar relationships were found when Munsell(®) and colorimeter °ITA values were compared for participants assessed in the same building for all 10 buildings (Spearman ρ values ranged from 0.797 to 0.934, all correlations were statistically significant at P < 0.001). It is possible to visually assess individual skin colour in multiple situational lighting settings and retrieve results that are comparable with objective measurements of skin colour. This was true for individuals of varying population groups and skin pigmentation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Analysis of the color rendition of flexible endoscopes

NASA Astrophysics Data System (ADS)

Murphy, Edward M.; Hegarty, Francis J.; McMahon, Barry P.; Boyle, Gerard

2003-03-01

Endoscopes are imaging devices routinely used for the diagnosis of disease within the human digestive tract. Light is transmitted into the body cavity via incoherent fibreoptic bundles and is controlled by a light feedback system. Fibreoptic endoscopes use coherent fibreoptic bundles to provide the clinician with an image. It is also possible to couple fibreoptic endoscopes to a clip-on video camera. Video endoscopes consist of a small CCD camera, which is inserted into gastrointestinal tract, and associated image processor to convert the signal to analogue RGB video signals. Images from both types of endoscope are displayed on standard video monitors. Diagnosis is dependent upon being able to determine changes in the structure and colour of tissues and biological fluids, and therefore is dependent upon the ability of the endoscope to reproduce the colour of these tissues and fluids with fidelity. This study investigates the colour reproduction of flexible optical and video endoscopes. Fibreoptic and video endoscopes alter image colour characteristics in different ways. The colour rendition of fibreoptic endoscopes was assessed by coupling them to a video camera and applying video colorimetric techniques. These techniques were then used on video endoscopes to assess how the colour rendition of video endoscopes compared with that of optical endoscopes. In both cases results were obtained at fixed illumination settings. Video endoscopes were then assessed with varying levels of illumination. Initial results show that at constant luminance endoscopy systems introduce non-linear shifts in colour. Techniques for examining how this colour shift varies with illumination intensity were developed and both methodology and results will be presented. We conclude that more rigorous quality assurance is required to reduce colour error and are developing calibration procedures applicable to medical endoscopes.

Analysis and classification of commercial ham slice images using directional fractal dimension features.

PubMed

Mendoza, Fernando; Valous, Nektarios A; Allen, Paul; Kenny, Tony A; Ward, Paddy; Sun, Da-Wen

2009-02-01

This paper presents a novel and non-destructive approach to the appearance characterization and classification of commercial pork, turkey and chicken ham slices. Ham slice images were modelled using directional fractal (DF(0°;45°;90°;135°)) dimensions and a minimum distance classifier was adopted to perform the classification task. Also, the role of different colour spaces and the resolution level of the images on DF analysis were investigated. This approach was applied to 480 wafer thin ham slices from four types of hams (120 slices per type): i.e., pork (cooked and smoked), turkey (smoked) and chicken (roasted). DF features were extracted from digitalized intensity images in greyscale, and R, G, B, L(∗), a(∗), b(∗), H, S, and V colour components for three image resolution levels (100%, 50%, and 25%). Simulation results show that in spite of the complexity and high variability in colour and texture appearance, the modelling of ham slice images with DF dimensions allows the capture of differentiating textural features between the four commercial ham types. Independent DF features entail better discrimination than that using the average of four directions. However, DF dimensions reveal a high sensitivity to colour channel, orientation and image resolution for the fractal analysis. The classification accuracy using six DF dimension features (a(90°)(∗),a(135°)(∗),H(0°),H(45°),S(0°),H(90°)) was 93.9% for training data and 82.2% for testing data.

Differentiating Biological Colours with Few and Many Sensors: Spectral Reconstruction with RGB and Hyperspectral Cameras

PubMed Central

Garcia, Jair E.; Girard, Madeline B.; Kasumovic, Michael; Petersen, Phred; Wilksch, Philip A.; Dyer, Adrian G.

2015-01-01

Background The ability to discriminate between two similar or progressively dissimilar colours is important for many animals as it allows for accurately interpreting visual signals produced by key target stimuli or distractor information. Spectrophotometry objectively measures the spectral characteristics of these signals, but is often limited to point samples that could underestimate spectral variability within a single sample. Algorithms for RGB images and digital imaging devices with many more than three channels, hyperspectral cameras, have been recently developed to produce image spectrophotometers to recover reflectance spectra at individual pixel locations. We compare a linearised RGB and a hyperspectral camera in terms of their individual capacities to discriminate between colour targets of varying perceptual similarity for a human observer. Main Findings (1) The colour discrimination power of the RGB device is dependent on colour similarity between the samples whilst the hyperspectral device enables the reconstruction of a unique spectrum for each sampled pixel location independently from their chromatic appearance. (2) Uncertainty associated with spectral reconstruction from RGB responses results from the joint effect of metamerism and spectral variability within a single sample. Conclusion (1) RGB devices give a valuable insight into the limitations of colour discrimination with a low number of photoreceptors, as the principles involved in the interpretation of photoreceptor signals in trichromatic animals also apply to RGB camera responses. (2) The hyperspectral camera architecture provides means to explore other important aspects of colour vision like the perception of certain types of camouflage and colour constancy where multiple, narrow-band sensors increase resolution. PMID:25965264

Qualitative identification of permitted and non-permitted colour additives in food products.

PubMed

Harp, Bhakti Petigara; Miranda-Bermudez, Enio; Baron, Carolina I; Richard, Gerald I

2012-01-01

Colour additives are dyes, pigments or other substances that can impart colour when added or applied to food, drugs, cosmetics, medical devices, or the human body. The substances must be pre-approved by the US Food and Drug Administration (USFDA) and listed in Title 21 of the US Code of Federal Regulations before they may be used in products marketed in the United States. Some also are required to be batch certified by the USFDA prior to their use. Both domestic and imported products sold in interstate commerce fall under USFDA jurisdiction, and the USFDA's district laboratories use a combination of analytical methods for identifying or confirming the presence of potentially violative colour additives. We have developed a qualitative method for identifying 17 certifiable, certification exempt, and non-permitted colour additives in various food products. The method involves extracting the colour additives from a product and isolating them from non-coloured components with a C(18) Sep-Pak cartridge. The colour additives are then separated and identified by liquid chromatography (LC) with photodiode array detection, using an Xterra RP18 column and gradient elution with aqueous ammonium acetate and methanol. Limits of detection (LODs) ranged from 0.02 to 1.49 mg/l. This qualititative LC method supplements the visible spectrophotometric and thin-layer chromatography methods currently used by the USFDA's district laboratories and is less time-consuming and requires less solvent compared to the other methods. The extraction step in the new LC method is a simple and an efficient process that can be used for most food types.

Variation in founder groups promotes establishment success in the wild

PubMed Central

Forsman, Anders; Wennersten, Lena; Karlsson, Magnus; Caesar, Sofia

2012-01-01

Environmental changes currently pose severe threats to biodiversity, and reintroductions and translocations are increasingly used to protect declining populations and species from extinction. Theory predicts that establishment success should be higher for more variable groups of dissimilar individuals. To test this ‘diversity promotes establishment’ hypothesis, we introduced colour polymorphic pygmy grasshoppers (Tetrix subulata) to different sites in the wild. The number of descendants found at the release sites the subsequent year increased with increasing number of colour morphs in the founder group, and variation in founder groups also positively affected colour morph diversity in the established populations. Since colour morphs differ in morphology, physiology, behaviour, reproductive life history and types of niche used, these findings demonstrate that variation among individuals in functionally important traits promotes establishment success under natural conditions, and further indicate that founder diversity may contribute to evolutionary rescue and increased population persistence. PMID:22456885

Iridescence: views from many angles.

PubMed

Meadows, Melissa G; Butler, Michael W; Morehouse, Nathan I; Taylor, Lisa A; Toomey, Matthew B; McGraw, Kevin J; Rutowski, Ronald L

2009-04-06

Iridescent colours have been fascinating to humans throughout history; they are flashy, shimmering, dynamic, and examples surround us, from the commonly seen iridescent sheen of oily street puddles to the exotic, gaudy displays of birds-of-paradise featured in nature documentaries. Iridescent colours and the structures that produce them have unique properties in comparison with other types of colourants found in nature. Scientists from a variety of disciplines study the optics, development, heritability, chemical make-up, origin, evolution, functions and biomimetic technological applications of naturally occurring iridescent colours. For the first time, graduate students at Arizona State University brought together these scientists, along with educators and artists, at 'Iridescence: more than meets the eye', a conference to promote interdisciplinary communication and collaboration in the study of iridescent coloration from all of these perspectives. Here, we summarize the outcomes of this conference, introduce the papers that follow in this special journal issue and briefly review the current status of our understanding of iridescence.

Visuospatial working memory for locations, colours, and binding in typically developing children and in children with dyslexia and non-verbal learning disability.

PubMed

Garcia, Ricardo Basso; Mammarella, Irene C; Tripodi, Doriana; Cornoldi, Cesare

2014-03-01

This study examined forward and backward recall of locations and colours and the binding of locations and colours, comparing typically developing children - aged between 8 and 10 years - with two different groups of children of the same age with learning disabilities (dyslexia in one group, non-verbal learning disability [NLD] in the other). Results showed that groups with learning disabilities had different visuospatial working memory problems and that children with NLD had particular difficulties in the backward recall of locations. The differences between the groups disappeared, however, when locations and colours were bound together. It was concluded that specific processes may be involved in children in the binding and backward recall of different types of information, as they are not simply the resultant of combining the single processes needed to recall single features. © 2013 The British Psychological Society.

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.

Computer vision-based analysis of foods: a non-destructive colour measurement tool to monitor quality and safety.

PubMed

Mogol, Burçe Ataç; Gökmen, Vural

2014-05-01

Computer vision-based image analysis has been widely used in food industry to monitor food quality. It allows low-cost and non-contact measurements of colour to be performed. In this paper, two computer vision-based image analysis approaches are discussed to extract mean colour or featured colour information from the digital images of foods. These types of information may be of particular importance as colour indicates certain chemical changes or physical properties in foods. As exemplified here, the mean CIE a* value or browning ratio determined by means of computer vision-based image analysis algorithms can be correlated with acrylamide content of potato chips or cookies. Or, porosity index as an important physical property of breadcrumb can be calculated easily. In this respect, computer vision-based image analysis provides a useful tool for automatic inspection of food products in a manufacturing line, and it can be actively involved in the decision-making process where rapid quality/safety evaluation is needed. © 2013 Society of Chemical Industry.

Classification of different types of beer according to their colour characteristics

NASA Astrophysics Data System (ADS)

Nikolova, Kr T.; Gabrova, R.; Boyadzhiev, D.; Pisanova, E. S.; Ruseva, J.; Yanakiev, D.

2017-01-01

Twenty-two samples from different beers have been investigated in two colour systems - XYZ and SIELab - and have been characterised according to their colour parameters. The goals of the current study were to conduct correlation and discriminant analysis and to find the inner relation between the studied indices. K-means cluster has been used to compare and group the tested types of beer based on their similarity. To apply the K-Cluster analysis it is required that the number of clusters be determined in advance. The variant K = 4 was worked out. The first cluster unified all bright beers, the second one contained samples with fruits, the third one contained samples with addition of lemon, the fourth unified the samples of dark beers. By applying the discriminant analysis it is possible to help selections in the establishment of the type of beer. The proposed model correctly describes the types of beer on the Bulgarian market and it can be used for determining the affiliation of the beer which is not used in obtained model. One sample has been chosen from each cluster and the digital image has been obtained. It confirms the color parameters in the color system XYZ and SIELab. These facts can be used for elaboration for express estimation of beer by color.

Bona fide colour: DNA prediction of human eye and hair colour from ancient and contemporary skeletal remains

PubMed Central

2013-01-01

Background DNA analysis of ancient skeletal remains is invaluable in evolutionary biology for exploring the history of species, including humans. Contemporary human bones and teeth, however, are relevant in forensic DNA analyses that deal with the identification of perpetrators, missing persons, disaster victims or family relationships. They may also provide useful information towards unravelling controversies that surround famous historical individuals. Retrieving information about a deceased person’s externally visible characteristics can be informative in both types of DNA analyses. Recently, we demonstrated that human eye and hair colour can be reliably predicted from DNA using the HIrisPlex system. Here we test the feasibility of the novel HIrisPlex system at establishing eye and hair colour of deceased individuals from skeletal remains of various post-mortem time ranges and storage conditions. Methods Twenty-one teeth between 1 and approximately 800 years of age and 5 contemporary bones were subjected to DNA extraction using standard organic protocol followed by analysis using the HIrisPlex system. Results Twenty-three out of 26 bone DNA extracts yielded the full 24 SNP HIrisPlex profile, therefore successfully allowing model-based eye and hair colour prediction. HIrisPlex analysis of a tooth from the Polish general Władysław Sikorski (1881 to 1943) revealed blue eye colour and blond hair colour, which was positively verified from reliable documentation. The partial profiles collected in the remaining three cases (two contemporary samples and a 14th century sample) were sufficient for eye colour prediction. Conclusions Overall, we demonstrate that the HIrisPlex system is suitable, sufficiently sensitive and robust to successfully predict eye and hair colour from ancient and contemporary skeletal remains. Our findings, therefore, highlight the HIrisPlex system as a promising tool in future routine forensic casework involving skeletal remains, including ancient DNA studies, for the prediction of eye and hair colour of deceased individuals. PMID:23317428

Bona fide colour: DNA prediction of human eye and hair colour from ancient and contemporary skeletal remains.

PubMed

Draus-Barini, Jolanta; Walsh, Susan; Pośpiech, Ewelina; Kupiec, Tomasz; Głąb, Henryk; Branicki, Wojciech; Kayser, Manfred

2013-01-14

DNA analysis of ancient skeletal remains is invaluable in evolutionary biology for exploring the history of species, including humans. Contemporary human bones and teeth, however, are relevant in forensic DNA analyses that deal with the identification of perpetrators, missing persons, disaster victims or family relationships. They may also provide useful information towards unravelling controversies that surround famous historical individuals. Retrieving information about a deceased person's externally visible characteristics can be informative in both types of DNA analyses. Recently, we demonstrated that human eye and hair colour can be reliably predicted from DNA using the HIrisPlex system. Here we test the feasibility of the novel HIrisPlex system at establishing eye and hair colour of deceased individuals from skeletal remains of various post-mortem time ranges and storage conditions. Twenty-one teeth between 1 and approximately 800 years of age and 5 contemporary bones were subjected to DNA extraction using standard organic protocol followed by analysis using the HIrisPlex system. Twenty-three out of 26 bone DNA extracts yielded the full 24 SNP HIrisPlex profile, therefore successfully allowing model-based eye and hair colour prediction. HIrisPlex analysis of a tooth from the Polish general Władysław Sikorski (1881 to 1943) revealed blue eye colour and blond hair colour, which was positively verified from reliable documentation. The partial profiles collected in the remaining three cases (two contemporary samples and a 14th century sample) were sufficient for eye colour prediction. Overall, we demonstrate that the HIrisPlex system is suitable, sufficiently sensitive and robust to successfully predict eye and hair colour from ancient and contemporary skeletal remains. Our findings, therefore, highlight the HIrisPlex system as a promising tool in future routine forensic casework involving skeletal remains, including ancient DNA studies, for the prediction of eye and hair colour of deceased individuals.

Blue colour preference in honeybees distracts visual attention for learning closed shapes.

PubMed

Morawetz, Linde; Svoboda, Alexander; Spaethe, Johannes; Dyer, Adrian G

2013-10-01

Spatial vision is an important cue for how honeybees (Apis mellifera) find flowers, and previous work has suggested that spatial learning in free-flying bees is exclusively mediated by achromatic input to the green photoreceptor channel. However, some data suggested that bees may be able to use alternative channels for shape processing, and recent work shows conditioning type and training length can significantly influence bee learning and cue use. We thus tested the honeybees' ability to discriminate between two closed shapes considering either absolute or differential conditioning, and using eight stimuli differing in their spectral characteristics. Consistent with previous work, green contrast enabled reliable shape learning for both types of conditioning, but surprisingly, we found that bees trained with appetitive-aversive differential conditioning could additionally use colour and/or UV contrast to enable shape discrimination. Interestingly, we found that a high blue contrast initially interferes with bee shape learning, probably due to the bees innate preference for blue colours, but with increasing experience bees can learn a variety of spectral and/or colour cues to facilitate spatial learning. Thus, the relationship between bee pollinators and the spatial and spectral cues that they use to find rewarding flowers appears to be a more rich visual environment than previously thought.

Fruit or aposematic insect? Context-dependent colour preferences in domestic chicks.

PubMed Central

Gamberale-Stille, G.; Tullberg, B. S.

2001-01-01

Colours are common stimuli in signalling systems. Requirements to function well as a signal sometimes conflict between different signallers, and the same colour stimulus is used to convey completely different messages to the same receiver. Fruits and aposematic insects both use red coloration as a signal, in the former case to signal profitability and in the latter case as a warning signal. In two experiments, we investigated whether the domestic chick, an omnivorous predator, differed in its unconditioned preference or avoidance of red and green stimuli depending on whether or not the stimulus was an insect. The experiments were designed as preference tests between red and green painted prey. The prey were live insects and artificial fruits (experiment 1), and, to investigate the effect of movement, live and dead insects (experiment 2). The chicks did not show any difference in pecking preference between red and green when fruit-like stimuli were used, but when the prey were insects, green prey were strongly preferred to red prey, and prey movement did not affect this bias. Thus, young chicks may recognize prey as insects and then discriminate between different prey colorations, or one type of food may elicit an unlearned colour preference-avoidance response that is absent with another type of food. PMID:11749705

The dark side of sniffing: paint colour affects intoxication experiences among adolescent inhalant users.

PubMed

Takagi, Michael J; Yücel, Murat; Lubman, Dan I

2010-07-01

Inhalant abuse among adolescents is a significant health concern in many countries; however, limited research has explored whether the intoxication experience differs between commonly used inhalants. The aim of the present study was to examine how exposure to different types of paints (chrome vs. non-chrome) were experienced by adolescent users. Sixteen adolescent (aged 15-19 years) regular inhalant users completed a semistructured questionnaire enquiring about their inhalant use. Participants were divided into two groups based on paint colour preference [chrome paints (n = 10) and non-chrome paints (n = 6)] and were compared using appropriate statistical tests. Relative to non-chrome users, the chrome-using group were more likely to report deliberately inhaling to experience altered perceptions (such as visual and auditory hallucinations). In addition, a significantly greater proportion of chrome users reported that the perceptual alterations they experienced after sniffing paint differed between paint colours, with chrome colours being associated with more vivid hallucinations. While both chrome and non-chrome users reported a comparable level of pleasure from paint sniffing, chrome paint users were more likely to be motivated by the potential to hallucinate. Our findings suggest that the type of inhalant used is an important consideration that may have relevance to clinical treatment.

Phenotypic, histological and proteomic analyses reveal multiple differences associated with chloroplast development in yellow and variegated variants from Camellia sinensis

PubMed Central

Ma, Chengying; Cao, Junxi; Li, Jianke; Zhou, Bo; Tang, Jinchi; Miao, Aiqing

2016-01-01

Leaf colour variation is observed in several plants. We obtained two types of branches with yellow and variegated leaves from Camellia sinensis. To reveal the mechanisms that underlie the leaf colour variations, combined morphological, histological, ionomic and proteomic analyses were performed using leaves from abnormal branches (variants) and normal branches (CKs). The measurement of the CIE-Lab coordinates showed that the brightness and yellowness of the variants were more intense than the CKs. When chloroplast profiles were analysed, HY1 (branch with yellow leaves) and HY2 (branch with variegated leaves) displayed abnormal chloroplast structures and a reduced number and size compared with the CKs, indicating that the abnormal chloroplast development might be tightly linked to the leaf colour variations. Moreover, the concentration of elemental minerals was different between the variants and the CKs. Furthermore, DEPs (differentially expressed proteins) were identified in the variants and the CKs by a quantitative proteomics analysis using the label-free approach. The DEPs were significantly involved in photosynthesis and included PSI, PSII, cytochrome b6/f complex, photosynthetic electron transport, LHC and F-type ATPase. Our results suggested that a decrease in the abundance of photosynthetic proteins might be associated with the changes of leaf colours in tea plants. PMID:27633059

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.

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

Biofouling of marbles by oxygenic photosynthetic microorganisms.

PubMed

Karaca, Zeki; Öztürk, Ayten; Çolak, Emel

2015-08-01

Phototrophic microorganisms disfigure the surfaces of different types of stone. Stone structure is damaged by the activity of photoautotrophic and other microorganisms. However, to date few, investigations have been undertaken into the relationship between microorganisms and the properties of different types of marble. In this study, biological activity of photoautotrophic microorganisms on three types of marble (Yatagan White, Giallo Anticato and Afyon White) was investigated under laboratory conditions over a short period of time. The three types of marble supported the growth of phototrophic microbial communities on their outer and inner layers, turning their original colour from white to a yellowish green colour. The porosity of the marble types facilitated filamentous microbial growth in the presence of water. Scanning electron microscope analysis revealed the accumulation of aggregates such as small spherical, fibrillar, calcified globular bodies on the inner surfaces of the marbles. This suggests that the microscopic characteristics of particular marble types may stimulate the growth of certain types of microorganisms.

Pollen Morphology of Caesalpinia pulcherrima (L.) Swartz in Highland and Lowland West Sumatra

NASA Astrophysics Data System (ADS)

Fitri, R.; Des, M.

2018-04-01

Determine the morphology structure of pollen on some variation colour of corolla Caesalpinia pulcherrima L. (Swartz) in highland and lowland West Sumatra has been conducted. The result reveals that topography and variation colour of corolla C. pulcherrima L. (Swartz) affects the shape of pollen. Pollen of C. pulcherrima L. (Swartz) has single grains or monad, isopolar polarity, radial symmetry, and size categories large. The length of polar axis (P) 58.16 to 74.11 μm, the length of the equatorial diameter (E) 59.86 to 75.97 μm, so that pollen can be classified into sub-spheroidal sub-oblate, spheriodal sub-spheroidal oblate, and sub-spheroidal prolate. Ornamentation of C. pulcherrima (L.) Swartz was reticulate. The pollen has aperture 3, the type pore and located in equatorial. From these data can be concluded that pollen from varying colour of corolla C. pulcherrima (L.) Swartz has same in terms of unit, polarity, symmetry, size, and type aperture, but it different in terms of shape.

Exaggeration and suppression of iridescence: the evolution of two-dimensional butterfly structural colours

PubMed Central

Wickham, Shelley; Large, Maryanne C.J; Poladian, Leon; Jermiin, Lars S

2005-01-01

Many butterfly species possess ‘structural’ colour, where colour is due to optical microstructures found in the wing scales. A number of such structures have been identified in butterfly scales, including three variations on a simple multi-layer structure. In this study, we optically characterize examples of all three types of multi-layer structure, as found in 10 species. The optical mechanism of the suppression and exaggeration of the angle-dependent optical properties (iridescence) of these structures is described. In addition, we consider the phylogeny of the butterflies, and are thus able to relate the optical properties of the structures to their evolutionary development. By applying two different types of analysis, the mechanism of adaptation is addressed. A simple parsimony analysis, in which all evolutionary changes are given an equal weighting, suggests convergent evolution of one structure. A Dollo parsimony analysis, in which the evolutionary ‘cost’ of losing a structure is less than that of gaining it, implies that ‘latent’ structures can be reused. PMID:16849221

Colour pairs for constraining the age and metallicity of stellar populations

NASA Astrophysics Data System (ADS)

Li, Zhongmu; Han, Zhanwen

2008-04-01

Using a widely used stellar-population synthesis model, we study the possibility of using pairs of AB system colours to break the well-known stellar age-metallicity degeneracy and to give constraints on two luminosity-weighted stellar-population parameters (age and metallicity). We present the relative age and metallicity sensitivities of the AB system colours that relate to the u,B,g,V,r,R,i, I,z,J,H and K bands, and we quantify the ability of various colour pairs to break the age-metallicity degeneracy. Our results suggest that a few pairs of colours can be used to constrain the above two stellar-population parameters. This will be very useful for exploring the stellar populations of distant galaxies. In detail, colour pairs [(r-K), (u-R)] and [(r-K), (u-r)] are shown to be the best pairs for estimating the luminosity-weighted stellar ages and metallicities of galaxies. They can constrain two stellar-population parameters on average with age uncertainties less than 3.89 Gyr and metallicity uncertainties less than 0.34 dex for typical colour uncertainties. The typical age uncertainties for young populations (age < 4.6 Gyr) and metal-rich populations (Z >= 0.001) are small (about 2.26 Gyr) while those for old populations (age >= 4.6 Gyr) and metal-poor populations (Z < 0.001) are much larger (about 6.88 Gyr). However, the metallicity uncertainties for metal-poor populations (about 0.0024) are much smaller than for other populations (about 0.015). Some other colour pairs can also possibly be used for constraining the two parameters. On the whole, the estimation of stellar-population parameters is likely to be reliable only for early-type galaxies with small colour errors and globular clusters, because such objects contain less dust. In fact, no galaxy is totally dust-free and early-type galaxies are also likely have some dust [e.g. E(B- V) ~ 0.05], which can change the stellar ages by about 2.5 Gyr and metallicities (Z) by about 0.015. When we compare the photometric estimates with previous spectroscopic estimates, we find some differences, especially when comparing the stellar ages determined by two methods. The differences mainly result from the young populations of galaxies. Therefore, it is difficult to obtain the absolute values of stellar ages and metallicities, but the results are useful for obtaining some relative values. In addition, our results suggest that colours relating to both UBVRIJHK and ugriz magnitudes are much better than either UBVRIJHK or ugriz colours for breaking the well-known degeneracy. The results also show that the stellar ages and metallicities of galaxies observed by the Sloan Digital Sky Survey and the Two-Micron All-Sky Survey can be estimated via photometry data. The data are available at the Centre de Données astronomiques de Strabourg (CDS) or on request to the authors. E-mail: zhongmu.li@gmail.com

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

Bees, birds and yellow flowers: pollinator-dependent convergent evolution of UV patterns.

PubMed

Papiorek, S; Junker, R R; Alves-Dos-Santos, I; Melo, G A R; Amaral-Neto, L P; Sazima, M; Wolowski, M; Freitas, L; Lunau, K

2016-01-01

Colour is one of the most obvious advertisements of flowers, and occurs in a huge diversity among the angiosperms. Flower colour is responsible for attraction from a distance, whereas contrasting colour patterns within flowers aid orientation of flower visitors after approaching the flowers. Due to the striking differences in colour vision systems and neural processing across animal taxa, flower colours evoke specific behavioural responses by different flower visitors. We tested whether and how yellow flowers differ in their spectral reflectance depending on the main pollinator. We focused on bees and birds and examined whether the presence or absence of the widespread UV reflectance pattern of yellow flowers predicts the main pollinator. Most bee-pollinated flowers displayed a pattern with UV-absorbing centres and UV-reflecting peripheries, whereas the majority of bird-pollinated flowers are entirely UV- absorbing. In choice experiments we found that bees did not show consistent preferences for any colour or pattern types. However, all tested bee species made their first antennal contact preferably at the UV-absorbing area of the artificial flower, irrespective of its spatial position within the flower. The appearance of UV patterns within flowers is the main difference in spectral reflectance between yellow bee- and bird-pollinated flowers, and affects the foraging behaviour of flower visitors. The results support the hypothesis that flower colours and the visual capabilities of their efficient pollinators are adapted to each other. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

Optical properties of zirconium oxynitride films: The effect of composition, electronic and crystalline structures

NASA Astrophysics Data System (ADS)

Carvalho, P.; Borges, J.; Rodrigues, M. S.; Barradas, N. P.; Alves, E.; Espinós, J. P.; González-Elipe, A. R.; Cunha, L.; Marques, L.; Vasilevskiy, M. I.; Vaz, F.

2015-12-01

This work is devoted to the investigation of zirconium oxynitride (ZrOxNy) films with varied optical responses prompted by the variations in their compositional and structural properties. The films were prepared by dc reactive magnetron sputtering of Zr, using Ar and a reactive gas mixture of N2 + O2 (17:3). The colour of the films changed from metallic-like, very bright yellow-pale and golden yellow, for low gas flows to red-brownish for intermediate gas flows. Associated to this colour change there was a significant decrease of brightness. With further increase of the reactive gas flow, the colour of the samples changed from red-brownish to dark blue or even to interference colourations. The variations in composition disclosed the existence of four different zones, which were found to be closely related with the variations in the crystalline structure. XRD analysis revealed the change from a B1 NaCl face-centred cubic zirconium nitride-type phase for films prepared with low reactive gas flows, towards a poorly crystallized over-stoichiometric nitride phase, which may be similar to that of Zr3N4 with some probable oxygen inclusions within nitrogen positions, for films prepared with intermediate reactive gas flows. For high reactive gas flows, the films developed an oxynitride-type phase, similar to that of γ-Zr2ON2 with some oxygen atoms occupying some of the nitrogen positions, evolving to a ZrO2 monoclinic type structure within the zone where films were prepared with relatively high reactive gas flows. The analysis carried out by reflected electron energy loss spectroscopy (REELS) revealed a continuous depopulation of the d-band and an opening of an energy gap between the valence band (2p) and the Fermi level close to 5 eV. The ZrN-based coatings (zone I and II) presented intrinsic colourations, with a decrease in brightness and a colour change from bright yellow to golden yellow, red brownish and dark blue. Associated to these changes, there was also a shift of the reflectivity minimum to lower energies, with the increase of the non-metallic content. The samples lying in the two last zones (zone III, oxynitride and zone IV, oxide films) revealed a typical semi-transparent-optical behaviour showing interference-like colourations only due to the complete depopulation of the d band at the Fermi level. The samples lying in these zones presented also an increase of the optical bandgap from 2 to 3.6 eV.

Light quality and temperature effects on antirrhinum growth and development

PubMed Central

Khattak, Abdul Mateen; Pearson, Simon

2005-01-01

An experiment was carried out to examine the effects of light quality on the growth and development of antirrhinum under three different temperatures 19 °C, 24 °C and 27 °C in glasshouses. Five different colour filters (i.e. ‘Red absorbing’, ‘Blue absorbing’, ‘Blue and Red absorbing’ and two ‘partially Blue absorbing’ materials) were tested, with one clear polythene as a control. Plant height, internode length and leaf area were significantly affected by the spectral filters as well as the temperature. Analysis of color filter’s effect on presumed photoreceptors to exist indicated that antirrhinum plant height was regulated by the action of a blue acting photoreceptor (BAP) and not the phytochrome. There was no evidence for an effect of phytochrome or BAP on time to flowering, however, increasing temperature levels effectively decreased the time to flowering. To predict the effects of different spectral qualities and temperature, simple models were created from data on plant height, internode length and time to flowering. These models were then applied to simulate the potential benefits of spectral filters and temperature in manipulation of growth control and flowering in antirrhinum. PMID:15633247

The feasibility of using a universal Random Forest model to map tree height across different locations and vegetation types

NASA Astrophysics Data System (ADS)

Su, Y.; Guo, Q.; Jin, S.; Gao, S.; Hu, T.; Liu, J.; Xue, B. L.

2017-12-01

Tree height is an important forest structure parameter for understanding forest ecosystem and improving the accuracy of global carbon stock quantification. Light detection and ranging (LiDAR) can provide accurate tree height measurements, but its use in large-scale tree height mapping is limited by the spatial availability. Random Forest (RF) has been one of the most commonly used algorithms for mapping large-scale tree height through the fusion of LiDAR and other remotely sensed datasets. However, how the variances in vegetation types, geolocations and spatial scales of different study sites influence the RF results is still a question that needs to be addressed. In this study, we selected 16 study sites across four vegetation types in United States (U.S.) fully covered by airborne LiDAR data, and the area of each site was 100 km2. The LiDAR-derived canopy height models (CHMs) were used as the ground truth to train the RF algorithm to predict canopy height from other remotely sensed variables, such as Landsat TM imagery, terrain information and climate surfaces. To address the abovementioned question, 22 models were run under different combinations of vegetation types, geolocations and spatial scales. The results show that the RF model trained at one specific location or vegetation type cannot be used to predict tree height in other locations or vegetation types. However, by training the RF model using samples from all locations and vegetation types, a universal model can be achieved for predicting canopy height across different locations and vegetation types. Moreover, the number of training samples and the targeted spatial resolution of the canopy height product have noticeable influence on the RF prediction accuracy.

An Ammeter That Indicates Electric Current by the Movement of a Light Spot, and Voltage by the Colour

ERIC Educational Resources Information Center

Kamata, Masahiro; Hara, Chiho

2005-01-01

A new type of ammeter (PikoPikoII) has been developed which indicates the measured current by the movement of a spot of light and the voltage by the colour of the spot. Since this tool can make students feel as if they are observing a visual image of electricity, it is easy to prepare schematic explanations on electric circuits that match the…

The Effect of the Type and Colour of Placebo Stimuli on Placebo Effects Induced by Observational Learning.

PubMed

Świder, Karolina; Bąbel, Przemysław

2016-01-01

Research shows that placebo analgesia and nocebo hyperalgesia can be induced through observational learning. Our aim was to replicate and extend these results by studying the influence of the type and colour of stimuli used as placebos on the placebo effects induced by observational learning. Three experimental and two control groups were tested. All participants received pain stimuli of the same intensity preceded by colour lights (green and red) or geometric shapes (circles and squares). Before receiving pain stimuli, participants in the experimental groups, but not in the control groups, observed a model who rated pain stimuli that were preceded by either green lights (green placebo group), red lights (red placebo group), or circles (circle placebo group) as being less painful than those preceded by either red lights (green placebo group), green lights (red placebo group), or squares (circle placebo group). As a result participants in the experimental groups rated pain stimuli preceded by either green lights (green placebo group), red lights (red placebo group), or circles (circle placebo group) as being less painful than the participants in the control groups did, indicating that placebo effect was induced. No statistically significant differences were found in the magnitudes of the placebo effects between the three experimental groups (green placebo, red placebo, and circle placebo groups), indicating that neither the type nor the colour of placebo stimuli affected the placebo effects induced by observational learning. The placebo effects induced by observational learning were found to be unrelated to the individual differences in pain anxiety, fear of pain, and empathy.

The Effect of the Type and Colour of Placebo Stimuli on Placebo Effects Induced by Observational Learning

PubMed Central

Świder, Karolina; Bąbel, Przemysław

2016-01-01

Research shows that placebo analgesia and nocebo hyperalgesia can be induced through observational learning. Our aim was to replicate and extend these results by studying the influence of the type and colour of stimuli used as placebos on the placebo effects induced by observational learning. Three experimental and two control groups were tested. All participants received pain stimuli of the same intensity preceded by colour lights (green and red) or geometric shapes (circles and squares). Before receiving pain stimuli, participants in the experimental groups, but not in the control groups, observed a model who rated pain stimuli that were preceded by either green lights (green placebo group), red lights (red placebo group), or circles (circle placebo group) as being less painful than those preceded by either red lights (green placebo group), green lights (red placebo group), or squares (circle placebo group). As a result participants in the experimental groups rated pain stimuli preceded by either green lights (green placebo group), red lights (red placebo group), or circles (circle placebo group) as being less painful than the participants in the control groups did, indicating that placebo effect was induced. No statistically significant differences were found in the magnitudes of the placebo effects between the three experimental groups (green placebo, red placebo, and circle placebo groups), indicating that neither the type nor the colour of placebo stimuli affected the placebo effects induced by observational learning. The placebo effects induced by observational learning were found to be unrelated to the individual differences in pain anxiety, fear of pain, and empathy. PMID:27362552

Functional specialization and generalization for grouping of stimuli based on colour and motion

PubMed Central

Zeki, Semir; Stutters, Jonathan

2013-01-01

This study was undertaken to learn whether the principle of functional specialization that is evident at the level of the prestriate visual cortex extends to areas that are involved in grouping visual stimuli according to attribute, and specifically according to colour and motion. Subjects viewed, in an fMRI scanner, visual stimuli composed of moving dots, which could be either coloured or achromatic; in some stimuli the moving coloured dots were randomly distributed or moved in random directions; in others, some of the moving dots were grouped together according to colour or to direction of motion, with the number of groupings varying from 1 to 3. Increased activation was observed in area V4 in response to colour grouping and in V5 in response to motion grouping while both groupings led to activity in separate though contiguous compartments within the intraparietal cortex. The activity in all the above areas was parametrically related to the number of groupings, as was the prominent activity in Crus I of the cerebellum where the activity resulting from the two types of grouping overlapped. This suggests (a) that, the specialized visual areas of the prestriate cortex have functions beyond the processing of visual signals according to attribute, namely that of grouping signals according to colour (V4) or motion (V5); (b) that the functional separation evident in visual cortical areas devoted to motion and colour, respectively, is maintained at the level of parietal cortex, at least as far as grouping according to attribute is concerned; and (c) that, by contrast, this grouping-related functional segregation is not maintained at the level of the cerebellum. PMID:23415950

Physiological and haematological indices suggest superior heat tolerance of white-coloured West African Dwarf sheep in the hot humid tropics.

PubMed

Fadare, Adelodun O; Peters, Sunday O; Yakubu, Abdulmojeed; Sonibare, Adekayode O; Adeleke, Matthew A; Ozoje, Michael O; Imumorin, Ikhide G

2013-01-01

Coat colour contributes to physiological adaptation in mammals and mediates response to thermal stress. Twenty-four adult West African Dwarf sheep of both sexes and with different coat colour types were used in this study. We measured rectal temperature (RT), respiratory rate (RR) and pulse rate (PR) before sunrise and sunset during the late dry season (January-March) and early rainy season (April-June) as well as packed cell volume (PCV), red blood cell (RBC) count, white blood cell (WBC) count, plasma sodium (Na(+)) and potassium (K(+)). Animals with black coat colour had the highest (P < 0.05) mean values of 38.92 ± 0.03 °C, 65.09 ± 1.06 breaths/min, 81.35 ± 0.78 beats/min, 1.70 ± 0.01 for RT, RR, PR and heat stress index (HSI), respectively, followed by brown mouflon and brown with extensive white, while the Badger Face coloured sheep had the least mean values. There were significant (P < 0.05) differences between male and female sheep for RT, RR, PR and HSI. Season had a significant (P < 0.05) effect on RT, RR, PR and HSI. Coat colour and sex also significantly (P < 0.01) affected RBC, WBC, Na(+) and K(+). Seasonal variation (P < 0.05) in all the blood parameters was observed, with the exception of PCV. Interaction effect of coat colour and sex was significant (P < 0.05) on RT and HSI. Correlation coefficients among the measured traits ranged from positive to negative values. These results indicate that selection of white-coloured sheep to attenuate heat stress is desirable in the hot humid tropics.

The use of body mass changes as a practical measure of dehydration in team sports.

PubMed

Harvey, Gemma; Meir, Rudi; Brooks, Lyndon; Holloway, Kate

2008-11-01

Body mass changes, hematocrit, specific gravity and urine colour were recorded during two games of soccer to determine which of these methods was the most practical in a field setting for monitoring dehydration. Members (n=13) of a premiership soccer team with a mean age of 22.6 (+/-4.9) years old, height of 177.8 (+/-7.1)cm and sum of skinfolds (four sites) of 37 (+/-12.8) were invited to participate in this study with 11 participating in each game. Players had weight, hematocrit, specific gravity and urine colour recorded pre- and post-game. Players were allowed to ingest fluid ad libitum throughout the matches with the amount consumed recorded. Urine excretion was also recorded and included in the calculation of final body mass loss (kg). A mean ambient temperature of 21 degrees C and relative humidity 77% was recorded for both games. Pre- and post-game body mass, sweat loss, hematocrit, urine specific gravity and colour were significantly different (p<0.01) for both games. Linear mixed effects models were fitted to the data in order to identify an optimal prediction equation for sweat loss. The model predicting from mass change was clearly the best fitting. The results demonstrate that a change in body mass during a game of soccer is an effective method of monitoring dehydration due to sweat loss when compared to other known methods that may be invasive and inappropriate in the field.

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.

Effects of hair sprays on colour perception: a hyperspectral imaging approach to shine and chroma on heads.

PubMed

Puccetti, G; Thompson, W

2017-04-01

Hair sprays apply fixative ingredients to provide hold to a hair style as well as weather resistance and optical properties such as shine. Generally, sprays distribute fine particles containing polymeric ingredients to form a thin film on the surface of hair. Different hair types require different strengths of the formed deposit on the hair surface. The present study shows how sprays also alter the visibility of the hair colour by altering the surface topology of the hair fibres. Hyperspectral imaging is used to map spectral characteristics of hair on mannequins and panelists over the curvature of heads. Spectral and spatial characteristics are measured before and after hair spray applications. The hair surface is imaged by SEM to visualize the degree of cuticle coverage. Finally, the perception of hair colour was evaluated on red-coloured mannequins by consumer questionnaire. Hair sprays deposit different degrees of fixatives, which lead to a progressive leveling of the cuticle natural tilt angle with respect to the fibre axis. As a result, shine is progressively shifting towards the region of hair colour visibility and decreases the perceived colour of hair seen by consumers. Lighter sprays show thinner film formation on the hair surface and less of a shine shift than strong hold hair sprays. Hair sprays are generally employed for hair style hold and weather resistance and considered without effect on hair colour. Our approach shows that spray-deposited films can affect colour perception by altering the microstructure of the hair surface. Thin films deposited on the hair fibre surface can partially fill gaps between cuticles, which reduces the cuticle natural angle. This partial erasure results in a angle shift of the shine regions towards the angle of internal reflection, thus decreasing the perceived hair colour regions as experienced by a group of consumers. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

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.

Analysis of Visual Interpretation of Satellite Data

NASA Astrophysics Data System (ADS)

Svatonova, H.

2016-06-01

Millions of people of all ages and expertise are using satellite and aerial data as an important input for their work in many different fields. Satellite data are also gradually finding a new place in education, especially in the fields of geography and in environmental issues. The article presents the results of an extensive research in the area of visual interpretation of image data carried out in the years 2013 - 2015 in the Czech Republic. The research was aimed at comparing the success rate of the interpretation of satellite data in relation to a) the substrates (to the selected colourfulness, the type of depicted landscape or special elements in the landscape) and b) to selected characteristics of users (expertise, gender, age). The results of the research showed that (1) false colour images have a slightly higher percentage of successful interpretation than natural colour images, (2) colourfulness of an element expected or rehearsed by the user (regardless of the real natural colour) increases the success rate of identifying the element (3) experts are faster in interpreting visual data than non-experts, with the same degree of accuracy of solving the task, and (4) men and women are equally successful in the interpretation of visual image data.

Visual modelling suggests a weak relationship between the evolution of ultraviolet vision and plumage coloration in birds.

PubMed

Lind, O; Delhey, K

2015-03-01

Birds have sophisticated colour vision mediated by four cone types that cover a wide visual spectrum including ultraviolet (UV) wavelengths. Many birds have modest UV sensitivity provided by violet-sensitive (VS) cones with sensitivity maxima between 400 and 425 nm. However, some birds have evolved higher UV sensitivity and a larger visual spectrum given by UV-sensitive (UVS) cones maximally sensitive at 360-370 nm. The reasons for VS-UVS transitions and their relationship to visual ecology remain unclear. It has been hypothesized that the evolution of UVS-cone vision is linked to plumage colours so that visual sensitivity and feather coloration are 'matched'. This leads to the specific prediction that UVS-cone vision enhances the discrimination of plumage colours of UVS birds while such an advantage is absent or less pronounced for VS-bird coloration. We test this hypothesis using knowledge of the complex distribution of UVS cones among birds combined with mathematical modelling of colour discrimination during different viewing conditions. We find no support for the hypothesis, which, combined with previous studies, suggests only a weak relationship between UVS-cone vision and plumage colour evolution. Instead, we suggest that UVS-cone vision generally favours colour discrimination, which creates a nonspecific selection pressure for the evolution of UVS cones. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Optimized two- and three-colour laser pulses for the intense terahertz wave generation

NASA Astrophysics Data System (ADS)

Zhang, Lei; Wang, Guo-Li; Zhou, Xiao-Xin

2016-11-01

Based on the photocurrent model, we perform a theoretical study on the optimization of terahertz (THz) wave emission from argon gas irradiated by the two- and three-colour laser fields. To obtain stronger THz radiation for the given conditions, a genetic algorithm method is applied to search for the optimum laser parameters. For the two-colour field, our optimizations reveal two types of optimal scheme, and each one dominates the THz generation in different regions of intensity ratio for a given total laser intensity. One scheme is the combination of a fundamental laser pulse and its second harmonic, while the other is the fundamental pulse with its fourth harmonic. For each scheme, the optimal intensity ratio and phase delay are obtained. For the three-colour case, our optimization shows that the excellent waveform for the strongest THz radiation is composed of a fundamental laser pulse, and its second, third harmonics, with appropriate intensity ratio and carrier-envelope phase. Such a 3-colour field can generate strong THz radiation comparable with a 10-colour sawtooth wave [Martínez et al., Phys. Rev. Lett. 114, 183901 (2015)]. The physical mechanisms for the enhancement of THz wave emission in gases are also discussed in detail. Our results give helpful guidance for intense THz generation with tabletop femtosecond laser device in experiment.

A standard stellar library for evolutionary synthesis. III. Metallicity calibration

NASA Astrophysics Data System (ADS)

Westera, P.; Lejeune, T.; Buser, R.; Cuisinier, F.; Bruzual, G.

2002-01-01

We extend the colour calibration of the widely used BaSeL standard stellar library (Lejeune et al. 1997, 1998) to non-solar metallicities, down to [Fe/H] ~ -2.0 dex. Surprisingly, we find that at the present epoch it is virtually impossible to establish a unique calibration of UBVRIJHKL colours in terms of stellar metallicity [Fe/H] which is consistent simultaneously with both colour-temperature relations and colour-absolute magnitude diagrams (CMDs) based on observed globular cluster photometry data and on published, currently popular standard stellar evolutionary tracks and isochrones. The problem appears to be related to the long-standing incompleteness in our understanding of convection in late-type stellar evolution, but is also due to a serious lack of relevant observational calibration data that would help resolve, or at least further significant progress towards resolving this issue. In view of the most important applications of the BaSeL library, we here propose two different metallicity calibration versions: (1) the ``WLBC 99'' library, which consistently matches empirical colour-temperature relations and which, therefore, should make an ideal tool for the study of individual stars; and (2), the ``PADOVA 2000'' library, which provides isochrones from the Padova 2000 grid (Girardi et al. \\cite{padova}) that successfully reproduce Galactic globular-cluster colour-absolute magnitude diagrams and which thus should prove particularly useful for studies of collective phenomena in stellar populations in clusters and galaxies.

Non-binary Colour Modulation for Display Device Based on Phase Change Materials.

PubMed

Ji, Hong-Kai; Tong, Hao; Qian, Hang; Hui, Ya-Juan; Liu, Nian; Yan, Peng; Miao, Xiang-Shui

2016-12-19

A reflective-type display device based on phase change materials is attractive because of its ultrafast response time and high resolution compared with a conventional display device. This paper proposes and demonstrates a unique display device in which multicolour changing can be achieved on a single device by the selective crystallization of double layer phase change materials. The optical contrast is optimized by the availability of a variety of film thicknesses of two phase change layers. The device exhibits a low sensitivity to the angle of incidence, which is important for display and colour consistency. The non-binary colour rendering on a single device is demonstrated for the first time using optical excitation. The device shows the potential for ultrafast display applications.

Influence of carbon monoxide on the colour stability of defrosted yellowfin tuna (Thunnus albacares) muscle stored under aerobic and anaerobic conditions.

PubMed

Neethling, Nikki E; Hoffman, Louwrens C; Britz, Trevor J; O'Neill, Bernadette

2015-06-01

The use of carbon monoxide (CO) and various packaging types has been suggested to improve/stabilise the colour and oxidative processes of red meats, thereby improving the retail value and revenue. The main aim of this study was to investigate the influence of packaging type and CO treatment on the colour and oxidative stability of tuna. The addition of CO significantly increased the redness (a(*) ) of the tuna steaks but the redness was not equally stable for all treatments. The aerobically packaged steaks showed a temporal decrease in redness while the redness of anaerobically packaged steaks remained relatively stable. The addition of CO did not significantly affect (P >0.05) the brownness (b(*) ) (with one exception) and lightness (L(*) ) of the steaks. The anaerobically packaged steaks showed a significant difference (P <0.05) in the b(*) values. No significant differences (P >0.05) in lipid or protein oxidation were observed between treatments. The aerobically packaged steaks had a significant temporal increase (P <0.05) in lipid oxidation while no such trend was apparent in the anaerobically packaged steaks. Protein oxidation remained relatively stable over time for both aerobically and anaerobically packaged steaks. Storing CO treated tuna steaks in anaerobic packaging can improve the oxidative and colour stability of tuna. Such treatment can reduce spoilage and wastage thereby potentially increasing revenue. © 2014 Society of Chemical Industry.

The influence of inherited plumage colour morph on morphometric traits and breeding investment in zebra finches (Taeniopygia guttata).

PubMed

Krause, E Tobias; Krüger, Oliver; Hoffman, Joseph I

2017-01-01

Melanin-based plumage polymorphism occurs in many wild bird populations and has been linked to fitness variation in several species. These fitness differences often arise as a consequence of variation in traits such as behaviour, immune responsiveness, body size and reproductive investment. However, few studies have controlled for genetic differences between colour morphs that could potentially generate artefactual associations between plumage colouration and trait variation. Here, we used zebra finches (Taeniopygia guttata) as a model system in order to evaluate whether life-history traits such as adult body condition and reproductive investment could be influenced by plumage morph. To maximise any potential differences, we selected wild-type and white plumage morphs, which differ maximally in their extent of melanisation, while using a controlled three-generation breeding design to homogenise the genetic background. We found that F2 adults with white plumage colouration were on average lighter and had poorer body condition than wild-type F2 birds. However, they appeared to compensate for this by reproducing earlier and producing heavier eggs relative to their own body mass. Our study thus reveals differences in morphological and life history traits that could be relevant to fitness variation, although further studies will be required to evaluate fitness effects under natural conditions as well as to characterise any potential fitness costs of compensatory strategies in white zebra finches.

Standardizing Type Ia supernovae optical brightness using near-infrared rebrightening time

NASA Astrophysics Data System (ADS)

Shariff, H.; Dhawan, S.; Jiao, X.; Leibundgut, B.; Trotta, R.; van Dyk, D. A.

2016-12-01

Accurate standardization of Type Ia supernovae (SNIa) is instrumental to the usage of SNIa as distance indicators. We analyse a homogeneous sample of 22 low-z SNIa, observed by the Carnegie Supernova Project in the optical and near-infrared (NIR). We study the time of the second peak in the J band, t2, as an alternative standardization parameter of SNIa peak optical brightness, as measured by the standard SALT2 parameter mB. We use BAHAMAS, a Bayesian hierarchical model for SNIa cosmology, to estimate the residual scatter in the Hubble diagram. We find that in the absence of a colour correction, t2 is a better standardization parameter compared to stretch: t2 has a 1σ posterior interval for the Hubble residual scatter of σΔμ = {0.250, 0.257} mag, compared to σΔμ = {0.280, 0.287} mag when stretch (x1) alone is used. We demonstrate that when employed together with a colour correction, t2 and stretch lead to similar residual scatter. Using colour, stretch and t2 jointly as standardization parameters does not result in any further reduction in scatter, suggesting that t2 carries redundant information with respect to stretch and colour. With a much larger SNIa NIR sample at higher redshift in the future, t2 could be a useful quantity to perform robustness checks of the standardization procedure.

The influence of inherited plumage colour morph on morphometric traits and breeding investment in zebra finches (Taeniopygia guttata)

PubMed Central

Krüger, Oliver

2017-01-01

Melanin-based plumage polymorphism occurs in many wild bird populations and has been linked to fitness variation in several species. These fitness differences often arise as a consequence of variation in traits such as behaviour, immune responsiveness, body size and reproductive investment. However, few studies have controlled for genetic differences between colour morphs that could potentially generate artefactual associations between plumage colouration and trait variation. Here, we used zebra finches (Taeniopygia guttata) as a model system in order to evaluate whether life-history traits such as adult body condition and reproductive investment could be influenced by plumage morph. To maximise any potential differences, we selected wild-type and white plumage morphs, which differ maximally in their extent of melanisation, while using a controlled three-generation breeding design to homogenise the genetic background. We found that F2 adults with white plumage colouration were on average lighter and had poorer body condition than wild-type F2 birds. However, they appeared to compensate for this by reproducing earlier and producing heavier eggs relative to their own body mass. Our study thus reveals differences in morphological and life history traits that could be relevant to fitness variation, although further studies will be required to evaluate fitness effects under natural conditions as well as to characterise any potential fitness costs of compensatory strategies in white zebra finches. PMID:29190647

A multicolour graph as a complete topological invariant for \\Omega-stable flows without periodic trajectories on surfaces

NASA Astrophysics Data System (ADS)

Kruglov, V. E.; Malyshev, D. S.; Pochinka, O. V.

2018-01-01

Studying the dynamics of a flow on surfaces by partitioning the phase space into cells with the same limit behaviour of trajectories within a cell goes back to the classical papers of Andronov, Pontryagin, Leontovich and Maier. The types of cells (the number of which is finite) and how the cells adjoin one another completely determine the topological equivalence class of a flow with finitely many special trajectories. If one trajectory is chosen in every cell of a rough flow without periodic orbits, then the cells are partitioned into so-called triangular regions of the same type. A combinatorial description of such a partition gives rise to the three-colour Oshemkov-Sharko graph, the vertices of which correspond to the triangular regions, and the edges to separatrices connecting them. Oshemkov and Sharko proved that such flows are topologically equivalent if and only if the three-colour graphs of the flows are isomorphic, and described an algorithm of distinguishing three-colour graphs. But their algorithm is not efficient with respect to graph theory. In the present paper, we describe the dynamics of Ω-stable flows without periodic trajectories on surfaces in the language of four-colour graphs, present an efficient algorithm for distinguishing such graphs, and develop a realization of a flow from some abstract graph. Bibliography: 17 titles.

The physiological and phenotypic determinants of human tanning measured as change in skin colour following a single dose of ultraviolet B radiation.

PubMed

Wong, Terence H; Jackson, Ian J; Rees, Jonathan L

2010-07-01

Experimental study of the in vivo kinetics of tanning in human skin has been limited by the difficulties in measuring changes in melanin pigmentation independent of the ultravioletinduced changes in erythema. The present study attempted to experimentally circumvent this issue. We have studied erythemal and tanning responses following a single exposure to a range of doses of ultraviolet B irradiation on the buttock and the lower back in 98 subjects. Erythema was assessed using reflectance techniques at 24 h and tanning measured as the L* spectrophotometric score at 7 days following noradrenaline iontophoresis. We show that dose (P < 0.0001), body site (P < 0.0001), skin colour (P < 0.0001), ancestry (P = 0.0074), phototype (P = 0.0019) and sex (P = 0.04) are all independent predictors of erythema. Quantitative estimates of the effects of these variables are reported, but the effects of ancestry and phototype do not appear solely explainable in terms of L* score. Dose (P < 0.0001), body site (P < 0.0001) and skin colour (P = 0.0365) or, as an alternative to skin colour, skin type (P = 0.0193) predict tanning, with those with lighter skin tanning slightly more to a defined UVB dose. If erythema is factored into the regression, then only dose and body site remain significant predictors of tanning: therefore neither phototype nor pigmentary factors, such as baseline skin colour, or eye or hair colour, predict change in skin colour to a unit erythemal response.

Iridescence: views from many angles

PubMed Central

Meadows, Melissa G.; Butler, Michael W.; Morehouse, Nathan I.; Taylor, Lisa A.; Toomey, Matthew B.; McGraw, Kevin J.; Rutowski, Ronald L.

2009-01-01

Iridescent colours have been fascinating to humans throughout history; they are flashy, shimmering, dynamic, and examples surround us, from the commonly seen iridescent sheen of oily street puddles to the exotic, gaudy displays of birds-of-paradise featured in nature documentaries. Iridescent colours and the structures that produce them have unique properties in comparison with other types of colourants found in nature. Scientists from a variety of disciplines study the optics, development, heritability, chemical make-up, origin, evolution, functions and biomimetic technological applications of naturally occurring iridescent colours. For the first time, graduate students at Arizona State University brought together these scientists, along with educators and artists, at ‘Iridescence: more than meets the eye’, a conference to promote interdisciplinary communication and collaboration in the study of iridescent coloration from all of these perspectives. Here, we summarize the outcomes of this conference, introduce the papers that follow in this special journal issue and briefly review the current status of our understanding of iridescence. PMID:19336343

Colour centre recovery in yttria-stabilised zirconia: photo-induced versus thermal processes

NASA Astrophysics Data System (ADS)

Costantini, Jean-Marc; Touati, Nadia; Binet, Laurent; Lelong, Gérald; Guillaumet, Maxime; Beuneu, François

2018-05-01

The photo-annealing of colour centres in yttria-stabilised zirconia (YSZ) was studied by electron paramagnetic resonance spectroscopy upon UV-ray or laser light illumination, and compared to thermal annealing. Stable hole centres (HCs) were produced in as-grown YSZ single crystals by UV-ray irradiation at room temperature (RT). The HCs produced by 200-MeV Au ion irradiation, as well as the F+-type centres (? centres involving oxygen vacancies) were left unchanged upon UV illumination. In contrast, a significant photo-annealing of the latter point defects was achieved in 1.4-MeV electron-irradiated YSZ by 553-nm laser light irradiation at RT. Almost complete photo-bleaching was achieved by laser irradiation inside the absorption band of ? centres centred at a wavelength 550 nm. Thermal annealing of these colour centres was also followed by UV-visible absorption spectroscopy showing full bleaching at 523 K. Colour-centre evolutions by photo-induced and thermally activated processes are discussed on the basis of charge exchange processes between point defects.

A feed-forward Hopfield neural network algorithm (FHNNA) with a colour satellite image for water quality mapping

NASA Astrophysics Data System (ADS)

Asal Kzar, Ahmed; Mat Jafri, M. Z.; Hwee San, Lim; Al-Zuky, Ali A.; Mutter, Kussay N.; Hassan Al-Saleh, Anwar

2016-06-01

There are many techniques that have been given for water quality problem, but the remote sensing techniques have proven their success, especially when the artificial neural networks are used as mathematical models with these techniques. Hopfield neural network is one type of artificial neural networks which is common, fast, simple, and efficient, but it when it deals with images that have more than two colours such as remote sensing images. This work has attempted to solve this problem via modifying the network that deals with colour remote sensing images for water quality mapping. A Feed-forward Hopfield Neural Network Algorithm (FHNNA) was modified and used with a satellite colour image from type of Thailand earth observation system (THEOS) for TSS mapping in the Penang strait, Malaysia, through the classification of TSS concentrations. The new algorithm is based essentially on three modifications: using HNN as feed-forward network, considering the weights of bitplanes, and non-self-architecture or zero diagonal of weight matrix, in addition, it depends on a validation data. The achieved map was colour-coded for visual interpretation. The efficiency of the new algorithm has found out by the higher correlation coefficient (R=0.979) and the lower root mean square error (RMSE=4.301) between the validation data that were divided into two groups. One used for the algorithm and the other used for validating the results. The comparison was with the minimum distance classifier. Therefore, TSS mapping of polluted water in Penang strait, Malaysia, can be performed using FHNNA with remote sensing technique (THEOS). It is a new and useful application of HNN, so it is a new model with remote sensing techniques for water quality mapping which is considered important environmental problem.

Structure and optical function of amorphous photonic nanostructures from avian feather barbs: a comparative small angle X-ray scattering (SAXS) analysis of 230 bird species

PubMed Central

Saranathan, Vinodkumar; Forster, Jason D.; Noh, Heeso; Liew, Seng-Fatt; Mochrie, Simon G. J.; Cao, Hui; Dufresne, Eric R.; Prum, Richard O.

2012-01-01

Non-iridescent structural colours of feathers are a diverse and an important part of the phenotype of many birds. These colours are generally produced by three-dimensional, amorphous (or quasi-ordered) spongy β-keratin and air nanostructures found in the medullary cells of feather barbs. Two main classes of three-dimensional barb nanostructures are known, characterized by a tortuous network of air channels or a close packing of spheroidal air cavities. Using synchrotron small angle X-ray scattering (SAXS) and optical spectrophotometry, we characterized the nanostructure and optical function of 297 distinctly coloured feathers from 230 species belonging to 163 genera in 51 avian families. The SAXS data provided quantitative diagnoses of the channel- and sphere-type nanostructures, and confirmed the presence of a predominant, isotropic length scale of variation in refractive index that produces strong reinforcement of a narrow band of scattered wavelengths. The SAXS structural data identified a new class of rudimentary or weakly nanostructured feathers responsible for slate-grey, and blue-grey structural colours. SAXS structural data provided good predictions of the single-scattering peak of the optical reflectance of the feathers. The SAXS structural measurements of channel- and sphere-type nanostructures are also similar to experimental scattering data from synthetic soft matter systems that self-assemble by phase separation. These results further support the hypothesis that colour-producing protein and air nanostructures in feather barbs are probably self-assembled by arrested phase separation of polymerizing β-keratin from the cytoplasm of medullary cells. Such avian amorphous photonic nanostructures with isotropic optical properties may provide biomimetic inspiration for photonic technology. PMID:22572026

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.

Evaluation of the Indonesian National Standard for elementary school furniture based on children's anthropometry.

PubMed

Yanto; Lu, Chih-Wei; Lu, Jun-Ming

2017-07-01

In Indonesia, National Standardization Agency of Indonesia issued the Indonesian National Standard SNI 12-1015-1989 and SNI 12-1016-1989 to define the type of furniture dimensions that should be used by children in the elementary school level. This study aims to examine whether the current national standards for elementary school furniture dimensions issued by National Standardization Agency of Indonesia match the up-to-date Indonesian children's anthropometry. Two types of school furniture, small type (Type I, for grade 1-3) and large type (Type II, for grade 4-6), were evaluated in terms of seat height, seat depth, seat width and backrest height of a chair as well as the height and underneath height of a desk. 1146 students aged between 6 and 12 years old participated in the study. Seven anthropometric measurements were taken including stature, sitting shoulder height, sitting elbow height, popliteal height, buttock-popliteal length, knee height and hip breadth. Based on the standard school furniture dimensions and students' body dimensions, numbers of matches and mismatches between them were computed. Results indicated a substantial degree of mismatch between children's anthropometry and the standard dimensions of school furniture. The standard seat height was not appropriate for students among different grades with the mismatch percentage ranging from 63.4% to 96.7% for Type I and 72.7% to 99.0% for Type II. For desk height, the standard dimensions were not appropriate for students among different grades with the mismatch percentage ranging from 32.3% to 88.9% for Type I and 67.7% to 99.0% for Type II. Apparently, the current standards are out of date and need to be updated. Four different sizes of school furniture were hence proposed to accommodate the variation in students' anthropometry from Grade 1 to Grade 6. The proposed standard dimensions (PrS) of school furniture cover a slightly broader range of age and present a higher cumulative fit than the current standard dimensions (CrS). In addition, a better strategy for sizing can be also developed to fit chairs and desks to a larger number of students. Copyright © 2017 Elsevier Ltd. All rights reserved.

A formula for evaluating colour differences for thread sewn into fabric samples

NASA Astrophysics Data System (ADS)

Steder, Thorsten

In-service rails can develop several types of structural defects due to fatigue and wear caused by rolling stock passing over them. Most rail defects will develop gradually over time thus permitting inspection engineers to detect them in time before final failure occurs. In the UK, certain types of severe rail defects such as tache ovales, require the fitting of emergency clamps and the imposing of an Emergency Speed Restriction (ESR) until the defects are removed. Acoustic emission (AE) techniques can be applied for the detection and continuous monitoring of defect growth therefore removing the need of imposing strict ESRs. The work reported herewith aims to develop a sound methodology for the application of AE in order to detect and subsequently monitor damage evolution in rails. To validate the potential of the AE technique, tests have been carried out under laboratory conditions on three and four-point bending samples manufactured from 260 grade rail steel. Further tests, simulating the background noise conditions caused by passing rolling stock have been carried out using special experimental setups. The crack growth events have been simulated using a pencil tip break..

Lipid and colour stability of Milano-type sausages: effect of packing conditions.

PubMed

Zanardi, E; Dorigoni, V; Badiani, A; Chizzolini, R

2002-05-01

Lipid and colour oxidative changes in Milano-type fermented sausages were studied in relation to packing conditions and extended storage under fluorescent light. Matured sausages were sliced and packed under vacuum or in protective atmosphere (100% N(2)) and exposed in a display cabinet to mimic commercial conditions of light and temperature for 2 months. Lipid oxidation was measured by the determination of thiobarbituric acid reactive substances (TBARS) and cholesterol oxidation products (COP), whereas the oxidation of nitrosylmyoglobin was evaluated by a trained sensory panel. Lipid oxidation and discolouration were positively related in vacuum-packed sausages: TBARS and COP values increased significantly concurrently with increasing brown scores. Protective atmosphere came out to be more efficient than vacuum in controlling fatty acid oxidation and, to a lesser extent, cholesterol and pigment degradation: TBARS values remained constant during the whole storage period whereas cholesterol oxides and brown colour scores gradually increased but remained lower than those of vacuum-packed sausages. Higher residual oxygen in vacuum packing could be responsible for the observed differences in oxidative stability.

Propiedades peculiares de los sistemas de cúmulos globulares y su relación con la formación de sus galaxias anfitrionas

NASA Astrophysics Data System (ADS)

Bassino, L. P.

2017-10-01

Globular clusters (GCs) are ancient stellar systems, among the oldest ones in the Universe. As a consequence, they carry information related to the formation and evolution of their host-galaxies. The study of GC systems associated with early-type galaxies has shown that most of them have similar characteristics. Among them, the most noticeable is the existence of two GC subpopulations (metal-poor and metal-rich, respectively), that differ clearly in their colour distribution, spatial distribution, and kinematics. However, GC systems whose properties differ from the known ``classic'' ones, have been detected in the last years. For instance, the case of GC systems that present more than two subpopulations in their colour distribution or anomalies in the luminosity function. The peculiar properties of the GC systems, together with characteristics of the host-galaxy like the presence of type Ia SNe, the surface-brightness distribution, or the colour map, may be related to bursts of star formation and let us rebuild the host-galaxy history.

Effect of chard powder on colour and aroma formation in cooked sausages

NASA Astrophysics Data System (ADS)

Nasonova, V. V.; Tunieva, E. K.

2017-09-01

The use of nitrate-containing vegetable powders instead of sodium nitrite in meat products requires changes in technological production parameters in order to obtain traditional organoleptic characteristics in the finished products. The aim of this work was to study the effect of chard powder on colour and aroma formation in cooked sausages. Cooked sausage samples were: control with nitrite curing mixture; type 1 sausages with chard powder and ascorbic acid; type 2 sausages with chard powder and sodium ascorbate. To transform nitrate ions contained in the vegetable chard powder to nitrite ions using a denitrifying culture, preliminary thermal treatments were used: 30 and 60 min at 40±2°C, after which the sausages were cooked until a temperature of 72±2°C was achieved. The sausages were stored for 40 days at 0-6°C. When sausage meat was initially held at 40°C for 60 min, a homogenous pink colour formed in the sausages with the vegetable powder. The indicators of lightness, redness and yellowness in cooked sausages as well as the indicators of instrumental odour assessment did not differ significantly (p>0.05). The indicators of colour stability during storage were 1.1-3.0% higher in the sausages with the chard powder compared to the control. The mass fraction of sodium nitrite in the experimental sausages was 2.0-2.2 higher than in the control (p>0.05). As a result of cooked sausage storage, the differences in the sodium nitrite content in the control and types 1 and 2 sausages were similar. During storage, the mass fraction of sodium nitrite decreased in types 1 and 2 sausages by 55.6 and 54.8%, respectively (p<0.05). Cooked sausages with the chard powder contained 2.1-2.4 times more sodium nitrate than did control sausages (p<0.05). However, all tested sausage samples complied with legislative requirements in terms of their sodium nitrite and nitrate levels.

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

Rapid top-down control over template-guided attention shifts to multiple objects.

PubMed

Grubert, Anna; Fahrenfort, Johannes; Olivers, Christian N L; Eimer, Martin

2017-02-01

Previous research has shown that when observers search for targets defined by a particular colour, attention can be directed rapidly and independently to two target objects that appear in close temporal proximity. We investigated how such rapid attention shifts are modulated by task instructions to selectively attend versus ignore one of these objects. Two search displays that both contained a colour-defined target and a distractor in a different colour were presented in rapid succession, with a stimulus onset asynchrony (SOA) of 100ms. In different blocks, participants were instructed to attend and respond to target-colour objects in the first display and to ignore these objects in the second display, or vice versa. N2pc components were measured to track the allocation of spatial attention to target-colour objects in these two displays. When participants responded to the second display, irrelevant target-colour objects in the first display still triggered N2pc components, demonstrating task-set contingent attentional capture while a feature-specific target template is active. Critically, when participants responded to the first display instead, no N2pc was elicited by target-colour items in the second display, indicating that they no longer rapidly captured attention. However, these items still elicited a longer-latency contralateral negativity (SPCN component), suggesting that attention was oriented towards template-matching objects in working memory. This dissociation between N2pc and SPCN components shows that rapid attentional capture and subsequent attentional selection processes within working memory can be independent. We suggest that early attentional orienting mechanisms can be inhibited when task-set matching objects are no longer task-relevant, and that this type of inhibitory control is a rapid but transient process. Copyright © 2016 Elsevier Inc. All rights reserved.

Innate colour preference, individual learning and memory retention in the ant Camponotus blandus.

PubMed

Yilmaz, Ayse; Dyer, Adrian G; Rössler, Wolfgang; Spaethe, Johannes

2017-09-15

Ants are a well-characterized insect model for the study of visual learning and orientation, but the extent to which colour vision is involved in these tasks remains unknown. We investigated the colour preference, learning and memory retention of Camponotus blandus foragers under controlled laboratory conditions. Our results show that C. blandus foragers exhibit a strong innate preference for ultraviolet (UV, 365 nm) over blue (450 nm) and green (528 nm) wavelengths. The ants can learn to discriminate 365 nm from either 528 nm or 450 nm, independent of intensity changes. However, they fail to discriminate between 450 nm and 528 nm. Modelling of putative colour spaces involving different numbers of photoreceptor types revealed that colour discrimination performance of individual ants is best explained by dichromacy, comprising a short-wavelength (UV) receptor with peak sensitivity at about 360 nm, and a long-wavelength receptor with peak sensitivity between 470 nm and 560 nm. Foragers trained to discriminate blue or green from UV light are able to retain the learned colour information in an early mid-term (e-MTM), late mid-term (l-MTM), early long-term (e-LTM) and late long-term (l-LTM) memory from where it can be retrieved after 1 h, 12 h, 24 h, 3 days and 7 days after training, indicating that colour learning may induce different memory phases in ants. Overall, our results show that ants can use chromatic information in a way that should promote efficient foraging in complex natural environments. © 2017. Published by The Company of Biologists Ltd.

How Bees Discriminate a Pattern of Two Colours from Its Mirror Image

PubMed Central

Horridge, Adrian

2015-01-01

A century ago, in his study of colour vision in the honeybee (Apis mellifera), Karl von Frisch showed that bees distinguish between a disc that is half yellow, half blue, and a mirror image of the same. Although his inference of colour vision in this example has been accepted, some discrepancies have prompted a new investigation of the detection of polarity in coloured patterns. In new experiments, bees restricted to their blue and green receptors by exclusion of ultraviolet could learn patterns of this type if they displayed a difference in green contrast between the two colours. Patterns with no green contrast required an additional vertical black line as a landmark. Tests of the trained bees revealed that they had learned two inputs; a measure and the retinotopic position of blue with large field tonic detectors, and the measure and position of a vertical edge or line with small-field phasic green detectors. The angle between these two was measured. This simple combination was detected wherever it occurred in many patterns, fitting the definition of an algorithm, which is defined as a method of processing data. As long as they excited blue receptors, colours could be any colour to human eyes, even white. The blue area cue could be separated from the green receptor modulation by as much as 50°. When some blue content was not available, the bees learned two measures of the modulation of the green receptors at widely separated vertical edges, and the angle between them. There was no evidence that the bees reconstructed the lay-out of the pattern or detected a tonic input to the green receptors. PMID:25617892

Retail colour stability of lamb meat is influenced by breed type, muscle, packaging and iron concentration.

PubMed

Warner, R D; Kearney, G; Hopkins, D L; Jacob, R H

2017-07-01

The longissmus lumborum (LL) and semimembranosus (SM) muscles from 391 lamb carcasses, derived from various breed types, were used to investigate the effect of animal/muscle factors, packaging type [over-wrap (OW) or high oxygen modified atmosphere packaging (MAP O2 )] and duration of display on redness of meat during simulated retail display. Using statistical models the time required (in days) for redness to reach a threshold value of 3.5 (below this is unacceptable) was predicted. High levels of iron in the SM, but not LL, reduced the time for redness to reach 3.5 by 2-2.6days in MAP O2 and 0.5-0.8days in OW. The greater the proportion of Merino breed type, the shorter was the time for redness to reach the value of 3.5, an effect consistent across muscles and packaging types. In summary, breed type, packaging format, muscle and muscle iron levels had a significant impact on colour stability of sheep meat in oxygen-available packaging systems. Copyright © 2017. Published by Elsevier Ltd.

What-where-when memory in magpies (Pica pica).

PubMed

Zinkivskay, Ann; Nazir, Farrah; Smulders, Tom V

2009-01-01

Some animals have been shown to be able to remember which type of food they hoarded or encountered in which location and how long ago (what-where-when memory). In this study, we test whether magpies (Pica pica) also show evidence of remembering these different aspects of a past episode. Magpies hid red- and blue-dyed pellets of scrambled eggs in a large tray containing wood shavings. They were allowed to make as many caches as they wanted. The birds were then returned either the same day or the next day to retrieve the pellets. If they returned the same day, one colour of pellets was replaced with wooden beads of similar size and colour, while if they returned the next day this would happen to the other colour. Over just a few trials, the birds learned to only search for the food pellets, and ignore the beads, of the appropriate colour for the given retention interval. A probe trial in which all items were removed showed that the birds persisted in searching for the pellets and not the beads. This shows that magpies can remember which food item they hoarded where, and when, even if the food items only differ from each other in their colour and are dispersed throughout a continuous caching substrate.

Flame colour characterization in the visible and infrared spectrum using a digital camera and image processing

NASA Astrophysics Data System (ADS)

Huang, Hua-Wei; Zhang, Yang

2008-08-01

An attempt has been made to characterize the colour spectrum of methane flame under various burning conditions using RGB and HSV colour models instead of resolving the real physical spectrum. The results demonstrate that each type of flame has its own characteristic distribution in both the RGB and HSV space. It has also been observed that the averaged B and G values in the RGB model represent well the CH* and C*2 emission of methane premixed flame. Theses features may be utilized for flame measurement and monitoring. The great advantage of using a conventional camera for monitoring flame properties based on the colour spectrum is that it is readily available, easy to interface with a computer, cost effective and has certain spatial resolution. Furthermore, it has been demonstrated that a conventional digital camera is able to image flame not only in the visible spectrum but also in the infrared. This feature is useful in avoiding the problem of image saturation typically encountered in capturing the very bright sooty flames. As a result, further digital imaging processing and quantitative information extraction is possible. It has been identified that an infrared image also has its own distribution in both the RGB and HSV colour space in comparison with a flame image in the visible spectrum.

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).

Variable coloration is associated with dampened population fluctuations in noctuid moths

PubMed Central

Forsman, Anders; Betzholtz, Per-Eric; Franzén, Markus

2015-01-01

Theory and recent reviews state that greater genetic and phenotypic variation should be beneficial for population abundance and stability. Experimental evaluations of this prediction are rare, of short duration and conducted under controlled environmental settings. The question whether greater diversity in functionally important traits stabilizes populations under more complex ecological conditions in the wild has not been systematically evaluated. Moths are mainly nocturnal, with a large variation in colour patterns among species, and constitute an important food source for many types of organisms. Here, we report the results of a long-term (2003–2013) monitoring study of 115 100 noctuid moths from 246 species. Analysis of time-series data provide rare evidence that species with higher levels of inter-individual variation in colour pattern have higher average abundances and undergo smaller between-year fluctuations compared with species having less variable colour patterns. The signature of interspecific temporal synchronization of abundance fluctuations was weak, suggesting that the dynamics were driven by species-specific biotic interactions rather than by some common, density-independent factor(s). We conclude that individual variation in colour patterns dampens population abundance fluctuations, and suggest that this may partly reflect that colour pattern polymorphism provides protection from visually oriented predators and parasitoids. PMID:25972462

The effect of colouring agent on the physical properties of glass ceramic produced from waste glass for antimicrobial coating deposition

NASA Astrophysics Data System (ADS)

Juoi, J. M.; Ayoob, N. F.; Rosli, Z. M.; Rosli, N. R.; Husain, K.

2016-07-01

Domestic waste glass is utilized as raw material for the production of glass ceramic material (GCM) via sinter crystallisation route. The glass ceramic material in a form of tiles is to be utilized for the deposition of Ag-TiO2 antimicrobial coating. Two types of soda lime glass (SLG) that are non-coloured and green SLG are utilised as main raw materials during the batch formulation in order to study the effect of colouring agent (Fe2O3) on the physical and mechanical properties of glass ceramic produced. Glass powder were prepared by crushing bottles using hammer milled with milling machine and sieved until they passed through 75 µm sieve. The process continues by mixing glass powder with ball clay with ratio of 95:5 wt. %, 90:10 wt. % and 85:15 wt. %. Each batch mixture was then uniaxial pressed and sintered at 800°C, 825 °C and 850 °C. The physical and mechanical properties were then determined and compared between those produced from non-coloured and green coloured SLG in order to evaluate the effect of colouring agent (Fe2O3) on the GCM produced. The optimum properties of non-coloured SLG is produced with smaller ball clay content (10 wt. %) compared to green SLG (15 wt. %). The physical properties (determined thru ASTM C373) of the optimized GCM produced from non-coloured SLG and green SLG are 0.69 % of porosity, 1.92 g/cm3 of bulk density, 0.36 % of water absorption; and 1.96 % of porosity, 2.69 g/cm3 of bulk density, 0.73 % of water absorption; respectively. Results also indicate that the most suitable temperature in producing GCM from both glasses with optimized physical and mechanical properties is at 850 °C.

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.

Best practices for hybridization design in two-colour microarray analysis.

PubMed

Knapen, Dries; Vergauwen, Lucia; Laukens, Kris; Blust, Ronny

2009-07-01

Two-colour microarrays are a popular platform of choice in gene expression studies. Because two different samples are hybridized on a single microarray, and several microarrays are usually needed in a given experiment, there are many possible ways to combine samples on different microarrays. The actual combination employed is commonly referred to as the 'hybridization design'. Different types of hybridization designs have been developed, all aimed at optimizing the experimental setup for the detection of differentially expressed genes while coping with technical noise. Here, we first provide an overview of the different classes of hybridization designs, discussing their advantages and limitations, and then we illustrate the current trends in the use of different hybridization design types in contemporary research.

Ethnic variation in melanin content and composition in photoexposed and photoprotected human skin.

PubMed

Alaluf, Simon; Atkins, Derek; Barrett, Karen; Blount, Margaret; Carter, Nik; Heath, Alan

2002-04-01

We have examined the quantity and composition of melanin in both photoprotected (volar upper arm) and chronically photoexposed (dorsal forearm) skin from a range of different ethnic skin types including African, Indian, Mexican, Chinese and European. The most lightly pigmented (European, Chinese and Mexican) skin types have approximately half as much epidermal melanin as the most darkly pigmented (African and Indian) skin types. However, the composition of melanin in these lighter skin types is comparatively more enriched with lightly coloured, alkali-soluble melanin components (up to three-fold). Regardless of ethnicity, epidermal melanin content is significantly greater in chronically photoexposed skin than it is in corresponding photoprotected skin (up to two-fold). However, by comparison there is only a modest enrichment of lightly coloured, alkali soluble melanin components in photoprotected skin (up to 1.3-fold). Analysis of melanosomes extracted from the epidermis in these subjects indicates that the proportion of spheroidal melanosomes is low in all skin types examined (<10%). This suggests that in human skin, pheomelanin is a very minor component of epidermal melanin, even in the lightest (European) skin types. Analysis of melanosome size revealed a significant and progressive variation in size with ethnicity: African skin having the largest melanosomes followed in turn by Indian, Mexican, Chinese and European. On the basis of these findings, we propose that variation in skin pigmentation is strongly influenced by both the amount and the composition (or colour) of the melanin in the epidermis. Variation in melanosome size may also play a significant role. However, the data also suggest that in human skin there are subtle differences in the mechanisms associated with the maintenance of constitutive pigmentation and facultative hyperpigmentation, respectively.

Developmental charts for children with osteogenesis imperfecta, type I (body height, body weight and BMI).

PubMed

Graff, Krzysztof; Syczewska, Malgorzata

2017-03-01

Osteogenesis imperfecta (OI) is a rare genetic disorder of type I collagen. Type I is the most common, which is called a non-deforming type of OI, as in this condition, there are no major bone deformities. This type is characterised by blue sclera and vertebral fractures, leading to mild scoliosis. The body height of these patients is regarded as normal, or only slightly reduced, but there are no data proving this in the literature. The aim of this study is the preparation of the developmental charts of children with OI type I. The anthropometric data of 117 patients with osteogenesis imperfecta were used in this study (61 boys and 56 girls). All measurements were pooled together into one database (823 measurements in total). To overcome the problem of the limited number of data being available in certain age classes and gender groups, the method called reverse transformation was used. The body height of the youngest children, aged 2 and 3 years, is less than that of their healthy peers. Children between 4 and 7 years old catch up slightly, but at later ages, development slows down, and in adults, the median body height shows an SDS of -2.7. These results show that children with type I OI are smaller from the beginning than their healthy counterparts, their development slows down from 8 years old, and, ultimately, their body height is impaired. What is Known: • The body height of patients with osteogenesis imperfecta type I is regarded as normal, or only slightly reduced, but in the known literature, there is no measurement data supporting this opinion. What is New: • Children with type I osteogenesis imperfecta are smaller from the beginning than their healthy counterparts, their development slows down from 8 years old and, ultimately, their final body height is impaired. • The developmental charts for the body height, body weight and BMI of children with type I osteogenesis imperfecta are shown.

A complex carotenoid palette tunes avian color vision.

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

Timlin, Jerilyn A.; Toomey, Matthew B.; Collins, Aaron M.

The brilliantly coloured cone oil droplets of the avian retina function as long-pass cut-off filters that tune the spectral sensitivity of the photoreceptors and are hypothesized to enhance colour discrimination and improve colour constancy. Although it has long been known that these droplets are pigmented with carotenoids, their precise composition has remained uncertain owing to the technical challenges of measuring these very small, dense and highly refractile optical organelles. In this study, we integrated results from high-performance liquid chromatography, hyperspectral microscopy and microspectrophotometry to obtain a comprehensive understanding of oil droplet carotenoid pigmentation in the chicken ( Gallus gallus). Wemore » find that each of the four carotenoid-containing droplet types consists of a complex mixture of carotenoids, with a single predominant carotenoid determining the wavelength of the spectral filtering cut-off. Consistent with previous reports, we find that the predominant carotenoid type in the oil droplets of long-wavelength-sensitive, medium-wavelength-sensitive and short-wavelength-sensitive type 2 cones are astaxanthin, zeaxanthin and galloxanthin, respectively. In addition, the oil droplet of the principal member of the double cone contains a mixture of galloxanthin and two hydroxycarotenoids (lutein and zeaxanthin). Short-wavelength-absorbing apocarotenoids are present in all of the droplet types, providing filtering of light in a region of the spectrum where filtering by hydroxy- and ketocarotenoids may be incomplete. Furthermore, birds rely on a complex palette of carotenoid pigments within their cone oil droplets to achieve finely tuned spectral filtering.« less

A complex carotenoid palette tunes avian color vision.

DOE PAGES

Timlin, Jerilyn A.; Toomey, Matthew B.; Collins, Aaron M.; ...

2015-10-07

The brilliantly coloured cone oil droplets of the avian retina function as long-pass cut-off filters that tune the spectral sensitivity of the photoreceptors and are hypothesized to enhance colour discrimination and improve colour constancy. Although it has long been known that these droplets are pigmented with carotenoids, their precise composition has remained uncertain owing to the technical challenges of measuring these very small, dense and highly refractile optical organelles. In this study, we integrated results from high-performance liquid chromatography, hyperspectral microscopy and microspectrophotometry to obtain a comprehensive understanding of oil droplet carotenoid pigmentation in the chicken ( Gallus gallus). Wemore » find that each of the four carotenoid-containing droplet types consists of a complex mixture of carotenoids, with a single predominant carotenoid determining the wavelength of the spectral filtering cut-off. Consistent with previous reports, we find that the predominant carotenoid type in the oil droplets of long-wavelength-sensitive, medium-wavelength-sensitive and short-wavelength-sensitive type 2 cones are astaxanthin, zeaxanthin and galloxanthin, respectively. In addition, the oil droplet of the principal member of the double cone contains a mixture of galloxanthin and two hydroxycarotenoids (lutein and zeaxanthin). Short-wavelength-absorbing apocarotenoids are present in all of the droplet types, providing filtering of light in a region of the spectrum where filtering by hydroxy- and ketocarotenoids may be incomplete. Furthermore, birds rely on a complex palette of carotenoid pigments within their cone oil droplets to achieve finely tuned spectral filtering.« less

[INVITED] Luminescent QR codes for smart labelling and sensing

NASA Astrophysics Data System (ADS)

Ramalho, João F. C. B.; António, L. C. F.; Correia, S. F. H.; Fu, L. S.; Pinho, A. S.; Brites, C. D. S.; Carlos, L. D.; André, P. S.; Ferreira, R. A. S.

2018-05-01

QR (Quick Response) codes are two-dimensional barcodes composed of special geometric patterns of black modules in a white square background that can encode different types of information with high density and robustness, correct errors and physical damages, thus keeping the stored information protected. Recently, these codes have gained increased attention as they offer a simple physical tool for quick access to Web sites for advertising and social interaction. Challenges encompass the increase of the storage capacity limit, even though they can store approximately 350 times more information than common barcodes, and encode different types of characters (e.g., numeric, alphanumeric, kanji and kana). In this work, we fabricate luminescent QR codes based on a poly(methyl methacrylate) substrate coated with organic-inorganic hybrid materials doped with trivalent terbium (Tb3+) and europium (Eu3+) ions, demonstrating the increase of storage capacity per unit area by a factor of two by using the colour multiplexing, when compared to conventional QR codes. A novel methodology to decode the multiplexed QR codes is developed based on a colour separation threshold where a decision level is calculated through a maximum-likelihood criteria to minimize the error probability of the demultiplexed modules, maximizing the foreseen total storage capacity. Moreover, the thermal dependence of the emission colour coordinates of the Eu3+/Tb3+-based hybrids enables the simultaneously QR code colour-multiplexing and may be used to sense temperature (reproducibility higher than 93%), opening new fields of applications for QR codes as smart labels for sensing.

Height of shock formation in the solar corona inferred from observations of type II radio bursts and coronal mass ejections

NASA Astrophysics Data System (ADS)

Gopalswamy, N.; Xie, H.; Mäkelä, P.; Yashiro, S.; Akiyama, S.; Uddin, W.; Srivastava, A. K.; Joshi, N. C.; Chandra, R.; Manoharan, P. K.; Mahalakshmi, K.; Dwivedi, V. C.; Jain, R.; Awasthi, A. K.; Nitta, N. V.; Aschwanden, M. J.; Choudhary, D. P.

2013-06-01

Employing coronagraphic and EUV observations close to the solar surface made by the Solar Terrestrial Relations Observatory (STEREO) mission, we determined the heliocentric distance of coronal mass ejections (CMEs) at the starting time of associated metric type II bursts. We used the wave diameter and leading edge methods and measured the CME heights for a set of 32 metric type II bursts from solar cycle 24. We minimized the projection effects by making the measurements from a view that is roughly orthogonal to the direction of the ejection. We also chose image frames close to the onset times of the type II bursts, so no extrapolation was necessary. We found that the CMEs were located in the heliocentric distance range from 1.20 to 1.93 solar radii (Rs), with mean and median values of 1.43 and 1.38 Rs, respectively. We conclusively find that the shock formation can occur at heights substantially below 1.5 Rs. In a few cases, the CME height at type II onset was close to 2 Rs. In these cases, the starting frequency of the type II bursts was very low, in the range 25-40 MHz, which confirms that the shock can also form at larger heights. The starting frequencies of metric type II bursts have a weak correlation with the measured CME/shock heights and are consistent with the rapid decline of density with height in the inner corona.

Height of Shock Formation in the Solar Corona Inferred from Observations of Type II Radio Bursts and Coronal Mass Ejections

NASA Technical Reports Server (NTRS)

Gopalswamy, N.; Xie, H.; Makela, P.; Yashiro, S.; Akiyama, S.; Uddin, W.; Srivastava, A. K.; Joshi, N. C.; Chandra, R.; Manoharan, P. K.

2013-01-01

Employing coronagraphic and EUV observations close to the solar surface made by the Solar Terrestrial Relations Observatory (STEREO) mission, we determined the heliocentric distance of coronal mass ejections (CMEs) at the starting time of associated metric type II bursts. We used the wave diameter and leading edge methods and measured the CME heights for a set of 32 metric type II bursts from solar cycle 24. We minimized the projection effects by making the measurements from a view that is roughly orthogonal to the direction of the ejection. We also chose image frames close to the onset times of the type II bursts, so no extrapolation was necessary. We found that the CMEs were located in the heliocentric distance range from 1.20 to 1.93 solar radii (Rs), with mean and median values of 1.43 and 1.38 Rs, respectively. We conclusively find that the shock formation can occur at heights substantially below 1.5 Rs. In a few cases, the CME height at type II onset was close to 2 Rs. In these cases, the starting frequency of the type II bursts was very low, in the range 25-40 MHz, which confirms that the shock can also form at larger heights. The starting frequencies of metric type II bursts have a weak correlation with the measured CME/shock heights and are consistent with the rapid decline of density with height in the inner corona.

Production factors influence fresh lamb longissimus colour more than muscle traits such as myoglobin concentration and pH.

PubMed

Calnan, H; Jacob, R H; Pethick, D W; Gardner, G E

2016-09-01

M. longissimus colour was measured from 8165 lambs at 24h post-mortem using a chromameter. The impact of production factors (site and year of production, slaughter group, sex, age and breed type) and muscle traits (hot carcass weight, pH24, isocitrate dehydrogenase (ICDH) activity, myoglobin, iron and zinc concentrations) on meat lightness (L*), redness (a*), yellowness (b*), hue and chroma were analysed. Greater differences in meat colour were seen between different slaughter groups and sites of production than across the range of any muscle traits. Of the muscle traits analysed, changes in pH24 had the greatest effect on meat a* (2.5 units), while myoglobin had the greatest effect on meat L* (2.9 units). The 3.1 L* unit darkening of meat with increasing lamb age (from 140 to 400days) was accounted for by increased myoglobin concentration. These results suggest that production factors are having substantial effects on lamb colour independent of known influencing muscle traits such as myoglobin concentration and pH. Copyright © 2016 Elsevier Ltd. All rights reserved.

Short term supplementation rates to optimise vitamin E concentration for retail colour stability of Australian lamb meat.

PubMed

Jose, C G; Jacob, R H; Pethick, D W; Gardner, G E

2016-01-01

The relationship between vitamin E supplementation rate and colour stability was investigated using 70 mixed sex 6-8 month old crossbred lambs. An initial group of 10 were slaughtered, while the remainder were fed a pellet ration containing either 30, 150, 275 or 400 IU vitamin E/kg ration or on green pasture for 56 days. After slaughter, carcases were halved; one side packed fresh (5 days) and the other in CO2 (21 days), both at 2°C. Five muscles were set for retail display for 96 h. The oxy/metmyoglobin ratio was measured every 12 h. Colour stability increased with increasing muscle vitamin E until an apparent maximum effect for vitamin E concentration (3.5-4.0mg α-tocopherol/kg tissue) was reached beyond which no further response was evident. This was reached within 3-4 weeks (275 IU treatment), and meat from these lambs should reach 60 h retail display with a satisfactory surface colour. This effect was most apparent in aerobic muscle types and meat aged post slaughter. Copyright © 2015 Elsevier Ltd. All rights reserved.

Exploring structural colour in uni- and multi-coloured butterfly wings and Ag+ uptake by scales

NASA Astrophysics Data System (ADS)

Aideo, Swati N.; Haloi, Rajib; Mohanta, Dambarudhar

2017-09-01

We discuss the origin of the structural colour of different butterfly wings in the light of the typical built-in microstructural arrangement of scales that are comprised of chitin-melanin layer and air-gaps. Three specimens of butterfly wings namely, Papilio Liomedon (black), Catopsilia Pyranthe (light green) and Vanessa Cardui (multi-coloured) were chosen and diffuse reflectance characteristics have been aquired for normal incidence of p-polarized light. Moreover, the time-dependent uptake of Ag+ into scales has led to swelling and spread of the chitinous ridges and ribs, with revelation of micro-beads in Catopsilia Pyranthe specimen. The reduction of the number of air-gaps between any two parallel ridges is attributed to the merging of adjacent gaps possessing a common boundary. The availability of Ag at the centre of a chosen ridge, for every wing type, follows an exponential growing trend, ∼e0.36t . Precise inclusion of nanoscale metals into natural photonic systems would provide new insight, while applying principles of photonics and plasmonics simultaneously.

A bright side, facet analysis of histrionic personality disorder: the relationship between the HDS Colourful factor and the NEO-PI-R facets in a large adult sample.

PubMed

Furnham, Adrian

2014-01-01

This study looks at "bright-side," Big Five Personality trait correlates of a "dark-side" Personality Disorder, namely Histrionic Personality Disorder (HPD). More than 5000 British adults completed the Neuroticism Extraversion Openness Personality Inventory-Revised (Costa & McCrae, 1985), which measures the Big Five Personality factors at the Domain (Super Factor) and the Facet (Factor) level, as well as the Hogan Development Survey (HDS; Hogan & Hogan, 2009), which has a measure of HPD, exclusively called "Colourful" in the HDS terminology. Correlation and regression results confirmed many of the associations between these "bright" and "dark" side individual difference variables. The Colourful (HPD) score from the HDS was the criterion variable in all analyses. Colourful individuals are high on Extraversion and Openness, but also Stable and disagreeable. The Facet analysis identified Assertiveness and Immodesty as particularly characteristic of that type. The study confirmed work on HPD using different population groups and different measures, showing that personality traits are predictable and correlated with various personality disorders.

Simultaneous colour visualizations of multiple ALS point cloud attributes for land cover and vegetation analysis

NASA Astrophysics Data System (ADS)

Zlinszky, András; Schroiff, Anke; Otepka, Johannes; Mandlburger, Gottfried; Pfeifer, Norbert

2014-05-01

LIDAR point clouds hold valuable information for land cover and vegetation analysis, not only in the spatial distribution of the points but also in their various attributes. However, LIDAR point clouds are rarely used for visual interpretation, since for most users, the point cloud is difficult to interpret compared to passive optical imagery. Meanwhile, point cloud viewing software is available allowing interactive 3D interpretation, but typically only one attribute at a time. This results in a large number of points with the same colour, crowding the scene and often obscuring detail. We developed a scheme for mapping information from multiple LIDAR point attributes to the Red, Green, and Blue channels of a widely used LIDAR data format, which are otherwise mostly used to add information from imagery to create "photorealistic" point clouds. The possible combinations of parameters are therefore represented in a wide range of colours, but relative differences in individual parameter values of points can be well understood. The visualization was implemented in OPALS software, using a simple and robust batch script, and is viewer independent since the information is stored in the point cloud data file itself. In our case, the following colour channel assignment delivered best results: Echo amplitude in the Red, echo width in the Green and normalized height above a Digital Terrain Model in the Blue channel. With correct parameter scaling (but completely without point classification), points belonging to asphalt and bare soil are dark red, low grassland and crop vegetation are bright red to yellow, shrubs and low trees are green and high trees are blue. Depending on roof material and DTM quality, buildings are shown from red through purple to dark blue. Erroneously high or low points, or points with incorrect amplitude or echo width usually have colours contrasting from terrain or vegetation. This allows efficient visual interpretation of the point cloud in planar, profile and 3D views since it reduces crowding of the scene and delivers intuitive contextual information. The resulting visualization has proved useful for vegetation analysis for habitat mapping, and can also be applied as a first step for point cloud level classification. An interactive demonstration of the visualization script is shown during poster attendance, including the opportunity to view your own point cloud sample files.

The effect of dropping height on jumping performance in trained and untrained prepubertal boys and girls.

PubMed

Bassa, Eleni I; Patikas, Dimitrios A; Panagiotidou, Aikaterini I; Papadopoulou, Sophia D; Pylianidis, Theofilos C; Kotzamanidis, Christos M

2012-08-01

Plyometric training in children, including different types of jumps, has become common practice during the last few years in different sports, although there is limited information about the adaptability of children with respect to different loads and the differences in performance between various jump types. The purpose of this study was to examine the effect of gender and training background on the optimal drop jump height of 9- to 11-year-old children. Sixty prepubertal (untrained and track and field athletes, boys and girls, equally distributed in each group [n = 15]), performed the following in random order: 3 squat jumps, 3 countermovement jumps (CMJs) and 3 drop jumps from heights of 10, 20, 30, 40, and 50 cm. The trial with the best performance in jump height of each test was used for further analysis. The jump type significantly affected the jump height. The jump height during the CMJ was the highest among all other jump types, resulting in advanced performance for both trained and untrained prepubertal boys and girls. However, increasing the dropping height did not change the jumping height or contact time during the drop jump. This possibly indicates an inability of prepubertal children to use their stored elastic energy to increase jumping height during drop jumps, irrespective of their gender or training status. This indicates that children, independent of gender and training status, have no performance gain during drop jumps from heights up to 50 cm, and therefore, it is recommended that only low drop jump heights be included in plyometric training to limit the probability of sustaining injuries.

Growth in children and adolescents with type 1 diabetes.

PubMed

Bonfig, Walter; Kapellen, Thomas; Dost, Axel; Fritsch, Maria; Rohrer, Tilman; Wolf, Johannes; Holl, Reinhard W

2012-06-01

To investigate the effect of type 1 diabetes on growth and adult height. Data from 22 651 children (10 494 females) with type 1 diabetes documented at onset of the disease from specialized centers in Germany and Austria were analyzed. Patients of non-German and non-Austrian origin and patients with celiac disease were excluded from the analysis. Near-adult height data were available in 1685 patients. At the time of diagnosis of type 1 diabetes, the mean age of the 22 651 children was 8.8 ± 4.2 years, with a mean height SDS of 0.22 ± 1.0. The 1685 patients with diabetes onset before age 11 years reached a mean adult height of -0.16 ± 1.0 SDS. Mean adult height was was 167.1 ± 6.2 cm (-0.16 ± 0.97 SDS) in females (n = 846) and 179.6 ± 7.1 cm (-0.17 ± 1.0 SDS) in males (n = 839). Mean duration of diabetes was 9.1 ± 2.6 years, and mean Hemoglobin A1c concentration was 7.9% ± 1.2% (63 ± 10 mmol/mol). In a multivariate regression model, adult height was positively correlated with height at onset of diabetes (P < .0001) and negatively with mean Hemoglobin A1c (P < .0001) and duration of diabetes (P = .0015). Height at the time of diagnosis of type 1 diabetes is above average. Even with intensive insulin therapy, growth and adult height remain indicators of metabolic diabetes control in the 21st century. Copyright © 2012 Mosby, Inc. All rights reserved.

Distribution and photobiology of Symbiodinium types in different light environments for three colour morphs of the coral Madracis pharensis: is there more to it than total irradiance?

NASA Astrophysics Data System (ADS)

Frade, P. R.; Englebert, N.; Faria, J.; Visser, P. M.; Bak, R. P. M.

2008-12-01

The role of symbiont variation in the photobiology of reef corals was addressed by investigating the links among symbiont genetic diversity, function and ecological distribution in a single host species, Madracis pharensis. Symbiont distribution was studied for two depths (10 and 25 m), two different light habitats (exposed and shaded) and three host colour morphs (brown, purple and green). Two Symbiodinium genotypes were present, as defined by nuclear internal transcribed spacer 2 ribosomal DNA (ITS2-rDNA) variation. Symbiont distribution was depth- and colour morph-dependent. Type B15 occurred predominantly on the deeper reef and in green and purple colonies, while type B7 was present in shallow environments and brown colonies. Different light microhabitats at fixed depths had no effect on symbiont presence. This ecological distribution suggests that symbiont presence is potentially driven by light spectral niches. A reciprocal depth transplantation experiment indicated steady symbiont populations under environment change. Functional parameters such as pigment composition, chlorophyll a fluorescence and cell densities were measured for 25 m and included in multivariate analyses. Most functional variation was explained by two photobiological assemblages that relate to either symbiont identity or light microhabitat, suggesting adaptation and acclimation, respectively. Type B15 occurs with lower cell densities and larger sizes, higher cellular pigment concentrations and higher peridinin to chlorophyll a ratio than type B7. Type B7 relates to a larger xanthophyll-pool size. These unambiguous differences between symbionts can explain their distributional patterns, with type B15 being potentially more adapted to darker or deeper environments than B7. Symbiont cell size may play a central role in the adaptation of coral holobionts to the deeper reef. The existence of functional differences between B-types shows that the clade classification does not necessarily correspond to functional identity. This study supports the use of ITS2 as an ecological and functionally meaningful marker in Symbiodinium.

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.

Amiodarone-induced thyrotoxicosis: A review

PubMed Central

Tsang, Wendy; Houlden, Robyn L

2009-01-01

BACKGROUND: Amiodarone-induced thyrotoxicosis (AIT) develops in 3% of amiodarone-treated patients in North America. AIT is classified as type 1 or type 2. Type 1 AIT occurs in patients with underlying thyroid pathology such as autonomous nodular goiter or Graves’ disease. Type 2 AIT is a result of amiodarone causing a subacute thyroiditis with release of preformed thyroid hormones into the circulation. OBJECTIVES: To review the literature and present an overview of the differentiation between and management of type 1 and type 2 AIT. METHODS: PubMed, the Cumulative Index to Nursing and Allied Health Literature and Medscape searches of all available English language articles from 1983 to 2006 were performed. Search terms included ‘amiodarone-induced thyrotoxicosis’, ‘complications’, ‘management’, ‘treatment’ and ‘colour flow Dopper sonography’. RESULTS: There is evidence to suggest that to differentiate between type 1 and type 2 AIT, a careful history and physical examination should be performed to identify pre-existing thyroid disease. An iodine-131 uptake test and colour flow Doppler sonography should be performed. Patients with type 2 AIT should receive a trial of glucocorticoids, whereas those with type 1 should receive antithyroid therapy. For patients in whom the mechanism of the thyrotoxicosis is unclear, a combination of prednisone and antithyroid therapy may be considered. PMID:19584973

Effect of different types of disinfection solution and aging on the hardness and colour stability of maxillofacial silicone elastomers.

PubMed

Cevik, Pinar; Yildirim-Bicer, Arzu Z

2017-11-09

Understanding the effect of aging and different disinfecting agents on the physical properties of pigmented maxillofacial silicones may help eliminate the current uncertainty as to the best follow-up suggestions for the patients treated with silicone prostheses. One hundred fifty specimens (14 × 2 mm) were evaluated for colour and 75 specimens (30 × 10 mm) for hardness (total, 225 specimens). Five specimens were used for hardness testing in each disinfecting solution while 10 silicone specimens were used for colour evaluation. The samples were separated into 5 groups and the initial hardness and colour evaluations were performed and placed in disinfectant solution (neutral soap, effervescent tablet, 0.2% chlorhexidine, 4% chlorhexidine, sodium hypochlorite). A second set of colour and hardness measurements was taken after 48 hours of disinfection and 1,008 hours of artificial aging in a QUV-accelerated weathering tester. Two-way and 1-way analysis of variance with Tukey tests and paired t-test were used for statistical analysis (α = 0.05). Before artificial aging, the hardness value of the red pigment group was found to be significantly lower than that of the brown pigment group. After aging, the lowest Shore A value was seen in the neutral soap group, while the highest was seen in the effervescent tablet. Based on the results of this study, chlorohexidine 0.2% was found to be most suitable agent for disinfection of the prostheses. Washing with neutral soap caused loss of pigment from the surface of the silicones. Sodium hypochlorite was found to have a colour-fading effect on silicone specimens.

Size matters for violent discharge height and settling speed of Sphagnum spores: important attributes for dispersal potential.

PubMed

Sundberg, Sebastian

2010-02-01

Initial release height and settling speed of diaspores are biologically controlled components which are key to modelling wind dispersal. Most Sphagnum (peat moss) species have explosive spore liberation. In this study, how capsule and spore sizes affect the height to which spores are propelled were measured, and how spore size and spore number of discharged particles relate to settling speed in the aspherical Sphagnum spores. Spore discharge and spore cloud development were filmed in a closed chamber (nine species). Measurements were taken from snapshots at three stages of cloud development. Settling speed of spores (14 species) and clusters were timed in a glass tube. The maximum discharge speed measured was 3.6 m s(-1). Spores reached a maximum height of 20 cm (average: 15 cm) above the capsule. The cloud dimensions at all stages were related positively to capsule size (R(2) = 0.58-0.65). Thus species with large shoots (because they have large capsules) have a dispersal advantage. Half of the spores were released as singles and the rest as clusters (usually two to four spores). Single spores settled at 0.84-1.86 cm s(-1), about 52 % slower than expected for spherical spores with the same diameters. Settling speed displayed a positive curvilinear relationship with spore size, close to predictions by Stokes' law for spherical spores with 68 % of the actual diameters. Light-coloured spores settled slower than dark spores. Settling speed of spore clusters agrees with earlier studies. Effective spore discharge and small, slowly settling spores appear particularly important for species in forested habitats. The spore discharge heights in Sphagnum are among the greatest for small, wind-dispersed propagules. The discharge heights and the slow settling of spores affect dispersal distances positively and may help to explain the wide distribution of most boreal Sphagnum species.

Size matters for violent discharge height and settling speed of Sphagnum spores: important attributes for dispersal potential

PubMed Central

Sundberg, Sebastian

2010-01-01

Background and Aims Initial release height and settling speed of diaspores are biologically controlled components which are key to modelling wind dispersal. Most Sphagnum (peat moss) species have explosive spore liberation. In this study, how capsule and spore sizes affect the height to which spores are propelled were measured, and how spore size and spore number of discharged particles relate to settling speed in the aspherical Sphagnum spores. Methods Spore discharge and spore cloud development were filmed in a closed chamber (nine species). Measurements were taken from snapshots at three stages of cloud development. Settling speed of spores (14 species) and clusters were timed in a glass tube. Key Results The maximum discharge speed measured was 3·6 m s−1. Spores reached a maximum height of 20 cm (average: 15 cm) above the capsule. The cloud dimensions at all stages were related positively to capsule size (R2 = 0·58–0·65). Thus species with large shoots (because they have large capsules) have a dispersal advantage. Half of the spores were released as singles and the rest as clusters (usually two to four spores). Single spores settled at 0·84–1·86 cm s−1, about 52 % slower than expected for spherical spores with the same diameters. Settling speed displayed a positive curvilinear relationship with spore size, close to predictions by Stokes' law for spherical spores with 68 % of the actual diameters. Light-coloured spores settled slower than dark spores. Settling speed of spore clusters agrees with earlier studies. Effective spore discharge and small, slowly settling spores appear particularly important for species in forested habitats. Conclusions The spore discharge heights in Sphagnum are among the greatest for small, wind-dispersed propagules. The discharge heights and the slow settling of spores affect dispersal distances positively and may help to explain the wide distribution of most boreal Sphagnum species. PMID:20123930

Effects of cane length and diameter and judgment type on the constant error ratio for estimated height in blindfolded, visually impaired, and sighted participants.

PubMed

Huang, Kuo-Chen; Leung, Cherng-Yee; Wang, Hsiu-Feng

2010-04-01

The purpose of this study was to assess the ability of blindfolded, visually impaired, and sighted individuals to estimate object height as a function of cane length, cane diameter, and judgment type. 48 undergraduate students (ages 20 to 23 years) were recruited to participate in the study. Participants were divided into low-vision, severely myopic, and normal-vision groups. Five stimulus heights were explored with three cane lengths, varying cane diameters, and judgment types. The participants were asked to estimate the stimulus height with or without reference to a standard block. Results showed that the constant error ratio for estimated height improved with decreasing cane length and comparative judgment. The findings were unclear regarding the effect of cane length on haptic perception of height. Implications were discussed for designing environments, such as stair heights, chairs, the magnitude of apertures, etc., for visually impaired individuals.

Camouflage effects of various colour-marking morphs against different microhabitat backgrounds in a polymorphic pygmy grasshopper Tetrix japonica.

PubMed

Tsurui, Kaori; Honma, Atsushi; Nishida, Takayoshi

2010-07-06

Colour-marking polymorphism is widely distributed among cryptic species. To account for the adaptive significance of such polymorphisms, several hypotheses have been proposed to date. Although these hypotheses argue over the degree of camouflage effects of marking morphs (and the interactions between morphs and their microhabitat backgrounds), as far as we know, most empirical evidence has been provided under unnatural conditions (i.e., using artificial prey). Tetrix japonica, a pygmy grasshopper, is highly polymorphic in colour-markings and occurs in both sand and grass microhabitats. Even within a microhabitat, T. japonica is highly polymorphic. Using humans as dummy predators and printed photographs in which various morphs of grasshoppers were placed against different backgrounds, we addressed three questions to test the neutral, background heterogeneity, and differential crypsis hypotheses in four marking-type morphs: 1) do the morphs differ in the degree of crypsis in each microhabitat, 2) are different morphs most cryptic in specific backgrounds of the microhabitats, and 3) does the morph frequency reflect the degree of crypsis? The degree of camouflage differed among the four morphs; therefore, the neutral hypothesis was rejected. Furthermore, the order of camouflage advantage among morphs differed depending on the two types of backgrounds (sand and grass), although the grass background consistently provided greater camouflage effects. Thus, based on our results, we could not reject the background heterogeneity hypothesis. Under field conditions, the more cryptic morphs comprised a minority of the population. Overall, our results demonstrate that the different morphs were not equivalent in the degree of crypsis, but the degree of camouflage of the morphs was not consistent with the morph frequency. These findings suggest that trade-offs exist between the camouflage benefit of body colouration and other fitness components, providing a better understanding of the adaptive significance of colour-markings and presumably supporting the differential crypsis hypothesis.

Multi-ion detection by one-shot optical sensors using a colour digital photographic camera.

PubMed

Lapresta-Fernández, Alejandro; Capitán-Vallvey, Luis Fermín

2011-10-07

The feasibility and performance of a procedure to evaluate previously developed one-shot optical sensors as single and selective analyte sensors for potassium, magnesium and hardness are presented. The procedure uses a conventional colour digital photographic camera as the detection system for simultaneous multianalyte detection. A 6.0 megapixel camera was used, and the procedure describes how it is possible to quantify potassium, magnesium and hardness simultaneously from the images captured, using multianalyte one-shot sensors based on ionophore-chromoionophore chemistry, employing the colour information computed from a defined region of interest on the sensing membrane. One of the colour channels in the red, green, blue (RGB) colour space is used to build the analytical parameter, the effective degree of protonation (1-α(eff)), in good agreement with the theoretical model. The linearization of the sigmoidal response function increases the limit of detection (LOD) and analytical range in all cases studied. The increases were from 5.4 × 10(-6) to 2.7 × 10(-7) M for potassium, from 1.4 × 10(-4) to 2.0 × 10(-6) M for magnesium and from 1.7 to 2.0 × 10(-2) mg L(-1) of CaCO(3) for hardness. The method's precision was determined in terms of the relative standard deviation (RSD%) which was from 2.4 to 7.6 for potassium, from 6.8 to 7.8 for magnesium and from 4.3 to 7.8 for hardness. The procedure was applied to the simultaneous determination of potassium, magnesium and hardness using multianalyte one-shot sensors in different types of waters and beverages in order to cover the entire application range, statistically validating the results against atomic absorption spectrometry as the reference procedure. Accordingly, this paper is an attempt to demonstrate the possibility of using a conventional digital camera as an analytical device to measure this type of one-shot sensor based on ionophore-chromoionophore chemistry instead of using conventional lab instrumentation.

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.

[Final size attained in type 1 diabetes children].

PubMed

Galera Martínez, R; García García, E; Gámez Gómez, M D; Gómez Llorente, J L; Garrido Fernández, P; Bonillo Perales, A

2009-03-01

To describe the final height and height-gain in relation to target height, in children with type 1 diabetes mellitus, and analyse their relationship to different variables. Retrospective analysis of the growth data of 52 children (27 girls) diagnosed with type 1 diabetes mellitus before 14 years old, and followed up until their final height was attained. final height, target height, illness duration, glycated haemoglobin (HbA1c), insulin dose, BMI, and other autoimmune diseases. The height SDS (standard deviation scale) at diagnosis was slightly higher (0.734 in boys and 0.563 in girls). During the development of the disease, a growth reduction was seen, which was significantly higher in boys of prepubertal age (p = 0.016). The mean final height attained was 173.14 +/- 5.28 cm in boys and 161.9 +/- 6.97 cm in girls. Height gain was 1.56 +/- 3.66 in boys (SDS = -0.034) and 2.26 +/- 6.13 in girls (SDS = 0.385). The only variable significantly related to height gain was mean glycated-haemoglobin (growth reduction of 2 cm for every increment of 1% in mean glycated-haemoglobin). At onset, diabetic children were slightly taller than the general population. A growth reduction was shown as the disease developed, significantly higher in boys of prepubertal age. The final height in boys was slightly lower than the mean, but in girls was similar to the general population. Both sexes attained their target height, although the height gain was less in boys. Poorer metabolic control was associated with reduced height gain.

Interplanetary type II radio bursts and their association with CMEs and flares

NASA Astrophysics Data System (ADS)

Shanmugaraju, A.; Suresh, K.; Vasanth, V.; Selvarani, G.; Umapathy, S.

2018-06-01

We study the characteristics of the CMEs and their association with the end-frequency of interplanetary (IP)-type-II bursts by analyzing a set of 138 events (IP-type-II bursts-flares-CMEs) observed during the period 1997-2012. The present analysis consider only the type II bursts having starting frequency < 14 MHz to avoid the extension of coronal type IIs. The selected events are classified into three groups depending on the end-frequency of type IIs as follows, (A) Higher, (B) Intermediate and (C) Lower end-frequency. We compare characteristics of CMEs, flares and type II burst for the three selected groups of events and report some of the important differences. The observed height of CMEs is compared with the height of IP type IIs estimated using the electron density models. By applying a density multiplier (m) to this model, the density has been constrained both in the upper corona and in the interplanetary medium, respectively as m= 1 to 10 and m = 1 to 3. This study indicates that there is a correlation between the observed CME height and estimated type II height for groups B and C events whereas this correlation is absent in group A. In all the groups (A, B & C), the different heights of CMEs and type II reveal that the type IIs are not only observed at the nose but also at the flank of the CMEs.

ISO observations of obscured Asymptotic Giant Branch stars in the Large Magellanic Cloud

NASA Astrophysics Data System (ADS)

Trams, N. R.; van Loon, J. Th.; Waters, L. B. F. M.; Zijlstra, A. A.; Loup, C.; Whitelock, P. A.; Groenewegen, M. A. T.; Blommaert, J. A. D. L.; Siebenmorgen, R.; Heske, A.; Feast, M. W.

1999-06-01

We present ISO photometric and spectroscopic observations of a sample of 57 bright Asymptotic Giant Branch stars and red supergiants in the Large Magellanic Cloud, selected on the basis of IRAS colours indicative of high mass-loss rates. PHOT-P and PHOT-C photometry at 12, 25 and 60 mu m and CAM photometry at 12 mu m are used in combination with quasi-simultaneous ground-based near-IR photometry to construct colour-colour diagrams for all stars in our sample. PHOT-S and CAM-CVF spectra in the 3 to 14 mu m region are presented for 23 stars. From the colour-colour diagrams and the spectra, we establish the chemical types of the dust around 49 stars in this sample. Many stars have carbon-rich dust. The most luminous carbon star in the Magellanic Clouds has also a (minor) oxygen-rich component. OH/IR stars have silicate absorption with emission wings. The unique dataset presented here allows a detailed study of a representative sample of thermal-pulsing AGB stars with well-determined luminosities. This paper is based on observations with the Infrared Space Observatory (ISO). ISO is an ESA project with instruments funded by ESA member states (especially the PI countries: France, Germany, The Netherlands and the United Kingdom) and with the participation of ISAS and NASA.

Clinical and patient reported outcomes of bleaching effectiveness.

PubMed

Klaric Sever, Eva; Budimir, Zrinka; Cerovac, Matea; Stambuk, Mario; Par, Matej; Negovetic Vranic, Dubravka; Tarle, Zrinka

2018-01-01

The objective of this study is to evaluate clinical and patient reported outcomes of different bleaching products. Thirty participants were randomly divided into three bleaching groups (n = 10). Bleaching was performed with high concentrations of hydrogen peroxide (HP) - Boost (40%) and Dash (30%), and with prefabricated splints Bite&White (6% HP). Tooth colour was measured before, immediately after, and 1 and 6 months after the bleaching by using classical shade guide and spectrophotometer. Tooth hypersensitivity was self-rated by patients on the Wong-Baker's face scale. Patient satisfaction was evaluated on a 7-point Likert-type scales that measured perceived performance and importance of different characteristics of bleaching treatment. All products were effective in teeth colour change (ΔE > 3.3), which was significantly higher for Boost (p = .016) and Dash (p = .024) than Bite&White treatment. Perception of hypersensitivity was the highest in Boost group, followed by Dash and Bite&White treatment. Most of the patients were satisfied with final tooth colour, length and comfort during treatment, but were dissatisfied with the stability of bleached tooth colour. Materials with the higher concentrations of bleaching agent demonstrated greater bleaching effectiveness than at-home bleaching product, but also a greater hypersensitivity. Lengthening the treatment process, but achieving a more stable tooth colour may improve the perceived value of a bleaching service.

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.

16 CFR 309.17 - Labels.

Code of Federal Regulations, 2010 CFR

2010-01-01

... height) knocked out of a 1″ (2.54 cm) deep band. The type for the words “MINIMUM” and the principal... should be set as “normal.” The type for the fuel name is 50 point (1/2″ 1.27 cm) cap height) knocked out... point (1/2″ 1.27 cm) cap height) knocked out of a 1″ (2.54 cm) deep band. All other type is 24 pt. (1/4...

16 CFR 309.17 - Labels.

Code of Federal Regulations, 2011 CFR

2011-01-01

... height) knocked out of a 1″ (2.54 cm) deep band. The type for the words “MINIMUM” and the principal... should be set as “normal.” The type for the fuel name is 50 point (1/2″ 1.27 cm) cap height) knocked out... point (1/2″ 1.27 cm) cap height) knocked out of a 1″ (2.54 cm) deep band. All other type is 24 pt. (1/4...

Binding blocks: building the Universe one nucleus at a time

NASA Astrophysics Data System (ADS)

Diget, C. Aa; Pastore, A.; Leech, K.; Haylett, T.; Lock, S.; Sanders, T.; Shelley, M.; Willett, H. V.; Keegans, J.; Sinclair, L.; Simpson, E. C.; Binding Blocks Collaboration

2017-03-01

We present a new teaching and outreach activity based around the construction of a three-dimensional chart of isotopes using \\text{LEG}{{\\text{O}}\\circledR} bricks5. The activity, binding blocks, demonstrates nuclear and astrophysical processes through a seven-meter chart of all nuclear isotopes, built from over 26 000 \\text{LEG}{{\\text{O}}\\circledR} bricks. It integrates A-Level and GCSE curricula across areas of nuclear physics, astrophysics, and chemistry, including: nuclear decays (through the colours in the chart); nuclear binding energy (through tower heights); production of chemical elements in the cosmos; fusion processes in stars and fusion energy on Earth; as well as links to medical physics, particularly diagnostics and radiotherapy.

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.

ESTIMATING THE HEIGHT OF CMEs ASSOCIATED WITH A MAJOR SEP EVENT AT THE ONSET OF THE METRIC TYPE II RADIO BURST DURING SOLAR CYCLES 23 AND 24

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

Mäkelä, P.; Akiyama, S.; Xie, H.

2015-06-10

We studied the coronal mass ejection (CME) height at the onset of 59 metric type II radio bursts associated with major solar energetic particle (SEP) events, excluding ground level enhancements (GLEs), during solar cycles 23 and 24. We calculated CME heights using a simple flare-onset method used by Gopalswamy et al. to estimate CME heights at the metric type II onset for cycle 23 GLEs. We found the mean CME height for non-GLE events (1.72 R{sub ☉}) to be ∼12% greater than that (1.53 R{sub ☉}) for cycle 23 GLEs. The difference could be caused by more impulsive acceleration ofmore » the GLE-associated CMEs. For cycle 24 non-GLE events, we compared the CME heights obtained using the flare-onset method and the three-dimensional spherical-shock fitting method and found the correlation to be good (CC = 0.68). We found the mean CME height for cycle 23 non-GLE events (1.79 R{sub ☉}) to be greater than that for cycle 24 non-GLE events (1.58 R{sub ☉}), but statistical tests do not definitely reject the possibility of coincidence. We suggest that the lower formation height of the shocks during cycle 24 indicates a change in the Alfvén speed profile because solar magnetic fields are weaker and plasma density levels are closer to the surface than usual during cycle 24. We also found that complex type III bursts showing diminution of type III emission in the 7–14 MHz frequency range are more likely associated with events with a CME height at the type II onset above 2 R{sub ☉}, supporting suggestions that the CME/shock structure causes the feature.« less

Proper use of colour schemes for image data visualization

NASA Astrophysics Data System (ADS)

Vozenilek, Vit; Vondrakova, Alena

2018-04-01

With the development of information and communication technologies, new technologies are leading to an exponential increase in the volume and types of data available. At this time of the information society, data is one of the most important arguments for policy making, crisis management, research and education, and many other fields. An essential task for experts is to share high-quality data providing the right information at the right time. Designing of data presentation can largely influence the user perception and the cognitive aspects of data interpretation. Significant amounts of data can be visualised in some way. One image can thus replace a considerable number of numeric tables and texts. The paper focuses on the accurate visualisation of data from the point of view of used colour schemes. Bad choose of colours can easily confuse the user and lead to the data misinterpretation. On the contrary, correctly created visualisations can make information transfer much simpler and more efficient.

Purple anthocyanin colouration on lower (abaxial) leaf surface of Hemigraphis colorata (Acanthaceae)

PubMed Central

Skaar, Irene; Adaku, Christopher; Jordheim, Monica; Byamukama, Robert; Kiremire, Bernard; Andersen, Øyvind M.

2014-01-01

The functional significance of anthocyanin colouration of lower (abaxial) leaf surfaces is not clear. Two anthocyanins, 5-O-methylcyanidin 3-O-(3″-(β-glucuronopyranosyl)-β-glucopyranoside) (1) and 5-O-methylcyanidin 3-O-β-glucopyranoside (2), were isolated from Hemigraphis colorata (Blume) (Acanthaceae) leaves with strong purple abaxial colouration (2.2 and 0.6 mg/g fr. wt., respectively). The glycosyl moiety of 1, the disaccharide 3″-(β-glucuronopyranosyl)-β-glucopyranoside), has previously been reported to occur only in a triterpenoid saponin, lindernioside A. The structural assignment of the aglycone of 1 and 2 is the first complete characterisation of a natural 7-hydroxy-5-methoxyanthocyanidin. Compared to nearly all naturally occurring anthocyanidins, the 5-O-methylation of this anthocyanidin limits the type of possible quinoidal forms of 1 and 2 to be those forms with keto-function in only their 7- and 4′-positions. PMID:24957301

Cathodoluminescence, laser ablasion inductively coupled plasma mass spectrometry, electron probe microanalysis and electron paramagnetic resonance analyses of natural sphalerite

USGS Publications Warehouse

Karakus, M.; Hagni, R.D.; Koenig, A.; Ciftc, E.

2008-01-01

Natural sphalerite associated with copper, silver, lead-zinc, tin and tungsten deposits from various world-famous mineral deposits have been studied by cathodoluminescence (CL), laser ablasion inductively coupled plasma mass spectrometry (LA-ICP-MS), electron probe microanalysis (EPMA) and electron paramagnetic resonance (EPR) to determine the relationship between trace element type and content and the CL properties of sphalerite. In general, sphalerite produces a spectrum of CL colour under electron bombardment that includes deep blue, turquoise, lime green, yellow-orange, orange-red and dull dark red depending on the type and concentration of trace quantities of activator ions. Sphalerite from most deposits shows a bright yellow-orange CL colour with ??max centred at 585 nm due to Mn2+ ion, and the intensity of CL is strongly dependent primarily on Fe2+ concentration. The blue emission band with ??max centred at 470-490 nm correlates with Ga and Ag at the Tsumeb, Horn Silver, Balmat and Kankoy mines. Colloform sphalerite from older well-known European lead-zinc deposits and late Cretaceous Kuroko-type VMS deposits of Turkey shows intense yellowish CL colour and their CL spectra are characterised by extremely broad emission bands ranging from 450 to 750 nm. These samples are characterised by low Mn (<10 ppm) and Ag (<1 ppm), and they are enriched in Tl (1-30 ppm) and Pb (80-1500 ppm). Strong green CL is produced by sphalerite from the Balmat-Edwards district. Amber, lime-green and red-orange sphalerite produced weak orange-red CL at room temperatures, with several emission bands centred at 490, 580, 630, 680, 745, with ??max at 630 nm being the strongest. These emission bands are well correlated with trace quantities of Sn, In, Cu and Mn activators. Sphalerite from the famous Ogdensburg and Franklin mines exhibited brilliant deep blue and orange CL colours and the blue CL may be related to Se. Cathodoluminescence behaviour of sphalerite serves to characterise ore types and help detect technologically important trace elements.

Flattening and surface-brightness of the fast-rotating star δ Persei with the visible VEGA/CHARA interferometer

NASA Astrophysics Data System (ADS)

Challouf, M.; Nardetto, N.; Domiciano de Souza, A.; Mourard, D.; Tallon-Bosc, I.; Aroui, H.; Farrington, C.; Ligi, R.; Meilland, A.; Mouelhi, M.

2017-08-01

Context. Rapid rotation is a common feature for massive stars, with important consequences on their physical structure, flux distribution and evolution. Fast-rotating stars are flattened and show gravity darkening (non-uniform surface intensity distribution). Another important and less studied impact of fast-rotation in early-type stars is its influence on the surface brightness colour relation (hereafter SBCR), which could be used to derive the distance of eclipsing binaries. Aims: The purpose of this paper is to determine the flattening of the fast-rotating B-type star δ Per using visible long-baseline interferometry. A second goal is to evaluate the impact of rotation and gravity darkening on the V - K colour and surface brightness of the star. Methods: The B-type star δ Per was observed with the VEGA/CHARA interferometer, which can measure spatial resolutions down to 0.3 mas and spectral resolving power of 5000 in the visible. We first used a toy model to derive the position angle of the rotation axis of the star in the plane of the sky. Then we used a code of stellar rotation, CHARRON, in order to derive the physical parameters of the star. Finally, by considering two cases, a static reference star and our best model of δ Per, we can quantify the impact of fast rotation on the surface brightness colour relation (SBCR). Results: We find a position angle of 23 ± 6 degrees. The polar axis angular diameter of δ Per is θp = 0.544 ± 0.007 mas, and the derived flatness is r = 1.121 ± 0.013. We derive an inclination angle for the star of I = 85+ 5-20 degrees and a projected rotation velocity Vsini = 175+ 8-11 km s-1 (or 57% of the critical velocity). We find also that the rotation and inclination angle of δ Per keeps the V - K colour unchanged while it decreasing its surface-brightness by about 0.05 mag. Conclusions: Correcting the impact of rotation on the SBCR of early-type stars appears feasible using visible interferometry and dedicated models.

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.

Standardised (plain) cigarette packaging increases attention to both text-based and graphical health warnings: experimental evidence.

PubMed

Shankleman, M; Sykes, C; Mandeville, K L; Di Costa, S; Yarrow, K

2015-01-01

To investigate whether standardised cigarette packaging increases the time spent looking at health warnings, regardless of the format of those warnings. A factorial (two pack styles x three warning types) within-subject experiment, with participants randomised to different orders of conditions, completed at a university in London, UK. Mock-ups of cigarette packets were presented to participants with their branded portion in either standardised (plain) or manufacturer-designed (branded) format. Health warnings were present on all packets, representing all three types currently in use in the UK: black & white text, colour text, or colour images with accompanying text. Gaze position was recorded using a specialised eye tracker, providing the main outcome measure, which was the mean proportion of a five-second viewing period spent gazing at the warning-label region of the packet. An opportunity sample of 30 (six male, mean age = 23) young adults met the following inclusion criteria: 1) not currently a smoker; 2) <100 lifetime cigarettes smoked; 3) gaze position successfully tracked for > 50% viewing time. These participants spent a greater proportion of the available time gazing at the warning-label region when the branded section of the pack was standardised (following current Australian guidelines) rather than containing the manufacturer's preferred design (mean difference in proportions = 0.078, 95% confidence interval 0.049 to 0.106, p < 0.001). There was no evidence that this effect varied based on the type of warning label (black & white text vs. colour text vs. colour image & text; interaction p = 0.295). During incidental viewing of cigarette packets, young adult never-smokers are likely to spend more time looking at health warnings if manufacturers are compelled to use standardised packaging, regardless of the warning design. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Patterns and Drivers of Egg Pigment Intensity and Colour Diversity in the Ocean: A Meta-Analysis of Phylum Echinodermata.

PubMed

Montgomery, E M; Hamel, J-F; Mercier, A

Egg pigmentation is proposed to serve numerous ecological, physiological, and adaptive functions in egg-laying animals. Despite the predominance and taxonomic diversity of egg layers, syntheses reviewing the putative functions and drivers of egg pigmentation have been relatively narrow in scope, centring almost exclusively on birds. Nonvertebrate and aquatic species are essentially overlooked, yet many of them produce maternally provisioned eggs in strikingly varied colours, from pale yellow to bright red or green. We explore the ways in which these colour patterns correlate with behavioural, morphological, geographic and phylogenetic variables in extant classes of Echinodermata, a phylum that has close phylogenetic ties with chordates and representatives in nearly all marine environments. Results of multivariate analyses show that intensely pigmented eggs are characteristic of pelagic or external development whereas pale eggs are commonly brooded internally. Of the five egg colours catalogued, orange and yellow are the most common. Yellow eggs are a primitive character, associated with all types of development (predominant in internal brooders), whereas green eggs are always pelagic, occur in the most derived orders of each class and are restricted to the Indo-Pacific Ocean. Orange eggs are geographically ubiquitous and may represent a 'universal' egg pigment that functions well under a diversity of environmental conditions. Finally, green occurs chiefly in the classes Holothuroidea and Ophiuroidea, orange in Asteroidea, yellow in Echinoidea, and brown in Holothuroidea. By examining an unprecedented combination of egg colours/intensities and reproductive strategies, this phylum-wide study sheds new light on the role and drivers of egg pigmentation, drawing parallels with theories developed from the study of more derived vertebrate taxa. The primary use of pigments (of any colour) to protect externally developing eggs from oxidative damage and predation is supported by the comparatively pale colour of equally large, internally brooded eggs. Secondarily, geographic location drives the evolution of egg colour diversity, presumably through the selection of better-adapted, more costly pigments in response to ecological pressure. © 2017 Elsevier Ltd. All rights reserved.

Isolation and antisense suppression of flavonoid 3', 5'-hydroxylase modifies flower pigments and colour in cyclamen.

PubMed

Boase, Murray R; Lewis, David H; Davies, Kevin M; Marshall, Gayle B; Patel, Deepa; Schwinn, Kathy E; Deroles, Simon C

2010-06-13

Cyclamen is a popular and economically significant pot plant crop in several countries. Molecular breeding technologies provide opportunities to metabolically engineer the well-characterized flavonoid biosynthetic pathway for altered anthocyanin profile and hence the colour of the flower. Previously we reported on a genetic transformation system for cyclamen. Our aim in this study was to change pigment profiles and flower colours in cyclamen through the suppression of flavonoid 3', 5'-hydroxylase, an enzyme in the flavonoid pathway that plays a determining role in the colour of anthocyanin pigments. A full-length cDNA putatively identified as a F3'5'H (CpF3'5'H) was isolated from cyclamen flower tissue. Amino acid and phylogeny analyses indicated the CpF3'5'H encodes a F3'5'H enzyme. Two cultivars of minicyclamen were transformed via Agrobacterium tumefaciens with an antisense CpF3'5'H construct. Flowers of the transgenic lines showed modified colour and this correlated positively with the loss of endogenous F3'5'H transcript. Changes in observed colour were confirmed by colorimeter measurements, with an overall loss in intensity of colour (C) in the transgenic lines and a shift in hue from purple to red/pink in one cultivar. HPLC analysis showed that delphinidin-derived pigment levels were reduced in transgenic lines relative to control lines while the percentage of cyanidin-derived pigments increased. Total anthocyanin concentration was reduced up to 80% in some transgenic lines and a smaller increase in flavonol concentration was recorded. Differences were also seen in the ratio of flavonol types that accumulated. To our knowledge this is the first report of genetic modification of the anthocyanin pathway in the commercially important species cyclamen. The effects of suppressing a key enzyme, F3'5'H, were wide ranging, extending from anthocyanins to other branches of the flavonoid pathway. The results illustrate the complexity involved in modifying a biosynthetic pathway with multiple branch points to different end products and provides important information for future flower colour modification experiments in cyclamen.

Isolation and antisense suppression of flavonoid 3', 5'-hydroxylase modifies flower pigments and colour in cyclamen

PubMed Central

2010-01-01

Background Cyclamen is a popular and economically significant pot plant crop in several countries. Molecular breeding technologies provide opportunities to metabolically engineer the well-characterized flavonoid biosynthetic pathway for altered anthocyanin profile and hence the colour of the flower. Previously we reported on a genetic transformation system for cyclamen. Our aim in this study was to change pigment profiles and flower colours in cyclamen through the suppression of flavonoid 3', 5'-hydroxylase, an enzyme in the flavonoid pathway that plays a determining role in the colour of anthocyanin pigments. Results A full-length cDNA putatively identified as a F3'5'H (CpF3'5'H) was isolated from cyclamen flower tissue. Amino acid and phylogeny analyses indicated the CpF3'5'H encodes a F3'5'H enzyme. Two cultivars of minicyclamen were transformed via Agrobacterium tumefaciens with an antisense CpF3'5'H construct. Flowers of the transgenic lines showed modified colour and this correlated positively with the loss of endogenous F3'5'H transcript. Changes in observed colour were confirmed by colorimeter measurements, with an overall loss in intensity of colour (C) in the transgenic lines and a shift in hue from purple to red/pink in one cultivar. HPLC analysis showed that delphinidin-derived pigment levels were reduced in transgenic lines relative to control lines while the percentage of cyanidin-derived pigments increased. Total anthocyanin concentration was reduced up to 80% in some transgenic lines and a smaller increase in flavonol concentration was recorded. Differences were also seen in the ratio of flavonol types that accumulated. Conclusion To our knowledge this is the first report of genetic modification of the anthocyanin pathway in the commercially important species cyclamen. The effects of suppressing a key enzyme, F3'5'H, were wide ranging, extending from anthocyanins to other branches of the flavonoid pathway. The results illustrate the complexity involved in modifying a biosynthetic pathway with multiple branch points to different end products and provides important information for future flower colour modification experiments in cyclamen. PMID:20540805

47 CFR 73.314 - Field strength measurements.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., such as topography, height and types of vegetation, buildings, obstacles, weather, and other local... the approximate time of measurement, weather, topography, overhead wiring, heights and types of...

47 CFR 73.314 - Field strength measurements.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., such as topography, height and types of vegetation, buildings, obstacles, weather, and other local... the approximate time of measurement, weather, topography, overhead wiring, heights and types of...

47 CFR 73.314 - Field strength measurements.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., such as topography, height and types of vegetation, buildings, obstacles, weather, and other local... the approximate time of measurement, weather, topography, overhead wiring, heights and types of...

47 CFR 73.314 - Field strength measurements.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., such as topography, height and types of vegetation, buildings, obstacles, weather, and other local... the approximate time of measurement, weather, topography, overhead wiring, heights and types of...

Transmission electron microscopy for archaeo-materials research: Nanoparticles in glazes and red/yellow glass and inorganic pigments in painted context

NASA Astrophysics Data System (ADS)

Fredrickx, Peggy

2004-10-01

This dissertation addresses the application of Transmission Electron Microscopy (TEM) to historic objects, concentrating on colour-causing nanoparticles in vitreous materials and pigments with the focus on substrates in lake pigments used in thin glaze layers, and on manuscript illustrations. TEM is well suited for archaeometry: it gives chemical elemental information, imaging and diffraction information and the amount of material needed is minimal. Sample preparation techniques suitable for historic materials are discussed. Nanoparticles can be incorporated in glass through staining. Yellow coloured glass plates contain Ag particles. Baking temperatures and different Ag-salts determine the density of the nanoparticles. Dense layers cause more saturated colours. Red glass plates can be obtained by staining with Cu-salts. Metallic Cu particles have a diameter of about 24 nm. Comparison with XRF results suggests that often a combination of Cu and Ag was used for warmer colours. Red glass can be "flashed" to the substrate glass. Then, the colour is also caused by metallic Cu particles. The red layer often displays a band structure of stacked red and transparent bands. In the transparent bands, no nanoparticles have been found. In lustre-ware, Ag and metallic Cu occur. Their distribution throughout the material determines the colour of the fragment. In both there is a dense top layer with particles of sizes smaller than 15 nm. If this top layer consists of Ag particles, the resulting colour is golden. In one sample, under this top layer the amount of Cu particles increases. This underlying layer causes the colour to redden. Particles are mainly between 5 and 15 nm in diameter. Using reconstructions, it has been demonstrated that TEM can detect and identify a stacking of thin layers in parchment decorations. A pink powder sample from Pompeii consists of a basis of allophane type clay. The lake substrates consist of Al, O, S and their amorphous structure does not seem to be noticeably changed by the addition of organic colourants. Hydrocerussite crystals (i.e. the main component of lead white) have been added to some historic glaze layers. Further it was confirmed that sometimes crystalline CaSO4 particles were added to lakes.

A comparison of two-coloured filter systems for treating visual reading difficulties.

PubMed

Hall, Roger; Ray, Nicola; Harries, Priscilla; Stein, John

2013-01-01

Visual disturbances that make it difficult to read text are often termed "visual stress". Coloured filters in spectacles may help some children overcome reading problems that are often caused by visual stress. It has been suggested that for optimal effect each child requires an individually prescribed colour for each eye, as determined in systems such as the "Harris Foundation" coloured filters. Alternatively, it has been argued that only blue or yellow filters, as used in the "Dyslexia Research Trust" (DRT) filter system, are necessary to affect the underlying physiology. A randomised, double blind trial with 73 delayed readers, was undertaken to compare changes in reading and spelling as well as irregular and non-word reading skills after 3 months of wearing either the Harris or the DRT filters. Reading improved significantly after wearing either type of filter (t = -8.4, p < 0.01), with 40% of the children improving their reading age by 6 months or more during the 3 month trial. However, spelling ability (t = 2.1, p = 0.05) and non-word reading (f = 4.7, p < 0.05) improved significantly more with the DRT than with the Harris filters. Education and rehabilitation professionals should therefore, consider coloured filters as an effective intervention for delayed readers experiencing visual stress. Any disability that impacts on a child's capacity to read has serious implications for academic development as well as the ability to participate independently in activities of daily living. One reading disability, generally termed "visual stress", is related to visual disturbances that make it difficult to read text. This research demonstrates the beneficial use of coloured filters for promoting visual reading capacity for children with visual stress. Professionals who are involved in the needs of children with reading delay, may like to consider the benefits that coloured filters can afford children with visual reading problems.

Water Discolouration Risk Mapping: a Regionally Mapped Model

NASA Astrophysics Data System (ADS)

Kirkby, M.; Arrell, K.; McDonald, A.; Tillotson, M.; Foulger, M.; Walker, A.

2006-12-01

Discolouration in catchment waters is caused by the release through oxidation, warming and biological decomposition of the soil. Catchments that yield highly discoloured waters not only increase treatment and sludge disposal costs but also risk compliance failures and increase the potential for Trihalomethane (THM) production; an unwanted byproduct of water chlorination. Therefore it is important for water companies to quantify and map water discolouration risk within their catchments to guide surveillance and intervention strategies. Yorkshire Water Services derives significant water resources from upland catchments. These catchments continue to produce increasing quantities of discolouration which are problematic and costly to treat. The company is taking several initiatives to manage colour. Traditional water colour studies tend to be restricted in scale and are unable to make conclusions about water colour production within a region. Sensitivities of water colour production to feedbacks and interactions between multiple factors also remains largely unquantified. This research addressed these limitations and mapped water discolouration risk for the Yorkshire Water area. Many factors are believed to influence colour production within a catchment. These are divided into two groups: dynamic factors for example, drought frequency, duration and severity or changes in the levels of acid precipitation; and static factors that are catchment specific, such as land management techniques, slope, soil type and erosion. A map of discolouration risk was created by sourcing and combining data for each of these variables. Data were categorised as either factors or constraints on water colour production and combined in a series of weighted overlays within a GIS, reflecting recent research on the processes leading to water colour production. Resulting risk maps identified a large variability in risk throughout study catchments. Analyses were also undertaken to examine the sensitivities of these distributions to changing land management techniques which will in turn inform Yorkshire Water of potential strategies towards the reduction of water discolouration.

A comparison of two-coloured filter systems for treating visual reading difficulties

PubMed Central

Hall, Roger; Ray, Nicola; Harries, Priscilla

2013-01-01

Purpose Visual disturbances that make it difficult to read text are often termed “visual stress”. Coloured filters in spectacles may help some children overcome reading problems that are often caused by visual stress. It has been suggested that for optimal effect each child requires an individually prescribed colour for each eye, as determined in systems such as the “Harris Foundation” coloured filters. Alternatively, it has been argued that only blue or yellow filters, as used in the “Dyslexia Research Trust” (DRT) filter system, are necessary to affect the underlying physiology. Method A randomised, double blind trial with 73 delayed readers, was undertaken to compare changes in reading and spelling as well as irregular and non-word reading skills after 3 months of wearing either the Harris or the DRT filters. Results Reading improved significantly after wearing either type of filter (t = −8.4, p < 0.01), with 40% of the children improving their reading age by 6 months or more during the 3 month trial. However, spelling ability (t = 2.1, p = 0.05) and non-word reading (f = 4.7, p < 0.05) improved significantly more with the DRT than with the Harris filters. Conclusion Education and rehabilitation professionals should therefore, consider coloured filters as an effective intervention for delayed readers experiencing visual stress. Implications for Rehabilitation Any disability that impacts on a child’s capacity to read has serious implications for academic development as well as the ability to participate independently in activities of daily living. One reading disability, generally termed “visual stress”, is related to visual disturbances that make it difficult to read text. This research demonstrates the beneficial use of coloured filters for promoting visual reading capacity for children with visual stress. Professionals who are involved in the needs of children with reading delay, may like to consider the benefits that coloured filters can afford children with visual reading problems. PMID:23627538

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.

Improving ergonomics in milking parlors: empirical findings for optimal working heights in five milking parlor types.

PubMed

Cockburn, M; Savary, P; Kauke, M; Schick, M; Hoehne-Hückstädt, U; Hermanns, I; Ellegast, R

2015-02-01

Milking postures have shifted from seated milking in tethered stalls to milking in a standing position in parlors. However, the musculoskeletal workload of dairy farmers remains high. Previous studies have shown that different working heights affect ergonomics, but they could not objectively evaluate and quantify the workload. The aim of the present study was to assess the effect of working height in different milking parlor types on the milker's workload during the task of attaching milking clusters. Computer-assisted recording and long-term analysis of movements were used to record positions of joints and body regions while performing certain tasks in terms of angular degrees of joints (ADJ) according to the neutral zero method. The 5th, 50th, and 95th percentiles described the distribution of angular degree values measured for each joint. The ADJ were evaluated according to international standards and other scientific literature on the issue to assess the muscular load. The workload was compared between 5 parlor types (auto tandem, herringbone 30°, herringbone 50°, parallel, and rotary) on 15 farms with 2 subjects per parlor and 1 milking period per subject. The working height was defined as a coefficient based on the milker's body height, the floor level, and the cow's udder height. The data recorded during the attachment task were analyzed using generalized linear mixed-effects models taking into account the hierarchical experimental design. The results indicated that the interaction of the cow's udder height, the milker's body height, and the parlor type had a larger effect on ergonomics than each parameter had independently. The interaction was significant in at least 1 of the 3 percentiles in 28 out of 31 ADJ. The postural differences between parlor types, however, were minor. A milking health formula was created to calculate the ideal depth of pit by considering the parlor type, the milker's height, and the mean herd udder height. This formula can be used to develop individual recommendations for future parlor construction. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Prediction of height increment for models of forest growth

Treesearch

Albert R. Stage

1975-01-01

Functional forms of equations were derived for predicting 10-year periodic height increment of forest trees from height, diameter, diameter increment, and habitat type. Crown ratio was considered as an additional variable for prediction, but its contribution was negligible. Coefficients of the function were estimated for 10 species of trees growing in 10 habitat types...

Early evolution of multifocal optics for well-focused colour vision in vertebrates.

PubMed

Gustafsson, O S E; Collin, S P; Kröger, R H H

2008-05-01

Jawless fishes (Agnatha; lampreys and hagfishes) most closely resemble the earliest stage in vertebrate evolution and lamprey-like animals already existed in the Lower Cambrian [about 540 million years ago (MYA)]. Agnathans are thought to have separated from the main vertebrate lineage at least 500 MYA. Hagfishes have primitive eyes, but the eyes of adult lampreys are well-developed. The southern hemisphere lamprey, Geotria australis, possesses five types of opsin genes, three of which are clearly orthologous to the opsin genes of jawed vertebrates. This suggests that the last common ancestor of all vertebrate lineages possessed a complex colour vision system. In the eyes of many bony fishes and tetrapods, well-focused colour images are created by multifocal crystalline lenses that compensate for longitudinal chromatic aberration. To trace the evolutionary origins of multifocal lenses, we studied the optical properties of the lenses in four species of lamprey (Geotria australis, Mordacia praecox, Lampetra fluviatilis and Petromyzon marinus), with representatives from all three of the extant lamprey families. Multifocal lenses are present in all lampreys studied. This suggests that the ability to create well-focused colour images with multifocal optical systems also evolved very early.

Oxidation of edible animal fats. Comparison of the performance of different quantification methods and of a proposed new semi-objective colour scale-based method.

PubMed

Méndez-Cid, Francisco J; Lorenzo, José M; Martínez, Sidonia; Carballo, Javier

2017-02-15

The agreement among the results determined for the main parameters used in the evaluation of the fat auto-oxidation was investigated in animal fats (butter fat, subcutaneous pig back-fat and subcutaneous ham fat). Also, graduated colour scales representing the colour change during storage/ripening were developed for the three types of fat, and the values read in these scales were correlated with the values observed for the different parameters indicating fat oxidation. In general good correlation among the values of the different parameters was observed (e.g. TBA value correlated with the peroxide value: r=0.466 for butter and r=0.898 for back-fat). A reasonable correlation was observed between the values read in the developed colour scales and the values for the other parameters determined (e.g. values of r=0.320 and r=0.793 with peroxide value for butter and back-fat, respectively, and of r=0.767 and r=0.498 with TBA value for back-fat and ham fat, respectively). Copyright © 2016 Elsevier Ltd. All rights reserved.

Efficient detection of wound-bed and peripheral skin with statistical colour models.

PubMed

Veredas, Francisco J; Mesa, Héctor; Morente, Laura

2015-04-01

A pressure ulcer is a clinical pathology of localised damage to the skin and underlying tissue caused by pressure, shear or friction. Reliable diagnosis supported by precise wound evaluation is crucial in order to success on treatment decisions. This paper presents a computer-vision approach to wound-area detection based on statistical colour models. Starting with a training set consisting of 113 real wound images, colour histogram models are created for four different tissue types. Back-projections of colour pixels on those histogram models are used, from a Bayesian perspective, to get an estimate of the posterior probability of a pixel to belong to any of those tissue classes. Performance measures obtained from contingency tables based on a gold standard of segmented images supplied by experts have been used for model selection. The resulting fitted model has been validated on a training set consisting of 322 wound images manually segmented and labelled by expert clinicians. The final fitted segmentation model shows robustness and gives high mean performance rates [(AUC: .9426 (SD .0563); accuracy: .8777 (SD .0799); F-score: 0.7389 (SD .1550); Cohen's kappa: .6585 (SD .1787)] when segmenting significant wound areas that include healing tissues.

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.

Modification of flower colour by suppressing β-ring carotene hydroxylase genes in Oncidium.

PubMed

Wang, H-M; To, K-Y; Lai, H-M; Jeng, S-T

2016-03-01

Oncidium 'Gower Ramsey' (Onc. GR) is a popular cut flower, but its colour is limited to bright yellow. The β-ring carotene hydroxylase (BCH2) gene is involved in carotenoid biogenesis for pigment formation. However, the role of BCH2 in Onc. GR is poorly understood. Here, we investigated the functions of three BCH2 genes, BCH-A2, BCH-B2 and BCH-C2 isolated from Onc. GR, to analyse their roles in flower colour. RT-PCR expression profiling suggested that BCH2 was mainly expressed in flowers. The expression of BCH-B2 remained constant while that of BCH-A2 gradually decreased during flower development. Using Agrobacterium tumefaciens to introduce BCH2 RNA interference (RNAi), we created transgenic Oncidium plants with down-regulated BCH expression. In the transgenic plants, flower colour changed from the bright yellow of the wild type to light and white-yellow. BCH-A2 and BCH-B2 expression levels were significantly reduced in the transgenic flower lips, which make up the major portion of the Oncidium flower. Sectional magnification of the flower lip showed that the amount of pigmentation in the papillate cells of the adaxial epidermis was proportional to the intensity of yellow colouration. HPLC analyses of the carotenoid composition of the transgenic flowers suggested major reductions in neoxanthin and violaxanthin. In conclusion, BCH2 expression regulated the accumulation of yellow pigments in the Oncidium flower, and the down-regulation of BCH-A2 and BCH-B2 changed the flower colour from bright yellow to light and white-yellow. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

The utility of ultrasound superb microvascular imaging for evaluation of breast tumour vascularity: comparison with colour and power Doppler imaging regarding diagnostic performance.

PubMed

Park, A Y; Seo, B K; Woo, O H; Jung, K S; Cho, K R; Park, E K; Cha, S H; Cha, J

2018-03-01

To investigate the utility of superb microvascular imaging (SMI) for evaluating the vascularity of breast masses in comparison with colour or power Doppler ultrasound (US) and the effect on diagnostic performance. A total of 191 biopsy-proven masses (99 benign and 92 malignant) in 166 women with greyscale, colour Doppler, power Doppler, and SMI images were enrolled in this retrospective study. Three radiologists analysed the vascular images using a three-factor scoring system to evaluate the number, morphology, and distribution of tumour vessels. They assessed the Breast Imaging-Reporting and Data System categories for greyscale US alone and combinations of greyscale US and each type of vascular US. The Kruskal-Wallis test was performed and the area under the receiver-operating characteristic curve (AUC) measured. On SMI, vascular scores were compared between benign and malignant masses and the optimal cut-off value for the overall score was determined. SMI showed higher vascular scores than colour or power Doppler US and malignant masses had higher scores than benign masses (p<0.001). The diagnostic performance of the combination of greyscale US and SMI was higher than those of greyscale US alone and greyscale and colour or power Doppler US (AUC, 0.815 versus 0.774, 0.789, 0.791; p<0.001). The optimal cut-off value of the overall vascular score was 5 with a sensitivity of 82.3% and a specificity of 65.3% (AUC, 0.808). SMI is superior to colour or power Doppler US for characterising the vascularity in breast masses and improving diagnostic performance. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

FC colour images of dwarf planet Ceres reveal a complicated geological history

NASA Astrophysics Data System (ADS)

Nathues, A.; Hoffmann, M.; Platz, T.; Thangjam, G. S.; Cloutis, E. A.; Reddy, V.; Le Corre, L.; Li, J.-Y.; Mengel, K.; Rivkin, A.; Applin, D. M.; Schaefer, M.; Christensen, U.; Sierks, H.; Ripken, J.; Schmidt, B. E.; Hiesinger, H.; Sykes, M. V.; Sizemore, H. G.; Preusker, F.; Russell, C. T.

2016-12-01

The dwarf planet Ceres (equatorial diameter 963km) is the largest object that has remained in the main asteroid belt (Russell and Raymond, 2012), while most large bodies have been destroyed or removed by dynamical processes (Petit et al. 2001; Minton and Malhotra, 2009). Pre-Dawn investigations (McCord and Sotin, 2005; Castillo-Rogez and McCord, 2010; Castillo-Rogez et al., 2011) suggest that Ceres is a thermally evolved, but still volatile-rich body with potential geological activity, that was never completely molten, but possibly differentiated into a rocky core, an ice-rich mantle, and may contain remnant internal liquid water. Thermal alteration should contribute to producing a (dark) carbonaceous chondritic-like surface (McCord and Sotin, 2005; Castillo-Rogez and McCord, 2010; Castillo-Rogez et al., 2011; Nathues et al., 2015) containing ammoniated phyllosilicates (King et al., 1992; De Sanctis et al., 2015 and 2016). Here we show and analyse global contrast-rich colour mosaics, derived from a camera on-board Dawn at Ceres (Russell et al., 2016). Colours are unexpectedly more diverse on global scale than anticipated by Hubble Space Telescope (Li et al., 2006) and ground-based observations (Reddy et al. 2015). Dawn data led to the identification of five major colour units. The youngest units identified by crater counting, termed bright and bluish units, are exclusively found at equatorial and intermediate latitudes. We identified correlations between the distribution of the colour units, crater size, and formation age, inferring a crustal stratigraphy. Surface brightness and spectral properties are not correlated. The youngest surface features are the bright spots at crater Occator ( Ø 92km). Their colour spectra are highly consistent with the presence of carbonates while most of the remaining surface resembles modifications of various types of ordinary carbonaceous chondrites.

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

Shedding light on the Type Ia supernova extinction puzzle: dust location found

NASA Astrophysics Data System (ADS)

Bulla, M.; Goobar, A.; Dhawan, S.

2018-06-01

The colour evolution of reddened Type Ia supernovae can place strong constraints on the location of dust and help address the question of whether the observed extinction stems from the interstellar medium or from circumstellar material surrounding the progenitor. Here we analyse BV photometry of 48 reddened Type Ia supernovae from the literature and estimate the dust location from their B - V colour evolution. We find a time-variable colour excess E(B - V) for 15 supernovae in our sample and constrain dust to distances between 0.013 and 45 pc (4 × 1016 - 1020 cm). For the remaining supernovae, we obtain a constant E(B - V) evolution and place lower limits on the dust distance from the explosion. In all the 48 supernovae, the inferred dust location is compatible with an interstellar origin for the extinction. This is corroborated by the observation that supernovae with relatively nearby dust (≲ 1 pc) are located close to the center of their host galaxy, in high-density dusty regions where interactions between the supernova radiation and interstellar clouds close by are likely to occur. For supernovae showing time-variable E(B - V), we identify a potential preference for low RV values, unusually strong sodium absorption and blue-shifted and time-variable absorption features. Within the interstellar framework, this brings evidence to a proposed scenario where cloud-cloud collisions induced by the supernova radiation pressure can shift the grain size distribution to smaller values and enhance the abundance of sodium in the gaseous phase.

Flexible and inflexible response components: a Stroop study with typewritten output.

PubMed

Damian, Markus F; Freeman, Norman H

2008-05-01

Two experiments were directed at investigating the relationship between response selection and execution in typewriting, and specifically the extent to which concurrent processing takes place. In a Stroop paradigm adapted from [Logan, G. D., & Zbrodoff, N. J. (1998). Stroop-type interference: Congruity effects in colour naming with typewritten responses. Journal of Experimental Psychology: Human Perception and Performance, 24, 978-992], participants typed the names of colour patches with incongruent, congruent, or neutral distractors presented at various stimulus-onset asynchronies. Experiment 1 showed Stroop interference and facilitation for initial keystroke latencies and errors, contrasting with response durations (a measure of response execution) being unaffected by Stroop manipulation. Experiment 2 showed that all three measures were responsive to time pressure; again, Stroop effects were confined to latencies and errors only. The observation that response duration is both flexible under time pressure and protected from response competition, may imply either that response execution is structurally segregated from earlier processing stages, or that encapsulation develops during the acquisition of typing skills.

Transformations between the 2MASS, SDSS, and BV I photometric systems for late-type giants

NASA Astrophysics Data System (ADS)

Yaz, E.; Bilir, S.; Karaali, S.; Ak, S.; Coşkunoğlu, B.; Cabrera-Lavers, A.

2010-08-01

We present colour transformations from Two Micron All Sky Survey (2MASS) photometric system to Johnson-Cousins system and to Sloan Digital Sky Survey (SDSS) system for late-type giants and vice versa. The giant star sample was formed using surface gravity constraints ({2 < log g ≤ 3}) to Cayrel de Strobel et al.' s (2001) spectroscopic catalogue. 2MASS, SDSS and Johnson-Cousins photometric data was taken from \\cite{Cu03}, \\cite{Ofek08}, and \\cite{vanLeeuwen2007}, respectively. The final sample was refined applying the following steps: (1) the data were dereddened, (2) the sample stars selected are of the highest photometric quality. We give two-colour dependent transformations as a function of metallicity as well as independent of metallicity. The transformations provide absolute magnitudes and distance determinations which can be used in space density evaluations at relatively short distances where some or all of the SDSS magnitudes of late-type giants are saturated.

Weighted analysis of paired microarray experiments.

PubMed

Kristiansson, Erik; Sjögren, Anders; Rudemo, Mats; Nerman, Olle

2005-01-01

In microarray experiments quality often varies, for example between samples and between arrays. The need for quality control is therefore strong. A statistical model and a corresponding analysis method is suggested for experiments with pairing, including designs with individuals observed before and after treatment and many experiments with two-colour spotted arrays. The model is of mixed type with some parameters estimated by an empirical Bayes method. Differences in quality are modelled by individual variances and correlations between repetitions. The method is applied to three real and several simulated datasets. Two of the real datasets are of Affymetrix type with patients profiled before and after treatment, and the third dataset is of two-colour spotted cDNA type. In all cases, the patients or arrays had different estimated variances, leading to distinctly unequal weights in the analysis. We suggest also plots which illustrate the variances and correlations that affect the weights computed by our analysis method. For simulated data the improvement relative to previously published methods without weighting is shown to be substantial.

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.

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.

Incidental learning of probability information is differentially affected by the type of visual working memory representation.

PubMed

van Lamsweerde, Amanda E; Beck, Melissa R

2015-12-01

In this study, we investigated whether the ability to learn probability information is affected by the type of representation held in visual working memory. Across 4 experiments, participants detected changes to displays of coloured shapes. While participants detected changes in 1 dimension (e.g., colour), a feature from a second, nonchanging dimension (e.g., shape) predicted which object was most likely to change. In Experiments 1 and 3, items could be grouped by similarity in the changing dimension across items (e.g., colours and shapes were repeated in the display), while in Experiments 2 and 4 items could not be grouped by similarity (all features were unique). Probability information from the predictive dimension was learned and used to increase performance, but only when all of the features within a display were unique (Experiments 2 and 4). When it was possible to group by feature similarity in the changing dimension (e.g., 2 blue objects appeared within an array), participants were unable to learn probability information and use it to improve performance (Experiments 1 and 3). The results suggest that probability information can be learned in a dimension that is not explicitly task-relevant, but only when the probability information is represented with the changing dimension in visual working memory. (c) 2015 APA, all rights reserved).

Biomedical waste disposal: A systems analysis

PubMed Central

Jindal, A.K.; Gupta, Arun; Grewal, V.S.; Mahen, Ajoy

2012-01-01

Background In view of the contemporary relevance of BMW Management, a system analysis of BMW management was conducted to ascertain the views of Service hospitals/HCE's on the current system in BMW management in-vogue; to know the composition and quantity of waste generated; to get information on equipment held & equipment required and to explore the possibility of outsourcing, its relevance and feasibility. Methods A qualitative study in which various stake holders in BMW management were studied using both primary (Observation, In-depth Interview of Key Personnel, Group Discussions: and user perspective survey) and secondary data. Results All the stake holders were of the opinion that where ever possible outsourcing should be explored as a viable method of BMW disposal. Waste generated in Colour code Yellow (Cat 1,2,3,5,6) ranged from 64.25 to 27.345 g/day/bed; in Colour code Red (Cat 7) from 19.37 to 10.97 g/day/bed and in Colour code Blue (Cat 4) from 3.295 to 3.82 g/day/bed in type 1 hospitals to type 5 hospitals respectively. Conclusion Outsourcing should be explored as a viable method of BMW disposal, were there are government approved local agencies. Facilities authorized by the Prescribed Authority should be continued and maintained where outsourcing is not feasible. PMID:24600142

Pressure-temperature-fluid constraints for the Emmaville-Torrington emerald deposit, New South Wales, Australia: Fluid inclusion and stable isotope studies

NASA Astrophysics Data System (ADS)

Loughrey, Lara; Marshall, Dan; Jones, Peter; Millsteed, Paul; Main, Arthur

2012-06-01

The Emmaville-Torrington emeralds were first discovered in 1890 in quartz veins hosted within a Permian metasedimentary sequence, consisting of meta-siltstones, slates and quartzites intruded by pegmatite and aplite veins from the Moule Granite. The emerald deposit genesis is consistent with a typical granite-related emerald vein system. Emeralds from these veins display colour zonation alternating between emerald and clear beryl. Two fluid inclusion types are identified: three-phase (brine+vapour+halite) and two-phase (vapour+liquid) fluid inclusions. Fluid inclusion studies indicate the emeralds were precipitated from saline fluids ranging from approximately 33 mass percent NaCl equivalent. Formational pressures and temperatures of 350 to 400 °C and approximately 150 to 250 bars were derived from fluid inclusion and petrographic studies that also indicate emerald and beryl precipitation respectively from the liquid and vapour portions of a two-phase (boiling) system. The distinct colour zonations observed in the emerald from these deposits is the first recorded emerald locality which shows evidence of colour variation as a function of boiling. The primary three-phase and primary two-phase FITs are consistent with alternating chromium-rich `striped' colour banding. Alternating emerald zones with colourless beryl are due to chromium and vanadium partitioning in the liquid portion of the boiling system. The chemical variations observed at Emmaville-Torrington are similar to other colour zoned emeralds from other localities worldwide likely precipitated from a boiling system as well.

Phenotypic selection to increase floral scent emission, but not flower size or colour in bee-pollinated Penstemon digitalis.

PubMed

Parachnowitsch, Amy L; Raguso, Robert A; Kessler, André

2012-08-01

Fragrance is a putatively important character in the evolution of flowering plants, but natural selection on scent is rarely studied and thus poorly understood. We characterized floral scent composition and emission in a common garden of Penstemon digitalis from three nearby source populations. We measured phenotypic selection on scent as well as floral traits more frequently examined, such as floral phenology, display size, corolla pigment, and inflorescence height. Scent differed among populations in a common garden, underscoring the potential for scent to be shaped by differential selection pressures. Phenotypic selection on flower number and display size was strong. However, selection favoured scent rather than flower size or colour, suggesting that smelling stronger benefits reproductive success in P. digitalis. Linalool was a direct target of selection and its high frequency in floral-scent bouquets suggests that further studies of both pollinator- and antagonist-mediated selection on this compound would further our understanding of scent evolution. Our results indicate that chemical dimensions of floral display are just as likely as other components to experience selective pressure in a nonspecialized flowering herb. Therefore, studies that integrate visual and chemical floral traits should better reflect the true nature of floral evolutionary ecology. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

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.

Objective assessment of psoriasis erythema for PASI scoring.

PubMed

Ahmad Fadzil, M H; Ihtatho, Dani; Mohd Affandi, Azura; Hussein, S H

2009-01-01

Skin colour is vital information in dermatological diagnosis as it reflects the pathological condition beneath the skin. It is commonly used to indicate the extent of diseases such as psoriasis, which is indicated by the appearance of red plaques. Although there is no cure for psoriasis, there are many treatment modalities to help control the disease. To evaluate treatment efficacy, the current gold standard method, PASI (Psoriasis Area and Severity Index), is used to determine severity of psoriasis lesion. Erythema (redness) is one parameter in PASI and this condition is assessed visually, thus leading to subjective and inconsistent results. Current methods or instruments that assess erythema have limitations, such as being able to measure erythema well for low pigmented skin (fair skin) but not for highly pigmented skin (dark skin) or vice versa. In this work, we proposed an objective assessment of psoriasis erythema for PASI scoring for different (low to highly pigmented) skin types. The colour of psoriasis lesions are initially obtained by using a chromameter giving the values L*, a*, and b* of CIELAB colour space. The L* value is used to classify skin into three categories: low, medium and highly pigmented skin. The lightness difference (DeltaL*), hue difference (Deltah(ab)), chroma (DeltaC*(ab)) between lesions and the surrounding normal skin are calculated and analysed. It is found that the erythema score of a lesion can be distinguished by their Deltah(ab) value within a particular skin type group. References of lesion with different scores are obtained from the selected lesions by two dermatologists. Results based on 38 lesions from 22 patients with various level of skin pigmentation show that PASI erythema score for different skin types i.e. low (fair skin) to highly pigmented (dark skin) skin types can be determined objectively and consistent with dermatology scoring.

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…

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.

Activity of Polish unifloral honeys against pathogenic bacteria and its correlation with colour, phenolic content, antioxidant capacity and other parameters.

PubMed

Kuś, P M; Szweda, P; Jerković, I; Tuberoso, C I G

2016-03-01

The use of honey as an antimicrobial agent gains importance due to often ineffectiveness of conventional treatment. However, activity of honey depends mainly on its botanical and geographical origin. To date, antimicrobial potential of Polish honeys has not yet been entirely investigated. In this study, 37 unifloral samples of 14 honey types (including rare varieties) from Poland were analysed and compared with manuka honey. The most active were cornflower, thyme and buckwheat honeys. Their MICs ranged from 3·12 to 25·00%, (depending on tested micro-organism) and often were lower than for manuka honey. Additionally, colour, antioxidant activity, total phenols, pH and conductivity were assessed and significant correlations (P < 0·05) of MICs with several parameters were found. The most active were darker honeys, with strong yellow colour component, rich in phenolics, with high conductivity and water content. The honey antibacterial properties depended mainly on peroxide mechanism and were vulnerable to excessive heating, but quite stable during storage in cold. A number of honey samples showed potential as effective antimicrobial agents. The observed correlations of MICs and physical-chemical parameters help to understand better the factors impacting the antibacterial activity. Honey is a promising agent in the treatment of non-healing infected wounds. Thirty-seven unifloral samples of 14 honey varieties from Poland were analysed for their antimicrobial activity and compared with manuka honey. Several honey types exert even higher antimicrobial potential and could be introduced to wound therapy. Additionally, positive correlations of the antimicrobial activity were found, especially with yellow colour and could be important in the search and screening of the honey active against Escherichia coli. © 2015 The Society for Applied Microbiology.

UV SEDs of early-type cluster galaxies: a new look at the UV upturn

NASA Astrophysics Data System (ADS)

Ali, S. S.; Bremer, M. N.; Phillipps, S.; De Propris, R.

2018-05-01

Using GALEX, Ultraviolet Optical Telescope (UVOT), and optical photometry, we explore the prevalence and strength of the Ultraviolet (UV) upturn in the spectra of quiescent early-type galaxies in several nearby clusters. Even for galaxies with completely passive optical colours, there is a large spread in vacuum UV colour consistent with almost all having some UV upturn component. Combining GALEX and UVOT data below 3000 Å, we generate for the first time comparatively detailed UV spectral energy distributions for Coma cluster galaxies. Fitting the UV upturn component with a blackbody, 26 of these show a range of characteristic temperatures (10 000-21 000K) for the UV upturn population. Assuming a single temperature to explain GALEX-optical colours could underestimate the fraction of galaxies with UV upturns and mis-classify some as systems with residual star formation. The UV upturn phenomenon is not an exclusive feature found only in giant galaxies; we identify galaxies with similar (or even bluer) FUV - V colours to the giants with upturns over a range of fainter luminosities. The temperature and strength of the UV upturn are correlated with galaxy mass. Under the plausible hypothesis that the sources of the UV upturn are blue horizontal branch stars, the most likely mechanism for this is the presence of a substantial (between 4 per cent and 20 per cent) Helium-rich (Y > 0.3) population of stars in these galaxies, potentially formed at z ˜ 4 and certainly at z > 2; this plausibly sets a lower limit of {˜ } {0.3- 0.8} × 10^{10} M⊙ to the in situ stellar mass of ˜L* galaxies at this redshift.

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.

Galaxy populations in the Antlia cluster - III. Properties of faint early-type galaxies

NASA Astrophysics Data System (ADS)

Smith Castelli, Analía. V.; Cellone, Sergio A.; Faifer, Favio R.; Bassino, Lilia P.; Richtler, Tom; Romero, Gisela A.; Calderón, Juan Pablo; Caso, Juan Pablo

2012-01-01

We present a new analysis of the early-type galaxy population in the central region of the Antlia cluster, focusing on the faint systems such as dwarf ellipticals (dEs) and dwarf spheroidals (dSphs). The colour-magnitude relation (CMR) and the relation between luminosity and mean effective surface brightness for galaxies in the central region of Antlia have been previously studied in Paper I of the present series. Now we confirm 22 early-type galaxies as Antlia members, using Gemini-GMOS and Magellan-MIKE spectra. Among them, 15 are dEs from the FS90 Antlia Group catalogue, two belong to the rare type of compact ellipticals (cEs) and five are new faint dwarfs that had never been catalogued before. In addition, we present 16 newly identified low-surface-brightness galaxy candidates, almost half of them displaying morphologies consistent with being Antlia's counterparts of Local Group dSphs, which extend the faint luminosity limit of our study down to MB=-10.1(BT= 22.6) mag. With these new data, we built an improved CMR in the Washington photometric system, i.e. integrated T1 magnitudes versus (C-T1) colours, which extends ˜4 mag faintwards the limit of spectroscopically confirmed Antlia members. When only confirmed early-type members are considered, this relation extends over 10 mag in luminosity with no apparent change in slope or increase in colour dispersion towards its faint end. The intrinsic colour scatter of the relation is compared with those reported for other clusters of galaxies; we argue that it is likely that the large scatter of the CMR, usually reported at faint magnitudes, is mostly due to photometric errors along with an improper membership/morphological classification. The distinct behaviour of the luminosity versus mean effective surface brightness relation at the bright and faint ends is analysed, while it is confirmed that dE galaxies on the same relation present a very similar effective radius, regardless of their colour. The projected spatial distribution of the member sample confirms the existence of two groups in Antlia, each one dominated by a giant elliptical galaxy and with one cE located close to each giant. Size and position, with respect to massive galaxies, of the dSph candidates are estimated and compared to Local Group counterparts. Based on observations carried out at the Cerro Tololo Inter-American Observatory (Chile), at Las Campanas Observatory (Chile) and at the European Southern Observatory, Paranal (Chile). Also based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministerio da Ciencia e Tecnologia (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

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.

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.

Nucleophilic Addition of Reactive Dyes on Amidoximated Acrylic Fabrics

PubMed Central

El-Shishtawy, Reda M.; El-Zawahry, Manal M.; Abdelghaffar, Fatma; Ahmed, Nahed S. E.

2014-01-01

Seven reactive dyes judiciously selected based on chemical structures and fixation mechanisms were applied at 2% owf of shade on amidoximated acrylic fabrics. Amidoximated acrylic fabric has been obtained by a viable amidoximation process. The dyeability of these fabrics was evaluated with respect to the dye exhaustion, fixation, and colour strength under different conditions of temperature and dyeing time. Nucleophilic addition type reactive dyes show higher colour data compared to nucleophilic substitution ones. FTIR studies further implicate the binding of reactive dyes on these fabrics. A tentative mechanism is proposed to rationalize the high fixation yield obtained using nucleophilic addition type reactive dyes. Also, the levelling and fastness properties were evaluated for all dyes used. Excellent to good fastness and levelling properties were obtained for all samples irrespective of the dye used. The result of investigation offers a new method for a viable reactive dyeing of amidoximated acrylic fabrics. PMID:25258720

Principle component analyses of questionnaires measuring individual differences in synaesthetic phenomenology.

PubMed

Anderson, Hazel P; Ward, Jamie

2015-05-01

Questionnaires have been developed for categorising grapheme-colour synaesthetes into two sub-types based on phenomenology: associators and projectors. The general approach has been to assume a priori the existence of two sub-types on a single dimension (with endpoints as projector and associator) rather than explore, in a data-driven fashion, other possible models. We collected responses from 175 grapheme-colour synaesthetes on two questionnaires, the Illustrated Synaesthetic Experience Questionnaire (Skelton, Ludwig, & Mohr, 2009) and Rouw and Scholte's (2007) Projector-Associator Questionnaire. After Principle Component Analysis both questionnaires were comprised of two factors which coincide with the projector/associator distinction. This suggests that projectors and associators are not opposites of each other, but separate dimensions of experience (e.g. some synaesthetes claim to be both, others claim to be neither). The revised questionnaires provide a useful tool for researchers and insights into the phenomenology of synaesthesia. Copyright © 2015 Elsevier Inc. All rights reserved.

How to perform RT-qPCR accurately in plant species? A case study on flower colour gene expression in an azalea (Rhododendron simsii hybrids) mapping population.

PubMed

De Keyser, Ellen; Desmet, Laurence; Van Bockstaele, Erik; De Riek, Jan

2013-06-24

Flower colour variation is one of the most crucial selection criteria in the breeding of a flowering pot plant, as is also the case for azalea (Rhododendron simsii hybrids). Flavonoid biosynthesis was studied intensively in several species. In azalea, flower colour can be described by means of a 3-gene model. However, this model does not clarify pink-coloration. The last decade gene expression studies have been implemented widely for studying flower colour. However, the methods used were often only semi-quantitative or quantification was not done according to the MIQE-guidelines. We aimed to develop an accurate protocol for RT-qPCR and to validate the protocol to study flower colour in an azalea mapping population. An accurate RT-qPCR protocol had to be established. RNA quality was evaluated in a combined approach by means of different techniques e.g. SPUD-assay and Experion-analysis. We demonstrated the importance of testing noRT-samples for all genes under study to detect contaminating DNA. In spite of the limited sequence information available, we prepared a set of 11 reference genes which was validated in flower petals; a combination of three reference genes was most optimal. Finally we also used plasmids for the construction of standard curves. This allowed us to calculate gene-specific PCR efficiencies for every gene to assure an accurate quantification. The validity of the protocol was demonstrated by means of the study of six genes of the flavonoid biosynthesis pathway. No correlations were found between flower colour and the individual expression profiles. However, the combination of early pathway genes (CHS, F3H, F3'H and FLS) is clearly related to co-pigmentation with flavonols. The late pathway genes DFR and ANS are to a minor extent involved in differentiating between coloured and white flowers. Concerning pink coloration, we could demonstrate that the lower intensity in this type of flowers is correlated to the expression of F3'H. Currently in plant research, validated and qualitative RT-qPCR protocols are still rare. The protocol in this study can be implemented on all plant species to assure accurate quantification of gene expression. We have been able to correlate flower colour to the combined regulation of structural genes, both in the early and late branch of the pathway. This allowed us to differentiate between flower colours in a broader genetic background as was done so far in flower colour studies. These data will now be used for eQTL mapping to comprehend even more the regulation of this pathway.

How to perform RT-qPCR accurately in plant species? A case study on flower colour gene expression in an azalea (Rhododendron simsii hybrids) mapping population

PubMed Central

2013-01-01

Background Flower colour variation is one of the most crucial selection criteria in the breeding of a flowering pot plant, as is also the case for azalea (Rhododendron simsii hybrids). Flavonoid biosynthesis was studied intensively in several species. In azalea, flower colour can be described by means of a 3-gene model. However, this model does not clarify pink-coloration. The last decade gene expression studies have been implemented widely for studying flower colour. However, the methods used were often only semi-quantitative or quantification was not done according to the MIQE-guidelines. We aimed to develop an accurate protocol for RT-qPCR and to validate the protocol to study flower colour in an azalea mapping population. Results An accurate RT-qPCR protocol had to be established. RNA quality was evaluated in a combined approach by means of different techniques e.g. SPUD-assay and Experion-analysis. We demonstrated the importance of testing noRT-samples for all genes under study to detect contaminating DNA. In spite of the limited sequence information available, we prepared a set of 11 reference genes which was validated in flower petals; a combination of three reference genes was most optimal. Finally we also used plasmids for the construction of standard curves. This allowed us to calculate gene-specific PCR efficiencies for every gene to assure an accurate quantification. The validity of the protocol was demonstrated by means of the study of six genes of the flavonoid biosynthesis pathway. No correlations were found between flower colour and the individual expression profiles. However, the combination of early pathway genes (CHS, F3H, F3'H and FLS) is clearly related to co-pigmentation with flavonols. The late pathway genes DFR and ANS are to a minor extent involved in differentiating between coloured and white flowers. Concerning pink coloration, we could demonstrate that the lower intensity in this type of flowers is correlated to the expression of F3'H. Conclusions Currently in plant research, validated and qualitative RT-qPCR protocols are still rare. The protocol in this study can be implemented on all plant species to assure accurate quantification of gene expression. We have been able to correlate flower colour to the combined regulation of structural genes, both in the early and late branch of the pathway. This allowed us to differentiate between flower colours in a broader genetic background as was done so far in flower colour studies. These data will now be used for eQTL mapping to comprehend even more the regulation of this pathway. PMID:23800303

Pre-Activity Modulation of Lower Extremity Muscles Within Different Types and Heights of Deep Jump

PubMed Central

Mrdakovic, Vladimir; Ilic, Dusko B.; Jankovic, Nenad; Rajkovic, Zeljko; Stefanovic, Djordje

2008-01-01

The purpose of this study was to determine modulation of pre- activity related to different types and heights of deep jump. Sixteen male soccer players without experience in deep jumps training (the national competition; 15.0 ± 0.5yrs; weight 61.9 ± 6.1kg; height 1.77 ± 0.07m), who participated in the study, performed three types of deep jump (bounce landing, counter landing, and bounce drop jump) from three different heights (40cm, 60cm, and 80cm). Surface EMG device (1000Hz) was used to estimate muscle activity (maximal amplitude of EMG - AmaxEMG; integral EMG signal - iEMG) of five muscles (mm.gastrocnemii, m.soleus, m.tibialis anterior, m.vastus lateralis) within 150ms before touchdown. All the muscles, except m. gastrocnemius medialis, showed systematic increase in pre-activity when platform height was raised. For most of the lower extremity muscles, the most significant differences were between values of pre-activity obtained for 40 cm and 80 cm platforms. While the amount of muscle pre-activity in deep jumps from the heights above and beneath the optimal one did not differ significantly from that generated in deep jumps from the optimal drop height of 60 cm, the patterns of muscle pre-activity obtained for the heights above the optimal one did differ from those obtained for the optimal drop height. That suggests that deep jumps from the heights above the optimal one do not seem to be an adequate exercise for adjusting muscle activity for the impact. Muscle pre-activity in bounce drop jumps differed significantly from that in counter landing and bounce landing respectively, which should indicate that a higher amount of pre-activity generated during bounce drop jumps was used for performing take-offs. As this study included the subjects who were not familiar with deep jumps training, the prospective studies should reveal the results of athletes with previous experience. Key pointsHeight factor proved to be more relevant for the change in pre-activation level compared to the drop jump type factor.There is evident qualitative difference in pattern of pre-activation from lower and higher drop heights, compared to pattern of pre-activation obtained from optimal drop height.Drop jumps from the heights above the optimal one are not adequate for nicely preparing muscle activity for the impact. PMID:24149460

Improving nutritional status of children with cystic fibrosis at Red Cross War Memorial Children's Hospital.

PubMed

van der Spuy, Dorothy A; Cader, Shihaam; van der Spuy, Gian D; Westwood, Anthony T

2011-05-01

To determine the nutritional status of children attending a cystic fibrosis clinic in a tertiary hospital in South Africa and compare it to previously reported 10-year rates. Weights and heights were measured of 69 (37 male and 32 female) children aged between 1 year and 18 years. Expected weight-for-age, expected height-for-age, expected weight-for-height and body mass index (BMI) were compared with international standards for underweight, stunting, wasting and BMI goal. The nutritional status of the patients has improved over the last 10 years, most significantly for wasting, which decreased from 58.3% in 1996 to 15.9% in 2006 (95% confidence interval (CI), 1.315-14.09, P < 0.05). Fifty-two percent of the children were underweight in 2006, compared with 66.7% in 1996 (95% CI, 0.044-13.96, P < 0.05). Stunting was found in 31.9% of the current sample. Females over 15 years had expected weight-for-age 25.9% lower than those between 10 years and 15 years, while no difference was found between the male age groups. Female height-for-age was 7.06 percentage points greater than males between 10 years and 15 years (95% CI, 2.16-11.96, P < 0.01). Males between 10 years and 15 years had significantly lower BMIs than the corresponding female group. Coloured patients had significantly lower BMIs than white patients in all age groups. These children demonstrated continuing improvement in nutritional status, although deficits remain. The normalisation of mean weight-for-age and weight-for-height with far fewer wasted patients is encouraging. Interventions are needed in some areas to ensure that all children show progress. © 2011 The Authors. Journal of Paediatrics and Child Health © 2011 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

De novo transcriptome of Ischnura elegans provides insights into sensory biology, colour and vision genes.

PubMed

Chauhan, Pallavi; Hansson, Bengt; Kraaijeveld, Ken; de Knijff, Peter; Svensson, Erik I; Wellenreuther, Maren

2014-09-22

There is growing interest in odonates (damselflies and dragonflies) as model organisms in ecology and evolutionary biology but the development of genomic resources has been slow. So far only one draft genome (Ladona fulva) and one transcriptome assembly (Enallagma hageni) have been published. Odonates have some of the most advanced visual systems among insects and several species are colour polymorphic, and genomic and transcriptomic data would allow studying the genomic architecture of these interesting traits and make detailed comparative studies between related species possible. Here, we present a comprehensive de novo transcriptome assembly for the blue-tailed damselfly Ischnura elegans (Odonata: Coenagrionidae) built from short-read RNA-seq data. The transcriptome analysis in this paper provides a first step towards identifying genes and pathways underlying the visual and colour systems in this insect group. Illumina RNA sequencing performed on tissues from the head, thorax and abdomen generated 428,744,100 paired-ends reads amounting to 110 Gb of sequence data, which was assembled de novo with Trinity. A transcriptome was produced after filtering and quality checking yielding a final set of 60,232 high quality transcripts for analysis. CEGMA software identified 247 out of 248 ultra-conserved core proteins as 'complete' in the transcriptome assembly, yielding a completeness of 99.6%. BLASTX and InterProScan annotated 55% of the assembled transcripts and showed that the three tissue types differed both qualitatively and quantitatively in I. elegans. Differential expression identified 8,625 transcripts to be differentially expressed in head, thorax and abdomen. Targeted analyses of vision and colour functional pathways identified the presence of four different opsin types and three pigmentation pathways. We also identified transcripts involved in temperature sensitivity, thermoregulation and olfaction. All these traits and their associated transcripts are of considerable ecological and evolutionary interest for this and other insect orders. Our work presents a comprehensive transcriptome resource for the ancient insect order Odonata and provides insight into their biology and physiology. The transcriptomic resource can provide a foundation for future investigations into this diverse group, including the evolution of colour, vision, olfaction and thermal adaptation.

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).

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.

Spectroscopic study of food and food toxins

NASA Astrophysics Data System (ADS)

King, Gavin; Walsh, James E.; Martin, Suzanne

2003-03-01

Fungal infection of food causes billions of dollars of lost revenue per annum as well as health problems, to animals and humans, if consumed in sufficient quantities. Modern food sorting techniques rely on colour or other physical characteristics to filter diseased or otherwise unsuitable foodstuffs from healthy foodstuffs. Their speeds are such that up to 40,000 objects per second can be moved at 4 metres per second, through 1 m wide chutes that offer a wide view for colour and shape sorting. Grain type foods such as coffee or peanuts are often vulnerable to toxic infection from invading fungi. If this happens, then their texture, taste and colour can change. Up to now, only visible wavelengths and colour identification have been used to bulk-sort food, but there has been little research in the ultra violet regions of the spectrum to help identify fungus or toxin infection. This research specifically concentrated on the ultra violet (UV) spectral characteristics of food in an attempt to identify possible spectral changes that occur when healthy food items like peanuts become infected with toxin-producing fungi. Ultimately, the goal is to design, build and construct an optical detection system that can use these 'spectral fingerprints' to more quickly and efficiently detect toxically infected food items.

Climate change is affecting mortality of weasels due to camouflage mismatch.

PubMed

Atmeh, Kamal; Andruszkiewicz, Anna; Zub, Karol

2018-05-24

Direct phenological mismatch caused by climate change can occur in mammals that moult seasonally. Two colour morphs of the weasel Mustela nivalis (M. n.) occur sympatrically in Białowieża Forest (NE Poland) and differ in their winter pelage colour: white in M. n. nivalis and brown in M. n. vulgaris. Due to their small body size, weasels are vulnerable to attacks by a range of different predators; thus cryptic coat colour may increase their winter survival. By analysing trapping data, we found that the share of white subspecies in the weasel population inhabiting Białowieża Forest decreases with decreasing numbers of days with snow cover. This led us to hypothesise that selective predation pressure should favour one of the two phenotypes, according to the prevailing weather conditions in winter. A simple field experiment with weasel models (white and brown), exposed against different background colours, revealed that contrasting models faced significantly higher detection by predators. Our observations also confirmed earlier findings that the plasticity of moult in M. n. nivalis is very limited. This means that climate change will strongly influence the mortality of the nivalis-type due to prolonged camouflage mismatch, which will directly affect the abundance and geographical distribution of this subspecies.

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.

Purple anthocyanin colouration on lower (abaxial) leaf surface of Hemigraphis colorata (Acanthaceae).

PubMed

Skaar, Irene; Adaku, Christopher; Jordheim, Monica; Byamukama, Robert; Kiremire, Bernard; Andersen, Øyvind M

2014-09-01

The functional significance of anthocyanin colouration of lower (abaxial) leaf surfaces is not clear. Two anthocyanins, 5-O-methylcyanidin 3-O-(3″-(β-glucuronopyranosyl)-β-glucopyranoside) (1) and 5-O-methylcyanidin 3-O-β-glucopyranoside (2), were isolated from Hemigraphis colorata (Blume) (Acanthaceae) leaves with strong purple abaxial colouration (2.2 and 0.6mg/gfr.wt., respectively). The glycosyl moiety of 1, the disaccharide 3″-(β-glucuronopyranosyl)-β-glucopyranoside), has previously been reported to occur only in a triterpenoid saponin, lindernioside A. The structural assignment of the aglycone of 1 and 2 is the first complete characterisation of a natural 7-hydroxy-5-methoxyanthocyanidin. Compared to nearly all naturally occurring anthocyanidins, the 5-O-methylation of this anthocyanidin limits the type of possible quinoidal forms of 1 and 2 to be those forms with keto-function in only their 7- and 4'-positions. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Comparison of performance of computer display monitors for radiological diagnosis; "diagnostic" high brightness monochrome LCD, 3MP vs "clinical review" colour LCD, 2MP.

PubMed

Sim, L; Manthey, K; Stuckey, S

2007-06-01

A study to compare performance of the following display monitors for application as PACS CR diagnostic workstations is described. 1. Diagnostic quality, 3 Mega Pixel, 21 inch monochrome LCD monitors--Planar C3i. 2. Clinical review quality, 2 Mega Pixel, 21 inch colour LCD monitors--Planar PX212. Two sets of seventy radiological studies were presented to four senior radiologists on two occasions, using different displays on each occasion. The clinical condition used for this investigation was to query for the presence of a solitary pulmonary nodule. Receiver Operating Characteristic (ROC) curves were constructed for diagnostic performance for each presentation. Areas under the ROC curves (AUC) for diagnosis using different monitors were compared and the following results obtained: Monochrome AUC = 0.813 +/- 0.02, Colour AUC = 0.801 +/- 0.021. These results indicate that there is no statistically significant difference in the performance of these monitor types at a 95% confidence level.

Heaven and Earth - `Madonne col Bambino' and `Rustiques figulines'

NASA Astrophysics Data System (ADS)

Bouquillon, A.

Analyses of the productions of della Robbia and Palissy, two masters of Renaissance ceramics in France and in Italy, have enlightened their contributions to the improvement of the glazed terracotta technique. Della Robbia used very homogeneous materials: marly clay for the bodies, and tin-opacified coloured glazes. The technique is here very robust and very mastered. Palissy used different types of clay with different colours and physical properties, associated with specific productions. So far, we have identified seven pastes. Concerning the glazes, he played with transparency and opacity, with lead glazes and with tin-opacified lead glazes. He added traditional colouring oxides as well as specific pigments (lead-tin yellow, haematite, etc.). The mixed-earth technique is specific to his palette. So, the materials used by both artists are completely different and illustrate their different philosophical approaches. To perform the different analyses, new methodologies have been developed: ICP/AES-MS, petrography and X-ray diffractometry for the bodies, PIXE and micro-PIXE, SEM coupled with EDS and Raman spectrometry for the glazes.

Impact of Site-Directed Mutant Luciferase on Quantitative Green and Orange/Red Emission Intensities in Firefly Bioluminescence

NASA Astrophysics Data System (ADS)

Wang, Yu; Akiyama, Hidefumi; Terakado, Kanako; Nakatsu, Toru

2013-08-01

Firefly bioluminescence has attracted great interest because of its high quantum yield and intriguing modifiable colours. Modifications to the structure of the enzyme luciferase can change the emission colour of firefly bioluminescence, and the mechanism of the colour change has been intensively studied by biochemists, structural biologists, optical physicists, and quantum-chemistry theorists. Here, we report on the quantitative spectra of firefly bioluminescence catalysed by wild-type and four site-directed mutant luciferases. While the mutation caused different emission spectra, the spectra differed only in the intensity of the green component (λmax ~ 560 nm). In contrast, the orange (λmax ~ 610 nm) and red (λmax ~ 650 nm) components present in all the spectra were almost unaffected by the modifications to the luciferases and changes in pH. Our results reveal that the intensity of the green component is the unique factor that is influenced by the luciferase structure and other reaction conditions.

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

Trial type mixing substantially reduces the response set effect in the Stroop task.

PubMed

Hasshim, Nabil; Parris, Benjamin A

2017-03-20

The response set effect refers to the finding that an irrelevant incongruent colour-word produces greater interference when it is one of the response options (referred to as a response set trial), compared to when it is not (a non-response set trial). Despite being a key effect for models of selective attention, the magnitude of the effect varies considerably across studies. We report two within-subjects experiments that tested the hypothesis that presentation format modulates the magnitude of the response set effect. Trial types (e.g. response set, non-response set, neutral) were either presented in separate blocks (pure) or in blocks containing trials from all conditions presented randomly (mixed). In the first experiment we show that the response set effect is substantially reduced in the mixed block context as a result of a decrease in RTs to response set trials. By demonstrating the modulation of the response set effect under conditions of trial type mixing we present evidence that is difficult for models of the effect based on strategic, top-down biasing of attention to explain. In a second experiment we tested a stimulus-driven account of the response set effect by manipulating the number of colour-words that make up the non-response set of distractors. The results show that the greater the number of non-response set colour concepts, the smaller the response set effect. Alternative accounts of the data and its implications for research debating the automaticity of reading are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Clinical and semiquantitative marginal analysis of four tooth-coloured inlay systems at 3 years.

PubMed

Gladys, S; Van Meerbeek, B; Inokoshi, S; Willems, G; Braem, M; Lambrechts, P; Vanherle, G

1995-12-01

The marginal quality of four tooth-coloured inlay systems was clinically investigated and subjected to computer-aided semiquantitative marginal analysis under scanning electron microscopy (SEM) after 3 years of clinical service. Three of the restoration types were made using the Cerec CAD-CAM apparatus: one was milled from preformed glass ceramic blocks, and the two other inlay types were milled from preformed porcelain blocks. The fourth system was based on an experimental indirect resin composite inlay system. Each inlay type was luted with a different luting resin composite. The clinical evaluation was performed with a mirror and explorer by two clinicians separately, and the marginal analysis was conducted microscopically on replicas (SEM x 200). After 3 years in situ, all the restorations were clinically acceptable. No recurrent caries was observed. Marginal analysis under SEM detected a high percentage of submargination for all four systems, which suggests that their respective resin composite luting agents were all subject to wear. The percentage of marginal fractures on the enamel side as well as on the inlay side did not increase dramatically compared to the 6-month results. The first recall after 6 months of clinical service indicated how tooth-coloured inlays behave at their margins. The 3-year results confirmed the early findings, indicating that wear of resin composite lutes is important and present in all systems. The two ceramic materials showed a similar behaviour at the margins. The resin composite inlay performed better at the inlay site than at the enamel site.

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.

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.

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

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

The effects of age, viewing distance, display type, font type, colour contrast and number of syllables on the legibility of Korean characters.

PubMed

Kong, Yong-Ku; Lee, Inseok; Jung, Myung-Chul; Song, Young-Woong

2011-05-01

This study evaluated the effects of age (20s and 60s), viewing distance (50 cm, 200 cm), display type (paper, monitor), font type (Gothic, Ming), colour contrast (black letters on white background, white letters on black background) and number of syllables (one, two) on the legibility of Korean characters by using the four legibility measures (minimum letter size for 100% correctness, maximum letter size for 0% correctness, minimum letter size for the least discomfort and maximum letter size for the most discomfort). Ten subjects in each age group read the four letters presented on a slide (letter size varied from 80 pt to 2 pt). Subjects also subjectively rated the reading discomfort of the letters on a 4-point scale (1 = no discomfort, 4 = most discomfort). According to the ANOVA procedure, age, viewing distance and font type significantly affected the four dependent variables (p < 0.05), while the main effect of colour contrast was not statistically significant for any measures. Two-syllable letters had smaller letters than one-syllable letters in the two correctness measures. The younger group could see letter sizes two times smaller than the old group could and the viewing distance of 50 cm showed letters about three times smaller than those at a 200 cm viewing distance. The Gothic fonts were smaller than the Ming fonts. Monitors were smaller than paper for correctness and maximum letter size for the most discomfort. From a comparison of the results for correctness and discomfort, people generally preferred larger letter sizes to those that they could read. The findings of this study may provide basic information for setting a global standard of letter size or font type to improve the legibility of characters written in Korean. STATEMENT OF RELEVANCE: Results obtained in this study will provide basic information and guidelines for setting standards of letter size and font type to improve the legibility of characters written in Korean. Also, the results might offer useful information for people who are working on design of visual displays.

Machine-learning identification of galaxies in the WISE × SuperCOSMOS all-sky catalogue

NASA Astrophysics Data System (ADS)

Krakowski, T.; Małek, K.; Bilicki, M.; Pollo, A.; Kurcz, A.; Krupa, M.

2016-11-01

Context. The two currently largest all-sky photometric datasets, WISE and SuperCOSMOS, have been recently cross-matched to construct a novel photometric redshift catalogue on 70% of the sky. Galaxies were separated from stars and quasars through colour cuts, which may leave imperfections because different source types may overlap in colour space. Aims: The aim of the present work is to identify galaxies in the WISE × SuperCOSMOS catalogue through an alternative approach of machine learning. This allows us to define more complex separations in the multi-colour space than is possible with simple colour cuts, and should provide a more reliable source classification. Methods: For the automatised classification we used the support vector machines (SVM) learning algorithm and employed SDSS spectroscopic sources that we cross-matched with WISE × SuperCOSMOS to construct the training and verification set. We performed a number of tests to examine the behaviour of the classifier (completeness, purity, and accuracy) as a function of source apparent magnitude and Galactic latitude. We then applied the classifier to the full-sky data and analysed the resulting catalogue of candidate galaxies. We also compared the resulting dataset with the one obtained through colour cuts. Results: The tests indicate very high accuracy, completeness, and purity (>95%) of the classifier at the bright end; this deteriorates for the faintest sources, but still retains acceptable levels of 85%. No significant variation in the classification quality with Galactic latitude is observed. When we applied the classifier to all-sky WISE × SuperCOSMOS data, we found 15 million galaxies after masking problematic areas. The resulting sample is purer than the one produced by applying colour cuts, at the price of a lower completeness across the sky. Conclusions: The automatic classification is a successful alternative approach to colour cuts for defining a reliable galaxy sample. The identifications we obtained are included in the public release of the WISE × SuperCOSMOS galaxy catalogue. The public release of the WISE × SuperCOSMOS galaxy catalogue is available from http://ssa.roe.ac.uk/WISExSCOS

Intrasexual competition facilitates the evolution of alternative mating strategies in a colour polymorphic fish.

PubMed

Hurtado-Gonzales, Jorge L; Uy, J Albert C

2010-12-23

Intense competition for access to females can lead to males exploiting different components of sexual selection, and result in the evolution of alternative mating strategies (AMSs). Males of Poecilia parae, a colour polymorphic fish, exhibit five distinct phenotypes: drab-coloured (immaculata), striped (parae), structural-coloured (blue) and carotenoid-based red and yellow morphs. Previous work indicates that immaculata males employ a sneaker strategy, whereas the red and yellow morphs exploit female preferences for carotenoid-based colours. Mating strategies favouring the maintenance of the other morphs remain to be determined. Here, we report the role of agonistic male-male interactions in influencing female mating preferences and male mating success, and in facilitating the evolution of AMSs. Our study reveals variation in aggressiveness among P. parae morphs during indirect and direct interactions with sexually receptive females. Two morphs, parae and yellow, use aggression to enhance their mating success (i.e., number of copulations) by 1) directly monopolizing access to females, and 2) modifying female preferences after winning agonistic encounters. Conversely, we found that the success of the drab-coloured immaculata morph, which specializes in a sneak copulation strategy, relies in its ability to circumvent both male aggression and female choice when facing all but yellow males. Strong directional selection is expected to deplete genetic variation, yet many species show striking genetically-based polymorphisms. Most studies evoke frequency dependent selection to explain the persistence of such variation. Consistent with a growing body of evidence, our findings suggest that a complex form of balancing selection may alternatively explain the evolution and maintenance of AMSs in a colour polymorphic fish. In particular, this study demonstrates that intrasexual competition results in phenotypically distinct males exhibiting clear differences in their levels of aggression to exclude potential sexual rivals. By being dominant, the more aggressive males are able to circumvent female mating preferences for attractive males, whereas another male type incorporates subordinate behaviours that allow them to circumvent male aggression and female mating preferences. Together, these and previous results indicate that exploiting different aspects of social interactions may allow males to evolve distinct mating strategies and thus the long term maintenance of polymorphisms within populations.

Near-infrared spectroscopic observations of massive young stellar object candidates in the central molecular zone

NASA Astrophysics Data System (ADS)

Nandakumar, G.; Schultheis, M.; Feldmeier-Krause, A.; Schödel, R.; Neumayer, N.; Matteucci, F.; Ryde, N.; Rojas-Arriagada, A.; Tej, A.

2018-01-01

Context. The central molecular zone (CMZ) is a 200 pc region around the Galactic centre. The study of star formation in the central part of the Milky Way is of great interest as it provides a template for the closest galactic nuclei. Aims: We present a spectroscopic follow-up of photometrically selected young stellar object (YSO) candidates in the CMZ of the Galactic centre. Our goal is to quantify the contamination of this YSO sample by reddened giant stars with circumstellar envelopes and to determine the star formation rate (SFR) in the CMZ. Methods: We obtained KMOS low-resolution near-infrared spectra (R 4000) between 2.0 and 2.5 μm of sources, many of which have been previously identified by mid-infrared photometric criteria as massive YSOs in the Galactic centre. Our final sample consists of 91 stars with good signal-to-noise ratio. We separated YSOs from cool late-type stars based on spectral features of CO and Brγ at 2.3 μm and 2.16 μm, respectively. We made use of spectral energy distribution (SED) model fits to the observed photometric data points from 1.25 to 24 μm to estimate approximate masses for the YSOs. Results: Using the spectroscopically identified YSOs in our sample, we confirm that existing colour-colour diagrams and colour-magnitude diagrams are unable to efficiently separate YSOs and cool late-type stars. In addition, we define a new colour-colour criterion that separates YSOs from cool late-type stars in the H-KS vs. H -[8.0] diagram. We use this new criterion to identify YSO candidates in the |l| < 1.̊5, |b| < 0.̊5, region and use model SED fits to estimate their approximate masses. By assuming an appropriate initial mass function (IMF) and extrapolating the stellar IMF down to lower masses, we determine a SFR of 0.046 ± 0.026 M⊙ yr-1 assuming an average age of 0.75 ± 0.25 Myr for the YSOs. This value is lower than estimates found using the YSO counting method in the literature. Conclusions: Our SFR estimate in the CMZ agrees with the previous estimates from various methods and reaffirms that star formation in the CMZ is proceeding at a lower rate than predicted by various star forming models. Based on observations collected at the European Southern Observatory, Chile, programme number 097.C-0208(A).

The iris signal: blue periphery, tan collaret and freckles pattern - strong indicators for epidermal skin cancer in South-Eastern Europe.

PubMed

Grigore, M; Furtunescu, F; Minca, D; Costache, M; Garbe, C; Simionescu, O

2018-03-10

Eye and skin share the embryological origin. Both are established risk factors in epidermal skin cancer. There are few reports using iris colour classification scales, most of them analyse colour in general or are too complex to use in daily practice. To investigate which iris colour pattern is associated with epidermal skin cancer in a S-E European Caucasian population. A case-control study was conducted on 480 patients: 229 skin cancers patients and 251 controls (dermatological patients free of skin cancers) admitted in two medical clinics of Dermatology in Bucharest, between October 2011 and May 2014. High-resolution iris photographs were taken for each patient. Three parameters of the iris were analysed individually and in association patterns for each patient: periphery, collaret and freckles. The most frequent iris colour pattern associated with epidermal skin cancer was blue periphery with light brown collaret and freckles present. In terms of individual parameters, the strongest indicators for skin cancer patients were blue periphery and blue collaret. The results of this study sustain the hypothesis that blue periphery with light brown collaret and freckles iris pattern is a reliable phenotypic marker for epidermal skin cancer. The results of this study differ from previous reports in which skin cancer risk was associated with a homogeneous blue iris. We account these differences in the characteristics of the recruited patients (S-E European, skin type II and III). The assessment of iris colour patterns is an easy and inexpensive detection tool in skin cancer risk assessment. © 2018 European Academy of Dermatology and Venereology.

Effects of emotional and non-emotional cues on visual search in neglect patients: evidence for distinct sources of attentional guidance.

PubMed

Lucas, Nadia; Vuilleumier, Patrik

2008-04-01

In normal observers, visual search is facilitated for targets with salient attributes. We compared how two different types of cue (expression and colour) may influence search for face targets, in healthy subjects (n=27) and right brain-damaged patients with left spatial neglect (n=13). The target faces were defined by their identity (singleton among a crowd of neutral faces) but could either be neutral (like other faces), or have a different emotional expression (fearful or happy), or a different colour (red-tinted). Healthy subjects were the fastest for detecting the colour-cued targets, but also showed a significant facilitation for emotionally cued targets, relative to neutral faces differing from other distracter faces by identity only. Healthy subjects were also faster overall for target faces located on the left, as compared to the right side of the display. In contrast, neglect patients were slower to detect targets on the left (contralesional) relative to the right (ipsilesional) side. However, they showed the same pattern of cueing effects as healthy subjects on both sides of space; while their best performance was also found for faces cued by colour, they showed a significant advantage for faces cued by expression, relative to the neutral condition. These results indicate that despite impaired attention towards the left hemispace, neglect patients may still show an intact influence of both low-level colour cues and emotional expression cues on attention, suggesting that neural mechanisms responsible for these effects are partly separate from fronto-parietal brain systems controlling spatial attention during search.

Rigorous Characterisation of a Novel, Statistically-Based Ocean Colour Algorithm for the PACE Mission

NASA Astrophysics Data System (ADS)

Craig, S. E.; Lee, Z.; Du, K.; Lin, J.

2016-02-01

An approach based on empirical orthogonal function (EOF) analysis of ocean colour spectra has been shown to accurately derive inherent optical properties (IOPs) and chlorophyll concentration in scenarios, such as optically complex waters, where standard algorithms often perform poorly. The algorithm has been successfully used in a number of regional applications, and has also shown promise in a global implementation based on the NASA NOMAD data set. Additionally, it has demonstrated the unique ability to derive ocean colour products from top of atmosphere (TOA) signals with either no or minimal atmospheric correction applied. Due to its high potential for use over coastal and inland waters, the EOF approach is currently being rigorously characterised as part of a suite of approaches that will be used to support the new NASA ocean colour mission, PACE (Pre-Aerosol, Clouds and ocean Ecosystem). A major component in this model characterisation is the generation of a synthetic TOA data set using a coupled ocean-atmosphere radiative transfer model, which has been run to mimic PACE spectral resolution, and under a wide range of geographical locations, water constituent concentrations, and sea surface and atmospheric conditions. The resulting multidimensional data set will be analysed, and results presented on the sensitivity of the model to various combinations of parameters, and preliminary conclusions made regarding the optimal implementation strategy of this promising approach (e.g. on a global, optical water type or regional basis). This will provide vital guidance for operational implementation of the model for both existing satellite ocean colour sensors and the upcoming PACE mission.

Dark Adaptation of Colour Vision in Diabetic Subjects

NASA Astrophysics Data System (ADS)

Márquez-Gamiño, S.; Cortés-Peñaloza, J. L.; Pérez-Hernández, J. U.; Cruz-Rodríguez, E.; Caudillo, C.

2004-09-01

Eye disease, a late complication of diabetes mellitus (DM) occurs even under a careful glicemic control. It includes optic nerve, retina, vitreous humor, crystalline lens and pupillary affection. The physiopathological process could be independent of blood glucose levels or start at initial stages of the disease. Photoreceptors have specific physiological functions. The functional substrate of day light or colour vision in superior primates, the cones have different spectral sensitivity, 455, 530 and 560 nm. The rods, maximal sensitivity at 505 nm, are much more sensitive to light than are cones. Dark adaptation was tested to evaluate functional impairment differences in photoreceptors of diabetic subjects. 14 DM2 (type 2 DM), and 5 DM1 (type 1 DM) patients, as well as 9 healthy subjects were studied. Retinal affected individuals, were excluded. Dark adaptation curves seemed to be different between DM, and healthy subjects. Cones, specially those sensitive to 560 nm type, seems to be more labile to DM, as demonstrated by the lack of sensitivity to low, and medium intensity stimuli. Medical Physics and elementary Biomedical Engineering exhibited to be useful to discern malfunction between different types of photorreceptors. The inexpensive method used could be applied for early color vision alteration detection.

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.

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.

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.

Height-diameter equations for young-growth red fir in California and southern Oregon

Treesearch

K. Leroy Dolph

1989-01-01

Total tree height of young-growth red fir can be estimated from the relation of total tree height to diameter outside bark at breast height (DOB). Total tree heights and corresponding diameters were obtained from stem analyses of 562 trees distributed across 56 sampling locations in the true fir forest type of California and Oregon. The resulting equations can predict...

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

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.

Nutritional and socioeconomic status in cognitive development of Santal children of Purulia district, India.

PubMed

Chowdhury, Sutanu Dutta; Ghosh, Tusharkanti

2011-03-01

Cognitive development of children depends on nutritional and socioeconomic factors. The objectives of the present study were to assess the cognitive development and to investigate the relationship of nutritional and socioeconomic status (SES) to cognitive development in 5-12 year old Santal children of Purulia district of West Bengal, India. The nutritional status of each child was assessed by z-score of height-for-age, weight-for-height and weight-for-age parameters. SES was measured using the updated Kuppusswami scale. Cognitive development was measured by Raven's Coloured Progressive Matrices (RCPM). The growth curve of RCPM scores of Santal children remained around the 5(th) percentile values of British children. The RCPM scores of the adequately nourished children and upper-lower SES were significantly higher (p < 0.05) than the children with lower SES and nutritional status. About 42.96% and 27.69% of Santal children were found to be in the intellectually deficient and below average groups, respectively. RCPM scores of Santal children were significantly correlated with nutritional status and socioeconomic factors (p < 0.01). The surveyed children showed poor cognitive functions. The vulnerable nutritional and socioeconomic statuses of Santal children are the major causes for their poor cognitive development.

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.

Investigating Neuromagnetic Brain Responses against Chromatic Flickering Stimuli by Wavelet Entropies

PubMed Central

Bhagat, Mayank; Bhushan, Chitresh; Saha, Goutam; Shimjo, Shinsuke; Watanabe, Katsumi; Bhattacharya, Joydeep

2009-01-01

Background Photosensitive epilepsy is a type of reflexive epilepsy triggered by various visual stimuli including colourful ones. Despite the ubiquitous presence of colorful displays, brain responses against different colour combinations are not properly studied. Methodology/Principal Findings Here, we studied the photosensitivity of the human brain against three types of chromatic flickering stimuli by recording neuromagnetic brain responses (magnetoencephalogram, MEG) from nine adult controls, an unmedicated patient, a medicated patient, and two controls age-matched with patients. Dynamical complexities of MEG signals were investigated by a family of wavelet entropies. Wavelet entropy is a newly proposed measure to characterize large scale brain responses, which quantifies the degree of order/disorder associated with a multi-frequency signal response. In particular, we found that as compared to the unmedicated patient, controls showed significantly larger wavelet entropy values. We also found that Renyi entropy is the most powerful feature for the participant classification. Finally, we also demonstrated the effect of combinational chromatic sensitivity on the underlying order/disorder in MEG signals. Conclusions/Significance Our results suggest that when perturbed by potentially epileptic-triggering stimulus, healthy human brain manages to maintain a non-deterministic, possibly nonlinear state, with high degree of disorder, but an epileptic brain represents a highly ordered state which making it prone to hyper-excitation. Further, certain colour combination was found to be more threatening than other combinations. PMID:19779630

Investigating neuromagnetic brain responses against chromatic flickering stimuli by wavelet entropies.

PubMed

Bhagat, Mayank; Bhushan, Chitresh; Saha, Goutam; Shimjo, Shinsuke; Watanabe, Katsumi; Bhattacharya, Joydeep

2009-09-25

Photosensitive epilepsy is a type of reflexive epilepsy triggered by various visual stimuli including colourful ones. Despite the ubiquitous presence of colorful displays, brain responses against different colour combinations are not properly studied. Here, we studied the photosensitivity of the human brain against three types of chromatic flickering stimuli by recording neuromagnetic brain responses (magnetoencephalogram, MEG) from nine adult controls, an unmedicated patient, a medicated patient, and two controls age-matched with patients. Dynamical complexities of MEG signals were investigated by a family of wavelet entropies. Wavelet entropy is a newly proposed measure to characterize large scale brain responses, which quantifies the degree of order/disorder associated with a multi-frequency signal response. In particular, we found that as compared to the unmedicated patient, controls showed significantly larger wavelet entropy values. We also found that Renyi entropy is the most powerful feature for the participant classification. Finally, we also demonstrated the effect of combinational chromatic sensitivity on the underlying order/disorder in MEG signals. Our results suggest that when perturbed by potentially epileptic-triggering stimulus, healthy human brain manages to maintain a non-deterministic, possibly nonlinear state, with high degree of disorder, but an epileptic brain represents a highly ordered state which making it prone to hyper-excitation. Further, certain colour combination was found to be more threatening than other combinations.

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.

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.

Implementation of spaceborne lidar-retrieved canopy height in the WRF model

NASA Astrophysics Data System (ADS)

Lee, Junhong; Hong, Jinkyu

2016-06-01

Canopy height is closely related to biomass and aerodynamic properties, which regulate turbulent transfer of energy and mass at the soil-vegetation-atmosphere continuum. However, this key information has been prescribed as a constant value in a fixed plant functional type in atmospheric models. This paper is the first to report impacts of using realistic forest canopy height, retrieved from spaceborne lidar, on regional climate simulation by using the canopy height data in the Weather Research and Forecasting (WRF) model's land surface model. Numerical simulations were conducted over the Amazon Basin during summer season. Over this region, the lidar-retrieved canopy heights were higher than the default values used in the WRF, which are dependent only on plant functional type. By modifying roughness length and zero-plane displacement height, the change of canopy height resulted in changes in surface energy balance by regulating aerodynamic conductances and vertical temperature gradient, thus modifying the lifting condensation level and equivalent potential temperature in the atmospheric boundary layer. Our analysis also showed that the WRF model better reproduced the observed precipitation when lidar-retrieved canopy height was used over the Amazon Basin.

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.

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.

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.

Influence of Soil Type and Drainage on Growth of Swamp Chestnut Oak (Quercus Michauxii Nutt.) Seedlings

Treesearch

Donald D. Hook

1969-01-01

Swamp chestnut oak (Quercus michauxii Nutt.) seedlings were grown for 2 years in five soil types in drained and undrained pots. First-year height growth was related to soil type and pot drainage, but second-year height growth was related only to soil type. Results suggest that swamp chestnut oak is site-sensitive. But slow growth, a maximum of 2...

Protection against impact with the ground using wearable airbags.

PubMed

Fukaya, Kiyoshi; Uchida, Mitsuya

2008-01-01

Incidental falls from heights, falls on the same level caused by slipping or tripping, and falls from wheelchair overturns are commonplace phenomena, associated with serious injuries from impact with the ground. A wearable airbag device is a countermeasure applicable to all these types of incidents. Three types of wearable airbag systems were developed and evaluated: for protection against falls from heights (Type-1), against wheelchair overturns (Type-2), and against falls on the same level (Type-3). The systems consist of an airbag, sensor, inflator, and jacket. The sensor detects the fall and the airbag inflates to protect the user. Fall tests using dummies with/without the airbags demonstrated the effectiveness of these devices. In the experiments with system Type-1, for fall heights of less than 2m, the airbags reduced the impact acceleration, and the Head Injury Criterion (HIC) values were under 1,000, the auto-crash test requirement. However, there are limits to the amount of protection afforded: in Type-1, the airbag can protect only the back of the head.; in Types-2 and 3, the fall height of the center of gravity is lower than 2m, and there is some margin of extra protective resource, which can be used to extend the protected area.

Characterization of Staphylococcus aureus isolates from faecal samples of the Straw-Coloured Fruit Bat (Eidolon helvum) in Obafemi Awolowo University (OAU), Nigeria.

PubMed

Akobi, Babatunji; Aboderin, Oladipo; Sasaki, Takashi; Shittu, Adebayo

2012-11-26

Bats (Chiroptera) are one of the most diverse groups of mammals which carry out important ecological and agricultural functions that are beneficial to humans. However, they are increasingly recognized as natural vectors for a number of zoonotic pathogens and favourable hosts for zoonotic infections. Large populations of the Straw-Coloured Fruit Bat (Eidolon helvum) colonize the main campus of the Obafemi Awolowo University (OAU), Ile-Ife, Nigeria, but the public health implications of faecal contamination and pollution by these flying mammals is unknown. This study characterized S. aureus obtained from faecal samples of these migratory mammals with a view to determining the clonal types of the isolates, and to investigate the possibility of these flying animals as potential reservoir for zoonotic S. aureus infections. One hundred and seven (107) S. aureus isolates were recovered from 560 faecal samples in eleven roosting sites from January 2008 to February 2010. A large proportion of the isolates were susceptible to antibiotics, and molecular characterization of 70 isolates showed that 65 (92.9%) were assigned in coagulase type VI, while accessory gene typing classified 69 isolates into the following: type I (12; 17.1%), type II (3; 4.3%), type III (1; 1.4%) and type IV (53; 75.7%). On the whole, the isolates were grouped in five (A-E) main genotypes. Of the ten representative isolates selected for multilocus sequence typing (MLST), nine isolates were assigned with new sequence types: ST1725, ST1726, ST1727, ST2463-ST2467 and ST2470. Phylogenetic analysis provided evidence that S. aureus isolates in group C were closely related with ST1822 and associated clones identified in African monkeys, and group D isolates with ST75, ST883 and ST1223. The two groups exhibited remarkable genetic diversity compared to the major S. aureus clade. Antibiotic resistance in faecal S. aureus isolates of E. helvum is low and multiple unique S. aureus lineages co-existed with E. helvum. The Straw-Coloured Fruit Bat in Ile-Ife, Nigeria is colonized predominantly by ST1725, ST1726, ST2463 and ST2470 with distinct genotypic characteristics that are rarely found in humans. This study has demonstrated on the possible existence of a reservoir of indigenous and anciently-divergent S. aureus clones among mammals in Africa.

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.

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

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.

Three-dimensional endoanal ultrasound is accurate and reproducible in determining type and height of anal fistulas.

PubMed

Kołodziejczak, M; Santoro, G A; Obcowska, A; Lorenc, Z; Mańczak, M; Sudoł-Szopińska, I

2017-04-01

Surgical treatment of high anal fistulas is associated with the potential risk of faecal incontinence and recurrence. The primary aim of this study was to determine the accuracy of three-dimensional endoanal ultrasound (3D-EAUS) in the assessment of height and type of anal fistulas, compared to the intra-operative findings (gold standard). The secondary aim was to evaluate the inter-observer reproducibility of 3D-EAUS. The study design was a prospective analysis of retrospective data. 299 patients (202 men), mean age 45.3 years, who underwent surgery for anal fistulas, were included. All patients were preoperatively assessed by 3D-EAUS. Two readers independently reviewed the volumes to determine the type and height of fistulas. Sensitivity, specificity, positive and negative predictive values, proportion of agreements and Cohen's kappa coefficient (κ) were calculated for both examiners. Ultrasound findings were compared with intra-operative data (reference standard), evaluated blindly by the surgeons. At surgery, 201 (67%) were transsphincteric, 49 (16%) suprasphincteric, 47 (16%) intersphincteric and two (1%) extrasphincteric fistulas. Intra-operatively, 177 (59%) were low and 122 (41%) high fistulas. The overall accuracy of 3D-EAUS was 91% for fistula type (271/299 fistulas: 97% transsphincteric, 100% intersphincteric, 57% suprasphincteric, 0% extrasphincteric) and 92% for fistula height (275/299 fistulas: 80% high and 100% low). Both readers reported very good agreement with surgery in the assessment of fistula type (proportion of agreement 0.88, κ = 0.89) and height (proportion of agreement 0.90, κ = 0.91). 3D-EAUS is an accurate and reproducible modality for the assessment of type and height of anal fistulas. Colorectal Disease © 2016 The Association of Coloproctology of Great Britain and Ireland.

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.

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 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.

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.

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.

Follicular contact dermatitis due to coloured permanent-pressed sheets

PubMed Central

Panaccio, François; Montgomery, D. C.; Adam, J. E.

1973-01-01

A delayed hypersensitivity type of allergic contact dermatitis was observed following exposure to certain brands of 50% cotton, 50% polyester coloured permanent-pressed sheets produced by a particular manufacturer. The dermatitis presented as an extremely pruritic follicular eczema of the body and vesicular edema of the ears and face. Patch testing excluded formalin as the allergen but suggested permanent-pressing chemicals as a possibility. Several washings of the sheets did not prevent the development of the dermatitis. The removal of sheets did not immediately result in improvement: the condition could persist for up to eight weeks after their discontinuance. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5 PMID:4268628

VizieR Online Data Catalog: 3D correction in 5 photometric systems (Bonifacio+, 2018)

NASA Astrophysics Data System (ADS)

Bonifacio, P.; Caffau, E.; Ludwig, H.-G.; Steffen, M.; Castelli, F.; Gallagher, A. J.; Kucinskas, A.; Prakapavicius, D.; Cayrel, R.; Freytag, B.; Plez, B.; Homeier, D.

2018-01-01

We have used the CIFIST grid of CO5BOLD models to investigate the effects of granulation on fluxes and colours of stars of spectral type F, G, and K. We publish tables with 3D corrections that can be applied to colours computed from any 1D model atmosphere. For Teff>=5000K, the corrections are smooth enough, as a function of atmospheric parameters, that it is possible to interpolate the corrections between grid points; thus the coarseness of the CIFIST grid should not be a major limitation. However at the cool end there are still far too few models to allow a reliable interpolation. (20 data files).

A new species of cat snake (Reptilia: Serpentes: Colubridae: Boiga) from dry forests of eastern Peninsular India.

PubMed

Vogel, Gernot; Ganesh, S R

2013-01-01

A new species of cat snake, related to Boiga beddomei (Wall, 1909), is described from the dry forests of eastern Peninsular India. It occupies a large geographic range from Berhampore (type locality), near the River Mahanadi in the northeast to Kaigal near the southern Eastern Ghats in the southwest. The new species is diagnosed by having the following combination of characters: 19 dorsal scale rows at midbody, a high number of ventral scales for the genus Boiga (248-259), a yellowish-green dorsal colouration with numerous faint black bands, an uniform, unpatterned yellow-coloured venter and a relatively short tail (0.180-0.200 of the total length).

Charming dark matter

NASA Astrophysics Data System (ADS)

Jubb, Thomas; Kirk, Matthew; Lenz, Alexander

2017-12-01

We have considered a model of Dark Minimal Flavour Violation (DMFV), in which a triplet of dark matter particles couple to right-handed up-type quarks via a heavy colour-charged scalar mediator. By studying a large spectrum of possible constraints, and assessing the entire parameter space using a Markov Chain Monte Carlo (MCMC), we can place strong restrictions on the allowed parameter space for dark matter models of this type.

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.

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.

An experience of electron beam (EB) irradiated gemstones in Malaysian nuclear agency

NASA Astrophysics Data System (ADS)

Idris, Sarada; Hairaldin, Siti Zulaiha; Tajau, Rida; Karim, Jamilah; Jusoh, Suhaimi; Ghazali, Zulkafli; Ahmad, Shamshad

2014-02-01

In Nuclear Malaysia, a study on gemstone irradiation using beta particle is conducted. The purpose of the study is to evaluate the gemstone colour enhancement by using different kind of precious and non-precious gemstones. By using irradiation technique, selected gemstones are exposed to highly ionizing radiation electron beam to knock off electrons to generate colour centres culminating in the introduction of deeper colours. The colour centres may be stable or unstable depending on the nature of colour centre produced. The colour change of irradiated stones were measured by HunterLab colour measurement. At 50 kGy, Topaz shows changes colour from colourless to golden. Meanwhile pearl shows changes from pale colour to grey. Kunzite and amethyst shows colour changes from colorless to green and pale colour to purple. Gamma survey meter measurement confirmed that irradiation treatment with 3 MeV electron beam machine does not render any activation that activate the gems to become radioactive.

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.

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.

An experience of electron beam (EB) irradiated gemstones in Malaysian nuclear agency

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

Idris, Sarada, E-mail: sarada@nuclearmalaysia.gov.my; Hairaldin, Siti Zulaiha, E-mail: sarada@nuclearmalaysia.gov.my; Tajau, Rida, E-mail: sarada@nuclearmalaysia.gov.my

In Nuclear Malaysia, a study on gemstone irradiation using beta particle is conducted. The purpose of the study is to evaluate the gemstone colour enhancement by using different kind of precious and non-precious gemstones. By using irradiation technique, selected gemstones are exposed to highly ionizing radiation electron beam to knock off electrons to generate colour centres culminating in the introduction of deeper colours. The colour centres may be stable or unstable depending on the nature of colour centre produced. The colour change of irradiated stones were measured by HunterLab colour measurement. At 50 kGy, Topaz shows changes colour from colourlessmore » to golden. Meanwhile pearl shows changes from pale colour to grey. Kunzite and amethyst shows colour changes from colorless to green and pale colour to purple. Gamma survey meter measurement confirmed that irradiation treatment with 3 MeV electron beam machine does not render any activation that activate the gems to become radioactive.« less

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.

Virtual forensic anthropology: Novel applications of anthropometry and technology in a child death case.

PubMed

Davy-Jow, Stephanie Lynn; Lees, Duncan M B; Russell, Sean

2013-01-10

Full-body 3D virtual reconstructions were generated using 3D technology and anthropometry following the death of a young girl, allegedly from severe malnutrition as a result of abuse and neglect. Close range laser scanning, in conjunction with full colour digital texture photography, was used to document the child's condition shortly after death in order to demonstrate the number and pattern of injuries and to be able to demonstrate her condition forensically. Full-body digital reconstructions were undertaken to illustrate the extent of the malnutrition by comparing the processed post mortem scans with reconstructed images at normal weight for height and age. This is the first known instance of such an investigative tool. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Daily and seasonal changes in heat exposure and the Hsp70 level of individuals from a field population of Xeropicta derbentina (Krynicki 1836) (Pulmonata, Hygromiidae) in Southern France.

PubMed

Dieterich, A; Fischbach, U; Ludwig, M; Di Lellis, M A; Troschinski, S; Gärtner, U; Triebskorn, R; Köhler, H-R

2013-07-01

The Mediterranean land snail Xeropicta derbentina forms huge populations in Southern France. In order to characterize heat exposure and the induction of the 70-kD heat shock protein (Hsp70) response system during the life cycle of this snail, a selected population from the Vaucluse area, Provence, was investigated encompassing the issues of morphological life cycle parameters (shell size and colouration), the daily courses of heat exposure at different heights above the ground, of shell temperature, and that of the individual Hsp70 levels. The study covered all four seasons of the year 2011. Snails were found to be annual, reaching their final size in August. The shell colouration pattern showed high variation in juveniles (spring) with a strong tendency towards becoming uniformly white at old age in autumn. In all seasons, ambient air temperature decreased with increasing distance from the ground surface during daytime while remaining constantly low in the night. Overall, the Hsp70 level of individuals followed the ambient temperature during diurnal and seasonal variations. Correlation analysis revealed a positive association of individual shell temperature and Hsp70 level for the most part of the life cycle of the snails until late summer, whereas a negative correlation was found for aged animals indicating senescence effects on the capacity of the stress response system.

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.

Shock Formation Height in the Solar Corona Estimated from SDO and Radio Observations

NASA Technical Reports Server (NTRS)

Gopalswamy, N.; Nitta, N.

2011-01-01

Wave transients at EUV wavelengths and type II radio bursts are good indicators of shock formation in the solar corona. We use recent EUV wave observations from SDO and combine them with metric type II radio data to estimate the height in the corona where the shocks form. We compare the results with those obtained from other methods. We also estimate the shock formation heights independently using white-light observations of coronal mass ejections that ultimately drive the shocks.

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

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

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.

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.

Spatial structure of cone inputs to receptive fields in primate lateral geniculate nucleus

NASA Astrophysics Data System (ADS)

Reid, R. Clay; Shapley, Robert M.

1992-04-01

HUMAN colour vision depends on three classes of cone photoreceptors, those sensitive to short (S), medium (M) or long (L) wavelengths, and on how signals from these cones are combined by neurons in the retina and brain. Macaque monkey colour vision is similar to human, and the receptive fields of macaque visual neurons have been used as an animal model of human colour processing1. P retinal ganglion cells and parvocellular neurons are colour-selective neurons in macaque retina and lateral geniculate nucleus. Interactions between cone signals feeding into these neurons are still unclear. On the basis of experimental results with chromatic adaptation, excitatory and inhibitory inputs from L and M cones onto P cells (and parvocellular neurons) were thought to be quite specific2,3 (Fig. la). But these experiments with spatially diffuse adaptation did not rule out the 'mixed-surround' hypothesis: that there might be one cone-specific mechanism, the receptive field centre, and a surround mechanism connected to all cone types indiscriminately (Fig. le). Recent work has tended to support the mixed-surround hypothesis4-8. We report here the development of new stimuli to measure spatial maps of the linear L-, M- and S-cone inputs to test the hypothesis definitively. Our measurements contradict the mixed-surround hypothesis and imply cone specificity in both centre and surround.

Multimodal signalling in estrildid finches: song, dance and colour are associated with different ecological and life-history traits.

PubMed

Gomes, A C R; Funghi, C; Soma, M; Sorenson, M D; Cardoso, G C

2017-07-01

Sexual traits (e.g. visual ornaments, acoustic signals, courtship behaviour) are often displayed together as multimodal signals. Some hypotheses predict joint evolution of different sexual signals (e.g. to increase the efficiency of communication) or that different signals trade off with each other (e.g. due to limited resources). Alternatively, multiple signals may evolve independently for different functions, or to communicate different information (multiple message hypothesis). We evaluated these hypotheses with a comparative study in the family Estrildidae, one of the largest songbird radiations, and one that includes many model species for research in sexual selection and communication. We found little evidence for either joint evolution or trade-offs between song and colour ornamentation. Some negative correlations between dance repertoire and song traits may suggest a functional compromise, but generally courtship dance also evolved independently from other signals. Instead of correlated evolution, we found that song, dance and colour are each related to different socio-ecological traits. Song complexity evolved together with ecological generalism, song performance with investment in reproduction, dance with commonness and habitat type, whereas colour ornamentation was shown previously to correlate mostly with gregariousness. We conclude that multimodal signals evolve in response to various socio-ecological traits, suggesting the accumulation of distinct signalling functions. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Skin image retrieval using Gabor wavelet texture feature.

PubMed

Ou, X; Pan, W; Zhang, X; Xiao, P

2016-12-01

Skin imaging plays a key role in many clinical studies. We have used many skin imaging techniques, including the recently developed capacitive contact skin imaging based on fingerprint sensors. The aim of this study was to develop an effective skin image retrieval technique using Gabor wavelet transform, which can be used on different types of skin images, but with a special focus on skin capacitive contact images. Content-based image retrieval (CBIR) is a useful technology to retrieve stored images from database by supplying query images. In a typical CBIR, images are retrieved based on colour, shape, texture, etc. In this study, texture feature is used for retrieving skin images, and Gabor wavelet transform is used for texture feature description and extraction. The results show that the Gabor wavelet texture features can work efficiently on different types of skin images. Although Gabor wavelet transform is slower compared with other image retrieval techniques, such as principal component analysis (PCA) and grey-level co-occurrence matrix (GLCM), Gabor wavelet transform is the best for retrieving skin capacitive contact images and facial images with different orientations. Gabor wavelet transform can also work well on facial images with different expressions and skin cancer/disease images. We have developed an effective skin image retrieval method based on Gabor wavelet transform, that it is useful for retrieving different types of images, namely digital colour face images, digital colour skin cancer and skin disease images, and particularly greyscale skin capacitive contact images. Gabor wavelet transform can also be potentially useful for face recognition (with different orientation and expressions) and skin cancer/disease diagnosis. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Comparative structure and pollen production of the stamens and pollinator-deceptive staminodes of Commelina coelestis and C. dianthifolia (Commelinaceae).

PubMed

Hrycan, William C; Davis, Arthur R

2005-06-01

Flowers of Commelina coelestis and C. dianthifolia provide pollen alone as a floral reward, and rely on visual cues to attract pollinators. Three stamen types, all producing pollen, occur in each of these species: two cryptically coloured lateral stamens, a single cryptically coloured central stamen and three bright yellow staminodes that sharply contrast with the blue to purple corolla. The objective was to compare the stamen structure and pollen characteristics of each of the three stamen types, and to test the hypothesis that the staminodes are poor contributors of viable pollen for the siring of seed. The pollination roles of the three stamen types and the breeding systems of both species were also explored. Light, fluorescence and scanning electron microscopy were utilized to examine stamen morphology and pollen structure and viability. Controlled hand pollinations were used to explore the breeding system of each species. Filament and style lengths were measured to investigate herkogamy and autogamy. Pollen from all stamen morphs is viable, but staminode pollen has significantly lower viability. Pollen polymorphism exists both (a) between the lateral and central stamens and the staminodes, and (b) within each anther. Lateral and central stamens have thicker endothecia with a greater number of secondary cell wall thickenings than the staminodes. Both species are entomophilous and facultatively autogamous. Lateral stamen pollen is important for cross-pollination, central stamen pollen is utilized by both species as a pollinator reward and for delayed autogamy in C. dianthifolia, and the staminodes mimic, by means of both colour and epidermal features, large amounts of pollen to attract insects to the flowers. Pollen from all three anther morphs is capable of siring seed, although staminode pollen is inferior. The thin staminode endothecium with fewer secondary thickenings retards staminode dehiscence.

No psychological effect of color context in a low level vision task

PubMed Central

Pedley, Adam; Wade, Alex R

2013-01-01

Background: A remarkable series of recent papers have shown that colour can influence performance in cognitive tasks. In particular, they suggest that viewing a participant number printed in red ink or other red ancillary stimulus elements improves performance in tasks requiring local processing and impedes performance in tasks requiring global processing whilst the reverse is true for the colour blue. The tasks in these experiments require high level cognitive processing such as analogy solving or remote association tests and the chromatic effect on local vs. global processing is presumed to involve widespread activation of the autonomic nervous system. If this is the case, we might expect to see similar effects on all local vs. global task comparisons. To test this hypothesis, we asked whether chromatic cues also influence performance in tasks involving low level visual feature integration. Methods: Subjects performed either local (contrast detection) or global (form detection) tasks on achromatic dynamic Glass pattern stimuli. Coloured instructions, target frames and fixation points were used to attempt to bias performance to different task types. Based on previous literature, we hypothesised that red cues would improve performance in the (local) contrast detection task but would impede performance in the (global) form detection task.  Results: A two-way, repeated measures, analysis of covariance (2×2 ANCOVA) with gender as a covariate, revealed no influence of colour on either task, F(1,29) = 0.289, p = 0.595, partial η 2 = 0.002. Additional analysis revealed no significant differences in only the first attempts of the tasks or in the improvement in performance between trials. Discussion: We conclude that motivational processes elicited by colour perception do not influence neuronal signal processing in the early visual system, in stark contrast to their putative effects on processing in higher areas. PMID:25075280

No psychological effect of color context in a low level vision task.

PubMed

Pedley, Adam; Wade, Alex R

2013-01-01

A remarkable series of recent papers have shown that colour can influence performance in cognitive tasks. In particular, they suggest that viewing a participant number printed in red ink or other red ancillary stimulus elements improves performance in tasks requiring local processing and impedes performance in tasks requiring global processing whilst the reverse is true for the colour blue. The tasks in these experiments require high level cognitive processing such as analogy solving or remote association tests and the chromatic effect on local vs. global processing is presumed to involve widespread activation of the autonomic nervous system. If this is the case, we might expect to see similar effects on all local vs. global task comparisons. To test this hypothesis, we asked whether chromatic cues also influence performance in tasks involving low level visual feature integration. Subjects performed either local (contrast detection) or global (form detection) tasks on achromatic dynamic Glass pattern stimuli. Coloured instructions, target frames and fixation points were used to attempt to bias performance to different task types. Based on previous literature, we hypothesised that red cues would improve performance in the (local) contrast detection task but would impede performance in the (global) form detection task.  A two-way, repeated measures, analysis of covariance (2×2 ANCOVA) with gender as a covariate, revealed no influence of colour on either task, F(1,29) = 0.289, p = 0.595, partial η (2) = 0.002. Additional analysis revealed no significant differences in only the first attempts of the tasks or in the improvement in performance between trials. We conclude that motivational processes elicited by colour perception do not influence neuronal signal processing in the early visual system, in stark contrast to their putative effects on processing in higher areas.

Spots and stripes: ecology and colour pattern evolution in butterflyfishes

PubMed Central

Kelley, Jennifer L.; Fitzpatrick, John L.; Merilaita, Sami

2013-01-01

The incredible diversity of colour patterns in coral reef fishes has intrigued biologists for centuries. Yet, despite the many proposed explanations for this diversity in coloration, definitive tests of the role of ecological factors in shaping the evolution of particular colour pattern traits are absent. Patterns such as spots and eyespots (spots surrounded by concentric rings of contrasting colour) have often been assumed to function for predator defence by mimicking predators' enemies' eyes, deflecting attacks or intimidating predators, but the evolutionary processes underlying these functions have never been addressed. Striped body patterns have been suggested to serve for both social communication and predator defence, but the impact of ecological constraints remains unclear. We conducted the first comparative analysis of colour pattern diversity in butterflyfishes (Family: Chaetodontidae), fishes with conspicuous spots, eyespots and wide variation in coloration. Using a dated molecular phylogeny of 95 species (approx. 75% of the family), we tested whether spots and eyespots have evolved characteristics that are consistent with their proposed defensive function and whether the presence of spots and body stripes is linked with species' body length, dietary complexity, habitat diversity or social behaviour. Contrary to our expectations, spots and eyespots appeared relatively recently in butterflyfish evolution and are highly evolutionarily labile, suggesting that they are unlikely to have played an important part in the evolutionary history of the group. Striped body patterns showed correlated evolution with a number of ecological factors including habitat type, sociality and dietary complexity. Our findings question the prevailing view that eyespots are an evolutionary response to predation pressure, providing a valuable counter example to the role of these markings as revealed in other taxa. PMID:23427170

In vivo evaluation of some biophysical parameters of the facial skin of Indian women. Part I: variability with age and geographical locations.

PubMed

Colomb, L; Flament, F; Wagle, A; Agrawal, D

2018-02-01

India is a large country (a subcontinent) of about 3.3 million km 2 that covers large ranges in latitude and longitude. The last Indian census counted about 1.21 billion of inhabitants of many origins, creating a vast human diversity and skin types, the variability of which having been previously established. The present study aimed at deepening this knowledge through a set of biophysical measurements to describe, along the skin ageing process, the specificities of various Indian subjects living in different geographical locations. A total of 1204 women, aged 18-84 years, of all socio-economic status, were recruited in four Indian cities (Mumbai, Kolkata, Chennai and Delhi). Measurements of face skin colour properties, elastic properties, sebum production, skin pores and microrelief roughness were performed. With regard skin colour, this study indicates, with age, a darkening of very low amplitude that leads to an increased skin colour heterogeneity. In all subjects, at all ages, the ocular region (dark circles) presents a much darker pigmentation than the cheeks, creating a contrast that appears constant at all ages. In addition to an increased skin colour heterogeneity, a progressive alteration of the skin surface relief, increased sizes of skin pores, a loss of skin elasticity and a drop in sebum production, post-menopause, are observed. This study confirms, in Indian women, some skin ageing measurements found on women from other ethnic groups (i.e. sebum, firmness, wrinkles and pores size) and also identifies some Indian specificities: a high and constant contrast between the ocular region and the cheek colour, associated to a very slow darkening effect along the lifespan. © 2017 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Carotenoid supplementation and sex-specific trade-offs between colouration and condition in common tern chicks.

PubMed

Benito, María M; González-Solís, Jacob; Becker, Peter H

2011-05-01

Carotenoids, as pigments with antioxidant and immunoregulatory properties, play a crucial role in developing chicks. Carotenoids must be acquired through diet and are relatively scarce, suggesting that their availability is a limiting factor leading to a trade-off between colour displays and physiological functions. However, potential differences in this trade-off between male and female chicks have been little studied. We manipulated carotenoid availability in 9 days old common tern Sterna hirundo chicks by supplementing their fish diet with four carotenoids during 9 days. Our aim was to examine sex-specific responses to the experimental increase of dietary carotenoids on plasma circulation, physiological and condition variables and successful fledging. Furthermore, to explore the functional and evolutionary basis of the trade-off, we studied the relationships among carotenoid concentration, mediated immune response and foot colouration. After treatment, control chicks showed decreasing plasma levels for most carotenoid types, whereas supplemented chicks had strong increases. Colour luminosity and saturation increased in both treatment groups, while hue only changed significantly towards redder feet in supplemented females. Supplemented chicks presented neither different T-cell-mediated immunity nor other differences compared to control chicks. Nevertheless, supplemented females showed tendencies towards decreased immune responses and increased δ(15)N signatures, and supplemented males towards greater body mass. Our results indicate colouration may have, in females, a signalling function as to compensate for immunological costs. In males, additional availability of carotenoids may contribute to improve the body condition. This study suggests that trade-off responses to carotenoid availability are sex-specific in tern chicks. Thus, parental carotenoid supply to chicks may be an unrecognised component in sex allocation.

Antioxidant Machinery Differs between Melanic and Light Nestlings of Two Polymorphic Raptors

PubMed Central

Galván, Ismael; Gangoso, Laura; Grande, Juan M.; Negro, Juan J.; Rodríguez, Airam; Figuerola, Jordi; Alonso-Alvarez, Carlos

2010-01-01

Colour polymorphism results from the expression of multiallelic genes generating phenotypes with very distinctive colourations. Most colour polymorphisms are due to differences in the type or amount of melanins present in each morph, which also differ in several behavioural, morphometric and physiological attributes. Melanin-based colour morphs could also differ in the levels of glutathione (GSH), a key intracellular antioxidant, because of the role of this molecule in melanogenesis. As GSH inhibits the synthesis of eumelanin (i.e. the darkest melanin form), individuals of darker morphs are expected to have lower GSH levels than those of lighter morphs. We tested this prediction in nestlings of two polymorphic raptors, the booted eagle Hieraaetus pennatus and the Eleonora's falcon Falco eleonorae, both of which occur in two morphs differing in the extent of eumelanic plumage. As expected, melanic booted eagle nestlings had lower blood GSH levels than light morph eagle nestlings. In the Eleonora's falcon, however, melanic nestlings only had lower GSH levels after controlling for the levels of other antioxidants. We also found that melanic female eagle nestlings had higher levels of antioxidants other than GSH and were in better body condition than light female eagle nestlings. These findings suggest an adaptive response of melanic nestlings to compensate for reduced GSH levels. Nevertheless, these associations were not found in falcons, indicating species-specific particularities in antioxidant machinery. Our results are consistent with previous work revealing the importance of GSH on the expression of melanic characters that show continuous variation, and suggest that this pathway also applies to discrete colour morphs. We suggest that the need to maintain low GSH levels for eumelanogenesis in dark morph individuals may represent a physiological constraint that helps regulate the evolution and maintenance of polymorphisms. PMID:20976228

Antioxidant machinery differs between melanic and light nestlings of two polymorphic raptors.

PubMed

Galván, Ismael; Gangoso, Laura; Grande, Juan M; Negro, Juan J; Rodríguez, Airam; Figuerola, Jordi; Alonso-Alvarez, Carlos

2010-10-14

Colour polymorphism results from the expression of multiallelic genes generating phenotypes with very distinctive colourations. Most colour polymorphisms are due to differences in the type or amount of melanins present in each morph, which also differ in several behavioural, morphometric and physiological attributes. Melanin-based colour morphs could also differ in the levels of glutathione (GSH), a key intracellular antioxidant, because of the role of this molecule in melanogenesis. As GSH inhibits the synthesis of eumelanin (i.e. the darkest melanin form), individuals of darker morphs are expected to have lower GSH levels than those of lighter morphs. We tested this prediction in nestlings of two polymorphic raptors, the booted eagle Hieraaetus pennatus and the Eleonora's falcon Falco eleonorae, both of which occur in two morphs differing in the extent of eumelanic plumage. As expected, melanic booted eagle nestlings had lower blood GSH levels than light morph eagle nestlings. In the Eleonora's falcon, however, melanic nestlings only had lower GSH levels after controlling for the levels of other antioxidants. We also found that melanic female eagle nestlings had higher levels of antioxidants other than GSH and were in better body condition than light female eagle nestlings. These findings suggest an adaptive response of melanic nestlings to compensate for reduced GSH levels. Nevertheless, these associations were not found in falcons, indicating species-specific particularities in antioxidant machinery. Our results are consistent with previous work revealing the importance of GSH on the expression of melanic characters that show continuous variation, and suggest that this pathway also applies to discrete colour morphs. We suggest that the need to maintain low GSH levels for eumelanogenesis in dark morph individuals may represent a physiological constraint that helps regulate the evolution and maintenance of polymorphisms.

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.

The Genetic Architecture of Barley Plant Stature

PubMed Central

Alqudah, Ahmad M.; Koppolu, Ravi; Wolde, Gizaw M.; Graner, Andreas; Schnurbusch, Thorsten

2016-01-01

Plant stature in temperate cereals is predominantly controlled by tillering and plant height as complex agronomic traits, representing important determinants of grain yield. This study was designed to reveal the genetic basis of tillering at five developmental stages and plant height at harvest in 218 worldwide spring barley (Hordeum vulgare L.) accessions under greenhouse conditions. The accessions were structured based on row-type classes [two- vs. six-rowed] and photoperiod response [photoperiod-sensitive (Ppd-H1) vs. reduced photoperiod sensitivity (ppd-H1)]. Phenotypic analyses of both factors revealed profound between group effects on tiller development. To further verify the row-type effect on the studied traits, Six-rowed spike 1 (vrs1) mutants and their two-rowed progenitors were examined for tiller number per plant and plant height. Here, wild-type (Vrs1) plants were significantly taller and had more tillers than mutants suggesting a negative pleiotropic effect of this row-type locus on both traits. Our genome-wide association scans further revealed highly significant associations, thereby establishing a link between the genetic control of row-type, heading time, tillering, and plant height. We further show that associations for tillering and plant height are co-localized with chromosomal segments harboring known plant stature-related phytohormone and sugar-related genes. This work demonstrates the feasibility of the GWAS approach for identifying putative candidate genes for improving plant architecture. PMID:27446200

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.

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.

Developmental validation of the HIrisPlex system: DNA-based eye and hair colour prediction for forensic and anthropological usage.

PubMed

Walsh, Susan; Chaitanya, Lakshmi; Clarisse, Lindy; Wirken, Laura; Draus-Barini, Jolanta; Kovatsi, Leda; Maeda, Hitoshi; Ishikawa, Takaki; Sijen, Titia; de Knijff, Peter; Branicki, Wojciech; Liu, Fan; Kayser, Manfred

2014-03-01

Forensic DNA Phenotyping or 'DNA intelligence' tools are expected to aid police investigations and find unknown individuals by providing information on externally visible characteristics of unknown suspects, perpetrators and missing persons from biological samples. This is especially useful in cases where conventional DNA profiling or other means remain non-informative. Recently, we introduced the HIrisPlex system, capable of predicting both eye and hair colour from DNA. In the present developmental validation study, we demonstrate that the HIrisPlex assay performs in full agreement with the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines providing an essential prerequisite for future HIrisPlex applications to forensic casework. The HIrisPlex assay produces complete profiles down to only 63 pg of DNA. Species testing revealed human specificity for a complete HIrisPlex profile, while only non-human primates showed the closest full profile at 20 out of the 24 DNA markers, in all animals tested. Rigorous testing of simulated forensic casework samples such as blood, semen, saliva stains, hairs with roots as well as extremely low quantity touch (trace) DNA samples, produced complete profiles in 88% of cases. Concordance testing performed between five independent forensic laboratories displayed consistent reproducible results on varying types of DNA samples. Due to its design, the assay caters for degraded samples, underlined here by results from artificially degraded DNA and from simulated casework samples of degraded DNA. This aspect was also demonstrated previously on DNA samples from human remains up to several hundreds of years old. With this paper, we also introduce enhanced eye and hair colour prediction models based on enlarged underlying databases of HIrisPlex genotypes and eye/hair colour phenotypes (eye colour: N = 9188 and hair colour: N = 1601). Furthermore, we present an online web-based system for individual eye and hair colour prediction from full and partial HIrisPlex DNA profiles. By demonstrating that the HIrisPlex assay is fully compatible with the SWGDAM guidelines, we provide the first forensically validated DNA test system for parallel eye and hair colour prediction now available to forensic laboratories for immediate casework application, including missing person cases. Given the robustness and sensitivity described here and in previous work, the HIrisPlex system is also suitable for analysing old and ancient DNA in anthropological and evolutionary studies. Copyright © 2013 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

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.

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.

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.

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.

Impact of implementation of spaceborne lidar-retrieved canopy height in the WRF model

NASA Astrophysics Data System (ADS)

Lee, Junhong; Hong, Jinkyu

2017-04-01

Canopy height is closely related to biomass and aerodynamic properties, which regulate turbulent transfer of energy and mass at the soil-vegetation-atmosphere continuum. However, this key information has been prescribed as a constant value in a fixed plant functional type in atmospheric models. This presentation reports impacts of using realistic forest canopy height, retrieved from spaceborne LiDAR, on regional climate simulation in the Weather Research and Forecasting (WRF) model's land surface model. Numerical simulations were conducted over the Amazon Basin and East Asia during summer season. Over these regions, the LiDAR-retrieved canopy heights were higher than the default values used in the WRF,which are dependent only on plant functional type. By modifying roughness length and zero-plane displacement height, the change of canopy height resulted in changes in surface energy balance by regulating aerodynamic conductances and vertical temperature gradient, thus modifying the lifting condensation level and equivalent potential temperature in the atmospheric boundary layer. Our analysis also showed that the WRF model better reproduced the observed precipitation when LiDAR-retrieved canopy height was used over the Amazon Basin.

Determination of Metal Levels in Shamma (Smokeless Tobacco) with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in Najran, Saudi Arabia

PubMed

Brima, Eid Ibrahim

2016-10-01

Objective: The use of Shamma (smokeless tobacco) by certain groups is giving rise to health problems, including cancer, in parts of Saudi Arabia. Our objective was to determine metals levels in Shamma using inductively coupled plasma mass spectrometry (ICP-MS). Methods: Thirty-three samples of Shamma (smokeless tobacco) were collected, comprising four types: brown Shamma (n = 14.0), red Shamma (n = 9.0), white Shamma (n = 4.0), and yellow Shamma (n = 6.0). All samples were collected randomly from Shamma users in the city of Najran. Levels of 11 elements (Al, As, Cd, Co, Cr, Cu, Li, Mn, Ni, Pb, and Zn) were determined by ICP-MS. Results: A mixed standard (20 ppb) of all elements was used for quality control, and average recoveries ranged from 74.7% to 112.2%. The highest average concentrations were found in the following order: Al (598.8–812.2 μg/g), Mn (51.0–80.6 μg/g), and Ni (23.2–53.3 μg/g) in all four Shamma types. The lowest concentrations were for As (0.7–1.0 μg/g) and Cd (0.0–0.06 μg/g). Conclusions: The colour of each Shamma type reflects additives mixed into the tobacco. Cr and Cu were showed significant differences (P < 0.05) among Shamma types. Moreover, Pb levels are higher in red and yellow Shamma, which could be due to use (PbCrO4) as yellow colouring agent and lead tetroxide, Pb3O4 as a red colouring agent. The findings from this study can be used to raise public awareness about the safety and health effects of Shamma, which is clearly a source of oral exposure to metals. Creative Commons Attribution License

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.

Goblet Cells and Mucus Types in the Digestive Intestine and Respiratory Intestine in Bronze Corydoras (Callichthyidae: Teleostei).

PubMed

Leknes, I L

2015-10-01

The structure and histochemical properties of the intestine in bronze corydoras (Corydoras aeneus), a stomach-containing teleost, are described, with emphasis on goblet cells and mucin types. The proximal intestine displayed a normal structure for teleosts, whereas the distal intestine was wide, translucent, thin-walled, richly vascularized and constantly filled with air, suggesting an important respiratory role. Goblet cells were common throughout the entire intestine and displayed a variable, but mainly faint metachromatic colour after toluidine blue. They were moderately coloured by alcian blue at both pH 2.5 and 0.2 and displayed no colour after periodic acid followed by Schiff's solution (PAS), but a distinct purple-brown colour after high iron diamine followed by alcian blue (pH 2.5). Together, these results suggest that the mucin in the intestine goblet cells consists mainly of sulphated proteoglycans. Further, the results from the present lectin and neuraminidase tests suggest that these mucins contain much N-acetylglucoseamines and some N-acetylgalactosamines and sialic acid, but seem to lack glucose and mannose. They also contain some galactose-N-acetylgalactosamines sequences, normally hidden by sialic acid. The distinct brush border and mucus layer on the epithelial cells in the respiratory intestine may indicate some digestive roles, such as absorption of water, ions and simple carbohydrates. As sulphated proteoglycans are tough and attract much water, this mucus may play important roles in the protection against mechanical and chemical damages and in the defence against micro-organisms throughout the entire intestine, but in the respiratory intestine it may impede significantly the oxygen uptake. However, as this part of the intestine usually contains no digesta, but is completely filled with air, frequently renewed by dry air from the atmosphere, and the main function of the mucus may be to protect the respiratory epithelium against a destroying and dangerous desiccation. © 2014 Blackwell Verlag GmbH.

Dichroic Liquid Crystal Displays

NASA Astrophysics Data System (ADS)

Bahadur, Birendra

The following sections are included: * INTRODUCTION * DICHROIC DYES * Chemical Structure * Chemical and Photochemical Stability * THEORETICAL MODELLING * DEFECTS CAUSED BY PROLONGED LIGHT IRRADIATION * CHEMICAL STRUCTURE AND PHOTOSTABILITY * OTHER PARAMETERS AFFECTING PHOTOSTABILITY * CELL PREPARATION * DICHROIC PARAMETERS AND THEIR MEASUREMENTS * Order Parameter and Dichroic Ratio Of Dyes * Absorbance, Order Parameter and Dichroic Ratio Measurements * IMPACT OF DYE STRUCTURE AND LIQUID CRYSTAL HOST ON PHYSICAL PROPERTIES OF A DICHROIC MIXTURE * Order Parameter and Dichroic Ratio * EFFECT OF LENGTH OF DICHROIC DYES ON THE ORDER PARAMETER * EFFECT OF THE BREADTH OF DYE ON THE ORDER PARAMETER * EFFECT OF THE HOST ON THE ORDER PARAMETER * TEMPERATURE VARIATION OF THE ORDER PARAMETER OF DYES IN A LIQUID CRYSTAL HOST * IMPACT OF DYE CONCENTRATION ON THE ORDER PARAMETER * Temperature Range * Viscosity * Dielectric Constant and Anisotropy * Refractive Indices and Birefringence * solubility43,153-156 * Absorption Wavelength and Auxochromic Groups * Molecular Engineering of Dichroic Dyes * OPTICAL, ELECTRO-OPTICAL AND LIFE PARAMETERS * Colour And CIE Colour space120,160-166 * CIE 1931 COLOUR SPACE * CIE 1976 CHROMATICITY DIAGRAM * CIE UNIFORM COLOUR SPACES & COLOUR DIFFERENCE FORMULAE120,160-166 * Electro-Optical Parameters120 * LUMINANCE * CONTRAST AND CONTRAST RATIO * SWITCHING SPEED * Life Parameters and Failure Modes * DICHROIC MIXTURE FORMULATION * Monochrome Mixture * Black Mixture * ACHROMATIC BLACK MIXTURE FOR HEILMEIER DISPLAYS * Effect of Illuminant on Display Colour * Colour of the Field-On State * Effect of Dye Linewidth * Optimum Centroid Wavelengths * Effect of Dye Concentration * Mixture Formulation Using More Than Three Dyes * ACHROMATIC MIXTURE FOR WHITE-TAYLOR TYPE DISPLAYS * HEILMEIER DISPLAYS * Theoretical Modelling * Threshold Characteristic * Effects of Dye Concentration on Electro-optical Parameters * Effect of Cholesteric Doping * Effect of Alignment * Effect of Thickness * Impact of Order Parameter * Impact of the Host * Impact of Polarizer * Colour Applications * Multiplexing * QUARTER WAVE PLATE DICHROIC DISPLAYS * Operational Principle and Display Configuration11-13 * Electro-Optical Performance * DYE-DOPED TN DISPLAYS * Threshold Characteristic, Contrast Ratio and Switching Speed * PHASE CHANGE EFFECT DICHROIC LCDs * Theoretical Background * Threshold Characteristic and Molecular Orientation * MOLECULAR ORIENTATION DURING FIELD-INDUCED PHASE TRANSITION WITH HOMOGENEOUS WALL ALIGNMENT * MOLECULAR ORIENTATION DURING FIELD-INDUCED PHASE TRANSITION WITH HOMEOTROPIC WALL ALIGNMENT * Contrast Ratio, Transmission, Brightness and Switching Speed3,7,10,198-214 * Memory or Reminiscent Contrast * Electro-optical Performance vs. Temperature * Multiplexing Phase Change Dichroic LCDs * DOUBLE CELL DICHROIC LCDs3,9,14-17,232-234 * Double Cell Nematic Dichroic LCD3,8,9,14,15,233 * Double Cell One Pitch Cholesteric LCD16,17 * Double Cell Phase Change Dichroic LCD214,232 * POSITIVE MODE DICHROIC LCDS3,8,9 * Positive Mode Heilmeier Cells3,8,9,43,77,78,235-238 * USING PLEOCHROIC DYES3,8,9,43,235-238 * USING NEGATIVE DICHROIC DYES3,8,9,63,77,78156 * DUAL FREQUENCY ADDRESSED DICHROIC DISPLAYS75,238 * Positive Mode Dichroic LCDs Using λ/4 Plate * Positive Mode Double Cell Dichroic LCD * Positive Mode Dichroic LCDs Using Special Electrode patterns7,8,239-241 * Positive Mode Phase Change Dichroic LCDs3,8,9,230,243-248 * Dichroic LCDs Using an Admixture of Pleochroic and Negative Dichroic Dyes78,118 * SUPERTWIST DICHROIC EFFECT (SDE) DISPLAYS21-23 * FERROELECTRIC DICHROIC LCDs24-27 * Devices Using A Single Polarizer * Devices Using No Polarizer24-27 * POLYMER DISPERSED DICHROIC LCDs28-30,252-259 * DICHROIC POLYMER LIQUID CRYSTAL DISPLAYS * Heilmeier Type Displays * Guest-Host Cell Using an Admixture Of L.C. Polymer and Low Molecular Weight Liquid Crysta As Host * Polymeric Ferroelectric Dichroic LCDs * SMECTIC A DICHROIC LCDs * Laser Addressed Dichroic SA Displays * Thermally and Electrically Addressed Dichroic SA Displays * FLUORESCENT DICHROIC LCDs * ACKNOWLEDGEMENTS * REFERENCES

Search for Type Ia supernova NUV-optical subclasses

NASA Astrophysics Data System (ADS)

Cinabro, David; Scolnic, Daniel; Kessler, Richard; Li, Ashley; Miller, Jake

2017-04-01

In response to a recently reported observation of evidence for two classes of Type Ia supernovae (SNe Ia) distinguished by their brightness in the rest-frame near-ultraviolet (NUV), we search for the phenomenon in publicly available light-curve data. We use the SNANA supernova analysis package to simulate SN Ia light curves in the Sloan Digital Sky Survey (SDSS) Supernova Search and the Supernova Legacy Survey (SNLS) with a model of two distinct ultraviolet classes of SNe Ia and a conventional model with a single broad distribution of SN-Ia ultraviolet brightnesses. We compare simulated distributions of rest-frame colours with these two models to those observed in 158 SNe Ia in the SDSS and SNLS data. The SNLS sample of 99 SNe Ia is in clearly better agreement with a model with one class of SN Ia light curves and shows no evidence for distinct NUV sub-classes. The SDSS sample of 59 SNe Ia with poorer colour resolution does not distinguish between the two models.

Anatomical and Functional Recovery of Intracapsular Fractures of the Mandibular Condyle: Analysis of 124 Cases after Closed Treatment

PubMed Central

Lee, Jong-Sung; Jeon, Eun-Gyu; Seol, Guk-Jin; Choi, So-Young; Kim, Jin-Wook; Kwon, Tae-Geon; Paeng, Jun-Young

2014-01-01

Purpose: The purpose of this study is to evaluate the influence of intracapsular fracture lines of the mandibular condyle on the anatomical and functional recovery after non-surgical closed treatment. Methods: Clinical and radiological follow-up of 124 patients with intracapsular fractures of the mandibular condyle was performed after closed treatment between 2005 and 2012. The intracapsular fractures were classified into three categories: type A (medial condylar pole fracture), type B (lateral condylar pole fracture with loss of vertical height) and type M (multiple fragments or comminuted fracture). Results: By radiological finding, fracture types B and M lost up to 24% vertical height of the mandibular condyle compared to the height on the opposite side. In Type M, moderate to severe dysfunction was observed in 33% of the cases. Bilateral fractures were significantly associated with the risk of temporomandibular joint (TMJ) dysfunction in fracture types A and B. Bilateral fracture and TMJ dysfunction were not statistically significantly associated in type M fractures. Conclusion: Most of the mandibular intracapsular condylar fractures recovered acceptably after conservative non-surgical treatment with functional rehabilitation, even with some anatomical shortening of the condylar height. The poor functional recovery encountered in type M fractures, especially in cases with additional fracture sites and bilateral fractures, points up the limitation of closed treatment in such cases. PMID:27489844

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

Biofortification of rice with the essential amino acid lysine: molecular characterization, nutritional evaluation, and field performance

PubMed Central

Yang, Qing-qing; Zhang, Chang-quan; Chan, Man-ling; Zhao, Dong-sheng; Chen, Jin-zhu; Wang, Qing; Li, Qian-feng; Yu, Heng-xiu; Gu, Ming-hong; Sun, Samuel Sai-ming; Liu, Qiao-quan

2016-01-01

Rice (Oryza sativa L.), a major staple crop worldwide, has limited levels of the essential amino acid lysine. We previously produced engineered rice with increased lysine content by expressing bacterial aspartate kinase and dihydrodipicolinate synthase and inhibiting rice lysine ketoglutarate reductase/saccharopine dehydrogenase activity. However, the grain quality, field performance, and integration patterns of the transgenes in these lysine-enriched lines remain unclear. In the present study, we selected several elite transgenic lines with endosperm-specific or constitutive regulation of the above key enzymes but lacking the selectable marker gene. All target transgenes were integrated into the intragenic region in the rice genome. Two pyramid transgenic lines (High Free Lysine; HFL1 and HFL2) with free lysine levels in seeds up to 25-fold that of wild type were obtained via a combination of the above two transgenic events. We observed a dramatic increase in total free amino acids and a slight increase in total protein content in both pyramid lines. Moreover, the general physicochemical properties were improved in pyramid transgenic rice, but the starch composition was not affected. Field trials indicated that the growth of HFL transgenic rice was normal, except for a slight difference in plant height and grain colour. Taken together, these findings will be useful for the potential commercialization of high-lysine transgenic rice. PMID:27252467

Solvent optimization for anthocyanin extraction from Syzygium cumini L. Skeels using response surface methodology.

PubMed

Chaudhary, Bratati; Mukhopadhyay, Kunal

2013-05-01

Anthocyanins are plant pigments that are potential candidates for use as natural food colourant. In this study, Syzygium cumini fruit skin has been used as anthocyanin source. All the six major types of anthocyanins were identified in the sample by ultra performance liquid chromatography studies, and the antioxidant activity was found to be 4.34 ± 0.26 Fe(2+)g(- 1) in the sample with highest anthocyanin content. Optimization of conditions for extracting high amounts of anthocyanin from the fruit peels was investigated by response surface methodology. The results suggested that highest anthocyanin yield (763.80 mg; 100 ml(- 1)), highest chroma and hue angle in the red colour range could be obtained when 20% ethanol was used in combination with 1% acetic acid. Methanol was replaced with ethanol for the extraction of pigments due to its less toxicity and being safe for human consumption. The optimized solvent can be used to extract anthocyanins from the S. cumini fruits and used as natural colourants in the food industries.